全文获取类型
收费全文 | 8882篇 |
免费 | 690篇 |
国内免费 | 107篇 |
专业分类
耳鼻咽喉 | 91篇 |
儿科学 | 111篇 |
妇产科学 | 315篇 |
基础医学 | 580篇 |
口腔科学 | 226篇 |
临床医学 | 1094篇 |
内科学 | 1835篇 |
皮肤病学 | 111篇 |
神经病学 | 206篇 |
特种医学 | 309篇 |
外国民族医学 | 1篇 |
外科学 | 1958篇 |
综合类 | 697篇 |
预防医学 | 1297篇 |
眼科学 | 157篇 |
药学 | 492篇 |
中国医学 | 52篇 |
肿瘤学 | 147篇 |
出版年
2024年 | 15篇 |
2023年 | 175篇 |
2022年 | 327篇 |
2021年 | 490篇 |
2020年 | 505篇 |
2019年 | 469篇 |
2018年 | 465篇 |
2017年 | 376篇 |
2016年 | 349篇 |
2015年 | 348篇 |
2014年 | 776篇 |
2013年 | 730篇 |
2012年 | 446篇 |
2011年 | 540篇 |
2010年 | 449篇 |
2009年 | 406篇 |
2008年 | 373篇 |
2007年 | 339篇 |
2006年 | 302篇 |
2005年 | 249篇 |
2004年 | 264篇 |
2003年 | 204篇 |
2002年 | 155篇 |
2001年 | 107篇 |
2000年 | 112篇 |
1999年 | 90篇 |
1998年 | 68篇 |
1997年 | 67篇 |
1996年 | 67篇 |
1995年 | 57篇 |
1994年 | 54篇 |
1993年 | 38篇 |
1992年 | 35篇 |
1991年 | 25篇 |
1990年 | 25篇 |
1989年 | 29篇 |
1988年 | 19篇 |
1987年 | 22篇 |
1986年 | 11篇 |
1985年 | 15篇 |
1984年 | 8篇 |
1983年 | 15篇 |
1982年 | 12篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 11篇 |
1978年 | 11篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1973年 | 2篇 |
排序方式: 共有9679条查询结果,搜索用时 15 毫秒
1.
《Journal of cranio-maxillo-facial surgery》2020,48(2):170-175
AimThe purpose of this study was to evaluate the efficiency of pyramidal and posterior osseous release (PPOR) for maxillary impaction using an ultrasonic bone-cutting device after Le Fort I (LFI) osteotomy.Materials and methodsIn total, 31 Japanese adults with jaw deformities, diagnosed as having maxillary excess with mandibular prognathism or deficiency, underwent LFI osteotomy and bilateral sagittal split osteotomy. The patients were divided into two groups: a trimming group (15 patients, four men and 11 women; mean age 24.8 years) and a PPOR group (16 patients, seven men and nine women; mean age 22.8 years). In the trimming group, osseous interference around the descending palatine artery (DPA) was removed using forceps, rounding bur, and reciprocating rasp. The PPOR technique was used to remove osseous fragments created by V-shaped osteotomy around the DPA following vertical osteotomy behind the DPA using an ultrasonic bone-cutting device (Variosurg 3; NSK, Tochigi, Japan). The operative times for maxillary osteotomy, total operative times (including bilateral sagittal split osteotomy), and total blood loss were assessed.ResultsThe mean planned amounts of maxillary impaction were 4.37 ± 1.27 mm in the trimming group and 4.38 ± 1.36 mm in the PPOR group (p = 0.98). The mean maxillary operative time for the PPOR group was significantly shorter, by 25.5% (p < 0.001). Total operative time for the PPOR group was also significantly shorter, by 24.3% (p < 0.001). Mean blood loss was significantly lower in the PPOR group than in the trimming group (p = 0.003).ConclusionThe PPOR technique for maxillary impaction after LFI osteotomy shortened the operative time and enabled secure reduction of the maxilla in patients who required the treatment of maxillary impaction with preservation of the DPA bundle. 相似文献
2.
Purpose: To describe how central venous access devices (CVADs) are utilized for ambulatory oncology patients and to evaluate the rate of complications. Method: Single institution retrospective study of oncology patients with CVADs who received systemic treatment at the Walker Family Cancer Centre (WFCC) between 1 January and 31 December 2018. Results: A total of 480 CVADS were placed in 305 patients, of which 408 (85%) were peripherally inserted central catheters (PICCs) and 72 (15%) were implanted vascular access devices (PORTs). The incidence of early and late complications was 9% and 24%, respectively. For the entire cohort, the rate of venous thromboembolism (VTE) was 16%, of which 9% were CVAD-related thrombosis (CRTs) and 7% were distant VTE. The CRT rates were similar for PICCs and PORTs (9% vs. 7%). A total of 6% of CVADs were complicated by infection (i.e., localized infections and bacteremia), with a total infection rate of 0.43 and 0.26 per 1000 indwelling days for PICCs and PORTs, respectively. The incidence of central line associated bloodstream infections (CLABSI) was greater for PICCs than PORTs, at a rate of 0.22 compared with 0.08 per 1000 indwelling days, respectively. The premature catheter removal rate was 26% for PICCs and 18% for PORTs. PORTs required more additional hospital visits. Conclusions: PICCs were utilized more frequently than PORTs and had a higher rate of premature removal. The rates of VTE and CRT were similar for both CVAD types. PORTs had a lower rate of infection per 1000 indwelling days. However, the management of PORT related complications required more visits to the hospital and oncology clinic. 相似文献
3.
Gian Eugenio Tontini Guido Manfredi Stefania Orlando Helmut Neumann Maurizio Vecchi Elisabetta Buscarini Luca Elli 《Digestive endoscopy》2019,31(6):627-643
Over the last decade, impressive technological advances have occurred in ultrasonography and small‐bowel endoscopy. Nowadays, endoscopic ultrasonography is an essential diagnostic tool and a therapeutic weapon for pancreatobiliary disorders. Capsule endoscopy and device‐assisted enteroscopy have quickly become the reference standard for the diagnosis of small‐bowel luminal diseases, thereby leading to radical changes in diagnostic and therapeutic pathways. We herein provide an up‐to‐date overview of the latest advances in endoscopic ultrasonography and small‐bowel endoscopy, focusing on the emerging paradigms and technological innovations that might improve clinical practice in the near future. 相似文献
4.
5.
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
6.
IntroductionRates of aneurysm occlusion with the pipeline embolization device (PED) has varied widely in the literature from 55.7% to 93.3% at 6 months, which may reflect a difference in technique including sizing and number of devices used.Methods140 cases at our institution were retrospectively reviewed, and aneurysms treated with a single PED vs. multiple were compared.ResultsComplete aneurysm occlusion was achieved in 86.9% at 6 months, 91.8% at 1 year, and 97.6% at longest follow-up. Retreatment with an additional device was required in 7 (5.1%). Major and minor complication rate within 30 days was 1.4% and 5.0%, and at greater than 30 days was 0.8% and 3.1%.Patients treated with multiple PEDs had significantly higher rates of aneurysm occlusion at 6 months (92.9% vs. 75.6%, p = 0.017) and 12 months (98.4% vs. 81.1%, p = 0.014), with no difference in complications. The two groups were similar aside from a higher number of ophthalmic and paraophthalmic aneurysms treated with multiple PEDs (23.4% vs. 6.5%, p = 0.004; and 35.1% vs. 17.4%, p = 0.020), and more posterior communicating artery and recurrent aneurysms treated with a single PED (28.3% vs. 3.2%, p = 0.001; 23.9% vs. 8.5%, p = 0.031). The use of multiple PEDs was found to be an independent predictor of aneurysm occlusion in a multivariate analysis (p = 0.015).ConclusionsThe use of multiple PEDs for intracranial aneurysms leads to significantly higher occlusion rates without added morbidity. This benefit is particularly appropriate for ophthalmic segment aneurysms, while more distal segments with eloquent perforating branches should be managed with caution. 相似文献
7.
8.
Rotary ventricular assist devices (VADs) are less sensitive to preload than the healthy heart, resulting in inadequate flow regulation in response to changes in patient cardiac demand. Starling‐like physiological controllers (SLCs) have been developed to automatically regulate VAD flow based on ventricular preload. An SLC consists of a cardiac response curve (CRC) which imposes a nonlinear relationship between VAD flow and ventricular preload, and a venous return line (VRL) which determines the return path of the controller. This study investigates the importance of a physiological VRL in SLC of dual rotary blood pumps for biventricular support. Two experiments were conducted on a physical mock circulation loop (MCL); the first compared an SLC with an angled physiological VRL (SLC‐P) against an SLC with a vertical VRL (SLC‐V). The second experiment quantified the benefit of a dynamic VRL, represented by a series of specific VRLs, which could adapt to different circulatory states including changes in pulmonary (PVR) and systemic (SVR) vascular resistance versus a fixed physiological VRL which was calculated at rest. In both sets of experiments, the transient controller responses were evaluated through reductions in preload caused by the removal of fluid from the MCL. The SLC‐P produced no overshoot or oscillations following step changes in preload, whereas SLC‐V produced 0.4 L/min (12.5%) overshoot for both left and right VADs. Additionally, the SLC‐V had increased settling time and reduced controller stability as evidenced by transient controller oscillations. The transient results comparing the specific and standard VRLs demonstrated that specific VRL rise times were improved by between 1.2 and 4.7 s ( = 3.05 s), while specific VRL settling times were improved by between 2.8 and 16.1 seconds ( = 8.38 s) over the standard VRL. This suggests only a minor improvement in controller response time from a dynamic VRL compared to the fixed VRL. These results indicate that the use of a fixed physiologically representative VRL is adequate over a wide variety of physiological conditions. 相似文献
9.
10.