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251.
AbstractEffective extraction of phyto-biomolecules insures retaining maximum functionality along with higher recovery. In this study, ultrasound-solvent assisted extraction (USAE) was employed for optimal extraction of phyto-biomolecules from Sesamum indicum (sesame) leaves using the approach of Response Surface Methodology (RSM). The optimized condition of 200?W power, 59% methanol concentration with 1:14?g/mL solid–liquid ratio and 15?min of extraction time yielded 367.39?±?1.85?mg GAE/100?g of total phenolic content, 96.72?±?3.27% of free radical scavenging activity and 81.20?±?2.87% of iron chelating activity respectively. The extract consist of essential phytocomponents like gallic acid, chlorogenic acid, and quercetin with lipid peroxidation activities of >50% over incubation time of 48?h. Also, showed antimicrobial activity against various Gram’s negative and positive food borne pathogens. The results of this study implied the importance of USAE for effective and optimum recovery of phyto-biomolecules from Sesame leaves with retained functional properties. 相似文献
252.
Hepatocellular carcinoma (HCC) is the major histological form of primary liver cancer. It has usually reached the disease state once the patient is diagnosed since there are no specific symptoms in the early stages of HCC. This fact increases the difficulty of curing HCC. Recently, quantities of evidence have shown that many mathematical methods (such as dynamic network biomarkers, DNB) can be used to detect critical states or tipping points of complex diseases. However, it is difficult to apply the DNB theory to the clinic since multiple samples are generally unavailable for individual patient. This paper constructs a novel method based on landscape dynamic network biomarkers (L-DNB), which aims to detect early warning signals from cirrhosis state to very advanced HCC state in individual patient. The selected dataset contains multiple samples for each HCC state. A score that indicates the disease characteristics is calculated for each sample by RNA-seq data, and several scores constitute a distribution in the same state. Quantifying the statistical characteristics of these distributions and determining that low-grade dysplastic and high-grade dysplastic are the critical states of HCC. These results can provide scientific advice for early warning indicators and optimal treatment time for HCC. 相似文献
253.
Kun‐ze Du Jin Li Lanhui Wang Jia Hao Xue‐jing Yang Xiu‐mei Gao Yan‐xu Chang 《Journal of separation science》2020,43(4):799-807
Hydrosoluble trehalose lipid (a biosurfactant) was employed for the first time as a green extraction solution to extract the main antioxidant compounds (geniposidic acid, chlorogenic acid, caffeic acid, and rutin) from functional plant tea (Eucommia ulmoides leaves). Single‐factor tests and response surface methodology were employed to optimize the extraction conditions for ultrasound‐assisted micellar extraction combined with ultra‐high‐performance liquid chromatography in succession. A Box‐Behnken design (three‐level, three‐factorial) was used to determine the effects of extraction solvent concentration (1–5 mg/mL), extraction solvent volume (5–15 mL), and extraction time (20–40 min) at a uniform ultrasonic power and temperature. In consequence, the best analyte extraction yields could be attained when the trehalose lipid solution concentration was prepared at 3 mg/mL, the trehalose lipid solution volume was 10 mL and the extraction time was set to 35 min. In addition, the recoveries of the antioxidants from Eucommia ulmoides leaves analyzed by this analytical method ranged from 98.2 to 102%. These results indicated that biosurfactant‐enhanced ultrasound‐assisted micellar extraction coupled with a simple ultra‐high‐performance liquid chromatography method could be effectively applied in the extraction and analysis of antioxidants from Eucommia ulmoides leaf samples. 相似文献
254.
Yu‐an Sun Hengmao Zhang Zhenxing Li Wenhao Yu Zhijun Zhao Ke Wang Meili Zhang Jinting Wang 《Journal of separation science》2020,43(7):1284-1296
Agarwood, a species of resinous heartwood, is a precious medicinal plant and a type of rare natural spice, which is widely used in medicine, cosmetics, religious activities, and other fields. In this study, agarwood samples from eight different regions across four countries were analyzed by comprehensive two‐dimensional gas chromatography?quadrupole time‐of‐flight mass spectrometry. A total of 232 species were identified (the match factors of these compounds were above 750). The main compounds of agarwood are oxygenated sesquiterpenes and chromones. The compositions of India1 and Malaysia2 were significantly different from those of other samples, which might be attributed to the different production processes of agarwood. For further investigation, factor analysis was conducted for six agarwood samples. The results showed that the data classification possessed a regional characteristic; according to the retention time and relative content, characteristic compositions were determined by factor scores. Finally, the differences of characteristic compositions were simply analyzed, and the reasons were speculated. 相似文献
255.
Several structural series of unsaturated polyester networks which had different isophthalic acid–maleic anhydride ratios or different precentage rates of styrene incorporated in the network were studied by means of thermomechanical tests. It was demonstrated that the transition zone (α and β) did not correspond specifically to a polytyrene phase but could be linked to the presence of microdomains of different structures within the polyester network. It is the successive setting in motion of these microdomains, under the effect of a rise in temperature, which creates a broad transition zone. Structural chain formations based on the resin components (prepolymer and styrene) were proposed and linked to the transition temperatures detected. The improved knowledge of the structure and the various microdomains present within the networks will provide a better apprehension of the hydrolytic stability of unsaturated polyester materials. 相似文献
256.
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258.
Beddington-DeAngelis型捕食-食饵动力系统的正平衡点及其稳定性 总被引:1,自引:0,他引:1
肖海滨 《高校应用数学学报(英文版)》2006,21(4)
A class of Beddington-DeAngelis' type predator-prey dynamic system with prey and predator both having linear density restriction is considered. By using the qualitative methods of ODE, the existence and uniqueness of positive equilibrium and its global asymptotic stability are analyzed. The direct criterions for local stability of positive equilibrium and existence of limit cycle are also established when inference parameter of predator is small. 相似文献
259.
Henghui Zhang Xiaoli Wang Dongliang He Dongliang Zou Runzhu Zhao Huifang Wang Shuying Li Yongping Xu Buhailiqiemu Abudureheman 《Molecules (Basel, Switzerland)》2022,27(1)
In the present work, the extraction process of total flavonoids (TFs) from X. sorbifolia flowers by ultrasound-assisted extraction was optimized under the response surface methodology (RSM) on the basis of single-factor experiments. The optimal extraction conditions were as follows: ethanol concentration of 80%, solid–liquid ratio of 1:37 (g/mL), temperature of 84 °C, and extraction time of 1 h. Under the optimized conditions, the extraction yield of the TFs was 3.956 ± 0.04%. The radical scavenging capacities of TFs against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) were much greater than that of rutin. The results of antibacterial experiments indicated that the TFs displayed strong inhibitory activities on E. coli, S. aureus and Bacillus subtilis. Therefore, X. sorbifolia flowers can be used as a novel source of natural flavonoids, and the TFs have potential applications as natural antioxidants or antibacterial agents in the food and pharmaceutical industries. 相似文献
260.
阵列波导光栅波分复用/解复用器光谱响应效率的理论模型 总被引:1,自引:0,他引:1
基于单模光波导的本征模场分布,瑞利-索末菲衍射积分公式和天线原理的互易定理,给出耦合器中两个非接触平面光波导耦合特性的描述.基此,根据等光程差不等振幅多光束干涉的光场叠加原理,推导出新颖的阵列波导光栅波分复用/解复用器的光谱响应效率的解析函数表达式,这些表达式可为快速精确分析阵列波导光栅波分复用/解复用器的特性提供理论基础.同时,介绍了一个计算阵列波导光栅波分复用/解复用器特性的例子,给出其光谱响应度和信号通道串扰. 相似文献