全文获取类型
收费全文 | 17719篇 |
免费 | 1566篇 |
国内免费 | 778篇 |
专业分类
耳鼻咽喉 | 112篇 |
儿科学 | 214篇 |
妇产科学 | 106篇 |
基础医学 | 2308篇 |
口腔科学 | 292篇 |
临床医学 | 1027篇 |
内科学 | 2400篇 |
皮肤病学 | 102篇 |
神经病学 | 1673篇 |
特种医学 | 335篇 |
外国民族医学 | 4篇 |
外科学 | 1111篇 |
综合类 | 2337篇 |
现状与发展 | 3篇 |
一般理论 | 1篇 |
预防医学 | 1508篇 |
眼科学 | 306篇 |
药学 | 3391篇 |
7篇 | |
中国医学 | 2311篇 |
肿瘤学 | 515篇 |
出版年
2024年 | 139篇 |
2023年 | 423篇 |
2022年 | 997篇 |
2021年 | 1082篇 |
2020年 | 820篇 |
2019年 | 620篇 |
2018年 | 536篇 |
2017年 | 547篇 |
2016年 | 546篇 |
2015年 | 535篇 |
2014年 | 860篇 |
2013年 | 1132篇 |
2012年 | 939篇 |
2011年 | 974篇 |
2010年 | 739篇 |
2009年 | 760篇 |
2008年 | 762篇 |
2007年 | 741篇 |
2006年 | 618篇 |
2005年 | 550篇 |
2004年 | 444篇 |
2003年 | 422篇 |
2002年 | 336篇 |
2001年 | 280篇 |
2000年 | 243篇 |
1999年 | 241篇 |
1998年 | 237篇 |
1997年 | 228篇 |
1996年 | 206篇 |
1995年 | 235篇 |
1994年 | 197篇 |
1993年 | 183篇 |
1992年 | 161篇 |
1991年 | 170篇 |
1990年 | 153篇 |
1989年 | 147篇 |
1988年 | 152篇 |
1987年 | 172篇 |
1986年 | 169篇 |
1985年 | 208篇 |
1984年 | 187篇 |
1983年 | 128篇 |
1982年 | 166篇 |
1981年 | 144篇 |
1980年 | 149篇 |
1979年 | 96篇 |
1978年 | 83篇 |
1977年 | 63篇 |
1976年 | 60篇 |
1975年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
M. R. Wang C. Y. Chai J. S. Kuof 《Clinical and experimental pharmacology & physiology》1994,21(1):21-29
1. In chloralose-urethane anaesthetized cats, the dorsal cardiovascular reactive area (DCRA) in the parvocellular reticular nucleus dorsomedial to the facial nucleus, and the ventral cardiovascular reactive area (VCRA) ventromedial to the facial nucleus, were stimulated by microinjections of sodium glutamate (100–200 nmol) or electric current. 2. Stimulation of DCRA, with a long latency of 15–20 s, elicited a marked increase of blood flow in the contralateral femoral artery with little change to moderate increase in systemic arterial blood pressure (ABP). In the relatively dorsal portion of DCRA, however, a smaller increase of blood flow in the ipsilateral femoral artery was elicited. 3. On the other hand, stimulation of VCRA with a short latency (3–5 s) evoked an increase of blood flow in both femoral arteries which was more prominent on the contralateral side. The responses were accompanied with decreases in the blood flow of other vascular beds with only a slight increase or minimal change in ABP. 4. The data suggest that DCRA and VCRA are both viscerotopically organized to alter the resistance of individual vascular beds for redistribution of blood flow. 相似文献
42.
Yasuhiro Yamaoka Takatomo Mine Hiroshi Tanaka Yoichiro Ishida Tosihiko Taguchi 《Knee surgery, sports traumatology, arthroscopy》2007,15(11):1346-1349
An avulsion fracture of the tibial tubercle is a common injury in traffic accident. If the fracture is closed, then a comparatively
good prognosis can be expected through reinforcement of the bone via osteosynthesis and the use of artificial ligaments. In
this case, an open wound was observed in the tibial tubercle, and the wound was so polluted that the healing process was significantly
delayed. It was therefore difficult to provide simultaneous surgical treatment and so three operations were required to perform
the reconstruction of the extensor mechanism. The reconstruction of extensor mechanism and the frame fixation between the
patella and tibia was performed. Six months after the injury, the patient was able to walk without aid, had a range of movement
from 5°to 130°, and did not show any indications of ADL disorder. Using this method of frame fixation between the patella
and tibia proved to be an effective technique for the reconstruction of the open knee extension mechanism injury. 相似文献
43.
Objective: To study the rapid effect of glucocorticoids (GCs) on NMDA receptor activity in hippocampal neurons in stress and to elucidate its underlying probable membrane mechanisms. Methods: Whole-cell patch-clamp recording was used to assess the effect of stress concentration corticosterone (B) on the responses of cultured hippocampal neurons to glutamate and NMDA (N-methy-D-asparatic acid). To make clear the target of B, intracellular dialysis of B(10μmol/L)through patch pipette and extracellular application of bovine serum albumin-conjugated corticosterone (B-BSA, 10μmol/L)were carried out to observe their influence on peak amplitude of NMDA-evoked current. Results: B had a rapid, reversible and inhibitory effect on peak amplitude of GLU-or NMDA-evoked current in cultured hippoeampal neurons. Furthermore, B-BSA had the inhibitory effect on INMDA as that of B, but intraeeUularly dialyzed B had no significant effect on INMDA. Conclusion: These results suggest that under the condition of stress, GCs may rapidly, negatively regulate excitatory synaptic receptors-glutamate receptors (GluRs), especially NMDA receptor (NMDAR) in central nervous system, which is mediated by rapid membrane mechanisms, but not by classical, genomic mechanisms. 相似文献
44.
利用石英弹簧称重法测定了308.15K时乙醇和苯在含端羟基聚丁二烯(HTPB)和端羟基聚丁二烯/丙烯腈共聚物(HTBN)的嵌段共聚聚氨酯膜中的吸收动力学曲线。结合吸收-络合吸附双模式传递模型,研究了聚氨酯膜的微相分离程度、软硬段的比例和组成以及软段分子量等因素对溶剂在膜中溶解和传递性质的影响。 相似文献
45.
外源性核苷能抵消抗代谢药对肿瘤细胞的杀伤作用;核苷转运抑制剂潘生丁则能阻断核苷的这种抵消作用,从而增强抗代谢药的细胞毒性。本研究证明,胸苷和次黄嘌呤可明显抵消氨甲蝶呤对L1210细胞的杀伤作用,潘生丁则能有效地阻断核苷的抵消作用;潘生丁和两性霉素B合用可明显增强氨甲蝶呤对小鼠S180肉瘤的抑制作用,但不增强氨甲蝶呤对动物的毒性。提示潘生丁有可能应用于肿瘤联合化疗。 相似文献
46.
Lü Zhuo-ren 《中国人民解放军军医大学学报》2006,21(5)
Objective: To compare renal sodium transport, using fractional excretions of lithium(FELi) as a marker of proximal tubule sodium reabsorption, between hypertensive and non-hypertensive ouabain-treated rats and further to elucidate the role of ouabain in pathogenesis of hypertension. Methods: Thirty male Sprague-Dawley rats weighting 180-200 g were randomly divided into normal control group and ouabain treated group. Rats were infused with 1 ml/kg·d normal saline or 27. 8μg/kg·d ouabain in-traperitoneally once a day respectively. Systolic blood pressure (SBP), heart rate and body weight were recorded weekly. Rats were sacrificed 6 weeks after treatment. Blood and 24-hour urine sample were collected to measure the serum and urinary concentration of sodium, trace lithium and creatinine. Endogenous creatinine clearance rate(Ccr), fractional excretions of sodium (FENa), fractional excretions of lithium (FELi) and fractional reabsorption of sodium in the postproximal tubules (FDRNa) were calculated. Ouabain levels of plasma and renal tissue, plasma renin activity, angiotensin I and aldosterone concentration were determined. Results: 65% of the ouabain-treated rats achieved significantly higher SBP after 4 weeks, compared with that of the saline control groups or self baseline (P<0. 01). But in the other 35% of the ouabain-treated rats, their SBP was similar with control group during the experiment (P>0. 05). The body weight, heart rate and food intake between the 3 groups were no significant differences (P> 0. 05). FELi and FDRNa were significantly lower in ouabain-hypertensive group compared with ouabain-non-hypertensive group and control group(P<0. 01 and P<0. 05). The FEu and FDRn, of ouabain-nonhyper-tensive groups were similar with control group(P>0. 05). Ccr and FENa were comparable between the 3 groups (P>0. 05). Plasma and renal tissue ouabain levels, plasma renin activity, angiotensin I and aldosterone contents in ouabain-hypertensive rats were comparable with ouabain-nonhypertensive rats. Conclusion: Increase of proximal tubule sodium reabsorption play an important role in the pathogenesis of ouabain-hypertensive rats. The change of renal sodium transport may result from regulation to renal Na+ , K + -ATPase by ouabain. 相似文献
47.
99Tcm-DMSA肾皮质显像诊断小儿肾发育不良 总被引:2,自引:0,他引:2
目的 探讨^99Tc^m—二巯基丁二酸(DMSA)肾皮质显像诊断小儿肾发育不良的价值。方法 疑为肾发育不良患儿29例,行常规^99Tc^m—DMSA肾皮质显像和腹部B超检查。图像分析:将发育不良肾分为0~4级。结果 ^99Tc^m—DMSA肾皮质显像示29例患儿中24例为单侧肾发育不良,其中11例1级,7例2级,6例3级,余5例患肾未显影为0级,结合其他:检查诊断为肾发育不良。患肾分肾功能为0~24.9%(平均6.3%)。29例患儿中24例患肾肾皮质显像诊断为肾发育不良,5例患肾未显影,由其他影像学方法确诊,诊断灵敏度为82.76%。29例中19例经手术治疗,病理检查证实为肾发育不良。结论 ^99Tc^m—DMSA肾皮质显像诊断肾发育不良灵敏度高、可靠,可确定发育不良肾部位和判断肾功能。 相似文献
48.
目的:通过观察妇宝胶囊对动物出凝血时间、血液凝固系统的影响,探讨妇宝胶囊的止血机制。方法:采用毛细玻璃管法测定小鼠凝血时间(CT),用断尾法测定出血时间(BT);用ACL-200型血液凝集仪测定大鼠凝血酶原时间(PT)和部分凝血活酶时间(APTT)。结果:妇宝胶囊能明显缩短小鼠CT、BT,缩短大鼠PT和APTT。结论:妇宝胶囊的止血机制主要通过促进内源性和外源性凝血系统,抑制纤维蛋白溶解系统达到目的。 相似文献
49.
张玲 《右江民族医学院学报》2004,26(4):482-484
目的 探讨失眠症患者心理防御特征和社会支持 ,并分析两者的关系。方法 采用心理防御方式问卷 (DSQ )、社会支持评定量表 (SSRS)对失眠症患者和正常健康者各 5 0例进行评定。结果 患者组心理防御方式 (不成熟型、中间型防御因子和掩饰因子的因子分高 ,成熟防御因子分低 )和社会支持 (社会支持总分、主观支持分、对支持利用度低 )与对照组相比差异有显著性 (P <0 .0 5或 0 .0 1) ;相关分析发现 ,患者组不成熟防御机制与SSRS的支持总分、主观支持分、对支持利用度呈负相关 (P均 <0 .0 5 ) ,中间型防御机制与SSRS的主观支持呈负相关 (P <0 .0 5 )。结论 失眠症患者心理防御机制的成熟程度较正常人低 ,社会支持差 ,两者存在一定的关系。 相似文献
50.
The subdivisions of the sacral intermediolateral nucleus (IML) of the cat have been studied by using a double-labeling technique of retrograde Fluoro-gold (FG) and wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) tracing. The parasympathetic preganglionic neurons (PGNs) that were labeled by the FG injected into the pelvic nerve formed a ‘V’-shaped column known as the sacral parasympathetic nucleus (SPN) in the sacral IML. The neurons that were labeled by the WGA-HRP applied to the lateral parabrachial nucleus (PBL) formed an elongated spindle-shaped column extending throughout the IML of the sacral segments. We designated it by the name of sacral visceral sensory nucleus (SVSN). These findings indicate that the sacral IML of the cat contain two distinct subdivisions, SPN and SVSN. 相似文献