全文获取类型
收费全文 | 45897篇 |
免费 | 3534篇 |
国内免费 | 2853篇 |
专业分类
耳鼻咽喉 | 515篇 |
儿科学 | 639篇 |
妇产科学 | 456篇 |
基础医学 | 4174篇 |
口腔科学 | 582篇 |
临床医学 | 5933篇 |
内科学 | 5405篇 |
皮肤病学 | 519篇 |
神经病学 | 1904篇 |
特种医学 | 1648篇 |
外国民族医学 | 16篇 |
外科学 | 3861篇 |
综合类 | 10229篇 |
现状与发展 | 8篇 |
一般理论 | 1篇 |
预防医学 | 4129篇 |
眼科学 | 1240篇 |
药学 | 5459篇 |
55篇 | |
中国医学 | 2621篇 |
肿瘤学 | 2890篇 |
出版年
2024年 | 58篇 |
2023年 | 321篇 |
2022年 | 1073篇 |
2021年 | 1561篇 |
2020年 | 1316篇 |
2019年 | 1054篇 |
2018年 | 1075篇 |
2017年 | 1303篇 |
2016年 | 1090篇 |
2015年 | 1880篇 |
2014年 | 2539篇 |
2013年 | 2684篇 |
2012年 | 3907篇 |
2011年 | 4387篇 |
2010年 | 3397篇 |
2009年 | 2871篇 |
2008年 | 3387篇 |
2007年 | 3075篇 |
2006年 | 2983篇 |
2005年 | 2437篇 |
2004年 | 1895篇 |
2003年 | 1739篇 |
2002年 | 1449篇 |
2001年 | 1089篇 |
2000年 | 847篇 |
1999年 | 625篇 |
1998年 | 400篇 |
1997年 | 384篇 |
1996年 | 297篇 |
1995年 | 243篇 |
1994年 | 245篇 |
1993年 | 126篇 |
1992年 | 127篇 |
1991年 | 108篇 |
1990年 | 56篇 |
1989年 | 49篇 |
1988年 | 57篇 |
1987年 | 38篇 |
1986年 | 23篇 |
1985年 | 26篇 |
1984年 | 19篇 |
1983年 | 6篇 |
1982年 | 4篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1974年 | 5篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1949年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
61.
利用透射式电子显微镜观察小儿喘咳液对过敏性哮喘豚鼠肺超微结构变化情况。结果显示:连续雾化吸入卵清蛋白后第1d肺毛细血管壁充血并挤压毛细血管壁,第8d肺毛细血管壁增厚,胶原纤维增生。而用小儿喘咳液连续治疗7d后肺毛细血管壁增厚程度减轻,无胶原纤维增生。证明小儿喘咳液对哮喘有良好的治疗效果。 相似文献
62.
目的:分析住院病人焦虑的原因,有效地减轻住院病人的焦虑程度。方法:使用焦虑自评量表(SAS)及问卷对347例住院病人进行焦虑原因的调查分析。结果:问卷20题中有13项肯定组与否定组的SAS评分存在显著差异或非常显著差异;不同年龄、不同文化程度、不同住院时间、治疗费用不同支出方式的住院病人SAS评分也存在显著差异。结论:明确住院病人焦虑原因,可有针对性地对其做好心理护理。 相似文献
63.
ThecoronaryarterycomplicationcouldbefoundinalmostalcasesofKawasakidisease[1].Ithasrecentlybeenshownthatplatelet-derivedgrowth... 相似文献
64.
65.
急性非淋巴细胞白血病中MGMT与p53基因突变的研究 总被引:1,自引:0,他引:1
目的 探讨肿瘤抑制基因p53、MGMT在急性非淋巴细胞白血病(ANLL)中的改变。方法 用聚合酶链反应-单链构象多态性(PCR-SSCP)技术对31例ANLL患者、22例正常人p53基因第5、6、7、8外显子和MGMT基因第1、4外显子进行突变分析。结果 31例ANLL中5例存在p53基因突变、4例存在MGMT基因突变,其中2例p53与MGMT同时发生突变。结论 p53基因突变在白血病发生中起一定 相似文献
66.
增生性玻璃体视网膜病变玻璃体切割物的细胞凋亡观察 总被引:1,自引:0,他引:1
目的观察增生性玻璃体视网膜病变玻璃体切割物的细胞凋亡情况 。方法收集60例不同分级的增生性玻璃体视网膜病变患者的玻璃体切割物,核苷酸末端转移酶介导dUTP缺口翻译法(TdT-mediated dUTP nick end label ling method,TUNEL法)标记凋亡细胞,光镜观察。结果60例患者的玻璃体切割物均有细胞凋亡的特征性改变,随着病变程度的加重,非色素细胞凋亡总数逐渐减少,并出现色素细胞凋亡。结论增生性玻璃体视网膜病变存在不同类型细胞的凋亡,细胞凋亡是调控其病变程度的重要机制之一。(中华眼底病杂志,1999,15:81-83) 相似文献
67.
Purpose. The human plasma binding of cyclosporin A was studied in vitro using the technique of microdialysis. The effect of temperature on the overall binding interaction between cyclosporin A and human plasma was also investigated.
Methods. Flow-through loop-type microdialysis probes were constructed from fused silica tubing and regenerated cellulose tubing with a MWCO of 13000 daltons. Probes were perfused with phosphate buffer (0.5 µl/min) and the concentration of 3H-cyclosporin A in the well-mixed medium (plasma or buffer) was 1200 ng/ml. Relative recoveries of cyclosporin A from plasma or buffer were determined for each probe by separate experiments to measure the solute gain or loss with reference to the perfusate.
Results. Recoveries determined by loss were significantly greater than those determined by gain and in each case temperature dependent, with higher recoveries at higher temperatures. The plasma free fraction of cyclosporin A calculated from the recovery data and the perfusate to plasma concentration ratios was dependent on temperature in a log-linear fashion. Mean ± s.d. plasma free fractions expressed in percent were 33.5 ± 4.6, 17.9 ± 3.6, 6.2 ± 0.8, 3.0 ± 0.6, and 1.5 ± 0.2 at temperatures of 4, 10, 20, 30, and 37°C, respectively. Assuming that the enthalpy of binding is constant over the temperature range studied and pseudo-first order conditions exist, the binding reaction at these temperatures was spontaneous, endothermic (H = 74.0 kJ/mole), and entropically driven (S = 0.274 kJ/mole/deg).
Conclusions. These results show that the free fraction of cyclosporin A in human plasma is dependent on temperature with the fraction unbound decreasing with temperature in the range of 4 to 37°C. The thermodynamic parameters for the binding of cyclosporin A to plasma components indicate that the reaction is a spontaneous endothermic reaction that is mainly entropy driven, similar to the partitioning of lipophilic molecules from an aqueous to a hydrophobic phase. Moreover, these results show that microdialysis is a feasible method to determine the binding interactions between plasma and cyclosporin A, which indicates the method may be suitable for other difficult binding studies where the solutes have nonspecific binding to separation devices. 相似文献
68.
从1972年11月到1994年3月,401例髋臼骨折病人中的99例经手术治疗并获随访,包括30例双柱骨折,13例横骨折伴后壁骨折,9例后壁骨折,9例后柱骨折,9例前往骨折伴前壁骨折,13例T形骨折和16例横骨折.平均随访时间为7年(2~14).外科手术入路的选择,后入路53次,髂腹股沟入路23次,延长的髂股骨入路11次,放射状入路9次和结合性入路6次.复位情况用X线平片来评判,解剖复位的有59例(59.6%),接近解剖复位(<2mm的错位)的有19例(19.2%).总结果用Harris Hip Score来评判,优秀的有53例(53.5%),良好的有25例(25.3%),一般的有14例(14.1%),差的有7例(7%).并发症中,有10例(53%)为感染,7例(37%)为静脉栓塞.这些结果表明,对于错位严重的髋臼骨折,切开复位内固定是一种可以选择的治疗方法. 相似文献
69.
Biochemical and metabolic indicators were monitored in a group of volunteers suffering from a variety of chronic illnesses participating in a week's course on a special uncooked vegetable diet, known as "living food". Unmatched healthy controls ate the same diet cooked for 2 min in a microwave oven. After 1 week on the regimen, serum protein and urea contents decreased and alanine aminotransferase (ALAT) activity increased in both groups, although all within the normal range. Blood glucose increased in both groups to slightly above normal limits but total serum cholesterol dropped about 1 mmol/l from normal starting levels. Serum tocopherol and retinol increased only in the group eating the uncooked diet. In both groups urinary sodium dropped drastically without a significant change in potassium. Serum and urinary phenol and p-cresol diminished also significantly. It is concluded that this vegetable diet may be of some benefit in the short term but any longer-term use requires evaluation. 相似文献
70.
Electron microscopical and immunohistochemical studies on the induction of "Qi" employing needling manipulation. 总被引:3,自引:0,他引:3
M Kimura K Tohya K Kuroiwa H Oda E C Gorawski Z X Hua S Toda M Ohnishi E Noguchi 《The American journal of Chinese medicine》1992,20(1):25-35
During a sparrow-pecking and twisting-needle manipulation to the acupoints BL 23, 24 and 25 for an induction of "Qi", it was found that some transparent materials were binding to the needles after removed from the volunteer's skin. Electron-microscopical analysis of the transparent materials revealed that they corresponded to the injured fascia made up of collagen fibers, elastic fibers, fibroblasts, adipocytes and mast cells. Rarely were nerve fiber-like structures observed in the materials. Immunohistochemically, calcitonin gene-related peptide-positive nerve fibers could be demonstrated in the acupoint BL 24 associated fascia. A possible functional relationship between the needle manipulation and the induction of Qi-sensation is discussed along with the acupoint tissue constitution. 相似文献