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11.
Gold nanorods (GNRs) have promising applications in drug delivery and cancer treatment and are generally administered via direct injection into the circulation. Thus it is necessary to evaluate their potential adverse effects on blood vessels. Herein, GNRs with various surface modifications are used to evaluate the toxicity and cellular uptake of GNRs into vascular endothelial and smooth muscle cells of isolated rat aortic rings. Surfactant-capped GNRs are synthesized and either coated with polyelectrolyte (PE) to prepare PE-GNRs, or modified with thiolated polyethylene glycol (PEG) to prepare PEG-GNRs. Using toxicity assays, small-vessel myography, fluorescence microscopy, and electron microscopy, it is shown that therapeutic concentrations of PE-GNRs but not PEG-GNRs are toxic to the vascular endothelium, which leads to an impaired relaxation function of aortic rings. However, no toxicity to smooth muscles is observed. Moreover, electron microscopy analysis confirms the cellular uptake of PE-GNRs but not PEG-GNRs into the endothelium of exposed aortic rings. The difference in toxicity and cellular uptake of PE-GNRs versus PEG-GNRs is explained and linked to free surfactant molecules and protein adsorption, respectively. The results indicate that toxicity and cellular uptake in the vascular endothelium in blood vessels are potential adverse effects of systemically administered GNR solutions, which can be prevented by appropriate surface functionalization.  相似文献   
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Asphalt binder viscosity is of great importance during the production process of hot mix asphalt mixture as typically asphalt plants will store binders between 149 °C and 177 °C. SHRP guidelines state that asphalt binder viscosity must not exceed 3 Pa s. Therefore, given the documented increases in asphalt viscosity when modified with crumb rubber modifier (CRM) it is necessary to produce asphalt binder that fulfills the SHRP criteria while not exceeding plant mixing and storing requirements. This paper reports the results of an investigation of the importance of CRM properties on viscosity of CRM binder. Two binder sources were modified at four concentration levels using four different crumb rubber sources; the viscosities of the produced binders were evaluated by AASHTO T 316. Crumb rubber properties were evaluated by elemental analysis using a scanning electron microscope (SEM) and by determination of glass transition temperature (Tg) using a differential scanning calorimeter (DSC). In general, results indicate that processing procedure and tire type plays an important role in the determination of CRM binder viscosity.  相似文献   
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Participatory optimization scenario process was developed for water resources management of the Zarqa River Basin in Jordan. The basin was selected to represent a case study of semi-arid area in the Mediterranean because of its entire range of prototypical water management problems. The nature of the institutional framework, the severity of the water related problems and concentration of population in the basin have required the need for stakeholders’ involvement in the optimization process. The paper demonstrates a Water Resources Model (WRM) consisting of integrated cascade of modules, embedded in a framework of a participatory approach in water resources optimization. The system includes baseline scenario, identification of constrains and instruments, the optimization scenario and analysis of results. In a participatory approach, stakeholders identified the optimization criteria (constraints) and the management interventions (instruments). Constraints were set to securing high supply/demand ratio of 0.98 and improving reliability of supply to 75 %, while specific eight instruments were suggested and manipulated by the model to achieve the above criteria. The results of the WRM optimization scenario showed that the specified constraints were met so that the supply/demand ratio increased from 0.90 to 0.996 and the reliability of supply improved from 58 % to 84 %. The benefit/cost ratio, water shortfall, and the economic efficiency had responded effectively. The model proved its efficiency in using the full featured basin characteristics towards baseline and optimization scenarios with the support of stakeholders in simulating the basin behavior over time using the model parameters.  相似文献   
15.
Machine-learning based classification of speech and music   总被引:2,自引:0,他引:2  
The need to classify audio into categories such as speech or music is an important aspect of many multimedia document retrieval systems. In this paper, we investigate audio features that have not been previously used in music-speech classification, such as the mean and variance of the discrete wavelet transform, the variance of Mel-frequency cepstral coefficients, the root mean square of a lowpass signal, and the difference of the maximum and minimum zero-crossings. We, then, employ fuzzy C-means clustering to the problem of selecting a viable set of features that enables better classification accuracy. Three different classification frameworks have been studied:Multi-Layer Perceptron (MLP) Neural Networks, radial basis functions (RBF) Neural Networks, and Hidden Markov Model (HMM), and results of each framework have been reported and compared. Our extensive experimentation have identified a subset of features that contributes most to accurate classification, and have shown that MLP networks are the most suitable classification framework for the problem at hand.  相似文献   
16.
The divalent selective electrode together with high precision solid state, digital pH -mv -meter makes broader application of potentiometry in physical and inorganic chemistry a certainty. The above set-up is used to determine the stoichiometric constants, K, for Ca and Mg ions association with formates, acetates, propionates and butyrates at 25°, 35° and 45°C in aqueous media. The K-values were converted to infinite dilution KA values were found to be 8.4 LM−1, 10.4 LM−1, 19.1 LM−1 and 19.3 LM−1 for calcium salts of formate, acetate, propionate and butyrate respectively. Also KA values for Mg salts of formate, acetate, propionate and butyrate were found to be 7.8 LM−1, 9.5 LM−1, 13.1 LM−1 and 13.1 LM−1 respectively. Other thermodynamic parameters such as ΔG°, ΔH° and ΔS° are also obtained from the variation of KA with temperature for each salt. The data are interpreted relative to each other on basis of pKa of the corresponding organic acid. Their temperature behaviour is similar to those salts derived from strong acids such as sulphates, rather than weak acids.  相似文献   
17.
The purpose of this study is to evaluate the adequacy of the 100-year discharge along with the Froehlich bridge abutment scour equation adopted by the U.S. Federal Highway Administration (FHwA) in predicting abutment scour for bridge design purposes in South Carolina streams. The analysis utilized bridge properties, stream cross-sectional and hydraulic data, local flood frequency equations, a one-dimensional steady river flow computer model (WSPRO), and procedures recommended by the FHwA for predicting abutment scour. A method was developed to identify the single stream-discharge at each bridge that can cause the abutment scour that was observed at 73 bridge abutments. Analysis of the results revealed that for one-third of the abutments in the sandy soil region of South Carolina, the flow rates required to produce the observed scour depths had return periods greater than 100?years. Although for bridges in the region dominated by clay soil, the return periods were significantly smaller than 100?years.  相似文献   
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The structure-preserving features of the nonlinear stochastic models are positivity, dynamical consistency and boundedness. These features have a significant role in different fields of computational biology and many more. Unfortunately, the existing stochastic approaches in literature do not restore aforesaid structure-preserving features, particularly for the stochastic models. Therefore, these gaps should be occupied up in literature, by constructing the structure-preserving features preserving numerical approach. This writing aims to describe the structure-preserving dynamics of the stochastic model. We have analysed the effect of reproduction number in stochastic modelling the same as described in the literature for deterministic modelling. The usual explicit stochastic numerical approaches are time-dependent. We have developed the implicitly driven explicit approach for the stochastic epidemic model. We have proved that the newly developed approach is preserving the structural, dynamical properties as positivity, boundedness and dynamical consistency. Finally, convergence analysis of a newly developed approach and graphically illustration is also presented.  相似文献   
20.
Fixed point theory is one of the most important subjects in the setting of metric spaces since fixed point theorems can be used to determine the existence and the uniqueness of solutions of such mathematical problems. It is known that many problems in applied sciences and engineering can be formulated as functional equations. Such equations can be transferred to fixed point theorems in an easy manner. Moreover, we use the fixed point theory to prove the existence and uniqueness of solutions of such integral and differential equations. Let X be a non-empty set. A fixed point for a self-mapping T on X is a point  相似文献   
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