6,428 research outputs found
Experimental insight into the magnetic and electrical properties of amorphous Ge1-xMnx
No full textWe present a study of the electrical and magnetic properties of the amorphous Ge1-xMnx.DMS, with 2% ≤ x ≤ 17%, by means of SQUID magnetometry and low temperature DC measurements. The thin films were grown by physical vapour deposition at 50°C in ultrahigh vacuum. The DC electrical characterizations show that variable range hopping is the main mechanism of charge transport below room temperature. Magnetic characterization reveals that a unique and smooth magnetic transition is present in our samples, which can be attributed to ferromagnetic percolation of bound magnetic polarons
Thermal physical modelling for eye injury prevention in high environmental temperature workplaces
No full textBackground: High temperatures are encountered in many workplaces as iron and
steel foundries, nonferrous foundries, brick-firing and ceramic plants, glass
products facilities, rubber products factories, electrical utilities, bakeries, laundries,
chemical plants, mining sites, smelters, and steam tunnels. Workers in these
industries can suffer from various diseases and injuries, including eye problems,
due to exposure to high temperatures and handling of heavy materials.
Methods: This study aims to analyse the pressure inside the eye's anterior
chamber, known as Intraocular Pressure (IOP), and its relation to the biomechanical
properties of the cornea, specifically concerning the cornea's temperature. The
approach used is based on the first law of thermodynamics. The results
demonstrate the relationship between the ocular anterior chamber's temperature
and the cornea's biomechanical properties.
Results: The IOP measures the cornea's elasticity and its refractive properties
concerning its temperature. We develop a study to investigate how the cornea's
elastic work, or potential energy, changes with temperature. Our findings indicate
that as the temperature rises, the work done by the cornea decreases. The cornea's
temperature is affected by both the surrounding environment and the temperature
of the fluid in the front part of the eye. This suggests a link between the work done
by the cornea against the pressure of the fluid in the front of the eye and the fluid.
Accordingly, there is also a correlation between the thickness of the cornea and the
IOP, and our modelling method enables us to establish this relationship.
Conclusions: The first law of thermodynamics is used to determine the work done
by the anterior chamber against the internal cornea wall. Temperature regulates
the aqueous humour's secretion, excretion, and flow dynamics, impacting IOP and
related diseases. This has implications for developing preventive systems to protect
workers' eyes from injury
1H NMR-based metabolomic study of a mother-infant dyad on the evolution of gut microbiota during the breastfeeding and weaning
No full textHuman milk is a buffet of fats, proteins and sugars, designed to be easily digestible and to provide an adequate supply of nutrients to support healthy growth and development of the infant. In addition, milk is rich of nonnutrient bioactive factors, such as cells, anti-infectious and anti-inflammatory agents, growth factors, and prebiotics, providing protection to the newborn. Among this plethora of components, human milk oligosaccharides (HMOs) were supposed to have anti-adhesive and antimicrobials properties, thus preventing pathogen attachment to infant mucosal surfaces and lowering the risk for viral, bacterial and protozoan parasite infections [1]. Furthermore, HMOs were recognized as a substrate to promote the growth of desired bacteria, such as bifidobacteria, in the infant’s intestine (“bifidogenic” or prebiotic effects) [2]. Early microbial colonization is essential for healthy intestinal and immunological development in neonates. The development of gut microflora during infancy consists in a complex succession of bacterial species, modulated by breastfeeding, perinatal antibiotic use and environmental factors. In a recent study, we have compared the changing fecal microbial composition with the fecal metabolome of newborns in the first thirty days of the breastfeeding [3]. The results showed a relation between microbiota and fecal biochemical composition, probably linked to the changes of breast milk composition during the maturation process.In this study, we have investigated, by 1H NMR spectroscopy, the changes of the neonatal fecal metabolome in relation to diet: breastfeeding and weaning. We have examined breast milk and newborn faeces of a single mother-infant dyad for 6 months, starting from the 4th month after the birth, in order to evaluate the changes in microbial metabolome during the diet evolution. The NMR spectroscopy of the breast milk allowed to recognize the mother’s phenotype as Secretor (FUT2 gene positivity) on the basis of the structure of fucosyl-HMO, and to confirm the stability of milk biochemical composition during the considered period of lactation. On the other hand, the NMR analysis of fecal samples showed that the microbiota HMO metabolism changed as a function of time, and furthermore the daily variability increased during the weaning period. Therefore, important experimental aspects are evidenced in order to obtain representative samples of faeces from newborns to compare metabolomics with metagenomics data. The results display the evolution of the infant gut microbiota metabolism in relation to changes of the diet composition
A 4.1-mW 10-MHz Fourth-Order Source-Follower-Based Continuous-Time filter with 79-dB DR
No full textIn this paper, a “composite” source-follower is presented. Using a positive-feedback, the structure synthesizes complex poles with a single branch. This allows to realize a single-branch biquadratic cell. Moreover, due to the intrinsic feedback present in any source-follower, the proposed cell performs larger linearity for smaller Vov (=VGS-VTH ). This is the opposite of other active filters and allows saving the power otherwise used to increase linearity. A fourth-order prototype satisfy typical WLAN 802.11.a/b/g baseband filter specifications has been realized in a 0.18um CMOS at 1.8-V supply. It achieves a 17.5-dBm IIP3 and a -40dB HD3 for a 600-mVpp_diff input signal amplitude. A 24-uVrms noise gives a DR = 79 dB, with 2.25mA current consumption
Ni80Fe20 nanodisks by nanosphere lithography for biomedical applications
No full textA novel nanofabrication technique based on self-assembling of polystyrene nanospheres and aimed to obtain magnetic nanodisks suspended in ethanol is here presented. Free-standing Ni 80Fe20 disks having lateral dimension around 650 nm and thickness 30 nm were obtained by using nanosphere lithography on a sputtered continuous thin film. The multi-step nanofabrication process will be explained, in detail. The process end-product can be used as suitable magnetic carriers having nearly monodispersed size and simultaneously displaying high saturation magnetization and low-coercivity. Magnetisation reversal has been studied by room-temperature hysteresis loop measurements in either dot arrays attached on a substrate or in liquid-dispersed free-standing nanodisks. In both samples, the reversal is marked by magnetic vortex nucleation/annihilation. Such a behavior is confirmed for Ni 80Fe20 dot arrays by measuring magnetic domain configuration, while numerical simulation is used for confirming magnetization reversal process in nanodisks
NMR-based metabolomics to evaluate the milk composition from Friesian and autochthonous cows of Northern Italy at different lactation times.
No full textIt is well established that different factors affect milk composition in cows and that milk composition, in turn, affect both technological and nutritional qualities. In this respect the comprehension of the metabolic variability of milk composition in relation to the lactation time as well as to the genetic background may be of paramount importance for the agri-food industries. In the present study we investigated the variations of the metabolic profiles during lactation in milks obtained from Friesian and autochthonous races from Northern Italy by 1H NMR metabolomics. Furthermore, the external factors influencing the milk composition were minimized: the cows were breeded in the same farm, were fed with the same diet and were paired for the lactation interval and lactation stage. Our results showed a difference in milk composition between races and in relation to late lactation. The PLS-DA analysis permitted to distinguish the Friesian and autochthonous cow milks at the investigated different lactation times. Interestingly, the metabolites significantly involved into the discrimination between races appeared to be also technological property parameters, highlighting the importance of maintaining the biodiversity of cow breeds. Therefore, NMR-based metabolomics of milk could represent an informative tool to identify metabolites involved in milk quality both from a nutritional and industrial perspective
Inelastic intermediate states in proton-deuteron and deuteron-deuteron elastic collisions at the ISR
No full textWe present experimental results on proton-deuteron and deuteron-deuteron elastic scattering. In both reactions we find clear evidence
for a substantial contribution of inelastic intermediate states in the multiple-scattering region, as well in single scattering
Features of coherent neutron diffraction on deuterons at the ISR
No full textResults are reported on the measurement of the differential cross-section for the coherent neutron dissociation on deuterons
Targeted and untargeted metabolomics applied to occupational exposure to hyperbaric atmosphere
No full textOccupational exposure to hyperbaric atmosphere occurs in workers who carry out their activity in environments where breathing air pressure is at least 10% higher than pressure at sea level, and operations can be divided in Dry or Wet activities. The increased air pressure implies the formation of reactive oxygen species (ROS) and reactive nitrogen species (RNS), consumption of antioxidants and reduction of antioxidant enzyme activity, causing lipid peroxidation, DNA and RNA damage. The present study was aimed to establish the relation between hyperbaric exposure and metabolic changes due to ROS unbalance, by means of the determination of
urinary biomarkers of oxidatively generated damage to DNA and RNA during a controlled diving session. The investigated biomarkers were 8-oxo-7,8-dihydroguanine (8-oxoGua), 8-oxo-7,8-dihydroguanosine (8-oxoGuo), and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo). The experimental session involved six experienced divers subjected to 3 atmospheres absolute for 30 minutes
in two different experiments, in both dry and wet conditions. Urine samples were collected at t = 0 (before exposure) and 30 (end of exposure),90, 240, 480 and 720 minutes. The concentration of 8-oxoGua, 8-oxoGuo, and 8-oxodGuo was determined by isotopic dilution high performance liquid chromatography (HPLC-MS/MS). In all subjects there is an increase of the urinary excretion of 8oxo-Guo and 8oxo-dGuo, in both conditions, after 1.5 - 4 hours from the start of the experiment, and that the values tend to return to the baseline after 12 hours. Besides that, also the nucleic magnetic resonance (NMR)-based untargeted metabolomics was employed for the same objective on the same samples, confirming a different metabolic response in the subjects exposed to dry or wet conditions. In particular, the observed hypoxanthine urinary level increases during the underwater hyperbaric exposure, in agreement with the trend observed for 8-oxoGuo and 8-oxodGuo levels. Present results confirmed the relationship between exposure and oxidative stress and depicted a clear temporal trend of the investigated biomarkers. Due to the possible negative consequences of oxidative stress on workers, present research shows a new line in term of risk prevention
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