人参内生菌的研究进展

内生菌由细菌、真菌、古菌和原生生物组成，它们生活在植物的活体组织中，具有丰富的次级代谢产物多样性。人参内生菌在人参的生长发育、次级代谢产物的生成和环境适应等方面均有重要的促进作用，对人参的产量和品质有较大影响。随着人们在微生物领域研究的深入，高通量测序技术已经成为研究植物内生菌的重要方法。文章主要从人参内生菌分离与鉴定研究方法、人参内生菌的多样性、人参内生菌及其次级代谢产物的活性、人参内生菌对宿主的影响等4个方面对人参内生菌近年来的研究进展进行讨论，并对其发展方向提出展望，以期为药用植物内生菌研究和品质改良提供新思路、新方法。     

基于18SrRNA序列的云南大叶千斤拔与细叶千斤拔根内丛枝菌根真菌鉴定

目的:调查云南省大叶千斤拔(Flemingia macrophylla)与细叶千斤拔(Flemingia lineata)根内丛枝菌根真菌(Arbuscular Mycorrhizal Fungi,AMF)群落结构多样性。方法:使用巢式-PCR、克隆、限制性片段长度多态性(Restriction Fragment Length Polymorphism,RFLP)分析及测序技术。结果:共获得558个含有丛枝菌根真菌18S rRNA片段的克隆子,经RFLP分析后得到83个RFLP类型,DNA序列分析可将其划分为23个可操作分类单元(Operational Taxonomic Units,OTUs),分属于5个科,Glomeraceae为优势类群。在MaarjAM数据库中进行比对后,23个OTUs可鉴定为18个虚拟分类分子种,分布于13种不同的生境。经统计分析大叶千斤拔与细叶千斤拔根内丛枝菌根真菌群落组成比较,差异有统计学意义(P<0.001)。结论:比较大叶千斤拔与细叶千斤拔根内丛枝菌根真菌群落差异,结合丛枝菌根真菌在生态系统中的分布特点,为种植千斤拔属植物的选址提供有力地环境指标数据,并为筛选促生菌株提供依据。     

Evolving Beyond the World Foods Course: Creating Racially and Ethnically Inclusive Educational Spaces for Dietetics Students

Only 13.1% of US registered dietitian nutritionists and 27.8% of students enrolled in US dietetics education programs identify as racially/ethnically diverse individuals. National demographic trends show increasing percentages of racially/ethnically diverse individuals within the broader US and college student populations; however, these changes have not been mirrored within dietetics. Dietetics educators have an ethical and professional mandate to address diversity, equity, and inclusion within their programs. This paper reviews key terminology related to diversity, equity, and inclusion in the context of dietetics education, and describes a new framework to transform dietetics education based on the principles of cultural humility and culturally sustaining teaching. Strategies are presented to facilitate recruitment, admissions, retention, and mentorship for racially/ethnically diverse students and faculty, and to improve diversity, equity, and inclusion within curricula and classrooms. Lastly, this paper provides clear practice applications, including recommendations for program policy change and training/skill building activities for dietetics students, educators, and preceptors.     

学龄儿童肥胖与肠道菌群多样性及菌属丰度的关联研究

目的分析学龄肥胖儿童和正常体重儿童肠道菌群多样性差异, 识别肥胖儿童肠道特征菌属, 为后续相关机制研究和学龄儿童肥胖的防治提供依据。方法基于2016年在上海市嘉定区某小学建立的研究队列人群, 将2016-2018年3年均处肥胖状态的儿童共63名纳入肥胖组, 其中男生43名, 女生20名。在3年均为正常体重的儿童中, 根据年龄、性别和所在班级, 将其与肥胖组儿童进行1∶1匹配, 共选择63名纳入对照组。采用问卷收集儿童基本信息、饮食状况、母乳喂养等情况, 收集两组儿童的粪便样本并进行16S rDNA测序。对质量优化后的测序序列按照97%相似性进行可操作分类单元聚类及物种注释。分析肥胖组和对照组儿童肠道菌群多样性及菌属丰度差异。计算肠道菌群的Ace、Chao1、Shannon、Simpson 4种α多样性指数, 并利用主坐标分析, 在非加权Unifrac距离和加权Unifrac距离的基础上表示β多样性。使用相似性分析(ANOSIM)比较两组β多样性的差异。利用STAMP软件挑选出两组儿童共有菌属中的差异细菌, 并利用广义线性模型(GLM)分析肥胖与α多样性以及显著差异菌属的关联。结果肥胖组...     

Variability of the immunoglobulin light chain in the Siberian sturgeon, Acipenser baeri

All sturgeon VL segments isolated in this study belong to a single family, VLI, which can be divided into two subfamilies. Of the 79 cDNA clones isolated, 76 belong to the larger subfamily, VLIa, and only 3 clones constitute the smaller subfamily, VLIb. To evaluate variability, the Shannon entropy was estimated for each individual amino acid position, and to facilitate comparisons of variability between species the mean entropy of the CDR regions was calculated. In such a comparison, the sturgeon was found to have CDR1 and CDR3 variability approaching those found in mouse and clawed frog, but showed very low variability for CDR2. Amino acid position 50 does however display variability in the range of mouse and clawed frog. It is further confirmed that the sturgeon has numerous J segments, but that the junctional diversity does not contribute greatly to the diversity of the light chain. Comparisons of cDNA clones and a genomic VL segment indicate that the VL undergoes changes, particularly in the CDR regions, in a manner that can be explained by somatic hypermutation and/or gene conversion.     

贵州南部地区苗族、畲族和汉族头面部形态特征调查

目的:了解贵州南部地区苗族、畲族、汉族人群头面部形态特征。方法:采取整群抽样方法,对苗族548人(男290人,女258人),畲族332人(男173人,女159人),汉族528人(男290人,女238人)的头面部28项指标进行活体观察和比较。结果:三个民族的头面部形态特征既有许多相同之处,又有各自不同的特点。结论:贵州南部地区苗族、畲族、汉族人群头面部形态特征具有丰富的多样性,这些特征对探讨贵州少数民族起源及其渊源关系具有重要意义。     

尘肺诊断读片差异分析

目的通过尘肺诊断读片差异分析,提高尘肺诊断水平.方法采用个体读片方式,对其在尘肺期别,小阴影形态、密集度及分布范围的读片差异进行统计分析.结果无尘肺0 的读片差异最大,诊断年限5年以下组对Ⅰ期尘肺诊断的正确率明显低于20年以上组,在小阴影密集度及分布范围的判断上,诊断年限5年以下组明显低于其他组,影像专业组则明显高于其他专业组.结论对低年资的诊断人员要加强读片训练,非影像专业人员有必要进行胸部影像学培训,集体诊断仍是必须的.     

Cultural–Ecological Theory of Academic Disengagement Used to Explain a Story of Race,Culture and Education

Students of African ancestry often share an experience of being a racialized minority in the context of the educational institution. Late Professor of Anthropology John Ogbu’s Cultural-ecological Theory of Academic Disengagement is employed to describe the negative responses encountered by peers in the name of academic achievement.The late Nigerian-American anthropologist John Ogbu described that it is often socially disadvantageous for black youth to prosper academically in formal education. Black students are often seen as betraying their cultural identities by aspiring to academic success and scholastic achievement and are met with repugnance by black peers.The notion of “acting white” is unnecessary, impertinent should be abandoned outright as achievement should have no color.