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   677篇
  免费   55篇
  国内免费   6篇
耳鼻咽喉   8篇
儿科学   21篇
妇产科学   29篇
基础医学   112篇
口腔科学   18篇
临床医学   37篇
内科学   212篇
皮肤病学   18篇
神经病学   45篇
特种医学   15篇
外科学   89篇
综合类   5篇
预防医学   50篇
眼科学   9篇
药学   30篇
中国医学   5篇
肿瘤学   35篇
  2023年   9篇
  2022年   4篇
  2021年   24篇
  2020年   14篇
  2019年   23篇
  2018年   21篇
  2017年   12篇
  2016年   13篇
  2015年   25篇
  2014年   35篇
  2013年   27篇
  2012年   54篇
  2011年   43篇
  2010年   28篇
  2009年   19篇
  2008年   42篇
  2007年   46篇
  2006年   37篇
  2005年   38篇
  2004年   29篇
  2003年   21篇
  2002年   27篇
  2001年   10篇
  2000年   22篇
  1999年   18篇
  1998年   7篇
  1997年   5篇
  1996年   8篇
  1995年   7篇
  1992年   8篇
  1991年   4篇
  1990年   3篇
  1989年   5篇
  1988年   3篇
  1987年   2篇
  1986年   3篇
  1985年   2篇
  1984年   3篇
  1982年   3篇
  1981年   2篇
  1980年   2篇
  1977年   3篇
  1975年   2篇
  1974年   3篇
  1973年   3篇
  1972年   2篇
  1969年   4篇
  1967年   3篇
  1966年   2篇
  1961年   3篇
排序方式: 共有738条查询结果,搜索用时 740 毫秒
1.
Hepatocellular carcinoma (HCC) is the most frequent primary liver cancer and presents together with cirrhosis in most cases. In addition to commonly recognized risk factors for HCC development, such as hepatitis B virus/hepatitis C virus infection, age and alcohol/tobacco consumption, there are nutritional risk factors also related to HCC development including high intake of saturated fats derived from red meat, type of cooking (generation of heterocyclic amines) and contamination of foods with aflatoxins. On the contrary, protective nutritional factors include diets rich in fiber, fruits and vegetables, n-3 polyunsaturated fatty acids and coffee. While the patient is being evaluated for staging and treatment of HCC, special attention should be paid to nutritional support, including proper nutritional assessment and therapy by a multidisciplinary team. It must be considered that these patients usually develop HCC on top of long-lasting cirrhosis, and therefore they could present with severe malnutrition. Cirrhosis-related complications should be properly addressed and considered for nutritional care. In addition to traditional methods, functional testing, phase angle and computed tomography scan derived skeletal muscle index-L3 are among the most useful tools for nutritional assessment. Nutritional therapy should be centered on providing enough energy and protein to manage the increased requirements of both cirrhosis and cancer. Supplementation with branched-chain amino acids is also recommended as it improves response to treatment, nutritional status and survival, and finally physical exercise must be encouraged and adapted to individual needs.  相似文献   
2.
3.
The oral-motor function of 10 infants with Turner syndrome and their age- and sex-matched controls were assessed during feeding. In addition to well-recognised dysmorphic features, including oral anomalies and high-arched palates, index infants had marked hypotonia of the cheeks and lips, dysfunctional tongue movements and poorly developed chewing skills. Their meal-times were significantly shorter than those of the controls and they weighed significantly less at six, 12 and 15 months. All mothers of infants with Turner syndrome complained of difficulties feeding their children and these problems often had been present since birth.  相似文献   
4.
The variability in plasma and urine equine procaine measurement between three independent laboratories using current methods led to the development of a sensitive, reliable, and reproducible high-performance liquid chromatographic method. Standardbred mares were administered either a penicillin G procaine preparation intramuscularly or procaine hydrochloride subcutaneously, and blood and urine were collected at defined time intervals. By HPLC the detection limits for procaine in plasma and urine were 1 and 10 ng/mL, respectively. In contrast procaine in plasma could not be detected by GC-NPD, while the urinary detection limit was 50 ng/mL. The concentration of fluoride in the collection tubes and repetitive freeze-thawing modified plasma procaine measurement. Urinary pH was a factor in estimation of urine procaine levels with greater recovery and reproducibility of results at pH 5 as compared to pH 7. This HPLC method provides a simple, sensitive, and reliable quantitation of procaine in equine plasma and urine.  相似文献   
5.
6.
7.
In a slum community in northeastern Brazil 20% of a sample population was colonized with Entamoeba histolytica or Entamoeba dispar and 10.6% was colonized with E. histolytica alone. No correlation between seropositivity for anti-GalNAc lectin antibody and colonization was found. These results suggest that colonization does not necessarily produce immunity to reinfection.  相似文献   
8.
The R337H TP53 mutation is a low-penetrance molecular defect that predisposes to adrenocortical tumour (ACT) formation in Brazilian and possibly other populations. Additional genetic defects may be responsible for the variable expression of ACTs in these cases. The inhibin α-subunit gene (INHA) on 2q33-qter has been implicated in mouse adrenocortical tumourigenesis. We studied 46 pediatric patients with ACTs from Brazil for INHA genetic alterations; 39 of these patients were heterozygous carriers of the R337H TP53 mutation. We first mapped the INHA gene by radiation hybrid analysis and determined 10 linked microsatellite markers in an area flanked by D2S1371 and D2S206 on 2q33-qter. These markers were then used for loss of heterozygozity (LOH) studies in nine paired germline and tumour DNA samples. Mapping placed the INHA gene in close proximity to D2S2848 (SHGC11864) with a log of odds (LOD) score of 5.84. LOH for at least one marker in the region was identified in 8/9 tumours (89%). Six patients were heterozygous for three INHA mutations: one in exon 1, 127C>G, and two in exon 2, 3998G>A and 4088G>A, all leading to amino acid substitutions (P43A, G227R, and A257T, respectively). A257T is located in a conserved INHA region, highly homologous to transforming growth factor-ß; both G227R and A257T change polarity, and, in addition, G227R changes the pH. We conclude that these sequence alterations and the detected 2q allelic changes suggest that INHA may be one of the contributing factors needed for ACT formation in pediatric patient carriers of the R337H TP53 mutation.  相似文献   
9.
AimThe aim of this study is to present our experience in the management of hormonally active adrenal tumors in children.Material and methodsWe did a retrospective chart review of all children with hormonally active adrenal tumors evaluated at the endocrinology clinic and operated at our institution between 1983 and 2019.ResultsThere were 75 patients included in the study, 58 with adrenocortical tumors (ACTs) and 17 with pheochromocytomas (PCCs). Within the group of patients with ACTs, there were 41 females and 17 males. The mean age was 58.3 (SD: 87.9; range: 9–211) months. The clinical manifestation of the tumor's hormonal activity was virilization in 37 cases, Cushing syndrome in 5, and mixed in 16. A positive family history was present in 11 patients (18.9%). The mean tumor size was 48.2 (SD: 22.4; range: 7–120) mm. The pathological diagnosis was adenoma in 42 cases, carcinoma in 15 cases, and macronodular hyperplasia in 1. Median follow-up was 192 (range: 50–290) months. Tumor recurrence occurred in 6 patients (10.3%), and there were three disease-related deaths (5%). Within the group of patients with PCCs, there were 11 males and 6 females. The mean age was 146.7 (SD: 71.2; range: 60–216) months. A positive family history was present in 7 patients (41.2%). The mean tumor size was 36.6 (SD: 16.7; range: 7–120) mm. The pheochromocytoma was classified as benign in 15 cases and as malignant in 2. During a median follow-up of 180 (range: 127–300) months, recurrence was observed in 6 cases (35.3%) and disease-related death in 1 case (5.9%).ConclusionsProper diagnosis and management at our referral center were associated with a high cure rate, even in cases of malignant tumors. Familial surveillance is highly recommended.Level of evidenceLevel IV.  相似文献   
10.
Chronic rhinosinusitis is a disease of undefined etiology that significantly impacts the quality of life of its patients. Various studies carried out in countries other than Brazil have shown endoscopic sinus surgery as an effective means of treating this condition.ObjectiveThis study aims to analyze, with the aid of SNOT-20, the association between endoscopic sinus surgery and disease-specific quality of life of Brazilian patients treated for chronic rhinosinusitis accompanied or not by nasal polyps.Materials and MethodsThis prospective study enrolled patients submitted to endoscopic sinus surgery after drug therapy failed to improve their symptoms. They were assessed based on questionnaire SNOT-20p before and 12 months after surgery. Improvement on total scores and on the five items deemed more important by each patient were assessed. The study also looked into the correlation between preoperative scores and postoperative improvement and if there were any gender-related improvement differences.ResultsForty-three patients aged 44 (19), md (IQR), 65% of whom (26/43) were males. Statistically significant improvement was seen on SNOT-20 and SNOT-20(5+) and a correlation was established between preoperative scores and postoperative improved scores (p<0.001). No gender-related differences were observed in quality of life.ConclusionEndoscopic sinus surgery in patients with chronic rhinosinusitis is associated with statistically significant improvements in disease-specific quality of life.  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