全文获取类型
收费全文 | 3157篇 |
免费 | 164篇 |
国内免费 | 83篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 202篇 |
妇产科学 | 41篇 |
基础医学 | 339篇 |
口腔科学 | 64篇 |
临床医学 | 364篇 |
内科学 | 795篇 |
皮肤病学 | 86篇 |
神经病学 | 131篇 |
特种医学 | 425篇 |
外科学 | 247篇 |
综合类 | 53篇 |
一般理论 | 2篇 |
预防医学 | 180篇 |
眼科学 | 28篇 |
药学 | 187篇 |
2篇 | |
肿瘤学 | 256篇 |
出版年
2023年 | 10篇 |
2022年 | 14篇 |
2021年 | 35篇 |
2020年 | 26篇 |
2019年 | 40篇 |
2018年 | 57篇 |
2017年 | 28篇 |
2016年 | 42篇 |
2015年 | 53篇 |
2014年 | 69篇 |
2013年 | 100篇 |
2012年 | 80篇 |
2011年 | 83篇 |
2010年 | 111篇 |
2009年 | 107篇 |
2008年 | 92篇 |
2007年 | 143篇 |
2006年 | 87篇 |
2005年 | 101篇 |
2004年 | 77篇 |
2003年 | 59篇 |
2002年 | 70篇 |
2001年 | 78篇 |
2000年 | 71篇 |
1999年 | 70篇 |
1998年 | 147篇 |
1997年 | 168篇 |
1996年 | 144篇 |
1995年 | 116篇 |
1994年 | 119篇 |
1993年 | 106篇 |
1992年 | 63篇 |
1991年 | 62篇 |
1990年 | 63篇 |
1989年 | 79篇 |
1988年 | 76篇 |
1987年 | 70篇 |
1986年 | 67篇 |
1985年 | 69篇 |
1984年 | 33篇 |
1983年 | 27篇 |
1982年 | 33篇 |
1981年 | 40篇 |
1980年 | 32篇 |
1979年 | 21篇 |
1978年 | 16篇 |
1977年 | 28篇 |
1976年 | 30篇 |
1975年 | 28篇 |
1973年 | 10篇 |
排序方式: 共有3404条查询结果,搜索用时 0 毫秒
1.
JM Martín† L Calduch† C Monteagudo‡ I Molina† D Ramón† V Alonso† E Jordᆠ《Journal of the European Academy of Dermatology and Venereology》2006,20(4):428-431
Cutaneous plasmacytosis is a rare disorder characterized by a benign proliferation of mature plasma cells that appears as multiple dark-brown to purplish skin lesions, often associated with polyclonal hypergammaglobulinaemia. We present the case of a 55-year-old Caucasian man who suffered from a cutaneous plasmacytosis associated with two different carcinomas. Cutaneous plasmacytosis seems to be a reactive process because most cases reported are not associated with any apparent underlying disease. Nevertheless, because few reported cases were associated with malignancies, screening of additional neoplasms would be justified. 相似文献
2.
Michael Rosenzweig Martha Skinner Tatiana Prokaeva Roger Théberge Catherine Costello Brian M Drachman Lawreen H Connors 《Amyloid》2007,14(1):65-71
We report the identification of a new transthyretin (TTR) gene mutation and variant protein, Glu61Gly, in a 55-year-old man with progressive cardiomyopathy, mild peripheral neuropathy and bilateral carpal tunnel syndrome. A diagnosis of TTR-associated familial amyloidosis (ATTR) was considered after an endomyocardial biopsy revealed amyloid deposits in the heart of a patient who had no family history of amyloidosis and no evidence of a plasma cell dyscrasia. Serum screening for a TTR variant by isoelectric focusing (IEF) was positive and prompted further studies to identify the genetic abnormality and to characterize the amyloidogenic protein. Direct DNA sequence analysis of all four coding regions in the TTR gene demonstrated heterozygosity in exon 3. Near equal amounts of guanine (G) and adenine (A) were observed at the second base position of codon 61. The wild-type (GAG) and mutated (GGG) sequences found in codon 61 correspond to glutamic acid (Glu) and glycine (Gly) residues, amino acids which differ in mass by -72 Da. Mass spectrometric analyses of TTR immunoprecipitated from serum showed the presence of both wild-type and variant proteins. The observed mass results for the wild-type and variant proteins were consistent with the predicted values calculated from the genetic analysis data. 相似文献
3.
JM Vilanova J Figueras-Aloy J Roselló G Gómez E Gelpí R Jiménez 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(5):588-592
The aim of this study was to evaluate the cerebral synthesis of eicosanoids in the asphyctic newborn and to investigate the relation between the prostanoid profiles in cerebrospinal fluid (CSF) and the appearance and severity of hypoxic-ischaemic encephalopathy (HIE). Levels of 6-keto-PGF 1-α, TXB2 , PGE2 and PGF2-α in CSF were measured in 40 full term newborns during the first day of life. Thirty of these newborns had birth asphyxia and were divided into three groups: 10 without HIE, 12 with mild HIE and 8 with moderate-severe HIE. They were compared to a control group of 10 non-hypoxic newborns. Determinations of the metabolites in CSF were performed by RIA and expressed as pg/ml (mean ± SD). The CSF TXB2 (thromboxane A2 metabolite) in asphyxiated newborns was always higher than in the control group (28.12 ± 10.6), and related to the severity of HIE ( p = 0:005): without HIE (50.84 ± 16.4; p = 0:02), mild HIE (80.65 ± 12.64; p ± 0:01) and moderate-severe HIE (178.14 ± 20.5; p < 0:01). The CSF 6-keto-PGF 1-α (prostacyclin metabolite) in asphyxiated newborns was always higher than in the control group (80.55 ± 12.56), but indirectly related to the severity of HIE: without HIE (240.95 ± 28.12; p < 0:01), mild HIE (183.65 ± 30.1; p < 0:01) and moderate-severe HIE (140.55 ± 25.12; p < 0:01). In the moderate-severe HIE group, the increase in TXB2 was higher than the rise in 6-keto-PGF 1-α . 相似文献
4.
5.
6.
7.
8.
9.
Infection with larval trematodes has been shown to inhibit several snail-host defences, including hemocyte phagocytosis, cytotoxicity, motility, and adherence. Certain plasma factors which mediate snail defence responses, and which may be produced by host hemocytes, also appear to be altered by these parasites. In this study we present protocols for the isolation of 2 proteins from larval Schistosoma mansoni excretory-secretory (ES) products and detail the effects of these components on Biomphalaria glabrata hemocyte protein synthetic/secretory (S/S) activity. Schistosome ES proteins, separated with a combination of membrane ultrafiltration, size exclusion, and ion exchange chromatography, were tested for their in vitro effect on cultured snail hemocytes, in the presence and absence of homologous plasma. A high-molecular-weight ultrafiltration fraction of parasite ES products (H30), in combination with plasma, was found to differentially affect susceptible (M-line) and resistant (10-R2) snail hemocytes. Secretion of metabolically labeled polypeptides by M-line cells was inhibited significantly while the S/S response of 10-R2 hemocyte polypeptides was not affected. In the absence of homologous plasma, little or no differential affect of ES polypeptides on hemocyte S/S activity was seen. Much of the inhibitory activity of H30 was attributable to a partially purified fraction, Peak I (PkI), of ES products. Evidence suggests that, in its native state, PkI is a high-molecular-weight protein aggregate comprising subunits of approximately 22-24 kDa. Thus, PkI, in the presence of homologous plasma components, is a potential mediator of schistosome-induced suppression of polypeptide synthesis or secretion in hemocytes of susceptible snails. In combination with other parasite and host factors, PkI may be involved in the host-parasite interaction which leads to the state of susceptibility or resistance found in our strains of B. glabrata. 相似文献
10.