全文获取类型
收费全文 | 8525篇 |
免费 | 595篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 125篇 |
儿科学 | 341篇 |
妇产科学 | 197篇 |
基础医学 | 1084篇 |
口腔科学 | 215篇 |
临床医学 | 632篇 |
内科学 | 2130篇 |
皮肤病学 | 264篇 |
神经病学 | 601篇 |
特种医学 | 555篇 |
外科学 | 1185篇 |
综合类 | 59篇 |
一般理论 | 1篇 |
预防医学 | 657篇 |
眼科学 | 124篇 |
药学 | 454篇 |
1篇 | |
中国医学 | 34篇 |
肿瘤学 | 511篇 |
出版年
2023年 | 39篇 |
2022年 | 30篇 |
2021年 | 196篇 |
2020年 | 109篇 |
2019年 | 211篇 |
2018年 | 261篇 |
2017年 | 184篇 |
2016年 | 207篇 |
2015年 | 222篇 |
2014年 | 305篇 |
2013年 | 415篇 |
2012年 | 466篇 |
2011年 | 503篇 |
2010年 | 351篇 |
2009年 | 385篇 |
2008年 | 443篇 |
2007年 | 471篇 |
2006年 | 468篇 |
2005年 | 455篇 |
2004年 | 368篇 |
2003年 | 390篇 |
2002年 | 324篇 |
2001年 | 164篇 |
2000年 | 204篇 |
1999年 | 202篇 |
1998年 | 153篇 |
1997年 | 171篇 |
1996年 | 154篇 |
1995年 | 104篇 |
1994年 | 104篇 |
1993年 | 129篇 |
1992年 | 90篇 |
1991年 | 76篇 |
1990年 | 91篇 |
1989年 | 98篇 |
1988年 | 77篇 |
1987年 | 69篇 |
1986年 | 73篇 |
1985年 | 69篇 |
1984年 | 44篇 |
1983年 | 34篇 |
1982年 | 31篇 |
1981年 | 43篇 |
1980年 | 29篇 |
1979年 | 16篇 |
1978年 | 17篇 |
1977年 | 29篇 |
1976年 | 27篇 |
1975年 | 16篇 |
1971年 | 13篇 |
排序方式: 共有9170条查询结果,搜索用时 57 毫秒
81.
Nicole Fellmann Mario Bedu Gil Boudet Martine Mage Marcel Sagnol Jean-Marc Pequignot Bruno Claustrat Jocelyne Brun Liliane Peyrin Jean Coudert 《European journal of applied physiology》1992,64(3):258-265
Summary The aim of the study was to investigate the inter-relationships between pituitary-adrenal hormones and catecholamines during a prolonged competition over 6 days. Plasma adrenocorticotropic hormone (ACTH), cortisol (C), -endorphin (EP), free and sulphated adrenaline (A) and noradrenaline (NA) were measured in 11 volunteer male subjects during a national Nordic-ski race (323 km). Blood samples were obtained before the competition in the evening as control (D0), and before and after each day's racing (D1–D6). The mean daily heart rate (f
c) was calculated fromf
c values recorded every minute during the race. The results showed the following: changes in meanf
c [from 147 (SEM 3) to 156 (SEM 3) beats · min–1 according to the day] were not significant during the race. Diurnal variations in ACTH, EP and C were no longer apparent after the race: evening levels were higher than their respective D0 values during the race, except on D3 when there was a lack of response to exercise in the three hormones. Unlike ACTH and EP, pre- and postexercise C values on D1 and D2 were higher than those on the subsequent days (P<0.001). In contrast, there was a progressive accumulation of A and NA in pre-and postrace concentrations which reached a plateau in about 4 days. Positive correlations between exercise responses in ACTH, C and EP were found especially on D3 and D6 (P<0.001) but there were no significant correlations between catecholamines and the other three hormones. Thus, prolonged competition over 6 days evoked different control mechanisms for hormones of the pituitary-adrenal axis and catecholamines. A sustained catecholamine release and sympathetic activation induced a progressive NA and A accumulation during the race. In contrast, the lack of a response to exercise in ACTH, EP and C on D3 suggested a dissociated central command for pituitary axis hormones and sympathetic adrenal activation. On the following days, the response to a lack of exercise, in spite of ACTH stimulation, may have reflected an adaptation of adrenal glands to prolonged stress. 相似文献
82.
Stein TP; Oram-Smith JC; Leskiw MJ; Wallace HW; Long LC; Leonard JM 《The American journal of physiology》1976,230(5):1321-1325
83.
Fever and antipyresis in the lizard Dipsosaurus dorsalis 总被引:2,自引:0,他引:2
84.
Gil LH Alves FP Zieler H Salcedo JM Durlacher RR Cunha RP Tada MS Camargo LM Camargo EP Pereira-da-Silva LH 《Journal of medical entomology》2003,40(5):636-641
Studies on seasonal anopheline fauna variation were performed in two distinct settlements in the State of Rond?nia, Brazil: one at the Madeira River banks (Portuchuelo) with stable native Amazonian population; the other at an inland lumber-extracting farm (Urupá) in dry land, in which adults are mostly migrants. During a 6-yr period (1994-2000), 8,638 adult anophelines were collected: 2,684 in Urupá and 5,954 in Portuchuelo. Anopheles darlingi represented >95% of total mosquitoes caught. Dissection of 4,424 A. darlingi females yielded a very low sporozoite infection index below 0.1%. Oocysts were found in both localities in approximately 0.1% of dissected mosquitoes. Determination of the hour biting rates disclosed seasonal variations in both localities. However, in Portuchuelo, mosquito density peaked at the acme of the rainy season, whereas at Urupá it peaked in the dry season. The increase in mosquito density and incidence of malaria cases were coincident. The high mosquito densities observed in the riverine settlement of Portochuelo sector B, which permits evaluation in > 10,000 mosquitoes' bites/person/year, could explain, in spite of the low mosquito's infection index, the previously described development of natural immunity in the local population that is not observed in the dry land agroindustrial settlement of Urupá. 相似文献
85.
J Gil 《Human pathology》1989,20(3):203-204
86.
The interferons (IFNs) are a family of cytokines with broad antiviral activities that also control cell proliferation and modulate immune responses. IFNs exert their pleiotropic actions through the regulation of multiple pathways that have been subjected to extensive study using diverse approaches. The scope of this review is to show how we can take advantage of vaccinia virus (VV) to study IFN-related pathways. We summarize and present the different VV models available for studying IFN function and the possibilities that they offer to analyze IFN-induced pathways, IFN modulators, and the biologic effects at the molecular and cellular levels. Emphasis is given to studies of dsRNA-activated signaling with VV lacking E3L (VV DeltaE3L) and in RNA-activated protein kinase (PKR)-related pathways, through the use of VV recombinants (VVr) with inducible PKR (VV PKR). The latest system is versatile, as expression of PKR can be regulated and induced at different times; similarly, VVr can be generated expressing other PKR modulators. As an example of the utility of VVr, we describe how this model has been used to analyze the antiviral and proapoptotic functions of PKR, the impact of PKR on translation, and the PKR-induced activation of the nuclear factor-kappaB (NF-kappaB) pathway. 相似文献
87.
N. Casamitjana J. Gil E. Campos M. Santos N. Nogués A. Ribera E. Palou 《Tissue antigens》2001,58(4):269-271
We report here the identification of a novel DQB1*06 allele, DQB1*0618, found in a bone marrow donor. The new allele was detected during routine DNA-based HLA typing by an ambiguous pattern of probe hybridization, obtained by polymerase chain reaction using sequence-specific oligonucleotides (PCR-SSO). Molecular cloning and sequencing confirmed that the new allele is identical to DQB1*0609 at exon 2 except for 3 nucleotide substitutions at positions 353, 356 and 367, also found in other alleles. These nucleotide changes may explain its anomalous reactivity. 相似文献
88.
89.
90.
Vaughan JR; Farrer MJ; Wszolek ZK; Gasser T; Durr A; Agid Y; Bonifati V; DeMichele G; Volpe G; Lincoln S; Breteler M; Meco G; Brice A; Marsden CD; Hardy J; Wood NW 《Human molecular genetics》1998,7(4):751-753
A mutation in exon 4 of the human alpha-synuclein gene was reported
recently in four families with autosomal dominant Parkinson's disease (PD).
In order to examine whether mutations in this exon or elsewhere in the gene
are common in familial PD, all seven exons of the alpha- synuclein gene
were amplified by PCR from index cases of 30 European and American
Caucasian kindreds affected with autosomal dominant PD. Each product was
sequenced directly and examined for mutations in the open reading frame. No
mutations were found in any of the samples examined. We conclude that the
A53T change described in the alpha- synuclein gene is a rare cause of PD or
may even be a rare variant. Mutations in the regulatory or intronic regions
of the gene were not excluded by this study.
相似文献