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In this work, the pressure- and temperature-dependent reaction rate constants for the hydrogen abstraction and addition of hydroxyl radicals to the unsaturated cyclopentene were studied. Geometries and vibrational frequencies of reactants, products, and transition states were calculated using density functional theory, with single-point energy corrections determined at the domain-based local pair natural orbital-coupled-cluster single double triple/cc-pVTZ-F12 level. The high-pressure limit rate constants were calculated using the canonical variational transition state theory with the small-curvature tunneling approximation. The vibrational partition functions were corrected by the effects of torsional and ring-puckering anharmonicities of the transition states and cyclopentene, respectively. Variational effects are shown to be relevant for all the hydrogen abstraction reactions. The increasing of the rate constants by tunneling is significant at temperatures below 500 K. The pressure dependence on the rate constants of the addition of [Formula: see text] to cyclopentene was calculated using the system-specific quantum Rice–Ramsperger–Kassel model. The high-pressure limit rate constants decrease with increasing temperature in the range 250–1000 K. The falloff behavior was studied at several temperatures with pressures varying between 10−3 and 103 bar. At temperatures below 500 K, the effect of the pressure on the addition rate constant is very modest. However, at temperatures around and above 1000 K, taking pressure into account is mandatory for an accurate rate constant calculation. Branching ratio analyses reveal that the addition reaction dominates at temperatures below 500 K, decreasing rapidly at higher temperatures. Arrhenius parameters are provided for all reactions and pressure dependent Arrhenius parameters are given for the addition of [Formula: see text] to cyclopentene.

Composite materials based on CaO obtained from egg shells and k-carrageenan, an anionic sulfated linear polysaccharide obtained from red seaweeds was used as an efficient, environmentally friendly heterogeneous catalyst for the transesterification of soybean oil with methanol at 60 °C. The different composite samples were produced through the dissolution of the biopolymer in an ionic liquid (IL) derived from imidazolium ion and by further addition of CaO. The samples were characterized by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM) and Termogravimetry (TGA). The materials exhibit an internal structure consisting of meso and macropores which widen with the addition of small amounts of Hexamethylene diisocyanate (HMDI) that acts as a crosslinker. The composite materials present a similar thermal behaviour to k-carrageenan, without loss of stability. The catalytic activity of the prepared composite materials was evaluated in the transesterification reaction of soybean oil with methanol through catalytic runs in batch conditions. It was found that both CaO loading and polymer cross-linking affect the sorption capacity and the transport properties of the prepared catalytic materials, with best results obtained for the intermediate CaO concentration in membrane and a lower crosslinking degree.

As life expectancy increases, an increasing older population may require surgery with perioperative nutritional management. While little is known about the combined effect of age and stress on amino acid metabolism during enteral nutrition, we hypothesized that blood amino acid bioavailability may be influenced not only by the characteristics of the ingested protein but also by intestinal ageing and splanchnic sequestration of amino acids. Plasma amino acid kinetics were thus evaluated in aged and adult rats receiving continuous enteral nutrition before and after standardized surgical stress.Sixteen 5-month-old and sixteen 21-month-old male rats were used. After a gastrostomy, the insertion of a jugular vein catheter and a one-week recovery, the animals were enterally fed with commercially available formulas containing whole milk proteins or a whey hydrolysate for 24 h before (healthy state) and 18 h after a standardized laparotomy (surgical stress). Data were analyzed by 3-factor ANOVA.In all rats, enteral nutrition was associated with a marked increase in plasma alanine, threonine, lysine and proline (+50 to +150 μmol/L; p 0.001), and a decrease in glycine (≈-80 μmol/L; p 0.01). For most amino acids, their availability depended first on the amino acid composition of each protein and second on surgical stress. Aging was only associated with higher tyrosine and threonine availability (p 0.001). There was only limited statistical interaction between age and surgical stress.In rats, plasma amino acid availability during continuous enteral nutrition is determined by the nature of the protein source and the occurrence of stress. The effects of aging on plasma amino acid availability seem very limited. Commonly used formulas therefore appear to be as suitable for elderly patients as for adult patients.

Summary Background & aims Dietary amino acid (AA) requirements increase after a surgical stress while the systemic AA availability from the diet decreases with age, due to splanchnic sequestration. While immune-enhancing diets (IEDs) have been recommended for the nutritional management of surgical patients, the systemic bioavailability of their AA supply has not been evaluated in elderly surgical patients. This was determined in surgically-stressed IED-fed aged rats. Methods Thirty-four 5-month- or 21-month-old male Sprague–Dawley rats were used. After a gastrostomy and placement of a jugular vein catheter and a one-week recovery period, the animals underwent two 24 h-enteral feedings with an arginine-enriched IED (Impact®, Nestle Health Science) before (healthy state) and 18 h after a standardized laparotomy, used as a model of surgical stress. During enteral nutrition, blood samples were repeatedly collected to measure plasma AA bioavailability (incremental areas under the curve) at 2, 5 and 24 h. Surgical stress was evaluated from urinary catecholamines and plasma protein profile. Results Whatever the age or stress situation, IED feeding was associated with decreased plasma glycine and increased alanine, proline and arginine. Aging was mainly associated with a delayed plasma AA accumulation in the first hours after the initiation of enteral nutrition. Stress was associated with higher plasma arginine increase and lower histidine, methionine, phenylalanine and tyrosine accumulation. Age and stress interactions seem limited. Conclusions AA bioavailability from an arginine-enriched IED seems to be maintained whatever age and stress situation. Aging appears to be mainly associated with a delay in plasma AA accumulation probably related to age-associated splanchnic sequestration of AAs. Additional effects of surgical stress per se seem limited.

Thyroid diseases affect a considerable portion of the population, with hypothyroidism being one of the most commonly reported thyroid diseases. Levothyroxine (T4) is clinically used to treat hypothyroidism and suppress thyroid stimulating hormone secretion in other thyroid diseases. In this work, an attempt to improve T4 solubility is made through the synthesis of ionic liquids (ILs) based on this drug. In this context, [Na][T4] was combined with choline [Ch]+ and 1-(2-hydroxyethyl)-3-methylimidazolium [C2OHMiM]+ cations in order to prepare the desired T4-ILs. All compounds were characterized by NMR, ATR-FTIR, elemental analysis, and DSC, aiming to check their chemical structure, purities, and thermal properties. The serum, water, and PBS solubilities of the T4-ILs were compared to [Na][T4], as well as the permeability assays. It is important to note an improved adsorption capacity, in which no significant cytotoxicity was observed against L929 cells. [C2OHMiM][T4] seems to be a good alternative to the commercial levothyroxine sodium salt with promising bioavailability.

Multiwall carbon nanotubes (MWCNTs) were systematically fragmented using high density ultrasonic energy and used as fillers of a poly (methyl methacrylate) matrix (PMMA). MWCNT fragmentation was confirmed by scanning electron microscopy and atomic force microscopy. Dedicated MWCNT length measurements yielded a log-normal statistical distribution, with mean value of 1.33 μm for the as-received MWCNTs and 0.66 μm for the fragmented MWCNTs. Higher electrical percolation threshold and lower electrical conductivity were obtained for MWCNT/PMMA composites (0.01–1 wt.% MWCNT concentration) using the fragmented MWCNTs. Higher electro-mechanical (piezoresistive) sensitivity under tensile tests was measured for PMMA nanocomposites with fragmented MWCNTs, which was explained by a competition of mechanisms related to the MWCNT length.

Magnetic citric acid-modified cellulose was successfully produced and tested for the removal of copper in aqueous solution. Initially, the cellulose material was reacted with citric acid solution. The modified cellulose was then attached to the Fe2O3nanoparticle producing an adsorptive magnetic material. Characterization using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy indicated successful binding and chemical modification of the cellulose. Its adsorption was also studied to evaluate its potential in removing heavy metals such as copper. Removal of copper was as high as 84.74% in solution containing 25 mg/L copper. The sorption of copper in the magnetic sorbent follows second-order kinetics and best fits Freundlich isotherm model. The developed material has a strong magnetic response, thus its recovery in the aqueous solution could be easily facilitated using a magnetic field. Regeneration study indicated high recovery efficiency maintaining above 95.7% copper removal efficiency after three cycles of use. Thus, a highly efficient magnetic adsorptive material was produced using simple chemical modification aside from its easy recovery in the water.

Spinosad and temephos are two of the most used pesticides in Mexico for the control of vector causing disease such as dengue, chikungunya and Zika. The aim of this study was to compare the neurotoxic effects of these two pesticides using guppy fish (Poecilia reticulata) as a model organism. Guppies were exposed for 7 and 21 days to technical grade temephos and spinosad at 1.0 and 0.07 g/L, respectively, (10 and 0.5 mg/L of active substance; concentrations recommended by the Ministery of Health of the State (Secretaría de Salud de Nayarit (SSN) Mexico)). Subsequently, acetylcholinesterase activity (AChE) and acetylcholine concentrations (ACh) in muscle tissue were determined. Temephos exposure decreased AChE activity and increased ACh concentration, whereas exposure to spinosad only increased ACh concentration. Though cholinergic alterations were more severe in fish exposed to temephos, both pesticides were equally lethal during the first seven days after exposure. Nonetheless, temephos was more lethal after 21 days.

Polyhydroxybutyrate (PHB) is a biopolymer of natural origin, one of the suitable alternatives for synthetic plastics. However, pure PHB has a high production cost, is relatively brittle, and has poor processability, hence its limited application. Combining PHB with biomass fillers and plasticizers can significantly improve the properties of the polymer, leading to its commercial usage. In this study, PHB was incorporated with starch (S) as a cheap biomass filler and lauric acid (LA) as a potential plasticizer. The PHB/S/LA composites were prepared using a modified solvent casting method with the incremental addition of LA. The PHB/S ratio was maintained at a ratio of 80/20 (w/w). Physicochemical characterization via EDS, XRD, and FTIR proved that the composite components have blended through nucleation and plasticization processes. The morphology of the PHB/S blends was found to be a heterogeneous matrix, with decreased inhomogeneity upon the addition of LA in the composite. Thermal characterization done by TGA and DSC showed that the thermal properties of PHB/S films improved with the addition of LA. Mechanical tests (UTM) proved that the elastic strain of the films also increased with the addition of LA, although the tensile strength decreased slightly compared to pure PHB/S. Overall, the results of this study provide baseline information on the improvement of PHB-based bioplastics.

Introduction et but de l’etude Avec l’allongement de l’esperance de vie, une population de plus en plus âgee necessite une chirurgie avec prise en charge nutritionnelle perioperatoire. On sait peu de choses sur l’effet combine de l’âge et du stress sur le metabolisme des acides amines (AA) apportes par la nutrition enterale (NE). En outre, les benefices respectifs de l’apport de proteines entieres ou d’hydrolysats de proteines lors de la NE demandent a etre plus precisement evalues dans le contexte du vieillissement intestinal et de la sequestration splanchnique des AA. Ces questions ont ete adressees chez des rats âges ou adultes soumis a une NE continue de 24 heures avant et apres un stress chirurgical standardise. Materiel et methodes Trente-deux rats mâles Sprague-Dawley âges de 5 ou 21 mois ont ete utilises. Apres acclimatation, une sonde de gastrostomie et un catheter jugulaire ont ete mis en place et les animaux ont beneficie d’une semaine de recuperation. Ensuite, les animaux ont ete nourris par voie enterale (317 kJ/24 h et 4,15 g de proteines/24 h) pendant 24 heures avant (etat sain) et 18 heures apres une laparotomie standardisee (stress operatoire). Ils ont recu une NE standard apportant soit des proteines entieres de lait soit un hydrolysat de lactoserum (Sondalis HP ou Peptamen HN, Nestle Health Science respectivement). Des echantillons de sang ont ete preleves a plusieurs reprises pour la mesure des concentrations plasmatiques des AA et le calcul de l’enrichissement et de l’aire incrementale sous la courbe (iAUC) pendant chaque periode de NE. Les animaux ont ete mis a mort a la fin de la 2e periode de NE. Analyse statistique : ANOVA a trois facteurs (source de proteines, âge et stress) et ANOVA a trois facteurs pour mesures repetees ; seuil de significativite : p Resultats et analyse statistique Quelles que soient les conditions, la NE est associee a un enrichissement plasmatique important (+50 a 150 μmol/l ; p Conclusion La disponibilite plasmatique des AA au cours d’une NE continue est determinee d’abord par la nature de l’apport en proteines et ensuite par l’existence d’un stress. Les effets du vieillissement semblent tres limites. Le vieillissement ne semble pas avoir d’effet negatif sur la disponibilite postoperatoire des AA, qu’il s’agisse d’un hydrolysat proteique ou de proteines entieres.

The CUORE Crystal Validation Runs (CCVRs) have been carried out since the end of 2008 at the Gran Sasso National Laboratories, in order to test the performances and the radiopurity of the TeO$_2$ crystals produced at SICCAS (Shanghai Institute of Ceramics, Chinese Academy of Sciences) for the CUORE experiment. In this work the results of the first 5 validation runs are presented. Results have been obtained for bulk contaminations and surface contaminations from several nuclides. An extrapolation to the CUORE background has been performed., 11 pages, 8 figures

We set out to examine the relations between prenatal exposure to the natural disaster Superstorm Sandy, maternal depression, and offspring electrodermal activity (EDA). EDA was measured via skin conductance response (SCR) magnitude in 198 children (M = 42.54 months, SD = 12.76) during a startle paradigm. In keeping with prior research, we expected prenatal depression to be associated with hyporeactive EDA and prenatal stress to be associated with hyperreactive EDA. SCR magnitude was lower in children prenatally exposed to depression alone, when compared to Superstorm Sandy, and controls. SCR magnitude of children prenatally exposed to both maternal depression and the storm was lower than that of all other groups. Our results emphasize the influence of maternal prenatal mental health, support targeted risk assessment for children who experienced an adverse prenatal environment, and highlight the need for a deeper understanding of the interactions between maternal mood and stress on the developing child.

In this work polyelectrolyte multilayers (PEMs) produced through the layer-by-layer (LbL) method were used for the in situ synthesis of Au and Ag metal nanoparticles on the surface of float glass in order to colour it. The samples were characterized by UV–Vis absorption spectroscopy, Scanning Electron Microscopy (SEM), Rutherford Backscattering Spectrometry (RBS) and Particle Induced X-Ray Emission (PIXE). The use of temperatures slightly above the glass transition temperature (Tg) during the thermal treatment allowed the fixing of the nanoparticles, colouring the glass surface. Pink and blue colours were obtained from Au nanoparticles, yellow colour from Ag, and orange from a mixture of both Au nanoparticles and Ag nanoparticles. Variables such as the pH value during film assembly, the number of layers used to form the PEMs, the time duration of thermal treatment, and the presence or absence of Sn in the surfaces of float glass, all influence its colouration. Thermal treatments shorter than 1 h already promote the diffusion of Ag into the glass and therefore fix it, while longer times are necessary to fix the Au metal. The Ag colour intensity in the glass is easily controlled through the number of layers while in the case of Au this variable influences not only the colour intensity but also the tone.

The [bmim][BF4] ionic liquid effect on gold nanoparticles formation in silica sol–gel materials is studied in order to produce gel-derived glasses with optical properties. The characteristic red color from gold nanoparticles is observed for transparent glass monoliths obtained sintering, between 365 and 425 °C, a silica sol–gel precursor containing HAuCl4·3H2O and [bmim][BF4], under normal atmospheric conditions. The effect of sintering the ionogel at different temperatures (Tsint) or times (tsint) on the optical properties, shape, size, and distribution of gold nanoparticles is discussed. Presence of the gold particles is observed using transmission electron microscopy images followed by energy dispersive X-ray spectroscopy analysis. The thermal decomposition of [bmim][BF4] in the ionogel is investigate using calorimetric and spectroscopic techniques, and by analysis of volatile compounds released by the sol–gel material during sintering. With these results a mechanism for the formation of the gold nanoparticles is proposed, where a first ionic liquid degradation step provides the reductive environment that enables the gold nanoparticles production at the range of temperatures between 350 and 425 °C. Upon sintering the synthesized materials the ionic liquid acts as a sacrificial additive and the ionic liquid thermal decomposition products enables the formation of gold nanoparticles in the sol–gel matrix.

In this work, coloured glasses were produced based on the synthesis of gold and silver nanoparticles by the sol–gel process having in mind their application in art works. Gold and silver were used separately or as a mixture by varying the mole fractions in order to get a range of colours from yellow to red. The gold and silver nanoparticles were prepared by the reduction of tetrachloroauric acid and silver nitrate with sodium citrate in aqueous solutions which were further introduced in the sol–gel system. Attention was focused on the thermal treatment of the sol–gel samples. Different temperatures were used in order to determine their influence on the obtained colour. The glasses were characterized by UV–Vis absorption spectroscopy and the size of the nanoparticles was examined by transmission electron microscopy (TEM). The range of colours mentioned above is obtained either by preparing nanoparticles of each metal and mixing them or by preparing nanoparticles from solutions containing initially ions of both metals. In the former case, two surface plasmon resonance (SPR) bands were observed for temperatures below 200 °C while higher temperatures promote the formation of alloys between the Ag and Au nanoparticles. In the latter case, only one SPR band is observed and the nanoparticle size distribution is narrower. The results were explained by nanoparticle aggregation promoted by temperature. Glasses containing only Ag did not present the typical yellow colour above 300 °C but it was shown that the colour could be stabilized if Au was added in small amounts (Au/Ag molar ratio 0.1).

Woven Nomex® ribbon cables made up with superconducting niobium–titanium wire are used at millikelvin temperatures in many large cryogenic instruments. It is important to know how much heat in transmitted down such cables. However, the conductivity of the materials used is not well known. Another problem is that the wires are normally clad with alloys which exhibit some magnetism. This is a potential problem for instruments employing superconducting detectors. A safe non-magnetic alternative to the usual materials is phosphor-bronze clad niobium–titanium wiring. However, there is little experience with such wires. We have therefore measured the conductance of a ribbon cable made up with these wires. The measured values are in good agreement with our predictions, suggesting that the values we have used to model the cable are sufficiently accurate, and could therefore be used to predict the performance of ribbon cables using other cladding materials, so long as the conductivity of the cladding is reasonably well known. As part of our analysis, we consider the likely variation in thermal conductivity values for C51000 phosphor bronze caused by legitimate variations in composition.

Arginine (Arg) and glutamine (Gln) utilization is greatly increased during catabolic stress. While the supply of both amino acids has been advocated in this situation, arginine administration is possibly associated with deleterious effects. From a metabolic point of view, these two amino acids are reciprocal precursors via ornithine aminotransferase (OAT). We hypothesized that OAT plays a key role in the interconversion between Arg and Gln. To test this hypothesis, we evaluated the influence of OAT activity in a model of septic shock induced by intraperitoneal injection of lipopolysaccharide (LPS) in wild-type (WT) and transgenic mice overexpressing OAT (OAT) in the liver, kidney and intestine, i.e. the three main organs of OAT expression. Plasma and tissue amino acid concentrations and tissue OAT expression and activity were measured. Five hours after LPS injection, WT and OAT mice showed a similar response to LPS in terms of inflammatory cytokine production and protein catabolism, suggesting that the interconversion between Arg and Gln through this pathway remains limited. Endotoxemia led to a significant decrease in plasma Orn levels and an increase in liver Orn levels. Of note, Orn levels were always lower in OAT mice. While only plasma Arg and Gln remained unaffected by LPS treatment, hepatic Gln was significantly increased without any difference between the two genotypes. In this model of early endotoxemia, arginine and glutamine maintained their metabolic homeostasis. Our results show an inhibition of OAT activity and expression in the liver following LPS treatment. These data highlight the importance of OAT in ornithine metabolism, especially in the liver, and suggest a post-transcriptional regulation of OAT by LPS in the liver.

Tecamax® SRP (self-reinforced polyphenylene) is a new commercially available amorphous polymer which is suitable for use at cryogenic temperatures. It has a high tensile strength (210 MPa at room temperature), resulting from the molecular structure of the polymer rather than by the addition of reinforcing materials. We have measured the thermal conductivity between 60 mK and 280 K. We find that the conductivity below 10 K is similar to, but lower than, most amorphous materials, and the material offers a good combination of low conductivity at low temperatures and high tensile strength. Our results suggest that the material may in fact have a small crystalline component, which may be a partial explanation for the low conductivity. Above 10 K, the temperature dependence of the conductivity is different from most amorphous materials. We are unaware of previous measurements of the thermal conductivity of this material, even at room temperature.

The selenium content in fruit and vegetable samples from two regions in Portugal were analysed using hydride generation atomic fluorescence spectrometry (HG-AFS) and radiochemical nuclear activation analysis (RNAA) – two analytical methods with very low limits of detection. The lower detection limits of HG-AFS, 3 μg kg −1 and 8 μg kg −1 (according to conditions used for digestion), and for RNAA, 10 μg kg −1 , meant that it was possible to determine selenium in samples previously analysed using the replicate sample instrumental nuclear activation analysis (RSINAA) with a higher detection limit associated. The results obtained with the HG-AFS method were similar to those obtained using either RNAA or RSINAA, although in the case of RSINAA significant differences were found in three samples. The good accuracy and increased sample throughput, together with the relatively lower equipment and operating costs make HG-AFS the optimum of the three methods for determining trace amounts of selenium. Values obtained by HG-AFS were from 0.03 μg in tomato to 3.1 μg in cabbage (100 g fresh weight). Based on our results, the contribution of the analysed vegetables and fruits to the daily selenium intake was 1.80 μg per person per day for the Portuguese population.

Selenium daily intake was determined for two small groups of the Portuguese population, based on the analysis of duplicate diet portions. The total amount of food ingested during a day was collected for 18 workers of the Technological and Nuclear Institute (ITN-Sacavem) and for 6 females of Reguengos de Monsaraz, a small town in the south-eastern hinterland. The average selenium daily intake was 43 ± 20 and 32 ± 13 μg per person, respectively, both lower than the Recommended Dietary Allowance (RDA) of 55 μg day−1. Selenium in diet samples was determined by replicate sample neutron activation analysis (RSINAA). The method was considered accurate for the selenium determination.

The replicate sample instrumental neutron activation method was optimized and used for the deter- mination of selenium in foodstuffs. The method was reli- able, yielding accurate results. Lower detections limits were obtained after each successive irradiation. Different irradiation conditions were used depending on the type of sample. For samples with higher selenium contents (meat, fish, eggs), the measured selenium in the first replicate is in all cases larger than the detection limit, but a better accu- racy was obtained with a larger number of replicates (2-3 replicates). For samples with extremely low selenium contents (vegetable samples), at least seven replicates were necessary to obtain a concentration value two times larger than the detection limit.

Pitch-bonded graphites are among the best known thermal insulators at sub-kelvin temperatures, but are very good conductors at higher temperatures. This makes them ideal for mechanical supports which must provide good thermal isolation at an operating temperature below 1 K, but must have good conductance at higher temperatures to aid in initially cooling down an instrument (a “passive heat switch”). One type of graphite, AGOT, has been known as having the lowest thermal conductivity below 1 K not only among graphites, but also compared with any other material. It is, however, no longer available. We have carried out thermal conductivity measurements at temperatures between 60 mK and 4 K on a proposed replacement, POCO AXM-5Q graphite, as well as a sample of AGOT graphite. Our measurements show that both graphites have a difference of about six orders of magnitude in conductivity between room temperature and 100 mK, but that AGOT graphite is not as good an insulator as previously believed. We conclude that AXM-5Q graphite is not only a suitable replacement for AGOT, but in fact is somewhat superior.

In this paper we report about the properties of Neutron Transmutation Doped (NTD) Ge in magnetic fields, focusing on the electrical conduction properties and magnetoresistance, in view of a use as sensors for bolometers in magnetic field. Samples of two different doping density were studied in magnetic field up to 5 T and temperature down to 65 mK. NTD sensors show a reproducible gigantic magnetoresistance that leads to an enhancement of their sensitivity to temperature variations. We discuss preliminarily the possible use of NTD sensors in magnetic field in particle detector developments, in particular for the KATRIN experiment.

At very low temperatures, the tunnelling theory for amorphous solids predicts a thermal conductivity κ α Tm, with m = 2. However, most of the data in the literature in the temperature range 0.1–1 K report an m

The specific heat of Torlon has been measured in the 0.15–4.2 K temperature range. Data below 1 K can be represented by c ( T ) = P 1 T 1+ δ + P 2 T 3 , with P 1 = (5.41 ± 0.08)·10 −6 J K −(2+ δ ) g −1 , P 2 = (2.82 ± 0.03) ·10 −5 JK −4 g −1 and δ = 0.28 ± 0.01, as predicted by the tunnelling theory. Above 1 K, the behaviour of c ( T ) is similar to that of other amorphous materials and can be expressed as: c ( T ) = P · T Ω with P = (2.68 ± 0.07)·10 −5 JK Ω +1 g −1 and Ω = 3.32 ± 0.02.

Neutron Transmutation Doped (NTD) germanium thermistors, cut from metallized wafers, are useful in bolometry. The rise time of a bolometer depends on its heat capacity. We report measurements on the heat capacity of two NTD Ge wafers down to 24 mK temperatures. Both wafers were neutron irradiated and annealed, one of them had in addition undergone a boron implantation and metallization process. For the non-metallized wafer we found a Sommerfeld constant γ = 7.52·10−7 J K−2 cm−3. A comparison between the two wafers showed an excess heat capacity in the metallized wafer. For example, at 24 mK temperature, the specific heat of the metallized afer is more than twice the value of the non-metallized one.

We report about the measurement of the electric characteristics of some NTD Ge thermistors at temperatures down to 25 mK. The dopant concentration is around 6 × 10 16 cm - 3 , producing a material of characteristics close to the metal-to-insulator transition. Fitting the ρ ( T ) characteristics with a variable exponent p Mott's law, a p around 0.6 was obtained. This result confirms the hypothesis of a dependence of p on the doping level.

Selenium contents in the Portuguese (mainland) territory, resulting from a few environmental studies held since 1990 using lichens, vascular plants, soils and air particulate matter (APM), are presented and discussed herein. Values for Se in soils, epiphytic lichens and higher plants are within the typical ranges found in the literature. Compared to vascular plants, lichens display higher contents at the same locations. In what concerns Se in airborne particulates, all surveyed sites show values that are typical of urban areas. In two of such sites – Monchique and Carregado – Se concentrations in transplanted lichen thalli of the Parmelia genus (mostly, Parmelia sulcata Taylor) were compared to the results obtained from airborne matter, and a good correlation was found for the corresponding data-sets at either location. Other than the degree of association, it is especially noteworthy that the lichen transplants appear to accumulate much more Se at Monchique (a remote, rather clean site) than at Carregado (in the immediate vicinity of an oil-fired, power plant), even if its amount in the atmosphere is lower at the former location.

Torlon is an organic polymer (polyamide-imide) which exhibits room temperature good mechanical and thermal properties and high chemical resistance. The thermal conductivity of Torlon 4203 was measured in the range of temperature 4.2–300 K. These data complete existing measurement in the temperature range 0.1–5 K. The thermal conductivity shows a linear behavior between 30 K and 250 K and a plateau, typical of many amorphous materials, around 7 K.

We report data of thermal conductivity between 30 and 150 mK of three different types of commercial copper, before and after a thermal treatment of the samples. The measurements show that both purity and thermal treatment strongly influence the value of thermal conductivity. Data show a strict linear dependence on the temperature of the thermal conductivity.

Other than their inherent accuracy, analytical robustness and nondestructive features, instrumental neutron activation analysis (INAA) and particle-induced X-ray emission (PIXE) are both multi-elemental techniques that complement – and partially overlap – each other with respect to a vast majority of elements of interest in environmental studies and life sciences at large. Analytical accuracy notwithstanding, INAA and PIXE ask for different sample-preparation procedures and rely on dissimilar energy-related profiles, which can lead to some divergence in their operational outputs. Especially interesting are the elements determined by either technique, in that they can provide what one might call an index of intrinsic reliability as to an elemental pool. This paper presents an evaluation of the relative performance of INAA and PIXE on measurements in atmospheric biomonitors, namely epiphytic lichens of the Parmelia genus. The study is based upon 4 elements – Fe, Mn, Rb (customary crustal references) and K (an indicator of physiological status) – in lichen samples from 58 sites in mainland Portugal. Distribution-free statistics – rank-order correlations and enhanced-sign tests – were used for checking the degree of association between concentration patterns (variables) and any significant differences between individual values (variates), respectively. The results show that (i) for all elements, the area-wide patterns by either technique display similar trends; and (ii) for all elements but rubidium, no statistically sound evidence for relative bias – consistently higher or lower values by one technique – could be found. As far as this investigation goes, the techniques may be used interchangeably for determining Fe, K and Mn in Parmelia spp. samples.

Purpose of this experiment was to select the best material for the construction of thermal links aiming at cooling down sensitive masses of the order of 100–1000 kg for the detection of rare decays and gravitational waves. We report on the technique used to measure the thermal conductivity at very low temperatures (down to 30 mK) of three different types of copper, before and after a thermal treatment of the samples. The most conductive copper was used for the thermal link of the CUORICINO experiment, where a mass of about 60 kg needs to be cooled down to a few mK. The cool down time was reduced by at least one order of magnitude with respect to previous similar experiments. An important contribution to this successful result came also from an improved procedure for controlling the residual heating provided by the conversion from ortho- to para-hydrogen in copper.

At ITN, PM10 and PM2.5 aerosols were collected on Nuclepore® polycarbonate filters of 47 mm diameter, using Gent samplers at 15–17 l/min air flux. Filters were analyzed by INAA and PIXE. The availability of certified filters was very scarce, viz.: (1) fly ash embedded in a methyl cellulose 47 mm foil 10 µm thick, BCR CRM128, (2) particle-size reduced air particulate matter (APM) to simulate PM2.5 aerosol matter deposited on a 47 mm polycarbonate filter membrane, NIST SRM 2783. The high price and scarcity of APM standards did not permit their frequent use for analytical quality control. At ITN, to control the filter results' accuracy, the chemical elements potassium, iron and zinc, determined by both techniques, were systematically compared. After a few improvements introduced in INAA, this technique was now considered at ITN as the reference technique in air particulate measurements. Comparison of INAA to PIXE was discussed. Compared to previously reported situation it was concluded that the results were in better agreement for iron and zinc, and potassium values were still biased to the same extent as before.

Introduction et but de l’etude Le maintien de la masse proteique musculaire depend de l’equilibre entre anabolisme et catabolisme. La rupture de cet equilibre entraine une perte de masse musculaire voire, si elle est durable, une atrophie, caracteristique des situations hypercataboliques. L’endotoxemie par injection d’endotoxine (LPS) et le traumatisme crânien (TC) chez le rat sont deux modeles classiques de catabolisme. Le modele de TC reproduit les differentes perturbations metaboliques observees chez les patients en situations hypercataboliques. En revanche, l’injection de LPS engendre un etat septique plus modere entrainant une perte proteique par diminution des syntheses. Cependant, il n’existe pas d’etude ayant compare ces deux modeles, ce qui permettrait de caracteriser leurs niveaux cataboliques et de choisir le modele le plus approprie pour tester des strategies nutritionnelles innovantes. Materiel et methodes Vingt rats mâles Sprague-Dawley (8 semaines 200–220 g) ont ete randomises en trois groupes, soit pour recevoir une alimentation standard ad libitum (groupe temoin, n = 4), soit une nutrition enterale (Sondalis HP energyO, NE) et subir un TC (groupe TC, n = 8) ou une endotoxemie (groupe LPS, n = 8). Apres une semaine d’acclimatation, les animaux, devant recevoir une NE, ont subi une gastrostomie. A j0, les rats ont subi soit un TC par percussion hydraulique au niveau du cortex temporoparietal droit, soit une injection intraperitoneale de LPS d’ E. coli (3 mg/kg). A j1, les rats ont recu la NE en continu en augmentant progressivement le debit (25 % a j1, 50 % a j2, 100 % [290 kcal/kg/j] a j3 et j4). A j5, les animaux ont ete euthanasies. L’evolution ponderale, le bilan d’azote et le rapport 3-methyl histidine (3MH)/creatinine ont ete mesures. Statistiques : test non parametrique de Mann et Whitney. Resultats et analyse statistique Le poids des animaux a chute des j1 dans les deux modeles (TC : 206 ± 5 g contre temoin : 281 ± 8 g ; p = 0,0095 et LPS 205 ± 4 g contre temoin : 281 ± 8 g ; p = 0,004). Les resultats de bilan azote sont rapportes dans le Tableau 1 . Le rapport 3MH/creatinine augmentait significativement dans les deux modeles cataboliques par rapport au groupe temoin des j1 pour attendre un pic a j2 (TC : 0,054 ± 0,003 contre temoin : 0,045 ± 0,001 ; p = 0,0095 et LPS : 0,074 ± 0,003 contre temoin : 0,045 ± 0,001 ; p = 0,004). Conclusion Le LPS entraine une proteolyse musculaire accrue, illustree par l’augmentation du rapport 3 MH/creatinine, plus importante que celle observee dans le TC. Le caractere longitudinal de notre etude permet d’observer que, 5 jours apres l’agression, les rats agresses ne sont plus en situation d’hypercatabolisme, mais plutot en phase de recuperation. Le moment le plus approprie pour etudier les aspects mecanistiques de l’hypercatabolisme dans ces deux modeles est le 3 e jour apres l’induction de l’agression.

The CUORE experiment projects to construct and operate an array of 1000 cryogenic thermal detectors of TeO2, of a mass of 760 g each, to investigate rare events physics, in particular, double beta decay and non baryonic particle dark matter. A first step towards CUORE is CUORICINO, an array of 62 bolometers, currently being installed in the Gran Sasso Laboratory. In this paper we report the physics potential of both stages of the experiment regarding neutrinoless double beta decay of 130Te, WIMP searches and solar axions., Comment: 36 pages, 5 figures. Submitted to Astrop. Phys

We have studied the low temperature thermal properties of a polypropylene copolymer (PP): thermal conductivity (between 0.1 and 4 K), specific heat (between 0.06 and 1 K) and thermal expansion (from 4.2 K to room temperature). Both the thermal conductivity and the specific heat temperature data were interpreted using the tunnelling model for phonon scattering. The measured thermal properties show that PP is suitable for use as thermal insulating support material in cryogenic devices.