13 research outputs found
Research progress in the expression of versican in malignant tumors and its biological roles
Malignant tumors pose a serious threat to human health and are one of the main causes of human death worldwide. In order to further improve the therapeutic outcomes of malignant tumors and prolong patients' survival time, clarifying the pathogenesis of malignant tumors and searching for new diagnostic and therapeutic targets become particularly important. It has been found that the occurrence and development of malignant tumors are the results of the interaction between tumor cells and the tumor microenvironment (TME). Versican, encoded by the VCAN gene, is a type of chondroitin sulfate proteoglycan belonging to the exogenous lectin proteoglycan family. It is a major component of the extracellular matrix and plays an important role in embryonic development and inflammatory responses. As an important component of TME, versican is abnormally expressed in various tumor tissues such as renal cell carcinoma, hepatocellular carcinoma, and gastric cancer, and is closely related to the clinical pathological characteristics and prognosis of the patients. It is a potential biomarker for early diagnosis and prognostic evaluation of tumors. Further researches have shown that versican can promote tumor development in a number of ways, such as promoting tumor cell proliferation, invasion and metastasis, inhibiting tumor cell apoptosis, promoting tumor angiogenesis, and inhibiting anti-tumor immune responses. This article reviews the current research status of the expression and biological effects of versican in malignant tumors, aiming to provide reference for subsequent research, clinical diagnosis and treatment of tumors
Synthetic test circuit with twoâlevel voltage source for HVDC circuit breakers
Abstract In order to ensure the reliable interruption of high voltage direct current circuit breaker (HVDC CB), the breaking test of HVDC CB plays an important role in its performance verification. In this paper, the interruption process of the HVDC CB is analyzed, and the equivalent requirements for the breaking test of HVDC CB are summarized. In the breaking test of high voltage and high current, the transient interruption voltage (TIV) duration is short, which leads to insufficient voltage stress. A new synthetic test circuit for testing the interruption performance of HVDC CBs is proposed, which can solve the problem of insufficient TIV duration caused by insufficient test capacity. Subsequently, the working principle of the test circuit is introduced in detail and the design method of the circuit parameters is given. The shortâcircuit current breaking test simulation of HVDC CB is carried out. The simulation results fit most well with the results of actual test cases, which verifies the universality of this test method. Finally, a test platform is built to verify the principle of the test circuit. TIV rose to 2.5Â kV compared to the predetermined system voltage of 1.67Â kV during the test, which means that the key stress provided by the test circuit can meet the expected requirements
Hierarchical Porous Carbon Fibers for Enhanced Interfacial Electron Transfer of Electroactive Biofilm Electrode
The nanoporous carbon fiber materials derived from electrospun polyacrylonitrile (PAN) fibers doped with zeolitic imidazolate framework are developed here and applied in the microbe fuel cell anode for enhanced interfacial electron transfer. Zeolitic imidazolate fram-8 (ZIF-8) could introduce a large number of mesopores into fibers, which significantly promote indirect electron transfer mediated by flavins (IET). Moreover, it is noted that thinner fibers are more suitable for cytochromes-based direct electron transfer (DET). Furthermore, the enlarged fiber interspace strengthens the amount of biofilm loading but a larger interspace between thick fibers would hinder the formation of continuous biofilm. Consequently, the nanoporous carbon fiber derived from PAN/ZIF-8 composite with a 1:1 wt ratio shows the best performance according to its suitable mesoporous structure and optimal fiber diameter, which delivers a 10-fold higher maximum power density in microbial fuel cells compared to carbon fabric. In this work, we reveal that the proportion of IET and DET in the interfacial electron transfer process varies with different porous structures and fiber diameters, which may provide some insights for designing porous fiber electrodes for microbial fuel cells and also other devices of bioelectrochemical systems
Hierarchical Porous Carbon Fibers for Enhanced Interfacial Electron Transfer of Electroactive Biofilm Electrode
The nanoporous carbon fiber materials derived from electrospun polyacrylonitrile (PAN) fibers doped with zeolitic imidazolate framework are developed here and applied in the microbe fuel cell anode for enhanced interfacial electron transfer. Zeolitic imidazolate fram-8 (ZIF-8) could introduce a large number of mesopores into fibers, which significantly promote indirect electron transfer mediated by flavins (IET). Moreover, it is noted that thinner fibers are more suitable for cytochromes-based direct electron transfer (DET). Furthermore, the enlarged fiber interspace strengthens the amount of biofilm loading but a larger interspace between thick fibers would hinder the formation of continuous biofilm. Consequently, the nanoporous carbon fiber derived from PAN/ZIF-8 composite with a 1:1 wt ratio shows the best performance according to its suitable mesoporous structure and optimal fiber diameter, which delivers a 10-fold higher maximum power density in microbial fuel cells compared to carbon fabric. In this work, we reveal that the proportion of IET and DET in the interfacial electron transfer process varies with different porous structures and fiber diameters, which may provide some insights for designing porous fiber electrodes for microbial fuel cells and also other devices of bioelectrochemical systems
Genetic Characteristic and Global Transmission of Influenza A H9N2 Virus
The H9N2 virus has been demonstrated to donate its genes to other subtypes of influenza A virus, forming new reassortant virus which may infect human beings. Understanding the genetic characteristic and the global transmission patterns of the virus would guide the prevention and control of potentially emerging avian influenza A virus. In this paper, we hierarchically classified the evolution of the H9N2 virus into three main lineages based on the phylogenetic characteristics of the virus. Due to the distribution of sampling locations, we named the three lineages as Worldwide lineage, Asia-Africa lineage, and China lineage. Codon usage analysis and selective positive site analysis of the lineages further showed the lineage-specific evolution of the virus. We reconstructed the transmission routes of the virus in the three lineages through phylogeography analysis, by which several epicenters for migration of the virus were identified. The hierarchical classification of the lineages implied a possible original seeding process of the virus, starting from the Worldwide lineages to the Asian-Africa lineages and to the China lineages. In the process of H9N2 virus global transmission, the United States was the origin of the virus. China Mainland, Hong Kong SAR, Japan, and Korea were important transfer centers. Based on both the transmission route and the distribution of the hosts in each lineage, we concluded that the wild birds' migration has contributed much to the long-distance global spread of the virus, while poultry trade and people's lifestyle may have contributed to the relatively short-distance transmission in some areas of the Asia and Africa
Bifidobacterium breve predicts the efficacy of antiâPDâ1 immunotherapy combined with chemotherapy in Chinese NSCLC patients
Abstract Background and Purpose Gut microbes play an important role in the occurrence of lung cancer, immunotherapy, and chemotherapy. In this study, we analyzed the characteristics of gut microbes in patients with lung cancer and investigated the effect of gut microbes on antiâPDâ1 therapy combined with chemotherapy. Methods Fecal samples from 21 nonâsmall cell lung cancer (NSCLC) patients and 22 healthy volunteers who were treated in the Fourth Hospital of Hebei Medical University from 2019 to 2021 were collected. DNA was extracted from all samples, and the V3âV4 region of the bacterial 16S rRNA gene was PCRâamplified using the Illumina sequencing platform, and R language was used for data analysis. Results There were significant differences in the Beta diversity and metabolic pathways of gut microbes between NSCLC patients and healthy individuals (pâ<â0.05). Bifidobacterium, Escherichia, and Sarterella were significantly enriched in patients with clinical benefit response (pâ<â0.05), and these three bacteria had certain predictive value for clinical benefit. Patients with Bifidobacterium breve had significantly longer median progressionâfree survival (mPFS) compared with patients with no detectable Bifidobacterium breve feces at baseline (106âdays vs. NR, pâ<â0.001). Multivariate COX analysis showed that the presence of B.breve was an independent good prognostic factor affecting the PFS of patients receiving combination therapy (pâ<â0.05). Conclusion The clinical efficacy of antiâPDâ1 therapy combined with chemotherapy in Chinese advanced NSCLC patients is closely related to the gut microbiota, and Bifidobacterium breve may be a potential biomarker to predict the efficacy of immuneâcombined chemotherapy
Are medical record front page data suitable for risk adjustment in hospital performance measurement? Development and validation of a risk model of in-hospital mortality after acute myocardial infarction
Objectives To develop a model of in-hospital mortality using medical record front page (MRFP) data and assess its validity in case-mix standardisation by comparison with a model developed using the complete medical record data.Design A nationally representative retrospective study.Setting Representative hospitals in China, covering 161 hospitals in modelling cohort and 156 hospitals in validation cohort.Participants Representative patients admitted for acute myocardial infarction. 8370 patients in modelling cohort and 9704 patients in validation cohort.Primary outcome measures In-hospital mortality, which was defined explicitly as death that occurred during hospitalisation, and the hospital-level risk standardised mortality rate (RSMR).Results A total of 14 variables were included in the model predicting in-hospital mortality based on MRFP data, with the area under receiver operating characteristic curve of 0.78 among modelling cohort and 0.79 among validation cohort. The median of absolute difference between the hospital RSMR predicted by hierarchical generalised linear models established based on MRFP data and complete medical record data, which was built as âreference modelâ, was 0.08% (10th and 90th percentiles: â1.8% and 1.6%). In the regression model comparing the RSMR between two models, the slope and intercept of the regression equation is 0.90 and 0.007 in modelling cohort, while 0.85 and 0.010 in validation cohort, which indicated that the evaluation capability from two models were very similar.Conclusions The models based on MRFP data showed good discrimination and calibration capability, as well as similar risk prediction effect in comparison with the model based on complete medical record data, which proved that MRFP data could be suitable for risk adjustment in hospital performance measurement