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1.
Sci Total Environ ; 932: 173005, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38723966

RESUMO

Road traffic is the primary source of environmental noise pollution in cities. This problem is also spreading due to inadequate urban expansion planning. Hence, integrating road traffic noise analysis into urban planning is necessary for reducing city noise in an effective, adaptable, and sustainable way. This study aims to develop a methodology that applies to any city for the stratification of urban roads by their functionality through only their urban features. It is intended to be a tool to cluster similar streets and, consequently, traffic noise to enable urban and transportation planners to support the reduction of people's noise exposure. Three multivariate ordered logistic regression statistical models (Model 1, 2, and 3) are presented that significantly stratify urban roads into five, four, and three categories, respectively. The developed models exhibit a McFadden pseudo-R2 between 0.5 and 0.6 (equivalent to R2 >0.8). The choice between Model 1 or 2 depends on the scale of the city. Model 1 is recommended for developed cities with an extensive road network, while Model 2 is most suitable in intermediate and growing cities. On the other hand, Model 3 could be applied at any city scale but focused on local management of transit routes and for designing acoustic sensor installations, urban soundwalks, and identification of quiet areas. Urban features related to road width and length, presence of transport infrastructure, and public transport routes are associated with increased traffic noise in all three models. These models prove useful for future action plans aimed at reducing noise through strategic urban planning.

2.
Environ Geochem Health ; 46(3): 87, 2024 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-38367090

RESUMO

The ecotoxic effect of Zn species arising from the weathering of the marmatite-like sphalerite ((Fe, Zn)S) in Allium cepa systems was herein evaluated in calcareous soils and connected with its sulfide oxidation mechanism to determine the chemical speciation responsible of this outcome. Mineralogical analyses (X-ray diffraction patterns, Raman spectroscopy, scanning electron microscopy and atomic force microscopy), chemical study of leachates (total Fe, Zn, Cd, oxidation-reduction potential, pH, sulfates and total alkalinity) and electrochemical assessments (chronoamperometry, chronopotentiometry, cyclic voltammetry, and electrochemical impedance spectroscopy) were carried out using (Fe, Zn)S samples to elucidate interfacial mechanisms simulating calcareous soil conditions. Results indicate the formation of polysulfides (Sn2-), elemental sulfur (S0), siderite (FeCO3)-like, hematite (Fe2O3)-like with sorbed CO32- species, gunningite (ZnSO4·H2O)-like phase and smithsonite (ZnCO3)-like compounds in altered surface under calcareous conditions. However, the generation of gunningite (ZnSO4·H2O)-like phase was predominant bulk-solution system. Quantification of damage rates ranges from 75 to 90% of bulb cells under non-carbonated conditions after 15-30 days, while 50-75% of damage level is determined under neutral-alkaline carbonated conditions. Damage ratios are 70.08 and 30.26 at the highest level, respectively. These findings revealed lower ecotoxic damage due to ZnCO3-like precipitation, indicating the effect of carbonates on Zn compounds during vegetable up-taking (exposure). Other environmental suggestions of the (Fe, Zn)S weathering and ecotoxic effects under calcareous soil conditions are discussed.


Assuntos
Cebolas , Poluentes do Solo , Compostos de Zinco , Solo/química , Sulfetos/química , Tempo (Meteorologia) , Poluentes do Solo/análise
3.
Appl Radiat Isot ; 202: 111069, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37857175

RESUMO

The thermoluminescence (TL) of calcium silicate phosphor (CSO) prepared by the sol-gel method and sintered at 1200 °C were investigated. From Tm-Tstop curve, TL emission spectrum and computer deconvolution using electron traps with discrete and continuous distributions, the glow curves were found to be composed of four TL peaks (117, 190, 250 and 275 °C) with a single emission band centered at 370 nm. Electron paramagnetic resonance (EPR) investigation has been carried out to identify the defect centers formed in the CSO phosphor by γ-irradiation and find the centers related to the TL process in the phosphor. At room temperature, three defect centers were observed. The first center, characterized by the principal g-values of 2.014, 2.011, and 2.0080 was assigned to an O- ion. The second center with g-values 2.015, 2.013, and 2.010 is also attributed to an O- ion and is associated with the TL peak at 280 °C. The third center, with an isotropic g-value of 2.0011 was identified as the F+ center (singly ionized oxygen vacancy) and relates to the TL peak at 280 °C.

4.
Data Brief ; 50: 109552, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37743885

RESUMO

This paper presents the Synthetic Polyphonic Ambient Sound Source (SPASS) dataset, a publicly available synthetic polyphonic audio dataset. SPASS was designed to train deep neural networks effectively for polyphonic sound event detection (PSED) in urban soundscapes. SPASS contains synthetic recordings from five virtual environments: park, square, street, market, and waterfront. The data collection process consisted of the curation of different monophonic sound sources following a hierarchical class taxonomy, the configuration of the virtual environments with the RAVEN software library, the generation of all stimuli, and the processing of this data to create synthetic recordings of polyphonic sound events with their associated metadata. The dataset contains 5000 audio clips per environment, i.e., 25,000 stimuli of 10 s each, virtually recorded at a sampling rate of 44.1 kHz. This effort is part of the project ``Integrated System for the Analysis of Environmental Sound Sources: FuSA System'' in the city of Valdivia, Chile, which aims to develop a system for detecting and classifying environmental sound sources through deep Artificial Neural Network (ANN) models.

5.
Chemosphere ; 342: 140133, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37704085

RESUMO

This study aims the development of photoelectrodes to be incorporated in a photoelectrocatalytic ozonation (PECO) process for tertiary treatment of urban wastewaters, targeting the removal of contaminants of emerging concern (CEC). PECO tests were performed using urban wastewater after secondary treatment fortified with Cefadroxil (CFX, C16H17N3O5S), as target model CEC. Three Nitrogen and Carbon doped TiO2 (CN-TiO2) electrodes were synthesized by anodizing at 50, 70, and 90 V, and calcined. These materials were characterized by X-Ray diffraction and Rietveld refinement, Scanning Electron Microscopy, Diffuse Reflectance Spectroscopy, X-ray photoelectron spectroscopy, chronoamperometry, and electrochemical impedance spectroscopy, to correlate defects with photoactivity. All photoanodes considerably reduced their main bandgaps by the incorporation of C and N species, to enable absorption capacities in the UV region using a Xe lamp. The lowest oxygen vacancy content and largest crystallite size were found for CN-TiO2-70, favoring the reduction of bulk defects that could act as recombination of charge carriers. Therefore, oxygen vacancies affect more the TiO2 photoactivity compared to the crystallite size or the light absorption capacity, confirming that a lower content of vacancies in the material bulk and surface doping significantly influence the activity as detected by Rietveld refinement, DRS, and XPS. The electrochemical techniques confirm that the highest photocurrent was obtained for CN-TiO2-70, whence this photoanode was chosen to carry out the CFX degradation. A point defect model simulating Nyquist plot reveals that the photoactivity depends on the speed to diffuse oxygen vacancies through the TiO2 coating. All abatement processes were followed by high-performance liquid chromatography, and Total Organic Carbon (TOC). At neutral and alkaline conditions, CFX is eliminated to levels below the analytical detection limit after 90 min of treatment (TOC removals of 87 and 91%, respectively), indicating that the coupling between the CN-TiO2-70 photocatalyst and ozone is effective in eliminating the contaminant due to parallel routes forming •OH species. Lower CFX degradation observed at acidic pH (TOC removal of 70%) is assigned to the difficulty of oxidizing protonated CFX species.


Assuntos
Luz , Oxigênio , Microscopia Eletrônica de Varredura , Titânio/química , Carbono/química
6.
Micromachines (Basel) ; 14(7)2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37512721

RESUMO

Nanofibers, which are formed by the electrospinning process, are used in a variety of applications. For this purpose, a specific diameter suited for each application is required, which is achieved by varying a set of parameters. This parameter adjustment process is empirical and works by trial and error, causing high input costs and wasting time and financial resources. In this work, an artificial neural network model is presented to predict the diameter of polyethylene nanofibers, based on the adjustment of 15 parameters. The model was trained from 105 records from data obtained from the literature and was then validated with nine nanofibers that were obtained and measured in the laboratory. The average error between the actual results was 2.29%. This result differs from those taken in an evaluation of the dataset. Therefore, the importance of increasing the dataset and the validation using independent data is highlighted.

7.
J Int Med Res ; 51(5): 3000605231173795, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37170749

RESUMO

OBJECTIVE: We evaluated the discriminatory ability of variations in lymphocyte, D-dimer, C-reactive protein (CRP), and lactate dehydrogenase (LDH) serum levels at 48 to 72 hours of hospitalization compared with baseline measurements to predict unfavorable clinical outcomes in patients with COVID-19. METHODS: We analyzed diagnostic test results based on a retrospective cohort to determine the ability of variations (gradients or ratios) in patients' lymphocyte, D-dimer, CRP, and LDH serum levels taken 48 to 72 hours after hospital admission to predict adverse outcomes such as death, mechanical ventilation, or intensive care unit (ICU) admission developing. RESULTS: Among 810 patients (56.1% men, age 61.6 ± 16.2 years), 37.5% had at least one adverse outcome; 28.2% required ICU admission, 26.5% required mechanical ventilation, and 19.4% died during hospitalization. In comparing baseline measurements with measurements at 48 to 72 hours, D-dimer, lymphocyte delta, LDH, and CRP had similar discriminatory ability (area under the receiver operating characteristic curve [AUC] 0.57 vs. 0.56, 0.53 vs. 0.57, 0.64 vs. 0.66, and 0.62 vs. 0.65, respectively). CONCLUSIONS: Measuring serum risk markers upon hospital admission can be used to evaluate risk of adverse outcomes in hospitalized patients with COVID-19. Repeating these measurements at 48 to 72 hours does not improve discriminatory ability.


Assuntos
COVID-19 , Masculino , Humanos , Pessoa de Meia-Idade , Idoso , Feminino , COVID-19/diagnóstico , Proteína C-Reativa/análise , Estudos Retrospectivos , Biomarcadores , Linfócitos
8.
Appl Radiat Isot ; 182: 110126, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35114478

RESUMO

In this study, the thermoluminescence (TL) properties of natural NaCl from Lluta, Arequipa-Peru was investigated. The number of peaks and the kinetic parameters associated with the TL glow peaks of NaCl sample after gamma-irradiation were analyzed by initial rise and deconvolution method. Defect centers induced in pure salt by gamma irradiation have been studied by electron spin resonance (ESR) with a view to identify the centers associated with the TL process in the salt. Thermal annealing experiments indicate the presence of three defect centers. Center I characterized by the g-value 2.011 is identified as an O- ion and relates with the dominant TL peak at 220 °C. Center II with a g-value of 2.0058 is attributed to a F center and is found to correlate with the 128 °C TL peak. Center III has of g-value 2.014 and is also assigned to an O- ion.

9.
Environ Sci Pollut Res Int ; 29(28): 42201-42214, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34467494

RESUMO

The aim of this study is to propose a continuous physicochemical model accounting for the active chlorine production used to degrade recalcitrant sulfamethoxazole (SMX) in an electrochemical flow reactor. The computational model describes the fluid mechanics and mass transfer occurring in the re/actor, along with the electrode kinetics of hydrogen evolution reaction arising on a stainless steel cathode, and the chloride oxidation on a DSA. Specifically, the anodic contributions assume the heterogeneous nature of the adsorbed chlorine species formed on this surface, which are a model requirement to correctly define the experimental reactor performance and degradation efficiency of the contaminant. The experimental validation conducted at different applied current densities, volumetric flows, and chloride concentrations is adequately explained by the model, thus evidencing some of the phenomena controlling the electrocatalytic chlorine production for environmental applications. The best conditions to eliminate the SMX are proposed based on the theoretical analysis of the current efficiency calculated with the model, and experimentally confirmed. The use of the Ti/RuO2-ZrO2-Sb2O3 anode at the bench scale improves the SMX removal by using electro-generated chlorine species adsorbed on its surface, which remarkably increases the oxidation potential of the system along with chlorine desorbed from the electrode. This is a technological innovation concerning other mediated oxidation methods entirely using oxidants in solution.


Assuntos
Sulfametoxazol , Poluentes Químicos da Água , Cloretos , Cloro/análise , Eletrodos , Oxirredução , Poluentes Químicos da Água/análise
10.
Sci Total Environ ; 793: 148541, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34182456

RESUMO

Urban greenspace soundscapes can contribute to the restorative effects that nature provides for the psychological and emotional health of people when certain conditions are met. The main objective of this paper is to propose practical criteria to help planners and managers in the design, development and preservation of urban greenspaces whose soundscapes may contribute to the renewal of health. Systematic literature review informed a conceptual potential Health Restoration Soundscapes (HeReS) model, based on five conditions: (1) Naturalness, (2) Sound Levels, (3) Perceived Sound Sources, (4) Soundscape Assessment, and (5) Sensescape Coherence and proposed Health Restoration Soundscapes Criteria (HeReS-C), for HeReS evaluation in urban green areas. The HeReS-C were applied in 21 sites in Argentina, Sweden, and Chile. General results are provided for all 21 sites, along with three in-depth profiles of HeReS-C applications that provide case studies across a range of resulting HeReS-C scenarios, including sites that meet the HeReS-C criteria, those that do not, and sites that could qualify in the future, if appropriate management measures are taken. HeReS-C showed to be a promising tool for the recognition of potential health-restoring soundscapes in urban greenspaces; informing their design and management to favor the well-being and health of the population.


Assuntos
Parques Recreativos , Som , Argentina , Humanos , Saúde Mental , Reconhecimento Psicológico
11.
Front Neurol ; 12: 599498, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33692737

RESUMO

Background: Actual clinical management of ischemic stroke (IS) is based on restoring cerebral blood flow using tissue plasminogen activator (tPA) and/or endovascular treatment (EVT). Mechanical thrombectomy has permitted the analysis of thrombus structural and cellular classic components. Nevertheless, histological assessment of hemostatic parameters such as thrombin-activatable fibrinolysis inhibitor (TAFI) and matrix metalloproteinase 10 (MMP-10) remains unknown, although their presence could determine thrombus stability and its response to thrombolytic treatment, improving patient's outcome. Methods: We collected thrombi (n = 45) from large vessel occlusion (LVO) stroke patients (n = 53) and performed a histological analysis of different hemostatic parameters [TAFI, MMP-10, von Willebrand factor (VWF), and fibrin] and cellular components (erythrocytes, leukocytes, macrophages, lymphocytes, and platelets). Additionally, we evaluated the association of these parameters with plasma levels of MMP-10, TAFI and VWF activity and recorded clinical variables. Results: In this study, we report for the first time the presence of MMP-10 and TAFI in all thrombi collected from LVO patients. Both proteins were localized in regions of inflammatory cells, surrounded by erythrocyte and platelet-rich areas, and their content was significantly associated (r = 0.41, p < 0.01). Thrombus TAFI was lower in patients who died during the first 3 months after stroke onset [odds ratio (OR) (95%CI); 0.59 (0.36-0.98), p = 0.043]. Likewise, we observed that thrombus MMP-10 was inversely correlated with the amount of VWF (r = -0.30, p < 0.05). Besides, VWF was associated with the presence of leukocytes (r = 0.37, p < 0.05), platelets (r = 0.32, p < 0.05), and 3 months mortality [OR (95%CI); 4.5 (1.2-17.1), p = 0.029]. Finally, plasma levels of TAFI correlated with circulating and thrombus platelets, while plasma MMP-10 was associated with cardiovascular risk factors and functional dependence at 3 months. Conclusions: The present study suggests that the composition and distribution of thrombus hemostatic components might have clinical impact by influencing the response to pharmacological and mechanical therapies as well as guiding the development of new therapeutic strategies.

12.
Environ Sci Pollut Res Int ; 27(18): 22184-22194, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32034590

RESUMO

The carbamazepine (CBZ) abatement is herein evaluated using catalytic ozonation at different NiO concentrations as catalyst: 100, 300, and 500 mg L-1, revealing its total destruction after 5 min of reaction either by conventional or catalytic ozonation. The NiO incorporation in the reactor does not increase the destruction rate, but the catalyst presence enhances the partial mineralization of the contaminant by conversion into oxalic and formic acids and the removal of total organic carbon (TOC) associated with the formation of oxidant species such as hydroxyl radical. Evidence for this behavior is the accumulation rate of the above acids which rise proportionally to the NiO concentration. The highest NiO concentration (500 mg L-1) reached a maximum TOC removal of 79.2%, which exceeds by 50% the outcome of the conventional treatment. The accumulation-decomposition profiles of oxalic and formic acids suggest the occurrence of simultaneous reaction mechanisms (hydroxyl radicals and complex formations) on the catalyst during CBZ ozonation. According to XPS analysis, the presence of nitrogen species in the NiO-ozonated was attributable to byproducts of CBZ decomposition. The toxicity bioassay based on Lactuca sativa seeds demonstrate that ozonated samples attained similar plant germination than the reference substance (water) after 120 min of treatment. This result is comparable with or without the catalyst presence, indicating the formation of non-toxic accumulated byproducts at the end of the ozonation reaction.


Assuntos
Ozônio , Poluentes Químicos da Água/análise , Purificação da Água , Carbamazepina , Catálise
13.
J Phys Chem A ; 124(3): 573-581, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31876420

RESUMO

The joint density functional theory (JDFT) is applied in the context of the grand canonical Kohn-Sham theory to calculate the global and local softness of pristine and N-substituted graphene structures. A comparison is established between the different theoretical approaches to evaluate total capacitance, revealing that the JDFT approach presents the closest result of this property with experimental data. A model of series capacitors is used to determine the quantum and nonquantum contributions of total capacitance, which enables us to determine the limitations of the rigid band approximation for the studied systems. It is found that global chemical softness is proportional to the total capacitance measured in the experiments, when the geometry relaxation is neglected. In this context, it is possible to obtain quantum and total capacitance (and consequently softness) from an average number of electrons vs applied potential plots and the model of series capacitors. Likewise, the relation of capacitance and softness gives rise to a new definition of local capacitance within the JDFT formalism. The evaluation of global and local softness paves the way to analyze electrochemical surface reactivity as a function of applied potential for a solid-electrolyte interface.

14.
Appl Radiat Isot ; 155: 108930, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31629293

RESUMO

Pottery fragments from the Yumina archaeological site, Arequipa, Peru, were dated by means of thermoluminescence (TL) and optically stimulated luminescence (OSL). Electron paramagnetic resonance (EPR) technique was used to study the firing temperature using the iron signal (Fe3+) as a firing temperature reference. The ages of the samples were found to be between 1190 ±â€¯30 and 1240 ±â€¯80 years (777 ±â€¯80 and 827 ±â€¯30 A.D.) determined by both techniques. The firing temperature of ceramics was found to be around 550  ± 50 °C. Our study, based on the combination of TL and OSL techniques to study Yumina archaeological site pottery, will be helpful for archaeologists in Peru. With the results of this investigation, we can understand the chronology and determine the areas of dispersion and density of the archaeological occupation in the Arequipa Valley. In addition, the calculated ages are consistent with the occupation period of the Yumina archaeological site estimated by stratigraphic analysis of the potteries.

15.
Appl Radiat Isot ; 153: 108847, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31536934

RESUMO

In the present work, carbonate samples covering wall painting of four points in the same site found at Peruaçu National Park in the extreme northwest of the state of Minas Gerais, Brazil, has been investigated and dated by thermoluminescence (TL) and electron paramagnetic resonance (EPR) techniques. The EPR spectrum of the carbonate samples presented the typical six signals due to Mn2+ ion and signals around g~2.0 due to SO2- and CO2-. The thermal stability and dose response of the EPR signals were found to be suitable for an age determination using the center due to CO2-. The carbonate sample exhibits TL peaks at approximately 350 °C. TL and EPR dating of the carbonate samples that covered the cave paintings gave an age of 33.13 to 48.40 ka. This series of dating data indicate that in the region about 220-250 km from the coast and extending from the State of Piaui, Bahia to Minas Gerais people lived around 50000 years ago.

16.
Rev. colomb. cardiol ; 26(2): 93-98, mar.-abr. 2019. graf
Artigo em Espanhol | LILACS, COLNAL | ID: biblio-1058390

RESUMO

Resumen El Síndrome de apnea - hipopnea obstructiva del sueño es una enfermedad con compromiso multisistémico, con especial repercusión en el sistema cardiovascular y por tanto con alto impacto en la morbimortalidad general. Se han demostrado múltiples mecanismos fisiopatológicos que explican y sugieren una asociación directa y proporcional al daño generado por esta entidad, en especial para las taquiarritmias, específicamente para fibrilación auricular y también para las bradiarrimias, con mejoría demostrada tras el tratamiento con presión positiva continua de la vía aérea. La asociación con aleteo auricular y arritmias ventriculares ha mostrado resultados contradictorios en algunos estudios, por lo que aún no es tan clara.


Abstract Obstructive sleep apnoea / hypopnoea syndrome is a disease of multisystemic involvement, with particular repercussions on the cardiovascular system, and thus a high impact on morbidity and mortality. Several pathophysiological mechanisms have been demonstrated that explain and suggest a direct and proportional relationship to the damaged caused by the condition, especially for tachyarrhythmias, specifically for atrial fibrillation, and also for bradyarrhythmias, with a demonstrated improvement with continuous positive airway pressure. As the association with atrial flutter and ventricular arrhythmias has shown contradictory results in some studies, the relationship is still not clear.


Assuntos
Arritmias Cardíacas , Apneia Obstrutiva do Sono , Fibrilação Atrial , Sono , Literatura
17.
Sci Total Environ ; 648: 377-387, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30121037

RESUMO

The elimination of cephalexin (CPX) using electro-generated Cl2-active on Ti/RuO2-IrO2 anode was assessed in different effluents: deionized water (DW), municipal wastewater (MWW) and urine. Single Ti/RuO2 and Ti/IrO2 catalysts were prepared to compare their morphologies and electrochemical behavior against the binary DSA. XRD and profile refinement suggest that Ti/RuO2-IrO2 forms a solid solution, where RuO2 and IrO2 growths are oriented by the TiO2 substrate through substitution of Ir by Ru atoms within its rutile-type structure. SEM reveals mud-cracked structures with flat areas for all catalysts, while EDS analysis indicates atomic ratios in the range of the oxide stoichiometries in the nominal concentrations used during synthesis. A considerably higher CPX degradation is achieved in the presence of NaCl than in Na2SO4 or Na3PO4 media due to the active chlorine generation. A faster CPX degradation is reached when the current density is increased or the pH value is lowered. This last behavior may be ascribed to an acid-catalyzed reaction between HClO and CPX. Degradation rates of 22.5, 3.96, and 0.576 µmol L-1 min-1 were observed for DW, MWW and urine, respectively. The lower efficiency measured in these last two effluents was related to the presence of organic matter and urea in the matrix. A degradation pathway is proposed based on HPLC-DAD and HPLC-MS analysis, indicating the fast formation (5 min) of CPX-(S)-sulfoxide and CPX-(R)-sulfoxide, generated due the Cl2-active attack at the CPX thioether. Furthermore, antimicrobial activity elimination of the treated solution is reached once CPX, and the initial by-products are considerably eliminated. Finally, even if only 16% of initial TOC is removed, BOD5 tests prove the ability of electro-generated Cl2-active to transform the antibiotic into biodegradable compounds. A similar strategy can be used for the abatement of other recalcitrant compounds contained in real water matrices such as urine and municipal wastewaters.


Assuntos
Cefalexina/análise , Cloro/química , Irídio/química , Rutênio/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Antibacterianos/análise , Eletrodos , Águas Residuárias/análise
18.
J Acoust Soc Am ; 144(5): 2998, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30522287

RESUMO

This paper applies ideas originally developed in the field of acoustics of multiscale porous media to the analytical modeling of dissipative silencers. Analytical models for the long-wavelength acoustical properties of different types of dissipative silencers, such as pod silencers, lined ducts, splitters, and bar silencers, are introduced in this work. Some of these models account for the possibility of using different porous materials in a given silencer. For instance, a model for a splitter silencer comprising baffles made of different porous materials is derived. Examples of the sound transmission behavior of the said types of silencers are presented to evidence that the dissipation of sound energy is largely influenced by pressure diffusion occurring in the porous constituents. The predictions of the analytical models are in good agreement with finite element calculations.

19.
Med. interna Méx ; 34(5): 715-729, sep.-oct. 2018. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-984735

RESUMO

Resumen: La embolia pulmonar es una enfermedad de alta incidencia a pesar del subdiagnóstico y acarrea alto riesgo de morbilidad y mortalidad. Las herramientas preprueba actuales (clínica, escalas de probabilidad y dímero D) han permitido optimizar la precisión diagnóstica con miras a seleccionar al subgrupo de pacientes que obtendrán el mayor beneficio de la práctica de una angiotomografía para establecer el diagnóstico de embolia pulmonar. Este artículo revisa críticamente la evidencia publicada de la escala de predicción clínica PERC y el ajuste del dímero D por edad para el diagnóstico de embolia pulmonar aguda. Se hizo una revisión estructurada de la bibliografía médica en las bases de datos PubMed, TripDatabase y Epistemonikos. La búsqueda se limitó a metanálisis, estudios aleatorios, estudios de cohorte y guías de manejo, sin límites en idioma o fecha de publicación, utilizando los términos MESH d-dimer, pulmonary embolism, diagnosis y Pulmonary Embolism Rule-Out Criteria. Se hizo la lectura del título y el resumen de 1512 referencias de las que se seleccionaron 50 que fueron representativas para el tema de esta revisión; después de una clasificación y extracción de los datos se procedió a la redacción del texto. La escala PERC y el dímero D ajustado por edad son estrategias recomendadas en el abordaje diagnóstico del paciente con embolia pulmonar.


Abstract: Pulmonary embolism is a high incidence disease despite underdiagnosis and carries a high risk of morbidity and mortality. The current pre-test tools (clinical, probability scales and D-dimer) have allowed to optimize the diagnostic accuracy, since it is problematic to select the subgroup of patients who will obtain a greater benefit from the practice of an angiotomography to establish the diagnosis of pulmonary embolism. This paper reviews critically the published evidence on the PERC scale and the adjusting of the D-dimer with age for the diagnosis of acute pulmonary embolism. As structured review of the medical literature on PubMed, Tripdatabase and Epistemonikos databases was made. Search was limited to meta-analysis, randomized studies, cohort studies, review articles and treatment guidelines without limits on language or date of publication, using MESH terms: d-dimer, pulmonary embolism, diagnosis. It was performed the reading of the title and abstract of 1512 references of which 50 were selected as representative for the subject of this review. We wrote the manuscript after classification and data extraction. The use of the PERC scale and age-adjusted D-dimer are recommended in the diagnostic approach of the patient with pulmonary embolism.

20.
Chemosphere ; 210: 320-333, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30005354

RESUMO

A geochemical-environmental mapping was carried for a low polluted forest in North-western Mexico (Santiago Papasquiaro mining area), as part of the North American forests accounting for environmental behavior of arsenic (As), lead (Pb), zinc (Zn) and copper (Cu) in soil and tree components (stem wood and aciculums). Spectroscopic and microscopic techniques along with standard protocols were used to determine the mineralogical phases containing these elements, and their corresponding spatial distributions in soil and forests and mobility. In soil, total As, Pb, Zn and Cu ranged from 4.9 to 98.3, 19.6 to 768.6, 19.6 to 407.1, and 1.6 to 63.8 mg kg-1, respectively. Ultrafine particles (<5-10 µm) of arsenopyrite and sphalerite (and complex Zn-Fe phase) were the main As and Zn-bearing phases determined by SEM-EDS, respectively. Complex Pb-Cu-Fe and Cu-O oxide-like phases were the only ones containing Pb and Cu, respectively. Mobility was low for Pb, Zn and Cu, whereas a significant mobility was assessed for As. Concentrations vs. depth profiles suggested progressive accumulations of As, Pb, Zn and Cu in top soil. Total As, Pb, Zn and Cu in pine stem wood varied from 11.5 to 184.5, 98.9 to 7359.8, 3242.7 to 22197.3, 689.2 to 7179.6 µg kg-1, respectively. The respective concentrations in the pine needles ranged from 50 to 624.2, 100 to 16353.1, 120 to 46440.9 and 720 to 7200 µg kg-1, indicating an active bioaccumulation of As, Pb, Zn and Cu. A prospective environmental behavior was discussed for As, Pb, Zn and Cu in the low-polluted forest.


Assuntos
Arsênio/análise , Cobre/análise , Ecossistema , Chumbo/análise , Poluentes do Solo/análise , Solo/química , Zinco/análise , Arsênio/metabolismo , Disponibilidade Biológica , Cobre/metabolismo , Monitoramento Ambiental , Florestas , Chumbo/metabolismo , México , Poluentes do Solo/metabolismo , Zinco/metabolismo
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