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排序方式: 共有438条查询结果,搜索用时 15 毫秒
71.
Konstantinos Stamatopoulos Evangelos Katsoyannos Arhontoula Chatzilazarou Spyros J. Konteles 《Food chemistry》2012
Impact of steam, hot water blanching and UV-C irradiation as pre-treatments on extraction of oleuropein and related biophenols from olive leaves (OLs), was investigated. Moreover, particle size effect of olive leaves and steam blanching duration were selected as independent variables to optimise steam blanching process in terms of oleuropein content (OC) and antioxidant activity (AC) of ethanolic extracts, by using response surface methodology. Optimum conditions for OC and AC were 10 min steam blanching of 20–11 and 3–1 mm olive leaf fraction, respectively. Depending on the extraction procedure, at optimum conditions of steaming the results indicate that steam blanching of OL prior to extraction can significantly increase oleuropein yield from 25 to 35 times compared to non-steam blanched sample, whereas the antioxidant activity increased from 4 to 13 times. No significant UV-C effect was observed in OC and AC, while hot water blanched samples showed significantly higher oleuropein yields and antioxidant activity compared to untreated samples. 相似文献
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Meta-analysis (MA) is a statistical methodology that combines the results of several independent studies considered by the analyst to be 'combinable'. The simplest approach, the fixed-effects (FE) model, assumes the true effect to be the same in all studies, while the random-effects (RE) family of models allows the true effect to vary across studies. However, all methods are only correct asymptotically, while some RE models assume that the true effects are normally distributed. In practice, MA methods are frequently applied when study numbers are small and the normality of the effect distribution unknown or unlikely. In this article, we discuss the performance of the FE approach and seven frequentist RE MA methods: DerSimonian-Laird, Q-based, maximum likelihood, profile likelihood, Biggerstaff-Tweedie, Sidik-Jonkman and Follmann-Proschan. We covered numerous scenarios by varying the MA sizes (small to moderate), the degree of heterogeneity (zero to very large) and the distribution of the effect sizes (normal, skew-normal and 'extremely' non-normal). Performance was evaluated in terms of coverage (Type I error), power (Type II error) and overall effect estimation (accuracy of point estimates and error intervals). 相似文献
74.
Panagiotis Sarantis Alexandros Bokas Adriana Papadimitropoulou Evangelos Koustas Stamatios Theocharis Pavlos Papakotoulas Dimitrios Schizas Alexandros Papalampros Evangelos Felekouras Athanasios G. Papavassiliou Michalis V. Karamouzis 《International journal of molecular sciences》2021,22(13)
Pancreatic Cancer (PC) is recognized as a highly thrombogenic tumor; thus, low-molecular-weight heparin (LMWH) such as tinzaparin is routinely used for PC patients. On the basis of combinatorial therapy approaches to treat highly malignant and refractory cancers such as PC, we hypothesized that tinzaparin can augment the effectiveness of traditional chemotherapeutic drugs and induce efficient antitumor activity. PANC-1 and MIAPaCa-2 were incubated alone or in combination with tinzaparin, nab-paclitaxel and gemcitabine. In vivo evaluation of these compounds was performed in a NOD/SCID mouse using a model injected with PANC-1. Tinzaparin enhances the anti-tumor effects of nab-paclitaxel and gemcitabine in mtKRAS PC cell lines via apoptosis in in vitro experiments. The triple combination power acts through the induction of apoptosis, reduction of the proliferative potential and angiogenesis; hence, contributing to a decrease in tumor volume observed in vivo. The triple regimen provided an extra 24.3% tumor reduction compared to the double combination (gemcitabine plus nab-paclitaxel). Combinatorial strategies can create novel therapeutic approaches for the treatment of patients with PC, achieving a better clinical outcome and prolonged survival. Further prospective randomized research is needed and the investigation of various concentrations of tinzaparin above 150 UI/Kg, would potentially provide a valuable synergistic effect to the conventional therapeutic compounds. 相似文献
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ABSTRACT Simulation results for convective drying processes in cross-flow packed bed grain dryers are discussed in this article. A mathematical model developed in order to enable easier design of convective dryers and optimization of operating conditions for agricultural materials (wheat, corn, sunflower seed, etc.) is used in the study. On the basis of calculated values of the state variables of the gas phase and the solids, a clear image of the process itself can be obtained, as well as an overview of advantages and disadvantages of a specific design, supporting and facilitating decisions about the choice of dryer type and operating scheme. The case of double passing of drying agent, with and without additional heating, for a cross-flow continuous dryer, as well as the case of different materials processed in a series of cross-flow batch dryers, is analyzed. 相似文献
77.
Theodosios D. Filippatos Evangelos C. Rizos Vasilios Tsimihodimos Irene F. Gazi Alexandros D. Tselepis Moses S. Elisaf 《Lipids》2013,48(6):547-555
Alterations in high-density lipoprotein (HDL) subclass distribution, as well as in the activities of HDL-associated enzymes, have been associated with increased cardiovascular disease (CVD) risk. HDL subclass distribution and the activities of HDL-associated enzymes remain unknown in prediabetic patients, a condition also associated with increased CVD risk. The aim of the present study was to assess any differences in HDL subclass distribution (using polyacrylamide gel electrophoresis) and in activities of HDL-associated enzymes between prediabetic (impaired fasting glucose, IFG, n = 80) and non-prediabetic subjects (n = 105). Subjects with prediabetes had significantly increased waist circumference, blood pressure and triacylglycerol (TAG) levels compared with subjects with fasting glucose levels <100 mg/dL (all p < 0.05). The proportion of small HDL3 over HDL cholesterol (HDL-C) was significantly increased in prediabetic subjects compared with their controls (p < 0.05). The activity of the anti-atherogenic HDL-associated lipoprotein-associated phospholipase A2 (HDL-LpPLA2) was significantly lower in subjects with prediabetes (p < 0.05), whereas the activity of paraoxonase 1 (using both paraoxon and phenyl acetate as substrates) did not significantly differ between subjects with or without prediabetes. In a stepwise linear regression analysis, the proportion of small HDL3 over HDL-C concentration was independently associated with the presence of prediabetes and with total cholesterol and TAG concentration (positively), as well as with HDL-C levels (negatively). We also observed a trend of increased small dense low-density lipoprotein cholesterol levels in prediabetic subjects compared with their controls. Subjects with IFG exhibit increased proportion of small HDL3 particles combined with decreased activity of the anti-atherogenic HDL-LpPLA2. 相似文献
78.
Timothy J. Crowley Edward S. Meadows Evangelos Kostoulas Francis J. Doyle III 《Journal of Process Control》2000,10(5)
This work addresses the computation of surfactant feed profiles for shaping a particle size distribution to a bimodal target distribution. A fundamental population balance model of styrene semibatch emulsion polymerization is used in this control study. Both surfactant feed rate and free surfactant concentration are considered as alternative control variables and a comparison is made of the two approaches. A comparison is also made of several different objective function norms in the optimization. Results suggest that a min–max norm, tied to the distribution modes, is the most appropriate metric. 相似文献
79.
Moduli of the 2n and 2n ± 1 forms are usually employed in designs that adopt the residue number system. However, in several cases such as in finite impulse response filters and communication components, a modulo value equal to 2n ? 2 can be used. So far, modulo 2n ? 2 arithmetic units have been based either on look-up tables or on generic modulo arithmetic units. In this work, by taking advantage of the properties of modulo 2n ? 2 arithmetic, we propose efficient modulo 2n ? 2 multi-operand adder, multiplier as well as squarer architectures. The proposed circuits are based on the corresponding ones for modulo 2n?1 ? 1 arithmetic and some simple logic. Experimental results validate that the proposed circuits achieve significant area and delay savings compared to those previously presented. 相似文献
80.