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   563篇
  免费   28篇
  国内免费   9篇
耳鼻咽喉   1篇
儿科学   36篇
妇产科学   4篇
基础医学   44篇
口腔科学   18篇
临床医学   36篇
内科学   137篇
皮肤病学   8篇
神经病学   13篇
特种医学   84篇
外科学   76篇
综合类   63篇
预防医学   30篇
眼科学   9篇
药学   20篇
肿瘤学   21篇
  2024年   1篇
  2023年   2篇
  2022年   5篇
  2021年   7篇
  2020年   7篇
  2019年   3篇
  2018年   9篇
  2017年   6篇
  2016年   10篇
  2015年   18篇
  2014年   15篇
  2013年   20篇
  2012年   15篇
  2011年   11篇
  2010年   23篇
  2009年   33篇
  2008年   14篇
  2007年   20篇
  2006年   32篇
  2005年   8篇
  2004年   11篇
  2003年   3篇
  2002年   8篇
  2001年   12篇
  2000年   8篇
  1999年   14篇
  1998年   43篇
  1997年   31篇
  1996年   40篇
  1995年   17篇
  1994年   18篇
  1993年   22篇
  1992年   5篇
  1991年   8篇
  1990年   2篇
  1989年   9篇
  1988年   24篇
  1987年   9篇
  1986年   8篇
  1985年   17篇
  1984年   8篇
  1983年   4篇
  1982年   3篇
  1981年   3篇
  1980年   3篇
  1977年   3篇
  1976年   5篇
  1975年   3篇
排序方式: 共有600条查询结果,搜索用时 15 毫秒
591.
592.

Background

Sarcomatoid renal cell carcinoma (RCC) is associated with an aggressive biology and a poor prognosis. Poor-risk RCC is defined by clinical prognostic factors and demonstrates similarly aggressive behavior. No standard treatment exists for patients with sarcomatoid RCC, and treatment options for patients with poor-risk disease are of limited benefit. The objective of this study was to investigate the efficacy of antiangiogenic therapy in combination with cytotoxic chemotherapy in clinically aggressive RCC.

Methods

This was a phase 2, single-arm trial of sunitinib and gemcitabine in patients with sarcomatoid or poor-risk RCC. The primary end point was the objective response rate (ORR). Secondary end points included the time to progression (TTP), overall survival (OS), safety, and biomarker correlatives.

Results

Overall, 39 patients had sarcomatoid RCC, and 33 had poor-risk RCC. The ORR was 26% for patients with sarcomatoid RCC and 24% for patients with poor-risk RCC. The median TTP and OS for patients with sarcomatoid RCC were 5 and 10 months, respectively. For patients with poor-risk disease, the median TTP and OS were 5.5 and 15 months, respectively. Patients whose tumors had>10% sarcomatoid histology had a higher clinical benefit rate (ORR plus stable disease) than those with≤10% sarcomatoid histology (P = 0.04). The most common grade 3 or higher treatment-related adverse events included neutropenia (n = 20), anemia (n = 10), and fatigue (n = 7).

Conclusions

These results suggest that antiangiogenic therapy and cytotoxic chemotherapy are an active and well-tolerated combination for patients with aggressive RCC. The combination may be more efficacious than either therapy alone and is currently under further investigation.  相似文献   
593.

Background  

C. difficle spores in the environment of patients with C. difficile associated disease (CDAD) are difficult to eliminate. Bleach (5000 ppm) has been advocated as an effective disinfectant for the environmental surfaces of patients with CDAD. Few alternatives to bleach for non-outbreak conditions have been evaluated in controlled healthcare studies.  相似文献   
594.
Oral Diseases (2010) 16 , 769–773 Objective: The aim of this work was to determine the frequency and nature of oral manifestations secondary to use of cardiovascular drugs. Methods: Five hundred and thirty one patients attending an adult cardiology clinic in Saudi Arabia were questioned about the occurrence of oral dryness, dysgeusia, or burning sensation and were clinically evaluated for the presence of oral mucosal or gingival disease. Data were statistically analyzed with chi‐squared tests, odds ratios and Student’s t‐test. Results: Oral symptoms and/or signs were recorded in 75 (14.1%) patients with xerostomia being the most common (7.5%), followed by lichenoid (lichen planus‐like) lesions (3.6%) and dysgeusia (1.9%). Xerostomia was significantly more frequent in patients with a history of diabetes mellitus and in female patients (P < 0.05). There were no statistically significant differences (P > 0.05) between patients with or without oral manifestations when age, gender, cardiovascular risk factor, cardiac disease, type of cardiac drug used or the number of medications were assessed. There was a trend for xerostomia to be less frequent in patients receiving therapy with angiotensin converting enzyme inhibitors and a slight trend of xerostomia to be more likely with increased number of non‐cardiac and total number of agents per subject. The number of non‐cardiac and total medications taken by patients with potential oral manifestations tended to be greater than that of patients without oral manifestations. Conclusions: The frequency of potential oral manifestations in patients receiving cardiovascular agents was 14.1%. The occurrence and character of the oral manifestations had no significant relation with individual cardiac drugs, although there was a trend for oral manifestations to be likely with increasing number of drugs.  相似文献   
595.

Purpose

Mutations in the SNRNP200 gene have been reported to cause autosomal dominant retinitis pigmentosa (adRP). In this study, we evaluate the mutation profile of SNRNP200 in a cohort of southern Chinese RP patients.

Methods

Twenty adRP patients from 11 families and 165 index patients with non-syndromic RP with mixed inheritance patterns were screened for mutations in the mutation hotspots of SNRNP200. These included exons 12–16, 22–32, and 38–45, which covered the two helicase ATP-binding domains in DEAD-box and two sec-63 domains. The targeted regions were amplified by polymerase chain reaction and analyzed by direct DNA sequencing, followed by in silico analyses.

Results

Totally 26 variants were identified, 18 of which were novel. Three non-synonymous variants (p.C502R, p.R1779H and p.I698V) were found exclusively in patients. Two of them, p.C502R and p.R1779H, were each identified in one simplex RP patient, whereas p.I698V occurred in one patient with unknown inheritance pattern. All three residues are highly conserved in SNRNP200 orthologs. Nevertheless, only p.C502R and p.R1779H were predicted to affect protein function by in silico analyses, suggesting these two variants are likely to be disease-causing mutations. Notably, all mutations previously identified in other study populations were not detected in this study.

Conclusions

Our results reveal a distinct mutation profile of the SNRNP200 gene in a southern Chinese cohort of RP patients. The identification of two novel candidate mutations in two respective patients affirmed that SNRNP200 contributes to a proportion of overall RP.  相似文献   
596.
597.
ABSTRACT Introduction: To analyze the association between physical activity (PA) and occurrence of depressive symptoms in The Nord‐Trøndelag Health Survey (HUNT 1 1984–1986, HUNT 2 1995–1997). Methods: In this prospective follow‐up study, we studied men and women who were 21–40 years old in HUNT 1, and participated in HUNT 2. The sample consisted of 3,353 women and 3,308 men. We used logistic regression and calculated odds ratios (OR) to assess the association between physical activity and depression (Hospital Anxiety and Depression Scale depression subscale [HADS‐D]). Confounding was addressed by excluding those with relevant health conditions and adjustment. Results: Among women 272 (8.1%) and among men 293 (8.9%) scored higher than 8 on the HADS‐D scale. We found a higher mean on HADS‐D in men and women who were inactive. Men participating in low PA had significantly lower scores on depression (OR=0.63, confidence interval [CI]=0.43–0.93, p=.02) than inactive men. Women participating in medium PA had significantly lower scores on depression (OR=0.69, CI=0.49–0.97, p=.03) than inactive women. Conclusions: Young men and women who exercised were less likely to have a high depression score, compared with inactive people. Our prospective, observational study included a large population and indicated some significant associations between physical activity and depression.  相似文献   
598.

Background

Nasal modes of respiratory support cause variable amounts of gastric dilatation which may increase gastro-oesophageal reflux (GER) in preterms. To compare the incidence of GER in nasally ventilated, preterm babies with controls (babies not on ventilation). Type of study: A prospective, observational comparative study.

Method

Twenty-three preterm babies of gestational age 28–36 weeks and weight ranging between 1,000 g and < 2,500 g on either nasal continuous positive airway pressure (nCPAP) or nasal intermittent positive pressure venti-lation (nIPPV) were assessed for GER. They were compared with controls not on ventilation some of who were test babies when off ventilation (subgroup A) and some were unrelated babies not on ventilator but matched for gestational age and weight with test babies (subgroup B). All babies were subjected to continuous, oesophageal pH monitoring with dual sensor (upper and lower oesophageal) catheters. Reflux index (RI) was calculated as the percentage of study time the lower oesophageal pH was < 4. Primary outcome was the RI in the test and controls groups. Secondary outcome was the temporal relation of the reflux with symptoms if any. Numerical data were shown as mean with standard deviation and statistical comparisons were done using the χ2-test, Fischer test, and t-test wherever applicable.

Results

The RI was higher in ventilated babies as compared to the control group, particularly in the subgroup A, where test babies formed their own controls. Grade IV reflux (7 cases) was seen only in the ventilated babies. There was no difference in the incidence of GER in babies on nCPAP as compared with nIPPV. Grade IV reflux could not be reliably predicted by RI alone. No definite temporal relation between episodes of reflux and symptoms could be determined in this study.

Conclusion

There is an increase in GER in preterms on nasal modes of ventilation. A combination of upper (pharyngeal) and lower oesophageal sensors are preferred to a single lower oesophageal sensor when assessing GER by oesophageal pHmetry in neonates.  相似文献   
599.
600.

Background  

In Pakistan, only 59-73% of children 12-23 months of age are fully immunized. This randomized, controlled trial was conducted to assess the impact of a low-literacy immunization promotion educational intervention for mothers living in low-income communities of Karachi on infant immunization completion rates.  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