甜面酱保温发酵过程中微生物的研究

采用分离计数方法探究甜面酱保温发酵过程中的微生物组成及变化规律,并对优势菌株进行初步分离与鉴定。结果表明:甜面酱保温发酵过程中,细菌数量先上升后下降,霉菌数量则呈下降趋势,未检测出酵母。通过分离获得4株优势霉菌和5株优势细菌,经初步鉴定,其中2株为米曲霉,1株为黑曲霉,1株为根霉,2株为芽孢杆菌属,其余3株分别为假单胞菌属、链球菌属及德克斯氏菌属。生理效价检测结果表明:链球菌属细菌产酸及氨基态氮能力较强,分别为1.2%,0.43%;黑曲霉产糖化酶活力较高,约为352.33U/g,M2米曲霉菌株产蛋白酶活力较高,为53.7U/g。

Nursing students'knowledge,willingness,and attitudes toward the first aid behavior as bystanders in traffic accident trauma:A cross-sectional survey

Objectives:The purpose of the study was to investigate the nursing students'levels of the knowledge,willingness,and attitudes toward first aid behavior as bystanders in road traffic accident and the related factors.Methods:A total of 475 nursing students were recruited by convenience choosing in Tianjin University of Traditional Chinese Medicine.The nursing students'self-efficacy,core self-evaluation,knowledge,willingness and attitudes toward first aid behavior as bystanders in traffic accidents were investigated with a self-designed questionnaire.Results:The scores of knowledge,willingness,and attitudes toward first aid behavior in traffic accident trauma were 7.51±1.93,15.54±5.03,and 7.73±1.56,respectively.Students who once gained training of first aid showed lower levels of attitude toward first aid behavior than those untrained(t=-2.345,P=0.019).It was found that self-efficacy was correlated to the knowledge(r=0.150,P<0.001),willingness(r=0.182,P<0.004)and attitudes toward behavior of the first aid(r=0.371,P<0.001)among nursing students.Core self-evaluation was correlated to knowledge(r=0.193,P<0.001)and attitudes toward behavior of the first aid(r=0.199,P<0.001).Conclusions:The first aid knowledge among nursing students was not satisfactory.The study suggested that an unsustainable short first-aid training program may bring negative effects.Countermeasures should be taken to ensure both quality and continuity of first aid training.Meanwhile,more attention should be paid to improving the self-efficacy and core self-evaluation of the nursing students.

Enzyme Activities in Perfluorooctanoic Acid (PFOA)-Polluted Soils

Perfluorooctanoic acid （PFOA） is a popular additive of the chemical industry; its effect on activities of important soil enzymes is not well understood. A laboratory incubation experiment was carried out to analyze the PFOA-induced changes in soil urease, catalase, and phosphatase activities. During the entire incubation period, the activities of the three soil enzymes generally declined with increasing PFOA concentration, following certain dose-response relationships. The values of EC10, the contaminant concentration at which the biological activity is inhibited by 10%, of PFOA for the soil enzyme activity calculated from the modeling equation of the respective dose-response curve suggested a sensitivity order of phosphatase 〉 catalase 〉 urease. The effect of PFOA on soil enzyme activities provided a basic understanding of the eco-toxicological effect of PFOA in the environment. Results of this study supported using soil ohosohatase as a convenient biomaxker for ecological risk assessment of PFOA-oolluted soils.