Approaches to liquid chromatography tandem mass spectrometry assessment of glyphosate residues in wine.

The performance of two different analytical methodologies to investigate the presence of glyphosate (GLY) and aminomethylphosphonic acid (AMPA) residues in wine samples was evaluated. Transformation of compounds in their fluorene-9-methyloxycarbonyl derivatives permitted their separation under reversed-phase liquid chromatography with tandem mass spectrometry (LC-MS/MS) determination. Although the wine matrix severely impaired the efficiency of GLY derivatization, this drawback was solved using a molecularly imprinted sorbent for the previous, selective extraction of GLY and AMPA from wine. Alternatively, the use of a strong anionic exchange, polyvinyl alcohol-based LC column, turned to be the most effective alternative for direct determination of both compounds in diluted wine samples. The chromatographic behavior of this column and the magnitude of matrix effects observed during analysis of diluted wine samples were significantly affected by the composition of the mobile phase. Under final working conditions, this column permitted the separation of AMPA and the fungicide fosetyl (which shows common transitions in tandem MS/MS methods), it improved significantly the sample throughput versus extraction-derivatization-purification method, and it allowed the use of solvent-based calibration standards. Both analytical procedures provided similar limits of quantification (LOQs) for GLY (0.5-1.0 ng mL-1), while the multistep method was 8 times more sensitive to AMPA than the direct procedure. GLY residues stayed above method LOQs in 70% of the processed wines; however, concentrations measured in 95% of positive samples remained 100 times below the maximum residue limit (MRL) set for GLY in vinification grapes.

Assessment of UV combined with free chlorine for removal of valsartan acid from water samples.

Valsartan acid (VALA) is a persistent and mobile pollutant, ubiquitously distributed in the aquatic environment. Herein, we assessed the efficiency of UV/free chlorine for the removal of this pollutant. Degradation experiments were performed using different water samples, considering several pH values and concentrations of inorganic anions. Time-course of VALA was measured by injection of different reaction time aliquots in a liquid chromatography (LC) triple quadrupole (QqQ) mass spectrometry (MS) system, whilst the study of potential transformation products (TPs) was evaluated by LC combined with a hybrid quadrupole time-of-flight (QTOF) MS system. Formation of volatile disinfection by-products (DBPs) was investigated by gas chromatography (GC) with TOF-MS detection. Compared to free chlorine treatment and UV photolysis, the combination of both parameters significantly enhanced the degradability of VALA. At neutral pH, UV/free chlorine was also more effective than UV/H2O2 to remove VALA from spiked water solutions. Three TPs of VALA were tentatively identified by LC-QTOF-MS, although only one was stable in the UV/free chlorine media. As regards volatile DBPs, the formation of chloroform, dichloroacetonitrile, di- and trichloroacetic acid was noticed. The mass yield of DBPs formation from VALA varied from 0.3% (dichloroacetonitrile) to 1.1% (chloroform). The efficiency of UV/free chlorine was first investigated in spiked solutions with increasing complexities: ultrapure, river and treated wastewater. Thereafter, the feasibility of reducing VALA levels in polluted river water was demonstrated.

Assessment of gas chromatography time-of-flight mass spectrometry for the screening of semi-volatile compounds in indoor dust.

Indoor dust contains a complex mixture of anthropogenic and synthetic compounds closely related to dermal and respiratory diseases. Target methods have been developed for the quantification of distinct groups of substances in dust samples; however, the comprehensive characterization of the different species existing in this matrix remains a challenging issue. Herein, we assess the performance of gas chromatography (GC) time-of-flight mass spectrometry (TOF-MS), using electron ionization (EI), for the screening of compounds present in indoor dust. Samples are processed by pressurized-liquid extraction (PLE) before GC-EI-TOF-MS analysis. The study proposes a data mining workflow for the non-target identification of species contained in dust extracts, aided by preliminary comparison with nominal resolution EI-MS spectra in the NIST17 library. The possibilities, and the limitations, of the above approach are discussed and the identities of >75 compounds are confirmed by comparison with authentic standards in dust from indoor environments. Some species, such as indigo, phthalic anhydride, 2,4-toluene di-isocyanate, phthalimide, certain UV absorbers and octyl isothiazolinone, identified in this research, have not been previously considered in target methods dealing with dust analysis. The study also evaluates two different algorithms for the suspected-target screening of dust extracts using a customized library of accurate EI-MS spectra. Finally, a semi-quantitative estimation of the range of concentrations for a group of 44 pollutants in a set of 27 dust samples is provided.

Free chlorine reactions of angiotensin II receptor antagonists: Kinetics study, transformation products elucidation and in-silico ecotoxicity assessment.

Angiotensin II receptor antagonists (ARA II) are widely employed in the treatment of hypertension-related diseases. Because of their partial metabolization and limited biodegradability, these drugs have become ubiquitous pollutants in the aquatic environment, including surface water. This research evaluated the reactivity of the ARA II drugs: irbesartan (IRB), losartan (LOS) telmisartan (TEL) and valsartan (VAL) with free chlorine. Responses of parent compounds and their transformation products (TPs) were followed by liquid chromatography (LC) with quadrupole (Q) time-of-flight (TOF) mass spectrometry. Degradation experiments were carried out using ultrapure and river water samples, adjusted at different pHs and, in some cases, adding a small amount (ng mL-1 level) of bromide salts. Whilst TEL and VAL remained stable in presence of relatively high concentrations of free chlorine (10 mg L-1), IRB and LOS were removed according to a pseudo-first order kinetics model. Considering an initial chlorine concentration of 10 mg L-1, their half-lives varied between 6 and 734 min, depending mostly on the water pH. IRB reacted with free chlorine through hydroxylation processes, with and without molecular cleavage and re-arrangements in the imidazolone ring. Its TPs showed a lower in-silico predicted toxicity than the parent drug. In case of LOS, two major competitive degradation routes were identified. They involved replacement of the methanol group attached to the imidazole cycle by chlorine or bromine, and the cleavage of this cycle with removal of the chlorinated carbon and the nitrogen in alpha position. The TPs generated following the first route are predicted to be more toxic than LOS.

Solvent extraction of organic acids from stillage for its re-use in ethanol production process.

Stillage re-use in the fermentation stage in ethanol production is a technique used for the reduction of water and fermentation nutrients consumption. However, the inhibitory effect on yeast growth of the by-products and feed components that remains in stillage increases with re-use and reduces the number of possible recycles. Several methods such as ultrafiltration, electrodialysis and advanced oxidation processes have been used in stillage treatment prior its re-use in the fermentation stage. Nevertheless, few studies evaluating the effect of solvent extraction as a stillage treatment option have been performed. In this work, the inhibitory effect of serial stillage recycling over ethanol and biomass production was determined, using acetic acid as a monitoring compound during the fermentation and solvent extraction process. Raw palm oil methyl ester showed the highest acetic acid extraction from the aqueous phase, presenting a distribution coefficient of 3.10 for a 1:1 aqueous phase mixture:solvent ratio. Re-using stillage without treatment allowed up to three recycles with an ethanol production of 53.7 +/- 2.0 g L(-1), which was reduced 25% in the fifth recycle. Alternatively, treated stillage allowed up to five recycles with an ethanol final concentration of 54.7 +/- 1.3 g L(- 1). These results show that reduction of acetic acid concentration by an extraction process with raw palm oil methyl ester before re-using stillage improves the number of recycles without a major effect on ethanol production. The proposed process generates a palm oil methyl ester that contains organic acids, among other by-products, that could be used for product recovery and as an alternative fuel.

Estado actual de los sistemas de soporte circulatorio mecánico: State of the art / Circulatory mechanical support. State of the art

Despite advances in medical treatment, the prognosis of advanced heart failure remains poor. The number of hospitalizations for heart failure exacerbations continues to increase and most patients will ultimately die of complications related to heart failure. Implantable left ventricular assist devices (LVAD) are currently in use throughout the world with increasing frequency. This paper is a comprehensive review about mechanical support, focusing on a general description of the differents LVAD, complications and mortality.

[Validation of the otoacoustic emissions in presbyacusis]. / Valoración de las otoemisiones acústicas en la presbiacusia.

INTRODUCTION: With the development of medical technology, human life expectancy has increased. This has increased the incidence of senile pathologies and the associated problems for this people. In the field of otolaryngology, one of these pathologies is presbyacusis. This study attempts to find relationships between presbyacusis and different parameters related to it. MATERIAL AND METHODS: A cross sectional study was carried out with 59 volunteers aged between 50-89 from different homes for the elderly in the city of Reus. The subjects presented with or without symptoms of deafness. An AOE test was then performed to determine the different parameters. Significant response criteria were: otoemissions with a signal-noise ratio of 3 dB or greater or 65% reproducibility in < 2 bands. The results obtained were analyzed through a computer statistics program (SPSS) and Microsoft Excel for the graphics. RESULTS: The results of the characteristics of the test are within the acceptable limits of quality. The prevalence of subjects with AOE was 22%, with an average age of the subjects of around 69 years. We did not find statistical differences in the presbyacusis group with respect to the parameters of intensity and reproductability, but there was a correlation in the duration of the test. In the analysis of frequencies in the reproductibility parameters we observed a fall in the 5 KHz. The ratio signal-noise showed a similar tendency. It is necessary to emphasize the worst results in the different parameters from the right ear the left one. CONCLUSIONS: The AOE offers information in frequencies of 1 and 2 KHz, where we can see a reduction in the reproducibility in the presbyacusis group. We see a longer test time, in the presbyacusis group and this may be used to control the development of the disease.

The InterCon network: a program for education partnerships at the University of Texas-Houston Health Science Center.

The University of Texas-Houston Health Science Center (UT-Houston) has created programs and activities to address the state's pressing needs in minority education. Through InterCon, a network of universities and K-12 schools, UT-Houston works with its partners to identify competitive candidates in the current pool of minority graduates with bachelor's degrees and to help them--along with their non-minority counterparts--progress in their education. Another objective is to expand the pool of minorities underrepresented in medicine who complete high school and go to college. In 1994 UT-Houston and Prairie View A&M University created a collaborative venture to provide new educational opportunities at UT-Houston for Prairie View's predominantly African American students. A three-track summer internship program--a result of that collaboration--has since been expanded to partnerships with other minority and majority universities throughout Texas. In 1998, for example, 108 undergraduate students from these universities (and 40 other universities nationwide) participated in research, professional, and administrative summer internships at UT-Houston. The InterCon network also has partnerships with K-12 schools. UT-Houston works with inner-city, suburban, and rural school districts to develop education models that can be transferred throughout the state. The partnerships deal with helping to teach basic academic skills and computer literacy, improve science-related instruction, meet demands for health promotion materials and information for school-initiated health and wellness programs, and develop distance-learning paradigms. UT-Houston views InterCon as a program helping Texas institutions to engage and adapt to the socioeconomic factors, demographic changes, and technology explosion that currently challenge public education.

[Factors affecting smoking of elementary and high school children from Chile]. / Factores que inciden en el hábito de fumar de escolares de educación básica y media del Chile.

INTRODUCTION: Despite the harmful effects of tobacco millions of people continue to smoke. Many of these smokers, including most news smokers, are adolescents-both in Chile and in other countries. This study sought to determine the prevalence of smoking among Chilean elementary and high school children and to quantify the relative impact of socioeconomic, socio-cultural, familial, mass media exposure, demographic, educational and psychosocial factors on smoking. MATERIAL AND METHOD: A representative sample of 2,967 elementary and high school children from Chile's Metropolitan Region were chosen at random, by grade (IV, VI, and VIII elementary school grades and I and IV high school grades), sex, type of school and geographical area. Prevalence of smoking was determined through an anonymous self-administered questionnaire. Socioeconomic status (SES) was measured by means of Graffar's modified method and family conditions, mass media exposure and psychosocial factors were registered. Scholastic achievement was measured by a language and mathematics test and other educational variables were considered. Statistical procedures included analysis of variance. Student's test and Scheffe's test for comparison of means, correlation, stepwise multiple regression, chisquared and PAHO/WHO risk approach methodology. RESULTS: Prevalence of smoking (10.6%) increased significantly with age, from 1.3% in school children aged < 13 years to 15.4% and 36.9%, in adolescent students aged 13-15 years and > or = 16 years, respectively (p < 0.001) and was higher in females than in males. Pleasure level (r = 0.499 p < 0.001), level of rebelliousness (r = 0.124 p < 0.0001), family recreation level (r = -0.131 p < 0.0001) and the percentage of school attendance (r = -0.118 p < 0.0001) were the independent variables with the greatest explanatory power in smoking variance (r2 = 0.2860), but pleasure level was the variable with the greatest explanatory power in the explained variance (89.2%) and with the greatest RR (34.3). The relative impact of the independent variables on smoking varied according to age, sex and SES. CONCLUSIONS: The result demonstrate that pleasure level, level of rebelliousness, family recreation level and the percentage of school attendance were the independent variables with the greatest explanatory power in smoking. These findings may be useful in the implementation of education and health policies with a view to the reduction of this serious public health risk factor.

Factores que inciden en el habito de fumar de escolares de educación basica y media del Chile / Factors affecting Chilean elementary and high school children's smoking

Considerando a indiscutível evidência dos efeitos adversos do fumo para a saúde, milhöes de pessoas continuam fumando. A situaçäo é de maior gravidade, já que muitos dos fumantes e a maioria dos novos fumantes, tanto no Chile, como em outros países, säo adolescentes. Decidiu-se realizar estudo com o objetivo de determinar a prevalência do tabagismo em escolares chilenos e quantificar o impacto de fatores socioeconômicos, socioculturais, familiares, de exposiçäo aos meios de comunicaçäo de massa, demográficos, educacionais e psicossociais. Foi selecionada uma amostra aleatória representativa e proporcional de 2.967 escolares de educaçäo básica e média, na Regiäo Metropolitana do Chile, de acordo com o grau do curso (IV, VI e VIII básico de I e IV médio), sexo, tipo de escola e área geográfica. A prevalência de tabagismo foi determinada por meio de questionário auto administrativo. O nível socioeconômico (NSE) foi avaliado pelo métdo Graffar modificado determinando-se além das condiçöes familiares, a exposiçäo aos meios de comunicaçäo de massa e aos fatores psicossociais. O rendimento escolar foi determinado por um teste de idiomas e de matemáticas, além de outras variáveis educacionais. A análise estatística inclui análise de variância, teste "t" de Student e teste de Scheffe para comparar as médias, correlaçäo, regressäo múltipla, teste do qui-quadrado e o método de OPS/OMS para o cálculo de risco relativo (RR). A prevalência de tabagismo (10,6 por cento) aumentou significativamente com a idade de 1,3 por cento nos escolares menores de 13 anos, a 15,4 a 36,9 por cento nos adolescentes entre 13-15 anos e > ou = 16 anos, respectivamente (p<0,001), e foi maior nos escolares do sexo feminino. Os níveis de prazer(r=0,499 p<0,001), rebeldía (r=0,124 p<0,001), foram as variáveis independentes com o maior poder de explicaçäo na variância de tabagismo (r2=0,2860). Porém o grau de prazer foi a variável com o maior poder de explicaçäo na variância (89,2 por cento) e com maior RR (34,3). O impacto relativo às variáveis independentes sobre o tabagismo foi diferente de acordo com a idade, sexo e nível socioeconômico. Os resultados podem ser úteis para a implementaçäo das políticas de educaçäo e saúde e para a prevençäo deste fator de risco para a saúde da populaçäo escolar.

Circunferencia craneana de escolares chilenos de 5 a 18 años y nivel socioeconómico / Head circumference of chilean school children ages 5 to 18 years old and socioeconomic status

The objective of this study were to determine the head circumference (HC) values of a representatiive sample of 4.346 school children ages 5 to 18 years from Chile's Metropolitan Region, to carry out a comparative study with international referencew data of Tanner, Nellhaus and Roche et al, and to compare the HC values by socioeconomic status (SES). The sample included school children of both sex, from public, private subsidized and private non-subsidized schools and from urban and rural areas. HC was measured according to Jellife norms and SES through Graffar's Modified Method. Results showed a high correlation between HC values of school-age children fron Chile's Metropolitan Region and Tanner, Nellhaus and Roche et al Tables, with similar growth curves; from this manner, HC values of school-age children from Chile's Metropolitan Region not differ significantly from international reference data. HC values were, in general, significantly higher in males than females in all age groups, in students fron high SES to compare with other socioeconomic strata and in older school children. This fact was tested too in 1992, in a representative sample of 605 poor school children beneficiaries from the School Feeding Program in Peñalolén and Pirque Counties from Chile's Metropolitan Region with similar results. It can be concluded that HC values of school-age children from Chile's Metropolitan Region were higher in males than females, in high SES compared with medium and low SES and in older students and does not differ significantly from international reference data

Estado nutricional de escolares en condiciones de pobreza urbana y rural: región metropolitana, Chile, 1986-1987 / Nutritional status in school children of urban and rural poor conditions at metropolitan region, Chile, 1986-1987

The aim of this study was to compare the nutritional status of poor children from urban and rural areas and to quantify the impact of socioeconomic, sociocultural and family variables on nutritional status. Weight/age, height/age, weight/height and head circumference percentages were measured in a representative sample of 4509 school children, 39 percent belonging to a low socioeconomic status and living in the metropolitan region, chosen according to grade, type of school, sex and geographic area. Children coming from rural areas had significantly higher percentages of undernutrition than children from urban areas according to weight/age, (47 vs 34 percent) and weight/height (7,7 vs 4.6 percent); likewise they had a higher proportion of height/age ratios below 90 percent (10,3 vs 5.2 percent). Head circumference was below 100 percent in 77 and 65 percent of rural and urban children. Brachial anthropometric variables were also lower in rural children. The number of siblings and family size were the independent variables with the greatest explanatory power for weight/age and height/age variations. Mother's instruction in urban areas and crowding, family alcoholism and mother's instruction in rural areas, were the independent variables with the greatest explanatory power for head circumference variation. It is concluded that the significant relationship found between socioeconomic, sociocultural and family variables and nutritional status is relevant, considering that the sample was homogenous in each geographic area

Non-genotoxic carcinogens. Approaches to their risk assessment.

Epidemiological studies support the idea that most human cancers are related to chemicals present in the human environment. In turn, chemicals are believed to cause cancer via either genotoxic or non-genotoxic mechanisms. There were described in literature several simple, rapid and inexpensive short term tests to reasonably predict the genotoxic nature of chemicals but in contrast, there is no reliable test or battery of tests available to predict the carcinogenicity of non-genotoxic compounds and this poses a major problem to their risk assessment. In addition, there are conflictive opinions about risk assessment needs for both classes of carcinogens. Some workers believe that for non-genotoxic carcinogens, thresholds for exposure can be drawn while others do not. In this review, the reasons behind both of these opinions and the present hypotheses about the mechanism of action of non-genotoxic carcinogens are described and analyzed in relation to future needs.

[Economy of coupons: its application to a program of weight reduction in adolescents]. / La economía de fichas: su aplicación a un programa de reducción de peso en adolescents

The results obtained in a group of 12 obese adolescents are reported. They were managed following a motivational system called economy of coupons with the purpose of obtaining a drop in the overweight they showed. The study was divided into three stages: A, B and C. Only stage B included the experimental variable (economy of coupons). The patients kept a notebook with daily records of weight, diet and physical exercise to be evaluated by the research workers. If they reached the goals set for them, they were given strengthening stimuli to support such activity. From the analysis of the group for the body weight and its statistic comparison, it was found that in the A - B interaction, the "p" level was significant in the weight loss. In the B - C interaction, the value for "p" was less than 0.05 in relation to the ponderal increment and in A - C interaction, there was no significance. From this study, the evidence showed that results of A - C interaction were poor and therefore, rehabilitation was not obtained. From the above results, the inclusion of a fourth stage is suggested for further studies where the application of economy of coupons would gradually disappear until a desired behavior is maintained.