全文获取类型
收费全文 | 3409篇 |
免费 | 220篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 133篇 |
妇产科学 | 54篇 |
基础医学 | 407篇 |
口腔科学 | 53篇 |
临床医学 | 389篇 |
内科学 | 640篇 |
皮肤病学 | 65篇 |
神经病学 | 146篇 |
特种医学 | 333篇 |
外科学 | 458篇 |
综合类 | 210篇 |
一般理论 | 2篇 |
预防医学 | 233篇 |
眼科学 | 27篇 |
药学 | 213篇 |
2篇 | |
中国医学 | 35篇 |
肿瘤学 | 256篇 |
出版年
2022年 | 53篇 |
2021年 | 56篇 |
2020年 | 46篇 |
2019年 | 33篇 |
2018年 | 66篇 |
2017年 | 52篇 |
2016年 | 56篇 |
2015年 | 76篇 |
2014年 | 108篇 |
2013年 | 135篇 |
2012年 | 192篇 |
2011年 | 182篇 |
2010年 | 145篇 |
2009年 | 172篇 |
2008年 | 142篇 |
2007年 | 159篇 |
2006年 | 139篇 |
2005年 | 116篇 |
2004年 | 103篇 |
2003年 | 100篇 |
2002年 | 88篇 |
2001年 | 65篇 |
2000年 | 72篇 |
1999年 | 61篇 |
1998年 | 97篇 |
1997年 | 85篇 |
1996年 | 77篇 |
1995年 | 71篇 |
1994年 | 54篇 |
1993年 | 56篇 |
1992年 | 26篇 |
1991年 | 33篇 |
1990年 | 28篇 |
1989年 | 45篇 |
1988年 | 51篇 |
1987年 | 45篇 |
1986年 | 36篇 |
1985年 | 42篇 |
1984年 | 30篇 |
1983年 | 34篇 |
1982年 | 22篇 |
1980年 | 19篇 |
1976年 | 18篇 |
1963年 | 18篇 |
1959年 | 22篇 |
1958年 | 29篇 |
1957年 | 19篇 |
1956年 | 30篇 |
1955年 | 42篇 |
1954年 | 36篇 |
排序方式: 共有3677条查询结果,搜索用时 15 毫秒
2.
Talita da Silva Mendes de Farias Ariclécio Cunha de Oliveira Sandra Andreotti Fernanda Gaspar do Amaral Patrícia Chimin André Ricardo Alves de Proença Francisco Leonardo Torres Leal Rogério Antonio Laurato Sertié Amanda Baron Campana Andressa Bolsoni Lopes Arnaldo Henrique de Souza José Cipolla‐Neto Fabio Bessa Lima 《Journal of pineal research》2015,58(3):251-261
Melatonin, the main hormone produced by the pineal gland, is secreted in a circadian manner (24‐hr period), and its oscillation influences several circadian biological rhythms, such as the regulation of clock genes expression (chronobiotic effect) and the modulation of several endocrine functions in peripheral tissues. Assuming that the circadian synchronization of clock genes can play a role in the regulation of energy metabolism and it is influenced by melatonin, our study was designed to assess possible alterations as a consequence of melatonin absence on the circadian expression of clock genes in the epididymal adipose tissue of male Wistar rats and the possible metabolic repercussions to this tissue. Our data show that pinealectomy indeed has impacts on molecular events: it abolishes the daily pattern of the expression of Clock, Per2, and Cry1 clock genes and Pparγ expression, significantly increases the amplitude of daily expression of Rev‐erbα, and affects the pattern of and impairs adipokine production, leading to a decrease in leptin levels. However, regarding some metabolic aspects of adipocyte functions, such as its ability to synthesize triacylglycerols from glucose along 24 hr, was not compromised by pinealectomy, although the daily profile of the lipogenic enzymes expression (ATP‐citrate lyase, malic enzyme, fatty acid synthase, and glucose‐6‐phosphate dehydrogenase) was abolished in pinealectomized animals. 相似文献
3.
Dr. Arni Raghavendrarao Raghuram M.Ch. Subbiah Kumar MD Kathamuthu Balamurugan DA Arulmurugan DA Ramiah Krishnan M.Ch. Perichiappan Sivakami BS Eluvathingal Varghese John M.Ch. 《Indian Journal of Thoracic and Cardiovascular Surgery》2006,22(3):178-181
Background Beating heart surgery has now become the commonest technique of doing Coronary Artery Bypass Graft Surgery (CABG) in our country.
It is being used even in such high risk situations like diffuse coronary disease and Critical Left Main stem Stenosis (LMCS)
with good results. The aim of this study is to retrospectively review our results in Off-Pump Coronary Artery Bypass Surgery
(OPCAB) in patients with critical left main stem stenosis.
Methods This study is a retrospective analysis of the data of patients who underwent primary coronary artery bypass surgery. During
the period from April 2003 to September 2005 a total of 64 patients underwent OPCAB procedure for critical LMCS. During the
same period 10 patients underwent CABG on Cardio Pulmonary Bypass (CPB). The age range was 36–77yrs. The sex distribution
was M: F 53∶10. Ten patients were done as emergency. 2 of them were on Intra Aortic Balloon Pump (IABP) support preoperatively.
10 patients were high risk with a Euro score of ≥5.
Results Left Internal Mammary Artery (LIMA) was used in 78% of cases. Average grafts per patient was 2.96. The median ventilation
time was 5.91 hrs. New IABP insertion in postoperative period was required in 1 patient. One patient was reexplored for bleeding.
There was one perioperative myocardial infarction. 57% of patients did not need any blood transfusion. There was no conversion
to CPB. There was no operative mortality. Inotropes were used in ten cases.
Conclusions OPCAB is a safe method of revascularization in patients with critical LMCS. Preoperative IABP is useful in patients with cardiogenic
shock. However, there is a place for CPB in patients needing additional procedures like Mitral Valve repair (MV repair) or
Dor's procedure or when the vessels are very diffusely diseased. Those patients who are unstable despite IABP support may
be managed by Beating heart On Pump (BHOP) technique. 相似文献
4.
5.
6.
7.
Michelle L. DeOliveira Timothy M. Pawlik Ana L. Gleisner Lia Assumpcaom Gaspar J. Lopes-Filho Michael A. Choti 《Journal of gastrointestinal surgery》2007,11(8):970-976
Survival after resection of colorectal liver metastases has traditionally been associated with clinicopathologic factors.
We sought to investigate whether echogenicity of colorectal liver metastasis as assessed by intraoperative ultrasound (IOUS)
was a prognostic factor after hepatic resection. Prospective data on tumor IOUS appearance were collected in 84 patients who
underwent hepatic resection for colorectal liver metastasis. Images were digitally recorded, blindly reviewed, and scored
for echogenicity (hypo-, iso-, or hyperechoic). The median tumor number was 1 and the median tumor size was 5.0 cm. At the
time of surgery, the IOUS appearance of the colorectal liver metastases were hypoechoic in 35 (41.7%) patients, isoechoic
in 37 (44.0%) patients, and hyperechoic in 12 (14.3%) patients. Traditional clinicopathologic prognostic factors were similarly
distributed among the three echogenicity groups (all p > 0.05). Patients with a hypoechoic lesion had a significantly shorter median survival (30.2 months) compared with patients
who had either an isoechoic (53.2 months) or hyperechoic (42.3 months) lesion (p = 0.005). The 5-year survival after hepatic resection of colorectal liver metastasis was also associated with the echogenic
appearance of the lesion (hypoechoic 14.4 vs isoechoic 37.4 vs hyperechoic 46.2%) (p < 0.05). Intraoperative ultrasound echogenicity should be considered a prognostic factor after hepatic resection of metastatic
colorectal cancer.
This study was presented at the 47th annual meeting of The Society for Surgery of the Alimentary Tract, Los Angeles, CA, USA,
22 May 2006. 相似文献
8.
氟西汀与阿米替林治疗105例抑郁障碍病人的双盲对照试验 总被引:6,自引:4,他引:2
目的:评价国产氟西汀的抗抑郁作用及安全性。方法:采用随机、双盲对照、多中心研究,分为国产氟西汀组57例(男性22例,女性35例;年龄40±s13a),口服氟西汀20mg,qd,阿米替林57例(男性27例,女性30例;年龄40±14a),口服阿米替林75mg,bid,疗程6wk。结果:氟西汀治疗抑郁障碍的疗效与阿米替林相当,总有效率分别为85%及92%(P>0.05);氟西汀组的主要副作用有口干、便秘、恶心、心动过速等,但较之阿米替林程度轻且发生率低。结论:氟西汀的抗抑郁作用与阿米替林相当,副作用少,服用方便。 相似文献
9.
Philip Peng FRCPC Manon Choiniere PhD Dominique Dion MD MSc Howard Intrater FRCPC Sandra LeFort PhD Mary Lynch FRCPC May Ong FRCPC Saifee Rashiq MSc DA FRCPC Gregg Tkachuk PhD Yves Veillette FRCPC 《Journal canadien d'anesthésie》2007,54(12):977-984
PURPOSE: The objective of this survey was to examine the services offered by multidisciplinary pain treatment facilities (MPTFs) across Canada and to compare access to care at these MPTFs. METHODS: A MPTF was defined as a clinic that advertised specialized multidisciplinary services for the diagnosis and management of patients with chronic pain, having a minimum of three different health care disciplines (including at least one medical speciality) available and integrated within the facility. The search method included approaching all hospital and rehabilitation centre administrators in Canada, the Insurance Bureau of Canada, the Workplace Safety and Insurance Board or similar body in each province. Designated investigators were responsible for confirming and supplementing MPTFs from the preliminary list for each province. Administrative leads at each eligible MPTF were asked to complete a detailed questionnaire regarding their MPTF infrastructure, clinical, research, teaching and administrative activities. RESULTS: Completed survey forms were received from 102 MPTFs (response rate 85%) with 80% concentrated in major cities, and none in Prince Edward Island and the Territories. The MPTFs offer a wide variety of treatments including non-pharmacological modalities such as interventional, physical and psychological therapy. The median wait time for a first appointment in public MPTFs is six months, which is approximately 12 times longer than non-public MPTFs. Eighteen pain fellowship programs exist in Canadian MPTFs and 64% engage in some form of research activities CONCLUSION: Canadian MPTFs are unable to meet clinical demands of patients suffering from chronic pain, both in terms of regional accessibility and reasonable wait time for patients' first appointment. 相似文献
10.
Susi Elaine Dal''Belo Lorena Rigo Gaspar Patrícia Maria Berardo Gonçalves Maia Campos 《Skin research and technology》2006,12(4):241-246
BACKGROUND/PURPOSE: The polysaccharide-rich composition of Aloe vera extracts (Aloe barbadensis Miller), often used in cosmetic formulations, may impart moisturizing properties to the product. The aim of this study was to evaluate the effect of cosmetic formulations containing different concentrations of freeze-dried Aloe vera extract on skin hydration, after a single and a 1- and 2-week period of application, by using skin bioengineering techniques. METHODS: Stable formulations containing 5% (w/w) of a trilaureth-4 phosphate-based blend were supplemented with 0.10%, 0.25% or 0.50% (w/w) of freeze-dried Aloe vera extract and applied to the volar forearm of 20 female subjects. Skin conditions in terms of the water content of the stratum corneum and of transepidermal water loss (TEWL) (Corneometer CM 825 and Tewameter TM 210) were analysed before and after a single and 1- and 2-week period of daily application. RESULTS: After a single application, only formulations supplemented with 0.25% and 0.50% (w/w) of Aloe vera extract increased the water content of the stratum corneum, while after the 2-week period application, all formulations containing the extract (0.10%, 0.25% and 0.50%) had the same effect, in both cases as compared with the vehicle. TEWL was not modified after a single and after 1- and 2-week period of application, when compared with the vehicle. CONCLUSION: Our results show that freeze-dried Aloe vera extract is a natural effective ingredient for improving skin hydration, possibly through a humectant mechanism. Consequently, it may be used in moisturizing cosmetic formulations and also as a complement in the treatment of dry skin. 相似文献