To report a case in which netarsudil ophthalmic solution 0.02% improved refractory corneal edema after laser peripheral iridotomy (LPI) and Descemet's membrane endothelial keratoplasty (DMEK).A 63-year-old female presented with decreased vision due to corneal edema secondary to iatrogenic endothelial cell loss from previous YAG and argon laser peripheral iridotomy. Initial treatment with topical sodium chloride 5% solution was unsuccessful in resolving the edema. As a result, topical netarsudil was initiated off-label. Improvement in corneal thickness and visual acuity was noted, but after a few months, the left eye decompensated with worsening edema. Cataract surgery with DMEK was performed. Surgery was prolonged and intraoperative floppy iris was encountered. Post-operatively, the patient's best-corrected visual acuity (VA) fluctuated between 20/30 to 20/70 with persistent corneal edema. The central corneal thickness (CCT) ranged from 758 to 779 three months after surgery. Topical netarsudil was started again off-label for cornea edema once nightly. Over the next two months, visual acuity and CCT improved to 20/25 and 650, respectively. Stabilization of visual acuity and cornea edema has been maintained for eight months after initiation of topical netarsudil.Netarsudil, a commercially available rho-kinase inhibitor, may be an effective, non-invasive adjunctive therapy for refractory corneal edema. Our case demonstrates improvement in BCVA and CCT using topical netarsudil, which has been maintained without any vision threatening side effects. Food and Drug Administration for the treatment of elevated intraocular pressure in patients with primary open-angle glaucoma. Rho-associated protein kinase (ROCK) inhibitor, such as netarsudil, act by disrupting actin fibers and decreasing smooth muscle contraction and stiffness in the trabecular meshwork, thereby increasing the flow of aqueous humor.,Interest has also arisen regarding ROCK inhibitors and endothelial function. Rho-Kinase inhibitors have been shown to improve corneal endothelial cell function by decreasing apoptosis and increasing cell proliferation in animal models.2A 63-year-old female patient presented for decreased vision in her left eye. Her past ocular history was significant for narrow anatomical angles, status post argon LPI in both eyes at age 54, and subsequent touch up YAG LPI in the left eye at age 58. Initial BCVA was 20/20 OD and 20/60 OS. On exam, there was edema of the superior cornea extending to the visual axis in both eyes (OU) with left eye (OS) A greaterOur initial differential diagnosis included corneal edema from possible intermittent angle closure, endotheliitis, and most likely, iatrogenic endothelial cell loss from previous LPIs. Treatment for these modalities was initiated. NaCl 5% solution was started at four times per day dosing. The patient returned two weeks later showing no improvement. Prednisolone acetate 1% was added for a possible inflammatory component. With still no improvement, valacyclovir was started for possible herpetic endotheliitis.Visual acuity and CCT in the right eye remained stable at 20/20 and 607, however, the left eye worsened to 20/80 and 762. Intraocular pressure (IOP) ranged from 11 to 18 in both eyes. A trial of netarsudil 0.02% once nightly was initiated, off-label, in the left eye for worsening edema. Over the next four weeks, BCVA OS improved to 20/30 with a decrease in CCT to 677 OS. IOP ranged from 11 to 16. Over the next two months, the right eye remained stable but the left eye decompensated with worsening corneal edema. Netarsudil was increased to two times a day, but there was no further improvement. CCT increased to 758 with worsening BCVA of 20/80 OS, while the IOP remained stable. Microcystic edema progressed to stromal edema with Descemet's folds in the left eye B.The patient underwent combined cataract extraction (CE) with posterior chamber intraocular lens placement and Descemet's membrane endothelial keratoplasty (DMEK) OS. Surgery was prolonged and intraoperative floppy iris was encountered. Pathology revealed a host Descemet's membrane that was devoid of endothelial cells, likely from chronic narrow angle, and iatrogenic cell loss from the LPI and cataract surgery.Re-bubbling was required at three weeks postoperatively due to a partial detachment of the inferior DMEK graft. Despite a successfully attached Descemet's membrane graft, the patient's visual acuity fluctuated between 20/30 and 20/70, CCT ranged from 758 to 779, and IOP ranged between 13 and 18, for three months after surgery A. Netars3Many ophthalmologists in the US are using netarsudil anecdotally to treat corneal edema; however, there are limited publications on its successful use without vision changing side effects like reticular bullous epithelial edema.,The mechanism of Rock inhibitors is hypothesized to improve existing corneal endothelial cell function while minimizing endothelial loss.In our report, our patient had significant endothelial loss at the time of presentation, likely from YAG and argon LPI. It has been well documented that LPI can cause endothelial damage with increasing significance at one year or greater from the initial procedure.Initial use of Netarsudil likely enhanced the function of the remaining endothelial cells, resulting in decreased edema and improved BCVA. Conversely, once the patient lost a critical number of endothelial cells, the beneficial effects of netarsudil were unlikely enough to prevent decompensation, leading to worsening edema. At the time of cataract extraction and DMEK, the host demonstrated no endothelial cells, supporting the reason why topical netarsudil ceased being effective. Yet, once DMEK was successfully completed, the refractory corneal edema was improved once netarsudil was restarted. Again, alluding to hypothesis of netarsudil increasing existing endothelial function. Since we did not find a significant IOP lowering effect from netarsudil in this case - 11 to 18 prior to any netarsudil, and 11 to 17 while on the medication – lower IOP is unlikely to have contributed to the decreased corneal edema.Similar effects of netarsudil have been seen in other case series. Wisely et al. presented the clinical course of a patient who was started on netarsudil to treat corneal stromal edema. Treatment led to improved BVCA, and CCT, as well as eventual diminishing of corneal stromal edema, despite development of 2+ bullous, epithelial edema.We share this case to demonstrate the efficacy of netarsudil 0.02% ophthalmic solution, a commercially available rho-kinase inhibitor in the USA, in improving corneal edema in a patient with iatrogenic endothelial cell loss from LPI and prolonged DMEK surgery. This is currently an off-label use of netarsudil and we hope cases like this will encourage further reports and clinical trials to help elucidate the clinical niche for which netarsudil is useful in our cornea patients.Patient consent to publish was obtained in writing.10.13039/100001818Research to Prevent Blindness  to the Department of Ophthalmology, NYU Langone Health .An unrestricted grant from All authors attest that they meet the current ICMJE criteria for Authorship.No conflicts of interest to report.


To evaluate the effectiveness of metagenomics next-generation sequencing (mNGS) for the detection of pathogenic microorganisms in periprosthetic joint infection (PJI) using the sonication fluid from removed prosthesis.In this prospective diagnostic cohort study, 44 patients who underwent revision arthroplasty in our hospital from December 2016 to December 2018 were screened. Seven cases were excluded due to incomplete clinical data, insufficient synovial fluid or failure of sequencing. According to the PJI diagnostic criteria recommended by the Musculoskeletal Infection Society (MSIS), the patients were defined as PJI or aseptic failure (AF). Conventional culture, sonication fluid culture and mNGS were performed, in order to assess the value of mNGS using sonication fluid for the diagnosis of PJI, and the mNGS results were analyzed and compared with the conventional and sonication fluid culture.Enterococcus faecalis was identified in the cultures, while Enterobacter cloacae was detected by mNGS. In the AF group, the results of the conventional culture were all negative. Nevertheless, Staphylococcus epidermidis was detected in the sonication fluid culture and mNGS in one case. The diagnostic sensitivity of mNGS for PJI was 100%, which was significantly higher than 70.83% (P = 0.039) of the sonication fluid culture and 62.5% (P = 0.021) of the conventional culture. The diagnostic specificity of mNGS for PJI was 92.31%, which was not significantly different (P > 0.05) from those of the conventional culture (100%) and sonication fluid culture (92.31%).Among the 37 patients, 24 were diagnosed with PJI (64.86%), while 13 were diagnosed with aseptic failure. Among the 24 patients diagnosed with PJI, 15 cases (62.5%), 17 cases (70.8%) and 24 cases (100%) yielded positive results in conventional culture, sonication fluid culture and mNGS, respectively. In addition, mNGS detected the same pathogenic microorganisms in 16 out of the 17 (94.12%) culture-positive  PJI cases. In the only one discrepancy case, We demonstrated that mNGS using sonication fluid can improve the detection rate of pathogenic microorganisms and provide valuable information for the diagnosis of PJI. In addition, mNGS can effectively identify pathogenic microorganisms in culture-negative PJIs cases, especially for the cases who have been treated with antibiotics before sample acquisition or have fastidious microorganisms. Therefore, this method can potentially help to guide the clinical use of antibiotics. Periprosthetic joint infection (PJI) represents a serious complication after arthroplasty . The keyIn recent years, multiple reports have indicated that molecular diagnostics based on polymerase chain reaction (PCR) can improve the diagnostic sensitivity of PJI –9. HowevNext-generation sequencing (NGS), especially the metagenomic next-generation sequencing (mNGS), is an evolving technology widely applied in clinical diagnosis . mNGS coIn recent years, sonication fluid culture from explanted prostheses has been found to improve the microbiological yield through disruption of the bacterial biofilm in PJI , 8. HoweThis cohort study was conducted in the First Affiliated Hospital of Fujian Medical University. The study protocols and all operations were reviewed and approved by the Ethics Committee (Ethics Number:2014[047]). Patients who underwent revision arthroplasty in our hospital from December 2016 to December 2018 were screened. The inclusion criteria were met if the patients underwent revision arthroplasty because of PJI, aseptic loosening, periprosthetic fracture. The exclusion criteria were as follows:  specimenTo collect the synovial fluid, joint aspiration was preoperatively performed in the patients suspected of PJI. In patients with insufficient preoperative joint fluid and patients in AF group, the joint fluid was obtained during surgery. Synovial fluid (0.5 ml) was examined for white blood cell count and neutrophil percentage. The prostheses were removed aseptically in the operation room and transported to the microbiology laboratory in a sterile and hermetic plastic box with 500 ml sterile saline solution. After 30 s of vortex oscillation, the box was placed into the water bath of an sonication cleaning machine . The samples were sonicated at 40 kHz for 1 min, and then centrifuged for 15 min at 4000 r/min. Finally, the supernatant was discarded, and the samples were collected . At least 5 periprosthetic tissue samples were collected in each case during surgery for microbiological culture.All samples were immediately transported to the laboratory within 30 min. Synovial fluid and sonication fluid were tested by Gram staining and acid-fast staining, followed by culturing of the bacteria and fungi on blood agar plates. The remaining synovial fluid and sonication fluid were injected into BACTEC Peds Plus/F culture bottles  and cultured in the BACTEC 9050 Culture System . The periprosthetic tissues were cut up and ground before staining and culturing on the blood agar plate. The cultures were incubated at 37 °C and inspected daily for 5 days (aerobic cultures) and respective 14 days (anaerobic cultures). The species in all samples were identified, and the drug sensitivity was determined using the VITEK2 System . The conventional cultures included synovial fluid and periprosthetic tissue cultures, and the results of sonication fluid culture were analyzed independently. Positive culture was defined as > 20 CFU/plate.Mycobacterium tuberculosis complex (MTCP) is recognized as a pathogen when SMRN ≥1, as its nucleic acids are extremely rare in PJI.The sonication fluid mNGS dectection includes the following steps:  Ceramic 2 or Fisher’s exact test for categorical variables. Sensitivity, specificity, positive predictive rate (PPV), negative predictive rate (NPV) and accuracy of each diagnostic method were calculated. McNemar’s chi-square test (two-side) was used to compare the sensitivity and specificity between the diagnostic tests. The SPSS 21.0 software  was used for statistical analyses.Differences between two groups were evaluated using the χP >0.05).The demographic data, clinical manifestations of the patients are shown in Table Staphylococcus aureus was isolated in the other 2 cases in sonication fluid cultures. Among a total of 10 microorganisms isolated by both culture methods, the predominant causative pathogens were coagulase-negative Staphylococci , Enterococcus faecalis  and Staphylococcus aureus .The pathogenic microorganisms detected by the culture and mNGS are listed in Table Enterococcus faecalis was isolated by the conventional and sonication fluid cultures, the mNGS result indicated that the pathogenic microorganism was Enterobacter cloacae. Pathogenic microorganisms were detected by mNGS in the sonication fluid of 7 culture-negative cases , Staphylococcus aureus  and Enterococcus faecalis . In the AF group, the results of conventional culture were all negative, while Staphylococcus epidermidis was detected by culture and mNGS in the sonication fluid in one case . The average proportion of the human nucleic acid was 96.11% , and the average number of standardized stringently mapped reads number of genus (SDTMR) was 10215  in each case. The mNGS results of the 24 PJI cases were all positive when the threshold of RAG was set at 30%. The mNGS results were consistent at the genus and species levels with the results from 16 out of the 17 culture-positive cases . Nevertheless, only 1 case showed discordant result. While P < 0.05). The sonication fluid mNGS exhibited a sensitivity of 100% and a specificity of 92.31%. The sensitivity of sonication fluid mNGS was significantly higher than those of the conventional and sonication fluid cultures (P < 0.05), while the specificity of sonication fluid mNGS (92.31%) was lower than that of the conventional culture, but the difference was not statistically significant (P > 0.05).The performance of diagnostic tests is summarized in Table 6/L with 81.9% being neutrophils. The results of the conventional microbial culture were all negative. However, Staphylococcus aureus was identified in the sonication fluid by culture, the diagnosis of PJI was definitely made according to MSIS criteria. mNGS analysis of the genomic DNA from sonication fluid also yielded 26 reads for Staphylococcus aureus.Case 1, a 90-year-old male had undergone a right total hip arthroplasty (THA) five years ago, and a sinus tract was present at the incision 8 months ago. At admission, his CRP level was 17.1 mg/L and ESR was 17 mm/h. The white blood cell count of synovial fluid was 7,838 × 106/L with 92.3% neutrophils. The mNGS results of Case 2 suggested that the pathogenic microorganism was Parvimonasmicra (23887 reads). Case 3 in PJI group was a 49-year-old male who underwent a right THA due to femoral neck fracture 8 years ago. One year ago, he felt intermittent right hip pain that was exacerbated by movement and CRP was 11.5 mg/L, ESR was 47 mm/h and the analysis of synovial fluid revealed that the white blood cell count was 6380 × 106/L with 63.8% being neutrophils. The mNGS results indicated Mycoplasma hominis infection (3136 reads) while conventional culture and sonication fluid culture showed negative results. Case 4 in PJI group was a 79 year-old female who underwent a right total knee arthroplasty (TKA) due to knee osteoarthritis one year ago. After the surgery, she suffered from mild and intermittent left knee pain that was exacerbated by movement. A sinus tract was present at the incision 2 months ago and the X-ray showed prosthesis looseness in the tibial side, however, her CRP (2.8 mg/L), ESR (16 mm/h), synovial WBC (820 × 106/L) and neutrophil percentage (47.9%) were all normal. Meanwhile, the results of conventional culture and sonication fluid culture were negative and the mNGS detected Candida tropicalis (2240 reads) in the sonication fluid. Case 5 was a 66 years-old female who was diagnosed as having PJI because of the presence of the sinus tract and her CRP was 65 mg/L, ESR was 8.07 mm/h and the analysis of synovial fluid revealed that the white blood cell count was 9,144 × 106/L with 75.9% being neutrophils at this point. This patient had received antibiotic treatment in another hospital before sampling, thus, the results of conventional culture and sonication fluid culture were all negative. However, Staphylococcus epidermidis (3051 reads) were detected in sonication fluid by mNGS. Case 6 was a 63 year-old male who was assigned into PJI group because his CRP (40.2 mg/L), ESR (58 mm/h), synovial WBC (6870 × 106/L) and neutrophil percentage (83.5%) were all markedly elevated. This patient also had received antibiotic treatment in another hospital before sampling, thus, the results of conventional culture and sonication fluid culture were negative. However, Staphylococcus epidermidis (38534 reads) was detected in sonication fluid by mNGS. Case 7 was a 63 year-old male who underwent right THA 10 years ago because of osteonecrosis of the femoral head (NOFH). A sinus was present at the incision 3 years ago and he was treated with debridement surgery and antibiotics several times in another hospital. His CRP (40.2 mg/L), ESR (58 mm/h), synovial WBC (6780 × 106/L) and neutrophil percentage (83.4%) were all markedly elevated when re-admitted. Case 8 was a 63 year-old male with a repeated progressive swelling and pain in the right knee after TKA for 1.5 years and at this point, the patient’s CRP (12.3 mg/L), ESR (65 mm/h), synovial WBC (32925 × 106/L) and neutrophil percentage (90.3%) were all markedly elevated. The results of conventional culture and sonication culture were all negative. mNGS detected Neisseria macacae (101 reads) and Candida parapsilosis (1022 reads) in sonication fluid. Case 9 was a 89 year-old male who underwent bilateral unicompartmental knee arthroplasty (UKA). Five weeks after the surgery, the right knee was still swollen and pus oozed out from the incision. At this point, his CRP was 90 mg/L, ESR was 120 mm/h and the analysis of synovial fluid revealed that the white blood cell count was 26286 × 106/L with 85.6% being neutrophils, however, the results of conventional culture and sonication fluid culture were negative and Mycoplasma hominis (2491 reads) was detected in sonication fluid by mNGS. Case 10 was a 74-year-old male who had undergone a left TKA 2 months before re-admission and a sinus tract was present at the incision. At admission, his CRP level was 5.62 mg/L and ESR was 16 mm/h. The white blood cell count of synovial fluid was 17179 × 106/L with 62.7% being neutrophils. Enterobacter cloacae was identified with 919 reads by mNGS, whereas Enterococcus faecalis was isolated by conventional and sonication fluid culture. Case 11 was a 58-year-old female who had undergone a right TKA 7 years ago, and was diagnosed with aseptic failure according to the MSIS criteria. When admitted, her CRP level was 8.43 mg/L and ESR was 27 mm/h. The white blood cell count of synovial fluid was 186 × 106/L with 26.8% neutrophils. Although the results of conventional culture were negative, the results of sonication fluid culture and mNGS showed the presence of Staphylococcus epidermidis.Although the conventional culture and sonication fluid culture results were all negative in Cases 2–9, the 8 cases were all diagnosed as having PJI according to the MSIS criteria. Case 2 was a 65 year-old female who underwent a left THA due to developmental dysplasia of left hip. Three years ago, she found a gradually enlarging mass in her left thigh and the MRI showed effusion around the femur and a heterogeneous mass connected to the femur defect via an underlying tract and the analysis of synovial fluid revealed that the white blood cell count was 42,478 × 10Leptospira from the cerebrospinal fluid of a patient with long-term unexplained fever, indicating that mNGS is being gradually implemented in the field of clinical microbial diagnosis [mNGS can sequence all nucleic acid fragments in a clinical sample, enabling the use of bioinformatic methods to obtain microbial sequences and species information. Compared with the PCR-based diagnostic technologies, mNGS has many advantages, such as the capability of simultaneously identifying bacteria and fungi in a single assay and obtaining quantified abundances of microorganisms for distinguishing causative pathogens . As earliagnosis . Moreoveiagnosis .P < 0.05), and the specificity of sonication fluid mNGS (92.31%) was lower than that of the conventional culture, although the difference was not statistically significant (P > 0.05). The mNGS results were consistent with the those of the culture-based methods at both genus and species levels in 16 out of the 17 (94.12%) culture-positive cases. Meanwhile, mNGS could detect pathogenic microorganisms in the sonication fluid of all 7 culture-negative PJI cases, and two of them were caused by multiple microorganisms. The detection rate of pathogenic microorganisms in the PJI group of this study was higher than that reported by Ivy et al., who analyzed the synovial fluid of PJI cases with mNGS [Sonication can effectively destroy the biofilm formed by bacteria on the surface of prosthesis, and can thus increase the amount of bacteria in the samples. Trampuz et al. first reported the use of sonication to treat 120 joint prosthesis, and found that the detection rate of bacteria was improved . HoweverStaphylococcus aureus was isolated in the sonication fluid and the mNGS result was consistent with that of sonication fluid culture. This phenomenon may be due to the fact that the biofilm was disrupted by sonication, more microorganisms were released into the sample, and Staphylococcus aureus is a kind of common pathogenic microorganisms that can be isolated by culture in the clinical laboratory. Therefore, the results of sonication fluid culture and mNGS were consistent. The mNGS results of Case 2 suggested that the pathogenic microorganism was Parvimonasmicra, which belongs to Gram-positive obligate anaerobic cocci and requires highly stringent culture conditions. Accordingly, its detection rate of culture is low. Thus, we have to develop an antibiotic regimen according to the result of mNGS. The patient underwent a 10-week antibiotic treatment . Finally, the infection was effectively controlled [Mycoplasma hominis infection. Mycoplasma hominis is a rare pathogenic microorganism and is difficult to culture without highly specific conditions [Candida tropicalis in the sonication fluid. These 3 cases suggested that mNGS is able toto detect some fastidious microorganisms in sonication fluid. Case 5 were diagnosed as having PJI because of the presence of the sinus tract and Case 6 were assigned into PJI group according to MSIS minor criteria. Both patients also had received antibiotic treatment in another hospital before sampling, thus, the results of conventional culture and sonication fluid culture were all negative. However, Staphylococcus epidermidis were detected in sonication fluid of both patients by mNGS. In Case 7, the results of conventional culture and sonication fluid culture were negative, however, Staphylococcus epidermidis and Enterococcus faecalis were detected in sonication fluid by mNGS. These 3 cases suggested that the mNGS results of sonication fluid are minimally affected by antibiotic treatment. Case 8 was diagnosed as PJI according to the MSIS minor criteria. The results of conventional culture and sonication culture were all negative. mNGS detected Neisseria macacae and Candida parapsilosis in sonication fluid. In Case 9, the results of conventional culture and sonication fluid culture were negative and Mycoplasma hominis was detected in sonication fluid by mNGS. In the above 2 cases, we tested different culture media, sonicated the removed prosthesis, and used prolonged culture time (> 14 days), but still could not detect the pathogenic microorganisms by culture. The negative-culture results may be attributed to the use of antibiotics and characteristics of the fastidious microorganisms. These 3 cases suggested that mNGS can detect some fastidious microorganisms in sonication fluid under the premise, even the patients had received antibiotics before sampling. The results of Case 2–9 indicated that the combination of sonication and mNGS can effectively decrease the false-negative results due to some rare and fastidious pathogenic microorganisms and the use of antibiotics. Meanwhile, mNGS of the sonication fluid can identify the pathogenic microorganisms and guide clinical medication within 72 h. Finally, all 7 patients were treated by surgery and antibiotics according to the mNGS results, no signs of recurrent infection were found during the postoperative follow-up. In Case 10, culture-based result  was discordant with that of mNGS (Enterobacter cloacae). The authors propose that the infection was possibly caused by multiple microorganisms , which may be due to the poor incision healing. The control of infection was ineffective when it was treated by Vancomycin alone. We improved the antibiotic regimen by adding Meropenem. Thereafter, the incision of the patient successfully healed, and the infection was controlled. The failed detection of Enterococcus faecalis by mNGS can be explained that the number of reads belonging to Enterococcus faecalis or the degree of genome coverage was insufficient to allow BLAST alignment with the reference genomes in the database. The results of sonication fluid culture and mNGS were indicative of Staphylococcus epidermidis infection in Case 11 in the AF group. Meanwhile, the results of conventional culture were negative. One explanation is that Staphylococcus epidermidis is a common bacterial species, and may become the contaminating bacteria introduced during the sonication process. Another explanation, the widely applied MSIS criteria were used as the “golden standard” in this study, which included the conventional culture results as the major criteria. This case was defined as AF by negative conventional culture results, and if it was a false negative, it might be a categorization errors. Therefore, in this case, it has yet to be determined based on subsequent clinical symptoms whether hidden infection is present. At present, the patients were only followed up for 3 months, and the CRP and ESR are temporarily at normal levels. However, the possibility of infection is not yet excluded, and further follow-up is needed.In our study, Case 1 underwent right THA and a sinus was present at the incision 8 months ago. Conventional culture showed negative results, while ntrolled . In Casenditions . ConsequThis study has the following limitations:  There weWe demonstrated that mNGS of the sonication fluid can improve the detection rate of pathogenic microorganisms and provide valuable information for the diagnosis of PJI, and the mNGS results were highly consistent with the those of culture. In addition, mNGS can effectively identify pathogenic microorganisms in culture-negative PJIs cases, especially in the cases treated with antibiotics before surgery or those having rare or fastidious microorganisms. Therefore, this method can potentially help to guide the clinical use of antibiotics.


TP53 mutation, was analyzed. Non-neoplastic colonic mucosa showed cytoplasmic SPATA18 expression. Seventy-two percent of the lesions (193/268) displayed high SPATA18 expression in the cytoplasm of CRC cells. Univariate analyses revealed significant associations between SPATA18 expression and tumor size (p < 0.0001), histological differentiation (p = 0.0017), and lymph node metastasis (p = 0.00039). The log-rank test revealed that patients with SPATA18-high CRCs had significantly better survival than SPATA18-low patients (p < 0.0001). Multivariate Cox hazards regression analysis identified tubular-forming histology (hazard ratio [HR] = 0.25), age < 70 years (HR = 0.50), and SPATA18-high (HR = 0.55) as potential favorable factors. Lymph node metastasis (HR = 1.98) and peritoneal metastasis (HR = 5.45) were cited as potential independent risk factors. Cellular proliferation activity was significantly higher in SPATA18-high tumors. However, no significant correlation was detected between SPATA18 expression and p53 immunoreactivity or KRAS/BRAF mutation status. On the basis of our observations, SPATA18 immunohistochemistry can be used in the prognostication of CRC patients.Dysregulation of mitochondrial quality control has been reported to be associated with cancer and degenerative diseases. SPATA18  encodes a p53-inducible protein that can induce lysosome-like organelles within mitochondria that eliminate oxidized mitochondrial proteins and has tumor suppressor functions in mitochondrial quality control. In the present study, 268 primary colorectal cancers (CRCs) were evaluated immunohistochemically for SPATA18 expression to assess its predictive utility and its association with cellular proliferation activity. Furthermore, the association with p53 immunoreactivity, a surrogate marker for  Multiple biomarkers have been identified to assist in disease diagnosis and to predict treatment efficacy and patient outcomes for cancers such as colorectal cancer (CRC) . RecentlMitochondria are maternally inherited, cytoplasmic organelles originating from symbiotic bacteria and are indispensable for bioenergy, biosynthesis, and signaling for stress-sensing for adaptations to the environment ,8. MitocTP53 is one of the most mutated genes in human cancers, numerous studies including gene mutation analyses have been performed to clarify the function of p53. The essential functions of p53 are considered to be as follows: (1) p53 is a transcription factor that activates its target genes by binding to specific sequences [TP53 result in different isoforms with variable transcriptional activity, which leads to different cancer phenotypes [The tumor suppressor p53 was first identified in 1979 as an oncoprotein ,12,13. Oequences ; and (2)equences . Howeverequences ,17. (3) equences , and mutTP53 mutational status frequently used in tumor diagnostics [TP53 missense mutations result in nuclear accumulation of p53 protein, which can be detected as overexpression in the form of diffuse strong nuclear positivity involving at least 80% of the tumor cells but usually almost 100% [TP53 mutation.p53 immunohistochemistry is now considered as an accurate surrogate marker reflecting the underlying gnostics . It has ost 100% . To dateost 100%  and compost 100% , have beThe present study examined the expression status of SPATA18 in CRCs. The associations of SPATA18 expression with clinicopathological features and clinical outcomes were analyzed to assess their potential for clinical use. In addition, the associations between SPATA18 and cellular proliferation markers or p53 immunoreactivity were analyzed to characterize SPATA18-expressing CRCs.Representative images of CRC cases with or without SPATA18 expression are presented in p < 0.0001), histological differentiation (p = 0.0017), and lymph node metastasis (p = 0.00039).The clinical, pathological, and immunohistochemical features of the analyzed tumors are summarized in p < 0.0001; SPATA18-low tumors (p < 0.0001), younger age , and high tumor SPATA18 expression , as potential favorable factors. The analysis also revealed the presence of lymph node metastasis , and peritoneal metastasis  as potential independent risk factors for patients with CRC  was 0.595 -positive cells -regulated balance of fission and fusion dictates their morphology. Altered mitochondrial dynamics are a critical feature of  of Drp1 ,26. AddiThe prognostic impacts of cellular proliferation markers have been controversial in CRC patients ,30,31,32SPATA18 promoters was observed in only 5 out of 57 patients (9%) [TP53 mutations in nearly 50% of CRCs, we hypothesized that dysregulated p53 transcriptional activity leads to abnormal expression of SPATA18. To assess this, we analyzed the association between SPATA18 expression and p53 immunoreactivity, an established surrogate marker for TP53 mutation; however, no significant correlation was found. This may be because mutations in TP53 result in different isoforms with variable transcriptional activity, which leads to different cancer phenotypes [SPATA18 has been reported as a p53-inducible protein; however, its expression has been demonstrated to be regulated in part by gene promoter methylation . In primnts (9%) . Furtherenotypes .Serum carcinoembryonic antigen (CEA) is one of the established biomarkers for diagnosis, monitoring the recurrence and metastasis and the evaluation of chemotherapy in CRC ,36. ReceKRAS/BRAF mutation status. According to our observations, SPATA18 immunohistochemistry can be used in the prognostication of CRC patients. ROS inhibitors or anti-oxidants may be applied to cases with lower SPATA18 tumors or oncogenic KRAS-positive CRCs.The present study immunohistochemically evaluated the expression of SPATA18 in CRCs. SPATA18-high status was identified as a potential favorable factor for CRC patients. SPATA18-high tumors contained a significantly higher number of PHH3-positive cells. However, no significant correlation was detected between SPATA18 expression and p53 immunoreactivity or The Institutional Ethical Review Board of Aichi Medical University Hospital approved this project without the need for patient consent by giving them the opportunity to opt out. Two hundred and sixty-nine formalin-fixed, paraffin-embedded (FFPE) samples of primary colorectal tumors resected at Aichi Medical University Hospital from 2009 to 2012 were collected depending on the availability of tissue samples and clinical information. After surgery, patients were followed for up to 90 months. All tumors were diagnosed as invasive and naïve to chemotherapy or radiotherapy according to TNM classification . Tumors The antibodies used in the present study are summarized in The data for cellular proliferation markers were cited from our previous study . In briep53 immunoreactivity was classified as follows: wild-type, overexpression, complete loss, and cytoplasmic expression . In the Statistical analyses were performed using EZR software version 1.41 . The cutp < 0.05 was used to select variables in the final model.For survival analyses, Kaplan–Meier survival estimates were calculated with the log-rank test. Cox proportional hazards regression analysis was performed to analyze the associations of survival with other factors. The initial model included the following variables: sex , age (<70 years old vs. ≥70 years old), tumor size (<5 cm vs. ≥5 cm), primary tumor location (right-sided colon vs left-sided colon vs rectum), pT stage (pT2 vs. pT3 vs. pT4), tumor histology (moderate to well-differentiated vs. poorly differentiated), mucus production (positive vs. negative), lymph node metastasis (positive vs. negative), peritoneal metastasis (positive vs. negative), distant organ metastasis (positive vs negative), surgical status (complete vs. incomplete resection), mismatch repair system status (preserved vs. deficient), and immunohistochemical data (SPATA18-high vs. SPATA18-low). A backward elimination with a threshold of https://xena.ucsc.edu/ (accessed on 31 January 2022)). The best cut-off values were automatically set by the program for each tumor type.Data from TCGA were analyzed using the UCSC Xena program ). The best cut-off values were automatically set by the program for each tumor type.Survival analyses were performed using Kaplan-Meier Plotter pan-cancer RNA-seq data according to SPATA18 expression -direct sequencing using the following primers: BRAF forward, tgc ttg ctc tga tag gaa aat g; BRAF reverse, cag ggc caa aaa ttt aat cag t.


Collective dynamics of confined colloids are crucial in diverse scenarios such as self-assembly and phase behavior in materials science, microrobot swarms for drug delivery and microfluidic control. Yet, fine-tuning the dynamics of colloids in microscale confined spaces is still a formidable task due to the complexity of the dynamics of colloidal suspension and to the lack of methodology to probe colloids in confinement. Here, we show that the collective dynamics of confined magnetic colloids can be finely tuned by external magnetic fields. In particular, the mechanical properties of the confined colloidal suspension can be probed in real time and this strategy can be also used to tune microscale fluid transport. Our experimental and theoretical investigations reveal that the collective configuration characterized by the colloidal entropy is controlled by the colloidal concentration, confining ratio and external field strength and direction. Indeed, our results show that mechanical properties of the colloidal suspension as well as the transport of the solvent in microfluidic devices can be controlled upon tuning the entropy of the colloidal suspension. Our approach opens new avenues for the design and application of drug delivery, microfluidic logic, dynamic fluid control, chemical reaction and beyond. Collective dynamics of confined magnetic colloids are finely regulated by external magnetic fields, where mechanical properties of colloidal suspension can be probed in real-time, exhibiting tunable microscale fluid transport behavior. Colloidal suspensions of microscopic particles show complex and interesting collective behaviors. In particular, the collective dynamics of colloids is fundamental and ubiquitous for materials assembly ,2, robotHere, we create a system of confined colloids where their collective dynamics can be finely tuned by the magnetic field. We also establish a strategy to characterize the mechanical property of the assembled structure through the pressure-driven intrusion fluid-colloid interaction, while the fluid transport behavior can be dynamically programmed. The collective configuration of the confined colloids is statistically and thermodynamically characterized by the colloidal entropy. Meanwhile, the interplay between the confined colloids and the interplay between the colloidal suspension and geometrical constraints are simultaneously indicated by the pressure value. Both the entropy of magnetic colloids and the fluid transport are prominently affected by the geometrical constraints, packing fraction, and strength and direction of the magnetic field. Moreover, as a proof of concept, this system has been demonstrated for the application of dynamic and preprogrammed fluid transport, remote drug release, microfluidic logic, and chemical reaction, enabling sustained antifouling behavior. We anticipate that this work will enlighten the fundamental research of colloidal science, and applications ranging from fluid transport, multiphase separation and logic microfluidics, to programmable cargo transport. The findings described here would also deepen the understanding of phenomena such as the cellular collective, pollutant treatment by granular particles and stop-and-go in traffic jamming.δ↑, S↑, where δ (= 2/d2D) represents the confining ratio based on the confinement area and the colloid area). To quantify the interaction between the confinement and the colloids, we established a pressure-driven strategy to probe the mechanical property of the confined colloids by intruding an immiscible fluid into the CMCS and measuring the threshold of the pressure difference between the inlet and outlet of the CMCS. We find that there is a proper range to confine the colloids, i.e. δ = 25–625, in which the collective dynamics of confined colloids can be finely modulated and the viscosity of the colloidal suspension can be dramatically changed. In this range of confining ratio, the threshold for the intrusion fluid to permeate CMCS decreases with increasing the confinement size . For a particular size of confinement, the colloidal entropy increases with the volume fraction up to a critical value (S↑), beyond which the colloidal entropy decreases with further increasing volume fraction (S↓). At the critical volume fraction, the entropy of magnetic colloids could be maneuvered in a predetermined manner. If the confined space is fully occupied with the magnetic colloids, the colloidal entropy can hardly be varied upon the external magnetic field  and without (P0) the magnetic field is determined as ΔP/P0, i.e. (P′ – P0)/P0, which increases with the weight percent of the colloids to a critical value around 70 wt.% and then decreases upon further increase of the weight percentage . It also increases with the saturation level of infused colloidal suspension . The pressure change is further explored as a function of the fluid flow rate, which increases as the flow rate is raised .The confined magnetic colloid system (CMCS) is formed by impregnating the magnetic suspensions ) in a three-dimensional (3D) foam network . MRF is a Bingham fluid, containing the microscale magnetic colloids suspended in a non-magnetic fluid and stabilized by a surfactant to avoid settlement . The colSr. When the immiscible fluid is transported through the confined colloids, a distinct pressure threshold is required to conquer the capillary force [Pr. In state i, under a magnetic field that is parallel to the transport flow, the confined colloids could form chain structures along the magnetic direction, during which the entropy of the colloids is reduced (Si < Sr). The pressure threshold increases when the transport fluid permeates this system (Pi) due to the increment of suspension viscosity. As the magnetic strength is enhanced under the same direction, the entropy is further lowered and meanwhile, the critical pressure is further increased . Upon the applying of the magnetic field, the colloids aggregate to form a chain structure with minimization of Helmholtz free energy, which is comprised of magnetic energy, surface energy and energy contributed by entropy (Supplementary equation 3). The threshold pressure change of fluid transport through confined colloids and the entropy change of colloids, which are both linear with the square of magnetic strength , are in positive linear correlation . Once the magnetic field is off, the confined colloids reconfigure back to a random state due to the thermal energy, therefore the fluid transport behavior is also reconfigurable. Moreover, the pressure change can be dynamically tuned via the magnetic directions  from the lattice model (SH < Sr). Based on our simulation, the increment of magnetic field strength increases the entropy change and the length of the chain  and the hindrance of fluid transport (PH > Pr). Moreover, the threshold pressure of transport fluid quantitatively demonstrating the force of the colloids’ interaction could be alternately modulated by changing the states of the magnetic field  pore and tuned the collective behavior of the colloids by a permanent magnet Fig. a. The maiseconds . The entain Fig. b. We theFV and the magnetic force FM on the magnetic particle under the magnetic field. The viscosity of the MRF increases due to the increment of magnetic strength, following a theoretical model  . The MasP increase with intensifying the magnetic field . The chain formation upon the magnetic field leads to the viscosity rising of MRF, which in turn defers the fluid transport and raises the pressure threshold. To further examine the magnetic influence on fluid transport behavior, both gas and liquid were transported through the CMCS at different magnetic strengths. The pressure thresholds of gas and liquid both increase with the magnetic field strength . This analytical model is in accordance with the experimental results . The saturation time (i.e. accumulated time till permeation) and threshold pressure change gth Fig. e. We conentclass1pt{minimaentclass1pt{minimaAdditionally, the orientation of confined magnetic colloids could be efficiently maneuvered in a predetermined manner by varying the magnetic direction, and therefore the fluid transport behavior could also be modulated with the anisotropy of the colloids. Figure FStokes). In state iv, the shear flow completely pushes the magnetic colloids to the wall side, forming a stable pathway in an equilibrium state. We further analyze the difference in the invasion ability of shear flow (i.e. fluid transport behavior) in the shear state when the magnetic direction is different  to explain the anisotropy of the magnetoviscous effect. We simplified the whole process of fluid transport with the lattice model . For both cases, the whole process is divided into four stages: (i) random, (ii) ordered, (iii) shear and (iv) pathway. In state i, the magnetic colloids are distributed randomly in the lattice. In state ii, the colloids are rearranged into chain aggregates aligning to the magnetic direction. In state iii, the MRF is invaded by a shear flow and chain-like aggregates move close to the wall side by Stokes drag force , the colloidal suspension moves along with the intrusion fluid . Under a magnetic field perpendicular to the intrusion fluid, magnetic colloidal chains could close the flow under the same applied pressure PApplied, 0 . As the applied pressure increases , magnetic colloidal chains are sheared by the flow . With further increasing the applied pressure , magnetic colloidal chains are detached and rotated with the flow . When removing the magnetic field, the colloidal chains start to disappear . Without the magnetic field, the intrusion fluid keeps flowing and forming a pathway .In order to visualize the dynamics of the confined colloids when they encounter an intrusion fluid, we designed a transparent device containing a channel in a porous PTFE (Polytetrafluoroethylene) membrane mimicking the torturous pathway as in the copper foam. The magnetorheological fluid was impregnated into the channel, filling the channel and wetting the side of the channel, and airflow was pumped through the confined colloids as the intrusion fluid. Without the magnetic field and under a given applied pressure , and the entropy of shear state is somewhere between the values of the ordered and pathway states  and the colloidal suspension, the interfacial energy, and the antifouling behavior. It is proven that the magnetic suspension can adhere well to the confined network due to the optimum work of adhesion between the suspension and solid matrix . From the viewpoint of interfacial energy, it is also proven that the functional colloidal suspension is fairly stable during fluid transport both theoretically and experimentally . Additionally, the confined magnetic colloid system enables a sustainable antifouling property. For instance, the MRF-infused Cu foam could eliminate the contamination of the Rhodamine B (RB) solution, whereas the bare Cu foam is almost fully polluted by the RB solution.Finally, we illustrate the application of CMCS by demonstrating the drug release control, logic control, dynamic fluid control and chemical reaction control. When the magnetic field is on, the confined magnetic colloids work as a physical barrier that impedes the permeance of the drug. Once the field is off, the confined colloids redistribute in disorder with a lowered apparent viscosity, providing an open pathway for the strong flux of drugs Fig. b. WithouFurthermore, dynamic fluid control can be realized by merely tuning the magnetic strength (i.e. the distance between the magnet and the device) while keeping the fluid flow Fig. c. The flTo sum up, we have established a system to program the collective dynamics of confined magnetic colloids, and probed the mechanical property of the colloids via intrusion fluid-colloid interaction, demonstrating tunable fluid transport behavior. Through the remote magnetic control of confined magnetic colloids, the entropy of the colloids could be modulated, and meanwhile, the pressure threshold of the transport fluid is simultaneously tuned. The entropy change of the confined magnetic colloids is closely related to the confinement, packing fraction of the colloids, magnetic strength and magnetic direction. Our models explore the synergy of thermodynamics and statistical mechanics to understand and control the collective dynamics of confined magnetic colloids. Through the intrusion liquid-colloid interaction, the colloidal interaction strength in confined space is interpreted as the pressure threshold, providing a direct strategy for characterizing the colloids’ mechanical property quantitatively. Therefore, this strategy allows us to not only qualitatively control the entropy of the confined magnetic colloids, but also quantitatively determine the mechanical property of the collective structure. Beyond the magnetic field, the reported strategy of entropy regulation of confined colloids is also applicable to other remote external stimuli, such as acoustic field, light field, electric field and so on. It is envisioned that the concept of reconfigurable magnetic colloids would find uses in smart gating valves in microfluidics, on-demand drug release, dynamic fluid transport, multiphase separation and cargo transport, and the technologies developed here would benefit areas such as swarm intelligence, the cellular collective behavior in biology, pollutant treatment via colloidal particles, and biomedical applications.3. The magnetic spherical particles were carbonyl iron particles with a particle size of 2.3 ± 0.2 μm. The CMCS was established by impregnating the colloidal suspension in a copper foam. The copper foam is a cellular solid with a porous interconnected network. The copper foams were purchased from Soochow Jiashide Co., Ltd. Copper foams with an average pore size of 10 μm, 20 μm and 50 μm were used. The magnetorheological suspension was infused in the copper foam with a volume of 300 μL, 400 μL and 600 μL (400 μL was used unless otherwise stated). The magnetorheological suspension with weight percentages of 10%, 25%, 37.5%, 50%, 75%, 80% and 100% was prepared. The suspension with the weight percent of 75% was used throughout the paper unless otherwise stated. The copper foams with an average pore size of 20 μm were used for confining MF-112 suspension unless otherwise stated.Magnetorheological suspensions (MF-112) were purchased from Henan Huya Trading Co., Ltd. The density of MF-112 is 2.5 g/cmThe aforementioned CMCS was sealed with two polymethyl methacrylate (PMMA) sheets. An inlet tube and an outlet tube were set on the two sides of the PMMA sheet. The fluid transport behavior of the confined colloidal suspensions was determined by measuring the pressure threshold during the flow of gas and liquid. Air was used as the transport gas and deionized water (resistivity 18.2 MΩ · cm) was used as the transport liquid. The pressure difference between the inlet and outlet of the CMCS was measured by wet/wet current output differential pressure transmitters (PX154–025DI and PX273–020DI) from OMEGA Engineering Inc . A Harvard Apparatus PHD ULTRATM Syringe Pump was used for the flow of gas/liquid. Without specification, a flow rate of 1000 μL/min was selected for the CMCS in a constant flow rate mode.−4 T).The magnetic field was applied to the CMCS parallel to, 45° inclined to, and perpendicular to the transport of fluid. For the dynamic response of the magnetic field, the pressure threshold was recorded without and with a magnetic field periodically for 180 s, respectively. The critical pressures of gas and liquid were measured under the magnetic field strength of 0, 25, 50, 100, 200, 300, 400, 500 and 600 Gs  curve and initial curve were determined by a LakeShore 7404 Vibrating Sample Magnetometer.nwaa301_Supplemental_FilesClick here for additional data file.


A 54-year-old woman with acute pancreatitis 6 months ago presented with abdominal pain and vomiting in the past 2 weeks. A computerized tomography (CT) abdomen showed multiple large fluid collections, largest 9.8 × 11.4 × 8.7 cm in the pancreas tail region (The next morning her hemoglobin dropped by 31 g/L (from 83 to 52 g/L), but there was no evidence of hematemesis. She was transfused with two units of packed red blood cells and a CT with contrast was done to assess for bleeding. CT showed the fluid collection measuring at 12 cm with accumulation of extravasated contrast suggesting hemorrhagic transformation (An arteriogram revealed abnormal distal capsular splenic branches with no active extravasation . The splWhile several studies have reported adverse events relating to lumen apposing metal stent, this case documents the first splenic capsule hemorrhage associated with lumen apposing metal stent for draining pancreatic fluid collections.


What an oversight! Fluids are drugs , so why Chow); (2) An update on body fluid compartments and the physiological concepts that guide fluid therapy ; (3) A discussion of fluid kinetics and its relevance to fluid administration in cats ; (4) Contemporary recommendations for the administration of IV fluid regimens in small and large animals ; (5) The effects of IV fluids on the coagulation system ; (6) A discussion of fluid administration in animals with naturally occurring disorders and diseases  including refractory hypotension  and cardiopulmonary resuscitation (Fletcher and Boller); (7) The consequences of fluid overload (Hansen); (8) A description of dynamic fluid therapy monitoring techniques (Boysen and Gommeren); (9) An introduction to fluids of the future (Edwards and Hoareau); and (10) Alternative methods for fluid delivery . The information and citations contained within this collection serve as a rich resource for the design of future studies investigating the safety and efficacy of intravenous fluid therapy in animals.This issue of Frontiers in Veterinary Science provides: (1) A review of the terms used to define or describe fluid therapy  is responsible for ~60–70% of body weight (BW) and is the primary component of all body fluids . The twoStewart; –104]. SeStewart; . The intStewart; , 107. IfStewart; . TransceStewart; . DetermiStewart; –111. SubStewart; –114.Contemporary evidence suggests that the PV is comprised of circulating and non-circulating (15–25% of PV) components, the latter being located within an endothelial surface or glycocalyx layer (GLX) and the channels between vascular epithelial cells , 116. Th2). Veins are ~30 times more compliant than arteries, contain up to five times more adrenergic receptors than arteries and normally serve as blood reservoirs (Blood volume is distributed between the pulmonary (18–20%) and systemic (78–80%) circulations dependent upon their  oxygen requirements  signaling bone marrow to produce more red blood cells. Activated atrial stretch receptors secrete ANP producing vasodilation and increases in glomerular filtration, salt and water excretion, and vascular permeability, thereby regulating PV and lowering arterial blood pressure (ABP)  is governed by a variety of neural and neuroendocrine high-gain homeostatic feedback mechanisms that include, osmoreceptors, osmotically stimulated thirst receptors, hormones  and membrane water channels , especially those located in the renal tubules –144. There (ABP) , 148. Thre (ABP) .2, CO2), and solutes   , 157. Noalbumin) . All thralbumin) –13; . P Yozova; –162. Cap Yozova; , 164. No Yozova; , 163–165Boyd et al.;  or cost.The GLX constitutes ~2% of the PV and functions as two layers: a less permeable, dense branch-like inner layer composed of heparin sulfate and glycoproteins and a more permeable porous outer later composed of plasma proteins and glycosaminoglycans , 166. Th et al.; , 178], i et al.; , and inc et al.; . Disagre et al.; , 50–53;  et al.; ], risk-bv) across capillary walls is historically attributed to Earnest Starling's observations of fluid absorption from connective tissue spaces (Starling 1896)  is a balance of intravascular capillary (c) intravascular and interstitial (i) hydraulic  and oncotic [π: colloid osmotic pressure (COP)] forces  (c) is a function of the hydrostatic P from the inflow  to the outflow (venous: v) end of the capillary and are dependent upon the pre- and post-capillary resistances (R), assuming blood flow remains constant  is therefore opposed by capillary πc  and Pi is opposed by πi (Pi - πi). The Starling hypothesis asserts that fluid is filtered at the arterial end of the capillary because Pc predominates over all other forces, and that fluid is reabsorbed at the venous end of the capillary because πc (osmotic suction) predominates. Interstitial forces  act as modulators of the rate of fluid flux and therefore the volume of Jv (p) and the macromolecular sieving properties of the microvascular barrier (Staverman's reflection coefficient: σ) [ (p and σ into Starlings hypothesis is the basis for what is proclaimed as the “Starling equation” that is still published in most texts [Jv = Lp [(Pc – Pi) – σ (πc – πi)]], although Starling had little to do with its derivation since the earliest form of the equation did not appear until 1927 (The dynamics of fluid flux (Jng 1896) . He concuations) . Capillaconstant –186. A dc and Jv . Under nc and Jv , 185. Plme of Jv , 185. Laent: σ) . Brmeable) . Larger til 1927 .g): Jv = Lp [(Pc – Pi) – σ (πc – πg)]  . Itredicted , 189–195quation .d), the volume of plasma that is completely cleared of the administered fluid per unit time  and the time it takes for the total amount of administered fluid to be reduced by one-half of its original volume  (c) followed by diffusion into a peripheral compartment (Vt)  is much lower than crystalloids, suggesting delayed departure from Vc and prolongation of their volume expanding effects.Volume kinetics (VK) determines the volume into which an administered fluid is distributed  . Intravent (Vt)   increase Vc and decrease Vd, Cld, and Clr  than by the infused fluid volume; higher infusion rates produce greater degrees of interstitial fluid accumulation, hemodilution, coagulation abnormalities, and organ dysfunction (Rapid fluid administration rates (>40–60 ml/kg/hr) and large fluid volumes (>60–80 ml/kg) produce hemodilution, interstitial fluid accumulation , and serious rebleeding in animals with uncontrolled hemorrhage , 203. Moalverde; –206] dec (crit)] , 208, pr (crit)]  and peri (crit)] –212, dec (crit)] , and dep (crit)] , 214. In (crit)] –219. Sti and Clr , 220. Nofunction , 222.Edwards and Hoareau;  continue to be developed for the treatment of specific naturally occurring diseases with the goals of improving tissue oxygenation and perfusion . Isotonommeren; , 237. Noommeren;  or reducommeren; –240 are ommeren; –243. Futommeren; , 245. Meommeren; ; Cooper ommeren; , 246–254ommeren; , impleme et al.; –260]. ItAll authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Chronically implanted neural probes are powerful tools to decode brain activity however, recording population and spiking activity over long periods remains a major challenge. Here, we designed and fabricated flexible intracortical Michigan-style arrays with a shank cross-section per electrode of 250 μm Up to now, only a few neural probes were able to demonstrate significant clinical impact, namely deep brain stimulation3, pacemakers4, and cochlear implants5. However, these devices are mainly used for stimulation purposes as long-term monitoring of neurons (>1 year) still remains a major challenge. Different failure modes are associated with the degrading quality of neural recordings over time such as biotic mechanisms8 dictated by the interactions between the neural probe and tissue, and abiotic mechanisms10 comprising, for example, electrode related degradations and interconnection failures.A pivotal goal in the field of neuroscience is understanding how information is processed within the brain. The objective is to decode not only the functional connections within the healthy brain, but also the dysfunctional processes that are associated with diseases. To this end, a variety of different neural probes have been developed over more than half a century. Chronically implanted neural probes are powerful tools to monitor as well as to modulate neural activity within the brain. Advancements in neurophysiological techniques and microelectromechanical systems (MEMS) technologies enabled the translation of neural interfaces from fundamental research using rodents and monkeys to clinical human applications11, there are two major types of multi-site, intracortical recording devices. Utah arrays12, consisting of many individual needle contacts with a single recording site at the tip, and Michigan arrays13 that can contain densely packed recording sites along at least one penetrating shank. While Utah arrays are currently the only intracortical devices with medical approval, multi-site and multi-shank Michigan arrays allow simultaneous recording of several neurons along the length of the neural track with a lower probe cross-section per electrode2. Traditional Michigan arrays are produced using silicon (Si), which have been shown to lose recording quality over time due to the mechanical mismatch at the device/tissue interface resulting in an enhanced foreign body reaction14. To improve the chronic stability, compliant probes with stress relief at the device/tissue interface have been explored within different studies including finite element modelling16 and histological studies18. Compliance is defined as deflection upon mechanical deformation and is associated not only with the material flexibility but also with the probe dimensions19. Therefore, two main approaches have been investigated to produce compliant neural devices: low Young’s modulus polymers as substrate materials22 and the minimization of the physical probe dimensions24. Paradoxically, intracortical probes that are compliant enough to minimize the foreign body response are unable to penetrate the tissue without mechanical reinforcement, due to their low buckling force threshold19. Therefore, several insertion strategies have been introduced to implant depth neural probes such as stiff shuttles26 and biodegradable polymer coatings29. However, such insertion systems substantially increase the spatial footprint and therefore tissue displacement during implantation. To reduce the acute trauma and improve the long-term acceptance, insertion systems that enable a precise positioning of flexible probes while preserving the small cross-section of the shanks during the implantation are still required.Aside from single-contact microwires30. To ensure high signal-to-noise ratio (SNR) recordings, the microelectrodes were coated with the conductive polymer poly doped with poly(styrenesulfonate) (PEDOT:PSS) employing a high-throughput procedure31. Following probe fabrication and electrochemical characterization, we developed a tissue-friendly insertion system based on a temporary polyethylene glycol (PEG) coating. To validate the flexible probe in combination with the insertion system, we performed acute in vivo recordings in multiple mouse brain regions: the somatosensory cortex and the olfactory bulb. The device performance was evaluated using these two brain regions, responsible for sensory processing, as the physiological nature of the detected neural activities can be easily correlated to the applied stimulations33. Additionally, we took advantage of the different dorsoventral depths of the two brain regions, ranging from 0.8 to 2 mm33, to demonstrate the versatility of our flexible probes. The recording quality was characterized considering the signal amplitude as well as SNR, and compared to commercially available stiff intracortical Michigan probes. After the in vivo evaluation, we further optimized the microfabrication process and to our knowledge, were able to produce the smallest PaC based Michigan probes reported so far by employing a double-metal-layer process.In pursuit of developing flexible intracortical probes suitable for future chronic implantations, we developed Michigan-style arrays by utilizing the mechanically soft and ISO 10993 approved polymer paryleneC (PaC)We demonstrate the microfabrication of flexible intracortical Michigan-style arrays employing PaC, and the production of microelectrodes with the low impedance coating PEDOT:PSS. Furthermore, a tissue-friendly insertion system based on a temporary PEG coating was developed, enabling the insertion of the bare, flexible shanks without increasing the implantation footprint. After successful insertion into agarose gel brain phantoms, the neural probes were implanted into mouse brains. Here, the devices were able to simultaneously detect local field potentials (LFPs), single-unit activity (SUA), and multi-unit activity (MUA). Furthermore, the flexible arrays demonstrated a similar recording quality as commercially available stiff probes or even outperformed them when considering the yield of SUA. Following the successful in vivo validation, we produced PaC based microelectrode arrays (MEAs) with a higher electrode density by establishing a double-metal-layer process to further increase the spatial resolution and to simultaneously access more cells.14, the biocompatible and low Young’s modulus polymer PaC30 was chosen. Additionally, a transparent, uniform and pinhole-free film can be obtained as PaC is deposited via chemical vapour deposition (CVD), which facilitates the integration into microfabrication methods. Utilizing layer-by-layer MEMS techniques, MEAs consisting of a platinum (Pt) or gold (Au) metal film sandwiched between two PaC layers were fabricated. Considering the aimed implantation strategy (see “34) that are still state-of-the-art devices for basic research. The device design and distribution of the recording sites are shown in Fig. The flexible intracortical probes were Michigan-style arrays, which consisted of four shanks with four microelectrodes per shank. To reduce the mechanical mismatch between the device and tissue observed for traditional Si based intracortical implantsegy see “” section35. This conductive polymer crosslinked with ethylene glycol (EG), 3-glycidoxypropyltrimethoxysilane (GOPS), and dodecylbenzene-sulfonic acid (DBSA) was spin-coated onto the recording sites utilizing a PaC sacrificial layer. This procedure needs additional fabrication steps to establish the electrode coating however, it is a high throughput method resulting in ready-to use probes in contrast to electrochemical deposition of PEDOT:PSS, where probes are coated individually. The resulting blue coating with a thickness of 700–750 nm had a mean impedance of 2.93 ± 0.73 MTo ensure high SNR recordings, a low impedance coating was established employing the soft conductive polymer PEDOT:PSSmentclass2pt{minimsee Fig. . A reprementclass2pt{minim37. Single intracortical shanks of the Michigan-style arrays were assumed as fixed-pinned columns as the shanks are fixed from the top by the connector and the micromanipulator, and pinned from the tip as soon as they contact the tissue. The Euler’s formula is commonly used to compute the critical buckling load however, it only applies for long columns. Therefore, the slenderness ratio 37. According to the Euler’s formula  agarose gel brain phantoms. This concentration is commonly used as the gels demonstrate mechanical properties comparable to mammalians’ brains14, even when mechanically reinforced during insertion. Therefore, a durotomy was additionally performed to facilitate probe insertion. For olfactory bulb recordings, the dura was completely removed to gain access to the whole dorsal surface, maximizing the probability of finding odor-evoked mitral cell activity. In the barrel cortex, slits were made in the dura that served as entry points for the shanks. Exemplary preparations are shown in Supplementary Fig. The flexible intracortical probes and the insertion system were then validated in acute in vivo experiments. To confirm that the devices can be used in various brain regions, we performed neural recordings from the mouse barrel cortex with a dorsoventral depth of 0.8 mm as well as from the olfactory bulb with a dorsoventral depth of 2 mm  and SNRs of the SUA . When implanted into the olfactory bulb, significant differences in the performance were observed for flexible arrays compared to stiff devices. A significantly higher SU yield was achieved with the flexible arrays . In the Supplementary Table mentclass2pt{minimmentclass2pt{minimOne main advantage of flexible intracortical probes compared to stiff devices, besides the lower Young’s modulus, is that smaller footprints can be achieved. Our flexible probes with a shank cross-section of 1000 μm23) and were able to double the number of electrodes per shank without increasing the shank cross-section  noise across microelectrodes with a GSA of 113 μmTo ensure high spatial resolution, the area of the recording sites was restricted to 113 μm26 and biodegradable polymer coatings29. However, such traditional strategies have the major drawback that they significantly increase the implantation footprint  Clevios PH-1000 , 5 % (v/v) EG, 1 % (v/v) GOPS, and 0.1 % (v/v) DBSA  was spin-coated three times, once at 3000 rpm and two times at 500 rpm with a 1 min baking step at 90 °C  in between. With the aid of a few drops of water, the PaC sacrificial layer was peeled off and after hard baking at 140 °C  for 1 h, the probes were soaked overnight in water to remove Micro90 residues. At the end, the probes were dry released from the wafer and soldered via flip-chip bonding to custom-made printed circuit boards (PCBs) using the soldering paste NC-31 . The finale PaC based probe soldered to the PCB is shown in Supplementary Fig. The MEAs were produced employing PaC as substrate and insulation layer, and Pt or Au and PEDOT:PSS as conductive films. The fabrication was started with a 5 μm thick substrate layer deposited via CVD  onto a cleaned 4” Si wafer  mold. The mold, the base layer, and the cover sheet were cut from a 120 μm PDMS slap. As shown in the Supplementary Fig. The brain phantom, an agarose gel, was prepared by mixing 0.06 g agarose powder  with 10 ml 0.1 M PBS. The mixture was microwaved a few times at medium level and swirled slowly in between to avoid over-boiling until it became transparent. Then, the solution was cooled down to form the gel. The flexible probes soldered to the PCB and mechanically reinforced by the PEG coating were clamped to a micromanipulator system .The electrochemical impedance of the PEDOT:PSS films was determined with the potentiostat VSP-300  using the three electrode configuration featuring the microelectrodes of the neural probes as working electrode, a coiled Pt wire as counter electrode, and a Ag/AgCl electrode as reference electrode. The measurements were performed in 0.1 M PBS by applying a 10 mV sine wave. The mean impedance was calculated by averaging 12 probes from two different fabrication runs. Electrodes with an impedance higher than 11 Mhttps://arriveguidelines.org). In preparation for the recordings, a craniotomy was made above the barrel cortex (n = 3 mice) or the olfactory bulb (n = 5 mice). All described electrophysiological experiments were acute and done under anesthesia. For each animal, 1–3 penetrations were made with the flexible probes as well as the stiff devices depending on the recording quality. The detailed protocol of the animal surgeries is provided in the Supplementary Method Electrophysiological recordings were performed on wild-type mice of either sex between 3–12 months of age. Mice were housed under standard conditions in ventilated racks. Experimental protocols were approved by the Landesamt für Natur, Umwelt und Verbraucherschutz NRW (LANUV NRW) , Postfach 101052, 45610 Recklinghausen, Germany and comply with European Union legislation and recommendations by the Federation of European Laboratory Animal Science. This study was carried out in compliance with the ARRIVE guidelines , followed by an inter-stimulus interval of 10 s. This cycle was repeated 50 times.Odorant stimulation Odor delivery was achieved using a computer-controlled olfactometer. The following list of odorants was used: ethyl butyrate, methyl valerate, propyl butyrate, isoamyl acetate, 2-Pentanone, ethyl tiglate, sec-butyl acetate, and 2-Hexanone. All odorants were obtained with a 95–99 % purity from Sigma-Aldrich, Germany and were presented as dilutions from saturated vapor in cleaned and humidified air. Odorant concentration was set between 1–2 % from saturated vapor. Odorant stimulation lasted 10 s and was followed by an inter-stimulus interval of 40 s. This cycle was repeated six times for each odorant.Recordings were performed using either flexible or stiff  neural probes. The probes soldered to PCBs were directly connected to a 16 channel headstage , USA) that was secured to a micromanipulator  with a motorized z-axis. After being amplified and digitized on a preamplifier , USA), detected signals were sent to a digital signal processor . The sampling rate was 24 kHz.Some of the flexible probes were labeled with DiI  for postmortem reconstruction of the penetration tracks. The details are provided in the Supplementary Method 49 and exported to Python 350 for further analysis. SNR was defined as following:pp-values less than 0.0001 ], a 1.5 ms snippet centred on the absolute minimum of the waveform was extracted. Spikes were sorted in MATLAB 2020  using the package UltraMegaSort2000Supplementary Information.


Magnetically controlled capsule robots are predominantly used in the diagnosis and treatment of the human gastrointestinal tract. In this study, based on the permanent magnet method, magnetic driving and fluid measurement systems for in-pipe capsule robots were established. Using computational fluid dynamics (CFD) and particle image velocimetry (PIV), the fluid velocity and vorticity in the pipe of the capsule robot were calculated and measured. The running characteristics of the capsule robot were numerically analyzed in the curved pipe and the peristaltic flow. Furthermore, the range and variance method of orthogonal design was used to analyze the influence of four typical parameters  on the three operating performance indicators of the capsule robot . In this paper, the relative magnitude and significance of the influence of each typical parameter on different performance indicators of the robot are presented. According to the different performance requirements of the robot, the different four parameter combinations are optimized. It is hoped that this work provides a reference for the selection of the appropriate mucus, translational speed, and rotational speed of the robot when it is working in pipes with different diameters. A capsule endoscopy  is also known as a capsule gastrointestinal endoscopy system or medical wireless endoscopy. In this procedure, patients swallow capsules that have a built-in camera and signal transmission device. These capsules move in the digestive tract with the help of gastrointestinal peristalsis or an external driving field. Doctors use an external image recorder and image workstation to gain knowledge about patients’ digestive tracts, and thus make disease diagnoses. Compared with plug-in gastrointestinal endoscopy, the advantages of capsule endoscopy are that it is painless, noninvasive, safe, and convenient. However, during passive capsule endoscopy, the speed of travel through the esophagus and the movement in the stomach cannot be controlled, thus preventing a complete examination of the GI tract. Heavy, expensive, and complex magnetic navigation systems have been developed to control the capsule movement in the stomach. More recently, a smaller magnetic guidance system using a hand-held magnet has been developed . In 2020At present, many drive modes of capsule robots exist. One method is the internal drive mode, which uses batteries or cables ,10; howeWhen a capsule robot is working in a pipe filled with mucus, many parameters affect its operating performance, which can be mainly divided into the following categories. One category relates to the parameters of the robot, such as robotic structural and operating parameters. Ye et al. used a square magnet to drive the magnetic capsule of the outer spiral structure for translational and rotational motion, and experimentally analyzed the translational speed of the robot at different robotic rotational speeds under different distances between the permanent magnets and capsule robots . Guo et In conclusion, regarding the operating performance of in-pipe capsule robots, the existing research mainly focuses on the influences and optimization of the various parameters. Theoretical research includes contact mechanics and the theory of the lubrication between the capsule robot and intestine, whereas numerical research mainly involves the application of the CFD method. Experimental research focuses on the spiral structural parameters and operating parameters of capsule robots, magnetic field parameters, etc. However, the relative degree and significance of the influence of various parameters on the operating performance of capsule robots has not been discussed.Using a capsule robot with a permanent drive, in the current study a self-designed measurement system for the fluid flow field was used to verify the accuracy of the proposed calculation method. Furthermore, four different typical parameters  that affect the operating performance of the capsule robot were taken as influencing factors, and the forward resistance of the robot (reflecting the robot’s passing capacity), fluid turbulent intensity near the robot (reflecting the robot’s operating stability), and maximum fluid pressure on the pipe wall  were taken as the optimization objectives. The orthogonal design method was used to analyze the relative degree and significance of the influence of the four parameters on the operating performance of the capsule robot, and the optimal combinations of parameters under different pipe diameters were calculated. This paper provides a basis for the reasonable selection of operating and mucus parameters of capsule robots in pipes of different sizes.In the permanent magnet drive mode, as shown in x-axial direction. Due to the magnetic force of the external permanent magnet, the capsule robot is driven to make a slightly delayed precessing motion along the x-axis. The translational velocity of the capsule robot along the x-axis is the same as that of the external permanent magnet in magnitude and direction, and the rotational speed of the capsule robot around the x-axis is the same as that of the external permanent magnet, but their rotational direction is opposite. The force of the robot in the x-axial direction includes the x component of the magnetic force, the mucus resistance, and the friction force with the pipe wall. The main purpose of the rotation of the capsule robot is to reduce the friction resistance between the robot and the pipe wall, and improve the forward driving force of the robot. The main parameters that affect the operating performance of the capsule robot are pipe diameter d, robotic translational speed v, robotic rotational speed n, and fluid dynamic viscosity η.The external permanent magnet is driven by a motion platform to make a translating and rotating  motion along the In CFD, namely, computational fluid dynamics, the integral and differential terms in the governing equations of fluid mechanics are approximately represented as discrete algebraic equations, and these equations are solved by computer to obtain the numerical solutions at discrete points in time and space.ρ is fluid density; i, j, and k are unit vectors of x, y, and z axes, respectively; hu  is the component of velocity vector u in x, y, and z axes; p is pressure; xhτ, yhτ, and zhτ are components of molecular viscous stress τ; and hf is body force, if the force is gravity and its direction is negative along the y axis, then xf = 0, yf = −ρg, zf = 0.When the robot is working in a pipe filled with fluid, the fluid is assumed to be incompressible and unaffected by temperature. The fluid also satisfies the following conservation equations :(1)∂ρ∂t+Equations (1) and (2) are the dynamics equations of a viscous fluid. Using the CFD method to calculate the above equations, the fluid field near the robot can be obtained, and the force of the fluid on the robot can also be obtained. The solving process of the CFD method used in this paper includes: system modeling, grid division, boundary conditions and parameter setting, and numerical solution.tI is turbulent intensity, v′ is mean square root of the pulsating velocity, N is number of sampling points in a period of time.When the robot precesses in a pipe filled with fluid, the fluid near the robot not only flows along the axial direction of the pipe, but also moves in the tangential direction, so the fluid flow is turbulent. At this time, the fluid pressure and velocity are changed with time. Turbulent intensity is the most important characteristic quantity to describe the turbulent motion characteristics of fluid, and is the relative index used to measure the turbulence. Turbulent intensity, broadly defined, is the ratio of the mean square root of the pulsating velocity to average velocity. The greater the turbulent intensity of the fluid near the robot, the more disordered the relative motion of the fluid, and the worse the stability of the robot.As shown in Considering the translational and rotational motion of the capsule robot, to refine the grid of the fluid zone around the capsule robot and analyze the influence of the fluid characteristics of this zone on the operation of the robot, a layer of wrapping fluid was added around the robot. As shown in the yellow zone of The fluid in the pipe includes two fluid zones: the wrapping fluid around the robot and the residual fluid in the pipe. Unstructured tetrahedral meshes are used in the two fluid zones, and refined meshes are used in the wrapping fluid zone. Under the condition that the quality of the grid meets the requirements of the calculation, the number of grids is increased, and the time step size is decreased until the numerical results tend to be stable. k-ε model was adopted for the turbulent model, and the standard wall function was used near the pipe wall. According to the actual application, the translational speed v of the capsule robot ranged from 0.02 to 0.06 m/s, the rotational speed n of the capsule robot ranged from 60 to 180 r/min, the variation range of the pipe diameter d was 14~22 mm, and the variation range of fluid viscosity η was 0.005~0.1 Pa·s. The sliding mesh and dynamic mesh technology were used to handle the rotation and translation of the robot, and the robot was assumed to precess along the x-axis.The standard According to the characteristics of intestinal tract, both ends of the pipe were treated with walls, and it was assumed that the fluid in the pipe does not flow initially. The initial values of all zones were set to zero, and the calculation convergence precision of each variable was 0.001.xoy cross section passing through the robot center) in the pipe, so that the CCD camera was able to continuously capture the image of the tracer particles in this plane. After data processing, the velocity field of the fluid at the tracer particles could be solved; that is, the fluid field of the xoy plane near the capsule robot was also obtained. The tracer particles were hollow glass beads with density of 1.05 g/cm3 and diameter of 8–12 μm, and have good flow followability.To verify the CFD method used in this paper, particle image velocimetry (PIV) technology was used to measure the fluid flow field. As shown in According to the working principle shown in xoy plane through the center of the capsule robot when the robot precesses in a pipe with a diameter of 18 mm filled with silicone oil with dynamic viscosity of 0.02 Pa·s, at the robotic translational speed v of 0.05 m/s and robotic rotational speed n of 60 r/min. The zero point of the x-axial coordinate passes through the center of capsule, and the zero point of the y-axial coordinate passes through the bottom of pipe. In the experiment, the pipe diameter shown is slightly larger than 18 mm, which is due to the refraction of light passing through the glass pipe.The trajectory of the fluid streamline around the capsule robot is a circular line from the head of the capsule to the end of the capsule. A large fluid vortex is formed at the bottom of the robot, and the fluid velocity is larger in the middle of the region between the capsule and the pipe. The experimental results show that the overall distribution of fluid streamline around the capsule robot is basically the same as the numerical results, but the streamline in a few regions is slightly chaotic and the fluid velocity is slightly different. This is as, in the experiment, the capsule robot precesses in a slight swing mode.−1. If a vorticity source exists, vortices of different sizes will be produced. The direction of the vorticity is determined by the right hand rule. When the right hand clenches the fist, the direction of four fingers is the fluid rotational direction, and the thumb points to the direction of vorticity [Vorticity is usually used to measure the magnitude and direction of a vortex, and is defined as the curl of the fluid velocity vector, with unit sorticity .U represents linear velocity; and ω represents rotational angular velocity.The larger the vorticity of the fluid around the capsule robot, the greater the fluid rotational intensity, the more chaotic the fluid flow field, the greater the fluid turbulent intensity near the robot, and the worse the stability of the robot. The vorticity is calculated as follows.x-axial positive direction is horizontal to the left, and the y-axial positive direction is vertical to the down. x-axial component xu of the fluid velocity on the y-axis below the capsule robot in the coordinate system shown in xu is to the left, which is opposite to the direction of the robotic translational velocity. Its value first increases, then decreases from the bottom center of the robot to the pipe bottom. The change trend and numerical value of CFD calculation and PIV measurement results are consistent.To quantitatively compare the calculated values with the measured values, as shown in z-axis on the y-axis below the capsule robot in the coordinate system shown in z-axis is linearly changed from positive to negative; that is, the rotational direction of the fluid is changed, and the vorticity value first decreases and then increases. In particular, the numerical results of vorticity in the fluid region near the robot are very close to the experimental results. The agreement between the numerical results of velocity and vorticity and the experimental results proves that the CFD method used is feasible and accurate.In this section, we examine whether the operating performance of the capsule robot is affected when the pipe is bent. Intestinal peristalsis is a normal physiological phenomenon of the human body. It is a continuous and coordinated contraction of the circular and longitudinal muscles. It occurs at the proximal end of the small intestine and spreads to the distal end of the intestine. The spread rate is 0.5–2.0 cm per second, and the spread frequency is 8–11 times per minute.t is time.In numerical calculations, as peristalsis of a pipe is more difficult to simulate, we assumed that the fluid in the pipe flows according to the spread rate and frequency of intestinal peristalsis to replace the pipe peristalsis. Assuming that the intestinal velocity is 2 cm/s at 9 times/min, the fluid velocity at the inlet of the pipe is as follows:The orthogonal design method is an efficient, economic, and rapid experimental design method for multi-factor and multi-level problems. Compared with traditional experiment methods, it requires less time and has higher efficiency. As the orthogonal table has the advantages of “uniform dispersion and neat comparison”, the analysis of the orthogonal test results provides a comprehensive understanding of the test situation, and allows optimal test results to be obtained with as few tests as possible.rF, which affects the passing capacity of the robot; the fluid turbulent intensity near the robot tI, which affects the operating stability of the robot; and the maximum fluid pressure on the pipe wall mP, which affects the degree of damage to the pipe. According to the three indicators, the influence of the relative degree, significance, and optimal combination of various parameters of the robot system were studied by orthogonal numerical calculation.When the capsule robot precesses in a pipe filled with mucus, the operating performance indicators of the robot include: the forward resistance of the robot d, robotic translational speed v, robotic rotational speed n, and fluid viscosity η, which are represented by A, B, C, and D, respectively. Five levels are set for each factor, and the level value of each factor is more uniformly chosen in the reasonable operational condition of the intestinal capsule robot, thus forming an L25(54) orthogonal table [Referring to al table . The fou4) numerical calculation schemes, 25 typical schemes were selected, as shown in Due to the size of the calculation required for 625 , B (v), C (n), and D (η); i = 1, 2, 3, 4, and 5.j and the level number i; and ijr is the calculation time for the factor in column j and the level number i.Let jR is defined as the difference between the maximum value and the minimum value of the statistical parameter j.The range analysis method is used to analyze the influencing degree of each factor on the calculation indicators by comparing the range of each factor. The range R. The greater the range R, the greater the influence on the calculation indicator when the factor level is changed. Therefore, the factor with the largest range R is the main factor.The range reflects the relative influence of each factor on the calculation indicator. The influencing degree of factors can be directly judged by Through the range analysis of the three performance indicators of the capsule robot at the same level and the same factor in rF is as follows: fluid viscosity > robotic translational speed > pipe diameter > robotic rotational speed; the relative influencing degree of various factors on the fluid turbulent intensity near the robot tI is as follows: fluid viscosity > robotic translational speed > robotic rotational speed > pipe diameter; and the relative influencing degree of various factors on the maximum fluid pressure to the pipe wall mP is as follows: fluid viscosity > pipe diameter > robotic translational speed > robotic rotational speed. It can be concluded that, during the precessing process of a capsule robot in a pipe filled with mucus, the changes in various parameters have different effects on each performance indicator of the capsule robot. Among these, the fluid viscosity has a greater impact on all performance indicators, whereas the robotic rotational speed has a smaller impact on all performance indicators.The order of importance among the influencing factors can be judged by the range analysis. However, to objectively judge the influencing significance of each factor on the calculation indicators, variance analysis is needed.jS. The other is the variation caused by the calculation error. In the orthogonal design, the error is represented by setting a blank column. Therefore, the corresponding variance analysis is expressed by the squared sum of the group difference eS in the blank column.r is the calculation time of each factor with the same level number; p is the level number of each factor; j-th factor and level number a; aby is the calculation indicator value.In variance analysis, the degree of variation of calculation data is composed of two parts. The first is the variation of calculation indicators caused by the change in each factor’s own level, which is represented by the squared sum of the group difference jS, the greater the influence of the factor level change on the indicator. The values of jS and eS are related to their own degrees of freedom jf and ef.jf is the degrees of freedom of jS; jr is the calculation time of the j-th factor with the same level number; tf is the total degrees of freedom; n is total calculation time; eand f is the degree of freedom of eS.The basic idea of variance analysis is to calculate and compare the above two parts of variation, and the significance level of the corresponding factors on the calculation indicators is determined using a hypothesis test. Equation (8) shows that the larger the value of jS and eS, the hypothesis test is carried out to judge the significance of each influencing factor. For example, it is assumed that the fluctuation of factor j has a significant impact on the indicator. On the premise of this assumption, it is concluded that the statistic jF, which is related to jS and eS, obeys the F distribution:α is the significance level.After obtaining jF, the test p-value corresponding to the F-value can be obtained by looking up the F distribution table. Analysis of variance shows that: if jF > F0.01, the factor is highly significant, and is expressed by “****”; if F0.01 > jF > F0.05, the factor is significant, and is expressed by “***”; if F0.05 > jF > F0.1, the factor has an influence, and is expressed by “**”; if F0.1 > jF > F0.2, the factor has a certain influence, and is expressed by “*”; and if j < FF0.2, the factor has no influence, and is expressed by “/”.After calculating rF, the fluid viscosity has a certain influence, and the other three factors have almost no influence. For the performance indicator tI, the fluid viscosity has a highly significant influence, the robotic translational speed has a significant influence, the robotic rotational speed has a certain influence, and the pipe diameter has almost no influence. For the performance indicator mP, the fluid viscosity and the pipe diameter have a certain influence, and the other two factors have almost no influence. The above research shows that the fluid viscosity is an important factor that affects the passing capacity, stability, and non-invasion of the capsule robot; the translational speed of the robot plays an important role in its operating stability; and the pipe diameter is also an important factor that affects the damage of the pipe wall caused by the fluid pressure.rF, tI, and mP) of the capsule robot in the pipe filled with mucus, the parameters of the capsule robot system were optimized, and the parameters with the minimum level mean value of the performance indicators of the capsule robot were selected.According to the three performance indicators A set of drive systems for a capsule robot in a pipe driven by an external permanent magnet, and a measurement system of the fluid flow field in the pipe during the robot’s precession, were designed and manufactured. The velocity of the fluid in the pipe of the capsule robot was calculated using the CFD method and measured using PIV technology. The numerical calculation values and experimental measurement values were similar, which verifies that the CFD method used in this paper is feasible and accurate. Furthermore, the performance of the capsule robots was numerically analyzed and compared in complex environments of a curved pipe and peristaltic flow;(2)Range and variance analysis in orthogonal design was used to analyze the relative degree and significance of the influence of pipe diameter, robotic translational speed, robotic rotational speed, and fluid viscosity on the three performance indicators of the capsule robot. The fluid viscosity is an important factor that affects all the operating performance indicators of the capsule robot;(3)Using the best passing capacity and operating stability of the capsule robot, and the minimum damage to the pipe, as the optimization objectives, the optimal combinations of various parameters of the capsule robot system were designed;(4)Numerous factors affect the operating performance of the capsule robot, such as structural parameters of the robot, pipe characteristics, and magnetic field parameters. These parameters need to be studied. In addition, the interaction of various factors was not considered in this study. These issues will be studied in the future;(5)The CFD method, PIV technology, and orthogonal design method used in this paper can be widely used in the calculation, measurement, and optimization of the fluid field of in-pipe capsule robots in a liquid environment.


Journal of Molecular Cell Biology (2021), 13(6), 433‒444, https://doi.org/10.1093/jmcb/mjab018Funding section), the DoD grant support number listed in the original publication was incorrect. The grants that supported this work were National Cancer Institute grant (R01CA200232-05) and Department of Defense Grant (W81XWH-16-1-0025) both to C.G.M. The corrected text should be as follows:In this article  and a Department of Defense (DoD) Grant (W81XWH-16-1-0025) both to C.G.M. and by grants from National Heart, Lung, and Blood Institute  to L.A.B.


In the Funding section, the funding source the Higher Education Sprout Project by Ministry of Education (MOE) was omitted. The correct funding statement is: “The research and publication charge were supported by the Ministry of Science and Technology (MOST) in Taiwan (grant number MOST109-2221-E-038-018) and the Higher Education Sprout Project by Ministry of Education (MOE) in Taiwan (grant number DP2-110-21121-01-A-13) to Emily Chia-Yu Su. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. There was no additional external funding received for this study.”