Hydrogen has gradually entered the field of researchers’ vision and clinicians around the world due to its safety， effectiveness， strong permeability， and only water as its metabolites. Hydrogen biomedical research is developing rapidly in recent years. A large number of studies have proved that hydrogen has potential therapeutic effects on more than a hundred diseases including tumors， inflammatory injuries， metabolic diseases， and neurological diseases. During the global outbreak of Corona Virus Disease 2019 （COVID?19） in 2020， hydrogen has also displayed its vast benifits in the adjuvant treatment. This article summarized the animal， cell and clinical research in hydrogen biomedical science， and mainly reviewed the research progress of hydrogen in the fields of metabolic diseases， neurodegenerative diseases， emergency and trauma medicine， and oncology， which was expected to provide reference for hydrogen application research in biomedical science.

Gene therapy refers to the use of gene editing technology to “modify” cell genes to achieve the purpose of treatment. The emergence of CRISPR/Cas provides a simple， efficient and multifunctional platform for gene editing. Meanwhile， in order to overcome the adverse effects caused by DNA double?strand breaks， new technologies based on CRISPR/Cas， such as base editors （BE）， Prime Editors （PE） and Cas13 effector， have been developed one after another. At present， CRISPR/Cas and its derivative editing technologies have been widely used in animal cell model construction， drug target screening and gene function research， and also show broad application prospects in the field of gene therapy. Based on this， CRISPR/Cas and its derivative editing technology were briefly introduced， and their application progress in gene therapy of single gene genetic diseases， tumors and other diseases was summarized. And the challenges they faced at present were analyzed， in order to provide relevant theoretical reference for gene editing in the treatment of single?gene genetic diseases， tumors and other diseases.

Nicotinamide adenine dinucleotide （NAD⁺） is a coenzyme that plays an important role in glycolysis， gluconeogenesis， tricarboxylic acid cycle and respiratory chain. It is widely involved in DNA repair， histone deacetylation and other life processes. In recent years， studies have shown that NAD⁺ substrates and intermediates （molecules with vitamin B3 activity， such as nicotinic acid， nicotinamide， nicotinamide nucleoside and nicotinamide mononucleotide） have many important effects on taking precautions against pellagra， delaying aging， curing diseases such as nerve and cardiovascular diseases， regulating insulin secretion， regulating mRNA expression and so on. This paper reviewed the synthesis and metabolism of coenzyme and the regulation of coenzyme metabolism during the aging process， and provided a theoretical basis and technical support for the enrichment of NAD⁺ intermediates in Escherichia coli and other organisms by synthetic biology.

Aquatorium is an important parts of the earth environments and one of the most vulnerable ecosystems to pollution. The aquatic organisms on different trophic levels are prone to the pollutants in aquatic system via food intake and exposure. Therefore， monitoring the impacts of pollutants in water on aquatic organisms and ecosystems， analyzing the toxicity mechanisms of pollutants on different aquatic organisms， and screening sensitive and effective biomarkers are of great significance for ecotoxicology research and environmental risk assessment. RNA sequencing （RNA?seq） technology has become one of the best methods for aquatic ecotoxicology research， for it can identify gene differential expression at the overall level with less sample volume and with no need of reference sequences. Based on this， the basic process and data analysis process of RNA?seq technology were introduced. Moreover， the application of RNA?seq in ecotoxicology of aquatic organisms with different ecological niches （such as fish， amphibians， shellfish and crustaceans） was reviewed， and the deficiency， challenges and developments trends of RNA?seq technology in toxicology research were also discussed. These were expected to provide reference for the application of RNA?seq technology in aquatic ecotoxicology， especially for the clarification of the mechanism of pollutants on aquatic organisms and the restoration of the ecological environment of pollutant aquatic systems.

China is a typical selenium （Se） deficient country with a saddle Se?deficiency soil belt across Northeast to Southwest， accounting for 33.34% in the main agricultural areas. However， there are also spot?like Se?rich/high areas， accounting for 8.69% in the main agricultural areas， which are widely explored to produce Se?rich agriculture products， such as Enshi/Hubei， Ankang/Shaanxi， Shitai/Anhui， Bama/Guangxi， and Yichun/Jiangxi. Along with the utilization of Se resources， some scientific questions have been widely raised， such as： does Se intake have health effects？ Is there any evidence from the population in natural Se?rich areas？ How is the toxicity of Cd in Se?rich products？ Why should we pay attention to Se speciation rather than total Se contents？ What is the mechanism of Se hyperaccumulation in Cardamine hupingshanensis？ Based on our researches on natural Se resources in recent ten years， the present review provided some perspectives on the above scientific questions and was expected to spot some lights on the efficient and safe utilization of Se resources in the future in China.