The causality between gut microbiome and liver cirrhosis: a bi-directional two-sample Mendelian randomization analysis.

Background and aim: Previous studies have reported an association between gut microbiota and cirrhosis. However, the causality between intestinal flora and liver cirrhosis still remains unclear. In this study, bi-directional Mendelian randomization (MR) analysis was used to ascertain the potential causal effect between gut microbes and cirrhosis. Methods: Large-scale Genome Wide Association Study (GWAS) data of cirrhosis and gut microbes were obtained from FinnGen, Mibiogen consortium, and a GWAS meta-analysis of Alcoholic cirrhosis (ALC). Two-sample MR was performed to determine the causal relationship between gut microbiota and cirrhosis. Furthermore, a bi-directional MR analysis was employed to examine the direction of the causal relations. Result: In MR analysis, we found that 21 gut microbiotas were potentially associated with cirrhosis. In reverse MR analysis, 11 gut microbiotas displayed potentially associations between genetic liability in the gut microbiome and cirrhosis. We found that the family Lachnospiraceae (OR: 1.59, 95% CI:1.10-2.29) might be harmful in cirrhotic conditions (ICD-10: K74). Furthermore, the genus Erysipelatoclostridium might be a protective factor for cirrhosis (OR:0.55, 95% CI:0.34-0.88) and PBC (OR:0.68, 95% CI:0.52-0.89). Combining the results from the MR analysis and reverse MR analysis, we firstly identified the Genus Butyricicoccus had a bi-directional causal effect on PBC (Forward: OR: 0.37, 95% CI:0.15-0.93; Reverse: OR: 1.03, 95% CI:1.00-1.05). Conclusion: We found a new potential causal effect between cirrhosis and intestinal flora and provided new insights into the role of gut microbiota in the pathological progression of liver cirrhosis.

Anticoagulation after transjugular intrahepatic portosystemic shunt for portal hypertension: A systematic review and meta analysis.

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) is widely applied to decrease portal hypertension. Because of the lack of strong evidence, it is controversial whether anticoagulation should be performed after TIPS. This meta-analysis aimed to assess the safety and efficacy of anticoagulation for patients with portal hypertension following TIPS. METHODS: Studies making comparisons between combination treatment and TIPS alone were searched in China National Knowledge Infrastructure, Cochrane Library, PubMed, the Wan Fang electronic databases, and EMBASE, delivered between the earliest accessible date and September 4, 2021. The RevMan version 5.3 was applied to conduct all statistical analyses. I2 index statistic was used to assess heterogeneity. RESULTS: Five eligible studies were selected, and total 707 patients were enrolled. According to the meta-analysis, compared to TIPS alone, TIPS + anticoagulation led to much lower incidence of portal vein thrombosis (PVT; odds ratio [OR] = 0.39, 95% confidence interval [CI] 0.18-0.84, P = .02) as well as low heterogeneity (P = 0.36, I2 = 3%). Other index like the stent dysfunction rate (OR = 1.27, 95% CI 0.71-2.77, P = .42), bleeding rate (OR = 1.27, 95% CI 0.71-2.77, P = .42), and incidence of hepatic encephalopathy (OR = 0.87, 95% CI 0.56-1.36, P = .55) showed no statistical significance. CONCLUSIONS: In certain patients with portal hypertension, anticoagulation following TIPS may not be required. However, for patients who do not have a PVT before TIPS, post-TIPS anticoagulation can decrease the incidence of PVT. Nonetheless, further research is still required.

Beam-Membrane Coupled Piezoelectric Micromachined Ultrasonic Transducers with Enhanced Transmitting Sensitivity.

Piezoelectric micromachined ultrasonic transducers (PMUTs) are a promising alternative to conventional bulk piezoelectric ceramic-based ultrasonic transducers. However, the transmitting sensitivity of the reported PMUTs is far from satisfactory. In this paper, we report a beam-membrane coupled PMUT (BM-PMUT), which enhances the transmitting sensitivity via simultaneously increasing the acoustic emission areas and maintaining the comparable vibration amplitude. Experimental results show that the center and edge transmitting sensitivities of the BM-PMUT are 108.1 and 96 nm/V at 370 kHz, which are 109.9 and 49.6 nm/V at 677 kHz for the traditional PMUT (T-PMUT). Thus, the BM-PMUT realizes piston-like mode shapes and achieves around twofold improvement in the effective acoustic emission area relative to the traditional T-PMUT of the same size. Due to the larger acoustic emission areas and comparable vibration amplitudes, the normalized far-field sound pressure level of the BM-PMUT is 8.5 dB higher than that of the T-PMUT.

Performance evaluation of dual-frequency driving plate ultrasonic motor based on an analytical model.

An analytical model is presented to explain the effects of dual-frequency drive on the plate ultrasonic motor in this paper. The experimental prototype is a plate ultrasonic motor using single-phase asymmetric excitation, which can work under a single vibration or multiple vibration modes. Based on the linear superposition of vibrations with two different excitation frequencies, an analytical model is established using the classic Coulomb friction model, and the non-load rotation speed and maximum stall torque are deduced. Moreover, some crucial parameters such as preload and dead-zone in dual-frequency superposition model are identified or modified automatically by searching for the maximum correlation coefficient between simulation and experimental data using single-frequency drive. It is found that simulation and experiment results agree well when no excitation frequency component is at resonance.