Low-oxidation-state Ru sites stabilized in carbon-doped RuO2 with low-temperature CO2 activation to yield methane.

The generation of methane fuel using surplus renewable energy with CO2 as the carbon source enables both the decarbonization and substitution of fossil fuel feedstocks. However, high temperatures are usually required for the efficient activation of CO2. Here we present a solid catalyst synthesized using a mild, green hydrothermal synthesis that involves interstitial carbon doped into ruthenium oxide, which enables the stabilization of Ru cations in a low oxidation state and a ruthenium oxycarbonate phase to form. The catalyst shows an activity and selectivity for the conversion of CO2 into methane at lower temperatures than those of conventional catalysts, with an excellent long-term stability. Furthermore, this catalyst is able to operate under intermittent power supply conditions, which couples very well with electricity production systems based on renewable energies. The structure of the catalyst and the nature of the ruthenium species were acutely characterized by combining advanced imaging and spectroscopic tools at the macro and atomic scales, which highlighted the low-oxidation-state Ru sites (Run+, 0 < n < 4) as responsible for the high catalytic activity. This catalyst suggests alternative perspectives for materials design using interstitial dopants.

Stabilization of the Active Ruthenium Oxycarbonate Phase for Low-Temperature CO2 Methanation.

Interstitial carbon-doped RuO2 catalyst with the newly reported ruthenium oxycarbonate phase is a key component for low-temperature CO2 methanation. However, a crucial factor is the stability of interstitial carbon atoms, which can cause catalyst deactivation when removed during the reaction. In this work, the stabilization mechanism of the ruthenium oxycarbonate active phase under reaction conditions is studied by combining advanced operando spectroscopic tools with catalytic studies. Three sequential processes: carbon diffusion, metal oxide reduction, and decomposition of the oxycarbonate phase and their influence by the reaction conditions, are discussed. We present how the reaction variables and catalyst composition can promote carbon diffusion, stabilizing the oxycarbonate catalytically active phase under steady-state reaction conditions and maintaining catalyst activity and stability over long operation times. In addition, insights into the reaction mechanism and a detailed analysis of the catalyst composition that identifies an adequate balance between the two phases, i.e., ruthenium oxycarbonate and ruthenium metal, are provided to ensure an optimum catalytic behavior.

Information and communication technologies and quality of life in home confinement: Development and validation of the TICO scale.

The mandatory home confinement of the Spanish population, implemented in response to the COVID-19 pandemic, presents a unique opportunity to study the use and influence of Information and Communication Technologies (ICT) in people's perception of quality of life during this exceptional situation. This article adapts and validates a psychometric scale designed to identify and measure the main dimensions of the Quality of Life construct perceived through ICT use. To this end, an exploratory and transversal study has been carried out in Spain on a sample of 2,346 participants. Data processing has been carried out with SPSS and EQS. The results provide evidence of the reliability and psychometric quality on the scale, which exhibits adequate consistency that facilitates its application. The confirmatory factor analysis showed a hierarchical model of three correlated factors that account for the dimensions "Satisfaction with life", "Emotional support" and "Social support", which have enough correlation to measure the personal perception of quality of life associated with ICT use and are consistent with previous psychometric studies. The results of the TICO scale indicate that more than 70% of the sample feel ICT have united their family during home confinement and more than 45% experience happy feelings when they use ICT. In home confinement, ICT use has improved users' quality of life, mainly their satisfaction with life and social and family support.

Various Techniques to Increase Keratinized Tissue for Implant Supported Overdentures: Retrospective Case Series.

Purpose. The purpose of this retrospective case series is to describe and compare different surgical techniques that can be utilized to augment the keratinized soft tissue around implant-supported overdentures. Materials and Methods. The data set was extracted as deidentified information from the routine treatment of patients at the Ashman Department of Periodontology and Implant Dentistry at New York University College of Dentistry. Eight edentulous patients were selected to be included in this study. Patients were treated for lack of keratinized tissue prior to implant placement, during the second stage surgery, and after delivery of the final prosthesis. Results. All 8 patients in this study were wearing a complete maxillary and/or mandibular denture for at least a year before the time of the surgery. One of the following surgical techniques was utilized to increase the amount of keratinized tissue: apically positioned flap (APF), pedicle graft (PG), connective tissue graft (CTG), or free gingival graft (FGG). Conclusions. The amount of keratinized tissue should be taken into consideration when planning for implant-supported overdentures. The apical repositioning flap is an effective approach to increase the width of keratinized tissue prior to the implant placement.

Grief support provided to caregivers of palliative care patients in Spain.

Grief support for relatives of patients in palliative care is recognized as a fundamental practice within palliative medicine. The aim of this research was to determine the nature and extent of grief support programs offered to relatives of patients in palliative care in Spain. A postal survey was carried out among members of the Spanish Society of Palliative Care. The members' names were obtained through the Society's 2000 Directory, which lists 160 different teams, of which 50% answered a questionnaire made up of 34 questions, some open-ended and others multiple choice. Results show that 88.6% of the services include grief support, that mainly emotional and one-to-one care is provided (92.4 and 89.9%, respectively), and that the number of psychologists and social workers in each team is limited. The risk factors most commonly taken into account by professionals are: absence of family support (36.92%) and the bereaved's case history (21.54%); while the most widely used diagnostic criteria for complicated bereavement are blame and depression (12.5 and 11.36%). In conclusion, it can be seen that bereavement services are not completely consolidated in Spain and there is a need for a greater variety of intervention strategies.

[IgA antibody detection and PCR as first options in the diagnosis of perinatal HIV-1 infection]. / Detección de anticuerpos IgA y PCR como primeras opciones en el diagnóstico de infección perinatal por el VIH-1.

OBJECTIVE: To evaluate the sensitivity and specificity of the polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA) and IgA-specific immunoblot assays as ancillary methods to diagnose human immunodeficiency virus (HIV-1) perinatal infection. MATERIAL AND METHODS: A comparative study was conducted between February and October 2001 at the Human Retrovirus Research Unit of Mexico's National University. Ninety infected and 153 non-infected children were included in the study. Viral cultures were the gold standard tests. Standardized PCR for a conserved region of the gag gene and HIV-specific IgA antibody using ELISA and immunoblot were used. Statistical analysis of results was performed with SPSS 10.0. RESULTS: IgA ELISA sensitivity and specificity were 61.1% and 90.8%, respectively. Immunoblot had a sensitivity of 82.2% and a specificity of 95.4%. PCR had an overall sensitivity of 98.3% and a specificity of 100% with only one false negative result. If both assays were run, the sensitivity increased to 100% and the specificity to 96%. CONCLUSIONS: A very high sensitivity and specificity is reached when using together PCR and IgA immunoblot; these assays are useful for perinatal diagnosis of HIV-1.

Trichomonas vaginalis: in vitro attachment and internalization of HIV-1 and HIV-1-infected lymphocytes.

Sexually transmitted diseases (STDs) caused by bacteria and protozoa play an important role in the epidemiology of human immunodeficiency virus (HIV-1) infection. Human trichomoniasis, produced by the protozoan parasite Trichomonas vaginalis, is one of the most common STDs, and is a cause of mucosal lesions in the urogenital tract, which may increase the risk for HIV infection. However, there are no reports concerning the outcome of in vitro interactions between HIV particles and trichomonads. Therefore, we incubated T. vaginalis with three subtypes of HIV-1 (A, B, and D), as well as with HIV-1-infected lymphocytes, and analyzed the interactions with immunofluorescence microscopy and transmission electron microscopy. Our results demonstrated that HIV-1 particles attach and are incorporated into T. vaginalis through endocytic vesicles and are degraded within cytoplasmic vacuoles in approximately 48 h. There was no ultrastructural evidence of HIV-1 replication in trichomonads. These results demonstrated that trichomonads may internalize and harbor HIV-1 particles for short periods of time. In addition, under in vitro conditions, T. vaginalis ingests and digests HIV-1-infected lymphocytes.

HIV-1 inhibitory compounds from Calophyllum brasiliense leaves.

The hexane, acetone and methanol extracts of Calophyllum brasiliense leaves were fractionated following a three bioassay guide: high HIV-1 RT inhibition, low cytotoxicity on MT2 cells and high inhibition of HIV-1 IIIb/LAV replication. This led to the isolation of three anti HIV-1 dipyranocoumarins: calanolides A and B and soulattrolide. In contrast, other isolated compounds such as apetalic acid, isoapetalic acid, a structural isomer of isoapetalic acid, friedelin, canophyllol and amentoflavone were devoid of HIV-1 RT inhibitory activity. Calanolide C was also obtained as a natural product and showed moderate inhibitory properties.

HIV-1 inhibition by extracts of Clusiaceae species from Mexico.

The organic plant extracts of 21 species of Clusiaceae from Mexico were screened for anti HIV-1 reverse transcriptase activity in a non-radioactive immuno colorimetric assay. The extracts of 5 species (23.8%) exhibited significant inhibition (> or =70%) of HIV-1 RT activity; of these, only 4 extracts showed reduced toxicity to human lymphocytic MT2 cells and were further tested as inhibitors of HIV-1 IIIb/LAV replication in a cellular system. The best extracts were Calophyllum brasiliense (hexane) and Clusia quadrangula (CH(2)Cl(2)-MeOH) which inhibited HIV-1 RT (IC(50)=29.6 microg/ml and 42 microg/ml), and showed an EC(50)=92.5 microg/ml and 91 microg/ml, respectively, on MT2 cells. However, only Calophyllum brasiliense hexane extract showed significant inhibition on viral replication (ED(50)=37.1 microg/ml), while Clusia quadrangula was less active (ED(50)=124 microg/ml). These results support the idea that plant extracts represent a valuable source of potential anti HIV compounds.

Detección de anticuerpos IgA y PCR como primeras opciones en el diagnóstico de infección perinatal por el VIH-1 / IgA antibody detection and PCR as first options in the diagnosis of perinatal HIV-1 infection

OBJETIVO: Evaluar la sensibilidad y especificidad de la reacción en cadena de la polimerasa y de las pruebas de ELISA e inmunoblot para anticuerpos IgA específicos, como únicos métodos en el diagnóstico de infección perinatal del VIH-1. MATERIAL Y MÉTODOS: Estudio de evaluación comparativa, efectuado entre febrero y octubre de 2001 en la Unidad de Investigación en Retrovirus Humanos de la Universidad Nacional Autónoma de México. Se incluyeron 90 muestras de niños infectados y 153 de no infectados. El cultivo viral fue la prueba de referencia. Se estandarizaron ensayos de ELISA e inmunoblot y la reacción en cadena de la polimerasa para una región conservada del gen gag. Se analizaron los resultados utilizando el paquete informático SPSS 10.0. RESULTADOS: La sensibilidad y especificidad de la prueba de ELISA fueron 61.1 y 90.8 por ciento, respectivamente. En el inmunoblot encontramos 82.2 y 95.4 por ciento, respectivamente, en tanto que la reacción en cadena de la polimerasa demostró tener sensibilidad de 98.3 por ciento y especificidad de 100 por ciento con sólo un falso negativo. CONCLUSIONES: Los resultados indican que la realización simultánea de la reacción en cadena de la polimerasa y el inmunoblot para IgA logran sensibilidad y especificidad de 100 por ciento y 96 por ciento, respectivamente, por lo cual se consideran útiles para el diagnóstico perinatal de VIH-1.

Transmembtane glycoprotein cross reactive HIV-1/HIV-2 epitope / Epítopo de reactividad cruzada en las glicoproteínas transmembranales de HIV-1/HIV-2

Epítopo de reactividad cruzada en las glicoproteínas transmembranales de HIV-1/HIV-2. Introducción. En México se ha reportado una alta reactividad cruzada (24 por ciento) entre las glicoproteínas transmembranales del HIV-1 y HIV-2. Material y métodos. En este estudio, se sintetizó y se utilizó como antígeno para un ELISA, el péptido UIRH1 que corresponde a la región aminoterminal de la glicoproteína transmembranal del HIV-2 (aa629-652). La especificidad de la reacción se confirmó mediante un ensayo de competencia. Resultados. Los sueros de personas infectadas con el HIV-1 que no presentaron reacción cruzada con la gp32 del HIV-2 dieron valores de absorbancias similares a los que se obtuvieron de las personas seronegativas (1.1 veces) mientras que los sueros positivos al HIV-1 que presentaron reactividad cruzada dieron 2.8 veces la absorbancia de los negativos. Discusión. Proponemos que esta región transmembranal es responsable de la reactividad cruzada observada en ensayos de inmunoblot en individuos infectados con el HIV-1 en México.

Evaluación de ensayo de detección de anticuerpos anti-HIV / Half evaluated assays in detection of anti-HIV

Se realizó una evaluación comparativa de diez estuches comerciales de detección de anticuerpos anti-HIV. Tres de los ensayos eran pruebas de tipo rápidas/simples y 7 de ellos eran ensayos tipo ELISA. La mitad eran ensayos de primera generación (lisado viral) y la otra mitad eran de segunda o tercera generación (antígeno recombinante). Cinco de ellos eran ensayos también para anticuerpos contra HIV-2. El panel de evaluación original se conformó con 541 muestras de suero, las cuales fueron evaluadas en su totalidad por inmunoblot; 10 muestras que resultaron indeterminadas fueron eliminadas en los cálculos de los diferentes parámetros. Nueve de los ensayos presentaron una sensibilidad de 100 por ciento y 4 de ellos además resultaron 100 por ciento específicos. Con objeto de evaluar los límites de detección de los distintos ensayos, se incluyeron además 9 muestras de 3 sueros conocidos positivos en diluciones, encontrándose que 4 de los ensayos detectan igual o mayor dilución que inmunoblot y que 6 tienen niveles de detección menor que dicho ensayo. El análisis gráfico y los valores delta positivo y delta negativo de los ensayos de tipo ELISA con igual sensibilidad permitió diferenciar los estuches en términos de la probabilidad de identificar correctamente los especímenes positivos y negativos. También se reporta la variabilidad en interpretación de los ensayos subjetivos y la facilidad de realización de cada ensayo

Análisis numérico de imágenes digitalizadas de western blot. El caso del VIH / Numeric analysis of digitalized images of western blot. The case of VIH

El presente trabajo explora la digitalización de imágenes de "western blot" (WB) para extraer mayor información acerca de la respuesta inmune humoral del paciente infectado por el virus de la inmunodeficiencia adquirida humana (VIH) y analizar de manara multivariada los datos obtenidos. Se realizó la digitalización y análisis de las imágenes de WB de 115 sueros. Con estos datos se hicieron análisis tanto cualitativos: dendograma y análisis de componentes principales (ACP), como cuantitativos: ACP con el total de bandas tomando sólo los antígenos propios del virus o utilizando los antígenos que no pertenecen al virus. Los resultados demuestran la factibilidad de diagnosticar de forma mecánica un número grande de imágenes de WB. Tanto el dendograma como el ACP cualitativo separaron, de manera adecuada, imágenes blancas, imágenes con menos de cuatro bandas e imágenes con patrones más complejos. El análisis cuantitativo, que conserva más información, separa perfectamente imágenes de diagnóstico negativo, indeterminado y positivo. Además, se encontró que las imágenes con patrones complejos correlacionan más con individuos asintomáticos. Este análisis reveló también la existencia de banda que no parecen corresponder a proteínas virales, mismas que pudieran corresponder a autoantígenos o antígenos cruzados entre el VIH y el ser humano, dando cauce a autoinmunidad. El análisis digital de imágenes de WB en el caso del VIH, prueba así su gran utilidad en el diagnóstico de caso y en el seguimiento de la evolución y patogenia de la enfermedad

Primary B cell lymphoma of the rectum in a patient coinfected with HIV-1 and HTLV-I

Este artículo describe el caso clínico de un enfermo con SIDA coinfectado por HTLV-1 que desarrolló un linfoma B del recto, variedad sarcoma inmunoblástico con diferenciación plasmacitoide. Las células malignas mostraron arreglo clonal de los genes de las CP (Jh) y CLk. La infección por el VEB fue demostrada serológicamente y por hibridación de un monitor específico con el ADN genómico de las células cancerosas. No se detectaron secuencias de HTLV-1 en el seno del tumor. Una remisión clínica completa, pero temporal, se obtuvo con siete ciclos de VACO-B. El enfermo abandonó el tratamiento y la sobrevida se desconoce.