Effect of solvent hydration and temperature in the deacidification process of sunflower oil using ethanol

This work presents liquid-liquid experimental data for systems composed of sunflower seed oil, ethanol and water from 10 to 60 degrees C. The influence of process variables (temperature (T) and water concentration in the solvent (W)) on both the solvent content present in the raffinate (S(RP)) and extract (S(EP)) phases and the partition of free fatty acids (k(2)) was evaluated using the response surface methodology, where flash calculations were performed for each trial using the UNIQUAC equation. Water content in the solvent was the most important factor on the responses of S(EP) and k(2). Additionally, statistical analysis showed that the S(RP) was predominantly affected by temperature factor for low water content in the solvent. (c) 2009 Elsevier Ltd. All rights reserved.

Characterization of Metal and Trace Element Contents of Particulate Matter (PM10) Emitted by Vehicles Running on Brazilian FuelsHydrated Ethanol and Gasoline with 22% of Anhydrous Ethanol

Emission of fine particles by mobile sources has been a matter of great concern due to its potential risk both to human health and the environment. Although there is no evidence that one sole component may be responsible for the adverse health outcomes, it is postulated that the metal particle content is one of the most important factors, mainly in relation to oxidative stress. Data concerning the amount and type of metal particles emitted by automotive vehicles using Brazilian fuels are limited. The aim of this study was to identify inhalable particles (PM10) and their trace metal content in two light-duty vehicles where one was fueled with ethanol while the other was fueled with gasoline mixed with 22% of anhydrous ethanol (gasohol); these engines were tested on a chassis dynamometer. The elementary composition of the samples was evaluated by the particle-induced x-ray emission technique. The experiment showed that total emission factors ranged from 2.5 to 11.8 mg/km in the gasohol vehicle, and from 1.2 to 3 mg/km in the ethanol vehicle. The majority of particles emitted were in the fine fraction (PM2.5), in which Al, Si, Ca, and Fe corresponded to 80% of the total weight. PM10 emissions from the ethanol vehicle were about threefold lower than those of gasohol. The elevated amount of fine particulate matter is an aggravating factor, considering that these particles, and consequently associated metals, readily penetrate deeply into the respiratory tract, producing damage to lungs and other tissues.

Desiccation tolerance in Pleurostima purpurea (Velloziaceae)

Previous works suggested that Pleurostima purpurea (Velloziaceae-Barbacenioideae) shows a remarkable capacity to endure desiccation of its vegetative tissues. P. purpurea occurs in monocotyledons mats on soil islands in the Pao de Acucar (Sugar Loaf) one of the most recognizable rock outcrops of the world, in Rio de Janeiro, southeastern Brazil. Mats of P. purpurea occur in cliffs by the sea some meters above the tidal zone. Although living in rock outcrops almost devoid of any soil cover, P. purpurea seems to occur preferably on less exposed rock faces and slightly shady sites. Usually, less extreme adaptations to drought would be expected in plants with the habitat preference of P. purpurea. Relying on this observation, we argue if a combination of different strategies of dealing with low water availability can be found in P. purpurea as on other desiccation tolerant angiosperms. This study aims to examine the occurrence of desiccation tolerant behavior in P. purpurea together with the expression of drought avoidance mechanisms during dehydration progression. For this, it was analyzed the gas exchanges, leaf pigments and relative leaf water content during desiccation and rehydration of cultivated mature individuals. P. purpurea behaved like typical drought avoiders under moderated drought condition with stomatal closure occurring around a relative leaf water content up to 90%. During this process, it was observed a delay in the leaf relative water content (RWC(leaf)) decrease comparing to the plant-soil relative water content (RWC(plant-soil)). As soil dehydration worsened, gas exchanges restrictions progressed until a lack of activity which characterizes anabiosis. The loss of chlorophyll occurs before the end of total dehydration, characterizing the presence of poikilochlorophylly. The chlorophyll degradation follows the RWC(leaf) decrease, which achieved the minimum average value of 17% without incurring in leaf abscission. The chlorophyll re-synthesis seems to start well after the full rehydration of the leaf. During all of this process, carotenoid content remained stable. These results are coherent with a combination of drought avoidance and desiccation tolerance in P. purpurea which seems to be coherent with the amplitude of water availability in the rock outcrop habitat where it occurs, suggesting that the periods of water availability are sufficiently long for the success of the costly desiccation tolerant behavior but too short to make a typical drought avoider species win the competition for exploring the rock outcrop substrate where P. purpurea occurs.

The matrix-tolerance hypothesis: an empirical test with frogs in the Atlantic Forest

The matrix-tolerance hypothesis suggests that the most abundant species in the inter-habitat matrix would be less vulnerable to their habitat fragmentation. This model was tested with leaf-litter frogs in the Atlantic Forest where the fragmentation process is older and more severe than in the Amazon, where the model was first developed. Frog abundance data from the agricultural matrix, forest fragments and continuous forest localities were used. We found an expected negative correlation between the abundance of frogs in the matrix and their vulnerability to fragmentation, however, results varied with fragment size and species traits. Smaller fragments exhibited stronger matrix-vulnerability correlation than intermediate fragments, while no significant relation was observed for large fragments. Moreover, some species that avoid the matrix were not sensitive to a decrease in the patch size, and the opposite was also true, indicating significant differences with that expected from the model. Most of the species that use the matrix were forest species with aquatic larvae development, but those species do not necessarily respond to fragmentation or fragment size, and thus affect more intensively the strengthen of the expected relationship. Therefore, the main relationship expected by the matrix-tolerance hypothesis was observed in the Atlantic Forest; however we noted that the prediction of this hypothesis can be substantially affected by the size of the fragments, and by species traits. We propose that matrix-tolerance model should be broadened to become a more effective model, including other patch characteristics, particularly fragment size, and individual species traits (e. g., reproductive mode and habitat preference).

Ethanol-induced sensitization depends preferentially on D(1) rather than D(2) dopamine receptors

Behavioral sensitization, defined as a progressive increase in the locomotor stimulant effects elicited by repeated exposure to drugs of abuse, has been used as an animal model for drug craving in humans. The mesoaccumbens dopaminergic system has been proposed to be critically involved in this phenomenon; however, few studies have been designed to systematically investigate the effects of dopaminergic antagonists on development and expression of behavioral sensitization to ethanol in Swiss mice. We first tested the effects of D(1) antagonist SCH-23390 (0-0.03 mg/kg) or D(2) antagonist Sulpiride (0-30 mg/kg) on the locomotor responses to an acute injection of ethanol (2.0 g/kg). Results showed that all tested doses of the antagonists were effective in blocking ethanol`s stimulant effects. In another set of experiments, mice were pretreated intraperitoneally with SCH-23390 (0.01 mg/kg) or Sulpiride (10 mg/kg) 30 min before saline or ethanol injection, for 21 days. Locomotor activity was measured weekly for 20 min. Four days following this pretreatment, all mice were challenged with ethanol. Both antagonists attenuated the development of ethanol sensitization, but only SCH-23390 blocked the expression of ethanol sensitization according to this protocol. When we tested a single dose (30 min before tests) of either antagonist in mice treated chronically with ethanol, both antagonists attenuated ethanol-induced effects. The present findings demonstrate that the concomitant administration of ethanol with D(1) but not D(2) antagonist prevented the expression of ethanol sensitization, suggesting that the neuroadaptations underlying ethanol behavioral sensitization depend preferentially on D(1) receptor actions. (C) 2010 Elsevier Inc. All rights reserved.

Environmental modulation of ethanol-induced locomotor activity: Correlation with neuronal activity in distinct brain regions of adolescent and adult Swiss mice

Drug abuse is a concerning health problem in adults and has been recognized as a major problem in adolescents. induction of immediate-early genes (IEG), such as c-Fos or Egr-1, is used to identify brain areas that become activated in response to various stimuli, including addictive drugs. It is known that the environment can alter the response to drugs of abuse. Accordingly, environmental cues may trigger drug-seeking behavior when the drug is repeatedly administered in a given environment. The goal of this study was first to examine for age differences in context-dependent sensitization and then evaluate IEG expression in different brain regions. For this, groups of mice received i.p. ethanol (2.0 g/kg) or saline in the test apparatus, while other groups received the solutions in the home cage, for 15 days. One week after this treatment phase, mice were challenged with ethanol injection. Acutely, ethanol increased both locomotor activity and IEG expression in different brain regions, indistinctly, in adolescent and adult mice. However, adults exhibited a typical context-dependent behavioral sensitization following repeated ethanol treatment, while adolescent mice presented gradually smaller locomotion across treatment, when ethanol was administered in a paired regimen with environment. Conversely, ethanol-treated adolescents expressed context-independent behavioral sensitization. Overall, repeated ethanol administration desensitized IEG expression in both adolescent and adult mice, but this effect was greatest in the nucleus accumbens and prefrontal cortex of adolescents treated in the context-dependent paradigm. These results suggest developmental differences in the sensitivity to the conditioned and unconditioned locomotor effects of ethanol. (C) 2008 Elsevier B.V. All rights reserved.

Ablation of primary afferent neurons by neonatal capsaicin treatment reduces the susceptibility of the portal hypertensive gastric mucosa to ethanol-induced injury in cirrhotic rats

Primary sensory afferent neurons modulate the hyperdynamic circulation in Cirrhotic rats with portal hypertension.The stomach of cirrhotic rats is prone to damage induced by ethanol, a phenomenon associated with reduced gastric hyperemic response to acid-back diffusion. The aim of this study was to examine the impact of ablation of capsaicin-sensitive neurons and the tachykinin NK(1) receptor antagonist A5330 on the susceptibility of the portal hypertensive gastric mucosa, to ethanol-induced injury and its effects on gastric cyclooxygenase (COX) and nitric oxide synthase (NOS) mRNA expression. Capsaicin was administered to neonatal, male, Wistar rats and the animals were allowed to grow. Cirrhosis was then induced by bile duct ligation in adult rats while controls had sham operation. Ethanol-induced gastric damage was assessed using ex vivo gastric chamber experiments. Gastric blood flow was measured as well as COX/NOS mRNA expression. Topical application of ethanol produced significant gastric damage in cirrhotic rats compared to controls, which was reversed in capsaicin- and A5330-treated animals. Mean arterial and portal pressure was normalized in capsaicin-treated cirrhotic rats. Capsaicin and A5330 administration restored gastric blood flow responses to topical application of ethanol followed by acid in cirrhotic rats. Differential COX and NOS mRNA expression was noted in bile duct ligated rats relative to controls. Capsaicin treatment significantly modified gastric eNOS/iNOS/COX-2 mRNA expression in cirrhotic rats. Capsaicin-sensitive neurons modulate the susceptibility of the portal hypertensive gastric mucosa to injury induced by ethanol via tachykinin NK(1) receptors and signalling of prostaglandin and NO production/release. (c) 2008 Elsevier B.V. All rights reserved.

It takes guts for tolerance: The phenomenon of oral tolerance and the regulation of autoimmune response

The intestinal tract is a peculiar environment due to its constant contact with the microbiota agents, food antigens and other molecules. Such exposure requires the establishment of important regulatory mechanisms in order to avoid inflammatory response and self aggression. In this context, the GALT plays a very relevant role due to the presence of several different cellular populations which are the main players in this phenomenon. Moreover, it was described a while ago that the oral ingestion of a given molecule is able to induce systemic tolerance to the same molecule when it is used as an immunogen by parenteral route, known as oral tolerance. This observation led researches to use these mechanisms to induce tolerance against cognate antigens of different autoimmune diseases. In this context, in this review we focused on several tolerance inducing mechanisms which are relevant not only for the maintenance of intestinal tract but also for the suppression of T effector cells, such as Th1, Th2 and the newly described Th17 cells. To name a few, CD103(+) dendritic cells, Tr1 cells derived IL-10 secretion, Foxp3 conversion and CD4(+)LAP(+) regulatory cells induction are among the recently described features of the tolerogenic environment of the intestinal tract. (C) 2009 Elsevier B.V. All rights reserved.

Ethanol consumption and pineal melatonin daily profile in rats

It is well known that melatonin participates in the regulation of many important physiological functions such as sleep-wakefulness cycle, motor coordination and neural plasticity, and cognition. However, as there are contradictory results regarding the melatonin production diurnal profile under alcohol consumption, the aim of this paper was to study the phenomenology and mechanisms of the putative modifications on the daily profile of melatonin production in rats submitted to chronic alcohol intake. The present results show that rats receiving 10% ethanol in drinking water for 35 days display an altered daily profile of melatonin production, with a phase delay and a reduction in the nocturnal peak. This can be partially explained by a loss of the daily rhythm and the 25% reduction in tryptophan hydroxylase activity and, mainly, by a phase delay in arylalkylamine N-acetyltransferase gene expression and a 70% reduction in its peak activity. Upstream in the melatonin synthesis pathway, the results showed that noradrenergic signaling is impaired as well, with a decrease in beta 1 and alpha 1 adrenergic receptors` mRNA contents and in vitro sustained loss of noradrenergic-stimulated melatonin production by glands from alcohol-treated rats. Together, these results confirm the alterations in the daily melatonin profile of alcoholic rats and suggest the possible mechanisms for the observed melatonin synthesis modification.

The potential for first-generation ethanol production from sugarcane

Ethanol production from sugarcane, mainly in Brazil, on the basis of first-generation technology (22.5 billion liters, in 2007/2008 season, in 3.4 million hectares) replaces 1% of the gasoline used in the world today and is highly competitive in economic terms with ethanol produced from other crops in the USA and Europe. In this paper we discuss the potential for sugarcane ethanol expansion from two angles: (1) productivity gains which would allow greater production in the same area and (2) geographical expansion to larger areas. The potential of first-generation technology for the production of ethanol from sugarcane is far from being exhausted. There are gains in productivity of approximately a factor of two from genetically modified varieties and a geographical expansion by a factor of ten of the present level of production in many sugar-producing countries. The replacement of 10% of the gasoline used in the world by ethanol from sugarcane seems possible before second-generation technology reaches technological maturity and possibly economic competitiveness. (C) 2009 Society of Chemical Industry and John Wiley & Sons, Ltd

Historical carbon budget of the brazilian ethanol program

This work models the carbon neutralization capacity of Brazil`s ethanol program since 1975. In addition to biofuel, we also assessed the mitigation potential of other energy products, such as, bioelectricity, and CO(2) emissions captured during fermentation of sugar cane`s juice. Finally, we projected the neutralization capacity of sugar cane`s bio-energy system over the next 32 years. The balance between several carbon stocks and flows was considered in the model, including the effects of land-use change. Our results show that the neutralization of the carbon released due to land-use change was attained only in 1992, and the maximum mitigation potential of the sugar cane sector was 128 tonnes Of CO(2) per ha in 2006. An ideal reconstitution of the deployment of the sugar cane sector, including the full exploitation of bio-electricity`s potential, plus the capture Of CO(2) released during fermentation, shows that the neutralization of land-use change emissions would have been achieved in 1988, and its mitigation potential would have been 390 tCO(2)/ha. Finally, forecasts of the sector up to 2039 shows that the mitigation potential in 2039 corresponds to 836 tCO(2)/ha, which corresponds to 5.51 kg Of CO(2) per liter of ethanol produced, or 55% above the negative emission level. (C) 2009 Elsevier Ltd. All rights reserved.

Characterization and spectroscopic analysis of phenol-ethanol hydrogen bonded clusters

Different hydrogen bonded clusters involving phenol and ethanol are studied theoretically using MP2/aug-cc-pVDZ. Nine different 1: 1 clusters are obtained and analyzed according to their stability and spectroscopic properties. Different isomeric forms of ethanol are considered. Attention is also devoted to the spectral shift of the characteristic pi -> pi* transition of phenol. Using TDHF, CIS, CIS(D) and TDB3LYP in aug-cc-pVDZ basis set, all results agree that a red shift is obtained when phenol is the hydrogen donor and a blue shift is obtained in the opposite case. These results are used to rationalize the red shift observed for phenol in liquid ethanol. (C) 2010 Elsevier B.V. All rights reserved.

Calculations of vibrational frequencies, Raman activities and degrees of depolarization for complexes involving water, methanol and ethanol

Raman activities and degrees of depolarization are reported for 14 complexes involving methanol, ethanol and water using the MP2/aug-cc-pVDZ model. For ethanol both trans and gauche isomers are considered. The red-shifts of the OH stretching and the blue shifts of the bending tau(CO-OH) mode were analyzed for the proton-donor molecules upon hydrogen bond. The shift of the nu(CO) stretching mode of the alcohol molecules are also analyzed and found to be specific giving characterization of the amphoteric relation, being positive for the proton-acceptor and negative for the proton-donor molecule. (c) 2008 Elsevier B.V. All rights reserved.

Immobilization of Alcohol Dehydrogenase in Phospholipid Langmuir-Blodgett Films To Detect Ethanol

Enzyme immobilization in nanostructured films may be useful for a number of biomimetic systems, particularly if suitable matrixes are identified. Here we show that alcohol dehydrogenase (ADH) has high affinity toward a negatively charged phospholipid, dimyristoylphosphatidic acid (DMPA), which forms a Langmuir monolayer at an air-water interface. Incorporation of ADH into the DMPA monolayer was monitored with Surface pressure measurements; and polarization-modulation infrared reflection absorption spectroscopy, with the alpha-helices from ADH being mainly oriented parallel to the water surface. ADH remained at the interface even at high surface pressures, thus allowing deposition of Langmuir-Blodgett (LB) films from the DMPA-ADH film. Indeed, interaction with DMPA enhances the transfer of ADH, where the mass transferred onto a solid support increased from 134 ng for ADH on a Gibbs monolayer to 178 ng for an LB film with DMPA. With fluorescence spectroscopy it was possible to confirm that the ADH structure was preserved even after one month of the LB deposition. ADH-containing films deposited onto gold-interdigitated electrodes were employed in a sensor array capable of detecting ethanol at concentrations down to 10 ppb (in volume), using impedance spectroscopy as the method of detection.

Dendrimer-assisted immobilization of alcohol dehydrogenase in nanostructured films for biosensing: Ethanol detection using electrical capacitance measurements

The selective determination of alcohol molecules either in aqueous solutions or in vapor phase is of great importance for several technological areas. In the last years, a number of researchers have reported the fabrication of highly sensitive sensors for ethanol detection, based upon specific enzymatic reactions occurring at the surface of enzyme-containing electrodes. In this study, the enzyme alcohol dehydrogenase (ADH) was immobilized in a layer-by-layer fashion onto Au-interdigitated electrodes (IDEs), in conjunction with layers of PAMAM dendrimers. The immobilization process was followed in Teal time using quartz crystal microbalance (QCM), indicating that an average mass of 52.1 ng of ADH was adsorbed at each deposition step. Detection was carried out using a novel strategy entirely based upon electrical capacitance measurements, through which ethanol could be detected at concentrations of 1 part per million by volume (ppmv). (C) 2007 Elsevier B.V. All rights reserved.