ABSTRACT
The concentrations of U-238, Th-232, and K-40 measured with a portable gamma-ray spectrometer in cutting samples of two exploratory wells allowed the radiometric characterization of Cretaceous Rancheria sub-basin rocks and the definition of twelve (12) zones according to paleo-redox facies. The Th/Ua (authigenic uranium) and Th/U ratio greater than 7 (seven) indicates paleo-redox conditions related to oxygenation changes and detrital material input during deposition and terrestrial freshwater environment. However, the Lagunitas, Aguas Blancas, La Luna, and Molino formations characterize by facies from sub-oxic (dioxic) to anoxic redox. In the Aguas Blancas and Molino Formations, pyrite and the high uranium measurements determine an anoxic and euxinic environment. The high values of both + uranium and authigenic uranium in the La Luna and Molino formations relate to the conservation of organic matter, which is an essential factor in the generation of hydrocarbons. The abrupt changes of both K/U and Th/U identify potential sequential or genetic limit surfaces (e.g., maximum flooding surfaces), limiting such zones. Based on radiometric behavior, this research permitted identifying eight Cretaceous to Miocene unconformities in the area, three of them reported here for the first time.
ABSTRACT
This study explores differences on health status transitions based on functional health and dead records among older population in Europe. We also study the influence of residence pattern on health changes over time. METHOD: Data used came from EU-SILC registers on individuals aged 50 + from 19 countries. Fixed and Mixed effect Cox Proportional Hazards Models are used to ascertain any country differences on health outcomes and then by co-residence pattern. RESULTS: There are remarkable country heterogeneity among older people to experience changes on their health status, specially, for health improvements and mortality risk. As expected, Baltic and Eastern European countries have a higher propensity for health deterioration and Southern European countries for health improvements on their functional capacities. However, there are exceptions as Bulgaria and Romania, which have a lower risk of deterioration and death transition than average. Overall, living with partner and adult children-rather than living only with a couple shown positive effects for older European to experience health improvements with notably differences in Southern countries as in Italy and Spain. DISCUSSION: country framework differences play a fundamental role to understand changes on health status at older ages, in particular, how health care support toward older people is managed by health systems within European countries and the availability of close relatives among older adult population.
Subject(s)
Health Status , Social Environment , Humans , Aged , Europe/epidemiology , Italy , SpainABSTRACT
Biological nitrogen fixation (BNF) is a process through which a group of microorganisms called diazotrophs convert unassimilable atmospheric nitrogen into ammonia. In aqueous media, ammonia yields ammonium ions that can be assimilated by microorganisms and plants. To reduce the application of nitrogen fertilizers and their environmental effects, an alternative approach toward sustainable agriculture is the induction of artificial associations between diazotrophs and plants. This has led to increased interest in the search for microorganisms capable of supplying nitrogen to crops. This article presents a simple, economical, and sensitive spectrophotometric method for estimating the BNF capacity of bacteria cultured in a liquid NFb medium, based on the variation of absorbance caused by the change in color of bromothymol blue in the culture medium. The structure and color of this indicator are modified by pH shifts, which depend on the concentration of fixed ammonium ions.â¢The nitrogen concentration (estimated from the ammonium in the culture medium) showed a positive correlation (R 2 = 0.984) with the absorbance measured at 610 nm. The regression equation obtained through the origin was y = 0.009682140x, where y is the absorbance and x is the nitrogen concentration in the culture medium.â¢The methods used at present to measure the efficiency of BNF require expensive equipment, which may not be affordable for many laboratories or companies working in this field.â¢This technique can be used for pure bacterial strains and microbial consortia from soil or commercial products.
ABSTRACT
Resumen Objetivos: Describir las características clínicas y de laboratorio de los pacientes diabéticos tipo 2 (DM2) en tratamiento con fibrina rica en plaquetas (FRP) en el Hospital Clínico Herminda Martín entre los años 2014 y 2016. Materiales y Método: Se revisaron las fichas clínicas de todos los pacientes tratados con FRP en el policlínico de biomateriales en busca de los valores de HbA1c y glicemia, además de otras variables clínicas y de laboratorio que pudieren estar relacionadas con la evolución de las heridas de pie diabético. Se estableció tres grupos de comparación según el tiempo de cicatrización en cicatrización rápida (tiempo percentil 75). Resultados: De un universo de 147 pacientes con DM2 se reportan resultados de 85 (58%). El promedio de edad fue de 61 años, con una glicemia promedio de 243 g/dL y HbA1c de 9,4%. Presentaron un contaje plaquetario dentro de los parámetros normales (promedio 279 plaquetas/mm3). Se encontraron diferencias estadísticas en la escala de valoración de heridas, específicamente en la valoración del puntaje total, así como los parámetros como extensión, profundidad, y dolor entre los grupos de cicatrización rápida y lenta. No se evidenciaron diferencias en el nivel de HbA1c o glicemia en los grupos de cicatrización rápida o lenta, como tampoco en otras variables como edad, creatinina, recuento de plaquetas. Conclusión: No se encontró una asociación entre la velocidad de cicatrización y el nivel de HbA1c en individuos tratados con FRP.
Aims: To describe the clinical and laboratory characteristics of type 2 diabetic patients (DM2) treated with Platelet Rich Fibrin (FRP) at Hospital Clínico Herminda Martín between 2014 and 2016. Materials and Method: Analytical study that includes information from a secondary database. The clinical records of all patients treated with FRP at the Biomaterials Polyclinic were reviewed to search the HbA1c and glycemia values, as well as other clinical and laboratory variables that could be related to the evolution of diabetic foot wounds. Three comparison groups were established according to the healing time in rapid (time 75th percentile). Results: From a universe of 147 patients with DM2, results of 85 (58%) are reported. The average age in the included patients was 61 years. They had an average glycaemia of 243 g/dL, and HbA1c of 9.4%. They presented a platelet count within normal range (average 279 platelets/mm3). Statistical differences between the fast and slow healing groups were found in the wound assessment scale, specifically in the assessment of the total score, extension, depth, and pain. There were no differences in the HbA1c or glycemia level in the fast or slow healing groups, nor in other variables such as age, creatinine, and platelet count. Conclusion: No association was found between healing speed and HbA1c level in individuals treated with FRP.
Subject(s)
Humans , Middle Aged , Ulcer , Diabetic Foot , Platelet-Rich Fibrin , Wound Healing , Multivariate Analysis , Retrospective Studies , Metabolism/physiologyABSTRACT
INTRODUCTION: Gastric heterotopy is a rare entity in the pediatric population. It occurs in the gastrointestinal tract, leading to digestive bleeding. CLINICAL CASE: This is the case of a 10-year-old boy with gastric tissue in the proximal jejunum, which caused two massive digestive bleeding episodes. Diagnostic techniques included endoscopic capsule, enteroscopy, and biopsy. The patient was scheduled for laparotomy and resection. After one year of follow-up, he remained asymptomatic. DISCUSSION: Gastric heterotopy approach represents a diagnostic challenge. Owing to how rare it is, there is no global consensus in terms of treatment. However, surgery is the definitive therapy. In this case, decision was made not to perform intestinal resection and anastomosis, but resection of the compromised intestinal wall. No malignity was reported in the literature reviewed.
INTRODUCCION: La heterotopia gástrica es una entidad infrecuente en la población pediátrica. Se presenta en el tracto gastrointestinal llevando a cuadros clínicos de sangrado digestivo. CASO CLINICO: Se reporta el caso de un escolar de 10 años, el cual presentó tejido gástrico en el yeyuno proximal, originando sangrado digestivo masivo en dos ocasiones. La secuencia de apoyos diagnósticos requirió cápsula endoscópica, enteroscopia y biopsia. Fue llevado a laparotomía y resección de la lesión. En el seguimiento al año se mantuvo asintomático. DISCUSION: Su abordaje genera un reto diagnóstico. Debido a su infrecuente presentación no hay un consenso global para el tratamiento, sin embargo, la intervención quirúrgica es la terapia definitiva. En este caso no se hizo resección intestinal y anastomosis sino resección de la pared intestinal comprometida. No se reportó malignidad en la literatura revisada.
Subject(s)
Gastrointestinal Hemorrhage , Laparoscopy , Anastomosis, Surgical , Biopsy , Child , Gastrointestinal Hemorrhage/diagnosis , Gastrointestinal Hemorrhage/etiology , Gastrointestinal Hemorrhage/surgery , Humans , Jejunum , MaleABSTRACT
Introducción: La heterotopia gástrica es una entidad infrecuente enla población pediátrica. Se presenta en el tracto gastrointestinal llevandoa cuadros clínicos de sangrado digestivo. Caso clínico: Se reporta el caso de un escolar de 10 años, el cualpresentó tejido gástrico en el yeyuno proximal, originando sangradodigestivo masivo en dos ocasiones. La secuencia de apoyos diagnósti-cos requirió cápsula endoscópica, enteroscopia y biopsia. Fue llevadoa laparotomía y resección de la lesión. En el seguimiento al año semantuvo asintomático. Discusión: Su abordaje genera un reto diagnóstico. Debido a suinfrecuente presentación no hay un consenso global para el tratamien-to, sin embargo, la intervención quirúrgica es la terapia definitiva. Eneste caso no se hizo resección intestinal y anastomosis sino resecciónde la pared intestinal comprometida. No se reportó malignidad en laliteratura revisada.(AU)
Introduction: Gastric heterotopy is a rare entity in the pediatricpopulation. It occurs in the gastrointestinal tract, leading to digestivebleeding. Clinical case: This is the case of a 10-year-old boy with gastrictissue in the proximal jejunum, which caused two massive digestivebleeding episodes. Diagnostic techniques included endoscopic capsule,enteroscopy, and biopsy. The patient was scheduled for laparotomyand resection. After one year of follow-up, he remained asymptomatic. Discussion: Gastric heterotopy approach represents a diagnosticchallenge. Owing to how rare it is, there is no global consensus in termsof treatment. However, surgery is the definitive therapy. In this case,decision was made not to perform intestinal resection and anastomosis,but resection of the compromised intestinal wall. No malignity wasreported in the literature reviewed.(AU)
Subject(s)
Humans , Male , Child , Jejunum , Gastric Mucosa , Gastrointestinal Hemorrhage , Gastrointestinal Tract/injuries , Pediatrics , General SurgeryABSTRACT
Naturally occurring radioactive elements depend on lithology geogenic characteristics, such as depositional, environmental, or diagenetic. Thus, evaluating these elements constitutes a tool to define ionizing radiation effect from rocky sequences. This study carried out in the Rancheria Sub-Basin establishes both characterization and assessment of this kind of material, known as NORM. The sampling included uranium-238, thorium-232, potassium-40, radon-226, and radon-222 in soil samples, cutting samples from the Molino-1 well, and radon in surface water. Bases on a radiometric methodology with a gamma-ray spectrometer for uranium-238, thorium-232, and potassium-40 and emanometric with ionizing chambers for radio-226 and radon-222. The analysis and results of the activity concentrations in soil samples of U-238, Th-232, K-40, and Ra-226 are 11.7 BqKg-1, 33.0 BqKg-1, 424.5 BqKg-1, and 15.59 BqKg-1, respectively, among the acceptable global averages. However, in some areas, observed values indicate high activity concentrations of U-238, Th-232, K-40, Ra-226, and Rn-222 in the soil of 50.2 BqKg-1, 62.8 BqKg-1, 1596.3 BqKg-1, 44.25 BqKg-1, and 112546.79 Bqm-3, respectively. Those activity concentrations were associated with zone lithology.
Subject(s)
Radiation Monitoring , Radon , Soil Pollutants, Radioactive , Uranium , Potassium Radioisotopes/analysis , Radon/analysis , Soil , Soil Pollutants, Radioactive/analysis , Thorium/analysis , Uranium/analysisABSTRACT
BACKGROUND: Lawsonia intracellularis remains a problem for the swine industry worldwide. Previously, we designed and obtained a vaccine candidate against this pathogen based on the chimeric proteins: OMP1c, OMP2c, and INVASc. These proteins formed inclusion bodies when expressed in E. coli, which induced humoral and cellular immune responses in vaccinated pigs. Also, protection was demonstrated after the challenge. In this study, we established a production process to increase the yields of the three antigens as a vaccine candidate. RESULTS: Batch and fed-batch fermentations were evaluated in different culture conditions using a 2 L bioreactor. A fed-batch culture with a modified Terrific broth medium containing glucose instead of glycerol, and induced with 0.75 mM IPTG at 8 h of culture (11 g/L of biomass) raised the volumetric yield to 627.1 mg/L. Under these culture conditions, plasmid-bearing cells increased by 10% at the induction time. High efficiency in cell disruption was obtained at passage six using a high-pressure homogenizer and a bead mill. The total antigen recovery was 64% (400 mg/L), with a purity degree of 70%. The antigens retained their immunogenicity in pigs, inducing high antibody titers. CONCLUSIONS: Considering that the antigen production process allowed an increment of more than 70-fold, this methodology constitutes a crucial step in the production of this vaccine candidate against L. intracellularis.
Subject(s)
Animals , Swine Diseases/immunology , Bacterial Vaccines/immunology , Lawsonia Bacteria/immunology , Desulfovibrionaceae Infections/prevention & control , Swine , Swine Diseases/prevention & control , Bacterial Vaccines/administration & dosage , Vaccines, Synthetic , Cell Survival , Vaccination , Fermentation , Batch Cell Culture Techniques , ImmunityABSTRACT
Methane (CH4) is a greenhouse gas (GHG) produced and released by eructation to the atmosphere in large volumes by ruminants. Enteric CH4 contributes significantly to global GHG emissions arising from animal agriculture. It has been contended that tropical grasses produce higher emissions of enteric CH4 than temperate grasses, when they are fed to ruminants. A number of experiments have been performed in respiration chambers and head-boxes to assess the enteric CH4 mitigation potential of foliage and pods of tropical plants, as well as nitrates (NO3-) and vegetable oils in practical rations for cattle. On the basis of individual determinations of enteric CH4 carried out in respiration chambers, the average CH4 yield for cattle fed low-quality tropical grasses (>70% ration DM) was 17.0 g CH4/kg DM intake. Results showed that when foliage and ground pods of tropical trees and shrubs were incorporated in cattle rations, methane yield (g CH4/kg DM intake) was decreased by 10% to 25%, depending on plant species and level of intake of the ration. Incorporation of nitrates and vegetable oils in the ration decreased enteric CH4 yield by â¼6% to â¼20%, respectively. Condensed tannins, saponins and starch contained in foliages, pods and seeds of tropical trees and shrubs, as well as nitrates and vegetable oils, can be fed to cattle to mitigate enteric CH4 emissions under smallholder conditions. Strategies for enteric CH4 mitigation in cattle grazing low-quality tropical forages can effectively increase productivity while decreasing enteric CH4 emissions in absolute terms and per unit of product (e.g. meat, milk), thus reducing the contribution of ruminants to GHG emissions and therefore to climate change.
Subject(s)
Greenhouse Gases , Methane , Animal Feed/analysis , Animals , Cattle , Diet/veterinary , Milk , Poaceae , Rumen , RuminantsABSTRACT
BACKGROUND: Asthma is one of the leading chronic illnesses among children in the United States. Asthma prevalence is higher among African Americans (11.2%) compared to European Americans (7.7%). Bronchodilator medications are part of the first-line therapy, and the rescue medication, for acute asthma symptoms. Bronchodilator drug response (BDR) varies substantially among different racial/ethnic groups. Asthma prevalence in African Americans is only 3.5% higher than that of European Americans, however, asthma mortality among African Americans is four times that of European Americans; variation in BDR may play an important role in explaining this health disparity. To improve our understanding of disparate health outcomes in complex phenotypes such as BDR, it is important to consider interactions between environmental and biological variables. RESULTS: We evaluated the impact of pairwise and three-variable interactions between environmental, social, and biological variables on BDR in 233 African American youth with asthma using Visualization of Statistical Epistasis Networks (ViSEN). ViSEN is a non-parametric entropy-based approach able to quantify interaction effects using an information-theory metric known as Information Gain (IG). We performed analyses in the full dataset and in sex-stratified subsets. Our analyses identified several interaction models significantly, and suggestively, associated with BDR. The strongest interaction significantly associated with BDR was a pairwise interaction between pre-natal smoke exposure and socioeconomic status (full dataset IG: 2.78%, p = 0.001; female IG: 7.27%, p = 0.004)). Sex-stratified analyses yielded divergent results for females and males, indicating the presence of sex-specific effects. CONCLUSIONS: Our study identified novel interaction effects significantly, and suggestively, associated with BDR in African American children with asthma. Notably, we found that all of the interactions identified by ViSEN were "pure" interaction effects, in that they were not the result of strong main effects on BDR, highlighting the complexity of the network of biological and environmental factors impacting this phenotype. Several associations uncovered by ViSEN would not have been detected using regression-based methods, thus emphasizing the importance of employing statistical methods optimized to detect both additive and non-additive interaction effects when studying complex phenotypes such as BDR. The information gained in this study increases our understanding and appreciation of the complex nature of the interactions between environmental and health-related factors that influence BDR and will be invaluable to biomedical researchers designing future studies.
ABSTRACT
No disponible
Subject(s)
Humans , Female , Aged , Fasciitis, Necrotizing/drug therapy , Disease Progression , Erythema/diagnosis , Anti-Bacterial Agents/administration & dosageABSTRACT
Resumen El Granuloma Anular (GA) es una dermatosis inflamatoria crónica, benigna, auto limitada, de etiología desconocida. Existen numerosas variantes clínicas dentro de las cuales se encuentra la perforante, de presentación inusual. La histopatología más característica de GA, cuenta con la presencia de histiocitos epitelioides en empalizada alrededor de áreas de degeneración focal de fibras de colágeno con depósitos de mucina. La variedad perforante evidencia eliminación transepidérmica de fibras de colágeno. Se presenta un paciente de 72 años de edad, diabético, dislipémico, con lesiones pruriginosas en dorso de ambas manos, con el diagnóstico de granuloma anular perforante. Realizó tratamiento con clobetasol tópico, más antihistamínicos por vía oral, quedando una cicatriz atrófica.
Abstract Granuloma annulare is a chronic, benign, self-limiting, inflammatory dermatosis of unknown etiology. There are numerous clinical variants within which is the perforating, unusual presentation. The most histopathology characteristic of GA is the presence of palisading epithelioid histiocytes around areas of focal degeneration of collagen with mucin deposits. The perforating variety evidences transepidermal elimination of collagen tissue. A 72 years-old, diabetes, dyslipidemic patient is presented with pruritic lessions on the dorsum of both hands, with the diagnosis of perforating granuloma annulare. I perform medical treatment with topical clobetasol, leaving an atrophic scar.
Subject(s)
Humans , Male , Aged , Granuloma Annulare/diagnosis , Granuloma Annulare/pathology , Granuloma Annulare/therapy , Diabetes Mellitus, Type 2/complications , Diagnosis, Differential , Dyslipidemias/complicationsABSTRACT
Resumen La calcifilaxis es una enfermedad poco frecuente, aunque presenta una elevada tasa de mortalidad debido sobre todo a complicaciones como sepsis o gangrena. Generalmente se asocia a insuficiencia renal severa. Se define como la calcificación de la capa media de vasos de pequeño y mediano tamaño de la dermis y tejido celular subcutáneo. Clínicamente se manifiesta como un síndrome de livedoracemosa que progresa a púrpura retiforme y necrosis cutánea. La primera línea de tratamiento es el tiosulfato sódico.
Abstract Calciphylaxis is a rare disease, although it has a high mortality rate due mainly to complications such as sepsis or gangrene. It is usually associated with severe renal failure. It is defined as the calcification of the middle layer of small and medium-sized vessels of the dermis and subcutaneous cellular tissue. Clinically it manifests as a livedoracemosa syndrome that progresses to retinal purpura and cutaneous necrosis. The first line of treatment is sodium thiosulfate.
Subject(s)
Humans , Male , Middle Aged , Calciphylaxis/diagnosis , Calciphylaxis/therapy , Sepsis/prevention & control , Calciphylaxis/mortality , Diagnosis, Differential , Necrosis/complicationsABSTRACT
Es bien conocido que ha existido en las últimas décadas un incremento en los casos de cáncer diferenciado de tiroides, especialmente los microcarcinomas. Diversos factores han contribuido a pesquisar pequeños cánceres como el aumento de la disponibilidad de exámenes imagenológicos. Estos pequeños cánceres tiroideos pueden tener un comportamiento no agresivo y no producir letalidad; esto es lo que se conoce como sobrediagnóstico. Esto último tiene implicancias tanto médicas como económicas por terapias agresivas. Así, desde el año 2015, un grupo de expertos cambia la nomenclatura en anatomía patológica del carcinoma papilar tiroideo variante folicular encapsulado (NIEFVPTC de sus siglas en inglés) por Neoplasia folicular tiroidea no invasiva con características nucleares de tipo papilar (NIFTP de sus siglas en inglés). Este cambio se basó en un estudio de Nikiforov donde los NIEFVPTC no tenían efectos adversos ni mortalidad en su seguimiento. Así, la intención inicial del cambio de nomenclatura es eliminar la palabra cáncer y evitar los sobretratamientos innecesarios. Presentamos un caso clínico de una paciente que se sometió a cirugía por un nódulo tiroideo clasificado Bethesda III donde la biopsia definitiva posterior a cirugía evidenció que se trataba de un NIFTP. A raíz de este caso analizamos la literatura hasta la fecha de esta nueva entidad y hacemos un repaso histórico de los carcinomas papilares tiroideos variante folicular. Además, desarrollamos nuevas interrogantes que se plantean desde este nuevo diagnóstico anatomopatológico, de cómo sospecharlo previo a una cirugía, cuál es la cirugía de elección, y cómo debiera ser el seguimiento una vez diagnosticado.
It is well known that there has been an increase in cases of differentiated thyroid cancer in recent decades, especially microcarcinomas. Several factors have contributed to diagnose small cancers such as the increased availability of imaging tests. These small thyroid cancers can have a non-aggressive behavior and not cause lethality, this is what is known as overdiagnosis. The latter has medical as well as economic implications for aggressive therapies. Thus, since 2015, a group of experts has changed the nomenclature in pathological anatomy of encapsulated variant papillary thyroid carcinoma (NIEFVPTC) for non-invasive thyroid follicular neoplasia with papillary nuclear characteristics (NIFTP). This change was based on a Nikiforov study where the NIEFVPTC had no adverse effects or mortality in their follow-up; thus, the initial intention of the nomenclature change is to eliminate the word cancer and avoid unnecessary over-treatments. We present a clinical case of a patient who underwent surgery for a thyroid nodule classified Bethesda III where the definitive biopsy after surgery showed that it was a NIFTP. Following this case, we analyze the literature to date of this new entity and make a historical review of the follicular variant papillary thyroid carcinomas. In addition, we develop new questions that arise from this new pathological diagnosis, how to suspect it prior to surgery, what is the surgery of choice, and what should the follow-up once diagnosed.
Subject(s)
Humans , Female , Adult , Thyroid Neoplasms/diagnosis , Thyroid Cancer, Papillary/diagnosis , Biopsy , Thyroid Neoplasms/surgery , Thyroid Neoplasms/pathology , Ultrasonography , Thyroid Cancer, Papillary/surgery , Thyroid Cancer, Papillary/pathologyABSTRACT
Nanocomposites of functionalized carbon nanotubes (CNTsf) as nanofillers, and a copolymer of star-shaped poly(ε-caprolactone) (stPCL) and poly(ethylene glycol) (PEG) as a polymeric matrix were synthesized, characterized, and their resistance to the growth of Staphylococcus aureus and Pseudomonas aeruginosa was evaluated. CNTsf contain hydroxyl, carboxyl and acyl chloride groups attached to their surface. Nanocomposites were prepared by mixing CNTsf to a solution of stPCL-PEG copolymer. Raman and FT-IR spectroscopies confirm the functionalization of carbon nanotubes (CNTs). Star-shaped PCL-PEG copolymer was characterized by Gel permeation chromatography (GPC), and 1H-NMR and 13C-NMR spectroscopies. X-ray photoelectron spectroscopy (XPS) shows that CNTsf are grafted to the stPCL-PEG copolymer. Crystallization behavior of the nanocomposites depends on the amount of CNTsf used in their preparation, detecting nucleation (nanocomposites prepared with 0.5 wt.% of CNTsf) or anti-nucleation (nanocomposites prepared with 1.0 wt.% of CNTsf) effects. Young's Moduli and thermal stability of nanocomposites were higher, but their resistence to the proliferation of Staphylococcus aureus and Pseudomonas aeruginosa was lower than the observed for their pure polymer matrix.
Subject(s)
Anti-Bacterial Agents/chemistry , Ethylene Glycols/chemistry , Nanocomposites/chemistry , Nanotubes, Carbon/chemistry , Polyesters/chemistry , Cell Proliferation/drug effects , Mechanical Phenomena , Pseudomonas aeruginosa/drug effects , Staphylococcus aureus/drug effects , Surface PropertiesABSTRACT
Bright surfaces across the western U.S. lead to uncertainties in satellite derived aerosol optical depth (AOD) where AOD is typically overestimated. With this in mind, a compact and portable instrument was developed to measure surface albedo on an unmanned aircraft system (UAS). This spectral albedometer uses two Hamamatsu micro-spectrometers (range: 340â»780 nm) for measuring incident and reflected solar radiation at the surface. The instrument was deployed on 5 October 2017 in Nevada's Black Rock Desert (BRD) to investigate a region of known high surface reflectance for comparison with albedo products from satellites. It was found that satellite retrievals underestimate surface reflectance compared to the UAS mounted albedometer. To highlight the importance of surface reflectance on the AOD from satellite retrieval algorithms, a 1-D radiative transfer model was used. The simple model was used to determine the sensitivity of AOD with respect to the change in albedo and indicates a large sensitivity of AOD retrievals to surface reflectance for certain combinations of surface albedo and aerosol optical properties. This demonstrates the need to increase the number of surface albedo measurements and an intensive evaluation of albedo satellite retrievals to improve satellite-derived AOD. The portable instrument is suitable for other applications as well.
ABSTRACT
Ambient air particulate matter (<2.5µm in diameter) samples were collected on two different filter types in 2014 and 2015 over 24h periods and analyzed for reactive mercury (gaseous oxidized mercury+particulate bound mercury) concentrations and lead isotopes to determine sources of pollution to three sites in Nevada, USA. Two sites were located on the western edge of Nevada (Reno, urban, 1370m and Peavine Peak, rural, high elevation, 2515m); the third location was ~485km east in rural Great Basin National Park, NV (2061m). Reactive mercury samples were collected on cation exchange membranes simultaneously with lead samples, collected on Teflon membranes. Lead isotopic ratios have previously identified trans-Pacific lead sources based on the 206/207 and 208/207 lead ratios. Influence from trans-Pacific air masses was higher from March to June associated with long-range transport of pollutants. Spring months are well known for increased transport across the Pacific; however, fall months were also influenced by trans-Pacific air masses in this study. Western North American background ozone concentrations have been measured and modeled at 50 to 55ppbv. Median ozone concentrations at both rural sites in Nevada were within this range. Sources leading to enhancements in ozone of 2 to 18ppbv above monthly medians in Nevada included emissions from Eurasia, regional urban centers, and global and regional wildfires, resulting in concentrations close to the USA air quality standard. At the high elevation locations, ozone was derived from pollutants being transported in the free troposphere that originate around the globe; however, Eurasia and Asia were dominant sources to the Western USA. Negative correlations between reactive mercury and percent Asian lead, Northern Eurasia and East Asia trajectories indicated reactive mercury concentrations at the two high elevation sites were produced by oxidants from local, regional, and marine boundary layer sources.
Subject(s)
Air Pollutants/analysis , Environmental Monitoring/methods , Mercury/analysis , Ozone/analysis , Particulate Matter/analysis , Air Pollution/statistics & numerical data , Isotopes , Lead , NevadaABSTRACT
Zinc (Zn)-derived foams have been prepared from an alkaline electrolyte solution by galvanostatic electrodeposition under different conditions. A detailed physico-chemical characterization was performed by Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). A pioneer application of these foams in medical implant-related applications was investigated. The in vitro behaviour of these Zn-derived foams in simulated physiological conditions was studied. The results revealed that the presence of zinc oxide was important enough to change the in vitro behaviour of these materials. The potential of these Zn-derived foams in inhibiting bone cancer cell proliferation - osteoscarcoma cells - and important pathogenic fungi responsible for implant-related infections -Candida albicans- was examined. Furthermore, the foams were evaluated for cytocompatibility with normal human osteoblasts. The results obtained allowed us to conclude that Zn-derived foams have an interesting potential for anti-cancer and anti-Candida activity, targeted for bone-related implant applications, suggesting that this novel material may have potential for further clinical studies.