At one year, stroke and major bleeding rates did not differ between the ICE and TEE groups. A Watchmann FLX device showed high technical and procedural success rate, and ICE guidance does not appear inferior to TEE.This study aimed to compare the peri-procedural success and complication rate within a large registry of intra-cardiac echocardiography (ICE)- vs. transesophageal echocardiography (TEE)-guided left atrial appendage occlusion (LAAO) procedures with a Watchmann FLX device. Data from 772 LAAO procedures, performed at 26 Italian centers, were reviewed. Technical success was considered as the final implant of a Watchmann FLX device in LAA; the absence of pericardial tamponade, peri-procedural stroke and/or systemic embolism, major bleeding and device embolization during the procedure was defined as a procedural success. One-year stroke and major bleeding rates were evaluated as outcome. ICE-guided LAA occlusion was performed in 149 patients, while TEE was used in 623 patients. Baseline characteristics were similar between the ICE and TEE groups. The technical success was 100% in both groups. Procedural success was also extremely high (98.5%), and was comparable between ICE (98.7%) and TEE (98.5%). ICE was associated with a slightly longer procedural time (73  Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting 3–5% of people older than 65 years ,2. Oral In last years, new devices or new versions of past devices have emerged. Watchman FLX represents an upgrade of the Watchman family devices. In comparison to the old version of the device, Watchman FLX has greater flexibility and reduced height, with a higher number of anchoring elements, improved fabric coverage and a closed distal end. All these modifications are aimed for an easier implantation, safer recapture and repositioning, with the potential for reduction in the follow-up of device-related thrombosis and peri-device leaks. The high flexibility of the device permits for a significant oversize (in order to limit the device embolization risk), without increasing the risk of perforation. Watchmann FLX has demonstrated optimal safety and efficacy results, with a low rate of procedural complications.On the other hand, intra-procedural imaging may significantly affect procedural outcome. The optimal way to guide an LAAO procedure has not been completely defined. The use of fluoroscopy without other imaging modality should be strongly discouraged, as it is inadequate for a detailed guidance of an LAAO procedure. Transesophageal echocardiography (TEE) has been the most common imaging modality adopted for LAAO guidance. It is well known by many cardiologists in the context of standardized imaging and optimal visualization of the LAA, atrial septum, left and right atria. Nevertheless, the needed general anesthesia and dedicated operator are two main limits of TEE use. Moreover, interference with fluoroscopy, as well as the potential for upper gastrointestinal tract damage, is another factor that may affect TEE use. Intra-cardiac echocardiography (ICE) has been developed as an alternative to TEE for LAAO procedure guidance. ICE probes are commonly advanced through the right femoral vein, and positioned close to the structure of interest for an LAAO in the right and, after transeptal puncture, in the left atria. Available data suggest that ICE is not inferior to TEE for guiding LAAO procedures, both for immediate results  and long-term patient outcomes ,8,9. A lIn the present work, we aim to compare ICE to TEE guidance for an LAAO procedure within a large Italian registry of LAAO procedures performed with the Watchmann FLX device. 2DS2-VASc [We prospectively enrolled 772 patients that underwent LAA occlusion procedures at 26 Italian centers, between October 2018 and September 2021. Procedural and follow-up data were collected. Patients with non-valvular atrial fibrillation, a CHA2DS2-VASc score ≥ 2 and relative/absolute contra-indication for NOACs were included. The CHADS2-VASc  and HAS-DS2-VASc  scores wAll procedures were performed with the Watchmann FLX device . The device was recapturable and repositionable at any moment. A higher number of open-frame cells increases device conformability, while a closed end facilitates device implantation when the length of the LAA is limited (minimum required length is 50% of the device size). The risk of perforation is limited by the presence of an atraumatic distal end with a fluoroscopic marker. This design permits for device advancement within the LAA when partially exposed in a “ball” configuration. Still, the polyester fabric coverage has been extended to minimize peri-device leaks. The device is available in five sizes, namely 20, 24, 27, 31 and 35 mm for LAA ostia sizes ranging from 14 mm to 31.5 mm.Preprocedural evaluation and planning was performed with transesophageal echocardiography (TEE) or cardiac computed tomography (CT), according to the local practice. LAA dimensions and morphology were evaluated, as well as the morphology of intertribal septum and fossa ovalis. The landing zone (LZ) was measured at the LAA ostium, from the level of the circumflex coronary artery to a point 1-to-2 cm distal to the left upper pulmonary vein ridge. Three-dimensional reconstruction was used. The device sizing was selected according to the maximal LAA LZ diameter, with target oversizing between 10% and 30%. Patients with LAA thrombosis were excluded. TEE or ICE were used during the procedure for guidance of the different phases, namely transseptal puncture, LAA morphology and size reevaluation, LAA incanulation, device delivery and implantation . Procedural complications were promptly evaluated. TEE procedures required general anesthesia. ICE procedures required an adjunctive ipsilateral femoral vein access and were performed under local anesthesia. An alternative use of ICE or TEE was left to the operator discretion and TEE/ICE availability.For optimal ICE guidance, an ICE probe was advanced into the left atrium during every ICE-guided procedure, through the first transseptal puncture, as described elsewhere.Technical success was defined as the final deployment of the device inside an LAA, fully meeting the PASS criteria . Procedural success was defined as technical success without major procedure-related complications . Major bleedings were defined according to the International Society on Thrombosis and Haemostasis criteria . Events Follow-up was performed by clinical visits or telephonic follow-up. No oral anticoagulation therapy was administered after the procedure. Different pharmacological schemes were adopted after the procedure. The most common scheme included dual antiplatelet therapy with aspirin (100 mg/die) plus clopidogrel (75 mg/24 h) for 30 to 180 days after the procedure. According to operators’ discretion, in patients with high bleeding risk, a single antiplatelet agent was prescribed with/without adjunction of a prophylactic dose of low-molecular-weight heparin for the first month after the implant procedure. Stroke, transitory ischemic attacks (TIA), systemic embolism, major/minor hemorrhage and death from cardiac or any cause were considered as events. Patients that had a one year follow-up were considered for the outcome analysis. ® . A p-value less than 0.05 was considered significant.Continuous data were expressed as the mean ± standard deviation. The procedural success rate was calculated as a percentage over the total number of procedures. For proportions, numbers and percentages were used. The differences between TEE and ICE groups were evaluated with the Student t-test for continuous variables. Binary logistic regression analysis was used to evaluate the occurrence of complications in the TEE and ICE groups, respectively. The odds ratios and 95% confidence intervals were calculated. Events curves were analyzed using the Kaplan–Meier estimate. The differences in survival curves were tested with a log-rank test. Statistical analysis was performed using SPSSThe baseline characteristics, as well indications for LAAO, are displayed in 2DS2-VASc was 4.1 and HAS-BLED 3.6, with no differences between TEE and ICE patients. Of patients, 91% in the TEE group and 8% of ICE patients underwent pre-procedural three-dimensional TEE, while pre-procedural CCT was performed in 10% of the patients in the TEE group and 94% of ICE patients, respectively.Of the total of 772 procedures, ICE-guided LAA occlusion was performed in 149 patients, while TEE was used in 623 patients. Clinical characteristics and indications for the procedure were similar between the groups, but patients in the ICE group had a higher prevalence of hematologic disorders. About 50% of the patients had a permanent AF, without any difference between TEE and ICE patients. CHAp = 0.042) and fluoroscopy times  in comparison to the ICE group. On the other side ICE patients had shorter hospital stay . No differences in the number of attempts for device positioning, as well as the number of device opened, were assessed between the ICE and TEE groups. The overall technical success was 100%, with the final fully meeting the PASS criteria for all procedures. Procedural success was similarly high, with no differences between the TEE (98.5%) and ICE (98.7%) groups and a complication rate of 1.5% for the TEE vs. 1.3% for the ICE, respectively. The most common complication was major pericardial effusion for both groups, followed by major bleeding. Of the pericardial effusions, 25% required drainage, 0.55% in the ICE group and 0.47% in the TEE group. Any case of device embolization was reported, as well as any case of peri-device leak > 5 mm that occurred. Procedural complications in the ICE- vs. TEE-guided procedure groups are visualized in The use of ICE was associated with longer procedural  and major bleeding (2.9% in the ICE group vs. 3.7% in the TEE group) were similar between the ICE and TEE groups  a Watchman FLX device ensures high procedural safety and technical success; (b) ICE intra-procedural guidance for LAA occlusion does not appear to be inferior to TEE in terms of procedural complications and one year follow-up outcomes.In the last 20 years, LAAO has been demonstrated as a viable alternative to (N)OACS in NVAF patients with absolute/relative contraindications to anticoagulation. Specifically, LAA occlusion reduces about 70% of the rate of cerebral embolism as compared to historical NVAF populations without OAC, at the same time warranting a 60% reduction in the rate of hemorrhagic events as compared to historical populations under OAC treatment .In this context, procedural safety is a key element. LAAO history has been characterized by progressive amelioration of the procedural safety profile, making LAAO more attractive. A low rate of procedural complications is crucial in order to implement LAAO in current clinical practice as a potential alternative to NOACs, also in patients who could tolerate this therapy.Two main procedural aspects need full consideration regarding procedural safety. The first element is about technical equipment and, specifically, the device. Different devices have been developed. The Watchmann family devices have been the most studied devices both, in randomized trials  and regiThe second main aspect for improving procedural safety lays on accurate pre- and intra-procedural imaging. Pre-procedural-computed tomography or 3D high-quality TEE are essential. They inform about interatrial septum anatomy and its spatial relationship with the LAA , and must give full elucidation of LAA morphology. LAA has a wide variety of anatomical aspects, width of its neck, length, orientation and the presence of additional lobes must be fully analyzed before the procedure.Intra-procedural imaging guides the procedure, from transeptal puncture to the device implantation and final assessment. TEE has historically been considered the gold standard for intra-procedural guidance. TEE certainly has a high definition of the right and left atria, atrial septum and left atrial appendage anatomy, and it is an imaging modality that is well known by many invasive cardiologists with largely standardized imaging. Nevertheless TEE may be affected by some limitations. First, TEE requires general anesthesia with a longer patient turnover and increased procedural time, implying the presence of an anesthesiologist. Still, general anesthesia may be harmful in fragile patients and may require intensive care monitoring after the procedure. Finally, TEE and endotracheal intubation may contribute to complications such as the injuries and bleeding of gastroesophageal and respiratory tract, laryngospasm and bronchospasm. requiring additional intervention and prolonged hospitalization . ICE hasIn this registry, ICE did not appear inferior to TEE in terms of procedural safety and follow-up results, using a very-well-performing device. The procedural success appears to be extremely high. In particular, the absence of device embolization and peri-device major leaks attest the high performance of this device, not affected by the choice of ICE or TEE guidance. TEE has lower fluoroscopy time, procedural time and contrast volume vs. ICE in this registry. These differences are likely linked to a higher standardization and operators experience with TEE guidance. A longer procedural time may be reduced in the future by higher operator experience, and, in any case, is counterbalanced by a lower cathlab turnover time and less invasiveness than ICE.2DS2-VASc and HAS-BLED scores of the studied population.Still, one year thromboembolic and hemorrhagic event rates are extremely low, both in the ICE and TEE groups, if related to the CHAThese considerations pave the way for broader indications for an LAAO procedure. First, randomized trials are ongoing, evaluating the comparison between novel anticoagulants and LAAO. The results are awaited in the next months, and it is likely that many patients could also tolerate oral anticoagulant therapy, a potential candidate for LAAO. In this context, there is potential for a larger use of a combined procedure of LAAO and AF ablation. Patients that undergo AF ablation are also natural candidates to LAAO if this procedure shows good safety and efficacy .As for many other fields of clinical practice, it is likely that artificial intelligence will impact on the indications and the way cardiac structural intervention performance. Some experience of pre-procedural planning and procedure simulation driven by artificial intelligence has been already published for LAAO ,19. In tThe main limitation of this study is the lack of randomization between ICE and TEE use. In this series, ICE was used mainly at centers with a high volume of LAA occlusion procedures. Follow-up data were available only for patients that achieved 1 year follow-up, which is actually about half of the study population. The study is largely underpowered to draw a definite conclusion about the follow-up.A Watchmann FLX device has very high technical and procedural success rates. ICE guidance does not appear inferior to TEE in terms of procedural results and outcomes.


Interfragmentary strain affected only the 600 N load (p < 0.01) for the bicortical conventional type (group BC), and the screw configurations that were influenced were 1234 and 123 (p < 0.05). The low steepness of the slope indicates the least εIFM for the corresponding biomechanical characteristic in good-quality stability. A strain value of ≤2% promotes callus formation and is classified as absolute stability, which is the minimum required value for the induction of callus and the maximum value that allows bony bridging. The outcomes have provided the correlation of screw configuration in femoral midshaft transverse fracture implantation which is important to promote essential primary stability.An understanding of the biomechanical characteristics and configuration of flexible and locked plating in order to provide balance stability and flexibility of implant fixation will help to construct and promote fast bone healing. The relationship between applied loading and implantation configuration for best bone healing is still under debate. This study aims to investigate the relationship between implant strength, working length, and interfragmentary strain (εIFM) on implant stability for femoral midshaft transverse fractures. The transverse fracture was fixed with a fragment locking compression plate (LCP) system. Finite element analysis was performed and subsequently characterised based on compression loading (600 N up to 900 N) and screw designs  with different penetration depths . Strain theory was used to evaluate the stability of the model. The correlation of screw configuration with screw type shows a unicortical depth for both types ( Orthopaedic bridge-plating fixation has been studied extensively. Bone-healing studies have highlighted the complications involved in the delayed union, non-unions, fracture after device removal, and infection, mostly in the diaphysis and meta-diaphyseal fractures ,2. SubseAmong all the implant fixations, the locking compression plate was improved to achieve better fracture union compared with conventional plating which was stiffer in allowing bone healing. Moreover, flexibilities of the locking characteristic were necessary to enable interfragmentary motion (IFM) to directly stimulate a new bone bridge at the fracture site . The rigThe function of a bridge plating with a screw construct was developed in advance based on a stability requirement of a particular fracture. These implants act as load-sharing or load-bearing devices, depending on the fracture reduction and fragment interference . ImplantDifferent designs of bone geometry have shown different results for stress and subsequent deformations. Two-dimensional FE modelling representing the bone–implant structure is based on the assumption that the load is axially symmetrical . Most ofIn one study, the stability spectrum was scaled as a quantitative condition of implant stability . MicromoSome studies suggest that optimal screw configuration can minimise healing time and also surgical costs . ResearcIn this study, the three stages of internal implant fixation are involved which are implant–bone fixation, implant–bone loading condition, and implant–bone screw penetration. Implant fixation was studied based on the mechanical response: (i) when implant placement is performed on the femur, (ii) when the compression loading is applied on the femur bone, and (iii) there is a different type of screw and penetration depth. The four surgical fixation groups—unicortical conventional screw (UC), unicortical locking screw (UL), conventional bicortical screw (BC), and bicortical locking screw (BL)—are shown in 1–P8), and the four configurations are shown in Three parts of the fixation system were constructed: screws, a compression plate, and an intact femur bone. The intact femur model was applied before mimicking the actual bone from CT scan through the computer-aided design (CAD) model library . The modIn accordance with the Arbeitsgemeinschaft für Osteosynthesefragen/Association of the Study of Internal Fixation (AO/ASIF) procedure , the plaTetrahedron element mesh was used for all models. The interaction approach between contact pair is classified as bone–screw, implant–screw, and implant–bone. The fixation system model employed the interaction as a simple contact that was frictionless between the implant and bone surface. The friction coefficients between 0.1 and 0.3 were compared , and theA constant load of 800 N was applied once the preliminary steps were achieved. It has been demonstrated to correspond to the load on the femur during regular activities such as standing up. The rationale relation between dynamic and static loading demonstrated that the average dynamic force applied on the femur is representative of the constant load based on human weight . Sides A and B represent the compression loading and constraint, respectively, and the schematic of these four loading conditions is illustrated in The primary stability of implant fixation is related to the implant’s micromotion, which is defined as a displacement that refers to a small movement of bone fragments at the fracture site. It can be characterised by the implant’s stress analysis, working length analysis, interfragmentary strain measurement, and stability classification.The implant fixation with two screw types was modelled; subsequently, the implant strength was appropriately computed. The four screw types were simulated by four configurations at various penetration depths. The overall results were determined using the maximum von Mises stress of the implant. The mechanical properties of stainless steel were used to estimate the stress required to initiate the crack and to cause implant loosening and failure. The changing stress value affects Young’s modulus bone neighbour and causes jumps in stress values in the bone.Further investigation was carried out in simulating a relationship between working length and maximum von Mises stress by taking the average of the implant equivalent of stress for each working length. Working length refers to the distance between the two innermost screws. By omitting one screw hole on either side of the fracture, the construct became flexible in both compression and torsion. The relationship between working length and implant stress was determined, in order to differentiate the rigidity and flexibility based on screw configurations.L is changing between initial length and length under stress, and L is the initial length = 1 mm.Interfragmentary strain at the fracture gap filled by the callus was calculated using the comparison of the initial length of the fracture gap and the gap size under stress based on the end point of both bone fragment connectors with the callus. Perren’s strain theory was used for observing the implant stability. Strain values up to 2% promoted the formation of lamella tissue and at this stage can be classified as absolute stability. In addition, up to 10% are tolerated by the woven bone formation, and for between 10% and 30%, induction of resorption prevails. The interfragmentary of each construct was determined using the following equation:Implant stability was evaluated based on screw type and its configuration. Absolute stability was achieved by compression load at the fracture site, where small gaps of 1 mm are bridged by bone growth. The stabilisation at the fracture site determined the further course of bone healing . Stabili123 with a maximum of 99.24 MPa, followed by the UC124, which had a maximum stress of 76.78 MPa. The most stable construct was observed for UC1234, with a minimum stress of 64.48 MPa; moreover, this configuration had considerably larger stability than those seen for UC134, UC123, and UC124. The high stress of the implant leads to mechanical failure. However, the low stresses may cause stress shielding, which could lead to bone resorption and implant loosening [When the configurations of screw types were compared, group UC showed the highest strength of UCoosening .134. Groups UL1234, UL123, and UL124 yielding average strengths of 639.77 MPa, 900.65 MPa, and 919.59 MPa, respectively. The implant strength of Groups UC and UL was relatively higher for Configuration 1234. Subsequently, UC1234 shows the least stress value compared with UL1234. This is due to the exceeding resistive strength of cortical bone, whereas bone resorption and screw loosening occurred. This loosening occurred because of the high interfragmentary strain, which can increase micro movement at the fracture gap and subsequently change the implant stability level [Considering the locking screw construction with various screw configurations, all exhibit high values concerning the penetration depth. The maximum strength (989.26 MPa) was determined in group ULty level .134 with a maximum of 989.26 MPa, followed by UL124, which had maximum stress of 919.59 MPa. The most stable group UL construct was found to be UL1234, which had a maximum stress value of 639.77 MPa. In hindsight, group UC and group UL for C1234 were the most stable, while the UC1234 construct yielded lower stress than UL1234. This is because of an axial load exceeding the frictional force and producing a high-stress transfer to the bones and neighbouring interfaces.Compared with group UL, critical stress was found at UL123 showed the least strength (177.75 MPa), while the configurations of UL1234, UL134, and UL124 had strengths of 254.41 MPa, 254.23 MPa, and 182 MPa, respectively. In addition, for group BL, BL123 experienced the maximum stress of 99.24 MPa, which is similar to the stress experienced by the BL1234 (64.48 MPa), BL134 (70.12 MPa), and BL123 (76.78 MPa) configurations. Groups BC and BL exhibit that C123 was the most stable. This attests to an earlier suggestion that the number of screws does not necessarily equate to an increase in stability. The fewer-screw predictably will increase the load sharing for individual screws; however, the stability also can be controlled by changing the working length. A similar observation was also reported by Stoffel [Group UL Stoffel .123 (35.78 MPa) being the most stable group. The strength and deformation of the implant depend on the bending moment of plating the bridge. This bending condition varies based on the screw position and the distance between the two innermost screws.Groups BC and BL were very stable compared with groups UC and UL because both groups penetrate through the two stiff layers of the bone cortex. Shortening of the screw length results in a substantial increase in the compressive stress , whereasThe desired yield stress is in the range of 400 MPa. The stress variation has to initiate and propagate a crack with the screw and implant being estimated whereas the stress raisers will lead to the implant failure. The standing load itself  needed to be representative of the minimum strength of the human activity performed by the patient between surgery and implant failure. In addition, implant stress becomes relevant to determine the amount of transfer stress from the implant to the neighbouring bone which may affect the implant stability in terms of micro movement. The presence of the two innermost screws acts as a lever or fulcrum. These changes in distance are known as the ‘working length’. Further factors considered in the internal fixation of bone plate fixation include the implant working length.1234 had high stress concentrated at position P5, which focused on the threaded head, while the plate concentrated on the hole threaded for screws and plate. Configuration UL134 had high stress concentrated at position P8, which focused on the end of the threaded head, while the plate concentrated on the hole threaded for the screws and plate.123 showed the critical stress concentrated on the P1 screw position, and it was located on the screw head and neck. Similar observations were found at position P1, where critical stress was found in the threaded hole. The failure stress of UL1234 was higher than that for UC1234, the screw failure was shown based on the type of screw. Stress riser initiates the locking mechanism of the UL screw. Similarly, Configuration UL124 showed the critical stress concentrated on the P8 screw position, and it was located on the screw head and neck. Matching to the plate, position P8 indicated critical areas for the fracture of the thread conjunctions and screw holes. The same observations were found in UL134 and UL124. Overall observations found that the critical failure stress occurred on the screw head with the thread and the screw threaded hole. This was because critical stress transfer occurred as the locking head screw engaged and locked into the threaded plate hole.Configuration UL1234 showed the critical stress concentrated on the screw at position P8, and it was located on the proximal thread. Similar findings were observed for BC134 and BC123. The results are in good agreement with those reported by Lofaj et al. [134 showed the critical stress concentrated on the position P5 screw position and was located on the screw head and neck. Similar to the plate, position P6 showed a critical area located at the screw hole with thread conjunction and screw holes near the fracture site. Similar plate stress concentrations were also observed for UC1234, UC134, and UC123.j et al. . Unlike 123 showed that critical stress occurred on the screw and neck. For the plates, the critical stress concentrated on position P6 in the conjunctions of screw holes with thread and screw holes near the fracture site. A similar observation was made for BC124, where greater stress was obtained on position P1 for both implants. This is caused by a load transfer from the proximal fragment to the distal fragment through the plate. Most of the critical stress occurred on the distal fragment and concentrated on the screws innermost from the fracture site.Position P3 of BC1234, C134, and C124 generated an 8 mm working length compared with C123 of both types of penetration, which provided a 16 mm working length. The working length and screw configuration were more important than the number of screws [f screws , whereasThe average of maximum von Mises plate strengths of Groups UL and BL showed that the bicortical screw had more significant changes in plate stress. Increasing the working length from 8 mm to 35 mm reduced the plate stress by 98.33 MPa to 35.78 MPa, respectively. Under axial loading, the reduction for 35 mm was approximately 60% of 8 mm. For the unicortical screw, 8 mm of working length (91.99 MPa) showed a higher stress value compared with 35 mm (55.42 MPa), as shown in The wider working length decreases the equivalent stress in the implant. The working length enables early mobilisation and bone bridges in the fracture gap to occur , whereas1234 to C124. Absolute stability was achieved in all configurations of bicortical screws compared with the unicortical group. In addition, relative stability was obtained for both types of unicortical screw groups for all configurations except C1234, where it showed a value of less than 2% strain. This result was not reported as a strategy for optimising fixation stability for these types of screws, for screw position relative to the fractured bone.In bicortical groups, the amount of strain gradually increased as the pattern of screw configuration changed from CCompression applied to the fracture produced preloaded continuous contact and, thus, minimised interfragmentary strain. This enabled the osteons to cross the fracture at the compressed surfaces. The osteons may also cross small gaps stabilised by neighbouring compressed areas of contact. However, the minimal strain did not induce the formation of callus. The displacement of the implant micromotion affected the net resorption that begins to bond the gap, while its tension depended on the tolerable limit of soft tissue formed. This can lead to a reduction in the stress-shielding effect. The closer of the innermost screws to the fracture site resulted in a more significant impact on the interfragmentary strain εIFM rather than the number of screws itself. The findings are supported by Lee et al. . They reThe effects of each type of screw and their configuration were estimated using the residual sum of squares by using 95% of the confidence interval for the parameters. p-value obtained from the normality test and shows a significant level fitting to assess the null hypothesis. The screw configuration of C1234, C134, and C123 concluded the model is statistically significant based on non-linear regression as the p-value obtained (p ≤ 0.05) compared to the configuration 124 (p ≥ 0.05). The value of εIFM is statistically significantly different between the screw configurations and compression loads. In these results, the normality of distribution also performed by Shapiro–Wilk indicates a p-value > 0.1. Thus, the null hypothesis is accepted for all screw configurations and loads for all input response influence on εIFM.As shown in p-value computed for the C1234 and C124 shows an uneven spreading of residual across the fitted line, indicating a non-constant variance as it is far away from a zero value, 0.7048 and 0.9432, respectively.The constant variance test results show the εIFM passed the test of the assumption that the variance of loads in the screw configuration takes a small variance. The a and b are constants, while a and b are shown in Equation (2). From the regression analysis, the relationship between interfragmentary strain and compressive load can be linearised as Equation (5):−3) compared with other configurations, which indicates the least interfragmentary strain and the most-stable construct. It also explains that replacing locked with nonlocked diaphyseal screws does not significantly decrease construct stiffness and does not enhance interfragmentary motion [Equation (2) and y motion .p < 0.01) for 700 N and 800 N of load. The screw configuration for 134 and 124 had a substantial effect on the result of the interfragmentary strain (p < 0.05) for both configurations. Moreover, group BC indicated that interfragmentary strain had an effect only for 600 N (p < 0.01), and the screw configurations influenced were 1234 and 123 with a significant value (p < 0.05). This relationship is related to the location of bone formation and resorption which explained the high and low local mechanical strain [l strain .p < 0.05), indicating a favourable correlation with screw configuration mainly for group UC (p < 0.01). Moreover, the screw configuration under the load is not significant (p > 0.05) for 900 N.−3) and highest for group UC, suggesting appropriate sampling distributions for the hypothesis for the strain result. Under compression loading, screw type shows a significant effect (p < 0.01) on the interfragmentary strain. The correlation of screw configuration with screw type shows a noteworthy impact on group UC and UL, having a significant value (p < 0.01) for 700 N and 800 N of the load and p < 0.05 for the configurations of C134 and C124. The interfragmentary strain had an effect only for 600 N (p < 0.01) for group BC and the screw configurations that were influenced were C1234 and C123 (p < 0.05). Moreover, the slope response of ε against the load was steeper, owing to the less stable bone–implant model. The amount of strain optimally ranged between the minimum required for the induction of callus and the maximum that allows bony bridging. Strain values ≤ 2% promote the callus formation and were classified as absolute stability. The correlation between εIFM and the type of screw showed scattered data of low quality for all types of screws mainly for bicortical conventional or group BC. Thus, the obtained determination coefficient was higher to achieve a reliable prediction of stability. If it is desirable to use group BC and C134 or BC134, it is recommended. This is important to address the biomechanical characteristics of flexible and locked plating to provide a balance between the stability and flexibility of implant fixation constructs and directly promote secondary bone healing. There is an excellent linear correlation between compression loading and screw type. For future research, a similar study can be conducted for different dynamic loading which can medically explain the more actual condition of a fracture. New exploration on the effect of screw configuration at microscale levels that concentrates on the area of the bone–implant interface is highly recommended.In summary, a bone–implant fixation system consisting of different types of screws with different penetration depths  was developed and investigated. The regression slope of compression was found to be the lowest for group BC (slope = 1.64 × 10


Most cases of port-site hernia were due to inadequate fascial closure of the port site. We experienced a rare case of hernia incarceration under the closed port-site fascia despite adequate closure of the fascia after robot-assisted laparoscopic radical cystectomy. In this case, the small intestine was incarcerated between the transversus abdominis and oblique abdominal muscles from the 12-mm trocar site for the assistant. We inserted forceps to release the incarceration, and the fascia and peritoneum of the port site were closed using a trocar site closure device under laparoscopy. We considered that all-layer suturing, including peritoneum and inner and outer oblique fascia suturing, was necessary for port-site closure, especially in patients with obesity, because hernias can occur with fascial closure alone. In recent years, robot-assisted laparoscopic surgery has become widely used as a standard procedure in the field of urology, enabling less invasive treatment ,2. Port-A 70-year-old Japanese man  was diagnosed with Bacillus Calmette-Guérin refractory bladder cancer (cTis N0 M0). He underwent RARC with an intracorporeal ileal conduit-urinary diversion and extended pelvic lymphadenectomy. The trocar placement is shown in Figure He had no significant past surgical history. The total operative and console times were 722 and 593 min, respectively. The estimated blood loss volume was 240 ml. We closed the fascia of all the ports by using an absorbable suture. The early postoperative period was uneventful. The patient resumed oral intake on the seventh day after the surgery. Eight days after the surgery, he complained of severe abdominal pain and nausea. Abdominal computed tomography revealed herniation of the small intestine from the 12-mm trocar site for the assistant (Figure An emergency explorative laparotomy revealed that the small intestine was partially prolapsed from the 12-mm trocar site Figure .We placed a 5-mm port at the first arm port for RARC and inserted forceps to release the incarceration Figure . We obseWe experienced a rare case of hernia incarceration under the closed port-site fascia despite adequate closure of the fascia. The occurrence of port-site hernias is related to procedural and patient factors. The former includes trocar type, diameter, insertion position, presence or absence of fascial closure, thread type, and insufflation pressure, while the latter includes age, body mass index, and presence of wound infection ,10. In tWhen re-operation is performed after the development of a port-site hernia, either an open or laparoscopic procedure is chosen . In thisWe considered that all-layer suturing, including peritoneum and inner and outer oblique fascia suturing, was necessary for port-site closure, especially in patients with obesity, because hernias can occur with fascial closure alone. A trocar site closure device under laparoscopy is also useful because it allows for the secure closure of the port site.We report a case of port-site hernia after RARC. This complication occurs at a certain rate even in the absence of applicable procedural and patient factors, and efforts should be made to employ techniques to reduce it, and to detect it early. The laparoscopic procedure is also useful for port-site hernia repair after robotic surgery and should be the first technique attempted.


Then, in vitro α-glucosidase and cholinesterases inhibitory actions of the water-soluble 3a, 4a, 5a were examined using spectrophotometric methods. 4a had the highest inhibitory effects among the tested compounds against α-glucosidase due to IC50 values. 4a and 5a had 40 fold higher inhibitory effects than the positive control. For cholinesterases, the compounds showed significant inhibitory actions that of galantamine which was used as a positive control. According to the SI value, 3a inhibited acetylcholinesterase enzyme selectively. In kinetic studies, 4a was a mixed inhibitor for α-glucosidase, 3a was a competitive inhibitor for AChE, and 4a was a mixed inhibitor for BuChE. The therapeutic potential of these compounds has been demonstrated by in vitro studies, but these data should be supported by further studies.In this paper, we have prepared peripherally tetra-({6-[3-(diethylamino)phenoxy]hexyl}oxy substituted cobalt(II), copper(II), manganese(III) phthalocyanines ( Diabetes Mellitus (DM), which is a metabolic disease that occurs in advanced ages and is characterized by hyperglycemia, causes health complications such as retinopathy, nephropathy, cardiovascular disease, and obesity ,2. ContrAlzheimer’s disease (AD), is one of the neurodegenerative diseases that progresses over time and has limited treatment ,12. ThisPhthalocyanines have been used in various biological and industrial areas such as photodynamic therapy , anticanThe used materials, equipment, and in vitro inhibition assay on α-glucosidase, AChE, and BuChE are given in supplementary information.(1) , 4-nitrophthalonitrile , dry K2CO3  were dissolved in DMF (15 mL) at 60 °C under N2 atmosphere for 4 days. Then, reaction mixture was poured into water (200 mL) and stirred for 3 h. After that, the aqueous phase extracted with chloroform (3 × 50 mL). The combined extracts were dried over anhydrous MgSO4 and then filtered. The product was purified by aluminum oxide column chromatography using CHCl3. Yield: 0.5 g (34%). IR (ATR), ν/cm−1: 3075 (Ar–H), 2942–2870 (Aliph. C–H), 2230 (C ≡ N), 1598, 1501, 1473, 1394, 1315, 1281, 1255, 1213, 1169, 1096, 1022, 919, 803, 758. 1H NMR , (δ): 8.01 , 7.72 , 7.42 , 6.98 , 6.22 , 6.12–6.08 , 4.11 , 3.88 , 3.28–3.23 , 1.73–1.66 , 1.45–1.39 , 1.05 . 13C-NMR , (δ): 162.48, 160.39, 149.14, 136.16, 130.19, 120.66, 120.46, 116.70, 116.68, 116.17, 106.16, 105.00, 101.20, 98.61, 69.41, 67.30, 44.09, 29.19, 28.61, 25.69, 25.52, 12.88. MS (ESI), (m/z) calcl. 391.50; found: 391.70 [M]+.6-[3-(Diethylamino)phenoxy]hexan-1-ol (2) , 0.12 mmol related metal salts  in 1-pentanol (2 mL) and 1,8-diazabycyclo [5.4.0]undec-7-ene (DBU) (3 drops) was heated at 160 °C for 1 day. The product was precipitated with n-hexane. Finally,  were purified by aluminum oxide column chromatography using CHCl3.4-({6-[3-(Diethylamino)phenoxy]hexyl}oxy)phthalonitrile −1: 3066 (Ar–H), 2920–2850 (Aliph. C–H), 1729, 1607, 11497, 1488, 1467, 1357, 1232, 1214, 1178, 1094, 820, 748, 654. UV–Vis (DMF) λmax nm (log ɛ): 668 (4.93), 609 (4.51), 328 (4.92). MALDI-TOF-MS m/z calc. 1624.95; found: 1624.56 [M]+.Yield: 20 mg (20%), m.p. >250 °C. IR (ATR), ν/cm−1: 3071-3038 (Ar–H), 2968–2855 (Aliph. C–H), 1607, 1570, 1498, 1465, 1388, 1343, 1238, 1214, 1119, 1093, 956, 820, 745, 687. UV–Vis (DMF) λmax nm (log ɛ): 680 (5.02), 617 (4.679), 341 (4.86). MALDI-TOF-MS m/z calc. 1629.57; found: 1629.28 [M]+.Yield: 26 mg (26%), m.p. > 250 °C. IR (ATR), ν/cm−1: 3071 (Ar–H), 2926–2858 (Aliph. C–H), 1603, 1496, 1464, 1341, 1240, 1214, 1123, 1074, 1052, 821, 745, 686. UV–Vis (DMF) λmax nm (log ɛ): 729 (4.98), 652 (4.59), 500 (4.36), 355 (4.85). MALDI-TOF-MS m/z calc. 1656.41; found: 1621.35 [M-Cl]+.Yield: 50 mg (47%), m.p. > 250 °C. IR (ATR), ν/cm3a , 4a , 5a  was dissolved in CHCl3 (2.5 mL), added iodomethane (2 mL) and stirred at rt for 4 days. The precipitated products were filtered and washed with CHCl3, diethyl ether.−1: 3061 (Ar–H), 2932–2859 (Aliph. C–H), 1713, 1606, 1456, 1408, 1337, 1231, 1116, 1092, 1060, 1006, 870, 823, 750. UV-Vis (DMF), λmaks (loge) nm : 671 (4.94), 608 (4.48), 327 (4.85). MALDI-TOF-MS m/z calc. 2192.71; found: 421.12 [M-4I]+4.Yield: 19 mg (70%), m.p. > 250 °C. IR (ATR), ν/cm−1: 3013 (Ar–H), 2934–2860 (Aliph. C–H), 1607, 1487, 1457, 1390, 1232, 1090, 1053, 1005, 870, 745, 689. UV-Vis (DMF), λmaks (loge) nm : 680 (5.03), 612 (4.44), 345 (4.70). MALDI-TOF-MS m/z calc. 2197.32; found: 422.24 [M-4I]+4.Yield: 20 mg (74%), m.p. > 250 °C. IR (ATR), ν/cm−1: 3019 (Ar–H), 2933–2860 (Aliph. C–H), 1602, 1457, 1391, 1338, 1235, 1119, 1054, 993, 1054, 999, 869, 745, 691. UV-Vis (DMF), λmaks (loge) nm : 728 (5.01), 661 (4.55), 500 (4.37), 367 (4.85). MALDI-TOF-MS m/z calc. 2224.17; found: 420.12 [M-Cl-4I]+4.Yield: 17 mg (65%), m.p. > 250 °C. IR (ATR), ν/cm2) was prepared by the reaction of 6-[3-(diethylamino)phenoxy]hexan-1-ol (1) hexyl}oxy)phthalonitrile (2), the [M]+ peak at 391.70 verified the suggested structure. In the IR spectra of , the sharp –C ≡ N vibrations of 2 disappeared as expected. The 1H-NMR spectra of  could not be recorded due to the paramagnetic metal ions in the ring center +, m/z = 1629.28 [M]+, m/z = 1621.35 [M-Cl]+ confirmed the proposed structure, respectively. On the other hand, the [(M-4I)/4]+ signals were observed at 421.12 [(M-4I)/4]+, 422.24 [(M-4I)/4]+ and 420.12 [(M-Cl-4I)/4]+ in mass spectra, supported the proposed structures of water-soluble , respectively. The electronic absorption spectra of  and  in DMF at room temperature are shown in −5 M. These bands confirm the monomeric behavior of the metallophthalocyanines (MPcs). The absorption spectra of  and  displayed Q bands at 668, 680, 729, 671, 680, 728 nm, respectively. The B (Soret) bands of  and  were observed at 328, 341, 355, 327, 345, 367 nm, respectively. All spectral data confirmed the suggested structure of cobalt(II), copper(II), and manganese(III) phthalocyanines  and their water-soluble derivatives .The synthesis of peripherally tetra-({6-[3-(diethylamino)phenoxy]hexyl}oxy) group substituted metallophthalocyanines and their water-soluble derivatives are given in 1-ol (1)  and 4-niperature ,32. In tg center . Also, t3a, 4a, 5a were investigated by spectrophotometric methods. Acarbose was used as a positive control. The results were tabulated as IC50 values in 50 = 60.28 ± 3.42 μM). 4a has the best inhibitory actions with 1.36 ± 0.01 μM of IC50 value among the tested compounds. 4a and 5a had an inhibitory activity about 40 times higher inhibitory activity than that of acarbose. According to the literature, Güzel et al. investigated inhibitory effects of peripheral furan-2-ylmethoxy-substituted copper and manganese phthalocyanines on α-glucosidase hexyl}oxy substituted cobalt(II), copper(II), manganese(III) phthalocyanines displayed a higher inhibitory effect on α-glucosidase than that of furan-2-ylmethoxy-substituted compounds on α-glucosidase, according to the IC50 values.In this study, in vitro anti-α-glucosidase effects the compounds cosidase . The IC5Ki) for 4a which had the best inhibitory actions on α-glucosidase. The results are given in Vmax (maximum rate) value diminished and Km value increased. This result claimed that the compound inhibited the enzyme via mixed inhibition.In this work, Lineweaver-Burk and Dixon plots were investigated to evaluate the inhibitory type and inhibition constant (50 = 30.20 ± 0.58 μM for AChE and 52.04 ± 0.55 μM for BuChE). The IC50 values of 3a, 4a, 5a were 0.65 ± 0.01 μM, 1.08 ± 0.03 μM, and 1.35 ± 0.01 μM, respectively on AChE. In addition, the compounds displayed significant BuChE inhibitory properties that of galantamine (p < 0.0001). 4a had the best BuChE inhibitory actions with 0.29 ± 0.01 μM of IC50 value following 3a with 3.06 ± 0.02 μM of IC50 value. According to the SI (selective index (IC50 = BuChE/IC50 = AChE)) values, 3a inhibited AChE selectively . The difference in the results is thought to be due to the metal effect. Frasco et al. reported the metals inhibitory effects of different metals  on AChE hexyl}oxy) substituted metallophthalocyanines (Electrophorus electricus (electric eel) , acetylthiocholine iodide (AChI) , butyrylcholinesterase (BuChE) from equine serum , butyrylthiocholine iodide (BChI) , 5,5-dithio-bis(2-nitrobenzoic)acid (DTNB) , galantamine , α-1,4-glucosidase from Saccharomyces cerevisiae , and p-nitrophenyl-α-glucopyranoside (4-pNPG)  were obtained from commercial sources. The inhibitory effects of the enzymes were performed using Thermo Scientific MultiskanTM Go Microplate Spectrophotometer using a 96-well microplate reader.All reagents and solvents were of reagent grade quality and were obtained from commercial suppliers. Acarbose , acetylcholinesterase (AChE) from α-Glucosidase inhibition assay was performed as previously reported with some modifications . Acarboscontrol-A)/Acontrol) × 100. Acontrol is the activity of the enzyme without compound and A is the activity of the enzyme with compound. The inhibitory effect of the compounds was expressed as the concentration which inhibited 50% of the enzyme activity (IC50).The in vitro AChE and BuChE inhibition actions were measured according to our previous method with some modifications . GalantaKi) values) of the compounds against enzymes [Lineweaver-Burk and Dixon plots were performed to examine kinetic parameters . Statistical analysis was performed by one-way analysis of variance (ANOVA) followed by Tukey’s tests.1ŞöhretoğluDSariSÖzelABarutBPotentilla astracanica and someisoflavones: Inhibition kinetics and mechanistic insights through in vitro and in silico studiesα-Glucosidase inhibitory effect of International Journal of Biological Macromolecules201710510621070287561972BarutBSariSSabuncuoğluSÖzelAAzole antifungal compounds could have dual cholinesterase inhibitory potential according to virtual screening, enzyme kinetics, and toxicity studies of an inhouse libraryJournal of Molecular Structure202112351302683LineweaverHBurkDThe determination of enzyme dissociation constantJournal ofAmerican Chemical Society934566586614ButterworthPThe use of Dixon plots to study enzyme inhibitionBiochimica et Biophysica Acta (BBA) – Enzymology1972289251253


We used several selection criteria  to identify a suitable area for a future base in the southern polar crater Sverdrup-Henson. Due to the higher abundance of water ice, we found that the Sverdrup-Henson site is better suited to host a base than the nearby craters de Gerlache and Shackleton. The crater floor is partly in permanent shadow and exhibits numerous signatures of water ice. Since water ice is essential for rocket fuel production and human survival, its presence is necessary for a first settlement. Sverdrup-Henson has a flat floor ideal for building and safe traversing, is accessible from the surrounding intercrater plains, and has nearby locations suitable for communications and solar power production. Thus, the Sverdrup-Henson site holds great potential for future missions. We propose further exploration of this area through in situ measurements to better constrain available resources.Robotic and manned exploration of the Moon is the next target in Solar System exploration. The availability of   •Sverdrup crater is a suitable place for a first lunar settlement•The PSR of Sverdrup contains more water detections than its neighbor craters•Sverdrup crater is easily accessible and has enough space to expand the settlement Space sciences; Astronomy; Multidisciplinary design optimization Water is an essential resource for the extraction of hydrogen and oxygen for rocket propellant,2) molecule is also a valuable resource for C and O and a proponent of chemical fuels.2 can be found as a frozen volatile at the lunar South Pole as cold traps.,,The availability of water ice per km2.,The slope of the terrain. Although the ideal base site would have a flat surface, even moderate slope angles may still be considered reasonably safe, depending on the task.3.Usable energy source. Presence of sufficient sunlight (>50% of the lunar day) for power generation by solar panels.4.Communications link. (Semi-)continuous visibility of Earth is essential for the continuity of communication, remote control of robotic operations, and crew safety and morale. Such a direct line-of-sight connection would be the most robust scenario. Although various options may be considered, such as peak-to-peak antenna relay chains, or a system of lunar polar relay satellites, we focus on the primary mechanism of direct connection from Earth.5.2, which includes part of the PSR, and the potential for future expansion.Designated area for base operations and expansion. The base site should have enough area for regular ground operations, say 81 km6.Scientific interest. The duration of the stays and the processing operations of the lunar materials to develop the settlement into a future base will make it possible to acquire samples from the highlands to understand the formation and evolution of the primary crust of the Moon, similarly as done by the Chang’e 5 mission in the maria of Oceanus Procellarum . Another study analyzed slope, energy, and ISRU but has not mentioned Sverdrup-Henson.The lunar South Pole has already been studied as a possible strategic area, particularly around Malapert Massif .,,,Based on these criteria, we identified a study area centered on the crater Sverdrup  and an older, partly underlying crater named Henson in situ sampling of a PSR.12 kg of water ice,The possible presence of water ice at both lunar poles within the PSRs was first detected by the Clementine and Lunar Prospector missions.Based on the Lunar Reconnaissance Orbiter (LRO) Lyman Alpha Mapping Project (LAMP) data,,,Another fundamental factor is the presence of available mineral resources for construction and technological equipment, i.e., ISRU. These include iron and titanium oxidesThe aim of this work is to evaluate and compare potential base sites and find an ideal location for a first exploration mission for a future lunar base in which a safe landing area, solar illumination, and access to permanently shadowed areas are present all together. This will further constrain the value of each crater within the lunar South Pole and further our appreciation of the region in general. In this way, a basic framework for future missions is provided.,3 water detections is taken from the MoonTrek website.a.The LROC Wide Angle Camera (WAC) Mosaic at 100 m/pixelb.The shapefile layer of the LOLA for the PSRs,c.3) , as constrained by the Chandrayaan-1’s Moon Mineralogy Mapper  abundance at 100 m/pixel , as derie.The colorized LOLA slope map at 16 m/pixel resolution,f.,,Kaguya data combined with LOLA data also gave important indications about the illumination conditions in the South Pole Aitken (SPA) basinBuilding on the landing site characterization criteria introduced in the previous section,3 infrared spectra, detected the possible presence of water ice exposed on the surface of the lunar south polar region. Another study identified 169 PSRs distributed on 8 craters  located both on the near side (98 PSRs) and on the far side (71 PSRs) of the Moon within 6° of latitude from the South Pole with a total of 820 points of water ice detections.We studied how the compared sites were proximal to PSRs see  and to t5FeSi by aluminothermic reduction at 980°C for 4 h with chemical components of 79.71 mass% aluminum, 12.03 mass% silicon, 5.91 mass% iron, and 2.35 mass% titanium.The presence of variable resources within the regolith Ideally, the base site would receive permanent sunlight, but no such areas are on the Moon.The visibility of Earth is important for a constant communications link between the base and the home planet, although more important is the direct line of sight to the network of communication such as the Deep Space Network. At a minimum, at least a fraction of Earth’s disk should be visible from the given location on the Moon.2) and stays level with or is at most 0.3 km higher than Henson’s slightly more rugged floor . The site of interest for the eventual lunar base is a square ∼4.5 × 4.5 km located on the north-eastern side of the Sverdrup-Henson crater at the border between the PSR and the partially illuminated zone  in its north-western parts. The remaining floor has an area of ∼76 km2.De Gerlache is, more or less, the same size as Sverdrup  but has a more rugged floor. This is largely due to the presence of a younger impact crater , and inside de Gerlache , all of which have PSRs  than the craters de Gerlache and Shackleton . Howevernavigable or accessible. If the route has short sections with ∼15° slopes, it is deemed potentially navigable, pending better resolution data from eventual ground truth observations from rovers and astronauts. Accessibility and navigable distance are listed in We analyzed the LOLA slope map over the craters Sverdrup-Henson, de Gerlache, Shackleton, and Unnamed Crater at a resolution of 100 m/pixel.The floor of Sverdrup is very flat, generally with <5° local slopes . An easiMost of de Gerlache’s floor slopes are <5°, but 7–10° sections also exist. No navigable paths connect it with the floor of the ∼15.5 km-diameter younger crater. De Gerlache is accessible from the north, on the side opposing the highest peaks, but this path requires driving through or just at the margin of a PSR-specific area. Narrow alternative potential paths just at the 15° limit may connect the floor to the antenna/solar panel installations at the southern rim A, as welGenerally, the circular route at Shackleton crater is < 1 km wide, though some ∼100 m wide parts may be deemed too hazardous to pass. Several accessible routes extend from the rim crest toward craters Henson, Sverdrup, Slater , and one potential path toward de Gerlache. The crater walls are too steep (≥20°) for navigable paths between the rim crest and the PSR within the crater.2 (with slopes <7°) to ∼65 km2 (slopes <15°). Additionally, a single ∼45 km long, and only possibly traversable route with short sections just above the 15° limit, leads from the top along the ridge’s western extension to the surrounding intercrater plains. From there, the closest accessible PSR and some water detection points are at least 10 km away  Special Action Team document.,The Sverdrup-de Gerlache region has been designated as a target of interest for the Artemis III mission.Other lunar missions will also be advantageous for eventual settlement objectives and missions. While future National Aeronautics and Space Administration (NASA) Commercial Lunar Payload Services (CLPS), like Peregrine and Blue Ghost, and other international missions, such as the Korea Pathfinder Lunar Orbiter, are slated to venture to the Moon in the next decade across various locations on the lunar surface, these will also be useful to understanding the regolith properties to use for human settlement and habitat-building, and especially establishing a communications network to eventually be used by multiple astronautic facilities.in situ detection and quantity estimation of water ice (including within PSRs and within the lunar regolith) and mineral resources, which is particularly important for the NASA Artemis program and its planned landing of astronauts at the South Pole in 2024.Confirming orbital observations with ground truth should be a priority task for future landers near the lunar South Pole. The priority task includes in situ lunar polar materials is the Volatiles Investigating Polar Exploration Rover (VIPER) mission,The first mission to investigate and sample A rover similar to VIPER at Sverdrup would provide the means to study this PSR crater and close proximity to other PSR sites, which could lead to further hypotheses of how volatile distribution and chemical processes may differ across various PSRs. Rover operations at Sverdrup also bring some challenges, such as low temperatures, localized steep slopes at the crater walls, and potential boulder obstacles.,−3) electrolytes; such a progress is ascribed to the noncrystallinity of the electrolyte although further measures are needed to improve electrochemical performance at lower temperatures.The concept of a Lunar Volatiles Scout (LVS) drill mounted on a Polar Ice Explorer (PIE) rover, with a total mass <16 kg, able to traverse slopes of 15° (but tested for 20°), and equipped with solar cells providing a maximum of 35 W for charging the Li-batteries and operation supply, including thermal passivization for the survival of the equipment at very low temperature, has been designed to overcome the challenges related to the harsh environment of the PSRs.Thanks to the combined datasets of various missions, a preliminary analysis of a possible settlement site near the South Pole of the Moon is now available. Such a settlement could be built inside Sverdrup-Henson  just downhill from the rim of de Gerlache. Its strategic position, easy access, availability of resources , energy, and the possibility of communications with Earth make Sverdrup-Henson a potentially suitable location for establishing the first settlement at the lunar South Pole. A potential next step would be to investigate the chemical content of the Sverdrup-Henson Unnamed Crater site on the surface and at shallow depths with a lander to verify orbital observations and better assess the actual quantity of water ice present. At last, although the Henson-Sverdrup area is potentially the best place for the first settlement, we will need all the water that we can get from all the sites in case of an extended campaign of colonization of the Moon.It is imperative to understand whether the spectroscopic detections correspond to some amount of a water reservoir realistic for long-term surface operations. Furthermore, we need to test technologies and long-lasting batteries that would allow rovers and other potential mobile units to operate inside the PSRs under extreme cold and reduced illumination.giovanni.leone@uda.cl).Further information and requests for resources and reagents should be directed to and will be fulfilled by the lead contact, Giovanni Leone (This study did not generate new unique reagents.Our study does not use experimental models typical of the life sciences.3 water detections is taken from the MoonTrek website.We conducted a preliminary survey using the datasets listed in the Our study does not materials typical in the life sciences.There is no statistical analysis in this paper.We have no relevant resources.


We report an unusual case in which an unabsorbed bio-absorbable screw in the tibial tunnel of anterior cruciate ligament reconstruction (ACLR) performed 11 years ago caused massive osteolysis and subsequent failure of total knee arthroplasty (TKA). ACLR was performed using suspensory fixation on the femoral side and a bio-absorbable interference screw on the tibial side. Fragmentation of the bio-absorbable screw at the time of tibial component implantation is thought to have evoked an accelerated inflammatory response, causing osteolysis, which finally resulted in early failure of the TKA. The outcome of total knee arthroplasties (TKAs) is excellent, with a 95% survival at 15 years .Graft fixation in ACLR is a weak link, particularly at the tibia, as the tunnel is nearly collinear with the pathway of the graft during extension . An inteWe report a case in which an unabsorbed bio-absorbable screw used for ACLR 11 years ago led to massive osteolysis, loosening of the tibial component and ultimately TKA revision.A 54-year-old male underwent TKA for arthritis after previous ACLR. ACLR was done 11 years ago, using suspensory fixation and a bio-absorbable screw on the femoral and tibial sides, respectively (Figure A year after surgery, the patient complained of pain and recurrent swelling. Serial radiographs confirmed progressive osteolysis in the region of tibial tunnel, as shown in Figure Intraoperatively, after explantation of the loose tibial component, a large cavity filled with jelly-like mass with a fragmented but unabsorbed bio-absorbable screw was encountered Figure . Fluid aTwenty-two months after surgery, the patient continues to be pain-free with good range of motion.There have been reports on the higher risk of reoperation after TKA in patients with prior ACLR ,6,7. ProBio-absorbable screws introduced into clinical practice in the 1980s were immediately followed by recognition of an adverse tissue response that has the characteristics of an inflammatory foreign body reaction ,12. The The absorption of bio-absorbable screws occurs in five stages, during which the screw fragments and these particles are phagocytosed by macrophages releasing by-products ,14. The Bio-absorbable screws, whether composed of a polymer alone or polymer ceramic composites, can cause symptomatic absorption-related intra-osseous tibial tunnel cysts even decades after initial implantation . The delAlthough the exact aetiology is unclear, we hypothesise that the massive osteolysis was caused by the fragmentation of the unabsorbed bio-absorbable screw during the implantation of TKA. This fragmentation evoked an accelerated inflammatory response, leading to osteolysis. The other explanation could be an accelerated inflammatory response due to changes in the surrounding environment of the bio-absorbable screw after TKA.We advocate caution in TKA patients with prior ACLR and recommend further imaging to rule out tunnel osteolysis. If present, the pathology should be managed by a stemmed tibial component to bypass the defect, which should be curetted and filled with either cement or bone graft, depending upon the size.


Melosira arcticaand ambient sea water from three locations in the Fram Strait toassess their microplastic content and potential as a temporary sinkand pathway to the deep seafloor. Analysis by μ-Raman and fluorescencemicroscopy detected microplastics (≥2.2 μm) in all samplesat concentrations ranging from 1.3 to 5.7 × 104 microplastics(MP) m–3 in ice algae and from 1.4 to 4.5 ×103 MP m–3 in sea water, indicating magnitudehigher concentrations in algae. On average, 94% of the total microplasticparticles were identified as 10 μm or smaller in size and comprised16 polymer types without a clear dominance. The high concentrationsof microplastics found in our pilot study suggest thatM. arctica could trap microplastics from meltingice and ambient sea water. The algae appear to be a temporary sinkand could act as a key vector to food webs near the sea surface andon the deep seafloor, to which its fast-sinking aggregates could facilitatean important mechanism of transport.Plastic pollutionhas become ubiquitous with very highquantitiesdetected even in ecosystems as remote as Arctic sea ice and deep-seasediments. Ice algae growing underneath sea ice are released uponmelting and can form fast-sinking aggregates. In this pilot study,we sampled and analyzed the ice algae Thisstudy shows high microplastic concentrations in Arcticice algae relative to ambient sea water, indicating that it couldbe a temporary sink and vector to ice-associated and benthic foodwebs. Particles ≤5 mm are termed microplastics (MPs) andconsidered irretrievable.3 Despite theremoteness of the Arctic, MPs have become particularly abundant andubiquitous in Nordic ecosystems,5 including Arctic snow,glaciers, sea water, and very high concentrations in deep-sea sedimentsand sea ice.10 Not surprisingly, MPs were also reported in organisms associatedwith sea ice such as sympagic zooplankton11 and polar cod (Boreogadus saida).13Sincethe 1970s, plastic production hasincreased annually by 8%and could double in the coming 20 years.Melosira arctica , M. arctica aggregates that were free-floating amongthe sea ice  during a sampling campaign for MPs in snow, melt ponds,sea water, and sea ice and had to be safe for landing. Here, we presentonly the results from  sea ice 1A,B were sea ice 1.7 (40 mLof H2O2 was placed over the filtered samplesheld in borosilicate glass filtration equipment and incubated at roomtemperature for 48 h and then flushed with 200 mL of MilliQ). Then,the air-dried filter was stored in sealed metal containers until analysis.In a dedicated MP laboratory, M. arctica samples were subsampled for MP and nanoplastic (NP) analysis ina laminar flow fume hood that had been pre-cleaned to minimize contamination.Using sterilized stainless-steel tweezers and sterilized stainless-steelmicro spatulas, subsamples of 3–7 g of wet material (see Supplementary Data) were placed into sterilizedborosilicate glass test tubes (four subsamples per site). 20 mL of30% w/w hydrogen peroxide  was added to each samplewith sterilized aluminum foil lids, and then, the samples were placedin a dry heat block for 48 h at 50 °C. An additional 10 mL ofH2O2 was then added, and the samples were returnedto the dry heat block for another 48 h at 50 °C. The sampleswere then filtered onto 47 mm diameter aluminum oxide filters (0.2μm porosity) and flushed with 250 mL of MilliQ for Raman analysis.Filters did not become blind during any of the collection or filtrationprocesses. The filters were stored in sterilized 50 mm diameter aluminumcontainers to minimize contamination.Back on the researchvessel, icealgal samples were transferred into triple MilliQ-rinsed glass vialsand refrigerated (at 4 °C) until analysis. A subsample was takenfor species identification under the microscope 1C. The s22 and used consistently by Allen et al.25 (Horiba Xplora Plus) using a 785 nm laser , 1200 gr mm–1 grating, 50 μm slit,and 25% power (filter), with spectra collected over 200–2000cm–1 Raman shift using five acquisitions of 10 s.25% of each filter was assessed following the filter area representationof Huppertsberg and Knepper.26 Raman spectrawere analyzed using Spectragryph,27 SloPP,SloPP-E,28 and siMPle29 Raman reference libraries supplemented with in-house plasticspectra references. Spectra with a ≥80% hit rate were countedas plastic particles and included in the total sample MP count.33 The limit of quantification  for this analysis was set to 1.2 μm for M. arctica samples and 2.2 μm for sea watersamples. This was due to the different porosity of filtration possiblefor the two different matrices. The μ-Raman results were usedto quantify the number of MP particles and the quantity of differentplastic polymer types in each sample according to Armbruster and Pry34 and Dawson et al.,35 where LOQ ≥ LOD (Limit of Detection) and LOD = (meanblank + 1.645 (SDblank)) + 1.645 (SDlowest sample result).All samples were then analyzed by μ-Ramanmicroscopy following published protocols developed by Zhao et al.38 to provide a particlecount check and the particle shape and size representative of eachsample. Particles were identified as fibers (1:3 width-to-length ratio)40 or fragments due to the uncertainty in defining films. Samples werestained with Nile Red powder (Sigma Aldrich) dissolved in methanol to result in 0.1 μg mL–1 solution and pre-filtered through sterilized glass fiber filters.37 The Nile Red solution was stored in a sterilized, sealed glass containercovered in aluminum foil in the dark at 4 °C. Stained sampleswere oven-dried (30 °C) overnight and then placed in the fridge(4 °C) in sealed aluminum containers to rest prior to fluorescencemicroscopy imaging. A Nikon LV100ND fluorescence microscope with anFITC (Fluorescein) filter was used to image 25% of each filter followingthe filter area representation.26 Fluorescentparticle dimensions (including circularity and the ferret diameter)and counts were collected using FIJI software41 following published standards.42 Nile Red fluorescenceMP counts were used to confirm the Raman MP quantification and toobtain particle size and shape information.Samples were secondarily analyzedusing Nile Red fluorescence microscopySample preparation was undertakenin a dedicated MP laboratory withcontrolled access, a dedicated HEPA filter, and a laminar flow fumehood. Prior to sample preparation, the laboratory and laboratory fumehood were pre-cleaned to minimize laboratory contamination. Pre-cleaningwas completed using a plastic-free cleaning fluid followed by MilliQwater and clean 100% cotton lint-free clothes. Only cotton clothingand cotton lab coats were worn in the laboratory, nitrile gloves wereused for all chemical handling, and all materials were sterilized(superheated to 450 °C) or triple-washed with MilliQ (as appropriate)between each use.Supplementary Information). It is acknowledgedthat spiked recovery samples should ideally include a range of polymertypes, and future studies will incorporate this advancement.Field blank samples underwent the sample digestionprocess and full analytical process, resulting in all field blanksbeing full process blanks. All samples were blank-corrected usingthese field blank μ-Raman results. Blanks had on average 5 (±2) particles per sampled filter area . Positive controls (laboratory blanks spikedwith known plastic particles) were also created to check the fullprocess recovery efficiency. A spiked solution was made from polyethyleneparticles ranging from 2 to 110 μm (particle size distributiondescribed using a Mastersizer 2000), and spiked solution samples underwentthe full preparation and analysis process as field samples and fieldblanks. The μ-Raman analytical efficiency was calculated to be 89% (± 12%) and the Nile Red fluorescencemicroscopy analysis efficiency to be 86% (± 12%) (see the https://worldview.earthdata.nasa.gov/). After the floes reachedthe closed ice cover at ∼82°N, tracking was continuedusing an automated backtracking algorithm based on passive microwavedata. Note that the automated tracking is less accurate in the FramStrait,43 which is why we have limitedits use to the central Arctic. The applied automated backtrackingalgorithm, products, and their accuracy are described in Krumpen etal.44 Tracking was discontinued if theice concentration at a specific location along the backward trajectorydropped below 20% and we assumed the ice to be formed.Thepossible origin and pathways of the ice algal samples were determinedusing two different satellite-based tracking approaches: in the FramStrait, floe locations were tracked visually using optical satellitedata. Visual identification and tracking were carried out using NASA’sinteractive interface to display full-resolution satellite imageson a daily basis  and the polymer type .Blank correction of all samples was undertaken using the full processfield blank sample results to ensure that all field and laboratoryactions were accounted for in contamination assessment and the mostconservative approach to blank correction was used. Simple correlationand statistical tests were completed using Excel. The underlying dataand test results are available in the Supplementary Information.Nile Red fluorescence microscopy analysiswas undertaken using FIJI(ImageJ)Supplementary Information). M. arctica samples contained 5–66MP particles per mg wet weight . While sea ice inthis region contained higher MP levels (1.2 × 107–1.1× 106 MP m–3),7 sea ice concentrates suspended organic carbon by two ordersof magnitude relative to ambient sea water during ice formation througha process termed “scavenging”, which partly explainsthe exceptionally high MP concentrations .45 If two orders ofmagnitude are deducted from the MP concentrations for a better comparison,the MP concentrations of sea ice and ice algae become strikingly similarat the magnitude scale despite differences in the methodology used.MP concentrations in water samples ranged from 4.5 to 1.4 × 103 MP m–3 with an overall mean of 2.8 ±1.3 × 103 MP m–3.MP particleswere found in allsubsamples across a variety of polymertypes and particle sizes. A total of 400 MP particles were identifiedfrom the 12 subsamples   with significantlyhighest levels found in the easternmost sample Mel_1 (5.7 ± 1.7× 104 MP m–3), followed by the westernmostMel_3 (2.2 × 104 ± 8.1 × 103 MPm–3) and nearby Mel_2  followed by Mel_3(2.5 × 103 ± 2.8 × 102 MP m–3) and Mel_2  = −3.75, p = 0.006 for total sea water MP; t(9) = 4.046, p = 0.003 for sea water MP <25 μm). This could be interpreted as an indication of M. arctica trapping MPs from the surrounding seaand melt water during ice drift  and volume  were higher than previous measurements from the Fram Strait (0–1287MP m–3),9 which is likelydue to differences in the methodology used . Constraining the sea water sample results tothe particle size limit,9 our mean seawater samples for particles >25 μm (527 ± 294 MP m–3) are comparable to those previously published (421MP m–3).Since the ice berg (Mel_2) could not be locatedon high-resolutionsatellite data, suggesting that the source was unknown or that itdrifted with the sea ice floes (Mel_1), it was combined with the latter’sdrift trajectory 3. The pa21 presented a greater quantityof smaller MP particles (69% <5 μm), while the more easternsamples contained a slightly larger proportion of >5 μm particles(59–60%).MP particles in both algal and seawater samples were generallysmaller than 40 μm, with on average 94% (88–97%) of thetotal MP particles identified as 10 μm or smaller in size 4. SampleM. arctica cellsize rangesfrom 20 to 30 μm.20 Thus, these small MPparticles could have been entangled in the filamentous threads, e.g.,“stuck” to the outside of the algal aggregates, a processthat could be helped by the mucous extracellular polymeric polysaccharidesproduced by the algae.46 Suspended MPs were also observedto adhere to the sticky surface of the seaweed Fucusvesiculosus in experiments.47 NP also adhered to green algae due to electrostatic attraction betweenNP and cellulose.48 What is more, adsorbedNP hindered algal photosynthesis in experiments, possibly by attenuatinglight,48 a process that has been reportedfor several algal species.49 Small MPscould also have occurred within the M. arctica cells. While differentiation was beyond the scope of this pilotstudy, it has been suggested that small MP particles could damageand enter algal cells, leading to oxidative stress responses includingthe damage of chloroplasts and thus inhibition of photosynthesis dependingon the experimental doses used.49 Bothmechanisms could have serious implications in terms of carbon sequestrationand the ocean’s capacity to mitigate climate change, especiallyas MP concentrations are set to increase at the very least due tofragmentation of plastic debris that is already in the ocean.3The M. arctica could be entrainingthese smaller MP particles from the surrounding sea water and themelting sea ice. Sea ice is reported to contain MP particles up to50 μm with a notable percentage of particles sized 11–25μm,7 a larger range of particle sizesand a greater quantity of slightly larger particles than those foundin the M. arctica samples. Similarly,snow and Arctic sea water are reported to present a larger MP rangeand particle size (up to 450 μm in snow and ≤200 μmin sea water).9The occurrence and particle size distributionof these small MPssuggest that 4 PET accountedfor the highest proportion of particles overall (13%). Polymers commonlyused in paints and building/construction materials  formed the second and third highest proportionsof the particles , concurring with elevatedpaint-related particles found in Arctic snow and water samples.9 Polyester (PES), polyethylene (PE), and polyamide (PA) were alsonotable in all samples . Polyesterand polyamide have been reported in Arctic sea water in high quantities(up to 39%).50 Similarly,polyvinyl chloride (PVC) was also reported in deep-sea sediments (1–13%),51 sea water (<30%),50 and sea ice (2–5%)50 from the Arctic. Thereis also an atmospheric component to the Arctic MP cycle,52 and atmospheric MPs are knownto comprise a wide range of polymer types that can be rapidly transportedover vast distances helped by resuspension of MPs from the sea surface.53 Both the polymer composition and the particle size distributionfound in the M. arctica samples indicatethat atmospheric deposition could play a role along with sea watertransported into and out from the Arctic and from sea ice and snowmelt.Despite the smallsample size, the MP particles comprised 16 differentpolymer types without a clear dominance of any single polymer type4. SimilaM. arctica is a primary producer that colonizes the underside of Arctic seaice, growing during the summer periods when photosynthesis is possibledue to available sunlight and nutrients.54 As the sea ice melts, the detached M. arctica is released into the water, where it produces high amounts of extracellularpolymeric substances and forms aggregates.55 Such aggregates can stay afloat if irradiance promotes photosynthesis,and the resulting oxygen bubbles are captured in the viscous aggregates.55 During the next freeze-up, this could seed thenew-forming ice and form the basis of new M. arctica colonies,15 a process that could alsoinoculate new-forming ice with MPs.M. arctica aggregates sinksto the Arctic seafloor, which accounted for 85% of the vertical carbonexport in the Arctic in 2012.16 Katleinet al.15 suggested that aggregates witha diameter of 3 cm can reach the deep seafloor within a timeframeas short as 1 day. Bergmann et al.5 suggestedthat MPs bound to ice algal aggregates could contribute to the verticalexport of MPs from the sea surface to the seafloor since concentrationsof 6.3 × 106 MP m–3 were measuredin the deep-sea sediments beneath the marginal ice zone and a positivecorrelation with the chlorophyll a content was found.9However, an important fractionof the 56 and break up increasinglybecause of the increased storm frequency, potentially supporting greaterice algal blooms due to higher light availability. However, this islikely offset by nutrient limitation and the shorter frozen periods,with the ice habitat melting earlier and freezing up later than inpast decades, resulting in shorter algal growth periods57 as well as lower biomass and deposition. If M. arctica is a key transport vector of MPs fromthe sea surface to the seafloor, then any shift in M. arctica growth and circulation will also modifythe transport and distribution of MPs. However, other phytoplanktonspecies, such as Phaeocystis pouchetii, which can form extensive floating gelatinous colonies in Arcticwaters that also produce sticky exopolymer particles58 and sink to the seafloor,59 couldplay this role.Following the current trend in climatechange, resulting in hottertemperatures and more extreme weather events, sea ice will becomethinner and less abundant60 they could be a vector into under-icefood webs. Indeed, MPs were recently detected in grazing zooplanktonfrom the Fram Strait.11 Similarly, it couldpave the uptake of MPs by benthic organisms that have been observedto feed on ice algae deposited on the seafloor.61 While the effect of this uptake on Arctic species and ecosystemsis not yet known,5 Arctic biota are alreadyunder serious pressure from global heating, which progresses fourtimes faster in the Arctic compared with the globe.62 Plastic pollution likely exacerbates this pressure, soit needs to be tackled efficiently.63No matter what the consequences, it could bespeculated that MPsfrom melting sea ice could be trapped by Arctic ice algae as a resultof its filamentous and sticky morphology. Since ice algae are hotspotsof biological activity and an important food source for grazing organisms,