1,727 research outputs found
Energetic metabolism in fasting sheep: regularization of metabolic profile by treatment with oral glucose, with prior handling of gastric groove
The objective of this research was to evaluate a possible corrective measure against negative metabolic states, as occurs in the advanced stage of gestation in ewes, and that sometimes produces a disease called pregnancy toxaemia. In the present research, we found that the joint administration of i.v. lysine-vasopressin (0.08 IU/kg body weight, BW) and an oral glucose solution (50 g) produces an increase in blood glucose, which persists for some time (up to 6 h); therefore, it could be used in the treatment of pregnancy toxaemia. This therapy is based on the fact that lysine-vasopressin induces gastric groove closure in adult ruminants, enabling orally administered glucose to reach the abomasum directly, from where it rapidly passes into the intestine and is immediately absorbed. We can say that the tested treatment causes a significant increase in blood glucose in ewes affected by toxaemia caused by fasting, which, although less marked than conventional therapy with intravenous drip glucose, remains longer, regularizing other parameters indicative of energy metabolism in fasting ewes
Synthetic and Mechanistic Studies on the Solvent-Dependent Copper-Catalyzed Formation of Indolizines and Chalcones
Copper nanoparticles supported on activated carbon have been found to catalyze the multicomponent synthesis of indolizines from pyridine-2-carbaldehyde derivatives, secondary amines, and terminal alkynes in dichloromethane; in the absence of solvent, however, heterocyclic chalcones are formed. We provide compelling evidence that both processes take place through aldehyde–amine–alkyne coupling intermediates. In contrast to other well-known mechanisms for chalcone formation from aldehydes and alkynes, a new reaction pathway involving propargyl amines as intermediates that do not undergo rearrangement is presented. The formation of indolizines or chalcones is driven by inductive and solvent effects, with a wide array of both being reported. In both reactions, the nanoparticulate catalyst has been shown to be superior to some commercially available copper catalysts, and it could be recycled in the case of the chalcone synthesis.This work was generously supported by the Spanish Ministerio de Economía y Competitividad (MINECO; CTQ2011-24151). M.J.A. and M.J.G.-S. acknowledge the Instituto de Síntesis Orgánica (ISO) of the Universidad de Alicante for both grants
A boiler room in a 600-bed hospital complex: study, analysis, and implementation of energy efficiency improvements
Producción CientíficaThe aim of energy efficiency is to use less energy to provide the same service. In hospitals, energy efficiency offers a powerful and cost-effective tool to reduce greenhouse gas emissions, fuel consumption, and also running costs. Over a six-month period, the six gas-fired boilers that provide both a hospital’s heat and hot water were monitored. Analysis of the data obtained led to several actions being implemented in the hospital boiler room control system to improve the efficiency of the heat production system. Comparative studies were conducted, during similar weather periods, of the performance of the hospital’s hot water production system before and after the controls were implemented. Results indicate that the control actions applied proved to be effective. Finally; the paper offers a financial; primary energy saving and CO2 reduction analysis that points to a 3,434.00 €/week savings in natural gas consumption; and a cut in CO2 emissions of 20.3 tons/week; as compared to the reference facility
Diferencias de género en relación a la práctica deportiva. Importancia de los medios de comunicación
La práctica de actividad física y deportiva han sufrido un incremento en los últimos años, aunque
es cierto que el género femenino avanza de una forma más lenta. Por ello, números programas
nacionales, autonómicos y municipales se están llevando a cabo con el objetivo de incrementar
en mayor medida el número de mujeres que realizan actividad física. En nuestro estudio llevado
a cabo con una muestra de 898 alumnos todos pertenecientes a la comunidad extremeña se
observó como existen diferencias en relación al porcentaje de practica deportiva que realizan
chicos y chicas, así como diferencias existentes en cuanto al tipo de deporte que se práctica. Los
medios de comunicación tienen una función muy importante en aumentar el número de
practicantes de género femenino
Spectral Response of Metallic Optical Antennas Driven by Temperature
When optical antennas are used as light detectors, temperature changes their spectral response. Using this relation, we determine the spectrum of a light beam from an optical antenna’s signal. A numerical evaluation of the temperature-spectral response has been completed with a model for the noise of the device. Using both the response and the noise model, we have established the capabilities of the device by quantifying the error in the spectrum determination both for broadband spectrum and monochromatic radiation
Organic carbon and environmental quality of riverine and off-shore sediments from the Gulf of Cádiz, Spain
6 páginas, 2 figuras, 3 tablas, 14 referencias.-- [email protected] we show that heavy metal geoaccumulation
is apparent in the Tinto and Odiel estuary and, at a
lower magnitude, in off-shore sediments. Values above
probable effects level (PEL) are recorded for As, Cu, Hg,
Pb and Zn in the Tinto and Odiel estuary, for As and Hg in
the associated off-shore sediments and for As in the Guadiana
River. Significant correlations were found between
total organic carbon (TOC) and Cr, Cu, Ni and Zn in the
Tinto and Odiel estuary, and Cr, Cu, Ni, Pb, Hg and As in
the Guadiana River. PCA analysis differentiated the three
studied locations.Peer reviewe
Organic carbon and environmental quality of riverine and off-shore sediments from the Gulf of Cádiz, Spain
6 páginas, 2 figuras, 3 tablas, 14 referencias.-- [email protected] we show that heavy metal geoaccumulation
is apparent in the Tinto and Odiel estuary and, at a
lower magnitude, in off-shore sediments. Values above
probable effects level (PEL) are recorded for As, Cu, Hg,
Pb and Zn in the Tinto and Odiel estuary, for As and Hg in
the associated off-shore sediments and for As in the Guadiana
River. Significant correlations were found between
total organic carbon (TOC) and Cr, Cu, Ni and Zn in the
Tinto and Odiel estuary, and Cr, Cu, Ni, Pb, Hg and As in
the Guadiana River. PCA analysis differentiated the three
studied locations.Peer reviewe
Energy Management by Dynamic Monitoring of a Building of the University of Valladolid
Producción CientíficaThe continuous increase of energy consumption in buildings enhances the importance of implementing energy
management systems within the building facilities. These tools allow us to know precisely both energy consumption and use within
the building. Monitoring energy consumption provides a clear view not only of the amount, but also of where and when energy is
consumed in the building. Besides, a rear analysis of this information allows us to deduce whether there exists an inappropriate
consumption, and thus the possibilities of improving building efficiency. A monitoring tool has been implemented within an
academic building at the University of Valladolid, applying technological resources of Information Technology and Communication
through dynamic monitoring of electrical and thermal parameters. Results obtained are gathered and analysed to directly contribute to
improve the use of energy, reduce costs associated with its generation and use, and improve the thermal comfort of the building
occupants.
Keywords: Dynamic monitoring, energy performances, energy management, reduction of building consumption
Stability of synchronous queued RFID networks
Queued Radio Frequency Identification (RFID) networks arise naturally in many applications, where tags are grouped into batches, and each batch must be processed before the next reading job starts. In these cases, the system must be able to handle all incoming jobs, keeping the queue backlogs bounded. This property is called stability. Besides, in RFID networks, it is common that some readers cannot operate at the same time, due to mutual interferences. This fact reduces the maximum traffic that readers can process since they have to share the channel. Synchronous networks share the channel using a TDMA approach. The goal of this work is to analytically determine whether a synchronous queued RFID network attains stable operation under a given incoming traffic. Stability depends on the service rate, which is characterized in this paper using an exact numerical method based on a recursive analytical approach, overcoming the limitations of previous works, which were based on simplifications. We also address different flow optimization problems, such as computing the maximum joint traffic that a network can process stably, selecting the minimal number of readers to process a given total load, or determining the optimal timeslot duration, which are novel in the RFID literature.Ministerio de Economía, Industria y Competitividad | Ref. TEC2016-76465-C2-1-
Metal-free remote-site C–H alkenylation: regio- and diastereoselective synthesis of solvatochromic dyes
Lately, transition-metal catalysed C–H alkenylation of nitrogen heterocycles has gained increasing attention, often with the intervention of complex and expensive catalytic systems. On the other hand, both, chalcones and indolizines are versatile families of compounds with applications in diverse research areas, including materials science, because of their prominent photophysical attributes. We set forth herein the metal-free regio- and diastereoselective C–H alkenylation of indolizines through a very simple and mild acid–base approach. The most fascinating fact in this remote-site Csp2–Csp2 bond formation is that only one starting material is utilised, which undergoes a formal self-alkenylation to integrate a chalcone moiety and furnish a new family of dyes; a plausible reaction mechanism has been put forward. A one-pot multicomponent protocol was conceived that generates the starting indolizine in situ and has been extended to a multi-gram scale synthesis with equal efficiency. The dyes show a single structure in the solid state but two stable structures in solution (rotamers). Preliminary studies on the optical properties of the dyes reveal a particle-size dependent colour in the solid state and solvatochromism (i.e., different colours in solution depending on the solvent polarity). Remarkably, the solvatochromic behaviour was also displayed in plastics. We believe that this finding opens new avenues in the fields of heterocyclic chemistry, dyes, and materials science.This work was generously supported by the Spanish Ministerio de Economía y Competitividad (MINECO; CTQ2011-24151 and CTQ-2015-66624-P) and the Generalitat Valenciana (GV; grants no. APOTIP/2015/014 and AEST/2015/001). M. J. A. and M. J. G.-S. are grateful to the Instituto de Síntesis Orgánica (ISO) for both pre-doctoral grants (contracts no. I-PAS-44/13 and I-PAS-11/16)
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