全文获取类型
收费全文 | 38335篇 |
免费 | 3111篇 |
国内免费 | 1098篇 |
专业分类
耳鼻咽喉 | 363篇 |
儿科学 | 723篇 |
妇产科学 | 861篇 |
基础医学 | 5597篇 |
口腔科学 | 1031篇 |
临床医学 | 3532篇 |
内科学 | 7452篇 |
皮肤病学 | 667篇 |
神经病学 | 3194篇 |
特种医学 | 1545篇 |
外国民族医学 | 2篇 |
外科学 | 5083篇 |
综合类 | 2514篇 |
一般理论 | 11篇 |
预防医学 | 2244篇 |
眼科学 | 837篇 |
药学 | 3431篇 |
中国医学 | 433篇 |
肿瘤学 | 3024篇 |
出版年
2023年 | 148篇 |
2022年 | 307篇 |
2021年 | 610篇 |
2020年 | 341篇 |
2019年 | 539篇 |
2018年 | 861篇 |
2017年 | 674篇 |
2016年 | 641篇 |
2015年 | 837篇 |
2014年 | 1063篇 |
2013年 | 1377篇 |
2012年 | 1926篇 |
2011年 | 1868篇 |
2010年 | 1154篇 |
2009年 | 1042篇 |
2008年 | 1661篇 |
2007年 | 1702篇 |
2006年 | 1577篇 |
2005年 | 1401篇 |
2004年 | 1258篇 |
2003年 | 1114篇 |
2002年 | 932篇 |
2001年 | 2501篇 |
2000年 | 2377篇 |
1999年 | 1996篇 |
1998年 | 727篇 |
1997年 | 489篇 |
1996年 | 354篇 |
1995年 | 321篇 |
1994年 | 272篇 |
1993年 | 243篇 |
1992年 | 1099篇 |
1991年 | 964篇 |
1990年 | 875篇 |
1989年 | 939篇 |
1988年 | 870篇 |
1987年 | 809篇 |
1986年 | 752篇 |
1985年 | 672篇 |
1984年 | 447篇 |
1983年 | 349篇 |
1982年 | 204篇 |
1981年 | 153篇 |
1980年 | 131篇 |
1979年 | 238篇 |
1978年 | 109篇 |
1975年 | 110篇 |
1973年 | 112篇 |
1972年 | 108篇 |
1971年 | 111篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Tetraethylammonium (TEA) effects on K currents were examined on either side of the membrane of hippocampal CA1 neurons by means of whole-cell voltage-clamp recording and intracellular perfusion. Recording media contained ion channel blockers to allow the selective activation of voltage-dependent K currents which consisted of a rapidly decaying component (A-current) and a delayed component. Voltage protocols were applied to separate the A-current from the delayed component. Results show that 10 mM extracellular TEA suppressed 50 +/- 11% (S.D., n = 4) of the delayed current at different levels of depolarization but had little effect on the A-current. In contrast 10 mM TEA applied by intracellular perfusion suppressed the A-current by 42 +/- 10% (S.D., n = 4) in addition to inhibiting the delayed currently 55 +/- 15% (S.D., n = 4). Both the intracellular and extracellular actions of TEA on K currents showed no voltage- nor time-dependency. The results suggest that voltage-dependent transient current (A-current) is mediated through a separate group of ionic channels distinct from those that sustained the delayed current. Furthermore, the asymmetrical effects of intracellular and extracellular TEA on the transient current are similar to those described for the A-current in molluscan neurons. This observation supports the notion that the structure of the ion channel mediating the A-current is closely conserved across different species. 相似文献
92.
93.
94.
M Hettiarachchi E Q Colquhoun J M Ye S Rattigan M G Clark 《International journal of obesity (2005)》1991,15(1):37-43
d,l-Norephedrine (phenylpropanolamine) which is both a demethylated analogue and a metabolite of d,l-ephedrine, is a reputed anorectic agent. In the present study the proposed most active isomer of this mixture, l-norephedrine has been assessed as a peripherally acting thermogenic agent in the isolated perfused rat hindlimb. l-Norephedrine produced a dose-dependent increase in oxygen uptake and perfusion pressure and increased lactate production. Whereas propranolol potentiated the increase in oxygen uptake and perfusion pressure produced by l-norephedrine, prazosin significantly and nitroprusside totally inhibited both of these changes. Nitroprusside also completely inhibited the increase in lactate production. We conclude that norephedrine has a hitherto unrecognized peripheral thermogenic activity in the perfused rat hindlimb resulting from its interaction with alpha 1 adrenergic receptors that control vasoconstriction in this tissue. 相似文献
95.
Through a critical study of herbalogy, it is concluded that the mature seeds of Alpinia zermubet were used as caodoukou in ancient times. The original plant of Yutao recorded in Zhiwu Mingshi Tukao may be the species of Alpinia katsumadai. Baidukou used in ancient times may be the seeds of Alpinia katsumadai found in the south of China, or Amomum compactum and Am. kravanh imported from foreign countries. 相似文献
96.
H S al-Rimawi A A al-Rashied K C Aboo-Backer Q A al-Saleh M F Jallad S Malik 《Annals of tropical paediatrics》1991,11(3):301-303
We report two successful pregnancies in a 17-year-old Arab girl who had received modern combination chemotherapy and central nervous system minimal disease therapy for childhood acute lymphoblastic leukaemia at the age of 9.5 years. 相似文献
97.
S P Brown E R Anderson Q He S Liu Q Wu H Li R Whittle 《The Journal of sports medicine and physical fitness》1992,32(3):288-292
To compare the oxygen cost of submaximal exercise on the Stairobic stepping (SS) machine with bench stepping (BS), 12 healthy men and women (mean age 23 years) underwent six different five minute exercise bouts that were randomly assigned. Tests were conducted using standard open circuit calorimetry. SS at 40 and 60 st/min was equal to BS at 20 st/min and SS at 80 st/min was equal to BS at 30 st/min for VE and RER. VO2 was equal at 20 st/min (BS) and 60 st/min (SS), and 30 st/min (BS) and 80 st/min (SS). Stairobic MET (SM) displayed values over-estimated actual MET (AM) values at the two lowest SS rates and under-estimated the AM value at the highest SS rate. Forty-eight observations of the MET response of SS were conducted and analyzed (BMDP2R) in a forward stepping solution. The multiple regression equation calculated for AM was: AM = -0.567 + -0.012 (WT) + 0.063 (rate) + 0.612 (SM) with an adjusted R2 of 0.82 and a SEE of 0.90. The physiologic cost of BS was approximately equal to SS at two to three times the BS rate of stepping. 相似文献
98.
Clinical evaluation of technetium-99m infecton for the localisation of bacterial infection 总被引:4,自引:3,他引:1
K. E. Britton S. Vinjamuri A. V. Hall K. Solanki Q. H. Siraj J. Bomanji S. Das 《European journal of nuclear medicine and molecular imaging》1997,24(5):553-556
The aim of the study was to distinguish infection from inflammation in patients with suspected infection using technetium-99m Infecton. Ninety-nine patients (102 studies) referred for infection evaluation underwent imaging with 400 MBq99mTc-Infecton at 1 and 4 h. Most patients had appropriate microbiological tests and about half (56) had radiolabelled white cell scans as well. No adverse effects were noted in any patient. The clinical efficacy of99mTc-Infecton depended in part on whether imaging was undertaken during intibiotic therapy for infection or not. In consultation with the microbiologist, 5–14 days of appropriate and successful antibiotic therapy was considered adequate to classify some results as true-negatives. The figures for sensitivity and specificity of99mTc-Infecton for active or unsuccessfully treated infection were 83% and 91% respectively. It is concluded that99mTc-Infecton imaging contributed to the differential diagnosis of inflammation. It is being used as the first imaging modality when bacterial infection is suspected. 相似文献
99.
100.
140 patients with brain tumor were treated by CT-guided stereotactic injections of radionuclides, such as Aurum-198 (198 Au), Phosphorus-32 (32 P) and Yttrium-90 (90Y). Of these patients aged from 3 to 67 years (average 37), 64 were male and 76 female. Astrocytoma was found in 75 patients, craniopharyngioma in 46, metastatic carcinoma in 7, meningioma in 5, germinoma in 4 and pituitary adenoma in 3. The tumors were located in the deep part or functionally critical area of the brain. After 267 times of injection of colloidal isotopes, no major adverse effects or complications occurred. Follow-up for 6 to 48 months showed improvement in symptoms in 104 (74.3%) patients and CT scanning showed the diminished tumors.
相似文献