Segment Thickness Research Articles

The prospective sonographic assessment of the lower uterine segment after cesarean section and its clinical utility.

This study aims to investigate the sonographic features of the lower uterine segment (LUS) and their association with successful vaginal birth after a cesarean section (VBAC). This is a prospective observational cohort study of women who underwent a first cesarean section (CS). Inclusion criteria were age over 18years and open family planning. Women with a history of any additional uterine surgery, as well as a vertical or inverted T uterotomy during the CS were excluded. A pregestational transvaginal sonography, followed by serial transabdominal ultrasound examinations at the first, second, and third trimesters upon starting a new pregnancy were performed. Each intra-gestational examination involved measuring the LUS on a sagittal plane over a length of 3cm starting from the most inferior identifiable part of the myometrium behind a full bladder. Logistic regression was performed to test the association between measures of the LUS and successful vaginal birth after CS. 96 women with a follow-up pregnancy within 2years of the initial CS were included in the analysis. The pregestational RMT ratio was 62% and 38 (39%) women had a niche. The median thickness of the lower uterine segment was 8.34mm (5.57-9.77), 4.75mm (4.02-5.95), and 2.55mm (2.01-3.55) at the first, second and third trimester, respectively. 70 women attempted VBAC and the risk of unplanned repeat CS was 37.1%. One millimeter increase in LUS thickness in the first trimester increased the odds of VBAC by 50-120% depending on the used measure (p < 0.05). This association weakened with increasing gestational age and the p values increased above 0.05. There is a good chance of successful VBAC for women attempting it. The sonographic assessment of the lower uterine segment during pregnancy could be helpful in counseling these women, albeit it seems that performing ultrasound during the first trimester is more informative than second and third trimesters.

Application Value of Myocardial Segmental Thickness Variability Measured by Echocardiography in Distinguishing Ischemic and Nonischemic Dilated Cardiomyopathy.

The aim of this study is to evaluate the clinical value of myocardial segmental thickness variability (STV) measured by echocardiography in distinguishing ischemic cardiomyopathy (ICM) from nonischemic dilated cardiomyopathy (NIDCM). This study included 120 patients diagnosed with dilated cardiomyopathy, divided into ICM (n = 43) and NIDCM (n = 77) groups based on coronary angiography. Traditional echocardiographic parameters, STV, and regional wall motion abnormalities (RWMA) were compared. The diagnostic value of STV was assessed using receiver operating characteristic (ROC) curve analysis. There were no significant differences in traditional echocardiographic parameters between the groups. The NIDCM group had a significantly higher mean STV compared to the ICM group. An STV threshold of 0.768 provided a sensitivity of 86.0% and a specificity of 94.8% for distinguishing ICM from NIDCM. Combining STV with RWMA improved diagnostic accuracy. STV measured by echocardiography is a valuable, noninvasive tool for differentiating between ICM and NIDCM, offering high sensitivity and specificity. This approach enhances diagnostic precision, supporting its use in clinical practice to guide appropriate treatment strategies.

Hennegoides Africanus sp. nov. from Kadey River in Cameroon.

Fish are susceptible to various parasitic infections, with Myxozoa emerging as a major group. A taxonomic study of Myxozoa is essential for the rapid diagnosis of species potentially responsible for epizootic diseases. The studied fish was collected from the Kadey River, a tributary of the Sangha River in the Congo Basin in Cameroon, and parasitologically dissected. Cysts from gill samples were examined morphologically and molecularly to assess myxozoan diversity and phylogenetic relationships were determined based on SSU rDNA. Infection by Hennegoides africanus sp. nov., found in gill filaments of 60% of C. gibbosus. Infection characterized as intrafilamental-epithelial type. Myxospore body vaulted on one side, measured 13.5 (12.4-14.8) × 2.1 (1.9-2.5) µm. Caudal appendages measured 31.3 (25.4-34.93) µm, made of thick and filamentous segments. Two polar capsules elongated, differing in size and position; smaller capsule near anterior end measured 2.8 (2.18-3.54) × 0.9 (0.7-1.1) µm, while larger, located posteriorly, measured 3.8 (3.21-4.45) × 1.4 (1.2-1.7) µm. The SSU rDNA gene sequence of Hennegoides africanus sp. nov. does not match any sequences in GenBank and is closely associated with two undetermined species of Henneguya and Myxobolus infecting the gills of Characiformes in Africa. Morpho-molecular evidence indicates that Hennegoides africanus sp. nov. is a new species to science and the first reported member of its genus in Africa.

DOP083 «Sonorescue»-treatment response in acute severe Ulcerative Colitis measured with ultrasound

Abstract Background First line medical treatment in acute severe ulcerative colitis (ASUC) is intravenous corticosteroids. Patients with insufficient response receives rescue treatment. The decision is made by the treating physician and is based on disease severity and improvement in stool frequency, rectal bleeding, biochemical parameters, and general well-being. Gastrointestinal ultrasound (GIUS) can be used to find the degree of inflammation in ulcerative colitis, but can it be used to detect the lack of treatment response in ASUC? Methods Patients with ASUC were included from June 2020 to Nov 2024 at two hospitals in Bergen, Norway. They were examined with GIUS prior to treatment with iv corticosteroids and after 2-3 days of treatment. Patients with a normal GIUS, endoscopic MAYO&amp;lt;2 or isolated proctitis were excluded. Bowel wall thickness, bowel wall vessel density with colour Doppler, loss of haustration and fatty tissue reaction was registered for every segment of the colon as well as an activity score based on these parameters1. The two main outcomes of the study were the clinical decision to give rescue with infliximab and Lindgren’s criteria for the risk of colectomy2. Results In total 33/64 patients received rescue treatment. In the sigmoid colon the wall was 4.3±1,3 mm in patients receiving rescue treatment and 2.5±1mm in the others (p&amp;lt;0.001). There was also a significant difference in vessel density, haustrations, and fatty tissue reaction. Furthermore, there were significant differences for wall thickness in all the other colon segments including the sum of these measurements. The full score based on all parameters was 15.2±5,2 vs 8.3±5,3 (p&amp;lt;0.001). The areas under the receiver operating curve (AUROC) for wall thickness in the sigmoid colon, total bowel wall thickness and the activity score were 0.87 (0.79-0.96), 0.84 (0.75-0.94) and 0.84 (0.74-0.94), respectively. According to Lindgren’s Criteria 23/64 had a high risk for colectomy. AUROCs for the same parameters were 0.86(0.75-0.96), 0.88(0.80-0.97) and 0.85 (0.76-0.94), respectively. If a low risk of colectomy is required a total bowel wall thickness ≥ 9mm at day 2-3 predicts the risk of colectomy with 100% sensitivity and 50% specificity. For the single measurement in the sigmoid colon and a corresponding sensitivity of 96% (cut off 2.4 mm) the specificity will wall fall to 32.5%. Conclusion GIUS can be used to detect insufficient treatment response in ASUC already after 2-3 days of intravenous corticosteroids which confirms previous findings3. A single measurement in the sigmoid colon could be sufficient, but the combined sum of bowel wall thickness in all colon segments could be better for selecting patients that should get rescue treatment.

Sonographic Lower Uterine Segment Thickness after Prior Cesarean Section to Predict Uterine Rupture

Introduction: Uterine rupture occurs in many pregnancies. The risk is higher for women who plan to have a normal birth after a previous cesarean section than for those who have another cesarean section. Objectives: This study aimed to predict the thickness of the lower uterine segment (LUS) by comparing a 2D transvaginal ultrasound with the findings during a cesarean section (C/S) in pregnant women with a history of previous cesarean sections. Methodology: This cross-sectional study was done at the Department of Obstetrics and Gynaecology, at the Institute of Child and Mother Health, Bangladesh from June 2023 to May 2024. A well-structured questionnaire was used for data collection. 100 women underwent transvaginal ultrasound followed by cesarean section (C/S) within a maximum of one week later. Also, an expert gynaecologist classified LUS thickness into four grades in the operation room. Result: The mean age of the women in the study was 30.7 years (±9.62), while the mean thickness of the lower uterine segment (LUS) was 2.25 cm (± 0.55). Among the participants, 43 were classified as grade I for the LUS based on intraoperative findings. The results indicated a significant difference in the mean thickness of the LUS measured by ultrasound across the three grades identified by the gynaecologist (P = 0.04). However, there were no significant differences in maternal age, gestational age, parity, or the time since the last cesarean section among women with different LUS grades (P &gt; 0.05). Transvaginal ultrasound may be useful in assessing the risk of scar dehiscence and uterine rupture in women with LUS grades I and II who have a history of previous cesarean sections. Conclusion: Sonographic lower uterine segment thickness prediction is very important in the study of lower uterine segment thickness after a prior cesarean section to predict uterine rupture. 2D vaginal ultrasonography can be used to assess the risk of uterine scar dehiscence of grades I and II.

Quantifying knee-adjacent subcutaneous fat in the entire OAI baseline dataset - Associations with cartilage MRI T2, thickness and pain, independent of BMI.

Knee-adjacent subcutaneous fat (kaSCF) has emerged as a potential biomarker and risk factor for osteoarthritis (OA) progression. This study aims to develop an AI-based tool for the automatic segmentation of kaSCF thickness and evaluate the cross-sectional associations between kaSCF, cartilage thickness, MRI-based cartilage T2 relaxation time, knee pain, and muscle strength independent of BMI. Baseline 3.0T MR images of the right knee from the entire Osteoarthritis Initiative cohort (n=4796) were used to quantify average values of kaSCF, cartilage thickness, and T2 using deep learning algorithms. Regression models (adjusted for age, gender, BMI, and race) were used to evaluate the associations between standardized kaSCF and outcomes of cartilage thickness, T2, pain, and knee extension strength. Model prediction CVs for kaSCF thickness ranged from 3.57% to 9.87% across femoral and tibial regions. Greater average kaSCF was associated with thinner cartilage in men (std. β= -0.029, 95% CI: -0.050 to -0.007, p=0.010) and higher T2 in women (std. β=0.169, 95% CI: 0.072 to 0.265, p=0.001). Greater kaSCF was also associated with lower knee extension force (std. β= -15.36, 95% CI: -20.39 to -10.33, p<0.001) and higher odds of frequent knee pain (std. odds ratio=1.156, 95% CI: 1.046 to 1.278, p=0.005) across all participants. Greater kaSCF was associated with thinner cartilage in men, higher T2 in women, reduced knee strength, and greater knee pain, independent of BMI. These findings suggest a potential role of kaSCF as a predictor for KOA-related structural, functional, and clinical outcomes independent of the effects of BMI.

Predictive risk scores for visual prognosis after photodynamic therapy for central serous chorioretinopathy.

To comprehensively evaluate baseline characteristics of patients with central serous chorioretinopathy (CSC) and develop predictive risk scores to identify visual prognosis. This single-institute, retrospective cohort study included 144 eyes of 144 patients with CSC who underwent photodynamic therapy and achieved serous retinal detachment resolution. We developed and assessed the performance of several risk scores for best-corrected visual acuity (BCVA) outcomes six months post-treatment: i) BCVA improvement (≤-1.0 logMAR), and ii) BCVA deterioration (≥+ 1.0 logMAR). The BCVA improvement models used photoreceptor outer segment thickness, loss of photoreceptor outer segment, and neurosensory retinal thickness (NSRT), while the BCVA deterioration models included outer nuclear layer thickness and NSRT. The BCVA improvement models demonstrated a corrected area under the curve (AUC) of 0.786 (95% confidence interval [CI]: 0.699-0.864), with 80.4% sensitivity, and 71.2% specificity. The BCVA deterioration models achieved a corrected AUC of 0.864 (95% CI: 0.742-0.958), with 85.7% sensitivity, and 83.5% specificity. The predictive models for CSC exhibited favorable performance in predicting individual visual prognoses. A thinner outer nuclear layer may be associated with BCVA deterioration, whereas preservation of the photoreceptor outer segment may be correlated with BCVA improvement. WHAT IS KNOWN : Pre-treatment best-corrected visual acuity, thickness of each sensory retinal layer, time fromonset to treatment, and macular atrophy were each found to be associated with visualprognosis for patients with central serous chorioretinopathy (CSC). The current study comprehensively assessed potential prognostic factors and precisely identified individual likelihood of visual prognosis. The study found that different regions of the sensory retina were associated with either worsening or improving visual acuity. Accurately predicting visual outcomes after photodynamic therapy for CSC would help healthcare providers create personalized treatment plans and enable patients to make informed decisions about their treatment based on their expected visual results.

Lower uterine segment thickness to predict uterine rupture: a secondary analysis of PRISMA cluster randomized trial

BackgroundThird-trimester lower uterine segment thickness (LUST) is associated with uterine rupture during trial of labor after cesarean (TOLAC) but threshold values vary according to the approach used (lower values with vaginal ultrasound, higher values with abdominal ultrasound). ObjectiveTo estimate the optimal LUST cut-off value combining vaginal and abdominal ultrasound to predict uterine rupture during TOLAC. Study DesignWe performed a secondary analysis of PRISMA cluster randomized trial including women with a single previous cesarean who underwent ultrasound LUST measurement at 34–38 weeks using the thinnest measurement obtained by combining transvaginal and transabdominal measurements. Participants in the intervention group were informed about the risk of uterine rupture according to LUST reported in 3 categories (≥2.5 mm: low risk—TOLAC is safe; 2.0–2.4 mm: intermediate-risk—TOLAC is safe under specific conditions (e.g., Grobman estimate of vaginal delivery of at or above 70% and/or having a history of vaginal delivery; estimated fetal weight below 4000 grams; interdelivery interval≥18 months); <2.0 mm: high-risk for uterine rupture). Delivery outcomes including uterine rupture were compared using nonparametric analyses and receiver operating characteristics (ROC) curves. ResultsAmong 3460 participants, 2809 (81%); 385 (11%); and 266 (8%) were identified at low-; intermediate-; and high-risk for uterine rupture, respectively. As expected, low-risk participants were more likely to undergo TOLAC (49% vs 46% vs 13%; P=.001) and more likely to undergo labor induction (16% vs 12% vs 3%, respectively; P=.001) than intermediate-risk and high-risk participants. Four (0.3%) cases of uterine rupture during TOLAC occurred among 1382 low-risk participants but none among the intermediate-risk (0/178) and high-risk (0/35) participants (P=.73). Among low-risk participants, uterine rupture was associated with LUST combining vaginal and abdominal ultrasound (area under the ROC curve: 0.93; 95% confidence interval: 0.86%–0.99%; P=.001) with all cases occuring among women with LUST between 2.5 and 3.0 mm (4/371 or 1.1%) compared to none (0/1011) among those with LUST≥3.0 mm (P=.01). ConclusionsThird-trimester LUST measurement influences the rates of TOLAC and uterine rupture. TOLAC appears to be associated with a low risk of uterine rupture with a LUST between 2.0 and 2.4 mm under specific conditions. However, these conditions should perhaps be extended to patients with a LUST of less than 3.0 mm, as we found an increase in uterine ruptures in this subgroup (between 2.5 and 3.0 mm) who had no special conditions to comply with. LUST≥3.0 mm combining vaginal and abdominal ultrasound was associated with a very low risk for uterine rupture. A large-scale study using these new parameters would have the potential to demonstrate a reduction in uterine ruptures during TOLAC.

Corneal Allogenic Intrastromal Ring Segments (CAIRS) Versus Synthetic Segments: A Single Segment Comparative Analysis Using Propensity Score Matching.

To compare and assess the visual, refractive, and tomographic results of patients with corneal ectasia treated with either corneal allogenic intrastromal ring segments (CAIRS) or synthetic intrastromal corneal ring segments (ICRS) without concomitant corneal cross-linking. In this retrospective cohort study, 34 eyes with CAIRS were matched to 34 eyes with ICRS using the propensity score matching technique. Each group was matched on a oneto-one basis using multiple parameters such as central corneal thickness, vertical and horizontal coma, maximum anterior keratometry, steepest keratometry, and age. Visual, refractive, topographic, and aberrometric data were measured at baseline, 1 week, 1 month, 3 months, and 1 year postoperatively. Initial preoperative parameters were similar between the two groups. Both groups showed significant improvement at last follow-up time in corrected distance visual acuity (CDVA) (0.52 ± 0.23 to 0.16 ± 0.18 logarithm of the minimum angle of resolution [logMAR], P < .001; 0.44 ± 0.27 to 0.17 ± 0.21 logMAR, P < .001), topographic astigmatism (4.45 ± 2.75 to 3.14 ± 1.93 diopters [D], P = .001; 3.66 ± 2.22 to 2.36 ± 1.46 D, P = .007), maximum anterior keratometry (55.85 ± 7.53 to 50.69 ± 6.38 D, P < .001; 54.59 ± 6.95 to 50.71 ± 4.51 D, P = .003), and vertical coma (1.49 ± 1.02 to 0.38 ± 0.65 D, P < .001; 1.22 ± 0.75 to 0.52 ± 0.57 D, P < .001) for CAIRS and ICRS, respectively. The improvements observed in both groups at the last follow-up visit were comparable; however, the CAIRS group demonstrated a higher percentage of eyes gaining two or more Snellen lines of CDVA (60% vs 31.58%, P = .04), and a greater magnitude of reduction in vertical coma compared to the ICRS group, although this difference did not reach statistical significance. No major complications were observed with both groups, and one eye lost one CDVA line in the ICRS group. The mean thickness of the CAIRS segments at the last follow-up visit was 401.06 ± 100.12 µm, compared to 435.29 ± 26.19 µm for ICRS. Both CAIRS and ICRS demonstrated significant compression of stromal thickness above the segment (36.19% and 32.00%, respectively). When adequately matched for preoperative disease type and severity, eyes with CAIRS had a similar and notable clinical improvement compared to ICRS, with possibly better improvement in vertical coma and CDVA. [J Refract Surg. 2024;40(11):e863-e876.].

Influence of peak exercise-induced blood pressure on basal to apical myocardial wall thickness in elite athletes: a sex-specific CMR study

Abstract Background Understanding the sex-specific physiological remodelling response of the myocardial walls to peak exercise-induced blood pressure (SBPpeak) is essential for distinguishing healthy adaptation from pathological remodelling in athletes. Purpose We investigated how SBPpeak relates to myocardial wall thickness measured using cardiac magnetic resonance imaging (CMR) in elite athletes. Methods Cross-sectional analysis of healthy elite athletes included in the ELITE study who underwent both cardiopulmonary exercise testing (CPET) and CMR. Imaging software’s built-in AI option determined average end-diastolic wall thicknesses of all sixteen AHA-defined segments on short-axis cine images with four-chamber long-axis reference. Our primary metrics of interest were Spearman's correlations between SBPpeak and left ventricular mass indexed to body surface area (LVM/BSA), as well as average wall thickness across the sixteen myocardial segments, stratified by sex and endurance/non-endurance sports status. Secondary analyses involved regression models to evaluate the influence of SBPpeak on myocardial wall thickness, adjusting for sex, body size, CPET variables and sport type. Results In 75 athletes (median age: 24; 71% female; 61% engaged in endurance sports), CPET and CMR were performed within a median interval of 5 months [interquartile range: 1-13 months]. SBPpeak was similar in female and male athletes (170 [160-180] vs. 174 [169-184] mmHg, p=0.121, respectively) and in endurance and non-endurance athletes (both 170 [160-180] mmHg, p=0.625). Female elite athletes showed weak to moderate positive correlations between SBPpeak and the majority of basal and mid-ventricular AHA segments (rho = 0.27 – 0.48, Figure). This was most pronounced in the mid-ventricular anterolateral segment (AHA06: rho = 0.48, p&amp;lt;0.001). LVM/BSA in females was positively correlated with SBPpeak (rho = 0.31, p=0.025). Male elite athletes demonstrated greater absolute wall thickness across all AHA segments compared to females, however, there was a moderate correlation with SBPpeak exclusive to the basal anterior segment (AHA01: rho = 0.48, p=0.028). Backward stepwise multivariate regression analyses (Table) revealed SBPpeak as an independent predictor of the thickness of all basal AHA segments except for the basal inferoseptal segment (AHA03), and the mid-anterior and anterolateral segments. Associationswere maintained after adjustment for maximum wattage, body surface area, and sex, with type of sports consistently excluded from the models. Conclusion In the extreme phenotypes of elite athletes, SBPpeak correlates especially with basal myocardial thickness, independent of sex, BSA and maximum work rate influences. We found stronger associations between SBPpeak and myocardial adaptation in female athletes. These findings suggest a paramount role of exercise-induced blood pressure on basal myocardial remodelling surpassing the effect of sports type.Figure:segmental polar plot (heat map)Table:GAM regression models

The role of the lower uterine segment thickness in predicting preterm birth in twin pregnancies presenting with threatened preterm labor.

To examine the relationship between the lower uterine segment (LUS) thickness and the onset of labor in dichorionic twin pregnancies experiencing threatened preterm labor. This prospective cohort study included dichorionic twin pregnancies between 24 and 32weeks of gestation, presenting with symptoms of preterm labor. The LUS thickness and mid-anterior wall thickness were measured via transabdominal ultrasonography, cervical length, and posterior cervical lip thickness were measured transvaginally. The presence of the cervical sliding sign and funneling findings were recorded. Among the patients with an onset of labor before the 34th week, the mean LUS thickness was 3.8±0.9 mm, compared to 4.6±1.1 mm in those with an onset of labor at or after 340/7 GW, indicating a statistically significant difference (p=0.012). Similarly, accepting the GW threshold as 350/7 weeks, a statistically significant difference was found in the mean LUS thickness, which was 4.0±1.0 mm in those with an earlier onset of labor and 4.7±1.0 mm in those with a later onset of labor (p=0.022). While univariate analysis indicated that the LUS thickness was a significant predictor (p=0.017 for <34 GW and p=0.028 for <35 GW), multivariate analysis showed a reduced effect (p=0.04 and p=0.06, respectively). LUS was significantly thinner in pregnancies with an onset of labor before the 34th and 35th GW. The measurement of the LUS thickness can be considered an alternative method for predicting spontaneous preterm birth in dichorionic twin pregnancies.

Crosslinked All-Femtosecond Laser-Cut Corneal Allogenic Intracorneal Ring Segments (AFXL CAIRSs): Pilot Ex Vivo Study and Report of First Two Cases Performed in Italy.

Objectives: This pilot ex vivo study and first clinical experience in Italy evaluate the impact of using pre-implantation crosslinking on all-femtosecond laser-cut corneal allogenic intracorneal ring segments (AFXL CAIRSs). Methods: Six human donor eye-bank corneas were used for this preclinical ex vivo human study. Three donor (D) corneas were used for AFXL CAIRSs. First, they were prepared with an IntraLase™ femtosecond laser (Johnson & Johnson, New Brunswick, NJ, USA). The allogenic tissue rings were crosslinked before implantation with Riboflavin-UV-A accelerated crosslinking protocol (ACXL) with a 0.1% HPMC Riboflavin isotonic solution (Vibex Rapid, Glaukos-Avedro, Burlington, MA, USA) and a new KXL UV-A emitter (Glaukos-Avedro, USA). Three corneas were used as recipients (Rs) of the AFXL CAIRSs. After completing the ex vivo phase, IRB approval and signing a specific informed consent, the first two Italian patients were treated. A single ACXL CAIRS was implanted in a 51-year-old male with 53.53 D K steep, 363 μm minimum corneal thickness (MCT) and a double ACXL CAIRS was implanted in a 46-year-old male patient with 58.30 D K steep, 443 μm MCT. The longest follow-up was at three months. Results: Crosslinking of the segments enhanced tissue stiffness and grip, facilitating manipulation and CAIRS insertion into the recipient tunnels, and the yellowish color of the crosslinked segments improved visibility. The segment's thickness and volume remained unaltered during the follow-up. Both patients improved UDVA and BSCVA. K steep and High-Order Aberrations (HOAs) were reduced and MCT increased. Conclusions: Pre-implantation ACXL facilitated CAIRS insertion preserving dimensions and volume during the follow-up, rendering this important step a promising candidate in method standardization. Functional data and MCT improved significantly without adverse events.

Investigation on shear performance of sliding-type rapid segmental joints for shield tunnels

This paper introduces a sliding-type rapid joint and investigates the joint's failure modes under compression-shear loading with a combination of numerical and experimental methods. The study analyzes the influence of axial force, arrangement methods, and segment thickness on the joint's shear resistance. Additionally, a detailed examination of stress distribution within the joints provides a deeper understanding of their mechanical behavior. The results reveal that four-stage exists in the shear-dislocation curve of joints, including static frictional stage, partial sliding stage, overall sliding stage, and descending stage. Increasing axial force enhances the joint's shear resistance, but excessively high axial forces raise the risk of shear failure in T-shaped components. Under the trans-arrangement, the sliding-type rapid segmental joint exhibits superior shear resistance, especially under high axial loads. The material strength of C-shaped components impacts the joint's shear resistance, and increasing segment thickness enhances the joint's shear resistance. Under reverse-radial shear conditions, the structure's shear capacity is not solely determined by the joint strength. Tangential shear occurs during the assembly process, emphasizing the need to avoid excessive assembly forces. The junction between the T-shaped structure and the joint panel is a vulnerable point for T-shaped components, and reinforcement by increasing size and thickness can prevent shear failure at this location.

Multi-objective optimization of L-shaped fins in rectangular phase change energy storage units based on genetic algorithm

Phase change energy storage technology holds immense potential in the field of energy storage, and enhancing the efficiency of energy storage systems has long been a focal point of industry attention. This study aims to optimize the design of an L-shaped fin structure to improve the melting rate of the phase change material (PCM) within a rectangular phase change energy storage unit and enhance the overall system performance. Through the utilization of numerical simulations and the response surface method (RSM), the influence of fin design parameters - specifically, the length and thickness of the main segment and the length and thickness of the branch segment - on the energy storage per unit mass (Em) and energy storage efficiency (Pt) of the energy storage unit is evaluated. The results reveal that the length of both the main and branch segments of the L-shaped fin significantly impacts the melting rate of the PCM, whereas the thickness of these segments has a comparatively lesser effect. Additionally, when the length of the main segment reaches a sufficient value, increasing the length of the branch segment effectively addresses the challenge of PCM melting difficulties at the bottom of the rectangular phase change cavity caused by natural convection. The Non-Dominated Sorting Genetic Algorithm-II (NSGA-II) is employed for the multi-objective optimization of the L-shaped fin shape, and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) with entropy weighting is applied for decision-making to determine the optimal solution. Notably, when the weights of Em and Pt are set at 44.9 % and 55.1 % respectively, the overall performance of the energy storage unit is optimized. The Pareto-optimal decision solution exhibits a significant improvement of nearly threefold in Pt compared to the case without fins, while the reduction in Em is only 5.24 %. This design approach presents a novel perspective for determining fin parameters in phase change energy storage devices and is expected to drive advancements in phase change energy storage technology.

Optical coherence tomography assessment of the impact of colchicine on non-culprit coronary plaque composition after myocardial infarction.

Low-dose colchicine reduces the risk of cardiovascular events after myocardial infarction (MI). The purpose of this study was to assess the effect of colchicine post-MI on coronary plaque morphology in non-culprit segments by optical coherence tomography (OCT). COCOMO-ACS was a double-blind, placebo-controlled trial that randomized 64 patients (median age 61.5 years; 9.4% female) with acute non-ST-segment elevation MI to colchicine 0.5 mg daily or placebo for a median of 17.8 months in addition to guideline-recommended therapy. Participants underwent serial OCT imaging within a matched segment of non-culprit coronary artery which contained at least one lipid-rich plaque causing ≥20% stenosis. The primary outcome was the change in minimum fibrous cap thickness (FCT) in non-culprit segments from baseline to final visit. Of those randomized, 57 (29 placebo, 28 colchicine) had evaluable imaging at baseline and follow-up. Overall, colchicine had no effect on relative (placebo +48.0±35.1% vs. colchicine +62.4±38.1%, P=0.18) or absolute changes in minimum FCT (+29.2±20.9 µm vs. +37.2±21.3 µm, P=0.18), or change in maximum lipid arc (-38.8±32.2° vs. -54.8±46.9°, P=0.18) throughout the imaged non-culprit segment. However, in patients assigned colchicine, cap rupture was less frequent (placebo 27.6% vs. colchicine 3.6%, P=0.03). In post-hoc analysis of 43 participants who had been followed for at least 16 months, minimum FCT increased to a greater extent in the colchicine group (placebo +38.7±25.4% vs. colchicine +64.7±34.1%, P=0.005). In this study, OCT failed to detect an effect of colchicine on the minimum FCT or maximum lipid arc of plaques in non-culprit segments post-MI. The post-hoc observation that minimum FCT increased to a greater extent with colchicine after more prolonged treatment suggests longer-term studies may be required to detect the effect of anti-inflammatory therapies on plaque morphology by OCT. Australian New Zealand Clinical Trials Registry Identifier, ACTRN12618000809235, registered on the 11th of May 2018.

The Role of Lower Uterine Segment Thickness in Predicting Cesarean Scar Defects: Two-Dimensional Transvaginal Ultrasound Vs. Intraoperative Findings

The Role of Lower Uterine Segment Thickness in Predicting Cesarean Scar Defects: Two-Dimensional Transvaginal Ultrasound Vs. Intraoperative Findings

Immunohistochemical and Ultrastructural Characterization of Telocytes in Normal and Diabetic Human Kidneys.

Background: Telocytes are interstitial stromal cells identified in various human organs, including the kidney. Their presence and role in human diabetic kidney disease remain unknown. Methods: To identify and localize telocytes in glomerular and tubule-interstitial compartments, both normal and diabetic human renal tissues were examined using immunohistochemistry, immunofluorescence, and transmission electron microscopy. Results: Renal telocytes are elongated interstitial cells with long, thin telopodes, showing alternating thin and thick segments. They expressed CD34, Nestin, α-SMA, and Vimentin markers. Occasionally, c-Kit expression was observed in some rounded and spindle cells, while no positivity was detected for PDGFR-β and NG2. Telocytes were identified around Bowman's capsule, tubules, and peritubular capillaries in both normal and diabetic conditions. In diabetic renal samples, there was a significant increase in α-SMA expressing telocytes, leading to periglomerular fibrosis. These telocytes also exhibited a synthetic phenotype with proteoglycan deposition in the extracellular matrix and, in some cases, showed pre-adipocytic differentiation. Conclusions: Telocytes were identified in normal and diabetic human kidneys. These cells form an elastic mechanical scaffold in the interstitium and are present in all renal cortical compartments. In diabetic samples, their increased α-SMA expression and synthetic phenotype suggest their potential role in the pathogenesis of diabetic nephropathy.

CD34+stromal cells/telocytes and their role in mouse lung development: Light microscopy, immunofluorescence, ultrastructural and scanning electron microscopy evidence.

Telocytes (TCs), a novel type of mesenchymal or interstitial cell with specific, very long and thin cellular prolongations, have been found in various mammalian organs and have potential biological functions. However, their existence during lung development is poorly understood. This study aimed to investigate the existence, morphological features, and role of CD34+ SCs/TCs in mouse lungs from foetal to postnatal life using primary cell culture, double immunofluorescence, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The immunofluorescence double staining profiles revealed positive expression of CD34 and PDGFR-α, Sca-1 or VEGFR-3, and the expression of these markers differed among the age groups during lung development. Intriguingly, in the E18.5 stage of development, along with the CD34+ SCs/TCs, haematopoietic stem cells and angiogenic factors were also significantly increased in number compared with those in the E14.5, E16.5, P0 and P7. Subsequently, TEM confirmed that CD34+ SCs/TCs consisted of a small cell body with long telopodes (Tps) that projected from the cytoplasm. Tps consisted of alternating thin and thick segments known as podomers and podoms. TCs contain abundant endoplasmic reticulum, mitochondria and secretory vesicles and establish close connections with neighbouring cells. Furthermore, SEM revealed characteristic features, including triangular, oval, spherical, or fusiform cell bodies with extensive cellular prolongations, depending on the number of Tps. Our findings provide evidence for the existence of CD34+ SCs/TCs, which contribute to vasculogenesis, the formation of the air‒blood barrier, tissue organization during lung development and homoeostasis.

Thermal vibration analysis of bi-directionally stepped porous functionally graded plates with segment-specific material property variation supported by Kerr foundation

This paper presents a comprehensive analysis of the nonlinear dynamic response of stepped rectangular plates made of functionally graded porous material (FGPM), supported by the Kerr foundation, in a thermal environment. A novel analytical framework is developed to explore geometric and material variations. The study investigates structural variations in plate thickness with abrupt changes in uni- or bi-directional orientations, examining both single and double stepped thickness profiles. Material properties vary with thickness, featuring distinct horizontal discontinuities across plate segments. Porosity distributions, both even and uneven, are addressed using modified mixture rules. Nonlinear kinematic relationships are established using Reddy’s third-order shear deformation plate theory and von Kármán’s nonlinear geometric assumptions, with equations of motion solved via Galerkin’s technique. This improved model effectively addresses non-continuous thickness variation through integral calculus, enhancing computational efficiency. Validation is achieved by comparing outcomes with published literature and Finite Element Analysis (FEA). The study investigates the influence of material properties, elastic foundation, boundary conditions, and geometric parameters on the free vibration and nonlinear behaviors of the plates. Some of the key findings include: increasing the thickness of the stepped segment significantly heightens the fundamental frequency while reducing vibrational amplitudes; optimizing the location of the stepped segment directly impacts the plate’s fundamental frequency and vibrational amplitudes; and as the load factor increases, the difference between linear and nonlinear deflection becomes evident. Therefore, accurate FGPM stepped plate design requires incorporating nonlinear terms in the strain–displacement relationships. Suggestions for future model modifications are also discussed, contributing to advancements in structural design and analysis.

Insights into atypical segmental layer thicknesses and phase retardation in thick corneas using ultrahigh-resolution polarization-sensitive optical coherence tomography

BackgroundAccurately assessing corneal structural status is challenging when thickness deviates from the average. Polarization-sensitive optical coherence tomography (PS-OCT) measures tissue-specific polarization changes, providing additional contrast for accurate segmentations and aids in phase retardation (PR) measurements. Previous studies have shown PR's effectiveness in identifying sub-clinical keratoconus (KC) in asymmetric cases. Thus, this study aims to assess PR distribution in thick corneas with and without KC.MethodsIn this retrospective and cross-sectional study, 45 thick corneas from 30 Asian-Indian subjects, categorized into healthy (n = 26) and KC (n = 19) groups were analyzed. All eyes underwent standard clinical evaluations, tomographic assessments, and corneal biomechanics measurements. PR and individual layer thicknesses were measured using custom-designed ultrahigh-resolution PS-OCT. PR en-face maps were generated. Individual layer thicknesses and PR analysis was conducted across multiple zones, extending up to 8–10 mm in diameter. All eyes in the study had not undergone interventions, received topical medications, or had previous corneal disease history.ResultsSignificant differences were found in spherical and cylindrical powers, keratometry, pachymetry, and biomechanical indices (all P < 0.01). Thickness profiles from PS-OCT showed significant differences in the 4–8 mm zones only. Bowman's layer thickness significantly differed only in the central 2 mm zone (P = 0.02). The median PR values showed marginal differences in the central 2 mm zone (P = 0.0565). Additionally, there were significant differences observed in the 2–4 mm and 4–6 mm zones (P = 0.0274 and P = 0.0456, respectively). KC eyes exhibited an atypical PR distribution and corneal thinning, while normal eyes maintained a uniform Bowman’s layer thickness and PR maps with larger areas of higher PR.ConclusionThe study revealed distinctive PR distribution in thick corneas among healthy and KC groups. Using an ultrahigh-resolution PS-OCT the significance of Bowman's layer thickness in these groups was also emphasized. The study offered potential improvements in clinical diagnostics by enhancing our understanding of corneal structure and its altered function.