全文获取类型
收费全文 | 17690篇 |
免费 | 1805篇 |
国内免费 | 376篇 |
专业分类
耳鼻咽喉 | 206篇 |
儿科学 | 368篇 |
妇产科学 | 377篇 |
基础医学 | 2224篇 |
口腔科学 | 315篇 |
临床医学 | 1981篇 |
内科学 | 3352篇 |
皮肤病学 | 295篇 |
神经病学 | 1172篇 |
特种医学 | 605篇 |
外国民族医学 | 2篇 |
外科学 | 2464篇 |
综合类 | 1287篇 |
现状与发展 | 2篇 |
一般理论 | 8篇 |
预防医学 | 1216篇 |
眼科学 | 488篇 |
药学 | 1726篇 |
9篇 | |
中国医学 | 540篇 |
肿瘤学 | 1234篇 |
出版年
2024年 | 34篇 |
2023年 | 208篇 |
2022年 | 460篇 |
2021年 | 677篇 |
2020年 | 499篇 |
2019年 | 529篇 |
2018年 | 609篇 |
2017年 | 513篇 |
2016年 | 471篇 |
2015年 | 613篇 |
2014年 | 801篇 |
2013年 | 943篇 |
2012年 | 1335篇 |
2011年 | 1218篇 |
2010年 | 823篇 |
2009年 | 651篇 |
2008年 | 916篇 |
2007年 | 931篇 |
2006年 | 929篇 |
2005年 | 848篇 |
2004年 | 807篇 |
2003年 | 746篇 |
2002年 | 680篇 |
2001年 | 548篇 |
2000年 | 426篇 |
1999年 | 382篇 |
1998年 | 163篇 |
1997年 | 135篇 |
1996年 | 92篇 |
1995年 | 118篇 |
1994年 | 97篇 |
1993年 | 61篇 |
1992年 | 174篇 |
1991年 | 236篇 |
1990年 | 150篇 |
1989年 | 112篇 |
1988年 | 110篇 |
1987年 | 102篇 |
1986年 | 82篇 |
1985年 | 70篇 |
1984年 | 57篇 |
1983年 | 44篇 |
1982年 | 34篇 |
1980年 | 40篇 |
1979年 | 49篇 |
1978年 | 35篇 |
1977年 | 26篇 |
1975年 | 31篇 |
1974年 | 30篇 |
1973年 | 41篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
1 240例女性生殖道支原体感染分析 总被引:23,自引:5,他引:18
目的 为了解生殖道支原体在晚期孕妇、育龄妇女、念珠菌性阴道炎和淋球菌性阴道炎患者中的感染状况。方法 采用套式聚合酶链反应技术,对962例晚期孕妇、85例育龄妇女、90例念珠菌性阴道炎和103例淋球菌性阴道炎患者的宫颈拭子标本进行了生殖道支原体检测。结果 在晚期孕妇、育龄妇女、念珠菌性阴道炎和淋球菌性阴道炎患者中生殖道支原体的检出率分别为4.16%、3.52%、11.1l%和13.59%。结论 生殖道支原体在晚期孕妇、育龄妇女、念珠菌性阴道炎和淋球菌性阴道炎妇女中均有一定的检出率。 相似文献
63.
我国登革2型病毒43株包膜E蛋白基因的特征 总被引:2,自引:0,他引:2
对我国1987年流行的登革2型病毒43株包膜E蛋白基因的核苷酸序列进行了分析。结果表明登革2型病毒43株包膜E蛋白基因核苷酸序列含1485个核苷酸,编码495个氨基酸,并就其核苷酸序列及其相应的氨基酸序列与其它的登革2型病毒株进行了比较,发现核苷酸序列与我国1985年分离的登革2型病毒04株,新几内亚C株(NGC),牙买加株1409(JAM)和马来西亚当地流行株M1(登革出血热)、血2(登革休克综合征)、M3(登革热)同源性分别是95.8%、94.6%、97.5%、925%、92.7%和939%,氨基酸序列的同源性分别是94.3%、94.3%、96.0%、93.7%、93.7%和91.5%,推断出的氨基酸序列显示出12个保守的半胱氨酸残基和两个潜在的糖基化位点,分别位于Asn-67和Asn-153位。 相似文献
64.
Effect of Cu2+ on relaxations to the nitrergic neurotransmitter, NO and S-nitrosothiols in the rat gastric fundus.
下载免费PDF全文
![点击此处可从《British journal of pharmacology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J. G. De Man B. Y. De Winter G. E. Boeckxstaens A. G. Herman P. A. Pelckmans 《British journal of pharmacology》1996,119(5):990-996
1. The effects of addition of Cu2+ and chelation of Cu2+ were studied on relaxations in response to S-nitrosothiols and on relaxations to non-adrenergic non-cholinergic (NANC) nerve stimulation, nitric oxide (NO) and glyceryl trinitrate (GTN) in the rat gastric fundus. 2. The S-nitrosothiols S-nitroso-L-cysteine (NOCys, 1-300 nM), S-nitrosoglutathione (GSNO, 0.01-3 microM) and S-nitroso-N-acetyl-D,L-penicillamine (SNAP, 0.01-3 microM) induced concentration-dependent relaxations of the rat gastric fundus muscle strip. The relaxant potencies of the S-nitrosothiols were NOCys > SNAP > GSNO. Relaxations to NOCys were transient and comparable to those to NANC nerve stimulation and NO whereas relaxations to GSNO and SNAP were sustained. The relaxations to NOCys, GSNO and SNAP were significantly and concentration-dependently enhanced by CuSO4 (3-30 microM). The order of relaxant potency in the presence of CuSO4 was reversed to GSNO approximately SNAP > NOCys. 3. In the presence but not in the absence of 0.1 microM GSNO, CuSO4 (1 microM) induced a rapid and transient relaxation which was inhibited by the superoxide radical generator, pyrogallol (30 microM). CuCl2 but not FeSO4 mimicked the effect of CuSO4. 4. Electrical stimulation (0.5-8 Hz) of the rat gastric fundus strips induced frequency-dependent relaxations which were previously shown to be nitrergic in nature and which were not affected by CuSO4 (3-30 microM). Relaxations to NO (3-100 nM) and GTN (0.01-1 microM) were not affected by 3 and 10 microM CuSO4 but were inhibited by 30 microM CuSO4. 5. The Cu2+ chelator, bathocuproine (3-30 microM) significantly and concentration-dependently inhibited the relaxations to NOCys (0.01-3 microM), GSNO (0.01-10 microM) and SNAP (0.01-3 microM). The inhibitory effect of 10 microM bathocuproine was reversed by 3 microM CuSO4. 6. Bathocuproine (3-30 microM) had no effect on the relaxations to NANC nerve stimulation (0.5-8 Hz) or on the concentration-response curve to NO (0.01-0.3 microM), whereas relaxations to GTN (0.01-1 microM) were significantly inhibited by 30 microM bathocuproine. 7. From these results we conclude that relaxations to S-nitrosothiols and to nitrergic stimulation of the rat gastric fundus are differentially affected by addition and chelation of Cu2+, suggesting that the nitrergic NANC neurotransmitter in the rat gastric fundus is not an S-nitrosothiol but is more likely to be free nitric oxide. 相似文献
65.
66.
John Hill Robert C. Stuart Hin K. Fung Enders K.W. Ng Fanny M. Cheung Sidney C.S. Chung C. Andrew van Hasselt 《The Laryngoscope》1997,107(10):1373-1377
The aim of this study was to investigate the origin of globus pharyngis with particular reference to esophageal disorders such as gastroesophageal reflux disease (GERD), motility disorders, structural abnormalities, other gastrointestinal tract diseases, and psychological profile. Previous studies on this subject using 24-hour pH monitoring give conflicting results and are hampered by the high background prevalence of asymptomatic GERD in the normal Western population. The local Chinese population is known to have a very low background level of GERD and therefore is an ideal study population. Twenty-six patients with globus pharyngis underwent 24-hour ambulatory pH monitoring, esophageal manometry, and esophagogas-troduodenoscopy with lower esophageal biopsy. A control group of 20 patients presenting with non-ulcer dyspepsia was similarly investigated. Personality profiles of the globus pharyngis subjects and an appropriate control group were assessed. Eight of the globus pharyngis group (30.7%) had evidence of GERD, whereas only one of the controls (5%) demonstrated GERD on 24-hour esophageal pH monitoring (P < 0.05). The manometric and personality profile studies did not show significant differences between study and control groups. We concluded that the finding of GERD in patients with globus pharyngis is not a coincidental finding but that there is a true association between GERD and globus pharyngis. 相似文献
67.
多巴酚丁胺负荷及运动试验~(99m)Tc-MIBI心肌断层显像与冠状动脉造影的对比研究 总被引:2,自引:0,他引:2
比较69例冠心病患者多巴酚丁胺负荷99mTc甲氧基异丁基异腈(MIBI)心肌断层显像与82例运动试验99mTcMIBI心肌断层显像的结果,以探讨它们对冠心病的诊断价值。结果表明:以冠状动脉造影结果为标准,多巴酚丁胺负荷诊断冠心病的敏感性和特异性分别为912%和800%,运动试验分别为894%和829%。多巴酚丁胺负荷检出冠状动脉病变的敏感性和特异性:左前降支为781%和913%,回旋支为667%和982%,右冠状动脉为100%和837%;运动试验分别为783%和911%,600%和968%,909%和850%,差异均无显著性(P>005)。提示两者结果相近,对于不能进行运动试验的病人,多巴酚丁胺试验是一种有价值的诊断冠心病的方法。 相似文献
68.
Effects of 1-week head-down tilt bed rest on bone formation and the calcium endocrine system. 总被引:6,自引:0,他引:6
S B Arnaud D J Sherrard N Maloney R T Whalen P Fung 《Aviation, space, and environmental medicine》1992,63(1):14-20
To understand the potential early responses of human bone and the calcium endocrine system to spaceflight, we studied 8 healthy men, aged 35-44 years before, during, and after bed rest in a -6 degrees head-down tilt model for microgravity. Based on a novel single-dose labeling schedule, average rates of bone formation in the iliac crest were reduced in 6, unchanged in 1, and increased in 1 following the bed rest period. The decrease was greatest for subjects whose daily walking miles were highest (r = -0.762, p less than 0.05, n = 7). Before a measurable increase in ionized serum calcium the sixth bed rest day, there was increased excretion of urinary calcium and sodium, evident the first 2 bed-rest days and parallel for the entire week (r = 0.92, p less than 0.001). Reduced excretion of phosphorus and 3', 5' cyclic adenosine monophosphate on the first and second bed rest days was followed by an increase in serum phosphorus by the sixth bed rest day. Depressed serum concentrations of parathyroid hormone and 1,25-dihydroxyvitamin D were manifest by the sixth and seventh bed rest days. The similarity of the response of bone and the calcium endocrine system of healthy men after only 7 days to results of longer term bed rest studies emphasizes the responsiveness of the adult human skeleton to biomechanical stimuli induced by changes in activity and/or position. 相似文献
69.
70.
The incidence, timing, and management of biliary tract complications after orthotopic liver transplantation. 总被引:29,自引:1,他引:28
下载免费PDF全文
![点击此处可从《Annals of surgery》网站下载免费的PDF全文](/ch/ext_images/free.gif)
F Greif O L Bronsther D H Van Thiel A Casavilla S Iwatsuki A Tzakis S Todo J J Fung T E Starzl 《Annals of surgery》1994,219(1):40-45
OBJECTIVE: This study analyzed the incidence and timing of biliary tract complications after orthotopic liver transplantation (OLTx) in 1792 consecutive patients. These results were then compared with those of previously reported series. Finally, recommendations were made on appropriate management strategies. SUMMARY BACKGROUND DATA: Technical complications after OLTx have a significant impact on patient and graft survival. One of the principal technical advances has been the standardization of techniques for biliary reconstruction. Nonetheless, biliary complications still occur. A 1983 report from the University of Pittsburgh reported biliary complications in 19% of all transplants, and an update in 1987 reported biliary complications in 13.2% of transplants. METHODS: The medical records of all patients who underwent liver transplantation and were hospitalized between January 1, 1988 and July 31, 1991 were reviewed. The case material consisted of the medical records of 217 patients treated for 245 biliary complications. RESULTS: Primary biliary continuity was established by either choledochocholedochostomy over a T-tube (C-C, n = 129) or a Roux-en-Y choledochojejunostomy with an internal stent (C-RY, n = 85). The overall incidence for biliary complication in this large series was 11.5%. Strictures (n = 93) and bile leak (n = 58) were the most common complications (69.6%). Most biliary complications (n = 143, 66%) occurred within the first 3 months after surgery. In general, leaks occurred early, and strictures developed later. Bile leaks were equally frequent in both C-C and C-RY (27.1% and 25.9%, respectively); strictures were more common after a C-RY type of reconstruction (36.4% and 52.9%, respectively). Twenty-one patients died, an incidence of 9.6%. Fifteen of the 21 biliary-related deaths were among patients treated for rejection before the recognition of biliary tract pathologic findings. CONCLUSIONS: Progress has been made on improving the results of biliary reconstruction after OLTx. Nonetheless, patients continue to experience biliary complications after OLTx, and these complications cause considerable loss of grafts and life. If significant additional improvement in patient and graft survival are to be obtained, the technical performance of OLTx must continue to improve. 相似文献