全文获取类型
收费全文 | 16598篇 |
免费 | 1129篇 |
国内免费 | 72篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 351篇 |
妇产科学 | 537篇 |
基础医学 | 2774篇 |
口腔科学 | 189篇 |
临床医学 | 1610篇 |
内科学 | 3967篇 |
皮肤病学 | 141篇 |
神经病学 | 1455篇 |
特种医学 | 558篇 |
外国民族医学 | 1篇 |
外科学 | 2689篇 |
综合类 | 143篇 |
一般理论 | 7篇 |
预防医学 | 961篇 |
眼科学 | 137篇 |
药学 | 1007篇 |
中国医学 | 21篇 |
肿瘤学 | 1174篇 |
出版年
2023年 | 50篇 |
2022年 | 94篇 |
2021年 | 224篇 |
2020年 | 133篇 |
2019年 | 255篇 |
2018年 | 328篇 |
2017年 | 206篇 |
2016年 | 264篇 |
2015年 | 357篇 |
2014年 | 475篇 |
2013年 | 696篇 |
2012年 | 999篇 |
2011年 | 1132篇 |
2010年 | 715篇 |
2009年 | 694篇 |
2008年 | 1139篇 |
2007年 | 1136篇 |
2006年 | 1132篇 |
2005年 | 1201篇 |
2004年 | 1086篇 |
2003年 | 1064篇 |
2002年 | 1078篇 |
2001年 | 191篇 |
2000年 | 166篇 |
1999年 | 203篇 |
1998年 | 262篇 |
1997年 | 240篇 |
1996年 | 191篇 |
1995年 | 193篇 |
1994年 | 170篇 |
1993年 | 168篇 |
1992年 | 153篇 |
1991年 | 115篇 |
1990年 | 100篇 |
1989年 | 89篇 |
1988年 | 83篇 |
1987年 | 77篇 |
1986年 | 76篇 |
1985年 | 53篇 |
1984年 | 73篇 |
1983年 | 61篇 |
1982年 | 71篇 |
1981年 | 89篇 |
1980年 | 44篇 |
1979年 | 42篇 |
1978年 | 41篇 |
1977年 | 29篇 |
1976年 | 28篇 |
1975年 | 31篇 |
1973年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Secretion of a chemotactic factor for neutrophils and eosinophils by alveolar macrophages from asthmatic patients 总被引:10,自引:0,他引:10
Philippe Gosset Ph.C. AndrBernard Tonnel M.D. Michel Joseph Ph.D. Lionel Prin M.D. Anne Mallart M.D. Jacques Charon D.D.S. Andr Capron M.D. 《The Journal of allergy and clinical immunology》1984,74(6):827-834
The studies presented in this article demonstrate the release of an IgE-dependent chemotactic factor for polymorphonuclear neutrophils (PMN) and eosinophils by alveolar macrophages (AMs) from normal subjects (n = 15) and allergic asthmatic patients (n = 15). A 60-minute incubation of normal AMs previously sensitized by 20% nonheated allergic sera with anti-human IgE antibody or the related allergen induced the release of a chemotactic activity (CA) for PMN and eosinophils in culture supernatants. When AMs were obtained from asthmatic patients, direct incubation with anti-IgE or the related allergen induced the same CA, whereas incubation with an unrelated allergen failed to produce CA (neutrophil CA after addition of anti-IgE, 22.5 +/- 3.5 cells per high power field; with related allergen, 15.8 +/- 3.6; with unrelated allergen, 0.7 +/- 1.8; p less than 0.0001). A partial characterization of the neutrophil chemotactic factor was carried out. Enzymatic treatment by trypsin or carboxypeptidase or by heating (56 degrees C for 3 hr) failed to abolish the neutrophil CA. After gel filtration the greater part of the neutrophil CA (80%) was recovered among low-molecular-weight components (300 to 1300 daltons). A preliminary deactivation of PMN by leukotriene B4 suppressed the CA of AM supernatants. These results indicate that IgE-dependent stimulation of AMs produces a neutrophil and eosinophil CA, present in a low-molecular-weight fraction possibly related to leukotrienes, and emphasizes the role of AMs in inflammatory lung processes during allergic asthma. 相似文献
72.
Myrna Medlej-Hashim Valérie Delague Eliane Chouery Nabiha Salem Mohammed Rawashdeh Gérard Lefranc Jacques Loiselet André Mégarbané 《BMC medical genetics》2004,5(1):1-6
Background
Hemihyperplasia (hemihypertrophy) is defined as asymmetric body overgrowth of one or more body parts. Hemihyperplasia can be isolated or be part of well-defined syndromes such as in the case of Beckwith-Wiedemann syndrome (BWS). Isolated hemihyperplasia is usually sporadic, but a number of familial occurrences have been described.Case presentation
We describe a Tunisian family in which three maternal cousins and their maternal grandfather present with isolated hemihyperplasia.Conclusions
The etiology of isolated hemihyperplasia is unknown although in BWS, genomic imprinting has been shown to play a role in the asymmetric overgrowth. Given the similarity between these two conditions, it is possible that both may share a common pathogenesis. We also discuss the possible genetic mechanisms leading to the production of hemihyperplasia in this family. 相似文献73.
Katrien Vekemans Qiang Liu Jacques Pirenne Diethard Monbaliu 《Anatomical record (Hoboken, N.J. : 2007)》2008,291(6):735-740
Due to the sharp increase in liver transplant candidates and the subsequent shortage of suitable donor livers, an extension of the current donor criteria is necessary. Simple cold storage, the current standard in organ preservation has proven to be insufficient to preserve extended criteria donor livers. Therefore a renewed interest grew toward alternative methods for liver preservation, such as hypothermic machine perfusion and normothermic machine perfusion. These “new” preservation methods were primarily assessed in rat models, and only a few clinically relevant large animal models have been described so far. This review will elaborate on these alternative preservation methods. Anat Rec, 291:735–740, 2008. © 2008 Wiley‐Liss, Inc. 相似文献
74.
Rapid detection of methicillin-resistant Staphylococcus aureus directly from sterile or nonsterile clinical samples by a new molecular assay 总被引:13,自引:0,他引:13
Francois P Pittet D Bento M Pepey B Vaudaux P Lew D Schrenzel J 《Journal of clinical microbiology》2003,41(1):254-260
A rapid procedure was developed for detection and identification of methicillin-resistant Staphylococcus aureus (MRSA) directly from sterile sites or mixed flora samples (e.g., nose or inguinal swabs). After a rapid conditioning of samples, the method consists of two main steps: (i) immunomagnetic enrichment in S. aureus and (ii) amplification-detection profile on DNA extracts using multiplex quantitative PCR (5'-exonuclease qPCR, TaqMan). The triplex qPCR assay measures simultaneously the following targets: (i) mecA gene, conferring methicillin resistance, common to both S. aureus and Staphylococcus epidermidis; (ii) femA gene from S. aureus; and (iii) femA gene from S. epidermidis. This quantitative approach allows discrimination of the origin of the measured mecA signal. qPCR data were calibrated using two reference strains (MRSA and methicillin-resistant S. epidermidis) processed in parallel to clinical samples. This 96-well format assay allowed analysis of 30 swab samples per run and detection of the presence of MRSA with exquisite sensitivity compared to optimal culture-based techniques. The complete protocol may provide results in less than 6 h (while standard procedure needs 2 to 3 days), thus allowing prompt and cost-effective implementation of contact precautions. 相似文献
75.
Dominique Blanchard Claude Gaillard Patrice Hermann Jacques Banchereau 《European journal of immunology》1994,24(2):330-335
In the present study, we examined the participation of CD40 ligand (L)-CD40 interaction in T cell-dependent B cell responses. To this end, purified B lymphocytes were cultured over irradiated CD4+ cloned T cells activated with immobilized anti-CD3 antibody. The anti-CD40 mAb 89 strongly blocked, in a specific fashion, both proliferation and Ig secretion of tonsil B cells. Interestingly, proliferation of surface (s)IgD+ B cell was significantly less inhibited by anti-CD40 than that of sIgD? cells. Preactivated T cells induced B cells to grow and secrete immunoglobulins preferentially in response to IL-2. This contrasts with the CD40 system where B cells are essentially responsive to IL-4 and IL-10 but not to IL-2 alone. Collectively, these data indicate that CD40L-CD40 interaction plays an important role in IL-2-mediated T cell-dependent B cell responses. However, the activation of a subset of sIgD+ cells may be independent of this interaction. 相似文献
76.
Nassim Kamar Karine Sandres-Saune David Ribes Michel Duffaut Jannick Selves Dominique Durand Jacques Izopet Lionel Rostaing 《Journal of clinical virology》2004,31(4):298-303
BACKGROUND: Following renal transplantation (RT), chronic immunosuppression is associated in hepatitis B virus (HBV) (+) patients with a flare-up of the disease, which might be harmful in the long term. OBJECTIVES: We report on the effect of long-term lamivudine therapy given at an initial daily dose of 100mg in 18 HBV (+) RT patients. RESULTS: When lamivudine therapy was commenced, 14 patients (77%) had an increase in their aspartate (AST) and alanine (ALT) aminotransferase levels. During a mean follow-up, under treatment, of 36.5 +/- 3.5 months (up to 66 months), 10 patients (55%) had a sustained partial (HBV DNA < 4 x 10(5)copies/ml) (n = 4) or complete (HBV DNA < 400 copies/ml) (n = 6) virological response. Overall, 12 virological breakthroughs were observed. Of those who were HBe Ag(+) prior to lamivudine therapy (n = 4), one seroconverted to HBe Ab during therapy. At the last follow-up, AST and ALT levels were normal in 13 patients. When liver biopsy was repeated during treatment (n = 15), the virological responders showed a significant decrease in total Knodell score from 10 +/- 0.6 to 7 +/- 1 (P = 0.04), but no significant change in the stage of fibrosis. Conversely, in those patients with high HBV DNA titers, there were no significant changes in the total Knodell score or in the grade of fibrosis. CONCLUSION: In conclusion, lamivudine therapy is safe in HBV(+)ve renal-transplant patients. However, even if the full and partial virological response rates are still high (55%) in the long term, relapse or primary non-responses occur. The implementation of alternative efficient strategies is warranted. 相似文献
77.
Jacques R. Caldwell David E. Pearce Craig Spencer Rosmarie Leder Robert H. Waldman 《The Journal of allergy and clinical immunology》1973,52(4):225-230
Immunologic studies were performed on 5 patients with pigeon breeders' disease. Intradermal injection of pigeon serum produced an immediate wheal-and-flare reaction within 15 minutes and a secondary Arthus-type reaction within 4 to 8 hours. Immunofluorescent studies of the secondary reaction site showed IgG, C3, and C4 in 2 patients. Patients' sera produced multiple precipitin bands with pigeon serum when reacted by double diffusion in gel. IgG antibody isolated from each of the patients' serum formed precipitating immune complexes that fixed large amounts of complement (C4) when added to fresh human serum. Peripheral blood lymphocytes from 4 of the 5 patients produced macrophage migration inhibitory factor (MIF) when challenged with dilute pigeon serum. These studies are the first to show complement fixing antibodies and macrophage MIF production by lymphocytes from patients with hypersensitivity lung disease and suggest that both humoral and cellular immunity may be important in the pathogenesis of these disorders. 相似文献
78.
Patrice Hermann Dominique Blanchard Blandine de Saint-Vis Franois Fossiez Claude Gaillard BAtrice Vanbervliet Francine Brire Jacques Banchereau Jean-Pierre Galizzi 《European journal of immunology》1993,23(4):961-964
To identify the ligand(s) of the human CD40 antigen, a cDNA encoding the extracellular domain of the CD40 antigen was fused to a cDNA encoding the constant region (Fc) of human IgGl. The CD40-Fc fusion protein was able to specifically bind to CD4+ and various CD8+ T cell clones activated with immobilized anti-CD3. The 125I-labeled CD40-Fc fusion protein bound anti-CD3 activated CD4+ T cell clone (MT9) with an equilibrium dissociation constant (Ka) of 10-20 nM. The human CD40-binding protein expressed on the cell surface of activated T lymphocytes is a monomeric protein of ≈ 32 kDa. Minor components of 29 kDa and 17 kDa were also detected. A small proportion of CD4+ and CD8+ blood mononuclear T cells activated by anti-CD3 expressed the CD40 ligand but its detection was best observed following depletion of B cells. Addition of B cells to purified T cells abolished the binding of CD40-Fc obtained after anti-CD3 activation. 相似文献
79.
David Cohen Jacques Michel Mina Ferne Sonya Bergner-Rabinowitz Isaac Ginsburg 《Inflammation》1979,3(4):395-403
Leukocyte extracts, trypsin, and lysozyme are all capable of releasing the bulk of the LPS from S. typhi, S. typhimurium, and E. coli. Bacteria which have been killed by heat, ultraviolet irradiation, or by a variety of metabolic inhibitors and antibiotics which affect protein, DNA, RNA, and cell wall synthesis no longer yield soluble LPS following treatment with the releasing agents. On the other hand, bacteria which are resistant to certain of the antibiotics yield nearly the full amount of soluble LPS following treatment, suggesting that certain heatlabile endogenous metabolic pathways collaborate with the releasing agents in the release of LPS from the bacteria. It is suggested that some of the beneficial effects of antibiotics on infections with gram-negative bacteria may be the prevention of massive release of endotoxin by leukocyte enzymes in inflammatory sites. 相似文献
80.
Paulette Mezin Jean-Paul Brion Jacques Vermont Max Micoud Pierre Stoebner 《Ultrastructural pathology》1991,15(6):593-602
Light and electron microscopic studies were performed on neuromuscular biopsy specimens from 12 neurologically affected seropositive patients, 7 with the acquired immune deficiency syndrome (AIDS), 2 with AIDS-related complex, and 3 with no symptoms except for neuropathy. All patients had an axonal injury associated or unassociated with demyelination and peripheral neurogenic atrophy. Capillary lesions were consistently present, which seems to be a new finding. Moreover, tubuloreticular inclusions (TRIs) were found in endomysial (9 of 12 cases) and endoneurial (7 of 12 cases) vessels. Statistical analysis showed that TRIs in more than 20% of endomysial vessels correlated with a survival time shorter than 12 months (P = 0.028). Thus the quantification of TRIs seems to be one of the vital prognostic elements in this patient population. 相似文献