全文获取类型
收费全文 | 116040篇 |
免费 | 5909篇 |
国内免费 | 138篇 |
专业分类
耳鼻咽喉 | 1771篇 |
儿科学 | 5196篇 |
妇产科学 | 3928篇 |
基础医学 | 16053篇 |
口腔科学 | 2901篇 |
临床医学 | 8306篇 |
内科学 | 21964篇 |
皮肤病学 | 3355篇 |
神经病学 | 8973篇 |
特种医学 | 5043篇 |
外国民族医学 | 32篇 |
外科学 | 19014篇 |
综合类 | 1595篇 |
一般理论 | 29篇 |
预防医学 | 5803篇 |
眼科学 | 3390篇 |
药学 | 8041篇 |
中国医学 | 323篇 |
肿瘤学 | 6370篇 |
出版年
2018年 | 889篇 |
2017年 | 776篇 |
2016年 | 1094篇 |
2015年 | 1220篇 |
2014年 | 1601篇 |
2013年 | 2363篇 |
2012年 | 3094篇 |
2011年 | 3143篇 |
2010年 | 1969篇 |
2009年 | 1927篇 |
2008年 | 3250篇 |
2007年 | 3486篇 |
2006年 | 3630篇 |
2005年 | 3746篇 |
2004年 | 3689篇 |
2003年 | 3554篇 |
2002年 | 3504篇 |
2001年 | 7013篇 |
2000年 | 6957篇 |
1999年 | 5857篇 |
1998年 | 1622篇 |
1997年 | 1559篇 |
1996年 | 1335篇 |
1995年 | 1201篇 |
1994年 | 1091篇 |
1993年 | 1119篇 |
1992年 | 3765篇 |
1991年 | 3575篇 |
1990年 | 3561篇 |
1989年 | 3348篇 |
1988年 | 2985篇 |
1987年 | 2894篇 |
1986年 | 2803篇 |
1985年 | 2617篇 |
1984年 | 1943篇 |
1983年 | 1594篇 |
1982年 | 927篇 |
1981年 | 915篇 |
1980年 | 765篇 |
1979年 | 1822篇 |
1978年 | 1346篇 |
1977年 | 1111篇 |
1976年 | 936篇 |
1975年 | 1178篇 |
1974年 | 1212篇 |
1973年 | 1198篇 |
1972年 | 1040篇 |
1971年 | 975篇 |
1970年 | 880篇 |
1969年 | 787篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
941.
Immunohistochemical characterization of an anti-epithelial monoclonal antibody (mAB lu-5) 总被引:7,自引:0,他引:7
J. von Overbeck C. Stähli F. Gudat H. Carmann C. Lautenschlager U. Dürmüller B. Takacs V. Miggiano Th. Staehelin Ph. U. Heitz 《Virchows Archiv : an international journal of pathology》1985,407(1):1-12
Summary A mouse monoclonal antibody (mAB lu-5) was prepared using a lung cancer cell line as an antigen. The selected clone produces an IgG with a gamma-1 heavy chain and a kappa-light-chain. Immunohistochemical testing of mAB lu-5 on 117 normal tissue biopsies and 474 tumours revealed reactivity with an intracytoplasmic, formaldehyderesistant antigen present in most epithelial and mesothelial cells, but absent in mesenchymal cells. The antibody can therefore be used as a first order, pan-epithelial marker. It proved also useful for fast tumour diagnosis on frozen sections. 相似文献
942.
A novel factor was found in the medium conditioned by SV40-transformed human embryo fibroblasts, which stimulate concanavalin A-induced thymocyte DNA synthetic response. This activity was estimated to be 10-15 kD and divided into two activities by ion exchange chromatography. One of them is a protein molecule and the other is a glycoprotein. In addition, these activities are not derived from the growth factors reported previously such as interleukin 2 (Morgan, R., Ruscetti, F. and Gallo, R. C. (1976) Science 193, 1007-1008) and transforming growth factor (De Larco, J. E. and Todaro, G. J. (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 4001-4005). 相似文献
943.
The effect of temporary position changes, sitting up from supine, on extracellular (ECW) and intracellular (ICW) resistances and fluid volumes calculated from whole body bioimpedance using a Xitron 4200 impedancemeter was investigated on 8 patients during dialysis for a total of 11 tests. It was found that ECW resistance decreased instantaneously by an average of 2.3% when the patient sits up, due to plasma and interstitial fluid shift into the legs which decreases leg resistance, the major contributor to total resistance. This drop in resistance is incorrectly interpreted by the device as an increase in ECW volume which averages 235 ml. But this effect is completely reversible and both ECW resistance and fluid volume rapidly resume their normal course when the patient returns to his initial position. No significant variation in ICW resistance was observed in any of the patients at the position change. We conclude that segmental impedance, which has been proposed to minimize this artifact, is not advisable in dialysis monitoring and that it is simpler to ignore or switch off measurements during the position change so that later data are not affected by it. 相似文献
944.
945.
946.
Bone marrow examination for the diagnosis of mycobacterial and fungal infections in the acquired immunodeficiency syndrome. 总被引:4,自引:0,他引:4
L Nichols B Florentine W Lewis F Sattler M U Rarick R K Brynes 《Archives of pathology & laboratory medicine》1991,115(11):1125-1132
In a series of 342 bone marrow examinations from 314 patients with human immunodeficiency virus infection, 70 examinations (20%) detected opportunistic mycobacterial or fungal infections. One hundred eleven of the 314 patients had such infections, and, hence, 63% (70/111) were detected by bone marrow examination. Special stains for microorganisms detected 16 (32%) of 50 Mycobacterium avium complex infections, 10 (22%) of 45 Mycobacterium tuberculosis infections, eight (73%) of 11 Histoplasma capsulatum infections, and five (83%) of six Cryptococcus neoformans infections. Bone marrow cultures detected 36 (72%) of the 50 M avium complex infections, 13 (29%) of the 45 M tuberculosis infections, and 63% of the fungal infections. Marrow examination revealed infection in only one of the 70 specimens (1%) collected to evaluate thrombocytopenia alone or hematologic malignancy, but in 69 (25%) of 274 with fever, neutropenia, anemia, or miscellaneous other indications for marrow examination. Granulomas were detected in 102 (30%) of the biopsy specimens, including 71 (64%) of those in cases with mycobacterial or fungal infection. The granulomas showed caseous necrosis in nine cases, all in patients with tuberculosis, and the 27 cases with tuberculosis-associated granulomas tended to show large, tightly cohesive granulomas. The presence of granulomas correlated with opportunistic infection in 82 (80%) of 102 cases. Without granulomas, special stains were positive in only eight (3%) of 240 specimens. These results suggest that (1) bone marrow granulomas are a common and valuable histologic clue to opportunistic infection; (2) without them, special stains may not be a cost-efficient way to diagnose such infection; and (3) bone marrow examination can be a useful method of diagnosing opportunistic mycobacterial and fungal infections in patients with fever, anemia or neutropenia, and underlying human immunodeficiency virus infection. 相似文献
947.
948.
Adrenal chromaffin cells, obtained from a therapeutically aborted human fetus of about 11 weeks gestation, were cultured for 3 weeks in vitro and then transplanted to the striatum of rats. Transplanted cells became established through strands of tissue growing into the host striatum. No signs of inflammation or rejection were observed up to the time of sacrifice one month post-transplantation. Histofluorescence examination of the implanted areas showed many clusters of cells having an intensely positive catecholamine fluorescence with some of the cells developing conspicuous processes. This study, showing survival of cultured human adrenal chromaffin cells transplanted into rat brain tissue, might indicate the feasibility of using cultured human material for future human neuronal transplantation studies as a therapeutic measure. 相似文献
949.
Structural and mechanical adaptations in response to sustained changes in arterial pressure were studied on abdominal aorta of the male rat. Two models were used: 1. Aortic ligature (L), immediately below the renal arteries producing hypotension distal to the knot (duration before sacrifice 6 weeks or 3 months). 2. One-clip renal hypertensive rats (H) (duration 6 weeks). Normotensive sham-operated rats (C) served as controls. At sacrifice mean tail artery pressure was L: 58 +/- 1, C: 110 +/- 3, and H: 163 +/- 5 mmHg (SE, N=6). Segments of abdominal aorta were mounted in vitro for determination of their length-tension relations (activation: High-K+ solution with 2.5 mM Ca2+). At end of experiments the vessels were supramaximally stimulated at optimal circumference (1o) for active force (activation: High-K+ solution with 10 mM Ca2+, and 10(-5) M noradrenaline), and then fixated for light and electron microscopy. Passive and active length-tension relations were shifted towards lower and higher circumference values for hypo- and hypertensive vessels, respectively. The 1o values were L: 3.60 +/- 0.13, C: 4.44 +/- 0.19, and H: 4.91 +/- 0.29 mm. The media thickness at 1o was reduced in L: 56.0 +/- 3.3, and increased in H: 81.3 +/- 2.4 compared to C: 73.4 +/- 1.8 micron. Maximal active wall stress was L: 46.6 +/- 9.8, C: 74.2 +/- 7.0, and H: 83.8 +/- 7.7 mN/mm2. Intracellular volume (ICV) in the media was L: 30 +/- 2, C: 45 +/- 3, and H: 44 +/- 1% (n=4 for each).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
950.
Santer R Muhle H Suormala T Baumgartner ER Duran M Yang X Aoki Y Suzuki Y Stephani U 《Molecular genetics and metabolism》2003,79(3):160-166
We report the clinical course and biochemical findings of a 10-year-old, mentally retarded girl with late-onset holocarboxylase synthetase (HCS, gene symbol HLCS) deficiency and only partial response to biotin. On treatment, even with an unusually high dose of 200mg/day, activities of the biotin-dependent mitochondrial carboxylases in lymphocytes remained below 50% of the mean control values. Not only urinary 3-hydroxyisovaleric acid excretion has been persistently elevated, but also plasma and, with even higher concentrations, cerebrospinal fluid 3-hydroxyisovaleric acid have not normalized. The unusual and insufficient response of this patient to biotin treatment can be explained by the effect of the combination of the common HLCS allele IVS10 +5 g>a on one chromosome and a truncating mutation on the other. This case illustrates mechanisms involved in the genotype-phenotype correlation that unequivocally exists in HCS deficiency. 相似文献