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1.
The ability of fermentative CO2 to blow off the volatile compounds that are synthesized during fermentation has been studied. Model solutions simulating a fermenting must were purged at different CO2 flow rates and temperatures, and the amount of volatile compounds blown off by the stream of CO2 was recorded by high-resolution gas chromatography. Data showed that under normal fermenting conditions, fatty acid ethyl esters and some fusel alcohol acetates are blown off the solution at a high rate. The maximum loss rate was observed for ethyl decanoate. The purging speed is doubled when temperature increases from 17 °C to 27 °C. Losses can be interpreted by a linear model and are a function of the compound and the flow rate of CO2. These models allow us to reconstruct the volatile synthesis vs time functions through graphic calculus and to estimate the proportion of volatile material retained, hydrolysed and purged. Synthesis takes place during the tumultuous period of fermentation together with CO2 production that blows off the volatile material. Hydrolysis takes place in the last stages of fermentation. In a 10-1 open fermenter, up to 80% of volatile material can be blown off while an average of 10% is retained. Residual esterase activity accounts for about 20% of the total amount of ester synthesized.  相似文献   
2.
The occurrence of secondary hypogonadism is a common finding in males who seek help with erectile dysfunction, although the relationship to diminished testosterone is unclear. Two possibilities exist regarding both the genesis and maintenance of the hypogonadotropic hypogonadal state. First, a defect in hypothalamic function, resulting in downregulation as well as in alterations of anterior pituitary function; second, estradiol inhibition of gonadotropin release, both of which result in decreased testosterone production. As testosterone levels decrease and estradiol levels increase, the ratio of free testosterone to estradiol reaches a critical point and the estrogenic gonadotropin suppressive effects predominate. This ratio may signal the biological point of no return and could become one of the criteria for defining the separation of the transitional hypogonadal state from the final 'end stage' hypogonadotropic hypogonadal state. As the aging process continues, there is a relative accumulation of fatty tissue, and aromatization accelerates the conversion of testosterone to estradiol. This additional secondary estradiol inhibition results in the maintenance of the testosterone deficient state, and the aging process continues uncontested.  相似文献   
3.
Of the aglycone flavonoids identified in the exudate of cistus ladanifer, two, the flavone apigenin-4-(O)-methyl and the flavonol kaempferol-3,7-di(O)-methyl inhibit development of the seedlings of Rumex crispus at 0.5 and 1 mM. Additive effects were observed between the major flavonols of the exudate kaempferol-3-(O)-methyl and kaempferol-3,7-di-(O)-methyl in inhibiting the size of the cotyledons and delaying the germination and cotyledon emergence. The presence of apigenin-4-(O)-methyl, kaempferol3,7-di-(O)-methyl, and kaempferol-3-(O)-methyl was detected in the soils associated with C. ladanifer during the summer and autumn months. That these compounds are present in the soil and are not restricted to the leaves provides support for the hypothesis that C. ladanifer has allelopathic potential.  相似文献   
4.
The effects of air oxidation of three Spanish coals on the pressure exerted during carbonization have been studied. Coals were oxidized by air in an oven at 120 and 140 °C. The extent of oxidation was assessed by the Audibert-Arnu dilatometer test. Coal samples oxidized at different levels were subjected to the Koppers-lncar laboratory coking pressure test. The results obtained indicated that for coals classified as ‘dangerous’ the ‘danger’ increased and reached a maximum at a certain level of oxidation, after which it decreased sharply. This behaviour did not occur with coals classified as safe.  相似文献   
5.
In today's highly interconnected, uncertain and dynamic business environment, team boundary spanning has become an important determinant of the performance of new product development (NPD) projects. Despite the positive evidence supporting the use of boundary spanning activities by NPD teams, little is still known about how boundary spanning teams become high-performance teams. The current study advances research on this subject by examining the mediating effect of team potency on the relationship between team boundary spanning and new product performance, as well as the moderating effects of team size and functional diversity on the relationship between team boundary spanning and team potency. Data from a time-lagged survey study of 140 NPD projects found that team boundary spanning can promote team potency that, in turn, results in greater new product quality and new product creativity. The positive effect of team boundary spanning on team potency was found to be more pronounced for NPD teams of medium size and high levels of functional diversity.  相似文献   
6.
Z r S e 2 is a band semiconductor studied long time ago. It has interesting electronic properties, and because its layer structure can be intercalated with different atoms to change some of the physical properties. In this investigation, we found that Zr deficiencies alter the semiconducting behavior and the compound can be turned into a superconductor. In this paper, we report our studies related to this discovery. The decreasing of the number of Zr atoms in small proportion according to the formula Zr x Se2, where x is varied from about 8.1 to 8.6 K, changing the semiconducting behavior to a superconductor with transition temperatures ranging between 7.8 and 8.5 K, is depending on the deficiencies. Outside of those ranges, the compound behaves as semiconducting with the properties already known. In our experiments, we found that this new superconductor has only a very small fraction of superconducting material determined by magnetic measurements with applied magnetic field of 10 Oe. Our conclusions is that superconductivity is filamentary. However, in one studied sample, the fraction was about 10.2 %, whereas in others is only about 1% or less. We determined the superconducting characteristics; the critical fieldsthat indicate a type 2 superonductor with Ginzburg-Landau κ parameter of the order about 2.7. The synthesis procedure is quite normal following the conventional solid state reaction. In this paper, included are the electronic characteristics, transition temperature, and evolution with temperature of the critical fields.  相似文献   
7.
The present work describes the process by which the pilot project of clinical management of the Hospital Complex Juan Canalejo, designated as "Heart Area", was implemented. In the first section, the needs and reasons that led to the undertaking of this project are explained. The project's objectives and operative strategies are listed. In the Material and Methods section, three basic aspects of the "Heart Area" are described: selection criteria of the "Area", its structure and function, and its foundation and development. In the Results section, we compare the activity undertaken in the "Area" to the situation present prior to its implementation, in relation to quality and costs. Finally, in the Conclusions, we comment on the important implications that our project can have within the Hospital Complex Juan Canalejo as well as in the health care field in general.  相似文献   
8.
A multi-period discrete facility location problem is introduced for a risk neutral strategy with uncertainty in the costs and some of the requirements along the planning horizon. A compact 0–1 formulation for the Deterministic Equivalent Model of the problem under two alternative strategies for the location decisions is presented. Furthermore, a new algorithmic matheuristic, Fix-and-Relax-Coordination, is introduced. This solution scheme is based on a specialization of the Branch-and-Fix Coordination methodology, which exploits the Nonanticipativity Constraints and uses the Twin Node Family concept. The results of an extensive computational experience allow to compare the alternative modeling strategies and assess the effectiveness of the proposed approach versus the plain use of a state-of-the-art MIP solver.  相似文献   
9.
10.
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   
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