全文获取类型
收费全文 | 17375篇 |
免费 | 1224篇 |
国内免费 | 610篇 |
专业分类
耳鼻咽喉 | 40篇 |
儿科学 | 392篇 |
妇产科学 | 325篇 |
基础医学 | 2230篇 |
口腔科学 | 303篇 |
临床医学 | 1825篇 |
内科学 | 2139篇 |
皮肤病学 | 189篇 |
神经病学 | 633篇 |
特种医学 | 304篇 |
外国民族医学 | 4篇 |
外科学 | 846篇 |
综合类 | 3012篇 |
现状与发展 | 1篇 |
预防医学 | 1284篇 |
眼科学 | 200篇 |
药学 | 3163篇 |
19篇 | |
中国医学 | 1312篇 |
肿瘤学 | 988篇 |
出版年
2024年 | 32篇 |
2023年 | 156篇 |
2022年 | 380篇 |
2021年 | 516篇 |
2020年 | 497篇 |
2019年 | 456篇 |
2018年 | 450篇 |
2017年 | 557篇 |
2016年 | 581篇 |
2015年 | 545篇 |
2014年 | 983篇 |
2013年 | 1158篇 |
2012年 | 900篇 |
2011年 | 1117篇 |
2010年 | 841篇 |
2009年 | 697篇 |
2008年 | 685篇 |
2007年 | 733篇 |
2006年 | 731篇 |
2005年 | 641篇 |
2004年 | 575篇 |
2003年 | 522篇 |
2002年 | 463篇 |
2001年 | 348篇 |
2000年 | 296篇 |
1999年 | 212篇 |
1998年 | 226篇 |
1997年 | 226篇 |
1996年 | 199篇 |
1995年 | 207篇 |
1994年 | 216篇 |
1993年 | 206篇 |
1992年 | 197篇 |
1991年 | 171篇 |
1990年 | 158篇 |
1989年 | 156篇 |
1988年 | 128篇 |
1987年 | 149篇 |
1986年 | 99篇 |
1985年 | 345篇 |
1984年 | 262篇 |
1983年 | 232篇 |
1982年 | 198篇 |
1981年 | 180篇 |
1980年 | 135篇 |
1979年 | 89篇 |
1978年 | 83篇 |
1977年 | 65篇 |
1976年 | 48篇 |
1975年 | 39篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
刘定海 《四川生理科学杂志》1995,(1)
本文报道免疫透射比浊法测定血清免疫球蛋白,批内CV小于2.0%,批间CV小于3.5%,表明该法简便,快速,精密度和准确度高,重复性好。 相似文献
72.
The thymus as primary site for antigen-specific T suppressor cells in neonatally induced tolerance to bovine serum albumin 总被引:1,自引:0,他引:1
The ontogeny of antigen-specific T suppressor cells in thymus and spleen was analyzed in CBA/Ca mice which were rendered tolerant as neonates by subimmunogenic doses of bovine serum albumin (low-zone tolerance). Activity of T suppressor cells from those mice was assessed by an assay in which spleen cells from animals primed with fluorescein-conjugated human gamma globulin can be stimulated in vitro to produce IgG anti-fluorescein antibodies when cultured in the presence of fluorescein-conjugated bovine serum albumin. Carrier-specific T suppressor cells appear first in the thymus (day 10), and much later (day 30) in the spleen. The data are discussed in connection with the possible role of T suppressor cells during induction of tolerance in newborn mice. 相似文献
73.
Interleukin-6 (IL-6, BSF-2 or IFN-beta 2) is thought to be the major regulator of the acute-phase protein response that follows tissue injury and inflammation, with interleukin-1 (IL-1), tumour necrosis factor and more recently, LIF or HSF III, slightly stimulatory on only certain acute phase proteins. The synthesis of the major acute-phase protein SAA, originally described as being synthesized in response to IL-1, has been claimed recently to be mainly under IL-6 regulation. Our results show that in the human hepatoma cell line HuH-7, IL-1 is the major stimulating cytokine increasing SAA synthesis by a factor in excess of 100-fold. We also show that under most conditions interleukin-6 and tumour necrosis factor stimulate additively in combination with IL-1. Isoelectric focusing has demonstrated that SAA1 and SAA2 alpha are expressed but not SAA2 beta. The HuH-7 cell line is IL-6 responsive since haptoglobin is stimulated mainly by IL-6. 相似文献
74.
75.
In vitro biosynthesis and core glycosylation of the histidine-rich protein of Plasmodium lophurae 总被引:2,自引:0,他引:2
We have characterized the early biosynthetic forms of the histidine-rich protein (HisRP), a major, granule-bound protein (Mr 58 000) of the avian malarial parasite Plasmodium lophurae. We have translated poly(A)-containing, size-selected parasite mRNA in the wheat germ cell-free system in the presence of [3H]histidine. HisRP was synthesized as a larger precursor (Mr 63 000). When dog pancreas microsomal membranes were present in the cell-free system during translation, a still larger form of HisRP (Mr 66 000) was detected. This larger form was segregated into the dog pancreas microsomal vesicles and was core glycosylated. Presumably, it corresponds to an intermediate form located in the parasite rough endoplasmic reticulum (RER). The difference in the Mr of approx. 8 000 between this RER associated 'pro' form and the granule-bound, mature form of HisRP suggests that proteolytic processing occurs upon transport from the RER to the granule. Segregation and core glycosylation were strictly coupled to translation and were not observed upon posttranslational addition of microsomal membranes. Thus, the early events in the biosynthesis of HisRP are similar to those established for secretory and lysosomal proteins. 相似文献
76.
77.
Savchenkova AP Dudnik LB Pogoretskaya IL Solov'eva NP Pokrovskaya MA Aseichev AV Drinitsyna SV Azizova OA Lopukhin YM 《Bulletin of experimental biology and medicine》2003,135(1):29-33
In patients with coronary heart disease oxidizability of lipids during Cu2+-induced oxidation of blood plasma inversely correlated with fibrinogen content. A positive correlation was found between the amount of lipid peroxidation products in the plasma from these patients and fibrinogen content. The increase in fibrinogen content was associated with high levels of total lipids and triglycerides and low concentration of high-density lipoprotein cholesterol. In vitro experiments demonstrated that fibrinogen reduces oxidizability of blood plasma. Our results suggest that the decrease in lipid oxidizability at high concentration of fibrinogen in patients with coronary heart disease is related to predominant oxidation of fibrinogen and its competition with plasma lipids during Cu2+-induced oxidation. 相似文献
78.
Detection by ELISA of IgA and IgM antibodies in secretion and IgM antibodies in serum in primary lower respiratory syncytial virus infection 总被引:3,自引:0,他引:3
Twenty-six infants and children with primary lower RS virus infection, diagnosed by the detection of RS virus in nasopharyngeal secretion (NPS) by use of immunofluorescent antibody (FA) technique, were studied with respect to the presence of IgA and IgM antibodies. Samples of NPS and serum obtained during the first 3-4 months following the beginning of illness, were investigated. Employing a reverse ELISA technique, we found IgM antibodies in the acute, but not during the convalescent, phase of illness in NPS from 20 of the patients and in serum from 21 of the patients. The majority of the IgM antibody conversions observed occurred in NPS as well as in serum on days 5-8 following the illness. RS virus IgA antibodies, also detected by a reverse ELISA technique, were demonstrated in NPS in 22 of the patients, with antibody conversions being found in 19 of the patients on days 5-8 following the beginning of the illness. Two patients still had IgA antibodies in NPS approximately 3 months FSOI. By comparison, RS virus was detected in acute-phase NPS by double-antibody sandwich ELISA in 25 of the 26 patients investigated. 相似文献
79.
David Barnes 《Methods in Cell Science》1986,10(2):69-74
Summary Methods are presented for the quantitative assay of proteins influencing cell attachment and spreading. These include assays in which cell-substratum interactions are quantitated directly and a serum-free assay in which cell growth is dependent on attachment under substratum-limited conditions. Procedures are also presented for the identification of active sites of substratum molecules through the use of antibodies and synthetic peptides that are inhibitory for cell attachment. 相似文献
80.
Maria Janusz Krystyna Starościk Wojciech Gorczyca Zbigniew Wieczorek Józef Lisowski 《Molecular immunology》1983,20(11):1149-1155
The Fc gamma receptor of guinea-pig peritoneal macrophages was purified by affinity chromatography by using rabbit IgG or guinea-pig IgG2 coupled to Sepharose. Lysates prepared by treatment of 125I-labeled macrophages with NP-40 were first applied to BSA-Sepharose and then to IgG-Sepharose and eluted with 0.5 M acetic acid containing 1% NP-40. The specific binding was determined by interaction of the 125I-labeled receptor with IgG-Sepharose in the presence and absence of soluble IgG. The specific binding of the purified receptor was 42-82%. Interactions of the purified receptor with IgG-Sepharose were equally well inhibited by soluble rabbit IgG or guinea-pig IgG2, but not by F(ab')2 fragments. Inclusion of NP-40 in the buffer used in the assay reduced nonspecific binding of the receptor to the affinity gels. The purified receptor can be stored for 20 days at 4 degrees C without a significant loss of the specific binding activity. Analysis of the receptor by SDS-polyacrylamide gel electrophoresis, under nonreducing and reducing conditions, revealed two major peaks of radioactivity corresponding to mol. wts of about 50,000 and 25,000, and one very minor peak corresponding to a mol. wt of about 30,000. The results obtained suggest that the protein of the second major peak is a product of the dissociation of the protein of the first major peak rather than a product of its reduction by 2-mercaptoethanol. 相似文献