前级叶片安装角对对旋轴流风机的性能影响

为研究两级动叶安装角可调的对旋轴流风机的前级叶片安装角与风机整体性能的匹配,本文利用CFD软件,对风机模型进行了三维全流场数值模拟与分析。结果表明:在小流量工况下,适当调小风机的前级叶片安装角可以提高风机的效率;风机在运行过程中,根据当前工况选择合适的安装角,可以有效提高对旋轴流风机的整体性能,改善各流动参数在风机中的分布情况,减少流动损失,扩大工作范围,延迟风机失速和喘振的发生。

Transjugular intrahepatic portosystemic shunt for pyrrolizidine alkaloid-related hepatic sinusoidal obstruction syndrome

BACKGROUND Treatments for hepatic sinusoidal obstruction syndrome(HSOS)are limited.AIM To evaluate transjugular intrahepatic portosystemic shunting(TIPS)as a treatment for pyrrolidine alkaloid-related HSOS(PA-HSOS).METHODS This retrospective analysis included patients with PA-HSOS admitted to the First Affiliated Hospital of the University of Science and Technology of China(June 2015 to January 2019).Baseline clinical characteristics and follow-up data were extracted from the medical records.All patients included in this study experienced failure of initial therapy.Patients were divided into the TIPS and conservative treatment groups according to the therapy they received.Liver function,maximal ascites depth,imaging characteristics,pathology findings,and survival were compared between groups.RESULTS The TIPS group included 37 patients(28 males),and the conservative treatment group included 17 patients(11 males).Baseline characteristics were similar between groups.There were two deaths in the TIPS group and seven deaths in the conservative treatment group during follow-up(3-48 mo).The 3-,6-,12-and 24-mo survival rates were 94.6%,94.6%,94.6%and 94.6%,respectively,in the TIPS group and 70.6%,57.8%,57.8%and 57.8%,respectively,in the conservative treatment group.Kaplan-Meier analysis revealed significantly longer survival for the TIPS group than for the conservative treatment group(P=0.001).Compared with the pre-treatment value,maximal ascites depth was significantly lower at 1 wk,2 wk,1 mo,and 3 mo for the TIPS group(all P<0.05)but not in the conservative treatment group.Contrast-enhanced computed tomography demonstrated the disappearance of patchy liver enhancement after TIPS.Pathology showed that liver congestion and hepatocyte swelling improved with time after TIPS placement.CONCLUSION TIPS may achieve better outcomes than conventional symptomatic treatment in patients with PA-HSOS.

Novel roles of lipopolysaccharide and TLR4/NF-κB signaling pathway in inflammatory response to liver injury in Budd-Chiari syndrome

BACKGROUND Budd-Chiari syndrome(BCS)is an uncommon disorder characterized by obstruction of hepatic venous outflow.To date,the exact mechanism underlying hepatic injury derived from the hepatic venous outflow obstruction in BCS remains largely unknown.AIM To assess the role of NF-κB-mediated inflammation in BCS-induced liver injury in humans and rats.METHODS A total of 180 rats were randomly assigned into nine groups,including four BCS model groups(1,3,6 and 12 wk),four sham-operated groups(1,3,6 and 12 wk),and a control group.Lipopolysaccharide(LPS)levels in each group were detected by the Tachypleus Amebocyte Lysate assay.The mRNA and protein levels of TLR4,NF-κB,tumor necrosis factor(TNF)-α,interleukin(IL)-2 and interferon(IFN)-γwere quantified.In addition,60 patients with BCS and 30 healthy controls were enrolled,and their blood samples were analyzed.RESULTS Hepatic and plasma LPS levels were significantly increased in rats.The mRNA and protein expression levels of TLR4,NF-κB and inflammatory cytokines(TNF-α,IL-2 and IFN-γ)in liver tissues were significantly higher in the BCS model groups compared with the other two groups.In addition,the model groups(1,3,6 and 12 wk after BCS induction)showed significant differences in the levels of LPS,TLR4,NF-κB,TNF-α,IL-2 and IFN-γ.Notably,there was a significant correlation between the LPS concentrations and mRNA and protein levels of TLR4,NF-κB and inflammatory cytokines.Importantly,it was revealed that the levels of LPS,TLR4,NF-κB and inflammatory cytokines were significantly greater in chronic BCS patients than healthy controls and acute BCS patients.CONCLUSION LPS level is markedly elevated in BCS,in turn activating the TLR4/NF-κB signaling pathway,leading to induction of inflammatory cytokines(TNF-α,IL-2 and IFN-γ)in response to BCS-induced liver injury.

Contributory roles of sarcopenia and myosteatosis in development of overt hepatic encephalopathy and mortality after transjugular intrahepatic portosystemic shunt

BACKGROUND Skeletal muscle abnormalities,such as muscle mass depletion(sarcopenia)and fatty infiltration of the muscle(myosteatosis),are frequent complications in cirrhotic patients scheduled for transjugular intrahepatic portosystemic shunt(TIPS).AIM To investigate the association and predictive value of sarcopenia and myosteatosis for overt hepatic encephalopathy(HE)and mortality after TIPS.METHODS The records of cirrhotic patients who underwent the TIPS procedure at our hospital between January 2020 and June 2021 were retrospectively retrieved.The transversal psoas muscle thickness(TPMT)and psoas muscle attenuation(PMA)measured from the unenhanced abdominal computed tomography(CT)at the level of the third lumbar vertebrae were used to analyze the sarcopenia and myosteatosis,respectively.The area under curve(AUC)was used to evaluate the discriminative power of TPMT,PMA,and relevant clinical parameters.Furthermore,log-rank test was performed to compare the incidence of overt HE and survival between the different groups,and the association of risk factors with overt HE and mortality was analyzed using Cox proportional hazards regression models.RESULTS A total of 108 patients were collected.Among these patients,45.4%of patients developed overt HE after TIPS treatment.Furthermore,32.4%and 28.7%of these patients were identified to have myosteatosis and sarcopenia,respectively.Myosteatosis(51.0%vs 16.9%,P<0.001)and sarcopenia(40.8 vs 18.6%,P=0.011)were found to be more frequent in patients with overt HE,when compared to patients without overt HE.The receiver operating characteristics analysis indicated that the predictive power of TPMT and PMA in overt HE(AUC=0.713 and 0.778,respectively)was higher when compared to the neutrophil lymphocyte ratio(AUC=0.636).The cumulative incidence of overt HE was the highest in patients with concomitant sarcopenia and myosteatosis,followed by patients with myosteatosis or sarcopenia,while this was the lowest in patients without sarcopenia and myosteatosis.In addition,sarcopenia and myosteatosis were independently associated with overt HE and mortality after adjusting for confounding factors in post-TIPS patients.CONCLUSION CT-based estimations for sarcopenia and myosteatosis can be used as reliable predictors for the risk of developing overt HE and mortality in cirrhotic patients after TIPS.

经颈静脉肝组织活检术的临床应用

背景肝组织活检在急性或慢性肝病的诊断与治疗中仍然扮演着非常重要的角色.虽然经皮肝穿刺活检已经广泛应用于临床,但对于经皮肝脏穿刺活检存在禁忌的患者,经颈静脉肝组织活检术(transjugular liver biopsy,TJLB)更是一种安全有效的替代手段.TJLB虽然在国外早已普遍开展,但在国内由于器械的原因,仅可见少数几家医院有相关报道.目的对行经皮肝穿刺活检术存在禁忌或高危危险因素的患者,使用COOK公司生产的LABS 100肝内穿刺活检针行经颈静脉肝组织穿刺活检术的安全性及可行性.方法回顾性分析2019-11/2020-03于我院行TJLB的15例患者的临床资料,包括适应症、手术成功率、并发症及取样结果等,并对其归纳总结.结果15例患者手术成功率为100%,并发症发生率6.7%,且全部患者均取得足够肝组织并获得病理学诊断.结论对于不宜行经皮肝穿刺活检患者,TJLB术是可行且安全有效的手段,虽然目前TJLB在国外已广泛开展,但国内开展甚少.