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La esteatosis hepática metabólica (EHmet o MASLD) hace referencia a un amplio espectro de manifestaciones hepáticas que incluyen desde la esteatosis simple, con curso generalmente benigno, hasta formas con mayor riesgo de progresión, como la esteatohepatitis, o fenotipos de hepatopatía avanzada como la cirrosis o el hepatocarcinoma. La prevalencia global del MASLD está en aumento, en paralelo a la del síndrome metabólico, siendo los principales grupos de riesgo para la enfermedad los pacientes con comorbilidad cardiometabólica. Los avances en las técnicas de diagnóstico no invasivo permiten identificar en estas poblaciones de riesgo los casos con un mayor riesgo de progresión y eventos clínicos. El manejo de los pacientes con MASLD se fundamenta en la modificación del estilo de vida. No existen actualmente fármacos con indicación aprobada para el tratamiento del MASLD, por lo que es crucial optimizar el manejo terapéutico del síndrome metabólico y el riesgo cardiovascular en estos enfermos.

La esteatosis hepática metabólica (EHmet o MASLD, por sus siglas en inglés) engloba un amplio espectro de afectación hepática que oscila desde la esteatosis simple hasta la esteatohepatitis, fibrosis y cirrosis. Actualmente es la hepatopatía crónica más frecuente a nivel mundial, y se prevé que se convierta en la primera causa de insuficiencia hepática y trasplante hepático en Europa en los próximos años. Además, la MASLD es una enfermedad multisistémica, cuya principal causa de morbimortalidad es la enfermedad cardiovascular, por lo que tiene amplias implicaciones sociales y económicas, representando un gran desafío para la salud pública mundial. En esta actualización resumimos aspectos actuales relevantes sobre la patogenia, historia natural y manejo de la MASLD.

Estudiar la relación entre desnutrición y disfagia en pacientes con ictus.

Halogenoethane derivatives are known to exhibit different polymorphs involving a different translational, orientational, and conformational order. The 1,1,2,2-tetrachloroethane (Cl2HC–CHCl2) exhibits a normal pressure orthorhombic phase β (space group P212121with Z= 8 and Z′ = 2), formed by molecules with one of the two gaucheconformations. At high pressure, the stable polymorph is known to be monoclinic (space group P21/c, with Z= 2 and Z′ = 0.5), phase α, in which only the transconformer appears. In this work, we demonstrate the existence of a normal pressure metastable polymorph, phase γ, for which the two gaucheconformers show up in the asymmetric unit of a monoclinic (space group P21/cwith Z= 8 and Z′ = 2) structure. The new phase γ is obtained by recrystallization upon heating the glass obtained after quench of the melt. It displays shorter type II Cl···Cl contacts than the high-pressure phase α due to attractive and directional interactions.

Los dispositivos supraglóticos forman parte esencial en el manejo de la vía aérea difícil. El objetivo del presente estudio fue comparar las características de la intubación con fibrobroncoscopio a través del dispositivo Air-Q®versus la mascarilla laríngea Fastrach™ (ML-Fastrach™) por residentes de anestesia en maniquís.

In this paper we have analyzed different factors that affect the subject “Prevention and Safety I” evaluation, within the Building Degree from the Polytechnic University of Madrid and its influence in its students’ learning, in order to establish guidelines for improvement in the evaluation. This paper reflects the influence in the evaluation of the base the students already have, the student's perception of the evaluation and the kind of evaluation made. With the results obtained, we have reviewed the teaching planning for the next year, in order to improve the learning objectives fulfilment.

The new European Higher Education Area (EHEA) involves a change in the way of understanding learning and the teacher's work. In this field, assessment is a very important aspect in education. It influences determinedly in the process of helping and encouraging the students to learn and understand their progresses in learning. This paper shows, from the results obtained in the subject “Concrete as a Structural Material”, of fourth grade in Building Degree, the factors which affect the teaching-learning process through assessment.

Low‐molecular weight cyclic alcohols as cycloheptanol (C7H14O, hereinafter referred to as cC7‐ol) and cyclooctanol (C8H16O, cC8‐ol) are prototypical materials displaying OD phases which, under fast cooling give rise to orientational glasses (OG). In addition to the ubiquitous α‐relaxation of canonical glasses, several secondary relaxations appear for the mentioned systems (βand γfor cC8‐ol and βfor cC7‐ol). The intramolecular character of these secondary relaxations for these materials as well as their mixed crystals was highlighted at temperatures close but above the glass transition. For lower temperatures the low values of dielectric strength makes difficult to account for the relaxation times obtained from the permittivity losses and, thus in this work we present a data analysis based on the Kramers–Kronig relations which connect the real and imaginary parts of dielectric permittivity and shows up a new method to make evident the existence of such secondary relaxations as well as to avoid phenomenological equations for determining the relaxation time.

Patterns of relative and absolute stability in parental behaviour with children and adolescents are reported. The sample comprised 523 youth (58.7% girls). Data were collected at three time periods: T1 (Mage = 11.1 yr.), T2 (Mage = 12.2 yr.), and T3 (Mage = 13.2 yr.), each separated by one year. According to children's reports, relative consistency was moderate in both mothers and fathers, particularly as regards communication and strict control. In contrast, as children got older, parental rearing practices related to strict control and hostility decreased. There was a similarity between fathers and mothers in terms of relative and absolute stability. Relative stability was affected by the child's sex, the parenting variable, and the time period; however, the patterns of absolute stability reveal no differences by sex.

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Synthetic monoclinic orpiment was recrystallized by annealing the glass at 523 K for 1 year. The apparent heat of fusion of orpiment at Tfus 601 K (onset) was found to depend linearly on the ratio V/m(V inner volume of the sample pan, m in-pan sample mass) because of partial sublimation. This gives fusH 131 J g-1if V/m 0 and the specific volume of the vapor phase v(v) 190 cm3g-1if fusH 0 at the conditions of the orpiment−liquid−vapor triple point. Lattice parameters of orpiment and liquid density were measured in the 283−393 K and 750−1250 K ranges, respectively. Subsequent specific volume values were used to calculate the slope dp/dT(53 MPa K-1) for the orpiment−liquid equilibrium curve of the As2S3p−Tdiagram.

The experimental systems studied are the five methylchloromethanes [(CH3)4-nCCln, n = 0, ..., 4] and seven of their binary combinations, the accent being on the thermodynamic mixing properties in the plastic crystalline (orientationally disordered) state with its three forms (rhombohedral, face-centered cubic and simple cubic). It is demonstrated that a uniform description can be given of the thermodynamic excess properties characterized by a uniform temperature (420 K) of enthalpy/entropy compensation. The magnitude of the excess properties is related to volumetric mismatch between the components of a system, and, to a relatively small extent, to the dipolar nature of the molecules.

The polymorphism of bromotrichloromethane (CBrCl3) has been investigated by X-ray powder diffraction and high-pressure density experiments. Phase transitions as a function of temperature and pressure between the different phases have been characterized at normal pressure as well as at high pressures (up to 300 MPa). From the p−v−T diagram (and the derived p−T diagram) the volume variations at the transition points have been calculated and compared with those obtained by means of X-ray powder diffraction characterization. Special attention is given to the lattice symmetry of the orientational disordered phase II, characterized as rhombohedral (a = 14.639(8) Å, α = 89.44(1)° at 240.2 K). The existence of a glass transition from the monoclinic low-temperature stable ordered phase (III) to its nonergodic state (associated with the freezing of exchange positions between Cl and Br atoms) is analyzed in terms of the asymmetry of the intermolecular interactions, and a new “fingerprint” for the glass transition is proposed on the basis of the aspherism index. Lattice parameters as a function of temperature were determined in order to build up the thermal expansion tensor.

The polymorphism of cyclopentanol (C5H10O) has been further investigated by X-ray powder diffraction experiments and it has been found to agree with the most recent thermodynamic study [J. Chem. Thermodyn. 1995, 27, 953]. In addition to the previously reported orientationally disordered hexagonal phases I and II, the lattice symmetry of the low-temperature ordered phases III and IV have been determined by means of pattern-matching analyses both as monoclinic with Z = 24 (Cc and C2/c, respectively). The patterns revealed no significant differences between phases III and IV and the transition between both phases was found through careful determination of the variation of the lattice parameters as a function of the temperature. The strength of intermolecular interactions as well as the anisotropy in the solid phases has been analyzed by the study of the isobaric thermal-expansion tensor and the results are discussed in the light of previously reported literature covering dynamics disorder.

ABSTRACTAmong the toxins that Staphylococcus aureusis able to secrete, bi-component toxins named leukotoxins target specifically leukocytes, mainly phagocytic cells. Isolates from cows, goats and ewes with mastitis were selected on the basis of the presence or not of the genes encoding the recently described LukM/LukF'-PV leukotoxin. Of the 128 isolates tested, 126 had moderate to high leukotoxic activity to bovine polymorphonuclear cells (PMN). The supernatants of lukM-positive isolates were much more leukotoxic than the supernatants of lukM-negative isolates: mean leukotoxic titers were 122 versus 20 and 581 versus 26 for isolates of bovine and caprine origin, respectively. Among lukM/lukF'-PVpositive isolates, those of caprine and ovine origins were more leukotoxic than were isolates of bovine origin (P< 0.01). The two most abundant proteins in the culture supernatant of a highly toxic isolate were purified and identified as the two components of LukM (LukM and LukF'-PV) on the basis of their molecular mass, N-terminal amino acid sequence, and high synergistic activity. LukM/LukF'-PV induced the flattening of bovine PMN at a concentration as low as 3.6 ng/ml (0.1 nM). A higher concentration (18 ng/ml) was necessary to produce the same effect on caprine or ovine PMN. Affinity-purified antibodies to LukM or to LukF'-PV neutralized the leukotoxic effect of all the culture supernatants. They neutralized with the same efficiency the toxic activity of supernatants from lukM/lukF'-PV positive or negative isolates. These results establish that LukM/LukF'-PV is very active on PMN of ruminants and suggest that this leukotoxin could be the most active leukotoxin produced by mastitis isolates. They prompt further studies to delineate the contribution of LukM/LukF'-PV to the pathogenesis of mastitis in ruminants and the protective effect of antibodies to this leukotoxin.

The preparation and characterization of the unstable-in-air cubic solvate C60·12BrCCl3 (a = 27.591(3) Å) and the air-stable hexagonal solvate C60·2BrCCl3 (aH = 10.16(3) Å, cH = 10.89(7) Å) are described. Results are compared with those for parent C60 solvates and discussed in terms of potential superconducting properties.

The polymorphism of 2,2-dichloropropane ((CH3)2CCl2) has been further investigated by both thermal and X-ray powder diffraction experiments. From the former the phase transitions between the different phases have been characterized at normal pressure as well as at high pressures (up to 200 MPa). From the p−T slopes of the two-phase coexistence lines, the volume variations at the transition points have been calculated and compared with those obtained by means of X-ray powder diffraction characterization. The existence of two low-temperature stable ordered phases (III and II), one high-temperature orientationally disordered phase (rhombohedral, Ib) and one additional monotropic orientationally disordered phase Ia, has been confirmed. The structure of the low-temperature ordered phase II has been determined by X-ray powder diffraction and Rietveld profile refinement as monoclinic C2/c, with lattice parameters a =10.6402(3) Å, b = 5.4074(2) Å, c = 10.7295(3) Å, and β = 116.274(3)° at 175.2 K. The strength of intermolecular interactions as well as the anisotropy have been analyzed by means of the thermal-expansion tensor.

The trimorphism of (CH3)3CCl, a member of the (CH3)4-nCCln series, is reexamined as a function of the temperature and pressure. Its topological p−T diagram is constructed resorting to the available thermodynamic and crystallographic data for the four observed crystalline solids and the data extrapolated from binary phase diagrams sharing compounds of this series. The p,T coordinates of the five stable triple points are calculated together with the slopes of the two-phase equilibrium curves. Through these results, the uncharacterized phase IV (a high-pressure orientationally disordered stable phase) is shown to coincide with the rhombohedral phase (R) which is the orientationally disordered stable phase for the members with n = 2, 3, and 4 at ordinary pressure. In addition, the existence of a isomorphous high-pressure R phase is postulated for the first member [neopentane, (CH3)4C] of the series.

Triclinic C60·2ferrocene, which melts peritectically at 495 K (ΔπH = +50 J g^-1), can form by direct union of its components with a negative excess volume of −68 ų per formula unit, although the enthalpy of deferrocenation into fcc C60 and ferrocene vapor is virtually the same as for the sublimation of pure ferrocene. C60 solubility in molten ferrocene is about 0.5 mol % at 495 K. The strong anisotropy of the thermal expansion tensor illustrates the anisotropy of intermolecular interactions inferred from the crystal structure in the 90−300 K range. The existence of nonnegligible interactions is corroborated by the persistence of the crystalline local order in the amorphous phase obtained by grinding, which reverts to the initial crystalline phase upon heating. Thus, from the thermodynamic and structural points of view, C60·2ferrocene behaves as the C60·2S8 solvate.

The phase diagram of the two-component system 2-methyl-2-chloropropane ((CH3)3CCl) and 1,1,1-trichloroethane ((CH3)CCl3) has been determined by means of X-ray powder diffraction and thermal analysis techniques from 180 K to the liquid state. The isomorphism relationship between the stable orientationally disordered (OD) face-centered cubic (FCC) phase of (CH3)3CCl and the metastable OD FCC phase (monotropic behavior with respect to the OD rhombohedral stable phase) of (CH3)CCl3 has been put into evidence throughout the continuous evolution of the lattice parameters and the existence of the two-phase equilibrium [FCC + L] (L = liquid) for the whole range of composition. This equilibrium interferes with a rhombohedral (R) plus liquid ([R + L]) equilibrium, giving rise to a peritectic invariant. The validity of the well-known crossed isodimorphism formalism has been experimentally demonstrated, and a subsequent thermodynamic assessment has been performed to obtain the excess properties of the OD FCC and R phases. In addition excess properties of the R and FCC phases are compared, and the existence of short-range orientational order for the R phase is inferred.

Crystals of a C60 1:1 solvate (I-centered cubic, a = 23.284(2) Å) were grown by evaporating solutions of C60 in H2CCl2 at room temperature. Solvate crystals are not air stable and spontaneously transform into a hexagonal polymorph of C60 (a = 10.044(5) Å, c = 16.404(8) Å, c/a = 1.633(2)) when extracted from the mother liquor at room temperature. Although solvate formation entails almost no volume change, desolvation enthalpy (59.2 kJ/mol of solvent) is found to be about twice as high as sublimation enthalpy for pure H2CCl2.

Single and 10-fold-twinned crystals of the C60 1:1 solvate formed with 1,1,2-trichloroethane were examined by means of scanning electron microscopy, X-ray diffraction, and differential scanning calorimetry and thermogravimetry. Solubility of C60 in 1,1,2-trichloroethane was found to be 130 ± 10 mg per liter of solution in equilibrium with solvate crystals at 296 ± 2 K. The lattice metrics of the solvate is orthorhombic (a = 10.164(3) Å, b = 31.390(6) Å, c = 10.130(4) Å, β = 90.00(2)°), with axis c as a twin axis, although the symmetry is monoclinic (space group P21/n). The solvate forms with a negative excess volume (−58 ų per formula unit), and its packing coefficient (0.76) is higher than that for close packing of hard spheres. On heating, desolvation into cubic C60 and TCAN vapor occurs in one step at 436 K (onset) with a related enthalpy, +48 kJ per mole of solvate, close to the sublimation enthalpy for pure solvent. On aging at room temperature in the dark, no degradation of big (≈1 × 10−³ mm³) solvate crystals into fcc C60 is observed after 4 years have elapsed.

An experimental reinterpretation together with a thermodynamic analysis of the two-component system (CCl4)+(C(CH3)4) has been performed. The 35-year-old specific heat diagrams obtained by adiabatic calorimetry have been revised in order to remove the inconsistencies of the tentative experimental phase diagram. The fact that the two components of the system do not have the same ODIC form was ignored 30 years ago and, at present, it has been considered. From a thermodynamic point of view the two-component system is a very nice example of crossed isodimorphism: two ODIC+liquid loops crossing each other give rise to a three-phase equilibrium. The thermodynamic information of the excess magnitudes is wide enough to perform a complete and realistic thermodynamic analysis. Likewise, the excess thermodynamic magnitudes in the ODIC states have been well explained by means of the quasi-subregular solution model including a compensation law.

A lyophilized one-step kit of Mab FC-5.01, reactive with human breast cancer and malignant melanomas, was formulated. A direct method based on the reduction of protein disulphide bridges using 2-mercaptoethanol was used with methylene diphosphonate as the transchelating ligand. The labeled species were analyzed by ITLC thin layer chromatography and high performance liquid chromatography. Labeling efficiency was greater than 90%. Immunoreactivity was assessed on IIB-BR-G cells. 99mTc-labeled Mab FC-5.01 biodistribution and tumor imaging were performed in nude mice bearing IIB-BR-G breast cancer xenografts. At 24 hs accumulation of 99mTc increased in tumor and decreased in blood and most organs in agreement with results of an in vitro cysteine challenge assay. Quality control tests demonstrated that the kit was stable for up to 120 days. Animal studies demonstrated good and specific in vivo tumor targeting.

The experimental systems considered in this paper are isobaric binary plastic-crystalline mixed crystals of neopentane derivatives, and their properties studied are (i) solid−liquid phase behavior and (ii) the thermodynamic mixing properties, actually the excess enthalpy, entropy, and volume. More in particular, 10 systems are considered, nine being face-centered cubic and one body-centered cubic, and their components are derived from neopentane, C(CH3)4, by substituting one or more −CH3 groups by one or more −CH2OH groups and/or one −NO2 or −NH2 groups. The (mean) number of −CH2OH groups per molecule appears to have a dominating influence with regard to melting temperature and degree of compactness. The values of the excess properties vary from system to system, whereas their quotients are system-independent. For the group of fcc systems, the quotient of excess enthalpy and excess entropy (compensation temperature) has the uniform value of 630 K, and the quotient of excess enthalpy and excess volume the value of about 0.5 GPa.

The polymorphism of (CH3)3CCl has been further investigated by both thermal and X-ray powder diffraction experiments. From the former, the phase transitions between the different phases (IV, III, II, I, and L) have been thermally characterized, and in particular, the temperature domain of phase II has been settled to be from 217.9 to 219.8 K by means of Cp measurements. The structure of the lowest-temperature phase IV of (CH3)3CCl has been determined by X-ray powder diffraction and Rietveld profile refinement. The structure, P21/m with two molecules per unit cell, has been found to be isostructural with that of phase II of (CH3)3CCN. The intermolecular interactions in the solid-state phases for (CH3)3CCl as well as for (CH3)3CCN have been analyzed by the study of the isobaric thermal-expansion tensor. The anisotropy of such interactions are discussed in the light of the previously studied dynamics disorder.

Gcd10p and Gcd14p were first identified genetically as repressors of GCN4 mRNA translation in Saccharomyces cerevisiae. Recent findings indicate that Gcd10p and Gcd14p reside in a nuclear complex required for the presence of 1-methyladenosine in tRNAs. Here we show that Gcd14p is an essential protein with predicted binding motifs for S-adenosylmethionine, consistent with a direct function in tRNA methylation. Two different gcd14 mutants exhibit defects in cell growth and accumulate high levels of initiator methionyl-tRNA (tRNAiMet) precursors containing 5' and 3' extensions, suggesting a defect in processing of the primary transcript. Dosage suppressors of gcd10 mutations, encoding tRNAiMet (hcIMT1 to hcIMT4; hc indicates that the gene is carried on a high-copy-number plasmid) or a homologue of human La protein implicated in tRNA 3'-end formation (hcLHP1), also suppressed gcd14 mutations. In fact, the lethality of a GCD14 deletion was suppressed by hcIMT4, indicating that the essential function of Gcd14p is required for biogenesis of tRNAiMet. A mutation in GCD10 or deletion of LHP1 exacerbated the defects in cell growth and expression of mature tRNAiMet in gcd14 mutants, consistent with functional interactions between Gcd14p, Gcd10p, and Lhp1p in vivo. Surprisingly, the amounts of NME1 and RPR1, the RNA components of RNases P and MRP, were substantially lower in gcd14 lhp1::LEU2 double mutants than in the corresponding single mutants, whereas 5S rRNA was present at wild-type levels. Our findings suggest that Gcd14p and Lhp1p cooperate in the maturation of a subset of RNA polymerase III transcripts.

The experimental binary phase diagram between the pure components 2-methyl-2-nitro-1-propanol(MNP) and 2-hydroxymethyl-2-methyl-1,3-propanediol(PG) has been established from 273 K to the liquid state, using thermal analysis and X-ray powder diffraction at several temperatures.The main features of this phase diagram, such as, the miscibility and the molecular interactions in plastic phase are discussed on the basis of the similarity in shape and size of the molecules. In addition, other binary systems, previously reported by us, between neopentane-like compounds which present a comparable situation are considered.

The experimental two-component phase diagram between the orientationally disordered crystals 2-amino-2-methyl-1,3-propanediol (AMP) and 1,1,1-tris(hydroxymethyl)propane (PG) has been established from room temperature to the liquid state using thermal analysis and X-ray powder diffraction techniques. The intermolecular interactions in the orientationally disordered mixed crystals of the mentioned system and other related two-component systems are discussed by analyzing the evolution of the packing coefficient as a function of the the composition. A thermodynamic analysis of the presented phase diagram and the redetermined AMP/NPG (2,2-dimethyl-1,3-propanediol) is reported on the basis of the enthalpy–entropy compensation theory.

Several techniques were used to characterize the polymorphism in polyalcohol 2-amino-2-methyl-1, 3 propanediol, (CH2OH)2CH3C NH2, which exhibits a solid crystalline plastic phase. Three equilibrium and two nonequilibrium states were determined in the temperature range from 0 to 150 °. One of the nonequilibrium states reveals characteristics of a glassy crystal, a frozen state from the plastic phase. Although different results agree with this affirmation, further analysis is needed to verify the glassy crystal definition of Suga and Seki [68Ada].

Summary: The anodic voltammetric behaviour of pentachlorophenol at a silica gel-modified carbon paste electrode in aqueous solution is reported. Adsorption of the fungicide onto the electrode under open-circuit conditions is followed by application of either differential or square wave voltammetry. The results obtained by differential pulse voltammetry at pH 2.9, with a modifier concentration of 10% and accumulation times of 120 and 300 s, allowed the development of a method to determine pentachlorophenol in the ranges of 1.010−6–1.010−5 and 1.010−7–1.010−6 mol l−1. The relative standard deviation is 2.6% for a concentration of 2.010−7 mol l−1, with a detection limit of 1.810−8 mol l−1 (5 ppb). The effect of other chlorophenols was studied. The results obtained by square wave voltammetry showed a behaviour typical of an irreversible electron transfer. Amplitude, step height and frequency were optimised, taking into account the resolution of the voltammetric response. No improvement in sensitivity was obtained with respect to DPV. Good results were obtained by applying the proposed differential-pulse voltammetric method to the determination of pentachlorophenol in a commercial fungicide.

Prismatic crystals of orthorhombic 1:1 solvate (space group Pnma or Pn21a, α = 31.47 Å, β = 10.07 Å, c = 10.22 Å, Z = 4) are obtained by slowly evaporating trichlorethylene solutions of C60 at room temperature. Decagonal morphologies, i.e. crystals with angles of about 36° between adjacent faces, are also encountered. Although the enthalpy of desolvation, + 51.3 J per gram of solvate (+ 43.7 kJ per mole of solvent), is close to that of sublimation for pure solvent (+ 40.6 kJ mo1-1), the formation of the solvate from its solid components is accompanied with a negative excess volume (-40 Å3 per formula unit).

The packing coefficient is analyzed in orientational disordered phases for a set of series of compounds derived from neopentane [C(CH3)4] by means of the substitution of methyl by other groups such as CH2OH, NH2, NO2and COOH. The packing coefficient, which enables the intermolecular interactions in the mentioned phases to be accounted for, reaches relatively high values when the interactions generated by means of the dynamical hydrogen bonds are present. The variation of the packing coefficient as a function of the molar fraction in two‐component phase diagrams between isomorphous and nonisomorphous orientational disordered phases is also reported in order to understand intermolecular interactions in mixed crystals.

The anisotropy of the intermolecular interactions in the low‐temperature ordered phases of three chemically and structurally related compounds [neopentylglycol, (CH3)2C(CH2OH)2, pivalic acid, (CH3)3C(COOH), and neopentylalcohol, (CH3)3C(CH2OH)], all of which display an orientationally disordered high‐temperature phase, has been shown by means of the isobaric thermal‐expansion tensor. The variation of the directions of the principal components of the thermal‐expansion tensor as a function of temperature, as well as the variation of its principal coefficients, is evidence of the large differences in the intermolecular interactions for each compound; or, more precisely, between the strong intermolecular hydrogen bonds and the weak van der Waals interactions. In addition, the differences in the hydrogen‐bonding schemes expected a priorifrom the molecular structures of the studied compounds have been enhanced. Finally, the volume expansivity as well as the packing coefficient have been analysed in the orientationally disordered high‐temperature phase of each of the three compounds.

The paper gives some comments about the potential use of plastic crystals in energy storage. The main point deals with the possibilities of binary solid solution formation. Three binary phase diagrams in the pentaerythritol series are commented on.

In this work we give the specific heat values of different plastic crystals, determined by AC calorimetry are presented.

This paper reports a home-made AC calorimeter designed forCP measurements on powdered samples. The results of tests with SiC and Al2O3 at constant temperature demonstrated that it is possible to measureCP for powdered samples with the same accuracy as for substances usually analysed by AC calorimetry (liquids and single-crystals).

Abstract: Heat capacity measurements between 293 K and 363 K have been carried out in order to elucidate the different states appearing in 2-amino-2-methyl-1,3 propanediol (AMP) plastic crystal. The results allowed one of them to be identified as a glassy crystal. The changes of enthalpy, entropy and Gibbs free energy thermodynamic functions with temperature have been calculated from the experimental heat capacity values.

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The experimental two-component phase diagram for the plastic crystals tris(hydroxymethyl)aminomethane (TRIS) and pentaerythritol (PE) has been established from 293 K to the liquid state using thermal analysis and X-ray powder diffraction at several temperatures. The miscibility and the intermolecular interactions of the mentioned system and other related binary systems formed from compounds which present also non-isomorphous plastic phases are discussed on the basis of the steric conditions (similarity of the unit-cell dimensions and of the size and shape of the molecules) and of the other factors governing the structural arrangements such as the effects of the orientational disorder. The evolution of the packing coefficient as a function of the composition in each two-component system is analyzed to attain further understanding of the intermolecular interactions in orientationally disordered pure and mixed crystals.

The population-based incidence of rotavirus gastroenteritis in children <5 years of age in Valencia, Spain, over a 1-year period (December 1, 2003, to November 30, 2004) was determined.

By means of X-ray single crystal Weissenberg photographs, the crystal of the low-temperature solid form of 2-methyl-2-nitro-propanol, (CH3)2C(NO2)(CH2OH), has been determined and found to be of the monoclinic type, space group P21/c. The cell constants were refined from X-ray powder diffraction data: a=6.195(3) ?, b=19.116(7) ?, c=16.598(7) ?, and ?= 90.12(2)? with Z= 12. The indexed pattern at 293 K is given.