全文获取类型
收费全文 | 42383篇 |
免费 | 4282篇 |
国内免费 | 65篇 |
专业分类
耳鼻咽喉 | 372篇 |
儿科学 | 1091篇 |
妇产科学 | 1084篇 |
基础医学 | 5823篇 |
口腔科学 | 995篇 |
临床医学 | 4599篇 |
内科学 | 8584篇 |
皮肤病学 | 488篇 |
神经病学 | 4516篇 |
特种医学 | 1729篇 |
外国民族医学 | 1篇 |
外科学 | 5837篇 |
综合类 | 1018篇 |
一般理论 | 34篇 |
预防医学 | 3955篇 |
眼科学 | 918篇 |
药学 | 2860篇 |
2篇 | |
中国医学 | 43篇 |
肿瘤学 | 2781篇 |
出版年
2021年 | 511篇 |
2020年 | 341篇 |
2019年 | 548篇 |
2018年 | 667篇 |
2017年 | 523篇 |
2016年 | 547篇 |
2015年 | 615篇 |
2014年 | 866篇 |
2013年 | 1525篇 |
2012年 | 1973篇 |
2011年 | 2148篇 |
2010年 | 1111篇 |
2009年 | 1166篇 |
2008年 | 1929篇 |
2007年 | 2040篇 |
2006年 | 2069篇 |
2005年 | 2157篇 |
2004年 | 2063篇 |
2003年 | 1928篇 |
2002年 | 1933篇 |
2001年 | 1152篇 |
2000年 | 1146篇 |
1999年 | 1070篇 |
1998年 | 539篇 |
1997年 | 448篇 |
1996年 | 402篇 |
1995年 | 434篇 |
1994年 | 417篇 |
1993年 | 390篇 |
1992年 | 818篇 |
1991年 | 875篇 |
1990年 | 823篇 |
1989年 | 763篇 |
1988年 | 733篇 |
1987年 | 686篇 |
1986年 | 669篇 |
1985年 | 659篇 |
1984年 | 569篇 |
1983年 | 451篇 |
1982年 | 363篇 |
1981年 | 357篇 |
1980年 | 326篇 |
1979年 | 481篇 |
1978年 | 394篇 |
1977年 | 347篇 |
1976年 | 322篇 |
1975年 | 307篇 |
1974年 | 390篇 |
1973年 | 305篇 |
1972年 | 336篇 |
排序方式: 共有10000条查询结果,搜索用时 29 毫秒
1.
2.
Krishna Pillai Javid Akhter Terence C. Chua Mena Shehata Nayef Alzahrani Issan Al-Alem David L. Morris 《Medicine》2015,94(9)
Thermal ablation of liver tumors near large blood vessels is affected by the cooling effect of blood flow, leading to incomplete ablation. Hence, we conducted a comparative investigation of heat sink effect in monopolar (MP) and bipolar (BP) radiofrequency ablation (RFA), and microwave (MW) ablation devices.With a perfused calf liver, the ablative performances (volume, mass, density, dimensions), with and without heat sink, were measured. Heat sink was present when the ablative tip of the probes were 8.0 mm close to a major hepatic vein and absent when >30 mm away. Temperatures (T1 and T2) on either side of the hepatic vein near the tip of the probes, heating probe temperature (T3), outlet perfusate temperature (T4), and ablation time were monitored.With or without heat sink, BP radiofrequency ablated a larger volume and mass, compared with MP RFA or MW ablation, with latter device producing the highest density of tissue ablated. MW ablation produced an ellipsoidal shape while radiofrequency devices produced spheres.Percentage heat sink effect in Bipolar radiofrequency : Mono-polar radiofrequency : Microwave was (Volume) 33:41:22; (mass) 23:56:34; (density) 9.0:26:18; and (relative elipscity) 5.8:12.9:1.3, indicating that BP and MW devices were less affected.Percentage heat sink effect on time (minutes) to reach maximum temperature (W) = 13.28:9.2:29.8; time at maximum temperature (X) is 87:66:16.66; temperature difference (Y) between the thermal probes (T3) and the temperature (T1 + T2)/2 on either side of the hepatic vessel was 100:87:20; and temperature difference between the (T1 + T2)/2 and temperature of outlet circulating solution (T4), Z was 20.33:30.23:37.5.MW and BP radiofrequencies were less affected by heat sink while MP RFA was the most affected. With a single ablation, BP radiofrequency ablated a larger volume and mass regardless of heat sink. 相似文献
3.
O. Morris M. Fairclough J. Grigg C. Prenant A. McMahon 《Journal of labelled compounds & radiopharmaceuticals》2019,62(1):4-23
Affinity peptide and protein‐ (APP) based radiotracers are an increasingly popular class of radiotracer in positron emission tomography (PET), which was once dominated by the use of small molecule radiotracers. Radiolabelled monoclonal antibodies (mAbs) are important examples of APPs, yet a preference for smaller APPs, which exhibit fast pharmacokinetics and permit rapid PET aided diagnosis, has become apparent. 18F exhibits favourable physical characteristics for APP radiolabelling and has been described as an ideal PET radionuclide. Notwithstanding, 18F radiolabelling of APP is challenging, and this is echoed in the literature where a number of diverse approaches have been adopted. This review seeks to assess and compare the approaches taken to 18F APP radiolabelling with the intention of highlighting trends within this expanding field. Generic themes have emerged in the literature, namely the use of mild radiolabelling conditions, a preference of site‐specific methodologies with an impetus for short, automated procedures which produce high‐yielding [18F]APPs. 相似文献
4.
Julia H. Vermylen Gordon J. Wood Elaine R. Cohen Jeffrey H. Barsuk William C. McGaghie Diane B. Wayne 《Journal of pain and symptom management》2019,57(3):682-687
Introduction
Physician communication impacts patient outcomes. However, communication skills, especially around difficult conversations, remain suboptimal, and there is no clear way to determine the validity of entrustment decisions. The aims of this study were to 1) describe the development of a simulation-based mastery learning (SBML) curriculum for breaking bad news (BBN) conversation skills and 2) set a defensible minimum passing standard (MPS) to ensure uniform skill acquisition among learners.Innovation
An SBML BBN curriculum was developed for fourth-year medical students. An assessment tool was created to evaluate the acquisition of skills involved in a BBN conversation. Pilot testing was completed to confirm improvement in skill acquisition and set the MPS.Outcomes
A BBN assessment tool containing a 15-item checklist and six scaled items was developed. Students' checklist performance improved significantly at post-test compared to baseline (mean 65.33%, SD = 12.09% vs mean 88.67%, SD = 9.45%, P < 0.001). Students were also significantly more likely to have at least a score of 4 (on a five-point scale) for the six scaled questions at post-test. The MPS was set at 80%, requiring a score of 12 items on the checklist and at least 4 of 5 for each scaled item. Using the MPS, 30% of students would require additional training after post-testing.Comments
We developed a SBML curriculum with a comprehensive assessment of BBN skills and a defensible competency standard. Future efforts will expand the mastery model to larger cohorts and assess the impact of rigorous education on patient care outcomes. 相似文献5.
Gordon K. B. Saburov V. O. Koryakin S. N. Gulidov I. A. Fatkhudinov T. Kh. Arutyunyan I. V. Kaprin A. D. Solov’ev A. N. 《Bulletin of experimental biology and medicine》2022,173(2):281-285
Bulletin of Experimental Biology and Medicine - Fast neutron therapy, which previously has demonstrated effective results, but along with a large number of complications, can again be considered a... 相似文献
6.
Phytonutrients extracted from natural resources are receiving much attention among researchers due to their highly antioxidative characteristics which prevent several degenerative diseases including cardiovascular diseases and cancers. These nutraceutical compounds can be used in food, pharmaceutical and cosmetic products as natural antioxidants, preservatives, colourants and functional foods. Huge volume of food wastes are generated from the processing industry and these low-value food residues are rich in various phytonutrients worth recovering. This approach of valorisation reduces the generation of food wastes and is cost-effective considering the cheap feedstock, reduced waste management expenses and high market value of extracted compounds. In light of the health and safety risks posed by commonly used organic extraction solvents derived from the petrochemical industry, there is a need to recover the phytonutrients using green, sustainable and efficient solvents that are safe for human consumption. This work discusses ethyl lactate as a safe, green, efficient and potentially cheap solvent to recover phytonutrients from fruit and vegetable by-products. Ethyl lactate is compared with other organic solvents commonly used from the aspects of safety, environmental impacts and efficiency. Current challenges when employing ethyl lactate are also discussed. 相似文献
7.
Perinatal care providers are likely to encounter adverse events such as intrapartum emergencies, traumatic births, or maternal or fetal deaths. As a result of being directly or indirectly involved in an adverse event, health care providers can be considered second victims. The experience of the second victim phenomenon can lead to significant physical, psychological, and psychosocial sequelae that can negatively impact the provider's personal and professional life for either a short or long duration of time. When health care providers experience an adverse event, they may manifest symptoms of guilt, shame, blame, flashbacks, nightmares, insomnia, isolation, helplessness, and hopelessness, thereby becoming the second victim. Following an adverse event, health care providers who experience second victim phenomenon experience stages of recovery that influence subsequent professional and personal well‐being. Persons who experience the second victim phenomenon can incorporate self‐care behaviors to assist with recovery. Health care organizations have a responsibility to implement efficacious support programs that promote the provider's recovery and a return to safe and full function in the workplace. 相似文献
8.
9.
<正>Photobiomodulation (PBM)-the irradiation of cells or tissues with low-intensity red to near-infrared light-is emerging as an effective means of enhancing cell and tissue resilience and repair. As reviewed elsewhere (Gordon et al., 2019), the intracellular effects of 相似文献
10.