XPS Study on Calcining Mixtures of Brucite with Titania.

In this work, we studied the phases in a Mg-Ti-O system using a 1:1 formulation of MgO:TiO2, mixing synthetic brucite of Mexican origin with TiO2 microparticles of high purity, with a heat treatment at 1100 °C for 1 h. Due to its valence electrons, TiO2 can contribute to the sintering process to improve density in MgO products. The raw materials and formulation by XPS and X-RD techniques were characterized. The results demonstrate the presence of different oxidation states in titania and the formation of different oxides in the Mg-Ti-O system when mixed and calcined at 1100 °C; additionally, we estimated the formation of vacancies in the crystal lattice during the transformation from hexagonal brucite to magnesia with a cubic structure centered on the faces. Its thermal behavior is indicated by the MgO-TiO2 phase diagram.

Comparación de escalas de predicción mortalidad neonatal (crib, crib ii, snap ii, snappe ii) entre recién nacidos prematuros y a término / Comparison of neonatal mortality prediction scales (crib, crib ii, snap ii, snappe ii) between preterm and full term infants

Objetivo: Este artículo compara 4 escalas de predicción de mortalidad y gravedad de la enfermedad (CRIB, CRIB II, SNAPPE, SNAPPE II) en recién nacidos prematuros y a términos, ingresados a las unidades de cuidaos intensivos neonatales (UCIN) para determinar cuál de ellas, tiene mayor discriminación pronostica. Métodos: es un estudio transversal, observacional, multicéntrico para comparar varias escalas de predicción de mortalidad y de la enfermedad. Se recolectaron datos de 227 recién nacidos ingresados a las UCIN de 4 hospitales desde julio a diciembre del 2018. Evaluamos las escalas CRIB, CRIB II, SNAPII y SNAP-PE score en recién nacidos prematuros y a término. El área bajo la curva (ROC) fue usada para evaluar y comparar los resultados de predicción de mortalidad y morbilidad. Resultados: Un total of 227 recién nacidos fueron evaluados (media CRIB: 7,81±3,52 media CRIB-II: 11,96±3,91; media SNAP-II: 34,99±16,83, SNAPPE II: 14,61±13,30). Se evidenció una mayor discriminación para las escalas CRIB II y CRIB en relación con SNAP-II y SNAPP II (AUC 0.94 y 0.93 vs 0.86 y 0,77). Además de cada puntuación, varias variables influyeron significativamente en la supervivencia en los modelos de regresión logística. Conclusiones: Todas las escalas de predicción de mortalidad y de gravedad de la enfermedad sirven para utilizarse en las UCIN estudiadas, siendo la escala CRIB II la de mejor rendimiento para aplicarse en nuestro medio.

Objective: This article compares 4 scales of prediction of mortality and disease severity (CRIB, CRIB II, SNAPPE, SNAPPE II) in preterm and term new borns admitted to neonatal intensive care units (NICU) to determine which of them has greater forecast discrimination. Methods: it is a cross-sectional, observational, multicenter study that compares several mortality and disease prediction scales. Data were collected from 227 newborns admitted to the NICU of 4 hospitals from July to December 2018. We evaluated the CRIB, CRIB II, SNAPII and SNAP-PE score scales in preterm and full term infants. The area under the curve (ROC) was used to evaluate and compare the prediction results of mortality and morbidity. Results: A total of 227 newborns were evaluated (mean CRIB: 7.81 ± 3.52 mean CRIB-II: 11.96 ± 3.91, average SNAP-II: 34.99 ± 16.83, SNAPPE II: 14.61 ± 13.30). There was evidence of greater discrimination for the CRIB II and CRIB scales in relation to SNAP-II and SNAPP II (AUC 0.94 and 0.93 vs 0.86 and 0.77). In addition to each score, several variables significantly influenced survival in the logistic regression models. Conclusions: All the prediction scales of mortality and severity of the disease serve to be used in the studied NICUs, being the CRIB II scale the best performance to apply in our environment.

Reporte de caso clínico neonato con hiperplasia suprarrenal congénita por déficit de 21 hidroxilasa en su forma clásica perdedora de sal / Neonatal clinical case report with congenital adrenal hyperplasia due to 21 hydroxylase deficiency in its classic salt-losing form

La hiperplasia suprarrenal congénita (HSC), es un desorden endócrino genético debido a alteraciones en la esteroidogénesis adrenal por déficit de una de las enzimas participantes en este ciclo, caracterizado por diferentes grados de alteración en la síntesis de glucocorticoides y mineralocorticoides más una sobreestimulación de la vía androgénica provocando durante el desarrollo embrionario la virilización de los genitales externos. En el 90 a 95 % de los casos la enzima más afectada es la 21 hidroxilasa y de éstas el 75% tiene déficit de aldosterona con pérdida de sal que da lugar a crisis adrenal con riesgo de vida. Se clasifica en su forma clásica y no clásica. El diagnóstico prenatal es fundamental para delinear estrategias de tratamiento perinatal. El déficit de 21-hidroxilasa es el primer diagnóstico que se plantea ante un recién nacido con genitales ambiguos y se debería iniciar terapia de reemplazo hormonal. Presentamos un caso clínico de un neonato con hiperplasia suprarrenal congénita por déficit de 21-hidroxilasa en su forma clásica perdedor de sal.

Congenital adrenal hyperplasia (CAH) is an endocrine genetic disorder due to alterations in adrenal steroidogenesis due to a deficiency of one of the enzymes participating in this cycle, characterized by different degrees of alteration in the synthesis of glucocorticoids and mineralocorticoids plus an overstimulation of the androgenic pathway causing during the embryonic development the virilization of the external genitalia. In 90 to 95% of the cases the most affected enzyme is 21 hydroxylase and of these 75% have aldosterone deficit with salt loss that leads to adrenal crisis with life risk. It is classified in classical and non-classical form. Prenatal diagnosis is essential to delineate perinatal treatment strategies. Deficiency of 21-hydroxylase is the first diagnosis that is presented to a newborn with ambiguous genitalia and should initiate hormone replacement therapy. We present a clinical case of a neonate with congenital adrenal hyperplasia due to a deficiency of 21-hydroxylase in its classical salt-losing form.

Molecular characterization of a new begomovirus that infects Euphorbia heterophylla and Solanum lycopersicum in Venezuela.

We report the complete nucleotide sequence of a begomovirus isolate infecting Euphorbia heterophylla and tomato (Solanum lycopersicum) in central Venezuela. Based on the current taxonomic criteria for the genus Begomovirus, the isolate was shown to represent a novel species, tentatively named Euphorbia mosaic Venezuela virus (EuMVV). Its DNA-A is most closely related to those of Euphorbia-infecting begomoviruses from the Caribbean and Central America. The DNA B component forms a phylogenetic cluster with Euphorbia and Sida-infecting begomoviruses from the squash leaf curl virus (SLCV) cluster. EuMVV is transmissible to S. lycopersicum and Capsicum annuum by biolistics of infectious cloned DNA-A and DNA-B components and induces characteristic leaf downward curling and yellowing in S. lycopersicum and and yellowing and leaf distortion in Capsicum annuum.

Tomato chlorotic leaf distortion virus, a new bipartite begomovirus infecting Solanum lycopersicum and Capsicum chinense in Venezuela.

Virus isolate T217L was obtained from a diseased tomato (Solanum lycopersicum) plant showing leaf deformation and chlorotic mottle symptoms near Maracaibo in the state of Zulia, Venezuela. Full-length DNA-A and DNA-B molecules of T217L were cloned and sequenced. The genome organization of T217L was identical to the bipartite genomes of other begomoviruses described from the Americas. Characteristic disease symptoms were reproduced in S. lycopersicum and Capsicum annum plants inoculated using the cloned viral DNA-A and DNA-B components, confirming disease aetiology. A sequence analysis of DNA-A showed that the T217L isolate has the highest sequence identity (84%) with sida yellow mosaic Yucatan virus (SiYMYuV), sida golden mosaic Honduras virus (SiGMHV) and bean dwarf mosaic virus (BDMV) isolates. This is less than the 89% identity in the DNA-A component that has been defined as the threshold value for the demarcation of species in the genus Begomovirus. The molecular data show that isolate T217L belongs to a novel tentative begomovirus species, for which the name tomato chlorotic leaf distortion virus is proposed. TCLDV was also detected in symptomatic C. chinense plants growing near the T217L-infected plant.

Caracterización de un tobamovirus aislado de plantas de canavalia (Canavalia ensiformis L.) en una parcela experimental del Edo. Aragua Venezuela / Characterization of a tobamovirus isolated from canavalia (Canavalia ensiformis L) in an experimental parcel at Aragua-State Venezuela

Se identificó un Tobamovirus infectando al cultivo de canavalia en una parcela experimental del estado Aragua, Venezuela. El rango de hospedantes y las pruebas serológicas basadas en la técnica de Western blot, permitieron determinar que el virus en estudio es un aislamiento del virus del mosaico del tabaco (TMV). Este resultado fue confirmado por el análisis de secuencia del gen de la proteína de la cápside, amplificado mediante RT-PCR, el cual reveló una identidad cercana al 98 por ciento entre el aislamiento descrito en esta investigación y cepas de TMV reportadas en Korea y Japón.