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   167272篇
  免费   18199篇
  国内免费   4976篇
耳鼻咽喉   2076篇
儿科学   3952篇
妇产科学   2491篇
基础医学   16552篇
口腔科学   3847篇
临床医学   21444篇
内科学   22899篇
皮肤病学   2440篇
神经病学   8997篇
特种医学   6359篇
外国民族医学   10篇
外科学   18796篇
综合类   23166篇
现状与发展   13篇
一般理论   67篇
预防医学   20967篇
眼科学   2844篇
药学   15661篇
  120篇
中国医学   8520篇
肿瘤学   9226篇
  2023年   1733篇
  2022年   3293篇
  2021年   4614篇
  2020年   3955篇
  2019年   2815篇
  2018年   3531篇
  2017年   3729篇
  2016年   3313篇
  2015年   5003篇
  2014年   6285篇
  2013年   8595篇
  2012年   10888篇
  2011年   11493篇
  2010年   9213篇
  2009年   8508篇
  2008年   9476篇
  2007年   9510篇
  2006年   8677篇
  2005年   7577篇
  2004年   6109篇
  2003年   5346篇
  2002年   4818篇
  2001年   4489篇
  2000年   4015篇
  1999年   3082篇
  1998年   1455篇
  1997年   1281篇
  1996年   1262篇
  1995年   1100篇
  1994年   1058篇
  1993年   979篇
  1992年   2247篇
  1991年   2142篇
  1990年   2011篇
  1989年   1994篇
  1988年   1887篇
  1987年   1878篇
  1986年   1786篇
  1985年   1756篇
  1984年   1456篇
  1983年   1333篇
  1982年   899篇
  1981年   779篇
  1979年   1236篇
  1978年   896篇
  1977年   795篇
  1976年   746篇
  1974年   864篇
  1973年   755篇
  1972年   746篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的通过研究肺表面活性物质(PS)结合持续气道正压通气(CPAP)治疗新生儿呼吸窘迫综合征(NRDS)的治疗效果,进一步指导NRDS的临床治疗。方法选取于2017年4月-2018年10月间在本院收治的80例确诊为新生儿呼吸窘迫综合征的患儿作为研究对象,随机将患儿分为试验组和对照组,对照组给予持续气道正压通气治疗,试验组在对照组的基础上联合使用PS治疗。结果试验组对于呼吸窘迫缓解的有效率明显高于对照组,在气管插管内滴入PS治疗后试验组的血气情况明显优于对照组,且试验组患儿副作用发生率明显低于对照组,以上指标差异具有统计学意义,P <0.05。结论 PS结合CPAP在新生儿呼吸窘迫综合征的治疗中疗效很好。  相似文献   
2.
CONTEXT: Although the nonmedical use of stimulant drugs such as cocaine and methamphetamine is increasingly common in many rural areas of the United States, little is known about the health beliefs of people who use these drugs. PURPOSE: This research describes illicit stimulant drug users' views on health and health-related concepts that may affect their utilization of health care services. METHODS: A respondent-driven sampling plan was used to recruit 249 not-in-treatment, nonmedical stimulant drug users who were residing in 3 rural counties in west central Ohio. A structured questionnaire administered by trained interviewers was used to collect information on a range of topics, including current drug use, self-reported health status, perceived need for substance abuse treatment, and beliefs about health and health services. FINDINGS: Participants reported using a wide variety of drugs nonmedically, some by injection. Alcohol and marijuana were the most commonly used drugs in the 30 days prior to the interview. Powder cocaine was used by 72.3% of the sample, crack by 68.3%, and methamphetamine by 29.7%. Fair or poor health status was reported by 41.3% of the participants. Only 20.9% of the sample felt they needed drug abuse treatment. Less than one third of the sample reported that they would feel comfortable talking to a physician about their drug use, and 65.1% said they preferred taking care of their problems without getting professional help. CONCLUSIONS: Stimulant drug users in rural Ohio are involved with a range of substances and hold health beliefs that may impede health services utilization.  相似文献   
3.
4.
Choristomas, masses of normal tissues in aberrant locations, contain smooth muscle fibers and fibrous tissues. We describe the MR imaging features of two choristomas located in the internal auditory canals and arising from the facial and vestibulocochlear nerves. Both lesions enhanced with contrast material. In one case, enhancement was seen in the geniculate ganglion and greater superficial petrosal nerve. In the other, a medial component enhanced less than the lateral component did.  相似文献   
5.
Herpes zoster probably occurs more often than generally thought. Since it produces a radicular distribution of pain, it should be included in the differential diagnosis of radiculopathy. A case is presented in which evaluating the radicular low back pain before the characteristic rash appears was misleading. Careful history-taking concerning the exact nature of the pain and sensory changes is needed to differentiate between zoster and radiculopathy, if no rash is evident.  相似文献   
6.
. Neutrophil-mediated tissue damage has been implicated in the pathogenesis of diarrhoea-associated haemolytic uraemic syndrome (D+ HUS). This study evaluates priming and activation of the neutrophil oxidative burst in D+ HUS using chemiluminescent techniques. Peripheral blood neutrophils from 11 children with acute D+ HUS were examined. No difference was found in the oxidative burst of neutrophils from patients and controls. Serum elastase levels were measured in 8 patients and found to be significantly elevated. Although elastase results suggest neutrophil activation, chemiluminescence studies do not confirm this in the peripheral blood neutrophil. This does not support a significant role for circulating agents in priming and activating the peripheral blood neutrophil. Received August 17, 1995; received in revised form and accepted November 27, 1995  相似文献   
7.
OBJECTIVES: The incidence of bacterial microleakage, pulp inflammation and necrosis associated with dentine etching treatments prior to restoration are not known. Consequently, to resolve some of the controversy surrounding the effects and importance of vital dentine etching, the authors investigated these factors. METHODS: 110 standardised class V cavities were cut into buccal dentine, without exposing the pulp of teeth scheduled for extraction for orthodontic reasons. Cavities were either left unetched, or etched with the non-equivalent treatments of phosphoric acid gel for 60s or Ethylenediaminetetraacetic acid (EDTA) for 30s, prior to placement of composite resin. Teeth were collected and pulp responses were evaluated according to ISO guidelines, using pathohistomorphometric analysis and ANOVA statistics. RESULTS: Etching was found to be correlated to bacterial microleakage (p=0.0001) and tertiary dentine formation (p=0.0023). Bacterial microleakage was correlated to inflammatory activity (p=0.0001). The frequency of bacterial microleakage was: no etching (65%), EDTA (51%) and phosphoric acid (PA) (20%). SIGNIFICANCE: Vital dentine etching treatment is of extreme importance for the placement of RC to minimise bacterial microleakage. PA etching proved to be more effective at preventing bacterial microleakage than non-etching, and etching with EDTA.  相似文献   
8.
Maya families from Guatemala migrated to the United States in record numbers from the late 1970s to the early 1990s. Births to Maya immigrant women have created a sizable number of Maya American children. The height and sitting height of 5 to 12 years children (n = 431) were measured in 1999 and 2000. Leg length was estimated and the sitting height ratio was calculated. These data were compared with a sample of Maya children living in Guatemala measured in 1998 (n = 1,347). Maya American children are currently 11.54 cm taller and 6.83 cm longer‐legged, on average, than Maya children living in Guatemala. Consequently, the Maya Americans have a significantly lower average sitting height ratio (i.e., relatively longer legs in proportion to length of the head and trunk) than do the Maya in Guatemala. These results add support to the hypothesis that both the height and body proportions of human populations are sensitive indicators of the quality of the environment for growth. Am. J. Hum. Biol. 14:753–761, 2002. © 2002 Wiley‐Liss, Inc.  相似文献   
9.
10.
Horner's syndrome or oculosympathetic paralysis is not an uncommon finding in patients with head and neck neoplasms. While in most cases the syndrome is easily established at the bedside, it can be confirmed and topographically defined as a central, preganglionic, or postganglionic lesion through sequential pharmacologic testing. The importance of such localization lies in differentiating neoplasia vs. a benign condition as the cause of the syndrome. Such variants as congenital Horner's, an alternating Horner's, and a pseudo-Horner's syndrome are discussed in regard to their differential features.  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