全文获取类型
收费全文 | 191篇 |
免费 | 19篇 |
专业分类
210篇 |
出版年
2019年 | 2篇 |
2017年 | 6篇 |
2016年 | 9篇 |
2015年 | 12篇 |
2014年 | 10篇 |
2013年 | 7篇 |
2012年 | 7篇 |
2011年 | 7篇 |
2010年 | 10篇 |
2009年 | 8篇 |
2007年 | 8篇 |
2006年 | 3篇 |
2005年 | 9篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 7篇 |
1998年 | 9篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1990年 | 4篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1965年 | 1篇 |
1959年 | 1篇 |
1950年 | 1篇 |
1947年 | 1篇 |
1943年 | 1篇 |
1934年 | 1篇 |
1912年 | 1篇 |
1911年 | 2篇 |
排序方式: 共有210条查询结果,搜索用时 0 毫秒
41.
42.
Warfield Garson 《The Western journal of medicine》1959,91(4):179-184
The limitations and special usefulness of clinical and laboratory diagnostic techniques in the diagnosis of gonorrhea are poorly understood and utilized by the average practitioner today. Most physicians and clinics, lulled by complacency or lack of ancillary aid in the area of diagnosis, proceed by measures based in many instances upon past fallacy rather than upon the facts recently developed by research in this disease. The same circumstances apply concerning treatment and management of this disease, particularly in females.All physicians are potentially capable of giving excellent treatment for syphilis today. The problem is to properly diagnose the disease, manage the patient and deal with the source. Looming large in the area of diagnosis is the interpretation of serologic tests for syphilis. No serologic test diagnoses syphilis, but rather gives information as to the immunologic status of the the patient in relation to reagin and treponemal antibodies. None of the antibodies measured in these tests are absolutely specific for syphilis alone.There is no substitute for a well-informed physician, who knows his patient, to relate and interpret even the best of treponemal serologic tests. 相似文献
43.
Ruis MA de Groot J te Brake JH Dinand Ekkel E van de Burgwal JA Erkens JH Engel B Buist WG Blokhuis HJ Koolhaas JM 《Applied animal behaviour science》2001,70(3):201-225
Endocrine, behavioural and immunologic processes, together with body growth, were evaluated in gilts that were defeated at 10 weeks of age in resident-intruder tests. Immediately after defeat, gilts were either separated from or reunited with a familiar conspecific (litter-mate; always a barrow). Gilts were assigned to one of four treatments: (a) DI: defeat, followed by isolation (separation from original litter-mate; n=8); (b) I: no defeat, isolation (control group; n=9); (c) DP; defeat, followed by pair-housing (reunion with original litter-mate; n=8); and (d) P: no defeat, pair-housing (control group; n=8). The following general conclusions were derived: (1) social defeat caused pronounced short-term elevations in hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenal medullary activities, and of prolactin levels. Moreover, as soon as 1h after defeat, percentages of blood lymphocytes and neutrophilic granulocytes were, respectively, decreased and increased; (2) social defeat had some long-lasting influence on behaviour and physiology, but isolation predominantly determined responses in the longer term. Defeat, as well as isolation, resulted in increased cardiovascular activities compared to P controls, as observed in a novel object test (NOT: +7 days) and an aversion test (AVT: +14 days). Moreover, defeated as well as isolated gilts did not habituate to a repeated novel environment test (NET: -7, +2 and +7 days) in terms of frequencies of vocalising, whereas P controls did. Isolation, through the separation from any other pig, was responsible for the other observed long-term characteristics, which developed progressively. Isolated gilts showed high mobilities and high cortisol responses in the repeated NET (+7 days), not being habituated. This contrasted the reactions of pair-housed gilts, which were much reduced. In addition to their high cardiovascular activities in the NOT and the AVT, isolated gilts also displayed higher heart rates in the repeated NET and during human presence following the NOT, compared to pair-housed gilts. Finally, isolated gilts were more inhibited to approach a novel object (in the NOT) than pair-housed pigs; and (3) stress responses of defeated gilts were modulated by the subsequent social environment. Stimulation of the HPA-axis (plasma- and salivary cortisol) was prolonged in those defeated gilts which were isolated (observed in the first hour). Changes in leucocyte subsets were still observed after 3 days in DI, but were 'normalised' within 1 day in DP gilts. Two days after defeat, habituation to the repeated NET in terms of mobility and salivary cortisol responses occurred in control and DP gilts, but not in DI gilts. We argue that these effects of the social environment shortly after defeat were related to a stress-reducing effect of a stable social relationship, i.e. social support. 相似文献
44.
45.
46.
47.
Gene amplification in mammalian cells commonly manifests itself as homogeneously staining chromosomal regions (HSRs). These are frequently seen in neuroblastoma and have been shown to be the site of amplification of the NMYC oncogene. We have used a nonisotopic, high-resolution in situ hybridization technique to reveal a hitherto unrecognized periodic microstructure within HSRs of a human neuroblastoma cell line. 相似文献
48.
49.
John A Fuerst Richard I Webb Mary J Garson Lani Hardy Henry M Reiswig 《FEMS microbiology letters》1998,166(1):29-34
In thin sections of resin-embedded samples of glutaraldehyde- and osmium tetroxide-fixed tissue from five genera of marine sponges, Stromatospongia, Astrosclera, Jaspis, Pseudoceratina and Axinyssa, cells of a bacteria-like symbiont microorganism which exhibit a membrane-bounded nuclear region encompassing the fibrillar nucleoid have been observed within the sponge mesohyl. The nuclear region in these cells is bounded by a single bilayer membrane, so that the cell cytoplasm is divided into two distinct regions. The cell wall consists of subunits analogous to those in walls of some Archaea. Cells of the sponge symbionts observed here are similar to those of the archaeal sponge symbiont Cenarchaeum symbiosum. 相似文献
50.
Bob?JA?Schijvenaars Barend?Mons Marc?Weeber Martijn?J?Schuemie Erik?M?van Mulligen Hester?M?Wain Jan?A?KorsEmail author 《BMC bioinformatics》2005,6(1):149