Результаты поиска

Intramolecular conversion of pentaaquahydroperoxidochromium(III) ion to aqueous chromium(V): potential source of carcinogenic forms of chromium in aerobic organisms.

The decomposition of the title compound (H(2)O)(5)CrOOH(2+) (hereafter Cr(aq)OOH(2+)) in acidic aqueous solutions is kinetically complex and generates mixtures of products (Cr(aq)(3+), HCrO(4)(-), H(2)O(2), and O(2)). Relative yields of individual products vary greatly with reaction conditions and initial concentrations of Cr(aq)OOH(2+). At pH 5.5 in the presence of O(2), the reaction was complete in less than a minute and generated chromate in about 70% yield. These findings, in addition to poor reproducibility of kinetic data, are indicative of the involvement of one or more reactive interme

Effect of the supporting electrolyte anion on the thickness of PSS/PAH multilayer films and on their permeability to an electroactive probe.

Quartz crystal microbalance and cyclic voltammetry are used to investigate the influence of the supporting salt of polyelectrolyte solutions on the buildup and the structure of PSS/PAH polyelectrolyte multilayers (PSS: poly(4-styrene sulfonate); PAH: poly(allylamine hydrochloride)). This film constitutes a model polyelectrolyte multilayer system. The supporting electrolytes were sodium salts where the nature of the anion was changed by following the Hofmeister series from cosmotropic to chaotropic anions (F-, Cl-, NO3-, ClO4-). For all the investigated anions, the film thickness increases line

Nutritional and antioxidant profile of the Physalis fruit grown in three Andean regions of Peru.

BACKGROUND: Physalis peruviana L. fruit contains nutritional and bioactive compounds of immense importance to public health and represents a potential ingredient for the development of functional foods and beverages. OBJECTIVE: This study aimed to determine the chemical and nutritional composition as well as the antioxidant capacity of the P. peruviana L. fruit grown in Peru in three areas of the Central Andean region. MATERIAL AND METHODS: Proximal and physicochemical analyses and estimation of mineral content, vitamin C, total carotenoids, total polyphenols, and antioxidant capacity (2, 2-

Perfluorobutanesulfonate exposure induces metabolic disturbances in different regions of mouse gut.

Perfluorobutanesulfonate (PFBS), an alternative to perfluorooctanesulfonate (PFOS), has raised many health concerns. However, PFBS toxicity in the mammalian gut remains unclear. C57BL/6 mice were exposed to 10 μg/L and 500 μg/L PFBS or 500 μg/L PFOS in their water supply for 28 days. PFBS toxicity in the ileum and colon was explored and compared to that of PFOS. Biochemical analysis showed that tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels increased in the ileum exposed to 10 μg/L PFBS, whereas no significant changes were observed in those levels in the colon. Catalase (CAT

Sulfonylmethanesulfonamide inhibitors of carbonic anhydrase.

A series of sulfonylmethanesulfonamide derivatives is described, which are inhibitors of carbonic anhydrase (CA). The most potent of these is the racemic fluoro sulfone 9, which inhibits carbon dioxide hydration catalyzed by human CA II (CA-II) with an IC50 of 3 nM. Binding competition studies versus dansylamide indicate that the enantiomers of 9 have different affinities for CA-II, with equilibrium dissociation constants of 3.6 and 0.6 nM. QSAR analysis suggests that the key factors involved in achieving high affinity in this series are sulfonamide acidity, hydrophobicity, and minimization of

Sensitive high-performance liquid chromatographic method for the determination of chlorhexidine in human serum and urine.

A high-performance liquid chromatographic method for the analysis of chlorhexidine in human serum and urine was developed. Chlorhexidine and the internal standard, chlorpheniramine, were extracted into chloroform, containing 5% 2-propanol, and back-extracted into dilute sulfuric acid. Chromatographic separation was achieved on a C18 column equilibrated with methanol-water (70:30, v/v), containing 0.005 M sodium heptane-sulfonate. The sensitivity of the assay was 20 ng/ml of biological matrix, using 0.5-ml samples. The application of this method to monitor chlorhexidine levels in burn patients

Hydrophobic corn zein-modified cellulose nanofibril (CNF) films with antioxidant properties.

Cellulose nanofibrils (CNFs) can form strong biodegradable films; however, due to their hydrophilicity, moisture can degrade their mechanical and barrier properties. Corn zein (CZ) is a hydrophobic protein that when covalently linked with CNF films through peptide bonds, may improve their hydrophobicity. CZ was covalently linked to aminophenylacetic acid and aminobenzoic acid esterified CNF films which were then assessed for evidence of modification, hydrophobicity, mechanical properties, and antioxidant activity. Upon modification, an increase in hydrophobicity and an increase in antioxidant

Final report on the safety assessment of octoxynol-1, octoxynol-3, octoxynol-5, octoxynol-6, octoxynol-7, octoxynol-8, octoxynol-9, octoxynol-10, octoxynol-11, octoxynol-12, octoxynol-13, octoxynol-16, octoxynol-20, octoxynol-25, octoxynol-30, octoxynol-33, octoxynol-40, octoxynol-70, octoxynol-9 carboxylic acid, octoxynol-20 carboxylic acid, potassium octoxynol-12 phosphate, sodium octoxynol-2 ethane sulfonate, sodium octoxynol-2 sulfate, sodium octoxynol-6 sulfate, and sodium octoxynol-9 sulfate.

Octoxynols are ethoxylated alkylphenols in which the size of the molecule is related to the number of moles of ethylene oxide used in synthesis. Reactions are performed at elevated temperature, under pressure, and in the presence of NaOH. It is possible that the synthesis may leave trace amounts of ethylene oxide, 1,4-dioxane, and unreacted C9 phenols. Octoxynols of various chain lengths as well as octoxynol salts and organic acids function in cosmetics either as surfactants--emulsifying agents, surfactants--cleansing agents, surfactant--solubilizing agents, or surfactants--hydrotropes in a wi

Объединения ПФАС и ОХ-ПХБ с риском множественных склерозов и ухудшения состояния здоровья.

Воздействие перфторированных и полифторированных веществ (ПФАС) и гидроксилированных полихлорированных дифенилов (ОН-ПХД) связано с неблагоприятным воздействием на здоровье человека, включая иммунодепрессию. Неизвестно, могут ли эти вещества повлиять на аутоиммунные заболевания. Это исследование было основано на данных о 907 лицах с множественным склерозом (MS) и 907 совпадающих контрольных устройствах, в ходе которых за случаями применения MS велось продольное наблюдение с использованием шведского регистра MS. Мы демонстрируем различия по признаку пола и заболевания в концентрациях сыворотки

Совпадение в полном тексте источника
… Within perfluoroalkyl sulfonic acids, long-chain PFAS contains six or more carbons, and short-chain contains less than six. In perfluoroalkyl carboxylic acids, however, long-chain PFAS contains seven or more fluorinated carbons, and short-chain has less than seven 79 , 80 . …

The Relationship Between Perfluoroalkyl Substances Concentrations and Thyroid Function in Early Childhood: A Prospective Cohort Study.

Background: Exposure to perfluoroalkyl substances (PFAS) has been suggested to affect thyroid function; however, data on early-life exposure and thyroid function in early childhood are scarce. We investigated the cross-sectional and longitudinal relationships of early-life exposure to PFAS with thyroid function at 2, 4, and 6 years of age. Methods: This study used data on PFAS exposure and thyroid function from the Environment and Development of Children (EDC) cohort study. A total of 660 children who visited at least once at 2, 4, or 6 years of age (381 children aged 2 years, 569 children age

A synergistic strategy of dual-crosslinking and loading intelligent nanogels for enhancing anti-coagulation, pro-endothelialization and anti-calcification properties in bioprosthetic heart valves.

Currently, glutaraldehyde (GA)-crosslinked bioprosthetic heart valves (BHVs) still do not guarantee good biocompatibility and long-term effective durability for clinical application due to their subacute thrombus, inflammation, calcification, tearing and limited durability. In this study, double-modified xanthan gum (oxidized/vinylated xanthan gum (O2CXG)) was acquired from xanthan gum for subsequent double crosslinking and modification platform construction. Sulfonic acid groups with anticoagulant properties were also introduced through the free radical polymerization of vinyl sulfonate (VS)

Synthesis and Characterization of Biodegradable Terpolymer Scale Inhibitors.

To address scaling issues in oilfield water injection, a degradable terpolymer scale inhibitor MA-AA-AMPS (terpolymer)was synthesized via aqueous solution polymerization using maleic anhydride, acrylic acid, and 2-acrylamido-2-methylpropanesulfonic acid as monomers. Characterization confirmed the presence of carboxyl, sulfonic, and amide groups in the copolymer with good thermal stability. Scale inhibition tests showed that at 2% dosage, its scale inhibition efficiency exceeded 80%, remaining above 80% in the pH range of 3-8 and over 50% at 150 °C, with excellent tolerance to high-calcium envi

Nontuberculous mycobacterial pulmonary disease caused by Mycobacterium seoulense.

Mycobacterium seoulense was first isolated and reported in Korea in 2007. We report a rare case of nontuberculous mycobacterial (NTM) pulmonary disease caused by M. seoulense. A woman in her mid-90s was referred to our hospital due to bloody sputum. She had medical histories of chronic heart failure and chemoradiotherapy for right small cell lung carcinoma. Chest computed tomography showed a consolidation on the mediastinal side of the right lung following radiotherapy and nodules with bronchiectasis of the right upper and middle lobes. Acid-fast culture tests of sputum were positive for M. se

The metabolism of methazolamide - identification of metabolites in guinea pig urine.

The in vivo metabolism of methazolamide, a carbonic anhydrase inhibitor, was studied using guinea pigs as the animals. (14)C-Labeled methazolamide was synthesized. Eighty percent of intraperitoneally injected radioactivity was recovered from urine and feces within 24 hours. HPLC analysis on a C(18) column detected 2 radioactive metabolites (Peaks A and B). The Peaks A and B were isolated from the urine of the animals dosed with non-radioactive methazolamide.They were purified on the C(18) column. Their chemical structure was revealed by UV-absorbance spect a and LC/MS, and confirmed by compari

Simultaneous determination of L-693,612, a topical carbonic anhydrase inhibitor, and two potential metabolites in human whole blood by ion-pair high-performance liquid chromatography.

A method for the simultaneous determination of a topical carbonic anhydrase inhibitor, L-693,612, and two of its potential metabolites in human whole blood is described. The analytes are isolated from the matrix via liquid-liquid extraction with a mixture of toluene, ethyl acetate and isopropanol (49:50:1, v/v/v). The analytes are then back extracted into dilute phosphoric acid prior to injection into the HPLC system. A cyano column (Zorbax SB-CN, 150 x 4.6 mm) with a mobile phase of phosphoric acid(0.085%)-acetonitrile (73.5:26.5) containing 10 mM sodium decane sulfonate and adjusted to pH 3

Rapid method for simultaneous determination of ascorbic acid and zinc in effervescent tablets by capillary zone electrophoresis with contactless conductivity detection.

Ascorbic acid and zinc are essential nutrients that play important roles in nutrition, immune support, and maintenance of health. For this reason, both compounds are widely used as ingredients in dietary supplements. We report, for the first time, an analytical method for fast simultaneous determination of ascorbic acid and zinc. A single analysis run is possible every 80 s (45 injections/h). The method is based on capillary electrophoresis with capacitively coupled contactless conductivity detection using a fused silica capillary with 50 cm length (effective length of 10 cm). The separation w

Tissue content of thiol-containing amino acids predicts methylmercury in aquatic invertebrates.

Aquatic invertebrates vary in methylmercury (MeHg) levels among systems which has been attributed, in part, to environmental conditions, but may also be linked to differences in their biochemical composition. As MeHg is known to bind to thiol-containing amino acids such as cysteine in proteins of fish, our objective was to determine if these amino acids explain MeHg variability among aquatic invertebrate taxa. Benthic macroinvertebrates from diverse functional feeding groups and bulk zooplankton were collected from six acidic lakes in Kejimkujik National Park, Nova Scotia, Canada, and analyzed

Biotransformation of Acetaminophen in Rice Phyllosphere: Xenobiotic-Plant-Microbiota Interactions.

The biotransformation of acetaminophen, a pharmaceutical contaminant widely found in crop produce, in the rice phyllosphere highlights critical xenobiotic-plant-microbiota interactions. This study investigated acetaminophen uptake, translocation, and transformation in hydroponically exposed rice shoots, revealing accumulation at 8.33 ± 0.82 μg/g and conversion into hydroxylated, glycosylated, methylated, thiomethylated, sulfonated, dimerized, and amino acid-conjugated derivatives. Specifically, these transformations may be driven by plant enzymes (cytochrome P450, glycosyltransferases, sulfotr

Enantioselective synthesis of silicon-stereogenic sulfur-containing silanes via organocatalytic remote C-H sulfenylation of arenes.

In this study, we report a remote C-H sulfenylation of 5,10-dihydrophenazasilines enabled by a cooperative catalytic system comprising a chiral Lewis base and an achiral Brønsted acid for the first time. The synergistic use of a chiral phosphoric triamide sulfide catalyst featuring a bis((S)-1-phenylpropyl)amine structural motif and an achiral sulfonic acid co-catalyst with precisely tuned acidity is essential for achieving efficient remote stereocontrol. This methodology provides efficient access to chiral silicon-stereogenic sulfur-containing organosilanes. A broad substrate scope is demonst