Morphological study of Sr2CeO4 blue phosphor with fine particles

Morphological and spectroscopic studies of Sr2CeO4 blue phosphor in the form of fine particles prepared from a powdered multi-component precursor, via a combustion method, are reported. Samples were also prepared through a solid-state reaction and from a polymeric precursor for comparison. Citric acid or glycine as fuels in the combustion method lead to a mixture which is heated at 950 ºC for 4 h, resulting in spheroidal particles with a diameter between 250-550 nm. Samples from the polymeric precursor result in spheroidal particles (350-550 nm) and from the solid-state reaction in irregular particles (~ 5 mum). Therefore, the combustion method is adequate for preparation of Sr2CeO4 in the form of spherical fine particles.

Amyloid Beta Precursor Protein: Proper Credit for the Basic Biochemical Properties of the Most Studied Protein in the 21st Century

The amyloid precursor protein (APP) is mainly known for being the precursor of the ß-amyloid peptide, which accumulates in plaques found in the brain of Alzheimer's disease patients. Expression in different tissues and the degree of sequence identity among mammals indicate an essential and non-tissue specific physiological function. APP is anchored to the membrane and displays a single C-terminal intracellular domain and a longer N-terminal extracellular domain. The basic biochemical properties and the scattered data on research, not related to production of beta-amyloid peptide, suggest that the protein and the molecules resulting from APP proteolytic cleavage may act as adhesion factors, enzymes, hormones/neurotransmitters and/or protease inhibitors. APP deserves to be known for its quite notable properties and its physiological role(s).

Efeito do cromo nas propriedades catalíticas da MCM-41

The effect of chromium on the catalytic properties of MCM-41 was evaluated in order to develop new catalysts for the trimethylbenzene transalkylation with benzene to produce ethylbenzene, a high-value aromatic in the industry. It was found that chromium decreases the specific surface area but increases the acidity, turning MCM-41 into an active and selective catalyst for ethylbenzene and toluene production. The coke produced on the catalyst is hydrogenated and mainly located outside the pores and thus can be easily removed. The catalyst is more active and selective than mordenite, a commercial catalyst, and thus more promising for commercial applications.

Aplicação da tecnologia de eletrofloculação na recuperação do corante índigo blue a partir de efluentes industriais

The indigo blue dye is widely used in the textile industry. When discarded, besides polluting the environment, it affects the appearance and transparency of aquatic bodies, causing damage to flora and fauna. The removal of this dye from industrial effluents is difficult due to its resistance towards degradation. This work proposes the recovery of indigo blue by electroflocculation, as a subsidy for the treatment of effluents from the jeans industry.

A mechanistic approach to methylene blue sorption on two vegetable wastes: Cork bark and grape stalks

Two vegetable wastes, cork bark and grape stalks, were investigated for the removal of methylene blue from aqueous solution. The effects of contact time, dye concentration, pH, and temperature on sorption were studied relative to adsorption on a commercially-activated carbon. The highest adsorption yield was obtained within the pH range 5 to 10 for grape stalks and 7 to 10 for cork bark. The sorption kinetics of dye onto activated carbon and grape stalks was very fast. Kinetics data were fitted to the pseudo-first and second order kinetic equations, and the values of the pseudo-second-order initial rate constants were found to be 1.69 mg g-1 min-1 for activated carbon, 2.24 mg g-1 min-1 for grape stalks, and 0.90 mg g-1 min-1 for cork bark. Langmuir maximum sorption capacities for activated carbon, grape stalks, and cork bark for methylene blue estimated by the Orthogonal Distance Regression method (ODR) were 157.5 mg g-1, 105.6 mg g-1, and 30.52 mg g-1, respectively. FTIR spectra indicated that carboxylic groups and lignin play a significant role in the sorption of methylene blue. Electrostatic forces, n-p interactions, cation-p, and p-p stacking interactions contribute to methylene blue sorption onto grape stalks and cork bark. Grape stalks can be considered an efficient biosorbent and as a viable alternative to activated carbon and ion-exchange resins for the removal of methylene blue

A novel method for fast enrichment and monitoring of hexavalent and trivalent chromium at the ppt level with modified silica MCM-41 and its determination by inductively coupled plasma optical emission spectrometry

Chromium(III) at the ng L-1 level was extracted using partially silylated MCM-41 modified by a tetraazamacrocyclic compound (TAMC) and determined by inductively coupled plasma optical emision spectrometry (ICP OES). The extraction time and efficiency, pH and flow rate, type and minimum amount of stripping acid, and break- through volume were investigated. The method's enrichment factor and detection limit are 300 and 45.5 pg mL-1, respectively. The maximum capacity of the 10 mg of modified silylated MCM-41 was found to be 400.5±4.7 µg for Cr(III). The method was applied to the determination of Cr(III) and Cr(VI) in the wastewater of the chromium electroplating industry and in environmental and biological samples (black tea, hot and black pepper).

Counteracting incentive sensitization in severe alcohol dependence using deep brain stimulation of the nucleus accumbens: clinical and basic science aspects

The ventral striatum / nucleus accumbens has been implicated in the craving for drugs and alcohol which is a major reason for relapse of addicted people. Craving might be induced by drug-related cues. This suggests that disruption of craving-related neural activity in the nucleus accumbens may significantly reduce craving in alcohol-dependent patients. Here we report on preliminary clinical and neurophysiological evidence in three male patients who were treated with high frequency deep brain stimulation of the nucleus accumbens bilaterally. All three had been alcohol dependent for many years, unable to abstain from drinking, and had experienced repeated relapses prior to the stimulation. After the operation, craving was greatly reduced and all three patients were able to abstain from drinking for extended periods of time. Immediately after the operation but prior to connection of the stimulation electrodes to the stimulator, local field potentials were obtained from the externalized cables in two patients while they performed cognitive tasks addressing action monitoring and incentive salience of drug related cues. LFPs in the action monitoring task provided further evidence for a role of the nucleus accumbens in goal-directed behaviors. Importantly, alcohol related cue stimuli in the incentive salience task modulated LFPs even though these cues were presented outside of the attentional focus. This implies that cue-related craving involves the nucleus accumbens and is highly automatic.

Uso do Blue Rayon para extração/concentração de compostos policíclicos em amostras ambientais

This is a review about the use of Blue rayon in the extraction and concentration of environmental contaminants in the aquatic environment. Blue rayon is an adsorbent composed of fibers covalently linked with copper phthalocyanine trisulphonate that has the ability to selectively adsorb polycyclic compounds. Blue rayon can be used in situ, in columns or in flasks. This method showed to be efficient in the extraction of important classes of environmental contaminants like the polycyclic aromatic hydrocarbons (PAHs), aromatic amines and phenylbenzotriazoles (PBTAs) and can be an important tool in monitoring studies for the evaluation of water quality.

O pKa de indicadores ácido-base e os efeitos coloidais

An experiment is proposed that can be included in undergraduate courses of chemistry. The subject is the acidity of organic compounds, which are employed as pH indicators, particularly in acid-base titrations. The indicators used are methyl orange, bromophenol blue and bromocresol green in aqueous medium. The influence of colloidal systems on the equilibrium is evaluated by the pKa. The colloids employed are surfactants like sodium dodecyl sulfate, cetyl-trimethylammonium bromide and a polymeric non-ionic F127 (pluronics). The effect of stabilization promoted by the system on the acidic or basic structureof the indicator establishes the action mechanism of the colloid on the pKa values.

Feedback-related Brain Potential Activity Complies with Basic Assumptions of Associative Learning Theory

Feedback-related negativity (FRN) is an ERP component that distinguishes positive from negative feedback. FRN has been hypothesized to be the product of an error signal that may be used to adjust future behavior. In addition, associative learning models assume that the trial-to-trial learning of cueoutcome mappings involves the minimization of an error term. This study evaluated whether FRN is a possible electrophysiological correlate of this error term in a predictive learning task where human subjects were asked to learn different cueoutcome relationships. Specifically, we evaluated the sensitivity of the FRN to the course of learning when different stimuli interact or compete to become a predictor of certain outcomes. Importantly, some of these cues were blocked by more informative or predictive cues (i.e., the blocking effect). Interestingly, the present results show that both learning and blocking affect the amplitude of the FRN component. Furthermore, independent analyses of positive and negative feedback event-related signals showed that the learning effect was restricted to the ERP component elicited by positive feedback. The blocking test showed differences in the FRN magnitude between a predictive and a blocked cue. Overall, the present results show that ERPs that are related to feedback processing correspond to the main predictions of associative learning models. ■

Fenilsilicato dopado com Eu III obtido pelo método sol-gel

In this work, we report the synthesis and the photoluminescence features of a Eu(III)-doped modified silica matrix obtained by the sol-gel method. The matrix was prepared by reaction between tetraethylorthosilicate and phenyltriethoxysilane alkoxide. The hydrolysis occurred using basic catalysis. The solids were treated at 100, 200 and 300 ºC during 4 h and the structure was determined by thermogravimetric analysis (TG/DTG), nuclear magnetic resonance (NMR 29Si and 13C), infrared spectroscopy (IR) and photoluminescence (PL). The PL spectra display the Eu(III) lines characteristic of the ion, 5D0 -> 7F J (J=0, 1, 2, 3, 4), the blue emission as ascribed in the silica matrix. The NMR and TG showed the stability of hybrid silica.

Estudi sobre el perfil de persones grans amb dependència del servei d'ajuda a domicili del Consell Comarcal d'Osona i el tipus de suport formal i informal

The aim of this study is to determine the profile of dependent elderly people users of the home care services (SAD) of the regional council in Osona (Consell Comarcal d´Osona) , and the characteristics of formal and informal types of support they use. Methodology. An observational study of a transversal format has been carried out, with retrospective and descriptive purposes. The target population is 63 people (26 men and 37 women) included in the program of the regional SAD They have a recognized dependence grade approved by the law 39 /2006, December 14th , promoting the individual autonomy and care of elderly people in a dependent situation. The data were collected by social workers of basic social services, first with a home visit and followed by handed out questionnaires, specifically designed for this study, in order to obtain information on socio-demographic characteristics, and the type of support formal and informal. The obtained results on the SAD users are women in a 58.7% and a 41.3 % are men. The 84% of the total sampling are 80 years old and more, being the average age of 85.2 years old. 45% of them are married, 41% are widows and widowers and 14% are single. 54% are rated with severe dependence (grade II), 42.8% with high dependence (grade III). 86% live accompanied. 100% have an informal caregiver and a 95% of the times, the caregiver is a relative who in 73% of the cases the dedication time is permanent. The coverage of the SAD has an average of 4.27 hours per week and per user. The formal services most used are the technical (62%), also the assessment of an occupational therapist at home (57%) and the telecare service in a (56%). Conclusions. The SAD is used primarily for women in an advanced age and severe dependence. The informal assistance structures have an informal caregiver, being a member of the family mostly, living with the dependent, and mainly in a permanent dedication basis. The SAD has a varied intensity in each case. The formal support services complementary to the SAD, are largely used in all cases.

The process of basic training, applied training, maintaining the performance of an observer

In the field of observational methodology the observer is obviously a central figure, and close attention should be paid to the process through which he or she acquires, applies, and maintains the skills required. Basic training in how to apply the operational definitions of categories and the rules for coding, coupled with the opportunity to use the observation instrument in real-life situations, can have a positive effect in terms of the degree of agreement achieved when one evaluates intra- and inter-observer reliability. Several authors, including Arias, Argudo, & Alonso (2009) and Medina and Delgado (1999), have put forward proposals for the process of basic and applied training in this context. Reid y De Master (1982) focuses on the observer's performance and how to maintain the acquired skills, it being argued that periodic checks are needed after initial training because an observer may, over time, become less reliable due to the inherent complexity of category systems. The purpose of this subsequent training is to maintain acceptable levels of observer reliability. Various strategies can be used to this end, including providing feedback about those categories associated with a good reliability index, or offering re-training in how to apply those that yield lower indices. The aim of this study is to develop a performance-based index that is capable of assessing an observer's ability to produce reliable observations in conjunction with other observers.

Characterizing Propionibacterium freudenreichii ssp. shermanii JS and Lactobacillus rhamnosus LC705 as a new probiotic combination: basic properties of JS and pilot in vivo assessment of the combination

Characterizing Propionibacterium freudenreichii ssp. shermanii JS and Lactobacillus rhamnosus LC705 as a new probiotic combination: basic properties of JS and pilot in vivo assessment of the combination Each candidate probiotic strain has to have the documentation for the proper identification with current molecular tools, for the biological properties, for the safety aspects and for the health benefits in human trials if the intention is to apply the strain as health promoting culture in the commercial applications. No generalization based on species properties of an existing probiotic are valid for any novel strain, as strain specific differences appear e.g. in the resistance to GI tract conditions and in health promoting benefits (Madsen, 2006). The strain evaluation based on individual strain specific probiotic characteristics is therefore the first key action for the selection of the new probiotic candidate. The ultimate goal in the selection of the probiotic strain is to provide adequate amounts of active, living cells for the application and to guarantee that the cells are physiologically strong enough to survive and be biologically active in the adverse environmental conditions in the product and in GI tract of the host. The in vivo intervention studies are expensive and time consuming; therefore it is not rational to test all the possible candidates in vivo. Thus, the proper in vitro studies are helping to eliminate strains which are unlikely to perform well in vivo. The aims of this study were to characterize the strains of Propionibacterium freudenreichii ssp. shermanii JS and Lactobacillus rhamnosus LC705, both used for decades as cheese starter cultures, for their technological and possible probiotic functionality applied in a combined culture. The in vitro studies of Propionibacterium freudenreichii ssp. shermanii JS focused on the monitoring of the viability rates during the acid and bile treatments and on the safety aspects such as antibiotic susceptibility and adhesion. The studies with the combination of the strains JS and LC705 administered in fruit juices monitored the survival of the strains JS and LC705 during the GI transit and their effect on gut wellbeing properties measured as relief of constipation. In addition, safety parameters such as side effects and some peripheral immune parameters were assessed. Separately, the combination of P. freudenreichii ssp. shermanii JS and Lactobacillus rhamnosus LC705 was evaluated from the technological point of view as a bioprotective culture in fermented foods and wheat bread applications. In this study, the role ofP. freudenreichii ssp. shermanii JS as a candidate probiotic culture alone and in a combination with L. rhamnosus LC705 was demonstrated. Both strains were transiently recovered in high numbers in fecal samples of healthy adults during the consumption period. The good survival through the GI transit was proven for both strains with a recovery rate from 70 to 80% for the JS strain and from 40 to 60% for the LC705 strain from the daily dose of 10 log10 CFU. The good survival was shown from the consumption of fruit juices which do not provide similar matrix protection for the cells as milk based products. The strain JS did not pose

Saako historiasta selvää? Monikulttuuriset yläkoululaiset historian lähteillä historian taidot motiivien, seurauksien, historian tulkintojen ja lähteiden luotettavuuden arvioinneissa

The research assesses the skills of upper comprehensive school pupils in history. The focus is on locating personal motives, assessing wider reasons hidden in historical sources and evaluating source reliability. The research also questions how a wide use of multiple sources affects pupils’ holistic understanding of historical phenomena. The participants were a multicultural group of pupils. The origins of their cultures can be traced to the Balkan, the Middle East, Asia and Europe. The number of native Finnish speakers and pupils speaking Finnish as their second language was almost equal. The multicultural composition provides opportunities to assess how culturally responsive learning history from sources is. The intercultural approach to learning in a multicultural setting emphasizes equality as a precondition for learning. In order to set assignments at least to some extent match with all participants only those answers were taken into account which were produced by pupils who had studied history for a similar period of time in the Finnish comprehensive school system. Due to the small number of participants (41), the study avoids wide generalizations. Nevertheless, possible cultural blueprints in pupils’ way of thinking are noted. The first test examined the skills of pupils to find motives for emigration. The results showed that for 7th graders finding reasons is not a problematic task. However, the number of reasons noticed and justifications varied. In addition, the way the pupils explained their choices was a distinguishing factor. Some pupils interpreted source material making use of previous knowledge on the issue, while other pupils based their analysis solely on the text handed and did not try to add their own knowledge. Answers were divided into three categories: historical, explanatory and stating. Historical answers combined smoothly previously learned historical knowledge to one’s own source analysis; explanatory answers often ignored a wider frame, although they were effective when explaining e.g. historical concepts. The stating answers only noticed motives from the sources and made no attempts to explain them historically. Was the first test culturally responsive? All pupils representing different cultures tackled the first source exam successfully, but there were some signs of how historical concepts are understood in a slightly different way if the pupil’s personal history has no linkage to the concepts under scrutiny. The second test focused on the history of Native Americans. The test first required pupils to recognize whether short source extracts (5) were written by Indians or Caucasians. Based on what they had already learned from North American history, the pupils did not find it hard to distinguish between the sources. The analysis of multiphase causes and consequences of the disputes between Native Americans and white Americans caused dispersion among pupils. Using two historical sources and combining historical knowledge from both of them simultaneously was cumbersome for many. The explanations of consequences can be divided into two groups: the ones emphasizing short term consequences and those placing emphasis on long term consequences. The short term approach was mainly followed by boys in every group. The girls mainly paid attention to long term consequences. The result suggests that historical knowledge in sources is at least to some extent read through role and gender lenses. The third test required pupils to explain in their own words how the three sources given differed in their account of living conditions in Nazi Germany, which turned out to be demanding for many pupils. The pupils’ stronghold was rather the assessment of source reliability and accounts why the sources approached the same events differently. All participants wrote critical and justified comments on reliability and aspects that might have affected the content of the sources. The pupils felt that the main reasons that affected source reliability were the authors’ ethnic background, nationality and profession. The assessment showed that pupils were well aware that position in a historical situation has an impact on historical accounts, but in certain cases the victim’s account was seen as a historical truth. The account of events by a historian was chosen most often as the most reliable source, but it was often justified leniently with an indication to professionalism rather than with clear ideas of how historians conduct accounts based on sources. In brief, the last source test demonstrates that pupils have a strong idea that the ethnicity or nationalism determines how people explained events of the past. It is also an implication that pupils understand how historical knowledge is interpretative. The results also imply that history can be analyzed from a neutral perspective. One’s own membership in an ethnical or religious group does not automatically mean that a person’s cultural identity excludes historical explanations if something in them contradicts with his or her identity. The second method of extracting knowledge of pupils’ historical thinking was an essay analysis. The analysis shows that an analytical account of complicated political issues, which often include a great number of complicated political concepts, leads more likely to an inconsistent structure in the written work of pupils. The material also demonstrates that pupils have a strong tendency to take a critical stance when assessing history. Historical empathy in particular is shown if history somehow has a linkage to young people, children or minorities. Some topics can also awake strong feelings, especially among pupils with emigrant background, if there is a linkage between one’s own personal history and that of the school; and occasionally a student’s historical experience or thoughts replaced school history. Using sources during history lessons at school seems to have many advantages. It enhances the reasoning skills of pupils and their skills to assess the nature of historical knowledge. Thus one of the main aims and a great benefit of source work is to encourage pupils to express their own ideas and opinions. To conclude, when assessing the skills of adolescents in history - their work with sources, comments on history, historical knowledge and finally their historical thinking - one should be cautious and avoid cut off score evaluations. One purpose of pursuing history with sources is to encourage pupils to think independently, which is a useful tool for further identity construction. The idea that pupils have the right to conduct their own interpretations of history can be partially understood as part of a wider learning process, justification to study history comes from extrinsic reasons. The intrinsic reason is history itself; in order to understand history one should have a basic understanding of history as a specific domain of knowledge. Using sources does not mean that knowing history is of secondary importance. Only a balance between knowing the contextual history, understanding basic key concepts and working with sources is a solid base to improve pupils’ historical understanding.