全文获取类型
收费全文 | 1211篇 |
免费 | 138篇 |
国内免费 | 64篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 64篇 |
妇产科学 | 9篇 |
基础医学 | 123篇 |
口腔科学 | 30篇 |
临床医学 | 109篇 |
内科学 | 271篇 |
皮肤病学 | 24篇 |
神经病学 | 85篇 |
特种医学 | 259篇 |
外科学 | 68篇 |
综合类 | 64篇 |
预防医学 | 149篇 |
眼科学 | 7篇 |
药学 | 105篇 |
肿瘤学 | 41篇 |
出版年
2022年 | 12篇 |
2021年 | 18篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 11篇 |
2017年 | 17篇 |
2016年 | 21篇 |
2015年 | 18篇 |
2014年 | 22篇 |
2013年 | 35篇 |
2012年 | 21篇 |
2011年 | 32篇 |
2010年 | 24篇 |
2009年 | 32篇 |
2008年 | 24篇 |
2007年 | 52篇 |
2006年 | 30篇 |
2005年 | 39篇 |
2004年 | 23篇 |
2003年 | 22篇 |
2002年 | 15篇 |
2001年 | 31篇 |
2000年 | 17篇 |
1999年 | 24篇 |
1998年 | 59篇 |
1997年 | 64篇 |
1996年 | 66篇 |
1995年 | 60篇 |
1994年 | 36篇 |
1993年 | 48篇 |
1992年 | 23篇 |
1991年 | 26篇 |
1990年 | 37篇 |
1989年 | 59篇 |
1988年 | 54篇 |
1987年 | 45篇 |
1986年 | 25篇 |
1985年 | 34篇 |
1984年 | 18篇 |
1983年 | 16篇 |
1982年 | 18篇 |
1981年 | 20篇 |
1980年 | 24篇 |
1979年 | 22篇 |
1978年 | 9篇 |
1977年 | 16篇 |
1976年 | 16篇 |
1975年 | 13篇 |
1974年 | 13篇 |
1967年 | 6篇 |
排序方式: 共有1413条查询结果,搜索用时 15 毫秒
71.
Dr. Peter J. Silk Christopher M. Riley Charles J. Wiesner 《Archives of environmental contamination and toxicology》1988,17(5):631-636
A method is described for the colorimetric determination of fenitrothion spray deposit on conifer foliage. The technique is suitable for rapid deposit determination in the field using a portable mini-spectrophotometer. The detection limit is approximately 0.5 g fenitrothion/g foliage, although this could be improved. The technique is used in conjunction with gas chromatography to examine the evaporation and absorption dynamics of fenitrothion deposits on balsam fir foliage. 相似文献
72.
R G Rees J J Payne-James C King D B Silk 《JPEN. Journal of parenteral and enteral nutrition》1988,12(5):469-472
Certain groups of patients requiring enteral nutritional support are at increased risk of regurgitation and pulmonary aspiration of feed. Positioning of enteral feeding tubes distal to the pylorus has been advocated as a method of reducing such complications. Various techniques have been suggested to achieve postpyloric siting. Reports have indicated that lengthening the tube or altering the distal end tip configuration, by varying the tip profile or by the addition of a weight, may facilitate spontaneous transpyloric passage of the tube. This prospective controlled clinical study using three new polyurethane tubes demonstrates that the frequency of spontaneous transpyloric passage of the tube is not affected by tip profile or by the addition of a weight. Indeed, with all three tube designs only about one-third had passed spontaneously through the pylorus at 24 hr. Once through the pylorus the unweighted tube stayed in position significantly longer than the weighted tubes (p less than 0.005). We suggest that in those patients requiring post-pyloric feeding, endoscopic or fluoroscopic techniques should be used to position the tubes at the time of insertion, and that an unweighted tube should be used to prolong tube usage. 相似文献
73.
Kami J. Silk Samantha A. Nazione Kristin Pace Jan Collins-Eaglin 《Journal of health communication》2017,22(2):135-142
Suicide is a leading cause of death for college-aged youth, and university counseling centers (UCC) strive to educate students about mental health issues and available campus services. The current research evaluates a college campus social norms campaign that used both peer and celebrity sources to promote help seeking among college students as a suicide prevention strategy. Postcampaign surveys of this quasi-experiment (n = 391) revealed that compared to students in the control neighborhood condition, students exposed to the campaign messages in the experimental neighborhood conditions were more likely to perceive students would refer a friend to the UCC and more likely to visit the UCC for a mental health concern. Students living in the intervention neighborhood with a peer message source reported a greater willingness to refer friends to the UCC compared to those who lived in the celebrity and control neighborhoods. Regardless of condition, students who reported seeing UCC messages reported greater effects than those who reported not viewing the messages (e.g., greater intentions to seek help and to talk to others about the UCC). Results of this study are discussed within a social norms framework and support the need for continued exposure to campaign messages to impact health outcomes. 相似文献
74.
Michael M. Criss Amanda Sheffield Morris Elisabeth Ponce‐Garcia Lixian Cui Jennifer S. Silk 《Family relations》2016,65(3):517-529
The current study examined pathways to adolescent anger and sadness regulation in low‐income families. The sample included 206 families with adolescents age 10–18 years. Using a multimethod, multi‐informant approach, we assessed neighborhood violence, mutual emotional support, parental emotion coaching, and anger and sadness regulation. The findings indicated that high levels of mutual emotional support and emotion coaching and low levels of neighborhood violence were correlated with adolescent emotion regulation. In addition, the analyses demonstrated multiple pathways to emotion regulation. Specifically, neighborhood violence was directly and indirectly related to anger and sadness regulation. Moreover, mutual emotional support was indirectly related to emotion regulation via emotion coaching. Overall, there was little evidence of adolescent sex and age differences in the model. Implications regarding the socialization of adolescent emotion regulation are discussed. 相似文献
75.
目的 肺炎是全球传染性疾病最主要的死因之一,但中国的肺炎疾病负担还知之甚少,因为很多数据资料都是以非英文文献的形式发表的.方法 系统回顾了中国大陆关于肺炎发病率与死亡率的中文和英文文献,这些研究都是具有第一手数据的研究,1985-2008年有37篇论文符合纳入标准.结果 各项研究的质量差异较大.5岁以下儿童肺炎发病率为... 相似文献
76.
S Kanungo BK Sah AL Lopez JS Sung AM Paisley D Sur JD Clemens G Balakrish Nair 《Bulletin of the World Health Organization》2010,88(3):185-191
Objective
To more accurately define the annual incidence of cholera in India, believed to be higher than reported to the World Health Organization (WHO).Methods
We searched the biomedical literature to extract data on the cases of cholera reported in India from 1997 to 2006 and compared the numbers found to those reported annually to WHO over the same period. The latter were obtained from WHO’s annual summaries of reported cholera cases and National health profile 2006, published by India’s Central Bureau of Health Intelligence.Findings
Of India’s 35 states or union territories, 21 reported cholera cases during at least one year between 1997 and 2006. The state of West Bengal reported cases during all 10 years, while the state of Maharashtra and the union territory of Delhi reported cases during nine, and Orissa during seven. There were 68 outbreaks in 18 states, and 222 038 cases were detected overall. This figure is about six times higher than the number reported to WHO (37 783) over the same period. The states of Orissa, West Bengal, Andaman and Nicobar Islands, Assam and Chhattisgarh accounted for 91% of all outbreak-related cases.Conclusion
The reporting of cholera cases in India is incomplete and the methods used to keep statistics on cholera incidence are inadequate. Although the data are sparse and heterogeneous, cholera notification in India is highly deficient. 相似文献77.
78.
Linda R. Stanley Kimberly A. Miller Fred Beauvais Patricia Silk Walker R. Dale Walker 《Journal of child & adolescent substance abuse》2013,22(2):101-108
This study examines predictors of alcohol use disorders (AUDs) among an urban American Indian cohort who were followed from approximately age 11 to age 20. Approximately 27% of the sample had a lifetime diagnosis of alcohol abuse or dependence. The results indicated that externalizing, but not internalizing, behaviors, family conflict, and school liking served as significant predictors of an AUD. Neither having an alcoholic mother nor an alcoholic father was found to be significantly predictive of an alcohol use disorder at ages 19 and 20. Finally, early alcohol initiation was a substantial predictor of an AUD and acted as a partial mediator. 相似文献
79.
Genetically modified (GM) foods are currently a controversial topic about which the lay public in the United States knows little. Formative research has demonstrated that the lay public is uncertain and concerned about GM foods. This study (N = 858) extends focus group research by using the Theory of Reasoned Action (TRA) to examine attitudes and subjective norms related to GM foods as a theoretical strategy for audience segmentation. A hierarchical cluster analysis revealed four unique audiences based on their attitude and subjective norm toward GM foods (ambivalent-biotech, antibiotech, biotech-normer, and biotech individual). Results are discussed in terms of the theoretical and practical significance for audience segmentation. 相似文献
80.
目的和方法目前尚不清楚,摄入非水溶性钙盐的钙吸收是否比摄入水溶性差的钙盐钙吸收更好;另外也不清楚,牛奶制品的钙吸收是否比钙盐钙吸收更好。作者采用一种单次服用就能精确测定钙的净吸收率的方法,给8例健康空腹受试者服用含500mg钙的5种不同水溶性的钙盐和牛奶,服用顺序是随机的。结果按钙盐的水溶性递减次序排列,以平均钙的净吸收率±标准误表示:醋酸钙(32±4)%,乳酸钙(32±4)%,葡萄糖酸钙(27±3)%,柠檬酸钙(30±3)%;碳酸钙(39±3)%。按方差分析,钙盐和牛奶的钙吸收率差异无统计学意义… 相似文献