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Determinar el impacto emocional de la proximidad al trauma y la muerte en enfermeras de urgencias y de UCI mediante las prevalencias de fatiga de compasión (burnouty estrés traumático secundario) y ansiedad. Analizar su relación con variables de tipo sociodemográfico, formativas, laborales y psicológicas.

The composition of a multicomponent aqueous solution containing sugars and salts was studied in order to lower solute uptake during osmotic dehydration of an agar gel. A diffusion cell was used to obtain the effective diffusivity and the main diffusion coefficient of each solute in the presence of the others. The main diffusion coefficients were then expressed as a function of thermodynamic and rheological properties of the solution. The decrease in effective diffusivities was mainly due to the increase in the viscosity of the solution. Addition of texturing agents which increased the viscosity of the solution confirmed this effect.

The composition of the solution defined in Part I of this study was tested and improved to obtain high water loss during the dehydration of an agar gel. This solution was used for osmotic dehydration of meat slices. A mathematical model based on Fick's law of diffusion was used to estimate the time course of the water profile in meat, and water loss versus time. The water diffusion coefficient was expressed as a function of water content in meat. Meat with an intermediate moisture content can be obtained using controlled dehydration times, followed by an equilibration period.

It is reported here that CHO/K1 cells stably transfected with the human (beta)3 AR gene (CHO/K1-(beta)3), grown in the presence of differentiation-stimulating agents accumulate triglycerides. This lipid formation is mediated through the (beta)3 AR, since non-transfected CHO/K1 cells, or cells expressing the human (beta)2 AR, accumulate no significant amount of lipids when grown in supplemented medium. Moreover, lipid production can be inhibited significantly by the (beta) AR antagonist bupranolol. CHO/K1 cells expressing the W64R polymorphism (Trp to Arg polymorphism at position 64 of the human (beta)3 AR), which has been associated with morbid obesity, show increased lipid accumulation as compared to CHO/K1 cells expressing the wild-type (beta)3 AR. Semi-quantitative RT-PCR experiments reveal that a major gene regulating adipocyte differentiation, peroxisome-proliferator-activated-receptor (gamma) (PPAR(gamma)), is expressed in CHO/K1 cells. Concomitantly with the formation of lipid droplets, the expression of PPAR(gamma) mRNA is increased in CHO/K1-(beta)3 cells, but not in non-transfected CHO/K1 cells. We furthermore detected constitutive expression of another adipocyte-associated protein: hormone sensitive lipase, while leptin or uncoupling protein-1 transcripts were not expressed. These data suggest that the frequently used CHO/K1 fibroblasts display several preadipocyte-like features, and that the sole expression of the (beta)3 AR modifies the expression of PPAR(gamma) mRNA in these cells, and induces lipid formation under certain culture conditions.

We present evidence that stimulation of the human beta-3 adrenergic receptor (AR), expressed in Chinese hamster ovary/K1 cells, specifically activates the mitogen-activated protein kinases extracellular signal-regulated kinase (ERK)1 and 2, but not JNK or p38. The extent and kinetics of the ERK stimulation by the beta-3 AR are identical with those of the endogenic insulin receptor. However, insulin augments cellular proliferation, whereas beta-3 AR agonists inhibit proliferation due to the production of cyclic AMP. The pharmacological profile of the ERK activation by the beta-3 AR differs significantly from its activation of adenylyl cyclase. The order of potency and intrinsic activities of both natural ligands, norepinephrine and epinephrine, is inversed between both signaling pathways. In addition, BRL 37344 and propranolol, ligands that act as agonists in the stimulation of cyclase, act as antagonists for ERK activation. The activation of ERK1/2 is sensitive to pertussis toxin, suggesting that the beta-3 AR, in addition to its interaction with Gs, can couple to Gi/o. Furthermore, the activation of ERK by the beta-3 AR is sensitive to PD98059, wortmannin, and LY294002, indicating a crucial role for mitogen-activated protein kinase kinase and phosphatidylinositol-3 kinase (PI3K), respectively. Abeta-3 AR-mediated stimulation of PI3K is confirmed by the observation that the selective agonist CGP 12177A specifically activates protein kinase B. As was observed for the activation of ERK, the activation of protein kinase B is inhibited by preincubation with pertussis toxin and PI3K inhibitors, suggesting that both are a consequence of a Gi/o-mediated activation of PI3K.

A simple model for predicting gas solubilities of O2and CO2at low pressure and near ambient temperature in solutions of salts, sugars, and organic solvents (alcohols, ketones, ethers, aldehydes, etc.) is proposed. It is derived from the Van Laar assumptions and takes account of size differences between molecules in solution by their volumetric fraction. It is a group contribution model where anions and cations are considered as groups and other molecules are treated as in the UNIFAC (UNIQUAC Functional group Activity Coefficients) procedure. Pseudo‐Henry's constants for groups were determined using solubility data in aqueous solutions containing only one salt, one sugar, or one organic compound at 25 °C. The predictive performance of the model was evaluated by comparison with experimental data using multicomponent aqueous salt−sugar mixtures. The model was used to estimate solubilities of oxygen and carbon dioxide in fermentation media.

Aspergillus niger IFO 8541 was found to be an efficient biocatalyst for the biotransformation of ß-ionone into hydroxy and oxo derivatives. The reaction had to be carried out with an inoculum made of about 4 × 107 fresh spores/l and with a preliminary growth period giving at least 3 g/l biomass. The fungus developed in the form of pellets when cultivated as free mycelium; entrapment of the microorganism in calcium alginate beads was an efficient way to mimic this feature in an aerated, stirred bioreactor. The biotransformation was carried out using a fed-batch mode of operation involving sequential precursor addition. ß-Ionone stopped the fungal growth and was converted into metabolites only when the carbon source remained present in the medium; it was fully oxidized after sucrose exhaustion. These conditions allowed recovery of about 2.5 g/l aroma compounds after 230 h cultivation with a molar yield close to 100%.

A simple model for predicting gas solubilities of O2 and CO2 at low pressure and near ambient temperature in solutions of salts, sugars, and organic solvents (alcohols, ketones, ethers, aldehydes, etc.) is proposed. It is derived from the Van Laar assumptions and takes account of size differences between molecules in solution by their volumetric fraction. It is a group contribution model where anions and cations are considered as groups and other molecules are treated as in the UNIFAC (UNIQUAC Functional group Activity Coefficients) procedure. Pseudo-Henry's constants for groups were determined using solubility data in aqueous solutions containing only one salt, one sugar, or one organic compound at 25 °C. The predictive performance of the model was evaluated by comparison with experimental data using multicomponent aqueous salt−sugar mixtures. The model was used to estimate solubilities of oxygen and carbon dioxide in fermentation media.

Biotransformation of β-ionone by Aspergillus niger IFO 8541 was a complex system, due to the low precursor solubility in water (0.88 mol/m³) which gave a two-phase liquid system, its high volatility (vapor pressure 7.2 Pa), and its poor chemical stability. A dynamic model, considering transfers between organic, aqueous, and gas layers, was established. It also took into account the decrease in organic layer area exchange during a process, due to progressive precursor disappearance. Its solving needed separate determination of two parameters. The first-order kinetic constant for chemical degradation, K1, was estimated from side experiments involving a model system at thermodynamic equilibrium; its value was found to be close to 4.17 × 10^-6 s^-1. The volumetric transfer coefficient between gas and aqueous phase was estimated by analogy with results obtained for oxygen transfer. Results obtained demonstrated high liquid−gas transfer rates, while liquid−liquid transfers were severely limited. These data were then used to estimate the true yield of a biotransformation experiment, which was found to be close to unity.

The foaming process was studied in scraped surface heat exchangers (SSHE) under steady-state flow conditions. A model food was used; to ensure foaming, it was subjected to several experiments in batches using a stirred tank. These showed that temperatures up to 50°C improved foaming capacity. Stability of the product was improved when temperature reached the temperature of protein coagulation. Concentrations of starch up to 3 g/100 g increased apparent viscosity and improved stability of the product. In SSHEs foaming yield was similar to that obtained in a stirred tank. Foaming capacity depended on gas flow rate; rotation speed improved foaming capacity up to 1150 rpm. The advantage of SSHE over other rotor-stator mixers is the possibility of controlling the protein denaturing, and the stabilization and pasteurization of the product. Copyright 1993, 1999 Academic Press

The possibility was examined that inhibition of growth of PY815 mouse mastocytoma cells by N6, O2'-dibutyryladenosine 3',5'-cyclic monophosphate (DB cyclic AMP) results from inhibition of c-myc gene expression. Temporary increases in c-myc RNA which occurred soon after DB cyclic AMP treatment and upon removal of the drug were not consistent with direct inhibition of c-myc gene expression by DB cyclic AMP. The increases in c-myc RNA coincided with the passage through, or accumulation of cells in late G 1- early S phase. It is proposed that cyclic AMP may stimulate c-myc gene expression which normally occurs only in late G 1- early S phase in PY815 cells and that cyclic AMP prevents c-myc expression in cells at other phases of the cell cycle by inhibiting their progression past a cyclic AMP-sensitive restriction point in early G 1phase.

Abstract: Fermentations of Xanthomonas campestris, NRRL B-1459, were carried out in a bubble column fermentor (BCF) and in a stirred tank fermentor (STF) to allow comparison of representative variables measured during the microbial growth and the gum production. The microbial growth phase was described by a logistic rate equation where maximum cell concentration was provided by nitrogenous compounds balance. The average value of the maximum specific growth rate was higher in the bubble column (μ M =0.5 h−1) than in the stirred reactor (μ M =0.4 h−1). The upper values of xanthan yield (Y g-x =0.65 kg xanthan/kg glucose; Y O 2−x xanthan/kg oxygen) and specific production rate (q x =0.26 kg xanthan/kg biomass h) were measured when the oxygen transfer coefficient was kept up above 80 h−1 in the STF fermentor. In the bubble column the fermentation achieved in the same culture medium lasts two times longer than in the stirred aerated tank; this was attributed to the low value of the oxygen transfer coefficient (K L a =20 h−1) at the beginning of the gum synthesis phase. The results obtained in the stirred tank were the basis to estimate the optimal biomass concentration which enables to achieve a culture in non-limiting oxygen transfer conditions. Nevertheless, the transfer characteristics were more homogeneous in the bubble column than in the stirred tank where dead stagnant zones were observed. This is of primary importance when establishing fermentation kinetics models.

Abstract: The analytical possibilities offered by long-term irradiation of biological samples in a fission neutron flux filtered by a cadmium screen are examined and the preparation of samples for irradiation is described. This specific activation technique is applied to the determination of molybdenum and nickel in the following three reference substances: human serum, NBS bovine liver and BOWEN’s kale.

A culture technique, based on the growth of a microorganism on inert porous particles (e. g. pozzolano) impregnated and continuously fed with substrate is applied to the growth and spore production ofPenicillium roqueforti. The composition and the feed rate of the medium can be controlled, and the biomass is directly estimated.P. roquefortiexhibits a diauxic growth on the medium containing sucrose and malt extract used, and 1.5 109spores/g pozzolano may be obtained.

A study of the influence of temperature, aeration rate, and substrate water content on sporulation of Penicillium roquefortion buckwheat seeds in a fixed bed reactor is described. Use of an experimental procedure based on a 23factorial design allowed optimum to be determined as 23.5° C for temperature, 0.48 g/g dry matter for substrate water content and 4.42 VVH for aeration rate.

Abstract: Raney nickel catalysts are prepared from Ni−Al alloys. In order to test the influence of the microstructure of the precursor alloys, we prepared homogenized and microcrystallized (NiM)2Al3 alloys with M=Cr, Cu, Fe, Ti, Zr, Ta. Microcrystallized alloys are prepared by meltspinning. Observations were made by scanning and transmission electron microscopies. The as-melted ribbons exhibit a flower dendritic shape with NiAl as a core. An intermediate zone is observed which corresponds to small axial domains according to the peritectic formation of Ni2Al3 (hexagonal structure) from NiAl (b c c). Petals of the flowers are made of domains of Ni2Al3 almost monocrystalline. The size of the domains depends essentially on the cooling rate and on the nature of the dopant.

Internal substrate concentrations were monitored during biotransformation of octanoic acid into 2-heptanone by spores ofPenicillium roquefortii. The fatty acid rapidly enters the spores in its undissociated form, and a Collander-type relation shows that it strongly accumulates in the spore wall and membrane; this accumulation is reversible. The reaction takes place with cytoplasmic substrate concentrations that quickly fall to zero, and the process is limited by octanoic acid penetration into the cells. This entry is accompanied by proton efflux and involves an active transport process with a H+-ATPase system that exhibits Michaelian behavior. The driving force is postulated to be ?pH, which takes a value set by the initial substrate concentration through the stoichiometry of the H+/octanoic acid exchange.

Both growth and sporulation increase linearly according to the initial water content of the solid substrate when Penicillium roquefortii is cultivated on buckwheat seeds. This indicates that water is the limiting factor for fungal development since neither carbon nor nitrogen sources were exhausted during these experiments. This feature validates the concept of available water for fungal growth, defined as initial water content of substrate minus its residual water content when vegetative growth stops. An efficient methodology, based on drawing a regression line of mycelium dry weight production as a function of the initial water content of substrate is presented; it allows estimation of both available water and water content of mycelium. Results show that growth stops when the residual water in the substrate is close to 0.52 g H2O/g initial dry matter, corresponding to a water activity (aw) close to 0.96, and that the initial water content in mycelium is near 76%. Thus, both aw and water content of the substrate have to be taken into account during the course of solid-state cultivations.

Abstract: 2,5-Dimethylpyrazine (2,5-DMP) and tetramethylpyrazine (TTMP) were produced using Bacillus subtilis IFO 3013 grown on soybeans. Solid-state cultivations were carried out either in 100-ml bottles or in a fixed-bed column reactor, both systems being at 27 C. Optimization studies showed that the best way to produce the two above aroma compounds involved two separate processes. 2,5-DMP was obtained using soybeans enriched with 75 g threonine/kg initial dry weight (i.d.w.), giving 0.85 g metabolite/kg i.d.w. after 6 days. TTMP production involved addition of 90 g/kg i.d.w. acetoin to soybeans, and 2.5 g/kg i.d.w. was recovered after 14 days. These results demonstrated the suitability of solid-state cultivation for production of high-added-value compounds.

Water solubilities, activity coefficients, and vapor pressures of some terpenes and terpenoids were determined from two sets of experiments. The first involved liquid−liquid contacting until saturation of an aqueous layer, which gave solubility and activity coefficient at infinite dilution γ^∞. The second set involved stripping a solute from a nonsaturated aqueous solution by an air stream. This last experiment gave the product γ^∞P° from which vapor pressure P° was deduced. Reliability of the results was established from predicted P° values, and data for 12 compounds are now available. Data obtained at 25 °C showed low solubilities (0.037−0.22 mmol/L) and high activity coefficients (10⁵−10⁶) for terpenes, whereas oxygenated monoterpenes exhibited solubilities 20 orders of magnitude higher, in the range of 2−20 mmol/L and 10³−10⁴ for activity coefficients. Vapor pressures ranged from 100 to 550 Pa for terpenes and from 1 to 130 Pa for terpenoids. Attempts to estimate water solubility showed that recent equations in the literature are unable to predict this property with an accuracy better than 140%.

The cultivation of photosynthetic microorganisms in photobioreactors mainly occurs under limitation by radiant light energy transfer at a rate controlled by the total radiant light energy entering the reactor. Consequently, the mean incident radiant light flux onto the reactor is a key technical quantity in both kinetic and energetic studies of such processes. In this paper, a general revised method for determining the incident radiant light flux is proposed using a chemical actinometer, Reinecke's salt. New easy procedures are given for preparing the reactive salt and measuring the photoreaction rate. Additionally, a mathematical model makes it possible to apply the technique to different reactor geometries and lighting systems with no limiting operating conditions for the incident flux. The method gives accurate results and constitutes a simple, general and reliable method for evaluating the maximum performance of photobioreactors. It can also be a tool for developing monodimensional models for simulation.

Plasmocytomas of the temporal bone are extremely rare. In the extensive review of world medical literature I have found only 2 other cases reported. One was that of Cappell and Mathers,1 who stated in 1934 that their case of plasmocytoma of the petrous bone, proved by necropsy, was the first reported. The second case was cited by Fowler2 from Neumann, who described a case of an involvement of the petrous bone, but from the description it was difficult to determine whether the tumor spread throughout the petrous bone or was confined solely to the mastoid process.These plasma cell tumors, or plasmocytomas, may be medullary, when they arise from the bone marrow, or extramedullary, when they develop from other sites, such as the nasal mucosa, conjunctiva, lymph nodes and ovaries. When a tumor arises either in the tonsil or in the humerus, it is not difficult to identify its source

Le cartilage constitue le tissu cible de l’arthrose, mais d’autres tissus peuvent également participer aux phénomènes dégénératifs. Ainsi, le tissu adipeux sécrète des adipokines comme la leptine ou l’adiponectine qui modulent les fonctions des cellules articulaires. Le but de ce travail est de mieux comprendre le rôle du ligament adipeux de Hoffa dans la dégradation du cartilage. Nous avons ainsi étudié la production de leptine et d’adiponectine chez des patients arthrosiques ainsi que les effets des produits de sécrétion du ligament de Hoffa sur les fonctions chondrocytaires. Ces paramètres ont été comparés à ceux observés avec un tissu adipeux standard, à savoir la graisse sous-cutanée.