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Before the antibiotic’s era, the clinicians have shown the relation between epididymitis and Infertility. At the moment, venerial diseases are the principal cause of Epididymitis by the young man. The early diagnosis of the urethral infection (acute or not) associated with a suitable antibiotherapy will allow to protect the fertility.  相似文献   

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著名生态学家H.T.Odum 教授应中国科学院沈阳应用生态研究所邀请,于1990年8月19日至21日来所访问,陪同来访的还有台北中兴大学城市规划研究所所长黄书礼教授。Odum 教授现  相似文献   

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Towner , Joseph W. (U. California, Los Angeles.) Cytogenetic studies on the origin of Tagetes patula. I. Meiosis and morphology of diploid and allotetraploid T. erecta × T. tenuifolia. Amer. Jour. Bot. 48 (9): 743–751. Illus. 1961.—Cytological and morphological evidence is presented to show that Tagetes patula L. is an allotetraploid species (2n = 48) which probably originated by hybridization between the diploids T. erecta L. and T. tenuifolia Cav., or species closely related to them. The putative parent species are separated by strong reproductive isolation barriers, and controlled crosses between them yielded very few good seed. Most of the hybrid seedlings died before reproductive age, and the few survivors were sterile and extremely weak. At meiosis in the diploid hybrid, bivalent frequency per cell was 0–11 and averaged 4.4. Although 43.6% of the quartet stage consisted of restitution dyads, pollen was essentially all non-viable and seed set was less than 1%. A true-breeding, fertile, allotetraploid T. erecta-tenuifolia was synthesized by colchicine-doubling of the chromosome number of the F1 hybrid. In the synthetic allotetraploid, average chromosomal association was 23.97 bivalents plus 0.05 univalents, and 97.4% of MI cells had 24 bivalents; there were no multivalents, bridges, or fragments. Tagetes erecta-tenuifolia showed a striking morphological similarity to T. patula. Both the natural and synthetic allotetraploids were intermediate between T. erecta and T. tenuifolia for nearly every character. Of 10 species of Tagetes whose chromosome numbers are known, 5 are tetraploid (2n = 48).  相似文献   

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著名植物生态生理学家、美国威斯康星大学教授、人工气候室主任T.T.Kozlowsky应植物生理所邀请来华讲学。于5月7—8日在北京作了林木的生长特性和大气污染对树木的影响等二个报告。13—15日在上海作了树木的水分生理,大气污染对树木的影响和人工气候室的使用与管理等三个报告。在上海时,并与植生所环境生理组全体工作人员以及来自各  相似文献   

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H. T. 奥德姆与中国的能值研究   总被引:2,自引:0,他引:2  
简要论述了由霍华德.汤姆.奥德姆创立的能值理论与方法在中国的传播并综述了多年以来中国的能值研究进展。能值理论与方法在中国的传播始于1990年霍华德·汤姆·奥德姆第二次访华.在此期间,即1990年8月1日至1990年8月21日他访问了台北、广州、北京和沈阳,并作了多个学术报告,如“自组织与系统生态学”和“能值分析与环境评价”等。从此以后,我国的广州、北京、南京和沈阳、佛山等多座城市的大学和科研机构先后开展了10多年的能值研究,能值理论应用于多个领域,包括国家、省、市、自然保护区等生态经济系统的能值评估、农业生态系统、城市生态系统、环境与资源、废水处理、生态工程和工业的能值评价。用中文或英文发表关于能值的学术论文60多篇,由霍华德.汤姆.奥德姆所著的3本关于能值的书被翻译为中文,能值概念、理论和方法被10多部中文书刊引用,2本关于能值的中文专著已发表。能值分析的研究工作已得到国家自然科学基金资助,其中有些课题已结题,有些课题正在进行中。能值理论与方法已被许多中国生态学家所接受,但在应用过程中仍存在许多问题。  相似文献   

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关于兰科Eulophia hirsuta T. P. Lin的归属问题   总被引:1,自引:1,他引:0  
根据花的构造将短毛美冠兰Eulophia hirsuta 移入粉口兰属Pachystoma。由于粉口兰属已经有Pachystoma hirsutum(1987),故另起新名,即绿岛粉口兰Pachystoma ludaoense。  相似文献   

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李鹤  孙芳义 《生物技术》1992,2(4):43-43,24
(一)吸附剂1.炉灰渣和黄土按照规定的要求进行烘干,粉碎、过筛20—40目2.炉灰渣和黄土之间的配比为7:3(重量比)炉灰渣和黄土按配比称重后一定要混匀.3.B·T乳液按喷雾筛孔径进行过滤,按规定的质量标准和用量(10%)向吸附剂上喷雾,一定将吸附剂和B·T乳液拌匀.(二)烘干  相似文献   

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An examination of the holotype of Polyalthia pingpienensis P. T. Li has shown that the holotype is an admixture. The branch and the flower on the sheet should be referred to P. plagioneura Diels,whereas the detached leaf belongs to another species,whose i  相似文献   

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T. H. Huxley was “Darwin’s bulldog,” and took the offensive in championing the cause of evolution against skeptical scientists and outraged theologians. As such, he took part in one of the great “paradigm shifts” of biology, at the end of the nineteenth century. Huxley was a rigorous scientist and wrote important articles on scientific method, as well as publishing extensively on a wide range of subjects in natural history. In the second half of the twentieth century, the “prion hypothesis” was put forward to explain the pathogenesis of a curious group of diseases known as the transmissible spongiform encephalopathies. This also involved a “paradigm shift” because the prion hypothesis postulated that biologically relevant information could be enciphered in protein conformation (rather than encoded in nucleic acid base sequences), and could be transmitted from one molecule to another, thereby causing infectious disease. This article examines a few of Huxley’s remarks to speculate on how he might have responded to the scientific debate about prion disease had he lived a century later.  相似文献   

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Alpinia jianganfeng T.L.Wu is conspecific with A.sichuanensis Z.Y. Zhu,and thus is reduced to synonymy.  相似文献   

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