全文获取类型
收费全文 | 22845篇 |
免费 | 2071篇 |
国内免费 | 66篇 |
专业分类
耳鼻咽喉 | 246篇 |
儿科学 | 742篇 |
妇产科学 | 518篇 |
基础医学 | 3128篇 |
口腔科学 | 377篇 |
临床医学 | 2546篇 |
内科学 | 4776篇 |
皮肤病学 | 221篇 |
神经病学 | 1920篇 |
特种医学 | 945篇 |
外科学 | 3631篇 |
综合类 | 394篇 |
一般理论 | 25篇 |
预防医学 | 2111篇 |
眼科学 | 492篇 |
药学 | 1553篇 |
1篇 | |
中国医学 | 20篇 |
肿瘤学 | 1336篇 |
出版年
2022年 | 135篇 |
2021年 | 401篇 |
2020年 | 265篇 |
2019年 | 408篇 |
2018年 | 518篇 |
2017年 | 364篇 |
2016年 | 387篇 |
2015年 | 451篇 |
2014年 | 658篇 |
2013年 | 875篇 |
2012年 | 1456篇 |
2011年 | 1459篇 |
2010年 | 809篇 |
2009年 | 702篇 |
2008年 | 1276篇 |
2007年 | 1338篇 |
2006年 | 1355篇 |
2005年 | 1318篇 |
2004年 | 1270篇 |
2003年 | 1184篇 |
2002年 | 1154篇 |
2001年 | 453篇 |
2000年 | 445篇 |
1999年 | 394篇 |
1998年 | 269篇 |
1997年 | 260篇 |
1996年 | 228篇 |
1995年 | 186篇 |
1994年 | 180篇 |
1993年 | 198篇 |
1992年 | 285篇 |
1991年 | 282篇 |
1990年 | 252篇 |
1989年 | 248篇 |
1988年 | 233篇 |
1987年 | 216篇 |
1986年 | 219篇 |
1985年 | 197篇 |
1984年 | 173篇 |
1983年 | 181篇 |
1982年 | 139篇 |
1981年 | 160篇 |
1980年 | 127篇 |
1979年 | 183篇 |
1978年 | 152篇 |
1977年 | 116篇 |
1975年 | 117篇 |
1974年 | 116篇 |
1973年 | 135篇 |
1972年 | 117篇 |
排序方式: 共有10000条查询结果,搜索用时 209 毫秒
41.
Objective. Neurally augmented sexual function (NASF) is the production of pleasurable genital stimulation and subsequent orgasm through the application of electrical energy to provide stimulation of the spinal cord or peripheral nerves. The purpose of this paper is to demonstrate the reproducibility of this phenomenon. Materials and Methods. Eleven otherwise healthy women, ages 32–60 years, were selected for this study. Through standard techniques, quadripolar (octopolar in the final patient) leads were placed in the epidural space percutaneuously. The lead was maneuvered initially to an L1–L2 position and then repositioned based on feedback from the patient. The patients were allowed to utilize the device ad libitum for up to 9 days. Results. Successful stimulation was achieved in 91% (10/11) of patients. These women described a greater frequency in sexual activity, increased lubrication, and overall satisfaction. A smaller subset had substantial improvement in sexual function as measured by orgasmic capacity. This subset consisted of women with secondary anorgasmia. A return of orgasmic capacity was found in 80% (4/5) of patients having secondary anorgasmia with an average intensity of ≥ 3/5 while using the device. Once the device was removed, the patients returned to their previous anorgasmic status. Conclusions. Pleasurable genital stimulation of the spinal cord is a consistently reproducible phenomenon. In a subset of the population studied, improvement in orgasmic function was noted. This was noted in the group with secondary orgasmic dysfunction. 相似文献
42.
A portable ultrasound unit with a 3.5-MHz probe allows accurate imaging of both cerebral hemispheres and partial imaging of the posterior fossa through unilateral exploratory burr holes or a craniotomy. In patients with clinical signs of transtentorial herniation after severe head injury, this unilateral technique can detect extraaxial and intraparenchymal mass lesions more accurately than is possible with bilateral exploratory burr holes. 相似文献
43.
Examination of potential mechanism(s) of metallothionein induction by diethyl maleate. 总被引:1,自引:0,他引:1
J W Bauman Y P Liu G K Andrews C D Klaassen 《Toxicology and applied pharmacology》1992,117(2):226-232
Diethyl maleate (DEM) is a glutathione-depleting agent that can increase the levels of the sulfhydryl-rich protein metallothionein (MT) in liver. The purpose of the present study was to examine the mechanism(s) by which DEM increases mouse hepatic MT levels. DEM appears to be an indirect MT inducer as suggested by the lack of increase in MT levels when cultured mouse hepatocytes were exposed to DEM. Four possible mechanisms by which indirect MT inducers may cause an elevation in MT concentrations in liver were examined. Zn levels did not increase prior to the increase in hepatic MT, thus, a Zn redistribution to the liver is not the cause of the liver MT induction by DEM. The adrenal gland products were not required for MT induction in liver, as adrenalectomy did not abolish the increase in hepatic MT caused by DEM. The elevation in liver MT does not appear to be due solely to the decrease in liver glutathione (60%) in the initial hour after DEM, because phorone, which decreases liver glutathione (80%), produced only a fourfold increase in hepatic MT. Activation of macrophages does not seem to account for the rise in liver MT levels, as there was no increase in abundance of cytokine mRNAs for TNF-alpha, IL-1 beta, or IL-6 in the liver. These data suggest that the induction of hepatic MT by DEM does not occur in response to (1) an increase in liver Zn that precedes the increase in liver MT, (2) release of adrenal gland products, (3) decrease in liver glutathione, or (4) increased cytokine gene expression. 相似文献
44.
45.
Stuart A. Batterman Alfred Franzblau Nanzheng Zhou 《International archives of occupational and environmental health》1996,68(4):268-274
Dermal exposures of methanol were administered in a clinical study designed to compare several biological indicators. Four
subjects were exposed in five exposure sessions of varying length. In each session, a sequence of measurements of methanol
concentrations in blood, breath, and headspace samples of air at exposed and unexposed skin were collected before and after
dermal exposures. Skin headspace samples, collected in gas sampling bags, were designed to reflect equilibrium skin: air partitioning.
At exposed skin, headspace samples were highly elevated for at least 8 h following exposure, indicating the presence of a
methanol reservoir in skin. After exposure, methanol concentrations at exposed skin showed a rapid initial decline, then a
slower first-order decrease. Methanol concentrations were clearly detectable in headspace samples at unexposed skin. Substantial
transfer from exposed skin occurred due to mechanical contact and washing. When transfer was restricted, surface concentrations
at unexposed skin were similar to levels in breath and were strongly correlated to methanol concentrations in blood. While
results are preliminary due to the small sample sizes and several unresolved experimental issues, the simple, rapid, and noninvasive
skin headspace measurements appear useful as a biological exposure indicator that clearly shows the presence and site of a
dermal exposure, and measurements at unexposed skin reflect concentrations in blood.
Received: 14 March 1995/Accepted: 3 November 1995 相似文献
46.
Richard Tello Reginald F. Munden Stuart Hooton Kris Kandarpa Robert PugatchAuthor vitae 《Computerized medical imaging and graphics》1998,22(6):267-452
Introduction: Features of spiral CT (SCT) — fast scanning, dynamic injection of contrast allowing optimal vessel opacification, and supplemental multiplanar imaging — promises to provide increased accuracy in the diagnosis of acute and non acute thoracic vascular disease. Recent work demonstrating the cost effective triage of hemodynamically stable patients after blunt chest trauma for angiography based on dynamic CT findings has prompted an investigation into the accuracy of SCT in this clinical setting. Methods: A retrospective review of all patients seen in the emergency department over the period of one year for aortic, thoracic, or blunt chest trauma evaluation was performed (74 patients) and all SCT scans available were reviewed and data reformatted for optimal delineation of pathology using maximum intensity projection and multiplanar reformation. The accuracy and predictive positive and negative values of SCT were calculated with respect to angiography, surgical, and/or clinical follow up evaluation. Results: Twenty three (31%) patients went directly to angiography owing to mediastinal widening on chest film and hemodynamic instability, of which four were positive and required emergent surgery. Seven hemodynamically stable patients (9%) had noncontrast SCT owing to mediastinal widening on chest film, all of which had angiography with none having great vessel trauma. Fourty four hemodynamically stable patients (60%) had contrast enhanced SCT (ceSCT), of which five (11%) were abnormal and underwent angiography, four of these were positive for aortic damage, one for a subclavian artery laceration. Of the remaining 39 patients who had normal ceSCT; five had angiography, all of which were normal. Of the remaining 34 patients that had normal ceSCT none had adverse outcome on clinical follow-up, minimum of 12 months. Conclusion: The predictive positive value for aortic trauma of ceSCT in blunt trauma is 80%, with a predictive negative value of 100%, indicating that it is feasible for SCT to be a first line exam in blunt chest trauma in the future. 相似文献
47.
48.
49.
Stuart Gherini Andre Lopez Lysiane Juberthie Jean Clatude Olivier 《Indian journal of otolaryngology and head and neck surgery》1994,46(2):50-62
The aim of surgical treatment of a fixed stapes is to restore an as effective as possible impedance transfer of the ossicular chain and acoustic impedance of the annular ligament of the footplate, when it has lost elasticity, and this in order to achieve the best possible physiological vibration of the inner ear fluids. 相似文献
50.
The fate of gallstones spilled during laparoscopic cholecystostomy has been thought to be relatively benign. Recent experience and a review of the recent literature shows that this is not always the case. We report three cases of complications of retained stones and analyse the literature with regard to types of complications, time to presentation, and recommendations for managing spilled gallstones. Retained gallstones have been shown to cause adhesions in the rat and inflammatory reactions in dogs with no evidence of absorption. The average time to presentation of complications arising from retained gallstones is 27.3 weeks. Complications include: Intraabdominal abscess formation with or without abdominal wall sinus tract formation, persisting abdominal wall sinus tracts from port site abscess, subhepatic inflammatory masses, cholelithoptysis, microabscesses and granuloma formation, liver abscess and “dumbell” shaped abscess with one side of the “dumbell” forming a subcutaneous abscess. We recommend the judicious use of retrieval devices during the extraction phase of the laparoscopic cholecystectomy, diligent removal of any spilled stones and awareness of delayed postoperative pain and tenderness as a harbinger of symptomatic retained gallstones. Documentation of intraoperative gallstone spillage, volume, type of gallstones, and effort to retrieve is recommended. 相似文献