Spectrophotometric kinetic determination of copper(II) trace amounts based on its catalytic effect on the reaction of the reduced 2,6-dichlorophenolindophenol and hydrogen peroxide.

A catalytic spectrophotometric method is presented for the determination of Cu(II), based on the oxidation of the leucocompound of the 2.6-dichlorophenolindophenol (DCPI)(r), in the presence of hydrogen peroxide and the catalytic effect of Cu(II) on this reaction in ammonia-ammonium chloride buffer solution of pH 10.5. The above reaction is followed spectrophotometrically at 562 nm. The study was carried out with a filter spectrophotometer equipped with a fiber optic and an immersed type optical cell of 1 cm. The optimum operating conditions regarding concentration of the reagents involved, pH and temperature were established. The interference effect of several metallic species was also investigated. It was found that the proposed method shows fairly good selectivity and sensitivity, simplicity and rapidity compared to other kinetic methods. The working curve of the recommended reaction-rate method is linear in the concentration range 5-300 ng/ml. The relative standard deviation for a standard solution of 30 ng/ml Cu(II) is better than 2.5%. The method was applied successfully on the determination of Cu(II) in a wide variety of real samples such as alloys, pharmaceuticals, foodstuffs and environmental samples. The results were compared to those received with official methods. Good agreement was attained.

Determination of glycerol in alcoholic beverages using packed bed reactors with immobilized glycerol dehydrogenase and an amperometric FIA system.

A flow injection analysis system incorporating amperometric detection and enzyme reactor for glycerol determination in alcoholic beverages is described. The reactor is based on the glycerol dehydrogenase system, and the enzyme was immobilized through chemical modification on several supporting materials such as aminopropyl and isothiocyanate controlled pore glass, aminopolystyrene resin and m-aminobenzyloxymethyl cellulose. NADH, the product of the enzymatic reaction, was monitored amperometrically with a three-electrode wall-jet type flow through cell, at + 0.5 V vs. Ag/AgCl. The method was evaluated in the presence or absence of potassium and the following linear dynamic ranges were found: 2 x 10(-5) -2 x 10(-4) mol l(-1) and 4 x 10(-5) -4 x 10(-4) mol l(-1), respectively. The interference effects of various compounds were also studied. The relative standard deviation was found to be better than 1.0% (n = 6). The reactors are stable for over a period of 3 months and after about 2500 injections. Under optimum working conditions the sampling frequency was 30 samples h(-1). The successive application of the method was confirmed by comparison with a reference method. The mean relative error is 2.2% and the recovery 95-102%.

Correlations between the BDI and CES-D in a sample of adolescent mothers.

Adolescent mothers were administered the Beck Depression Inventory (BDI), the Center for Epidemiologic Studies Depression Scale (CES-D), and the Diagnostic Interview Schedule for Children (DISC). They also were asked if they preferred the BDI or CES-D. The findings indicated that BDI and CES-D scores were significantly correlated, and that more adolescent mothers preferred the CES-D. Both the BDI and CES-D were correlated with the DISC; however, the BDI was more highly correlated with the Major Depression subscale, and the CES-D with the Dysthymia subscale.

PIP: This study investigates the correlation between the Beck Depression Inventory (BDI) and the Center for Epidemiologic Studies Depression Scale (CES-D) among adolescent mothers. It further analyzed how well the BDI and CES-D correlated with a clinical measure of depression, the Diagnostic Interview Schedule for Children (DISC). The BDI, CES-D and DISC were administered to African American and Hispanic adolescent mothers between the ages 13-21 years. They were also asked if they preferred the BDI or CES-D. The findings suggested that BDI and CES-D scores were significantly correlated. More adolescent mothers preferred the CES-D, stating that it was quick and simple while several commented that the BDI was depressing. Both the BID and CES-D were correlated with the DISC. However, the BDI was more highly correlated with the Major Depression subscale, and the CES-D with the Dysthymia subscale.

Psychosocial stressors among depressed adolescent mothers.

This study sought to determine whether depressed adolescent mothers experience more psychosocial stressors than do nondepressed mothers and which stressors best predict maternal depression. Subjects consisted of 154 adolescent mothers 14 to 21 years of age who were recruited 1 to 3 days postpartum. The Beck Depression Inventory was used to assess severity of depression, and the Problem Oriented Screening Instrument for Teenagers was administered to assess mothers' level of psychosocial functioning. Depressed mothers consistently reported more problems in most areas of psychosocial functioning. Additionally, the best predictors of maternal depression were mental health status, family relations, and social skills.

Psychosocial stressors of drug-abusing disadvantaged adolescent mothers.

The Problem Oriented Screening Instrument for Teenagers (POSIT) and the Beck Depression Inventory (BDI) were administered to 55 disadvantaged adolescent mothers who abused drugs during pregnancy and 49 nondrug-abusing disadvantaged adolescent mothers. Results suggested that the drug-abusing mothers were depressed (BDI = 14) while the nondrug-abusing mothers were nondepressed (BDI = 6). In addition, the drug-abusing mothers reported more mental and physical health problems, more problematic family and peer relationships, poorer social skills, more aggressive behavior, less constructive use of leisure time, and a lower educational and vocational status than did nondrug-abusing adolescent mothers. A multiple regression analysis of POSIT scales indicated that the best predictors of drug abuse during pregnancy were mental health status, leisure and recreational activities, and peer relationships. These results highlight the utility of administering the POSIT to identify stressors that place pregnant adolescents at risk for drug abuse.

PIP: A comparative study of 55 low-income adolescents who abused drugs or alcohol during pregnancy and 49 non-drug-abusing adolescent mothers of similar socioeconomic status revealed significantly more psychosocial stressors in the drug users. All study participants received obstetric care at an inner-city US teaching hospital. Inclusion criteria for the drug-abusing group included 15 or more alcoholic drinks, any marijuana use, or any cocaine use during pregnancy. Within 24 hours after delivery, respondents were administered a social history, the Beck Depression Inventory, the Paranoid-Borderline Features Scale, and the Problem Oriented Screening Instrument for Teenagers (POSIT). Drug-abusing mothers were significantly more depressed (p 0.001) than their non-drug-abusing counterparts and had less optimal scores on each component of the POSIT (substance use, physical health, mental health, family relations, peer relations, educational status, vocational status, social skills, leisure and recreation, and aggressive behavior). 40% of the variance in drug use was explained by three of these variables: mental health (30%), leisure and recreation (6%), and peer relationships (5%). It is unclear whether these stressors lead to, maintain, or are a consequence of drug abuse. The POSIT scales correctly classified 75% of the drug-abusing and 84% of the non-drug-abusing teen mothers, suggesting its potential use as a screening instrument for identifying at-risk pregnant adolescents.

Association of fake-good MMPI-2 profiles with low Beck Depression Inventory scores.

Seventy-nine adolescent mothers (mean age = 18.1 years) were administered the Beck Depression Inventory (BDI) and three validity scales (L, F, and K) of the Minnesota Multiphasic Personality Inventory 2 (MMPI-2). The aim was to determine whether low-BDI mothers were "faking good," or denying their depression. The adolescent mothers were assigned to a low-BDI group (scores = 0, 1, 2), a nondepressed group (scores = 3-9), or a depressed group (scores > or = 13). The depressed group had higher F (Symptom) scale scores than did the nondepressed group, which in turn had higher scores than did the low-BDI group. The low-BDI group, in contrast, had more fake-good profiles than did the two other groups. Discriminant analyses indicated that 90% of the fake-good profiles could be classified correctly based on BDI and K (Defensiveness) scale scores. These data suggest the need for further assessment when individuals have extremely low BDI scores.

Targeting adolescent mothers with depressive symptoms for early intervention.

Infants of mothers with depressive symptoms show developmental delays if symptoms persist over the first 6 months of the infant's life, thus highlighting the importance of identifying those mothers for early intervention. In Study 1, mothers with depressive symptoms (n = 160) and mothers without depressive symptoms (n = 100) and their infants were monitored to identify variables from the first 3 months that predict which mothers would still be symptomatic at 6 months. A "dysregulation" profile was noted for the infants of depressed mothers, including lower Brazelton scores, more indeterminate sleep, and elevated norepinephrine, epinephrine, and dopamine levels at the neonatal period, and greater right frontal EEG activation, lower vagal tone, and negative interactions at the 3- and 6-month periods. A group of maternal variables from the neonatal and 3-month assessments accounted for 51% of the variance in the mothers' continuing depressive symptoms. These variables included greater right frontal EEG activation, lower vagal tone, and less positive interactions at 3 months, and elevated norepinephrine, serotonin, and cortisol levels at the neonatal stage. In Study 2, a similar sample of mothers with depressive symptoms (n = 160) and without depressive symptoms (n = 100) was recruited and followed to 3 months. Those symptomatic mothers who had values above (or below) the median (depending on the negative direction) on the predictor variables identified in Study 1 (taken from the first 3 months) were then randomly assigned to an intervention or a control group at 3 months. These groups were then compared with each other, as well as with the group without depressive symptoms, at 6 and 12 months. The intervention, conducted from 3 to 6 months, consisted of free day care for the infants and a rehab program (social, educational, and vocational) plus several mood induction interventions for the mothers, including relaxation therapy, music mood induction, massage therapy, and mother-infant interaction coaching. Although the mothers who received the intervention continued to have more depressive symptoms than did the nondepressed mothers, their interactions significantly improved and their biochemical values and vagal tone normalized. Their infants also showed more positive interations, better growth, fewer pediatric complications, and normalized biochemical values, and by 12 months their mental and motor scores were better than those of the infants in the control group.

Polydrug-using adolescent mothers and their infants receiving early intervention.

This study investigated the effects of an intervention for polydrug-using adolescent mothers. The program included educational, vocational, and parenting classes; social and drug rehab; and day care for their infants while they attended school half-day. The drug-exposed infants were similar to the nonexposed infants on traditional birth measures, although they had inferior Brazelton Neonatal Behavioral Assessment Scale scores, including habituation, orientation, abnormal reflexes, general irritability, and regulatory capacity. The drug-exposed infants also spent less time in quiet sleep and more time crying and showing stress behaviors. Both the mothers and the infants in the drug groups demonstrated inferior interactions, and their dopamine and serotonin levels were significantly higher. As early as 3 months (following 3 months of intervention), the drug rehab mothers and their infants looked more like the nondrug group in their interactions; by 6 months, they looked similar on virtually every measure. At 12 months, the infants of drug rehab mothers (versus the drug control group) had superior Early Social Communication Scale scores and Bayley Mental scale scores, as well as significantly greater head circumference and fewer pediatric complications. The drug rehab mothers also improved on several lifestyle variables. They demonstrated a lower incidence of continued drug use and repeat pregnancy, and a greater number continued school, received a high school or general equivalency diploma, or were placed in a job. Thus, a relatively cost-effective high school based intervention had positive effects on both adolescent mothers who had used drugs and their infants.

PIP: The impact of an early childhood intervention program on polydrug-abusing US adolescent mothers and their infants was evaluated. The program, which was located in a vocational school attended by the mothers, included drug rehabilitation, social skills training, parenting classes, job training, and relaxation therapy. Outcomes in 126 drug-exposed mothers 16-21 years of age who participated in the program were compared to those recorded among non-drug-using adolescent mothers who participated in the program and drug-using control mothers who did not participate. All three groups were similar in terms of age, education, socioeconomic status, and ethnicity, but drug-abusing mothers had higher rates of depression and stress. At baseline, drug-exposed infants had lower scores on the measures of habituation, orientation, abnormal reflexes, general irritability, and regulatory capacity on the Neonatal Behavioral Assessment Scale. Drug-exposed infants spent less time sleeping and more time crying and showing stress behaviors. The drug groups also had lower Optimal Interaction Rating Scale scores for both mothers and infants. Their dopamine and serotonin levels were higher than those recorded among non-drug-using mothers and their cortisol levels were lower. However, after 6 months of participation in the intervention program, the drug-using mothers had Beck Depression Inventory scores and interaction ratings that approached those of non-drug-using mothers and exceeded those among drug-using controls. Similar trends were observed for infants' head circumference and scores on the Early Social Communication Scale and the Bayley Mental Status Scale. Moreover, drug-using adolescent mothers who participated in the program demonstrated a lower incidence of repeat pregnancy and continued drug use than those who were not enrolled in the program; moreover, they were more likely to receive their high school diploma and be placed in jobs. Interventions such as this have the potential to attenuate the developmental delays of infants of drug-exposed adolescents.

Morphology, ionic diffusion and applicability of novel polymer gel electrolytes with LiI/I2.

Novel polymer gel electrolytes have been prepared by incorporating LiI-I(2) solutions into a polyethylene oxide matrix supported by a TiO(2) filler. The gel electrolytes, based on either acetonitrile or propylene carbonate solvents are compared with liquid standard ones and are examined by (7)Li solid state nuclear magnetic resonance relaxometry and diffusion measurements. In parallel, the triiodide apparent diffusion coefficient has been determined by linear sweep voltammetry. The results are correlated with atomic force microscopic images of the electrolytes and give insight of the dynamic properties of the ions in the constrained polymer medium. Furthermore, the dissociation of the ions is estimated by relating the ionic conductivity to the ionic diffusion. As a prime application, the polymer gel electrolytes were incorporated in dye sensitized solar cells and the measured energy conversion efficiencies were successfully correlated with their morphological, diffusive and conducting properties.

Application of a picrolonate ion-selective electrode to the assay of calcium and piperazine in pharmaceuticals and serum.

The construction and some analytical applications of a liquid picrolonate (Picrl-) ion-selective electrode based on the tris(phenanthrolinato)iron(II) (ferroin) picrolonate salt, dissolved in 2-nitrotoluene, are described. The liquid membrane electrode exhibits a rapid and almost Nernstian response to picrolonate anions in the concentration range from 5 x 10(-2) to 5 x 10(-2) mol l-1. The response is virtually unaffected by pH changes in the range 3-10. Major interferents are picrates, 4-nitrophenolates, 3,5-dinitrosalicylates and 2,4-dinitrophenolates. In analytical applications direct potentiometric methods for the determination of picrolonates and indirect methods for the determination of calcium and piperazine are described. Calcium in the ranges 4-24 and 50-90 mg l-1, under specified experimental conditions, can be determined with mean relative errors of 1.1 and 1.4%, respectively. The method is applicable to soluble samples, pharmaceuticals and industrial and real human serum. Piperazine in the ranges 1-10 and 13-20 mg can be determined with a mean relative error of 1.2% in soluble salts and pharmaceutical formulations, respectively. An accuracy of better than 1.5% and a reproducibility (relative standard deviation) of 0.1% were achieved in the analysis of pharmaceutical products.

Upgrade of a semi-automatic flow injection analysis system to a fully automatic one by means of a resident program.

The program and the arrangement for a versatile, computer-controlled flow injection analysis system is described. A resident program (which can be run simultaneously and complementary to any other program) controls (on/off, speed, direction) a pump and a pneumatic valve (emptying and filling position). The system was designed to be simple and flexible for both research and routine work.

Mothers touching newborns: a comparison of rooming-in versus minimal contact.

We compared the maternal behaviors of women who had extended and early contact (rooming-in) with their infants with those who had contact only during feedings. Thirty-one young, unmarried, predominantly black, lower-socioeconomic mothers and their infants were observed in the mother's hospital room for 15 minutes after a morning feeding approximately 18 hours after delivery. A time sample unit checklist was used to record each mother's behavior, looking, talking, and touching directed toward their infants and others, as well as watching television and talking on the telephone. Analyses of variance revealed that the rooming-in mothers looked at, talked to, and touched their infants more, watched less television, and talked less on the telephone than mothers with minimal contact with their infants. These findings suggest that increased postpartum contact with infants leads not only to more interaction, but also to more touching as well as touching in more intimate places (face and head), thus highlighting the value of rooming-in arrangements for mothers and infants.

Bioelectrochemical determination of citric acid in real samples using a fully automated flow injection manifold.

An enzymic method for the determination of citric acid in fruits, juices and sport drinks is proposed. The method is based on the action of the enzymes citrate lyase, oxaloacetate decarboxylase and pyruvate oxidase, which convert citric acid into H2O2 with the latter being monitored amperometrically with a H2O2 probe. The enzymes pyruvate oxidase and oxaloacetate decarboxylase were immobilized. A multi-membrane system, consisting of a cellulose acetate membrane for the elimination of interferants, an enzymic membrane and a protective polycarbonate membrane were placed on a Pt electrode and used with a fully automated flow injection manifold. Several parameters were optimized, resulting in a readily constructed and reproducible biosensor. Interference from various compounds present in real samples was minimized. Calibration graphs were linear over the range 0.01-0.9 mM pyruvate, 0.015-0.6 mM oxaloacetate and 0.015-0.5 mM citrate. The throughput was 30 samples h-1 with an RSD of 1.0% (n = 8); the mean relative error was 2.4% compared with a standard method. The recovery was 96-104%. A 8-10% loss of the initial activity of the sensor was observed after 100-120 injections.

Electrocatalysis of sulphide with a cellulose acetate film bearing 2,6-dichlorophenolindophenol. Application to sewage using a fully automated flow injection manifold.

The application of an electrochemical sensor, based on a glassy carbon electrode, modified with a cellulose acetate polymeric film bearing 2,6-dichlorophenolindophenol (CA/DCPI-CME), for flow injection analysis of sulphide, is described. The overall reaction was found to obey a catalytic regeneration mechanism (EC mechanism) and the electrochemical rate constant k(f) for the electrocatalytic oxidation of sulphide was evaluated. The modified electrodes were mounted in a flow-injection manifold, poised at +0.08 mV versus Ag/AgCl/3 M KCl at pH 7.25 and utilised for the determination of sulphide in urban waste samples. The proposed method correlates well with a colorimetric method. Parameters such as working pH, sample size, flow rate and temperature were studied. Interferants of various compounds normally present in real samples were also tested. Calibration graphs were linear over the range 0.02-1 mM sodium sulphide for CA/DCPI-CMEs hydrolysed in KOH for 6 min. The throughput was 25 samples per h and the R.S.D. was 1.2% (n=7) for 0.1 mM sodium sulphide. Recoveries for spiked urban waste samples ranged from 99 to 120%. The sensor remained active for more than 2 weeks under specified conditions.