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排序方式: 共有631条查询结果,搜索用时 0 毫秒
31.
Agata Campisi Giuseppina Raciti Giovanni Sposito Rosaria Grasso Maria A. Chiacchio Michela Spatuzza Alessandro Attanzio Ugo Chiacchio Luisa Tesoriere Mario Allegra Rosalia Pellitteri 《International journal of molecular sciences》2021,22(7)
Herein, we assessed the effect of full native peptide of amyloid-beta (Aβ) (1-42) and its fragments (25-35 and 35-25) on tissue transglutaminase (TG2) and its isoforms (TG2-Long and TG2-Short) expression levels on olfactory ensheathing cells (OECs). Vimentin and glial fibrillary acid protein (GFAP) were also studied. The effect of the pre-treatment with indicaxanthin from Opuntia ficus-indica fruit on TG2 expression levels and its isoforms, cell viability, total reactive oxygen species (ROS), superoxide anion (O2−), and apoptotic pathway activation was assessed. The levels of Nestin and cyclin D1 were also evaluated. Our findings highlight that OECs exposure to Aβ(1-42) and its fragments induced an increase in TG2 expression levels and a different expression pattern of its isoforms. Indicaxanthin pre-treatment reduced TG2 overexpression, modulating the expression of TG2 isoforms. It reduced total ROS and O2− production, GFAP and Vimentin levels, inhibiting apoptotic pathway activation. It also induced an increase in the Nestin and cyclin D1 expression levels. Our data demonstrated that indicaxanthin pre-treatment stimulated OECs self-renewal through the reparative activity played by TG2. They also suggest that Aβ might modify TG2 conformation in OECs and that indicaxanthin pre-treatment might modulate TG2 conformation, stimulating neural regeneration in Alzheimer’s disease. 相似文献
32.
The modern fruit juice industry needs their products to be characterized by high-quality attributes to meet consumers’ expectation. In this view, the composition of 26 Italian commercial apricot juices obtained from organic, integrated and conventional agriculture was analysed for carbohydrates, organic acids, amino acids, phenolic compounds and furanic compounds by high-performance liquid chromatography (HPLC). The content of 5-hydroxymethylfurfural in apricot juices (range 0.1–18 mg/l) was within the regulatory limit of 20 mg/l. The lack of furanic compounds in apricot fresh fruits confirmed their importance as quality markers of heating condition during processing and storage of fruit juices. Univariate analysis disclosed some significant differences among the composition of the apricot juices in terms of glucose, fructose, malic acid, glycine, chlorogenic acid, rutin, and a∗-parameter (redness). Principal component analysis on chemical composition of apricot juices resulted in two principal components (PCs) that accounted for 66% of the total variance. Organic apricot juices showed some separation from the other juices, whereas a lack of distinction between integrated and conventional juices appeared. 相似文献
33.
Didier Dupont Giuseppina Mandalari Daniel Molle Julien Jardin Joëlle Léonil Richard M. Faulks Martin S. J. Wickham E. N. Clare Mills Alan R. Mackie 《Molecular nutrition & food research》2010,54(6):767-780
IgE‐mediated allergy to milk and egg is widespread in industrialised countries and mainly affects infants and young children. It may be connected to an incomplete digestion of dietary proteins causing an inappropriate immune response in the gut. In order to study this, a biochemical model of infant gastroduodenal digestion has been developed, which has reduced levels of protease (eightfold for pepsin and tenfold for trypsin and chymotrypsin), phosphatidylcholine and bile salts, compared with the adult model. This model has been used to study the behaviour of three characterised food‐relevant proteins (bovine β‐lactoglobulin (β‐Lg), β‐casein (β‐CN) and hen's egg ovalbumin), all of which are relevant cows' milk and hens' egg allergens. Digestion products were characterised using electrophoresis, immunochemical techniques and MS. These showed that ovalbumin and β‐CN were digested more slowly using the infant model compared with the adult conditions. Resistant fragments of β‐CN were found in the infant model, which correspond to previously identified IgE epitopes. Surprisingly, β‐Lg was more extensively degraded in the infant model compared with the adult one. This difference was attributed to the tenfold reduction in phosphatidylcholine concentration in the infant model limiting the protective effect of this phospholipid on β‐Lg digestion. 相似文献
34.
Andrea Versari Giuseppina Paola Parpinello Arianna Ricci Matteo Meglioli 《Food Analytical Methods》2013,6(6):1697-1703
In this study, 200 samples of traditional balsamic vinegar (TBV) of Reggio-Emilia, a typical Italian “aged dressing” with Protected Denomination of Origin, were analyzed to model the relationship between sensory scores with some pre-selected compounds/parameters, such as Brix value, water activity (a w), titratable acidity, color, polymeric compounds, and electronic nose signal. Statistical techniques, such as nonlinear regression and Principal Component Analysis (PCA) were used to model the relationship among vinegars composition. The sensory score of panelists was mainly correlated with Brix (r?=?0.85) followed by brown color at 445 nm (r?=?0.74) and water activity (a w) (r?=??0.79), whereas the polymeric compounds content showed a negative correlation with water activity (r?=?–0.73). In particular, the water activity of TBVs at different Brix values followed a nonlinear trend with good fitting (r?=?0.857) with K?=?3.10 that was consistent with the value reported in the literature for fructose and glucose. Electronic nose (enose) data from TBVs and six marker compounds (acetic acid, butyric acid, vanillin, ethyl-phenylacetate, phenylethyl alcohol, and furfural) combined with PCA revealed a pattern related to the ageing of TBVs. 相似文献
35.
Cold plates, devices used for the thermal management of electronic equipment, consist of a fluid flow space that is bounded by metallic walls. The fluid passages are designed to optimize the heat extraction from the electronics. This paper deals with the fluid flow and heat transfer in cold plates in which both the fluid flow and heat transfer experience periodic variations in the streamwise direction. The motivation for the work was to devise a methodology for dealing with problems that are highly complex and also computationally demanding. The first goal of the work was to transform the combined problems of fluid flow and conjugate heat transfer into one in which the wall heat transfer can be solved separately. The decoupling was achieved by first focusing on the solution of the full conjugate heat transfer problem for a portion of the periodic array. From this solution, heat transfer coefficients were extracted and subsequently employed for the solution of the wall heat conduction problem for the entire cold plate. The second focus was the development of enhancements of the heat transfer performance of cold plates. Consideration was given to manufacturing as well as thermal and fluid flow issues. 相似文献
36.
In this article, a synergistic approach encompassing numerical simulation and laboratory experimentation is used to identify the optimal geometry for the creation of fine fiber by the melt-blown process. The problem involves highly complex fluid flow and convective heat transfer. The fine fiber is created by the use of high-velocity, obliquely impinging air jets that stretch a polymer extrudate in the partially fluid state. High-temperature air is used to maintain the fluidity of the polymeric material as it exits the die. Four different geometrical configurations were investigated with regard to their capability of producing high fluid shear and high temperatures in the critical region just downstream of the emergence of the polymer extrudate from the tip of a die. The results of the numerical simulations provided a definitive conclusion about the relative efficacies of the four investigated geometrical configurations. The velocity and temperature profiles of the oblique jets were carefully documented to identify their decay with increasing downstream distance from the die tip. Velocity profile measurements were in excellent agreement with the numerical predictions, thereby validating the simulation model. Another major parameter of the study, in addition to the geometric-configuration issue, was the pressure difference responsible for setting the magnitude of the jet velocity. The accuracy of the results was established by a mesh independence study and by varying the size of the solution domain. 相似文献
37.
Ephraim Nissan 《AI & Society》2000,14(3-4):411-439
Sometimes, technological solutions to practical problems are devised that conspicuously take into account the constraints to which a given culture is subjecting the particular task or the manner in which it is carried out. The culture may be a professional culture (e.g., the practice of law), or an ethnic-cum-professional culture (e.g., dance in given ethnic cultures from South-East Asia), or, again, a denominational culture prescribing an orthopraxy impinging on everyday life through, for example, prescribed abstinence from given categories of workday activities, or dietary laws. Massimo Negrotti'sTheory of the artificial is a convenient framework for discussing some of these techniques. We discuss a few examples, but focus on the contrast of two that are taken from the same cultural background, namely, technological applications in compliance with Jewish Law orthopraxy. . Soya-, mycoprotein- or otherwise derived meat surrogates are an example ofnaturoid; they emulate the flavours and olfactory properties, as well as the texture and the outer and inner appearance, of the meat product (its kind, cut, form) they set out to emulate (including amenability to cooking in the usual manner for the model), while satisfying cultural dietary prohibitions. . In contrast, the Sabbath Notebook, a writing surrogate we describe in this paper, is atechnoid: it emulates a technique (writing to store alphanumeric information), while satisfying the prohibition of writing at particular times of the liturgical calendar (the Sabbath and the major holidays). 相似文献
38.
Ephraim Nissan 《Expert systems with applications》1998,14(4):443-460
The consecutive, partly overlapping emergence of expert systems and then neural computation methods among intelligent technologies, is reflected in the evolving scene of their application to nuclear engineering. This paper provides a bird's eye view of the state of the application in the domain, along with a review of a particular task, the one perhaps economically more important: refueling design in nuclear power reactors. 相似文献
39.
The electrostatic potential above the 100 surface plane of a f.c.c. ionic crystal has been calculated using a point charge distribution for the positive nuclei and a continuous charge density distribution for electrons. The continuous electron charge distribution has been obtained from the known results of a Fourier crystal structure analysis. The results for the electric field and its different gradients are compared with those obtained from the Lennard-Jones and Dent model (point charge distributions for both the positive and negative ions). It has been found that the two models lead to significant differences of the electrostatic potentials and their derivatives. 相似文献
40.
The binary phase diagram of the SrF2-MgF2 system below 1200°C has been constructed from DTA cooling data. The system shows an eutectic at 48.4 mole % MgF2 and 871°C, and a peritectic at 50 mole % and 880°C, corresponding to the compound SrMgF4, previously prepared here by solid state reaction. A solid-solid transition in SrMgF4 occurs at about 809°C. Small single crystals of SrMgF4 were obtained by extremely slow cooling of a stoichiometric melt. 相似文献