184 research outputs found

    Numerical investigation of breaking wave loads on the downstream inclined cylinder under shelter effect from the upstream vertical cylinder

    Get PDF
    Breaking waves interaction with two tandem cylinders are numerically studied using Computational Fluid Dynamic (CFD) software OpenFOAM. The effects of transverse inclined angles of the downstream cylinder and separation distances between two cylinders on breaking wave loads and free surface elevations are investigated. The interface between air and water phases is captured by the Volume of Fluid (VOF) method. The Shear Stress Transport k − v(SST k − v) turbulence model is employed to solve the incompressible Reynolds-Averaged Navier-Stokes (RANS) equations. The present numerical model is validated against published experimental data by examining the horizontal breaking wave loads and free surface elevations of breaking waves past a vertical cylinder and an inclined cylinder. In the present incident wave conditions, the breaking wave force on the downstream cylinder decreases first and then increases with the transverse inclined angle varying from 0o to 30o, while it shows an opposite trend versus the distance between cylinders. The maximum breaking wave load on the downstream cylinder occurs when the it is installed vertically with a separation distance of four times diameter.publishedVersio

    Effect of inlet splitter on pressure fluctuations in a double-suction centrifugal pump

    Get PDF
    In order to investigate the effect of inlet splitter on pressure fluctuations in a double-suction centrifugal pump, three research schemes, including no splitter (scheme I), a splitter along the flow passage centerline (scheme II) and a splitter above the flow passage centerline in the suction (scheme III), were designed. The flow in the pump was simulated by commercial code FLUENT. The viscous Navier-Stokes equations were handled with an unsteady calculation and the sliding mesh technique was applied to take into account the impeller-volute interaction. Based on the simulation results, the hydraulic performance and pressure fluctuations were obtained and analyzed in detail. The hydraulic performance agrees well with the experimental results. The pressure fluctuations under three schemes are different. The maximum amplitude of the pressure fluctuations in scheme II is the minimum. For monitoring points near volute tongue, rotating frequency and its harmonies are dominant under three research schemes. The maximum amplitude of pressure fluctuations of three schemes are all at the blade passing frequency. In particular, the maximum pressure fluctuation amplitude of scheme II was less than that of scheme I and scheme III, which illustrated that it is effective to reduce the peak value of pressure fluctuations in double suction centrifugal pump by installing a splitter in the suction properly

    Patients\u27 Acceptance of Smartphone Health Technology for Chronic Disease Management: A Theoretical Model and Empirical Test

    Get PDF
    Les quatre textes ont en commun de présenter certaines évolutions récentes de l’histoire politique en Allemagne. Ils prennent tous position face à trois tournants historiographiques. La notion d’histoire culturelle du politique peut servir d’emblème au premier de ces tournants : le politique est envisagé non plus comme une succession d’événements ni comme le fruit de déterminations structurelles dont il serait la superstructure ou l’écume, mais comme l’expression de valeurs et de procédures o..

    Simple transanal total mesorectal resection versus laparoscopic transabdominal total mesorectal resection for the treatment of low rectal cancer: a single-center retrospective case-control study

    Get PDF
    AimTo evaluate the efficacy and safety of simple TaTNE in the treatment of low rectal cancer compared with laparoscopic transabdominal TME.MethodsWe collected patients with low rectal cancer admitted to our hospital between January 2019 and November 2021 who received simple TaTME or laparoscopic transabdominal TME. The main outcome was the integrity of the TME specimen. Secondary outcomes were the number of lymph nodes dissected, intraoperative blood loss, operative time, surgical conversion rate, Specimen resection length, circumferential margin (CRM), and distal resection margin (DRM), complication rate. In addition, the Wexner score and LARS score of fecal incontinence were performed in postoperative follow-up.ResultsPathological tissues were successfully resected in all patients. all circumferential margins of the specimen were negative. Specimen resection length was not statistically significant (9.94 ± 2.85 vs. 8.90 ± 2.49, P > 0.05). The incidence of postoperative complications in group A (n = 0) was significantly lower than that in group B (n = 3) (P > 0.05). There was no significant difference in operation time between group A and group B (296 ± 60.36 vs. 305 ± 58.28, P > 0.05). Among the patients with follow-up time less than 1 year, there was no significant difference in Wexner score and LARS score between group A and group B (P > 0.05). However, in patients who were followed up for more than 1 year, the Wexner score in group A (9.25 ± 2.73) was significantly lower than that in group B (17.36 ± 10.95) and was statistically significant (P < 0.05).ConclusionFor radical resection of low rectal cancer, Simple TaTME resection may be as safe and effective as laparoscopic transabdominal TME, and the long-term prognosis may be better

    Protocatechuic acid: A novel detoxication agent of fumonisin B1 for poultry industry

    Get PDF
    Fumonisin B1 (FB1) is a major fusarium mycotoxin that largely contaminates feedstuffs and foods, posing a health risk to both animals and humans. This mycotoxin can enter the human body directly through contaminated food consumption or indirectly by toxins and their metabolites. In a prior study, feed-borne FB1 is one of the leading mycotoxins in breeder eggs, leading to reduced hatchability and gizzard ulceration in chicken progenies. Currently, no effective way is available to remove FB1 from feeds and human-contaminated foods. We hypothesize that FB1 can be reduced to low risk by protocatechuic acid (PCA). To assess the ability of FB1 to be degraded in vivo, 1 ppm of FB1 was treated with PCA, or D-glucose, or silymarin, or anti-FB1 monoclonal antibody. Our study revealed that both D-glucose and PCA exhibited 53.4 and 71.43% degradation, respectively, at 80°C for 2 h, while 35.15% of FB1 detoxification was determined in the silymarin group at 60°C for 0.5 h. A dose-dependent manner was found after treatment with D-glucose or PCA at 80°C for 2 h. As for detoxification of anti-FB1 monoclonal antibody, the 1:3,000 dilution induced significant FB1 detoxification, accounting for 25.9% degradation at 25°C for 2 h. Furthermore, 50 SPF 11-day-old embryonated eggs were divided into 10 groups, with five eggs per group. Post treatment with PCA or D-glucose, or silymarin or anti-FB1 monoclonal antibody, the treated samples were inoculated into albumens and monitored daily until the hatching day. Consequently, 100% of the chickens survived in the D-glucose group and other control groups, except for the FB1 control group, while 80, 80, and 60% hatching rates were found in the PCA-treated group, the anti-FB1 monoclonal antibody-treated group, and the silymarin-treated group. Additionally, both the FB1 group and the silymarin-treated group yielded lower embryo growth than other groups did. Postmortem, lower gizzard ulceration index was determined in the PCA-treated group and the anti-FB1 monoclonal antibody-treated group compared to those of the silymarin-treated group and D-glucose-treated group. Based on the above evidence, PCA is a promising detoxification to reduce FB1 contamination in the poultry industry, contributing to the eradication of mycotoxin residuals in the food chain and maintaining food security for human beings

    Baicalin Depresses the Sympathoexcitatory Reflex Induced by Myocardial Ischemia via the Dorsal Root Ganglia

    Get PDF
    Myocardial ischemia (MI) is one of the major causes of death in cardiac diseases. Purinergic signaling is involved in bidirectional neuronal-glial communication in the primary sensory ganglia. The sensory neuritis of cardiac afferent neurons in cervical dorsal root ganglion (cDRG) interacts with cardiac sympathetic efferent postganglionic neurons, forming feedback loops. The P2Y12 receptor is expressed in satellite glial cells (SGCs) of DRG. Baicalin is a major active ingredient extracted from natural herbal medicines, which has anti-inflammatory and strong anti-oxidation properties. In this study we investigated the effect of baicalin on P2Y12 receptor in the cervical DRG SGC-mediated sympathoexcitatory reflex, which is increased during MI. The results showed that the expression of P2Y12 receptor mRNA and protein in DRG, and the co-localization values of P2Y12 receptor and glial fibrillary acidic protein (GFAP) in cDRG SGCs were increased after MI. The activated SGCs increased IL-1β protein expression and elevated Akt phosphorylation in cDRG. Baicalin treatment inhibited the upregulation of the P2Y12 receptor, GFAP protein and Akt phosphorylation in cDRG neurons/SGCs. The stellate ganglia (SG) affect cardiac sympathetic activity. Baicalin treatment also decreased the upregulation of the P2Y12 receptor, GFAP protein in the SG. The P2Y12 agonist, 2Me-SADP, increased [Ca2+]i in HEK293 cells transfected with the P2Y12 receptor plasmid and SGCs in cDRG. These results indicate that application of baicalin alleviates pathologic sympathetic activity induced by MI via inhibition of afferents in the cDRG

    Ubiquitin ligase RNF125 targets PD-L1 for ubiquitination and degradation

    Get PDF
    As a critical immune checkpoint molecule, PD-L1 is expressed at significantly higher levels in multiple neoplastic tissues compared to normal ones. PD-L1/PD-1 axis is a critical target for tumor immunotherapy, blocking the PD-L1/PD-1 axis is recognized and has achieved unprecedented success in clinical applications. However, the clinical efficacy of therapies targeting the PD-1/PD-L1 pathway remains limited, emphasizing the need for the mechanistic elucidation of PD-1/PD-L1 expression. In this study, we found that RNF125 interacted with PD-L1 and regulated PD-L1 protein expression. Mechanistically, RNF125 promoted K48-linked polyubiquitination of PD-L1 and mediated its degradation. Notably, MC-38 and H22 cell lines with RNF125 knockout, transplanted in C57BL/6 mice, exhibited a higher PD-L1 level and faster tumor growth than their parental cell lines. In contrast, overexpression of RNF125 in MC-38 and H22 cells had the opposite effect, resulting in lower PD-L1 levels and delayed tumor growth compared with parental cell lines. In addition, immunohistochemical analysis of MC-38 tumors with RNF125 overexpression showed significantly increased infiltration of CD4+, CD8+ T cells and macrophages. Consistent with these findings, analyses using The Cancer Genome Atlas (TCGA) public database revealed a positive correlation of RNF125 expression with CD4+, CD8+ T cell and macrophage tumor infiltration. Moreover, RNF125 expression was significantly downregulated in several human cancer tissues, and was negatively correlated with the clinical stage of these tumors, and patients with higher RNF125 expression had better clinical outcomes. Our findings identify a novel mechanism for regulating PD-L1 expression and may provide a new strategy to increase the efficacy of immunotherapy

    SNX14 deficiency-induced defective axonal mitochondrial transport in Purkinje cells underlies cerebellar ataxia and can be reversed by valproate

    Get PDF
    共济失调是一类以运动协调性紊乱为主要特征的神经系统症状,临床表现包括步态不稳、丧失平衡、吞咽困难、眼球运动异常、肌张力受损等。厦门大学医学院神经科学研究所王鑫教授团队首次从轴突线粒体运输这一全新视角揭示了一类遗传性共济失调的发病机制,并发现抗癫痫药--丙戊酸大幅度减缓模型小鼠的疾病进程,具有较强的转化应用价值,有望为共济失调提供新的治疗手段。 该研究工作由王鑫教授指导完成,厦门大学医学院助理教授张洪峰和博士生洪育娟共同完成主要实验工作。Loss-of-function mutations in SNX14 cause autosomal recessive spinocerebellar ataxia 20, which is a form of early-onset cerebellar ataxia that lacks molecular mechanisms and mouse models. We generated Snx14-deficient mouse models and observed severe motor deficits and cell-autonomous Purkinje cell degeneration. SNX14 deficiency disrupted microtubule organization and mitochondrial transport in axons by destabilizing the microtubule-severing enzyme spastin, which is implicated in dominant hereditary spastic paraplegia with cerebellar ataxia, and compromised axonal integrity and mitochondrial function. Axonal transport disruption and mitochondrial dysfunction further led to degeneration of high-energy-demanding Purkinje cells, which resulted in the pathogenesis of cerebellar ataxia. The antiepileptic drug valproate ameliorated motor deficits and cerebellar degeneration in Snx14-deficient mice via the restoration of mitochondrial transport and function in Purkinje cells. Our study revealed an unprecedented role for SNX14-dependent axonal transport in cerebellar ataxia, demonstrated the convergence of SNX14 and spastin in mitochondrial dysfunction, and suggests valproate as a potential therapeutic agent.We thank Tim Huang for helpful discussion, Wei Mo for sharing mouse lines, Li Zhong for sharing reagents, Aidong Han, Luming Yao, Caiming Wu, Mingxia Zhu, Qingfeng Liu, Lin Zhu, Shuo Zhang, Haiping Zheng, and Changchuan Xie for technical assistance, and Cui Li for providing bioinformatics software. We also thank Novogene Co., Ltd. and PTM Biolab Co., Ltd. for technical assistance in the transcriptomic and proteomic analyses, respectively. 厦门大学医学院许华曦、赵颖俊、张云武、杜丹教授在研究过程中给予大力帮助和支持。本研究工作得到国家重点研发计划项目、国家自然科学基金、福建省自然科学基金、厦门大学校长基金的资助和支持

    Space advanced technology demonstration satellite

    Get PDF
    The Space Advanced Technology demonstration satellite (SATech-01), a mission for low-cost space science and new technology experiments, organized by Chinese Academy of Sciences (CAS), was successfully launched into a Sun-synchronous orbit at an altitude of similar to 500 km on July 27, 2022, from the Jiuquan Satellite Launch Centre. Serving as an experimental platform for space science exploration and the demonstration of advanced common technologies in orbit, SATech-01 is equipped with 16 experimental payloads, including the solar upper transition region imager (SUTRI), the lobster eye imager for astronomy (LEIA), the high energy burst searcher (HEBS), and a High Precision Magnetic Field Measurement System based on a CPT Magnetometer (CPT). It also incorporates an imager with freeform optics, an integrated thermal imaging sensor, and a multi-functional integrated imager, etc. This paper provides an overview of SATech-01, including a technical description of the satellite and its scientific payloads, along with their on-orbit performance
    corecore