检索结果-南通市图书馆

Opportunistic Usage of Maritime VHF Band—deployment Challenges for a New Regulatory Framework

Wireless Engineering and Technology 2014年第1期5卷 1-10页

作者： Eduardo Bolas nuno borges de carvalho José Neto Vieira Paulo Mónica de Oliveira Instituto de Telecomunicacoes/deTI Universidade de AveiroAveiroPortugal Naval Research Centre(CINAV)-Escola Naval AlmadaPortugal Instituto de Engenharia Electrónica e Telematica de Aveiro/deTI Universidade de AveiroAveiroPortugal

Similarly to other domains, maritime community requests for broadband services have been significantly increasing. Worldwide navigation footprint and the lack of practical alternatives to Satellite Communications (SATCOM) empower VHF band as the natural choice to support most of those demands. Nevertheless, the major challenge for an implementation of maritime broadband VHF services is unquestionably the spectrum availability and management. Eventually, the solution must include spectrum sharing, using a Cognitive Radio (CR) based approach, but unfortunately current regulatory framework and spectrum management regime are not appropriate for such concepts and emerging technologies. To overcome such constraints, it is necessary to address a whole field of regulatory and standardization issues in order to prepare an evolution towards a more flexible and dynamic approach to spectrum management and a transition that would ensure incumbents live operations and legacy systems. The required paradigm change encompasses a new policy definition, an enforcement mechanism implementation and a comprehensive transition plan. The presented analysis pretends to address the regulatory feasibility of a framework change, discusses its evolving process and points some challenges related with practical aspects associated to Quality of Service (QoS) enforcement metrics definition, centering the arguments in maritime VHF band.

关键词： Maritime Communications Broadband VHF Cognitive Radio Regulatory Framework Dynamic Spectrum Access Metrics

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Multi-mechanical waves against Alzheimer’s disease pathology:a systematic review

引用

Translational Neurodegeneration 2021年第3期10卷 459-486页

作者： Francisca Monteiro Ioannis Sotiropoulos Óscar carvalho nuno Sousa Filipe S.Silva Center for Microelectromechanical Systems(CMEMS) University of MinhoCampus Azurém4800-058 GuimarãesPortugal Life and Health Sciences Research Institute(ICVS) Medical SchoolUniversity of MinhoCampus Gualtar4710-057 BragaPortugal ICVS/3B’s-PT Government Associate Laboratory Braga/GuimarãesPortugal Institute of Biosciences&Applications NCSR“demokritos” AthensGreece

Alzheimer’s disease(AD)is the most common cause of dementia,afecting approximately 40 million people *** inefectiveness of the available pharmacological treatments against AD has fostered researchers to focus on alternative strategies to overcome this *** vibrations delivered in diferent stimulation modes have been associated with marked improvements in cognitive and physical performance in both demented and nondemented *** of the mechanical-based stimulation modalities in eforts are earlier whole-body vibration,transcranial ultrasound stimulation with microbubble injection,and more recently,auditory ***,there is a huge variety of treatment specifcations,and in many cases,conficting results are *** this review,a search on Scopus,PubMed,and Web of Science databases was performed,resulting in 37 *** studies suggest that mechanical vibrations delivered through diferent stimulation modes are efective in attenuating many parameters of AD pathology including functional connectivity and neuronal circuit integrity defcits in the brains of AD patients,as well as in subjects with cognitive decline and non-demented older *** the evolving preclinical and clinical evidence on these therapeutic modalities,their translation into clinical practice is not consolidated ***,this comprehensive and critical systematic review aims to address the most important gaps in the reviewed protocols and propose optimal regimens for future clinical application.

关键词： Alzheimer’s disease Auditory stimulation Mechanical vibrations Ultrasounds Whole-body vibration

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

An Overview of SWIPT Circuits and Systems

引用

ZTE Communications 2022年第2期20卷 13-18页

作者： Ricardo TORRES Diogo MATOS Felisberto PEREIRA Ricardo CORREIA nuno borges carvalho department of Electronics telecommunications and informationUniversity of AveiroAveiro 3810Portugal Institute of Telecommunications Aveiro 3800Portugal CISeD-Research Center in Digital Services Polytechnic of ViseuViseu 3500Portugal Sinuta SA. Estarreja 3860Portugal AlmaScience Colab Madan ParqueCaparica 2829-516Portugal

From a circuit implementation perspective,this paper presents a brief overview of simultaneous wireless information and power transmission(SWIPT).By using zero-power batteryless wireless sensors,SWIPT mixes wireless power transmission with wireless communications to allow the truly practical implementation of the Internet of Things as well as many other *** this paper,technical backgrounds,problem formation,state-of-the-art solutions,circuit implementation examples,and system integrations of SWIPT are presented.

关键词： simultaneous wireless information and power transmission(SWIPT)systems backscatter communication low power commu⁃nication

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Anal canal gastrointestinal stromal tumors:Case report and literature review

引用

World Journal of Gastroenterology 2014年第1期20卷 319-322页

作者： nuno carvalho Diogo Albergaria Rui Lebre Joo Giria Vitor Fernandes Helena Vidal Maria José Brito department of General Surgery Garcia de Orta Hospital2801-951 AlmadaPortugal department of Gastroenterology Garcia de Orta Hospital2801-951 AlmadaPortugal department of Radiology Garcia de Orta Hospital2801-951 AlmadaPortugal department of Pathology Garcia de Orta Hospital2801-951 AlmadaPortugal

Gastrointestinal stromal tumors (GIST) are an uncommon group of tumors of mesenchymal origin. GIST of the anal canal is extremely rare. At present, only 10 cases of c-kit positive anal GIST have been reported in the literature. There is no widely accepted treatment approach for this neoplasia. Literature is sparse on imaging evaluation of anal canal GIST, usually described as a lesion in the intersphincteric space. We describe the case of a 73-year-old man with a mass in the anal canal, and no other symptoms. Endoanal ultrasound and magnetic resonance imaging showed a well circumscribed solid nodule in the intersphincteric space. The patient was treated by local excision. Gross pathological examination showed a 7 cm × 3.5 cm × 3 cm mass, and histological examination showed a proliferation of spindle cells, with prominent nuclear palisading. The mitotic count was of 12 mitoses/50 HPF. The tumor was positive for KIT protein, CD34 and vimentin in the majority of cells, and negative for desmin and S100. A diagnosis of GIST, with high risk aggressive behavior was made. An abdomino-perineal resection was discussed, but refused. The follow-up included clinical evaluation and anal ultrasound. After 5 years the patient is well, with maintained continence and no evidence of local recurrence.

关键词： Gastrointestinal stromal tumors Anal canal Endoanal ultrasound Magnetic resonance imaging C-Kit receptor Local excision

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Lymphocyte subsets in alcoholic liver disease

引用

World Journal of Hepatology 2013年第2期5卷 46-55页

作者： Luís Costa Matos Paulo Batista nuno Monteiro Joo Ribeiro Maria A Cipriano Pedro Henriques Fernando Giro Armando carvalho Faculty of Medicine of the University of Coimbra 3004-504 CoimbraPortugal Centro Hospitalar Tondela Viseu E.P.E3504-509 ViseuPortugal department of Anatomopathology University of Coimbra Hospital3004-504 CoimbraPortugal

AIM:To compare lymphocyte subsets between healthy controls and alcoholics with liver ***:The patient cohort for this study included individuals who were suspected to have alcoholic liver disease(ALD) and who had undergone liver biopsy(for disease grading and staging,doubts about diagnosis,or concurrent liver disease;n = 56).Normal controls included patients who were admitted for elective cholecystectomy due to non-complicated gallstones(n = 27).Formalin-fixed,paraffin-embedded liver biopsy specimens were sectioned and stained with hematoxylin and eosin and Perls' Prussian *** non-alcoholic steatohepatitis score was used to assess markers of *** population subsets were determined by flow cytometry.T lymphocytes were identified(CD3+),and then further subdivided into CD4+ or CD8+ populations.B lymphocytes(CD19+) and natural killer(NK) cell numbers were also *** addition to assessing lymphocyte subpopulation differences between ALD patients and controls,we also compared subsets of alcoholic patients without cirrhosis or abstinent cirrhotic patients to normal ***:The patient cohort primarily consisted of older *** alcoholism was present in 66.1%.Reported average daily alcohol intake was 164.9 g and the average lifetime cumulative intake was 2211.6 *** was present in 39.3% of the patients and 66.1% had significant fibrosis(perisinusoidal and portal/periportal fibrosis,bridging fibrosis,or cirrhosis) in their liver *** average Mayo end-stage liver disease score was *** hereditary hemochromatosis genotypes were *** patients(n = 56) presented with significant lymphopenia(1.5 × 109/L ± 0.5 × 109/L vs 2.1 × 109/L ± 0.5 × 109/L,P decrease in all lymphocyte subpopulations,except for NK lymphocytes:CD3+(1013.0 ± 406.2/mm3 vs 1523.0 ± 364.6/mm3,P < 0.0001),CD4+(713.5 ± 284.7/mm3 vs 992.4 ± 274.7/mm3,P < 0.0001),CD8+(262.3 ± 140.4/mm3 vs 478.9 ± 164.6/mm3,P < 0.0001),and CD19+(120.6

关键词： Lymphocyte subsets Flow cytometry Alcoholism Alcoholic liver disease Liver fibrosis Liver biopsy HFE gene

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effects of Five Years Adoption of No-Tillage Systems for Vegetables Crops in Soil Organic Matter Contents

引用

Agricultural Sciences 2018年第1期9卷 117-128页

作者： Carlos E. P. Lima ítalo M. R. Guedes Juscimar da Silva Flávia A. Alcantara nuno R. Madeira Agnaldo D. F. carvalho Mariana R. Fontenelle Embrapa Hortaliç as CNPH Brasília Brazil

Vegetables productions systems are done normally with intense soil tillage causing a strong decline of soil quality. Use of conservation systems can be an alternative to recover this quality. In order to evaluate the effects of such systems on soil organic matter, an experiment has been conducted in randomized blocks design and factorial scheme 3 × 2: three soil management systems (no-tillage;reduced tillage and conventional tillage) and two cover crops (maize single;and intercropping maize with gray velvet bean—Stizolobium niveum);and repeated measures over time. Soil samples were collected before the implementation of the experiment and at the end of each crop cycle until the fifth crop cycle. Carbon associated with humic substances is also determined in 0 - 5 cm, 5 - 10 cm and 10 - 30 cm at the end of the last crop cycle. The SOM content was higher in RT (48.34 g·kg-1) than in the CT (39.48 g·kg-1) at the end of the fifth crop cycle. SOM content in NT (44.92 g·kg-1) was statistically equal to RT and CT, during the same period. In 0 - 5 cm, carbon contents associated to the humic substances present the same behavior of SOM contents in 0 - 10 cm. Probably these results are associated with the capacity of each system to improve superficial contents of SOM stable fractions. It follows that the conservation systems used are alternatives to the cultivation vegetables in order to improve soil organic matter contents.

关键词： No-Tillage Reduced Tillage Soil Conservation Soil Management

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

“小动作”改变街区面貌

引用

设计家 2010年第2期 86-93页

作者： Tiago Mota Saraiva nuno carvalho Andreia Salavessa Raquel Capelo with Carolina Condeo nuno Ferreira Vera Joo Joo Ribeiro Joo Ferro with Sónia Oliveira Joao Morgado Ateliermob

Sacavém是位于里斯本的市郊的一个传统小城镇,以发展陶器工业为主。传统工业的逐渐消失和快速增长的居民人数,使得它渐渐失去了原有的城市脉络,大量毫无特色的普通住宅,更使它如今看起来就像是一座"宿舍城"。上个世纪末。

关键词：里斯本传统小城镇城市规划传统工业普通住宅干预方式市政厅快速增长咖啡建筑师

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：