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   3804篇
  免费   226篇
  国内免费   8篇
耳鼻咽喉   66篇
儿科学   124篇
妇产科学   73篇
基础医学   471篇
口腔科学   96篇
临床医学   391篇
内科学   703篇
皮肤病学   87篇
神经病学   289篇
特种医学   97篇
外科学   534篇
综合类   67篇
一般理论   2篇
预防医学   460篇
眼科学   66篇
药学   288篇
中国医学   5篇
肿瘤学   219篇
  2023年   20篇
  2022年   37篇
  2021年   85篇
  2020年   52篇
  2019年   65篇
  2018年   69篇
  2017年   49篇
  2016年   59篇
  2015年   83篇
  2014年   82篇
  2013年   124篇
  2012年   218篇
  2011年   214篇
  2010年   151篇
  2009年   113篇
  2008年   178篇
  2007年   184篇
  2006年   161篇
  2005年   144篇
  2004年   138篇
  2003年   130篇
  2002年   123篇
  2001年   100篇
  2000年   106篇
  1999年   93篇
  1998年   50篇
  1997年   33篇
  1996年   40篇
  1995年   34篇
  1994年   37篇
  1993年   36篇
  1992年   69篇
  1991年   65篇
  1990年   54篇
  1989年   63篇
  1988年   64篇
  1987年   64篇
  1986年   60篇
  1985年   61篇
  1984年   41篇
  1983年   44篇
  1982年   24篇
  1981年   27篇
  1980年   21篇
  1979年   25篇
  1977年   20篇
  1976年   25篇
  1975年   22篇
  1974年   23篇
  1972年   19篇
排序方式: 共有4038条查询结果,搜索用时 15 毫秒
81.
ObjectiveTo investigate the relationship between TXNIP polymorphisms, diabetes and hypertension phenotypes in the Brazilian general population.MethodsFive hundred seventy-six individuals randomly selected from the general urban population according to the MONICA-WHO project guidelines were phenotyped for cardiovascular risk factors. A second, independent, sample composed of 487 family-trios from a different site was also selected. Nine TXNIP polymorphisms were studied. The potential association between TXNIP variability and glucose-phenotypes in children was also explored. TXNIP expression was quantified by real-time PCR in 53 samples from human smooth muscle cells primary culture.ResultsTXNIP rs7211 and rs7212 polymorphisms were significantly associated with glucose and blood pressure related phenotypes. In multivariate logistic regression models the studied markers remained associated with diabetes even after adjustment for covariates. TXNIP rs7211 T/rs7212 G haplotype (present in approximately 17% of individuals) was significantly associated to diabetes in both samples. In children, the TXNIP rs7211 T/rs7212 G haplotype was associated with fasting insulin concentrations. Finally, cells harboring TXNIP rs7212 G allele presented higher TXNIP expression levels compared with carriers of TXNIP rs7212 CC genotype (p = 0.02).ConclusionCarriers of TXNIP genetic variants presented higher TXNIP expression, early signs of glucose homeostasis derangement and increased susceptibility to chronic metabolic conditions such as diabetes and hypertension. Our data suggest that genetic variation in the TXNIP gene may act as a “common ground” modulator of both traits: diabetes and hypertension.  相似文献   
82.
83.
84.
Obstructive apneas produce high negative intrathoracic pressure that imposes an afterload burden on the left ventricle. Such episodes might produce structural changes in the left ventricle over time. Doppler echocardiograms were obtained within 2 months of attended polysomnography. Patients were grouped according to apnea-hypopnea index (AHI): mild/no obstructive sleep apnea (OSA; AHI <15) and moderate/severe OSA (AHI ≥15). Mitral valve tenting height and area, left ventricular (LV) long and short axes, and LV end-diastolic volume were measured in addition to tissue Doppler parameters. Comparisons of measurements at baseline and follow-up between and within groups were obtained; correlations between absolute changes (Δ) in echocardiographic parameters were also performed. After a mean follow-up of 240 days mitral valve tenting height increased significantly (1.17 ± 0.12 to 1.28 ± 0.17 cm, p = 0.001) in moderate/severe OSA as did tenting area (2.30 ± 0.41 to 2.66 ± 0.60 cm(2), p = 0.0002); Δtenting height correlated with ΔLV end-diastolic volume (rho 0.43, p = 0.01) and Δtenting area (rho 0.35, p = 0.04). In patients with mild/no OSA there was no significant change in tenting height; there was a borderline significant increase in tenting area (2.20 ± 0.44 to 2.31 ± 0.43 cm(2), p = 0.05). Septal tissue Doppler early diastolic wave decreased (8.04 ± 2.49 to 7.10 ± 1.83 cm/s, p = 0.005) in subjects with moderate/severe OSA but not in in those with mild/no OSA. In conclusion, in patients with moderate/severe OSA, mitral valve tenting height and tenting area increase significantly over time. This appears to be related, at least in part, to changes in LV geometry.  相似文献   
85.
Abstract. An average of six annual rounds of ivermectin and albendazole were distributed in Plateau and Nasarawa States, Nigeria, to eliminate lymphatic filariasis. From 2007 to 2008, population-based surveys were implemented in all 30 local government areas (LGAs) of the two states to determine the prevalence of Wuchereria bancrofti antigenemia to assess which LGA mass drug administration (MDA) could be halted. In total, 36,681 persons from 7,819 households were examined for filarial antigen as determined by immunochromatographic card tests. Overall antigen prevalence was 3.05% (exact upper 95% confidence interval [CI] = 3.41%) with an upper 95% CI range by LGA of 0.50-19.3%. Among 3,233 children 6-7 years of age, overall antigen prevalence was 1.71% (exact upper 95% CI = 2.19%), too high to recommend generally halting MDA in the two-state area. However, based on criteria of < 2% antigenemia among persons > 2 years of age, stopping MDA was recommended for 10 LGAs.  相似文献   
86.
To study the prevalence and semiotic characteristics of neuropathic pain in the common low back pain to the Black African subject. This was a prospective cross-sectional survey carried on from April 1 2009 to August 31 2009 in consultations of rheumatology, neurology, and neurosurgery at the University Hospital Yalgado Ouédraogo in Ouagadougou (Burkina Faso). All patients with a low back pain or a common lomboradiculalgie were included. DN4 questionnaire was used for the diagnosis of neuropathic pain. One hundred and seven patients have been recruited during the study period; Sixty-four (59.80%) were female (sex ratio M/F: 0.67). The average age was 34.11?±?13.46?years of age with extremes of 20 and 79. The average duration of disease was 48.53?months with extremes of 10?days and 50?years. Eighty-seven patients (81.31%) had a disease duration, which was 3?months longer. Sixty-six patients (61.70%) had a predominant lomboradiculalgie; among the remaining 41, low back pain predominated. Average intensity of pain was 62.81?±?22.43 (on a scale of 100). A sign of Lasèque was present in the 41 (38.30%) patients. Fifty-three (49.5%) patients had a neuropathic pain. The prevalence of neuropathy signs according to the DN4 questionnaire was as follows: burning (n?=?37; 34.58%), painful cold (n?=?13; 12.15%), electric shocks (n?=?31; 38.97%), pins and needles (n?=?34; 31.77%), tingling (n?=?35; 32.71%), numbness (n?=?45; 42.05%), itching (n?=?18; 16.82%), touch hypoesthesia (n?=?35; 32.71%), pinprick (n?=?33; 30.84%), and tactile allodynia (n?=?21; 19.62%). Among the studied variables, the presence of a radiculalgy was statistically associated with neuropathic pain. The lomboradiculalgie of the Black African subject associates neuropathic pain observed in half of patients. Treatment must therefore always take account of this association. However, further studies are needed before any definitive conclusion.  相似文献   
87.
Genetic polymorphisms near IL28B are associated with spontaneous and treatment-induced clearance of hepatitis C virus (HCV), two processes that require the appropriate activation of the host immune responses. Intrahepatic inflammation is believed to mirror such activation, but its relationship with IL28B polymorphisms has yet to be fully appreciated. We analyzed the association of IL28B polymorphisms with histological and follow-up features in 2335 chronically HCV-infected Caucasian patients. Assessable phenotypes before any antiviral treatment included necroinflammatory activity (n = 1,098), fibrosis (n = 1,527), fibrosis progression rate (n = 1,312), and hepatocellular carcinoma development (n = 1,915). Associations of alleles with the phenotypes were evaluated by univariate analysis and multivariate logistic regression, accounting for all relevant covariates. The rare G allele at IL28B marker rs8099917-previously shown to be at risk of treatment failure-was associated with lower activity (P = 0.04), lower fibrosis (P = 0.02) with a trend toward lower fibrosis progression rate (P = 0.06). When stratified according to HCV genotype, most significant associations were observed in patients infected with non-1 genotypes (P = 0.003 for activity, P = 0.001 for fibrosis, and P = 0.02 for fibrosis progression rate), where the odds ratio of having necroinflammation or rapid fibrosis progression for patients with IL28B genotypes TG or GG versus TT were 0.48 (95% confidence intervals 0.30-0.78) and 0.56 (0.35-0.92), respectively. IL28B polymorphisms were not predictive of the development of hepatocellular carcinoma. CONCLUSION: In chronic hepatitis C, IL28B variants associated with poor response to interferon therapy may predict slower fibrosis progression, especially in patients infected with non-1 HCV genotypes.  相似文献   
88.
89.

Introduction

Descending necrotizing mediastinitis (DNM) is a serious infection which occurs as a complication of oropharyngeal infection. Its surgical management and the routine transthoracic approach remain controversial. In this article we report our experience in the management of this disease, and review the different surgical approaches that have been reported in the medical literature.

Material and methods

A retrospective review was made of the clinical records of 29 patients treated between 1988 and 2009. Several demographic variables were analyzed, origin of the initial infection, stage of the disease according to Endo's classification, surgical technique and outcome.

Results

Surgical treatment consisted of both cervical and mediastinal drainage and radical debridement. The mediastinal drainage was made through a transcervical approach in 10 cases and transthoracic in 19, depending on the extent of the mediastinitis. The outcome was satisfactory in 24 patients and 5 died (mortality 17.2%).

Conclusions

According to our results and the conclusions of the main authors, we recommend a prompt and aggressive surgery with a transthoracic approach in cases of widespread DNM.  相似文献   
90.
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