Search

Molecular analysis of atmospheric microparticles in West Antarctica reveals chlorine-enriched aerosols are abundant in sea salt generated by photolytic products, while ice core records suggest increasing chlorine depletion since the onset of stratospheric ozone reduction.

In this study, aerosol samples collected at a remote site in the Amazonian rainforest and an urban site in Manaus, Brazil, were investigated on a single-particle basis using a quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA). A total of 23 aerosol samples were collected in four size ranges (0.25–0.5, 0.5–1.0, 1.0–2.0, and 2.0–4.0 µm) during the wet season in 2012 at two Amazon basin sites: 10 samples in Manaus, an urban area; and 13 samples at an 80 m high tower, located at the Amazon Tall Tower Observatory (ATTO) site in the middle of the rainforest, 150 km northeast of Manaus. The aerosol particles were classified into nine particle types based on the morphology on the secondary electron images (SEIs) together with the elemental concentrations of 3162 individual particles: (i) secondary organic aerosols (SOA); (ii) ammonium sulfate (AS); (iii) SOA and AS mixtures; (iv) aged mineral dust; (v) reacted sea salts; (vi) primary biological aerosol (PBA); (vii) carbon-rich or elemental carbon (EC) particles, such as soot, tarball, and char; (viii) fly ash; and (ix) heavy metal (HM, such as Fe, Zn, Ni, and Ti)-containing particles. In submicron aerosols collected at the ATTO site, SOA and AS mixture particles were predominant (50 %–94 % in relative abundance) with SOA and ammonium sulfate comprising 73 %–100 %. In supermicron aerosols at the ATTO site, aged mineral dust and sea salts (37 %–70 %) as well as SOA and ammonium sulfate (28 %–58 %) were abundant. PBAs were observed abundantly in the PM2−4 fraction (46 %), and EC and fly ash particles were absent in all size fractions. The analysis of a bulk PM0.25−0.5 aerosol sample from the ATTO site using Raman microspectrometry and attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) showed that ammonium sulfate, organics, and minerals are the major chemical species, which is consistent with the ED-EPMA results. In the submicron aerosols collected in Manaus, either SOA and ammonium sulfate (17 %–80 %) or EC particles (6 %–78 %) were dominant depending on the samples. In contrast, aged mineral dust, reacted sea salt, PBA, SOA, ammonium sulfate, and EC particles comprised most of the supermicron aerosols collected in Manaus. The SOA, ammonium sulfate, and PBAs were mostly of a biogenic origin from the rainforest, whereas the EC and HM-containing particles were of an anthropogenic origin. Based on the different contents of SOA, ammonium sulfate, and EC particles among the samples collected in Manaus, a considerable influence of the rainforest over the city was observed. Aged mineral dust and reacted sea-salt particles, including mineral dust mixed with sea salts probably during long-range transatlantic transport, were abundant in the supermicron fractions at both sites. Among the aged mineral dust and reacted sea-salt particles, sulfate-containing ones outnumbered those containing nitrates and sulfate + nitrate in the ATTO samples. In contrast, particles containing sulfate + nitrate were comparable in number to particles containing sulfate only in the Manaus samples, indicating the different sources and formation mechanisms of secondary aerosols, i.e., the predominant presence of sulfate at the ATTO site from mostly biogenic emissions and the elevated influences of nitrates from anthropogenic activities at the Manaus site.

The intercontinental transport of aerosols from the Sahara desert plays a significant role in nutrient cycles in the Amazon rainforest, since it carries many types of minerals to these otherwise low-fertility lands. Iron is one of the micronutrients essential for plant growth, and its long-range transport might be an important source for the iron-limited Amazon rainforest. This study assesses the bioavailability of iron Fe(II) and Fe(III) in the particulate matter over the Amazon forest, which was transported from the Sahara desert (for the sake of our discussion, this term also includes the Sahel region). The sampling campaign was carried out above and below the forest canopy at the ATTO site (Amazon Tall Tower Observatory), a near-pristine area in the central Amazon Basin, from March to April 2015. Measurements reached peak concentrations for soluble Fe(III) (48 ng m−3), Fe(II) (16 ng m−3), Na (470 ng m−3), Ca (194 ng m−3), K (65 ng m−3), and Mg (89 ng m−3) during a time period of dust transport from the Sahara, as confirmed by ground-based and satellite remote sensing data and air mass backward trajectories. Dust sampled above the Amazon canopy included primary biological aerosols and other coarse particles up to 12 µm in diameter. Atmospheric transport of weathered Saharan dust, followed by surface deposition, resulted in substantial iron bioavailability across the rainforest canopy. The seasonal deposition of dust, rich in soluble iron, and other minerals is likely to assist both bacteria and fungi within the topsoil and on canopy surfaces, and especially benefit highly bioabsorbent species. In this scenario, Saharan dust can provide essential macronutrients and micronutrients to plant roots, and also directly to plant leaves. The influence of this input on the ecology of the forest canopy and topsoil is discussed, and we argue that this influence would likely be different from that of nutrients from the weathered Amazon bedrock, which otherwise provides the main source of soluble mineral nutrients.

Age effects on plasma metabolites, hormone concentrations, and enzyme activities related to energy metabolism were investigated in 20 riding horses. Animals were divided into two groups: Young (3-8 years) and aged (11-18 years). They were clinically healthy, and not obese. Plasma adiponectin (ADN) concentrations in aged horses were significantly lower than those in young horses (mean±SE, 6.5±1.3 μg mL-1 vs, 10.9±1.7 μg mL-1, Mann-Whitney U test, respectively; P=0.0233). Plasma non-esterified fatty acid levels and Insulin and malondialdehyde concentrations in aged group tended to increase compared to those in young group although there were not significant differences statistically. In aged group, malate dehydrogenase/lactate dehydrogenase (M/L) ratio, which is considered an energy metabolic indicator, did not change significantly compared to that in young group. Present data suggest that aging may negatively affect nutrition metabolism, but not induce remarkable changes in M/L ratio in riding horses.

Materials obtained by the immobilization of 12-tungstophosphoric acid (PTA) on silica using the method of impregnation with excess solution in distinct solvents (aqueous HCl, methanol:H2O, and acetonitrile) were evaluated for use as catalysts in the methyl esterification of stearic acid. Optimum conditions were established for the impregnation of 0.5 g (w/w) of PTA on amorphous silica, under stirring at 150 rpm for 24 h, using 20 mL of 0.1 mol L-1 HCl as the solvent. After calcination at 200 ºC, high conversions were obtained under mild reaction conditions, resulting in high turnover numbers. The catalyst was evaluated in ten catalytic cycles of use, where the activity was reduced only slightly, attesting its stability and the possibility to apply it to industrial production of methylesters.

Unoccupied and occupied electronic structures of an L-cysteine film have been studied by absorption and resonant photoelectron spectroscopies. Core absorptions at S-L, C-K, N-K, and O-K levels indicate that the lower unoccupied states are predominantly composed of oxygen-2p, carbon-2p, and sulfur-4s+3d orbitals, while higher unoccupied states may be attributed dominantly to nitrogen-np (n ≥ 3), oxygen-np (n ≥ 3), and sulfur-ns+md (n ≥ 4, m ≥ 3) orbitals. Resonant photoelectron spectra at S-L23 and O-K levels indicate that the highest occupied state is originated from sulfur-3sp orbitals, while oxygen-2sp orbitals contribute to the deeper valence states. The delocalization lifetimes of the oxygen-1s and sulfur-2p excited states are estimated from a core-hole clock method to be about 9 ± 1 and 125 ± 25 fs, respectively.

Two amides, piperovatine and isopiperlonguminine, were isolated from the roots of Ottonia martiana Miq., a herbaceous shrub commonly used in folk medicine in the treatment of toothache. The crude extract (CE) and isolated compounds were submitted to bioautography and allelopathic assay. The bioautograms allowed the detection of compounds with antibacterial activity and the identification of the bioactive substance piperovatine. The CE and amides exhibited an allelopathic effect on Lactuca sativa (lettuce) seedling growth but did not affect the seeds' germinability.

A clonal propagation method by node culture of perilla (Perilla frutescens L. Britton) was investigated. Nodes were plated on solidified 1/2 MS medium with BA and optimum shoot elongation and propagation was obtained at BA 0.05 and 0.1 mg l-1. Cryopreservation using an aluminum cryo-plate was successfully applied to in vitro-grown perilla shoot tips. Excised shoot tips from nodes were precultured on 1/2 MS medium with 0.3 M sucrose and embedded on an aluminum cryo-plate with alginate gel. The cryo-plate with shoot tips was osmo-protected with LS solution and dehydrated in PVS2 for 20 min at 25°C prior to immersion into liquid nitrogen. The recovery growth after cryopreservation was found to be about 80%. This new V-Cryo-plate method has many advantages and may facilitate the cryo-storage of other medicinal plants.

Com finalidade de orientar e oferecer subsídios para a conduta diagnóstica e terapêutica em diferentes situações dentro das doenças cerebrovasculares, a Sociedade Brasileira de Doenças Cerebrovasculares (SBDCV) constituiu um comitê composto por neurologistas de diferentes áreas do Brasil que emitiram um parecer, denominado "Opinião Nacional", redigido nos moldes dos consensos. O presente artigo analisa a "neuroproteção no acidente vascular cerebral" discutindo o nível de evidência para o uso de drogas de potencial ação neuroprotetora e ensaios clínicos em andamento.The Brazilian Stroke Society constituted a committee composed by specialists from different areas of Brazil that emitted a viewpoint called "National Opinion", written similar to the consensus pattern. The study purpose is to guide and offer subsidies for diagnosis and therapeutical plans for different situations in cerebrovascular diseases. The current article analyses "neuroprotective agents in stroke", discussing the level of evidence for the use of potential neuroprotective drugs and ongoing clinical trials.

Creutzfeldt-Jakob disease (CJD) is a transmissible disease of the nervous system causatively related to the presence of an abnormal prion protein, with dementia, myoclonic jerks, and periodic EEG activity. Fourteen patients (7 females and 7 males) ranging from 26 to 76 years of age (median 59 years) were evaluated between 1974 and 1995 at the Neurologic Clinic of São Paulo University School of Medicine. The average duration of the disease was 12 months (3.5 - 34 months). Early clinical findings were: behaviour changes in 7 patients, dementia in 4, visual disturbances in 4, vertigo in 2, tremor in 9, and dystonia in one. Advanced symptoms were dementia and myoclonus in all patients. Pyramidal tract dysfunction was found in 6, cerebellar ataxia in 2, seizures in 3, nystagmus and vertigo in 4, and peripheral nervous system involvement in 2. Atypical clinical forms were found in 5 patients. Periodic EEG activity was found in 10 patients. Cerebrospinal fluid evaluation showed pleocytosis in 1 patient, higher protein content in 2, and higher gamma globulin level in 2. In 10 patients anatomopathological evidence in the central nervous system confirmed the clinical diagnosis by presenting with status spongiosus. All except one patient presented with the sporadic form of the disease.As encefalopatias espongiformes humanas ou doenças priônicas são um grupo de doenças rapidamente progressivas caracterizadas por déficit cognitivo, ataxia, mioclonia e manifestações visuais, piramidais e extrapiramidais. A doença de Creutzfeldt-Jakob (DCT) pode apresentar forma iatrogênica, genética e esporádica. Os autores apresentam 14 pacientes com DCJ forma esporádica e um com forma familial, acompanhados na Disciplina de Neurologia Clínica da FMUSP, no período de 1974 a 1995. Sete eram do sexo feminino e 7 do sexo masculino, com idade variando de 26 a 76 anos (média de 59 anos). As manifestações neurológicas iniciais foram distúrbio do comportamento em 7, demência em 4, deficiência visual em 4, vertigens em 2, tremor em 9 e distonia em um paciente. Posteriormente, demência e mioclonias ocorreram em todos os pacientes. Foram encontrados: disfunção do trato piramidal em 6, vertigens em 4, convulsões em 3, ataxia cerebelar em 2, distúrbio do sistema nervoso periférico em 2. A forma atípica da doença ocorreu em 5 pacientes. Atividade periódica ao eletroencefalograma ocorreu em 10 pacientes. O líquido cefalorraquidiano mostrou pleocitose em 1, hiperproteinorraquia em 2 e hipergamaglobulinorraquia em 2. O estudo anátomo-patológico do sistema nervoso central, feito em 10, revelou alterações vacuolares do neurópilo em todos os pacientes.

To assess the possible role of altered hepatic processing of free fatty acids in dietary sucrose-induced accumulation of triglyceride in the liver and blood plasma, livers from rats fed commercial laboratory stock and high sucrose diets were perfused both with and without oleic acid substrate. Consumption of the sucrose diet exerted a multiplicity of effects on oleic acid metabolism, characterized by decreased conversion to both ketone bodies and carbon dioxide, increased esterification into liver triglyceride, and increased secretion in triglyceride-rich lipoproteins. During the infusion of oleic acid, livers from sucrose-fed rats also exhibited decreased ketogenesis, and increased secretion of triglyceride from endogenous sources. Since oleic acid uptake from the perfusion medium was identical in both groups, the observed effects of sucrose feeding are ascribed to altered rates of intracellular metabolic processes. Mass and radiochemical analyses of perfusate ketone bodies and triglycerides were indicative of greater mobilization of triglycerides from hepatocellular lipid droplets in the livers from sucrose-fed rats. These livers contained more triglyceride and secreted more triglyceride even in the absence of infused oleic acid. In summary, the sucrose-rich diet increased the esterification:oxidation ratio of intracellular free fatty acids derived from both the circulation and endogenous sources within the hepatocyte. In response, secretion of triglyceride-rich lipoproteins by the liver and deposition of triglyceride within the liver were promoted. It is concluded that alterations in the processing of free fatty acids by the liver contribute significantly to the liver and plasma triglyceride accumulation following sucrose consumption.