全文获取类型
收费全文 | 16027篇 |
免费 | 1063篇 |
国内免费 | 129篇 |
专业分类
耳鼻咽喉 | 140篇 |
儿科学 | 470篇 |
妇产科学 | 454篇 |
基础医学 | 2480篇 |
口腔科学 | 278篇 |
临床医学 | 1324篇 |
内科学 | 3772篇 |
皮肤病学 | 380篇 |
神经病学 | 2243篇 |
特种医学 | 434篇 |
外科学 | 1453篇 |
综合类 | 31篇 |
一般理论 | 1篇 |
预防医学 | 919篇 |
眼科学 | 177篇 |
药学 | 1120篇 |
中国医学 | 32篇 |
肿瘤学 | 1511篇 |
出版年
2024年 | 29篇 |
2023年 | 204篇 |
2022年 | 438篇 |
2021年 | 735篇 |
2020年 | 400篇 |
2019年 | 495篇 |
2018年 | 648篇 |
2017年 | 470篇 |
2016年 | 540篇 |
2015年 | 604篇 |
2014年 | 741篇 |
2013年 | 975篇 |
2012年 | 1393篇 |
2011年 | 1394篇 |
2010年 | 783篇 |
2009年 | 711篇 |
2008年 | 1170篇 |
2007年 | 1060篇 |
2006年 | 961篇 |
2005年 | 854篇 |
2004年 | 781篇 |
2003年 | 690篇 |
2002年 | 528篇 |
2001年 | 56篇 |
2000年 | 40篇 |
1999年 | 59篇 |
1998年 | 105篇 |
1997年 | 65篇 |
1996年 | 46篇 |
1995年 | 40篇 |
1994年 | 44篇 |
1993年 | 21篇 |
1992年 | 19篇 |
1991年 | 17篇 |
1990年 | 16篇 |
1989年 | 14篇 |
1988年 | 6篇 |
1987年 | 10篇 |
1986年 | 10篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Expression of human CD81 in transgenic mice does not confer susceptibility to hepatitis C virus infection 总被引:6,自引:0,他引:6
Masciopinto F Freer G Burgio VL Levy S Galli-Stampino L Bendinelli M Houghton M Abrignani S Uematsu Y 《Virology》2002,304(2):187-196
We previously demonstrated that hepatitis C virus (HCV) binds to human CD81 through the E2 glycoprotein. Therefore, expression of the human CD81 molecule in transgenic mice was expected to provide a new tool to study HCV infection in vivo, as the chimpanzee is the only species currently available as a laboratory animal model that can be infected with HCV. We produced transgenic mice expressing the human CD81 protein in a wide variety of tissues. We confirmed binding of recombinant E2 glycoprotein to the liver tissue as well as to thymocytes and splenic lymphocytes in the transgenic mice. We inoculated chimpanzee plasma infected with HCV into these animals. None of these transgenic animals showed evidence of viral replication. Furthermore, human CD81 transgenic mice that lack expression of endogenous mouse CD81 were also resistant to HCV infection. We conclude that expression of human CD81 alone is insufficient to confer susceptibility to HCV infection in the mouse. The presence of additional possible factors for HCV infection is discussed. 相似文献
32.
Macchi C Popolizio A Casamorata F Bicchi S Pieroni A Molino Lova R Miniati B Gulisano M Catini C Conti AA Gensini GF 《Italian journal of anatomy and embryology = Archivio italiano di anatomia ed embriologia》2002,107(2):93-97
Fifty-four subjects, aged between 20 and 35 years, divided into two subgroups, respectively 30 healthy subjects (17 males and 13 females) and 24 subjects with "gonalgia sine materia" (13 males and 11 females) underwent isokinetic exercise test in order to compare their dominant limb with the not dominant one as regard as the strength of extensor and flexor muscles of the knee. No statistically significant difference was found in any of the studied parameters in the comparison between the dominant limb and the not dominant one, both within the subgroup of healthy subjects and within the subgroup of subjects with "gonalgia sine materia". Authors conclude that psychological features may play a preeminent role in the genesis, as well as in the maintenance of "gonalgia sine materia", thus confirming previous data available in medical literature. 相似文献
33.
Isolation of human immunodeficiency virus (HIV) from plasma during primary HIV infection 总被引:13,自引:0,他引:13
Jan Albert Hans Gaines Anders Snnerborg Gunnel Nystrm Pehr Olov Pehrson Francesca Chiodi Madeleine von Sydow Lars Moberg Knut Lidman Bertil Christensson Birgitta sj Eva Maria Feny 《Journal of medical virology》1987,23(1):67-73
Human immunodeficiency virus (HIV) has been isolated from plasma in 6 of 7 patients showing clinical symptoms of a primary HIV infection. Parallel cultures from peripheral blood mononuclear cells (PBMC) yielded virus in 5 patients. In one case, virus could only be isolated from the cerebrospinal fluid but not from peripheral blood. Detectable viremia was transient and preceded the appearance of HIV specific antibodies. After cessation of acute symptoms, the frequency of HIV isolations was similar to that of asymptomatic carriers (23 and 26%, respectively). The role of the immune response in terminating detectable viremia remains to be established. 相似文献
34.
Loriano Ballarin Francesca Cima Armando Sabbadin 《Developmental and comparative immunology》1994,18(6):467-481
Phagocytosis by Botryllus schlosseri hemocytes in influenced by temperature, pH, concentration, and physicochemical properties of the test particles and requires Ca2+ or Mg2+ ions to occur. Phagocytes recognized glucosyl or mannosyl residues on the surface of yeast cells, and a respiratory burst is associated with phagocytosis, as indicated by increased superoxide production. Factors that enhance phagocytosis of yeast, sheep red blood cells, and latex beads and reduce the uptake of yeast and sheep erythrocytes are present in the plasma. 相似文献
35.
Francesca Blasi Elena Bacchelli Giulia Pesaresi Simona Carone Anthony J Bailey Elena Maestrini 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2006,(3):220-221
Neuroligin abnormalities have been recently implicated in the aetiology of autism spectrum disorders (ASD), given the finding of point mutations in the two X-linked genes NLGN3 and NLGN4X and the important role of neuroligins in synaptogenesis. To enquire on the relevance and frequency of neuroligin mutations in ASD, we performed a mutation screening of NLGN3 and NLGN4X in a sample of 124 autism probands from the International Molecular Genetic Study of Autism Consortium (IMGSAC). We identified a new non-synonymous variant in NLGN3 (Thr632Ala), which is likely to be a rare polymorphism. Our data indicate that coding mutations in these genes are very rarely associated to ASD. 相似文献
36.
Ioachim HL Decuseara R Giancotti F Dorsett BH 《Pathology, research and practice》2005,200(11-12):743-751
FAS receptor (FAS, CD95) and FAS ligand (FAS-L, CD95-L) are complementary members of a particular apoptotic pathway that plays a major role in immune regulation. The activation of FAS-L may trigger cytotoxic mechanisms leading to the death of FAS-expressing cells. Tumor cells and tumor-infiltrating lymphocytes (TIL) may express FAS and FAS-L in various proportions, and their interplay may affect tumor behavior. In the present study, we explored the expression of FAS and FAS-L in 28 mammary carcinomas (19 ductal and 9 lobular) and in their lymph node metastases. The expression of these mediators in immunostained sections was graded and evaluated comparatively between normal and neoplastic mammary epithelium, between tumor cells and TILs, and between mammary carcinoma cells and their lymph node metastases. We demonstrated the coexpression of FAS and FAS-L by breast carcinoma cells and TIL, with FAS expressed more strongly by normal epithelial cells and TIL than tumor cells. FAS-L was better stained on tumor cells than on TIL. There was equal or greater expression of FAS and FAS-L in the primary tumors and their TIL than in the metastatic counterparts. Comparing the expression of FAS with that of FAS-L, we recorded FAS equal or stronger than FAS-L in the primary mammary tumors and the reversal of their expression, FAS-L greater than FAS in the lymph node metastases. These results are consistent with reports of studies with other tumors, suggesting that the upregulated FAS-L indicates an increased ability of tumor cells to induce apoptosis in TIL and in the normal tissues invaded. However, it is understood that the FAS/FAS-L system, although essential for apoptosis, is only a contributing factor to the complex process of tumor invasion and antitumor defense. 相似文献
37.
Francesca Grassi Aldo Giovannelli Sergio Fucile Elisabetta Mattei Fabrizio Eusebi 《Pflügers Archiv : European journal of physiology》1993,425(1-2):117-125
The cholinergic responses of the human tumour cell line TE671/RD were examined using digital Ca2+ imaging fluorescence microscopy and patch-clamp measurements. In response to stimulation of the muscarinic acetylcholine (ACh) receptor (mAChR), the intracellular concentration of Ca2+ ([Ca2+]i) rose about two-fold, in parallel with inositol 1,4,5-trisphosphate accumulation, measured by chromatographic techniques. By contrast, there was no increment of [Ca2+]i upon stimulation of the nicotinic ACh receptor (nAChR), nor after caffeine application. Electrophysiological experiments showed that TE671/RD cells lack functional voltage-activated Ca2+ channels. The stimulation of the nAChR induced transient whole-cell currents (I
ACh). Little or no current was detected in isotonic extracellular Ca2+, with Cs+ in the patch pipette. Cell pretreatment with muscarine reduced I
ACh by about 20%, without consistent modifications of current kinetics. Muscarine applied to the extra-patch membrane under the cell-attached configuration had no obvious effect on ACh-evoked unitary events. In conclusion, in human TE671/ RD cells, muscarinic stimulation increases [Ca2+]i, while nicotinic stimulation does not. In addition, the nAChR exhibits peculiar ion permeability properties and is not functionally regulated by the breakdown of phosphoinositides. 相似文献
38.
Lasalvia A Bonetto C Malchiodi F Salvi G Parabiaghi A Tansella M Ruggeri M 《Psychological medicine》2005,35(11):1655-1665
BACKGROUND: Subjective quality of life has gained a crucial role as a global measure of outcome in mental health care. This study aimed to investigate the impact of meeting needs for care, as assessed by both patients and mental health professionals, to improve the subjective quality of life in a sample of patients receiving community-based psychiatric care. METHOD: The study was conducted using a 4-year prospective longitudinal design. A cohort of patients from the South-Verona Community-based Mental Health Service (CMHS) was assessed at baseline and follow-up using, among other social and clinical measures, the Camberwell Assessment of Need (both staff and patient versions) and the Lancashire Quality of Life Profile. Predictors of changes of subjective quality of life were explored using block-stratified multiple regression procedures. RESULTS: Improvement in patients' clinical conditions as well as the reduction in patient-rated unmet needs in the social domain predicted an increase in subjective quality of life over 4 years; changes in staff-rated needs did not show any association with changes in subjective quality of life. CONCLUSIONS: Meeting self-perceived social needs, beyond symptoms reduction, seems to be of particular importance for ensuring a better quality of life for people with mental disorders. If the main goal of mental health care is to improve the quality of life of users, a policy of actively addressing patient-rated needs should be implemented. 相似文献
39.
The aim of this study was to define the effects of diltiazem, a calcium antagonist drug used in cardiology and in clinical transplantation, on the differentiation and maturation of human dendritic cells (DC). Herein, we demonstrate that diltiazem, in association with granulocyte macrophage-colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4), induces monocytes to differentiate into cells with many of the characteristic of DC. However, diltiazem-induced DC express high levels of mannose receptor and Fc gamma RII and, consequently, manifest a higher endocytic activity compared with GM-CSF+IL-4-induced DC. Importantly, diltiazem-induced DCs have an impaired responsiveness to lipopolysaccharide and CD40 ligand because they produce decreased levels of IL-12 and reveal a reduced ability to stimulate alloreactive T-cell responses as well as in inducing interferon-gamma producing Th1 cells. These effects may contribute to a decreased DC-dependent T-cell activation and may help to explain the immunoregulatory function of diltiazem and its effectiveness in preventing transplant rejection. 相似文献