全文获取类型
收费全文 | 53586篇 |
免费 | 3793篇 |
国内免费 | 265篇 |
专业分类
耳鼻咽喉 | 519篇 |
儿科学 | 1937篇 |
妇产科学 | 1421篇 |
基础医学 | 8045篇 |
口腔科学 | 798篇 |
临床医学 | 5149篇 |
内科学 | 12060篇 |
皮肤病学 | 1176篇 |
神经病学 | 5900篇 |
特种医学 | 1126篇 |
外科学 | 4446篇 |
综合类 | 340篇 |
现状与发展 | 1篇 |
一般理论 | 43篇 |
预防医学 | 5000篇 |
眼科学 | 869篇 |
药学 | 4076篇 |
中国医学 | 142篇 |
肿瘤学 | 4596篇 |
出版年
2024年 | 67篇 |
2023年 | 619篇 |
2022年 | 1122篇 |
2021年 | 2431篇 |
2020年 | 1402篇 |
2019年 | 1795篇 |
2018年 | 1976篇 |
2017年 | 1598篇 |
2016年 | 1755篇 |
2015年 | 1911篇 |
2014年 | 2506篇 |
2013年 | 3131篇 |
2012年 | 4589篇 |
2011年 | 4599篇 |
2010年 | 2429篇 |
2009年 | 2081篇 |
2008年 | 3473篇 |
2007年 | 3489篇 |
2006年 | 3146篇 |
2005年 | 2847篇 |
2004年 | 2635篇 |
2003年 | 2340篇 |
2002年 | 2120篇 |
2001年 | 249篇 |
2000年 | 197篇 |
1999年 | 267篇 |
1998年 | 342篇 |
1997年 | 288篇 |
1996年 | 197篇 |
1995年 | 185篇 |
1994年 | 182篇 |
1993年 | 142篇 |
1992年 | 102篇 |
1991年 | 89篇 |
1990年 | 68篇 |
1989年 | 79篇 |
1988年 | 74篇 |
1987年 | 72篇 |
1986年 | 66篇 |
1985年 | 65篇 |
1984年 | 85篇 |
1983年 | 70篇 |
1982年 | 80篇 |
1981年 | 66篇 |
1980年 | 63篇 |
1979年 | 34篇 |
1978年 | 35篇 |
1977年 | 38篇 |
1974年 | 31篇 |
1973年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Anna M. de Haan Albert E. Boon Robert R. J. M. Vermeiren Machteld Hoeve Joop T. V. M. de Jong 《Child & youth care forum》2015,44(1):1-16
Background
Dropout from child and adolescent psychotherapy is a common phenomenon which can have negative consequences for the individual later in life. It is therefore important to gain insight on dropout risk factors.Objective
Several potential risk factors [ethnic minority status, a lower socioeconomic status (SES), and higher problem severity] were analyzed in present study. Innovations are that these risk factors were examined for children and adolescents separately, and a distinction was made in termination status between referred patients, dropouts and completers.Methods
For ethnic majority and minority outpatient children (age 5–11, n = 399) and adolescents (age 12–20, n = 352) problem severity, ethnic background, SES, and treatment termination status (completer, dropout, referral) were specified. Multinomial logistic regression models were used as main method of analysis.Results
For children, a Moroccan/Turkish ethnicity and higher externalizing scores were risk factors for being referred. For adolescents, a Surinamese/Antillean ethnicity, being female, being older, and lower parental SES occupation levels were risk factors for dropout.Conclusions
Different dropout risk profiles emerged for children versus adolescents, and for dropouts versus referrals. Also, it depended on the specific ethnic background whether ethnic minority status was a predictor for dropout, and the relationship between SES and termination status differed by whether parental SES occupation or parental SES education were used as SES indicator. Professionals should thus be aware of these potential risk factors for dropout or referral when treating children and adolescents.992.
The perceived impact of public involvement in palliative care in a provincial palliative care network in the Netherlands: a qualitative study 下载免费PDF全文
993.
994.
Great ‘app‐eal’ but not there yet: A review of iPhone nutrition applications relevant to child weight management 下载免费PDF全文
995.
996.
Justyna Kalinowska-Tucik Jakub Staro Anna Krawczuk Stefan Mordalski Dawid Warszycki Grzegorz Sataa Adam S. Hogendorf Andrzej J. Bojarski 《RSC advances》2018,8(33):18672
The development of compounds with enhanced activity and selectivity by a conserved spatial orientation of the pharmacophore elements has a long history in medicinal chemistry. Rigidified compounds are an example of this concept. However, the intramolecular interactions were seldom used as a basis for conformational restraints. Here, we show the weak intramolecular interactions that contribute to the relatively well-conserved geometry of N1-arylsulfonyl indole derivatives. The structure analysis along with quantum mechanics calculations revealed a crucial impact of the sulfonyl group on the compound geometry. The weak intramolecular C–H⋯O interaction stabilizes the mutual "facing" orientation of two aromatic fragments. These findings extend the pharmacological interpretation of the sulfonyl group role from the double hydrogen bond acceptor to the conformational scaffold based on intramolecular forces. This feature has, to date, been omitted in in silico drug discovery. Our results should increase the awareness of researchers to consider the conformational preference when designing new compounds or improving computational methods.The impact of weak intramolecular C–H⋯O interactions on the conformational stability of bis-arylsulfones is discussed, suggesting different role of sulfonyl group in the ligand – 5HT6 receptor interaction. 相似文献
997.
Do patients’ information requirements for choice in health care vary with their socio‐demographic characteristics? 下载免费PDF全文
Anthony A. Laverty MSc Anna Dixon PhD Christopher Millett PhD 《Health expectations》2015,18(5):1127-1138
Objectives
This study examines whether the information used to inform hospital choice, and the sources of that information, varies with patients’ socio‐demographic characteristics. It also examines whether information used by patients to inform choice is associated with attending their local hospital.Methods
A survey of 1033 patients who were offered a choice of hospital provider for elective treatment in England. Logistic regression was used to examine associations between patient characteristics and information used to inform choice of a hospital provider and sources of information used.Results
Factors most important to patients in choosing a hospital were quality of care, cleanliness, standard of facilities and reputation. While quality of care and related factors are important to the majority of patients, those with lower levels of education were more likely to report that location and appointment times were important. Those who thought quality important were more likely to attend their local hospital provider. The main sources of information used to inform choice of hospital were own experience, family and friends and the general practitioner (GP). Patients who sought advice from their GP or booking advisors were less likely to attend their local hospitals.Conclusions
Differences among patients as to what factors are important when choosing a hospital provider and what information and support they access suggest there needs to be a variety of information sources and support available to promote choice. Greater shared decision making through active involvement and support by GPs or booking advisors may be required if they are to make choices in line with their preferences. 相似文献998.
Nalini Ranjit Anna V Wilkinson Leslie M Lytle Alexandra E Evans Debra Saxton Deanna M Hoelscher 《The international journal of behavioral nutrition and physical activity》2015,12(Z1):S4
Background
It is well documented in the literature that low socioeconomic status (SES) is associated with lower consumption of healthy foods and that these differences in consumption patterns are influenced by neighborhood food environments. Less understood is the role that SES differences in physical and social aspects of the home food environment play in consumption patterns.Methods
Using data on 4th grade children from the 2009–2011 Texas School Physical Activity and Nutrition (SPAN) study, we used mixed-effects regression models to test the magnitude of differences in the SPAN Health Eating Index (SHEI) by parental education as an indicator of SES, and the extent to which adjusting for measures of the home food environment, and measures of the neighborhood environment accounted for these SES differences.Results
Small but significant differences in children’s SHEI by SES strata exist (-1.33 between highest and lowest SES categories, p<0.01). However, incorporating home food environment and neighborhood environment measures in this model eliminates these differences (-0.7, p=0.145). Home food environment explains a greater portion of the difference. Both social (mealtime structure) and physical aspects (food availability) of the home food environment are strongly associated with consumption of healthy and unhealthy foods.Conclusions
Our findings suggest that modifiable parent behaviors at home can improve children’s eating habits and that the neighborhood may impact diet in ways other than through access to healthy food.999.
1000.
Subat Turdi Anna F. Huff Jiaojiao Pang Emily Y. He Xiyao Chen Shuyi Wang Yuguo Chen Yingmei Zhang Jun Ren 《Toxicology letters》2015
Menopause increases the risk of cardiometabolic diseases in women. This circumstance is usually attributed to a deficiency in circulating estrogen levels although the underlying mechanism remains elusive. Given the pivotal role of AMP-activated protein kinase (AMPK) in the regulation of energy metabolism and cardiac function, this study was designed to examine the role of AMPK in estrogen deficiency and replacement-exerted cardiomyocyte responses. Adult female WT and AMPK kinase dead (KD) mice were subjected to bilateral ovariectomy (OVX) or sham operation. A cohort of ovariectomized mice received 17β-estradiol (E2) (40 μg/kg/day, i.p.) for 6 weeks. Mechanical and intracellular Ca2+ properties were evaluated including peak shortening (PS), time-to-PS (TPS), time-to-90%-relengthening (TR90), and maximal velocity of shortening/relengthening (±dL/dt). Levels of AMPK, Akt JNK, ACC, SERCA, membrane Glut4, AS160 and PGC-1α were assessed using Western blot. OVX significantly decreased PS, ±dL/dt and intracellular Ca2+ rise in responsible to electric stimulus, prolonged TR90 and intracellular Ca2+ decay without affecting TPS and resting intracellular Ca2+, the effects of which were reconciled by E2 replacement. Western blot analysis depicted that OVX suppressed phosphorylation of Akt AMPK and ACC although it promoted JNK phosphorylation, the effects of which were mitigated or significantly attenuated by E2 treatment in WT but not KD mice. Moreover, OVX procedure downregulated SERCA2a and membrane Glut4 while inhibiting AS160 phosphorylation without affecting PGC-1α levels. In vitro study revealed that E2 corrected cardiomyocyte contractile dysfunction elicited by OVX in cardiomyocytes from WT but not the AMPK kinase dead mice. Taken together, these data suggest that E2 treatment ameliorates estrogen deficiency-induced changes in cardiac contractile function possibly through an AMPK-dependent mechanism. 相似文献