全文获取类型
收费全文 | 19331篇 |
免费 | 975篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 193篇 |
儿科学 | 796篇 |
妇产科学 | 459篇 |
基础医学 | 2732篇 |
口腔科学 | 308篇 |
临床医学 | 1341篇 |
内科学 | 3921篇 |
皮肤病学 | 547篇 |
神经病学 | 1331篇 |
特种医学 | 781篇 |
外国民族医学 | 2篇 |
外科学 | 2466篇 |
综合类 | 501篇 |
一般理论 | 9篇 |
预防医学 | 1216篇 |
眼科学 | 637篇 |
药学 | 1566篇 |
中国医学 | 93篇 |
肿瘤学 | 1440篇 |
出版年
2022年 | 207篇 |
2021年 | 409篇 |
2020年 | 219篇 |
2019年 | 272篇 |
2018年 | 452篇 |
2017年 | 323篇 |
2016年 | 400篇 |
2015年 | 482篇 |
2014年 | 599篇 |
2013年 | 711篇 |
2012年 | 1044篇 |
2011年 | 1155篇 |
2010年 | 656篇 |
2009年 | 524篇 |
2008年 | 871篇 |
2007年 | 937篇 |
2006年 | 939篇 |
2005年 | 823篇 |
2004年 | 776篇 |
2003年 | 688篇 |
2002年 | 735篇 |
2001年 | 571篇 |
2000年 | 591篇 |
1999年 | 517篇 |
1998年 | 171篇 |
1997年 | 139篇 |
1996年 | 122篇 |
1995年 | 100篇 |
1992年 | 274篇 |
1991年 | 259篇 |
1990年 | 233篇 |
1989年 | 245篇 |
1988年 | 248篇 |
1987年 | 209篇 |
1986年 | 222篇 |
1985年 | 206篇 |
1984年 | 157篇 |
1983年 | 118篇 |
1982年 | 94篇 |
1979年 | 150篇 |
1978年 | 120篇 |
1977年 | 109篇 |
1976年 | 109篇 |
1975年 | 113篇 |
1974年 | 134篇 |
1973年 | 136篇 |
1972年 | 124篇 |
1971年 | 126篇 |
1970年 | 117篇 |
1969年 | 116篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Apoorva Challa Neeraj Mahajan Seema Sood Arti Kapil Bimal Kumar Das Vishnubhatla Sreenivas Somesh Gupta 《Indian journal of medical microbiology》2022,40(3):433-435
Treatment guidelines for management of uncomplicated gonorrhoeae have been recently modified owing to alarming upsurge in azithromycin resistance. This study investigated the prevalence and genetic determinants of gonococcal azithromycin resistance in India. Four (5.7%) of 70 gonococcal isolates were resistant to azithromycin. Of 16 isolates investigated for molecular mechanisms of resistance, 13 (81.3%) and 6 (37.5%) isolates exhibited mutations in coding and promoter regions of mtrR gene, respectively. However, ermA, ermB and ermC genes or mutations in rrl gene were absent in all isolates. Azithromycin resistance is low in India posing no immediate threat to use of dual-therapy for syndromic management. 相似文献
2.
Troppmair Teresa Egger J. Krösbacher A. Zanvettor A. Schinnerl A. Neumayr A. Baubin M. 《Der Anaesthesist》2022,71(4):272-280
Die Anaesthesiologie - Die Qualität eines Rettungssystems zeichnet sich auch durch den effizienten Einsatz seiner personellen und Fahrzeugressourcen aus. So können im berechtigten Fall... 相似文献
3.
Josh Greenstein Devjani Das Josie Acuna Monica Kapoor Cara Brown Abbas Husain Brendan Lally Barry Hahn 《The American journal of emergency medicine》2019,37(2):313-316
Background
In the emergency department, rib fractures are a common finding in patients who sustain chest trauma. Rib fractures may be a sign of significant, underlying pathology, especially in the elderly patients where rib fractures are associated with significant morbidity and mortality. To date, no studies have evaluated the ability of ultrasound to detect rib fractures using cadaver models and subsequently use this model as a teaching tool.Objectives
The purpose of this study was to determine if it is possible to generate rib fractures on cadaver models which could be accurately identified using ultrasound.Methods
This was a cross-sectional study performed during one session at a cadaver lab. A single hemithorax from four adult cadavers were used as models. Single rib fractures on each of rib five through eight were created. Four subjects, blinded to the normal versus fractured ribs, were asked to identify the presence of a fracture on each rib.Results
A total of 8 of 16 potential ribs had fractured induced by study staff. Mean accuracy was 55% for all subjects. The overall sensitivity and specificity for detecting rib fractures was 50% (CI: 31.89–68.11) and 59.38% (CI: 35.69–73.55) respectively. The overall PPV and NPV was 55.17% and 54.29% respectively.Conclusions
In this pilot study, subjects were not able to detect induced rib fractures using ultrasound on cadaver models. The use of this model as a teaching tool in the detection of rib fractures requires further investigation. 相似文献4.
5.
Samo Lasi
Filip Szczepankiewicz Erica Dall'Armellina Arka Das Christopher Kelly Sven Plein Jürgen E. Schneider Markus Nilsson Irvin Teh 《NMR in biomedicine》2020,33(2)
Motion is a major confound in diffusion‐weighted imaging (DWI) in the body, and it is a common cause of image artefacts. The effects are particularly severe in cardiac applications, due to the nonrigid cyclical deformation of the myocardium. Spin echo‐based DWI commonly employs gradient moment‐nulling techniques to desensitise the acquisition to velocity and acceleration, ie, nulling gradient moments up to the 2nd order (M2‐nulled). However, current M2‐nulled DWI scans are limited to encode diffusion along a single direction at a time. We propose a method for designing b‐tensors of arbitrary shapes, including planar, spherical, prolate and oblate tensors, while nulling gradient moments up to the 2nd order and beyond. The design strategy comprises initialising the diffusion encoding gradients in two encoding blocks about the refocusing pulse, followed by appropriate scaling and rotation, which further enables nulling undesired effects of concomitant gradients. Proof‐of‐concept assessment of in vivo mean diffusivity (MD) was performed using linear and spherical tensor encoding (LTE and STE, respectively) in the hearts of five healthy volunteers. The results of the M2‐nulled STE showed that (a) the sequence was robust to cardiac motion, and (b) MD was higher than that acquired using standard M2‐nulled LTE, where diffusion‐weighting was applied in three orthogonal directions, which may be attributed to the presence of restricted diffusion and microscopic diffusion anisotropy. Provided adequate signal‐to‐noise ratio, STE could significantly shorten estimation of MD compared with the conventional LTE approach. Importantly, our theoretical analysis and the proposed gradient waveform design may be useful in microstructure imaging beyond diffusion tensor imaging where the effects of motion must be suppressed. 相似文献
6.
Sameer Arora Kamal Shemisa Muthiah Vaduganathan Arman Qamar Ankur Gupta Sushil K. Garg Dharam J. Kumbhani Helen Mayo Houman Khalili Ambarish Pandey Sandeep R. Das 《Journal of the American College of Cardiology》2019,73(19):2454-2464
Ticagrelor is a cornerstone of modern antithrombotic therapy alongside aspirin in patients with acute coronary syndrome and after percutaneous coronary intervention. Adverse effects such as bleeding and dyspnea have been associated with premature ticagrelor discontinuation, which may limit any potential advantage of ticagrelor over clopidogrel. The randomized trials of ticagrelor captured adverse events, offering the opportunity to more precisely quantify these effects across studies. Therefore, a meta-analysis of 4 randomized clinical trials of ticagrelor conducted between January 2007 and June 2017 was performed to quantify the incidence and causes of premature ticagrelor discontinuation. Among 66,870 patients followed for a median 18 months, premature ticagrelor discontinuation was seen in 25%; bleeding was the most common cause of discontinuation followed by dyspnea. Versus the comparators, the relative risk of dyspnea-related discontinuation during follow-up was 6.4-fold higher, the relative risk of bleeding was 3.2-fold higher, and the relative risk of discontinuation due to any adverse event was 59% higher for patients receiving ticagrelor. Understanding these potential barriers to adherence to ticagrelor is crucial for informed patient-physician decision making and can inform future efforts to improve ticagrelor adherence. This review discusses the incidence, causes, and biological mechanisms of ticagrelor-related adverse effects and offers strategies to improve adherence to ticagrelor. 相似文献
7.
Metabolic abnormalities of gastrointestinal mucosa in celiac disease: An in vitro proton nuclear magnetic resonance spectroscopy study
下载免费PDF全文
![点击此处可从《Journal of gastroenterology and hepatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
8.
Dr. H. Ptok R. Steinert F. Meyer K.-P. Kröll C. Scheele F. Köckerling I. Gastinger H. Lippert 《Der Chirurg》2006,77(8):709-717
BACKGROUND: The laparoscopic resection of rectal cancer shows morbidity and oncological safety comparable to the open approach, but morbidity increases after conversion to open resection. No oncological long-term results are available for the latter patients. METHODS: From 01/01/2000-31/12/2002, patients with curatively resected rectal cancer enrolled in a observational study were evaluated for morbidity, mortality, tumor- and local recurrence rate, paying attention to patients with conversion from laparoscopic to open resection. RESULTS: 237 (3.3%) of 7,189 patients underwent laparoscopic resection (ITT). These patients showed significantly more T1/2 tumors (P<0.001) in earlier UICC stages (P<0.001) than open resected patients. 35 (14.8%) of 237 laparoscopic procedures were converted. Compared with patients receiving complete laparoscopic or open resection, these patients showed significantly higher frequencies of intraoperative (P<0.001) and general postoperative complications (P=0.003) as well as the highest overall morbidity (P=0.031). After a median follow-up of 30.1 months, the highest 5-year local recurrence rate was found in the converted group (16.0%). The laparoscopically resected patients showed a local recurrence rate of 3.3%, patients with open resection of 12.4% (P=0.082). The disease-free survival rate did not differ between the groups (P=0.585). CONCLUSION: Laparoscopic resection of rectal cancer provides oncological results similar to open resection. After conversion, the short and oncological long-term outcomes were worse. Considering a conversion rate of 15%, only a strict indication for the laparoscopic approach can be allowed, and laparoscopic resection should be performed at centers. 相似文献
9.
10.