Análise de Parafinas por APCI-FT-ICR MS : Uma Análise Rápida e Simples na Identificação de Hidrocarbonetos Saturados, Cíclicos e Poliaromáticos

A análise de hidrocarbonetos por técnicas de ionização a pressão atmosférica ou ambiente continua a ser um desafio na espectrometria de massas. Normalmente, a ionização ocorre através de mecanismos de protonação e desprotonação. Para isso, as moléculas de interesse devem apresentar um grupo básico ou ácido que proporcionem a geração de íons [M+H]+ ou [M-H]-. Para superar essa limitação, um método analítico simples, fácil, rápido e poderoso foi desenvolvido com sucesso, adaptado a partir da literatura, para ionizar saturado e insaturado, linear, ramificado, e hidrocarbonetos cíclicos, bem como hidrocarbonetos poliaromáticos e heteroaromáticos presentes em frações de hidrocarbonetos e de misturas de parafina/petróleo bruto utilizando ionização química à pressão atmosférica (APCI), favorecido pela utilização de solventes alifáticos de cadeia curta em um espectrômetro de massas FT-ICR. Entre os reagentes alifáticos estudados, isoctano proporcionou os melhores resultados quando comparado com outros solventes. Além disso, foram estudados outros interferentes do processo de ionização, como concentração da solução injetada e misturas parafina/óleo, que influenciavam desde o perfil dos espectros até as principais classes de compostos identificados. O método torna possível a ionização de hidrocarbonetos pela produção de íons [M -H]+ sem ocorrência de fragmentação.

Morphological, physical and pedogenetic attributes related to water yield in small watersheds in Guarapari/ES, Brazil

Soil characteristics related to the genesis, land use and management are important factors in water dynamics in watersheds. This study evaluated physical, morphological and pedogenetic attributes related to water yield potential in small watersheds in Guarapari, ES, Brazil. The following representative profiles were selected, morphologically described and sampled in area of Atlantic Forest domain: Lithic Udifolists, Oxyaquic Udifluventes, Typic Paleudults, Typic Hapludults, Typic Hapludox, Oxic Dystrudepts and Typic Endoaquents. Samples were collected in the soil profiles for physical analysis. Measurements of field-saturated hydraulic conductivity and soil penetration resistance were perfomed in some profiles, which were under different uses. The Endoaquents of Limão Creek can be considered efficient as temporary water reservoirs. However, the use of artificial drainage tends to reduce this effect. Differential erosion was detected by the sand texture on the surface of the Typic Paleudults due to the low degree of clay flocculation, slope, high resistance to the penetration and low hydraulic conductivity of the Bt horizon, making it necessary to adopt soil management practices to increase the water infiltration. Under pasture, mainly in the cattle trails where the trampling is more intense, there was high resistance to penetration in the superficial layers of the Typic Hapludults. The Typic Hapludox have the greatest potential for water yield in the small watersheds because of its greater extent in the headwaters and their morphological and physical characteristics, which can result in increased aquifer recharge.

The main benefits associated with health and safety management systems certification in Portuguese small and medium enterprises post quality management system certification

The purpose of this study is to characterize how Portuguese Small and Medium Enterprises (SMEs) view the Occupational Health and Safety Management Systems (OHSMSs) certification process, after receiving the Quality Management System (QMS) certification. References were based on the ISO 9001 standard for a QMS and OHSAS 18001 for OHSMS. The method used to evaluate the implemented systems, was by form of questionnaire. Those questioned had to have a certified quality management system, an implemented OHSMS and be a SME. The questionnaire was sent to 300 SMEs; 46 responses were received and validated. Of them, only 12 SMEs had the OHSMS certificate according to OHSAS 18001. Within those 12 companies that participated: 7 SMEs are from the industrial sector; 3 belong to the electricity/telecommunications sector and 2 SMEs are from the trade/services activity sector. The size of the sample was small, but corresponds to Portuguese reality. Moreover, 34 SMEs did not have the OHSMS certificate. The questionnaire requested the main reasons for SMEs to opt for non-certification and it was related with high costs, while the main reasons to certificate were, among others, needed to eliminate or minimize risks to workers. The main benefits that Portuguese SMEs have gained from the referred certifications have been, improved working conditions, ensuring compliance with legislation and better internal communication about risks and hazards. Also presented are the main difficulties in achieving an OHSMS certification including high certification costs, difficulties motivating personnel, difficulties in changing the company’s culture and increased bureaucracy.

Certification and integration of management systems: the experience of Portuguese small and medium enterprises

The purpose of this study was to characterize the situation of Portuguese Small and Medium Enterprises (SMEs) concerning the certification of their Quality Management Systems (QMS), Environmental Management Systems (EMS) and Occupational Health and Safety Management Systems (OHSMS), in their individually form, to identify benefits, drawbacks and difficulties associated with the certification process and to characterize the level of integration that has been achieved. This research was based on a survey carried out by the research team; it was administered to 46 Portuguese SMEs. Our sample comprised 20 firms (43%) from the Trade/Services activity sector, 17 (37%) from the Industrial sector, 5 (11%) from the Electricity/Telecommunications sector and 4 (9%) from the Construction area. All SMEs surveyed were certified according to the ISO 9001 (100%), a quarter of firms were certified according to the ISO 14001 (26.1%) and a few certified by OHSAS 18001 (15.2%). We undertook a multivariate cluster analysis, which enabled grouping variables into homogeneous groups or one or more common characteristics of the SMEs participating in the study. Results show that the main benefits that Portuguese SMEs have gained from the referred certifications have been, among others, an improvement of both their internal organization and external image. We also present the main difficulties in achieving certification. Overall, 7 of the Portuguese SMEs examined indicated that the main benefits of the IMS implementation management included costs reduction, increased employee training and easier compliance of legislation. The respective drawbacks and difficulties are also presented. Finally, we presented the main integrated items in the certified Portuguese SMEs we examined.

Is category management in small supermarkets worth the effort?

Category management (CM) is an important tool to strengthen the relationship between manufacturers and retailers. This process has been associated with large corporate retailers; however, some recent researches show that CM is open to companies of any type or size. This possibility is important in emerging markets, where neighborhood supermarkets are still representative and are often considered an alternative for manufacturers to achieve higher margins compared to big chains. In this context, the aim of this research was to analyze the results of a CM initiative in small neighborhood supermarkets from a manufacturer perspective. Data for the study comes from a food manufacturer in Brazil that implemented a CM process with 180 small retailers. A quantitative analysis was conducted in order to analyze the effect of the program on the food manufacturer' s sales and market share. Our analysis suggests an overall positive effect of the program on both, sales and market share.

Nutritional status of children, inmates of a small institution for homeless children in the capital of the State of S. Paulo, Brazil

Nutritional surveys (food consumption, clinical and biochemichal) were conducted in a small institution for homeless children. Results showed that only 30% of the children presented adequate calorie intake. Most of the children presented adequate protein intake, but almost half consumed less than 2/3 of the calcium RDA considered necessary. Food handling, processing, and distribution also proved inadequate and wastage, high. Skinfold measurement showed up one case of obesity. Furthermore, most of the children presented clinical signs of vitamin A deficiency, mostly skin lesions; while about half presented clinical signs of riboflavin deficiency. Biochemical data showed that 63.6% had deficient plasma levels of vitamin A, none showed abnormal results for riboflavin excretion, four showed packed blood cell volume below normal, and all had normal hemoglobin levels. Stool examinations revealed a high rate of pathogenic protozoa (Hymenolepis nana), in fact, one of the highest in Brazilian literature.

Field effect and light-assisted a-Si:H sensors for detection of ions in solution

In this paper we present an amorphous silicon device that can be used in two operation modes to measure the concentration of ions in solution. While crystalline devices present a higher sensitivity, their amorphous counterpart present a much lower fabrication cost, thus enabling the production of cheap disposable sensors for use, for example, in the food industry. The devices were fabricated on glass substrates by the PECVD technique in the top gate configuration, where the metallic gate is replaced by an electrolytic solution with an immersed Ag/AgCl reference electrode. Silicon nitride is used as gate dielectric enhancing the sensitivity and passivation layer used to avoid leakage and electrochemical reactions. In this article we report on the semiconductor unit, showing that the device can be operated in a light-assisted mode, where changes in the pH produce changes on the measured ac photocurrent. In alternative the device can be operated as a conventional ion selective field effect device where changes in the pH induce changes in the transistor's threshold voltage.

Nutritional factors in milk from Brazilian mothers delivering small for gestational age neonates

The composition of breast milk from brazilian mothers delivering low birthweight infants and its adequacy as a source of nutrients for this group has not yet been fully elucidated. A total of 209 milk samples from 66 women were analysed. The mothers were divided into three groups: G1, mothers delivering term babies of low birthweight (TSGA, n=16); G2, mothers delivering preterm babies of appropriate birthweight (PTAGA, n=20); G3, mothers delivering term babies of appropriate birthweight (TAGA, n=30). The following factors were analysed: osmolarity, total proteins and protein fractions, creamatocrit, sodium, potassium, calcium and magnesium. Milk samples were collected 48 h and 7, 15, 30 and 60 days after delivery. The groups did not differ significantly in terms of osmolarity, total proteins and fractions, creamatocrit, calcium, magnesium or potassium throughout the study period. Sodium levels were higher in all samples from mothers of TSGA infants and in samples from mothers of PTAGA infants on the 7th, 15th and 30th days than in milk from the TAGA group. The authors consider the needs of the low birthweight and TAGA infants and that these high sodium levels may be necessary for growth of low birthweight infants.

Evaluation of the respiratory motion effect in small animal PET images with GATE Monte Carlo simulations

The rapid growth in genetics and molecular biology combined with the development of techniques for genetically engineering small animals has led to increased interest in in vivo small animal imaging. Small animal imaging has been applied frequently to the imaging of small animals (mice and rats), which are ubiquitous in modeling human diseases and testing treatments. The use of PET in small animals allows the use of subjects as their own control, reducing the interanimal variability. This allows performing longitudinal studies on the same animal and improves the accuracy of biological models. However, small animal PET still suffers from several limitations. The amounts of radiotracers needed, limited scanner sensitivity, image resolution and image quantification issues, all could clearly benefit from additional research. Because nuclear medicine imaging deals with radioactive decay, the emission of radiation energy through photons and particles alongside with the detection of these quanta and particles in different materials make Monte Carlo method an important simulation tool in both nuclear medicine research and clinical practice. In order to optimize the quantitative use of PET in clinical practice, data- and image-processing methods are also a field of intense interest and development. The evaluation of such methods often relies on the use of simulated data and images since these offer control of the ground truth. Monte Carlo simulations are widely used for PET simulation since they take into account all the random processes involved in PET imaging, from the emission of the positron to the detection of the photons by the detectors. Simulation techniques have become an importance and indispensable complement to a wide range of problems that could not be addressed by experimental or analytical approaches.

Identificação de compostos que modulam a patogénese da doença de Machado-Joseph em C.elegans: autofagia como alvo terapêutico: identification of small compounds that modulate pathogenesis of Machado-Joseph disease in a C.elegans model: targeting autophagy

A doença de Machado-Joseph (DMJ) ou ataxia espinocerebelosa do tipo 3 (SCA3), conhecida por ser a mais comum das ataxias hereditárias dominantes em todo o mundo, é uma doença neurodegenerativa autossómica dominante que leva a uma grande incapacidade motora, embora sem alterar o intelecto, culminando com a morte do doente. Atualmente não existe nenhum tratamento eficaz para esta doença. A DMJ é resultado de uma alteração genética causada pela expansão de uma sequência poliglutamínica (poliQ), na região C-terminal do gene que codifica a proteína ataxina-3 (ATXN3). Os mecanismos celulares das doenças de poliglutaminas que provocam toxicidade, bem como a função da ATXN3, não são ainda totalmente conhecidos. Neste trabalho, usamos, pela sua simplicidade e potencial genético, um pequeno animal invertebrado, o nemátode C. elegans, com o objetivo de identificar fármacos eficazes para o combate contra a patogénese da DMJ, analisando simultaneamente o seu efeito na agregação da ATXN3 mutante nas células neuronais in vivo e o seu impacto no comportamento motor dos animais. Este pequeno invertebrado proporciona grandes vantagens no estudo dos efeitos tóxicos de proteínas poliQ nos neurónios, uma vez que a transparência das suas 959 células (das quais 302 são neurónios) facilita a deteção de proteínas fluorescentes in vivo. Para além disso, esta espécie tem um ciclo de vida curto, é económica e de fácil manutenção. Neste trabalho testámos no nosso modelo transgénico da DMJ com 130Qs em C.elegans dois compostos potencialmente moduladores da agregação da ATXN3 mutante e da resultante disfunção neurológica, atuando pela via da autofagia. De modo a validar a possível importância terapêutica da ativação da autofagia os compostos candidatos escolhidos foram o Litío e o análogo da Rapamicina CCI-779, testados independentemente e em combinação. A neuroproteção conferida pelo Litío e pelo CCI-779 independentemente sugere que o uso destes fármacos possa ser considerado uma boa estratégia como terapia para a DMJ, a testar em organismos evolutivamente mais próximos do humano. A manipulação da autofagia, segundo vários autores, parece ser benéfica e pode ser a chave para o desenvolvimento de novos tratamentos para várias doenças relacionadas com a agregação proteica e o envelhecimento.

Membrane selectivity versus sensor response in hydrogenated amorphous silicon CHEMFETs using a semi-empirical model

Toxic amides, such as acrylamide, are potentially harmful to Human health, so there is great interest in the fabrication of compact and economical devices to measure their concentration in food products and effluents. The CHEmically Modified Field Effect Transistor (CHEMFET) based onamorphous silicon technology is a candidate for this type of application due to its low fabrication cost. In this article we have used a semi-empirical modelof the device to predict its performance in a solution of interfering ions. The actual semiconductor unit of the sensor was fabricated by the PECVD technique in the top gate configuration. The CHEMFET simulation was performed based on the experimental current voltage curves of the semiconductor unit and on an empirical model of the polymeric membrane. Results presented here are useful for selection and design of CHEMFET membranes and provide an idea of the limitations of the amorphous CHEMFET device. In addition to the economical advantage, the small size of this prototype means it is appropriate for in situ operation and integration in a sensor array.

HIV infection and AIDS in a small municipality in Southeast Brazil

OBJECTIVE: Studies on the aspects of HIV infection in small Brazilian municipalities are invaluable to appropriately design control strategies, better allocate resources, and improve health care services. The objective of the study was to assess the clinical and epidemiological aspects of HIV infection in a small municipality. METHODS: A descriptive study was carried out in Miracema, a small municipality in the northwestern area of the state of Rio de Janeiro, Brazil, between July 1999 and December 2003. All HIV-infected adult patients followed up at the local HIV/AIDS Program were included. Clinical and epidemiologic characteristics were prospectively assessed through standardized questionnaires. RESULTS: A total of 65 adult patients who attended the local HIV/AIDS Program were analyzed. Most (34) were women (male to female ratio: 0.9). An absolute predominance of patients who were born in Miracema or neighboring municipalities (94%), lived in Miracema (90.7%), were single (70.8%), attributed the acquisition of HIV infection to unprotected heterosexual intercourse (72.3%) and had a past history of snorting cocaine (27.7) was found Central nervous system disorders (including five cases of cryptococcal meningitis) and acute pulmonary pneumocystosis-like respiratory failure were major causes of morbidity. Most patients (56.9%) were at presented in advanced stages of HIV infection. CONCLUSIONS: The predominance of patients on advanced stages of HIV infection suggest the existence of a large pool of undiagnosed cases in the community. A major feature of the cohort was an inverted male to female ratio. Further investigations over a broader geographic area are urgently needed for better understanding the clinical and epidemiological characteristics of HIV infection in small Brazilian municipalities and rural areas.

Adaptive mutations in bacteria: high rate and small effects

Evolution by natural selection is driven by the continuous generation of adaptive mutations. We measured the genomic mutation rate that generates beneficial mutations and their effects on fitness in Escherichia coli under conditions in which the effect of competition between lineages carrying different beneficial mutations is minimized. We found a rate on the order of 10–5 per genome per generation, which is 1000 times as high as previous estimates, and a mean selective advantage of 1%. Such a high rate of adaptive evolution has implications for the evolution of antibiotic resistance and pathogenicity.