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   8032篇
  免费   545篇
  国内免费   21篇
耳鼻咽喉   83篇
儿科学   238篇
妇产科学   168篇
基础医学   1014篇
口腔科学   626篇
临床医学   947篇
内科学   1497篇
皮肤病学   143篇
神经病学   652篇
特种医学   175篇
外科学   781篇
综合类   48篇
一般理论   2篇
预防医学   1114篇
眼科学   169篇
药学   512篇
中国医学   32篇
肿瘤学   397篇
  2023年   62篇
  2022年   70篇
  2021年   242篇
  2020年   184篇
  2019年   230篇
  2018年   284篇
  2017年   173篇
  2016年   213篇
  2015年   283篇
  2014年   354篇
  2013年   422篇
  2012年   619篇
  2011年   707篇
  2010年   383篇
  2009年   252篇
  2008年   488篇
  2007年   511篇
  2006年   452篇
  2005年   450篇
  2004年   377篇
  2003年   335篇
  2002年   304篇
  2001年   119篇
  2000年   103篇
  1999年   88篇
  1998年   54篇
  1997年   41篇
  1996年   47篇
  1995年   32篇
  1994年   32篇
  1993年   39篇
  1992年   48篇
  1991年   46篇
  1990年   30篇
  1989年   25篇
  1988年   24篇
  1987年   18篇
  1986年   30篇
  1985年   28篇
  1984年   26篇
  1983年   28篇
  1982年   26篇
  1981年   19篇
  1980年   27篇
  1979年   17篇
  1978年   14篇
  1977年   15篇
  1975年   15篇
  1974年   15篇
  1971年   14篇
排序方式: 共有8598条查询结果,搜索用时 15 毫秒
1.
2.
3.
Objective:The present study evaluates a training program for fitting different hearing protection devices (HPDs) based on personal attenuation rating (PAR) before, immediately after, and six months after training.Methods:A total of 67 workers from a public university in the city of São Paulo, Brazil, were invited to participate in the measurement of PARs for foam and silicone protectors through the 3M™ E-A-Rfit Validation System. Two evaluations were performed for each protector at each sampling date: one after reading printed material (the package instructions) and another after being trained by an audiologist. The same procedures were repeated after six months. The final sample consisted of 30 individuals. ANOVA was used for statistical analysis.Results:Larger PAR values were observed after training by the audiologist, and smaller values were observed after six months. Then, after re-training, the values increased again. There were no statistically significant differences in PAR among the HPDs tested. Even after the two training sessions, 23 to 27% of the subjects did not obtain adequate PAR values.Conclusion:These findings emphasize the need for continual worker training in the correct fit of earplug HPDs and the importance of longitudinal PAR monitoring. In addition, some workers, despite the training provided, did not adapt to the HPDs used. Therefore, it is essential that other protection methods and/or other HPD types are made available to these individuals.Key words: Hearing, noise-induced hearing loss, occupational health, personal protective equipment, hearing protection devices  相似文献   
4.
Background and aimsThe long-term relations between excessive adiposity in early childhood and unfavourable cardiometabolic profiles in later ages are not yet completely understood. We aimed to assess the associations between birth weight (BW) and BMI from 6 months to 6 years of age, with biomarkers indicative of low-grade inflammation, insulin resistance and lipid profiles in adolescence.Methods and resultsRetrospective school-based study with 415 Portuguese adolescents (220 girls), mean age of 14.08 ± 1.6 years old. Anthropometric data from birth to 6 years old was extracted from individual child health book records. Actual weight and height were measured and BMI calculated. Participants were classified at each time point as normal weight or overweight according to WHO reference values. Biomarkers were obtained from venous blood samples. Linear regressions were used to explore the associations between the biomarkers and early life anthropometric indicators. From 2 years onwards, BMI associated positively with the inflammatory score and HOMA-IR in adolescence. Children who were overweight/obese from 2 to 6 years of age presented significantly higher inflammatory score and HOMA-IR later in adolescence. TC/HDL ratio was also positively associated with BMI from the age of 5 years onwards. The associations between BMI and cardiometabolic outcomes remained positive in adolescence, with overweight adolescents presenting a higher inflammatory score, HOMA-IR and TC/HDL than normal weight adolescents.ConclusionA high BMI from an early age was consistently associated with worse inflammatory and lipid profiles and insulin resistance in adolescence. No associations were found between BW and the same studied outcomes.  相似文献   
5.
6.
Drug‐induced reactions are complications associated with high mortality and significant morbidity. Stevens–Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN) are examples of these conditions, which are characterized by skin and mucous lesions. Here, we report a case of a 9‐year‐old girl who presented with blisters associated with an extensive vesicular rash and multiple ulcerations on the lips and oral cavity. A drug‐induced hypersensitivity reaction to antibiotics was suspected, and a diagnosis of TEN was made. The patient was managed with withdrawal of the suspected causative agent, and the oral lesions were treated with low‐level laser therapy (LLLT) and oral hygiene. This case highlights that TEN requires interdisciplinary intervention with dental assistance and follow‐up to improve symptoms, nutrition, systemic condition, and quality of life.  相似文献   
7.
8.
PURPOSE: Recommendations of the interdisciplinary Safe Medication Use Expert Committee of the United States Pharmacopeia (USP) to assist health care professionals, manufacturers, and organizations in handling neuromuscular blocking agents (NMBAs) safely and effectively are discussed. SUMMARY: Review and analysis of the USP Medication Errors Reporting Program and MEDMARX program databases showed a continuing risk of patient harm or death due to errors with NMBAs. Medication errors involving wrong concentrations, wrong doses, wrong drugs, look-alike packaging, and sound-alike names, combined with lack of monitoring and communication, have been associated with the use of NMBAs in health care institutions. Serious adverse events occur when NMBAs are used without adequate safeguards. Recommendations for improving safety were developed through review and discussion of root causes and areas of concern with these medications. CONCLUSION: Medical errors with NMBAs continue to result in patient morbidity and mortality. Increased awareness and action on the part of all parties involved are needed to improve the safety of this class of medications.  相似文献   
9.
With the recent introduction of preterm birth prevention programs there has been a shift in our understanding of what the presence of contractions during pregnancy means and a reconstituting of risk in ways that position increasing numbers of women at risk for preterm birth. This paper highlights the findings of a study exploring the influences of risk discourses on women's experiences of preterm labour. The primary goals of this institutional ethnographic study were to describe the effects of societal discourses, institutional structures, and nursing work processes on the everyday lives of childbearing women experiencing preterm labour. The findings suggest that risk discourses exert social control over pregnant women and result in fear, guilt, feelings of being judged or punished, and an overwhelming sense of personal responsibility for preventing preterm birth.The study also exposes ways in which biomedical constructions of risk and preterm labour affect the organization of health services, including nursing practice.  相似文献   
10.
PURPOSE: The aim of this study was to determine the reproducibility of measurements made using the Sonogage Corneo-Gage Plus 2 (Cleveland, Ohio) ultrasound pachymeter of total corneal and corneal epithelial thickness in 5 different regions of the cornea. METHODS: Twenty-seven subjects at the New England College of Optometry (NECO) and 20 subjects at the Southern College of Optometry (SCO) were enrolled in this study. Measurements were taken of the central cornea as well as the nasal and temporal regions of the midperipheral and peripheral regions of the right cornea of each subject. Identical measurements were again taken in these subjects 1 week later at approximately the same time of day. Within-subject variations were then assessed using paired t tests. RESULTS: The only significant measurement differences that were found between visits were for full corneal thickness at both the nasal and temporal midperipheral locations. The mean differences for these locations were 13.5 microm and 13.7 microm, respectively. CONCLUSIONS: Epithelial corneal thickness and central and peripheral total corneal thickness measurements using the Corneo-Gage Plus 2 pachymeter were reproducible; however, midperipheral total corneal thickness measurements showed poor reproducibility.  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