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   3962篇
  免费   276篇
  国内免费   17篇
耳鼻咽喉   39篇
儿科学   207篇
妇产科学   50篇
基础医学   522篇
口腔科学   70篇
临床医学   287篇
内科学   716篇
皮肤病学   77篇
神经病学   389篇
特种医学   205篇
外科学   565篇
综合类   161篇
一般理论   5篇
预防医学   258篇
眼科学   84篇
药学   326篇
中国医学   10篇
肿瘤学   284篇
  2023年   34篇
  2022年   66篇
  2021年   128篇
  2020年   59篇
  2019年   100篇
  2018年   157篇
  2017年   86篇
  2016年   112篇
  2015年   122篇
  2014年   176篇
  2013年   178篇
  2012年   260篇
  2011年   288篇
  2010年   183篇
  2009年   138篇
  2008年   243篇
  2007年   245篇
  2006年   180篇
  2005年   202篇
  2004年   181篇
  2003年   155篇
  2002年   119篇
  2001年   95篇
  2000年   96篇
  1999年   86篇
  1998年   29篇
  1997年   29篇
  1996年   19篇
  1995年   19篇
  1994年   7篇
  1993年   13篇
  1992年   34篇
  1991年   54篇
  1990年   35篇
  1989年   33篇
  1988年   35篇
  1987年   36篇
  1986年   30篇
  1985年   20篇
  1984年   22篇
  1983年   20篇
  1982年   7篇
  1981年   11篇
  1980年   12篇
  1979年   11篇
  1978年   12篇
  1977年   11篇
  1976年   10篇
  1975年   8篇
  1973年   7篇
排序方式: 共有4255条查询结果,搜索用时 15 毫秒
11.
12.
This study was undertaken to record the Brainstem Evoked Responses in a group of 20 diabetic patients with normal hearing and were compared with responses of another group of 20 normal individuals. Eighth nerve transmission till the level of cochlear nucleus was found to be normal in diabetics. The delay in latency of Wave III, IV and V and interpeak latencies (I–III, I–V) were noted to be statistically significant, thus suggesting the presence of central neuropathy in patients with diabetes. No significant sex difference on latency of waves was observed.  相似文献   
13.
We observed a 7-year-old boy with virtual absence of renal tubular glucose reabsorption (type O renal glucosuria). Glucose titration studies in his family revealed severe type A renal glucosuria in a younger brother, a mild type A defect in the mother and normal glucose reabsorption in the father; thus a spectrum of renal glucose transport defects was observed in members of the same family.  相似文献   
14.
Costello syndrome (CS) is a RASopathy caused by activating germline mutations in HRAS. Due to ubiquitous HRAS gene expression, CS affects multiple organ systems and individuals are predisposed to cancer. Individuals with CS may have distinctive craniofacial features, cardiac anomalies, growth and developmental delays, as well as dermatological, orthopedic, ocular, and neurological issues; however, considerable overlap with other RASopathies exists. Medical evaluation requires an understanding of the multifaceted phenotype. Subspecialists may have limited experience in caring for these individuals because of the rarity of CS. Furthermore, the phenotypic presentation may vary with the underlying genotype. These guidelines were developed by an interdisciplinary team of experts in order to encourage timely health care practices and provide medical management guidelines for the primary and specialty care provider, as well as for the families and affected individuals across their lifespan. These guidelines are based on expert opinion and do not represent evidence‐based guidelines due to the lack of data for this rare condition.  相似文献   
15.
16.
INTRODUCTION: Individuals who have difficulty gaining access to health care may delay seeking and obtaining treatment, underutilize preventive health care services, and may have a high prevalence of chronic disease risks. This report examines participant perception of the level of difficulty encountered when obtaining medical care and its influence on the prevalence of chronic disease behavioral risks among urban African Americans. RESULTS: We found a significantly higher prevalence of current cigarette smoking and alcohol consumption among African Americans who reported that they experienced difficulty in obtaining medical care than among those who did not. Compared to those who experienced no difficulty obtaining care, participants who perceived a high level of difficulty in obtaining care were less likely to have had a physical exam in the past year and to have seen the same doctor when services were obtained. CONCLUSION: The perception of a high level of difficulty obtaining health care may be associated with a higher prevalence of behavioral risks for chronic disease. The limited data suggest a need to more closely examine the perception of health care accessibility and its relationship to health services utilization and the prevalence of chronic disease behavioral risks.  相似文献   
17.
The purpose of this study was to determine if phosphocitrate (PC), a naturally occurring inhibitor of calcification, and its synthetic analogue, N-sulpho-2-amino tricarballylate (SAT), administered either by daily injection or local delivery via Alzet osmotic minipump, could inhibit calcification of glutaraldehyde-preserved bovine pericardium used in bioprosthetic heart valves, subcutaneously implanted in rats. Local drug delivery, but not systemic administration, was effective. PC, administered by Alzet minipump (12 mg.kg-1.day-1), inhibited calcification significantly (tissue calcium = 5 +/- 2 micrograms/mg dry tissue, mean +/- SEM), compared with untreated or saline-treated controls (89 +/- 9 and 49 +/- 9 micrograms/mg, respectively). SAT, administered by the same route at both the same and a higher molar dosage, was less potent (tissue calcium = 26 +/- 9 micrograms/mg and 17 +/- 5 micrograms/mg, respectively). PC and SAT therapy were not associated with adverse effects. We conclude that locally administered PC and SAT can inhibit intrinsic calcification of bovine pericardium, with PC being more potent.  相似文献   
18.
One hundred and forty eight subjects with euthyroid solitary thyroid nodules (STN) were taken up for radionuclide perfusion study. They were found to have a cold STN on 99mTc thyroid static scan. All had fine needle aspiration cytology (FNAC), and except for subjects with chronic lymphocytic thyroiditis, were subjected to surgery for tissue diagnosis by histopathology. The diagnostic findings in these patients of solitary thyroid nodules were correlated with the histopathology. Radionuclide perfusion study is considered useful to differentiate benign from malignant cold thyroid solitary nodules with high degree of sensitivity (95%) and specificity (87.9%).  相似文献   
19.
Monoclonal antibody CIBCNSH3 of IgG1 isotype has been generated against human epidermal growth factor receptor (EGFR) using MDA MB 468 breast carcinoma cell line as immunogen. Earlier studies have revealed that this MAb blocked growth factor-receptor interaction and thus inhibited cell proliferation and tumor growth. In the present paper, this MAb has been extensively characterized to evaluate its application in the study of human cancers. The results were compared with those obtained using a control MAb ICR 62 specific to EGFR. Competitive assay showed that this MAb bound to an epitope in the extracellular domain of the EGFR to which MAb ICR 62 also bound. This MAb immunoprecipitated the 170 kD glycoprotein. The specificity was further confirmed by the formation of a single discrete band in western blot analysis. By flow cytometric analysis this monoclonal antibody revealed high binding affinity with MDA MB 468 cells. By immunocytochemical assay, out of 35 breast tumors studied, 40% were found to exhibit strong cell membrane staining and in the case of 25 oral cancers studied, 56% were strong positive. High expression of EGFR was observed in MDA MB 468 cells and HN 5 cells. These studies clearly indicate that MAb CIBCNSH3 might prove useful to identify tumors with high level of expression of EGFR associated with poor prognosis.  相似文献   
20.
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