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   32886篇
  免费   1985篇
  国内免费   99篇
耳鼻咽喉   254篇
儿科学   1106篇
妇产科学   925篇
基础医学   3874篇
口腔科学   393篇
临床医学   5981篇
内科学   5527篇
皮肤病学   344篇
神经病学   3146篇
特种医学   608篇
外国民族医学   1篇
外科学   3102篇
综合类   304篇
现状与发展   1篇
一般理论   50篇
预防医学   4575篇
眼科学   444篇
药学   2018篇
中国医学   34篇
肿瘤学   2283篇
  2023年   198篇
  2022年   329篇
  2021年   599篇
  2020年   431篇
  2019年   662篇
  2018年   823篇
  2017年   575篇
  2016年   643篇
  2015年   689篇
  2014年   1014篇
  2013年   1611篇
  2012年   2330篇
  2011年   2465篇
  2010年   1302篇
  2009年   1144篇
  2008年   2231篇
  2007年   2446篇
  2006年   2324篇
  2005年   2268篇
  2004年   2089篇
  2003年   2021篇
  2002年   1937篇
  2001年   280篇
  2000年   237篇
  1999年   346篇
  1998年   388篇
  1997年   323篇
  1996年   263篇
  1995年   292篇
  1994年   232篇
  1993年   231篇
  1992年   155篇
  1991年   175篇
  1990年   173篇
  1989年   143篇
  1988年   114篇
  1987年   110篇
  1986年   111篇
  1985年   128篇
  1984年   132篇
  1983年   141篇
  1982年   151篇
  1981年   142篇
  1980年   122篇
  1979年   66篇
  1978年   76篇
  1977年   69篇
  1976年   49篇
  1975年   36篇
  1974年   39篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
One of the most exciting developments in pediatric dermatology has been the use of the flashlamp-pumped, 585-nm, pulsed dye laser for treatment of vascular birthmarks. In many cases the results are miraculous. The increase in self-esteem and happiness of many children and adolescents has been overwhelming; for some, depression has been lifted, stuttering has ceased, social involvement has increased, and antidepressants have been discontinued. There are many success stories to tell.
Despite the remarkable effects of the pulsed dye laser and the medical and psychosocial indications for its use, the issue of pain control remains significant. We have no perfect outpatient pediatric anesthetic. Most methods carry either some risk or, if not hazardous, often are not very effective for controlling pain. Needless to say, a diversity of opinions exist on how to manage discomfort from this treatment modality. Therefore, we thought it would be useful to share the experiences and opinions of several dermatologists who have extensive experience with the pulsed dye laser.  相似文献   
62.
The spinal cord dorsal horn contains neural mechanisms which can greatly facilitate pain. We have recently shown that ‘illness’-inducing agents, such as intraperitoneally administered lipopolysaccharide (LPS; bacterial endotoxin), can produce prolonged hyperalgesia. This hyperalgesic state is mediated at the level of the spinal cord via activation of the NMDA-nitric oxide cascade. However, prolonged neuronal depolarization is required before such a cascade can occur. The present series of experiments were aimed at identifying spinal neurotransmitters which might be responsible for creating such a depolarized state. These studies show that LPS hyperalgesia is mediated at the level of the spinal cord by substance P, cholecystokinin and excitatory amino acids acting at non-NMDA sites. No apparent role for serotonin or kappa opiate receptors was found.  相似文献   
63.
64.
Immigrant workers are a rapidly growing segment of the U.S. work force, and these increasing numbers have resulted in a different ethnic mix in the work force than in previous decades. Immigrant workers are not a homogenous group, but are over-represented in low-paying occupations. Their diversity and vulnerability present distinct challenges for occupational health nurses. High-risk occupations in which a large proportion of immigrant workers are hired include agriculture, sweatshops, day laborers, and construction. Initiatives needed to improve the working conditions of this vulnerable population include improved surveillance and research, culturally competent care providers, improved health care access, advocacy, and changes in immigration and health policy.  相似文献   
65.
Factors associated with hypertension in Nigerian civil servants   总被引:3,自引:0,他引:3  
BACKGROUND. Study of hypertension in segments of West African populations in transition toward Westernization may lead to better understanding of the high risk for hypertension among Westernized blacks. METHODS. Five hundred fifty-nine urban civil servants, ages 25-54, were recruited from six ministries of Bendel State, Nigeria. Blood pressure, physical measurements, urinary protein and glucose, fasting blood glucose, and demographic data were collected at the workplace. Subjects were classified as senior staff (professionals or administrators) or junior staff (non-administrators). RESULTS. Among 172 male senior staff, the age-adjusted rate of hypertension (diastolic blood pressure > or = 90 mm Hg, systolic blood pressure > or = 140 mm Hg, or on an antihypertensive medication) was 43% and occurrence rose dramatically from 21 to 63% across age groups 25-34 to 45-54, respectively. Among 266 male junior staff, the age-adjusted rate of hypertension was 23%, and occurrence did not rise with age. Logistic regression showed that body mass index (kg/m2), age, alcohol drinking, and being senior staff were all independently related to hypertension in men. On the other hand, the age-adjusted rate of hypertension in 121 women was 20% and was significantly related only to body mass index. CONCLUSION. Male urban civil servants appeared to have a risk for hypertension similar to that of U.S. black males. Age, body mass index, alcohol drinking, and other unidentified factors related to higher socioeconomic status were strong determinants of hypertension in this population.  相似文献   
66.
Two different toxicity models were used to assess the relationship between the physicochemical properties of non-ionic surfactant vesicles (NSVs), and the safety of these vesicles for topical drug administration. The vesicles used in this study consisted of polyoxyethylene alkyl ethers (CnEOm) in which the number of C atoms (n) varied between 12 and 18 and the number of oxyethylene units (m) between 3 and 7. The physicochemical properties of the vesicles are described in terms of hydrophilic-lipophilic balance (HLB) values, and critical micelle concentrations (CMC), and the rigidity of the bilayers as determined by the gel-liquid transition temperatures and the cholesterol content of the bilayers. The first toxicity model, comprising the measurement of the ciliary beat frequency, is a tool to assess the safety of intranasally applied formulations. Studies using this ciliotoxicity model revealed that by increasing the length of the alkyl chain of the surfactant, a decrease in toxicity was observed. The opposite correlation was found if the length of the polyoxyethylene headgroup was increased. Furthermore, it was observed that gel-state vesicles produce less of an effect on the ciliary beat frequency than liquid state vesicles. The second toxicity model, comprising the determination of cell proliferation of human keratinocytes, is a method to assess skin irritancy. In contrast to the ciliotoxicity model the length of the polyoxyethylene headgroup and of the alkyl chains did not seem to have an effect on the safety of the vesicles.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
67.
The Central Arkansas Veterans Healthcare System (CAVHS) spends $1 million annually on occupational illnesses and injuries. To address the problem of injuries among hospital employees, a retrospective case-control study was conducted to examine select risk factors for work-related injuries (WRI) among CAVHS employees. Study methods included a review of employee health charts and computer and manual databases from 1997 to 2002 (N = 2,050). The researchers found that WRI increased with age; WRI occurred more often in women than in men; WRI was greater among maintenance and custodial staff compared to direct caregivers, and less among clerical staff; WRI occurred less often in part-time than full-time staff; and WRI increased with increasing body mass index. Developing standards, guidelines, and policies for preplacement screening, preventive measures, training, and education may help to minimize WRI and associated costs.  相似文献   
68.
69.
This report describes the outcomes of 28 children who had severe head injuries between 13–18 years of age. All were unconscious at least 24 hours and have been followed at least 2 years after injury. At present, their ages range from 18 to 27 years. Their educational achievements, social activities, marital status, functional independence, and employment at follow-up are described.  相似文献   
70.
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