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BACKGROUND: Dementia, with Alzheimer's disease (AD) being the most common type of this neurodegenerative disease, is an under-diagnosed health problem in older people. The creation of classification models based on AD risk factors using Deep Learning is a promising tool to minimize the impact of under-diagnosis. OBJECTIVE: To develop a Deep Learning model that uses clinical data from patients with dementia to classify whether they have AD. METHODS: A Deep Learning model to identify AD in clinical records is proposed. In addition, several rebalancing methods have been used to preprocess the dataset and several studies have been carried out to tune up the model. RESULTS: Model has been tested against other well-established machine learning techniques, having better results than these in terms of AUC with alpha less than 0.05. CONCLUSIONS: The developed Neural Network Model has a good performance and can be an accurate assisting tool for AD diagnosis.
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Enfermedad de Alzheimer , Aprendizaje Profundo , Enfermedades Neurodegenerativas , Humanos , Anciano , Imagen por Resonancia Magnética/métodos , Neuroimagen/métodosRESUMEN
Motivational development with regards to sport plays a fundamental role in sport performance, however, anxiety and dietary patterns also play a key role. In consideration of the above, the present research aimed to develop an explanatory model of the motivational climate towards sport and its relationship with the Mediterranean diet and anxiety. This structural model was then examined according to gender using multi-group analysis. To this end, a cross-sectional, descriptive and comparative study was carried out with 556 university students. The instruments used were a sociodemographic questionnaire, the Perceived Motivational Climate in Sport Questionnaire (PMCSQ-2), the Beck Anxiety Inventory (BAI) and the Predimed questionnaire. Finally, outcomes revealed that the female gender had a negative relationship with adherence to a healthy dietary pattern, whilst males showed better adherence to the Mediterranean diet and higher levels of anxiety (AU)
La motivación juega un papel fundamental en la práctica del ejercicio físico, sin embargo, la ansiedad y el patrón dietético también juegan un rol clave, por tanto,la presente investigación refleja los objetivos de desarrollar un modelo explicativo del clima motivacional hacia el deporte y su relación con la dieta mediterránea y la ansiedad y contrastar el modelo estructural mediante un análisis multigrupo en función del sexo. Se ha realizado un estudio descriptivo comparativo de corte transversal con 556 estudiantes universitarios. Los instrumentos utilizados han sido un cuestionario sociodemográfico, el Cuestionario de Clima Motivacional Percibido en el Deporte (PMCSQ-2), el Inventario de Ansiedad de Beck (BAI) y el cuestionario Predimed. Finalmente, los resultados revelan que el sexo femenino tiene una relación negativa con la adherencia positiva a un patrón dietético saludable, mientras que el masculino muestra una mejor adherencia hacia la dieta mediterránea y mayores niveles de ansiedad (AU)
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Humanos , Motivación , Deportes , Ansiedad/psicología , Dieta MediterráneaRESUMEN
Motivation is one of the most studied elements in sport psychology due to its great potential to explain the attitude towards sport practice. Therefore, the present systematic review aims to analyse the effects of sport-oriented motivation on physical activity, anxiety and self-concept. The Web of Science and SCOPUS databases were used to select articles published between 2012 and 2022. The criteria established by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement were followed for the elaboration of the systematic review, with the final analysis sample comprising a total of 19 articles. Finally, the analysis of the data reveals that developing sport motivation from extrinsic or intrinsic values can help to decrease or increase anxiety levels. In addition, it is also observed that motivation developed through extrinsic values plays a key role in the abandonment of physical activity, due to the frustration and worsening of the mental image generated at a professional level when the proposed objectives are not achieved.(AU)
Actualmente, la motivación es uno de los elementos más estudiados en la psicología del deporte debido a su gran potencial para explicar la actitud hacia la práctica deportiva. Es por ello que la presente revisión sistemática presenta el objetivo de analizar los efectos de la motivación orientada hacia el deporte sobre la práctica de actividad física, la ansiedad y el autoconcepto. Para ello se han utilizado las bases de datos de Web of Science y SCOPUS eligiéndose los artículos publicados entre los años 2012 y 2022. Para la elaboración de la revisión sistemática se han seguido los criterios establecidos por la declaración de los Elementos de Información Preferidos para Revisiones Sistemáticas y Meta-Análisis (PRISMA), quedando la muestra final de análisis compuesta por un total de 19 artículos. Finalmente, el análisis de los datos revela que desarrollar una motivación deportiva desde valores extrínsecos o intrínsecos puede ayudar a disminuir o a aumentar los niveles de ansiedad. Además, también se observa como la motivación desarrollada a través de valores extrínsecos supone jugar un papel clave en el abandono de la práctica de actividad físico deportiva, debido a la frustración y empeoramiento de la imagen mental generada a nivel profesional cuando no se consiguen los objetivos propuestos.(AU)
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Humanos , Ansiedad , Autoimagen , Actividad Motora , Motivación , Psicología del DeporteRESUMEN
Pyrocumulonimbus (pyroCb) are wildfire-generated convective clouds that can inject smoke directly into the stratosphere. PyroCb have been tracked for years, yet their apparent rarity and episodic nature lead to highly uncertain climate impacts. In situ measurements of pyroCb smoke reveal its distinctive and exceptionally stable aerosol properties and define the long-term influence of pyroCb activity on the stratospheric aerosol budget. Analysis of 13 years of airborne observations shows that pyroCb are responsible for 10 to 25% of the black carbon and organic aerosols in the "present-day" lower stratosphere, with similar impacts in both the North and South Hemispheres. These results suggest that, should pyroCb increase in frequency and/or magnitude in future climates, they could generate dominant trends in stratospheric aerosol.
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Some infectious diseases, including COVID-19, can undergo airborne transmission. This may happen at close proximity, but as time indoors increases, infections can occur in shared room air despite distancing. We propose two indicators of infection risk for this situation, that is, relative risk parameter (Hr) and risk parameter (H). They combine the key factors that control airborne disease transmission indoors: virus-containing aerosol generation rate, breathing flow rate, masking and its quality, ventilation and aerosol-removal rates, number of occupants, and duration of exposure. COVID-19 outbreaks show a clear trend that is consistent with airborne infection and enable recommendations to minimize transmission risk. Transmission in typical prepandemic indoor spaces is highly sensitive to mitigation efforts. Previous outbreaks of measles, influenza, and tuberculosis were also assessed. Measles outbreaks occur at much lower risk parameter values than COVID-19, while tuberculosis outbreaks are observed at higher risk parameter values. Because both diseases are accepted as airborne, the fact that COVID-19 is less contagious than measles does not rule out airborne transmission. It is important that future outbreak reports include information on masking, ventilation and aerosol-removal rates, number of occupants, and duration of exposure, to investigate airborne transmission.
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Contaminación del Aire Interior , COVID-19 , Aerosoles , Brotes de Enfermedades , Humanos , SARS-CoV-2 , VentilaciónRESUMEN
The COVID-19 pandemic has exposed major gaps in our understanding of the transmission of viruses through the air. These gaps slowed recognition of airborne transmission of the disease, contributed to muddled public health policies and impeded clear messaging on how best to slow transmission of COVID-19. In particular, current recommendations have been based on four tenets: (i) respiratory disease transmission routes can be viewed mostly in a binary manner of 'droplets' versus 'aerosols'; (ii) this dichotomy depends on droplet size alone; (iii) the cut-off size between these routes of transmission is 5 µm; and (iv) there is a dichotomy in the distance at which transmission by each route is relevant. Yet, a relationship between these assertions is not supported by current scientific knowledge. Here, we revisit the historical foundation of these notions, and how they became entangled from the 1800s to today, with a complex interplay among various fields of science and medicine. This journey into the past highlights potential solutions for better collaboration and integration of scientific results into practice for building a more resilient society with more sound, far-sighted and effective public health policies.
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La adolescencia es una etapa de desarrollo, la cual juega un papel clave en lo que se refiere a la adquisición de una adherencia positiva a un patrón dietético saludable y en el control de las distintas emociones vivenciadas en el día a día. Teniendo en cuenta lo anterior, la presente investigación refleja los objetivos de desarrollar un modelo explicativo de la incidencia de la atención, claridad y reparación emocional sobre la adherencia hacia la dieta mediterránea en estudiantes del tercer ciclo de educación primaria y contrastar el modelo estructural mediante un análisis multigrupo en función del sexo. Para ello, se ha realizado un estudio descriptivo comparativo de corte transversal con 293 estudiantes del tercer ciclo de educación primaria. Los instrumentos utilizados han sido un cuestionario sociodemográfico, el test KIDMED y el Trait Meta-Mood Scale (TMMS-24). Finalmente, los resultados revelan una relación negativa entre la adherencia a la dieta mediterránea y la claridad y atención emocional en el sexo femenino.(AU)
Adolescence is a stage of development, which plays a key role in terms of acquiring positive adherence to a healthy dietary pattern and in controlling the different emotions experienced on a daily basis. Taking into account the above, the present investigation reflects the objectives of developing an explanatory model of the incidence of attention, clarity and emotional repair on adherence to the Mediterranean diet in students of the third cycle of primary education and contrasting the structural model through a multigroup analysis according to sex. For this, a cross-sectional comparative descriptive study has been carried out with 293 students of the third cycle of primary education. The instruments used have been a sociodemographic questionnaire, the KIDMED test and the Trait Meta-Mood Scale (TMMS-24). Finally, the results reveal a negative relationship between adherence to the Mediterranean diet and clarity and emotional attention in the female sex.(AU)
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Humanos , Adolescente , Dieta Mediterránea , Inteligencia Emocional , Educación Primaria y Secundaria , Dieta Saludable , España , Encuestas y Cuestionarios , Estudios TransversalesRESUMEN
BACKGROUND: The appearance of resistance against new treatments and the fact that HIV-1 can infect various cell types and develop reservoirs and sanctuaries makes it necessary to develop new therapeutic approaches to overcome those failures. RESULTS: Studies of cytotoxicity, genotoxicity, complexes formation, stability, resistance, release and particle size distribution confirmed that G2-SN15-PEG, G3-SN31-PEG, G2-SN15-PEG-FITC and G3-SN31-PEG-FITC dendrimers can form complexes with miRNAs being biocompatible, stable and conferring protection to these nucleic acids. Confocal microscopy and flow cytometry showed effective delivery of these four dendrimers into the target cells, confirming their applicability as delivery systems. Dendriplexes formed with the dendrimers and miRNAs significantly inhibited HIV-1 infection in PBMCs. CONCLUSIONS: These dendrimers are efficient delivery systems for miRNAs and they specifically and significantly improved the anti-R5-HIV-1 activity of these RNA molecules.
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Cationes/farmacología , Dendrímeros/farmacología , Infecciones por VIH/tratamiento farmacológico , MicroARNs/farmacología , Polietilenglicoles/farmacología , Línea Celular , Sistemas de Liberación de Medicamentos , VIH-1/efectos de los fármacos , Humanos , Leucocitos Mononucleares , Ácidos Nucleicos , Tamaño de la PartículaRESUMEN
BACKGROUND: Human cytomegalovirus (HCMV) is a worldwide infection, causing different troublesome in immunosupressed patients and very related to Human Immunodeficiency Virus 1 (HIV-1) infection, mainly in developing countries, with a co-infection rate of 80% in Africa. The high cost of present treatments and the lack of routinely tests in these countries urge the necessity to develop new molecules or strategies against HCMV. The new treatments should be low-cost and capable of avoiding the emerging problem of resistant virus. Nanoparticles play an important role in several viral infections. Our main focus is to study the potential activity of polyanionic carbosilane dendrimers (PDC), which are hyperbranched molecules with several sulfonate or sulfate groups in their periphery, against different viruses. RESULTS: We studied the activity of G1-S4, G2-S16 and G2-S24P PDCs in MRC-5 cell line against HCMV infection by several plaque reduction assays. Our results show that dendrimers present good biocompatibility at the concentrations tested (1-50 µM) for 6 days in cell culture. Interestingly, both G2-S16 and G2-S24P showed a remarked inhibition at 10 µM against HCMV infection. Results on attachment and virucidal assays indicated that the inhibition was not directed to the virus or the virus-cell attachment. However, results of time of addition, showed a longer lasting activity of these dendrimers in comparison to ganciclovir, and the combination of G2-S16 or G2-S24P with ganciclovir increases the HCMV inhibition around 90 %. CONCLUSIONS: Nanotechnology, in particular polyanionic carbosilane dendrimers, have proved their potential application against HCMV, being capable of inhibiting the infection by themselves or enhancing the activity of ganciclovir, the actual treatment. These compounds represent a low-cost approach to fight HCMV infections.
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Antivirales/farmacología , Infecciones por Citomegalovirus/tratamiento farmacológico , Citomegalovirus/efectos de los fármacos , Dendrímeros/farmacología , Nanotecnología/métodos , Silanos/farmacología , Fármacos Anti-VIH/farmacología , Línea Celular , Fibroblastos , Ganciclovir , Infecciones por VIH , VIH-1 , Humanos , PolielectrolitosRESUMEN
The coronavirus disease 2019 (COVID-19) pandemic has caused untold disruption throughout the world. Understanding the mechanisms for transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is key to preventing further spread, but there is confusion over the meaning of 'airborne' whenever transmission is discussed. Scientific ambivalence originates from evidence published many years ago which has generated mythological beliefs that obscure current thinking. This article collates and explores some of the most commonly held dogmas on airborne transmission in order to stimulate revision of the science in the light of current evidence. Six 'myths' are presented, explained and ultimately refuted on the basis of recently published papers and expert opinion from previous work related to similar viruses. There is little doubt that SARS-CoV-2 is transmitted via a range of airborne particle sizes subject to all the usual ventilation parameters and human behaviour. Experts from specialties encompassing aerosol studies, ventilation, engineering, physics, virology and clinical medicine have joined together to produce this review to consolidate the evidence for airborne transmission mechanisms, and offer justification for modern strategies for prevention and control of COVID-19 in health care and the community.
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Aerosoles , Microbiología del Aire , COVID-19/prevención & control , COVID-19/transmisión , Control de Infecciones/métodos , Pandemias/prevención & control , Ventilación/métodos , Adulto , Anciano , Anciano de 80 o más Años , COVID-19/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , SARS-CoV-2RESUMEN
Accurate fire emissions inventories are crucial to predict the impacts of wildland fires on air quality and atmospheric composition. Two traditional approaches are widely used to calculate fire emissions: a satellite-based top-down approach and a fuels-based bottom-up approach. However, these methods often considerably disagree on the amount of particulate mass emitted from fires. Previously available observational datasets tended to be sparse, and lacked the statistics needed to resolve these methodological discrepancies. Here, we leverage the extensive and comprehensive airborne in situ and remote sensing measurements of smoke plumes from the recent Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) campaign to statistically assess the skill of the two traditional approaches. We use detailed campaign observations to calculate and compare emission rates at an exceptionally high-resolution using three separate approaches: top-down, bottom-up, and a novel approach based entirely on integrated airborne in situ measurements. We then compute the daily average of these high-resolution estimates and compare with estimates from lower resolution, global top-down and bottom-up inventories. We uncover strong, linear relationships between all of the high-resolution emission rate estimates in aggregate, however no single approach is capable of capturing the emission characteristics of every fire. Global inventory emission rate estimates exhibited weaker correlations with the high-resolution approaches and displayed evidence of systematic bias. The disparity between the low-resolution global inventories and the high-resolution approaches is likely caused by high levels of uncertainty in essential variables used in bottom-up inventories and imperfect assumptions in top-down inventories.
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The House Observations of Microbial and Environmental Chemistry (HOMEChem) study is a collaborative field investigation designed to probe how everyday activities influence the emissions, chemical transformations and removal of trace gases and particles in indoor air. Sequential and layered experiments in a research house included cooking, cleaning, variable occupancy, and window-opening. This paper describes the overall design of HOMEChem and presents preliminary case studies investigating the concentrations of reactive trace gases, aerosol particles, and surface films. Cooking was a large source of VOCs, CO2, NOx, and particles. By number, cooking particles were predominantly in the ultrafine mode. Organic aerosol dominated the submicron mass, and, while variable between meals and throughout the cooking process, was dominated by components of hydrocarbon character and low oxygen content, similar to cooking oil. Air exchange in the house ensured that cooking particles were present for only short periods. During unoccupied background intervals, particle concentrations were lower indoors than outdoors. The cooling coils of the house ventilation system induced cyclic changes in water soluble gases. Even during unoccupied periods, concentrations of many organic trace gases were higher indoors than outdoors, consistent with housing materials being potential sources of these compounds to the outdoor environment. Organic material accumulated on indoor surfaces, and exhibited chemical signatures similar to indoor organic aerosol.
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Microbiología del Aire/normas , Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/análisis , Monitoreo del Ambiente/métodos , Vivienda/normas , Material Particulado/análisis , Aerosoles , Aire Acondicionado , Filtros de Aire , Culinaria , Gases , Humanos , Tamaño de la PartículaRESUMEN
Organic soils have low sorption capacities for phosphorus (P), and may pose a risk of P loss to water if P applications to these soils coincide with runoff events. Little is known about the magnitude of exports of P in overland flow following application of P fertiliser onto these soils, or on the influence of the frequency on P losses and persistence. The number of P fertiliser applications was surveyed across 39 commercial farms to assess current practice and inform the design of a rainfall runoff experiment to evaluate the effect of frequency of P applications on losses and persistence across time. Superphosphate (16% P) was applied in single (equivalent to 30 and 55â¯kgâ¯P ha-1 applied at day 0) and split (equivalent to 15 and 27.5â¯kgâ¯P ha-1 applied in two doses at days 0 and 55) applications to an organic soil inclined at a slope of 6% in a rainfall simulator experiment. The surface runoff of dissolved reactive phosphorus (DRP) was measured in controlled 30-min rainfall simulations conducted intermittently over an 85-day period. The DRP losses in surface runoff after the first rainfall event were 44.6 and 97.8â¯mgâ¯L-1 for single applications of 30 and 55â¯kgâ¯ha-1, respectively, and 13.3 and 21.8â¯mgâ¯L-1 for the same rates split in two doses, indicating that single P applications had disproportionately bigger impacts on losses than split applications. This supports the idea that frequent, but smaller, P applications can minimise the impact of fertilisation on waters. Dissolved reactive P concentrations remained significantly higher than those from the control samples until the end the experiment for almost all the P treatments, highlighting the long-lasting effects of added P and the elevated risk of P losses on organic soils. For climates with frequent rainfall events, which are likely to coincide with fertiliser applications, smaller but more frequent P applications can reduce the risk of P transfer as opposed to one single application.
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Fertilizantes , Fósforo , Estiércol , Lluvia , Suelo , Movimientos del AguaRESUMEN
During winter in the mid-latitudes, photochemical oxidation is significantly slower than in summer and the main radical oxidants driving formation of secondary pollutants, such as fine particulate matter and ozone, remain uncertain, owing to a lack of observations in this season. Using airborne observations, we quantify the contribution of various oxidants on a regional basis during winter, enabling improved chemical descriptions of wintertime air pollution transformations. We show that 25-60% of NOx is converted to N2O5 via multiphase reactions between gas-phase nitrogen oxide reservoirs and aerosol particles, with ~93% reacting in the marine boundary layer to form >2.5 ppbv ClNO2. This results in >70% of the oxidizing capacity of polluted air during winter being controlled, not by typical photochemical reactions, but from these multiphase reactions and emissions of volatile organic compounds, such as HCHO, highlighting the control local anthropogenic emissions have on the oxidizing capacity of the polluted wintertime atmosphere.
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BACKGROUND: Preterm infants usually have to spend a long time in an incubator, excessive noise in which can have adverse physiological and psychological effects on neonates. In fact, incubator noise levels typically range from 45 to 70â¯dB but differences in this respect depend largely on the noise measuring method used. The primary aim of this work was to assess the extent to which noise in an incubator comes from its own fan and how efficiently the incubator can isolate external noise. METHODS: Three different incubator models were characterized for acoustic performance by measuring their internal noise levels in an anechoic chamber, and also for noise isolation efficiency by using a pink noise source in combination with an internal and an external microphone that were connected to an SVAN958 noise analyzer. RESULTS: The incubators studied produced continuous equivalent noise levels of 53.5-58â¯dB and reduced external noise by 5.2-10.4â¯dB. CONCLUSIONS: A preterm infant in an incubator is exposed to noise levels clearly exceeding international recommendations even though such levels usually comply with the limit set in the standard IEC60601-2-19: 2009 (60â¯dBA) under normal conditions of use.
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Diseño de Equipo/efectos adversos , Incubadoras para Lactantes/estadística & datos numéricos , Ruido/efectos adversos , Acústica , Diseño de Equipo/estadística & datos numéricos , Humanos , Recién Nacido , Recien Nacido Prematuro , Enfermedades del PrematuroRESUMEN
BACKGROUND: NRTIs-sparing regimens exert favourable profiles on T-cell homeostasis associated parameters. Our aim was to analyze the effect of NRTIs sparing regimen (NRTI-sparing-cART) vs NRTIs-containing regimen (NRTI-cART), on T-cell homeostasis associated parameters in naive HIV-infected patients. METHODS: Biomarkers of cell survival (CD127) and replicative senescence (CD57), were measured by multiparametric flow cytometry for T-cell phenotyping on peripheral blood mononuclear cells (PBMCs) samples just before (baseline) and after 48 weeks of undetectable viral load in patients on NRTI-sparing-cART (N = 13) and NRTI-cART (N = 14). After 48 weeks a subgroup of patients (n = 5) on NRTI-cART switched to NRTI-sparing-cART for another additional 48 weeks. In vitro assays were performed on PBMCs from HIV-uninfected healthy donors exposed or not to HIV. To analyze the independent factors associated with type of cART bivariate and stepwise multivariate analysis were performed after adjusting for basal CD4+, CD8+ and nadir CD4+ T-cell counts. RESULTS: After 48 weeks of a NRTI-sparing-cART vs NRTI-cART patients have higher effector memory (EM) CD4+ CD127+ T-cell levels, lower EM CD4+ CD57+ T-cell levels, higher CD8+ CD127+ T-cell levels, lower CD8+ CD57+ T-cell levels and higher memory CD8+ T-cell levels. This effect was confirmed in the subgroup of patients who switched to NRTI-sparing-cART. In vitro assays confirmed that the deleterious effect of a NRTIs-containing regimen was due to NRTIs. CONCLUSIONS: The implementation of NRTI-sparing regimens, with a favourable profile in CD127 and CD57 T-cell expression, could benefit cART-patients. These results could have potential implications in a decrease in the number of Non-AIDS events.
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Antígenos CD57/metabolismo , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/inmunología , Subunidad alfa del Receptor de Interleucina-7/metabolismo , Inhibidores de la Transcriptasa Inversa/uso terapéutico , Linfocitos T/metabolismo , Adulto , Quimioterapia Combinada , Femenino , Homeostasis , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus type 1 (HIV-1) represent the two most frequent sexually transmitted infections (STI) worldwide. Epidemiological studies suggest that HSV-2 increases the risk of HIV-1 acquisition approximately 3-fold mainly due to the clinical and immunological manifestations. In the absence of vaccines against both STI, the development of new preventive strategies has become essential for further studies. We performed the screening of six novel polyanionic carbosilane dendrons to elucidate their potential activity against HSV-2/HIV-1 co-infection and their mechanism of action. These new nanoparticles are carbosilane branched dendrons from first to third generation, with palmitic or hexanoic fatty acids as the core and capped with sulfonate groups, named G1d-STE2Hx, G2d-STE4Hx, G3d-STE8Hx, G1d-STE2Pm, G2d-STE4Pm and G3d-STE8Pm. G3d-STE8Hx and G3d-STE8Pm carbosilane branched dendrons showed high viability. These dendrons also showed a great broad-spectrum antiviral activity, as well as a suitable efficacy against HIV-1 even if the mucosal disruption occurs as a consequence of HSV-2 infection. Our results exert high inhibition against HSV-2 and HIV-1 by blocking the entry of both viruses with the median effective concentration EC50 values in the nanomolar range. Additionally, G3d-STE8Hx and G3d-STE8Pm retained their anti-HSV-2/HIV-1 activity at different pH values. G3d-STE8Hx and G3d-STE8Pm dendrons may be potential candidates as dual-acting microbicides against HSV-2/HIV-1 co-infection.
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Antivirales/farmacología , Dendrímeros/química , Ácidos Grasos/química , VIH-1/efectos de los fármacos , Herpesvirus Humano 2/efectos de los fármacos , Silanos/farmacología , Animales , Chlorocebus aethiops , Coinfección/tratamiento farmacológico , Coinfección/virología , Infecciones por VIH/tratamiento farmacológico , Herpes Genital/tratamiento farmacológico , Humanos , Plantas Medicinales , Células VeroRESUMEN
A large fraction of atmospheric organic aerosol (OA) originates from natural emissions that are oxidized in the atmosphere to form secondary organic aerosol (SOA). Isoprene (IP) and monoterpenes (MT) are the most important precursors of SOA originating from forests. The climate impacts from OA are currently estimated through parameterizations of water uptake that drastically simplify the complexity of OA. We combine laboratory experiments, thermodynamic modeling, field observations, and climate modeling to (1) explain the molecular mechanisms behind RH-dependent SOA water-uptake with solubility and phase separation; (2) show that laboratory data on IP- and MT-SOA hygroscopicity are representative of ambient data with corresponding OA source profiles; and (3) demonstrate the sensitivity of the modeled aerosol climate effect to assumed OA water affinity. We conclude that the commonly used single-parameter hygroscopicity framework can introduce significant error when quantifying the climate effects of organic aerosol. The results highlight the need for better constraints on the overall global OA mass loadings and its molecular composition, including currently underexplored anthropogenic and marine OA sources.
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Carbonaceous particulate matter (PM), comprising black carbon (BC), primary organic aerosol (POA) and secondary organic aerosol (SOA, from atmospheric aging of precursors), is a highly toxic vehicle exhaust component. Therefore, understanding vehicle pollution requires knowledge of both primary emissions, and how these emissions age in the atmosphere. We provide a systematic examination of carbonaceous PM emissions and parameterisation of SOA formation from modern diesel and gasoline cars at different temperatures (22, -7 °C) during controlled laboratory experiments. Carbonaceous PM emission and SOA formation is markedly higher from gasoline than diesel particle filter (DPF) and catalyst-equipped diesel cars, more so at -7 °C, contrasting with nitrogen oxides (NOX). Higher SOA formation from gasoline cars and primary emission reductions for diesels implies gasoline cars will increasingly dominate vehicular total carbonaceous PM, though older non-DPF-equipped diesels will continue to dominate the primary fraction for some time. Supported by state-of-the-art source apportionment of ambient fossil fuel derived PM, our results show that whether gasoline or diesel cars are more polluting depends on the pollutant in question, i.e. that diesel cars are not necessarily worse polluters than gasoline cars.