Leakage Rate Research Articles

New alternative colorectal anastomotic devices: A systematic review and meta-analysis.

Colorectal anastomotic devices have been used for nearly a century, with stapled anastomoses being the most common despite leak rates up to 20​%. This review aimed to evaluate newer alternative devices. A systematic review and meta-analysis of publications from the last decade were conducted, focusing on devices forming colorectal anastomoses, excluding those facilitating sutured or stapled anastomoses or designed to prevent leaks. Data from MEDLINE, Embase, Cochrane, and ClinicalTrials.gov were analysed. Eighteen studies (7 human, 10 animal, 1 ex-vivo) involving 955 anastomoses were included. Compression mechanisms were the most common. The pooled complication rate in human studies was 9.7​% (95​% CI: 4.3-15.2​%) with significant heterogeneity (I2​=​81.7​%). The leak rate after compression anastomoses was 3.3​% (95​% CI: 1.9-4.7​%) with no heterogeneity (I2​=​0​%). A novel device with transanal catheters allowed intraoperative and postoperative assessment. Outcomes are comparable to existing methods, with new technologies offering promising advancements.

Neutronic analysis of a lithium-cooled space nuclear reactor based on sliding reflector design

Abstract The sliding reflector control system is utilized for core power level regulation through neutron leakage, offering a simpler structure in comparison to the control drum and control rod systems, thus minimizing the mass of the space reactor. This paper presents a conceptual design of a small – scale homogeneous lithium-cooled space fast reactor based on the sliding reflector control system. In this study, accurate modeling of the radial subregion of the reflector block is achieved, and the influence mechanism of the leakage rate on the key parameters of core neutronics is quantitatively analyzed. By pulling down the sliding reflector layer until the core reaches the critical state, the designed core shows a negative reactivity temperature coefficient of −0.3083 pcm/K. Meanwhile, the peak value of the inhomogeneity coefficients for axial and radial neutron flux density distributions are 1.414 and 1.268, respectively, satisfying safety and economic requirements. The analysis indicates that changes in the neutron leakage rate directly impact the reactivity. Building upon these findings, three reflector arrangement schemes summarizing all possible sliding scenarios are proposed: the uplift sliding reflector, the down-sliding reflector, and the intermediate separating sliding reflector. The results of neutron calculations show that the down-sliding reflector has the largest adjustment accuracy, with reaching criticality when the axial leakage length reaches 2.85 cm. The uplift reflector produces the most uniform axial neutron flux density distribution, peaking at 1.341.

Analysis and Evaluation of Harvest Quality Effectiveness of Carrot Clamping and Conveying Device

China’s carrot planting area and total output rank first in the world, but China’s mechanized carrot harvesting level is relatively backward. There are many problems in the existing machine operation process, among which the problems of a high leakage rate and high damage rate are the main difficulties faced. In order to study this problem, a test platform composed of clamping and pulling devices and conveying devices is designed, and it can complete the experiments of clamping, pulling and conveying carrot plants and collecting carrot stalks at one time. During the test, the clamping speed was divided into four test levels: 0.40 m/s (T1), 0.85 m/s (T2), 1.30 m/s (T3), and control test (CK), and each test level was carried out three times at different forward speeds. Finally, the leakage rate and damage rate were statistically analyzed. The results show that the average damage rate of Xiahong2 is 6.13%, 3.53%, and 9.36% and that of Sanhong is 6.22%, 3.76%, and 9.88% under the clamping and conveying speeds of T1, T2, and T3 in two years. The average carrot missed-pulling rate of two consecutive years corresponding to two carrot varieties, Xiaohong2 and Sanhong, was 3.68% and 4.14%, respectively. The carrot missed-pulling rate of CK in the control group of two carrot varieties, Xiaohong2 and Sanhong, was high and stable at 96.2% to 97.5%. At the same time, T1, T2, and T3 had similar overall trends of high carrot leakage rates for two carrot varieties at different clamping and conveying speeds. This control experiment also proves that the experimental arrangement is scientific and accurate. The average carrot leakage rate of T1, T2, and T3 for Xiahong2 is 3.91%, 3.42%, and 6.22%, and that of T1, T2, and T3 for Sanhong is 4.06%. The research results can provide a theoretical basis and reference for the optimization and improvement of carrot clamping and conveying devices, and this research can provide a reference for how to reduce the harvest loss of carrot combine harvesters in China.

Design and testing of a posture-adjusting precision metering device for high-speed maize planting

IntroductionThis study introduces a new technical method that involves adjusting the seed-filling posture and fluidizing the seed group to improve the capacity of mechanical seed-metering devices for high-speed maize planting. The design of a novel posture-adjusting seed-metering device is presented and its operating principle is described. In the seed-filling area, the seeds maintain the same postural characteristics and are detached from the seed group. This method creates favorable conditions for mechanical seed-metering devices to achieve effective seed-filling under high-speed planting conditions.MethodsFirstly, the key parameters of the core component were analyzed. Secondly, the influences of the seed posture adjusting efficiency and seed flow distribution characteristics on the seed-filling effect were clarified by the EDEM simulation. Finally, the high-speed metering performance was optimized and validated using bench testing.ResultsThe experiment demonstrated that the type A groove had the highest seed posture adjusting efficiency, a more uniform seed flow distribution, and a superior seed-filling effect as compared to the other groove types. The best metering performance was achieved with an opening angle of 21.6° and an opening width of 8.4 mm; this resulted in pass, repeat, and leak rates of 94.8%, 1.3%, and 3.9%, respectively. Within the speed range of 8–14 km/h, the posture-adjusting seed-metering device demonstrated a pass rate of over 94%, a repeat rate below 2.1%, and a leak rate below 3.9%.DiscussionThe designed device had a better high-speed planting capacity than a seed-metering device without a posture-adjusting mechanism, thus proving the effectiveness of the novel seed-filling method. These findings provide a reference for improving the high-speed planting capacity of mechanical seed-metering devices.

Clinical analysis of different intestinal reconstruction methods after primary cytoreductive surgery combined with rectal resection for advanced ovarian cancer

ObjectiveTo compare different intestinal reconstruction methods after intestinal resection for advanced ovarian malignancy.MethodsRetrospective data of patients with advanced ovarian malignancy were collected and then assigned into three groups: primary intestinal anastomosis, protective enterostomy and colostomy. General clinical characteristics, intraoperative findings and postoperative outcomes were compared between the three groups.ResultsA total of 530 cases were included for final analysis. The colostomy group had a lower serum albumin level, larger volume of ascites, higher likelihood of multiple intestinal resections and lower likelihood of rectal resection, lower peritoneal cancer index, more intraoperative blood loss, transfusions and infusions, lower likelihood of optimal cytoreductive surgery and shorter interval time to chemotherapy than the other two groups (p < 0.05). The primary intestinal anastomosis group exhibited a larger blood transfusion volume, higher incidence rates of anastomotic leak and electrolyte disturbance, and longer times to first flatus, first feeding and drain removal than the other two groups (p < 0.05).ConclusionsColostomy can be adopted for advanced ovarian cancer patients with a large ascites volume, hypoproteinemia, large intraoperative blood and fluid loss volumes, multiple intestinal resections, anastomoses located below the peritoneal reflection, high PCI and suboptimal cytoreductive surgery. For patients with good intraoperative and postoperative outcomes, one anastomosis, an anastomosis located above the peritoneal reflection, low PCI or optimal cytoreductive surgery, intestinal anastomosis can be carried out to restore the normal physiological function of the intestine. For patients with a large volume of ascites (≥500 mL), multiple anastomoses or an anastomosis located below the peritoneal reflection, intestinal anastomosis combined with protective enterostomy has an advantage over intestinal anastomosis alone.

Effect of percutaneous vertebroplasty through UTPP approach on prognosis and quality of life in elderly patients with osteoporotic vertebral compression fractures: a retrospective study

BackgroundTo explore the clinical characteristics of percutaneous vertebroplasty (PVP) via unilateral transverse process-pedicular (UTPP) approach in the treatment of osteoporotic vertebral compression fracture (OVCF) in the elderly.MethodsA total of 120 elderly patients with lumbar OVCF who underwent PVP via unilateral pedicular (UTP) and UTPP approaches in our hospital from January 2022 to January 2024 were retrospectively analyzed. The postoperative VAS score (visual analog scale), ODI score (Oswestry disability index), surgical indicators, and imaging indicators were recorded in the two groups.ResultsThe VAS scores and ODI scores of the two groups of patients were lower than those before surgery 1 day, 6 months, and 12 months after surgery (P < 0.05). The amount of bone cement (BC) injected in the UTPP group was greater than that in the UTP group, the excellent BC distribution rate was higher than that in the UTP group, and the BC leakage rate was lower than that in the UTP group (all P < 0.05). The vertebral anterior edge height and Cobb angle of the UTPP group were significantly different from those of the UTP group 1 day after surgery (P < 0.05).ConclusionsAfter UTPP-PVP, BC is fully diffused, the BC leakage rate is low, and the analgesic effect is good, which can enable patients to get out of bed early and improve their quality of life.

Assessing water status in rice plants in water-deficient environments using thermal imaging

BackgroundRice is a staple food for the global population. However, extreme weather events threaten the stability of the water supply for agriculture, posing a critical challenge to the stability of the food supply. The use of technology to assess the water status of rice plants enables the precise management of agricultural water resources.ResultsThe results of this study reveal that rice-producing regions with more severe drought have higher ion leakage rates, lower Soil Plant Analysis Development (SPAD) meter values, and reduced total chlorophyll content in plants. Although no significant differences were observed in red-green-blue (RGB) images, physiological parameters and canopy temperature differed significantly from conventional farming when infrared thermography was used to capture rice plants in the early stages of drought. The Crop Water Stress Index (CWSI), calculated from canopy temperature and atmospheric temperature, indicated a high correlation between access to water for rice plants and their physiological parameters. Regression analysis using CWSI and plant water status yielded a corrected coefficient of determination of 0.86.ConclusionOur study demonstrate that infrared thermography can effectively detect early signs of water stress in rice, aiding farmers in irrigation planning and enabling precise management and optimal utilization of water resources.

Foliar application of nano biochar solution elevates tomato productivity by counteracting the effect of salt stress insights into morphological physiological and biochemical indices

Nano-biochar considers a versatile and valuable sorbent to enhance plant productivity by improving soil environment and emerged as a novel solution for environmental remediation and sustainable agriculture in modern era. In this study, roles of foliar applied nanobiochar colloidal solution (NBS) on salt stressed tomato plants were investigated. For this purpose, NBS was applied (0%, 1% 3% and 5%) on two groups of plants (control 0 mM and salt stress 60 mM). Tween-20 was used as a surfactant to prolong NBS effective stay on plant leaf surface. The results showed that 3% NBS application effectively improved the plant height, plant biomass, fruit count and fruit weight under non-stressed and stressed plants. In addition, 3% NBS application further increased the plant pigments such as chlorophyll by 72% and 53%, carotenoids by 64% and 40%, leaf relative water content by 4.1 fold and 1.07 fold under both conditions, respectively. NBS application stabilized the plasma membrane via reducing electrolyte leakage by 30% as well as reduced the lipid peroxidation rates by 46% and 29% under non-stressed and stressed plants, respectively. 3% NBS application also significantly enhanced the plants primary and secondary metabolites, as well as activities of antioxidant enzymes compared to control plants. Overall, NBS foliar application significantly improved all growth and yield indices, pigments, primary and secondary metabolites, leaf water content, antioxidant enzyme activities as well as reduced electrolyte leakage and lipid peroxidation rates in tomato to combat stress conditions. In future, studies on nano biochar interactions with soil microbiota, surface modifications, long-term environmental impacts, reduced methane gas emissions, and biocompatibility could provide insights into optimizing its use in sustainable agriculture.

Risk factors for lymphatic leakage following radical cystectomy and pelvic lymph node dissection in patients with muscle-invasive bladder cancer

BackgroundLymphatic leakage is a common complication after radical cystectomy and pelvic lymph node dissection (PLND) for muscle-invasive bladder cancer (MIBC).This study aimed to investigate the risk factors contributing to postoperative lymphatic leakage in patients with MIBC.Materials and methodsA total of 534 patients undergoing radical cystectomy and PLND were enrolled in the retrospective study at Peking University Third Hospital from January 2010 to July 2023. Patients were categorized into lymphatic leakage(n = 254)and non-leakage groups (n = 280) and compared demographic, perioperativ and pathologic factors. Multivariate logistic regression was applied to identify risk factors for lymphatic leakage. Spearman correlation was used to analyze the relationship between lymph leakage ratio and risk factors.ResultsPatients with lymphatic leakage had significantly higher rates of receiving extended PLND (19.7% vs. 11.4%, p = 0.008), higher total number of dissected lymph nodes (median 11 vs. 8, p < 0.001), longer hospital stays (median 13 vs. 11 days, p < 0.001), higher postoperative hypoalbuminemia rate (56.7% vs. 36.4%, p < 0.001) and higher fever rate (14.2% vs. 8.6%, p = 0.04) compared to the non-leakage group. On multivariate analysis, higher number of dissected lymph nodes (OR 3.278, 95% CI 1.135–9.471, p = 0.028) was found to be a independent risk factor for lymphatic leakage. Additionally, a positive correlation was observed between the numbers of dissected lymph nodes and lymphatic leakage rate (R = 0.456, p = 0.013).ConclusionsThe increased number of dissected lymph nodes is associated with a heightened risk of lymphatic leakage following radical cystectomy for MIBC.

Outcomes of Colectomy for Nonmalignant Polyps and Colon Cancer: A Propensity Score-Matched Analysis.

In the United States, while most nonmalignant polyps are effectively treated through endoscopic removal, colectomy remains a treatment option for selected cases of nonmalignant polyps (NMPs) and colon cancer. This study aimed to compare postoperative outcomes for colectomies in these two conditions, hypothesizing similar complication rates. We conducted a retrospective review of the American College of Surgeons National Surgical Quality Improvement Program database from 2015 to 2021, including patients who underwent elective colectomies for colon cancer or NMPs. Using a 2:1 propensity score matching for demographics, American Society of Anesthesiologists classification, surgical methods, and comorbidities, we evaluated outcomes such as 30-d mortality, complications, anastomotic leakage, and hospital stay duration. A total of 47,960 patients, including 30,549 colon cancer patients and 17,411 NMP patients, were included after propensity score matching analysis. We concluded that there was no significant difference in mortality and reoperation rates which were 0.6% and 3.3% in patients undergoing colectomy with colon cancer, compared to 0.5% and 3.1% in those with NMP, respectively [P=0.64, P=0.21,]. In addition, the anastomotic leak rates were remarkably similar in both the colon cancer (2.4%) and NMP (2.2%) groups. [P=0.13]. Most of the 30-d postoperative surgical complications, such as sepsis, septic shock, wound disruption, and urinary tract infection exhibited similar incidence rates, however, some of them, such as readmission, pulmonary embolism, and length of stay, varied between the groups. Our findings underscore the similar postoperative outcomes between colon cancer and NMP groups, advocating for consideration of advanced endoscopic techniques for NMPs to potentially enhance patient care and outcomes.

Study on Smoke Leakage Performance in Mass Timber Construction Taking Cross-Laminated Timber Walls as an Example

In contemporary building design, partition walls combined with doors and windows are commonly used to control the spread of smoke. Understanding the smoke leakage characteristics of cross-laminated timber (CLT) walls is crucial for enhancing safety. This study investigates the smoke-sealing performance of CLT walls through full-scale tests, focusing on the application of this type of mass timber construction in smoke control. The test specimens included four joints, with leakage measured under two conditions—non-fire and fire exposure—at three different pressure differentials. A total of 72 tests were conducted. The results showed that under non-fire conditions, the leakage rate was 0.00 m³/h, while exposure to fire caused a significant increase in leakage. Under a pressure differential of 25 Pa, the average leakage rate was 8.17 m³/h, with a maximum of 8.27 m³/h. This study also proposes a method for evaluating the leakage rate of a single joint, which helps estimate the smoke layer descent time and, in turn, the allowable evacuation time. The findings not only enhance the fire safety performance of mass timber construction but also provide valuable insights for evacuation planning.

Mosaic ceramic surface defect detection enhancement algorithm based on guided filter and multi-scale fusion

Abstract This study proposes an enhanced algorithm based on guided filter and multi-scale fusion that detects surface defects of mosaic ceramics, allowing to tackle the small and difficult-to-detect surface reflection problem. This method first combines the gathered multi-angle light source images to obtain the highlight removal image. The guided filter then separates the image into base and detail images. Afterwards, the contrast limited adaptive histogram equalization (CLAHE) algorithm is used to enhance the detailed image. Taplacian contrast weights, saliency weights, and saturation weights are then introduced for the multi-scale fusion of the base and detail images. Finally, defects are extracted by non-linear enhancement, threshold segmentation, morphological processing, and the Canny operator. The proposed algorithm can effectively remove the mosaic ceramic surface highlights, enhance the details of the defect edges, remove the noise interference, improve the overall image quality, and perform rapid detection of defects on the surface of mosaic ceramics. Experiments are then conducted to verify the efficiency of the proposed algorithm. The results show that it has high performance, and it reaches a mosaic ceramic defect detection accuracy of 97.9 % with low leakage and false detection rates of 2.1 % and 1 %.

Development of a Tool for Verifying Leakage Detection in Microfluidic Systems

While submissions of microfluidic-based medical devices to the Food and Drug Administration (FDA) have increased in recent years, leakage remains a common but difficult failure mode to detect in microfluidic systems. Here, we have developed a sensitive tool to measure and verify leakages ranging from 0.1% to 10% in leakage detection systems, which can then be used to detect leak in microfluidic devices. Our methodology includes an analytical model that applies hydrodynamic resistance using different fluid-contacting elements (e.g., tubing, junctions, and connectors) to tune the leakage rate based on the application-specific acceptance criteria. We then used three polymer-based microfluidic systems to target leakage rates of approximately 0.1, 1.0, and 10%. The experimental uncertainties in Polyether Ether Ketone (PEEK) tubing were 23.08%, 13.64%, and 1.16%, respectively, while the PEEK-Coated Fused Silica (PEEKsil) tubing system had errors of 0.00%, 0.72%, and 1.59%, respectively, relative to the theoretical values for the same target leak rates. The commonly used commercial grade Cyclic Olefin Copolymer (COC) microfluidic chips produced errors of 7.69% and 5.05%, respectively, for target leakage rates of 0.24% and 1.88%. We anticipate that the proposed bench test method can be useful for device developers as a verification tool for leakage detection systems before assessing flow-mediated leakage failure modes in microfluidic medical devices.

P0657 Quality of ileocolic resection in Crohn’s disease- A systemic review and meta-analysis

Abstract Background The terminal ileum is the most common site affected by Crohn’s disease and the area most commonly requiring surgical management. Post operatively, there is large heterogeneity between patient outcomes; with a proportion requiring no further medical or surgical management, whilst others will require life-long management with repeated operations. The reason for this remains unclear. Surgical key performance indicators for an ileocolic resection can include: recurrence, rate of anastomotic leak, post-operative complications (Clavien Dindo (CD) &amp;gt;3), length of stay, re-admission rate and mortality. The aim of this study was to evaluate the effects of mode of surgery, the extent of mesenteric excision and the type of anastomosis on the rate of recurrence. Methods A systematic review was conducted following a priori protocol. Covidence software was used to exclude duplicates, screen studies and extract data. Extracted data was analysed. The primary outcome was recurrence rate and the mode of detection. Secondary outcomes were; anastomotic leak, post-operative complications (CD &amp;gt;3), length of stay, readmission rate, mortality and duration of follow up. Combined overall effect size was calculated using SPSS software. The revised Cochrane risk of bias tool and the Newcastle-Ottawa scale were used to assess risk of bias. Results A total of 24 studies were included. Four (three randomised controlled trials (RCTs)) in the mode of surgery group, four in the extent of mesenteric resection group and sixteen (two RCTs) in the type of anastomosis group. In all four studies included in the mode of surgery group, laparoscopic surgery was associated with a shorter length of stay. No difference was observed in the other outcomes, including rate of recurrence. There was no significant correlation between extended versus limited mesenteric excision and the rate of recurrence (p0.307, OR 0.61 (CI95% -.056, 1.77)). Four studies compared Kono-S anastomosis versus non-Kono-S anastomosis. Kono-S anastomosis was associated with a significantly lower recurrence rate (p=0.002, OR 0.62 (CI95% 0.24, 1.01)). There was significant heterogeneity between these studies (p&amp;lt;0.001). Conclusion To date there is no convincing evidence that the mode of surgery, the extent of the mesenteric excision or the type of anastomosis have any significant effect on reducing the occurrence of Crohn’s recurrence at the anastomosis. References N/A

Does Cerebrospinal Fluid Leak in Pituitary Surgery Affect Patient Reported Quality of Life?

Endoscopic techniques allow for improved visualization and tumor debulking of pituitary adenomas. More thorough tumor resection, however, can be associated with higher rates of CSF leaks. We set out to determine if CSF leaks influenced patient perceived quality of life outcomes. This retrospective study included 152 patients who underwent endoscopic pituitary tumor resection over a 10-year period. QoL was assessed using the SF-36 questionnaire and completed before surgery, 6 weeks and 6 months post-operatively. Statistical analysis was conducted using a equivalence test and a two-way mixed model ANOVA to assess intraoperative CSF leak, postoperative CSF leak, redo surgery, and the use of a lumbar drain. Of the 152 patients, 98 had a potential intraoperative CSF leak. Intra- and postoperative CSF leaks did not significantly impact patient reported QoL outcomes at 6 months following surgery. There was clinical equivalence in mental scores as early as 6 weeks and 6 months for physical scores. There was no statistically significant difference in physical (p-value = 0.975) and mental (p = 0.204) scores for patients who experienced a postoperative CSF leak. There was no statistically significant difference in QoL in the mental and physical scores for patients that received a lumbar drain (physical score p = 0.832; mental score p = 0.915) or redo surgery (physical score p = 0.830; mental score p = 0.204). This article demonstrates that CSF leaks do not impact patient-reported QoL outcomes at 6 months post-surgery. This will allow surgeons to better provide insight and counsel patients regarding the relevance of CSF leaks in the setting of pituitary procedures. III Laryngoscope, 2025.

The impact of indocyanine green fluorescence angiography (ICG-FA) on anastomotic leak rates and postoperative outcomes in colorectal anastomoses: a systematic review.

Anastomotic leak (AL) is a major complication in colorectal surgery, significantly contributing to perioperative morbidity and mortality. Among strategies to prevent AL, Indocyanine Green Fluorescence Angiography (ICG-FA) has emerged as a promising method for assessing bowel perfusion intraoperatively. This systematic review evaluates the impact of ICG-FA on AL rates and other postoperative outcomes following colorectal anastomoses. A systematic search was conducted in PubMed, PubMed Central, MEDLINE, and Google Scholar, following PRISMA guidelines. Eligible studies included randomized controlled trials (RCTs), prospective cohort studies, and retrospective cohort studies comparing ICG-FA to controls in adult patients undergoing colorectal resections and anastomoses. Data on AL rates, intraoperative characteristics, and postoperative outcomes were extracted. Quality assessment was performed using the Newcastle-Ottawa Scale and the Revised Cochrane Risk-of-Bias Tool. Sixteen studies (12 retrospective, 1 prospective, and 3 RCTs) involving 3231 patients (1562 ICG-FA and 1669 controls) were included. AL rates were significantly lower in the ICG-FA group (5.18%) compared to controls (11.50%) (p < 0.01). ICG-FA influenced surgical plans in 16.31% of cases. Operative time and ileostomy formation rates were comparable between groups. Reoperation, ileus, and wound infection rates showed minimal differences. Mortality rates were low in both groups (ICG-FA: 0.55%, control: 0.51%). ICG-FA significantly reduces AL rates without increasing operative time or postoperative complications. This technique provides a reliable and safe assessment of bowel perfusion, supporting its integration into colorectal surgery protocols. Further high-quality RCTs are needed to confirm these findings and optimise its application.

Personalized optimization of systematic prostate biopsy core number based on mpMRI radiomics features: a large-sample retrospective analysis

BackgroundProstate cancer (PCa) is definitively diagnosed by systematic prostate biopsy (SBx) with 13 cores. This method, however, can increase the risk of urinary retention, infection and bleeding due to the excessive number of biopsy cores.MethodsWe retrospectively analyzed 622 patients who underwent SBx with prostate multiparametric MRI (mpMRI) from two centers between January 2014 to June 2022. The MRI data were collected to manually segment Regions of Interest (ROI) of the tumor layer by layer. ROI reconstructions were fused to form outline of the volume of interest (VOI), which were exported and applied to subsequent extraction of radiomics features. The t-tests, Mann-Whitney U-tests and chi-squared tests were performed to evaluate the significance of features. The logistic regression was used for calculating the PCa risk score (PCS). The PCS model was trained to optimize the SBx core number, utilizing both mpMRI radiomics and clinical features.ResultsThe predicted number of SBx cores was determined by PCS model. Optimal core numbers of SBx for PCS subgroups 1–5 were calculated as 13, 10, 8, 6, and 6, respectively. Accuracies of predicted core numbers were high: 100%, 95.8%, 91.7%, 90.6%, and 92.7% for PCS subgroups 1–5. Optimized SBx reduced core rate by 41.9%. Leakage rates for PCa and clinically significant PCa were 8.2% and 3.4%, respectively. The optimized SBx also demonstrated high accuracy on the validation set.ConclusionThe optimization PCS model described in this study could therefore effectively reduce the number of systematic biopsy cores obtained from patients with high PCS, especially for biopsy cores far away from suspicious lesions. This method can enhance patient experience without reducing tumor detection rate.

Optimization of the Design of Underground Hydrogen Storage in Salt Caverns in Southern Ontario, Canada

With the issue of energy shortages becoming increasingly serious, the need to shift to sustainable and clean energy sources has become urgent. However, due to the intermittent nature of most renewable energy sources, developing underground hydrogen storage (UHS) systems as backup energy solutions offers a promising solution. The thick and regionally extensive salt deposits in Unit B of Southern Ontario, Canada, have demonstrated significant potential for supporting such storage systems. Based on the stratigraphy statistics of unit B, this study investigates the feasibility and stability of underground hydrogen storage (UHS) in salt caverns, focusing on the effects of cavern shape, geometric parameters, and operating pressures. Three cavern shapes—cylindrical, cone-shaped, and ellipsoid-shaped—were analyzed using numerical simulations. Results indicate that cylindrical caverns with a diameter-to-height ratio of 1.5 provide the best balance between storage capacity and structural stability, while ellipsoid-shaped caverns offer reduced stress concentration but have less storage space, posing practical challenges during leaching. The results also indicate that the optimal pressure range for maintaining stability and minimizing leakage lies between 0.4 and 0.7 times the vertical in situ stress. Higher pressures increase storage capacity but lead to greater stress, displacements, and potential leakage risks, while lower pressure leads to internal extrusion tendency for cavern walls. Additionally, hydrogen leakage rate drops with the maximum working pressure, yet total leakage mass keeps a growing trend.

Outcomes Following Fenestrated/Branched Endovascular Aortic Repair for Failed Open Infrarenal Aortic Repair Compared with Primary Fenestrated/Branched Endovascular Aortic Repair.

As aneurysmal disease is progressive, proximal disease progression and para-anastomotic aneurysms are complications experienced after open infrarenal abdominal aortic aneurysm repair (AAA). As such, fenestrated or branched endovascular repair (F/BEVAR) may be indicated in these patients. Data describing fenestrated endovascular aneurysm repair after prior open repair are limited to institutional databases. The aim of our study is to describe the safety and efficacy of fenestrated/branched endovascular aneurysm repair (F/BEVAR) in patients with prior open repair (OSR) compared with primary F/BEVAR using the Vascular Quality Initiative. Using the VQI complex endovascular AAA module from 2014-2022, we identified all single-staged F/BEVAR repair in patients having prior OSR or no prior aortic surgery (primary F/BEVAR). The primary outcomes were perioperative mortality and completion endoleaks. Secondary outcomes were 5-year survival and one-year sac dynamics. Between the two cohorts, differences in the primary and secondary outcomes were evaluated using Wilcoxon-Rank Sum tests for continuous variables and Chi-squared analysis for categorical variables. Kaplan-Meier methods and Cox-regression were used to examine 5-year mortality. We identified 3,331 primary F/BEVAR patients and 102 prior OSR patients. Patients with prior OSR were more likely to have peripheral arterial disease (22% vs. 7.4%), prior smoking (67% vs 56%), undergo F/BEVAR with medium/high volume physicians (74% vs 62%), but less likely to be female (8.8% vs 23%) (all p<0.05). Patients with prior OSR were also more likely to have a more proximal aneurysm extent (median zone 7[6-8] vs. 8[7-8]), larger AAA diameters (62[56-66] mm vs 58[55-63] mm), receive a physician modified endograft (PMEG) vs commercial custom-made device (CCMD) (36% vs 20% PMEG), have longer surgery times (240[186-308] min vs. 206[155-272] min), and have a higher rate of celiac (51% vs 26%) and SMA (86% v 73%) artery involvement (all p < 0.05). Patients with prior OSR had lower rates of completion endoleaks (25% vs 36%) driven by lower rates of type II leaks (11% vs 20%) despite higher rates of indeterminate leaks (11% vs. 5.1%) (all p<0.01). There was, however, no difference in perioperative mortality (2% vs. 2.9%; p = 0.78). They had similar one-year sac dynamics (48% vs. 50% regression; 12% vs 8% expansion, p>0.5) and 5-year mortality (23% vs 18%, HR: 1.44[0.89-2.31]; p=0.13). Based on VQI data, F/BEVAR after prior OSR seems to be well-tolerated and safe. Prior open repair patients also had lower rates of completion type II endoleaks and similar sac dynamics and 5-year mortality compared to primary F/BEVAR patients.

Simulation and experiment investigation on leakage rate of composite materials with the consideration of curing defects

Simulation and experiment investigation on leakage rate of composite materials with the consideration of curing defects