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1.
Eat Weight Disord ; 27(8): 3379-3387, 2022 Dec.
Article En | MEDLINE | ID: mdl-36272036

PURPOSE: The aim of this study was to develop an instrument to identify disordered eating behaviors (DEB) in college men (hereafter, DEBM-Q). METHODS: A two-stage project consisting of a diagnostic scale construction (n1 = 9 for interviews, n2 = 9 for cognitive laboratory) and a validation study with a cross-sectional sample (N = 570) was carried out. Both semi-structured interviews and a cognitive laboratory with nine participants were conducted to obtain DEBM-Q items. DEBM-Q was applied to 570 freshmen male in Mexico City. Psychometric characteristics and internal consistency (Cronbach's alpha) were analyzed. An item-total correlation value greater than 0.30 was determined, and factor loads greater than 0.40 were considered valid. Exploratory factor analysis (EFA, n1 = 297) and confirmatory factor analysis (CFA, n2 = 273) were performed. RESULTS: Two fixed factors explaining 55.08% of the total variance were extracted. Factor 1, "Drive for Thinness" (8 items), explained 30.84% of the variance, whereas factor 2, "Drive for Muscularity" (8 items), explained 24.23% of the variance. Cronbach's alpha for the whole questionnaire was 0.84. DEBM-Q was correlated with the Dutch Food Restriction Scale (RS) (r = 0.52, p < 0.001), Eating Disorder Examination-Questionnaire (EDE-Q) (r = 0.46, p < 0.001), Emotional Eating Scale (EES) (r = 0.18, p < 0.001), and Negative Affect Subscale (PANAS-X) (r = 0.11, p < 0.005). CONCLUSION: DEBM-Q is a valid and practical short screening tool (16 items) allowing early identification of disordered eating in young men, thereby facilitating clinical management. LEVEL OF EVIDENCE: Level V: Opinions of authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.


Feeding and Eating Disorders , Humans , Male , Cross-Sectional Studies , Feeding and Eating Disorders/diagnosis , Drive , Surveys and Questionnaires , Psychometrics , Reproducibility of Results
2.
Molecules ; 27(10)2022 May 19.
Article En | MEDLINE | ID: mdl-35630720

DRIFT, HPLC-MS, and SPME-GC/MS analyses were used to unveil the structure and the main functional compounds of red (blood) orange (Citrus sinensis) and bitter orange (Citrus aurantium). The IntegroPectin samples show evidence that these new citrus pectins are comprised of pectin rich in RG-I hairy regions functionalized with citrus biophenols, chiefly flavonoids and volatile molecules, mostly terpenes. Remarkably, IntegroPectin from the peel of fresh bitter oranges is the first high methoxyl citrus pectin extracted via hydrodynamic cavitation, whereas the red orange IntegroPectin is a low methoxyl pectin. C. aurantium IntegroPectin has a uniquely high concentration of adsorbed flavonoids, especially the flavanone glycosides hesperidin, naringin, and eriocitrin.


Citrus sinensis , Citrus , Hesperidin , Citrus/chemistry , Citrus sinensis/chemistry , Flavonoids/analysis , Pectins
3.
Rev. neuro-psiquiatr. (Impr.) ; 85(1): 12-18, ene.-mar. 2022. tab
Article Es | LILACS-Express | LILACS | ID: biblio-1377160

RESUMEN Objetivo : Explorar las percepciones de crianza parental en adolescentes diagnosticados con algún trastorno de la conducta alimentaria, e identificar posibles diferencias con alteraciones de la conducta alimentaria y conductas autolesivas. Material y métodos : Un total de 45 adolescentes con algún tipo de trastorno de la conducta alimentaria (TCA) (11 diagnosticados con anorexia nervosa, 23 con bulimia nervosa y 11 con trastorno "por atracón"), pacientes en áreas de consulta externa y hospitalización del Hospital Psiquiátrico Infantil Juan N. Navarro fueron sistemáticamente estudiados. Resultados : Se encontró que cuánto mayores las percepciones de favoritismo (r = 0,41, valor p = 0,005) o rechazo (r = 0,36, valor p = 0,016) del padre, mayores fueron también los puntajes en la Escala de Actitudes Alimentarias. Se encontraron asimismo diferencias en la dimensión de calidez de la madre, entre los adolescentes que presentaron autolesiones (media = 39,6, d.e = 11,3) comparados con aquéllos que no las presentaron (media = 47,4, d.e = 8.8) (t = -2,6, valor p = 0,015). Conclusiones : Los adolescentes con diagnóstico de TCA presentaron diferencias en la percepción de crianza parental, factor que puede influenciar decisivamente la manifestación de otras conductas psicopatológicas.


SUMMARY Objective : To explore the perceived parental rearing behavior in adolescents diagnosed with an eating disorder, and to identify eventual differences with altered eating and self-injurious behaviors. Material and methods : A total of 45 adolescents diagnosed with some eating disorder (11 diagnosed with anorexia nervosa, 23 with bulimia nervosa and 11 with binge eating disorder), recruited from the outpatient and hospitalization areas of the Juan N Navarro Children's Psychiatric Hospital, were included. Results : It was found that the greater the memories of favoritism (r = 0.41, p-value = 0.005) or rejection (r = 0.36, p-value = 0.016) by the father, the higher the scores ​​on the Eating Attitude Scale. Differences were also found in the mother's warmth dimension, between the adolescents who presented self-injuries (mean = 39.6, de = 11.3) and those who did not present them (mean = 47.4, de = 8.8) (t = -2.6, value p = 0.015). Conclusions : Adolescents with a diagnosis of eating disorders presented differences in their perception of parental rearing, a factor that may decisively influence the manifestation of other psychopathological behaviors.

4.
Nutrients ; 14(2)2022 Jan 17.
Article En | MEDLINE | ID: mdl-35057575

Alterations in eating behavior characterized eating disorders (ED). The genetic factors shared between ED diagnoses have been underexplored. The present study performed a genome-wide association study in individuals with disordered eating behaviors in the Mexican population, blood methylation quantitative trait loci (blood-meQTL), summary data-based Mendelian randomization (SMR) analysis, and in silico function prediction by different algorithms. The analysis included a total of 1803 individuals. We performed a genome-wide association study and blood-meQTL analysis by logistic and linear regression. In addition, we analyzed in silico functional variant prediction, phenome-wide, and multi-tissue expression quantitative trait loci. The genome-wide association study identified 44 single-nucleotide polymorphisms (SNP) associated at a nominal value and seven blood-meQTL at a genome-wide threshold. The SNPs show enrichment in genome-wide associations of the metabolic and immunologic domains. In the in silico analysis, the SNP rs10419198 (p-value = 4.85 × 10-5) located on an enhancer mark could change the expression of PRR12 in blood, adipocytes, and brain areas that regulate food intake. Additionally, we found an association of DNA methylation levels of SETBP1 (p-value = 6.76 × 10-4) and SEMG1 (p-value = 5.73 × 10-4) by SMR analysis. The present study supports the previous associations of genetic variation in the metabolic domain with ED.


Feeding and Eating Disorders/genetics , Genome-Wide Association Study , Adolescent , Adult , Computer Simulation , DNA/blood , DNA Methylation/genetics , Feeding Behavior , Female , Genetic Predisposition to Disease/genetics , Humans , Male , Mendelian Randomization Analysis , Mexico , Polymorphism, Single Nucleotide/genetics , Quantitative Trait Loci/genetics , Young Adult
5.
Nutrients ; 13(9)2021 Sep 15.
Article En | MEDLINE | ID: mdl-34579086

Eating disorders are psychiatric disorders characterized by disturbed eating behaviors. They have a complex etiology in which genetic and environmental factors interact. Analyzing gene-environment interactions could help us to identify the mechanisms involved in the etiology of such conditions. For example, comethylation module analysis could detect the small effects of epigenetic interactions, reflecting the influence of environmental factors. We used MethylationEPIC and Psycharray microarrays to determine DNA methylation levels and genotype from 63 teenagers with eating disorders. We identified 11 comethylation modules in WGCNA (Weighted Gene Correlation Network Analysis) and correlated them with single nucleotide polymorphisms (SNP) and clinical features in our subjects. Two comethylation modules correlated with clinical features (BMI and height) in our sample and with SNPs associated with these phenotypes. One of these comethylation modules (yellow) correlated with BMI and rs10494217 polymorphism (associated with waist-hip ratio). Another module (black) was correlated with height, rs9349206, rs11761528, and rs17726787 SNPs; these polymorphisms were associated with height in previous GWAS. Our data suggest that genetic variations could alter epigenetics, and that these perturbations could be reflected as variations in clinical features.


Epigenesis, Genetic , Feeding and Eating Disorders/epidemiology , Feeding and Eating Disorders/genetics , Genetic Predisposition to Disease , Polymorphism, Single Nucleotide , Adolescent , DNA Methylation , Gene Expression Regulation , Gene Regulatory Networks , Genotype , Humans , Mexico/epidemiology
6.
Nutrients ; 13(5)2021 Apr 22.
Article En | MEDLINE | ID: mdl-33922358

Binge-eating disorder, recently accepted as a diagnostic category, is differentiated from bulimia nervosa in that the former shows the presence of binge-eating episodes and the absence of compensatory behavior. Epigenetics is a conjunct of mechanisms (like DNA methylation) that regulate gene expression, which are dependent on environmental changes. Analysis of DNA methylation in eating disorders shows that it is reduced. The present study aimed to analyze the genome-wide DNA methylation differences between individuals diagnosed with BED and BN. A total of 46 individuals were analyzed using the Infinium Methylation EPIC array. We found 11 differentially methylated sites between BED- and BN-diagnosed individuals, with genome-wide significance. Most of the associations were found in genes related to metabolic processes (ST3GAL4, PRKAG2, and FRK), which are hypomethylated genes in BED. Cg04781532, located in the body of the PRKAG2 gene (protein kinase AMP-activated non-catalytic subunit gamma 2), was hypomethylated in individuals with BED. Agonists of PRKAG2, which is the subunit of AMPK (AMP-activated protein kinase), are proposed to treat obesity, BED, and BN. The present study contributes important insights into the effect that BED could have on PRKAG2 activation.


Binge-Eating Disorder/diagnosis , Binge-Eating Disorder/genetics , DNA Methylation/genetics , Metabolism/genetics , Adolescent , Anorexia Nervosa/diagnosis , Anorexia Nervosa/genetics , Female , Humans , Male , Pilot Projects
7.
Article En | MEDLINE | ID: mdl-33917708

The prevalence of comorbid psychiatric disorders among patients with eating disorders (ED) is higher than the general population. Individuals diagnosed with eating disorders have changes in their body mass index which could promote severe metabolic disruptions. This study aimed (1) to report the prevalence of comorbid psychiatric disorders among a Mexican adolescent sample diagnosed with eating disorders, (2) to compare our results with the prevalence of psychiatric disorders reported from a national survey of mental health of adolescents, (3) to compare the presence of psychiatric comorbidities between ED diagnoses, and (4) to explore the relationship of these comorbidities with the body mass index. In the study, we included 187 Mexican adolescents diagnosed with eating disorders. The psychiatric comorbidities were evaluated using the Mini International Neuropsychiatric Interview for children/adolescents, and a revised questionnaire on eating and weight patterns. We found that 89% of the Mexican adolescents diagnosed with ED had another psychiatric comorbidity. Major depressive disorder (52.40%) and suicide risk (40%) were the most prevalent comorbidities. Attention and deficit hyperactivity disorder (ADHD) prevalence was different between ED diagnosis, and adolescents with binge-eating disorder and ADHD had the higher body mass index. Our results showed that in this sample of Mexican adolescents, the presence of comorbidities could impact body mass index. This emphasizes the importance that clinicians take into consideration the presence of psychiatric comorbidities to achieve an integrative treatment for adolescents diagnosed with ED.


Attention Deficit Disorder with Hyperactivity , Depressive Disorder, Major , Feeding and Eating Disorders , Mental Disorders , Adolescent , Attention Deficit Disorder with Hyperactivity/epidemiology , Body Mass Index , Child , Comorbidity , Feeding and Eating Disorders/epidemiology , Humans , Mental Disorders/epidemiology , Prevalence
8.
Psicol. conduct ; 29(1): 51-72, 2021. tab, graf
Article Es | IBECS | ID: ibc-202206

La etiología de los trastornos del comportamiento alimentario (TCA) es compleja y múltiples modelos han intentado conceptualizarla. El objetivo de este estudio fue determinar si los comportamientos interiorizados y exteriorizados son factores de riesgo generales de psicopatología o específicos de los TCA y que componentes sintomatológicos del TCA están relacionados con estos comportamientos. Para ello, se utilizó un diseño transversal caso-control para comparar los TCA de inicio (n = 50) con tres grupos de control: un grupo con patología psiquiátrica (trastornos depresivos [TD], n = 40), otro con patología psicosomática (asma, n = 40) y un grupo control sin patología (n = 50). La muestra está compuesta por 180 mujeres adolescentes de 12-18 años y sus familias emparejadas por edad y estatus socioeconómico. Los resultados obtenidos indican que la interiorización es un factor de riesgo general para la psicopatología de TCA y TD, y que en los TCA está asociada específicamente con la obsesión por la delgadez, la ineficacia, la conciencia interoceptiva, la depresión, la ansiedad rasgo y la sintomatología obsesivo-compulsiva. Así, se entiende la elevada comorbilidad de los TCA con otros comportamientos interiorizados


The etiology of eating disorders (ED) is complex, and multiple models have attempted to conceptualize it. The objective of this study was to determine whether internalizing and externalizing behaviors are general proximal risk factors for psychopathology or specific for ED, and which symptomatic components of ED are related to these behaviors. Hence, a cross-case-control design was used to compare eating disorders at onset (n = 50) with three control groups: a group with psychiatric pathologies (depressive disorders [DD], n = 40), a group with psychosomatic pathology (asthma, n = 40), and a control group without pathologies (n = 50). The entire sample is made up of 180 adolescent women aged 12-18 years and their families matched by age and socioeconomic status. The results obtained indicate that internalization is a general risk factor for the psychopathology of ED and mood disorders, and that in ED it is specifically associated with a drive for thinness, ineffectiveness, interoceptive awareness, depression, trait-anxiety and obsessive-compulsive symptomatology. Thus, the high comorbidity of ED is associated mainly with other internalizing behaviors


Humans , Female , Child , Adolescent , Feeding and Eating Disorders/psychology , Adolescent Behavior/psychology , Depressive Disorder/psychology , Asthma/psychology , Cross-Sectional Studies , Case-Control Studies , Feeding and Eating Disorders/etiology , Risk Factors , Surveys and Questionnaires , Behavior Rating Scale , Psychiatric Status Rating Scales , Socioeconomic Factors , Psychophysiologic Disorders/psychology
9.
Langmuir ; 33(42): 11429-11435, 2017 10 24.
Article En | MEDLINE | ID: mdl-28922605

In this work, we demonstrate that n-alkanes coil when mixed with perfluoroalkanes, changing their conformational equilibria to more globular states, with a higher number of gauche conformations. The new coiling effect is here observed in fluids governed exclusively by dispersion interactions, contrary to other examples in which hydrogen bonding and polarity play important roles. FTIR spectra of liquid mixtures of n-hexane and perfluorohexane unambiguously reveal that the population of n-hexane molecules in all-trans conformation reduces from 32% in the pure n-alkane to practically zero. The spectra of perfluorohexane remain unchanged, suggesting nanosegregation of the hydrogenated and fluorinated chains. Molecular dynamics simulations support this analysis. The new solvophobic effect is prone to have a major impact on the structure, organization, and therefore thermodynamic properties and phase equilibria of fluids involving mixed hydrogenated and fluorinated chains.

10.
J Phys Chem B ; 120(38): 10091-10105, 2016 Sep 29.
Article En | MEDLINE | ID: mdl-27574862

This article reports a combined thermodynamic, spectroscopic, and computational study on the interactions and structure of binary mixtures of hydrogenated and fluorinated substances that simultaneously interact through strong hydrogen bonding. Four binary mixtures of hydrogenated and fluorinated alcohols have been studied, namely, (ethanol + 2,2,2-trifluoroethanol (TFE)), (ethanol + 2,2,3,3,4,4,4-heptafluoro-1-butanol), (1-butanol (BuOH) + TFE), and (BuOH + 2,2,3,3,4,4,4-heptafluoro-1-butanol). Excess molar volumes and vibrational spectra of all four binary mixtures have been measured as a function of composition at 298 K, and molecular dynamics simulations have been performed. The systems display a complex behavior when compared with mixtures of hydrogenated alcohols and mixtures of alkanes and perfluoroalkanes. The combined analysis of the results from different approaches indicates that this results from a balance between preferential hydrogen bonding between the hydrogenated and fluorinated alcohols and the unfavorable dispersion forces between the hydrogenated and fluorinated chains. As the chain length increases, the contribution of dispersion increases and overcomes the contribution of H-bonds. In terms of the liquid structure, the simulations suggest the possibility of segregation between the hydrogenated and fluorinated segments, a hypothesis corroborated by the spectroscopic results. Furthermore, a quantitative analysis of the infrared spectra reveals that the presence of fluorinated groups induces conformational changes in the hydrogenated chains from the usually preferred all-trans to more globular arrangements involving gauche conformations. Conformational rearrangements at the CCOH dihedral angle upon mixing are also disclosed by the spectra.

12.
Eur Eat Disord Rev ; 24(1): 62-8, 2016 Jan.
Article En | MEDLINE | ID: mdl-26118356

Literature suggests that families may accommodate patients' symptoms in attempts to alleviate family conflict and stress. These accommodating and enabling behaviours may have a negative impact on carers and those they care for. There are no self-report questionnaires validated in Spanish to measure accommodation among relatives of patients with an eating disorder. The aim of this study was to examine the psychometric properties of the Spanish version of the Accommodation and Enabling Scale for Eating Disorders (AESED-S) among relatives of eating disorder patients. A cross-sectional study of 90 relatives was carried out to explore the factor structure, reliability and validity of the AESED-S. The internal consistency of the Spanish version of the AESED subscales was good, ranging from .89 to .81. The correlation of the five subscales with conceptually related measures (negative caregiving experience and distress) supports the convergent validity of this instrument in this sample. Results indicated that the Spanish version of the AESED provides a reliable and valid tool for assessing family accommodation in the context of having a relative with an eating disorder.


Caregivers/psychology , Feeding and Eating Disorders/psychology , Language , Surveys and Questionnaires , Adolescent , Adult , Caregivers/statistics & numerical data , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Pilot Projects , Psychometrics , Reproducibility of Results , Young Adult
13.
J Phys Chem B ; 120(38): 10091-10105, 2016 Sep 29.
Article En | MEDLINE | ID: mdl-30801196

This article reports a combined thermodynamic, spectroscopic, and computational study on the interactions and structure of binary mixtures of hydrogenated and fluorinated substances that simultaneously interact through strong hydrogen bonding. Four binary mixtures of hydrogenated and fluorinated alcohols have been studied, namely, (ethanol + 2,2,2-trifluoroethanol (TFE)), (ethanol + 2,2,3,3,4,4,4-heptafluoro-1-butanol), (1-butanol (BuOH) + TFE), and (BuOH + 2,2,3,3,4,4,4-heptafluoro-1-butanol). Excess molar volumes and vibrational spectra of all four binary mixtures have been measured as a function of composition at 298 K, and molecular dynamics simulations have been performed. The systems display a complex behavior when compared with mixtures of hydrogenated alcohols and mixtures of alkanes and perfluoroalkanes. The combined analysis of the results from different approaches indicates that this results from a balance between preferential hydrogen bonding between the hydrogenated and fluorinated alcohols and the unfavorable dispersion forces between the hydrogenated and fluorinated chains. As the chain length increases, the contribution of dispersion increases and overcomes the contribution of H-bonds. In terms of the liquid structure, the simulations suggest the possibility of segregation between the hydrogenated and fluorinated segments, a hypothesis corroborated by the spectroscopic results. Furthermore, a quantitative analysis of the infrared spectra reveals that the presence of fluorinated groups induces conformational changes in the hydrogenated chains from the usually preferred all-trans to more globular arrangements involving gauche conformations. Conformational rearrangements at the CCOH dihedral angle upon mixing are also disclosed by the spectra.

14.
J Phys Chem B ; 115(26): 8481-92, 2011 Jul 07.
Article En | MEDLINE | ID: mdl-21604799

Densities and molar excess volumes of the solutions of pyridine or nicotine in liquid polyethylene glycol, PEG200 and PEG400, have been determined at several temperatures. The experimental molar excess volumes are negative, thus indicating strong attractive interactions between the components, as could be expected considering their highly polar nature and good hydrogen bond abilities. For the pyridine systems, this negativity is slightly increased as the temperature rises, while the opposite tendency is observed for the nicotine mixtures. When pyridine and nicotine solutions are compared, the former-particularly those with PEG400-exhibit substantially more negative molar excess volumes than the latter. The effect of the polymer chain length on the results for the nicotine solutions is almost negligible. However, this is not the case when pyridine is one of the components: a longer chain induced considerably higher compression on mixing. The Fourier-transform infrared analysis allowed interpretation of the negative experimental molar excess volumes in terms of specific inter- and intramolecular interactions.


Nicotine/chemistry , Polyethylene Glycols/chemistry , Pyridines/chemistry , Solutions/chemistry , Humans , Lipid Bilayers/chemistry , Molecular Structure , Molecular Weight , Spectroscopy, Fourier Transform Infrared/methods
15.
Rev. Soc. Esp. Enferm. Nefrol ; 12(4): 294-299, oct.-dic. 2009. tab, ilus
Article Es | IBECS | ID: ibc-75206

El objetivo de este trabajo fue identificar los problemas de enfermería en la atención a pacientes añosos (a partir de 65 años), receptores de injerto renal durante su ingreso hospitalario para el trasplante. Para ello se analizaron retrospectivamente las historias clínicas de los años 2005 y2006, codificándose los problemas de enfermería mediante la Taxonomía NANDA. Se utilizó la estadística descriptiva para mostrar la frecuencia y duración de los problemas, así como la presencia de complicaciones médicas. También se contabilizaron el número de transfusiones sanguíneas, número de hemodiálisis post-trasplante y el número de pacientes que precisaron de suero de irrigación continua vesical para tratar los problemas de coágulos intravesicales. Los problemas de enfermería más frecuentes son: riesgo de infección, riesgo de lesión perioperatoria, exceso de volumen de líquidos, deterioro de la integridad cutánea, deterioro de la movilidad física, déficit de autocuidados, conocimientos deficientes y deterioro del patrón del sueño. Los problemas que, al alta, quedaron sin resolver de forma más frecuente fueron deterioro de la eliminación urinaria, conocimientos deficientes, riesgo de glucemia inestable y deterioro del patrón del sueño. Las complicaciones médicas más frecuentes fueron la necrosis tubular aguda y la fístula urinaria. El 23% de los pacientes necesitaron transfusiones de sangre post-cirugía, el 45%necesitó de hemodiálisis en los días posteriores al trasplante y el 38% necesitó de irrigación continua vesical (AU)


The aim of this work was to identify the nursing problems in the care of elderly patients (aged 65and over) who receive a kidney graft during their time in hospital for transplant. To do so, the clinical histories of the years 2005 and 2006 were analysed retrospectively, and the nursing problems were coded using NANDA taxonomy. Descriptive statistics were used to show the frequency and duration of the problems, and the presence of medical complications. The number of blood transfusions, number of cases of post-transplant haemodialysis and the number of patients who required continuous vesicular irrigation to treat intravesicular clotting problems were also recorded. The most frequent nursing problems are: risk of infection, risk of perioperatory injury, excess of liquids, deterioration of skin integrity, deterioration of physical mobility, insufficient self-care, deficient knowledge, and deterioration of sleep pattern. The problems which were most frequently unresolved upon discharge of the patient from hospital were deterioration of urinary elimination, deficient knowledge, risk of unstable glucaemia and deterioration of sleep pattern. The most frequent medical complications were acute tubular necrosis and urinary fistula. Post-surgery blood transfusion was needed by23% of the patients, 45% needed haemodialysis in the days after the transplant and 38% needed continuous vesicular irrigation (AU)


Humans , Male , Female , Aged , Aged, 80 and over , Risk Factors , Kidney Transplantation/instrumentation , Kidney Transplantation/nursing , Surgical Wound Dehiscence/complications , Surgical Wound Dehiscence/diagnosis , Classification/methods , Retrospective Studies
16.
Chemphyschem ; 6(7): 1299-306, 2005 Jul 11.
Article En | MEDLINE | ID: mdl-15968697

The influence of oxygen precoverage on the bonding geometry of methoxide on Ru(001) was studied using the isotopically labeled molecule CHD2OH by reflection-absorption infrared spectroscopy (RAIRS). This molecule is an excellent model because the vibrational spectra of CHD2O- may be unambiguously correlated with the adsorption configuration. For Ru(001)--O layers with an effective oxygen coverage (theta0) between 0.25 and 0.6 ML (ML=monolayer), the influence of the oxygen precoverage was shown to vary with the initial methanol exposure. For an extremely low dose of [D2]methanol (0.01 L; L=Langmuir, 1 L=10(-6) torr s), at 90 K, no oxygen-coverage effects were detected on the geometry of [D2]methoxide: it adsorbs in an upright orientation (pseudo-C(3v) local symmetry), just as on clean Ru(001). An increase in the methanol exposure to 0.1 L, at the same temperature, results in the formation of a disordered layer of tilted methoxide: for theta(O)=0.25 ML, C(s)/C1 and intrinsic C1 configurations are present on the surface, whereas for theta(O)> or =0.5 ML, only the former species were identified. The thermal activation of these tilted layers to 105 K results in a lower coverage of upright methoxide for any oxygen precoverage, coadsorbed with decomposition products, as confirmed by the detection of adsorbed formaldehyde and, on the denser oxygen layer (theta(O)=0.6 ML), formate. The influence of the oxygen precoverage becomes determinant when annealing a [D2]methanol multilayer to 105 K: for theta(O)=0.25 ML, the RAIR spectrum correlates with a disordered layer of tilted methoxide and formaldehyde, whereas for theta(O)=0.6 ML upright methoxide, formate, and carbon monoxide were identified. On clean Ru(001), for methanol exposures > or =0.1 L, the C(3v) methoxide configuration was never attained upon thermal activation.


Deuterium/chemistry , Methanol/chemistry , Oxygen/chemistry , Rhodium/chemistry , Adsorption , Methanol/analogs & derivatives , Molecular Conformation , Sensitivity and Specificity , Spectroscopy, Fourier Transform Infrared/methods , Surface Properties
17.
In. Jornadas de Historia de la Medicina Hispanoamericana, 3. III Jornadas de Historia de la Medicina Hispanoamericana. Puerto Real, INGRASA, 1992. p.193-206. (Anales de la Real Academia de Medicina y Cirugi&#769;a de Ca&#769;diz, 28, 1).
Monography Es | HISA | ID: his-35121

Biografic summary of Dr. Ulecia, a look at his peditaric work in relation to his social ideas and his preventive task with the creation of infant dispensary ("Gotas de Leche". (AU))


History, 19th Century , History, 20th Century , Pediatrics , Physicians , Professional Practice Location , Dispensatory , Cuba
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