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   1690篇
  免费   114篇
  国内免费   9篇
耳鼻咽喉   18篇
儿科学   54篇
妇产科学   51篇
基础医学   286篇
口腔科学   43篇
临床医学   184篇
内科学   337篇
皮肤病学   41篇
神经病学   172篇
特种医学   14篇
外科学   106篇
综合类   14篇
一般理论   6篇
预防医学   191篇
眼科学   14篇
药学   115篇
中国医学   9篇
肿瘤学   158篇
  2023年   17篇
  2022年   5篇
  2021年   30篇
  2020年   22篇
  2019年   34篇
  2018年   42篇
  2017年   34篇
  2016年   51篇
  2015年   51篇
  2014年   69篇
  2013年   100篇
  2012年   129篇
  2011年   127篇
  2010年   75篇
  2009年   68篇
  2008年   99篇
  2007年   134篇
  2006年   108篇
  2005年   118篇
  2004年   89篇
  2003年   97篇
  2002年   86篇
  2001年   13篇
  2000年   5篇
  1999年   12篇
  1998年   15篇
  1997年   10篇
  1996年   10篇
  1995年   13篇
  1994年   10篇
  1993年   10篇
  1992年   10篇
  1991年   8篇
  1990年   4篇
  1989年   6篇
  1987年   4篇
  1985年   4篇
  1984年   5篇
  1983年   4篇
  1982年   6篇
  1981年   10篇
  1980年   7篇
  1979年   5篇
  1978年   5篇
  1977年   6篇
  1974年   3篇
  1973年   5篇
  1972年   4篇
  1968年   4篇
  1967年   4篇
排序方式: 共有1813条查询结果,搜索用时 15 毫秒
1.
2.
BACKGROUND Degree of portal hypertension(PH) is the most important prognostic factor for the decompensation of liver cirrhosis and death, therefore adequate care for patients with liver cirrhosis requires timely detection and evaluation of the presence of clinically significant PH(CSPH) and severe PH(SPH). As the most accurate method for the assessment of PH is an invasive direct measurement of hepatic venous pressure gradient(HVPG), the search for non-invasive methods to diagnose these conditions is actively ongoing.AIM To evaluate the feasibility of parameters of endogenously induced displacements and strain of liver to assess degree of PH.METHODS Of 36 patients with liver cirrhosis and measured HVPG were included in the casecontrol study. Endogenous motion of the liver was characterized by derived parameters of region average tissue displacement signal(dantero, dretro, d RMS) and results of endogenous tissue strain imaging using specific radiofrequency signal processing algorithm. Average endogenous strain μ and standard deviation σ of strain were assessed in the regions of interest(ROI)(1 cm × 1 cm and 2 cm × 2 cm in size) and different frequency subbands of endogenous motion(0-10 Hz and 10-20 Hz).RESULTS Four parameters showed statistically significant(P 0.05) correlation with HVPG measurement. The strongest correlation was obtained for the standard deviation of strain(estimated at 0-10 Hz and 2 cm × 2 cm ROI size). Three parameters showed statistically significant differences between patient groups with CSPH, but only dretro showed significant results in SPH analysis. According to ROC analysis area under the curve(AUC) of the σROI[0…10 Hz, 2 cm × 2 cm] parameter reached 0.71(P = 0.036) for the diagnosis of CSPH; with a cut-off value of 1.28 μm/cm providing 73% sensitivity and 70% specificity. AUC for the diagnosis of CSPH for μROI[0…10 Hz, 1 cm × 1 cm] was 0.78(P = 0.0024); with a cut-off value of 3.92 μm/cm providing 73% sensitivity and 80% specificity. Dretro parameter had an AUC of 0.86(P = 0.0001) for the diagnosis of CSPH and 0.84(P = 0.0001) for the diagnosis of SPH. A cut-off value of-132.34 μm yielded 100% sensitivity for both conditions, whereas specificity was 80% and 72% for CSPH and SPH respectively.CONCLUSION The parameters of endogenously induced displacements and strain of the liver correlated with HVPG and might be used for non-invasive diagnosis of PH.  相似文献   
3.
4.
Feline leukemia virus subgroup C receptor 1 (Flvcr1) encodes two heme exporters: FLVCR1a, which localizes to the plasma membrane, and FLVCR1b, which localizes to mitochondria. Here, we investigated the role of the two Flvcr1 isoforms during erythropoiesis. We showed that, in mice and zebrafish, Flvcr1a is required for the expansion of committed erythroid progenitors but cannot drive their terminal differentiation, while Flvcr1b contributes to the expansion phase and is required for differentiation. FLVCR1a-down-regulated K562 cells have defective proliferation, enhanced differentiation, and heme loading in the cytosol, while FLVCR1a/1b-deficient K562 cells show impairment in both proliferation and differentiation, and accumulate heme in mitochondria. These data support a model in which the coordinated expression of Flvcr1a and Flvcr1b contributes to control the size of the cytosolic heme pool required to sustain metabolic activity during the expansion of erythroid progenitors and to allow hemoglobinization during their terminal maturation. Consistently, reduction or increase of the cytosolic heme rescued the erythroid defects in zebrafish deficient in Flvcr1a or Flvcr1b, respectively. Thus, heme export represents a tightly regulated process that controls erythropoiesis.  相似文献   
5.
6.
Rheumatology International - Severe infections are common in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). We aimed to describe the characteristics of patients with AAV...  相似文献   
7.

OBJECTIVE:

To examine the pattern of tobacco use and knowledge about tobacco-related diseases, as well as to identify popular types of electronic media, in pregnant women, in order to improve strategies for the prevention or cessation of smoking among such women.

METHODS:

A cross-sectional study involving 61 pregnant women, seen at primary care clinics and at a university hospital, in the city of Botucatu, Brazil. For all subjects, we applied the Hospital Anxiety and Depression Scale. For subjects with a history of smoking, we also applied the Fagerström Test for Nicotine Dependence, and we evaluated the level of motivation to quit smoking among the current smokers.

RESULTS:

Of the 61 pregnant women evaluated, 25 (40.9%) were smokers (mean age, 26.4 ± 7.4 years), 24 (39.3%) were former smokers (26.4 ± 8.3 years), and 12 (19.8%) were never-smokers (25.1 ± 7.2 years). Thirty-nine women (63.9%) reported exposure to passive smoking. Of the 49 smokers/former smokers, 13 (26.5%) were aware of the pulmonary consequences of smoking; only 2 (4.1%) were aware of the cardiovascular risks; 23 (46.9%) believed that smoking does not harm the fetus or newborn infant; 21 (42.9%) drank alcohol during pregnancy; 18 (36.7%) reported increased cigarette consumption when drinking; 25 (51.0%) had smoked flavored cigarettes; and 12 (24.5%) had smoked a narghile. Among the 61 pregnant women evaluated, television was the most widely available and favorite form of electronic media (in 85.2%), as well as being the form most preferred (by 49.2%).

CONCLUSIONS:

Among pregnant women, active smoking, passive smoking, and alternative forms of tobacco consumption appear to be highly prevalent, and such women seem to possess little knowledge about the consequences of tobacco use. Educational programs that include information about the consequences of all forms of tobacco use, employing new and effective formats tailored to this particular population, should be developed, in order to promote smoking prevention and cessation among pregnant women. Further samples to explore regional and cultural adaptations should be evaluated.  相似文献   
8.
9.

Objectives

The aim of this study was to implement and evaluate the outcomes of chemotherapy counselling based on the “Managing Patients on Chemotherapy” module on self-esteem and psychological affect (anxiety, depression) of cancer patients by pharmacists in ten selected government hospitals in Peninsular Malaysia.

Methods

A randomized control trial was conducted among 2120 cancer patients from April 2016 to January 2017 in ten selected government hospitals in Peninsular Malaysia. Cancer patients were randomly assigned to intervention and control groups. The intervention group received chemotherapy counselling by pharmacists based on the “Managing Patients on Chemotherapy” module. The outcomes were assessed at baseline, 1st, 2nd and 3rd follow-ups after counselling. In the course of data analysis; independent sample t-test, chi-square and two-way repeated measures ANOVA were conducted.

Results

Mean scores of self-esteem in the intervention group had significant difference in comparison with those of the control group in the 1st, 2nd and 3rd follow-ups after counselling (P?<?0.0001). Also, among those with depression and anxiety at baseline, there was reduction in depression and anxiety scores after the 1st, 2nd and 3rd follow-ups after counselling (p?<?0.05).

Conclusion

Repetitive counselling by pharmacists based on the “Managing Patients on Chemotherapy” module had positive effect on improving self-esteem and psychological affect of cancer patients undergoing chemotherapy in Peninsular Malaysia.

Practice implications

This module can be used for all Malaysian cancer patients undergoing chemotherapy to improving self-esteem and psychological affect.  相似文献   
10.
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