全文获取类型
收费全文 | 933837篇 |
免费 | 66466篇 |
国内免费 | 1344篇 |
专业分类
耳鼻咽喉 | 12965篇 |
儿科学 | 24413篇 |
妇产科学 | 23290篇 |
基础医学 | 133100篇 |
口腔科学 | 28292篇 |
临床医学 | 80724篇 |
内科学 | 183688篇 |
皮肤病学 | 19251篇 |
神经病学 | 72321篇 |
特种医学 | 36932篇 |
外国民族医学 | 80篇 |
外科学 | 152455篇 |
综合类 | 18048篇 |
现状与发展 | 1篇 |
一般理论 | 234篇 |
预防医学 | 61860篇 |
眼科学 | 21361篇 |
药学 | 72654篇 |
3篇 | |
中国医学 | 2162篇 |
肿瘤学 | 57813篇 |
出版年
2018年 | 9017篇 |
2017年 | 7072篇 |
2016年 | 7811篇 |
2015年 | 8903篇 |
2014年 | 12047篇 |
2013年 | 17572篇 |
2012年 | 24185篇 |
2011年 | 25139篇 |
2010年 | 14850篇 |
2009年 | 14318篇 |
2008年 | 24675篇 |
2007年 | 25767篇 |
2006年 | 26566篇 |
2005年 | 25523篇 |
2004年 | 24646篇 |
2003年 | 23690篇 |
2002年 | 23219篇 |
2001年 | 54792篇 |
2000年 | 56606篇 |
1999年 | 47015篇 |
1998年 | 10758篇 |
1997年 | 9490篇 |
1996年 | 9613篇 |
1995年 | 8938篇 |
1994年 | 8290篇 |
1993年 | 7600篇 |
1992年 | 35525篇 |
1991年 | 33949篇 |
1990年 | 32777篇 |
1989年 | 31910篇 |
1988年 | 29014篇 |
1987年 | 28278篇 |
1986年 | 26328篇 |
1985年 | 25174篇 |
1984年 | 17864篇 |
1983年 | 15152篇 |
1982年 | 7806篇 |
1981年 | 6784篇 |
1979年 | 15798篇 |
1978年 | 10617篇 |
1977年 | 9062篇 |
1976年 | 7884篇 |
1975年 | 8631篇 |
1974年 | 10478篇 |
1973年 | 9869篇 |
1972年 | 9369篇 |
1971年 | 8855篇 |
1970年 | 8435篇 |
1969年 | 7928篇 |
1968年 | 7205篇 |
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
991.
T Juhás 《Ceskoslovenská oftalmologie》1990,46(5):367-370
Based on repeated fluoroangiographic examinations in a group of 28 children with type I diabetes mellitus the authors observed progressing diabetic retinal changes. At the end of the three-year observation period they found progress in 32% of the children. They investigated influence of risk factors such as age, duration of the basic disease, its metabolic compensation, sex and HLA typing on the development of diabetic retinopathy. 相似文献
992.
The laminar structure and cellular distribution of cytochrome-oxidase (CO) reactivity in supragranular puffs of striate cortex was examined in adult macaque monkeys surviving various periods of monocular enucleation, lid suture, and retinal impulse blockage with tetrodotoxin (TTX). Enucleation and TTX produced a rapid and severe loss in the size of the CO reactive region in puffs dominated by the removed or treated eye compared to slower and less marked reductions obtained in deprived puffs of lid-sutured monkeys. In all deprived animals, the cross-sectional areas of deprived puffs decreased most rapidly in the upper layers (2 and 3A). In long-term enucleated (60 wks) and TTX-treated (4 wks) monkeys, puff area was severely reduced in layer 3B, while reactivity in layer 3B appeared partially spared in lid-sutured monkeys. The density of the CO reaction product was significantly and evenly reduced throughout deprived puffs for all of the monkeys examined; however, this decrease was less severe in adult monkeys lid-sutured for 11 wks. Although no evidence for cell loss was obtained, all three forms of visual deprivation led to lower counts of neuronal perikarya with high levels of CO reaction product in both deprived puff and interpuff areas. This effect was less marked in the deprived puffs of monkeys lid-sutured for 2.5 and 3 yrs, suggesting recovery of CO activity in some neurons. Neurons in deprived puffs and interpuffs were generally similar in size to those in nondeprived regions, although CO-reactive cells were significantly smaller in the deprived puffs of monkeys enucleated for 28.5 or 60 wks. These results indicate that the metabolic response of neuronal elements in supragranular striate cortex depends upon the nature of the visual deficit. The partial sparing of CO reactivity in deprived puffs of lid-sutured monkeys may reflect the continued transmission of certain types of visual stimuli through a closed eyelid. 相似文献
993.
994.
Immunoblotting of streptococcal antigens in guttate psoriasis 总被引:6,自引:0,他引:6
A.G.McT. WILSON I. CLARK S.R. HEARD† D.D. MUNRO J.D.T. KIRBY 《The British journal of dermatology》1993,128(2):151-158
Guttate psoriasis may be precipitated by acute streptococcal infection, usually of the upper respiratory tract. We have studied the immune response to streptococci in 26 patients presenting with a first or recurrent episode of acute guttate psoriasis (AGP), using immunoblotting. Eighteen of 26 patients studied had a demonstrable response to a wide range of streptococcal antigens using this approach, compared with 14 of 26 patients who demonstrated a response using more conventional anti-streptococcal antibody tests. Patients with AGP had a significantly higher antibody detection score using immunoblotting than did control subjects (P<0.005). We conclude that immunoblotting is a useful technique in studying this condition and may be of benefit in exploring the immunopathogene-sis of AGP. 相似文献
995.
Trazodone hydrochloride is an oral antidepressant agent which has been associated with the improvement of erections in impotent men and the development of prolonged erections or priapism in potent men. An in vivo study in animal and human subjects was performed to gain experience with the effect of intracavernosal trazodone. In the anesthetized New Zealand White rabbit, intracavernosal trazodone or its major metabolite m-chlorophenylpiperazine (m-CPP) produced full penile erection in 76% and 84% of animals studied respectively with doses ranging from one to 15 mg. On the other hand, intracavernosal administration of five mg. papaverine resulted in a prolonged erection in 90% of animals studied. In 13 selected volunteer patients, intracavernosal trazodone caused tumescence but not full penile erection with corporal body pressures of 28.2 +/- 5.8 mm. Hg. Intracavernosal papaverine or papaverine and phentolamine in these subjects resulted in significantly higher corporal body pressures of 58 +/- 18 mm. Hg (p less than .05). Intracavernosal administration of alpha adrenoceptor agonists but not normal saline resulted in complete detumescence of trazodone- or m-CPP-induced prolonged erection in the animal studies. Intracavernosal trazodone results in erectile activity that appears in part based on its local alpha blocking activity but like other intracavernosal alpha-blocking agents is not as effective in initiating penile erections as are intracavernosal agents that directly induce smooth muscle relaxation. 相似文献
996.
A A Korzh N I Kulish V A Tan'kut V T Mikha?liv 《Ortopediia travmatologiia i protezirovanie》1990,(10):1-7
On the basis of analysis of surgical treatment of 753 patients with coxarthrosis during 1970-1987, the authors set forth the stages of arthroplasty development in the USSR, using the experience of the Kharkov research institute of orthopaedics and traumatology named after M. I. Sitenko on the problems of arthrodesis operations, endoprosthetics and biological arthroplasty. In the article are presented the peculiar features of diagnostic and surgical tactics in case of patients with idiopathic and dysplastic coxarthrosis; operation technique for each form is presented in details. The authors have developed a new perosseous access to the hip joint, which made a good showing and permits to preserve the integrity of periarticular muscles and neurovascular formations. Application of the given access made possible the extension of indications for arthroplasty in case of grave forms of coxarthrosis, met earlier in a reserved manner. 相似文献
997.
998.
A 10-month-old child with achondroplasia with progressive head enlargement, ventriculomegaly, and wide subarachnoid spaces over the hemispheres was referred for evaluation. A steady-state lumbar infusion test revealed increased cerebrospinal fluid (CSF) outflow resistance (14 mm Hg/ml/min), and intra-arterial digital subtraction angiography (DSA) demonstrated bilateral venous outflow obstruction due to stenosis of the jugular foramen. Surgical decompression by opening the right jugular foramen relieved the clinical signs of intracranial hypertension. During the following year, the patient's head enlargement was moderate with relative normalization of size. Repeat DSA demonstrated improved venous runoff on the right side, and a steady-state lumbar infusion test demonstrated reduced CSF outflow resistance (10 mm Hg/ml/min). Venous decompression is causal therapy and may prove to be preferable to shunting in children with hydrocephalus and bilateral stenosis of the jugular foramen. 相似文献
999.
1000.