全文获取类型
收费全文 | 1708篇 |
免费 | 287篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 101篇 |
妇产科学 | 19篇 |
基础医学 | 91篇 |
口腔科学 | 30篇 |
临床医学 | 282篇 |
内科学 | 577篇 |
皮肤病学 | 60篇 |
神经病学 | 175篇 |
特种医学 | 279篇 |
外科学 | 195篇 |
综合类 | 31篇 |
预防医学 | 57篇 |
眼科学 | 17篇 |
药学 | 53篇 |
中国医学 | 1篇 |
肿瘤学 | 53篇 |
出版年
2024年 | 9篇 |
2023年 | 52篇 |
2022年 | 13篇 |
2021年 | 27篇 |
2020年 | 91篇 |
2019年 | 14篇 |
2018年 | 89篇 |
2017年 | 70篇 |
2016年 | 68篇 |
2015年 | 60篇 |
2014年 | 94篇 |
2013年 | 109篇 |
2012年 | 44篇 |
2011年 | 36篇 |
2010年 | 76篇 |
2009年 | 108篇 |
2008年 | 41篇 |
2007年 | 44篇 |
2006年 | 42篇 |
2005年 | 25篇 |
2004年 | 13篇 |
2003年 | 11篇 |
2002年 | 14篇 |
2001年 | 32篇 |
2000年 | 12篇 |
1999年 | 25篇 |
1998年 | 80篇 |
1997年 | 95篇 |
1996年 | 78篇 |
1995年 | 68篇 |
1994年 | 49篇 |
1993年 | 52篇 |
1992年 | 28篇 |
1991年 | 14篇 |
1990年 | 25篇 |
1989年 | 53篇 |
1988年 | 42篇 |
1987年 | 26篇 |
1986年 | 21篇 |
1985年 | 20篇 |
1984年 | 16篇 |
1983年 | 9篇 |
1982年 | 14篇 |
1981年 | 14篇 |
1980年 | 14篇 |
1979年 | 8篇 |
1978年 | 11篇 |
1977年 | 13篇 |
1976年 | 11篇 |
1971年 | 8篇 |
排序方式: 共有2034条查询结果,搜索用时 15 毫秒
21.
22.
GA Smith SD Strausbaugh C Harbeck-Weber DM Cohen BJ Shields JD Powers 《Pediatrics》1997,100(5):825-830
OBJECTIVE: To compare the effectiveness of three new topical anesthetics that do not contain cocaine (prilocaine-phenylephrine, tetracaine-phenylephrine [tetraphen], and tetracaine-lidocaine-phenylephrine) to that of tetracaine-adrenaline-cocaine (TAC) during laceration repair in children. DESIGN: Prospective, randomized, double-blind clinical trial. SETTING: The emergency department of an urban children's hospital. PARTICIPANTS: Children 1 year of age or older with a laceration = 5 cm in length that required suturing. Intervention. A total of 240 children were randomly assigned to one of four treatment groups. OUTCOME MEASURES: Pain felt during suturing was scored by suture technicians, research assistants, parents, and patients >/= 5 years of age using a visual analogue scale (VAS). Suture technicians, research assistants, and parents also scored pain using a seven-point Likert scale. In addition, suture technicians completed an anesthetic effectiveness scale. RESULTS: There was consistently no difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. A statistically significant difference was seen among anesthetics when comparing VAS and Likert scale scores of suture technicians and Likert scale scores of research assistants. Based on post hoc analyses, these statistically significant differences were between TAC and prilocaine-phenylephrine (suture technician VAS and Likert scale) and between TAC and tetracaine-lidocaine-phenyl-ephrine (suture technician Likert scale), but not between TAC and tetraphen. When power analyses were performed using alpha = 0.05 and beta = 0.20, it was possible to detect a difference of 1.2 VAS units for each of the observer groups. Based on anesthetic effectiveness scale scores, the three new topical preparations collectively performed significantly better on the face and scalp than on the extremities (relative risk = 1.83; 95% confidence interval 1.20 < relative risk < 2.79). CONCLUSION: This study demonstrated the effectiveness and safety of three new non-cocaine-containing topical anesthetics. Consistently, there was no statistical difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. Tetraphen offers an effective alternative to TAC during laceration repair in children. 相似文献
23.
Increased placental apoptosis in intrauterine growth restriction 总被引:2,自引:0,他引:2
Stephen C. Smith MB ChB Philip N. Baker DM E.Malcolm Symonds MD 《American journal of obstetrics and gynecology》1997,177(6):1395-1401
OBJECTIVES: Our purpose was to investigate a possible role for apoptosis in the pathophysiologic mechanisms of intrauterine growth restriction. STUDY DESIGN: Placental samples were obtained from 43 uncomplicated third-trimester pregnancies and from 26 pregnancies complicated by intrauterine growth restriction. The definition used to identify cases of intrauterine growth restriction depended on three criteria: clinical evidence of suboptimal growth, ultrasonographic evidence of deviation from an appropriate growth percentile, and individualized birth weight ratios <10th percentile. Light microscopy was used to quantify the incidence of apoptosis. Electron microscopy and TUNEL (terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick end labeling) staining were used to confirm the occurrence of apoptosis. RESULTS: Quantification of apoptosis (medians and interquartile ranges) resulted in the following values: normal third trimester (n = 43) 0.14% of cells (0.08% to 0.20%) and intrauterine growth restriction third trimester (n = 26) 0.24% of cells (0.16% to 0.29%). The incidence of apoptosis was significantly higher in placentas from pregnancies with intrauterine growth restriction compared with normal third-trimester placentas (p < 0.01, Mann Whitney U test). CONCLUSIONS: These results suggest that apoptosis may play a role in the pathophysiologic mechanisms of intrauterine growth restriction.(Am J Obstet Gynecol 1997;177:401) 相似文献
24.
25.
26.
27.
Wearable monitors for patients following discharge from an intensive care unit: practical lessons learnt from an observational study 下载免费PDF全文
28.
Nagaraja Moorthy DM Rajiv Ananthakrishna DM Dattatreya P. V. Rao DM Satvic C. Manjunath DM Manjunath C. Nanjappa DM 《Echocardiography (Mount Kisco, N.Y.)》2018,35(3):388-390
Intermittent dysfunction of mechanical mitral valve prosthesis is an uncommon condition. It carries serious clinical implications if unrecognized. Here, we present a case of a 28‐year‐old female with a history of rheumatic multivalvular disease, for which she had undergone double valve replacement and tricuspid annuloplasty. Six months later, she presented with heart failure. Clinical examination revealed intermittent loss of closing clicks followed by a pansystolic murmur at the apex, suggestive of mitral prosthetic valve dysfunction. We highlight the echocardiographic findings of paroxysmal mitral valvular regurgitation secondary to prosthetic valve malfunction secondary to prosthetic valve thrombosis. 相似文献
29.
False positive retroaortic left circumflex coronary artery in a patient with atrial septal defect 下载免费PDF全文
Saurabh Kumar Gupta MD DM Anunay Gupta MD DM Sivasubramanian Ramakrishnan MD DM Shyam S. Kothari MD DM 《Echocardiography (Mount Kisco, N.Y.)》2017,34(5):799-801
Retroaortic course of coronary artery is a relative contraindication for device closure of an atrial septal defect. In this brief report, we demonstrate, for the first time, inferior aortic recess mimicking retroaortic left circumflex coronary artery in a patient with atrial septal defect. This distinction is important to avoid spurious diagnosis of anomalous coronary artery denying patient a chance of nonsurgical closure of atrial septal defect. 相似文献
30.
Roopali Khanna MD DM Pujan Shah MD Mousam Dey MD Pravin K. Goel MD DM Puneet Goyal MD DM Shantanu Pandey MD McH 《Echocardiography (Mount Kisco, N.Y.)》2017,34(7):1107-1109
Sinus of Valsalva aneurysm is a rare congenital cardiac abnormality and is usually diagnosed when it ruptures. An asymptomatic 55‐year‐old male of unruptured sinus of Valsalva aneurysm of noncoronary cusp was on medical follow‐up. At 2‐year follow‐up, there was thrombus formation in the aneurysm, mimicking right atrium tumor on 2D transthoracic echocardiography. Cardiac computed tomography showed filling defect in the aneurysm suggestive of thrombus. Considering the high risk of systemic emboli surgery was performed, and aneurysm was repaired with Dacron patch. 相似文献