首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   21296篇
  免费   1484篇
  国内免费   88篇
耳鼻咽喉   144篇
儿科学   669篇
妇产科学   521篇
基础医学   3375篇
口腔科学   400篇
临床医学   2102篇
内科学   4200篇
皮肤病学   461篇
神经病学   2246篇
特种医学   518篇
外科学   2043篇
综合类   119篇
一般理论   27篇
预防医学   2240篇
眼科学   369篇
药学   1246篇
中国医学   38篇
肿瘤学   2150篇
  2023年   188篇
  2022年   342篇
  2021年   640篇
  2020年   424篇
  2019年   606篇
  2018年   688篇
  2017年   530篇
  2016年   611篇
  2015年   700篇
  2014年   847篇
  2013年   1193篇
  2012年   1692篇
  2011年   1682篇
  2010年   952篇
  2009年   845篇
  2008年   1489篇
  2007年   1420篇
  2006年   1297篇
  2005年   1255篇
  2004年   1093篇
  2003年   1120篇
  2002年   974篇
  2001年   142篇
  2000年   89篇
  1999年   122篇
  1998年   184篇
  1997年   154篇
  1996年   124篇
  1995年   123篇
  1994年   103篇
  1993年   100篇
  1992年   55篇
  1991年   68篇
  1990年   53篇
  1989年   49篇
  1988年   27篇
  1987年   44篇
  1986年   45篇
  1985年   54篇
  1984年   55篇
  1983年   46篇
  1982年   71篇
  1981年   54篇
  1980年   45篇
  1979年   37篇
  1978年   34篇
  1976年   30篇
  1975年   26篇
  1974年   33篇
  1973年   28篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
Nonconvulsive Status Epilepticus: High Incidence of Complex Partial Status   总被引:14,自引:6,他引:8  
Nonconvulsive status epilepticus may be subdivided into generalized (absence) status and complex partial status. The latter is regarded as a rarity, whereas the former constitutes the dominant part of the hitherto reported cases. We report 10 consecutive cases of adult patients with nonconvulsive status epilepticus, all documented by ictal electroencephalographic (EEG) recordings. Five had a complex partial status; the origin of the complex partial status appeared to be frontal in four of these patients. Three had recurrent complex partial seizures with incomplete recovery between seizures, and two had more continuous symptoms. One of the latter exhibited neither motor phenomena nor automatisms. The effect of diazepam or clonazepam was immediate in all 10 cases though transient in eight. A lasting control of the status was not achieved in six patients until i.v. phenytoin was added. The difficulties in the differentiation between complex partial status and absence status despite ictal EEG recordings are discussed, illustrated by a case with seizure discharges of a focal onset which rapidly generalized. The study indicates that complex partial status may be more common and the clinical expressions of absence status more variable than hitherto recognized.  相似文献   
24.
To determine whether polymorphisms of platelet surface glycoprotein associated with arterial thrombosis are risk factors for branch retinal vein occlusion. A case-control study in which 69 patients with branch retinal vein occlusion and 147 controls who attended the eye clinic for nonvascular complications participated. DNA was extracted from whole blood and analyzed for genotyping of platelet glycoprotein polymorphisms by polymerase chain reactions and specific restricted enzymes. No relationship was found between the four platelet glycoprotein polymorphisms i.e. GPIa C807T, VNTR and Kozak of glycoprotein Ibalpha, the HPA-1 of glycoprotein IIIa and the occurrence of branch retinal vein occlusion. The HPA-2 polymorphism was found in 18 out 60 (30%) patients with branch retinal vein occlusion in comparison with 27 out 142 (19%) of controls, with an estimated odds ratio of 1.8 (95% confidence interval, 0.91-3.65). The four platelet glycoprotein polymorphisms are not risk factors for branch retinal vein occlusion and therefore it seems unnecessary to screen those patients for it. A larger study is required, however, to determine whether HPA-2 is a novel risk factor for branch retinal vein occlusion.  相似文献   
25.
With 1–1.5 million cases reported every year cutaneous leishmaniasis represents an increasing health problem. The course of cutaneous leishmaniasis varies from a single self‐healing ulcer to a persistent ulcer or progressive mucosal disease with nasopharyngeal destruction. An enormous array of topical and systemic treatment modalities has been endorsed. The response to treatment depends on the species of parasite as well as the host's immunological and genetic status. Species‐specific treatment guidelines based on evidence from controlled studies are highly desirable. We present two cases of cutaneous leishmaniasis, one in a child and one during pregnancy, reviewing various diagnostic and therapeutic measures with special attention to problems in young and pregnant patients.  相似文献   
26.
Cationic block copolymers spontaneously assemble via electrostatic interactions with DNA molecules in aqueous solution giving rise to micellar structures that protect the DNA from enzymatic degradation both in vitro and in vivo. In addition, we have previously shown that they are safe, not immunogenic and greatly increased antigen-specific CTL responses following six intramuscular inoculations of a very low dose (1 μg) of the vaccine DNA as compared to naked DNA. Nevertheless, they failed to elicit detectable humoral responses against the antigen. To gain further insight in the potential application of this technology, here we show that a shorter immunization protocol based on two DNA intramuscular inoculations of 1 μg of DNA delivered by these copolymers and a protein boost elicits in mice broad (both humoral and cellular) and long-lasting responses and increases the antigen-specific Th1-type T cell responses and CTLs as compared to priming with naked DNA. These results indicate that cationic block copolymers represent a promising adjuvant and delivery technology for DNA vaccination strategies aimed at combating intracellular pathogens.  相似文献   
27.
We demonstrate that a mixture of four recombinant dengue virus E polypeptides corresponding to the N-terminal region of the envelope protein from all serotypes substitutes for standard antigens in two immunoglobulin M enzyme-linked immunosorbent assay formats with 100% concordance, making these polypeptides a useful and accessible reagent for serological diagnosis of dengue in endemic countries.  相似文献   
28.
29.
This prospective randomized controlled outcome study was designed to evaluate whether a MultiModal Cognitive—Behavioral Treatment for chronic spinal pain (MMCBT) specifically designed for women has an increased effect on well being and return to work compared to a regular MMCBT regimen. In Sweden, spinal pain is most prevalent among women. A tremendous amount of money is spent on secondary prevention of spinal pain. Yet, little is known about the effect of the interventions. A need for well designed outcome studies exist. Fifty-four subjects from a cohort of all registered sick-listed women in three districts of Stockholm participated in the study. Subjects were allocated by central randomization into two groups. One group was treated with a regular MMCBT program and the other group with a MMCBT program specifically designed for women. Assessments were performed at pretreatment–posttreatment (last treatment day) and at 6 and 18 months posttreatment. Questionnaires covering the bio-psycho-social spectra of the chronic pain syndrome, and sick leave were used to measure outcome. Intention to treat and true to protocol analyses were performed. The only significant differences found between groups were improvements in self-reported disability and in coping with pain, favoring the experimental treatment. About one-third of the variance in disability was explained by the set of pain-coping strategies assessed in the study. The results do not lend sufficient statistical support to warrant acceptance of the experimental treatment as superior to the regular treatment in improving health and sick leave. Further investigation with larger groups is needed before a solid scientific conclusion can be drawn.  相似文献   
30.
熵代表无序的水平,作者使用通气的熵变(ECV)指示肺通气的不均匀性,ECV定义为当前泡潮气量趋近于零时每摩尔被吸入气体从不均匀通气到均匀通气的熵变的极限。本文从熵的基本公式民地出ECV的计算方程。用几个数学模型肺将ECV同其他7个洗出指标进行了比较。8个指标中,只有ECV仅取决于通气分布,其他7个指标不仅取决于通气分布,还同潮气量和死腔的大小有关。这影响了它们评价肺通气不均匀性的效果,ECV的另一  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号