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   784篇
  免费   73篇
  国内免费   8篇
耳鼻咽喉   9篇
儿科学   49篇
妇产科学   24篇
基础医学   112篇
口腔科学   31篇
临床医学   68篇
内科学   167篇
皮肤病学   20篇
神经病学   61篇
特种医学   93篇
外科学   82篇
综合类   19篇
预防医学   26篇
药学   39篇
肿瘤学   65篇
  2022年   12篇
  2021年   7篇
  2020年   5篇
  2019年   13篇
  2018年   10篇
  2017年   8篇
  2016年   15篇
  2015年   21篇
  2014年   31篇
  2013年   29篇
  2012年   33篇
  2011年   26篇
  2010年   52篇
  2009年   35篇
  2008年   33篇
  2007年   26篇
  2006年   26篇
  2005年   24篇
  2004年   21篇
  2003年   22篇
  2002年   13篇
  2001年   13篇
  2000年   16篇
  1999年   14篇
  1998年   30篇
  1997年   38篇
  1996年   38篇
  1995年   30篇
  1994年   19篇
  1993年   18篇
  1992年   7篇
  1991年   15篇
  1990年   12篇
  1989年   17篇
  1988年   22篇
  1987年   23篇
  1986年   11篇
  1985年   16篇
  1984年   8篇
  1983年   6篇
  1982年   7篇
  1981年   10篇
  1980年   5篇
  1978年   3篇
  1977年   5篇
  1976年   5篇
  1975年   2篇
  1974年   2篇
  1969年   2篇
  1968年   2篇
排序方式: 共有865条查询结果,搜索用时 0 毫秒
21.
Raltegravir (RAL) is the only licensed human immunodeficiency virus (HIV) integrase inhibitor. The factors associated with the virological response to RAL-containing regimens and the prevalence of integrase mutations associated with RAL failure deserve further investigation. From the Antiretroviral Resistance Cohort Analysis database, we selected triple-class-experienced subjects failing their current treatment with complete treatment history available. Selection criteria included HIV-RNA, CD4 count and HIV genotype within 3 months of RAL initiation. Factors associated with 24-week response were analysed; genotypic sensitivity scores (GSS) and weighted-GSS were evaluated. Virological response was achieved in 74.3% of 105 subjects. Mutations associated with RAL failure were detected in 12/24 subjects with an integrase genotype, with the prevalence of Q148H + G140S. Each extra unit of GSS (p 0.05, OR 2.62; 95% CI 1.00–6.87). was found to be a associated with response. Weighted-GSS had borderline statistical significance (p 0.063, OR 2.04; 95% CI 0.96–4.33) When stratifying for different cut-offs (< 1 as reference, 1–1.49, ≥ 1.5), a borderline significant increase in the probability of response appeared for GSS ≥ 1.5 (p 0.053, OR 4.00; 95% CI 0.98–16.25). GSS ≥ 1 showed the highest sensitivity, 82.6%. Receiver operating characteristic curves depicted the widest area under the curve (0.663, p 0.054) of GSS ≥ 1. Unresponsiveness to RAL-containing regimens among triple-class-experienced subjects was low. The activity of the background regimen was strongly associated with response. Although few integrase genotypes were available at failure, half of these were without integrase resistance mutations. The substantial rate of RAL failure in the absence of known RAL-resistance mutations may be associated with adherence issues and this issue warrants further analysis in longer observations.  相似文献   
22.
23.
The choice of an antiretroviral regimen can often impact on adherence, treatment satisfaction and therefore influence on clinical outcome. These concerns are particularly true in adolescents. In this setting, adherence is usually affected by multifactor events and biopsychosocial factors, which connect and changeover time. We evaluated the effect of a switch to a single-pill fixed-dose regimen on patient-reported outcomes, virologic and immunologic outcomes, and safety in a cohort of adolescents with perinatal HIV-1 infection. In addition, we evaluated the effect on low-level residual HIV-RNA. An open-label, non-randomised study was performed: 12 adolescents with a confirmed viremia <50 copies/mL treated with lamivudine or emtricitabine, tenofovir and efavirenz were switched to one-pill fixed-dose regimen of emtricitabine/tenofovir/efavirenz. At the end of follow-up, the new regimen was associated with improvements in treatment satisfaction, HIV-symptoms, whereas adherence remained high. No immunological or virological significative changes were observed. No side-effects were registered. Moreover, the low-level residual HIV-RNA was <3 copie/mL in all patients. One-pill fixed-dose regimen is an added value that favours adherence, reduces HIV-symptoms, improves patients' satisfaction and could better control of HIV-RNA in adolescents, too.  相似文献   
24.
Polycythemia associated with acromegaly is usually caused by the systemic manifestations of the disease, such as sleep-apnea or concomitant erythropoietin-secreting kidney tumors. The recognition of underlying pathologies requires a thorough diagnostic process. We report a unique case of acromegaly with polycythemia, not caused by commonly described manifestations of the disease, and receding with octreotide therapy. The medical history of 141 acromegalic patients followed by the Endocrinology Unit of the San Martino University Hospital in Genoa has been also reviewed, together with the literature evidence for similar cases. The diagnostic workflow and 2-years follow-up of a 43-years old acromegalic, polycythemic man with a history of past smoking, moderate hypertension, and mental retardation are described. The hematological parameters of our cohort was retrospectively compared with those of a healthy, age/gender-related control group as well. Therapy with octreotide LAR, 20?mg i.m. q28d was begun soon after diagnosis of acromegaly in the polycythemic patient. Haematocrit level, hormonal setting, as well as pituitary tumor size and visual perimetry during treatment were recorded. Octreotide LAR treatment normalized hormonal alterations, as well as hematological parameters. Polycythemia has not recurred after 2?years of therapy. The median hemoglobin and hematocrit levels of the retrospectively analyzed cohort of acromegalic were significantly lower than normal ranges of a healthy, age/sex- related control population. In conclusions, polycythemia can be a direct, albeit rare, secondary manifestation of acromegaly, that must be considered during the diagnostic work-up of acromegalic patients presenting with such disorder.  相似文献   
25.
26.
Stem cells have huge applications in the field of tissue engineering and regenerative medicine. Their use is currently not restricted to the life-threatening diseases but also extended to disorders involving the structural tissues, which may not jeopardize the patients’ life, but certainly influence their quality of life. In fact, a particularly popular line of research is represented by the regeneration of bone and cartilage tissues to treat various orthopaedic disorders. Most of these pioneering research lines that aim to create new treatments for diseases that currently have limited therapies are still in the bench of the researchers. However, in recent years, several clinical trials have been started with satisfactory and encouraging results. This article aims to review the concept of stem cells and their characterization in terms of site of residence, differentiation potential and therapeutic prospective. In fact, while only the bone marrow was initially considered as a “reservoir” of this cell population, later, adipose tissue and muscle tissue have provided a considerable amount of cells available for multiple differentiation. In reality, recently, the so-called “stem cell niche” was identified as the perivascular space, recognizing these cells as almost ubiquitous. In the field of bone and joint diseases, their potential to differentiate into multiple cell lines makes their application ideally immediate through three main modalities: (1) cells selected by withdrawal from bone marrow, subsequent culture in the laboratory, and ultimately transplant at the site of injury; (2) bone marrow aspirate, concentrated and directly implanted into the injury site; (3) systemic mobilization of stem cells and other bone marrow precursors by the use of growth factors. The use of this cell population in joint and bone disease will be addressed and discussed, analysing both the clinical outcomes but also the basic research background, which has justified their use for the treatment of bone, cartilage and meniscus tissues.  相似文献   
27.
28.
Breast cancer is the most common cause of cancer death in women in this country. Until recently, the traditional treatment has been radical surgery with or without radiation therapy for patients with primary breast cancer, and palliative endocrine therapy followed by chemotherapy for patients with advanced disease. These treatments have met with limited effectiveness in terms of eradicating the disease. Studies in the past decade have given cause for optimism for breast cancer patients. Adjuvant systemic therapy after local treatment appears promising for certain subsets of patients with primary breast cancer. The development of estrogen receptor assays has markedly changed our approach to the disease and improved patient care. Estrogen receptor is an important prognostic factor and is useful in planning appropriate therapy for patients with primary breast cancer as well as those with advanced disease. Further research is urgently needed to improve the dismal survival of certain women with this common malignancy.  相似文献   
29.
This study focused on the substantia nigra (SN) in Parkinson’s disease (PD). We measured its area and volume, mean diffusivity (MD), fractional anisotropy (FA) and iron concentration in early and late PD and correlated the values with clinical scores. Twenty-two early PD (EPD), 20 late PD (LPD) and 20 healthy subjects (age 64.7 ± 4.9, 60.5 ± 6.1, and 61 ± 7.2 years, respectively) underwent 1.5 T MR imaging with double-TI-IR T1-weighted, T2*-weighted and diffusion tensor imaging scans. Relative SN area, MD, FA and R2* were measured in ROIs traced on SN. Correlation with Unified Parkinson Disease Rating Scale (UPDRS) scores was assessed. In LPD, the SN area was significantly reduced with respect to EPD (p = 0.04) and control subjects (p < 0.001). In EPD, the SN area was also significantly smaller than in controls (p = 0.006). Similarly, the SN volume significantly differed between LPD and controls (p = 0.001) and between EPD and LPD (p = 0.049), while no significant differences were found between controls and EPD. Both SN area (r = 0.47, p = 0.004) and volume (r = 0.46, p = 0.005) correlated with UPDRS scores. At 1.5 T, SN morphological measurements were sensitive to early PD changes and able to track the disease progression, while MD and FA measures and relaxometry did not provide significant results.  相似文献   
30.
The aim of this study was to determine the coreceptor tropism by performing genotypic HIV-1 tropism testing in a cohort of patients perinatally infected with HIV-1 and exposed to antiretroviral therapy. Genotypic coreceptor tropism was determined in patients with HIV-1 RNA<100 copies/mL using PBMC samples by gp120 V3 sequencing followed by geno2pheno interpretation (set at a false positive rate [FPR] of 20%) and in patients with >100 copies/mL using plasma samples (set at a FPR of 20%), according to European guidelines. Out of 55 patients, 50 had an HIV-1 subtype B strain, and mean (SD) age was 18.2 (4.6) years. The median duration of antiretroviral therapy was 13 years (range, 3–23). Thirty-three (60%) patients harbored the R5 virus. At the time of the testing, the median CD4+ T lymphocyte cell count and percentage were 705 cells/mm3 (474–905) and 32.5% in group R5 and 626 cells/mm3 (450–755) and 31.7% in group X4/D-M, respectively. The nadir of CD4+ T-cell count in groups R5 and X4/D-M were 322 cells/mm3 (230–427) and 340 cells/mm3 (242–356), respectively. These differences were not statistically significant. Fifteen patients had HIV-1 RNA >50 copies/mL. The median HIV-1 RNA and HIV-1 DNA were comparable in both groups without a statistical difference. The study provides an overview of the prevalence of coreceptor tropism in a cohort of patients who were vertically infected with HIV-1. The high prevalence of X4/D-M-tropic strains may simply reflect the long-term exposure to HIV.  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