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   2028篇
  免费   146篇
  国内免费   1篇
耳鼻咽喉   16篇
儿科学   113篇
妇产科学   47篇
基础医学   342篇
口腔科学   16篇
临床医学   173篇
内科学   436篇
皮肤病学   51篇
神经病学   286篇
特种医学   52篇
外科学   137篇
综合类   4篇
一般理论   1篇
预防医学   219篇
眼科学   43篇
药学   93篇
中国医学   3篇
肿瘤学   143篇
  2024年   2篇
  2023年   29篇
  2022年   49篇
  2021年   79篇
  2020年   48篇
  2019年   71篇
  2018年   86篇
  2017年   70篇
  2016年   80篇
  2015年   70篇
  2014年   102篇
  2013年   135篇
  2012年   207篇
  2011年   184篇
  2010年   104篇
  2009年   89篇
  2008年   124篇
  2007年   141篇
  2006年   97篇
  2005年   112篇
  2004年   80篇
  2003年   77篇
  2002年   68篇
  2001年   5篇
  2000年   6篇
  1999年   10篇
  1998年   5篇
  1997年   7篇
  1996年   6篇
  1995年   6篇
  1994年   3篇
  1993年   3篇
  1992年   3篇
  1991年   3篇
  1989年   1篇
  1988年   3篇
  1987年   2篇
  1986年   2篇
  1985年   1篇
  1984年   3篇
  1980年   1篇
  1977年   1篇
排序方式: 共有2175条查询结果,搜索用时 31 毫秒
91.
92.
Summary Forty three patients, admitted to the department of Neurological Surgery for management of central nervous system tumours, were studied pre-operatively for serum myelin basic protein immunoreactivity as a marker of central nervous system lesion and for circulating immunoglobulins and complement (C3) levels. Myelin basic protein concentration did not appear to correlate with tumour type or grade. Serum immunoglobulin levels were found to be within the normal range but the mean IgM level was significantly higher in the glioma group when compared with meningiomas.  相似文献   
93.
Iron deficiency anaemia (IDA) has a large impact on productivity, mental performance, child growth, immunity and pregnancy outcome. In Indonesia, 50 to 70 million people (25–30% of the population) suffer from IDA. In 1995, the prevalence among pregnant women, underfives and female workers was 50.9%, 40.5% and 30%, respectively. Because nutrition and health are essential to human development, Indonesia has identified their improvement, including reducing IDA, a high priority. Several programs are implemented to control IDA. Iron supplementation for pregnant women started in 1974 and currently provides 60% with 90 tablets. Because infants and children cannot meet their iron requirements through diet alone, unless it contains fortified foods, distribution of iron-rich syrup to underfives was started in less developed villages in eastern Indonesia in 1996. Since 1996, factories should supplement their female workers with iron supplements once per week, 16 weeks per year, in order to increase their well-being and productivity. Other groups, such as female adolescents, school children and non-pregnant women are currently targeted through special projects and through IEC, using dietary guidelines, directed at a larger audience. With the increase in economic growth, self-purchasing of supplements and food fortification become more viable strategies. Producers of some brands of noodles and weaning foods are currently fortifying their products, while producers of “jamu” (traditional herb drinks) are increasing the content of enhancers of iron absorption. Reducing IDA in Indonesia is the goal of the Department of Health in collaboration with other departments, non-governmental organisations, international agencies, and the private sector.  相似文献   
94.
The PCR-ELISA represents a promising advance for diagnosis of visceral leishmaniasis (VL) in blood samples. However, the method has been validated mostly with HIV-positive patients who are known to have high levels of parasitaemia. We developed a new PCR-ELISA assay for specific detection of Leishmania in patients' blood and validated it in Nepalese subjects with clinically suspected VL, almost all of whom were HIV-negative. For blood samples, PCR-ELISA was more sensitive (83.9%) than conventional PCR (73.2%), and demonstrated 100% and 87.2% specificity when using healthy controls who had never travelled to a VL-endemic area and controls from a VL-endemic area as references, respectively. We have demonstrated the ability of PCR-ELISA to detect parasites in blood of HIV-negative patients. The method could be used for epidemiological as well as clinical purposes, as it reduces the need for traumatic bone marrow sampling and risky spleen aspiration.  相似文献   
95.
An important determinant of the clinical applicability and value of antimicrobial photodynamic inactivation (PDI) is the cytotoxicity of the treatment to human cells. We evaluated the in vitro cytotoxicity of PDI to human dermal fibroblasts using 5-phenyl-10,15,20-tris(N-methyl-4-pyridyl)porphyrin chloride (TriP[4]) as the photosensitiser. The fibroblasts were exposed to a PDI regime that is known to be sufficient for the inactivation of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans [1]. The PDI experiments were carried out in phosphate-buffered saline (PBS) and in 6.25%, 12.5%, 25% and 50% fetal calf serum (FCS)/PBS suspensions. Cell viability subsequent to exposure was evaluated after 0 h, 6 h and 18 h using the methylthiazoletetrazolium (MTT) assay and compared to pretreatment values. At a TriP[4] concentration previously demonstrated to induce a 5log10-unit reduction in a viable count for S. aureus, 79% of the fibroblasts were photo-inactivated. Increasing the FCS concentration in the medium protected the fibroblasts against PDI. Based on our in vitro results, we propose that in vivo PDI of S. aureus holds potential; however, PDI of P. aeruginosa and C. albicans will probably require such a strong PDI regime that it will induce substantial damage to fibroblasts.  相似文献   
96.
Indonesia's economic crisis of late 1990s lowered consumption of micronutrient-rich foods, which increased the prevalence of micronutrient deficiencies, including anemia. As a postcrisis response, 5 nongovernmental organizations (NGOs) implemented Food for Work (FFW) programs to protect food consumption levels and nutritional status by providing rice, sometimes combined with oil and/or pinto beans. An independent evaluation assessed the effect of the FFW programs on nutrition outcomes, particularly anemia. A quasi-experimental design was used in which 1500 beneficiary and 1500 control households were randomly selected and followed in each of 3 urban and 2 rural sites. Baseline data were collected before program implementation and subsequently at approximately 6-mo intervals for 2.5 y. The poor were found to be appropriately targeted, and program participation ranged from 4 to 18 mo. The proportion of households with debts ranged from 32 to 70%; although it was higher among beneficiaries than controls, it increased among controls, but not beneficiaries. However, only among urban poor mothers in Surabaya were the odds of anemia at endline lower when participating in the FFW program (0.60, 95%CI [0.40-0.89]). Other risk factors for anemia in mothers and children included nutritional status (anemia at baseline, low BMI, receipt of vitamin A capsule, child age) and socioeconomic status (maternal education, having official residency in the area, income level). Thus, postcrisis FFW programs had limited effect on anemia, the main identified nutritional problem. Closer attention is required to the potential for affecting nutritional outcomes through FFW, including food aid quality and quantity and complementary nonfood interventions. Micronutrient deficiencies should be addressed directly via supplements and fortified foods.  相似文献   
97.
Psychosocial Predictors of Success following Bariatric Surgery   总被引:3,自引:3,他引:0  
Background: Bariatric surgery is the treatment of choice for morbid obesity, but it does not lead to equal results in every patient. In addition to surgery, a number of non-surgical and psychological factors may influence patients' ability to adjust to the postoperative condition. Understanding the relationship between potential predictive variables and success after bariatric surgery will enable better patient selection, and the development of interventions to improve outcome. Methods: A systematic literature search identified relevant variables, such as demography, preoperative weight, motivation, expectations, eating behavior, psychological functioning, personality, and psychiatric disorders, which may have predictive value for success after bariatric surgery. Results: Greater success following bariatric surgery appears to occur in patients who are young and female, and have a high self-esteem, good mental health, a satisfactory marriage, and high socio-economic status, who are self-critical and cope in a direct and active way, are not too obese, were obese before the age of 18, suffer from and are concerned about their obesity, have realistic expectations and undisturbed eating behaviors. Occasionally, these variables may have poor or no predictive value. Although reliable predictors are lacking, most treatment teams propose their own exclusion criteria. Conclusion: The existing literature about potential predictors of success after bariatric surgery is far from conclusive; it is still uncertain which factors can predict success. Even where psychosocial functioning does not predict outcome, it is important to identify patients' characteristics which may be linked to their prognosis and to provide necessary pre- and postoperative psychosocial interventions.  相似文献   
98.
Data indicate that bacterial products in combination with other antenatal or postnatal exposures increase the risk of perinatal brain injury. We have previously shown that administration of lipopolysaccharide (LPS) 4 h before hypoxia-ischemia (HI) increases brain injury in 7-d-old rats. The mechanisms behind such sensitization are unclear, but contrasts against a preconditioning effect of LPS given 1-3 d before ischemia in adult animals. To investigate how the effects of LPS depend on the time interval between administration and HI in the developing brain, we evaluated the effect of varying time interval (2-72 h) between LPS and HI, the duration of HI (20 or 50 min), and age of the rat pups (postnatal d 4 or 7). Outcome was assessed by brain injury scoring of specific regions. We found that LPS reduced brain injury (by 78%) when administered 24 h before 50 min of HI. However, when LPS was administered 6 h before either 20 or 50 min of HI, brain injury was increased by 2026% and 137%, respectively. Even LPS given 72 h before HI increased injury, both when LPS was administered at postnatal d 4 (by 446%) and 7 (by 77%). In conclusion, LPS enhanced vulnerability in the developing brain both in the acute (4-6 h) and the chronic (72 h) phase after administration, whereas an intermediate interval between LPS and HI had the opposite effect. The long-term sensitizing effect of LPS has not been previously described.  相似文献   
99.
100.
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