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   2387篇
  免费   64篇
  国内免费   18篇
耳鼻咽喉   94篇
儿科学   31篇
妇产科学   113篇
基础医学   265篇
口腔科学   39篇
临床医学   162篇
内科学   752篇
皮肤病学   12篇
神经病学   215篇
特种医学   56篇
外科学   260篇
综合类   12篇
预防医学   99篇
眼科学   60篇
药学   197篇
肿瘤学   102篇
  2023年   7篇
  2022年   80篇
  2021年   154篇
  2020年   32篇
  2019年   58篇
  2018年   78篇
  2017年   35篇
  2016年   42篇
  2015年   42篇
  2014年   87篇
  2013年   96篇
  2012年   161篇
  2011年   178篇
  2010年   105篇
  2009年   54篇
  2008年   137篇
  2007年   175篇
  2006年   159篇
  2005年   170篇
  2004年   134篇
  2003年   155篇
  2002年   117篇
  2001年   26篇
  2000年   34篇
  1999年   13篇
  1998年   5篇
  1997年   6篇
  1996年   4篇
  1995年   4篇
  1994年   3篇
  1993年   6篇
  1992年   11篇
  1990年   6篇
  1989年   6篇
  1988年   7篇
  1987年   3篇
  1986年   3篇
  1984年   6篇
  1980年   2篇
  1979年   5篇
  1978年   5篇
  1977年   4篇
  1974年   7篇
  1973年   8篇
  1972年   6篇
  1971年   4篇
  1970年   9篇
  1969年   3篇
  1967年   5篇
  1966年   2篇
排序方式: 共有2469条查询结果,搜索用时 234 毫秒
71.

Introduction

CD36 plays an important role in long-chain fatty acid homeostasis in skeletal muscle and the myocardium. CD36 deficiency may lead to reduced myocardial uptake of long-chain fatty acid. Therefore, different mutations of the CD36 gene may contribute to the clinical heterogeneity of cardiac hypertrophy.

Material and methods

The objective of the study was to investigate whether there is an association between the sequence changes in CD36 and echocardiographic and electrocardiographic parameters in Caucasian patients with early onset coronary artery disease. The study group comprised 100 patients. Electrocardiography and echocardiography were performed in all patients. Amplicons of exons 4 to 6 including fragments of introns were studied using the denaturing high-performance liquid chromatography technique.

Results

IVS3-6TC (rs3173798) heterozygotes had impaired left ventricle diastolic function. 573GA heterozygotes (rs5956) had higher frequency of pseudonormal left ventricular diastolic function and it was confirmed by the increase in wave A’ in the tissue Doppler. 591AT genotype was associated with borderline higher posterior wall end-diastolic thickness and lower E/A ratio. These results are consistent with electrocardiography parameters which could reflect left ventricular hypertrophy (higher RV5(6) and RV5(6) + SV1(2) parameters, depressed ST segments and tendency to longer Qtc II interval) in 591AT heterozygotes.

Conclusions

Detected variant alleles of CD36 may be associated with features of left ventricular hypertrophy and impaired diastolic function.  相似文献   
72.
The targeted treatment of advanced non-small-cell lung cancer (NSCLC) depends on confirmation of activating somatic EGFR mutation. The aim of the study was to evaluate the incidence of EGFR mutations in NSCLC detected in cytological and histological material and present literature review on European EGFR mutation incidence. 273 patients with confirmed NSCLC were entered into the study: 189 histological, paraffin-embedded materials, 12 fresh and 72 fixed cytological specimens. DNA was extracted from both types of material and the EGFR mutation in exons 18-21 was analyzed by direct sequencing. In addition the EGFR gene copy number in cases with sufficient histological material (110 patients) was evaluated by fluorescent in situ hybridization (FISH) technique. The percentage of EGFR somatic mutations was 10.62%. FISH positive results (amplification or high polysomy of EGFR gene) were identified in 33 patients (30.0%). The strongest clinicopathological correlation with the EGFR mutation was found for histological type (adenocarcinoma; p < 0.01), gender (females; p < 0.01) and FISH positive result (p < 0.05). This is the first, single institution study that estimates the EGFR mutation incidence in the Polish population. Cytological material recovered from fixed preparations and stained with hematoxylin and eosin showed DNA quality comparable to fresh tumor cells and histological samples.  相似文献   
73.
We present the case of a 72-year-old male with chronic phase myeloid leukemia. Elevation of the pulmonary artery pressure due to nilotinib therapy was noted. This effect on pulmonary artery pressure was nilotinib dose dependent.  相似文献   
74.
Exhaled breath condensate (EBC) contains extracellular DNA that may originate from pathological lesions of the respiratory tract and can be a genetic marker of pulmonary malignancy. We tested whether complete surgical excision of lung cancer will decrease exhalation of mutated KRAS oncogene. Fifty seven patients with clinical diagnosis of lung cancer and detectable KRAS mutations in pre-surgery EBC-DNA were qualified for surgical treatment. Point mutations at codon 12 of KRAS oncogene were detected using mutant-enriched PCR technique in DNA from pre-surgery blood, EBC collected before, 7 and 30 days after surgery and from specimens of resected tumor and normal pulmonary parenchyma. The ratio of mutated to wild type KRAS DNA (R mut/wild KRAS) was calculated for each specimen after electrophoresis and densitometry of the final amplification and digestion product. In 46 patients non-small cell lung cancer (NSCLC) and in 11 benign lesion (BL) were confirmed. All blood and tumor specimens were positive for KRAS mutations, while 41 specimens of normal pulmonary parenchyma were negative. In NSCLC patients pre-surgery EBC R mut/wild KRAS of 0.20?±?0.03 decreased by 1.3- and 3.7-times (p?相似文献   
75.
Circulating active tissue factor (TF) and activated factor XI (FXIa) have been detected in subgroups of acute coronary syndromes (ACSs) and stable angina patients. We sought to evaluate the determinants of active TF and FXIa in stable angina patients. We studied 124 consecutive stable angina patients. Recent ACS, atrial fibrillation, and anticoagulant therapy were the exclusion criteria. Plasma active TF and FXIa were determined by measuring the response to inhibitory antibodies. T helper 1 lymphocyte (Th1) and Th2 responses were assessed in plasma by interleukin (IL)-4, IL-6, IL-8, IL-10, IL-18, interferon-γ, and tumor necrosis factor-α, oxidative stress by 8-isoprostaglandin F(2α) (8-iso-PGF(2α)), and coagulation by prothrombin fragments F1+2 (F1+2) and free TF pathway inhibitor (f-TFPI). TF and FXIa activity were detected in 25 (20.2%) and 49 (39.5%) stable angina patients, respectively. Both factors were found in 23 (18.5%) patients. Patients with detectable TF or FXIa had higher F1+2, 8-iso-PGF(2α), IL-6, but not other cytokines, and lower f-TFPI (all P < 0.001) compared with the remainder. There were no intergroup differences with regard to cardiovascular risk factors or medication. Multivariate analysis showed that F1+2 and f-TFPI were the only independent predictors of the TF presence, whereas 8-iso-PGF(2α) and F1+2 predicted the presence of FXIa in stable angina patients. In stable angina patients, circulating active TF and FXIa are associated with enhanced thrombin formation, with a minor effect of inflammatory mediators. Moreover, FXIa is also related to oxidative stress, indicating additional links between coagulation and free radical generation in stable angina.  相似文献   
76.
77.

Purpose

This single center prospective cohort study evaluated the influence of hemihepatectomy on glucose homeostasis.

Methods

The study included 30 patients undergoing hemihepatectomy. All patients underwent an oral 75 g glucose tolerance test before (baseline), 1 week and 1 month after the surgery. Plasma glucose, insulin and glucagon were measured in the OGTT samples, and the HOMA index was calculated. The fasting levels of interleukin 6 and 1β, tumor necrosis factor and adiponectin were assessed.

Results

The fasting plasma and 120-min post-challenge mean glucose level increased during the study from 89.6 to 103.5 mg/dl (by 15.5 %) and from 136.4 to 162.2 (by 18.9 %; p = 0.51), respectively, accompanied by an increase in fasting glucagon (from 3.2 to 5.9 ng/mL; p = 0.043) and insulin (from 14.6 to 19.3 IU/mL) and by a decrease in plasma insulin at 60 min of OGTT (p = 0.34). An increase of IL-6 (p = 0.015) and TNF (from 49.7 to 53 pg/mL), and decrease of plasma APO (7658 to 5152 ng/mL) and exacerbation of insulin resistance (p = 0.007) were noted.

Conclusion

Hemihepatectomy resulted in moderate disturbances in glucose homeostasis, in a majority of patients that was likely to be of minor clinical relevance. However, the patients might be at higher risk of developing overt diabetes following long-term survival.  相似文献   
78.

Purpose

The aim of the study was to assess bone graft incorporation after revision hip arthroplasty in patients with rheumatoid arthritis (RA).

Methods

We report an acetabular reconstruction using impacted, morselized, frozen, radiation sterilized bone allografts in 71 patients suffering from RA. There were sixty-six women and five men at a mean age of 57.5 years. Reconstruction was performed in 78 revision total hip arthroplasties (THAs) for aseptic loosening of acetabular component. The mean follow-up was five years and four months. In 38 cases, a revision was done with use of reinforcement devices.

Results

In four revised hips (10 %) without reinforcement implants, resorption of the allografts was noticed. All Mueller rings and 50 % of unscrews cages (Link, Howmedica) were revised because of aseptic loosening and bone graft resorption. In all of 17 hips with the Burch-Schneider cage, no measurable migration or bone allografts resorption occurred. There were no major general complications.

Conclusions

Acetabular reconstruction with use of morselized, frozen, radiation sterilized bone allografts and the Burch-Schneider cage can be highly successful in managing massive deficiency of acetabular bone stock in revision hip arthroplasty in RA patients.  相似文献   
79.
Background and purposeThe common treatment in patients with newly diagnosed glioblastoma multiforme is the ultimately radical surgical removal of the tumour combined with radiotherapy. This study compared safety and efficacy of radiotherapy alone with radiotherapy combined with temozolomide (TMZ) given before, during, and after radiotherapy.Material and methodsThe patients operated on for glioblastoma multiforme during the first 21 postoperative days were randomly assigned to the group treated with radiotherapy alone (involved-field radiotherapy in 2 Gy fractions daily five times a week up to the total of 60 Gy over 6 weeks of treatment) or to the group treated with radiotherapy and TMZ, initially in the dose of 200 mg/m2 during 5 postoperative days and after 23 days followed by 75 mg/m2 of body surface area daily, 7 days a week (from the first to the last day of radiotherapy). On completion of radiotherapy, five complementary courses of TMZ were introduced (150–200 mg/m2 for 5 days, repeated every 28 days). The primary outcome measure was overall survival.ResultsFifty-eight patients from 3 centres were included in the study. The mean age of patients was 55 years and all the patients underwent a surgical procedure of glioblastoma removal. The mean overall survival in the group treated with TMZ was 16.0 months, whereas in the group with radiotherapy alone the overall survival reached 12.5 months. 24-month survival reached 23% in patients treated with TMZ and 6.7% in those who received radiotherapy only. Haematological complications of third or fourth degree were present in 10% of patients treated with radiotherapy and TMZ.ConclusionsThe introduction of TMZ before, during and after radiotherapy for newly diagnosed glioblastoma multiforme gives clinically and statistically significant improvement of survival with unremarkably increased toxicity of the treatment.  相似文献   
80.

Introduction

Embryonal tumor with abundant neuropil and true rosettes (ETANTR) is a rare subtype of primitive neuroectodermal tumors first reported in 2000. It is rare among the group of embryonal central nervous system tumors with approximately 50 reported cases. ETANTR has been suggested to be a separate entity among this group of tumors.

Case report

Herein, we present only the second autopsy case of ETANTR, which occurred in a 17-month-old boy, and was located in the brainstem. The tumor was inoperable, and despite chemotherapy, the child died 3 months after initial hospitalization. A brain only autopsy was performed.

Discussion

Neuropathological and neuroimaging examinations suggest ETANTR grew by expansion rather than invasion distorting anatomical structures of the posterior fossa. We suggest that the characteristic histopathological picture of the tumor is the result of multifocal and dispersed germinative activity surrounded by mature neuropil-like areas.

Conclusion

ETANTR is a pediatric tumor occurring in children under 4 with a significantly poor prognosis with more cases and research required to characterize this rare embryonal tumor.  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