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排序方式: 共有103条查询结果,搜索用时 15 毫秒
1.
Andres T Aguayo Ana G Gayubo Ana M Tarrío Alaitz Atutxa Javier Bilbao 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2002,77(2):211-216
With the aim of determining the possibilities of directly upgrading the liquid obtained from carbohydrate fermentation, the effect of operating conditions (temperature, space time, water content in the feed) has been studied in the catalytic transformation of aqueous ethanol into hydrocarbons on an HZSM‐5 zeolite in an isothermal fixed bed reactor. Special attention has been paid to the effect of water content on the yield, product distribution and catalyst deactivation. Although deactivation by coke decreases as the water content is increased, this content must be limited at 450 °C and higher temperatures in order to avoid irreversible deactivation of the catalyst by dealumination. © 2002 Society of Chemical Industry 相似文献
2.
Camila Reyes Estefanía Nova-Lamperti Daniel Duran-Sandoval Daniela Rojas Jorge Gajardo Enrique Guzman-Gutierrez Camila Bustos-Ruiz Valeska Ormazbal Felipe A. Zúiga Carlos Escudero Claudio Aguayo 《International journal of molecular sciences》2022,23(13)
Oxidized low-density lipoprotein (ox-LDL) is the most harmful form of cholesterol associated with vascular atherosclerosis and hepatic injury, mainly due to inflammatory cell infiltration and subsequent severe tissue injury. Lox-1 is the central ox-LDL receptor expressed in endothelial and immune cells, its activation regulating inflammatory cytokines and chemotactic factor secretion. Recently, a Lox-1 truncated protein isoform lacking the ox-LDL binding domain named LOXIN has been described. We have previously shown that LOXIN overexpression blocked Lox-1-mediated ox-LDL internalization in human endothelial progenitor cells in vitro. However, the functional role of LOXIN in targeting inflammation or tissue injury in vivo remains unknown. In this study, we investigate whether LOXIN modulated the expression of Lox-1 and reduced the inflammatory response in a high-fat-diet mice model. Results indicate that human LOXIN blocks Lox-1 mediated uptake of ox-LDL in H4-II-E-C3 cells. Furthermore, in vivo experiments showed that overexpression of LOXIN reduced both fatty streak lesions in the aorta and inflammation and fibrosis in the liver. These findings were associated with the down-regulation of Lox-1 in endothelial cells. Then, LOXIN prevents hepatic and aortic tissue damage in vivo associated with reduced Lox-1 expression in endothelial cells. We encourage future research to understand better the underlying molecular mechanisms and potential therapeutic use of LOXIN. 相似文献
3.
Deficit irrigation strategies enhance health‐promoting compounds through the intensification of specific enzymes in early peaches 下载免费PDF全文
4.
Aguayo David; Herman Keith; Ojeda Lizette; Flores Lisa Y. 《Canadian Metallurgical Quarterly》2011,4(2):79
In hopes of promoting college success among Mexican Americans, researchers have identified factors related to their academic performance. A gap in the literature exists between the interactive role of acculturation, enculturation, and generation status in predicting college self-efficacy and college performance (grade-point average, or GPA). To fill this void, this study investigated the relation of demographic variables (e.g., age, gender, socioeconomic status) and cultural variables (e.g., acculturation, enculturation, generation status) on academic outcomes (e.g., college self-efficacy, college performance) among 408 Mexican-American college students. Results of a series of hierarchical regression analyses indicated socioeconomic status, generation status, enculturation, and acculturation had significant positive effects on college self-efficacy; socioeconomic status and the interaction of higher enculturation and first-generation status were positively and significantly related to GPA. Post-hoc analyses indicated college self-efficacy predicted college performance for students who were second generation and beyond. Implications for research and practice are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
5.
Valeska Ormazabal Estefanía Nova-Lampeti Daniela Rojas Felipe A. Zúiga Carlos Escudero Paola Lagos Alexa Moreno Yanara Pavez Camila Reyes Milly Yez Mabel Vidal Guillermo Cabrera-Vives Katherine Oporto Claudio Aguayo 《International journal of molecular sciences》2022,23(2)
Tissue regeneration is often impaired in patients with metabolic disorders such as diabetes mellitus and obesity, exhibiting reduced wound repair and limited regeneration capacity. We and others have demonstrated that wound healing under normal metabolic conditions is potentiated by the secretome of human endothelial cell-differentiated mesenchymal stem cells (hMSC-EC). However, it is unknown whether this effect is sustained under hyperglycemic conditions. In this study, the wound healing effect of secretomes from undifferentiated human mesenchymal stem cells (hMSC) and hMSC-EC in a type-2 diabetes mouse model was analyzed. hMSC were isolated from human Wharton’s jelly and differentiated into hMSC-EC. hMSC and hMSC-EC secretomes were analyzed and their wound healing capacity in C57Bl/6J mice fed with control (CD) or high fat diet (HFD) was evaluated. Our results showed that hMSC-EC secretome enhanced endothelial cell proliferation and wound healing in vivo when compared with hMSC secretome. Five soluble proteins (angiopoietin-1, angiopoietin-2, Factor de crecimiento fibroblástico, Matrix metallopeptidase 9, and Vascular Endothelial Growth Factor) were enriched in hMSC-EC secretome in comparison to hMSC secretome. Thus, the five recombinant proteins were mixed, and their pro-healing property was evaluated in vitro and in vivo. Functional analysis demonstrated that a cocktail of these proteins enhanced the wound healing process similar to hMSC-EC secretome in HFD mice. Overall, our results show that hMSC-EC secretome or a combination of specific proteins enriched in the hMSC-EC secretome enhanced wound healing process under hyperglycemic conditions. 相似文献
6.
Continuous laboratory solvent extraction of gold from cyanide solutions has been investigated by using LIX 79 guanidine‐based extractant. Different variables that affected the extraction included aqueous pH, extractant concentration and modifier concentration. Extraction isotherms of the aurocyanide complex with respect to the other cyanoanions were compared, and the following order of selectivity was observed: Au > Ag > Cu > Zn > Fe. According to the pH isotherms, aurocyanide can be extracted in alkaline media, and a better separation with respect to other cyano anions was obtained in the pH range 10.5–11.2. From the McCabe‐Thiele diagrams, better recovery was observed when using LIX 79 and tridecanol at 10 vol.‐%. Stripping gold from the loaded organic was carried out at pH > 12 by using NaOH and NaCN solutions. The pilot plant tests indicate that a two‐stage extraction followed by one strip step are more than adequate to obtain an overall process efficiency of 92 %. However, for those cases where copper is present significantly, a copper wash stage is recommended before gold stripping. In this case, stripping of copper is accomplished at a pH 10.8, whereas the gold stripping was done at a pH of 12.0. 相似文献
7.
A kinetic model for simulation of the MTO process over SAPO-18 catalyst in a wide range of operating conditions has been proposed. The kinetic model predicts the experimental evolution of reaction products with time on stream, which follows three consecutive periods: initiation (where olefin production increases), a period of maximum olefin production and a period in which this production decreases. The kinetic scheme takes into account these three steps that evolve with time on stream: formation of active intermediate compounds, an step where olefins are formed by reaction of oxygenates (methanol/DME) with these intermediates and deactivation of intermediates by degradation to coke. The presence of water in the reaction medium attenuates the reaction rate of these steps. Discrimination of kinetic equations and calculation of the parameters of best fit have been carried out by solving the mass conservation equations of the individual components of the kinetic scheme together with the kinetic equation for deactivation and taking into account the effect of water on the kinetics of each step. 相似文献
8.
The N-terminal region of human cystatin C has been shown to be of crucial importance for the interaction of the inhibitor with cysteine proteinases. However, several studies have been unable to identify the corresponding region in bovine cystatin C, indicating that the binding of proteinases to the bovine inhibitor may not be dependent on this region. With the aim to resolve this apparent discrepancy and to elucidate the relation of bovine cystatin C to other cystatins, we have isolated a cDNA clone encoding bovine precystatin C. The sequence of this cDNA was similar to that of the human inhibitor and showed a putative signal peptidase cleavage site consistent with the N-terminal regions of the bovine and human inhibitors being of comparable size. This suggestion was verified by determination of the relative molecular mass of the mature bovine inhibitor isolated from cerebrospinal fluid under conditions minimising proteolysis. The N-terminal of the purified inhibitor was blocked, but the sequence of the N-terminal peptide produced by digestion with endopeptidase LysC could be unequivocally determined by tandem mass spectroscopy. Together, these results show that bovine cystatin C has 118 residues, in contrast with 110-112 residues reported previously, and has an N-terminal region analogous to that of human cystatin C. This region presumably is of similar importance for tight binding of target proteinases as in the human inhibitor. 相似文献
9.
10.
Aguayo VM Baker SK Crespin X Hamani H MamadoulTaïbou A 《Food and nutrition bulletin》2005,26(1):26-31
In 1997, the reduction of child mortality became a policy priority for the Government of Niger because Niger's child mortality rate was the highest in the world. The Ministry of Public Health, Helen Keller International (HKI), and UNICEF spearheaded a coalition-building process linking vitamin A deficiency (VAD) control to national child survival goals. An evidence-based advocacy strategy was developed around the child survival benefits of adequate and sustained VAD control with one unambiguous message: "VAD control can avert over 25,000 child deaths per year." As a result, in 1997 Niger became one of the first countries in Africa to effectively integrate vitamin A supplementation into National Immunization Days (NIDs) for polio eradication. The challenge was then to provide children with a second annual dose of vitamin A. This led in 1999 to the first ever National Micronutrient Days (NMDs) in Africa. NMDs are mobilization campaigns in which caregivers are actively encouraged to take their children for the delivery of vitamin A supplements. Since 1999, the combination of NIDs and NMDs has ensured that over 80% of children 6 to 59 months of age receive two vitamin A doses annually. The success of NIDs/NMDs has relied on five pillars: leadership and ownership by the Ministry of Public Health; district-level planning and implementation; effective training and flexible delivery mechanisms; effective social information, communication, and mobilization; and responsiveness and flexibility of Ministry of Public Health and development partners. This successful approach has been widely disseminated, notably through the West African Nutrition Focal Points Network. 相似文献