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   1001篇
  免费   86篇
  国内免费   6篇
耳鼻咽喉   13篇
儿科学   59篇
妇产科学   50篇
基础医学   195篇
口腔科学   22篇
临床医学   96篇
内科学   179篇
皮肤病学   12篇
神经病学   125篇
特种医学   8篇
外科学   53篇
综合类   10篇
一般理论   1篇
预防医学   123篇
眼科学   28篇
药学   56篇
肿瘤学   63篇
  2024年   5篇
  2023年   10篇
  2022年   21篇
  2021年   33篇
  2020年   31篇
  2019年   31篇
  2018年   31篇
  2017年   30篇
  2016年   32篇
  2015年   25篇
  2014年   53篇
  2013年   54篇
  2012年   73篇
  2011年   85篇
  2010年   49篇
  2009年   50篇
  2008年   69篇
  2007年   55篇
  2006年   61篇
  2005年   57篇
  2004年   63篇
  2003年   51篇
  2002年   37篇
  2001年   6篇
  2000年   9篇
  1999年   10篇
  1998年   9篇
  1997年   5篇
  1996年   5篇
  1995年   4篇
  1994年   3篇
  1993年   5篇
  1992年   4篇
  1991年   5篇
  1990年   1篇
  1989年   5篇
  1987年   3篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1983年   2篇
  1980年   3篇
  1979年   3篇
  1977年   1篇
  1976年   1篇
排序方式: 共有1093条查询结果,搜索用时 15 毫秒
81.
Ossifying fibromas are uncommon benign tumors of the craniofacial skeleton thought to originate from the periodontal ligament. Most are small and incidentally diagnosed with routine dental radiographs. With larger lesions, patients may complain of an abnormal bite or an enlarging mass. This tumor involves slow-evolving growth with deforming swelling generally arising in the mandible, with possible early tooth displacement. From the radiological perspective, more than 50% of the lesions exhibit an expansion of the jaws and 53% shows well-defined unilocular radiolucencies and 40% are mixed radiolucent-radiopaque lesions. The lesions exceptionally can be radiopaque. Ossifying fibroma presents several variant histopathological subtypes. The overlapping clinical and histopathological features of these subtypes have led to diagnostic dilemma and confusion. Complete excision of this tumor has become a necessity since it is notorious for recurrence. We present here two cases of ossifying fibroma of the jaws along with insight into the literature review.  相似文献   
82.
To identify therapeutic opportunities for oncolytic viral therapy, we conducted genome-wide RNAi screens to search for host factors that modulate rhabdoviral oncolysis. Our screens uncovered the endoplasmic reticulum (ER) stress response pathways as important modulators of rhabdovirus-mediated cytotoxicity. Further investigation revealed an unconventional mechanism whereby ER stress response inhibition preconditioned cancer cells, which sensitized them to caspase-2-dependent apoptosis induced by a subsequent rhabdovirus infection. Importantly, this mechanism was tumor cell specific, selectively increasing potency of the oncolytic virus by up to 10,000-fold. In?vivo studies using a small molecule inhibitor of IRE1α showed dramatically improved oncolytic efficacy in resistant tumor models. Our study demonstrates proof of concept for using functional genomics to improve biotherapeutic agents for cancer.  相似文献   
83.
84.
Community- and individual-level data were collected from interviews with 1,294 boys and girls, 13 to 19 years old, in three impoverished urban communities of Beirut. Univariate analyses of variables provide quantitative indicators of adolescents' lives and communities. Researchers including the authors, interested in using these indicators to plan for community interventions with youth in the Palestinian refugee camp, discuss the pertinent results with youth from the camp in six focus groups. The authors find that many indicators misrepresent the situation of youth in the camp. For example, adolescents may have underreported cigarette and argileh (water pipe) smoking (8.3% and 22.4%, respectively) because of the lack of social desirability of these behaviors; other questions may have been misunderstood, such as perceived health and health compared to others. Also, important issues for them such as drug abuse, violence, and school problems were not asked. Implications for intervention research are discussed.  相似文献   
85.
Fever, genes, and epilepsy   总被引:16,自引:0,他引:16  
About 13% of patients with epilepsy have a history of febrile seizures (FS). Studies of familial forms suggest a genetic component to the epidemiological link. Indeed, in certain monogenic forms of FS, for which several loci have been reported, some patients develop epilepsy with a higher risk than in the general population. Patients with generalised epilepsy with febrile seizures plus (GEFS+) can have typical and isolated FS, FS lasting more beyond age 6 years, and subsequent afebrile (typically generalised) seizures. Mutations associated with GEFS+ were identified in genes for subunits of the voltage-gated sodium channel and the gamma2 subunit of the ligand-gated GABAA receptor. Screening for these genes in patients with severe myoclonic epilepsy in infancy showed de novo mutations of the alpha1 subunit of the voltage-gated sodium channel. Antecedent FS are commonly observed in temporal-lobe epilepsy (TLE). In sporadic mesial TLE-characterised by the sequence of complex FS in childhood, hippocampal sclerosis, and refractory temporal-lobe seizures-association studies suggested the role of several susceptibility genes. Work on some large pedigrees also suggests that FS and temporal-lobe seizures may have a common genetic basis, whether hippocampus sclerosis is present or not. The molecular defects identified in the genetic associations of FS and epileptic seizures are very attractive models to aid our understanding of epileptogenesis and susceptibility to seizure-provoking factors, especially fever.  相似文献   
86.
BACKGROUND: A number of publications focusing on health care workers (HCWs) during a severe acute respiratory syndrome (SARS) outbreak have suggested that HCWs experienced psychological distress, particularly increased levels of posttraumatic stress symptomatology (PTSS). Factors contributing to increased distress in HCWs working in high-risk areas treating patients with SARS have not been fully elucidated. The goal of this study was to quantify the psychological effects of working in a high-risk unit during the SARS outbreak. METHODS: HCWs in a Toronto hospital who worked in high-risk areas completed a questionnaire regarding their attitude toward the SARS crisis along with the Impact of Event Scale-Revised, which screens for PTSS. The comparison group consisted of clinical units that had no contact with patients infected with SARS. RESULTS: Factors that were identified to cause distress in the 248 respondent HCWs were the following: (a) perception of risk to themselves, (b) impact of the SARS crisis on their work life, (c) depressive affect, and (d) working in a high-risk unit. In addition, HCWs who cared for only one SARS patient in comparison to those caring for multiple SARS patients experienced more PTSS. CONCLUSIONS: As expected, HCWs who were working in high-risk units experienced greater distress. Contrary to expectations, HCWs who experienced greater contact with SARS patients while working in the high-risk units were less distressed. This suggests that HCW experience in treating patients infected with SARS may be a mediating factor that could be amenable to intervention in future outbreaks.  相似文献   
87.
88.
Live, cold-adapted, temperature-sensitive (ca/ts) Russian influenza A vaccines are prepared in eggs by a 6:2 gene reassortment of the ca/ts donor strain A/Leningrad/134/17/57 (H2N2) (Len/17) with a current wild-type (wt) influenza A strain contributing hemagglutinin (HA) and neuraminidase (NA) genes. However, egg-derived reassortant vaccines are potentially more problematic to manufacture in large quantities than vaccines from cell-based procedures. To compare egg- and cell culture-derived reassortant vaccines, we prepared in Madin Darby canine kidney (MDCK) cells two cloned, ca/ts reassortants (25M/1, 39E/2) derived from Len/17 and a wt reference strain A/New Caledonia/20/99 (H1N1) (NC/wt). Both 25M/1 and 39E/2 reassortants preserved the ca/ts phenotype and mutations described for internal genes of the A/Len/17 parent. When compared to a commercial, egg-derived ca/ts Russian A/17/NC/99/145 (H1N1) New Caledonia vaccine (NC/145), the MDCK-derived reassortant 39E/2 vaccine conferred similar levels of protection in ferrets challenged i.n. with 7 x 10(10) pfu of NC/wt. In a dose-ranging study, the protective vaccine dose for 50% of ferrets (PD50) was less than 1.2 x 10(4) pfu for the 25M/1 vaccine derived by recombination and amplification in MDCK cells. Clonal isolates of ca/ts influenza A/New Caledonia/20/99 (H1N1) obtained by recombination and amplification entirely in MDCK cells can be highly protective i.n. vaccines.  相似文献   
89.
90.
Post‐transplantation cyclophosphamide (PTCy) is an effective strategy to prevent graft‐versus‐host disease (GVHD) after haploidentical haematopoietic cell transplantation (HCT). We determined the efficacy of PTCy‐based GVHD prophylaxis in human leucocyte antigen (HLA)‐mismatched unrelated donor (MMUD) HCT. We analysed 113 adult patients with high‐risk haematological malignancies who underwent one‐antigen MMUD transplantation between 2009 and 2013. Of these, 41 patients received PTCy, tacrolimus and mycophenolate mofetil (MMF) for GVHD prophylaxis; 72 patients received conventional prophylaxis with anti‐thymocyte globulin, tacrolimus and methotrexate. Graft source was primarily bone marrow (83% PTCy vs. 63% conventional group). Incidence of grade II–IV (37% vs. 36%, P = 0·8) and grade III–IV (17% vs. 12%, P = 0·5) acute GVHD was similar at day 100. However, the incidence of grade II‐IV acute GVHD by day 30 was significantly lower in the PTCy group (0% vs. 15%, P = 0·01). Median time to neutrophil (18 days vs. 12 days, P < 0·001) and platelet (25·5 days vs. 18 days, P = 0·05) engraftment was prolonged in PTCy group. Rates of graft failure, chronic GVHD, 2‐year non‐relapse mortality, relapse, progression‐free survival or overall survival were similar. Our results demonstrate that PTCy, tacrolimus and MMF for GVHD prophylaxis is safe and produced similar results as conventional prophylaxis in patients with one antigen HLA‐MMUD HCT.  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