全文获取类型
收费全文 | 98092篇 |
免费 | 4564篇 |
国内免费 | 1485篇 |
专业分类
耳鼻咽喉 | 533篇 |
儿科学 | 1508篇 |
妇产科学 | 1020篇 |
基础医学 | 11359篇 |
口腔科学 | 3994篇 |
临床医学 | 9046篇 |
内科学 | 20479篇 |
皮肤病学 | 1917篇 |
神经病学 | 6847篇 |
特种医学 | 2555篇 |
外国民族医学 | 7篇 |
外科学 | 14488篇 |
综合类 | 7360篇 |
现状与发展 | 7篇 |
一般理论 | 5篇 |
预防医学 | 7333篇 |
眼科学 | 1712篇 |
药学 | 6914篇 |
23篇 | |
中国医学 | 3411篇 |
肿瘤学 | 3623篇 |
出版年
2023年 | 1347篇 |
2022年 | 2245篇 |
2021年 | 3788篇 |
2020年 | 2781篇 |
2019年 | 6764篇 |
2018年 | 6910篇 |
2017年 | 4524篇 |
2016年 | 1877篇 |
2015年 | 1847篇 |
2014年 | 3455篇 |
2013年 | 3779篇 |
2012年 | 2643篇 |
2011年 | 2996篇 |
2010年 | 2554篇 |
2009年 | 2220篇 |
2008年 | 2316篇 |
2007年 | 2305篇 |
2006年 | 1999篇 |
2005年 | 1803篇 |
2004年 | 1544篇 |
2003年 | 1608篇 |
2002年 | 1218篇 |
2001年 | 1227篇 |
2000年 | 1068篇 |
1999年 | 979篇 |
1998年 | 804篇 |
1997年 | 805篇 |
1996年 | 669篇 |
1995年 | 683篇 |
1994年 | 620篇 |
1993年 | 512篇 |
1992年 | 478篇 |
1991年 | 437篇 |
1990年 | 371篇 |
1989年 | 338篇 |
1988年 | 334篇 |
1987年 | 278篇 |
1985年 | 3124篇 |
1984年 | 3637篇 |
1983年 | 3025篇 |
1982年 | 3525篇 |
1981年 | 3195篇 |
1980年 | 2635篇 |
1979年 | 2580篇 |
1978年 | 2103篇 |
1977年 | 1587篇 |
1976年 | 2034篇 |
1975年 | 1527篇 |
1974年 | 1333篇 |
1973年 | 1279篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
云南白药对血小板活化的研究 总被引:9,自引:0,他引:9
罗琪 《福建中医学院学报》2004,14(2):12-14
为探讨云南白药对血小板活化的影响 ,应用单克隆抗体法 ,并用流式细胞仪对 2 0 6例男性腹股沟斜疝患者血小板活化分子标志物进行检测 ,同时检测血浆凝血物质和 D-二聚体含量。结果显示 :服药组血小板明显活化与对照组比较有显著性差异 ( P<0 .0 5 ) ,凝血物质和 D-二聚体与对照组比较无差异 ( P>0 .0 5 )。结论 :云南白药能增加血小板活化 ,促进局部止血 ,但它不影响凝血物质和 D-二聚体的含量 ,不增加血栓形成的危险。 相似文献
32.
Gregory J. Pomper Rita A. Joseph Erica L. Hartmann Michael S. Rohr Patricia L. Adams Robert J. Stratta 《American journal of transplantation》2005,5(10):2586-2589
Massive immune hemolysis due to passenger lymphocyte-derived anti-D has not been reported in renal transplantation. A 50-year-old (B-positive) male received a dual deceased-donor kidney transplant (B-negative) for diabetic renal failure. Two weeks post-transplant, the patient developed severe hemolytic anemia. The donor anti-D titer was 1:8. The recipient anti-D titer (zero pre-transplant) increased from 1:4 to 1:16 over 4 days. Rapid hemolysis caused severe anemia, minimum Hb = 4.2 g/dL, while selectively lysing the patient's autologous red cells during this time. The hemolytic anemia did not impair the allografts and subsided without monoclonal B-cell pharmacotherapy or apheresis. The anti-D titer decreased to barely detectable levels at four months and had cleared when checked 2 years post-transplant. Transfusion support subsided after two months. If complications of anemia can be avoided, the deleterious effects of hemolysis may be well tolerated by renal allografts using antigen negative transfusion alone. 相似文献
33.
The goals of this report are: 1) to review the number needed to treat (NNT) concept, which, although well established in many sectors of medicine, is still relatively new to the radiotherapy community; 2) to discuss several clinical radiotherapy examples illustrating the inherent advantages of the NNT approach; and 3) to discuss potential future roles of the NNT concept within radiotherapy. 相似文献
34.
A simulation study of three sequential methods for the comparison of two treatment groups when the response criterion is censored 总被引:1,自引:0,他引:1
Three recent sequential methods, group sequential analysis (GSA), the sequential probability ratio test (SPRT) and the triangular test (TT) are well suited to randomized clinical trials with a censored response criterion, as they do not require matched pairs of patients. We undertook a simulation study to investigate their statistical properties and to compare these three methods with the fixed-sample design. Our results suggest that the three methods have the expected statistical properties for size and power; they allow an important reduction of the average number of events before stopping, except with GSA when there is no treatment difference; the triangular test (closed design) appears the optimal design, as the variance of the number of events is smaller than with the sequential probability ratio test (open design) and analysis after every twenty new events does not alter the statistical properties of these sequential methods and enhances their usefulness. 相似文献
35.
茶色素对冠心病及高血压病病人血小板功能的影响 总被引:1,自引:0,他引:1
目的:探索茶色素对冠心病、高血压病病人血小板功能的影响。方法:冠心病病人36例(男性21例,女性15例;年龄64±s4a);高血压病病人30例(男性18例,女性12例;年龄58±8a)。采用茶色素250mg,po,tid,30d为一个疗程。结果:治疗后TXB2下降,6-keto-PGP1α上升,TXB2/6-keto-PGF1α比值下降(P<0.01或P<0.05),GMP-140下降(P<0.05),PagT,PadT下降(P<0.05)。结论:茶色素具有降低血小板表面活性作用,抑制血小板聚集和粘附,抗血栓形成,改善微循环,对冠心病和高血压病病人起到积极的防治作用。 相似文献
36.
The interactive role of mucosal T lymphocytes in intestinal growth, development and enteropathy 总被引:2,自引:0,他引:2
Abstract Over the past 15–20 years, research has progressively focused on the mucosal T cell as the central factor in the initiation of physiological or pathological changes, first in the growth and maturation of the early (postnatal) intestine, and second in adult-type enteropathies resulting from sensitivity to either food or pathogen-derived antigens. T cell-mediated events may be measured, for example, in terms of specific immunopathologic patterns of change and injury, such as type 1 (lymphocyte infiltration), type 2 (crypt hyperplasia) and type 3 (flat-destructive), which can be recognized and quantitated microscopically; by determination of lymphocyte reactivity through secretion of interleukin-2 receptors (IL-2R) into plasma or expression by mucosal lymphocytes; by quantitation of lymphocyte subsets emigrating into inflamed tissues by immunoperoxidase-labelled monoclonal antibodies; or by the determination of T cell receptor polymorphisms. Alterations in intestinal growth, structure and function at weaning are likely to be T cell-mediated as they are analogous to the same type 1/2 lesions that reflect modulation of adult mucosal architecture in food and parasite-induced hypersensitivity reactions. Enteropathies associated with HIV infection and T cell deficiency display a milder degree of villous flattening and impaired crypt hyperplasia than that typical of gluten-sensitivity, suggesting a reversion to lesser degrees of mucosal pathology (type 1/2). Clearly more information will accrue; meanwhile the remarks in this brief survey should provide a firm basis whereby clinician and scientist can meet, and together recognize and further dissect the modulatory effect of T lymphocytes on mucosal structure and function. 相似文献
37.
38.
N. Ya. Kovalenko D. D. Matsievskii Yu. V. Arkhipenko 《Bulletin of experimental biology and medicine》1998,126(4):983-987
Study of the dynamics of cardiac output in rats with different tolerance to acute massive blood loss showed that the pumping
ability of the heart remains intact during the entire posthemorrhagic period in all high-resistant and in 65% low-resistant
rats. In 35% rats that were low-resistant to blood loss, the cardiac output deficiency syndrome developed after cessation
of bleeding against the background fall in arterial pressure and a decrease in the hepatic blood flow, which are the signs
of rapid variant of the dysfunction produced by acute blood loss.
Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 10, pp. 384–388, October, 1998 相似文献
39.
单波长荧光分光光度计测定细胞内Ca^2+浓度的方法探索 总被引:2,自引:1,他引:1
在使用单波长荧光分光光度计测定细胞内游离钙浓度时,通过快速(4~6s)手动转换激发波长(EX),分别测定EX340和380nm时的荧光强度变化,并计算出340nm与380nm时的荧光强度比率(R),然后也采用双波长荧光分光光度计测定细胞内Ca2+浓度的计算公式计算细胞内游离钙浓度。结果显示单波长荧光分光光度计按比例法测得的细胞内游离Ca2+浓度与使用双波长荧光分光光度计测得的结果相似。 相似文献
40.
神经肽Y(NPY)是广泛分布于中枢神经系统和外周神经各部位的神经肽类物质。本实验观察NPY在体外对几种免疫细胞活性的直接作用。结果表明,NPY对小鼠T淋巴细胞丝裂原反应性和NK细胞的杀伤活性均无明显影响(P>0.05),对巨噬细胞分泌溶菌酶有明显抑制作用(P<0.05);而对B淋巴细胞丝裂原反应性则有明显的促进作用(P<0.05)。上述结果提示,NPY对部分免疫细胞功能的影响因细胞种类而异。 相似文献