全文获取类型
收费全文 | 10403篇 |
免费 | 942篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 98篇 |
儿科学 | 255篇 |
妇产科学 | 371篇 |
基础医学 | 1593篇 |
口腔科学 | 121篇 |
临床医学 | 820篇 |
内科学 | 2063篇 |
皮肤病学 | 497篇 |
神经病学 | 1040篇 |
特种医学 | 381篇 |
外科学 | 1347篇 |
综合类 | 75篇 |
一般理论 | 2篇 |
预防医学 | 1062篇 |
眼科学 | 99篇 |
药学 | 861篇 |
中国医学 | 37篇 |
肿瘤学 | 664篇 |
出版年
2023年 | 83篇 |
2022年 | 92篇 |
2021年 | 163篇 |
2020年 | 139篇 |
2019年 | 191篇 |
2018年 | 202篇 |
2017年 | 188篇 |
2016年 | 194篇 |
2015年 | 221篇 |
2014年 | 236篇 |
2013年 | 445篇 |
2012年 | 527篇 |
2011年 | 506篇 |
2010年 | 317篇 |
2009年 | 312篇 |
2008年 | 472篇 |
2007年 | 428篇 |
2006年 | 474篇 |
2005年 | 437篇 |
2004年 | 438篇 |
2003年 | 381篇 |
2002年 | 336篇 |
2001年 | 315篇 |
2000年 | 334篇 |
1999年 | 299篇 |
1998年 | 141篇 |
1997年 | 105篇 |
1996年 | 112篇 |
1995年 | 113篇 |
1994年 | 104篇 |
1993年 | 90篇 |
1992年 | 212篇 |
1991年 | 221篇 |
1990年 | 200篇 |
1989年 | 226篇 |
1988年 | 208篇 |
1987年 | 192篇 |
1986年 | 165篇 |
1985年 | 176篇 |
1984年 | 143篇 |
1983年 | 109篇 |
1982年 | 93篇 |
1981年 | 70篇 |
1979年 | 102篇 |
1978年 | 78篇 |
1977年 | 81篇 |
1976年 | 64篇 |
1975年 | 63篇 |
1974年 | 65篇 |
1973年 | 68篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Upregulation of TGF-beta, FOXP3, and CD4+CD25+ regulatory T cells correlates with more rapid parasite growth in human malaria infection 总被引:8,自引:0,他引:8
Walther M Tongren JE Andrews L Korbel D King E Fletcher H Andersen RF Bejon P Thompson F Dunachie SJ Edele F de Souza JB Sinden RE Gilbert SC Riley EM Hill AV 《Immunity》2005,23(3):287-296
Understanding the regulation of immune responses is central for control of autoimmune and infectious disease. In murine models of autoimmunity and chronic inflammatory disease, potent regulatory T lymphocytes have recently been characterized. Despite an explosion of interest in these cells, their relevance to human disease has been uncertain. In a longitudinal study of malaria sporozoite infection via the natural route, we provide evidence that regulatory T cells have modifying effects on blood-stage infection in vivo in humans. Cells with the characteristics of regulatory T cells are rapidly induced following blood-stage infection and are associated with a burst of TGF-beta production, decreased proinflammatory cytokine production, and decreased antigen-specific immune responses. Both the production of TGF-beta and the presence of CD4+CD25+FOXP3+ regulatory T cells are associated with higher rates of parasite growth in vivo. P. falciparum-mediated induction of regulatory T cells may represent a parasite-specific virulence factor. 相似文献
72.
73.
Knudsen TB Kledal TN Andersen O Eugen-Olsen J Kristiansen TB 《Scandinavian journal of immunology》2003,58(3):277-284
The recent identification of a novel clinical entity, the severe acute respiratory syndrome (SARS), the rapid subsequent spread and case fatality rates of 14-15% have prompted a massive international collaborative investigation facilitated by a network of laboratories established by the World Health Organization (WHO). As SARS has the potential of becoming the first pandemic of the new millennium, a global warning by the WHO was issued on 12 March 2003. The disease, which is believed to have its origin in the Chinese Guangdong province, spread from Hong Kong via international airports to its current worldwide distribution. The concerted efforts of a globally united scientific community have led to the independent isolation and identification of a novel coronavirus from SARS patients by several groups. The extraordinarily rapid isolation of a causative agent of this newly emerged infectious disease constitutes an unprecedented scientific achievement. The main scope of the article is to provide the clinician with an overview of the natural history, epidemiology and clinical characteristics of SARS. On the basis of the recently published viral genome and structural features common to the members of the coronavirus family, a model for host cell-virus interaction and possible targets for antiviral drugs are presented. The epidemiological consequences of introducing a novel pathogen in a previously unexposed population and the origin and evolution of a new and more pathogenic strain of coronavirus are discussed. 相似文献
74.
B B Rasmussen C Rose S M Thorpe K W Andersen K Hou-Jensen 《American journal of clinical pathology》1985,84(6):737-740
Two hundred two human, mucinous breast carcinomas were investigated for the presence of argyrophilic granules, and these granules were found in 25% of the cases. The granules were located in the cytoplasm and were heterogeneously distributed within the tumors. Tumors with granules were otherwise morphologically indistinguishable from those tumors without granules. The recurrence-free survival was independent of the presence of granules, and no relation was found to other clinical or histopathologic factors. Tumors with granules were found to be estrogen-receptor positive, and they appear to have a slightly less aggressive growth pattern than tumors without granules, but the difference is far from being statistically significant. It is concluded that there is no convincing evidence that this group of primary breast carcinomas with argyrophilia originates from APUD cells. 相似文献
75.
The number of plaque-forming cells (PFC) developed in pokeweed mitogen (PWM)-activated unfractionated or T/B separated, 4:1 reconstituted cultures of peripheral blood lymphocytes (PBL) with well-characterized subpopulations obtained from healthy, aged subjects was compared to that of young blood donors. The absolute number of PBL in the aged was reduced by 36%, and the percentage of sheep erythrocyte-rosette-forming cells (E-RFC) by 27%, compared to the percentage obtained in young donors. The IgM-, IgG- and IgA-immunoglobulin (Ig) secretion was monitored with a protein A PFC assay. The number of PFC in PBL cultures of the aged was 58% of the number found in cultures of the young controls. The number of PFC generated in cultures of autologous irradiated T and untreated B cells showed a 104% increase in the aged whereas a 63% increase was obtained using cells from young individuals. Co-cultures of young B cells with untreated or irradiated young or aged T cells showed a significant rise in the PFC response in cultures with irradiated aged T cells, while an equal number of PFC was generated in cultures of young B cells with young or aged untreated T cells. Our results demonstrate a decreased number of PBL, especially T cells, an impaired B cell function and a pronounced enhancement of the PFC response in cultures of irradiated aged T cells and young or aged B cells, whereas the T helper function of untreated cells was found to be normal. The influence of monocytes on the PFC response did not differ in the two groups. 相似文献
76.
R G Robinson M Tortosa J Sullivan E Buchanan A E Andersen M F Folstein 《Psychosomatic medicine》1983,45(4):283-292
Hospitalized patients with anorexia nervosa (N = 17) or bulimia (N = 11) were given a standard liquid meal containing 400 calories. Using analogue scales, bulimic patients were found to have greater anxiety, lower mood, lower sexual arousal, and more fear of fatness than either control or anorectic patients. This finding of increased general "dysphoria" in bulimic patients persisted after the meal without any significant premeal to postmeal changes. Anorectic patients also differed from controls, but less than the bulimic patients. Some measures of anxiety correlated significantly with body mass index before the meal in bulimic patients, whereas in anorectic patients the correlation was significant only after the meal. 相似文献
77.
78.
Pinborg A Loft A Rasmussen S Schmidt L Langhoff-Roos J Greisen G Andersen AN 《Human reproduction (Oxford, England)》2004,19(2):435-441
BACKGROUND: In Denmark, one-third of twin pregnancies are the result of IVF/ICSI treatment. Limited data on neonatal outcome in IVF/ICSI twins are available in the literature. METHODS: A register study was conducted on neonatal morbidity and mortality in a complete national twin cohort including all 3438 (3393 live-born) IVF/ICSI and 10,362 (10,239 live-born) non-IVF/ICSI twins born between 1995 and 2000. Twins were identified in the National Medical Birth Registry and dichotomized into IVF/ICSI and non-IVF/ICSI by cross-reference with the Danish IVF Registry. Data on neonatal morbidity and mortality were retrieved from the Danish Patient Registry and the Danish Registry of Causes of Deaths. In order to exclude monozygotic twins, sub-analyses on unlike-sex twins were conducted. RESULTS: A birth weight discordance of >20% was observed in 20.6% of IVF/ICSI versus 15.7% of control twin pairs (P < 0.001). The risk of discordant birth weight >20% was OR 1.29 (95% CI 1.04-1.58) in unlike-sex IVF/ICSI twins versus control twins. The risk of delivery at <37 completed weeks and birth weight <2500 g was similar in the two cohorts; however, in unlike-sex IVF/ICSI versus control twins the risk of delivery at <37 weeks and birth weight <2500 g was OR 1.22 (95% CI 1.09-1.38) and OR 1.25 (1.11-1.40) respectively. After stratification for maternal age and parity, these risks disappeared. IVF/ICSI twins carried a higher risk of admittance to a neonatal intensive care unit (NICU) than control twins (OR 1.18, 95% CI 1.09-1.27), and this was even more pronounced in unlike-sex twins [OR 1.34 (95% CI 1.19-1.51)]. No differences were observed in malformation or mortality rates between the two cohorts. CONCLUSIONS: Despite higher birth weight discordance and more NICU admissions among IVF/ICSI twins, neonatal outcome in IVF/ICSI twins seems to be comparable with that of non-IVF/ICSI twins, when only dizygotic twins were considered in the comparisons. 相似文献
79.
Doctors'' characteristics do not predict long-term glycaemic control in type 2 diabetic patients. 下载免费PDF全文
Lars J Hansen Niels de Fine Olivarius Volkert Siersma John Sahl Andersen 《The British journal of general practice》2003,53(486):47-49
Glycaemic control in type 2 diabetic patients varies widely between general practitioners (GPs). To increase our understanding of this variation, linear random effects models were used to examine the predictive value of GP characteristics on the course of annual HbA1c measurements, in 688 newly diagnosed type 2 diabetic patients between one and five years after diabetes diagnosis. We found that characteristics of centrally supported GPs, such as interest in diabetes, experience, practice type, list size, and weekly working hours, did not predict their patients' glycaemic control. 相似文献
80.
Capillary array electrophoresis (CAE) is a novel technique, which allows for high throughput analysis of DNA fragments. When screening for mutations in whole populations or large patient groups it is necessary to have robust and well-characterized setups for high throughput analysis. For large-scale mutation screening, we have developed procedures for single strand conformation polymorphism (SSCP) assays using CAE (CAE-SSCP) whereby we may increase both the sensitivity and the throughput compared to conventional SSCP analysis. In this study we have validated CAE-SSCP by 1) comparing detection by slab-gel based SSCP with CAE-SSCP of mutations in the MYH7, MYL2, and MYL3 genes encoding sarcomere proteins from patients suffering from hypertrophic cardiomyopathy; and 2) by constructing a series of 185 mutants having substitution mutations, as well as insertion/deletion mutations, or some combinations of these, in different sequence contexts in four exons and different positions relative to the end of the amplicon (three from the KCNQ1 gene, encoding a cardiac potassium channel, and one from the TNNI3 gene encoding cardiac troponin I). The method identified 181 out of 185 mutations (98%), and the data suggest that the position of mutation in the fragment had no effect on the sensitivity. Analysis of the specificity of the method showed that only very few mutants could not be distinguished from each other and there were no false positives. 相似文献