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   4520篇
  免费   205篇
  国内免费   14篇
耳鼻咽喉   105篇
儿科学   196篇
妇产科学   216篇
基础医学   691篇
口腔科学   33篇
临床医学   280篇
内科学   1000篇
皮肤病学   71篇
神经病学   423篇
特种医学   76篇
外科学   221篇
综合类   28篇
预防医学   375篇
眼科学   120篇
药学   594篇
中国医学   13篇
肿瘤学   297篇
  2024年   2篇
  2023年   24篇
  2022年   157篇
  2021年   305篇
  2020年   105篇
  2019年   138篇
  2018年   148篇
  2017年   129篇
  2016年   157篇
  2015年   159篇
  2014年   201篇
  2013年   294篇
  2012年   368篇
  2011年   380篇
  2010年   201篇
  2009年   151篇
  2008年   239篇
  2007年   312篇
  2006年   280篇
  2005年   266篇
  2004年   197篇
  2003年   196篇
  2002年   155篇
  2001年   19篇
  2000年   16篇
  1999年   14篇
  1998年   7篇
  1997年   12篇
  1996年   10篇
  1995年   6篇
  1992年   7篇
  1991年   4篇
  1990年   7篇
  1989年   6篇
  1988年   8篇
  1987年   5篇
  1986年   6篇
  1984年   2篇
  1983年   8篇
  1982年   5篇
  1981年   2篇
  1979年   3篇
  1978年   7篇
  1977年   5篇
  1976年   2篇
  1975年   3篇
  1974年   6篇
  1973年   1篇
  1972年   1篇
  1969年   1篇
排序方式: 共有4739条查询结果,搜索用时 31 毫秒
91.
Ecotoxicology - The bottom sediments in catchment areas behind dams play a significant role in water ecosystems. On the other hand, the structure of sediments makes them a natural geosorbent, in...  相似文献   
92.

Objectives

Protective vaccinations are the most effective method of prevention of type B virus hepatitis. The aim of the study was to determine whether in children receiving immunosuppressive therapy due to inflammatory systemic connective tissue diseases the protective concentration of the anti-HBs antibodies produced after vaccination against type B virus hepatitis in infancy is maintained.

Material and methods

The concentration of anti-HBs antibodies was assessed in the sera of 50 children with inflammatory connective tissue diseases – 37 girls (74%) and 13 boys (26%), aged 1.5–17.5 years – during the immunosuppressive treatment, which lasted at least 6 months. The control group consisted of 50 healthy children – 28 girls (56%) and 22 boys (44%) aged 2–17 years. All children were vaccinated in infancy with Engerix B vaccine according to the 0–1–6 months schedule. The antibody concentration of ≥ 10 mIU/ml in patients is regarded as protective.

Results

No protective antibody concentrations were found in 25 cases (50%) in the group of diseased children and only in 2 children in the control group (4%).

Conclusions

The concentration of vaccine-induced antibodies should be assessed in children with inflammatory systemic connective tissue diseases and, in case of the absence of a protective concentration, revaccination should be started. The use of glucocorticosteroids, synthetic and biological disease-modifying antirheumatic drugs is no contraindication to vaccination against hepatitis B.  相似文献   
93.
94.
OBJECTIVE: To study genotype-phenotype correlation for the 4 most common genotypes found among patients with familial Mediterranean fever (FMF). METHODS: Thirty patients with the M694V/M694V genotype, 32 with M694V/V726A genotype, 25 with M694V/E 148Q genotype, and 21 with V726A/V726A genotype were assessed for various clinical manifestations of FMF, and overall disease severity. RESULTS: Patients with the M694V/M694V genotype were found to have an earlier age of onset, higher frequency of joint involvement, higher frequency of erysipelas-like erythema, and required higher doses of colchicine to control the disease compared to the other 3 genotypes. CONCLUSION: The M694V/M694V genotype is associated with more severe disease compared to other common genotypes in patients with FMF.  相似文献   
95.

Aims

The level of C-peptide can identify individuals most likely to respond to immune interventions carried out to prevent pancreatic β-cell damage.The aim of the study was to evaluate factors associated with C-peptide levels at type 1 diabetes (T1D) diagnosis.

Methods

This study included 1098 children aged 2-17 with newly recognized T1D. Data were collected from seven Polish hospitals. The following variables were analyzed: date of birth, fasting C-peptide, HbA1c, sex, weight, height, pH at diabetes onset.

Results

A correlation was observed between fasting C-peptide level and BMI-SDS (p?=?0.0001), age (p?=?0.0001), and HbA1c (p?=?0.0001). The logistic regression model revealed that fasting C-peptide ≥0.7 ng/ml at diabetes diagnosis was dependent on weight, HbA1c, pH and sex (p?<?0.0001).Overweight and obese children (n?=?124) had higher fasting C-peptide (p?=?0.0001) and lower HbA1c (p?=?0.0008) levels than other subjects. Girls had higher fasting C-peptide (p?=?0.036) and higher HbA1c (p?=?0.026) levels than boys.

Conclusion

Obese and overweight children are diagnosed with diabetes at an early stage with largely preserved C-peptide levels. Increased awareness of T1D symptoms as well as improved screening and diagnostic tools are important to preserve C-peptide levels. There are noticeable gender differences in the course of diabetes already at T1D diagnosis.  相似文献   
96.
C-reactive protein as a marker of heart failure   总被引:1,自引:0,他引:1  
  相似文献   
97.
98.
Alpha-toxin (AT) is a major virulence determinant in Staphylococcus aureus skin and soft tissue infection models. We previously demonstrated that prophylactic administration of 2A3, an AT-neutralizing monoclonal antibody (MAb), prevents S. aureus disease in a mouse dermonecrosis model by neutralizing AT-mediated tissue necrosis and immune evasion. In the present study, MEDI4893*, an affinity-optimized version of 2A3, was characterized for therapeutic activity in the dermonecrosis model as a single agent and in combination with two frontline antibiotics, vancomycin and linezolid. MEDI4893* postinfection therapy was found to exhibit a therapeutic treatment window similar to that for linezolid but longer than that for vancomycin. Additionally, when combined with either vancomycin or linezolid, MEDI4893* resulted in reduced tissue damage, increased neutrophil and macrophage infiltration and abscess formation, and accelerated healing relative to those with the antibiotic monotherapies. These data suggest that AT neutralization with a potent MAb holds promise for both prophylaxis and adjunctive therapy with antibiotics and may be a valuable addition to currently available options for the treatment of S. aureus skin and soft tissue infections.  相似文献   
99.
[Purpose] The objective of this study was to evaluate the usefulness of pedometry and accelerometry in the measurement of the energy expenditures in Nordic walking and conventional walking as diagnostic parameters. [Subjects and Methods] The study included 20 female students (age, 24 ± 2.3 years). The study used three types of measuring devices, namely a heart rate monitor (Polar S610i), a Caltrac accelerometer, and a pedometer (Yamax SW-800). The walking pace at the level of 110 steps/min was determined by using a metronome. [Results] The students who walked with poles covered a distance of 1,000 m at a speed 36.3 sec faster and with 65.5 fewer steps than in conventional walking. Correlation analysis revealed a moderate interrelationship between the results obtained with a pedometer and those obtained with an accelerometer during Nordic walking (r = 0.55) and a high correlation during conventional walking (r = 0.85). [Conclusion] A pedometer and Caltrac accelerometer should not be used as alternative measurement instruments in the comparison of energy expenditure in Nordic walking.Key words: Nordic walking, Accelerometer, Energy expenditure  相似文献   
100.
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