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   2909篇
  免费   214篇
  国内免费   12篇
耳鼻咽喉   29篇
儿科学   80篇
妇产科学   58篇
基础医学   302篇
口腔科学   118篇
临床医学   301篇
内科学   731篇
皮肤病学   90篇
神经病学   247篇
特种医学   115篇
外科学   267篇
综合类   13篇
一般理论   1篇
预防医学   232篇
眼科学   69篇
药学   177篇
中国医学   4篇
肿瘤学   301篇
  2024年   5篇
  2023年   32篇
  2022年   64篇
  2021年   139篇
  2020年   96篇
  2019年   107篇
  2018年   133篇
  2017年   80篇
  2016年   91篇
  2015年   109篇
  2014年   119篇
  2013年   163篇
  2012年   249篇
  2011年   287篇
  2010年   135篇
  2009年   116篇
  2008年   202篇
  2007年   220篇
  2006年   173篇
  2005年   159篇
  2004年   132篇
  2003年   117篇
  2002年   112篇
  2001年   10篇
  2000年   10篇
  1999年   9篇
  1998年   14篇
  1997年   12篇
  1996年   15篇
  1995年   6篇
  1994年   8篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1987年   1篇
  1983年   1篇
  1977年   1篇
  1960年   1篇
  1938年   1篇
排序方式: 共有3135条查询结果,搜索用时 15 毫秒
191.
In this study, 63% of patients with a substantial amount of viable myocardium showed an increased left ventricular ejection fraction (LVEF) 12 +/- 3 months after coronary artery bypass grafting. In 93% of these patients, increased LVEF persisted at 4.5 +/- 1 years of follow-up. Conversely, in nonviable patients, LVEF did not increase at 12 +/- 3 months or at follow-up of 4.5 +/- 1 years.  相似文献   
192.
193.
A 3-month-old male infant with cytomegalovirus infection and intractable partial seizures was treated with ganciclovir for 6 weeks. The drug was well tolerated, and virus shedding in the cerebrospinal fluid and urine was eliminated, although infantile spasms at the age of 6 months appeared. At the age of 12 months, intractable seizures persisted, and the psychomotor development of the infant was markedly delayed. To our knowledge, no previous similar case has been reported. These findings suggest that treatment with ganciclovir of infants with cytomegalovirus infection results only in cessation of virus shedding in the cerebrospinal fluid and urine without having a preventive effect on the future appearance of infantile spasms. This may be due to the irreversibility of previous brain damage from the cytomegalovirus infection and the virostatic nature of the drug.  相似文献   
194.
Although angiogenetic therapy using recombinant growth factors holds much hope for the treatment of ischemic diseases, there are still unanswered questions including the method, doses or duration of therapeutic approach. We evaluated the angiogenetic effects of vascular endothelial growth factor (VEGF) on rat heart and gastrocnemius muscles when this was administered intramuscularly and compared them to those obtained from rats, which exercised daily. CONCLUSION: Both daily swimming exercise and intramuscular administration of VEGF increased angiogenesis in rat heart, even though exercise alone was the only one that increased angiogenesis quite significantly. The combined protocol (administration of growth factor and exercise) led to an increase of angiogenesis in cardiac muscles. In contrast, there was no effect on the lateral gastrocnemius muscle either by VEGF or exercise, whereas these together induced angiogenesis locally at the site of injection.  相似文献   
195.

Background  

Hemangiomas are the most common type of congenital anomaly in childhood. Although many resolve spontaneously, intervention is required when their growth could damage vital adjacent structures. Various therapeutic approaches to childhood hemangiomas with different types of laser have been described previously. The objective of this study was to determine whether the cooling of the epidermis during irradiation of hemangiomas with a Nd:YAG laser prevents thermal damage and decreases the number of sessions required to treat these lesions.  相似文献   
196.
The prevalence and severity of latex allergies have rapidly increased recently. This article presents two cases of patients with rubber latex allergy. The patient in case A was unaware of her sensitivity to latex and presented symptoms of contact dermatitis-stomatitis during endodontic treatment. The patient in case B reported latex allergy before the initiation of the treatment and a different approach was followed. Certain aspects of latex allergy related to the endodontic treatment are discussed. Moreover, a protocol is proposed for treatment of patients with latex hypersensitivity with safety.  相似文献   
197.
In 1968, Melzack and Casey suggested that there are three major psychological dimensions of pain: sensory, affect, evaluative. These categories interact with one another to provide quantitative and qualitative information on the components of pain. In 1975, Melzack developed the McGill Pain Questionnaire, which is composed of four major parts and evaluates the qualities of pain. The aim of this study was to assess the applicability, reliability, and validity of the McGill Pain Questionnaire on a sample of Greek cancer patients receiving palliative treatment. It was administered to 114 cancer patients before the initiation of the palliative treatment, and then to 80 cancer patients during the treatment 7 days later. The results indicated that scale reliability was very good (0.95-0.97). During the pretreatment period, correlations between Present Rating Index (PRI), Present Pain Intensity (PPI), and Number of Words Chosen (NWC) ranged between 0.42 and 0.92. During the post-treatment time, the correlations ranged between 0.28 and 0.91. Only 21.8% of the words met a criterion of 30% for representativeness on the first administration of the questionnaire, and 9% met this criterion on the second. Validity was satisfactory (P < 0.005) according to "responsiveness to changes in time", as there was a statistical difference between the pretreatment and post-treatment time. Patients presented a desirable level of convergent construct validity (P < 0.05) concerning their performance status. Exploratory factor analysis was examined and two factors with eigenvalue over 1 were extracted, and they accounted for 95.2% of the variance. These results support the Greek-MPQ as a reliable and valid measure for evaluating the qualities of cancer pain in patients receiving palliative care.  相似文献   
198.
199.
200.
Fluoxetine (Prozac) is the most widely prescribed medication for the treatment of depression. Nevertheless, little is known about the molecular basis of its clinical efficacy, apart from the fact that fluoxetine increases the synaptic availability of serotonin. Here we show that, in vivo, fluoxetine, given either acutely or chronically, regulates the phosphorylation state of dopamine- and cAMP-regulated phosphoprotein of M(r) 32,000 (DARPP-32) at multiple sites in prefrontal cortex, hippocampus, and striatum. Acute administration of fluoxetine increases phosphorylation of DARPP-32 at the protein kinase A site, Thr-34, and at the casein kinase-1 site, Ser-137, and decreases phosphorylation at the cyclin-dependent kinase 5 site, Thr-75. Each of these changes contributes, through distinct signaling pathways, to increased inhibition of protein phosphatase-1, a major serine/threonine protein phosphatase in the brain. Fluoxetine also increases phosphorylation of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit GluR1 at Ser-831 and Ser-845. Both the fluoxetine-mediated increase in AMPA receptor phosphorylation at Ser-845-GluR1 and the beneficial responsiveness to fluoxetine in an animal test of antidepressant efficacy were strongly reduced in DARPP-32 knockout mice, indicating a critical role for this phosphoprotein in the antidepressant actions of fluoxetine. Mice chronically treated with fluoxetine had increased levels of DARPP-32 mRNA and protein and a decreased ability to increase phospho-Ser-137-DARPP-32 and phospho-Ser-831-GluR1. These chronic changes may be relevant to the delayed onset of therapeutic efficacy of fluoxetine.  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