A randomised controlled trial of oral zinc sulphate for primary dysmenorrhoea in adolescent females.

PubMed

Zekavat, Omid R; Karimi, Mohammad Y; Amanat, Aida; Alipour, Farzaneh

2015-08-01

Primary dysmenorrhoea, the most common gynaecologic problem of adolescent females, is commonly treated with nonsteroidal anti-inflammatory drugs or oral contraceptive pills. To compare the effect of zinc sulphate with that of placebo on the control of pain severity and duration in adolescent girls with primary dysmenorrhoea. In a three-month randomised double-blind placebo-controlled clinical trial, 120 adolescent females with primary dysmenorrhoea were randomly divided into two groups of sixty: an intervention group (zinc) and a control group (placebo). Zinc was administered in the form of a capsule containing 50 mg/day zinc sulphate beginning on the first day of menses and continuing until three days prior to the end of menses. Each month, the duration and severity of primary dysmenorrhoea were determined. Severity scoring was performed by using a 0-10 scaling system. In the first month, the duration of pain was significantly lower in the zinc group compared with the placebo group (P-value = 0.044), while there was no significant difference in pain severity between the groups (P-value = 0.497). In the second and third month, pain severity and duration in the zinc group were significantly lower than the placebo group (P-value <0.001). Both pain duration and pain severity were decreased by taking oral zinc. The results of our interventional study suggests that zinc may be used to treat primary dysmenorrhoea in adolescents. © 2015 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

Synthesis, structure and photoluminescence of (PLAGH){sub 2}[ZnCl{sub 4}] and comparative analysis of photoluminescence properties with tris(2,2′-bipyridine)ruthenium(II)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Radanović, Mirjana M.; Jelić, Miodrag G., E-mail: jelicmgm@uns.ac.rs; Romčević, Nebojša Ž.

Highlights: • New zinc(II) complex with pyridoxalaminoguanidine was synthesized. • The enhancement of the photoluminescence due to the compound formation was achieved. • Very high photoluminescence of Zn(II) compound was noticed. • Comparative analysis of photoluminescence with tris(2,2′-bipyridine) ruthenium(II) was provided. - Abstract: The first compound of zinc(II) containing pyridoxalaminoguanidine has been synthesized and characterized by elemental analysis, infrared spectra, conductometric measurements and X-ray crystallography. Single crystals of the compound were obtained in the reaction of methanolic solution of zinc(II) chloride and pyridoxalaminoguanidine hydrochloride. In this compound the coordination of chelate ligand is absent and tetrachlorido complex of zinc(II) withmore » pyridoxalaminuguanidinium cation as contraion is obtained. Photoluminescence spectra were measured. Lorentzian multipeak technique was used to determine peak wavelengths and their intensities. Photoluminescence spectroscopy upon 325, 488 and 514 nm laser excitation light was used to obtain results. This novel compound of zinc(II) was compared to the well-known organic light emitting diode material—ruthenium(II) complex with bypiridine i.e., tris(2,2′-bipyridine)ruthenium(II), under the same circumstances and the identical experimental setup. A scheme of energy levels and transitions is proposed to explain the obtained experimental results.« less

Habit modification of bis-thiourea zinc chloride (ZTC) semi organic crystals by impurities

NASA Astrophysics Data System (ADS)

Ruby Nirmala, L.; Thomas Joseph Prakash, J.

2013-06-01

Single crystals of bis-thiourea zinc chloride (ZTC) doped with metal ion (Li+) possess excellent nonlinear optical properties. These crystals were grown by slow evaporation solution growth technique. The effect of Li+ dopant on the growth and properties of ZTC single crystal were investigated and reported. The grown crystals were crystallized in orthorhombic structure with non-centro symmetric space group Pn21a through the parent compound. The amount of dopant incorporated in the parent crystal was revealed by the inductively coupled plasma (ICP-OES) studies. The FT-IR spectroscopy study was done for finding and confirming the functional groups present in the compound. The UV-Visible spectral study was carried out to find the optical behavior and transparency nature of the grown crystal. TG/DTA measurements and Vickers microhardness measurements were traced to find out the thermal and mechanical stability of the grown crystals respectively. Using Nd:YAG laser, the Second harmonic generation (SHG) for the grown crystals were confirmed.

Habit modification of bis-thiourea zinc chloride (ZTC) semi organic crystals by impurities.

PubMed

Ruby Nirmala, L; Thomas Joseph Prakash, J

2013-06-01

Single crystals of bis-thiourea zinc chloride (ZTC) doped with metal ion (Li(+)) possess excellent nonlinear optical properties. These crystals were grown by slow evaporation solution growth technique. The effect of Li(+) dopant on the growth and properties of ZTC single crystal were investigated and reported. The grown crystals were crystallized in orthorhombic structure with non-centro symmetric space group Pn21a through the parent compound. The amount of dopant incorporated in the parent crystal was revealed by the inductively coupled plasma (ICP-OES) studies. The FT-IR spectroscopy study was done for finding and confirming the functional groups present in the compound. The UV-Visible spectral study was carried out to find the optical behavior and transparency nature of the grown crystal. TG/DTA measurements and Vickers microhardness measurements were traced to find out the thermal and mechanical stability of the grown crystals respectively. Using Nd:YAG laser, the Second harmonic generation (SHG) for the grown crystals were confirmed. Copyright © 2013 Elsevier B.V. All rights reserved.

Formation and reduction of carcinogenic furan in various model systems containing food additives.

PubMed

Kim, Jin-Sil; Her, Jae-Young; Lee, Kwang-Geun

2015-12-15

The aim of this study was to analyse and reduce furan in various model systems. Furan model systems consisting of monosaccharides (0.5M glucose and ribose), amino acids (0.5M alanine and serine) and/or 1.0M ascorbic acid were heated at 121°C for 25 min. The effects of food additives (each 0.1M) such as metal ions (iron sulphate, magnesium sulphate, zinc sulphate and calcium sulphate), antioxidants (BHT and BHA), and sodium sulphite on the formation of furan were measured. The level of furan formed in the model systems was 6.8-527.3 ng/ml. The level of furan in the model systems of glucose/serine and glucose/alanine increased 7-674% when food additives were added. In contrast, the level of furan decreased by 18-51% in the Maillard reaction model systems that included ribose and alanine/serine with food additives except zinc sulphate. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparison and Analysis of Zinc and Cobalt-Based Systems as Catalytic Entities for the Hydration of Carbon Dioxide

PubMed Central

Lau, Edmond Y.; Wong, Sergio E.; Baker, Sarah E.; Bearinger, Jane P.; Koziol, Lucas; Valdez, Carlos A.; Satcher, Joseph H.; Aines, Roger D.; Lightstone, Felice C.

2013-01-01

In nature, the zinc metalloenzyme carbonic anhydrase II (CAII) efficiently catalyzes the conversion of carbon dioxide (CO2) to bicarbonate under physiological conditions. Many research efforts have been directed towards the development of small molecule mimetics that can facilitate this process and thus have a beneficial environmental impact, but these efforts have met very limited success. Herein, we undertook quantum mechanical calculations of four mimetics, 1,5,9-triazacyclododedacane, 1,4,7,10-tetraazacyclododedacane, tris(4,5-dimethyl-2-imidazolyl)phosphine, and tris(2-benzimidazolylmethyl)amine, in their complexed form either with the Zn2+ or the Co2+ ion and studied their reaction coordinate for CO2 hydration. These calculations demonstrated that the ability of the complex to maintain a tetrahedral geometry and bind bicarbonate in a unidentate manner were vital for the hydration reaction to proceed favorably. Furthermore, these calculations show that the catalytic activity of the examined zinc complexes was insensitive to coordination states for zinc, while coordination states above four were found to have an unfavorable effect on product release for the cobalt counterparts. PMID:23840420

Comparison and analysis of zinc and cobalt-based systems as catalytic entities for the hydration of carbon dioxide

DOE PAGES

Lau, E. Y.; Wong, S. E.; Baker, S. E.; ...

2013-06-20

In nature, the zinc metalloenzyme carbonic anhydrase II (CAII) efficiently catalyzes the conversion of carbon dioxide (CO 2) to bicarbonate under physiological conditions. Efforts have been directed towards the development of small molecule mimetics that can facilitate this process and thus have a beneficial environmental impact, but these efforts have met very limited success. Herein, we undertook quantum mechanical calculations of four mimetics, 1,5,9-triazacyclododedacane, 1,4,7,10-tetraazacyclododedacane, tris(4,5-dimethyl-2-imidazolyl)phosphine, and tris(2-benzimidazolylmethyl)amine, in their complexed form either with the Zn 2+ or the Co 2+ ion and studied their reaction coordinate for CO 2 hydration. These calculations demonstrated that the ability of the complexmore » to maintain a tetrahedral geometry and bind bicarbonate in a unidentate manner were vital for the hydration reaction to proceed favorably. Moreover, these calculations show that the catalytic activity of the examined zinc complexes was insensitive to coordination states for zinc, while coordination states above four were found to have an unfavorable effect on product release for the cobalt counterparts.« less

Studies on the synthesis, spectral, optical and thermal properties of l-Valine Zinc Sulphate: an organic inorganic hybrid nonlinear optical crystal.

PubMed

Puhal Raj, A; Ramachandra Raja, C

2012-11-01

Nonlinear optical (NLO) organic inorganic hybrid l-Valine Zinc Sulphate (LVZS) was synthesized and single crystals were obtained from saturated aqueous solution by slow evaporation method at 36°C using a constant temperature bath (CTB) with an accuracy of ±0.01°C. This crystal is reported with its characterization by single crystal and powder XRD, FTIR, UV-Vis-NIR, TG/DTA analysis and SHG test. Single crystal XRD study reveals that LVZS crystallizes in monoclinic system with the lattice constants a=9.969(3) Å, b=7.238(3) Å, c=24.334(9) Å and cell volume is 1736.00Å(3). Sharp peaks observed in powder X-ray diffraction studies confirm the high degree of crystallinity of grown crystal. The incorporation of sulphate ion with l-valine is confirmed by FTIR spectrum in LVZS crystal(.) A remarkable increase in optical transparency has been observed in LVZS when compared to l-valine and zinc sulphate heptahydrate Thermal properties of LVZS have been reported by using TG/DTA analysis. Kurtz powder second harmonic generation (SHG) test confirms NLO property of the crystal and SHG efficiency of LVZS was found to be 1.34 times more than pure l-valine. Copyright © 2012 Elsevier B.V. All rights reserved.

Structure and optical properties of ZnO produced from microwave hydrothermal hydrolysis of tris(ethylenediamine)zinc nitrate complex

NASA Astrophysics Data System (ADS)

Mostafa, Nasser Y.; Heiba, Zein K.; Ibrahim, Mohamed M.

2015-01-01

ZnO powders were synthesized using a solution microwave hydrothermal hydrolysis process and tris(ethylenediamine)zinc nitrate {[Zn(en)3](NO3)2} (en = ethylenediamine) as a precursor. Hydrolysis of the precursor complex at different pH produced zinc oxide with a diversity of well-defined morphologies. The effect of hydrolysis pH values on the structural and optical properties has been explored using XRD, SEM, and UV-visible diffuse reflectance spectroscopy (DRS). At pH = 7.0, randomly dispersed rods were formed. Whereas flower-like morphologies were obtained by treating the complex precursor in water at pH = 10.0 and 12.0. The ZnO4 tetrahedrons are greatly affected by the pH value. The band gap decreased sharply with increasing the pH value from 7.0 to 10.0, then slightly decreased with further increasing the pH to 12.0. The relationship between band gap and both structure and surface defects of the samples is also discussed.

Suppression of chlorinated aromatics by nitrogen and sulphur inhibitors in iron ore sintering.

PubMed

Zhang, Yadi; Buekens, Alfons; Liu, Lina; Zhang, Yibo; Zeng, Xiaolan; Sun, Yifei

2016-07-01

Dioxins generated by iron and steel industry account for the majority of industrial dioxins emissions. This study compares the performance of different additives (including calcium sulphate dehydrate CaSO4·2H2O; calcium polysulphide CaSx; ammonium sulphate (NH4)2SO4; 4-methylthiosemicarbazide H3C-SC(NH)2NH2 and thiourea H2NCSNH2) as suppressant of chlorinated aromatics in iron ore sintering. The formation of chlorobenzenes (CBz) and polychlorinated biphenyls (PCBs), used as surrogates for dioxins, was suppressed significantly in the present of various inhibitors (1 wt%) except for CaSO4·2H2O. Moreover, a larger molar ratio of (S + N)/Cl leads to a higher suppression efficiency, so that the inhibition capacity of (NH4)2SO4 on both CBz and PCBs was weaker than H2NCSNH2. The generation of dioxin-like PCBs (Co- or dl-PCB) was also analysed. Copyright © 2016 Elsevier Ltd. All rights reserved.

GATA4-mediated cardiac hypertrophy induced by D-myo-inositol 1,4,5-tris-phosphate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu Zhiming; Zhu Shanjun; Liu Daoyan

2005-12-16

We evaluated the effects of D-myo-inositol 1,4,5-tris-phosphate on cardiac hypertrophy. D-myo-inositol 1,4,5-tris-phosphate augmented cardiac hypertrophy as evidenced by its effects on DNA synthesis, protein synthesis, and expression of immediate-early genes c-myc and c-fos, {beta}-myosin heavy chain, and {alpha}-actin. The administration of D-myo-inositol 1,4,5-tris-phosphate increased the expression of nuclear factor of activated T-cells and cardiac-restricted zinc finger transcription factor (GATA4). Real-time quantitative RT-PCR showed that D-myo-inositol 1,4,5-tris-phosphate-induced GATA4 mRNA was significantly enhanced even in the presence of the calcineurin inhibitor, cyclosporine A. The effect of D-myo-inositol 1,4,5-tris-phosphate was blocked after inhibition of inositol-trisphosphate receptors but not after inhibition of c-Raf/mitogen-activated proteinmore » kinase kinase (MEK)/mitogen-activated protein kinase (ERK) or p38 mitogen-activated protein kinase pathways. The study shows that D-myo-inositol 1,4,5-tris-phosphate-induced cardiac hypertrophy is mediated by GATA4 but independent from the calcineurin pathway.« less

Tris(thioimidazolyl)borate-zinc-thiolate complexes for the modeling of biological thiolate alkylations.

PubMed

Ibrahim, Mohamed M; Seebacher, Jan; Steinfeld, Gunther; Vahrenkamp, Heinrich

2005-11-14

The S3Zn-SR coordination of thiolate-alkylating enzymes such as the Ada DNA repair protein was reproduced in tris(thioimidazolyl)borate-zinc-thiolate complexes Tti(R)Zn-SR'. Four different Tti(R) ligands and nine different thiolates were employed, yielding a total of 12 new complexes. In addition, one Tti(R)Zn-SH complex and two thiolate-bridged [Tti(R)-SEt-Tti(R)]+ complexes were obtained. A selection of six thiolate complexes was converted with methyl iodide to the corresponding methyl thioethers and Tti(R)Zn-I. According to a kinetic analysis these reactions are second-order processes, which implies that the alkylations are likely to occur at the zinc-bound thiolates. They are much faster than the alkylations of zinc thiolates with N3 or N2S tripod ligands. The most reactive thiolate, Tti(Xyl)Zn-SEt, reacts slowly with trimethyl phosphate in a nonpolar medium at room temperature, yielding methyl-ethyl-thioether and Tti(Xyl)Zn-OPO(OMe)2 which can be converted back to the thiolate complex with NaSEt. This is the closest reproduction of the Ada repair process so far.

Twinned low-temperature structures of tris(ethylenediamine)zinc(II) sulfate and tris(ethylenediamine)copper(II) sulfate.

PubMed

Lutz, Martin

2010-11-01

Tris(ethylenediamine)zinc(II) sulfate, [Zn(C(2)H(8)N(2))(3)]SO(4), (I), undergoes a reversible solid-solid phase transition during cooling, accompanied by a lowering of the symmetry from high-trigonal P31c to low-trigonal P3 and by merohedral twinning. The molecular symmetries of the cation and anion change from 32 (D(3)) to 3 (C(3)). This lower symmetry allows an ordered sulfate anion and generates in the complex cation two independent N atoms with significantly different geometries. The twinning is the same as in the corresponding Ni complex [Jameson et al. (1982). Acta Cryst. B38, 3016-3020]. The low-temperature phase of tris(ethylenediamine)copper(II) sulfate, [Cu(C(2)H(8)N(2))(3)]SO(4), (II), has only triclinic symmetry and the unit-cell volume is doubled with respect to the room-temperature structure in P31c. (II) was refined as a nonmerohedral twin with five twin domains. The asymmetric unit contains two independent formula units, and all cations and anions are located on general positions with 1 (C(1)) symmetry. Both molecules of the Cu complex are in elongated octahedral geometries because of the Jahn-Teller effect. This is in contrast to an earlier publication, which describes the complex as a compressed octahedron [Bertini et al. (1979). J. Chem. Soc. Dalton Trans. pp. 1409-1414].

Effect of gamma-irradiation on thermal decomposition kinetics, X-ray diffraction pattern and spectral properties of tris(1,2-diaminoethane)nickel(II)sulphate

NASA Astrophysics Data System (ADS)

Jayashri, T. A.; Krishnan, G.; Rema Rani, N.

2014-12-01

Tris(1,2-diaminoethane)nickel(II)sulphate was prepared, and characterised by various chemical and spectral techniques. The sample was irradiated with 60Co gamma rays for varying doses. Sulphite ion and ammonia were detected and estimated in the irradiated samples. Non-isothermal decomposition kinetics, X-ray diffraction pattern, Fourier transform infrared spectroscopy, electronic, fast atom bombardment mass spectra, and surface morphology of the complex were studied before and after irradiation. Kinetic parameters were evaluated by integral, differential, and approximation methods. Irradiation enhanced thermal decomposition, lowering thermal and kinetic parameters. The mechanism of decomposition is controlled by R3 function. From X-ray diffraction studies, change in lattice parameters and subsequent changes in unit cell volume and average crystallite size were observed. Both unirradiated and irradiated samples of the complex belong to trigonal crystal system. Decrease in the intensity of the peaks was observed in the infrared spectra of irradiated samples. Electronic spectral studies revealed that the M-L interaction is unaffected by irradiation. Mass spectral studies showed that the fragmentation patterns of the unirradiated and irradiated samples are similar. The additional fragment with m/z 256 found in the irradiated sample is attributed to S8+. Surface morphology of the complex changed upon irradiation.

A Comparative Study of Four Methods for the Detection of Nematode Eggs and Large Protozoan Cysts in Mandrill Faecal Material.

PubMed

Pouillevet, Hanae; Dibakou, Serge-Ely; Ngoubangoye, Barthélémy; Poirotte, Clémence; Charpentier, Marie J E

2017-01-01

Coproscopical methods like sedimentation and flotation techniques are widely used in the field for studying simian gastrointestinal parasites. Four parasites of known zoonotic potential were studied in a free-ranging, non-provisioned population of mandrills (Mandrillus sphinx): 2 nematodes (Necatoramericanus/Oesophagostomum sp. complex and Strongyloides sp.) and 2 protozoan species (Balantidium coli and Entamoeba coli). Different coproscopical techniques are available but they are rarely compared to evaluate their efficiency to retrieve parasites. In this study 4 different field-friendly methods were compared. A sedimentation method and 3 different McMaster methods (using sugar, salt, and zinc sulphate solutions) were performed on 47 faecal samples collected from different individuals of both sexes and all ages. First, we show that McMaster flotation methods are appropriate to detect and thus quantify large protozoan cysts. Second, zinc sulphate McMaster flotation allows the retrieval of a higher number of parasite taxa compared to the other 3 methods. This method further shows the highest probability to detect each of the studied parasite taxa. Altogether our results show that zinc sulphate McMaster flotation appears to be the best technique to use when studying nematodes and large protozoa. © 2017 S. Karger AG, Basel.

Vacuum impregnation: a promising way for mineral fortification in potato porous matrix (potato chips).

PubMed

Joshi, Alka; Kar, A; Rudra, S G; Sagar, V R; Varghese, E; Lad, M; Khan, I; Singh, B

2016-12-01

Potato chips can be considered as an ideal carrier for targeted nutrient/s delivery as mostly consumed by the vulnerable group (children and teen agers). The present study was planned to fortifiy potato chips with calcium (Calcium lactate) and zinc (Zinc sulphate) using vacuum impregnation technique. At about 70-80 mm Hg vacuum pressure, maximum level of impregnation of both the minerals was achieved. Results showed that after optimization, calcium lactate at 4.81%, zinc sulphate at 0.72%, and vacuum of 33.53 mm Hg with restoration period of 19.52 min can fortify potato chips that can fulfil 10 and 21% need of calcium and zinc, respectively of targeted group (age 4-17 years). The present research work has shown that through this technique, fortification can be done in potato chips which are generally considered as a poor source of minerals. Further to make potato chips more fit to health conscious consumers, rather frying microwaving was done to develop mineral fortified low fat potato chips.

Effects of feeding different concentration and forms of zinc on the performance and tissue mineral status of broiler chicks.

PubMed

Ao, T; Pierce, J L; Pescatore, A J; Cantor, A H; Dawson, K A; Ford, M J; Paul, M

2011-08-01

1. Two studies were conducted to investigate the effect of feeding different concentration and forms of zinc (Zn) on the performance and tibia Zn status of broiler chicks. 2. In Experiment 1, chicks fed on the control or the diet supplemented with 12?mg of Zn as sulphate had lower feed intake, weight gain and tibia Zn content than other treatment groups. Chicks given 12 and 24 mg of organic Zn in starter and grower phases, respectively, had the same performance and tibia Zn content as those fed 40 mg of Zn as sulphate and the same performance but higher tibia Zn content than those given 12 mg of Zn as organic over the 42 d. 3. In Experiment 2, chicks given 24 mg organic Zn had greater weight gain than chicks fed on the other treatment diets in the starter period. Chicks fed on the control diet had lower tibia Zn content than chicks fed other treatment diets. Chicks given 80 mg Zn as sulphate had higher tibia Zn content than chicks fed the other treatment diets except those given 40 mg of Zn as sulphate. 4. The results from these trials indicate that feeding lower concentration of Zn as organic form may better promote the growth performance of broiler chicks.

Improvement of ion chromatography with ultraviolet photometric detection and comparison with conductivity detection for the determination of serum cations.

PubMed

Shintani, H

1985-05-31

Studies were made of the analytical conditions required for indirect photometric ion chromatography using ultraviolet photometric detection (UV method) for the determination of serum cations following a previously developed serum pre-treatment. The sensitivities of the conductivity detection (CD) and UV methods and the amounts of serum cations determined by both methods were compared. Attempts to improve the sensitivity of the conventional UV method are reported. It was found that the mobile phase previously reported by Small and Miller showed no quantitative response when more than 4 mM copper(II) sulphate pentahydrate was used. As a result, there was no significant difference in the amounts of serum cations shown by the CD and UV methods. However, by adding 0.5-5 mM cobalt(II) sulphate heptahydrate, nickel(II) sulphate hexahydrate, zinc(II) sulphate heptahydrate or cobalt(II) diammonium sulphate hexahydrate to 0.5-1.5 mM copper(II) sulphate pentahydrate, higher sensitivity and a quantitative response were attained.

[MORPHOFUNCTIONAL ADJUSTMENT VASCULAR AND CELLULAR COMPONENTS OF THE CEREBELLAR CORTEX IN EXPOSURE TO BODY SULFATES OF COPPER, ZINC AND IRON].

PubMed

Grintsova, N; Vasko, L; Kiptenko, L; Gortinsky, A; Murenets, N

2015-09-01

In order to analyze the morphological and morphometric reconstructions of the vascular bed, and Purkinje cells of the cerebellar cortex of rats in long-term action (for 90 days) on the body of sulphates of copper, zinc and iron, an experiment was conducted on 48 adult white male rats weighing 200-250 g in age 5-7 months. We used anatomical, morphometric, statistical and common methods of microanatomical research. It was found that the combined effect on the body of sulphates of copper and zinc, and iron in the cerebellum has enough expressive toxicity, which affects the condition of the vascular bed, and Purkinje cells. The degree of morphological transformations is in direct proportion to the duration of the experiment. In the pathogenesis of violations leading role played by hypoxia, develop signs of swelling of the cerebellar cortex with signs hemorrhagic infiltration, the severity of which is maximum on the 60th day of the experiment.

ZnS/Zn(O,OH)S-based buffer layer deposition for solar cells

DOEpatents

Bhattacharya, Raghu N [Littleton, CO

2009-11-03

The invention provides CBD ZnS/Zn(O,OH)S and spray deposited ZnS/Zn(O,OH)S buffer layers prepared from a solution of zinc salt, thiourea and ammonium hydroxide dissolved in a non-aqueous/aqueous solvent mixture or in 100% non-aqueous solvent. Non-aqueous solvents useful in the invention include methanol, isopropanol and triethyl-amine. One-step deposition procedures are described for CIS, CIGS and other solar cell devices.

Tailoring of optical band gap by varying Zn content in Cd{sub 1-x}Zn{sub x}S thin films prepared by spray pyrolysis method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Vipin, E-mail: vipinkumar28@yahoo.co.in; Sharma, D. K.; Agrawal, Sonalika

Cd{sub 1-X}Zn{sub X}S thin films (X = 0.2, 0.4, 0.6, 0.8) have been grown on glass substrate by spray pyrolysis technique using equimolar concentration aqueous solution of cadmium chloride, zinc acetate and thiourea. Prepared thin films have been characterized by UV-VIS spectrophotometer. The optical band gap of the films has been studied by transmission spectra in wavelength range 325-600nm. It has been observed that optical band gap increases with increasing zinc concentration. The optical band gap of these thin films varies from 2.59 to 3.20eV with increasing Zn content.

An advanced study on the hydrometallurgical processing of waste computer printed circuit boards to extract their valuable content of metals.

PubMed

Birloaga, Ionela; Coman, Vasile; Kopacek, Bernd; Vegliò, Francesco

2014-12-01

This study refers to two chemical leaching systems for the base and precious metals extraction from waste printed circuit boards (WPCBs); sulfuric acid with hydrogen peroxide have been used for the first group of metals, meantime thiourea with the ferric ion in sulfuric acid medium were employed for the second one. The cementation process with zinc, copper and iron metal powders was attempted for solutions purification. The effects of hydrogen peroxide volume in rapport with sulfuric acid concentration and temperature were evaluated for oxidative leaching process. 2M H2SO4 (98% w/v), 5% H2O2, 25 °C, 1/10 S/L ratio and 200 rpm were founded as optimal conditions for Cu extraction. Thiourea acid leaching process, performed on the solid filtrate obtained after three oxidative leaching steps, was carried out with 20 g/L of CS(NH2)2, 6g/L of Fe(3+), 0.5M H2SO4, The cross-leaching method was applied by reusing of thiourea liquid suspension and immersing 5 g/L of this reagent for each other experiment material of leaching. This procedure has lead to the doubling and, respectively, tripling, of gold and silver concentrations into solution. These results reveal a very efficient, promising and environmental friendly method for WPCBs processing. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of mechanical properties of some glycine complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagaraju, D.; Raja Shekar, P. V., E-mail: pvrsleo@gmail.com; Chandra, Ch. Sateesh

2014-04-24

The variation of Vickers hardness with load for (101) glycine zinc chloride (GZC), (001) glycine lithium sulphate (GLS), (001) triglycine sulphate (TGS) and (010) glycine phosphite (GPI) crystals was studied. From the cracks initiated along the corners of the indentation impression, crack lengths were measured and the fracture toughness value and brittle index number were determined. The hardness related parameters viz. yield strength and Young’s modulus were also estimated. The anisotropic nature of the crystals was studied using Knoop indentation technique.

Cadmium zinc sulfide by solution growth

DOEpatents

Chen, Wen S.

1992-05-12

A process for depositing thin layers of a II-VI compound cadmium zinc sulfide (CdZnS) by an aqueous solution growth technique with quality suitable for high efficiency photovoltaic or other devices which can benefit from the band edge shift resulting from the inclusion of Zn in the sulfide. A first solution comprising CdCl.sub.2 2.5H.sub.2 O, NH.sub.4 Cl, NH.sub.4 OH and ZnCl.sub.2, and a second solution comprising thiourea ((NH.sub.2).sub.2 CS) are combined and placed in a deposition cell, along with a substrate to form a thin i.e. 10 nm film of CdZnS on the substrate. This process can be sequentially repeated with to achieve deposition of independent multiple layers having different Zn concentrations.

The effect of feed supplementation with zinc chelate and zinc sulphate on selected humoral and cell-mediated immune parameters and cytokine concentration in broiler chickens.

PubMed

Jarosz, Łukasz; Marek, Agnieszka; Grądzki, Zbigniew; Kwiecień, Małgorzata; Kalinowski, Marcin

2017-06-01

The ability of poultry to withstand infectious disease caused by bacteria, viruses or protozoa depends upon the integrity of the immune system. Zinc is important for proper functioning of heterophils, mononuclear phagocytes and T lymphocytes. Numerous data indicate that the demand for zinc in poultry is not met in Poland due to its low content in feeds of vegetable origin. The aim of the study was to determine the effect of supplementation of inorganic (ZnSO 4 and ZnSO 4 + phytase enzyme), and organic forms of zinc (Zn with glycine and Zn with glycine and phytase enzyme) on selected parameters of the cellular and humoral immune response in broiler chickens by evaluating the percentage of CD3 + CD4 + , CD3 + CD8 + , CD25 + , MHC Class II, and BU-1 + lymphocytes, the phagocytic activity of monocytes and heterophils, and the concentration of IL-2, IL-10 and TNF-α in the peripheral blood. Flow cytometry was used to determine selected cell-mediated immune response parameters. Phagocytic activity in whole blood was performed using the commercial Phagotest kit (ORPEGEN-Pharma, Immuniq, Poland). The results showed that supplementation with zinc chelates causes activation of the cellular and humoral immune response in poultry, helping to maintain the balance between the Th1 and Th2 response and enhancing resistance to infections. In contrast with chelates, the use of zinc in the form of sulphates has no immunomodulatory effect and may contribute to the development of local inflammatory processes in the digestive tract, increasing susceptibility to infection. Copyright © 2016. Published by Elsevier Ltd.

A Bis-Triazacyclononane Tris-Pyridyl N9 -Azacryptand "Beer Can" Receptor for Complexation of Alkali Metal and Lead(II) Cations.

PubMed

Brown, Asha; Bunchuay, Thanthapatra; Crane, Christopher G; White, Nicholas G; Thompson, Amber L; Beer, Paul D

2018-04-18

A new bis-triazacyclononane tris-pyridyl N 9 -azacryptand ligand is prepared via a convenient one-pot [2+3] condensation reaction between triazacyclononane and 2,6-bis(bromomethyl) pyridine in the presence of M 2 CO 3 (M=Li, Na, K). The proton, lithium, sodium, potassium and lead(II) complexes of the ligand are characterised in the solid state. Preliminary solution-phase competition experiments indicate that the cryptand ligand preferentially binds lead(II) in the presence of sodium, calcium, potassium and zinc cations in methanol solution. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Apoptosis induced by microtubule disrupting drugs in cultured human lymphoma cells. Inhibitory effects of phorbol ester and zinc sulphate.

PubMed

Takano, Y; Okudaira, M; Harmon, B V

1993-03-01

The effects of the microtubule disrupting drugs (MDD) vinblastine, vincristine and colchicine on a human lymphoma cell line, BM 13674, were investigated. Twelve hours after administration of vinblastine (10(-3) mg/ml), vincristine (10(-2) mg/ml) or colchicine (10(-2) mg/ml), cell death with the characteristic morphology of apoptosis was observed in 71.6%, 82.2% and 76.9% of the cells respectively. The mode of death was confirmed as apoptotic by the occurrence of internucleosomal DNA cleavage, which was demonstrated by agarose gel electrophoresis. For the purpose of casting light on the mechanism involved, inhibition tests were performed on apoptosis induced by one of these drugs, vinblastine, using a phorbol ester (PDBu), zinc sulphate and cycloheximide. PDBu, an activator of protein kinase C, and zinc sulphate, a putative inhibitor of the endonuclease were thought to be responsible for internucleosomal DNA cleavage; both markedly reduced the induction of apoptosis. The protein synthesis inhibitor cycloheximide, on the other hand, had no inhibitory effect. Moreover, cycloheximide treatment per se enhanced apoptosis. This suggests that new protein synthesis is not required for the execution of vinblastine-induced apoptosis. Such a finding is in accord with recent reports suggesting that the "death program" within many cell types may be primed but unable to proceed due to concomitant production of specific "apoptotic inhibitors". It is suggested that phorbol esters prevent vinblastine-induced apoptosis in the BM 13674 cells by activating one or more of these specific "apoptotic inhibitors", possibly by means of PKC-mediated phosphorylation.

8-aminoquinoline functionalized silica nanoparticles: a fluorescent nanosensor for detection of divalent zinc in aqueous and in yeast cell suspension.

PubMed

Rastogi, Shiva K; Pal, Parul; Aston, D Eric; Bitterwolf, Thomas E; Branen, A Larry

2011-05-01

Zinc is one of the most important transition metal of physiological importance, existing primarily as a divalent cation. A number of sensors have been developed for Zn(II) detection. Here, we present a novel fluorescent nanosensor for Zn(II) detection using a derivative of 8-aminoquinoline (N-(quinolin-8-yl)-2-(3 (triethoxysilyl)propylamino)acetamide (QTEPA) grafted on silica nanoparticles (SiNPs). These functionalized SiNPs were used to demonstrate specific detection of Zn(II) in tris-HCl buffer (pH 7.22), in yeast cell (Saccharomyces cerevisiae) suspension, and in tap water. The silane QTEPA, SiNPs and final product were characterized using solution and solid state nuclear magnetic resonance, Fourier transform infrared, ultraviolet-visible absorption spectroscopy, transmission electron microscopy, elemental analysis, thermogravimetric techniques, and fluorescence spectroscopy. The nanosensor shows almost 2.8-fold fluorescence emission enhancement and about 55 nm red-shift upon excitation with 330 ± 5 nm wavelength in presence of 1 μM Zn(II) ions in tris-HCl (pH 7.22). The presence of other metal ions has no observable effect on the sensitivity and selectivity of nanosensor. This sensor selectively detects Zn(II) ions with submicromolar detection to a limit of 0.1 μM. The sensor shows good applicability in the determination of Zn(II) in tris-HCl buffer and yeast cell environment. Further, it shows enhancement in fluorescence intensity in tap water samples.

Organometallic complexes of bulky, optically active, C 3-symmetric tris(4 S-isopropyl-5,5-dimethyl-2-oxazolinyl)phenylborate (To P*)

DOE PAGES

Xu, Songchen; Magoon, Yitzhak; Reinig, Regina R.; ...

2015-07-16

A bulky, optically active monoanionic scorpionate ligand, tris(4S-isopropyl-5,5-dimethyl-2-oxazolinyl)phenylborate (To P*), is synthesized from the naturally occurring amino acid l-valine as its lithium salt, Li[To P*] (1). That compound is readily converted to the thallium complex Tl[To P*] (2) and to the acid derivative H[To P*] (3). Group 7 tricarbonyl complexes To P*M(CO) 3 (M = Mn (4), Re (5)) are synthesized by the reaction of MBr(CO) 5 and Li[To P*] and are crystallographically characterized. The ν CO bands in their infrared spectra indicate that π back-donation in the rhenium compounds is greater with To P* than with non-methylated tris(4S-isopropyl-2-oxazolinyl)phenylborate (Tomore » P). The reaction of H[To P*] and ZnEt 2 gives To P*ZnEt (6), while To P*ZnCl (7) is synthesized from Li[To P*] and ZnCl 2. The reaction of To P*ZnCl and KOtBu followed by addition of PhSiH 3 provides the zinc hydride complex To P*ZnH (8). In this study, compound 8 is the first example of a crystallographically characterized optically active zinc hydride. We tested its catalytic reactivity in the cross-dehydrocoupling of silanes and alcohols, which provided Si-chiral silanes with moderate enantioselectivity.« less

Organometallic complexes of bulky, optically active, C 3-symmetric tris(4 S-isopropyl-5,5-dimethyl-2-oxazolinyl)phenylborate (To P*)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Songchen; Magoon, Yitzhak; Reinig, Regina R.

A bulky, optically active monoanionic scorpionate ligand, tris(4S-isopropyl-5,5-dimethyl-2-oxazolinyl)phenylborate (To P*), is synthesized from the naturally occurring amino acid l-valine as its lithium salt, Li[To P*] (1). That compound is readily converted to the thallium complex Tl[To P*] (2) and to the acid derivative H[To P*] (3). Group 7 tricarbonyl complexes To P*M(CO) 3 (M = Mn (4), Re (5)) are synthesized by the reaction of MBr(CO) 5 and Li[To P*] and are crystallographically characterized. The ν CO bands in their infrared spectra indicate that π back-donation in the rhenium compounds is greater with To P* than with non-methylated tris(4S-isopropyl-2-oxazolinyl)phenylborate (Tomore » P). The reaction of H[To P*] and ZnEt 2 gives To P*ZnEt (6), while To P*ZnCl (7) is synthesized from Li[To P*] and ZnCl 2. The reaction of To P*ZnCl and KOtBu followed by addition of PhSiH 3 provides the zinc hydride complex To P*ZnH (8). In this study, compound 8 is the first example of a crystallographically characterized optically active zinc hydride. We tested its catalytic reactivity in the cross-dehydrocoupling of silanes and alcohols, which provided Si-chiral silanes with moderate enantioselectivity.« less

Synthesis, structure and reactivity of [Tm(Bu(t))]ZnH, a monomeric terminal zinc hydride compound in a sulfur-rich coordination environment: access to a heterobimetallic compound.

PubMed

Kreider-Mueller, Ava; Quinlivan, Patrick J; Rauch, Michael; Owen, Jonathan S; Parkin, Gerard

2016-02-07

The first terminal zinc hydride complex that features a sulfur-rich coordination environment, namely the tris(2-mercapto-1-tert-butylimidazolyl)hydroborato compound, [Tm(Bu(t))]ZnH, has been synthesized via the reaction of [Tm(Bu(t))]ZnOPh with PhSiH3. The Zn-H bond of [Tm(Bu(t))]ZnH is subject to insertion of CO2 and facile protolytic cleavage, of which the latter provides access to heterobimetallic [Tm(Bu(t))]ZnMo(CO)3Cp.

Selective inclusion of PO4(3-) within persistent dimeric capsules of a tris(thiourea) receptor and evidence of cation/solvent sealed unimolecular capsules.

PubMed

Dey, Sandeep Kumar; Das, Gopal

2012-08-07

A tren-based tris(thiourea) receptor, L with electron-withdrawing p-nitrophenyl terminals has been established as a competent hydrogen-bonding scaffold that can selectively encapsulate PO(4)(3-) within persistent and rigid dimeric capsules, assembled by aromatic π-stacking interactions between the receptor side-arms. A quaternary ammonium salt of PO(4)(3-) capsules (complexes 1 and 1b, 2:1 host-guest) can reproducibly be obtained in quantitative yields by a solution-state deprotonation of [HL](+) moieties and a bound HPO(4)(2-) anion of complex 1a (HPO(4)(2-) complex of protonated L, 2:1 host-guest), induced by the presence of a large excess of anions such as HCO(3)(-), CH(3)CO(2)(-), and F(-). Qualitative as well as quantitative (1)H and (31)P NMR experiments (DMSO-d(6)) have been carried out in detail to demonstrate the selective and preferential inclusion of PO(4)(3-) by L in solution-states. Competitive crystallization experiments performed in the presence of an excess of anions such as HCO(3)(-), HSO(4)(-), CH(3)CO(2)(-), NO(3)(-) and halides (F(-) and Cl(-)) further establish the phenomenon of selective PO(4)(3-) encapsulation as confirmed by (1)H NMR, (31)P NMR, FT-IR and powder X-ray diffraction patterns of the isolated crystals. X-ray structural analyses and (31)P NMR studies of the isolated crystals of phosphate complexes (1, 1a and 1b) provide evidence of the binding discrepancy of inorganic phosphates with protonated and neutral form of L. Furthermore, extensive studies have been carried out with other anions of different sizes and dimensions in solid- and solution-states (complexes 2a, 3, 4 and 5). Crystal structure elucidation revealed the formation of a solvent (DMSO) sealed unimolecular capsule in the F(-) encapsulated complex, 2a (1:1 host-guest), a CO(3)(2-) encapsulated centrosymmetric molecular capsule in 3 (2:1 host-guest) and a cation (tetrabutylammonium) sealed SO(4)(2-) encapsulated unimolecular capsule in 4 (1:1 host-guest). 2D-NOESY NMR experiments carried out on these capsule complexes further confirm the relevant binding stoichiometry of complexes (2a-4) except for the PO(4)(3-)-encapsulated complex (1b) which showed a 1:1 host-guest stoichiometry in solution.

Degradation of Organic Matter from Stabilized Leachate by Using Zinc Sulphate as Coagulant Agent

NASA Astrophysics Data System (ADS)

Kamaruddin, M. A.; Yusoff, MS; Adam, N. H.; Maz, M. R. R.; Abdullah, M. M. A. B.; Alrozi, R.; Zawawi, M. H.

2018-06-01

Stabilized landfill leachate often contains higher organic fractions than the young one. The organics require several sequential treatments to render the leachate parameters concentrations to permissible discharge limits before being discharged to receiving water. This study focused on the application of Zinc Sulphate (ZnSO4) as coagulant agent followed with microfiltration of 0.45 µm pore size under different condition of landfill leachates. The results indicated that the sludge volume index (SVI), soluble COD and turbidity concentrations were inter-related to each other when compared under different ZnSO4 dosages. However, that was not the case when correlation between stabilized and young leachate were compared side by side. To conform the finding, one-way analysis of variance (ANOVA) was conducted and the results were further explained by the adequacy and significant of confidence interval. Finally, it was proven that, soluble and particulate COD had significant CI of 95% applicable for stabilized leachate alone.

Unraveling aminophosphine redox mechanisms for glovebox-free InP quantum dot syntheses.

PubMed

Laufersky, Geoffry; Bradley, Siobhan; Frécaut, Elian; Lein, Matthias; Nann, Thomas

2018-05-10

The synthesis of colloidal indium phosphide quantum dots (InP QDs) has always been plagued by difficulties arising from limited P3- sources. Being effectively restricted to the highly pyrophoric tris(trimethylsilyl) phosphine (TMS3P) creates complications for the average chemist and presents a significant risk for industrially scaled reactions. The adaptation of tris(dialkylamino) phosphines for these syntheses has garnered attention, as these new phosphines are much safer and can generate nanoparticles with competitive photoluminescence properties to those from (TMS)3P routes. Until now, the reaction mechanics of this precursor were elusive due to many experimental optimizations, such as the inclusion of a high concentration of zinc salts, being atypical of previous InP syntheses. Herein, we utilize density functional theory calculations to outline a logical reaction mechanism. The aminophosphine precursor is found to require activation by a zinc halide before undergoing a disproportionation reaction to self-reduce this P(iii) material to a P(-iii) source. We use this understanding to adapt this precursor for a two-pot nanoparticle synthesis in a noncoordinating solvent outside of glovebox conditions. This allowed us to generate spherical InP/ZnS nanoparticles possessing fluorescence quantum yields >55% and lifetimes as fast as 48 ns, with tunable emission according to varying zinc halide acidity. The development of high quality and efficient InP QDs with this safer aminophosphine in simple Schlenk environments will enable a broader range of researchers to synthesize these nontoxic materials for a variety of high-value applications.

Nonlinear optical and microscopic analysis of Cu2+ doped zinc thiourea chloride (ZTC) monocrystal

NASA Astrophysics Data System (ADS)

Ramteke, S. P.; Anis, Mohd; Pandian, M. S.; Kalainathan, S.; Baig, M. I.; Ramasamy, P.; Muley, G. G.

2018-02-01

Organometallic crystals offer considerable nonlinear response therefore, present article focuses on bulk growth and investigation of Cu2+ ion doped zinc thiourea chloride (ZTC) crystal to explore its technological impetus for laser assisted nonlinear optical (NLO) device applications. The Cu2+ ion doped ZTC bulk single crystal of dimension 03 × 2.4 × 0.4 cm3 has been grown from pH controlled aqueous solution by employing slow solvent evaporation technique. The structural analysis has been performed by means of single crystal X-ray diffraction technique. The doping of Cu2+ ion in ZTC crystal matrix has been confirmed by means of energy dispersive spectroscopic (EDS) technique. The origin of nonlinear optical properties in Cu2+ ion doped ZTC crystal has been studied by employing the Kurtz-Perry test and Z-scan analysis. The remarkable enhancement in second harmonic generation (SHG) efficiency of Cu2+ ion doped ZTC crystal with reference to ZTC crystal has been determined. The He-Ne laser assisted Z-scan analysis has been performed to determine the third order nonlinear optical (TONLO) nature of grown crystal. The TONLO parameters such as susceptibility, absorption coefficient, refractive index and figure of merit of Cu-ZTC crystal have been evaluated using the Z-scan transmittance data. The laser damage threshold of grown crystal to high intensity of Nd:YAG laser is found to be 706.2 MW/cm2. The hardness number, work hardening index, yield strength and elastic stiffness coefficient of grown crystal has been investigated under microhardness study. The etching study has been carried out to determine the growth likelihood, nature of etch pits and surface quality of grown crystal.

Multi-modular, tris(triphenylamine) zinc porphyrin-zinc phthalocyanine-fullerene conjugate as a broadband capturing, charge stabilizing, photosynthetic 'antenna-reaction center' mimic.

PubMed

Kc, Chandra B; Lim, Gary N; D'Souza, Francis

2015-04-21

A broadband capturing, charge stabilizing, photosynthetic antenna-reaction center model compound has been newly synthesized and characterized. The model compound is comprised of a zinc porphyrin covalently linked to three units of triphenylamine entities and a zinc phthalocyanine entity. The absorption and fluorescence spectra of zinc porphyrin complemented that of zinc phthalocyanine offering broadband coverage. Stepwise energy transfer from singlet excited triphenylamine to zinc porphyrin, and singlet excited zinc porphyrin to zinc phthalocyanine (kENT ∼ 10(11) s(-1)) was established from spectroscopic and time-resolved transient absorption techniques. Next, an electron acceptor, fullerene was introduced via metal-ligand axial coordination to both zinc porphyrin and zinc phthalocyanine centers, and they were characterized by spectroscopic and electrochemical techniques. An association constant of 4.9 × 10(4) M(-1) for phenylimidazole functionalized fullerene binding to zinc porphyrin, and 5.1 × 10(4) M(-1) for it binding to zinc phthalocyanine was obtained. An energy level diagram for the occurrence of different photochemical events within the multi-modular donor-acceptor conjugate was established from spectral and electrochemical data. Unlike the previous zinc porphyrin-zinc phthalocyanine-fullerene conjugates, the newly assembled donor-acceptor conjugate has been shown to undergo the much anticipated initial charge separation from singlet excited zinc porphyrin to the coordinated fullerene followed by a hole shift process to zinc phthalocyanine resulting in a long-lived charge separated state as revealed by femto- and nanosecond transient absorption spectroscopic techniques. The lifetime of the final charge separated state was about 100 ns.

Dynamic Multi-Component Hemiaminal Assembly

PubMed Central

You, Lei; Long, S. Reid; Lynch, Vincent M.

2012-01-01

A simple approach to generating in situ metal templated tris-(2-picolyl)amine-like multi-component assemblies with potential applications in molecular recognition and sensing is reported. The assembly is based on the reversible covalent association between di-(2-picolyl)amine and aldehydes. Zinc ion is the best for inducing assembly among the metal salts investigated, while 2-picolinaldehyde is the best among the heterocyclic aldehydes studied. Although an equilibrium constant of 6.6 * 103 M-1 was measured for the assembly formed by 2-picolinaldehdye, di-(2-picolyl)amine, and zinc triflate, the equilibrium constants for other systems are in the 102 M-1 range. X-ray structural analysis revealed that zinc adopts a trigonal bipyramidal geometry within the assembled ligand. The diversity and equilibrium of the assemblies are readily altered by simply changing concentrations, varying components, or adding counter anions. PMID:21919095

Copper-Zinc-Tin-Sulfur Thin Film Using Spin-Coating Technology

PubMed Central

Yeh, Min-Yen; Lei, Po-Hsun; Lin, Shao-Hsein; Yang, Chyi-Da

2016-01-01

Cu2ZnSnS4 (CZTS) thin films were deposited on glass substrates by using spin-coating and an annealing process, which can improve the crystallinity and morphology of the thin films. The grain size, optical gap, and atomic contents of copper (Cu), zinc (Zn), tin (Sn), and sulfur (S) in a CZTS thin film absorber relate to the concentrations of aqueous precursor solutions containing copper chloride (CuCl2), zinc chloride (ZnCl2), tin chloride (SnCl2), and thiourea (SC(NH2)2), whereas the electrical properties of CZTS thin films depend on the annealing temperature and the atomic content ratios of Cu/(Zn + Sn) and Zn/Sn. All of the CZTS films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXS), Raman spectroscopy, and Hall measurements. Furthermore, CZTS thin film was deposited on an n-type silicon substrate by using spin-coating to form an Mo/p-CZTS/n-Si/Al heterostructured solar cell. The p-CZTS/n-Si heterostructured solar cell showed a conversion efficiency of 1.13% with Voc = 520 mV, Jsc = 3.28 mA/cm2, and fill-factor (FF) = 66%. PMID:28773647

Addition of zinc methacrylate in dental polymers: MMP-2 inhibition and ultimate tensile strength evaluation.

PubMed

Henn, Sandrina; de Carvalho, Rodrigo Varella; Ogliari, Fabrício Aulo; de Souza, Ana Paula; Line, Sergio Roberto Peres; da Silva, Adriana Fernandes; Demarco, Flávio Fernando; Etges, Adriana; Piva, Evandro

2012-04-01

This study evaluated the effect of zinc methacrylate (ZM) on the inhibition of matrix metalloproteinase 2 (MMP-2) and the ultimate tensile strength (UTS) of an experimental polymer. Enzymes secreted from mouse gingival tissues were analyzed by gelatin zymography in buffers containing 5 mM CaCl(2) (Tris-CaCl(2)) in 50 mM Tris-HCl buffer with various concentrations of ZM (0.5, 1, 2, 4, 8, and 16 mM). The matrix metalloproteinases present in the conditioned media were characterized by immunoprecipitation. The polymer UTS evaluation was performed in eight groups with various concentrations of ZM (0, 0.5, 1, 2.5, 5, 10, 20, and 30 wt.%), in a mechanical testing machine. MMP-2 (62 kDa) was detected in the zymographic assays and inhibited by ZM in all tested concentrations. UTS data were submitted to one-way ANOVA and Tukey's test (α = 0.05), and no significant differences were observed among groups, except in the polymer containing 30% ZM, presenting a significantly lower value when compared with the control group (p < 0.05). The results suggest that ZM inhibits MMP-2 expression in all concentrations tested, while small concentrations did not affect the ultimate tensile strength of the polymer. Zinc methacrylate is a metalloproteinase inhibitor that can be copolymerized with other methacrylate monomers. Yet, the addition of ZM did not affect the resin bond strength. Thus, in vivo tests should be performed to evaluate the performance of this material.

Effect of thiourea on electrochemical nucleation and electrochemical impedance spectroscopy of electrodeposited tin on a copper substrate in a sulfate bath.

PubMed

Lee, Mi-Ri; Na, Seong-Hun; Park, Hwa-Sun; Suh, Su-Jeong

2014-12-01

The effect of thiourea on the electrochemical nucleation of tin on a copper substrate from a sulfate bath was studied using voltammetry, chronoamperometry, electrochemical impedance spectroscopy, and scanning electron microscopy. Without thiourea, electrodeposition of tin showed very poor surface coverage. However, re-nucleation and growth of tin occurred after the addition of thiourea. In particular, very rapid re-nucleation and growth behavior of tin were observed when up to 6 g/L of thiourea was added. Furthermore, impedance analysis allowed the estimation of the change in the growth behavior of tin when up to 6 g/L of thiourea was added.

Effects of Different Zinc Species on Cellar Zinc Distribution, Cell Cycle, Apoptosis and Viability in MDAMB231 Cells.

PubMed

Wang, Yan-hong; Zhao, Wen-jie; Zheng, Wei-juan; Mao, Li; Lian, Hong-zhen; Hu, Xin; Hua, Zi-chun

2016-03-01

Intracellular metal elements exist in mammalian cells with the concentration range from picomoles per litre to micromoles per litre and play a considerable role in various biological procedures. Element provided by different species can influence the availability and distribution of the element in a cell and could lead to different biological effects on the cell's growth and function. Zinc as an abundant and widely distributed essential trace element, is involved in numerous and relevant physiological functions. Zinc homeostasis in cells, which is regulated by metallothioneins, zinc transporter/SLC30A, Zrt-/Irt-like proteins/SLC39A and metal-response element-binding transcription factor-1 (MTF-1), is crucial for normal cellular functioning. In this study, we investigated the influences of different zinc species, zinc sulphate, zinc gluconate and bacitracin zinc, which represented inorganic, organic and biological zinc species, respectively, on cell cycle, viability and apoptosis in MDAMB231 cells. It was found that the responses of cell cycle, apoptosis and death to different zinc species in MDAMB231 cells are different. Western blot analysis of the expression of several key proteins in regulating zinc-related transcription, cell cycle, apoptosis, including MTF-1, cyclin B1, cyclin D1, caspase-8 and caspase-9 in treated cells further confirmed the observed results on cell level.

Isolation and Analysis of Keratins and Keratin-Associated Proteins from Hair and Wool.

PubMed

Deb-Choudhury, Santanu; Plowman, Jeffrey E; Harland, Duane P

2016-01-01

The presence of highly cross-linked protein networks in hair and wool makes them very difficult substrates for protein extraction, a prerequisite for further protein analysis and characterization. It is therefore imperative that these cross-links formed by disulfide bridges are first disrupted for the efficient extraction of proteins. Chaotropes such as urea are commonly used as efficient extractants. However, a combination of urea and thiourea not only improves recovery of proteins but also results in improved resolution of the keratins in 2DE gels. Reductants also play an important role in protein dissolution. Dithiothreitol effectively removes keratinous material from the cortex, whereas phosphines, like Tris(2-carboxyethyl)phosphine, remove material from the exocuticle. The relative extractability of the keratins and keratin-associated proteins is also dependent on the concentration of chaotropes, reductants, and pH, thus providing a means to preferentially extract these proteins. Ionic liquids such as 1-butyl-3-methylimidazolium chloride (BMIM(+)[Cl](-)) are known to solubilize wool by disrupting noncovalent interactions, specifically intermolecular hydrogen bonds. BMIM(+)[Cl](-) proved to be an effective extractant of wool proteins and complementary in nature to chaotropes such as urea and thiourea for identifying unique peptides of wool proteins using mass spectrometry (MS). Successful identification of proteins resolved by one- or two-dimensional electrophoresis and MS is highly dependent on the optimal recovery of its protease-digested peptides with an efficient removal of interfering substances. The detergent sodium deoxycholate used in conjunction with Empore™ disks improved identification of proteins by mass spectrometry leading to higher percentage sequence coverage, identification of unique peptides and higher score. Copyright © 2016 Elsevier Inc. All rights reserved.

Maskless Nanoscale Writing of Nanoparticle-Polymer Composites and Nanoparticle Assemblies using Thermal Nanoprobes

DTIC Science & Technology

2009-09-14

the otherwise difficult to deposit Alq3 using a p(VDF-TrFE) carrier. The Alq3 retains its ability to fluoresce after deposition. (h) SEM of the...aluminum tris(8-hydroxyquinoline) ( Alq3 ) ∼0.9 P(VDF-TrFE) 1 zinc diethyldithiocarbamate ∼1.2 P(VDF-TrFE) 1 CdSe-ZnS core-shell 2-4 PE 1 dodecanethiol

[Effects of thiourea on pH and availability of metal ions in acid red soil].

PubMed

Yang, Bo; Wang, Wen; Zeng, Qing-Ru; Zhou, Xi-Hong

2014-03-01

Through the simulation research, the effects of application of thiourea and urea on pH and availability of metal ions in acid red soil were studied, and the results showed that after applying urea, the soil pH increased in the first experimental stage and then reduced gradually to a low level, however, decreased trends of soil pH values were inhibited by the application of thiourea, especially when the concentration of thiourea reached to 5.0 mmol x kg(-1) dry soil, the soil pH was stable at high level, which exceeded to 6.0. It proved that the application of thiourea could inhibit the soil acidification due to urea application. After applying urea with different concentrations of thiourea, the available contents of Zn and Al decreased with the increasing concentration of thiourea, nevertheless, when the concentration of thiourea reached to 5.0 mmol x kg(-1), the available content of Mn was stable at high level which was over 110 mg x kg(-1). In addition, the results showed a highly significant negative correlation between the soil pH and the available content of Cu, Zn and Al, but for Mn, no discipline was found between the soil pH and the availability after applying thiourea. Moreover, the soil pH became higher after applying urea with thiourea compared to add urea only, which led to the decreasing of available content of Al, and it was benefited for the control of the phytotoxic effect of Al. The available content of Mn in the soil not only depended on soil pH but also the content of thiourea due to its redox and complexing reaction with Mn.

The role of particle size of particulate nano-zinc oxide wood preservatives on termite mortality and leach resistance

NASA Astrophysics Data System (ADS)

Clausen, Carol A.; Kartal, S. Nami; Arango, Rachel A.; Green, Frederick

2011-06-01

Historically most residential wood preservatives were aqueous soluble metal formulations, but recently metals ground to submicron size and dispersed in water to give particulate formulations have gained importance. In this study, the specific role nano-zinc oxide (ZnO) particle size and leach resistance plays in termite mortality resulting from exposure to particulate ZnO-treated wood was investigated. Southern yellow pine (SYP) sapwood impregnated with three concentrations of two particle sizes (30 and 70 nm) of ZnO were compared to wood treated with soluble zinc sulphate (ZnSO4) preservative for leach resistance and termite resistance. Less than four percent leached from the particulate nano-ZnO-treated specimens, while 13 to 25% of the zinc sulphate leached from the soluble treated wood. Nano-ZnO was essentially non-leachable from wood treated with 5% formulation for the 30-nm particle size. In a no-choice laboratory test, eastern subterranean termites ( Reticulitermes flavipes) consumed less than 10% of the leached nano-ZnO-treated wood with 93 to 100% mortality in all treatment concentrations. In contrast, termites consumed 10 to 12% of the leached ZnSO4-treated wood, but with lower mortality: 29% in the 1% treatment group and less than 10% (5 and 8%, respectively) in the group of wood blocks treated with 2.5 and 5.0% ZnSO4. We conclude that termites were repelled from consuming wood treated with nano-ZnO, but when consumed it was more toxic to eastern subterranean termites than wood treated with the soluble metal oxide formulation. There were no differences in leaching or termite mortality between the two particle sizes of nano-ZnO.

Effect of ultrasound on the dissolution of copper from copper converter slag by acid leaching.

PubMed

Beşe, Ayşe Vildan

2007-09-01

This work presents the optimum conditions of dissolution of copper in copper converter slag in sulphuric acid ferric sulphate mixtures in the presence and absence of ultrasound. The Taguchi method was used to determine the optimum conditions. The parameters investigated were the reaction temperature, acid concentration, ferric sulphate concentration and reaction time. The optimum conditions for the maximum dissolution of copper were determined as follows: reaction temperature, 65 degrees C; acid concentration, 0.2M; ferric sulphate concentration, 0.15M; reaction time 180 min. Under these conditions, extraction efficiency of copper, zinc, cobalt, and iron from slag were 89.28%, 51.32%, 69.87%, and 13.73%, respectively, in the presence of ultrasound, while they are 80.41%, 48.28%, 64.52%, and 12.16%, respectively, in the absence of ultrasound. As seen from the above results, it is clear that ultrasound enhances on the dissolution of Cu, Zn, Co and Fe in the slag.

Chemical Synthesis of ZnS:Cu Nanosheets

NASA Astrophysics Data System (ADS)

Bodo, Bhaskarjyoti; Kalita, P. K.

2010-10-01

ZnS thin films are synthesized through chemical bath deposition (CBD) technique from aqueous solution of ZnSO4 and thiourea mixing in equal volume and equimolar ratio. A 1% CuSO4 solution is mixed with the ZnSO4 solution for doping before the final chemical reaction. SEM image shows the formation of mainly nanosheets, teeth and comb like structures. Absorption studies show red shift of enhanced band gap on Cu doping. Photoluminescence of ZnS:Cu reveals the enhancement of blue luminescence at 468 nm and low intensity green emission at 493 nm which is attributed to more Cu2+ lying in the interstices. XRD shows that the prepared ZnS nanophosphors possess cubic zinc blende structures.

Synthesis and characterization of bis-thiourea having amino acid derivatives

NASA Astrophysics Data System (ADS)

Fakhar, Imran; Yamin, Bohari M.; Hasbullah, Siti Aishah

2016-11-01

In this article four new symmetric bis-thiourea derivatives having amino acid linkers were reported with good yield. Isophthaloyl dichloride was used as spacer and L-alanine, L-aspartic acid, L-phenylalanine and L-glutamic acid were used as linkers. Bis-thiourea derivatives were prepared from relatively stable isophthaloyl isothiocyanate intermediate. Newly synthesized bis-thiourea derivatives were characterized by FTIR, H-NMR, 13C-NMR and CHNS-O elemental analysis techniques. Characterization data was in good agreement with the expected derivatives, hence confirmed the synthesis of four new derivatives of bis-thiourea having amino acids.

Patterns of hydrogen bonding involving thiourea in the series of thioureaṡtrans-1,2-bispyridyl ethylene cocrystals - A comparative study

NASA Astrophysics Data System (ADS)

Kole, Goutam Kumar; Kumar, Mukesh

2018-07-01

Thiourea is known to act as a template to preorganise a series of trans-1,2-bispyridyl ethylenes (bpe), where the thiourea molecules present in an infinite zigzag chain with R22(8) graph set (the β-tape) which offers three different types of hydrogen bonding [J. Am. Chem. Soc. 132 (2010) 13434]. This article reports a new cocrystal of thiourea with 3,4‧-bpe and acts as a 'missing link' in the series. In this cocrystal, thiourea present in an infinite corrugated chain with R21(6) graph set, a rarely observed thiourea synthon i.e. α-tape. A comparative study has been discussed which demonstrates various types of hydrogen bonding that exist in the series and their impact on the parallel stacking of the pyridyl based olefins.

Enantioselective, Organocatalytic Reduction of Ketones using Bifunctional Thiourea-Amine Catalysts

PubMed Central

Li, De Run; He, Anyu; Falck, J. R.

2010-01-01

Prochiral ketones are reduced to enantioenriched, secondary alcohols using catecholborane and a family of air-stable, bifunctional thiourea-amine organocatalysts. Asymmetric induction is proposed to arise from the in situ complexation between the borane and chiral thiourea-amine organocatalyst resulting in a stereochemically biased boronate-amine complex. The hydride in the complex is endowed with enhanced nucleophilicity while the thiourea concomitantly embraces and activates the carbonyl. PMID:20334398

N,N',N"-tris(dihydroxyphosphorylmethyl)-1,4,7-triazacyclononane (Deofix) - a high-affinity, high-specificity chelator for first transition series metal cations with significant deodorant, antimicrobial, and antioxidant activity.

PubMed

Laden, Karl; Zaklad, Haim; Simhon, Elliot D; Klein, Joseph Y; Cyjon, Rosa L; Winchell, Harry S

2003-01-01

Deofix, N,N',N"-tris(dihydroxyphosphorylmethyl)-1,4,7-triazacyclononane, is a high-affinity, high-specificity chelator for first transition series cations such as iron, zinc, manganese, and copper. A 1% solution in 50% ethanol was found to be significantly better at reducing underarm malodor than a solution of 0.3% Triclosan in 50% ethanol. Compared to a 50% alcohol control, Deofix was found to produce a significant reduction in malodor for at least 48 hours. Deofix appears to work by reducing the concentration of first transition series metal ions below the levels needed for microbial cell reproduction and by inhibiting oxidative processes by interfering with catalytic formation of free radicals. Deofix has very low levels of toxicity when measured via a number of screening techniques.

Water-soluble porphyrins as a dual-function molecular imaging platform for MRI and fluorescence zinc sensing

PubMed Central

Zhang, Xiao-an; Lovejoy, Katherine S.; Jasanoff, Alan; Lippard, Stephen J.

2007-01-01

We report a molecular platform for dual-function fluorescence/MRI sensing of mobile zinc. Zinc-selective binding units were strategically attached to a water-soluble porphyrin template. The synthetic strategy for achieving the designed target ligand is flexible and convenient, and the key intermediates can be applied as general building blocks for the construction of other metal sensors based on a similar mechanism. The metal-free form, (DPA-C2)2-TPPS3 (1), where DPA is dipicolylamine and TPPS3 is 5-phenyl-10,15,20-tris(4-sulfonatophenyl)porphine, is an excellent fluorescent sensor for zinc. It has certain superior physical properties compared with earlier-generation zinc sensors including emission in the red and near-IR regions [λem = 645 nm (s) and 715 nm (m)], with a large Stokes shift of >230 nm. The fluorescence intensity of 1 increases by >10-fold upon zinc binding. The fluorescence “turn-on” is highly selective for zinc versus other divalent metal ions and is relatively pH-insensitive within the biologically relevant pH window. The manganese derivative, [(DPA-C2)2-TPPS3Mn(III)] (2), switches the function of the molecule to generate an MRI contrast agent. In the presence of zinc, the relaxivity of 2 in aqueous solution is significantly altered, which makes it a promising zinc MRI sensor. Both metal-free and Mn(III)-inserted forms are efficiently taken up by live cells, and the intracellular zinc can be imaged by either fluorescence or MR, respectively. We anticipate that in vivo applications of the probes will facilitate a deeper understanding of the physiological roles of zinc and allow detection of abnormal zinc homeostasis for pathological diagnoses. PMID:17578918

The effect of zinc thickness on corrosion film breakdown of Colombian galvanized steel

NASA Astrophysics Data System (ADS)

Sandoval-Amador, A.; E Torres Ramirez, J.; Cabrales-Villamizar, P. A.; Laverde Cataño, D.; Y Peña-Ballesteros, D.

2017-12-01

This work studies the corrosion behaviour of Colombian galvanized steel in solutions of chloride and sulphate ions. The effect of the thickness and exposure time on the film’s breakdown susceptibility and protectiveness of the corrosion products were studied using potentiodynamic polarization curves and electrochemical impedance spectroscopy. The corrosion products were analysed using SEM-EDS and XRD. The samples with a higher thickness level in the zinc film (Z180) have the lowest corrosion rate. In this case, one of the products that was formed by the chemical reactions that occurred was Zinc hydroxide, which exhibits a passive behaviour as observed in the Pourbaix curves of the obtained potentials and in how the different Ph levels of the solutions worked. The sheets with the highest thickness (Z180) had the best performance, since at the end of the study they showed the least amount of damage on the surface of the zinc layer. This is because the thickness of the zinc layer favours the formation of simonkolleite, which is the corrosion product that protects the material under the conditions of the study.

3'-phosphoadenosine-5'-phosphosulphate synthesis and involvement in sulphotransferase reactions in the insect, Spodoptera littoralis.

PubMed Central

Isaac, R E; Phua, K K; Rees, H H

1982-01-01

1. Synthesis of 3'-phosphoadenosine-5'-phosphosulphate from ATP and 35SO4(-2) was demonstrated by homogenates of gut. Malpighian tubules and fat body of Spodoptera littoralis. 2. The enzyme system was most active in the gut tissue, and was primarily located in the cytosol fraction of the cell. Gut cytosol preparations were used as a source of the 3'-phosphoadenosine-5'-phosphosulphate generating system for more detailed studies. 3. Maximum synthesis required an incubation mixture containing Tris/HCl buffer (pH 7.5), ATP (20 mM), MgCl2 (13.0 mM) and K2SO4 (3 mM). 4. The specific activity of 3'-phosphoadenosine-5'-phosphosulphate synthesizing activity in gut cytosol increased during development of the sixth instar larva, reaching a peak at day 4. A sudden fall in specific activity was observed in the prepupal stage. 5. 3'-Phosphoadenosine-5'-phosphosulphate formation is the rate limiting process in the overall sulphation of p-nitrophenol in the gut cytosol preparations from S. littoralis. 6. It is concluded that the properties of the sulphate-activating system in this insect are similar to those reported for vertebrates. PMID:6956335

Effect of hypophysectomy and thiourea treatment on radiophosphorus metabolism in goldfish, Carassius auratus L.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Srivastava, P. N.

1963-01-01

Goldfish, Carassius auratus L., were hypophysectomized. One month after the operation, hypophysectomized fish were divided into two groups, one of which was maintained in 0.3% thiourea solution. Control fish were also divided into two groups and maintained in 0.3% thiourea solution and fresh water. After two weeks P/sup 32/ was added in all the aquaria. Hypophysectomized fish maintained in fresh water utilized 39% of the P/sup 32/ in five days and the controls utilized 41% (the difference is not statistically significant). Hypophysectomized fish treated with thiourea utilized only 27% P/sup 32/ whereas the controls maintained in thiourea utilized 53%. Thismore » confirmed that increased P/sup 32/ utilization in thiourea solutions was caused by thyroid stimulation from the increased output of endogenous thyroid-stimulating hormone by the pituitary gland. (M.C.G.)« less

Studies on the intracellular Ca2+ concentration of thawed dog spermatozoa: influence of Equex from different sources, two thawing diluents and post-thaw incubation in capacitating conditions.

PubMed

Peña, A I; López-Lugilde, L; Barrio, M; Becerra, J J; Quintela, L A; Herradón, P G

2003-02-01

The addition of 0.5% (v/v) of Equex STM Paste (Nova Chemical Sales, Scituate Inc., MA, USA), whose active ingredient is sodium dodecyl sulphate (SDS), to a Tris-egg yolk extender was demonstrated to improve the longevity of frozen-thawed dog spermatozoa during in vitro incubation at 38 degrees C. The aim of the first experiment was to compare the effects of two SDS-containing compounds, Equex STM Paste and Equex Pasta (Minitüb, Tiefenbach, Germany), when added to a Tris-egg yolk based extender, on the post-thaw longevity of dog spermatozoa, as well as on the intracellular Ca2+ concentration of spermatozoa, during post-thaw incubation at 38 degrees C. The post-thaw sperm survival and longevity, as well as the quality of the sperm movement, were significantly better when using Equex STM Paste. Such prolonged sperm longevity, however, was associated to a higher intracellular Ca2+ concentration in a large subpopulation of the live spermatozoa. A second experiment was aimed to evaluate the effects of sperm dilution immediately post-thaw with a Tris buffer containing glucose or fructose. The two Tris buffers were no different for any of the sperm parameters studied. The aim of a third experiment was to evaluate the sperm longevity, motility patterns and intracellular Ca2+ concentration of cryopreserved dog spermatozoa during post-thaw incubation in capacitating conditions [canine capacitating medium (CCM) with or without 5 microg/ml of heparin]. Heparin had no significant effects on any of the sperm parameters evaluated. During the first 8 h of incubation, the majority of the live spermatozoa had a high intracellular Ca2+ content. However, after 8-10 h of incubation, it had significantly declined. The highest proportion of fast motile sperm, and the highest curvilinear velocity, average path velocity and amplitude of lateral head displacement for the total motile sperm were observed during the 2-4-h incubation period. It was concluded that: (a) the addition of 0.5% (v/v) of Equex STM Paste to a Tris-egg yolk based extender significantly improved the post-thaw longevity of dog spermatozoa, but the same concentration of Equex Pasta had no significant beneficial effects; (b) sperm dilution after thawing with a Tris buffer containing glucose or fructose made no difference in post-thaw sperm longevity; (c) the addition of 5 microg/ml of heparin to CCM had no significant capacitating effects on frozen-thawed dog spermatozoa.

Terbium to Quantum Dot FRET Bioconjugates for Clinical Diagnostics: Influence of Human Plasma on Optical and Assembly Properties

PubMed Central

Morgner, Frank; Stufler, Stefan; Geißler, Daniel; Medintz, Igor L.; Algar, W. Russ; Susumu, Kimihiro; Stewart, Michael H.; Blanco-Canosa, Juan B.; Dawson, Philip E.; Hildebrandt, Niko

2011-01-01

Förster resonance energy transfer (FRET) from luminescent terbium complexes (LTC) as donors to semiconductor quantum dots (QDs) as acceptors allows extraordinary large FRET efficiencies due to the long Förster distances afforded. Moreover, time-gated detection permits an efficient suppression of autofluorescent background leading to sub-picomolar detection limits even within multiplexed detection formats. These characteristics make FRET-systems with LTC and QDs excellent candidates for clinical diagnostics. So far, such proofs of principle for highly sensitive multiplexed biosensing have only been performed under optimized buffer conditions and interactions between real-life clinical media such as human serum or plasma and LTC-QD-FRET-systems have not yet been taken into account. Here we present an extensive spectroscopic analysis of absorption, excitation and emission spectra along with the luminescence decay times of both the single components as well as the assembled FRET-systems in TRIS-buffer, TRIS-buffer with 2% bovine serum albumin, and fresh human plasma. Moreover, we evaluated homogeneous LTC-QD FRET assays in QD conjugates assembled with either the well-known, specific biotin-streptavidin biological interaction or, alternatively, the metal-affinity coordination of histidine to zinc. In the case of conjugates assembled with biotin-streptavidin no significant interference with the optical and binding properties occurs whereas the histidine-zinc system appears to be affected by human plasma. PMID:22163719

Understanding the properties of chitosan aryl substituted thioureas in their role and potential as antibacterial agents

NASA Astrophysics Data System (ADS)

Khairul, Wan M.; Daud, Adibah Izzati; Ismail, Noraznawati

2018-02-01

In this study, the effort was to design and synthesize a series of thiourea-chitosan derivatives featuring five aryl substituted members namely N-chitosan-N'-(4-nitrobenzoyl) thiourea (1), N-chitosan-N'-(4-chlorobenzoyl) thiourea (2), N-chitosan-N'-(4-methylbenzoyl) thiourea (3), N-chitosan-N'-(2-iodobenzoyl) thiourea (4), and N-chitosan-N'-(2-methylbenzoyl) thiourea (5) via SN2 reaction pathway having different donating and withdrawing groups. Their molecular structures were then characterised by FT-IR, UV-Vis, and thermogravimetric analysis (TGA). The antimicrobial activities of these derivatives against four species bacteria Bacillus cereus, Staphylococcus aureus, Salmonella typhi, and Escherichia coli of both Gram-positive and Gram-negative type bacteria at minimum concentration 6mg/ml were carried out to investigate their potential as antibacterial agents. Compound 1 exhibited specific activity as it can only inhibit Gram-positive bacteria while other compounds 2-5 showed broad range spectrum activity as they were able to inhibit both Gram-positive and Gram-negative bacteria. Therefore, 1-5 showed good antibacterial activity and have high potential to be further developed as active materials in pharmaceutical interests.

Broadband Ftmw Spectroscopy of the Urea-Argon and Thiourea-Argon Complexes

NASA Astrophysics Data System (ADS)

Medcraft, Chris; Bittner, Dror M.; Cooper, Graham A.; Mullaney, John C.; Walker, Nick

2017-06-01

The rotational spectra complexes of argon-urea, argon-thiourea and water-thiourea have been measured by chirped-pulse Fourier transform microwave spectroscopy from 2-18.5 GHz. The sample was produced via laser vaporisation of a rod containing copper and the organic sample as a stream of argon was passed over the surface and subsequently expanded into the vacuum chamber cooling the sample. Argon was found to bind to π system of the carbonyl bond for both the urea and thiourea complexes.

Effect of Zinc Oxide Doping on Electroluminescence and Electrical Behavior of Metalloporphyrins-Doped Samarium Complex

NASA Astrophysics Data System (ADS)

Janghouri, Mohammad; Amini, Mostafa M.

2018-02-01

Samarium complex [(Sm(III)] as a new host material was used for preparation of red organic light-emitting diodes (OLEDs). Devices with configurations of indium-doped tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):(poly(styrenesulfonate) (PEDOT:PSS (50 nm)/polyvinyl carbazole (PVK):[zinc oxide (ZnO)] (50 nm)/[(Sm(III)]:[zinc(II) 2,3-tetrakis(dihydroxyphenyl)-porphyrin and Pt(II) 2,3-dimethoxyporphyrin] (60 nm)/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) (15 nm)/Al (150 nm) have been fabricated and investigated. An electroplex occurring at the (PVK/Sm: Pt(II) 2,3-dimethoxyporphyrin) interface has been suggested when ZnO nanoparticles were doped in PVK. OLED studies have revealed that the photophysical characteristics and electrical behavior of devices with ZnO nanoparticles are much better than those of devices with pure PVK. The efficiency of devices based on [(Sm(III)] was superior than that of known aluminum tris(8-hydroxyquinoline) (Alq3) and also our earlier reports on red OLEDs under the same conditions.

Study of the morphology of ZnS thin films deposited on different substrates via chemical bath deposition.

PubMed

Gómez-Gutiérrez, Claudia M; Luque, P A; Castro-Beltran, A; Vilchis-Nestor, A R; Lugo-Medina, Eder; Carrillo-Castillo, A; Quevedo-Lopez, M A; Olivas, A

2015-01-01

In this work, the influence of substrate on the morphology of ZnS thin films by chemical bath deposition is studied. The materials used were zinc acetate, tri-sodium citrate, thiourea, and ammonium hydroxide/ammonium chloride solution. The growth of ZnS thin films on different substrates showed a large variation on the surface, presenting a poor growth on SiO2 and HfO2 substrates. The thin films on ITO substrate presented a uniform and compact growth without pinholes. The optical properties showed a transmittance of about 85% in the visible range of 300-800 nm with band gap of 3.7 eV. © Wiley Periodicals, Inc.

Evaluation of the radiopacity of calcium silicate cements containing different radiopacifiers.

PubMed

Camilleri, J; Gandolfi, M G

2010-01-01

To identify the suitable ratio of alternative radiopacifiers to impart the necessary radiopacity to calcium silicate cements (CSC) and assess the purity of the radiopacifying agents. Alternative radiopacifying materials for incorporation into CSC included barium sulphate, titanium oxide, zinc oxide, gold powder and silver/tin alloy. The chemical composition of the alternative radipacifying materials and bismuth oxide, which is used in mineral trioxide aggregate (MTA), was determined using energy dispersive X-ray analysis. In addition, using an aluminium step-wedge and densitometer, the radiopacity of each material was evaluated as recommended by international standards. The optical density was compared with the relevant thickness of aluminium (Al). A commercial MTA and CSC were used as controls. Statistical analysis comparing the radiodensity of the different cements to MTA was performed using anova with P = 0.05 and post hoc Tukey test. All percentage replacements of bismuth oxide, gold and silver-tin alloy powder, and the 25% and 30% replacements with barium sulphate and zinc oxide had radiopacities greater than 3 mm thickness of aluminium (Al) recommended by ISO 6876 (2002). The 25% replacement of cement with gold powder and 20% replacement of cement with silver/tin alloy powder exhibited radiopacity values of 8.04 mm Al and 7.52 mm Al, respectively, similar to MTA (P > 0.05). The cement replaced with 20% bismuth oxide showed a radiopacity of 6.83 mm Al, lower than MTA (P = 0.003). Silver/tin alloy and gold powder imparted the necessary radiopacity to a calcium silicate-based cement. Barium sulphate was also a suitable radiopacifier together with a lower concentration of silver/tin alloy and gold powder that achieved the radiodensity recommended by ISO 6876. Further research is required to investigate the broader properties of the calcium silicate-based cement with the different radiopacifiers.

Delamination-restacking behaviour of surfactant intercalated layered hydroxy double salts, M 3Zn 2(OH) 8(surf) 2ṡ2H 2O [M = Ni, Co and surf = dodecyl sulphate (DS), dodecyl benzene sulphonate (DBS)

NASA Astrophysics Data System (ADS)

Rajamathi, Jacqueline T.; Ravishankar, N.; Rajamathi, Michael

2005-02-01

Surfactant anion intercalated nickel-zinc and cobalt-zinc layered hydroxy double salts were prepared through a modified acetate hydrolysis route. These organo-inorganic hybrids delaminate readily in alcohols such as 1-butanol to give stable translucent colloids. The extent of delamination and the stability of the colloids obtained are comparable to what has been observed in the case of layered double hydroxides (LDHs). The original layered solid could be obtained either by evaporation of the colloid or precipitation by the addition of a polar solvent such as acetone.

Understanding the conformational changes and molecular structure of furoyl thioureas upon substitution

NASA Astrophysics Data System (ADS)

Cairo, Raúl Ramos; Stevens, Ana María Plutín; de Oliveira, Tamires Donizeth; Batista, Alzir A.; Castellano, Eduardo E.; Duque, Julio; Soria, Delia B.; Fantoni, Adolfo C.; Corrêa, Rodrigo S.; Erben, Mauricio F.

2017-04-01

1-Acyl thioureas [R1C(O)NHC(S)NR2R3] are shown to display conformational flexibility depending on the degree of substitution at the nitrogen atom. The conformational landscape and structural features for two closely related thioureas having R1 = 2-furoyl have been studied. The un-substituted 2-furoyl thiourea (I) and its dimethyl analogue, i.e. 1-(2-furoyl)-3,3-dimethyl thiourea (II), have been synthesized and fully characterized by spectroscopic (FT-IR, 1H and 13C NMR) and elemental analysis. According to single crystal X-ray diffraction analysis, compounds I and II crystallize in the monoclinic space group P21/c. In the compound I, the trans-cis geometry of the almost planar thiourea unit is stabilized by intramolecular Nsbnd H ⋯ Odbnd C hydrogen bond between the H atom of the cis thioamide and the carbonyl O atom. In compound II, however, the acyl thiourea group is non-planar, in good agreement with the potential energy curve computed at the B3LYP/6-31 + G(d,p) level of approximation. Centrosymmetric dimers generated by intermolecular Nsbnd H ⋯ Sdbnd C hydrogen bond forming R22(8) motif are present in the crystals. Intermolecular interactions have been rationalized in terms of topological partitions of the electron distributions and Hirshfeld surface analysis, which showed the occurrence of S ⋯ H, O ⋯ H and H ⋯ H contacts that display an important role to crystal packing stabilization of both thiourea derivatives.

Corrosion behaviour and biocorrosion of galvanized steel water distribution systems.

PubMed

Delaunois, F; Tosar, F; Vitry, V

2014-06-01

Galvanized steel tubes are a popular mean for water distribution systems but suffer from corrosion despite their zinc or zinc alloy coatings. First, the quality of hot-dip galvanized (HDG) coatings was studied. Their microstructure, defects, and common types of corrosion were observed. It was shown that many manufactured tubes do not reach European standard (NBN EN 10240), which is the cause of several corrosion problems. The average thickness of zinc layer was found at 41μm against 55μm prescribed by the European standard. However, lack of quality, together with the usual corrosion types known for HDG steel tubes was not sufficient to explain the high corrosion rate (reaching 20μm per year versus 10μm/y for common corrosion types). Electrochemical tests were also performed to understand the corrosion behaviours occurring in galvanized steel tubes. Results have shown that the limiting step was oxygen diffusion, favouring the growth of anaerobic bacteria in steel tubes. EDS analysis was carried out on corroded coatings and has shown the presence of sulphur inside deposits, suggesting the likely bacterial activity. Therefore biocorrosion effects have been investigated. Actually sulphate reducing bacteria (SRB) can reduce sulphate contained in water to hydrogen sulphide (H2S), causing the formation of metal sulphides. Although microbial corrosion is well-known in sea water, it is less investigated in supply water. Thus, an experimental water main was kept in operation for 6months. SRB were detected by BART tests in the test water main. Copyright © 2014 Elsevier B.V. All rights reserved.

Novel thiourea-amine bifunctional catalysts for asymmetric conjugate addition of ketones/aldehydes to nitroalkenes: rational structural combination for high catalytic efficiency.

PubMed

Chen, Jia-Rong; Cao, Yi-Ju; Zou, You-Quan; Tan, Fen; Fu, Liang; Zhu, Xiao-Yu; Xiao, Wen-Jing

2010-03-21

A series of thiourea-amine bifunctional catalysts have been developed by a rational combination of prolines with cinchona alkaloids, which are connected by a thiourea motif. The catalyst 3a, prepared from L-proline and cinchonidine, was found to be a highly efficient catalyst for the conjugate addition of ketones/aldehydes to a wide range of nitroalkenes (up to 98/2 dr and 96% ee). The privileged cinchonidine backbone and the thiourea motif are essential to the reaction activity and enantioselectivity.

Repositioning of Thiourea-Containing Drugs as Tyrosinase Inhibitors.

PubMed

Choi, Joonhyeok; Jee, Jun-Goo

2015-12-02

Tyrosinase catalyzes two distinct sequential reactions in melanin biosynthesis: The hydroxylation of tyrosine to dihydroxyphenylalanine (DOPA) and the oxidation of DOPA to dopaquinone. Developing functional modulators of tyrosinase is important for therapeutic and cosmetic purposes. Given the abundance of thiourea moiety in known tyrosinase inhibitors, we studied other thiourea-containing drugs as potential tyrosinase inhibitors. The thiourea-containing drugs in clinical use were retrieved and tested for their ability to inhibit tyrosinase. We observed that methimazole, thiouracil, methylthiouracil, propylthiouracil, ambazone, and thioacetazone inhibited mushroom tyrosinase. Except for methimazole, there was limited information regarding the activity of other drugs against tyrosinase. Both thioacetazone and ambazone significantly inhibited tyrosinase, with IC50 of 14 and 15 μM, respectively. Ambazone decreased melanin content without causing cellular toxicity at 20 μM in B16F10 cells. The activity of ambazone was stronger than that of kojic acid both in enzyme and melanin content assays. Kinetics of enzyme inhibition assigned the thiourea-containg drugs as non-competitive inhibitors. The complex models by docking simulation suggested that the intermolecular hydrogen bond via the nitrogen of thiourea and the contacts via thione were equally important for interacting with tyrosinase. These data were consistent with the results of enzyme assays with the analogues of thiourea.

A novel thiourea type organocatalyst possessing a single NH functionality.

PubMed

Jovanovic, Predrag; Petkovic, Milos; Simic, Milena; Ivkovic, Branka; Savic, Vladimir

2016-07-12

A novel thiourea organocatalyst was rationally designed by altering a typical H-bonding pattern of thiourea derivatives and utilising the potential of the 3,5-bis(trifluoromethyl)phenyl motif to participate in the H-bond formation. This unique catalyst afforded the products of the α-amination and Michael reaction in excellent yields and with a high level of stereoselectivity. Although additional studies are necessary to establish the full potential of the catalyst and to broaden its application further, the presented results may indicate alternative routes for further exploration of the thiourea class of organocatalysts.

The extraction characteristic of Au-Ag from Au concentrate by thiourea solution

NASA Astrophysics Data System (ADS)

Kim, Bongju; Cho, Kanghee; On, Hyunsung; Choi, Nagchoul; Park, Cheonyoung

2013-04-01

The cyanidation process has been used commercially for the past 100 years, there are ores that are not amenable to treatment by cyanide. Interest in alternative lixiviants, such as thiourea, halogens, thiosulfate and malononitrile, has been revived as a result of a major increase in gold price, which has stimulated new developments in extraction technology, combined with environmental concern. The Au extraction process using the thiourea solvent has many advantages over the cyanidation process, including higher leaching rates, faster extraction time and less than toxicity. The purpose of this study was investigated to the extraction characteristic of Au-Ag from two different Au concentrate (sulfuric acid washing and roasting) under various experiment conditions (thiourea concentration, pH of solvent, temperature) by thiourea solvent. The result of extraction experiment showed that the Au-Ag extraction was a fast extraction process, reaching equilibrium (maximum extraction rate) within 30 min. The Au-Ag extraction rate was higher in the roasted concentrate than in the sulfuric acid washing. The higher the Au-Ag extraction rate (Au - 70.87%, Ag - 98.12%) from roasted concentrate was found when the more concentration of thiourea increased, pH decreased and extraction temperature increased. This study informs extraction method basic knowledge when thiourea was a possibility to eco-/economic resources of Au-Ag utilization studies including the hydrometallurgy.

PCDD/Fs' suppression by sulfur-amine/ammonium compounds.

PubMed

Fu, Jian-Ying; Li, Xiao-Dong; Chen, Tong; Lin, Xiao-Qing; Buekens, Alfons; Lu, Sheng-Yong; Yan, Jian-Hua; Cen, Ke-Fa

2015-03-01

Three distinct -S and -NH2 or NH4(+) containing compounds, including ammonium thiosulfate, aminosulfonic acid and thiourea, were studied as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) inhibitors. All these three -S and -N containing compounds tested show strong suppression of PCDD/Fs formation, especially for thiourea which has not been studied before. With a (S+N)/Cl molar ratio of only 0.47, thiourea could inhibit 97.3% of PCDD/Fs and even 99.8% of I-TEQ. At an unusually high de novo test temperature (650 °C), the PCDD/Fs' formation was still very low but also the inhibition capacity of thiourea was weak, with an efficiency of 59% for PCDD/Fs when with a (S+N)/Cl molar ratio of 1.40. The results also revealed that the inhibition capability of the combined -S/-NH2 or -S/NH4(+) suppressant was strongly influenced by both the nature of the functional group of nitrogen and the value of the molar ratio (S+N)/Cl. The amine functional group -NH2 tends to be more efficient than ammonium NH4(+) and within a certain range a higher (S+N)/Cl value leads to a higher inhibition efficiency. Moreover, the emission of gases was continuously monitored: the Gasmet results revealed that SO2, HCN and NH3 were the most important decomposition products of thiourea. Thiourea is non-toxic, environment-friendly and can be sprayed into the post-combustion zone in form of powder or aqueous solution. The cost of thiourea at least can be partially compensated by its high inhibition efficiency. Therefore, the application of thiourea in a full-scale incinerator system is promising and encouraging. Copyright © 2014 Elsevier Ltd. All rights reserved.

Crystalline perfection, optical and piezoelectric properties of a novel semi-organic single crystal: Zinc guanidinium sulphate

NASA Astrophysics Data System (ADS)

Nandhini, S.; Murugakoothan, P.

2018-04-01

Zinc Guanidinium Sulfate (ZGuS), a semi-organic single crystal, was synthesized using slow evaporation solution growth technique. It is a non-centrosymmetric crystal with space group I4 ¯2d . The crystalline nature of the crystal and the strain were determined using powder X-ray diffraction analysis. The crystalline perfection of the grown crystal was revealed using HR-XRD analysis. The UV-vis-NIR transmittance spectrum depicts 60% transparency with lower-cut off wavelength of 210 nm. The emission spectrum of the crystal was determined using photoluminescence study. Piezoelectricity was confirmed by determining the piezoelectric charge coefficient (d33). These findings shows that the title compound can be employed for photonic and transducer applications.

[Leaching of nonferrous metals from copper-smelting slag with acidophilic microorganisms].

PubMed

Murav'ev, M I; Fomchenko, N V

2013-01-01

The leaching process of copper and zinc from copper converter slag with sulphuric solutions of trivalent iron sulphate obtained using the association of acidophilic chemolithotrophic microorganisms was investigated. The best parameters of chemical leaching (temperature 70 degrees C, an initial concentration of trivalent iron in the leaching solution of 10.1 g/L, and a solid-phase content in the suspension of 10%) were selected. Carrying out the process under these parameters resulted in the recovery of 89.4% of copper and 39.3% of zinc in the solution. The possibility of the bioregeneration of trivalent iron in the solution obtained after the chemical leaching of slag by iron-oxidizingacidophilic chemolithotrophic microorganisms without inhibiting their activity was demonstrated.

Cooperative catalysis by tertiary amino-thioureas: mechanism and basis for enantioselectivity of ketone cyanosilylation.

PubMed

Zuend, Stephan J; Jacobsen, Eric N

2007-12-26

The mechanism of the enantioselective cyanosilylation of ketones catalyzed by tertiary amino-thiourea derivatives was investigated using a combination of experimental and theoretical methods. The kinetic analysis is consistent with a cooperative mechanism in which both the thiourea and the tertiary amine of the catalyst are involved productively in the rate-limiting cyanide addition step. Density functional theory calculations were used to distinguish between mechanisms involving thiourea activation of ketone or of cyanide in the enantioselectivity-determining step. The strong correlation obtained between experimental and calculated ee's for a range of substrates and catalysts provides support for the most favorable calculated transition structures involving amine-bound HCN adding to thiourea-bound ketone. The calculations suggest that enantioselectivity arises from direct interactions between the ketone substrate and the amino-acid derived portion of the catalyst. On the basis of this insight, more enantioselective catalysts with broader substrate scope were prepared and evaluated experimentally.

A highly efficient synthesis of the FGH ring of micrandilactone A. Application of thioureas as ligands in the Co-catalyzed Pauson-Khand reaction and Pd-catalyzed carbonylative annulation.

PubMed

Tang, Yefeng; Zhang, Yandong; Dai, Mingji; Luo, Tuoping; Deng, Lujiang; Chen, Jiahua; Yang, Zhen

2005-03-03

The functionalized FGH ring system of micrandilactone A was successfully constructed in high selectivity and good yields. The key reactions in our strategy are the Co-thiourea-catalyzed stereoselective, intramolecular Pauson-Khand reaction and Pd-thiourea-catalyzed stereoselective, intramolecular annulation. [structure: see text

Thiourea based novel chromogenic sensor for selective detection of fluoride and cyanide anions in organic and aqueous media.

PubMed

Kumar, Vinod; Kaushik, M P; Srivastava, A K; Pratap, Ajay; Thiruvenkatam, V; Row, T N Guru

2010-03-17

Novel chromogenic thiourea based sensors 4,4'-bis-[3-(4-nitrophenyl) thiourea] diphenyl ether 1 and 4,4'-bis-[3-(4-nitrophenyl) thiourea] diphenyl methane 2 having nitrophenyl group as signaling unit have been synthesized and characterized by spectroscopic techniques and X-ray crystallography. The both sensors show visual detection, UV-vis and NMR spectral changes in presence of fluoride and cyanide anions in organic solvent as well as in aqueous medium. The absorption spectra indicated the formation of complex between host and guest is in 1:2 stoichiometric ratios. Copyright 2010 Elsevier B.V. All rights reserved.

Thiourea incorporated poly(ethylene oxide) as transparent gel polymer electrolyte for dye sensitized solar cell applications

NASA Astrophysics Data System (ADS)

Pavithra, Nagaraj; Velayutham, David; Sorrentino, Andrea; Anandan, Sambandam

2017-06-01

A new series of transparent gel polymer electrolytes are prepared by adding various weight percent of thiourea coupled with poly(ethylene oxide) for the application of dye-sensitized solar cells. Coupling of thiourea in the presence of iodine undergoes dimerization reaction to produce formamidine disulfide. Fourier Transform Infrared spectroscopy shows that the interactions of thiourea and formamidine disulfide with electronegative ether linkage of poly(ethylene oxide) results in conformational changes of gel polymer electrolytes. Electrochemical impedance spectroscopy and linear sweep voltammetry experiments reveal an increment in ionic conductivity and tri-iodide diffusion coefficient, for thiourea modified gel polymer electrolytes. Finally, the prepared electrolytes are used as a redox mediator in dye-sensitized solar cells and the photovoltaic properties were studied. Apart from transparency, the gel polymer electrolytes with thiorurea show higher photovoltaic properties compared to bare gel polymer electrolyte and a maximum photocurrent efficiency of 7.17% is achieved for gel polymer electrolyte containing 1 wt% of thiourea with a short circuit current of 11.79 mA cm-2 and open circuit voltage of 834 mV. Finally, under rear illumination, almost 90% efficiency is retained upon compared to front illumination.

Crystal structure of papaya glutaminyl cyclase, an archetype for plant and bacterial glutaminyl cyclases.

PubMed

Wintjens, René; Belrhali, Hassan; Clantin, Bernard; Azarkan, Mohamed; Bompard, Coralie; Baeyens-Volant, Danielle; Looze, Yvan; Villeret, Vincent

2006-03-24

Glutaminyl cyclases (QCs) (EC 2.3.2.5) catalyze the intramolecular cyclization of protein N-terminal glutamine residues into pyroglutamic acid with the concomitant liberation of ammonia. QCs may be classified in two groups containing, respectively, the mammalian enzymes, and the enzymes from plants, bacteria, and parasites. The crystal structure of the QC from the latex of Carica papaya (PQC) has been determined at 1.7A resolution. The structure was solved by the single wavelength anomalous diffraction technique using sulfur and zinc as anomalous scatterers. The enzyme folds into a five-bladed beta-propeller, with two additional alpha-helices and one beta hairpin. The propeller closure is achieved via an original molecular velcro, which links the last two blades into a large eight stranded beta-sheet. The zinc ion present in the PQC is bound via an octahedral coordination into an elongated cavity located along the pseudo 5-fold axis of the beta-propeller fold. This zinc ion presumably plays a structural role and may contribute to the exceptional stability of PQC, along with an extended hydrophobic packing, the absence of long loops, the three-joint molecular velcro and the overall folding itself. Multiple sequence alignments combined with structural analyses have allowed us to tentatively locate the active site, which is filled in the crystal structure either by a Tris molecule or an acetate ion. These analyses are further supported by the experimental evidence that Tris is a competitive inhibitor of PQC. The active site is located at the C-terminal entrance of the PQC central tunnel. W83, W110, W169, Q24, E69, N155, K225, F22 and F67 are highly conserved residues in the C-terminal entrance, and their putative role in catalysis is discussed. The PQC structure is representative of the plants, bacterial and parasite enzymes and contrasts with that of mammalian enzymes, that may possibly share a conserved scaffold of the bacterial aminopeptidase.

Novel method for determination of zinc traces in beverages and water samples by solid surface fluorescence using a conventional quartz cuvette.

PubMed

Talio, María Carolina; Acosta, María Gimena; Acosta, Mariano; Olsina, Roberto; Fernández, Liliana P

2015-05-15

A new method for zinc pre-concentration/separation and determination by molecular fluorescence is proposed. The metal was complexed with o-phenanthroline and eosin at pH 7.5 in Tris; a piece of filter paper was used as a solid support and solid fluorescent emission measured using a conventional quartz cuvette. Under optimal conditions, the limits of detection and quantification were 0.36 × 10(-3) and 1.29 × 10(-3) μg L(-1), respectively, and the linear range from 1.29 × 10(-3) to 4.50 μg L(-1). This method showed good sensitivity and selectivity, and it was applied to the determination of zinc in foods and tap water. The absence of filtration reduced the consumption of water and electricity. Additionally, the use of common filter papers makes it a simpler and more rapid alternative to conventional methods, with sensitivity and accuracy similar to atomic spectroscopies using a typical laboratory instrument. Copyright © 2014 Elsevier Ltd. All rights reserved.

Thiourea in the Construction of C-S Bonds as Part of an Undergraduate Organic Chemistry Laboratory Course

ERIC Educational Resources Information Center

Lu, Guo-ping; Chen, Fei; Cai, Chun

2017-01-01

The nucleophilic aromatic substitution reaction and thia-Michael addition using thiourea as an odorless, cheap, and easy-to-handle sulfur source in water are described, which can be used to teach upper-division undergraduates the role of thiourea in the formation of C-S bonds and the principles of green chemistry. The use of a cheap, nontoxic…

Thiourea-catalyzed Diels–Alder reaction of a naphthoquinone monoketal dienophile

PubMed Central

Kramer, Carsten S

2013-01-01

Summary A variety of organocatalysts were screened for the catalysis of the naphthoquinone monoketal Diels–Alder reaction. In this study we found that Schreiner's thiourea catalyst 10 and Jacobson's thiourea catalyst 12 facilitate the cycloaddition of the sterically hindered naphthoquinone monoketal dienophile 3 with diene 4. The use of thiourea catalysis allowed for the first time the highly selective synthesis of the exo-product 2a in up to 63% yield. In this reaction a new quaternary center was built. The so formed cycloaddition product 2a represents the ABC tricycle of beticolin 0 (1) and is also a valuable model substrate for the total synthesis of related natural products. PMID:23946836

The effectiveness of a dentifrice without sodium lauryl sulphate on dental plaque and gingivitis - a randomized controlled clinical trial.

PubMed

Sälzer, S; Rosema, Nam; Hennequin-Hoenderdos, N L; Slot, D E; Timmer, C; Dörfer, C E; Van der Weijden, G A

2017-08-01

The purpose of the study was to evaluate the effect on dental plaque and gingivitis of a dentifrice without sodium lauryl sulphate (SLS) compared to two SLS-containing dentifrices. For this double-blind, parallel study, 90 volunteers having moderate gingival inflammation (≥40%) were randomly divided among three groups: one group using non-SLS dentifrice containing enzymes, colostrum and low concentrations of zinc and two control groups each using different SLS-containing dentifrices. Dental plaque scores (Turesky modification of Quigley & Hein) and gingivitis scores (Bleeding On Marginal Probing) were assessed at baseline, after 2 and 4 weeks. Eighty-nine participants provided evaluable data. A slight decrease in gingivitis scores was observed for all groups over 4 weeks, which was statistically significant for the non-SLS group. Mean values for dental plaque scores did not show major differences over 4 weeks. For both parameters, no significant differences between groups could be observed at any time point. Patient appreciation was in favour of the SLS groups especially regarding the foaming effect. No significant differences could be observed with respect to the effect on plaque and gingivitis between SLS-containing and SLS-free dentifrice containing enzymes, colostrum and low concentration zinc. Patients enjoyed the duration of taste and the 'foaming effect' of SLS-containing dentifrices better. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Optimizing protease production from an isolate of the nematophagous fungus Duddingtonia flagrans using response surface methodology and its larvicidal activity on horse cyathostomins.

PubMed

Braga, F R; Araújo, J V; Soares, F E F; Araujo, J M; Genier, H L A; Silva, A R; Carvalho, R O; Queiroz, J H; Ferreira, S R

2011-06-01

Protease production from Duddingtonia flagrans (isolate AC001) was optimized and the larvicidal activity of the enzymatic extract was evaluated on infective horse cyathostomin larvae (L3). Duddingtonia flagrans was grown in liquid medium with eight different variables: glucose, casein, bibasic potassium phosphate (K2HPO4), magnesium sulphate (MgSO4), zinc sulphate (ZnSO4), ferrous sulphate (FeSO4), copper sulphate (CuSO4) and temperature. The Plackett-Burman analysis showed a significant influence of MgSO4, CuSO4 and casein (P < 0.05) on protease production by D. flagrans in liquid medium. Central composite design indicated that the highest proteolytic activity was 39.56 U/ml as a function of the concentrations of casein (18.409 g/l), MgSO4 (0.10 g/l) and CuSO4 (0.50 mg/l). A significant difference (P < 0.01) was found for the larval number between the treated and control groups at the end of the experiment. A reduction of 95.46% in the number of free-living larvae was found in the treated group compared with the control. The results of this study suggest that protease production by D. flagrans (AC001) in liquid medium was optimized by MgSO4, CuSO4 and casein, showing that the optimized enzymatic extract exerted larvicidal activity on cyathostomins and therefore may contribute to large-scale industrial production.

Chelatable trace zinc causes low, irreproducible KDAC8 activity.

PubMed

Toro, Tasha B; Edenfield, Samantha A; Hylton, Brandon J; Watt, Terry J

2018-01-01

Acetylation is an important regulatory mechanism in cells, and emphasis is being placed on identifying substrates and small molecule modulators of this post-translational modification. However, the reported in vitro activity of the lysine deacetylase KDAC8 is inconsistent across experimental setups, even with the same substrate, complicating progress in the field. We detected trace levels of zinc, a known inhibitor of KDAC8 when present in excess, even in high-quality buffer reagents, at concentrations that are sufficient to significantly inhibit the enzyme under common reaction conditions. We hypothesized that trace zinc in solution could account for the observed variability in KDAC8 activity. We demonstrate that addition of chelators, including BSA, EDTA, and citrate, and/or the use of a phosphate-based buffer instead of the more common tris-based buffer, eliminates the inhibition from low levels of zinc as well as the dependence of specific activity on enzyme concentration. This results in high KDAC8 activity that is consistent across buffer systems, even using low concentrations of enzyme. We report conditions that are suitable for several assays to increase both enzyme activity and reproducibility. Our results have significant implications for approaches used to identify substrates and small molecule modulators of KDAC8 and interpretation of existing data. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of zinc and benzene on respiration and excretion of mussel larvae (Perna perna) (Linnaeus, 1758) (Mollusca; Bivalvia).

PubMed

Jorge, R A D L V C; Lemos, D; Moreira, G S

2007-02-01

The presence of pollutants in the ocean may affect different physiological parameters of animals. Oxygen consumption and ammonia excretion were evaluated in D-shaped larvae of mussels (Perna perna) exposed to zinc sulphate (ZnSO(4)) and benzene (C(6)H(6)). When compared to the control group, both pollutants presented a significant reduction in oxygen consumption. A reduction in the ammonia excretion was also observed, both for ZnSO(4) and C(6)H(6) and also in the oxygen consumption. The results indicate that anaerobic metabolism may occur at the beginning of P. perna mussels development, as observed in veliger larvae. The O:N ratio under experimental conditions showed low values indicating that catabolism in veliger larvae was predominantly proteic.

Synthesis, characterization, X-ray crystal structure, DFT calculation and antibacterial activities of new vanadium(IV, V) complexes containing chelidamic acid and novel thiourea derivatives.

PubMed

Farzanfar, Javad; Ghasemi, Khaled; Rezvani, Ali Reza; Delarami, Hojat Samareh; Ebrahimi, Ali; Hosseinpoor, Hona; Eskandari, Amir; Rudbari, Hadi Amiri; Bruno, Giuseppe

2015-06-01

Three new thiourea ligands derived from the condensation of aroyl- and aryl-isothiocyanate derivatives with 2,6-diaminopyridine, named 1,1'-(pyridine-2,6-diyl)bis(3-(benzoyl)thiourea) (L1), 1,1'-(pyridine-2,6-diyl)bis(3-(2-chlorobenzoyl)thiourea) (L2) and 1,1'-(pyridine-2,6-diyl)bis(3-(4-chlorophenyl)thiourea) (L3), their oxido-vanadium(IV) complexes, namely [VO(L1('))(H2O)] (C1), [VO(L2('))(H2O)] (C2) and [VO(L3('))(H2O)] (C3), and also, dioxo-vanadium(V) complex containing 4-hydroxy-2,6-pyridine dicarboxylic acid (chelidamic acid, H2dipic-OH) and metformin (N,N-dimethylbiguanide, Met), named [H2Met][VO2(dipic-OH)]2·H2O (C4), were synthesized and characterized by elemental analysis, FTIR and (1)H NMR and UV-visible spectroscopies. Proposed structures for free thiourea ligands and their vanadium complexes were corroborated by applying geometry optimization and conformational analysis. Solid state structure of complex [H2Met][VO2(dipic-OH)]2·H2O (triclinic, Pī) was fully determined by single crystal X-ray diffraction analysis. In this complex, metformin is double protonated and acted as counter ion. The antibacterial properties of these compounds were investigated in vitro against standard Gram-positive and Gram-negative bacterial strains. The experiments showed that vanadium(IV) complexes had the superior antibacterial activities than novel thiourea derivatives and vanadium(V) complex against all Gram-positive and Gram-negative bacterial strains. Copyright © 2015 Elsevier Inc. All rights reserved.

Influence of thiourea application on some physiological and molecular criteria of sunflower (Helianthus annuus L.) plants under conditions of heat stress.

PubMed

Akladious, Samia Ageeb

2014-05-01

High temperature is a major factor limiting the growth of plant species during summer. Understanding the mechanisms of plant tolerance to high temperature would help in developing effective management practices and heat-tolerant cultivars through breeding or biotechnology. The present investigation was carried out to study the role of thiourea in enhancing the tolerance of sunflower plants to heat stress. Sunflower plants were subjected to temperature stress by exposing plants to 35 or 45 °C for 12 h. Two levels of thiourea (10 and 20 mM) were applied before sowing (seed treatment). The results indicated that the plants exposed to temperature stress exhibited a significant decline in growth parameters, chlorophylls, relative leaf water content, oil content, leaf nutrient status, and nitrate reductase activity. Treatment with thiourea, especially when applied at 10 mM, improved the above parameters and induced non-enzymatic and enzymatic antioxidants responsible for antioxidation. SDS-PAGE of protein revealed that high-temperature treatments alone or in combination with thiourea were associated with the disappearance of some bands or the appearance of unique ones. The result of RAPD analysis using five primers showed variable qualitative and quantitative changes. These findings confirm the effectiveness of applying thiourea on alleviating heat injuries in sunflower plants.

Real-Time in Vivo Detection of H2O2 Using Hyperpolarized 13C-Thiourea.

PubMed

Wibowo, Arif; Park, Jae Mo; Liu, Shie-Chau; Khosla, Chaitan; Spielman, Daniel M

2017-07-21

Reactive oxygen species (ROS) are essential cellular metabolites widely implicated in many diseases including cancer, inflammation, and cardiovascular and neurodegenerative disorders. Yet, ROS signaling remains poorly understood, and their measurements are a challenge due to high reactivity and instability. Here, we report the development of 13 C-thiourea as a probe to detect and measure H 2 O 2 dynamics with high sensitivity and spatiotemporal resolution using hyperpolarized 13 C magnetic resonance spectroscopic imaging. In particular, we show 13 C-thiourea to be highly polarizable and to possess a long spin-lattice relaxation time (T 1 ), which enables real-time monitoring of ROS-mediated transformation. We also demonstrate that 13 C-thiourea reacts readily with H 2 O 2 to give chemically distinguishable products in vitro and validate their detection in vivo in a mouse liver. This study suggests that 13 C-thiourea is a promising agent for noninvasive detection of H 2 O 2 in vivo. More broadly, our findings outline a viable clinical application for H 2 O 2 detection in patients with a range of diseases.

Determination of thiourea in fruit juice by a kinetic spectrophotometric method.

PubMed

Abbasi, Shahryar; Khani, Hossein; Hosseinzadeh, Laleh; Safari, Zhila

2010-02-15

A catalytic kinetic method is described for determination of trace levels of thiourea based on its catalytic effect on the oxidation of Janus green (JG) by potassium iodate in hydrochloric acid media. The reaction was monitored by measuring the decrease in absorbance of the dye at 610 nm after 25 min. The effect of some factors on the reaction speed was investigated. The developed method allowed the determination of thiourea in range of 0.01-12.00 mg L(-1) with good precision, accuracy and the detection limit was 0.008 mg L(-1). Most of foreign species do not interfere with the determination. The method was found to be sensitive, selective and was applied to the determination of thiourea in fruit juices and orange peel.

Detection of Orexin A Neuropeptide in Biological Fluids Using a Zinc Oxide Field Effect Transistor

DTIC Science & Technology

2012-06-01

can rapidly cross the blood-brain barrier10. In contrast, orexin B has low lipophilicity and is rapidly metabolized in blood which makes it difficult...Tris (Sigma) pH 9.1. The eluate was added to 20 mL E. coli ER2738 culture and incubated at 37 ºC with vigorous shaking for 4.5 h. The culture was...plates using a sterile inoculation loops, and were amplified individually for 4.5-5 hours at 37 ºC in 1.5 mL of E. coli ER2738 culture grown in LB broth

Zinc Improves Cognitive and Neuronal Dysfunction During Aluminium-Induced Neurodegeneration.

PubMed

Singla, Neha; Dhawan, D K

2017-01-01

Metals are considered as important components of a physiologically active cell, and imbalance in their levels can lead to various diseased conditions. Aluminium (Al) is an environmental neurotoxicant, which is etiologically related to several neurodegenerative disorders like Alzheimer's, whereas zinc (Zn) is an essential trace element that regulates a large number of metabolic processes in the brain. The objective of the present study was to understand whether Zn provides any physiological protection during Al-induced neurodegeneration. Male Sprague Dawley rats weighing 140-160 g received either aluminium chloride (AlCl 3 ) orally (100 mg/kg b.wt./day), zinc sulphate (ZnSO 4 ) in drinking water (227 mg/L) or combined treatment of aluminium and zinc for 8 weeks. Al treatment resulted in a significant decline in the cognitive behaviour of rats, whereas zinc supplementation caused an improvement in various neurobehavior parameters. Further, Al exposure decreased (p ≤ 0.001) the levels of neurotransmitters, acetylcholinesterase activity, but increased (p ≤ 0.001) the levels of L-citrulline as well as activities of nitric oxide and monoamine oxidase in the brain. However, zinc administration to Al-treated animals increased the levels of neurotransmitters and regulated the altered activities of brain markers. Western blot of tau, amyloid precursor protein (APP), glial fibrillary acidic protein (GFAP), ubiquitin, α-synuclein and Hsp 70 were also found to be elevated after Al exposure, which however were reversed following Zn treatment. Al treatment also revealed alterations in neurohistoarchitecture in the form of loss of pyramidal and Purkinje cells, which were improved upon zinc co-administration. Therefore, the present study demonstrates that zinc improves cognitive functions by regulating α-synuclein and APP-mediated molecular pathways during aluminium-induced neurodegeneration.

Potentiated virucidal activity of pomegranate rind extract (PRE) and punicalagin against Herpes simplex virus (HSV) when co-administered with zinc (II) ions, and antiviral activity of PRE against HSV and aciclovir-resistant HSV

PubMed Central

Houston, David M. J.; Bugert, Joachim J.; Denyer, Stephen P.

2017-01-01

Background There is a clinical need for new therapeutic products against Herpes simplex virus (HSV). The pomegranate, fruit of the tree Punica granatum L, has since ancient times been linked to activity against infection. This work probed the activity of pomegranate rind extract (PRE) and co-administered zinc (II) ions. Materials and methods PRE was used in conjunction with zinc (II) salts to challenge HSV-1 and aciclovir-resistant HSV in terms of virucidal plaque assay reduction and antiviral activities in epithelial Vero host cells. Cytotoxicity was determined by the MTS assay using a commercial kit. Results Zinc sulphate, zinc citrate, zinc stearate and zinc gluconate demonstrated similar potentiated virucidal activity with PRE against HSV-1 by up to 4-fold. A generally parabolic relationship was observed when HSV-1 was challenged with PRE and varying concentrations of ZnSO4, with a maximum potentiation factor of 5.5. Punicalagin had 8-fold greater virucidal activity than an equivalent mass of PRE. However, antiviral data showed that punicalagin had significantly lower antiviral activity compared to the activity of PRE (EC50 = 0.56 μg mL-1) a value comparable to aciclovir (EC50 = 0.18 μg mL-1); however, PRE also demonstrated potency against aciclovir-resistant HSV (EC50 = 0.02 μg mL-1), whereas aciclovir showed no activity. Antiviral action of PRE was not influenced by ZnSO4. No cytotoxicity was detected with any test solution. Conclusions The potentiated virucidal activity of PRE by coadministered zinc (II) has potential as a multi-action novel topical therapeutic agent against HSV infections, such as coldsores. PMID:28665969

Characterization of dross and its recovery by sulphuric acid leaching

NASA Astrophysics Data System (ADS)

Rahmani, S. A.; Meidianto, A.; Amal, M. I.; Wismogroho, A. S.; Widayatno, W. B.

2018-03-01

This paper reports the characterization of dross from galvanizing process and its recovery using acidic leaching method. The diffraction profile of dross showed identical peaks with that of ZnO. The X-ray Fluorescence (XRF) analysis identified the content of following metals: Zn, Fe, Mn, Ga, Co, and W. The thermal behaviour examination revealed the existence of some volatiles within the initial sample. The acidic leaching at various concentrations of sulphuric acid was conducted to determine the optimum concentration for zinc recovery and the highest yield of zinc sulphate. It is concluded that the optimum concentration of H2SO4 for this kind of dross is 4 M with 71.9% yield of ZnSO4. The result of leaching process was confirmed by infrared spectrum, where various absorptions corresponding to SO4 2- and Zn-O bands were observed.

Recovery of Precious and Base Metals from Waste Printed Circuit Boards Using a Sequential Leaching Procedure

NASA Astrophysics Data System (ADS)

Batnasan, Altansukh; Haga, Kazutoshi; Shibayama, Atsushi

2018-02-01

This paper considers the issue of recycling of waste printed circuit boards (WPCBs) containing precious and base metals in appreciable amounts. High-pressure oxidative leaching (HPOL) with dilute sulfuric acid resulted in removal of a significant amount of base metals from a WPCB ash sample obtained by incineration at 800°C. The parameters investigated in the precious metal leaching from WPCB residue after HPOL included the sulfuric acid concentration, thiourea concentration, oxidant concentration, leaching temperature, and leaching time. Recovery of gold, silver, and palladium of 100%, 81%, and 13% from the WPCB residue sample was achieved by thiourea leaching under optimized conditions. The results show that the efficiency of precious metal dissolution from the WPCB sample using thiourea solution depended strongly on the concentration of both thiourea and oxidant.

Recovery of Precious and Base Metals from Waste Printed Circuit Boards Using a Sequential Leaching Procedure

NASA Astrophysics Data System (ADS)

Batnasan, Altansukh; Haga, Kazutoshi; Shibayama, Atsushi

2017-12-01

This paper considers the issue of recycling of waste printed circuit boards (WPCBs) containing precious and base metals in appreciable amounts. High-pressure oxidative leaching (HPOL) with dilute sulfuric acid resulted in removal of a significant amount of base metals from a WPCB ash sample obtained by incineration at 800°C. The parameters investigated in the precious metal leaching from WPCB residue after HPOL included the sulfuric acid concentration, thiourea concentration, oxidant concentration, leaching temperature, and leaching time. Recovery of gold, silver, and palladium of 100%, 81%, and 13% from the WPCB residue sample was achieved by thiourea leaching under optimized conditions. The results show that the efficiency of precious metal dissolution from the WPCB sample using thiourea solution depended strongly on the concentration of both thiourea and oxidant.

Mechanism of amido-thiourea catalyzed enantioselective imine hydrocyanation: transition state stabilization via multiple non-covalent interactions.

PubMed

Zuend, Stephan J; Jacobsen, Eric N

2009-10-28

An experimental and computational investigation of amido-thiourea promoted imine hydrocyanation has revealed a new and unexpected mechanism of catalysis. Rather than direct activation of the imine by the thiourea, as had been proposed previously in related systems, the data are consistent with a mechanism involving catalyst-promoted proton transfer from hydrogen isocyanide to imine to generate diastereomeric iminium/cyanide ion pairs that are bound to catalyst through multiple noncovalent interactions; these ion pairs collapse to form the enantiomeric alpha-aminonitrile products. This mechanistic proposal is supported by the observation of a statistically significant correlation between experimental and calculated enantioselectivities induced by eight different catalysts (P < 0.01). The computed models reveal a basis for enantioselectivity that involves multiple stabilizing and destabilizing interactions between substrate and catalyst, including thiourea-cyanide and amide-iminium interactions.

Synthesis, antibacterial and anti-MRSA activity, in vivo toxicity and a structure-activity relationship study of a quinoline thiourea.

PubMed

Dolan, Niamh; Gavin, Declan P; Eshwika, Ahmed; Kavanagh, Kevin; McGinley, John; Stephens, John C

2016-01-15

We report the synthesis, antibacterial evaluation of a series of thiourea-containing compounds. 1-(3,5-Bis(trifluoromethyl)phenyl)-3-((S)-(6-methoxyquinolin-4-yl)-((1S,2S,4S,5R)-5-vinylquinuclidin-2-yl)methyl)thiourea 5, was the most active against a range of Gram-positive and Gram-negative bacteria, and exhibited bacteriostatic activity against methicillin resistant Staphylococcus aureus (MRSA) comparable to that of the well-known antibacterial agent vancomycin. Quinoline thiourea 5 was subjected to a detailed structure-activity relationship study, with 5 and its derivatives evaluated for their bacteriostatic activity against both Gram-negative and Gram-positive bacteria. A number of structural features important for the overall activity of quinoline thiourea 5 have been identified. A selection of compounds, including 5, was also evaluated for their in vivo toxicity using the larvae of the Greater wax moth, Galleria mellonella. Compound 5, and a number of derivatives, were found to be non-toxic to the larvae of Galleria mellonella. A new class of antibiotic can result from the further development of this family of compounds. Copyright © 2015 Elsevier Ltd. All rights reserved.

DNA-binding studies and biological activities of new nitrosubstituted acyl thioureas

NASA Astrophysics Data System (ADS)

Tahir, Shaista; Badshah, Amin; Hussain, Raja Azadar; Tahir, Muhammad Nawaz; Tabassum, Saira; Patujo, Jahangir Ali; Rauf, Muhammad Khawar

2015-11-01

Four new nitrosubstituted acylthioureas i.e. 1-acetyl-3-(4-nitrophenyl)thiourea (TU1), 1-acetyl-3-(2-methyl-4-nitrophenyl)thiourea (TU2), 1-acetyl-3-(2-methoxy-4-nitrophenyl)thiourea (TU3) and 1-acetyl-3-(4-chloro-3-nitrophenyl)thiourea (TU4) have been synthesized and characterized (by C13 and H1 nuclear magnetic resonance, Fourier transform infrared spectroscopy and single crystal X-ray diffraction). As a preliminary investigation of the anti-cancer potencies of the said compounds, DNA interaction studies have been carried out using cyclic voltammetry and UV-vis spectroscopy along with verification from computational studies. The drug-DNA binding constants are found to be in the order, KTU3 9.04 × 106 M-1 > KTU4 8.57 × 106 M-1 > KTU2 6.05 × 106 M-1 > KTU1 1.16 × 106 M-1. Furthermore, the antioxidant, cytotoxic, antibacterial and antifungal activities have been carried out against DPPH (1,1-diphenyl-2-dipicrylhydrazyl), Brine shrimp eggs, gram positive (Micrococcus luteus, Staphylococcus aureus) and gram negative (Bordetella bronchiseptica, Salmonella typhimurium, Enterobacter aerogens) and fungal cultures (Aspergillus fumigatus, Mucor species, Aspergillus niger, Aspergillus flavus) respectively.

Effect of Dietary Zinc Oxide on Morphological Characteristics, Mucin Composition and Gene Expression in the Colon of Weaned Piglets

PubMed Central

Liu, Ping; Pieper, Robert; Rieger, Juliane; Vahjen, Wilfried; Davin, Roger; Plendl, Johanna; Meyer, Wilfried; Zentek, Jürgen

2014-01-01

The trace element zinc is often used in the diet of weaned piglets, as high doses have resulted in positive effects on intestinal health. However, the majority of previous studies evaluated zinc supplementations for a short period only and focused on the small intestine. The hypothesis of the present study was that low, medium and high levels of dietary zinc (57, 164 and 2,425 mg Zn/kg from zinc oxide) would affect colonic morphology and innate host defense mechanisms across 4 weeks post-weaning. Histological examinations were conducted regarding the colonic morphology and neutral, acidic, sialylated and sulphated mucins. The mRNA expression levels of mucin (MUC) 1, 2, 13, 20, toll-like receptor (TLR) 2, 4, interleukin (IL)-1β, 8, 10, interferon-γ (IFN-γ) and transforming growth factor-β (TGF-β) were also measured. The colonic crypt area increased in an age-depending manner, and the greatest area was found with medium concentration of dietary zinc. With the high concentration of dietary zinc, the number of goblet cells containing mixed neutral-acidic mucins and total mucins increased. Sialomucin containing goblet cells increased age-dependently. The expression of MUC2 increased with age and reached the highest level at 47 days of age. The expression levels of TLR2 and 4 decreased with age. The mRNA expression of TLR4 and the pro-inflammatory cytokine IL-8 were down-regulated with high dietary zinc treatment, while piglets fed with medium dietary zinc had the highest expression. It is concluded that dietary zinc level had a clear impact on colonic morphology, mucin profiles and immunological traits in piglets after weaning. Those changes might support local defense mechanisms and affect colonic physiology and contribute to the reported reduction of post-weaning diarrhea. PMID:24609095

Synthesis, growth, structural, spectroscopic and optical studies of a semiorganic NLO crystal: zinc guanidinium phosphate.

PubMed

Suvitha, A; Murugakoothan, P

2012-02-01

The semi-organic nonlinear optical (NLO) crystal, zinc guanidinium phosphate (ZGuP) has been grown through synthesis between zinc sulphate, guanidine carbonate and orthophosphoric acid from its aqueous solution by slow solvent evaporation technique. Solubility of the synthesized material has been determined for various temperatures using water as solvent. The grown crystal has been characterized by powder X-ray diffraction to confirm the crystal structure. Investigation has been carried out to assign the vibrational frequencies of the grown crystals by Fourier transform infrared spectroscopy technique. (1)H and (13)C FT-NMR have been recorded to elucidate the molecular structure. The optical absorption study confirms the suitability of the crystal for device applications. The second harmonic generation (SHG) efficiency of ZGuP is found to be 1.825 times that of potassium dihydrogen phosphate (KDP). Thermal behavior of the grown crystals has been studied by thermogravimetric and differential thermal analysis. The mechanical properties of the grown crystals have been studied using Vickers microhardness tester. Copyright © 2011 Elsevier B.V. All rights reserved.

Improved performance of low cost CuInS2 superstrate-type solar cells using Zinc assisted spray pyrolysis processing

NASA Astrophysics Data System (ADS)

Cheshme Khavar, Amir Hossein; Mahjoub, Ali Reza; Taghavinia, Nima

2017-12-01

Superstrate configuration CuInS2 (CIS) solar cells are fabricated using a spray pyrolysis method. We avoided selenization process, cyanide etching and CdS buffer layer, to keep the process ‘green’. CIS layers are formed by spray pyrolysis of an aqueous precursor ink containing metal chloride salts and thiourea at 350 °C. We investigated the effect of intentional Zn doping on structural, morphological and photovoltaic response of the fabricated CIS films by dissolving ZnCl2 in aqueous precursor solution. At a zinc doping level ranging between 0.25 and 1.00 mol%, Zn doping is found to improve the CIS crystal growth and surface morphology of CIS films. Compared with the performance of the non-doped CIS cell, the Zn-doped CIS solar cell displayed a remarkable efficiency enhancement of 58-97% and the maximum enhancement was obtained at a Zn content of 0.5 mol%. The device structure consists of    and show promising PCE of 4.29 % without any anti-reflection coating. Over the course of 300 d under ambient condition, the fabricated device showed only 1% loss in efficiency.

Kinetics of the Reduction of Cadmium Sulfate by Thiourea Dioxide in an Aqueous Ammonia Solution upon the Metallization of Carbon Fiber

NASA Astrophysics Data System (ADS)

Polenov, Yu. V.; Egorova, E. V.; Shestakov, G. A.

2018-01-01

The kinetics of the decomposition of thiourea dioxide and the reduction of cadmium cations by thiourea dioxide in an aqueous ammonia solution are studied. The kinetic parameters of these reactions are calculated using experimental data, allowing us to adjust conditions for the synthesis of cadmium coatings on carbon fiber of grade UKN-M-12K. The presence of the metal crystalline phase on the fiber is confirmed by means of X-ray diffraction, and its amount is measured via atomic absorption spectroscopy.

Enhancement of osteogenic differentiation of rat adipose tissue-derived mesenchymal stem cells by zinc sulphate under electromagnetic field via the PKA, ERK1/2 and Wnt/β-catenin signaling pathways

PubMed Central

Fathi, Ezzatollah; Farahzadi, Raheleh

2017-01-01

Zinc ion as an essential trace element and electromagnetic fields (EMFs) has been reported to be involved in the regulation of bone metabolism. The aim of this study was to elucidate the effects of zinc sulphate (ZnSO4) on the osteogenic differentiation of adipose tissue-derived mesenchymal stem cells (ADSCs) in the presence of EMF as a strategy in osteoporosis therapy. Alkaline phophatase (ALP) activity measurement, calcium assay and expression of several osteoblastic marker genes were examined to assess the effect of ZnSO4 on the osteogenic differentiation of ADSCs under EMF. The expression of cAMP and PKA was evaluated by ELISA. The expression of β-catenin, Wnt1, Wnt3a, low-density lipoprotein receptor-related protein 5 (LRP5) and reduced dickkopf1 (DKK1) genes were used to detect the Wnt/β-catenin pathway. It was found that ZnSO4, in the presence of EMF, resulted in an increase in the expression of osteogenic genes, ALP activity and calcium levels. EMF, in the presence of ZnSO4, increased the cAMP level and protein kinase A (PKA) activity. Treatment of ADSCs with (MAPK)/ERK kinase 1/2 inhibitor, or PKA inhibitor, significantly inhibited the promotion of osteogenic markers, indicating that the induction of osteogenesis was dependent on the ERK and PKA signaling pathways. Real-time PCR analysis showed that ZnSO4, in the presence of EMF, increased the mRNA expressions of β-catenin, Wnt1, Wnt3a, LRP5 and DKK1. In this study, it was shown that 0.432 μg/ml ZnSO4, in the presence of 50 Hz, 20 mT EMF, induced the osteogenic differentiation of ADSCs via PKA, ERK1/2 and Wnt/β-catenin signaling pathways. PMID:28339498

Hydrothermal synthesis and magnetic properties of Mn doped ZnS nanoparticles

NASA Astrophysics Data System (ADS)

Rashad, M. M.; Rayan, D. A.; El-Barawy, K.

2010-01-01

Nanocrystallite Mn doped Zn1-XS (X = 0 to 0.4) powders have been synthesized through a hydrothermal route. The effect of the hydrothermal temperature and Mn2+ ions substitution on the crystal structure, crystallite size, microstructure and magnetic properties were investigated using (XRD), (SEM) and (VSM). The results revealed that wurtzite zinc sulfide phase was formed using thiourea as a sulfur source at temperature 150- 200oC for 24 h. The crystallite size was (7.9-15.1 nm) was obtained at the same conditions. The doping of Mn2+ ions decreased the crystallite size of the formed ZnS wurtzite phase was in the range between 7.9 and 3.8 nm. SEM micrographs showed that the produced ZnS and Mn doped ZnS particles were appeared as spherical shape. The magnetic properties were improved by substitution of Mn2+ ions up to 0.2.

A hexa-quinoline based C3-symmetric chemosensor for dual sensing of zinc(ii) and PPi in an aqueous medium via chelation induced "OFF-ON-OFF" emission.

PubMed

Sinha, Sanghamitra; Chowdhury, Bijit; Adarsh, Nayarassery N; Ghosh, Pradyut

2018-05-15

A quinoline-based C3-symmetric fluorescent probe (1), N,N',N''-((2,4,6-trimethylbenzene-1,3,5-triyl)tris(methylene))tris(1-(quinolin-2-yl)-N-(quinolin-2-ylmethyl)methanamine), has been developed which can selectively detect Zn2+ without the interference of Cd2+via significant enhancement in emission intensity (fluorescence "turn-ON") associated with distinct fluorescence colour changes and very low detection limits (35.60 × 10-9 M in acetonitrile and 29.45 × 10-8 M in 50% aqueous buffer (10 mM HEPES, pH = 7.4) acetonitrile media). Importantly, this sensor is operative with a broad pH window (pH 4-10). The sensing phenomenon has been duly studied through UV-vis, steady-state, and time-resolved fluorescence spectroscopic methods indicating 1 : 3 stoichiometric binding between 1 and Zn2+ which is further corroborated by 1H NMR studies. Density functional theoretical (DFT) calculations provide the optimized molecular geometry and properties of the zinc complex, 1[Zn(ClO4)]33+, which is proposed to be formed in acetonitrile. The results are in line with the solution-state experimental findings. The single crystal X-ray study provides the solid state structure of the trinuclear Zn2+ complex showing solubility in an aqueous buffer (10 mM HEPES, pH = 7.4). Finally, the resulting trinuclear Zn2+ complex has been utilized as a fluorescence "turn-OFF" sensor for the selective detection of pyrophosphate in a 70% aqueous buffer (10 mM HEPES, pH = 7.4) acetonitrile solvent with a nanomolar detection limit (45.37 × 10-9 M).

Metallomics investigations on potential binding partners of methylmercury in tuna fish muscle tissue using complementary mass spectrometric techniques.

PubMed

Kutscher, Daniel J; Sanz-Medel, Alfredo; Bettmer, Jörg

2012-08-01

In this study, the binding behaviour of methylmercury (MeHg(+)) towards proteins is investigated. Free sulfhydryl groups in cysteine residues are known to be the most likely binding partners, due to the high affinity of mercury to sulphur. However, detailed knowledge about discrete binding sites in living organisms has been so far scarce. A metallomics approach using different methods like size-exclusion chromatography (SEC) and liquid chromatography (LC) coupled to inductively coupled plasma-mass spectrometry (ICP-MS) as well as complementary mass spectrometric techniques (electrospray ionisation-tandem mass spectrometry, ESI-MS/MS) are combined to sequence and identify possible target proteins or peptides after enzymatic digestion. Potential targets for MeHg(+) in tuna fish muscle tissue are investigated using the certified reference material CRM464 as a model tissue. Different extraction procedures appropriate for the extraction of proteins are evaluated for their efficiency using isotope dilution analysis for the determination of total Hg in the extracts. Due to the high chemical stability of the mercury-sulphur bond, the bioconjugate can be quantitatively extracted with a combination of tris(hydroxymethyl)aminomethane (TRIS) and sodium dodecyl sulphate (SDS). Using different separation techniques such as SEC and SDS-polyacrylamide gel electrophoresis (SDS-PAGE) it can be shown that major binding occurs to a high-molecular weight protein (M(w) > 200 kDa). A potential target protein, skeletal muscle myosin heavy chain, could be identified after tryptic digestion and capillary LC-ESI-MS/MS.

Synthesis, structurale elucidation and antioxidant study of Ortho-substituted N,N’-bis(benzamidothiocarbonyl)hydrazine derivatives

NASA Astrophysics Data System (ADS)

Firdausiah, Syadza; Hasbullah, S. A.; Yamin, B. M.

2018-03-01

Some bis(thiourea) compounds have been reported to posses excellent performance in pharmaceutical and environmental fields because of their ability to form chelating complexes with various anions and metal ions. Structurally for carbonyl thiourea derivatives, to become a chelating agent, it must adopt cis-configuration. In the present study, four new bis(thiourea) derivatives namely N,N’-bis(o-fluorobenzamidothiocarbonyl)hydrazine (1), N,N’- bis(o-chloro-benzamidothiocarbonyl)hydrazine (2), N,N’-bis(o-nitrobenzamidothiocarbonyl)-hydrazine (3), and N,N’-bis(o-methylbenzamidothiocarbonyl)hydrazine (4) were successfully synthesized and characterized by CHNS microelemental analysis, FTIR, UV-Vis, and 1H and 13C NMR spectroscopy. However chemical crystallography study showed that both thiourea moieties in compound (2) and (3) adopt trans geometry. Therefore they are potential monodentate ligand with two active moieties. DPPH radical scavenging experiment showed that compound (1), (2), and (4) exhibited higher antioxidant activity than ascorbic acid (Vitamin C).

Mechanism of Amido-Thiourea Catalyzed Enantioselective Imine Hydrocyanation: Transition State Stabilization via Multiple Non-Covalent Interactions

PubMed Central

Zuend, Stephan J.

2009-01-01

An experimental and computational investigation of amido-thiourea promoted imine hydrocyanation has revealed a new and unexpected mechanism of catalysis. Rather than direct activation of the imine by the thiourea, as had been proposed previously in related systems, the data are consistent with a mechanism involving catalyst-promoted proton transfer from hydrogen isocyanide to imine to generate diastereomeric iminium/cyanide ion pairs that are bound to catalyst through multiple non-covalent interactions; these ion pairs collapse to form the enantiomeric α-aminonitrile products. This mechanistic proposal is supported by the observation of a statistically significant correlation between experimental and calculated enantioselectivities induced by eight different catalysts (P ≪ 0.01). The computed models reveal a basis for enantioselectivity that involves multiple stabilizing and destabilizing interactions between substrate and catalyst, including thiourea-cyanide and amide-iminium interactions. PMID:19778044

Ethylene thiourea (ETU)

Integrated Risk Information System (IRIS)

Ethylene thiourea ( ETU ) ; CASRN 96 - 45 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarci

Bulk growth of undoped and Nd3+ doped zinc thiourea chloride (ZTC) monocrystal: Exploring the remarkably enhanced structural, optical, electrical and mechanical performance of Nd3+ doped ZTC crystal for NLO device applications

NASA Astrophysics Data System (ADS)

Anis, Mohd; Muley, Gajanan. G.

2017-05-01

In current scenario good quality crystals are demanded for NLO device application hence present communication is aimed to grow bulk crystal and investigate the doping effect of rare earth element Nd3+ on structural, linear-nonlinear optical, luminescence, mechanical and dielectric properties of zinc thiourea chloride (ZTC) crystal. The ZTC crystal of dimension 21×10×8 mm3 and the Nd3+ doped ZTC crystal of dimension 27×17×5 mm3 have been grown from aqueous solution by slow evaporation technique. The elemental analysis of Nd3+ doped ZTC single crystal has been performed by means of energy dispersive spectroscopic technique. The powder X-ray diffraction technique has been employed to confirm the crystalline phase and identify the effect of Nd3+ doping on structural dimensions of ZTC crystal. The grown crystals have been characterized by UV-Vis-NIR study in the range of 190-1100 nm to ascertain the enhancement in optical transparency of ZTC crystal facilitated by dopant Nd3+. The recorded transmittance data has been utilized to investigate the vital optical constants of grown crystals. The second order nonlinear optical behavior of grown crystals has been evaluated by means of Kurtz-Perry test and the second harmonic generation efficiency of Nd3+ doped ZTC crystal is found to be 1.24 times higher than ZTC crystal. The luminescence analysis has been performed to examine the electronic purity and the color centered photoluminescence emission nature of pure and Nd3+ doped ZTC crystals. The influence of Nd3+ ion on mechanical behavior of ZTC crystal has been investigated by means of microhardness studies. The nature of dielectric constant and dielectric loss of pure and Nd3+ doped ZTC crystal has been examined in the range of 40-100 °C under dielectric study. The Z-scan technique has been employed using the He-Ne laser to investigate the third order nonlinear optical (TONLO) nature of Nd3+ doped ZTC single crystal. The magnitude of TONLO susceptibility, absorption coefficient and refraction has been determined using the Z-scan transmittance data.

Evaluation of long-term corrosion durability and self-healing ability of scratched coating systems on carbon steel in a marine environment

NASA Astrophysics Data System (ADS)

Zhao, Xia; Chen, Changwei; Xu, Weichen; Zhu, Qingjun; Ge, Chengyue; Hou, Baorong

2017-09-01

Defects in protective-coating systems on steel surfaces are inevitable in practical engineering applications. A composite coating system, including a primer, middle coat and topcoat, were used to protect carbon steel from corrosion in a marine environment. Two environmental additives, glass fibers and thiourea, were applied in the middle coat to modify the coating system. The long-term corrosion durability and self-healing ability of the scratched coating system were evaluated by multiple methods. Results of the electrochemical technologies indicated that the coating system that contained 0.5 wt.% fibers and 0.5 wt.% thiourea presented good corrosion protection and self-healing for carbon steel when immersed in 3.5% NaCl for 120 d. Evolution of localized corrosion factors with time, as obtained from the current distribution showed that fibers combined with thiourea could inhibit the occurrence of local corrosion in scratched coating systems and retarded the corrosion development significantly. Surface characterization suggested that adequate thiourea could be absorbed uniformly on fibers for a long time to play an important role in protecting the carbon steel. Finally, schematic models were established to demonstrate the action of fibers and thiourea on the exposed surface of the carbon steel and the scratched coating system in the entire deterioration process.

Effect of Jahn-Teller ion in zinc sodium sulphate hexahydrate: a case of low hyperfine coupling constant for Cu(II) ion

NASA Astrophysics Data System (ADS)

Naidu, K. C.; Shiyamala, C.; Mithira, S.; Natarajan, B.; Venkatesan, R.; Rao, P. S.

2005-06-01

Single crystal electron paramagnetic resonance (EPR) studies of Cu(II) doped zinc sodium sulphate hexahydrate are carried out from room temperature (RT) to 123 K. The RT spectra show unresolved hyperfine lines and hence angular variation studies are also carried out at 123 K to obtain spin Hamiltonian parameters. The spin Hamiltonian parameters calculated from the 123 K spectra are: g(11)=2.039, g(22)=2.232, g(33)=2.394, A(11)=5.64 mT, A(22)=4.20 mT, and A(33)=7.94 mT. The g-matrix values at RT and 123 K have matched fairly well with each other. The low hyperfine value (A(33)), obtained at 123 K, has been explained by considering considerable admixture of d(x 2-y 2) ground state with d(z 2) excited state and the delocalization of the unpaired spin density onto the ligands. The admixture coefficients of ground state wave function are: a=0.346, b=0.935, c=0.055, d=0.040, e=-0.040, where a and b correspond to admixture coefficients for d(z 2) and d(x 2-y 2), respectively. Angular variation of Cu(II) resonances in the three orthogonal axes shows that the impurity has entered a substitutional site in the host lattice in place of Zn(II). Bonding parameters, kappa=0.295, P=245.4x10(-4), alpha(2)=0.709, alpha=0.8421 and alpha'=0.6034, have also been calculated to fully characterize the EPR.

Using the Slug Mucosal Irritation Assay to Investigate the Tolerability of Tablet Excipients on Human Skin in the Context of the Use of a Nipple Shield Delivery System.

PubMed

Kendall, Richard; Lenoir, Joke; Gerrard, Stephen; Scheuerle, Rebekah L; Slater, Nigel K H; Tuleu, Catherine

2017-04-01

Neonates are particularly challenging to treat. A novel patented drug delivery device containing a rapidly disintegrating tablet held within a modified nipple shield (NSDS) was designed to deliver medication to infants during breastfeeding. However concerns exist around dermatological nipple tolerability with no pharmaceutical safety assessment guidance to study local tissue tolerance of the nipple and the areola. This is the first Slug Mucosal Irritation (SMI) study to evaluate irritancy potential of GRAS excipients commonly used to manufacture rapidly disintegrating immediate release solid oral dosage form METHODS: Zinc sulphate selected as the antidiarrheal model drug that reduces infant mortality, was blended with functional excipients at traditional levels [microcrystalline cellulose, sodium starch glycolate, croscarmellose sodium, magnesium stearate]. Slugs were exposed to blends slurried in human breast milk to assess their stinging, itching or burning potential, using objective values such as mucus production to categorize irritation potency RESULTS: Presently an in vivo assay, previously validated for prediction of ocular and nasal irritation, was used as an alternative to vertebrate models to anticipate the potential maternal dermatological tolerability issues to NSDS tablet components. The excipients did not elicit irritancy. However, mild irritancy was observed when zinc sulphate was present in blends. These promising good tolerability results support the continued investigation of these excipients within NSDS rapidly disintegrating tablet formulations. Topical local tolerance effects being almost entirely limited to irritation, the slug assay potentially adds to the existing preformulation toolbox, and may sit in between the in vitro and existing in vivo assays.

DETERMINATION OF CARBAMATE, UREA, AND THIOUREA PESTICIDES AND HERBICIDES IN WATER

EPA Science Inventory

Microbe liquid chromatography and positive ion electrospray mass spectrometry are applied to the determination of 16 carbamate, urea, and thiourea pesticides and herbicides in water. The electrospray mass spectra of the analytes were measured and are discussed and mobile phase m...

21 CFR 189.190 - Thiourea.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Thiourea. 189.190 Section 189.190 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES PROHIBITED FROM USE IN HUMAN FOOD Substances Generally Prohibited From...

21 CFR 189.190 - Thiourea.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Thiourea. 189.190 Section 189.190 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES PROHIBITED FROM USE IN HUMAN FOOD Substances Generally Prohibited From...

21 CFR 189.190 - Thiourea.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Thiourea. 189.190 Section 189.190 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES PROHIBITED FROM USE IN HUMAN FOOD Substances Generally Prohibited From...

Thioureas as ligands in the pd-catalyzed intramolecular Pauson-Khand reaction.

PubMed

Tang, Yefeng; Deng, Lujiang; Zhang, Yangdong; Dong, Guangbin; Chen, Jiahua; Yang, Zhen

2005-04-14

[reaction: see text] The thiourea-Pd complex was established as a novel type of catalyst in the PKR of allylpropargylamine, and the demonstrated chemistry may prove to be valuable for developing thiuorea as a ligand for the Pd-catalyzed Pauson-Khand reaction.

2-Methylacrylamide as a bioisoster of thiourea group for 1,3-dibenzylthioureido TRPV1 receptor antagonists.

PubMed

Park, Seol Rin; Kim, Juhyun; Lee, Sun Young; Park, Young-Ho; Kim, Hee-Doo

2018-06-15

In order to replace thiourea group with the more drug-like moiety for 1,3-dibenzylthioureas having TRPV1 antagonist activity, we introduced a set of functional groups between the two aromatic rings based on bioisosteric replacement. The synthesized bioisosteres of 1,3-dibenzylthioureas were tested for their antagonist activities on TRPV1 by 45 Ca 2+ -influx assay using neonatal rat cultured spinal sensory neurons. Among the tested 14 kinds of bioisosters, 2-methylacrylamide group was the best candidate to replace thiourea group. Compound 7c, 2-methylacrylamide analog of ATC-120, showed as potent as ATC-120 in its antagonist activity. In addition, 2-methylacrylamide analog 7e having vinyl moiety showed the most potent activity with 0.022 μM of IC 50 value, indicating that thiourea group of 1,3-dibenzylthioureas could be replaced to 2-methylacrylamide without loss of their potencies. Copyright © 2018 Elsevier Ltd. All rights reserved.

Thiourea leaching gold and silver from the printed circuit boards of waste mobile phones.

PubMed

Jing-ying, Li; Xiu-li, Xu; Wen-quan, Liu

2012-06-01

The present communication deals with the leaching of gold and silver from the printed circuit boards (PCBs) of waste mobile phones using an effective and less hazardous system, i.e., a thiourea leaching process as an alternative to the conventional and toxic cyanide leaching of gold. The influence of particle size, thiourea and Fe(3+) concentrations and temperature on the leaching of gold and silver from waste mobile phones was investigated. Gold extraction was found to be enhanced in a PCBs particle size of 100 mesh with the solutions containing 24 g/L thiourea and Fe(3+) concentration of 0.6% under the room temperature. In this case, about 90% of gold and 50% of silver were leached by the reaction of 2h. The obtained data will be useful for the development of processes for the recycling of gold and silver from the PCBs of waste mobile phones. Copyright © 2012 Elsevier Ltd. All rights reserved.

Zinc supplements for treating thalassaemia and sickle cell disease.

PubMed

Swe, Kye Mon Min; Abas, Adinegara B L; Bhardwaj, Amit; Barua, Ankur; Nair, N S

2013-06-28

Haemoglobinopathies, inherited disorders of haemoglobin synthesis (thalassaemia) or structure (sickle cell disease), are responsible for significant morbidity and mortality throughout the world. The WHO estimates that, globally, 5% of adults are carriers of a haemoglobin condition, 2.9% are carriers of thalassaemia and 2.3% are carriers of sickle cell disease. Carriers are found worldwide as a result of migration of various ethnic groups to different regions of the world. Zinc is an easily available supplement and intervention programs have been carried out to prevent deficiency in people with thalassaemia or sickle cell anaemia. It is important to evaluate the role of zinc supplementation in the treatment of thalassaemia and sickle cell anaemia to reduce deaths due to complications. To assess the effect of zinc supplementation in the treatment of thalassaemia and sickle cell disease. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.Date of most recent search: 01 February 2013. Randomised, placebo-controlled trials of zinc supplements for treating thalassaemia or sickle cell disease administered at least once a week for at least a month. Two review authors assessed the eligibility and risk of bias of the included trials, extracted and analysed data and wrote the review. We summarised results using risk ratios or rate ratios for dichotomous data and mean differences for continuous data. We combined trial results where appropriate. We identified nine trials for inclusion with all nine contributing outcome data. Two trials reported on people with thalassaemia (n = 152) and seven on sickle cell anaemia (n = 307).In people with thalassaemia, in one trial, the serum zinc level value showed no difference between the zinc supplemented group and the control group, mean difference 47.40 (95% confidence interval -12.95 to 107.99). Regarding anthropometry, in one trial, height velocity was significantly increased in patients who received zinc supplementation for one to seven years duration, mean difference 3.37 (95% confidence interval 2.36 to 4.38) (total number of participants = 26). In one trial, however, there was no difference in body mass index between treatment groups.Zinc acetate supplementation for three months (in one trial) and one year (in two trials) (total number of participants = 71) was noted to increase the serum zinc level significantly in patients with sickle cell anaemia, mean difference 14.90 (95% confidence interval 6.94 to 22.86) and 20.25 (95% confidence interval 11.73 to 28.77) respectively. There was no significant difference in haemoglobin level between intervention and control groups, at either three months (one trial) or one year (one trial), mean difference 0.06 (95% confidence interval -0.84 to 0.96) and mean difference -0.07 (95% confidence interval -1.40 to 1.26) respectively. Regarding anthropometry, one trial showed no significant changes in body mass index or weight after one year of zinc acetate supplementation. In patients with sickle cell disease, the total number of sickle cell crises at one year were significantly decreased in the zinc sulphate supplemented group as compared to controls, mean difference -2.83 (95% confidence interval -3.51 to -2.15) (total participants 130), but not in zinc acetate group, mean difference 1.54 (95% confidence interval -2.01 to 5.09) (total participants 22). In one trial at three months and another at one year, the total number of clinical infections were significantly decreased in the zinc supplemented group as compared to controls, mean difference 0.05 (95% confidence interval 0.01 - 0.43) (total number of participants = 36), and mean difference -7.64 (95% confidence interval -10.89 to -4.39) (total number of participants = 21) respectively. According to the results, there is no evidence from randomised controlled trials to indicate any benefit of zinc supplementation with regards to serum zinc level in patients with thalassaemia. However, height velocity was noted to increase among those who received this intervention.There is mixed evidence on the benefit of using zinc supplementation in people with sickle cell disease. For instance, there is evidence that zinc supplementation for one year increased the serum zinc levels in patients with sickle cell disease. However, though serum zinc level was raised in patients receiving zinc supplementation, haemoglobin level and anthropometry measurements were not significantly different between groups. Evidence of benefit is seen with the reduction in the number of sickle cell crises among sickle cell patients who received one year of zinc sulphate supplementation and with the reduction in the total number of clinical infections among sickle cell patients who received zinc supplementation for both three months and for one year.The conclusion is based on the data from a small group of trials,which were generally of good quality, with a low risk of bias. The authors recommend that more trials on zinc supplementation in thalassaemia and sickle cell disease be conducted given that the literature has shown the benefits of zinc in these types of diseases.

Zinc complex chemistry of N,N,O ligands providing a hydrophobic cavity.

PubMed

Gross, Florian; Vahrenkamp, Heinrich

2005-05-02

Three new highly substituted bis(2-picolyl)(2-hydroxybenzyl)amine ligands were synthesized, and their biomimetic zinc complex chemistry was explored. They have tert-butyl substituents at the 3-and 5-positions of their phenyl rings, and they bear one phenyl group (HL2), two methyl groups (HL3), or two phenyl groups (HL4) at the 6-positions of their pyridyl rings. Their reactions with hydrated zinc perchlorate yield three distinctively different complex types. L2 forms a trigonal-bipyramidal aqua complex, and L3, a square-pyramidal aqua complex. The substituents on L4 leave no room for a water ligand, and the resulting zinc complex is trigonal-monopyramidal with a vacant coordination site. The water ligands on the L2Zn and L3Zn units can be replaced by anionic halide, thiocyanate, p-nitrophenolate, benzoate, and organophosphate as well as uncharged pyridine ligands. The L4Zn unit forms labile halide, p-nitrophenolate, and pyridine complexes. Triethylamine converts the aqua complexes to the labile hydroxides L2Zn-OH and L3Zn-OH, and in polar media [L3Zn-OH2]+ seems to be in equilibrium with L3Zn-OH. The hydroxides, but not the water complexes, effect the hydrolytic cleavage of tris(p-nitrophenyl) phosphate to bis(p-nitrophenyl) phosphate. The kinetic investigation of the cleavage reactions has shown them to be second-order reactions, thereby supporting the proposed four-center mechanism.

Recent Advances in Dynamic Kinetic Resolution by Chiral Bifunctional (Thio)urea- and Squaramide-Based Organocatalysts.

PubMed

Li, Pan; Hu, Xinquan; Dong, Xiu-Qin; Zhang, Xumu

2016-10-14

The organocatalysis-based dynamic kinetic resolution (DKR) process has proved to be a powerful strategy for the construction of chiral compounds. In this feature review, we summarized recent progress on the DKR process, which was promoted by chiral bifunctional (thio)urea and squaramide catalysis via hydrogen-bonding interactions between substrates and catalysts. A wide range of asymmetric reactions involving DKR, such as asymmetric alcoholysis of azlactones, asymmetric Michael-Michael cascade reaction, and enantioselective selenocyclization, are reviewed and demonstrate the efficiency of this strategy. The (thio)urea and squaramide catalysts with dual activation would be efficient for more unmet challenges in dynamic kinetic resolution.

Binding of urea and thiourea with a barbiturate derivative: experimental and theoretical approach.

PubMed

Dixit, Namrata; Shukla, P K; Mishra, P C; Mishra, Lallan; Roesky, Herbert W

2010-01-14

A barbiturate derivative [1,5-dihydro-5-[5-pyrimidine-2,4(1H,3H)-dionyl]-2H-chromeno[2,3-d] pyrimidine-2,4(3H)-dione)] (L1) possesses functionalities complementary to amide and thioamide. Hence its binding with urea and thiourea, is monitored using UV-vis and fluorescence titrations as well as isothermal titration calorimetry (ITC) study. Theoretical studies on hydrogen-bonded complexes of L1-urea and L1-thiourea in the gas phase, aqueous, and DMSO medium are carried out using density functional theory (DFT) at the B3LYP/6-31G** level. The theoretical calculations support the experimental results.

Comparative XAFS studies of some Cobalt complexes of (3-N- phenyl -thiourea-pentanone-2)

NASA Astrophysics Data System (ADS)

soni, Namrata; Parsai, Neetu; Mishra, Ashutosh

2016-10-01

XAFS spectroscopy is a useful method for determining the local structure around a specific atom in disordered systems. XAFS study of some cobalt complexes of (3-N-phenyle- thiourea-pentanon-2) is carried out using the latest XAFS analysis software Demeter with Strawberry Perl. The same study is also carried out theoretically using Mathcad software. It is found that the thiourea has significant influence in the spectra and the results obtained experimentally and theoretically are in agreement. Fourier transform of the experimental and theoretically generated XAFS have been taken to obtain first shell radial distance. The values so obtained are in agreement with each other.

21 CFR 189.190 - Thiourea.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Thiourea. 189.190 Section 189.190 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES PROHIBITED FROM USE IN HUMAN FOOD Substances Generally Prohibited From Direct Addition or Use as Human Food § 189...

Effects of zinc supplementation on obesity: study protocol for a randomized controlled clinical trial.

PubMed

Rathnayake, Kumari M; Silva, Kdrr; Jayawardena, Ranil

2016-11-04

The prevalence of obesity is escalating alarmingly worldwide, and it is now becoming a rapidly growing epidemic in developing countries. Recent studies have reported that zinc has been implicated in altered lipid markers, insulin resistance and some obesity markers. There is a lack of evidence on zinc as a potential therapeutic agent to reduce weight and improve metabolic parameters in obese adults. The present study is designed to evaluate the effects of zinc supplementation on obese adults in Sri Lanka. Furthermore, we aim to evaluate the effects of zinc supplementation on metabolic parameters in this population. This study will be conducted as a randomized, double-blind, placebo-controlled clinical trial for a period of 3 months at the clinical laboratory, Department of Applied Nutrition, Wayamba University of Sri Lanka to assess the efficacy of daily zinc 20 mg supplementation in obese subjects. There will be a total of 80 subjects, aged between 18-60 years, of both genders, who are obese (body mass index (BMI) ≥25). Subjects will be stratified according to age, gender and BMI and randomly assigned into the test and placebo groups in a 1:1 ratio. The treatment drug is a capsule containing elemental zinc 20 mg as the active ingredient (as zinc sulphate). The placebo capsule will contain lactose monohydrate. The subjects will receive either zinc capsules or placebo daily for 3 months. The study treatments will be double blinded to both investigator and subject. The visits and the evaluations will be as follows: screening (visit 0), baseline (visit 1) and 3 month (visit 2). The primary outcome will be weight reduction among the obese subjects. Secondary outcome measures include glycaemic status (fasting blood glucose), lipid parameters (total cholesterol, triglyceride levels, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol) and blood pressure. The trial protocol will aim to establish the effects of zinc supplementation on weight reduction and metabolic risk parameters among obese subjects. Sri Lanka Clinical Trials Registry: SLCTR/2014/020 . Registered on 18 September 2014.

A multi-channel photometric detector for multi-component analysis in flow injection analysis

PubMed Central

Tan, Aimin; Huang, Jialin; Geng, Liudi; Xu, Jinhua; Zhao, Xinna

1994-01-01

The detector, a multi-channel photometric detector, described in this paper was developed using multi-wavelength LEDs (light emitting diode) and phototransistors for absorbance measurement controlled by an Intel 8031 8-bit single chip microcomputer. Up to four flow cells can be attached to the detector. The LEDs and phototransistors are both inexpensive, and reliable. The results given by the detector for simultaneous determination of trace amounts of cobalt and cadmium in zinc sulphate electrolyte are reported. Because of the newly developed detector, this approach employs much less hardware apparatus than by employing conventional photometric detectors. PMID:18924688

A multi-channel photometric detector for multi-component analysis in flow injection analysis.

PubMed

Tan, A; Huang, J; Geng, L; Xu, J; Zhao, X

1994-01-01

The detector, a multi-channel photometric detector, described in this paper was developed using multi-wavelength LEDs (light emitting diode) and phototransistors for absorbance measurement controlled by an Intel 8031 8-bit single chip microcomputer. Up to four flow cells can be attached to the detector. The LEDs and phototransistors are both inexpensive, and reliable. The results given by the detector for simultaneous determination of trace amounts of cobalt and cadmium in zinc sulphate electrolyte are reported. Because of the newly developed detector, this approach employs much less hardware apparatus than by employing conventional photometric detectors.

Bringing forward the new generation of alkoxy-thiourea as potential treatment for Acanthamoeba keratitis

NASA Astrophysics Data System (ADS)

Khairul, Wan M.; Goh, Yit-Peng; Daud, Adibah Izzati; Nakisah, M. A.

2017-02-01

Alkoxy substituted thiourea derivatives with general formula of A-ArC(O)NHC(S)NHAr-D which A represents the methoxy group and D denotes -OCnH2n+1 have been successfully synthesised and characterized. In turn, all the synthesised molecules were assayed for anti-amoebic activities towards Acanthamoeba sp to examine the cytotoxicity effect at their IC50 and membrane permeability. As predicted, the findings showed that the synthesised molecules owing promising anti-amoebic activity towards Acanthamoeba sp. To support, the Acridine-orange/Propidium iodide (AOPI) staining result under fluorescence microscopy revealed the treated amoeba cells by these alkoxy thiourea derivatives exhibited loss in their membrane permeability.

Clinical study of the effectiveness of the "water of the 3 sulfates" on balanitis and balanoposthitis.

PubMed

Gonzalvo, V; Polo, A; Serrallach, F; Gutiérrez, A; Peyri, E

2015-03-01

Despite scientific literature mentions the application of "water of the 3 sulfates" (copper sulphate, zinc sulphate and alum) as a treatment for acute balanitis and balanoposthitis, no clinical trials evaluating its efficacy have been found. In our study we evaluate the efficacy of this solution in acute balanitis and balanoposthitis. A double-blind randomized study was designed to compare the efficacy of "water of the 3 sulfates" (intervention) with saline solution (control) in 50 patients (30 patients and 20 patients, respectively) who suffer from acute balanitis or balanoposthitis. Exudate, erythema, oedema, burning, and itching were the clinical parameters assessed. for all clinical parameters assessed, the outcomes obtained with "water of the 3 sulfates" are higher than control, although significant differences only have been found for exudate. in our study, the "water of the 3 sulfates" is significantly more effective than saline solution for removing exudates in acute balanitis and balanoposthitis. Tolerability was excellent in both treatments. Copyright © 2014 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Determination of heavy metals in mussel and oyster samples with tris (2,2‧-bipyridyl) ruthenium (II)/graphene/Nafion® modified glassy carbon electrodes

NASA Astrophysics Data System (ADS)

Palisoc, Shirley T.; Uy, Donald Jans S.; Natividad, Michelle T.; Lopez, Toni Beth G.

2017-11-01

Tris (2,2‧-bipyridyl)ruthenium(II)/graphene/Nafion® modified glassy carbon electrodes (GCEs) were fabricated using the drop coating method. The modified electrode was used as the working electrode in differential pulse voltammetry (DPV) for the determination of lead, cadmium, and copper in mussel and oyster samples. The concentration of Tris (2,2‧-bipyridyl) ruthenium (II) and graphene were varied while those of Nafion®, methanol, and ethanol were held constant in the coating solution. The morphology and elemental composition of the fabricated electrodes were analyzed by scanning electron microscopy and energy-dispersive x-ray spectroscopy. Cyclic voltammetry (CV) was done to investigate the reversibility and stability of the modified electrodes. The modified electrode with the best figures of merit was utilized for the detection of copper (Cu2+), lead (Pb2+) and cadmium (Cd2+) via DPV. This was the electrode modified with 4 mg [Ru (bpy)3]2+ and 3 mg graphene. The anodic current and metal concentration showed linear relationship in the range of 48 ppb-745 ppb for Pb2+, 49 ppb-613 ppb for Cd2+, and 28 ppb-472 ppb for Cu2+. The limits of detection for lead, cadmium, and copper were 48 ppb, 49 ppb, and 28 ppb, respectively. Results from atomic absorption spectrometry (AAS) were compared with those measured with DPV. Lead, cadmium, and copper were in mussels, oysters, and sea water. In addition, DPV was able to detect other metals such as zinc, iron, tin and mercury in sea water samples and some samples of oysters.

Synthesis, characterization and antibacterial studies of 2-chloro-5-fluoro-N-[dibenzyl carbamothioyl] benzamide thiourea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sapari, Suhaila; Yamin, Bohari M.; Hasbullah, Aishah

Synthesis, characterization and antibacterial studies of 2-chloro-5-fluoro-N-[dibenzyl carbamothioyl] benzamide thiourea has been reported. The compound characterized by using elementary analysis CHNS, IR, {sup 1}H NMR and {sup 13}C NMR spectroscopies. The compounds have been screened for their antibacterial studies.

Development and validation of an MEKC method for determination of nitrogen-containing drugs in pharmaceutical preparations.

PubMed

Buiarelli, Francesca; Coccioli, Franco; Jasionowska, Renata; Terracciano, Alessandro

2008-09-01

A fast and accurate micellar electrokinetic capillary chromatography method was developed for quality control of pharmaceutical preparations containing cold remedies as acetaminophen, salicylamide, caffeine, phenylephrine, pseudoephedrine, norephedrine and chlorpheniramine. The method optimization was realized on a Beckman P/ACE System MDQ instrument. The baseline separation of seven analytes was performed in an uncoated fused silica capillary internal diameter (ID)=50 microm using tris-borate (20 mM, pH=8.5) containing sodium dodecyl sulphate 30 mM BGE. On line-UV detection at 214 nm was performed and the applied voltage was 10 kV. The operating temperature was 25 degrees C. After experimental conditions optimization, the proposed method was validated. The evaluated parameters were: precision of migration time and of corrected peak area ratio, linearity range, limit of detection, limit of quantification, accuracy (recovery), ruggedness and applicability. The method was then successfully applied for the analysis of three pharmaceutical preparations containing some of the analytes listed before.

Se metallomics during lactic fermentation of Se-enriched yogurt.

PubMed

Palomo, María; Gutiérrez, Ana M; Pérez-Conde, M Concepción; Cámara, Carmen; Madrid, Yolanda

2014-12-01

Selenium biotransformation by lactic acid bacteria during the preparation of Se-enriched yogurt was evaluated. The study focused on the distribution of selenium in the aqueous soluble protein fraction and the detection of selenoamino acids. Screening of selenium in Tris-buffer-urea soluble fraction was carried out by sodium dodecyl sulphate polyacrylamide gel electrophoresis after pre-fractionating with asymmetric field flow fractionation using inductively coupled plasma-mass spectrometry as the detector. Selenium-containing fractions were identified by peptide mapping using nano LC-ESI/LTQMS. Proteins such as thioredoxin, glutaredoxin, albumin, β-lactoglobulin, and lactoperoxidase were identified in the selenium-containing fraction. All these proteins were detected in both the control and the selenium-enriched yogurt except chaperones, which were only detected in the control samples. Chaperones are heat-shock proteins expressed in response to elevated temperature or other cellular stresses. Selenium may have an effect on chaperones expression in Lactobacillus. For the amino acids analysis, selenocysteine was the primary seleno-containing species. Copyright © 2014 Elsevier Ltd. All rights reserved.

A turn-on fluorescence chemosensor based on a tripodal amine [tris(pyrrolyl-α-methyl)amine]-rhodamine conjugate for the selective detection of zinc ions.

PubMed

Balamurugan, Rathinam; Chang, Wen-I; Zhang, Yandison; Fitriyani, Sri; Liu, Jui-Hsiang

2016-09-21

A novel tetradendate ligand derived from a tris(pyrrolyl-α-methyl)amine (H3tpa) and rhodamine-based conjugate (PR) has been designed for use as a sensor, synthesized and characterized spectroscopically. PR {(tris(5-rhodamineiminopyrrol-2-ylmethyl)amine)} serves as a selective colorimetric as well as a fluorescent chemosensor for Zn(2+) in acetonitrile/water (1 : 1, v/v). In the presence of Zn(2+), PR exhibited obvious absorption (558 nm) and emission (577 nm) peaks whose intensity increased along with increasing Zn(2+) concentrations. Titration experiments revealed that a large excess of Zn(2+) was required to saturate the absorption (λmax) and emission intensities. Upon the addition of 1000 equivalents of Zn(2+), the fluorescence intensity of the PR underwent an ∼500-fold increase (Φf = 0.34) with the emission maximum at 580 nm. These kinetics studies demonstrated that the absorption and emission changes were proportional to the Zn(2+) concentration. The color of the solution changed from colorless to a dark pink color. The fluorescence of the PR-Zn(2+) complex can be reversibly restored by using ammonium water or by heating. Competitive ion tests revealed that the intensity of PR-Zn(2+) was not suppressed by excess amounts of other metal ions. The counter anions did not exert obvious influences on the absorption and emission profiles. (1)H-NMR and FT-IR spectroscopic investigations of PR and PR-Zn(2+) revealed that the pyrrole motifs, -C[double bond, length as m-dash]N- groups and spirolactam of rhodamine B are capable of coordinating cation guest species. Because each arm of the tripodal ligand tautomerizes independently, only moderate fluorescence enhancement could be seen until all three -C[double bond, length as m-dash]N- groups were coordinated by zinc, which may be due to the spirolactam ring opening mechanism of the rhodamine unit. Once all three -C[double bond, length as m-dash]N- groups were locked by coordinating with excess of Zn(2+), the isomerization was arrested, and PR exhibited highly enhanced fluorescence. In addition, energy optimized structures of PR were found to be cage-like by Gaussian 09, further supporting that it can access a large excess of Zn(2+). Intriguingly, imaging of HeLa cells by using a confocal microscope revealed that this PR probe could be used for biological applications.

Synthesis and characterization of zinc-molybdenum oxide photocatalysts using an electrochemical-thermal process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goveas, J. J., E-mail: jenicegoveas@gmail.com; Gonsalves, R. A.; Rao, P.

2016-05-23

Dyes act as major pollutants in water and can be degraded by photocatalysis. This paper establishes the role of electrochemically generated nanostructures of Zinc-Molybdenum oxides (ZMO) as photocatalysts by degrading EBT (Eriochrome Black- T) taken as a model pollutant under UV light. A facile, rapid and low cost process to synthesize these nanostructures (ZMO) is presented. Various factors that affect the synthesis and photocatalytic activity of these nanostructures are discussed. The role of calcination temperature and pulverization on the photocatalytic action has also been established. Particles have been synthesized in pure form as well as using surfactants such as cetrimidemore » (cetyl trimethyl ammonium bromide), polyethylene glycol (PEG) and SDS (sodium dodecyl sulphate) to enhance their photocatalytic action. This paper also discusses the characterization of these nanoparticles by powder XRD, SEM, FT-IR and UV-Visible spectroscopy. Decolourisation was achieved to completion under optimum experimental conditions at room temperature ascertaining the application of these nanostructures as effective photocatalysts.« less

Field evidence of cadmium phytoavailability decreased effectively by rape straw and/or red mud with zinc sulphate in a Cd-contaminated calcareous soil.

PubMed

Li, Bo; Yang, Junxing; Wei, Dongpu; Chen, Shibao; Li, Jumei; Ma, Yibing

2014-01-01

To reduce Cd phytoavailability in calcareous soils, the effects of soil amendments of red mud, rape straw, and corn straw in combination with zinc fertilization on Cd extractability and phytoavailability to spinach, tomato, Chinese cabbage and radish were investigated in a calcareous soil with added Cd at 1.5 mg kg-1. The results showed that water soluble and exchangeable Cd in soils was significantly decreased by the amendments themselves from 26% to 70%, which resulted in marked decrease by approximately from 34% to 77% in Cd concentration in vegetables. The amendments plus Zn fertilization further decreased the Cd concentration in vegetables. Also cruciferous rape straw was more effective than gramineous corn straw. In all treatments, rape straw plus red mud combined with Zn fertilization was most effective in decreasing Cd phytoavailability in soils, and it is potential to be an efficient and cost-effective measure to ensure food safety for vegetable production in mildly Cd-contaminated calcareous soils.

Efficient synthesis of optically active 4-nitro-cyclohexanones via bifunctional thiourea-base catalyzed double-Michael addition of nitromethane to dienones.

PubMed

Wu, Bin; Liu, Guo-Gui; Li, Mei-Qiu; Zhang, Yong; Zhang, Shao-Yun; Qiu, Jun-Ru; Xu, Xiao-Ping; Ji, Shun-Jun; Wang, Xing-Wang

2011-04-07

Thiourea-modified cinchona alkaloids as bifunctional catalysts and a base could catalyze a stepwise [5+1] cyclization of divinyl ketones with nitromethane via double Michael additions, furnishing optically active 4-nitro-cyclohexanones with good yields, excellent diastereoselectivities (>20 : 1) and high enantiomeric ratios (up to 97 : 3).

Effects of biodegradation and mechanical activation on gold recovery by thiourea leaching

NASA Astrophysics Data System (ADS)

Kušnierová, Mária; Šepelák, Vladimír; Briančin, Jaroslav

1993-12-01

The work reported here shows the positive influence of the biodegradation of the crystal lattice of sulfides on the thiourea leaching of gold from an arsenopyrite-pyrite concentrate. Physical processing of the original as well as of the biologically processed concentrate favorably influenced gold recovery. Mechanical activation appears to be unimportant for gold extraction from the investigated concentrate.

Clathrate formation and phase equilibria in the thiourea-bromoform system

NASA Astrophysics Data System (ADS)

Chekhova, G. N.; Shubin, Yu. V.; Pinakov, D. V.; Alferova, N. I.

2008-07-01

Phase equilibria in the thiourea (host)-bromoform (guest) binary system were studied by physicochemical analysis methods over the temperature range 270 455 K. The stoichiometry and stability region were determined for the channel-type compound CHBr3 · 2.40(2)(NH2)2CS; the compound was observed for the first time. When heated, the clathrate incongruently decomposed at 424.0 ± 0.8 K to rhombic thiourea and the guest component. The solubility isotherm of the thiourea-bromoform-acetic acid system was studied to find that the compound was thermodynamically stable at 293 K over the range of guest component concentrations 100 35 wt %. A decrease in its content in an equilibrium mother liquor resulted in the appearance of X-ray diffraction reflections of the initial host α polymorph. Rhombohedral cell parameters were determined (space group R-3 c, a = 15.89(1) Å, c = 12.40(1) Å, V = 2711(6) Å3, d calcd = 2.000 g/cm3, and d expt = 1.98(2) g/cm3). The mode of packing of bromoform molecules was compared with the organization of the guest subsystem in inclusion compounds formed by the substances studied.

Zinc supplementation for improving glucose handling in pre-diabetes: A double blind randomized placebo controlled pilot study.

PubMed

Islam, Md Rafiqul; Attia, John; Ali, Liaquat; McEvoy, Mark; Selim, Shahjada; Sibbritt, David; Akhter, Ayesha; Akter, Shahnaz; Peel, Roseanne; Faruque, Omar; Mona, Tazreen; Lona, Hafiza; Milton, Abul Hasnat

2016-05-01

There are a number of studies showing that zinc supplementation may improve glucose handling in people with established diabetes. We sought to investigate whether this zinc-dependent improvement in glucose handling could potentially be harnessed to prevent the progression of pre-diabetes to diabetes. In this double-blind randomized placebo-controlled trial, we determined participants' fasting blood glucose levels, (FBG) and Homeostasis Model Assessment (HOMA) parameters (beta cell function, insulin sensitivity and insulin resistance) at baseline and after 6 months of zinc supplementation. The Bangladesh Institute of Health Sciences Hospital (BIHS) (Mirpur, Dhaka, Bangladesh) database was used to identify 224 patients with prediabetes, of whom 55 met the inclusion criteria and agreed to participate. The participants were randomized either to the intervention or control group using block randomization. The groups received either 30mg zinc sulphate dispersible tablet or placebo, once daily for six months. After six months, the intervention group significantly improved their FBG concentration compared to the placebo group (5.37±0.20mmol/L vs 5.69±0.26, p<0.001) as well as compared to their own baseline (5.37±0.20mmol/L vs 5.8±0.09, p<0.001). Beta cell function, insulin sensitivity and insulin resistance all showed a statistically significant improvement as well. To our knowledge this is the first trial to show an improvement in glucose handling using HOMA parameters in participants with prediabetes. Larger randomized controlled trials are warranted to confirm these findings and to explore clinical endpoints. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Simple chemical synthesis of novel ZnO nanostructures: Role of counter ions

NASA Astrophysics Data System (ADS)

Pudukudy, Manoj; Yaakob, Zahira

2014-04-01

This article reports the synthesis, characterisation and photocatalytic activity of novel ZnO nanostructures prepared via the thermal decomposition of hydrozincite. Hydrozincites were obtained by the conventional precipitation route using different zinc salts such as acetate, nitrate, chloride and sulphate. The effect of counter ions (CH3COO-, Cl-, NO3-, and SO42-) on the structural, textural, morphological and optical properties was investigated. Various characterisations depicted the active role of counter ions in the properties of ZnO. Hexagonal wurtzite structure of ZnO with fine crystalline size was obvious from the XRD results, irrespective of the counter ions. Electron microscopic images indicated the role of counter ions in the surface and internal morphology of ZnO nanomaterials. Special coral like agglomerated morphology of elongated particles with high porosity was observed for the ZnO prepared from acetate precursor. Spherical, elongated and irregular shaped bigger lumps of ZnO nanoparticles with various novel morphologies were resulted for the sulphate, nitrate and chloride precursors respectively. Highly ordered porous micro disc like morphology was noted for the ZnO samples prepared from the sulphate and nitrate salts. Photoluminescence spectra showed the characteristic blue and green emission bands, depicting the presence of large crystal defects and high oxygen vacancies in the samples. Photocatalytic activity of the as-prepared ZnO catalysts was examined by the degradation of methylene blue under UV light irradiation. Degradation results indicated their substantial activity with respect to the counter ions. ZnO prepared from the acetate precursor showed highest photoactivity due to its high surface area, special morphology and high oxygen vacancies.

Tris(hydroxymethyl)aminomethane photooxidation on titania based photoanodes and its implication for photoelectrochemical biofuel cells

NASA Astrophysics Data System (ADS)

Filipiak, Marcin S.; Zloczewska, Adrianna; Grzeskowiak, Piotr; Lynch, Robert; Jönsson-Niedziolka, Martin

2015-09-01

In many photoelectrochemical biofuel cells tris(hydroxymethyl)aminomethane (TRIS) is used a buffer. We show that TRIS can be readily photooxidised on titania electrodes. Combining a titania nanotube photoanode in a TRIS buffer with an air-breathing enzymatic biocathode we construct a relatively efficient photoelectrochemical biofuel cell using the TRIS buffer as fuel. This shows both the prospect of using air-breathing bio-cathodes in this kind of cells, but more importantly, shows the need for caution when using TRIS as buffer in photoelectrochemical applications.

Contribution of Methyl Substituent on the Conductivity Properties and Behaviour of CMC-Alkoxy Thiourea Polymer Electrolyte

DTIC Science & Technology

2014-12-15

article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan...This study reported the synthetic, characterization and theoretical evaluation of molecular wire candidate bearing alkoxy thiourea derivative... studies . Therefore, this type of A-ArC(O)NHC(S)NHAr-D molecular framework has opened wide possibilities to be applied in many micro-electronic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santos, O. L.; Fonseca, T. L., E-mail: tertius@ufg.br; Sabino, J. R.

We present theoretical results for the dipole moment, linear polarizability, and first hyperpolarizability of the urea and thiourea molecules in solid phase. The in-crystal electric properties were determined by applying a supermolecule approach in combination with an iterative electrostatic scheme, in which the surrounding molecules are represented by point charges. It is found for both urea and thiourea molecules that the influence of the polarization effects is mild for the linear polarizability, but it is marked for the dipole moment and first hyperpolarizability. The replacement of oxygen atoms by sulfur atoms increases, in general, the electric responses. Our second-order Møller–Plessetmore » perturbation theory based iterative scheme predicts for the in-crystal dipole moment of urea and thiourea the values of 7.54 and 9.19 D which are, respectively, increased by 61% and 58%, in comparison with the corresponding isolated values. The result for urea is in agreement with the available experimental result of 6.56 D. In addition, we present an estimate of macroscopic quantities considering explicit unit cells of urea and thiourea crystals including environment polarization effects. These supermolecule calculations take into account partially the exchange and dispersion effects. The results illustrate the role played by the electrostatic interactions on the static second-order nonlinear susceptibility of the urea crystal.« less

The Origin and Coupling Mechanism of the Magnetoelectric Effect in TM Cl 2 -4SC(NH 2 ) 2 ( TM = Ni and Co)

DOE PAGES

Mun, Eundeok; Wilcox, Jason; Manson, Jamie L.; ...

2014-01-01

Most research on multiferroics and magnetoelectric effects to date has focused on inorganic oxides. Molecule-based materials are a relatively new field in which to search for magnetoelectric multiferroics and to explore new coupling mechanisms between electric and magnetic order. We present magnetoelectric behavior in NiCl 2 -4SC(NH 2 ) 2 (DTN) and CoCl 2 -4SC(NH 2 ) 2 (DTC). These compounds form tetragonal structures where the transition metal ion (Ni or Co) is surrounded by four electrically polar thiourea molecules [SC(NH 2 ) 2 ]. By tracking the magnetic and electric properties of these compounds as a function of magneticmore » field, we gain insights into the coupling mechanism by observing that, in DTN, the electric polarization tracks the magnetic ordering, whereas in DTC it does not. For DTN, all electrically polar thiourea molecules tilt in the same direction along the c -axis, breaking spatial-inversion symmetry, whereas, for DTC, two thiourea molecules tilt up and two tilt down with respect to c -axis, perfectly canceling the net electrical polarization. Thus, the magnetoelectric coupling mechanism in DTN is likely a magnetostrictive adjustment of the thiourea molecule orientation in response to magnetic order.« less

Application of a thiourea-containing task-specific ionic liquid for the solid-phase extraction cleanup of lead ions from red lipstick, pine leaves, and water samples.

PubMed

Saljooqi, Asma; Shamspur, Tayebeh; Mohamadi, Maryam; Mostafavi, Ali

2014-07-01

Here, task-specific ionic liquid solid-phase extraction is proposed for the first time. In this approach, a thiourea-functionalized ionic liquid is immobilized on the solid sorbent, multiwalled carbon nanotubes. These modified nanotubes packed into a solid-phase extraction column are used for the selective extraction and preconcentration of ultra-trace amounts of lead(II) from aqueous samples prior to electrothermal atomic absorption spectroscopy determination. The thiourea functional groups act as chelating agents for lead ions retaining them and so, give the selectivity to the sorbent. Elution of the retained ions can be performed using an acidic thiourea solution. The effects of experimental parameters including pH of the aqueous solution, type and amount of eluent, and the flow rates of sample and eluent solutions on the separation efficiency are investigated. The linear dependence of absorbance of lead on its concentration in the initial solution is in the range of 0.5-40.0 ng/mL with the detection limit of 0.13 ng/mL (3(Sb)/m, n = 10). The proposed method is applicable to the analysis of red lipstick, pine leaves, and water samples for their lead contents. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of zinc oxide nanoparticle by sonochemical method and study of their physical and optical properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Samreen Heena, E-mail: samreen.heena.khan@gmail.com; Suriyaprabha, R.; Pathak, Bhawana, E-mail: bhawana.pathak@cug.ac.in

With the miniaturization of crystal size, the fraction of under-coordinated surface atoms becomes dominant, and hence, materials in the nano-regime behave very differently from the similar material in a bulk. Zinc oxide (ZnO), particularly, exhibits extraordinary properties such as a wide direct band gap (3.37 eV), large excitation binding energy (60 meV), low refractive index (1.9), stability to intense ultraviolet (UV) illumination, resistance to high-energy irradiation, and lower toxicity as compared to other semiconductors. This very property makes Zinc Oxide a potential candidate in many application fields, particularly as a prominent semiconductor. Zinc Oxide plays a significant role in manymore » technological advances with its application in semiconductor mediated photocatalytic processes and sensor, solar cells and others. In present study, Zinc Oxide (ZnO) has been synthesized using three different precursors by sonochemical method. Zinc Acetate Dihydrate, Zinc Nitrate Hexahydrate and Zinc Sulphate Heptahydrate used as a precursor for the synthesis process. The synthesized ZnO nanoparticle has been found under the range of ∼50 nm. Zinc oxide nanoparticles were characterized using different characterizing tools. The as-synthesized ZnO was characterized by Fourier Transform-Infrared Spectroscopy (FT-IR) for the determination of functional group; Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy (SEM-EDS) for Morphology and elemental detection respectively, Transmission Electron Microscopy for Particle size distribution and morphology and X-Ray Diffraction (XRD) for the confirmation of crystal structure of the nanomaterial. The optical properties of the ZnO were examined by UV-VIS spectroscopy equipped with Diffuse Reflectance spectroscopy (DRS) confirmed the optical band gap of ZnO-3 around 3.23 eV resembles with the band gap of bulk ZnO (3.37eV). The TEM micrograph of the as-synthesized material showed perfectly spherical shaped nanoparticle under the size range of 50nm. The XRD data showed that the ZnO-3 which was synthesized using Zinc Nitrate Hexahydrate as precursor showed the hexagonal wurtzite crystal structure. The XRD data obtained were compared with the JCPDS standard data. The precursor Zinc Nitrate Hexahydrate (ZnO-3) showed the good yield, monodispersity and size of nanoparticle under the range of 50 nm. The ZnO nanoparticles synthesize using different precursor was found effective in order of ZnO-3, followed by ZnO-1 & ZnO-2. The Synthesized ZnO has wider application in environmental remediation and clean-up as a potential nano-catalyst.« less

Next Generation Trusted Radiation Identification System (NG-TRIS).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flynn, Adam J.; Amai, Wendy A.; Merkle, Peter Benedict

2010-05-01

The original Trusted Radiation Identification System (TRIS) was developed from 1999-2001, featuring information barrier technology to collect gamma radiation template measurements useful for arms control regime operations. The first TRIS design relied upon a multichannel analyzer (MCA) that was external to the protected volume of the system enclosure, undesirable from a system security perspective. An internal complex programmable logic device (CPLD) contained data which was not subject to software authentication. Physical authentication of the TRIS instrument case was performed by a sensitive but slow eddy-current inspection method. This paper describes progress to date for the Next Generation TRIS (NG-TRIS), whichmore » improves the TRIS design. We have incorporated the MCA internal to the trusted system volume, achieved full authentication of CPLD data, and have devised rapid methods to authenticate the system enclosure and weld seals of the NG-TRIS enclosure. For a complete discussion of the TRIS system and components upon which NG-TRIS is based, the reader is directed to the comprehensive user's manual and system reference of Seager, et al.« less

Discovery of novel alkylated (bis)urea and (bis)thiourea polyamine analogues with potent antimalarial activities.

PubMed

Verlinden, Bianca K; Niemand, Jandeli; Snyman, Janette; Sharma, Shiv K; Beattie, Ross J; Woster, Patrick M; Birkholtz, Lyn-Marie

2011-10-13

A series of alkylated (bis)urea and (bis)thiourea polyamine analogues were synthesized and screened for antimalarial activity against chloroquine-sensitive and -resistant strains of Plasmodium falciparum in vitro. All analogues showed growth inhibitory activity against P. falciparum at less than 3 μM, with the majority having effective IC(50) values in the 100-650 nM range. Analogues arrested parasitic growth within 24 h of exposure due to a block in nuclear division and therefore asexual development. Moreover, this effect appears to be cytotoxic and highly selective to malaria parasites (>7000-fold lower IC(50) against P. falciparum) and is not reversible by the exogenous addition of polyamines. With this first report of potent antimalarial activity of polyamine analogues containing 3-7-3 or 3-6-3 carbon backbones and substituted terminal urea- or thiourea moieties, we propose that these compounds represent a structurally novel class of antimalarial agents.

Adsorptive removal of patulin from aqueous solution using thiourea modified chitosan resin.

PubMed

Liu, Bingjie; Peng, Xiaoning; Chen, Wei; Li, Yang; Meng, Xianghong; Wang, Dongfeng; Yu, Guangli

2015-09-01

In the present paper, thiourea modified chitosan resin (TMCR) was firstly prepared through converting hydroxyl groups of chitosan resin into thiol groups, using glutaraldehyde as cross-linking agent and thiourea as modification agent. TMCR was characterized by FTIR, EDXS, SEM, XRD and AFM technologies. Batch adsorption experiments were performed to study the adsorption capacity of TMCR for patulin at different pH, temperature, contact time and patulin concentration. The result showed that TMCR was effective in removal of patulin from aqueous solution. The adsorption capacity of TMCR for patulin was 1.0 mg/g at pH 4.0, 25 °C for 24 h. Adsorption process could be well described by pseudo-first order model, Freundlich isotherm model and intraparticle diffusion model. It indicated that TMCR is expected to be a new material for patulin adsorption from aqueous solutions. Copyright © 2015 Elsevier B.V. All rights reserved.

Novel Route to Transition Metal Isothiocyanate Complexes Using Metal Powders and Thiourea

NASA Technical Reports Server (NTRS)

Harris, Jerry D.; Eckles, William E.; Hepp, Aloysius F.; Duraj, Stan A.; Hehemann, David G.; Fanwick, Phillip E.; Richardson, John

2003-01-01

A new synthetic route to isothiocyanate-containing materials is presented. Eight isothiocyanate- 4-methylpyridine (y-picoline) compounds were prepared by refluxing metal powders (Mn, Fe, Co, Ni, and Cu) with thiourea in y-picoline. With the exception of compound 5,prepared with Co, the isothiocyanate ligand was generated in situ by the isomerization of thiourea to NH4+SCN- at reflux temperatures. The complexes were characterized by x-ray crystallography. Compounds 1,2, and 8 are the first isothiocyanate- 4-methylpyridine anionic compounds ever prepared and structurally characterized. Compounds 1 and 2 are isostructural with four equatorially bound isothiocyanate ligands and two axially bound y-picoline molecules. Compound 8 is a five-coordinate copper(II) molecule with a distorted square-pyramidal geometry. Coordinated picoline and two isothiocyanates form the basal plane and the remaining isothiocyanate is bound at the apex. Structural data are presented for all compounds.

A kinetic method for the determination of thiourea by its catalytic effect in micellar media

NASA Astrophysics Data System (ADS)

Abbasi, Shahryar; Khani, Hossein; Gholivand, Mohammad Bagher; Naghipour, Ali; Farmany, Abbas; Abbasi, Freshteh

2009-03-01

A highly sensitive, selective and simple kinetic method was developed for the determination of trace levels of thiourea based on its catalytic effect on the oxidation of janus green in phosphoric acid media and presence of Triton X-100 surfactant without any separation and pre-concentration steps. The reaction was monitored spectrophotometrically by tracing the formation of the green-colored oxidized product of janus green at 617 nm within 15 min of mixing the reagents. The effect of some factors on the reaction speed was investigated. Following the recommended procedure, thiourea could be determined with linear calibration graph in 0.03-10.00 μg/ml range. The detection limit of the proposed method is 0.02 μg/ml. Most of foreign species do not interfere with the determination. The high sensitivity and selectivity of the proposed method allowed its successful application to fruit juice and industrial waste water.

Anion Binding of One-, Two-, and Three-Armed Thiourea Receptors Examined via Photoelectron Spectroscopy and Quantum Computations.

PubMed

Beletskiy, Evgeny V; Wang, Xue-Bin; Kass, Steven Robert

2016-10-05

A benzene ring substituted with 1-3 thiourea containing arms (1-3) were examined by photoelectron spectroscopy and density functional theory computations. Their conjugate bases and chloride, acetate and dihydrogen phosphate anion clusters are reported. The resulting vertical and adiabatic detachment energies span from 3.93 - 5.82 eV (VDE) and 3.65 - 5.10 (ADE) for the deprotonated species and 4.88 - 5.97 eV (VDE) and 4.45 - 5.60 eV (ADE) for the anion complexes. These results reveal the stabilizing effects of multiple hydrogen bonds and anionic host-guest interactions in the gas phase. Previously measured equilibrium binding constants in aqueous dimethyl sulfoxide for all three thioureas are compared to the present results and cooperative binding is uniformly observed in the gas phase but only for one case (i.e., 3 • H2PO4-) in solution.

The influence of impurities on the growth rate of calcite

NASA Astrophysics Data System (ADS)

Meyer, H. J.

1984-05-01

The effects of 34 different additives on the growth rate of calcite were investigated. An initial growth rate of about one crystal monolayer (3 × 10 -8 cm) per minute was adjusted at a constant supersaturation which was maintained by a control circuit. Then the impurity was added step by step and the reduction of the growth rate was measured. The impurity concentration necessary to reduce the initial growth rate by a certain percentage increased in the order Fe 2+, ATP, P 3O 5-10, P 2O 4-7, (PO 3) 6-6, Zn 2+, ADP, Ce 3+, Pb 2+, carbamyl phosphate, Fe 3+, PO 3-4, Co 2+, Mn 2+, Be 2+, β-glycerophosphate, Ni 2+, Cd 2+, "Tris", phenylphosphate, chondroitine sulphate, Ba 2+, citrate, AMP, Sr 2+, tricarballylate, taurine, SO 2-4, Mg 2+ by 4 orders of magnitude. The most effective additives halved the initial growth rate in concentrations of 2 × 10 -8 mol/1. For Fe 2+ the halving concentration was nearly proportional to the initial rate. The mechanism of inhibition by adsorption of the impurities at growth sites (kinks) is discussed.

Taste and mouthfeel assessment of porous and non-porous silicon microparticles

NASA Astrophysics Data System (ADS)

Shabir, Qurrat; Skaria, Cyrus; Brien, Heather O.; Loni, Armando; Barnett, Christian; Canham, Leigh

2012-07-01

Unlike the trace minerals iron, copper and zinc, the semiconductor silicon has not had its organoleptic properties assessed. Nanostructured silicon provides the nutrient orthosilicic acid through hydrolysis in the gastrointestinal tract and is a candidate for oral silicon supplements. Mesoporous silicon, a nanostructured material, is being assessed for both oral drug and nutrient delivery. Here we use taste panels to determine the taste threshold and taste descriptors of both solid and mesoporous silicon in water and chewing gum base. Comparisons are made with a metal salt (copper sulphate) and porous silica. We believe such data will provide useful benchmarks for likely consumer acceptability of silicon supplemented foodstuffs and beverages.

Field Evidence of Cadmium Phytoavailability Decreased Effectively by Rape Straw and/or Red Mud with Zinc Sulphate in a Cd-Contaminated Calcareous Soil

PubMed Central

Li, Bo; Yang, Junxing; Wei, Dongpu; Chen, Shibao; Li, Jumei; Ma, Yibing

2014-01-01

To reduce Cd phytoavailability in calcareous soils, the effects of soil amendments of red mud, rape straw, and corn straw in combination with zinc fertilization on Cd extractability and phytoavailability to spinach, tomato, Chinese cabbage and radish were investigated in a calcareous soil with added Cd at 1.5 mg kg−1. The results showed that water soluble and exchangeable Cd in soils was significantly decreased by the amendments themselves from 26% to 70%, which resulted in marked decrease by approximately from 34% to 77% in Cd concentration in vegetables. The amendments plus Zn fertilization further decreased the Cd concentration in vegetables. Also cruciferous rape straw was more effective than gramineous corn straw. In all treatments, rape straw plus red mud combined with Zn fertilization was most effective in decreasing Cd phytoavailability in soils, and it is potential to be an efficient and cost-effective measure to ensure food safety for vegetable production in mildly Cd-contaminated calcareous soils. PMID:25303439

Fluorinated tripodal receptors for potentiometric chloride detection in biological fluids.

PubMed

Pankratova, Nadezda; Cuartero, Maria; Jowett, Laura A; Howe, Ethan N W; Gale, Philip A; Bakker, Eric; Crespo, Gastón A

2018-01-15

Fluorinated tripodal compounds were recently reported to be efficient transmembrane transporters for a series of inorganic anions. In particular, this class of receptors has been shown to be suitable for the effective complexation of chloride, nitrate, bicarbonate and sulfate anions via hydrogen bonding. The potentiometric properties of urea and thiourea-based fluorinated tripodal receptors are explored here for the first time, in light of the need for reliable sensors for chloride monitoring in undiluted biological fluids. The ion selective electrode (ISE) membranes with tren-based tris-urea bis(CF 3 ) tripodal compound (ionophore I) were found to exhibit the best selectivity for chloride over major lipophilic anions such as salicylate ( [Formula: see text] ) and thiocyanate ( [Formula: see text] ). Ionophore I-based ISEs were successfully applied for chloride determination in undiluted human serum as well as artificial serum sample, the slope of the linear calibration at the relevant background of interfering ions being close to Nernstian (49.8±1.7mV). The results of potentiometric measurements were confirmed by argentometric titration. Moreover, the ionophore I-based ISE membrane was shown to exhibit a very good long-term stability of potentiometric performance over the period of 10 weeks. Nuclear magnetic resonance (NMR) titrations, potentiometric sandwich membrane experiments and density functional theory (DFT) computational studies were performed to determine the binding constants and suggest 1:1 complexation stoichiometry for the ionophore I with chloride as well as salicylate. Copyright © 2017 Elsevier B.V. All rights reserved.

Raman analysis of complex pigment mixtures in 20th century metal knight shields of the Order of the Elephant.

PubMed

Lauridsen, Clara Bratt; Sanyova, Jana; Simonsen, Kim Pilkjær

2015-11-05

The pigment composition of six painted metal knight shields of the Order of the Elephant dating from the second half of the 20th century belonging to the Danish royal collection were studied using Raman microscopy. By focusing a 785 nm laser with a 50× objective on particles in paint cross sections, it was possible to identify the following 20 compounds: hematite, goethite, chrome red/orange, chrome yellow, zinc chrome yellow, carbon black, toluidine red PR3, chlorinated para red PR4, dinitroaniline orange PO5, phthalocyanine blue PB15, indanthrone blue PB60, ultramarine, Prussian blue, lead white, anatase, rutile, calcium carbonate, barium sulphate, gypsum and dolomite. The components were frequently present in complex pigment mixtures. Additional information was obtained by elemental analysis with scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) to identify cobalt blue, zinc white and cadmium red, as well as to indicate the presence of zinc white in some pigment mixtures. The study allowed a comparison between the industrially applied preparation layers and the artistic paint layers applied by the heraldic painter. Differences in the choice of paint and pigment types were observed on the earliest knight shields, demonstrating a general delay of industrial materials into artist paints. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis and characterization of spin-coated ZnS thin films

NASA Astrophysics Data System (ADS)

Zaman, M. Burhanuz; Chandel, Tarun; Dehury, Kshetramohan; Rajaram, P.

2018-05-01

In this paper, we report synthesis of ZnS thin films using a sol-gel method. A unique aprotic solvent, dimethlysulphoxide (DMSO) has been used to obtain a homogeneous ZnS gel. Zinc acetate and thiourea were used as the precursor sources for Zn and S, respectively, to deposit nanocrystalline ZnS thin films. Optical, structural and morphological properties of the films were studied. Optical studies reveal high transmittance of the samples over the entire visible region. The energy band gap (Eg) for the ZnS thin films is found to be about 3.6 eV which matches with that of bulk ZnS. The interference fringes in transmissions spectrum show the high quality of synthesized samples. Strong photoluminescence peak in the UV region makes the films suitable for optoelectronic applications. X-ray diffraction studies reveal that sol-gel derived ZnS thin films are polycrystalline in nature with hexagonal structure. SEM studies confirmed that the ZnS films show smooth and uniform grains morphology having size in 20-25 nm range. The EDAX studies confirmed that the films are nearly stoichiometric.

An Autoradiographic Study of the Process of Hormone Formation in the Thyroid Gland Under Various Experimental Conditions

DTIC Science & Technology

1960-09-26

to be a generally recognized mechanism of antithyroid action of thiourea derivatives (Astwood, Frank- lin, Chaikoff, and Lerner, Ya. M. Kabak, I. E...expresses an original point of view concerning the mechanisms of the antithyroid action of thiourea: he considers, that an impoverishment of the thyroid...Vol. 30, No. 5, 31. Boyd, Dzh. A., Avtoradiografiya v biologii i meditsine (Auto- radiography in Biology and Medicine ), Moscow, 1957. Fittszheral’d

Rhodium-catalyzed asymmetric hydrogenation of unprotected NH imines assisted by a thiourea.

PubMed

Zhao, Qingyang; Wen, Jialin; Tan, Renchang; Huang, Kexuan; Metola, Pedro; Wang, Rui; Anslyn, Eric V; Zhang, Xumu

2014-08-04

Asymmetric hydrogenation of unprotected NH imines catalyzed by rhodium/bis(phosphine)-thiourea provided chiral amines with up to 97% yield and 95% ee. (1)H NMR studies, coupled with control experiments, implied that catalytic chloride-bound intermediates were involved in the mechanism through a dual hydrogen-bonding interaction. Deuteration experiments proved that the hydrogenation proceeded through a pathway consistent with an imine. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of sulfadiazinyl acyl/aryl thiourea derivatives as calf intestinal alkaline phosphatase inhibitors, pharmacokinetic properties, lead optimization, Lineweaver-Burk plot evaluation and binding analysis.

PubMed

Sajid-Ur-Rehman; Saeed, Aamer; Saddique, Gufran; Ali Channar, Pervaiz; Ali Larik, Fayaz; Abbas, Qamar; Hassan, Mubashir; Raza, Hussain; Fattah, Tanzeela Abdul; Seo, Sung-Yum

2018-06-02

To seek the new medicinal potential of sulfadiazine drug, the free amino group of sulfadiazine was exploited to obtain acyl/aryl thioureas using simple and straightforward protocol. Acyl/aryl thioureas are well recognized bioactive pharmacophore containing moieties. A new series (4a-4j) of sulfadiazine derived acyl/aryl thioureas was synthesized and characterized through spectroscopic and elemental analysis. The synthesized derivatives 4a-4j were subjected to calf intestinal alkaline phosphatase (CIAP) activity. The derivative 4a-4j showed better inhibition potential compared to standard monopotassium phosphate (MKP). The compound 4c exhibited higher potential in the series with IC 50 0.251 ± 0.012 µM (standard KH 2 PO 4 4.317 ± 0.201 µM). Lineweaver-Burk plots revealed that most potent derivative 4c inhibition CIAP via mixed type pathway. Pharmacological investigations showed that synthesized compounds 4a-4j obey Lipinsk's rule. ADMET parameters evaluation predicted that these molecule show significant lead like properties with minimum possible toxicity and can serve as templates in drug designing. The synthetic compounds show none mutagenic and irritant behavior. Molecular docking analysis showed that compound 4c interacts with Asp273, His317 and Arg166 amino acid residues. Copyright © 2018. Published by Elsevier Ltd.

Impact of acid mine drainages on surficial waters of an abandoned mining site.

PubMed

García-Lorenzo, M L; Marimón, J; Navarro-Hervás, M C; Pérez-Sirvent, C; Martínez-Sánchez, M J; Molina-Ruiz, José

2016-04-01

Weathering of sulphide minerals produces a great variety of efflorescences of soluble sulphate salts. These minerals play an important role for environmental pollution, since they can be either a sink or a source for acidity and trace elements. This paper aims to characterise surface waters affected by mining activities in the Sierra Minera of Cartagena-La Union (SE, Spain). Water samples were analysed for trace metals (Zn, Cd, Pb, Cu, As and Fe), major ions (Na(+), K(+), Ca(2+) and Mg(2+)) and anions (F(-), Cl(-), NO3 (-), CO3 (2-), SO4 (2-)) concentrations and were submitted to an "evaporation-precipitation" experiment that consisted in identifying the salts resulting from the evaporation of the water aliquots sampled onsite. Mineralogy of the salts was studied using X-ray diffraction and compared with the results of calculations using VISUAL MINTEQ. The study area is heavily polluted as a result of historical mining and processing activities that has produced large amount of wastes characterised by a high trace elements content, acidic pH and containing minerals resulting from the supergene alteration of the raw materials. The mineralogical study of the efflorescences obtained from waters shows that magnesium, zinc, iron and aluminium sulphates predominate in the acid mine drainage precipitates. Minerals of the hexahydrite group have been quantified together with minerals of the rozenite group, alunogen and other phases such as coquimbite and copiapite. Calcium sulphates correspond exclusively to gypsum. In a semiarid climate, such as that of the study area, these minerals contribute to understand the response of the system to episodic rainfall events. MINTEQ model could be used for the analysis of waters affected by mining activities but simulation of evaporation gives more realistic results considering that MINTEQ does not consider soluble hydrated salts.

Electrochemical preparation of tris(tert-butyldimethylsilyl)cyclopropene and its hydride abstraction to tris(tert-butyldimethylsilyl)cyclopropenium tetrafluoroborate

PubMed Central

Buchholz, Herwig A.; Prakash, G. K. Surya; Deffieux, Denis; Olah, George A.

1999-01-01

Electrochemical reductive tert-butyldimethylsilylation of tetrachlorocyclopropene to 1,2,3-tris(tert-butyldimethylsilyl)cyclopropene, a potential strained precursor for Diels–Alder and related cycloaddition reactions, is described. By hydride abstraction with nitrosonium tetrafluoroborate, 1,2,3-tris(tert-butyldimethylsilyl)cyclopropene is ionized quantitatively to Hückeloid 2π aromatic tris(tert-butyldimethylsilyl)cyclopropenium tetrafluoroborate. PMID:10468551

Aroma-active ester profile of ale beer produced under different fermentation and nutritional conditions.

PubMed

Hiralal, Lettisha; Olaniran, Ademola O; Pillay, Balakrishna

2014-01-01

A broad range of aroma-active esters produced during fermentation are vital for the complex flavour of beer. This study assessed the influence of fermentation temperature, pH, and wort nutritional supplements on the production of yeast-derived ester compounds and the overall fermentation performance. The best fermentation performance was achieved when wort was supplemented with 0.75 g/l l-leucine resulting in highest reducing sugar and FAN (free amino nitrogen) utilization and ethanol production. At optimum fermentation pH of 5, 38.27% reducing sugars and 35.28% FAN was utilized resulting in 4.07% (v/v) ethanol. Wort supplemented with zinc sulphate (0.12 g/l) resulted in 5.01% ethanol (v/v) production and 54.32% reducing sugar utilization. Increase in fermentation temperature from 18°C to room temperature (± 22.5°C) resulted in 17.03% increased ethanol production and 14.42% and 62.82% increase in total acetate ester concentration and total ethyl ester concentration, respectively. Supplementation of worth with 0.12 g/l ZnSO4 resulted in 2.46-fold increase in both isoamyl acetate and ethyl decanoate concentration, while a 7.05-fold and 1.96-fold increase in the concentration of isoamyl acetate and ethyl decanoate, respectively was obtained upon 0.75 g/l l-leucine supplementation. Wort supplemented with l-leucine (0.75 g/l) yielded the highest beer foam head stability with a rating of 2.67, while highest yeast viability was achieved when wort was supplemented with 0.12 g/l zinc sulphate. Results from this study suggest that supplementing wort with essential nutrients required for yeast growth and optimizing the fermentation conditions could be an effective way of improving fermentation performance and controlling aroma-active esters in beer. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Specificity and sensitivity of noninvasive measurement of pulmonary vascular protein leak.

PubMed

Dauber, I M; Pluss, W T; VanGrondelle, A; Trow, R S; Weil, J V

1985-08-01

Noninvasive techniques employing external counting of radiolabeled protein have the potential for measuring pulmonary vascular protein permeability, but their specificity and sensitivity remain unclear. We tested the specificity and sensitivity of a double-radioisotope method by injecting radiolabeled albumin (131I) and erythrocytes (99mTc) into anesthetized dogs and measuring the counts of each isotope for 150 min after injection with an external gamma probe fixed over the lung. We calculated the rate of increase of albumin counts measured by the probe (which reflects the rate at which protein leaks into the extravascular space). To assess permeability we normalized the rate of increase in albumin counts for changes in labeled erythrocyte signal to minimize influence of changes in vascular surface area and thus derived an albumin leak index. We measured the albumin leak index and gravimetric lung water during hydrostatic edema (acutely elevating left atrial pressure by left atrial balloon inflation: mean pulmonary arterial wedge pressure = 22.6 Torr) and in lung injury edema induced by high- (1.0 g/kg) and low-dose (0.25 g/kg) intravenous thiourea. To test specificity we compared hydrostatic and high-dose thiourea edema. The albumin leak index increased nearly fourfold from control after thiourea injury (27.2 +/- 2.3 X 10-4 vs. 7.6 +/- 0.9 X 10-4 min-1) but did not change from control levels after elevating left atrial pressure (8.9 +/- 1.2 X 10-4 min-1) despite comparable increases in gravimetric lung water. To test sensitivity we compared low-dose thiourea with controls. Following low-dose thiourea, the albumin leak index nearly doubled despite the absence of a measurable increase in lung water. We conclude that a noninvasive double radioisotope measurement of pulmonary vascular protein leak, employing external counting techniques and a simplified method of calculation, is specific for lung injury and is also sensitive enough to detect lung injury insufficient to produce detectable pulmonary edema.

Effects of growth temperatures on the physical properties of Cu2ZnSnS4 thin films deposited through spray pyrolysis for solar cell applications

NASA Astrophysics Data System (ADS)

Fadavieslam, M. R.; Keshavarz, S.

2018-02-01

This paper reports the effects of substrate temperature on the structural, optical, and electrical properties of Cu2ZnSnS4 (CZTS) thin films deposited on soda lime glass through spray pyrolysis without sulfurization. Substrate temperatures ranged from 250 to 500 °C at a step of 50 °C, and a precursor solution was prepared by dissolving copper chloride, zinc acetate, zinc chloride, and thiourea in ethanol and di-ionized water. The films were characterized through X-ray diffraction (XRD), field emission scanning electron microscopy, ultraviolet-visible spectroscopy, and electrical resistance and Hall effect measurements, respectively, obtained by two-point probe and van der Pauw techniques. XRD revealed the formation of polycrystalline CZTS thin films and the appearance of relatively intense and sharp diffraction peaks at (112), (200), (220), and (312) of a kesterite phase with (112) preferential orientation, in which the crystalline degree increased as substrate temperature increased. Surface morphological analysis demonstrated the formation of a smooth, compact, and uniform CZTS surface. When substrate temperature increased from 250 to 500 °C, single-crystal grains increased from 6.38 to 28 nm, carrier concentration increased from 3.4 × 1017 to 2.36 × 1019 cm-3, Hall mobility increased from 30.96 to 68.52 cm2/V.S, optical band gap decreased from 1.74 to 1.14 eV, and resistivity decreased from 0.59 to 3.87 × 10-3 Ωcm. Hall effect analysis indicated that the films exhibited p-type conductivity.

Effects of Starting Precursor Ratio on Optoelectrical Properties and Blue Emission of Nanostructured C-ZnS Thin Films Prepared by Spin Coating

NASA Astrophysics Data System (ADS)

Rahimzadeh, N.; Ghodsi, F. E.; Mazloom, J.

2018-02-01

Nanocrystalline cubic zinc sulfide (C-ZnS) thin films have been elaborated by sol-gel spin-coating of Zn(Ac)/thiourea starting precursors at different molar ratios, and their structural, morphological, compositional, optical, electrical, and photoluminescence properties comprehensively investigated. x-ray diffraction results showed that the samples had dominant cubic structure and their crystallinity improved with increasing S content. Morphological characterization of the C-ZnS thin films was carried out by field-emission scanning electron microscopy (FESEM), revealing that the films were smooth with spherical grains included in clusters. Energy-dispersive x-ray and Fourier-transform infrared spectra of ZnS compounds did not show any evidence of impurities. Optical characterization revealed increases of the average optical transmittance and bandgap (from 3.2 eV to 3.56 eV) with increasing S content. The refractive index in the visible region increased with the S content, while the extinction coefficient decreased. The compositional dependence of the optical dispersion parameters (oscillator and dispersion energy), dielectric constant, and surface energy loss function of the films was evaluated. Electrical characterization of the films was carried out using Hall-effect measurements. The ZnS thin films exhibited n-type conductivity, and the electrical resistivity decreased with increasing carrier concentration and mobility due to enhanced crystallite size and reduced structural disorder. Photoluminescence (PL) measurements indicated a blue-shift of the near-band-edge emission. The blue emission peaks centered at about 438 nm and 487 nm were enhanced due to transitions involving interstitial S atoms, surface states, and zinc vacancies.

Ethylene thiourea: thyroid function in two groups of exposed workers.

PubMed Central

Smith, D M

1984-01-01

Ethylene thiourea is manufactured at one factory in the United Kingdom and is mixed into masterbatch rubber at another. Clinical examinations and thyroid function tests were carried out over a period of three years on eight process workers and five mixers and on matched controls. The results show that the exposed mixers, but not exposed process workers, have significantly lower levels of total thyroxine (T4) than the controls. One mixer had an appreciably raised level of thyroid stimulation hormone (TSH). PMID:6743584

Ethylene thiourea: thyroid function in two groups of exposed workers.

PubMed

Smith, D M

1984-08-01

Ethylene thiourea is manufactured at one factory in the United Kingdom and is mixed into masterbatch rubber at another. Clinical examinations and thyroid function tests were carried out over a period of three years on eight process workers and five mixers and on matched controls. The results show that the exposed mixers, but not exposed process workers, have significantly lower levels of total thyroxine (T4) than the controls. One mixer had an appreciably raised level of thyroid stimulation hormone (TSH).

Screening of sunflower cultivars for metal phytoextraction in a contaminated field prior to mutagenesis.

PubMed

Nehnevajova, Erika; Herzig, Rolf; Federer, Guido; Erismann, Karl-Hans; Schwitzguébel, Jean-Paul

2005-01-01

Sunflower can be used for the remediation of metal-contaminated soils. Its high biomass production makes this plant species interestingfor phytoextraction and using sunflower oil for a technical purpose may improve the economic balance of phytoremediation. The aim of the present field study was to screen 15 commercial cultivars of Helianthus annuus L. grown on metal-contaminated soil, to find out the variety with the highest metal extraction, which can be further improved by mutation or in vitro breeding procedures. Two different fertilizers (ammonium sulphate and ammonium nitrate) were also used to enhance the bioavailability of metals in soil Highly significant differences were observed within tested varieties for metal accumulation and extraction efficiency. Furthermore, ammonium nitrate increased cadmium extraction, whereas ammonium sulphate enhanced zinc and lead uptake in most tested cultivars. In this field-based sunflower screening, we found enhanced cumulative Cd, Zn, and Pb extraction efficiency by a factor 4.4 for Salut cultivar. We therefore emphasize that prior to any classical breeding or genetic engineering enhancing metal uptake potential, a careful screening of various genotypes should be done to select the cultivar with the naturally highest metal uptake and to start the genetic improvement with the best available plant material.

Comparative study on the effect of chemicals on Alternaria blight in Indian mustard--a multi-location study in India.

PubMed

Meena, P D; Chattopadhyay, C; Kumar, A; Awasthi, R P; Singh, R; Kaur, S; Thomas, L; Goyal, P; Chand, P

2011-05-01

High severity of Altemaria blight disease is a major constraint in production of rapeseed-mustard in India. The aim of this study was to investigate the suppressive potential of chemicals viz., zinc sulphate, borax, sulphur, potash and calcium sulphate, aqueous extracts viz., Eucalyptus globosus (50 g l-1) leaf extract and garlic (Allium sativum) bulb (20 g l-1) extract, cow urine and bio-agents Trichoderma harzianum, Pseudomonas fluorescence in comparison with the recommended chemical fungicide (mancozeb), against foliar disease Alternaria blight of Indian mustard [Brassica juncea (L.) Czern. and Coss] under five different geographical locations of India. Mancozeb recorded the lowest mean severity (leaf: 33.1%; pod: 26.3%) of Alternaria blight with efficacy of garlic bulb extract alone (leaf = 34.4%; pod = 27.3%) or in combination with cow urine (leaf = 34.2%; pod = 28.6%) being statistically at par with the recommended chemical fungicide. Chemicals also proved effective in reducing Alternaria blight severity on leaves and pods of Indian mustard (leaf = 36.3-37.9%; pod = 27.5-30.1%). The effective treatments besides providing significant reduction in disease severity also enabled increase in dry seed yield of the crop (mancozeb = 2052 kg ha-1; garlic = 2006 kg ha-1; control = 1561 kg ha-1).

SEM, EDX and Raman and infrared spectroscopic study of brianyoungite Zn3(CO3,SO4)(OH)4 from Esperanza Mine, Laurion District, Greece

NASA Astrophysics Data System (ADS)

Frost, Ray L.; López, Andrés; Wang, Lina; Scholz, Ricardo; Sampaio, Ney Pinheiro

2015-10-01

The mineral brianyoungite, a carbonate-sulphate of zinc, has been studied by scanning electron microscopy (SEM) with chemical analysis using energy dispersive spectroscopy (EDX) and Raman and infrared spectroscopy. Multiple carbonate stretching modes are observed and support the concept of non-equivalent carbonate units in the brianyoungite structure. Intense Raman band at 1056 cm-1 with shoulder band at 1038 cm-1 is assigned to the CO32- ν1 symmetric stretching mode. Two intense Raman bands at 973 and 984 cm-1 are assigned to the symmetric stretching modes of the SO42- anion. The observation of two bands supports the concept of the non-equivalence of sulphate units in the brianyoungite structure. Raman bands at 704 and 736 cm-1 are assigned to the CO32- ν4 bending modes and Raman bands at 507, 528, 609 and 638 cm-1 are assigned to the CO32- ν2 bending modes. Multiple Raman and infrared bands in the OH stretching region are observed, proving the existence of water and hydroxyl units in different molecular environments in the structure of brianyoungite. Vibrational spectroscopy enhances our knowledge of the molecular structure of brianyoungite.

Modified melanocortin tetrapeptide Ac-His-dPhe-Arg-Trp-NH at the arginine side chain with ureas and thioureas.

PubMed

Joseph, C G; Sorensen, N B; Wood, M S; Xiang, Z; Moore, M C; Haskell-Luevano, C

2005-11-01

The Ac-His-dPhe-Arg-Trp-NH2 tetrapeptide is a nonselective melanocortin agonist and replacement of Arg in the tetrapeptide with acidic, basic or neutral amino acids results in reduced potency at the melanocortin receptor (MCR) isoforms (MC1R and MC3-5R). To determine the importance of the positive charge and the guanidine moiety for melanocortin activity, a series of urea- and thiourea-substituted tetrapeptides were designed. Replacement of Arg with Lys or ornithine reduced agonist activity at the mouse mMC1 and mMC3-5 receptors, thus supporting the hypothesis that the guanidine moiety is important for receptor potency, particularly at the MC3-5 receptors. The Arg side chain-modified tetrapeptides examined in this study include substituted phenyl, naphthyl, and aliphatic urea and thiourea residues using a Lys side-chain template. These ligands elicit full-agonist pharmacology at the mouse MCRs examined in this study.

Antimicrobial and anticancer activity of some novel fluorinated thiourea derivatives carrying sulfonamide moieties: synthesis, biological evaluation and molecular docking.

PubMed

Ghorab, Mostafa M; Alsaid, Mansour S; El-Gaby, Mohamed S A; Elaasser, Mahmoud M; Nissan, Yassin M

2017-04-07

Various thiourea derivatives have been used as starting materials for compounds with better biological activities. Molecular modeling tools are used to explore their mechanism of action. A new series of thioureas were synthesized. Fluorinated pyridine derivative 4a showed the highest antimicrobial activity (with MIC values ranged from 1.95 to 15.63 µg/mL). Interestingly, thiadiazole derivative 4c and coumarin derivative 4d exhibited selective antibacterial activities against Gram positive bacteria. Fluorinated pyridine derivative 4a was the most active against HepG2 with IC50 value of 4.8 μg/mL. Molecular docking was performed on the active site of MK-2 with good results. Novel compounds were obtained with good anticancer and antibacterial activity especially fluorinated pyridine derivative 4a and molecular docking study suggest good activity as mitogen activated protein kinase-2 inhibitor. Graphical abstract Compound 4a in the active site of MK-2.

Thermodynamic study of dihydrogen phosphate dimerisation and complexation with novel urea- and thiourea-based receptors.

PubMed

Bregović, Nikola; Cindro, Nikola; Frkanec, Leo; Užarević, Krunoslav; Tomišić, Vladislav

2014-11-24

Complexation of dihydrogen phosphate by novel thiourea and urea receptors in acetonitrile and dimethyl sulfoxide was studied in detail by an integrated approach by using several methods (isothermal titration calorimetry, ESI-MS, and (1)H NMR and UV spectroscopy). Thermodynamic investigations into H2PO4(-) dimerisation, which is a process that has been frequently recognised, but rarely quantitatively described, were carried out as well. The corresponding equilibrium was taken into account in the anion-binding studies, which enabled reliable determination of the complexation thermodynamic quantities. In both solvents the thiourea derivatives exhibited considerably higher binding affinities with respect to those containing the urea moiety. In acetonitrile, 1:1 and 2:1 (anion/receptor) complexes formed, whereas in dimethyl sulfoxide only the significantly less stable complexes of 1:1 stoichiometry were detected. The solvent effects on the thermodynamic parameters of dihydrogen phosphate dimerisation and complexation reactions are discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of female odour on male hamsters mediated by the vomeronasal organ.

PubMed

Steel, E; Keverne, E B

1985-08-01

A comparison was made of the response to female vaginal odour, between males that were intact (I), had an ablated vomeronasal epithelium (VNOX) or had the main olfactory epithelium destroyed by zinc sulphate lavage (ZN). I males, after exposure to vaginal odour, can subsequently discriminate between the donor of the odour and other, mismatching females. VNOX males are unable to discriminate. Peripherally anosmic males (ZN) could still discriminate mismatching females. Neither treatment affected the amount of sniffing directed at novel females. This confirms a previous study in which it was found that the non-volatile fraction of the female vaginal discharge is necessary for match/mismatch discrimination and that this is most likely to be sampled via the vomeronasal organ.

Interrogating alkyl and arylalkylpolyamino (bis)urea and (bis)thiourea isosteres as potent antimalarial chemotypes against multiple lifecycle forms of Plasmodium falciparum parasites.

PubMed

Verlinden, Bianca K; de Beer, Marna; Pachaiyappan, Boobalan; Besaans, Ethan; Andayi, Warren A; Reader, Janette; Niemand, Jandeli; van Biljon, Riette; Guy, Kiplin; Egan, Timothy; Woster, Patrick M; Birkholtz, Lyn-Marie

2015-08-15

A new series of potent potent aryl/alkylated (bis)urea- and (bis)thiourea polyamine analogues were synthesized and evaluated in vitro for their antiplasmodial activity. Altering the carbon backbone and terminal substituents increased the potency of analogues in the compound library 3-fold, with the most active compounds, 15 and 16, showing half-maximal inhibitory concentrations (IC50 values) of 28 and 30 nM, respectively, against various Plasmodium falciparum parasite strains without any cross-resistance. In vitro evaluation of the cytotoxicity of these analogues revealed marked selectivity towards targeting malaria parasites compared to mammalian HepG2 cells (>5000-fold lower IC50 against the parasite). Preliminary biological evaluation of the polyamine analogue antiplasmodial phenotype revealed that (bis)urea compounds target parasite asexual proliferation, whereas (bis)thiourea compounds of the same series have the unique ability to block transmissible gametocyte forms of the parasite, indicating pluripharmacology against proliferative and non-proliferative forms of the parasite. In this manuscript, we describe these results and postulate a refined structure-activity relationship (SAR) model for antiplasmodial polyamine analogues. The terminally aryl/alkylated (bis)urea- and (bis)thiourea-polyamine analogues featuring a 3-5-3 or 3-6-3 carbon backbone represent a structurally novel and distinct class of potential antiplasmodials with activities in the low nanomolar range, and high selectivity against various lifecycle forms of P. falciparum parasites. Copyright © 2015 Elsevier Ltd. All rights reserved.

40 CFR 721.10493 - Tris-alkyl-alkoxy melamine polymer (generic).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tris-alkyl-alkoxy melamine polymer... Specific Chemical Substances § 721.10493 Tris-alkyl-alkoxy melamine polymer (generic). (a) Chemical... as tris-alkyl-alkoxy melamine polymer (PMN P-05-417) is subject to reporting under this section for...

40 CFR 721.10493 - Tris-alkyl-alkoxy melamine polymer (generic).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Tris-alkyl-alkoxy melamine polymer... Specific Chemical Substances § 721.10493 Tris-alkyl-alkoxy melamine polymer (generic). (a) Chemical... as tris-alkyl-alkoxy melamine polymer (PMN P-05-417) is subject to reporting under this section for...

Modulation of ruminal and intestinal fermentation by medicinal plants and zinc from different sources.

PubMed

Váradyová, Zora; Mravčáková, Dominika; Holodová, Monika; Grešáková, Ľubomira; Pisarčíková, Jana; Barszcz, Marcin; Taciak, Marcin; Tuśnio, Anna; Kišidayová, Svetlana; Čobanová, Klaudia

2018-06-14

Two experiments were conducted on sheep to determine the effect of dietary supplementation with zinc and a medicinal plant mixture on haematological parameters and microbial activity in the rumen and large intestine. In Experiment 1, 24 male lambs were randomly divided into four groups: One group was fed an unsupplemented basal diet (control), and three groups were fed a diet supplemented with 70 mg Zn/kg diet in the form of Zn sulphate (ZnSO 4 ), a Zn-chelate of glycine hydrate (Zn-Gly) or a Zn-proteinate (Zn-Pro), for five months. The ruminal content was collected separately from each lamb, and batch cultures of ruminal fluid were incubated in vitro with mixture of medicinal plants (Mix) with different roughage:concentrate ratios (800:200 and 400:600, w/w). Bioactive compounds in Mix were quantified by UPLC/MS/MS. In Experiment 2, four sheep were fed a diet consisting of meadow hay and barley grain (400:600, w/w), with Zn-Gly (70 mg Zn/kg diet), Mix (10% replacement of meadow hay) or Zn-Gly and Mix (Zn-Gly-Mix) as supplements in a Latin square design. Mix decreased total gas (p < 0.001) and methane (p < 0.01) production in vitro. In Experiment 1, caecal isobutyrate and isovalerate concentrations varied among the dietary treatments (p < 0.01). The isovalerate concentration of the zinc-supplemented groups in the distal colon was higher (p < 0.001) compared with the control. In Experiment 2, the molar proportion of isobutyrate was the highest in the faeces of the sheep fed the diet with Zn-Gly-Mix (p < 0.01). The plasma zinc concentration was higher in the groups fed a diet supplemented with zinc (p < 0.001). The haematological profile and antioxidant status did not differ between the dietary groups (p > 0.05). The diets containing medicinal plants and organic zinc thus helped to modulate the characteristics of fermentation in ruminants. © 2018 Blackwell Verlag GmbH.

Oral zinc sulphate causes murine hair hypopigmentation and is a potent inhibitor of eumelanogenesis in vivo.

PubMed

Plonka, P M; Handjiski, B; Michalczyk, D; Popik, M; Paus, R

2006-07-01

C57BL/6 a/a mice have been widely used to study melanogenesis, including in electron paramagnetic resonance (EPR) studies. Zinc cations modulate melanogenesis, but the net effect of Zn2+ in vivo is unclear, as the reported effects of Zn2+ on melanogenesis are ambiguous: zinc inhibits tyrosinase and glutathione reductase in vitro, but also enhances the activity of dopachrome tautomerase (tyrosinase-related protein-2) and has agonistic effects on melanocortin receptor signalling. To determine in a C57BL/6 a/a murine pilot study whether excess zinc ions inhibit, enhance or in any other way alter hair follicle melanogenesis in vivo, and to test the usefulness of EPR for this study. ZnSO(4).7H2O was continuously administered orally to C57BL/6 a/a mice during spontaneous and depilation-induced hair follicle cycling (20 mg mL-1; in drinking water; mean+/-SD daily dose 1.2+/-0.53 mL), and hair pigmentation was examined macroscopically, by routine histology and by EPR. Oral zinc cations induced a bright brown lightening of new hair shafts produced during anagen, but without inducing an EPR-detectable switch from eumelanogenesis to phaeomelanogenesis. The total content of melanin in the skin and hair shafts during the subsequent telogen phase, i.e. after completion of a full hair cycle, was significantly reduced in Zn-treated mice (P=0.0005). Compared with controls, melanin granules in precortical hair matrix keratinocytes, hair bulb melanocytes and hair shafts of zinc-treated animals were reduced and poorly pigmented. Over the course of several hair cycles, lasting hair shaft depigmentation was seen during long-term exposure to high-dose oral Zn2+. High-dose oral Zn2+ is a potent downregulator of eumelanin content in murine hair shafts in vivo. The C57BL/6 mouse model offers an excellent tool for further dissecting the as yet unclear underlying molecular basis of this phenomenon, while EPR technology is well suited for the rapid, qualitative and quantitative monitoring of hair pigmentation changes.

76 FR 53451 - 2-(Hydroxymethyl)-2-nitro-1,3-propanediol (Tris Nitro); Amendments To Terminate Uses for Certain...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-26

.../ polymer emulsions; Specialty industrial products. 464-658 Tris Nitro \\TM\\ Brand of The Dow Chemical... emulsions; Specialty nitromethane. industrial products. 464-663 Tris Nitro\\TM\\ Brand of The Dow Chemical Company Use in paints, emulsions and 50% Aqueous Tris thickener solutions; Use in (hydroxymethyl...

TRIS buffer in simulated body fluid distorts the assessment of glass-ceramic scaffold bioactivity.

PubMed

Rohanová, Dana; Boccaccini, Aldo Roberto; Yunos, Darmawati Mohamad; Horkavcová, Diana; Březovská, Iva; Helebrant, Aleš

2011-06-01

The paper deals with the characterisation of the bioactive phenomena of glass-ceramic scaffold derived from Bioglass® (containing 77 wt.% of crystalline phases Na(2)O·2CaO·3SiO(2) and CaO·SiO(2) and 23 wt.% of residual glass phase) using simulated body fluid (SBF) buffered with tris-(hydroxymethyl) aminomethane (TRIS). A significant effect of the TRIS buffer on glass-ceramic scaffold dissolution in SBF was detected. To better understand the influence of the buffer, the glass-ceramic scaffold was exposed to a series of in vitro tests using different media as follows: (i) a fresh liquid flow of SBF containing tris (hydroxymethyl) aminomethane; (ii) SBF solution without TRIS buffer; (iii) TRIS buffer alone; and (iv) demineralised water. The in vitro tests were provided under static and dynamic arrangements. SBF buffered with TRIS dissolved both the crystalline and residual glass phases of the scaffold and a crystalline form of hydroxyapatite (HAp) developed on the scaffold surface. In contrast, when TRIS buffer was not present in the solutions only the residual glassy phase dissolved and an amorphous calcium phosphate (Ca-P) phase formed on the scaffold surface. It was confirmed that the TRIS buffer primarily dissolved the crystalline phase of the glass-ceramic, doubled the dissolving rate of the scaffold and moreover supported the formation of crystalline HAp. This significant effect of the buffer TRIS on bioactive glass-ceramic scaffold degradation in SBF has not been demonstrated previously and should be considered when analysing the results of SBF immersion bioactivity tests of such systems. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Iterative Coupling of Two Different Enones by Nitromethane Using Bifunctional Thiourea Organocatalysts. Stereocontrolled Assembly of Cyclic and Acyclic Structures.

PubMed

Varga, Szilárd; Jakab, Gergely; Csámpai, Antal; Soós, Tibor

2015-09-18

An organocatalytic iterative assembly line has been developed in which nitromethane was sequentially coupled with two different enones using a combination of pseudoenantiomeric cinchona-based thiourea catalysts. Application of unsaturated aldehydes and ketones in the second step of the iterative sequence allows the construction of cyclic syn-ketols and acyclic compounds with multiple contiguous stereocenters. The combination of the multifunctional substrates and ambident electrophiles rendered some organocatalytic transformations possible that have not yet been realized in bifunctional noncovalent organocatalysis.

In vivo procedures for assessment of hair greasiness.

PubMed

Knott, C A; Daykin, K; Ryan, J

1983-06-01

Synopsis Greasy hair is a common problem in Europe. The first step in developing anti-grease hair products must be to establish a sensitive protocol for measuring any changes in perceived hair greasiness. Sensitive clinical trials and in vivo evaluation methods of determining hair greasiness have been developed that show significant differences in the perceived hair greasiness following the use of different shampoos. Products tested in two clinical trials for efficacy as anti-grease shampoos were an anti-grease shampoo containing 2% 3,4-thiolanediol as the active ingredient, and a baby shampoo based on mild surfactants. The same placebo shampoo based on ether sulphates used in typical European shampoo formulations was used in both tests. A shampoo containing 2% zinc pyrithione was included in the trials as a control, since there were indications that this would increase the amount of hair greasiness. Neither of the test products were shown to be effective anti-grease shampoos. The shampoo containing 2% zinc pyrithione was shown to produce significantly more greasiness than both the placebo and the test shampoos. Since significant differences could be shown between the different shampoos, the protocol and in vivo evaluation techniques used in these clinical trials are considered to be validated.

Effect of Thermal Annealing on the Band GAP and Optical Properties of Chemical Bath Deposited ZnSe Thin Films

NASA Astrophysics Data System (ADS)

Ezema, F. I.; Ekwealor, A. B. C.; Osuji, R. U.

2006-05-01

Zinc selenide (ZnSe) thin films were deposited on glass substrate using the chemical bath deposition method at room temperature from aqueous solutions of zinc sulphate and sodium selenosulfate in which sodium hydroxide was employed as complexing agents. The `as-deposited' ZnSe thin films are red in color and annealed in oven at 473 K for 1 hour and on a hot plate in open air at 333 K for 5 minutes, affecting the morphological and optical properties. Optical properties such as absorption coefficient a and extinction coefficient k, were determined using the absorbance and transmission measurement from Unico UV-2102 PC spectrophotometer, at normal incidence of light in the wavelength range of 200-1000 nm. The films have transmittance in VIS-NIR regions that range between 26 and 87%. From absorbance and transmittance spectra, the band gap energy determined ranged between 1.60 eV and 1.75 for the `as deposited' samples, and the annealed samples exhibited a band gap shift of 0.15 eV. The high transmittance of the films together with its large band gap made them good materials for selective coatings for solar cells.

Neurotoxicological and thyroid evaluations of rats developmentally exposed to tris(1,3-dichloro-2-propyl)phosphate (TDICPP) and tris(2-chloro-2-ethyl)phosphate(TCEP)

EPA Science Inventory

ABSTRACT: Tris(1,3-dichloro-2-propyl)phosphate (TDICPP) and tris(2-chloro-2-ethyl)phosphate (TCEP) are organophosphorous flame retardants with widespread usage and human exposures through food, inhalation, and dust ingestion. They have been detected in human tissues including ur...

Refractive index of dark-adapted bacteriorhodopsin and tris(hydroxymethyl)aminomethane buffer between 390 and 880 nm.

PubMed

Heiner, Zsuzsanna; Osvay, Károly

2009-08-10

The refractivity of wild-type bacteriorhodopsin (bR(WT)) suspended in tris(hydroxymethyl)aminomethane (TRIS) buffer has been measured in the spectral range of 390-840 nm by the method of angle of minimal deviation with the use of a hollow glass prism. The refractive indices of pure bR(WT) as well as of TRIS buffer have been determined from the concentration dependent refraction values. Sellmeier-type dispersion equations have been fitted for both the TRIS buffer and pure bR(WT).

The sulphation of chondroitin sulphate in embryonic chicken cartilage

PubMed Central

Robinson, H. C.

1969-01-01

1. Whole tissue preparations and subcellular fractions from embryonic chicken cartilage were used to measure the rate of incorporation of inorganic sulphate into chondroitin sulphate in vitro. 2. In cartilage from 14-day-old embryos, [35S]sulphate is incorporated to an equal extent into chondroitin 4-sulphate and chondroitin 6-sulphate at a rate of 1·5nmoles of sulphate/hr./mg. dry wt. of cartilage. 3. Microsomal and soluble enzyme preparations from embryonic cartilage catalyse the transfer of sulphate from adenosine 3′-phosphate 5′-sulphatophosphate into both chondroitin 4-sulphate and chondroitin 6-sulphate. 4. The effects of pH, ionic strength, adenosine 3′-phosphate 5′-sulphatophosphate concentration and acceptor chondroitin sulphate concentration on the soluble sulphotransferase activity were examined. These factors all influence the activity of the sulphotransferase, and pH and incubation time also influence the percentage of chondroitin 4-sulphate formed. PMID:5807213

7 CFR 160.10 - Sulphate wood turpentine.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 3 2014-01-01 2014-01-01 false Sulphate wood turpentine. 160.10 Section 160.10... STANDARDS FOR NAVAL STORES General § 160.10 Sulphate wood turpentine. The designation “sulphate wood... in the sulphate process of cooking wood pulp, and commonly known as sulphate turpentine or sulphate...

7 CFR 160.10 - Sulphate wood turpentine.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 3 2013-01-01 2013-01-01 false Sulphate wood turpentine. 160.10 Section 160.10... STANDARDS FOR NAVAL STORES General § 160.10 Sulphate wood turpentine. The designation “sulphate wood... in the sulphate process of cooking wood pulp, and commonly known as sulphate turpentine or sulphate...

7 CFR 160.10 - Sulphate wood turpentine.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 3 2012-01-01 2012-01-01 false Sulphate wood turpentine. 160.10 Section 160.10... STANDARDS FOR NAVAL STORES General § 160.10 Sulphate wood turpentine. The designation “sulphate wood... in the sulphate process of cooking wood pulp, and commonly known as sulphate turpentine or sulphate...

7 CFR 160.10 - Sulphate wood turpentine.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Sulphate wood turpentine. 160.10 Section 160.10... STANDARDS FOR NAVAL STORES General § 160.10 Sulphate wood turpentine. The designation “sulphate wood... in the sulphate process of cooking wood pulp, and commonly known as sulphate turpentine or sulphate...

7 CFR 160.10 - Sulphate wood turpentine.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Sulphate wood turpentine. 160.10 Section 160.10... STANDARDS FOR NAVAL STORES General § 160.10 Sulphate wood turpentine. The designation “sulphate wood... in the sulphate process of cooking wood pulp, and commonly known as sulphate turpentine or sulphate...

Quantitative studies of sulphate conjugation by isolated rat liver cells using [35S]sulphate.

PubMed

Dawson, J; Knowles, R G; Pogson, C I

1991-06-21

We have developed a simple, rapid and sensitive method for the study of sulphate conjugation in isolated liver cells based on the incorporation of 35S from [35S]sulphate. Excess [35S]sulphate is removed by a barium precipitation procedure, leaving [35S]sulphate conjugates in solution. We have used this method to examine the kinetics of sulphation of N-acetyl-p-aminophenol (acetaminophen), 4-nitrophenol and 1-naphthol in isolated rat liver cells. The efficiency of recovery of the sulphate conjugates was greater than 86%. The method is applicable to the quantitative study of sulphate conjugation of any substrate which forms a sulphate conjugate that is soluble in the presence of barium, without the need for standards or radiolabelled sulphate acceptors.

Evidence of photo- and thermal-induced reversible intermolecular hydrogen-atom transfer in. gamma. -irradiated thiourea clathrates as studied by electron spin resonance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ichikawa, T.

1979-05-17

There has been a report (M. Iwasaki and Toriyama) on an electron spin resonance study of reversible intramolecular radical conversion due to photo- and thermal-induced H-atom transfer. Schlenk, Brown, White, Chatini, and Nakatani reported H-atom abstraction of a photostimulated allylic radical from its neighbor molecules and thermal recovery of the allylic radical from photoirradiation in a thiourea clathrate. Radiolysis of a thiourea clathrate containing a mixture of 10 mol% 2,3-dimethylbutadiene and 90 mol% 2,3-dimethylbutane gave a resolved room-temperature spectrum. The result seemed to suggest that the monomer radical was stabilized in the canal even at room temperature in the presencemore » of the inert DBA molecules which might block chain propagation. Results suggested that the photostimulated R/sub 1/, radicals abstract H atoms from DBA molecules to form tetramethylethylene molecules and R/sub 2/ radicals and that the R/sub 2/ radicals produced by photoirradiation abstract H atoms from TME molecules to regenerate R/sub 1/ radicals and DBA molecules. 2 figures. (DP)« less

Fluoride-selective colorimetric sensor based on thiourea binding site and anthraquinone reporter.

PubMed

Wu, Fang-ying; Hu, Mei-hua; Wu, Yu-mei; Tan, Xiao-fang; Zhao, Yong-qiang; Ji, Zhao-jun

2006-11-01

A structurally simple colorimetric sensor, N-4-nitrobenzene-N'-1'-anthraquinone-thiourea (1), for anions was synthesized and characterized by (1)H NMR, ESI mass and IR methods. In acetonitrile, the addition of F(-) changed 1 solution from colorless to yellow. In the presence of other anions such as CH(3)CO(2)(-), H(2)PO(4)(-), HSO(4)(-) and Cl(-), however, the absorption spectrum of 1 was slightly red shifted with no obvious color changes observed. The association constants of anionic complexes followed the order of F(-)>CH(3)CO(2)(-)>H(2)PO(4)(-)>HSO(4)(-)>Cl(-)>Br(-), which was different from the order of anion basicity. AM1 calculation results indicated that the most stable configuration of 1 existed in the Z-E-conformation with a six-membered ring via intramolecular hydrogen bond. This made thiourea moiety of 1 in an unfavorable conformation to bond with oxygen-anionic substrates such as CH(3)CO(2)(-) and H(2)PO(4)(-), thus leading to a high selectivity and sensitivity for the detection of F(-).

Adsorption of Congo red dye onto antimicrobial terephthaloyl thiourea cross-linked chitosan hydrogels.

PubMed

El-Harby, Nouf F; Ibrahim, Shaimaa M A; Mohamed, Nadia A

2017-11-01

Adsorption capacity of three antimicrobial terephthaloyl thiourea cross-linked chitosan hydrogels for Congo red dye removal from its aqueous solution has been investigated for the first time in this work. These hydrogels were prepared by reacting chitosan with various amounts of terephthaloyl diisothiocyanate cross-linker. The effect of the hydrogel structural variations and several dye adsorption processing parameters to achieve the best adsorption capacity were investigated. The hydrogels' structural variations were obtained by varying their terephthaloyl thiourea moieties content. The processing variables included initial concentration of the dye solution, temperature and time of exposure to the dye. The adsorption kinetics and isotherms showed that the sorption processes were better fitted by the pseudo-second-order equation and the Langmuir equation, respectively. On the basis of the Langmuir analysis Congo red dye gave the maximum sorption capacity of 44.248 mg/g. The results obtained confirmed that the sorption phenomena are most likely to be controlled by chemisorption process. The adsorption reaction was endothermic and spontaneous according to the calculated results of adsorption thermodynamics.

Recognition of anions using urea and thiourea substituted calixarenes: A density functional theory study of non-covalent interactions

NASA Astrophysics Data System (ADS)

Athar, Mohd; Lone, Mohsin Y.; Jha, Prakash C.

2018-02-01

Designing of new calixarene receptors for the selective binding of anions is an age-old concept; even though expected outcomes from this field are at premature stage. Herein, we have performed quantum chemical calculations to provide structural basis of anion binding with urea and thiourea substituted calixarenes (1, 2, and 3). In particular, spherical halides (F-, Cl-, Br-) and linear anions (CN-, N3-, SCN-) were modelled for calculating binding energies with receptor 1, 2 and 3 followed by their marked IR vibrations; taking the available experimental information into account. We found that the thiourea substitutions have better capability to stabilize the anions. Results have suggested that the structural behaviour of macrocyclic motifs were responsible for displaying the anion binding potentials. Moreover, second order "charge transfer" interactions of n-σ∗NH and n-σ∗OH type along the H-bond axis played critical role in developing hydrogen bonds. The present work also examines the role of non-covalent interactions (NCI) and their effects on thermodynamic and chemical-reactivity descriptors.

The extraction of plasma 3-hydroxy-17-oxo steroid sulphates and the measurement of the constituent dehydroepiandrosterone sulphate and androsterone sulphate

PubMed Central

McKenna, Jean; Rippon, A. E.

1965-01-01

1. A simple method for the extraction of 17-oxo steroid sulphates of plasma is described; glucosiduronates and orthophosphates are extracted, but to a smaller extent. 2. Four methods of analyses of the extracts are given and are relatively simple. Three of these are specific for steroid sulphates and two measure the sulphate conjugates directly. 3. Values for dehydroepiandrosterone sulphate and androsterone sulphate concentrations of normal and pathological plasmas are given. PMID:14333546

Wilson's disease-cause of mortality in 164 patients during 1992-2003 observation period.

PubMed

Członkowska, A; Tarnacka, B; Litwin, T; Gajda, J; Rodo, M

2005-06-01

We studied the cause of death in a consecutive series of 164 patients with Wilson's disease (WD) diagnosed over an 11 year period. A total of 20 [12% (95% CI 10.3-16.0)] died during the observation period. The relative survival rate of all patients in our group was statistically smaller than in Polish population. The main cause of death was the diagnosis in advanced stage of disease, but in six patients presenting with mild signs, we observed the progression of the disease despite treatment. There was no difference in mortality rate in patients treated with d-penicillamine or zinc sulphate as initial therapy. The prognosis for survival in the majority of WD patients is favourable, provided that therapy is introduced early.

Insights Into the Solution Crystallization of Oriented Alq3 and Znq2 Microprisms and Nanorods.

PubMed

Boulet, Joel; Mohammadpour, Arash; Shankar, Karthik

2015-09-01

Optimized solution-based methods to grow high quality micro- and nanocrystals of organic semi-conductors with defined size, shape and orientation are important to a variety of optoelectronic applications. In this context, we report the growth of single crystal micro- and nanostructures of the organic semiconductors Tris(8-hydroxyquinoline)aluminum (Alq3) and bis(8-hydroxyquinoline)zinc (Znq2) terminating in flat crystal planes using a combination of evaporative and antisolvent crystallization. By controlling substrate-specific nucleation and optimizing the conditions of growth, we generate vertically-oriented hexagonal prism arrays of Alq3, and vertical half-disks and sharp-edged rectangular prisms of Znq2. The effect of process variables such as ambient vapour pressure, choice of anti-solvent and temperature on the morphology and crystal habit of the nanostructures were studied and the results of varying them catalogued to gain a better understanding of the mechanism of growth.

Strategies for the solid-phase diversification of poly-L-proline-type II peptide mimic scaffolds and peptide scaffolds through guanidinylation.

PubMed

Flemer, Stevenson; Wurthmann, Alexander; Mamai, Ahmed; Madalengoitia, José S

2008-10-03

A strategy for the solid-phase diversification of PPII mimic scaffolds through guanidinylation is presented. The approach involves the synthesis N-Pmc-N'-alkyl thioureas as diversification reagents. Analogues of Fmoc-Orn(Mtt)-OH can be incorporated into a growing peptide chain on Wang resin. Side chain deprotection with 1% TFA/CH2Cl2 followed by EDCI-mediated reaction of N-Pmc-N'-alkyl thioureas with the side chain amine affords arginine analogues with modified guanidine head groups. The scope, limitations, and incidental chemistry are discussed.

Treatment of zinc-rich acid mine water in low residence time bioreactors incorporating waste shells and methanol dosing.

PubMed

Mayes, W M; Davis, J; Silva, V; Jarvis, A P

2011-10-15

Bioreactors utilising bacterially mediated sulphate reduction (BSR) have been widely tested for treating metal-rich waters, but sustained treatment of mobile metals (e.g. Zn) can be difficult to achieve in short residence time systems. Data are presented providing an assessment of alkalinity generating media (shells or limestone) and modes of metal removal in bioreactors receiving a synthetic acidic metal mine discharge (pH 2.7, Zn 15 mg/L, SO(4)(2-) 200mg/L, net acidity 103 mg/L as CaCO(3)) subject to methanol dosing. In addition to alkalinity generating media (50%, v.v.), the columns comprised an organic matrix of softwood chippings (30%), manure (10%) and anaerobic digested sludge (10%). The column tests showed sustained alkalinity generation, which was significantly better in shell treatments. The first column in each treatment was effective throughout the 422 days in removing >99% of the dissolved Pb and Cu, and effective for four months in removing 99% of the dissolved Zn (residence time: 12-14 h). Methanol was added to the feedstock after Zn breakthrough and prompted almost complete removal of dissolved Zn alongside improved alkalinity generation and sulphate attenuation. While there was geochemical evidence for BSR, sequential extraction of substrates suggests that the bulk (67-80%) of removed Zn was associated with Fe-Mn oxide fractions. Copyright © 2011 Elsevier B.V. All rights reserved.

Metallohydrolase biomimetics with catalytic and structural flexibility.

PubMed

Mendes, Luisa L; Englert, Daniel; Fernandes, Christiane; Gahan, Lawrence R; Schenk, Gerhard; Horn, Adolfo

2016-11-22

The structural and functional properties of zinc(ii) complexes of two nitrogen rich polydentate ligands, HTPDP = 1,3-bis(bis-pyridin-2-ylmethylamino)propan-2-ol and HTPPNOL = N,N,N'-tris-(2-pyridylmethyl)-1,3-diaminopropan-2-ol, are compared. HTPDP is a hepta-dentate ligand with four pyridyl groups attached to a 1,3-diaminopropan-2-ol backbone while HTPPNOL contains only three pyridyl groups. In reactions with Zn(ClO 4 ) 2 , HTPDP forms a dinuclear zinc compound [Zn 2 (TPDP)(OAc)](ClO 4 ) 2 , 1. On the other hand, mononuclear [Zn(HTPPNOL)](ClO 4 ) 2 , 2, and tetranuclear [Zn 4 (TPPNOL) 2 (OAc) 3 ](ClO 4 ) 3 , 3, complexes were isolated with the ligand HTPPNOL. Kinetic measurements with the substrate bis(2,4-dinitrophenyl)phosphate (BDNPP) revealed that compound 1 (k cat = 31.4 × 10 -3 min -1 ) is more reactive than 3 (k cat = 7.7 × 10 -3 min -1 ) at pH = 8.5, whilst the mononuclear compound 2 is inactive. Compound 1 displays a typical steady-state kinetic behaviour, while compound 3 exhibits steady-state behaviour only ∼120 s after starting the reaction, preceded by a burst-phase. 31 P NMR studies confirm that 1 can promote the hydrolysis of both ester bonds in BDNPP, generating the monoester DNPP and inorganic phosphate in the process. In contrast, DNPP is not a substrate for 3. The crystal structure of the complex formed by 3 and DNPP reveals the formation of a tetranuclear zinc complex [Zn 4 (TPPNOL) 2 (DNPP) 2 ](ClO 4 ) 2 , 4, in which the phosphate moiety of DNPP adopts an unusual tridentate μ-η 1 :η 1 :η 1 coordination mode.

Sulphation of proteochondroitin and 4-methylumbelliferyl beta-D-xyloside-chondroitin formed by mouse mastocytoma cells cultured in sulphate-deficient medium.

PubMed Central

Silbert, J E; Sugumaran, G; Cogburn, J N

1993-01-01

Mouse mastocytoma cells were cultured in medium containing [3H]GlcN and concentrations of [35S]sulphate varying from 0.01 to 0.5 mM. Intracellular [35S]sulphate incorporation increased severalfold from the lowest concentrations, reaching a maximum at 0.1-0.2 mM, whereas incorporation of [3H]hexosamine remained constant at all sulphate concentrations. Proteo[3H]-chondroitin [35S]sulphate was isolated and incubated with chondroitin ABC lyase, yielding 35S-labelled and/or 3H-labelled delta Di-0S and delta Di-4S disaccharide products. The increasing percentage of delta Di-4S was consistent with the increasing sulphate incorporation at each higher [35S]sulphate concentration. Examination of proteochondroitin [35S]sulphate size by Sepharose CL-6B chromatography indicated a range consistent with various numbers of glycosaminoglycan chains on the protease-resistant serglycin core protein. Alkali-cleaved chondroitin [35S]sulphate products indicated similar size distributions at all sulphate concentrations with no indication of preferential sulphation being related to smaller or larger size. DEAE-cellulose chromatography of [3H]chondroitin [35S]sulphate glycosaminoglycans indicated a random undersulphation as [35S]sulphate concentration was lowered. Addition of 4-methylumbelliferyl beta-D-xyloside to the cultures resulted in a 2-2.5-fold stimulation of [3H]chondroitin [35S]sulphate synthesis with formation of beta-xyloside-[3H]chondroitin [35S]sulphate which was much smaller, as estimated by Sepharose CL-6B chromatography, than the decreased amount of [3H]chondroitin [35S]sulphate derived from proteo[3H]chondroitin [35S]sulphate. Much higher concentrations of sulphate were necessary to produce sulphation of the beta-xyloside-[3H]chondroitin comparable with that of proteo[3H]-chondroitin, as indicated by chondroitin ABC lyase products and DEAE-cellulose chromatography. The specific radioactivities of the [3H]GalN in the proteo[3H]chondroitin [35S]sulphate and beta-xyloside-[3H]chondroitin [35S]sulphate were calculated from the 3H and 35S c.p.m. of isolated dual-labelled delta Di-4S from each, and indicated that the presence of the beta-xyloside resulted in a dilution of the [3H]GlcN by endogenous GlcN that was 4 times higher than that of cultures lacking the beta-xyloside. The higher sulphate concentrations needed for sulphation of beta-xyloside-chondroitin suggests that the membrane-bound nature of the proteochondroitin acceptor in juxtaposition to a chondroitin sulphate-synthesizing enzyme complex effectively reduces the apparent Km for adenosine 3'-phosphate 5'-phosphosulphate. PMID:8250831

Metabolism of dietary sulphate: absorption and excretion in humans.

PubMed Central

Florin, T; Neale, G; Gibson, G R; Christl, S U; Cummings, J H

1991-01-01

Dietary sulphate may affect colonic pathophysiology because sulphate availability determines in part the activity of sulphate reducing bacteria in the bowel. The main product of sulphate reducing bacterial oxidative metabolism, hydrogen sulphide, is potentially toxic. Although it is generally believed that the sulphate ion is poorly absorbed, there are no available data on how much sulphate reaches the colon nor on the relative contributions from diet and endogenous sources. To resolve these questions, balance studies were performed on six healthy ileostomists and three normal subjects chosen because they did not have detectable sulphate reducing bacteria in their faeces. The subjects were fed diets which varied in sulphate content from 1.6-16.6 mmol/day. Sulphate was measured in diets, faeces (ileal effluent in ileostomists), and urine by anion exchange chromatography with conductivity detection. Overall there was net absorption of dietary sulphate, with the absorptive capacity of the gastrointestinal tract plateauing at 5 mmol/day in the ileostomists and exceeding 16 mmol/day in the normal subjects. Endogenous secretion of sulphate in the upper gastrointestinal tract was from 0.96-2.6 mmol/day. The dietary contribution to the colonic sulphate pool ranged up to 9 mmol/day, there being linear identity between diet and upper gastrointestinal losses for intakes above 7 mmol/day. Faecal losses of sulphate were trivial (less than 0.5 mmol/day) in the normal subjects at all doses. It is concluded that diet and intestinal absorption are the principal factors affecting the amounts of sulphate reaching the colon. Endogenous secretion of sulphate by colonic mucosa may also be important in determining amounts of sulphate in the colon. PMID:1855683

Sulphate in Pregnancy

PubMed Central

Dawson, Paul A.; Elliott, Aoife; Bowling, Francis G.

2015-01-01

Sulphate is an obligate nutrient for healthy growth and development. Sulphate conjugation (sulphonation) of proteoglycans maintains the structure and function of tissues. Sulphonation also regulates the bioactivity of steroids, thyroid hormone, bile acids, catecholamines and cholecystokinin, and detoxifies certain xenobiotics and pharmacological drugs. In adults and children, sulphate is obtained from the diet and from the intracellular metabolism of sulphur-containing amino acids. Dietary sulphate intake can vary greatly and is dependent on the type of food consumed and source of drinking water. Once ingested, sulphate is absorbed into circulation where its level is maintained at approximately 300 μmol/L, making sulphate the fourth most abundant anion in plasma. In pregnant women, circulating sulphate concentrations increase by twofold with levels peaking in late gestation. This increased sulphataemia, which is mediated by up-regulation of sulphate reabsorption in the maternal kidneys, provides a reservoir of sulphate to meet the gestational needs of the developing foetus. The foetus has negligible capacity to generate sulphate and thereby, is completely reliant on sulphate supply from the maternal circulation. Maternal hyposulphataemia leads to foetal sulphate deficiency and late gestational foetal death in mice. In humans, reduced sulphonation capacity has been linked to skeletal dysplasias, ranging from the mildest form, multiple epiphyseal dysplasia, to achondrogenesis Type IB, which results in severe skeletal underdevelopment and death in utero or shortly after birth. Despite being essential for numerous cellular and metabolic functions, the nutrient sulphate is largely unappreciated in clinical settings. This article will review the physiological roles and regulation of sulphate during pregnancy, with a particular focus on animal models of disturbed sulphate homeostasis and links to human pathophysiology. PMID:25746011

Calcium sulphate in ammonium sulphate solution

USGS Publications Warehouse

Sullivan, E.C.

1905-01-01

Calcium sulphate, at 25?? C., is two-thirds as soluble in dilute (o.i mol per liter) and twice as soluble in concentrated (3 mois per liter) ammonium sulphate solution as in water. The specific electric conductivity of concentrated ammonium sulphate solutions is lessened by saturating with calcium sulphate. Assuming that dissociation of ammonium sulphate takes place into 2NH4?? and SO4" and of calcium sulphate into Ca and SO4" only, and that the conductivity is a measure of such dissociation, the solubility of calcium sulphate in dilute ammonium sulphate solutions is greater than required by the mass-law. The conductivity of the dilute mixtures may be accurately calculated by means of Arrhenius' principle of isohydric solutions. In the data obtained in these calculations, the concentration of non-dissociated calcium sulphate decreases with increasing ammonium sulphate. The work as a whole is additional evidence of the fact that we are not yet in possession of all the factors necessary for reconciling the mass-law to the behavior of electrolytes. The measurements above described were made in the chemical laboratory of the University of Michigan.

Influence of bis-thiourea nickel nitrate on the structural, optical, electrical, thermal and mechanical behavior of a KDP single crystal for NLO applications

NASA Astrophysics Data System (ADS)

Rasal, Y. B.; Shaikh, R. N.; Shirsat, M. D.; Kalainathan, S.; Hussaini, S. S.

2017-03-01

A single crystal of bis-thiourea nickel nitrate (BTNN) doped potassium dihydrogen phosphate (KDP) has been grown from solution at room temperature by a slow evaporation technique. The cell parameters of the grown crystals were determined using single crystal x-ray diffraction analysis. The different functional groups of the grown crystal were confirmed using Fourier transform infrared analysis. The improved optical parameters of the grown crystal have been evaluated in the range of 200-900 nm using UV-visible spectral analysis. The grown crystal was transparent in the entire visible region and the band gap value was found to be 4.96 eV. The influence of BTNN on the third order nonlinear optical properties of KDP crystal has been investigated by means of the Z-scan technique. The second harmonic generation (SHG) efficiency of grown crystal measured using a Nd-YAG laser is 1.98 times higher than that of pure KDP. The third order nonlinear optical susceptibility (χ 3) and nonlinear absorption coefficient (β) of BTNN doped KDP crystal is found to be 1.77  ×  10-5 esu and 5.57  ×  10-6 cm W-1 respectively. The laser damage threshold (LDT) energy for the grown crystal has been measured by using a Q-switched Nd:YAG laser source. The bis-thiourea nickel nitrate shows authoritative impact on the dielectric properties of doped crystal. The influence of bis-thiourea nickel nitrate on the mechanical behavior of KDP crystal has been investigated using Vickers microhardness intender. The thermal behavior of BTNN doped KDP crystal has been analyzed by TGA/DTA analysis.

Fertility results using bovine semen cryopreserved with extenders based on egg yolk and soy bean extract.

PubMed

van Wagtendonk-de Leeuw, A M; Haring, R M; Kaal-Lansbergen, L M; den Daas, J H

2000-07-01

Semen extenders containing components such as egg yolk and skim milk are difficult to standardize and they introduce the risk of microbial contamination. A well-defined extender not originating from animal tissues would present a valuable contribution to the AI industry. We evaluated the fertility of bovine semen cryopreserved with 3 different extenders: 1) TRIS-Standard, prepared at 2 local AI laboratories, containing 20% (v/v) pasteurized egg yolk, 2) TRIS-Concentrate, prepared by adding 20% (v/v) pasteurized egg yolk and 1:5 (v/v) nonpyrogenic water, and 3) Biociphos Plus, a soybean extract containing extender, prepared by adding 1:5 nonpyrogenic water. Ejaculates of 4 Holstein bulls were split into 3 aliquots and cryopreserved with the 3 extenders. Prior to this study, the semen dose-response curve for each of the 4 bulls was developed in a field trial by freezing the semen and randomly distributing the straws throughout the Netherlands for insemination. Optimal semen doses were thus established to detect the effect of extenders on fertility, evaluated by 56-day non-return rate (NR56), and by the estimated conception rate and the calving rate, given a conception. We used the multiphasic model developed by Grossman et al. (7). A total of 22,246 first and second inseminations were recorded. The NR56 ranged among bulls from 67.0 to 70.1% for Tris-Standard, from 67.5 to 69.9% for Tris-Concentrate and from 60.2 to 66.7% for Biociphos Plus. No significant differences in NR56 were detected between Tris-Standard and Tris-Concentrate (P=0.54), whereas Biociphos Plus resulted in a significantly lower NR56 than Tris-Standard and Tris-Concentrate (P<0.05). Estimated conception rate was 72.1, 73.6 and 69.6% and estimated calving rate, given a conception was 80.6, 78.3 and 77.1 for Tris-Standard, Tris-Concentrate and Biociphos Plus, respectively. These results indicate that 1) semen extended with a custom made TRIS-Concentrate can be succesfully used in the field resulting in comparable fertility with Tris-Standard; 2) semen extended with Biociphos Plus results in a significant reduction in the NR56; 3) extender source may affect both conception rate and calving rate, given a conception, i.e., extrinsic and intrinsic sperm factors (4).

Synthesis and structures of cadmium carboxylate and thiocarboxylate compounds with a sulfur-rich coordination environment: Carboxylate exchange kinetics involving tris(2-mercapto-1- t-butylimidazolyl)hydroborato cadmium complexes, [Tm But]Cd(O 2CR)

DOE PAGES

Kreider-Mueller, Ava; Quinlivan, Patrick J.; Owen, Jonathan S.; ...

2015-03-31

Here, a series of cadmium carboxylate compounds in a sulfur-rich environment provided by the tris(2- tert-butylmercaptoimidazolyl)hydroborato ligand, namely, [Tm But]CdO 2CR, has been synthesized via the reactions of the cadmium methyl derivative [Tm But]CdMe with RCO 2H. Such compounds mimic aspects of cadmium-substituted zinc enzymes and also the surface atoms of cadmium chalcogenide crystals, and have therefore been employed to model relevant ligand exchange processes. Significantly, both 1H and 19F NMR spectroscopy demonstrate that the exchange of carboxylate groups between [Tm But]Cd(κ 2-O 2CR) and the carboxylic acid RCO 2H is facile on the NMR time scale, even at lowmore » temperature. Analysis of the rate of exchange as a function of concentration of RCO 2H indicates that reaction occurs via an associative rather than dissociative pathway. In addition to carboxylate compounds, the thiocarboxylate derivative [Tm But]Cd[κ 1-SC(O)Ph] has also been synthesized via the reaction of [Tm But]CdMe with thiobenzoic acid. The molecular structure of [Tm But]Cd[κ 1-SC(O)Ph] has been determined by X-ray diffraction, and an interesting feature is that, in contrast to the carboxylate derivatives [Tm But]Cd(κ 2-O 2CR), the thiocarboxylate ligand binds in a κ 1 manner via only the sulfur atom.« less

Synthesis and structures of cadmium carboxylate and thiocarboxylate compounds with a sulfur-rich coordination environment: Carboxylate exchange kinetics involving tris(2-mercapto-1- t-butylimidazolyl)hydroborato cadmium complexes, [Tm But]Cd(O 2CR)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kreider-Mueller, Ava; Quinlivan, Patrick J.; Owen, Jonathan S.

Here, a series of cadmium carboxylate compounds in a sulfur-rich environment provided by the tris(2- tert-butylmercaptoimidazolyl)hydroborato ligand, namely, [Tm But]CdO 2CR, has been synthesized via the reactions of the cadmium methyl derivative [Tm But]CdMe with RCO 2H. Such compounds mimic aspects of cadmium-substituted zinc enzymes and also the surface atoms of cadmium chalcogenide crystals, and have therefore been employed to model relevant ligand exchange processes. Significantly, both 1H and 19F NMR spectroscopy demonstrate that the exchange of carboxylate groups between [Tm But]Cd(κ 2-O 2CR) and the carboxylic acid RCO 2H is facile on the NMR time scale, even at lowmore » temperature. Analysis of the rate of exchange as a function of concentration of RCO 2H indicates that reaction occurs via an associative rather than dissociative pathway. In addition to carboxylate compounds, the thiocarboxylate derivative [Tm But]Cd[κ 1-SC(O)Ph] has also been synthesized via the reaction of [Tm But]CdMe with thiobenzoic acid. The molecular structure of [Tm But]Cd[κ 1-SC(O)Ph] has been determined by X-ray diffraction, and an interesting feature is that, in contrast to the carboxylate derivatives [Tm But]Cd(κ 2-O 2CR), the thiocarboxylate ligand binds in a κ 1 manner via only the sulfur atom.« less

Minocycline Rescues from Zinc-Induced Nigrostriatal Dopaminergic Neurodegeneration: Biochemical and Molecular Interventions.

PubMed

Kumar, Vinod; Singh, Brajesh Kumar; Chauhan, Amit Kumar; Singh, Deepali; Patel, Devendra Kumar; Singh, Chetna

2016-07-01

Accumulation of zinc (Zn) in dopaminergic neurons is implicated in Parkinson's disease (PD), and microglial activation plays a critical role in toxin-induced Parkinsonism. Oxidative stress is accused in Zn-induced dopaminergic neurodegeneration; however, its connection with microglial activation is still not known. This study was undertaken to elucidate the role and underlying mechanism of microglial activation in Zn-induced nigrostriatal dopaminergic neurodegeneration. Male Wistar rats were treated intraperitoneally with/without zinc sulphate (20 mg/kg) in the presence/absence of minocycline (30 mg/kg), a microglial activation inhibitor, for 2-12 weeks. While neurobehavioral and biochemical indexes of PD and number of dopaminergic neurons were reduced, the number of microglial cells was increased in the substantia nigra of the Zn-exposed animals. Similarly, Zn elevated lipid peroxidation (LPO) and activities of superoxide dismutase (SOD) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase; however, catalase activity was reduced. Besides, Zn increased an association of NADPH oxidase subunit p67(phox) with membrane, cytochrome c release from the mitochondria and cleavage of pro-caspase 3. Zn attenuated the expression of tyrosine hydroxylase (TH) and vesicular monoamine transporter-2 (VMAT-2) while augmented the expression of dopamine transporter (DAT) and heme oxygenase-1 (HO-1). Minocycline alleviated Zn-induced behavioural impairments, loss of TH-positive neurons, activated microglial cells and biochemical indexes and modulated the expression of studied genes/proteins towards normalcy. The results demonstrate that minocycline reduces the number of activated microglial cells and oxidative stress, which rescue from Zn-induced changes in the expression of monoamine transporter and nigrostriatal dopaminergic neurodegeneration.

Role of dietary sulphate in the regulation of methanogenesis in the human large intestine.

PubMed Central

Christl, S U; Gibson, G R; Cummings, J H

1992-01-01

Hydrogen produced during colonic fermentation may be excreted, or removed by H2 consuming bacteria such as methanogenic and sulphate reducing bacteria. In vitro, sulphate reducing bacteria compete with methanogenic bacteria for hydrogen when sulphate is present. In this study the hypothesis that sulphate in the diet could alter CH4 production in vivo has been tested. Six methane excreting volunteers were fed a low sulphate diet (1.6 mmol/d) for 34 days with the addition of 15 mmol sodium sulphate from days 11-20. Breath methane was measured and viable counts and metabolic activities of methanogenic bacteria and sulphate reducing bacteria determined in faeces. Whole gut transit time and daily stool weight were also measured. When sulphate was added to the diet, breath methane excretion decreased in three of the subjects while faecal sulphate reduction rates rose from 7.5 (0.5) to 20.3 (4.3) nmol SO4 reduced/h/g faeces. Sulphate reducing bacteria, which were not detected during the control diet, were found and viable counts of methanogenic bacteria fell from 10(7)-10(9)/g faeces to 10(6)/g. Methanogenic counts and breath CH4 recovered after sulphate addition was stopped. No change was found in the other three subjects. Faecal weights and transit times were not different between study periods. It is concluded that methanogenesis is regulated by dietary sulphate if sulphate reducing bacteria are present. Dietary sulphate may allow growth of sulphate reducing bacteria which inhibit the growth of methanogenic bacteria. This may explain the absence of CH4 in the breath of many people in western populations. PMID:1427377

Microwave assisted synthesis of bis and tris(ω-bromoacetophenones): versatile precursors for novel bis(imidazo[1,2-a]pyridines), bis(imidazo[1,2-a]pyrimidines) and their tris-analogs

PubMed Central

2013-01-01

Background α-Bromination of the side chain of aromatic ketones using NBS in the presence of p-toluenesulfonic acid (p-TsOH) in acetonitrile is very common. However, regioselective bromination of bis and tris(ω-bromoacetophenones) with NBS in the presence of p-TsOH in acetonitrile under microwave irradiation is quite novel. The bis- and tris(ω-bromoacetophenones) are used in synthesis of bis and tris(heterocycles). bis(heterocycles) have received a great deal of attention, because many biologically active natural and synthetic products have molecular symmetry. The use of the pressurized microwave irradiation is very advantageous to many syntheses and provide a large rate enhancement. Results Bis and tris(ω-bromoacetophenones) were obtained as single monobrominated derivatives in a shorter time than the conventional conditions. The results clearly demonstrate the better reactivity and selectivity of NBS/p-TsOH/CH3CN as a brominating mixture under microwave conditions. The reaction of bis and tris(ω-bromoacetophenone) with 2-aminopyridine and 2-aminopyrimidine proceeded smoothly in a mixture of anhydrous ethanol and DMF under reflux or using 300 W/105°C/ 20 min microwave irradiation conditions to afford the corresponding bis(imidazo[1,2-a]pyridine), bis(imidazo[1,2-a]pyrimidine) and tris(imidazo[1,2-a]pyridine) derivatives in moderate to excellent yields. The carbonyl analogue of the targeted bis(imidazopyridines) could be synthesized by the reaction of N,N-dimethyl-N'-(pyridin-2-yl)formimidamide with bis(ω-bromoacetophenone) in refluxing ethanol. The structures of the newly synthesized compounds were confirmed by their spectral data as well as their elemental analyses. Conclusion In conclusion, selective α-bromination of bis- and tris(acetophenones) has been accomplished efficiently utilizing NBS/p-TsOH/CH3CN under microwave irradiation. In addition, a facile synthesis of novel series of bis- and tris(imidazopyridine) and bis(imidazopyrimidine) derivatives. PMID:23782550

Semen coagulum liquefaction, sperm activation and cryopreservation of capuchin monkey (Cebus apella) semen in coconut water solution (CWS) and TES-TRIS.

PubMed

Oliveira, Karol G; Miranda, Stefania A; Leão, Danuza L; Brito, Adriel B; Santos, Regiane R; Domingues, Sheyla F S

2011-01-01

The objectives of the present study were to test the effect of coconut water solution and TES-TRIS on the seminal coagulum liquefaction, sperm activation in fresh diluted semen, and on the cryopreservation of semen from capuchin monkeys (Cebus apella). Semen was collected from six males by electro-ejaculation, diluted in TES-TRIS or coconut water solution (CWS), and incubated at 35°C until the coagulated fraction of the semen was completely liquefied. In the experiment I, after liquefaction, samples were diluted in TES-TRIS or CWS, plus 6 and 10mM/mL of caffeine. Sperm motility and vigor were evaluated during 5h. For experiment II, after liquefaction, semen samples were extended in TES-TRIS (3.5% glycerol in the final solution) or CWS (2.5% glycerol in the final solution), cryopreserved and stored in liquid nitrogen for 1 week. The seminal coagulum was liquefied in (mean±SDM) 4.5±1.7 and 2.8±1.1h in TES-TRIS and CWS, respectively. Sperm were motile in TES-TRIS and CWS for 5.0±1.4 and 1.0±0.5h, respectively. The mean motility in this period was 38±22% (TES-TRIS) and 22.0±16.0 (CWS). Motility increased after caffeine addition only in samples diluted in CWS containing 6mM (22.5±16.0) or 10mM (28.0±19.0) caffeine. Post-thaw live sperm percentage was 26.2% in TES-TRIS and 13.2% in CWS. For cryopreservation of semen from C. apella TES-TRIS (3.5% glycerol) was more appropriate than CWS (2.5% glycerol). CWS+caffeine potentially increase sperm motility and may be useful in artificial insemination of fresh diluted semen. Copyright © 2010 Elsevier B.V. All rights reserved.

Effects of Zinc Glycinate on Productive and Reproductive Performance, Zinc Concentration and Antioxidant Status in Broiler Breeders.

PubMed

Zhang, Ling; Wang, Yong-Xia; Xiao, Xue; Wang, Jiang-Shui; Wang, Qian; Li, Kai-Xuan; Guo, Tian-Yu; Zhan, Xiu-An

2017-08-01

An experiment was conducted to investigate the effects of zinc glycinate (Zn-Gly) supplementation as an alternative for zinc sulphate (ZnSO 4 ) on productive and reproductive performance, zinc (Zn) concentration and antioxidant status in broiler breeders. Six hundred 39-week-old Lingnan Yellow broiler breeders were randomly assigned to 6 groups consisting of 4 replicates with 25 birds each. Breeders were fed a basal diet (control group, 24 mg Zn/kg diet), basal diet supplemented with 80 mg Zn/kg diet from ZnSO 4 or basal diet supplemented with 20, 40, 60 and 80 mg Zn/kg diet from Zn-Gly. The experiment lasted for 8 weeks after a 4-week pre-test with the basal diet, respectively. Results showed that Zn supplementation, regardless of sources, improved (P < 0.05) the feed conversion ratio (kilogram of feed/kilogram of egg) and decreased broken egg rate, and elevated (P < 0.05) the qualified chick rate. Compared with the ZnSO 4 group, the 80 mg Zn/kg Zn-Gly group significantly increased (P < 0.05) average egg weight, fertility, hatchability and qualified chick rate, whereas it decreased (P < 0.05) broken egg rate. The Zn concentrations in liver and muscle were significantly higher (P < 0.05) in 80 mg Zn/kg Zn-Gly group than that in ZnSO 4 group. Compared with ZnSO 4 group, 80 mg Zn/kg Zn-Gly group significantly elevated (P < 0.05) the mRNA abundances of metallothionein (MT) and copper-zinc superoxide (Cu-Zn SOD), as well as the Cu-Zn SOD activity and MT concentration in liver. Moreover, the 80 mg Zn/kg Zn-Gly group had higher (P < 0.05) serum T-SOD and Cu-Zn SOD activities than that in the ZnSO 4 group. This study indicated that supplementation of Zn in basal diet improved productive and reproductive performance, Zn concentration and antioxidant status in broiler breeders, and the 80 mg Zn/kg from Zn-Gly was the optimum choice for broiler breeders compared with other levels of Zn from Zn-Gly and 80 mg/kg Zn from ZnSO 4 .

Hydrothermal synthesis of uniform WO{sub 3} submicrospheres using thiourea as an assistant agent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, X.T.; Xiao, F.; Lin, J.L.

2010-08-15

Nearly monodisperse tungsten trioxide submicrospheres have been synthesized with tungsten acid and HCl as the starting materials and thiourea as a structure-directing agent through a facile hydrothermal method. The obtained products were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy and energy dispersive X-ray, respectively. The results show that the WO{sub 3} submicrospheres are monodisperse with a diameter of about 800-1000 nm. The morphology of the products gradually evolutes from rods to spheres with increase of the reaction time. The formation mechanism of the WO{sub 3} submicrospheres is primarily discussed.

A Concise Synthesis of Presilphiperfolane Core through a Tandem TMTU-Co-Catalyzed Pauson-Khand Reaction and a 6π Electrocyclization Reaction (TMTU=Tetramethyl Thiourea).

PubMed

Zhang, Zichun; Li, Yuanhe; Zhao, Dandan; He, Yingdong; Gong, Jianxian; Yang, Zhen

2017-01-26

The synthesis of strained polycyclic systems from readily available precursors with a minimum number of steps and with regio- and stereochemical control constitutes an important synthetic challenge. Herein, we report a tandem reaction comprising Co-TMTU (tetramethyl thiourea)-catalyzed Pauson-Khand (PK) and 6π-electrocyclization reactions for the formation of the highly strained core of presilphiperfolanols. The developed chemistry has been applied to the total syntheses of 4-epi-presilphiperfolan-8-ol and 7-epi-presilphiperfolan-1-ol. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pharmacological evaluation of a novel series of urea, thiourea and guanidine derivatives as P2X7 receptor antagonists.

PubMed

Wong, Erick C N; Reekie, Tristan A; Werry, Eryn L; O'Brien-Brown, James; Bowyer, Sarah L; Kassiou, Michael

2017-06-01

We report on P2X 7 receptor antagonists based on a lead adamantly-cyanoguanidine-aryl moiety. We have investigated the importance of the central cyanoguanidine moiety by replacing it with urea, thiourea or guanidine moieties. We have also investigated the linker length between the central moiety and the aryl portion. All compounds were assessed for their inhibitory potency in a pore-formation dye uptake assay at the P2X 7 receptor. None of the compounds resulted in an improved potency illustrating the importance of the cyanoguanidine moiety in this chemotype. Copyright © 2017 Elsevier Ltd. All rights reserved.

A comparison of ultrasound-augmented and conventional leaching of silver from sintering dust using acidic thiourea.

PubMed

Chang, Jun; Zhang, Er-Dong; Zhang, Li-Bo; Peng, Jin-Hui; Zhou, Jun-Wen; Srinivasakannan, C; Yang, Chang-Jiang

2017-01-01

In the process of steel manufacture, up to ten millions of tons of sintering dust (SD) are produced annually in China, which contain noble metals such as Ag. Therefore, recovery of silver (Ag) from SD could be a potential economic and environmental activity. The purpose of this article is to generate information about reaction kinetics of silver leaching with thiourea from SD, comparing the conventional and ultrasonic-augment leaching. The effects of various control parameters such as the ultrasound power, particle size, leaching temperature and thiourea concentration on leaching rate of silver were studied. The results showed 89% silver recovery for conventional process against 95% for ultrasound assisted leaching. The ultrasonic wave increased the leaching rate and shorten the reaction time. The rate controlling step was analyzed using shrinking core model and the rate controlling step is identified to be the diffusion through the product layer in both conventional and ultrasonic-augment leaching processes. The activation energies were estimated to be 28.01kJ/mol and 18.19kJ/mol, and the reaction order were 0.89 and 0.71, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Derived and thiourea-functionalized silica for cadmium removal: isotherm, kinetic and thermodynamic studies

NASA Astrophysics Data System (ADS)

Omotunde, Iyanu; Okoronkwo, Afamefuna; Oluwashina, Olugbenga

2018-03-01

The present study explored the feasibility of using derived and thiourea-functionalized silica as adsorbent for the removal of cadmium under different experimental conditions. Effects of various parameters such as function of point of zero charge (pHPZC), solution pH, sorbent-sorbate resident time and ratio, concentration and temperature were investigated. The sorption of cadmium followed the pseudo-second-order rate kinetics. Thermodynamic studies revealed that the sorption of cadmium was endothermic and spontaneous, with good affinity toward the sorbent. Various isotherm models, viz. Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Harkins-Jura, and Halsey isotherms were used to analyze the equilibrium data at different temperatures. The Freundlich, Halsey, Langmuir, and Temkin models were found to be in good agreement with the experimental data with high R 2, low RMSE, and low χ 2 values. The results show that the sorption capacity increases with an increase in solution temperature from 28 to 65 °C. The maximum sorption capacity calculated from Langmuir isotherm was 27.55 and 28.41 mg g-1 for derived and thiourea-functionalized silica, respectively, at optimum condition of pH 5 and contact time of 120 min.

Disubstituted thiourea derivatives and their activity on CNS: synthesis and biological evaluation.

PubMed

Stefanska, Joanna; Szulczyk, Daniel; Koziol, Anna E; Miroslaw, Barbara; Kedzierska, Ewa; Fidecka, Sylwia; Busonera, Bernardetta; Sanna, Giuseppina; Giliberti, Gabriele; La Colla, Paolo; Struga, Marta

2012-09-01

A series of new thiourea derivatives of 1,2,4-triazole have been synthesized. The difference in structures of obtained compounds are directly connected with the kind of isothiocyanate (aryl/alkyl). The (1)H NMR, (13)C NMR, MS methods were used to confirm structures of obtained thiourea derivatives. The molecular structure of (1, 17) was determined by an X-ray analysis. Two of the new compounds (8 and 14) were tested for their pharmacological activity on animal central nervous system (CNS) in behavioural animal tests. The results presented in this work indicate the possible involvement of the serotonergic system in the activity of 8 and 14. In the case of 14 is also a possible link between its activity and the endogenous opioid system. All obtained compounds were tested for antibacterial activity against gram-positive cocci, gram-negative rods and antifungal activity. Compounds (1, 2, 5, 7, 9) showed significant inhibition against gram-positive cocci. Microbiological evaluation was carried out over 20 standard strains and 30 hospital strains. Selected compounds (1-13) were examined for cytotoxicity, antitumor, and anti-HIV activity. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

A novel synthetic 1,3-phenyl bis-thiourea compound targets microtubule polymerization to cause cancer cell death

PubMed Central

Shing, Jennifer C; Choi, Jae Won; Chapman, Robert; Schroeder, Mark A; Sarkaria, Jann N; Fauq, Abdul; Bram, Richard J

2014-01-01

Microtubules are essential cytoskeletal components with a central role in mitosis and have been particularly useful as a cancer chemotherapy target. We synthesized a small molecule derivative of a symmetrical 1,3-phenyl bis-thiourea, (1,1'-[1,3-phenylene]bis[3-(3,5-dimethylphenyl)thiourea], named “41J”), and identified a potent effect of the compound on cancer cell survival. 41J is cytotoxic to multiple cancer cell lines at nanomolar concentrations. Cell death occurred by apoptosis and was preceded by mitotic arrest in prometaphase. Prometaphase arrest induced by 41J treatment was accompanied by dissociation of cyclin B1 levels from the apparent mitotic stage and by major spindle abnormalities. Polymerization of purified tubulin in vitro was directly inhibited by 41J, suggesting that the compound works by directly interfering with microtubule function. Compound 41J arrested the growth of glioblastoma multiforme xenografts in nude mice at doses that were well-tolerated, demonstrating a relatively specific antitumor effect. Importantly, 41J overcame drug resistance due to β-tubulin mutation and P-glycoprotein overexpression. Compound 41J may serve as a useful new lead compound for anticancer therapy development. PMID:24755487

Rapid sequential determination of arsenic and selenium in waters and plant digests by hydride generation inductively coupled plasma-mass spectrometry

NASA Astrophysics Data System (ADS)

Menegário, Amauri A.; Giné, Maria Fernanda

2000-04-01

A synchronised flow system with hydride generation coupled to ICP-MS is proposed for the sequential determination of As and Se in natural waters and plant digests. The alternated mixing of the sample solution with thiourea or HCl for the determination of As or Se under optimized conditions was achieved using a flow commutator before the reaction with NaBH 4. The on-line addition of thiourea promoted the quantitative reduction of As(V) to As(III), thus enhancing sensitivity and precision. The selenium pre-reduction from Se(VI) to Se(IV) was produced by heating the sample with HCl, and the hydride generation was performed in 4 mol l -1 HCl, thus avoiding interference from thiourea. The system allowed the analysis of 20 samples h -1 with LOD values of 0.02 μg l -1 As and 0.03 μg l -1 Se. Results were in agreement with the certified values at the 95% confidence level for reference waters from the Canadian National Water Research Institute and plant samples from the National Institute of Standards and Technology (NIST).

Design, synthesis and biological evaluation of novel HSP70 inhibitors: N, N'-disubstituted thiourea derivatives.

PubMed

Zeng, Yan-Qun; Cao, Rui-Yuan; Yang, Jian-Ling; Li, Xing-Zhou; Li, Song; Zhong, Wu

2016-08-25

As novel heat shock protein 70 (HSP70) inhibitors, N, N'-disubstituted thiourea derivatives were designed and synthesized based on the X-ray structure of the ATPase domain (nucleotide binding domain, NBD). An ATPase activity inhibition assay revealed that these compounds effectively inhibited HSP70 ATPase activity. The results revealed that the compounds 370/371/374/379/380//392/394/397/404/405 and 407 can inhibit the HSP70 ATPase turnover with high percentages of inhibition: 50.42, 38.46, 50.45, 44.12, 47.13, 50.50, 40.95, 65.36, 46.23, 35.78, and 58.37 in 200 μM, respectively. Significant synergies with lapatinib were observed for compound 379 and compound 405 in the BT474 breast cancer cell line. A structure-function analysis revealed that most of the thiourea derivatives exhibited cooperative action with lapatinib in the BT474 cancer cell line and the BT/Lap(R)1.0 lapatinib-resistant cell line. HSP70 inhibitors may be developed as synergetic drugs in drug-resistant cancer therapy. Copyright © 2016 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

Structural, antimicrobial and computational characterization of 1-benzoyl-3-(5-chloro-2-hydroxyphenyl)thiourea.

PubMed

Atiş, Murat; Karipcin, Fatma; Sarıboğa, Bahtiyar; Taş, Murat; Çelik, Hasan

2012-12-01

A new thiourea derivative, 1-benzoyl-3-(5-chloro-2-hydroxyphenyl)thiourea (bcht) has been synthesized from the reaction of 2-amino-4-chlorophenol with benzoyl isothiocyanate. The title compound has been characterized by elemental analyses, FT-IR, (13)C, (1)H NMR spectroscopy and the single crystal X-ray diffraction analysis. The structure of bcht derived from X-ray diffraction of a single crystal has been presented. The structural and spectroscopic data of the molecule in the ground state were calculated by using density functional method using 6-311++G(d,p) basis set. The complete assignments of all vibrational modes were performed on the basis of the total energy distributions (TED). Isotropic chemical shifts ((13)C NMR and (1)H NMR) were calculated using the gauge-invariant atomic orbital (GIAO) method. Theoretical calculations of bond parameters, harmonic vibration frequencies and nuclear magnetic resonance are in good agreement with experimental results. The UV absorption spectra of the compound that dissolved in ACN and MeOH were recorded. Bcht was also screened for antimicrobial activity against pathogenic bacteria and fungi. Copyright © 2012 Elsevier B.V. All rights reserved.

Production of .sup.203 Pb-tris-hydroxymethyl amino methane

DOEpatents

Lambrecht, Richard M.; Packer, Samuel; Merrill, Jerald C.; Atkins, Harold L.; Wolf, Alfred P.; Bradley-Moore, Patrick R.

1977-01-01

.sup.203 Pb-tris complex injected for use in the detection and localization of tumors. The lead-203 is produced from the deuteron bombardment of a thallium target and chemically separated from the thallium. The tris is added which complexes with the lead-203.

Mass Spectrometry Based Mechanistic Insights into Formation of Tris Conjugates: Implications on Protein Biopharmaceutics

NASA Astrophysics Data System (ADS)

Kabadi, Pradeep G.; Sankaran, Praveen Kallamvalliillam; Palanivelu, Dinesh V.; Adhikary, Laxmi; Khedkar, Anand; Chatterjee, Amarnath

2016-10-01

We present here extensive mass spectrometric studies on the formation of a Tris conjugate with a therapeutic monoclonal antibody. The results not only demonstrate the reactive nature of the Tris molecule but also the sequence and reaction conditions that trigger this reactivity. The results corroborate the fact that proteins are, in general, prone to conjugation and/or adduct formation reactions and any modification due to this essentially leads to formation of impurities in a protein sample. Further, the results demonstrate that the conjugation reaction happens via a succinimide intermediate and has sequence specificity. Additionally, the data presented in this study also shows that the Tris formation is produced in-solution and is not an in-source phenomenon. We believe that the facts given here will open further avenues on exploration of Tris as a conjugating agent as well as ensure that the use of Tris or any ionic buffer in the process of producing a biopharmaceutical drug is monitored closely for the presence of such conjugate formation.

Cross-linkable graphene oxide embedded nanocomposite hydrogel with enhanced mechanics and cytocompatibility for tissue engineering.

PubMed

Liu, Xifeng; Miller, A Lee; Waletzki, Brian E; Lu, Lichun

2018-05-01

Graphene oxide (GO) is an attractive material that can be utilized to enhance the modulus and conductivities of substrates and hydrogels. To covalently cross-link graphene oxide sheets into hydrogels, abundant cross-linkable double bonds were introduced to synthesize the graphene-oxide-tris-acrylate sheet (GO-TrisA). Polyacrylamide (PAM) nanocomposite hydrogels were then fabricated with inherent covalently and permanently cross-linked GO-TrisA sheets. Results showed that the covalently cross-linked GO-TrisA/PAM nanocomposite hydrogel had enhanced mechanical strength, thermo stability compared with GO/PAM hydrogel maintained mainly by hydrogen bonding between PAM chains and GO sheets. In vitro cell study showed that the covalently cross-linked rGO-TrisA/PAM nanocomposite hydrogel had excellent cytocompatibility after in situ reduction. These results suggest that rGO-TrisA/PAM nanocomposite hydrogel holds great potential for tissue engineering applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1247-1257, 2018. © 2018 Wiley Periodicals, Inc.

The mode of action of 4-methylumbelliferyl β-d-xyloside on the synthesis of chondroitin sulphate in embryonic-chicken sternum

PubMed Central

Gibson, Kenneth D.; Segen, Barbara J.

1977-01-01

1. Embryonic-chicken sterna, incubated in medium containing 0.1mm-4-methylumbelliferyl β-d-xyloside (4-methylcoumarin 7-β-d-xyloside), synthesize proteochondroitin sulphate that is significantly undersulphated and shorter than usual [Gibson, Segen & Audhya (1977) Biochem. J. 162, 217–233]. 2. Neither the β-d-galactoside nor the β-d-glucuronide of 4-methylumbelliferone, nor 4-methylumbelliferone itself, produced the effects. The only metabolites of 4-methylumbelliferone that were detected in cartilages exposed to 4-methylumbelliferyl β-d-xyloside were unchanged xyloside and chondroitin sulphate covalently attached to 4-methylumbelliferone. 3. Gel filtration of salt extracts of sterna incubated in medium containing the xyloside showed that there were two pools of chondroitin sulphate in the tissue. One pool was identified, on the basis of its elution pattern and the linear kinetics of incorporation of sulphate into it, as proteochondroitin sulphate. Incorporation into the other pool, whose properties suggested that it was methylumbelliferyl-chondroitin sulphate, indicated that it underwent partial turnover. The molecular weight of this chondroitin sulphate was about 19000, and it appeared to be about 70% sulphated. 4. When sterna were incubated in medium containing the xyloside, there was a very large incorporation of sulphate and glucose into glycosaminoglycans that were released into the incubation medium. This contrasts with incubations of sterna in the absence of the xyloside, in which less than 5% of the sulphate incorporated could be recovered from the medium. The glycosaminoglycan released into the medium was 4-methylumbelliferyl-chondroitin sulphate, whose average molecular weight was 7000–8000 and degree of sulphation more than 95%. 5. Incorporation of sulphate into proteochondroitin sulphate was stimulated more than 3-fold by addition of 20% (v/v) human serum and 10nm-l-3,3′,5-tri-iodothyronine. Incorporation into methylumbelliferyl-chondroitin sulphate, in either the tissue or the medium, was not significantly altered. 6. The decrease in chain length and degree of sulphation of proteochondroitin sulphate is explained in terms of competition between peptide-linked primers and methylumbelliferone-containing primers at the intracellular sites of polysaccharidechain elongation and sulphation. The implications of the results for the mechanism of stimulation of proteoglycan synthesis by serum factors are discussed. PMID:597264

DEVELOPMENT OF A SMALL CHAMBER METHOD FOR SVOC SINK EFFECT STUDY

EPA Science Inventory

This paper describes the details of the improved chamber system and reports the sink effect study for organophosphorus flame retardants (OP-FRs), including tris(2-chloroethyl) phosphate(TCEP), tris(1-chlor-2-propyl) phosphate (TCPP) and tris(1,3-dichloro-2-propyl) phosphate (TDC...

Synthesis and structural characterization of Co2+ ions doped ZnO nanopowders by solid state reaction through sonication

NASA Astrophysics Data System (ADS)

Babu, B.; Rama Krishna, Ch.; Venkata Reddy, Ch.; Pushpa Manjari, V.; Ravikumar, R. V. S. S. N.

2013-05-01

Cobalt ions doped zinc oxide nanopowder was prepared at room temperature by a novel and simple one step solid-state reaction method through sonication in the presence of a suitable surfactant Sodium Lauryl Sulphate (SLS). The prepared powder was characterized by various spectroscopic techniques. Powder XRD data revealed that the crystal structure belongs to hexagonal and its average crystallite size was evaluated. From optical absorption data, crystal fields (Dq), inter-electronic repulsion parameters (B, C) were evaluated. By correlating optical and EPR spectral data, the site symmetry of Co2+ ion in the host lattice was determined as octahedral. Photoluminescence spectra exhibited the emission bands in ultraviolet and blue regions. The CIE chromaticity coordinates are also evaluated from the emission spectrum. FT-IR spectra showed the characteristic vibrational bands of Znsbnd O.

Optimised deconjugation of androgenic steroid conjugates in bovine urine.

PubMed

Pedersen, Mikael; Frandsen, Henrik L; Andersen, Jens H

2017-04-01

After administration of steroids to animals the steroids are partially metabolised in the liver and kidney to phase 2 metabolites, i.e., glucuronic acid or sulphate conjugates. During analysis these conjugated metabolites are normally deconjugated enzymatically with aryl sulphatase and glucuronidase resulting in free steroids in the extract. It is well known that some sulphates are not deconjugated using aryl sulphatase; instead, for example, solvolysis can be used for deconjugation of these aliphatic sulphates. The effectiveness of solvolysis on androgenic steroid sulphates was tested with selected aliphatic steroid sulphates (boldenone sulphate, nortestosteron sulphate and testosterone sulphate), and the method was validated for analysis of androgenic steroids in bovine urine using free steroids, steroid sulphates and steroid glucuronides as standards. Glucuronidase and sulphuric acid in ethyl acetate were used for deconjugation and the extract was purified by solid-phase extraction. The final extract was evaporated to dryness, re-dissolved and analysed by LC-MS/MS.

Comparison of Air Sampling Methods for Organophosphate Flame Retardants in Small Environmental Chambers

EPA Science Inventory

Organophosphorus flame retardants (OPFRs), such as tris(2-chloroethyl) phosphate (TCEP), tris(1-chlor-2-propyl) phosphate (TCPP), and tris(1,3-dichloro-2-propyl) phosphate (TDCPP), used as additives in industrial and consumer products are being detected in indoor air, house dust,...

Intramolecular aggregation and optical limiting properties of triazine-linked mono-, bis- and tris-phthalocyanines.

PubMed

Chen, Jun; Zhang, Tao; Wang, Shuangqing; Hu, Rui; Li, Shayu; Ma, Jin Shi; Yang, Guoqiang

2015-10-05

A series of triazine-linked mono-, bis- and tris-phthalocyanines are synthesized, intramolecular aggregation is found in bis- and tris-phthalocyanines via π-π stacking interaction. Theoretical and experimental studies reveal the formation of the intramolecular aggregation. The spectrographic, photophysical and nonlinear optical properties of these compounds are adjusted for the formation of the intramolecular aggregation. The bis-phthalocyanine dimer presents smaller fluorescence quantum yield, lower triplet formation yield and the triplet-minus-ground state extinction coefficient, which causes poorer optical limiting performance. It is interesting that the tris-phthalocyanine is composed of a mono-phthalocyanine part and a bis-phthalocyanine part, the optical limiting property of the tris-phthalocyanine is similar to that of mono-phthalocyanine. Copyright © 2015 Elsevier B.V. All rights reserved.

Physicochemical and in vitro deposition properties of salbutamol sulphate/ipratropium bromide and salbutamol sulphate/excipient spray dried mixtures for use in dry powder inhalers.

PubMed

Corrigan, Deirdre O; Corrigan, Owen I; Healy, Anne Marie

2006-09-28

The physicochemical and aerodynamic properties of spray dried powders of the drug/drug mixture salbutamol sulphate/ipratropium bromide were investigated. The in vitro deposition properties of spray dried salbutamol sulphate and the spray dried drug/excipient mixtures salbutamol sulphate/lactose and salbutamol sulphate/PEG were also determined. Spray drying ipratropium bromide monohydrate resulted in a crystalline material from both aqueous and ethanolic solution. The product spray dried from aqueous solution consisted mainly of ipratropium bromide anhydrous. There was evidence of the presence of another polymorphic form of ipratropium bromide. When spray dried from ethanolic solution the physicochemical characterisation suggested the presence of an ipratropium bromide solvate with some anhydrous ipratropium bromide. Co-spray drying salbutamol sulphate with ipratropium bromide resulted in amorphous composites, regardless of solvent used. Particles were spherical and of a size suitable for inhalation. Twin impinger studies showed an increase in the fine particle fraction (FPF) of spray dried salbutamol sulphate compared to micronised salbutamol sulphate. Co-spray dried salbutamol sulphate:ipratropium bromide 10:1 and 5:1 systems also showed an increase in FPF compared to micronised salbutamol sulphate. Most co-spray dried salbutamol sulphate/excipient systems investigated demonstrated FPFs greater than that of micronised drug alone. The exceptions to this were systems containing PEG 4000 20% or PEG 20,000 40% both of which had FPFs not significantly different from micronised salbutamol sulphate. These two systems were crystalline unlike most of the other spray dried composites examined which were amorphous in nature.

40 CFR 721.10688 - Copper, chloro[tris(2-chloroethyl) phosphite-.kappa.P]-.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) phosphite-.kappa.P]-. 721.10688 Section 721.10688 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10688 Copper, chloro[tris(2-chloroethyl) phosphite-.kappa.P]-. (a... copper, chloro[tris(2-chloroethyl) phosphite-.kappa.P]- (PMN P-13-221; CAS No. 24484-01-3) is subject to...

ssDNA degradation along capillary electrophoresis process using a Tris buffer.

PubMed

Ric, Audrey; Ong-Meang, Varravaddheay; Poinsot, Verena; Martins-Froment, Nathalie; Chauvet, Fabien; Boutonnet, Audrey; Ginot, Frédéric; Ecochard, Vincent; Paquereau, Laurent; Couderc, François

2017-06-01

Tris-Acetate buffer is currently used in the selection and the characterization of ssDNA by capillary electrophoresis (CE). By applying high voltage, the migration of ionic species into the capillary generates a current that induces water electrolysis. This phenomenon is followed by the modification of the pH and the production of Tris derivatives. By injecting ten times by capillary electrophoresis ssDNA (50 nM), the whole oligonucleotide was degraded. In this paper, we will show that the Tris buffer in the running vials is modified along the electrophoretic process by electrochemical reactions. We also observed that the composition of the metal ions changes in the running buffer vials. This phenomenon, never described in CE, is important for fluorescent ssDNA analysis using Tris buffer. The oligonucleotides are degraded by electrochemically synthesized species (present in the running Tris vials) until it disappears, even if the separation buffer in the capillary is clean. To address these issues, we propose to use a sodium phosphate buffer that we demonstrate to be electrochemically inactive. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of chemical availability of cadmium and zinc in soils using inert soil moisture samplers.

PubMed

Knight, B P; Chaudri, A M; McGrath, S P; Giller, K E

1998-01-01

A rapid method for extracting soil solutions using porous plastic soil-moisture samplers was combined with a cation resin equilibration based speciation technique to look at the chemical availability of metals in soil. Industrially polluted, metal sulphate amended and sewage sludge treated soils were used in our study. Cadmium sulphate amended and industrially contaminated soils all had > 65% of the total soil solution Cd present as free Cd2+. However, increasing total soil Cd concentrations by adding CdSO4 resulted in smaller total soil solution Cd. Consequently, the free Cd2+ concentrations in soil solutions extracted from these soils were smaller than in the same soil contaminated by sewage sludge addition. Amendment with ZnSO4 gave much greater concentrations of free Zn2+ in soil solutions compared with the same soil after long-term Zn contamination via sewage sludge additions. Our results demonstrate the difficulty in comparing total soil solution and free metal ion concentrations for soils from different areas with different physiochemical properties and sources of contamination. However, when comparing the same Woburn soil, Cd was much less available as Cd2+ in soil solution from the CdSO4 amended soils compared with soil contaminated by about 36 years of sewage sludge additions. In contrast, much more Zn was available in soil solution as free Zn2+ in the ZnSO4 amended soils compared with the sewage sludge treated soils.

Mycoremediation of congo red dye by filamentous fungi.

PubMed

Bhattacharya, Sourav; Das, Arijit; G, Mangai; K, Vignesh; J, Sangeetha

2011-10-01

Azo, anthroquinone and triphenylmethane dyes are the major classes of synthetic colourants, which are difficult to degrade and have received considerable attention. Congo red, a diazo dye, is considered as a xenobiotic compound, and is recalcitrant to biodegradative processes. Nevertheless, during the last few years it has been demonstrated that several fungi, under certain environmental conditions, are able to transfer azo dyes to non toxic products using laccases. The aim of this work was to study the factors influencing mycoremediation of Congo red. Several basidiomycetes and deuteromycetes species were tested for the decolourisation of Congo red (0.05 g/l) in a semi synthetic broth at static and shaking conditions. Poor decolourisation was observed when the dye acted as the sole source of nitrogen, whereas semi synthetic broth supplemented with fertilizer resulted in better decolourisation. Decolourisation of Congo red was checked in the presence of salts of heavy metals such as mercuric chloride, lead acetate and zinc sulphate. Decolourisation parameters such as temperature, pH, and rpm were optimized and the decolourisation obtained at optimized conditions varied between 29.25- 97.28% at static condition and 82.1- 100% at shaking condition. Sodium dodecyl sulphate polyacrylamide gel electrophoretic analysis revealed bands with molecular weights ranging between 66.5 to 71 kDa, a characteristic of the fungal laccases. High efficiency decolourisation of Congo red makes these fungal forms a promising choice in biological treatment of waste water containing Congo red.

Combined strong anion-exchange HPLC and PAGE approach for the purification of heparan sulphate oligosaccharides.

PubMed

Vivès, R R; Goodger, S; Pye, D A

2001-02-15

Heparan sulphates are highly sulphated linear polysaccharides involved in many cellular functions. Their biological properties stem from their ability to interact with a wide range of proteins. An increasing number of studies, using heparan sulphate-derived oligosaccharides, suggest that specific structural features within the polysaccharide are responsible for ligand recognition and regulation. In the present study, we show that strong anion-exchange HPLC alone, a commonly used technique for purification of heparan sulphate-derived oligosaccharides, may not permit the isolation of highly pure heparan sulphate oligosaccharide species. This was determined by PAGE analysis of hexa-, octa- and decasaccharide samples deemed to be pure by strong anion-exchange HPLC. In addition, subtle differences in the positioning of sulphate groups within heparan sulphate hexasaccharides were impossible to detect by strong anion-exchange HPLC. PAGE analysis on the other hand afforded excellent resolution of these structural isomers. The precise positioning of specific sulphate groups has been implicated in determining the specificity of heparan sulphate interactions and biological activities; hence, the purification of oligosaccharide species that differ in this way becomes an important issue. In this study, we have used strong anion-exchange HPLC and PAGE techniques to allow production of the homogeneous heparan sulphate oligosaccharide species that will be required for the detailed study of structure/activity relationships.

Investigation of Structure and Reactivity Relationship in M-N-C Type Catalysts using Density Functional Tight Binding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Negre, Christian Francisco Andres; Gonzales, Ivana

Catalysts inhibition studies were performed to indisputably confirm the role of various metal, carbon, and nitrogen moieties in the individual steps of oxygen reduction reaction (ORR) on M-N-C catalysts. ORR activity was studied at University of New Mexico by rotating ring disk electrode method in the acidic electrolyte with the addition of Tris (tris(hydroxymethyl)-aminomethane) as inhibiting agent. To understand the interaction of Tris with different defects that exist in Fe-N-C materials and provide the support for the experimental data, we used density functional theory (DFT) and modeled the interaction of protonated Tris (TrisH) with Fe containingcenters (Fe-N 4 and Fe-Nmore » 2C 2), pyridinic nitrogen, graphitic nitrogen, and pyrrolic nitrogen both as in plane and edge defects.« less

Design, synthesis and biological evaluation of di-substituted cinnamic hydroxamic acids bearing urea/thiourea unit as potent histone deacetylase inhibitors.

PubMed

Ning, Chengqing; Bi, Yanjing; He, Yujun; Huang, WenYuan; Liu, Lifei; Li, Yi; Zhang, Sihan; Liu, Xiaoyu; Yu, Niefang

2013-12-01

A novel class of di-substituted cinnamic hydroxamic acid derivatives containing urea or thiourea unit was designed, synthesized and evaluated as HDAC inhibitors. All tested compounds demonstrated significant HDAC inhibitory activities and anti-proliferative effects against diverse human tumor cell lines. Among them, 7l exhibited most potent pan-HDAC inhibitory activity, with an IC50 value of 130 nM. It also showed strong cellular inhibition against diverse cell lines including HCT-116, MCF-7, MDB-MB-435 and NCI-460, with GI50 values of 0.35, 0.22, 0.51 and 0.48 μM, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Synthesis of chiral pyrazolo[4,3-e][1,2,4]triazine sulfonamides with tyrosinase and urease inhibitory activity.

PubMed

Mojzych, Mariusz; Tarasiuk, Paweł; Kotwica-Mojzych, Katarzyna; Rafiq, Muhammad; Seo, Sung-Yum; Nicewicz, Michał; Fornal, Emilia

2017-12-01

A new series of sulfonamide derivatives of pyrazolo[4,3-e][1,2,4]triazine with chiral amino group has been synthesized and characterized. The compounds were tested for their tyrosinase and urease inhibitory activity. Evaluation of prepared derivatives demonstrated that compounds (8b) and (8j) are most potent mushroom tyrosinase inhibitors whereas all of the obtained compounds showed higher urease inhibitory activity than the standard thiourea. The compounds (8a), (8f) and (8i) exhibited excellent enzyme inhibitory activity with IC 50 0.037, 0.044 and 0.042 μM, respectively, while IC 50 of thiourea is 20.9 μM.

Balance the Carrier Mobility To Achieve High Performance Exciplex OLED Using a Triazine-Based Acceptor.

PubMed

Hung, Wen-Yi; Chiang, Pin-Yi; Lin, Shih-Wei; Tang, Wei-Chieh; Chen, Yi-Ting; Liu, Shih-Hung; Chou, Pi-Tai; Hung, Yi-Tzu; Wong, Ken-Tsung

2016-02-01

A star-shaped 1,3,5-triazine/cyano hybrid molecule CN-T2T was designed and synthesized as a new electron acceptor for efficient exciplex-based OLED emitter by mixing with a suitable electron donor (Tris-PCz). The CN-T2T/Tris-PCz exciplex emission shows a high ΦPL of 0.53 and a small ΔET-S = -0.59 kcal/mol, affording intrinsically efficient fluorescence and highly efficient exciton up-conversion. The large energy level offsets between Tris-PCz and CN-T2T and the balanced hole and electron mobility of Tris-PCz and CN-T2T, respectively, ensuring sufficient carrier density accumulated in the interface for efficient generation of exciplex excitons. Employing a facile device structure composed as ITO/4% ReO3:Tris-PCz (60 nm)/Tris-PCz (15 nm)/Tris-PCz:CN-T2T(1:1) (25 nm)/CN-T2T (50 nm)/Liq (0.5 nm)/Al (100 nm), in which the electron-hole capture is efficient without additional carrier injection barrier from donor (or acceptor) molecule and carriers mobilities are balanced in the emitting layer, leads to a highly efficient green exciplex OLED with external quantum efficiency (EQE) of 11.9%. The obtained EQE is 18% higher than that of a comparison device using an exciplex exhibiting a comparable ΦPL (0.50), in which TCTA shows similar energy levels but higher hole mobility as compared with Tris-PCz. Our results clearly indicate the significance of mobility balance in governing the efficiency of exciplex-based OLED. Exploiting the Tris-PCz:CN-T2T exciplex as the host, we further demonstrated highly efficient yellow and red fluorescent OLEDs by doping 1 wt % Rubrene and DCJTB as emitter, achieving high EQE of 6.9 and 9.7%, respectively.

Tris-borate is a poor counterion for RNA: a cautionary tale for RNA folding studies

PubMed Central

Buchmueller, Karen L.; Weeks, Kevin M.

2004-01-01

Native polyacrylamide gel electrophoresis is a powerful approach for visualizing RNA folding states and folding intermediates. Tris-borate has a high-buffering capacity and is therefore widely used in electrophoresis-based investigations of RNA structure and folding. However, the effectiveness of Tris-borate as a counterion for RNA has not been systematically investigated. In a recirculated Hepes/KCl buffer, the catalytic core of the bI5 group I intron RNA undergoes a conformational collapse characterized by a bulk transition midpoint, or Mg1/2, of ∼3 mM, consistent with extensive independent biochemical experiments. In contrast, in Tris-borate, RNA collapse has a much smaller apparent Mg1/2, equal to 0.1 mM, because in this buffer the RNA undergoes a different, large amplitude, folding transition at low Mg2+ concentrations. Analysis of structural neighbors using a short-lived, RNA-tethered, photocrosslinker indicates that the global RNA structure eventually converges in the two buffer systems, as the divalent ion concentration approaches ∼1 mM Mg2+. The weak capacity of Tris-borate to stabilize RNA folding may reflect relatively unfavorable interactions between the bulky Tris-borate ion and RNA or partial coordination of RNA functional groups by borate. Under some conditions, Tris-borate is a poor counterion for RNA and its use merits careful evaluation in RNA folding studies. PMID:15601995

Binding of endostatin to endothelial heparan sulphate shows a differential requirement for specific sulphates.

PubMed

Blackhall, Fiona H; Merry, Catherine L R; Lyon, Malcolm; Jayson, Gordon C; Folkman, Judah; Javaherian, Kashi; Gallagher, John T

2003-10-01

Endostatin is a naturally occurring proteolytic fragment of the C-terminal domain of collagen XVIII. It inhibits angiogenesis by a mechanism that appears to involve binding to HS (heparan sulphate). We have examined the molecular interaction between endostatin and HS from micro- and macrovessel endothelial cells. Two discrete panels of oligosaccharides were prepared from metabolically radiolabelled HS, using digestion with either heparinase I or III, and then examined for their endostatin affinity using a sensitive filter-binding assay. Two types of endostatin-binding regions were identified: one comprising sulphated domains of five or more disaccharides in length, enriched in 6-O-sulphate groups, and the other contained long heparinase I-resistant fragments. In the latter case, evidence from the present study suggests that the binding region encompasses a sulphated domain fragment and a transition zone of intermediate sulphation. The contribution to binding of specific O-sulphate groups was determined using selectively desulphated HS species, namely HS from Hs2st-/- mutant cells, and by comparing the compositions of endostatin-binding and non-binding oligosaccharides. The results indicate that 6-O-sulphates play a dominant role in site selectivity and 2-O-sulphates are not strictly essential.

Binding of endostatin to endothelial heparan sulphate shows a differential requirement for specific sulphates.

PubMed Central

Blackhall, Fiona H; Merry, Catherine L R; Lyon, Malcolm; Jayson, Gordon C; Folkman, Judah; Javaherian, Kashi; Gallagher, John T

2003-01-01

Endostatin is a naturally occurring proteolytic fragment of the C-terminal domain of collagen XVIII. It inhibits angiogenesis by a mechanism that appears to involve binding to HS (heparan sulphate). We have examined the molecular interaction between endostatin and HS from micro- and macrovessel endothelial cells. Two discrete panels of oligosaccharides were prepared from metabolically radiolabelled HS, using digestion with either heparinase I or III, and then examined for their endostatin affinity using a sensitive filter-binding assay. Two types of endostatin-binding regions were identified: one comprising sulphated domains of five or more disaccharides in length, enriched in 6-O-sulphate groups, and the other contained long heparinase I-resistant fragments. In the latter case, evidence from the present study suggests that the binding region encompasses a sulphated domain fragment and a transition zone of intermediate sulphation. The contribution to binding of specific O-sulphate groups was determined using selectively desulphated HS species, namely HS from Hs2st-/- mutant cells, and by comparing the compositions of endostatin-binding and non-binding oligosaccharides. The results indicate that 6-O-sulphates play a dominant role in site selectivity and 2-O-sulphates are not strictly essential. PMID:12812520

An unusual photosensitizer: dyad of eosin-tris(2,2'-bipyridine)Ru(II).

PubMed

Jing, Bingwen; Zhang, Manhua; Shen, Tao

2003-10-02

[structure: see text] A dyad of eosin and tris(2,2'-bipyridine)Ru(II) was prepared, and its photophysical properties were investigated. The photosensitization of eosin is greatly enhanced by introduction of tris(2,2'-bipyridine)Ru(II), which is verified via photooxygenation of anthracene derivatives. The electron-transfer mechanism of photosensitization is also discussed.

40 CFR 721.1880 - Borate(1-), tris(acetato-.kappa.O)hydro-, sodium, (T-4)-.

Code of Federal Regulations, 2010 CFR

2010-07-01

...)hydro-, sodium, (T-4)-. 721.1880 Section 721.1880 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.1880 Borate(1-), tris(acetato-.kappa.O)hydro-, sodium... substance identified as borate(1-), tris(acetato-.kappa.O)hydro-, sodium, (T-4)- (PMN P-00-0922; CAS No...

40 CFR 721.1880 - Borate(1-), tris(acetato-.kappa.O)hydro-, sodium, (T-4)-.

Code of Federal Regulations, 2011 CFR

2011-07-01

...)hydro-, sodium, (T-4)-. 721.1880 Section 721.1880 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.1880 Borate(1-), tris(acetato-.kappa.O)hydro-, sodium... substance identified as borate(1-), tris(acetato-.kappa.O)hydro-, sodium, (T-4)- (PMN P-00-0922; CAS No...

Synthesis and characterization of Zn(O,OH)S and AgInS2 layers to be used in thin film solar cells

NASA Astrophysics Data System (ADS)

Vallejo, W.; Arredondo, C. A.; Gordillo, G.

2010-11-01

In this paper AgInS2 and Zn(O,OH)S thin films were synthesized and characterized. AgInS2 layers were grown by co-evaporation from metal precursors in a two-step process, and, Zn(O,OH)S thin films were deposited from chemical bath containing thiourea, zinc acetate, sodium citrate and ammonia. X-ray diffraction measurements indicated that AgInS2 thin films grown with chalcopyrite structure, and the as-grown Zn(O,OH)S thin films were polycrystalline. It was also found that the AgInS2 films presented p-type conductivity, a high absorption coefficient (greater than 104 cm-1) and energy band-gap Eg of about 1.95 eV, Zn(O,OH),S thin films presented Eg of about 3.89 eV. Morphological analysis showed that under this synthesis conditions Zn(O,OH),S thin films coated uniformly the absorber layer. Additionally, the Zn(O,OH)S kinetic growth on AgInS2 layer was studied also. Finally, the results suggest that these layers possibly could be used in one-junction solar cells and/or as top cell in a tandem solar cell.

Isoelectric point and adsorption activity of porous g-C3N4

NASA Astrophysics Data System (ADS)

Zhu, Bicheng; Xia, Pengfei; Ho, Wingkei; Yu, Jiaguo

2015-07-01

The isoelectric point (IEP) is an important physicochemical parameter of many compounds, such as oxides, hydroxides, and nitrides, and can contribute to estimation of the surface charges of compound particles at various pH conditions. In this work, three types of graphitic carbon nitrides (g-C3N4) were synthesized by directly heating melamine, thiourea, and urea. The prepared samples showed different microstructures and IEPs that influenced their adsorption activity. Differences in microstructure resulted from the various precursors used during synthesis. The IEPs of the obtained g-C3N4 were measured to be approximately 4-5, which is due to the equilibrium of chemical reactions between hydrogen ions, hydroxyl ions, and amine groups on the g-C3N4 surface. The IEP of g-C3N4 prepared from thiourea was lower than those of the corresponding samples prepared from melamine and urea. The adsorption activity of methylene blue on g-C3N4 prepared from urea and thiourea was excellent, which indicates that g-C3N4 is a promising adsorbent. This work provides a useful reference for choosing precursors with which to prepare g-C3N4 and combining g-C3N4 with other compounds in solution.

Structure and properties of novel fibers spun from cellulose in NaOH/thiourea aqueous solution.

PubMed

Ruan, Dong; Zhang, Lina; Zhou, Jinping; Jin, Huiming; Chen, Hui

2004-12-15

Cellulose was dissolved rapidly in a NaOH/thiourea aqueous solution (9.5:4.5 in wt.-%) to prepare a transparent cellulose solution, which was employed, for the first time, to spin a new class of regenerated cellulose fibers by wet spinning. The structure and mechanical properties of the resulting cellulose fibers were characterized, and compared with those of commercially available viscose rayon, cuprammonium rayon and Lyocell fibers. The results from wide angle X-ray diffraction and CP/MAS 13C NMR indicated that the novel cellulose fibers have a structure typical for a family II cellulose and possessed relatively high degrees of crystallinity. Scanning electron microscopy (SEM) and optical microscopy images revealed that the cross-section of the fibers is circular, similar to natural silk. The new fibers have higher molecular weights and better mechanical properties than those of viscose rayon. This low-cost technology is simple, different from the polluting viscose process. The dissolution and regeneration of the cellulose in the NaOH/thiourea aqueous solutions were a physical process and a sol-gel transition rather than a chemical reaction, leading to the smoothness and luster of the fibers. This work provides a potential application in the field of functional fiber manufacturing.

Syntheses, structures and properties of homo- and heterobimetallic complexes of the type [Zn(tren)NCS] 2[M(NCS) 4] [tren = tris(2-aminoethyl)amine; M = Zn, Cu

NASA Astrophysics Data System (ADS)

Chattopadhyay, Soumi; Bhar, Kishalay; Das, Sumitra; Chantrapromma, Suchada; Fun, Hoong-Kun; Ghosh, Barindra Kumar

2010-04-01

A 2:2:1:6 molar ratio of Zn(ClO 4) 2·6H 2O, tris(2-aminoethyl)amine (tren), Zn(ClO 4) 2·6H 2O/Cu(ClO 4) 2·6H 2O and NH 4NCS in methanol-water solution mixtures affords homo-/heterobimetallic compounds of the type [Zn(tren)NCS] 2[M(NCS) 4] (M = Zn, 1; M = Cu, 2) which have been characterized using microanalytical, spectroscopic, magnetic and other physicochemical results. The structures of the compounds are determined by X-ray diffraction measurements. Structural analyses reveal that 1 and 2 are isomorphous and consist of two discrete [Zn(tren)NCS] + cations and a [M(NCS) 4] 2- (M = Zn/Cu) anion. Zinc(II) centers in the [Zn(tren)NCS] + units adopt distorted trigonal bipyramidal geometry with ZnN 5 chromophores coordinated through four N atoms of tren and one N atom of terminal thiocyanate. Each metal(II) center in [M(NCS) 4] 2- has a distorted tetrahedral coordination environment with an MN 4 chromophore ligated by four N atoms of the terminal thiocyanates. In solid state, doubly N-H…S hydrogen bonded 1D chains of [Zn(tren)NCS] + cations are interconnected by tetrahedral [Zn(NCS) 4] 2-/[Cu(NCS) 4] 2- anions through cooperative N-H…S and N-H…N (in 1) and N-H…S and C-H…S (in 2) hydrogen bonds resulting in 3D network structures. Establishment of such networks seems to be aiding the crystallization.

Interactions of TRIS [tris(hydroxymethyl)aminomethane] and related buffers with peptide backbone: thermodynamic characterization.

PubMed

Taha, Mohamed; Lee, Ming-Jer

2010-10-21

In a situation which is far from ideal, many buffers have been found to be quite reactive, besides maintaining their stable pH values. On the basis of apparent transfer free energies (ΔG(tr)'), through solubility measurements the interactions of zwitterionic glycine peptides: glycine (Gly), diglycine (Gly(2)), triglycine (Gly(3)), and tetraglycine (Gly(4)), with several common neutral pH, amine-based buffers have been studied. The biological buffers studied in this work, including TRIS, TES, TAPS, TAPSO, and TABS are structurally related and all contain TRIS groups. These buffers have pK(a) values ranging from 7.5-9.0, which allow them to be used in biological, biochemical or environmental studies. We observed negative values of ΔG(tr)' for Gly(3) and Gly(4) from water to buffer, indicating that the interactions are favorable. However, the ΔG(tr)' values are positive for Gly and Gly(2), revealing unfavorable interactions, which except for the latter in TRIS buffer are negative. The surprising result in our data is the unexpected extraordinarily high favorable interactions between TRIS buffer and peptides (in comparison with the effect of the most common denaturants, urea and guanidine hydrochloride). The transfer free energies (ΔG(tr)') of the peptide backbone unit (-CH(2)C=O-NH-) contributions have been estimated from ΔG(tr)' values. We have also investigated the interactions of TRIS buffer with Bovine Serum Albumin (BSA), as a globular protein, using dynamic light scattering (DLS), zeta potential, UV-Visible absorption, fluorescence and Raman spectroscopy measurements. The results indicated that TRIS buffer stabilized the BSA molecules.

The action of diazoxide and minoxidil sulphate on rat blood vessels: a comparison with cromakalim.

PubMed Central

Newgreen, D. T.; Bray, K. M.; McHarg, A. D.; Weston, A. H.; Duty, S.; Brown, B. S.; Kay, P. B.; Edwards, G.; Longmore, J.; Southerton, J. S.

1990-01-01

1. The actions of diazoxide and minoxidil sulphate have been compared with those of cromakalim in rat aorta and portal vein. 2. Diazoxide and minoxidil sulphate hyperpolarized the rat portal vein in a similar manner to cromakalim. 3. Cromakalim, diazoxide and minoxidil sulphate increased 42K and 86Rb efflux from rat portal vein, although minoxidil sulphate had only a small effect on 86Rb efflux. 4. Cromakalim, diazoxide and minoxidil sulphate increased 42K efflux from rat aorta but only cromakalim and diazoxide increased 86Rb efflux from this tissue. 5. Glibenclamide inhibited the relaxant actions of cromakalim, diazoxide and minoxidil sulphate on rat aorta and the increase in 42K efflux produced by these agents in this tissue. 6. Diazoxide relaxed an 80 mM KCl-induced contraction of rat aorta, whilst cromakalim and minoxidil sulphate were without effect. 7. Cromakalim, diazoxide and minoxidil sulphate had no effect on cyclic AMP or cyclic GMP concentrations in rat aorta. 8. It is concluded that diazoxide and minoxidil sulphate like cromakalim exhibit K+ channel opening properties in vascular smooth muscle. Diazoxide exerts an additional inhibitory action not related to the production of cyclic AMP or cyclic GMP. The action of minoxidil sulphate may be primarily located at a K+ channel which is relatively impermeable to 86Rb. PMID:2167738

Sulphur cycling in the drinking water catchment area of Torgau-Mockritz (Germany): insights from hydrochemical and stable isotope investigations

NASA Astrophysics Data System (ADS)

Knöller, K.; Trettin, R.; Strauch, G.

2005-11-01

The hydrochemical composition of groundwater and the isotopic composition of sulphur compounds in sediments (34S of sulphide, inorganic sulphate) and groundwater (34S, 18O of dissolved sulphate) have been investigated to reveal the reasons for elevated concentrations of dissolved groundwater sulphate in the drinking water catchment area of Torgau-Mockritz (Germany).The three most important anthropogenic sources of sulphate identified in this study are historic atmospheric sulphate deposition, predominantly of anthropogenic origin, inorganic fertilization, and dissolution of gypsum from waste dumps. Owing to their overlapping isotopic range, no clear differentiation between the individual anthropogenic sources is possible. Sulphate from the oxidation of sedimentary sulphides, however, was recognized by its negative sulphur isotope signature (34S < - 5).The mobilization of sulphate from different soil sulphur species is closely connected with variable isotopic fractionations, resulting in a wide isotopic variation range for the sulphate entering the saturated zone. Generally, sulphur and oxygen isotope ratios of the dissolved groundwater sulphate range from -19 to +37 (Vienna Cañon Diablo troilite) and from -2 to +19 (Vienna standard mean ocean water), respectively. Sulphate from the majority of groundwater samples can be assigned to anthropogenic sources. Sulphate from sulphide oxidation is especially present in samples from the upper sampling level and the groundwater surface. Sulphate concentrations above 700 mg l-1 are mostly caused by the oxidation of sulphide. Sulphate that occurs in low and moderate concentrations dominantly originates from anthropogenic sources.34S distribution patterns were used to locate the sources for the elevated sulphate concentrations in the raw water. It was shown that the sulphate is not mobilized in the immediate vicinity of the production wells. Rather, it originates in an area 1.5 km west of the intake. The main mobilization mechanism there is the oxidation of reduced sedimentary sulphur species.Beyond its local significance, this study presents a general example how changes in the sulphur cycle indicate major, anthropogenically induced alterations of the hydrochemical situation in catchment areas. Copyright

Sulphate transport by H+ symport and by the dicarboxylate carrier in mitochondria.

PubMed Central

Saris, N E

1980-01-01

1. Swelling of mitochondria was induced in non-respiring mitochondria by 30 mM or more Na2SO4 or by respiration in the presence of K2SO4. Respiration-drive swelling resulted in loss of respiratory control. Sulphate, when present at 10 mM concentration, promoted the release of accumulated Ca2+. 2. Swelling was prevented by N-ethylmaleimide and formaldehyde, known inhibitors of the phosphate carrier. Sulphate-induced swelling was more sensitive to the inhibitors than was phosphate-induced swelling. At lower concentration of sulphate, 5 mM, an alkalinisation of the medium was observed in addition of sulphate, indicating H+-sulphate symport. There was competition between sulphate and phosphate for transport by this mechanism. It is suggested that sulphate may be transported, though at a comparatively slow rate, by the phosphate carrier. 3. Uptake of sulphate was stimulated when preceded by energy-dependent accumulation of Ba2+, especially when acetate was also present, indicating precipitation of BaSO4 in the matrix. Using this system the influx of sulphate was studied at lower concentrations, 10 mM or less. the contributions of the H+ symporter (sensitive to N-ethylmaleimide) and the dicarboxylate carrier (sensitive to butylmalonate) could then be studied. The dicarboxylate carrier had a lower Km and was mainly responsible for sulphate transport at lower concentration range. At 10 mM-sulphate the transport rates by the two systems appeared to be similar; at still higher concentrations the H+ symporter may become more important. PMID:7236245

Anticoagulant, antiherpetic and antibacterial activities of sulphated polysaccharide from Indian medicinal plant Tridax procumbens L. (Asteraceae).

PubMed

Naqash, Shabeena Yousuf; Nazeer, R A

2011-10-01

The sulphated polysaccharide from the widespread Tridax procumbens plant was studied for the anticoagulant, antiherpetic and antibacterial activity. The anticoagulant activity was determined by the activated partial thromboplastin time assay. The sulphated polysaccharide from T. procumbens represented potent anticoagulant reaching the efficacy to heparin and chondroitin sulphate. Moreover, the sulphated polysaccharide extracted from T. procumbens was found non-toxic on Vero cell lines up to the concentration of 200 μg/ml. Sulphated polysaccharide exhibited detectable antiviral effect towards HSV-1 with IC(50) value 100-150 μg/ml. Furthermore, sulphated polysaccharide from T. procumbens was highly inhibitory against the bacterial strains Vibrio alginolyticus and Vibrio harveyi isolated from oil sardine.

Epitaxial lift-off of electrodeposited single-crystal gold foils for flexible electronics

NASA Astrophysics Data System (ADS)

Mahenderkar, Naveen K.; Chen, Qingzhi; Liu, Ying-Chau; Duchild, Alexander R.; Hofheins, Seth; Chason, Eric; Switzer, Jay A.

2017-03-01

We introduce a simple and inexpensive procedure for epitaxial lift-off of wafer-size flexible and transparent foils of single-crystal gold using silicon as a template. Lateral electrochemical undergrowth of a sacrificial SiOx layer was achieved by photoelectrochemically oxidizing silicon under light irradiation. A 28-nanometer-thick gold foil with a sheet resistance of 7 ohms per square showed only a 4% increase in resistance after 4000 bending cycles. A flexible organic light-emitting diode based on tris(bipyridyl)ruthenium(II) that was spin-coated on a foil exploited the transmittance and flexibility of the gold foil. Cuprous oxide as an inorganic semiconductor that was epitaxially electrodeposited onto the gold foils exhibited a diode quality factor n of 1.6 (where n = 1.0 for an ideal diode), compared with a value of 3.1 for a polycrystalline deposit. Zinc oxide nanowires electrodeposited epitaxially on a gold foil also showed flexibility, with the nanowires intact up to 500 bending cycles.

White OLED in Hybrid Structure for Enhancing Color Purity.

PubMed

Kim, Dong-Eun; Kang, Min-Jae; Park, Gwang-Ryeol; Lee, Burm-Jong; Kwon, Young-Soo; Shin, Hoon-Kyu

2016-06-01

We synthesized the red emission material, bis(1,4-bis(5-phenyloxazol-2-yl)phenyl) iridium(picolate) [Ir-complexes] and the blue emission material, bis (2-(2-hydroxyphenyl) benzoxazolate)zinc [Zn(HPB)2]. White Organic Light Emitting Diodes were fabricated by using Zn(HPB)2 for a blue emitting layer, Ir-complexes for a red emitting layer and a tris (8-hydroxy quinoline)aluminum [Alq3] for a green emitting layer. The important experimental results obtained, white OLED was fabricated by using double emitting layers of Zn(HPB)2 and Alq3:Ir-complexes, and hole blocking layer of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline[BCP]. We also varied the thickness of BCP. When the thickness of BCP layer was 5 nm, white emission was achieved. We obtained a maximum luminance of 5400 cd/m2 at a current density of 650 mA/cm2. The CIE coordinates was (0.339, 0.323) at voltage of 10 V.

[The role of heavy metals and their derivatives in the selection of antibiotics resistant gram-negative rods (author's transl)].

PubMed

Joly, B; Cluzel, R

1975-01-01

The authors have studied 116 Gram-negative strains, 27 of which were sensitive to antibiotics and 89 showed multiple resistance. The MIC of mercury chloride, mercuric nitrate and of an aqueous solution of mercuresceine were much higher in the case of the sensitive strains. The transfer of resistance to mercury, which has been achieved in 56% of cases, was always accompanied by transfer of resistance to the antibiotics. The MIC of phenylmercury borate, mercurothiolic acid and other heavy metals (such as: cobaltous nitrate, silver nitrate, cadmium nitrate, nickel nitrate, zinc nitrate, copper sulphate and sodium arsenate) are approximatively the same for all strains. The normal concentrations of mercury in nature are lower than the rate of microbial selection. But in areas of accumulation, particularly in biological chains or in hospitals, the mercury compounds could play a part in the selection of antibiotic resistant Gram-negative bacteria.

Major inorganic elements in tap water samples in Peninsular Malaysia.

PubMed

Azrina, A; Khoo, H E; Idris, M A; Amin, I; Razman, M R

2011-08-01

Quality drinking water should be free from harmful levels of impurities such as heavy metals and other inorganic elements. Samples of tap water collected from 24 locations in Peninsular Malaysia were determined for inorganic element content. Minerals and heavy metals were analysed by spectroscopy methods, while non-metal elements were analysed using test kits. Minerals and heavy metals determined were sodium, magnesium, potassium, calcium, chromium, manganese, iron, nickel, copper, zinc, arsenic, cadmium and lead while the non-metal elements were fluoride, chloride, nitrate and sulphate. Most of the inorganic elements found in the samples were below the maximum permitted levels recommended by inter-national drinking water standard limits, except for iron and manganese. Iron concentration of tap water from one of the locations was higher than the standard limit. In general, tap water from different parts of Peninsular Malaysia had low concentrations of heavy metals and inorganic elements.

Experimental Germ Tube Induction in Candida albicans: An Evaluation of the Effect of Sodium Bicarbonate on Morphogenesis and Comparison with Pooled Human Serum.

PubMed

Matare, Tapiwa; Nziramasanga, Pasipanodya; Gwanzura, Lovemore; Robertson, Valerie

2017-01-01

The potential of NaHCO 3 versus human serum to induce germ tube formation in Candida albicans was investigated. A total of 100 isolates were obtained from oral swabs of patients presenting with thrush. Approval for the study was granted by the Joint Research Ethics Committee (JREC/23/08). Confirmed C. albicans isolates by routine methods were tested for germ tube induction using 5 different concentrations of Tris-maleate buffered NaHCO 3 and Tris-maleate buffer control. Standard control strains included were C. albicans (ATCC 10231) and C. krusei (ATCC 6258). Microculture was done in 20  μ L inoculums on microscope slides for 3 hours at 37°C. The rate of germ tube formation at 10-minute intervals was determined on 100 isolates using the optimum 20 mM Tris-maleate buffered NaHCO 3 concentration. Parallel germ tube formation using human serum was done in test tubes. The optimum concentration of NaHCO 3 in Tris-maleate buffer for germ tube induction was 20 mM for 67% of isolates. Only 21% of isolates formed germ tubes in Tris-maleate buffer control. There was no significant difference in induction between human serum and Tris-maleate buffered NaHCO 3 . Tris-maleate buffered NaHCO 3 induced germ tube formation in C. albicans isolates at rates similar to human serum.

Transcriptional response of Medicago truncatula sulphate transporters to arbuscular mycorrhizal symbiosis with and without sulphur stress.

PubMed

Casieri, Leonardo; Gallardo, Karine; Wipf, Daniel

2012-06-01

Sulphur is an essential macronutrient for plant growth, development and response to various abiotic and biotic stresses due to its key role in the biosynthesis of many S-containing compounds. Sulphate represents a very small portion of soil S pull and it is the only form that plant roots can uptake and mobilize through H(+)-dependent co-transport processes implying sulphate transporters. Unlike the other organically bound forms of S, sulphate is normally leached from soils due to its solubility in water, thus reducing its availability to plants. Although our knowledge of plant sulphate transporters has been growing significantly in the past decades, little is still known about the effect of the arbuscular mycorrhiza interaction on sulphur uptake. Carbon, nitrogen and sulphur measurements in plant parts and expression analysis of genes encoding putative Medicago sulphate transporters (MtSULTRs) were performed to better understand the beneficial effects of mycorrhizal interaction on Medicago truncatula plants colonized by Glomus intraradices at different sulphate concentrations. Mycorrhization significantly promoted plant growth and sulphur content, suggesting increased sulphate absorption. In silico analyses allowed identifying eight putative MtSULTRs phylogenetically distributed over the four sulphate transporter groups. Some putative MtSULTRs were transcribed differentially in roots and leaves and affected by sulphate concentration, while others were more constitutively transcribed. Mycorrhizal-inducible and -repressed MtSULTRs transcripts were identified allowing to shed light on the role of mycorrhizal interaction in sulphate uptake.

Macrocyclic bis-thioureas catalyze stereospecific glycosylation reactions.

PubMed

Park, Yongho; Harper, Kaid C; Kuhl, Nadine; Kwan, Eugene E; Liu, Richard Y; Jacobsen, Eric N

2017-01-13

Carbohydrates are involved in nearly all aspects of biochemistry, but their complex chemical structures present long-standing practical challenges to their synthesis. In particular, stereochemical outcomes in glycosylation reactions are highly dependent on the steric and electronic properties of coupling partners; thus, carbohydrate synthesis is not easily predictable. Here we report the discovery of a macrocyclic bis-thiourea derivative that catalyzes stereospecific invertive substitution pathways of glycosyl chlorides. The utility of the catalyst is demonstrated in the synthesis of trans-1,2-, cis-1,2-, and 2-deoxy-β-glycosides. Mechanistic studies are consistent with a cooperative mechanism in which an electrophile and a nucleophile are simultaneously activated to effect a stereospecific substitution reaction. Copyright © 2017, American Association for the Advancement of Science.

Improvement of the solubilization of proteins in two-dimensional electrophoresis with immobilized pH gradients

PubMed Central

Rabilloud, Thierry; Adessi, C.; Giraudel, A.; Lunardi, J.

2007-01-01

Summary We have carried out the separation of sparingly-soluble (membrane and nuclear) proteins by high resolution two-dimensional electrophoresis. IEF with immobilized pH gradients leads to severe quantitative losses of proteins in the resulting 2-D map, although the resolution is usually kept high. We therefore tried to improve the solubility of proteins in this technique, by using denaturing cocktails containing various detergents and chaotropes. Best results were obtained by using a denaturing solution containing urea, thiourea, and detergents (both nonionic and zwitterionic). The usefulness of thiourea-containing denaturing mixtures are shown in this article on several models including microsomal and nuclear proteins and on tubulin, a protein highly prone to aggregation. PMID:9150907

Phenolic sodium sulphates of Frankenia laevis L.

PubMed

Hussein, S A M

2004-04-01

Four new phenolic anionic conjugates have been isolated from the whole plant aqueous alcohol extract of Frankenia laevis L. Their structures were established, mainly on the basis of ESI-MS, 1D and 2D NMR spectroscopic evidence, as gallic acid-3-methyl ether-5-sodium sulphate, acetophenone-4-methyl ether-2-sodium sulphate, ellagic acid-3,3'-dimethyl ether-4,4'-di-sodium sulphate and ellagic acid-3-methyl ether-4-sodium sulphate.

Sulphation of acetaminophen by the human cytosolic sulfotransferases: a systematic analysis

PubMed Central

Yamamoto, Akihiro; Liu, Ming-Yih; Kurogi, Katsuhisa; Sakakibara, Yoichi; Saeki, Yuichi; Suiko, Masahito; Liu, Ming-Cheh

2015-01-01

Sulphation is known to be critically involved in the metabolism of acetaminophen in vivo. This study aimed to systematically identify the major human cytosolic sulfotransferase (SULT) enzyme(s) responsible for the sulphation of acetaminophen. A systematic analysis showed that three of the twelve human SULTs, SULT1A1, SULT1A3 and SULT1C4, displayed the strongest sulphating activity towards acetaminophen. The pH dependence of the sulphation of acetaminophen by each of these three SULTs was examined. Kinetic parameters of these three SULTs in catalysing acetaminophen sulphation were determined. Moreover, sulphation of acetaminophen was shown to occur in HepG2 human hepatoma cells and Caco-2 human intestinal epithelial cells under the metabolic setting. Of the four human organ samples tested, liver and intestine cytosols displayed considerably higher acetaminophen-sulphating activity than those of lung and kidney. Collectively, these results provided useful information concerning the biochemical basis underlying the metabolism of acetaminophen in vivo previously reported. PMID:26067475

Sulphate removal from sodium sulphate-rich brine and recovery of barium as a barium salt mixture.

PubMed

Vadapalli, Viswanath R K; Zvimba, John N; Mulopo, Jean; Motaung, Solly

2013-01-01

Sulphate removal from sodium sulphate-rich brine using barium hydroxide and recovery of the barium salts has been investigated. The sodium sulphate-rich brine treated with different dosages of barium hydroxide to precipitate barium sulphate showed sulphate removal from 13.5 g/L to less than 400 mg/L over 60 min using a barium to sulphate molar ratio of 1.1. The thermal conversion of precipitated barium sulphate to barium sulphide achieved a conversion yield of 85% using coal as both a reducing agent and an energy source. The recovery of a pure mixture of barium salts from barium sulphide, which involved dissolution of barium sulphide and reaction with ammonium hydroxide resulted in recovery of a mixture of barium carbonate (62%) and barium hydroxide (38%), which is a critical input raw material for barium salts based acid mine drainage (AMD) desalination technologies. Under alkaline conditions of this barium salt mixture recovery process, ammonia gas is given off, while hydrogen sulfide is retained in solution as bisulfide species, and this provides basis for ammonium hydroxide separation and recovery for reuse, with hydrogen sulfide also recoverable for further industrial applications such as sulfur production by subsequent stripping.

Biotic conversion of sulphate to sulphide and abiotic conversion of sulphide to sulphur in a microbial fuel cell using cobalt oxide octahedrons as cathode catalyst.

PubMed

Chatterjee, Pritha; Ghangrekar, M M; Rao, Surampalli; Kumar, Senthil

2017-05-01

Varying chemical oxygen demand (COD) and sulphate concentrations in substrate were used to determine reaction kinetics and mass balance of organic matter and sulphate transformation in a microbial fuel cell (MFC). MFC with anodic chamber volume of 1 L, fed with wastewater having COD of 500 mg/L and sulphate of 200 mg/L, could harvest power of 54.4 mW/m 2 , at a Coulombic efficiency of 14%, with respective COD and sulphate removals of 90 and 95%. Sulphide concentration, even up to 1500 mg/L, did not inhibit anodic biochemical reactions, due to instantaneous abiotic oxidation to sulphur, at high inlet sulphate. Experiments on abiotic oxidation of sulphide to sulphur revealed maximum oxidation taking place at an anodic potential of -200 mV. More than 99% sulphate removal could be achieved in a MFC with inlet COD/sulphate of 0.75, giving around 1.33 kg/m 3  day COD removal. Bioelectrochemical conversion of sulphate facilitating sulphur recovery in a MFC makes it an interesting pollution abatement technique.

Analysis of surface tris (2,3-dibromopropyl) phosphate on chlorobutyl rubber SCAPE suits. [flame retardant coatings

NASA Technical Reports Server (NTRS)

Schehl, T. A.; Bennett, H. D.; Bryan, C. J.; Bright, C. W.

1978-01-01

Tris (2,30-dibromopropyl) phosphate was used to confer flame retardant properties on butyl rubber formulations used in protective clothing such as the self-contained atmospheric protective ensembles (SCAPE suits) worn at Kennedy Space Center in support of Apollo, Skylab, and Apollo-Soyuz missions since 1966. Because tris (2,3-dibromopropyl) phosphate is mutagenic, surface concentrations of the compound in SCAPE suits were investigated as were as potential methods of removing or isolating it. Analytical procedures for determining surface concentrations of the tris compound on non-porous materials are described. Soap-and-water washing is the most efficient method of removing the compound from fabricated SCAPE suits and unused material.

Implementation of a vaccine against Shigatoxin 2e in a piglet producing farm with problems of Oedema disease: case study.

PubMed

Fricke, Regine; Bastert, Olaf; Gotter, Verena; Brons, Nico; Kamp, Johan; Selbitz, Hans-Joachim

2015-01-01

Oedema disease is one of the major diseases in pigs during the nursery period. It is caused by Shigatoxin 2e producing strains of Escherichia coli . In order to combat the disease, the metaphylactic use of colistin sulphate and zinc oxide is widely spread. Additionally, special feeding regimens such as the reduction of the amount of crude protein and the increase of the amount of crude fibre are applied. The goal of this study was to test the efficacy of a vaccine against Oedema disease caused by Shigatoxin 2e in a field trial on a farm with a history of Oedema disease in nursery pigs. The study was carried out on a Dutch farm with 600 sows and a one-week farrowing rhythm and lasted for the time of one year. During this time all piglets were vaccinated with 1 ml ECOPORC SHIGA at the average age of 4 days. The parameters Overall mortality, use of antimicrobials in general, calculated as defined daily dose per animal, use of colistin sulphate and the weight gain were evaluated for all nursery pigs and compared to historical data of animals from the same period of time directly prior to the study serving as a historical control group. The previous mortality in the nursery of 7.7% was significantly reduced to 1.3% after vaccination. The metaphylactic use of colistin sulphate during the nursery period was stopped during the study because no deaths due to Oedema disease had occurred anymore after beginning of vaccination. The defined daily dose per animal per month was significantly reduced from a mean of 1.050 in the year 2012 to a mean of 0.215 in the year 2013. The defined daily dose per animal per year was therefore relevantly reduced from 12.6 in 2012 to 2.6 in 2013. These results show that on this farm Oedema disease can not only be controlled successfully by vaccination but also that vaccination can significantly reduce the use of antimicrobials in the nursery period.

Sulphates Removal from Acid Mine Drainage

NASA Astrophysics Data System (ADS)

Luptáková, Alena; Mačingová, Eva; Kotuličová, Ingrida; Rudzanová, Dominika

2016-10-01

Acid mine drainage (AMD) are a worldwide problem leading to ecological destruction in river basins and the contamination of water sources. AMD are characterized by low pH and high content of heavy metals and sulphates. In order to minimize negative impacts of AMD appropriate treatment techniques has to be chosen. Treatment processes are focused on neutralizing, stabilizing and removing pollutants. From this reason efficient and environmental friendly methods are needed to be developed in order to reduce heavy metals as well as sulphates. Various methods are used for remediation of acid mine drainage, but any of them have been applied under commercial-scale conditions. Their application depends on geochemical, technical, natural, financial, and other factors. The aim of the present work was to interpret the study of biological methods for sulphates removal from AMD out-flowing from the shaft Pech of the deposit Smolmk in Slovak Republic. In the experimental works AMD were used after removal of heavy metals by precipitation and sorption using the synthetic sorbent Slovakite. The base of the studied method for the sulphates elimination was the anaerobic bacterial sulphate reduction using sulphate-reducing bacteria (SRB) genera Desulfovibrio. SRB represent a group of bacteria that uses sulphates as a terminal electron acceptor for their metabolism. These bacteria realize the conversion of sulphate to hydrogen sulphide under anaerobic conditions. For the purposes of experiments a few variants of the selective medium DSM-63 culture media were used in term of the sulphates and sodium lactate contents in the selective medium as well as sulphates in the studied AMD.

Speciation analysis and bioaccessibility evaluation of trace elements in goji berries (Lycium Barbarum, L.).

PubMed

Wojcieszek, Justyna; Kwiatkowski, Piotr; Ruzik, Lena

2017-04-07

Goji berries (Lycium Barbarum, L.) are known for their nutritional potential as a great source of trace metals (e.g., copper, zinc and manganese) which are present in the form of highly bioaccessible compounds. In order to assess the bioaccessibility of trace elements and to identify compounds responsible for better bioaccessibility of copper and zinc, an in vitro simulation of gastrointestinal digestion was used in this study. The total content of trace metals was evaluated using sample digestion followed by inductively coupled plasma mass spectrometry. Bioaccessibility of trace elements was estimated by size exclusion chromatography coupled to inductively coupled plasma mass spectrometry. These analytical methods were used to analyse samples of goji berries to determine the highest amount of elements. For total trace metal content in goji berries, Zn had the highest level of the three studied (10.6μgg -1 ), while the total content of manganese and copper was 9.9μgg -1 and 6.1μgg -1 , respectively. Additionally, the analysed metals were found to be highly bioaccessible to the human body (about 56% for Mn, 72% for Cu and 64% for Zn in the gastric extract and approximately 35% for Mn, 23% for Cu and 31% for Zn in the case of gastrointestinal extract). To obtain information about metal complexes present in goji berries, extraction treatment using different solutions (ionic liquid, HEPES, SDS, Tris-HCl, ammonium acetate, water) was performed. Enzymatic treatment using pectinase and hemicellulase was also checked. Extracts of berries were analysed by SEC-ICP-MS and μHPLC-ESI-MS/MS techniques. The ionic liquid and pectinase extraction helped efficiently extract copper (seven compounds) and zinc (four compounds) complexes. Compounds identified in goji berries are most likely to be responsible for better bioaccessibility of those elements to the human organism. Copyright © 2017 Elsevier B.V. All rights reserved.

Deep freezing of Angora goat semen: effects of diluent composition and method and rate of dilution on survival of spermatozoa.

PubMed

Salamon, S; Ritar, A J

1982-01-01

Five factorial experiments were conducted to examine the effects of concentration of tris(hydroxymethyl)aminomethane (Tris), type and concentration of sugar in the diluent, rate and method of dilution on the survival of goat spermatozoa after freezing by the pellet method. Spermatozoa tolerated a relatively wide range in concentration of Tris, but the cell survival depended on the type of sugar included in the Tris diluent. Glucose and fructose were more suitable components than lactose or raffinose. Survival of spermatozoa after thawing was better for three- to fivefold prefreezing dilution. There was interaction between method of semen dilution (one-step, two-step), holding time at 5 degrees C, and glycerol concentration. The best result was obtained after one-step dilution at 30 degrees C (Tris 375 mM-glucose 41.625 mM-citric acid 124 mM), 1.5 h holding at 5 degrees C, and with 4% (v/v) glycerol concentration in the diluted semen.

Mössbauer study of the thermal decomposition of alkali tris(oxalato)ferrates(III)

NASA Astrophysics Data System (ADS)

Brar, A. S.; Randhawa, B. S.

1985-07-01

The thermal decomposition of alkali (Li,Na,K,Cs,NH 4) tris(oxalato)ferrates(III) has been studied at different temperatures up to 700°C using Mössbauer, infrared spectroscopy, and thermogravimetric techniques. The formation of different intermediates has been observed during thermal decomposition. The decomposition in these complexes starts at different temperatures, i.e., at 200°C in the case of lithium, cesium, and ammonium ferrate(III), 250°C in the case of sodium, and 270°C in the case of potassium tris(oxalato)ferrate(III). The intermediates, i.e., Fe 11C 2O 4, K 6Fe 112(ox) 5. and Cs 2Fe 11 (ox) 2(H 2O) 2, are formed during thermal decomposition of lithium, potassium, and cesium tris(oxalato)ferrates(III), respectively. In the case of sodium and ammonium tris(oxalato)ferrates(III), the decomposition occurs without reduction to the iron(II) state and leads directly to α-Fe 2O 3.

DNA polymerases in the rat pituitary gland. Effect of oestrogens and sulpiride.

PubMed

Jahn, G A; Kalbermann, L E; Machiavelli, G; Szijan, I; Burdman, J A

1980-06-01

Changes in the activity of DNA polymerase and [3H]thymidine incorporation into the DNA of the anterior pituitary gland were studied in oestrogenized male and pregnant rats. The activities of DNA polymerases alpha and beta, extracted in Tris--HCl or in sodium phosphate buffer were characterized according to their optimum pH and sensitivity to N-ethyl-maleimide. In the Tris-soluble fraction DNA polymerase activity is almost exclusively alpha, while in the phosphate soluble fraction it is a mixture of alpha and beta. The administration of oestrogens to male rats increases [3H]thymidine incorporation and enhances the activity of DNA polymerases in the Tris-soluble fraction, while the activity of the phosphate-soluble enzyme does not change. Sulpiride administration results in a further increment of [3H]thymidine incorporation and of DNA polymerase activity in the Tris-soluble fraction. In pregnant rats sulpiride also produces an increment of DNA polymerase activity only in the Tris-soluble fraction. Thus, the activity of the Tris-soluble fraction from APG behaves as DNA polymerase alpha. This activity changes in parallel with [3H]thymidine incorporation into DNA which is an indication of cell proliferation in the gland. This is discussed with respect to a negative feedback mechanism between intracellular prolactin concentration and DNA synthesis in the APG.

Comparison of polyvinyl alcohol and tris-acryl gelatin microsphere materials in embolization for symptomatic leiomyomas: a systematic review.

PubMed

Jiang, Wenxiao; Shen, Zhaojun; Luo, Hui; Hu, Xiaoli; Zhu, Xueqiong

2016-12-01

Use systematic reviews and meta-analyses to assess the effect of polyvinyl alcohol and tris-acryl gelatin microsphere materials in leiomyoma embolization for symptomatic leiomyomas. We included randomised controlled studies published before January 2015 comparing polyvinyl alcohol and tris-acryl gelatin microsphere materials in uterine leiomyoma embolization for women with symptomatic leiomyomas. The main outcome measures included change of overall quality of life, change of overall symptom severity, changes of uterine and leiomyoma volumes, leiomyoma infarction rate, treatment failure and complications. A total of six randomized controlled studies from 335 studies accounting for 351 women with leiomyomas were identified in this meta-analysis. Compared to polyvinyl alcohol, tris-acryl gelatin microsphere showed a significant benefit in improving the overall quality of life and in reducing uterine volume at three and six months, in reducing overall symptom severity at 6 and 12 months, and furthermore in reducing treatment failure. In addition, tris-acryl gelatin microsphere could significantly reduce leiomyoma volume and decrease <90% complete leiomyoma infarction rate at three months. There were no differences in pain severity, other post-procedural symptoms or medication use in the two groups. A better effect of tris-acryl gelatin microsphere in leiomyoma embolization for patients with symptomatic leiomyoma.

Tris-EDTA significantly enhances antibiotic efficacy against multidrug-resistant Pseudomonas aeruginosa in vitro.

PubMed

Buckley, Laura M; McEwan, Neil A; Nuttall, Tim

2013-10-01

Multidrug-resistant Pseudomonas aeruginosa commonly complicates chronic bacterial otitis in dogs. The aim of this in vitro study was to determine the effect of ethylenediaminetetraacetic acid-tromethamine (Tris-EDTA) on the minimal bactericidal concentrations (MBCs) and minimal inhibitory concentrations (MICs) of marbofloxacin and gentamicin for multidrug-resistant P. aeruginosa isolates from cases of canine otitis. Eleven isolates were identified as multidrug resistant on disc diffusion; 10 were resistant to marbofloxacin and two were resistant to gentamicin. Isolates were incubated for 90 min with each antibiotic alone and in combination with Tris-EDTA at concentrations of 0.075 μg/mL to 5 mg/mL for marbofloxacin, 0.001 μg/mL to 10 mg/mL for gentamicin and 17.8:4.7 to 0.14:0.04 mg/mL for Tris-EDTA. Positive and negative controls were included. Aliquots of each antibiotic and/or Tris-EDTA concentration were subsequently transferred to sheep blood agar to determine the MBCs, and tryptone soy broth was added to the remaining suspensions to determine the MICs. Tris-EDTA alone was bacteriostatic but not bactericidal at any concentration. The addition of Tris-EDTA significantly reduced the median MBC (from 625 to 468.8 μg/mL; P < 0.001) and MIC (from 29.3 to 2.4 μg/mL; P = 0.008) of marbofloxacin, and the median MBC (from 625 to 39.1 μg/mL) and MIC (from 19.5 to 1.2 μg/mL) of gentamicin (both P < 0.001). Tris-EDTA significantly reduced the MBCs and MICs of marbofloxacin and gentamicin for multidrug-resistant P. aeruginosa in vitro. This may be of use to clinicians managing these infections in dogs. © 2013 ESVD and ACVD.

Organophosphorus flame retardants (PFRs) and plasticizers in house and car dust and the influence of electronic equipment.

PubMed

Brandsma, Sicco H; de Boer, Jacob; van Velzen, Martin J M; Leonards, Pim E G

2014-12-01

All nine PFRs studied were detected in house and car dust from the Netherlands with the exception of tris(butyl) phosphate (TNBP) and tris(isobutyl) phosphate (TIBP) in car dust. Tris(2-butoxyethyl) phosphate (TBOEP, median 22 μg g(-1)) was dominant in house dust collected around and on electronics followed by tris(2-chloroisopropyl) phosphate (TCIPP, median 1.3 μg g(-1)), tris(2-chloroethyl) phosphate (TCEP, median 1.3 μg g(-1)) and tris(phenyl) phosphate (TPHP, median 0.8 μg g(-1)). Levels of TPHP and tris(methylphenyl) phosphate (TMPP, also known as TCP) in house dust on electronics were significantly higher than in house dust collected around electronics, suggesting that electronic equipment has limited contribution to the PFR levels in house dust, with the exception of TPHP and TMPP. Car dust was dominated by tris(1,3-dichloroisopropyl) phosphate (TDCIPP) with the highest levels found in dust collected from the car seats (1100 μg g(-1)). The mean TDCIPP and TCIPP levels observed in car dust were significantly higher than the levels observed in dust collected around electronics. Significantly higher mean TMPP levels in dust taken from car seats were found compared to dust collected around the equipment (p<0.05). This is probably influenced by the use of TDCIPP, TCIPP in polyurethane foam (car seats) and the use of TMPP as plasticizer in car interiors. Worldwide four PFR patterns were observed in house dust. The PFR pattern in the Netherlands of TDCIPP, TMPP, TCEP, TCIPP and TPHP in house dust is comparable to the pattern found in six other countries, which may point to identical sources of these PFRs in the indoor environment. However, the PFR levels between the countries and within countries showed high variation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Transnitrosation of alicyclic N-nitrosamines containing a sulfur atom.

PubMed

Inami, Keiko; Kondo, Sonoe; Ono, Yuta; Saso, Chiharu; Mochizuki, Masataka

2013-12-15

Aromatic and aliphatic nitrosamines are known to transfer a nitrosonium ion to another amine. The transnitrosation of alicyclic N-nitroso compounds generates S-nitrosothiols, which are potential nitric oxide donors in vivo. In this study, certain alicyclic N-nitroso compounds based on non-mutagenic N-nitrosoproline or N-nitrosothioproline were synthesised, and the formation of S-nitrosoglutathione (GSNO) was quantified under acidic conditions. We then investigated the effect of a sulfur atom as the substituent and as a ring component on the GSNO formation. In the presence of thiourea under acidic conditions, GSNO was formed from N-nitrosoproline and glutathione, and an N-nitroso compound containing a sulfur atom and glutathione produced GSNO without thiourea. The quantity of GSNO derived from the reaction of the N-nitrosamines containing a sulfur atom and glutathione was higher than that from the N-nitrosoproline and glutathione plus thiourea. Among the analogues that contained a sulfur atom either in the ring or as a substituent, the thiazolidines produced a slightly higher quantity of GSNO than the analogue with a thioamide group. A compound containing sulfur atoms both in the ring and as a substituent exhibited the highest activity for GSNO formation among the alicyclic N-nitrosamines tested. The results indicate that the intramolecular sulfur atom plays an important role in the transnitrosation via alicyclic N-nitroso compounds to form GSNO. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Risk assessment for selected xenobiotics by bioassay methods with higher plants

NASA Astrophysics Data System (ADS)

Günther, Petra; Pestemer, Wilfried

1990-05-01

Different bioassays with higher plants were approved for use in a bioassay procedure for testing of xenobiotics according to the German Chemicals Act. Selected environmental pollutants (atrazine, cadmium chloride, 2,6-dichlorobenzonitrile, pentachlorophenol, potassium dichromate, thiourea), all from a list of reference chemicals, were tested with these methods. Dose-response curves for growth of oats and turnips were evaluated in soil and vermiculite (nonsorptive substrate), and availability to plants was calculated by comparing the EC50 values for one chemical in both substrates. The most active chemical was atrazine, followed by 2,6-dichlorobenzonitrile, pentachlorophenol, potassium dichromate, cadmium chloride, and thiourea. The least available compound to plants was pentachlorophenol, tested with turnips ( Brassica rapa var. rapa). The strongest inhibition of germination, demonstrated in an in vitro assay with garden cress ( Lepidium sativum), was found with 2,6-dichlorobenzonitrile, the lowest with atrazine. The effect of an extended exposure of the plants to the chemicals was evaluated in a long-term bioassay with oats ( Avena sativa) in hydroponic culture. Several dose-response curves during the growing period were derived. It was found that the EC50 values for atrazine and thiourea decreased markedly during the first four weeks; thereafter the changes were much smaller. As an overall conclusion, a bioassay procedure is proposed that can be included in the graduated plan recommended by the German Chemicals Act.

Combined spectroscopic, DFT, TD-DFT and MD study of newly synthesized thiourea derivative

NASA Astrophysics Data System (ADS)

Menon, Vidya V.; Sheena Mary, Y.; Shyma Mary, Y.; Panicker, C. Yohannan; Bielenica, Anna; Armaković, Stevan; Armaković, Sanja J.; Van Alsenoy, Christian

2018-03-01

A novel thiourea derivative, 1-(3-bromophenyl)-3-[3-(trifluoromethyl)phenyl]thiourea (ANF-22) is synthesized and characterized by FTIR, FT-Raman and NMR spectroscopy experimentally and theoretically. A detailed conformational analysis of the title molecule has been conducted in order to locate the lowest energy geometry, which was further subjected to the detailed investigation of spectroscopic, reactive, degradation and docking studies by density functional theory (DFT) calculations and molecular dynamics (MD) simulations. Time dependent DFT (TD-DFT) calculations have been used also in order to simulate UV spectra and investigate charge transfer within molecule. Natural bond orbital analysis has been performed analyzing the charge delocalization and using HOMO and LUMO energies the electronic properties are analyzed. Molecular electrostatic potential map is used for the quantitative measurement of active sites in the molecule. In order to determine the locations possibly prone to electrophilic attacks we have calculated average local ionization energies and mapped them to the electron density surface. Further insight into the local reactivity properties have been obtained by calculation of Fukui functions, also mapped to the electron density surface. Possible degradation properties by the autoxidation mechanism have been assessed by calculations of bond dissociation energies for hydrogen abstraction. Atoms of title molecule with significant interactions with water molecules have been determined by calculations of radial distribution functions. The title compound can be a lead compound for developing new analgesic drug.

Placental sulphate transport: a review of functional and molecular studies.

PubMed

Shennan, D B

2012-08-01

Sulphate is required by the feto-placental unit for a number of important conjugation and biosynthetic pathways. Functional studies performed several decades ago established that sulphate transport in human placental microvillus and basal membrane vesicles was mainly via a DIDS-sensitive anion-exchange mechanism. In contrast, no evidence was found for Na⁺-dependent transport. Studies performed using isolated human placental tissue confirmed anion-exchange as the main mechanism. More recently, molecular studies have established the presence of anion-exchange proteins which could play a role in transplacental sulphate movement. However, the presence of transcripts for NaS2 has been reported and has prompted the suggestion that Na⁺-sulphate cotransport may play an important role in maternal-fetal sulphate transport. This article reviews our present knowledge of placental sulphate transport, both functional and molecular, and attempts to form a model based on the available evidence. Copyright © 2012 Elsevier Ltd. All rights reserved.

The binding of sodium dodecyl sulphate to various proteins

PubMed Central

Pitt-Rivers, Rosalind; Impiombato, F. S. Ambesi

1968-01-01

1. The binding of sodium dodecyl sulphate to proteins by equilibrium dialysis was investigated. 2. Most of the proteins studied bound 90–100% of their weight of sodium dodecyl sulphate. 3. The glycoproteins studied bound 70–100% of their weight of sodium dodecyl sulphate, calculated in terms of the polypeptide moiety of the molecule. 4. Proteins not containing S·S groups bound about 140% of their weight of sodium dodecyl sulphate. 5. Reduction of four proteins containing S·S groups caused a rise in sodium dodecyl sulphate binding to 140% of the weight of protein. 6. The apparent micellar molecular weights of the protein–sodium dodecyl sulphate complexes were measured by the dye-solubilization method; they were all found to have approximately the same micellar molecular weight (34000–41000) irrespective of the molecular weight of the protein to which they were attached. PMID:4177067

Comparison of the effects of the K(+)-channel openers cromakalim and minoxidil sulphate on vascular smooth muscle.

PubMed Central

Wickenden, A. D.; Grimwood, S.; Grant, T. L.; Todd, M. H.

1991-01-01

1 The actions of the potassium channel openers, cromakalim and minoxidil sulphate, were compared in a range of isolated blood vessel preparations. 2 Cromakalim and minoxidil sulphate inhibited spontaneous mechanical activity of the guinea-pig portal vein and relaxed the noradrenaline precontracted rat aorta with similar potency. In contrast, minoxidil sulphate was less potent than cromakalim in inhibiting spontaneous activity in the rat portal vein and was essentially inactive in the noradrenaline precontracted rat mesenteric artery and rabbit aorta. 3 Minoxidil sulphate did not antagonize the effects of cromakalim in the rabbit aorta indicating it was not acting as a partial 'agonist'. 4 Charybdotoxin, noxiustoxin and rubidium failed to discriminate between cromakalim and minoxidil sulphate indicating that the apparently selective effects of minoxidil sulphate were not mediated by either Ca(2+)-activated potassium channels, delayed rectifiers or rubidium impermeable potassium channels. 5 Glibenclamide antagonized the effects of cromakalim in an apparently competitive manner whereas the effects of minoxidil sulphate were antagonized in a non-competitive manner. The involvement of subtypes of ATP-sensitive potassium channels is discussed. PMID:1878752

Simultaneous removal of ammonium-nitrogen and sulphate from wastewaters with an anaerobic attached-growth bioreactor.

PubMed

Zhao, Q I; Li, W; You, S J

2006-01-01

Some industrial wastewaters may contain ammonium-nitrogen and/or sulphate, which need to be removed before their discharge into natural water bodies to eliminate their severe pollution. In this paper, simultaneous removal of ammonium-nitrogen and sulphate with an anaerobic attached-growth bioreactor of 3.8 L incubated with sulphate reducing bacteria (SRB) was investigated. Artificial wastewater containing sodium sulphate as electron acceptor, ammonium chlorine as electron donor and glucose as carbon source for bacteria growth was used as the feed for the bioreactor. The loading rates of ammonium-nitrogen, sulphate and COD were 2.08 gN/m3 x d, 2.38 gS/m3 x d, 104.17 gCOD/m3 x d, respectively, with a N/S ratio of 1:1.14. The results demonstrated that removal rates of ammonium-nitrogen, sulphate and COD could reach 43.35%, 58.74% and 91.34%, respectively. Meanwhile, sulphur production was observed in effluent as well as molecular nitrogen in biogas, whose amounts increased with time substantially, suggesting the occurrence of simultaneous removal of ammonium-nitrogen and sulphate. This novel reaction provided the possibility to eliminate ammonium-nitrogen and sulphate simultaneously with accomplishment of COD removal from wastewater, making wastewater treatment more economical and sustainable.

Stable isotopic evidence for anaerobic maintained sulphate discharge in a polythermal glacier

NASA Astrophysics Data System (ADS)

Ansari, A. H.

2016-03-01

To understand the sources and sinks of sulphate and associated biogeochemical processes in a High Arctic environment, late winter snowpacks, the summer melt-waters and rock samples were collected and analysed for major ions and stable isotope tracers (δ18O, δ34S). The SO42bar/Clbar ratio reveal that more than 87% of sulphate (frequently > 95%) of total sulphate carried by the subglacial runoff and proglacial streams was derived from non-snowpack sources. The proximity of non-snowpack sulphate δ34S (∼8-19‰) to the δ34S of the major rocks in the vicinity (∼-6 to +18‰) suggest that the non-snowpack sulphate was principally derived from rock weathering. Furthermore, Ca2++Mg2+/SO42ˉ molar shows that sulphate acquisition in the meltwaters was controlled by two major processes: 1) coupled-sulphide carbonate weathering (molar ratio ∼ 2) and, 2) re-dissolution of secondary salts (molar ratio ∼ 1). The δ34S-SO4 = +19.4‰ > δ34S-S of rock, accompanied by increased sulphate concentration also indicates an input from re-dissolution of secondary salts. Overall, δ18O composition of these non-snowpack sulphate (-11.9 to -2.2‰) mostly stayed below the threshold δ18O value (-6.7 to -3.3‰) for minimum O2 condition, suggesting that certain proportion of sulphate was regularly supplied from anaerobic sulphide oxidation.

Impact of urbanization on the ecology of Mukuvisi River, Harare, Zimbabwe

NASA Astrophysics Data System (ADS)

Moyo, N. A. G.; Rapatsa, M. M.

2016-04-01

The main objective in this study was to compare the physico-chemical characteristics and biota of a river (Mukuvisi) passing through an urban area to that of a non-urbanised river (Gwebi). Five sites in the Mukuvisi River and five sites in the Gwebi River were sampled for water physico-chemical parameters (pH, conductivity, DO, BOD, TDS, ammonia, Cl, SO42-, PO42-, NO33-, F-, Pb, Cu, Fe, Mn, Zn and Cr) once every month between August, 2012-August, 2013. Cluster analysis based on the physico-chemical parameters grouped the sites into two groups. Mukuvisi River sites formed their own grouping except for one site which was grouped with Gwebi River sites. Principal Component Analysis (PCA) was used to extract the physico-chemical parameters that account for most variations in water quality in the Mukuvisi and Gwebi Rivers. PCA identified sulphate, chloride, fluoride, iron, manganese and zinc as the major factors contributing to the variability of Mukuvisi River water quality. In the Gwebi river, sulphate, nitrate, fluoride and copper accounted for most of the variation in water quality. Canonical Correspondence Analysis (CCA) was used to explore the relationship between physico-chemical parameters and macroinvertebrate communities. CCA plots in both Mukuvisi and Gwebi Rivers showed significant relationships between macroinvertebrate communities and water quality variables. Phosphate, ammonia and nitrates were correlated with Chironomidae and Simulidae. Gwebi River had higher (P < 0.05, ANOVA) macroinvertebrates and fish diversity than Mukuvisi River. Clarias gariepinus from the Mukuvisi River had high liver histological lesions and low AChE activity and this led to lower growth rates in this river.

Antimicrobial activity of flavanoid sulphates and other fractions of Argyreia speciosa (Burm.f) Boj.

PubMed

Habbu, P V; Mahadevan, K M; Shastry, R A; Manjunatha, H

2009-02-01

Antimicrobial activity of flavanoid sulphates and different fractions of A. speciosa root was studied against bacteria, fungi and Mycobacterium tuberculosis H37 Rv sensitive strain by in vitro and in vivo assays. Flavanoid sulphates such as quercetin 3'7 di-O methyl 3- sulphate and kaempferol 7-O methyl 3-sulphate were isolated from the n-butanol fraction of 80% methanolic extract of the plant. The structures of the isolated flavanoids were confirmed by spectral studies. Ethyl acetate (EAAS) fraction and flavanoid sulphates inhibited the growth of M. tuberculosis Rv sensitive strain at MIC values 50 and 25 microg/ml, respectively. Ethanolic fraction (EtAS) showed significant inhibition of gram positive organism with a MIC of 31.25 microg/ml. More inhibition was observed with a less MIC (2 microg/ml) for flavanoid sulphates against Klebsiella pneumoniae, a gram negative organism and it is almost comparable with the standards. Interestingly, chloroform fraction alone exhibited significant antifungal activity with a MIC of 100 microg/ml. A synergistic effect between flavanoids sulphates and commercially available antitubercular drugs was observed with FIC index of 0.443 +/- 0.245, 0.487 +/- 0.247 for isoniazid and 0.468 +/- 0.333, 0.417 +/- 0.345 for rifampicin, whereas EAAS fraction showed partial synergistic effect. A synergistic effect was observed for EAAS fraction and flavanoids sulphates with FIC index < 0.5 with antibiotics. Hemolysis assay on RBCs suggested that EAAS and flavanoids sulphates exhibited least cellular toxicity to erythrocytes as compared to chloramphenicol. In vivo studies in mice infected with K. pneumoniae demonstrated that on day 10 post treatment of different fractions and isolated compounds of A. speciosa, about 60% of the animals treated with EAAS, 70% of animals treated with flavanoids sulphates and 40% of animals treated with EtAS were survived.

Sulphate release from construction and demolition material in soils

NASA Astrophysics Data System (ADS)

Abel, Stefan; Wessolek, Gerd

2013-04-01

In Berlin and many other cities soils are heavily influenced by anthropogenic activities and deposited substrates. A widespread technical substrate in technosols is construction and demolition material from residential and industrial buildings. Existing rubble landfills without sealing facilities pose threats to ground water quality. In the central city of Berlin rising sulphate concentrations of groundwaters (up to 1200 mg/L) are measured since more than two decades. Previous studies point out that the high sulphate concentrations are mainly attributed to World War II rubble. The major part of debris was deposited in form of landfills and contains approximately 0.3 wt% gypsum. The scope of our research is to determine mechanisms of sulphate release from debris material, interactions between sulphate release, soil hydraulic properties and potential sinks of sulphur. To estimate equilibrium concentration and kinetics of sulphate release of various debris components batch and column experiments are conducted. The same method is applied to determine potential adsorptive character of common debris components. To analyse the impacts of soil hydraulic properties on sulphate leaching we carry out soil column experiments with defined upper and lower boundary conditions, varying water flow velocity and induced preferential flow. Simultaneously we monitor sulphate concentration of soil leachate in a 2 m³ lysimeter. First results of the batch experiments show that gypsum from broken stucco is the main source of sulphate in the observed technosols. Other components as mortar and slag show a quite low sulphate release. Similar results are found within the column experiments. For brigs medium and strongly time dependent sulphate release is determined. Concentrations up to 1500 mg/L are measured in the soil leachate from the lysimeter.

Sulphate, more than a nutrient, protects the microalga Chlamydomonas moewusii from cadmium toxicity.

PubMed

Mera, Roi; Torres, Enrique; Abalde, Julio

2014-03-01

Sulphur is an essential macroelement that plays important roles in living organisms. The thiol rich sulphur compounds, such as cysteine, γ-Glu-Cys, glutathione and phytochelatins participate in the tolerance mechanisms against cadmium toxicity. Plants, algae, yeasts and most prokaryotes cover their demand for reduced sulphur by reduction of inorganic sulphate. The aim of this study was to investigate, using a bifactorial experimental design, the effect of different sulphate concentrations in the nutrient solution on cadmium toxicity in the freshwater microalga Chlamydomonas moewusii. Cell growth, kinetic parameters of sulphate utilization and intracellular concentrations of low-molecular mass thiol compounds were determined. A mathematical model to describe the growth of this microalga based on the effects of sulphate and cadmium was obtained. An ANOVA revealed an interaction between them, 16% of the effect sizes was explained by this interaction. A higher amount of sulphate in the culture medium allowed a higher cadmium tolerance due to an increase in the thiol compound biosynthesis. The amount of low-molecular mass thiol compounds, mainly phytochelatins, synthesized by this microalga was significantly dependent on the sulphate and cadmium concentrations; the higher phytochelatin content was obtained in cultures with 4 mg Cd/L and 1mM sulphate. The maximum EC50 value (based on nominal cadmium concentration) reached for this microalga was 4.46 ± 0.42 mg Cd/L when the sulphate concentration added to the culture medium was also 1mM. An increase in the sulphate concentration, in deficient environments, could alleviate the toxic effect of this metal; however, a relative excess is also negative. The results obtained showed a substrate inhibition for this nutrient. An uncompetitive model for sulphate was chosen to establish the mathematical model that links both factors. Copyright © 2014 Elsevier B.V. All rights reserved.

Salting-out assisted liquid-liquid extraction for the determination of biogenic amines in fruit juices and alcoholic beverages after derivatization with 1-naphthylisothiocyanate and high performance liquid chromatography.

PubMed

Jain, Archana; Gupta, Manju; Verma, Krishna K

2015-11-27

A new method for determining biogenic amines in fruit juices and alcoholic beverages is described involving reaction of biogenic amines with 1-naphthylisothiocyanate followed by extraction of 1-naphthylthiourea derivatives with water-miscible organic solvent acetonitrile when solvents phase separation occurred using ammonium sulphate, a process called salting-out assisted liquid-liquid extraction. The extract was analyzed by high-performance liquid chromatography with UV detection at 254nm. The new reagent avoided many of the inconveniences as observed with existing derivatizing agents, such as dansyl chloride and benzoyl chloride, in regard to their inselectivity, instability, adverse effect of excess reagent, and necessity to remove excess reagent. The procedure has been optimized with respect to reaction time and temperature, water-miscible extraction solvent, and salt for solvents phase separation. Use of reagent as dispersed phase in aqueous medium produced derivatives in high yield. A linear calibration was obtained between the amount of biogenic amines in range 1-1000μgL(-1) and peak areas of corresponding thioureas formed; the correlation coefficient was 0.9965, and the limit of detection and limit of quantification found were 1.1μgL(-1) and 3.2μgL(-1), respectively. The pre-concentration method gave an average enrichment factor of 94. The application of the method has been demonstrated in the determination of biogenic amines in commercial samples of fruit juices and alcoholic beverages. In spiking experiments to real samples, the average recovery found by the present method was 94.5% that agreed well with 95.8% obtained by established comparison methods. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis and photophysical properties of aluminium tris-(4-morpholine-8-hydroxyquinoline).

PubMed

Omar, Walaa A E

2013-11-01

Aluminium tris(4-morpholinyl-8-hydroxyquinoline) has been synthesized and characterized. The photoluminescence measurements showed that the new derivative is blue shifted and has relative photoluminescence quantum yield two times higher compared to the pristine Al tris(8-hydroxyquinoline). Deferential scanning colorimetric studies revealed that the newly synthesized Alq3 derivative in this work is amorphous material with the highest transition glass temperature value among the reported amorphous Alq3 derivatives.

A comparison of glycosaminoglycan distributions, keratan sulphate sulphation patterns and collagen fibril architecture from central to peripheral regions of the bovine cornea

PubMed Central

Ho, Leona T.Y.; Harris, Anthony M.; Tanioka, Hidetoshi; Yagi, Naoto; Kinoshita, Shigeru; Caterson, Bruce; Quantock, Andrew J.; Young, Robert D.; Meek, Keith M.

2014-01-01

This study investigated changes in collagen fibril architecture and the sulphation status of keratan sulphate (KS) glycosaminoglycan (GAG) epitopes from central to peripheral corneal regions. Freshly excised adult bovine corneal tissue was examined as a function of radial position from the centre of the cornea outwards. Corneal thickness, tissue hydration, hydroxyproline content, and the total amount of sulphated GAG were all measured. High and low-sulphated epitopes of keratan sulphate were studied by immunohistochemistry and quantified by ELISA. Chondroitin sulphate (CS) and dermatan sulphate (DS) distributions were observed by immunohistochemistry following specific enzyme digestions. Electron microscopy and X-ray fibre diffraction were used to ascertain collagen fibril architecture. The bovine cornea was 1021 ± 5.42 μm thick at its outer periphery, defined as 9–12 mm from the corneal centre, compared to 844 ± 8.10 μm at the centre. The outer periphery of the cornea was marginally, but not significantly, more hydrated than the centre (H = 4.3 vs. H = 3.7), and was more abundant in hydroxyproline (0.12 vs. 0.06 mg/mg dry weight of cornea). DMMB assays indicated no change in the total amount of sulphated GAG across the cornea. Immunohistochemistry revealed the presence of both high- and low-sulphated epitopes of KS, as well as DS, throughout the cornea, and CS only in the peripheral cornea before the limbus. Quantification by ELISA, disclosed that although both high- and low-sulphated KS remained constant throughout stromal depth at different radial positions, high-sulphated epitopes remained constant from the corneal centre to outer-periphery, whereas low-sulphated epitopes increased significantly. Both small angle X-ray diffraction and TEM analysis revealed that collagen fibril diameter remained relatively constant until the outer periphery was reached, after which fibrils became more widely spaced (from small angle x-ray diffraction analysis) and of larger diameter as they approached the sclera. Depth-profiled synchrotron microbeam analyses showed that, at different radial positions from the corneal centre outwards, fibril diameter was greater superficially than in deeper stromal regions. The interfibrillar spacing was also higher at mid-depth in the stroma than it was in anterior and posterior stromal regions. Collagen fibrils in the bovine cornea exhibited a fairly consistent spacing and diameter from the corneal centre to the 12 mm radial position, after which a significant increase was seen. While the constancy of the overall sulphation levels of proteoglycans in the cornea may correlate with the fibrillar architecture, there was no correlation between the latter and the distribution of low-sulphated KS. PMID:25019467

Deleterious Effects From Occupational Exposure to Ethylene Thiourea in Pregnant Women.

PubMed

Mutic, Abby D; Baker, Brenda J; McCauley, Linda A

2017-12-01

Human exposure to endocrine disrupting chemicals (EDCs) has become common as a result of widespread application of these chemicals to the food supply, environmental contamination, and occupational exposures (Caserta et al., 2011). However, relatively little is known about the effects of EDCs such as ethylene thiourea (ETU) in developing fetuses and the lasting implications of this disruption on human development from birth through adulthood. Of highest concern are chronic, low-dose exposures among industrial and agricultural workers. Current knowledge regarding the significance of endocrine thyroid signaling on normal human development raises serious concerns about the possible deleterious effects of EDCs in the developing fetus, children, and mature adults. Occupational health nurses are critical in identifying women and families at increased risk of ETU exposure and mitigating early exposures in pregnancy.

A ditopic colorimetric sensor for fluoride ion based on thiourea mercury complex.

PubMed

Sun, Mei-Zhen; Wu, Fang-Ying; Wu, Yu-Mei; Liu, Wen-Ming

2008-12-01

A novel ditopic chromogenic receptor, N-5-(8-hydroxy)quinoline-N'-4'-nitro-phenyl thiourea (1), was synthesized. The metal complex 1-Hg(2+) showed sensitive and highly selective responses to F(-) over other anions such as CH(3)CO(2)(-), H(2)PO(4)(-), HSO(4)(-) and Cl(-). 1-Hg(2+)-F(-) complex formed, which promoted the intramolecular charge transfer and led to a dramatic spectral change. The color of 1-Hg(2+) solution changed from colorless to red upon addition of F(-). Thus, a colorimetric assay of F(-) was developed in acetonitrile by naked-eye detection. F(-) behaved linearly in the 8.0 x 10(-6) to 2.0 x 10(-5) mol L(-1) concentration range with LOD as 1.4 x 10(-6) mol L(-1).

Molecular docking guided structure based design of symmetrical N,N'-disubstituted urea/thiourea as HIV-1 gp120-CD4 binding inhibitors.

PubMed

Sivan, Sree Kanth; Vangala, Radhika; Manga, Vijjulatha

2013-08-01

Induced fit molecular docking studies were performed on BMS-806 derivatives reported as small molecule inhibitors of HIV-1 gp120-CD4 binding. Comprehensive study of protein-ligand interactions guided in identification and design of novel symmetrical N,N'-disubstituted urea and thiourea as HIV-1 gp120-CD4 binding inhibitors. These molecules were synthesized in aqueous medium using microwave irradiation. Synthesized molecules were screened for their inhibitory ability by HIV-1 gp120-CD4 capture enzyme-linked immunosorbent assay (ELISA). Designed compounds were found to inhibit HIV-1 gp120-CD4 binding in micromolar (0.013-0.247 μM) concentrations. Copyright © 2013 Elsevier Ltd. All rights reserved.

Stable adducts of nerve agents sarin, soman and cyclosarin with TRIS, TES and related buffer compounds--characterization by LC-ESI-MS/MS and NMR and implications for analytical chemistry.

PubMed

Gäb, Jürgen; John, Harald; Melzer, Marco; Blum, Marc-Michael

2010-05-15

Buffering compounds like TRIS are frequently used in chemical, biochemical and biomedical applications to control pH in solution. One of the prerequisites of a buffer compound, in addition to sufficient buffering capacity and pH stability over time, is its non-reactivity with other constituents of the solution. This is especially important in the field of analytical chemistry where analytes are to be determined quantitatively. Investigating the enzymatic hydrolysis of G-type nerve agents sarin, soman and cyclosarin in buffered solution we have identified stable buffer adducts of TRIS, TES and other buffer compounds with the nerve agents. We identified the molecular structure of these adducts as phosphonic diesters using 1D (1)H-(31)P HSQC NMR and LC-ESI-MS/MS techniques. Reaction rates with TRIS and TES are fast enough to compete with spontaneous hydrolysis in aqueous solution and to yield substantial amounts (up to 20-40%) of buffer adduct over the course of several hours. A reaction mechanism is proposed in which the amino function of the buffer serves as an intramolecular proton acceptor rendering the buffer hydroxyl groups nucleophilic enough for attack on the phosphorus atom of the agents. Results show that similar buffer adducts are formed with a range of hydroxyl and amino function containing buffers including TES, BES, TRIS, BIS-TRIS, BIS-TRIS propane, Tricine, Bicine, HEPES and triethanol amine. It is recommended to use alternative buffers like MOPS, MES and CHES when working with G-type nerve agents especially at higher concentrations and over prolonged times. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Synthesis and photophysical properties of aluminium tris-(4-morpholine-8-hydroxyquinoline)

PubMed Central

Omar, Walaa A.E.

2012-01-01

Aluminium tris(4-morpholinyl-8-hydroxyquinoline) has been synthesized and characterized. The photoluminescence measurements showed that the new derivative is blue shifted and has relative photoluminescence quantum yield two times higher compared to the pristine Al tris(8-hydroxyquinoline). Deferential scanning colorimetric studies revealed that the newly synthesized Alq3 derivative in this work is amorphous material with the highest transition glass temperature value among the reported amorphous Alq3 derivatives. PMID:25685461

Electrophoretic Characteristics of Outer Membrane Proteins of Neisseria meningitidis,

DTIC Science & Technology

1987-07-01

chemo-organotropic aerobic or facultative microbes, producing catalase and cytochrome oxidase (Morello and Bohnoff, 1980; Reyn, 1974). These bacteria...resolution, the porosity, pH , and TRIS and glycine concentrations in the stacking and separating gels were investigated. The UNCLASSIFIED UNCLASSIFIED /5...stacking gels were 1.7 cm in length and contained, 0.375 M Tris-HCl ( pH 8.8) and 0.1% SDS. The electrode buffer ( pH 8.3 ) consisted of 0.025 M Tris-HCI

Partially Fluorinated Solvent as a co-solvent for the Non-aqueous Electrolyte of Li/air Battery

DTIC Science & Technology

2010-11-11

ether ( MFE ) and tris(2,2,2-trifluoroethyl) phosphite (TTFP), respectively, as a co-solvent for the non-aqueous electrolyte of Li–air battery. Results...fluorinated solvents on the discharge performance of Li–air bat- tery. For this purpose, we here selectmethyl nonafluorobutyl ether ( MFE ) and tris...196, (2011) pgs. 2867-2870 14. ABSTRACT In this workwestudy methyl nonafluorobutyl ether ( MFE ) and tris(2,2,2-trifluoroethyl) phosphite (TTFP

Electrochemiluminescence aptasensor for adenosine triphosphate detection using host-guest recognition between metallocyclodextrin complex and aptamer.

PubMed

Chen, Hong; Chen, Qiong; Zhao, Yingying; Zhang, Fan; Yang, Fan; Tang, Jie; He, Pingang

2014-04-01

A sensitive and label-free electrochemiluminescence (ECL) aptasensor for the detection of adenosine triphosphate (ATP) was successfully designed using host-guest recognition between a metallocyclodextrin complex, i.e., tris(bipyridine)ruthenium(II)-β-cyclodextrin [tris(bpyRu)-β-CD], and an ATP-binding aptamer. In the protocol, the NH2-terminated aptamer was immobilized on a glassy carbon electrode (GCE) by a coupling interaction. After host-guest recognition between tris(bpyRu)-β-CD and aptamer, the tris(bpyRu)-β-CD/aptamer/GCE produced a strong ECL signal as a result of the photoactive properties of tris(bpyRu)-β-CD. However, in the presence of ATP, the ATP/aptamer complex was formed preferentially, which restricted host-guest recognition, and therefore less tris(bpyRu)-β-CD was attached to the GCE surface, resulting in an obvious decrease in the ECL intensity. Under optimal determination conditions, an excellent logarithmic linear relationship between the ECL decrease and ATP concentration was obtained in the range 10.0-0.05 nM, with a detection limit of 0.01 nM at the S/N ratio of 3. The proposed ECL-based ATP aptasensor exhibited high sensitivity and selectivity, without time-consuming signal-labeling procedures, and is considered to be a promising model for detection of aptamer-specific targets. Copyright © 2014. Published by Elsevier B.V.

Bioelectrochemical sulphate reduction on batch reactors: Effect of inoculum-type and applied potential on sulphate consumption and pH.

PubMed

Gacitúa, Manuel A; Muñoz, Enyelbert; González, Bernardo

2018-02-01

Microbial electrolysis batch reactor systems were studied employing different conditions, paying attention on the effect that biocathode potential has on pH and system performance, with the overall aim to distinguish sulphate reduction from H 2 evolution. Inocula from pure strains (Desulfovibrio paquesii and Desulfobacter halotolerans) were compared to a natural source conditioned inoculum. The natural inoculum possess the potential for sulphate reduction on serum bottles experiments due to the activity of mutualistic bacteria (Sedimentibacter sp. and Bacteroides sp.) that assist sulphate-reducing bacterial cells (Desulfovibrio sp.) present in the consortium. Electrochemical batch reactors were monitored at two different potentials (graphite-bar cathodes poised at -900 and -400mV versus standard hydrogen electrode) in an attempt to isolate bioelectrochemical sulphate reduction from hydrogen evolution. At -900mV all inocula were able to reduce sulphate with the consortium demonstrating superior performance (SO 4 2- consumption: 25.71gm -2 day -1 ), despite the high alkalinisation of the media. At -400mV only the pure Desulfobacter halotolerans inoculated system was able to reduce sulphate (SO 4 2- consumption: 17.47gm -2 day -1 ) and, in this potential condition, pH elevation was less for all systems, confirming direct (or at least preferential) bioelectrochemical reduction of sulphate over H 2 production. Copyright © 2017 Elsevier B.V. All rights reserved.

Neurosteroid dehydroepiandrosterone sulphate inhibits persistent sodium currents in rat medial prefrontal cortex via activation of sigma-1 receptors.

PubMed

Cheng, Zheng-Xiang; Lan, Dan-Mei; Wu, Pei-Ying; Zhu, Yan-Hua; Dong, Yi; Ma, Lan; Zheng, Ping

2008-03-01

Dehydroepiandrosterone sulphate is one of the most important neurosteroids. In the present paper, we studied the effect of dehydroepiandrosterone sulphate on persistent sodium currents and its mechanism and functional consequence with whole-cell patch clamp recording method combined with a pharmacological approach in the rat medial prefrontal cortex slices. The results showed that dehydroepiandrosterone sulphate inhibited the amplitude of persistent sodium currents and the inhibitory effect was significant at 0.1 microM, reached maximum at 1 microM and decreased with the increase in the concentrations of above 1 microM. The effect of dehydroepiandrosterone sulphate on persistent sodium currents was canceled by the Gi protein inhibitor and the protein kinase C inhibitor, but not by the protein kinase A inhibitor. The effect of dehydroepiandrosterone sulphate on persistent sodium currents was also canceled by the sigma-1 receptor blockers and the sigma-1 receptor agonist could mimic the effect of dehydroepiandrosterone sulphate. Dehydroepiandrosterone sulphate had no significant influence on neuronal excitability but could significantly inhibit chemical inhibition of mitochondria-evoked increase in persistent sodium currents. These results suggest that dehydroepiandrosterone sulphate inhibits persistent sodium currents via the activation of sigma-1 receptors-Gi protein-protein kinase C-coupled signaling pathway, and the main functional consequence of this effect of DHEAS is presumably to protect neurons under ischemia.

Microbial interactions in sediment communities.

PubMed

Laanbroek, H J; Veldkamp, H

1982-06-11

Mineralization of organic matter in aquatic ecosystems with shallow waters occurs to a large extent in their sediments under anoxic conditions. This is achieved by a community of bacteria, which are the catalysts in a sequence of processes. Of the two possible terminal processes, methanogenesis and sulphate reduction, the first usually dominates in freshwater systems, whereas in estuarine and marine sediments electrons are mainly channelled to sulphate. Interactions between sulphate-reducing and methanogenic bacteria are described. Sulphate-reducing bacteria also show interactions with fermentative bacteria. After a brief description of properties of sulphate-reducing and fermentative bacteria occurring in sediments, examples are given of interactions between them. This is followed by the presentation of some results obtained from studies on competition for L-lactate between organisms belonging to both groups. It is shown that sulphate-reducing bacteria could successfully compete for L-lactate when this was available in growth-limiting amounts with sufficient sulphate and iron. Finally, a brief discussion is given of ecological niches of sulphide-oxidizing bacteria thriving in the upper sediment layers.

Characteristics and antioxidant of Ulva intestinalis sulphated polysaccharides extracted with different solvents.

PubMed

Peasura, Napassorn; Laohakunjit, Natta; Kerdchoechuen, Orapin; Wanlapa, Sorada

2015-11-01

Ulva intestinalis, a tubular green seaweed, is a rich source of nutrient, especially sulphated polysaccharides. Sulphated polysaccharides from U. intestinalis were extracted with distilled water, 0.1N HCl, and 0.1N NaOH at 80°C for 1, 3, 6, 12, and 24h to study the effect of the extraction solvent and time on their chemical composition and antioxidant activity. Different types of solvents and extraction time had a significant influence on the chemical characteristics and antioxidant activity (p<0.05). Monosaccharide composition and FT-IR spectra analyses revealed that sulphated polysaccharides from all solvent extractions have a typical sugar backbone (glucose, rhamnose, and sulphate attached at C-2 or C-3 of rhamnose). Sulphated polysaccharides extracted with acid exhibited greater antioxidant activity than did those extracted with distilled water and alkali. The results indicated that solvent extraction could be an efficacious method for enhancing antioxidant activity by distinct molecular weight and chemical characteristic of sulphated polysaccharides. Copyright © 2015 Elsevier B.V. All rights reserved.

Use of 16S rRNA-targeted oligonucleotide probes to investigate the distribution of sulphate-reducing bacteria in estuarine sediments.

PubMed

Purdy, K J.; Nedwell, D B.; Embley, T M.; Takii, S

2001-07-01

The distribution of sulphate-reducing bacteria (SRBs) in three anaerobic sediments, one predominantly freshwater and low sulphate and two predominantly marine and high sulphate, on the River Tama, Tokyo, Japan, was investigated using 16S rRNA-targeted oligonucleotide probes. Hybridisation results and sulphate reduction measurements indicated that SRBs are a minor part of the bacterial population in the freshwater sediments. Only Desulfobulbus and Desulfobacterium were detected, representing 1.6% of the general bacterial probe signal. In contrast, the SRB community detected at the two marine-dominated sites was larger and more diverse, representing 10-11.4% of the bacterial signal and with Desulfobacter, Desulfovibrio, Desulfobulbus and Desulfobacterium detected. In contrast to previous reports our results suggest that Desulfovibrio may not always be the most abundant SRB in anaerobic sediments. Acetate-utilising Desulfobacter were the dominant SRB in the marine-dominated sediments, and Desulfobulbus and Desulfobacterium were active in low-sulphate sediments, where they may utilise electron acceptors other than sulphate.

Sulphate absorption across biological membranes.

PubMed

Mitchell, Stephen C; Waring, Rosemary H

2016-01-01

1. Sulphonation is unusual amongst the common Phase II (condensation; synthetic) reactions experienced by xenobiotics, in that the availability of the conjugating agent, sulphate, may become a rate-limiting factor. This sulphate is derived within the body via the oxygenation of sulphur moieties liberated from numerous ingested compounds including the sulphur-containing amino acids. Preformed inorganic sulphate also makes a considerable contribution to this pool. 2. There has been a divergence of opinion as to whether or not inorganic sulphate may be readily absorbed from the gastrointestinal tract and this controversy still continues in some quarters. Even more so, is the vexing question of potential absorption of inorganic sulphate via the lungs and through the skin. 3. This review examines the relevant diverse literature and concludes that sulphate ions may move across biological membranes by means of specific transporters and, although the gastrointestinal tract is by far the major portal of entry, some absorption across the lungs and the skin may take place under appropriate circumstances.

Electrogenerated chemiluminescence of tris(2,2' bipyridine)ruthenium(II) using common biological buffers as co-reactant, pH buffer and supporting electrolyte.

PubMed

Kebede, Noah; Francis, Paul S; Barbante, Gregory J; Hogan, Conor F

2015-11-07

A series of aliphatic tertiary amines (HEPES, POPSO, EPPS and BIS-TRIS) commonly used to buffer the pH in biological experiments, were examined as alternative, non-toxic co-reactants for the electrogenerated chemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(ii) ([Ru(bpy)3](2+)). These were found to be very attractive as "multi-tasking" reagents, serving not only as co-reactants, but also fulfiling the roles of pH buffer and supporting electrolyte within an aqueous environment; thus significantly simplifying the overall ECL analysis. Sub-nanomolar detection limits were obtained for [Ru(bpy)3](2+) in the presence of BIS-TRIS, making this species an valuable option for co-reactant ECL-based bioanalytical applications.

Preparation of the 3-monosulphates of cholic acid, chenodeoxycholic acid and deoxycholic acid.

PubMed Central

Haslewood, E S; Haslewood, G A

1976-01-01

1. The 3-sulphates of cholic, chenodeoxycholic and deoxycholic acids were prepared as crystalline disodium salts. 2. The method described shows that it is possible to prepare specific sulphate esters of polyhydroxy bile acids and to remove protecting acyl groups without removing the sulphate. 3. A study of bile acid sulphate solvolysis showed that none of the usual methods give the original bile acid in major yield in a single step. 4. An understanding of the preparation, properties and methods of solvolysis of bile acid sulphates is basic for investigations of cholestasis and liver disease. PMID:938488

Particulate sulphate and ozone in rural air: Preliminary results from three sites in central England

NASA Astrophysics Data System (ADS)

Martin, A.; Barber, F. R.

Daily particulate sulphate concentrations in air have been measured at a 'background' rural site and at two other sites near rural power stations. The samples were collected by drawing air through filter papers and were analysed by X-ray fluorescence. At the background site the concentration of particulate sulphates was strongly dependent on the O 3 and total S in air. Above a certain 'critical' level of daily O 3, 28% of the daily S in air was particulate on average, but the amounts were not related to the actual O 3 levels. At lower O 3 levels, there appeared to be a constant background of about 2 μg of particulate sulphate per cubic meter of air, together with about 5% of the total S in air as particulate. When black smoke in air was low, the particulate sulphate was also low, despite the O 3 levels. Near the power stations, there was no significantly different rate of production or loss of particulate sulphate. On average, at all three sites over the year, about 12% of the daily total S was particulate, probably corresponding to an average conversion rate of SO 2 of less than 1% per hour. Estimates of hourly particulate sulphates are available from previous measurements at the background site, using a different analysis technique. Particulate sulphate was not found every hour, but typically during 20 h a day in early summer and 8 h a day in early winter. An influence of humidity as well as O 3 was apparent in the peak hourly particulate sulphate values, which reached 60% of the total S. No correlation could be found of particulate sulphate with solar radiation, wind direction, concentrations of oxides of nitrogen in air or ammonium or sulphate in rainwater, but further measurements are planned.

THE PRODUCTION OF HYDROGEN PEROXIDE BY HIGH OXYGEN PRESSURES

PubMed Central

Gilbert, Daniel L.; Gerschman, Rebeca; Ruhm, K. Barclay; Price, William E.

1958-01-01

Hydrogen peroxide is formed in solutions of glutathione exposed to oxygen. This hydrogen peroxide or its precursors will decrease the viscosity of polymers like desoxyribonucleic acid and sodium alginate. Further knowledge of the mechanism of these chemical effects of oxygen might further the understanding of the biological effects of oxygen. This study deals with the rate of solution of oxygen and with the decomposition of hydrogen peroxide in chemical systems exposed to high oxygen pressures. At 6 atmospheres, the absorption coefficient for oxygen into water was about 1 cm./hour and at 143 atmospheres, it was about 2 cm./hour; the difference probably being due to the modus operandi. The addition of cobalt (II), manganese (II), nickel (II), or zinc ions in glutathione (GSH) solutions exposed to high oxygen pressure decreased the net formation of hydrogen peroxide and also the reduced glutathione remaining in the solution. Studies on hydrogen peroxide decomposition indicated that these ions act probably by accelerating the hydrogen perioxide oxidation of glutathione. The chelating agent, ethylenediaminetetraacetic acid disodium salt, inhibited the oxidation of GSH exposed to high oxygen pressure for 14 hours. However, indication that oxidation still occurred, though at a much slower rate, was found in experiments lasting 10 weeks. Thiourea decomposed hydrogen peroxide very rapidly. When GSH solutions were exposed to high oxygen pressure, there was oxidation of the GSH, which became relatively smaller with increasing concentrations of GSH. PMID:13525677

Quantification of 19-nortestosterone sulphate and boldenone sulphate in urine from male horses using liquid chromatography/tandem mass spectrometry.

PubMed

Grace, Philip B; Drake, Erica C; Teale, Philip; Houghton, Edward

2008-10-01

Following administration of the anabolic steroid 19-nortestosterone or its esters to the horse, a major urinary metabolite is 19-nortestosterone-17beta-sulphate. The detection of 19-nortestosterone in urine from untreated animals has led to it being considered a naturally occurring steroid in the male horse. Recently, we have demonstrated that the majority of the 19-nortestosterone found in extracts of 'normal' urine from male horses arises as an artefact through decarboxylation of the 19-carboxylic acid of testosterone. The aim of this investigation was to establish if direct analysis of 19-nortestosterone-17beta-sulphate by liquid chromatography/tandem mass spectrometry (LC/MS/MS) had potential for the detection of 19-nortestosterone misuse in the male horse. The high concentrations of sulphate conjugates of the female sex hormones naturally present in male equine urine were overcome by selective hydrolysis of the aryl sulphates using glucuronidase from Helix pomatia; this was shown to have little or no activity for alkyl sulphates such as 19-nortestosterone-17beta-sulphate. The 'free' phenolic steroids were removed by solid-phase extraction (SPE) prior to LC/MS/MS analysis. The method also allowed for the quantification of the sulphate conjugate of boldenone, a further anabolic steroid endogenous in the male equine with potential for abuse in sports. The method was applied to the quantification of these analytes in a population of samples. This paper reports the results of that study along with the development and validation of the LC/MS/MS method. The results indicate that while 19-nortestosterone-17beta-sulphate is present at low levels as an endogenous substance in urine from 'normal' male horses, its use as an effective threshold substance may be viable.

Iron and gallium increase iron uptake from transferrin by human melanoma cells: further examination of the ferric ammonium citrate-activated iron uptake process.

PubMed

Richardson, D R

2001-04-30

Previously we showed that preincubation of cells with ferric ammonium citrate (FAC) resulted in a marked increase in Fe uptake from both (59)Fe-transferrin (Tf) and (59)Fe-citrate (D.R. Richardson, E. Baker, J. Biol. Chem. 267 (1992) 13972-13979; D.R. Richardson, P. Ponka, Biochim. Biophys. Acta 1269 (1995) 105-114). This Fe uptake process was independent of the transferrin receptor and appeared to be activated by free radicals generated via the iron-catalysed Haber-Weiss reaction. To further understand this process, the present investigation was performed. In these experiments, cells were preincubated for 3 h at 37 degrees C with FAC or metal ion solutions and then labelled for 3 h at 37 degrees C with (59)Fe-Tf. Exposure of cells to FAC resulted in Fe uptake from (59)Fe-citrate that became saturated at an Fe concentration of 2.5 microM, while FAC-activated Fe uptake from Tf was not saturable up to 25 microM. In addition, the extent of FAC-activated Fe uptake from citrate was far greater than that from Tf. These results suggest a mechanism where FAC-activated Fe uptake from citrate may result from direct interaction with the transporter, while Fe uptake from Tf appears indirect and less efficient. Preincubation of cells with FAC at 4 degrees C instead of 37 degrees C prevented its effect at stimulating (59)Fe uptake from (59)Fe-Tf, suggesting that an active process was involved. Previous studies by others have shown that FAC can increase ferrireductase activity that may enhance (59)Fe uptake from (59)Fe-Tf. However, there was no difference in the ability of FAC-treated cells compared to controls to reduce ferricyanide to ferrocyanide, suggesting no change in oxidoreductase activity. To examine if activation of this Fe uptake mechanism could occur by incubation with a range of metal ions, cells were preincubated with either FAC, ferric chloride, ferrous sulphate, ferrous ammonium sulphate, gallium nitrate, copper chloride, zinc chloride, or cobalt chloride. Stimulation of (59)Fe uptake from Tf was shown (in order of potency) with ferric chloride, ferrous sulphate, ferrous ammonium sulphate, and gallium nitrate. The other metal ions examined decreased (59)Fe uptake from Tf. The fact that redox-active Cu(II) ion did not stimulate Fe uptake while redox-inactive Ga(III) did, suggests a mechanism of transporter activation not solely dependent on free radical generation. Indeed, the activation of Fe uptake appears dependent on the presence of the Fe atom itself or a metal ion with atomic similarities to Fe (e.g. Ga).

An Efficient Composition for Bengal Lights.

ERIC Educational Resources Information Center

Comet, M.; Schreyeck, L.; Fuzellier, H.

2002-01-01

Reports the discovery of an efficient base composition for making bengal lights that is obtained with potassium chlorate and thiourea. Combining this mixture with appropriate flame coloring can produce several impressive bengal lights. (DDR)

A thiourea-appended rhodamine chemodosimeter for mercury(II) and its bioimaging application

NASA Astrophysics Data System (ADS)

Tantipanjaporn, Ajcharapan; Prabpai, Samran; Suksen, Kanoknetr; Kongsaeree, Palangpon

2018-03-01

A rhodamine-thiourea conjugate RTP with an o-phenylenediamine linker was developed as a fluorogenic chemodosimeter for Hg2+ detection. In the presence of Hg2+, a colorless solution of RTP turned pink with a maximum absorption band at 555 nm and with a 62-fold fluorescence enhancement at 578 nm (Φ = 0.34). RTP is highly selective to Hg2+ among other metal ions with a detection limit of 1.6 nM (0.3 ppb). A similar rhodamine analog with a flexible ethylenediamine spacer was less selective and less sensitive than RTP. Hg2+ induced cyclic guanylation to yield a benzimidazole moiety and a subsequent ring-opening of the spirolactam unit resulted in chromogenic and fluorogenic changes. The membrane-permeable RTP probe was successfully demonstrated in monitoring of Hg2+ in cultured HeLa cells.

Co-reductive fabrication of carbon nanodots with high quantum yield for bioimaging of bacteria

PubMed Central

Wang, Jiajun; Liu, Xia; Milcovich, Gesmi; Chen, Tzu-Yu; Durack, Edel; Mallen, Sarah; Ruan, Yongming

2018-01-01

A simple and straightforward synthetic approach for carbon nanodots (C-dots) is proposed. The strategy is based on a one-step hydrothermal chemical reduction with thiourea and urea, leading to high quantum yield C-dots. The obtained C-dots are well-dispersed with a uniform size and a graphite-like structure. A synergistic reduction mechanism was investigated using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The findings show that using both thiourea and urea during the one-pot synthesis enhances the luminescence of the generated C-dots. Moreover, the prepared C-dots have a high distribution of functional groups on their surface. In this work, C-dots proved to be a suitable nanomaterial for imaging of bacteria and exhibit potential for application in bioimaging thanks to their low cytotoxicity. PMID:29441259

Synthesis and antimalarial activity of new 4-amino-7-chloroquinolyl amides, sulfonamides, ureas and thioureas.

PubMed

Ekoue-Kovi, Kekeli; Yearick, Kimberly; Iwaniuk, Daniel P; Natarajan, Jayakumar K; Alumasa, John; de Dios, Angel C; Roepe, Paul D; Wolf, Christian

2009-01-01

We report the synthesis and in vitro antimalarial activities of more than 50 7-chloro-4-aminoquinolyl-derived sulfonamides 3-8 and 11-26, ureas 19-22, thioureas 23-26, and amides 27-54. Many of the CQ analogues prepared for this study showed submicromolar antimalarial activity versus HB3 (chloroquine sensitive) and Dd2 (chloroquine resistant strains of Plasmodium falciparum) and low resistance indices were obtained in most cases. Systematic variation of the side chain length and introduction of fluorinated aliphatic and aromatic termini revealed promising leads that overcome CQ resistance. In particular, sulfonamide 3 exhibiting a short side chain with a terminal dansyl moiety combined high antiplasmodial potency with a low resistance index and showed IC(50)s of 17.5 and 22.7 nM against HB3 and Dd2 parasites.

Biasing hydrogen bond donating host systems towards chemical warfare agent recognition.

PubMed

Hiscock, Jennifer R; Wells, Neil J; Ede, Jayne A; Gale, Philip A; Sambrook, Mark R

2016-10-12

A series of neutral ditopic and negatively charged, monotopic host molecules have been evaluated for their ability to bind chloride and dihydrogen phosphate anions, and neutral organophosphorus species dimethyl methylphosphonate (DMMP), pinacolyl methylphosphonate (PMP) and the chemical warfare agent (CWA) pinacolyl methylphosphonofluoridate (GD, soman) in organic solvent via hydrogen bonding. Urea, thiourea and boronic acid groups are shown to bind anions and neutral guests through the formation of hydrogen bonds, with the urea and thiourea groups typically exhibiting higher affinity interactions. The introduction of a negative charge on the host structure is shown to decrease anion affinity, whilst still allowing for high stability host-GD complex formation. Importantly, the affinity of the host for the neutral CWA GD is greater than for anionic guests, thus demonstrating the potential for selectivity reversal based on charge repulsion.

Morphological and structural studies of CBD-CdS thin films by microscopy and diffraction techniques

NASA Astrophysics Data System (ADS)

Martínez, M. A.; Guillén, C.; Herrero, J.

1998-10-01

The influence of cadmium salt and thiourea concentrations on the morphological and structural properties of chemical bath-deposited CdS thin films has been investigated. Two different feature regimes have been distinguished: an inner continuous layer grown directly on the glass and independent on the deposition conditions, and other porous overlayer, more dependent on the chemical concentrations. Root mean square, RMS, and average roughnesses, Ra, as quantified by AFM, are about 10-13 nm and 7-11 nm, respectively, for all CdS samples tested. These films are sulphur-poor, decreasing S/Cd atomic ratio from 0.82 at low cadmium salt, 1 mM, and high thiourea concentrations, 100 mM, down to 0.76 at higher [Cd 2+], 5 mM, and lower [TU], 10 mM.

Synthesis, characterization, cytotoxicity, cell cycle analysis of 3-(4-methoxyphenyl)-1-(pyridin-2-ylmethyl)thiourea and quantum chemical analyses

NASA Astrophysics Data System (ADS)

Mushtaque, Md.; Avecilla, Fernando; Khan, Md. Shahzad; Hafeez, Zubair Bin; Rezvi, M. Moshahid A.; Srivastava, Anurag

2017-08-01

Thiourea derivative,3-(4-methoxyphenyl)-1-(pyridin-2-ylmethyl)thiourea, was synthesized. The structure of the synthesized compound (3) was elucidated by IR, UV-visible, 1H NMR, mass Spectrometry, and X-ray single crystal structure. The computational quantum chemical studies like, IR, UV, NBO analysis were performed by DFT with Becke-3-Lee-Yang- Parr (B3LYP) exchange-correlation functional in combination with 6-311++G(d,p) basis sets. It was observed experimentally and theoretically that compound (3) exhibited syn-anti-conformation around sulphur atom. The DNA-binding constant Kb was found 3.3 × 106 Lmol-1. The docking energy of compound (3) with 1BNA was found -6.2 kcal/mol. MTT-assay against HepG2 (IC50 = 140.39) and Siha (IC50 = 119.87 μM) cell lines revealed that compound (3) wasnon-toxic up to140.39 μM against HepG2 and 119.87 μM against Siha cells respectively. It was also found that compound (3) is non-toxic against normal human cell line HEK-293(IC50 = 148.67 μM). Cell cycle analyses displayed that treated HepG2 cells at 40 μM and 80 μM showed 65% and 70% arrest in G0/G1with respect to untreated controls (60%) and Siha cells at the same concentration displayed 59% and 65% arrest with respect to G0/G1 as compared to untreated control (45%).

X-ray Studies of Regenerated Cellulose Fibers Wet Spun from Cotton Linter Pulp in NaOH/Thiourea Aqueous Solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen,X.; Burger, C.; Fang, D.

Regenerated cellulose fibers were fabricated by dissolution of cotton linter pulp in NaOH (9.5 wt%) and thiourea (4.5 wt%) aqueous solution followed by wet-spinning and multi-roller drawing. The multi-roller drawing process involved three stages: coagulation (I), coagulation (II) and post-treatment (III). The crystalline structure and morphology of regenerated cellulose fiber was investigated by synchrotron wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) techniques. Results indicated that only the cellulose II crystal structure was found in regenerated cellulose fibers, proving that the cellulose crystals were completely transformed from cellulose I to II structure during spinning from NaOH/thiourea aqueous solution. Themore » crystallinity, orientation and crystal size at each stage were determined from the WAXD analysis. Drawing of cellulose fibers in the coagulation (II) bath (H{sub 2}SO{sub 4}/H{sub 2}O) was found to generate higher orientation and crystallinity than drawing in the post-treatment (III). Although the post-treatment process also increased crystal orientation, it led to a decrease in crystallinity with notable reduction in the anisotropic fraction. Compared with commercial rayon fibers fabricated by the viscose process, the regenerated cellulose fibers exhibited higher crystallinity but lower crystal orientation. SAXS results revealed a clear scattering maximum along the meridian direction in all regenerated cellulose fibers, indicating the formation of lamellar structure during spinning.« less

Effect of sulfur source on photocatalytic degradation performance of CdS/MoS2 prepared with one-step hydrothermal synthesis.

PubMed

Wang, Yanfeng; Chen, Wei; Chen, Xiao; Feng, Huajun; Shen, Dongsheng; Huang, Bin; Jia, Yufeng; Zhou, Yuyang; Liang, Yuxiang

2018-03-01

CdS/MoS 2 , an extremely efficient photocatalyst, has been extensively used in hydrogen photoproduction and pollutant degradation. CdS/MoS 2 can be synthesized by a facile one-step hydrothermal process. However, the effect of the sulfur source on the synthesis of CdS/MoS 2 via one-step hydrothermal methods has seldom been investigated. We report herein a series of one-step hydrothermal preparations of CdS/MoS 2 using three different sulfur sources: thioacetamide, l-cysteine, and thiourea. The results revealed that the sulfur source strongly affected the crystallization, morphology, elemental composition and ultraviolet (UV)-visible-light-absorption ability of the CdS/MoS 2 . Among the investigated sulfur sources, thioacetamide provided the highest visible-light absorption ability for CdS/MoS 2 , with the smallest average particle size and largest surface area, resulting in the highest efficiency in Methylene Blue (MB) degradation. The photocatalytic activity of CdS/MoS 2 synthesized from the three sulfur sources can be arranged in the following order: thioacetamide>l-cysteine>thiourea. The reaction rate constants (k) for thioacetamide, l-cysteine, and thiourea were estimated to be 0.0197, 0.0140, and 0.0084min -1 , respectively. However, thioacetamide may be limited in practical application in terms of its price and toxicity, while l-cysteine is relatively economical, less toxic and exhibited good photocatalytic degradation performance toward MB. Copyright © 2017. Published by Elsevier B.V.

Redox-switchable copper(I) metallogel: a metal-organic material for selective and naked-eye sensing of picric acid.

PubMed

Sarkar, Sougata; Dutta, Soumen; Chakrabarti, Susmita; Bairi, Partha; Pal, Tarasankar

2014-05-14

Thiourea (TU), a commercially available laboratory chemical, has been discovered to introduce metallogelation when reacted with copper(II) chloride in aqueous medium. The chemistry involves the reduction of Cu(II) to Cu(I) with concomitant oxidation of thiourea to dithiobisformamidinium dichloride. The gel formation is triggered through metal-ligand complexation, i.e., Cu(I)-TU coordination and extensive hydrogen bonding interactions involving thiourea, the disulfide product, water, and chloride ions. Entangled network morphology of the gel selectively develops in water, maybe for its superior hydrogen-bonding ability, as accounted from Kamlet-Taft solvent parameters. Complete and systematic chemical analyses demonstrate the importance of both Cu(I) and chloride ions as the key ingredients in the metal-organic coordination gel framework. The gel is highly fluorescent. Again, exclusive presence of Cu(I) metal centers in the gel structure makes the gel redox-responsive and therefore it shows reversible gel-sol phase transition. However, the reversibility does not cause any morphological change in the gel phase. The gel practically exhibits its multiresponsive nature and therefore the influences of different probable interfering parameters (pH, selective metal ions and anions, selective complexing agents, etc.) have been studied mechanistically and the results might be promising for different applications. Finally, the gel material shows a highly selective visual response to a commonly used nitroexplosive, picric acid among a set of 19 congeners and the preferred selectivity has been mechanistically interpreted with density functional theory-based calculations.

Vibrational spectroscopic study of sulphated silk proteins

NASA Astrophysics Data System (ADS)

Monti, P.; Freddi, G.; Arosio, C.; Tsukada, M.; Arai, T.; Taddei, P.

2007-05-01

Degummed Bombyx mori ( B. m.) silk fibroin fabric and mutant naked pupa cocoons (Nd-s) consisting of almost pure silk sericin were treated with chlorosulphonic acid in pyridine and investigated by FT-IR and FT-Raman spectroscopies. Untreated silk fibroin and sericin displayed typical spectral features due to characteristic amino acid composition and molecular conformation (prevailing β-sheet with a less ordered structure in sericin). Upon sulphation, the degree of molecular disorder increased in both proteins and new bands appeared. The IR bands at 1049 and 1014 cm -1 were attributed to vibrations of sulphate salts and that at 1385 cm -1 to the νasSO 2 mode of organic covalent sulphates. In the 1300-1180 cm -1 range various contributions of alkyl and aryl sulphate salts, sulphonamides, sulphoamines and organic covalent sulphates, fell. Fibroin covalently bound sulphate groups through the hydroxyl groups of tyrosine and serine, while sericin through the hydroxyl groups of serine, since the δOH vibrations at 1399 cm -1 in IR and at 1408 cm -1 in Raman disappeared almost completely. Finally, the increase of the I850/ I830 intensity ratio of Raman tyrosine doublet in fibroin suggested a change towards a more exposed state of tyrosine residues, in good agreement with the more disordered conformation taken upon sulphation.

The degradation of intravenously injected chondroitin 4-sulphate in the rat

PubMed Central

Wood, Keith M.; Wusteman, Frederick S.; Curtis, C. Gerald

1973-01-01

The degradation of chondroitin 4-[35S]sulphate isolated from chick-embryo cartilage was studied in the rat by experiments on free-range animals, on wholly anaesthetized animals with ureter cannulae, by perfusion of isolated liver, by whole-body radioautography and by isolation of liver lysosomes. After injection into rats 68% of the radioactivity was recovered in the urine after 24h, approximately one-half of this being in the form of low-molecular-weight material, chiefly inorganic sulphate. Cannulation experiments demonstrated that the proportion of low-molecular-weight components excreted in the urine increased with time until, after 12h, virtually all was inorganic sulphate. Whole-body radioautography identified the liver as the major site of radioisotope accumulation after injection of labelled polysaccharide. Perfusion through isolated liver indicated that this organ has the ability to metabolize the polymer with the release of low-molecular-weight products, principally inorganic sulphate. Incubation of a lysosomal fraction prepared from rat liver after injection of chondroitin 4-[35S]sulphate gave rise to degradation products of low molecular weight, and experiments in vitro with rat liver lysosomes confirmed that these organelles are capable of the entire degradative process from chondroitin sulphate to free inorganic sulphate. ImagesPLATE 1 PMID:4762749

Administration of magnesium sulphate before rocuronium: effects on speed of onset and duration of neuromuscular block.

PubMed

Kussman, B; Shorten, G; Uppington, J; Comunale, M E

1997-07-01

The speeds of onset of pancuronium, atracurium and vecuronium are increased by prior administration of magnesium sulphate. A prospective, randomized, double-blind, controlled, clinical study was performed to examine the effects of prior i.v. administration of magnesium sulphate 60 mg kg-1 on the neuromuscular blocking effects of rocuronium 0.6 mg kg-1 during isoflurane anaesthesia. Neuromuscular function was measured electromyographically (Relaxograph) in 30 patients who received either magnesium sulphate 60 mg kg-1 or normal saline, 1-min before rocuronium 0.6 mg kg-1. Mean onset times were similar in the two groups (magnesium sulphate 71 (SD 20) s; normal saline 75 (23) s), but times to initial, 10% and 25% recovery from neuromuscular block were significantly longer in the magnesium sulphate group (42.1 (16.3), 49.0 (12.4) and 56.5 (13.2) min, respectively) than in the saline group (25.1 (9.1), 33.0 (11.1) and 35.6 (13.2) min, respectively) (P < 0.05 in all three cases). Administration of magnesium sulphate was not associated with adverse haemodynamic effects. Prior administration of magnesium sulphate, under the study conditions described, prolonged rocuronium-induced neuromuscular block but did not increase speed of onset.

Carbon isotope equilibration during sulphate-limited anaerobic oxidation of methane

NASA Astrophysics Data System (ADS)

Yoshinaga, Marcos Y.; Holler, Thomas; Goldhammer, Tobias; Wegener, Gunter; Pohlman, John W.; Brunner, Benjamin; Kuypers, Marcel M. M.; Hinrichs, Kai-Uwe; Elvert, Marcus

2014-03-01

Collectively, marine sediments comprise the largest reservoir of methane on Earth. The flux of methane from the sea bed to the overlying water column is mitigated by the sulphate-dependent anaerobic oxidation of methane by marine microbes within a discrete sedimentary horizon termed the sulphate-methane transition zone. According to conventional isotope systematics, the biological consumption of methane leaves a residue of methane enriched in 13C (refs , , ). However, in many instances the methane within sulphate-methane transition zones is depleted in 13C, consistent with the production of methane, and interpreted as evidence for the intertwined anaerobic oxidation and production of methane. Here, we report results from experiments in which we incubated cultures of microbial methane consumers with methane and low levels of sulphate, and monitored the stable isotope composition of the methane and dissolved inorganic carbon pools over time. Residual methane became progressively enriched in 13C at sulphate concentrations above 0.5 mM, and progressively depleted in 13C below this threshold. We attribute the shift to 13C depletion during the anaerobic oxidation of methane at low sulphate concentrations to the microbially mediated carbon isotope equilibration between methane and carbon dioxide. We suggest that this isotopic effect could help to explain the 13C-depletion of methane in subseafloor sulphate-methane transition zones.

Anthropogenic influence on the distribution of tropospheric sulphate aerosol

NASA Astrophysics Data System (ADS)

Langner, J.; Rodhe, H.; Crutzen, P. J.; Zimmermann, P.

1992-10-01

HUMAN activities have increased global emissions of sulphur gases by about a factor of three during the past century, leading to increased sulphate aerosol concentrations, mainly in the Northern Hemisphere. Sulphate aerosols can affect the climate directly, by increasing the backscattering of solar radiation in cloud-free air, and indirectly, by providing additional cloud condensation nuclei1-4. Here we use a global transport-chemistry model to estimate the changes in the distribution of tropospheric sulphate aerosol and deposition of non-seasalt sulphur that have occurred since pre-industrial times. The increase in sulphate aerosol concentration is small over the Southern Hemisphere oceans, but reaches a factor of 100 over northern Europe in winter. Our calculations indicate, however, that at most 6% of the anthropogenic sulphur emissions is available for the formation of new aerosol particles. This is because about one-half of the sulphur dioxide is deposited on the Earth's surface, and most of the remainder is oxidized in cloud droplets so that the sulphate becomes associated with pre-existing particles. Even so, the rate of formation of new sulphate particles may have doubled since pre-industrial times.

The contamination of rain samples by dry deposition on rain collectors

NASA Astrophysics Data System (ADS)

Fowler, D.; Cape, J. N.

A series of short-term experiments at a rural site in eastern Scotland showed that dry deposition of SO 2 gas onto pyrex glass rain collectors in dry weather approached saturation after 24 h and contributed c. 80 % of dry-deposited S, the remaining 20 % being attributable to Particulate sulphate. A comparison over 3 years of soluble sulphate from funnel washings after dry days with daily concentrations of SO 2 and particulate sulphate was well fitted by a linear dependence on Particulate sulphate and a logarithmic dependence on SO 2 concentrations. Particulate sulphate contributed 34 (+- 7) % of the dry deposition on dry days, although there was a marked seasonal variation in the total dry deposit of S on the collector which was independent of SO 2 and particulate sulphate concentrations. A comparison of monthly and daily collectors at the same site from April to September was consistent with these estimates of dry deposition on dry days. An extrapolation to sites with similar collectors in northern Britain showed that between 1S and 35 % of the monthly collected non-marine sulphate could have been dry-deposited on the collector.

Zinc Tantalum Oxynitride (ZnTaO2N) Photoanode Modified with Cobalt Phosphate Layers for the Photoelectrochemical Oxidation of Alkali Water

PubMed Central

T. Weller, Mark

2018-01-01

Photoanodes fabricated by the electrophoretic deposition of a thermally prepared zinc tantalum oxynitride (ZnTaO2N) catalyst onto indium tin oxide (ITO) substrates show photoactivation for the oxygen evolution reaction (OER) in alkaline solutions. The photoactivity of the OER is further boosted by the photodeposition of cobalt phosphate (CoPi) layers onto the surface of the ZnTaO2N photoanodes. Structural, morphological, and photoelectrochemical (PEC) properties of the modified ZnTaO2N photoanodes are studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet visible (UV−Vis) diffuse reflectance spectroscopy, and electrochemical techniques. The presence of the CoPi layer significantly improved the PEC performance of water oxidation in an alkaline sulphate solution. The photocurrent-voltage behavior of the CoPi-modified ZnTaO2N anodes was improved, with the influence being more prominent at lower oxidation potentials. A stable photocurrent density of about 2.3 mA·cm−2 at 1.23 V vs. RHE was attained upon visible light illumination. Relative to the ZnTaO2N photoanodes, an almost three-fold photocurrent increase was achieved at the CoPi/ZnTaO2N photoelectrode. Perovskite-based oxynitrides are modified using an oxygen-evolution co-catalyst of CoPi, and provide a new dimension for enhancing the photoactivity of oxygen evolution in solar-assisted water-splitting reactions. PMID:29346306

DNA stretching on the wall surfaces in curved microchannels with different radii

NASA Astrophysics Data System (ADS)

Hsieh, Shou-Shing; Wu, Fong-He; Tsai, Ming-Ju

2014-08-01

DNA molecule conformation dynamics and stretching were made on semi-circular surfaces with different radii (500 to 5,000 μm) in microchannels measuring 200 μm × 200 μm in cross section. Five different buffer solutions - 1× Tris-acetate-EDTA (TAE), 1× Tris-borate-EDTA (TBE), 1× Tris-EDTA (TE), 1× Tris-phosphate-EDTA (TPE), and 1× Tris-buffered saline (TBS) solutions - were used with a variety of viscosity such as 40, 60, and 80 cP, with resultant 10-4 ≤ Re ≤ 10-3 and the corresponding 5 ≤ Wi ≤ 12. The test fluids were seeded with JOJO-1 tracer particles for flow visualization and driven through the test channels via a piezoelectric (PZT) micropump. Micro particle image velocimetry (μPIV) measuring technique was applied for the centered-plane velocity distribution measurements. It is found that the radius effect on the stretch ratio of DNA dependence is significant. The stretch ratio becomes larger as the radius becomes small due to the larger centrifugal force. Consequently, the maximum stretch was found at the center of the channel with a radius of 500 μm.

Deep aquifer as driver for mineral authigenesis in Gulf of Alaska sediments (IODP Expedition 341, Site U1417)

NASA Astrophysics Data System (ADS)

Zindorf, Mark; März, Christian; Wagner, Thomas; Strauss, Harald; Gulick, Sean P. S.; Jaeger, John M.; LeVay, Leah J.

2016-04-01

Bacterial sulphate reduction plays a key role in authigenic mineral formation in marine sediments. Usually, decomposition of organic matter follows a sequence of microbial metabolic pathways, where microbial sulphate reduction leads to sulphate depletion deeper in the sediment. When sulphate is consumed completely from the pore waters, methanogenesis commences. The contact of sulphate- and methane-containing pore waters is a well-defined biogeochemical boundary (the sulphate-methane transition zone, SMTZ). Here authigenic pyrite, barite and carbonates form. Pyrite formation is directly driven by bacterial sulphate reduction since pyrite precipitates from produced hydrogen sulphide. Barite and carbonate formation are secondary effects resulting from changes of the chemical milieu due to microbial activity. However, this mineral authigenesis is ultimately linked to abiotic processes that determine the living conditions for microorganisms. At IODP Site U1417 in the Gulf of Alaska, a remarkable diagenetic pattern has been observed: Between sulphate depletion and methane enrichment, a ~250 m wide gap exists. Consequently, no SMTZ can be found under present conditions, but enrichments of pyrite indicate that such zones have existed in the past. Solid layers consisting of authigenic carbonate-cemented sand were partly recovered right above the methane production zone, likely preventing continued upward methane diffusion. At the bottom of the sediment succession, the lower boundary of the methanogenic zone is constrained by sulphate-rich pore waters that appear to originate from a deeper source. Here, a well-established SMTZ exists, but in reversed order (sulphate diffusing up, methane diffusing down). Sulphur isotopes of pyrite reveal that sulphate reduction here does not occur under closed system conditions. This indicates that a deep aquifer is actively recharging the deep sulphate pool. Similar deep SMTZs have been found at other sites, yet mostly in geologically active environments such as ridge flanks or above subduction zones. Therefore Site U1417, in a relatively inactive intraplate environment, represents a so far under-sampled geochemical setting. Calculated accumulation times for authigenic minerals in the deep SMTZ are on the same order of magnitude as the onset of subduction-related bending of the Pacific Plate, suggesting that both processes are linked. Plate bending could create fractures in the overlying sediments allowing seawater to penetrate and recharge a deep aquifer. Our study provides insights into a newly discovered geological process suitable for delivering sulphate-rich water deep into the sediments and installing diagenetically active environments where microbial activity would otherwise be very limited.

Influence of sulphate on the composition and antibacterial and antiviral properties of the exopolysaccharide from Porphyridium cruentum.

PubMed

Raposo, Maria Filomena de Jesus; de Morais, Alcina Maria Miranda Bernardo; de Morais, Rui Manuel Santos Costa

2014-04-17

The influence of two culture media and three different concentrations of sulphate in the medium on the growth of two strains of Porphyridium cruentum and on the production, composition and viscoelastic characteristics, and antimicrobial properties of the sulphated exopolysaccharide (EPS) were studied. A Bohlin C50 rheometer was used to evaluate the viscosity and elasticity of the EPS solutions. HSV virus, types 1 and 2, Vaccinia virus and Vesicular stomatitis virus were used along with two Gram-negative (Escherichia coli and Salmonella enteritidis) and one Gram-positive (Staphylococcus aureus) bacteria, for testing the antimicrobial activity of EPS. The growth of microalgae was higher in NTIP medium and the production of EPS was enhanced by sulphate 21mM. The protein content of the EPS was enhanced by the addition of sulphate 52mM and 104mM; this concentration also induced an increase in sulphate content of the EPS. However, neither the contents of EPS in carbohydrates and uronic acids were affected by the culture medium supplementation in sulphate. In general, the EPS from the Spanish strain presented a higher antiviral activity than the EPS from the Israeli strain. All EPS extracts revealed a strong activity against V. stomatitis virus, higher than the activity of all chemical compounds tested. The EPS from the Israeli strain also presented antibacterial activity against S. enteritidis. Enrichment of the culture medium with sulphate improved protein and sulphate content of EPS. EPS extracts presented a relevant activity against V. stomatitis virus and S. enteritidis bacterium. Copyright © 2014 Elsevier Inc. All rights reserved.

Toxicology studies of primycin-sulphate using a three-dimensional (3D) in vitro human liver aggregate model.

PubMed

Pénzes, Ágota; Mahmud Abdelwahab, Elhusseiny Mohamed; Rapp, Judit; Péteri, Zsanett A; Bovári-Biri, Judit; Fekete, Csaba; Miskei, György; Kvell, Krisztián; Pongrácz, Judit E

2017-11-05

Primycin-sulphate is a highly effective compound against Gram (G) positive bacteria. It has a potentially synergistic effect with vancomycin and statins which makes primycin-sulphate a potentially very effective preparation. Primycin-sulphate is currently used exclusively in topical preparations. In vitro animal hepatocyte and neuromuscular junction studies (in mice, rats, snakes, frogs) as well as in in vitro human red blood cell experiments were used to test toxicity. During these studies, the use of primycin-sulphate resulted in reduced cellular membrane integrity and modified ion channel activity. Additionally, parenteral administration of primycin-sulphate to mice, dogs, cats, rabbits and guinea pigs indicated high level of acute toxicity. The objective of this study was to reveal the cytotoxic and gene expression modifying effects of primycin-sulphate in a human system using an in vitro, three dimensional (3D) human hepatic model system. Within the 3D model, primycin-sulphate presented no acute cytotoxicity at concentrations 1μg/ml and below. However, even at low concentrations, primycin-sulphate affected gene expressions by up-regulating inflammatory cytokines (e.g., IL6), chemokines (e.g., CXCL5) and by down-regulating molecules of the lipid metabolism (e.g., peroxisome proliferator receptor (PPAR) alpha, gamma, etc). Down-regulation of PPAR alpha cannot just disrupt lipid production but can also affect cytochrome P450 metabolic enzyme (CYP) 3A4 expression, highlighting the need for extensive drug-drug interaction (DDI) studies before human oral or parenteral preparations can be developed. Copyright © 2017 Elsevier B.V. All rights reserved.

Differential expression and alternative splicing of rice sulphate transporter family members regulate sulphur status during plant growth, development and stress conditions.

PubMed

Kumar, Smita; Asif, Mehar Hasan; Chakrabarty, Debasis; Tripathi, Rudra Deo; Trivedi, Prabodh Kumar

2011-06-01

Sulphur, an essential nutrient required for plant growth and development, is mainly taken up by the plants as inorganic sulphate from the soil and assimilated into the sulphur reductive pathway. The uptake and transport of sulphate in plants is carried out by transporters encoded by the sulphate transporter gene family. Plant sulphate transporters have been classified with respect to their protein sequences, kinetic properties and tissue-specific localization in Arabidopsis. Though sulphate transporter genes from few other plants have also been characterized, no detailed study with respect to the structure and expression of this family from rice has been carried out. Here, we present genome-wide identification, structural and expression analyses of the rice sulphate transporter gene family. Our analysis using microarray data and MPSS database suggests that 14 rice sulphate transporters are differentially expressed during growth and development in various tissues and during biotic and abiotic stresses. Our analysis also suggests differential accumulation of splice variants of OsSultr1;1 and OsSultr4;1 transcripts during these processes. Apart from known spliced variants, we report an unusual alternative splicing of OsSultr1;1 transcript related to sulphur supply in growth medium and during stress response. Taken together, our study suggests that differential expression and alternative splicing of members of the sulphate transporter family plays an important role in regulating cellular sulphur status required for growth and development and during stress conditions. These findings significantly advance our understanding of the posttranscriptional regulatory mechanisms operating to regulate sulphur demand by the plant.

Isobolographic analysis of the interaction between cadmium (II) and sodium sulphate: toxicological consequences.

PubMed

Mera, Roi; Torres, Enrique; Abalde, Julio

2016-02-01

Sulphate is an essential nutrient for autotrophic organisms and has been shown to have important implications in certain processes of tolerance to cadmium toxicity. Sodium sulphate is the main salt of sulphate in the natural environments. The concentration of this salt is increasing in the aquatic environments due to environmental pollution. The aim of this study was to investigate, using an analysis of isobolograms, the type and the degree of the interaction between Cd(II) and sodium sulphate in the freshwater microalga Chlamydomonas moewusii. Two blocks of experiments were performed, one at sub-optimal sodium sulphate concentrations (<14.2 mg/L) and the other at supra-optimal concentrations (>14.2 mg/L). Three fixed ratios (2:1, 1:1, and 1:2) of the individual EC50 for cadmium and sodium sulphate were used within each block. The isobolographic analysis of interaction at sub-optimal concentrations showed a stronger antagonistic effect with values of interaction index (γ) between 1.46 and 3.4. However, the isobologram with sodium sulphate at supra-optimal concentrations revealed a slight but significant synergistic effect between both chemicals with an interaction index between 0.54 and 0.64. This synergic effect resulted in the potentiation of the toxic effects of cadmium, synergy that was related to the increase of the ionic strength and of two species of cadmium, CdSO4 (aq), and Cd(SO4)2(2-) , in the medium. Results of the current study suggest that sodium sulphate is able to perform a dual antagonist/synergist effect on cadmium toxicity. This role was concentration dependent.

THE ROLE OF THE PINEAL GLAND AND OF ENVIRONMENTAL LIGHTING IN THE REGULATION OF THE ENDOCRINE AND REPRODUCTIVE SYSTEMS OF RODENTS.

DTIC Science & Technology

PHOTOPERIODISM, REPRODUCTION(PHYSIOLOGY)), (*ENDOCRINE GLANDS , REPRODUCTION(PHYSIOLOGY)), RODENTS, REPRODUCTIVE SYSTEM, EYE, EXCISION, TESTES, OVARIES, ADRENAL GLANDS , THYROID GLAND , IODINE, THIOUREA, RATS, HAMSTERS

Isomorphism Within the Hexagonal Columnar Mesophase of Molecular and Macromolecular Self- and Co-Assembled Columns Containing Tapered Groups

DTIC Science & Technology

1994-06-30

benzyloxylbenzoic acid , their corresponding polymethacrylates , and of 4’- methyl (benzo- 15-crown-5)-3,4,5-tris[4-(n-dodecan- 1 -yloxy)benzyloxylbenzoate within...l-yloxy)benzyloxy]benzoic acid , of their corresponding polymethacrylates , and of 4’-methyl(benzo- 15-crown-5)-3,4,5-tris[4- (n-dodecan- 1-yloxy...benzyloxylbenzoic acid , of their corresponding polymethacrylates ,18a and of 4’-methyl(benzo-15-crown-5)-3,4,5-tris[4-(n-dodecan-l- yloxy)benzyloxy]benzoate 1 7

Improved electron injection in spin coated Alq3 incorporated ZnO thin film in the device for solution processed OLEDs

NASA Astrophysics Data System (ADS)

Dasi, Gnyaneshwar; Ramarajan, R.; Thangaraju, Kuppusamy

2018-04-01

We deposit tris-(8-hydroxyquinoline)aluminum (Alq3) incorporated zinc oxide (ZnO) thin films by spin coating method under the normal ambient. It showed the higher transmittance (90% at 550 nm) when compared to that (80% at 550 nm) of spin coated pure ZnO film. SEM studies show that the Alq3 incorporation in ZnO film also enhances the formation of small sized particles arranged in the network of wrinkles on the surface. XRD reveals the improved crystalline properties upon Alq3 inclusion. We fabricate the electron-only devices (EODs) with the structure of ITO/spin coated ZnO:Alq3 as ETL/Alq3 interlayer/LiF/Al. The device showed the higher electron current density of 2.75 mA/cm2 at 12V when compared to that (0.82 mA/cm2 at 12V) of the device using pure ZnO ETL. The device results show that it will be useful to fabricate the low-cost solution processed OLEDs for future lighting and display applications.

Carbon Dioxide Utilization by the Five-Membered Ring Products of Cyclometalation Reactions

PubMed Central

Omae, Iwao

2016-01-01

In carbon dioxide utilization by cyclometalated five-membered ring products, the following compounds are used in four types of applications: 1. 2-Phenylpyrazole iridium compounds, pincer phosphine iridium compounds and 2-phenylimidazoline iridium compounds are used as catalysts for both formic acid production from CO2 and H2, and hydrogen production from the formic acid. This formic acid can be a useful agent for H2 production and storage for fuel cell electric vehicles. 2. Other chemicals, e.g., dimethyl carbonate, methane, methanol and CO, are produced with dimethylaminomethylphenyltin compounds, pincer phosphine iridium compounds, pincer phosphine nickel compound and ruthenium carbene compound or 2-phenylpyridine iridium compounds, and phenylbenzothiazole iridium compounds as the catalysts for the reactions with CO2. 3. The five-membered ring intermediates of cyclometalation reactions with the conventional substrates react with carbon dioxide to afford their many types of carboxylic acid derivatives. 4. Carbon dioxide is easily immobilized at room temperature with immobilizing agents such as pincer phosphine nickel compounds, pincer phosphine palladium compounds, pincer N,N-dimethylaminomethyltin compounds and tris(2-pyridylthio)methane zinc compounds. PMID:28503084

New cyclometalated Iridium(III) beta-dicetone complex as phosphorescent dopant in Organic light emitting devices

NASA Astrophysics Data System (ADS)

Ivanov, P.; Petrova, P.; Stanimirov, S.; Tomova, R.

2017-01-01

A new Bis[4-(benzothiazolato-N,C2‧-2-yl)-N,N-dimethylaniline]Iridium(III) acetylacetonate (Me2N-bt) 2Ir(acac) was synthesized and identified by 1H NMR and elemental analysis. The application of the new compound as a dopant in the hole transporting layer (HTL) of Organic light emitting diode (OLED) structure: HTL/EL/ETL, where HTL was N,N’-bis(3-methylphenyl)-N,N’-diphenylbenzidine (TPD), incorporated in Poly(N-vinylcarbazole) (PVK) matrix, EL - electroluminescent layer of Bis(8-hydroxy-2-methylquinoline)-(4-phenylpheno-xy)aluminum (BAlq) and ETL - electron-transporting layer of Tris-(8-hydroxyquinoline) aluminum (Alq3) or Bis[2-(2-benzothiazoly) phenolato]zinc (Zn(btz)2). We established that the electroluminescent spectra of OLEDs at different concentrations of the dopant were basically the sum of the greenish-blue emission of BAlq and yellowish-green emission of Ir complex. It was found that with increasing of the dopant concentration the relative electroluminescent intensity of Iridium complex emission increased and this of BAlq decreased and as a result the fine tuning of OLED color was observed.

Crystallographic snapshots of active site metal shift in E. coli fructose 1,6-bisphosphate aldolase.

PubMed

Tran, Huyen-Thi; Lee, Seon-Hwa; Ho, Thien-Hoang; Hong, Seung-Hye; Huynh, Kim-Hung; Ahn, Yeh-Jin; Oh, Deok-Kun; Kang, Lin-Woo

2016-12-01

Fructose 1,6-bisphosphate aldolase (FBA) is important for both glycolysis and gluconeogenesis in life. Class II (zinc dependent) FBA is an attractive target for the development of antibiotics against protozoa, bacteria, and fungi, and is also widely used to produce various high-value stereoisomers in the chemical and pharmaceutical industry. In this study, the crystal structures of class II Escherichia coli FBA (EcFBA) were determined from four different crystals, with resolutions between 1.8 Å and 2.0 Å. Native EcFBA structures showed two separate sites of Zn1 (interior position) and Zn2 (active site surface position) for Zn2＋ ion. Citrate and TRIS bound EcFBA structures showed Zn2＋ position exclusively at Zn2. Crystallographic snapshots of EcFBA structures with and without ligand binding proposed the rationale of metal shift at the active site, which might be a hidden mechanism to keep the trace metal cofactor Zn2＋ within EcFBA without losing it. [BMB Reports 2016; 49(12): 681-686].

Carbon Dioxide Utilization by the Five-Membered Ring Products of Cyclometalation Reactions.

PubMed

Omae, Iwao

2016-04-01

In carbon dioxide utilization by cyclometalated five-membered ring products, the following compounds are used in four types of applications: 1. 2-Phenylpyrazole iridium compounds, pincer phosphine iridium compounds and 2-phenylimidazoline iridium compounds are used as catalysts for both formic acid production from CO 2 and H 2 , and hydrogen production from the formic acid. This formic acid can be a useful agent for H 2 production and storage for fuel cell electric vehicles. 2. Other chemicals, e.g. , dimethyl carbonate, methane, methanol and CO, are produced with dimethylaminomethylphenyltin compounds, pincer phosphine iridium compounds, pincer phosphine nickel compound and ruthenium carbene compound or 2-phenylpyridine iridium compounds, and phenylbenzothiazole iridium compounds as the catalysts for the reactions with CO 2 . 3. The five-membered ring intermediates of cyclometalation reactions with the conventional substrates react with carbon dioxide to afford their many types of carboxylic acid derivatives. 4. Carbon dioxide is easily immobilized at room temperature with immobilizing agents such as pincer phosphine nickel compounds, pincer phosphine palladium compounds, pincer N , N -dimethylaminomethyltin compounds and tris(2-pyridylthio)methane zinc compounds.

Possible steric control of the relative strength of chelation enhanced fluorescence for zinc(II) compared to cadmium(II): metal ion complexing properties of tris(2-quinolylmethyl)amine, a crystallographic, UV-visible, and fluorometric study.

PubMed

Williams, Neil J; Gan, Wei; Reibenspies, Joseph H; Hancock, Robert D

2009-02-16

The idea is examined that steric crowding in ligands can lead to diminution of the chelation enhanced fluorescence (CHEF) effect in complexes of the small Zn(II) ion as compared to the larger Cd(II) ion. Steric crowding is less severe for the larger ion and for the smaller Zn(II) ion leads to Zn-N bond length distortion, which allows some quenching of fluorescence by the photoinduced electron transfer (PET) mechanism. Some metal ion complexing properties of the ligand tris(2-quinolylmethyl)amine (TQA) are presented in support of the idea that more sterically efficient ligands, which lead to less M-N bond length distortion with the small Zn(II) ion, will lead to a greater CHEF effect with Zn(II) than Cd(II). The structures of [Zn(TQA)H(2)O](ClO(4))(2).1.5 H(2)O (1), ([Pb(TQA)(NO(3))(2)].C(2)H(5)OH) (2), ([Ag(TQA)(ClO(4))]) (3), and (TQA).C(2)H(5)OH (4) are reported. In 1, the Zn(II) is 5-coordinate, with four N-donors from the ligand and a water molecule making up the coordination sphere. The Zn-N bonds are all of normal length, showing that the level of steric crowding in 1 is not sufficient to cause significant Zn-N bond length distortion. This leads to the observation that, as expected, the CHEF effect in the Zn(II)/TQA complex is much stronger than that in the Cd(II)/TQA complex, in contrast to similar but more sterically crowded ligands, where the CHEF effect is stronger in the Cd(II) complex. The CHEF effect for TQA with the metal ions examined varies as Zn(II) > Cd(II) > Ni(II) > Pb(II) > Hg(II) > Cu(II). The structure of 2 shows an 8-coordinate Pb(II), with evidence of a stereochemically active lone pair, and normal Pb-N bond lengths. In 3, the Ag(I) is 5-coordinate, with four N-donors from the TQA and an oxygen from the perchlorate. The Ag(I) shows no distortion toward linear 2-coordinate geometry, and the Ag-N bonds fall slightly into the upper range for Ag-N bonds in 5-coordinate complexes. The structure of 4 shows the TQA ligand to be involved in pi-stacking between quinolyl groups from adjacent TQA molecules. Formation constants determined by UV-visible spectroscopy are reported in 0.1 M NaClO(4) at 25 degrees C for TQA with Zn(II), Cd(II), and Pb(II). When compared with other similar ligands, one sees that, as the level of steric crowding increases, the stability decreases most with the small Zn(II) ion and least with the large Pb(II) ion. This is in accordance with the idea that TQA has a moderate level of steric crowding and that steric crowding increases for TQA analogs tris(2-pyridylmethyl)amine (TPyA) < TQA < tris(6-methyl-2-pyridyl)amine (TMPyA).

Sperm fertility and viability following 48h of refrigeration: evaluation of different extenders for the preservation of bull semen in liquid state.

PubMed

Crespilho, A M; Nichi, M; Guasti, P N; Freitas-Dell'Aqua, C P; Sá Filho, M F; Maziero, R R; Dell'aqua, J A; Papa, F O

2014-05-01

Two experiments were conducted to compare the effectiveness of different extenders conventionally used for semen cryopreservation to maintain the viability and fertility of cooled bull semen. In Experiment 1, sperm samples obtained from 20 Nellore bulls were preserved at 5°C for 48h using two extenders containing 20% of egg yolk [Tris (TRIS-R) and Botu-Bov(®) (BB)] and another composed of 1% soy lecithin [Botu-Bov(®)-Lecithin (BB-L)] as substitutes for animal origin products. The samples were evaluated at 6, 24 and 48h for plasma and acrosomal membrane integrity, quantification of thiobarbituric acid reactive substances (ng of TBARS/10(8) cells) and sperm motility parameters by computer-assisted semen analysis (CASA). In Experiment 2, pregnancy rate (P/AI) of 973 fixed-time artificially inseminated Nellore cows were compared when cows were inseminated with conventionally cryopreserved semen in TRIS-egg yolk glycerol (TRIS-C Control, n=253) or semen cooled for 48h in TRIS-R (n=233), BB (n=247) or BB-L (n=240). Although none of the extenders used was effective on maintaining total progressive motility and cellular integrity throughout the 48-h of the refrigeration period (P<0.01), BB-L conferred greater protection against oxidative stress (P<0.05) than egg yolk-based medias. The P/AI for semen samples preserved in TRIS-C, TRIS-R, BB and BB-L were 39.92(a), 25.32(b), 26.32(b) and 33.33(ab), respectively. These results demonstrate that the three conventional extenders used for semen cryopreservation do not provide the protection required to maintain bull semen fertility under refrigeration for a 48-h period, resulting in reduced pregnancy rates. However, the use of lecithin-based medium instead of egg yolk results in greater protection against lipid peroxidation, producing P/AI results comparable to those obtained using frozen semen. Copyright © 2014 Elsevier B.V. All rights reserved.

Magnesium sulphate for preventing preterm birth in threatened preterm labour.

PubMed

Crowther, Caroline A; Brown, Julie; McKinlay, Christopher J D; Middleton, Philippa

2014-08-15

Magnesium sulphate has been used in some settings as a tocolytic agent to inhibit uterine activity in women in preterm labour with the aim of preventing preterm birth. To assess the effects of magnesium sulphate therapy given to women in threatened preterm labour with the aim of preventing preterm birth and its sequelae. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (last searched 31 January 2014). Randomised controlled trials of magnesium sulphate as the only tocolytic, administered by any route, compared with either placebo, no treatment or alternative tocolytic therapy (not magnesium sulphate) to women considered to be in preterm labour. At least two review authors assessed trial eligibility and risk of bias and undertook data extraction independently. The 37 included trials (total of 3571 women and over 3600 babies) were generally of moderate to high risk of bias. Antenatal magnesium sulphate was compared with either placebo, no treatment, or a range of alternative tocolytic agents.For the primary outcome of giving birth within 48 hours after trial entry, no significant differences were seen between women who received magnesium sulphate and women who did not (whether placebo/no alternative tocolytic drug, betamimetics, calcium channel blockers, cox inhibitors, prostaglandin inhibitors, or human chorionic gonadotropin) (19 trials, 1913 women). Similarly for the primary outcome of serious infant outcome, there were no significant differences between the infants exposed to magnesium sulphate and those not (whether placebo/no alternative tocolytic drug, betamimetics, calcium channel blockers, cox inhibitors, prostaglandin inhibitors, human chorionic gonadotropin or various tocolytic drugs) (18 trials; 2187 babies). No trials reported the outcome of extremely preterm birth. In the seven trials that reported serious maternal outcomes, no events were recorded.In the group treated with magnesium sulphate compared with women receiving antenatal placebo or no alternative tocolytic drug, a borderline increased risk of total death (fetal, neonatal, infant) was seen (risk ratio (RR) 4.56, 95% confidence interval (CI) 1.00 to 20.86; two trials, 257 babies); none of the comparisons between magnesium sulphate and other classes of tocolytic drugs showed differences for this outcome (10 trials, 991 babies). The outcomes of neonatal and/or infant deaths and of fetal deaths did not show differences between magnesium sulphate and no magnesium sulphate, whether compared with placebo/no alternative tocolytic drug, or any specific class of tocolytic drug. For most of the other secondary outcomes, there were no significant differences between magnesium sulphate and the control groups for risk of preterm birth (except for a significantly lower risk with magnesium sulphate when compared with barbiturates in one trial of 65 women), gestational age at birth, interval between trial entry and birth, other neonatal morbidities, or neurodevelopmental outcomes. Duration of neonatal intensive care unit stay was significantly increased in the magnesium sulphate group compared with the calcium channel blocker group, but not when compared with cox inhibitors or prostaglandin inhibitors. No maternal deaths were reported in the four trials reporting this outcome. Significant differences between magnesium sulphate and controls were not seen for maternal adverse events severe enough to stop treatment, except for a significant benefit of magnesium sulphate compared with betamimetics in a single trial. Magnesium sulphate is ineffective at delaying birth or preventing preterm birth, has no apparent advantages for a range of neonatal and maternal outcomes as a tocolytic agent and its use for this indication may be associated with an increased risk of total fetal, neonatal or infant mortality (in contrast to its use in appropriate groups of women for maternal, fetal, neonatal and infant neuroprotection where beneficial effects have been demonstrated).

Is blinking of the eyes affected in extrapyramidal disorders? An interesting observation in a patient with Wilson disease.

PubMed

Verma, Rajesh; Lalla, Rakesh; Patil, Tushar B

2012-11-27

Blinking of eye is a routine human activity which seldom attracts any attention of clinicians in health and disease. There is experimental evidence that blink rate is affected in extrapyramidal disorders affecting the balance of these neurotransmitters. However, no observations regarding blink rate in Wilson disease (WD) have been reported previously. We report a patient of WD with an increased spontaneous blink rate. A 24-year-old lady presented complaining of tremulousness of both upper limbs and head for 2 years, dysphagia and difficulty in speaking for 1.5 years and abnormal behaviour for last 1 year. We observed that her blink rate at rest was 32/min. Serum ceruloplasmin level was low (0.08 g/l). The patient was started on therapy with D-penicillamine, zinc sulphate, levodopa-carbidopa and trihexiphenidyl. At 1-month follow-up, patient's tremors were markedly decreased and blink rate at rest was decreased to 12/min.

Physicochemical studies on Uburu Salt Lake Ebonyi State-Nigeria.

PubMed

Akubugwo, I E; Ofoegbu, C J; Ukwuoma, C U

2007-09-15

Physicochemical properties of soil (sediment) and water from Uburu salt lake were evaluated and compared with control soil and surface water from the same community. Results showed significant (p < 0.05) higher values for the heavy metals cadmium, chromium, copper, lead and zinc in the lake water relative to the control. The values of these metals in the lake soil (sediments) however, were significantly (p < 0.05) lower than the control soil. Similar significant (p < 0.05) elevations were observed in the lake water temperature, salinity, pH, calcium, magnesium, sodium, potassium, nitrate, carbonate, sulphate and phosphate levels compared to the control. Significant (p < 0.05) changes were also noted in the lake soil's pH, exchangeable acidity, nitrogen, organic carbon, calcium and magnesium levels. Also the soil texture was affected relative to the control. In a number of cases, the values of the studied parameters were higher than the permissible WHO standards. In view of these findings, cautious use of the salt lake soil and water is advocated.

Comparison of Cu2+ and Zn2+ thermalcatalyst in treating diazo dye

NASA Astrophysics Data System (ADS)

Lau, Y. Y.; Wong, Y. S.; Ong, S. A.; Lutpi, N. A.; Ho, L. N.

2018-05-01

This research demonstrates the comparison between copper (II) sulphate (CuSO4) and zinc oxide (ZnO) as thermalcatalysts in thermolysis process for the treatment of diazo reactive black 5 (RB 5) wastewater. CuSO4 was found to be the most effective thermalcatalyst in comparison to ZnO. The color removal efficiency of RB 5 catalysed by CuSO4 and ZnO were 91.55 % at pH 9.5 and 7.36 % at pH 2, respectively. From the UV-Vis wavelength scan, CuSO4 catalyst is able to cleave the molecular structure bonding more efficiently compared to ZnO. ZnO which only show a slight decay on the main chemical network strands: azo bond, naphthalene and benzene rings whereas CuSO4 catalyst is able to fragment azo bond and naphthalene more effectively. The degradation reactions of CuSO4 and ZnO as thermalcatalysts in thermolysis process were compared.

Transmission of helminth eggs through hands in a high-risk community.

PubMed

Gulliver, Francesca; Jeandron, Aurelie; Nguyen, Viet Anh; Do, Hong Anh; Ensink, Jeroen H J

2014-10-01

The role that hands play in the transmission of Ascaris is not well understood. A newly developed method to quantify the presence helminth eggs on hands was tested among a group of farmers in Vietnam. High turbidity in hand rinse samples meant that the adopted sugar solution had to be replaced by zinc sulphate as a flotation solution. The survey found 34% (31/90) of study participant hands' were positive for helminth eggs, though concentrations were low and ranged from 0-10 eggs/2 hands. The use of fresh excreta in agriculture was the only variable that showed an association with the concentrations of eggs found on hands. The results highlight the need to promote handwashing with soap to prevent the transmission of soil-transmitted helminth infections. © The Author 2014. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Sulphation of Rhizobium sp. NGR234 Nod factors is dependent on noeE, a new host-specificity gene.

PubMed

Hanin, M; Jabbouri, S; Quesada-Vincens, D; Freiberg, C; Perret, X; Promé, J C; Broughton, W J; Fellay, R

1997-06-01

Rhizobia secrete specific lipo-chitooligosaccharide signals (LCOs) called Nod factors that are required for infection and nodulation of legumes. In Rhizobium sp. NGR234, the reducing N-acetyl-D-glucosamine of LCOs is substituted at C6 with 2-O-methyl-L-fucose which can be acetylated or sulphated. We identified a flavonoid-inducible locus on the symbiotic plasmid pNGR234a that contains a new nodulation gene, noeE, which is required for the sulphation of NGR234 Nod factors (NodNGR). noeE was identified by conjugation into the closely related Rhizobium fredii strain USDA257, which produces fucosylated but non-sulphated Nod factors (NodUSDA). R. fredii transconjugants producing sulphated LCOs acquire the capacity to nodulate Calopogonium caeruleum. Furthermore, mutation of noeE (NGRdelta noeE) abolishes the production of sulphated LCOs and prevents nodulation of Pachyrhizus tuberosus. The sulphotransferase activity linked to NoeE is specific for fucose. In contrast, the sulphotransferase NodH of Rhizobium meliloti seems to be less specific than NoeE, because its introduction into NGRdelta noeE leads to the production of a mixture of LCOs that are sulphated on C6 of the reducing terminus and sulphated on the 2-O-methylfucose residue. Together, these findings show that noeE is a host-specificity gene which probably encodes a fucose-specific sulphotransferase.

Sulphur and oxygen isotopic characters of dissolved sulphate in groundwater from the Pleistocene aquifer in the southern Jordan Valley (Jericho area, Palestine).

PubMed

Khayat, Saed; Hötzl, Heinz; Geyer, Stefan; Ali, Wasim; Knöller, Kay; Strauch, Gerhard

2006-09-01

Sulphate and chloride concentrations in the shallow Pleistocene aquifer systems in the lower Jordan valley area indicate a general trend of increasing salinity eastward and southward. This study was conducted in one of the important sub-basins feeding the Pleo-Pleistocene aquifer in the Jericho area in the southern part of the valley using S and O isotopes of dissolved sulphate. The results show that sulphate has mainly two contributions to the groundwater. One is the surface seepage, which is present as a salty leachate form with the positive delta34Ssulphate values of primary gypsum in Lisan and Samara formations, and the second is the upwelling saline water which was in contact with a deep secondary gypsum, aragonites and salty rocks and rose up under heavy abstraction with depleted 34S in sulphate and relatively high sulphate and chloride content. The latest was clearly shown in the Arab Project wells to the east that is undergoing a continuous heavy abstraction. The isotopic signatures of S and O in these wells to the east show that this depleted 34S and highly concentrated sulphate might also indicate a dissolved sulphate originating from pyrite oxidation that results from the interaction with a pyrite-rich aquifer, which can well up with salty water under heavy abstraction and is oxidised in the upper aerobic shallow aquifer.

Identification of the sulphate ion as one of the key components of yeast spoilage of a sports drink through genome-wide expression analysis.

PubMed

Jayakody, Lahiru N; Tsuge, Keisuke; Suzuki, Akihiro; Shimoi, Hitoshi; Kitagaki, Hiroshi

2013-01-01

Because of the growing market for sports drinks, prevention of yeast contamination of these beverages is of significant concern. This research was performed to achieve insight into the physiology of yeast growing in sports drinks through a genome-wide approach to prevent microbial spoilage of sports drinks. The genome-wide gene expression profile of Saccharomyces cerevisiae growing in the representative sports drink was investigated. Genes that were relevant to sulphate ion starvation response were upregulated in the yeast cells growing in the drink. These results suggest that yeast cells are suffering from deficiency of extracellular sulphate ions during growth in the sports drink. Indeed, the concentration of sulphate ions was far lower in the sports drink than in a medium that allows the optimal growth of yeast. To prove the starvation of sulphate ions of yeast, several ions were added to the beverage and its effects were investigated. The addition of sulphate ions, but not chloride ions or sodium ions, to the beverage stimulated yeast growth in the beverage in a dose-dependent manner. Moreover, the addition of sulphate ions to the sports drink increased the biosynthesis of sulphur-containing amino acids in yeast cells and hydrogen sulphide in the beverage. These results indicate that sulphate ion concentration should be regulated to prevent microbial spoilage of sports drinks.

Gallium(iii) and iron(iii) complexes of quinolone antimicrobials.

PubMed

Mjos, Katja Dralle; Cawthray, Jacqueline F; Polishchuk, Elena; Abrams, Michael J; Orvig, Chris

2016-08-16

Iron is an essential nutrient for many microbes. According to the "Trojan Horse Hypothesis", biological systems have difficulties distinguishing between Fe(3+) and Ga(3+), which constitutes the antimicrobial efficacy of the gallium(iii) ion. Nine novel tris(quinolono)gallium(iii) complexes and their corresponding iron(iii) analogs have been synthesized and fully characterized. Quinolone antimicrobial agents from three drug generations were used in this study: ciprofloxacin, enoxacin, fleroxacin, levofloxacin, lomefloxacin, nalidixic acid, norfloxacin, oxolinic acid, and pipemidic acid. The antimicrobial efficacy of the tris(quinolono)gallium(iii) complexes was studied against E. faecalis and S. aureus (both Gram-positive), as well as E. coli, K. pneumonia, and P. aeruginosa (all Gram-negative) in direct comparison to the tris(quinolono)iron(iii) complexes and the corresponding free quinolone ligands at various concentrations. For the tris(quinolono)gallium(iii) complexes, no combinational antimicrobial effects between Ga(3+) and the quinolone antimicrobial agents were observed.

Determination of silver, antimony, bismuth, copper, cadmium and indium in ores, concentrates and related materials by atomic-absorption spectrophotometry after methyl isobutyl ketone extraction as iodides.

PubMed

Donaldson, E M; Wang, M

1986-03-01

Methods for determining ~ 0.2 mug g or more of silver and cadmium, ~ 0.5 mug g or more of copper and ~ 5 mug g or more of antimony, bismuth and indium in ores, concentrates and related materials are described. After sample decomposition and recovery of antimony and bismuth retained by lead and calcium sulphates, by co-precipitation with hydrous ferric oxide at pH 6.20 +/- 0.05, iron(III) is reduced to iron(II) with ascorbic acid, and antimony, bismuth, copper, cadmium and indium are separated from the remaining matrix elements by a single methyl isobutyl ketone extraction of their iodides from ~2M sulphuric acid-0.1M potassium iodide. The extract is washed with a sulphuric acid-potassium iodide solution of the same composition to remove residual iron and co-extracted zinc, and the extracted elements are stripped from the extract with 20% v v nitric acid-20% v v hydrogen peroxide. Alternatively, after the removal of lead sulphate by filtration, silver, copper, cadmium and indium can be extracted under the same conditions and stripped with 40% v v nitric acid-25% v v hydrochloric acid. The strip solutions are treated with sulphuric and perchloric acids and ultimately evaporated to dry ness. The individual elements are determined in a 24% v v hydrochloric acid medium containing 1000 mug of potassium per ml by atomic-absorption spectrophotometry with an air-acetylene flame. Tin, arsenic and molybdenum are not co-extracted under the conditions above. Results obtained for silver, antimony, bismuth and indium in some Canadian certified reference materials by these methods are compared with those obtained earlier by previously published methods.

Enhanced liquid-liquid anion exchange using macrocyclic anion receptors: effect of receptor structure on sulphate-nitrate exchange selectivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moyer, Bruce A; Sloop Jr, Frederick; Fowler, Christopher J

2010-01-01

When certain macrocyclic anion receptors are added to a chloroform solution of the nitrate form of a lipophilic quaternary ammonium salt (methyltri-C8,10-ammonium nitrate, Aliquat 336N), the extraction of sulphate from an aqueous sodium nitrate solution via exchange with the organic-phase nitrate is significantly enhanced. Eight macrocycles were surveyed, including two derivatives of a tetraamide macrocycle, five derivatives of calix[4]pyrrole and -decafluorocalix[5]pyrrole. Under the hypothesis that the enhancement originates from sulphate binding by the anion receptors in the chloroform phase, it was possible to obtain reasonable fits to the sulphate distribution survey data based on the formation of 1:1 and 2:1more » receptor:sulphate complexes in the chloroform phase. Apparent 1:1 sulphate-binding constants obtained from the model in this system fell in the range . Comparison of the results for the various anion receptors included in this study reveals that sulphate binding is sensitive to the nature of the substituents on the parent macrocycle scaffolds in a way that does not follow straightforwardly from simple chemical expectations, such as electron-withdrawing effects on hydrogen-bond donor strength.« less

Enhancement of indirect sulphation of limestone by steam addition.

PubMed

Stewart, Michael C; Manovic, Vasilije; Anthony, Edward J; Macchi, Arturo

2010-11-15

The effect of water (H₂O(g)) on in situ SO₂ capture using limestone injection under (FBC) conditions was studied using a thermobalance and tube furnace. The indirect sulphation reaction was found to be greatly enhanced in the presence of H₂O(g). Stoichiometric conversion of samples occurred when sulphated with a synthetic flue gas containing 15% H₂O(g) in under 10 h, which is equivalent to a 45% increase in conversion as compared to sulphation without H₂O(g). Using gas pycnometry and nitrogen adsorption methods, it was shown that limestone samples sulphated in the presence of H₂O(g) undergo increased particle densification without any significant changes to pore area or volume. The microstructural changes and observed increase in conversion were attributed to enhanced solid-state diffusion in CaO/CaSO₄ in the presence of H₂O(g). Given steam has been shown to have such a strong influence on sulphation, whereas it had been previously regarded as inert, may prompt a revisiting of the classically accepted sulphation models and phenomena. These findings also suggest that steam injection may be used to enhance sulfur capture performance in fluidized beds firing low-moisture fuels such as petroleum coke.

Sulphate production by Paracoccus pantotrophus ATCC 35512 from different sulphur substrates: sodium thiosulphate, sulphite and sulphide.

PubMed

Meyer, Daniel Derrossi; Andrino, Felipe Gabriel; Possedente de Lira, Simone; Fornaro, Adalgiza; Corção, Gertrudes; Brandelli, Adriano

2016-01-01

One of the problems in waste water treatment plants (WWTPs) is the increase in emissions of hydrogen sulphide (H2S), which can cause damage to the health of human populations and ecosystems. To control emissions of this gas, sulphur-oxidizing bacteria can be used to convert H2S to sulphate. In this work, sulphate detection was performed by spectrophotometry, ion chromatography and atomic absorption spectrometry, using Paracoccus pantotrophus ATCC 35512 as a reference strain growing in an inorganic broth supplemented with sodium thiosulphate (Na2S2O3·5H2O), sodium sulphide (Na2S) or sodium sulphite (Na2SO3), separately. The strain was metabolically competent in sulphate production. However, it was only possible to observe significant differences in sulphate production compared to abiotic control when the inorganic medium was supplemented with sodium thiosulphate. The three methods for sulphate detection showed similar patterns, although the chromatographic method was the most sensitive for this study. This strain can be used as a reference for sulphate production in studies with sulphur-oxidizing bacteria originating from environmental samples of WWTPs.

Can activated sludge treatments and advanced oxidation processes remove organophosphorus flame retardants?

PubMed

Cristale, Joyce; Ramos, Dayana D; Dantas, Renato F; Machulek Junior, Amilcar; Lacorte, Silvia; Sans, Carme; Esplugas, Santiago

2016-01-01

This study aims to determine the occurrence of 10 OPFRs (including chlorinated, nonchlorinated alkyl and aryl compounds) in influent, effluent wastewaters and partitioning into sludge of 5 wastewater treatment plants (WWTP) in Catalonia (Spain). All target OPFRs were detected in the WWTPs influents, and the total concentration ranged from 3.67 µg L(-1) to 150 µg L(-1). During activated sludge treatment, most OPFRs were accumulated in the sludge at concentrations from 35.3 to 9980 ng g(-1) dw. Chlorinated compounds tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP) and tris(2,3-dichloropropyl) phosphate (TDCPP) were not removed by the conventional activated sludge treatment and they were released by the effluents at approximately the same inlet concentration. On the contrary, aryl compounds tris(methylphenyl) phosphate (TMPP) and 2-ethylhexyl diphenyl phosphate (EHDP) together with alkyl tris(2-ethylhexyl) phosphate (TEHP) were not detected in any of the effluents. Advanced oxidation processes (UV/H2O2 and O3) were applied to investigate the degradability of recalcitrant OPFRs in WWTP effluents. Those detected in the effluent sample (TCEP, TCIPP, TDCPP, tributyl phosphate (TNBP), tri-iso-butyl phosphate (TIBP) and tris(2-butoxyethyl) phosphate (TBOEP)) had very low direct UV-C photolysis rates. TBOEP, TNBP and TIBP were degraded by UV/H2O2 and O3. Chlorinated compounds TCEP, TDCPP and TCIPP were the most recalcitrant OPFR to the advanced oxidation processes applied. The study provides information on the partitioning and degradability pathways of OPFR within conventional activated sludge WWTPs. Copyright © 2015 Elsevier Inc. All rights reserved.

Molecular Imaging of Tumors Using a Quantitative T1 Mapping Technique via Magnetic Resonance Imaging

PubMed Central

Herrmann, Kelsey; Johansen, Mette L.; Craig, Sonya E.; Vincent, Jason; Howell, Michael; Gao, Ying; Lu, Lan; Erokwu, Bernadette; Agnes, Richard S.; Lu, Zheng-Rong; Pokorski, Jonathan K.; Basilion, James; Gulani, Vikas; Griswold, Mark; Flask, Chris; Brady-Kalnay, Susann M.

2015-01-01

Magnetic resonance imaging (MRI) of glioblastoma multiforme (GBM) with molecular imaging agents would allow for the specific localization of brain tumors. Prior studies using T1-weighted MR imaging demonstrated that the SBK2-Tris-(Gd-DOTA)3 molecular imaging agent labeled heterotopic xenograft models of brain tumors more intensely than non-specific contrast agents using conventional T1-weighted imaging techniques. In this study, we used a dynamic quantitative T1 mapping strategy to more objectively compare intra-tumoral retention of the SBK2-Tris-(Gd-DOTA)3 agent over time in comparison to non-targeted control agents. Our results demonstrate that the targeted SBK2-Tris-(Gd-DOTA)3 agent, a scrambled-Tris-(Gd-DOTA)3 control agent, and the non-specific clinical contrast agent Optimark™ all enhanced flank tumors of human glioma cells with similar maximal changes on T1 mapping. However, the retention of the agents differs. The non-specific agents show significant recovery within 20 min by an increase in T1 while the specific agent SBK2-Tris-(Gd-DOTA)3 is retained in the tumors and shows little recovery over 60 min. The retention effect is demonstrated by percent change in T1 values and slope calculations as well as by calculations of gadolinium concentration in tumor compared to muscle. Quantitative T1 mapping demonstrates the superior binding and retention in tumors of the SBK2-Tris-(Gd-DOTA)3 agent over time compared to the non-specific contrast agent currently in clinical use. PMID:26435847

Evidence from simultaneous intracellular- and surface-pH transients that carbonic anhydrase II enhances CO2 fluxes across Xenopus oocyte plasma membranes

PubMed Central

Occhipinti, Rossana; Boron, Walter F.

2014-01-01

The α-carbonic anhydrases (CAs) are zinc-containing enzymes that catalyze the interconversion of CO2 and HCO3−. Here, we focus on human CA II (CA II), a ubiquitous cytoplasmic enzyme. In the second paper in this series, we examine CA IV at the extracellular surface. After microinjecting recombinant CA II in a Tris solution (or just Tris) into oocytes, we expose oocytes to 1.5% CO2/10 mM HCO3−/pH 7.50 while using microelectrodes to monitor intracellular pH (pHi) and surface pH (pHS). CO2 influx causes the familiar sustained pHi fall as well as a transient pHS rise; CO2 efflux does the opposite. Both during CO2 addition and removal, CA II increases the magnitudes of the maximal rate of pHi change, (dpHi/dt)max, and the maximal change in pHS, ΔpHS. Preincubating oocytes with the inhibitor ethoxzolamide eliminates the effects of CA II. Compared with pHS, pHi begins to change only after a delay of ∼9 s and its relaxation has a larger (i.e., slower) time constant (τpHi > τpHS). Simultaneous measurements with two pHi electrodes, one superficial and one deep, suggest that impalement depth contributes to pHi delay and higher τpHi. Using higher CO2/HCO3− levels, i.e., 5%/33 mM HCO3− or 10%/66 mM HCO3−, increases (dpHi/dt)max and ΔpHS, though not in proportion to the increase in [CO2]. A reaction-diffusion mathematical model (described in the third paper in this series) accounts for the above general features and supports the conclusion that cytosolic CA—consuming entering CO2 or replenishing exiting CO2—increases CO2 fluxes across the cell membrane. PMID:24965587

Thiourea derivatives, methods of their preparation and their use in neutron capture therapy of malignant melanoma

DOEpatents

Gabel, D.

1991-06-04

The present invention pertains to boron containing thiouracil derivatives, their method of preparations, and their use in the therapy of malignant melanoma using boron neutron capture therapy. No Drawings

40 CFR Appendix I to Part 192 - Listed Constituents

Code of Federal Regulations, 2010 CFR

2010-07-01

...-Naphthylthiourea (Thiourea, 1-naphthalenyl-) Nickel and compounds, N.O.S. Nickel carbonyl (Ni(CO)4 (T-4)-) Nickel cyanide (Ni(CN)2) Nicotine and salts (Pyridine, 3-(1-methyl-2-pyrrolidinyl)-, (S)-) Nitric oxide (Nitrogen...

40 CFR Appendix I to Part 192 - Listed Constituents

Code of Federal Regulations, 2011 CFR

2011-07-01

...-Naphthylthiourea (Thiourea, 1-naphthalenyl-) Nickel and compounds, N.O.S. Nickel carbonyl (Ni(CO)4 (T-4)-) Nickel cyanide (Ni(CN)2) Nicotine and salts (Pyridine, 3-(1-methyl-2-pyrrolidinyl)-, (S)-) Nitric oxide (Nitrogen...

Research notes : information at your fingertips!

DOT National Transportation Integrated Search

2000-03-01

TRIS Online includes full-text reports or links to publishers or suppliers of the original documents. You will find titles, publication dates, authors, abstracts, and document sources. : Each year over 20,000 new records are added to TRIS. The databa...

The preparation and degradation performance of CdS photocatalysts to methyl orange solution.

PubMed

Duan, Limei; Zhao, Weiqiang; Xu, Ling; Chen, Xiaohong; Lita, A; Liu, Zongrui

2013-03-01

In this paper, the CdS samples were prepared using thiourea or sodium sulfide as sulfur source by hydrothermal or solvothermal synthesis method, the results of XRD, TEM and SEM showed all the samples belong to hexagonal CdS nano-material with different morphologies. Using the degradation of methyl orange solution as a model reaction, the photocatalytic performance of different CdS samples was measured, and the samples prepared using thiourea as sulfur source exhibited better photocatalytic activity than those using sodium sulfide as sulfur source. The factors on degradation effect were discussed including the pH value of degradation system and the type of light source. The degradation effect of CdS samples increased with the pH value decreased, and the degradation effect was better when the methyl orange solution was irradiated under sunlight than under 250 W mercury lamp.

Synthesis, characterization, antioxidant and brine shrimp cytotoxic activity of novel 3-benzothioyl-1-(3-hydroxy-3-phenyl -3-propyl)-1-methylthiourea.

PubMed

Shoaib, Mohammad; Ullah, Abid; Shah, Syed Wadood Ali; Tahir, Muhammad Nawaz

2017-07-01

In the present research work novel ephedrine based thiourea derivative, 3-benzothioyl-1-(3-hydroxy-3-phenyl -3-propyl)-1-methylthiourea 4is synthesized and then characterized elemental analyzed via various techniques i.e., Proton NMR, carbon13 NMR and fatherly confirmed via X-ray crystallography. Compound 4 was then screened for their possible antioxidant and cytotoxic potentials. Benzoyl chloride was treated with an equimolar potassium thiocyanate in acetone to achieve benzoyl isothiocyantes. It was then treated with an equimolar (1R, 2S)-(-)-Ephedrine to obtain the 3-benzothioyl-1-(3-hydroxy-3-phenyl-3-propyl)-1-methyl thiourea4. It was then screened for antioxidant and cytotoxic potentials. The compound 4 showed excellent antioxidant activity almost comparable to ascorbic acid (standard) and have significant cytotoxic activity with LC 50 value 05±0.58 ppm.

Synthesis and structural characterization of some trisulfide analoges of thiouracil-based antithyroid drugs

NASA Astrophysics Data System (ADS)

Bhabak, Krishna P.; Bhowmick, Debasish

2012-08-01

Thiourea-based antithyroid drugs are effectively used for the treatment of hyperthyroidism. In this paper, we describe the synthesis of new trisulfides (11-12) from the commonly used thiourea-based antithyroid drugs such as 6-n-propyl-2-thiouracil (PTU) and 6-methyl-2-thiouracil (MTU) in the reaction with I2/KI system. Structural analysis by single crystal X-ray diffraction studies revealed the stabilization of trisulfides by a lactam-lactim tautomerism facilitating effective intramolecular as well as intermolecular non-covalent interactions. Although the structures of both trisulfides were found to be quite similar, a notable difference in the intermolecular interactions was observed between compounds 11 and 12 leading to different structural patterns. Structural stabilization of these trisulfides by tautomerism followed by intramolecular as well as intermolecular H-bonds makes these molecules as perfect examples in molecular recognition with self-complementary donor and acceptor units within a single molecule.

Preparation and characterization of Ni-P/Ni3.1B composite alloy coatings

NASA Astrophysics Data System (ADS)

Wang, Yurong; He, Jiawei; Wang, Wenchang; Shi, Jianhua; Mitsuzaki, Naotoshi; Chen, Zhidong

2014-02-01

The preparation of Ni-P/Ni3.1B composite alloy coating on the surface of copper was achieved by co-deposition of Ni3.1B nanoparticles with Ni-P coating during electroless plating. Ni-P-B alloy coating was obtained by heat-treating the as-plated Ni-P/Ni3.1B composite coating. The effect of the concentration of sodium alginate, borax, thiourea, Ni3.1B, temperature, and pH value on the deposition rate and B content were investigated and determined to be: 30 g L-1, 10 g L-1, 2 mg L-1, 20 mg L-1, 70 °C and 9.0 , respectively. Sodium alginate and thiourea were played as surfactant for coating Ni3.1B nanoparticles and stabilizer for the plating bath, respectively. Ni-P/Ni3.1B composite coating had good performance such as corrosion resistance and solderability.

14N NQR study of hydrogen bonded complexes of 1,4 diazabicyclo [2,2,2] octane (ted) with phenols and thiourea

NASA Astrophysics Data System (ADS)

Murgich, Juan; Magaly, Santana R.; Diaz, Olga E.

The 14N NQR spectra of H bonded complexes of 1,4 diazabicyclo [2,2,2] octane, also known as triethylenediamine (TED), with phenol (1:2), p-chlorophenol (1:2), p-nitrophenol (1:2), hydroquinone (1:1), resorcinol (1:1) and thiourea (1:2) were observed at 77 K. The 14N frequency shifts produced by the H bonds in the TED complexes were approximately two times larger than those found for similar complexes of Hexamethylenetetramine (HMT). Such change was explained by the effect on the remaining N atoms of the increase in the number of -CH 2- groups and the decrease in N atoms in passing from HMT to TED. From the above results it seems that the inductive effect plays an important role in the formation of H bonds in tertiary amines like HMT and TED.

A thiourea derivative as potential ionophore for copper sensing

NASA Astrophysics Data System (ADS)

Ying, Kook Shih; Heng, Lee Yook; Hassan, Nurul Izzaty; Hasbullah, Siti Aishah

2018-04-01

A new thiourea derivative, N1,N3-bis[[3,5-bis(trifluoromethyl)phenyl]carbamothioyl]isophthalamide (TPC), as a potential copper ionophore was investigated. TPC was immobilized via drop casting method into poly(n-butyl acrylate) pBA membrane and the sensor was characterized by potentiometric method. The sensor fabricated based on TPC showed a Nernstian response towards copper ion with the slope of 27.07±2.84 mV/decade in the range of 1.0×10-6 - 1.0-10-4 M and limit of detection of 6.24 × 10-7 M. In addition, based on the separate solution method (SSM), the logarithm selectivity coefficients were less than -3.00 for monovalent, divalent and trivalent cations that are present in the environmental water samples such as K+, Ca2+, Mg2+ and Fe3+. This confirmed that the sensor fabricated with TPC exhibited good sensitivity and selectivity towards copper ion.

A new adaptive L1-norm for optimal descriptor selection of high-dimensional QSAR classification model for anti-hepatitis C virus activity of thiourea derivatives.

PubMed

Algamal, Z Y; Lee, M H

2017-01-01

A high-dimensional quantitative structure-activity relationship (QSAR) classification model typically contains a large number of irrelevant and redundant descriptors. In this paper, a new design of descriptor selection for the QSAR classification model estimation method is proposed by adding a new weight inside L1-norm. The experimental results of classifying the anti-hepatitis C virus activity of thiourea derivatives demonstrate that the proposed descriptor selection method in the QSAR classification model performs effectively and competitively compared with other existing penalized methods in terms of classification performance on both the training and the testing datasets. Moreover, it is noteworthy that the results obtained in terms of stability test and applicability domain provide a robust QSAR classification model. It is evident from the results that the developed QSAR classification model could conceivably be employed for further high-dimensional QSAR classification studies.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beletskiy, Evgeny V.; Wang, Xue-Bin; Kass, Steven R.

A benzene ring substituted with 1–3 thiourea containing arms (1–3) were examined by photoelectron spectroscopy and density functional theory computations. Their conjugate bases and chloride, acetate and dihydrogen phosphate anion clusters are reported. The resulting vertical and adiabatic detachment energies span from 3.93 – 5.82 eV (VDE) and 3.65 – 5.10 (ADE) for the deprotonated species and 4.88 – 5.97 eV (VDE) and 4.45 – 5.60 eV (ADE) for the anion complexes. These results reveal the stabilizing effects of multiple hydrogen bonds and anionic host-guest interactions in the gas phase. Previously measured equilibrium binding constants in aqueous dimethyl sulfoxide formore » all three thioureas (Org. Biolmol. Chem. 2015, 13, 2170-2176) are compared to the present results and cooperative binding is uniformly observed in the gas phase but only for one case (i.e., 3 • H2PO4–) in solution.« less

Chondroitin sulphates A, B and C, collagen types I-IV and fibronectin in venous sinus of the red pulp in human spleen.

PubMed

Rovenská, E; Michalka, P; Papincák, J; Durdík, S; Jakubovský, J

2005-01-01

The morphological relationship of chondroitin sulphates A, B, and C, collagen types I-IV and fibronectin in the wall of venous sinuses of the red pulp in human spleen has not been a focus of interest among morphologists. Regarding the hypothesis that the structure of the spleen lends it the function of a blood filter the substances described in our study might play a significant role in the functional morphology. Of 146 human spleen surgical specimens, groups of 12 specimens each were examined under a light microscope using the method of antibodies against fibronectin, against collagen types I-IV and against chondroitin sulphates A, B, and C. The sections of the red pulp of human spleen stained with hematoxylin and eosin provided limited information about the wall of the sinuses. Chondroitin sulphates A and B were observed on the surface of sinus-lining cells (SLC), and fibronectin was detected on the surface of the annular fibers. Collagen type 11 was observed almost in the same places as chondroitin sulphates A and B. Collagen type IV was present in annular fibers of the wall of the sinus and in the basement membrane, like fibronectin. Chondroitin sulphate was not present in the walls of sinuses. Binding of antibodies against chondroitin sulphate A and against chondroitin sulphate B indicates the presence of chondroitin sulfates on the surface of SLC, where they probably play a role in helping the human organism to recognize alien and self substances. The presence of chondroitin,sulphates A and B probably affects inhibition of binding of cells with collagen type I, but not with fibronectin.

Determination of chondroitin-6-sulphate by a competitive enzyme immunoassay using a biotinylated antigen.

PubMed

Kähnert, H; Brinkmann, T; Gässler, N; Kleesiek, K

1994-04-01

A competitive enzyme immunoassay was developed to determine chondroitin-6-sulphate in body fluids and cell cultures. The assay uses a monoclonal anti-chondroitin-6-sulphate antibody, immobilised to microtitre plates, and it involves a competitive binding reaction between chondroitin-6-sulphate in the samples and the biotinylated antigen. This assay enables the quantification of chondroitin-6-sulphate in the low concentration range of 16-120 micrograms/l. The intra-assay and inter-assay coefficients of variation are below 6.5% and 9.0%, respectively. More than 90% of chondroitin-6-sulphate was recovered when added to 0.1 mol/l phosphate-buffered saline, an albumin solution (40 g/l in phosphate-buffered saline) and cell culture medium (containing 100 ml/l foetal calf serum). Chondroitin-6-sulphate was also determined in sera of healthy male (n = 90) and female (n = 90) blood donors. The normal range was 55-169 micrograms/l. In men the mean value was estimated at 102.2 +/- 37.1 micrograms/l and in women at 98.7 +/- 26.4 micrograms/l. No age or sex dependence was observed. The urine excretion of chondroitin-6-sulphate in men (n = 16) was 44.5 +/- 21.1 mg/kg creatinine (mean +/- standard deviation) and in females (n = 10) 53.5 +/- 21.3 mg/kg creatinine. The clearance rate in men was 0.41 +/- 0.22 ml x min-1 and in women 0.38 +/- 0.15 ml x min-1. No sex dependence was found. Furthermore, the enzyme immunoassay was modified to measure the specific incorporation of a radioactively labelled precursor ([14C]galactosamine) into chondroitin-6-sulphate.(ABSTRACT TRUNCATED AT 250 WORDS)

New tools for carbohydrate sulphation analysis: Heparan Sulphate 2- O -sulphotransferase (HS2ST) is a target for small molecule protein kinase inhibitors.

PubMed

Byrne, Dominic P; Li, Yong; Ramakrishnan, Krithika; Barsukov, Igor L; Yates, Edwin A; Eyers, Claire E; Papy-Garcia, Dulcé; Chantepie, Sandrine; Pagadala, Vijayakanth; Lu, Jian; Wells, Carrow; Drewry, David H; Zuercher, William J; Berry, Neil G; Fernig, David G; Eyers, Patrick A

2018-06-22

Sulphation of carbohydrate residues occurs on a variety of glycans destined for secretion, and this modification is essential for efficient matrix-based signal transduction. Heparan sulphate (HS) glycosaminoglycans control physiological functions ranging from blood coagulation to cell proliferation. HS biosynthesis involves membrane-bound Golgi sulphotransferases, including heparan sulphate 2- O -sulphotransferase (HS2ST), which transfers sulphate from the co-factor PAPS (3'-phosphoadenosine 5'-phosphosulphate) to the 2- O  position of a-L-iduronate in the maturing polysaccharide chain. The current lack of simple non-radioactive enzyme assays that can be used to quantify the levels of carbohydrate sulphation hampers kinetic analysis of this process and the discovery of HS2ST inhibitors.  In this paper, we describe a new procedure for thermal shift analysis of purified HS2ST. Using this approach, we quantify HS2ST-catalyzed oligosaccharide sulphation using a novel synthetic fluorescent substrate and screen the Published Kinase Inhibitor Set (PKIS), to evaluate compounds that inhibit catalysis. We report the susceptibility of HS2ST to a variety of cell permeable compounds in vitro , including polyanionic polar molecules, the protein kinase inhibitor rottlerin and oxindole-based RAF kinase inhibitors. In a related study, published back-to-back with this article, we demonstrate that Tyrosyl Protein Sulpho Tranferases (TPSTs) are also inhibited by a variety of protein kinase inhibitors. We propose that appropriately validated small molecule compounds could become new tools for rapid inhibition of glycan (and protein) sulphation in cells, and that protein kinase inhibitors might be repurposed or redesigned for the specific inhibition of HS2ST. ©2018 The Author(s).

Carbon Monoxide as an Electron Donor for the Biological Reduction of Sulphate

PubMed Central

Parshina, Sofiya N.; Sipma, Jan; Henstra, Anne Meint; Stams, Alfons J. M.

2010-01-01

Several strains of Gram-negative and Gram-positive sulphate-reducing bacteria (SRB) are able to use carbon monoxide (CO) as a carbon source and electron donor for biological sulphate reduction. These strains exhibit variable resistance to CO toxicity. The most resistant SRB can grow and use CO as an electron donor at concentrations up to 100%, whereas others are already severely inhibited at CO concentrations as low as 1-2%. Here, the utilization, inhibition characteristics, and enzymology of CO metabolism as well as the current state of genomics of CO-oxidizing SRB are reviewed. Carboxydotrophic sulphate-reducing bacteria can be applied for biological sulphate reduction with synthesis gas (a mixture of hydrogen and carbon monoxide) as an electron donor. PMID:20628586

Ultraviolet reflective coating

NASA Technical Reports Server (NTRS)

Schutt, J. B.

1974-01-01

Composition consists of dispersion of barium sulphate in aqueous solution of water-soluble inorganic binder. Binder is selected from group consisting of alkali metal sulphates. Coating exhibits high reflectance of ultraviolet light to wavelengths of approximately 200.0 nm, which compares favorably with high reflectance of virgin barium sulphate power.

Aluminum and sulphate removal by a highly Al-resistant dissimilatory sulphate-reducing bacteria community.

PubMed

Martins, Mónica; Taborda, Rita; Silva, Gonçalo; Assunção, Ana; Matos, António Pedro; Costa, Maria Clara

2012-09-01

A highly Al-resistant dissimilatory sulphate-reducing bacteria community was isolated from sludge of the wetland of Urgeiriça mine (community W). This community showed excellent sulphate removal at the presence of Al³⁺. After 27 days of incubation, 73, 86 and 81% of sulphate was removed in the presence of 0.48, 0.90 and 1.30 mM of Al³⁺, respectively. Moreover, Al³⁺ was simultaneously removed: 55, 85 and 78% of metal was removed in the presence of 0.48, 0.90 and 1.30 mM of Al³⁺, respectively. The dissociation of aluminium-lactate soluble complexes due to lactate consumption by dissimilatory sulphate-reducing bacteria can be responsible for aluminum removal, which probably precipitates as insoluble aluminium hydroxide. Phylogenetic analysis of 16S rRNA gene showed that this community was mainly composed by bacteria closely related to Desulfovibrio desulfuricans. However, bacteria affiliated to Proteus and Ralstonia were also present in the community.

Prevention of thaumasite formation in concrete exposed to sulphate attack

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bellmann, F.; Stark, J.

2007-08-15

Thermodynamic calculations were performed to investigate at which sulphate ion concentration hardened concrete can be damaged by the formation of thaumasite. It is indicated that thaumasite can be formed from C-S-H phases and portlandite at very low sulphate concentrations in an aggressive solution. Higher sulphate ion concentrations are required in the absence of portlandite. Still higher sulphate ion concentrations are needed if C-S-H phases with a low calcium/silicon ratio are consumed. Therefore, it is suggested that the formation of thaumasite at low and moderate sulphate concentrations in the attacking solution can be avoided by lowering the calcium/silicon ratio in themore » C-S-H phases. This can be achieved by the addition of pozzolanic and latently hydraulic admixtures. During the reaction of these materials, portlandite is consumed and the calcium/silicon ratio of the C-S-H phases is lowered. The aforementioned concept was confirmed by studies published in the literature and also by experimental investigations reported in this paper.« less

Phosphorus-containing imide resins

NASA Technical Reports Server (NTRS)

Varma, I. K.; Fohlen, G. M.; Parker, J. A. (Inventor)

1985-01-01

Cured polymers of bis and tris-imides derived from tris(m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, and addition polymers of such imides, including a variant in which a monoimide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride prior to curing are disclosed and claimed. Such polymers are flame resistant. Also disclosed are an improved method of producing tris(m-aminophenyl) phosphine oxides from the nitro analogues by reduction with hydrazine hydrate using palladized charcoal or Raney nickel as the catalyst and fiber reinforced cured resin composites.

Photoemission study of tris(8-hydroxyquinoline) aluminum/aluminum oxide/tris(8-hydroxyquinoline) aluminum interface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding Huanjun; Zorba, Serkan; Gao Yongli

2006-12-01

The evolution of the interface electronic structure of a sandwich structure involving aluminum oxide and tris(8-hydroxyquinoline) aluminum (Alq), i.e. (Alq/AlO{sub x}/Alq), has been investigated with photoemission spectroscopy. Strong chemical reactions have been observed due to aluminum deposition onto the Alq substrate. The subsequent oxygen exposure releases some of the Alq molecules from the interaction with aluminum. Finally, the deposition of the top Alq layer leads to an asymmetry in the electronic energy level alignment with respect to the AlO{sub x} interlayer.

Phosphorus-containing imide resins

NASA Technical Reports Server (NTRS)

Varma, I. K.; Fohlen, G. M.; Parker, J. A. (Inventor)

1983-01-01

Bis- and tris-imides derived from tris (m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, and addition polymers of such imides, including a variant in which a mono-imide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride. Such monomers or their oligomes may be used to impregnate fibers and fabrics which when cured, are flame resistant. Also an improved method of producing tris (m-aminophenyl) phosphine oxides from the nitro analogues by reduction with hydrazine hydrate using palladized charcoal or Raney nickel as the catalyst is described.

Batch and fixed-bed assessment of sulphate removal by the weak base ion exchange resin Amberlyst A21.

PubMed

Guimarães, Damaris; Leão, Versiane A

2014-09-15

This paper investigated sulphate removal from aqueous solutions by Amberlyst A21, a polystyrene weak base ion exchange resin. Both the pH and initial sulphate concentration were observed to strongly affect sorption yields, which were largest in acidic environments. Working under optimum operational conditions, sulphate sorption by Amberlyst A21 was relatively fast and reached equilibrium after 45 min of contact between the solid and liquid phases. Sorption kinetics could be described by either the pseudo-first order (k1=3.05 × 10(-5)s(-1)) or pseudo-second order model (k2=1.67 × 10(-4)s(-1)), and both the Freundlich and Langmuir models successfully fitted the equilibrium data. Sulphate uptake by Amberlyst A21 was a physisorption process (ΔH=-25.06 kJ mol(-1)) that occurred with entropy reduction (ΔS=-0.042 kJ mol(-1)K(-1)). Elution experiments showed that sulphate is easily desorbed (∼ 100%) from the resin by sodium hydroxide solutions at pH 10 or pH 12. Fixed-bed experiments assessed the effects of the initial sulphate concentration, bed height and flow rate on the breakthrough curves and the efficiency of the Amberlyst A21 in the treatment of a real effluent. In all studied conditions, the maximum sulphate loading resin varied between 8 and 40 mg(SO4(2-))mL(resin)(-1). Copyright © 2014 Elsevier B.V. All rights reserved.

Sultr4;1 mutant seeds of Arabidopsis have an enhanced sulphate content and modified proteome suggesting metabolic adaptations to altered sulphate compartmentalization

PubMed Central

2010-01-01

Background Sulphur is an essential macronutrient needed for the synthesis of many cellular components. Sulphur containing amino acids and stress response-related compounds, such as glutathione, are derived from reduction of root-absorbed sulphate. Sulphate distribution in cell compartments necessitates specific transport systems. The low-affinity sulphate transporters SULTR4;1 and SULTR4;2 have been localized to the vacuolar membrane, where they may facilitate sulphate efflux from the vacuole. Results In the present study, we demonstrated that the Sultr4;1 gene is expressed in developing Arabidopsis seeds to a level over 10-fold higher than the Sultr4;2 gene. A characterization of dry mature seeds from a Sultr4;1 T-DNA mutant revealed a higher sulphate content, implying a function for this transporter in developing seeds. A fine dissection of the Sultr4;1 seed proteome identified 29 spots whose abundance varied compared to wild-type. Specific metabolic features characteristic of an adaptive response were revealed, such as an up-accumulation of various proteins involved in sugar metabolism and in detoxification processes. Conclusions This study revealed a role for SULTR4;1 in determining sulphate content of mature Arabidopsis seeds. Moreover, the adaptive response of sultr4;1 mutant seeds as revealed by proteomics suggests a function of SULTR4;1 in redox homeostasis, a mechanism that has to be tightly controlled during development of orthodox seeds. PMID:20426829

DNA stretching on the wall surfaces in curved microchannels with different radii.

PubMed

Hsieh, Shou-Shing; Wu, Fong-He; Tsai, Ming-Ju

2014-01-01

DNA molecule conformation dynamics and stretching were made on semi-circular surfaces with different radii (500 to 5,000 μm) in microchannels measuring 200 μm × 200 μm in cross section. Five different buffer solutions - 1× Tris-acetate-EDTA (TAE), 1× Tris-borate-EDTA (TBE), 1× Tris-EDTA (TE), 1× Tris-phosphate-EDTA (TPE), and 1× Tris-buffered saline (TBS) solutions - were used with a variety of viscosity such as 40, 60, and 80 cP, with resultant 10(-4) ≤ Re ≤ 10(-3) and the corresponding 5 ≤ Wi ≤ 12. The test fluids were seeded with JOJO-1 tracer particles for flow visualization and driven through the test channels via a piezoelectric (PZT) micropump. Micro particle image velocimetry (μPIV) measuring technique was applied for the centered-plane velocity distribution measurements. It is found that the radius effect on the stretch ratio of DNA dependence is significant. The stretch ratio becomes larger as the radius becomes small due to the larger centrifugal force. Consequently, the maximum stretch was found at the center of the channel with a radius of 500 μm.

DNA stretching on the wall surfaces in curved microchannels with different radii

PubMed Central

2014-01-01

DNA molecule conformation dynamics and stretching were made on semi-circular surfaces with different radii (500 to 5,000 μm) in microchannels measuring 200 μm × 200 μm in cross section. Five different buffer solutions - 1× Tris-acetate-EDTA (TAE), 1× Tris-borate-EDTA (TBE), 1× Tris-EDTA (TE), 1× Tris-phosphate-EDTA (TPE), and 1× Tris-buffered saline (TBS) solutions - were used with a variety of viscosity such as 40, 60, and 80 cP, with resultant 10−4 ≤ Re ≤ 10−3 and the corresponding 5 ≤ Wi ≤ 12. The test fluids were seeded with JOJO-1 tracer particles for flow visualization and driven through the test channels via a piezoelectric (PZT) micropump. Micro particle image velocimetry (μPIV) measuring technique was applied for the centered-plane velocity distribution measurements. It is found that the radius effect on the stretch ratio of DNA dependence is significant. The stretch ratio becomes larger as the radius becomes small due to the larger centrifugal force. Consequently, the maximum stretch was found at the center of the channel with a radius of 500 μm. PMID:25147488

Fluorescent chemosensor based on urea/thiourea moiety for sensing of Hg(II) ions in an aqueous medium with high sensitivity and selectivity: A comparative account on effect of molecular architecture on chemosensing

NASA Astrophysics Data System (ADS)

Mishra, Jayanti; Kaur, Harpreet; Ganguli, Ashok K.; Kaur, Navneet

2018-06-01

Mercury is a well-known heavy metal ion which is extremely poisonous to health but is still employed in the form of mercury salts and organomercury compounds in various industrial, anthropological and agricultural activities. Henceforth, its sensing in aqueous medium is an area of great interest in order to avoid its hazardous effect. In the present manuscript, urea/thiourea linkage bearing four organic ligands (1a, 1b, 2a and 2b) are synthesized by a three-step synthetic approach. The organic ligands were then employed to develop organic nanoparticles by re-precipitation method which was further probed for their selective recognition behavior in an aqueous medium using fluorescence spectroscopy. The fluorescence emission profile of the ONPs is used as a tool for the tracking of sensing behavior. The ONPs of 1b has shown selective recognition towards Hg(II) in aqueous medium evidenced by enhancement of fluorescence emission intensity after complexation of 1b ONP with Hg(II), among several alkali, alkaline earth and transition metal ions with a detection limit of the order of 0.84 μM. The ability of the proposed sensor to sense Hg(II) ions with high selectivity and sensitivity could be accounted to photo-induced electron transfer (PET) "OFF" mechanism at λem = 390 nm. This study reveals the application of the proposed thiourea-based sensor for the selective recognition of the Hg(II) ions in an aqueous medium.

Crystal structures and vibrational spectroscopy of copper(I) thiourea complexes.

PubMed

Bowmaker, Graham A; Hanna, John V; Pakawatchai, Chaveng; Skelton, Brian W; Thanyasirikul, Yupa; White, Allan H

2009-01-05

Several synthetic strategies using copper(I) starting materials or copper(II) compounds and an in situ sulfite reductant have been used to systematically explore the chemistry of copper(I) complexes with thiourea and substituted thiourea ligands. This has resulted in the discovery of several new complexes and methods for the bulk synthesis of some previously reported complexes that had been prepared adventitiously in small quantity. The new complexes are (tu = thiourea, dmtu = N,N'-dimethylthiourea, etu = ethylenethiourea): [I(4)Cu(4)(tu)(6)].H(2)O, [Cu(4)(tu)(10)](NO(3)).tu.3H(2)O, [BrCu(dmtu)(3)], [ICu(dmtu)(3)](2), [BrCu(etu)(2)](2), [ICu(etu)(2)], [ICu(etu)(2)](3). [I(4)Cu(4)(tu)(6)].H(2)O has an adamantanoid structure, with four terminal iodide ligands and six doubly bridging tu ligands. In contrast to this, [Cu(4)(tu)(10)](NO(3)).tu.3H(2)O contains a tetranuclear cluster in which four of the tu ligands are terminal and the other six are doubly bridging. [BrCu(dmtu)(3)] is a mononuclear complex with tetrahedral coordination of copper by one bromide and three dmtu ligands, whereas [Cu(dmtu)(3)](2)I(2) has a centrosymmetric dimeric cation with two uncoordinated iodides, four terminal dmtu and two doubly bridging dmtu ligands, [(dmtu)(2)Cu(mu-S-dmtu)(2)Cu(dmtu)(2)]I(2). A reversal of this monomer to dimer trend from bromide to iodide is seen for the etu counterparts: [BrCu(etu)(2)](2) is a centrosymmetric dimer with two doubly bridging etu ligands, [(etu)BrCu(mu-S-etu)(2)CuBr(etu)], whereas [ICu(etu)(2)] is a trigonal planar monomer, although the novel [I(3)Cu(3)(etu)(6)] is also defined. Infrared and Raman spectra of the synthesized complexes were recorded and the metal-ligand vibrational frequencies have been assigned in many cases. The results confirm previously observed correlations between the vibrational frequencies and the corresponding bond lengths for complexes of the unsubstituted tu ligand. A mechanochemical/infrared method was used to synthesize [I(3)Cu(3)(etu)(6)] from CuI and etu, and to demonstrate the polymorphic transition from [ICu(etu)(2)] to [I(3)Cu(3)(etu)(6)].

Massive Volcanic SO2 Oxidation and Sulphate Aerosol Deposition in Cenozoic North America

EPA Science Inventory

Volcanic eruptions release a large amount of sulphur dioxide (SO₂) into the atmosphere. SO₂ is oxidized to sulphate and can subsequently form sulphate aerosol, which can affect the Earth's radiation balance, biologic productivity and high-altitude ozone co...

Biochemical properties of a keratan sulphate/chondroitin sulphate proteoglycan expressed in primate pluripotent stem cells*

PubMed Central

Cooper, Susan; Bennett, William; Andrade, Jessica; Reubinoff, Benjamin E; Thomson, James; Pera, Martin F

2002-01-01

We previously identified a pericellular matrix keratan sulphate/chondroitin sulphate proteoglycan present on the surface of human embryonal carcinoma stem cells, cells whose differentiation mimics early development. Antibodies reactive with various epitopes on this molecule define a cluster of differentiation markers for primate pluripotent stem cells. We describe the purification of a form of this molecule which is secreted or shed into the culture medium. Biochemical analysis of the secreted form of this molecule shows that the monomeric form, whilst containing keratan sulphate, resembles mucins in its structure and its modification with O-linked carbohydrate. Immunofluorescence and immunoblotting data show that monkey and human pluripotent stem cells react with antibodies directed against epitopes on either carbohydrate side chains or the protein core of the molecule. PMID:12033730

Sulphated glycosaminoglycans and proteoglycans in the developing vertebral column of juvenile Atlantic salmon (Salmo salar).

PubMed

Hannesson, Kirsten O; Ytteborg, Elisabeth; Takle, Harald; Enersen, Grethe; Bæverfjord, Grete; Pedersen, Mona E

2015-08-01

In the present study, the distribution of sulphated glycosaminoglycans (GAGs) in the developing vertebral column of Atlantic salmon (Salmo salar) at 700, 900, 1100 and 1400 d° was examined by light microscopy. The mineralization pattern was outlined by Alizarin red S and soft structures by Alcian blue. The temporal and spatial distribution patterns of different types of GAGs: chondroitin-4-sulphate/dermatan sulphate, chondroitin-6-sulphate, chondroitin-0-sulphate and keratan sulphate were addressed by immunohistochemistry using monoclonal antibodies against the different GAGs. The specific pattern obtained with the different antibodies suggests a unique role of the different GAG types in pattern formation and mineralization. In addition, the distribution of the different GAG types in normal and malformed vertebral columns from 15 g salmon was compared. A changed expression pattern of GAGs was found in the malformed vertebrae, indicating the involvement of these molecules during the pathogenesis. The molecular size of proteoglycans (PGs) in the vertebrae carrying GAGs was analysed with western blotting, and mRNA transcription of the PGs aggrecan, decorin, biglycan, fibromodulin and lumican by real-time qPCR. Our study reveals the importance of GAGs in development of vertebral column also in Atlantic salmon and indicates that a more comprehensive approach is necessary to completely understand the processes involved.

"MedTRIS" (Medical Triage and Registration Informatics System): A Web-based Client Server System for the Registration of Patients Being Treated in First Aid Posts at Public Events and Mass Gatherings.

PubMed

Gogaert, Stefan; Vande Veegaete, Axel; Scholliers, Annelies; Vandekerckhove, Philippe

2016-10-01

First aid (FA) services are provisioned on-site as a preventive measure at most public events. In Flanders, Belgium, the Belgian Red Cross-Flanders (BRCF) is the major provider of these FA services with volunteers being deployed at approximately 10,000 public events annually. The BRCF has systematically registered information on the patients being treated in FA posts at major events and mass gatherings during the last 10 years. This information has been collected in a web-based client server system called "MedTRIS" (Medical Triage and Registration Informatics System). MedTRIS contains data on more than 200,000 patients at 335 mass events. This report describes the MedTRIS architecture, the data collected, and how the system operates in the field. This database consolidates different types of information with regards to FA interventions in a standardized way for a variety of public events. MedTRIS allows close monitoring in "real time" of the situation at mass gatherings and immediate intervention, when necessary; allows more accurate prediction of resources needed; allows to validate conceptual and predictive models for medical resources at (mass) public events; and can contribute to the definition of a standardized minimum data set (MDS) for mass-gathering health research and evaluation. Gogaert S , Vande veegaete A , Scholliers A , Vandekerckhove P . "MedTRIS" (Medical Triage and Registration Informatics System): a web-based client server system for the registration of patients being treated in first aid posts at public events and mass gatherings. Prehosp Disaster Med. 2016;31(5):557-562.

Magnetic Susceptibility: A Practical Introduction.

ERIC Educational Resources Information Center

Greenaway, A. M.; Trail, L. E.

1983-01-01

Describes an experiment in which students: (1) synthesize tris(acetylacetonato)iron(III), tris(diethyldithiocarbamato)iron(III), and chlorobis(diethyldithiocarbmamato)iron(III); (2) are given a sample of potassium hexocyanoferrate(III); and (3) are then asked to measure the room temperature of these samples using the Guoy technique. Background…

Harnessing redox activity for the formation of uranium tris(imido) compounds

NASA Astrophysics Data System (ADS)

Anderson, Nickolas H.; Odoh, Samuel O.; Yao, Yiyi; Williams, Ursula J.; Schaefer, Brian A.; Kiernicki, John J.; Lewis, Andrew J.; Goshert, Mitchell D.; Fanwick, Phillip E.; Schelter, Eric J.; Walensky, Justin R.; Gagliardi, Laura; Bart, Suzanne C.

2014-10-01

Classically, late transition-metal organometallic compounds promote multielectron processes solely through the change in oxidation state of the metal centre. In contrast, uranium typically undergoes single-electron chemistry. However, using redox-active ligands can engage multielectron reactivity at this metal in analogy to transition metals. Here we show that a redox-flexible pyridine(diimine) ligand can stabilize a series of highly reduced uranium coordination complexes by storing one, two or three electrons in the ligand. These species reduce organoazides easily to form uranium-nitrogen multiple bonds with the release of dinitrogen. The extent of ligand reduction dictates the formation of uranium mono-, bis- and tris(imido) products. Spectroscopic and structural characterization of these compounds supports the idea that electrons are stored in the ligand framework and used in subsequent reactivity. Computational analyses of the uranium imido products probed their molecular and electronic structures, which facilitated a comparison between the bonding in the tris(imido) structure and its tris(oxo) analogue.

A biocompatible synthesis of gold nanoparticles by Tris(hydroxymethyl)aminomethane

NASA Astrophysics Data System (ADS)

Chen, Feng; Wang, Yanwei; Ma, Jun; Yang, Guangcan

2014-05-01

Gold nanoparticles' novel properties are widely realized in catalysis, plasmonics, electronics, and biomedical applications. For biomedical application, one challenge is to find a non-toxic chemical and/or physical method of functionalizing gold nanoparticles with biomolecular compounds that can promote efficient binding, clearance, and biocompatibility and to assess their safety to other biological systems and their long-term effects on human health and reproduction. In the present study, we describe a new method by using Tris(hydroxymethyl)aminomethane (Tris), a widely used buffer solvent of nucleic acid and proteins, as the reducing agent for synthesizing gold nanoparticles by one step. It is found that Tris carries out the reduction reactions in relatively mild conditions for biomacromolecules. Particularly, it can be used to modify the DNA during the process of preparation of gold nanoparticles. The morphology and size distribution of gold nanoparticles are consistent and were confirmed by many different approaches including dynamic light scattering (DLS), UV-visible (UV-vis) spectrophotometry, atomic force microscopy (AFM), and transmission electron microscopy (TEM).

Stabilization of Quinapril by Incorporating Hydrogen Bonding Interactions

PubMed Central

Roy, B. N.; Singh, G. P.; Godbole, H. M.; Nehate, S. P.

2009-01-01

In the present study stability of various known solvates of quinapril hydrochloride has been compared with nitromethane solvate. Nitromethane solvate was found to be more stable compared to other known solvates. Single crystal X-ray diffraction analysis of quinapril nitromethane solvate shows intermolecular hydrogen bonding between quinapril molecule and nitromethane. Stabilization of quinapril by forming strong hydrogen bonding network as in case of co-crystals was further studied by forming co-crystal with tris(hydroxymethyl)amino methane. Quinapril free base forms a stable salt with tris(hydroxymethyl)amino methane not reported earlier. Quinapril tris(hydroxymethyl)amino methane salt found to be stable even at 80° for 72 h i.e. hardly any formation of diketopiperazine and diacid impurity. As expected single crystal X-ray diffraction analysis reveals tris(hydroxymethyl)amino methane salt of quinapril shows complex hydrogen bonding network between the two entities along with ionic bond. The properties of this stable salt - stable in solid as well as solution phase, might lead to an alternate highly stable formulation. PMID:20502545

Energy metabolism in Desulfovibrio vulgaris Hildenborough: insights from transcriptome analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pereira, Patricia M.; He, Qiang; Valente, Filipa M.A.

2007-11-01

Sulphate-reducing bacteria are important players in the global sulphur and carbon cycles, with considerable economical and ecological impact. However, the process of sulphate respiration is still incompletely understood. Several mechanisms of energy conservation have been proposed, but it is unclear how the different strategies contribute to the overall process. In order to obtain a deeper insight into the energy metabolism of sulphate-reducers whole-genome microarrays were used to compare the transcriptional response of Desulfovibrio vulgaris Hildenborough grown with hydrogen/sulphate, pyruvate/sulphate, pyruvate with limiting sulphate, and lactate/thiosulphate, relative to growth in lactate/sulphate. Growth with hydrogen/sulphate showed the largest number of differentially expressedmore » genes and the largest changes in transcript levels. In this condition the most up-regulated energy metabolism genes were those coding for the periplasmic [NiFeSe]hydrogenase, followed by the Ech hydrogenase. The results also provide evidence for the involvement of formate cycling and the recently proposed ethanol pathway during growth in hydrogen. The pathway involving CO cycling is relevant during growth on lactate and pyruvate, but not during growth in hydrogen as the most down-regulated genes were those coding for the CO-induced hydrogenase. Growth on lactate/thiosulphate reveals a down-regulation of several energymetabolism genes similar to what was observed in the presence of nitrite. This study identifies the role of several proteins involved in the energy metabolism of D. vulgaris and highlights several novel genes related to this process, revealing a more complex bioenergetic metabolism than previously considered.« less

New tools for evaluating protein tyrosine sulphation: Tyrosyl Protein Sulphotransferases (TPSTs) are novel targets for RAF protein kinase inhibitors.

PubMed

Byrne, Dominic P; Li, Yong; Ngamlert, Pawin; Ramakrishnan, Krithika; Eyers, Claire E; Wells, Carrow; Drewry, David H; Zuercher, William J; Berry, Neil G; Fernig, David G; Eyers, Patrick A

2018-06-22

Protein tyrosine sulphation is a post-translational modification best known for regulating extracellular protein-protein interactions. Tyrosine sulphation is catalysed by two Golgi-resident enzymes termed Tyrosyl Protein Sulpho Transferases (TPSTs) 1 and 2, which transfer sulphate from the co-factor PAPS (3'-phosphoadenosine 5'-phosphosulphate) to a context-dependent tyrosine in a protein substrate. A lack of quantitative tyrosine sulphation assays has hampered the development of chemical biology approaches for the identification of small molecule inhibitors of tyrosine sulphation. In this paper, we describe the development of a non-radioactive mobility-based enzymatic assay for TPST1 and TPST2, through which the tyrosine sulphation of synthetic fluorescent peptides can be rapidly quantified. We exploit ligand binding and inhibitor screens to uncover a susceptibility of TPST1 and TPST2 to different classes of small molecules, including the anti-angiogenic compound suramin and the kinase inhibitor rottlerin. By screening the Published Kinase Inhibitor Set (PKIS), we identified oxindole-based inhibitors of the Ser/Thr kinase RAF as low micromolar inhibitors of TPST1 and TPST2.  Interestingly, unrelated RAF inhibitors, exemplified by the dual BRAF/VEGFR2 inhibitor RAF265, were also TPST inhibitors in vitro We propose that target-validated protein kinase inhibitors could be repurposed, or redesigned, as more-specific TPST inhibitors to help evaluate the sulphotyrosyl proteome. Finally, we speculate that mechanistic inhibition of cellular tyrosine sulphation might be relevant to some of the phenotypes observed in cells exposed to anionic TPST ligands and RAF protein kinase inhibitors. ©2018 The Author(s).

Resistance of class C fly ash belite cement to simulated sodium sulphate radioactive liquid waste attack.

PubMed

Guerrero, A; Goñi, S; Allegro, V R

2009-01-30

The resistance of class C fly ash belite cement (FABC-2-W) to concentrated sodium sulphate salts associated with low level wastes (LLW) and medium level wastes (MLW) is discussed. This study was carried out according to the Koch and Steinegger methodology by testing the flexural strength of mortars immersed in simulated radioactive liquid waste rich in sulphate (48,000 ppm) and demineralised water (used as a reference), at 20 degrees C and 40 degrees C over a period of 180 days. The reaction mechanisms of sulphate ion with the mortar was carried out through a microstructure study, which included the use of Scanning electron microscopy (SEM), porosity and pore-size distribution and X-ray diffraction (XRD). The results showed that the FABC mortar was stable against simulated sulphate radioactive liquid waste (SSRLW) attack at the two chosen temperatures. The enhancement of mechanical properties was a result of the formation of non-expansive ettringite inside the pores and an alkaline activation of the hydraulic activity of cement promoted by the ingress of sulphate. Accordingly, the microstructure was strongly refined.

Effects of agmatine sulphate on facial nerve injuries.

PubMed

Surmelioglu, O; Sencar, L; Ozdemir, S; Tarkan, O; Dagkiran, M; Surmelioglu, N; Tuncer, U; Polat, S

2017-03-01

To evaluate the effect of agmatine sulphate on facial nerve regeneration after facial nerve injury using electron and light microscopy. The study was performed on 30 male Wistar albino rats split into: a control group, a sham-treated group, a study control group, an anastomosis group, and an anastomosis plus agmatine sulphate treatment group. The mandibular branch of the facial nerve was dissected, and a piece was removed for histological and electron microscopic examination. Regeneration was better in the anastomosis group than in the study control group. However, the best regeneration findings were seen in the agmatine sulphate treatment group. There was a significant difference between the agmatine group and the others in terms of median axon numbers (p < 0.004) and diameters (p < 0.004). Agmatine sulphate treatment with anastomosis in traumatic facial paralysis may enhance nerve regeneration.

Sulphur flux through the sulphate assimilation pathway is differently controlled by adenosine 5'-phosphosulphate reductase under stress and in transgenic poplar plants overexpressing gamma-ECS, SO, or APR.

PubMed

Scheerer, Ursula; Haensch, Robert; Mendel, Ralf R; Kopriva, Stanislav; Rennenberg, Heinz; Herschbach, Cornelia

2010-01-01

Sulphate assimilation provides reduced sulphur for the synthesis of cysteine, methionine, and numerous other essential metabolites and secondary compounds. The key step in the pathway is the reduction of activated sulphate, adenosine 5'-phosphosulphate (APS), to sulphite catalysed by APS reductase (APR). In the present study, [(35)S]sulphur flux from external sulphate into glutathione (GSH) and proteins was analysed to check whether APR controls the flux through the sulphate assimilation pathway in poplar roots under some stress conditions and in transgenic poplars. (i) O-Acetylserine (OAS) induced APR activity and the sulphur flux into GSH. (ii) The herbicide Acetochlor induced APR activity and results in a decline of GSH. Thereby the sulphur flux into GSH or protein remained unaffected. (iii) Cd treatment increased APR activity without any changes in sulphur flux but lowered sulphate uptake. Several transgenic poplar plants that were manipulated in sulphur metabolism were also analysed. (i) Transgenic poplar plants that overexpressed the gamma-glutamylcysteine synthetase (gamma-ECS) gene, the enzyme catalysing the key step in GSH formation, showed an increase in sulphur flux into GSH and sulphate uptake when gamma-ECS was targeted to the cytosol, while no changes in sulphur flux were observed when gamma-ECS was targeted to plastids. (ii) No effect on sulphur flux was observed when the sulphite oxidase (SO) gene from Arabidopsis thaliana, which catalyses the back reaction of APR, that is the reaction from sulphite to sulphate, was overexpressed. (iii) When Lemna minor APR was overexpressed in poplar, APR activity increased as expected, but no changes in sulphur flux were observed. For all of these experiments the flux control coefficient for APR was calculated. APR as a controlling step in sulphate assimilation seems obvious under OAS treatment, in gamma-ECS and SO overexpressing poplars. A possible loss of control under certain conditions, that is Cd treatment, Acetochlor treatment, and in APR overexpressing poplar, is discussed.

Fluorescent tris-imidazolium sensors for picric acid explosive.

PubMed

Roy, Bijan; Bar, Arun Kumar; Gole, Bappaditya; Mukherjee, Partha Sarathi

2013-02-01

Two new anthracene-functionalized fluorescent tris-imidazolium salts have been synthesized, characterized, and proven to be selective sensors for picric acid, which is a common constituent of many powerful explosives. Theoretical studies revealed an unusual ground-state electron transfer from picrate anion to the sensor molecules.

Abnormal Excretion of Corticosteroid Sulphates in Patients with Breast Cancer

PubMed Central

Ghosh, P. C.; Lockwood, E.; Pennington, G. W.

1973-01-01

In a preliminary study, the 24-hour urinary excretion of corticosteroid sulphates and free cortisol have been measured in a group of patients with breast cancer and compared with the excretion of the same compounds in a group of normal women of similar age. Excretion of corticosteroid sulphates in the breast cancer group was found to be markedly raised. In a small number of patients with localized cancer of sites other than the breast the level of corticosteroid sulphate was not raised. If proved metastases were present a noticeable rise was observed. Imagesp330-a PMID:4685623

Preparation and Physiological activities of sulphated derivative extracted from corn bran

NASA Astrophysics Data System (ADS)

Mo, Qing; Dai, Linghao; Ma, Jianjun; Zhao, Xiaojing; Zhu, Linghui

2017-05-01

In the present study, the sulphated derivative (S-CBP) with the degree of substitution (0.46) was successfully prepared from the polysaccharide extracted from corn bran. Compared with native polysaccharide, the structures of the sulphated derivative were confirmed by FT-IR and SEC-LLS and the molecular weight were changed by chemical modification. Sulfation enhanced the antioxidant activities in a dose-dependent way, which seemed to be dependent on the character of the substituted group. The results suggest that the sulphated derivative, extracted from corn bran, are potential natural antioxidant and blood fat reduce agent.

Formulation procedure and spectral data for a coatings system optimally employing the high intrinsic reflectance of barium sulphate

NASA Technical Reports Server (NTRS)

Schutt, J. B.; Stromberg, E.; Shai, C. M.; Arens, J. F.

1972-01-01

The use of polyvinyl alcohol as a binder for barium sulphate does not allow the intrinsically high reflectance of this material in the near vacuum ultraviolet to be optimally employed. In an effort to better utilize this property, completely inorganic coatings systems are described, where from the intrinsically high reflectance of barium sulphate in this spectral region can be gotten. Potassium sulphate turns out to be the preferred binder. Compositions, formulating procedures, and application techniques are included. For completeness, absolute and relative reflectance data are included for intra- and intersystem comparisons.

New potential markers for the detection of boldenone misuse.

PubMed

Gómez, C; Pozo, O J; Geyer, H; Marcos, J; Thevis, M; Schänzer, W; Segura, J; Ventura, R

2012-11-01

Boldenone is one of the most frequently detected anabolic androgenic steroids in doping control analysis. Boldenone misuse is commonly detected by the identification of the active drug and its main metabolite, 5β-androst-1-en-17β-ol-3-one (BM1), by gas chromatography-mass spectrometry (GC-MS), after previous hydrolysis with β-glucuronidase enzymes, extraction and derivatization steps. However, some cases of endogenous boldenone and BM1 have been reported. Nowadays, when these compounds are detected in urine at low concentrations, isotope ratio mass spectrometry (IRMS) analysis is needed to confirm their exogenous origin. The aim of the present study was to identify boldenone metabolites conjugated with sulphate and to evaluate their potential to improve the detection of boldenone misuse in sports. Boldenone was administered to a healthy volunteer and urine samples were collected up to 56h after administration. After a liquid-liquid extraction with ethyl acetate, urine extracts were analysed by liquid chromatography tandem mass spectrometry (LC-MS/MS) using electrospray ionisation in negative mode by monitoring the transition of m/z 365-350, specific for boldenone sulphate. Boldenone sulphate was identified in the excretion study urine samples and, moreover, another peak with the same transition was observed. Based on the MS/MS behaviour the metabolite was identified as epiboldenone sulphate. The identity was confirmed by isolation of the LC peak, solvolysis and comparison of the retention time and MS/MS spectra with an epiboldenone standard. These sulphated metabolites have not been previously reported in humans and although they account for less than 1% of the administered dose, they were still present in urine when the concentrations of the major metabolites, boldenone and BM1, were at the level of endogenous origin. The sulphated metabolites were also detected in 10 urine samples tested positive to boldenone and BM1 by GC-MS. In order to verify the usefulness of these new metabolites to discriminate between endogenous and exogenous origin of boldenone, four samples containing endogenous boldenone and BM1, confirmed by IRMS, were analysed. In 3 of the 4 samples, neither boldenone sulphate nor epiboldenone sulphate were detected, confirming that these metabolites were mainly detected after exogenous administration of boldenone. In contrast, boldenone sulphate and, in some cases, epiboldenone sulphate were present in samples with low concentrations of exogenous boldenone and BM1. Thus, boldenone and epiboldenone sulphates are additional markers for the exogenous origin of boldenone and they can be used to reduce the number of samples to be analysed by IRMS. In samples with boldenone and BM1 at the concentrations suspicion for endogenous origin, only if boldenone and epiboldenone sulphates are present, further analysis by IRMS will be needed to confirm exogenous origin. Copyright © 2012 Elsevier Ltd. All rights reserved.

Swelling kinetics of spray-dried chitosan acetate assessed by magnetic resonance imaging and their relation to drug release kinetics of chitosan matrix tablets.

PubMed

Huanbutta, Kampanart; Sriamornsak, Pornsak; Limmatvapirat, Sontaya; Luangtana-anan, Manee; Yoshihashi, Yasuo; Yonemochi, Etsuo; Terada, Katsuhide; Nunthanid, Jurairat

2011-02-01

Magnetic resonance imaging (MRI) was used to assess in situ swelling behaviors of spray-dried chitosan acetate (CSA) in 0.1N HCl, pH 6.8 and pH 5.0 Tris-HCl buffers. The in vitro drug releases from CSA matrix tablets containing the model drugs, diclofenac sodium and theophylline were investigated in all media using USP-4 apparatus. The effect of chitosan molecular weight, especially in pH 6.8 Tris-HCl, was also studied. In 0.1N HCl, the drug release from the matrix tablets was the lowest in relation to the highest swelling of CSA. The swelling kinetics in Tris-HCl buffers are Fickian diffusion according to their best fit to Higuchi's model as well as the drug release kinetics in all the media. The high swelling rate (k(s)(')) was found to delay the drug release rate (k'). The linear relationship between the swelling and fractions of drug release in Tris-HCl buffers was observed, indicating an important role of the swelling on controlling the drug release mechanism. Additionally, CSA of 200 and 800 kDa chitosan did not swell in pH 6.8 Tris-HCl but disintegrated into fractions, and the drug release from the matrix tablets was the highest. Copyright © 2010 Elsevier B.V. All rights reserved.

Tris-base buffer: a promising new inhibitor for cancer progression and metastasis.

PubMed

Ibrahim-Hashim, Arig; Abrahams, Dominique; Enriquez-Navas, Pedro M; Luddy, Kim; Gatenby, Robert A; Gillies, Robert J

2017-07-01

Neutralizing tumor external acidity with oral buffers has proven effective for the prevention and inhibition of metastasis in several cancer mouse models. Solid tumors are highly acidic as a result of high glycolysis combined with an inadequate blood supply. Our prior work has shown that sodium bicarbonate, imidazole, and free-base (but not protonated) lysine are effective in reducing tumor progression and metastasis. However, a concern in translating these results to clinic has been the presence of counter ions and their potential undesirable side effects (e.g., hypernatremia). In this work, we investigate tris(hydroxymethyl)aminomethane, (THAM or Tris), a primary amine with no counter ion, for its effects on metastasis and progression in prostate and pancreatic cancer in vivo models using MRI and bioluminescence imaging. At an ad lib concentration of 200 mmol/L, Tris effectively inhibited metastasis in both models and furthermore led to a decrease in the expression of the major glucose transporter, GLUT-1. Our results also showed that Tris-base buffer (pH 8.4) had no overt toxicity to C3H mice even at higher doses (400 mmol/L). In conclusion, we have developed a novel therapeutic approach to manipulate tumor extracellular pH (pHe) that could be readily adapted to a clinical trial. © 2017 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Effect of silver doping on the elastic properties of CdS nanoparticles

NASA Astrophysics Data System (ADS)

Dey, P. C.; Das, R.

2018-05-01

CdS and Ag doped CdS (CdS/Ag) nanoparticles have been prepared via chemical method from a Cadmium acetate precursor and Thiourea. The synthesized CdS and CdS/Ag nanoparticles have been characterized by the X-ray Diffraction and High Resolution Transmission Electron Microscope. Here, these nanoparticles have been synthesized at room temperature and all the characterization have also been done at room temperature only. The XRD results reveal that the products are crystalline with cubic zinc blende structure. HRTEM images show that the prepared nanoparticles are nearly spherical in shape. Williamson-Hall method and Size-Strain Plot (SSP) have been used to study the individual contribution of crystalline sizes and lattice strain on the peak broadening of the CdS and CdS/Ag nanoparticles. The different modified model of Williamson-Hall method such as, uniform deformation model, uniform stress deformation model and uniform energy density deformation model and SSP method have been used to calculate the different physical parameter such as lattice strain, stress and energy density for all diffraction peaks of the XRD, corresponding to the CdS and silver doped CdS (CdS/Ag). The obtained results reveal that the average particle size of the prepared CdS and CdS/Ag nanoparticles estimated from the HRTEM images, Williamson-Hall analysis and SSP method are highly correlated with each other. Further, all these result confirms that doping of Ag significantly affects the elastic properties of CdS.

Sulphate reduction and nitrogen fixation rates associated with roots, rhizomes and sediments from Zostera noltii and Spartina maritima meadows.

PubMed

Nielsen, L B; Finster, K; Welsh, D T; Donelly, A; Herbert, R A; de Wit, R; Lomstein, B A

2001-01-01

Sulphate reduction rates (SRR) and nitrogen fixation rates (NFR) associated with isolated roots, rhizomes and sediment from the rhizosphere of the marine macrophytes Zostera noltii and Spartina maritima, and the presence and distribution of Bacteria on the roots and rhizomes, were investigated. Between 1% and 3% of the surface area of the roots and rhizomes of both macrophytes were colonized by Bacteria. Bacteria on the surfaces of S. maritima roots and rhizomes were evenly distributed, while the distribution of Bacteria on Z. noltii roots and rhizomes was patchy. Root- and rhizome-associated SRR and NFR were always higher than rates in the bulk sediment. In particular, nitrogen fixation associated with the roots and rhizomes was 41-650-fold higher than in the bulk sediment. Despite the fact that sulphate reduction was elevated on roots and rhizomes compared with bulk sediment, the contribution of plant-associated sulphate reduction to overall sulphate reduction was small (< or =11%). In contrast, nitrogen fixation associated with the roots and rhizomes accounted for 31% and 91% of the nitrogen fixed in the rhizosphere of Z. noltii and S. maritima respectively. In addition, plant-associated nitrogen fixation could supply 37-1,613% of the nitrogen needed by the sulphate-reducing community. Sucrose stimulated nitrogen fixation and sulphate reduction significantly in the root and rhizome compartments of both macrophytes, but not in the bulk sediment.

Mesophilic and thermophilic anaerobic digestion of sulphate-containing wastewaters.

PubMed

Colleran, E; Pender, S

2002-01-01

The effect of sulphate at an influent chemical oxygen demand (COD):sulphate ratio of 4 on the operational performance of anaerobic hybrid reactors treating molasses wastewater was investigated under mesophilic and thermophilic conditions in a long-term laboratory-scale study over a 1,081 day period. The presence of sulphate reduced the COD removal efficiency under both mesophilic and thermophilic conditions. At 55 degrees C, effluent acetate levels were consistently greater than 4000 mg l(-1) indicating that thermophilic acetate-utilising methane-producing bacteria (MPB) or sulphate-reducing bacteria (SRB) had not developed in the reactor under the conditions applied. At 37 degrees C, acetate was exclusively utilised by acetoclastic methanogens, whereas H2-utilising SRB predominated over H2-utilising MPB in the competition for hydrogen. By contrast, hydrogenotrophic MPB were shown to outcompete H2-utilising SRB during long-term thermophilic operation. 16SrDNA analysis of the seed sludge and reactor biomass on conclusion of the 37 degrees C and 55 degrees C trials illustrated that the dominant methanogen present on conclusion of the thermophilic trial in the absence of influent sulphate was related to Methanocorpusculum parvuum, and was capable of growth on both acetate and hydrogen. By contrast, an organism closely related to Methanobacterium thermoautotrophicum was the dominant methanogen present in the sulphate-fed reactor on completion of the thermophilic trial.

Oral zinc for treating diarrhoea in children

PubMed Central

Lazzerini, Marzia; Wanzira, Humphrey

2016-01-01

Background In developing countries, diarrhoea causes around 500,000 child deaths annually. Zinc supplementation during acute diarrhoea is currently recommended by the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF). Objectives To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea. Search methods We searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (the Cochrane Library 2016, Issue 5), MEDLINE, Embase, LILACS, CINAHL, mRCT, and reference lists up to 30 September 2016. We also contacted researchers. Selection criteria Randomized controlled trials (RCTs) that compared oral zinc supplementation with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery. Data collection and analysis Both review authors assessed trial eligibility and risk of bias, extracted and analysed data, and drafted the review. The primary outcomes were diarrhoea duration and severity. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using either a fixed-effect or random-effects model) and assessed heterogeneity. We assessed the certainty of the evidence using the GRADE approach. Main results Thirty-three trials that included 10,841 children met our inclusion criteria. Most included trials were conducted in Asian countries that were at high risk of zinc deficiency. Acute diarrhoea There is currently not enough evidence from well-conducted RCTs to be able to say whether zinc supplementation during acute diarrhoea reduces death or number of children hospitalized (very low certainty evidence). In children older than six months of age, zinc supplementation may shorten the average duration of diarrhoea by around half a day (MD −11.46 hours, 95% CI −19.72 to −3.19; 2581 children, 9 trials, low certainty evidence), and probably reduces the number of children whose diarrhoea persists until day seven (RR 0.73, 95% CI 0.61 to 0.88; 3865 children, 6 trials, moderate certainty evidence). In children with signs of malnutrition the effect appears greater, reducing the duration of diarrhoea by around a day (MD −26.39 hours, 95% CI −36.54 to −16.23; 419 children, 5 trials, high certainty evidence). Conversely, in children younger than six months of age, the available evidence suggests zinc supplementation may have no effect on the mean duration of diarrhoea (MD 5.23 hours, 95% CI −4.00 to 14.45; 1334 children, 2 trials, moderate certainty evidence), or the number of children who still have diarrhoea on day seven (RR 1.24, 95% CI 0.99 to 1.54; 1074 children, 1 trial, moderate certainty evidence). None of the included trials reported serious adverse events. However, zinc supplementation increased the risk of vomiting in both age groups (children greater than six months of age: RR 1.57, 95% CI 1.32 to 1.86; 2605 children, 6 trials, moderate certainty evidence; children less than six months of age: RR 1.54, 95% CI 1.05 to 2.24; 1334 children, 2 trials, moderate certainty evidence). Persistent diarrhoea In children with persistent diarrhoea, zinc supplementation probably shortens the average duration of diarrhoea by around 16 hours (MD −15.84 hours, 95% CI −25.43 to −6.24; 529 children, 5 trials, moderate certainty evidence). Authors' conclusions In areas where the prevalence of zinc deficiency or the prevalence of malnutrition is high, zinc may be of benefit in children aged six months or more. The current evidence does not support the use of zinc supplementation in children less six months of age, in well-nourished children, and in settings where children are at low risk of zinc deficiency. Oral zinc supplementation for treating diarrhoea in children In low- and middle-income countries, millions of children suffer from severe diarrhoea every year and many die from dehydration. Giving fluids by mouth (using an oral rehydration solution (ORS)) has been shown to save children's lives, but it has no effect on the length of time the children suffer with diarrhoea. Zinc supplementation could help reduce the duration and the severity of diarrhoea, and therefore have an additional benefit over ORS in reducing children mortality. What is oral zinc and how may it shorten the duration and severity of diarrhoea Zinc is usually given as zinc sulphate, zinc acetate, or zinc gluconate, which are all water-soluble compounds. The World Health Organization (WHO) and the United Nations Children's Fund (UNICEF) recommend 10 mg to 20 mg of zinc per day for children with diarrhoea. There are several mechanism of action of zinc on acute diarrhoea, some of which are specific to the gastrointestinal system: zinc restores mucosal barrier integrity and enterocyte brush-border enzyme activity, it promotes the production of antibodies and circulating lymphocytes against intestinal pathogens, and has a direct effect on ion channels, acting as a potassium channel blocker of adenosine 3-5-cyclic monophosphate-mediated chlorine secretion. Cochrane researchers examined the evidence available up to 30 September 2016. What the evidence in the review suggests Thirty-three trials that included 10,841 children met the inclusion criteria of this review. Among children with acute diarrhoea, we don't know if treating children with zinc has an effect on death or number of children hospitalized (very low certainty evidence). In children older than six months, zinc supplementation may shorten the average duration of diarrhoea by around half a day (low certainty evidence), and probably reduces the number of children whose diarrhoea persists until day seven (moderate certainty evidence). In children with signs of malnutrition the effect appears greater, reducing the duration of diarrhoea by around a day (high certainty evidence). Conversely, in children younger than six months, the available evidence suggests zinc supplementation may have no effect on the mean duration of diarrhoea (moderate certainty evidence), or the number of children who still have diarrhoea on day seven (moderate certainty evidence). Zinc supplementation increased the risk of vomiting in both age groups (moderate certainty evidence). No other adverse effects were reported. Among children with persistent diarrhoea, zinc supplementation probably shortens the average duration of diarrhoea by around 16 hours (moderate certainty) but it probably increases the risk of vomiting (moderate certainty evidence). In areas where the prevalence of zinc deficiency or the prevalence of malnutrition is high, zinc may be of benefit in children aged six months or more. The current evidence does not support the use of zinc supplementation in children less six months of age, in well-nourished children, and in settings where children are at low risk of zinc deficiency. PMID:27996088

The Effect of Sulphate Anions on the Ultrafine Titania Nucleation

NASA Astrophysics Data System (ADS)

Kotsyubynsky, Volodymyr O.; Myronyuk, Ivan F.; Chelyadyn, Volodymyr L.; Hrubiak, Andriy B.; Moklyak, Volodymyr V.; Fedorchenko, Sofia V.

2017-05-01

The phenomenological model of sulphate anions effect on the nanodispersed titania synthesis during hydrolysis of titanium tetrachloride was studied. It was proposed that both chelating and bridging bidentate complexes formation between sulphate anions and octahedrally coordinated [Ti(OH)h(OH2)6-h](4-h)+ mononers is the determinative factor for anatase phase nucleation.

Catalytic asymmetric total synthesis of (+)-yohimbine.

PubMed

Mergott, Dustin J; Zuend, Stephan J; Jacobsen, Eric N

2008-03-06

The total synthesis of (+)-yohimbine was achieved in 11 steps and 14% overall yield. The absolute configuration was established through a highly enantioselective thiourea-catalyzed acyl-Pictet-Spengler reaction, and the remaining 4 stereocenters were set simultaneously in a substrate-controlled intramolecular Diels-Alder reaction.

TRIBUTYLTIN ISOTHIOCYANATE AND ISOCYANIDE,

DTIC Science & Technology

Infrared evidence was used to demonstrate that tributyltin isothiocyanate is formed when certain tributyltin compounds are reacted with inorganic...thiocyanates or thiourea. Molecular refraction data supporting this contention are also reported. The preparation of tributyltin isothiocyanate by several different methods and of tributyltin succinimide is described. (Author)

Determination of the Solubility Limit of Tris(dibenzylideneacetone) Dipalladium(0) in Tetrahydrofuran/Water Mixtures

ERIC Educational Resources Information Center

Franzen, Stefan

2011-01-01

Determination of the solubility limit of a strongly colored organometallic reagent in a mixed-solvent system provides an example of quantitative solubility measurement appropriate to understand polymer, nanoparticle, and other macromolecular aggregation processes. The specific example chosen involves a solution of tris(dibenzylideneacetone)…

40 CFR 721.1579 - 1,2,4-Benzenetricarboxylic acid, tris [4-(ethenyloxy) butyl] ester.

Code of Federal Regulations, 2011 CFR

2011-07-01

... [4-(ethenyloxy) butyl] ester. 721.1579 Section 721.1579 Protection of Environment ENVIRONMENTAL...-(ethenyloxy) butyl] ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,2,4-benzenetricarboxylic acid, tris [4-(ethenyloxy) butyl] ester (PMN P...

40 CFR 721.1579 - 1,2,4-Benzenetricarboxylic acid, tris [4-(ethenyloxy) butyl] ester.

Code of Federal Regulations, 2010 CFR

2010-07-01

... [4-(ethenyloxy) butyl] ester. 721.1579 Section 721.1579 Protection of Environment ENVIRONMENTAL...-(ethenyloxy) butyl] ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,2,4-benzenetricarboxylic acid, tris [4-(ethenyloxy) butyl] ester (PMN P...

GC/FT-IR ANALYSIS OF THE THERMALLY LABILE COMPOUND TRIS (2,3-DIBROMOPROPYL) PHOSPHATE

EPA Science Inventory

A fast and convenient GC method has been developed for a compound [tris(2,3-dibromopropyl)phosphate] that poses a difficult analytical problem for both GC (thermal instability/low volatility) and LC (not amenable to commonly available, sensitive detectors) analysis. his method em...

Synthesis Characterization and Decomposition Studies of tris[N-N-dibenzyidithocarbaso)Indium (III) Chemical Spray Deposition of Polycrystalline CuInS2 on Copper Films

NASA Technical Reports Server (NTRS)

Hehemann, David G.; Lau, J. Eva; Harris, Jerry D.; Hoops, Michael D.; Duffy, Norman V.

2005-01-01

This paper presents the results of the synthesis characterization and decomposition studies of tris[N-N-dibenzyidithocarbaso)Indium (III) with chemical spray deposition of polycrystalline CuInS2 on Copper Films.

Evidence for biological activity in mineralization of secondary sulphate deposits in a basaltic environment: implications for the search for life in the Martian subsurface

DOE Office of Scientific and Technical Information (OSTI.GOV)

C. Doc Richardson; Nancy W. Hinman; Jill R. Scott

Evidence of microbial activity associated with mineralization of secondary Na-sulphate minerals (thenardite, mirabilite) in the basaltic subsurface of Craters of the Moon National Monument (COM), Idaho were examined by scanning electron microscopy, X-ray diffraction, laser desorption Fourier transform ion cyclotron resonance mass spectrometry (LD-FTICR-MS), Fourier transform infrared spectroscopy (FTIR) and isotope ratio mass spectrometry. Peaks suggestive of bio/organic compounds were observed in the secondary Na-sulphate deposits by LD-FTICR-MS. FTIR provided additional evidence for the presence of bio/organic compounds. Sulphur fractionation was explored to assist in determining if microbes may play a role in oxidizing sulphur. The presence of bio/organic compoundsmore » associated with Na-sulphate deposits, along with the necessity of oxidizing reduced sulphur to sulphate, suggests that biological activity may be involved in the formation of these secondary minerals. The secondary Na-sulphate minerals probably form from the overlying basalt through leached sodium ions and sulphate ions produced by bio-oxidation of Fe-sulphide minerals. Since the COM basalts are one of the most comparable terrestrial analogues for their Martian counterparts, the occurrence of biological activity in the formation of sulphate minerals at COM has direct implications for the search for life on Mars. In addition, the presence of caves on Mars suggests the importance of these environments as possible locations for growth and preservation of microbial activity. Therefore, understanding the physiochemical pathways of abiotic and biotic mineralization in the COM subsurface and similar basaltic settings has direct implications for the search for extinct or extant life on Mars.« less

Sulphur limitation and early sulphur deficiency responses in poplar: significance of gene expression, metabolites, and plant hormones

PubMed Central

Honsel, Anne; Kojima, Mikiko; Haas, Richard; Frank, Wolfgang; Sakakibara, Hitoshi; Herschbach, Cornelia; Rennenberg, Heinz

2012-01-01

The influence of sulphur (S) depletion on the expression of genes related to S metabolism, and on metabolite and plant hormone contents was analysed in young and mature leaves, fine roots, xylem sap, and phloem exudates of poplar (Populus tremula×Populus alba) with special focus on early consequences. S depletion was applied by a gradual decrease of sulphate availability. The observed changes were correlated with sulphate contents. Based on the decrease in sulphate contents, two phases of S depletion could be distinguished that were denominated as ‘S limitation’ and ‘early S deficiency’. S limitation was characterized by improved sulphate uptake (enhanced root-specific sulphate transporter PtaSULTR1;2 expression) and reduction capacities (enhanced adenosine 5′-phosphosulphate (APS) reductase expression) and by enhanced remobilization of sulphate from the vacuole (enhanced putative vacuolar sulphate transporter PtaSULTR4;2 expression). During early S deficiency, whole plant distribution of S was impacted, as indicated by increasing expression of the phloem-localized sulphate transporter PtaSULTR1;1 and by decreasing glutathione contents in fine roots, young leaves, mature leaves, and phloem exudates. Furthermore, at ‘early S deficiency’, expression of microRNA395 (miR395), which targets transcripts of PtaATPS3/4 (ATP sulphurylase) for cleavage, increased. Changes in plant hormone contents were observed at ‘early S deficiency’ only. Thus, S depletion affects S and plant hormone metabolism of poplar during ‘S limitation’ and ‘early S deficiency’ in a time series of events. Despite these consequences, the impact of S depletion on growth of poplar plants appears to be less severe than in Brassicaceae such as Arabidopsis thaliana or Brassica sp. PMID:22162873

Heparin and structurally related polymers attenuate eotaxin-1 (CCL11) release from human airway smooth muscle.

PubMed

Kanabar, V; Page, C P; Simcock, D E; Karner, C; Mahn, K; O'Connor, B J; Hirst, S J

2008-06-01

The glycosaminoglycan heparin has anti-inflammatory activity and is exclusively found in mast cells, which are localized within airway smooth muscle (ASM) bundles of asthmatic airways. Interleukin (IL)-13 induces the production of multiple inflammatory mediators from ASM including the eosinophil chemoattractant chemokine, eotaxin-1. Heparin and related glycosaminoglycan polymers having structurally heterogeneous polysaccharide side chains that varied in molecular weight, sulphation and anionic charge were used to identify features of the heparin molecule linked to anti-inflammatory activity. Cultured human ASM cells were stimulated with interleukin (IL)-13 in the absence or presence of heparin and related polymers. Eotaxin-1 was quantified using chemokine antibody arrays and ELISA. Unfractionated heparin attenuated IL-13-dependent eotaxin-1 production and this effect was reproduced with low molecular weight heparins (3 and 6 kDa), demonstrating a minimum activity fragment of at least 3 kDa. N-desulphated, 20% re-N-acetylated heparin (anticoagulant) was ineffective against IL-13-dependent eotaxin-1 production compared with 90% re-N-acetylated (anticoagulant) or O-desulphated (non-anticoagulant) heparin, suggesting a requirement for N-sulphation independent of anticoagulant activity. Other sulphated molecules with variable anionic charge and molecular weight exceeding 3 kDa (dextran sulphate, fucoidan, chondroitin sulphate B) inhibited IL-13-stimulated eotaxin-1 release to varying degrees. However, non-sulphated dextran had no effect. Inhibition of IL-13-dependent eotaxin-1 release by heparin involved but did not depend upon sulphation, though loss of N-sulphation reduced the attenuating activity, which could be restored by N-acetylation. This anti-inflammatory effect was also partially dependent on anionic charge, but independent of molecular size above 3 kDa and the anticoagulant action of heparin.

Sulphur limitation and early sulphur deficiency responses in poplar: significance of gene expression, metabolites, and plant hormones.

PubMed

Honsel, Anne; Kojima, Mikiko; Haas, Richard; Frank, Wolfgang; Sakakibara, Hitoshi; Herschbach, Cornelia; Rennenberg, Heinz

2012-03-01

The influence of sulphur (S) depletion on the expression of genes related to S metabolism, and on metabolite and plant hormone contents was analysed in young and mature leaves, fine roots, xylem sap, and phloem exudates of poplar (Populus tremula×Populus alba) with special focus on early consequences. S depletion was applied by a gradual decrease of sulphate availability. The observed changes were correlated with sulphate contents. Based on the decrease in sulphate contents, two phases of S depletion could be distinguished that were denominated as 'S limitation' and 'early S deficiency'. S limitation was characterized by improved sulphate uptake (enhanced root-specific sulphate transporter PtaSULTR1;2 expression) and reduction capacities (enhanced adenosine 5'-phosphosulphate (APS) reductase expression) and by enhanced remobilization of sulphate from the vacuole (enhanced putative vacuolar sulphate transporter PtaSULTR4;2 expression). During early S deficiency, whole plant distribution of S was impacted, as indicated by increasing expression of the phloem-localized sulphate transporter PtaSULTR1;1 and by decreasing glutathione contents in fine roots, young leaves, mature leaves, and phloem exudates. Furthermore, at 'early S deficiency', expression of microRNA395 (miR395), which targets transcripts of PtaATPS3/4 (ATP sulphurylase) for cleavage, increased. Changes in plant hormone contents were observed at 'early S deficiency' only. Thus, S depletion affects S and plant hormone metabolism of poplar during 'S limitation' and 'early S deficiency' in a time series of events. Despite these consequences, the impact of S depletion on growth of poplar plants appears to be less severe than in Brassicaceae such as Arabidopsis thaliana or Brassica sp.

Evidence for biological activity in mineralization of secondary sulphate deposits in a basaltic environment: implications for the search for life in the Martian subsurface

NASA Astrophysics Data System (ADS)

Richardson, C. Doc; Hinman, Nancy W.; Scott, Jill R.

2013-10-01

Evidence of microbial activity associated with mineralization of secondary Na-sulphate minerals (thenardite, mirabilite) in the basaltic subsurface of Craters of the Moon National Monument (COM), Idaho were examined by scanning electron microscopy, X-ray diffraction, laser desorption Fourier transform ion cyclotron resonance mass spectrometry (LD-FTICR-MS), Fourier transform infrared spectroscopy (FTIR) and isotope ratio mass spectrometry. Peaks suggestive of bio/organic compounds were observed in the secondary Na-sulphate deposits by LD-FTICR-MS. FTIR provided additional evidence for the presence of bio/organic compounds. Sulphur fractionation was explored to assist in determining if microbes may play a role in oxidizing sulphur. The presence of bio/organic compounds associated with Na-sulphate deposits, along with the necessity of oxidizing reduced sulphur to sulphate, suggests that biological activity may be involved in the formation of these secondary minerals. The secondary Na-sulphate minerals probably form from the overlying basalt through leached sodium ions and sulphate ions produced by bio-oxidation of Fe-sulphide minerals. Since the COM basalts are one of the most comparable terrestrial analogues for their Martian counterparts, the occurrence of biological activity in the formation of sulphate minerals at COM has direct implications for the search for life on Mars. In addition, the presence of caves on Mars suggests the importance of these environments as possible locations for growth and preservation of microbial activity. Therefore, understanding the physiochemical pathways of abiotic and biotic mineralization in the COM subsurface and similar basaltic settings has direct implications for the search for extinct or extant life on Mars.

Multiple sulphur and oxygen isotopes reveal microbial sulphur cycling in spring waters in the Lower Engadin, Switzerland.

PubMed

Strauss, Harald; Chmiel, Hannah; Christ, Andreas; Fugmann, Artur; Hanselmann, Kurt; Kappler, Andreas; Königer, Paul; Lutter, Andreas; Siedenberg, Katharina; Teichert, Barbara M A

2016-01-01

Highly mineralized springs in the Scuol-Tarasp area of the Lower Engadin and in the Albula Valley near Alvaneu, Switzerland, display distinct differences with respect to the source and fate of their dissolved sulphur species. High sulphate concentrations and positive sulphur (δ(34)S) and oxygen (δ(18)O) isotopic compositions argue for the subsurface dissolution of Mesozoic evaporitic sulphate. In contrast, low sulphate concentrations and less positive or even negative δ(34)S and δ(18)O values indicate a substantial contribution of sulphate sulphur from the oxidation of sulphides in the crystalline basement rocks or the Jurassic sedimentary cover rocks. Furthermore, multiple sulphur (δ(34)S, Δ(33)S) isotopes support the identification of microbial sulphate reduction and sulphide oxidation in the subsurface, the latter is also evident through the presence of thick aggregates of sulphide-oxidizing Thiothrix bacteria.

Unique Mechanism of Action of the Thiourea Drug Isoxyl on Mycobacterium tuberculosis*

PubMed Central

Phetsuksiri, Benjawan; Jackson, Mary; Scherman, Hataichanok; McNeil, Michael; Besra, Gurdyal S.; Baulard, Alain R.; Slayden, Richard A.; DeBarber, Andrea E.; Barry, Clifton E.; Baird, Mark S.; Crick, Dean C.; Brennan, Patrick J.

2016-01-01

The thiourea isoxyl (thiocarlide; 4,4′-diisoamyloxydiphenylthiourea) is known to be an effective anti-tuberculosis drug, active against a range of multidrug-resistant strains of Mycobacterium tuberculosis and has been used clinically. Little was known of its mode of action. We now demonstrate that isoxyl results in a dose-dependent decrease in the synthesis of oleic and, consequently, tuberculostearic acid in M. tuberculosis with complete inhibition at 3 μg/ml. Synthesis of mycolic acid was also affected. The anti-bacterial effect of isoxyl was partially reversed by supplementing growth medium with oleic acid. The specificity of this inhibition pointed to a Δ9-stearoyl desaturase as the drug target. Development of a cell-free assay for Δ9-desaturase activity allowed direct demonstration of the inhibition of oleic acid synthesis by isoxyl. Interestingly, sterculic acid, a known inhibitor of Δ9-desaturases, emulated the effect of isoxyl on oleic acid synthesis but did not affect mycolic acid synthesis, demonstrating the lack of a relationship between the two effects of the drug. The three putative fatty acid desaturases in the M. tuberculosis genome, desA1, desA2, and desA3, were cloned and expressed in Mycobacterium bovis BCG. Cell-free assays and whole cell labeling demonstrated increased Δ9-desaturase activity and oleic acid synthesis only in the desA3-overexpressing strain and an increase in the minimal inhibitory concentration for isoxyl, indicating that DesA3 is the target of the drug. These results validate membrane-bound Δ9-desaturase, DesA3, as a new therapeutic target, and the thioureas as anti-tuberculosis drugs worthy of further development. PMID:14559907

Matrix elimination method for the determination of precious metals in ores using electrothermal atomic absorption spectrometry.

PubMed

Salih, Bekir; Celikbiçak, Omür; Döker, Serhat; Doğan, Mehmet

2007-03-28

Poly(N-(hydroxymethyl)methacrylamide)-1-allyl-2-thiourea) hydrogels, poly(NHMMA-ATU), were synthesized by gamma radiation using (60)Co gamma source in the ternary mixture of NHMMA-ATU-H(2)O. These hydrogels were used for the specific gold, silver, platinum and palladium recovery, pre-concentration and matrix elimination from the solutions containing trace amounts of precious metal ions. Elimination of inorganic matrices such as different transition and heavy metal ions, and anions was performed by adjusting the solution pH to 0.5 that was the selective adsorption pH of the precious metal ions. Desorption of the precious metal ions was performed by using 0.8 M thiourea in 3M HCl as the most efficient desorbing agent with recovery values more than 95%. In the desorption medium, thiourea effect on the atomic signal was eliminated by selecting proper pyrolysis and atomization temperatures for all precious metal ions. Precision and the accuracy of the results were improved in the graphite furnace-atomic absorption spectrometer (GFAAS) measurements by applying the developed matrix elimination method performing the adsorption at pH 0.5. Pre-concentration factors of the studied precious metal ions were found to be at least 1000-fold. Detection limits of the precious metal ions were found to be less than 10 ng L(-1) of the all studied precious metal ions by using the proposed pre-concentration method. Determination of trace levels of the precious metals in the sea-water, anode slime, geological samples and photographic fixer solutions were performed using GFAAS clearly after applying the adsorption-desorption cycle onto the poly(NHMMA-UTU) hydrogels.

Click mechanochemistry: quantitative synthesis of "ready to use" chiral organocatalysts by efficient two-fold thiourea coupling to vicinal diamines.

PubMed

Štrukil, Vjekoslav; Igrc, Marina D; Eckert-Maksić, Mirjana; Friščić, Tomislav

2012-07-02

Mechanochemical methods of neat grinding and liquid-assisted grinding have been applied to the synthesis of mono- and bis(thiourea)s by using the click coupling of aromatic and aliphatic diamines with aromatic isothiocyanates. The ability to modify the reaction conditions allowed the optimization of each reaction, leading to the quantitative formation of chiral bis(thiourea)s with known uses as organocatalysts or anion sensors. Quantitative reaction yields, combined with the fact that mechanochemical reaction conditions avoid the use of bulk solvents, enabled solution-based purification methods (such as chromatography or recrystallization) to be completely avoided. Importantly, by using selected model reactions, we also show that the described mechanochemical reaction procedures can be readily scaled up to at least the one-gram scale. In that way, mechanochemical synthesis provides a facile method to fully transform valuable enantiomerically pure reagents into useful products that can immediately be applied in their designed purpose. This was demonstrated by using some of the mechanochemically prepared reagents as organocatalysts in a model Morita-Baylis-Hillman reaction and as cyanide ion sensors in organic solvents. The use of electronically and sterically hindered ortho-phenylenediamine revealed that mechanochemical reaction conditions can be readily optimized to form either the 1:1 or the 1:2 click-coupling product, demonstrating that reaction stoichiometry can be more efficiently controlled under these conditions than in solution-based syntheses. In this way, it was shown that excellent stoichiometric control by mechanochemistry, previously established for mechanochemical syntheses of cocrystals and coordination polymers, can also be achieved in the context of covalent-bond formation. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of Oversulphated Chondroitin Sulphate and Dermatan Sulphate in unfractionated heparin by (1)H-NMR - Collaborative study for quantification and analytical determination of LoD.

PubMed

McEwen, I; Mulloy, B; Hellwig, E; Kozerski, L; Beyer, T; Holzgrabe, U; Wanko, R; Spieser, J-M; Rodomonte, A

2008-12-01

Oversulphated Chondroitin Sulphate (OSCS) and Dermatan Sulphate (DS) in unfractionated heparins can be identified by nuclear magnetic resonance spectrometry (NMR). The limit of detection (LoD) of OSCS is 0.1% relative to the heparin content. This LoD is obtained at a signal-to-noise ratio (S/N) of 2000:1 of the heparin methyl signal. Quantification is best obtained by comparing peak heights of the OSCS and heparin methyl signals. Reproducibility of less than 10% relative standard deviation (RSD) has been obtained. The accuracy of quantification was good.

Dual functionalized graphene oxide serves as a carrier for delivering oligohistidine- and biotin-tagged biomolecules into cells.

PubMed

Jana, Batakrishna; Mondal, Goutam; Biswas, Atanu; Chakraborty, Indrani; Saha, Abhijit; Kurkute, Prashant; Ghosh, Surajit

2013-11-01

A versatile method of dual chemical functionalization of graphene oxide (GO) with Tris-[nitrilotris(acetic acid)] (Tris-NTA) and biotin for cellular delivery of oligohistidine- and biotin-tagged biomolecules is reported. Orthogonally functionalized GO surfaces with Tris-NTA and biotin to obtain a dual-functionalized GO (DFGO) are prepared and characterized by various spectroscopic and microscopic techniques. Fluorescence microscopic images reveal that DFGO surfaces are capable of binding oligohistidine-tagged biomolecules/proteins and avidin/biotin-tagged biomolecules/proteins orthogonally. The DFGO nanoparticles are non-cytotoxic in nature and can deliver oligohistidine- and biotin-tagged biomolecules simultaneously into the cell. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of tris- and tetrakis(pentafluoroethyl)silanes.

PubMed

Steinhauer, Simon; Bader, Julia; Stammler, Hans-Georg; Ignat'ev, Nikolai; Hoge, Berthold

2014-05-12

The synthesis and complete characterization of functional, highly Lewis acidic tris(pentafluoroethyl)silanes as well as tetrakis(perfluoroalkyl)silanes Si(C2F5)4 and Si(C2F5)3 CF3 by direct fluorination is described. The reaction of SiCl4 with LiC2F5 invariably affords (pentafluoroethyl)fluorosilicates. To avoid silicate formation by fluoride transfer from LiC2F5 the Lewis acidity of the silane has to be decreased by electron-donating substituents, such as dialkylamino groups. The easily accessible Si(C2F5)3 NEt2 is a valuable precursor for a series of tris(pentafluoroethyl)silanes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hydrazinolysis of heparin and other glycosaminoglycans.

PubMed Central

Shaklee, P N; Conrad, H E

1984-01-01

Heparin, carboxy-group-reduced heparin, several sulphated monosaccharides and disaccharides formed from heparin, and a tetrasaccharide prepared from chondroitin sulphate were treated at 100 degrees C with hydrazine containing 1% hydrazine sulphate for periods sufficient to cause complete N-deacetylation of the N-acetylhexosamine residues. Under these hydrazinolysis conditions both the N-sulphate and the O-sulphate substituents on these compounds were completely stable. However, the uronic acid residues were converted into their hydrazide derivatives at rates that depended on the uronic acid structures. Unsubstituted L-iduronic acid residues reacted much more slowly than did unsubstituted D-glucuronic acid or 2-O-sulphated L-iduronic acid residues. The chemical modification of the carboxy groups resulted in a low rate of C-5 epimerization of the uronic acid residues. The hydrazinolysis reaction also caused a partial depolymerization of heparin but not of carboxy-group-reduced heparin. Treatment of the hydrazinolysis products with HNO2 at either pH 4 or pH 1.5 or with HIO3 converted the uronic acid hydrazides back into uronic acid residues. The use of the hydrazinolysis reaction in studies of the structures of uronic acid-containing polymers and the implications of the uronic acid hydrazide formation are discussed. PMID:6421280

Sulphate partitioning into calcite: Experimental verification of pH control and application to seasonality in speleothems

NASA Astrophysics Data System (ADS)

Wynn, Peter M.; Fairchild, Ian J.; Borsato, Andrea; Spötl, Christoph; Hartland, Adam; Baker, Andy; Frisia, Silvia; Baldini, James U. L.

2018-04-01

Carbonate-associated sulphate (CAS) is a useful carrier of palaeoenvironmental information throughout the geologic record, particularly through its stable isotope composition. However, a paucity of experimental data restricts quantitative understanding of sulphate incorporation into carbonates, and consequently CAS concentrations and their diagenetic modifications are rarely interpreted. However, in the case of calcite speleothems, the remarkably high-resolution CAS records which are obtainable via modern microanalytical techniques represent a potentially invaluable source of palaeoenvironmental information. Here, we describe the results of controlled experiments of sulphate co-precipitation with calcite in freshwater solutions where pH, saturation state, and sulphate concentration were varied independently of each other. Solution pH is confirmed as the principal control on sulphate incorporation into calcite. The relative efficiency of incorporation was calculated as a partition coefficient DSO4 = (mSO4/mCO3)solid/(mSO4/mCO3)solution. High crystal growth rates (driven by either pH or saturation state) encouraged higher values of DSO4 because of an increasing concentration of defect sites on crystal surfaces. At low growth rates, DSO4 was reduced due to an inferred competition between sulphate and bicarbonate at the calcite surface. These experimental results are applied to understand the incorporation of sulphate into speleothem calcite. The experimentally determined pH-dependence suggests that strong seasonal variations in cave air PCO2 could account for annual cycles in sulphate concentration observed in stalagmites. Our new experimentally determined values of DSO4 were compared with DSO4 values calculated from speleothem-drip water monitoring from two caves within the Austrian and Italian Alps. At Obir cave, Austria, DSO4 (×105) varies between 11.1 (winter) and 9.0 (summer) and the corresponding figures for Ernesto cave, Italy, are 15.4 (winter) and 14.9 (summer). These values approximate predicted DSO4 values based on our chamber experiments containing both low (2 ppm) and high (20 ppm) sulphate concentrations. Our experimental values of DSO4 obtained at crystal growth rates typical of stalagmites, closely match those observed in other cave sites from around the world. This validates the universality of the controls behind DSO4 and will enhance the use of speleothem CAS as a palaeoenvironmental proxy.

Timescales for migration of atmospherically derived sulphate through an alpine/subalpine watershed, Loch Vale Colorado

USGS Publications Warehouse

Michel, Robert L.; Campbell, Donald H.; Clow, David W.; Turk, John T.

2000-01-01

Sulphur 35, a cosmogenically produced radioisotope with a short half‐life (87 days), was measured in snowpack during 1993–1997 and at four locations within the Loch Vale watershed during 1995–1997. The four sites include the two main drainages in the watershed, Andrews Creek and Icy Brook, a small south facing catchment flowing into Andrews Creek (Andrews Spring 1), and a similar north facing catchment flowing out of a scree field into Icy Brook (Spring 19). Concentrations ranged from a high of almost 50 mBq/L for a sample from Spring 19 in June 1996 to a concentration near the detection limit for a sample from Andrews Creek in April 1997. Sulphur 35 concentrations were normalized to sulphate (as mBq/mg SO4−2) and were decay‐corrected to a Julian day of 90 (April 1) for each year. Snowpack had the highest 35S concentration with an average concentration of 53 mBq/mg SO4−2. Concentrations in the streams were much lower, even when corrected for decay relative to JD 90. The large 35S concentrations found in Spring 19 were the result of increases in concentration due to sublimation and/or evapotranspiration and were lower than snowpack when normalized to sulphate. Using 35S concentrations found in snowpack as of JD 90 as a beginning concentration, the fraction of sulphate in streamflow that was derived from atmospheric deposition within the prior water year was estimated. For Icy Brook and Andrews Creek the fraction of the sulphate in streamflow derived from that year's snowpack and precipitation was low prior to the beginning of the main spring melt, reached a maximum during the period of maximum flow, and decreased as the summer progressed. A calculation of the seasonal flux indicated that about 40% of the sulphate that flowed out of the watershed was derived from atmospheric sulphate deposited during the previous year. This suggests that more than half of the sulphate deposited in the watershed by atmospheric processes during the previous year was removed during the following summer. Thus sulphate retention in alpine watersheds like Loch Vale is very limited, and changes in sulphate deposition should be quickly reflected in stream chemistry.

(Bis)urea and (Bis)thiourea Inhibitors of Lysine-Specific Demethylase 1 as Epigenetic Modulators

PubMed Central

Sharma, Shiv K.; Wu, Yu; Steinbergs, Nora; Crowley, Michael L.; Hanson, Allison S.; Casero, Robert A.; Woster, Patrick M.

2010-01-01

The recently discovered enzyme lysine-specific demethylase 1 (LSD1) plays an important role in the epigenetic control of gene expression, and aberrant gene silencing secondary to LSD1 over expression is thought to contribute to the development of cancer. We recently reported a series of (bis)guanidines and (bis)biguanides that are potent inhibitors of LSD1, and induce the re-expression of aberrantly silenced tumor suppressor genes in tumor cells in vitro. We now report a series of isosteric ureas and thioureas that are also potent inhibitors of LSD1. These compounds induce increases in methylation at the histone 3 lysine 4 (H3K4) chromatin mark, a specific target of LSD1, in Calu-6 lung carcinoma cells. In addition, these analogues increase cellular levels of secreted frizzle-related proteins (SFRP) 2 and 5, and transcription factor GATA4. These compounds represent an important new series of epigenetic modulators with the potential for use as antitumor agents. PMID:20568780

A new polymerizable fluorescent PET chemosensor of fluoride (F-) based on naphthalimide-thiourea dye.

PubMed

Alaei, Parvaneh; Rouhani, Shohre; Gharanjig, Kamaladin; Ghasemi, Jahanbakhsh

2012-05-01

A novel N-allyl-4-amino-substituted 1,8-naphthalimide dye, containing thiourea functional group with intense yellow-green fluorescence was successfully synthesized. Copolymerization was done with styrene. The photophysical characteristics of dye and its copolymer in solution and solid film were investigated in the presence of halide ions. The results reveal that the fluorescence emissions of the monomer dye and also its polymer were 'switched off' in the presence of fluoride ions. The dye showed spectral shifts and intensity changes in the presence of more fluoride ions which lead to detect certain fluoride concentrations of 10-150 mM at visible wavelengths. By adding the fluoride ions, green-yellow to purple color changes occurs and the green fluorescence emission quenches, all of which easily observed by naked eyes. These phenomena are essential for producing a dual responsive chemosensor for fluoride ions. The polymeric sensor, in the film state exhibited a fast response to the fluoride ions. Copyright © 2012 Elsevier B.V. All rights reserved.

Synthesis, biological evaluation and molecular docking of N-phenyl thiosemicarbazones as urease inhibitors.

PubMed

Hameed, Abdul; Khan, Khalid Mohammed; Zehra, Syeda Tazeen; Ahmed, Ramasa; Shafiq, Zahid; Bakht, Syeda Mahwish; Yaqub, Muhammad; Hussain, Mazhar; de la Vega de León, Antonio; Furtmann, Norbert; Bajorath, Jürgen; Shad, Hazoor Ahmad; Tahir, Muhammad Nawaz; Iqbal, Jamshed

2015-08-01

Urease is an important enzyme which breaks urea into ammonia and carbon dioxide during metabolic processes. However, an elevated activity of urease causes various complications of clinical importance. The inhibition of urease activity with small molecules as inhibitors is an effective strategy for therapeutic intervention. Herein, we have synthesized a series of 19 benzofurane linked N-phenyl semithiocarbazones (3a-3s). All the compounds were screened for enzyme inhibitor activity against Jack bean urease. The synthesized N-phenyl thiosemicarbazones had varying activity levels with IC50 values between 0.077 ± 0.001 and 24.04 ± 0.14 μM compared to standard inhibitor, thiourea (IC50 = 21 ± 0.11 μM). The activities of these compounds may be due to their close resemblance of thiourea. A docking study with Jack bean urease (PDB ID: 4H9M) revealed possible binding modes of N-phenyl thiosemicarbazones. Copyright © 2015 Elsevier Inc. All rights reserved.

Synthesis, Characterization and the Corrosion Inhibition Study of Two Schiff Base Ligands Derived From Urea and Thiourea and Their Complexes with Cu(II) and Hg(II) Ions

NASA Astrophysics Data System (ADS)

Alwan, Wasan Mohammed

2018-05-01

The research includes synthesis of [L1] and [L2] Schiff base ligands by the reaction of vanillin with urea and thiourea respectively in 2:1 mol ratio. The two ligands were reacted with CuII ion in 1:2 mol ratio and HgII ion in 1:1 mol ratio. The prepared compounds have been identified by FTIR, U.V-Vis, 1H-NMR (L1, L2 and HgII complex) spectroscopies, microelemental analysis (C.H.N.S), magnetic susceptibility measurements, atomic absorption, chloride content along with conductivity and melting point measurements. According to applied characterization methods, the proposed general formulas of CuII and HgII complexes were [Cu2LnCl4] and [HgLnCl]Cl, respectively, (where n = 1, 2). The ability of corrosion inhibition with two ligands and their cupper complexes has been studied in diluted hydrochloric acid media.

Synthesis of 4-thiazolidinone analogs as potent in vitro anti-urease agents.

PubMed

Rahim, Fazal; Zaman, Khalid; Ullah, Hayat; Taha, Muhammad; Wadood, Abdul; Javed, Muhammad Tariq; Rehman, Wajid; Ashraf, Muhammad; Uddin, Reaz; Uddin, Imad; Asghar, Humna; Khan, Aftab Ahmad; Khan, Khalid M

2015-12-01

4-Thiazolidinone analogs 1-20 were synthesized, characterized by (1)H NMR and EI-MS and investigated for urease inhibitory activity. All twenty (20) analogs exhibited varied degree of urease inhibitory potential with IC50 values 1.73-69.65μM, if compared with standard thiourea having IC50 value of 21.25±0.15μM. Among the series, eight derivatives 3, 6, 8, 10, 15, 17, 19, and 20 showed outstanding urease inhibitory potential with IC50 values of 9.34±0.02, 14.62±0.03, 8.43±0.01, 7.3±0.04, 2.31±0.002, 5.75±0.003, 8.81±0.005, and 1.73±0.001μM, respectively, which is better than the standard thiourea. The remaining analogs showed good to excellent urease inhibition. The binding interactions of these compounds were confirmed through molecular docking studies. Copyright © 2015 Elsevier Inc. All rights reserved.

Influence of Urea, Hydroxyurea, and Thiourea on Meloidogyne javanica and Infected Excised Tomato Roots in Culture

PubMed Central

Glazer, I.; Orion, D.

1984-01-01

Urea (U), hydroxyurea (HU), and thiourea (TU), in various concentrations, were added to chemically defined plant tissue culture medium on which Meloidogyne javanica was reared on excised tomato roots. Concentrations as low as 3 ppm HU or 12 ppm TU inhibited nematode maturation by 70-90% 4 weeks after inoculation, and the coenocytes in the parasitized tissue were poorly developed. Gall weight was also inhibited by 50% in cultures treated with 3 and 6 ppm HU. However, exposing juveniles of M. javanica and Tylenchulus semipenetrans or juveniles and adults of Pratylenchus thornei to increasing concentrations of HU or TU, up to 100 ppm, was not lethal. These two urea derivatives still inhibited nematode maturation when the infected region of the root was not in direct contact with the chemicals. Therefore, we suggest that these urea derivatives inhibit nematode development by affecting the plant metabolism essential to coenocyte formation, an occurrence similar to the hypersensitive reaction in a naturally resistant plant. PMID:19295888

Cyclization Reaction of Acyl Thiourea Chitosan: Enhanced Antifungal Properties via Structural Optimization.

PubMed

Qin, Yukun; Liu, Weixiang; Xing, Ronge; Liu, Song; Li, Kecheng; Li, Pengcheng

2018-03-06

In this study, 3-methyl-1,2,4-triazolyl chitosan (MTACS) and 3-chloromethyl-1,2,4-triazolyl chitosan (CMTACS) were prepared via cyclization of acyl thiourea chitosan (TUCS). Their structures were confirmed by FT-IR, ¹H-NMR, elemental analysis, DSC, XRD, and SEM. The conformations were predicted using the Gaussian 09 program. Additionally, the antifungal properties of MTACS and CMTACS against Stemphylium solani weber ( S. solani ), Alternaria porri ( A. porri ), and Gloeosporium theae-sinensis ( G. theae-sinensis ) were assayed in vitro and ranged from 250 μg/mL to 1000 μg/mL. The results showed that MTACS and CMTACS exhibited enhanced inhibitory effect on the selected fungi compared to the original chitosan and TUCS. In particular, they displayed better antifungal activities against A. porri and G. theae-sinensis than that of the positive control, Triadimefon. The findings described here may lead to them being used as antifungal agents for crop protection.

Uptake and metabolism of sulphated steroids by the blood-brain barrier in the adult male rat.

PubMed

Qaiser, M Zeeshan; Dolman, Diana E M; Begley, David J; Abbott, N Joan; Cazacu-Davidescu, Mihaela; Corol, Delia I; Fry, Jonathan P

2017-09-01

Little is known about the origin of the neuroactive steroids dehydroepiandrosterone sulphate (DHEAS) and pregnenolone sulphate (PregS) in the brain or of their subsequent metabolism. Using rat brain perfusion in situ, we have found 3 H-PregS to enter more rapidly than 3 H-DHEAS and both to undergo extensive (> 50%) desulphation within 0.5 min of uptake. Enzyme activity for the steroid sulphatase catalysing this deconjugation was enriched in the capillary fraction of the blood-brain barrier and its mRNA expressed in cultures of rat brain endothelial cells and astrocytes. Although permeability measurements suggested a net efflux, addition of the efflux inhibitors GF120918 and/or MK571 to the perfusate reduced rather than enhanced the uptake of 3 H-DHEAS and 3 H-PregS; a further reduction was seen upon the addition of unlabelled steroid sulphate, suggesting a saturable uptake transporter. Analysis of brain fractions after 0.5 min perfusion with the 3 H-steroid sulphates showed no further metabolism of PregS beyond the liberation of free steroid pregnenolone. By contrast, DHEAS underwent 17-hydroxylation to form androstenediol in both the steroid sulphate and the free steroid fractions, with some additional formation of androstenedione in the latter. Our results indicate a gain of free steroid from circulating steroid sulphates as hormone precursors at the blood-brain barrier, with implications for ageing, neurogenesis, neuronal survival, learning and memory. © 2017 International Society for Neurochemistry.

Use of hydraulic binders for reducing sulphate leaching: application to gypsiferous soil sampled in Ile-de-France region (France).

PubMed

Trincal, Vincent; Thiéry, Vincent; Mamindy-Pajany, Yannick; Hillier, Stephen

2018-06-01

Polluted soils are a serious environmental risk worldwide and consist of millions of tons of mineral waste to be treated. In order to ensure their sustainable management, various remediation options must be considered. Hydraulic binder treatment is one option that may allow a stabilisation of pollution and thus offer a valorisation as secondary raw materials rather than considering them as waste. In this study, we focused on sulphate-polluted soil and tested the effectiveness of several experimental hydraulic binders. The aim was to transform gypsum into ettringite, a much less soluble sulphate, and therefore to restrict the potential for sulphate pollutant release. The environmental assessment of five formulations using hydraulic binders was compared to the gypsiferous soil before treatment (contaminated in sulphate). The approach was to combine leaching tests with mineralogical quantifications using among others thermogravimetric and XRD methods. In the original soil and in the five formulations, leaching tests indicate sulphate release above environmental standards. However, hydraulic binders promote ettringite formation, as well as a gypsum content reduction as observed by SEM. The stabilisation of sulphates is, however, insufficient, probably as a result of the very high content of gypsum in the unusual soil used. The mineralogical reactions highlighted during the hydration of hydraulic binders are promising; they could pave the way for the development of new industrial mixtures that would have a positive environmental impact by allowing reuse of soils that would otherwise be classified as waste.

Intralesional bleomycin and sodium tetradecyl sulphate for haemangiomas and lymphangiomas.

PubMed

Harjai, Man Mohan; Jha, Manvendu

2012-01-01

To compare the efficacy of intralesional bleomycin and sodium tetradecyl sulphate in treatment of haemangiomas and lymphangiomas. Between July 2007 and May 2009, 120 patients, sixty each of peripheral haemangiomas and lymphangiomas, were administered intralesional injection of bleomycin in a dose of 0.5-1 U/kg in children less than one year of age and 1 to 15 units in children more than one year of age and 1 to 3 ml of 2% sodium tetradecyl sulphate, depending on the size of the lesion at intervals of 14 days. Patients more than 20 years of age and those with diffuse or visceral lesions were excluded from the study. Complete resolution occurred in 16 patients (53%) of haemangiomas and 14 patients (47%) of lymphangiomas treated with bleomycin, while the results were 12 patients (40%) and 10 patients (33%), respectively, in sodium tetradecyl sulphate group. The satisfactory resolution (resolution more than 50%) occurred in eight patients (27%) of haemangiomas and lymphangiomas groups treated with bleomycin, while the results were six patients (20%) and eight patients (27%), respectively, in sodium tetradecyl sulphate group. Poor response rate was observed in six patients (20%) of haemangiomas and eight patients (27%) of lymphangiomas of bleomycin group and 12 patients (40%) of haemangiomas and lymphangiomas in sodium tetradecyl sulphate group. No pulmonary fibrosis or other serious side effects were found. Intralesional bleomycin and sodium tetradecyl sulphate are effective sclerosants in peripheral haemangiomas and lymphangiomas, but bleomycin was found to be more efficacious.

ACUTE EXPOSURE TO TRIS (2-CHLOROETHYL) PHOSPHATE HIPPOCAMPAL NEURONAL LOSS AND IMPAIRS LEARNING IN RATS

EPA Science Inventory

Adult female, Fischer 344 rats were exposed to 275 mg/kg of tris(2- chloroethyl)phosphate (TRCP) by gavage. RCP produced consistent signs of convulsive activity within 60-90 minutes after dosing and extensive loss of CA1 hippocampal pyramidal cells when examined 7 days after dosi...

A New Approach toward Cyanotype Photography Using Tris-(Oxalato)ferrate(III): An Integrated Experiment

ERIC Educational Resources Information Center

Fiorito, Pablo Alejandro; Polo, Andre´ Sarto

2015-01-01

This work presents an approach that integrates the preparation of a coordination compound, potassium tris- (oxalato)ferrate(III), with its photochemical behavior and provides a possible application, the printing of a photograph using the cyanotype technique. Through this experiment, students can be taught several concepts that occur in a…

Isolation of Protective Antigen from Anthrax Toxin by Preparative Isotachophoresis

DTIC Science & Technology

1982-06-14

caosule of polymerized D-olutamic acid which inhibits phago- cytosis and allows the bacillus to establish an infectious focus and elaborate a tripartite...The terminating buffer Tris-c- aminocaproate (Tris-EACA), pH 8.4, was used in the upper electrode (cathode) chamber and in the column. fteen ml of toxin

Exciplex emission and decay of co-deposited 4,4',4″-tris[3-methylphenyl(phenyl)amino]triphenylamine:tris-[3-(3-pyridyl)mesityl]borane organic light-emitting devices with different electron transporting layer thicknesses

NASA Astrophysics Data System (ADS)

Huang, Qingyu; Zhao, Suling; Xu, Zheng; Fan, Xing; Shen, Chongyu; Yang, Qianqian

2014-04-01

Highly efficient fluorescence organic light-emitting diodes (OLEDs) based on the mixed 4,4',4″-tris[3-methylphenyl(phenyl)amino]triphenylamine:tris-[3-(3-pyridyl)mesityl]borane (1:1) system are reported. The electroluminescence due to the exciplex emission is red shifted when the thickness of the electron-transporting layer increases. The prepared OLEDs achieve a low turn-on voltage of 2.1 V, a high current efficiency of 36.79 cd/A, and a very high luminescence of 17 100 cd/m2, as well as a low efficiency roll-off. The current efficiency of the optimized OLED is maintained at more than 28.33 cd/A up to 10 000 cd m-2. The detailed recombination mechanism of the prepared OLEDs is investigated by the transient electroluminescence method. It is concluded that there are no contributions from trapped charges and annihilations of triplet-triplet excitons to the detected electroluminescence.

Flash Inactivation of Oxygen Evolution

PubMed Central

Frasch, Wayne D.; Cheniae, George M.

1980-01-01

Brief saturating light flashes were used to probe the mechanism of inactivation of O2 evolution by Tris in chloroplasts. Maximum inactivation with a single flash and an oscillation with period of four on subsequent flashes was observed. Analyses of the oscillations suggested that only the charge-collecting O2-evolving catalyst of photosystem II (S2-state) was a target of inactivation by Tris. This conclusion was supported by the following observations: (a) hydroxylamine preequilibration caused a three-flash delay in the inactivation pattern; (b) the lifetimes of the Tris-inactivable and S2-states were similar; and (c) reagents accelerating S2 deactivation decreased the lifetime of the inactivable state. Inactivation proved to be moderated by F, the precursor of Signal IIs, as shown by a one flash delay with chloroplasts having high abundance of F. Evidence was obtained for cooperativity effects in inactivation and NH3 was shown to be a competitive inhibitor of the Tris-induced inactivation. S2-dependent inactivation was inhibited by glutaraldehyde fixation of chloroplasts, possibly suggesting that inactivation proceeds via conformational changes of the S2-state. PMID:16661270

Regional distribution of halogenated organophosphate flame retardants in seawater samples from three coastal cities in China.

PubMed

Hu, Mengyang; Li, Jun; Zhang, Beibei; Cui, Qinglan; Wei, Si; Yu, Hongxia

2014-09-15

Thirteen samples of seawater were collected from Yellow Sea and East China Sea near Qingdao, Lianyungang, and Xiamen, China. They were analyzed for halogenated organophosphorus flame retardants (OPFRs). The compounds selected for detection were Tris(2-chloroethyl) phosphate (TCEP), Tris(2-chloroisopropyl) phosphate (TCPP), Tris (1,3-dichloro-2-propyl) phosphate (TDCPP), and Tris(2,3-dibromopropyl) phosphate (TDBPP). The total concentrations ranged from 91.87 to 1392 ng/L and the mean concentrations of these four chemicals were 134.44, 84.12, 109.28, and 96.70 ng/L, respectively. TCEP exhibited the highest concentrations, although concentrations of TCPP and TDCPP were also fairly high in Lianyungang and Xiamen. Generally, Lianyungang was the most heavily polluted district, with very high concentrations of TCEP at LYG-2 (550.54 ng/L) and LYG-4 (617.92 ng/L). The main sources of halogenated OPFRs were municipal and industrial effluents of wastewater treatment plants in the nearby economic and industrial zones. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ground and flight test results of a total main rotor isolation system

NASA Technical Reports Server (NTRS)

Halwes, Dennis R.

1987-01-01

A six degree-of-freedom (DOF) isolation system using six LIVE units has been installed under an Army/NASA contract on a Bell 206LM helicopter. This system has been named the Total Rotor Isolation System, or TRIS. To determine the effectiveness of TRIS in reducing helicopter vibration, a flight verification study was conducted at Bell's Flight Research Center in Arlington, Texas. The flight test data indicate that the 4/rev vibration level at the pilot's seat were suppressed below the 0.04g level throughout the transition envelope. Flight tests indicate over 95% suppression of vibration level from the rotor hub to the pilot's seat. The TRIS installation was designed with a decoupled control system and has shown a significant improvement in aircraft flying qualities, such that it permitted the trimmed aircraft to be flown hands-off for a significant period of time, over 90 seconds. The TRIS flight test program has demonstrated a system that greatly reduces vibration levels of a current-generation helicopter, while significantly improving the flying qualities to a point where stability augmentation is no longer a requirement.

Highly efficient quenching of tris(2,2'-bipyridyl)ruthenium(II) electrochemiluminescence by ozone using formaldehyde, methylglyoxal, and glyoxalate as co-reactants and its application to ozone sensing.

PubMed

Gao, Ying; Liu, Xiaoyun; Qi, Wenjing; Gao, Wenyue; Li, Yunhui; Xu, Guobao

2015-06-21

Most electrochemiluminescence (ECL) systems require high concentrations of quencher to totally quench ECL. In this study, we found that ozone can quench tris(2,2'-bipyridyl)ruthenium(II) ECL using formaldehyde, methylglyoxal, or glyoxalate as co-reactants at a glassy carbon electrode with remarkable efficiencies even when the concentration of ozone is merely 0.25% of that of the co-reactant. The strongest quenching is observed with the tris(2,2'-bipyridyl)ruthenium(II)/formaldehyde ECL system. The tris(2,2'-bipyridyl)ruthenium(II)/formaldehyde ECL intensities decrease linearly with the ozone concentration over the range of 0.025-25 μM (r = 0.9947) with a limit of detection of 8 nM. The method is more sensitive and faster than most methods. It shows high selectivity in the presence of other ROS or oxidants and some metal ions, such as H2O2, ClO(-), Mg(2+), Ni(2+), etc. The method exhibits high recoveries for the detection of ozone in a ventilated photocopy room.

Evaluation of the stability of uranyl peroxo-carbonato complex ions in carbonate media at different temperatures.

PubMed

Kim, Kwang-Wook; Lee, Keun-Young; Chung, Dong-Yong; Lee, Eil-Hee; Moon, Jei-Kwon; Shin, Dong-Woo

2012-09-30

This work studied the stability of peroxide in uranyl peroxo carbonato complex ions in a carbonate solution with hydrogen peroxide using absorption and Raman spectroscopies, and evaluated the temperature dependence of the decomposition characteristics of uranyl peroxo carbonato complex ions in the solution. The uranyl peroxo carbonato complex ions self-decomposed more rapidly into uranyl tris-carbonato complex ions in higher temperature carbonate solutions. The concentration of peroxide in the solution without free hydrogen peroxide represents the concentration of uranyl peroxo carbonato complex ions in a mixture of uranyl peroxo carbonato complex and uranyl tris-carbonato complex ions. The self-decomposition of the uranyl peroxo carbonato complex ions was a first order reaction, and its activation energy was evaluated to be 7.144×10(3) J mol(-1). The precipitation of sodium uranium oxide hydroxide occurred when the amount of uranyl tris-carbonato complex ions generated from the decomposition of the uranyl peroxo carbonato complex ions exceeded the solubility of uranyl tris-carbonato ions in the solution at the solution temperature. Copyright © 2012 Elsevier B.V. All rights reserved.

Dialysis buffer with different ionic strength affects the antigenicity of cultured nervous necrosis virus (NNV) suspensions.

PubMed

Gye, Hyun Jung; Nishizawa, Toyohiko

2016-09-02

Nervous necrosis virus (NNV) belongs to the genus Betanodavirus (Nodaviridae). It is highly pathogenic to various marine fishes. Here, we investigated the antigenicity changes of cultured NNV suspensions during 14days of dialyses using a dialysis tube at 1.4×10(4) molecular weight cut off (MWCO) in three different buffers (Dulbecco's phosphate buffered saline (D-PBS), 15mM Tris-HCl (pH 8.0), and deionized water (DIW)). Total NNV antigen titers of cultured NNV suspension varied depending on different dialysis buffers. For example, total NNV antigen titer during D-PBS dialysis was increased once but then decreased. During Tris-HCl dialysis, it was relatively stable. During dialysis in DIW, total NNV antigen titer was increased gradually. These antigenicity changes in NNV suspension might be due to changes in the aggregation state of NNV particles and/or coat proteins (CPs). ELISA values of NNV suspension changed due to changing aggregates state of NNV antigens. NNV particles in suspension were aggregated at a certain level. These aggregates were progressive after D-PBS dialysis, but regressive after Tris-HCl dialysis. The purified NNV particles self-aggregated after dialysis in D-PBS or in Tris-HCl containing 600mM NaCl, but not after dialysis in Tris-HCl or DIW. Quantitative analysis is merited to determine NNV antigens in the highly purified NNV particles suspended in buffer at low salt condition. Copyright © 2016 Elsevier B.V. All rights reserved.

Recovery and cryopreservation of epididymal sperm from agouti (Dasiprocta aguti) using powdered coconut water (ACP-109c) and Tris extenders.

PubMed

Silva, M A; Peixoto, G C X; Santos, E A A; Castelo, T S; Oliveira, M F; Silva, A R

2011-10-01

The objective was to compare the use of powdered coconut water (ACP-109c; ACP Biotecnologia, Fortaleza, CE, Brazil) and Tris extenders for recovery and cryopreservation of epididymal sperm from agouti. The caudae epididymus and proximal ductus deferens from 10 sexually mature agoutis were subjected to retrograde washing using ACP-109c (ACP Biotecnologia) or Tris. Epididymal sperm were evaluated for motility, vigor, sperm viability, membrane integrity, and morphology. Samples were centrifuged, and extended in the same diluents plus egg yolk (20%) and glycerol (6%), frozen in liquid nitrogen, and subsequently thawed at 37°C for 1 min, followed by re-evaluation of sperm characteristics. The two extenders were similarly efficient for epididymal recovery, with regard to the number and quality of sperm recovered. However, for both extenders, sperm quality decreased (P < 0.05) after centrifugation and dilution. After sperm cryopreservation and thawing, there were (mean ± SEM) 26.5 ± 2.6% motile sperm with 2.6 ± 0.2 vigor in the ACP-109c (ACP Biotecnologia) group, which was significantly better than 9.7 ± 2.6% motile sperm with 1.2 ± 0.3 vigor in Tris. In conclusion, agouti epididymal sperm were successfully recovered using either ACP-109c (ACP Biotecnologia) or Tris extenders; however, ACP-109c (ACP Biotecnologia) was a significantly better extender for processing and cryopreserving these sperm. Copyright © 2011 Elsevier Inc. All rights reserved.

Crystal structure of salt-tolerant glutaminase from Micrococcus luteus K-3 in the presence and absence of its product L-glutamate and its activator Tris.

PubMed

Yoshimune, Kazuaki; Shirakihara, Yasuo; Wakayama, Mamoru; Yumoto, Isao

2010-02-01

Glutaminase from Micrococcus luteus K-3 [Micrococcus glutaminase (Mglu); 456 amino acid residues (aa); 48 kDa] is a salt-tolerant enzyme. Our previous study determined the structure of its major 42-kDa fragment. Here, using new crystallization conditions, we determined the structures of the intact enzyme in the presence and absence of its product L-glutamate and its activator Tris, which activates the enzyme by sixfold. With the exception of a 'lid' part (26-29 aa) and a few other short stretches, the structures were all very similar over the entire polypeptide chain. However, the presence of the ligands significantly reduced the length of the disordered regions: 41 aa in the unliganded structure (N), 21 aa for L-glutamate (G), 8 aa for Tris (T) and 6 aa for both L-glutamate and Tris (TG). L-glutamate was identified in both the G and TG structures, whereas Tris was only identified in the TG structure. Comparison of the glutamate-binding site between Mglu and salt-labile glutaminase (YbgJ) from Bacillus subtilis showed significantly smaller structural changes of the protein part in Mglu. A comparison of the substrate-binding pocket of Mglu, which is highly specific for L-glutamine, with that of Erwinia carotovora asparaginase, which has substrates other than L-glutamine, shows that Mglu has a larger substrate-binding pocket that prevents the binding of L-asparagine with proper interactions.

Synthesis, cytotoxicity, and hydroxyapatite formation in 27-Tris-SBF for sol-gel based CaO-P2O5-SiO2-B2O3-ZnO bioactive glasses

NASA Astrophysics Data System (ADS)

Kaur, Gurbinder; Pickrell, G.; Kimsawatde, G.; Homa, D.; Allbee, H. A.; Sriranganathan, N.

2014-03-01

CaO-P2O5-SiO2-B2O3-ZnO bioactive glasses were prepared via an optimized sol-gel method. The current investigation was focused on producing novel zinc based calcium phosphoborosilicate glasses and to evaluate their mechanical, rheological, and biocompatible properties. The morphology and composition of these glasses were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The particle size, mechanical and flexural strength was also determined. Furthermore, the zeta potential of all the glasses were determined to estimate their flocculation tendency. The thermal analysis and weight loss measurements were carried out using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) respectively. For assessing the in-vitro bioactive character of synthesized glasses, the ability for apatite formation on their surface upon their immersion in simulated body fluid (SBF) was checked using SEM and pH measurements. MTS assay cytotoxicity assay and live-dead cell viability test were conducted on J774A.1 cells murine macrophage cells for different glass concentrations.

Luminescence-Functionalized Metal-Organic Frameworks Based on a Ruthenium(II) Complex: A Signal Amplification Strategy for Electrogenerated Chemiluminescence Immunosensors.

PubMed

Xiong, Cheng-Yi; Wang, Hai-Jun; Liang, Wen-Bin; Yuan, Ya-Li; Yuan, Ruo; Chai, Ya-Qin

2015-06-26

Novel luminescence-functionalized metal-organic frameworks (MOFs) with superior electrogenerated chemiluminescence (ECL) properties were synthesized based on zinc ions as the central ions and tris(4,4'-dicarboxylicacid-2,2'-bipyridyl)ruthenium(II) dichloride ([Ru(dcbpy)3](2+)) as the ligands. For potential applications, the synthesized MOFs were used to fabricate a "signal-on" ECL immunosensor for the detection of N-terminal pro-B-type natriuretic peptide (NT-proBNP). As expected, enhanced ECL signals were obtained through a simple fabrication strategy because luminescence-functionalized MOFs not only effectively increased the loading of [Ru(dcbpy)3](2+), but also served as a loading platform in the ECL immunosensor. Furthermore, the proposed ECL immunosensor had a wide linear range from 5 pg mL(-1) to 25 ng mL(-1) and a relatively low detection limit of 1.67 pg mL(-1) (signal/noise=3). The results indicated that luminescence-functionalized MOFs provided a novel amplification strategy in the construction of ECL immunosensors and might have great prospects for application in bioanalysis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, cytotoxicity, and hydroxyapatite formation in 27-Tris-SBF for sol-gel based CaO-P2O5-SiO2-B2O3-ZnO bioactive glasses.

PubMed

Kaur, Gurbinder; Pickrell, G; Kimsawatde, G; Homa, D; Allbee, H A; Sriranganathan, N

2014-03-18

CaO-P2O5-SiO2-B2O3-ZnO bioactive glasses were prepared via an optimized sol-gel method. The current investigation was focused on producing novel zinc based calcium phosphoborosilicate glasses and to evaluate their mechanical, rheological, and biocompatible properties. The morphology and composition of these glasses were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The particle size, mechanical and flexural strength was also determined. Furthermore, the zeta potential of all the glasses were determined to estimate their flocculation tendency. The thermal analysis and weight loss measurements were carried out using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) respectively. For assessing the in-vitro bioactive character of synthesized glasses, the ability for apatite formation on their surface upon their immersion in simulated body fluid (SBF) was checked using SEM and pH measurements. MTS assay cytotoxicity assay and live-dead cell viability test were conducted on J774A.1 cells murine macrophage cells for different glass concentrations.

Synthesis, cytotoxicity, and hydroxyapatite formation in 27-Tris-SBF for sol-gel based CaO-P2O5-SiO2-B2O3-ZnO bioactive glasses

PubMed Central

Kaur, Gurbinder; Pickrell, G.; Kimsawatde, G.; Homa, D.; Allbee, H. A.; Sriranganathan, N.

2014-01-01

CaO-P2O5-SiO2-B2O3-ZnO bioactive glasses were prepared via an optimized sol–gel method. The current investigation was focused on producing novel zinc based calcium phosphoborosilicate glasses and to evaluate their mechanical, rheological, and biocompatible properties. The morphology and composition of these glasses were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The particle size, mechanical and flexural strength was also determined. Furthermore, the zeta potential of all the glasses were determined to estimate their flocculation tendency. The thermal analysis and weight loss measurements were carried out using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) respectively. For assessing the in-vitro bioactive character of synthesized glasses, the ability for apatite formation on their surface upon their immersion in simulated body fluid (SBF) was checked using SEM and pH measurements. MTS assay cytotoxicity assay and live-dead cell viability test were conducted on J774A.1 cells murine macrophage cells for different glass concentrations. PMID:24637634

Can activated sludge treatments and advanced oxidation processes remove organophosphorus flame retardants?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cristale, Joyce; Ramos, Dayana D.; Dantas, Renato F.

2016-01-15

This study aims to determine the occurrence of 10 OPFRs (including chlorinated, nonchlorinated alkyl and aryl compounds) in influent, effluent wastewaters and partitioning into sludge of 5 wastewater treatment plants (WWTP) in Catalonia (Spain). All target OPFRs were detected in the WWTPs influents, and the total concentration ranged from 3.67 µg L{sup −1} to 150 µg L{sup −1}. During activated sludge treatment, most OPFRs were accumulated in the sludge at concentrations from 35.3 to 9980 ng g{sup −1} dw. Chlorinated compounds tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP) and tris(2,3-dichloropropyl) phosphate (TDCPP) were not removed by the conventional activated sludge treatmentmore » and they were released by the effluents at approximately the same inlet concentration. On the contrary, aryl compounds tris(methylphenyl) phosphate (TMPP) and 2-ethylhexyl diphenyl phosphate (EHDP) together with alkyl tris(2-ethylhexyl) phosphate (TEHP) were not detected in any of the effluents. Advanced oxidation processes (UV/H{sub 2}O{sub 2} and O{sub 3}) were applied to investigate the degradability of recalcitrant OPFRs in WWTP effluents. Those detected in the effluent sample (TCEP, TCIPP, TDCPP, tributyl phosphate (TNBP), tri-iso-butyl phosphate (TIBP) and tris(2-butoxyethyl) phosphate (TBOEP)) had very low direct UV-C photolysis rates. TBOEP, TNBP and TIBP were degraded by UV/H{sub 2}O{sub 2} and O{sub 3}. Chlorinated compounds TCEP, TDCPP and TCIPP were the most recalcitrant OPFR to the advanced oxidation processes applied. The study provides information on the partitioning and degradability pathways of OPFR within conventional activated sludge WWTPs. - Highlights: • OPFRs were detected in wastewater and sludge of all studied WWTPs. • Alkyl and chloroalkyl phosphates were present in secondary treatment effluents. • TBOEP, TNBP and TIBP were degraded by UV/H{sub 2}O{sub 2} and O{sub 3} treatment. • TCEP, TCIPP and TDCPP were resistant to both secondary and tertiary treatment.« less

Regional and temporal variability of the isotope composition (O, S) of atmospheric sulphate in the region of Freiberg, Germany, and consequences for dissolved sulphate in groundwater and river water.

PubMed

Tichomirowa, Marion; Heidel, Claudia

2012-01-01

The isotope composition of dissolved sulphate and strontium in atmospheric deposition, groundwater, mine water and river water in the region of Freiberg was investigated to better understand the fate of these components in the regional and global water cycle. Most of the isotope variations of dissolved sulphates in atmospheric deposition from three locations sampled bi- or tri-monthly can be explained by fractionation processes leading to lower [Formula: see text] (of about 2-3‰) and higher [Formula: see text] (of about 8-10‰) values in summer compared with the winter period. These samples showed a negative correlation between [Formula: see text] and [Formula: see text] values and a weak positive correlation between [Formula: see text] and [Formula: see text] values. They reflect the sulphate formed by aqueous oxidation from long-range transport in clouds. However, these isotope variations were superimposed by changes of the dominating atmospheric sulphate source. At two of the sampling points, large variations of mean annual [Formula: see text] values from atmospheric bulk deposition were recorded. From 2008 to 2009, the mean annual [Formula: see text] value increased by about 5‰; and decreased by about 4‰ from 2009 to 2010. A change in the dominating sulphate source or oxidation pathways of SO(2) in the atmosphere is proposed to cause these shifts. No changes were found in corresponding [Formula: see text] values. Groundwater, river water and some mine waters (where groundwater was the dominating sulphate source) also showed temporal shifts in their [Formula: see text] values corresponding to those of bulk atmospheric deposition, albeit to a lower degree. The mean transit time of atmospheric sulphur through the soil into the groundwater and river water was less than a year and therefore much shorter than previously suggested. Mining activities of about 800 years in the Freiberg region may have led to large subsurface areas with an enhanced groundwater flow along fractures and mined-refilled ore lodes which may shorten transit times of sulphate from precipitation through groundwater into river water.

Magnesium sulphate at 30 to 34 weeks' gestational age: neuroprotection trial (MAGENTA)--study protocol.

PubMed

Crowther, Caroline A; Middleton, Philippa F; Wilkinson, Dominic; Ashwood, Pat; Haslam, Ross

2013-04-09

Magnesium sulphate is currently recommended for neuroprotection of preterm infants for women at risk of preterm birth at less than 30 weeks' gestation, based on high quality evidence of benefit. However there remains uncertainty as to whether these benefits apply at higher gestational ages.The aim of this randomised controlled trial is to assess whether giving magnesium sulphate compared with placebo to women immediately prior to preterm birth between 30 and 34 weeks' gestation reduces the risk of death or cerebral palsy in their children at two years' corrected age. Randomised, multicentre, placebo controlled trial. Women, giving informed consent, at risk of preterm birth between 30 to 34 weeks' gestation, where birth is planned or definitely expected within 24 hours, with a singleton or twin pregnancy and no contraindications to the use of magnesium sulphate.Trial entry & randomisation: Eligible women will be randomly allocated to receive either magnesium sulphate or placebo.Treatment groups: Women in the magnesium sulphate group will be administered 50 ml of a 100 ml infusion bag containing 8 g magnesium sulphate heptahydrate [16 mmol magnesium ions]. Women in the placebo group will be administered 50 ml of a 100 ml infusion bag containing isotonic sodium chloride solution (0.9%). Both treatments will be administered through a dedicated IV infusion line over 30 minutes.Primary study outcome: Death or cerebral palsy measured in children at two years' corrected age. 1676 children are required to detect a decrease in the combined outcome of death or cerebral palsy, from 9.6% with placebo to 5.4% with magnesium sulphate (two-sided alpha 0.05, 80% power, 5% loss to follow up, design effect 1.2). Given the magnitude of the protective effect in the systematic review, the ongoing uncertainty about benefits at later gestational ages, the serious health and cost consequences of cerebral palsy for the child, family and society, a trial of magnesium sulphate for women at risk of preterm birth between 30 to 34 weeks' gestation is both important and relevant for clinical practice globally. Australian New Zealand Clinical Trials Registry - ACTRN12611000491965.

Voltammetry at the Thin-Film Mercury Electrode (TFME).

ERIC Educational Resources Information Center

Pomeroy, R. S.; And Others

1989-01-01

Reviewed is the use of the Thin-Film Mercury Electrode for anodic stripping voltammetry, simple voltammetry of solution cations and cathodic stripping voltammetry for the determination of an environmentally important molecule, thiourea. The construction of a simple potentiostat and applications for student laboratory courses are included. (CW)

Neutralisation of an acidic pit lake by alkaline waste products.

PubMed

Allard, Bert; Bäckström, Mattias; Karlsson, Stefan; Grawunder, Anja

2014-01-01

A former open pit where black shale (alum shale) was excavated during 1942-1965 has been water filled since 1966. The water chemistry was dominated by calcium and sulphate and had a pH of 3.2-3.4 until 1997-1998, when pH was gradually increasing. This was due to the intrusion of leachates from alkaline cement waste deposited close to the lake. A stable pH of around 7.5 was obtained after 6-7 years. The chemistry of the pit lake has changed due to the neutralisation. Concentrations of some dissolved metals, notably zinc and nickel, have gone down, as a result of adsorption/co-precipitation on solid phases (most likely iron and aluminium hydroxides), while other metals, notably uranium and molybdenum, are present at elevated levels. Uranium concentration is reaching a minimum of around pH 6.5 and is increasing at higher pH, which may indicate a formation of neutral and anionic uranyl carbonate species at high pH (and total carbonate levels around 1 mM). Weathering of the water-exposed shale is still in progress.

Iron from nanocompounds containing iron and zinc is highly bioavailable in rats without tissue accumulation

NASA Astrophysics Data System (ADS)

Hilty, Florentine M.; Arnold, Myrtha; Hilbe, Monika; Teleki, Alexandra; Knijnenburg, Jesper T. N.; Ehrensperger, Felix; Hurrell, Richard F.; Pratsinis, Sotiris E.; Langhans, Wolfgang; Zimmermann, Michael B.

2010-05-01

Effective iron fortification of foods is difficult, because water-soluble compounds that are well absorbed, such as ferrous sulphate (FeSO4), often cause unacceptable changes in the colour or taste of foods. Poorly water-soluble compounds, on the other hand, cause fewer sensory changes, but are not well absorbed. Here, we show that poorly water-soluble nanosized Fe and Fe/Zn compounds (specific surface area ~190 m2 g-1) made by scalable flame aerosol technology have in vivo iron bioavailability in rats comparable to FeSO4 and cause less colour change in reactive food matrices than conventional iron fortificants. The addition of Zn to FePO4 and Mg to Fe/Zn oxide increases Fe absorption from the compounds, and doping with Mg also improves their colour. After feeding rats with nanostructured iron-containing compounds, no stainable Fe was detected in their gut wall, gut-associated lymphatics or other tissues, suggesting no adverse effects. Nanosizing of poorly water-soluble Fe compounds sharply increases their absorption and nutritional value.

Glyceraldehyde-3-phosphate dehydrogenase from Chironomidae showed differential activity towards metals.

PubMed

Chong, Isaac K W; Ho, Wing S

2013-09-01

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is known to interact with different biomolecules and was implicated in many novel cellular activities including programmed cell death, nuclear RNA transport unrelated to the commonly known carbohydrate metabolism. We reported here the purification of GAPDH from Chironomidae larvae (Insecta, Diptera) that showed different biologic activity towards heavy metals. It was inhibited by copper, cobalt nickel, iron and lead but was activated by zinc. The GAPDH was purified by ammonium sulphate fractionation and Chelating Sepharose CL-6B chromatography followed by Blue Sepharose CL-6B chromatography. The 150-kDa tetrameric GAPDH showed optimal activity at pH 8.5 and 37°C. The multiple alignment of sequence of the Chironomidae GAPDH with other known species showed 78 - 88% identity to the conserved regions of the GADPH. Bioinformatic analysis unveils substantial N-terminal sequence similarity of GAPDH of Chironomidae larvae to mammalian GADPHs. However, the GADPH of Chironomidae larvae showed different biologic activities and cytotoxicity towards heavy metals. The GAPDH enzyme would undergo adaptive molecular changes through binding at the active site leading to higher tolerance to heavy metals.

Urban Land: Study of Surface Run-off Composition and Its Dynamics

NASA Astrophysics Data System (ADS)

Palagin, E. D.; Gridneva, M. A.; Bykova, P. G.

2017-11-01

The qualitative composition of urban land surface run-off is liable to significant variations. To study surface run-off dynamics, to examine its behaviour and to discover reasons of these variations, it is relevant to use the mathematical apparatus technique of time series analysis. A seasonal decomposition procedure was applied to a temporary series of monthly dynamics with the annual frequency of seasonal variations in connection with a multiplicative model. The results of the quantitative chemical analysis of surface wastewater of the 22nd Partsjezd outlet in Samara for the period of 2004-2016 were used as basic data. As a result of the analysis, a seasonal pattern of variations in the composition of surface run-off in Samara was identified. Seasonal indices upon 15 waste-water quality indicators were defined. BOD (full), suspended materials, mineralization, chlorides, sulphates, ammonium-ion, nitrite-anion, nitrate-anion, phosphates (phosphorus), iron general, copper, zinc, aluminium, petroleum products, synthetic surfactants (anion-active). Based on the seasonal decomposition of the time series data, the contribution of trends, seasonal and accidental components of the variability of the surface run-off indicators was estimated.

Gut Health of Pigs: Challenge Models and Response Criteria with a Critical Analysis of the Effectiveness of Selected Feed Additives - A Review.

PubMed

Adewole, D I; Kim, I H; Nyachoti, C M

2016-07-01

The gut is the largest organ that helps with the immune function. Gut health, especially in young pigs has a significant benefit to health and performance. In an attempt to maintain and enhance intestinal health in pigs and improve productivity in the absence of in-feed antibiotics, researchers have evaluated a wide range of feed additives. Some of these additives such as zinc oxide, copper sulphate, egg yolk antibodies, mannan-oligosaccharides and spray dried porcine plasma and their effectiveness are discussed in this review. One approach to evaluate the effectiveness of these additives in vivo is to use an appropriate disease challenge model. Over the years, researchers have used a number of challenge models which include the use of specific strains of enterotoxigenic Escherichia coli, bacteria lipopolysaccharide challenge, oral challenge with Salmonella enteric serotype Typhimurium, sanitation challenge, and Lawsonia intercellularis challenge. These challenge models together with the criteria used to evaluate the responses of the animals to them are also discussed in this review.

Gut Health of Pigs: Challenge Models and Response Criteria with a Critical Analysis of the Effectiveness of Selected Feed Additives — A Review

PubMed Central

Adewole, D. I.; Kim, I. H.; Nyachoti, C. M.

2016-01-01

The gut is the largest organ that helps with the immune function. Gut health, especially in young pigs has a significant benefit to health and performance. In an attempt to maintain and enhance intestinal health in pigs and improve productivity in the absence of in-feed antibiotics, researchers have evaluated a wide range of feed additives. Some of these additives such as zinc oxide, copper sulphate, egg yolk antibodies, mannan-oligosaccharides and spray dried porcine plasma and their effectiveness are discussed in this review. One approach to evaluate the effectiveness of these additives in vivo is to use an appropriate disease challenge model. Over the years, researchers have used a number of challenge models which include the use of specific strains of enterotoxigenic Escherichia coli, bacteria lipopolysaccharide challenge, oral challenge with Salmonella enteric serotype Typhimurium, sanitation challenge, and Lawsonia intercellularis challenge. These challenge models together with the criteria used to evaluate the responses of the animals to them are also discussed in this review. PMID:26954144