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   1593789篇
  免费   133615篇
  国内免费   2576篇
耳鼻咽喉   21651篇
儿科学   52858篇
妇产科学   46233篇
基础医学   226241篇
口腔科学   47222篇
临床医学   140220篇
内科学   312882篇
皮肤病学   34075篇
神经病学   129449篇
特种医学   64719篇
外国民族医学   474篇
外科学   243852篇
综合类   39680篇
现状与发展   3篇
一般理论   545篇
预防医学   122131篇
眼科学   36499篇
药学   121277篇
  2篇
中国医学   2887篇
肿瘤学   87080篇
  2018年   14836篇
  2016年   12974篇
  2015年   15097篇
  2014年   20732篇
  2013年   31447篇
  2012年   42709篇
  2011年   44894篇
  2010年   26427篇
  2009年   25381篇
  2008年   43131篇
  2007年   45387篇
  2006年   46212篇
  2005年   44831篇
  2004年   44249篇
  2003年   42197篇
  2002年   41338篇
  2001年   75711篇
  2000年   78281篇
  1999年   66092篇
  1998年   16747篇
  1997年   15362篇
  1996年   15298篇
  1995年   15972篇
  1994年   15017篇
  1993年   14174篇
  1992年   55445篇
  1991年   53817篇
  1990年   52602篇
  1989年   50876篇
  1988年   47267篇
  1987年   46600篇
  1986年   44313篇
  1985年   42889篇
  1984年   32024篇
  1983年   27553篇
  1982年   16102篇
  1981年   14383篇
  1980年   13507篇
  1979年   30435篇
  1978年   21034篇
  1977年   17706篇
  1976年   16658篇
  1975年   17529篇
  1974年   21466篇
  1973年   20655篇
  1972年   18855篇
  1971年   17763篇
  1970年   16280篇
  1969年   15274篇
  1968年   13954篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.

Objective

To investigate the efficacy and safety of an influenza vaccination in patients with myasthenia gravis with acetylcholine receptor antibodies (AChR MG).

Methods

An influenza vaccination or placebo was administered to 47 AChR MG patients. Before and 4?weeks after administration blood samples and clinical outcome scores were obtained. Antibodies to the vaccine strains A/California/7/2009 (H1N1)pdm09, A/Hong Kong/4801/14 (H3N2) and B/Brisbane/060/08 were measured using the hemagglutination-inhibition (HI) assay and disease-specific AChR antibody titers were measured with a radio-immunoprecipitation assay. Forty-seven healthy controls (HC) were vaccinated with the same influenza vaccine to compare antibody titers.

Results

A post-vaccination, seroprotective titer (HI?≥?1:40) was achieved in 89.4% of MG patients vs. 93.6% in healthy controls for the H3N2 strain, 95.7% vs 97.9% for the H1N1 strain and 46.8 vs 51% for the B-strain. A seroprotective titer for all three strains of the seasonal influenza vaccine was reached in 40.4% (19/47) of the MG group and in 51% (24/47) of the HC group. Immunosuppressive medication did not significantly influence post geomean titers (GMT). The titers of disease-specific AChR antibodies were unchanged 4?weeks after vaccination. The clinical outcome scores showed no exacerbation of MG symptoms.

Conclusion

The antibody response to an influenza vaccination in patients with AChR MG was not different from that in healthy subjects, even in AChR MG patients using immunosuppressive medication. Influenza vaccination does not induce an immunological or clinical exacerbation of AChR MG.

Clinical trial registry

The influenza trial is listed on clinicaltrialsregister.eu under 2016-003138-26.  相似文献   
72.
73.
74.
MALT1 is a key mediator of NF-κB signaling and a main driver of B-cell lymphomas. Remarkably, MALT1 is expressed in the majority of pancreatic ductal adenocarcinomas (PDACs) as well, but absent from normal exocrine pancreatic tissue. Following, MALT1 shows off to be a specific target in cancer cells of PDAC without affecting regular pancreatic cells. Therefore, we studied the impact of pharmacological MALT1 inhibition in pancreatic cancer and showed promising effects on tumor progression. Mepazine (Mep), a phenothiazine derivative, is a known potent MALT1 inhibitor. Newly, we described that biperiden (Bip) is a potent MALT1 inhibitor with even less pharmacological side effects. Thus, Bip is a promising drug leading to reduced proliferation and increased apoptosis in PDAC cells in vitro and in vivo. By compromising MALT1 activity, nuclear translocation of c-Rel is prevented. c-Rel is critical for NF-κB-dependent inhibition of apoptosis. Hence, off-label use of Bip or Mep represents a promising new therapeutic approach to PDAC treatment. Regularly, the Anticholinergicum Bip is used to treat neurological side effects of Phenothiazines, like extrapyramidal symptoms.  相似文献   
75.
76.
Definitive radiotherapy is an effective single-modality in T1 glottic cancer. Hypofractionated schemes could offer excellent results in a shorter treatment period. We aimed to evaluate the clinical outcomes and toxicity comparing conventional vs. hypofractionated radiotherapy treatment in T1N0M0-glottic cancer. Between Jan-1st, 2005 and August-1st, 2017, in a prospective cohort study, with 10-year follow-up, 138 patients were treated with conventional schedule 2 Gy/day, total dose 70 Gy/7 weeks (N = 71) or hypofractionated schedule 2, 2–2, 25 Gy/day, total dose 63, 8–63 Gy/5, 5 weeks (N = 67). Endpoints were clinical-response rate, local relapse-free survival (LRFS), laryngectomy-free survival (LFS), toxicity rates, relapse-free survival (RFS), metastasis-free survival (MFS), second tumour-free survival (2TFS), and overall survival (OS). All patients showed a complete clinical response. No differences were found for LRFS (p = 0.869), LFS (p = 0.975), RFS (p = 0.767), MFS (p = 0.601), 2TFS (p = 0.293), or OS (p = 0.685). Acute toxicity for skin and mucosae was similar (p = 0.550 and p = 0.698). Acute laryngeal toxicity was higher in the hypofractionation group (p = 0.004), due to an increase in slight moderate grade. No differences in late laryngeal edema were found (p = 0.989). Radiotherapy offers high rate survival, local control, and larynx preservation after 5–10-year follow-up. A hypofractionation could be preferable, since it offers the same results as conventional with fewer treatment sessions.  相似文献   
77.

Purpose

Understanding the attitudes of physicians toward the use of pre-exposure prophylaxis (PrEP) for HIV prevention among youth is critical to improving access to PrEP. We examined PrEP-related attitudes among physicians who provide primary care to 13- to 21-year-old adolescents.

Methods

Individual, in-depth, semistructured interviews were conducted with 38 physicians from adolescent medicine, family practice, internal medicine/medicine-pediatrics, obstetrics/gynecology, and pediatrics who care for any adolescents younger than 18 years. Interviews assessed familiarity with PrEP, perceived benefits and barriers to providing PrEP to adolescents, facilitating factors for prescribing PrEP, and likelihood of recommending and prescribing PrEP to adolescents.

Results

Mean age was 44.6 years (standard deviation 10.9). Fourteen physicians (37%) reported being somewhat or very familiar with PrEP. Perceived benefits of prescribing PrEP included decreased acquisition/rates of HIV, improved provision of sexual health services, and improved patient awareness of HIV risk. Barriers to PrEP were reported at the patient (e.g., lack of acceptability to patients), provider (e.g., concerns about patient adherence, safety/side effects, parents as a barrier to PrEP use), and system (e.g., high cost) levels. Facilitating factors for prescribing PrEP included low cost/coverage by insurance, physician education about PrEP, patient educational materials, and clinical guidelines for PrEP use in youth. A higher proportion of physicians reported being highly or somewhat likely to recommend (N = 16, 42%) than prescribe PrEP (N = 13, 34%).

Conclusions

In this study of primary care physician attitudes toward PrEP prescribing for adolescents, physicians identified numerous barriers to providing PrEP. Addressing these barriers may increase adolescents' access to PrEP.  相似文献   
78.

Objectives

Anti–programmed cell death 1 (PD-1)/programmed death ligand 1 (PD-L1) immunotherapy has demonstrated success in the treatment of advanced NSCLC. Recently, PD-1/PD-L1 blockade also has demonstrated interesting results in small trials of neoadjuvant treatment in stage IB to IIIA NSCLC. In addition, several clinical trials using anti–PD-1/PD-L1 immunotherapy as an adjuvant or neoadjuvant treatment in patients with resectable stage NSCLC are ongoing. However, few analyses of anti–PD-1/PD-L1 immunotherapy–related biomarkers in early-stage squamous cell lung carcinoma (SqCLC) have been reported. In this study, we evaluated PD-L1 protein expression, tumor mutation burden, and expression of an immune gene signature in early-stage SqCLC, providing data for identifying the potential role for patients with anti–PD-1/PD-L1 treatment in early-stage SqCLC.

Methods

A total of 255 specimens from patients with early-stage SqCLC were identified within participating centers of the Strategic Partnering to Evaluate Cancer Signatures program. PD-L1 protein expression by immunohistochemistry was evaluated by using the Dako PD-L1 22C3 pharmDx kit on the Dako Link 48 auto-stainer (Dako, Carpinteria, CA). Tumor mutation burden (TMB) was calculated on the basis of data from targeted genome sequencing. The T-effector and interferon gamma (IFN-γ) gene signature was determined from Affymetrix gene chip data (Affymetrix, Santa Clara, CA) from frozen specimens.

Results

The prevalence of PD-L1 expression was 9.8% at a tumor proportion score cutoff of at least 50%. PD-L1 mRNA and programmed cell death 1 ligand 2 mRNA positively correlated with PD-L1 protein expression on tumor cells (TCs) and tumor-infiltrating immune cells. PD-L1 protein expression on tumor-infiltrating immune cells was correlated with the T-effector and IFN-γ gene signature (p < 0.001), but not with TMB. For TCs, all of these biomarkers were independent of each other and neither PD-L1 protein expression, TMB, or T-effector and IFN-γ gene signatures were independently prognostic for patient outcomes.

Conclusions

Evaluation of PD-L1 expression, TMB, and T-effector and IFN-γ gene signatures in the cohort with early-stage SqCLC found them to be independent of each other, and none was associated with overall survival. Our results also support the hypothesis that PD-L1 expression is regulated by an intrinsic mechanism on TCs and an adaptive mechanism on immune cells.  相似文献   
79.
Uptake of colorectal cancer screening remains suboptimal. Mailed fecal immunochemical testing (FIT) offers promise for increasing screening rates, but optimal strategies for implementation have not been well synthesized. In June 2019, the Centers for Disease Control and Prevention convened a meeting of subject matter experts and stakeholders to answer key questions regarding mailed FIT implementation in the United States. Points of agreement included: 1) primers, such as texts, telephone calls, and printed mailings before mailed FIT, appear to contribute to effectiveness; 2) invitation letters should be brief and easy to read, and the signatory should be tailored based on setting; 3) instructions for FIT completion should be simple and address challenges that may lead to failed laboratory processing, such as notation of collection date; 4) reminders delivered to initial noncompleters should be used to increase the FIT return rate; 5) data infrastructure should identify eligible patients and track each step in the outreach process, from primer delivery through abnormal FIT follow-up; 6) protocols and procedures such as navigation should be in place to promote colonoscopy after abnormal FIT; 7) a high-quality, 1-sample FIT should be used; 8) sustainability requires a program champion and organizational support for the work, including sufficient funding and external policies (such as quality reporting requirements) to drive commitment to program investment; and 9) the cost effectiveness of mailed FIT has been established. Participants concluded that mailed FIT is an effective and efficient strategy with great potential for increasing colorectal cancer screening in diverse health care settings if more widely implemented.  相似文献   
80.
Liu  R.  Zhou  J.  Xia  S.  Li  T. 《Clinical & translational oncology》2020,22(5):694-702
Clinical and Translational Oncology - The specific association between PTEN deletion or ERG rearrangement and the recurrence of prostate cancer (PC) treated with radical prostatectomy (RP) or...  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