Determinación del efecto de la preparación y distribución de paladio soportado en Gamma Alúmina en una reacción de oxidación parcial de un alcohol

This work analyzes the effect of the time of impregnatingand previous state of the support in the distribution ofPd/ -Al O prepared by impregnation method varying 2 3time between 1 and 5 hours and considering twoprevious states (wet and dry). The characterization of thesupport and the catalysts and after using them in a PBRfor the partial oxidation of the Isopropanol to atemperature of 180°C and two time factors W/F (15 y 8 AOgcat/mol/h) was made by means of techniques like X-RayDiffraction (XRD), superficial area by BET method,Scanning Electron Microscopy (SEM), among others. Theproducts of the reaction were quantified by means of GasChromatography. Uniform and Egg shell distributionswere obtained, uniform catalysts activated by reductionand calcination were used.Se analizó el efecto del tiempo de impregnación y estadoprevio del soporte en la distribución del Pd/ -Al O 2 3preparado mediante la técnica de impregnaciónconsiderando dos tiempos (1 y 5 horas) y variando elestado previo (húmedo y seco). Se caracterizó el soportey los catalizadores antes y después de usarlos en unreactor de lecho empacado (PBR) para la oxidaciónparcial del Isopropanol a una temperatura de 180°C ydos factores de tiempo W/F (15 y 8 gcat/mol/h). Las AOtécnicas de caracterización usadas fueron Difracción deRayos X (XRD), área superficial por el método BET, yMicroscopía Electrónica de Barrido (SEM), entre otras.Los productos de la reacción fueron cuantificadosmediante Cromatografía de Gases. Se obtuvierondistribuciones uniforme y cáscara de huevo, se usaroncatalizadores uniformes activados por reducción ycalcinación

El ciclo mortal de los habitantes de calle en Bogotá. Teorías, olvidos, políticas y desenlaces fatales

El fenómeno de la habitación de la calle es universal, si bien se presenta con mayor intensidad en las metrópolis tercermundistas. Un estado del arte reconstruido desde una perspectiva pluridisciplinar permite advertir ciertos olvidos acerca de sus determinantes. En este artículo se plantea la hipótesis de que la entrada a la habitación en la calle en Bogotá se realiza a cualquier edad y que, cuando ello ocurre, se anticipa la etapa de desesperanza con la que se inicia el ciclo mortal de las personas

O ciclo mortal dos moradores de rua em Bogotá. Teorias, esquecimento, políticas e resultados fatais

The deadly cycle of street dwellers in Bogotá Theories, forgetting, comparisons, policies and fatal outcomes The phenomenon of street homelessness is universal, although it occurs with greater intensity in the Third World metropolises. A state of the art reconstructed from a multidisciplinary perspective allows to notice certain forgetfulness about its determinants. This article hypothesizes that the entrance to habitability on the street in Bogotá takes place at any age, and that when this happens, the stage of despair with which the mortal cycle begins is anticipated.El fenómeno de la habitación de la calle es universal, si bien se presenta con mayor intensidad en las metrópolis tercermundistas. Un estado del arte reconstruido desde una perspectiva pluridisciplinar permite advertir ciertos olvidos acerca de sus determinantes. En este artículo se plantea la hipótesis de que la entrada a la habitación en la calle en Bogotá se realiza a cualquier edad y que, cuando ello ocurre, se anticipa la etapa de desesperanza con la que se inicia el ciclo mortal de las personas.O fenômeno da moradia de rua é universal, embora ocorra com maior intensidade nas metrópoles terceiromundistas. Um estado da arte reconstruído a partir de uma perspectiva multidisciplinar permite perceber certo esquecimento de seus determinantes. Este artigo traz a hipótese de que a entrada na moradia de rua em Bogotá (Colômbia) ocorra em qualquer idade e que, quando isso acontece, se antecipa o estágio de falta de esperança com o qual começa o ciclo mortal das pessoas&nbsp

Inmunodiagnóstico de la infección chagásica por ELlSA

Demonstration of the infectious agent is the gold standard in parasitic infections but this is not always feasible.Thus diagnosis is confirmed through Trypanosoma cruziantibody detection (in the case of Chagas'disease) by using serological assays. In this study the enzyme immunoassay (ELISA) for the diagnosis of Trypanosoma cruz; infection was standardised and assessed. 595 serum samples taken from people coming from the endemic area of Guateque, Boyaca, were tested against T. cruziepimastigotes from the IRHOlCOl69lGuateque Colombian strain, using both the immunofluorescent antibody test (IFAT) and the ELlSA test. Analysis of the ELlSA test's validity was done through estimation of the area under the receptor-operator curve (ROC). The optimum conditions for the ELlSA test were an antigen concentration of 0.75 ygrlml and sample dilution of 1:1000. The assay's sensitivity for cut-off points of 0.2, 0.3, 0.4 and 0.5 was 0.99, 0.99, 0.98 and 0.93 and its specificity for the same cut-off points was 0.94, 0.96, 0.98 and 0.98.The ELlSA test is a valid and useful test, not only because of its sensitivity and specificity but also because the estimation of the area under the receptor-operator curve (ROC) was 0.9952, this being very close to the ideal. The ELlSA test is better than the IFAT test for detection of Trypanosoma cruzi infection antibodies and could be used in seroepidemiological sur'veys in areas of moderate to high prevalence.La demostración del agente infeccioso es la regla de oro en las parasitosis, pero, esto no siempre es factible. Por ello, en la infección chagásica ce recurre a la detección de anticuerpos contra Trypanosoma cruzi siendo las pruebas serodiagnósticas de gran utilidad. El presente estudio estandarizó y evaluó la prueba inmunoenzimática Elisa para el inmunodiagnóstico de la infección chagásica. Se confrontaron 595 muestras de suero de pacientes provenientes de Guateque, Boyacá, zona endémica de la enfermedad de Chagas, con epimastigotes de Tcruzide la cepa colombiana IRHOICO/69/Guateque utilizando las pruebas inmunodiagnósticas de inmunofluorescencia indirecta (IFI), prueba de referencia, y el ensayo inmunoenzimático ELISA. El análisis de la validez de ésta se realizó mediante el cálculo del área bajo la curva del operador receptor (ROC) como medida de la exactitud (validez). Las condiciones óptimas de la prueba ELlSA fueron: antígeno 0,75 pglml y dilución de la muestra 1:1.000. El ensayo del estudio según los puntos de corte 0,2, 0,3, 0,4 y 0,5 ofrece una sensibilidad de 0,99, 039, 0,98 y 0,93 y una especificidad de 0,94, 0,96, 0,98 y 0,98, respectivamente. El ELlSA del estudio se muestra como una prueba válida no sólo por la sensibilidad y especificidad sino porque el análisis del área bajo la curva ROC fue de 0,9952 que es muy cercano al ideal. La prueba de ELlSA es superior a la de IFI para la detección de anticuerpos contra 1 cruzi y podría ser utilizada en estudios seroepidemiológicos en zonas de alta y moderada prevalencia

Tissue-Associated Bacterial Alterations in Rectal Carcinoma Patients Revealed by 16S rRNA Community Profiling

Sporadic and inflammatory forms of colorectal cancer (CRC) account for more than 80% of cases. Recent publications have shown mechanistic evidence for the involvement of gut bacteria in the development of both CRC-forms. Whereas, colon and rectal cancer have been routinely studied together as CRC, increasing evidence show these to be distinct diseases. Also, the common use of fecal samples to study microbial communities may reflect disease state but possibly not the tumor microenvironment. We performed this study to evaluate differences in bacterial communities found in tissue samples of 18 rectal-cancer subjects when compared to 18 non-cancer controls. Samples were collected during exploratory colonoscopy (non-cancer group) or during surgery for tumor excision (rectal-cancer group). High throughput 16S rRNA amplicon sequencing of the V4V5 region was conducted on the Ion PGM platform, reads were filtered using Qiime and clustered using UPARSE. We observed significant increases in species richness and diversity in rectal cancer samples, evidenced by the total number of OTUs and the Shannon and Simpson indexes. Enterotyping analysis divided our cohort into two groups, with the majority of rectal cancer samples clustering into one enterotype, characterized by a greater abundance of Bacteroides and Dorea. At the phylum level, rectal-cancer samples had increased abundance of candidate phylum OD1 (also known as Parcubacteria) whilst non-cancer samples had increased abundance of Planctomycetes. At the genera level, rectal-cancer samples had higher abundances of Bacteroides, Phascolarctobacterium, Parabacteroides, Desulfovibrio, and Odoribacter whereas non-cancer samples had higher abundances of Pseudomonas, Escherichia, Acinetobacter, Lactobacillus, and Bacillus. Two Bacteroides fragilis OTUs were more abundant among rectal-cancer patients seen through 16S rRNA amplicon sequencing, whose presence was confirmed by immunohistochemistry and enrichment verified by digital droplet PCR. Our findings point to increased bacterial richness and diversity in rectal cancer, along with several differences in microbial community composition. Our work is the first to present evidence for a possible role of bacteria such as B. fragilis and the phylum Parcubacteria in rectal cancer, emphasizing the need to study tissue-associated bacteria and specific regions of the gastrointestinal tract in order to better understand the possible links between the microbiota and rectal cancer.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Programa Nacional de Apoio à Atenção Oncológica (Pronon)Associacao Beneficiente Alzira Denise Hertzog Silva (ABADHS)CIPE AC Camargo Canc Ctr, Med Genom Lab, Sao Paulo, BrazilUniv Sao Paulo, Inst Quim, Dept Bioquim, Sao Paulo, BrazilUniv Sao Paulo, Cursode Posgrad Bioinformat, Sao Paulo, BrazilAC Camargo Canc Ctr, Dept Pelv Surg, Sao Paulo, BrazilAC Camargo Canc Ctr, Dept Pathol, Sao Paulo, BrazilUniv Fed Sao Paulo, Coll Med, Dept Gynecol, Lab Mol Gynecol, Sao Paulo, BrazilHosp Sirio Libane, Ctr Oncol Mol, Sao Paulo, BrazilUniv Sao Paulo, Food Res Ctr FoRC, Fac Ciencias Farmaceut, Dept Alimentos & Nutr Expt, Sao Paulo, BrazilAC Camargo Canc Ctr, Dept Clin Oncol, Sao Paulo, BrazilAC Camargo Canc Ctr, Lab Computat Biol & Boinformat, Sao Paulo, BrazilVirginia Tech, Biocomplex Inst, Blacksburg, VA USAUniv Sao Paulo, Fac Med, Inst Psychiat, Lab Neurosci LIM Alzira Denise Hertzog Silva 27, Sao Paulo, BrazilLaboratory of Molecular Gynecology, Department of Gynecology, Medicine College, Universidade Federal de São Paulo (UNIFESP), São Paulo, BrazilFAPESP: 2015/01507-7FAPESP: 2013/07914-8CAPES: 88887.062078/2014-00CAPES: 3385/2013PRONON: 25000.055.167/2015-23Web of Scienc

Proliferation of Tau 304-380 Fragment Aggregates through Autocatalytic Secondary Nucleation.

The self-assembly of the protein tau into neurofibrillary tangles is one of the hallmarks of Alzheimer's disease and related tauopathies. Still, the molecular mechanism of tau aggregation is largely unknown. This problem may be addressed by systematically obtaining reproducible in vitro kinetics measurements under quiescent conditions in the absence of triggering substances. Here, we implement this strategy by developing protocols for obtaining an ultrapure tau fragment (residues 304-380 of tau441) and for performing spontaneous aggregation assays with reproducible kinetics under quiescent conditions. We are thus able to identify the mechanism of fibril formation of the tau 304-380 fragment at physiological pH using fluorescence spectroscopy and mass spectrometry. We find that primary nucleation is slow, and that secondary processes dominate the aggregation process once the initial aggregates are formed. Moreover, our results further show that secondary nucleation of monomers on fibril surfaces dominates over fragmentation of fibrils. Using separate isotopes in monomers and fibrils, through mass spectroscopy measurements, we verify the isotope composition of the intermediate oligomeric species, which reveals that these small aggregates are generated from monomer through secondary nucleation. Our results provide a framework for understanding the processes leading to tau aggregation in disease and for selecting possible tau forms as targets in the development of therapeutic interventions in Alzheimer's disease

Clima, ciudades y biodiversidad: revisión de producción científica

International institutions have highlighted the necessity to generate knowledge about urban biodiversity, their ecological interactions and the effects of climate change. However, these knowledge remains unknown for the majority of cities around the world. The aim of this study was to determine what information has been produced in relation to climate and urban biodiversity nationally and internationally. We conducted a literature search using Scopus and databases of national universities and research institutes. We found 725 publications internationally and 115 publications in Colombia. We found an increase in the number of publications regarding urban biodiversity in the last 20 years. Internationally, most studies were conducted in Europe and 86 % of the publications focused on the study of plants in green areas and urban forests. In Colombia, almost half of the publications compiled were undergraduate theses and in general 45 % of publications focused on characterizations of species in urban ecosystems. Governmental institutions need to develop strategies that encourage research towards urban biodiversity and their ecological functions in climate change scenarios.Instituciones internacionales han resaltado la necesidad de generar conocimiento entorno a la biodiversidad urbana, sus interacciones ecológicas y los efectos del cambio climático, sin embargo, son pocas las ciudades las que lo han hecho. El objetivo de este artículo fue determinar el estado del arte sobre las relaciones clima y biodiversidad urbana a nivel nacional e internacional. Se realizó una búsqueda bibliográfica por Scopus y en las bases de datos de las principales instituciones de Colombia. A nivel internacional se encontraron 725 publicaciones y a nivel nacional 115. Se encontró una tendencia de aumento en el número de publicaciones en los últimos 20 años. A nivel internacional la mayoría de estudios fueron realizados en Europa y el 86 % de las publicaciones se enfocaron en plantas en espacios verdes y bosques urbanos. En Colombia, la mayoría de la información proviene de trabajos de grado y el 45 % se concentraron en la caracterización de especies. Son pocas las publicaciones que han evaluado el impacto del cambio climático en la biodiversidad, especialmente a nivel nacional. Se requiere el desarrollo de una agenda interinstitucional para el estímulo de investigaciones en torno a la biodiversidad urbana y su funcionamiento en escenarios de cambio climático

Seroprevalencia de infección por trypanosoma cruzi en población urbana y rural de guateque (colombia)

Se realizó un estudio de corte transversal para determinar la seroprevalencia de la infección chagásica en personas que viven en zona urbana y rural de Guateque (Boyacá). Se detectaron anticuerpos contra Trypanosoma cruzi mediante la técnica de ELISA. Se determinó la prevalencia de infección por género, grupos etáreos decenales y ubicación urbana y rural. Se calcularon los riesgos ajustados de infección mediante regresión logística no condicional incluyendo las variables mencionadas. Las prevalencias de infección variaron entre O y el 88% siendo en la zona rural del 34.5% y en la urbana del 5.3%. La prevalencia de infección por grupos etáreos no se comportó como en otros estudios. La correlación entre edad y tiempo vivido en la zona por grupo etáreo es baja pero positiva en todos los grupos de edad excepto en los de 20-29 y 30- 39, en los que fue negativa. Como hallazgo interesante se encontró un OR de 0.6 para el género masculino.A cross-sectional study was undertaken in order to determine the seroprevalence of chagasic infection in people living in the urban and rural zones of the town of Guateque, department of Boyacá. Antibodies aginst T. cruzi were detected by enzyme irnmunoassay (ELISA). The prevalence and distribution of infection according to gender, 10-year age groups and rural and urban residence were determined. Adjusted risks of infection were determined by non conditional logistic regression which included the variables already mentioned. Prevalence of infection varied from O to 88 %. In the rural zone the prevalence was 34.5 % while in the urban zone it was 5.3%. The correrelation between age and time of residence in the area, albeit low, was positive in all age groups, except for the 20-29 and 30-39 groups in which it was negative. Interestingly, a protective effect OR=0.6 for infection was found in the male gender

Human papillomavirus detection from human immunodeficiency virus-infected colombian women's paired urine and cervical samples

Infection, coinfection and type-specific human papillomavirus (HPV) distribution was evaluated in human immunodeficiency virus (HIV)-positive women from paired cervical and urine samples. Paired cervical and urine samples (n = 204) were taken from HIV-positive women for identifying HPV-DNA presence by using polymerase chain reaction (PCR) with three generic primer sets (GP5+/6+, MY09/11 and pU1M/2R). HPV-positive samples were typed for six high-risk HPV (HR-HPV) (HPV-16, -18, -31, -33, -45 and -58) and two low-risk (LR-HPV) (HPV-6/11) types. Agreement between paired sample results and diagnostic performance was evaluated. HPV infection prevalence was 70.6% in cervical and 63.2% in urine samples. HPV-16 was the most prevalent HPV type in both types of sample (66.7% in cervical samples and 62.0% in urine) followed by HPV-31(47.2%) in cervical samples and HPV-58 (35.7%) in urine samples. There was 55.4% coinfection (infection by more than one type of HPV) in cervical samples and 40.2% in urine samples. Abnormal Papanicolau smears were observed in 25.3% of the women, presenting significant association with HPV-DNA being identified in urine samples. There was poor agreement of cervical and urine sample results in generic and type-specific detection of HPV. Urine samples provided the best diagnosis when taking cytological findings as reference. In conclusion including urine samples could be a good strategy for ensuring adherence to screening programs aimed at reducing the impact of cervical cancer, since this sample is easy to obtain and showed good diagnostic performance