495 research outputs found
Synthesis of pyrrolo[1,2-<i>a</i>]indole-1,8(5<i>H</i>)-diones as new synthons for developing novel tricyclic compounds of pharmaceutical interest
In the course of our work aimed at developing novel heterocycles of pharmaceutical interest, a
new tricycle, the tetrahydropyrrolo[1,2-a]indole-1,8-dione, has been synthesized by an
intramolecular Friedel-Crafts acylation, as a synthon suitable to be functionalized to give novel
compounds with potential biological properties. Also, an unusual nucleophilic α-addition to
methyl propiolate by 1,5,6,7-tetrahydro-4H-indol-4-one was observed and discussed
Design of a New System of High-power Efficiency Conditioning Cogeneration Energy for a Building of the University of Cagliari with Fossil Fuel Plants
Abstract An analysis of Italy's National Energy Budget of in the last decades shows the important role of the civil sector and the impact of fossil fuels in air conditioning systems. The high consumption of fossil fuel is Likely due to the predominance of plants with conventional boilers in buildings. Based on the analysis of the Exergy flow this paper proposes the Cogeneration technology for Air conditioning systems with heat pumps to implement the Rational Use of Energy. The feasibility of a retrofit intervention on existing systems of a large size is shown, by the projection of a cogeneration plant for the buildings of the University of Cagliari currently equipped with fossil fuel plants
An Energy Autonomous House Equipped with a Solar PV Hydrogen Conversion System
The use of RES in buildings is difficult for their random nature; therefore the plants using photovoltaic solar collectors must be connected to a power supply or interconnected with Energy accumulators if the building is isolated. The conversion of electricity into hydrogen technology is best suited to solve the problem and allows you to transfer the solar energy captured from day to night, from summer to winter. This paper presents the feasibility study for a house powered by PV cogeneration solar collectors that reverse the electricity on the control unit that you command by a PC to power the household, using a heat pump, an electrolytic cell for the production of hydrogen to accumulate; control units sorting to the utilities the electricity produced by the fuel cell. The following are presented: The Energy analysis of the building, the plant design, economic analysi
Solar Energy System in A Small Town Constituted of A Network of Photovoltaic Collectors to Produce Electricity for Homes and Hydrogen for Transport Services of Municipality
The supply of Energy resources to the villages located in inland and hilly regions, is disadvantageous both for the domestic and transport purposes. Because these conditions may produce the depopulation of the inland zone, a smart way to ease this inconvenience is to produce in situ electrical Energy for houses and fuel for cars, getting them from an available Energy source in the village, as the solar Energy. The only technology to produce hydrogen ecologically and to minimize CO2 emission, is through RES (Renewable Energy Sources). The solar energy plants must use the surfaces of buildings instead of occupying other green areas useful for agricultural activities. On this basis, we propose in this paper a demonstrative project for a village in Sardinia, consisting of photovoltaic collectors connected in a network, to provide electricity to homes and hydrogen for transport purposes
Xerostomia induced by radiotherapy: an overview of the physiopathology, clinical evidence, and management of the oral damage
Background: The irradiation of head and neck cancer (HNC) often causes damage to the salivary glands. The resulting salivary gland hypofunction and xerostomia seriously reduce the patient’s quality of life.
Purpose: To analyze the literature of actual management strategies for radiation-induced hypofunction and xerostomia in HNC patients.
Methods: MEDLINE/PubMed and the Cochrane Library databases were electronically evaluated for articles published from January 1, 1970, to June 30, 2013. Two reviewers independently screened and included papers according to the predefined selection criteria.
Results: Sixty-one articles met the inclusion criteria. The systematic review of the literature suggests that the most suitable methods for managing the clinical and pathophysiological consequences of HNC radiotherapy might be the pharmacological approach, for example, through the use of cholinergic agonists when residual secretory capacity is still present, and the use of salivary substitutes. In addition, a modified diet and the patient’s motivation to enhance oral hygiene can lead to a significant improvement.
Conclusion: Radiation-induced xerostomia could be considered a multifactorial disease. It could depend on the type of cancer treatment and the cumulative radiation dose to the gland tissue. A preventive approach and the correct treatment of the particular radiotherapeutic patient can help to improve the condition of xerostomia
Influence of body weight on reproductive activity in Sarda female lambs
One way to improve reproductive performance of ewes is through extending its lifetime
productivity. Breeding ewe lambs is one method of improving the reproductive performance in the sheep.
In order to produce an offspring when the ewe lamb is approximately 1 yr of age, the autumn-born ewe must
obtain puberty before the autumn breeding season begins. Onset of puberty is determined by integration of
both internal and external factors, which then enable the neuroendocrine or hormonal event occur (Shirley et
al., 2001). Age, photoperiod and body weight are the principal factors influencing puberty. The age at onset of
the reproductive activity in the sheep is different among the various breeds. In the Sarda lambs the age of the
onset of puberty is about 7-8 months. However the animals that have this age don’t reach the puberty if photoperiod
and body weight are not suitable. Both the female lambs born in October-November and in February
reach puberty in the same subsequent autumn breeding season. This reproductive behaviour evidences that
photoperiod plays an important role in the onset of puberty (Papachristoforou et al., 2000).The female lambs
born in later spring uneasily reach puberty within the subsequent breeding season, although photoperiod is
favourable. This retard in the onset of reproductive activity is due to the attainment of the body maturity only
during subsequent long day period but they reach reproductive activity only during the autumn of the subsequent
year (Foster et al., 1985). In fact, some authors suggested that besides photoperiod and age, attainment
of the 60% of adult weight is essential for onset of puberty (Abecia et al., 2001). Indeed the undernourished
animals delay puberty, in comparison to well nourished subjects (I’Anson et al., 1997). This behaviour is linked
to the different LH pulse frequency: restricted diet lambs show one pulse per 4 hours, instead fed ad libitum
subjects manifest four or five pulse per 4 hours (Ebling et al., 1990).
The purpose of this investigation is to determine the onset of puberty and to research its linkage with body
weight in Sarda female lambs during breeding season under natural condition
Simulation of growth of Ni-Zr interfacial amorphous regions under nonequilibrium conditions
We have simulated the response of an interfacial amorphous region formed between nickel and zirconium lattices upon temperature increase or the application of uniaxial load by means of molecular-dynamics simulation of a model system based on an n-body potential. The behavior of the amorphous region has been investigated as a function of the load intensity and duration. The system reacts upon uniaxial load application with the growth of the amorphous interface. This has been related to the structural change occurring in the glassy region in the form of a density variation consequent to the introduction of excess free volume. These findings are qualitatively consistent with the current hypothesis invoked to explain diffusion and growth of interfacial amorphous regions formed upon load application on bulk diffusion couples
Detection and characterization of Rickettsial strains in ticks from Sardinia, Italy
The aim of this study was, firstly, to detect the presence of Rickettsial DNA by PCR and, then, to identify
the Rickettsiae species using restriction endonuclease fragment length polymorphism (RFLP) on two amplified
genes
Improving Fast Minimum-Norm Attacks with Hyperparameter Optimization
Evaluating the adversarial robustness of machine-learning models using gradient-based attacks is challenging. In this work, we show that hyperparameter optimization can improve fast minimum-norm attacks by automating the selection of the loss function, the optimizer, and the step-size scheduler, along with the corresponding hyperparameters. Our extensive evaluation involving several robust models demonstrates the improved efficacy of fast minimum-norm attacks when hyped up with hyperparameter optimization. We release our open-source code at https://github.com/pralab/HO-FMN
Slow slip detection with deep learning in multi-station raw geodetic time series validated against tremors in Cascadia
Slow slip events (SSEs) originate from a slow slippage on faults that lasts
from a few days to years. A systematic and complete mapping of SSEs is key to
characterizing the slip spectrum and understanding its link with coeval
seismological signals. Yet, SSE catalogues are sparse and usually remain
limited to the largest events, because the deformation transients are often
concealed in the noise of the geodetic data. Here we present the first
multi-station deep learning SSE detector applied blindly to multiple raw
geodetic time series. Its power lies in an ultra-realistic synthetic training
set, and in the combination of convolutional and attention-based neural
networks. Applied to real data in Cascadia over the period 2007-2022, it
detects 78 SSEs, that compare well to existing independent benchmarks: 87.5% of
previously catalogued SSEs are retrieved, each detection falling within a peak
of tremor activity. Our method also provides useful proxies on the SSE duration
and may help illuminate relationships between tremor chatter and the nucleation
of the slow rupture. We find an average day-long time lag between the slow
deformation and the tremor chatter both at a global- and local-temporal scale,
suggesting that slow slip may drive the rupture of nearby small asperities
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