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1.
Environ Sci Technol ; 55(5): 3201-3209, 2021 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-33566595

RESUMEN

A large concern with estimates of climate and health co-benefits of "clean" cookstoves from controlled emissions testing is whether results represent what actually happens in real homes during normal use. A growing body of evidence indicates that in-field emissions during daily cooking activities differ substantially from values obtained in laboratories, with correspondingly different estimates of co-benefits. We report PM2.5 emission factors from uncontrolled cooking (n = 7) and minimally controlled cooking tests (n = 51) using traditional chulha and angithi stoves in village kitchens in Haryana, India. Minimally controlled cooking tests (n = 13) in a village kitchen with mixed dung and brushwood fuels were representative of uncontrolled field tests for fine particulate matter (PM2.5), organic and elemental carbon (p > 0.5), but were substantially higher than previously published water boiling tests using dung or wood. When the fraction of nonrenewable biomass harvesting, elemental, and organic particulate emissions and modeled estimates of secondary organic aerosol (SOA) are included in 100 year global warming commitments (GWC100), the chulha had a net cooling impact using mixed fuels typical of the region. Correlation between PM2.5 emission factors and GWC (R2 = 0.99) implies these stoves are climate neutral for primary PM2.5 emissions of 8.8 ± 0.7 and 9.8 ± 0.9 g PM2.5/kg dry fuel for GWC20 and GWC100, respectively, which is close to the mean for biomass stoves in global emission inventories.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire Interior , Artículos Domésticos , Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/análisis , Biomasa , Culinaria , India , Material Particulado/análisis
2.
Anal Chem ; 90(21): 12493-12502, 2018 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-30293422

RESUMEN

Light-absorbing components of atmospheric organic aerosols, which are collectively termed "brown carbon" (BrC), are ubiquitous in the atmosphere. They affect absorption of solar radiation by aerosols in the atmosphere and human health as some of them have been identified as potential toxins. Understanding the sources, formation, atmospheric evolution, and environmental effects of BrC requires molecular identification and characterization of light-absorption properties of BrC chromophores. Identification of BrC components is challenging due to the complexity of atmospheric aerosols. In this study, we employ two complementary ionization techniques, atmospheric pressure photo ionization (APPI) and electrospray ionization (ESI), to obtain broad coverage of both polar and nonpolar BrC components using high-resolution mass spectrometry (HRMS). These techniques are combined with chromatographic separation of BrC compounds with high performance liquid chromatography (HPLC), characterization of their light absorption with a photodiode array (PDA) detector, and chemical composition with HRMS. We demonstrate that this approach enables more comprehensive characterization of BrC in biomass burning organic aerosols (BBOAs) emitted from test burns of sage brush biofuel. In particular, we found that nonpolar BrC chromophores such as PAHs are only detected using positive mode APPI. Meanwhile, negative mode ESI results in detection of polar compounds such as nitroaromatics, aromatic acids, and phenols. For the BrC material examined in this study, over 40% of the solvent-extractable BrC light absorption is attributed to water insoluble, nonpolar to semipolar compounds such as PAHs and their derivatives, which require APPI for their identification. In contrast, the polar, water-soluble BrC compounds, which are detected in ESI, account for less than 30% of light absorption by BrC.

3.
Ann Neurol ; 80(5): 741-753, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27666438

RESUMEN

OBJECTIVE: Cerebral small vessel disease (cSVD) is a heterogeneous group of disorders. Screening of known cSVD genes identifies the causative mutation in <15% of familial cSVD cases. We sought to identify novel causes of cSVD. METHODS: We used linkage analysis and exome sequencing to identify the causal mutation in a French cSVD family. The identified candidate gene was then screened in 202 cSVD unrelated probands, including 1 proband from the first reported pontine autosomal dominant microangiopathy with leukoencephalopathy (PADMAL) family. Sanger sequencing was used to confirm variants in all mutated probands and analyze their segregation in probands' relatives. Mutation consequences were assessed with luciferase reporter assays and real-time quantitative polymerase chain reaction (RT-qPCR). RESULTS: A candidate heterozygous variant located in a predicted miR-29 microRNA binding site, within the 3' untranslated region of COL4A1, was identified in the large French cSVD family. Five additional unrelated probands, including the PADMAL proband, harbored heterozygous variants in this microRNA binding site. Variants cosegregated with the affected phenotype, and cumulative logarithm of odds score reached 6.03, establishing linkage to this locus. A highly significant difference was observed when comparing the number of variants within this binding site in cases and controls (p = 1.77 × 10E-12). RT-qPCR analyses of patients' primary fibroblasts and luciferase reporter assays strongly favor an upregulation of COL4A1 mediated by disruption of miR-29 binding to its target site. Magnetic resonance imaging features were characterized by the presence of multiple pontine infarcts in all symptomatic mutation carriers. INTERPRETATION: Mutations upregulating COL4A1 expression lead to PADMAL, a severe early onset ischemic cSVD, distinct from the various phenotypes associated with COL4A1 missense glycine mutations. Ann Neurol 2016;80:741-753.


Asunto(s)
Enfermedades de los Pequeños Vasos Cerebrales , Colágeno Tipo IV/metabolismo , Leucoencefalopatías , MicroARNs/metabolismo , Puente/diagnóstico por imagen , Edad de Inicio , Enfermedades de los Pequeños Vasos Cerebrales/diagnóstico por imagen , Enfermedades de los Pequeños Vasos Cerebrales/genética , Enfermedades de los Pequeños Vasos Cerebrales/fisiopatología , Colágeno Tipo IV/genética , Exoma , Femenino , Francia , Ligamiento Genético , Humanos , Leucoencefalopatías/diagnóstico por imagen , Leucoencefalopatías/genética , Leucoencefalopatías/fisiopatología , Masculino , Persona de Mediana Edad , Mutación , Linaje , Unión Proteica , Regulación hacia Arriba
4.
Adv Drug Alcohol Res ; 3: 11125, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38389826

RESUMEN

Introduction: With an estimated prevalence of up to five percent in the general population, fetal alcohol spectrum disorders (FASD) are the most common neurodevelopmental disorder and more prevalent than autism. Early identification and subsequent early intervention have the potential to improve developmental trajectory of children with FASD. In addition, new research suggests supplementation with choline may ameliorate the developmental impairments associated with prenatal alcohol exposure. Availability of a screening tool with acceptable epidemiologic performance criteria may be clinical useful in identification of young children at increased risk for FASD. In this paper we describe the Early Fetal Alcohol Spectrum Disorder Screening Test (E-FAST) to identify young children at increased risk for an FASD. Methods: We developed the E-FAST dataset from previously published studies, comprised of 281 children under 5 years of age, 180 (64.1%) were diagnosed with FASD and 101 (35.9%) were non-FASD. Analysis: The analysis identified seven useful variables (prenatal alcohol exposure, ADHD (Attention Deficit Hyperactivity Disorder), foster care or adopted, small OFC (occipital frontal circumference), communication impairments, impaired social skills, and cognitive deficits. All variables were categorized as yes/no for ease of use in a screening tool. Risk ratios for each of the seven indicators were estimated using two-way table analyses. Weights for each variable were estimated based on the relative strength of their odds ratios. Results: The average age was 2.7 years of age (S.D. 1.29) and ranged from infant (6.4%) to 4 years old (35.9%). Maternal alcohol use alone had a sensitivity of 0.97, specificity 0.65, and accuracy 0.86. For the combined seven variables, sensitivity was 0.94, specificity 0.74, and accuracy 0.87. Thus, the seven-item E-FAST screen had acceptable epidemiologic screening characteristics. Discussion: In the United States, up to 547 infants with FASD are born each day which far exceeds the capacity of multidisciplinary diagnostic clinics. During routine clinical management of infants and young children the use of an evidence-based screening tool provides a time efficient means to exclude large numbers of young children from further follow-up for FASD. Conversely, a positive screen identifies a smaller number of children at increased risk for FASD requiring more intensive evaluation and follow-up.

5.
Stem Cell Reports ; 18(12): 2386-2399, 2023 12 12.
Artículo en Inglés | MEDLINE | ID: mdl-37977146

RESUMEN

Cerebral small vessel disease (SVD) affects the small vessels in the brain and is a leading cause of stroke and dementia. Emerging evidence supports a role of the extracellular matrix (ECM), at the interface between blood and brain, in the progression of SVD pathology, but this remains poorly characterized. To address ECM role in SVD, we developed a co-culture model of mural and endothelial cells using human induced pluripotent stem cells from patients with COL4A1/A2 SVD-related mutations. This model revealed that these mutations induce apoptosis, migration defects, ECM remodeling, and transcriptome changes in mural cells. Importantly, these mural cell defects exert a detrimental effect on endothelial cell tight junctions through paracrine actions. COL4A1/A2 models also express high levels of matrix metalloproteinases (MMPs), and inhibiting MMP activity partially rescues the ECM abnormalities and mural cell phenotypic changes. These data provide a basis for targeting MMP as a therapeutic opportunity in SVD.


Asunto(s)
Células Madre Pluripotentes Inducidas , Accidente Cerebrovascular , Humanos , Células Endoteliales , Encéfalo/patología , Accidente Cerebrovascular/patología , Matriz Extracelular , Metaloproteinasas de la Matriz/genética , Colágeno Tipo IV/genética
6.
Psychol Assess ; 35(11): 1000-1009, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37902668

RESUMEN

This study examined the impact of the COVID-19 pandemic on cognitive and academic functioning in 574 youth presenting for outpatient clinical neuropsychiatric evaluations. We extended the prior literature by (a) determining the extent to which academic difficulties documented in population and community samples also occurred in child psychiatric outpatients; (b) evaluating the impact of the pandemic on neuropsychological functions relevant to academic performance (overall cognition, executive functions, and graphomotor skill); and (c) investigating the moderating impact of attention deficit hyperactivity disorder (ADHD) diagnosis. We compared cross-sectional scores on standardized measures for groups of youth evaluated at three time periods related to the COVID-19 pandemic: (a) prior to onset (PRIOR; N = 198), (b) during Year 1 (Y1; N = 149), and (c) during Year 2 (Y2; N = 227). Relative to overall cognitive ability, math scores were lower in Y1 and Y2 and reading scores were lower in Y2. Additionally, relative to overall cognitive ability, youth showed lower working memory in Y1 and lower processing speed in Y1 and Y2. Graphomotor skill and parent-rated executive functions (EF) did not vary significantly across the three time periods. ADHD status did not moderate psychometric test scores but did moderate parent-rated EF. These data suggest that the COVID-19 pandemic has negatively impacted academic and executive functions in child psychiatry outpatients. More research is needed to understand the long-term implications for development. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Asunto(s)
Rendimiento Académico , COVID-19 , Adolescente , Humanos , Niño , COVID-19/epidemiología , Estudios Transversales , Pacientes Ambulatorios , Pandemias , Cognición
7.
Sci Adv ; 9(3): eadd6266, 2023 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-36652523

RESUMEN

Particulate nitrate ([Formula: see text]) has long been considered a permanent sink for NOx (NO and NO2), removing a gaseous pollutant that is central to air quality and that influences the global self-cleansing capacity of the atmosphere. Evidence is emerging that photolysis of [Formula: see text] can recycle HONO and NOx back to the gas phase with potentially important implications for tropospheric ozone and OH budgets; however, there are substantial discrepancies in "renoxification" photolysis rate constants. Using aircraft and ground-based HONO observations in the remote Atlantic troposphere, we show evidence for renoxification occurring on mixed marine aerosols with an efficiency that increases with relative humidity and decreases with the concentration of [Formula: see text], thus largely reconciling the very large discrepancies in renoxification photolysis rate constants found across multiple laboratory and field studies. Active release of HONO from aerosol has important implications for atmospheric oxidants such as OH and O3 in both polluted and clean environments.

8.
Opt Express ; 20(20): 22579-84, 2012 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-23037407

RESUMEN

A diffractive optical element is fabricated with relative ease in a glass containing spherical silver nanoparticles 30 to 40 nm in diameter and embedded in a surface layer of thickness ~10 µm. The nanocomposite was sandwiched between a mesh metallic electrode with a lattice constant 2 µm, facing the nanoparticle containing layer and acting as an anode, and a flat metal electrode as cathode. Applying moderate direct current electric potentials of 0.4 kV and 0.6 kV at an elevated temperature of 200 °C for 30 minutes across the nanocomposites led to the formation of a periodic array of embedded structures of metallic nanoparticles. The current-time dynamics of the structuring processes, optical analyses of the structured nanocomposites and diffraction pattern of one such fabricated element are presented.


Asunto(s)
Vidrio/química , Lentes , Nanopartículas del Metal/química , Refractometría/instrumentación , Plata/química , Diseño de Equipo , Análisis de Falla de Equipo
9.
Biomaterials ; 252: 120090, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32413593

RESUMEN

Basement membranes (BMs) are specialised extracellular matrices that provide structural support to tissues as well as influence cell behaviour and signalling. Mutations in COL4A1/COL4A2, a major BM component, cause a familial form of eye, kidney and cerebrovascular disease, including stroke, while common variants in these genes are a risk factor for intracerebral haemorrhage in the general population. These phenotypes are associated with matrix defects, due to mutant protein incorporation in the BM and/or its absence by endoplasmic reticulum (ER) retention. However, the effects of these mutations on matrix stiffness, the contribution of the matrix to the disease mechanism(s) and its effects on the biology of cells harbouring a collagen IV mutation remain poorly understood. To shed light on this, we employed synthetic polymer biointerfaces, poly(ethyl acrylate) (PEA) and poly(methyl acrylate) (PMA) coated with ECM proteins laminin or fibronectin (FN), to generate controlled microenvironments and investigate their effects on the cellular phenotype of primary fibroblasts harbouring a COL4A2+/G702D mutation. FN nanonetworks assembled on PEA induced increased deposition and assembly of collagen IV in COL4A2+/G702D cells, which was associated with reduced ER size and enhanced levels of protein chaperones such as BIP, suggesting increased protein folding capacity of the cell. FN nanonetworks on PEA also partially rescued the reduced stiffness of the deposited matrix and cells, and enhanced cell adhesion through increased actin-myosin contractility, effectively rescuing some of the cellular phenotypes associated with COL4A1/4A2 mutations. The mechanism by which FN nanonetworks enhanced the cell phenotype involved integrin ß1-mediated signalling. Collectively, these results suggest that biomaterials and enhanced integrin signalling via assembled FN are able to shape the matrix and cellular phenotype of the COL4A2+/G702D mutation in patient-derived cells.


Asunto(s)
Colágeno Tipo IV , Fibronectinas , Membrana Basal , Colágeno Tipo IV/genética , Matriz Extracelular , Fibroblastos , Fibronectinas/genética , Humanos , Mutación
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