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排序方式: 共有323条查询结果,搜索用时 15 毫秒
91.
Kaustav Majumder Sareh Panahi Susan Kaufman Jianping Wu 《Journal of Functional Foods》2013,5(1):187-194
Our previous study showed that in vitro simulated gastrointestinal digestion of fried whole egg (FWE) released several peptides with angiotensin converting enzyme-I (ACE-I) inhibitory properties. The present study evaluated in vivo blood pressure lowering effect of FWE digest in spontaneously hypertensive rats (SHR). Twelve to fourteen weeks old male SHRs were surgically implanted with telemetric blood pressure (BP) measuring devices. After one week recovery, animals were randomly allocated to three groups at dosage of FWE digest 0 (control), 100, and 1000 mg of FWE digest/kg body weight for 3 days (n = 8), and the BP was recorded continuously. The 1000 mg/kg BW group showed a significant decrease in BP and also rectified the impaired circadian blood pressure rhythm compared to the control group. This study indicates a potential blood pressure lowering effect of egg consumption. 相似文献
92.
Ovotransferrin-derived peptides showed synergistic effects with vitamin C, epigallocatechin gallate (EGCG), and caffeic acid, but not quercetin in our previous report. In this study, we further investigated the interactions between ovotransferrin-derived peptides and teas, based on the oxygen radical absorbance capacity (ORAC) assay. Our results showed that there was no significant difference in ORAC values among green, oolong, and black teas. For all the samples, 80% methanol extracts possessed better antioxidant capacity than hot water extracts. The antioxidant capacity of teas were improved by adding either ovotransferrin hydrolysate or its purified peptide IRW; however, adding hydrolysate did not improve antioxidant stability of teas. ORAC values of both teas and hydrolysate added teas were decreased during 22weeks of storage, while samples stored at 4°C exhibited higher antioxidant capacity than those stored at room temperature. This suggested that ovotransferrin hydrolysate could be used as functional food ingredients in enhancing antioxidant capacities of foods, which would benefit human nutrition and health. 相似文献
93.
Effect of dextrans on cryopreservation of goat cauda epididymal spermatozoa using a chemically defined medium 总被引:1,自引:0,他引:1
Kundu CN Chakrabarty J Dutta P Bhattacharyya D Ghosh A Majumder GC 《Reproduction (Cambridge, England)》2002,123(6):907-913
Experiments were carried out to investigate the cryoprotecting potential of dextrans (ranging from 10 to 2000 kDa) using a synthetic model system developed recently in this laboratory. Goat spermatozoa from the cauda epididymidis were extracted in a chemically defined medium (modified Ringer's solution) and assayed for motility using a phase-contrast microscope. The sperm cells were subjected to a freezing protocol in a computer-controlled biofreezer (cooling at 0.25 degrees C min(-1) to 5 degrees C; 5 degrees C min(-1) to -20 degrees C; 20 degrees C min(-1) to -100 degrees C) and plunged into liquid nitrogen. The frozen cells were thawed rapidly at 37 degrees C in a thermostatic waterbath. In the absence of dextran, all the spermatozoa lost their motility. The cryoprotecting efficacy of each dextran was found to be biphasic in nature. Initially, as the concentration of dextran was increased, the recovery of sperm motility also increased and reached an optimum value; however, with further increases in dextran concentration, the recovery of motility decreased sharply. Of all the sugar polymers tested, 10 kDa dextran showed the highest cryoprotecting efficacy, whereas the 2000 kDa sugar polymer was the least active. Dextrans of 10, 40, 73, 173, 252, 500 and 2000 kDa offered maximum cryorecovery of forward motility to the extent of approximately 23%, 21%, 19%, 18%, 16%, 15% and 8%, respectively. Optimum concentrations of these dextrans for cryoprotection of sperm motility were 8.42, 2.50, 1.09, 0.37, 0.31, 0.10 and 0.04 mmol l(-1), respectively. It thus appears that each dextran has a characteristic cryoprotection profile. The data show that the cryoprotecting efficacy and optimum cryoprotecting concentrations of dextrans are inversely related to their molecular mass. Dextran also served as a significant cryoprotectant in the presence of glycerol (0.87 mol l(-1)) and dimethyl sulphoxide (0.76 mol l(-1)), which are well known cryoprotectants; the action of the combined cryoprotectants was almost additive. The presence of glycerol or glycerol plus dimethyl sulphoxide caused a significant reduction (from 8.42 to 6.27 mmol l(-1)) in the optimum concentration of dextran. In the presence of the three cryoprotectants, recovery of sperm motility was as high as 58% (forward motility) and 60% (total motility). 相似文献
94.
V. Ambardekar T. Bhowmick P.P. Bandyopadhyay S.B. Majumder 《International Journal of Hydrogen Energy》2021,46(44):23113-23123
Though the gas sensing properties of atmospheric plasma sprayed tungsten oxide, zinc oxide, titanium oxide, tin oxide and copper oxide coatings were well investigated, reports comparing sensing characteristics of plasma sprayed sensor thick film coating with its bulk counterpart are hardly found in the literature. This work attempts to compare hydrogen and carbon monoxide sensing characteristics, namely gas response, response time, recovery time of plasma sprayed tin dioxide thick film with tin dioxide bulk sensor. Gas response in the presence of hydrogen gas (23–81%) was superior to that of carbon monoxide gas (19–79%). An attempt was made to understand plausible reason behind superior hydrogen gas response. Thus, gas response as a function of temperature was simulated using a gas diffusion equation for hydrogen and carbon monoxide gases. Estimated parameters, namely, activation energy of transduction and first order kinetics were correlated with sensor microstructure and experimental gas response values. For hydrogen sensing, shorter response time (30–138 s) and recovery time (118–161 s) of thick film as compared to response time (64–234 s) and recovery time (183–196 s) of bulk sensor was correlated with microstructure of sensory elements. It was observed that tin dioxide thick film, owing to its porous morphology with small-sized particulates exhibited superior hydrogen gas response, short response time and recovery time as compared to its bulk counterpart. 相似文献
95.
To yield stable base resistance and reproducible sensing characteristics, thin film based sensors are considered superior than particulate Taguchi type sensor. The sensing characteristics of ferrite based thin film sensor have hardly been reported in literature. In the present work, the hydrogen sensing characteristics of magnesium zinc ferrite thin film sensor is reported by varying the film thickness, test gas concentration and sensor operating temperature. These thin films were deposited on alumina substrate by sol–gel spin coating route. X-ray diffraction analyses and electron microscopy images of the thin film confirm the nano-crystalline nature of these films. It is reported that the film thickness plays a major role to control the gas sensing characteristics of the deposited films. 相似文献
96.
Successful recapitulation of the anatomical microarchitecture and biomechanics of the native articular cartilage under in vitro culture conditions is still an elusive topic of research. The major roadblock lies in maintaining the stable chondrogenic phenotype in vivo or under long-term in vitro conditions. Tissue engineers worldwide has coined this aberrant loss of permanent cartilage characteristics to transient cartilage form as “chondrocyte hypertrophy”. Although the following has been validated through the expression of a few known markers but very little is understood regarding the molecular mechanism that dwells underneath. This review summarizes the precise aetiology behind the development and progression of the hypertrophic phenotype in chondrocytes under in vitro chondrogenic conditions. Based on the current literature survey, it is deciphered that the type of cell utilized (chondrocytes or stem cells), the chondrogenic culture conditions (growth factors/biochemical mediators) and the culture microenvironment (oxygen tension, mechanical loading) during chondrogenesis have a direct correlation with the dysregulated activity of the chondrogenic signaling pathways corroborating the onset of hypertrophic maturation of chondrocytes. Furthermore, it is critically analyzed whether to completely inhibit these hypertrophy-inducing signaling pathways or apply a brake in terms of time-dependent dose due to their functional duality role in chondrogenesis. 相似文献
97.
Das Bidyut Majumder Mukta Phadikar Santanu Sekh Arif Ahmed 《Multimedia Tools and Applications》2021,80(21-23):31907-31925
Multimedia Tools and Applications - Multiple-choice questions (MCQs) are used as instrumental tool for assessment, not only in various competitive examinations but also in contemporary information... 相似文献
98.
Neural Computing and Applications - A new hybrid model combining the kernel functions along with the random vector functional link neural network (RVFLN) is proposed in this paper for an effective... 相似文献
99.
Ritwik Majumder Manjula DewadasaArindam Ghosh Gerard LedwichFiruz Zare 《Electric Power Systems Research》2011,81(7):1424-1435
This paper discusses the control and protection of a microgrid that is connected to utility through back-to-back converters. The back-to-back converter connection facilitates bidirectional power flow between the utility and the microgrid. These converters can operate in two different modes-one in which a fixed amount of power is drawn from the utility and the other in which the microgrid power shortfall is supplied by the utility. In the case of a fault in the utility or microgrid side, the protection system should act not only to clear the fault but also to block the back-to-back converters such that its dc bus voltage does not fall during fault. Furthermore, a converter internal mechanism prevents it from supplying high current during a fault and this complicates the operation of a protection system. To overcome this, an admittance based relay scheme is proposed, which has an inverse time characteristic based on measured admittance of the line. The proposed protection and control schemes are able to ensure reliable operation of the microgrid. 相似文献
100.
S. B. Majumder D. C. Agrawal Y. N. Mohapatra V. N. Kulkarni 《Integrated ferroelectrics》2013,141(3-4):271-284
Abstract Thin films of lead zirconate titanate having the composition Pb1.05(Zr0.53Ti0.47)O3 were deposited by a solgel method on a set of crystalline and amorphous substrates. The thickness of the film was varied by controlling the sol concentration or by repeated coatings. Factors controlling phase formation in the films such as nature of the substrate material, film thickness, chemical composition of the film, heating rate and gaseous atmosphere during the heat treatment were studied. On glass substrates the pyrochlore phase was obtained in thin (0.4 um) films and the perovskite phase in thicker (>1.5 um) films. Crystalline substrates (except Si and stainless steel) yielded a perovskite phase in 0.6 um thick film. Low Zr/Ti ratio, rapid heating and introduction of nitrogen in the later stage of heat treatment also favoured the formation of the perovskite phase. It is shown that Pb deficiency in the film caused by diffusion of Pb into amorphous substrates or by other mechanisms is primarily responsible for inhibiting the pyrochlore to perovskite transformation. The initial crystallisation of the amorphous film into pyrochlore rather than a perovskite phase (as in powders) is proposed to be due to higher strain energy barrier which exists for the amorphous to perovskite transformation in the film. 相似文献