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   442篇
  免费   44篇
  国内免费   5篇
耳鼻咽喉   18篇
儿科学   9篇
妇产科学   4篇
基础医学   77篇
口腔科学   3篇
临床医学   44篇
内科学   96篇
皮肤病学   7篇
神经病学   29篇
特种医学   51篇
外科学   43篇
综合类   13篇
一般理论   1篇
预防医学   33篇
眼科学   3篇
药学   18篇
肿瘤学   42篇
  2021年   7篇
  2020年   7篇
  2019年   6篇
  2018年   11篇
  2017年   5篇
  2016年   7篇
  2015年   11篇
  2014年   14篇
  2013年   14篇
  2012年   17篇
  2011年   16篇
  2010年   13篇
  2009年   5篇
  2008年   30篇
  2007年   14篇
  2006年   12篇
  2005年   26篇
  2004年   18篇
  2003年   14篇
  2002年   22篇
  2001年   13篇
  2000年   14篇
  1999年   7篇
  1998年   13篇
  1997年   13篇
  1996年   18篇
  1995年   8篇
  1994年   7篇
  1993年   9篇
  1992年   8篇
  1991年   7篇
  1990年   11篇
  1988年   4篇
  1987年   6篇
  1986年   5篇
  1985年   5篇
  1982年   5篇
  1981年   3篇
  1980年   5篇
  1979年   3篇
  1978年   4篇
  1977年   9篇
  1976年   7篇
  1975年   5篇
  1973年   3篇
  1972年   4篇
  1969年   4篇
  1965年   2篇
  1934年   2篇
  1933年   2篇
排序方式: 共有491条查询结果,搜索用时 15 毫秒
91.
Background External anogenital warts (EGWs) are non‐malignant skin tumours caused by human papillomavirus. They are one of the fastest growing sexually transmitted diseases. Current treatments are unsatisfactory. Green tea sinecatechin Polyphenon E ointment is a botanical extract from green tea leaves exhibiting anti‐oxidant, anti‐viral and anti‐tumour properties. Objective The aim of this study was to integrate valid information and provide basis for rational decision making regarding efficacy and safety of green tea extracts in the treatment of EGWs. Methods A systematic search in electronic databases was conducted using specific key terms. Main search was performed independently by two reviewers. The accumulated relevant literature was subsequently systematically reviewed and a meta‐analysis was conducted. Results Three randomized, double‐blind, placebo‐controlled studies evaluating efficacy and safety of Polyphenon E 15% and 10% in the treatment of warts were included in the systematic review and meta‐analysis. A total of 660 men and 587 women were enrolled. Regarding primary outcome, both Polyphenon E 15% and 10% demonstrated significantly higher likelihood of complete clearance of baseline and baseline and new warts compared with controls. No significant heterogeneity was detected. Recurrence rates were very low. Commonest local skin sign was erythema and local skin symptom was itching. Conclusions Efficacy of Polyphenon 15% and 10%, at least for the primary endpoint, is clearly indicated. Polyphenon E treatment exhibits very low recurrence rates and appears to have a rather favourable safety and tolerability profile. Recommendations for future studies should include evaluation of the efficacy of green tea catechins in the treatment of internal anogenital warts and direct comparison with its principal comparator, imiquimod.  相似文献   
92.
Background Atopic dermatitis (AD) is a chronic inflammatory skin disease with increasing frequency over the last decades, especially in adults. Cytokines orchestrate atopic skin inflammation. Objectives The aim of this study was to compare serum levels of cytokines in adult patients with acute AD (AD1) with other groups of AD patients and controls and investigate the possible association between such cytokines and disease severity. Methods We measured cytokine levels using flow cytometry in 21 adult patients with acute AD, 12 adults with chronic AD, 10 children with acute AD and 10 healthy adults. Results Flow cytometry analysis of cytokines revealed that interleukin 10 (IL‐10), IL‐6, interferon γ (IFN‐γ) and IL‐4 levels were significantly decreased in AD1 group compared with controls, whereas IL‐2 and tumour necrosis factor (TNF) did not differ. Comparison of AD1 group with adults chronic phase group showed that IgE, eosinophil and IL‐2 levels remained unaltered, whereas IL‐10, IL‐6, IFN‐γ, IL‐4 and TNF were significantly decreased. SCORAD and IgE levels were significantly increased, IL‐10, IL‐6 and IFN‐γ were decreased and TNF, IL‐2, IL‐4 and eosinophil levels remained unchanged in AD1 group compared with children acute phase group. Within AD1 group correlation analysis revealed that IgE and TNF levels were significantly associated with AD severity. Coefficient of determination analysis revealed that TNF and IgE levels could explain 49.14% and 35.28% of the variance of SCORAD. Conclusions These data indicate that serum IgE and TNF levels correlate with AD severity and that serum cytokines are downregulated in AD1 group. Further studies are clearly needed to elucidate cytokines’ role in adults with AD .  相似文献   
93.
BACKGROUND: CD5 B cells and the natural autoantibodies they produce play a role in antigen presentation, tolerance induction, and maintenance of an idiotypic immune network. The effects of transfusion on autoantibodies and peripheral blood CD5 B cells were studied. STUDY DESIGN AND METHODS: Eight previously transfused patients with sickle cell anemia and five patients who underwent orthopedic surgical procedures with transfusion were enrolled in the study. Patients in both groups received 1 to 2 units of allogeneic packed red cells. Ten untransfused healthy adults and five patients who underwent orthopedic surgery without transfusion were enrolled as controls. Peripheral blood CD5 B cells, serum levels of IgM, antinuclear antibodies, rheumatoid factor, and anticardiolipin IgM were quantitated either at the beginning of the study (baseline sample), before transfusion, or before surgery and either at 1-, 2-, 4-, 6-, and 8-week intervals after transfusion, after surgery, or after the baseline sample was obtained. RESULTS: IgM levels and the absolute number of B cells that coexpressed CD5 rose to twice pretransfusion levels in six of eight transfused sickle cell anemia patients and in four of five transfused orthopedic surgery patients. No comparable increases in CD5 B cells were noted in untransfused controls. Preexisting rheumatoid factor and antinuclear antibody levels increased in four of five transfused orthopedic surgery patients. One sickle cell anemia patient developed anti-Fya despite receiving Fya-negative blood. Increasing titers of anti-Fya paralleled the increases in IgM and CD5 B cells after transfusion. One patient who developed a positive direct antiglobulin test after transfusion had large increases in serum anticardiolipin IgM. Anticardiolipin IgM was subsequently eluted from direct antiglobulin test-positive red cells obtained after transfusion. Antibodies with anti-Fya-like activity and anticardiolipin IgM were produced in vitro by CD5 B cells and not by conventional CD5-negative B cells. CONCLUSION: An association was found between transfusion-induced increases in CD5 B cells and increased autoantibody production. These data may have implications for immunologic intervention to prevent the induction of red cell antibodies and other changes in the immune system caused by exposure to foreign antigens via blood transfusion.  相似文献   
94.
95.
We describe the case of a 68-year-old woman who presented with an acute onset spontaneous vaginal vault rupture and intestinal prolapse through the vagina. Results of a literature survey are presented and the causes of vaginal vault rupture are discussed.  相似文献   
96.
This randomized double-blind placebo-controlled study was initiated to analyze the behavior of epididymis, processus vaginalis and testicular descent in cryptorchid boys treated with a low dose (20 g) of a luteinizing hormone-releasing hormone analogue (Buserelin), administered daily, as a nasal spray, for a short period (28 days). Fifty-nine true cryptorchid boys were randomly assigned to 3 groups: buserelin, treatment [22], surgical treatment [18] or placebo control group [19]. The 3 groups of patients were similar before treatment in regard to testicular position, chronological and bone age, height and weight, luteinizing hormone, follicle-stimulating hormone, testosterone, penile size and the volume of the contralateral descended testis. None of the patients had retractile testes. Buserelin significantly induced testicular descent compared to the boys treated with a placebo (P<0.01). A normal epididymis was found more often in boys with successful descent (P<0.003). A closed processus vaginalis was also more frequently observed in the group treated with buserelin than in surgically treated one (P<0.05). In conclusion, buserelin was capable of inducing testicular descent besides provoking further development of the epididymis and closing the processus vaginalis.  相似文献   
97.
98.
As new and more effective treatments for Alzheimer's disease (AD) emerge, the development of efficient screening strategies in educationally and racially diverse primary care settings has increased in importance. A set of candidate screening tests and an independent diagnostic assessment were administered to a sample of 318 patients treated at a geriatric primary care center. Fifty-six subjects met criteria for dementia. Exploratory analysis led to the development of three two-stage screening strategies that differed in the composition of the first stage or Rapid Dementia Screen, which is applied to all patients over the age of 65. The second stage, applied to those patients who screen positively for dementia, is accomplished with the Free and Cued Selective Reminding Test to detect memory impairment. Using clinical diagnosis as a gold standard, the strategies had high sensitivity and specificity for identifying dementia and performed better for identifying AD than non-AD dementias. Sensitivity and specificity did not differ by race or education. The strategies provide an efficient approach to screening for early dementia.  相似文献   
99.
In a study of endogenous nitric oxide production in growth-retarded, very preterm newborns (<32 wk GA), urinary NOx/creatinine ratio and plasma guanosine 3',5'-cyclic monophosphate levels were determined during the early neonatal period. Newborns were divided into three groups: appropriate-for-gestational-age (AGA, n = 19), moderately small-for-gestational-age (SGA, n = 13) and severely SGA (n = 6) infants. Severely SGA infants showed significant higher values of nitric oxide derivatives during the first 24 h of life compared with the other groups. CONCLUSION: An increased NO production is found in SGA infants during the first 24 h after birth. This may reflect an increased intrauterine nitric oxide production in the feto-placental circulation found in cases with intrauterine growth retardation,  相似文献   
100.
颈内动脉注射血小板激活因子(PAF),再给伊文思蓝,可见脑实质染色程度加深,而颈内动脉只注射伊文思蓝,脑实质未见染色。而我们合成的新药SZ-1可剂量依赖性地抑制PAF诱导的脑实质伊文思蓝染色程度的加深。在体外培养的脑微血管平滑肌细胞上,PAF能显著刺激~(14)-花生四烯酸的释放,而SZ-1能剂量依赖性地抑制这种释放,提示PAF在脑内产生的损害除与其他因素相关外,还与其刺激花生四烯酸释放有密切关系,SZ-1对PAF引起的脑部损害有保护作用。  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