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   116876篇
  免费   7251篇
  国内免费   873篇
耳鼻咽喉   1230篇
儿科学   3469篇
妇产科学   2961篇
基础医学   15911篇
口腔科学   2790篇
临床医学   9365篇
内科学   25573篇
皮肤病学   2420篇
神经病学   10784篇
特种医学   4368篇
外国民族医学   26篇
外科学   15736篇
综合类   1855篇
一般理论   58篇
预防医学   7651篇
眼科学   1979篇
药学   9236篇
  8篇
中国医学   658篇
肿瘤学   8922篇
  2023年   563篇
  2022年   1308篇
  2021年   2368篇
  2020年   1549篇
  2019年   2089篇
  2018年   2641篇
  2017年   1928篇
  2016年   2125篇
  2015年   2464篇
  2014年   3250篇
  2013年   4640篇
  2012年   6279篇
  2011年   6542篇
  2010年   4116篇
  2009年   3627篇
  2008年   5670篇
  2007年   5923篇
  2006年   5621篇
  2005年   5274篇
  2004年   5474篇
  2003年   5317篇
  2002年   5308篇
  2001年   4240篇
  2000年   4125篇
  1999年   3408篇
  1998年   1389篇
  1997年   1094篇
  1996年   1014篇
  1995年   976篇
  1994年   815篇
  1993年   805篇
  1992年   2052篇
  1991年   2002篇
  1990年   1731篇
  1989年   1689篇
  1988年   1530篇
  1987年   1350篇
  1986年   1354篇
  1985年   1185篇
  1984年   888篇
  1983年   782篇
  1982年   513篇
  1981年   450篇
  1979年   632篇
  1978年   453篇
  1975年   474篇
  1974年   534篇
  1973年   501篇
  1972年   452篇
  1971年   425篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
The need to understand how an intervention is received by the beneficiary community is well recognised and particularly neglected in the micro–health insurance (MHI) domain. This study explored the views and reactions of the beneficiary community of the redesigned Community Health Fund (CHF) implemented in the Dodoma region of Tanzania. We collected data from focus group discussions with 24 groups of villagers (CHF members and nonmembers) and in‐depth interviews with 12 key informants (enrolment officers and health care workers). The transcribed material was analysed thematically. We found that participants highly appreciate the scheme, but to be resolved are the challenges posed by the implementation strategies adopted. The responses of the community were nested within a complex pathway relating to their interaction with the implementation strategies and their ongoing reflections regarding the benefits of the scheme. Community reactions ranged from accepting to rejecting the scheme, demanding the right to receive benefit packages once enrolled, and dropping out of the scheme when it failed to meet their expectations. Reported drivers of the responses included intensity of CHF communication activities, management of enrolment procedures, delivery of benefit packages, critical features of the scheme, and contextual factors (health system and socio‐political context). This study highlights that scheme design and implementation strategies that address people's needs, voices, and values can improve uptake of MHI interventions. The study adds to the knowledge base on implementing MHI initiatives and could promote interests in assessing the response to interventions within the MHI domain and beyond.  相似文献   
22.
The list of motives by Kanin (1994) is the most cited list of motives to file a false allegation of rape. Kanin posited that complainants file a false allegation out of revenge, to produce an alibi or to get sympathy. A new list of motives is proposed in which gain is the predominant factor. In the proposed list, complainants file a false allegation out of material gain, emotional gain, or a disturbed mental state. The list can be subdivided into eight different categories: material gain, alibi, revenge, sympathy, attention, a disturbed mental state, relabeling, or regret. To test the validity of the list, a sample of 57 proven false allegations were studied at and provided by the National Unit of the Dutch National Police (NU). The complete files were studied to ensure correct classification by the NU and to identify the motives of the complainants. The results support the overall validity of the list. Complainants were primarily motivated by emotional gain. Most false allegations were used to cover up other behavior such as adultery or skipping school. Some complainants, however, reported more than one motive. A large proportion, 20% of complainants, said that they did not know why they filed a false allegation. The results confirm the complexity of motivations for filing false allegations and the difficulties associated with archival studies. In conclusion, the list of Kanin is, based on the current results, valid but insufficient to explain all the different motives of complainants to file a false allegation.  相似文献   
23.
24.
Introduction: A seasonal affective disorder (SAD) is a subtype of unipolar and bipolar major depressive disorders. It is characterized by its annual recurrence of depressive episodes at a particular season, mostly seen in winter and is responsible for 10–20% of the prevalence of major depressive disorders. Some pathophysiological hypotheses, such as the phase delay and the monoamine depletion hypotheses, have been postulated but the exact cause has not been fully unraveled yet. Studies on treatment for SAD in the last decade are lacking. To tackle this chronic disease, attention needs to be drawn to the gaps in this research field.

Areas covered: In this systematic review, the authors give a broad overview of the pharmacological therapy available for SAD. Also, nutritional substances fitting well with the postulated hypotheses are reviewed for the treatment and prevention of SAD. There is a specific focus on the quality of the currently performed studies.

Expert opinion: Light therapy and fluoxetine are the only proven and effective acute treatment options for SAD, while bupropion is the only registered drug for prevention of SAD. This area of research is in dire need of valid large-scale and sufficiently reproducible randomized control trials.  相似文献   

25.
Myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction. Most patients have pathogenic autoantibodies against the acetylcholine receptor (AChR). In the last years a novel subpopulation of MG patients has been described that harbors antibodies against low-density lipoprotein receptor-related protein 4 (Lrp4), another postsynaptic neuromuscular antigen. In early-onset AChR MG (EOMG), the thymus plays an important role in immunopathogenesis, and early thymectomy is beneficial. It is still unknown if the thymus plays any role in Lrp4-MG. In this pilot study, we compared thymus samples from four patients with Lrp4-MG (one pre-treated with immunosuppressive drugs), four non-MG controls and five EOMG patients (not pretreated with immunosuppressive drugs). Immunohistochemistry of the Lrp4-MG thymi revealed normal architecture, with normal numbers and distribution of B-cells, lymphoid follicles and Hassall's corpuscles. Primary CD23+ lymphoid follicles were similarly infrequent in Lrp4-MG and control thymic sections. In none of the control or Lrp4-MG thymi did we find secondary follicles with CD10+ germinal centers. These were evident in 2 of the 5 EOMG thymi, where primary lymphoid follicles were also more frequent on average, thus showing considerable heterogeneity between patients. Even if characteristic pathological thymic changes were not observed in the Lrp4 subgroup, we cannot exclude a role for the thymus in Lrp4-MG pathogenesis, since one Lrp4-MG patient went into clinical remission after thymectomy alone (at one year follow-up) and one more improved after thymectomy in combination with immunosuppressive therapy.  相似文献   
26.
Clinical and Experimental Medicine - Vasculopathy is a crucial feature of systemic sclerosis (SSc), and Raynaud’s phenomenon (RP) and digital ulcers (DU) have a deep impact on the quality of...  相似文献   
27.
28.
Interferon-γ inducible protein 10 (IP-10), is a potent chemoattractant that promotes migration of monocytes and activated T-cells to inflammation foci. IP-10 is elevated in serum of patients with chronic hepatitis C virus (HCV) and tuberculosis (TB) infections, although it remains to be determined the contribution of IP-10 in restricting Mycobacterium tuberculosis (Mtb) replication. Here, we investigated the impact of IP-10 on mycobacteria replication using the ex vivo model of human whole-blood (WB) assay. In particular, we compared the levels of IP-10 upon infection with different Mtb clinical strains and species of non-tuberculous mycobacteria (NTM) and evaluated how IP-10 may contain bacterial replication. Interestingly, we observed that the inhibition of the host enzyme dipeptidyl peptidase IV (DPP-IV), which inactivates IP-10 through cleavage of two amino acids at the chemokine N-terminus, restricted mycobacterial persistence in WB, supporting the critical role of full length IP-10 in mediating an anti-Mtb response. Addition of recombinant IP-10 expressed in eukaryotic cells enhanced the anti-mycobacterial activity in WB, although no differences were observed when IP-10 containing different proportions of cleaved and non-cleaved forms of the chemokine were added. Moreover, recombinant IP-10 did not exert a direct anti-mycobacterial effect. Our results underscore the clinical relevance of IP-10 in mycobacteria pathogenesis and support the potential outcomes that may derive by targeting the IP-10/CXCR3 pathway as host directed therapies for the treatment of Mtb or NTM infections.  相似文献   
29.
30.
Intraductal carcinoma of the prostate (IDC-P) most often appears associated with high-grade invasive prostate carcinoma (PCa), where it is believed to represent retrograde spread. However, IDC-P rarely occurs as an isolated finding at radical prostatectomy or with concurrent low-grade (Grade Group 1) invasive carcinoma. We hypothesized that isolated IDC-P (iIDC-P) in these unusual cases may represent a distinct in situ lesion and molecularly profiled 15 cases. iIDC-P was characterized by copy number alteration (CNA) profiling and targeted next generation sequencing in cases with sufficient tissue (n = 7). Immunohistochemistry for PTEN and ERG was performed on the total cohort (n = 15), where areas of iIDC-P and associated invasive disease were evaluated separately (n = 9). By copy number profiling, iIDC-P alterations were similar to those previously described in high-grade invasive PCa (PTEN, RB1, and CHD1 loss; MYC gain). However, in four cases, targeted sequencing revealed a striking number of activating oncogenic driver mutations in MAPK and PI3K pathway genes, which are extraordinarily rare in conventional PCa. In addition, pathogenic mutations in DNA repair genes were found in two cases of iIDC-P (BRCA2, CHEK2, CDK12) and other known PCa-associated mutations (FOXA1, SPOP) in two cases. Overall, ERG was expressed in 7% (1/15) of the iIDC-P lesions and PTEN was lost in 53% (8/15). Discordance for ERG or PTEN status between IDC-P and the low-grade PCa was observed in five of nine cases, with intact PTEN in the invasive tumor and PTEN loss in IDC-P in four. Despite a CNA profile similar to conventional PCa, iIDC-P is enriched with potentially targetable oncogenic driver mutations in MAPK/PI3K genes. Based on PTEN and ERG status, iIDC-P is not likely a precursor to the associated low-grade invasive PCa, but represents a molecularly unique in situ tumor of unclear clinical significance. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.  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