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   3776篇
  免费   210篇
  国内免费   7篇
耳鼻咽喉   24篇
儿科学   130篇
妇产科学   105篇
基础医学   568篇
口腔科学   74篇
临床医学   455篇
内科学   749篇
皮肤病学   55篇
神经病学   446篇
特种医学   80篇
外科学   241篇
综合类   37篇
一般理论   6篇
预防医学   508篇
眼科学   95篇
药学   214篇
中国医学   6篇
肿瘤学   200篇
  2024年   25篇
  2023年   35篇
  2022年   70篇
  2021年   114篇
  2020年   70篇
  2019年   82篇
  2018年   86篇
  2017年   77篇
  2016年   75篇
  2015年   96篇
  2014年   125篇
  2013年   169篇
  2012年   276篇
  2011年   284篇
  2010年   143篇
  2009年   126篇
  2008年   235篇
  2007年   252篇
  2006年   224篇
  2005年   239篇
  2004年   241篇
  2003年   193篇
  2002年   187篇
  2001年   18篇
  2000年   18篇
  1999年   19篇
  1998年   38篇
  1997年   27篇
  1996年   25篇
  1995年   23篇
  1994年   18篇
  1993年   16篇
  1992年   15篇
  1991年   15篇
  1990年   12篇
  1989年   11篇
  1988年   15篇
  1986年   11篇
  1985年   11篇
  1984年   16篇
  1983年   12篇
  1982年   18篇
  1981年   16篇
  1979年   21篇
  1978年   9篇
  1977年   12篇
  1976年   9篇
  1975年   10篇
  1964年   9篇
  1962年   9篇
排序方式: 共有3993条查询结果,搜索用时 15 毫秒
11.
Alcohol dependence is a leading cause of morbidity and mortality in Native Americans, yet biological factors underlying the disorder in this ethnic group remain elusive. This study's aims were to map susceptibility loci for DSM-III-R alcohol dependence and two narrower alcohol-related phenotypes in Mission Indian families. Each participant gave a blood sample and completed an interview using the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA) that was used to make alcohol dependence diagnoses and the narrower phenotypes of withdrawal, and drinking severity. Genotypes were determined for a panel 791 microsatellite polymorphisms. Analyses of multipoint variance component LOD scores for the dichotomous DSM-III-R phenotype revealed no peak LOD scores that exceeded 2.0 at any chromosome location. Two chromosomes, 4 and 12, had peak LOD scores that exceeded 2 for the alcohol use severity phenotype and three chromosomes 6, 15, 16 were found to have peaks with LOD scores that exceeded 2 for the withdrawal phenotype. Evidence for linkage to chromosomes 4 and 15, and 16 have been reported previously for alcohol related phenotypes whereas no evidence has as yet been reported for chromosomes 6 and 12. Combined linkage and association analysis suggest that alcohol dehydrogenase 1B gene polymorphisms are partially responsible for the linkage result on chromosome 4 in this population. These results corroborate the importance of several chromosomal regions highlighted in prior segregation studies in alcoholism and further identify new regions of the genome that may be unique to either the restricted phenotypes evaluated or this population of Mission Indians.  相似文献   
12.
Fifteen patients with Stage IIIB or IV non-small cell lung cancer gave informed consent to receive three or more 96-hour infusions of ATP at a dose of 50 mcg/kg/min or higher to determine whether ATP has antineoplastic activity against this tumor type and to better define the spectrum of toxicity for ATP given as a single agent. There were no objective complete or partial responses observed. The median survival of the overall group was 187 days and the median time to tumor progression was 113 days. The major toxic side effects were chest pain and dyspnea, leading to the cessation of treatment in 5 patients. We conclude that ATP at this dose and schedule of administration is an inactive agent in patients with advanced non-small cell lung cancer.  相似文献   
13.
14.
Accessory ossicles of the foot are commonly mistaken for fractures. The accessory navicular is one of the most common accessory ossicles of the foot. There is a higher incidence in women and the finding might be bilateral in 50?90%. This entity is usually asymptomatic, although populations with medial foot pain have a higher prevalence. Three types of accessory navicular bone have been described. The type II accessory navicular is the most commonly symptomatic variant with localized chronic or acute on chronic medial foot pain and tenderness with associated inflammation of overlying soft tissues. Plain radiographic identification of the accessory navicular is insufficient to attribute symptomatology. Ultrasound allows for comparison with the asymptomatic side and localization of pain. Bone scintigraphy has a high sensitivity but positive findings lack specificity. Magnetic resonance imaging is of high diagnostic value for demonstrating both bone marrow and soft tissue oedema.  相似文献   
15.
After allantoic injection of chick embryos with a known amount of influenza virus, the process of adsorption of the agent onto host cells and infection of them can be interrupted at a given time by the administration of large quantities of heterologous virus inactivated by irradiation. A sudden great increase in the amount of free virus in the allantoic fluid occurring after 6 hours in the case of the PR8 strain, and 9 hours in that of the Lee strain, indicates that the untreated virus associated with the host cells has multiplied. The length of the period preliminary to this increase remains the same even though the concentration of the original inoculum is varied over a wide range. Since administration of the irradiated virus leaves no susceptible host cells, because of the interference phenomenon, and further adsorption of active virus is minimized or entirely prevented, practically the entire new increment of virus can be found in the allantoic fluid and assayed; for every ID50 adsorbed about 50 ID50 are released. Homologous irradiated virus, on the other hand, when injected after infection of the allantoic sac, reduces the yield of virus to a more or less considerable extent. Some inhibitory effect can still be observed when the homologous irradiated virus is given several hours after infection. This effect is linked to the virus particle and destroyed by prolonged irradiation.  相似文献   
16.
17.
18.
Treatment for Legg-Perthes disease should provide dynamic maintenance of the femoral head in the acetabulum, with the hip in moderate abduction and some internal rotation, and minimize stress of body weight on the avascular femoral head. The trilateral socket hip abduction orthosis accomplishes both goals while allowing the patient to be ambulatory and to participate in normal daily activities.  相似文献   
19.
20.

Introduction

Biliary atresia (BA) is a rare, potentially life-threatening condition of the newborn presenting with conjugated jaundice. Typically, it is treated by an initial attempt to restore bile flow (the Kasai portoenterostomy [KP]) as soon as possible after diagnosis and, if this fails, liver transplantation. Since 1999, the treatment of BA has been centralized to 3 centers in England and Wales able to offer both treatment options. The aim of this study was to review the outcome of this policy change and provide a national benchmark.

Methods

The management of all infants born within England and Wales during the period January 1999 to December 2009 was assessed using 3 key performance indicators such as median time to KP, percentage clearance of jaundice (≤20 mol/L) post-KP, and 5- and 10-year native liver and true survival estimates. Data are quoted as median (range), and P < .05 was considered significant.

Results

A total of 443 infants had confirmed BA; and of these, most were isolated BA (n = 359), with 84 having other significant anomalies (but predominantly BA splenic malformation syndrome). Four infants died before any biliary intervention. Kasai portoenterostomy was performed in 424 infants (median age, 54 [range 7-209] days), and a primary liver transplant was performed in 15. Clearance of jaundice post-KP was achieved in 232 (55%). There were 41 deaths, including 4 (10%) without any intervention, 24 (58%) post-KP usually because of end-stage liver disease and mostly on a transplant waiting list, and 13 (32%) post-LT usually because of multiorgan failure. Overall, the 5- and 10-year native liver survival estimates were 46% (95% confidence interval [CI], 41-51) and 40% (95% CI, 34-46), respectively. The 5- and 10-year true patient survival estimates were 90% (95% CI, 88-93) and 89% (95% CI, 86-93), respectively. Outcome was worse for those with other anomalies (lower clearance of jaundice post-KP [43% vs 57%; odds ratio, 1.7; 95% CI, 1.04-2.8]; P = .02) and an increased mortality overall (eg, at 5 years, 72 [95% CI, 64-83] vs 94 [95% CI, 91-96]; χ2 = 33; P < .0001).

Conclusions

National outcome measures in BA appear better than those from previously published series from comparable countries and may be attributed to centralization of surgical and medical resources.  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