Does ergogenic effect of caffeine supplementation depend on CYP1A2 genotypes? A systematic review with meta-analysis

Background:The ergogenic effects of caffeine intake on exercise performance are well-established,even if differences exist among individuals in response to caffeine intake.The genetic variation of a specific gene,human cytochrome P450 enzyme 1A2(CYP1A2)(rs762551),may be one reason for this difference.This systematic review and meta-analysis aimed to comprehensively evaluate the influence of CYP1A2 gene types on athletes’exercise performance after caffeine intake.Methods:A literature search through 4 databases(Web of Science,PubMed,Scopus,and China National Knowledge Infrastructure)was conducted until March 2023.The effect size was expressed as the weighted mean difference(WMD)by calculating fixed effects meta-analysis if heterogeneity was not significant(I^(2)≤50%and p≥0.1).Subgroup analyses were performed based on AA and AC/CC genotype of CYP1A2.Results:The final number of studies meeting the inclusion criteria was 12(n=666 participants).The overall analysis showed that the cycling time trial significantly improved after caffeine intake(WMD=-0.48,95%confidence interval(95%CI):-0.83 to-0.13,p=0.007).In subgroup analyses,acute caffeine intake improved cycling time trial only in individuals with the A allele(WMD=-0.90,95%CI:-1.48 to-0.33,p=0.002),but not the C allele(WMD=-0.08,95%CI:-0.32 to 0.17,p=0.53).Caffeine supplementation did not influence the Wingate(WMD=8.07,95%CI:-22.04 to 38.18,p=0.60)or countermovement jump test(CMJ)performance(WMD=1.17,95%CI:-0.02 to 2.36,p=0.05),and these outcomes were not influenced by CYP1A2 genotype.Conclusion:Participants with the CYP1A2 genotype with A allele improved their cycling time trials after caffeine supplementation.However,compared to placebo,acute caffeine supplementation failed to increase the Wingate or CMJ performance,regardless of CYP1A2 genotype.

Research and Application Progress of Silk Fibroin Membranes

This paper mainly introduced the preparation of silk fibroin membranes and their structural change characteristics.Silk fibroin membranes can be used as tissue engineering materials,enzyme-immobilizing membranes,biosensors and drug controlled-release membranes and other different materials.They have excellent characteristics such as non-toxic,non-polluting and degradable,and thus have broad application prospects.

Feasibility of DNA Barcoding for Definition of Forage Mulberry

The planting and afforestation of mulberry and its application as animal feed conform to the spirit that comprehensive utilization of biomass such as agriculture and forestry is the direction of sustainable development in the National Program for Medium-to-Long-Term Scientific and Technological Development . The application of mulberry as animal feed has attracted international attention, but the cultivar identification of forage mulberry is still controversial in the industry. The paper summarizes the current situation of forage mulberry in animal husbandry, and expounds how to define and classify forage mulberry.

Silk Nerve Conduits for Peripheral Nerve Regeneration

Silk can promote the penetration of oxygen and water and support the attachment and proliferation of neurons and Schwann cells,and has appropriate biodegradation kinetics and flexible physical strength.It is a high-quality natural tissue engineering material and can be used as an ideal matrix for nerve repair.This paper reviewed the structure and properties of silk and the research progress of silk nerve conduits in peripheral nerve regeneration in recent years,and prospected its clinical application.

Technical Methods for Recovering Sericin from Degumming Wastewater

Silk sericin is a natural polymer,which is often discarded as waste in silk reeling production.Sericin protein increases the COD value of degumming wastewater and increases the difficulty of sewage treatment.The recovery and utilization of sericin protein can minimize environmental problems,and has high scientific and commercial value.This paper introduced and analyzed current technical methods of recycling sericin from silk degumming wastewater,providing a reference for the utilization of recovered sericin.

Tailoring surface features and pore structure by carbon spiral fibers to construct the high-strength carbon foams for the fast and cyclic photo-thermal oil absorption

Two key limitations affecting the commercial application of carbon foams for fast clean-up of varied oils are the complex synthesis process and poor mechanical stability.In this work,an effective method is reported to fabricate the efficient oil-absorbing materials(CSF@MCF)of carbon spiral fibers(CSFs)anchored on melamine carbon foam(MCF)with superior mechanical properties and excellent photothermal con-version.The interwoven CSFs can not only provide extra rigidity but also reduce the stress concentration of the carbon skeleton,which greatly improves the mechanical properties with 6.3 times maximum compression stress and 4.5 times ultimate tensile strength than MCF.In addition,the pure carbon component can reduce the interface resistance and excite the free electrons more easily,thus realizing high-efficiency photothermal conversion in a wide range of wavelengths.Under light irradiation,the CSF@MCF can be quickly heated up to 70℃and achieve ultra-high absorption of crude oil,up to 62 g g_(-1),due to its low density and large absorption volume.Meanwhile,the CSF@MCF exhibits impressive absorption stability with persistent superhydrophobicity and a high recovery efficiency of over 85%.Superadding its simple preparation process,low production cost,and excellent acid-alkali resistance,the CSF@MCF shows great commercial potential for effectively absorbing varied oils.

基于可培养方法分析云南腾冲小空山火山谷芽胞杆菌分布特征

【目的】为了解云南腾冲小空山火山谷土壤中可培养芽胞杆菌种类分布特征。【方法】采用可培养手段对小空山火山谷阳坡、谷底和阴坡土壤中的芽胞杆菌进行分离培养,根据16S rRNA基因序列同源性对分离菌株进行鉴定,并分析系统发育地位。利用Canoco5软件分析采样点芽胞杆菌种类分布特征与土壤样品理化性质的相关性。【结果】从火山谷土壤样品中共分离获得180株芽胞杆菌,16S rRNA基因测序鉴定结果表明分离菌株隶属于芽胞杆菌纲2个科(芽胞杆菌科和类芽胞杆菌科)、6个属、34个种,其中芽胞杆菌属(Bacillus) 11个种,类芽胞杆菌属(Paenibacillus) 14个种,短芽胞杆菌属(Brevibacillus)3个种,赖氨酸芽胞杆菌属(Lysinibacillus)4个种,嗜冷芽胞杆菌属(Psychrobacillus)1个种和绿芽胞杆菌属(Viridibacillus)2个种,其中7个菌株与其最近模式菌株16SrRNA相似性低于种的界定阈值(98.65%),为芽胞杆菌潜在新物种。优势属为芽胞杆菌属和类芽胞杆菌属,优势种为蕈状芽胞杆菌(Bacillusmycoides),图瓦永芽胞杆菌(Bacillustoyonensis),蜡状芽胞杆菌(Bacilluscereus),解木糖赖氨酸芽胞杆菌(Lysinibacillusxylanilyticus),蜂房类芽胞杆菌(Paenibacillusalvei)和沙地绿芽胞杆菌(Viridibacillus arenosi)。其中16个种分离自阳坡,29个种分离自阴坡,9个种分离自谷底,三者共同种类为6种。阳坡、谷底和阴坡的芽胞杆菌种群分布Bray-Curtis相似性为62.4%,多样性分析结果表明,Shannon指数(H′)大小次序为阴坡>阳坡>谷底。环境因子分析发现,芽胞杆菌种群分布多样性特征与其土壤的海拔高度、碳氮比和硫含量呈负相关,而和碳源和氮源含量呈正相关。【结论】从以上结果得出,云南腾冲火山谷有着较为丰富的芽胞杆菌资源,且还存在可分离培养的芽胞杆菌的潜在新物种,为利用火山微生物资源提供了保障。