全文获取类型
收费全文 | 10495篇 |
免费 | 630篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 363篇 |
妇产科学 | 269篇 |
基础医学 | 1229篇 |
口腔科学 | 76篇 |
临床医学 | 1762篇 |
内科学 | 1806篇 |
皮肤病学 | 106篇 |
神经病学 | 1106篇 |
特种医学 | 212篇 |
外科学 | 833篇 |
综合类 | 108篇 |
一般理论 | 126篇 |
预防医学 | 1506篇 |
眼科学 | 155篇 |
药学 | 753篇 |
中国医学 | 7篇 |
肿瘤学 | 671篇 |
出版年
2023年 | 42篇 |
2022年 | 95篇 |
2021年 | 198篇 |
2020年 | 103篇 |
2019年 | 202篇 |
2018年 | 208篇 |
2017年 | 177篇 |
2016年 | 190篇 |
2015年 | 230篇 |
2014年 | 334篇 |
2013年 | 524篇 |
2012年 | 729篇 |
2011年 | 760篇 |
2010年 | 418篇 |
2009年 | 389篇 |
2008年 | 699篇 |
2007年 | 660篇 |
2006年 | 686篇 |
2005年 | 682篇 |
2004年 | 670篇 |
2003年 | 646篇 |
2002年 | 550篇 |
2001年 | 116篇 |
2000年 | 111篇 |
1999年 | 136篇 |
1998年 | 119篇 |
1997年 | 91篇 |
1996年 | 102篇 |
1995年 | 97篇 |
1994年 | 67篇 |
1993年 | 71篇 |
1992年 | 78篇 |
1991年 | 85篇 |
1990年 | 72篇 |
1989年 | 84篇 |
1988年 | 76篇 |
1987年 | 56篇 |
1986年 | 61篇 |
1985年 | 72篇 |
1984年 | 49篇 |
1983年 | 35篇 |
1982年 | 49篇 |
1981年 | 38篇 |
1980年 | 37篇 |
1979年 | 30篇 |
1978年 | 27篇 |
1977年 | 26篇 |
1976年 | 23篇 |
1975年 | 23篇 |
1974年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Yifat Cohen Anthony Spirito Cheryl Sterling Deidre Donaldson Ronald Seifer Barry Plummer Ruscinda Avila Kathy Ferrer 《Journal of child psychology and psychiatry, and allied disciplines》1996,37(8):989-993
Adolescents who were psychiatrically hospitalized ( N = 105) were classified as sexually abused, physically abused, both sexually and physically abused, or not abused, and studied to determine the prevalence of suicidal behavior and psychiatric disorders. Self-reports of hopelessness, depression, coping, and self-concept were also examined. No difference in suicidal behavior or psychiatric disorder, based on abuse history, was found, with one exception. Adolescents who were sexually abused, particularly those who experienced the most severe sexual abuse, used negative coping strategies more often than those not sexually abused. Findings suggest that symptomatology of adolescents who are psychiatrically hospitalized does not differ markedly based on history of abuse. 相似文献
52.
Cheryl A. Cameron PhD JD C. Scott Litch JD MA Martha Liggett JD MS Steven Heimberg MD JD 《Special care in dentistry》1995,15(5):192-200
This paper examines medical malpractice law as it applies to medically necessary oral health care. The basic legal concepts and reported cases involving medically necessary oral health care are reviewed. It is concluded that dental professionals and consumer advocates must advance their educational and legislative advocacy efforts so that health professional colleagues and the public will become aware of the importance of these services and insurers will routinely include coverage of medically necessary oral health care in their medical and dental policies. While failure to provide medically necessary oral health care can be violative of patient rights and legally actionable, medical malpractice litigation should always be the behavior modifier of last resort. 相似文献
53.
Rosenberg Leonard S. Hostetler Cheryl K. Wagenknecht Dietmar M. Aunet Diane A. 《Pharmaceutical research》1988,5(8):514-517
Esmolol hydrochloride degrades in aqueous solutions by the hydrolysis of a labile aliphatic carboxy-ester group. The products are methanol and ASL-8123. The resulting aliphatic carboxylic acid moiety (ASL-8123) has a pK of 4.80, which is within 1 pH unit of the pH of the formulation. ASL-8123 therefore acts as a secondary buffer and minimizes the change in pH due to degradation. Equations are presented to calculate the change in the pH when the primary degradation product acts as a secondary buffer. This information can be used in the development of a parenteral product to predict, a priori, the concentration of buffer necessary for optimal pH maintenance. This knowledge can reduce the number of formulation screens required to determine the necessary buffer capacity for optimal drug stability. 相似文献
54.
MIM/BEG4, a Sonic hedgehog-responsive gene that potentiates Gli-dependent transcription 总被引:7,自引:0,他引:7
Callahan CA Ofstad T Horng L Wang JK Zhen HH Coulombe PA Oro AE 《Genes & development》2004,18(22):2724-2729
55.
Rats with lesions of the area postrema (APX) are known to exhibit an enhanced intake of highly palatable foods such as sweetened condensed milk and cookies. These observations suggest the possibility that APX rats find these foods more rewarding and will work harder to obtain these foods. Sham and APX rats were tested on fixed ratio (FR) and progressive ratio (PR) schedules. APX rats consistently pressed more times to receive sucrose solution and attained both FR 3 and FR 5 criteria significantly faster than sham-lesioned control rats. Furthermore, rats with APX had significantly higher break points than sham-lesioned control rats on a progressive ratio schedule. These results support the hypothesis that rats with lesions of the area postrema will consistently work harder to obtain a highly palatable food reward. 相似文献
56.
Cannabinoids have been shown to influence food intake, and until recently, the neural pathways mediating these effects have remained obscure. It has been previously shown that intracerebroventricular injection of delta-9-tetrahydrocannabinol (Δ9-THC) causes increased consumption of palatable foods in rats, and we postulated the involvement of the hindbrain in this cannabinoid-induced food intake. Cannulated rats (both female and male groups) trained to consume sweetened condensed milk received either lateral or fourth ventricle injections of CP 55,940 and were presented with sweetened condensed milk 15 min after injection. Rats were injected over a range of doses between 100 pg and 10 μg per rat. Milk intake was recorded for a total of 3 h. Lateral ventricle injection of CP 55,940 increased milk intake at doses in the microgram range. However, CP 55,940 was effective in increasing food intake at nanogram doses when injected into the fourth ventricle. Finally, male rats appeared to be more sensitive to CP 55,940 than female rats inasmuch as milk consumption was increased at the 1 ng dose in male rats, whereas only the 10 ng dose was effective in females. These results indicate that CP 55,940 may act in the hindbrain to influence feeding behavior in rats. 相似文献
57.
Siddharth K. Prakash Soniely Lugo‐Ruiz Michelle Rivera‐Dávila Nunilo Rubio Jr. Avni N. Shah Rebecca C. Knickmeyer Cindy Scurlock Melissa Crenshaw Shanlee M. Davis Gary A. Lorigan Aaron T. Dorfman Karen Rubin Cheryl Maslen Vaneeta Bamba Paul Kruszka Michael Silberbach Scientific Advisory Board of the TSRR 《American journal of medical genetics. Part C, Seminars in medical genetics》2019,181(1):7-12
To address knowledge gaps about Turner syndrome (TS) associated disease mechanisms, the Turner Syndrome Society of the United States created the Turner Syndrome Research Registry (TSRR), a patient‐powered registry for girls and women with TS. More than 600 participants, parents or guardians completed a 33‐item foundational survey that included questions about demographics, medical conditions, psychological conditions, sexuality, hormonal therapy, patient and provider knowledge about TS, and patient satisfaction. The TSRR platform is engineered to allow individuals living with rare conditions and investigators to work side‐by‐side. The purpose of this article is to introduce the concept, architecture, and currently available content of the TSRR, in anticipation of inviting proposals to utilize registry resources. 相似文献
58.
Hollie A. Power Jonathan A. Norton Cheryl L. Porter Zoe Doyle Isaiah Hui K. Ming Chan 《The Journal of physiology》2006,577(3):795-803
Intermuscular coherence analysis can be used to assess the common drive to muscles. Coherence in the β-frequency band (15–35 Hz) is thought to arise from common cortical sources. Intermuscular coherence analysis is a potentially attractive tool for the investigation of motor cortical excitability changes because it is non-invasive and can be done relatively quickly. We carried out this study to test the hypothesis that intermuscular coherence analysis was able to detect cortical excitability changes in healthy subjects following transcranial direct current stimulation (tDCS). tDCS has been shown to increase (anodal stimulation) or decrease (cathodal stimulation) the size of the muscle potential evoked by TMS. We found that anodal tDCS caused an increase in motor evoked potential (MEP) size that was paralleled by an increase in β-band intermuscular coherence. Similarly, the reduction in MEP size produced by cathodal tDCS was paralleled by a reduction in β-band intermuscular coherence, while sham stimulation did not result in any change in either MEP amplitude or β-band intermuscular coherence. The similar pattern of change observed for MEP and intermuscular coherence may indicate similar mechanisms of action, although this cannot be assumed without further investigation. These changes do suggest that at least some of the action of tDCS is on cortical networks, and that combined tDCS and intermuscular coherence analysis may be useful in the diagnosis of pathologies affecting motor cortical excitability. 相似文献
59.
Chun Chang John Lipian Dennis A. Barnes Larry Seger Cheryl Burns Brian Bennett Laura Bonney Larry F. Rhodes George M. Benedikt Robert Lattimer Shyhchang S. Huang Victor W. Day 《Macromolecular chemistry and physics.》2005,206(19):1988-2000
Summary: Homopolymers of a bis‐trifluorocarbinol substituted norbornene ( 1 ) (α,α‐bis(trifluoromethyl)bicyclo[2.2.1]hept‐5‐ene‐2‐ethanol or HFANB) and copolymers of 1 with t‐butyl ester of 5‐carboxylic acid ( 2 , t‐BuEsNB) were produced using palladium catalysts and olefinic chain transfer agents such as 1‐hexene and ethylene to control molecular weight. However, these low‐molecular‐weight polymers exhibited relatively low optical transparencies at 193 nm. In fact, the opacity (measured as optical densities in absorbance units per micron) of thin films of these homo‐ and co‐polymers was inversely proportional to their molecular weight. This relationship is consistent with an end group contribution to the film opacity. Spectroscopic analysis of these polymers by 1H NMR and MALDI‐TOF MS confirmed that 1‐hexene and ethylene chain transfer agents generated olefin‐terminated vinyl addition polymers. The olefinic end group contribution to optical density can be eliminated by appropriate chemical modification. Both epoxidation and hydrogenation of the polymer olefinic end groups generated very low optical density materials, independent of molecular weight, that are suitable as 193‐nm photoresist binder resins.
60.
Jennifer A. Ruskey Lior Greenbaum Léanne Roncière Armaghan Alam Dan Spiegelman Christopher Liong Oren A. Levy Cheryl Waters Stanley Fahn Karen S. Marder Wendy Chung Gilad Yahalom Simon Israeli-Korn Vered Livneh Tsvia Fay-Karmon Roy N. Alcalay Sharon Hassin-Baer Ziv Gan-Or 《European journal of medical genetics》2019,62(1):65-69