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排序方式: 共有630条查询结果,搜索用时 234 毫秒
121.
Emissions of particulate matter (PM) from vehicle and industrial sources constitute a hazard to human health. Here, we apply biomagnetic monitoring to (a) discriminate between potential PM(10) sources around a steelworks and (b) examine magnetic source differentiation for a combined, U.K.-based, magnetic data set (steelworks, roadside, power-generating site). Tree leaves (sampled September 2009, as passive PM receptors) and putative sources were subjected to rapid magnetic characterization (magnetic remanence measurements). Fuzzy cluster analysis of the combined data set identified three clusters, showing that particulates emitted from vehicle fleets (e.g., diesel/petrol), and from different industrial processes can be magnetically differentiated. Cluster analysis of the steelworks leaf receptors and potential sources identified seven magnetic groupings. Leaves from one PM "hotspot" showed no affinity with any available source sample, suggesting an as yet untested PM source. These data indicate the value of fast, inexpensive magnetic techniques for particulate source discrimination and indication of "missing" sources. 相似文献
122.
Groundwater discharge could be a major, but as yet poorly constrained, source of carbon dioxide to lakes, wetlands, rivers, estuaries, and coastal waters. We demonstrate how coupled radon ((222)Rn, a natural groundwater tracer) and pCO(2) measurements in water can be easily performed using commercially available gas analysers. Portable, automated radon and pCO(2) gas analysers were connected in series and a closed air loop was established with gas equilibration devices (GED). We experimentally assessed the advantages and disadvantages of six GED. Response times shorter than 30 min for (222)Rn and 5 min for pCO(2) were achieved. Field trials revealed significant positive correlations between (222)Rn and pCO(2) in estuarine waterways and in a mangrove tidal creek, implying that submarine groundwater discharge was a source of CO(2) to surface water. The described system can provide high resolution, high precision concentrations of both radon and pCO(2) with nearly no additional effort compared to measuring only one of these gases. Coupling automated (222)Rn and pCO(2) measurements can provide new insights into how groundwater seepage contributes to aquatic carbon budgets. 相似文献
123.
Maher M Al‐Dabbas Mohammed Saleh Mahmoud H Abu‐Ghoush Khalid Al‐Ismail Tareq Osaili 《International Journal of Dairy Technology》2014,67(3):427-436
Microbial levels were significantly (P < 0.05) affected by the temperature‐time treatments used during in‐container heat treatment of the curd, brine concentration and storage duration. A heat treatment of 115 °C × 2 min, in the absence of NaCl, was sufficient to eliminate Mesophilic micro‐organisms, Coliforms, Staphylococcus aureus and Yeast and Moulds for the duration of 1 year of storage. Sensory scores for colour, appearance and texture increased significantly (P < 0.05) with the increase in the NaCl in brine concentration regardless of the temperature‐time treatment. 相似文献
124.
Simpson Helen Blair; Maher Michael J.; Wang Yuanjia; Bao Yuanyuan; Foa Edna B.; Franklin Martin 《Canadian Metallurgical Quarterly》2011,79(2):247
Objective: To examine the effects of patient adherence on outcome from exposure and response prevention (EX/RP) therapy in adults with obsessive-compulsive disorder (OCD). Method: Thirty adults with OCD were randomized to EX/RP (n = 15) or EX/RP augmented by motivational interviewing strategies (n = 15). Both treatments included 3 introductory sessions and 15 exposure sessions. Because there were no significant group differences in adherence or outcome, the groups were combined to examine the effects of patient adherence on outcome. Independent evaluators assessed OCD severity using the Yale–Brown Obsessive Compulsive Scale. Therapists assessed patient adherence to between-session EX/RP assignments at each session using the Patient EX/RP Adherence Scale (PEAS). Linear regression models were used to examine the effects of PEAS scores on outcome, adjusting for baseline severity. The relationship between patient adherence and other predictors of outcome was explored using structural equation modeling. Results: Higher average PEAS ratings significantly predicted lower posttreatment OCD severity in intent-to-treat and completer samples. PEAS ratings in early sessions (5–9) also significantly predicted posttreatment OCD severity. The effects of other significant predictors of outcome in this sample (baseline OCD severity, hoarding subtype, and working alliance) were fully mediated by patient adherence. Conclusions: Patient adherence to between-session EX/RP assignments significantly predicted treatment outcome, as did early patient adherence and change in early adherence. Patient adherence mediated the effects of other predictors of outcome. Future research should develop interventions that increase adherence and then test whether increasing adherence improves outcome. If effective, these interventions could then be used to personalize care. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
125.
Ghayth Rigane Maher Boukhris Mohamed Bouaaziz Sami Sayadi Ridha Ben Salem 《Journal of the science of food and agriculture》2013,93(5):1242-1248
BACKGROUND: The characterisation of virgin olive oils from two Tunisian cultivars, growing in the Tataouin zone, namely Jemri‐Bouchouka, a rare olive cultivar, and Chemlali‐Tataouin, was carried out. Several analytical parameters were evaluated; these include quality index, fatty acids, phenolic, chlorophyll, carotenoid, squalene, α‐tocopherol compositions and oxidative stability. RESULTS: Jemri‐Bouchouka olive oil had the highest value of oleic acid (74.50%) while Chemlali‐Tataouin was characterised by a high percentage of palmitic acid (14.75%), which makes this oil freeze at a low temperature. On the other hand, Jemri‐Bouchouka oil was characterised by a low phenolic and α‐tocopherol content (267.72 mg GAE kg?1 and 278.34 mg kg?1, respectively). Ten phenolic compounds were identified. The main phenols found in the two olive oils were oleuropein aglycon and pinoresinol. All phenolic compounds showed significant correlations with oxidative stability. CONCLUSION: The analytical parameters of virgin olive oil that were determined in this study were greatly influenced by cultivar. © 2012 Society of Chemical Industry 相似文献
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128.
In this paper, we introduce the splitter placement problem in wavelength-routed networks (SP-WRN). Given a network topology, a set of multicast sessions, and a fixed number of multicast-capable cross-connects, the SP-WRN problem entails the placement of the multicast-capable cross-connects so that the blocking probability is minimized. The SP-WRN problem is NP-complete as it includes as a subproblem the routing and wavelength assignment problem which is NP-complete. To gain a deeper insight into the computational complexity of the SP-WRN problem, we define a graph-theoretic version of the splitter placement problem (SPG), and show that even SPG is NP-complete. We develop three heuristics for the SP-WRN problem with different degrees of trade-off between computation time and quality of solution. The first heuristic uses the CPLEX general solver to solve an integer-linear program (ILP) of the problem. The second heuristic is based on a greedy approach and is called most-saturated node first (MSNF). The third heuristic employs simulated annealing (SA) with route-coordination. Through numerical examples on a wide variety of network topologies we demonstrate that: (1) no more than 50% of the cross-connects need to be multicast-capable, (2) the proposed SA heuristic provides fast near-optimal solutions, and (3) it is not practical to use general solvers such as CPLEX for solving the SP-WRN problem. 相似文献
129.
Mohammed H. Alser Maher M. Assaad Fawnizu A. Hussin 《International Journal of Electronics》2013,100(11):1546-1556
In this article, an FPGA-based design and implementation of a fully digital wide-range programmable frequency synthesizer based on a finite state machine filter is presented. The advantages of the proposed architecture are that, it simultaneously generates a high frequency signal from a low frequency reference signal (i.e. synthesising), and synchronising the two signals (signals have the same phase, or a constant difference) without jitter accumulation issue. The architecture is portable and can be easily implemented for various platforms, such as FPGAs and integrated circuits. The frequency synthesizer circuit can be used as a part of SERDES devices in intra/inter chip communication in system-on-chip (SoC). The proposed circuit is designed using Verilog language and synthesized for the Altera DE2-70 development board, with the Cyclone II (EP2C35F672C6) device on board. Simulation and experimental results are included; they prove the synthesizing and tracking features of the proposed architecture. The generated clock signal frequency of a range from 19.8?MHz to 440?MHz is synchronized to the input reference clock with a frequency step of 0.12?MHz. 相似文献
130.
Abdullah Saad Abdullah Ibrahim El Tantawy El Sayed Abdel Moneim A. El-Torgoman Abul Kalam S. Wageh Maher A. Kamel 《International journal of molecular sciences》2022,23(10)
Background: Silymarin (SIL) has long been utilized to treat a variety of liver illnesses, but due to its poor water solubility and low membrane permeability, it has a low oral bioavailability, limiting its therapeutic potential. Aim: Design and evaluate hepatic-targeted delivery of safe biocompatible formulated SIL-loaded chitosan nanoparticles (SCNPs) to enhance SIL’s anti-fibrotic effectiveness in rats with CCl4-induced liver fibrosis. Methods: The SCNPs and chitosan nanoparticles (CNPs) were prepared by ionotropic gelation technique and are characterized by physicochemical parameters such as particle size, morphology, zeta potential, and in vitro release studies. The therapeutic efficacy of successfully formulated SCNPs and CNPs were subjected to in vivo evaluation studies. Rats were daily administered SIL, SCNPs, and CNPs orally for 30 days. Results: The in vivo study revealed that the synthesized SCNPs demonstrated a significant antifibrotic therapeutic action against CCl4-induced hepatic injury in rats when compared to treated groups of SIL and CNPs. SCNP-treated rats had a healthy body weight, with normal values for liver weight and liver index, as well as significant improvements in liver functions, inflammatory indicators, antioxidant pathway activation, and lipid peroxidation reduction. The antifibrotic activities of SCNPs were mediated by suppressing the expression of the main fibrosis mediators TGFβR1, COL3A1, and TGFβR2 by boosting the hepatic expression of protective miRNAs; miR-22, miR-29c, and miR-219a, respectively. The anti-fibrotic effects of SCNPs were supported by histopathology and immunohistochemistry (IHC) study. Conclusions: According to the above results, SCNPs might be the best suitable carrier to target liver cells in the treatment of liver fibrosis. 相似文献