Wide band gap Ga2O3 as efficient UV-C photocatalyst for gas-phase degradation applications.

α, ß, γ, and δ polymorphs of 4.6-4.8 eV wide band gap Ga2O3 photocatalysts were prepared via a soft chemistry route. Their photocatalytic activity under 254 nm UV-C light in the degradation of gaseous toluene was strongly depending on the polymorph phase. α- and ß-Ga2O3 photocatalysts enabled achieving high and stable conversions of toluene with selectivities to CO2 within the 50-90% range, by contrast to conventional TiO2 photocatalysts that fully deactivate very rapidly on stream in similar operating conditions with rather no CO2 production, no matter whether UV-A or UV-C light was used. The highest performances were achieved on the high specific surface area ß-Ga2O3 photocatalyst synthesized by adding polyethylene glycol (PEG) as porogen before precipitation, with stable toluene conversion and mineralization rate into CO2 strongly overcoming those obtained on commercial ß-Ga2O3. They were attributed to favorable physicochemical properties in terms of high specific surface area, small mean crystallite size, good crystallinity, high pore volume with large size mesopore distribution and appropriate surface acidity, and to the possible existence of a double local internal field within Ga3+ units. In the degradation of hydrogen sulfide, PEG-derived ß-Ga2O3 takes advantage from its high specific surface area for storing sulfate, and thus for increasing its resistance to deactivation and the duration at total sulfur removal when compared to other ß-Ga2O3 photocatalysts. So, we illustrated the interest of using high surface area ß-Ga2O3 in environmental photocatalysis for gas-phase depollution applications.

Pre- and postnatal exposure of children to tobacco smoke during the first four years of life--observations of the authors.

INTRODUCTION: Environmental exposure to tobacco smoke is a significant threat for human health, where the higher is its degree, the more immature the human organism is. Therefore, the exposure to Tobacco smoke in foetal life exerts unfavourable effects on developing foetus and may cause early and distant results in children. MATERIAL AND METHODS: The study comprised 318 children in their first four years of life, treated for various medical conditions. The examined children were divided into two groups, Group 1--children exposed to Tobacco smoke--and Group 2--a control group with children from non-smoking families. History data were obtained on the basis of a specially designed questionnaire, used by the doctor in an individual conversation with parent. In each third child from the group 1 cotinine concentration in urine was assayed by the method of high performance liquid chromatography-UV-VIS and the cotinine/creatinine ratio was calculated. RESULTS OF STUDY: Results demonstrated environmental exposure to tobacco smoke in 173 children (Group 1). Out of them 31.2% were the children whose mothers had smoked also during pregnancy (Subgroup A). The other 119 children from Group 1 were accounted to Subgroup B, i.e., children, where other household members had been smoking cigarettes. A comparative group comprised 143 children from non-smoking families. The results demonstrated then that 17% of all the examined children were those, exposed to tobacco smoke effects already in their foetal life, predisposing them to prematurity and low birth weight. Moreover, it was observed that the young age and lower education level of their parents, together with worse housing conditions, may suggest a predisposing character and role of the mentioned factors.

Electrochemical, Photochemical, and Photoelectrochemical Treatment of Sodium p -Cumenesulfonate.

The degradation of sodium p-cumenesulfonate (SCS) by electrochemical, photochemical, and photoelectrochemical methods in aqueous solution of NaClO4, NaCl, and NaClO has been studied. It was found that as a result of NaClO4 electroreduction and photodecomposition, the ions Cl- and ClO3- are formed. These ions undergo transformations into radicals, mainly Cl•, Cl2•-, ClO•-, ClO2•-, and ClO3•-, due to electrochemical and photochemical reactions. It was shown that the interpretation of results of the studies over mineralization processes carried out in the presence of ClO4- cannot be adequate without taking into consideration the reduction of ClO4- to Cl- and ClO3-. Therefore, previous works presented in the literature should be rediscussed on the basis of the new data. Photoelectrochemical mineralization of substrate in NaCl solution at the concentration of 16 mmol L-1 is comparable with the efficiency of the reaction in NaClO4 solution containing more than 8 mmol L-1 of NaClO. Total SCS mineralization was obtained in the photoelectrochemical reactor with a UV immersion lamp with a power 15 W in the period of 135 min and current intensity of 350 mA. In such conditions, the power consumption was about 1.2 kWh per g of TOC removed.

A focus on homocysteine in autism.

Homocysteine is an amino acid, which plays several important roles in human physiology. A wide range of disorders, including neuropsychiatric disorders and autism, are associated with increased homocysteine levels in biological fluids. Various B vitamins: B6 (pyridoxine), B12 (cobalamin), and B9 (folic acid) are required as co-factors by the enzymes involved in homocysteine metabolism. Therefore, monitoring of homocysteine levels in body fluids of autistic children can provide information on genetic and physiological diseases, improper lifestyle (including dietary habits), as well as a variety of pathological conditions. This review presents information on homocysteine metabolism, determination of homocysteine in biological fluids, and shows abnormalities in the levels of homocysteine in the body fluids of autistic children.

Chromatographic methods in the study of autism.

Research into biomarkers of autism is a new means of medical intervention in this disease. Chromatographic techniques, especially coupled with mass spectrometry, are widely used in determination of biomarkers and assessment of effectiveness of autism therapy owing to their sensitivity and selectivity. Among the chromatographic techniques gas chromatography and liquid chromatography, especially high-performance liquid chromatography, have found application in clinical trials. The high-performance liquid chromatography technique allows an analysis of liquid samples with a wide range of molecules, small and large, providing an opportunity to perform advanced assays within a short time frame. Gas chromatography with the appropriate preparation of samples (gaseous and liquid) and a selection of analysis conditions enables the separation of thermally stable, volatile and non-volatile organic substances in short runtimes. The chromatographic techniques that are currently used in metabolic studies in autism are designed to identify abnormalities in three areas: the metabolism of neurotransmitters, nutritional and metabolic status and manifestations of oxidative stress. This review presents a necessary theoretical introduction and examples of applications of chromatographic studies of disorder markers in autism.

B vitamin supplementation reduces excretion of urinary dicarboxylic acids in autistic children.

Urinary dicarboxylic acids are an important source of information about metabolism and potential problems especially connected with energy production, intestinal dysbiosis, and nutritional individuality in autistic children. A diet rich in vitamins and macroelements is a new idea of intervention in autism. The objective of the present study was to test the hypothesis that vitamin B2, vitamin B6, and magnesium supplementation is effective in reducing the level of dicarboxylic acids in the urine of autistic children. We examined the levels of succinic, adipic, and suberic acids in the urine of autistic children before and after vitamin supplementation. Thirty children with autism received magnesium (daily dose, 200 mg), vitamin B6 (pyridoxine; daily dose, 500 mg), and vitamin B2 (riboflavin; daily dose, 20 mg). The treatment was provided for a period of 3 months. Organic acids were determined using gas chromatography/mass spectrometry. Before supplementation, the levels of succinic, adipic, and suberic acids in the urine of autistic children were 41.47 ± 50.40 µmol/mmol creatinine, 15.61 ± 15.31 µmol/mmol creatinine, 8.02 ± 6.08 µmol/mmol creatinine; and after supplementation, the levels were 9.90 ± 8.26 µmol/mmol creatinine, 2.92 ± 2.41 µmol/mmol creatinine, and 2.57 ± 3.53 µmol/mmol creatinine, respectively. The results suggest that the supplementation reduces the level of dicarboxylic acid in the urine of autistic children.

Vitamin supplementation reduces the level of homocysteine in the urine of autistic children.

Significant differences in homocysteine levels in the urine of autistic children are observed. We hypothesized that vitamin supplementation might reduce the level of urinary homocysteine. To rationalize such a hypothesis, analyses were performed using the gas chromatography/mass spectrometry method. The homocysteine level in the urine of autistic children was measured twice: (1) before vitamin supplementation (group C, 30 autistic children) and (2) after supplementation, with either folic acid and vitamins B(6) and B(12) (group A1, 24 autistic children) or vitamins B(6) and B(12) alone (group A2, 6 autistic children). The homocysteine level in the urine of autistic children before vitamin supplementation was 2.41 ± 1.10 mmol/mol creatinine (mean ± SD difference). After treatment, the homocysteine level was reduced to 1.13 ± 0.44 and 1.33 ± 0.39 mmol/mol creatinine for A1 and A2 groups, respectively. The intake of vitamins B(6) and B(12), together with folic acid, was found to be more effective in lowering the levels of urinary homocysteine than the intake of vitamins B(6) and B(12) alone. Our findings may lead to the recommendation of including vitamins B(6) and B(12) together with folic acid supplementation in the diets of children with autism.

Homocysteine level in urine of autistic and healthy children.

Homocysteine is an amino acid which plays several important roles in human physiology and is an important biomarker for possible deficiencies of various vitamins (vitamin B6 and B12, folic acid). In this work GC-MS method was used to determine the levels of homocysteine in the urine of autistic and healthy children. The levels of homocysteine in urine samples from 34 autistic and 21 healthy children were 2.36 ± 1.24 and 0.76 ± 0.31 (mmol∙mol⁻¹ creatinine), respectively. The higher level of homocysteine in autistic children may indicate deficiencies of folic acid and vitamins B6 and B12 in nutrition of these children. The results of this work were taken into consideration in the nutrition of autistic children treated in the Navicula Centre of Diagnosis and Therapy of Autism in Lódz (Poland).

Determination of tryptophan in urine of autistic and healthy children by gas chromatography/mass spectrometry.

BACKGROUND: Tryptophan is an amino acid, which is responsible for the production of serotonin in the body. Lower levels of tryptophan may play a role in pediatric disorders. In this work the urinary level of tryptophan in autistic and healthy children was compared. MATERIAL/METHODS: The samples of urine were taken from 33 autistic children (10 on a restricted diet of gluten and casein free and 23 no diet) and 21 healthy children. The level of tryptophan was determined by gas chromatography/mass spectrometry (GC/MS). In this method tryptophan was derivatized and extracted simultaneously. The method was validated. RESULTS: Significantly lower relative urinary levels of tryptophan were obtained for both autistic children with a restricted diet 1.98±1.17 µg/mL (mean ±SD) and autistic children without a diet 7.44±1.33 µg/mL (mean ±SD) compared to healthy children 14.24±2.01 µg/mL (mean ±SD). The method has a limit of quantification (LOQ) of 0.15 µg/mL and a lower limit of detection (LOD) of 0.04 µg/mL for tryptophan in urine. CONCLUSIONS: This method is precise and sensitive for the detection of low concentrations of tryptophan and can be applicable to monitoring its level in human urine. Children with autism have a higher deficiency of tryptophan than the control group of healthy children. Lower levels of tryptophan may lead to the worsening of autistic symptoms such as mild depression and increased irritability.

Determination of homovanillic acid and vanillylmandelic acid in urine of autistic children by gas chromatography/mass spectrometry.

BACKGROUND: Studies suggest dopamine nervous systems are involved in the pathogenesis of autistic disorder. Quantification of urinary homovanillic acid (HVA) and vanillylmandelic acid (VMA) can be a very important tool in the study of disorders of dopamine metabolism in autistic children. MATERIAL/METHODS: The urine specimens were collected from 20 autistic children and 36 neurologically normal children. Urinary HVA and VMA were simultaneously analyzed by gas chromatography-mass spectrometry. The method involves extraction of HVA and VMA from urinary samples and derivatization to N,O-bis(trimethylsilyl)trifluoroacetamide derivatives. RESULTS: The detection limits are 0.15 microg/mL and 0.23 microg/mL for VMA and HVA, respectively. The levels of HVA and VMA were higher in the urine of autistic children (28.8+/-15.5 micromol/mmol creatinine and 22.2+/-13.0 micromol/mmol creatinine, respectively) compared with those of the generally healthy children (4.6+/-0.7 micromol/mmol creatinine for HVA and 3.8+/-0.6 micromol/mmol creatinine for VMA). CONCLUSIONS: We proposed a simple, rapid method for a routine analysis of human urine to detect HVA and VMA related to an abnormal functional imbalance of the dopamine system, and showed our experience of application of this method to patients with a diagnosis of autism spectrum disorders. These results suggest significant differences in the levels of HVA and VMA between autistic and healthy children.