全文获取类型
收费全文 | 1604332篇 |
免费 | 131666篇 |
国内免费 | 2588篇 |
专业分类
耳鼻咽喉 | 21667篇 |
儿科学 | 53008篇 |
妇产科学 | 46319篇 |
基础医学 | 228136篇 |
口腔科学 | 47226篇 |
临床医学 | 141293篇 |
内科学 | 315266篇 |
皮肤病学 | 34159篇 |
神经病学 | 130375篇 |
特种医学 | 64763篇 |
外国民族医学 | 474篇 |
外科学 | 244084篇 |
综合类 | 39743篇 |
现状与发展 | 3篇 |
一般理论 | 545篇 |
预防医学 | 123236篇 |
眼科学 | 36506篇 |
药学 | 121385篇 |
3篇 | |
中国医学 | 2975篇 |
肿瘤学 | 87420篇 |
出版年
2018年 | 14891篇 |
2016年 | 12995篇 |
2015年 | 15115篇 |
2014年 | 20775篇 |
2013年 | 31494篇 |
2012年 | 42759篇 |
2011年 | 44976篇 |
2010年 | 26439篇 |
2009年 | 25400篇 |
2008年 | 43166篇 |
2007年 | 45414篇 |
2006年 | 46226篇 |
2005年 | 44820篇 |
2004年 | 44219篇 |
2003年 | 42284篇 |
2002年 | 41397篇 |
2001年 | 75698篇 |
2000年 | 78334篇 |
1999年 | 66392篇 |
1998年 | 17742篇 |
1997年 | 16344篇 |
1996年 | 16319篇 |
1995年 | 16027篇 |
1994年 | 15078篇 |
1993年 | 14226篇 |
1992年 | 55430篇 |
1991年 | 53780篇 |
1990年 | 52566篇 |
1989年 | 50836篇 |
1988年 | 47229篇 |
1987年 | 46563篇 |
1986年 | 44291篇 |
1985年 | 42845篇 |
1984年 | 32037篇 |
1983年 | 27572篇 |
1982年 | 16146篇 |
1981年 | 14439篇 |
1980年 | 13569篇 |
1979年 | 30462篇 |
1978年 | 21064篇 |
1977年 | 17767篇 |
1976年 | 16694篇 |
1975年 | 17574篇 |
1974年 | 21486篇 |
1973年 | 20672篇 |
1972年 | 18854篇 |
1971年 | 17770篇 |
1970年 | 16289篇 |
1969年 | 15269篇 |
1968年 | 13949篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
181.
E R Wald 《The Journal of family practice》1988,26(4):367-368
182.
183.
Oil-emulsified (OE) and aqueous (Aq) vaccines were prepared with the same batch of inactivated A24 8345 foot and mouth disease virus (FMDV). Calves born to vaccinated dams did not respond to the Aq vaccine 30 or 90 days post partum. When the OE vaccine was used on a similar group of calves, no responses were elicited up to 21 days post partum. However, calves 30 or more days old responded like adult cattle to the OE vaccine. When the OE vaccine was used in colostral antibody-free calves 3-30 days old, all animals showed good antibody responses but, in calves vaccinated 3 or 7 days post partum, antibodies were detectable only after a considerable period of time. Our results show that both passively acquired colostral antibodies and age are important in the response of very young calves to FMDV oil vaccines. From a practical point of view, in endemic areas where adult cattle are periodically vaccinated, vaccination of calves between 30 and 60 days post partum with OE vaccines would lead to high levels of herd protection. 相似文献
184.
R. OREN Y. MAARAVI F. KARMELI G. KENET L. ZEIDEL A. HUBERT & R. ELIAKIM 《Alimentary pharmacology & therapeutics》1997,11(2):341-345
Background : Methimazole, an anti-thyroid drug, was recently found to be useful in the treatment of systemic lupus erythematosus and other autoimmune diseases. Moreover, decreased thyroid hormone production is associated with a variety of immunological manifestations, such as reduced activation of CD4+ cells, increased CD8+ cell activity and reduced soluble IL-2 receptors. In the present study we examined the effects of methimazole and propylthiouracil on a rat model of experimental colitis.
Methods : Colitis was induced by intracolonic administration of 30 mg trinitrobenzene sulphonic acid (TNB). Two weeks prior to induction of colitis, rats were treated by either methimaziole (0.04%) or propylthiouracil (0.01%) in drinking water after a week of free access to water. Rats were sacrificed 48 h or 7 days after induction of colitis. The colon was isolated, rinsed with ice-cold water and weighed. Damage was assessed both macroscopically and microscopically and myeloperoxidase (MPO) activity determined.
Results : All treated rats were hypothyroid as manifested by a significant elevation of thyroid stimulating hormone (TSH), by comparison with the control groups (mean -1.82±0.40 versus 0.11±0.02 mmol/L, respectively). The inflammatory response elicited by TNB resulted in severe mucosal damage 48 h after damage induction, which persisted for 7 days. Pre-treatment with either methimazole 0.04% or propylthiouracil 0.01% significantly decreased mucosal damage macroscopically (lesion area, lesion score and segmental weight) microscopically and also significantly decreased MPO level at both time points ( P <0.01).
Conclusions : Methimazole and propylthiouracil significantly reduce mucosal damage and colonic weight in a rat model of colitis. The mode by which they do so remains to be studied. 相似文献
Methods : Colitis was induced by intracolonic administration of 30 mg trinitrobenzene sulphonic acid (TNB). Two weeks prior to induction of colitis, rats were treated by either methimaziole (0.04%) or propylthiouracil (0.01%) in drinking water after a week of free access to water. Rats were sacrificed 48 h or 7 days after induction of colitis. The colon was isolated, rinsed with ice-cold water and weighed. Damage was assessed both macroscopically and microscopically and myeloperoxidase (MPO) activity determined.
Results : All treated rats were hypothyroid as manifested by a significant elevation of thyroid stimulating hormone (TSH), by comparison with the control groups (mean -1.82±0.40 versus 0.11±0.02 mmol/L, respectively). The inflammatory response elicited by TNB resulted in severe mucosal damage 48 h after damage induction, which persisted for 7 days. Pre-treatment with either methimazole 0.04% or propylthiouracil 0.01% significantly decreased mucosal damage macroscopically (lesion area, lesion score and segmental weight) microscopically and also significantly decreased MPO level at both time points ( P <0.01).
Conclusions : Methimazole and propylthiouracil significantly reduce mucosal damage and colonic weight in a rat model of colitis. The mode by which they do so remains to be studied. 相似文献
185.
186.
187.
T. Schneider W. Menke B. Fink W. Rüther K. P. Schulitz 《Archives of orthopaedic and trauma surgery》1997,116(1-2):46-49
In this study 17 patients with recurrent dislocation of the patella were followed up 10 years after their Goldthwait operation. The subjective and clinical findings were excellent or good in 70%. X-radiographs indicated osteoarthritis of the femoropatellar joint in 60%. Concerning the aetiopathological factors, we found an increased external torsion of the afflicted extremity (measured by computed tomography). 相似文献
188.
The pulsed tunable dye laser (PTDL) is generally considered to have a very low incidence of adverse effects, allowing it to become the treatment of choice for the majority of port wine stains (PWS). The low incidence of adverse effects has led to difficulties in determining the true incidence and type of adverse effect seen with this laser. We therefore undertook a retrospective study of 701 patients with PWS, who received 3877 full treatments to determine the incidence and type of adverse effects seen following treatment with the PTDL. Blistering and crusting were seen in 5·9% and 0·7% of patients, respectively, but were transient events which usually healed without permanent sequelae. Hyperpigmentation was the most frequently observed adverse effect seen in 9·1% of patients but generally showed gradual resolution over 6–12 months. Hypopigmentation was infrequent, seen in 1.4% of patients. The most significant adverse effects were atrophic and hypertrophic scarring seen in 4·3% and 0·7% of patients, respectively. Our observations show that there is a small but definite risk of atrophic scarring with a predisposition for younger patients. Hypertrophic scarring can occur albeit rarely and there may be a predisposition towards the neck. In most cases test areas were not predictive of scarring. This underlines the need for a full discussion of scarring risk in patients with PWS undergoing treatment with the PTDL. 相似文献
189.
R. LIBERMAN E.C. COMBE† V. PIDDOCK† C. PAWSON D.C. WATTS† 《Journal of oral rehabilitation》1995,22(6):445-449
SUMMARY Current standard specifications for the laboratory evaluation of denture base materials require subjective assessment of colour stability. This study evaluates a new objective measurement technique for translucent denture base materials, by comparing quantitative data with the results obtained from a standard subjective method. Preliminary work on three representative commercial acrylic materials resulted in the selection of a white background for the quantification of colour change of these translucent materials. One half of each sample was exposed to artificial sunlight for 24 h.
The colour of both exposed and unexposed resin was measured on the CIE L*a*b* scale using a photoelectric colorimeter. Significant changes in the b* and E* values (P < 0.001) were observed following light exposure. Objective data for a wide range of commercial materials were compared with the results of a subjective evaluation and it was shown that a change in b* of 1.5 units was discernable subjectively by eye for 100% of the cases. It is suggested that this method and limit value could form the basis of a new objective colour change specification for polymeric dental materials. 相似文献
The colour of both exposed and unexposed resin was measured on the CIE L*a*b* scale using a photoelectric colorimeter. Significant changes in the b* and E* values (P < 0.001) were observed following light exposure. Objective data for a wide range of commercial materials were compared with the results of a subjective evaluation and it was shown that a change in b* of 1.5 units was discernable subjectively by eye for 100% of the cases. It is suggested that this method and limit value could form the basis of a new objective colour change specification for polymeric dental materials. 相似文献
190.