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排序方式: 共有372条查询结果,搜索用时 8 毫秒
1.
Zaidatul Akmal Othman Zaida Zakaria Joseph Bagi Suleiman Victor Udo Nna Aminah Che Romli Wan Syaheedah Wan Ghazali Mahaneem Mohamed 《International journal of molecular sciences》2021,22(8)
Obesity and hyperlipidemia are major risk factors for developing vascular diseases. Bee bread (BB) has been reported to exhibit some biological actions, including anti-obesity and anti-hyperlipidemic. This study aims to investigate whether bee bread can ameliorate vascular inflammation and impaired vasorelaxation activity through eNOS/NO/cGMP pathway in obese rats. Forty male Sprague-Dawley rats were randomly divided into four groups (n = 10/group), namely: control (normal group), obese rats (OB group), obese rats treated with bee bread (0.5 g/kg/day, OB/BB group) and obese rats treated with orlistat (10 mg/kg/day, OB/OR group). The latter three groups were given a high-fat diet (HFD) for 6 weeks to induced obesity before being administered with their respective treatments for another 6 weeks. After 12 weeks of the total experimental period, rats in the OB group demonstrated significantly higher Lee obesity index, lipid profile (total cholesterol, triglyceride, low-density lipoprotein), aortic proinflammatory markers (tumor necrosis factor-α, nuclear factor-κβ), aortic structural damage and impairment in vasorelaxation response to acetylcholine (ACh). Bee bread significantly ameliorated the obesity-induced vascular damage manifested by improvements in the lipid profile, aortic inflammatory markers, and the impaired vasorelaxation activity by significantly enhancing nitric oxide release, promoting endothelial nitric oxide synthase (eNOS) and cyclic guanosine monophosphate (cGMP) immunoexpression. These findings suggest that the administration of bee bread ameliorates the impaired vasorelaxation response to ACh by improving eNOS/NO/cGMP-signaling pathway in obese rats, suggesting its vascular therapeutic role. 相似文献
2.
A new construction for the rotor windings of balanced wound-rotor induction motors employed in the slip energy recovery drives is proposed, in this paper, to reduce the time harmonics which are commonly generated in the machine. The proposed machine has a double-circuit in the rotor. One circuit is star connected while the other is delta connected. Each of these two circuits is connected to a diode-bridge rectifier to achieve a twelve-pulse operation characteristics. The main objective of this paper is to develop a new model which is capable of simulating the proposed machine, neglecting nonlinearities due to magnetic saturation, and its associated converters. Such a model is further complicated due to the presence of the two rotor circuits and their mutual interaction 相似文献
3.
Zakaria Chajar Michel Primet Hélène Praliaud Michèle Chevrier Catherine Gauthier Frédéric Mathis 《Catalysis Letters》1994,28(1):33-40
The role of nitrogen dioxide in the selective reduction of NO by propane over a Cu-MFI zeolite is investigated. NO2 and NO reductions were carried out under similar conditions of reaction. In the presence of oxygen, the reduction of NO by C3H8 does not differ significantly from that of NO2. In the absence of oxygen, the reduction of NO2 by propane occurs with a partial decomposition of the nitric dioxide molecule. Such a decomposition leads to the formation of oxygen, which is responsible for the increase in catalytic activity by comparison with the same reaction performed with NO. NO2 formed and released in the gas phase during the reduction of NO by propane in the presence of oxygen does not play a predominant role in the catalytic process. 相似文献
4.
5.
Privacy issues are frequently discussed amongst researchers, practitioners and patients in healthcare. However, psychiatric patients’ privacy issues get less attention in information system development (ISD), whereby they are one of the most important stakeholders. This paper applies Carew and Stapleton’s ISD privacy framework to psychiatric monitoring systems to understand the issues that are related to monitoring psychiatric patients’ behaviour. By understanding the privacy issues amongst patients, the research will be able to provide guidance to system developers to produce a privacy-sensitive system that can contribute to the system engineering for international stability. We will elaborate each factor in the framework (physical, social, psychological and informational) and then explain the relationship to the privacy of psychiatric patient. 相似文献
6.
A novel concept for integrating fuel cells with desalination systems is proposed and investigated in this work. Two unique case studies are discussed — the first involving a hybrid system with a reverse osmosis (RO) unit and the second — integrating with a thermal desalination process such as multi-stage flash (MSF). The underlying motivation for this system integration is that the exhaust gas from a hybrid power plant (fuel cell/turbine system) contains considerable amount of thermal energy, which may be utilized for desalination units. This exhaust heat can be suitably used for preheating the feed in desalination processes such as reverse osmosis which not only increases the potable water production, but also decreases the relative energy consumption by approximately 8% when there is an increase of just 8°C rise in temperature. Additionally, an attractive hybrid system application which combines power generation at 70%+ system efficiency with efficient waste heat utilization is thermal desalination. In this work, it is shown that the system efficiency can be raised appreciably when a high-temperature fuel cell co-generates DC power in-situ with waste heat suitable for MSF. Results indicate that such hybrid system could show a 5.6% increase in global efficiency. Such combined hybrid systems have overall system efficiencies (second-law base) exceeding those of either fuel-cell power plants or traditional desalination plants. 相似文献
7.
Accurate location or positioning of people and self-driven devices in large indoor environments has become an important necessity The application of increasingly automated self-operating moving transportation units, in large indoor spaces demands a precise knowledge of their positions. Technologies like WiFi and Bluetooth, despite their low-cost and availability, are sensitive to signal noise and fading effects. For these reasons, a hybrid approach, which uses two different signal sources, has proven to be more resilient and accurate for the positioning determination in indoor environments. Hence, this paper proposes an improved hybrid technique to implement a fingerprinting based indoor positioning, using Received Signal Strength information from available Wireless Local Area Network access points, together with the Wireless Sensor Networks technology. Six signals were recorded on a regular grid of anchor points, covering the research space. An optimization was performed by relative signal weighting, to minimize the average positioning error over the research space. The optimization process was conducted using a standard Quantum Particle Swarm Optimization, while the position error estimate for all given sets of weighted signals was performed using a Multilayer Perceptron (MLP) neural network. Compared to our previous research works, the MLP architecture was improved to three hidden layers and its learning parameters were finely tuned. These experimental results led to the 20% reduction of the positioning error when a suitable set of signal weights was calculated in the optimization process. Our final achieved value of 0.725 m of the location incertitude shows a sensible improvement compared to our previous results. 相似文献
8.
Kamarulzaman Kamarudin Syed Muhammad Mamduh Ali Yeon Md Shakaff Shaharil Mad Saad Ammar Zakaria Abu Hassan Abdullah 《仪器科学与技术》2013,41(1):74-88
Characterization and calibration of gas sensor is a complex problem due to the dynamic behavior of gases and the limitations of current technology. This article reports a flexible, robust, and autonomous integrated system that is able to perform characterization on metal oxide-based gas sensors in dynamic environments. The system controls the concentration and flow of the relevant gases into the gas chamber and simultaneously measuring the sensor response. This feature allows the characterization of the sensor under continuous dynamic flow of gases similar to conditions on a robot or flow pipes. Several experiments have been performed on the system using hydrogen sulfide. The results provide information on the general characteristics of the sensor as well as its sensitivity. The noise levels were studied with different reference voltages. Overall, the results verify that the system is reliable and able to produce repeatable measurements. 相似文献
9.
Scheduling plays a vital role in ensuring the effectiveness of the production control of a flexible manufacturing system (FMS). The scheduling problem in FMS is considered to be dynamic in its nature as new orders may arrive every day. The new orders need to be integrated with the existing production schedule immediately without disturbing the performance and the stability of existing schedule. Most FMS scheduling methods reported in the literature address the static FMS scheduling problems. In this paper, rescheduling methods based on genetic algorithms are described to address arrivals of new orders. This study proposes genetic algorithms for match-up rescheduling with non-reshuffle and reshuffle strategies which accommodate new orders by manipulating the available idle times on machines and by resequencing operations, respectively. The basic idea of the match-up approach is to modify only a part of the initial schedule and to develop genetic algorithms (GAs) to generate a solution within the rescheduling horizon in such a way that both the stability and performance of the shop floor are kept. The proposed non-reshuffle and reshuffle strategies have been evaluated and the results have been compared with the total-rescheduling method. 相似文献
10.
Zakaria Farah 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1979,168(5):394-396
Summary Non-casein protein fractions of raw skim med milk, obtained according to the Aschaffenburg and Drewry procedure, were studied by discontinuous polyacrylamide electrophoresis.Differences between the electropherograms obtained and the data of the above authors were observed in the fractions non-casein nitrogen minus proteose peptone nitrogen and total albumin nitrogen plus non-protein nitrogen.In the first fraction, instead of immunoglobulin, proteose-peptone was present and in the second fraction, besides the total albumin, immunglobulin and proteose-peptone were present. In our opinion the differences observed in the two fractions are due to incomplete salting out.
Überprüfung der Aschaffenburg und Drewry-Bestimmungsmethode der Nicht-Casein-Proteine durch Polyacrylamid-Elektrophorese
Zusammenfassung Es wurden Nicht-Casein-Protein-Fraktionen von roher Magermilch, die nach der Aschaffenburg- und Drewry-Methode getrennt wurden, discelektrophoretisch untersucht. Unterschiede zwischen den erhaltenen Elektropherogrammen und den Angaben der oben genannten Autoren wurden bei den Fraktionen Nicht-Casein-Stickstoff minus Proteose-Pepton-Stickstoff und Totalalbumin-Stickstoff plus Nicht-Protein-Stickstoff festgestellt.Bei der ersten Fraktion wurde das Proteose-Pepton anstatt Immunglobulin erhalten, und bei der zweiten Fraktion erhielt man neben dem Totalalbumin auch Immunglobulin und Proteose-Pepton. Nach unserer Auffassung sind die bei den beiden Fraktionen festgestellten Abweichungen auf unvollständiges Aussalzen zurückzuführen.相似文献