Resumo em português Objetivo: verificar o estado nutricional relativo ao ferro, cobre e zinco e a correlação entre índice de massa corporal, níveis séricos e dietéticos desses elementos, em adolescentes durante o estirão pubertário. Métodos: estudo descritivo, do tipo corte transversal, envolvendo uma amostra de 47 adolescentes atendidos em ambulatório de adolescência clínica, durante o período de março a dezembro de 1999, que se apresentavam no estirão pubertário, do total d (mais) e 360 que freqüentaram o ambulatório no período, sendo 19 rapazes na faixa etária de 12,3 a 16 anos, e 28 moças na faixa etária de 11,1 a 13,6 anos. Variáveis analisadas: dietética (recordatório de 24 horas, freqüência e registro alimentar) para determinar a ingestão de ferro, cobre e zinco; antropométrica (peso e altura) para aferição do índice de massa corporal; bioquímica (dosagem sérica de ferro pelo kit in vitro Diagnóstica, ferritina pelo kit Immulite, cobre e zinco por espectrofotometria de absorção atômica). Utilizou-se o coeficiente de Spearman para análise estatistíca. Resultados: dos 47 adolescentes em estirão pubertário, apresentaram ingestão adequada de: ferro (95% e 36%), cobre (53% e 57%) e zinco (21% e 21%) nos sexos masculino e feminino, respectivamente. A maioria dos adolescentes era eutrófica segundo os percentis do IMC. Bioquimicamente, os rapazes apresentaram valores normais para ferro e zinco em toda a amostra; para cobre em 95% e para ferritina em 84%. As moças também apresentaram valores normais de ferro e zinco; para cobre em 96,4% e para ferritina em 96%. Não houve correlação estatisticamente significante entre IMC e concentração sérica de ferro, ferritina, cobre e zinco, e entre concentração sérica e ingestão dietética dos minerais estudados, nem tampouco para a relação ferro sérico e ferritina. Conclusões: não se sabe, até o momento, se os níveis séricos de zinco e cobre flutuam durante o crescimento, ou se cada indivíduo tem um nível estável destes minerais durante o estirão. Os níveis séricos normais de ferro, cobre e zinco na maioria dos adolescentes avaliados podem estar refletindo a habilidade do organismo em fazer ajustes homeostáticos. Resumo em inglês Objective: to examine iron, copper and zinc nutritional status and their correlation with Body Mass Index (BMI), serum and dietetic levels in adolescents during the pubertal growth spurt. Methods: a descriptive cross-sectional study involving a sample of 47 adolescents out of 360 patients (19 boys, whose ages ranged from 12.3 to 16 years and 28 girls, whose ages ranged from 11.1 to 13.6 years), who were seen at a clinic for adolescents from March to December 1999. The var (mais) iables analyzed were: Diet (24 hours Dietary Recall, Food Frequency Intake Questionnaire and Food Register Methods) to determine iron, copper and zinc intake; anthropometry (weight and height) to check BMI; biochemistry (measure of serum iron level through a Diagnóstica kit in vitro; ferritin through Immulite kit, and atomic absorption spectrophotometry for biochemical evaluation of serum iron, ferritin, copper and zinc. Spearman coefficient correlation was used for statistical analysis. Results: forty seven adolescents during pubertal growth spurt showed adequate ingestion: iron (95% and 36%), copper (53% and 57%) and zinc (21% and 21%) in males and females, respectively. Most of them were eutrophic according to the BMI percentiles. Biochemically, boys presented normal values for serum iron and zinc in the whole sample, 95% for copper and 84% for ferritin. Girls also presented normal values for iron and zinc values in the whole sample, 96.4% for copper and 96% for ferritin. There were no statistically significant correlation between BMI and serum Fe, ferritin, Cu and Zn concentrations and between serum concentration and dietetic ingestion of the studied minerals, neither between serum iron and ferritin. Conclusions: it is not clear if serum levels of Zn and Cu are floating during the growth process or if each adolescent has a stable level of these minerals during the pubertal growth spurt. Normal Fe, Cu and Zn serum levels in most adolescents evaluated may reflect the organism ability to accomplish homeostatic adjustments.
Resumo em português Foram conduzidos três ensaios distintos no período de dezembro de 2002 a fevereiro de 2003, no município de Três Pontas - MG, com o objetivo de avaliar a influência de doses de cobre sobre a produção de alface americana (Lactuca sativa L.). Utilizou-se o delineamento de blocos ao acaso com cinco tratamentos, sendo uma testemunha e quatro doses de cobre (0,15, 0,30, 0,45 e 0,60 l/ha); e 4 repetições, aplicadas em três diferentes épocas via foliar (14, 21 e 28 di (mais) as após o transplantio). A maior massa fresca comercial por planta foi constatada na dose de 0,35 l/ha de cobre, com um incremento de 20,5% no rendimento, comparativamente a testemunha. A aplicação aos 21 e 28 dias após o transplante promoveu os maiores comprimentos de caule com 5,7 e 6,1 cm, respectivamente. A dose de 0,45 l/ha de cobre elevou a circunferência da cabeça comercial. Para sanidade das folhas constatou-se efeito quadrático, no qual a dose de 0,41 l/ha de cobre proporcionou a melhor sanidade das folhas externas, quando aplicada aos 21 e 28 dias. Não se observou efeito significativo dos tratamentos para massa fresca total. Resumo em inglês Three distinct trials were carried out at Três Pontas city in Minas Gerais Satate, Brazil, from December 2002 to February 2003 with the objective of evaluating the influence of doses of copper on the yield of crisphead lettuce (Lactuca sativa L.). The experimental design was in randomized complete blocks with five treatments, being one control and four doses of copper ( 0.15; 0.30; 0.45 and 0.60 l/ha) and three application times applied via foliar (14, 21 and 28 days aft (mais) er transplanting). Each application time was considered one trial. The highest plant commercial fresh mass was obtained at the doses of 0.35 l/ha of cooper, with an increment of 20.5% of increase in yield, comparatively to the control. The application at 21 and 28 days after transplanting showed the higlest stem length with 5.7 and 6.1 cm in length, respectively. The dose of copper (0.45 l/ha) promoted the highest circumference of the commercial head. Regarding the sanity of the leaves a quadratic effect was verified, in which, the dose of copper (0.41 l/ha) showed the best sanity of the external leaves, when applied to the 21 and 28 days. No significant effect among the treatments for total fresh matter was observed.
Resumo em inglês A critical study of three methods for the determination of lactic acid (EDWARDS, MENDEL & GOLDSCHEIDER, MILLER & MUNTZ) is presented and some modifications are proposed. It was shown t hat more accurate results could be obtained with Edward's technic when an Iena glass filter is connected with the absorption tube. Before the dropping of the permanganate solution it is necessary to pass a current of air through the reaction flask to avoid the oxidation of the non-lactic ac (mais) id substances which interfere with the reaction. The absorption tube must be maintained at 18°C during the destillation and the titration of the bisulphite binding aldehyde at 4°C. When the sample contains more than 5 mg it is useful to work with greater quantities of the bisulphite. More permanganate is consumed when the lactic acid concentration is higher. The sensivity of the method permits the titration of 0.04 mg to 5 mg of lactic acid in the sample. The calculated error of the method gave 0.018 % and the normal values for blood determined in 20 human cases averaged 10.30 mg per 100 ml (Table VI). MENDEL and GOLDSCHEIDER'S method was modified in the following details: Somogyis deproteinization was performed instead metaphosphoric acid as in the original method; to avoid the evaporation of the acetic aldehyde during the heating time with sulfuric acid a special glass stopped tube is proposed (Fig. 2). The reaction with sulfuric acid and veratrol is performed in an ice bath. Blood proteins precipitants were tried and Somogyi's lattest tecnic showed better results (Table V). Colorimetric readings were done in the PULFRICH photometer using filter S 53 and a 10 mm cup. The method is accurate within an error of 0.23 % and samples of 5 to 70 microg. could be easily determined. Normal values for human blood averaged 10.78 mg per 100 ml. More accurate results were obtained with the technic of MILLER & MUNTZ. Slight modifications were introduced: deproteinization with copper sulfate and sodium tungstate; satured p-hydroxydiphenyl solution according to KOENEMANN which is stable for 5 months when stored in the ice-box. Using the PULFRICH step-photometer the error is 0.17% with samples varying from 0.1 to 10 microg. of lactic acid. The filter employed was S 57 with the 5 mm cup. The method was adapted to 0.1 ml of blood. Normal values for human blood gave an average of 10.58 mg per 100 ml.
Resumo em inglês In the beginning of this work a brief idea was given on what is understood as "clay", on the scientific methods applied to the study of the matter "clay" as well as on its conception with regard to the edaphic studies. A description is given of the methods of total and natural mechanical analyses which were employed in the agro-geological Department. The work is illustrated by a graphic showing the fractions of the mechanical analysis of the chief great soil types of the (mais) State of São Paulo. The fraction clay is then studied by chemical way in the following sequence : 1.° total chemical analysis, 2.° partial chemical analysis, 3.° chemical analysis of the Helmholz layer and 4.° study of the fixation of the ion Ca+ + in the already mentioned Helmholz layer. The first analysis separates and attacks the hydrated aluminium silicates, the hydrated oxyds of iron and aluminium, manganese, etc. In this analysis the relationship between silica and sesquioxyds was determined. The second type of attack or chemical analysis does not affect the hydrated silicates of aluminium, all others go in dissolution. In this analysis were determined chiefly the sesquioxyds in their free form in the clay complex. For the study of the Helmholz layer, i.e. the determination of changeable ions, solutes of NH4Cl N/l, HNO3 N/5, KCl N/l, etc. were used, percolation of these liquids being made through a layer of air dried soil. The relationship between soil and liquid was always 1:10. In this analysis, principally the cations K+, Ca++, Mg++, Al+ + +, H+ etc. were determined. With such determinations the calculations of the following values were obtained: S = sum of the changeable bases in ME; T = total value in ME of the sorptive power of the complex in each 100 g dried soil at 110° C. and V = percentage of saturation of the complexes with bases. Finally, the qualitative radiographic analysis of the fraction clay was carried out by means of the Debye-Scherrer-Hull method. For these studies the Siemens-Berlin apparatus was used, the transformer of which runs with all0-220 volts 60-cycle alternating current. The bulb has a copper anti-cathode and is fed by a current of 13 m.A. of intensity and the difference of potential is of 30,000, 35,000 and 47,000 volts. The flash of X-rays goes through the nickel filter in order to free it of the b irradiations which are deleterious. In this way, inciding vertically on the preparation, radiations CuK a with l = 1,539 A are obtained. The sensible film used was a Lawe-Film-Agfa, with an exposure going from 11/2 to 2 hours with 35,000 V. The chassis has a diameter of 57 mm. More than 500 radiographs of soil samples were taken, of those proceding from all districts of the State, 79 of which are presented in the present work. With this material the different constituents of the clay minerals contained in our soils were known. Thus, in the soils over the Archean geological formation, kaolinite is represented most frequently and abundantly ; the hydrargillite also appears commonly. The soils over the Glacial formation contain the same representatives and oscillations as those just mentioned. In the Corum-batai formation, quartz is the most important constituent. The Botucatu formation (lava) is that which gave origin to our legitimate red soils ; the mineralogical clay constituents of these soils are : 1.° large amount of hydrated oxyds of iron up to 35% of Fe2O3 for each 100 g of soil at 110° C. ; 2.° hydrargillite and 3.° kaolinite. The amount of the latter in the clay complex ranges between 9 and 25%. The sandy soils existing in the geological formations of lower and upper Baurú bear in their clays the following mineralogical constituents : 1.° kaolinite, 2.° montmorrillonitic type (on the upper Baurú only), 3.° hydrargillite (more common on the lower Baurú) and 4.° quartz, generally, in small percentages. These researches made it evident that the constituents of the clay fraction of our soils commonly have a small sorptive power related to the cations; it follows hence that they do not show a great power of retention of manure with the exception of the montmorrillonitic type.