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   6132篇
  免费   355篇
  国内免费   12篇
耳鼻咽喉   70篇
儿科学   124篇
妇产科学   124篇
基础医学   835篇
口腔科学   63篇
临床医学   625篇
内科学   1069篇
皮肤病学   91篇
神经病学   874篇
特种医学   212篇
外国民族医学   4篇
外科学   669篇
综合类   57篇
一般理论   7篇
预防医学   522篇
眼科学   318篇
药学   466篇
中国医学   14篇
肿瘤学   355篇
  2023年   47篇
  2022年   84篇
  2021年   141篇
  2020年   81篇
  2019年   107篇
  2018年   146篇
  2017年   116篇
  2016年   138篇
  2015年   137篇
  2014年   191篇
  2013年   253篇
  2012年   383篇
  2011年   401篇
  2010年   248篇
  2009年   200篇
  2008年   361篇
  2007年   326篇
  2006年   302篇
  2005年   275篇
  2004年   260篇
  2003年   292篇
  2002年   222篇
  2001年   116篇
  2000年   143篇
  1999年   113篇
  1998年   60篇
  1997年   60篇
  1996年   36篇
  1995年   32篇
  1994年   37篇
  1992年   83篇
  1991年   56篇
  1990年   61篇
  1989年   55篇
  1988年   54篇
  1987年   57篇
  1986年   70篇
  1985年   57篇
  1984年   47篇
  1983年   43篇
  1982年   22篇
  1980年   21篇
  1979年   48篇
  1978年   24篇
  1975年   23篇
  1973年   25篇
  1938年   21篇
  1935年   22篇
  1933年   26篇
  1932年   20篇
排序方式: 共有6499条查询结果,搜索用时 15 毫秒
991.

Objective

To explore Appalachian women's perceptions of trust and distrust of healthcare providers and the medical care system as they relate to views about cervical cancer and screening.

Methods

Thirty-six Ohio Appalachia female residents participated in community focus groups conducted by trained facilitators. Discussion topics included factors related to cervical cancer, and the issues of trust and distrust in medical care. The tape-recorded focus groups were transcribed and analyzed to identify salient themes.

Results

Five themes emerged related to trust in healthcare. Patient-centered communication and encouragement from a healthcare provider led women to trust their physicians and the medical care system. In contrast, lack of patient-centered communication by providers and perceptions of poor quality of care led to distrust. Physician gender concordance also contributed to trust as women reported trust of female physicians and distrust of male physicians; trust in male physicians was reported to be increased by the presence of a female nurse.

Conclusions

Important factors associated with trust and distrust of providers and the medical care system may impact health-seeking behaviors among underserved women.

Practice implications

Opportunities to improve patient-centered communication around the issues of prevention and cervical cancer screening (such as providing patient-focused information about access to appropriate screening tests) could be used to improve patient care and build patients’ trust.  相似文献   
992.
Protein lysine methylation is one of the most widespread post-translational modifications in the nuclei of eukaryotic cells. Methylated lysines on histones and nonhistone proteins promote the formation of protein complexes that control gene expression and DNA replication and repair. In the cytoplasm, however, the role of lysine methylation in protein complex formation is not well established. Here we report that the cytoplasmic protein chaperone Hsp90 is methylated by the lysine methyltransferase Smyd2 in various cell types. In muscle, Hsp90 methylation contributes to the formation of a protein complex containing Smyd2, Hsp90, and the sarcomeric protein titin. Deficiency in Smyd2 results in the loss of Hsp90 methylation, impaired titin stability, and altered muscle function. Collectively, our data reveal a cytoplasmic protein network that employs lysine methylation for the maintenance and function of skeletal muscle.  相似文献   
993.
994.
Purpose: To pilot test the newly developed multidisciplinary group rehabilitation programme Visually Impaired elderly Persons Participating (VIPP). Method: A single group pretest-posttest design pilot study included 29 visually impaired persons (≥55 years). The intervention (20 weekly meetings) consisted of four components (practical training; education, social interaction, counselling and training of problem-solving skills; individual and group goal setting; home-based exercise programme). Participation was assessed with the Utrecht Scale for Evaluation of Rehabilitation-Participation (USER-P) and the Impact on Participation and Autonomy (IPA) questionnaire at baseline, immediately and 6 months after the intervention. Results: At scale level, no statistical significant changes over time were found whereas the effect size indicated small effects for restrictions and satisfaction with participation, and a medium effect for autonomy outdoors. At item level, improvements tended to occur in frequency of housekeeping, in restrictions in housekeeping and outdoor activities and in satisfaction with the partner relationship. Satisfaction with leisure indoors and autonomy regarding using leisure time tended to increase as well. Conclusions: The tentative conclusion of this small-scale pilot study is that the VIPP programme modestly benefits perceived restrictions in participation, satisfaction with participation and autonomy outdoors of the visually impaired elderly. These preliminary findings warrant further investigation. [Box: see text].  相似文献   
995.
In vitro gut fermentation systems are relevant tools to study health benefits of foodstuffs. Most of them are commonly used to investigate the degradation of nutrients or the development of gut flora. Using these models, strong cytotoxic effects of the resulting samples on cultured cells were observed. Hence, the aim of the present study was to develop a modified in vitro fermentation model that simulates the whole digestive tract and generates fermented samples that are suitable for testing in cell culture experiments. Wholemeal wheat flour (wwf) was digested and fermented in vitro with a fermentation model using different ox gall concentrations (41·6 and 0·6?g/l). The resulting fermentation supernatants (fs) were characterised for metabolites and biological effects in HT29 cells. The fermentation of wwf increased chemopreventive SCFA and decreased carcinogenic deoxycholic acid (DCA). The strong cytotoxic effects of the fs, which were partly due to cholic acid and DCA, were diminished by lowering the ox gall concentration, allowing the use of the samples in cell culture experiments. In conclusion, an in vitro digestion model, which can be used to study the effects of foodstuffs on chemoprevention and gut health in colon cells, is introduced and its physiological relevance is demonstrated.  相似文献   
996.
Bread is a major contributor to sodium intake in many countries. Reducing the salt (NaCl) content in bread might be an effective way to reduce overall sodium intake. The objectives of this study were to examine the effects of gradually lowering the salt content in brown bread, with and without flavor compensation (KCl and yeast extract), on bread consumption and sodium intake compensation by choice of sandwich fillings. A total of 116 participants (age: 21 ± 3 y; BMI: 22 ± 2 kg/m2) consumed a buffet-style breakfast on weekdays for 4 wk. Participants received either regular bread (control group: n = 39), bread whose salt content was gradually lowered each week by 0, 31, 52, and 67% (reduced group: n = 38), or bread whose salt content was also gradually lowered each week but which was also flavor compensated (compensated group: n = 39). A reduction of up to 52% of salt in bread did not lead to lower consumption of bread compared to the control (P = 0.57), whereas less bread was consumed when salt was reduced by 67% (P = 0.006). When bread was flavor compensated, however, a reduction of 67% did not lead to lower consumption (P = 0.69). Salt reduction in bread (with and without flavor compensation) did not induce sodium intake compensation (P = 0.31). In conclusion, a salt reduction of up to 52% in bread or even up to 67% in flavor-compensated bread neither affected bread consumption nor choice of sandwich fillings.  相似文献   
997.
Antiphospholipid syndrome (APS) had been previously diagnosed in three pregnant women aged 32, 27 and 36 years, respectively. All three of them were using low-molecular weight heparin for the prevention of thromboembolic complications. The first two women were admitted because of foetal growth retardation. In the first patient, either HELLP syndrome or exacerbation of APS was suspected. A caesarean section was performed due to foetal distress. The patient's condition deteriorated further postoperatively. Multiple infarctions in liver and placenta were identified. Catastrophic antiphospholipid syndrome (CAPS) was diagnosed. Despite intensive medical treatment including anticoagulation the patient died of massive pulmonary embolism. The second patient suffered from thrombocytopaenia, disturbances in hepatic function and epigastric pain. CAPS was diagnosed. The condition improved after treatment with glucocorticoids, but because of a poor foetal prognosis, delivery was induced and a lifeless son was born. The third woman was admitted due to pyelonephritis. Shortly thereafter, symptoms of HELLP syndrome developed and she was administered glucocorticoids. Hepatic infarcts and petechiae developed, indicating CAPS. Delivery was induced and a girl was born. Glucocorticoid treatment was resumed and combined with immunoglobulins and plasmapheresis. The patient recovered and was discharged together with her daughter. CAPS is a life-threatening variation of APS. It is characterised by multiple thromboses and rapidly progressive multi-organ failure. Mortality is high, but seems to diminish with treatment by immunosuppressive therapy. In pregnancy, clinical signs of CAPS are similar to those of HELLP syndrome. Since the treatment for HELLP syndrome is different from CAPS, a correct diagnosis is essential. Because of the rarity of this condition in combination with high rates of perinatal and maternal mortality, care for pregnant patients with APS should be centralised in academic centres and close cooperation between obstetricians and internal medicine is necessary.  相似文献   
998.
With the current global influenza vaccine production capacity the large demand for vaccines in case of a pandemic can only be fulfilled when antigen dose sparing strategies are employed. Here we used a murine challenge model to evaluate the potential of GPI-0100, a semi-synthetic saponin derivative, to serve as a dose-sparing adjuvant for influenza subunit vaccine. Balb/c mice were immunized with different doses of A/PR8 (H1N1) subunit antigen alone or in combination with varying doses of GPI-0100. The addition of GPI-0100 significantly stimulated antibody and cellular immune responses, especially of the Th1 phenotype. Furthermore, virus titers detected in the lungs of mice challenged one week after the second immunization were significantly reduced among the animals that received GPI-0100-adjuvanted vaccines. Remarkably, adjuvantation of subunit vaccine with GPI-0100 allowed a 25-fold reduction in hemagglutinin dose without compromising the protective potential of the vaccine.  相似文献   
999.
Modification of lifestyle habits is a key preventive strategy for many diseases. The role of lifestyle for the onset of headache in general and for specific headache types, such as migraine and tension-type headache (TTH), has been discussed for many years. Most results, however, were inconsistent and data on the association between lifestyle factors and probable headache forms are completely lacking. We evaluated the cross-sectional association between different lifestyle factors and headache subtypes using data from three different German cohorts. Information was assessed by standardized face-to-face interviews. Lifestyle factors included alcohol consumption, smoking status, physical activity and body mass index. According to the 2004 diagnostic criteria, we distinguished the following headache types: migraine, TTH and their probable forms. Regional variations of lifestyle factors were observed. In the age- and gender-adjusted logistic regression models, none of the lifestyle factors was statistically significant associated with migraine, TTH, and their probable headache forms. In addition, we found no association between headache subtypes and the health index representing the sum of individual lifestyle factors. The lifestyle factors such as alcohol consumption, smoking, physical activity and overweight seem to be unrelated to migraine and TTH prevalence. For a judgement on their role in the onset of new or first attacks of migraine or TTH (incident cases), prospective cohort studies are required.  相似文献   
1000.

Introduction  

Controversy exists about the benefit of screening for prevention of methicillin-resistant Staphylococcus aureus (MRSA) in intensive care units (ICUs) and recent studies have shown conflicting results. The aim of this observational study was to describe and evaluate the association between MRSA incidence densities (IDs) and screening and control measures in ICUs participating in the German Nosocomial Infection Surveillance System.  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