EpiSurf is a Web application for selecting viral populations of interest and thenanalyzing how their amino acid changes are distributed along epitopes. Viral sequences aresearched within ViruSurf, which stores curated metadata and amino acid changes importedfrom the most widely used deposition sources for viral databases  and Global initiative on sharing all influenza data (GISAID)).Epitopes are searched within the open source Immune Epitope Database or directly proposedby users by indicating their start and stop positions in the context of a given viralprotein. Amino acid changes of selected populations are joined with epitopes of interest;a result table summarizes, for each epitope, statistics about the overlapping amino acidchanges and about the sequences carrying such alterations. The results may also beinspected by the VirusViz Web application; epitope regions are highlighted within thegiven viral protein, and changes can be comparatively inspected. For sequences mutatedwithin the epitope, we also offer a complete view of the distribution of amino acidchanges, optionally grouped by the location, collection date or lineage. Thanks to thesefunctionalities, EpiSurf supports the user-friendly testing of epitope conservancy withinselected populations of interest, which can be of utmost relevance for designing vaccines,drugs or serological assays. EpiSurf is available at two endpoints.Database URL: http://gmql.eu/episurf/ (for searching GenBank and COG-UK sequences) andhttp://gmql.eu/episurf_gisaid/(for GISAID sequences). With the coronavirus disease 2019 (COVID-19) pandemic outbreak, unprecedented efforts havebeen dedicated to the sampling and sequencing of the severe acute respiratory syndromecoronavirus 2 (SARS-CoV-2), with the objective of capturing and then studying SARS-CoV-2variations and their effects. Leveraging on our previous experience on humangenomics-targeted computational systems , a dataEpitopes are strings of amino acid residues from a pathogen’s protein that can berecognized by antibodies or B/T cell receptors, thus activating an immune response from thehost; in particular, epitopes available for the Spike protein of SARS-CoV-2 are used in thedesign of COVID-19 vaccines. For epitope-based vaccine design, it is important to studytheir conservation; conversely, observing epitope variability has applications in diseasemonitoring, diagnostic settings and drug design. We adopt the most basic conservancy measurefor an epitope (i.e. a region on a protein), based on the number of changed amino acidresidues with respect to the reference sequence of the virus species in the same positionrange. ‘Conserved’ epitopes have a zero distance from the reference, whereas ‘modified’epitopes exhibit at least one amino acid change.To date, the most relevant resource for epitopes employed by the research community is theImmune Epitope Database (IEDB) . It encoEpiSurf supports the search of viral sequences deposited on public platforms—released dayby day on GenBank, COG-UK and GISAID and then integrated within the ViruSurf platform;relevant sequences can be extracted, thanks to a rich set of metadata information, includingthe sampling location, collection and deposition date, sequence’s lineages and strains, andsubmission laboratory. On top of this, EpiSurf provides several methods to intersectselected sequences and selected epitopes, thereby integrating information about amino acidchanges and epitopes extracted from the largest and most popular data collections in theworld using their metadata. Lastly, the integration with the VirusViz tool allowsinformative visualization of sequence variation in the specific epitopes’ locations.Building up on our previously developed resources, EpiSurf offers a novel, fullyindependent, integrated environment for evaluating conservancy of epitopes againstarbitrarily extracted viral populations, reflecting the spreading of viruses in time andspace and their genetic evolution.http://tools.iedb.org/main/).Several tools for epitope prediction have been studied in the past . The moset al. (For the specific case of SARS-CoV-2 (and closely related viruses), we report the following.COVIEdb  targets et al. ].Similaet al. , adatabet al.  and Coroet al. . COVID met al.  and COVIet al.  provide http://tools.iedb.org/main/analysis-tools/), used for a variety of detailedanalyses. Among these, EpiSurf is similar in spirit to the Epitope Conservancy Analysis(ECA) tool  tool ; howeverCOVIDep  is an inThe Virus Pathogen Database and Analysis Resource (ViPR)  is anothThe COG-UK Mutation Explorer (COG-UK-ME) recentlyhttp://gmql.eu/virusviz/), a Web application for visualizing and exploring thefully open source nucleotide and amino acid changes that are made available through searchservices or autonomously provided as input from users. When VirusViz is opened starting froman EpiSurf search, the tool visualizes a bar plot where the x-axisrepresents the amino acid positions of a protein, bars’ heights represent the number ofsequences in the selected populations that feature a change in the bar’s position andepitope position ranges are represented as blue vertical regions , anintegrated database of SARS-CoV-2 sequences (and of other similar viruses), storing allthe sequences deposited to GenBank (http://gmql.eu/virusurf_gisaid/)stores relevant metadata and variation information of GISAID sequences , technological metadata (EXPERIMENTTYPE) andorganizational metadata (SEQUENCINGPROJECT). The ‘analytical perspective’ provides theANNOTATION, AMINOACIDVARIANT, NUCLEOTIDEVARIANT and VARIANTIMPACT tables.https://github.com/DEIB-GECO/EpiSurf/wiki/Database-and-sources, pointing toSchemaSpy (http://schemaspy.org/) documents. In thefollowing, we only detail the additions that were not present in  or discontinuous  epitopes, composed ofamino acid residues that may be located in different protein regions—brought togetherby protein folding. We also report information on the experiments performed toretrieve the epitope. Each epitope record in EpiSurf may correspond to multiplerecords from IEDB . Therefore, thefollowing four fields can take multiple values:The EPITOPE table, describing the epitopes extracted from IEDB, connected both toHOSTSPECIES and to the VIRUS table. The core information is contained within the‘epitope sequence’‘assay’ indicates the target of the experiment [allowing values ];‘assay_type’ indicates the outcome—considering possibly multiple experiments ;‘hla_restriction’  indicates the list of theclass (e.g. ‘HLA Class I’) or lists of alleles to which the epitope is restricted—this is relevant only for T cell and MHC ligandassays;‘mhc_class’ indicates the general classes of alleles provided in the previousfield .R) divided by the totalnumber of those tested (N), summed up by mapped epitopes; however, tocompensate for epitopes that are identified by a low number of assays, we employ acorrected formula , [769–786] and809–826] on Spike and [153–170] on N. These may be checked, for instance, against theEpiSurf sequence population from the USA, of about 205 000 sequences as of 9 May 2021.6 on SpikWe then focus on N4P5 [reported in  as themet al. . From the Allele Frequency Net Database web portal , we gathIn the last months of 2020, there has been interest in studying seven independentlineages circulating in the USA all having a change in the Glutamine (Q) amino acid atposition 677 of the Spike protein. These all seemed to have originated and spread in thelast few months . Q at 67et al. . We also select only complete sequences to ensure the accuracyof the variation calling algorithm, thus retrieving a total of 1665 sequences. By usingMode 1 of EpiSurf (Custom Epitopes), we then build the target epitope on the E proteinwith the range 346–360. As a result, we observe that 64 of the sequences exhibit at leastone mutation (‘MUT FREQ’ of 1.06), representing the 3.84% of the total set (‘MUT SEQRATIO’).The conservation of the epitope can be checked against EpiSurf sequences. We restrict oursearch to Dengue Virus 1 sequences deposited in the GenBank that were collected from humanhosts before October 2017  and could thus be further investigated.Chen  During 2020 and the beginning of 2021, fueled by the outbreak of the COVID-19 pandemics,huge interest has been focused on studying epitopes, parts of the SARS-CoV-2 sequence thatcan be recognized by vaccines, drugs and serological tests. For epitopes, IEDB is recognizedas the most important, fully public repository, as of today collecting about 5000 epitopesof SARS-CoV-2 , well-described by means of attributes andsearch panels.Several computational tools are used for supporting the prediction of epitopes. Our EpiSurfsystem covers a different need, as it provides a flexible interface for testing theirconservancy, measured as the presence/absence of amino acid changes over epitope sequences.The unique aspect of EpiSurf is the ability to perform such conservancy testing byintersecting epitopes of interest, extracted by means of queries in the IEDB, against theamino acid changes that are present in arbitrarily selected viral sequences, e.g. bylineage, location or time of sequence collection. Such queries upon viral sequences can alsobe used against custom epitopes, freely entered by EpiSurf users.Extensive analytical and visual support is offered to the users, including aggregations bymetadata, statistics of mutated sequences and distribution plots (through our connection toVirusViz). EpiSurf aims to be a solid companion tool for researchers designing epitopes thatneed to rely on the big corpus of sequences available online.


The treatment strategies for rotator cuff tears have grown more sophisticated in recent years. Over the past decade, arthroscopic superior capsular reconstruction (SCR) has become popular for treating irreparable rotator cuff tears. Despite the popularity, the literature on the clinical outcomes of SCR is limited. Several surgical procedures using variable graft materials and different techniques have been proposed promising early clinical results with improvements in shoulder pain, range of motion, and overall function. In this paper, we present a case of bilateral massive irreparable rotator cuff tears, with a full description of our surgical technique and the successful outcome of our management. Management techniques and algorithms for rotator cuff tears have grown more sophisticated in recent years . AlthougThis gentleman was a 50-year-old right-hand dominant self-employed driver who presented with a chief complaint of bilateral anterolateral shoulder pain which began subacutely and had persisted for over a year. It woke him up from sleep, and he had failed non-operative treatment, including physiotherapy. He was healthy otherwise and specifically was pre-diabetic (diet controlled) but a non-smoker. The clinical exam was notable for pseudoparalysis but good passive range of motion, albeit with subacromial crepitus and positive impingement signs. There was no tenderness of the AC joint but a positive Yergason’s sign for proximal LHB irritability. Significant weakness was noted when testing supraspinatus and infraspinatus. Subscapularis was tested as normal power. X-rays confirmed significant proximal migration of the humerus but no significant osteoarthritic changes. An MRI showed some long head of biceps (LHB) edema and massive supra and infraspinatus tear with significant atrophy of the involved muscles with moderate fatty degeneration Figure . Given tSurgery was performed on the right side first, followed by the left side 10 months later. At the time of both procedures, found the articular surface to have only grade 2 changes, and the LHB was found to be tendinopathic with some subluxation and had a concomitant LHB tenotomy. The subscapularis was found to be intact, and the supraspinatus and infraspinatus were both irreparably torn despite attempted soft tissue releases. After decompression, the planned arthroscopic superior capsular reconstruction was performed with three glenoid anchors, a lateral knotless double row, and a posterior margin convergence. Post-operative rehabilitation followed a standardized protocol, with 8 weeks in a sling before an active range of motion and 16 weeks before any light resisted exercises. There were no peri-operative complications after either procedure. The latest follow-up was four years and seven months after the right SCR and three years and nine months after the left SCR. He noted almost complete pain relief in both shoulders and restored active forward elevation and external rotation near full. He had returned to unrestricted activities of daily living as well as his normal occupation as a driver. Surgical technique The surgical technique for arthroscopic superior capsular reconstruction followed a defined set of steps. Procedures were done with the patient positioned on a beach chair. At the same time, the arm is held securely and safely using a supporting arm device that allows the arm to be moved in any direction during the procedure, under general anesthetic, and after an interscalene block. We started the diagnostic arthroscopy while keeping the pump pressure low  and maintaining meticulous hemostasis with bipolar electrocautery throughout. The initial anterior working portal was kept high to aid in graft management later in the subacromial space. Once intra-articular pathology was assessed and treated, we moved to the subacromial space and localized our lateral portal more posteriorly than the usual “50-yard line” to keep more working room for the large anterolateral portal later. After an acromioplasty as necessary, while preserving the coracoacromial ligament, if possible, we moved to this posterolateral portal as the main viewing portal.  Releases around the rotator cuff are then performed to confirm irreparability, including anterior and posterior slides. Once the need for an SCR has been confirmed, bone preparation on the superior glenoid and proximal humeral footprint is accomplished with a combination of ring curettes, rasps, and shavers. Small marrow venting holes on the proximal humerus are also now created. A spinal needle then localizes the glenoid anchors (Arthrex 3 mm BioComposite suture anchors). We often used three anchors (Anterior to clavicle/Neviaser (Supraspinatus Fossa)/Posterior to acromion). The medial row humeral anchors  are also localized by spinal needle just off the acromial border. Graft sizing is critical and is done by positioning the arm in about 40 degrees of abduction, neutral rotation, and with minimal traction applied. Measurements for the graft size are made between all the anchors and marked on the graft, leaving a 10 mm border medially, anteriorly, posteriorly, and a 15 mm border laterally. A bone block and metal ruler as a stiff edge aids in cutting the graft, and medially the corners are beveled slightly to aid in graft insertion. We then punch lateral holes in the graft with a previously used SwiveLock driver to aid in sliding the thicker tap sutures laterally. Graft insertion is then accomplished by turning the pump back on and establish a view again from the posterolateral portal. A sterile towel is placed over the lateral arm to allow the graft to rest without sliding or touching the skin flora. The sutures are then sequentially retrieved from the joint out the anterolateral portal and shuttled through the graft, starting with the lower Fiber Tape and Tiger Tape sutures from the humeral anchors through their punched holes. The individual Suture tape limbs from the glenoid anchors passed with a Scorpion needle. The graft is then folded medially and held with a grasper, and introduced into the joint through the anterolateral portal. The assistants maintain gentle tension and remove slack from the passed sutures. At this point, the glenoid sutures are parked sequentially in their respective portals of insertion, and the humeral sutures are parked in the anterior and posterior portals, respectively. The anterolateral portal is then free for knot tying on the glenoid side. If available, these tails are kept long for later incorporation of any residual stump of native rotator cuff tissue; otherwise, they are cut now. Lateral fixation proceeds with a standard double row knotless suture bridge technique, incorporating anterior and posterior dog-ear prophylaxis stitches. Finally, the posterior margin convergence between the native capsule and rotator cuff tissue and the graft is performed with a Scorpion and individually tied sutures. If any anterolateral rotator interval or transverse humeral ligament tissue is available, then anterior margin convergence to add to graft fixation is performed Figure .Postoperative rehabilitation is guided by a standardized protocol that includes four phases. The first phase (0-4 weeks) is the protection phase, during which patients are advised to keep the upper arm and elbow close to their side using a sling. Neck, elbow, wrist, and hand exercises are encouraged. The phase of controlled motion (second phase) is then initiated and lasts eight weeks. Patients are allowed to begin the closed chain pendulum exercise and shoulder passive range of motion either manually or with the help of a therapist. The third phase (8-16 weeks) is the progressive motion phase in which patients are allowed to start closed chain active-assisted range of motion and isometric strengthening exercises. Finally, the strengthening phase(> 16 weeks) is started, during which the patients are encouraged to build muscle strength and endurance through resistive strengthening and stretching exercises. Currently, the existing ideal indication for SCR is a patient with unbearable discomfort and/or intolerable dysfunction who has undergone unsuccessful non-surgical treatment and presents with massive and irreparable rotator cuff tears with minimal arthropathy, an intact or repairable tendon of the subscapularis, and an efficient deltoid muscle . AdditioTheoretically, this surgical technique works by giving the shoulder joint an inactive restraint to excessive translation of the humeral head, thus improving the force couples of the defective rotator cuff . In addiDespite the popularity of SCR, the literature on the clinical outcomes of the procedure is limited . RecentlIn our case, the patient had fully recovered from the procedure and returned to work without any restriction or complaint of either shoulder. We believe that performing bilateral SCR is a safe and reliable treatment option for young patients with bilateral irreparable massive rotator cuff tears. It provides a promising and excellent joint preserving treatment alternative with lower postoperative restriction than reverse shoulder arthroplasty.


Two-dimensional shear wave elastography (2D-SWE) is a powerful technique that can non-invasively measure liver stiffness to assess hepatic fibrosis.This study aimed to identify the effects of confounding factors, including anesthesia, breathing, and scanning approach, on liver stiffness when performing 2D-SWE in dogs.2O), and forced-inspiration , and liver stiffness was compared among these phases. Changes in liver stiffness were compared between intercostal and subcostal approaches according to breathing phases.Nine healthy Beagle dogs were included in this study. Hepatic 2D-SWE was performed, and liver stiffness was compared between conscious and anesthetized states, free-breathing and breath-holding conditions, and intercostal and subcostal approaches. For the anesthetized state, the breath-holding condition was subdivided into seven phases, which included forced-expiration (5 and 10 mL/kg), end-expiration , which was associated with significantly higher liver stiffness (p < 0.05). Liver stiffness was significantly higher in the subcostal approach than in the intercostal approach (p < 0.05). Changes in liver stiffness were significantly higher in the subcostal approach than in the intercostal approach in all forced-inspiratory phases (p < 0.05).No significant difference was observed in liver stiffness between the conscious and anesthetized states or between the free-breathing and breath-holding conditions. No significant difference was noted in liver stiffness among the breathing phases, except for forced-inspiration with high airway pressure (15 and 20 cm HIn conclusion, when performing 2D-SWE in dogs, liver stiffness is unaffected by anesthesia and free-breathing. To avoid inadvertent increases in liver stiffness, the deep inspiratory phase and subcostal approach are not recommended. Thus, liver stiffness should be interpreted considering these confounding factors. Hepatic fibrosis, which often occurs as a consequence of chronic hepatitis, is a relatively common finding that affects 12% of dogs. For a definitive diagnosis of hepatic fibrosis in dogs, liver biopsy is warranted for histopathologic examination .US elastography enables the quantitative measurement of liver stiffness based on deformation induced by forces exerted on a tissue . Based oWhen performing 2D-SWE, liver stiffness does not solely reflect hepatic fibrosis, as multiple confounding factors can artifactually increase liver stiffness. Accordingly, it is crucial to consider all potential confounding factors that may affect liver stiffness. Common confounding factors in human elastography include the probe, scanning approach, region of interest (ROI), liver lobe, positioning, fasting, anesthesia, and breathing , 7, 9. AAnesthesia or sedation is administered to young children or dogs with low compliance to reduce unintended movements, which cause invalid measurements of liver stiffness , 11. In Scanning approach, including intercostal and subcostal approaches, is another confounding factor that can affect liver stiffness . VariousTherefore, this study aimed to evaluate the effects of confounding factors on liver stiffness by investigating the impact of anesthesia, breathing, and scanning approach when performing 2D-SWE in dogs.Nine intact male Beagle dogs with a mean age of 1.9 years  and a mean weight of 10.0 kg  were used in this experimental study. All dogs were confirmed to be clinically healthy based on physical examination, a complete blood panel including hematocrit and blood chemistry, radiography, abdominal ultrasonography, and echocardiography. The decision to include or exclude the dogs was determined by a veterinarian with 2 years of experience in veterinary imaging. The study procedures were approved by the Institutional Animal Care and Use Committee of Konkuk University .via a conversion formula using shear wave velocity (m/s).Prior to the examination, the dogs were fasted for at least 12 h. Conventional B-mode ultrasonography and 2D-SWE were performed using an ultrasound scanner  and a 3.8-14.0 MHz linear-array transducer . The right lobe of the liver was selected as the target region for examination. After clipping the target region and applying a sufficient amount of ultrasonographic gel, B-mode US images of the liver were acquired with minimal compression of the probe. In the B-mode images, the intrusion depth was 5 cm and a rectangular 1 ×1 cm field of view (FOV) was set at a minimum of 10 mm below the liver capsule to avoid possible reverberation artifacts. A multi-shot mode of 2D-SWE, which emits continuous push pulses from the probe and enables the selection of a single image, was performed. Within the selected image, a round ROI with a 6-mm diameter was placed in the FOV while avoiding the diaphragm, large vasculature, and ductal structures. These measurements were repeated with different FOV and ROIs until seven valid measurements were obtained. The mean of the obtained data was presented as Young's modulus (kPa), which was automatically calculated by the installed software via contour lines. Parallel and straight lines with constant intervals were regarded as highly reliable data, while distorted and chaotic lines were considered to indicate unreliable data  and maintained with 2.0% isoflurane  and oxygen (1.0 L/min). Heart rate, blood pressure, oxygen saturation, and end-tidal CO2O), and forced-inspiration  , end-expiration (0 cm H cm H2O) . For for cm H2O) . To prev cm H2O) . Other bTwo different US scanning approaches were used: intercostal and subcostal approaches . For thet-test was performed to assess the significance of differences in liver stiffness between conscious and anesthetized states, free-breathing and breath-holding conditions, and intercostal and subcostal approaches. One-way repeated-measures analysis of variance followed by Bonferroni correction for multiple comparisons were performed to compare liver stiffness among breathing phases. For both scanning approaches, changes in liver stiffness were calculated by subtracting liver stiffness in end-expiration 0 cm H2O from the stiffness in each breathing phase. A p < 0.05 was considered statistically significant.Statistical analysis was conducted with commercially available software  by one veterinarian. All measured data were presented as means and standard deviation (SD). The coefficient of variation (CV) was calculated for all variables by dividing each SD by the mean. A CV of <30% was considered clinically reliable. The normality of the obtained data was confirmed using the Shapiro–Wilk test. For normally distributed data, a paired p = 0.169 for intercostal approach and p = 0.533 for subcostal approach)  .p = 0.119 for intercostal approach and p = 0.190 for subcostal approach) (No significant difference was observed in liver stiffness in the conscious state between free-breathing and breath-holding conditions for both scanning approaches (pproach) .2O), and forced-inspiration (5 and 10 cm H2O). Liver stiffness was significantly higher in forced-inspiration 15 cm H2O than in free-breathing, forced-expiration (5 and 10 mL/kg), and end-expiration 0 cm H2O. Further, liver stiffness was significantly higher in forced-inspiration 20 cm H2O than in free-breathing, forced-expiration (5 and 10 mL/kg), end-expiration 0 cm H2O, and forced-inspiration 5 cm H2O. In the subcostal approach, there was no significant difference in liver stiffness among free-breathing, forced-expiration (5 and 10 mL/kg), end-expiration 0 cm H2O and forced-inspiration 5 cm H2O. Liver stiffness was significantly higher in forced-inspiration 10 and 15 cm H2O than in the other breathing phases, except for forced-inspiration 20 cm H2O. Liver stiffness was significantly higher in forced-inspiration 20 cm H2O than in all other breathing phases   .SWE is a robust technique that allows the measurement of liver stiffness and the assessment of hepatic fibrosis in a non-invasive manner . In humaIn young children, transient elastography should be performed in combination with sedation to avoid unintended movements that lead to invalid measurements . In thisIn young children who cannot hold their breath properly, hepatic SWE is often performed during free-breathing. Conflicting results have been reported with regard to differences in liver stiffness between free-breathing and breath-holding conditions. Some studies have reported no significant difference , 16, 17,Liver stiffness was significantly higher in forced-inspiration with high airway pressure than in other breathing phases. Similar to the current findings, liver stiffness measured using magnetic resonance elastography was higher in inspiratory breath-holding than in expiratory breath-holding states , 20, andIn this study, no significant difference was noted in liver stiffness among all expiratory phases and inspiratory phases with low airway pressure. This is in contrast to previous human studies that reported higher liver stiffness in expiration than in normal gentle inspiration , 22. HowLiver stiffness measurements were significantly higher in the subcostal approach than in the intercostal approach. This is contrary to the results of a previous study on Beagle dogs, which reported no significant difference in liver stiffness between intercostal and subcostal approaches . In humaThere was a significant effect of the interaction between scanning approach and breathing phase on liver stiffness. In all inspiratory phases, changes in liver stiffness were significantly higher in the subcostal approach than in the intercostal approach. This suggests that the effect on breathing is greater for the subcostal approach than the intercostal approach. As mentioned above, probe compression artifacts in the subcostal approach may have underpinned the increase in liver stiffness, but this does not fully explain the greater changes in liver stiffness in terms of breathing phases in the subcostal approach. A human study indicated that the liver moved more in the superior-inferior direction than in the left-right direction , suggestThis study had several limitations. First, it was performed with a limited number of dogs, and only male Beagle dogs with similar body weight and age were included. Further studies with a larger number of subjects, various breeds, sexes, body weights, and ages are warranted. Second, cytological and histopathological examinations to exclude the possibility of liver disease were not performed. However, the Beagle dogs in this study were relatively young and exhibited no clinical signs of illness and abnormalities on physical examination, blood examination, radiography, and ultrasonography. Third, dogs with hepatic fibrosis were not included. In human elastography, liver stiffness differs significantly between the inspiratory and expiratory phases in patients with liver fibrosis, but not in healthy individuals . Fourth,2O in the intercostal approach and 10, 15, and 20 cm H2O in the subcostal approach falsely increase liver stiffness. In terms of scanning approach, the intercostal approach may reduce undesired increases in liver stiffness. Therefore, when performing 2D-SWE in dogs, liver stiffness should be interpreted considering these confounding factors.In conclusion, this study demonstrates that 2D-SWE is capable of measuring liver stiffness in dogs without being confounded by the effects of anesthesia and free-breathing. Further, deep inspiratory phases including 15 and 20 cm HThe raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The animal study was reviewed and approved by Institutional Animal Care and Use Committee of Konkuk University .JC contributed to the study design, data collection, data interpretation, and manuscript writing. JayK and JaeeK contributed to the data collection and data interpretation. JaehK and KE contributed to the study design, data interpretation, and manuscript editing. All authors reviewed and approved the final submitted manuscript.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.


Policymakers, practitioners, and researchers need a balanced, thoughtful, and analytical resource to meet the challenge of global aging at a rate that’s historically unprecedented. The Journal of Aging & Social Policy (JASP), which was founded in 1989, serves this role by drawing contributions from an international panel of policy analysts and scholars who assume an interdisciplinary perspective in examining and analyzing critical phenomena that affect aging and the development and implementation of programs for elders from a global perspective. Study settings extend beyond the United States to include Europe, the Middle East, Australia, Latin America, Asia, and the Asia-Pacific rim. This presentation will document the scope, content, and focus of JASP, including the rise of international submissions, which now account for approximately half of articles published. Opportunities for publishing in JASP will be discussed; so too will strategies for navigating the peer-review process successfully.


Trypanosoma brucei (T. brucei), the axoneme is accompanied by a paraflagellar rod (PFR) that supports non-planar motility and signaling necessary for disease transmission and pathogenesis. Here, we employed cryogenic electron tomography (cryoET) with sub-tomographic averaging, to obtain structures of the PFR, PFR-axoneme connectors (PACs), and the axonemal central pair complex (CPC). The structures resolve how the 8 nm repeat of the axonemal tubulin dimer interfaces with the 54 nm repeat of the PFR, which consist of proximal, intermediate, and distal zones. In the distal zone, stacked “density scissors” connect with one another to form a “scissors stack network (SSN)” plane oriented 45° to the axoneme axis; and ~370 parallel SSN planes are connected by helix-rich wires into a paracrystalline array with ~90% empty space. Connections from these wires to the intermediate zone, then to overlapping layers of the proximal zone and to the PACs, and ultimately to the CPC, point to a contiguous pathway for signal transmission. Together, our findings provide insights into flagellum-driven, non-planar helical motility of T. brucei and have broad implications ranging from cell motility and tensegrity in biology, to engineering principles in bionics.Eukaryotic flagella (synonymous with cilia) rely on a microtubule-based axoneme, together with accessory filaments to carryout motility and signaling functions. While axoneme structures are well characterized, 3D ultrastructure of accessory filaments and their axoneme interface are mostly unknown, presenting a critical gap in understanding structural foundations of eukaryotic flagella. In the flagellum of the protozoan parasite  In humans, flagellum motility and signaling are essential for normal development, physiology, and reproduction4. In protists and fungi, flagella enable navigation through diverse environments8, direct movement and interaction of gametes for reproduction10, and contribute to transmission and pathogenesis of microbial pathogens14. The structural foundation of the flagellum is the axoneme, a microtubule-based molecular machine that drives motility and provides a platform for assembly of signaling machinery15. In addition to the axoneme, flagella of many organisms contain accessory structures, such as outer dense fibers and fibrous sheath of human sperm16, mastigonemes of algae17, and the paraflagellar rod (PFR) of euglenoids and kinetoplastids19. Biochemical and genetic analyses have demonstrated that these extra-axonemal structures contribute to flagellum motility and signaling functions, but the structural foundation for how they achieve this is unclear22. Recent studies have resolved structures of the axoneme and axoneme subcomplexes in great detail, providing important insights into mechanisms and structural foundations of flagellum function28. However, much less is known about 3D ultrastructures of extra-axonemal filaments, and this presents a gap in understanding structural foundations of flagellum function in eukaryotes.Eukaryotic cells depend on flagella  4-731. The exact function of the PFR is not known, but it is required for cell motility, and studies of mutants lacking major portions of the PFR suggest it provides elastic resistance to axoneme bending32. Such internal resistance would be required for efficient movement in viscous environments where an organism must push against high external resistance, e.g., blood and other tissues encountered by T. brucei33. T. brucei motility is characterized by a vigorous, non-planar helical motion that must accommodate frequent flagellum beat reversals and collisions with external structures36. Therefore, the PFR must have flexibility while maintaining structural integrity. The PFR also provides a platform for cAMP and Ca++ signaling systems that control motility and host–pathogen interactions42, and for metabolic activities that may participate in energy transfer within the flagellum43. Trypanosome motility and PFR-dependent cAMP signaling are required for transmission and pathogenesis of these deadly pathogens39. Therefore, the PFR presents both a model for understanding functions of extra-axonemal structures of eukaryotic flagella, and an attractive drug target in a group of organisms that pose a substantial global public health burden.Among the most enigmatic of extra-axonemal structures is the PFR of euglenoids and kinetoplastids, a taxonomic group that includes several human and animal pathogens, such as cei Fig.  and rela46 and conventional electron microscopy and early tomography studies have provided a low resolution model for PFR structure50. However, high-resolution 3D structures of the PFR and the PFR-axoneme interface are not available. Consequently, how the PFR and axoneme combine to direct and regulate the hallmark non-planar helical movement of T. brucei36 remains a mystery.Proteomic and biochemical analyses have provided information on PFR composition51, to determine the structure of the entire T. brucei axoneme with PFR. The sub-tomographic averaged structure of the PFR distal zone reveals a largely hollow architecture comprised of planar networks of stacked “scissors densities” placed each 54 nm along and oriented at 45° to the axoneme axis and connected by thin “wire densities”. Such an architecture suggests tensegrity52, rather than space-filling observed in other cellular structures53, as the means to achieve competing needs of integrity and flexibility. Structural features of wire densities are reminiscent of bundled helices, consistent with secondary structure predictions of major PFR proteins. Based on the sub-tomographic averaged structure of the PFR-axoneme interface and interconnections within the PFR, our work also provides details on interconnections within and between the PFR and axoneme that may provide a means for signaling within these complexes suggested previously54. Together, our results provide insights into flagellar motility of T. brucei and have broad implications regarding functions of extra-axonemal filaments that are a common, yet enigmatic feature of eukaryotic flagella.Here, we have employed a combination of cryoET with Volta phase plate (VPP), energy filtering, and direct electron-counting imaging, together with sub-tomographic averagingT. brucei flagellum poses two major challenges for structural studies: possible structure distortion due to increased sample thickness and restricted flagellum orientation on the cryoEM grid due to deviation from circularity. To cope with these challenges, we developed a procedure to evaluate the width of the axoneme prior to recording26 and relied on sub-tomographic averaging with wedge-mask differences55. We also used a machine learning-assisted method to compensate for the missing wedge problem . Tilt-series of T. brucei detergent-extracted flagellum samples from bloodstream form parasites were recorded in a Titan Krios electron microscope equipped with a VPP, an energy filter and a direct electron detector in electron-counting mode. Tomograms . A 54 nm repeat interval is consistent with earlier measurements of 54−57 nm50. Since 54 is not a multiple of 8, resolving the details of axoneme and PFR structures simultaneously by sub-tomographic averaging is not possible. We therefore had to design a stepwise workflow incorporating both interactive and automatic particle-picking strategies  to obtain sub-tomographic averaged structures for individual flagellum components, and then fitted them into a montage  studies, the PFR consists of three structurally distinct zones: proximal, intermediate, and distalams Fig. . One canage Fig.  , together with the PEET program58, we were able to iteratively identify and refine the paracrystalline lattice parameters of the distal zone, first in one dimension along the axoneme axis and then in all three dimensions   Fig. . Sub-tomds) Fig. .Fig. 2Stα, β, γ at 76°, 78°, and 79°, respectively  nor orthogonal to dimension 48, nor helical44. Rather, when examining from the top of the axoneme down to the PFR , dimension 49. Dimension 50. Density scissors stack vertically upon one another along dimension 3), with 4−6 scissors per stack. Each stack in turn connects horizontally with adjacent scissors stacks, forming a planar network of stacks, which we term a “scissors stack network” plane (SSN plane), that is oriented 45° to the axoneme axis. Each SSN plane encompasses 5 stacks, 1 with 5 pairs of scissors, 3 with 6 pairs of scissors, and one near the boundary of the PFR on DMT4 side with 4 pairs of scissors but with densities exhibiting differences from the other 4 stacks. Thus, a 20 µm long PFR would include ~370 SSN planes with ~27 pairs of scissors per plane.The refined paracrystalline lattice is triclinic  with the unit lengths of vectors ely Fig. . The dimentclass1pt{minimaPFR Fig. , h2, dim}a⇀ Fig. , h3, witExtending between SSN planes are thin densities, which we call wires. When viewed parallel to SSN planes Fig. , wires fTo interpret structures constituting the unit cell of the distal zone, we examined elements that make up each SSN plane . In our sub-tomographic averaged structure, the lengths of individual rod-shaped density wires range from 40 nm to 45 nm. The diameter of the wire, ~4 nm, would accommodate a coiled coil of 3−4 helices   Fig. .Fig. 5St65. Our structure reveals PAC7 is actually comprised of four components  on DMT6 . Viewing from this perspective, we also observe a lattice-like arrangement of diagonally intersecting densities  and the PFR (54 nm) is reminiscent of symmetry mismatch often observed in structures involved in dynamic biological processes, such as those of the DNA translocation portals in virusesace Fig. , as thisMT5 Fig. 49 will e86.In summary, our studies provide a high-resolution 3D description of an extra-axonemal structure, giving insight into how these common yet enigmatic components of eukaryotic flagella contribute to axonemal beating. From the standpoint of bionics, with less than 10% space filled, the PFR of trypanosomes may provide an example of cellular tensegrity—biological entities that embody a fine balance between strength and flexibility, owing to opposing forces of compression or tension—and should inform future bioengineering and mechanical design of nanomachines and microswimmersT. brucei bloodstream form single marker (BSSM) cells87 were used, and details for culturing, flagella isolation, and cryoET were described previously26. Briefly, demembraned flagella were isolated and vitrified on quantifoil grids with 5 nm gold particles. With SerialEM88, tilt series were collected from straight segments near the center part of full-length flagella, spanning the middle third between the basal body and tip, in a Titan Krios instrument equipped with a VPP, a Gatan imaging filter (GIF) and a post-GIF K2 direct electron detector in electron-counting mode. Frames in each movie of the raw tilt series were aligned, drift-corrected, and averaged with Motioncorr89. The tilt series micrographs were aligned and reconstructed into 3D tomograms by either weighted back projections  or simultaneous iterative reconstruction technique  using the IMOD software package90. The contrast transfer function (CTF) was determined by ctffind491 and corrected with the ctfphaseflip program92 of IMOD. With phase plate, the CTF is insensitive to the sign of the defocus value being negative (under-focus) or positive (over-focus)93 so CTF of micrographs obtained with phase plate were approximated when CTF rings were not readily detected.T. brucei flagella samples typically lie on the cryoEM grids with a preferred orientation due to the presence of the PFR. To alleviate the missing-wedge problem associated with preferred orientation, we used a novel deep learning-based method developed to compensate for missing-wedge problem . Using tilt geometry and resulting tomograms as inputs, the program iteratively learns how to fill in missing information.Demembranated PEET, each particle is a 3D sub-volume of the tomogram corresponding to the repeating unit of the component of interest, i.e., PFR distal zone, PFR proximal zones, PACs, or CPC.In our sub-tomographic averaging scheme performed using PEET trials, and then using this defined repeating unit to re-pick particles automatically for the final round of PEET refinement, leading to a final sub-tomographic average at the best possible resolution.For the PFR distal zone, sub-tomographic averaging required first defining the repeating unit through multiple rounds of x, y, z coordinates of two points in the tomogram, one at each end of a tooth. The coordinates for all picked particles in each tomogram were saved into a coordinates model.mod file. With this model file as the input, we then ran stalkInit of the PEET package to generate three output files—motive list.csv file (translation and rotation parameters), coordinates model.mod file  and rotation axes.csv file —for each tomogram. All these picked particles were summed together to generate a featureless volume, which was used as the initial reference of the first cycle of PEET. We then ran PEET iteratively by gradually decreasing the search range for both angular and distance parameters. For the angular search range, the parameters decreased from “180° max with 60° step in Phi (y axis), and 9° max with 3° step in both Theta (z axis) and Psi (x axis)”, to “3° max with 1° step in all Phi (y axis), Theta (z axis), and Psi (x axis)”. For the distance search range, the parameters decreased from 10 pixels to 2 pixels along all three axes. In addition to decreasing the search ranges, the reference was also updated by using the result of the previous round of PEET sub-tomographic averaging. This process was iterated until the averaged structure converged, and no improvement in the averaged structure could be observed. In this converged average, repeating densities, characteristic of those ultimately resolved in the lattice in Fig. To define the repeating unit a priori, we first performed crude sub-tomographic averaging with 4x binned (resulting a pixel size of 10.2 Å) SIRT tomograms. Initially, we manually picked particles (190 × 190 × 190 pixels) by taking advantage of the repeating comb teeth visible in the PFR distal zone in the raw tomograms , a coordinates model file , and a rotation axes file  for each tomogram—generated from the above PEET round. The output includes a single prm file (file pathway information) for the entire project and a new set of three alignment files for each tomogram to be used as the input files for the next round of PEET. This re-picking process ended up with 22 times as many particles as in the initial manual picking process.The repeating unit parameters defined above were utilized to re-pick particles following the 3D lattice. To do this for many tomograms automatically, we developed a bash script, PEET refinement was performed by loading the new alignment and prm files to generate the final sub-tomographic average for the PFR distal zone. As before, the search ranges were gradually decreased and the average result from each prior refinement cycle was used as the updated reference for the subsequent cycle of refinement. The refinement was terminated when the averaged structure converged, and no further improvement could be seen. From the unMasked averaged density map file automatically generated by PEET during the refinement, the repeating length along the axoneme axis was measured to be 54 nm. Unit cell dimensions were also measured as reported as the final parameters in Fig. With these re-picked particles, one round of iterative propagate because the repeating unit is only one dimensional. Instead, we identified prominent repeated densities from raw tomograms to be used for manual particle picking. For example, we used the baseplate density attached with 3 filaments 94, PFR1 (NCBI #AAV53924) of Angomonas deanei95 from the Strigomonadinae family, and PFR 1D (NCBI XP_003872382.1)96 of Leishmania mexicana from the Leishmaniinae subfamily. Sequences were aligned with multiple sequence alignment function in Clustal Omega (1.2.4)97. For each of the four proteins, secondary structures were predicted using PSIPRED98. Predicted secondary structures of proteins were combined with protein alignment results to compare the PFR protein structure between different species.For PFR protein sequence alignments, we used PFR1 (NCBI# XP_844025.1) and PFR2 (NCBI# XP_847331.1) from IMOD90 and UCSF ChimeraX99 were used to visualize reconstructed tomograms and sub-tomographic averages. Segmentation of densities maps was performed by the volume tracer and segger tools of UCSF Chimera100. For surface rendering with UCSF ChimeraX, maps were first low-pass filtered to either 30 Å or 50 Å. Montage was done in UCSF ChimeraX by fitting averaged structures  into an unaveraged tomogram after missing-wedge compensation. Fitting of existing model of coiled-coil helix bundle was done with the molmap and fit functions in UCSF ChimeraX99. Schematics were drawn by Adobe Illustrator. The built-in denoising program in Warp101 was used to enhance visualization. Tilt series were separated into two sets and reconstructed independently, and the noise will be filtered out to improve the SNR given that the signal is consistent in both maps, but the noise is random.Supplementary InformationSupplementary Movie S1. Density slices through a representative tomogram.Supplementary Movie S2. 3D montage showing a 1248nm segment of the flagellum axoneme and PFR.Supplementary Movie S3. Surface view of the averaged PFR distal zone.Supplementary Movie S4. Surface view of the averaged connections of wire 1 and 5.Supplementary Movie S5. Surface view of the averaged PFR proximal zone with PAC7 baseplate.Supplementary Movie S6. Surface view of the averaged CPC.


BPH is commonly found in older men which can lead to lower urinary tract symptoms. Magnetic resonance elastography (MRE) is an innovative, noninvasive imaging technique used to evaluate tissue stiffness. There has not been any study, however, that assessed the tissue stiffness in patients with BPH. A prospective descriptive study was performed to demonstrated MRI and MRE techniques of the prostate gland in ten patients with BPH to assess tissue stiffness, features of BPH on MRI and components of BPH in the area of increased stiffness.MRI and MRE examinations in all patients were successful without any complications. The mean tissue stiffness of the whole prostate gland was 4.40 ± 0.71 kPa with good reproducibility (ICC 0.82). Stromal components and mixed glandular-stromal components tended to be associated with the areas of increased stiffness on stiffness images, 50.6% for stromal components and 37.9% for mixed glandular-stromal components. Some MRI findings were seen on the patients with high mean stiffness values such as prostatic calcification, type-5 BPH pattern and large prostate volumes.Prostate MRE is a useful noninvasive reproducible diagnostic tool for evaluating prostate tissue stiffness by both qualitative and quantitative assessments. The mean prostate tissue stiffness from MRE in patients with BPH in this study was 4.40 ± 0.71 kPa. Some MRI features might be associated with increased tissue stiffness.Trial registration: PID 229. Registered 4 October 2019. http://md.redcap.kku.ac.th Benign prostatic hyperplasia (BPH) is a condition commonly found in older men. It can be found in 50–60% of men by the age of 60  and can BPH can be divided into two main components; glandular and stromal enlargements . GlandulThe Prostate Imaging Reporting and Data System (PI-RADS) has recommended that the measurement of the maximum AP and longitudinal diameters should be made on the mid-sagittal T2W image, and the measurement of the maximum transverse diameter should be made on the axial T2W image . The sizMagnetic resonance imaging (MRI) is frequently used for the detection and risk stratification of clinically significant prostate cancer (csPCa) because of its higher resolution than other modalities . BPH patMagnetic resonance elastography (MRE) is an innovative, noninvasive imaging technique. It can provide information about the biomechanical properties of soft tissue and quantitative assessment based on different stiffnesses between healthy and diseased tissues. The most widely used application of the MRE is detecting and staging liver fibrosis, which is currently performed in more than 100 centers worldwide .Many recent studies have assessed the utility of MRE in other organs such as the brain, muscle, and breast –15. OnlyKemper et al. assessed the feasibility of MRE in the prostate gland of seven healthy volunteers, using an external driver attached to the pubic bone on a 1.5 T scanner at a vibration frequency of 85 Hz, and found that the prostate gland had significantly higher stiffness than the adjacent fat tissue . After tThere has not been any study that assessed the tissue stiffness in patients with benign prostatic hyperplasia. Therefore, a prospective descriptive study to demonstrate the technical feasibility of prostate MRE using an external air driver and assess the stiffness of prostate tissue along with MRI features of the enlarged prostate gland in patients with BPH was conducted.This study was a prospective descriptive study from November 2019 to October 2020. The study protocol was approved by the Ethics Committee for Human Research.The inclusion criteria were (1) clinical or MRI features of BPH, (2) PIRADS (v. 2.1) score 1 or 2.The exclusion criteria were (1) prostate cancer (2) MRI artifacts that would affect an imaging interpretation.Ten patients were enrolled in the study. Written informed consent was obtained from all the subjects.All examinations were performed in a 3.0-Tesla MRI scanner  using a phased-array surface coil. To perform MRE and generate mechanical waves, a pneumatic system that incorporated an active driver (placed outside the scan room) for producing continuous acoustic wave motion was used. A passive driver was placed against the body surface superficial to the pubic symphysis to induce shear waves traversing the prostate gland. An air-filled plastic tube was used for transmitting the pneumatic excitations from the active to the passive driver. A small soft pad was also placed beneath the passive driver to decrease the patient’s vibrating sensation. The patient placed in the supine position, then a small soft pad and a passive driver are placed over the pubic symphysis. The passive driver and the pelvis were wrapped together by a kidney belt to ensure direct contact of the driver with the body surface. Finally, an anterior surface coil was set up before performing an MRI examination. A repetition frequency of the drivers at 60 Hz was used for the MRE study.Prostate MRI was performed using the routine prostate protocol as demonstrated in Table To image the shear waves and measure the propagation of the mechanical waves inside the tissue from the MRE, a 2D Phase Contrast Fast Field Echo (FFE) with motion-encoding gradients and a 15-s breath-hold per slice was applied. Depending upon the prostate gland size, two to five axial slices through the whole prostate gland were generally obtained to generate MRE images. Before imaging the shear wave, axial T2W images were acquired to position the prostate gland and to be used as an anatomical reference. Each wave image slice was acquired at eight evenly spaced time points. The MRE protocol is shown in Table Post-processing of the images displaying wave images, FFE/Modulus images and stiffness images was performed using MREView software  Fig. . Each piTwo abdominal radiologists with 9 and 23 years of experience reviewed MRI and MRE images by consensus. Both radiologists were blinded to stiffness values.The axial thin-slice T2W images through the whole prostate gland were used to determine the components of BPH. The proportion of BPH was classified into three categories: (1) glandular predominate (glandular component > 50%), (2) stromal predominate , and (3) equal glandular and stromal component. The BPH pattern was classified according to Randall’s classification . The dimFor the MRE assessment, the number of acquired slices, mean stiffness with SD, minimum and maximum stiffness (kPa) were recorded. The stiffness maps and T2W images were simultaneously interpreted to evaluate the components of BPH in the area of increased stiffness, which was defined by red or orange colors in the stiffness map.p < 0.05.Continuous data were demonstrated by their means and SD, or median and interquartile range. Categorical data were demonstrated by number and proportion. Comparisons of numerical data between groups were analyzed by using a nonparametric test. The intraclass correlation coefficients (ICC) between the measurements of two MRE examinations to evaluate reproducibility were done. The level of significance was set at r = 0.590; p = 0.021). The PSA level had no significant correlation with the prostate height (p = 0.383) or proportion of BPH (p = 0.237). Two patients underwent biparameter MRI (bpMRI) and eight patients underwent multiparameter MRI (mpMRI) before MRE examination. All subjects tolerated the mechanical vibration and scan protocol well. None had any complications from the MRI/MRE examination. The MRE examination time in each patient was less than 20 min.Eight patients had PI-RADS scores of 2 and two patients had PI-RADS scores of 2/3 due to disagreement between two reviewers. None of them had a PI-RADS score of 1. Baseline characteristics are displayed in Table From T2W images, there were four patients with a predominant glandular component, three patients with predominant stromal component, and three patients with equal glandular-stromal component. Nine patients had bilateral TZ and a retrourethral enlargement pattern (type 3) and only one patient had a pedunculated, bilateral TZ and retrourethral enlargement pattern (type 5) Table .Table 4Mp = 0.317 in first MRE and 0.035 in second MRE) . The number of acquired slices correlated with the height of the prostate gland. The group of 1–3 slices-acquired had an average prostate height of 4.90 ± 0.41 cm and the group of more than three slices-acquired had an average prostate height of 6.42 ± 3.46 cm (p = 0.08 for the first MRE and p = 0.01 for the second MRE). There were 87 areas of increased stiffness on stiffness images (43 from first MRE and 44 from second MRE). Forty-four areas  corresponded to a stromal component on T2W images. Thirty-three areas  corresponded to mixed glandular and stromal components. There was one area that was seen only on the second MRE, whereas, other areas were the same areas as seen on the first MRE. There were only four areas  that corresponded to the glandular component. Four areas in patient No#2  corresponded to right and left central zones and two areas in the same patient  corresponded to the urethra. All areas of increased stiffness seen on both first MRE and second MRE were the same areas in both examinations.The mean stiffness of the whole prostate gland was 4.40 kPa  . Maximum stiffness (ICC 0.74) and SD of the stiffness (0.65) had moderate overall reproducibility. Minimum stiffness had poor reproducibility (ICC 0.42). For analysis of the reliability of number of acquired MRE slices and number of areas of increased stiffness on stiffness images, it was found that there was excellent reliability between the two examinations (ICC 0.93 and 0.99).2).For per-patient results Tables , 5, the 2. He had the third-largest size of prostate gland (81.5 ml) and the third-highest average tissue stiffness (4.65 kPa). He had a BPH with type 3 and a predominant stromal component.Patient No#10 had the highest PSA and PSAD levels, 26.6 ng/ml and 0.33 ng/ml2) levels. He had the lowest tissue stiffness too.Patient No#3 had the lowest PSA (2.11 ng/ml) and PSAD  to shear modulus  conversion using the equation µ = ρVs2  was used. So the mean stiffness values of the entire prostate gland, peripheral zone, and central gland from Dittmann’s study were 5.02, 4.97, and 4.75 kPa, which were slightly higher than in the present study. There were limitations to compare the results of the current study to other previous studies due to differences in MR scanner, MRE hardware, protocol, technique, population, and post-processing software. From the present results, it can be recommended that further studies to evaluate the reliability of MRE in different settings should be done.The mean tissue stiffness of the whole prostate gland in this study was 4.40 ± 0.71 kPa when compared with the previous MRE studies of J. Kemper et al.  He perfoFor evaluation of test–retest reliability without repositioning of patients and driver, this study achieved good reproducibility (ICC 0.82) for mean stiffness and moderate reproducibility for maximum and SD of stiffness (ICC 0.74 and 0.65). Minimum stiffness had poor reproducibility (ICC 0.42). The different values between two tests might be caused by inhomogeneous waves traversing the prostate gland which was is a small organ located deeply in the pelvis and the movement of adjacent organs such as bowel peristalsis which might affect imaging acquisition. Excellent reproducibility was found for several acquired MRE slices (ICC 0.93) which mainly depended on the size of prostate gland, especially the prostate height. For analysis of the number of areas of increased stiffness on stiffness images, this study also found excellent reliability between two examinations (ICC 0.99). The study, however, did not reposition the subjects and actuators which might induce small changes in wave patterns and wave amplitudes. As the result of reproducibility analysis in the study of Dittmann F et al., they found good test–retest reproducibility despite repositioning of subjects and actuators between measurements  .For the analysis of MRI findings, there was a nearly equal proportion of BPH components in this study; four patients with predominated glandular component, three patients with predominated stromal component, and three patients with equal glandular and stromal components. Most patients (90%) had a bilateral TZ and retrourethral enlargement pattern (type 3) and only one patient (10%) had a pedunculated with bilateral TZ and retrourethral enlargement pattern (type 5). These results were potentially the same as the Randall et al. classification . There wFor the analysis of focal areas of increased stiffness seen on stiffness images, about half of them (50.6%) corresponded to a stromal component on T2W images and more than one-third (37.9%) correspond to mixed glandular and stromal components. Additionally, it was found that the glandular predominant group tended to have a lower maximal stiffness than when stromal predominant or equal in its glandular-stromal component. These results supported the review of Wasserman et al.  that theMost other findings found in MRI were minimal ascites in the pelvic cavity, a small area of hemorrhage in the prostate gland and small prostatic utricle cysts which were not corresponding to areas of increased stiffness on stiffness images. Therefore, it can be assumed that these findings might not cause an increase in tissue stiffness. The study found, however, that some features which were seen on patients with high mean stiffness values including prostatic calcification, type-5 BPH pattern and the large prostate volume, it was possible to make an hypothesis that these features might be associated with an increase in tissue stiffness. Further study with more subjects would give more information about this hypothesis.To the best of our knowledge, this study is the first study to exclusively describe MRE of the prostate gland in Thailand. There are several limitations to the study. Firstly, the study was a prospective study which had too small a number of subjects. Patients recruited into the study were less than was expected because of the Covid-19 situation in the country. Secondly, there might be a selection biases especially in the population-based selection from BPH patients with high PSA levels who were requested to have an MRI to screen for prostate cancer. Other patients with BPH may have more findings. Thirdly, the study had no healthy volunteers to compare the results with which would make a more reliable study. Fourthly, it did not demonstrate the pathological diagnosis which is the gold standard for diagnosis of BPH and its correlation to MRI and MRE findings. Lastly, it tried to perform prostate MRE using the drivers and post-processing software which were developed for measuring stiffness in the liver for the staging of liver fibrosis. The protocol might not be suitable for measuring stiffness in prostate gland so the results in the study might not represent valid tissue stiffness values. It is believed, however, that the results of the study would be beneficial for the development of an MRE protocol as an additional diagnostic tool for evaluating prostate disease and a guide to study more about prostate MRE in the future.Prostate MRE is a useful noninvasive reproducible diagnostic tool for evaluating prostate tissue stiffness in both qualitative and quantitative assessments. The mean prostate tissue stiffness from MRE in patients with benign prostatic enlargement in this study was 4.40 ± 0.71 kPa. Some MRI features might be associated with increased tissue stiffness.


The use of biodegradable packaging material as an alternative to conventional petrochemical-based polymers is based on the environmental issues associated with conventional materials. This review aims to update the existing knowledge regarding the application of starch-based biodegradable films for food packaging. From the review, it was evident that starch stands out among biopolymers due to its abundance and cost effectiveness. This review is the first of its kind, having reviewed over 100 articles/publications on starch-based biodegradable films, consolidating their current state of research and their applications for food packaging; therefore, this review provides an insight into the utilization of nanomaterials to improve the shelf life of packaging of food. The use of plastic for food packaging in the food industry has shown an annual growth rate of 5% over recent decades. At present, plastic is recorded as the second most widely used material for food packaging . This paHowever, there are certain limitations in the plastic degradation process, because it takes a long time, thus impacting negatively on the environment ,4. Some Recent review studies relating to starch-based biodegradable films have been focused on biodegradable polymer trends , materia2 in the global ecosystem. Despite these advantages and benefits, disadvantages include poor mechanical properties, low water stability, high moisture sensitivity, presence of a poor moisture barrier because of strong hydrophilic behaviour, their brittle behaviour at room temperature, and their high moisture content [Starch is a good source of biodegradable material for food packaging, originating from wheat, corn, rice, and potatoes . It is w content . To over content , the add content . More in content . Differe content .Starch is mainly sourced from plants but can also originate from roots, tubers, cereals, and legumes. Considering its inherent biodegradability, abundance, and annual renewability, starch is a promising natural polymer. Interestingly, previous studies have revealed that starch contains two kinds of microstructures: linear and branched. Hence, it is regarded as a heterogeneous material. The linear structure is known as the amylose , while the branched structure is called the amylopectin .In the production of starch-based films, plasticizers are necessary to curb the effect of brittleness due to polymer chain interactions. Plasticizers tend to improve mechanical properties, reduce the tension of deformation, hardness, density, and viscosity, and increase polymer chain flexibility and resistance to fractures ,24. We hStarch comes from corn, wheat, potato, cassava, and rice, as shown in The previous section established that starch is a good biodegradable material for food packaging, particularly for dry products, fruits, and vegetables. In this section, the effects of these starch-based films as a substitute for plastic are discussed See .Locally, starches are obtained from numerous sources, which include cereals, tubers, and roots. Recently, there has been an increase in starch production due to an increase in demand. In terms of production capacity, China and Brazil are topping the list, accounting for about 10% increase per year, and other countries have shown around 1–2% growth per year . From thDuring the extrusion processing of starch, most amylose remains in amylopectin due to lower water content. Amylopectin is known to have a short-branched chain, which can be torn apart during gelatinization. This is a result of the formation of a double-helical crystalline structure. Gelatinization occurs at a lower water level due to the shear forces, which affect the starch granules, thereby permitting water transfer into the interior molecules .Studies have been conducted regarding starch processing by extrusion, revealing that a decrease in the rate of amylopectin fragmentation with a decrease in screw speed results in an increase in temperature of around 121–177 °C ,52,53. AIpomoea batatas is a major source of extraction, particularly in an environment where 95% of the world’s food production depends on starch [Starch extraction is a key step in the production of starch-based biodegradable films for food packaging. The extraction of starch from yam and taro was conducted by Andrade et al. . Using an starch .3 chunks. After that, it was washed using distilled water and refrigerated. With the aid of a double-screw-waring blender, the 100 g diced cassava pulp was blended at a low speed for 1 min. The chilling process was employed to minimise the starch gelatinization during blending. The formed cassava mash was dissolved after being transferred into a conical flask of 600 mL, to which was added 100 mL of distilled water.In a study by Agyepong and Barimah , starch In a study by Tejavathi et al. , starch The ethanol method was seen as one of the methods used to extract starch, as confirmed in a study by Ramil et al. . In the Having briefly discussed the extraction of starch, the extracted starch is used to form starch-based biodegradable materials by the application of heat to form a filmogenic solution. It is interesting to note that starch with high amylose content is preferred for this purpose because of the bigger crystalline domain, which gives greater mechanical resistance . HoweverMost of the applications of starch-based biodegradable material in the literature have been carried out at a laboratory scale rather than at an industrial scale. In a study by Molaee Aghaee et al. , the resLactobacillus rhamnous was studied by Soukoulis et al. [L. rhamnosus by 3–7-fold around the nearness of protein with sodium caseinate. The study was concluded by calculating the shelf life of the films. The results showed that, in accordance with the framework of the premise of 6 log practical CFU/g, the measure was extended at 27–96 days and 15–24 days at ice chest or room temperature, respectively.In another study, the effect of starch protein films on s et al. . The scoA comparison study focusing on the main and physical features of chitosan and altered starches of edible films was examined by Garcia et al. . The filS. burchelli phosphate starches, and observe the development of coasting and its application to cherry tomatoes through post-harvest conservation. The following measurements were conducted during the study: the thickness of the film, the solubility in water, and the permeability by water vapour. The methodology of the study involved comparing the conservation of the cherry tomatoes with and without coverage at the following conditions: time—21 days; temperature—10 ± 2 °C; relative humidity—80 ± 5%. The study revealed that factors such as reduction in water solubility, increase in permeability, and characteristics of the films were usually affected by the concentration of the glycerol and the type of starch used. In addition, it was reported that fruits with an edible coating showed a greater permeability by water vapour, especially for the conservation of cherry tomatoes. This was attributed to the gradual decrease in the film during storage compared with the control from an experimental point of view. The study’s objective was successfully established, proving that the concentration of glycerol affects consumable films and should allow for ideal post-harvest use.The aim of a study conducted by Gomes et al.  was to cAdjouman et al.  conducteXiaoyang et al.  recommenTo keep foods from being infected by fungi and bacteria and for the purpose of long-term storage, nanotechnology is essential . Additio2) or oxygen (O2). These gases negatively impact the shelf life of the food products and act as an obstacle that hinders microorganism activities. This acts as one of the advantages of nanomaterials in food packaging. According to Brody [According to Joye et al. , Khare eto Brody , Joye etto Brody , Khare eto Brody , and Yokto Brody , the useInterestingly, nanotechnology can be classified into food nanosensing and nanostructured food ingredients . Food naHaving established the fact that the use of nanomaterials or nanotechnology in food packaging improves food quality and safety, it would be interesting to briefly review these materials in starch-based films . Material for food packaging using starch-based biodegradable films must be durable. To accomplish this, starch-based nanomaterials are necessary. One main function of the starch-based nanomaterial is to reduce the weakness of the natural polymer in starch . Starch Considering a few studies on starch-based nanotechnology and its effects, the utilization of different concentrations of graphene oxide and its response to starch–graphene oxide composite film was studied by Wu et al. . The stu2.Furthermore, the incorporation of the starch film with multi-walled carbon nanotubes was carried out by Shahbazi et al. . From thAdditionally, through the hydrolysis method with pullulans, corn starch films were prepared with the aid of taro starch nanoparticles (TSNP). The methodology decreases the vapour permeability and increases the opacity because of the addition of TSNPs to the starch source (corn). From the experiment, Dai  reportedIn another study based on the reinforcement of rice-starch-based film with starch nanocrystal, conducted by Piyada et al. , the tenAdding nanoscale particles improved the crystallization kinetic, crystalline morphology, crystal form, and crystalline size of the starch. Interestingly, MMT nanoclays are promising fillers for biodegradable packaging. This is because they are less expensive, and they are effective and stable . The MMTVarious calls from consumers have brought about the need for extended shelf life in the food industry. There is a need to meet the desire for food quality to be highly maintained throughout purchase and consumption. By definition, the shelf life of food deals with the safety of food products to retain the desired sensory, chemical, physical, and microbiological characteristics . For extCompositional and environmental factors can influence the evaluation of a product’s shelf life . ComposiAccording to Primozic et al. , these mNot many studies have been carried out regarding the shelf life evaluation and design. According to Kilcast and Subramaniam , shelf lMicrobial safety should be considered during the design of shelf life. For instance, in the process of frozen storage, biochemical changes take place in the frozen products. To avoid this, microbiological testing results are necessary before samples are tested for other qualities. For accelerated evaluation, the temperature differences (5–10 °C) vary. In this case, high-temperature storage methods are avoided . ConsideBefore concluding the study and recommending areas for future studies, it is necessary to briefly look at the major challenges faced by starch-based biodegradable films for food packaging. Although the disadvantages have been mentioned, poor mechanical behaviour and high water vapour permeability (mass of water vapour transmitted through a film area within a defined time) are the main challenges or drawbacks associated with starch-based biodegradable films. The poor mechanical behaviours are determined by tensile tests and they include the tensile strength, the strain at break, and the elasticity modulus . In relaThis review succinctly accounted for the current state of research and applications of starch-based biodegradable films for food packaging. The study was motivated by the necessity of finding a substitute (biodegradable starch film) for the conventional synthetic plastic currently in use. Although biodegradable starch films are associated with poor properties, the utilisation of nanomaterials tends to enhance the brittleness and physical behaviour of the films for food packaging. While nanotechnology offers various potentials in food packaging—as a result of its functions from bio-based packaging to smart packaging in the food sector, as well as improving food quality and safety—further study is recommended to ascertain the advantages and disadvantages of using nanotechnology in food packaging materials. The issue of moisture sensitivity was identified as a limitation in the use of starch-based materials for food packaging. As further observed, the tensile strength and adequate water vapour permeability of the films can be attributed to the hydrophilic nature of starch. This makes starch-based films susceptible to moisture uptake. Hence, to enhance the resistance of starch-based materials to moisture and mechanical properties, various blending and composting techniques are required, such as coating (acrylate-epoxidized soybean oil). Addition of acrylate-epoxidized soybean oil reduces moisture sensitivity and increases the gas permeability of the starch-based films. To improve the surface adhesion or bonding between starch and acrylate-epoxidized soybean oil coating, polyethylenimine (PEI) is recommended. With regards to the evaluation of shelf life, food materials packed using starch-based films provide a platform for microbial spoilage of stored foods. To avoid this, it is recommended that the use of essential oils with antimicrobial and antibacterial potentials or properties should be employed. This provides a remedy to such limitations.Further work should focus on improving the performance of starch-based films by reducing their moisture sensitivity, while considering the balance between different chemical treatments for reducing moisture sensitivity and biodegradability. During the review, it was observed that studies regarding starch-based materials in other applications, such as in use as fertilizers and in water treatments, have a lot of potential and interest. Therefore, there is a need for researchers and academics to examine this direction.


This paper presents a graphical method for determining the linearized stiffness and stability of prestressed trusses consisting of rigid bars connected at pinned joints and which possess kinematic freedoms. Key to the construction are the rectangular areas which combine the reciprocal form and force diagrams in the unified Maxwell–Minkowski diagram. The area of each such rectangle is the product of the bar tension and the bar length, and this corresponds to the rotational stiffness of the bar that arises due to the axial force that it carries. The prestress stability of any kinematic freedom may then be assessed using a weighted sum of these areas. The method is generalized to describe the out-of-plane stability of two-dimensional trusses, and to describe three-dimensional trusses in general. The paper also gives a graphical representation of the ‘product forces’ that were introduced by Pellegrino and Calladine to describe the prestress stability of trusses. Here, we extend the methods to describe the stability of such structures. The case of interest is known as ‘prestress stability’ and it concerns structures which possess at least one mechanism which may be stabilized or destabilized by the geometric stiffness effects that arise from the axial forces carried by the structural members.form diagram, while the force diagram represents an equilibrium set of axial forces within that truss. In this paper, the methodology is extended to quantify the stiffness that arises due to the presence of forces within the members, allowing the stability to be assessed. Following Maxwell ,2 the grundeformed shape.Such tension stiffening and compression de-stiffening are not described by the simplest structural theories where equilibrium equations are written at the undeformed configuration. While better theories can describe buckling and tension stiffening, the inability of traditional matrix formulations of structural mechanics to undergo such destabilization persists even into the large finite-element packages routinely used in structural analysis. An analyst will need to create a considerably more sophisticated model in order to successfully simulate such stabilizing and destabilizing effects. While it would be tempting to describe these as higher-order effects, this is not strictly correct: the instability phenomena have been missed because the equilibrium equations were written at the stress matrix that plays this role, and that will be the primary study of this paper. This paper begins by showing how the terms of the stress matrix may be represented first vectorially and then graphically, giving examples of simple structures.In this paper, we thus require a clear statement of structural behaviour which considers equilibrium at the deformed shape. Building on work of Pellegrino & Calladine –6 and CoBefore looking at stability, graphic statics is first employed in the initial equilibrium step, establishing the reciprocal diagrams of form and force. This may be readily accomplished by the traditional technique of constructing lines in the plane. However, the analysis gains power by the introduction of polyhedral Airy stress functions, whose existence follows from Maxwell’s observation  that recet al. , respectively. If the displacements at nodes 2 and 3 are  = δ such that the bar rotations are δ/H, then the total potential energy is (1/2)(5 + 16 + 5)(WH)(δ/H)2 = (1/2)(26W/H)δ2, with prestress stiffness 26W/H. —the abutment nodes 1 and 4 do not move and thus are represented by points at the origin of the displacement diagram; —c;the point representing node 3 must lie on line 3 that rises at the 2 : 1 slope from the origin perpendicular to bar  —a direction;the point representing node 2 must lie on line 2 that rises at the 2 : 1 slope and is offset from the origin by Δ in the bar  —b the points representing them must lie on a vertical line.because nodes 2 and 3 are connected by the horizontal bar We now apply compatibility to determine the effect of reeling in the cable from the left support. In this example, the cable is assumed to be inextensible. Compatible displacement diagrams can be readily constructed but they are not unique. a shortening.px3, py3] = . These satisfy the above requirements, each lying on the y-axis of our displacement diagram. (For Δ = 10 mm, Any configuration satisfying these conditions is a compatible configuration. For example, in his matrix analysis, Pellegrino chooses the configuration px2, py2 , px3, py3] =  will also be compatible. The question is thus to find the appropriate combination which satisfies equilibrium.However, addition of an arbitrary multiple of the inextensional mechanism  and the corresponding product forces have the form W/H. It is interesting that the two shapes differ.The figure 19p 2 = W/H at node 2 will be kept as the separate contributions p a2 = W/H and p b2 = W/H.For the geometric construction, it is preferable to leave the product forces in terms of the separate contributions from each bar. For example, the total product force As explained in Pellegrino , at equiAt each node, the product forces are broken down into the contribution from each connecting bar, such that the contribution of each bar to the total summation can be represented by the area of the quadrilateral having the bar as one diagonal. In this case, the quadrilaterals are parallelograms. The sign of each oriented area is given by the direction of rotation of the product forces at either end of the bar.h = 12t, where h and t are defined in the diagram.Each parallelogram can be readily decomposed into constituent rectangles whose areas are readily computed. Orthogonality requires the total oriented area to be zero. The solution so obtained is presented in . 7TL in the Maxwell–Minkowski diagrams that unify the reciprocal form and force diagrams of a loaded truss give a powerful pictorial representation of the rotational geometric stiffness of the truss members that arise due to the forces in those members. Whether or not a given kinematic freedom is stabilized or destabilized by the presence of the internal forces is determined by the sign of a weighted sum of these stiffnesses.This paper has shown how the geometric stiffness and prestress stability of pin-jointed trusses possessing a kinematic freedom may be determined graphically, without recourse to the matrix algebra that underpins earlier formulations. The paper is thus a further contribution to the recent renaissance of graphic statics, bringing stiffness and stability considerations within its compass. A key result was that the rectangular areas The presentation here is restricted to the small displacements of two- or three-dimensional pin-jointed trusses with axially inextensional bars and with only a single kinematic freedom. The generalizations of this theory which describe the stiffness of trusses with numerous kinematic freedoms, with extensionable members and for large displacements are presented in companion papers ,17,18, iClick here for additional data file.


High-translucency monolithic zirconia were developed to combine the esthetics of all ceramic restorations with the strength properties of zirconia. The purpose of this study was to compare the color stability of high-translucency monolithic zirconia ceramics with lithium disilicate luted using light-cure versus dual-cure resin cements following thermocyclic aging.n = 10) as follows; LiDi/LC: lithium disilicate luted by light-cure resin cement; LiDi/DC: lithium disilicate luted by dual-cure resin cement; Zr/LC: zirconia luted by light-cure resin cement; and Zr/DC: zirconia luted by dual-cure resin cement. Color analysis of the specimens was performed before and after 3000 thermal cycles by means of spectrophotometry. The CIE L*a*b* values of the specimens were measured, and data were analyzed statistically at a significance value of p < 0.05.Forty specimens, each composed of 10 × 10 × 1 mm ceramic slice luted to dentin surface of an extracted tooth, were prepared and assigned into four groups .Thermocycling resulted in a significant change in color coordinates of specimens with an overall At 1 mm restoration thickness, the color stability of high-translucency monolithic lithium disilicate and zirconia ceramics were not significantly different irrespective of the cement type used.Clinical implication Understanding the difference in color stability of dental ceramics may help in determining long-term esthetic result. As the expected standards of the public in the area of dentistry have increased, so has the need for tooth-colored restorations with superior properties. Consequently, various tooth-colored restorations with superior esthetic and mechanical qualities have been developed. Lithium disilicate glass ceramics are commonly used nowadays due to their high strength, adequate bonding to tooth structure, easy construction procedure, and acceptable esthetic appearance . NeverthThe optical and mechanical properties of highly translucent ceramic materials have been compared in few recent studies , 3. ChurTo determine the effect of thermocycling on the color coordinates of the luted ceramic material.To determine the effect of the ceramic type and/or cement type on the color coordinates of the luted ceramic material.To compare the color stability of luted lithium disilicate ceramic to that of luted zirconia ceramic.The null hypothesis of the study was that the color stability of high-translucency monolithic lithium disilicate and high-translucency zirconia ceramics luted with light-cure or dual-cure resin cements are the same after thermocycling.Color stabilities of monolithic ceramics and composite resin cements have also been reported. Putra et al.  have repForty extracted sound human premolars were chosen for this study after obtaining an ethical approval (#116-10-18). Teeth were extracted for orthodontics reasons. Immediately after extraction, remnants of soft tissue were removed using hand scaler. All teeth were assessed for visible fractures or discoloration. The dimensions of the occlusal surfaces of the crowns were measured using periodontal probe. Only sound teeth with 7–8 mm mesio-distal dimension and 8–9 mm bucco-lingual dimension were included in this study. Teeth roots were mounted in cylindrical mounts of self-cure acrylic resin (GC AMERICA INC). Subsequently, the teeth were stored in normal saline at room temperature. Occlusal enamel of all teeth was removed by occlusal reduction up to dentin using a diamond wheel on a high-speed handpiece . Forty (10 × 10 × 1 mm) ceramic slices were prepared from high-translucency monolithic lithium disilicate blocks (A1 shade) and high-translucency monolithic zirconia disc (A1 shade); twenty lithium disilicate slices  and twenty zirconia slices . Ceramic blocks and disc were cut into slices using a diamond wheel of 5″ × 0.15″ × 0.5 . Each slice was polished using silicon carbide grinding paper (macro-cut 180/p180 grit followed by micro-cut 1200/p2500 grit), then zirconia was sintered at 1550 °C for 2 h and Lithium disilicate was crystallized by firing at 770 °C for 5 min followed by firing at 850 °C for 10 min according to the manufacturer’s recommendations. The dimensions of the resultant slice were verified with a digital caliper.n = 10 per group) as follows: group 1 (LiDi/LC): lithium disilicate luted by light-cure resin cement; group 2 (LiDi/DC): lithium disilicate luted by dual-cure resin cement; group 3 (Zr/LC): zirconia luted by light-cure resin cement; and group 4 (Zr/DC): zirconia luted by dual-cure resin cement. Specimens were stored in normal saline in a covered container at room temperature for 24 h before color measurement.The ceramic slices were luted to the dentin surface of extracted teeth using either light-cure resin cement  or dual-cure resin cement . The materials used in this study and luting technique are described in Tables All specimens were subjected to 3000 thermal cycles between 5 and 50 °C using a thermocycler machine (JULABO GmbH) with immersion time of 15 s in each bath.ΔE = [(ΔL)2 + (Δa)2 + (Δb)2]1/2, where ΔE = color change; Δ = lightness difference (L*) such that the greater the L*, the higher the brightness of the sample; Δa = the a* axis difference such that the higher the a*, the redder the sample and the lower the a*, the greener the sample; and Δb = the b* axis difference such that the higher the b*, the yellower the sample and the lower the b*, the bluer the sample. ΔL = L*F − L*I; Δa = a*F − a*I; Δb = b*F − b*I, where L*I, a*I, and b*I represent the initial color measurement and L*F, a*F, and b*F represent the final color measurement.Color measurements of the specimens were performed before and after thermocycling by means of spectrophotometry (X-Rite). The CIE L*a*b* values of the specimens were measured according to the color change formula: ΔE values for each study group. The confidence level was set as 95%. Data were expressed as mean ± standard deviation. Comparison was performed using SPSS version 20.0 for Windows. p < 0.05 was considered statistically significant.The Shapiro–Wilk test was used to test data for normal distribution. Parametric statistical tests were then performed. These were the paired t-test on individual L*, a*, and b* variables before and after thermocycling, two-way ANOVA on individual L*, a*, and b* variables for each test group, and one-way ANOVA to compare ΔE), are presented in Table ΔE) found in this study was 3.59 ± 1.60. All groups showed a normal distribution of data with the Shapiro–Wilk test (p > 0.05) except for the color change in the Zr/LC group (p = 0.031).For each study group, the mean and standard deviations of the color coordinates before and after thermocycling, and of the change in color (p < 0.05), redder (p < 0.05), and more yellow (p < 0.05) after 3000 thermal cycles  so that brightness was significantly higher for zirconia (66.21 ± 2.45) than for lithium disilicate (58.99 ± 2.14). The main effect of cement type was non-significant (p > 0.05). However, the interaction effect was significant (p < 0.05) indicating that ceramic type effect was greater with dual-cure cement than with light-cure cement for zirconia and greater with light-cure than dual-cure for lithium disilicate. Similarly, analysis for the a* value revealed a main effect for the ceramic type (p < 0.05) suggesting that redness was significantly higher for lithium disilicate (− 0.72 ± 0.06) than for zirconia (− 1.52 ± 0.06). However, the main effect of cement type and ceramic/cement interaction on the a* value were non-significant (p > 0.05). The two-way ANOVA test for the b* value showed a main effect for the cement type (p < 0.05). Therefore, yellowness was significantly higher for dual-cure resin cement (5.2 ± 0.3) than for light-cure resin cement (4.2 ± 0.3). The main effect of ceramic type or ceramic/cement interaction on the b* value was non-significant (p > 0.05).A two-way analysis of variance for the L* value showed a main effect for the ceramic type (ΔE) values between all tested groups (p = 0.756)  Table ; Fig. 2.The current study utilized spectrophotometer to measure color coordinates of specimens. Color in dentistry can be evaluated using visual and/or instrumental methods. Although the visual method is subjective, it was the base for development of all color measuring instruments and it should complement their use. Instruments for color coordinate measurement include; spectrophotometer, colorimeters, and digital imaging systems. Spectrophotometer is considered one of the most accurate instruments for color measurement in dentistry. It measures the amount of light reflected from an object. This reflectance value is converted to shade tab equivalent. Colorimeter on the other hand is less accurate than spectrophotometer. It formulates color by filtering light in red, green, and blue areas of the visible spectrum. Additionally, digital cameras create a color image by acquiring red, green, and blue image information whereas software systems can compare shade in digital images with known reference shade .. study [The results of this study indicated that the color stabilities of the ceramic materials under the current investigation are comparable regardless of the type of luting cement used. Therefore, we failed to reject the null hypothesis. The current sample size was based on the reported mean and standard deviation of mean color change value among lithium disilicate, monolithic zirconia, and bilayer zirconia in Haralur et al. study  assumingThermocycling resulted in a change in the color coordinates of all tested specimens. An increase in the L*, a*, and b* values indicates an increase in the brightness, redness, and yellowness of the specimen after cyclic aging, respectively. A change in the color of luted dental ceramics as a result of aging was reported in many previous studies , 10, 11.ΔE = 1 and a threshold of acceptability of ΔE = 3.7 as concluded in a review by Khashayar et al. [ΔE = 3.99 ± 1.83).The overall mean color change value found in this study was 3.59 ± 1.6. The color difference is proposed to be perceptible when it can be detected by the human eye, and acceptable when it is tolerable . Consider et al. , the colp = 0.756). Consistent with our findings, Subaci et al. [In our study, the color change values for specimens of IPS e.max CAD and Katana Zirconia STML were not significantly different (i et al.  reportedi et al. , 21. In i et al. . In anoti et al. , the prei et al. . This abIn the present investigation, the brightness was significantly higher for zirconia samples than for lithium disilicate samples, due to ceramic type effect. The increased brightness of zirconia may be related to its higher refractive index, inducing more scattering of the light passing through, and to its lower translucency than lithium disilicate –25.Additionally, the present study demonstrated that samples luted with dual-cure resin cement were significantly more yellow than samples luted using light-cure resin cement. The main contributor to this difference was the cement type. Consistent with our finding, several previous studies reported that dual-cure resin cement is more yellow than light-cure resin cement upon polymerization . This waThe results of the present study could have been enhanced by performing measurements of the substrate color coordinate and specimens transparency parameter, in addition to increasing the current sample size and number of thermal cycles. Further studies should be conducted on the optical and mechanical properties of the high-translucency ceramic materials to delineate their recommended clinical situations.Thermocycling resulted in a significant change in the color coordinates of all tested specimens.The overall mean color change value found in this study was considered within the clinically acceptable level.At 1 mm restoration thickness, the color stabilities of high translucency monolithic lithium disilicate and high-translucency zirconia ceramics were not significantly different, regardless of the cement type used.Within the limitations of this in vitro study, the following conclusions could be drawn: