Study on large deformation of soil-rock mixed slope based on GPU accelerated material point method.

This study assesses the effect of stone content on the stability of soil-rock mixture slopes and the dynamics of ensuing large displacement landslides using a material point strength reduction method. This method evaluates structural stability by incrementally decreasing material strength parameters. The author created four distinct soil-rock mixture slope models with varying stone contents yet consistent stone size distributions through digital image processing. The initial conditions were established by linearly ramping up the gravity in fixed proportionate steps until the full value was attained. Stability was monitored until a sudden shift in displacement marked the onset of instability. Upon destabilization, the author employed the material point method to reconstruct the landslide dynamics. Due to the substantial computational requirements, the author developed a high-performance GPU-based framework for the material point method, prioritizing the parallelization of the MPM algorithm and the optimization of data structures and memory allocation to exploit GPU parallel processing capabilities. Our results demonstrate a clear positive correlation between stone content and slope stability; increasing stone content from 10 to 20% improved the safety factor from 1.9 to 2.4, and further increments to 30% and 40% ensured comprehensive stability. This study not only sheds light on slope stability and the mechanics of landslides but also underscores the effectiveness of GPU-accelerated methods in handling complex geotechnical simulations.

Choledochoduodenostomy Versus Hepaticogastrostomy in Endoscopic Ultrasound-guided Drainage for Malignant Biliary Obstruction: A Meta-analysis and Systematic Review.

OBJECTIVES: This study aimed to estimate the safety and efficacy of endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) and endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) for malignant biliary obstruction. METHODS: We conducted a literature search using PubMed, Embase, Web of Science, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov. Studies that compared EUS-CDS and EUS-HGS were included in this study. RESULTS: Thirteen studies were eligible for inclusion. The technical [odds ratio (OR): 0.95; 95% confidence interval (CI): 0.51-1.74) and clinical (OR: 1.13; 95%CI: 0.66-1.94) success rates of EUS-CDS were comparable to those of EUS-HGS. However, EUS-CDS had less reintervention (OR: 0.31; 95%CI: 0.16-0.63) and stent obstruction (OR: 0.48; 95%CI: 0.21-0.94) than EUS-HGS. Both groups had similar adverse events (OR: 1.00; 95%CI: 0.70-1.43) and overall survival (hazard ratio: 1.07; 95%CI: 0.58-1.97). CONCLUSIONS: EUS-CDS and EUS-HGS have comparable technical and clinical success rates, adverse events, and overall survival. However, EUS-CDS has less reintervention and stent obstruction.

Assessment of ¹88Re marked anti MHC class II antibody by peripheral blood mononuclear cells stimulated by donor alloantigen.

BACKGROUND: Previous studies showed that anti MHC-II monoclone antibody (MAb) only had partial inhibiting effect of alloreactive mixed lymphocyte reaction (MLR) in vitro and it was unsteady and non-persistent. The aim of this research was to determine whether radioactive isotope (188)Re marked MHC-II antibody could benefit the allograft acceptance in transplantation as compared to normal MHC-II antibody. METHODS: 188Re was incorporated to 2E9/13F (ab')(2) which is against swine MHC class II antigen (MAb-(188)Re). Porcine peripheral blood mononuclear (PBMC) cells were examined for proliferation and cytokine mRNA expression after stimulation with MHC-II MAb or MAb-(188)Re. RESULTS: The proliferative response of recipient PBMCs in mixed lymphocyte reaction (MLR) to donor alloantigen showed that the stimulation index of MAb-(188)Re group was significantly lower than the MHC-II MAb group and control (P < 0.05). mRNA expression of interleukin 2, interferon Υ and tumor necrosis factor α (type 1 cytokines) was lower in MAb-(188)Re group than the MHC-II MAb group, while interleukin 10 (type 2 cytokines) was higher in MAb-(188)Re group in the first 24 hours. CONCLUSION: MAb-(188)Re could help the graft acceptance by inhibiting T cell proliferation, lowering the expression of type 1 cytokines and elevating the type 2 cytokines produced by PBMC.

Correlation of nitric oxide and other free radicals with the severity of acute pancreatitis and complicated systemic inflammatory response syndrome.

OBJECTIVES: To investigate the correlation of nitric oxide (NO) and other free radicals with the severity of acute pancreatitis (AP) and complicated systemic inflammatory response syndrome (SIRS). METHODS: Fifty AP patients (24 simple AP patients and 26 patients with AP complicated by SIRS) were involved in the study. Fifty healthy volunteers were included as controls. Acute Physiology and Chronic Health Evaluation II (APACHE II) scores were evaluated, and plasma NO, plasma lipid peroxides, plasma vitamin E, plasma beta-carotene, whole-blood glutathione (GSH), and the activity of plasma GSH peroxidase were measured. RESULTS: Compared with the control group, the APACHE II scores heightened in the AP group, and the SIRS group had the highest APACHE II scores (P < 0.005, P < 0.001, respectively). Plasma NO and plasma lipid peroxides increased with the heightening APACHE II scores, demonstrating a significant linear positive correlation (r = 0.618, r = 0.577, respectively; P < 0.001). Plasma vitamin E, plasma beta-carotene, whole-blood GSH, and the activity of plasma GSH peroxidase decreased with the heightening APACHE II scores, demonstrating a significant linear negative correlation (r = -0.600, r = -0.609, r = -0.559, r = -0.592, respectively; P < 0.001). CONCLUSIONS: Nitric oxide and other free radicals take part in the aggravation of oxidative stress and oxidative injury and may play important roles in the pathogenesis of AP and SIRS. It may be valuable to measure free radicals to predict the severity of AP.