ABSTRACT
Objective:To construct an index system for evaluating the development of research-oriented disciplines in medical institutions, and to provide a basis for guiding the superior disciplines towards international high-level disciplines.Methods:Through literature research and expert discussions, the basic framework of the research-oriented disciplines development evaluation system was established. The final version of the index system was determined using the Delphi method and expert interviews, and the weights of each index were established using the hierarchical analysis method.Results:After consultation, the framework of 5 first-class indexes, 16 second-class indexes, and 51 third-class indexes was finally constructed for the evaluation system of research-oriented discipline development, and the weights of indexes at different classes were calculated. The high-frequency terms " research mechanism construction" , " research team construction" and " representative research results" extracted from the expert interviews echoed the results of the weighting calculation.Conclusions:The evaluation system for research-oriented disciplines constructed in this study is relatively reasonable, scientific, reliable, and operable. The construction of the index system adapts to the characteristics of the development of research-oriented disciplines, with guiding significance for enhancing the development of research-oriented disciplines.
ABSTRACT
With the effective control of viral hepatitis around the world, nonalcoholic steatohepatitis (NASH) will become the main cause of liver transplantation in the next ten years. There is a huge number of NASH patients, but currently no drug has been approved by authorities, which represents a large unmet need in clinical practice. The complex pathogenesis of NASH, heterogeneity of this disease, difficulties in diagnosis, and selection of treatment endpoints have brought great challenges to the research and development of new drugs.
ABSTRACT
Confounding affects the causal relation among the population.Depending on whether the confounders are known,measurable or measured,they can be divided into four categories.Based on Directed Acyclic Graphs,the strategies for confounding control can be classified as (1) the broken-confounding-path method,which can be further divided into single and dual broken paths,corresponding to exposure complete intervention,restriction and stratification,(2) and the reserved-confounding-path method,which can be further divided into incomplete exposure intervention (in instrumental variable design and non-perfect random control test),mediator method and matching method.Among them,random control test,instrumental variable design or Mendelian randomized design,mediator method can meet the requirements for controlling all four types of confounders,while the restriction,stratification and matching methods are only applicable to known,measurable and measured confounders.Identifying the mechanisms of confounding control is a prerequisite for obtaining correct causal effect estimates,which will be helpful in research design.
ABSTRACT
One of the commonly accepted merits of cohort studies (CSs) refers to the exposure precedes outcome superior to other observational designs.We use Directed Acyclic Graphs to construct a causal graph among research populations under CSs.We notice that the substitution of research population in place of a susceptible one can be used for effect estimation.Its correctness depends on the outcome-free status of the substituted population and the performance of both screening and diagnosis regarding the outcomes under study at baseline.The temporal precedence of exposure over outcome occurs theoretically,despite the opposite happens in realities.Correct effect estimate is affected by both the suitability of population substitution and the validities of outcome identification and exclusion.
ABSTRACT
The overall details of causality frames in the objective world remain obscure,which poses difficulty for causality research.Based on the temporality of cause and effect,the objective world is divided into three time zones and two time points,in which the causal relationships of the variables are parsed by using Directed Acyclic Graphs (DAGs).Causal DAGs of the world (or causal web) is composed of two parts.One is basic or core to the whole DAGs,formed by the combination of any one variable originating from each time unit mentioned above.Cause effect is affected by the confounding only.The other is an internal DAGs within each time unit representing a parent-child or ancestor-descendant relationship,which exhibits a structure similar to the confounding.This paper summarizes the construction of causality frames for objective world research (causal DAGs),and clarify a structural basis for the control of the confounding in effect estimate.
ABSTRACT
Confounding affects the causal relation among the population.Depending on whether the confounders are known,measurable or measured,they can be divided into four categories.Based on Directed Acyclic Graphs,the strategies for confounding control can be classified as (1) the broken-confounding-path method,which can be further divided into single and dual broken paths,corresponding to exposure complete intervention,restriction and stratification,(2) and the reserved-confounding-path method,which can be further divided into incomplete exposure intervention (in instrumental variable design and non-perfect random control test),mediator method and matching method.Among them,random control test,instrumental variable design or Mendelian randomized design,mediator method can meet the requirements for controlling all four types of confounders,while the restriction,stratification and matching methods are only applicable to known,measurable and measured confounders.Identifying the mechanisms of confounding control is a prerequisite for obtaining correct causal effect estimates,which will be helpful in research design.
ABSTRACT
One of the commonly accepted merits of cohort studies (CSs) refers to the exposure precedes outcome superior to other observational designs.We use Directed Acyclic Graphs to construct a causal graph among research populations under CSs.We notice that the substitution of research population in place of a susceptible one can be used for effect estimation.Its correctness depends on the outcome-free status of the substituted population and the performance of both screening and diagnosis regarding the outcomes under study at baseline.The temporal precedence of exposure over outcome occurs theoretically,despite the opposite happens in realities.Correct effect estimate is affected by both the suitability of population substitution and the validities of outcome identification and exclusion.
ABSTRACT
The overall details of causality frames in the objective world remain obscure,which poses difficulty for causality research.Based on the temporality of cause and effect,the objective world is divided into three time zones and two time points,in which the causal relationships of the variables are parsed by using Directed Acyclic Graphs (DAGs).Causal DAGs of the world (or causal web) is composed of two parts.One is basic or core to the whole DAGs,formed by the combination of any one variable originating from each time unit mentioned above.Cause effect is affected by the confounding only.The other is an internal DAGs within each time unit representing a parent-child or ancestor-descendant relationship,which exhibits a structure similar to the confounding.This paper summarizes the construction of causality frames for objective world research (causal DAGs),and clarify a structural basis for the control of the confounding in effect estimate.
ABSTRACT
We wished to ascertain the prevalence as well as the genetic and antigenic variation of infectious bronchitis viruses (IBVs) circulating in the Guangxi Province of China in recent years. The S1 gene of 15 IBV field isolates during 2012-2013 underwent analyses in terms of the similarity of amino-acid sequences, creation of phylogenetic trees, recombination, and serologic identification. Similarities in amino-acid sequences among the 15 isolates of the S1 gene were 54.3%-99.6%, and 43.3%-99.3% among 15 isolates and reference strains. Compared with the vaccine strain H120, except for GX-YL130025, the other 14 isolates showed a lower similarity of amino-acid sequences of the S1 gene (65.1-81.4%). Phylogenetic analyses of the S1 gene suggested that 15 IBV isolates were classified into eight genotypes, with the predominant genotype being new-type II. Recombination analyses demonstrated that the S1 gene of the GX-NN130048 isolate originated from recombination events between vaccine strain 4/91 and a LX4-like isolate. Serotyping results suggested that seven serotypes prevailed during 2012-2013 in Guangxi Province, and that only one isolate was consistent with the vaccine strain H120 in serotype (which has been used widely in recent years). The serotype of recombinant isolate GX-NN130048 was different from those of its parent strains. These results suggested that not only the genotype, but also the serotype of IBV field isolates in Guangxi Province had distinct variations, and that increasing numbers of genotypes and serotypes are in circulation. We showed that recombination events can lead to the emergence of new serotypes. Our study provides new evidence for understanding of the molecular mechanisms of IBV variations, and the development of new vaccines against IBVs.