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   3658篇
  免费   188篇
  国内免费   10篇
耳鼻咽喉   27篇
儿科学   86篇
妇产科学   71篇
基础医学   557篇
口腔科学   146篇
临床医学   283篇
内科学   795篇
皮肤病学   41篇
神经病学   379篇
特种医学   93篇
外科学   376篇
综合类   9篇
一般理论   1篇
预防医学   282篇
眼科学   123篇
药学   277篇
中国医学   25篇
肿瘤学   285篇
  2024年   3篇
  2023年   24篇
  2022年   51篇
  2021年   75篇
  2020年   62篇
  2019年   80篇
  2018年   95篇
  2017年   77篇
  2016年   94篇
  2015年   90篇
  2014年   146篇
  2013年   186篇
  2012年   290篇
  2011年   315篇
  2010年   171篇
  2009年   136篇
  2008年   220篇
  2007年   234篇
  2006年   248篇
  2005年   237篇
  2004年   231篇
  2003年   199篇
  2002年   168篇
  2001年   41篇
  2000年   31篇
  1999年   35篇
  1998年   25篇
  1997年   32篇
  1996年   16篇
  1995年   18篇
  1994年   22篇
  1993年   15篇
  1992年   27篇
  1991年   23篇
  1990年   25篇
  1989年   11篇
  1988年   7篇
  1987年   16篇
  1986年   11篇
  1985年   7篇
  1984年   12篇
  1983年   8篇
  1982年   6篇
  1981年   6篇
  1979年   5篇
  1978年   3篇
  1977年   3篇
  1976年   3篇
  1974年   3篇
  1966年   3篇
排序方式: 共有3856条查询结果,搜索用时 10 毫秒
991.
OBJECTIVE: To get some additional insight on the mechanisms of the effect of salt intake on body weight. DESIGN AND METHODS: Rats were fed a low (LSD), normal (NSD), or high (HSD) salt diet. In a first set, body weight, tail-cuff blood pressure, fasting plasma thyroid-stimulating hormone, triiodothyronine, L-thyroxine, glucose, insulin, and angiotensin II were measured. Angiotensin II content was determined in white and brown adipose tissues. Uncoupling protein 1 expression was measured in brown adipose tissue. In a second set, body weight, food intake, energy balance, and plasma leptin were determined. In a third set of rats, motor activity and body weight were evaluated. RESULTS: Blood pressure increased on HSD. Body weight was similar among groups at weaning, but during adulthood it was lower on HSD and higher on LSD. Food intake, L-thyroxine concentration, uncoupling protein 1 expression and energy expenditure were higher in HSD rats, while non-fasting leptin concentration was lower in these groups compared to NSD and LSD animals. Plasma thyroid-stimulating hormone decreased on both HSD and LSD while plasma glucose and insulin were elevated only on LSD. A decrease in plasma angiotensin II was observed in HSD rats. On LSD, an increase in brown adipose tissue angiotensin II content was associated to decreased uncoupling protein 1 expression and energy expenditure. In this group, a low angiotensin II content in white adipose tissue was also found. Motor activity was not influenced by the dietary salt content. CONCLUSIONS: Chronic alteration in salt intake is associated with changes in body weight, food intake, hormonal profile, and energy expenditure and tissue angiotensin II content.  相似文献   
992.
Considerable expectations to prevent hepatocellular carcinoma (HCC) appearance are connecte with the use of Inferon alpha (IFN alpha) in antiviral treatment of the hepatitis B or C. Several studies have reported that the incidence of HCC may b reduced after IFN therapy in patients with chronic B or C hepatitis although its real preventive efffect is still debatable. The purpose of the studies from our laboratory was to evaluate the action of IFN alpha2b on preneoplastic foci in a two-phase model of preneoplasia development in rat. We demonstrated that IFN-alpha2b administration significantly decreased both number and volume percentage of altered hepatitis foci (AHF). This reduction could be explained by an induced programmed cell death in the foci. This apoptotic effect of IFN-alpha2b on preneoplastic liver foci was mediated by the production of endogenous TGFbeta1 from hepatocytes acting by a paracrine/autocrine way. Further studies confirmed that these results were a consequence of the perturbation of the redox status induced by the IFN-2b. In conclusion, IFN-alpha2b couldenhance the proapoptotic effects of TGFbeta1, in early stages of hepatocarcinogenesis, which could be highly beneficial in cancer therapy.  相似文献   
993.

Objective

To identify coping strategies used by patients with systemic lupus erythematosus (SLE), and to assess the influence of main clinical and coping variables on health‐related quality of life (HRQOL).

Methods

We administered the Coping Orientation to Problems Experienced and the Short Form 36 questionnaire to a group of 144 patients with SLE and a group of 129 healthy controls. At the time of the psychological assessment, all patients underwent a complete clinical and laboratory evaluation.

Results

SLE patients had higher scores in acceptance (P < 0.001) and turning to religion (P = 0.05) and lower scores in planning (P = 0.001), suppression of competing activities (P = 0.010), restraint coping (P = 0.031), focusing on and venting of emotion (P = 0.009), and strategies focused on problem (P = 0.012) compared with controls. By means of linear regression analysis, HRQOL in SLE patients seemed to be influenced positively by restraint coping and positive reinterpretation and growth, and negatively by focusing on and venting of emotion, behavioral disengagement, and mental disengagement. When clinical variables were added to the multivariate analysis for coping strategies, more significant regression models that included joint pain were obtained.

Conclusion

In facing stressful situations, patients with SLE tend to use coping skills that are generally adopted for events perceived as nonmodifiable. Strategies that show a passive attitude and joint pain seem to impair these patients' HRQOL.
  相似文献   
994.
Posttraumatic shame and guilt are important dimensions of posttraumatic syndromes, including simple and complex post-traumatic stress disorder (PTSD). The concepts of posttraumatic shame and guilt have received little theoretical or empirical investigation in the field of traumatology. It is proposed that there are acute and prolonged states of posttraumatic shame and guilt that can be compared in their consequences across eight psychosocial dimensions: (a) self-attribution processes, (b) emotional states and capacity for affect regulation, (c) appraisal and interpretation of actions, (d) the impact of states of shame and guilt on personal identity, (e) suicidality, (f) defensive patterns, (g) proneness to psychopathology and PTSD, and (h) the dimensions of the self-structure adversely affected by states of posttraumatic shame and guilt. The experience of posttraumatic states of shame and guilt are associated with compounded affective processes in PTSD, depression, and substance use disorders.  相似文献   
995.
The aims of this study were to estimate the occurrence of hypophosphatemia and to identify potential risk factors and outcome measures associated with this disturbance in children admitted to a pediatric intensive care unit. Data concerning 42 children admitted consecutively to 1 pediatric intensive care unit over a 1-year period were examined. Serum phosphorus levels were measured on the third day of admission, where levels below 3.8 mg/dL were considered indicative of hypophosphatemia. Hypophosphatemia was found in 32 children (76%), and there was a significant association between this disturbance and malnutrition (P = .04). Of the potential risk factors such as sepsis, diuretic/steroid therapy, starvation (over 3 days), and Pediatric Index of Mortality, none discriminated for hypophosphatemia. There were no associations between hypophosphatemia and mortality, length of stay in the pediatric intensive care unit, or time on mechanical lung ventilation. Hypophosphatemia was a common finding in critically ill children and was associated with malnutrition.  相似文献   
996.
997.
998.
999.
For many years, traditional electrodiagnosis has been the main methodology for studying the radiculopathies. However, the current literature lacks full validation studies. We studied a population of 51 subjects with disc hernia, comparing their surgical reports with data obtained by electrodiagnostic testing. At the same time, we studied a population of 18 healthy subjects in order to obtain normative data. The analysis of the data allowed us to identify the cut-off point for positivity vs negativity of electrodiagnostic testing in the population of healthy subjects and to verify the association between electrodiagnostic variables (rheobase and chronaxie indices, and shortened strength-duration curves) and the surgical findings. The statistical analysis showed an optimal correspondence between the surgical report and the electrodiagnostic test. This methodology may be integrated with the other tests in the diagnostic phase and used in the monitoring of rehabilitative treatment.  相似文献   
1000.
Thyroid cancer incidence is rapidly increasing. Papillary Thyroid Carcinoma (PTC), the most frequent hystotype, usually displays good prognosis, but no effective therapeutic options are available for the fraction of progressive PTC patients. BRAF and RET/PTC are the most frequent driving genetic lesions identified in PTC. We developed two complementary in vitro models based on RET/PTC1 oncogene, starting from the hypothesis that miRNAs modulated by a driving PTC-oncogene are likely to have a role in thyroid neoplastic processes. Through this strategy, we identified a panel of deregulated miRNAs. Among these we focused on miR-199a-3p and showed its under-expression in PTC specimens and cell lines. We demonstrated that miR-199a-3p restoration in PTC cells reduces MET and mTOR protein levels, impairs migration and proliferation and, more interesting, induces lethality through an unusual form of cell death similar to methuosis, caused by macropinocytosis dysregulation. Silencing MET or mTOR, both involved in survival pathways, does not recapitulate miR-199a-3p-induced cell lethality, thus suggesting that the cooperative regulation of multiple gene targets is necessary. Integrated analysis of miR-199a-3p targets unveils interesting networks including HGF and macropinocytosis pathways. Overall our results indicate miR-199a-3p as a tumor suppressor miRNA in PTC.  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