Minimization of lead and copper interferences on spectrophotometric determination of cadmium using electrolytic deposition and ion-exchange in multi-commutation flow system

A new strategy for minimization of Cu2+ and Pb2+ interferences on the spectrophotometric determination of Cd2+ by the Malachite green (MG)-iodide reaction using electrolytic deposition of interfering species and solid phase extraction of Cd2+ in flow system is proposed. The electrolytic cell comprises two coiled Pt electrodes concentrically assembled. When the sample solution is electrolyzed in a mixed solution containing 5% (v/v) HNO3, 0.1% (v/v) H2SO4 and 0.5 M NaCl, Cu2+ is deposited as Cu on the cathode, Pb2+ is deposited as PbO2 on the anode while Cd2+ is kept in solution. After electrolysis, the remaining solution passes through an AG1-X8 resin (chloride form) packed minicolumn in which Cd2+ is extracted as CdCl4/2-. Electrolyte compositions, flow rates, timing, applied current, and electrolysis time was investigated. With 60 s electrolysis time, 0.25 A applied current, Pb2+ and Cu2+ levels up to 50 and 250 mg 1-1, respectively, can be tolerated without interference. For 90 s resin loading time, a linear relationship between absorbance and analyte concentration in the 5.00-50.0 μg Cd 1-1 range (r2 = 0.9996) is obtained. A throughput of 20 samples per h is achieved, corresponding to about 0.7 mg MG and 500 mg KI and 5 ml sample consumed per determination. The detection limit is 0.23 μg Cd 1-1. The accuracy was checked for cadmium determination in standard reference materials, vegetables and tap water. Results were in agreement with certified values of standard reference materials and with those obtained by graphite furnace atomic absorption spectrometry at 95% confidence level. The R.S.D. for plant digests and water containing 13.0 μg Cd 1-1 was 3.85% (n = 12). The recoveries of analyte spikes added to the water and vegetable samples ranged from 94 to 104%. (C) 2000 Elsevier Science B.V.

Simultaneous determination of As, Cu, Mn, Sb, and Se in drinking water by GFAAS with transversely heated graphite atomizer and longitudinal zeeman-effect background correction

A method has been developed for the direct and simultaneous determination of As, Cu, Mn, Sb, and Se in drinking water by electrothermal atomic absorption spectrometry (ETAAS) using a transversely heated graphite tube atomizer (THGA) with longitudinal Zeeman-effect background correction. The thermal behavior of analytes during the pyrolysis and atomization stages was investigated in 0.028 mol L-1 HNO3, 0.14 mol L-1 HNO3 and 1 + 1 (v/v) diluted water using mixtures of Pd(NO3)2 + Mg(NO3)2 as the chemical modifier. With 5 μg Pd + 3 μg Mg as the modifier, the pyrolysis and atomization temperatures of the heating program of the atomizer were fixed at 1400°C and 2100°C, respectively, and 20 μL of the water sample (sample + 0.28 mol L-1 HNO3, 1 + 1, v/v), dispensed into the graphite tube, analytical curves were established ranging from 5.00 -50.0 μg L-1 for As, Sb, Se; 10.0 - 100 μg L-1 for Cu; and 20.0 - 200 μg L-1 for Mn. The characteristic masses were around 39 pg As, 17 pg Cu, 60 pg Mn, 43 pg Sb, and 45 pg Se, and the lifetime of the tube was around 500 firings. The limits of detection (LOD) based on integrated absorbance (0.7 μg L-1 As, 0.2 μg L-1 Cu, 0.6 μg L-1 Mn, 0.3 μg L-1 Sb, 0.9 μg L-1 Se) exceeded the requirements of the Brazilian Food Regulations (decree # 310-ANVS from the Health Department), which established the maximum permissible level for As, Cu, Mn, Sb, and Se at 50 μg L-1, 1000 μg L-1, 2000 μg L-1, 5 μg L-1, and 50 μg L-1, respectively. The relative standard deviations (n = 12) were typically < 5.3% for As, < 0.5% for Cu, < 2.1% for Mn, < 11.7% for Sb, and < 9.2% for Se. The recoveries of As, Cu, Mn, Sb, and Se added to the mineral water samples varied from 102-111%, 91-107%, 92-109%, 89-97%, and 101-109%, respectively. Accuracy for the determination of As, Cu, Mn, Sb, and Se was checked using standard reference materials NIST SRM 1640 - Trace Elements in Natural Water, NIST SRM 1643d - Trace Elements in Water, and 10 mineral water samples. A paired t-test showed that the results were in agreement with the certified values of the standard reference materials at the 95% confidence level.

Electromyographic validation of basic exercises for physical conditioning programmes IV. Analysis of the deltoid muscle (anterior portion) and pectoralis major muscle (clavicular portion) in frontal-lateral cross, dumbbells exercises

The electromyographic activity of the shoulder muscles deltoid - anterior portion (DA) and pectoralis major - clavicular portion (PMC) was tested on 24 male volunteers using a 2 channel TEC A TE4 electromyograph and Hewlett Packard surface electrodes during the execution of four different modalities of frontal-lateral cross, dumbbells exercises. The results showed that all of the tested exercises developed high levels of action potential for both muscles. So, we jusfity the indication of all of them for physical fitness programmes for DA and PMC. Some suggestions to the use of the tested exercises are presented.

Electromyographic validation of basic exercises for physical conditioning programmes V. The comparison of the response in the deltoid muscle (anterior portion) and the pectoralis major muscle (clavicular portion) determined by the frontal-lateral cross, dumbbells and the rowing exercises

The action potential level for shoulder muscles deltoid-anterior portion (DA) and pectoralis major-clavicular portion (PMC) determined by four different modalities of execution of rowing exercises, each one with two different grips, was recorded. These were compared with the action potential level determined for the same muscles by four different modalities of execution of the frontal-lateral cross, dumbbells exercises. Twenty-four male volunteers were examined using a 2 channel TECA TE4 electromyograph and Hewlett Packard surface electrodes. The statistic analysis showed significant (p<0,05) superiority for all the frontal-lateral cross, dumbbells exercises in comparison to all rowing exercises for the PMC, for the DA this generalized supremacy was not observed.

Laryngeal electromyography in normal Brazilian population

Quantitative analysis of normal values of motor unit action potentials duration and amplitude of muscles tireoaritenoideus (TA), cricotireoideus (CT), cricoaritenoideus lateralis (CAL), and cricoaritenoideus posterioris (CAP) was performed in 14 adult normal Brazilian volunteers. The recordings were obtained by percutaneously inserted concentric needle electrode. Different motor unit action potentials were manually selected in each muscle for quantitative computerized analysis of duration and amplitude. The mean values for duration and amplitude were respectively 3.8 ms and 413 μV for TA, 4.9 ms and 585 μV for CT, 4.1 ms and 388 μV for CAL and 4.5 ms and 475 μV in CAP. There were no similar reports of normal values of motor unit action potentials in Brazilian subjects.

Série plaquetaŕria: Valores de referência e correlações observadas entre os parâmetros plaquetários em uma população aparentemente saudável

Mean platelet volume (MPV), platelet distribution width (PDW) and plateletcrit (PCT) platelet parameters can be important to improve the initial identification of platelet disorders. The purpose of this study is to establish reference values for the platelet count (PLT), MPV, PDW and PCT in a population of 1346 apparently healthy adults, from both sexes, as well as to evaluate the correlations among these platelet parameters and to build the necessary nomograms for the clinical interpretations of the platelet indices. The platelet parameters were analyzed in blood samples collected into dipotassium ethylenediaminetetra-acetic acid (K 2 EDTA) by an electrical aperture-impedance method. There were non-linear and an inverse correlations between MPV and PLT, and between PDW and PLT, throughout the reference range of platelet count: the change in MPV and PDW was most accentuated at the lower platelet counts. Because of this non-linear inverse correlation, MPV versus PLT and PDW versus PLT nomograms were built. These correlations among the platelet parameters on a normal population provide a better understanding of these indices and may contribute to establish the real clinical significance of these platelet parameters in many diseases.

Nasal width as a guide for the selection of maxillary complete denture anterior teeth in four racial groups

Purpose: Selecting artificial teeth for edentulous patients is difficult when pre-extraction records are not available. Various guidelines have been suggested for determining the width of the maxillary anterior denture teeth. This study was undertaken to evaluate the use of the nasal width as a guide for the selection of proper width maxillary anterior denture teeth in four racial groups of the Brazilian population. Materials and Methods: One hundred and sixty subjects (40 Whites, 40 Mulattos, 40 Blacks, and 40 Asians) were selected. Using a sliding caliper, the nasal width and the intercanine distance were measured. The Pearson product-moment correlation coefficient was used to determine the relationship between the above measurements. A prediction was made of the percentage of subjects of the White, Mulatto, Black, and Asian populations in which the selection error due to the clinical application of the method of the nasal width would be within 0 to 2 mm, within 2 to 4 mm, and greater than 4 mm. Results: The four racial groups showed a weak correlation between the intercanine distance and the nasal width. In 39.7% of the White, 55.7% of the Mulatto, 81.9% of the Black, and 48.2% of the Asian populations, errors greater than 4 mm would be present with the use of the nasal width. Conclusions: The correlation found between the intercanine distance and the nasal width was not high enough to be used as a predictive factor. The relationship between natural tooth width and artificial tooth width as predicted by the nasal width showed that the nasal width method is not accurate for all the studied groups. Copyright © 2006 by The American College of Prosthodontists.

Bone mineralization in Brazilian adolescents: The years of maximum bone mass incorporation

Puberty is the fundamental period for bone mass (BM) acquisition. In this period mineralization is found to increase with levels of high bone formation. The critical years of intense bone anabolism deserve special attention, as adequate gain could minimize fracture risk in later years. The objective of this work was to study bone mineral content (BMC) and bone mineral density (BMD) in male adolescents with age bracket and maturation level. Sixty-one healthy male 10 to 19 year-olds were evaluated for calcium intake, weight, stature, BMI, puberty stage and BMC and BMD in the lumbar spine and femur. BM was measured by bone densitometry (DXA). Calcium intake was calculated by recording 3 days diet. Puberty stage was defined as per Tanner. Descriptive statistics was used with means and standard deviations, linear correlation, and analysis of variance for comparison between age groups, and the Tukey test (p<0.05). Linear correlation was positive and indicated body weight as the main correlation variable with BMD in both studied locations (p<0.01). BMC and BMD increased with age, differences were significant from 14 to 15 years, and when adolescents reached Tanner stage G4. These results showed a pronounced increase in bone mineralization, with the years after 14 to 15 being critical for BM acquisition in Brazilian adolescents.

Ophthalmic patterns of captive brown brocket deer (Mazama gouazoubira)

Captive brown brocket deer (Mazama gouazoubira) were manually restrained to assess tear production by the Schirmer tear test I to measure intraocular pressure by applanation tonometry, to examine ocular conjunctival epithelial cells via cytologic and histologic samples, and to survey ocular conjunctival microflora by microbiologic culture. The mean value for the Schirmer tear test I was 8.9 ± 1.8 mm/min, and the mean intraocular pressure was 15.3 ± 3.1 mm Hg. Conjunctival epithelium contained stratified pavimentous layers of cells, and the microflora consisted of predominantly gram-positive bacteria. Copyright 2007 by American Association of Zoo Veterinarians.

Fatores de risco para doenças cardiovasculares em idosos com diabetes mellitus tipo 2

The aim of this study was to analyze the risk factors related to the cardiovascular diseases (CVRF) in elderly type 2 diabetics. A cross-sectional observational study was carried out on 100 elderly patients attending the Rehabilitation Center of Araraquara (CRRA), São Paulo State, Brazil, from March to December, 2004. The majority were married, female, white, with a low income and low educational level. Regarding habits and style of life, the subjects had an adequate diet, were sedentary, non-smoking and non-drinking. In the population of 100, 42% were overweight, 42% obese, 71% had above-normal waist measurements and 84% high waist-to-hip ratios. Concerning the CVRF, it was observed that more than half had hypertension, hypercholesterolaemia and hypertriglyceridaemia. 84% had high values of LDL-cholesterol and 59% HDL-cholesterol levels below the reference values, 78% high levels of fasting glycemia, 76% glycohemoglobin and 57% fibrinogen and thus subject to cardiovascular risk. The results showed a high frequency of cardiovascular risk factors, differing according to sex and the age.

Results of the GEP-ISFG collaborative study on an X-STR Decaplex

A collaborative work was carried out by the Spanish and Portuguese ISFG Working Group with a PCR multiplex for X chromosome STRs. Markers were selected among those described as polymorphic in humans and that have been used by some laboratories in forensics. Primers and various technical methods were investigated with the aim of optimizing a multiplex for the 10 selected X-STRs. Primer mix stock solutions were sent to the laboratories that were asked to analyse two female bloodstains, taking as reference the genetic profiles from 9947A, 9948 and NA3657 samples. In this work, we report the results obtained by 30 GEP-ISFG laboratories, using this Decaplex, as well as alternative technical conditions that also produced good results. © 2008 Elsevier B.V. All rights reserved.

Neuromuscular recovery of the biceps brachii muscle after resistance exercise

The aim of this study was to determine the time to restore the biceps brachii (BB) electromyographic (EMG) activity after the biceps curl (BC) exercise, at different intensities. Ten males performed initially maximal voluntary isometric contractions (MVC) of the elbow flexors, followed by one isometric submaximal contraction at 50% MVC (reference contraction). After this, four bouts of the BC at 25%, 30%, 35%, and 40% 1 RM during 1 minute (randomly assigned, with 10 minutes rest between them) were performed. During the rest intervals at preestablished moments (15 seconds, 1, 3, 5, and 10 min), isometric 50% MVC were performed. The EMG variables (root mean square [RMS], zero crossings [ZC], median frequency, [MF] and peak power [PP]) at rest were compared with reference values. Immediately after the exercise, RMS and PP increased, while ZC and MF decreased, indicating fatigue. After 1 minute most of the variables were similar to the reference. Different load levels did not affect the EMG recovery. In conclusion, the EMG variables recovered after 1 minute rest, indicating the optimal muscular condition for subsequent bouts. Copyright © Taylor & Francis Group, LLC.

Fatores preditivos do sucesso da inseminação intrauterina: A morfologia espermática de acordo com o novo manual de laboratório da Organização Mundial de Saúde

Objective: The aim of our study was to assess the likelihood of IUI success as a function of the previously described predictive factors, including sperm morphology according to the new reference values defined by WHO. Material and Methods: This retrospective study enrolled 300 couples which underwent IUI. Regression analyses were used to correlate maternal age, number of preovulatory follicles on the day of hCG administration, number of inseminated motile sperm, and normal sperm morphology with clinical pregnancy. Results are expressed as odds ratio (OR) with 95% of confidence intervals (CI). Results: Women older than 35 years showed a lower pregnancy rate (6.5% vs 18.2%, p=0.017). Logistic regression models confirmed the lower chance of pregnancy occurrence for older women (OR: 0.39; CI: 0.16-0.96; p=0.040). The presence of two or more preovulatory follicles on the day of hCG administration resulted in higher pregnancy rate when compared to cases in which only one preovulatory follicle was present (18.6% vs 8.2%, p=0.011). The regression model showed a more than two fold increase on probability of pregnancy when two or more preovulatory follicles were detected (OR: 2.58; CI: 1.22-5.46, p=0.013). The number of inseminated motile sperm positively influenced pregnancy occurrence (OR: 1.47; CI: 0.88-3.14, p=0.027). Similar pregnancy rates were observed when semen samples were classified as having normal or abnormal morphology (10.6% vs 10.2%, p=0.936). Conclusion: Our results demonstrate that sperm morphological normalcy, according to the new reference value, has no predictive value on IUI outcomes. © Todos os direitos reservados a SBRA - Sociedade Brasileira de Reprodução Assistida.

Developing a system for down-hole seismic testing together with the CPTU

This paper presents a system for performing down-hole seismic test together with the piezocone test in order to determine the shear wave velocity (Vs) and for calculating the maximum shear modulus (Go); a basic parameter for analyzing the dynamic soil behavior and a reference value of the soil stiffness. The system components are described and tests results for checking the geophone response are also presented, both before and after installation into the probe. The system was used in down-hole tests carried out at three experimental research sites located in the interior of Sao Paulo State, Brazil, where in situ seismic test results are available. The Vs values measured in down-hole tests carried out with this system were consistent with those determined in cross-hole tests and with a commercial seismic piezocone, which enabled to validate the developed system.

Aerobic fitness evaluation during walking tests identifies the maximal lactate steady state

Objective. The aim of this study was to verify the possibility of lactate minimum (LM) determination during a walking test and the validity of such LM protocol on predicting the maximal lactate steady-state (MLSS) intensity. Design. Eleven healthy subjects (24.2 ± 4.5 yr; 74.3 ± 7.7 kg; 176.9 ± 4.1 cm) performed LM tests on a treadmill, consisting of walking at 5.5 km h -1 and with 20-22% of inclination until voluntary exhaustion to induce metabolic acidosis. After 7 minutes of recovery the participants performed an incremental test starting at 7% incline with increments of 2% at each 3 minutes until exhaustion. A polynomial modeling approach (LMp) and a visual inspection (LMv) were used to identify the LM as the exercise intensity associated to the lowest [bLac] during the test. Participants also underwent to 24 constant intensity tests of 30 minutes to determine the MLSS intensity. Results. There were no differences among LMv (12.6 ± 1.7 %), LMp (13.1 ± 1.5 %), and MLSS (13.6 ± 2.1 %) and the Bland and Altman plots evidenced acceptable agreement between them. Conclusion. It was possible to identify the LM during walking tests with intensity imposed by treadmill inclination, and it seemed to be valid on identifying the exercise intensity associated to the MLSS. Copyright © 2012 Guilherme Morais Puga et al.