全文获取类型
收费全文 | 157篇 |
免费 | 9篇 |
国内免费 | 1篇 |
专业分类
儿科学 | 3篇 |
妇产科学 | 2篇 |
基础医学 | 12篇 |
口腔科学 | 1篇 |
临床医学 | 5篇 |
内科学 | 37篇 |
皮肤病学 | 12篇 |
神经病学 | 6篇 |
特种医学 | 3篇 |
外科学 | 34篇 |
综合类 | 1篇 |
预防医学 | 15篇 |
眼科学 | 16篇 |
药学 | 6篇 |
肿瘤学 | 14篇 |
出版年
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 10篇 |
2013年 | 10篇 |
2012年 | 7篇 |
2011年 | 18篇 |
2010年 | 10篇 |
2009年 | 3篇 |
2008年 | 6篇 |
2007年 | 9篇 |
2006年 | 4篇 |
2005年 | 8篇 |
2004年 | 9篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2000年 | 1篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1979年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有167条查询结果,搜索用时 78 毫秒
1.
2.
3.
ObjectivesThe aim of this paper is to illustrate the current status of imaging in high breast density as we enter a new decade of advancing medicine and technology to diagnose breast lesions.Key findingsEarly detection of breast cancer has become the chief focus of research from governments to individuals. However, with varying breast densities across the globe, the explosion of breast density information related to imaging, phenotypes, diet, computer aided diagnosis and artificial intelligence has witnessed a dramatic shift in new screening recommendations in mammography, physical examination, screening younger women and women with comorbid conditions, screening women at high risk, and new screening technologies. Breast density is well known to be a risk factor in patients with suspected/known breast neoplasia. Extensive research in the field of qualitative and quantitative analysis on different tissue characteristics of the breast has rapidly become the chief focus of breast imaging. A summary of the available guidelines and modalities of breast imaging, as well as new emerging techniques under study that can potentially provide an augmentation or even a replacement of those currently available.ConclusionDespite all the advances in technology and all the research directed towards breast cancer, detection of breast cancer in dense breasts remains a dilemma.Implications for practiceIt is of utmost importance to develop highly sensitive screening modalities for early detection of breast cancer. 相似文献
4.
Murad Aljiffry Mawaddah Alrajraji Salman Al-Sabah Mazen Hassanain 《Saudi Journal Of Gastroenterology》2014,20(5):315-318
Laparoscopic approaches have been increasingly used in selected patients with either colorectal or liver cancer. However, simultaneous resection of colorectal carcinoma with synchronous liver metastases is still a subject of debate. The present case describes combined laparoscopic rectal and liver resections for a patient with primary rectal cancer and a synchronous liver metastasis utilizing a Pfannenstiel incision for specimen extraction. The operative time was 370 min and estimated blood loss was 400 mL. Postoperatively, the patient required parenteral analgesia for 48 h, resumed normal diet on day 3 and was discharged on day 7 after the operation. A laparoscopic approach utilizing a Pfannenstiel extraction incision may present an advantageous and attractive option for simultaneous laparoscopic rectal and liver resection in selected patients with the aim of improving short-term outcomes. 相似文献
5.
Hamza Shaili Elmehdi Salmani Mustapha Beraich M'hamed Taibi Mustapha Rouchdi Hamid Ez-Zahraouy Najem Hassanain Ahmed Mzerd 《RSC advances》2021,11(59):37019
The inorganic stannous-based perovskite oxide SrSnO3 has been utilized in various optoelectronic applications. Facilitating the synthesis process and engineering its properties, however, are still considered challenging due to several aspects. This paper reports on a thorough investigation of the influence of rare-earth (praseodymium) doping on the microstructural and optoelectronic properties of pure and Pr-doped SrSnO3 perovskite oxide thin films synthesized by a two-step simple chemical solution deposition route. Structural analysis indicated the high quality of the obtained phase and the alteration generated from the insertion of impurities. Surface scanning illustrated the formation of homogenous and crack-free SrSnO3 thin films with a nanorod morphology, with an augmentation in size as the dopant ratios increased. Optical properties analysis showed an enhancement in the samples optical absorption with wide-range bandgap tuning. First-principles calculations revealed the exchange interactions between the 3d–4f states and their impact on the electronic properties of the pristine material. Hall-effect measurements revealed an immense decrement in the resistivity of the films upon increment of doping ratios, passing from 7.3 × 10−2 Ω cm for the undoped sample to 4.8 × 10−2 Ω cm for 7% Pr content, while a reverse trend was observed on the carrier mobility, rising from 2.5 to 7.6 cm2 V−1 s−1 for 7% Pr content. The results emphasized the efficiency of the simple synthesis route to produce high-quality samples. The current findings will contribute to paving the way towards expanding the utilization of simple and cost-effective chemical solution deposition methods for the fast and large area growth of stannous-based perovskite oxides for optoelectronic applications.Unraveling the optical, electronic and electrical properties of high-quality nanorod morphology spray-coated Pr-doped SrSnO3 perovskite oxide thin films. 相似文献
6.
Hamza Shaili Elmehdi Salmani Mustapha Beraich Abderrahim Elhat Mustapha Rouchdi Mhamed Taibi Hamid Ez-Zahraouy Najem Hassanain Ahmed Mzerd 《RSC advances》2021,11(41):25686
Delafossite materials are considered to be a promising range of transparent conductive oxides for optoelectronic applications. The complications that have held back their implementation in practical devices lie in the complex growth methods that are required and in the formation of undesirable secondary phases. Herein, a fast, simple, and low-cost deposition method allowing the deposition of high-quality 2H-CuFeO2 nanostructured thin films is employed. The effect of Sr doping on the properties of spray-coated CuFeO2 thin film annealed at 850 °C is reported. X-ray diffraction (XRD) analysis revealed the delafossite structures of all the samples corresponding to the 2H-CuFeO2 phase. The lattice spacing decreased with increasing substitution of Sr at the Cu site. Raman analysis further authenticated the structural results collected via XRD analysis. Surface scanning using field-emission scanning electron microscopy revealed the formation of nanostructured CuFeO2 thin film possessing high crystalline quality, with the nanocrystal size increasing as the dopant content was increased. Energy-dispersive X-ray analysis allowed the quantification of the elements content via determining the ratios of the main elements as well as the dopant content in each sample. The optical properties of the samples showed strong light absorption in the visible region with a decrease in the band gap values with Sr insertion. First-principles calculations using density functional theory (DFT) were conducted to strengthen the experimental findings regarding the nature of the bonds in the hexagonal lattice of the CuFeO2 compound and the effect of Sr doping on its characteristics. The electrical properties measured at room temperature revealed p-type conductivity with tunable resistivity, while the samples displayed increased electron mobility as a function of the dopant content. Consequently, our work introduced an efficient and cost-effective synthesis route for the preparation of high-quality nanostructured 2H-CuFeO2 thin films, paving the way to facilitate further device applications.Facile synthesis of the challenging 2H-CuFeO2 delafossite nanostructured thin films is reported, and the effect of Sr doping is revealed experimentally and theoretically. 相似文献
7.
Cantin B Giannetti N Parekh H Panchal SN Kwok BW Najem R Woodman K Hunt SA Valantine HA 《Clinical transplantation》2002,16(3):196-201
BACKGROUND: When used in conjunction with steroids and cyclosporin, mycophenolate mofetil (MMF) has been shown to significantly reduce mortality and incidence of rejection in the first year after heart transplantation. It also appears that in this early post-transplantation period, the monitoring of immunosuppressive therapies may be warranted. The current study was undertaken to determine if such monitoring is still useful more than 1 yr after heart transplantation. METHODS: Twenty-six patients who had survived the first year after orthotopic heart transplantation and had been on MMF therapy for more than 3 months were prospectively followed. At the time of their routine endomyocardial biopsy blood samples were taken to monitor immunosuppressive therapy. Most patients had two samples taken, on average 109 d apart. RESULTS: There were 22 episodes of asymptomatic rejection documented on a total of 48 biopsies. Of these, only two were of ISHLT (International Society for Heart and Lung Transplantation) grade 3A the remainder being of ISHLT grades 1 or 2. There was no relation between immunosuppressive regimen (tacrolimus and MMF or cyclosporin and MMF) and rejection. There was no relation between monitored immunosuppressive levels and rejection. Patients with the combination of MMF and tacrolimus had significantly higher plasma mycophenolic acid levels despite significantly lower daily MMF dose. CONCLUSION: There does not appear to be a benefit in continued monitoring of plasma mycophenolic acid levels beyond the first year of heart transplantation. There were significant differences in plasma mycophenolic acid levels depending on the type of calcineurin inhibitor concomitantly used. 相似文献
8.
Hassanain HH Irshaid F Wisel S Sheridan J Michler RE Goldschmidt-Clermont PJ 《Surgery》2005,137(1):92-101
BACKGROUND: Hyperoxia has been shown to improve wound healing; however, the mechanism for such therapeutic effects of oxygen remains hypothetical. Rac 1 regulates a wide variety of cellular activities, including cell proliferation and migration, and also is a key regulator for the activity of the nicotinamide dinucleotide phosphate oxidase the enzyme complex responsible for the production of a large fraction of cellular superoxide. METHODS: We generated transgenic mice that express either the cDNA of a constitutively active mutant of human Rac 1 (V12 mutant or Rac CA) or the dominant negative isoform (V12 and N17 mutant or Rac DN) in the blood vessels using mouse vascular smooth muscle promoter for alpha-actin. We placed 2 wounds of 6 mm in diameter at the middorsal region of each mouse and allowed about 3 weeks for the wounds to heal. RESULTS: The size of the wounds in Rac CA transgenic mice was reduced relative to wild type mice; healing of Rac DN mice was slower than wild type and Rac CA ( P < .05). Blood vessel formation appeared faster in Rac CA mice, a finding associated with enhanced expression of some angiogenic growth factors. CONCLUSION: The current studies suggest that Rac 1 activation accelerates the wound healing process and is associated with more efficient angiogenesis at the wound site. 相似文献
9.
This paper describes a unique fracture pattern of the proximal phalanx in children that has not been specifically studied in the literature. Volarly, the fracture line passes through the phalangeal neck and then the fracture line passes dorsally to include a dorsal flange of the metaphysis. Fractures were classified into three types: type I fractures were undisplaced with no finger deformity; type II fractures were mildly displaced in the antero-posterior plane without lateral angulation or scissoring; while type III fractures were severely displaced or had associated lateral angulation or scissoring deformity. Over a 6-year-period, nine cases were seen by the authors. The mechanism of injury was by entrapping the digit in a closing door in all cases. The mean age of patients was 5 years. Types I and II fractures were seen in five children and all were treated by splinting with an excellent outcome. Two children with type III fractures were treated with closed reduction and either splinting (one case) or k-wire (one case), and both had a poor initial outcome. The remaining two children with type III fractures were treated with open reduction and internal fixation with an excellent outcome. Differences between these fractures and the classic phalangeal neck fractures are discussed. 相似文献
10.
Recent directives from the American Board of Surgery requires that applicants become familiar with a variety of endoscopic procedures. The purpose of this report is to review the VA Medical Center's two and a half year experience following the establishment of a surgical endoscopy unit. During the first year, July 1982-June 1983, 212 procedures were performed. These included 64 Colonoscopies (C), 98 Gastroscopies (G), 42 Flexible Sigmoidoscopies (S) and 8 Choledochoscopies (CD). The following year 564 procedures were performed (C-201, G-269, S-86, CD-8). Over the last 6 months 210 procedures were performed (C-98, G-86, S-22, CD-4). Senior surgical residents in their fourth or fifth year of training spent 4 months in the endoscopy service as part of their surgical oncology rotation. Technical and diagnostic competency was achieved in 2 to 4 months. This review indicates that the volume of cases, currently averaging 45 per month, is adequate to train surgical residents and support an independent endoscopy service. The establishment of the unit has also been associated with the development of screening programs for colon and esophageal cancers as well as broader applications of some of the newer indications of fiberoptic endoscopy. Future plans include introduction of variceal sclerotherapy and ERCP. 相似文献