全文获取类型
收费全文 | 3169篇 |
免费 | 261篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 137篇 |
妇产科学 | 87篇 |
基础医学 | 361篇 |
口腔科学 | 79篇 |
临床医学 | 325篇 |
内科学 | 600篇 |
皮肤病学 | 51篇 |
神经病学 | 162篇 |
特种医学 | 517篇 |
外科学 | 391篇 |
综合类 | 98篇 |
预防医学 | 232篇 |
眼科学 | 16篇 |
药学 | 211篇 |
1篇 | |
肿瘤学 | 156篇 |
出版年
2023年 | 23篇 |
2021年 | 45篇 |
2020年 | 28篇 |
2019年 | 41篇 |
2018年 | 55篇 |
2017年 | 42篇 |
2016年 | 33篇 |
2015年 | 41篇 |
2014年 | 68篇 |
2013年 | 84篇 |
2012年 | 88篇 |
2011年 | 87篇 |
2010年 | 87篇 |
2009年 | 95篇 |
2008年 | 100篇 |
2007年 | 118篇 |
2006年 | 126篇 |
2005年 | 99篇 |
2004年 | 86篇 |
2003年 | 83篇 |
2002年 | 87篇 |
2001年 | 79篇 |
2000年 | 71篇 |
1999年 | 66篇 |
1998年 | 94篇 |
1997年 | 90篇 |
1996年 | 107篇 |
1995年 | 92篇 |
1994年 | 54篇 |
1993年 | 79篇 |
1992年 | 40篇 |
1991年 | 49篇 |
1990年 | 76篇 |
1989年 | 89篇 |
1988年 | 62篇 |
1987年 | 80篇 |
1986年 | 70篇 |
1985年 | 85篇 |
1984年 | 59篇 |
1983年 | 52篇 |
1982年 | 34篇 |
1981年 | 39篇 |
1980年 | 50篇 |
1979年 | 28篇 |
1978年 | 36篇 |
1977年 | 40篇 |
1976年 | 37篇 |
1975年 | 39篇 |
1973年 | 25篇 |
1970年 | 23篇 |
排序方式: 共有3439条查询结果,搜索用时 0 毫秒
21.
22.
23.
Characteristics of motile curved rods in vaginal secretions 总被引:7,自引:0,他引:7
M S Sprott H R Ingham R S Pattman R L Eisenstadt G R Short H K Narang P R Sisson J B Selkon 《Journal of medical microbiology》1983,16(2):175-182
Motile curved rods seen in vaginal secretions have been isolated on Columbia agar supplemented with 5% human blood and vitamin K. Growth occurred anaerobically and in 5% oxygen but not in more aerobic conditions. There were two distinct groups of these organisms, distinguishable by morphology, biochemical activity and susceptibility to metronidazole. All isolates were sensitive to a wide range of antimicrobial agents, with the exception of nalidixic acid and polymyxin, but one group was resistant to metronidazole. There was little difference between the results of tests of susceptibility to aminoglycosides or to metronidazole performed in anaerobic and microaerophilic conditions. Motile curved rods were isolated from 18 of 80 patients with a clinical diagnosis of non-specific vaginitis, but from only two of 39 without the disease. 相似文献
24.
25.
Anderson RA; Wallace AM; Kicman AT; Wu FC 《Human reproduction (Oxford, England)》1997,12(8):1657-1662
Administration of supraphysiological doses of testosterone to normal men
causes inhibition of spermatogenesis, but while most become azoospermic,
30-55% maintain a low rate of spermatogenesis. We have investigated whether
there are differences in endogenous androgen production, of testicular and
adrenal origin, which may be related to the degree of suppression of
spermatogenesis. Thirty-three healthy Caucasian men were given weekly i.m.
injections of 200 mg testosterone oenanthate (TE), 18 became azoospermic,
while 15 remained oligozoospermic. Urinary excretion of epitestosterone, a
specific testicular product, was reduced to <10% of pretreatment values,
with no differences between the groups. Similar results were obtained for
other markers of testicular steroidogenesis. Urinary and plasma adrenal
androgens were also reduced during TE treatment: a statistically
significant decrease in both (P < 0.001 and P < 0.05 respectively)
was seen in the azoospermic but not oligozoospermic responders. These
results suggest that testicular steroidogenesis is decreased to <10% by
the administration of supraphysiological doses of exogenous testosterone.
Differences in the degree of ongoing steroidogenesis in the testis do not
appear to account for incomplete suppression of spermatogenesis, thus
differences in androgen metabolism may underlie this heterogeneous
response. A small but significant reduction in secretion of adrenal
androgens was also detectable, the relevance of which is unclear.
相似文献
26.
Behavioral development during the 1st 5 months of life was observed in 21 group-living mother-reared pigtailed (M. nernestrina) monkey infants. Periodic behavioral observation sessions provided monthly mean scores for 28 different behavioral items. Infants appeared to be separable on several behavioral continua, including their general level of activity and the nature of the mother-infant relationship. Individual differences were prominent, appeared early and persisted. Patterns of behavior were examined and found to be stable across time. Physiological data (heart rate, body temperature, sleep patterns EEG activity) were collected from 15 of the infants at a mean age of 23 weeks using totally implantable multichannel biotelemetry systems. Group mean values and measures of individual variability were obtained for 23 physiological variables. Physiological variables were correlated with each other and measures of concurrent behavior; the following relationships emerged:
27.
28.
RA Kumar 《Clinical genetics》2008,74(4):343-344
De novo mutations in the gene encoding STXBP1 (MUNC18‐1) cause early infantile epileptic encephalopathySaitsu et al. (2008)Nature Genetics 40: 782–788 相似文献
29.
Predominance of null mutations in ataxia-telangiectasia 总被引:15,自引:4,他引:15
Gilad S; Khosravi R; Shkedy D; Uziel T; Ziv Y; Savitsky K; Rotman G; Smith S; Chessa L; Jorgensen TJ; Harnik R; Frydman M; Sanal O; Portnoi S; Goldwicz Z; Jaspers NG; Gatti RA; Lenoir G; Lavin MF; Tatsumi K; Wegner RD; Shiloh Y; Bar-Shira A 《Human molecular genetics》1996,5(4):433-439
Ataxia-telangiectasia (A-T) is an autosomal recessive disorder involving
cerebellar degeneration, immunodeficiency, chromosomal instability,
radiosensitivity and cancer predisposition. The responsible gene, ATM, was
recently identified by positional cloning and found to encode a putative
350 kDa protein with a Pl 3-kinase-like domain, presumably involved in
mediating cell cycle arrest in response to radiation-induced DNA damage.
The nature and location of A-T mutations should provide insight into the
function of the ATM protein and the molecular basis of this pleiotropic
disease. Of 44 A-T mutations identified by us to date, 39 (89%) are
expected to inactivate the ATM protein by truncating it, by abolishing
correct initiation or termination of translation, or by deleting large
segments. Additional mutations are four smaller in-frame deletions and
insertions, and one substitution of a highly conserved amino acid at the Pl
3-kinase domain. The emerging profile of mutations causing A-T is thus
dominated by those expected to completely inactivate the ATM protein. ATM
mutations with milder effects may result in phenotypes related, but not
identical, to A-T.
相似文献
30.