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   2007篇
  免费   139篇
  国内免费   11篇
耳鼻咽喉   18篇
儿科学   58篇
妇产科学   31篇
基础医学   197篇
口腔科学   224篇
临床医学   161篇
内科学   533篇
皮肤病学   62篇
神经病学   103篇
特种医学   55篇
外科学   260篇
综合类   7篇
预防医学   185篇
眼科学   69篇
药学   120篇
中国医学   16篇
肿瘤学   58篇
  2023年   15篇
  2022年   48篇
  2021年   65篇
  2020年   46篇
  2019年   91篇
  2018年   100篇
  2017年   67篇
  2016年   70篇
  2015年   75篇
  2014年   98篇
  2013年   115篇
  2012年   158篇
  2011年   152篇
  2010年   72篇
  2009年   65篇
  2008年   117篇
  2007年   90篇
  2006年   104篇
  2005年   82篇
  2004年   95篇
  2003年   62篇
  2002年   51篇
  2001年   39篇
  2000年   26篇
  1999年   34篇
  1998年   9篇
  1997年   7篇
  1996年   9篇
  1995年   7篇
  1994年   6篇
  1993年   8篇
  1992年   25篇
  1991年   14篇
  1990年   15篇
  1989年   10篇
  1988年   15篇
  1987年   6篇
  1986年   9篇
  1985年   9篇
  1984年   5篇
  1983年   8篇
  1982年   7篇
  1975年   4篇
  1974年   5篇
  1973年   3篇
  1971年   4篇
  1970年   5篇
  1968年   5篇
  1966年   5篇
  1965年   3篇
排序方式: 共有2157条查询结果,搜索用时 15 毫秒
61.
62.
63.

Purpose

Malignant gliomas are associated with alteration in EGF/EGFR signaling. Functional EGF+61A>G polymorphism is implicated with risk, recurrence, and progression of glioma. This study aimed to establish a putative association of EGF+61A>G with risk of glioma development, production of angiogenic growth factor EGF, and the response to perillyl alcohol administered by intranasal route.

Methods

The study included 83 patients with recurrent glioma enrolled in Phase I/II trial for intranasal perillyl alcohol therapy and subjects without cancer (n?=?196) as control group. DNA was extracted from blood samples, EGF genotype performed with PCR–RFLP assay, and EGF circulating levels by enzyme immunoassay. Adequate statistical tests were performed to verify associations between polymorphism and glioma risk, and genotype correlation with EGF circulating levels. The log-rank test was also used to evaluate differences on patient survival.

Results

Patients with primary glioblastoma had high frequency of AA genotype (p?=?0.037) and A allele (p?=?0.037). Increased EGF circulating levels were observed in glioma patients with AA (p?=?0.042), AG (p?=?0.006), and AA?+?AG (p?=?0.008) genotypes compared with GG. Patients with GG genotype showed increased but not significant (p?>?0.05) survival rate, and EGF levels lower than 250?pg/mL was consistently (p?=?0.0374) associated with increased survival.

Conclusion

Presence of EGF+61A>G polymorphism in Brazilian subjects was associated with glioma risk and increased circulating EGF levels. Better response to perillyl alcohol-based therapy was observed in a group of adult Brazilian subjects with lower EGF levels.  相似文献   
64.
The research for peripheral biological markers of schizophrenia, although abundant, has been unfruitful. In the last 2 decades, the S100B protein has made its own room in this area of research. S100B is a calcium‐binding protein that has been proposed as a marker of astrocyte activation and brain dysfunction. Research results on S100B concentrations and schizophrenia clinical diagnosis are very consistent; patients with schizophrenia have higher S100B concentrations than healthy controls. The results regarding schizophrenia subtypes and clinical characteristics are not as conclusive. Age of patients, body mass index, illness duration and age at onset have been found to show no correlation, a positive correlation or a negative correlation with S100B levels. With respect to psychopathology, S100B data are inconclusive. Positive, negative and absence of correlation between S100B concentrations and positive and negative psychopathology have been reported. Methodological biases, such as day/night and seasonal variations, the use of anticoagulants to treat biological samples, the type of analytical technique to measure S100B and the different psychopathological scales to measure schizophrenia symptoms, are some of the factors that should be taken into account when researching into this area in order to reduce the variability of the reported results. The clinical implications of S100B changes in schizophrenia remain to be elucidated.  相似文献   
65.
66.

OBJECTIVE:

Previous studies have demonstrated a relationship between brain oxidative stress and cardiovascular regulation. We evaluated the effects of central catalase inhibition on cardiovascular responses in spontaneously hypertensive rats exposed to sidestream cigarette smoke.

METHODS:

Male Wistar Kyoto (WKY) rats and spontaneously hypertensive rats (SH) (16 weeks old) were implanted with a stainless steel guide cannula leading into the fourth cerebral ventricle (4th V). The femoral artery and vein were cannulated for arterial pressure and heart rate measurement and drug infusion, respectively. The rats were exposed to sidestream cigarette smoke for 180 minutes/day, 5 days/week for 3 weeks (CO: 100-300 ppm). The baroreflex was tested using a pressor dose of phenylephrine (8 μg/kg, bolus) and a depressor dose of sodium nitroprusside (50 μg/kg, bolus). Cardiovascular responses were evaluated before and 5, 15, 30 and 60 minutes after injection of a catalase inhibitor (3-amino-1,2,4-triazole, 0.001 g/100 μL) into the 4th V.

RESULTS:

Vehicle administration into the 4th V did not affect the cardiovascular response, whereas administration of the central catalase inhibitor increased the basal HR and attenuated the bradycardic peak (p<0.05) to a greater extent in WKY rats exposed to sidestream cigarette smoke than in WKY rats exposed to fresh air. However, in spontaneously hypertensive rats, the effect of the catalase inhibitor treatment was stronger in the fresh air condition (p<0.05).

CONCLUSION:

Administration of a catalase inhibitor into the 4th V combined with exposure to sidestream cigarette smoke has a stronger effect in WKY rats than in SH rats.  相似文献   
67.
68.
Objective: To assess sleep bruxism prevalence and its association with circadian preference and sleep-related characteristics among dental students.

Methods: Dental students of the Federal University of Minas Gerais participated in this cross-sectional study. Participants answered a scale assessing individuals' circadian preference, and a questionnaire regarding sleep-related characteristics and behaviors, history of muscle ache in the temporomandibular area, and history of bruxism.

Results: One hundred fifty-two students participated in the study. Sleep bruxism was reported by 11.3%. Most students (63.2%) were classified as intermediary, 34.9% as morningness, and 1.3% as eveningness. Individuals who reported muscle ache in the temporomandibular area in the morning (PR = 3.5; 95% CI = 1.1–11.5) were more likely to be in the group with sleep bruxism.

Conclusion: Muscle ache in the temporomandibular area is an important associated factor with sleep bruxism among dental students. Special attention should be paid to dental students’ circadian preference.  相似文献   
69.
70.
IntroductionWe evaluated the reproducibility of video endoscopic inguinal lymphadenectomy (VEIL) and we report our initial experience in the treatment of penile cancer with palpable inguinal lymph nodes.Material and methodsFrom July 2006 to November 2010 were conducted 33 VEIL in 20 patients as complementary treatment for penile cancer in two referral hospitals in Latin America. We analyzed the epidemiological and clinical characteristics of patients and surgical and oncologic outcomes.ResultsFifty-five percent of the patients included were clinical stage N0 and 45% were N +. Thirteen patients underwent bilateral VEIL and the remaining seven underwent VEIL unilateral and conventional open surgery in the contralateral limb. The average operative time for VEIL was 119 minutes and mean resected lymph nodes was 8 per lymphadenectomy. The overall complication rate was 33.2%. No patient had skin necrosis. The lymphatic complication rate was 27.2%. Of the 6 cases in which the saphenous vein was preserved (18.2%) there were no lymphatic complications (P = ,2). The overall survival rate was 80% and cancer-specific survival was 90%. Mean follow-up was 20 months.ConclusionsVEIL in the adjunctive treatment of penile cancer is safe, reproducible and may be an alternative to conventional lymphadenectomy. Patients with palpable lymphadenopathy also may benefit from this technique. Oncological results seem to be adequate however require longer follow-up to be confirmed.  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