全文获取类型
收费全文 | 8145篇 |
免费 | 774篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 97篇 |
儿科学 | 286篇 |
妇产科学 | 118篇 |
基础医学 | 570篇 |
口腔科学 | 103篇 |
临床医学 | 1271篇 |
内科学 | 2012篇 |
皮肤病学 | 331篇 |
神经病学 | 720篇 |
特种医学 | 284篇 |
外国民族医学 | 1篇 |
外科学 | 1261篇 |
综合类 | 133篇 |
一般理论 | 6篇 |
预防医学 | 422篇 |
眼科学 | 189篇 |
药学 | 645篇 |
中国医学 | 40篇 |
肿瘤学 | 467篇 |
出版年
2023年 | 112篇 |
2022年 | 165篇 |
2021年 | 250篇 |
2020年 | 182篇 |
2019年 | 170篇 |
2018年 | 263篇 |
2017年 | 211篇 |
2016年 | 251篇 |
2015年 | 259篇 |
2014年 | 345篇 |
2013年 | 432篇 |
2012年 | 446篇 |
2011年 | 439篇 |
2010年 | 365篇 |
2009年 | 410篇 |
2008年 | 404篇 |
2007年 | 319篇 |
2006年 | 342篇 |
2005年 | 275篇 |
2004年 | 232篇 |
2003年 | 233篇 |
2002年 | 193篇 |
2001年 | 195篇 |
2000年 | 141篇 |
1999年 | 155篇 |
1998年 | 99篇 |
1997年 | 154篇 |
1996年 | 142篇 |
1995年 | 134篇 |
1994年 | 112篇 |
1993年 | 113篇 |
1992年 | 141篇 |
1991年 | 104篇 |
1990年 | 76篇 |
1989年 | 79篇 |
1988年 | 88篇 |
1987年 | 67篇 |
1986年 | 62篇 |
1985年 | 78篇 |
1984年 | 69篇 |
1983年 | 51篇 |
1982年 | 43篇 |
1981年 | 27篇 |
1980年 | 42篇 |
1979年 | 36篇 |
1978年 | 29篇 |
1974年 | 26篇 |
1973年 | 28篇 |
1971年 | 26篇 |
1960年 | 21篇 |
排序方式: 共有8956条查询结果,搜索用时 15 毫秒
1.
Discordant Electrocardiogram Left Ventricular Wall Thickness and Strain Findings in Influenza Myocarditis
下载免费PDF全文
![点击此处可从《Echocardiography (Mount Kisco, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Nael Hawwa M.D. Zoran B. Popovic M.D. Ph.D. Hussain A. Isma'eel M.D. 《Echocardiography (Mount Kisco, N.Y.)》2015,32(12):1880-1884
A 42‐year‐old man presented with a viral prodrome and tested positive for influenza A. He rapidly deteriorated developing cardiogenic shock, rhabdomyolysis, and acute kidney injury. Patient improved 1 week later with supportive measures including vasopressors, inotropes, and an intraaortic balloon pump. We report this case as it highlights the discordance between echocardiographic ventricular wall thickening as a result of myocardial edema, and electrocardiographic findings at presentation, with a reversal in findings at time of resolution. Additionally, there was some suggestion of a regional pattern to the reduced longitudinal strain. 相似文献
2.
3.
4.
Femoral access‐related complications during percutaneous transcatheter aortic valve implantation comparing single versus double Prostar XL device closure
下载免费PDF全文
![点击此处可从《Catheterization and cardiovascular interventions》网站下载免费的PDF全文](/ch/ext_images/free.gif)
5.
HOCK LEONG EE MBBS MRCP CHEE LEOK GOH MBBS FRCP KHOO ES-Y. CHAN PHD POR ANG MBBS MRCP 《Dermatologic surgery》2006,32(1):34-40
BACKGROUND: Acquired bilateral nevus of Ota-like macules (Hori's nevus) is a common dyschromatosis among Asian women. Q-switched lasers have been used successfully as a treatment modality. OBJECTIVE: The purpose of this study was to compare the efficacy of using the Q-switched 532 nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser followed by the 1,064 nm laser versus the Q-switched 1,064 nm Nd:YAG laser alone in the treatment of Hori's nevus. METHODS: This is a prospective left-right comparative study. Ten women with bilateral Hori's nevus were recruited and treated with a combination of the Q-switched 532 and 1,064 nm Nd:YAG lasers on the right cheek and the Q-switched 1,064 nm Nd:YAG laser alone on the left cheek. Only one laser treatment session was performed. The degree of pigmentation was objectively recorded with a mexameter. Subjective assessment was made by both patients and two blinded, nontreating dermatologists. RESULTS: At 6 months, there was a statistically significant difference (p = .009) of 35.10 points using objective mexameter measurements between the two sides, favoring the side treated with a combination of 532 and 1,064 nm laser treatment. Subjective grading by the patients and blinded dermatologists also confirmed that combination therapy was more successful after one treatment. Although combination treatment had a higher incidence of mild postinflammatory changes, this disappeared within 2 months. CONCLUSIONS: Concurrent use of the Q-switched 532 nm Nd:YAG laser in combination with the 1,064 nm laser is more effective in pigment clearance than the Q-switched 1,064 nm Nd:YAG laser alone for Hori's nevi. 相似文献
6.
Dr. Arthur A. Dunk MRCP Natasha Kyprianou MSc Peter Davies PhD Howard C. Thomas PhD FRCP 《Digestive diseases and sciences》1988,33(4):472-476
Castrated or sham-operated male athymic mice were inoculated with cells from the human hepatocellular carcinoma cell line PLC/PRF/5. There were no significant differences between the two groups with respect to the number of animals developing tumors, the time to tumor development, or the subsequent rate of increase in either tumor base area or mouse serum alpha-fetoprotein concentration. Androgen receptors were assayed in nuclei obtained from three separate liver cancer cell lines and from normal adult human liver. Similar concentrations, ranging from 235 to 550 fmol/mg DNA, of nuclear androgen receptors were detected in all tissues. Low percentages of androgen receptors were retained on DNA-cellulose. Although the presence of receptors implies the potential for metabolic effects of androgens in normal and malignant liver, our in vivostudies suggest that castration does not alter significantly the growth of liver cancer xenografts in athymic mice. 相似文献
7.
8.
Mozammil Hussain Raghu N. Natarajan Amir H. Fayyazi Brian R. Braaksma Gunnar B.J. Andersson Howard S. An 《The spine journal》2009,9(12):1016-1023
Background contextAnterior corpectomy and reconstruction with bone graft and a rigid screw-plate construct is an established procedure for treatment of cervical neural compression. Despite its reliability in relieving symptoms, there is a high rate of construct failure, especially in multilevel cases.PurposeThere has been no study evaluating the biomechanical effects of screw angulation on construct stability; this study investigates the C4–C7 construct stability and load-sharing properties among varying screw angulations in a rigid plate-screw construct.Study designA finite element model of a two-level cervical corpectomy with static anterior cervical plate.MethodsA three-dimensional finite element (FE) model of an intact C3–T1 segment was developed and validated. From this intact model, a fusion model (two-level [C5, C6] anterior corpectomy) was developed and validated. After corpectomy, allograft interbody fusion with a rigid anterior screw-plate construct was created from C4 to C7. Five additional FE models were developed from the fusion model corresponding to five different combinations of screw angulations within the vertebral bodies (C4, C7): (0°, 0°), (5°, 5°), (10°, 10°), (15°, 15°), and (15°, 0°). The fifth fusion model was termed as a hybrid fusion model.ResultsThe stability of a two-level corpectomy reconstruction is not dependent on the position of the screws. Despite the locked screw-plate interface, some degree of load sharing is transmitted to the graft. The load seen by the graft and the shear stress at the bone-screw junction is dependent on the angle of the screws with respect to the end plate. Higher stresses are seen at more divergent angles, particularly at the lower level of the construct.ConclusionThis study suggests that screw divergence from the end plates not only increases load transmission to the graft but also predisposes the screws to higher shear forces after corpectomy reconstruction. In particular, the inferior screw demonstrated larger stress than the upper-level screws. In the proposed hybrid fusion model, lower stresses on the bone graft, end plates, and bone-screw interface were recorded, inferring lower construct failure (end-plate fractures and screw pullout) potential at the inferior construct end. 相似文献
9.
10.
M Vijaya Lakshmi MRCP G V Sridharan MRCP D Butterworth MRCP 《International journal of clinical practice》1993,47(3):164-165
Gallstones are common and their incidence increases with age.1 Fifty per cent of these stones are in the common bile duct (CBD) in the elderly.2 Most of them are silent but with time there is an increasing chance of developing symptoms which are more likely to be serious in the elderly.3 Failure to relieve mechanical obstruction of bile flow may lead to secondary biliary cirrhosis.4 It has been estimated that on average secondary biliary cirrhosis develops some seven years after the onset of obstruction from a stricture, four and half years after gallstone obstruction and 10 months after the onset of malignant stricture.5 The characteristic features are the pathological findings of portal-portal linkages, with a pattern of monolobular cirrhosis and the preservation of normal vascular relationships.6 Secondary biliary cirrhosis may lead to hepatic insufficiency and portal hypertension with the resultant complications, such as bleeding oesophageal varices, hypersplenism with pancytopenia, ascites and encephalopathy. We describe a patient in whom the diagnosis was not suspected until laparotomy and confirmed only at autopsy. 相似文献