全文获取类型
收费全文 | 1657篇 |
免费 | 143篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 41篇 |
妇产科学 | 17篇 |
基础医学 | 165篇 |
口腔科学 | 100篇 |
临床医学 | 128篇 |
内科学 | 530篇 |
皮肤病学 | 18篇 |
神经病学 | 62篇 |
特种医学 | 46篇 |
外国民族医学 | 1篇 |
外科学 | 241篇 |
综合类 | 32篇 |
预防医学 | 76篇 |
眼科学 | 75篇 |
药学 | 168篇 |
中国医学 | 13篇 |
肿瘤学 | 89篇 |
出版年
2024年 | 5篇 |
2023年 | 40篇 |
2022年 | 65篇 |
2021年 | 88篇 |
2020年 | 67篇 |
2019年 | 87篇 |
2018年 | 97篇 |
2017年 | 37篇 |
2016年 | 86篇 |
2015年 | 79篇 |
2014年 | 99篇 |
2013年 | 106篇 |
2012年 | 161篇 |
2011年 | 169篇 |
2010年 | 75篇 |
2009年 | 56篇 |
2008年 | 73篇 |
2007年 | 83篇 |
2006年 | 75篇 |
2005年 | 53篇 |
2004年 | 52篇 |
2003年 | 39篇 |
2002年 | 37篇 |
2001年 | 18篇 |
2000年 | 10篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1997年 | 3篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 9篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有1815条查询结果,搜索用时 15 毫秒
31.
32.
33.
Yakoob J Jafri W Jafri N Khan R Islam M Beg MA Zaman V 《The American journal of tropical medicine and hygiene》2004,70(4):383-385
This study was designed to examine stool specimens of irritable bowel syndrome (IBS) patients for Blastocystis hominis, a common intestinal parasite. One hundred fifty patients were enrolled, 95 IBS cases and 55 controls. These patients provided a medical history, and underwent physical and laboratory evaluations that included stool microscopy and culture for B. hominis and colonoscopy. The 95 cases (51 males and 44 females) had a mean +/- SD age of 37.8 +/- 13.2 years. Stool microscopy was positive for B. hominis in 32% (30 of 95) of the cases and 7% (4 of 55) of the controls (P = 0.001). Stool culture was positive in 46% (44 of 95) of the cases and 7% (4 of 55) of the controls (P < 0.001). Stool culture for B. hominis in IBS was more sensitive than microscopy (P < 0.001). Blastocystis hominis was frequently demonstrated in the stool samples of IBS patients; however, its significance in IBS still needs to be investigated. Stool culture has a higher positive yield for B. hominis than stool microscopy. 相似文献
34.
Sean P. Collins MD MSc Phillip D. Levy MD MPH Gregory J. Fermann MD Michael M. Givertz MD Jennifer M. Martindale MD MSc Peter S. Pang MD MSc Alan B. Storrow MD Deborah D. Diercks MD MSc G. Michael Felker MD Gregg C. Fonarow MD David J. Lanfear MD MSc Daniel J. Lenihan MD JoAnn M. Lindenfeld MD W. Frank Peacock MD Douglas M. Sawyer MD PhD John R. Teerlink MD Javed Butler MD MPH MBA 《Academic emergency medicine》2018,25(1):85-93
Each year over one million patients with acute heart failure (AHF) present to a United States emergency department (ED). The vast majority are hospitalized for further management. The length of stay and high postdischarge event rate in this cohort have changed little over the past decade. Therapeutic trials have failed to yield substantive improvement in postdischarge outcomes; subsequently, AHF care has changed little in the past 40 years. Prior research studies have been fragmented as either “inpatient” or “ED‐based.” Recognizing the challenges in identification and enrollment of ED patients with AHF, and the lack of robust evidence to guide management, an AHF clinical trials network was developed. This network has demonstrated, through organized collaboration between cardiology and emergency medicine, that many of the hurdles in AHF research can be overcome. The development of a network that supports the collaboration of acute care and HF researchers, combined with the availability of federally funded infrastructure, will facilitate more efficient conduct of both explanatory and pragmatic trials in AHF. Yet many important questions remain, and in this document our group of emergency medicine and cardiology investigators have identified four high‐priority research areas. 相似文献
35.
Poly(methacrylic acid) (P(MAA)), poly(acrylamide) (P(AAm)) and poly(3-acrylamidopropyltrimethyl ammonium chloride) (P(APTMACl)) were synthesized as anionic, neutral and cationic hydrogels, respectively. The synthesized hydrogels have the ability to be used as absorbents for the removal of selected heavy metal ions such as Cu2+, Co2+, Ni2+ and Zn2+ from aqueous media. Absorption studies revealed that the absorption of metal ions by the hydrogels followed the order Cu2+ > Ni2+ > Co2+ > Zn2+. For the mechanism of absorption, both Freundlich and Langmuir absorption isotherms were applied. Metal ion entrapped hydrogels were treated using an in situ chemical reduction method in order to convert the metal ions into metal nanoparticles for the synthesis of hybrid hydrogels. The synthesis and morphology were confirmed using FT-IR and SEM, while the absorbed metal amounts were measured using TGA and AAS. The hybrid hydrogels were further used as catalysts for the reduction of macro (methylene blue, methyl orange and congo red) and micro (4-nitrophenol and nitrobenzene) pollutants from the aqueous environment. The catalytic performance and re-usability of the hybrid hydrogels were successfully investigated.Poly(methacrylic acid) (P(MAA)), poly(acrylamide) (P(AAm)) and poly(3-acrylamidopropyltrimethyl ammonium chloride) (P(APTMACl)) were synthesized as anionic, neutral and cationic hydrogels respectively. 相似文献
36.
Aims
Cataract surgery is one of the most common surgeries performed, but its overuse has been reported. The threshold for cataract surgery has become increasingly lenient; therefore, the selection process and surgical need has been questioned. The aim of this study was to evaluate the changes associated with cataract surgery in patient-reported vision-related quality of life (VR-QoL).Methods
A prospective cohort study was conducted. Consecutive patients referred to cataract clinics in an NHS unit in Scotland were identified. Those listed for surgery were invited to complete a validated questionnaire (TyPE) to measure VR-QoL pre- and post-operatively. TyPE has five different domains (near vision, distance vision, daytime driving, night-time driving, and glare) and a global score of vision. The influence of pre-operative visual acuity (VA) levels, vision, and lens status of the fellow eye on changes in VR-QoL were explored.Results
A total of 320 listed patients were approached, of whom 36 were excluded. Among the 284 enrolled patients, 229 (81%) returned the questionnaire after surgery. Results revealed that the mean overall vision improved, as reported by patients. Improvements were also seen in all sub-domains of the questionnaire.Conclusion
The majority of patients appear to have improvement in patient-reported VR-QoL, including those with good pre-operative VA and previous surgery to the fellow eye. VA thresholds may not capture the effects of the quality of life on patients. This information can assist clinicians to make more informed decisions when debating over the benefits of listing a patient for cataract extraction. 相似文献37.
Javed Hussain Farooqui Archana Koul Ranjan Dutta Noshir Minoo Shroff 《Saudi Journal of Ophthalmology》2015,29(4):264-269
Purpose
Visual performance following toric intraocular lens implantation for cataract with moderate and severe astigmatism.Setting
Cataract services, Shroff Eye Centre, New Delhi, India.Design
Case series.Method
This prospective study included 64 eyes of 40 patients with more than 1.50 dioptre (D) of pre-existing corneal astigmatism undergoing phacoemulsification with implantation of the AcrySof® toric IntraOcular Lens (IOL). The unaided visual acuity (UCVA), best corrected visual acuity (BCVA), residual refractive sphere and refractive cylinders were evaluated. Toric IOL axis and alignment error was measured by slit lamp method and Adobe Photoshop (version 7) method. Patient satisfaction was evaluated using a satisfaction questionnaire at 3 months.Results
The mean residual refractive astigmatism was 0.57 D at the final follow-up of 3 months. Mean alignment error was 3.44 degrees (SD = 2.60) by slit lamp method and 3.88 degrees (SD = 2.86) by Photoshop method. Forty-six (71.9%) eyes showed misalignment of 5 degrees or less, and 60 (93.8%) eyes showed misalignment of 10 degrees or less. The mean log MAR UCVA at 1st post-op day was 0.172 (SD = 0.02), on 7th post-op day was 0.138 (SD = 0.11), and on 30th post-op day was 0.081 (SD = 0.11). The mean log MAR BCVA at three months was −0.04 (SD = 0.76).Conclusion
We believe that implantation of AcrySof® toric IOL is an effective, safe and predictable method to correct high amounts of corneal astigmatism during cataract surgery. 相似文献38.
39.
40.
The prognostic importance of different definitions of worsening renal function in congestive heart failure 总被引:13,自引:0,他引:13
Gottlieb SS Abraham W Butler J Forman DE Loh E Massie BM O'connor CM Rich MW Stevenson LW Young J Krumholz HM 《Journal of cardiac failure》2002,8(3):136-141
BACKGROUND: Worsening renal function in patients hospitalized for heart failure portends a poor prognosis. However, criteria used to define worsening renal function are arbitrary, and the implications of different definitions remain unclear. We therefore compared the prognostic importance of various definitions of worsening renal function in 1,002 patients hospitalized for congestive heart failure (CHF). METHODS AND RESULTS: The patient population was 49% female, aged 67 +/- 15 years. Twenty-three percent had a prior history of renal failure, 73% had known depressed ejection fraction, and 63% had known CHF. On admission to the hospital, 47% were receiving ACE inhibitors, 22% beta-blockers, 70% diuretics and 6% NAID's. 72% developed increased serum creatinine during the hospitalization, with 20% developing an increase of > or = 0.5 mg/dL. Worsening renal function predicted both in-hospital mortality and length of stay > 10 days. Even an increased creatinine of 0.1 mg/dL was associated with worse outcome. Sensitivity for death decreased from 92% to 65% as the threshold for increased creatinine was raised from 0.1 to 0.5 mg/dL, with specificity increasing from 28% to 81%. At a threshold of a 0.3 mg/dL increase, sensitivity was 81% and specificity was 62% for death and 64% and 65% for length of stay >10 days. Adding a requirement of final creatinine of > or = 1.5 mg/dL improved specificity. CONCLUSIONS: This analysis demonstrates that any detectable decrease in renal function is associated with increased mortality and prolonged hospital stay. This suggests that therapeutic interventions which improve renal function might be beneficial. 相似文献