Stylonema alsidii(Zandardini)Drew f.ramosum Zheng et Li is a common species in the genus Stylonema,but there are limited reports on morphological taxonomy and a lack of studies on life history and the regulation of ea...Stylonema alsidii(Zandardini)Drew f.ramosum Zheng et Li is a common species in the genus Stylonema,but there are limited reports on morphological taxonomy and a lack of studies on life history and the regulation of early development.The early development,discoid formation,and erect thallus growth of Stylonema alsidii f.ramosum were observed under laboratory conditions.In addition,the influence of main environmental factors such as temperature and light intensity on its development was briefly studied,and various stages of its life history were observed.The result shows:(1)there are two reproductive modes:asexual reproduction and sexual reproduction;(2)the morphology of this species varies in different degrees under laboratory culture conditions;(3)sexual reproduction and asexual reproduction can coexist under suitable conditions.Five pathways of life history were inferred from experimental phenomena.Mature sporophytes form mature gametophytes by producing initially isolated or initially attached monospore,and mature gametophytes form mature sporophytes by fertilization of eggs and sperms.The sexual and asexual reproduction processes of Stylonema alsidii f.ramosum were reported for the first time,and this is also the first report on sexual reproduction in the genus Stylonema.展开更多
Even though she’s quite young,Drew Barrymore can already be called a Hollywood legend (传奇).She’s lived it up,and she has enough movies under her belt to put most young stars to shame.
基金Supported by the National Natural Science Foundation of China(Nos.31970216,32270219)。
文摘Stylonema alsidii(Zandardini)Drew f.ramosum Zheng et Li is a common species in the genus Stylonema,but there are limited reports on morphological taxonomy and a lack of studies on life history and the regulation of early development.The early development,discoid formation,and erect thallus growth of Stylonema alsidii f.ramosum were observed under laboratory conditions.In addition,the influence of main environmental factors such as temperature and light intensity on its development was briefly studied,and various stages of its life history were observed.The result shows:(1)there are two reproductive modes:asexual reproduction and sexual reproduction;(2)the morphology of this species varies in different degrees under laboratory culture conditions;(3)sexual reproduction and asexual reproduction can coexist under suitable conditions.Five pathways of life history were inferred from experimental phenomena.Mature sporophytes form mature gametophytes by producing initially isolated or initially attached monospore,and mature gametophytes form mature sporophytes by fertilization of eggs and sperms.The sexual and asexual reproduction processes of Stylonema alsidii f.ramosum were reported for the first time,and this is also the first report on sexual reproduction in the genus Stylonema.
文摘Even though she’s quite young,Drew Barrymore can already be called a Hollywood legend (传奇).She’s lived it up,and she has enough movies under her belt to put most young stars to shame.
文摘Harvard University President Drew Gilpin Faust visited Tsinghua on March 26, 2008 and delivered a speech in theTsinghua Global Vision Lectures series.
文摘目的孤立性肺结节(solitary pulmonary nodule,SPN)的定性诊断十分困难,PET/CT是目前评价良、恶性病变最具优势的影像学手段之一。文中用Meta分析方法综合评价18F-脱氧葡萄糖(18Fluorodexglucose,FDG)PET/CT显像诊断恶性孤立性肺结节的价值。方法以孤立性肺结节、FDG、PET/CT等为检索词,检索1994年1月至2009年7月的Medline数据库、西文生物医学期刊文献服务系统、外文生物医学期刊全文数据库、中国学术期刊网全文数据库等相关中英文文献。对符合标准的研究进行质量评估,用MetaDisc1.4软件进行异质性检验,综合敏感性、特异性和诊断优势比,绘制汇总受试者工作特征(summary receiver operating characteristic,SROC)曲线和计算曲线下面积(the area under the curve,AUC),并进行敏感性分析。结果共检索相关文献29篇,其中11篇符合标准纳入分析,A级1篇,B级10篇,各研究之间存在异质性,按照随机效应模型合并敏感性、特异性、诊断优势比(diagnostic odds ratio,DOR)及其95%可信区间分别为91%(87%~93%)、83%(78%~87%)和51.04(23.33~111.66),AUC为0.9383,Q值为0.875 3,纳入文献稳定性较好。结论 18F-FDG PET/CT显像能灵敏、准确地诊断恶性孤立性肺结节,具有较高的临床应用价值。
