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   493篇
  免费   27篇
  国内免费   3篇
耳鼻咽喉   2篇
儿科学   26篇
妇产科学   2篇
基础医学   36篇
口腔科学   5篇
临床医学   27篇
内科学   111篇
皮肤病学   5篇
神经病学   20篇
特种医学   85篇
外科学   111篇
综合类   11篇
预防医学   21篇
眼科学   4篇
药学   27篇
中国医学   3篇
肿瘤学   27篇
  2023年   3篇
  2022年   2篇
  2021年   9篇
  2020年   10篇
  2019年   8篇
  2018年   16篇
  2017年   3篇
  2016年   5篇
  2015年   10篇
  2014年   17篇
  2013年   10篇
  2012年   26篇
  2011年   17篇
  2010年   21篇
  2009年   17篇
  2008年   17篇
  2007年   25篇
  2006年   18篇
  2005年   14篇
  2004年   17篇
  2003年   26篇
  2002年   7篇
  2001年   14篇
  2000年   18篇
  1999年   15篇
  1998年   13篇
  1997年   11篇
  1996年   18篇
  1995年   12篇
  1994年   12篇
  1993年   11篇
  1992年   10篇
  1991年   5篇
  1990年   5篇
  1989年   9篇
  1988年   8篇
  1987年   3篇
  1986年   4篇
  1985年   8篇
  1984年   7篇
  1983年   3篇
  1982年   6篇
  1981年   6篇
  1980年   3篇
  1977年   5篇
  1976年   9篇
  1975年   4篇
  1973年   1篇
  1970年   2篇
  1968年   1篇
排序方式: 共有523条查询结果,搜索用时 15 毫秒
11.
Aim:   Coronary artery calcification (CAC) has been associated with higher mortality in chronic renal disease. The purpose of this study was to assess coronary artery calcium score (CaCs) in haemodialysis patients and to correlate calcium scores with clinical parameters and mortality.
Methods:   A cross-sectional study was conducted in 59 haemodialysis patients. CaCs was assessed by multidetector-row computed tomography and stratified as: CaCs of less than 10 Agatston units (U), no calcification; CaCs of 10–400 U, mild-to-moderate; and CaCs of more than 400 U, severe calcification. The effects of age, haemodialysis duration and biochemical and inflammatory markers on CaCs logarithm were evaluated by multiple linear regression analysis. Cox regression analysis was used to measure the impact of CaCs of more than 400 on 2-year mortality.
Results:   Coronary calcifications were detected in 64.5% of patients, and the median of CaCs was 31.7 U (0–589.7) with a range of 0–5790.0 U. Twenty-one (35.5%) patients had mild-to-moderate and 17 (29%) severe CaCs. Patients with severe CaCs were older and showed a higher prevalence of ischaemic heart disease and a higher body mass index ( P  = 0.04). A trend towards higher C-reactive protein levels was found in patients with severe CaCs. Advanced age was the only variable that influenced CaCs logarithm independently. The effect of severe CaCs on 2-year mortality did not persist after adjustment for other covariates.
Conclusion:   Coronary calcification was highly prevalent in these uraemic patients on chronic haemodialysis. A correlation was evidenced between CaCs and advanced age, but severity of the CAC score did not have an impact on 2-year mortality of this cohort.  相似文献   
12.
Iatrogenic injury accounts for the second most common cause of acquired diaphragmatic hernias after penetrating trauma. An increased incidence of these hernias has been observed with the widespread use of laparoscopic surgery. We present the case of a 65-year-old woman who initially underwent sigmoid resection for an adenocarcinoma and a subsequent liver resection for metastasis. She was noted to have a left lower lobe pulmonary nodule on surveillance computed tomography, for which she underwent a mini-thoracotomy for a planned resection. At the time of surgery, the pulmonary nodule was discovered to be a diaphragmatic hernia, most probably of iatrogenic origin. We discuss the difficulty in diagnosis given her history and the location of such a lesion.  相似文献   
13.
14.
目的:探讨山奈酚能否通过调控肥胖小鼠脂肪组织炎症改善胰岛素抵抗发生并研究作用机制。方法:db/m小鼠作为对照组,db/db雄性小鼠随机分为模型组、二甲双胍组(0.15 g·kg-1·d-1)和山奈酚组(50 mg·kg-1·d-1)。连续灌胃给药6周,每周记录小鼠体重,6周后进行葡萄糖耐量试验、胰岛素耐量试验、皮下和附睾白色脂肪组织质量测定;HE染色观察脂肪组织形态学变化,免疫组化法观察巨噬细胞向脂肪组织的浸润程度及巨噬细胞标志物F4/80的表达,实时荧光定量PCR检测TNF-α和IL-18以及Arg-1和IL-10的mRNA表达,蛋白质免疫印迹试验检测NLRP3、pro-caspase1、cle-caspase1和IL-1β表达。结果:与模型组相比,山奈酚能够显著抑制db/db小鼠脂肪质量增加,抑制脂肪细胞肥大。山奈酚组小鼠脂肪组织巨噬细胞浸润减少,TNF-α和IL-18 mRNA表达减少,Arg-1和IL-10 mRNA表达增加;山奈酚治疗能够抑制小鼠附睾脂肪组织NLRP3、caspase1以及...  相似文献   
15.
16.
Height is a highly heritable and classic polygenic trait. Recent genome-wide association studies (GWAS) have revealed that at least 180 genetic variants influence adult height. However, these variants explain only about 10% of the phenotypic variation in height. Genetic analysis of short individuals can lead to the discovery of novel rare gene defects with a large effect on growth. In an effort to identify novel genes associated with short stature, genome-wide analysis for copy number variants (CNVs), using single-nucleotide polymorphism arrays, in 162 patients (149 families) with short stature was performed. Segregation analysis was performed if possible, and genes in CNVs were compared with information from GWAS, gene expression in rodents'' growth plates and published information. CNVs were detected in 40 families. In six families, a known cause of short stature was found (SHOX deletion or duplication, IGF1R deletion), in two combined with a de novo potentially pathogenic CNV. Thirty-three families had one or more potentially pathogenic CNVs (n=40). In 24 of these families, segregation analysis could be performed, identifying three de novo CNVs and nine CNVs segregating with short stature. Four were located near loci associated with height in GWAS (ADAMTS17, TULP4, PRKG2/BMP3 and PAPPA). Besides six CNVs known to be causative for short stature, 40 CNVs with possible pathogenicity were identified. Segregation studies and bioinformatics analysis suggested various potential candidate genes.  相似文献   
17.
目的研究姜黄素对匹罗卡品诱导的癫痫小鼠海马新生神经元和细胞凋亡的影响。方法姜黄素预处理后,小鼠腹腔注射匹罗卡品建立小鼠癫痫模型,应用新生神经元标记物双皮层蛋白(doublecortin,DCX)免疫组织化学染色及TUNEL染色对造模后72h的模型小鼠海马进行检测。结果 DCX免疫组织化学染色结果表明,与对照组相比,模型组及姜黄素处理模型组小鼠海马齿状回DCX阳性细胞明显减少;与模型组相比,姜黄素处理模型组小鼠海马齿状回DCX阳性细胞明显增多。TUNEL染色结果表明,与对照组相比,模型组及姜黄素处理模型组小鼠海马齿状回TUNEL阳性细胞明显增多;与模型组相比,姜黄素处理模型组小鼠海马齿状回TUNEL阳性细胞明显减少。结论姜黄素可能对匹罗卡品诱导的癫痫小鼠海马神经元有保护作用。  相似文献   
18.
Summary BACKGROUND: Endometriosis is a relatively common pathology in women of childbearing age and of low parity but rarely shows extraperitoneal involvement. The main aim of this paper is to raise the attention of specialists to the necessity of carrying out penetrating diagnosis of nonspecific extraperitoneal masses occurring in women of reproductive age. METHODS: We performed a retrospective review of six patients diagnosed with extraperitoneal endometriosis who were treated at the Vega Baja University Hospital (Spain) during the last 5 years. RESULTS: Surgical treatment had positive results in five patients. The preoperative diagnosis was correctly made in only two patients. The accurate aetiology of endometriosis remains unknown and diagnosis is based on clinical and cytopathological findings. CONCLUSIONS: Surgical treatment of extraperitoneal endometriosis is recommended. However, postoperative follow-up is obligatory and hormonal suppressive therapy may be necessary. Medical treatment with gestagens, Danazol, or agonists of the gonadotropin-releasing hormone are ineffective in endometriomas which are bigger than 2 cm.   相似文献   
19.
Meniscal tears of the knee: accuracy of MR imaging   总被引:39,自引:0,他引:39  
Crues  JV  d; Mink  J; Levy  TL; Lotysch  M; Stoller  DW 《Radiology》1987,164(2):445-448
Before surgery, 277 menisci in 144 knees were examined with magnetic resonance (MR) imaging. They were then examined directly with arthroscopy or arthrotomy. Menisci were graded on a scale of 1-3 according to the character of the intrameniscal MR imaging signal. At surgery, 137 of 154 (89%) menisci exhibiting only grade 1 or grade 2 signal were found to be normal. One hundred sixteen of 123 (94%) menisci exhibiting intrameniscal signal communicating with a meniscal articular surface (grade 3 signal) had tears. If only a grade 3 signal is considered consistent with meniscal tears, then MR findings and surgical findings agreed in 91.3% of menisci. MR imaging can separate surgically significant from nonsignificant meniscal lesions and is useful in the noninvasive preoperative screening of suspected meniscal tears.  相似文献   
20.
Technetium-99m sestamibi scintigraphy has become a valuable tool in locating parathyroid glands in patients with primary hyperparathyroidism. The aim of this study was to evaluate its usefulness in secondary hyperparathyroidism. Twenty patients were injected intravenously with 740 MBq of 99mTc-sestamibi and images were obtained at 15 min and 2 h post injection. All patients underwent parathyroid ultrasonography (US) as well as bilateral surgical neck exploration and 64 parathyroid glands were removed. US revealed at least one enlarged gland in 15/20 patients (75%), while 99mTc-sestamibi scintigraphy showed focal areas of increased uptake in at least one gland in 17/20 patients (85%). When imaging results for all glands were evaluated according to surgical results, sensitivity was 54% for parathyroid scintigraphy and 41% for US, and specificity was 89% for both imaging techniques. There was a discrepancy between the two imaging modalities in 28 glands (35%). The mean surgical weight of US-positive glands (1492±1436 mg) was significantly higher than that of US-negative glands (775±703 mg) (P<0.05). However, there were no significant differences in weight between sestamibi-positive and sestamibi-negative glands. When only sestamibi-positive glands were considered, a positive correlation between uptake and weight was found (r=0.4, P<0.05). In conclusion, parathyroid US and 99mTc-sestamibi scintigraphy are complementary imaging techniques in the preoperative localization of abnormal parathyroid glands in patients with secondary hyperparathyroidism. The limited sensitivity of the techniques means that patients will still require bilateral neck exploration; therefore routine preoperative parathyroid scanning in renal patients is not justified. Received 1 June and in revised form 6 August 1997  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