35 research outputs found
Highly fluorescent C-dots obtained by pyrolysis of quaternary ammonium ions trapped in all-silica ITQ-29 zeolite
[EN] C-dots obtained in the homogeneous phase may exhibit a broad particle size distribution. The formation of C-dots within nanometric reaction cavities could be a methodology to gain control on their size distribution. Among the various possibilities, in the present work, the cavities of small pore size zeolites have been used to confine C-dots generated by the pyrolysis of the organic structure directing agent present in the synthesis of these crystalline aluminosilicates. To explore this methodology, ITQ-29 zeolite having a Linde type A (LTA) structure was prepared as pure silica with 4-methyl-2,3,6,7-tetrahydro-1H, 5H-pyrido[3.2.1-ij] quinolinium as the organic structure directing agent. Pyrolysis under an inert atmosphere at 550 degrees C of a pure-silica ITQ-29 sample (cubic particles of 4 mu m edge) renders a highly fluorescent zeolite containing about 15 wt% of the carbonised residue. While another small pore zeolite, ITQ-12 (ITW), also renders photoluminescent C-dots under similar conditions, medium or large pore zeolites, such as silicalite (MFI) or pure silica Beta (BEA), failed to produce fluorescent powders under analogous thermal treatment and only decomposition and complete removal of the corresponding quaternary ammonium ion templates was observed for these zeolites. The dissolution of the pyrolysed ITQ-29 zeolite framework and the extraction of the carbon residue with ethyl acetate have allowed the characterisation of C-dots with particle sizes between 5 and 12 nm and a photoluminescence quantum yield of 0.4 upon excitation at 350 nm that is among the highest reported for non-surface functionalized C-dots. Photoluminescence varies with the excitation wavelength and is quenched by oxygen. Pyrolysed ITQ-29 powders can act as fluorescent oxygen sensors.Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa and CTQ2012-32315) and Generalidad Valenciana (Prometeo 2012-014) is gratefully acknowledged.García Baldoví, H.; Valencia Valencia, S.; Alvaro Rodríguez, MM.; Abdullah, AM.; García Gómez, H. (2015). Highly fluorescent C-dots obtained by pyrolysis of quaternary ammonium ions trapped in all-silica ITQ-29 zeolite. Nanoscale. 7(5):1744-1752. https://doi.org/10.1039/C4NR05295AS174417527
Soluble concentrations of the terminal complement complex C5b-9 correlate with end-organ injury in preeclampsia
Q3Q1Pacientes embarazadas hipertensasObjective:
We sought to determine if soluble levels of C5b-9, the terminal complement complex, correlate with end-organ injury in preeclampsia.
Study Design:
Project COPA (Complement and Preeclampsia in the Americas), a multi-center observational study in Colombia from 2015 to 2016, enrolled hypertensive pregnant women into four groups: chronic hypertension, gestational hypertension, preeclampsia, and preeclampsia with severe features. Trained coordinators collected clinical data, blood and urine. End-organ injury was defined by serum creatinine ≥ 1.0 mg/dl, aspartate transaminase ≥ 70U/L, platelet count < 150,000/µl, or lactate dehydrogenase ≥ 500 U/L. Data were analyzed by χ2 or Fisher’s exact test with significance at P < 0.05.
Main Outcome Measure:
C5b-9 concentrations in plasma and urine, using enzyme linked immunosorbent assays.
Results:
In total, 298 hypertensive participants were enrolled. Plasma and urine C5b-9 levels were measured in all participants and stratified by quartile (Q1-4), from lowest to highest C5b-9 concentration. Participants with low plasma C5b-9 levels (Q1) were more likely to have end-organ injury compared to those with higher levels (Q2-Q4) [platelet count < 150,000/μl (20.8% vs. 8.4%, P = 0.01); elevated serum creatinine ≥ 1.0 mg/dl (14.9% vs. 4.5%, P = 0.009)]. In contrast, participants with high urinary C5b-9 levels (Q4) were more likely to have end-organ injury compared to those with lower levels (Q1-Q3) [platelet count < 150,000/μl (19.7% vs. 7.4%, P = 0.003); elevated serum creatinine ≥ 1.0 mg/dl (12.3% vs. 4.4%, P = 0.025)].
Conclusion:
We identified a pattern of increased urine and low plasma C5b-9 levels in patients with preeclampsia and end-organ injury. Soluble C5b-9 levels may be used to identify complement-mediated end-organ injury in preeclampsia.https://orcid.org/0000-0001-6822-0374Revista Internacional - IndexadaA1N
Evaluación fisicoquímica de frutos del germoplasma de guayaba conservado en Agrosavia, Colombia
El guayabo (Psidium guajava) es una especie de importancia económica en diferentes países del mundo, especialmente por la producción de frutos comestibles, su alto contenido de vitamina C y su maleabilidad para la transformación agroindustrial. La Colección Colombiana de Guayaba conservada en Agrosavia resguarda la variabilidad de esta especie y algunas relacionadas, no obstante, se tienen estudios parciales que limitan el potencial de su uso. El objetivo fue evaluar y caracterizar las variables fisicoquímicas del fruto en busca de identificar accesiones con atributos de interés agroindustrial. Para ello se evaluaron 29 descriptores (17 cuantitativos y 12 cualitativos) en frutos de las 41 accesiones que componen la colección. La información obtenida fue sometida a un análisis de componentes principales y a otro de correspondencia múltiple. En los análisis cualitativos se encontró que el germoplasma evaluado se caracteriza por tener frutos de forma convexa con cuello, pulpa de color rosado con textura granulosa, color verde predominante en el epicarpio, inserción de pedúnculo oblicua, semillas de forma oblonga y forma de ápice y fruta con ombligo en el eje polar. En los análisis cuantitativos, 20 accesiones presentaron porcentajes de pulpa entre el 97 % y el 99 %, donde el contenido de sólidos solubles totales de la población evaluada fluctuó entre 4,3 y 10,5 °Brix; la relación de vitamina C osciló entre 28,3 y 208,26 mg/100 g de muestra y el peso del fruto estuvo entre 18,84 y 363,53 g, siendo las accesiones 25, 33 y 36 seleccionadas como promisorias
Experiencias psicosociales en la transición hacia la paz profunda en Colombia
El presente trabajo se propone articular una reflexión sobre algunos retos que enfrenta la investigación psicosociológica de cara al acompañamiento, soporte e inclusive orientación de los procesos y dinámicas psicosociales de construcción de
paz. Se inspira en el conjunto de trabajos aquí incluidos, pero no se basa en ellos de manera exclusiva ni prioritaria; busca, más bien, ofrecer un conjunto de criterios para la reflexión crítica en un momento histórico único por las oportunidades de incidencia que se le abren, para el mejoramiento de la investigación psicosociológica.
Se espera animar a su vez nuevas prácticas reflexivas que contribuyan a incrementar
la relevancia y la pertinencia de este tipo de investigación, a elegir caminos fecundos
tanto para la definición de programas de investigación como de decisiones curriculares
cruciales para la formación avanzada de nuevas generaciones de profesionales que
contribuyan en los próximos años a este fundamental reto de construcción de la paz
profunda en Colombia. El libro es una contribución a las reflexiones epistemológicas,
metodológicas y éticas en un momento histórico y político crucial para el país, en el
que desafortunadamente no vemos aún materializarse el deseo de paz en la Colombia profunda. Pero, aún en medio de las vicisitudes y las promesas por cumplir de una paz estable y duradera, cobra sentido y mayor relevancia el saber psicosociológico.PRÓLOGO. UN LEGADO CERCANO Y COLABORATIVO.
INTRODUCCIÓN. INVESTIGAR LA TRANSICIÓN DESDE LA PERSPECTIVA PSICOSOCIAL. RETOS PARA EL DISEÑO DE INVESTIGACIÓN.
CAPÍTULO 1. TRANSFORMACIONES SOCIALES Y LAS LUCHAS PRESENTES DE UN TERRITORIO SOBREVIVIENTE DEL CONFLICTO ARMADO.
CAPÍTULO 2. NUEVOS ESCENARIOS DE PARTICIPACIÓN POLÍTICA JUVENIL: CONSTRUYENDO PAZ A TRAVÉS DEL ARTE.
CAPÍTULO 3. IDENTIDAD NARRATIVA EN PERSONAS EN PROCESO DE REINTEGRACIÓN (PPR) CAMBIOS Y PERMANENCIAS DESDE LA EXPERIENCIA DE SÍ DE DOS LIDERESAS COMUNITARIAS.
CAPÍTULO 4. REPERTORIOS INTERPRETATIVOS SOBRE LA RECONCILIACIÓN DESAFÍOS EN LA IMPLEMENTACIÓN DEL ACUERDO DE PAZ.
CAPÍTULO 5. POTENCIANDO LA SUBJETIVIDAD POLÍTICA DESDE UNA EXPERIENCIA DE EDUCACIÓN PARA LA PAZ.1ª ed
An estimate of the number of tropical tree species
The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher’s alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between ∼40,000 and ∼53,000, i.e. at the high end of previous estimates. Contrary to common assumption, the Indo-Pacific region was found to be as species-rich as the Neotropics, with both regions having a minimum of ∼19,000–25,000 tree species. Continental Africa is relatively depauperate with a minimum of ∼4,500–6,000 tree species. Very few species are shared among the African, American, and the Indo-Pacific regions. We provide a methodological framework for estimating species richness in trees that may help refine species richness estimates of tree-dependent taxa
Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2
The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
Educación ambiental y sociedad. Saberes locales para el desarrollo y la sustentabilidad
EL LIBRO PERMITE REFLEXIONAR SOBRE LA IMPORTANCIA DE FOMENTAL LA EDUCACIÓN AMBIENTAL PARA RESOLVER LA PROBLEMÁTICA AMBIENTALEL LIBRO PRESENTA DIFERENTES TRABAJOS QUE ESTUDIAN EL TEMA D ELA SUSTENTABILIDAD, ENFATIZANDO LA IMPORTANCIA DE LA EDUCACIÓN AMBIENTAL Y LA TRANSDISCIPLINANINGUN
Vocabulario de la sociedad civil, la ruralidad y los movimientos sociales en América Latina
El Vocabulario de la Sociedad Civil, la Ruralidad y los
Movimientos Sociales en América Latina tiene como
objetivo desarrollar vocablos relacionados con temas
de gran trascendencia para la vida colectiva de la
población Latinoamericana; pretende introducir a
estudiantes, personas del ámbito académico y activistas
en la comprensión de estas categorías de análisis.
A través de la mirada de 70 especialistas que
participaron en este vocabulario, es posible comprender
muchos de los términos que se utilizan dentro de
la investigación social y áreas relacionadas con las
ciencias políticas, ambientales y rurales, a partir de
una mayor explicación y detalle. Es por ello que se
inserta este trabajo desde una mirada colectiva y
amplia de los conceptos que se exponen.
En este libro podrá encontrar las ideas de varios autores
y autoras de distintas universidades, con una visión
multi, inter y transdisciplinaria. El esfuerzo que se
realizó para conjuntar varios términos y analizar su
compleja red de interpretaciones, permitirá que este
manuscrito pueda ser consultado por estudiantes,
personas del ámbito científico-académico, y ciudadanía;
porque contiene el estado del arte, la historia del
paulatino avance de múltiples conceptos y su vigencia
en el contexto actual
Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions
Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41–6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000–2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p < 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2–79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999–2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics
Late development of a lamellar macular hole after the spontaneous separation of vitreoretinal traction: Case report
Purpose: To report a case of epiretinal macular membrane and a lamellar macular hole developing after the spontaneous separation of an idiopathic vitreoretinal traction. Methods: Retrospective, observational, long follow-up of a case evaluated and documented with optical coherence tomography and managed with current therapies including pars plana vitrectomy. Results: Good anatomic and functional results with stable 20/30 best-corrected visual acuity. Conclusions: The natural course of idiopathic vitreomacular traction has been documented during prolonged observation after its spontaneous separation from the fovea leading to the development of an epiretinal membrane and a lamellar macular hole. © 2016 Wichtig Publishing