全文获取类型
收费全文 | 1367626篇 |
免费 | 105904篇 |
国内免费 | 4317篇 |
专业分类
耳鼻咽喉 | 17057篇 |
儿科学 | 44584篇 |
妇产科学 | 37047篇 |
基础医学 | 202530篇 |
口腔科学 | 36882篇 |
临床医学 | 134040篇 |
内科学 | 264693篇 |
皮肤病学 | 26869篇 |
神经病学 | 114587篇 |
特种医学 | 49567篇 |
外国民族医学 | 366篇 |
外科学 | 188529篇 |
综合类 | 29688篇 |
现状与发展 | 1篇 |
一般理论 | 482篇 |
预防医学 | 118461篇 |
眼科学 | 29674篇 |
药学 | 101687篇 |
6篇 | |
中国医学 | 3227篇 |
肿瘤学 | 77870篇 |
出版年
2021年 | 11351篇 |
2019年 | 12148篇 |
2018年 | 16893篇 |
2017年 | 12690篇 |
2016年 | 13705篇 |
2015年 | 15746篇 |
2014年 | 21504篇 |
2013年 | 33093篇 |
2012年 | 45744篇 |
2011年 | 48405篇 |
2010年 | 27948篇 |
2009年 | 25759篇 |
2008年 | 44181篇 |
2007年 | 46614篇 |
2006年 | 46698篇 |
2005年 | 45066篇 |
2004年 | 42938篇 |
2003年 | 40805篇 |
2002年 | 39570篇 |
2001年 | 61921篇 |
2000年 | 63550篇 |
1999年 | 53337篇 |
1998年 | 15061篇 |
1997年 | 13631篇 |
1996年 | 13482篇 |
1995年 | 12833篇 |
1994年 | 11940篇 |
1993年 | 11289篇 |
1992年 | 42451篇 |
1991年 | 41593篇 |
1990年 | 40218篇 |
1989年 | 38066篇 |
1988年 | 35286篇 |
1987年 | 34427篇 |
1986年 | 32845篇 |
1985年 | 31289篇 |
1984年 | 23621篇 |
1983年 | 20057篇 |
1982年 | 12075篇 |
1979年 | 21227篇 |
1978年 | 15187篇 |
1977年 | 12356篇 |
1976年 | 12186篇 |
1975年 | 12376篇 |
1974年 | 15149篇 |
1973年 | 14786篇 |
1972年 | 13657篇 |
1971年 | 12689篇 |
1970年 | 11747篇 |
1969年 | 10701篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Regula E Egli Thomas L Kash Kevin Choo Valentina Savchenko Robert T Matthews Randy D Blakely Danny G Winder 《Neuropsychopharmacology》2005,30(4):657-668
The bed nucleus of the stria terminalis (BNST) and its adrenergic input are key components in stress-induced reinstatement and maintenance of drug use. Intra-BNST injections of either beta-adrenergic receptor (beta-AR) antagonists or alpha2-adrenergic receptor (alpha2-AR) agonists can inhibit footshock-induced reinstatement and maintenance of cocaine- and morphine-seeking. Using electrophysiological recording methods in an in vitro slice preparation from C57/Bl6j adult male mouse BNST, we have examined the effects of adrenergic receptor activation on excitatory synaptic transmission in the lateral dorsal supracommissural BNST (dBNST) and subcommissural BNST (vBNST). Alpha2-AR activation via UK-14,304 (10 microM) results in a decrease in excitatory transmission in both dBNST and vBNST, an effect predominantly dependent upon the alpha2A-AR subtype. Beta-AR activation via isoproterenol (1 microM) results in an increase in excitatory transmission in dBNST, but not in vBNST. Consistent with the work with receptor subtype specific agonists, application of the endogenous ligand norepinephrine (NE, 100 microM) elicits two distinct effects on glutamatergic transmission. In dBNST, NE elicits an increase in transmission (62% of dBNST NE experiments) or a decrease in transmission (38% of dBNST NE experiments). In vBNST, NE elicits a decrease in transmission in 100% of the experiments. In dBNST, the NE-induced increase in synaptic transmission is blocked by beta1/beta2- and beta2-, but not beta1-specific antagonists. In addition, this increase is also reduced by the alpha2-AR antagonist yohimbine and is absent in the alpha2A-AR knockout mouse. In vBNST, the NE-induced decrease in synaptic transmission is markedly reduced in the alpha2A-AR knockout mouse. Further experiments demonstrate that the actions of NE on glutamatergic transmission can be correlated with beta-AR function. 相似文献
992.
993.
994.
A. Roosaar L. Yin G. Sandborgh-Englund O. Nyrén T. Axéll 《Journal of oral pathology & medicine》2006,35(5):257-261
OBJECTIVES: The aim was to assess the natural course of oral lichen lesions (OLL) among unselected, non-consulting individuals. SUBJECTS AND METHODS: A cohort of 327 subjects with OLL, confirmed in 1973-1974 during a population-based survey in two Swedish municipalities, was followed through January 2002 via record linkages with nationwide and essentially complete registers. A sample of 80 drawn from the 194 surviving subjects who still resided in the area in 1993-1995 was invited for interview and oral re-examination. RESULTS: At the end of follow-up, one case of oral cancer was detected, while 0.4 were expected. The overall mortality among subjects with OLL was not significantly different from that in the 15,817 OLL-free subjects who participated in the initial population based survey in 1973-1974. The lesion had disappeared in 14 (39%) of 36 re-examined subjects with white OLLs in 1973-1974, and four (11%) had transformed into red types. In the corresponding group of 19 with red forms initially, five (26%) had become lesion free and four (21%) had switched to white types. Although the cohort size does not permit firm conclusions regarding oral cancer risk, the natural course over up to 30 years appears to be benign in the great majority. 相似文献
995.
M.L. Raffin-Sanson 《Annales d'endocrinologie》2006,67(6):632-633
996.
997.
998.
Influence of Genetic Variation in the C-Reactive Protein Gene on the Inflammatory Response During and After Acute Coronary Ischemia 总被引:4,自引:0,他引:4
J. Suk Danik D. I. Chasman C. P. Cannon D. T. Miller R. Y. L. Zee P. Kozlowski D. J. Kwiatkowski P. M. Ridker 《Annals of human genetics》2006,70(6):705-716
The aim of this research was to assess whether common genetic variants within the C-reactive protein gene ( CRP ) are related to the degree of acute rise in plasma C-reactive protein (CRP) levels following an acute coronary syndrome (ACS). While polymorphisms within CRP are associated with basal CRP levels in healthy men and women, less is known about the relationship of such genetic variants and the degree of CRP rise during and after acute ischemia. Plasma CRP is associated with increased rates of recurrent coronary events. We evaluated seven common genetic variants within CRP and assessed their relationship to the degree of rise in CRP levels immediately following an acute coronary syndrome in 1827 European American patients. Variants in the putative promoter region, −757T > C and −286C > T > A, were associated with the highest CRP elevations after ACS. Patients with two copies of the A allele of SNP −286C > T > A had median CRP values of 76.6 mg/L, compared to 11.1 mg/L in patients with no copies of the rare variant (p-value <0.0001), post ACS. The lowest CRP values were found for patients with minor alleles of the exonic 1059G > C and the 3'untranslated region 1846G > A SNPs. For example, patients homozygous for the minor allele of 1059G > C had 71% lower median CRP values than those homozygous for the major allele [3.5 vs 12.0 mg/L, p < 0.0001]. These trends persisted in the chronic stable phase after ischemia had resolved, and after adjustment for infarct size by peak creatinine kinase levels and clinical status by Killip class. Assessment of CRP genetic variants identified patients with higher and lower CRP elevation after acute coronary syndrome. 相似文献
999.
1000.