全文获取类型
收费全文 | 28469篇 |
免费 | 2787篇 |
国内免费 | 919篇 |
专业分类
耳鼻咽喉 | 64篇 |
儿科学 | 1669篇 |
妇产科学 | 1001篇 |
基础医学 | 3582篇 |
口腔科学 | 328篇 |
临床医学 | 2338篇 |
内科学 | 4506篇 |
皮肤病学 | 190篇 |
神经病学 | 1259篇 |
特种医学 | 506篇 |
外国民族医学 | 3篇 |
外科学 | 1809篇 |
综合类 | 3180篇 |
现状与发展 | 5篇 |
一般理论 | 1篇 |
预防医学 | 3950篇 |
眼科学 | 241篇 |
药学 | 4228篇 |
11篇 | |
中国医学 | 1382篇 |
肿瘤学 | 1922篇 |
出版年
2024年 | 163篇 |
2023年 | 677篇 |
2022年 | 1372篇 |
2021年 | 1555篇 |
2020年 | 1253篇 |
2019年 | 1246篇 |
2018年 | 1093篇 |
2017年 | 1167篇 |
2016年 | 1198篇 |
2015年 | 1257篇 |
2014年 | 1831篇 |
2013年 | 2390篇 |
2012年 | 1625篇 |
2011年 | 1677篇 |
2010年 | 1319篇 |
2009年 | 1260篇 |
2008年 | 1352篇 |
2007年 | 1206篇 |
2006年 | 1016篇 |
2005年 | 1010篇 |
2004年 | 786篇 |
2003年 | 775篇 |
2002年 | 630篇 |
2001年 | 535篇 |
2000年 | 418篇 |
1999年 | 374篇 |
1998年 | 323篇 |
1997年 | 277篇 |
1996年 | 218篇 |
1995年 | 199篇 |
1994年 | 216篇 |
1993年 | 173篇 |
1992年 | 154篇 |
1991年 | 139篇 |
1990年 | 120篇 |
1989年 | 86篇 |
1988年 | 86篇 |
1987年 | 80篇 |
1986年 | 84篇 |
1985年 | 133篇 |
1984年 | 118篇 |
1983年 | 97篇 |
1982年 | 76篇 |
1981年 | 76篇 |
1980年 | 65篇 |
1979年 | 65篇 |
1978年 | 50篇 |
1977年 | 28篇 |
1976年 | 34篇 |
1973年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
目的:总结近年来蒲黄监督检验工作中发现的影响质量的主要问题,为蒲黄药材真伪鉴别、质量标准完善提供建议。方法:基于掺杂、增重、染色问题,采用性状鉴别、显微鉴别、杂质检查、总灰分检查及金胺O染色检查方法,分析检验过程中遇到的问题,探讨现行标准在质量控制中的可行性。结果与结论:试验结果可见掺杂、增重的样品必然伴随有染色问题,现行的质量标准在蒲黄掺杂、增重、染色方面有较为全面有效的检测手段,但在标准执行中常因问题错综复杂,而标准检验项目承接不明确,造成判定结论裁决困难的问题。建议细化蒲黄药材质量标准,增订草蒲黄的质量标准,完善蒲黄质量标准,并建立蒲黄炮制品(包括炒蒲黄和蒲黄炭)的质量标准,以便更全面地控制蒲黄药材质量。 相似文献
992.
Mary J. Christoph Katie A. Loth Marla E. Eisenberg Ann F. Haynos Nicole Larson Dianne Neumark-Sztainer 《Journal of nutrition education and behavior》2018,50(3):267-274.e1
Objective
Investigate the relationship between use of Nutrition Facts labels on packaged foods and weight-related behaviors.Design
Cross-sectional survey in 2015–2016.Participants
Young adult respondents (n?=?1,817; 57% women; average age 31.0?±?1.6 years) to the Project Eating and Activity in Teens and Young Adults–IV survey, the fourth wave of a longitudinal cohort study.Variables Measured
Use of Nutrition Facts labels on packaged foods; healthy, unhealthy, and extreme weight control behaviors; intuitive eating; binge eating.Analysis
Linear and logistic regression models were adjusted for age, ethnicity/race, education, income, and weight status.Results
In women, greater Nutrition Facts use was associated with a 23% and 10% greater likelihood of engaging in healthy and unhealthy weight control behaviors, respectively, and a 17% greater chance of engaging in binge eating. In men, greater label use was associated with a 27% and 17% greater likelihood of engaging in healthy and unhealthy weight control behaviors, respectively, and a lower level of intuitive eating.Conclusions and Implications
Professionals advising patients and clients on weight management may consider possible gender differences in response to weight loss and management guidance. Since label use was related to engagement in some unhealthy behaviors in addition to healthy behaviors, it is important to consider how individuals may use labels, particularly those at risk for, or engaging in, disordered eating behaviors. Future research investigating potential relationships between Nutrition Facts use, intuitive eating, and binge eating is needed. 相似文献993.
Rainer Wirth Maryam Pourhassan Melanie Streicher Michael Hiesmayr Karin Schindler Cornel Christian Sieber Dorothee Volkert 《Journal of the American Medical Directors Association》2018,19(9):775-778
Objectives
Dysphagia is a frequent finding in nursing home residents. The aim of this study is to evaluate the association of dysphagia and mortality in nursing home residents and identify further risk factors for mortality in residents with dysphagia.Design
One-day, annually repeated cross-sectional study, evaluating the nutritional situation of nursing home residents with 6-month mortality as outcome.Setting
191 nursing homes from 14 countries in Europe and the United States participating in the nutritionDay study between 2007 and 2012.Participants
Data of all nursing home residents in the nutritionDay study aged 65 years or older with available information about dysphagia and outcome were analyzed.Measurements
Residents’ characteristics and mortality rate were calculated by group comparison, and mortality risk was calculated by multivariate regression analysis with adjustment for potential confounding factors.Results
10,185 residents (78% female) with a mean age of 85 ± 8.1 years were included in the analysis. Dysphagia was reported in 15.4% of residents. The 6-month mortality of residents with dysphagia was significantly higher than of those without dysphagia (24.7% vs 11.9%; P < .001). The multivariate regression analysis revealed dysphagia [odds ratio (OR) 1.44, 95% confidence interval (CI) 1.24-1.68, P < .001] along with body mass index <20 (OR 1.78, 95% CI 1.55-2.03, P < .001) and weight loss >5 kg (OR 1.61, 95% CI 1.37-1.88, P < .001) as independent and significant risk factors for mortality. Because of significant interaction, a disproportionately high mortality of 38.9% was found in residents with dysphagia accompanied by previous weight loss >5 kg (OR for interaction 1.44; 95% CI 1.03-2.01; P = .032). Tube feeding was reported in 14.6% of residents with dysphagia. The mortality rate of dysphagic residents receiving tube feeding vs those who were not was not significantly different (21.4% vs 25.3%; P = .244).Conclusion
In this nutritionDay study, dysphagia was identified as an independent risk factor for mortality in nursing home residents. Residents with dysphagia accompanied by weight loss are at a particularly high risk of mortality and should therefore receive special attention. 相似文献994.
Molly E. Waring Tiffany A. Moore Simas Jessica Oleski Rui S. Xiao Julie A. Mulcahy Christine N. May Sherry L. Pagoto 《Journal of nutrition education and behavior》2018,50(1):70-74.e1
Objective
To evaluate the feasibility and acceptability of a Facebook-delivered postpartum weight loss intervention.Methods
Overweight and obese postpartum women received a 12-week weight loss intervention via Facebook. Feasibility outcomes were recruitment, retention, engagement, and acceptability. Weight loss was an exploratory outcome.Results
Participants (n?=?19) were 3.5 (SD 2.2) months postpartum with a baseline body mass index of 30.1 (SD 4.2) kg/m2. Retention was 95%. Forty-two percent of participants visibly engaged on the last day of the intervention, and 100% in the last 4 weeks; 88% were likely or very likely to participate again and 82% were likely or very likely to recommend the program to a postpartum friend. Average 12-week weight loss was 4.8% (SD 4.2%); 58% lost ≥5%.Conclusions and Implications
Findings suggested that this Facebook-delivered intervention is feasible and acceptable and supports research to test efficacy for weight loss. Research is needed to determine how best to engage participants in social network–delivered weight loss interventions. 相似文献995.
Carla Viegas Ann Marie Coggins Tiago Faria Liliana Aranha Caetano Anita Quintal Gomes Raquel Sabino 《International journal of environmental health research》2018,28(2):167-177
Fungi are amongst the bioaerosols of most importance, as indicated by the growing interest in this field of research. The aim was to characterize the exposure to fungal burden in podiatry clinics using culture-based and molecular methods. Methods: Airborne fungi were collected using an impaction air sampler and surface samples were also performed. Fourteen air samples were collected for direct detection of fungal DNA from filamentous fungi and dermatophytes. Overall, 63.6 % of the evening samples and 46 % of the morning samples surpassed the threshold values (150 CFU/m3). Molecular detection, by real time PCR, of the target fungal species/strains (Aspergillus and Stachybotrys species) was negative for all samples collected. Trichophyton rubrum was detected by PCR analysis in one DNA sample collected on day six. Results suggest the use of both culture-based and molecular methodologies are desirable for a complete evaluation of fungal burden in this particular health care setting. 相似文献
996.
Psychological effects of belonging to a Facebook weight management group in overweight and obese adults: Results of a randomised controlled trial 下载免费PDF全文
Monica Jane Jonathan Foster Martin Hagger Suleen Ho Robert Kane Sebely Pal 《Health & social care in the community》2018,26(5):714-724
This study was conducted to test whether the weight outcomes in an online social networking group were mediated by changes to psychological outcome measures in overweight and obese individuals, following a weight management programme delivered via Facebook. The data analysed in this study were collected during a three‐armed, randomised, controlled clinical weight management trial conducted with overweight and obese adults over 24 weeks. Two intervention groups were given the same weight management programme: one within a Facebook group, along with peer support from other group members (the Facebook Group); the other group received the same programme in a pamphlet (the Pamphlet Group). A Control Group was given standard care. The primary outcome was weight; secondary outcomes included the following domains from self‐reported questionnaires: energy intake and expenditure; psychological health, social relationships, physical health, quality of life, depression, anxiety, stress, health anxiety, happiness, as well as Facebook Group participants’ opinion of this group. The Facebook Group experienced a reduction in their baseline weight measurement by week 24, significantly compared to the Control Group (p = .016). The Facebook Group recorded a significant increase in the psychological health domain during the trial (at week 12) relative to their baseline measurement, and significant compared to the Control Group (p = .022). Mediation analysis indicated a statistical trend, but not statistical significance, for psychological health as a mediator to weight loss in the Facebook Group. While both intervention groups showed significant changes in psychological outcome measures, the Facebook Group was the only group to experience statistically significant weight loss by the end of the 24 weeks. Therefore, an examination of other psychological and/or behavioural outcome measures undertaken in larger studies in the future may help to identify significant mediators to improved weight loss outcomes in online social networking groups. 相似文献
997.
Yara Nasser Philippe Fayemendy Manon Arnal Huguette Sourisseau Sandrine Bonhommo Jean-Claude Desport Béatrice Morin Pierre Jésus 《Nutrition Clinique et Métabolisme》2018,32(3):184-186
In institutions and at home, some patients may have difficulty mobilizing and undressing, or refusing to put on their underwear. It is therefore likely that weighing dressed patients is a common practice. The overestimation of the body weight thus obtained could lead to an error in the evaluation of the nutritional status. The aim of the study was to determine the extent to which adult patients dressed versus underwear could alter their nutritional status. Fifty-one patients were included. Dressed weighing overestimated the actual weight of 1.6 ± 0.6 kg and induced an overestimation of nutritional status classification in almost 14% of cases. In addition, the weight of the clothes was different according to the sex and the conditions of outside temperature. These results suggest that it is desirable as much as possible to weigh all adult patients in underwear. 相似文献
998.
Introduction and objective
Gestational weight gain (GWG) has been reported to be associated with pregnancy outcomes. The aim of this study was to evaluate the effects of GWG on maternal and birth complications.Materials and methods
A prospective and longitudinal cohort study was conducted among pregnant women who had attended antenatal centers in Constantine, Algeria, between 2013 and 2015. Two hundred pregnant women aged 19 to 41 years old were followed for 9 months of pregnancy. They underwent body weight measurement during routine examination at first, second and third trimester. GWG was categorized as below, within or above the Institute of Medicine (IOM) (2009) recommendations. Data included age and parity. Pregnancy outcomes were analyzed in relation to GWG.Results
Mean GWG was 8.9 ± 5.4 kg. Among all subjects, only 27.5% of women had gained the recommended amount of weight, with 48.5% gaining less than recommended, and 24.0% gaining more than recommended by the IOM. High birth weight was significantly more frequent in women with excessive weight gain, compared to those with normal gain (27.1% vs 14.5%, P = 0.04). The percentage of low birth infants was statistically very high in pregnant women with excessive weight gain, compared to women with normal gain (14.6% vs 3.6%, P = 0.04). The risk of gestational hypertension increased with excessive GWG (P < 0.01).Conclusion
The pregnancy and birth outcomes depend on the women's gestational weight gain. 相似文献999.
目的 探讨低出生体质量儿坏死性小肠结肠炎(NEC)的影响因素、手术疗效与预后。 方法 以2006年1月至2015年12月收治的146例低出生体质量NEC患儿为病例组,另采用随机数字表法选取同期在新生儿重症监护室(NICU) 住院治疗的146例非NEC低出生体质量儿为对照组。分析两组患儿的临床资料,采用单因素和多因素分析探讨NEC的影响因素,并分析NEC患儿中手术组与保守治疗组疗效的差异。 结果 多因素logistic回归分析显示,母乳喂养与喂服益生菌为NEC的保护性因素,先天性心脏病、败血症与输血是NEC的危险因素。手术组的好转率(95.45%)明显高于保守治疗组(85.00%)(P<0.05)。 结论 低出生体质量儿NEC的发病受多种因素影响,应针对其影响因素进行综合干预。适合的手术疗法能提高疗效,改善患儿的预后。 相似文献
1000.
Hui Chen Yu-Jie Li Xiao-Fei Li Yan-Jun Sun Hong-Wei Li Fang-Yi Su 《Journal of Asian natural products research》2018,20(1):92-100
A new homoisoflavanone, (3R)-5-hydroxy-7-methoxyl-3-(2′-hydroxy-4′- methoxybenzyl)-chroman-4-one (1), together with six known analogs, were isolated from the rhizomes of Polygonatum sibiricum. Their structures were elucidated on the basis of extensive spectroscopic analysis. All compounds were tested for their estrogenic activity using the MCF-7 estrogenresponsive human breast cancer cell lines. At a dose of 0.1 μmol/L, compounds 1–7 exhibited significant proliferative effects on MCF-7 cells compared with E2. The molecular docking study results indicated that the activity of compounds 3, 5, 6, and 7 may be the binding with ERR. 相似文献