全文获取类型
收费全文 | 5461篇 |
免费 | 640篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 150篇 |
儿科学 | 178篇 |
妇产科学 | 100篇 |
基础医学 | 709篇 |
口腔科学 | 80篇 |
临床医学 | 561篇 |
内科学 | 1095篇 |
皮肤病学 | 126篇 |
神经病学 | 581篇 |
特种医学 | 197篇 |
外科学 | 939篇 |
综合类 | 145篇 |
预防医学 | 318篇 |
眼科学 | 72篇 |
药学 | 383篇 |
中国医学 | 23篇 |
肿瘤学 | 474篇 |
出版年
2023年 | 23篇 |
2022年 | 53篇 |
2021年 | 141篇 |
2020年 | 106篇 |
2019年 | 194篇 |
2018年 | 201篇 |
2017年 | 170篇 |
2016年 | 169篇 |
2015年 | 208篇 |
2014年 | 218篇 |
2013年 | 293篇 |
2012年 | 307篇 |
2011年 | 341篇 |
2010年 | 277篇 |
2009年 | 211篇 |
2008年 | 266篇 |
2007年 | 299篇 |
2006年 | 275篇 |
2005年 | 268篇 |
2004年 | 231篇 |
2003年 | 246篇 |
2002年 | 205篇 |
2001年 | 182篇 |
2000年 | 144篇 |
1999年 | 135篇 |
1998年 | 76篇 |
1997年 | 53篇 |
1996年 | 45篇 |
1995年 | 41篇 |
1994年 | 30篇 |
1993年 | 20篇 |
1992年 | 82篇 |
1991年 | 65篇 |
1990年 | 50篇 |
1989年 | 62篇 |
1988年 | 46篇 |
1987年 | 46篇 |
1986年 | 45篇 |
1985年 | 33篇 |
1984年 | 31篇 |
1983年 | 24篇 |
1982年 | 16篇 |
1981年 | 18篇 |
1980年 | 20篇 |
1979年 | 19篇 |
1978年 | 17篇 |
1977年 | 17篇 |
1974年 | 8篇 |
1973年 | 10篇 |
1972年 | 9篇 |
排序方式: 共有6131条查询结果,搜索用时 140 毫秒
1.
Angela J. Jacques-Tiura Deborah A. Ellis April Idalski Carcone Sylvie Naar Kathryn Brogan Hartlieb Elizabeth K. Towner Thomas N. Templin K.-L. Catherine Jen 《The Journal of adolescent health》2019,64(3):355-361
Objective
Successful weight loss interventions for African-Americans adolescents are lacking. Cognitive-behavioral interventions seek to develop weight loss skills (e.g., counting calories, goal setting, managing one's environment). Little is known about how well adolescents implement such skills in their daily lives. Study aims were to (1) examine weight loss skills utilization at midpoint and end of a 6-month cognitive-behavioral/motivational interviewing weight loss sequential multiple assignment randomized trial (SMART), and (2) determine if greater skill utilization predicted weight loss at treatment end and 3 months post-treatment.Method
One hundred and eighty six African-Americans adolescents with obesity and their caregiver were first randomly assigned to complete 3 months of cognitive-behavioral and motivational interviewing family-based weight loss treatment in their home or in the research office (Phase 1). Nonresponders (i.e., those who lost < 3% of initial weight, n?=?161) were rerandomized to 3 months of continued skills training (n?=?83) or contingency management (n?=?78) for Phase 2; responders were allocated to 3 months of relapse prevention (n?=?20). Adolescents’ frequency of weight loss skills utilization was assessed via questionnaire at treatment midpoint and end.Results
Higher treatment attendance was associated with better skill utilization. Higher skill utilization was associated with more weight loss at treatment end, whereas higher baseline confidence was associated with more weight loss at follow-up.Conclusions
This study indicates the importance of attending weight loss intervention sessions to develop and strengthen weight loss skills in African-American adolescents with obesity, and strengthening confidence to use such skills for continued weight loss. 相似文献2.
3.
Micro‐evolution of the hepatitis B virus genome in hepatitis B e‐antigen‐positive carriers: Comparison of genotypes B and C at various immune stages
下载免费PDF全文
![点击此处可从《Journal of gastroenterology and hepatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
4.
5.
6.
Kit Galvin Jen Krenz Marcy Harrington Pablo Palmández Richard A. Fenske 《Journal of agromedicine》2016,21(1):113-122
Development of the Practical Solutions for Pesticide Safety guide used participatory research strategies to identify and evaluate solutions that reduce pesticide exposures for workers and their families and to disseminate these solutions. Project principles were (1) workplace chemicals belong in the workplace, and (2) pesticide handlers and farm managers are experts, with direct knowledge of production practices. The project’s participatory methods were grounded in self-determination theory. Practical solutions were identified and evaluated based on five criteria: practicality, adaptability, health and safety, novelty, and regulatory compliance. Research activities that had more personal contact provided better outcomes. The Expert Working Group, composed of farm managers and pesticide handlers, was key to the identification of solutions, as were farm site visits. Audience participation, hands-on testing, and orchard field trials were particularly effective in the evaluation of potential solutions. Small work groups in a Regional Advisory Committee provided the best direction and guidance for a “user-friendly” translational document that provided evidence-based practical solutions. The “farmer to farmer” format of the guide was endorsed by both the Expert Working Group and the Regional Advisory Committee. Managers and pesticide handlers wanted to share their solutions in order to “help others stay safe,” and they appreciated attribution in the guide. The guide is now being used in educational programs across the region. The fundamental concept that farmers and farmworkers are innovators and experts in agricultural production was affirmed by this study. The success of this process demonstrates the value of participatory industrial hygiene in agriculture. 相似文献
7.
Jen auo Hirschberg 《Early child development and care》1990,65(1):57-69
During a period of twenty years [1969-1988] the author has observed 614 cases of congenital malformations and noninflammatory diseases of the larynx in infants and young children, Budapest. He summarizes the most characteristic symptoms of laryngeal pathology in infants, and discusses the diagnostic possibilities. Among the latter, spectrographic analyses complemented by auditory evaluation of pathological cry and different breathing noises play an important role. Based on his investigation author differentiates 20 kinds of pathological crying sounds and 4 basic forms of stridor. He describes the acoustic attributes of different pathological sound phenomena and summarizes characteristic voice changes. 相似文献
8.
The clinical and ultrasonographic (US) features of 15 cases of mesenteric or omental cyst are herein described. This series included seven male and eight female patients, whose age ranged from 2–89 years. Correct clinical diagnosis was made in two children only, but preoperative US examination accurately demonstrated the lesion in 11 of 13 patients (85%). These cystic lesions usually had a thin wall, internal septations, and fluid content with sedimentation. Enteric duplication cysts had a relatively thick wall merging with the muscle layer of bowel loop, and multiloculation was noted mainly with cystic lymphangiomas or pseudocysts. The diagnostic and surgical management of these lesions are briefly reviewed and their US appearance is illustrated. 相似文献
9.
Lipoprotein(a) as a strong indicator for cerebrovascular disease 总被引:19,自引:0,他引:19
G Zenker P K?ltringer G Boné K Niederkorn K Pfeiffer G Jürgens 《Stroke; a journal of cerebral circulation》1986,17(5):942-945
To evaluate the role of lipoprotein(a) (Lp(a] in patients with cerebrovascular disease (CVD), lipid parameters were compared with a control group (CO). Additionally, the Lp(a) serum levels were investigated in a coronary artery disease (CAD) group. The CO was made up of 37 healthy persons (age: 54.5 +/- 7.7, 26 males and 11 females), the CVD group included 46 patients with sustained transient ischemic attack (TIA) prolonged reversible ischemic neurologic deficits (PRIND) and cerebral infarction (CI) (age: 53.6 +/- 9.7, 32 males and 14 females), and the CAD group was made up of 28 survivors of myocardial infarctions (age: 52.5 +/- 8.1, 18 males and 10 females). The median values of Lp(a) in CVD were significantly higher than in the CO (p less than 0.01) and did not differ significantly from the CAD. Total TC, HDL-C, TG, LDL-C and the ratio of LDL-C/HDL-C did not show any significant difference between the control and cerebrovascular disease group. For quantification of the vascular lesions of the carotid system, a Duplex Doppler score system was used. The score correlated with Lp(a) in patients between 40 to 65 years of age (r = 0.34, p less than 0.01). Thus, we conclude that Lp(a) is not only a risk factor for CAD but also for CVD. 相似文献
10.
Intraocular kainic acid injection in Long-Evans rats induces loss of retinal afferents to subcortical visual centers as assessed by the axoplasmic transport of [14C]valine. The optical terminal fields of the pretectal nucleus of the optic tract (NOT), superior colliculus and accessory optic system (AOS) nuclei appear particularly affected. Since NOT and the AOS dorsal terminal nucleus (DTN) represent the first relay station of the visuomotor pathway mediating horizontal optokinetic nystagmus (HOKR), we have studied the characteristics of HOKR after various degrees of retinal deafferentation of these nuclei induced by intraocular KA injection. Taking advantage of the arrangement of the primary optic projections to NOT-DTN, that in rats are almost entirely crossed, in each animal, monocular HOKR induced by stimulation of the injected eye was compared to monocular HOKR elicited by stimulation of the intact, ipsilateral eye. Following NOT-DTN optic denervation, HOKR gain always worsened, and in a way, that the greater the deficits of retinal afferents, the greater the HOKR inability to compensate for visual motion. Furthermore, for any given retinal denervation the higher the stimulus velocity, the greater the HOKR deficit. While the correlation between HOKR gain and the amount of retinal afferents to NOT-DTN would seem to indicate a functional homogeneity of the retinal ganglion cells sending axons to these nuclei, the finding that the extent of HOKR impairment also varied with velocity might not support the above view. 相似文献