全文获取类型
收费全文 | 12604篇 |
免费 | 855篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 435篇 |
妇产科学 | 267篇 |
基础医学 | 1519篇 |
口腔科学 | 160篇 |
临床医学 | 1357篇 |
内科学 | 2077篇 |
皮肤病学 | 153篇 |
神经病学 | 1640篇 |
特种医学 | 613篇 |
外科学 | 2105篇 |
综合类 | 133篇 |
一般理论 | 22篇 |
预防医学 | 1200篇 |
眼科学 | 157篇 |
药学 | 854篇 |
中国医学 | 25篇 |
肿瘤学 | 679篇 |
出版年
2023年 | 72篇 |
2022年 | 96篇 |
2021年 | 258篇 |
2020年 | 171篇 |
2019年 | 292篇 |
2018年 | 336篇 |
2017年 | 217篇 |
2016年 | 265篇 |
2015年 | 250篇 |
2014年 | 446篇 |
2013年 | 615篇 |
2012年 | 959篇 |
2011年 | 1006篇 |
2010年 | 550篇 |
2009年 | 508篇 |
2008年 | 876篇 |
2007年 | 850篇 |
2006年 | 823篇 |
2005年 | 854篇 |
2004年 | 774篇 |
2003年 | 735篇 |
2002年 | 672篇 |
2001年 | 113篇 |
2000年 | 84篇 |
1999年 | 105篇 |
1998年 | 149篇 |
1997年 | 107篇 |
1996年 | 107篇 |
1995年 | 98篇 |
1994年 | 77篇 |
1993年 | 63篇 |
1992年 | 73篇 |
1991年 | 52篇 |
1990年 | 37篇 |
1989年 | 48篇 |
1988年 | 79篇 |
1987年 | 59篇 |
1986年 | 38篇 |
1985年 | 38篇 |
1984年 | 50篇 |
1983年 | 50篇 |
1982年 | 51篇 |
1981年 | 38篇 |
1980年 | 53篇 |
1979年 | 37篇 |
1978年 | 27篇 |
1977年 | 24篇 |
1976年 | 25篇 |
1972年 | 25篇 |
1971年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Kristy B. Arbogast Akira Nishisaki Sriram Balasubramanian Jon Nysaether Dana Niles Robert M. Sutton Kathryn E. Roberts Lauren Nadkarni John Boulet Matthew R. Maltese Vinay M. Nadkarni 《Resuscitation》2009,80(10):1187-1191
BackgroundHigh-fidelity manikins have been shown to be useful in teaching appropriate cardiopulmonary resuscitation (CPR) techniques. Similarity of manikin chest compression characteristics to real children is desirable. Little data exists on thorax stiffness in infants and children to guide manikin construction.ObjectiveTo determine a ‘consensus clinical-expert assessment’ of the pediatric chest stiffness for two specific age groups—infants and 5-year-olds.MethodsFour manikins in each of two sizes (5-year child, 6-month infant) were identically constructed, except for thorax downstroke spring stiffness. Health care providers with pediatric CPR experience provided chest compressions to each manikin in random order, masked to thoracic stiffness. Each health care provider was instructed to identify the manikin with downstroke thoracic stiffness most similar to children on whom they have performed chest compressions. Duplicate assessment of a randomly selected, previously assessed manikin was performed to assess health care provider consistency using the kappa statistic. Subject inter-rater agreement on which manikin best approximated a child of that age was assessed by calculating the percentage of subjects who identified that manikin as the best approximation of an actual child.ResultsA convenience sample of 63 international experts was obtained: 52 from Critical Care, 3 from Emergency Medicine, 4 from Pediatrics, and 4 from other specialties. There were 6 and 8 experts whose assessments were inconsistent for the infant manikins and child manikins, respectively. Approximately half of the subjects agreed on a single manikin as the best approximation of the human for both the infant (46%) and child manikins (43%). Excluding assessments of stiffness “out of range”, the percentage of experts who agreed on a single manikin as the best approximation for the human increased to approximately 90% for each manikin size.ConclusionExperienced health care providers consistently identified and agreed on the manikin thorax stiffness which they felt best approximated downstroke chest compression stiffness of children and infants. Expert opinion can be used to create manikins with realistic spring stiffness for CPR training. Further study is needed to evaluate whether enhanced manikin biofidelity will improve CPR performance. 相似文献
993.
994.
进食障碍,这种威胁生命的疾病在西方国家很常见,直到最近,进食障碍还被认为在非西方文化地区是罕见的。然而,进食障碍的患病率在很多相对富裕的非西方国家中迅速增长,因为这些地区的民众,特别是年轻的女性,在国际媒体的影响下,把“以瘦为美”这个已经被广泛传播的概念内在化了。这篇综述讨论了非西方地区中影响进食障碍发生的因素,特别关注了城市化、现代化、西方化和女性角色转变的影响。本文还介绍了在西方国家发展起来的、已经被证明可以成功消除“以瘦为美”的负面影响的认知失调纠正项目,并讨论了其在东亚和其它非西方国家中的应用价值。 相似文献
995.
Geórgia Labuto Ana P. Carvalho Ana S. Mestre Mikaela S. dos Santos Helen R. Modesto Tiago Dias Martins Sherlan G. Lemos Heron D.T. da Silva Elma Neide Vasconcelos Martins Carrilho Wagner A. Carvalho 《Sustainable Chemistry and Pharmacy》2022
Pharmaceuticals enter water bodies mainly through urban effluents harmful to the biota, inducing microbial resistance, and impacting hydric security. Activated carbon has been used for effluent treatment and associated with ferromagnetic nanoparticles can facilitate the separation of this adsorbent from an aqueous medium and improve the adsorption capacity. A yeast-based carbon (YC) prepared from the residue of the ethanol industry and a magnetic composite prepared from YC (NP-YC) were used to remove ibuprofen (IBU) and caffeine (CAF) from deionized water and primary sewage effluent (PE). A minimum of 51 and 90 mg/g of IBU and CAF were removed by NP-YC, respectively, whereas YC removed a minimum of 107 and 106 mg/g for such contaminants. The removal of both contaminants was favored for competitive studies using NP-YC as adsorbent (removals >70% for deionized water, and >60% and >75% for IBU and CAF, respectively, for PE). The values of qmax obtained for YC in the competitive assays were about the sum of both qmax for the individual experiments suggesting that each molecule adsorbs in a different site. Successive adsorption cycles using the same mass of adsorbent removed higher amounts of IBU and CAF by exposing the adsorbents to new volumes of a solution containing equal or increasing concentrations of contaminants than those exposed to a single high concentration solution. This behavior is probably due to the driving force effect. It suggests that the reuse of synthesized adsorbents was possible without previous desorption, increasing the usability of the synthesized adsorbents. 相似文献
996.
997.
Jon O Curwen Helen L Musgrove Jane Kendrew Graham H P Richmond Donald J Ogilvie Stephen R Wedge 《Clinical cancer research》2008,14(10):3124-3131
PURPOSE: Inhibition of vascular endothelial growth factor-A (VEGF) signaling is a key therapeutic approach in oncology given the role of VEGF in angiogenesis and vascular permeability in solid tumors. Clinical trials examining VEGF signaling inhibitors commonly report hypertension. We examined the effect of cediranib, a highly potent VEGF signaling inhibitor, on the blood pressure of rats and the ability of standard antihypertensive agents to modulate the consequences of VEGF signaling inhibition. EXPERIMENTAL DESIGN: The ability of cediranib to induce hypertensive changes and the effect of giving antihypertensive therapy were investigated in conscious, unrestrained telemetered rats. Two antihypertensive agents were studied: captopril, an angiotensin-converting enzyme inhibitor, and nifedipine, a dihydropyridine calcium channel blocker. The antitumor activity of cediranib, alone and in combination with nifedipine, was also evaluated in a LoVo human colorectal tumor xenograft model in nude rats. All treatments were given orally. RESULTS: Administration of 0.1 to 1.5 mg/kg/d of cediranib for 4 consecutive days induced a relatively mild hypertensive effect, elevating diastolic blood pressure by 10 to 14 mmHg. Dosing 3 mg/kg/d cediranib for 4 days induced a marked hypertension of 35 to 50 mmHg. Captopril (30 mg/kg, qd) was effective at lowering a 10 mmHg increase in blood pressure but not a 35 to 50 mmHg increase. However, the latter was rapidly reversed by administration of nifedipine (10 mg/kg, bd). Coadministration of nifedipine did not negatively affect the antitumor activity of cediranib (1.5 mg/kg/d). CONCLUSIONS: Hypertension is a direct consequence of inhibiting VEGF signaling but can be controlled with appropriately selected, standard antihypertensive medication. 相似文献
998.
999.