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   914篇
  免费   53篇
  国内免费   9篇
耳鼻咽喉   5篇
儿科学   22篇
妇产科学   27篇
基础医学   148篇
口腔科学   26篇
临床医学   67篇
内科学   243篇
皮肤病学   45篇
神经病学   80篇
特种医学   2篇
外科学   45篇
综合类   11篇
预防医学   121篇
眼科学   2篇
药学   66篇
中国医学   3篇
肿瘤学   63篇
  2024年   2篇
  2023年   13篇
  2022年   32篇
  2021年   40篇
  2020年   32篇
  2019年   44篇
  2018年   48篇
  2017年   30篇
  2016年   34篇
  2015年   41篇
  2014年   54篇
  2013年   63篇
  2012年   87篇
  2011年   87篇
  2010年   35篇
  2009年   35篇
  2008年   62篇
  2007年   51篇
  2006年   53篇
  2005年   38篇
  2004年   30篇
  2003年   23篇
  2002年   21篇
  2001年   3篇
  1998年   3篇
  1997年   3篇
  1996年   1篇
  1994年   1篇
  1992年   1篇
  1991年   1篇
  1987年   2篇
  1984年   1篇
  1980年   2篇
  1979年   1篇
  1977年   1篇
  1976年   1篇
排序方式: 共有976条查询结果,搜索用时 15 毫秒
71.
DNA vaccination using a plasmid encoding the rotavirus inner capsid VP6 has been explored in the mouse model of rotavirus infection. BALB/c mice were immunized with a VP6 DNA vaccine by the intramuscular, nasal and oral routes. VP6 DNA vaccination by the nasal and oral routes induced the production of anti-VP6 IgA antibodies by intestinal lymphoid cells. Intramuscular DNA injection stimulated the production of serum anti-VP6 IgG but not serum anti-VP6 IgA antibodies. Protection against shedding of rotaviruses in stools after oral challenge with the murine EDIM rotavirus strain was investigated in the immunized mice. A significant reduction in the level of rotavirus antigen shedding was demonstrated in those mice immunized at mucosal surfaces, both orally and nasally, with the VP6 DNA vaccine. Intramuscular DNA immunization, which elicited serum anti-VP6 IgG responses but not virus-specific intestinal IgA antibodies, did not provide significant protection against rotavirus challenge.  相似文献   
72.
Archer AM  Rico-Hesse R 《Virology》2002,304(2):274-281
The rodent-borne Arenaviruses are divided into two major antigenic groups: the Old World and New World complexes. Of the 15 known New World arenaviruses, four (Junin, Machupo, Sabia, and Guanarito) have been associated with hemorrhagic fever in humans. It has been difficult to assess the pathogenic or epidemic potential of the remaining viruses and the threat of emerging disease. We obtained full-length small (S) segment sequence data, encoding the nucleoprotein (NP) and glycoprotein precursor (GPC), from all American arenaviruses to predict their evolutionary and functional relationships. Phylogenetic analysis of NP or GPC amino acid sequences from all New World arenaviruses revealed three lineages and that Tamiami and Whitewater Arroyo viruses were probably derived from a single recombinant progenitor. The results imply that arenaviruses have been evolving independently for a very long time, leading to very diverse groupings that do not correlate with geography, rodent host, or human epidemic potential.  相似文献   
73.
Our aim was to estimate the prevalence of mutations in the BRCA1 and BRCA2 genes among unselected incident cases of breast cancer in young women. We identified 158 incident breast cancer cases diagnosed before age 46 years in predefined geographic areas in Girona and Tarragona, Spain, during 1995-1997. Of these, 136 (86%) provided information on family history of cancer and were screened for BRCA1 and BRCA2 mutations. Nine of the 136 (6.6%) were found to carry BRCA deleterious mutations (MUT) (1 BRCA1 and 8 BRCA2), and 20 were detected with rare BRCA variants of unknown significance (UV). Both MUT and US BRCA alterations were more frequent in younger patients: 7 (11.6%) MUT and 12 (19.3%) UV carriers were found in the group of 62 patients younger than 40 years, whereas 2 (2.7%) MUT and 9 (12%) US carriers were identified in the group of 74 patients aged 40-45. Family history of breast and ovarian cancers suggestive of hereditary condition (at least 2 first- or second-degree relatives affected with breast cancer or at least 1 relative affected with ovarian cancer or early-onset breast cancer) was absent for 5 of 9 MUT carriers. This suggests that BRCA screening policies based on family history of cancer would miss a considerable proportion of BRCA mutations. Mutations in the BRCA1 and BRCA2 genes explain at least 10% of breast cancer cases diagnosed before age 40 years. The contribution of these genes to early-onset breast cancer is likely to be even higher given that certain UV cases might be disease-associated.  相似文献   
74.
The use of alternative medicine products has increased tremendously in recent decades and it is estimated that approximately 80% of patients globally depend on them for some part of their primary health care. Propolis is a beekeeping product widely used in alternative medicine. It is a natural resinous product that bees collect from various plants and mix with beeswax and salivary enzymes and comprises a complex mixture of compounds. Various biomedical properties of propolis have been studied and reported in infectious and non-infectious diseases. However, the pharmacological activity and chemical composition of propolis is highly variable depending on its geographical origin, so it is important to describe and study the biomedical properties of propolis from different geographic regions. A number of chronic diseases, such as diabetes, obesity, and cancer, are the leading causes of global mortality, generating significant economic losses in many countries. In this review, we focus on compiling relevant information about propolis research related to diabetes, obesity, and cancer. The study of propolis could generate both new and accessible alternatives for the treatment of various diseases and will help to effectively evaluate the safety of its use.  相似文献   
75.
76.
77.
Inflammation - The pathogenesis of atopic dermatitis (AD) and psoriasis (Ps) overlaps, particularly the activation of the immune response and tissue damage. Here, we evaluated galectin (Gal)-1 and...  相似文献   
78.
Objective: Whole body vibration (WBV) is increasingly being used to improve balance and motor function and reduce the secondary complications associated with cerebral palsy (CP). The purpose of this study was to systematically appraise published research regarding the effects of static and/or dynamic exercise performed on a vibrating platform on gait, strength, spasticity and bone mineral density (BMD) within this population. Methods: Systematic searches of six electronic databases identified five studies that met our inclusion criteria (2 at Level II and 3 at Level III-2). Studies were analysed to determine: (a) participant characteristics; (b) optimal exercise and WBV treatment protocol; (c) effect on gait, strength, spasticity and BMD; and (d) the outcome measures used to evaluate effect. As data was not homogenous a meta-analysis was not possible. Results: Several design limitations were identified and intervention protocols are poorly described. The effects on strength, gait, spasticity and BMD in persons with CP remain inconclusive with weak evidence that WBV may improve selected muscle strength and gait parameters and that prolonged exposure may improve BMD; there is currently no evidence that WBV can reduce spasticity. Conclusions: The evidence for exercise performed on a vibrating platform on mobility, strength, spasticity and BMD in CP remains scant and further larger scale investigations with controlled parameters to better understand the effects of WBV exercises in this population is recommended.  相似文献   
79.
Introduction: Assessing dangerousness to gauge the likelihood of future violent behaviour has become an integral part of clinical mental health practice in forensic and non-forensic psychiatric settings, one of the most effective instruments for this being the Historical, Clinical and Risk Management-20 (HCR-20). Objective: To examine the HCR-20 factor structure in Mexican psychiatric inpatients and to obtain its predictive validity and reliability for use in this population. Method: In total, 225 patients diagnosed with psychotic, affective or personality disorders were included. The HCR-20 was applied at hospital admission and violent behaviours were assessed during psychiatric hospitalization using the Overt Aggression Scale (OAS). Construct validity, predictive validity and internal consistency were determined. Results: Violent behaviour remains more severe in patients classified in the high-risk group during hospitalization. Fifteen items displayed adequate communalities in the original designated domains of the HCR-20 and internal consistency of the instruments was high. Conclusion: The HCR-20 is a suitable instrument for predicting violence risk in Mexican psychiatric inpatients.  相似文献   
80.
AIM: To evaluate the Z-line visualization by the PillCam™ SB2 using three different ingestion protocols.METHODS: Ninety consecutive patients undergoing small bowel capsule endoscopy (SBCE) between January and May 2008 were included in the study. They swallowed the capsule in the standing (Group A = 30), supine (Group B = 30) and right supine positions (Group C = 30). Baseline patient characteristics, difficulties in capsule ingestion, esophageal transit times (ETT) and Z-line visualization were noted.RESULTS: No significant differences were found between the groups with regard to baseline patient characteristics, ingestion difficulties and complete SB examinations (P > 0.05). At least 1 frame of the Z-line was detected in 15.8%, 46.7% and 90% of patients in groups A, B and C, respectively (P < 0.001). The average number of Z-line images was 0.21 ± 0.53, 3.23 ± 6.59 and 5.53 ± 7.55 and the mean % of the Z-line detected was 71.3, 25.1 and 8.3, in groups A, B and C, respectively (both P < 0.001). ETT times were longer in the supine group followed by the right supine and the standing groups (median of 237 s vs 64 s and 39 s, respectively; P < 0.001).CONCLUSION: Z-line visualization in patients undergoing SBCE can be accurately achieved in most cases when the capsule is swallowed in the right supine position.  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