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排序方式: 共有458条查询结果,搜索用时 15 毫秒
71.
72.
Catanozi S Rocha JC Passarelli M Mesquita CH Suguiama VY Guzzo ML dos Santos Filho A Quintão EC Nakandakare ER 《Lipids》2006,41(7):663-668
Dyslipoproteinemia of the Nagase analbuminemic rat (NAR) is characterized by elevated concentrations of VLDL and LDL attributed
to increased rates of liver lipoprotein synthesis. Increased lysophosphatidylcholine (LPC) in NAR HDL has been attributed
to high plasma LCAT activity. We show here that, as compared with Sprague-Dawley rats (SDR), NAR plasma triacylglycerol (TAG),
total cholesterol (TC), HDL TAG, protein, total phospholipids (PL), LPC, and PS are increased. These alterations rendered
the NAR HDL particle more susceptible to the activity of the enzyme hepatic lipoprotein lipase (HL), which otherwise was unaltered
in our study. Fractional catabolic rates in blood of the autologous 125I-apoHDL (median and lower quartile values), were, respectively, 0.231 and 1.645 (n=10) in NAR as compared with 0.140 and 0.109 (n=10) in SDR (P=0.012), corresponding to synthesis rates of HDL protein of 89.8±33.7 mg/d in NAR and 17.4±6.5 mg/d in SDR (P=0.0122). Furthermore, Swiss mouse macrophage free-cholesterol (FC) efflux rates, measured as the percent [14C]-cholesterol efflux/6 h, were 8.2±2.3 (n=9) in NAR HDL and 11.2±3.2 (n=10) in SDR HDL (P=0.03). Therefore, in NAR the modification of the HDL composition slows down the cell FC efflux rate, and together with the
increased rate of plasma HDL metabolism influences the reverse cholesterol transport system. 相似文献
73.
Vivian W. Y. TAM Jianzhuang XIAO Sheng LIU Zixuan CHEN 《Frontiers of Structural and Civil Engineering》2019,13(3):628
The paper investigates the behaviors of recycled aggregate concrete-filled steel tubular (RACFST) columns under eccentric loadings with the incorporation of expansive agents. A total of 16 RACFST columns were tested in this study. The main parameters varied in this study are recycled coarse aggregate replacement percentages (0%, 30%, 50%, 70%, and 100%), expansive agent dosages (0%, 8%, and 15%) and an eccentric distance of compressive load from the center of the column (0 and 40 mm). Experimental results showed that the ultimate stresses of RACFST columns decreased with increasing recycled coarse aggregate replacement percentages but appropriate expansive agent dosages can reduce the decrement; the incorporation of expansive agent decreased the ultimate stresses of RACFST columns but an appropriate dosage can increase the deformation ability. The recycled coarse aggregate replacement percentages have limited influence on the ultimate stresses of the RACFST columns and has more effect than that of the normal aggregate concrete-filled steel tubular columns. 相似文献
74.
Sai On Cheung Chi Ming Tam Vivian Tam Kevin Cheung Henry Suen 《Construction Management & Economics》2013,31(9):927-935
In response to the increasing public concern over the effects of construction waste on the environment, a performance assessment system has been designed to provide an instant, online assessment of how well a construction site performs environmentally, e.g. measuring the level of pollution generated from a construction site. Through the use of both Internet and database technologies, it is possible to collect and present data that are essential for environmental management online. To achieve this, a set of environmental performance parameters was derived through a postal questionnaire survey and interviews with experts in the field. A conceptual framework was developed, of which the key components were: template, knowledge base, output data and benchmark group. In combination, these factors provide a system that enables speedy assessment and effective management of environmental performance on construction sites, hence prompt decisions can be made and corrective actions can be taken before potential hazards turn into real disasters. 相似文献
75.
Environmental problems have been considered as a serious situation in Hong Kong construction. Waste management is pressing harder with the alarming signal warning the industry. Reuse, recycling and reducing the wastes are considered as the only methods to recover the wastes generated; however, the implementations still have much room for improvement. In order to ameliorate the existing situations, evaluations of the existing waste recycling methods are studied in this research. A telephone interviewing to the recyclers, site visits to the construction and demolition sites (including the Lower Ngau Tau Kok Estate Phase 1) and the centralized recycling plant in Tuen Mun Area 38 are under investigation. Difficulties encountered for various recycling parties are investigated. Rather than the poor quality found from the recyclable materials, they found the high investment cost, lengthy demolition period and limited space caused the major barriers for them. Therefore, some recommendations are suggested: (i) proposing a higher landfill charging scheme; (ii) setting up a centralized centre for recycling the materials; (iii) examining the Hong Kong government should be supported in the provision of land for recycling plants; (iv) implementing innovative demolition methods; (v) allowing some locations in town for residents’ easy access to drop-off recyclable materials; (vi) allowing flexible demolition periods; (vii) setting up recycling plant in town or in the form of mobile installations; (viii) reusing the reusable components as donations to the charity organization; (ix) providing higher flexibility in receiving concrete waste in Tuen Mun Area 38 recycling plant; and (x) balancing the supply and demand of recycled materials through legislations or incentive schemes. 相似文献
76.
Moeck Christian Merk Markus Radny Dirk Auckenthaler Adrian Schirmer Mario Gabriel Thomas 《Grundwasser》2022,27(3):187-196
Grundwasser - Eine nachhaltige Wasserversorgung in urbanen Gebieten stellt aufgrund des Nutzungsdrucks sowie vielfältiger anthropogener Einträge eine große Herausforderung dar.... 相似文献
77.
Vivian E. Ferry Jeremy N. Munday Harry A. Atwater 《Advanced materials (Deerfield Beach, Fla.)》2010,22(43):4794-4808
This paper reviews the recent research progress in the incorporation of plasmonic nanostructures with photovoltaic devices and the potential for surface plasmon enhanced absorption. We first outline a variety of cell architectures incorporating metal nanostructures. We then review the experimental fabrication methods and measurements to date, as well as systematic theoretical studies of the optimal nanostructure shapes. Finally we discuss photovoltaic absorber materials that could benefit from surface plasmon enhanced absorption. 相似文献
78.
We demonstrated a versatile approach to obtain layered nanoparticle sheets with in-plane hexagonal order and 3-D ordered arrays of single nanoparticle chains in thin films upon blending nanoparticles with block copolymer (BCP)-based supramolecules. Basic understanding on the thermodynamic and kinetic aspects of the assembly process paved a path to manipulate these assemblies to meet demands in nanoparticle-based device fabrication and understand structure-property correlations. 相似文献
79.
Liao CM Chio CP Chen WY Ju YR Li WH Cheng YH Liao VH Chen SC Ling MP 《Journal of hazardous materials》2011,190(1-3):150-158
Exposures to carcinogenic polycyclic aromatic hydrocarbons (PAHs) have been linked to human lung cancer. The purpose of this study was to assess lung cancer risk caused by inhalation exposure to nano/ultrafine particle-bound PAHs at the population level in Taiwan appraised with recent published data. A human respiratory tract model was linked with a physiologically based pharmacokinetic model to estimate deposition fraction and internal organic-specific PAHs doses. A probabilistic risk assessment framework was developed to estimate potential lung cancer risk. We reanalyzed particle size distribution, total-PAHs, particle-bound benzo(a)pyrene (B[a]P) and PM concentrations. A dose-response profile describing the relationships between external B[a]P concentration and lung cancer risk response was constructed based on population attributable fraction (PAF). We found that 90% probability lung cancer risks ranged from 10(-5) to 10(-4) for traffic-related nano and ultrafine particle-bound PAHs, indicating a potential lung cancer risk. The particle size-specific PAF-based excess annual lung cancer incidence rate due to PAHs exposure was estimated to be less than 1 per 100,000 population, indicating a mild risk factor for lung cancer. We concluded that probabilistic risk assessment linked PAF for limiting cumulative PAHs emissions to reduce lung cancer risk plays a prominent role in future government risk assessment program. 相似文献
80.
Songshan Zeng Rui Li Stephan G. Freire Vivian M. M. Garbellotto Emily Y. Huang Andrew T. Smith Cong Hu William R. T. Tait Zichao Bian Guoan Zheng Dianyun Zhang Luyi Sun 《Advanced materials (Deerfield Beach, Fla.)》2017,29(24)
The wrinkle dynamics (such as reversibility and stability) of human skin are affected by the external stimuli, as well as the skin's structure and mechanical properties. Inspired by these tunable responses, three types of moisture‐responsive wrinkle dynamics are achieved, for the first time, through a single film–substrate system. These dynamics include: (1) completely reversible wrinkles formation; (2) irreversible wrinkles formation I: the initially formed wrinkles can be permanently erased and never reappear; and (3) irreversible wrinkles formation II: once the wrinkles form, they can no longer be erased. The key to success is to control the stiffness and thickness ratios of the film and the substrate, and tailor the crosslink degree/gradient of the film to allow for moisture‐dependent changes of modulus and swelling degree. These unique responsive dynamics motivate the invention of a series of optical devices triggered by moisture, including anticounterfeit tabs, encryption devices, water indicators, light diffusors, and antiglare films. This study also paves the road for further understanding of the skin wrinkling dynamics and manipulation. 相似文献