全文获取类型
收费全文 | 8646篇 |
免费 | 388篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 64篇 |
儿科学 | 180篇 |
妇产科学 | 156篇 |
基础医学 | 1055篇 |
口腔科学 | 210篇 |
临床医学 | 594篇 |
内科学 | 2194篇 |
皮肤病学 | 223篇 |
神经病学 | 1107篇 |
特种医学 | 237篇 |
外科学 | 1184篇 |
综合类 | 35篇 |
预防医学 | 263篇 |
眼科学 | 266篇 |
药学 | 559篇 |
中国医学 | 43篇 |
肿瘤学 | 705篇 |
出版年
2023年 | 47篇 |
2022年 | 87篇 |
2021年 | 163篇 |
2020年 | 114篇 |
2019年 | 140篇 |
2018年 | 179篇 |
2017年 | 128篇 |
2016年 | 136篇 |
2015年 | 141篇 |
2014年 | 228篇 |
2013年 | 258篇 |
2012年 | 428篇 |
2011年 | 465篇 |
2010年 | 248篇 |
2009年 | 220篇 |
2008年 | 403篇 |
2007年 | 460篇 |
2006年 | 409篇 |
2005年 | 457篇 |
2004年 | 387篇 |
2003年 | 377篇 |
2002年 | 345篇 |
2001年 | 229篇 |
2000年 | 243篇 |
1999年 | 205篇 |
1998年 | 100篇 |
1997年 | 84篇 |
1996年 | 56篇 |
1995年 | 63篇 |
1994年 | 58篇 |
1993年 | 54篇 |
1992年 | 172篇 |
1991年 | 169篇 |
1990年 | 157篇 |
1989年 | 169篇 |
1988年 | 153篇 |
1987年 | 120篇 |
1986年 | 113篇 |
1985年 | 133篇 |
1984年 | 102篇 |
1983年 | 83篇 |
1979年 | 75篇 |
1978年 | 45篇 |
1977年 | 46篇 |
1976年 | 49篇 |
1974年 | 51篇 |
1973年 | 57篇 |
1972年 | 50篇 |
1970年 | 53篇 |
1969年 | 53篇 |
排序方式: 共有9075条查询结果,搜索用时 15 毫秒
41.
The lenses of ICR/f-strain rats with hereditary cataract were monitored in situ by laser Raman spectroscopy. The lenses used were within the age of 3-10 weeks before lens opacification became manifest. The reduction of protein SH group content and the increase of protein S-S bond content were observed in ICR/f rats in the precataractous stage. No significant change in the water content was observed. 相似文献
42.
Shimeru Kamihira Shigehiro Nakashima Shin Saitoh Michiko Kawamoto Yumiko Kawashima Mitoshi Shimamoto 《Cancer science》1993,84(8):834-837
A fully automated chemiluminescence immunoassay was developed for the detection of antibodies to HTLV-I. We used partially purified viral antigens coated on small polystyrene beads together with acridinium ester-labeled anti-human immunoglobulin G mouse immunoglobulin G in this method. A good agreement was observed between our proposed method, the indirect immunofluorescence assay, the particle-agglutination test and the enzyme immunoassay. This new method, which is simple, sensitive, specific and rapid, should be useful for mass screening of anti-HTLV-I antibodies. 相似文献
43.
A 47-year-old woman visited a clinic with dyspnea which had continued for two months and was followed by general fatigue and fever. Antibiotics were not effective. Edematous erythema occurred on her face, elbows, knees and feet, and she entered our hospital. A skin biopsy revealed interface dermatitis with severe edema and mucinosis in dermis. Diffuse bilateral infiltration was observed in the chest X-ray, and laboratory findings showed increased LDH, GPT, GOT and CPK. No antinuclear factor was detected. Her respiratory condition rapidly worsened, and she died eight days after hospitalization in spite of corticosteroid pulse therapy. The autopsy revealed that the main cause of death was diffuse alveolar damage (DAD). Interstitial pneumonia related to dermatomyositis is not histologically uniform; the response to the therapy depends on its histological type. The patients with dermatomyositis who have poor prognosis are clinically characterized by acute onset with general symptoms and less pronounced muscle weakness; they generally show DAD in their lungs. We need to establish a simple method for distinguishing histological types of interstitial pneumonia and adequate therapy for each one. 相似文献
44.
Yun-Qing Li Masahiko Takada Yasuhide Shinonaga Noboru Mizuno 《The Journal of comparative neurology》1993,333(1):118-133
The lateral habenular nucleus of the rat contains a dense plexus of dopaminergic fibers, which are more marked in the medial part of the lateral habenular nucleus than in its lateral counterpart. Employing a combination of fluorescent retrograde axonal tracing with fluorogold and tyrosine hydroxylase immunofluorescence histochemistry, we investigated the distribution of cells of origin of the dopaminergic afferent fibers to the lateral habenular nucleus in the rat. The cells double-labeled with both fluorogold injected into the lateral habenular nucleus and tyrosine hydroxylase antisera were seen in a variety of fore- and midbrain regions, including the bed nucleus of the stria terminalis, medial preoptic area, periventricular, ventromedial, and dorsomedial hypothalamic nuclei, ventral tegmental area, interfascicular nucleus, substantia nigra pars compacta, ventrolateral division of the midbrain periaqueductal gray, and dorsal raphe nucleus. The double-labeled cells were located bilaterally with an ipsilateral predominance, and constituted approximately 10% of the total fluorogold-positive cell population. We have further observed by anterograde axonal tracing with Phaseolus vulgaris–leucoagglutinin that projection fibers arising from the sites of origin of the dopaminergic afferent fibers to the lateral habenular nucleus terminate mainly in the medial part of the lateral habenular nucleus, and to a lesser extent in its lateral conterpart. Thus, we have found in the present study that the dopaminergic neurons sending their axons to the lateral habenular nucleus are widely distributed in the A9, A10, A14, and A15 dopaminergic cell groups. Such dopaminergic neurons may exert regulatory influences upon many limbic-associated brain regions via the lateral habenular nucleus. © 1993 Wiley-Liss, Inc. 相似文献
45.
Health risk appraisal (HRA) is a new health educational tool widely-used in the United States, which informs clients about how their health habits and lifestyles affect their probability of dying from potentially preventable causes and helps to motivate them to reduce their personal health risks. It personalizes mortality statistics and epidemiologic data by combining these data with a person's risk factors. We have got started the development of HRA for Japanese with reference to a new version of HRA named "Healthier People" revised by the Carter Center of Emory University and the Centers for Disease Control in the United States. 相似文献
46.
Nishioka K Okano M Ichihara Y Ichihara N Nishizaki K 《International archives of allergy and immunology》2005,136(2):142-147
BACKGROUND: Exposure to acute stressors modulates both innate and acquired immune function. However, little is known about whether stress has the potential to modulate the pathogenesis of allergic rhinitis. OBJECTIVES: To determine the effects of acute restraint stress on the initiation of allergic rhinitis in a murine model. METHODS: CBA/J mice were repeatedly intranasally sensitized with phospholipase A2 (PLA2) from honeybee venom without adjuvant. Restraint stress was applied using uniform cylinders once a week for a continuous 8-hour period, on five occasions in total. Production of PLA2-specific antibodies and degree of nasal and blood eosinophilia were compared between stressed and control mice. RESULTS: Repeated intranasal sensitization with PLA2 induced PLA2-specific IgE and marked eosinophilia in both the nose and blood in CBA/J mice. Exposure to restraint stress significantly inhibited production of PLA2-specific IgE, IgG1 and IgG2a. Conversely, the stress exerted no significant effect on eosinophilia. CONCLUSIONS: Exposure to acute restraint stress inhibits antigen-specific antibody production, but not local or systemic eosinophilia. The results of this study suggest that acute stress has the potential to modulate the initiation of allergic rhinitis. 相似文献
47.
Mutational screening of APP gene in patients with early-onset Alzheimer disease utilizing mismatched PCR-RFLP 总被引:1,自引:0,他引:1
Yumiko Nishiwaki Kouzin Kamino Aoi Yoshiiwa Keiko Nagano Masatoshi Takeda Hirotaka Tanabe Tsuyoshi Nishimura Toshiko Kobayashi Hideki Yamamoto Yasuhiro Nonomura Hiroshi Yoneda Toshiaki Sakai Masaki Imagawa Tetsuro Miki Toshio Ogihara 《Clinical genetics》1996,49(3):119-123
To elucidate the frequency of mutations of the β/A4 amyloid protein precursor (APP) gene in early-onset Alzheimer disease, we designed a mismatched PCR-RFLP that can identify all kinds of missense mutations at codon 717 in addition to the seven kinds of known mutations at exon 17. When we screened mutations at exon 17 utilizing this method and the double missense mutations at exon 16 of the APP gene by PCR-RFLP, no cases revealed mutations of the APP gene among 13 familial and 54 sporadic cases, except one family (OS-1) that had previously been reported and used as a positive control of APP717(Val → Ile). Our results support the hypothesis that mutations in the APP gene are not major causes in early-onset Alzheimer disease. 相似文献
48.
49.
Different immunosuppresive effects of anti-red blood cell sera and their fractions obtained from various animal species
下载免费PDF全文
![点击此处可从《Immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Sheep red cells (RC) were coupled with HSA by means of an HSA—anti-SRBC IgG conjugate. The coupled RC were used to prepare rosettes with spleen cells of mice immunized to HSA in Freund's complete adjuvant. The rosettes were fractionated on discontinuous Ficoll gradients and the rosette-rich and rosette-poor fractions were tested for ability to transfer adoptively secondary responsiveness to HSA. Efficiency of transfer was measured in terms of haemagglutination titres. Memory of HSA was shown to be associated with rosette-forming cells, i.e. with cells carrying receptors for HSA. Several parameters of the adoptive transfer system employed were studied. The HSA-coupled RC proved to be very efficient in stimulating secondary responses to HSA. High titres of haemagglutinating antibodies (up to 1/80,000) were obtained with 10 × 106 spleen cells transferred and 2 × 106 spleen cells consistently gave titres of the order of 1/10,000. 相似文献
50.
We investigated the effects of suppression of complement activation at C3 level and inhibition of C5a on acute synovitis in rats. Acute synovitis was induced in Wistar rats by intra-articular (i.a.) injection into one knee of 0.3 mg of MoAb 6D1 (anti-rat CD59 antibody). In the treatment groups, soluble CR1 (sCR1) or C5a receptor (C5aR) antagonist was administered intra-articularly or intravenously and effects on the course of the acute synovitis were monitored. Synovitis induced by 6D1 was characterized by joint swelling, thickening of synovial tissue, cellular infiltration and deposition of membrane attack complex (MAC) on the synovial surface. Neither inflammatory change nor MAC deposition was found in rats which received an i.a. injection of sCR1 to suppress complement activity in the joint. Intra-articular injection of sCR1 did not reduce plasma complement activity. Intravenous administration of sCR1 suppressed plasma complement activity but had no effect on the course of the arthritis and synovitis with MAC deposition was observed. Neither i.a. nor i.v. injection of C5aR antagonist had any suppressive effects on inflammatory change or MAC deposition in synovium. The data show that inflammatory change induced by 6D1 was mediated by local complement activation and was not accompanied by systemic complement activation. C5a generation was not responsible for the observed inflammation, suggesting that other complement activation products, possibly MAC, mediate the inflammatory change observed in this model of acute synovitis in rats. 相似文献