2,035 research outputs found
A Mathematical Model to Evaluate the Kinetics of D-glucose and D-fructose Fermentations by Saccharomyces bayanus at Increasing Ethanol Concentrations
In the cellar, slow and stuck fermentations occurring during winemaking are often successfully solved bythe addition of yeast strains like Saccharomyces bayanus. The kinetic behaviour shown by S. bayanus duringalcoholic fermentation was investigated using a mathematical model previously tested for S. cerevisiae, inorder to show which of the six functional parameters of the model differed significantly with the yeastpopulation. Although some parameters (hexose fractions converted to ethanol and glycerol) did not change,the kinetic constant related to the inactivation rate of the yeast population showed by S. cerevisiae assumeda value significantly higher (approximately 50-fold) than that observed for S. bayanus, while this latterpopulation was ten times less affected by ethanol than S. cerevisiae. Although no remarkable differencescould be found between the ability shown by the two yeast populations to convert hexoses (D-glucose andD-fructose), the tolerance for ethanol accumulation changed strongly. The conversion rate of these twohexoses by S. bayanus was affected less (about ten thousand-fold) by ethanol than that of S. cerevisiae
Power density of a bare electrodynamic tether generator
The maximum performance of bare electrodynamic tethers as power generating systems under OML-theory is analyzed. Results show that best performance in terms of power density is achieved by designing the tether in such a way to increase ohmic impedance with respect to plasma contact impedance, hence favoring longer and thinner tethers. In such condition the corresponding optimal value of the load impedance is seen to approach the ohmic impedance of the conducting tether. At the other extreme, when plasma contact impedance dominates (which is not optimal but can be relevant for some applications) optimum power generation is found by matching the load impedance with an effective tether-plasma contact impedance whose expression is derived
Metal-based compounds containing selenium: An appealing approach towards novel therapeutic drugs with anticancer and antimicrobial effects
In recent years, both metal-based complexes and selenium-containing compounds have been widely explored for
their therapeutic properties due to their roles in biological processes and modulation of diverse molecular tar-
gets. However, despite their growing interest, there is no review to date that covers the potential use of the
combination of these entities to design new therapeutic derivatives. This review highlights the latest achieve-
ments in this particular field, with a focus on compounds with anticancer and/or antimicrobial properties. With
this aim, the formation of coordination compounds including several metals bearing selenium either with direct
interaction with the metal center or as part of the organic ligand elsewhere is covered. Besides, coordination
compounds with a Se(IV) center have been assessed. The biological properties of several selenium-containing
organometallic complexes have also been discussed, including metallocenes, half-sandwich complexes, and
compounds with N-heterocyclic carbenes, CO, and π-ligands, and other σ-bonded entities. The information
compiled in this review may be helpful to design and develop novel, more potent, and safer metal-based com-
pounds for the treatment of several pathologies
Balance social de las microempresas de la confección, herrería y carpintería de las comunas 14 y 15 de la zona Suroccidental de Cartagena de Indias: un modelo administrativo enfocado al desarrollo socio económico de la comunidad
Las vivencias de la época actual en el campo económico y empresarial
presentan una clara tendencia hacia la libre iniciativa privada, impulsada por la
diversificación y evolución de nuestras estructuras a través de una
descentralización económica que delega en las diferentes organizaciones una
serie de responsabilidades tanto económicas como sociales.
Surge de ésta tendencia la concepción de la empresa como un ente
socioeconómico, que por la misma naturaleza de su conformación y
funcionamiento a través de un conjunto de seres humanos en interacción
constante en el ámbito interno y con entidades externas, da lugar a la
reafirmación de la importancia del rol que debe desempeñar la empresa como
facilitador no sólo de la ejecución de una función económica sino también de
funciones socialesIncluye bibliografíaMagíter Administración de Empresa
Small molecules containing chalcogen elements (S, Se, Te) as new warhead to fight neglected tropical diseases
Neglected tropical diseases (NTDs) encompass a group of infectious diseases with a protozoan etiology, high
incidence, and prevalence in developing countries. As a result, economic factors constitute one of the main
obstacles to their management. Endemic countries have high levels of poverty, deprivation and marginalization
which affect patients and limit their access to proper medical care. As a matter of fact, statistics remain un-
collected in some affected areas due to non-reporting cases. World Health Organization and other organizations
proposed a plan for the eradication and control of the vector, although many of these plans were halted by the
COVID-19 pandemic. Despite of the available drugs to treat these pathologies, it exists a lack of effectiveness
against several parasite strains. Treatment protocols for diseases such as American trypanosomiasis (Chagas
disease), leishmaniasis, and human African trypanosomiasis (HAT) have not achieved the desired results. Un-
fortunately, these drugs present limitations such as side effects, toxicity, teratogenicity, renal, and hepatic
impairment, as well as high costs that have hindered the control and eradication of these diseases. This review
focuses on the analysis of a collection of scientific shreds of evidence with the aim of identifying novel chalcogen-
derived molecules with biological activity against Chagas disease, leishmaniasis and HAT. Compounds illustrated
in each figure share the distinction of containing at least one chalcogen element. Sulfur (S), selenium (Se), and
tellurium (Te) have been grouped and analyzed in accordance with their design strategy, chemical synthesis
process and biological activity. After an exhaustive revision of the related literature on S, Se, and Te compounds,
183 compounds presenting excellent biological performance were gathered against the different causative agents
of CD, leishmaniasis and HAT
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A pan-Canadian dataset of neighbourhood retail food environment measures using Statistics Canada's Business Register.
BACKGROUND: The objective of this study was to create the Canadian Food Environment Dataset (Can-FED) and to demonstrate its validity. DATA AND METHODS: Food outlet data were extracted from Statistics Canada's Business Register (BR) in 2018. Retail food environment access measures (both absolute and relative measures) were calculated using network buffers around the centroid of 56,589 dissemination areas in Canada. A k-medians clustering approach was used to create categorical food environment variables that were easy to use and amenable to dissemination. Validity of the measures was assessed by comparing the food environment measures from Can-FED with measures created using Enhanced Points of Interest data by DMTI Spatial Inc. and data from a municipal health inspection list. Validity was also assessed by calculating the geographic variability in food environments across census metropolitan areas (CMAs) and assessing associations between CMA-level food environments and CMA-level health indicators. RESULTS: Two versions of Can-FED were created: a researcher file that must be accessed within a secure Statistics Canada environment and a general-use file available online. Agreement between Can-FED food environment measures and those derived from a proprietary dataset and a municipal health inspection list ranged from rs=0.28 for convenience store density and rs=0.53 for restaurant density. At the CMA level, there is wide geographic variation in the food environment with evidence of patterning by health indicators. INTERPRETATION: Can-FED is a valid and accessible dataset of pan-Canadian food environment measures that was created from the BR, a data source that has not been explored fully for health research
The residues of fruit and vegetable pro-cessing: From “waste” to “resource” of natural phytochemical compounds
The project of Sant’Anna School, in line with the Italian legislation on limiting waste and promoting the redistribution of surpluses and unused goods, aimed to study the potential healthy value of residues obtained from the trans-formation of fruit and vegetable products that represent a cost, as they must be handled, stored and disposed according to stringent actual regulations. Two “model” species (potato and apple) were considered to test the possibility of using industrial processing waste for food applications. The extracts, obtained with “green” methods from potato and apple peels, were evaluated as natural antioxidants in the preparation of minimally processed freshcut apple. Results suggest the possibility to use these novel byproduct extracts as valuable alter-native treatments to traditional chemical additives employed for minimally processed apples
Wearable Sensors to Evaluate Autonomic Response to Olfactory Stimulation: The Influence of Short, Intensive Sensory Training
In the last few decades, while the sensory evaluation of edible products has been leveraged to make strategic decisions about many domains, the traditional descriptive analysis performed by a skilled sensory panel has been seen to be too complex and time-consuming for the industry needs, making it largely unsustainable in most cases. In this context, the study of the effectiveness of different methods for sensory training on panel performances represents a new trend in research activity. With this purpose, wearable sensors are applied to study physiological signals (ECG and skin conductance) concerned with the emotions in a cohort of volunteers undergoing a short, two-day (16 h) sensory training period related to wine tasting. The results were compared with a previous study based on a conventional three-month (65 h) period of sensory training. According to what was previously reported for long panel training, it was seen that even short, intensive sensory training modulated the ANS activity toward a less sympathetically mediated response as soon as odorous compounds become familiar. A large-scale application of shorter formative courses in this domain appears possible without reducing the effectiveness of the training, thus leading to money saving for academia and scientific societies, and challenging dropout rates that might affect longer courses
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