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2.
Cir Pediatr ; 32(3): 154-157, 2019 Jul 29.
Article in Spanish | MEDLINE | ID: mdl-31486309

ABSTRACT

INTRODUCTION: Calcifying fibrous pseudotumor is a rare benign lesion with few peritoneal and mesenteric cases in pediatric population described. Its course is mainly asymptomatic, which is why diagnosis corresponds mostly to incidental findings. CLINICAL CASE: Authors present the case of a 9-year-old patient with abdominal pain, and intra-abdominal mass finding in abdominal tomography. The histopathological study realized established diagnosis of calcifying fibrous pseudotumor, which is why programmed resection of the mass was performed by laparotomy. Follow-up was performed during one year, without evidence of recurrences through ecography. COMMENTS: Authors discuss the diagnostic and therapeutic approach in this patient compared to that described in the literature.


INTRODUCCION: El pseudotumor fibroso calcificado es una lesión benigna, con pocos casos de localización peritoneal y mesentérica descritos en la población pediátrica. Su curso es principalmente asintomático, por lo cual el diagnóstico corresponde en su mayoría a hallazgos incidentales. CASO CLINICO: Se presenta el caso de una paciente de 9 años con dolor abdominal y hallazgo de masa entra-abdominal en tomografía de abdomen. El estudio histopatológico realizado estableció el diagnóstico de pseudotumor fibroso calcificado, por lo que se llevó a resección programada de la masa mediante laparotomía. El seguimiento de la paciente fue durante un año, sin evidencia de recurrencias en ecografía. COMENTARIOS: Se discute la aproximación diagnóstica y terapéutica en esta paciente comparado con lo descrito en la literatura.


Subject(s)
Laparotomy/methods , Mesentery/pathology , Peritoneal Diseases/diagnosis , Abdominal Pain/etiology , Calcinosis/pathology , Child , Female , Follow-Up Studies , Humans , Peritoneal Diseases/pathology , Peritoneal Diseases/surgery , Tomography, X-Ray Computed/methods
3.
Phys Chem Chem Phys ; 15(37): 15572-83, 2013 Oct 07.
Article in English | MEDLINE | ID: mdl-23942644

ABSTRACT

Biotic and abiotic emissions of molecular iodine and iodocarbons from the sea or the ice surface and the intertidal zone to the coastal/polar marine boundary layer lead to the formation of iodine oxides, which subsequently nucleate forming iodine oxide particles (IOPs). Although the link between coastal iodine emissions and ultrafine aerosol bursts is well established, the details of the nucleation mechanism have not yet been elucidated. In this paper, results of a theoretical study of a range of potentially relevant aggregation reactions of different iodine oxides, as well as complexation with water molecules, are reported. Thermochemical properties of these reactions are obtained from high level ab initio correlated calculations including spin-orbit corrections. The results show that the nucleation path most likely proceeds through dimerisation of I2O4. It is also shown that water can hinder gas-to-particle conversion to some extent, although complexation with key iodine oxides does not remove enough of these to stop IOP formation. A consistent picture of this process emerges from the theoretical study presented here and the findings of a new laboratory study reported in the accompanying paper (Gomez Martin et al., 2013).


Subject(s)
Iodine/chemistry , Oxides/chemistry , Aerosols/chemistry , Dimerization , Models, Molecular , Thermodynamics , Water/chemistry
4.
J Phys Chem A ; 117(39): 9564-73, 2013 Oct 03.
Article in English | MEDLINE | ID: mdl-23360125

ABSTRACT

Cyanate and bicarbonate are two ions that play active roles in many fields of physics and chemistry, including biological sciences and astrochemistry. We present here a comprehensive study of these species covering a range of phases and methodologies. We have performed theoretical calculations on the isolated ions and their hydrates with one to four water molecules, and in clusters with 15 water molecules. The predicted infrared spectra are compared with observed spectra from experiments where liquid droplets of their solutions are frozen at 14 K on a substrate, to mimic some astrophysical conditions. Crystals of cyanate and bicarbonate sodium and potassium salts are also studied experimental and theoretically. As well, the spontaneous decomposition of cyanate into bicarbonate is documented from the spectra of an aged solution. Finally, the possible astrophysical observation of bicarbonate in water-containing particles is discussed.

5.
Phys Chem Chem Phys ; 11(42): 9710-9, 2009 Nov 14.
Article in English | MEDLINE | ID: mdl-19851548

ABSTRACT

Nitric acid, hydrochloric acid and water can form stable aggregates with atmospheric implications, for instance at the surface of polar stratospheric clouds. The structure, stability and chemical properties of these ternary complexes are studied by means of high level theoretical calculations (hybrid DFT B3LYP method along with aug-cc-pVQZ basis set). From the many possible systems that these molecules could form, only 15 are found to yield stable structures, well characterized by a minimum in their potential energy surfaces. These aggregates are studied in detail. They can be collected in three families, according to the role played by each species in the different hydrogen bonding links that result and provide the basis for the stabilization of the clusters. Water and HCl can be H-donors to almost every O atom of HNO(3), which in turn can donate its H atom to the other two molecules. Two special cases are found, one in which H(2)O plays a central role, and another with a three-dimensional structure, in contrast to the basically planar frame of the other clusters. Bonding properties are investigated for the whole series using AIM methods. The elongation of the H-Cl bond as a consequence of the aggregate creation is inspected in detail, as it may provide a clue to the lability of this molecule with implications in atmospheric processes. The Gibbs free energy calculated for these clusters shows that some of them could form spontaneously in the range of temperatures of the stratosphere.

6.
J Phys Chem A ; 110(10): 3750-8, 2006 Mar 16.
Article in English | MEDLINE | ID: mdl-16526659

ABSTRACT

The ion complexes NO3-(HNO3)n, n = 1-3, have been studied by means of ab initio calculations at the B3LYP/aug-cc-pVTZ level of theory. These systems are the most abundant anionic clusters below approximately 30 km altitude in the stratosphere and also in the upper troposphere. These complexes display short strong hydrogen bonds, which should be considered to explain their abundance in the atmosphere. Equilibrium geometries, harmonic frequencies, relative energies, and thermochemical data have been calculated for these anions for the first time. The calculations indicate small differences of energy in the variation of the two nitrate groups from planarity to an almost perpendicular form for n = 1. Planar geometries are found for n = 2 and 3 to give rise to a highly symmetric C(3h) NO3-(HNO3)3. In all the cases, binding energies close to those of covalent compounds are estimated. When experimental data are available, good correlations are found with our results.


Subject(s)
Anions/chemistry , Models, Theoretical , Nitrates/chemistry , Nitric Acid/chemistry , Hydrogen Bonding , Models, Chemical , Molecular Structure , Quantum Theory , Thermodynamics
7.
J Chem Phys ; 122(21): 214307, 2005 Jun 01.
Article in English | MEDLINE | ID: mdl-15974738

ABSTRACT

Proton transfer in hydrogen-bond systems formed by 4-methylimidazole in both neutral and protonated cationic forms and by acetate anion are studied by means of MP26-311++G(d,p) ab initio calculations. These two complexes model the histidine (neutral and protonated)-aspartate diad present in the active sites of enzymes the catalytic mechanism of which involves the formation of strong hydrogen bonds. We investigate the evolution of geometries, natural bond orbital populations of bonds and electron lone pairs, topological descriptors of the electron density, and spatial distributions of the electron localization function along the process N-H...O-->N...H...O-->N...H-O, which represents the stages of the H-transfer. Except for a sudden change in the population of electron lone pairs in N and O at the middle N...H...O stage, all the properties analyzed show a smooth continuous behavior along the covalent --> hydrogen bond transit inherent to the transfer, without any discontinuity that could identify a formation or breaking of the hydrogen bond. This way, the distinction between covalent or hydrogen-bonding features is associated to subtle electron rearrangement at the intermolecular space.

8.
Aten Primaria ; 14(1): 551-4, 1994 Jun 15.
Article in Spanish | MEDLINE | ID: mdl-7918961

ABSTRACT

OBJECTIVE: To determine the type of diabetic instruction (reading materials, talks and/or courses) received by a group of diabetics in relation to a series of personal variables such as gender, age, education, type of diabetes mellitus, length of time ill and type of treatment. DESIGN: This was an observation study. Data was collected by means of a questionnaire filled in at a personal interview with the patients. SETTING: Out-patient hospital endocrinology clinics. PATIENTS AND OTHER PARTICIPANTS: 520 diabetic patients monitored in the out-patient clinics were selected at random. 35 were excluded because of their hearing, linguistic or psychological deficiencies. Only one patient refused to answer the questionnaire. MEASUREMENTS AND MAIN RESULTS: It was found that 63.07% of the patients surveyed had not done any reading or attended a course of diabetes training; 16.73% had been instructed through reading material and the remaining 20.19% had attended organised talks and/or courses about their illness. Additionally, there was statistically significant dependence between the kind of training received and patients' age (p < 0.001), educational level (p < 0.0001), the type of diabetes mellitus (p < 0.001), the length of time ill (p < 0.001) and the kind of treatment (p < 0.0001). CONCLUSIONS: In general the diabetic patients studied were found to have a deficient level of training. Therefore it is extremely important to organise talks and/or educational courses on their condition with the aim of raising their level of understanding and thus improve their control of the illness.


Subject(s)
Diabetes Mellitus, Type 1 , Diabetes Mellitus, Type 2 , Patient Education as Topic/methods , Adolescent , Adult , Aged , Aged, 80 and over , Evaluation Studies as Topic , Female , Humans , Male , Middle Aged , Patient Education as Topic/statistics & numerical data
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