全文获取类型
收费全文 | 16636篇 |
免费 | 1370篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 147篇 |
儿科学 | 542篇 |
妇产科学 | 321篇 |
基础医学 | 2312篇 |
口腔科学 | 270篇 |
临床医学 | 1621篇 |
内科学 | 3627篇 |
皮肤病学 | 175篇 |
神经病学 | 1343篇 |
特种医学 | 664篇 |
外科学 | 2829篇 |
综合类 | 271篇 |
一般理论 | 20篇 |
预防医学 | 1453篇 |
眼科学 | 400篇 |
药学 | 1025篇 |
1篇 | |
中国医学 | 14篇 |
肿瘤学 | 1015篇 |
出版年
2023年 | 72篇 |
2022年 | 112篇 |
2021年 | 309篇 |
2020年 | 204篇 |
2019年 | 321篇 |
2018年 | 432篇 |
2017年 | 289篇 |
2016年 | 304篇 |
2015年 | 349篇 |
2014年 | 515篇 |
2013年 | 692篇 |
2012年 | 1184篇 |
2011年 | 1150篇 |
2010年 | 649篇 |
2009年 | 570篇 |
2008年 | 1005篇 |
2007年 | 1072篇 |
2006年 | 1073篇 |
2005年 | 1024篇 |
2004年 | 1004篇 |
2003年 | 938篇 |
2002年 | 895篇 |
2001年 | 194篇 |
2000年 | 189篇 |
1999年 | 194篇 |
1998年 | 189篇 |
1997年 | 188篇 |
1996年 | 161篇 |
1995年 | 128篇 |
1994年 | 127篇 |
1993年 | 136篇 |
1992年 | 109篇 |
1991年 | 141篇 |
1990年 | 90篇 |
1989年 | 108篇 |
1988年 | 107篇 |
1987年 | 97篇 |
1986年 | 113篇 |
1985年 | 86篇 |
1984年 | 98篇 |
1983年 | 112篇 |
1982年 | 104篇 |
1981年 | 107篇 |
1980年 | 94篇 |
1979年 | 112篇 |
1978年 | 88篇 |
1977年 | 69篇 |
1976年 | 60篇 |
1975年 | 77篇 |
1974年 | 64篇 |
排序方式: 共有10000条查询结果,搜索用时 781 毫秒
31.
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
32.
1-Deamino-8 D-arginine vasopressin (DDAVP) has been used effectively to normalize the bleeding time in various hemostatic disorders. In von Willebrand disease the reduction in bleeding time is due to the preferential release of large multimers of von Willebrand factor from endothelial cells. However, since the bleeding time correction in patients with uremia and liver disease is independent of the release of von Willebrand antigen and activity, other mechanisms of action of DDAVP need to be considered. Endothelial cells generate several thromborepellant factors including 13-hydroxyoctadecadienoic acid (13-HODE), an inhibitor of platelet adhesion to subendothelium. Using cultured fetal bovine aortic endothelial cells (FBAECs), we have investigated whether DDAVP modulates the production of 13-HODE. We have demonstrated that 14C-linoleic acid labeled FBAECs release several oxygenated derivatives of linoleic acid following a 120 min incubation in the presence of serum. One of these products was identified by chromatographic procedures as 13-HODE. The production of 13-HODE was decreased significantly by DDAVP (1-100 ng/ml) with maximal reduction (approx. 25%) seen at 1 ng/ml of DDAVP. While vehicle treated control FBAECs generated 6780 +/- 690 cpm of 13-HODE per 10(6) cells (mean +/- SE, n = 8), DDAVP treated FBAECs produced 4950 +/- 310 (P < 0.01), 5390 +/- 390 (P < 0.01), and 5720 +/- 410 cpm (P < 0.05) of 13-HODE at 1, 10, and 100 ng/ml DDAVP respectively. Our findings of a decrease in 13-HODE would explain the previously observed morphologic changes of increased platelet adhesion to subendothelium following DDAVP infusion and contributes to our understanding of the mode of action of this therapeutic agent in hemostatic disorders. 相似文献
33.
34.
Stuart M. Lichtman Abraham Mittelman Daniel R. Budman Carmelo A. Puccio Hoo G. Chun Steven L. Allen Tauseef Ahmed Zalmen A. Arlin 《Leukemia & lymphoma》1991,6(1):61-63
A phase II trial of fludarabine phosphate using a bolus and continuous infusion regimen in previously treated multiple myeloma was performed. No responses were observed in eleven patients. There was no significant non-hematologic toxicity noted. Fludarabine phosphate is inactive in multiple myeloma using this schedule. 相似文献
35.
Dr Robert M. Lynd-Stevenson Stuart Byrne Sue Dolman Michael Harrison Brian Williams 《Clinical Psychologist》2007,11(2):45-49
The present paper outlines the development and evaluation of an allocation committee to distribute community placements on an equitable basis between universities. Although based on our experience in South Australia with the University Placement Allocation Committee (UPAC), the primary goal is to outline the steps that would be useful if placement coordinators at other universities in Australia decided to establish and maintain an allocation committee. A survey of field supervisors was also conducted and field supervisors endorsed UPAC as a constructive mechanism for allocating community placements. 相似文献
36.
Galega officinalis L (goatsrue), a plant introduced from Europe and found in abundance in northern Utah, was tested for toxicity in ewes (Ovis aries). Clinical signs of poisoning induced by doses as small as 0.8 g of dried plant/kg body weight/day included dyspnea, anoxia, and foaming nasal discharge. Pathologic signs in animals that died following overdose of the plant included severe hydrothorax, generalized lung congestion, foamy exudate in bronchioles and trachea, epicardial and endocardial petechiation, and pericardial effusion in severely affected ewes. Microscopic lesions included a severe diffuse alveolar and interlobular edema. No significant alterations in blood constituents were observed in treated animals. Ewes administered the plant on several consecutive days developed an apparent adaptation to the toxin of the plant and were thereby able subsequently to tolerate levels 5-10 times the pre-treatment lethal dose with no discernible adverse clinical or pathological effects. 相似文献
37.
Stuart J. McLachlan John C. Francisco Joseph R. Pernicone Anton N. Hasso 《Journal of magnetic resonance imaging : JMRI》1994,4(3):405-411
A phase III multicenter study was conducted in 89 patients with known intracranial vascular lesions to evaluate an extracellular gadolinium contrast agent, gadoteridol, for intracranial magnetic resonance (MR) angiography. The pre- and postcontrast MR angiograms of 82 patients were evaluated by the unblinded investigators and by two blinded readers (A and B) for visualization of lesions; arterial and venous anatomy; extent, size, and number of lesions; and disease classification. The unblinded readers indicated that lesions were visualized better on postcontrast images in the following categories: venous anatomy, 87 (81%) of 107 lesions; arterial anatomy, 43 lesions (40%); and extent or size of lesions, 38 lesions (36%). In 29 (35%) of 82 patients, the unblinded readers determined that enhanced MR angiography provided more diagnostic information than unenhanced MR angiography. The blinded readers determined that enhanced MR angiography provided more information for visualization of vascular anatomy in more than 60% of cases. The additional information provided with gadoteridol would have changed the diagnosis in nine (8%) of 107 lesions seen by the unblinded readers, 11 (12%) of 90 lesions seen by reader A, and three (3%) of 93 lesions seen by reader B. The results confirm that the use of gadoteridol improves the visualization of intracranial vascular lesions with MR angiography. The authors conclude that development of new postprocessing algorithms will improve the utility of contrast-enhanced MR angiography. 相似文献
38.
39.
Nigel Wynne RGN/Dip BSc Stuart Brand BSc PhD Roy Smith BA PhD 《Journal of advanced nursing》1997,26(3):470-474
There is an ongoing debate in nurse education concerning the role and delivery of the biological sciences in the nursing curriculum. One of the fundamental questions raised by this debate asks how best can teachers impart biological knowledge in a manner that can be readily applied by students and qualified nurses to inform their clinical practice. This paper will include a discussion of some of the features of pre-registration education that may have influenced the manner in which biological sciences are perceived, taught and used by nurses. It will be argued that nursing may have developed a form of incomplete holism and that this may be in part responsible for the challenges that remain to be met within this area of the nursing curriculum. As a response to incomplete holism an innovative approach within pre-registration education will be introduced. This development involves the use of linked teaching sessions which aim to develop the analytical skills necessary to apply physiological knowledge to nursing practice. 相似文献
40.