全文获取类型
收费全文 | 9037篇 |
免费 | 875篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 237篇 |
妇产科学 | 170篇 |
基础医学 | 1385篇 |
口腔科学 | 189篇 |
临床医学 | 960篇 |
内科学 | 2094篇 |
皮肤病学 | 123篇 |
神经病学 | 745篇 |
特种医学 | 317篇 |
外科学 | 1246篇 |
综合类 | 218篇 |
一般理论 | 7篇 |
预防医学 | 877篇 |
眼科学 | 95篇 |
药学 | 668篇 |
中国医学 | 4篇 |
肿瘤学 | 532篇 |
出版年
2021年 | 130篇 |
2019年 | 110篇 |
2018年 | 120篇 |
2016年 | 84篇 |
2015年 | 124篇 |
2014年 | 165篇 |
2013年 | 230篇 |
2012年 | 334篇 |
2011年 | 398篇 |
2010年 | 210篇 |
2009年 | 213篇 |
2008年 | 326篇 |
2007年 | 314篇 |
2006年 | 344篇 |
2005年 | 348篇 |
2004年 | 317篇 |
2003年 | 303篇 |
2002年 | 274篇 |
2001年 | 312篇 |
2000年 | 289篇 |
1999年 | 272篇 |
1998年 | 180篇 |
1997年 | 117篇 |
1996年 | 141篇 |
1995年 | 97篇 |
1994年 | 104篇 |
1993年 | 99篇 |
1992年 | 234篇 |
1991年 | 225篇 |
1990年 | 217篇 |
1989年 | 193篇 |
1988年 | 208篇 |
1987年 | 187篇 |
1986年 | 210篇 |
1985年 | 197篇 |
1984年 | 144篇 |
1983年 | 155篇 |
1982年 | 103篇 |
1981年 | 102篇 |
1980年 | 79篇 |
1979年 | 144篇 |
1978年 | 135篇 |
1977年 | 109篇 |
1976年 | 113篇 |
1975年 | 103篇 |
1974年 | 118篇 |
1973年 | 107篇 |
1970年 | 79篇 |
1969年 | 74篇 |
1968年 | 73篇 |
排序方式: 共有9944条查询结果,搜索用时 15 毫秒
11.
12.
A Decade of Change in Obesity Surgery 总被引:4,自引:0,他引:4
Edward E Mason MD PhD Shenghui Tang MS Kathleen E Renquist BS Dwight T Barnes Joseph J Cullen MD Cornelius Doherty MD James W Maher MD 《Obesity surgery》1997,7(3):189-197
Background: The International (formerly National) Bariatric Surgery Registry began collecting data in January 1986. The aim
of this study was to examine changes in the practice of surgical treatment of severe obesity that occurred during the decade
of 1986 through 1995, as observed in the IBSR data. Methods: All data submitted to the IBSR during the decade were transferred
to the IBM mainframe computer for analysis. Characteristics of operative type populations were compared over time using analysis
of variance (ANOVA) for age, body mass index (BMI), operative weight and Chi-square (χ2) test for gender. Results: There has been a steady increase over the decade in mean patient weight. The operations used have
changed from predominantly ‘simple’ operations to more frequent use of ‘complex’ operations. Within the categories of ‘simple’
and ‘complex’, an increase in the variety of operations occurred. As a group, patients with ‘simple’ operations have been
heavier, more often male and public pay patients than those who have undergone ‘complex’ operations. One year weight loss
was greater for Roux-en-Y gastric bypass (RGB) than vertical banded gastroplasty (VBG), but follow-up rates were too low to
study the relative merits of the operations used. The reported incidence of operative mortality and serious complications
(leak with peritonitis, abscess and pulmonary embolism) remained low. Conclusions: These observations and their implications
can be summarized in three statements which relate to action for improved patient care in the beginning of the new century:
(1) increasing weight of candidates for surgical treatment during this decade indicates the need for earlier use of operative
treatment before irreversible complications of obesity can develop; (2) low risk of obesity surgery, decreasing postoperative
hospital stay, and early weight control support the continued and increased use of surgical treatment; (3) continued widespread
use of both ‘simple’ and ‘complex’ operations with increased modifications of standard RGB and VBG procedures emphasizes the
need for standardized long-term data and analyses regarding both weight control and postoperative side-effects. 相似文献
13.
Drawing upon preliminary research findings, this paper considers whether pharmacists in Britain face a crisis in their occupational status and identity as a result of changes in their work and market situations. It further examines some of the ways in which they are responding to the challenges and opportunities presented. The paper also comments on the utility of the concepts of 'reprofessionalization' and 'occupational imperialism' in the study of British pharmacy. 相似文献
14.
15.
A McRae S Hjorth D W Mason L Dillon T R Tice 《Journal of neural transplantation & plasticity》1991,2(3-4):165-173
Biodegradable controlled-release microsphere systems made with the biocompatible biodegradable polyester excipient poly [DL lactide-co-glycolide] constitute an exciting new technology for drug delivery to the central nervous system (CNS). The present study describes functional observations indicating that implantation of dopamine (DA) microspheres encapsulated within two different polymer excipients into denervated-striatal tissue assures a prolonged release of the transmitter in vivo. Moreover, in this regard, the results show that there were clear cut temporal differences in the effect of the two DA microsphere formulations compared in this study, probably reflecting variations in the actual composition (i.e., lactide to glycolide ratio) of the two copolymer excipients examined. This technology has considerable potential for basic research with possible clinical application. 相似文献
16.
A study of intravenous (i.v.) cannula usage for medical emergencies admitted to hospitals in the Newham Health District was undertaken during two defined periods (24 and 35 days). Almost half the cannulas inserted (47%) were not flushed following an initial bolus injection of heparinized saline. The duration that cannulas remained in a vein ranged from 24 hours to 8 days (median 2 days) and inflammation around the cannula site was related to the length of time since insertion but unrelated to whether the cannula was flushed regularly or to the type of fluid used. Our findings indicate a substantial wastage of i.v. cannulas due to difficulties with insertion and suggest that isotonic saline, without heparin, is effective in maintaining cannula patency for 48 hours. It is concluded that these findings are not unique to the Newham Health District and worthwhile financial savings should be achieved throughout the NHS if clinicians reconsider the indications and use of i.v. cannulas for their patients. 相似文献
17.
Background
Traumatic perforation of the distal oesophagus due to blunt trauma is a very rare condition and is still associated with a significant morbidity and mortality. This is further exacerbated by delayed diagnosis and management as symptoms and signs are often masked by or ascribed to more common blunt thoracic injuries. 相似文献18.
Use of the deoxyuridine suppression test to evaluate localized folate deficiency in rat colonic epithelium 总被引:1,自引:0,他引:1
M L Cravo J B Mason J Selhub I H Rosenberg 《The American journal of clinical nutrition》1991,53(6):1450-1454
In this study the deoxyuridine suppression test (dUST) was performed on isolated rat colonocytes to establish its value as an indicator of folate status in the colonic epithelium. [3H]thymidine incorporation into DNA was suppressed greater than 90% by deoxyuridine (dU) concentrations greater than 2.5 mumol/L. Preincubation of cells with 5-fluorouracil (1-100 mumol/L) but not methotrexate (10-100 mumol/L) resulted in a significant decrease in the degree of suppression. The dUST performed on colonocytes from folate-deficient animals displayed less suppression than on colonocytes from folate-replete animals (P less than 0.05). The abnormal degree of suppression was corrected by adding 100 mumol folinic acid/L. There was a negative correlation between the degree of suppression and the folate concentration of the colonic epithelium (P less than 0.001). These data indicate that the dUST is useful for detecting folate deficiency in the colonic epithelium and may therefore be valuable in assessing a deficiency state localized to that epithelium. 相似文献
19.
20.