全文获取类型
收费全文 | 55535篇 |
免费 | 2066篇 |
国内免费 | 788篇 |
专业分类
耳鼻咽喉 | 882篇 |
儿科学 | 857篇 |
妇产科学 | 325篇 |
基础医学 | 4233篇 |
口腔科学 | 531篇 |
临床医学 | 6254篇 |
内科学 | 10439篇 |
皮肤病学 | 533篇 |
神经病学 | 2188篇 |
特种医学 | 1491篇 |
外科学 | 7090篇 |
综合类 | 8810篇 |
现状与发展 | 1篇 |
一般理论 | 2篇 |
预防医学 | 3454篇 |
眼科学 | 212篇 |
药学 | 4770篇 |
331篇 | |
中国医学 | 4258篇 |
肿瘤学 | 1728篇 |
出版年
2025年 | 298篇 |
2024年 | 998篇 |
2023年 | 1348篇 |
2022年 | 2162篇 |
2021年 | 2775篇 |
2020年 | 2353篇 |
2019年 | 2093篇 |
2018年 | 2063篇 |
2017年 | 2006篇 |
2016年 | 2174篇 |
2015年 | 2119篇 |
2014年 | 4321篇 |
2013年 | 3986篇 |
2012年 | 3494篇 |
2011年 | 3781篇 |
2010年 | 2932篇 |
2009年 | 2539篇 |
2008年 | 2350篇 |
2007年 | 2291篇 |
2006年 | 1932篇 |
2005年 | 1538篇 |
2004年 | 1231篇 |
2003年 | 984篇 |
2002年 | 773篇 |
2001年 | 723篇 |
2000年 | 575篇 |
1999年 | 585篇 |
1998年 | 450篇 |
1997年 | 359篇 |
1996年 | 342篇 |
1995年 | 304篇 |
1994年 | 289篇 |
1993年 | 244篇 |
1992年 | 219篇 |
1991年 | 175篇 |
1990年 | 194篇 |
1989年 | 165篇 |
1988年 | 149篇 |
1987年 | 115篇 |
1986年 | 101篇 |
1985年 | 122篇 |
1984年 | 115篇 |
1983年 | 75篇 |
1982年 | 84篇 |
1981年 | 61篇 |
1980年 | 88篇 |
1979年 | 66篇 |
1978年 | 53篇 |
1977年 | 50篇 |
1976年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
1.
2.
Twenty-four chronic schizophrenic long-stay hospital patients were identified, who had not received neuroleptic drugs for 8–30 (average 8 months) and met or exceeded a minimum criterion of severity of negative symptoms. They were rendomly alocated to either sulpiride 200 mg twice daily or matching placebo, on a double-blind basis for 12 weeks. The results showed that low-dose sulpiride was significantly better than placebo in relation to improvements in negative symptoms. The changes in social behaviour were complex and not obviously related to symptom improvement; exhibited abnormal behaviour, a major factor in preventing successful return to the community, consistently improved only on the active drug. 相似文献
3.
K. Bak 《Scandinavian journal of medicine & science in sports》1996,6(3):132-144
Competitive swimming is one of the most demanding and time-consuming sports. Swimmers at elite level practice 20–30 h per week. During 1 year's practice, the average top level swimmer performs more than 500,000 stroke revolutions per arm. These innumerable repetitions over many years of hard training together with an increasing muscular imbalance around the shoulder girdle seem to be the main etiological factors in the development of the overuse syndrome swimmer's shoulder. Shoulder pain in swimmers has in general been regarded as synonymous with coracoacromial impingement, i.e. anterior shoulder pain due to rotator cuff tendinitis, but new knowledge suggests that a concomitant glenohumeral instability plays an additional role. The diagnostic complexity of the problem is as challenging as the search for the gold standard of treatment. The condition should ideally be diagnosed as early as possible, and intensive functional rehabilitation of the shoulder girdle including the scapular muscles should be started in order to restore muscle balance. The surgical possibilities include subacromial decompression in cases of purely mechanical impingement. If a painful glenohumeral instability persists after intensive functional rehabilitation, anterior capsulolabral reconstruction can be performed. Still, however, short- and long-term results show that surgery is less successful in elite athletes involved in overhead sports. Prevention protocols include education of coaches in primary injury prophylaxis and the institution of resistance strength training in prepubescent swimmers. Emphasis should be made to improve muscular balance around the glenohumeral and scapulothoracic joints. 相似文献
4.
David G. Wilder 《American journal of industrial medicine》1993,23(4):577-588
This work is a review of the mechanical factors related to low back pain production in a vibration environment. The sitting posture is an extreme orientation for the lumbar intervertebral disc that 1) increases its internal pressure, 2) increases its anteroposterior shear flexibility, while: 3) decreasing its resistance to buckling instability and 4) stressing the posterior region of the disc. Vibration is an additional mechanical stressor. Several studies suggest that the following preventive measures be taken to reduce the risk of low back pain due to driving: 1) minimize the vibration reaching the driver, 2) avoid lifting or bending immediately following driving, and 3) walk around for a few minutes following driving. © 1993 Wiley-Liss, Inc. 相似文献
5.
Mary Ellen Turner Kanwal Kher Tamara Rakusan Lawrence D’Angelo Sudesh Kapur Dena Selby Patricio E. Ray 《Pediatric nephrology (Berlin, Germany)》1997,11(2):161-163
We describe the clinical and pathological findings of the hemolytic uremic syndrome (HUS) in two children with human immunodeficiency
virus (HIV) infection. Both patients presented with microangiopathic hemolytic anemia, thrombocytopenia, and subsequently
developed renal failure. The diagnosis of HUS was confirmed by renal histopathology in both patients. None of these children
presented with bloody diarrhea, evidence of circulating antibody response to Escherichia coli O157 lipopolysaccharide, or other known risk factors for HUS, except for the presence of HIV infection. Each patient was
treated with intravenous plasma infusion and renal replacement therapy. Their clinical course was characterized by non-oliguria
and lack of significant hypertension throughout the acute phase of the disease. Despite these favorable clinical parameters,
both patients developed end-stage renal failure. The etiology of this atypical HUS characterized by poor renal survival remains
unknown and the role of HIV infection in its pathogenesis, although possible, is unclear.
Received March 5, 1996; received in revised form and accepted October 15, 1996 相似文献
6.
L. Paczek J. Pazik M. Teschner R. M. Schaefer W. Rowinski J. Szmidt K. Abgarowicz L. Gradowska M. Morzycka-Michalik A. Heidland 《Transplant international》1994,7(S1):311-313
Abstract The major reason for late graft losses is chronic rejection. Recently, a large number of studies have indicated that proteolytic enzymes play an important role as mediators of glomerular injury. The cysteine proteinases cathepsins B and L degrade structural matrix proteins such as type I collagen and laminin. We investigated intraglomerular protease activities in 12 patients after kidney graftectomy because of end-tage renal disease following chronic rejection. A group of 12 patients undergoing nephrectomy because of cancer served as controls using only non-involved parts of the kidney. The activities of cathepsins B and L in homogenates of isolated glomeruli were measured fluorometrically methylcoumarylamidc substrates and related to DNA content. In rejected kidney allografts we observed significantly enhanced intraglomerular cathepsin B activity and cathepsin B + L activity. 相似文献
7.
Gü l Gü rsel Haluk Tü rktas Nahide G k ora Ishak
zel Tekin 《The Journal of asthma》1997,34(4):313-319
The aim of the present study was to investigate whether sputum eosinophil cationic protein (ECP) concentrations could be a useful marker in the differential diagnosis between intrinsic asthma and chronic obstructive pulmonary disease (COPD). For this purpose total blood eosinophil counts were obtained and concentrations of serum and sputum ECP from 10 nonatopic asthmatics with a mild attack and 9 COPD patients with acute exacerbation were measured by radioimmunoassay. Mean serum ECP concentration was 54.3 ± 23.0 g/L in the asthmatic group and 83.3 ± 79.2 g/L in the COPD group (p: n.s.). In the group of asthmatics mean sputum ECP level was 984.5 ± 1245.5 mg/L/g sputum and in the COPD group it was 417.5 ± 363.5 mg/L/g sputum. There was no significant difference in sputum ECP levels between patients with asthma and COPD. We conclude that neither sputum nor serum ECP levels are useful markers in differential diagnosis of asthma attack and acute exacerbation of COPD. 相似文献
8.
A case of partially reversible chronic renal failure due tolong-term NSAID use is discussed. An analysis of this and similarcases recently reported indicates many similarities betweenchronic NSAID nephropathy and analgesic nephropathy. 相似文献
9.
10.
The effects of withdrawal from continuous administration of cocaine on behavioral sensitivity to apomorphine and monoamine receptor density were examined in rats. Subdermal minipumps that delivered either saline or 20 mg/kg/day cocaine hydrochloride were implanted for 2 weeks. Apomorphine-induced stereotypy (0.5 mg/kg, SC) was examined in separate groups of rats either 4 hr or 7, 28, or 60 days after removal of the minipumps. Transient enhanced sensitivity to apomorphine-induced stereotypy occurred during the course of withdrawal. Animals withdrawn from cocaine for 4 hours did not differ from controls in their sensitivity to apomorphine, whereas animals withdrawn from cocaine for 7 days exhibited an increase in apomorphine-induced oral stereotypy relative to controls. However, the enhanced stereotypy response was no longer evident in animals withdrawn for 28–60 days. The animals were sacrificed after behavioral testing, and their brains were assayed for changes in monoamine receptor density in the frontal cortex, caudate-putamen, and nucleus accumbens. The density of 3H-SCH-23390-labeled D1 receptors was altered in all three regions examined in a time-dependent manner that paralleled the changes in behavioral sensitivity to apomorphine. There was a transient decrease in D1 receptor density that was evident by 7 days following withdrawal from continuous cocaine administration and was no longer evident 28 or 60 days posttreatment. There were no changes in 3H-spiroperidol-labeled D2 receptors, 125-pindolol-labeled β-adrenergic receptors, or 3H-ketanserin-labeled 5-HT2 receptors in any of the regions examined at both 4 hr and 7 days after termination of the cocaine infusion. These findings are discussed in terms of their relevance to developing pharmacologic treatments for withdrawal from cocaine. © 1994 Wiley-Liss, Inc. 相似文献