Black carbon and particulate matter concentrations amid central Chile's extreme wildfires.

The increase in the frequency and severity of global wildfires has been largely influenced by climate change and land use changes. From February 2 to 6, 2024, central Chile experienced its most devastating wildland-urban interface wildfire in history, severely impacting the Valparaíso region. This catastrophic event, which led to extensive forest destruction, the loss of thousands of homes, and over a hundred human fatalities, directly impacted the area surrounding the campus of Federico Santa María Technical University. In that period, an air quality monitoring campaign was set up on the campus to measure black carbon (BC) and particulate matter (PM) during the wildfire season. The monitoring station was located directly within the smoke plume, allowing for the collection of unprecedented air quality data. Extremely high concentrations of BC at 880 nm were reported during the wildfires, with a daily mean (±σ) of 14.83 ± 19.52 µg m-3. Peak concentrations measured at 880 nm and 375 nm reached 812.89 µg m-3 and 1561.24 µg m-3, respectively. The maximum daily mean BC concentrations at these wavelengths were 55 and 99 times higher, respectively, compared to the pre-event period. The mean Ångström absorbing coefficient during the event was 1.66, indicating biomass burning as the primary BC source, while the maximum BC/PM2.5 ratio (at 375 nm) reached 57 %. From February 2 to 5, 2024, PM concentrations exceeded the Chilean air quality standard by 82 % and 198 % for coarse and fine particles, respectively. These levels are 4.7 and 6.0 times higher than the World Health Organization's recommendations. These elevated concentrations persisted for up to three days after the fire was extinguished. This study provides unique evidence of the rapid deterioration of regional air quality during a wildfire event using in situ measurements, serving as a stark reminder of the far-reaching consequences of a warming climate.

Cochlear dysfunction as an early biomarker of cognitive decline in normal hearing and mild hearing loss.

INTRODUCTION: Age-related hearing loss is an important risk factor for cognitive decline. However, audiogram thresholds are not good estimators of dementia risk in subjects with normal hearing or mild hearing loss. Here we propose to use distortion product otoacoustic emissions (DPOAEs) as an objective and sensitive tool to estimate the risk of cognitive decline in older adults with normal hearing or mild hearing loss. METHODS: We assessed neuropsychological, brain magnetic resonance imaging, and auditory analyses on 94 subjects > 64 years of age. RESULTS: We found that cochlear dysfunction, measured by DPOAEs-and not by conventional audiometry-was associated with Clinical Dementia Rating Sum of Boxes (CDR-SoB) classification and brain atrophy in the group with mild hearing loss (25 to 40 dB) and normal hearing (<25 dB). DISCUSSION: Our findings suggest that DPOAEs may be a non-invasive tool for detecting neurodegeneration and cognitive decline in the older adults, potentially allowing for early intervention.

The BrainLat project, a multimodal neuroimaging dataset of neurodegeneration from underrepresented backgrounds.

The Latin American Brain Health Institute (BrainLat) has released a unique multimodal neuroimaging dataset of 780 participants from Latin American. The dataset includes 530 patients with neurodegenerative diseases such as Alzheimer's disease (AD), behavioral variant frontotemporal dementia (bvFTD), multiple sclerosis (MS), Parkinson's disease (PD), and 250 healthy controls (HCs). This dataset (62.7 ± 9.5 years, age range 21-89 years) was collected through a multicentric effort across five Latin American countries to address the need for affordable, scalable, and available biomarkers in regions with larger inequities. The BrainLat is the first regional collection of clinical and cognitive assessments, anatomical magnetic resonance imaging (MRI), resting-state functional MRI (fMRI), diffusion-weighted MRI (DWI), and high density resting-state electroencephalography (EEG) in dementia patients. In addition, it includes demographic information about harmonized recruitment and assessment protocols. The dataset is publicly available to encourage further research and development of tools and health applications for neurodegeneration based on multimodal neuroimaging, promoting the assessment of regional variability and inclusion of underrepresented participants in research.

Estudo de incidência de acometimentos cardiovasculares e pulmonares causados pelo cigarro eletrônico: uma revisão de escopo / Incidence study of cardiovascular and pulmonary disorders caused by electronic cigarettes: a scope review

Introdução: O uso de cigarros eletrônicos (CE) tem aumentado, mas sem um estudo aprofundado sobre seus efeitos na saúde cardiovascular e pulmonar. Uma pergunta norteadora foi elaborada: Os cigarros eletrônicos causam acometimentos cardiovasculares e pulmonares? Esta revisão de escopo pontua a existência dos acometimentos cardiovasculares e pulmonares causados pelo uso de cigarros eletrônicos. Metodologia: Bancos de dados: MEDLINE-Pubmed, LILACS e Web of Science. Descritores: "Electronic Nicotine Delivery System", "E-Cigarette Vapor", "COPD", "Lung Neoplasms", "Myocardial Infarction" e "Pneumonia". Primeira busca: 28 artigos. Critérios de Exclusão: artigos que não se encaixam na classificação de estudos primários e estudos duplicados. Busca final: 6 artigos, descritos na íntegra. Resultados: Dos artigos encontrados: 83,3% (EUA); 16,7% (Coreia do Sul); 16,7% estudo transversal; 16,7% estudo longitudinal; 33,3% ensaio clínico randomizado com pessoas; 33,3% estudos de coorte. Discussão: Os artigos demonstraram que o CE pode estar associado a acometimentos cardiovasculares, como infarto e acidente vascular, apesar de não ser tão influente quando comparado ao cigarro tradicional. Quanto aos acometimentos pulmonares, não houve consenso entre os dados dos artigos pesquisados. Conclusão: Faz-se necessária a realização de mais pesquisas sobre o tema, devido a divergência entre os dados presentes na literatura.

Introduction: The use of electronic cigarettes (EC) has increased, but without an in-depth study on their effects on cardiovascular and pulmonary health. A guiding question was formulated: Do electronic cigarettes cause cardiovascular and pulmonary disorders? This scoping review points out the existence of cardiovascular and pulmonary disorders caused by the use of electronic cigarettes. Methodology: Databases: MEDLINE-Pubmed, LILACS and Web of Science. Descriptors: "Electronic Nicotine Delivery System", "E-Cigarette Vapor", "COPD", "Lung Neoplasms", "Myocardial Infarction" and "Pneumonia". First search: 28 articles. Exclusion Criteria: articles that do not fit into the classification of primary studies and duplicated studies. Final search: 6 articles, described in full. Results: Of the articles found: 83.3% (USA); 16.7% (South Korea); 16.7% cross-sectional study; 16.7% longitudinal study; 33.3% randomized clinical trial with people; 33.3% cohort studies. Discussion: The articles showed that the EC may be associated with cardiovascular disorders, such as infarction and stroke, although it is not as influential when compared to traditional cigarettes. As for pulmonary disorders, there was no consensus among the data from the researched articles. Conclusion: More research on the topic is necessary, due to the divergence between the presented data in the literature.

Understanding the role of anthropogenic emissions in glaciers retreat in the central Andes of Chile.

Glaciers in Chilean Central Andes have significatively retreated, at least, in the last 60 years. From 2004 to 2014, the largest retreat in the area (-0.15 km2 yr-1) was observed at Olivares Alpha Glacier (OAG). Previous glacier fluctuation studies proposed that two open-pit mines distant 7 km from the glacier could be the cause of its enhanced retreat. However, this had not been yet tested due to the lack of measured data. Here, we investigated the impact that major air pollutants emitted by local mining activities could have on the differences observed in OAG glacial retreat compared with a glacier of similar size and altitude with no nearby anthropogenic sources: Bello Glacier (BG), which has a reported lower retreat (-0.02 km2 yr-1). Results revealed a link between anthropogenic air pollutants and glacial retreat rates, meaning that glacial retreat is decoupled from climatic and glaciological factors. Considering that both glaciers are located in the same climatic setting, the anthropogenic air pollutants deposited onto the OAG surface appear to be forcing positive feedback in which the pollutants deposition best explain the differences in the glacier retreat. With the results of this study, it has been calculated that the impact of mining in OAG could be responsible for 82% of its total retreat since between 2004 and 2014, and only the remaining 18% would correspond to the impact of climate change.

Identification of Altered Evoked and Non-Evoked Responses in a Heterologous Mouse Model of Endometriosis-Associated Pain.

The aim of this study was to develop and refine a heterologous mouse model of endometriosis-associated pain in which non-evoked responses, more relevant to the patient experience, were evaluated. Immunodeficient female mice (N = 24) were each implanted with four endometriotic human lesions (N = 12) or control tissue fat (N = 12) on the abdominal wall using tissue glue. Evoked pain responses were measured biweekly using von Frey filaments. Non-evoked responses were recorded weekly for 8 weeks using a home cage analysis (HCA). Endpoints were distance traveled, social proximity, time spent in the center vs. outer areas of the cage, drinking, and climbing. Significant differences between groups for von Frey response, climbing, and drinking were detected on days 14, 21, and 35 post implanting surgery, respectively, and sustained for the duration of the experiment. In conclusion, a heterologous mouse model of endometriosis-associated evoked a non-evoked pain was developed to improve the relevance of preclinical models to patient experience as a platform for drug testing.

Studying Plant-Insect Interactions through the Analyses of the Diversity, Composition, and Functional Inference of Their Bacteriomes.

As with many other trophic interactions, the interchange of microorganisms between plants and their herbivorous insects is unavoidable. To test the hypothesis that the composition and diversity of the insect bacteriome are driven by the bacteriome of the plant, the bacteriomes of both the plant Datura inoxia and its specialist insect Lema daturaphila were characterised using 16S sRNA gene amplicon sequencing. Specifically, the bacteriomes associated with seeds, leaves, eggs, guts, and frass were described and compared. Then, the functions of the most abundant bacterial lineages found in the samples were inferred. Finally, the patterns of co-abundance among both bacteriomes were determined following a multilayer network approach. In accordance with our hypothesis, most genera were shared between plants and insects, but their abundances differed significantly within the samples collected. In the insect tissues, the most abundant genera were Pseudomonas (24.64%) in the eggs, Serratia (88.46%) in the gut, and Pseudomonas (36.27%) in the frass. In contrast, the most abundant ones in the plant were Serratia (40%) in seeds, Serratia (67%) in foliar endophytes, and Hymenobacter (12.85%) in foliar epiphytes. Indeed, PERMANOVA analysis showed that the composition of the bacteriomes was clustered by sample type (F = 9.36, p < 0.001). Functional inferences relevant to the interaction showed that in the plant samples, the category of Biosynthesis of secondary metabolites was significantly abundant (1.4%). In turn, the category of Xenobiotics degradation and metabolism was significantly present (2.5%) in the insect samples. Finally, the phyla Proteobacteria and Actinobacteriota showed a pattern of co-abundance in the insect but not in the plant, suggesting that the co-abundance and not the presence−absence patterns might be more important when studying ecological interactions.

Vestibular Alveolar bone height measurement: Accuracy and Correlation between direct and indirect techniques.

Cone Beam Computed Tomography (CBCT) has modified the perspective of dentistry images, providing manipulable threedimensional images with a 1:1 patient:image ratio. Treatments and diagnosis are modified or corroborated by CBCT; however, its accuracy in thin structures such as cortical bone has been subjected to critical review. The aim of this study is to correlate the measurement of vestibular alveolar bone height using direct measurements and measurements performed with cone-beam tomographic images with standard (SD) voxel resolution. Thirty incisor and premolar teeth of patients undergoing open curettage were measured with a high-precision caliper and with Cone Beam Computed Tomography (CBCT) at an SD resolution of 0.16 mm voxels in a 3D Orthophos XG Sirona scanner. Intra-observer evaluation was performed using the intraclass correlation coefficient (ICC). Direct measurements and CBCT measurements were correlated using Pearson correlation (PCC). The mean difference between indirect and direct measurements was 3.15 mm. Paired t test and Pearson Correlation coefficient determined that all measurements differed statistically from each other with p<0.05. With the CT scanner and protocol used in this study, CBCT images do not enable accurate evaluation of vestibular alveolar bone height.

La tomografía de haz cónico (CBCT) ha modificado la perspectiva de la imagenología en odontología que brinda una imagen tridimensional manipulable con una relación 1:1, paciente: imagen. Los tratamientos y diagnósticos se ven modificados o corroborados por el CBCT; sin embargo, la exactitud que presenta en estructuras delgadas como las corticales óseas ha sido sometida a críticas. El objetivo fue correlacionar la medición de la altura del hueso alveolar vestibular mediante mediciones directas y las realizadas con imágenes tomográficas de haz cónico con resolución de vóxel estándar (SD). Treinta dientes incisivos y premolares de pacientes sometidos a un curetaje abierto se midieron con un calibrador de alta precisión y una tomografía computarizada de haz cónico (CBCT) a una resolución SD de 0,16 mm de vóxeles en un escáner 3D Orthophos XG Sirona. La evaluación intraobservador se realizó utilizando el coeficiente de correlación intraclase (ICC), y las mediciones directas y las mediciones CBCT se correlacionaron utilizando la correlación de Pearson (PCC). La diferencia media entre las mediciones indirectas y directas fue de 3,15 mm. La prueba t pareada y el Coeficiente de Correlación de Pearson determinaron que todas las mediciones fueron estadísticamente diferentes entre sí con una p <0.05. Con el escáner de TC y el protocolo utilizado en este estudio, las imágenes CBCT no permiten una evaluación precisa de la altura del hueso alveolar vestibular.

Black carbon pollution in snow and its impact on albedo near the Chilean stations on the Antarctic peninsula: First results.

BC can be transported through the atmosphere from low and mid-latitudes to Antarctica, or it can be emitted in the Antarctica in situ. To establish a possible relationship between BC and the human activities in Antarctica, shallow snow samples were taken in four sites from Antarctic peninsula during summer periods (2014-2019): Chilean Base O'Higgins (BO), La Paloma Glacier (LP) (6 km away from BO); Chilean Base Yelcho (BY) and P4 (5 km away from BY). BC concentration in snow samples was determined by using a novel methodology recently developed, published and patented by the authors. The methodology consisted in a filter-based optical transmission method at a wavelength of 880 nm. Results showed that snow from BO presented the highest BC concentration (3395.7 µg kg-1), followed by BY (1309.2 µg kg-1), LP 2016 (745.9 µg kg-1), LP 2015 (233.6 µg kg-1) and finally P4 (179.4 µg kg-1). BC values observed in Antarctic snow were higher than others previously reported in the literature and showed the influence of anthropic activities in the study area, considering that the two highest values of BC concentration in snow were found at sites near the bases. To evaluate the impact of the BC concentrations found in the snow of the study area, snow albedo modeling was performed, using the on-line version of the "Snow, Ice, and Aerosol Radiative" (SNICAR) Model. Modeling outputs exposed that the measured variations in BC content caused large differences in the modeled albedo in the visible range of the spectra, which showed to be more sensitive at lower BC concentrations. These data could help to understand the role of BC in the actual scenario of climate change, in which Antarctica is presented as a very fragile environment that needs to be protected, starting with the management of the activities developed in-situ.

Vestibular Alveolar bone height measurement: Accuracy and Correlation between direct and indirect techniques / Medición de la altura del hueso alveolar vestibular: precisión y correlación entre técnicas directa e indirecta

ABSTRACT Cone Beam Computed Tomography (CBCT) has modified the perspective of dentistry images, providing manipulable threedimensional images with a 1:1 patient:image ratio. Treatments and diagnosis are modified or corroborated by CBCT; however, its accuracy in thin structures such as cortical bone has been subjected to critical review. The aim of this study is to correlate the measurement of vestibular alveolar bone height using direct measurements and measurements performed with conebeam tomographic images with standard (SD) voxel resolution. Thirty incisor and premolar teeth of patients undergoing open curettage were measured with a highprecision caliper and with Cone Beam Computed Tomography (CBCT) at an SD resolution of 0.16 mm voxels in a 3D Orthophos XG Sirona scanner. Intraobserver evaluation was performed using the intraclass correlation coefficient (ICC). Direct measurements and CBCT measurements were correlated using Pearson correlation (PCC). The mean difference between indirect and direct measurements was 3.15 mm. Paired t test and Pearson Correlation coefficient determined that all measurements differed statistically from each other with p<0.05. With the CT scanner and protocol used in this study, CBCT images do not enable accurate evaluation of vestibular alveolar bone height.

RESUMEN La tomografía de haz cónico (CBCT) ha modificado la perspectiva de la imagenología en odontología que brinda una imagen tridimensional manipulable con una relación 1:1, paciente: imagen. Los tratamientos y diagnósticos se ven modificados o corroborados por el CBCT; sin embargo, la exactitud que presenta en estructuras delgadas como las corticales óseas ha sido sometida a críticas. El objetivo fue correlacionar la medición de la altura del hueso alveolar vestibular mediante mediciones directas y las realizadas con imágenes tomográficas de haz cónico con resolución de vóxel estándar (SD). Treinta dientes incisivos y premolares de pacientes sometidos a un curetaje abierto se midieron con un calibrador de alta precisión y una tomografía computarizada de haz cónico (CBCT) a una resolución SD de 0,16 mm de vóxeles en un escáner 3D Orthophos XG Sirona. La evaluación intraobservador se realizó utilizando el coeficiente de correlación intraclase (ICC), y las mediciones directas y las mediciones CBCT se correlacionaron utilizando la correlación de Pearson (PCC). La diferencia media entre las mediciones indirectas y directas fue de 3,15 mm. La prueba t pareada y el Coeficiente de Correlación de Pearson determinaron que todas las mediciones fueron estadísticamente diferentes entre sí con una p <0.05. Con el escáner de TC y el protocolo utilizado en este estudio, las imágenes CBCT no permiten una evaluación precisa de la altura del hueso alveolar vestibular.

Framework for Structural Health Monitoring of Steel Bridges by Computer Vision.

The monitoring of a structural condition of steel bridges is an important issue. Good condition of infrastructure facilities ensures the safety and economic well-being of society. At the same time, due to the continuous development, rising wealth of the society and socio-economic integration of countries, the number of infrastructural objects is growing. Therefore, there is a need to introduce an easy-to-use and relatively low-cost method of bridge diagnostics. We can achieve these benefits by the use of Unmanned Aerial Vehicle-Based Remote Sensing and Digital Image Processing. In our study, we present a state-of-the-art framework for Structural Health Monitoring of steel bridges that involves literature review on steel bridges health monitoring, drone route planning, image acquisition, identification of visual markers that may indicate a poor condition of the structure and determining the scope of applicability. The presented framework of image processing procedure is suitable for diagnostics of steel truss riveted bridges. In our considerations, we used photographic documentation of the Fitzpatrick Bridge located in Tallassee, Alabama, USA.

Optical determination of black carbon mass concentrations in snow samples: A new analytical method.

Black carbon (BC) aerosols in the atmosphere strongly affect direct radiative forcing and climate, not only while suspended in the atmosphere but also after deposition onto high albedo surfaces. Snow surfaces are especially sensitive to BC deposition, because of their high surface albedo and additional positive feedbacks further enhance faster snowpack melting caused by BC deposition, resulting in modifications in water resources and recession of glaciers. For the analysis of BC deposition on snow, a precise quantification of BC mass is needed. Instead, optical methods have the potential of quantifying only BC, based on its characteristic spectral absorption. Commercial optical transmissometers commonly use quartz filters to filter BC and measure its optical attenuation. They are calibrated for the determination of BC mass concentrations in air, but not adapted or calibrated for their determination in water or snowmelt samples. Additionally, they are generally calibrated using BC-simulating materials that are not representative of ambient BC particles. Here, a new analytical method is demonstrated for the quantitative determination of BC mass concentration in snow samples that considers filtering of melted snow with polycarbonate filters in a new device, and optical filter attenuation BC mass concentration measurement (880 nm). The attenuation can be obtained with any optical equipment that can measure the 880-nm attenuation of filters impacted with BC/snow impurities. This method has been calibrated using real diesel vehicle exhaust soot with well-known optical properties as reference material, yielding a multipoint calibration curve for common BC concentration levels in snow. The limits of detection (0.011 mg of BC), quantification (0.036 mg of BC) and reproducibility (96.39%) of this new analytical method have been determined. Real surface snow samples collected at different locations in "Los Andes" mountains of Chile were measured with this method given a BC concentrations ranged from 151 to 5987 µg kg-1.

Temporomandibular disorders and mandibular vertical asymmetry.

Objective To analyze the association between mandibular vertical asymmetry and the presence of TMD in adult patients. Methods This case-control study recruited patients from the orthodontic clinic at FEBUAP. Patients were classified on the basis of diagnostic criteria for temporomandibular disorders (DC/TMD). Panoramic radiographs were measured to determine mandibular vertical asymmetry indices according to criteria described by Kjellberg and Habets. Both methods (DC/TMD and index criteria) were standardized a priori. Results A total of 56 patients were analyzed, of whom 25 (44.6%) met the inclusion criteria and were divided into two groups (TMD group, n = 15; non-TMD group, n = 10). The highest asymmetry index was observed in the condylar neck, followed by the total condylar asymmetry index, but without significant differences between groups (p > .05). Conclusion There is no association (p > .05) between temporomandibular disorders and mandibular vertical asymmetry.

Effects of wood moisture on emission factors for PM2.5, particle numbers and particulate-phase PAHs from Eucalyptus globulus combustion using a controlled combustion chamber for emissions.

Polycyclic aromatic hydrocarbons, PM2.5 and micrometer-sized particles are mainly emitted by residential wood combustion, affecting air pollution in the cities of Chile. Eucalyptus globulus (EG) at 0% and 25% wood moisture was burning using a new controlled combustion chamber for emissions (3CE) to determine the emission factors of PM2.5, micrometer-sized particle numbers (0.265µm to 34.00µm) and 16 EPA-PAHs plus retene adsorbed on PM2.5 quartz filters. A method using accelerated solvent extraction, concentration, clean-up and GC-MS is proposed for determining emission factors for 16 EPA-PAHs for the concentration from biomass combustion. Chromatographic conditions and analytical steps were optimized in terms of linearity, selectivity, limits of detection and quantification, precision and accuracy. The recovery obtained from urban dust SRM 1649A (NIST reference material) analyses was between 63% (benzo[b]fluoranthene) and 102% (benzo[k]fluoranthene). In this investigation, it was shown that increasing the wood moisture in combustion tests decreased combustion efficiency (93% to 49%) and increased the emission factors of total PAHs (5215.47ngg-1 to 7644.48ngg-1), the gravimetric PM2.5 (2.01g kg-1 to 22.90gkg-1) and the total number of measured micrometer-sized particles (3.15×1012 particles kg-1 to 1.33×1013 particles kg-1) due to incomplete combustion. The PM2.5 emission rates (ERs) were estimated using EG at 0% WM (2.39g-1 to 3.15gh-1) and 25% WM (27.32gh-1 to 35.77gh-1) for three regions of Chile. In almost all regions, the Chilean emission regulations were exceeded for PM2.5 from wood combustion in the heater (stove with thermal power ≤8kW and emission limit of 2.5gh-1). Finally, when using wet wood for residential combustion, the amount of PAHs on the PM2.5 increased, presenting a potential hazard to population health. Therefore, improvements are necessary in the current regulation of PM emissions.

A study of allelic diversity underlying flowering-time adaptation in maize landraces.

Landraces (traditional varieties) of domesticated species preserve useful genetic variation, yet they remain untapped due to the genetic linkage between the few useful alleles and hundreds of undesirable alleles. We integrated two approaches to characterize the diversity of 4,471 maize landraces. First, we mapped genomic regions controlling latitudinal and altitudinal adaptation and identified 1,498 genes. Second, we used F-one association mapping (FOAM) to map the genes that control flowering time, across 22 environments, and identified 1,005 genes. In total, we found that 61.4% of the single-nucleotide polymorphisms (SNPs) associated with altitude were also associated with flowering time. More than half of the SNPs associated with altitude were within large structural variants (inversions, centromeres and pericentromeric regions). The combined mapping results indicate that although floral regulatory network genes contribute substantially to field variation, over 90% of the contributing genes probably have indirect effects. Our dual strategy can be used to harness the landrace diversity of plants and animals.

Emission factors for PM2.5, CO, CO2, NOx, SO2 and particle size distributions from the combustion of wood species using a new controlled combustion chamber 3CE.

The objective of this research was to determine emission factors (EF) for particulate matter (PM2.5), combustion gases and particle size distribution generated by the combustion of Eucalyptus globulus (EG), Nothofagus obliqua (NO), both hardwoods, and Pinus radiata (PR), softwood, using a controlled combustion chamber (3CE). Additionally, the contribution of the different emissions stages associated with the combustion of these wood samples was also determined. Combustion experiments were performed using shaving size dried wood (0% humidity). The emission samples were collected with a tedlar bag and sampling cartridges containing quartz fiber filters. High reproducibility was achieved between experiment repetitions (CV<10%, n=3). The EF for PM2.5 was 1.06gkg-1 for EG, 1.33gkg-1 for NO, and 0.84gkg-1 for PR. Using a laser aerosol spectrometer (0.25-34µm), the contribution of particle emissions (PM2.5) in each stage of emission process (SEP) was sampled in real time. Particle size of 0.265µm were predominant during all stages, and the percentages emitted were PR (33%), EG (29%), and NO (21%). The distributions of EF for PM2.5 in pre-ignition, flame and smoldering stage varied from predominance of the flame stage for PR (77%) to predominance of the smoldering stage for NO (60%). These results prove that flame phase is not the only stage contributing to emissions and on the contrary, pre-ignition and in especial post-combustion smoldering have also very significant contributions. This demonstrates that particle concentrations measured only in stationary state during flame stage may cause underestimation of emissions.

Scavenging of black carbon in Chilean coastal fogs.

In November/December 2013 a pilot experiment on aerosol/fog interaction was conducted on a coastal hill in the suburbs of Valparaíso, Chile. Passages of garúa fog were monitored with continuous recordings of a soot photometer and an optical aerosol spectrometer. An optical fog sensor and an automatic weather station provided meteorological data with which the aerosol could be classified. High-resolution back trajectories added meteorological information. From filter samples, optical and chemical aerosol information was derived. Scavenging coefficients of black carbon (BC) and measured particulate mass below 1 µm diameter (PM1) were estimated with three approaches. Averaging over all fog periods of the campaign yielded a scavenging coefficient of only 6% for BC and 40% for PM1. Dividing the data into four 90°-wind sectors gave scavenging factors for BC ranging from 13% over the Valparaíso, Viña del Mar conurbation to 50% in the marine sector (180°-270°). The third, and independent approach was achieved with two pairs of chemical aerosol samples taken inside and outside fogs, which yielded a scavenging coefficient of 25% for BC and 70% for nonseasalt sulfate. Whereas fogs occurred rather infrequently in the beginning of the campaign highly regular daily fog cycles appeared towards the end of the experiment, which allowed the calculation of typical diurnal cycles of the aerosol in relation to a fog passage.

Paralisia periódica hipocalêmica tireotóxica: relato de caso / Thyrotoxic hypokalemic periodic paralysis: a case report

Relata-se neste artigo o caso de um paciente de ascendência negra com quadro agudo e progressivo de paralisia flácida ascendente, sem comprometimento de musculatura respiratória ou facial, em vigência de hipertireoidismo em tratamento e hipocalemia desencadeados por quadro infeccioso. Foi realizado o diagnóstico de paralisia periódica hipocalêmica tireotóxica e controle inicial dos sintomas por adequação sérica do potássio e posterior resolução do quadro após tratamento com iodoterapia.

It is reported in this paper the case of a black ancestry patient with acute and progressive framework ascending flaccid paralysis without impairment of respiratory and facial muscles, in effect in treatment of hyperthyroidism and hypokalemia triggered by infection. The diagnosis of thyrotoxic hypokalemic periodic paralysis was accomplished and initial symptoms were controlled for adequacy of serum potassium and subsequent resolution after treatment with radioiodine.