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A Heras

Publications and source records attributed to A Heras.

8 recordsLinked to original sources
PubMed2006

[Prognostic estimation in critical patients. Validation of a new and very simple system of prognostic estimation of survival in an intensive care unit].

OBJECTIVE: To make the validation of a new system of prognostic estimation of survival in critical patients (EPEC) seen in a multidisciplinar Intensive care unit (ICU). DESIGN AND SCOPE: Prospective analysis of a patient cohort seen in the ICU of a multidisciplinar Intensive Medicine Service of a reference teaching hospital with 19 beds. PATIENTS AND METHOD: Four hundred eighty four patients admitted consecutively over 6 months in 2003. Data collection of a basic minimum data set that includes patient identification data (gender, age), reason for admission and their origin, prognostic estimation of survival by EPEC, MPM II 0 and SAPS II (the latter two considered as gold standard). Mortality was evaluated on hospital discharge. EPEC validation was done with analysis of its discriminating capacity (ROC curve), calibration of its prognostic capacity (Hosmer Lemeshow C test), resolution of the 2 x 2 Contingency tables around different probability values (20, 50, 70 and mean value of prognostic estimation). The standardized mortality rate (SMR) for each one of the methods was calculated. Linear regression of the EPEC regarding the MPM II 0 and SAPS II was established and concordance analyses were done (Bland-Altman test) of the prediction of mortality by the three systems. RESULTS: In spite of an apparently good linear correlation, similar accuracy of prediction and discrimination capacity, EPEC is not well-calibrated (no likelihood of death greater than 50%) and the concordance analyses show that more than 10% of the pairs were outside the 95% confidence interval. CONCLUSION: In spite of its ease of application and calculation and of incorporating delay of admission in ICU as a variable, EPEC does not offer any predictive advantage on MPM II 0 or SAPS II, and its predictions adapt to reality worse.

Adult↗
PubMed2004

Application of MRI to monitor the process of ripening and decay in citrus treated with chitosan solutions.

Chitosan is a biopolymer, which has numerous applications in agriculture and agroindustries. Coating fruit and vegetables with chitosan has some positive advantages for the long-term storage of foods, because the film of chitosan provides a kind of an active package, which allows a gradual release of preservatives, thus inhibiting fungal growth and maintaining the external appearance of the fruit for a longer time In this study, two varieties of citrus, Fortune mandarins and Valencia oranges were coated with Biorend(R) (IDEBIO S.L., Salamanca, Spain) (a compound whose active molecule is chitosan), to investigate its effect on maturity, decay, and damage, and therefore, to find a better method for the long term storage of fruit. The effect of chitosan as a fungistatic was also studied. To that end, the fruit was maintained in a damp storage room, ideal conditions for the growth of fungi. The magnetic resonance imaging (MRI) technique was used to monitor the process of ripening and decay in the citrus fruit that had been coated with chitosan. The dissolution of the chitosan on the mandarins and oranges produced excellent results in terms of percentage of weight loss, MRI, and visual appearance.

Analysis of Variance↗
PubMed2001

Bidimensional spectroelectrochemistry.

A new methodology is presented to offer the possibility of simultaneously obtaining two different spectroscopic signals in a single spectroelectrochemical experiment. Taking the plane of the electrode surface as a spatial reference, normal-beam and parallel-beam UV-vis absorbance signals are jointly analyzed, revealing important experimental differences between the two kinds of signals. Two different chemical systems are selected to show the possibilities of the bidimensional spectroelectrochemistry: a simple diffusive process and an adsorptive electrode reaction. Comparative results show clearly that the two kinds of spectroscopic signals, both normal and parallel to the electrode surface, have to be used together in the study of any electrode reaction scheme.

Journal Article↗
PubMed1999

The ISO/SWS Spectrum of IRC +10216: The Vibrational Bands of C2H2 and HCN.

We present the Infrared Space Observatory/Short-Wavelength Spectrometer full grating resolution spectrum of IRC +10216, which is dominated by strong absorption/emission bands of C2H2 and HCN. All C2H2 bands and the strong near-infrared stretching bands of HCN are observed in absorption, whereas the fundamental, hot, and combination bands of HCN involving the nu2 bending mode around 14 µm are observed in emission. Particularly strong is the HCN nu2=20-->nu2=11 vibrational transition at 14.3 µm. The most plausible mechanism for such emission is the radiative pumping of molecules from the ground to the nu2=20 state (7.1 µm) followed by radiative decay: nu2=20-->nu2=11. We present detailed models for HCN that verify the efficiency of the mentioned effect. The HCN abundance inferred from these models is &parl0;1.5-3&parr0;x10-5.

Journal Article↗
PubMed1998

Induced massive star formation in the trifid nebula?

The Trifid nebula is a young (10(5) years) galactic HII region where several protostellar sources have been detected with the infrared space observatory. The sources are massive (17 to 60 solar masses) and are associated with molecular gas condensations at the edges or inside the nebula. They appear to be in an early evolutionary stage and may represent the most recent generation of stars in the Trifid. These sources range from dense, apparently still inactive cores to more evolved sources, undergoing violent mass ejection episodes, including a source that powers an optical jet. These observations suggest that the protostellar sources may have evolved by induced star formation in the Trifid nebula.

Journal Article↗
PubMed1996

Ultrastructural localization of calbindin-D28k and GABA in the matrix compartment of the rat caudate-putamen nuclei.

The calcium binding protein, Calbindin-D28k, is known to be localized within spiny neurons of the matrix of the dorsal striatum, caudate-putamen nuclei. This compartment is also known to contain an abundance of GABAergic neurons and to receive extensive input from excitatory limbic and cortical afferents whose activation produces rapid influxes of calcium in neuronal targets. We used electron microscopic immunocytochemistry to examine a potential role for calbindin in GABAergic neurons in the caudate-putamen nuclei. Sections of striatal tissue from acrolein-fixed adult rat brains were dual-labeled using immunoperoxidase for the localization of rabbit anti-calbindin and immunogold-silver for the localization of rat anti-GABA antibodies. Calbindin-D28k and GABA were mainly co-localized in somata and large dendrites. The peroxidase reaction product for calbindin was diffusely distributed throughout the neuronal cytoplasm, but appeared more densely localized along asymmetric, excitatory-type, postsynaptic junctions of dendritic spines, as well as saccules of smooth endoplasmic reticulum near dendritic appositions. In contrast, the immunogold-silver labeling for GABA was largely restricted to perikarya and large dendrites. Axon terminals forming symmetric junctions were also sometimes dual-labeled for calbindin and GABA. However, the majority of the calbindin-immunoreactive terminals did not contain GABA and many formed asymmetric excitatory-type synapses with either unlabeled or calbindin-labeled dendritic spines. These results suggest that, in the striatal matrix, Calbindin-D28k contributes to the immobilization of calcium (i) in selectively activated postsynaptic spines of GABAergic and possibly non-GABAergic neurons and (ii) in terminals containing GABA as well as other excitatory and inhibitory transmitters. The extent to which calbindin is able to restrict the cytosolic increases in calcium to selective sites of utilization in these neurons may have important consequences for normal synaptic function and for neuroprotection against excitoxicity.

Animals↗
PubMed1978

Studies on cis-dichlorodiammineplatinum (II) as a radiosensitizer.

Cis-dichlorodiammineplatinum (II) (cisDDP) has been extensively studied as an antitumour agent; its binding to DNA has been proved but the radiosensitizing action has scarcely been tested. We report here that on TC.SV -40 mammalian cells cisDPP acts as a dose-modifying factor for ionizing radiation. The radiosensitizing action can be induced by two different mechanisms: reaction with non protein-SH groups and inhibition of repair processes. The cisDDP-DNA complex was studied against increasing radiation doses by analytical centrifugation and by spectrophotometrical measurements. The native complex seems to be more radiation resistant than the denatured one.

Cell Survival↗