检索结果-南通市图书馆

Acetosolv delignification of marabou (Dichrostachys cinerea) wood with and without acid prehydrolysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Forestry Studies in China 2011年第1期13卷 64-70页

作者： Venkata Prabhakar SOUDHAM Dani RODRIGUEZ george j.M ROCHA Mohammad j.TAHERZADEH Carlos MARTIN Bioresource Technology Group Department of Chemistry and Chemical EngineeringUniversity of Matanzas School of Engineering University of Bors Department of Biotechnology Lorena School of EngineeringUniversity of So Paulo

The chemical composition of marabou（Dichrostachys cinerea） wood and its treatment with acetic acid were *** different treatment approaches,direct acetosolv and combined acid prehydrolysis/acetosolv,were *** effects of acetic acid concentration（50%,70% and 90%） and temperature（normal boiling temperature and 121°C） on yield of solids,solubilization of lignin and hemicelluloses and recovery of cellulose were evaluated for both *** solubilization of marabou components was observed in the direct acetosolv treatment at 121°C,especially at the highest acetic acid concentration,where around 84.8% of lignin and 78% of hemicelluloses were *** the material was subj.cted to acid prehydrolysis prior to acetosolv treatment,lignin solubilization was improved,especially at low acetic acid *** 80% of the solubilized lignin was recovered from the liquors in the direct acetosolv treatment,but the recovery was lower in the combined *** was well preserved in all the treatment schemes.

关键词： Dichrostachys cinerea delignification acetosolv acid hydrolysis

Road induced edge effects on a forest bird community in tropical Asia

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

Avian Research 2018年第2期9卷 123-135页

作者： Daphawan Khamcha Richard T.Corlett Larkin A.Powell Tommaso Savini Antony j.Lynam george A.Gale Conservation Ecology Program School of Bioresources and Technology King Mongkut’s University of Technology Thonburi Center for Integrative Conservation Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences School of Natural Resources University of Nebraska-Lincoln Wildlife Conservation Society Global Conservation Program

Background: Edge effects cause changes in bird community richness, abundance, and/or distribution within a landscape, but the avian guilds most influenced can vary among regions. Although Southeast Asia has the highest rates of deforestation and proj.cted species loss, and is currently undergoing an explosive growth in road infrastructure, there have been few studies of the effects of forest edges on avian communities in this ***: We examined avian community structure in a dry evergreen forest in northeastern Thailand adj.cent to a five-lane highway. We evaluated the richness and abundance of birds in 11 guilds at 24 survey points on three parallel transects perpendicular to the edge. At each point, 10-min surveys were conducted during February-August 2014 and March-August 2015. Vegetation measurements were conducted at 16 of the bird survey points and ambient noise was measured at all 24 survey ***: We found a strongly negative response to the forest edge for bark-gleaning, sallying, terrestrial, and understory insectivores and a weakly negative response for arboreal frugivore-insectivores, foliage gleaning insectivores, and raptors. Densities of trees and the percentage canopy cover were higher in the interior, and the ambient noise was lower. In contrast, arboreal nectarivore-insectivores responded positively to the forest edge, where there was a higher vegetation cover in the ground layer, a lower tree density, and a higher level of ambient ***: Planners should avoid road development in forests of high conservation value to reduce impacts on biodiversity. Where avoidance is impossible, a number of potential mitigation methods are available, but more detailed assessments of these are needed before they are applied in this region.

关键词： Road edge Avian guilds Dry evergreen forest Thailand

Acute upper gastrointestinal bleeding in octοgenarians:Clinical outcome and factors related to mortality

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

World j.urnal of Gastroenterology 2008年第25期14卷 4047-4053页

作者： george j.Theocharis Vassiliki Arvaniti Stelios F Assimakopoulos Konstantinos C Thomopoulos Vassilis Xourgias Irini Mylonakou Vassiliki N Nikolopoulou Division of Gastroenterology Department of Internal Medicine University Hospital of Patras Department of Gastroenterology "Tzaneio" General Hospital Department of Internal MedicineUniversity Hospital of Patras

AIM: To evaluate the aetiology, clinical outcome and factors related to mortality of acute upper gastrointestinal bleeding (AUGIB) in octogenarians. METHODS: We reviewed the records of all patients over 65 years old who were hospitalised with AUGIB in two hospitals from j.nuary 2006 to December of 2006. Patients were divided into two groups: Group A (65-80 years old) and Group B (> 80 years old). RESULTS: Four hundred and sixteen patients over 65 years of age were hospitalized because of AUGIB. Group A included 269 patients and Group B 147 patients. Co-morbidity was more common in octogenarians (P = 0.04). The main cause of bleeding was peptic ulcer in both groups. Rebleeding and emergency surgery were uncommon in octogenarians and not different from those in younger patients. In-hospital complications were more common in octogenarians (P = 0.05) and more patients died in the group of octogenarians compared to the younger age group (P = 0.02). Inability to perform endoscopic examination (P = 0.002), presence of high risk for rebleeding stigmata (P = 0.004), urea on admission (P = 0.036), rebleeding (P = 0.004) and presenceof severe co-morbidity (P < 0.0001) were related to mortality. In multivariate analysis, only the presence of severe co-morbidity was independently related to mortality (P = 0.032). CONCLUSION: While rebleeding and emergency surgery rates are relatively low in octogenarians with AUGIB, the presence of severe co-morbidity is the main factor of adverse outcome.

关键词： Acute upper gastrointestinal bleeding Octogenarians Elderly Co-morbidity Mortality

Room Temperature Sol-Gel Fabrication and Functionalization for Sensor Applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonic Sensors 2013年第2期3卷 168-177页

作者： george HUYANG j.hn CANNING Ingemar PETERMANN David BISHOP Andrew McDONAGH Maxwell j. CROSSLEY School of Chemistry The University of Sydney NSW 2006 Australia Interdisciplinary Photonic Laboratories (iPL) School of Chemistry 222 Madsen Building F09 The University of Sydney NSW 2006 Australia University of Technology Sydney Broadway NSW 200 7 Australia

The structure and physical properties of a thin titania sol-gel layer prepared on silicon and silica surfaces were examined. Spectroscopic （FTIR, UV-VIS spectroscopy）, refractive index （ellipsometry） and microscopic （light microscopy and SEM/EDS） tools were used to examine both chemical uniformity and physical uniformity of the sol-gel glass layers. The conditions for the fabrication of uniform layers were established, and room temperature dopant incorporation was examined. The absorption bands of porphyrin-containing titania sol-gel layers were characterized. By addition of a metal salt to the titania layer, it was possible to metallate the free-base porphyrin within and change the UV-VIS absorbance of the porphyrin, the basis of metal detection using porphyrins. The metalloporphyrins were detected by localized laser ablation inductive coupled mass spectroscopy （LA-ICP-MS）, indicating fairly uniform distribution of metals across the titania surface.

关键词： Sol-gel titania titanium dioxide evanescent field sensor organic compound spectroscopy microscopy surface functionalization ablation inductive coupled mass spectroscopy

Development of a Comprehensive Pavement Management Information Systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Development of a Comprehensive Pavement Management Informati...

Virtual endoscopy of the urinary tract

4～(th) International Conference on Road & Airfield Pavement Technology

作者： Eddie Y.j.Chou george j. Murnen Department f Civil Engineering The University of Toledo Toledo Ohio 43606 Department f Civil Engineering The University of Toledo Toledo Ohio 43606

＜正＞ This paper describes the development of a comprehensive pavement management information （PMIS） system for the city of Toledo, Ohio, U.S.A. The city has a paved street network of approximately 1, 100 miles, of which about 360 miles are considered maj.r roads with a traffic volume of greater than600 per day. The rest are considered as secondary and residential streets. Instead of using off-the- shelf commercial software or hiring out the work to an outside contractor, the City and the University of Toledo developed a partnership to design and implement a PMIS that uses the state-of-the-art technologies and responses to the specific needs of the city. The PMIS uses a geographic information system （GIS）-ArcView by ESRI-as its presentation module and includes a number of other modules. Data base module stores pavement inventory and condition data in a custom-designed Microsoft Access database, which facilitates data input and update. The maj.r streets are dynamically segmented while the residential streets are management by pavement sections between two intersections. Current condition data are collected using a van equipped with laser profiler （for measuring ride quality） and digital camera （for surveying surface distresses）. Most of the data processing tasks have been automated, so the chance for operator induced error has been minimized. At the heart of the PMIS is a module that predicts pavement performance based on past and current conditions, expected traffic loading, pavement structure, materials, and climatic environment. This pavement performance prediction module is crucial in supporting the PMIS to provide a multiyear work plan. Since the City had had little record regarding its pavement performance prior to this proj.ct, a condition prediction model were assumed initially and updated as actual data are accumulated. A multiyear optimization module then uses current and predicted conditions, specific distresses and likely treatments, traffic volume, availab

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Asian j.urnal of Andrology 2006年第1期8卷 31-38页

作者： george C.Kagadis Dimitrios Siablis Evangelos N.Liatsikos Theodore Petsas george C. Nikiforidis Department of Medical Physics Department of Radiology Department of Urology School of MedicineUniversity of PatrasGR 26500 RionGreece Department of Radiology Department of Medical Physics

Technological breakthroughs have advanced the temporal and spatial resolutions of diagnostic imaging, and 3 dimensional （3-D） reconstruction techniques have been introduced into everyday clinical practice. Virtual endoscopy （VE） is a non-invasive technique that amplifies the perception of cross-sectional images in the 3-D space, providing precise spatial relationships of pathological regions and their surrounding structures. A variety of computer algorithms can be used to generate 3-D images, taking advantage of the information inherent in either spiral computed tomography or magnetic resonance imaging （MRI）. VE images enable endoluminal navigation through hollow organs, thus simulating conventional endoscopy. Several clinical studies have validated the diagnostic utility of virtual cystoscopy, which has high sensitivity and specificity rates in the detection of bladder tumor. Published experience in the virtual exploration of the renal pelvis, ureter and urethra is encouraging but still scarce. VE is a safe, non-invasive method that could be applied in the long-term follow-up of patients with ureteropelvic j.nction obstruction, urinary bladder tumors and ureteral and/or urethral strictures. Its principal limitations are the inability to provide biopsy tissue specimens for histopathologic examination and the associated ionizing radiation hazards （unless MR/is used）. However, in the case of endoluminal stenosis or obstruction, VE permits virtual endoluminal navigation both cephalad and caudal to the stenotic segment. To conclude, VE provides a less invasive method of evaluating the urinary tract, especially for clinicians who are less familiar with cross-sectional imaging than radiologists. （Asian j.Androl 2006 j.n; 8： 31-38）

关键词： computed tomography three-dimensional imaging virtual endoscopy urethral stricture

Efficient and Accurate Numerical Methods Using the Accelerated Spectral Deferred Correction for Solving Fractional Differential Equations

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

Numerical Mathematics(Theory,Methods and Applications) 2022年第4期15卷 876-902页

作者： Xuej.an Chen Zhiping Mao george Em Karniadakis School of Science Jimei UniversityXiamen 361021China School of Mathematical Sciences Fujian Provincial Key Laboratory of Mathematical Modeling and High-Performance Scientific ComputingXiamen UniversityXiamenChina Division of Applied Mathematics Brown UniversityProvidenceRI 02912USA

We develop an efficient and accurate spectral deferred correction(SDC)method for fractional differential equations(FDEs)by extending the algorithm in[14]for classical ordinary differential equations(ODEs).Specifically,we discretize the resulted Picard integral equation by the SDC method and accelerate the convergence of the SDC iteration by using the generalized minimal residual algorithm(GMRES).We first derive the correction matrix of the SDC method for FDEs and analyze the convergence region of the SDC *** then present several numerical examples for stiff and non-stiff FDEs including fractional linear and nonlinear ODEs as well as fractional phase field models,demonstrating that the accelerated SDC method is much more efficient than the original SDC method,especially for stiff ***,we resolve the issue of low accuracy arising from the singularity of the solutions by using a geometric mesh,leading to highly accurate solutions compared to uniform mesh solutions at almost the same computational ***,for long-time integration of FDEs,using the geometric mesh leads to great computational savings as the total number of degrees of freedom required is relatively small.

关键词： Stiff problem generalized minimal residual geometric mesh refinement long time evolution fractional phase field models

Implementing the GEOSS water strategy: from observations to decisions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International j.urnal of Digital Earth 2023年第1期16卷 1439-1468页

作者： Richard Lawford Sushel Unninayar george j.Huffman Wolfgang Grabs Angélica Gutiérrez Chu Ishida-Watanabe Toshio Koike Morgan State University BaltimoreUSA NASA Goddard Space Flight Center GreenbeltUSA International Water Affairs Federal Institute of HydrologyKoblenz National Oceanic and Atmospheric Administration Silver SpringUSA j.pan Aerospace Exploration Agency Tsukuba International Centre for Water Hazard and Risk Management Tsukuba

In 2014,The GEOSS Water Strategy–From Observations to Decisions was published and steps were taken to implement the Strategy’s *** Strategy highlighted priority areas where the application of Earth observations to water research and water management decisions would have significant scientific and societal *** article reviews the implementation of the Strategy’s recommendations over the past eight *** a review of the Strategy’s assessment of the needs for water observations and their applications,it then reviews actions taken in response to the Strategy’s recommendations in its four maj.r themes:improved data acquisition for Essential Water Variables,research and product development,interoperability,and capacity *** highlights significant achievements in the implementation of the Strategy including some motivated by factors beyond this Strategy,reviews actions taken by participating agencies and programs for each of the main themes and summarizes the remaining challenges in achieving the Strategy’s full *** article not only is an update for the Water Community regarding the GEOSS Water Strategy,but it is also an example of how other communities could develop and promulgate a set of strategic recommendations,monitor progress,and carry out assessments of their effectiveness.

关键词： Earth observations water essential water variables research interoperability capacity development

Leptin rescues neurons from Alzheimer’s disease-related pathways triggered by lipid burden

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Alzheimer's Disease 2013年第1期2卷 31-39页

作者： Steven j. Greco george Perry j. Wesson Ashford Ashkan Hamzelou j.ne M. j.hnston Nikolaos Tezapsidis Neurotez Inc. Bridgewater USA Stanford/VA Medical Center Palo Alto USA University of Texas San Antonio USA

Adipocyte-derived leptin is a pleiotropic hormone implicated in control of lipid storage and mobilization, bone homeostasis, immune function and neuronal plasticity. Leptin has been shown to prevent accumulation of extracellular Aβ and hyperphosphorylation of tau in both cell culture and animal models. Herein an investigation was undertaken to test leptin’s ability to prevent the exacerbation/activation of AD-related pathways in neurons following their exposure to a high concentration of a variety of lipids. Specifically, cholesterol, oleic acid and/or ceramide were added to the media of cells resulting in decreased cellular viability and energy metabolism, and in increased tau phosphorylation and extracellular Aβ. Leptin increased viability, boosted cellular metabolism by activating AMP-activated protein kinase (AMPK) and the sirtuins (SIRT) and reduced tau phosphorylation and Aβ accumulation in a dose-dependent manner in response to select challenges. These findings demonstrate that leptin can attenuate the harmful effect of certain lipids that lead to exacerbation or activation of AD pathways. The study herein also provides the basis for a novel screening platform to define and identify a novel class of “metabolic” compounds addressing Alzheimer’s disease, based on a biological profile similar to leptin.

关键词： Leptin Cholesterol Ceramide AMPK SIRT Alzheimer’s Tau Amyloid-β