WorldWideScience

Sample records for 2-propanol

  1. Partial oxidation of 2-propanol on perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Sumathi, R.; Viswanathan, B.; Varadarajan, T.K. [Indian Inst. of Tech., Madras (India). Dept. of Chemistry

    1998-12-31

    Partial oxidation of 2-propanol was carried out on AB{sub 1-x}B`{sub x}O{sub 3} (A=Ba, B=Pb, Ce, Ti; B`=Bi, Sb and Cu) type perovskite oxides. Acetone was the major product observed on all the catalysts. All the catalysts underwent partial reduction during the reaction depending on the composition of the reactant, nature of the B site cation and the extent of substitution at B site. The catalytic activity has been correlated with the reducibility of the perovskite oxides determined from Temperature Programmed Reduction (TPR) studies. (orig.)

  2. Mixtures of methanol and 2-propanol as a potential fuel for direct alcohol fuel cells

    Directory of Open Access Journals (Sweden)

    S. LJ. GOJKOVIC

    2007-12-01

    Full Text Available The electrochemical oxidation of methanol, 2-propanol, and their mixtures was investigated on a Pt/C thin film electrode in acid solution. It was confirmed that the oxidation of 2-propanol commences at less positive potentials than that of methanol and exhibits significantly higher oxidation current densities at low potentials. When both methanol and 2-propanol were present in the solution, the onset of the oxidation current was the same as for the oxidation of pure 2-propanol. Although both alcohols inhibit the oxidation reaction of each other to a certain extent, steady-state polarization measurements showed that their mixture provides higher current densities than single alcohols over the entire potential region from the hydrogen region to oxide formation on the Pt surface. This implies that the addition of 2-propanol into the fuel may extend the operational range of direct methanol fuel cells.

  3. Structure and dynamics of aqueous 2-propanol: a THz-TDS, NMR and neutron diffraction study.

    Science.gov (United States)

    McGregor, James; Li, Ruoyu; Zeitler, J Axel; D'Agostino, Carmine; Collins, James H P; Mantle, Mick D; Manyar, Haresh; Holbrey, John D; Falkowska, Marta; Youngs, Tristan G A; Hardacre, Christopher; Stitt, E Hugh; Gladden, Lynn F

    2015-11-11

    Aqueous liquid mixtures, in particular, those involving amphiphilic species, play an important role in many physical, chemical and biological processes. Of particular interest are alcohol/water mixtures; however, the structural dynamics of such systems are still not fully understood. Herein, a combination of terahertz time-domain spectroscopy (THz-TDS) and NMR relaxation time analysis has been applied to investigate 2-propanol/water mixtures across the entire composition range; while neutron diffraction studies have been carried out at two specific concentrations. Excellent agreement is seen between the techniques with a maximum in both the relative absorption coefficient and the activation energy to molecular motion occurring at ∼90 mol% H2O. Furthermore, this is the same value at which well-established excess thermodynamic functions exhibit a maximum/minimum. Additionally, both neutron diffraction and THz-TDS have been used to provide estimates of the size of the hydration shell around 2-propanol in solution. Both methods determine that between 4 and 5 H2O molecules per 2-propanol are found in the 2-propanol/water clusters at 90 mol% H2O. Based on the acquired data, a description of the structure of 2-propanol/water across the composition range is presented.

  4. Molecular conformation and liquid structure of 2-propanol through neutron diffraction

    Indian Academy of Sciences (India)

    A Sahoo; S Sarkar; P S R Krishna; R N Joarder

    2010-05-01

    The neutron diffraction data analysis of deuterated liquid 2-propanol at room temperature to define its molecular conformation is presented. 2-Propanol being a large molecule with twelve atomic sites, the conformation analysis is tricky and an improved method of data analysis is given. The intermolecular structural correlations, i.e., hydrogen-bonded liquid structure, can be modelled accurately to extract the nature of the average hydrogen-bonded molecular association in liquid state at room temperature. Like other alcohols these are mostly hexamer ring chain (HRC) clusters. The cluster analysis of recent X-ray data available in the literature also support the same liquid structure.

  5. Analysis of Mesoscopic Structured 2-Propanol/Water Mixtures Using Pressure Perturbation Calorimetry and Molecular Dynamic Simulation.

    Science.gov (United States)

    Bye, Jordan W; Freeman, Colin L; Howard, John D; Herz, Gregor; McGregor, James; Falconer, Robert J

    2017-01-01

    In this paper we demonstrate the application of pressure perturbation calorimetry (PPC) to the characterization of 2-propanol/water mixtures. PPC of different 2-propanol/water mixtures provides two useful measurements: (i) the change in heat (ΔQ); and (ii) the [Formula: see text] value. The results demonstrate that the ΔQ values of the mixtures deviate from that expected for a random mixture, with a maximum at ~20-25 mol% 2-propanol. This coincides with the concentration at which molecular dynamics (MD) simulations show a maximum deviation from random distribution, and also the point at which alcohol-alcohol hydrogen bonds become dominant over alcohol-water hydrogen bonds. Furthermore, the [Formula: see text] value showed transitions at 2.5 mol% 2-propanol and at approximately 14 mol% 2-propanol. Below 2.5 mol% 2-propanol the values of [Formula: see text] are negative; this is indicative of the presence of isolated 2-propanol molecules surrounded by water molecules. Above 2.5 mol% 2-propanol [Formula: see text] rises, reaching a maximum at ~14 mol% corresponding to a point where mixed alcohol-water networks are thought to dominate. The values and trends identified by PPC show excellent agreement not only with those obtained from MD simulations but also with results in the literature derived using viscometry, THz spectroscopy, NMR and neutron diffraction.

  6. Characterization of the products formed by the reaction of trichlorocyanuric acid with 2-propanol.

    Science.gov (United States)

    Sandercock, P Mark L; Barnett, Julie S

    2009-11-01

    We report a recent investigation into the death of a cat that was initially thought to involve intentionally burning the animal via the use of an ignitable liquid. The exposure of the animal to flame was ruled out. Instead, forensic investigation revealed the intentional mixing together of a common outdoor swimming pool chlorinator, trichlorocyanuric acid (TCCA), and 2-propanol (aka, isopropyl alcohol or rubbing alcohol). The reaction of these two chemicals resulted in the formation of cyanuric acid residue, hydrochloric acid, and the evolution of a significant volume of chlorine gas. Further alpha-chlorination side reactions also occurred between 2-propanol and TCCA to produce a variety of chlorinated 2-propanone species that were detected on the submitted evidence. The identification of the products of both the main reaction and the side reactions allowed the authors to determine what chemicals were originally mixed together by the culprit.

  7. Measurement and Correlation of Solubility for Propylene in 2-Propanol-Water Solutions

    Institute of Scientific and Technical Information of China (English)

    刘国柱; 任永利; 米镇涛; 吴玉龙

    2003-01-01

    In order to obtain the solubility data of propylene in 2-propanol-water solutions, gas-liquid equilibrium (GLE) experiments were carried out at 303.15-333.15 K, 0.27-0.98 MPa in a static equilibrium still. The original mass ratio of 2-propanol to water was 9∶1,8∶2,7∶3,1∶0, respectively. The equilibrium data were correlated with an empirical model and the regression of model parameters was completed by Gauss-Newton nonlinear least square (NLS). The average relative deviation (ARD) between the experimental and calculated value is 1.5700, and the maximum relative deviation (MRD) is 4.8200. In addition, a simple approach that correlated the model parameters with the system composition was also provided.

  8. Gas Chromatography Method of Cleaning Validation Process for 2-Propanol Residue Determination in Pharmaceutical Manufacturing Equipment

    Directory of Open Access Journals (Sweden)

    Łukasz Czubak

    2014-07-01

    Full Text Available Cleaning validation is an integral operation of good manufacturing practice in pharmaceutical industry. The aim of this study was to validate simple analytical method for detection of 2-propanol residue in equipment, which is likely contaminated with 2-propanol, usually used in the production area. The gas chromatography with flame ionization detection (GC-FID method was validated on a GC system using DB-FFAP capillary column at the flow rate of 4.9 mL/min. The calibration curve was linear over concentration range from 2.8µg/mL to 110.7µg/mL with a correlation coefficient equal to 0.99981. The detection limit (LOD and quantitation limit (LOQ were 1.1µg/mL and 2.8µg/mL, respectively. The simplicity of gas chromatography method makes it useful for routine analysis of 2-propanol residue and is an alternative to corresponding methods.

  9. An investigation into the electro-oxidation of ethanol and 2-propanol for application in direct alcohol fuel cells (DAFCs)

    Indian Academy of Sciences (India)

    Sagar Sen Gupta; Jayati Datta

    2005-07-01

    A comparative study of the electro-oxidation of ethanol and 2-propanol was carried out on carbon-supported platinum particles. Cyclic voltammetry, steady state polarisation, and electrochemical impedance spectroscopy were used to investigate the oxidation reactions. A difference in the mechanistic behaviour of the oxidation of ethanol and 2-propanol on Pt was observed, thereby highlighting the fact that the molecular structure of the alcohol has great influence on its electroreactivity. The study emphasizes the fact that 2-propanol is a promising fuel candidate for a direct alcohol fuel cell.

  10. Ultrasonic study on molecular interactions in binary mixtures of formamide with 1-propanol or 2-propanol

    Institute of Scientific and Technical Information of China (English)

    Manju Rani; Suman Gahlyan; Ankur Gaur; Sanjeev Maken

    2015-01-01

    Ultrasonic speeds have been measured at 298.15 K and 308.15 K for mixtures of formamide+1-propanol or 2-propanol. For an equimolar mixture, excess molar compressibility follows the sequence of 1-propanol N 2-propanol. The ultrasonic speed data are correlated by various correlations such as Nomoto's relation, van Dael's mixing relation and impedance dependence relation, and analyzed in terms of Jacobson's free length theory and Schaaff's collision factor theory. Excess isentropic compressibility is calculated from ex-perimental ultrasonic speed data and previously reported excess volume data. The excess molar ultrasonic speed and isentropic compressibility values are fitted to Redlich–Kister polynomial equation. Other proper-ties such as molecular association, avallable volume, free volume, and intermolecular free length are also calculated. The excess isentropic compressibility data are also interpreted in terms of graph theoretical ap-proach. The calculated isentropic compressibility values are well consistent with the experimental data. It is found that the interaction between formamide and propanol increases when hydroxyl group attached to a carbon atom has more–CH3 groups.

  11. Correlation and Prediction of Salt Effect on Vapor Liquid Equilibrium for the System of 2-Propanol/Water

    Institute of Scientific and Technical Information of China (English)

    Fu Jiquan

    2008-01-01

    Binary vapor liquid equilibrium (VLE) data were measured for the systems of 2-propanol/ethanediol and ethanediol/potassium acetate (KAc). VLE data for the system of propanol/ethanediol was tested using thermodynamic consistency test. The average values of Δy1 and ΔP were 0.0776 and 0.1542 kPa, respectively. The above two sets of VLE data were correlated with the NRTL model. Ternary VLE data for the system of 2-propanol/water/KAc was used to obtain the more suitable parameters of NRTL model for binary systems of 2-propanol/KAc and water/KAC (called TDCM). For multicomponent systems, ternary and quaternary, the VLE values predicted by the NRTL model agreed well with the literature data. Influence of KAc, ethanediol, and the mixture of KAc and ethanediol on volatility between 2propanol and water was investigated respectively. The results showed that the above-mentioned materials and mixture had different influence on volatility between 2-propanol and water. The method for correlation and prediction of salt-containing VLE is simple and effective for the said system.

  12. Preparasi Bentonit Terpilar Alumina dari Bentonit Alam dan Pemanfaatannya sebagai Katalis pada Reaksi Dehidrasi Etanol, 1-Propanol serta 2-Propanol

    Directory of Open Access Journals (Sweden)

    Surya Lubis

    2007-12-01

    Full Text Available Penelitian tentang modifikasi bentonit dari Kuala Dewa, Aceh Utara menjadi bentonit terpilar alumina dan uji aktivitasnya pada reaksi dehidrasi etanol, 1-propanol dan 2-propanol telah dilakukan. Bentonit alam (Ca-bentonit dimodifikasi melalui proses pertukaran kation menjadi Na-bentonit dan H-bentonit, kemudian dipilarisasi menggunakan AlCl3 dan NaOH menghasilkan bentonit terpilar alumina. Bentonit terpilar alumina yang diperoleh mempunyai luas permukaan spesifik (72,42 m2/gram yang lebih besar dibanding dengan bentonit tidak terpilar. Uji aktivitas katalitis bentonit terpilar alumina pada reaksi dehidrasi etanol, 1-propanol dan 2-propanol dilakukan pada suhu 200°C - 400°C. Suhu optimum reaksi dehidrasi etanol, 1-propanol dan 2-propanol menggunakan katalis bentonit terpilar alumina berturutturut adalah 250, 400 dan 200°C dengan konsentrasi dietil eter 25,44; 2,31 dan 3,29%. Aktivitas katalis bentonit terpilar alumina pada reaksi dehidrasi alkohol sesuai dengan urutan etanol > 2-propanol > 1-propanol. Kata kunci: bentonit terpilar alumina, dehidrasi, etanol, 1-propanol, 2-propanol

  13. Isopropylation of benzene with 2-propanol over substituted large pore aluminophosphate-based molecular sieves

    Indian Academy of Sciences (India)

    K Joseph Antony Raj; V R Vijayaraghavan

    2004-03-01

    Large pore aluminophosphate-based molecular sieves like AlPO4-5, MAPO-5, MnAPO-5 and ZAPO-5 were synthesised hydrothermally using triethylamine as a structure directing agent. These materials were characterised by X-ray diffraction (XRD), 27Al and 31P MAS-NMR, ICP-MS, -butylamine- TPD, BET and SEM. The catalytic performance of these materials was tested for isopropylation of benzene with 2-propanol at 250, 300, 350 and 400°C. The products were cumene, -DIPB (-diisopropylbenzene) and -DIPB (-diisopropylbenzene). MnAPO-5 was found to be more active than the other catalysts. Maximum conversion (20%) was noted at 350°C over MnAPO-5. The selectivity to DIPB was found to decrease with time on stream but the selectivity to cumene showed an increase after 3 h of time on stream.

  14. Fourier transformed infrared spectral investigations of molecular interactions in propionic acid-2-propanol binary system.

    Science.gov (United States)

    Umadevi, M; Thomas, Ammu Elizabeth

    2010-04-01

    FTIR spectra of propionic acid (PA), 2-propanol (PROH) and its binary mixtures with varying molefraction of the PA were recorded in the region 500-3500 cm(-1), to investigate the formation of hydrogen bonded complexes in a mixed system. The observed features in nu(CO), nu(CO) and delta(COH) of PA, nu(CO) of PROH and delta(COH) of PA+PROH have been explained in terms of the hydrogen bonding interactions between PROH and PA and dipole-dipole interaction. The dipole moment derivative for the above mentioned vibrational modes have also been predicted from the integrated absorbance. The intrinsic linewidth for the vibrational modes nu(CO) and delta(COH) of PA has been elucidated using Bondarev and Mardaeva model.

  15. 1-Phenoxy-2-propanol is a useful anaesthetic for gastropods used in neurophysiology.

    Science.gov (United States)

    Wyeth, Russell C; Croll, Roger P; Willows, A O Dennis; Spencer, Andrew N

    2009-01-30

    Anaesthesia is often used in neurophysiological, surgical, and neuroanatomical protocols. Several anaesthetics, including magnesium chloride, volatiles (halothane, etc.), and barbiturates, have been used in gastropod neurobiology. 1-Phenoxy-2-propanol (PP) is another anaesthetic option that has not yet been used extensively. We provide an analysis of the neural, muscular and behavioural effects of PP in gastropods. PP eliminates action potentials and reduces muscular contraction force in Hermissenda crassicornis, and eliminates behavioural activity in Tritonia diomedea. Our results show these effects are reversible, with complete action potential recovery, at least partial muscular recovery, and full behavioural recovery. Survival after surgery in T. diomedea was longer with PP than without anaesthetic, and PP also reduced contraction during tissue fixation in Lymnaea stagnalis. Moreover, PP can be bath applied, has low toxicity, and is biodegradable. Thus, PP is an effective anaesthetic in three species of gastropods, and useful in neurophysiological dissection, surgical, and fixation protocols.

  16. PHOTOREDUCTION OF ALKYL VIOLOGENS AND POLYVIOLOGENS IN 2-PROPANOL AQUEOUS SOLUTION

    Institute of Scientific and Technical Information of China (English)

    LIANG Zhaoxi; LI Wen; LI Manfu

    1987-01-01

    In order to study the effect of alkyl chain length and the polymer effect on the photoreduction behavior of some viologens, a series of alkyl viologen, polyviologen and bisviologen compounds have been synthesized. In the presence of excess 2-propanol, the initial photoreduction of alkyl viologens and polyviologens follow the peudo-second-order reaction, the calculated rate constants are related to the alkyl chain length. In addition, the intramolecular association of radical cations of polyviologens has been found even in dilute solution. However the extent of association is varied with the alkyl chain length. The observed polymer effect of polyviologens in the photoreduction is significant which can be explained in terms of the nature of second order reaction.

  17. LET and dose rate effect on radiation-induced copolymerization of maleimide with styrene in 2-propanol solution

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Seiko, E-mail: Nakagawa.Seiko@iri-tokyo.jp [Tokyo Metropolitan Industrial Technology Research Institute, 2-4-10 Aoumi, Koto-ku, Tokyo 135-0064 (Japan); Taguchi, Mitsumasa; Kimura, Atsushi [Environmental Radiation Processing Group, Environment and Industrial Materials Research Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2011-11-15

    N{sub 2}-saturated 2-propanol solutions containing styrene and maleimide were irradiated by electron, proton, He and C-ion beams. The styrene-maleimide copolymer was produced by radical polymerization induced during irradiation. The effects of the radical distribution, which depends on the LET or dose rate, on the molecular weight and the polymer yield were discussed. - Highlights: > Maleimide with styrene in N{sub 2}-saturated 2-propanol was irradiated by electron and heavy ions. > LET and dose rate effects of radical polymerization induced by irradiation were studied. > Results have shown the relation between radical distribution and efficiency of polymerization.

  18. Acute sensory irritation from exposure to isopropanol(2-propanol) at TLV in workers and controls : objective versus subjective effects

    NARCIS (Netherlands)

    Smeets, M.A.M.; Maute, C.; Dalton, P.H.

    2002-01-01

    Objectives. Phlebotomists occupationally exposed to isopropanol (IPA) (2-propanol) and naïve controls (n = 12 per group) were exposed to the time-weighted average threshold limit value of 400 p.p.m. IPA for 4 h in an environmental chamber to investigate: (i) acute effects of sensory irritation using

  19. Study on Salt-Containing Extractive Distillation for the 2-Propanol/Water System

    Institute of Scientific and Technical Information of China (English)

    Fu Jiquan

    2008-01-01

    The salt-containing extractive distillation column and the salt-containing agent recovery column for the 2-propanol/water/ethanediol/KAc system were simulated by the NRTL model and the modified Rose Relaxation method. The simulation results showed that prediction of the salt effect in vapor-liquid equilib-rium and the correlation method (TDCM) of NRTL parameters were suitable for the said system. Four different distillation technology processes were investigated; the results showed that the salt-containing extractive distillation process was the best one. The simulating design of the extractive distillation column was performed under the conditions of different total stage number, feeding location, reflux ratio, amount of mixed agent and concentration of KAc. The results showed that such factors as 17 stages, a feeding location at the 9th stage, a reflux ratio of 1.2, and a mixed agent feeding rate of 1.141 kmol/h, might be the best suited operating conditions. The simulating design was also done for the column for recovering the salt-containing agent. The simulation method of the salt-containing extractive distillation is simple and effective in this work.

  20. Studi Reaksi Konversi Katalisis 2-Propanol Menggunakan Katalis dan Pendukung Katalis γ-Al2O3

    Directory of Open Access Journals (Sweden)

    Sunardi Sunardi

    2007-10-01

    Full Text Available Katalis padatan basa belum digunakan secara luas bila dibandingkan dengan penggunaan katalis padatan asam, meskipun katalis padatan basa secara efisien juga mampu berperan dalam reaksi-reaksi seperti alkilasi, kondensasi, isomerisasi dan lain-lain. Pada penelitian ini dilakukan studi reaksi konversi katalisis 2-propanol menggunakan katalis padatan basa Mg-Al-Hidrotalsit dan katalis padatan superbasa g-Al2O3-NaOH-Na yang dibandingkan dengan katalis γ-Al2O3. Reaksi katalisis dilakukan dalam fase gas dengan variasi suhu dari 175oC sampai suhu 300oC, menggunakan katalis seberat 3 gram. Produk reaksi katalisis dianalisis dengan kromatografi gas, yang dirangkai secara on-line dengan reaktor katalisis. Propilen dan aseton merupakan produk-produk primer reaksi konversi yang mudah bereaksi lebih lanjut menghasilkan produk-produk sekunder yang stabil. Katalis γ-Al2O3 hanya mengkonversi 2-propanol menjadi propilen, karena sifat basanya tidak cukup kuat untuk mendorong reaksi dehidrogenasi 2-propanol menjadi aseton. Katalis Mg-Al-hidrotalsit mengkonversi hampir 100% 2-propanol menjadi propilen pada suhu 175oC dan menghasilkan aseton paling banyak pada 225oC dengan konversi produk sebesar 53,36 %, sedangkan dengan katalis superbasa γ-Al2O3-NaOH-Na diperoleh konversi aseton sebesar 66,0% pada 225oC. Produkproduksekunder hasil konversi 2-propanol dengan katalis Mg-Al-hidrotalsit secara batch diidentifikasi dengan GC-MS dan diperoleh senyawa yang dominan adalah 4-metil-2-pentanol dan 3,3,5-trimetil sikloheksanol. Copyright (c 2007 BCREC UNDIP. All rights reserved.[Presented at Symposium and Congress of MKICS 2007, 18-19 April 2007, Semarang, Indonesia][How to Cite: W. Wibowo, S. Sunardi, I. Yulia. (2007. Studi Reaksi Konversi Katalisis 2-Propanol Menggunakan Katalis dan Pendukung Katalis γ-Al2O3. Bulletin of Chemical Reaction Engineering and Catalysis, 2 (2-3: 56-61. doi:10.9767/bcrec.2.2-3.11.56-61][How to Link/DOI: http://dx.doi.org/10.9767/bcrec.2.2-3.8.56-61

  1. Studi Reaksi Konversi Katalisis 2-Propanol Menggunakan Katalis dan Pendukung Katalis γ-Al2O3

    Directory of Open Access Journals (Sweden)

    Widajanti Wibowo

    2007-10-01

    Full Text Available Katalis padatan basa belum digunakan secara luas bila dibandingkan dengan penggunaan katalis padatan asam, meskipun katalis padatan basa secara efisien juga mampu berperan dalam reaksi-reaksi seperti alkilasi, kondensasi, isomerisasi dan lain-lain. Pada penelitian ini dilakukan studi reaksi konversi katalisis 2-propanol menggunakan katalis padatan basa Mg-Al-Hidrotalsit dan katalis padatan superbasa g-Al2O3-NaOH-Na yang dibandingkan dengan katalis γ-Al2O3. Reaksi katalisis dilakukan dalam fase gas dengan variasi suhu dari 175oC sampai suhu 300oC, menggunakan katalis seberat 3 gram. Produk reaksi katalisis dianalisis dengan kromatografi gas, yang dirangkai secara on-line dengan reaktor katalisis. Propilen dan aseton merupakan produk-produk primer reaksi konversi yang mudah bereaksi lebih lanjut menghasilkan produk-produk sekunder yang stabil. Katalis γ-Al2O3 hanya mengkonversi 2-propanol menjadi propilen, karena sifat basanya tidak cukup kuat untuk mendorong reaksi dehidrogenasi 2-propanol menjadi aseton. Katalis Mg-Al-hidrotalsit mengkonversi hampir 100% 2-propanol menjadi propilen pada suhu 175oC dan menghasilkan aseton paling banyak pada 225oC dengan konversi produk sebesar 53,36 %, sedangkan dengan katalis superbasa γ-Al2O3-NaOH-Na diperoleh konversi aseton sebesar 66,0% pada 225oC. Produkproduksekunder hasil konversi 2-propanol dengan katalis Mg-Al-hidrotalsit secara batch diidentifikasi dengan GC-MS dan diperoleh senyawa yang dominan adalah 4-metil-2-pentanol dan 3,3,5-trimetil sikloheksanol. Copyright (c 2007 BCREC UNDIP. All rights reserved.[Presented at Symposium and Congress of MKICS 2007, 18-19 April 2007, Semarang, Indonesia][How to Cite: W. Wibowo, S. Sunardi, I. Yulia. (2007. Studi Reaksi Konversi Katalisis 2-Propanol Menggunakan Katalis dan Pendukung Katalis γ-Al2O3. Bulletin of Chemical Reaction Engineering and Catalysis, 2 (2-3: 56-61.  doi:10.9767/bcrec.2.2-3.7131.56-61][How to Link/DOI: http://dx.doi.org/10.9767/bcrec.2

  2. Effect of (+)-limonene and 1-methoxy-2-propanol on Ips typographus response to pheromone blends

    Institute of Scientific and Technical Information of China (English)

    Miroslav Bla(z)enec; Rastislav Jaku(s)

    2009-01-01

    We compared two different strategies to increase the catches of Ips typographus (L.), particularly males, in pheromone-baited traps. The first of these strategies, the barrier approach, used alternating pheromone blends, targeting males and females respectively, in closely-spaced traps forming a barrier around forest stands. The second strategy, the single trap approach, used widely-spaced traps that were all baited with the same lure and intended to trap the highest possible numbers of males without compromising trapping of females. In the blend used for the barrier traps targeting primarily males, with a lower percentage of (4S)-cis-verbenol (cV), the (-)-α-pinene was replaced step wise with (+)-limonene at rates of 0%, 1%, 10%, 35%, 60% and 90%. This replacement had no significant effect on the numbers of responding I. Typographus males, but there was a slight effect on the percentage of males caught. In the attractant blend for the barrier traps targeting females, with a higher percentage of cV, the 2-methyl-3-buten-2-ol (MB) was replaced with 1-methoxy-2-propanol (MP) in a similar fashion as for the male-specific blends. The replacement did not significantly affect the catch of females. Thus, it is possible to use the MP in the blend with cV and ipsdienol without significant change in catch efficacy. In the blends for single traps, the (-)-α-pinene was replaced with (+)-limonene and MB with MP. The replacement of (-)-α-pinene had only a slight effect on the percentage of males, but the results suggest that replacing MB with MP in the blend will not significantly reduce trapping efficacy.

  3. Measurement and Modeling of Vapor-Liquid Equilibrium for Ternary System Water+2-Propanol+1-Butyl-3-methylimidazolium Chloride

    Institute of Scientific and Technical Information of China (English)

    邓东顺; 乔玉珍; 姬登祥; 葛筠; 章连众

    2014-01-01

    Vapor-liquid equilibrium (VLE) data for water+2-propanol+1-butyl-3-methylimidazolium chloride ([bmim]Cl) were measured. Six sets of complete T, x, y data are reported, in which the 2-propanol mole fraction on IL-free basis is fixed separately at 0.1, 0.2, 0.4, 0.6, 0.8, and approximate 0.98, while the IL mass fraction is varied from 0.1 to 0.8, in an interval of 0.1. The non-random-two-liquid (NRTL) and electrolyte non-random-two-liquid (eNRTL) equations are used to correlate the experimental data with satisfactory results. The ternary VLE behavior is also modeled with the parameters obtained by correlating two data sets, in which the mole fraction of 2-propanol on IL-free basis is approximately 0.1 and 0.98. In this way, the six sets of data are reproduced satisfactorily. With the eNRTL model, the root-mean-square deviation for temperature is 0.82 K and that for vapor-phase mole fraction is 0.0078. The influences of IL on activity coefficients and relative volatility of the volatile components are also graphically illustrated.

  4. Studies on Dechlorination of DDT with Alkaline 2-propanol and Iron-Nickel (Fe-Ni) Catalyst.

    Science.gov (United States)

    Shareef, A.; Zaman, S. U.

    2009-05-01

    The Persistent Organic Pollutants (POPs) pesticides were previously extensively used in the cotton production and other agricultural activities in Pakistan and at least three thousand metric tons of obsolete pesticides have been stored under extreme hazardous conditions in more than thousand sites. Locally banned or severely restricted pesticides are easily available and DDT is continuously illegally imported and use in our country. Elimination of organochlorine pesticides (OCPs) waste has received considerable attention over the past two decades. Existing catalytic hydrodechlorinated techniques for disposing of OCPs are very costly due to the use of noble metals as catalysts. The aim of our study is to develop the cost effective and efficient method for the safe disposal of OCPs. This study is in continuation work on dechlorination of organochlorine pesticides with Fe-Ni catalyst in alkaline 2-propanol media. We turned our attention to the development of DDT disposal method for the third world countries. Herein, we report our first finding that in alkaline 2-propanol with Fe-Ni catalyst is an effective method for dechlorination of DDT. Catalytic dechlorination of DDT was carried out in an alkaline solution of NaOH and 2-propanol in the presence of catalyst at the temperature below 82 oC and end products were analyzed by using Gas Chromatography (GC-ECD) and Ion Chromatography (IC) techniques. Results obtained with initial concentration of DDT ranging between 10-100 μg/ml showed conversion of DDT to chlorine free product within 4 hrs.

  5. Inhibition of alcohol dehydrogenase after 2-propanol exposure in different geographic races of Drosophila mojavensis: lack of evidence for selection at the Adh-2 locus.

    Science.gov (United States)

    Pfeiler, Edward; Reed, Laura K; Markow, Therese A

    2005-03-15

    High frequencies of the fast allele of alcohol dehydrogenase-2 (Adh-2F) are found in populations of Drosophila mojavensis that inhabit the Baja California peninsula (race BII) whereas the slow allele (Adh-2S) predominates at most other localities within the species' geographic range. Race BII flies utilize necrotic tissue of pitaya agria cactus (Stenocereus gummosus) which contains high levels of 2-propanol, whereas flies from most other localities utilize different cactus hosts in which 2-propanol levels are low. To test if 2-propanol acts as a selective force on Adh-2 genotype, or whether some other yet undetermined genetic factor is responsible, mature males of D. mojavensis lines derived from the Grand Canyon (race A) and Santa Catalina Island (race C), each with individuals homozygous for Adh-2F and Adh-2S, were exposed to 2-propanol for 24 h and ADH-2 specific activity was then determined on each genotype. Flies from five other localities homozygous for either the fast or slow allele also were examined. Results for all reported races of D. mojavensis were obtained. 2-propanol exposure inhibited ADH-2 specific activity in both genotypes from all localities, but inhibition was significantly less in two populations of race BII flies homozygous for Adh-2F. When F/F and S/S genotypes in flies from the same locality were compared, both genotypes showed high 2-propanol inhibition that was not statistically different, indicating that the F/F genotype alone does not provide a benefit against the inhibitory effects of 2-propanol. ADH-1 activity in female ovaries was inhibited less by 2-propanol than ADH-2. These results do not support the hypothesis that 2-propanol acts as a selective factor favoring the Adh-2F allele.

  6. Quaternary liquid/liquid equilibria of sodium sulfate, sodium sulfite and water with two solvents: Acetone and 2-propanol

    Energy Technology Data Exchange (ETDEWEB)

    Schiozer, A.L.

    1994-03-01

    Aqueous solutions of sodium sulfate and sodium sulfite are produced from sodium carbonate in flue-gas scrubbers; recovery of these salts often requires multi-effect evaporators; however, a new energy-efficient unit operation called extractive crystallization has been shown to have reduced energy costs. In this process, an organic solvent is added to the aqueous salt solution to precipitate salt. Acetone is a suitable solvent for this process, better than 2-propanol. Liquid/liquid/solid equilibria for ternary systems containing a salt, water, and an organic solvent were measured. Systems investigated were sodium sulfite/water/acetone and sodium sulfite/water/2-propanol. Experiments were conducted at salt saturation covering a temperature range between the lower consolute temperature and 48.6{degrees}C. In the attempt to improve the extractive crystallization process for recovery of sodium sulfate from flue-gas scrubbers, attention was given to a feed containing a mixture of sodium sulfite and sodium sulfate. Liquid-liquid equilibria for quaternary systems containing two salts, water, and an organic solvent were experimentally determined at 35{degrees}C. The systems investigated were sodium sulfate/sodium sulfite/water/acetone and sodium sulfate/sodium sulfite/water/2propanol. The systems were studied at three salt ratios. For each salt ratio, experiments were conducted starting at saturation, water was then added until the one-phase region was reached. Mixtures of the two salts proved to have a small disadvantage relative to the 100 % sulfate feed process. Therefore, a sulfate-based extractive crystallization process is recommended.

  7. Determination of 2-propanol in surface cleaning solutions used for copper continuous casting process by flow injection-spectrophotometric detection with on-line column separation.

    Science.gov (United States)

    Hayashibe, Yutaka; Tokuda, Masahiro; Takeya, Minoru

    2003-09-01

    A flow-injection system has been developed for the determination of 2-propanol in the surface cleaning solutions used in the copper continuous cast rod making system. Adsorption chromatography in nitric acid medium was used for the on-line separation of oily substances in the sample solution. Cerium(IV) diammonium nitrate was utilized as the chromogenic reagent for the spectrophotometric detection of 2-propanol. The system permits a throughput of one sample per hour for the oily sample, and of 12 samples per hour for the none-oily sample. The reproducibility has been proven to be satisfactory with a relative standard deviation of less than 6.0% (2.2%(V/V) 2-propanol level, n = 23). The detection limit is 0.01% (V/V).

  8. The electro-oxidation of the mixture of formaldehyde and 2-propanol on gold (100 and (111 single crystal planes in alkaline medium

    Directory of Open Access Journals (Sweden)

    BRANISLAV Z. NIKOLIC

    2000-12-01

    Full Text Available The effect of formaldehyde on the oxidation of 2-propanol and vice versa on gold single crystal planes (100 and 111 was studied. An activating effect in the reaction of the simultaneous oxidation of 2-propanol and formaldehyde was obtained on a gold (100 plane. In the case of a gold (111 electrode, the activation effect was not obtained. It was concluded that the adsorption of formaldehyde on the electrode surface prevents the adsorption of poisoning species formed during the electro-oxidation of 2-propanol on the Au(100 plane, while this is not the case on the Au(111 plane. The different behaviour is caused by the difference in the symmetry of the surface atoms of these two Au single-crystal planes.

  9. ELECTROCHEMICAL DETERMINATION OF ETHANOL, 2- PROPANOL AND 1-BUTANOL ON GLASSY CARBON ELECTRODE MODIFIED WITH NICKEL OXIDE FILM

    Directory of Open Access Journals (Sweden)

    A. Benchettara

    2015-07-01

    Full Text Available In this work, we present the modification of a glassy carbon electrode with nickel oxide film which is performed in two successive steps. In the first one, the electrochemical deposition of metallic nickel on the glassy carbon electrode (GCE is achieved in 0.1M boric acid; in the second step, the metallic deposit is anodically oxidized in 0.1M NaOH. These two operations were carried out in a three electrode cell with a filiform platinum auxiliary electrode, a SCE as potential reference and a working microelectrode of modified glassy carbon with nickel oxides. This electrode is characterized by several electrochemical techniques and is used for the catalytic determination of ethanol, 2-propanol and 1-butanol in 0.1 M NaOH. The proposed chemical mechanism shows that NiO2 acts as a mediator.

  10. ELECTROCHEMICAL DETERMINATION OF ETHANOL, 2- PROPANOL AND 1-BUTANOL ON GLASSY CARBON ELECTRODE MODIFIED WITH NICKEL OXIDE FILM

    Directory of Open Access Journals (Sweden)

    A. Benchettara

    2014-12-01

    Full Text Available In this work, we present the modification of a glassy carbon electrode with nickel oxide film which is performed in two successive steps. In the first one, the electrochemical deposition of metallic nickel on the glassy carbon electrode (GCE is achieved in 0.1M boric acid; in the second step, the metallic deposit is anodically oxidized in 0.1M NaOH. These two operations were carried out in a three electrode cell with a filiform platinum auxiliary electrode, a SCE as potential reference and a working microelectrode of modified glassy carbon with nickel oxides. This electrode is characterized by several electrochemical techniques and is used for the catalytic determination of ethanol, 2-propanol and 1-butanol in 0.1 M NaOH. The proposed chemical mechanism shows that NiO2 acts as a mediator.

  11. First European Report of Social Wasps Trapped in Response to Acetic acid, Isobutanol, 2-Methyl-2-propanol, and Heptyl butyrate in Tests Conducted in Hungary

    Science.gov (United States)

    Five species of social wasps were captured in trapping tests in Hungary that evaluated the attractiveness of acetic acid, isobutanol, 2-methyl-2-propanol, and heptyl butyrate to social wasps. Both Vespula vulgaris (L.) and Vespula germanica (Fabr.), were captured in traps baited with isobutanol, t...

  12. Experimental results of 2-propanol dehydrogenation with a falling-liquid film reactor for solar chemical heat pump; Solar chemical heat pump ni okeru ryuka ekimakushiki 2-propanol bunkai hanno jikken

    Energy Technology Data Exchange (ETDEWEB)

    Doi, T.; Tanaka, T.; Ando, Y.; Takashima, T. [Electrotechnical Laboratory, Tsukuba (Japan); Koike, M.; Kamoshida, J. [Shibaura Institute of Technology, Tokyo (Japan)

    1997-11-25

    A solar chemical heat pump is intended to attempt multi-purposed effective utilization of solar energy by raising low temperature solar heat of about 100 degC to 150 to 200 degC by utilizing chemical reactions. The chemical heat pump under the present study uses a 2-propanol (IPA)/acetone/hydrogen system which can utilize low-temperature solar heat and has large temperature rising degree. It was found from the result of experiments and analyses that IPA dehydrogenation reaction can improve more largely the heat utilization rate in using a falling-liquid film reactor than using a liquid phase suspended system. As an attempt to improve further the heat utilization rate, this paper reports the result of experimental discussions on inclination angles of a reaction vessel and feed liquid flow rate which would affect the fluid condition of the liquid film. As a result of the experiments, the initial deterioration in the catalyst has settled in about 15 hours, and its activity has decreased to about 60% of the initial activity. It was made clear that the influence of the inclination angle of the reaction vessel on the reaction is small. 5 refs., 7 figs.

  13. Photocatalytic Oxidation of Low-Level Airborne 2-Propanol and Trichloroethylene over Titania Irradiated with Bulb-Type Light-Emitting Diodes

    Directory of Open Access Journals (Sweden)

    Wan-Kuen Jo

    2013-01-01

    Full Text Available This study examined the photocatalytic oxidation of gas-phase trichloroethylene (TCE and 2-propanol, at indoor levels, over titanium dioxide (TiO2 irradiated with light-emitting diodes (LED under different operational conditions. TiO2 powder baked at 450 °C exhibited the highest photocatalytic decomposition efficiency (PDE for TCE, while all photocatalysts baked at different temperatures showed similar PDEs for 2-propanol. The average PDEs of TCE over a three hour period were four, four, five, and 51% for TiO2 powders baked at 150, 250, 350, and 450 °C, respectively. The average PDEs of 2-propanol were 95, 97, 98, and 96% for TiO2 powders baked at 150, 250, 350, and 450 °C, respectively. The ratio of anatase at 2θ = 25.2° to rutile at 2θ = 27.4° was lowest for the TiO2 powder baked at 450 °C. Although the LED-irradiated TiO2 system revealed lower PDEs of TCE and 2-propanol when compared to those of the eight watt, black-light lamp-irradiated TiO2 system, the results for the PDEs normalized to the energy consumption were reversed. Other operational parameters, such as relative humidity, input concentrations, flow rate, and feeding type were also found to influence the photocatalytic performance of the UV LED-irradiated TiO2 system when applied to the cleaning of TCE and 2-propanol at indoor air levels.

  14. Noninvasive biomarkers for acute hepatotoxicity induced by 1,3-dichloro-2-propanol: hyperpolarized 13C dynamic MR spectroscopy.

    Science.gov (United States)

    Kim, Gwang-Won; Oh, Chang-Hyun; Kim, Jong-Choon; Yoon, Woong; Jeong, Yong-Yeon; Kim, Yun-Hyeon; Kim, Jae-Kyu; Park, Jin-Gyoon; Kang, Heoung-Keun; Jeong, Gwang-Woo

    2016-02-01

    The purpose of this study was to investigate the cellular metabolite change for acute hepatotoxicity induced by 1,3-dichloro-2-propanol (1,3-DCP) in rats and its correlations with the enzyme levels. In order to induce acute hepatotoxicity, a single subcutaneous injection of 1,3-DCP (80 mg/kg) was given to six male Sprague-Dawley rats. Hyperpolarized (13)C dynamic magnetic resonance spectroscopy (MRS) was performed on rat liver following injection of hyperpolarized [1-(13)C] pyruvate. The levels of serum aspartate am inotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) in the 1,3-DCP treated rats were significantly increased as compared with those in normal rats. In the dynamic (13)C MR spectra, the ratios of [1-(13)C] lactate to the total carbon and [1-(13)C] alanine to the total carbon in the 1,3-DCP treated rats were significantly increased, and there were positive correlations between cellular metabolic changes and enzyme levels. The levels of [1-(13)C] lactate and [1-(13)C] alanine are potentially considered as important biomarkers for the 1,3-DCP-induced acute hepatotoxicity.

  15. Time-course and molecular mechanism of hepatotoxicity induced by 1,3-dichloro-2-propanol in rats.

    Science.gov (United States)

    Lee, In-Chul; Ko, Je-Won; Lee, Sang-Min; Kim, Sung-Hwan; Shin, In-Sik; Moon, Og-Sung; Yoon, Won-Kee; Kim, Hyoung-Chin; Kim, Jong-Choon

    2015-07-01

    This study investigated the time-course of 1,3-dichloro-2-propanol (1,3-DCP)-induced hepatotoxicity and the molecular mechanism of its oxidative stress and apoptotic changes in rats. Thirty-six male rats were randomly assigned to six groups of six rats each and were administered a single oral dose of 1,3-DCP (90 mg/kg) or its vehicle. 1,3-DCP caused acute hepatic damage, as evidenced by marked increases in serum aminotransferase, alkaline phosphatase, and histopathological alterations. These functional and histopathological changes in the liver peaked at 12h after administration and then decreased progressively. Oxidative stress indices were increased significantly at 6h, peaked at 12h, and then decreased progressively. The number of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)- and caspase-3-positive cells increased after 6h, peaked at 12 and 24h, and then decreased. The protein levels of phosphorylated mitogen-activated protein kinases (MAPKs) including p-Erk1/2 and p-JNK showed a similar trend to the numbers of TUNEL- and caspase-3-positive cells. These results indicate that 1,3-DCP increases oxidative stress, nuclear translocation of Nrf2, and expression of Nrf2-targeted genes, followed by increased functional and histopathological alterations in the liver. The increase in hepatocellular apoptosis induced by 1,3-DCP may be related to oxidative stress-mediated MAPK activation.

  16. Insight into the beneficial immunomodulatory mechanism of the sevoflurane metabolite hexafluoro-2-propanol in a rat model of endotoxaemia.

    Science.gov (United States)

    Urner, M; Schläpfer, M; Herrmann, I K; Hasler, M; Schimmer, R R; Booy, C; Roth Z'graggen, B; Rehrauer, H; Aigner, F; Minshall, R D; Stark, W J; Beck-Schimmer, B

    2015-09-01

    Volatile anaesthetics such as sevoflurane attenuate inflammatory processes, thereby impacting patient outcome significantly. Their inhalative administration is, however, strictly limited to controlled environments such as operating theatres, and thus an intravenously injectable immunomodulatory drug would offer distinct advantages. As protective effects of volatile anaesthetics have been associated with the presence of trifluorinated carbon groups in their basic structure, in this study we investigated the water-soluble sevoflurane metabolite hexafluoro-2-propanol (HFIP) as a potential immunomodulatory drug in a rat model of endotoxic shock. Male Wistar rats were subjected to intravenous lipopolysaccharide (LPS) and thereafter were treated with HFIP. Plasma and tissue inflammatory mediators, neutrophil invasion, tissue damage and haemodynamic stability were the dedicated end-points. In an endotoxin-induced endothelial cell injury model, underlying mechanisms were elucidated using gene expression and gene reporter analyses. HFIP reduced the systemic inflammatory response significantly and decreased endotoxin-induced tissue damage. Additionally, the LPS-provoked drop in blood pressure of animals was resolved by HFIP treatment. Pathway analysis revealed that the observed attenuation of the inflammatory process was associated with reduced nuclear factor kappa B (NF-κΒ) activation and suppression of its dependent transcripts. Taken together, intravenous administration of HFIP exerts promising immunomodulatory effects in endotoxaemic rats. The possibility of intravenous administration would overcome limitations of volatile anaesthetics, and thus HFIP might therefore represent an interesting future drug candidate for states of severe inflammation.

  17. Highly active dealloyed Cu@Pt core-shell electrocatalyst towards 2-propanol electrooxidation in acidic solution

    Science.gov (United States)

    Poochai, Chatwarin

    2017-02-01

    Dealloyed Cu@Pt core-shell electrocatalyst was fabricated by cyclic co-electrodeposition and selective Cu dealloying (CCEd-sCuD) on carbon paper (CP), namely Cu@Pt/CP. The Cu@Pt/CP exhibited a core-shell structure comprising with a Cu-rich core and a Pt-rich shell. The crystalline phases of Pt/CP and Cu@Pt/CP were a face-centered cubic (fcc). The compressive lattice strain approximately 0.85% was found in the Cu@Pt/CP owing to a lattice mismatch between a core and a shell region. In the core-region, Cu was formed Pt-Cu alloy as major and copper oxide and also metallic copper as minor. The morphology and grain size of the Cu@Pt/CP displayed a porous spherical shape with 100 nm in diameter, while those of Pt/CP seemed to be a cubic shape with smaller diameter of 40 nm. In electrochemical and catalytic activity, the surface of Cu@Pt/CP had a larger electrochemical active surface area (ECSA) than that of Pt/CP due to a porous formation caused by Cu dealloying. It is not surprising that the Cu@Pt/CP showed higher catalytic activity and greater stability towards 0.5 M 2-propanol electrooxidation in 0.5 M H2SO4 in terms of peak current density (jp), peak potential (Ep), onset potential (Eonset), diffusion coefficient (D), and charge transfer resistance (Rct) which were caused by electronic structure modification, higher compressive lattice strain, and larger ECSA, compared with Pt/CP.

  18. Kinetics of the hydrogenation of 2-chloro-4-nitroaniline over skeletal nickel and supported palladium catalysts in an aqueous solution of 2-propanol

    Science.gov (United States)

    Krasnov, A. I.; Latypova, A. R.; Lefedova, O. V.; Sharonov, N. Yu.

    2017-03-01

    The kinetics of the liquid-phase hydrogenation of 2-chloro-4-nitroaniline in an aqueous solution of 2-propanol over skeletal nickel and supported palladium catalysts is studied. The selectivity of the reaction with respect to 2-chloro-1,4-phenylenediamine is determined. It is found that samples of supported palladium catalysts differ with respect to the amount of the active component and the nature of the support. Some of their structural characteristics are provided.

  19. Densities, viscosities, refractive indices, and surface tensions for binary and ternary mixtures of 2-propanol, tetrahydropyran, and 2,2,4-trimethylpentane

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Y.-C. [Department of Applied Chemistry, Providence University, Shalu 43301, Taiwan (China); Tu, C.-H., E-mail: chtu@pu.edu.t [Department of Applied Chemistry, Providence University, Shalu 43301, Taiwan (China)

    2011-02-15

    Densities, viscosities, refractive indices, and surface tensions of the ternary system (2-propanol + tetrahydropyran + 2,2,4-trimethylpentane) at T = 303.15 K and its constituent binary systems (2-propanol + tetrahydropyran, 2-propanol + 2,2,4-trimethylpentane, and tetrahydropyran + 2,2,4-trimethylpentane) at T = (293.15, 303.15, 313.15, and 323.15) K were measured at atmospheric pressure. Densities were determined using a vibrating-tube densimeter. Viscosities were measured with an automatic microviscometer based on the rolling-ball principle. Refractive indexes were measured using a digital Abbe-type refractometer. Surface tensions were determined by the Wilhelmy-plate method. From these data, excess molar volumes, deviations in viscosity, deviations in refractive index, and deviations in surface tension were calculated. The results for the binary and ternary systems were fitted to the Redlich-Kister equation and the variable-degree polynomials in terms of compositions, respectively. The experimental and calculated quantities are used to study the nature of mixing behaviour between mixture components.

  20. Excess isentropic compressibility and speed of sound of the ternary mixture 2-propanol + diethyl ether + n-hexane and the constituent binary mixtures at 298.15 K

    Indian Academy of Sciences (India)

    Gokhan Sovaroglu; Ertunc Aral

    2006-02-01

    Speed of sound and densities of the ternary mixture 2-propanol + diethyl ether + n-hexane and also the binary mixtures 2-propanol + diethyl ether and 2-propanol + n-hexane have been measured at the entire composition range at 298.15 K. The excess isentropic compressibilities and the excess speed of the sound have been calculated from experimental densities and speed of sound. These excess properties of the binary mixtures were fitted to Redlich-Kister equation, while the Cibulka's equation was used to fit the values related to the values to the ternary system. These excess properties have been used to discuss the presence of significant interactions between the component molecules in the binary mixtures and also the ternary mixtures. Speed of sound of the binary mixtures and the ternary mixture have been compared with calculated values from free length theory (FLT), collision factor theory (CFT), Nomoto's relation (NR), Van Deal's ideal mixing relation (IMR) and Junjie's relation (JR). The results are used to compare the relative merits of these theories and relations in terms of the root mean square deviation relative (RMSDr).

  1. LIQUID-LIQUID EQUILIBRIA FOR MIXTURES OF WATER,DECANE and 1-ETHOXY-2-PROPANOL%1-乙氧基-2-丙醇/水/癸烷的液液平衡

    Institute of Scientific and Technical Information of China (English)

    陈瑶; 李任强; 田村和弘

    2003-01-01

    Experimental data of ternary liquid-liquid equilibria for mixtures of 1-ethoxy-2-propanol, water and decane were measured at 298.15K.Extended UNIQUAC model was empolyed to correlate those data. The extended UNIQUAC model successfully represented the thermodynamic properties for the ternary system of 1-ethoxy-2-propanol, water and decane. These experimental results are useful for designing the separation and extraction process.

  2. A Computational Study on the Mechanism for the K_2CO_3-catalyzed Reaction of Carbon Dioxide and 1-Chlo-2-propanol

    Institute of Scientific and Technical Information of China (English)

    张福兰; 万邦江; 黄辉胜

    2012-01-01

    The microcosmic reaction mechanism of K2CO3-catalyzed 1-chlo-2-propanol and carbon dioxide has been investigated by density functional theory(DFT) at the GGA/PW91/DNP level.We optimize the geometric configurations of reactants,intermediates,transition states,and products.The energy analysis calculation approves the authenticity of intermediates and transition states.According to our calculations,four feasible reaction pathways are found.The main pathway of the reaction is ReA → IMA1 → TSA1 → IMA2 → IMA5 → TSA5 → P.Besides,we also in-vestigate the reaction mechanism of 1-chlo-2-propanol and carbon dioxide without K2CO3-catalyzation by the same theory and level.The computational results indicate that the activation barrier with K2CO3-catalyzed is smaller than the activation barrier without K2CO3-catalyzed.That is to say,K2CO3 can promote the reaction to give the product in a high yield,which is in agreement with the experimental results.

  3. Equilibrium solubility of CO{sub 2} in aqueous solutions of 1-amino-2-propanol as function of concentration, temperature, and pressure

    Energy Technology Data Exchange (ETDEWEB)

    Rebolledo-Morales, Miguel Angel; Rebolledo-Libreros, Maria Esther [Instituto Mexicano del Petroleo, Direccion de Investigacion y Posgrado, Programa de Ingenieria Molecular, Area de Investigacion de Termofisica, Eje Central Lazaro Cardenas Norte 152, 07730 Mexico, D.F. (Mexico); Trejo, Arturo, E-mail: atrejo@imp.m [Instituto Mexicano del Petroleo, Direccion de Investigacion y Posgrado, Programa de Ingenieria Molecular, Area de Investigacion de Termofisica, Eje Central Lazaro Cardenas Norte 152, 07730 Mexico, D.F. (Mexico)

    2011-05-15

    Research highlights: Gas solubility of CO{sub 2} in aqueous solutions of 1-amino-2-propanol was measured. Solubility increases as pressure and concentration of 1-amino-2-propanol increase. The Kent-Eisenberg model was used to correlate all the experimental results. Aqueous solutions of MIPA are an excellent alternative to use in gas purification. - Abstract: Using a dynamic method with recirculation of the vapour phase, experimental values for the gas solubility of carbon dioxide in aqueous solutions of 1-amino-2-propanol (MIPA) were measured at T = (313.15 and 393.15) K, over the pressure range of (0.2 to 2436.4) kPa. The concentrations of the studied aqueous MIPA solutions were (0.20, 0.30, 0.40, and 0.50) mass fraction. The results of gas solubility are given as the partial pressure of CO{sub 2}, p{sub CO{sub 2}}, against its mole ratio, {alpha}{sub CO{sub 2}} (mol CO{sub 2} {center_dot} mol{sup -1} MIPA), and its mole fraction, x{sub CO{sub 2}}. It is observed that the solubility of CO{sub 2} increases as the concentration of MIPA in solution increases, at a given temperature throughout the pressure range considered; also the solubility values increase, under constant temperature, as the pressure increases in the studied concentration range of MIPA. The physicochemical model of Kent and Eisenberg was used to correlate simultaneously all the experimental results of the solubility of CO{sub 2} in the studied aqueous solutions of MIPA. The model correlates satisfactorily the experimental results. The deviation for pressure was 96.9 kPa using 62 experimental solubility points. The solubility results of carbon dioxide presented in this work are compared with those reported in the literature for aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), diisopropanolamine (DIPA), and N-methyldiethanolamine (MDEA) and it is possible to conclude that the aqueous solutions of MIPA are an excellent alternative to use in gas purification processes, since the

  4. Ternary liquid-liquid equilibria of dimethyl carbonate + 2-propanol + water system at 303.15 and 313.15 K

    Science.gov (United States)

    Ginting, Rizqy Romadhona; Mustain, Asalil; Tetrisyanda, Rizki; Gunardi, Ignatius; Wibawa, Gede

    2015-12-01

    In this work, liquid-liquid equilibria data of dimethyl carbonate (DMC) + 2-propanol + water system were accurately determined at 303.15 and 313.15 K using stirred and jacketed equilibrium cell under atmospheric pressure. The reliabilities of the experimental data were confirmed using Bachman-Brown correlation giving r-squared value of 0.9993 and 0.9983 at 303.15 and 313.15 K, respectively. Experimental data obtained in this work exhibit Treybal's Type I ternary phase behavior. The selectivity and distribution coefficient of DMC increases with addition of DMC concentration in the organic phase. On the other hand, the effect of temperature to phase boundary was found to be not significant. The data were correlated well using the Non-Random Two Liquid (NRTL) and Universal Quasi-Chemical (UNIQUAC) activity coefficient models with root-mean-square deviation of 1.5% and 1.3%, respectively.

  5. Catalytic Oxidative Conversion from Naphthol to 2-Hydroxy-1, 4-naphthoquinone over Iron Porphyrin Catalysts by Molecular Oxygen in an Alkaline 2-Propanol Solution

    Institute of Scientific and Technical Information of China (English)

    YANG Ke-er; TONG Shan-ling; YAN Yan; KANG En-hua; XIAO Feng-shou; LI Qing; CHANG Xin; FANG Chi-guang

    2005-01-01

    In an alkaline 2-propanol solution with 5,10,15,20-tetra(4-methoxyl phenyl) porphyrin iron chloride(TOMPPFeCl) as a catalyst and oxygen as a cheap green oxidant, 2-naphthol was conversed to 2-hydroxy-1,4-naphthoquinone(HNQ) with a yield of 62.17% and a selectivity of 100%, and the conversion number of TMOPPFeCl catalyst was 8.32/min. The catalytic oxidation products were characterized by means of UV-Vis, IR, GC-MS, 1H NMR and melting point determination. In this catalytic oxidation, the catalytic activity of TMOPPFeCl was researched in detail and the reacting conditions were optimized. A possible reaction mechanism is summarized based on in situ EPR determination.

  6. Synthesis, radiolabeling and in vivo evaluation of [(11)C](R)-1-[4-[2-(4-methoxyphenyl)phenyl]piperazin-1-yl]-3-(2-pyrazinyloxy)-2-propanol, a potential PET radioligand for the 5-HT(7) receptor

    DEFF Research Database (Denmark)

    Hansen, Hanne D; Lacivita, Enza; Di Pilato, Pantaleo;

    2014-01-01

    In the search for a novel serotonin 7 (5-HT7) receptor PET radioligand we synthesized and evaluated a new series of biphenylpiperazine derivatives in vitro. Among the studied compounds, (R)-1-[4-[2-(4-methoxyphenyl)phenyl]piperazin-1-yl]-3-(2-pyrazinyloxy)-2-propanol ((R)-16), showed the best com...

  7. Catalytic hydrodechlorination of trichloroethylene in a novel NaOH/2-propanol/methanol/water system on ceria-supported Pd and Rh catalysts.

    Science.gov (United States)

    Cobo, Martha; Becerra, Jorge; Castelblanco, Miguel; Cifuentes, Bernay; Conesa, Juan A

    2015-08-01

    The catalytic hydrodechlorination (HDC) of high concentrations of trichloroethylene (TCE) (4.9 mol%, 11.6 vol%) was studied over 1%Pd, 1%Rh and 0.5%Pd-0.5%Rh catalysts supported on CeO2 under conditions of room temperature and pressure. For this, a one-phase system of NaOH/2-propanol/methanol/water was designed with molar percentages of 13.2/17.5/36.9/27.6, respectively. In this system, the alcohols delivered the hydrogen required for the reaction through in-situ dehydrogenation reactions. PdRh/CeO2 was the most active catalyst for the degradation of TCE among the evaluated materials, degrading 85% of the trichloroethylene, with alcohol dehydrogenation rates of 89% for 2-propanol and 83% for methanol after 1 h of reaction. Fresh and used catalysts were characterized by Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), and Thermogravimetric analysis (TGA). These results showed important differences of the active phase in each catalyst sample. Rh/CeO2 had particle sizes smaller than 1 nm and the active metal was partially oxidized (Rh(0)/Rh(+δ) ratio of 0.43). This configuration showed to be suitable for alcohols dehydrogenation. On the contrary, Pd/CeO2 showed a Pd completed oxidized and with a mean particle size of 1.7 nm, which seemed to be unfavorable for both, alcohols dehydrogenation and TCE HDC. On PdRh/CeO2, active metals presented a mean particle size of 2.7 nm and more reduced metallic species, with ratios of Rh(0)/Rh(+δ) = 0.67 and Pd(0)/Pd(+δ) = 0.28, which showed to be suitable features for the TCE HDC. On the other hand, TGA results suggested some deposition of NaCl residues over the catalyst surfaces. Thus, the new reaction system using PdRh/CeO2 allowed for the degradation of high concentrations of the chlorinated compound by using in situ hydrogen liquid donors in a reaction at room temperature and pressure.

  8. Decomposition mechanism of 2-propanol and 1,1,1-trifluoro-2-propanol on Ni(100) surface%2-丙醇和1,1,1-三氟-2-丙醇在Ni(100)表面的裂解机理

    Institute of Scientific and Technical Information of China (English)

    张福兰

    2016-01-01

    本文研究了2-丙醇和1,1,1-三氟-2-丙醇在Ni(100)表面解离的可能微观反应机理,使用完全线性同步和二次同步变换( complete LST/QST)方法确定解离反应的过渡态.采用基于第一性原理的密度泛函理论与周期平板模型相结合的方法,优化了2-丙醇和1,1,1-三氟-2-丙醇裂解反应过程各物种在Ni(100)表面的top,hollow和bridge位的吸附模型,计算了能量,并对布局电荷进行了分析,得到了各物种的有利吸附位.结果表明:2-丙醇和1,1,1-三氟-2-丙醇在Ni(100)表面都存在β-H和γ-H两个平行竞争的解离过程,其中2-丙醇在Ni(100)表面β-H解离的速控步骤活化能为64.7 kJ· mol -1猯,而γ-H 解离速控步骤活化能为233.1 kJ · mol-1猯,故β-H 解离过程占优势,主要产物是CH3COCH3;相反,1,1,1-三氟-2-丙醇在Ni(100)表面β-H解离的速控步骤活化能为257.1 kJ· mol-1猯,而γ-H解离速控步骤活化能为148.1 kJ · mol -1猯,故γ-H解离过程占优势,主要产物是CF3 CH=CH2.由此说明,电负性更大的氟原子取代2-丙醇中的氢原子之后,2-丙醇在Ni表面的解离机理发生了改变.理论预测结果与实验结论一致.%The possible decomposition mechanism of 2 -propanol and 1,1,1 -trifluoro -2 -propanol on Ni (100) surface was investigated utilizing the first -principles density functional theory (DFT) and self-consist-ent periodic calculation.The transition states were testified by using the complete Linear Synchronous Transit and the Quadratic Synchronous Transit ( LST/QST) methods.All the species involved in this process on three possi-ble adsorption sites (top, hollow, and bridge) on Ni(100) surface were fully optimized to obtain their equilibri-um geometries.The corresponding adsorption energies and Mullikan charge analysis of these species were predic -ted and

  9. Design of Composite Photocatalyst of TiO2 and Y-Zeolite for Degradation of 2-Propanol in the Gas Phase under UV and Visible Light Irradiation

    Directory of Open Access Journals (Sweden)

    Takashi Kamegawa

    2014-10-01

    Full Text Available Hydrophobic Y-zeolite (SiO2/Al2O3 = 810 and TiO2 composite photocatalysts were designed by using two different types of TiO2 precursors, i.e., titanium ammonium oxalate and ammonium hexafluorotitanate. The porous structure, surface property and state of TiO2 were investigated by various characterization techniques. By using an ammonium hexafluorotitanate as a precursor, hydrophobic modification of the Y-zeolite surface and realizing visible light sensitivity was successfully achieved at the same time after calcination at 773 K in the air. The prepared sample still maintained the porous structure of Y-zeolite and a large surface area. Highly crystalline anatase TiO2 was also formed on the Y-zeolite surface by the role of fluorine in the precursor. The usages of ammonium hexafluorotitanate were effective for the improvement of the photocatalytic performance of the composite in the degradation of 2-propanol in the gas phase under UV and visible light (λ > 420 nm irradiation.

  10. Studies of mixing properties of binary systems of 2-propanol with hexadecane and squalane at T = (298.15, 303.15, and 308.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, Gyan P. [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India)], E-mail: gyan.dubey@rediffmail.com; Sharma, Monika [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India)], E-mail: sharmamonika20@rediffmail.com

    2009-01-15

    The present paper reports the experimental data for density, {rho}, viscosity, {eta}, and speeds of sound, u for the binary mixtures of 2-propanol, (CH{sub 3}){sub 2}CHOH with hexadecane, C{sub 16}H{sub 34} over the miscibility region (0 < x{sub 1} < 1) and with squalane (2,4,6,10,15,19,23-hexametyltetracosane), C{sub 30}H{sub 62} over the miscibility region (0 < x{sub 1} < 0.6) at T = (298.15, 303.15, and 308.15) K. The experimental data have been used to calculate various parameters like excess molar volumes, V{sub m}{sup E}, viscosity deviations, {delta}{eta}, excess molar isentropic compressibility, K{sub S,m}{sup E}, and deviations in speed of sound, u{sup D}, from their ideal values u{sup id}. These excess parameters and deviations are used to interpret the molecular interactions in these binary mixtures.

  11. Structure–acidity correlation of supported tungsten(VI)-oxo-species: FT-IR and TPD studies of adsorbed pyridine and catalytic decomposition of 2-propanol

    Energy Technology Data Exchange (ETDEWEB)

    Zaki, M.I., E-mail: mizaki@mu.edu.eg; Mekhemer, G.A.H.; Fouad, N.E.; Rabee, A.I.M.

    2014-07-01

    The amount of 10 wt%-WO{sub 3} was supported on alumina, titania or silica by impregnation with aqueous solution of ammonium paratungstate and subsequent calcination at 500 °C for 10 h. Tungstate-related chemical and physical changes in the calcination products were resolved by ex-situ infrared (IR) spectroscopy. Nature of exposed surface acid sites were probed by in-situ IR spectroscopy of adsorbed pyridine (Py) molecules at room temperature (RT). The relative strength of the acid sites thus probed was gauged by combining results of temperature-programmed desorption (TPD) measurements of the RT-adsorbed Py with those communicated by in-situ IR spectra of residual Py on the surface after a brief thermoevacuation at high temperatures (100–300 °C). Reactivity of the surface acid sites was tested toward 2-propanal catalytic decomposition, and observed by in-situ IR gas phase spectra. Results obtained were correlated with predominant structures assumed by the supported tungstate species. Accordingly, polymerization of the supported tungstate into 2-/3-dimensional structures, was found to be relatively most advanced on favorable locations of titania surfaces as compared to the case on alumina or silica surfaces. Consequently, the Lewis acidity was strengthened, and strong Bronsted acidity was evolved, leading to a 2-propanol dehydration catalyst (tungstate/titania) of optimal activity and selectivity. Strong tungstate/support interfacial interactions were found to hamper the formation of the strongly acidic and catalytically active polymeric structures of the supported tungstate (i.e., the case on alumina or silica).

  12. (Vapour + liquid) equilibrium of binary mixtures (1,3-dioxolane or 1,4-dioxane + 2-methyl-1-propanol or 2-methyl-2-propanol) at isobaric conditions[(Vapour+liquid) equilibrium; Cyclic ethers; Butanols; ASOG; UNIFAC

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, Antonio; Lafuente, Carlos; Minones, Jose; Kragl, Udo; Royo, Felix M. E-mail: femer@posta.unizar.es

    2004-02-01

    Isobaric (vapour + liquid) equilibrium of (1,3-dioxolane or 1,4-dioxane + 2-methyl-1-propanol or 2-methyl-2-propanol) at 40.0 kPa and 101.3 kPa has been studied with a dynamic recirculating still. The experimental VLE data are thermodynamically consistent. From these data, activity coefficients were calculated and correlated with the Margules, van Laar, Wilson, NRTL and UNIQUAC equations. The VLE results have been compared with the predictions by the UNIFAC and ASOG methods.

  13. 正丙醇和异丙醇的紫外光解动力学%Ultraviolet Photodissociation Dynamics of 1-Propanol and 2-Propanol by High-n Rydberg-Atom Time-of-flight(HRTOF) Technique

    Institute of Scientific and Technical Information of China (English)

    周卫东; 张劲松

    2002-01-01

    利用高里德堡态氢原子飞行时间(HRTOF)探测技术,研究了正丙醇和异丙醇的紫外光解动力学过程.在193.3 nm光辐射下,O-H键快速断裂过程构成主要的氢原子生成通道.伴随O-H键的碎裂,相当大的一部分能量转换成氢原子及其相应碎片的平动能(正丙醇〈fv〉=0.76; 异丙醇〈fv〉=0.78).氢原子碎片具有各向异性的角度分布;其角分布异向因子β分别为-0.79(正丙醇)和-0.77(异丙醇).研究结果表明,吸收1个193.3 nm光子后,丙醇分子跃迁到一个寿命很短的电子激发态;沿着O-H反应坐标,该激发态势能面是排斥的,因而O-H键快速断裂.此外,还得到了丙醇的O-H键离解能: (432±2)kJ/mol(正丙醇)和(433±2)kJ/mol(异丙醇).%193.3 nm photodissociation dynamics of jet-cooled 1-propanol and 2-propanol has been examined by using high-n Rydberg-atom time-of-flight (HRTOF) technique. Isotope labeling study indicates that O-H bond fission is the primary H-atom production channel. Center-of-mass (CM) product translational energy release of this channel is large, with 〈fT〉= 0.76 for H+1-propoxy and 0.78 for H+2-propoxy. Maximum CM translational energy release yields an upper limit of the O-H bond dissociation energy: (432±2)kJ/mol in 1-propanol and (433±2)kJ/mol in 2-propanol. H-atom product angular distribution is anisotropic (with β≈-0.79 for 1-propanol and -0.77 for 2-propanol), indicating a short excited-state lifetime. The 193.3 nm H-atom dissociation of both 1-propanol and 2-propanol is prompt and occurs on a repulsive excited-state potential energy surface.

  14. Determination and modelling of osmotic coefficients and vapour pressures of binary systems 1- and 2-propanol with C{sub n}MimNTf{sub 2} ionic liquids (n = 2, 3, and 4) at T = 323.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Calvar, Noelia [LSRE - Laboratory of Separation and Reaction Engineering, Associate Laboratory, LSRE/LCM, Department of Chemical Engineering, Faculty of Engineering, Rua Dr. Roberto Frias s/n, Porto 4200-465 (Portugal); Gomez, Elena; Dominguez, Angeles [Advanced Separation Processes Group, Department of Chemical Engineering, University of Vigo, 36310 Vigo (Spain); Macedo, Eugenia A., E-mail: eamacedo@fe.up.pt [LSRE - Laboratory of Separation and Reaction Engineering, Associate Laboratory, LSRE/LCM, Department of Chemical Engineering, Faculty of Engineering, Rua Dr. Roberto Frias s/n, Porto 4200-465 (Portugal)

    2011-08-15

    Highlights: > Osmotic coefficients of 1- and 2-propanol with C{sub n}MimNTf{sub 2} (n = 2, 3, and 4) are determined. > Experimental data were correlated with extended Pitzer model of Archer and MNRTL. > Mean molal activity coefficients and excess Gibbs free energies were calculated. > Effect of the anion is studied comparing these results with literature. - Abstract: The osmotic and activity coefficients and vapour pressures of binary mixtures containing 1-propanol, or 2-propanol and imidazolium-based ionic liquids with bis(trifluoromethylsulfonyl)imide as anion (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, C{sub 2}MimNTf{sub 2}, 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide, C{sub 3}MimNTf{sub 2}, and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, C{sub 4}MimNTf{sub 2}) were determined at T = 323.15 K using the vapour pressure osmometry technique. The experimental osmotic coefficients were correlated using the extended Pitzer model modified by Archer and the MNRTL model, obtaining standard deviations lower than 0.033 and 0.064, respectively. The mean molal activity coefficients and the excess Gibbs free energy for the mixtures studied were calculated from the parameters of the extended Pitzer model modified by Archer. Besides the effect of the alkyl-chain of the cation, the effect of the anion can be assessed comparing the experimental results with those previously obtained for imidazolium ionic liquids with sulphate anions.

  15. Application of the margin of exposure (MoE) approach to substances in food that are genotoxic and carcinogenic: example: (CAS No. 96-23-1) 1,3-dichloro-2-propanol (DCP).

    Science.gov (United States)

    Williams, Gary; Leblanc, Jean-Charles; Setzer, R Woodrow

    2010-01-01

    1,3-Dichloro-2-propanol (DCP) is formed in foods under a variety of conditions. It was positive in a variety of in vitro genotoxicity tests, but was negative in two in vivo studies. DCP produced neoplasms at several sites in rats. Kidney tumours in male rats were selected as the critical tumour type. Dose-response modelling of the data for DCP gave a BMDL(10) for combined kidney carcinomas and adenomas in male rats of 9.62 mg/kg-body weight (bw)/day. The exposure of humans was estimated at an average of 0.00009 mg/kg-bw/day and a high exposure of 0.000136 mg/kg-bw/day. The MOEs for these exposures were 100,000 and 70,000, respectively.

  16. Synthesis and preliminary evaluation of (R,S)-1-[2-((carbamoyl-4-hydroxy)phenoxy)-ethylamino]-3-[4-(1-[11C]-met hyl-4-trifluoromethyl-2-imidazolyl)phenoxy]-2-propanol ([11C]CGP 20712A) as a selective beta 1-adrenoceptor ligand for PET

    NARCIS (Netherlands)

    Elsinga, P H; Van Waarde, A; Visser, Gerben; Vaalburg, W

    1994-01-01

    The most selective beta 1-adrenoceptor ligand known at this moment is (S)-1-[2-((carbamoyl-4-hydroxy) phenoxy)ethylamino]-3-[4-(1-methyl-4-trifluoromethyl-2-imidazolyl) phenoxy]-2-propanol (CGP 26505), the S-isomer of CGP 20712A. We prepared the racemic 11C analogue by methylation with [11C]CH3I of

  17. 1-丙醇和2-丙醇真空紫外光电离质谱研究%A Vacu um Ultraviolet Photoionization Mass Spectrometric Study of 1-Propanol and 2-Propanol

    Institute of Scientific and Technical Information of China (English)

    卫立夏; 杨斌; 王晶; 黄超群; 盛六四; 齐飞

    2006-01-01

    The photoionization and dissociative photoionization of 1-propanol and 2-propanols have been studied at the photon energy range of 9.84~11.80 eV. Photoionization efficiency spectra for ions CH3CH2CH2OH+, CH3CH2CHOH+,CH2CH2OH+, CH3CH2CH2+, CH3CH=CH+2, CH2OH+ from 1-propanol, and CH3CH(OH)CH3+, CH3C(OH)CH3+, CH3CHOH+,CH2=CHOH+, CH3CHCH3+, CH3CH=CH2+ from 2-propanol have been measured. In addition, the energetics of the dissociative photoionization has been examined by ab initio Gaussion-3(G3) calculations. The computational results are useful in establishing the dissociation channels near the ionization thresholds. With the help of G3 results, the dissociation channels for formation of the fragment ions CH3CH2CHOH+, CH2CH2OH+, CH3CH2CH2+, CH3CH=CH2+,CH2OH+ from 1-propanol, and CH3C(OH)CH3+, CH3CHOH+, CH2=CHOH+, CH3CHCH3+, CH3CH=CH2+ from 2-propanol have been established. The G3 results are in excellent agreement with the experimental data.%研究了9.84~11.80 eV光子能量范围内1-丙醇和2-丙醇的光电离和离解光电离现象,测量了1-丙醇离解光电离产生的碎片离子CH3CH2CH2OH+、CH3CH2CHOH+、CH2CH2OH+、CH3CH2CH2+、CH3CH=CH2+和CH2OH+及2-丙醇离解光电离产生的碎片离子CH3CH(OH)CH3+、CH3C(OH)CH3+、CH3CHOH+、CH2=CHOH+、CH3CHCH3+和CH3CH=CH2+的光电离效率谱,得到了这些离子的出现势.结合从头算理论计算,给出了1-丙醇的碎片离子CH3CH2CHOH+、CH2CH2OH+、CH3CH2CH2+、CH3CH=CH2+、CH2OH+和2-丙醇的碎片离子CH3C(OH)CH3+、CH3CHOH+、CH2=CHOH+、CH3CHCH+3、CH3CH=CH2+等的解离通道和解离能.理论计算结果与实验结果符合得很好.

  18. 正丙醇和异丙醇对水溶液中牛血清白蛋白的构象及其荧光光谱的影响%Effects of 1-Propanol and 2-Propanol on the Conformation and Fluorescence Spectra of Bovine Serum Albumin in Aqueous Solutions

    Institute of Scientific and Technical Information of China (English)

    马林; 刘东群; 杨华; 童张法

    2008-01-01

      A combination of emission fluorescence spectroscopy (λex=280 nm,295 nm) and synchronous fluorescence spectroscopy (Δλ=15 nm、60 nm) with static light scattering measurement was used to investigate the effects of 1-propanol and 2-propanol on the conformation and fluorescence spectroscopy of Bovine Serum Albumin (BSA) in BSA-1-propanol-water and BSA-2-propanol-water systems. The results showed that 1-propanol and 2-propanol generally decreased, however at dilute solutions slightly increased, the stability of the structure of protein. And it was found that 1-propanol and 2-propanol were week protein denaturants, so that the fluorescence intensity of BSA was controlled by the mixing state of the mixtures at high 1-propanol and 2-propanol concentration.%  通过测定BSA-正丙醇-水和BSA-异丙醇-水体系中BSA的发射荧光(λex=280 nm、295 nm)和同步荧光(△λ=15 nm、60 nm),结合静态光散射技术,探索正丙醇和异丙醇对水溶液中蛋白质的构象和荧光光谱的影响。结果表明,正丙醇和异丙醇使蛋白质发生部分解折叠现象,但是,低浓度的正丙醇和异丙醇水溶液能轻微增强蛋白质的结构稳定性。总体上,正丙醇和异丙醇是弱的蛋白质变性剂,在浓度较高的体系中,体系的混合状态的变化对 BSA 的荧光强度的变化起主导作用。

  19. Chemical-physical properties of spinel CoMn2O4 nano-powders and catalytic activity in the 2-propanol and toluene combustion: Effect of the preparation method.

    Science.gov (United States)

    Hosseini, Seyed Ali; Salari, Dariush; Niaei, Aligholi; Deganello, Francesca; Pantaleo, Giuseppe; Hojati, Pejman

    2011-01-01

    Spinel-type CoMn(2)O(4)nano-powders are prepared using sol-gel auto combustion (SGC) and co-precipitation (CP) methods and their catalytic activities are evaluated in combustion of 2-propanol and toluene. The chemical-physical properties of the oxides are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N(2)-adsorption-desorption, temperature programmed reduction (TPR) and scanning electron microscopy (SEM). After calcination at 700°C, CoMn(2)O(4)-SGC shows higher amounts of the normal-type spinel phase and is more crystalline than CoMn(2)O(4)-CP. Higher calcination temperatures (850°C) do not affect very much the weight percentage of the normal-type spinel phase; although the crystal size slightly increased. The TPR analysis evidences a large number of Mn(3+) cations in CoMn(2)O(4)-SGC compared to CoMn(2)O(4)-CP. This difference, together with the higher surface area, could justify the higher activity of CoMn(2)O(4)-SGC in both the investigated reactions.

  20. Synthesis and Characterization of Cobalt(III), Nickel(II) and Copper(II) Mononuclear Complexes with the Ligand 1,3-bis[(2-aminoethyl)amino]-2-propanol and Their Catalase-Like Activity.

    Science.gov (United States)

    Pires, Bianca M; Silva, Daniel M; Visentin, Lorenzo C; Rodrigues, Bernardo L; Carvalho, Nakédia M F; Faria, Roberto B

    2015-01-01

    In this work, we present the synthesis and characterization of two new mononuclear complexes with the ligand 1,3-bis[(2-aminoethyl)amino]-2-propanol (HL), [Co(L)(H2O)](ClO4)2 (1), [Ni(HL)](ClO4)2 (2), as well as the known complex [Cu(HL)](ClO4)2 (3) for comparison. Their abilities to catalyze the dismutation of H2O2 and the oxidation of cyclohexane were investigated. The complexes were characterized by X-ray diffraction, elemental analysis, electronic and infrared spectroscopy, cyclic voltammetry, electrospray ionization mass spectrometry (ESI-MS) and conductivity measurements. The X-ray structures showed that the nickel (2) and copper (3) complexes are tetracoordinated, with the metal ion bound to the nitrogen atoms of the ligand. On the other hand, the cobalt complex (1) is hexacoordinated, possessing additional bonds to the alkoxo group of the ligand and to a water molecule. Neither of the complexes was able to catalyze the oxidation of cyclohexane, but all of them exhibited catalase-like activity, following Michaelis-Menten kinetics, which suggest resemblance with the catalase natural enzymes. The catalytic activity followed the order: [Ni(HL)](ClO4)2 (2) > [Cu(HL)](ClO4)2 (3) > [Co(L)(H2O)](ClO4)2 (1). As far as we know, this is the first description of a nickel complex presenting a significant catalase-like activity.

  1. 双回流动态累积间歇精馏分离正丙醇-异丙醇物系过渡馏分的研究%Slop Cut in Separation of 1-Propanol from 2-Propanol by Dynamic-Accumulation Batch Distillation with Double-Reflux

    Institute of Scientific and Technical Information of China (English)

    陈立峰; 张兵; 李文秀; 于巍; 白鹏

    2011-01-01

    在双回流动态累积间歇精馏实验装置中,以正丙醇-异丙醇为物系进行了间歇精馏实验,考察了操作时间对过渡馏分采出段塔顶馏出液中正丙醇和异丙醇的含量及塔顶温度、塔釜液正丙醇含量及塔釜温度的影响.实验结果表明,原料中异丙醇质量分数别为30%,50%,70%时,对应的过渡馏分采出段操作时间分别为38,46,57 min;原料中异丙醇的含量越低,正丙醇回收率越高.在原料加入量为1L、加热功率为150 W、原料中异丙醇质量分数为30%的条件下,回收得到的正丙醇质量分数可达到86.66%,此时正丙醇的回收率为67.57%,过渡馏分的量最少,操作时间最短.%Batch distillation of 1 -propanol-2-propanol binary system was carried out in a set of dynamic-accumulation batch distillation apparatus with double- reflux. The effects of operation time on mass fractions of 1 -propanol and 2-propanol in the column top distillate, the column top temperature, mass fraction of 1 -propanol in the column bottoms and the column bottom temperature in the slop cut stage were investigated. The experimental results indicated that, when mass fraction of 2-propanol in the feed was 30% , 50% and 70% , the operation time of the corresponding slop cut stage was 38, 46 and 57 min. The 1-propanol yield increased while the mass fraction of 2-propanol in the feed decreased. Under the conditions of feed 1000 mL, heating power 150W and mass fraction of 2-propanol in the feed 30% , mass fraction of 1-propanol in the products was 86.66% and its yield was 67.57% , and the slop cut mass reached the minimum and the operation time of the slop cut stage was the shortest.

  2. Effects of Additives on Catalytic Oxidation of 1-Methoxy-2-Propanol to Methoxyacetone%添加物对1-甲氧基-2-丙醇催化氧化制甲氧基丙酮反应的影响

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The system WⅥ-H2O2 has good selectivity for methoxyacetone in oxidation of 1-methoxy-2-propanol. The effects of acid and base additives on selectivit y for methoxyacetone were studied. The results showed that the acid additive, i.e. NaHSO4, was favorable to Na2WO4-H2O2 system, while the base ad ditive NEt3 was favorable to other tungsten compounds. A 71.2% of yield of me thoxyacetone with 98.9% of selectivity for methoxyacetone was obtained in Na2 WO4-H2O2-NaHSO4-MeCOMe oxidation system.

  3. Henry's law constants and infinite dilution activity coefficients of cis-2-butene, dimethylether, chloroethane, and 1,1-difluoroethane in methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol

    Energy Technology Data Exchange (ETDEWEB)

    Miyano, Yoshimori [Department of Chemistry and Bioscience, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajimacho, Kurashiki 712-8505 (Japan)]. E-mail: miyano@chem.kusa.ac.jp; Kobashi, Takahiro [Department of Chemistry and Bioscience, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajimacho, Kurashiki 712-8505 (Japan); Shinjo, Hiroshi [Department of Chemistry and Bioscience, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajimacho, Kurashiki 712-8505 (Japan); Kumada, Shinya [Department of Chemistry and Bioscience, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajimacho, Kurashiki 712-8505 (Japan); Watanabe, Yusuke [Department of Chemistry and Bioscience, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajimacho, Kurashiki 712-8505 (Japan); Niya, Wataru [Department of Chemistry and Bioscience, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajimacho, Kurashiki 712-8505 (Japan); Tateishi, Yoko [Department of Chemistry and Bioscience, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajimacho, Kurashiki 712-8505 (Japan)

    2006-06-15

    Henry's law constants and infinite dilution activity coefficients of cis-2-butene, dimethylether, chloroethane, and 1,1-difluoroethane in methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol in the temperature range of 250 K to 330 K were measured by a gas stripping method and partial molar excess enthalpies were calculated from the activity coefficients. A rigorous formula for evaluating the Henry's law constants from the gas stripping measurements was used for the data reduction of these highly volatile mixtures. The uncertainty is about 2% for the Henry's law constants and 3% for the estimated infinite dilution activity coefficients. In the evaluation of the infinite dilution activity coefficients, the nonideality of the solute such as the fugacity coefficient and Poynting correction factor cannot be neglected, especially at higher temperatures. The estimated uncertainty of the infinite dilution activity coefficients includes 1% for nonideality.

  4. Kraftig eksplosion efter sammenblanding af salpetersyre og 2-propanol

    DEFF Research Database (Denmark)

    Hedlund, Frank Huess

    2015-01-01

    Det er velkendt, at koncentreret salpetersyre reagerer med mange stoffer, ofte voldsomt, med varmeudvikling og frigivelse af giftige brune nitrøse gasser. Kun få er klar over, at det under særlige omstændigheder ved blanding med isopropylalkohol, eller andre alkoholer, kan udvikle raketbrændstof....

  5. Support vector classification for structure-activity-relationship of 1-(1H-1,2,4-triazole-1-yl)-2-(2,4-difluorophenyl)-3-substituted-2-propanols%支持向量分类算法用于1-(1H-1,2,4-三唑-1-基)-2-(2,4-二氟苯基)-3-取代-2-丙醇化合物的构效关系研究

    Institute of Scientific and Technical Information of China (English)

    纪晓波; 陆文聪; 蔡煜东; 陈念贻

    2007-01-01

    The support vector classification (SVC) was employed to make a model for classification of antifungal activities of 1-(1H-1,2,4-triazole-1-yl)-2-(2,4-difluorophenyl)-3-substituted-2-propanols triazole derivatives. The compounds with high antifungal activities and those with low antifungal activities were compared on the basis of the following molecular descriptors: net atomic charge on the atom N connecting with R, dipole moment and heat of formation. By using the SVC, a mathematical model was constructed, which can predict the antifungal activities of the triazole derivatives, with an accuracy of 91% on the basis of the leave-one-out cross-validation (LOOCV) test. The results indicate that the performance of the SVC model can exceed that of the principal component analysis (PCA) and K-Nearest Neighbor (KNN) models for this real world data set.

  6. Interface between platinum(111) and liquid isopropanol (2-propanol): a model for molecular dynamics studies.

    Science.gov (United States)

    Tarmyshov, Konstantin B; Müller-Plathe, Florian

    2007-02-21

    A molecular dynamics model and its parametrization procedure are devised and used to study adsorption of isopropanol on platinum(111) (Pt(111)) surface in unsaturated and oversaturated coverages regimes. Static and dynamic properties of the interface between Pt(111) and liquid isopropanol are also investigated. The magnitude of the adsorption energy at unsaturated level increases at higher coverages. At the oversaturated coverage (multilayer adsorption) the adsorption energy reduces, which coincides with findings by Panja et al. in their temperature-programed desorption experiment [Surf. Sci. 395, 248 (1998)]. The density analysis showed a strong packing of molecules at the interface followed by a depletion layer and then by an oscillating density profile up to 3 nm. The distribution of individual atom types showed that the first adsorbed layer forms a hydrophobic methyl "brush." This brush then determines the distributions further from the surface. In the second layer methyl and methine groups are closer to the surface and followed by the hydroxyl groups; the third layer has exactly the inverted distribution. The alternating pattern extends up to about 2 nm from the surface. The orientational structure of molecules as a function of distance of molecules is determined by the atom distribution and surprisingly does not depend on the electrostatic or chemical interactions of isopropanol with the metal surface. However, possible formation of hydrogen bonds in the first layer is notably influenced by these interactions. The surface-adsorbate interactions influence the mobility of isopropanol molecules only in the first layer. Mobility in the higher layers is independent of these interactions.

  7. 75 FR 43076 - 2-Propanol, 1,1′,1′′-nitrilotris-; Exemption from the Requirement of a Tolerance

    Science.gov (United States)

    2010-07-23

    ... Hearing Clerk on or before September 21, 2010. Addresses for mail and hand delivery of objections and... surface disinfection on walls, floors, tables). TIPA may be used in inert ingredients in products that are... handler exposure from indoor hand wiping with a high end post application dermal exposure from...

  8. Hydrogen transfer reaction of cyclohexanone with 2-propanol catalysed by CeO2-ZnO materials: Promoting effect of ceria

    Indian Academy of Sciences (India)

    Braja Gopal Mishra; G Ranga Rao; B Poongodi

    2003-10-01

    Ce-Zn-O mixed oxides were prepared by amorphous citrate process and decomposition of the corresponding acetate precursors. The resulting materials were characterised by TGA, XRD, UV-Vis-DRS, EPR, SEM and surface area measurements. XRD and DRS results indicated fine dispersion of the ceria component in the ZnO matrix. EPR results clearly indicate the presence of oxygen vacancy and defect centres in the composite oxide. Addition of CeO2 to ZnO produced mixed oxides of high surface area compared to the pure ZnO. Hydrogen transfer reaction was carried out on these catalytic materials to investigate the effect of rare earth oxide on the activity of ZnO. Addition of ceria into zinc oxide was found to increase the catalytic activity for hydrogen transfer reaction. The catalytic activity also depended on the method of preparation. Citrate process results in uniformly dispersed mixed oxide with higher catalytic activity.

  9. Cholesteryl ester transfer protein inhibitors in coronary heart disease: Validated comparative QSAR modeling of N, N-disubstituted trifluoro-3-amino-2-propanols.

    Science.gov (United States)

    Mondal, Chanchal; Halder, Amit Kumar; Adhikari, Nilanjan; Jha, Tarun

    2013-10-01

    Cholesteryl ester transfer protein (CETP) converts high density lipoprotein cholesterol to low density lipoproteins. It is a promising target for treatment of coronary heart disease. Two dimensional quantitative structure activity relationship (2D-QSAR), hologram QSAR (HQSAR) studies and comparative molecular field analysis (CoMFA) as well as comparative molecular similarity analysis (CoMSIA) were performed on 104 CETP inhibitors. The statistical qualities of generated models were justified by internal and external validation, i.e., q(2) and R(2)pred respectively. The best 2D-QSAR model was obtained with q(2) and R(2)pred values of 0.794 and 0.796 respectively. The 2D-QSAR study suggests that unsaturation, branching and van der Waals volumes may play important roles. The HQSAR model showed q(2) and R(2)pred values of 0.628 and 0.550 respectively. Similarly, CoMFA model showed q(2) and R(2)pred values of 0.707 and 0.755 respectively whereas CoMSIA model was obtained with q(2) and R(2)pred values of 0.696 and 0.703 respectively. CoMFA and CoMSIA studies indicate that steric factors are important at substituted phenoxy and tetrafluoroethoxy groups whereas electropositive factors play important role at difluoromethyl group. The results of 3D-QSAR studies validate those of 2D-QSAR and HQSAR studies as well as the earlier observed SAR data. Current work may help to develop better CETP inhibitors.

  10. Preparation of(S)-1-Phenylsulfonyl-2-Propanol through Asymmetric Reduction by Baker's Yeast%面包酵母不对称还原制备(S)-1-苯砜基-2-丙醇

    Institute of Scientific and Technical Information of China (English)

    石月丹; 周子彦; 谢玉忠

    2006-01-01

    用自制的溴代丙酮与苯亚磺酸钠反应合成1-苯砜基-2-丙酮,然后利用面包酵母在有机溶剂中不对称催化还原1-苯砜基-2-丙酮,制备了光学活性的手性化合物(S)-1-苯砜基-2-丙醇,此反应具有操作简便、光学产率高等优点,其化学产率可达94%以上,对映体过量值为100%.

  11. Synthesis and antifungal activity of 1- ( 1 H-1, 2,4-triazol-1-yl) -2- (2,4-difluorophenyl)-3-(4-substituted acyl piperazin-1-yl)-2-propanols

    Institute of Scientific and Technical Information of China (English)

    LIANG Shuang; LIU Chao-mei; ZHU Jie; HE Qiu-qin; JIANG Yuan-ying; CAO Yong-bin

    2004-01-01

    Objective: To study the effect of fluconzole derivatives from a side chain containing 4-substituted acyl piperazin-1-yl on antifungal activity. Methods: Fourteen title compounds were synthesized and confirmed by the elementary analysis, 1HNMR and IR spectra. Five deep fungal strains and 3 shallow fungal strains were chosen as the experimental strains. Minimum inhibitory concentrations(MICs) of all title compounds were determined by the method recommended by the National Committee for Clinical Laboratory Standards (NCCLS) using RPMI 1640 test medium. Results: Among the 14title compounds, 12 were first reported. The results of preliminary antifungal test showed that all the title compounds exhibited potent antifungal activities to a certain extent. The activity of 4 compounds were more than 4 times as high as that of fluconazole and equal to that of ketoconazole against Candida albicans in vitro(MIC80 value≤0. 125 μg/ml). Conclusion:Introduction of a side chain containing 4-substituted acyl piperazin-l-yl into the main part of fluconazole has important influence on antifungal activities of title compounds.

  12. Kinetics of the asymmetrie synthesis of 1-phenylsulfonyl-2-propanol by baker's yeast in microaqueous organic solvent%微水有机溶剂中面包酵母催化不对称还原(S)-1-苯砜-2-丙酮的动力学研究

    Institute of Scientific and Technical Information of China (English)

    谢玉忠; 李向霞; 周子彦

    2005-01-01

    探讨在微水有机溶剂中面包酵母催化不对称还原(S)-1-苯砜-2-丙酮的动力学,分别求出30 ℃和35 ℃下的反应速率常数和米氏常数.实验结果表明面包酵母在35℃时的催化活性比30 ℃时要高.

  13. Excess Molar Volumes and Viscosities for Binary Mixtures of 1-Alkoxypropan-2-ols with 1-Butanol,and 2-Butanol at 298.15 K and Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    PAL Amalendu; GABA Rekha

    2007-01-01

    Excess molar volumes VEm and kinematic viscosities v have been measured as a function of composition for binary mixtures of propylene glycol monomethyl ether (1-methoxy-2-propanol),MeOCH2CH(OH)Me,propylene glycol monoethyl ether (1-ethoxy-2-propanol), EtOCH2CH(OH)Me,propylene glycol monopropyl ether (1-propoxy-2-propanol), PrOCH2CH(OH)Me, propylene glycol monobutyl ether (1-butoxy-2-propanol),BuOCH2CH(OH)Me,and propylene glycol tert-butyl ether (1-tert-butoxy-2-propanol),t-BuOCH2CH(OH)Me with 1-butanol,and 2-butanol,at 298.15 K and atmospheric pressure.The excess molar volumes are negative across the entire range of composition for all the systems with 1-butanol,and positive for the systems 2-butanol+1-methoxy-2-propanol,and +1-propoxy-2-propanol,negative for the systems 2-butanol+1-butoxy-2-propanol,and change sign for the systems 2-butanol+1-ethoxy-2-propanol,and +1-tert-butoxy-2-propanol.From the experimental data,the deviation in dynamic viscosity η from Σxiηi has been calculated.Both excess molar volumes and viscosity deviations have been correlated using a Redlich-Kister type polynomial equation by the method of least-squares for the estimation of the binary coefficients and the standard errors.

  14. Determination of p-Acetaminobenzoic Acid and N,N-Dimethylamino-2-propanol in Human Urine by LC-MS and Study on Their Urinary Excretion Profiles%人尿中对乙酰氨基苯甲酸和N,N-甲氨基-2-丙醇的液质联用法测定及尿药排泄特征研究

    Institute of Scientific and Technical Information of China (English)

    于勇; 孙鲁宁; 杜晓琅; 饶雅琨; 丁雯; 丁黎; 肖慧凤; 陈益智

    2011-01-01

    目的:建立分别测定人尿中对乙酰氨基苯甲酸和N,N-二甲氨基-2-丙醇的液质联用法,考察二者在中国健康受试者尿液中的排泄特征.方法:以LC-MS法测定尿样中对乙酰氨基苯甲酸,色谱采用Amethyst C18柱(150 mm×2.1 mm,5 μm),流动相为甲醇-0.1%甲酸水溶液(25:75),流速为0.4 mL·min-1;质谱采用气动辅助电喷雾离子化和正离子选择性离子检测.以LC-MS/MS法测定尿样中N,N-二甲氨基-2-丙醇,色谱采用Hedera CN柱(150 mm×2.1 mm,5 μm),流动相为乙腈-5 mmol·L-1醋酸铵水溶液(含0.03%甲酸)(55:45),流速为0.35 mL·min-1;质谱采用气动辅助电喷雾离子化和正离子多反应检测.10名受试者单次口服异丙肌苷片(1.0 g),测定对乙酰氨基苯甲酸和N,N-二甲氨基-2-丙醇的尿药排泄参数.结果:对乙酰氨基苯甲酸的尿药浓度在0.202 0-202.0 mg·L-1范围内线性关系良好,平均回收率大于97.7%;N,N-二甲氨基-2-丙醇尿药浓度在0.797 8-398.9 mg·L-1范围内线性关系良好,平均回收率大于99.1%.受试者服药后,对乙酰氨基苯甲酸和N,N-二甲氨基-2-丙醇分别在6和12 h后基本随尿排泄完全,36 h内其平均尿药累积排泄百分率分别为(30.7±5.7)%和(49.0±8.6)%.结论:本法适用于人尿中对乙酰氨基苯甲酸和N,N-二甲氨基-2-丙醇的测定及其尿药排泄特征研究.

  15. 1-(1H-1,2,4-三唑-1-基)-2-(2,4-二氟苯基)-3-[N-异丙基-N-(4-取代苄基)]-2-丙醇的合成及抗真菌活性%Synthesis and antifungai activity of 1-( 1H-l, 2,4-triazole-l-yl )-2-( 2,4-difluoroph-enyl ) -3- ( N-cycloproyl-N- benzyl-amino )-2-propanols

    Institute of Scientific and Technical Information of China (English)

    闫永正; 柴晓云; 邹燕; 俞世冲; 吴秋业

    2011-01-01

    目的 研究具有异丙基结构的氮唑类化合物的抗真菌活性.方法 引入4位羧酸酯取代的苄基侧链结构,合成一系列目标化合物,所有化合物结构均经MS、1H-NMR等谱确证;选择8种真菌为实验菌株,测定其体外抗真菌活性.结果 合成了14个未见文献报道的目标化合物;所有化合物对所选真菌均表现出了一定的抑菌活性,其中化合物(1)和(2)对除薰烟曲霉菌外的7种菌都表现出了较好的抑菌活性.结论 4位羧酸酯取代的苄基侧链结构的引入对目标化合物的抗菌活性有一定的影响,侧链越短,抑菌活性越好.%Objective To study the antifungal activity of triazole alcohols which introduce isopropyl as side chain. Methods By introduction of 4-carboxylic ester substituted benzyl group as side chain, a series of title compounds were synthesized. All of them were confirmed by MS, 'H-NMR, et al. The antifungal activities were also evaluated against eight tested pathogenic fungi. Results Fourteen title compounds were synthesized. All title compounds exhibited activity against tested fungi to some extent. Compounds (1) and (2) exhibited stronger antifungal activities against eight fungi except Aspergillus fumigatus than the control drug of itraconazole. Conclusions The introduction of 4-carboxylic ester substituted benzyl group as side chain was beneficial to improve their antifungal activity. The shorter in the side chain , the better of the antifungal activity.

  16. Biotransformation of low-molecular-weight alcohols by Coleus forskohlii hairy root cultures.

    Science.gov (United States)

    Li, Wei; Koike, Kazuo; Asada, Yoshihisa; Yoshikawa, Takafumi; Nikaido, Tamotsu

    2003-04-04

    Coleus forskohlii hairy root cultures were shown to biotransform methanol and ethanol to the corresponding beta-D-glucopyranosides and beta-D-ribo-hex-3-ulopyranosides, and 2-propanol to its beta-D-glucopyranoside.

  17. Disease: H00054 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available nces in cancer epidemiology: understanding causal mechanisms and the evidence for implementing interventions. Annu Rev Public Health...ol, and 1-tert-butoxy-2-propanol. Environ Health Perspect 113:1205-8 (2005) PMID:

  18. Mapping Nanoscale Absorption of Femtosecond Laser Pulses Using Plasma Explosion Imaging

    Science.gov (United States)

    2014-08-06

    vinylpyrrolidone) þ 1-Propanol and þ 2-Propanol at 298.15 K. J. Chem. Eng. Data 2009, 54, 1073–1075. 41. Palik , E. D. Handbook of Optical Constants of Solids; Academic Press: Boston, 1985. A RTIC LE

  19. Nitrogen Trifluoride: Its Chemistry, Toxicity, and Safe Handling.

    Science.gov (United States)

    1976-11-12

    the NE3/glass reaction. Mixtures of water vapor , ammonia , or 2-propanol with NE3 exothermed at temperatures higher than NE3 alone , and these fuels...2-propanol and ammonia may have reacted either directly with NF3 or with nitrogen oxides produced by an NF3/glass reaction. I. B. Reactions of NF3... spleens were found in many of the surviving rats. After intra peritoneal in- jection of 10 ml of undiluted nitrogen trifluoride , the rats appeared

  20. Polymer Production by Plasma Polymerization of Oxygenated Organic Compounds

    Directory of Open Access Journals (Sweden)

    Antonio P. Nascimento Filho

    2002-10-01

    Full Text Available This work was aimed at producing new polymeric materials using oxygenated organic compounds as main reactants and plasma enhanced chemical vapor deposition (PECVD as a production technique. The films obtained were analyzed by profilometry, in order to determine the deposition rate, by Infrared Spectroscopy (FTIR to identify the species deposited and by contact angle measurements to determine the polarity of the surface. For the reactants used, namely ethanol, acetone and 2-propanol, the plasma deposition process was least efficient with ethanol followed by acetone and 2-propanol. With the latter, reproducible thin films were obtained with a high deposition rate (up to 400 Å/min. These films had a high amount of OH and could be wetted by common organic solvents, such as 2-propanol or acetone. The contact angle formed by drops of 2-propanol or acetone aqueous solution on the film produced from 2-propanol varied significantly with the concentration, from 0.9% to 50% by vol., indicating that the film is sensitive to polar solutions.

  1. Preconcentration in gas or liquid phases using adsorbent thin films

    Directory of Open Access Journals (Sweden)

    Antonio Pereira Nascimento Filho

    2006-03-01

    Full Text Available The possibility of preconcentration on microchannels for organic compounds in gas or liquid phases was evaluated. Microstructures with different geometries were mechanically machined using poly(methyl methacrylate - PMMA as substrates and some cavities were covered with cellulose. The surfaces of the microchannels were modified by plasma deposition of hydrophilic or hydrophobic films using 2-propanol and hexamethyldisilazane (HMDS, respectively. Double layers of HMDS + 2-propanol were also used. Adsorption characterization was made by Quartz Crystal Measurements (QCM technique using reactants in a large polarity range that showed the adsorption ability of the structures depends more on the films used than on the capillary phenomena. Cellulose modified by double layer film showed a high retention capacity for all gaseous compounds tested. However, structures without plasma deposition showed low retention capacity. Microchannels modified with double layers or 2-propanol plasma films showed higher retention than non-modified ones on gas or liquid phase.

  2. Deuteriation exchange (with the deuteriated catalyst surface) and the ratio of dehydrogenation and dehydration of. cap alpha. - and. beta. -substituted ethanols on basic oxides

    Energy Technology Data Exchange (ETDEWEB)

    Thomke, K.

    1977-01-01

    The pulsed reactions of ethanol, 1- and 2-propanol, 1- and 2-butanol, 2-methyl-2-propanol, and 3-pentanol on deuteriated magnesium, samarium, thorium, and lanthanum oxides showed that no deuterium was incorporated at a carbon of 2-methyl-2-propanol (i.e., that the reaction did not proceed by the E1cB mechanism); that all the secondary alcohols formed olefins and ketones and incorporated deuterium only in the ..beta..-position; and that primary alcohols formed olefins and aldehydes on all catalysts except lanthanum oxide (which catalyzed only dehydration of primary alcohols) and incorporated deuterium in the ..cap alpha..-position on magnesium and thorium oxide. The mechanism is discussed. Table.

  3. Prediction of vapor-liquid equilibria for the alcohol + glycerol systems using UNIFAC and modified UNIFAC (Dortmund)

    Science.gov (United States)

    Hartanto, Dhoni; Mustain, Asalil; Nugroho, Febry Dwi

    2017-03-01

    The vapor-liquid equilibria for eight systems of alcohols + glycerol at 101.325 kPa have been predicted in this study using UNIFAC and Modified UNIFAC (Dortmund) group contribution methods. The investigated alcohols were methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol and 2-methyl-2-propanol. In order to study the accuracy of both contribution methods, the predicted data obtained from both approaches were compared to the experimental data from the literature. The prediction accuracy using modified UNIFAC (Dortmund) give better results compared to the UNIFAC method for (ethanol, 1-propanol, 2-propanol and 1-butanol) + glycerol but UNIFAC method show better accuracy for methanol + glycerol system. In addition, the influences of carbon chain length on the phase behaviours of alcohol + glycerol systems were also discussed as well.

  4. KBPh4由水到系列水 -醇混合溶剂的迁移自由能%Systematic Study of the Standard Transfer Gibbs Energy of Potassium Tetrophenylborate from Water to Water and Alcohol Mixtures

    Institute of Scientific and Technical Information of China (English)

    曹立新; 周保学; 史鹏飞; 邹立壮

    2001-01-01

    The standard transfer Gibbs energies (Δ trG° )of KBPh4 from reference solvent of water to water/ethanol, water/propanol, water/2-propanol,water/ethylene glycol, water/glycerol mixtures in different proportional ratio have been studied. The interactions of KBPh4 with the above mixed solvents were analyzed. The standard transfer Gibbs energy of cavity(Δ trG° cav) and the standard transfer Gibbs energy of interaction(Δ trG° int) from water to water/2-propanol mixtures at 298.15 K were calculated by the Scaled Particle Theory (SPT).

  5. Environmental stress cracking in gamma-irradiated polycarbonate - A diffusion approach

    Science.gov (United States)

    Silva, Pietro Paolo J. C. de O.; Araújo, Patricia L. B.; da Silveira, Leopoldo B. B.; Araújo, Elmo S.

    2017-01-01

    Polycarbonate (PC) is an engineering polymer which presents interesting properties. This material has been also used in medical devices, which is frequently exposed to gamma radiosterilization and to chemical agents. This may produce significant changes in polymer structure, leading to failure in service. The present work brings about a new approach on environmental stress cracking (ESC) processes elucidation in 100 kGy gamma-irradiated PC, by evaluating the diffusion process of methanol or 2-propanol in test specimens and determining the diffusion parameters on solvent-irradiated polymer systems. A comparison of diffusion parameters for both solvents indicated that methanol has a considerable ESC action on PC, with diffusion parameter of 7.5×10-14±1% m2 s-1 for non-irradiated PC and 7.8×10-14±2.8% m2 s-1 for PC irradiated at 100 kGy. In contrast, 2-propanol did not act as an ESC agent, as it did promote neither swelling nor cracks in the test specimens. These results were confirmed by visual analysis and optical microscopy. Unexpectedly, structural damages evidenced in tensile strength tests suggested that 2-propanol is as aggressive as methanol chemical for PC. Moreover, although some manufacturers indicate the use of 2-propanol as a cleaning product for PC artifacts, such use should be avoided in parts under mechanical stress.

  6. Microwave Assisted Synthesis of N-Arylheterocyclic Substituted-4-aminoquinazoline Derivatives

    Directory of Open Access Journals (Sweden)

    Ping Lu

    2006-04-01

    Full Text Available A simple, efficient, and general method has been developed for the synthesis of various N-aryl heterocylic substituted-4-aminoquinazoline compounds from 4-chloro- quinazoline and aryl heterocyclic amines under microwave irradiation using 2-propanol as solvent. The advantages of the use of microwave irradiation in relation to the classical method were demonstrated.

  7. An Inexpensive, Relatively Green, and Rapid Method to Purify Genomic DNA from "Escherichia Coli": An Experiment for the Undergraduate Biochemistry Laboratory

    Science.gov (United States)

    Sims, Paul A.; Branscum, Katie M.; Kao, Lydia; Keaveny, Virginia R.

    2010-01-01

    A method to purify genomic DNA from "Escherichia coli" is presented. The method is an amalgam of published methods but has been modified and optimized for use in the undergraduate biochemistry laboratory. Specifically, the method uses Tide Free 2x Ultra laundry detergent, which contains unspecified proteases and lipases, "n"-butanol, 2-propanol,…

  8. DIFFUSION MEASUREMENTS DURING PERVAPORATION THROUGH A ZEOLITE MEMBRANE

    Science.gov (United States)

    An isotopic-transient technique was used to directly measure diffusion times of H2O, methanol, ethanol, 2-propanol, and acetone in pure and binary mixture feeds transporting through a zeolite membrane under steady-state pervaporation conditions. Diffusivities can be determ...

  9. UPTAKE OF RADIOLIGANDS BY RAT-HEART AND LUNG INVIVO - CGP-12177 DOES AND CGP-26505 DOES NOT REFLECT BINDING TO BETA-ADRENOCEPTORS

    NARCIS (Netherlands)

    van Waarde, A; Meeder, JG; BLANKSMA, PK; BRODDE, OE; VISSER, GM; ELSINGA, PH; PAANS, AMJ; VAALBURG, W; LIE, KI

    1992-01-01

    The biodistribution of (-)-4-(3-t-butylamino-2-hydroxypropoxy)-[5,7-H-3-benzimidazol-2-one (CGP12177, a non-selective beta-adrenoceptor antagonist) and 1-[2-(3-carbamoyl-4-hydroxy)-(5-H-3-phenoxy)]-2-propanol methanesulfonate, (CGP26505, a beta1-adrenoceptor antagonist) was studied in rats pretreate

  10. The Optical Resolution of Chiral Tetrahedrone-type Clusters Contai- ning SCoFeM (M=Mo or W) Using High Performance Liquid Chromatography Chiral Stationary Phase

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Amylose tris (phenylcarbamate) chiral stationary phase (ATPC-CSP) was prepared and used for optical resolution of clusters 1 and 2. n-Hexane/2-propanol ( 99/1; v/v) were found to be the most suitable mobile phase on ATPC-CSP.

  11. Crosslinked agarose encapsulated sorbents resistant to steam sterilization. Preparation and mechanical properties

    NARCIS (Netherlands)

    Koning, de Henk W.M.; Chamuleau, Rob A.F.M.; Bantjes, Adriaan

    1983-01-01

    The application of agarose in hemoperfusion is hampered by the lack of a suitable sterilization method. A technique has been developed for the crosslinking of agarose encapsulated sorbents by the reaction with 1,3-dichloro-2-propanol (DCP) under strong alkaline conditions. A twofold molar excess of

  12. Acid-Base Bifunctional Zirconium N-Alkyltriphosphate Nanohybrid for Hydrogen Transfer of Biomass-Derived Carboxides

    DEFF Research Database (Denmark)

    Li, Hu; He, Jian; Riisager, Anders

    2016-01-01

    sites, and their catalytic activity in converting biomass-derived carbonyl compounds to corresponding alcohols in 2-propanol. Particularly, a quantitative yield of furfuryl alcohol (FFA) was obtained from furfural (FUR) over organotriphosphate-zirconium hybrid (ZrPN) under mild conditions. The presence...

  13. Properties of electrospun pollock gelatin/poly(vinyl alcohol) and pollock gelatin/poly(lactic acid) fibers

    Science.gov (United States)

    Pollock gelatin/poly(vinyl alcohol) (PVA) fibers were electrospun using deionized water as the solvent and pollock gelatin/poly(lactic acid) (PLA) fibers were electrospun using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as the solvent. The chemical, thermal, and thermal stability properties were exami...

  14. Design,Synthesis and Antifungal Activity of Novel Triazole Derivatives

    Institute of Scientific and Technical Information of China (English)

    Chun Quan SHENG; Wan Nian ZHANG; Hai Tao JI; Yun Long SONG; Min ZHANG; You Jun ZHOU; Jia Guo LU; Jü ZHU

    2004-01-01

    Twenty-one 1-(1H-1,2,4-triazolyl)-2-(2,4-diflurophenyl)-3-(4-substituted-1- piperazinyl)-2-propanol derivatives were designed and synthesized,on the basis of the active site of lanosterol 14(-demethylase.In vitro antifungal activities showed that some of the target compounds had higher antifungal activity and broader antifungal spectrum than fluconazole.

  15. Solid–liquid equilibria for binary and ternary systems with the Cubic-Plus-Association (CPA) equation of state

    DEFF Research Database (Denmark)

    Fettouhi, André; Thomsen, Kaj

    2010-01-01

    A systematic investigation of the CPA model's performance within solid-liquid equilibria (SLE) in binary mixtures (methane + ethane, methane + heptane, methane + benzene, methane + CO2, ethane + heptane, ethane + CO2, 1-propanol + 1,4-dioxane, ethanol + water, 2-propanol + water) is presented...

  16. Quantification of the beta-adrenoceptor ligand S-1'[F-18]fluorocarazolol in plasma of humans, rats and sheep

    NARCIS (Netherlands)

    vanWaarde, A; Posthumus, H; Elsinga, PH; Anthonio, RL; van Loenen - Weemaes, Anne-miek; Beaufort-Krol, Gertie C. M.; Paans, AMJ; Vaalburg, W; Visser, Thomas; Visser, Gerben

    1996-01-01

    Myocardial and pulmonary beta-adrenoceptors can be imaged with 2-(S)-(-)-(9H-carbazol-4-yl-oxy)-3-[1-(fluoromethyl)ethyl]amino-2-propanol (S-1'-[F-18]fluorocarazolol, I). Quantification of unmodified fluorocarazolol in plasma is necessary for analysis of PET images in terms of receptor densities. We

  17. Solvent selection for solid-to-solid synthesis

    NARCIS (Netherlands)

    Ulijn, R.V.; Martin, de L.; Gardossi, L.; Janssen, A.E.M.; Moore, B.D.; Halling, P.J.

    2002-01-01

    Thermolysin catalyzed solid-to-solid synthesis of the model peptide Z-L-Phe-L-Leu-NH2 is practically feasible in water and a range of organic solvents with different physicochemical properties. Excellent overall conversions were obtained in acetonitrile, ethyl acetate, n-hexane, methanol, 2-propanol

  18. Preparation of PtRu/C anode electrocatalysts using gamma radiation for methanol electro-oxidation; Preparacao de eletrocatalisadores PtRu/C utilizando radiacao gama para aplicacao como anodo na oxidacao direta de metanol

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio Fortunato da

    2006-07-01

    Pt Ru/C (carbon-supported Pt Ru nanoparticles) anode electrocatalysts were prepared using radiolytic process (gamma radiation) and tested for methanol electro-oxidation. In this process, water/2-propanol and water/ethylene glycol solutions containing the metallic ions and the carbon support were submitted to gamma radiation under stirring. The water/alcohol ratio (v/v) and the total dose (kGy) were studied. A nominal Pt Ru atomic ratio of 50:50 were used in all experiments. The electrocatalysts were characterized by energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and cyclic voltammetry (CV). The electro-oxidation of methanol was studied by cyclic voltammetry using the thin porous coating technique. The electrocatalysts prepared in water/2-propanol showed crystallite size in the range of 3-5 nm and Pt Ru atomic ratio of 50:50. The electrocatalysts prepared in water/ethylene glycol showed crystallite size (2-3 nm) smaller than the ones obtained in water/2-propanol, however, the Pt Ru atomic ratios obtained were approximately 80:20, showing that only part of ruthenium ions were reduced. For methanol oxidation the electrocatalytic activity depends on the water/2-propanol and water/ethylene glycol ratio used in the reaction medium. The electrocatalysts prepared in water/2-propanol showed inferior performance to the ones prepared in water/ethylene glycol, which showed similar or superior performances (amperes per gram of platinum) to the commercial electrocatalyst from E-TEK. (author)

  19. Formation of Silver Nanoplates Layer on Amino Group Grafted Silica Coatings

    Directory of Open Access Journals (Sweden)

    Jurgis PILIPAVICIUS

    2016-05-01

    Full Text Available In this study the self-arrangement of Ag nanoplates on (3-Aminopropyltriethoxysilane (APTES silanized silica coatings was investigated. Silica coatings were made by sol-gel method and silanized in two different ways. The first one includes silanization in acidic 2-propanol solution, the other one – in dry toluene. Coatings were silanized by using different amounts of APTES in case of silanization in 2-propanol. Silver nanoplates layer of functionalized silica coatings was obtained via self-assembly. Coatings were investigated by atomic force microscopy (AFM, water contact angle measurements (CA, FT-IR analysis, and scanning electron microscopy (SEM. Research showed that dense Ag nanoplates arrangement occurs when there is a high amount of amino groups on the surface.DOI: http://dx.doi.org/10.5755/j01.ms.22.2.8405

  20. Hydrogen generation from renewable resources

    Energy Technology Data Exchange (ETDEWEB)

    Loges, Bjoern

    2009-09-04

    In this thesis, the hydrogen generation by dehydrogenation of 2-propanol and formic acid as model substances for renewable resources have been studied, which is of importance for hydrogen storage. For the base-assisted dehydrogenation of 2-propanol, a ruthenium diamine catalyst system has been investigated. For the selective decomposition of formic acid to hydrogen and carbon dioxide, a system has been established containing ruthenium catalysts and formic acid amine adducts as substrates. The best catalyst activity and productivity have been achieved with in situ generated ruthenium phosphine catalysts, e.g. [RuCl{sub 2}(benzene)]{sub 2} / dppe (TOF = 900 h{sup -1}, TON = 260,000). The gas evolved has been directly used in fuel cells. Furthermore, the influence of irradiation with visible light has been described for the ruthenium phosphine catalysts. (orig.)

  1. Synthesis and characterization of yttrium aluminium garnet (YAG powders

    Directory of Open Access Journals (Sweden)

    Magdalena Zarzecka-Napierala

    2007-12-01

    Full Text Available In this paper synthesis and characterization of YAG powders, prepared by a process based on complexing properties of citric acid, was reported. Influence of citric acid estrification induced by 2-propanol or ethylene glycol on the system homogeneity was investigated. These reagents were introduced to aqueous solution of yttrium and aluminium nitrates. A variety of powders from Al2O3-Y2O3 system with different phase composition were obtained by altering the citrate to nitrate ratio. Evolution of the powders phase composition vs. temperature was investigated using DTA/TG, XRD, and FT-IR methods. The most interesting results were observed in case of the citric acid–propanol–relative nitrates system. The mole ratio of these reagents equal to 1:2.5:2.5 (nitrates (Al,Y:citric acid:2-propanol allowed to synthesize pure YAG phase powders at temperature as low as 950°C.

  2. Investigation of the solubility and the potentials for purification of serum amyloid A (SAA) from equine acute phase serum

    DEFF Research Database (Denmark)

    Christensen, Michelle Brønniche; Sørensen, Jens Christian; Jacobsen, Stine

    2013-01-01

    for purification of equine SAA based on biochemical properties.Freeze dried equine acute phase serum was dissolved in 70% 2-propanol, 8 M urea, and milli-Q water, respectively. Supercritical fluid extraction (SFE), size-exclusive chromatography (FPLC-SEC), and preparative isoelectric focusing (IEF) were performed...... in the attempt to purify. Immunostaining of IEF blots were used for isoform-specific detection of SAA in the preparations and purity was assessed by silverstained SDS-PAGE. FINDINGS: SAA was soluble in 70% 2-propanol, 8 M urea and Milli-Q water. SAA was not separated in the lipophilic or ampipathic fractions...... following SFE. SAA was included in a FPLC-SEC-fraction of 237 kDa, despite the molecular weight known to be much smaller, suggesting binding to other serum constituents. SAA precipitated following separation of other serum proteins by preparative IEF. DISCUSSION: No effective purification of SAA...

  3. Aqueous two-phase extraction of 2,3-butanediol from fermentation broths by isopropanol/ammonium sulfate system.

    Science.gov (United States)

    Sun, Li-Hui; Jiang, Bo; Xiu, Zhi-Long

    2009-03-01

    A novel aqueous two-phase system consisted of 2-propanol/ammonium sulfate was used for the extraction of 2,3-butanediol from fermentation broths. The maximum partition coefficient and recovery of 2,3-butanediol reached 9.9 and 93.7%, respectively, and more than 99% of the cells and about 85% of the soluble proteins were removed when 34% (w/w) 2-propanol and 20% (w/w) ammonium sulfate were used. The separated cells could be re-used as inocula for subsequent fermentations. The aqueous two-phase system described in this study may have potential application in the extraction of 2,3-butanediol produced by industrial fermentation processes.

  4. Chemical isomeric effects on propanol glassy structures

    CERN Document Server

    Cuello, G J; Bermejo, F J; Cabrillo, C

    2002-01-01

    We have studied the structure of both propanol isomers in their glassy and crystalline states by neutron diffraction. The glass-transition temperatures of 1- and 2-propanol are about 98 and 115 K, respectively and, surprisingly, even larger differences are observed for the melting temperatures of the stable crystals, which are 148 and 185 K, respectively. Their supercooled liquid phases show rather different relaxation spectra, 1-propanol manifesting strong deviations from Debye behavior, whereas 2-propanol shows a far weaker effect. We discuss the spectra obtained for the static structure factor and the static pair correlation function D(r). There is a noticeable difference in the position of the first sharp diffraction peak, which clearly indicates a density change, well correlated with the period of the intermolecular oscillations shown by D(r). (orig.)

  5. Synthesis of high refractive spiro heterocyclic derivatives through thioacetalization of multi-carbonyl compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Jim Young; Maheswara, Muchchintala; Do, Jung Yun [Pusan National Univ., Busan (Korea, Republic of)

    2012-04-15

    Preparation of several new spirocyclic mercaptol derivatives is described. Thiol protection on multi-carbonyl compounds allows of high sulfur content necessary to induce high refractive index. Condensation of 1,3-dimercapto-2-propanol and cyclohexanone followed by successive oxidation and thioacetalization affords a dispiro cycle with four sulfurs. Selective S,S-protection of cyclohexane-1,4-dione is achieved with 1,3-dimercapto-2-propanol and 2,3-dimercapto-1-propanol to provide dispiro cycles with four sulfurs. Olefineoxidation of norbornene gives a useful dialdehyde intermediate which is transformed to 1,3-dithiolane for a linearly-bound-cyclic molecule. Refractive index of linearly-bound-cycles was below 1.60 and dispiro cycles exhibited high refractive index of 1.57-1.69.

  6. 双回流动态累积间歇精馏全过程的研究%Study on dynamic-accumulation batch distillation of a noveloperation tower with double-reflux

    Institute of Scientific and Technical Information of China (English)

    张兵; 陈立峰; 李文秀

    2011-01-01

    在动态累积间歇精馏塔中,采用双回流动态累积间歇精馏操作对正丙醇-异丙醇二元混合物系进行分离研究.主要考察了操作时间对塔顶整个过程产品浓度、温度变化的影响,并与塔顶回流动态累积间歇精馏操作的分离结果进行了比较,以及过渡馏分阶段操作时间对塔釜正丙醇浓度及温度变化的影响,同时,又对正丙醇的回收进行了研究.结果表明,在同样的产品采出要求条件下,双回流动态累积间歇精馏操作时,随原料中异丙醇含量的增加,所需的操作时间越长,产品的纯度越高,收率越高;操作时间节省166 min,原料中异丙醇质量分数为30%的条件下,所得回收正丙醇的纯度达到91.22%,正丙醇的回收率可达62.93%,原料中异丙醇质量分数别为30%、50%、70%时对应过渡馏分持续时间分别为40、47、58m in;原料中异丙醇质量分数越大,所得回收正丙醇产品的量越少,正丙醇的纯度越低,回收率越小.%A novel double-reflux operation mode by reflux at both top and bottom was applied in a dynamic-accumulation batch distillation tower. Binary mixture of 1-propanol and 2-propanol as the separated system,in the state progress the mass fraction change of 2-propanol and temperature with operation time at top was studied, while the effection was compared with the operation by reflux at top;during slop cut stage the mass fraction change of 1-propanol and temperature at bottom with operation time were mainly discussed. The recovery of 1-propanol was mainly considered. The experiment results indicate that the operation time, mass fraction of 2-propanol in product and yield of 2-propanol all increase with the mass fraction of 2-propanol added more in feed at the same condition of product quality. When mass fraction of 2-propanol in feed was 30% ,the mass fraction of 1-propanol in product was 91. 22% and yield of 1-propanol was 62. 93% . When mass fraction of 2-propanol

  7. Refractive indices of ternary liquid mixtures containing aliphatic alcohols at several temperatures

    Directory of Open Access Journals (Sweden)

    Sovilj Milan N.

    2005-01-01

    Full Text Available The refractive indices of ternary liquid mixtures (2-propanol+2-butanol+ethanol and (chloroform+2-propanol+2-butanol were measured at 20, 25, 30, and 35°C, and atmospheric pressure. The results were used to calculate the refractive index deviations over the entire mole fraction range for the mixtures. The refractive index deviations for the ternary mixtures were further fitted to empirical correlations (Cibulka Nagata-Tamura, and Lopez et al to estimate the ternary fitting parameters. Standard deviations and average percentage deviations from the regression lines are shown. The best fit was obtained by the Nagata-Tamura empirical correlation. Some of the existing predictive equations for the refractive index deviations (Tsao-Smith, Köhler, and Colinet were tested.

  8. Alcohol and water adsorption in zeolitic imidazolate frameworks

    KAUST Repository

    Zhang, Ke

    2013-01-01

    Alcohol (methanol, ethanol, 1-propanol, 2-propanol and 1-butanol) and water vapor adsorption in zeolitic imidazolate frameworks (ZIF-8, ZIF-71 and ZIF-90) with similar crystal sizes was systematically studied. The feasibility of applying these ZIF materials to the recovery of bio-alcohols is evaluated by estimating the vapor-phase alcohol-water sorption selectivity. © 2013 The Royal Society of Chemistry.

  9. Irritation durch Waschen und Desinfizieren

    OpenAIRE

    Weimer, Caroline Maria

    2006-01-01

    Ziel dieser Studie war die Irritation der Haut, hervorgerufen durch alkoholische Desinfektionsmittel und das Detergens Natriumlaurylsulfat (0,5% NLS) in einem repetitiven Testdesign zu untersuchen. Mittels nicht invasiver Untersuchungsmethoden quantifizierten wir die irritativen Effekte von Sterillium®, 2-Propanol 45% v/v, 1-Propanol 30% v/v, welches die alkoholische Grundlage von Sterillium® darstellt sowie von Wasser und NLS 0,5...

  10. Catalysis in the alkylation reaction of 1-naphthol with epichlorohydrin

    Directory of Open Access Journals (Sweden)

    SLOBODANKA JOVANOVIC

    2006-09-01

    Full Text Available Two new and improved procedures were developed for the synthesis of 1-(1-naphthyloxy-2,3-epoxypropane as an important intermediate in the production of the beta-blocker and antioxidant, 1-[(1-methylethylamino]-3-(1-naphthyloxy-2-propanol (propranolol. Both base homogeneous and heterogeneous PTC catalysis were employed. High yields and remarkable selectivity were achieved. The improved purity is particularly important, in view of the quality requirements for propranolol hydrochloride as an active pharmaceutical ingredient.

  11. Influencia del solvente en el espectro ultravioleta del 4-nitrobifenilo

    Directory of Open Access Journals (Sweden)

    Jaime de la Zerda L.

    2009-05-01

    Full Text Available Se estudiaron los efectos de solvente en la banda del 4-nitrobifenilo en los alcoholes metanol, etanol, I propanol, 2 propanol, 1-butanol, 2-metilpropanol, que fueron purificados cuidadosamente, determinándose luego el grado de pureza que resultó satisfactorio en casi todos los casos. Por ser el agua la impureza persistente en todos ellos, fue necesario estudiar su efecto con cierto detalle.

  12. Organic Photocatalytic Cyclization of Polyenes: A Visible-Light-Mediated Radical Cascade Approach.

    Science.gov (United States)

    Yang, Zhongbo; Li, Han; Zhang, Long; Zhang, Ming-Tian; Cheng, Jin-Pei; Luo, Sanzhong

    2015-10-12

    A visible-light-mediated, organic photocatalytic stereoselective radical cascade cyclization of polyprenoids is described. The desired cascade cyclization products are achieved in good yields and high stereoselectivities with eosin Y as photocatalyst in hexafluoro-2-propanol. The catalyst system is also suitable for 1,3-dicarbonyl compounds, which require only catalytic amounts of LiBr to promote the formation of the corresponding enols.

  13. Synthesis of novel chiral N, P-containing multidentate ligands and their applications in asymmetric transfer hydrogenation

    Institute of Scientific and Technical Information of China (English)

    Shen Luan Yu; Yan Yun Li; Zhen Rong Dong; Juan Ni Zhang; Qi Li; Jing Xing Gao

    2011-01-01

    Novel chiral PN4-type multidentate aminophosphine ligands have been successfully synthesized by Schiff-base condensation of bis(o-formylphenyl)phenylphosphane and various chiral amino-sulfonamides. Their structures were fully characterized by IR, EI-MS and NMR. The catalytic systems, prepared in situ from the multidentate ligands and iridium(I) complexes, showed high activity in asymmetric transfer hydrogenation of propiophenone in 2-propanol solution, leading to corresponding optical alcohol with up to 75% ee.

  14. Sonochemiluminescence of lucigenin: Evidence of superoxide radical anion formation by ultrasonic irradiation

    Science.gov (United States)

    Matsuoka, Masanori; Takahashi, Fumiki; Asakura, Yoshiyuki; Jin, Jiye

    2016-07-01

    The sonochemiluminescence (SCL) behavior of lucigenin (Luc2+) has been studied in aqueous solutions irradiated with 500 kHz ultrasound. Compared with the SCL of a luminol system, a tremendously increased SCL intensity is observed from 50 µM Luc2+ aqueous solution (pH =11) when small amounts of coreactants such as 2-propanol coexist. It is shown that SCL intensity strongly depends on the presence of dissolved gases such as air, O2, N2, and Ar. The highest SCL intensity is obtained in an O2-saturated solution, indicating that molecular oxygen is required to generate SCL. Since SCL intensity is quenched completely in the presence of superoxide dismutase (SOD), an enzyme that can catalyze the disproportionation of O2 •-, the generation of O2 •- in the ultrasonic reaction field is important in the SCL of Luc2+. In this work, the evidence of O2 •- production is examined by a spectrofluorometric method using 2-(2-pyridyl)benzothiazoline as the fluorescent probe. The results indicate that the yield of O2 •- is markedly increased in the O2-saturated solutions when a small amount of 2-propanol coexists, which is consistent with the results of SCL measurements. 2-Propanol in the interfacial region of a cavitation bubble reacts with a hydroxyl radical (•OH) to form a 2-propanol radical, CH3C•(OH)CH3, which can subsequently react with dissolved oxygen to generate O2 •-. The most likely pathways for SCL as well as the spatial distribution of SCL in a microreactor are discussed in this study.

  15. Design, synthesis and antifungal activity of novel triazole derivatives

    Institute of Scientific and Technical Information of China (English)

    Qing lie Zhao; Yan Song; Hong Gang Hu; Shi Chong Yu; Qiu Ye Wu

    2007-01-01

    Twenty-three 1 -(1H-1,2,4-triazole-1-yl)-2-(2,4-difluorophenyl)-3-(N-cycloproyl-N-substituted-amino)-2-propanols were designed and synthesized on the basis of the active site of lanosterol 14α-demethylase.In vitro antifungal activities showed that some of the title compounds had higher antifungal activity and broader antifungal spectrum than fluconazole.

  16. Thermal Decomposition Reaction of Acetophenone Cyclic Diperoxide in Solvents of Different Physicochemical Properties

    Directory of Open Access Journals (Sweden)

    C. M. Mateo

    2000-03-01

    Full Text Available The thermal decomposition reaction of acetophenone cyclic diperoxide (trans-3,6-dimethyl-3,6-diphenyl-1,2,4,5-tetroxane; APDP at the initial concentration of c.a. 0.01 mol kg-1 and temperature ranges of 135.5 to 185.0° C has been investigated in dioxane and acetonitrile solutions, and in an 2-propanol/benzene mixture.

  17. Kinetics and mechanism of photolysis and TiO2 photocatalysis of triclosan.

    Science.gov (United States)

    Son, Hyun-Seok; Ko, Gwangpyo; Zoh, Kyung-Duk

    2009-07-30

    The degradations of triclosan (5-chloro-2-(2,4-dichlorophenoxy)-phenol), a potent broad-spectrum antimicrobial agent, were compared in TiO2-only in the dark condition, photolysis, and TiO2 photocatalysis with a UV-A lamp. TiO2 photocatalysis more effectively degraded and mineralized triclosan compared to TiO2-only and photolysis conditions. While triclosan removed only 30% by TiO2-only condition within 20 min, the triclosan degradation in photolysis and photocatalysis at the same time was 75 and 82%, respectively, and TOC removal was significantly higher in photocatalysis than in photolysis. The data of kinetics showed that triclosan adsorption onto TiO2 was fitted to Langmuir isotherm, and TiO2 photocatalysis was fitted to Langmuir-Hinshelwood model (b=27.99 mM(-1), K(triclosan)=9.49 mM(-1)). The neutral range of pH was favorable to photocatalysis due to the charge effect between TiO2 and triclosan. The addition of 2-propanol, a radical scavenger, significantly reduced the degradation of triclosan both in photolysis and photocatalysis. Dioxin-type intermediates such as dibenzo-dichloro-p-dioxin (DCDD), dibenzo-p-dioxin were produced in photolysis with and without 2-propanol, and also in photocatalysis with 2-propanol, but these intermediates were not detected in photocatalysis without 2-propanol. This result indicates that the photocatalytic degradation of triclosan is mainly achieved by radicals, and these radicals can further degrade dioxin-type intermediates once they are produced in photocatalysis.

  18. Nucleation Kinetics of Cis-Entacapone

    OpenAIRE

    Škalec Šamec, D.; Meštrović, E.; Sander, A.

    2012-01-01

    The solubility curve and the metastable zone width for the system cis-entacapone –2-propanol have been determined in defined process conditions. These results along with values of induction period for the constant feed concentration at different levels of supersaturation were used for evaluating interfacial energy according to the classical nucleation theory. The results obtained were used for calculation of the critical nucleus size, nucleation rate, and prediction of crystal growth mecha...

  19. Conversion of alcohols ({alpha}-methylated series) on AlPO{sub 4} catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Campelo, J.M.; Garcia, A.; Herencia, J.F. [Universidad de Cordoba (Spain)] [and others

    1995-02-01

    The conversion (dehydration/dehydrogenation) of alcohols in {alpha}-methylated series (methanol, ethanol, 2-propanol, and tert-butanol) on AlPO{sub 4} catalysts differently prepared has been studied by microcatalytic pulse reactor technique at different temperatures and flow rates. The kinetic parameters have been obtained by analysis of the data through the Bassett-Habgood equation. Dehydration to ether and/or olefin is the major reaction process. Dehydrogenation product was only scarcely found in 2-propanol conversion. The influence of the reaction temperature upon the conversion of alcohols and the selectivities of the products was investigated. Activity increases as a function of surface acidity of the AlPO{sub 4} catalyst as well as with the {alpha}-substitution in the alcohol. Moreover, selectivity studies indicated that ethanol and 2-propanol dehydration follows a combination pathway of parallel and consecutive reactions. A good correlation between the results of dehydration conversion and acid properties, gas-chromatographically measured through the irreversible adsorption of pyridine (473 and 573 K) and 2,6-dimethylpyridine (573 K), is observed. Also, activity poisoning results indicated that Broensted acid sites of AlPO{sub 4} catalyst participated in dehydradation processes, thus strengthening the carbenium ion reaction pathway in AlPO{sub 4} catalysts. 49 refs., 3 figs., 4 tabs.

  20. Preparation of a Titania/X-Zeolite/Porous Glass Composite Photocatalyst Using Hydrothermal and Drop Coating Processes

    Directory of Open Access Journals (Sweden)

    Atsuo Yasumori

    2015-01-01

    Full Text Available Combinations of TiO2 photocatalysts and various adsorbents have been widely studied for the adsorption and photocatalytic decomposition of gaseous pollutants such as volatile organic compounds (VOCs. Herein, a TiO2-zeolite-porous glass composite was prepared using melt-quenching and partial sintering, hydrothermal treatment, and drop coating for preparation of the porous glass support and X-zeolite and their combination with TiO2, respectively. The obtained composite comprised anatase phase TiO2, X-zeolite, and the porous glass support, which were combined at the micro to nanometer scales. The composite had a relatively high specific surface area of approximately 25 m2/g and exhibited a good adsorption capacity for 2-propanol. These data indicated that utilization of this particular phase-separated glass as the support was appropriate for the formation of the bulk photocatalyst-adsorbent composite. Importantly, the photocatalytic decomposition of adsorbed 2-propanol proceeded under UV light irradiation. The 2-propanol was oxidized to acetone and then trapped by the X-zeolite rather than being released to the atmosphere. Consequently, it was demonstrated that the micrometer-scaled combination of TiO2 and zeolite in the bulk form is very useful for achieving both the removal of gaseous organic pollutants and decreasing the emission of harmful intermediates.

  1. Gamma-irradiation synthesis of iron oxide nanoparticles in the presence of PEO, PVP or CTAB

    Science.gov (United States)

    Jurkin, Tanja; Gotić, Marijan; Štefanić, Goran; Pucić, Irina

    2016-07-01

    Black hydrogels were synthesized using γ-irradiation of poly(ethylene oxide) (PEO)/iron(III) chloride precursor solutions. The magnetic properties of such hydrogels were improved by adding 2-propanol as a hydroxyl scavenger and/or NaBH4 as a strong chemical reducing agent; however, the rigidity and compactness of thus synthesized PEO hydrogels deteriorated. The magnetic suspension containing pure magnetite nanoparticles was obtained using γ-irradiation of an Fe(III)/PEO deoxygenated aqueous solution in the presence of 2-propanol and NaBH4. The γ-irradiation of an iron(III) chloride aqueous precursor solution in the presence of PVP produced a magnetic suspension due to the formation of a small amount of δ-FeOOH (feroxyhyte). The γ-irradiation of Fe(III)/CTAB (cetyltrimethylammonium bromide) aqueous solutions favored the formation of goethite. γ-irradiation in the presence of 2-propanol increased the yield of rod-like goethite nanoparticles. A small amount of δ-FeOOH found in the Fe(III)/PVP and Fe(III)/CTAB suspensions suggests the formation of Fe(OH)2upon γ-irradiation, which then under atmospheric conditions rapidly oxidized into δ-FeOOH.

  2. Efficient photocatalytic degradation of organics present in gas and liquid phases using Pt-TiO2/Zeolite (H-ZSM).

    Science.gov (United States)

    Neppolian, B; Mine, Shinya; Horiuchi, Yu; Bianchi, C L; Matsuoka, M; Dionysiou, D D; Anpo, M

    2016-06-01

    TiO2-encapsulated H-ZSM photocatalysts were prepared by physical mixing of TiO2 and zeolites. Pt was immobilized on the surface of the TiO2-encapsulated zeolite (H-ZSM) catalysts by a simple photochemical reduction method. Different weight ratios of both TiO2 and Pt were hybridized with H-ZSM and the catalytic performance of the prepared catalysts was investigated for 2-propanol oxidation in liquid phase and acetaldehyde in gas phase reaction. Around 5-10 wt% TiO2-encapsulated H-ZSM catalysts was found to be optimal amount for the effective oxidation of the organics. Prior to light irradiation, Pt-TiO2-H-ZSM showed considerable amount of catalytic degradation of 2-propanol in the dark, forming acetone as an intermediate. In this study, Pt has played a major and important role on the total oxidation of 2-propanol as well as acetaldehyde. As a result, no residual organics were present in the pores of the zeolites. The catalysts could be reused more than three times without losing their catalytic activity in both phases. The Pt-TiO2-H-ZSM photocatalysts could overcome the problem of strong adsorption of organics in the zeolite pores (after the reaction). Thus, Pt-TiO2-H-ZSM can be used as a potential catalyst for both liquid and gas phase oxidation of organic pollutants.

  3. Rapid Estimation of Tocopherol Content in Linseed and Sunflower Oils-Reactivity and Assay

    Directory of Open Access Journals (Sweden)

    Tjaša Prevc

    2015-08-01

    Full Text Available The reactivity of tocopherols with 2,2-diphenyl-1-picrylhydrazyl (DPPH was studied in model systems in order to establish a method for quantifying vitamin E in plant oils. The method was optimized with respect to solvent composition of the assay medium, which has a large influence on the course of reaction of tocopherols with DPPH. The rate of reaction of α-tocopherol with DPPH is higher than that of γ-tocopherol in both protic and aprotic solvents. In ethyl acetate, routinely applied for the analysis of antioxidant potential (AOP of plant oils, reactions of tocopherols with DPPH are slower and concentration of tocopherols in the assay has a large influence on their molar reactivity. In 2-propanol, however, two electrons are exchanged for both α- and γ-tocopherols, independent of their concentration. 2-propanol is not toxic and is fully compatible with polypropylene labware. The chromatographically determined content of tocopherols and their molar reactivity in the DPPH assay reveal that only tocopherols contribute to the AOP of sunflower oil, whereas the contribution of tocopherols to the AOP of linseed oil is 75%. The DPPH assay in 2-propanol can be applied for rapid and cheap estimation of vitamin E content in plant oils where tocopherols are major antioxidants.

  4. Photo-oxidation of organic compounds in liquid low-level mixed wastes at the INEL

    Energy Technology Data Exchange (ETDEWEB)

    Gering, K.L.; Schwendiman, G.L.

    1996-08-01

    A bench-scale oxidation apparatus is implemented to study the effectiveness of using an artificial ultraviolet source, a 175-watt medium pressure mercury vapor lamp, to enhance the destruction of organic contaminants in water with chemical oxidants. The waste streams used in this study are samples or surrogates of mixed wastes at the Idaho National Engineering Laboratory. The contaminants that are investigated include methylene chloride, 1,1,1-trichlorethane, 1, 1-dichlororethane, acetone, 2-propanol, and ethylenediamine tetraacetic acid. We focus on H{sub 2}O{sub 2}-based oxidizers for our treatment scheme, which include the UV/H{sub 2}O{sub 2} system, the dark Fenton system (H{sub 2}O{sub 2}/Fe{sup 2+}), and the photo- assisted Fenton system (UV/H{sub 2}O{sub 2}/Fe{sup 3+}) is used in particular. Variables include concentration of the chemical oxidizer, concentration of the organic contaminant, and the elapsed reaction time. Results indicate that the photo-assisted Fenton system provides the best overall performance of the oxidizing systems listed above, where decreases in concentrations of methylene chloride, 1,1,1- trichloroethane, 1,1-dichlororethane, 2-propanol, and ethylenediamine tetraacetic acid were seen. However, UV-oxidation treatment provided no measurable benefit for a mixed waste containing acetone in the presence of 2-propanol.

  5. Influence of solvent on the structural and morphological properties of AgI particles prepared using ultrasonic spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Validzic, Ivana Lj.; Jokanovic, Vukoman [Vinca Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia); Uskokovic, Dragan P. [Institute of Technical Sciences of the Serbian Academy of Sciences and Arts, Knez Mihailova 35/IV, 11001 Belgrade (Serbia); Nedeljkovic, Jovan M. [Vinca Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia)], E-mail: jovned@vin.bg.ac.yu

    2008-01-15

    Silver iodide particles were synthesized in the process of ultrasonic spray pyrolysis using aqueous solutions of thermodynamically stable silver iodide clusters as precursor. The AgI particles were collected in solvents of different polarities such as water, 2-propanol and toluene. In order to study influence of solvent and aging time on the morphological and structural properties of the AgI particles ultra-filtration was employed to isolate solid material from solution. The scanning electron microscopy showed that morphology of the AgI particles is different for different solvents. The AgI particles with hexagonal/triangular shape were obtained in water and toluene, while in 2-propanol hollow spheres were formed. The X-ray diffraction analysis, besides wurtzite hexagonal and zinc blende cubic phases, revealed appearance of tetragonal high-pressure AgI modification for sample collected in toluene and for sample aged in 2-propanol. The aging in toluene induced transformation of all three modifications into single phase with one preferred orientation.

  6. Alcohol--Induced Polyelectrolyte-Surfactant Complex Coacervate Systems: Characterization and Applications in Enzyme and Protein Extraction

    Science.gov (United States)

    Nejati Moshtaghin, Mahboubeh

    of FA, oppositely charged amphiphiles (surfactant-polyelectrolyte), and the charge ratio of the surfactant-polyelectrolyte on the extent of coacervation have been investigated. Furthermore, the chemical composition of each phase formed in the coacervate system was determined as a function of HFIP percentage. Phase diagrams of HFIP-PMA-CTAB and 2-propanol-PMA-CTAB were studied. The phase separation occurs over a wide range of polyelectrolyte, surfactant and alcohol concentration. In addition, a study of the dependence of coacervate volume on phase composition in different system (as defined by concentrations and mole charge ratio of amphihiles and alcohols) provided useful insight about possible underlying interactions and mechanisms. It has been concluded that neutralization favors coacervation in both systems. However, according to the compositional analysis of both HFIP and 2-propanol SPCC system, it seems that coacervation mechanisms are different. In Chapter III the properties of 2-propanol--SPCC, with analogous surfactant (CTAB) and polyelectrolyte (PMA) used in Chapter II, will be investigated. In particular, we are interested in examining the difference between the phase separation characteristics of the coacervates induced by 2-propanol and HFIP as coacervator. For this purpose, the phase behavior and the chemical composition of the phases will be analyzed as a function of 2-propanol and constituents concentrations. Chapter IV contains results of our investigations on the activity of a model enzyme (Trypsin) in 2-propanol- and FA-induced SPCC system. These investigations will facilitate understanding whether the aliphatic alcohol, AA- and FA-induced SPCC system denature the model enzymes. Such investigations also help in evaluation of the applicability of the coacervate systems developed in this work in proteomics where the proteolytic activity of enzymes is used for protein digestion. Finally, in Chapter V, the efficiency of the coacervate system (2-propanol

  7. Chemical strategies for modifications of the solar cell process, from wafering to emitter diffusion; Chemische Ansaetze zur Neuordnung des Solarzellenprozesses ausgehend vom Wafering bis hin zur Emitterdiffusion

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Kuno

    2009-11-06

    The paper describes the classic standard industrial solar cell based on monocrystalline silicon and describes new methods of fabrication. The first is an alternative wafering concept using laser microjet cutting instead of multiwire cutting. This method originally uses pure, deionized water; it was modified so that the liquid jet will not only be a liquid light conductor but also a transport medium for etching fluids supporting thermal abrasion of silicon by the laser jet. Two etching fluids were tested experimentally; it was found that water-free fluids based on perfluorinated solvents with very slight additions of gaseous chlorine are superior to all other options. In the second section, the wet chemical process steps between wafering and emitter diffusion (i.e. the first high-temperature step) was to be modified. Alternatives to 2-propanol were to be found in the experimental part. Purification after texturing was to be rationalized in order to reduce the process cost, either by using less chemical substances or by achieving shorter process times. 1-pentanol and p-toluolsulfonic acid were identified as two potential alternatives to 2-propanol as texture additives. Finally, it could be shown that wire-cut substrates processed with the new texturing agents have higher mechanical stabilities than substrates used with the classic texturing agent 2-propanol. [German] Im ersten Kapitel wird die klassische Standard-Industrie-Solarzelle auf der Basis monokristallinen Siliziums vorgestellt. Der bisherige Herstellungsprozess der Standard-Industrie-Solarzelle, der in wesentlichen Teilen darauf abzielt, diese Verluste zu minimieren, dient als Referenz fuer die Entwicklung neuer Fertigungsverfahren, wie sie in dieser Arbeit vorgestellt werden. Den ersten thematischen Schwerpunkt bildet die Entwicklung eines alternativen Wafering-Konzeptes zum Multi-Drahtsaegen. Die Basis des neuen, hier vorgestellten Wafering-Prozesses bildet das Laser-Micro-Jet-Verfahren. Dieses System

  8. Contribution of liver alcohol dehydrogenase to metabolism of alcohols in rats.

    Science.gov (United States)

    Plapp, Bryce V; Leidal, Kevin G; Murch, Bruce P; Green, David W

    2015-06-05

    The kinetics of oxidation of various alcohols by purified rat liver alcohol dehydrogenase (ADH) were compared with the kinetics of elimination of the alcohols in rats in order to investigate the roles of ADH and other factors that contribute to the rates of metabolism of alcohols. Primary alcohols (ethanol, 1-propanol, 1-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol) and diols (1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol) were eliminated in rats with zero-order kinetics at doses of 5-20 mmol/kg. Ethanol was eliminated most rapidly, at 7.9 mmol/kgh. Secondary alcohols (2-propanol-d7, 2-propanol, 2-butanol, 3-pentanol, cyclopentanol, cyclohexanol) were eliminated with first order kinetics at doses of 5-10 mmol/kg, and the corresponding ketones were formed and slowly eliminated with zero or first order kinetics. The rates of elimination of various alcohols were inhibited on average 73% (55% for 2-propanol to 90% for ethanol) by 1 mmol/kg of 4-methylpyrazole, a good inhibitor of ADH, indicating a major role for ADH in the metabolism of the alcohols. The Michaelis kinetic constants from in vitro studies (pH 7.3, 37 °C) with isolated rat liver enzyme were used to calculate the expected relative rates of metabolism in rats. The rates of elimination generally increased with increased activity of ADH, but a maximum rate of 6±1 mmol/kg h was observed for the best substrates, suggesting that ADH activity is not solely rate-limiting. Because secondary alcohols only require one NAD(+) for the conversion to ketones whereas primary alcohols require two equivalents of NAD(+) for oxidation to the carboxylic acids, it appears that the rate of oxidation of NADH to NAD(+) is not a major limiting factor for metabolism of these alcohols, but the rate-limiting factors are yet to be identified.

  9. Silicon nanowire arrays as learning chemical vapour classifiers

    Energy Technology Data Exchange (ETDEWEB)

    Niskanen, A O; Colli, A; White, R; Li, H W; Spigone, E; Kivioja, J M, E-mail: antti.niskanen@nokia.com [Nokia Research Center, Broers Building, 21 JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom)

    2011-07-22

    Nanowire field-effect transistors are a promising class of devices for various sensing applications. Apart from detecting individual chemical or biological analytes, it is especially interesting to use multiple selective sensors to look at their collective response in order to perform classification into predetermined categories. We show that non-functionalised silicon nanowire arrays can be used to robustly classify different chemical vapours using simple statistical machine learning methods. We were able to distinguish between acetone, ethanol and water with 100% accuracy while methanol, ethanol and 2-propanol were classified with 96% accuracy in ambient conditions.

  10. Investigación de la resolución cinética eco-compatible de R/S-ketoprofeno

    OpenAIRE

    Toledo, María Victoria; José, Carla; Theiller, Mariela; Gambaro, Luis A.; Collins, Sebastián E.; Briand, Laura E.

    2015-01-01

    Se llevó a cabo la esterificación de R/S-ketoprofeno empleando metanol, etanol, 1- y 2-propanol como reactivos y solventes catalizada con el biocatalizador comercial Novozym® 435. Se estudió la interacción de los alcoholes con el biocatalizador mediante diversas técnicas espectroscópicas. Los resultados evidenciaron la disolución del soporte polimérico, la pérdida de proteína activa, la fuerte adsorción de los alcoholes, la modificación de la estructura secundaria de la proteína y el alisado ...

  11. Design, synthesis, and antifungal activities of novel triazole derivatives containing the benzyl group.

    Science.gov (United States)

    Xu, Kehan; Huang, Lei; Xu, Zheng; Wang, Yanwei; Bai, Guojing; Wu, Qiuye; Wang, Xiaoyan; Yu, Shichong; Jiang, Yuanying

    2015-01-01

    In previous studies undertaken by our group, a series of 1-(1H-1,2,4-triazole-1-yl)-2-(2,4-difluorophenyl)-3-substituted-2-propanols (1a-r), which were analogs of fluconazole, was designed and synthesized by click chemistry. In the study reported here, the in vitro antifungal activities of all the target compounds were evaluated against eight human pathogenic fungi. Compounds 1a, 1q, and 1r showed the more antifungal activity than the others.

  12. New Chiral Metal Cluster Systems for Catalytic Asymmetric Syntheses of Chiral Alcohols

    Institute of Scientific and Technical Information of China (English)

    LI Yan-yun; CHEN Jian-shan; YANG Chuan-bo; DONG Zhen-rong; LI Bao-zhu; ZHANG Hui; GAO Jing-xing; TAKAO Ikariya

    2004-01-01

    The efficient chiral Ru3(CO)12 systems were prepared in situ from Ru3(CO)12 and various chiral diiminoor diamino-diphosphine tetradentate ligands. The systems have been used for the asymmetric transfer hydrogenation of propiophenone in 2-propanol, leading to 1-phenyl-1-propanol in a 98% yield and 96% e.e. The IR study suggests that the carbonyl hydride anion [HRu3(CO)11]- most probably exists as a principal species under the reaction conditions. The high chiral efficiency may be due to the synergetic effect produced by the neighboring ruthenium atoms and a special chiral micro-environment involving the polydentate ligand and the Ru3 framework.

  13. Preparation of Cyclic Urethanes from Amino Alcohols and Carbon Dioxide Using Ionic Liquid Catalysts with Alkali Metal Promoters

    Directory of Open Access Journals (Sweden)

    Masahiko Arai

    2006-10-01

    Full Text Available Several ionic liquids were applied as catalysts for the synthesis of cyclicurethanes from amino alcohols and pressurized CO2 in the presence of alkali metalcompounds as promoters. A comparative study was made for the catalytic performanceusing different ionic liquids, substrates, promoters, and pressures. The optimum catalyticsystem was BMIM-Br promoted by K2CO3, which, for 1-amino-2-propanol, produced cyclicurethane in 40% yield with a smaller yield of substituted cyclic urea and no oligomericbyproducts. For other amino alcohols, cyclic urethanes, cyclic ureas, and/or undesiredbyproducts were produced in different yields depending on the substrates used. Possiblereaction mechanisms are proposed.

  14. Ion-neutral reactions in the ion source of a mixture of CO2/CH3OH, CO2/C2H5OH, and CO2/2-C3H7OH by packed capillary supercritical fluid chromatography-mass spectrometry (SFC-MS).

    Science.gov (United States)

    Ekeberg, Dag; Jablonska-Jentoft, Anja M

    2007-12-01

    Ion neutral reactions in the gas phase in mixtures of ROH/CO(2), R = CH(3), C(2)H(5), and 2-C(3)H(7) were studied by supercritical fluid chromatography-mass spectrometry (SFC-MS). Three main reaction series were found for this system; ionization followed by alpha-cleavage, formation of clusters, and formation of protonated dialkyl ethers from the corresponding alcohol. The ion chemistries were similar for the three alcohols, but that of 2-propanol was somewhat more complex.

  15. Improved regioselectivity in pyrazole formation through the use of fluorinated alcohols as solvents: synthesis and biological activity of fluorinated tebufenpyrad analogs.

    Science.gov (United States)

    Fustero, Santos; Román, Raquel; Sanz-Cervera, Juan F; Simón-Fuentes, Antonio; Cuñat, Ana C; Villanova, Salvador; Murguía, Marcelo

    2008-05-01

    The preparation of N-methylpyrazoles is usually accomplished through reaction of a suitable 1,3-diketone with methylhydrazine in ethanol as the solvent. This strategy, however, leads to the formation of regioisomeric mixtures of N-methylpyrazoles, which sometimes are difficult to separate. We have determined that the use of fluorinated alcohols such as 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as solvents dramatically increases the regioselectivity in the pyrazole formation, and we have used this modification in a straightforward synthesis of fluorinated analogs of Tebufenpyrad with acaricide activity.

  16. Ionic association and solvation of the ionic liquid 1-hexyl-3-methylimidazolium chloride in molecular solvents revealed by vapor pressure osmometry, conductometry, volumetry, and acoustic measurements.

    Science.gov (United States)

    Sadeghi, Rahmat; Ebrahimi, Nosaibah

    2011-11-17

    A systematic study of osmotic coefficient, conductivity, volumetric and acoustic properties of solutions of ionic liquid 1-hexyl-3-methylimidazolium chloride ([C(6)mim][Cl]) in various molecular solvents has been made at different temperatures in order to study of ionic association and solvation behavior of [C(6)mim][Cl] in different solutions. Precise measurements on electrical conductances of solutions of [C(6)mim][Cl] in water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and acetonitrile at 293.15, 298.15, and 303.15 K are reported and analyzed with Barthel's low-concentration chemical model (lcCM) to obtain the limiting molar conductivities and association constants of this ionic liquid in the investigated solvents. Strong ion pairing was found for the ionic liquid in 2-propanol, 1-butanol, and 1-propanol, whereas ion association in acetonitrile, methanol and ethanol is rather weak and in water the ionic liquid is fully dissociated. In the second part of this work, the apparent molar volumes and isentropic compressibilities of [C(6)mim][Cl] in water, methanol, ethanol, acetonitrile, 1-propanol, 2-propanol, and 1-butanol are obtained at the 288.15-313.15 K temperature range at 5 K intervals at atmospheric pressure from the precise measurements of density and sound velocity. The infinite dilution apparent molar volume and isentropic compressibility values of the free ions and ion pairs of [C(6)mim][Cl] in the investigated solvents as well as the excess molar volume of the investigated solutions are determined and their variations with temperature and type of solvents are also studied. Finally, the experimental measurements of osmotic coefficient at 318.15 K for binary solutions of [C(6)mim][Cl] in water, methanol, ethanol, 2-propanol, and acetonitrile are taken using the vapor pressure osmometry (VPO) method and from which the values of the solvent activity, vapor pressure, activity coefficients, and Gibbs free energies are calculated. The results are

  17. Ultrasonic and Volumetric Investigations of -Butyrolactone with Aliphatic Alcohols

    Directory of Open Access Journals (Sweden)

    Amara Jyothi Koppula

    2014-08-01

    Full Text Available Densities ( and speeds of sound (u have been determined for the binary liquid mixtures of -butyrolactone (GBL with 1-propanol (1-Pro, 2-propanol (2-Pro, 1-butanol (1-But and 2-butanol (2-But at 303.15, 308.15, and 313.15 K and entire composition range. From the experimental results, the excess molar volume (V E , and deviation in isentropic compressibility (s were calculated. The computed properties have been fitted to a Redlich-Kister type polynomial equation to derive binary coefficients and standard deviations.

  18. Deracemization of Secondary Alcohols by using a Single Alcohol Dehydrogenase

    KAUST Repository

    Karume, Ibrahim

    2016-03-01

    © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. We developed a single-enzyme-mediated two-step approach for deracemization of secondary alcohols. A single mutant of Thermoanaerobacter ethanolicus secondary alcohol dehydrogenase enables the nonstereoselective oxidation of racemic alcohols to ketones, followed by a stereoselective reduction process. Varying the amounts of acetone and 2-propanol cosubstrates controls the stereoselectivities of the consecutive oxidation and reduction reactions, respectively. We used one enzyme to accomplish the deracemization of secondary alcohols with up to >99% ee and >99.5% recovery in one pot and without the need to isolate the prochiral ketone intermediate.

  19. Pulmonary Toxicity of Perfluorinated Silane-Based Nanofilm Spray Products: Solvent Dependency

    DEFF Research Database (Denmark)

    Nørgaard, Asger Wisti; Hansen, Jitka S.; Sørli, Jorid Birkelund;

    2014-01-01

    A number of cases of pulmonary injury by use of aerosolized surface coating products have been reported worldwide. The aerosol from a commercial alcohol-based nanofilm product (NFP) for coating of nonabsorbing surfaces was found to induce severe lung damage in a recent mouse bioassay. The NFP...... volume was observed after 13 and 9min, respectively; thus, the tidal volume was affected by increase of the chain length. This was confirmed in vitro by investigating lung surfactant function after addition of POTS in different solvents. The addition of vaporized methanol, 2-propanol, or acetone...

  20. Explosion and explosives. Volume 32, Number 5, 1971

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    The following topics are discussed: CMDB propellants with high pressure exponent; the thermal decomposition of phenylnitromethane in 2-propanol; double exposed flash x-ray photographic observation on detonation of coal mining explosions; detonation of condensed multiple components about detonation characteristics of three liquid explosives; synthesis of N,N'-bis (2,4,6-trinitro-3-glycidoxyphenyl)-ethylene dinitramine; resistance characteristics of electric primer containing conductive particles; and formation of Meisenheimer's complex by adding an aqueous sodium hydroxide to the reaction product of epoxy compound with picric acid.

  1. Excess volumes of binary mixtures of 1,3-dichloropropane with isomeric butanols at 298. 15 and 313. 15 K

    Energy Technology Data Exchange (ETDEWEB)

    Lafuente, C.; Pardo, J.; Rodriguez, V.; Royo, F.M.; Urieta, J.S. (Univ. de Zargoza (Spain). Dept. de Quimica Organica-Quimica Fisica)

    1993-10-01

    Excess molar volumes, V[sub m][sup E], for binary mixtures of 1,3-dichloropropane with 1-butanol, 2-butanol, 2-methyl-1-propanol, and 2-methyl-2-propanol have been determined from density measurements at 298.15 and 313.15 K by means of an Anton Paar DMA-58 vibrating tube densimeter. V[sub m][sup E] is positive over the whole composition range except for mixtures containing 1-butanol and 2-methyl-1-propanol at 298.15 K in which V[sub m][sup E] shows negative values at low mole fractions of dichloroalkane.

  2. Macroporous Titania Monolith Prepared via Sol-gel Process with Polymer Foam as the Template

    Institute of Scientific and Technical Information of China (English)

    REN, Jian; DU, Zhong-Jie; ZHANG, Chen; LI, Hang-Quan

    2006-01-01

    Macroporous titania monoliths were prepared via sol-gel method using polymer foam as templates. The polymer foam polymerized via concentrated emulsion polymerization was immerged in a solution of titanium(Ⅳ) isopropoxide in 2-propanol, which underwent a sol-gel process. The organic components were subsequently removed by calcination. The effects of various parameters, including the nature of the monomer, the volume fraction of dispersed phase of the concentrated emulsion, and concentration of the sol-gel solution were investigated. The SEM micrographs of the macroporous titania monoliths thus obtained showed that the porous structure of the final material was effectively controllable.

  3. Measurement and correlation of solubility of trans-resveratrol in 11 solvents at T = (278.2, 288.2, 298.2, 308.2, and 318.2) K

    Energy Technology Data Exchange (ETDEWEB)

    Sun Xilan; Peng Bin [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China); Yan Weidong [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China)], E-mail: yanweidong@zju.edu.cn

    2008-04-15

    The solubilities of trans-resveratrol in methanol, ethanol, 1-propanol, 2- propanol, 1-butanol, 1-pentanol, 1-hexanol, ethyl acetate, tetrahydrofuran, acetone, and water (pH 6.0) solvents were measured at T = (278.2, 288.2, 298.2, 308.2, and 318.2) K. The solubilities of trans-resveratrol in selected solvents increase with temperature, but decrease with increasing the number of carbon in alcohol solvents. The experimental data were correlated using a thermodynamic equation.

  4. The plasma membrane proteome of germinating barley embryos

    DEFF Research Database (Denmark)

    Hynek, Radovan; Svensson, Birte; Jensen, O.N.;

    2009-01-01

    with amphiphilicity and low abundance of membrane proteins. A fraction enriched in plasma membranes was prepared from embryos dissected from 18 h germinated barley seeds using aqueous two-phase partitioning. Reversed-phase chromatography on C-4 resin performed in micro-spin columns with stepwise elution by 2-propanol...... was used to reduce soluble protein contamination and enrich for hydrophobic proteins. Sixty-one proteins in 14 SDS-PAGE bands were identified by LC-MS/MS and database searches. The identifications provide new insight into the plasma membrane functions in seed germination....

  5. Synthesis and Structure of a New Dinuclear Uranyl Complex

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With a heptadentate compartmental Schiff-base ligand H3L (1, 3-di[o-(salicylimino) ph-enoxyl]-2-propanol), a new binuclear diuranyl complex [(UO2)2L(OH)]?3DMF, C38H45N5O13U2, was synthesized and the crystal structure was determined by X-ray diffraction techniques. The coordination geometry are two pentagonal bipyramids. In each pentagon four kinds of U-O (phenoxido, hydroxo, alkoxo and ether oxo) bonds are discussed.

  6. Thermal effects of added propanol on the helix-coil transition of (Pro-Pro-Gly) 10 in D 2O solution: An NMR study

    Science.gov (United States)

    Kai, Tsutomu; Uchiyama, Susumu; Nishi, Yoshinori; Kobayashi, Yuji; Tomiyama, Tetsuo

    2010-05-01

    The conformational transition of collagen model peptide, (Pro-Pro-Gly) 10, from the triple helical structure to the statistical coil was observed in various aqueous alcohol solutions by NMR measurements. In methanol or ethanol solution, the thermal transition temperature, Tm, of the peptide increased regularly with the concentration of alcohols. In 1- or 2-propanol, however, Tm first decreased and then increased steeply, in apparent contrast to the general trend that the addition of alcohol on aqueous solution increases the stability of ordered structure of polypeptides. This exceptional behavior of the collagen model peptide in propanols might provide a clue to investigate the mechanism of stabilization of protein conformation.

  7. Organosilicon Polymeric Nonlinear Optical Materials for Optical Switching and Modulation

    Science.gov (United States)

    1994-02-28

    bisphenol A ( DGEBA ; obtained from Shell Chemical Co., Epon 828) and 5.81 g of D03 (molar ratio = 1.0:1.1) was heated at 155 TC for 2 h under an inert...atmosphere. This epoxy prepolymer, DGEBA -D03, was washed by dispersing the prepolymer in an excess of toluene for several hours to remove the unreacted D03... DGEBA -D03 and 10.7 mL (76.9 mmole) of triethylamine in 200 mL of dry THF. The reaction was carried out in a dry-ice/2-propanol bath to keep the

  8. Towards a methanol economy: Zeolite catalyzed production of synthetic fuels

    DEFF Research Database (Denmark)

    Mentzel, Uffe Vie

    a commercial H-ZSM-5 zeolite impregnated with gallium and/or molybdenum is described. The object was to investigate if the presence of methanol in the feed could enhance the conversion of ethane, but in all cases the opposite is observed; the presence of methanol actually suppresses the conversion of ethane....... This observation is attributed to a stoichiometric reaction between ethane and the metal oxide species in the catalyst, leading to the oxidation of ethane to ethene, which is readily converted and incorporated into the products. Conversion of methanol, ethanol, 2-propanol, and 1 butanol to hydrocarbons over...

  9. Design synthesis and biological evaluation of 3-substituted triazole derivatives

    Institute of Scientific and Technical Information of China (English)

    Bao Gang Wang; Shi Chong Yu; Xiao Yun Chai; Yong Zheng Yan; Hong Gang Hu; Qiu Ye Wu

    2011-01-01

    Based on the active site of lanosterol 14α-demethylase of azole antifungal agents, sixteen l-(lH-l,2,4-triazole-l-yl)- 2-(2,4-difluorophenyl)-3-(N-n-butyl-N-l-substitutedbenzyl-4-methylene-lH-l,2,3-triazole)-2-propanols have been designed, synthesized and evaluated as antifungal agents. Results of preliminary antifungal tests against eight human pathogenic fungi in vitro showed that some of the compounds exhibited excellent activities with broad spectrum.

  10. [Characteristics of antiischemic and nootropic properties of ademol in a rat model of acute brain ischemia].

    Science.gov (United States)

    Khodakivs'kyĭ, O A

    2013-01-01

    In experiments with the rat model of acute disorder of encephalic circulation (bilateral carotid occlusion) it was found that introduction of derivate of adamantan 1-adamantiloxy-3-morfolino-2 propanol (under conventional name ademol) in the dose 2 mg/kg intraabdominal in treatment regimen (in an hour after reconstruction of insult and further 1 time every 24 hours during 21 days) was accompanied by a recovery of mnemotropic properties and is more effective than cytikolin, resulting in a decreased lethality and neurological deficiency in acute and recovery periods of insults. The data received proved the usefulness of development of ademol based cerebroprotective remedy.

  11. Molecular Biology of STLV-III and HTLV-IV

    Science.gov (United States)

    1990-08-22

    gel bands, pooled, and sedimented. The DNA pellet was resuspended in a lOp1 reaction volume containing T4 DNA ligase . Ligations were incubated...this procedure, all enzymes were from New England Biolabs, approximately 5u. of each restriction enzyme and approximately 3 Weiss u. of T4 DNA ligase were...volume 2-propanol. The fragments were re-ligated using T4 DNA ligase , in a 200pl reaction volume containing 15% PEG-8000, for 0.5-2hr at room temperature

  12. Quantification of three macrolide antibiotics in pharmaceutical lots by HPLC: Development, validation and application to a simultaneous separation

    OpenAIRE

    A. Mahmoudi; De Francia, Silvia; Boukhechem, M; Pirro, Elisa

    2016-01-01

    A new validated high performance liquid chromatographic (HPLC) method with rapid analysis time and high efficiency, for the analysis of erythromycin, azithromycin and spiramycin, under isocratic conditions with ODB RP18 as a stationary phase is described. Using an eluent composed of acetonitrile –2-methyl-2-propanol –hydrogenphosphate buffer, pH 6.5, with 1.5% triethylamine (33:7: up to 100, v/v/v), delivered at a flow-rate of 1.0 mL min-1. Ultra Violet (UV) detection is performed at 210 nm. ...

  13. MEZCLAS BINARIAS DE LÍQUIDO IÓNICO CON SOLVENTE MOLECULAR: PREDICCIÓN DEL VOLUMEN DE EXCESO MOLAR DESDE ÍNDICES DE REFRACCIÓN

    OpenAIRE

    Marlon Doney Martínez Reina; Eliseo Amado González

    2011-01-01

    El volumen de exceso molar de 30 mezclas binarias que contienen líquidos iónicos de imidazolio con diferentes solventes moleculares: (metanol, etanol, 1-propanol, 2-propanol, acetona, 2- butanona, 2-pentanona, acetato de metilo, acetato de etilo, acetato de butilo, carbonato de dimetilo, carbonato de dietilo, nitrometano, 1,3-dicloropropano y etilenglicol),se predice desde datos de índice de refracción, usando tres tipos de métodos acoplados con diferentes reglas de mezcla para el cálculo del...

  14. Enhanced Reactivity of [Hydroxy(tosyloxyiodo]benzene in Fluoroalcohol Media. Efficient Direct Synthesis of Thienyl(aryliodonium Salts

    Directory of Open Access Journals (Sweden)

    Toshifumi Dohi

    2010-03-01

    Full Text Available In this manuscript, we report clear evidence for the generation of aromatic cation radicals produced by using [hydroxy(tosyloxyiodo]benzene (HTIB in fluoroalcohol solvents such as 2,2,2-trifluoroethanol (TFE and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP. The single-electron-transfer (SET oxidation ability of HTIB to give cation radicals was first established by ESR and UV measurements. The reaction was broadly applied to various thiophenes, and unique thienyliodonium salts were directly synthesized by this method in excellent yields without the production of any harmful byproducts.

  15. Violent explosion after inadvertent mixing of nitric acid and isopropanol – Review 15 years later finds basic accident data corrupted, no evidence of broad learning

    DEFF Research Database (Denmark)

    Hedlund, Frank Huess; Folmer Nielsen, Merete; Hagen Mikkelsen, Sonja

    2014-01-01

    steel tank disintegrated with such force that fragments lodged in walls of concrete. The explosion ravaged the cellar, destroyed equipment, blew out a masonry wall and released large amounts of nitrous oxide fumes. Likely, 62% nitric acid (CAS 7697-37-2) and isopropanol (2-propanol, CAS 67-63-0) reacted...... the brewery to court for negligence, they did not report or investigate the accident, or attempt to disseminate information available to them. Today, the general literature is silent on the explosion hazards of mixing the two chemicals. The paper argues that without institutional support, learning...

  16. Steric vs. electronic effects in the Lactobacillus brevis ADH-catalyzed bioreduction of ketones.

    Science.gov (United States)

    Rodríguez, Cristina; Borzęcka, Wioleta; Sattler, Johann H; Kroutil, Wolfgang; Lavandera, Iván; Gotor, Vicente

    2014-01-28

    Lactobacillus brevis ADH (LBADH) is an alcohol dehydrogenase that is commonly employed to reduce alkyl or aryl ketones usually bearing a methyl, an ethyl or a chloromethyl as a small ketone substituent to the corresponding (R)-alcohols. Herein we have tested a series of 24 acetophenone derivatives differing in their size and electronic properties for their reduction employing LBADH. After plotting the relative activity against the measured substrate volumes we observed that apart from the substrate size other effects must be responsible for the activity obtained. Compared to acetophenone (100% relative activity), other small substrates such as propiophenone, α,α,α-trifluoroacetophenone, α-hydroxyacetophenone, and benzoylacetonitrile had relative activities lower than 30%, while medium-sized ketones such as α-bromo-, α,α-dichloro-, and α,α-dibromoacetophenone presented relative activities between 70% and 550%. Moreover, the comparison between the enzymatic activity and the obtained final conversions using an excess or just 2.5 equiv. of the hydrogen donor 2-propanol, denoted again deviations between them. These data supported that these hydrogen transfer (HT) transformations are mainly thermodynamically controlled. For instance, bulky α-halogenated derivatives could be quantitatively reduced by LBADH even employing 2.5 equiv. of 2-propanol independently of their kinetic values. Finally, we found good correlations between the IR absorption band of the carbonyl groups and the degrees of conversion obtained in these HT processes, making this simple method a convenient tool to predict the success of these transformations.

  17. Thermodynamic properties of binary liquid mixtures of diethylenetriamine with alcohols at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, Gyan Prakash, E-mail: gyan.dubey@rediffmail.com [Department of Chemistry, Kurukshetra University, Kurukshetra 136119 (India); Kumar, Krishan [Department of Chemistry, Kurukshetra University, Kurukshetra 136119 (India)

    2011-09-20

    Highlights: {yields} Thermodynamic study of diethylenetriamine + 2-methyl-1-propanol, +2-propanol or +1-butanol have been made. {yields} Excess molar volumes and isentropic compressibility were determined. {yields} Types of interactions were discussed based on derived properties. - Abstract: Densities, {rho}, viscosities, {eta}, and speeds of sound, u, were measured for the binary liquid mixtures containing diethylenetriamine with 2-methyl-1-propanol, 2-propanol and 1-butanol at 293.15, 298.15, 303.15, 308.15 and 313.15 K. From density and speed of sound data, excess molar volumes, V{sub m}{sup E} and deviations in isentropic compressibility, {Delta}{kappa}{sub s}, and speed of sound, {Delta}u have been evaluated. Viscosity data were used to compute deviations in viscosity and excess Gibbs energy of activation of viscous flow {Delta}G*{sup E} at 298.15, 303.15 and 308.15 K. A Redlich-Kister type equation was applied to fit the excess molar volumes and deviations in isentropic compressibility, speed of sound and viscosity data. The viscosity data have been correlated with the equations of Grunberg-Nissan, Tamura-Kurata, Heric-Brewer and of Hind et al. All the binary systems of the present study have negative values of excess molar volumes and deviations in isentropic compressibility over whole composition range and at all temperatures which indicates strong interactions between the components of binary mixtures.

  18. In vitro release studies of piroxicam from oil-in-water creams and hydroalcoholic gel topical formulations.

    Science.gov (United States)

    Rafiee-Tehrani, M; Mehramizi, A

    2000-04-01

    The importance of piroxicam, a therapeutic anti-inflammatory drug, is well known. Because of gastrointestinal disorders, dermatological dosage forms are recommended most. In our first studies, oil-in-water (O/W) creams of piroxicam (1% concentration) were prepared using glyceryl monostearate (GMS), stearic acid, and triethanolamine as additive ingredients. In our second studies, hydroalcoholic transparent gel formulations of this drug in a 0.5% concentration were prepared using hydroxypropylcellulose (HPC) as the gelling agent. The release of piroxicam from all formulations via dialysis through a cellulose membrane into phosphate buffer pH 6.8 at 37 degrees C was studied. The effects of additives such as propylene glycol and 2-propanol on the drug release were also investigated. The release profiles from the standpoint of diffusion-controlled processes, as well as zero-order and first-order kinetics, were evaluated, and relevant parameters, such as diffusion coefficient, permeability coefficient, and partition coefficient, were calculated. The release obeys both the diffusion mechanism and first-order kinetics. The drug release from gel formulations containing 10%, 20%, and 30% propylene glycol was decreased due to the enhancement of viscosity. However, the limpidity of these formulations was improved. Moreover, the release of drug from gel formulations containing 15% and 20% of 2-propanol was increased. These results show that a hydroalcoholic gel formulation with HPC is a more suitable preparation of piroxicam when compared with an O/W cream formulation.

  19. Self-Assembled Monolayers Get Their Final Finish via a Quasi-Langmuir-Blodgett Transfer.

    Science.gov (United States)

    Meltzer, Christian; Dietrich, Hanno; Zahn, Dirk; Peukert, Wolfgang; Braunschweig, Björn

    2015-04-28

    The growth of self-assembled monolayers (SAMs) of octadecylphosphonic acid (ODPA) molecules on α-Al2O3(0001) and subsequent dewetting of the SAMs were studied with a combination of in situ sum-frequency generation (SFG) and molecular dynamics (MD) simulations. Although SAM growth after deposition times >8 h reduces to nearly negligible values, the resultant ODPA SAMs in solution are still not in a well-ordered state with the alkyl chains in all-trans configurations. In fact, in situ SFG spectroscopy revealed a comparatively high concentration of gauche defects of the SAM in the ODPA 2-propanol solution even after a growth time of 16 h. Here, results of the MD simulations strongly suggest that defects can be caused by ODPA molecules which are not attached to the substrate but are incorporated into the SAM layer with the polar headgroup oriented into the 2-propanol solvent. This inverted adsorption geometry of additional ODPA molecules blocks adsorption sites and thus stabilizes the SAM without improving ordering to an extent that all molecules are in the all-trans configuration. While persistent in solution, the observed defects can be healed out when the SAMs are transferred from the solvent to a gas phase. During this process, a quasi-Langmuir-Blodgett transfer of molecules takes place which drives the SAM into a higher conformational state and significantly improves its quality.

  20. The mechanism of cumene hydroperoxide-dependent lipid peroxidation: the function of cytochrome P-450.

    Science.gov (United States)

    Weiss, R H; Estabrook, R W

    1986-11-15

    The addition of limiting amounts of cumene hydroperoxide to rat liver microsomes resulted in the rapid uptake of molecular oxygen, the formation of thiobarbituric acid reactive products, and the loss of hydroperoxide. The stoichiometry of lipid peroxidation and the yields of 2-phenyl-2-propanol (a major product of the reaction) and acetophenone (a minor product) observed with liver microsomes prepared from untreated rats is greater than that seen with liver microsomes from ciprofibrate-treated rats which, in turn, is greater than that observed with liver microsomes from phenobarbital-treated rats. The Km's and Vmax's of oxygen uptake varied with the type of rat liver microsomes used. Cytochrome P-450 substrates and inhibitors decreased the extents and initial rates of oxygen uptake and thiobarbituric acid reactive product formation. A mechanism is proposed involving the cytochrome P-450-catalyzed homolytic cleavage of the cumene hydroperoxide O-O bond to give the cumyloxyl radical. It is proposed that this oxygen-centered radical abstracts a hydrogen atom from an unsaturated fatty acid associated with a lipid (initiating lipid peroxidation) to give 2-phenyl-2-propanol or that the radical undergoes beta-scission to produce acetophenone and a methyl radical.

  1. Fourier-transformed infrared breath testing after ingestion of technical alcohol.

    Science.gov (United States)

    Laakso, Olli; Haapala, Matti; Pennanen, Teemu; Kuitunen, Tapio; Himberg, Jaakko-Juhani

    2007-07-01

    The study aim was to evaluate the feasibility of a Fourier-transformed infrared (FT-IR) analyzer for out-of-laboratory use by screening the exhalations of inebriated individuals, and to determine analysis quality using common breath components and solvents. Each of the 35 inebriated participants gave an acceptable sample. Because of the metabolism of 2-propanol, the subjects exhaled high concentrations of acetone in addition to ethanol. Other volatile ingredients of technical ethanol products (methyl ethyl ketone, methyl isobutyl ketone, and 2-propanol) were also detected. The lower limits of quantification for the analyzed components ranged from 1.7 to 12 microg/L in simulated breath samples. The bias was +/-2% for ethanol and -11% for methanol. Within-day and between-day coefficients of variation were <1% for ethanol and <4% for methanol. The bias of ethanol and methanol analyses due to coexisting solvents ranged from -0.8 to +2.2% and from -5.6 to +2.9%, respectively. The FT-IR method proved suitable for use outside the laboratory and fulfilled the quality criteria for analysis of solvents in breath.

  2. Reversal of elution order for profen acid enantiomers in packed-column SFC on Chiralpak AD.

    Science.gov (United States)

    Gyllenhaal, Olle; Stefansson, Morgan

    2005-05-15

    Enantiomeric separations of four 2-substituted propionic acid drugs have been studied using packed-column supercritical fluid chromatography (SFC) with amylose tris(3,5-dimethylphenylcarbamate) coated on silica as support (Chiralpak AD). Under standard conditions (i.e., flow rate, 1.5 ml/min; column temperature, 30 degrees C; back-pressure, 150 bar), the order of elution could be reversed when the polar alcohol modifier methanol in carbon dioxide was replaced by 2-propanol for ibuprofen, ketoprofen, and naproxen. For flurbiprofen, with the highest selectivity factor, no reversal was observed, although selectivity was reduced significantly with higher alcohols. Naproxen and flurbiprofen were also investigated with 2-butanol and 2-pentanol. The former showed reversal of elution order but not the latter. For higher alcohol modifiers, including 2-propanol, the peak symmetry was poor but could be improved by addition of citric acid in the alcohol modifier. These results stress the importance to investigate enantiomer elution order during the development of enantioselective methods and when chromatographic conditions are optimized. Preliminary experiments with column temperatures over the range of -15 to 45 degrees C revealed that, in a few cases, reversal took place with a change in temperature only.

  3. Enantiomeric resolution of five chiral pesticides on a Chiralpak IB-H column by SFC.

    Science.gov (United States)

    Jin, Lixia; Gao, Weiliang; Yang, Huayun; Lin, Chunmian; Liu, Weiping

    2011-10-01

    The enantiomeric separations of five chiral pesticides, diclofopmethyl, 1; benalaxy, 2; acetofenate, 3; myclobutanil, 4; and difenoconazole, 5, were conducted on a Chiralpak IB-H column by a packed-column supercritical fluid chromatography (p-SFC). All compounds, except difenoconazole and myclobutanil, were well resolved within 10 min. As the mobile phase polarity decreased through changing the percentage and the type of alcohol modifiers in the supercritical carbon dioxide (CO(2)), the retention time, the separation factors, and the resolution increased. However, based on the retention time and the resolution, the optimized separations were obtained with the mobile phase containing 10% 2-propanol for diclofop-methyl 1; benalaxy, 2; myclobutanil, 4; difenoconazole, 5; and containing 3% 2-propanol for acetofenate, 3. The optimized separation temperature was at 35°C under the supercritical fluid condition. The π-π interactions and the hydrogen bonding interactions between Chiralpak IB-H CSP and the analytes might be the main chiral discriminations on enantioseparation of these five pesticides.

  4. Electron beam induced synthesis of uranium dioxide nanoparticles: Effect of solvent composition

    Science.gov (United States)

    Rath, M. C.; Keny, S. J.; Naik, D. B.

    2016-09-01

    The effect of various compositions of solvents was investigated on the electron beam induced synthesis of uranium dioxide, UO2 nanoparticles. The synthesis was carried out at different pHs from 2 to 7 in the aqueous solutions containing 10 mM uranyl nitrate and 10% 2-propanol. The formation of UO2 nanoparticles was found to occur only in the pH range from 2.5 to 3.7. Experiments were also carried out in the aqueous solutions containing various other alcohols (10% v/v) such as methanol, ethanol, 1-propanol, 1-butanol or tert-butanol as well as in solutions containing 10 mM sodium formate at pH 3.4. The formation of UO2 nanoparticles in the aqueous solutions was found to occur only in the presence of ethanol, 1-propanol, 2-propanol or 1-butanol. It is therefore confirmed that the electron beam induced synthesis of UO2 nanoparticles strongly depends on the solvent compositions as well as the pH of the medium.

  5. A Study of the Solvation Structure of L-Leucine in Alcohol-Water Binary Solvents through Molecular Dynamics Simulations and FTIR and NMR Spectroscopy.

    Science.gov (United States)

    Takamuku, Toshiyuki; Hatomoto, Yohei; Tonegawa, Junko; Tsutsumi, Youichi; Umecky, Tatsuya

    2015-10-26

    The solvation structures of l-leucine (Leu) in aliphatic-alcohol-water and fluorinated-alcohol-water solvents are elucidated for various alcohol contents by using molecular dynamics (MD) simulations and IR, and (1) H and (13) C NMR spectroscopy. The aliphatic alcohols included methanol, ethanol, and 2-propanol, whereas the fluorinated alcohols were 2,2,2-trifluoroethanol and 1,1,1,3,3,3-hexafluoro-2-propanol. The MD results show that the hydrophobic alkyl moiety of Leu is surrounded by the alkyl or fluoroalkyl groups of the alcohol molecules. In particular, TFE and HFIP significantly solvate the alkyl group of Leu. IR spectra reveal that the Leu C-H stretching vibration blueshifts in fluorinated alcohol solutions with increasing alcohol content, whereas the vibration redshifts in aliphatic alcohol solutions. When the C-H stretching vibration blueshifts in the fluorinated alcohol solutions, the hydrogen and carbon atoms of the Leu alkyl group are magnetically shielded. Consequently, TFE and HFIP molecules may solvate the Leu alkyl group through the blue-shifting hydrogen bonds.

  6. Temperature-induced inversion of elution order in the chromatographic enantioseparation of 1,1'-bi-2-naphthol on an immobilized polysaccharide-based chiral stationary phase.

    Science.gov (United States)

    Yao, Bixia; Zhan, Fengping; Yu, Guangyan; Chen, Zhifen; Fan, Wenjing; Zeng, Xiongping; Zeng, Qingle; Weng, Wen

    2009-07-10

    In this work, the enantioseparations of 1,1'-bi-2-naphthol (BINOL) and its three derivatives were performed on an immobilized polysaccharide-based chiral stationary phase, Chiralpak IA, under normal-phase mode. The effects of the content of polar modifier in the mobile phase and the column temperature on the retention and enantioseparation were investigated in detail. Temperature-induced inversion of elution order for BINOL was observed directly when n-hexane/2-propanol (92/8, v/v) was used as mobile phase. The isoenantioselective temperature (T(iso)) was calculated to be 31.4 degrees C. When n-hexane/2-propanol/THF (93/2/5, v/v/v) was used as mobile phase, the T(iso) value decreased to -8.2 degrees C. Entropically driven enantioseparation which had practical application was obtained successfully (separation factor being 1.189 and 1.332 at 25 degrees C and 50 degrees C, respectively). The corresponding thermodynamic parameters for other three binaphthyl compounds were compared with that for BINOL. Some inferences about chiral recognition mechanism were stressed.

  7. Quantification of trace levels of the potential cancer biomarkers formaldehyde, acetaldehyde and propanol in breath by SIFT-MS.

    Science.gov (United States)

    Spaněl, Patrik; Smith, David

    2008-12-01

    The sensitivity of selected ion flow tube mass spectrometry, SIFT-MS, has been increased such that it is now possible to detect metabolites present at a part-per-billion, ppb, level in single breath exhalations. However, to utilize this improved sensitivity, the overlaps (coincidences) of those ions resulting from interfering reactions of impurity precursor ions with some breath metabolites present at higher concentrations with the analytical product ions characteristic of particular metabolites must be accounted for. In this paper, the full reaction schemes are presented for SIFT-MS analyses of three volatile potential cancer biomarkers in exhaled breath, namely formaldehyde, HCHO, acetaldehyde, CH(3)CHO and 2-propanol, CH(3)CH(OH)CH(3), which identify both the characteristic SIFT-MS product ions for these compounds and the interfering ions at the same mass-to-charge, m/z, values. An absolute quantification equation accounting for these interferences is formulated and appropriate entries into the SIFT-MS kinetics library are indicated. It is shown that when using H(3)O(+) to quantify formaldehyde and acetaldehyde the reactions of impurity O(2)(+) ions with methanol and ethanol (always present in breath) must be accounted for and that the quantification of acetaldehyde must avoid the interference of the CO(2) present in exhaled breath. Finally, it is indicated that the analysis of 2-propanol can be achieved using both H(3)O(+) and NO(+) precursor ions.

  8. Fundamental analysis of thermally regenerative fuel cell utilizing solar heat; Taiyonetsu wo riyosuru netsu saiseigata nenryo denchi no kiso tokusei no kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Ando, Y.; Tanaka, T.; Takashima, T.; Doi, T. [Electrotechnical Laboratory, Tsukuba (Japan); Aosawa, T.; Kogoshi, S. [Science University of Tokyo, Tokyo (Japan)

    1997-11-25

    Study was made on a thermally regenerative fuel cell using solar heat. The thermally regenerative fuel cell was devised which is composed of 2-propanol liquid-phase endothermic dehydrogenation at nearly 100degC, and acetone liquid- phase exothermic hydrogenation at nearly 30degC as reverse reaction. This low-temperature dehydrogenation can relatively easily utilize a flat solar heat concentrator. 2-propanol dehydrogenation generates acetone and hydrogen. Generated acetone generates electric power in hydrogenation, generating propanol. This propanol regenerates acetone and hydrogen in dehydrogenation. The activity of Ru and Pt composite catalyst was considerably higher than that of Ru or Pt single catalyst. The activity was also higher in carbon felt or carbon cloth carrier than carbon plate carrier. The open circuit voltage of the fuel cell was estimated to be 110-120mV, nearly consisting with theoretical values. Short circuit current was also estimated to be 9-11mA, suggesting reduction of its internal resistance as an important subject. 4 refs., 5 figs., 2 tabs.

  9. Adsorption and Reaction of C1-C3 Alcohols over CeOx(111) Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    D Mullins; S Senanayake; T Chen

    2011-12-31

    This study reports the interaction of methanol, ethanol, 1-propanol, and 2-propanol with well-ordered CeO{sub 2}(111) thin film surfaces. All of the alcohols adsorb at low temperature by forming alkoxy and hydroxyl species on the surface. On fully oxidized CeO{sub 2}(111), recombination occurs between some of the alkoxys and hydroxyls, resulting in alcohol desorption near 220 K. At the same temperature, some of the surface hydroxyls disproportionate to produce water and the loss of lattice O. The remaining alkoxys react above 550 K. The primary alcohols favor dehydrogenation products (aldehydes). There is a net loss of O from the system, resulting in a reduction of the ceria. The secondary alcohol, 2-propanol, undergoes primarily dehydration, producing propene with no net change in the cerium oxidation state. Reduced CeO{sub x}(111) competes with the gaseous products for available O. Little or no water is produced. The reaction selectivity for the C{sub 2} and C{sub 3} alcohols shifts toward favoring dehydration products. The loss of O from the alcohols leads to oxidation of the reduced ceria. Compared with the oxidized surface, the alkene desorption shifts to lower temperature, whereas the aldehyde desorption shifts to higher temperature. This indicates that, on the reduced surface, it is easier to break the C-O bond but more difficult to break the O-substrate bond.

  10. Effect of morphology and solvent on two-photon absorption of nano zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Kavitha, M.K. [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695547, Kerala (India); Haripadmam, P.C.; Gopinath, Pramod; Krishnan, Bindu [Department of Physics, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695547, Kerala (India); John, Honey, E-mail: honey@iist.ac.in [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695547, Kerala (India)

    2013-05-15

    Highlights: ► ZnO nanospheres and triangular structures synthesis by novel precipitation technique. ► The effect of precursor concentration on the size and shape of nano ZnO. ► Open aperture Z-scan measurements of the ZnO nanoparticle dispersions. ► Nanospheres exhibit higher two photon absorption coefficient than triangular nanostructures. ► Nanospheres dispersed in water exhibit higher two photon absorption coefficient than its dispersion in 2-propanol. - Abstract: In this paper, we report the effect of morphology and solvent on the two-photon absorption of nano zinc oxide. Zinc oxide nanoparticles in two different morphologies like nanospheres and triangular nanostructures are synthesized by novel precipitation technique and their two-photon absorption coefficient is measured using open aperture Z-scan technique. Experimental results show that the zinc oxide nanospheres exhibit higher two-photon absorption coefficient than the zinc oxide triangular nanostructures. The zinc oxide nanospheres dispersed in water exhibit higher two-photon absorption coefficient than that of its dispersion in 2-propanol. The zinc oxide nanospheres dispersed in water shows a decrease in two-photon absorption coefficient with an increase in on-axis irradiance. The result confirms the dependence of shape and solvent on the two-photon absorption of nano zinc oxide.

  11. OPTIMIZING OF TIO2 SEPARATION FROM BANGKA ILMENITE BY LEACHING PROCESS USING HCL

    Directory of Open Access Journals (Sweden)

    Sayekti Wahyuningsih

    2016-09-01

    Full Text Available Separation of titanium dioxide (TiO2 from ilmenite Bangka has been done byleaching processusing HCl. Before the leaching process, ilmenite was roastedat 900oC for pre-oxidation (preliminary - oxidation. Leaching process carried out by variation of HCl concentration and Fe0 reducing agents. While the re-deposition of dissolved Ti4+ ion achieved by hydrolysis - condensation using 2-propanol-H2O solvents. Leaching the pre-oxidazed ilmenite shows the phase change of pseudobrokite (Fe2TiO5 into hematite (Fe2O3 and synthetic rutile (TiO2. Formation of the synthetic rutile was characterized by the loss of intensity of Fe2TiO5 at 26.65º and the increasing intensity of rutile TiO2 at 27.49º.The dissolution rate of both titanium and iron was found to be increased, generally, by increasing acid concentration in case of HCl as well as by increasing ilmenite: Fe0 ratio. Precipitation of the dissolved titania with 2-propanol -H2Oof 8:2(v /v produced anatase TiO2 due to the hydrolysis and condensation of Ti-tetra isopropoxide complexes.

  12. Disposition and metabolism of cumene in F344 rats and B6C3F1 mice.

    Science.gov (United States)

    Chen, Ling-Jen; Wegerski, Christopher J; Kramer, Daniel J; Thomas, Leslie A; McDonald, Jacob D; Dix, Kelly J; Sanders, J Michael

    2011-03-01

    Cumene is a high-production volume chemical that has been shown to be a central nervous system depressant and has been implicated as a long-term exposure carcinogen in experimental animals. The absorption, distribution, metabolism, and excretion of [(14)C]cumene (isopropylbenzene) was studied in male rats and mice of both sexes after oral or intravenous administration. In both species and sexes, urine accounted for the majority of the excretion (typically ≥ 70%) by oral and intravenous administration. Enterohepatic circulation of cumene and/or its metabolites was indicated because 37% of the total dose was excreted in bile in bile duct-cannulated rats with little excreted in normal rats. The highest tissue (14)C levels in rats were observed in adipose tissue, liver, and kidney with no accumulation observed after repeat dosing up to 7 days. In contrast, mice contained the highest concentrations of (14)C at 24 h after dosing in the liver, kidney, and lung, with repeat dosing accumulation of (14)C observed in these tissues as well as in the blood, brain, heart, muscle, and spleen. The metabolites in the expired air, urine, bile, and microsomes were characterized with 16 metabolites identified. The volatile organics in the expired air comprised mainly cumene and up to 4% α-methylstyrene. The major urinary and biliary metabolite was 2-phenyl-2-propanol glucuronide, which corresponded with the main microsomal metabolite being 2-phenyl-2-propanol.

  13. Dependence of enthalpies of dissolution of {beta}-alanyl-{beta}-alanine on the composition of (water + alcohol) mixtures at 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, Valeriy I., E-mail: vis@isc-ras.ru [Laboratory of Thermodynamics of Non-electrolytes Solutions and Biologically Active Substances, Institute of Solution Chemistry, Russian Academy of Sciences, 1 Akademicheskaya Street, 153045 Ivanovo (Russian Federation); Badelin, Valentin G. [Laboratory of Thermodynamics of Non-electrolytes Solutions and Biologically Active Substances, Institute of Solution Chemistry, Russian Academy of Sciences, 1 Akademicheskaya Street, 153045 Ivanovo (Russian Federation)

    2011-09-20

    Highlights: {center_dot} Enthalpies of dissolution of {beta}-alanyl-{beta}-alanine are measured in aqueous methanol, ethanol, 1-propanol and 2-propanol by calorimetry. {center_dot} Standard values of dissolution and transfer enthalpies of {beta}-alanyl-{beta}-alanine and enthalpy coefficients of pair-wise interactions are calculated. {center_dot} Dependences of the thermodynamic characteristics of dissolution of {beta}-alanyl-{beta}-alanine on the composition of (water + alcohol) mixtures are determined. - Abstract: The dissolution enthalpies of {beta}-alanyl-{beta}-alanine in aqueous methanol, ethanol, 1-propanol and 2-propanol solutions with an alcohol content up to 0.4 mole fractions have been measured calorimetrically at T = 298.15 K. The standard enthalpies of dissolution, {Delta}{sub sol}H{sup o} and transfer, {Delta}{sub tr}H{sup o}, of {beta}-alanyl-{beta}-alanine from water into mixed solvents and the enthalpy coefficients of pair-wise interactions, h{sub xy}, of {beta}-alanyl-{beta}-alanine with alcohol solvent molecules have been calculated. The results are discussed in terms of solute-solute and solute-solvent interactions.

  14. Effect of mixing, concentration and temperature on the formation of mesostructured solutions and their role in the nucleation of DL-valine crystals.

    Science.gov (United States)

    Jawor-Baczynska, Anna; Moore, Barry D; Sefcik, Jan

    2015-01-01

    We report investigations on the formation of mesostructured solutions in DL-valine-water-2-propanol mixtures, and the crystallization of DL-valine from these solutions. Mesostructured liquid phases, similar to those previously observed in aqueous solutions of glycine and DL-alanine, were observed using Dynamic Light Scattering and Brownian microscopy, in both undersaturated and supersaturated solutions below a certain transition temperature. Careful experimentation was used to demonstrate that the optically clear mesostructured liquid phase, comprising colloidal mesoscale clusters dispersed within bulk solution, is thermodynamically stable and present in equilibrium with the solid phase at saturation conditions. Solutions prepared by slow cooling contained mesoscale clusters with a narrow size distribution and a mean hydrodynamic diameter of around 200 nm. Solutions of identical composition prepared by rapid isothermal mixing of valine aqueous solutions with 2-propanol contained mesoscale clusters which were significantly larger than those observed in slowly cooled solutions. The presence of larger mesoscale clusters was found to correspond to faster nucleation. Observed induction times were strongly dependent on the rapid initial mixing step, although solutions were left undisturbed afterwards and the induction times observed were up to two orders of magnitude longer than the initial mixing period. We propose that mesoscale clusters above a certain critical size are likely to be the location of productive nucleation events.

  15. Influence of the composition of aqueous-alcohol solvents on the thermodynamic characteristics of L-phenylalanine dissolution at 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Badelin, Valentin G. [Laboratory of Thermodynamics of Solutions of Non-electrolytes and Biologically Active Substances, Institute of Solution Chemistry, Russian Academy of Sciences, 1 Akademicheskaya Street, 153045, Ivanovo (Russian Federation); Smirnov, Valeriy I., E-mail: vis@isc-ras.ru [Laboratory of Thermodynamics of Solutions of Non-electrolytes and Biologically Active Substances, Institute of Solution Chemistry, Russian Academy of Sciences, 1 Akademicheskaya Street, 153045, Ivanovo (Russian Federation)

    2011-11-10

    Highlights: Black-Right-Pointing-Pointer Enthalpies of L-phenylalanine dissolution have been measured in aqueous methanol, ethanol, 1-propanol and 2-propanol. Black-Right-Pointing-Pointer The measured data were reported as functions of composition of water + alcohol mixtures. Black-Right-Pointing-Pointer Enthalpy coefficients of pair-wise interactions have been analyzed in terms of McMillan-Mayer theory. Black-Right-Pointing-Pointer A comparative analysis of the characteristics of dissolution of L-phenylalanine and some other L-amino acids in the similar systems has been made. - Abstract: The enthalpies of L-phenylalanine dissolution in aqueous methanol, ethanol, 1-propanol and 2-propanol have been determined by calorimetry at 298.15 K and alcohol mole fractions up to x{sub 2} {approx}0.4. The standard enthalpies of solution {Delta}{sub sol}H Degree-Sign and transfer {Delta}{sub tr}H Degree-Sign from water to the mixed solvent as well as the enthalpy coefficients of L-phenylalanine-alcohol pair-wise interactions were calculated. The interrelation of the enthalpies of dissolution and transfer for L-phenylalanine with structural features of alcohols has been determined. A comparative analysis of the thermodynamic characteristics of dissolution of L-phenylalanine and some other amino acids (glycine, L-alanine, L-threonine and L-valine) in the mixtures studied has been made.

  16. Synthesis of sup 18 F-labeled fluconazole and positron emission tomography studies in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Livni, E. (Massachusetts General Hospital, Boston, MA (United States). Dept. of Radiology); Fischman, A.J. (Massachusetts General Hospital, Boston, MA (United States). Radiology Dept. Havard Medical School, Boston, MA (United States). Dept. of Radiology Havard Medical School, Boston, MA (United States). Dept. of Medicine)

    1992-02-01

    (4-{sup 18}F) 2-(2,4-difluorophenyl)-1,3-bis(1H-1,2,4-triazol-1-yl)-2-propanol ((4-{sup 18}F) fluconazole) was synthesized from its amino precursor. Fieldel-Crafts acylation of 3-fluoroacetanilide with chloroacetyl chloride produced 2'-fluoro-4'-aceteamido-2-(1H-1,2,4-triazole-1-yl) acetophenone in 12% yield. Sequential reaction with (1) dimethylsulphoxonium methylide and (2) 1,2,4-triazole followed by in situ hydrolysis resulted in 2-(2-fluoro-4-aminophenyl)-1,3-bis(1H-2,2,4-triazol-1-yl)-2-propanol in 19% yield. A modified Schiemann reaction on this product resulted in (4-{sup 18}F)fluconazole with a radiochemical yield of 1.0-2.0% (EOS) within 2h. (4-{sup 18}F)Fluconazole was used to measure the pharmacokinetics of fluconazole in rats by measurement of radioactivity in excised tissues and in rabbits by PET. In both species, there was rapid equilibration of (4-{sup 18}F)fluoconazole to a relatively uniform distribution of radioactivity in most organs. (Author).

  17. Synthesis of short-chain diols and unsaturated alcohols from secondary alcohol substrates by the Rieske nonheme mononuclear iron oxygenase MdpJ.

    Science.gov (United States)

    Schäfer, Franziska; Schuster, Judith; Würz, Birgit; Härtig, Claus; Harms, Hauke; Müller, Roland H; Rohwerder, Thore

    2012-09-01

    The Rieske nonheme mononuclear iron oxygenase MdpJ of the fuel oxygenate-degrading bacterial strain Aquincola tertiaricarbonis L108 has been described to attack short-chain tertiary alcohols via hydroxylation and desaturation reactions. Here, we demonstrate that also short-chain secondary alcohols can be transformed by MdpJ. Wild-type cells of strain L108 converted 2-propanol and 2-butanol to 1,2-propanediol and 3-buten-2-ol, respectively, whereas an mdpJ knockout mutant did not show such activity. In addition, wild-type cells converted 3-methyl-2-butanol and 3-pentanol to the corresponding desaturation products 3-methyl-3-buten-2-ol and 1-penten-3-ol, respectively. The enzymatic hydroxylation of 2-propanol resulted in an enantiomeric excess of about 70% for the (R)-enantiomer, indicating that this reaction was favored. Likewise, desaturation of (R)-2-butanol to 3-buten-2-ol was about 2.3-fold faster than conversion of the (S)-enantiomer. The biotechnological potential of MdpJ for the synthesis of enantiopure short-chain alcohols and diols as building block chemicals is discussed.

  18. Purification and properties of a secondary alcohol dehydrogenase from the parasitic protozoan Tritrichomonas foetus.

    Science.gov (United States)

    Kleiner, D E; Johnston, M

    1985-07-05

    A novel secondary alcohol dehydrogenase has been isolated from Tritrichomonas foetus, the protozoan parasite which is responsible for bovine trichomonal abortion. The enzyme has been obtained in apparently homogeneous form after a 120-fold purification from cell homogenates, thus indicating that this activity constitutes an unusually high 1% of the total cytosolic protein. The native Mr = 115,000, determined by polyacrylamide gel electrophoresis. Mobility on sodium dodecyl sulfate gels suggests that the enzyme is composed of 6-8 subunits, identical as to molecular size (Mr = 17,000). The enzyme catalyzes the reversible oxidation of 2-propanol to acetone, using NADP+ (and not NAD+) as the redox-active co-substrate. Other small secondary alcohols, such as 2-butanol, 2- and 3-pentanol, cyclobutanol, and cyclopentanol are substrates, as are the corresponding ketones of these alcohols. Primary alcohols, such as ethanol and 1-propanol, are oxidized at rates less than 5% of that observed for 2-propanol. Product inhibition studies demonstrate an ordered kinetic mechanism, wherein the co-substrate (NADP+/NADPH) binds to the enzyme prior to binding of the substrate (alcohol/ketone).

  19. Effect of reduction enhancer on a radiolytic synthesis of carbon-supported Pt–Cu nanoparticles and their structural and electrochemical properties

    Energy Technology Data Exchange (ETDEWEB)

    Kugai, Junichiro, E-mail: jkugai@kobe-kosen.ac.jp [Kobe City College of Technology, Department of Applied Chemistry (Japan); Kubota, Chihiro; Okazaki, Tomohisa; Seino, Satoshi; Nakagawa, Takashi [Osaka University, Graduate School of Engineering (Japan); Nitani, Hiroaki [High Energy Accelerator Research Organization, Institute of Materials Structure Science (IMSS) (Japan); Yamamoto, Takao A. [Osaka University, Graduate School of Engineering (Japan)

    2015-06-15

    In order to clarify the effect of reduction enhancer on the nanoparticle formation process and their structural and catalytic properties, carbon-supported Pt–Cu nanoparticles were synthesized by electron beam irradiation on an aqueous precursor solution in the presence/absence of reduction enhancer. In the absence of reduction enhancer, tetravalent platinum oxide particles of approximately 1 nm in diameter were formed on carbon support with copper barely precipitated, while in the presence of 2-propanol or ethylene glycol or glucose both platinum and copper precipitated as few-nanometer-sized alloy particles together with copper oxides. It was suggested that the metal nuclei produced upon electron beam irradiation do not have enough lifetime without reduction enhancer due to fast oxidation of the nuclei by oxidizing radicals, while the reduction enhancer scavenges these oxidizing radicals preventing oxidation of metallic clusters and prolonging their lifetime. Ethylene glycol gave smaller and better alloyed particles with less copper oxides compared to 2-propanol since the carbonyl compounds derived from oxidation of ethylene glycol protect metallic clusters from oxidation further prolonging their lifetime. In the electrochemical measurements, the methanol oxidation activities of Pt–Cu/C catalysts were well explained by their structural characteristics.

  20. Research and development for solar thermal energy system. Research on advanced solar component; Taiyonetsu energy system no kenkyu kaihatsu. Kiki no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T.; Doi, T.; Takashima, T.; Ando, Y.; Masuda, T.; Fujii, T. [Electrotechnical Laboratory, Tsukuba (Japan)

    1994-12-01

    Described herein are the results of the FY1994 research program for research on advanced solar components as part of research and development of solar thermal energy. The catalyst for liquid-film reactions is prepared, and the flask tests are conducted as the preliminary experiments for development of the reactor in which 2-propanol is fallen in liquid film over the catalyst dispersed to accelerate its decomposition. It is decomposable when fallen in liquid film even in the presence of 35% of acetone. The catalyst of ruthenium carried by activated coal is used to produce 2-propanol under an exothermic condition from acetone and hydrogen. Diisopropyl ether and 4-methyl-2-pentanone are produced as by-products, when the reactor tube is kept at 140 to 200{degree}C at the external wall, diminishing as temperature is increased. There is a temperature differential of 20 to 30{degree}C in the reactor tube between the center axis and external wall. 3 figs.

  1. In vitro study on the disinfectability of two split-septum needle-free connection devices using different disinfection procedures

    Directory of Open Access Journals (Sweden)

    Engelhart, Steffen

    2015-12-01

    Full Text Available This in vitro study investigated the external disinfection of two needle-free connection devices (NFC using Octeniderm (spraying and wiping technique vs. Descoderm pads (wiping technique. The split-septum membrane of the NFC was contaminated with >10 CFU . The efficacy of the disinfection at 30 sec. exposure time was controlled by taking a swab sample and by flushing the NFC with sterile 0.9% sodium chloride solution. Disinfection with octenidine dihydrochloride 0.1 g, 1-Propanol 30.0 g, and 2-Propanol 45.0 g in solution was highly effective (CFU reduction ≥4 log against both microorganisms, whereas the use of 63.1 g 2-Propanol in 100 ml solution led to residual contamination with . Our investigation underlines that (i in clinical practice disinfection of NFCs before use is mandatory, and that (ii details of disinfection technique are of utmost importance regarding their efficacy. Our investigation revealed no significant differences between both split-septum NFC types. Clinical studies are needed to confirm a possible superiority of disinfectants with long-lasting residual antimicrobial activity.

  2. Liquid-Phase Catalytic Transfer Hydrogenation of Furfural over Homogeneous Lewis Acid-Ru/C Catalysts.

    Science.gov (United States)

    Panagiotopoulou, Paraskevi; Martin, Nickolas; Vlachos, Dionisios G

    2015-06-22

    The catalytic performance of homogeneous Lewis acid catalysts and their interaction with Ru/C catalyst are studied in the catalytic transfer hydrogenation of furfural by using 2-propanol as a solvent and hydrogen donor. We find that Lewis acid catalysts hydrogenate the furfural to furfuryl alcohol, which is then etherified with 2-propanol. The catalytic activity is correlated with an empirical scale of Lewis acid strength and exhibits a volcano behavior. Lanthanides are the most active, with DyCl3 giving complete furfural conversion and a 97 % yield of furfuryl alcohol at 180 °C after 3 h. The combination of Lewis acid and Ru/C catalysts results in synergy for the stronger Lewis acid catalysts, with a significant increase in the furfural conversion and methyl furan yield. Optimum results are obtained by using Ru/C combined with VCl3 , AlCl3 , SnCl4 , YbCl3 , and RuCl3 . Our results indicate that the combination of Lewis acid/metal catalysts is a general strategy for performing tandem reactions in the upgrade of furans.

  3. Hydrophobic and hydrophilic interactions in aqueous mixtures of alcohols at a hydrophobic surface.

    Science.gov (United States)

    Ballal, Deepti; Chapman, Walter G

    2013-09-21

    Aqueous solutions of alcohols are interesting because of their anomalous behavior that is believed to be due to the molecular structuring of water and alcohol around each other in solution. The interfacial structuring and properties are significant for application in alcohol purification processes and biomolecular structure. Here we study aqueous mixtures of short alcohols (methanol, ethanol, 1-propanol, and 2-propanol) at a hydrophobic surface using interfacial statistical associating fluid theory which is a perturbation density functional theory. The addition of a small amount of alcohol decreases the interfacial tension of water drastically. This trend in interfacial tension can be explained by the structure of water and alcohol next to the surface. The hydrophobic group of an added alcohol preferentially goes to the surface preserving the structure of water in the bulk. For a given bulk alcohol concentration, water mixed with the different alcohols has different interfacial tensions with propanol having a lower interfacial tension than methanol and ethanol. 2-propanol is not as effective in decreasing the interfacial tension as 1-propanol because it partitions poorly to the surface due to its larger excluded volume. But for a given surface alcohol mole fraction, all the alcohol mixtures give similar values for interfacial tension. For separation of alcohol from water, methods that take advantage of the high surface mole fraction of alcohol have advantages compared to separation using the vapor in equilibrium with a water-alcohol liquid.

  4. Organoclay hybrid materials as precursors of porous ZnO/silica-clay heterostructures for photocatalytic applications

    Directory of Open Access Journals (Sweden)

    Marwa Akkari

    2016-12-01

    Full Text Available In this study, ZnO/SiO2-clay heterostructures were successfully synthesized by a facile two-step process applied to two types of clays: montmorillonite layered silicate and sepiolite microfibrous clay mineral. In the first step, intermediate silica–organoclay hybrid heterostructures were prepared following a colloidal route based on the controlled hydrolysis of tetramethoxysilane in the presence of the starting organoclay. Later on, pre-formed ZnO nanoparticles (NP dispersed in 2-propanol were incorporated under ultrasound irradiation to the silica–organoclay hybrid heterostructures dispersed in 2-propanol, and finally, the resulting solids were calcinated to eliminate the organic matter and to produce ZnO nanoparticles (NP homogeneously assembled to the clay–SiO2 framework. In the case of montmorillonite the resulting materials were identified as delaminated clays of ZnO/SiO2-clay composition, whereas for sepiolite, the resulting heterostructure is constituted by the assembling of ZnO NP to the sepiolite–silica substrate only affecting the external surface of the clay. The structural and morphological features of the prepared heterostructures were characterized by diverse physico-chemical techniques (such as XRD, FTIR, TEM, FE-SEM. The efficiency of these new porous ZnO/SiO2-clay heterostructures as potential photocatalysts in the degradation of organic dyes and the removal of pharmaceutical drugs in water solution was tested using methylene blue and ibuprofen compounds, respectively, as model of pollutants.

  5. Effect of biomass pre-treatment and solvent extraction on beta-carotene and lycopene recovery from Blakeslea trispora cells.

    Science.gov (United States)

    Papaioannou, E; Roukas, T; Liakopoulou-Kyriakides, M

    2008-01-01

    The production of carotenoids from Blakeslea trispora cells in a synthetic medium has been reported, with the main products being beta-carotene, lycopene, and gamma-carotene. The effect of biomass pretreatment and solvent extraction on their selective recovery is reported here. Eight solvents of class II and III of the International Conference of Harmonization: ethanol, methanol, acetone, 2-propanol, pentane, hexane, ethyl acetate, and ethyl ether, and HPLC analysis were used for the evaluation of their selectivities towards the three main carotenoids with regard to different biomass pre-treatment. The average C(max) values (maximum concentration of caronoids in a specific solvent) were estimated to 16 mg/L with the five out of eight solvents investigated, whereas methanol, pentane, and hexane gave lower values of 10, 11, and 9 mg/L, respectively. The highest carotenoid yield was obtained in the case of wet biomass, where 44-56% is recovered with one solvent and three extractions and the rest is recovered only after subsequent treatment with acetone; thus, four extractions of 2.5 h are needed. Two extractions of 54 min are enough to recover carotenoids from dehydrated biomass, with the disadvantage of a high degree of degradation. Our results showed that, for maximum carotenoid recovery, ethyl ether, 2-propanol, and ethanol could be successfully used with biomass without prior treatment, whereas fractions enriched in beta-carotene or lycopene can be obtained by extraction with the proper solvent, thus avoiding degradation due to time-consuming processes.

  6. Efficacy of hand disinfectants against vancomycin-resistant enterococci in vitro.

    Science.gov (United States)

    Kampf, G; Höfer, M; Wendt, C

    1999-06-01

    Vancomycin-resistant enterococci (VRE) may be spread within a hospital via the contaminated hands of the healthcare worker. Effective hand disinfectants are necessary to break chains of transmission. We determined the bactericidal activity of 1-propanol, chlorhexidine digluconate (0.5 and 4%). Sterillium (45% 2-propanol, 30% 1-propanol and 0.2% mecetronium etilsulphate), Skinsept F (70% 2-propanol, 0.5% chlorhexidine digluconate and 0.45% hydrogen peroxide) and Hibisol (70% 2-propanol and 0.5% chlorhexidine gluconate) against 11 clonally distinct enterococcal isolates in a quantitative suspension test. Four isolates were vancomycin susceptible, four were vanA and the remainder vanB positive. Eight isolates were identified as Enterococcus faecium, two as Enterococcus faecalis and one as Enterococcus gallinarum. The investigator was blinded to the species and the genotype. Four parallel experiments were carried out for each isolate, each preparation, each dilution and each reaction time. 1-Propanol (60%), Sterillium, Skinsept F and Hibisol were all highly bactericidal after 15 and 30 s against VRE and vancomycin-susceptible enterococci (VSE) with reduction factors (RF) > 6.4, even in dilution of 50% (v/v). No significant difference was observed between vanA isolates, vanB isolates and VSE. Chlorhexidine digluconate (0.5% and 4%) was found to be less bactericidal after 30, 60 and 300 sec (RF < or = 2.5). The vanB genotype isolates were found to be significantly more susceptible to chlorhexidine (0.5%) than the vanA isolates (60 sec; one-way ANOVA model; P = 0.05). After 300 sec the vanB genotype isolates were found to be significantly more susceptible to chlorhexidine (0.5%) than the other two genotype isolates (P = 0.016). The vanA isolates were found to be significantly more susceptible to chlorhexidine (4%) than the vanB isolates (300 s; P = 0.024). E. faecium was found to be less susceptible to chlorhexidine than E. faecalis at all concentrations and reaction

  7. Contribution of Liver Alcohol Dehydrogenase to Metabolism of Alcohols in Rats

    Science.gov (United States)

    Plapp, Bryce V.; Leidal, Kevin G.; Murch, Bruce P.; Green, David W.

    2015-01-01

    The kinetics of oxidation of various alcohols by purified rat liver alcohol dehydrogenase (ADH) were compared with the kinetics of elimination of the alcohols in rats in order to investigate the roles of ADH and other factors that contribute to the rates of metabolism of alcohols. Primary alcohols (ethanol, 1-propanol, 1-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol) and diols (1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol) were eliminated in rats with zero-order kinetics at doses of 5–20 mmole/kg. Ethanol was eliminated most rapidly, at 7.9 mmole/kg•h. Secondary alcohols (2-propanol-d7, 2-propanol, 2-butanol, 3-pentanol, cyclopentanol, cyclohexanol) were eliminated with first order kinetics at doses of 5–10 mmole/kg, and the corresponding ketones were formed and slowly eliminated with zero or first order kinetics. The rates of elimination of various alcohols were inhibited on average 73% (55% for 2-propanol to 90% for ethanol) by 1 mmole/kg of 4-methylpyrazole, a good inhibitor of ADH, indicating a major role for ADH in the metabolism of the alcohols. The Michaelis kinetic constants from in vitro studies (pH 7.3, 37 °C) with isolated rat liver enzyme were used to calculate the expected relative rates of metabolism in rats. The rates of elimination generally increased with increased activity of ADH, but a maximum rate of 6 ± 1 mmole/kg•h was observed for the best substrates, suggesting that ADH activity is not solely rate-limiting. Because secondary alcohols only require one NAD+ for the conversion to ketones whereas primary alcohols require two equivalents of NAD+ for oxidation to the carboxylic acids, it appears that the rate of oxidation of NADH to NAD+ is not a major limiting factor for metabolism of these alcohols, but the rate-limiting factors are yet to be identified. PMID:25641189

  8. Thermodynamic properties of binary mixtures containing dimethyl carbonate+2-alkanol: Experimental data, correlation and prediction by ERAS model and cubic EOS

    Energy Technology Data Exchange (ETDEWEB)

    Almasi, Mohammad, E-mail: m.almasi@khouzestan.srbiau.ac.ir [Department of Chemistry, Science and Research Branch, Islamic Azad University, Khouzestan (Iran, Islamic Republic of)

    2013-03-01

    Densities and viscosities for binary mixtures of dimethyl carbonate with 2-propanol up to 2-heptanol were measured at various temperatures and ambient pressure. From experimental data, excess molar volumes, V{sub m}{sup E}. were calculated and correlated by the Redlich–Kister equation to obtain the binary coefficients and the standard deviations. Excess molar volumes, V{sub m}{sup E}, are positive for all studied mixtures over the entire range of the mole fraction. The ERAS-model has been applied for describing the binary excess molar volumes and also Peng–Robinson–Stryjek–Vera (PRSV) equation of state (EOS) has been used to predict the binary excess molar volumes and viscosities. Also several semi-empirical models were used to correlate the viscosity of binary mixtures.

  9. Derived thermodynamic properties of alcohol + cyclohexylamine mixtures

    Directory of Open Access Journals (Sweden)

    IVONA R. RADOVIĆ

    2010-02-01

    Full Text Available Thermal expansion coefficients, α, excess thermal expansion coefficients, αE, isothermal coefficients of pressure excess molar enthalpy, (∂HE/∂pT,x, partial molar volumes, , partial molar volumes at infinite dilution, , partial excess molar volumes, , and partial excess molar volumes at infinite dilution, , were calculated using experimental densities and excess molar volumes, , data. All calculations are performed for the binary systems of cyclohexylamine with 1-propanol or 1-butanol or 2-butanol or 2-methyl-2-propanol. The Redlich–Kister polynomial and the reduced excess molar volume approach were used in the evaluation of these properties. In addition, the aim of this investigation was to provide a set of various volumetric data in order to asses the influence of temperature, chain length and position of hydroxyl group in the alcohol molecule on the molecular interactions in the examined binary mixtures.

  10. Nitrogen-doped titanium dioxide photocatalysts for visible response prepared by using organic compounds

    Directory of Open Access Journals (Sweden)

    Yoshio Nosaka, Masami Matsushita, Junichi Nishino and Atsuko Y. Nosaka

    2005-01-01

    Full Text Available In order to utilize visible light in photocatalytic reactions, nitrogen atoms were doped in commercially available photocatalytic TiO2 powders by using an organic compound such as urea and guanidine. Analysis by X-ray photoelectron spectroscopy (XPS indicated that N atoms were incorporated into two different sites of the bulk phase of TiO2. A significant shift of the absorption edge to a lower energy and a higher absorption in the visible light region were observed. These N-doped TiO2 powders exhibited photocatalytic activity for the decomposition of 2-propanol in aqueous solution under visible light irradiation. The photocatalytic activity increased with the decrease of doped N atoms in O site, while decreased with decrease of the other sites. Degradation of photocatalytic activity based on the release of nitrogen atoms was observed for the reaction in the aqueous suspension system.

  11. Dynamics of water and solute transport in polymeric reverse osmosis membranes via molecular dynamics simulations

    CERN Document Server

    Shen, Meng; Lueptow, Richard M

    2016-01-01

    The Angstrom-scale transport characteristics of water and six different solutes, methanol, ethanol, 2-propanol, urea, Na+, and Cl-, were studied for a polyamide reverse osmosis (RO) membrane, FT-30, using non-equilibrium molecular dynamics (NEMD) simulations. Results indicate that water transport increases with an increasing fraction of connected percolated free volume, or water-accessible open space, in the membrane polymer structure. This free volume is enhanced by the dynamic structure of the membrane at the molecular level as it swells when hydrated and vibrates due to molecular collisions allowing a continuous path connecting the opposite membrane surfaces. The tortuous paths available for transport of solutes result in Brownian motion of solute molecules and hopping from pore to pore as they pass through the polymer network structure of the membrane. The transport of alcohol solutes decreases for solutes with larger Van der Waals volume, which corresponds to less available percolated free volume, or sol...

  12. UV-polymerized butyl methacrylate monoliths with embedded carboxylic single-walled carbon nanotubes for CEC applications.

    Science.gov (United States)

    Navarro-Pascual-Ahuir, María; Lucena, Rafael; Cárdenas, Soledad; Ramis-Ramos, Guillermo; Valcárcel, Miguel; Herrero-Martínez, José Manuel

    2014-10-01

    The preparation of polymeric monoliths with embedded carboxy-modified single-walled carbon nanotubes (c-SWNTs) and their use for capillary electrochromatography (CEC) is described. Carbon nanotube composites were obtained by preparing a polymerization mixture in the presence of increasing c-SWNT concentrations, followed by UV initiation. The novel stationary phases were studied by optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Using short UV-polymerization times, the optimized porogenic solvent (a binary mixture of 1,4-butanediol and 2-propanol) gave rise to polymeric beds with homogenously dispersed embedded c-SWNTs. The CEC features of these monoliths were evaluated using polycyclic aromatic hydrocarbons (PAHs), non-steroidal anti-inflammatory drugs (NSAIDs) and chiral compounds. The monolith prepared in the presence of c-SWNTs showed enhanced resolution of the text mixtures, including a remarkable capability to separate enantiomers.

  13. PREPARATION OF POLYETHERSULFONE ULTRAFILTRATION MEMBRANES FOR MILK CONCENTRATION AND EFFECTS OF ADDITIVES ON THEIR MORPHOLOGY AND PERFORMANCE

    Institute of Scientific and Technical Information of China (English)

    S.S. Madaeni; A. Rahimpour

    2005-01-01

    Polyethersulfone membranes were prepared from quaternary systems containing N,N-dimethylacetamide (DMAc) as solvent, polyvinylpyrrolidone (PVP) as constant additive and acetic acid, acetone and water as variable additives. Phase inversion via immersion precipitation was employed for manufacturing of membranes. The prepared films were immersed in the mixture of pure water and 2-propanol (30/70 vol%) as the non-solvent. Acetic acid caused an increment in the flux at high polymer concentration (16wt%) and a decline in the flux at low polymer concentrations (10 wt% and 13 wt%). Acetone and water as the solvent in the casting solution declined the flux at any polymer concentration tested. The morphology and performance of the prepared membranes were investigated by scanning electron microscopy and separation experiments using milk as the feed.

  14. 利用二元体系的C-H红外光谱推算汽液平衡数据%Prediction of Vapor-Liquid Equilibrium Data from C-H Band Shift of IR Spectra in Some Binary Systems

    Institute of Scientific and Technical Information of China (English)

    朱霄; 姚加; 李浩然; 韩世钧

    2007-01-01

    Prediction of vapor-liquid equilibrium (VLE) is extremely necessary to separate liquid mixture in chemical production, especially when the required experimental data are difficult to measure, or the measurement is not economical. The infinite dilution activities can be used to predict VLE. However, it needs both thc ends of the activities that are difficult to obtain for many systems. In the present study, a new model is proposed for correlating the frequency shift of C-H stretching band of IR spectra over the whole concentration. Investigated mixtures include water/2-propanol, water/N, N-dimethylformamide (DMF), water/methanol, water/ethanol, water/1, 4-dioxane,and water/dimethylsulfoxidc (DMSO) systems. Simultaneous correlations of C-H frequency shift and VLE data arc made. Furthermore, the VLE data were predicted with satisfactory results by the parameters obtained from IR spectra coupled with one of the infinite dilution activity coefficients.

  15. Effect of solvents on propylene epoxidation over TS-1 catalyst

    Institute of Scientific and Technical Information of China (English)

    Yulong WU; Qingshan LIU; Xueli SU; Zhentao MI

    2008-01-01

    Solvents have an important effect on the epoxidation of propylene catalyzed by TS-1. The experimental results show that, in different solvents, the catalytic activity of epoxidation is in the following order: methanol > 2-propanol > 2-butanol > acetoni-trile > acetone > tetrahydrofuran. Based on the reaction mechanism, the effects of solvents on the epoxidation were studied from eight aspects, which included the electronic effect, the steric effect, the polarity of solvent, the effect of solvent on sorption and diffusion of reactant, the oxidation of alcohol, the etherification of PO, the deactivation of TS-1 and the solubility of propylene in the solvents. The electronic effect, steric effect and the polarity of solvent were considered to be the main aspects. This work may provide theoretical guidance for choosing solvents for these kinds of reactions and also may serve as basis for further industrialization.

  16. Hydrogen Peroxide in Fluorinated Alcohols: A Potent and Selective Oxidative System

    Institute of Scientific and Technical Information of China (English)

    Jernej Iskra

    2005-01-01

    @@ 1Introduction Fluorinated alcohols such as 1,1,1,3,3,3-hexafluoro-2-propanol and 2,2,2-trifluoroetanol have particular properties compared to non-fluorinated ones and could provoke changes in the course of reactions in these solvents. Their specific properties are connected mainly to the strong hydrogen bond donor ability and solvation of nuclephiles on one side, and weak hydrogen bond acceptor strength and weak solvation of electrophiles on the other. This dichotomy makes them very attractive solvents for various chemical reactions including cleavage of O - O and C - O bonds and cycloadditions[1]. At first they were used for solvolysis studies and stabilization of kationic intermediates and kation radicals, then their use was extended to various chemical synthesis and to biochemistry, where their effect on the formation of hydrogen bonds was used to alter the conformations of peptides and proteins[2].

  17. MEZCLAS BINARIAS DE LÍQUIDO IÓNICO CON SOLVENTE MOLECULAR: PREDICCIÓN DEL VOLUMEN DE EXCESO MOLAR DESDE ÍNDICES DE REFRACCIÓN

    Directory of Open Access Journals (Sweden)

    Marlon Doney Martínez Reina

    2011-01-01

    Full Text Available El volumen de exceso molar de 30 mezclas binarias que contienen líquidos iónicos de imidazolio con diferentes solventes moleculares: (metanol, etanol, 1-propanol, 2-propanol, acetona, 2- butanona, 2-pentanona, acetato de metilo, acetato de etilo, acetato de butilo, carbonato de dimetilo, carbonato de dietilo, nitrometano, 1,3-dicloropropano y etilenglicol,se predice desde datos de índice de refracción, usando tres tipos de métodos acoplados con diferentes reglas de mezcla para el cálculo del índice de refracción: Lorentz-Lorenz, Dale-Gladstone, Eykman, Arago- Biot, Newton y Oster. En estos sistemas, las interacciones moleculares y las fuerzas intermoleculares provocan, durante la mezcla, desviaciones positivas o negativas del comportamiento ideal. Los resultados obtenidos se analizan en términos de la naturaleza del líquido iónico y solvente molecular.

  18. Porous silicon optical template for determination of chromatic dispersion of transparent liquid mixture

    Science.gov (United States)

    Cafe, Arven I.; Lopez, Joybelle; Lopez, Lorenzo; Faustino, Maria Angela; Mabilangan, Arvin; Salvador, Arnel; Somintac, Armando

    2017-03-01

    Porous silicon was fabricated through electrochemical etching and is used as an optical template for liquid sensing application. Using reflectance spectroscopy, change in optical properties such as refractive index and reflectivity upon liquid introduction were obtained. Chromatic dispersion of porous silicon upon detection of transparent liquids such as absolute ethanol, methanol, 2-propanol and distilled water were determined for spectral range 450nm to 1100nm. Mixture of the organic transparent liquid and water was also tested. In this study, porosity and liquid's concentration were varied to establish the sensitivity of detection. Expected ideal values were also simulated for comparison and correction factor computation. Results provide calibration basis for water quality assessment, environmental monitoring, and diagnostic application.

  19. Selecting water-alcohol mixed solvent for synthesis of polydopamine nano-spheres using solubility parameter

    Science.gov (United States)

    Jiang, Xiaoli; Wang, Yinling; Li, Maoguo

    2014-08-01

    The solvent plays an important role in a given chemical reaction. Since most reaction in nature occur in the mixed-solvent systems, a comprehensive principle for solvent optimization was required. By calculating the Hansen solubility parameters (HSP) distance Ra, we designed a model experiment to explore the influence of mixed solvents on the chemical synthesis. The synthesis of polydopamine (PDA) in the water-alcohol system was chosen as model. As predicted, the well-dispersed PDA spheres were obtained in selected solvents with smaller Ra values: methanol/water, ethanol/water and 2-propanol/water. In addition, the mixed solvent with smaller Ra values gave a higher conversion of dopamine. The strategy for mixed solvent selection is might be useful to choose optimal reaction media for efficient chemical synthesis.

  20. Determining an Efficient Solvent Extraction Parameters for Re-Refining of Waste Lubricating Oils

    Directory of Open Access Journals (Sweden)

    Hassan Ali Durrani

    2012-04-01

    Full Text Available Re-refining of vehicle waste lubricating oil by solvent extraction is one of the efficient and cheapest methods. Three extracting solvents MEK (Methyl-Ethyl-Ketone, 1-butanol, 2-propanol were determined experimentally for their performance based on the parameters i.e. solvent type, solvent oil ratio and extraction temperature. From the experimental results it was observed the MEK performance was highest based on the lowest oil percent losses and highest sludge removal. Further, when temperature of extraction increased the oil losses percent also decreased. This is due to the solvent ability that dissolves the base oil in waste lubricating oil and determines the best SOR (Solvent Oil Ratio and extraction temperatures.

  1. Fast enantioselective separation of clevidipine and a dihydropyridine substituted acid by SFC on Chiralpak AD.

    Science.gov (United States)

    Gyllenhaal, O

    2001-01-01

    Conditions for the fast separation of the enantiomers of a dihydropyridine substituted acid on a 50 x 4.6 mm ID short Chiralpak AD column with 2-propanol modified carbon dioxide as the mobile phase are presented. A high throughout of samples can be accomplished through the continuous sample loading of the loop of the injector. If a continuous data collection was used 10 separations could be performed in about 5 min with a precision of 0.6% RSD for the area ratio (n = 10). The parent drug clevidipine can also be analyzed and its enantiomeric composition determined after alkaline hydrolysis into its acid, either through hydrolysis followed by extraction to dichloromethane or by direct analysis of the hydrolysis media. About 1 min is required for each run. Using 0.1 M of methanolic sodium hydroxide 2 min are sufficient for the hydrolysis, and, including weighing, only 5 min are required to analyze clevidipine.

  2. Síntesis y estudio fotoquímico de los derivados de 3-(E-alquenil-4-metoxifenilacetanilidas y 2-(E-alquenil-4-nitroanisoles

    Directory of Open Access Journals (Sweden)

    Neudo Urdaneta

    2013-05-01

    Full Text Available This work presents the synthesis and photochemical study of 3-(E-alkenyl-4-methoxyphenylacetanilide 3a-c and 2-(E-alkenyl-4-nitroanisole 3d-f derivatives. These compounds were prepared using the palladium catalyzed cross-coupling Suzuki-Miyaura type reaction of 4-methoxy-2-bromo-phenylacetanilide (1a, 2-bromo-4-nitro-anisol (1b and three E-1-alkenylboronic acids (2a-c. Compounds 3a and 3e were photolabile in 2-propanol. Molar extinction coefficients of 3a and 3e were 300.7M-1 cm-1 (λmax 315nm and 1505 M-1 cm-1 (λmax 295nm, respectively. Photodegradation of 3e yielded 2-methoxy-5-nitrobenzaldehyde, which was likely produced by oxidative rupture of the exocyclic double bond.

  3. Solvent-induced chirality control in the enantioseparation of 1-phenylethylamine via diastereomeric salt formation.

    Science.gov (United States)

    Kodama, Koichi; Kimura, Yuria; Shitara, Hiroaki; Yasutake, Mikio; Sakurai, Rumiko; Hirose, Takuji

    2011-04-01

    Solvent-induced chirality control in the enantioseparation of 1-phenylethylamine 1 by N-(p-toluenesulfonyl)-(S)-phenylalanine 2 via diastereomeric salt formation was studied. (S)-1·(S)-2 was preferentially crystallized as a less-soluble salt from aqueous alcohol, while (R)-1·(S)-2 salt was mainly obtained by addition of solvents with a six-membered ring such as dioxane, cyclohexane, tetrahydropyran, and cyclohexene to 2-propanol. Further investigations were carried out from the viewpoints of molecular structures, optical rotation measurement, and X-ray crystallographic analyses. Crystallographic analyses have revealed that incorporation of the six-membered ring solvent molecule in (R)-1·(S)-2 without hydrogen bonds changed the molecular conformation of (S)-2 to stabilize the salt, which changed the selectivity of 1 in the enantioseparation.

  4. Analysis of iodine in food samples by inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Todorov, Todor I; Gray, Patrick J

    2016-01-01

    This work shows a method for the determination of iodine in a variety of food samples and reference materials using inductively coupled plasma-mass spectrometry (ICP-MS) following alkaline extraction. Optimisation of the addition of organic carbon showed that a minimum of 3% 2-propanol was necessary for a constant ratio of iodine to internal standard. The limit of quantification (LOQ), calculated as 30σ for the method, was 36 ng g(-1) in solid food samples. For method validation, seven standard reference materials (SRM) and 21 fortified food samples were used. The precision (%RSD) of the measurements was in the 2-7% range. Accuracies for the SRMs were 85-105%, while the fortified food samples showed 81-119% recoveries, including a number of samples fortified at 50% of the LOQ.

  5. The Role of Fluorinated Alcohols as Mobile Phase Modifiers for LC-MS Analysis of Oligonucleotides

    Science.gov (United States)

    Basiri, Babak; van Hattum, Hilde; van Dongen, William D.; Murph, Mandi M.; Bartlett, Michael G.

    2016-09-01

    Hexafluoroisopropanol (HFIP) has been widely used as an acidic modifier for mobile phases for liquid chromatography-mass spectrometry (LC-MS) analysis of oligonucleotides ever since the first report of its use for this purpose. This is not surprising, considering the exceptional performance of HFIP compared with carboxylic acids, which cause significant MS signal suppression in electrospray ionization. However, we have found that other fluorinated alcohols can also be utilized for mobile phase preparation and the choice of optimal fluorinated alcohol is determined by the ion-pairing (IP) agent. Although HFIP is a very good choice to be used alongside less hydrophobic IP agents, other fluorinated alcohols such as 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol (HFMIP) can significantly outperform HFIP when used with more hydrophobic IP agents. We also found that more acidic fluorinated alcohols assist with the transfer of oligonucleotides with secondary structure (e.g., folded strands and hairpins) into the gas phase.

  6. Advances in the catalysts development in base of mixed oxides for control reactions of N{sub 2}O; Avances en el desarrollo de catalizadores a base de oxidos mixtos para reacciones de control de N{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M.A.; Perez, R.; Gomez, A.; Diaz, G. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, C.P. 11801 Mexico D.F. (Mexico)

    2000-07-01

    The catalytic supports Al{sub 2}O{sub 3}, La{sub 2}O{sub 3} and Al{sub 2}O{sub 3}-La{sub 2}O{sub 3} were prepared by the precipitation and coprecipitation techniques. The catalytic supports Al{sub 2}O{sub 3}, La{sub 2}O{sub 3} and Al{sub 2}O{sub 3}-La{sub 2}O{sub 3} were characterized by several techniques for to determine texture (BET), crystallinity (XRD), chemical composition (SEM), FTIR and it was evaluated their total acidity by the reaction with 2-propanol. It was continued with the cobalt addition by Impregnation and coprecipitation and it was evaluated its catalytic activity in the N{sub 2}O decomposition reaction. Also it was realized the N{sub 2}O reduction with Co using these catalysts. (Author)

  7. Extruded expanded polystyrene sheets coated by TiO2 as new photocatalytic materials for foodstuffs packaging

    Science.gov (United States)

    Loddo, V.; Marcì, G.; Palmisano, G.; Yurdakal, S.; Brazzoli, M.; Garavaglia, L.; Palmisano, L.

    2012-11-01

    Nanostructured, photoactive anatase TiO2 sol prepared under very mild conditions using titanium tetraisopropoxide as the precursor is used to functionalise extruded expanded polystyrene (XPS) sheets by spray-coating resulting in stable and active materials functionalised by TiO2 nanoparticles. Photocatalytic tests of these sheets performed in a batch reactor in gas-solid system under UV irradiation show their successful activity in degrading probe molecules (2-propanol, trimethylamine and ethene). Raman spectra ensure the deposition of TiO2 as crystalline anatase phase on the polymer surface. The presence of TiO2 with respect to polymer surface can be observed in SEM images coupled to EDAX mapping allowing to monitor the surface morphology and the distribution of TiO2 particles. Finally thermoforming of these sheets in industrial standard equipment leads to useful containers for foodstuffs.

  8. Research Update: A hafnium-based metal-organic framework as a catalyst for regioselective ring-opening of epoxides with a mild hydride source

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, Casey J.; Hassan Beyzavi, M.; Klet, Rachel C.; Hupp, Joseph T., E-mail: j-hupp@northwestern.edu, E-mail: o-farha@northwestern.edu [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 (United States); Farha, Omar K., E-mail: j-hupp@northwestern.edu, E-mail: o-farha@northwestern.edu [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 (United States); Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia)

    2014-12-01

    Reaction of styrene oxide with sodium cyanoborohydride and a catalytic amount of Hf-NU-1000 yields the anti-Markovnikov product, 2-phenylethanol, with over 98% regioselectivity. On the other hand, propylene oxide is ring opened in a Markovnikov fashion to form 2-propanol with 95% regioselectivity. Both styrene oxide and propylene oxide failed to react with sodium cyanoborohydride without the addition of Hf-NU-1000 indicative of the crucial role of Hf-NU-1000 as a catalyst in this reaction. To the best of our knowledge, this is the first report of the use of a metal-organic framework material as a catalyst for ring-opening of epoxides with hydrides.

  9. Conduction band energy level control of titanium dioxide: toward an efficient visible-light-sensitive photocatalyst.

    Science.gov (United States)

    Yu, Huogen; Irie, Hiroshi; Hashimoto, Kazuhito

    2010-05-26

    Through the use of a strategy that involves narrowing the TiO(2) band gap by shifting its conduction band positively and utilizing the catalytic activity of photoproduced Cu(I) for oxygen reduction, a novel visible-light-sensitive TiO(2) photocatalyst, Cu(II)-grafted Ti(1-3x)W(x)Ga(2x)O(2), was designed and synthesized. The Cu(II)/Ti(1-3x)W(x)Ga(2x)O(2) photocatalyst produced high activity under visible-light irradiation. In fact, it decomposed 2-propanol to CO(2) via acetone under visible light (>400 nm) with a high quantum efficiency of 13%. The turnover number for this reaction exceeded 22, indicating that it functioned catalytically.

  10. A Convenient Synthesis of Octahydro-pyrazino [ 1,2- a ] pyrazine

    Institute of Scientific and Technical Information of China (English)

    LIANG Feng; WU Xiao-Jun; ZHANG Shi-Wei; WU Cheng-Tai

    2003-01-01

    @@ The recent research results suggest that a series of octahydro-pyrazino[ 1,2-a ]pyrazines are useful as antiallergic agents.[1] Gubert et al. [2] developed a route from 1,4-dibenzyl-2-ethoxycarbonylpiperazine for the synthesis of this ring system. Under their conditions, this ring system was obtained with a low overall yield in six steps. Optimization of synthetic route to this ring system is still desirable. In this paper, we presented an efficient synthesis of octahydropyrazino[1,2-a]pyrazine by a new and efficient method starting from 1,3-dichloro-2-propanol and N-tosylated diethylenetriamine. The structure of title compound was determined by spectroscopy and X-ray diffraction technique.

  11. LET and dose rate effect on radiation-induced copolymerization in physical gel

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Seiko, E-mail: Nakagawa.Seiko@iri-tokyo.jp [Tokyo Metropolitan Industrial Technology Research Institute, 2-4-10 Aomi, Koto-ku, Tokyo 135-0064 (Japan); Taguchi, Mitsumasa; Kimura, Atsushi; Nagasawa, Naotsugu; Hiroki, Akihiro [Environmental Radiation Processing Group, Environment and Industrial Materials Research Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2014-09-01

    Highlights: •LET and dose rate effect on polymerization in gel was almost the same as in solution. •The ratio of the dose rate effect in the gel was higher than that in solution. •The initiation and termination processes show the difference on the dose rate effect. -- Abstract: N{sub 2}-saturated 2-propanol solutions containing styrene and maleimide were gelled by the addition of hydroxypropylcellulose and irradiated by proton, He and C-ion beams. The trend in the dose rate and LET effects on the yield and molecular weight distribution of the polymer produced in the gel was almost the same in the solution. On the contrary, the dose rate effect in the gel was higher than that in the solution. This effect was accelerated for irradiations by proton as well as heavier ion with a higher LET value.

  12. The continuous acid-catalyzed dehydration of alcohols in supercritical fluids: A new approach to the cleaner synthesis of acetals, ketals, and ethers with high selectivity

    Energy Technology Data Exchange (ETDEWEB)

    Gray, W.K.; Smail, F.R.; Hitzler, M.G.; Ross, S.K.; Poliakoff, M.

    1999-11-24

    This report describes a new a continuous method for forming ethers, acetals and ketals using solid acid catalysts, DELOXAN ASP or AMBERLYST 15, and supercritical fluid solvents. In the case of ether formation, the authors observe a high selectivity for linear alkyl ethers with little rearrangement to give branches ethers. Such rearrangement is common in conventional synthesis. The approach is effective for a range of n-alcohols up to n-octanol and also for the secondary alcohol 2-propanol. In the reaction of phenol with an alkylating agent, the continuous reaction can be tuned to give preferential O- or C-alkylation with up to 49% O-alkylation with supercritical propene. The authors also investigate the synthesis of a range of cyclic ethers and show an improved method for the synthesis of THF from 1,4-butandiol under very mild conditions.

  13. Catalytic activity of carbon nanotubes in the conversion of aliphatic alcohols

    Science.gov (United States)

    Zhitnev, Yu. N.; Tveritinova, E. A.; Chernyak, S. A.; Savilov, S. V.; Lunin, V. V.

    2016-06-01

    Carbon nanotubes (CNTs) obtained via the catalytic pyrolysis of hexane at 750°C were studied as the catalysts in conversion of C2-C4 alcohols. The efficiency of CNTs as catalysts in dehydration and dehydrogenation of ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and tert-butanol was studied by means of pulse microcatalysis. The surface and structural characteristics of CNTs are investigated via SEM, TEM, DTA, BET, and XPS. CNTs are shown to be effective catalysts in the conversion of alcohols and do not require additional oxidative treatment. The regularities of the conversion of aliphatic alcohols, related to the properties of the CNTs surface and the structure of the alcohols are identified.

  14. Enantioselective and diastereoselective separation of synthetic pyrethroid insecticides on a novel chiral stationary phase by high-performance liquid chromatography.

    Science.gov (United States)

    Tan, Xulin; Hou, Shicong; Wang, Min

    2007-07-01

    A novel chiral packing material for high-performance liquid chromatography (HPLC) was prepared by connecting (R)-1-phenyl-2-(4-methylphenyl) ethylamine (PTE) amide derivative of (S)-isoleucine to aminopropyl silica gel through 2-amino-3,5-dinitro-1-carboxamido-benzene unit. This chiral stationary phase was applied to the enantioselective and diastereoselective separation of five pyrethroid insecticides by HPLC under normal phase condition. To achieve satisfactory baseline separation an optimization of the variables of mobile phase composition was required. The two enantiomers of fenpropathrin and four stereoisomers of fenvalerate were baseline separated using hexane-1,2-dichloroethane-2-propanol as mobile phase. The results show that the enantioselectivity of CSP is better than Pirkle type 1-A column for these compounds. Only partial separations for the cypermethrin and cyfluthrin stereoisomers were observed. Seven peaks and eight peaks were observed for cypermethrin and cyfluthrin, respectively. The elution orders were assigned by using different stereoisomer-enriched products.

  15. Algorithms for GPU-based molecular dynamics simulations of complex fluids: Applications to water, mixtures, and liquid crystals.

    Science.gov (United States)

    Kazachenko, Sergey; Giovinazzo, Mark; Hall, Kyle Wm; Cann, Natalie M

    2015-09-15

    A custom code for molecular dynamics simulations has been designed to run on CUDA-enabled NVIDIA graphics processing units (GPUs). The double-precision code simulates multicomponent fluids, with intramolecular and intermolecular forces, coarse-grained and atomistic models, holonomic constraints, Nosé-Hoover thermostats, and the generation of distribution functions. Algorithms to compute Lennard-Jones and Gay-Berne interactions, and the electrostatic force using Ewald summations, are discussed. A neighbor list is introduced to improve scaling with respect to system size. Three test systems are examined: SPC/E water; an n-hexane/2-propanol mixture; and a liquid crystal mesogen, 2-(4-butyloxyphenyl)-5-octyloxypyrimidine. Code performance is analyzed for each system. With one GPU, a 33-119 fold increase in performance is achieved compared with the serial code while the use of two GPUs leads to a 69-287 fold improvement and three GPUs yield a 101-377 fold speedup.

  16. Combined supercritical fluid extraction/solid-phase extraction with octadecylsilane cartridges as a sample preparation technique for the ultratrace analysis of a drug metabolite in plasma.

    Science.gov (United States)

    Liu, H; Cooper, L M; Raynie, D E; Pinkston, J D; Wehmeyer, K R

    1992-04-01

    Supercritical fluid extraction was coupled with solid-phase extraction using octadecylsilane cartridges for the selective isolation of ultratrace levels of a drug metabolite, mebeverine alcohol, from plasma. Plasma was directly applied to the extraction cartridge, the cartridge was washed to remove protein and then extracted under supercritical conditions using CO2/5% methanol. The effluent from the extraction cell was bubbled through a small volume of 2-propanol to trap the extracted mebeverine alcohol. The effects of extraction pressure and temperature on analyte recovery were examined. The absolute recovery, selectivity, precision, and accuracy of the combined supercritical fluid extraction/solid-phase extraction approach were compared to those of conventional solid-phase extraction using gas chromatography/mass spectrometry in the selected-ion monitoring mode. Mebeverine alcohol was used as a model compound, and dog plasma was employed as the biological matrix for these studies.

  17. Isomerización de n-Pentano mediante óxidos de circonio dopados con ión borato

    OpenAIRE

    L. A. Cortez-Lajas; J. M. Hernández-Enríquez; A. Castillo-Mares; J. L. Rivera-Armenta; G. Sandoval-Robles; L. A. García-Serrano; R. García-Alamilla

    2006-01-01

    Se sintetizaron hidróxido de circonio puro y modificado con un 15% de iones borato. Ambos se calcinaron en atmósfera dinámica de aire durante 3 h a 400, 500 y 600ºC. Los soportes se caracterizaron mediante fisisorción de nitrógeno, espectroscopía infrarroja, titulación potenciométrica con n-butilamina y deshidratación del 2-propanol. Después de la calcinación los soportes se impregnaron con 0.5% peso de platino y se probaron en isomerización de n-pentano a presión atmosférica. La acidez de la...

  18. Radiation-induced pink nickel oligomeric clusters in water. Pulse radiolysis study.

    Science.gov (United States)

    Hioul, Mohamed Larbi; Lin, Mingzhang; Belloni, Jacqueline; Keghouche, Nassira; Marignier, Jean-Louis

    2014-10-09

    γ-rays and pulse radiolysis of aqueous solutions of Ni(2+) ions in the presence of polyacrylate (PA(-)) and 2-propanol leads to the formation of metastable species absorbing at 540 nm that are ascribed to "pink" oligomeric clusters of a few nickel atoms only. The molar absorption coefficient is evaluated as ε540 nm = 3300 ± 300 L mol(-1) cm(-1) per Ni(0) atom. The successive steps from the reduction of Ni(2+) into Ni(+) ions to the formation of the pink clusters at 540 nm under conditions of complexation by PA(-) are investigated by pulse radiolysis. The yield of the formation of pink clusters increases markedly with the irradiation dose rate, demonstrating the occurrence of the disproportionation of the [Ni(+), PA(-)] complex after a single electron pulse. The reduction and nucleation mechanisms, including rate constants, in competition with the back oxidation by protons, particularly at low dose rate, are discussed.

  19. Enantiomer Separation of α-Dimethyl Dicarboxylate Biphenyl and Related Biphenyl Compounds by Normal Phase HPLC on Polysaccharide Based Chiral Stationary Phases

    Institute of Scientific and Technical Information of China (English)

    LIU,Yue-Qi(刘月启); HAN,Xiao-Qian(韩小茜); Qi,Bang-Feng(齐邦峰); LIU,Chun-Hui(柳春辉); LI,Yong-Min(李永民); CHEN,Li-Ren(陈立仁)

    2002-01-01

    Cellulose tris(4-methylphenylcarbamate), amylose tris(3,5-dimethylpphenylcarbamate) and amylose tris (phenylcarbamate)were prepared by the method reported by Okamoto and were coated onto an aminopropylated mesoporous spherical silica gel. These final products were used as chiral stationary phases of high performance liquid chromatography for the eighteen structurally related biphenyl conmpounds. The resolution was made using normal-phase methodology with a mobile phase consisting of n-hexane-alcohol (ethanol, 1-propanol, 2-propanol or 1-butanol). The effects of various aliphatic alcohols in the mobile phase were studied. The structural features of the solutes that influence their k'were discussed. A dominant effect of trifluoroaetic acid on chiral separation of aacidicdic solutes was noted.

  20. Degradation and miscibility of poly(DL-lactic acid)/poly(glycolic acid) composite films: Effect of poly(DL-lactic-co-glycolic acid)

    Indian Academy of Sciences (India)

    Zhigang Ma; Na Zhao; Chengdong Xiong

    2012-08-01

    The in vitro degradation behaviour of poly(glycolic acid) (PGA) and its composite films containing poly(DL-lactic acid) (PDLLA) and poly(DL-lactic-co-glycolic acid) (PDLGA) were investigated via mass loss, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). All the films were prepared by solution casting, using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as the solvent. Since the degradation rate of PDLLA is lower than that of PGA, those of the PDLLA/PGA composite films decreased. As a compatibilizer, PDLGA improved the compatibility and hydrolytic stability of PDLLA/PGA composite films. Changes in the composite films indicate that this kind of PGA-based composite biomaterial may be applicable to device design for clinical application in the future.

  1. Characterization of catalytic supports based in mixed oxides for control reactions of NO and N{sub 2}O; Caracterizacion de soportes cataliticos basados en oxidos mixtos para reacciones de control de NO y N{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Garcia C, M.A.; Perez H, R.; Gomez C, A.; Diaz, G. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1999-07-01

    The catalytic supports Al{sub 2}O{sub 3}, La{sub 2}O{sub 3} and Al{sub 2}O{sub 3}-La{sub 2}O{sub 3} were prepared by the Precipitation and Coprecipitation techniques. The catalytic supports Al{sub 2}O{sub 3}, La{sub 2}O{sub 3} and Al{sub 2}O{sub 3}-La{sub 2}O{sub 3} were characterized by several techniques to determine: texture (Bet), crystallinity (XRD), chemical composition (Sem)(Ftir) and it was evaluated their total acidity by reaction with 2-propanol. The investigation will be continued with the cobalt addition and this will be evaluated for its catalytic activity in control reactions of N O and N{sub 2}O. (Author)

  2. Influence of microflora on texture and contents of amino acids, organic acids, and volatiles in semi-hard cheese made with DL-starter and propionibacteria

    DEFF Research Database (Denmark)

    Rehn, Lina Ulrika Ingeborg; Vogensen, Finn Kvist; Persson, S.-E.;

    2011-01-01

    for the cheese variety Grevé was obtained by using a PAB culture in combination with different DL-starters and making the cheeses at 2 dairy plants with different time and temperature profiles during ripening. Propionic acid bacteria dominated the microflora during ripening after a warm room period at levels......The microflora of semi-hard cheese made with DL-starter and propionic acid bacteria (PAB) is quite complex, and we investigated the influence of its variation on texture and contents of organic acids, free amino acids, and volatile compounds. Variation in the microflora within the normal range......, propionate, total content of free amino acids, 2-propanol, and ethyl propionate in the ripened cheeses were related to the number of PAB. A decrease in the relative content of Asp and Lys and increase of Phe over the ripening time were different from what is observed in semi-hard cheese without PAB...

  3. Justification of the solvent choice for the industrial amizon substance production

    Directory of Open Access Journals (Sweden)

    V. A. Georgiyants

    2014-08-01

    Full Text Available INTRODUCTION In recent years, the rapid development gets implementing principles of quality management in the pharmaceutical industry. It should be noted that instead of the mechanical control of the quality associated with the chemical characteristics of pharmaceutical substances and drugs innovative ways to ensure the quality associated primarily with the understanding of the processes occurring during the manufacturing process come. Objective: To study solvent selection for the industrial production of methiodide benzyl amide isonicotinic acid substance considering the conception “Quality by design”. MATERIALS AND METHODS Solution of 0.1 moles of isonicotinic acid in 0.12 moles of benzylamine was heated at 160-185°C during 4-5 hours while distilling off water and excess benzylamine. The resulting melt - cooled isonicotinic acid benzylamide was dissolved in acetone and filtered. It was used in further synthesis without further purification. 0.1 moles of isonicotinic acid benzylamide was dissolved in0.6 litersof a suitable solvent and 0.12 mole of methyl iodide was added to the solution at room temperature. The mixture was heated at 40-50 ° C for 3-4 hours, the reaction mixture was cooled, filtered the product was dried. After calculating the aim product was recrystallized from an appropriate solvent. Isonicotinic acid benzylamide iodomethylate quantitative content was determined by acid-base titration in non-aqueous medium (fixing the endpoint - potentiometrically. The impurity content benzylamide isonicotinic acid – by HPLC. RESULTS AND DISCUSSION When solvent have been chosen we took into account previously developed scheme of laboratory synthesis. We guided primarily data about security and efficiency. The least toxic solvents conventionally used in pharmaceutical production , included 2- propanol and ethanol (limit of residual amounts of these solvents, allowable HFC substances was 0.5 % and 1 %, respectively. Therefore, these

  4. Hybrid pigments resulting from several guest dyes onto γ-alumina host: A spectroscopic analysis

    Science.gov (United States)

    Pérez, Erik; Ibarra, Ilich A.; Guzmán, Ariel; Lima, Enrique

    2017-02-01

    The synthesis of hybrid pigments was made from combination of γ-Al2O3 and some organic chromophores such as carminic acid, alizarin, purpurin, curcumin, fluorescein and betacyanins. The γ-Al2O3 was obtained through sol-gel synthesis with 2-propanol and aluminium tri-sec-butoxide (ATB). This article presents some spectroscopic evidences related to the formation of aluminium complexes between coordinative unsaturated sites (CUS) of aluminium and some organic groups (carboxylic acid, quaternary ammonium and β-keto enol) present in the chromophores structure. The physicochemical properties upcoming from a spectroscopic analysis point out that these materials can be applied in the design of new materials with potential uses in artworks and in the field of cultural heritage.

  5. Transition metal complexes of 5-bromosalicylidene-4-amino-3-mercapto-1,2,4-triazine-5-one: Synthesis, characterization, catalytic and antibacterial studies

    Directory of Open Access Journals (Sweden)

    AYALOOR SUBRAMANIAN RAMASUBRAMANIAN

    2011-01-01

    Full Text Available Transition metal complexes of 5-bromosalicylidene-4-amino-3-mercapto-1,2,4-triazine-5-one with metal precursors, such as Cu(II, Ni(II, Co(II and Pd(II, were synthesized and characterized by physico–chemical and spectroscopic techniques. All the complexes are of the ML type. Based on analytical, spectral data and magnetic moments, the Co(II and Ni(II complexes were assigned octahedral geometries, while the Cu (II and Pd(II complexes square planar. A study on the catalytic oxidation of benzyl alcohol, cyclohexanol, cinnamyl alcohol, 2-propanol and 2-methyl-1-propanol was performed with N-methylmorpholine-N-oxide (NMO as co-oxidant. All the complexes and their parent organic moiety were screened for their biological activity on several pathogenic bacteria and were found to possess appreciable bactericidal properties.

  6. Synergetic effect of TeMo5O16 and MoO3 phases in MoTeOx catalysts used for the partial oxidation of propylene

    Institute of Scientific and Technical Information of China (English)

    Yiming He; Ying Wu; Weizheng Weng; Huilin Wan

    2011-01-01

    A detailed study on the synergetic effect of TeMo5O16 and MoO3 phases in the MoTeOx catalysts for the partial oxidation of propylene to acrolein has been reported in this work. It was found that both propylene conversion and acrolein selectivity increased with the addition of MoO3 to TeMo5O16. Based on the results of N2 adsorption-desorption, XRD, XPS, in-situ XRD, O2-TPO, and 2-propanol decomposition reaction, the higher catalytic performance and synergetic effect could be attributed to the enhancement of acidity and the oxygen transfer from TeMo5O16 to MoO3 phase.

  7. An Oxygen Reduction Study of Graphene-Based Nanomaterials of Different Origin

    Directory of Open Access Journals (Sweden)

    Jaana Lilloja

    2016-07-01

    Full Text Available The aim of this study is to compare the electrochemical behaviour of graphene-based materials of different origin, e.g., commercially available graphene nanosheets from two producers and reduced graphene oxide (rGO towards the oxygen reduction reaction (ORR using linear sweep voltammetry, rotating disc electrode and rotating ring-disc electrode methods. We also investigate the effect of catalyst ink preparation using two different solvents (2-propanol containing OH− ionomer or N,N-dimethylformamide on the ORR. The graphene-based materials are characterised by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. Clearly, the catalytic effect depends on the origin of graphene material and, interestingly, the electrocatalytic activity of the catalyst material for ORR is lower when using the OH− ionomer in electrode modification. The graphene electrodes fabricated with commercial graphene show better ORR performance than rGO in alkaline solution.

  8. Pharmacokinetic study of inosiplex tablets in healthy Chinese volunteers by hyphenated HPLC and tandem MS techniques

    Institute of Scientific and Technical Information of China (English)

    Mo Chen; Yuan Zhang; Xiao-Ting Que; Ya Ding; Lin Yang; Ai-Dong Wen; Tai-Jun Hang

    2013-01-01

    Inosiplex is a compound formulation composed of inosine and p-acetaminobenzoic acid (PABA) salt of N,N-dimethylamino-2-propanol (DIP). This study was to investigate the clinical plasma pharmacokinetic properties of DIP and PABA after single and multiple oral doses of inosiplex tablets in healthy Chinese volunteers. The established LC/MS/MS method for plasma DIP determination had a linear range of 0.02-10 mg/mL, and the HPLC method for plasma PABA determination had a linear range of 0.05-40 mg/mL. Linear pharmacokinetic characteristics were found with single oral doses of 0.5, 1.0 and 2.0 g. No obvious accumulation effects were observed for DIP and PABA.

  9. Photoelectron circular dichroism of isopropanolamine

    Science.gov (United States)

    Catone, D.; Turchini, S.; Contini, G.; Prosperi, T.; Stener, M.; Decleva, P.; Zema, N.

    2017-01-01

    Spectroscopies based on circular polarized light are sensitive to the electronic and structural properties of chiral molecules. Photoelectron circular dichroism (PECD) is a powerful technique that combines the chiral sensitivity of the circular polarized light and the electronic information obtained by photoelectron spectroscopy. An experimental and theoretical PECD study of the outer valence and C 1s core states of 1-amino-2-propanol in the gas phase is presented. The experimental dichroic dispersions in the photoelectron kinetic energy are compared with theoretical calculations employing a multicentric basis set of B-spline functions and a Kohn-Sham Hamiltonian. In order to understand analogies and differences in the dichroism of structural isomers bearing the same functional groups, a comparison with previous PECD study of valence band of 2-amino-1-propanol is carried out.

  10. Design and synthesis of novel triazole antifungal derivatives based on the active site of fungal lanosterol 14a-demethylase (CYP51)

    Institute of Scientific and Technical Information of China (English)

    Zhi Gang Dan; Jun Zhang; Shi Chong Yu; Hong Gang Hu; Xiao Yun Chai; Qing Yan Sun; Qiu Ye Wu

    2009-01-01

    A series of 1-(1H-1,2,4-triazole-1-yl)-2-(2,4-difluorophenyl)-3-(N-isoproyl-N-substituted-amino)-2-propanols have been designed and synthesized on the basis of the active site of lanosterol 14a-demethylase (CYP51). Their structures were confirmed by MS and 1H NMR. In vitro antifungal activities of these synthesized compounds were evaluated against eight human pathogenic fungi. The results showed that all title compounds exhibited activity against fungi tested to some extent. Compounds 3c, 3d, 7a, 7b and 7c exhibited more potent antifungal activities against nearly all fungi tested except Aspergillus fumigatus than fluconazole.

  11. Synthesis of TiO2 Nanoparticles via a Ti(Ⅳ) Complex with Stearic Acid and the Photocatalytic Activity for Organic Oxidation

    Institute of Scientific and Technical Information of China (English)

    XU,Yi-Ming(许宜铭); YU,Xiao-Han(于小涵); LIU,Hui-Jun(刘惠君)

    2002-01-01

    The nano-sized particles of TiO2 were prepared by thermal decomposition of titanium(Ⅳ) tetrabutanoxide complex with stearic acid at 450 ℃ in the air. It was observed that the amount of stearic acid, used initially for the complex synthesis in 2-propanol at 25 ℃, had great influence on the physical properties of the prepared TiO2 including crystal structure,the particle size, surface area and the adsorption capacity for organic substrate of a textile dye X3B in water, and thereafter the photocatalytic activity for the dye oxidation. Some samples displayed lower adsorption capacity for the organic substrate in water than a TiO2 of Degussa p25, but higher photocatalytic activity for the organic oxidation. Possible reason for the observed difference was discussed in the text.

  12. Effects of dispersion solvent on the formation of silicon nanoparticles synthesized via microemulsion route

    Science.gov (United States)

    Liong, W. L.; Sreekantan, S.; Hutagalung, S. D.

    2010-05-01

    Silicon nanoparticles are synthesized by microemulsion route. Silicon tetrachloride (SiCl4) is used as a silicon source. Meanwhile, hydrazine (N2H5OH), sodium hydroxide (NaOH), and polyethylene glycol (PEG) are used as reduction agent, stabilizer, and capping agent, respectively. In this study, the effects of different solvents (methanol, 1-butanol, 2-propanol, ethanol, acetone, and toluene) on the dispersion and the stabilization of silicon nanoparticles are studied intensively. The results in this study show that ethanol solvent has given smaller particle size, better size distribution, stable suspension and well dispersion of silicon nanoparticles. The diameter of synthesized silicon nanoparticles is in the range of 30-100 nm. Moreover, the absorption edge of silicon nanoparticles in ethanol is observed at a shorter wavelength compared to the others solvent.

  13. Successive cycles of utilization of novozym 435 in three different reaction systems

    Energy Technology Data Exchange (ETDEWEB)

    Lerin, L.; Oestreicher, E. G. [Universidade Federal do Rio de Janeiro (IQ/UFRJ), RJ (Brazil). Inst. de Quimica; Ceni, G.; Richett, A.; Kubiak, G.; Oliveira, J. Vladimir; Toniazzo, G.; Treichel, H.; Oliveira, D., E-mail: helen@uricer.ed [Universidade Regional Integrada do Alto Uruguai e das Missoes (URI), Erechim, RS (Brazil)

    2011-04-15

    The main focus of this work was to investigate the residual esterification activity and the product conversion after 10 successive cycles of utilization of a commercial lipase in three systems: esterification of 2-ethyl hexanol and palmitic acid in a solvent-free system; esterification of ascorbic acid and palmitic acid in tert-butanol; and transesterification of glycerol and methyl benzoate in 2-propanol. These systems were chosen based on previous results by our research group in terms of product conversion. Before scale-up, there is a need for evaluating several cycles of utilization of the biocatalyst. The esterification of 2-ethyl hexanol showed that after 10 cycles the enzyme retained 90% of its activity. The system consisting of ascorbic acid, palmitic acid, Novozym 435 and tert-butanol showed that a reduction in enzyme activity was accompanied by a reduction in reaction conversion; the same behavior was not observed for the third system. (author)

  14. X-Ray structure and cytotoxic activity of a picolinate ruthenium(II–arene complex

    Directory of Open Access Journals (Sweden)

    IVANKA IVANOVIĆ

    2011-01-01

    Full Text Available A ruthenium(II–arene complex with picolinic acid, [(η6-p-cymeneRuCl(pico]∙H2O, was prepared by the reaction of [(η6-p-cymeneRuCl2]2 with picolinic acid in a 1:2 molar ratio in 2-propanol. The compound was characterized by elemental analysis, and IR and NMR spectroscopy. X-ray diffraction analysis showed that the molecule adopts a “three-leg piano-stool” geometry, which is common for this type of complexes. The cytotoxic activity of the complex was tested in two human cancer cell lines HeLa (cervix and FemX (melanoma by MTT assay. The IC50 values were at 82.0 and 36.2 µmol dm-3 for HeLa and FemX cells, respectively.

  15. Degradation of a recalcitrant xenobiotic compound: methyl tert-butyl ether (MTBE) metabolism by mycobacterium austroafricanum; Degradation d'un compose xenobiotique recalcitrant: metabolisme du methyl tert-butyl ether (MTBE) par mycobacterium austroafricanum IFP 2012

    Energy Technology Data Exchange (ETDEWEB)

    Francois, A.

    2002-11-01

    Methyl tert-butyl ether (MTBE) is introduced up to 15% (vol/vol) in gasoline in order to obtain a good octane number and to prevent carbon monoxide emissions. However, as a consequence of storage tanks leakage, MTBE became one of the major pollutants of aquifers because of its very low biodegradability. The present study aimed at investigating the biodegradation of MTBE by Mycobacterium austroafricanum IFP 2012. The MTBE metabolic pathway was partially elucidated owing to the identification of some intermediates (tert-butyl formate (TBF), tert-butyl alcohol (TBA), a-hydroxy-isobutyric acid and acetone) and some enzymatic activities (MTBE/TBA monooxygenase (non hemic and inducible), TBF esterase, 2-propanol: NDMA oxidoreductase and another monooxygenase involved in acetone degradation). The involvement of TBF and the requirement of cobalt could be explanations for the low natural attenuation of MTBE; whereas the methoxy group does not seem to be implicated. (author)

  16. PtRu/C Electrocatalysts Prepared Using Gamma and Electron Beam Irradiation for Methanol Electrooxidation

    Directory of Open Access Journals (Sweden)

    Dionisio F. Silva

    2012-01-01

    Full Text Available PtRu/C electrocatalysts (carbon-supported PtRu nanoparticles were prepared in a single step submitting water/2-propanol mixtures containing Pt(IV and Ru(III ions and the carbon support to gamma and electron beam irradiation. The electrocatalysts were characterized by energy dispersive X-ray analysis (EDX, X-ray diffraction (XRD, transmission electron microscopy (TEM, and cyclic voltammetry and tested for methanol electrooxidation. PtRu/C electrocatalyst can be prepared in few minutes using high dose rate electron beam irradiation while using low dose rate gamma irradiation some hours were necessary to prepare it. The obtained materials showed the face-centered cubic (fcc structure of Pt and Pt alloys with average nanoparticle sizes of around 3 nm. The material prepared using electron beam irradiation was more active for methanol electrooxidation than the material prepared using gamma irradiation.

  17. Enantiomeric resolution of p-toluenesulfonate of valine benzyl ester by preferential crystallizaion.

    Science.gov (United States)

    Munegumi, Toratane; Wakatsuki, Aiko; Takahashi, Yutaro

    2012-02-01

    Preferential crystallization of amino acid derivatives by seeding a pure enantiomer into racemic amino acid solutions has been studied for many years. However, few examples of valine derivatives have been reported so far. Although there have been some reports using valine hydrogen chloride with preferential crystallization, it is difficult to obtain optical isomers for valine derivatives using preferential crystallization. In this study, repeated preferential crystallization of p-toluenesulfonate valine benzyl ester with a 20% e.e. in 2-propanol gave a 94% e.e. on sonication. Sonication accelerated crystallization rate, but there was not a big difference in e.e. between with and without sonication. However, this research demonstrates the first preferential crystallization of p-toluenesulfonate of valine benzyl esters with an acceleration of crystallization using sonication.

  18. A method suitable for DNA extraction from humus-rich soil.

    Science.gov (United States)

    Miao, Tianjin; Gao, Song; Jiang, Shengwei; Kan, Guoshi; Liu, Pengju; Wu, Xianming; An, Yingfeng; Yao, Shuo

    2014-11-01

    A rapid and convenient method for extracting DNA from soil is presented. Soil DNA is extracted by direct cell lysis in the presence of EDTA, SDS, phenol, chloroform and isoamyl alcohol (3-methyl-1-butanol) followed by precipitation with 2-propanol. The extracted DNA is purified by modified DNA purification kit and DNA gel extraction kit. With this method, DNA extracted from humus-rich dark brown forest soil was free from humic substances and, therefore, could be used for efficient PCR amplification and restriction digestion. In contrast, DNA sample extracted with the traditional CTAB-based method had lower yield and purity, and no DNA could be extracted from the same soil sample with a commonly-used commercial soil DNA isolation kit. In addition, this method is time-saving and convenient, providing an efficient choice especially for DNA extraction from humus-rich soils.

  19. Lipase-catalyzed biodiesel synthesis with different acyl acceptors

    Directory of Open Access Journals (Sweden)

    Ognjanović Nevena D.

    2008-01-01

    Full Text Available Biodiesel is an alternative fuel for diesel engine that is environmentally acceptable. Conventionally, biodiesel is produced by transesterification of triglycerides and short alcohols in the presence of an acid or an alkaline catalyst. There are several problems associated with this kind of production that can be resolved by using lipase as the biocatalyst. The aim of the present work was to investigate novel acyl acceptors for biodiesel production. 2-Propanol and n-butanol have a less negative effect on lipase stability, and they also improve low temperature properties of the fuel. However, excess alcohol leads to inactivation of the enzyme, and glycerol, a major byproduct, can block the immobilized enzyme, resulting in low enzymatic activity. This problem was solved by using methyl acetate as acyl acceptor. Triacetylglycerol is produced instead of glycerol, and it has no negative effect on the activity of the lipase.

  20. Design, synthesis, and antifungal activities of novel triazole derivatives containing the benzyl group

    Directory of Open Access Journals (Sweden)

    Xu K

    2015-03-01

    Full Text Available Kehan Xu,1,* Lei Huang,1,* Zheng Xu,2 Yanwei Wang,1,3 Guojing Bai,1 Qiuye Wu,1 Xiaoyan Wang,1 Shichong Yu,1 Yuanying Jiang1 1School of Pharmacy, Second Military Medical University, Shanghai, 2Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 3Number 422 Hospital of PLA, Zhanjiang, People’s Republic of China *These authors contributed equally to this work Abstract: In previous studies undertaken by our group, a series of 1-(1H-1,2,4-triazole-1-yl-2-(2,4-difluorophenyl-3-substituted-2-propanols (1a–r, which were analogs of fluconazole, was designed and synthesized by click chemistry. In the study reported here, the in vitro antifungal activities of all the target compounds were evaluated against eight human pathogenic fungi. Compounds 1a, 1q, and 1r showed the more antifungal activity than the others. Keywords: triazole, synthesis, antifungal activity, CYP51

  1. ANALYSIS OF OUT OF DATE MCU MODIFIER LOCATED IN SRNL

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, C.

    2014-10-22

    SRNL recently completed density measurements and chemical analyses on modifier samples stored in drums within SRNL. The modifier samples date back to 2008 and are in various quantities up to 40 gallons. Vendor information on the original samples indicates a shelf life of 5 years. There is interest in determining if samples that have been stored for more than the 5 year shelf life are still acceptable for use. The Modular Caustic Side Solvent Extraction Unit (MCU) Solvent component Cs-7SB [(2,2,3,3- tetraflouropropoxy)-3-(4-sec-butylphenoxy)-2-propanol, CAS #308362-88-1] is used as a diluent modifier to increase extractant solubility and provide physical characteristics necessary for diluent trimming.

  2. Measurements of Conductivity for Low Concentration Strong- electrolytes in Organic Solvents (I) LiBr, LiCI, and LiNO3 in Alcohols%Measurements of Conductivity for Low Concentration Strong- electrolytes in Organic Solvents (I) LiBr, LiCI, and LiNO3 in Alcohols

    Institute of Scientific and Technical Information of China (English)

    陈红; 王利生; 姜波; 李弥异

    2012-01-01

    The conductivities of LiBr, LiCl, and LiNO 3 in methanol, ethanol, 1-propanol, and 2-propanol (with electrolyte concentrations 〈0.08 mol·L-1 ) were determined at 298.15 K, 313.15 K, and 323.15 K at atmosphere pressure separately by using a conductivity meter. The conductivity data were correlated with Foss-Chen-Justice (FCJ) equation and the limiting molar conductivities were obtained. The mean ionic activity coefficients of the salts in the organic solvents were calculated according to the Debye-Hückel limiting law and Onsager-Falkenhangen equations. The calculated results were compared with those activity coefficients in literature.

  3. Dependence on molecular parameters of the heat capacity critical behaviour for nitroalkane + alcohol binary systems

    Science.gov (United States)

    Souto-Caride, M.; Troncoso, J.; Losada-Pérez, P.; Peleteiro, J.; Carballo, E.; Romani, L.

    2009-04-01

    Heat capacities per unit volume for a set of nitroalkane + alcohol critical mixtures near their upper consolute point are presented. The selected nitroalkanes were nitromethane and nitroethane whereas the 1-alcohol series from 1-propanol to 1-decanol was studied. The critical anomaly of nitroalkane + non-primary alcohols was also investigated; 2-propanol, 2-pentanol, 3-pentanol and 5-nonanol were chosen to this end. The heat capacity data are obtained at atmospheric pressure as a function of temperature in the homogeneous and heterogeneous regions by means of a differential scanning calorimeter. The exponent and amplitudes that characterises the observed critical anomaly are determined from experimental data, being their values coherent with previous results. In addition, the critical amplitude of the correlation length was calculated using the universality of the two-scale factor. Finally, the changes in the critical parameters as a function of the molecular structure of both nitroalkane and alcohol are analysed.

  4. The effect of the presence of alcohol in the dispersing phase of oxide sols on the properties of RuO2-TiO2/Ti anodes obtained by the sol–gel procedure

    Directory of Open Access Journals (Sweden)

    R. ATANASOSKI

    2000-09-01

    Full Text Available The effect of the addition of ethanol and 2-propanol to the dispersing phase of TiO2 and RuO2 sols mixture on the morphology and, consequently, on the electrochemical properties of the sol-gel obtained activated titanium anodes was investigated. The properties of the obtained anodes were compared to those obtained by the thermal decomposition of appropriate chloride salts. The morphology of the anode coatings was examined by scanning tunneling microscopy. The electrochemical behaviour was investigated by cyclic voltammetry and by polarization measurements. An accelerated stability test was used for the examination of the stability of the anodes under simultaneous oxygen and chlorine evolution reaction. A dependence of the anode stability on the type of added alcohol is indicated.

  5. Research Update: A hafnium-based metal-organic framework as a catalyst for regioselective ring-opening of epoxides with a mild hydride source

    Directory of Open Access Journals (Sweden)

    Casey J. Stephenson

    2014-12-01

    Full Text Available Reaction of styrene oxide with sodium cyanoborohydride and a catalytic amount of Hf-NU-1000 yields the anti-Markovnikov product, 2-phenylethanol, with over 98% regioselectivity. On the other hand, propylene oxide is ring opened in a Markovnikov fashion to form 2-propanol with 95% regioselectivity. Both styrene oxide and propylene oxide failed to react with sodium cyanoborohydride without the addition of Hf-NU-1000 indicative of the crucial role of Hf-NU-1000 as a catalyst in this reaction. To the best of our knowledge, this is the first report of the use of a metal-organic framework material as a catalyst for ring-opening of epoxides with hydrides.

  6. Preparation and Catalytic Properties of Polymer Supported Dendritic Metal Complex

    Institute of Scientific and Technical Information of China (English)

    LI Cui-ling; YANG Zhi-wang; KANG Qiao-xiang; MA Heng-chang; MA Xiao-peng; GAO Qi-kuan; GUO Zhen; LEI Zi-qiang

    2004-01-01

    Polymer supported materials are extensively used as oxidizing agent, reducing agent catalysts, photosensitizers ion exchange resins and agriculturally and pharmacologically active agents1. The application of polymer metal complexes has been widely investigated2. The polymer supported complex undergoes swelling in a suitable solvent medium and provides enough surface area in carrying out electron transfer reactions, which clearly emphasizes the influence of a polymer network in heterogeneous catalysis.In the present, we have succeeded in the grafting of "dendrimer-like" hyperbranched polymer onto the surface of chloromethyl polystyrene reactions.All the catalysts show promising catalytic activities for the oxidation of iso-propylbenzene in the mild reaction condition, in each case, hypnone 1, 2-phenyl-2-propanol 2 were obtained as the major products

  7. Direct optical observation of the formation of some aliphatic alcohol radicals. A pulse radiolysis study

    Indian Academy of Sciences (India)

    E Janata

    2002-12-01

    The kinetics of the reactions of hydroxyl radicals and hydrogen atoms with some aliphatic alcohols in aqueous solutions were studied using pulse radiolysis. Based on the increase in optical absorption in the UV region, the rate constants for the reaction of hydroxyl radicals and hydrogen atoms with methanol, ethanol, 2-propanol or -butyl alcohol were determined to be 9.0 × 108, 2.2 × 109, 2.0 × 109, 6.2 × 108 and 1.1 × 106, 1.8 × 107, 5.3 × 107, 2.3 × 105 dm3 mol-1 s-1 respectively. The bimolecular decay rate constants for the alcohol radicals produced in methanol and ethanol were evaluated to be 2 .4 × 109 and 1.5 × 109 dm3 mol-1 s-1. The values observed are in fairly good agreement with those reported earlier.

  8. "Phase diagrams of Lecithin-based microemulsions containing Sodium Salicylate "

    Directory of Open Access Journals (Sweden)

    "Aboofazeli R

    2000-08-01

    Full Text Available Partial phase diagrams were constructed at 25°C to investigate the phase behaviour of systems composed of soybean lecithin, water, sodium salicylate, alcohol and isopropyl myristate. The lecithins used were the commercially available soy bean lecithins, namely E200 and E170 (phosphatidyl choline purities greater than 95% and 68-72% respectively. The cosurfactants employed were n-propanol, 2-propanol and n-butanol and these were used at lecithin/alcohol weight ratios (Km of 1:1 and 1.5:1. At a given Km, the aqueous phase consisted of a 2% w/w sodium salicylate solution. Phase diagrams showed the area of existence of a stable isotropic region along the surfactant/oil axis (i.e., reverse microemulsion area. The extension of the microemulsion domain was influenced by the purity of surfactant, the lecithin/alcohol weight ratios and the kind of the alcohol.

  9. Obtención de Dímeros por Termólisis de 1,2-Propanodiol Synthesis of Dimers from Thermolysis of 1,2-Propanediol

    Directory of Open Access Journals (Sweden)

    Nathaly Milanés

    2012-01-01

    Full Text Available Los compuestos dímeros 3-oxi-(bis-2-propanol, 2-(2-hidroxipropoxi-propanol y 2-oxi-(bis-propanol fueron obtenidos de la reacción de descomposición térmica del 1,2-propanodiol, realizada a 573.15 K y a su presión de vapor, utilizando un sistema de reacción a microescala, Los dímeros resultaron ser isómeros y fueron elucidados por cromatografía gaseosa acoplada a espectrometría de masas. E stos compuestos no han sido reportados en la literatura como productos de termólisis de polioles. La cinética y el mecanismo, fueron confirmados por cálculos computacionales utilizando el método de la Teoría del Funcional Densidad, DFT. E l mecanismo propuesto transcurrió a través de un proceso concertado de una sola etapa, que pasa por un estado de transición cíclico de cuatro miembros , compatible con cálculos cinéticos y termodinámicos.The dimers 3-oxy-(bys-2-propanol, 2-(2-hydroxypropoxy-propanol and 2-oxy-(bys-propanol were obtained from the thermal decomposition reaction of 1,2-propanediol , at 573.15 K and to its vapor pressure, and using microscale reaction system. The dimers resulted to be isomers and were elucidated by gas chromatography coupled to mass spectrometry. These compounds have not been reported in literature as products polyol thermolysis. The kinetic and the mechanism were validated by computational calculations using the Density Functional Theory, DFT. The proposed mechanism occurred in a single step concerted process that passes through a four member transition cyclical state that is compatible with kinetic and thermodynamic calculations.

  10. Preparation and characterization of Pt catalysts supported on TiO{sub 2} and ZrO{sub 2} stabilized with La{sub 2}O{sub 3} for the elimination of nitric oxide; Preparacion y caracterizacion de catalizadores de Pt soportado en TiO{sub 2} y ZrO{sub 2} estabilizados con La{sub 2}O{sub 3} para la eliminacion de oxido nitrico

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar V, A

    2001-07-01

    The objective of this work is the preparation and characterization of catalytic materials with a platinum base, supported in simple and mixed oxides of titanium (TiO{sub 2}) and zirconia (ZrO{sub 2}) which were stabilized with 10 % in mole of lanthanum (La{sub 2}O{sub 3}), the preparation technique of the supports is the one of precipitation, additioning a nominal charge of 1% in weight of active phase (Pt) by means of the impregnation method by conventional wetting. All the solids were calcinated at 500 Centigrade and subsequently reduced to the same temperature in air and hydrogen flow respectively. Their characterization was applying the techniques such as: Thermal gravimetric analysis (TGA), Differential scanning calorimetry (DSC), Surface area (BET), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Decomposition of 2-propanol, Catalytic activity and selectivity. The application of these techniques allow to define and to explain the influence of the preparation method and of the thermal treatments to which were submitted the catalysts, in special the Surface area, X-ray diffraction and Scanning electron microscopy which demonstrated in evidence the morphologic structure and of crystalline phases present in the catalysts under study. The decomposition of 2-propanol, catalytic activity and selectivity show the supports and catalysts skill for the determination of acid or base sites, moreover of the selective reduction of nitric oxide respectively, the results seem to indicate that the preparation technique, precursors and the thermal treatments to what these materials were submitted have an influence on the catalyst and by consequence in the reduction reaction of nitric oxide. (Author)

  11. Influence of hydroxyl group position and temperature on thermophysical properties of tetraalkylammonium hydroxide ionic liquids with alcohols.

    Directory of Open Access Journals (Sweden)

    Pankaj Attri

    Full Text Available In this work, we have explored the thermophysical properties of tetraalkylammonium hydroxide ionic liquids (ILs such as tetrapropylammonium hydroxide (TPAH and tetrabutylammonium hydroxide (TBAH with isomers of butanol (1-butanol, 2-butanol and 2-methyl-2-propanol within the temperature range 293.15-313.15 K, with interval of 5 K and over the varied concentration range of ILs. The molecular interactions between ILs and butanol isomers are essential for understanding the function of ILs in related measures and excess functions are sensitive probe for the molecular interactions. Therefore, we calculated the excess molar volume (V(E and the deviation in isentropic compressibility (Δκs using the experimental values such as densities (ρ and ultrasonic sound velocities (u that are measured over the whole compositions range at five different temperatures (293.15, 298.15, 303.15, 308.15 and 313.15 K and atmospheric pressure. These excess functions were adequately correlated by using the Redlich-Kister polynomial equation. It was observed that for all studied systems, the V(E and Δκs values are negative for the whole composition range at 293.15 K. And, the excess function follows the sequence: 2-butanol>1-butanol>2-methyl-2-propanol, which reveals that (primary or secondary or tertiary position of hydroxyl group influence the magnitude of interactions with ILs. The negative values of excess functions are contributions from the ion-dipole interaction, hydrogen bonding and packing efficiency between the ILs and butanol isomers. Hence, the position of hydroxyl group plays an important role in the interactions with ILs. The hydrogen bonding features between ILs and alcohols were analysed using molecular modelling program by using HyperChem 7.

  12. Influence of hydroxyl group position and temperature on thermophysical properties of tetraalkylammonium hydroxide ionic liquids with alcohols.

    Science.gov (United States)

    Attri, Pankaj; Baik, Ku Youn; Venkatesu, Pannuru; Kim, In Tae; Choi, Eun Ha

    2014-01-01

    In this work, we have explored the thermophysical properties of tetraalkylammonium hydroxide ionic liquids (ILs) such as tetrapropylammonium hydroxide (TPAH) and tetrabutylammonium hydroxide (TBAH) with isomers of butanol (1-butanol, 2-butanol and 2-methyl-2-propanol) within the temperature range 293.15-313.15 K, with interval of 5 K and over the varied concentration range of ILs. The molecular interactions between ILs and butanol isomers are essential for understanding the function of ILs in related measures and excess functions are sensitive probe for the molecular interactions. Therefore, we calculated the excess molar volume (V(E) ) and the deviation in isentropic compressibility (Δκs ) using the experimental values such as densities (ρ) and ultrasonic sound velocities (u) that are measured over the whole compositions range at five different temperatures (293.15, 298.15, 303.15, 308.15 and 313.15 K) and atmospheric pressure. These excess functions were adequately correlated by using the Redlich-Kister polynomial equation. It was observed that for all studied systems, the V(E) and Δκs values are negative for the whole composition range at 293.15 K. And, the excess function follows the sequence: 2-butanol>1-butanol>2-methyl-2-propanol, which reveals that (primary or secondary or tertiary) position of hydroxyl group influence the magnitude of interactions with ILs. The negative values of excess functions are contributions from the ion-dipole interaction, hydrogen bonding and packing efficiency between the ILs and butanol isomers. Hence, the position of hydroxyl group plays an important role in the interactions with ILs. The hydrogen bonding features between ILs and alcohols were analysed using molecular modelling program by using HyperChem 7.

  13. Synthesis and dopamine transporter binding of 2beta-isopropyl ester analogs of cocaine.

    Science.gov (United States)

    El-Moselhy, Tarek F; Avor, Kwasi S; Basmadjian, Garo P

    2002-02-01

    A series of 2beta-isopropyl ester analogs of cocaine (7-11) was synthesised and evaluated in an in vitro dopamine transporter (DAT) binding assays. Ecgonine HCl (5) was obtained from (-)-cocaine (1) by hydrolysis using 1 N HCl. Acid catalysed esterification of 5 using 2-propanol and HCl gas afforded 2beta-isopropyl ecgonine (6). Compounds 7-9 were obtained via esterification of the 3beta-hydroxyl group of 6 using the appropriate acid chloride. Compound 10 was obtained via selective hydrolysis and re-esterification of 7 using 2-propanol and HCl gas. Compound 11 was obtained by reduction of 9 using H(2)/Pd-C. Compounds 7, 10 and 11 showed high binding affinity to the DAT (as indicated from the inhibition of the binding of [(3)H]WIN 35,428 (3)) with IC(50) values (mean +/- S.E.M.) 208.5 +/- 9.5, 47.43 +/- 1.79 and 11.25 +/- 3.37 nM, respectively). Compound 7 is comparatively as active as cocaine, 10 is ca. fivefold more active than cocaine and 11 is ca. 20-fold more active than cocaine and even twice more active than the radioligand 3. Compound 11, like its methyl ester analog (2' aminococaine), exhibited the highest affinity to the DAT. These results, along with previous results, emphasise the importance of a hydrogen-bond donor group at the 2'-position of cocaine and its isopropyl ester analogs to enhance binding affinity to the DAT.

  14. Crystallization and Identification of the Glycosylated Moieties of Two Isoforms of the Main Allergen Hev b 2 and Preliminary X-ray Analysis of Two Polymorphs of Isoform ll

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes-Silva,D.; Mendoza-Hernandez, G.; Stojanoff, V.; Palomares, L.; Zenteno, E.; Torres-Larios, A.; Rodriguez-Romero, A.

    2007-01-01

    Latex from Hevea brasiliensis contains several allergenic proteins that are involved in type I allergy. One of them is Hev b 2, which is a {beta}-1,3-glucanase enzyme that exists in different isoforms with variable glycosylation content. Two glucanase isoforms were isolated from trees of the GV-42 clone by gel filtration, affinity and ion-exchange chromatography. Isoform I had a carbohydrate content of about 20%, with N-linked N-acetyl-glucosamine, N-acetyl-galactosamine, fucose and galactose residues as the main sugars, while isoform II showed 6% carbohydrate content consisting of N-acetyl-glucosamine, fucose, mannose and xylose. Both isoforms were crystallized by the hanging-drop vapor-diffusion method. Isoform I crystals were grown using 0.2 M trisodium citrate dihydrate, 0.1 M Na HEPES pH 7.5 and 20%(v/v) 2-propanol, but these crystals were not appropriate for data collection. Isoform II crystals were obtained under two conditions and X-ray diffraction data were collected from both. In the first condition (0.2 M trisodium citrate, 0.1 M sodium cacodylate pH 6.5, 30% 2-propanol), crystals belonging to the tetragonal space group P4{sub 1} with unit-cell parameters a = b = 150.17, c = 77.41 {angstrom} were obtained. In the second condition [0.2 M ammonium acetate, 0.1 M trisodium citrate dihydrate pH 5.6, 30%(w/v) polyethylene glycol 4000] the isoform II crystals belonged to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 85.08, b = 89.67, c = 101.80 {angstrom}, {beta}= 113.6{sup o}. Preliminary analysis suggests that there are four molecules of isoform II in both asymmetric units.

  15. Crystallization and identification of the glycosylated moieties of two isoforms of the main allergen Hev b 2 and preliminary X-ray analysis of two polymorphs of isoform II

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes-Silva, D. [Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Cuidad Universitaria, Coyoacán, México, DF 04510 (Mexico); Mendoza-Hernández, G. [Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Cuidad Universitaria, Coyoacán, México, DF 04510 (Mexico); Stojanoff, V. [Brookhaven National Laboratory, National Synchrotron Light Source, Upton, NY (United States); Palomares, L. A. [Instituto de Biotecnología, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Cuidad Universitaria, Coyoacán, México, DF 04510 (Mexico); Zenteno, E. [Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Cuidad Universitaria, Coyoacán, México, DF 04510 (Mexico); Torres-Larios, A. [Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Cuidad Universitaria, Coyoacán, México, DF 04510 (Mexico); Rodríguez-Romero, A., E-mail: adela@servidor.unam.mx [Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Cuidad Universitaria, Coyoacán, México, DF 04510 (Mexico)

    2007-09-01

    Crystallization of important glycoenzymes involved in IgE-mediated latex allergy. Latex from Hevea brasiliensis contains several allergenic proteins that are involved in type I allergy. One of them is Hev b 2, which is a β-1,3-glucanase enzyme that exists in different isoforms with variable glycosylation content. Two glucanase isoforms were isolated from trees of the GV-42 clone by gel filtration, affinity and ion-exchange chromatography. Isoform I had a carbohydrate content of about 20%, with N-linked N-acetyl-glucosamine, N-acetyl-galactosamine, fucose and galactose residues as the main sugars, while isoform II showed 6% carbohydrate content constisting of N-acetyl-glucosamine, fucose, mannose and xylose. Both isoforms were crystallized by the hanging-drop vapour-diffusion method. Isoform I crystals were grown using 0.2 M trisodium citrate dihydrate, 0.1 M Na HEPES pH 7.5 and 20%(v/v) 2-propanol, but these crystals were not appropriate for data collection. Isoform II crystals were obtained under two conditions and X-ray diffraction data were collected from both. In the first condition (0.2 M trisodium citrate, 0.1 M sodium cacodylate pH 6.5, 30% 2-propanol), crystals belonging to the tetragonal space group P4{sub 1} with unit-cell parameters a = b = 150.17, c = 77.41 Å were obtained. In the second condition [0.2 M ammonium acetate, 0.1 M trisodium citrate dihydrate pH 5.6, 30%(w/v) polyethylene glycol 4000] the isoform II crystals belonged to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 85.08, b = 89.67, c = 101.80 Å, β = 113.6°. Preliminary analysis suggests that there are four molecules of isoform II in both asymmetric units.

  16. Metabolism of spacecraft cleaning reagents by Mars Odyssey and Phoenix-associated Acinetobacter

    Science.gov (United States)

    Mogul, Rakesh; Barding, Gregory; Baki, Ryan; Perkins, Nicole; Lee, Sooji; Lalla, Sid; Campos, Alexa; Sripong, Kimberly; Madrid, Steve

    2016-07-01

    The metabolomic and proteomic properties that promote microbial survival in spacecraft assembly facilities are important aspects to planetary protection and astrobiology. In this presentation, we will provide molecular and biological evidence that the spacecraft-associated Acinetobacter metabolize/degrade spacecraft cleaning reagents such as ethanol, 2-propanol, and Kleenol-30. Gas chromatography-mass spectrometry (GC-MS) studies on A. radioresistens 50v1 (Mars Odyssey) show that the metabolome is dependent upon growth conditions and that ^{13}C-labeled ethanol is incorporated into metabolites such as TCA/glyoxylate cycle intermediates, amino acids, monosaccharides, and disaccharides (e.g., trehalose). In fact, plate count assays show that ethanol is a sole carbon source under minimal conditions for several Mars Phoenix and Odyssey-associated Acinetobacter strains, which may explain why the Acinetobacter are among the most abundant genera found in spacecraft assembly facilities. Biochemical analyses support the enzymatic oxidation of ethanol and 2-propanol by a membrane-bound and NAD+/PQQ-dependent alcohol dehydrogenase, with current kinetic data providing similar apparent K _{M} and maximum growth rate values of ˜5 and 8 mM ethanol, respectively. Preliminary GC-MS analysis also suggests that Kleenol-30 is degraded by A. radioresistens 50v1 when grown in ethanol mixtures. Under minimal conditions, A. radioresistens 50v1 (˜10 ^{8} cfu/mL) also displays a remarkable oxidative extremotolerance (˜2-log reduction in 10 mM hydrogen peroxide), which suggests crucial roles for metabolites associated with oxidative stress (e.g., trehalose) and the observed appreciable catalase specific activities. In conclusion, these results provide key insights into the survival strategies of spacecraft-associated Acinetobacter and emphasize the importance of characterizing the carbon metabolism of forward contaminants.

  17. Alpha-helical, but not beta-sheet, propensity of proline is determined by peptide environment.

    Science.gov (United States)

    Li, S C; Goto, N K; Williams, K A; Deber, C M

    1996-06-25

    Proline is established as a potent breaker of both alpha-helical and beta-sheet structures in soluble (globular) proteins. Thus, the frequent occurrence of the Pro residue in the putative transmembrane helices of integral membrane proteins, particularly transport proteins, presents a structural dilemma. We propose that this phenomenon results from the fact that the structural propensity of a given amino acid may be altered to conform to changes imposed by molecular environment. To test this hypothesis on proline, we synthesized model peptides of generic sequence H2N-(Ser-LyS)2-Ala- Leu-Z-Ala-Leu-Z-Trp-Ala-Leu-Z-(Lys-Ser)3-OH (Z = Ala and/or Pro). Peptide conformations were analyzed by circular dichroism spectroscopy in aqueous buffer, SDS, lysophosphatidylglycerol micelles, and organic solvents (methanol, trifluoroethanol, and 2-propanol). The helical propensity of Pro was found to be greatly enhanced in the membrane-mimetic environments of both lipid micelles and organic solvents. Proline was found to stabilize the alpha-helical conformation relative to Ala at elevated temperatures in 2-propanol, an observation that argues against the doctrine that Pro is the most potent alpha-helix breaker as established in aqueous media. Parallel studies in deoxycholate micelles of the temperature-induced conformational transitions of the single-spanning membrane bacteriophage IKe major coat protein, in which the Pro-containing wild type was compared with Pro30 --> Ala mutant, Pro was found to protect the helix, but disrupt the beta-sheet structure as effectively as it does to model peptides in water. The intrinsic capacity of Pro to disrupt beta-sheets was further reflected in a survey of porins where Pro was found to be selectively excluded from the core of membrane-spanning beta-sheet barrels. The overall data provide a rationale for predicting and understanding the structural consequences when Pro occurs in the context of a membrane.

  18. A survey of phthalate esters in consumer cosmetic products.

    Science.gov (United States)

    Hubinger, Jean C

    2010-01-01

    Certain phthalate esters have been shown to cause reproductive toxicity in animal models. For this reason, the FDA has been monitoring the use of phthalate esters in cosmetics. In this study, the U.S. Food and Drug Administration (FDA) conducted a limited survey of 84 adult-use and baby-care cosmetic products for the presence of five phthalate esters: dimethyl phthalate (DMP), diethyl phthalate (DEP), benzylbutyl phthalate (BBP), dibutyl phthalate (DBP), and diethylhexyl phthalate (DEHP) (Figure 1). The analytes were extracted from a cosmetic product/Celite mixture with hexane, and the extract was then analyzed using reversed-phase high-performance chromatography (HPLC) on an instrument equipped with an ultraviolet radiation (UV) detector set at 230 nm. The analytes were separated on a Partisil octadecylsilane (ODS)-3 column (250 mm × 4.6 mm I.D., 5μm). The mobile phase consisted of a mixture of 50% water, 34% acetonitrile, 13% 2-propanol, and 3% methanol that was changed linearly (35 minutes) to 15% water, 55% acetonitrile, 25% 2-propanol, and 5% methanol and held for an additional ten minutes. Spiked recoveries in antiperspirant and nail color ranged from 88% to 104%. Thirty-one of the 60 adult-use cosmetic products were found to contain at least one phthalate ester. Twenty products contained DEP and 11 nail products contained DBP. Concentrations of DBP ranged from 123 μg/g to 62,607 μg/g. Concentrations of DEP ranged from 80 μg/g to 36,006 μg/g. Five of the 24 baby-care products contained DEP at concentrations ranging from 10 μg/g to 274 μg/g.

  19. Enhancement of the electrical characteristics of MOS capacitors by reducing the organic content of H{sub 2}O-diluted Spin-On-Glass based oxides

    Energy Technology Data Exchange (ETDEWEB)

    Molina, Joel, E-mail: jmolina@inaoep.mx [National Institute of Astrophysics, Optics and Electronics, Electronics Department, Luis Enrique Erro 1, PO BOX 51 and 216, Tonantzintla, Puebla 72000 (Mexico); Munoz, Ana; Torres, Alfonso; Landa, Mauro; Alarcon, Pablo; Escobar, Manuel [National Institute of Astrophysics, Optics and Electronics, Electronics Department, Luis Enrique Erro 1, PO BOX 51 and 216, Tonantzintla, Puebla 72000 (Mexico)

    2011-10-25

    In this work, the physical, chemical and electrical properties of Metal-Oxide-Semiconductor (MOS) capacitors with Spin-On-Glass (SOG)-based thin films as gate dielectric have been investigated. Experiments of SOG diluted with two different solvents (2-propanol and deionized water) were done in order to reduce the viscosity of the SOG solution so that thinner films (down to {approx}20 nm) could be obtained and their general characteristics compared. Thin films of SOG were deposited on silicon by the sol-gel technique and they were thermally annealed using conventional oxidation furnace and Rapid Thermal Processing (RTP) systems within N{sub 2} ambient after deposition. SOG dilution using non-organic solvents like deionized water and further annealing (at relatively high temperatures {>=}450 deg. C) are important processes intended to reduce the organic content of the films. Fourier-Transform Infrared (FTIR) Spectroscopy results have shown that water-diluted SOG films have a significant reduction in their organic content after increasing annealing temperature and/or dilution percentage when compared to those of undiluted SOG films. Both current-voltage (I-V) and capacitance-voltage (C-V) measurements show better electrical characteristics for SOG-films diluted in deionized water compared to those diluted in 2-propanol (which is an organic solvent). The electrical characteristics of H{sub 2}O-diluted SOG thin films are very similar to those obtained from high quality thermal oxides so that their application as gate dielectrics in MOS devices is promising. Finally, it has been demonstrated that by reducing the organic content of SOG-based thin films, it is possible to obtain MOS devices with better electrical properties.

  20. Synthesis and physico-chemical characterization of CeO{sub 2}/ZrO{sub 2}-SO{sub 4}{sup 2-} mixed oxides

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez E, J. M.; Silva R, R.; Garcia A, R. [Instituto Tecnologico de Ciudad Madero, Div. de Estudios de Posgrado e Investigacion, Juventino Rosas y Jesus Urueta s/n, Col. Los Mangos, 89440 Ciudad Madero, Tamaulipas (Mexico); Garcia S, L. A. [IPN, Centro Interdisciplinario de Investigaciones y de Estudios sobre Medio Ambiente y Desarrollo, 30 de Junio No. 1520, Barrio La Laguna Ticoman, 07340 Mexico D. F. (Mexico); Handy, B. E.; Cardenas G, G. [Universidad Autonoma de San Luis Potosi, CIEP, Facultad de Ciencias Quimicas, Av. Dr. Manuel Nava No. 6, Zona Universitaria, 78210 SLP, San Luis Potosi (Mexico); Cueto H, A. [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Av. San Pablo No. 180, Col. Reynosa Tamaulipas, 02200 Mexico D. F. (Mexico)

    2012-07-01

    Environmentally friendly solid-acid catalysts CeO{sub 2}/ZrO{sub 2}-SO{sub 4}{sup 2-} were prepared by the sol gel method varying CeO{sub 2} content (10, 20 and 30 wt %) and using sulfation in situ, maintaining the sulfate ions amount present in the materials at 20 wt %. ZrO{sub 2} and ZrO{sub 2}-SO{sub 4}{sup 2-} were also prepared for comparison proposes using the same synthesis method. The materials were characterized by X-ray diffraction, nitrogen physisorption, potentiometric titration with n-butylamine, decomposition of 2-propanol and n-pentane isomerization. The specific surface area of ZrO{sub 2}-SO{sub 4}{sup 2-} was high (160 m{sup 2}/g) compared with the unmodified ZrO{sub 2} (80 m{sup 2}/g), however this area decreased with increasing the CeO{sub 2} content (37-100 m{sup 2}/g). There was no significant effect of CeO{sub 2} on the tetragonal structure of ZrO{sub 2}-SO{sub 4}{sup 2-}. The variation of acid sites amount runs parallel to the change of specific surface area. The acid sites amount decreased with increasing cerium oxide content. The decomposition of 2-propanol results fundamentally in the formation of dehydration products such as propylene and diisopropyl ether, both involving acid sites. In addition, a good performance during the n-pentane isomerization was observed for these materials. The selectivity towards isopentane reaches 84% when the Pt/CeO{sub 2}/ZrO{sub 2}-SO{sub 4}{sup 2-} catalyst with the highest CeO{sub 2} content was used. (Author)

  1. Inactivation of murine norovirus by chemical biocides on stainless steel

    Directory of Open Access Journals (Sweden)

    Steinmann Jörg

    2009-07-01

    Full Text Available Abstract Background Human norovirus (NoV causes more than 80% of nonbacterial gastroenteritis in Europe and the United States. NoV transmission via contaminated surfaces may be significant for the spread of viruses. Therefore, measures for prevention and control, such as surface disinfection, are necessary to interrupt the dissemination of human NoV. Murine norovirus (MNV as a surrogate for human NoV was used to study the efficacy of active ingredients of chemical disinfectants for virus inactivation on inanimate surfaces. Methods The inactivating properties of different chemical biocides were tested in a quantitative carrier test with stainless steel discs without mechanical action. Vacuum-dried MNV was exposed to different concentrations of alcohols, peracetic acid (PAA or glutaraldehyde (GDA for 5 minutes exposure time. Detection of residual virus was determined by endpoint-titration on RAW 264.7 cells. Results PAA [1000 ppm], GDA [2500 ppm], ethanol [50% (v/v] and 1-propanol [30% (v/v] were able to inactivate MNV under clean conditions (0.03% BSA on the carriers by ≥ 4 log10 within 5 minutes exposure time, whereas 2-propanol showed a reduced effectiveness even at 60% (v/v. Furthermore, there were no significant differences in virus reduction whatever interfering substances were used. When testing with ethanol, 1- and 2-propanol, results under clean conditions were nearly the same as in the presence of dirty conditions (0.3% BSA plus 0.3% erythrocytes. Conclusion Products based upon PAA, GDA, ethanol and 1-propanol should be used for NoV inactivation on inanimate surfaces. Our data provide valuable information for the development of strategies to control NoV transmission via surfaces.

  2. Protonation of Alcohols in Sulfuric Acid Solutions at UT/LS Conditions

    Science.gov (United States)

    Michelsen, R. R.; Vernier, K.; Axson, J.; Morley, D.

    2007-12-01

    The protonation of several small alcohols (ethanol, 2-propanol, and 1-butanol) in cold sulfuric acid aqueous solutions was measured using variable temperature 13C nuclear magnetic resonance (NMR) spectroscopy. The acidity of the sulfuric acid + deuterium oxide solutions ranged from 43 to 81 weight percent (wt %) H2SO4. The pKBH+ values, which are a measure of the acidity of each alcohol, range from -2.0 for butanol at room temperature to -2.2 for ethanol at -20°C. The protonation enthalpies of the three alcohols over the temperature range of 22°C to -35°C were found to be small and negative, ranging from -1.8 kJ mol-1 for 2-propanol to -2.3 kJ mol-1 for ethanol. A small, negative protonation enthalpy means that the degree of protonation of the alcohol slightly decreases as temperature decreases. The pKBH+values and protonation enthalpies are used to predict the form of dissolved alcohols in sulfate aerosols. For typical upper troposphere/lower stratosphere (UT/LS) conditions (40-70 wt % H2SO4 and 220 K), all three alcohols increase from approximately 10% protonated in 40 wt % H2SO4 to over 60% protonated in 70 wt % H2SO4. The percent of protonated alcohol depends more strongly on m*, the slope factor of the excess acidity treatment, than on pKBH+ values. This relationship may reflect solvation effects. The treatment of strongly acidic, non-ideal solutions as applied to organic solutes in sulfate aerosol particles will be discussed.

  3. Catabolism of methyl ter-butyl ether (MTBE): characterization of the enzymes of Mycobacterium austroafricanum IFP 2012 involved in MTBE degradation; Catabolisme du methyl tert-butyl ether (MTBE): caracterisation des enzymes impliquees dans la degradation du MTBE chez Mycobacterium austroafricanum IFP 2012

    Energy Technology Data Exchange (ETDEWEB)

    Lopes Ferreira, N.

    2005-11-15

    Methyl tert-butyl ether (MTBE) is added to gasoline to meet the octane index requirement. its solubility in water and its poor biodegradability made the use of MTBE a great environmental concern, particularly regarding aquifers. We previously isolated M austroafricanum IFP 2012 able to use MTBE as a sole source of carbon and energy and the MTBE pathway was partially characterized. In the present study, which aimed at isolating the genes involved in MTBE biodegradation in order to use them for estimation of MTBE biodegradation capacities in contaminated environment, we isolated a new M. austroafricanum strain, IFP 2015. A new degradation intermediate, the 2-methyl 1,2-propane-diol (2-M1,2-PD), the product of tert-butanol (TBA) oxidation, was identified. We also determined the enzymes induced during growth of M. austroafricanum IFP 2012 on MTBF. Then, using the tools of protein analysis and of molecular biology, we isolated and cloned the mpd genes cluster in the plasmid pCL4D. Heterologous expression of the recombinant plasmid in M smegmatis tmc2 155, showed the involvement of an 2-M1,2-PD dehydrogenase (MpdB) and a hydroxy-iso-butyr-aldehyde dehydrogenase (MpdC), encoded by mpdB and mpdC, respectively. Both enzymes were responsible for the conversion of 2-M 1,2-PD to hydroxy-isobutyric acid (HIBA). A further survey of different M austroafricanum strains, including IFP 2012, IFP 2015 and JOBS (ex-M vaccae) showed the link between the ability to grow on C{sub 2} to C{sub 16} n-alkanes and the MTBE and TBA degradation capacities. The alkB gene was partially sequenced in all these strains. Expression of alkB was demonstrated in M. austroafricanum IFP 2012 after growth on propane, hexane, hexadecane and TBA. Finally, we identified 2-propanol as the intermediate of HIBA degradation. The gene encoding the 2-propanol:p-N,N'-dimethyl-4-nitroso-aniline (NDMA) oxidoreductase was detected M austroafricanum IFP 2012. (author)

  4. Selective microwave sensors exploiting the interaction of analytes with trap states in TiO2 nanotube arrays

    Science.gov (United States)

    Zarifi, M. H.; Farsinezhad, S.; Abdolrazzaghi, M.; Daneshmand, M.; Shankar, K.

    2016-03-01

    Sensing of molecular analytes by probing the effects of their interaction with microwaves is emerging as a cheap, compact, label-free and highly sensitive detection and quantification technique. Microstrip ring-type resonators are particularly favored for this purpose due to their planar sensing geometry, electromagnetic field enhancements in the coupling gap and compatibility with established printed circuit board manufacturing. However, the lack of selectivity in what is essentially a permittivity-sensing method is an impediment to wider adoption and implementation of this sensing platform. By placing a polycrystalline anatase-phase TiO2 nanotube membrane in the coupling gap of a microwave resonator, we engineer selectivity for the detection and differentiation of methanol, ethanol and 2-propanol. The scavenging of reactive trapped holes by aliphatic alcohols adsorbed on TiO2 is responsible for the alcohol-specific detection while the different short chain alcohols are distinguished on the basis of differences in their microwave response. Electrodeless microwave sensors which allow spectral and time-dependent monitoring of the resonance frequency and quality factor provide a wealth of information in comparison with electrode-based resistive sensors for the detection of volatile organic compounds. A high dynamic range (400 ppm-10 000 ppm) is demonstrated for methanol detection.Sensing of molecular analytes by probing the effects of their interaction with microwaves is emerging as a cheap, compact, label-free and highly sensitive detection and quantification technique. Microstrip ring-type resonators are particularly favored for this purpose due to their planar sensing geometry, electromagnetic field enhancements in the coupling gap and compatibility with established printed circuit board manufacturing. However, the lack of selectivity in what is essentially a permittivity-sensing method is an impediment to wider adoption and implementation of this sensing platform

  5. Soporte de Nuevas Películas de TiO2 y TiO2/SiO2 sobre Gránulos de Poliéster para Aplicación en Fotocatálisis Support of New TiO2 and TiO2/SiO2 Films on Polyester Granules for Photocatalytic Applications

    Directory of Open Access Journals (Sweden)

    Juan M Marín

    2008-01-01

    Full Text Available Películas de TiO2 o TiO2/SiO2 fueron soportadas sobre gránulos de poliéster usando mecanismos de difusión y posterior tratamiento térmico a 100ºC. Se emplearon dos clases de geles. El primero fue preparado usando diferentes cantidades de TiO2, cloruro de metileno y silicona líquida. El segundo fue obtenido por medio del método sol-gel, empleado para producir una matriz de sílice a partir de la hidrólisis el tetraetilo ortosilicato, en un medio orgánico de 2-propanol, en el cual se dispersó el fotocatalizador. Los precursores de cada sistema fueron agregados en diferentes relaciones para determinar su influencia en la estabilidad, propiedades y fotoactividad de las películas. La actividad fotocatalítica fue evaluada en la fotodegradación de metanol en fase gaseosa. Los resultados muestran la producción de materiales con alta resistencia, funcionalidad y actividad así como una fuerte relación entre la actividad fotocatalítica con las propiedades fisicoquímicas.Films of TiO2 and of TiO2/SiO2 were supported on polyester granules using a diffusion mechanism and a posterior thermal treatment to 100ºC. Two kinds of gels were used. The first one was prepared using different amounts of TiO2, methylene chloride and liquid silicone. The second one used the sol-gel method to produce a silica matrix by adding tetraethyl orthosilicate, water and 2- propanol. After that the photocatalyst was dispersed in the gel. The precursors of each system were added in different amounts to determine their influence in the stability, properties and photoactivity of the films. The photocatalytic activity was tested in the methanol photodegradation in gas phase. The results show the production of materials with high resistance, functionality and activity as well as a strong dependence between the photocatalityc activity and efficiency with the physicochemical properties of the films.

  6. Simultaneous derivatization and ultrasound-assisted dispersive liquid-liquid microextraction of chloropropanols in soy milk and other aqueous matrices combined with gas-chromatography-mass spectrometry.

    Science.gov (United States)

    Carro, A M; González, P; Lorenzo, R A

    2013-12-06

    A novel approach involving ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) and derivatization combined with gas chromatography-mass spectrometry was developed for the determination of chloropropanols in water and beverages. UA-DLLME was optimized as less solvent-consuming and cost-effective extraction method for water, fruit juice, milk and soy milk samples. The effect of parameters such as the type and volume of extraction solvent, the type and volume of dispersive solvent, amount of derivatization agent, temperature, pH of sample and ionic strength was investigated and optimized for each specimen, using experimental designs. By adding acetonitrile as dispersive solvent, N-heptafluorobutyrylimizadole (HFBI) as derivatization agent and chloroform as extraction solvent, the extraction-derivatization and preconcentration were simultaneously performed. The analytical concentration range was investigated in detail for each analyte in the different samples, obtaining linearity with R(2) ranging between 0.9990 and 0.9999. The method detection limits were in the range of 0.2-1.8μgL(-1) (water), 0.5-15μgL(-1) (fruit juices) and 0.9-3.6μgkg(-1) (milk) and 0.1-1.0μgkg(-1) (soy milk). The method was applied to the analysis of a variety of specimens, with recoveries of 98-101% from water, 97-102% from juices, 99-103% from milk and 97-105% from soy beverage. The relative standard deviation (precision, n=6) varied between 1.3 and 4.9%RSD in water, 2.3 and 5.8%RSD in juices, 1.0 and 5.7%RSD in milk and 3.9 and 9.3%RSD in soy milk. The proposed method was applied to analysis of twenty-eight samples. 1,3-Dichloro-2-propanol was found in an influent water sample from urban wastewater treatment plant (WWTP) (2.1±0.04mgL(-1)) but no chloropropanols were found in the corresponding effluent water sample. This result suggests that the purification system used in the WWTP has been effective for this compound. Moreover, the results revealed the presence of 3

  7. Preparation of two ester-containing Gemini quaternary ammonium softener and its properties%双酯基Gemini季铵盐柔软剂的制备及性能

    Institute of Scientific and Technical Information of China (English)

    娄平均; 朱红军; 丁徽; 牛华

    2011-01-01

    A di-ester Gemini quaternary ammonium softener( DEGOS) is prepared with dimethyl stearic acid ethyl tertiary amine and 1,3-dichloro-2-propanol as raw materials. The optimum synthesis conditions ara determined via orthogonal experiments as follows∶reaction at 80 ℃ for 12 hours with n( 1 , 3-dichloro-2-propanol) ∶ n ( dimethyl stearic acid ethyl tertiary amine) = 1 ∶ 2.1and ethanol of 40% , and the yield reaches 89.3%. The product is characterized by FTIR, elemental analysis and 1H-NMR, and its application properties are studied. The results show that the product features good surface activity with surface tension of 35.9 mN/m, critical micelle concentration of 0.039 mmol/L and Krafft point of - 3.41 ℃, good softening property similar to that of commercial softener D1821, and good rewetting property and biodegradability, as well as low influence on whiteness of the fabric.%以二甲基硬脂酸乙酯基叔胺和l,3-二氯-2-丙醇为原料,合成了一种双酯基Gemini季铵盐织物柔软剂(DEGQS).通过正交试验考察了反应的影响因素,确定优化工艺条件为:n(1,3-二氯-2-丙醇):n(二甲基硬脂酸乙酯基叔胺)=1:2.1,反应温度80℃,W(乙醇)=40%(占反应物总量的质量分数),反应时间12 h,在该条件下目标产物的收率达到89.3%.通过FTIR、元素分析和1H-NMR对DEGQS进行表征,并研究其应用性能,结果表明,该柔软剂的表面张力35.9 mN/m,临界胶束浓度0.039 mmol/L,Krafft点为-3.41℃,表面活性较好,柔软性能与D1821基本相当,具有优良的再润湿性和生物降解性能,对织物的白度影响较小.

  8. Using a water-immiscible ionic liquid to improve asymmetric reduction of 4-(trimethylsilyl-3-butyn-2-one catalyzed by immobilized Candida parapsilosis CCTCC M203011 cells

    Directory of Open Access Journals (Sweden)

    Smith Thomas J

    2009-10-01

    Full Text Available Abstract Background Whole cells are usually employed for biocatalytic reduction reactions to ensure efficient coenzyme regeneration and to avoid problems with enzyme purification and stability. The efficiency of whole cell-catalyzed bioreduction is frequently restricted by pronounced toxicity of substrate and/or product to the microbial cells and in many instances the use of two-phase reaction systems can solve such problems. Therefore, we developed new, biphasic reaction systems with biocompatible water-immiscible ionic liquids (ILs as alternatives to conventional organic solvents, in order to improve the asymmetric reduction of 4-(trimethylsilyl-3-butyn-2-one (TMSB to (S-4-(trimethylsilyl-3-butyn-2-ol {(S-TMSBOL}, a key intermediate for synthesis of 5-lipoxygenase inhibitors, using immobilized Candida parapsilosis CCTCC M203011 cells as the biocatalyst. Results Various ILs exerted significant but different effects on the bioreduction. Of all the tested water-immiscible ILs, the best results were observed with 1-butyl-3-methylimidazolium hexafluorophosphate (C4MIM·PF6, which exhibited not only good biocompatibility with the cells but also excellent solvent properties for the toxic substrate and product, thus markedly improving the efficiency of the bioreduction and the operational stability of the cells as compared to the IL-free aqueous system. 2-Propanol was shown to be the most suitable co-substrate for coenzyme regeneration, and it was found that the optimum volume ratio of buffer to C4MIM·PF6, substrate concentration, buffer pH, 2-propanol concentration and reaction temperature were 4/1 (v/v, 24 mM, 5.5, 130 mM and 30°C, respectively. Under these optimized conditions, the maximum yield and the product e.e. wer 97.7% and >99%, respectively, which are much higher than the corresponding values previously reported. The efficient whole-cell biocatalytic process was shown to be feasible on a 250-mL scale. Conclusion The whole cell

  9. Efeito da fertilização nitrogenada em videira sobre a formação de alguns compostos volatéis no vinho Effect of vineyard nitrogen fertilization on the formation of some wine volatile coumpounds

    Directory of Open Access Journals (Sweden)

    Lúcia Schuch Boeira

    1995-01-01

    Full Text Available Vitis vinifera cv. Gewürztraminer e Cabemet Sauvignon cultivadas em Santana do Livramento e Garibaldi foram submetidas a diferentes tratamentos nitrogenados realizados durante o período vegetativo de 1992-1993. Após a colheita e esmagamento o mosto obtido foi dividido em quatro lotes e fermentado com diferentes leveduras. As determinações dos compostos voláteis foram realizados através de cromatografia gasosa. Maiores valores de metanol foram encontrados nos vinhos de Cabemet Sauvignon (máximo 225,6mg/l. A fertilização nitrogenada provocou um aumento na concentração (mg/l de propanol-1 (min. 25 -máx. 78,2 e uma diminuição de metil-2 propanol-1 (min. 60,8 - máx. 125,9 e metil-3 + metil-2 butanol-1 (min. 85,8 - máx. 407,8 nos vinhos. Os álcoois superiores apresentaram também diferenças em relação à região, cultivar e levedura utilizada.Vitis vinifera Gewürztraminer (white variety and Cabemet Sauvignon (red growned in Santana do Livramento, RS, and Garibaldi, RS, were added with different nitrogen treatments in the vineyard during me 1992-1993 season. After harvest and crushing, the musts were divided into four lots each one added with a different yeast. The volatiles were analyzed through GC. Maximum amount of methanol was found with the red variety (225.6mg/l. Increasing nitrogen in the soil increased (mg/l propanol-1 (min. 25-max. 78.2 and decreased methyl-2 propanol-1 (min. 60.8-max. 125.9 and methyl-3+methyl-2 butanol-1 (min. 85.8-max. 407.8. The fusel alcohol fraction showed, also, differences between region,grape variety and yeast used.

  10. Chromatographic performance of synthetic polycrystalline diamond as a stationary phase in normal phase high performance liquid chromatography.

    Science.gov (United States)

    Peristyy, Anton; Paull, Brett; Nesterenko, Pavel N

    2015-04-24

    The chromatographic properties of high pressure high temperature synthesised diamond (HPHT) are investigated in normal phase mode of high performance liquid chromatography. Purified nonporous irregular shape particles of average particles size 1.2 μm and specific surface area 5.1 m(2) g(-1) were used for packing 100×4.6 mm ID or 50×4.6 mm ID stainless steel columns. The retention behaviour of several classes of compounds including alkyl benzenes, polyaromatic hydrocarbons (PAH), alkylphenylketones, phenols, aromatic acids and bases were studied using n-hexane-2-propanol mixtures as mobile phase. The results are compared with those observed for microdispersed sintered detonation nanodiamond (MSDN) and porous graphitic carbon (PGC). HPHT diamond revealed distinctive separation selectivity, which is orthogonal to that observed for porous graphitic carbon; while selectivities of HPHT diamond and microdispersed sintered detonation nanodiamonds are similar. Owing to non-porous particle nature, columns packed with high pressure high temperature diamond exhibited excellent mass transfer and produce separations with maximum column efficiency of 128,200 theoretical plates per meter.

  11. Application of the ERAS model to volumetric properties of binary mixtures of banana oil with primary and secondary alcohols (C1-C4) at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Behroozi, Mahboobe [Faculty of Chemistry, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Zarei, Hosseinali, E-mail: zareih@basu.ac.i [Faculty of Chemistry, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of)

    2011-05-15

    The densities of binary mixtures of {l_brace}isoamyl acetate + alcohols (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 2-butanol){r_brace}, including those of pure liquids, over the entire composition range were measured at temperatures (293.15 to 333.15) K and atmospheric pressure by means of a vibrating-tube densimeter. The excess molar volume, V{sub m}{sup E}, thermal expansion coefficients, {alpha}, and their excess values, {alpha}{sup E}, were calculated from density data. The V{sub m}{sup E} values are positive over the entire range of composition and temperature and become more positive with increasing temperature for all of the mixtures except for the (isoamyl acetate + methanol) mixture. The V{sub m}{sup E} values were correlated by Redlich-Kister equation and the extended real associated solution (ERAS) model was used for describing V{sub m}{sup E} values at T = 303.15 K.

  12. Statistical Approach for Optimization of Physiochemical Requirements on Alkaline Protease Production from Bacillus licheniformis NCIM 2042

    Directory of Open Access Journals (Sweden)

    Biswanath Bhunia

    2012-01-01

    Full Text Available The optimization of physiochemical parameters for alkaline protease production using Bacillus licheniformis NCIM 2042 were carried out by Plackett-Burman design and response surface methodology (RSM. The model was validated experimentally and the maximum protease production was found 315.28 U using optimum culture conditions. The protease was purified using ammonium sulphate (60% precipitation technique. The HPLC analysis of dialyzed sample showed that the retention time is 1.84 min with 73.5% purity. This enzyme retained more than 92% of its initial activity after preincubation for 30 min at 37∘C in the presence of 25% v/v DMSO, methanol, ethanol, ACN, 2-propanol, benzene, toluene, and hexane. In addition, partially purified enzyme showed remarkable stability for 60 min at room temperature, in the presence of anionic detergent (Tween-80 and Triton X-100, surfactant (SDS, bleaching agent (sodium perborate and hydrogen peroxide, and anti-redeposition agents (Na2CMC, Na2CO3. Purified enzyme containing 10% w/v PEG 4000 showed better thermal, surfactant, and local detergent stability.

  13. Measurement and modeling of osmotic coefficients of binary mixtures (alcohol + 1,3-dimethylpyridinium methylsulfate) at T = 323.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Elena [Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Calvar, Noelia, E-mail: noecs@uvigo.e [Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Dominguez, Angeles [Advanced Separation Processes Group, Departamento de Ingenieria Quimica, Universidad de Vigo, 36310 Vigo (Spain); Macedo, Eugenia A. [Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)

    2011-06-15

    Research highlights: The osmotic coefficients of binary mixtures (alcohol + ionic liquid) were determined. The measurements were carried out with a vapor pressure osmometer at 323.15 K. The Pitzer-Archer, and the MNRTL models were used to correlate the experimental data. Mean molal activity coefficients and excess Gibbs free energies were calculated. - Abstract: Measurement of osmotic coefficients of binary mixtures containing several primary and secondary alcohols (1-propanol, 2-propanol, 1-butanol, 2-butanol, and 1-pentanol) and the pyridinium-based ionic liquid 1,3-dimethylpyridinium methylsulfate were performed at T = 323.15 K using the vapor pressure osmometry technique, and from experimental data, vapor pressure, and activity coefficients were determined. The extended Pitzer model modified by Archer, and the NRTL model modified by Jaretun and Aly (MNRTL) were used to correlate the experimental osmotic coefficients, obtaining standard deviations lower than 0.017 and 0.054, respectively. From the parameters obtained with the extended Pitzer model modified by Archer, the mean molal activity coefficients and the excess Gibbs free energy for the studied binary mixtures were calculated. The effect of the cation is studied comparing the experimental results with those obtained for the ionic liquid 1,3-dimethylimidazolium methylsulfate.

  14. Photodegradation of estrone enhanced by dissolved organic matter under simulated sunlight

    KAUST Repository

    Caupos, Emilie

    2011-05-01

    In the present work the degradation of estrone (E1) a natural estrogenic hormone has been studied under simulated solar irradiation. The photodegradation of E1 has been investigated in the absence and in the presence of 7.7-8.9 mg L-1 of dissolved organic carbon (DOC), under solar light simulation with irradiance approximating that of the sun. DOC extracts from different origins have been used. Half-lives ranging between 3.9 h and 7.9 h were observed. Results indicated that E1 was photodegraded even in the absence of DOC. The presence of DOC was found to enhance the degradation of E1. Experiments performed with the addition of reactive species scavengers (azide ions and 2-propanol) have shown that these two species play a significant role in the photodegradation. Some experiments have been performed with a DOC previously submitted to solar irradiation. Changes in optical and physico-chemical properties of DOC strongly affect its photoinductive properties, and hence its efficiency on E1 degradation. A part of the study consisted in the investigation of photoproducts structures. Five photoproducts were shown by chromatographic analysis: one arising from direct photolysis and the four others from DOC photoinduced degradation. © 2011 Elsevier Ltd.

  15. Analysis of wax esters by silver-ion high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Vrkoslav, Vladimír; Urbanová, Klára; Háková, Matina; Cvačka, Josef

    2013-08-01

    Wax esters (WEs), esters of long-chain fatty acids and long-chain alcohols, were analysed by Ag-HPLC/APCI-MS/MS. Two ChromSpher Lipids columns connected in series (a total length of 50cm) and hexane-2-propanol-acetonitrile mobile phases were used to achieve good separation of the molecular species. The chromatographic behaviour of WEs was studied under optimised conditions: retention increased with the number of double bonds and with the temperature (15-35°C); retention times were affected by the double-bond position, trans isomers eluted earlier than cis isomers, and the WEs were partially separated depending on the aliphatic-chain length. The WEs provided simple APCI spectra with [M+H](+) ions, the MS/MS spectra showed fragments, which allowed their identification. The method was applied for an analysis of the WE mixtures from jojoba oil and human hair and the results were compared with analogous data from an optimised RP-HPLC system.

  16. Inactivation of Lactobacillus rhamnosus GG by fixation modifies its probiotic properties.

    Science.gov (United States)

    Markowicz, C; Kubiak, P; Grajek, W; Schmidt, M T

    2016-01-01

    Probiotics are microorganisms that have beneficial effects on the host and are safe for oral intake in a suitable dose. However, there are situations in which the administration of living microorganisms poses a risk for immunocompromised host. The objective of this study was to evaluate the influence of several fixation methods on selected biological properties of Lactobacillus rhamnosus GG that are relevant to its probiotic action. Fixation of the bacterial cells with ethanol, 2-propanol, glutaraldehyde, paraformaldehyde, and heat treatment resulted in a significant decrease of alkaline phosphatase, peroxidase, and β-galactosidase activities. Most of the fixation procedures reduced bacterial cell hydrophobicity and increased adhesion capacity. The fixation procedures resulted in a different perception of the bacterial cells by enterocytes, which was shown as changes in gene expression in enterocytes. The results show that some procedures of inactivation allow a fraction of the enzymatic activity to be maintained. The adhesion properties of the bacterial cells were enhanced, but the response of enterocytes to fixed cells was different than to live bacteria. Inactivation allows maintenance and modification of some of the properties of the bacterial cells.

  17. A robust whole-cell biocatalyst that introduces a thermo- and solvent-tolerant lipase into Aspergillus oryzae cells: characterization and application to enzymatic biodiesel production.

    Science.gov (United States)

    Adachi, Daisuke; Koh, FookHee; Hama, Shinji; Ogino, Chiaki; Kondo, Akihiko

    2013-05-10

    To develop a robust whole-cell biocatalyst that works well at moderately high temperature (40-50°C) with organic solvents, a thermostable lipase from Geobacillus thermocatenulatus (BTL2) was introduced into an Aspergillus oryzae whole-cell biocatalyst. The lipase-hydrolytic activity of the immobilized A. oryzae (r-BTL) was highest at 50°C and was maintained even after an incubation of 24-h at 60°C. In addition, r-BTL was highly tolerant to 30% (v/v) organic solvents (dimethyl carbonate, ethanol, methanol, 2-propanol or acetone). The attractive characteristics of r-BTL also worked efficiently on palm oil methanolysis, resulting in a nearly 100% conversion at elevated temperature from 40 to 50°C. Moreover, r-BTL catalyzed methanolysis at a high methanol concentration without a significant loss of lipase activity. In particular, when 2 molar equivalents of methanol were added 2 times, a methyl ester content of more than 90% was achieved; the yield was higher than those of conventional whole-cell biocatalyst and commercial Candida antarctica lipase (Novozym 435). On the basis of the results regarding the excellent lipase characteristics and efficient biodiesel production, the developed whole-cell biocatalyst would be a promising biocatalyst in a broad range of applications including biodiesel production.

  18. Diamond-like carbon films deposited on three-dimensional shape substrate model by liquid electrochemical technique

    Energy Technology Data Exchange (ETDEWEB)

    He, Y.Y. [Institute of Nano-photonics, School of Physics and Materials Engineering, Dalian Nationalities University, 116600 Dalian (China); Zhang, G.F. [School of Materials Science and Engineering, Dalian University of Technology, 116024, Dalian China (China); Zhao, Y.; Liu, D.D. [Institute of Nano-photonics, School of Physics and Materials Engineering, Dalian Nationalities University, 116600 Dalian (China); Cong, Y., E-mail: congyan@ciomp.ac.cn [Institute of Nano-photonics, School of Physics and Materials Engineering, Dalian Nationalities University, 116600 Dalian (China); Buck, V. [Thin Film Technology Group, Faculty of Physics, University Duisburg-Essen and CeNIDE, 47057 Duisburg (Germany)

    2015-09-01

    Diamond-like carbon (DLC) films were deposited on three-dimensional (3D) shape substrate model by electrolysis of 2-propanol solution at low temperature (60 °C). This 3D shape model was composed of a horizontally aligned stainless steel wafer and vertically aligned stainless steel rods. Morphology and microstructure of the films were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy, respectively. The results suggested there were only differences in film uniformity and thickness for two kinds of samples. The hydrogenated amorphous carbon films deposited on horizontally aligned substrate were smooth and homogeneous. And the film thickness of DLC films gained on the vertical substrates decreased along vertical direction. It is believed that bubble formation could enhance nucleation on the wetted capillary area. This experiment shows that deposition of DLC films by liquid phase deposition on 3D shape conductive substrates is possible. - Highlights: • DLC film is expected to be deposited on complex surface/shape substrate. • DLC film is deposited on 3D shape substrate by liquid electrochemical method. • Horizontal substrate is covered by smooth and homogeneous DLC films. • Film thickness decreases along vertical direction due to boiling effect.

  19. Liquid exfoliated pristine WS2 nanosheets for ultrasensitive and highly stable chemiresistive humidity sensors

    Science.gov (United States)

    Jha, Ravindra Kumar; Guha, Prasanta Kumar

    2016-11-01

    WS2 nanosheets have been synthesized by ultrasonication in a binary mixture of acetone and 2-propanol, with a volume ratio of 80:20. Hansen solubility parameters were taken into consideration as part of the process. These nanosheets have been characterized by electron microscopy, atomic force microscopy, and x-ray diffraction, along with spectroscopy such as ultraviolet-visible spectroscopy, Raman spectroscopy, and x-ray photoelectron spectroscopy. The nanosheets were further used as a sensing material to fabricate a humidity sensor on interdigitated aluminum electrodes, realized over Si/SiO2 substrate using a conventional photolithography technique. The response for our sensor varied from 11.9 for 40% RH to as high as 37.5 for 80% RH. Response and recovery time were found to be 13 ± 2 s and 17 ± 2 s respectively. The suspended nanosheets were also treated with UV light in a nitrogen environment. The response for UV treated nanosheets shows better linearity, however its response decreases in the presence of humidity. This is due to a decrease in oxygen content of the UV treated sample. Furthermore, the effect of sonication time has been investigated, and it was found that samples with 10 h sonication are better than others due to their high surface-to-volume ratio. The repeatability and stability of the sensor have been investigated and found to be excellent. The hysteresis in the sensors was also explored. The mechanism of humidity sensing has been discussed in detail.

  20. The radiation chemistry of Hoechst 33258 and its potential radiosensitizing analogues

    Energy Technology Data Exchange (ETDEWEB)

    Nel, P. [Melbourne Univ., Parkville, VIC (Australia). Dept. of Chemistry]|[Peter McCallum Cancer Institute, Reserach Division, East Melbourne, VIC (Australia); Cooper, R. [Melbourne Univ., Parkville, VIC (Australia). Dept. of Chemistry; Martin, R.F. [Peter McCallum Cancer Institute, East Melbourne, VIC, (Australia)

    1996-12-31

    Collaborative research between Peter MacCallum Cancer Institute and The University of Melbourne is aimed to investigate the photochemistry and radiation chemistry of the halogenated analogues m-I Hoechst and o-I Hoechst (which are being developed as potential radiosensitizers). Studies were conducted on Hoechst 33258, phenyl Hoechst, m-I Hoechst and o-I Hoechst. The chemical interaction between the Hoechst analogues and the radiolysis products of water (the hydroxy radical and the aqueous electron) were investigated by saturating aqueous solutions with nitrogen or nitrous oxide (an electron scavenger) and using 2-propanol as a hydroxy radical scavenger. Hoechst 33258 was investigated at pH 5 and pH 9. Transient absorption spectra of micromolar solutions saturated with nitrogen or nitrous oxide suggest the formation of hydroxyl radical adduct(s). The rate of formation of these transient spectra was observed to be dependent on the concentration of Hoechst 33258. Phenyl Hoechst, m- I Hoechst and o-I Hoechst were studied at pH 5. Spectra again suggest the formation of hydroxy radical adducts and that both m-I Hoechst and o-I Hoechst react with aqueous electrons.

  1. Large Mesopore Generation in an Amorphous Silica-Alumina by Controlling the Pore Size with the Gel Skeletal Reinforcement and Its Application to Catalytic Cracking

    Directory of Open Access Journals (Sweden)

    Hiroyuki Nasu

    2012-09-01

    Full Text Available Tetraethoxy orthosilicate (TEOS was used not only as a precursor of silica, but also as an agent which reinforces the skeleton of silica-gel to prepare an aerogel and resultant silica and silica-alumina with large pore size and pore volume. In this gel skeletal reinforcement, the strength of silica aerogel skeleton was enhanced by aging with TEOS/2-propanol mixed solution to prevent the shrink of the pores. When silica aerogel was reinforced by TEOS solution, the pore diameter and pore volume of calcined silica could be controlled by the amount of TEOS solution and reached 30 nm and 3.1 cm3/g. The results from N2 adsorption measurement indicated that most of pores for this silica consisted of mesopores. Silica-alumina was prepared by the impregnation of an aluminum tri-sec-butoxide/2-butanol solution with obtained silica. Mixed catalysts were prepared by the combination of β-zeolite (26 wt% and prepared silica-aluminas with large mesopore (58 wt% and subsequently the effects of their pore sizes on the catalytic activity and the product selectivity were investigated in catalytic cracking of n-dodecane at 500 °C. The mixed catalysts exhibited not only comparable activity to that for single zeolite, but also unique selectivity where larger amounts of branched products were formed.

  2. Oxygen Storage Capacity and Oxygen Mobility of Co-Mn-Mg-Al Mixed Oxides and Their Relation in the VOC Oxidation Reaction

    Directory of Open Access Journals (Sweden)

    María Haidy Castaño

    2015-05-01

    Full Text Available Co-Mn-Mg-Al oxides were synthesized using auto-combustion and co-precipitation techniques. Constant ratios were maintained with (Co + Mn + Mg/Al equal to 3.0, (Co + Mn/Mg equal to 1.0 and Co/Mn equal to 0.5. The chemical and structural composition, redox properties, oxygen storage capacity and oxygen mobility were analyzed using X-ray fluorescence (XRF, X-ray diffraction (XRD, Raman spectroscopy, scanning electron microscopy (SEM, temperature-programmed reduction of hydrogen (H2-TPR, oxygen storage capacity (OSC, oxygen storage complete capacity (OSCC and isotopic exchange, respectively. The catalytic behavior of the oxides was evaluated in the total oxidation of a mixture of 250 ppm toluene and 250 ppm 2-propanol. The synthesis methodology affected the crystallite size, redox properties, OSC and oxide oxygen mobility, which determined the catalytic behavior. The co-precipitation method got the most active oxide in the oxidation of the volatile organic compound (VOC mixture because of the improved mobility of oxygen and ability to favor redox processes in the material structure.

  3. Solvent effects on the AIBN forced degradation of cumene: Implications for forced degradation practices.

    Science.gov (United States)

    Nelson, Eric D; Thompson, Gina M; Yao, Ye; Flanagan, Holly M; Harmon, Paul A

    2009-03-01

    Solvent effects on the AIBN and ACVA forced degradation of cumene are explored. The degradant formation rates of the three cumene oxidative degradants, cumene hydroperoxide, acetophenone, and 2-phenyl-2-propanol are reported. The relative abundance and ratios of these three degradants provide insight into the fate of the peroxy radical oxidants generated by the forced stress system, and suggest that alkoxy radicals are actually a significant source of the observed reactivity. The presence of even 1% methanol in the forced stress solvent significantly quenches this alkoxy radical reactivity, dramatically reducing the overall degradation rate and leaving cumene hydroperoxide as the major product of the oxidation reaction. The origin of this significant solvent effect on the oxidation product distribution is shown to be related to the preferential H-atom abstraction from methanol and its trace impurities by any alkoxy radicals present in the reaction solution. The implications for these observations are explored with the intent of producing more predictive oxidative forced stress experiments.

  4. Cumene oxidation by cis-[RuIV(bpy)2(py)(O)]2+, revisited.

    Science.gov (United States)

    Bryant, Jasmine R; Matsuo, Takashi; Mayer, James M

    2004-02-23

    cis-[RuIV(bpy)2(py)(O)]2+ oxidizes cumene (2-phenylpropane) in acetonitrile solution primarily to cumyl alcohol (2-phenyl-2-propanol), alpha-methylstyrene, and acetophenone. Contrary to a prior report, the rate of the reaction is not accelerated by added nucleophiles. There is thus no evidence for the hydride transfer mechanism originally proposed. Instead, the results are consistent with a mechanism of initial hydrogen atom transfer from cumene to the ruthenium oxo group. This is indicated by the correlation of rate with C-H bond strength and by the various products observed. The formation of acetophenone, with one carbon less than cumene, is suggested to occur via a multistep pathway involving decarbonylation of the acyl radical from 2-phenylpropanal. An alternative mechanism involving beta-scission of cumyloxyl radical is deemed unlikely because of the difficulty of generating alkoxyl radicals under anaerobic conditions and the lack of rearranged products in the oxidation of triphenylmethane by cis-[RuIV(bpy)2(py)(O)]2+.

  5. Natural organic matter and sunlight accelerate the degradation of 17ss-estradiol in water

    Energy Technology Data Exchange (ETDEWEB)

    Leech, Dina M. [Institute of Marine Sciences, University of North Carolina at Chapel Hill, 3431 Arendell Street, Morehead City, NC 28557 (United States)], E-mail: dmleech@email.unc.edu; Snyder, Matthew T.; Wetzel, Robert G. [Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States)

    2009-03-01

    Nanomolar concentrations of steroid hormones such as 17{beta}-estradiol can influence the reproductive development and sex ratios of invertebrate and vertebrate populations. Thus their release into surface and ground waters from wastewater facilities and agricultural applications of animal waste is of environmental concern. Many of these compounds are chromophoric and susceptible to photolytic degradation. High intensity UV-C radiation has been demonstrated to degrade some of these compounds in engineered systems. However, the degradation efficacy of natural solar radiation in shallow fresh waters is less understood. Here photolytic experiments with 17{beta}-estradiol demonstrated modest photodegradation ({approx} 26%) when exposed to simulated sunlight between 290 and 720 nm. Photodegradation significantly increased ({approx} 40-50%) in the presence of 2.0-15.0 mg/l of dissolved organic carbon (DOC) derived from humic acids of the Suwannee River, GA. However, rates of photodegradation reached a threshold at approximately 5.0 mg/l DOC. Observed suppression of photolysis in the presence of a radical inhibitor (i.e. 2-propanol) indicated that a significant proportion of the degradation was due to radicals formed from the photolysis of DOC. Although photodegradation was greatest in full sunlight containing UV-B (290-320 nm), degradation was also detected with UV-A (320-400 nm) and visible light (400-720 nm) alone.

  6. Calcium phosphate/microgel composites for 3D powderbed printing of ceramic materials.

    Science.gov (United States)

    Birkholz, Mandy-Nicole; Agrawal, Garima; Bergmann, Christian; Schröder, Ricarda; Lechner, Sebastian J; Pich, Andrij; Fischer, Horst

    2016-06-01

    Composites of microgels and calcium phosphates are promising as drug delivery systems and basic components for bone substitute implants. In this study, we synthesized novel composite materials consisting of pure β-tricalcium phosphate and stimuli-responsive poly(N-vinylcaprolactam-co-acetoacetoxyethyl methacrylate-co-vinylimidazole) microgels. The chemical composition, thermal properties and morphology for obtained composites were extensively characterized by Fourier transform infrared, X-ray photoelectron spectroscopy, IGAsorp moisture sorption analyzer, thermogravimetric analysis, granulometric analysis, ESEM, energy dispersive X-ray spectroscopy and TEM. Mechanical properties of the composites were evaluated by ball-on-three-balls test to determine the biaxial strength. Furthermore, initial 3D powderbed-based printing tests were conducted with spray-dried composites and diluted 2-propanol as a binder to evaluate a new binding concept for β-tricalcium phosphate-based granulates. The printed ceramic bodies were characterized before and after a sintering step by ESEM. The hypothesis that the microgels act as polymer adhesive agents by efficient chemical interactions with the β-tricalcium phosphate particles was confirmed. The obtained composites can be used for the development of new scaffolds.

  7. Asymmetric transfer hydrogenation of prochiral ketone catalyzed over Fe-CS/SBA-15 catalyst

    Institute of Scientific and Technical Information of China (English)

    XUE Ping; WU Tao

    2007-01-01

    A heterogeneous chiral catalyst Fe(Ⅲ)-CS (chitosan)complex/mesoporous molecular sieve SBA-15 (Santa Barbara Amorphous) was prepared.The asymmetric transfer hydrogenations of prochiral acetophenone and 4-methyl-2-pentanone to corresponding chiral alcohols were carried out on Fe-CS/SBA-15 at atmosphere pressure using 2-propanol as hydrogen donor.Effects of Fe content in catalyst,reaction temperature,reaction time and promoter KOH concentration on the conversion of substrates and enantioselectivity were investigated.Fe-CS/SBA-15 with 2.2%mass fraction Fe exhibits considerable enantioselectivity and catalytic activity for the asymmetric transfer hydrogenations of aromatic ketone and aliphatic ketone.Under optimal reaction conditions:KOH concentration 0.03 mol/L,reaction temperature 70℃ and reaction time 4 h,enantiomer excess(ee)of (R)-1-phenylethanol and conversion of acetophenone can reach 87.4%and 27.7%,respectively.Under the above KOH concentration and reaction temperature and reaction time of 8 h,the ee of(R)-4-methyl-2-pentanol and conversion 4-methyl-2-pentanone amounted to 50.2%and 25.5%,respectively.

  8. Partial Characterization of the Proteolytic Properties of an Enzymatic Extract From "Aguama" Bromelia pinguin L. Fruit Grown in Mexico.

    Science.gov (United States)

    Moreno-Hernández, Jesús Martín; Hernández-Mancillas, Xitlalli Desideria; Navarrete, Evelia Lorena Coss; Mazorra-Manzano, Miguel Ángel; Osuna-Ruiz, Idalia; Rodríguez-Tirado, Víctor Alfonso; Salazar-Leyva, Jesús Aarón

    2016-11-09

    Plant proteases are capable of performing several functions in biological systems, and their use is attractive for biotechnological process due to their interesting catalytic properties. Bromelia pinguin (aguama) is a wild abundant natural resource in several regions of Central America and the Caribbean Islands but is underutilized. Their fruits are rich in proteases with properties that are still unknown, but they represent an attractive source of enzymes for biotechnological applications. Thus, the proteolytic activity in enzymatic crude extracts (CEs) from wild B. pinguin fruits was partially characterized. Enzymes in CEs showed high proteolytic activity at acid (pH 2.0-4.0) and neutral alkaline (pH 7.0-9.0) conditions, indicating that different types of active proteases are present. Proteolytic activity inhibition by the use of specific protease inhibitors indicated that aspartic, cysteine, and serine proteases are the main types of proteases present in CEs. Activity at pH 3.0 was stable in a broad range of temperatures (25-50 °C) and retained its activity in the presence of surfactants (SDS, Tween-80), reducing agents (DTT, 2-mercapoethanol), and organic solvents (methanol, ethanol, acetone, 2-propanol), which suggests that B. pinguin proteases are potential candidates for their application in brewing, detergent, and pharmaceutical industries.

  9. Production of selective membranes using plasma deposited nanochanneled thin films

    Directory of Open Access Journals (Sweden)

    Rodrigo Amorim Motta Carvalho

    2006-12-01

    Full Text Available The hydrolization of thin films obtained by tetraethoxysilane plasma polymerization results in the formation of a nanochanneled silicone like structure that could be useful for the production of selective membranes. Therefore, the aim of this work is to test the permeation properties of hydrolyzed thin films. The films were tested for: 1 permeation of polar organic compounds and/or water in gaseous phase and 2 permeation of salt in liquid phase. The efficiency of permeation was tested using a quartz crystal microbalance (QCM technique in gas phase and conductimetric analysis (CA in liquid phase. The substrates used were: silicon for characterization of the deposited films, piezoelectric quartz crystals for tests of selective membranes and cellophane paper for tests of permeation. QCM analysis showed that the nanochannels allow the adsorption and/or permeation of polar organic compounds, such as acetone and 2-propanol, and water. CA showed that the films allow salt permeation after an inhibition time needed for hydrolysis of the organic radicals within the film. Due to their characteristics, the films can be used for grains protection against microorganism proliferation during storage without preventing germination.

  10. Development of a capillary electrophoresis-mass spectrometry method using polymer capillaries for metabolomic analysis of yeast.

    Science.gov (United States)

    Tanaka, Yoshihide; Higashi, Tetsuji; Rakwal, Randeep; Wakida, Shin-ichi; Iwahashi, Hitoshi

    2008-05-01

    Metabolomics is an emerging field in analytical biochemistry, and the development of such a method for comprehensive and quantitative analysis of organic acids, carbohydrates, and nucleotides is a necessity in the era of functional genomics. When a concentrated yeast extract was analyzed by CE-MS using a successive multiple ionic-polymer layer (SMIL)-coated capillary, the adsorption of the contaminants on the capillary wall caused severe problems such as no elution, band-broadening, and asymmetric peaks. Therefore, an analytical method for the analysis of anionic metabolites in yeast was developed by pressure-assisted CE using an inert polymer capillary made from poly(ether etherketone) (PEEK) and PTFE. We preferred to use the PEEK over the PTFE capillary in CE-MS due to the easy-to-use PEEK capillary and its high durability. The separation of anionic metabolites was successfully achieved with ammonium hydrogencarbonate/formate buffer (pH 6.0) as the electrolyte solution. The use of 2-propanol washing after every electrophoresis run not only eliminated wall-adsorption phenomena, but allowed for good repeatability to be obtained for migration times in the metabolomic analysis.

  11. Synthesis and Anticancer Activity of Some New S-Glycosyl and S-Alkyl 1,2,4-Triazinone Derivatives

    Directory of Open Access Journals (Sweden)

    Hosam A. Saad

    2011-07-01

    Full Text Available A series of S-glycosyl and S-alkyl derivatives of 4-amino-3-mercapto-6-(2-(2-thienylvinyl-1,2,4-triazin-5(4H-one (1 were synthesized using different halo compounds such as preacetylated sugar bromide, 4-bromobutylacetate, 2-acetoxyethoxy-methyl bromide, 3-chloropropanol, 1,3-dichloro-2-propanol, epichlorohydrin, allyl bromide, propargyl bromide, phthalic and succinic acids in POCl3. The structures of the synthesized compounds have been deduced from their elemental analysis and spectral (IR, 1H-NMR, and 13C-NMR data. Some of the synthesized compounds were screened as anticancer agents. Significant anticancer activities were observed in vitro for some members of the series, and compounds 4-Amino-3-(3-hydroxypropylthio-6-(2-(2-thienylvinyl-1,2,4-triazin-5(4H-one (12 and 3-(4-Oxo-3-(2-(2-thienylvinyl-4H-[1,3,4]thiadiazolo-[2,3-c][1,2,4]tr-iazin-7-ylpropanoic acid (18 are active cytotoxic agents against different cancer cell lines.

  12. A combination of solvent extraction and freeze thaw for oil recovery from petroleum refinery wastewater treatment pond sludge.

    Science.gov (United States)

    Hu, Guangji; Li, Jianbing; Hou, Haobo

    2015-01-01

    A combination of solvent extraction and freeze thaw was examined for recovering oil from the high-moisture petroleum refinery wastewater treatment pond sludge. Five solvents including cyclohexane (CHX), dichloromethane (DCM), methyl ethyl ketone (MEK), ethyl acetate (EA), and 2-propanol (2-Pro) were examined. It was found that these solvents except 2-Pro showed a promising oil recovery rate of about 40%, but the recycling of DCM solvent after oil extraction was quite low. Three solvents (CHX, MEK and EA) were then selected for examining the effect of freeze/thaw treatment on improving the quality of recovered oil. This treatment increased the total petroleum hydrocarbon (TPH) content in recovered oil from about 40% to 60% for both MEK and EA extractions, but little effect was observed for CHX extraction. Although the solid residue after oil recovery had a significantly decreased TPH content, a high concentration of heavy metals was observed, indicating that this residue may require proper management. In general, the combination of solvent extraction with freeze/thaw is effective for high-moisture oily hazardous waste treatment.

  13. Applications of SFC-MS to toxins and compounds of biological interest

    Energy Technology Data Exchange (ETDEWEB)

    Udseth, H.R.; Kalinoski, H.T.; Smith, R.D.

    1988-06-01

    The principal applications of supercritical fluid chromatography (SFC) are for compounds that are thermally labile, of low volatility, and of low to moderate polarity. Many compounds of biological and pharmaceutical interest are defined by these criteria. We have examined selected compounds of moderate to high molecular weight with biological activity. We have used the HFR interface with CO/sub 2/ as the mobile phase with from 2 to 5% modifier. One class of compounds potentially addressable by SFC-MS are cyclic peptides. These polar compounds require the use of polar fluid modifiers with CO/sub 2/ as the mobile phase. The ionic nature of the more hydrophilic portions of such polypeptides can sometimes be shielded, allowing solvation in supercritical fluid solvents. Cyclosporin A was successfully separated by SFC-MS using a microbore column using a 2% methanol modifier. The compound was also successfully separated with a capillary column. With the capillary column 2% 2-propanol was adequate, whereas with the microbore column more polar methanol was needed. The mass spectra were identical in both cases. We also analyzed the sodium salt of two ionic polyethers, digitoxigenin, digoxigenin, and cymarin. Results are briefly discussed. 5 refs.

  14. Computational and experimental studies of 2-[(E)-hydrazinylidenemethyl]-6-methoxy-4-[(E)-phenyldiazenyl]phenol and its tautomers

    Science.gov (United States)

    Sayin, Koray; Kurtoglu, Nurcan; Kose, Muhammet; Karakas, Duran; Kurtoglu, Mukerrem

    2016-09-01

    A new azo-chromophore group containing a hydrazine-Schiff base compound, 2-[(E)-hydrazinylidenemethyl]-6-methoxy-4-[(E)-phenyldiazenyl]phenol, was synthesized and structurally characterized by single crystal X-ray diffraction study. The compound was found to crystallise in orthorhombic crystal system with Pca2(1) space group. In the structure, the molecule exhibits a phenol-imine intramolecular hydrogen bond and the sbnd NH2 group also involves in intermolecular hydrogen bonding with one of the nitrogen atom of the azo group (-Ndbnd N-) forming a 1D zigzag chain. Computational studies were performed on the titled compound and its tautomers. As computationally, this compound and its tautomers were optimized by using M062X/6-311G(d,p) level. According to thermodynamic parameters, the most stable tautomer was found to be azo-enol form. This result was then taken into account and spectral studies, which are IR, UV-Vis and NMR spectra, of this compound were performed and examined in detail. All calculations were performed at gas phase (ε = 1.000), 2-propanol (ε = 19.264), 1,2-ethanediol (ε = 40.245), water (ε = 78.355), formamide (ε = 108.940) and N-methylformamide-mixture (ε = 181.560).

  15. Conventional Chiralpak ID vs. capillary Chiralpak ID-3 amylose tris-(3-chlorophenylcarbamate)-based chiral stationary phase columns for the enantioselective HPLC separation of pharmaceutical racemates.

    Science.gov (United States)

    Ahmed, Marwa; Gwairgi, Marina; Ghanem, Ashraf

    2014-11-01

    A comparative enantioselective analysis using immobilized amylose tris-(3-chlorophenylcarbamate) as chiral stationary phase in conventional high-performance liquid chromatography (HPLC) with Chiralpak ID (4.6 mm ID × 250 mm, 5 µm silica gel) and micro-HPLC with Chiralpak ID-3 (0.30 mm ID × 150 mm, 3 µm silica gel) was conducted. Pharmaceutical racemates of 12 pharmacological classes, namely, α- and β-blockers, anti-inflammatory drugs, antifungal drugs, dopamine antagonists, norepinephrine-dopamine reuptake inhibitors, catecholamines, sedative hypnotics, diuretics, antihistaminics, anticancer drugs, and antiarrhythmic drugs were screened under normal phase conditions. The effect of an organic modifier on the analyte retentions and enantiomer recognition was investigated. Baseline separation was achieved for 1-acenaphthenol, carprofen, celiprolol, cizolirtine carbinol, miconazole, tebuconazole, 4-hydroxy-3-methoxymandelic acid, 1-indanol, 1-(2-chlorophenyl)ethanol, 1-phenyl-2-propanol, flavanone, 6-hydroxyflavanone, 4-bromogluthethimide, and pentobarbital on the 4.6 mm ID packed with a 5 µm silica column using conventional HPLC. Nonetheless, baseline separation was achieved for aminoglutethimide, naftopidil, and thalidomide on the 0.3 mm ID packed with a 3 µm silica capillary column.

  16. Determination of the mixture in a reaction of glycerol with hydrochloric acid by gas chromatography%气相色谱法测定甘油与盐酸反应过程的混合物

    Institute of Scientific and Technical Information of China (English)

    尤小姿; 李华荣; 罗正鸿

    2009-01-01

    采用气相色谱方法分析了甘油与盐酸反应过程中的主要物质. 使用KB-WAX毛细管柱及FID检测器, 以乙二醇作内标和甲醇定容, 并用内标法计算. 结果表明, 在程序升温下, 气相色谱内标法能使GLY, DCP, CPD等几种物质达到基线分离, 该方法能满足测试要求.%In this paper, a simple gas chromatographic method for the identification of glycerol (GLY), 1,3-dichloropropanol-2-propanol,(DCP) and 3-chloro-1,2-propandiol (CPD) in GLY chlorination reaction is described. The results are detected by KB-WAX capillary column with a flame ionization detector (FID) and calculated by an internal stand method. Glycol is used as an internal standard, and the samples are diluted with methanol. This method is simple, rapid and the results are reliable.

  17. Modelling On Photogeneration Of Hydroxyl Radical In Surface Waters And Its Reactivity Towards Pharmaceutical Wastes

    Science.gov (United States)

    Das, Radha; Vione, Davide; Rubertelli, Francesca; Maurino, Valter; Minero, Claudio; Barbati, Stéphane; Chiron, Serge

    2010-10-01

    This paper reports a simple model to describe the formation and reactivity of hydroxyl radicals in the whole column of freshwater lakes. It is based on empirical irradiation data and is a function of the water chemical composition (the photochemically significant parameters NPOC, nitrate, nitrite, carbonate and bicarbonate), the lake conformation best expressed as the average depth, and the water absorption spectrum in a simplified Lambert-Beer approach. The purpose is to derive the lifetime of dissolved molecules, due to reaction with •OH, on the basis of their second-order rate constants with the hydroxyl radical. The model was applied to two compounds of pharmaceutical wastes ibuprofen and carbamazepine, for which the second-order rate constants for reaction with the hydroxyl radical were measured by means of the competition kinetics with 2-propanol. The measured values of the rate constants are 1.0×1010 and 1.6×1010M-1 s-1 for ibuprofen and carbamazepine, respectively. The model suggests that the lifetime of a given compound can be very variable in different lakes, even more than the lifetime of different compounds in the same lake. It can be concluded that as far as the reaction with •OH, is concerned the concepts of photolability and photostability, traditionally attached to definite compounds, are ecosystem-dependent at least as much as they depend on the molecule under consideration.

  18. Preliminary assessment of mutagenic and anti-mutagenic potential of some aminoalkanolic derivatives of xanthone by use of the Vibrio harveyi assay.

    Science.gov (United States)

    Słoczyńska, Karolina; Waszkielewicz, Anna Maria; Marona, Henryk

    2014-07-01

    The Vibrio harveyi assay was used to evaluate mutagenic and anti-mutagenic effects of four new aminoalkanolic derivatives of xanthone with anticonvulsant activity, to select the potentially safe compounds for further in vivo studies in animal models. The study showed that at a concentration of 40 ng/ml the test compounds were not mutagenic. Additionally, two of the investigated compounds, namely the (R,S)-N-methyl-1-amino-2-propanol derivative of 6-methoxyxanthone (compound III) and the (R)-N-methyl-2-amino-1-butanol derivative of 7-chloroxanthone (compound IV) were strong inhibitors of the mutagenicity induced by 4-nitroquinoline-N-oxide (4-NQO) in V. harveyi strains BB7M and BB7XM. The inhibition percentages for compound IV were 49 (in BB7M) and 69 (in BB7XM), whereas for compound III these percentages were 47 (in BB7M) and 42 (in BB7XM), respectively. The present study demonstrates that four bioactive derivatives of xanthone display no mutagenic activity in the V. harveyi assay. In addition, compounds III and IV demonstrated considerable anti-mutagenic activity in this test. Based on the results obtained here, these compounds could be selected for further studies in animal models, while compounds III and IV should be tested further for their anti-mutagenic properties.

  19. A degradation study of cefepime hydrochloride in solutions under various stress conditions by TLC-densitometry.

    Science.gov (United States)

    Dąbrowska, Monika; Starek, Małgorzata; Krzek, Jan; Papp, Elżbieta; Król, Piotr

    2015-03-01

    A rapid, accurate and sensitive thin-layer chromatography (TLC) method with densitometric detection has been developed and validated for the determination of cefepime in pharmaceuticals. Chromatographic separation was achieved on a silica gel TLC F254 plates with a mobile phase consisting of ethanol-2-propanol-glacial acetic acid 99.5%-water (4:4:1:3, v/v). Densitometric detection was carried out at wavelength of 266 nm in reflectance/absorbance mode. The validation of the method was found to be satisfactory with high accuracy (from 99.24 to 101.37%) and precision (RSD from 0.06 to 0.36%). Additionally, the stability of cefepime in solution was investigated, including the effect of pH, temperature and incubation time. Favorable retention parameters (Rf , Rs, α) were obtained under the developed conditions, which guaranteed good separation of the studied components. The degradation process of cefepime hydrochloride was described by kinetic and thermodynamic parameters (k, t0.1 , t0.5 and Ea ). Moreover, the chemical properties of degradation products were characterized by the Rf values, absorption spectra, HPLC-MS/MS and TLC-densitometry analysis. As the method could effectively separate the active substance from its main degradation product (1-methylpyrrolidine), it can be employed as a method to indicate the stability of this drug.

  20. RAFT Polymerization of Styrene and Maleimide in the Presence of Fluoroalcohol: Hydrogen Bonding Effects with Classical Alternating Copolymerization as Reference

    Directory of Open Access Journals (Sweden)

    Fangjun Yao

    2017-03-01

    Full Text Available The impacts of hydrogen bonding on polymerization behavior has been of interest for a long time; however, universality and in-depth understanding are still lacking. For the first time, the effect of hydrogen bonding on the classical alternating-type copolymerization of styrene and maleimide was explored. N-phenylmaleimide (N-PMI/styrene was chosen as a model monomer pair in the presence of hydrogen bonding donor solvent 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP, which interacted with N-PMI via hydrogen bonding. Reversible addition-fragmentation chain transfer polymerization (RAFT technique was used to guarantee the “living” polymerization and thus the homogeneity of chain compositions. In comparison with the polymerization in nonhydrogen bonding donor solvent (toluene, the copolymerization in HFIP exhibited a high rate and a slight deviation from alternating copolymerization tendency. The reactivity ratios of N-PMI and St were revealed to be 0.078 and 0.068, respectively, while the reactivity ratios in toluene were 0.026 and 0.050. These interesting results were reasonably explained by using computer simulations, wherein the steric repulsion and electron induction by the hydrogen bonding between HFIP and NPMI were revealed. This work first elucidated the hydrogen bonding interaction in the classical alternating-type copolymerization, which will enrich the research on hydrogen bonding-induced polymerizations.

  1. Influence of the structure of polyfluorinated alcohols on Brønsted acidity/hydrogen-bond donor ability and consequences on the promoter effect.

    Science.gov (United States)

    Vuluga, Daniela; Legros, Julien; Crousse, Benoit; Slawin, Alexandra M Z; Laurence, Christian; Nicolet, Pierre; Bonnet-Delpon, Danièle

    2011-02-18

    The influence of substituents on the properties of tri- and hexafluorinated alcohols derived from 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) was examined. Measurements of specific solvent-solute interactions revealed that H-bond donation (HBD) of fluorinated alcohols is sensitive to the steric hindrance of the OH group, whereas their Brønsted acidity is dependent only on the number of fluorine atoms. For hexafluorinated alcohols (HFAs), their association with amines characterized by X-ray diffraction showed that the balance between HBD and acidity is influenced by their structure. Moreover, the ability of HFAs to donate H-bonds is exerted in synclinal (sc), synperiplanar (sp), and also antiperiplanar (ap) conformations along the C-O bond. Comparison of the effects of fluorinated alcohols as promoting solvents in three reactions is reported. The positive correlation between rate constants and H-bonding donation ability for sulfide oxidation and imino Diels-Alder reaction brings to light the role of this property, while acidity might have a minor influence. In the third reaction, epoxide opening by piperidine, none of these properties can clearly be put forward at this stage.

  2. Determination of alcohol compounds using corona discharge ion mobility spectrometry

    Institute of Scientific and Technical Information of China (English)

    HAN Hai-yan; HUANG Guo-dong; JIN Shun-ping; ZHENG Pei-chao; XU Guo-hua; LI Jian-quan; WANG Hong-mei; CHU Yan-nan

    2007-01-01

    Ion mobility spectrometry (IMS) is a very fast, highly sensitive, and inexpensive technique, it permits efficient monitoring of volatile organic compounds like alcohols. In this article, positive ion mobility spectra for six alcohol organic compounds have been systematically studied for the first time using a high-resolution IMS apparatus equipped with a discharge ionization source. Utilizing protonated water cluster ions (H2O)nH+ as the reactant ions and clean air as the drift gas, alcohol organic compounds, ethanol, 1-propanol, 2-propanol, 1-butanol, 1-pentanol and 2-octanol, all exhibit product ion characteristic peaks in their respective ion mobility spectrometry, that is a result of proton transfer reactions between the alcohols and reaction ions (H2O)nH+. The mixture of these alcohols, including two isomers, has been detected, and the result shows that they can also be distinguished effectively in the ion mobility spectrum. The reduced mobility values have been determined, which are in very well agreement with the traditional 63Ni-IMS experimental values. The exponential dilution method was used to calibrate the alcohol concentrations, and a detection limit available for the alcohols is in order of magnitude of a few ng/L.

  3. Extruded expanded polystyrene sheets coated by TiO{sub 2} as new photocatalytic materials for foodstuffs packaging

    Energy Technology Data Exchange (ETDEWEB)

    Loddo, V.; Marci, G. [Schiavello-Grillone Photocatalysis Group - Dipartimento di Ingegneria Elettrica, Elettronica e delle Telecomunicazioni, di tecnologie Chimiche, Automatica e modelli Matematici - Universita degli Studi di Palermo, Viale delle Scienze (Ed. 6) - 90128 Palermo (Italy); Palmisano, G., E-mail: giovanni_palmisano@yahoo.it [Schiavello-Grillone Photocatalysis Group - Dipartimento di Ingegneria Elettrica, Elettronica e delle Telecomunicazioni, di tecnologie Chimiche, Automatica e modelli Matematici - Universita degli Studi di Palermo, Viale delle Scienze (Ed. 6) - 90128 Palermo (Italy); Yurdakal, S. [Kimya Boeluemue, Fen-Edebiyat Fakueltesi, Afyon Kocatepe Ueniversitesi - Ahmet Necdet Sezer Kampuesue - 03200 Afyon (Turkey); Brazzoli, M.; Garavaglia, L. [Sirap-Gema S.p.A. - Via Industriale, 1/3 - 25028 Verolanuova (Brescia) (Italy); Palmisano, L., E-mail: leonardo.palmisano@unipa.it [Schiavello-Grillone Photocatalysis Group - Dipartimento di Ingegneria Elettrica, Elettronica e delle Telecomunicazioni, di tecnologie Chimiche, Automatica e modelli Matematici - Universita degli Studi di Palermo, Viale delle Scienze (Ed. 6) - 90128 Palermo (Italy)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer An extruded polystyrene has been functionalised by TiO{sub 2}. Black-Right-Pointing-Pointer A photocatalytic polymer has been developed via a sol-gel method. Black-Right-Pointing-Pointer Thermoformed packagings for foodstuffs application have been prepared. - Abstract: Nanostructured, photoactive anatase TiO{sub 2} sol prepared under very mild conditions using titanium tetraisopropoxide as the precursor is used to functionalise extruded expanded polystyrene (XPS) sheets by spray-coating resulting in stable and active materials functionalised by TiO{sub 2} nanoparticles. Photocatalytic tests of these sheets performed in a batch reactor in gas-solid system under UV irradiation show their successful activity in degrading probe molecules (2-propanol, trimethylamine and ethene). Raman spectra ensure the deposition of TiO{sub 2} as crystalline anatase phase on the polymer surface. The presence of TiO{sub 2} with respect to polymer surface can be observed in SEM images coupled to EDAX mapping allowing to monitor the surface morphology and the distribution of TiO{sub 2} particles. Finally thermoforming of these sheets in industrial standard equipment leads to useful containers for foodstuffs.

  4. High-performance liquid chromatography-ionspray mass spectrometry for the specific determination of digoxin and some related cardiac glycosides in human plasma.

    Science.gov (United States)

    Tracqui, A; Kintz, P; Ludes, B; Mangin, P

    1997-04-25

    An original method based upon high-performance liquid chromatography coupled to ionspray mass spectrometry (HPLC-ISP-MS) has been developed for the identification and quantification in plasma of several cardiac glycosides, namely digoxin, digitoxin, lanatoside C and acetyldigitoxin. After single-step liquid-liquid extraction by chloroform-2-propanol (95:5, v/v) at pH 9.5 using oleandrin as an internal standard, solutes are separated on a 4 microm NovaPak C18 (Waters) column (150x2.0 mm, I.D.), using a gradient of acetonitrile-2 mM NH4COOH, pH 3 buffer (flow-rate 200 microl/min, post-column split 1:3). Detection is done by a Perkin-Elmer Sciex API-100 mass analyzer equipped with an ISP interface. In most instances the major ion observed is not [M+H]+ as expected, but [M+NH4]+. The mean retention times (min) are: lanatoside C, 5.74; digoxin, 6.00; digitoxin, 8.08, oleandrin, 8.30, acetyldigitoxin, 8.66 and 9.01 (isomers alpha and beta, respectively). The lower limits of detection in single ion monitoring mode range from 0.15 ng/ml (alpha- and beta-acetyldigitoxin) to 0.60 ng/ml (lanatoside C), making the method less sensitive than radioimmunoassay, whereas it is much more specific.

  5. Intercalation Pseudocapacitance in Ultrathin VOPO4 Nanosheets: Toward High-Rate Alkali-Ion-Based Electrochemical Energy Storage.

    Science.gov (United States)

    Zhu, Yue; Peng, Lele; Chen, Dahong; Yu, Guihua

    2016-01-13

    There is a growing need for energy storage devices in numerous applications where a large amount of energy needs to be either stored or delivered quickly. The present paper details the study of alkali-ion intercalation pseudocapacitance in ultrathin VOPO4 nanosheets, which hold promise in high-rate alkali-ion based electrochemical energy storage. Starting from bulk VOPO4·2H2O chunks, VOPO4 nanosheets were obtained through simple ultrasonication in 2-propanol. These nanosheets as the cathode exhibit a specific capacity of 154 and 136 mAh/g (close to theoretical value 166 mAh/g) for lithium and sodium storage devices at 0.1 C and 100 and ∼70 mAh/g at 5 C, demonstrating their high rate capability. Moreover, the capacity retention is maintained at 90% for lithium ion storage and 73% for sodium ion storage after 500 cycles, showing their reasonable stability. The demonstrated alkali-ion intercalation pseudocapacitance represents a promising direction for developing battery materials with promising high rate capability.

  6. Enantioseparation Using Cellulose Tris(3,5-dimethylphenylcarbamate as Chiral Stationary Phase for HPLC: Influence of Molecular Weight of Cellulose

    Directory of Open Access Journals (Sweden)

    Yuji Okada

    2016-11-01

    Full Text Available The cellulose oligomers with different degrees of polymerization (DP, 7, 11, 18, 24, 26, 40 and 52, were prepared by hydrolysis of microcrystalline cellulose with phosphoric acid. These oligomers including the starting microcrystalline cellulose (DP 124 were converted to tris(3,5-dimethylphenylcarbamate (CDMPC derivatives by the reaction with an excess of 3,5-dimethylphenyl isocyanate to be used as the chiral stationary phase (CSP in high-performance liquid chromatography (HPLC. The structures of the CDMPC derivatives were investigated by infrared spectroscopy (IR, 1H-NMR, circular dichroism (CD and size exclusion chromatography (SEC, and the DPs of the derivatives estimated by SEC agreed with those estimated by 1H-NMR. After coating the derivatives on silica gel, their chiral recognition abilities were evaluated using eight racemates under a normal phase condition with a hexane-2-propanol (99/1 mixture as an eluent. The chiral recognition abilities of 7- and 11-mers, particularly the former, were lower than those of the higher oligomers from DP 18 to 52, which had rather similar abilities to that of 124-mer, although the abilities depended on the racemates. DP 18 seems to be sufficient for CDMPC to exhibit chiral recognition similar to that of the CDMPC with larger DPs.

  7. Ion-pair chromatography coupled to inductively coupled plasma-mass spectrometry (IPC-ICP-MS) as a method for thiomolybdate speciation in natural waters.

    Science.gov (United States)

    Lohmayer, Regina; Reithmaier, Gloria Maria Susanne; Bura-Nakić, Elvira; Planer-Friedrich, Britta

    2015-03-17

    Molybdenum precipitates preferentially under reducing conditions; therefore, its occurrence in sediment records is used as an indicator of paleoredox conditions. Although thiomolybdates (MoO4-xSx(2-) with x = 1-4) supposedly are necessary intermediates in the process of molybdenum precipitation under anoxic conditions, there is no information about their abundance in natural environments, because of a lack of element-specific methods with sufficiently low detection limits. Here, we optimized ion-pair chromatographic separation for coupling to an inductively coupled plasma-mass spectrometry detector (IPC-ICP-MS). 2-Propanol (10%-25% gradient) replaced the previously used acetonitrile (25%-75%) as the solvent, to reduce the carbon load into the plasma. In synthetic solutions, formation of thiomolybdates was found to occur spontaneously in the presence of excess sulfide and the degree of thiolation was highest at pH 7. Excess hydroxyl led to a transformation of thiomolybdates to molybdate. Under acidic to neutral conditions, precipitation of molybdenum and hydrolysis of tetrathiomolybdate were observed. Flash-freezing was found to be suitable to stabilize tetrathiomolybdate, with 2 mM) negatively affected the detection of molybdate, which eluted mainly in the dead volume, but had no negative effect on higher thiolated molybdates. Detection limits were ∼10 nM. With the newly developed IPC-ICP-MS method, thiomolybdates were found to form spontaneously in euxinic marine waters after adding a molybdate spike and occur naturally in sulfidic geothermal waters.

  8. Coordination of the New Schiff Base with Copper(Ⅱ) or Iron(Ⅲ) in Solution%新席夫碱与铜(Ⅱ)、铁(Ⅲ)在溶液中的配位反应研究

    Institute of Scientific and Technical Information of China (English)

    郑璇; 赵毅; 朱必学

    2011-01-01

    A new Schiff base C33H31N4O5(L) was synthesized from l-(3-pyridyl)-l, 3-butanedione and 1, 3-bis(2-aminophenoxyl)-2-propanol. The structure of the Schiff base was determined by X-ray diffraction analysis. Furthermore, the coordination reaction of the Schiff base with Cu(II) or Fe(DD was investigated via UV-Vis spectroscopy, the stability constants of the two complexes were determined respectively. CCDC: 797351.%以1-(3-吡啶基)-1,3-丁二酮和1.3-二(2-胺基苯氧基)-2-丙醇进行缩合得到席夫碱1,3-二(2-胺基苯氧基)-2-丙醇缩双1-(3-吡啶基)丁烷-1,3-丁二酮(L),并通过单晶X射线衍射解析了Schiff碱配体(L)的结构.进一步将Schiff碱配体L与金属铜(Ⅱ)、铁(Ⅲ)进行配位反应.采用UV-Vis光谱技术,分别测定了铜(Ⅱ)、铁(Ⅲ)配合物的稳定常数.

  9. Charge-transfer complexes of 4-nitrocatechol with some amino alcohols

    Science.gov (United States)

    Baniyaghoob, Sahar; Najafpour, Mohammad Mahdi; Boghaei, Davar M.

    2010-03-01

    Charge-transfer (CT) complexes formed from the reactions of 4-nitropyrocatechol (4-nCat) as an electron acceptor with four amino alcohols: 2-aminoethanol, 1-amino-2-propanol, 4-aminobutanol and N-(2-hydroxyethyl)-1,3-diaminopropane (NHEDAP) as electron donors, have been studied spectrophotometrically in H 2O and H 2O/EtOH at 20, 25, 30, 35 and 40 °C. The calculated values of the oscillator strength and transition moment confirm the formation of CT-complexes. The thermodynamic and spectroscopic parameters were also evaluated for the formation of CT-complexes. The equilibrium constants ranged from 9.00 to 2.20 l mol -1 (M -1). These interactions are exothermic and have relatively large standard enthalpy and entropy changes (Δ H values ranged from -15.58 to -3.10 kJ mol -1; Δ S ranged from 26.81 to -3.25 J K -1 mol -1). The solid CT-complexes have been synthesized and characterized by IR, NMR, mass spectrometry and thermal analysis. The photometric titration curves and other spectrometric data for the reactions indicated that the data obtained refer to the formation of 1:1 charge-transfer complex of [(4-nCat) (NHEDAP)] and 1:2 charge-transfer complexes of other amino alcohols [(4-nCat) (amino alcohol) 2]. The effect of alkali and alkaline earth metals on increasing the equilibrium constant of the CT-complexation was also investigated.

  10. Acid lipase from Candida viswanathii: production, biochemical properties, and potential application.

    Science.gov (United States)

    de Almeida, Alex Fernando; Tauk-Tornisielo, Sâmia Maria; Carmona, Eleonora Cano

    2013-01-01

    Influences of environmental variables and emulsifiers on lipase production of a Candida viswanathii strain were investigated. The highest lipase activity (101.1 U) was observed at 210 rpm, pH 6.0, and 27.5°C. Other fermentation parameters analyzed showed considerable rates of biomass yield (Y L/S = 1.381 g/g), lipase yield (Y L/S = 6.892 U/g), and biomass productivity (P X = 0.282 g/h). Addition of soybean lecithin increased lipase production in 1.45-fold, presenting lipase yield (Y L/S ) of 10.061 U/g. Crude lipase presented optimal activity at acid pH of 3.5, suggesting a new lipolytic enzyme for this genus and yeast in general. In addition, crude lipase presented high stability in acid conditions and temperature between 40 and 45°C, after 24 h of incubation in these temperatures. Lipase remained active in the presence of organic solvents maintaining above 80% activity in DMSO, methanol, acetonitrile, ethanol, acetone, 1-propanol, isopropanol, and 2-propanol. Effectiveness for the hydrolysis of a wide range of natural triglycerides suggests that this new acid lipase has high potential application in the oleochemical and food industries for hydrolysis and/or modification of triacylglycerols to improve the nutritional properties.

  11. Acid Lipase from Candida viswanathii: Production, Biochemical Properties, and Potential Application

    Directory of Open Access Journals (Sweden)

    Alex Fernando de Almeida

    2013-01-01

    Full Text Available Influences of environmental variables and emulsifiers on lipase production of a Candida viswanathii strain were investigated. The highest lipase activity (101.1 U was observed at 210 rpm, pH 6.0, and 27.5°C. Other fermentation parameters analyzed showed considerable rates of biomass yield ( g/h. Addition of soybean lecithin increased lipase production in 1.45-fold, presenting lipase yield ( of 10.061 U/g. Crude lipase presented optimal activity at acid pH of 3.5, suggesting a new lipolytic enzyme for this genus and yeast in general. In addition, crude lipase presented high stability in acid conditions and temperature between 40 and 45°C, after 24 h of incubation in these temperatures. Lipase remained active in the presence of organic solvents maintaining above 80% activity in DMSO, methanol, acetonitrile, ethanol, acetone, 1-propanol, isopropanol, and 2-propanol. Effectiveness for the hydrolysis of a wide range of natural triglycerides suggests that this new acid lipase has high potential application in the oleochemical and food industries for hydrolysis and/or modification of triacylglycerols to improve the nutritional properties.

  12. Amine-modified SBA-15 and MCF mesoporous molecular sieves as promising sorbents for natural antioxidant. Modeling of caffeic acid adsorption.

    Science.gov (United States)

    Moritz, Michał; Geszke-Moritz, Małgorzata

    2016-04-01

    This work presents a detailed study of caffeic acid adsorption on mesoporous SBA-15 and MCF silicas functionalized with (3-aminopropyl)triethoxysilane (APTES) and 3-[2-(aminoethylamino)propyl]trimethoxysilane (AEAPTMS). Synthesized mesoporous adsorbents were characterized using different analytical techniques such as N2 sorption, XRD, TEM, SEM and FT-IR. The adsorption studies of caffeic acid were conducted in various organic solvents. Moreover, the effect of water content in 2-propanol-water mixture on adsorption efficiency was investigated. The experimental data were best fitted to the Langmuir equation, followed by the Temkin, Dubinin-Radushkevich and Freundlich models. The maximum adsorption capacity values calculated from the Langmuir model demonstrated that SBA-15 and MCF silicas modified with AEAPTMS revealed better adsorption properties toward caffeic acid (192.3 and 161.3mg/g, respectively) as compared to the materials modified with APTES (125.0 and 113.6 mg/g, respectively). The obtained results indicate that both SBA-15 and MCF silicas functionalized with AEAPTMS and APTES are promising materials for the entrapment of caffeic acid.

  13. Catalytic Hydrogenation of Methanol-Containing Eflfuent from Epoxidation of Propylene

    Institute of Scientific and Technical Information of China (English)

    Cheng Ke

    2015-01-01

    This paper describes the hydrogenation of impurities in the methanol-containing eflfuent from the propylene epoxidation process with hydrogen peroxide. The effects of reaction temperature, pressure, weight hourly space velocity (WHSV) and H2/methanol ratio on the concentration of various impurities in methanol solvent were investigated. It was found out that the aldehyde, hydrogen peroxide and nitro compounds in the methanol solvent could be completely hydroge-nated over the Ni catalyst under proper reaction conditions. 90%of acetone and up to 50%of acetals (ketals) existing in the methanol solvent could be hydrogenated. No signiifcant change was observed for the rest of the impurities that were present in the methanol solvent (i. e., 1-methoxy-2-propanol, 2-methoxy-1-propanol and 1,2-propanediol). The H2O2 decomposition reaction was enhanced using Ni catalyst, through the formation of NioOH, but no oxygen was found in the off-gas of hy-drogenation reaction since NioH could react on NioOH formed via dissociative adsorption of hydrogen peroxide, or on NioO formed via adsorption of oxygen.

  14. Linear and nonlinear optical studies of bare and copper doped TiO2 nanoparticles via sol gel technique.

    Science.gov (United States)

    Rajamannan, B; Mugundan, S; Viruthagiri, G; Praveen, P; Shanmugam, N

    2014-01-24

    In general, the nanoparticles of TiO2 may exist in the phases of anatase, rutile and brookite. In the present work, we used titanium terta iso propoxide and 2-propanol as a common starting material to prepare the precursors of bare and copper doped nanosized TiO2. Then the synthesized products were calcinated at 500°C and after calcination the pure TiO2 nanoparticles in anatase phase were harvested. The crystallite sizes of bare and copper doped TiO2 nanoparticles were calculated from X-ray diffraction analysis. The existence of functional groups of the samples was identified by Fourier transform infrared spectroscopy. The optical properties of bare and doped samples were carried out using UV-DRS and photoluminescence measurements. The surface morphology and the element constitution of the copper doped TiO2 nanoparticles were studied by scanning electron microscope fitted with energy dispersive X-ray spectrometer arrangement. The nonlinear optical properties of the products were confirmed by Kurtz second harmonic generation (SHG) test and the output power generated by the nanoparticle was compared with that of potassium di hydrogen phosphate (KDP).

  15. Synthesis, characterization and application of naïve and nano-sized titanium dioxide as a photocatalyst for degradation of methylene blue

    Directory of Open Access Journals (Sweden)

    Arpita Pandey

    2015-09-01

    Full Text Available In the present work, photocatalytic degradation of methylene blue has been carried out using naïve titanium dioxide, nano-sized titanium dioxide and H2O2 under visible light. The catalysts, naïve and nano-sized titanium dioxide were prepared by the sol–gel method. Characterization of synthesized catalysts has been done by scanning electron microscopy (SEM, X-ray diffraction (XRD and UV–Visible spectroscopy. The rate of degradation of dye was monitored spectrophotometrically by measuring absorbance of dye at regular time intervals. The effect of various parameters such as pH, concentration of dye, amount of catalyst, amount of H2O2 and light intensity on the rate of reaction has been studied. Various parameters like chemical oxygen demand (COD, conductance, pH, TDS, salinity and dissolved oxygen (DO for the reaction mixture have also been determined. A tentative mechanism for degradation of dye has been proposed involving ·−OH radical as an oxidant. The participation of ·−OH radical has been confirmed by using 2-propanol (scavenger as the rate of reaction was drastically reduced in its presence.

  16. Preparation of Pt Au/C and Pt Au Bi/C electrocatalysts using electron beam irradiation for ethanol electro-oxidation in alkaline medium

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio F.; Geraldes, Adriana N.; Cardoso, Elisangela S.Z.; Gomes, Thiago B.; Linardi, Marcelo; Oliveira Neto, Almir; Spinace, Estevam V., E-mail: dfsilva@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Pt Au/C (50:50) and PtAuBi/C electrocatalysts with Pt:Au:Bi atomic ratios of 50:40:10, 50:30:20 and 50:10:40 were prepared in water/2-propanol using electron beam irradiation. The materials were characterized by X-ray diffraction (XRD) and the electro-oxidation of ethanol was studied by chronoamperometry at room temperature. The X-ray diffraction measurements for all electrocatalysts prepared showed four peaks, which are associated with the planes of the face-centered cubic (fcc) structure characteristic of Pt and Pt alloys. For PtAuBi/C it was also observed the presence of a mixture of BiPt alloys and bismuth phases. The average crystallite sizes for Pt/C, PtAu/C, PtAuBi/C (50:40:10), PtAuBi/C (50:30:20) and PtAuBi/C (50:10:40) were in the range of 2.0 - 4.0 nm. The activity of the electrocatalysts for ethanol oxidation in alkaline medium showed that PtAuBi/C (50:40:10) had a higher performance for ethanol oxidation compared to others electrocatalysts prepared. (author)

  17. HPLC Analysis of Egg Yolk Phosphatidylcholine by Evaporative Light Scattering Detector

    Institute of Scientific and Technical Information of China (English)

    周婧; 胡仙妹; 王田心; 梁浩; 袁其朋

    2012-01-01

    Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids were based on the American Oil Chemists' Society(AOCS) Official Method Ja7b-91,in which n-hexane/2-propanol/acetate buffer was used as the mobile phase.In order to achieve desired results,gradient elu-tion or buffer solution was used,which made the detection process more complicated.Moreover,water or buffer solution could affect the silica gel column both on its lifespan and the separation efficiency significantly.In this study,different mobile phase and detector were used to simplify EYPC analyzing process instead of using water within the mobile phase.The optimized HPLC operating conditions are as follows:pure methanol as a mobile phase,flow rate of 1.0 ml·min-1,silica gel column(250 mm×4.6 mm,5 μm,Inertsil GLTM),column temperature 30 ℃ and low temperature evaporative light scattering detector(40 ℃,0.35 MPa) as used.Under this optimal condition,the linear relative coefficient of the standard curve is 0.998 and the recovery was in the range of 96.83%-101.58% with a relative standard deviation of 1.79%(n=6).

  18. Bioconversion of isopropanol by a solvent tolerant Sphingobacterium mizutae strain.

    Science.gov (United States)

    Mohammad, Balsam T; Wright, Phillip C; Bustard, Mark T

    2006-12-01

    The bioconversion of high concentration isopropanol (2-propanol, IPA) was investigated by a solvent tolerant strain of bacteria, which was identified as Sphingobacterium mizutae ST2 by partial 16S rDNA gene sequencing. This strain of bacteria exhibited the ability to utilise high concentration isopropanol as the sole carbon source, with mineralization occurring via an acetone intermediate into central metabolism. The biodegradative performance of this strain for IPA was examined over a 2-38 g l(-1) concentration range, using specific growth rate (mu) and conversion rate analysis. Maximum specific growth rates (mu(max)) of 0.0045 h(-1 )were routinely obtainable on IPA. In addition, the highest specific IPA degradation rate was obtained at a concentration of 7.5 g l(-1) with a corresponding value of 0.045 g IPA g cells(-1) h(-1). While the highest acetone yield reached its maximum value of 0.940 g acetone g IPA(-1) at 7.5 g IPA l(-1). This is the first report on bioconversion of isopropanol at such high concentration by this solvent tolerant strain of S. mizutae and may allow its application in novel biocatalytic processes for effective biological conversion in two-phase solvent systems.

  19. Unexpected photoproduct generated via the acetone-sensitized photolysis of 5-bromo-2'-deoxyuridine in a water/isopropanol solution: experimental and computational studies.

    Science.gov (United States)

    Polska, Katarzyna; Zielonka, Justyna; Chomicz, Lidia; Czerwicka, Małgorzata; Stepnowski, Piotr; Guzow, Katarzyna; Wiczk, Wiesław; Smużyńska, Maria; Kasprzykowski, Franciszek; Żylicz-Stachula, Agnieszka; Skowron, Piotr; Rak, Janusz

    2010-12-23

    The acetone-sensitized photolysis of 5-bromo-2'-deoxyuridine (5-BrdU) in a water/isopropanol solution with 300 nm photons leads to the formation of 2'-deoxyuridine (dU) and a comparable amount of another photoproduct that has not been reported in the literature so far. The negative and positive mass spectra recorded for this species indicate that they originate from the molecular mass of 286 Da, which corresponds to an adduct of 2'-deoxyuridine and 2-propanol. Quantum chemical calculations carried out at the DFT and TDDFT levels reveal both the structure and the UV spectrum of that adduct. The latter computational characteristic matches well the experimental UV spectrum of the new photoproduct. Our findings indicate that the acetone-sensitized photolysis of 5-BrdU is more complicated than has hitherto been assumed. Nevertheless, since electron transfer is one of the pathways responsible for 5-BrdU decay, acetone-sensitized photolysis of the halogen derivatives of nucleobases could be a convenient tool for studying their radiosensitivity in aqueous solutions.

  20. Determining indoor air quality and identifying the origin of odour episodes in indoor environments

    Institute of Scientific and Technical Information of China (English)

    Eva Gallego; Xavier Roca; Jose Francisco Perales; Xavier Guardino

    2009-01-01

    A methodology for identifying volatile organic compounds (VOC) and determining air quality of indoor air has been developed. The air samples are collected using pump samplers by the inhabitants when they perceive odorous and/or discomfort episodes. Glass multi-sorbent tubes are connected to the pump samplers for the retention of VOC. The analysis is performed by automatic thermal desorption (ATD) coupled with gas chromatography-mass spectrometry (GC/MS). This methodology can be applied in cases of sick building syndrome (SBS) evaluation, in which building occupants experience a series of varied symptoms that appear to be linked to time spent in the building. Chemical pollutants concentrations (e.g., VOC) have been described to contribute to SBS. To exemplify the methodology, a qualitative determination and an evaluation of VOC present were performed in a dwelling where the occupants experienced the SBS symptoms. Higher total VOC (TVOC) value was detected in episodes in indoor air (1.33 ( 1.53 mg/m3) compared to outdoor air (0.71 ( 0.46 mg/m3). The concentrations of individual VOCs, such as ethanol, acetone, isopropanol, 1-butanol, acetic acid, acetonitrile and 1-metoxy-2-propanol, were also higher than the expected for a standard dwelling. The external source of VOC was found to be a not declared activity of storage and manipulation of solvents located at the bottom of a contiguous building.

  1. Biodegradation of isopropanol by a solvent-tolerant Paracoccus denitrificans strain.

    Science.gov (United States)

    Geng, Yucong; Deng, Yuanjie; Chen, Feilong; Jin, Hong; Tao, Ke; Hou, Taiping

    2015-01-01

    The biodegradation of high concentration isopropanol (2-propanol, IPA) at 16 g/L was investigated by a solvent-tolerant strain of bacteria identified as Paracoccus denitrificans for the first time by 16S rDNA gene sequencing. The strain P. denitrificans GH3 was able to utilize the high concentration of IPA as the sole carbon source within a minimal salts medium with a cell density of 1.5×10(8) cells/mL. The optimal conditions were found as follows: initial pH 7.0, incubation temperature 30°C, with IPA concentration 8 g/L. Under the optimal conditions, strain GH3 utilized 90.3% of IPA in 7 days. Acetone, the major intermediate of aerobic IPA biodegradation, was also monitored as an indicator of microbial IPA utilization. Both IPA and acetone were completely removed from the medium following 216 hr and 240 hr, respectively. The growth of strain GH3 on IPA as a sole carbon and energy source was well described by the Andrews model with a maximum growth rate (μmax)=0.0277/hr, a saturation constant (KS)=0.7333 g/L, and an inhibition concentration (Ki)=8.9887 g/L. Paracoccus denitrificans GH3 is considered to be well used in degrading IPA in wastewater.

  2. Effect of Water Miscible Organic Solvents on p-Nitrophenol Hydroxylase (CYP2E1) Activity in Rat Liver Microsomes.

    Science.gov (United States)

    Patil, Pranali G; Kamble, S H; Shah, T S; Iyer, K R

    2015-01-01

    Organic solvents used for solubilization of the substrates/NCEs are known to affect the activity of cytochrome P450 enzymes. Further, this effect varies with the solvents used, the substrates and CYP450 isoforms in question. In the present study, we have investigated the effect of ten commonly used water miscible organic solvents (methanol, ethanol, 1-propanol, 2-propanol, acetonitrile, acetone, dimethyl sulphoxide, N,N-dimethyl formamide, dioxane and polyethylene glycol 400) on p-nitrophenol hydroxylase activity at 0, 0.1, 0.25, 0.5, 0.75 and 1% v/v concentration in rat liver microsomes. All the solvents studied showed concentration dependent inhibition of the p-nitrophenol hydroxylase activity except acetonitrile which showed activation of the activity at concentration range studied. Out of ten solvents studied, dioxane was found to be the most inhibitory solvent (inhibition >90% at 0.25% v/v concentration). Overall, solvents like dimethyl sulphoxide, dimethyl formamide and dioxane appeared to be unsuitable for characterizing p-nitrophenol hydroxylase (CYP2E1-mediated) reactions due to a high degree of inhibition. On the other hand, methanol and acetonitrile at concentrations <0.5% v/v appeared to be appropriate solvents for substrate solubilization while evaluating CYP2E1-mediated catalysis. The results of this study imply that caution should be exercised while choosing solvents for dissolution of substrate during enzyme studies in liver microsomes.

  3. Bio-inspired 2-line ferrihydrite as a high-capacity and high-rate-capability anode material for lithium-ion batteries

    Science.gov (United States)

    Hashimoto, Hideki; Ukita, Masahiro; Sakuma, Ryo; Nakanishi, Makoto; Fujii, Tatsuo; Imanishi, Nobuyuki; Takada, Jun

    2016-10-01

    A high-capacity and high-rate-capability anode material for lithium-ion batteries, silicon-doped iron oxyhydroxide or 2-line ferrihydrite (2Fh), was prepared by mixing iron nitrate powder, tetraethyl orthosilicate, 2-propanol, and ammonium hydrogen carbonate powder at room temperature. The design of this material was inspired by a bacteriogenic product, a nanometric amorphous iron-based oxide material containing small amounts of structural Si. The atomistic structure of the prepared Si-doped 2Fh was strongly affected by the Si molar ratio [x = Si/(Fe + Si)]. Its crystallinity gradually decreased as the Si molar ratio increased, with a structural variation from nanocrystalline to amorphous at x = 0.25. The sample with x = 0.20 demonstrated the best Li storage performance. The developed material exhibited a high capacity of ∼400 mAh g-1 at the 25th cycle in the voltage range of 0.3-3.0 V and at a current rate of 9 A g-1, which was three times greater than that of the Si-free 2Fh. This indicates that Si-doping into the 2Fh structure realizes good rate capability, which are presumably because of the specific nanocomposite structure of iron-based electrochemical centers embedded in the Si-based amorphous matrix, generated by reversible Li insertion/deinsertion process.

  4. Platinum-Niobium(V Oxide/Carbon Nanocomposites Prepared By Microwave Synthesis For Ethanol Oxidation

    Directory of Open Access Journals (Sweden)

    Virginija KEPENIENĖ

    2016-05-01

    Full Text Available In the present work, Pt nanoparticles were deposited by means of microwave synthesis on the primary carbon supported Nb2O5 composite which was prepared in two different ways: (A by dispersion of Nb2O5 and carbon with the mass ratio equal to 1:1 in a 2-propanol solution by ultrasonication for 30 min. with further desiccation of the mixture and (B by heating the Nb2O5/C composite obtained according to the procedure (A at 500 °C for 2 h. The transmission electron microscopy was used to determine the shape and the size of catalyst particles. X-ray diffraction and inductively coupled plasma optical emission spectroscopy were employed to characterize the structure and composition of the synthesized catalysts. The electrocatalytic activity of the synthesized catalysts towards the oxidation of ethanol in an alkaline medium was investigated by means of cyclic voltammetry.DOI: http://dx.doi.org/10.5755/j01.ms.22.2.8609

  5. Synthesis of {sup 14}C-labelled hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,4,6-trinitrotoluene (TNT), nitrocellulose (NC) and glycidyl azide polymer (GAP) for use in assessing the biodegradation potential of these energetic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ampleman, G.; Thiboutot, S.; Lavigne, J.; Marois, A. [Defence Research Establishment Valcartier, Courcelette, PQ (Canada); Hawari, J.; Jones, A.M.; Rho, D. [National Research Council of Canada, Ottawa, ON (Canada)

    1995-06-01

    Within the framework of an R and D project on bioremediation of soils contaminated with energetic compounds, the biodegradation of energetic products such as hexogen (RDX), trinitrotoluene (TNT), nitrocellulose (NC) and glycidyl azide polymer (GAP) is under study. Microcosm assays must be performed with radioactive carbon-14 labelled products in order to follow the biodegradation process. {sup 14}C-RDX was prepared by nitration of hexamethylenetetramine (HMTA) according to the Hale process. {sup 14}C-ring and methyl labelled TNTs synthesized according to the Dorey and Carper procedure. {sup 14}C-cellulose was synthesized from {sup 14}C-glucose by Acetobacter xylinum. Nitration of the {sup 14}C-cellulose yielded {sup 14}C-nitrocellulose. {sup 14}C-glycidyl azide polymer was obtained by polymerization and azidation of {sup 14}C-epichlorohydrin (ECH) which was synthesized from {sup 14}C-glycerol. Hydrochlorination of {sup 14}C-glycerol and epoxidation of the resulting {sup 14}C-1,3-dichloro 2-propanol yielded {sup 14}C-ECH. The syntheses of these {sup 14}C-labelled explosives are described in this paper. (Author).

  6. Optimal Conditions for Continuous Immobilization of Pseudozyma hubeiensis (Strain HB85A Lipase by Adsorption in a Packed-Bed Reactor by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Roberta Bussamara

    2012-01-01

    Full Text Available This study aimed to develop an optimal continuous process for lipase immobilization in a bed reactor in order to investigate the possibility of large-scale production. An extracellular lipase of Pseudozyma hubeiensis (strain HB85A was immobilized by adsorption onto a polystyrene-divinylbenzene support. Furthermore, response surface methodology (RSM was employed to optimize enzyme immobilization and evaluate the optimum temperature and pH for free and immobilized enzyme. The optimal immobilization conditions observed were 150 min incubation time, pH 4.76, and an enzyme/support ratio of 1282 U/g support. Optimal activity temperature for free and immobilized enzyme was found to be 68°C and 52°C, respectively. Optimal activity pH for free and immobilized lipase was pH 4.6 and 6.0, respectively. Lipase immobilization resulted in improved enzyme stability in the presence of nonionic detergents, at high temperatures, at acidic and neutral pH, and at high concentrations of organic solvents such as 2-propanol, methanol, and acetone.

  7. Oxidation, Reduction, and Condensation of Alcohols over (MO3)3 (M=Mo, W) Nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Zongtang; Li, Zhenjun; Kelley, Matthew S.; Kay, Bruce D.; Li, Shenggang; Hennigan, Jamie M.; Rousseau, Roger J.; Dohnalek, Zdenek; Dixon, David A.

    2014-10-02

    The reactions of deuterated methanol, ethanol, 1-propanol, 1-butanol, 2-propanol, 2-butanol and t-butanol over cyclic (MO3)3 (M = Mo, W) clusters were studied experimentally with temperature programmed desorption (TPD) and theoretically with coupled cluster CCSD(T) theory and density functional theory. The reactions of two alcohols per M3O9 cluster are required to provide agreement with experiment for D2O release, dehydrogenation and dehydration. The reaction begins with the elimination of water by proton transfers and forms an intermediate dialkoxy species which can undergo further reaction. Dehydration proceeds by a β hydrogen transfer to a terminal M=O. Dehydrogenation takes place via an α hydrogen transfer to an adjacent MoVI = O atom or a WVI metal center with redox involved for M = Mo and no redox for M = W. The two channels have comparable activation energies. H/D exchange to produce alcohols can take place after olefin is released or via the dialkoxy species depending on the alcohol and the cluster. The Lewis acidity of the metal center with WVI being larger than MoVI results in the increased reactivity of W3O9 over Mo3O9 for dehydrogenation and dehydration.

  8. Sustained release of vancomycin from novel biodegradable nanofiber-loaded vascular prosthetic grafts: in vitro and in vivo study

    Directory of Open Access Journals (Sweden)

    Liu KS

    2015-01-01

    Full Text Available Kuo-Sheng Liu,1 Cheng-Hung Lee,2 Yi-Chuan Wang,3 Shih-Jung Liu3 1Department of Thoracic and Cardiovascular Surgery, Chang Gung Memorial Hospital, Linkou, Taiwan; 2Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou, Taiwan; 3Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, Taiwan Abstract: This study describes novel biodegradable, drug-eluting nanofiber-loaded vascular prosthetic grafts that provide local and sustained delivery of vancomycin to surrounding tissues. Biodegradable nanofibers were prepared by first dissolving poly(D,L-lactide-co-glycolide and vancomycin in 1,1,1,3,3,3-hexafluoro-2-propanol. The solution was then electrospun into nanofibers onto the surface of vascular prostheses. The in vitro release rates of the pharmaceutical from the nanofiber-loaded prostheses was characterized using an elution method and a high-performance liquid chromatography assay. Experimental results indicated that the drug-eluting prosthetic grafts released high concentrations of vancomycin in vitro (well above the minimum inhibitory concentration for more than 30 days. In addition, the in vivo release behavior of the drug-eluting grafts implanted in the subcutaneous pocket of rabbits was also documented. The drug-eluting grafts developed in this work have potential applications in assisting the treatment of vascular prosthesis infection and resisting reinfection when an infected graft is to be exchanged. Keywords: drug-eluting prosthetic graft, vascular prosthesis infection, release characteristics

  9. Desalination of aqueous solutions by LTA and MFI zeolite membranes using pervaporation method

    Directory of Open Access Journals (Sweden)

    A. Malekpour

    2011-12-01

    Full Text Available LTA and MFI zeolite membranes were hydrothermally grown on the surface of an α-alumina porous support. The synthesized membranes were used for removal of cationic and anionic species from aqueous solutions by the pervaporation method. The perfection of the membranes was improved by employing the multi-stage synthesis method. The membranes were characterized by XRD, SEM and IR methods. The membranes were initially evaluated by the pervaporation separation of water from aqueous 2-propanol mixtures. The separation factors obtained were 7081 and 105 for NaA and ZSM-5 membranes, respectively. The ability of membranes for desalination of some aqueous solutions containing I-, Cs+ and Sr2+ ions was examined in various conditions. These ionic species were chosen because of their importance in the nuclear sciences. Both membranes effectively removed (more than 99 wt% I-, Cs+ and Sr2+ from their singlesalt solutions (0.001mol dm-3 over a temperature range of 298-338 K. The effects of parameters such as time and temperature on the separation factors and fluxes were investigated. This work shows that, due to their excellent chemical, thermal and mechanical stability, the zeolitic membranes are useful for desalination of aqueous solutions and treating saline wastewaters by pervaporation. Therefore, this method has the ability to desalinate harsh environment solutions involving strong solvent and radioactive components.

  10. Production of hydrogen by steam reforming of C3 organics over Pd-Cu/{gamma}-Al{sub 2}O{sub 3} catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Resini, Carlo; Berardinelli, Silvia; Busca, Guido [Dipartimento di Ingegneria Chimica e Processo, Universita di Genova, P.le J.F. Kennedy, 1, 16129 Genova (Italy); Arrighi, Laura; Riani, Paola; Marazza, Rinaldo [Dipartimento di Chimica e Chimica Industriale, Universita di Genova, Via Dodecaneso 31, 16146 Genova (Italy); Concepcion Herrera Delgado, Maria; Angeles Larrubia Vargas, Maria; Alemany, Luis J. [Departamento de Ingenieria Quimica, Universidad de Malaga, 29071 Malaga (Spain)

    2006-01-15

    The conversion of the C3 organics propane, propene, isopropanol and acetone in auto-thermal and endothermic steam reforming conditions has been investigated over a Pd-Cu/Al{sub 2}O{sub 3} catalyst in a flow reactor. Although several reactions may occur at lower temperatures (like dehydrogenation, oxidative dehydrogenation, dehydration and combustion), steam reforming of 2-propanol, acetone and propane only start above 850K and with incomplete selectivity. Cracking and methanation lower the selectivity to CO{sub x} and hydrogen. The C-C bond breaking step is considered to be rate determining. The presence of an oxygenated functional group is consequently not useful to lower reaction temperature, although the use of the alcohol and the ketone may be interesting because of the renewable nature of these reactants. Steam reforming of propene starts at significantly lower temperature (600-700K) and is by far the most selective to CO{sub x} and hydrogen over our catalyst. (author)

  11. Extraction and recovery of 2-butoxyethanol from aqueous phases containing high saline concentration

    Directory of Open Access Journals (Sweden)

    Katherine E. Manz

    2016-09-01

    Full Text Available Ethylene glycol monobutyl ether (EGBE, also known as 2-butoxyethanol (2-BE, has been identified as a contaminant in hydraulic fracturing fluids. In order to determine the presence of 2-BE in hydraulic fracturing chemical additives, a reliable method for recovering 2-BE from aqueous phases by liquid-liquid extraction combined with gas chromatography/mass spectrometry (GC/MS was established. The liquid-liquid extraction method was applied to samples matrices containing various amounts of salt. Using methylene chloride for liquid-liquid extraction in a sample to solvent ratio of 1:3, ≥99% 2-BE recovery may be achieved with less than 5% standard error. The limit of detection was determined to be 0.957 mg L−1 2-BE. Accuracy was determined to be 2.58% and precision was determined using the coefficient of variation, which was 3.5%. The method was used to recover 2-BE in a hydraulic fracturing chemical additive called Revert Flow and to quantify the weight percent of 2-BE in the chemical additive. Weight percent of two additional components of Revert Flow, D-limonene and 1-butoxy-2-propanol, were also determined. We also used the method to determine the abiotic of 2-BE in water, which was 5.55 days. The persistence of 2-BE in hydraulic fracturing fluid was also investigated and determined that 2-BE is more persistent in this environment.

  12. Chromatographic analyses of fatty acid methyl esters by HPLC-UV and GC-FID

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Myller S.; Pinho, David M.M.; Suarez, Paulo A.Z., E-mail: psuarez@unb.br [Laboratorio de Materiais e Combustiveis, Instituto de Quimica, Universidade de Brasilia, DF (Brazil); Mendonca, Marcio A. [Faculdade de Agronomia e Medicina Veterinaria, Universidade de Brasilia, DF (Brazil); Resck, Ines S. [Laboratorio de Ressonancia Magnetica Nuclear, Universidade de Brasilia, DF (Brazil)

    2012-04-15

    An analytical method using high performance liquid chromatography with UV detection (HPLC-UV) (method A) was used for simultaneous determination of total amounts of triacylglycerides, diacylglycerides, monoacylglycerides and fatty acid methyl esters in alcoholysis of different oil (cotton, canola, sunflower, corn and soybean) samples. Analyses were carried out at 40 deg C for 20 min using a gradient of methanol (MeOH) and 2-propanol-hexane 5:4 (v/v) (PrHex): 100% of MeOH in 0 min, 50% of MeOH and 50% of PrHex in 10 min maintained with isocratic elution for 10 min. Another HPLC-UV method (method B) with acetonitrile isocratic elution for 34 min was used to determine the fatty acid composition of oils analyzing their methyl ester derivatives. Contents were determined with satisfactory repeatability (relative standard deviation, RSD < 3%), linearity (r{sup 2} > 0.99) and sensitivity (limit of quantification). Method B was compared with an official gas chromatographic method with flame ionization detection (GC-FID) from American Oil Chemists' Society (AOCS) in the determination of fatty acid methyl esters (FAME) in biodiesel real samples. (author)

  13. Deacidification of oils and fats of biological origine by aqueous solutions of tertiary amines*

    Directory of Open Access Journals (Sweden)

    Peter Siegfried

    2001-01-01

    Full Text Available Deacidification of triacylglycerols by extraction is investigated using aqueous solutions of amines as extractants. Tertiary amines with boiling points ranging between 100° and 170°C, such as 2-methylamino-diethanol, 2-dimethylamino-ethanol, 4-methylmorpholine, 1-dimethylamino-2-propanol etc. were found to be suitable substances. Especially the deacidification by aqueous solutions of 2-dimethylamino-ethanol (DMAE was amply investigated as it is used as an active agent in remedies. Amazingly gelatinous soap stocks are not formed, when the concentration of DMAE exceeds 20% if the free fatty acid content of the oil is below 15%. Two liquid phases are formed in systems composed of triacylglyceroles and aqueous solutions containing 20 to 80% DMAE. Palm oil containing 4.3 wt.% free fatty acids was mixed with an equal amount of an aqueous solution of 30 wt.% DMAE at 60°C. In equilibrium an extract containing 86 wt.% free fatty acids (solvents deducted and a raffinate of 0.09 wt.% free fatty acids are obtained. Loss of neutral oil being 0.7 wt.%.

  14. Case study of the sonochemical decolouration of textile azo dye Reactive Black 5

    Energy Technology Data Exchange (ETDEWEB)

    Vajnhandl, Simona [University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, 2000 Maribor (Slovenia)]. E-mail: simona.vajnhandl@uni-mb.si; Le Marechal, Alenka Majcen [University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, 2000 Maribor (Slovenia)

    2007-03-06

    The decolouration and mineralization of reactive dye C.I. Reactive Black 5, a well-known representative of non-biodegradable azo dyes, by means of ultrasonic irradiation at 20, 279 and 817 kHz has been investigated with emphasis on the effect of various parameters on decolouration and degradation efficiency. Characterization of the used ultrasound systems was performed using calorimetric measurements and oxidative species monitoring using Fricke and iodine dosimeter. Experiments were carried out with low frequency probe type, and a high-frequency plate type transducer at 50, 100 and 150 W of acoustic power and within the 5-300 mg/L initial dye concentration range. Decolouration, as well as radical production, increased with increasing frequency, acoustic power, and irradiation time. Any increase in initial dye concentration results in decreased decolouration rates. Sonochemical decolouration was substantially depressed by the addition of 2-methyl-2-propanol as a radical scavenger, which suggests radical-induced reactions in the solution. Acute toxicity to marine bacteria Vibrio fischeri was tested before and after ultrasound irradiation. Under the conditions employed in this study, no toxic compounds were detected after 6 h of irradiation. Mineralization of the dye was followed by TOC measurements. Relatively low degradation efficiency (50% after 6 h of treatment) indicates that ultrasound is rather inefficient in overall degradation, when used alone.

  15. Crystallization and preliminary characterization of three different crystal forms of human saposin C heterologously expressed in Pichia pastoris

    Energy Technology Data Exchange (ETDEWEB)

    Schultz-Heienbrok, Robert [Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin (Germany); Remmel, Natascha; Klingenstein, R. [Kekule-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn (Germany); Rossocha, Maksim [Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin (Germany); Sandhoff, Konrad [Kekule-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn (Germany); Saenger, Wolfram [Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin (Germany); Maier, Timm, E-mail: timm.maier@mol.biol.ethz.ch [Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin (Germany); Institute for Molecular Biology and Biophysics, Swiss Federal Institute of Technology, ETH Zürich (Switzerland)

    2006-02-01

    Three different crystal forms were obtained of human saposin C. The structures could not be determined by molecular replacement using known solution structures of the protein as search models, supporting the notion of a highly flexible protein. The amphiphilic saposin proteins (A, B, C and D) act at the lipid–water interface in lysosomes, mediating the hydrolysis of membrane building blocks by water-soluble exohydrolases. Human saposin C activates glucocerebrosidase and β-galactosylceramidase. The protein has been expressed in Pichia pastoris, purified and crystallized in three different crystal forms, diffracting to a maximum resolution of 2.5 Å. Hexagonal crystals grew from 2-propanol-containing solution and contain a single molecule in the asymmetric unit according to the Matthews coefficient. Orthorhombic and tetragonal crystals were both obtained with pentaerythritol ethoxylate and are predicted to contain two molecules in the asymmetric unit. Attempts to determine the respective crystal structures by molecular replacement using either the known NMR structure of human saposin C or a related crystal structure as search models have so far failed. The failure of the molecular-replacement method is attributed to conformational changes of the protein, which are known to be required for its biological activity. Crystal structures of human saposin C therefore might be the key to mapping out the conformational trajectory of saposin-like proteins.

  16. Study on synthesis of new dinuclear copper macrocyclic complex by template reaction involving lead ion as templating agent%模板法合成大环单核铅及双核铜(Ⅱ)配合物

    Institute of Scientific and Technical Information of China (English)

    王小波; 姜治平; 候波涛; 胡学雷; 潘志权

    2011-01-01

    采用Pb2+作为模板离子,以2,6-二甲酰基对甲苯酚与2-羟基-1,3-丙二胺为原料通过[2+2]缩合反应,得到单核铅配合物[Pb(H2L)](ClO4)2(H2L为中性大环配体),进一步通过金属置换反应合成了一个新的希夫碱大环双核铜(Ⅱ)配合物[Cu2L](ClO4)2,并对中间体大环单核铅配合物及其双核铜(Ⅱ)配合物的结构进行了表征.%A new dinuclear copper macrocyclic complex was synthesized by metal transferred reaction of the mononuclear lead complex as the precursor which was obtained based on the [2+2]condensation between 2,6-diacetyl-4-methylphenol and 1,3-diamino- 2-propanol in the presence of Pb2+ ion.Both structure of two complexes were characterized by several methods.

  17. Nanomaterials for the cleaning and pH adjustment of vegetable-tanned leather

    Science.gov (United States)

    Baglioni, Michele; Bartoletti, Angelica; Bozec, Laurent; Chelazzi, David; Giorgi, Rodorico; Odlyha, Marianne; Pianorsi, Diletta; Poggi, Giovanna; Baglioni, Piero

    2016-02-01

    Leather artifacts in historical collections and archives are often contaminated by physical changes such as soiling, which alter their appearance and readability, and by chemical changes which occur on aging and give rise to excessive proportion of acids that promote hydrolysis of collagen, eventually leading to gelatinization and loss of mechanical properties. However, both cleaning and pH adjustment of vegetable-tanned leather pose a great challenge for conservators, owing to the sensitivity of these materials to the action of solvents, especially water-based formulations and alkaline chemicals. In this study, the cleaning of historical leather samples was optimized by confining an oil-in-water nanostructured fluid in a highly retentive chemical hydrogel, which allows the controlled release of the cleaning fluid on sensitive surfaces. The chemical gel exhibits optimal viscoelasticity, which facilitates its removal after the application without leaving residues on the object. Nanoparticles of calcium hydroxide and lactate, dispersed in 2-propanol, were used to adjust the pH up to the natural value of leather, preventing too high alkalinity which causes swelling of fibers and denaturation of the collagen. The treated samples were characterized using scanning electron microscopy, controlled environment dynamic mechanical analysis, and infrared spectroscopy. The analytical assessment validated the use of tools derived from colloid and materials science for the preservation of collagen-based artifacts.

  18. Microemulsion system for topical delivery of thai mango seed kernel extract: development, physicochemical characterisation and ex vivo skin permeation studies.

    Science.gov (United States)

    Leanpolchareanchai, Jiraporn; Padois, Karine; Falson, Françoise; Bavovada, Rapepol; Pithayanukul, Pimolpan

    2014-10-24

    A microemulsion system containing Thai mango seed kernel extract (MSKE, cultivar "Fahlun") was developed and characterised for the purpose of topical skin delivery. The MSKE-loaded microemulsions were prepared by using the spontaneous emulsification method. Isopropyl myristate (IPM) was selected as the oil phase. A polyoxyethylene sorbitan monooleate and sorbitan monododecanoate (1:1, w/w) system was used as the surfactant phase; an aqueous mixture of different cosurfactants (absolute ethanol, 96.3% v/v ethanol, 1-propanol, 2-propanol or 1,2-propanediol) at a weight ratio of 1:1 was used as the aqueous phase. Among the cosurfactants studied, the 1-propanol aqueous mixture had the largest microemulsion region (48.93%) in the pseudo-ternary phase diagram. Microemulsions containing 1% MSKE demonstrated good physicochemical stability during a six-month study period at 25 ± 2 °C/60% ± 5% RH. The ex vivo skin permeation study demonstrated that the microemulsions exhibited a potent skin enhancement effect allowing MSKE to penetrate skin layers up to 60-fold higher compared with the control. Neither skin irritation nor skin corrosion was observed in ex vivo studies. The present study revealed that IPM-based microemulsion systems may be promising carriers to enhance skin penetration and delivering MSKE for topical treatment.

  19. Enantioselective HPLC resolution of synthetic intermediates of armodafinil and related substances.

    Science.gov (United States)

    Nageswara Rao, Ramisetti; Shinde, Dhananjay D; Kumar Talluri, Murali V N

    2008-04-01

    Armodafinil is a unique psychostimulant recently approved by the US Food and Drug Administration for the treatment of narcolepsy. The chromatographic resolution of its chiral intermediates including related substances in the total synthesis of armodafinil was studied on polysaccharide-based stationary phases, viz. cellulose tris-(3,5-dimethylphenylcarbamate) (Chiralcel OD-H) and amylose tris-(3,5-dimethylphenylcarbamate) (Chiralpak AD-H) by HPLC. The effects of 1-propanol, 2-propanol, ethanol, and trifluoroacetic acid added to the mobile phase and of column temperature on resolution were studied. A good separation was achieved on cellulose-based Chiralcel OD-H column compared to amylose-based Chiralpak AD-H. The effects of structural features of the solutes and solvents on discrimination between the enantiomers were examined. Baseline separation with R(s) >1.38 was obtained using a mobile phase containing n-hexane-ethanol-TFA (75:25:0.15 v/v/v). Detection was carried out at 225 nm with photodiode array detector while identification of enantiomers was accomplished by a polarimetric detector connected in series. The method was found to be suitable not only for process development of armodafinil but also for determination of the enantiomeric purity of bulk drugs and pharmaceuticals.

  20. Decellularized omentum as novel biologic scaffold for reconstructive surgery and regenerative medicine

    Directory of Open Access Journals (Sweden)

    A. Porzionato

    2013-01-01

    Full Text Available Homologous tissues, such as adipose tissue, may be an interesting source of acellular scaffolds, maintaining a complex physiological three-dimensional (3D structure, to be recellularized with autologous cells. The aim of the present work is to evaluate the possibility of obtaining homologous acellular scaffolds from decellularization of the omentum, which is known to have a complex vascular network. Adult rat and human omenta were treated with an adapted decellularization protocol involving mechanical rupture (freeze-thaw cycles, enzymatic digestion (trypsin, lipase, deoxyribonuclease, ribonuclease and lipid extraction (2-propanol. Histological staining confirmed the effectiveness of decellularization, resulting in cell-free scaffolds with no residual cells in the matrix. The complex 3D networks of collagen (azan-Mallory, elastic fibers (Van Gieson, reticular fibers and glycosaminoglycans (PAS were maintained, whereas Oil Red and Sudan stains showed the loss of lipids in the decellularized tissue. The vascular structures in the tissue were still visible, with preservation of collagen and elastic wall components and loss of endothelial (anti-CD31 and -CD34 immunohistochemistry and smooth muscle (anti-alpha smooth muscle actin cells. Fat-rich and well vascularized omental tissue may be decellularized to obtain complex 3D scaffolds preserving tissue architecture potentially suitable for recellularization. Further analyses are necessary to verify the possibility of recolonization of the scaffold by adipose-derived stem cells in vitro and then in vivo after re-implantation, as already known for homologus implants in regenerative processes.

  1. Magnetically responsive enzyme powders

    Energy Technology Data Exchange (ETDEWEB)

    Pospiskova, Kristyna, E-mail: kristyna.pospiskova@upol.cz [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Safarik, Ivo, E-mail: ivosaf@yahoo.com [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic)

    2015-04-15

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (−20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties. - Highlights: • Cross-linked enzyme powders were prepared in various liquid media. • Insoluble enzymes were magnetized using iron oxides particles. • Magnetic iron oxides particles were prepared by microwave-assisted synthesis. • Magnetic modification was performed under low (freezing) temperature. • Cross-linked powdered trypsin and lipase can be used repeatedly for reaction.

  2. Chemically-modified polysaccharide extract derived from Leucaena leucocephala alters Raw 264.7 murine macrophage functions.

    Science.gov (United States)

    Gamal-Eldeen, Amira M; Amer, Hassan; Helmy, Wafaa A; Talaat, Roba M; Ragab, Halla

    2007-06-01

    In this study, a chemical modification of the polysaccharides extract (E) derived from Leucaena leucocephala seeds was performed to prepare C-glycosidic 2-propanol derivative (PE), and its sulphated derivative (SPE). This study aimed to characterize immunomodulatory activities of the original extract and its derivatives by exploring their effects on Raw macrophage 264.7 functions and their antioxidant activity. Our results indicated that PE was an effective radical scavenger to hydroxyl, peroxyl, and superoxide anion radicals, and SPE was a peroxyl radical scavenger. PE and SPE were found to influence the macrophage functions. Both of PE and SPE enhanced the macrophage proliferation and phagocytosis of FITC-zymosan; PE inhibited nitric oxide (NO) generation and tumor necrosis factor-alpha (TNF-alpha) secretion in lipopolysaccharide (LPS)-stimulated Raw macrophage 264.7. In contrast, SPE over-induced NO generation and TNF-alpha secretion. Moreover, PE strongly inhibited the binding affinity of FITC-LPS to Raw 264.7, as indicated by flow cytometry analysis. These findings revealed that PE may act as a potent anti-inflammatory agent; however SPE may act as an inducer of macrophage functions against pathogens.

  3. Expression, purification and preliminary crystallographic studies of human ketohexokinase.

    Science.gov (United States)

    Kozak, M; Hayward, B; Borek, D; Bonthron, D T; Jaskólski, M

    2001-04-01

    Ketohexokinase (KHK; E.C. 2.7.1.3) catalyses the (reversible) phosphorylation of fructose to fructose-1-phosphate. KHK is the first enzyme in a specialized catabolic pathway metabolizing dietary fructose to the glycolytic intermediate glyceraldehyde-3-phosphate. Mutations inactivating KHK underlie the metabolic disorder essential fructosuria. The primary structure of KHK shows no significant homology to other mammalian hexokinases. It is most similar to prokaryotic ribokinases, but catalyses a distinct phosphorylation reaction. Recombinant human KHK has been crystallized in the orthorhombic form (space group P2(1)2(1)2 or P2(1)2(1)2(1)). Single crystals of this polymorph suitable for X-ray diffraction have been obtained by vapour diffusion using 2-propanol and MPD as precipitants (pH 7.5). The crystals have unit-cell parameters a = 93.4, b = 121.5, c = 108.4 A. Diffraction data were collected to 4.3 A resolution. The asymmetric unit contains four protein molecules.

  4. Enhanced bioactivity of ZnO nanoparticles-an antimicrobial study

    Energy Technology Data Exchange (ETDEWEB)

    Padmavathy, Nagarajan; Vijayaraghavan, Rajagopalan [School of Science and Humanities-Materials Division, VIT University, Vellore - 632 014, Tamil Nadu (India)], E-mail: rvijayaraghavan@vit.ac.in

    2008-07-01

    In this study, we investigate the antibacterial activity of ZnO nanoparticles with various particle sizes. ZnO was prepared by the base hydrolysis of zinc acetate in a 2-propanol medium and also by a precipitation method using Zn(NO{sub 3}){sub 2} and NaOH. The products were characterized by x-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. Bacteriological tests such as minimum inhibitory concentration (MIC) and disk diffusion were performed in Luria-Bertani and nutrient agar media on solid agar plates and in liquid broth systems using different concentrations of ZnO by a standard microbial method for the first time. Our bacteriological study showed the enhanced biocidal activity of ZnO nanoparticles compared with bulk ZnO in repeated experiments. This demonstrated that the bactericidal efficacy of ZnO nanoparticles increases with decreasing particle size. It is proposed that both the abrasiveness and the surface oxygen species of ZnO nanoparticles promote the biocidal properties of ZnO nanoparticles.

  5. Enhanced bioactivity of ZnO nanoparticles—an antimicrobial study

    Directory of Open Access Journals (Sweden)

    Nagarajan Padmavathy and Rajagopalan Vijayaraghavan

    2008-01-01

    Full Text Available In this study, we investigate the antibacterial activity of ZnO nanoparticles with various particle sizes. ZnO was prepared by the base hydrolysis of zinc acetate in a 2-propanol medium and also by a precipitation method using Zn(NO32 and NaOH. The products were characterized by x-ray diffraction (XRD analysis, transmission electron microscopy (TEM and photoluminescence (PL spectroscopy. Bacteriological tests such as minimum inhibitory concentration (MIC and disk diffusion were performed in Luria-Bertani and nutrient agar media on solid agar plates and in liquid broth systems using different concentrations of ZnO by a standard microbial method for the first time. Our bacteriological study showed the enhanced biocidal activity of ZnO nanoparticles compared with bulk ZnO in repeated experiments. This demonstrated that the bactericidal efficacy of ZnO nanoparticles increases with decreasing particle size. It is proposed that both the abrasiveness and the surface oxygen species of ZnO nanoparticles promote the biocidal properties of ZnO nanoparticles.

  6. Fabrication and Intermolecular Interactions of Silk Fibroin/Hydroxybutyl Chitosan Blended Nanofibers

    Directory of Open Access Journals (Sweden)

    Xiu-Mei Mo

    2011-03-01

    Full Text Available The native extracellular matrix (ECM is composed of a cross-linked porous network of multifibril collagens and glycosaminoglycans. Nanofibrous scaffolds of silk fibroin (SF and hydroxybutyl chitosan (HBC blends were fabricated using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP and trifluoroacetic acid (TFA as solvents to biomimic the native ECM via electrospinning. Scanning electronic microscope (SEM showed that relatively uniform nanofibers could be obtained when 12% SF was blended with 6% HBC at the weight ratio of 50:50. Meanwhile, the average nanofibrous diameter increased when the content of HBC in SF/HBC blends was raised from 20% to 100%. Fourier transform infrared spectra (FTIR and 13C nuclear magnetic resonance (NMR showed SF and HBC molecules existed in hydrogen bonding interactions but HBC did not induce conformation of SF transforming from random coil form to β-sheet structure. X-ray diffraction (XRD confirmed the different structure of SF/HBC blended nanofibers from both SF and HBC. Thermogravimetry-Differential thermogravimetry (TG-DTG results demonstrated that the thermal stability of SF/HBC blend nanofibrous scaffolds was improved. The results indicated that the rearrangement of HBC and SF molecular chain formed a new structure due to stronger hydrogen bonding between SF and HBC. These electrospun SF/HBC blended nanofibers may provide an ideal tissue engineering scaffold and wound dressing.

  7. Apatite coating of electrospun PLGA fibers using a PVA vehicle system carrying calcium ions.

    Science.gov (United States)

    Kim, In Ae; Rhee, Sang-Hoon

    2010-01-01

    A novel method to coat electrospun poly(D,L-lactic-co-glycolic acid) (PLGA) fiber surfaces evenly and efficiently with low-crystalline carbonate apatite crystals using a poly(vinyl alcohol) (PVA) vehicle system carrying calcium ions was presented. A non-woven PLGA fabric was prepared by electrospinning: a 10 wt% PLGA solution was prepared using 1,1,3,3-hexafluoro-2-propanol as a solvent and electrospun under a electrical field of 1 kV/cm using a syringe pump with a flowing rate of 3 ml/h. The non-woven PLGA fabric, 12 mm in diameter and 1 mm in thickness, was cut and then coated with a PVA solution containing calcium chloride dihydrate (specimen PPC). As controls, pure non-woven PLGA fabric (specimen P) and fabric coated with a calcium chloride dihydrate solution without PVA (specimen PC) were also prepared. Three specimens were exposed to simulated body fluid for 1 week and this exposure led to form uniform and complete apatite coating layer on the fiber surfaces of specimen PPC. However, no apatite had formed to the fiber surfaces of specimen P and only inhomogeneous coating occurred on the fiber surfaces of specimen PC. These results were explained in terms of the calcium chelating and adhesive properties of PVA vehicle system. The practical implication of the results is that this method provides a simple but efficient technique for coating the fiber surface of an initially non-bioactive material with low-crystalline carbonate apatite.

  8. Effect of water miscible organic solvents on p-nitrophenol hydroxylase (CYP2E1 activity in rat liver microsomes

    Directory of Open Access Journals (Sweden)

    Pranali G Patil

    2015-01-01

    Full Text Available Organic solvents used for solubilization of the substrates/NCEs are known to affect the activity of cytochrome P450 enzymes. Further, this effect varies with the solvents used, the substrates and CYP450 isoforms in question. In the present study, we have investigated the effect of ten commonly used water miscible organic solvents (methanol, ethanol, 1-propanol, 2-propanol, acetonitrile, acetone, dimethyl sulphoxide, N,N-dimethyl formamide, dioxane and polyethylene glycol 400 on p-nitrophenol hydroxylase activity at 0, 0.1, 0.25, 0.5, 0.75 and 1% v/v concentration in rat liver microsomes. All the solvents studied showed concentration dependent inhibition of the p-nitrophenol hydroxylase activity except acetonitrile which showed activation of the activity at concentration range studied. Out of ten solvents studied, dioxane was found to be the most inhibitory solvent (inhibition >90% at 0.25% v/v concentration. Overall, solvents like dimethyl sulphoxide, dimethyl formamide and dioxane appeared to be unsuitable for characterizing p-nitrophenol hydroxylase (CYP2E1-mediated reactions due to a high degree of inhibition. On the other hand, methanol and acetonitrile at concentrations <0.5% v/v appeared to be appropriate solvents for substrate solubilization while evaluating CYP2E1-mediated catalysis. The results of this study imply that caution should be exercised while choosing solvents for dissolution of substrate during enzyme studies in liver microsomes.

  9. Simultaneous determination of neonicotinoid insecticides in human serum and urine using diatomaceous earth-assisted extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Yamamuro, Tadashi; Ohta, Hikoto; Aoyama, Mika; Watanabe, Daisuke

    2014-10-15

    A rapid and sensitive analytical method was developed for simultaneous determination of eight neonicotinoid insecticides (acetamiprid, clothianidin, dinotefuran, flonicamid, imidacloprid, nitenpyram, thiacloprid and thiamethoxam) and three specific metabolites of acetamiprid (N-desmethylacetamiprid, 5-(N-acetyl-N-methylaminomethyl)-2-chloropyridine and 5-(N-acetylaminomethyl)-2-chloropyridine) in human serum and urine. A diatomaceous earth-assisted extraction using Extrelut NT3 column with chloroform/2-propanol (3:1, v/v) as eluent was selected for the single step cleanup procedure for all the target compounds. Qualitative and quantitative analyses were conducted by liquid chromatography-tandem mass spectrometry with multiple reaction monitoring mode. The limits of detection and the limits of quantification of eleven compounds were in the ranges of 0.1-0.2ng/mL and 0.5-10ng/mL for serum, 0.1-1ng/mL and 1-10ng/mL for urine, respectively. The extraction recoveries were between 80.9% and 101.8% for serum samples, 91.9% and 106% for urine samples. The intra-day RSDs and the inter-day RSDs were less than 11.5% and 13.2% for serum, less than 8.3% and 8.8% for urine. The proposed procedure will be suitable for forensic investigations of human poisoning cases with neonicotinoid insecticides. This is the first report of simultaneous determination of eight neonicotinoids in serum and urine samples.

  10. Cu/MgAl(2)O(4) as bifunctional catalyst for aldol condensation of 5-hydroxymethylfurfural and selective transfer hydrogenation.

    Science.gov (United States)

    Pupovac, Kristina; Palkovits, Regina

    2013-11-01

    Copper supported on mesoporous magnesium aluminate has been prepared as noble-metal-free solid catalyst for aldol condensation of 5-hydroxymethylfurfural with acetone, followed by hydrogenation of the aldol condensation products. The investigated mesoporous spinels possess high activity as solid-base catalysts. Magnesium aluminate exhibits superior activity compared to zinc and cobalt-based aluminates, reaching full conversion and up to 81 % yield of the 1:1 aldol product. The high activity can be correlated to a higher concentration of basic surface sites on magnesium aluminate. Applying continuous regeneration, the catalysts can be recycled without loss of activity. Focusing on the subsequent hydrogenation of aldol condensation products, Cu/MgAl2 O4 allows a selective hydrogenation and CO bond cleavage, delivering 3-hydroxybutyl-5-methylfuran as the main product with up to 84 % selectivity avoiding ring saturation. Analysis of the hydrogenation activity reveals that the reaction proceeds in the following order: CC>CO>CO cleavage>ring hydrogenation. Comparable activity and selectivity can be also achieved utilizing 2-propanol as solvent in the transfer hydrogenation, providing the possibility for partial recycling of acetone and optimization of the hydrogen management.

  11. Outgrowth inhibition of Clostridium beijerinckii spores by a bacteriocin-producing lactic culture in ovine milk cheese.

    Science.gov (United States)

    Garde, Sonia; Avila, Marta; Arias, Ramón; Gaya, Pilar; Nuñez, Manuel

    2011-10-17

    In the manufacture of model cheeses, ovine milk was deliberately contaminated with spores of Clostridium beijerinckii INIA 63, a wild isolate from Manchego cheese with late blowing defect, and inoculated with nisin- and lacticin 481-producing Lactococcus lactis subsp. lactis INIA 415 as starter, to test its potential to prevent the late blowing defect, or with L. lactis subsp. lactis INIA 415-2, a spontaneous mutant not producing bacteriocins. Cheeses made individually with the lactococcal strains, without clostridial spores, served as controls. Cheese made with clostridial spores and L. lactis subsp. lactis INIA 415-2 showed late blowing defect after 120days of ripening. Spoilt cheese also showed lower concentrations of lactic acid, and higher levels of acetic, propionic and butyric acids, and of other volatile compounds such as 2-propanol and 1-butanol, than control cheese. In addition, cheese made with the bacteriocin producer did not show any late blowing symptoms, despite its spore counts similar to those of blown cheese, pointing to outgrowth inhibition of C. beijerinckii spores by bacteriocins. Besides, cheese made with the bacteriocin producer showed similar concentrations of lactic acid and volatile compounds than control cheese. Inclusion of L. lactis subsp. lactis INIA 415 in starter cultures seems a feasible method to prevent late blowing defect in cheese without altering its sensory characteristics.

  12. Determination of volatile fractions in raw milk and ripened cheese by means of GC-MS. Results of a survey performed in the marginal area between Italy and Slovenia

    Directory of Open Access Journals (Sweden)

    Bruno Stefanon

    2010-01-01

    Full Text Available The volatile fractions of milk and their evolution in ripened cheese were studied using purge and trap extraction and gas chromatography-mass spectrometry analysis (GC-MS. Eighteen samples of raw milk and cheese ripened for 70 days were collected in 2 consecutive years from dairy farms located in the border area between Italy and Slovenia. Twenty one volatile compounds not detected in the fresh milk used for cheese manufacturing, belonging mainly to the class of esters and alcohols, were found, while 8 compounds detected in milk were not found in cheese after 70 days of ripening. In cheese the majority of compounds increased significantly, even though the variations differed between the classes of volatile compounds. Concentration of alcohols, in particular ethanol, 1-propanol, 2-propanol, 3-methyl-1-butanol and 2-pentanol, increased considerably, while the content of ketones and terpenes was characterized by a significant, although small, rise that was largely related to a quantitative variation of only few compounds. Also esters, despite the high number of volatile compounds of new formation, showed a lower increase of concentration than that observed for the alcohols. Concentration of aldehydes, hydrocarbons and sulphur compounds remained unchanged, despite relevant variations involving the individual chemical compounds. Significant differences were also observed between the dairy product of the two countries, mainly for the concentration of volatile compounds belonging to the classes of alcohols, ketones and esters.

  13. Alcohol-induced structural transitions in the acid-denatured Bacillus licheniformis α-amylase

    Directory of Open Access Journals (Sweden)

    Adyani Azizah Abd Halim

    2017-01-01

    Full Text Available Alcohol-induced structural changes in the acid-denatured Bacillus licheniformis α-amylase (BLA at pH 2.0 were studied by far-ultra violet circular dichroism, intrinsic, three-dimensional and 8-anilino-1-naphthalene sulfonic acid (ANS fluorescence, acrylamide quenching and thermal denaturation. All the alcohols used in this study produced partial refolding in the acid-denatured BLA as evident from the increased mean residue ellipticity at 222 nm, increased intrinsic fluorescence and decreased ANS fluorescence. The order of effectiveness of these alcohols to induce a partially folded state of BLA was found to be: 2,2,2-trifluoroethanol/tert-butanol > 1-propanol/2-propanol > 2-chloroethanol > ethanol > methanol. Three-dimensional fluorescence and acrylamide quenching results obtained in the presence of 5.5 M tert-butanol also suggested formation of a partially folded state in the acid-denatured BLA. However, 5.5 M tert-butanol-induced state of BLA showed a non-cooperative thermal transition. All these results suggested formation of a partially folded state of the acid-denatured BLA in the presence of these alcohols. Furthermore, their effectiveness was found to be guided by their chain length, position of methyl groups and presence of the substituents.

  14. Molecular level water and solute transport in reverse osmosis membranes

    Science.gov (United States)

    Lueptow, Richard M.; Shen, Meng; Keten, Sinan

    2015-11-01

    The water permeability and rejection characteristics of six solutes, methanol, ethanol, 2-propanol, urea, Na+, and Cl-, were studied for a polymeric reverse osmosis (RO) membrane using non-equilibrium molecular dynamics simulations. Results indicate that water flux increases with an increasing fraction of percolated free volume in the membrane polymer structure. Solute molecules display Brownian motion and hop from pore to pore as they pass through the membrane. The solute rejection depends on both the size of the solute molecule and the chemical interaction of the solute with water and the membrane. When the open spaces in the polymeric structure are such that solutes have to shed at least one water molecule from their solvation shell to pass through the membrane molecular structure, the water-solute pair interaction energy governs solute rejection. Organic solutes more easily shed water molecules than ions to more readily pass through the membrane. Hydrogen-bonding sites for molecules like urea also lead to a higher rejection. These findings underline the importance of the solute's solvation shell and solute-water-membrane chemistry in solute transport and rejection in RO membranes. Funded by the Institute for Sustainability and Energy at Northwestern with computing resources from XSEDE (NSF grant ACI-1053575).

  15. High catalytic activity of magnetic CuFe2O4/graphene oxide composite for the degradation of organic dyes under visible light irradiation

    Science.gov (United States)

    Chen, Peng; Xing, Xiang; Xie, Huifang; Sheng, Qi; Qu, Hongxia

    2016-09-01

    Magnetic CuFe2O4/graphene oxide composite (CuFe2O4/GO) has been synthesized by hydrothermal method and showed excellent visible-light-photocatalytic activity for the degradation of different dyes as Rhodamine B (RhB) and acid orange II (AO7) with no need of H2O2. The Structure and morphology were investigated by XRD, FTIR and TEM and the performance of the catalyst was systematically investigated under various experimental conditions as pH, the dosage of catalyst, dye initial concentration, etc. The dyes degradation on CuFe2O4/GO was also remained in a level in the presence of *OH2- radical scavenger (2-propanol), while it decreased in the presence of *O2- radical scavenger (benzoquinone) and h+ radical scavenger (ammonium oxalate), indicating that *O2- and h+ radicals were responsible for the dye degradation. The magnetic CuFe2O4/GO composite shows potential applications in organic dye water treatment due to its magnetically recyclability and powerful visible-light-photocatalytic activity.

  16. SÍNTESIS SELECTIVA DE BENZALDEHÍDO USANDO ZEOLITAS MODIFICADAS CON METALES DE TRANSICIÓN

    Directory of Open Access Journals (Sweden)

    Clara Saux

    2012-01-01

    Full Text Available Se estudió la oxidación selectiva de estireno para la obtención de benzaldehído sobre zeolitas ZSM-5 modificadas con diferentes metales de transición (cromo, cobalto, hierro, zinc, manganeso y cobre y utilizando peróxido de hidrógeno como oxidante. Dado que los mejores resultados se obtuvieron utilizando Cr-ZSM-5, estos materiales se estudiaron evaluando el efecto del tiempo de reacción, la masa de catalizador, la relación molar estireno/hidroperóxido, la naturaleza del solvente y la temperatura de reacción. Los mejores resultados de las condiciones evaluadas se obtuvieron trabajando con una relación molar sustrato/oxidante de 0,45 y utilizando acetonitrilo como solvente, dado su carácter aprótico y de mayor polaridad de los solventes evaluados (acetonitrilo, acetona, 2-butanol y 2-propanol. El aumento en la temperatura de reacción mostró un incremento en la conversión de estireno, el cual se desaceleró al superar los 60 oC por descomposición térmica del peróxido de hidrógeno.

  17. Can Nonpolar Polyisobutylenes be Measured by Electrospray Ionization Mass Spectrometry? Anion-Attachment Proved to be an Appropriate Method

    Science.gov (United States)

    Nagy, Lajos; Nagy, Tibor; Deák, György; Kuki, Ákos; Purgel, Mihály; Narmandakh, Mijid; Iván, Béla; Zsuga, Miklós; Kéki, Sándor

    2016-03-01

    Polyisobutylenes (PIBs) with different end-groups including chlorine, exo-olefin, hydroxyl, and methyl prepared from aliphatic and aromatic initiators were studied by electrospray ionization mass spectrometry (ESI-MS). Independently of the end-groups, presence or absence of aromatic initiator moiety, these PIB derivatives were capable of forming adduct ions with NO3 - and Cl- ions, thus allowing the direct characterization of these compounds in the negative ion mode of ESI-MS. To obtain [PIB + NO3]- and [PIB + Cl]- adduct ions with appreciable intensities, addition of polar solvents such as acetone, 2-propanol, or ethanol to the dichloromethane solution of PIBs was necessary. Furthermore, increasing both the polarity (by increasing the acetone content) and the ion-source temperature give rise to enhanced intensities for both [PIB + NO3]- and [PIB + Cl]- ions. Energy-dependent collision induced dissociation studies (CID) revealed that increasing the collision voltages resulted in the shift of the apparent molecular masses to higher ones. CID studies also showed that dissociation of the [PIB + Cl]- ions requires higher collision energy than that of [PIB + NO3]-. In addition, Density Functional Theory calculations were performed to gain insights into the nature of the interactions between the highly non-polar PIB chains and anions NO3 - and Cl- as well as to determine the zero-point corrected electronic energies for the formation of [PIB + NO3]- and [PIB + Cl]- adduct ions.

  18. Visible-light driven oxidation of gaseous aliphatic alcohols to the corresponding carbonyls via TiO2 sensitized by a perylene derivative.

    Science.gov (United States)

    Guarisco, Chiara; Palmisano, Giovanni; Calogero, Giuseppe; Ciriminna, Rosaria; Di Marco, Gaetano; Loddo, Vittorio; Pagliaro, Mario; Parrino, Francesco

    2014-10-01

    Sensitized P25 TiO2 was prepared by wet impregnation with a home-prepared perylene dye, i.e., N,N'-bis(2-(1-piperazino)ethyl)-3,4,9,10-perylene-tetracarboxylic acid diimide dichloride (PZPER). Energy levels of PZPER were found to be compatible with those of TiO2 allowing fast electron transfer. The obtained catalyst has been characterized and used in the gas-phase partial oxidation of aliphatic primary and secondary alcohols, i.e., methanol, ethanol, and 2-propanol. The reaction was carried out under cut-off (λ > 400 nm) simulated solar radiation in O2 atmosphere. The perylene derivative allowed a good absorbance of visible radiation thanks to its low optical energy gap (2.6 eV) which was evaluated by cyclic voltammetry. The optimal organic sensitizing amount was found to be 5.6 % w/w in terms of yield in carbonyl derivatives. Moreover, no change in reactivity/selectivity was observed after 10-h irradiation thus confirming the catalyst stability. Yields into formaldehyde, acetaldehyde, and acetone were 67, 70, and 96 %, respectively. No significant amounts of organic byproducts were detected but for methanol oxidation, whereas a minor amount of the substrate degraded to CO2.

  19. Automated statistical experimental design approach for rapid separation of coenzyme Q10 and identification of its biotechnological process related impurities using UHPLC and UHPLC-APCI-MS.

    Science.gov (United States)

    Talluri, Murali V N Kumar; Kalariya, Pradipbhai D; Dharavath, Shireesha; Shaikh, Naeem; Garg, Prabha; Ramisetti, Nageswara Rao; Ragampeta, Srinivas

    2016-09-01

    A novel ultra high performance liquid chromatography method development strategy was ameliorated by applying quality by design approach. The developed systematic approach was divided into five steps (i) Analytical Target Profile, (ii) Critical Quality Attributes, (iii) Risk Assessments of Critical parameters using design of experiments (screening and optimization phases), (iv) Generation of design space, and (v) Process Capability Analysis (Cp) for robustness study using Monte Carlo simulation. The complete quality-by-design-based method development was made automated and expedited by employing sub-2 μm particles column with an ultra high performance liquid chromatography system. Successful chromatographic separation of the Coenzyme Q10 from its biotechnological process related impurities was achieved on a Waters Acquity phenyl hexyl (100 mm × 2.1 mm, 1.7 μm) column with gradient elution of 10 mM ammonium acetate buffer (pH 4.0) and a mixture of acetonitrile/2-propanol (1:1) as the mobile phase. Through this study, fast and organized method development workflow was developed and robustness of the method was also demonstrated. The method was validated for specificity, linearity, accuracy, precision, and robustness in compliance to the International Conference on Harmonization, Q2 (R1) guidelines. The impurities were identified by atmospheric pressure chemical ionization-mass spectrometry technique. Further, the in silico toxicity of impurities was analyzed using TOPKAT and DEREK software.

  20. Thematic outlook. Technical outlook for the fuel-cell research network (PACo). August 8, 2002 update, no. 7; Veille thematique. La veille technique pour le reseau PACo. Actualisation du 8 aout 2002, no. 7

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-08-01

    This report brings together a compilation of abstracts of articles about some recent research works carried out in the domain of fuel cells, hydrogen production and hydrogen storage: characteristics of a PEM fuel cell submitted to a transient increase of CO concentration; perspectives of the different fuel cell technologies in transport applications; development of a portable fuel cell system for the soldier's equipment; direct 2-propanol low temperature fuel cell; a fuel cell system quasi-directly supplied with methanol and based on a mixture of electrolytic polymers; catalysis in low temperature fuel cells (part.1: the cathode stakes); manufacturing and performance of the new multi-layer cathodes for SOFCs; patent about intermediate plates for the limitation of the movement of the bolts used for the fastening of a fuel cell core; the Paul Sherrer institute is testing a zinc and synthetic gas production process that use solar energy, natural gas and zinc oxide; experimental evaluation of a combined plasma/catalyst system for the production of hydrogen from the partial oxidation of hydrocarbons; hydrogen production using a new chemo-organo-trophic bacteria: Citrobacter sp. Y19; hydrogen as energy vector: competition or complementarity with fossil fuels; hydrogen storage in general and in light monocrystalline metal hydrides in particular; the nuclear option for the production of hydrogen as energy of the future. (J.S.)

  1. Evaluation of a measurement system for Uranium electrodeposition control to radiopharmaceuticals production

    Energy Technology Data Exchange (ETDEWEB)

    Tufic Madi Filho; Adonis Marcelo Saliba Silva; Jose Patricio Nahuel Cardenas; Maria da Conceicao Costa Pereira; Valdir Maciel Lopes; Alexandre, P. S.; Diogo, F. S.; Rafael, T. P.; Vitor, O. A; Anderson, F. L.; Lucas, R. S.; Brianna, S.; Eduardo, L. C. [Nuclear and Energy Research Institute, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242 Cid Univers. CEP: 05508-000- Sao Paulo-SP, (Brazil)

    2015-07-01

    For 2016, studies by international bodies forecast a crisis in the supply of Molybdenum ({sup 99}Mo), which is the generator of {sup 99m}Tc, widely used for medical diagnoses and treatments. As a result, many countries are making efforts to prevent this crisis. Brazil is developing the Brazilian Multipurpose Reactor (RMB) project, under the responsibility of the National Nuclear Energy Commission (CNEN). The RMB is a nuclear reactor for research and production of radioisotopes used in the production of radiopharmaceuticals and radioactive sources, broadly used in industrial and research areas in Brazil. Electrodeposition of uranium is a common practice to create samples for alpha spectrometry and this methodology may be an alternative way to produce targets of low enriched uranium (LEU) to fabricate radiopharmaceuticals, as {sup 99}Mo, used for cancer diagnosis. To study the electrodeposition, a solution of 10 mM uranyl nitrate, in 2-propanol, containing uranium enriched to 2.4% in {sup 235}U, with pH = 1, was prepared and measurements with an alpha spectrometer were performed. These studies are justified by the need to produce {sup 99}Mo since, despite using molybdenum in bulk, Brazil is totally dependent on its import. In this project, we intend to obtain a process that may be technologically feasible to control the radiation targets for {sup 99}Mo production. (authors)

  2. A thermodynamic study of ketoreductase-catalyzed reactions 5. Reduction of substituted ketones in n-hexane

    Energy Technology Data Exchange (ETDEWEB)

    Tewari, Yadu B. [Biochemical Science and Analytical Chemistry Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)], E-mail: yadu.tewari@nist.gov; Vanderah, David J. [Biochemical Science and Analytical Chemistry Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)], E-mail: david.vanderah@nist.gov; Schantz, Michele M. [Biochemical Science and Analytical Chemistry Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)], E-mail: michele.schantz@nist.gov; Goldberg, Robert N. [Biochemical Science and Analytical Chemistry Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)], E-mail: robert.goldberg@nist.gov; Rozzell, J. David [Codexis, Inc., 129 N. Hill Avenue, Pasadena, CA 91106 (United States)], E-mail: david.rozzell@codexis.com; Liebman, Joel F. [Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, MD 21250 (United States)], E-mail: jliebman@umbc.edu; Hui, Raymond Wai-Man; Nissenbaum, Yitzy; Parniani, Ahmad Reza [Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, MD 21250 (United States)

    2008-04-15

    The equilibrium constants K for the ketoreductase-catalyzed reduction reactions of 1-benzyl-3-pyrrolidinone, ethyl 2-oxo-4-phenylbutyrate, ethyl 4-chloroacetoacetate, 1-benzyl-4-piperidone, and 1-benzyl-3-piperidone were measured in n-hexane at T = 298.15 K by using gas chromatography. The equilibrium constants for the reaction involving 1-benzyl-4-piperidone were also measured as a function of temperature (288.15 to 308.05) K. The calculated thermodynamic quantities for the reaction (1-benzyl-4-piperidone + 2-propanol = 1-benzyl-4-hydroxypiperidine + acetone) reaction carried out in n-hexane at T = 298.15 K are: K = (26.2 {+-} 1.7); {delta}{sub r}G{sub m}{sup 0}=-(8.10{+-}0.16)kJ.mol{sup -1}; {delta}{sub r}H{sub m}{sup 0}=-(3.44{+-}0.42)kJ.mol{sup -1}; and {delta}{sub r}S{sub m}{sup 0}=(15.6{+-}1.4)J.K{sup -1}.mol{sup -1}. The chirality of the hydroxyl products of the reactions has also been investigated. The results showed that the stereoselectivity of the hydroxyl products formed can be controlled by the selection of the solvent and enzyme used in these reactions. The thermochemical results for these reactions are compared with the results for reactions that have analogous structural features as well as with the results of quantum chemical calculations.

  3. Electrophoretic deposition of ZnO nanostructures: Au nanoclusters on Si substrates induce self-assembled nanowire growth

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval, Claudia [Laboratorio de Nanomateriales y Propiedades Dieléctricas, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán, San Miguel de Tucumán (Argentina); Marin, Oscar [CONICET – LAFISO, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán, San Miguel de Tucumán (Argentina); Real, Silvina [Laboratorio de Nanomateriales y Propiedades Dieléctricas, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán, San Miguel de Tucumán (Argentina); Comedi, David [CONICET – LAFISO, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán, San Miguel de Tucumán (Argentina); Tirado, Mónica, E-mail: mtirado@herrera.unt.edu.ar [Laboratorio de Nanomateriales y Propiedades Dieléctricas, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán, San Miguel de Tucumán (Argentina)

    2014-09-15

    Highlights: • ZnO nanowires were grown on silicon substrate by electrophoretic deposition technique without use a porous template. • The growth was induced by Au nanoclusters and was performed at room temperature. • The photoluminescence spectrum for the nanowires obtained shows a broad UV-blue excitonic emission peak and a low emission in the green region. - Abstract: The present work reports the self-assembled growth of ZnO nanowires on silicon substrate with nanometer sized Au clusters using electrophoretic deposition technique at room temperature without a sacrificial template. A colloidal suspension of ≈5 nm sized ZnO nanoparticles dispersed in 2-propanol was used (nanoparticle bandgap of 3.47 eV as determined from absorbance measurements). The results show that the Au nanoclusters on the silicon substrate induce the self-assembly of the ZnO nanoparticles into vertically aligned ZnO nanowires. This effect is tentatively explained as being due to increased electric field intensities near the Au nanoclusters during the electrophoretic deposition. Photoluminescence measurements reveal the presence of quantum confined excitons and a relatively low concentration of deep defects in the nanowires. The electric field guided growth of semiconductor nanostructures at room temperature has great industrial potential as it minimizes production costs and enables the use of substrate materials not withstanding high temperatures.

  4. Keynote address: cellular reduction of nitroimidazole drugs: potential for selective chemotherapy and diagnosis of hypoxic cells

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, J.D.; Lee, J.; Meeker, B.E.

    1989-04-01

    Nitroimidazole drugs were initially developed as selective radiosensitizers of hypoxic cells and, consequently, as adjuvants to improve the local control probabilities of current radiotherapies. Misonidazole (MISO), the prototype radiosensitizing drug, was found in Phase I clinical studies to cause dose-limiting neurotoxicities (mainly peripheral neuropathies). MISO was also found to be cytotoxic in the absence of radiation and to covalently bind to cellular molecules, both processes demonstrating rates much higher in hypoxic compared with oxygenated cells. It is likely that neurotoxicity, cellular cytotoxicity and adduct formation results from reactions between reduction intermediates of MISO and cellular target molecules. Spin-offs from radiosensitizer research include the synthesis and characterization of more potent hypoxic cytotoxins and the exploitation of sensitizer-adducts as probes for measuring cellular and tissue oxygen levels. Current developments in hypoxic cell cytotoxin and hypoxic cell marker research are reviewed with specific examples from studies which characterize the cellular reduction of TF-MISO, (1-(2-nitro-1-imidazolyl)-3(2,2,2-trifluoroethoxy)-2-propanol). 45 references.

  5. Fibrous scaffolds made by co-electrospinning soluble eggshell membrane protein with biodegradable synthetic polymers.

    Science.gov (United States)

    Xiong, Xi; Li, Qiang; Lu, Jian-Wei; Guo, Zhao-Xia; Sun, Zhao-Hui; Yu, Jian

    2012-01-01

    Soluble eggshell membrane protein (SEP), isolated from natural eggshell membrane, was co-electrospun with biodegradable synthetic polymers poly(propylene carbonate) (PPC) and poly(lactic acid) (PLA) in various proportions from 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) solutions in order to prepare fibrous scaffolds having simultaneously good mechanical properties and biocompatibility. The fiber morphology was observed by field emission scanning electron microscopy, showing uniform fibers with diameter of 1.2-1.0 and 1.3-0.7 um for PPC/SEP and PLA/SEP blend fibers, respectively. Transmission electron microscopy observation shows that the blend fibers have domain-matrix phase morphology with fiber-like SEP domains in the PPC or PLA matrix, indicating the occurrence of phase separation, although interaction exists between PPC (or PLA) and SEP, as revealed by attenuated total reflectance Fourier transform infrared spectroscopy. The mechanical properties were evaluated by uniaxial tensile tests and showed that both the tensile strength and elongation at break increase with increasing incorporation of PPC (or PLA). The surface composition was investigated by X-ray photoelectron spectroscopy and SEP was found on the fiber surfaces, and as a result the surfaces of the fibrous scaffolds are superhydrophilic. NIH3T3 cell culture tests demonstrate that the PPC/SEP and PLA/SEP blend fibrous scaffolds have a much improved biocompatibility compared to pure PPC or PLA fibrous scaffolds.

  6. Biodegradable drug-eluting nanofiber-enveloped implants for sustained release of high bactericidal concentrations of vancomycin and ceftazidime: in vitro and in vivo studies.

    Science.gov (United States)

    Hsu, Yung-Heng; Chen, Dave Wei-Chih; Tai, Chun-Der; Chou, Ying-Chao; Liu, Shih-Jung; Ueng, Steve Wen-Neng; Chan, Err-Cheng

    2014-01-01

    We developed biodegradable drug-eluting nanofiber-enveloped implants that provided sustained release of vancomycin and ceftazidime. To prepare the biodegradable nanofibrous membranes, poly(D,L)-lactide-co-glycolide and the antibiotics were first dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol. They were electrospun into biodegradable drug-eluting membranes, which were then enveloped on the surface of stainless plates. An elution method and a high-performance liquid chromatography assay were employed to characterize the in vivo and in vitro release rates of the antibiotics from the nanofiber-enveloped plates. The results showed that the biodegradable nanofiber-enveloped plates released high concentrations of vancomycin and ceftazidime (well above the minimum inhibitory concentration) for more than 3 and 8 weeks in vitro and in vivo, respectively. A bacterial inhibition test was carried out to determine the relative activity of the released antibiotics. The bioactivity ranged from 25% to 100%. In addition, the serum creatinine level remained within the normal range, suggesting that the high vancomycin concentration did not affect renal function. By adopting the electrospinning technique, we will be able to manufacture biodegradable drug-eluting implants for the long-term drug delivery of different antibiotics.

  7. Structural, optical and morphological analyses of pristine titanium di-oxide nanoparticles--synthesized via sol-gel route.

    Science.gov (United States)

    Praveen, P; Viruthagiri, G; Mugundan, S; Shanmugam, N

    2014-01-03

    Pure titanium di-oxide nanoparticles (TiO2) were synthesized by sol-gel technique at room temperature with appropriate reactants. The synthesis of anatase phase TiO2 nanoparticles was achieved by tetraisopropyl orthotitanate and 2-propanol as common starting materials and the product was annealed at 450 °C for 4 h. The synthesized product was characterized by X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), UV-VIS-Diffuse reflectance spectroscopy (DRS), Photoluminescence (PL) spectroscopy and Scanning electron microscopy (SEM) with Energy dispersive X-ray (EDX) analysis. XRD pattern confirmed the crystalline nature and tetragonal structure of synthesized composition. Average grain size was determined from X-ray line broadening, using the Debye-Scherrer relation. The functional groups present in the sample were identified by FTIR spectroscopy. Diffuse reflectance measurement indicated an absorption band edge on UV-region. The allowed direct and indirect band gap energies, as well as the crystallite size of pure TiO2 nanoparticles are calculated from DRS analysis. The microstructure and elemental identification were done by SEM with EDX analysis.

  8. Arsenic(III) and iron(II) co-oxidation by oxygen and hydrogen peroxide: divergent reactions in the presence of organic ligands.

    Science.gov (United States)

    Wang, Zhaohui; Bush, Richard T; Liu, Jianshe

    2013-11-01

    Iron-catalyzed oxidation of As(III) to As(V) can be highly effective for toxic arsenic removal via Fenton reaction and Fe(II) oxygenation. However, the contribution of ubiquitous organic ligands is poorly understood, despite its significant role in redox chemistry of arsenic in natural and engineered systems. In this work, selected naturally occurring organic ligands and synthetic ligands in co-oxidation of Fe(II) and As(III) were examined as a function of pH, Fe(II), H2O2, and radical scavengers (methanol and 2-propanol) concentration. As(III) was not measurably oxidised in the presence of excess ethylenediaminetetraacetic acid (EDTA) (i.e. Fe(II):EDTAorganic ligands did not necessarily result in the coupled As(III) oxidation. Organic ligands act as both iron speciation regulators and radicals scavengers. Further quenching experiments suggested both hydroxyl radicals and high-valent Fe species contributed to As(III) oxidation. The present findings are significant for the better understanding of aquatic redox chemistry of iron and arsenic in the environment and for optimization of iron-catalyzed arsenic remediation technology.

  9. Synthesis and Crystal Structure of an Incomplete Cubane-type Mo3S4 Cluster with the N-N-O Type Tridentate Ligand:{Mo3S4[NH2CH2CH(O)CH2NH2]3}(DTP)·(H2O)2·(DMF)

    Institute of Scientific and Technical Information of China (English)

    HU Rui-Feng; QIN Ye-Yan; KANG Yao; ZHANG Jian; WEN Yi-Hang; LI Zhao-Ji; CHEN Jiu-Tong; YAO Yuan-Gen

    2005-01-01

    A new cluster {Mo3S4[NH2CH2CH(O)CH2NH2]3}(DTP)·(H2O)2·(DMF) (DTP = diethyldithiophosphate) has been synthesized via ligand substitution reaction of Mo3S4(DTP)4(H2O) with an alkaline ligand 1,3-diamino-2-propanol(DAPROH) in a mixed organic solvent, and its crys- tal structure was determined with the following data: Mo3S6PC16H48O8N7, Mr = 977.76, triclinic, space group P, Z = 2, a = 10.319(2), b = 12.843(3), c = 15.335(3)(A), α = 65.26(3), β = 82.18(3), γ = 70.67(3)o, V = 1741.7(6) (A)3, Dc = 1.864 g/cm3, μ = 1.517 mm-1, F(000) = 988, the final R = 0.0794 and wR = 0.2111 for 6318 observed reflections (I>2σ(I)). The structure analysis indicates that all DTP ligands of Mo3S4(DTP)4(H2O) are replaced and each DAPRO molecule acts as a tri- dentate ligand chelating to each Mo atom of the Mo3S4 core. Different from the precursor, the clus- ter symmetry is elevated to C3. In addition, the UV-spectrum of the title compound was measured.

  10. Size-selective recognition of catecholamines by molecular imprinting on silica-alumina gel.

    Science.gov (United States)

    Ling, Tzong-Rong; Syu, Yau Zen; Tasi, Yau-Ching; Chou, Tse-Chuan; Liu, Chung-Chiun

    2005-12-15

    The preparation of a catecholamine receptor was carried out using a molecular imprinting method with silica-alumina gel to form complementary structures for template recognition. The molecularly imprinted polymer (MIP) was synthesized by the condensation of silicate from tetraethyl orthosilictate (TEOS) under hydrothermal conditions at 60 degrees C. Aluminum chloride was added as a functional monomer to increase the material's rebinding ability. The selectivity of the MIP receptor prepared with different ratios of template to Si and Al, was examined with seven analytes including: dopamine, epinephrine, norepinephrine, ascorbic acid, homovanillic acid, uric acid, and l-tyrosine. The results showed a size selective effect for the receptors with respect to the recognition of the catecholamines. Some factors affecting the recognition ability were investigated including: the solution pH of analytes, surface capping on the MIP, and the imprinting pH of the silica-alumina solution. Also, the catecholamine MIP films on quartz crystal microbalance (QCM) electrodes were fabricated as sensors for in situ monitoring of the analytes in a 2-propanol solution.

  11. Understanding the gas sensing properties of polypyrrole coated tin oxide nanofiber mats

    Science.gov (United States)

    Bagchi, Sudeshna; Ghanshyam, C.

    2017-03-01

    Tin oxide-polypyrrole composites have been widely studied for their enhanced sensing performance towards ammonia vapours, but further investigations are required for an understanding of the interaction mechanisms with different target analytes. In this work, polypyrrole coated tin oxide fibers have been synthesized using a two-step approach of electrospinning and vapour phase polymerization for the sensing of ammonia, ethanol, methanol, 2-propanol and acetone vapours. The resistance variation in the presence of these vapours of different nature and concentration is investigated for the determination of sensor response. A decrease in resistance occurred on interaction of tin oxide-polypyrrole with ammonia, as opposed to previous reported works. Partial reduction of polypyrrole due to interfacial interaction with tin oxide has been proposed to explain this behavior. High sensitivity of 7.45 is achieved for 1 ppm ammonia concentration. Furthermore, the sensor exhibited high sensitivity and a faster response towards ethanol vapours although methanol has the highest electron donating capability. The catalytic mechanism has been discussed to explain this interesting behavior. The results reveal that interaction between tin oxide and polypyrrole is crucial to control the predominant sensing mechanism.

  12. Fiber content of diet affects exhaled breath volatiles in fasting and postprandial state in a pilot crossover study.

    Science.gov (United States)

    Raninen, Kaisa J; Lappi, Jenni E; Mukkala, Maria L; Tuomainen, Tomi-Pekka; Mykkänen, Hannu M; Poutanen, Kaisa S; Raatikainen, Olavi J

    2016-06-01

    Our pilot study examined the potential of exhaled breath analysis in studying the metabolic effects of dietary fiber (DF). We hypothesized that a high-fiber diet (HFD) containing whole grain rye changes volatile organic compound (VOC) levels in exhaled breath and that consuming a single meal affects these levels. Seven healthy men followed a week-long low-fiber diet (17 g/d) and HFD (44 g/d) in a randomized crossover design. A test meal containing 50 g of the available carbohydrates from wheat bread was served as breakfast after each week. Alveolar exhaled breath samples were analyzed at fasting state and 30, 60, and 120 minutes after this meal parallel to plasma glucose, insulin, and serum lipids. We used solid-phase microextraction and gas chromatography-mass spectrometry for detecting changes in 15 VOCs. These VOCs were acetone, ethanol, 1-propanol, 2-propanol, 1-butanol, acetic acid, propionic acid, butyric acid, valeric acid, isovaleric acid, 2-methylbutyric acid, hexanoic acid, acetoin, diacetyl, and phenol. Exhaled breath 2-methylbutyric acid in the fasting state and 1-propanol at 120 minutes decreased (P = .091 for both) after an HFD. Ingestion of the test meal increased ethanol, 1-propanol, acetoin, propionic acid, and butyric acid levels while reducing acetone, 1-butanol, diacetyl, and phenol levels. Both DF diet content and having a single meal affected breathVOCs. Exploring exhaled breath further could help to develop tools for monitoring the metabolic effects of DF.

  13. Catalyst-Free Synthesis of ZnO Nanowires on Oxidized Silicon Substrate for Gas Sensing Applications.

    Science.gov (United States)

    Behera, B; Chandra, S

    2015-06-01

    In the present work, we report the synthesis of nanostructured ZnO by oxidation of zinc film without using a seed or catalyst layer. The zinc films were deposited on oxidized Si substrates by RF magnetron sputtering process. These were oxidized in dry and wet air/oxygen ambient. The optimized process yielded long nanowires of ZnO having diameter of around 60-70 nm and spread uniformly over the surface. The effect of oxidation temperature, time, Zn film thickness and the ambient has strong influence on the morphology of resulting nanostruxctured ZnO film. The films were characterized by scanning electron microscopy for morphological studies and X-ray diffraction (XRD) analysis to study the phase of the nanostructured ZnO. Room temperature photoluminescence (PL) measurements of the nanowires show UV and green emission. A sensor was designed and fabricated using nanostructured ZnO film, incorporating inter-digital-electrode (IDE) for the measurement of resistance of the sensing layer. The gas sensing properties were investigated from the measurement of change in resistance when exposed to vapours of different volatile organic compound (VOC) such as acetone, ethanol, methanol and 2-propanol. The results suggest that ZnO nanowires fabricated by this method have potential application in gas sensors.

  14. A novel aqueous two phase system composed of a thermo-separating polymer and an organic solvent for purification of thermo-acidic amylase enzyme from red pitaya (Hylocereus polyrhizus) peel.

    Science.gov (United States)

    Amid, Mehrnoush; Manap, Yazid; Zohdi, Nor Khanani

    2014-05-22

    The purification of thermo-acidic amylase enzyme from red pitaya (Hylocereus polyrhizus) peel for the first time was investigated using a novel aqueous two-phase system (ATPS) consisting of a thermo-separating copolymer and an organic solvent. The effectiveness of different parameters such as molecular weight of the thermo-separating ethylene oxide-propylene oxide (EOPO) copolymer and type and concentration of organic solvent on the partitioning behavior of amylase was investigated. In addition, the effects of phase components, volume ratio (VR), pH and crude load of purification factor and yield of amylase were evaluated to achieve the optimum partition conditions of the enzyme. In the novel ATPS method, the enzyme was satisfactorily partitioned into the polymer-rich top phase in the system composed of 30% (w/w) EOPO 2500 and 15% (w/w) 2-propanol, at a volume ratio of 1.94 and with a crude load scale of 25% (w/w) at pH 5.0. Recovery and recycling of components was also measured in each successive step of the ATPS process. The enzyme was successfully recovered by the method with a high purification factor of 14.3 and yield of 96.6% and copolymer was also recovered and recycled at a rate above 97%, making the method was more economical than the traditional ATPS method.

  15. A Novel Aqueous Two Phase System Composed of a Thermo-Separating Polymer and an Organic Solvent for Purification of Thermo-Acidic Amylase Enzyme from Red Pitaya (Hylocereus polyrhizus Peel

    Directory of Open Access Journals (Sweden)

    Mehrnoush Amid

    2014-05-01

    Full Text Available The purification of thermo-acidic amylase enzyme from red pitaya (Hylocereus polyrhizus peel for the first time was investigated using a novel aqueous two-phase system (ATPS consisting of a thermo-separating copolymer and an organic solvent. The effectiveness of different parameters such as molecular weight of the thermo-separating ethylene oxide-propylene oxide (EOPO copolymer and type and concentration of organic solvent on the partitioning behavior of amylase was investigated. In addition, the effects of phase components, volume ratio (VR, pH and crude load of purification factor and yield of amylase were evaluated to achieve the optimum partition conditions of the enzyme. In the novel ATPS method, the enzyme was satisfactorily partitioned into the polymer-rich top phase in the system composed of 30% (w/w EOPO 2500 and 15% (w/w 2-propanol, at a volume ratio of 1.94 and with a crude load scale of 25% (w/w at pH 5.0. Recovery and recycling of components was also measured in each successive step of the ATPS process. The enzyme was successfully recovered by the method with a high purification factor of 14.3 and yield of 96.6% and copolymer was also recovered and recycled at a rate above 97%, making the method was more economical than the traditional ATPS method.

  16. Figures of merit in the quantification of ibuprofen enantiomers by chiral HPLC.

    Science.gov (United States)

    Valderrama, Patrícia; Romero, Adriano Lopes; Imamura, Paulo Mitsuo; Poppi, Ronei Jesus

    2009-10-01

    The determination of ibuprofen (IBU) enantiomers by chiral high-performance liquid chromatographic is described. The methodology is based on chiral recognition of ibuprofen by a chiral column based on cellulose tris(4-methylbenzoate) coated on silica gel (Chiralcel OJ-H). The mobile phase is n-hexane-2-propanol-trifluoroacetic acid (98:2:0.1, v/v/v). The flow rate was 1.0 mL/min, and UV detection was 254 nm. The samples of ibuprofen were prepared in n-hexane in the concentration range 50-100% of (S)-IBU 1 x 10(-3) mol/L. Calibration and validation method were performed with six and nine samples, respectively. Goodness-of-fit measures represented by correlation coefficient, y-intercept, and slope of the regression line were 0.9836, 21373, 2162, respectively. Average of the relative error of the proposed method was 3.0%, 0.9% (S)-IBU selectivity, and 2162% (S)-IBU-1 sensitivity. The minimum concentration difference between two samples that could be determined in the linear dynamic range was 0.4% (S)-IBU. Limits of detection and quantification were 8.1 and 27.0% (S)-IBU, respectively. These results indicate that the proposed method can be employed for determination of the enantiomeric composition of IBU.

  17. Effects of crystallization in the presence of the diastereomer on the crystal properties of (SS)-(+)-pseudoephedrine hydrochloride.

    Science.gov (United States)

    Gu, C H; Grant, D J

    2000-01-01

    The formation and separation of diastereomers is widely used to resolve enantiomers. However, during crystallization of a chiral compound from a solution containing its diastereomer, the diastereomer may be incorporated as an impurity into the host crystal lattice, leading to changes in the thermodynamic properties and intrinsic dissolution rate of the host crystals. This hypothesis was tested by growing crystals of (SS)-(+)-pseudoephedrine hydrochloride (+PC) from aqueous solution containing various amounts of (RS)-(-)-ephedrine hydrochloride (-EC). Although the melting phase diagram of these two solid compounds, determined by differential scanning calorimetry (DSC), shows eutectic behavior, 0.034-2.4 mol% of -EC was incorporated into the crystal lattice of +PC during crystallization to form terminal solid solutions with a segregation coefficient of 0.31. In a single batch, the larger crystals contain more incorporated impurities than smaller crystals. The enthalpy and entropy of fusion measured by DSC decrease with increasing incorporation of the guest molecules into the host, indicating increases in the enthalpy and entropy of the solid. The disruption index, which indicates the disruptive effect of guest molecules in the host crystal lattice, is 60 at lattice. The average intrinsic dissolution rate of impure crystals in 2-propanol is 15.8% lower than that of pure host crystals, suggesting the formation of stable solid solutions.

  18. Improved Polymerase Chain Reaction-restriction Fragment Length Polymorphism Genotyping of Toxic Pufferfish by Liquid Chromatography/Mass Spectrometry.

    Science.gov (United States)

    Miyaguchi, Hajime

    2016-09-20

    An improved version of a polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method for genotyping toxic pufferfish species by liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS) is described. DNA extraction is carried out using a silica membrane-based DNA extraction kit. After the PCR amplification using a detergent-free PCR buffer, restriction enzymes are added to the solution without purifying the reaction solution. A reverse-phase silica monolith column and a Fourier transform high resolution mass spectrometer having a modified Kingdon trap analyzer are employed for separation and detection, respectively. The mobile phase, consisting of 400 mM 1,1,1,3,3,3-hexafluoro-2-propanol, 15 mM triethylamine (pH 7.9) and methanol, is delivered at a flow rate of 0.4 ml/min. The cycle time for LC/ESI-MS analysis is 8 min including equilibration of the column. Deconvolution software having an isotope distribution model of the oligonucleotide is used to calculate the corresponding monoisotopic mass from the mass spectrum. For analysis of oligonucleotides (range 26-79 nucleotides), mass accuracy was 0.62 ± 0.74 ppm (n = 280) and excellent accuracy and precision were sustained for 180 hr without use of a lock mass standard.

  19. High performance liquid chromatographic analysis of the pharmacologically active quinones and related compounds in the oil of the black seed (Nigella sativa L.).

    Science.gov (United States)

    Ghosheh, O A; Houdi, A A; Crooks, P A

    1999-04-01

    An HPLC method for quantifying the putative pharmacologically active constituents: thymoquinone (TQ), dithymoquinone (DTQ), thymohydroquinone (THQ), and thymol (THY), in the oil of Nigella sativa seed is described. Extraction of the constituents from the oil was carried out using C18 PrepSep mini columns followed by quantification of the recovered constituents by HPLC on a reversed-phase muBondapak C18 analytical column, using an isocratic mobile phase of water:methanol:2-propanol (50:45:5% v/v) at a flow rate of 2 ml min(-1). UV detection was at 254 nm for TQ, DTQ, and THY, and at 294 nm for THQ. The above four compounds were separated with good resolution, reproducibility, and sensitivity under these conditions. This analytical method was used to quantify the above four constituents in a commercial sample of N. sativa seed oil, and provides a good quality control methodology for the pharmacologically active components in this widely used natural remedy.

  20. Separación de las clases de lípidos neutros de polen apícola mediante cromatografía líquida de alta resolución (HPLC

    Directory of Open Access Journals (Sweden)

    Muniategui, S.

    1991-08-01

    Full Text Available A fast method for the separation of neutral lipid classes of bee-collected pollen by isocratic HPLC is described using ultraviolet detection at 206 nm and direct injection of the sample into a silica column. The mobile phase was n-hexane-2-propanolacetic acid (100:0.5:0.1. Three fractions of neutral lipids were isolated from 35 samples: Sterol esters and other nonpolar compounds such as carotenoids and waxes; triglycerides; and fatty acids.

    Se describe un método rápido mediante HPLC para la separación de las diferentes clases de lípidos neutros del polen apícola en condiciones isocráticas, con detección UV a 206 nm e inyección directa de la muestra en columna de sílica. Como fase móvil se usa n-hexano-2-propanol-ácido acético (100:0,5:0,1. Se aislaron 3 fracciones de lípidos neutros en las 35 muestras analizadas: Esteres de esteroles y otros componentes no polares tales como carotenoides y ceras; triglicéridos y ácidos grasos.

  1. High-field ELDOR-detected NMR study of a nitroxide radical in disordered solids: Towards characterization of heterogeneity of microenvironments in spin-labeled systems

    Science.gov (United States)

    Nalepa, Anna; Möbius, Klaus; Lubitz, Wolfgang; Savitsky, Anton

    2014-05-01

    The combination of high-field EPR with site-directed spin-labeling (SDSL) techniques employing nitroxide radicals has turned out to be particularly powerful in probing the polarity and proticity characteristics of protein/matrix systems. This information is concluded from the principal components of the nitroxide Zeeman (g), nitrogen hyperfine (A) and quadrupole (P) tensors of the spin labels attached to specific sites. Recent multi-frequency high-field EPR studies underlined the complexity of the problem to treat the nitroxide microenvironment in proteins adequately due to inherent heterogeneities which result in several principal x-components of the nitroxide g-tensor. Concomitant, but distinctly different nitrogen hyperfine components could, however, not be determined from high-field cw EPR experiments owing to the large intrinsic EPR linewidth in fully protonated guest/host systems. It is shown in this work that, using the W-band (95 GHz) ELDOR- (electron-electron double resonance) detected NMR (EDNMR) method, different principal nitrogen hyperfine, Azz, and quadrupole, Pzz, tensor values of a nitroxide radical in glassy 2-propanol matrix can be measured with high accuracy. They belong to nitroxides with different hydrogen-bond situations. The satisfactory resolution and superior sensitivity of EDNMR as compared to the standard ENDOR (electron-nuclear double resonance) method are demonstrated.

  2. Room temperature alcohol sensing by oxygen vacancy controlled TiO{sub 2} nanotube array

    Energy Technology Data Exchange (ETDEWEB)

    Hazra, A.; Dutta, K.; Bhowmik, B.; Bhattacharyya, P., E-mail: pb-etc-besu@yahoo.com [Nano-Thin Films and Solid State Gas Sensor Devices Laboratory, Department of Electronics and Telecommunication Engineering, Indian Institute of Engineering Science and Technology (IIEST), Shibpur, Howrah (India); Chattopadhyay, P. P. [Department of Metallurgy and Materials Engineering, Indian Institute of Engineering Science and Technology (IIEST), Shibpur, Howrah (India)

    2014-08-25

    Oxygen vacancy (OV) controlled TiO{sub 2} nanotubes, having diameters of 50–70 nm and lengths of 200–250 nm, were synthesized by electrochemical anodization in the mixed electrolyte comprising NH{sub 4}F and ethylene glycol with selective H{sub 2}O content. The structural evolution of TiO{sub 2} nanoforms has been studied by field emission scanning electron microscopy. Variation in the formation of OVs with the variation of the structure of TiO{sub 2} nanoforms has been evaluated by photoluminescence and X-ray photoelectron spectroscopy. The sensor characteristics were correlated to the variation of the amount of induced OVs in the nanotubes. The efficient room temperature sensing achieved by the control of OVs of TiO{sub 2} nanotube array has paved the way for developing fast responding alcohol sensor with corresponding response magnitude of 60.2%, 45.3%, and 36.5% towards methanol, ethanol, and 2-propanol, respectively.

  3. A rapid and sensitive technique for assessing exposure to VX via GC-MS-MS analysis.

    Science.gov (United States)

    McGuire, Jeffrey M; Byers, Christopher E; Hulet, Stanley W; Jakubowski, Edward M; Thomson, Sandra A

    2008-01-01

    A rapid and sensitive method for the determination of the chemical warfare agent VX in plasma taken from Göttingen minipigs has been developed using isotope-dilution gas chromatography-tandem mass spectrometry (GC-MS-MS). Chromatographic separation was achieved on a 5% diphenyl/95% dimethyl polysiloxane capillary column with a total run time of about 11 min. The analyte was detected using ammonia chemical ionization in the multiple reaction monitoring mode, following a simple extraction with 10% 2-propanol in hexane. A good linear relationship was obtained in the quantitative concentration range of 10 ng/mL to 1000 ng/mL (r(2) = 0.9998) with an average slope of 1.275 +/- 0.037 (n = 7), and an absolute detection limit of 0.4 pg on column. The average recovery for VX was 95% in saline in the concentration range of 50-100 ng/mL. The method was successfully applied to the analysis of VX in minipig plasma in a preliminary toxicokinetic study.

  4. Solid-base loaded WO{sub 3} photocatalyst for decomposition of harmful organics under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kako, Tetsuya, E-mail: kako.tetsuya@nims.go.jp [Environmental Remediation Materials Unit, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Meng, Xianguang; Ye, Jinhua [Environmental Remediation Materials Unit, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Graduate School of Chemical Science and Engineering, Hokkaido University, Sapporo 060-0814 (Japan)

    2015-10-01

    Composite of NaBiO{sub 3}-loaded WO{sub 3} with a mixing ratio of 10:100 was prepared for photocatalytic harmful-organic-contaminant decomposition. The composite properties were measured using X-ray diffraction, ultraviolet-visible spectrophotometer (UV-Vis), and valence band-X-ray photoelectron spectroscope (VB-XPS). The results exhibited that the potentials for top of the valence band and bottom of conduction band for NaBiO{sub 3} can be estimated, respectively, as +2.5 V and -0.1 to 0 V. Furthermore, WO{sub 3}, NaBiO{sub 3}, and the composite showed IPA oxidation properties under visible-light irradiation. Results show that the composite exhibited much higher photocatalytic activity about 2-propanol (IPA) decomposition into CO{sub 2} than individual WO{sub 3} or NaBiO{sub 3} because of charge separation promotion and the base effect of NaBiO{sub 3}.

  5. Preparation and characterization of chitin beads as a wound dressing precursor.

    Science.gov (United States)

    Yusof, N L; Lim, L Y; Khor, E

    2001-01-01

    Chitin was dissolved in N, N-dimethylacetamide/5% lithium chloride (DMAc/5%LiCl) to form a 0.5% chitin solution. Chitin beads were formed by dropping the 0.5% chitin solution into a nonsolvent coagulant, ethanol. The beads were left in ethanol for 24 h to permit hardening, consolidation, and removal of residual DMAc/5%LiCl solvent in order to give spherical chitin beads uniform size distribution. The ethanol-gelled chitin beads had an average diameter of 535 microm. The chitin beads were subsequently activated in 50% (w/v) NaOH solution and reacted with 1.9 M monochloroacetic acid/2-propanol solution to introduce a carboxymethylated surface layer to the chitin beads. The bilayer character of the surface-carboxymethylated chitin (SCM-chitin) beads was verified by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and confocal microscopy. The bilayered SCM-chitin beads were found to absorb up to 95 times their dry weight of water. These SCM-chitin beads have potential as a component of wound dressings.

  6. Efficient separation of tanshinones by polyvinylpyrrolidone-stabilized graphene-modified micellar electrokinetic chromatography.

    Science.gov (United States)

    Yang, Hua; Ding, Yao; Gao, Wen; Qi, Lian-Wen; Cao, Jun; Li, Ping

    2015-12-01

    In this work, a PVP-stabilized graphene was used in MEKC for the separation of tanshinones. Seven structurally similar tanshinones were studied, that is, tanshinone IIB, dihydrotanshinone I, tanshinone I, cryptotanshinone, 1,2-dihydrotanshinone I, miltirone, and tanshinone IIA. To achieve optimal conditions, graphene concentration, sample solvent composition, SDS concentration, 2-propanolconcentration, and buffer pH were investigated. At a separation voltage of 30 kV and a 41.5 cm effective length fused-silica capillary, good resolution within 12 min was performed using 10 mM borate buffer (pH 9.3) containing 30 mM SDS, 10% v/v 2-propanol and 6 μg/mL graphene. The method was validated in terms of linearity (r(2) > 0.9970), intra- and inter-day precision were less than 3.56 and 4.83%, respectively. The proposed method was then successfully applied to Danshentong capsule, an herbal preparation from Salvia miltiorrhiza. Our results indicated the high separation efficiency of PVP-stabilized graphene provided new opportunities for the analysis of complex samples.

  7. Micellar Electrokinetic Chromatographic Study of the Separation of an Aromatase Inhibitor and a Tryciclic Antidepressant in the Breast Cancer Treatment

    Directory of Open Access Journals (Sweden)

    J. Rodríguez Flores

    2008-01-01

    Full Text Available Micellar electrokinetic chromatography (MEKC was investigated for the simultaneous determination of letrozole, imipramine and their metabolites in human urine samples over a concentration range of therapeutic interest. Experimental parameters such as pH of the running electrolyte, sodium dodecylsulphate (SDS concentration, borate concentration, voltage, etc were investigated. Under optimal conditions of 25 mM SDS, 15 mM borate buffer (pH 9.2, 15% 2-propanol, as back- ground electrolyte; 28 kV and 40 ºC, as voltage and cartridge temperature, respectively; resolution between the peaks was greater than 1.7. Before the determination, a solid phase extraction (SPE procedure with a C18 cartridge was optimized. Good linearity, accuracy, precision, robustness and ruggedness were achieved and detection limits of 12.5 ng/mL for letrozole and its metabolite and 37.5 ng/mL, were obtained for imipramine and their metabolites. Real determinations of these analytes in two patient urines were carried out. Sensitivity achieved in this method is sufficient to perform kinetic studies in humans.

  8. Single Pulse Remote Raman Detection of Minerals and Organics Under Illuminated Condition from 10 Meters Distance

    Science.gov (United States)

    Misra, A. K.; Sharma, S. K.; Lucey, P. G.

    2005-01-01

    A directly coupled portable remote Raman instrument developed by the University of Hawaii has been shown here to identify several minerals, chemicals and organics from a distance of 10 m using a single laser pulse in a well illuminated background. Raman spectra, obtained during a very short period of time, of common minerals e.g., dolomite, calcite, marble, barite, gypsum, quarts, rutile, fluorapatite etc. clearly show Raman features which could be used as fingerprints for mineral identification. Raman features of organics such as benzene, cyclohexane, 2-propanol, naphthalene, etc. and other chemicals containing various functional groups like oxides, silicates, sulphates, nitrates, phosphates and carbonates were also easily detected. Ability to measure Raman spectra with a single laser pulse would be promising for future space missions where power consumption is critical and a rapid survey of the minerals with moderate to high Raman cross section might be desirable for selecting rocks that would provide high scientific return or for acquiring rocks for sample return to the Earth.

  9. Efficacy of alcohol-based gels compared with simple hand wash and hygienic hand disinfection.

    Science.gov (United States)

    Kampf, G; Ostermeyer, C

    2004-04-01

    A recent research letter on the limited efficacy of alcohol-based hand gels has alerted the global infection control community and raised the question of the true significance of data obtained according to EN 1500. It has been described that a 1 min simple hand wash reduces artificial contamination of hands by a log(10) reduction factor of 2.8 and a 1 min reference hand disinfection with 2-propanol (60%, v/v) by a factor of 4.6 steps. The EN 1500 gel data show that the 30 s efficacy of most gels is closer to a simple hand wash than to the reference hand disinfection. The 30 s efficacy of most alcohol-based liquid products and one gel, however, is almost identical to the reference hand disinfection. In many European countries alcohol-based liquid products have been established as a standard practice in hygienic hand disinfection for decades. Replacement of these products with most available gels would be a step backward in terms of efficacy and has still to be seen critically from the efficacy point of view.

  10. Decay kinetics of benzophenone triplets and corresponding free radicals in soft and rigid polymers studied by laser flash photolysis.

    Science.gov (United States)

    Levin, Peter P; Efremkin, Alexei F; Sultimova, Natalie B; Kasparov, Valery V; Khudyakov, Igor V

    2014-01-01

    The kinetics of transients formed under photoexcitation of benzophenone (B) dissolved in three different polymers was studied by ns laser flash photolysis. These polymers were the soft rubbers poly (ethylene-co-butylene) (EB), polystyrene block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) and hard polystyrene (PS). We monitored the decay kinetics of triplet state (3)B(*) and of ketyl radicals BH(●). We observed exponential decay of (3)B(*) and two-stage decay kinetics of BH(●) in EB. The first stage is a fast cage recombination of a radical pair (BH(●), radical of polymer R(●)). The second slow stage of BH(●) decay follows the second-order law with a relatively high rate constant, which corresponds to recombination of BH(●) in a homogeneous liquid with a viscosity of only ~0.1 P (about five times of 2-propanol viscosity). Application of a magnetic field (MF) of 0.2 T leads to deceleration of both stages of BH(●) decay in EB by approximately 20%. Decay kinetics of both transients were observed in SEBS. There was no MF effect on BH(●) decay in SEBS. We only observed (3)B(*) in PS. Decay kinetics of (3)B(*) in this case were described as polychromatic dispersive first-order kinetics. We discuss the effects of polymer structure on transient kinetics and the MF effect.

  11. Size-exclusion chromatography of poly(ethylene 2,6-naphthalate).

    Science.gov (United States)

    Mourey, T H; Slater, L A; Galipo, R C; Janes, D L; Moody, R E

    2012-09-21

    A solvent mixture of 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) and dichloroacetic acid (DCAA) is used to dissolve difficultly soluble poly(ethylene 2,6-naphthalate) (PEN). Solutions can be diluted and analyzed in a common size-exclusion chromatography (SEC) eluent, HFIP. The HFIP/DCAA mixture is better at dissolving PEN than either solvent individually and it is easier and safer to work with than phenolic and strongly acidic eluents. Dissolution temperatures between 50 and 60 °C are sufficiently low to minimize hydrolytic degradation of the polyester. PEN does not dissolve in the solvent mixture if the water concentration is greater than 0.76 wt%, and preferably the water content should be less than 0.13 wt% to eliminate minor prepeak artifacts. The procedure is suitable for PEN that is less than 48% crystalline, including prepolymers, oriented films and some solid-state polymerized materials. Highly crystalline polymers can be melt-quenched into a more amorphous state to render them soluble. The dilute solution conformational properties of PEN are compared to PET in HFIP, and molar mass-intrinsic viscosity scaling constants and unperturbed dimensions are calculated from SEC data.

  12. Identification of Wet-Spinning and Post-Spin Stretching Methods Amenable to Recombinant Spider Aciniform Silk.

    Science.gov (United States)

    Weatherbee-Martin, Nathan; Xu, Lingling; Hupe, Andre; Kreplak, Laurent; Fudge, Douglas S; Liu, Xiang-Qin; Rainey, Jan K

    2016-08-01

    Spider silks are outstanding biomaterials with mechanical properties that outperform synthetic materials. Of the six fibrillar spider silks, aciniform (or wrapping) silk is the toughest through a unique combination of strength and extensibility. In this study, a wet-spinning method for recombinant Argiope trifasciata aciniform spidroin (AcSp1) is introduced. Recombinant AcSp1 comprising three 200 amino acid repeat units was solubilized in a 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)/water mixture, forming a viscous α-helix-enriched spinning dope, and wet-spun into an ethanol/water coagulation bath allowing continuous fiber production. Post-spin stretching of the resulting wet-spun fibers in water significantly improved fiber strength, enriched β-sheet conformation without complete α-helix depletion, and enhanced birefringence. These methods allow reproducible aciniform silk fiber formation, albeit with lower extensibility than native silk, requiring conditions and methods distinct from those previously reported for other silk proteins. This provides an essential starting point for tailoring wet-spinning of aciniform silk to achieve desired properties.

  13. Morphological Effect of CNT/TiO2 Nanocomposite Photoelectrodes Dye-Sensitized Solar Cell on Photovoltaic Performance with Various Annealing Temperatures

    Directory of Open Access Journals (Sweden)

    Mohd Zikri Razali

    2015-01-01

    Full Text Available This research focused on the fabrication of dye-sensitized solar cell based on a photoanode of carbon nanotube/titanium dioxide (CNT/TiO2 nanocomposite photoanode synthesized through acid-catalyzed sol-gel method. The results show the improvement of the chemical and electrical properties of the solar cells annealed at different temperatures. The CNT/TiO2 colloidal solution was synthesized using titanium tetraisopropoxide and CNT/2-propanol solution. The thin films were doctor-bladed on a fluorine tin oxide glass before being annealed at 550, 650, and 750°C. The field emission scanning electron microscopy morphological images show that the thin films were homogenously distributed and maintained their spherical structures. The X-ray diffraction patterns show that the films consisted of anatase and rutile phases with large crystallite sizes due to temperature increment. The atomic force microscopy analysis presents the thin film roughness in terms of root mean square roughness. The photovoltaic performance was analyzed using IV curve and electrochemical impedance spectroscopy (EIS. The thin films annealed at 750°C had the highest energy conversion efficiency at 5.23%. The EIS analysis estimated the values of the effective electron lifetime (τeff, effective electron diffusion coefficient, effective electron diffusion (Ln, and effective recombination rate constant (keff. A large τeff, small keff, and longer Ln can improve photovoltaic performance efficiency.

  14. Improvement of the Dimensional Stability of Powder Injection Molded Compacts by Adding Swelling Inhibitor into the Debinding Solvent

    Science.gov (United States)

    Fan, Yang-Liang; Hwang, Kuen-Shyang; Su, Shao-Chin

    2008-02-01

    Defects are frequently found in powder injection molded (PIM) compacts during solvent debinding due to the swelling of the binders. This problem can be alleviated by adjusting the composition of the debinding solvent. In this study, 10 vol pct swelling inhibitors were added into heptane, and the in-situ amounts of swelling and sagging of the specimen in the solvent were recorded using a noncontacting laser dilatometer. The results show that the addition of ethanol, 2-propanol, 1-butanol, and 1-pentanol reduced the amounts of swelling by 31, 21, 17, and 11 pct, respectively. This was because the small molecule alcohols, which do not dissolve paraffin wax (PW) or stearic acid (SA) in the binder system, could diffuse easily into the specimen and increased the portion of the swelling inhibitor inside. The amount of the extracted PW and SA also decreased, but only by 8.3, 6.1, 4.3, and 2.4 pct, respectively. The solubility parameters of 1-bromopropane (n-PB) and ethyl acetate (EA) are between those of heptane and alcohols, and they also yielded a slight reduction in the amounts of swelling by 6 and 11 pct, respectively. These results suggest that to reduce defects caused by binder swelling during solvent debinding, alcohols with high solubility parameters can be added into heptane without sacrificing significantly on the debinding rate.

  15. Amide-induced phase separation of hexafluoroisopropanol-water mixtures depending on the hydrophobicity of amides.

    Science.gov (United States)

    Takamuku, Toshiyuki; Wada, Hiroshi; Kawatoko, Chiemi; Shimomura, Takuya; Kanzaki, Ryo; Takeuchi, Munetaka

    2012-06-21

    Amide-induced phase separation of hexafluoro-2-propanol (HFIP)-water mixtures has been investigated to elucidate solvation properties of the mixtures by means of small-angle neutron scattering (SANS), (1)H and (13)C NMR, and molecular dynamics (MD) simulation. The amides included N-methylformamide (NMF), N-methylacetamide (NMA), and N-methylpropionamide (NMP). The phase diagrams of amide-HFIP-water ternary systems at 298 K showed that phase separation occurs in a closed-loop area of compositions as well as an N,N-dimethylformamide (DMF) system previously reported. The phase separation area becomes wider as the hydrophobicity of amides increases in the order of NMF amides due to the hydrophobic interaction gives rise to phase separation of the mixtures. In contrast, the disruption of HFIP clusters causes the recovery of the homogeneity of the ternary systems. The present results showed that HFIP clusters are evolved with increasing amide content to the lower phase separation concentration in the same mechanism among the four amide systems. However, the disruption of HFIP clusters in the NMP and DMF systems with further increasing amide content to the upper phase separation concentration occurs in a different way from those in the NMF and NMA systems.

  16. Overexpression, purification, crystallization and preliminary structural studies of p-coumaric acid decarboxylase from Lactobacillus plantarum

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez, Héctor; Rivas, Blanca de las; Muñoz, Rosario [Instituto de Fermentaciones Industriales, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain); Mancheño, José M., E-mail: xjosemi@iqfr.csic.es [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); Instituto de Fermentaciones Industriales, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain)

    2007-04-01

    The enzyme p-coumaric acid decarboxylase (PDC) from L. plantarum has been recombinantly expressed, purified and crystallized. The structure has been solved at 2.04 Å resolution by the molecular-replacement method. The substrate-inducible p-coumaric acid decarboxylase (PDC) from Lactobacillus plantarum has been overexpressed in Escherichia coli, purified and confirmed to possess decarboxylase activity. The recombinant His{sub 6}-tagged enzyme was crystallized using the hanging-drop vapour-diffusion method from a solution containing 20%(w/v) PEG 4000, 12%(w/v) 2-propanol, 0.2 M sodium acetate, 0.1 M Tris–HCl pH 8.0 with 0.1 M barium chloride as an additive. Diffraction data were collected in-house to 2.04 Å resolution. Crystals belonged to the tetragonal space group P4{sub 3}, with unit-cell parameters a = b = 43.15, c = 231.86 Å. The estimated Matthews coefficient was 2.36 Å{sup 3} Da{sup −1}, corresponding to 48% solvent content, which is consistent with the presence of two protein molecules in the asymmetric unit. The structure of PDC has been determined by the molecular-replacement method. Currently, the structure of PDC complexed with substrate analogues is in progress, with the aim of elucidating the structural basis of the catalytic mechanism.

  17. Determination of Lutein and Zeaxanthin Esters and Their Geometric Isomers in Carotenoid Ester Concentrates Used as Ingredients in Nutritional Supplements: Validation of a Combined Spectrophotometric-HPLC Method.

    Science.gov (United States)

    Lombeida, Wagner O; Rubio, Fernando; Levy, Luis W

    2016-11-01

    A combined spectrophotometric-LC method is described for the determination of total lutein and zeaxanthin ester content in carotenoid ester concentrates, including their main geometrical isomers. The concept of composite-specific absorbance is introduced for this purpose. The method is applicable to carotenoid ester concentrates used as ingredients in oil suspensions and dosage forms. The sample is dissolved in a hexane-2-propanol mixture (95 + 5, v/v) for spectrophotometric measurement at a maximum absorption of ~445 nm. Subsequently, in parallel, a sample is saponified and chromatographed on a normal-phase HPLC column to determine the relative percentage profile of the main geometrical isomers of both carotenoid esters. This, in turn, is used to calculate the composite-specific absorbance of the sample for the final calculation of results. The method, which solely uses reference standards to validate chromatographic conditions, avoids the common error of applying the specific absorbance of only the trans isomer for the calculation of total carotenoid content when cis isomers are present.

  18. Industrially benign super-compressible piezoresistive carbon foams with predefined wetting properties: from environmental to electrical applications

    Science.gov (United States)

    Pham, Tung Ngoc; Samikannu, Ajaikumar; Kukkola, Jarmo; Rautio, Anne-Riikka; Pitkänen, Olli; Dombovari, Aron; Lorite, Gabriela Simone; Sipola, Teemu; Toth, Geza; Mohl, Melinda; Mikkola, Jyri-Pekka; Kordas, Krisztian

    2014-11-01

    In the present work electrically conductive, flexible, lightweight carbon sponge materials derived from open-pore structure melamine foams are studied and explored. Hydrophobic and hydrophilic surface properties - depending on the chosen treatment conditions - allow the separation and storage of liquid chemical compounds. Activation of the carbonaceous structures substantially increases the specific surface area from ~4 m2g-1 to ~345 m2g-1, while retaining the original three-dimensional, open-pore structure suitable for hosting, for example, Ni catalyst nanoparticles. In turn the structure is rendered suitable for hydrogenating acetone to 2-propanol and methyl isobutyl ketone as well for growing hierarchical carbon nanotube structures used as electric double-layer capacitor electrodes with specific capacitance of ~40 F/g. Mechanical stress-strain analysis indicates the materials are super-compressible (>70% volume reduction) and viscoelastic with excellent damping behavior (loss of 0.69 +/- 0.07), while piezoresistive measurements show very high gauge factors (from ~20 to 50) over a large range of deformations. The cost-effective, robust and scalable synthesis - in conjunction with their fascinating multifunctional utility - makes the demonstrated carbon foams remarkable competitors with other three-dimensional carbon materials typically based on pyrolyzed biopolymers or on covalently bonded graphene and carbon nanotube frameworks.

  19. Study the interactions between human serum albumin and two antifungal drugs: fluconazole and its analogue DTP.

    Science.gov (United States)

    Zhang, Shao-Lin; Yao, Huankai; Wang, Chenyin; Tam, Kin Y

    2014-11-01

    Binding affinities of fluconazole and its analogue 2-(2,4-dichlorophenyl)-1,3-di(1H-1,2,4-triazol-yl)-2-propanol (DTP) to human serum albumin (HSA) were investigated under approximately human physiological conditions. The obtained result indicated that HSA could generate fluorescent quenching by fluconazole and DTP because of the formation of non-fluorescent ground-state complexes. Binding parameters calculated from the Stern-Volmer and the Scatchard equations showed that fluconazole and DTP bind to HSA with binding affinities of the order 10(4)L/mol. The thermodynamic parameters revealed that the binding was characterized by negative enthalpy and positive entropy changes, suggesting that the binding reaction was exothermic. Hydrogen bonds and hydrophobic interaction were found to be the predominant intermolecular forces stabilizing the drug-protein. The effect of metal ions on the binding constants of fluconazole-HSA complex suggested that the presence of Mg(2+) and Zn(2+) ions could decrease the free drug level and extend the half-life in the systematic circulation. Docking experiments revealed that fluconazole and DTP binds in HSA mainly by hydrophobic interaction with the possibility of hydrogen bonds formation between the drugs and the residues Arg 222, Lys 199 and Lys 195 in HSA.

  20. Continuous electrospinning of polymer nanofibers of Nylon-6 using an atomic force microscope tip.

    Science.gov (United States)

    Gururajan, Giriprasath; Sullivan, S P; Beebe, T P; Chase, D B; Rabolt, J F

    2011-08-01

    An atomic force microscopy (AFM) probe is successfully utilized as an electrospinning tip for fabricating Nylon-6 nanofibers. The nanometre-size tip enabled controlled deposition of uniform polymeric nanofibers within a 1 cm diameter area. Nylon-6 nanofibers were continuously electrospun at a solution concentration as low as 1 wt% Nylon-6 in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). Wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) results of the AFM electrospun fibers indicated that the nanofibers predominantly display the meta-stable γ crystalline form suggesting rapid crystallization rate during the process. In addition to precise control over fiber deposition and diameter, some of the drawbacks of conventional electrospinning such as large volume of solutions and clogging of needles can be overcome using this AFM based electrospinning technique. Lastly, a comparison of electrospun fibers from syringe-needle based electrospinning and AFM probe-tip based electrospinning indicated significant morphological and microstructural differences in the case of AFM based electrospinning.

  1. Insight into the structural deformations of beta-cyclodextrin caused by alcohol cosolvents and guest molecules.

    Science.gov (United States)

    Zhang, Haiyang; Ge, Chunling; van der Spoel, David; Feng, Wei; Tan, Tianwei

    2012-03-29

    Beta-cyclodextrin (β-CD) is an ideal candidate for a host molecule, and it is used as such in drug delivery and separation technology. The structural behavior of free β-CD and host-guest complexes of β-CD with two isoflavonoid isomers (puerarin and daidzin) in aqueous alcohol solutions, covering methanol, ethanol, 2-propanol, and 1-propanol, was investigated through molecular dynamics (MD) simulations. The MD results highlighted aspects of the structural flexibility and rigidity of β-CD in different alcohol solutions. The alcohol residence time within the β-CD cavity, solvent distribution around β-CD, and guest-induced structural changes were analyzed. Interaction with puerarin endowed β-CD with a more rigid structure than with daidzin and a weaker ternary complex β-CD/puerarin/alcohol was formed with a local participation of water molecules. The retention behavior of puerarin and daidzin on a β-CD-coupled medium was determined via chromatographic experiments and simulation results provided a structural explanation for such interactions.

  2. A fiber-optic sensor to detect volatile organic compounds based on a porous silica xerogel film.

    Science.gov (United States)

    Echeverría, Jesús C; de Vicente, Pablo; Estella, Juncal; Garrido, Julián J

    2012-09-15

    Fiber-optic sensors are increasingly used for the determination of volatile organic compounds (VOCs) in air matrices. This paper provides experimental results on the sensitivity of a fiber-optic sensor that uses a film of a porous silica xerogel as the sensing element. This film was synthesized by the sol-gel process and affixed to the end of the optical fiber by the dip-coating technique. This intrinsic sensor works in reflection mode, and the transduction takes place in the light that travels through the core of the fiber. The VOCs included in this research cover a wide range of compounds with different functional groups and polarities. The highest sensitivity was for 2-propanol (13.1±1.4 M(-1) nm(-1)), followed by toluene (11.4±1.4 M(-1) nm(-1)), and 1-butylamine (9.5±0.4 M(-1) nm(-1)). Acetone and cyclohexane had the lowest sensitivity of all studied VOCs. Limits of detection varied between 9.1×10(-5) M for 1-butylamine and 1.6×10(-3) M for ethanol. Silanol groups on the xerogel surface act as weak acids and interact strongly with molecules that contain OH groups like alcohols, π-electrons like toluene, or a lone pair of electrons like toluene. Stronger interaction of methanol and ethanol with the silanol groups on the film led to some irreversible adsorption of these analytes at room temperature.

  3. VGF and striatal cell damage in in vitro and in vivo models of Huntington's disease.

    Science.gov (United States)

    Noda, Yasuhiro; Shimazawa, Masamitsu; Tanaka, Hirotaka; Tamura, Shigeki; Inoue, Teruyoshi; Tsuruma, Kazuhiro; Hara, Hideaki

    2015-06-01

    Huntington's disease (HD) is an inherited genetic disorder, characterized by cognitive dysfunction and abnormal body movements, and at present there is no effective treatment for HD. Therapeutic options for HD are limited to symptomatic treatment approaches and there is no cure for this devastating disease. Here, we examined whether SUN N8075, (2S)-1-(4-amino-2,3,5-trimethylphenoxy)-3-{4-[4-(4-fluorobenzyl)phenyl]-1-piperazinyl}-2-propanol dimethanesulfonate, which exerts neuroprotective effects by antioxidant effects and induction of VGF nerve growth factor inducible (VGF), has beneficial effects in STHdh cells derived from striatum of knock-in HD mice and R6/2 HD mice. In an in vitro study, SUN N8075 inhibited the cell death caused by mutant huntingtin (mHtt) and upregulated the VGF mRNA level via the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). Furthermore, 30 amino acid of VGF C-terminal peptide, AQEE-30 inhibited the cell death and the aggregation of mHtt. In an in vivo study, SUN N8075 improved the survival and the clasping response in the R6/2 mice. Furthermore, SUN N8075 increased the number of surviving neurons in the striatum of the R6/2 mice. These findings suggest that SUN N8075 may be an effective candidate for HD treatments.

  4. Fotólise no estado estacionário e com pulso de laser de 1-benzociclanonas e de seus derivados a,a -dimetilados Steady-state and laser flash photolysis of 1 - benzocyclanones and their a,a -dimethyl derivatives

    Directory of Open Access Journals (Sweden)

    José Carlos Netto-Ferreira

    1999-07-01

    Full Text Available Laser excitation of 0.01 M solutions of 1-indanone (Ia, 1-tetralone (Ib, 1-benzosuberone (Ic, and their a,a -dimethyl derivatives IIa-c, respectively, in benzene, produced transients with maximum absorption at 425 nm, and lifetimes ranging from 62 ns (IIa to 5.5ms (Ic. Quenching studies using well known triplet quenchers such as 1,3-cyclohexadiene and oxygen demonstrated the triplet nature of these transients. In the presence of hydrogen donors, such as 2-propanol, the triplet state decay of the ketones Ia-c leads to the formation of the corresponding ketyl radicals, i.e. IIIa-c, which show absorption spectra very similar to the parent ketone, with lmax at 430 nm and lifetime in excess of 20 ms. Steady state irradiations show that the a,a -dimethyl ketones IIa and IIc form ortho-alkyl benzaldehydes probably derived from an initial a-cleavage of the corresponding triplet excited states.

  5. Determination and Correlation of Solubilities of Four Novel Benzothiazolium Ionic Liquids with 6PF- in Six Alcohols

    Institute of Scientific and Technical Information of China (English)

    何志坚; 王小敏; 姚田; 宋航; 姚舜

    2014-01-01

    Four novel benzothiazolium ionic liquids with 6PF- ([C1Bth][PF6], [C4Bth][PF6], [C5Bth][PF6] and [C6Bth][PF6]) were synthesized, and the rang of their melting points were determined between 358.35 K-424.05 K. The relationship of their melting points and the length of the straight alkyl chain on cation reflected‘S’ type ten-dency. Then, the solubilities of the four ionic liquids in six lower alcohols (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-methyl-1-propanol) were measured in the temperature rang of 253.15-383.15 K at at-mospheric pressure with static analytical method, respectively. It was found that [C6Bth][PF6] in all investigated ionic liquids had the largest solubility in six alcohols and the solubility of [C4Bth][PF6] in methanol was very sensi-tive for temperature in 313.15-333.15 K, which was so-called “temperature-sensitivity”. This feature is of great significance to their application of catalyzing reaction or extraction process, and makes the recovery and reuse of ionic liquids (ILs) become easier. Moreover, the experimental solubility data were correlated with the modified Apelblat equation andλh equation, respectively. It was found that the result of correlation using two divided tem-perature ranges was better than that of using the whole temperature range.

  6. Synthesis and pervaporation performance of high-reproducibility silicalite-1 membranes

    Institute of Scientific and Technical Information of China (English)

    CHEN HongLiang; LI YanShuo; Zhu GuangQi; LIU Jie; YANG WeiShen

    2008-01-01

    High-reproducibility silicalite-1 membranes were synthesized on silica tubes by in-situ hydrothermal synthesis, and the relative standard deviation (R.S.D.) of average separation factor for eight membranes was only 7.5%. By using an effective method called "solution-filling (SF)", the average flux of membranes prepared with SF method was improved by about 49% compared to membranes prepared without SF method, and the highest flux of membrane prepared with SF method towards ethanol/H2O mixture at 80℃ was 1.49 kg/(m2·h). Pervaporation experiments showed that the fluxes of silicalite-1 membranes at 60℃ were 2.63, 0.87, 0.24, and 0.20 kg/(m2·h) towards methanol/H2O, ethanol/H2O,2-propanol/H2O, and 1-propanol/H2O mixtures, respectively, and the corresponding separation factors were 22, 69, 81, and159, respectively.

  7. Polycaprolactone-Chitin Nanofibrous Mats as Potential Scaffolds for Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Min Sup Kim

    2012-01-01

    Full Text Available We describe here the preparation of poly(caprolactone (PCL-chitin nanofibrous mats by electrospinning from a blended solution of PCL and chitin dissolved in a cosolvent, 1,1,1,3,3,3-hexafluoro-2-propanol and trifluoroacetic acid. Scanning electron microscopy showed that the neutralized PCL-chitin nanofibrous mats were morphologically stable, with a mean diameter of 340.5±2.6 nm, compared with a diameter of 524.2±12.1 nm for PCL mats. The nanofibrous mats showed decreased water contact angles as the proportion of chitin increased. However, the tensile properties of nanofibrous mats containing 30~50% (wt/wt chitin were enhanced compared with PCL-only mats. In vitro studies showed that the viability of human dermal fibroblasts (HDFs for up to 7 days in culture was higher on composite (OD value: 1.42±0.09 than on PCL-only (0.51±0.14 nanofibrous mats, with viability correlated with chitin concentration. Together, our results suggest that PCL-chitin nanofibrous mats can be used as an implantable substrate to modulate HDF viability in tissue engineering.

  8. Synthesis and application of a bidentate ligand based on decafluoro-3-phenyl-3-pentanol: steric effect of pentafluoroethyl groups on the stereomutation of O-equatorial C-apical spirophosphoranes.

    Science.gov (United States)

    Jiang, Xin-Dong; Kakuda, Ken-ichiro; Matsukawa, Shiro; Yamamichi, Hideaki; Kojima, Satoshi; Yamamoto, Yohsuke

    2007-02-05

    1,1,1,2,2,4,4,5,5,5-Decafluoro-3-phenyl-3-pentanol was prepared by a Cannizzaro-type disproportionation reaction, and the dimetallated compound was used as a bidentate ligand, which is bulkier than the Martin ligand (1,1,1,3,3,3-hexafluoro-2-phenyl-2-propanol). A P-H spirophosphorane was synthesized by utilizing the new bidentate ligand, and the structure of the product was essentially the same as that of the P-H phosphorane with Martin ligands. Phosphoranes that exhibit reversed apicophilicity (O-equatorial) were also synthesized and could be converted into the corresponding stable stereoisomers (O-apical). The crystal structures of O-equatorial phosphoranes and the O-apical isomers were slightly affected by the steric repulsion of pentafluoroethyl groups. Kinetic measurements revealed that the stereomutation of O-equatorial methylphosphorane to the O-apical isomer was slowed. The activation enthalpy for the stereomutation of the former to the latter was higher than that of the phosphorane with Martin ligands by 5.1 kcal mol(-1).

  9. Authentication of fattening diet of Iberian pigs according to their volatile compounds profile from raw subcutaneous fat.

    Science.gov (United States)

    Narváez-Rivas, M; Pablos, F; Jurado, J M; León-Camacho, M

    2011-02-01

    The composition of volatile components of subcutaneous fat from Iberian pig has been studied. Purge and trap gas chromatography-mass spectrometry has been used. The composition of the volatile fraction of subcutaneous fat has been used for authentication purposes of different types of Iberian pig fat. Three types of this product have been considered, montanera, extensive cebo and intensive cebo. With classification purposes, several pattern recognition techniques have been applied. In order to find out possible tendencies in the sample distribution as well as the discriminant power of the variables, principal component analysis was applied as visualisation technique. Linear discriminant analysis (LDA) and soft independent modelling by class analogy (SIMCA) were used to obtain suitable classification models. LDA and SIMCA allowed the differentiation of three fattening diets by using the contents in 2,2,4,6,6-pentamethyl-heptane, m-xylene, 2,4-dimethyl-heptane, 6-methyl-tridecane, 1-methoxy-2-propanol, isopropyl alcohol, o-xylene, 3-ethyl-2,2-dimethyl-oxirane, 2,6-dimethyl-undecane, 3-methyl-3-pentanol and limonene.

  10. Close correlation between heat shock response and cytotoxicity in Neurospora crassa treated with aliphatic alcohols and phenols

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, U.; Schweim, P.; Fracella, F.; Rensing, L. [Univ. of Bremen (Germany)

    1995-03-01

    In Neurospora crassa the aliphatic alcohols methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, ethylene glycol, glycerol, and allyl alcohol and the phenolic compounds phenol, hydroquinone, resorcinol, pyrogallol, phloroglucinol, sodium salicylate, and acetylsalicylic acid were analyzed with respect to their capacities to induce heat shock proteins (HSP) and to inhibit protein synthesis. Both the alcohols and phenols showed the greatest levels of HSP induction at concentrations which inhibited the overall protein synthesis by about 50%. The abilities of the different alcohols to induce the heat shock response are proportional to their lipophilicities: the lipophilic alcohol isobutanol is maximally inductive at about 0.6 M, whereas the least lipophilic alcohol, methanol, causes maximal induction at 5.7 M. The phenols, in general, show a higher capability to induce the heat shock response. The concentrations for maximal induction range between 25 mM (sodium salicylate) and 100 mM (resorcinol). Glycerol (4.1 M) shifted the concentration necessary for maximal HSP induction by hydroquinone from 50 to 200 mM. The results reveal that the induction of HSP occurs under conditions which considerably constrain cell metabolism. The heat shock response, therefore, does not represent a sensitive marker for toxicity tests but provides a good estimate for the extent of cell damage.

  11. Sensitive high-performance liquid chromatographic quantitation of gabapentin in human serum using liquid-liquid extraction and pre-column derivatization with 9-fluorenylmethyl chloroformate.

    Science.gov (United States)

    Bahrami, Gholamreza; Kiani, Amir

    2006-05-01

    Most of the published methods for analysis of gabapentin, an antiepileptic agent, in human serum are based on the same approach, involving o-phthaldialdehyde derivatization of deproteinized serum samples. The present paper however, describes a new, simple and sensitive high-performance liquid chromatographic method for determination of gabapentin in human serum using liquid-liquid extraction and 9-fluorenylmethyl chloroformate (FMOC-Cl) as pre-column labeling agent. The drug and an internal standard (azithromycin) were extracted from serum by salting-out approach using a mixture of dichloromethane-2 propanol (1:1, v/v) as the extracting solvent. The extracted analytes were subjected to derivatization with FMOC-Cl in the presence of phosphate buffer (pH 7). A mobile phase consisting of methanol-0.05 M sodium phosphate buffer (73/27, v/v; pH of 3.9) containing 1 ml/l triethylamine was eluted and chromatographic separation was performed on a Shimpack CLC-C18 (150 mm x 4.6 mm) column. The standard curve was linear over the range of 0.03-20 microg/ml and limit of quantification was 0.03 microg/ml. The performance of analysis was studied and the validated method showed excellent performance in terms of selectivity, specificity, sensitivity, precision and accuracy. No interferences were found from commonly co-administered antiepileptic agents.

  12. A Simple Method of Obtaining Spherical Nanosilica from Rice Husk

    Directory of Open Access Journals (Sweden)

    Mohammed Noushad

    2012-01-01

    Full Text Available This paper describes the synthesis of nanosilica from rice husk. Synthesis was done by precipitation using different acids, namely, orthophosphoric acid and nitric acid which yielded nanosilica. The effect of different acids and different solvents (polar and non-polar on the size and degree of agglomeration of the silica particles were studied. When precipitation was done without the use of solvents, the silica particles  obtained were non-spherical in shape, whereas, when precipitation was done using polar solvents (ethanol or 2-propanol, the silica particles were spherical. The use of non-polar solvents (toluene and diethyl ether resulted in silica particles that were irregular in shape and in the case of orthophosphoric acid, a high degree of agglomeration was also noted. The degree of agglomeration was less when orthophosphoric acid was used with polar solvents as compared to nitric acid in conjunction with polar solvents. As regards the size, it ranged from approximately 70nm to 400nm when either acid was used in conjunction with polar solvents. When non-polar solvents were used, the silica particles were irregular in shape and the particle size was not estimated.

  13. Chiral separation of a diketopiperazine pheromone from marine diatoms using supercritical fluid chromatography.

    Science.gov (United States)

    Frenkel, Johannes; Wess, Carsten; Vyverman, Wim; Pohnert, Georg

    2014-03-01

    The proline derived diketopiperazine has been identified in plants, insects and fungi with unknown function and was recently also reported as the first pheromone from a diatom. Nevertheless the stereochemistry and enantiomeric excess of this natural product remained inaccessible using direct analytical methods. Here we introduce a chiral separation of this metabolite using supercritical fluid chromatography/mass spectrometry. Several chromatographic methods for chiral analysis of the diketopiperazine from the diatom Seminavis robusta and synthetic enantiomers have been evaluated but neither gas chromatography nor high performance liquid chromatography on different chiral cyclodextrin phases were successful in separating the enantiomers. In contrast, supercritical fluid chromatography achieved baseline separation within four minutes of run time using amylose tris(3,5-dimethylphenylcarbamate) as stationary phase and 2-propanol/CO2 as mobile phase. This very rapid chromatographic method in combination with ESI mass spectrometry allowed the direct analysis of the cyclic dipeptide out of the complex sea water matrix after SPE enrichment. The method could be used to determine the enantiomeric excess of freshly released pheromone and to follow the rapid degradation observed in diatom cultures. Initially only trace amounts of c(d-Pro-d-Pro) were found besides the dominant c(l-Pro-l-Pro) in the medium. However the enantiomeric excess decreased upon pheromone degradation within few hours indicating that a preferential conversion and thus inactivation of the l-proline derived natural product takes place.

  14. Expression, purification, crystallization and preliminary X-ray analysis of the PaaI-like thioesterase SAV0944 from Staphylococcus aureus.

    Science.gov (United States)

    Khandokar, Yogesh B; Roman, Noelia; Smith, Kate M; Srivastava, Parul; Forwood, Jade K

    2014-02-01

    Staphylococcus aureus is the causative agent of many diseases, including meningitis, bacteraemia, pneumonia, food poisoning and toxic shock syndrome. Structural characterization of the PaaI-like thioesterase SAV0944 (SaPaaI) from S. aureus subsp. aureus Mu50 will aid in understanding its potential as a new therapeutic target by knowledge of its molecular details and cellular functions. Here, the recombinant expression, purification and crystallization of SaPaaI thioesterase from S. aureus are reported. This protein initially crystallized with the ligand coenzyme A using the hanging-drop vapour-diffusion technique with condition No. 40 of Crystal Screen from Hampton Research at 296 K. Optimal final conditions consisting of 24% PEG 4000, 100 mM sodium citrate pH 6.5, 12% 2-propanol gave single diffraction-quality crystals. These crystals diffracted to beyond 2 Å resolution at the Australian Synchrotron and belonged to space group P12(1)1, with unit-cell parameters a = 44.05, b = 89.05, c = 60.74 Å, β = 100.5°. Initial structure determination and refinement gave an R factor and R(free) of 17.3 and 22.0%, respectively, confirming a positive solution in obtaining phases using molecular replacement.

  15. Dechlorination of polychlorinated biphenyls in industrial transformer oil by radiolytic and photolytic methods.

    Science.gov (United States)

    Jones, Cynthia G; Silverman, Joseph; Al-Sheikhly, Mohamad; Neta, Pedatsur; Poster, Dianne L

    2003-12-15

    Used electrical transformer oils containing low or high concentrations of polychlorinated biphenyls (PCBs) were treated using electron, gamma, and ultraviolet radiation, and the conditions for complete dechlorination were developed. Dechlorination was determined by analysis of the inorganic chloride formed and the concentrations of remaining PCBs. Transformer oil containing approximately 95 microg g(-1) PCB (approximately 3.5 mmol L(-1) Cl) is completely dechlorinated by irradiation with 600 kGy after the addition of 10% triethylamine (TEA). Transformer oil containing >800,000 microg g(-1) PCB (17.7 mol L(-1) Cl) requires an additional solvent to prevent solidification. When this oil is diluted with 2-propanol (2-PrOH) and TEA (v/v/v, 1/79/20), complete dechlorination is achieved with a dose of 2500 kGy. Ultraviolet photolysis of the same oil/2-PrOH/TEA solutions led to 90% dechlorination after exposure for 120 h in our experimental setup. Such yields were obtained by radiolysis with a dose of 2000 kGy (300 h in our Gammacell). Replacing TEA with KOH in 2-PrOH solutions greatly increases the yield of dechlorination in both the radiolytic and the photolytic experiments, demonstrating that a chain reaction plays a role in both of these treatment methods and suggesting that both methods deserve further consideration for large-scale application.

  16. Preparation, structural and morphological studies of Ni doped titania nanoparticles.

    Science.gov (United States)

    Rajamannan, B; Mugundan, S; Viruthagiri, G; Shanmugam, N; Gobi, R; Praveen, P

    2014-07-15

    TiO2 nanoparticles doped with different weight percentages (4%, 8%, 12% and 16%) of nickel contents were prepared by a modified sol-gel method using Titanium tetra iso propoxide and nickel nitrate as precursors and 2-propanol as a solvent. X-ray diffraction studies show that the as prepared and annealed products show anatase structure with average particle sizes running between of 8 and 16 nm. FTIR results demonstrate the presence of strong chemical bonding at the interface of TiO2 nanoparticles. The optical properties of bare and doped samples were carried out using UV-DRS and photoluminescence measurements. The surface morphology and the element constitution of the nickel doped TiO2 nanoparticles were studied by scanning electron microscope attached with energy dispersive X-ray spectrometer arrangement. The non linear optical properties of the products were confirmed by Kurtz second harmonic generation (SHG) test and the output power generated by the nanoparticle was compared with that of potassium di hydrogen phosphate (KDP).

  17. Dithiol-mediated incorporation of CdS nanoparticles from reverse micellar system into Zn-doped SBA-15 mesoporous silica and their photocatalytic properties.

    Science.gov (United States)

    Hirai, Takayuki; Nanba, Masanori; Komasawa, Isao

    2003-12-15

    CdS nanoparticles, as prepared in reverse micellar systems, were incorporated into alkanedithiol-modified Zn-doped SBA-15 mesoporous silica (dtz.sbnd;ZnSBA-15; pore diameter, ca. 4 nm), which were themselves prepared via hydrolysis of tetraethylorthosilicate (TEOS) in the presence of Zn(NO(3))(2) and triblock copolymer, as a nonsurfactant template and pore-forming agent, followed by contact with dithiol molecules. A particle-sieving effect for the dtz.sbnd;ZnSBA-15 was observed, in that the incorporation of the nanoparticles was remarkably decreased with increasing the nanoparticle size. The resulting CdSz.sbnd;ZnSBA-15 composite was then used as photocatalysts for the generation of H(2) from 2-propanol aqueous solution. Under UV irradiation (lambda>300 nm), a high photocatalytic activity was observed for this composite material. This is effected by electron transfer from the photoexcited ZnS (dithiol-bonded Zn on SBA-15) to CdS nanoparticles. The photocatalytic activity is increased with a decrease in the number of methylene groups in the dithiol molecules, according to the rank order 1,10-decanedithiol < 1,6-hexanedithiol < 1,2-ethanedithiol.

  18. Asymmetric Hydrogenation of Ketones-Design of Chiral Catalysts

    Institute of Scientific and Technical Information of China (English)

    Takeshi Ohkuma

    2005-01-01

    @@ 1Introduction Asymmetric hydrogenation of ketones is one of the most reliable methods for obtaining chiral secondary alcohols. This transformation is not only of academic interest, but also of industrial significance because of its simplicity, environmental friendliness, and economic viability. Chiral RuXY(binap)(1,2-diamine) complexes (BINAP = 2,2'-bis(diphenyl-phosphino)-1, 1'-binaphthyl,X = Y = C1 or X = H, Y = BH4) with[1] or without[2] a strong base catalyze rapid, highly productive asymmetric hydrogenation of various simple ketones in 2-propanol. This reaction, unlike conventional hydrogenation, proceeds selectively at a C = O bond leaving coexisting C = C linkages intact. A range of chiral alcohols are accessible in high enantiomeric purity from aromatic,heteroaromatic, olefinic, and amino ketones by this method[1,2]. However, no universal chiral catalysts exist due to the structural diversity of ketonic substrates. Thus, tert-alkyl ketones and 1-tetralones have remained difficult to be hydrogenated with high reactivity and enantioselectivity. We here report that this problem can be resolved by the use of BINAP/PICA-Ru (PICA = α-picolylamine)[3] or BINAP/1,4-diamine-Ru[4] complexes as catalysts.

  19. Anion effect on the binary and ternary phase diagrams of chiral medetomidine salts and conglomerate crystal formation.

    Science.gov (United States)

    Choobdari, Ebrahim; Fakhraian, Hossein; Peyrovi, Mohammad Hassan

    2014-03-01

    The binary phase diagrams of hydrogen halides salts of medetomidine (Med.HX, X:Br,I) and hydrogen oxalate salt of medetomidine (Med.Ox) were determined based on thermogravimetric/differential thermal analysis (TGA/DTA) and their crystal structure behavior was confirmed by comparison of the X-ray diffractometry and FT-IR spectroscopy of the racemate and pure enantiomer. All hydrogen halide salts presented racemic compound behavior. Heat of fusion of halides salt of (rac)-medetomidine decreased with ionic radius increase. Eutectic points for Med.HCl (previously reported), Med.HBr, and Med.HI rest were unchanged approximately. The solubility of different enantiomeric mixtures of Med.HBr and Med.HI were measured at 10, 20, and 30°C in 2-propanol showing a solubility increase with ionic radius. A binary phase diagram of Med.Ox shows a racemic conglomerate behavior. The solubility of enantiomeric mixtures of Med.Ox were measured at 10, 20, 30, and 40°C. The ternary phase diagram of Med.Ox in ethanol conforms to a conglomerate crystal forming system, favoring its enantiomeric purification by preferential crystallization.

  20. Microemulsion System for Topical Delivery of Thai Mango Seed Kernel Extract: Development, Physicochemical Characterisation and Ex Vivo Skin Permeation Studies

    Directory of Open Access Journals (Sweden)

    Jiraporn Leanpolchareanchai

    2014-10-01

    Full Text Available A microemulsion system containing Thai mango seed kernel extract (MSKE, cultivar “Fahlun” was developed and characterised for the purpose of topical skin delivery. The MSKE-loaded microemulsions were prepared by using the spontaneous emulsification method. Isopropyl myristate (IPM was selected as the oil phase. A polyoxyethylene sorbitan monooleate and sorbitan monododecanoate (1:1, w/w system was used as the surfactant phase; an aqueous mixture of different cosurfactants (absolute ethanol, 96.3% v/v ethanol, 1-propanol, 2-propanol or 1,2-propanediol at a weight ratio of 1:1 was used as the aqueous phase. Among the cosurfactants studied, the 1-propanol aqueous mixture had the largest microemulsion region (48.93% in the pseudo-ternary phase diagram. Microemulsions containing 1% MSKE demonstrated good physicochemical stability during a six-month study period at 25 ± 2 °C/60% ± 5% RH. The ex vivo skin permeation study demonstrated that the microemulsions exhibited a potent skin enhancement effect allowing MSKE to penetrate skin layers up to 60-fold higher compared with the control. Neither skin irritation nor skin corrosion was observed in ex vivo studies. The present study revealed that IPM-based microemulsion systems may be promising carriers to enhance skin penetration and delivering MSKE for topical treatment.

  1. Purification of pectinase from mango (Mangifera indica L. cv. Chokanan) waste using an aqueous organic phase system: a potential low cost source of the enzyme.

    Science.gov (United States)

    Amid, Mehrnoush; Abdul Manap, Mohd Yazid; Mustafa, Shuhaimi

    2013-07-15

    As a novel method of purification, an aqueous organic phase system (AOPS) was employed to purify pectinase from mango waste. The effect of different parameters, such as the alcohol concentration (ethanol, 1-propanol, and 2-propanol), the salt type and concentration (ammonium sulfate, potassium phosphate and sodium citrate), the feed stock crude load, the aqueous phase pH and NaCl concentration, were investigated in the recovery of pectinase from mango peel. The partition coefficient (K), selectivity (S), purification factor (PF) and yield (Y, %) were investigated in this study as important parameters for the evaluation of enzyme recovery. The desirable partition efficiency for pectinase purification was achieved in an AOPS of 19% (w/w) ethanol and 22% (w/w) potassium phosphate in the presence of 5% (w/w) NaCl at pH 7.0. Based on the system, the purification factor of pectinase was enhanced 11.7, with a high yield of 97.1%.

  2. Controlling the morphology of thin titania films for applications in hybrid solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rawolle, Monika; Ruderer, Matthias A.; Prams, Stefan; Zhong, Qi; Mueller-Buschbaum, Peter [TU Muenchen, Physik-Department LS E13, Garching (Germany); Memesa, Mine; Gutmann, Jochen S. [Max-Planck Institute for Polymer Research, Mainz (Germany)

    2010-07-01

    Nanostructured thin films of titania have a variety of applications. For applications in photovoltaics a high absorption coefficient and a large surface area are desirable. A sponge structure is a promising morphology for titania to meet these demands. Block copolymers can be used in a good-poor solvent pair induced phase separation process coupled with sol-gel chemistry to create structured titania films in a reproducible way. We use the amphiphilic diblock copolymer Poly(dimethyl siloxane)-block-methyl methacrylate poly(ethylene oxide)[PDMS-b-MA(PEO)] as templating agent. Different well defined mixing procedures of sol-gel components (Tetrahydrofuran, 2-Propanol, HCl and titania precursor in addition to the PDMS-b-MA(PEO)) of same weight fractions result in small changes in the morphology of the film. The thin films are prepared via spin-coating on silicon substrates. The surface structure is studied with SEM. Information on the morphology in the volume of the film is gained from GISAXS. The layer thickness and structure are studied with XRR, the optical properties with UV/Vis spectroscopy.

  3. Enantioseparation of pyroglutamide derivatives on polysaccharide based chiral stationary phases by high-performance liquid chromatography and supercritical fluid chromatography: a comparative study.

    Science.gov (United States)

    Baudelet, Davy; Schifano-Faux, Nadège; Ghinet, Alina; Dezitter, Xavier; Barbotin, Florent; Gautret, Philippe; Rigo, Benoit; Chavatte, Philippe; Millet, Régis; Furman, Christophe; Vaccher, Claude; Lipka, Emmanuelle

    2014-10-10

    Analytical enantioseparation of three pyroglutamide derivatives with pharmacological activity against the purinergic receptor P2X7, was run in both high-performance liquid chromatography and supercritical fluid chromatography. Four polysaccharide based chiral stationary phases, namely amylose and cellulose tris (3,5-dimethylphenylcarbamate), amylose tris ((S)-α-methylbenzylcarbamate) and cellulose tris (4-methylbenzoate) with various mobile phases consisted of either heptane/alcohol (ethanol and 2-propanol) or carbon dioxide/alcohol (methanol or ethanol) mixtures, were investigated. After analytical screenings, the best conditions were transposed, for compound 1, to semi-preparative scale. Each approach was fully validated to meet the International Conference on Harmonisation requirements and compared. Whereas the limits of detection and quantification were near six-fold better in HPLC than in SFC (respectively 0.20 and 0.66 μM versus 1.11 and 3.53 μM for one of the enantiomers), in terms of low solvent consumption (7.2 mL of EtOH versus 3.2 mL of EtOH plus 28.8 mL of toxic and inflammable heptane per injection in SFC and HPLC, respectively), time effective cost (9 min versus 40 min per injection in SFC and HPLC, respectively) and yields (98% versus 71% in SFC and HPLC, respectively), the latter method proved its ecological superiority.

  4. Formation of H3O+ from alcohols and ethers induced by intense laser fields.

    Science.gov (United States)

    Shirota, Tatsuro; Mano, Narutoshi; Tsuge, Masashi; Hoshina, Kennosuke

    2010-03-15

    The processes of H(3)O(+) production from alcohols (ethanol, 2-propanol, 1-propanol, 2-butanol) and ethers (diethyl ether and ethyl methyl ether), and their deuterium-substituted species, by intense laser fields (800 nm, 100 fs, approximately 1 x 10(14) W/cm) were investigated through time-of-flight (TOF) mass spectrometry. H(3)O(+) formation was observed for all these compounds except for ethyl methyl ether. From the analysis of TOF signals of H((3-n))D(n)O(+) (n = 0, 1, 2, and 3) that have expanding tails with increasing flight time, it has been confirmed that the reaction proceeds through metastable dissociation from the intermediate species C(2)H((5-m))D(m)O(+)(m = 0-5). The common shape of the H((3-n))D(n)O(+) signal profiles contains two major distributions in the time constant, i.e., fast and slow components of production. Ab initio calculations for the isomers and transition states of C(2)H(5)O(+) were also performed, and the observed H((3-n))D(n)O(+) production mechanism has been discussed. In addition, a stable isomer having a complex structure and two isomerization pathways were discovered to contribute to the H(3)O(+) formation process.

  5. Synthesis and characterization of undoped and cobalt-doped TiO2 nanoparticles via sol-gel technique

    Science.gov (United States)

    Mugundan, S.; Rajamannan, B.; Viruthagiri, G.; Shanmugam, N.; Gobi, R.; Praveen, P.

    2015-04-01

    TiO2 nanoparticles doped with different concentrations of cobalt (4, 8, 12 and 16 %) were synthesized by sol-gel method at room temperature with appropriate reactants. In general, TiO2 can exist in anatase, rutile, and brookite phases. In this present study, we used titanium tetra iso propoxide and 2-propanol as a common starting materials and the obtained products were calcined at 500 °C and 800 °C to get anatase and rutile phases, respectively. The crystalline sizes of the doped and undoped TiO2 nanoparticles were observed with X-ray diffraction (XRD) analysis. The functional groups of the samples were identified by Fourier transform infrared spectroscopy (FTIR). From UV-VIS diffuse reflectance spectra (DRS), the band gap energy and excitation wavelength of doped and undoped TiO2 nanoparticles were identified. The defect oriented emissions were seen from photoluminescence (PL) study. The spherical uniform size distribution of particles and elements present in the samples was determined using two different techniques viz., scanning electron microscopy (SEM) with energy-dispersive spectrometer (EDX) and transmission electron microscope (TEM) with selected area electron diffraction (SAED) pattern. The second harmonic generation (SHG) efficiency was also found and the obtained result was compared with potassium di hydrogen phosphate (KDP).

  6. COPPER(0)-MEDIATED RADICAL POLYMERIZATION OF STYRENE AT ROOM TEMPERATURE

    Institute of Scientific and Technical Information of China (English)

    Xiao-fei Zhang; Yang Wu; Jun Huang; Xue-lang Miao; Zheng-biao Zhang; Xiu-lin Zhu

    2013-01-01

    The "living'/controlled radical polymerization (LRP) of styrene (St) at room temperature is rarely reported.In this work,copper(0) (Cu(0))-mediated radical polymerization of St at room temperature was investigated in detail.Dimethyl sulfoxide (DMSO),N,N-dimethylformamide (DMF) as well as a binary solvent,tetrahydrofuran/1,1,1,3,3,3-hexafluoro-2-propanol were used as the solvents,respectively.Methyl-2-bromopropionate and ethyl 2-bromoisobutyrate were used as the initiators,respectively.The polymerization proceeded smoothly with moderate conversions at room temperature.It was found that DMF was a good solvent with the essential features of LRP,while DMSO was a poor solvent with uncontrollable molecular weights.Besides,the match among the initiator,solvent and molar ratios of reactants can modulate the livingness of the polymerization,and the proper selection of ligand was also crucial to a controlled process.This work provided a first example of Cu(0)-mediated radical polymerization of St at room temperature,which would enrich and strength the LRP technique.

  7. COMPARISON OF PERFORMANCE PIEZO RESONATORS BAW-TYPE TO CREATE CHEMICAL SENSOR

    Directory of Open Access Journals (Sweden)

    T. A. Kuchmenko

    2014-01-01

    Full Text Available Summary. Currently creation of small inexpensive analytical devices is very actual. Possibility of miniaturization vibrational gas sensors is associated with the possibility of using resonators smaller than the traditionally used sizes. The study used two types of sensors: sensors based on BAW resonators brand RK 169 with frequency of self-oscillation of 10 MHz and a mini - sensors, resonators based on BAW resonators brand MBC 10000 and MBC 15000 with frequencies of self-oscillation of 10 and 15 MHz respectively. As modifier of electrodes polyethylene glycol PEG 2000 was used. Check of sensitivity of microbalance and evaluation other performance properties of sensors was carried in pairs chloroform, 2-propanol and benzene. Mini -sensor has a smaller surface available sorption, whereby mini-sesors have a smaller analytical signal as compared traditional used resonators. Mass of coating which cause failure of self-oscillation for mini -sensors does not exceed 3 mcg and it is much smaller than for traditionally used sensors. It has been established that the analytical signal of mini-sensors in pairs of test compounds is higher than analytical signal of traditionally used sensors. Analytical signal is more for sensors with higher mass of coating and for sensors with higher selfoscillation frequency. The study found that the mini-sensors can be used for a narrow range of problems in the analysis. the sensitivity of mini-sensors is higher than that traditionally used sensors, but they have significant limitations on weight of coating.

  8. Efeito de Botrytis cinerea na composição do vinho Gewürztraminer Effect of Botrytis cinerea on the composition of Gewürztraminer wine

    Directory of Open Access Journals (Sweden)

    Julio Meneguzzo

    2006-09-01

    were density, alcohol, total and volatile acidity, dry extract, reduced dry extract, reducing sugars, alcohol in weight/reduced dry extract ratio, ashes, alcalinity of ashes, color (I 420, total polyphenols (I 280, total N, glycerol, gluconic acid, minerals (P, K, Ca, Mg, Na, Mn, Fe, Cu, Zn, Rb, Li, volatile compounds (ethanal, ethyl acetate, methanol, propanol-1, methyl-2-propanol-1, methyl-2-buthanol-1, and methyl-3-buthanol-1. Results showed that there was a significant linear and positive effect between gray bunch rot and the following variables: density, total and volatile acidity, dry extract, reduced dry extract, reducing sugars, ashes, alkalinity of ashes, color (I 420, total polyphenols (I 280, gluconic acid, P, K, Ca, Mn, Fe, Rb, ethanal, and ethyl acetate; there was a significant linear and negative effect on alcohol, alcohol in weight/reduced dry extract ratio, methyl-2-buthanol-1, and methyl-3-buthanol-1; a quadratic effect on total N, glycerol, and methanol; and a cubic effect on Mg, Zn, Li, and propanol-1. There was no significant effect on Na, Cu, and methyl-2-propanol-1.

  9. VALIDASI METODE ANALISIS MULTIRESIDU PESTISIDA ORGANOKLOR DALAM SALAK MENGGUNAKAN KROMATOGRAFI GAS-DETEKTOR PENANGKAP ELEKTRON

    Directory of Open Access Journals (Sweden)

    Tri Joko Raharjo

    2013-08-01

    Full Text Available Validation of methods is a key step in the accreditation process of the method. Validation of organoklor pesticide residues method in snakefruit based on the method recommended by FAO-WHO, conducted in LPPT-UGM reported in this study. Snake fruit was homogenized, extracted using toluene/2-propanol (2:1, cleaned up using activated carbon and Celite 545, followed by analysis using gas chromatography-electron capture detector. Validation covered specificity and selectivity, limits of detection and quantification, linear range, precision and accuracy. Validation results showed good specificity and selectivity shown by the inter-peak chromatogram resolution greater than 1.5. Limits of detection and quantification for heptaklor, endosulfan, dieldrin and p, p-DDT were 0.002 and 0.006, 0.5 and 1.7; 0.0006 and 0.002, as well as 0.014 and 0.047 ppm respectively. The linear range for heptaklor, endosulfan, dieldrin, and p,p-DDT were 0.0017 to 2 ppm, 0.165 to 2 ppm, 0.023 to 2 ppm and 0.229 to 2 ppm, respectively. Precision methods meet the acceptance of Horwitz RSD value less than 12.78% at a concentration of 0.3 ppm. Accuracy is indicated by recovery, for each pesticide in the range of 80-110% acceptance at a concentration of 0.1 ppm. Analysis of organochlorine pesticides in three commercial snakefruit samples showed no pesticide residues at concentrations higher than the detection limit. Keywords: Validation, organochlorine, snakefruit, gas chromatography electron capture   ASBTRAK Validasi metode merupakan tahap kunci dalam proses akreditasi suatu metode. Validasi metode uji residu pestisida organoklor dalam salak berdasarkan metode yang direkomendasikan FAO-WHO, di LPPT-UGM dilaporkan pada penelitian ini. Buah salak dihomogenisasi, diekstraksi menggunakan toluen/2-propanol (2:1, clean up menggunakan karbon aktif dan Celite 545, dilanjutkan analisis menggunakan kromatografi gas-detektor penangkap elektron. Validasi mencakup spesifisitas dan

  10. Automated extraction of 11-nor-delta9-tetrahydrocannabinol carboxylic acid from urine samples using the ASPEC XL solid-phase extraction system.

    Science.gov (United States)

    Langen, M C; de Bijl, G A; Egberts, A C

    2000-09-01

    The analysis of 11-nor-delta9-tetrahydrocannabinol-carboxylic acid (THCCOOH, the major metabolite of cannabis) in urine with gas chromatography and mass spectrometry (GC-MS) and solid-phase extraction (SPE) sample preparation is well documented. Automated SPE sample preparation of THCCOOH in urine, although potentially advantageous, is to our knowledge poorly investigated. The objective of the present study was to develop and validate an automated SPE sample-preparation step using ASPEC XL suited for GC-MS confirmation analysis of THCCOOH in urine drug control. The recoveries showed that it was not possible to transfer the protocol for the manual SPE procedure with the vacuum manifold to the ASPEC XL without loss of recovery. Making the sample more lipophilic by adding 1 mL 2-propanol after hydrolysis to the urine sample in order to overcome the problem of surface adsorption of THCCOOH led to an extraction efficiency (77%) comparable to that reached with the vacuum manifold (84%). The reproducibility of the automated SPE procedure was better (coefficient of variation 5%) than that of the manual procedure (coefficient of variation 12%). The limit of detection was 1 ng/mL, and the limit of quantitation was 4 ng/mL. Precision at the 12.5-ng/mL level was as follows: mean, 12.4 and coefficient of variation, 3.0%. Potential carryover was evaluated, but a carryover effect could not be detected. It was concluded that the proposed method is suited for GC-MS confirmation urinalysis of THCCOOH for prisons and detoxification centers.

  11. Structure and properties of polycaprolactone/chitosan nonwovens tailored by solvent systems.

    Science.gov (United States)

    Urbanek, Olga; Sajkiewicz, Paweł; Pierini, Filippo; Czerkies, Maciej; Kołbuk, Dorota

    2017-02-03

    Electrospinning of chitosan blends is a reasonable idea to prepare fibre mats for biomedical applications. Synthetic and natural components provide, for example, appropriate mechanical strength and biocompatibility, respectively. However, solvent characteristics and the polyelectrolyte nature of chitosan influence the spinnability of these blends. In order to compare the effect of solvent on polycaprolactone/chitosan fibres, two types of the most commonly used solvent systems were chosen, namely 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) and acetic acid (AA)/formic acid (FA). Results obtained by various experimental methods clearly indicated the effect of the solvent system on the structure and properties of electrospun polycaprolactone/chitosan fibres. Viscosity measurements confirmed different polymer-solvent interactions. Various molecular interactions resulting in different macromolecular conformations of chitosan influenced its spinnability and properties. HFIP enabled fibres to be obtained whose average diameter was less than 250 nm while maintaining the brittle and hydrophilic character of the nonwoven, typical for the chitosan component. Spectroscopy studies revealed the formation of chitosan salts in the case of the AA/FA solvent system. Chitosan salts visibly influenced the structure and properties of the prepared fibre mats. The use of AA/FA caused a reduction of Young's modulus and wettability of the proposed blends. It was confirmed that wettability, mechanical properties and the antibacterial effect of polycaprolactone/chitosan fibres may be tailored by selecting an appropriate solvent system. The MTT cell proliferation assay revealed an increase of cytotoxicity to mouse fibroblasts in the case of 25% w/w of chitosan in electrospun nonwovens.

  12. Effects of disinfectants and detergents on skin irritation.

    Science.gov (United States)

    Slotosch, Caroline M; Kampf, Günter; Löffler, Harald

    2007-10-01

    We investigated the biological response of regular human skin to alcohol-based disinfectants and detergents in a repetitive test design. Using non-invasive diagnostic tools such as transepidermal water loss, laser-Doppler flowmetry and corneometry, we quantified the irritative effects of a propanol-based hand disinfectant (Sterillium), its propanol mixture (2-propanol 45% w/w and 1-propanol 30% w/w), sodium lauryl sulfate (SLS) 0.5% and distilled water. The substances were applied in a 2-D patch test in a repetitive occlusive test design to the back. Additionally, we performed a wash test on the forearms that was supposed to mimic the skin affection in the normal daily routine of health care workers. In this controlled half-side test design, we included the single application of the hand rub, SLS 0.5% and water as well as a tandem application of the same substances. Patch test and wash test showed similar results. The alcohol-based test preparations showed minimal irritation rather comparable to the application of water. However, the detergent SLS produced stronger barrier disruption, erythema and dryness than the alcohol-based preparations. There was no additional irritation at the combined use of SLS and disinfectants. By contrary, there was even a decrease in barrier disruption and erythema induced by the tandem application of SLS followed by alcohol-based disinfection compared with the use of SLS alone. These findings show a less irritant effect of alcohol-based disinfectants on the skin than detergents. Our study shows that there is no summation of irritating effects of a common detergent and propanol and that the combination of washing and disinfection has a rather protective aspect compared with washing alone.

  13. Efficacy of ethanol-based hand foams using clinically relevant amounts: a cross-over controlled study among healthy volunteers

    Directory of Open Access Journals (Sweden)

    Marschall Sigunde

    2010-03-01

    Full Text Available Abstract Background Foams containing 62% ethanol are used for hand decontamination in many countries. A long drying time may reduce the compliance of healthcare workers in applying the recommended amount of foam. Therefore, we have investigated the correlation between the applied amount and drying time, and the bactericidal efficacy of ethanol foams. Methods In a first part of tests, four foams (Alcare plus, Avagard Foam, Bode test foam, Purell Instant Hand Sanitizer containing 62% ethanol, which is commonly used in U.S. hospitals, were applied to 14 volunteers in a total of seven variations, to measure drying times. In a second part of tests, the efficacy of the established amount of foam for a 30 s application time of two foams (Alcare plus, Purell Instant Hand Sanitizer and water was compared to the EN 1500 standard of 2 × 3 mL applications of 2-propanol 60% (v/v, on hands artificially contaminated with Escherichia coli. Each application used a cross-over design against the reference alcohol with 15 volunteers. Results The mean weight of the applied foam varied between 1.78 and 3.09 g, and the mean duration to dryness was between 37 s and 103 s. The correlation between the amount of foam applied and time until hands felt dry was highly significant (p 10-reduction: 3.05 ± 0.45 and Alcare plus (3.58 ± 0.71 was significantly less effective than the reference disinfection (4.83 ± 0.89 and 4.60 ± 0.59, respectively; p 10-reduction of 2.39 ± 0.57. Conclusions When using 62% ethanol foams, the time required for dryness often exceeds the recommended 30 s. Therefore, only a small volume is likely to be applied in clinical practice. Small amounts, however, failed to meet the efficacy requirements of EN 1500 and were only somewhat more effective than water.

  14. Sonochemical degradation of the pharmaceutical fluoxetine: Effect of parameters, organic and inorganic additives and combination with a biological system

    Energy Technology Data Exchange (ETDEWEB)

    Serna-Galvis, Efraím A.; Silva-Agredo, Javier [Grupo de Investigación en Remediación Ambiental y Biocatálisis, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Giraldo-Aguirre, Ana L. [Grupo de Diseño y Formulación de Medicamentos, Cosméticos y Afines (DYFOMECO), Facultad de Química Farmacéutica, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Torres-Palma, Ricardo A., E-mail: ricardo.torres@udea.edu.co [Grupo de Investigación en Remediación Ambiental y Biocatálisis, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia)

    2015-08-15

    Fluoxetine (FLX), one of the most widely used antidepressants in the world, is an emergent pollutant found in natural waters that causes disrupting effects on the endocrine systems of some aquatic species. This work explores the total elimination of FLX by sonochemical treatment coupled to a biological system. The biological process acting alone was shown to be unable to remove the pollutant, even under favourable conditions of pH and temperature. However, sonochemical treatment (600 kHz) was shown to be able to remove the pharmaceutical. Several parameters were evaluated for the ultrasound application: the applied power (20–60 W), dissolved gas (air, Ar and He), pH (3–11) and initial concentration of fluoxetine (2.9–162.0 μmol L{sup −1}). Additionally, the presence of organic (1-hexanol and 2-propanol) and inorganic (Fe{sup 2+}) compounds in the water matrix and the degradation of FLX in a natural mineral water were evaluated. The sonochemical treatment readily eliminates FLX following a kinetic Langmuir. After 360 min of ultrasonic irradiation, 15% mineralization was achieved. Analysis of the biodegradability provided evidence that the sonochemical process transforms the pollutant into biodegradable substances, which can then be mineralized in a subsequent biological treatment. - Highlights: • The pharmaceutical fluoxetine was effectively eliminated upon ultrasonic action. • Ultrasonic power, dissolved gas, pH and concentration of fluoxetine were evaluated. • Fe{sup 2+}, sodium nitrate or nitric acid had a positive effect on the FLX degradation. • More hydrophobic or volatile compounds than fluoxetine diminished the efficiency. • A sonochemical-biological combined process led to the total mineralization of FLX.

  15. Solvothermal syntheses of semiconductor photocatalysts of ultra-high activities

    Energy Technology Data Exchange (ETDEWEB)

    Kominami, Hiroshi; Kato, Jun-ichi; Murakami, Shin-ya; Ishii, Yoshinori; Kohno, Masaaki; Yabutani, Kei-ichi; Yamamoto, Takuhei; Kera, Yoshiya [Department of Applied Chemistry, Faculty of Science and Engineering, Kinki University, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Inoue, Masashi; Inui, Tomoyuki [Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Kyoto 606-8501 (Japan); Ohtani, Bunsho [Catalysis Research Center, Hokkaido University, Sapporo 060-0811 (Japan)

    2003-09-15

    Thermal treatment of titanium(IV) butoxide dissolved in 2-butanol at 573K under autogenous pressure (alcohothermal treatment) yielded microcrystalline anatase-type titanium(IV) oxide (TiO{sub 2}). Thermal treatment of oxobis(2,4-pentanedionato-O,O')titanium (TiO(acac){sub 2}) in ethylene glycol (EG) in the presence of sodium acetate and a small amount of water at 573K yielded microcrystalline brookite-type TiO{sub 2}. Tungsten(VI) oxide (WO{sub 3}) powders of monoclinic crystal structure with high crystallinity were synthesized by hydrothermal treatment (HTT), at 523 or 573K, of aqueous tungstic acid (H{sub 2}WO{sub 4}) solutions prepared from sodium tungstate by ion-exchange (IE) with a proton-type resin. Anatase and brookite TiO{sub 2} products were calcined at various temperatures and then used for photocatalytic mineralization of acetic acid in aqueous solutions under aerated conditions and dehydrogenation of 2-propanol under deaerated conditions. Almost all the anatase-type TiO{sub 2} samples showed the activities more than twice higher than those of representative active photocatalysts, Degussa P-25 and Ishihara ST-01 in both reactions. A brookite sample with improved crystallinity and sufficient surface area obtained by calcination at 973K exhibited the hydrogen evolution rate almost equal to P-25. HTT WO{sub 3} powders with various physical properties were used as photocatalyst for evolution of oxygen (O{sub 2}) from an aqueous silver sulfate solution. WO{sub 3} powder of high crystallinity, e.g., IE-HTT-WO{sub 3} synthesized at 573K, gave much higher O{sub 2} yield than commercially available WO{sub 3} samples.

  16. Final Report for CRADA Agreement , AL-C-2006-01 with Microsens Biotechnologies: Detection of the Abnormal Prion Protein in Blood by Improving the Extraction of this Protein

    Energy Technology Data Exchange (ETDEWEB)

    Schmerr, Mary Jo

    2009-03-31

    Several conditions were examined to optimize the extraction protocol using Seprion beads for the abnormal prion protein. Different combinations of water, hexafluro-2-propanol and formic acid were used. The results of these extraction protocols showed that the magnetic beads coated with Seprion reagents were subject to degradation, themselves, when the extraction conditions that would solubilize the abnormal prion protein were used. These compounds caused interference in the immunoassay for the abnormal prion protein and rendered these protocols incompatible with the assay systems. In an attempt to overcome this problem, another approach was then used. The coated beads were used as an integral part of the assay platform. After washing away denaturing agents, the beads with the 'captured' abnormal prion were incubated directly in the immunoassay, followed by analysis by the capillary electrophoresis. When a capillary electrophoresis electro-kinetic separation was attempted, the beads disturbed the analysis making it impossible to interpret. A pressure separation method was then developed for capillary electrophoresis analysis. When 20 samples, 5 of which were positive were analyzed, the assay identified 4 of the 5 positives and had no false positives. When a larger number of samples were analyzed the results were not as good - there were false positives and false negatives. It was then observed that the amount of beads that were loaded was dependent upon how long the beads were allowed to settle before loading them into the capillary. This resulted in unacceptable variations in the results and explained that when large numbers of samples were evaluated the results were not consistent. Because the technical difficulties with using the Seprion beads could not be overcome at this time, another approach is underway that is outside of the scope of this CRADA. No further agreements have been developed. Because the results were not favorable, no manuscripts were

  17. Role of 5-HT(1A) and 5-HT(1B) receptors in the antidepressant-like effect of piperine in the forced swim test.

    Science.gov (United States)

    Mao, Qing-Qiu; Huang, Zhen; Ip, Siu-Po; Xian, Yan-Fang; Che, Chun-Tao

    2011-10-24

    Our previous studies have showed that treating mice with piperine significantly decreased the immobility time of the animals in the forced swim test and tail suspension test, which was related to up-regulation of serotonin (5-HT) level in the brain. The purpose of this study is to explore the contribution of 5-HT receptors in the antidepressant-like effect of piperine. The results showed that pre-treating mice with methiothepin (a non-selective 5-HT receptor antagonist, 0.1mg/kg, intraperitoneally), 4-(2'-methoxy-phenyl)-1-[2'-(n-2″-pyridinyl)-p-iodobenzamino-]ethyl-piperazine (a selective 5-HT(1A) receptor antagonist, 1mg/kg, subcutaneously) or 1-(2-(1-pyrrolyl)-phenoxy)-3-isopropylamino-2-propanol (a 5-HT(1B) receptor antagonist, 2.5mg/kg, intraperitoneally) was found to abolish the anti-immobility effect of piperine (10mg/kg, intraperitoneally) in the forced swim test. On the other hand, a sub-effective dose of piperine (1mg/kg, intraperitoneally) produced a synergistic antidepressant-like effect with (+)-8-hydroxy-2-(di-n-propylamino)tetralin (a 5-HT(1A) receptor agonist, 1mg/kg, intraperitoneally) or anpirtoline (a 5-HT(1B) receptor agonist, 0.25mg/kg, intraperitoneally). Taken together, these results suggest that the antidepressant-like effect of piperine in the mouse forced swim test may be mediated, at least in part, by the activation of 5-HT(1A) and 5-HT(1B) receptors.

  18. Screening study of SFC critical method parameters for the determination of pharmaceutical compounds.

    Science.gov (United States)

    Dispas, Amandine; Lebrun, Pierre; Sacré, Pierre-Yves; Hubert, Philippe

    2016-06-05

    Nowadays, supercritical fluid chromatography is commonly presented as a promising alternative technique in the field of separation sciences. Nevertheless the selection of chromatographic conditions and sample preparation of pharmaceutical compounds remain a challenge and peak distortion was previously highlighted. The main objective of the present work was to evaluate the impact of different critical method parameters (CMPs), i.e. stationary phase, mobile phase composition and injection solvent nature. The experiments were performed considering two groups of antimalarial molecules: one group with neutral/apolar compounds and the other one with salt form of polar compounds. In this context, another objective was to propose a suitable sample solvent for quantitative analysis. The interest of new generation stationary phase to obtain good peak shape and the interest to tune the mobile phase composition were demonstrated. During this study, design of experiments and desirability function approach enabled to highlight optimal chromatographic conditions in order to maximise peak capacity and to get acceptable value of symmetry factor. Regarding sample injection solvent composition, some counterintuitive results were observed: solvents closer to the mobile phase polarity (i.e heptane or 2-propanol/heptane mixture) did not provide best results in terms of peak symmetry. In addition, acetonitrile and short aliphatic alcohols offered an interesting alternative as injection solvent: toxicity of solvents used is clearly reduced and better quantitative performances could be expected while keeping high peak capacity and symmetric sharp peaks. Finally, the quantitative performances were evaluated by the method validation for the quantitative determination of quinine sulfate in a pharmaceutical formulation. These better understandings on critical method parameters led SFC to be an even more promising technique in the field of the analysis of pharmaceutical compounds.

  19. Phase behavior and molecular dynamics simulation studies of new aqueous two-phase separation systems induced by HEPES buffer.

    Science.gov (United States)

    Taha, Mohamed; Khoiroh, Ianatul; Lee, Ming-Jer

    2013-01-17

    Here, for the first time, we show that with addition of a biological buffer, 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES), into aqueous solutions of tetrahydrofuran (THF), 1,3-dioxolane, 1,4-dioxane, 1-propanol, 2-propanol, tert-butanol, acetonitrile, or acetone, the organic solvent can be excluded from water to form a new liquid phase. The phase diagrams have been determined at ambient temperature. In order to understand why and how a zwitterion solute (HEPES) induced phase separation of the investigated systems, molecular dynamics (MD) simulation studies are performed for HEPES + water + THF system. The MD simulations were conducted for the aqueous mixtures with 12 different compositions. The reliability of the simulation results of HEPES in pure water and beyond the phase separation mixtures was justified by comparing the densities obtained from MD with the experimental values. The simulation results of HEPES in pure THF and in a composition inside the phase separation region were justified qualitatively. Interestingly, all HEPES molecules entirely aggregated in pure THF. This reveals that HEPES is insoluble in pure THF, which is consistent with the experimental results. Even more interestingly, the MD simulation for the mixture with composition inside the phase separation region showed the formation of two phases. The THF molecules are squeezed out from the water network into a new liquid phase. The hydrogen bonds (HBs), HB lifetime, HB Gibbs energy (ΔG), radial distribution functions (RDFs), coordination numbers (CNs), electrostatic interactions, and the van der Waals interactions between the different species have been analyzed. Further, MD simulations for the other phase separation systems by choosing a composition inside the two liquids region for each system were also simulated. Our findings will therefore pave the way for designing new benign separation auxiliary agents.

  20. Deuterium isotopic effects connected with unimolecular and concerted mechanisms. The case of 1-deutero-2-chloro alcohols; Effets isotopiques du deuterium attaches a des mecanismes unimoleculaires et concertes. Cas des deutero-1-chloro-2 alcools

    Energy Technology Data Exchange (ETDEWEB)

    Jambon, C

    1962-07-01

    After a bibliographic analysis of the probable causes of isotopic effects and their comparison, with the simplifications provided by the athermal model, a discussion of the isotopic effect of deuterium in organic molecules in terms of structural influences is presented, showing the important role of the C-D bond length which is shorter than the C-H bond length, and of the D atom's Van der Waals radius, shorter than that of the H atom. Kinetic measurements were carried out on some reactions involving the mechanisms proposed: unimolecular ionizations and halogen concentrates. The structural models chosen are: 2-chloro-cyclo-hexanols cis and trans 1-H and 2-D; 2-chloro-cyclo-pentanols cis trans 1-H and 1-D; 1-phenyl-l-chloro-2-propanol threo 2-H and 2-D. (author) [French] Apres une analyse bibliographique des causes probables d'effets isotopiques et leur comparaison, avec les simplifications qu'apporte le modele athermique, on a entrepris l'etude de la discussion isotopique du deuterium dans des molecules organiques en termes d'influences structurelles, cherchant a degager le role important de la longueur de la liaison C-D plus courte que C-H, et du rayon de Van der Waals de l'atome de D plus petit que celui de H. On a effectue des mesures cinetiques sur quelques reactions invoquant les mecanismes envisages: ionisations unimoleculaires et concentrees d'halogenes. Les modeles structuraux choisis sont: chloro 2 - cyclohexanols cis et trans H 1 et D 1; chloro 2 - cyclopentanols cis et trans H 1 et D 1; phenyl 1 - chloro 1 - propanol 2 threo H 2 et D 2. (auteur)

  1. Functional BK channels facilitate the β3-adrenoceptor agonist-mediated relaxation of nerve-evoked contractions in rat urinary bladder smooth muscle isolated strips.

    Science.gov (United States)

    Afeli, Serge A Y; Petkov, Georgi V

    2013-07-05

    The large-conductance voltage- and Ca(2+)-activated K(+) (BK) channel is a major regulator of detrusor smooth muscle (DSM) contractility thus facilitating urinary bladder function. Recent findings suggest that activation of β3-adrenoceptors causes DSM relaxation. However, it is unknown whether the β3-adrenoceptor-mediated DSM relaxation is BK channel-dependent during nerve-evoked contractions. To test this hypothesis, we induced nerve-evoked contractions in rat DSM isolated strips by using a tissue bath system equipped with platinum electrodes for electrical field stimulation (EFS). (±)-(R(*),R(*))-[4-[2-[[2-(3-chlorophenyl)-2-hydroxyethyl]amino]propyl]phenoxy] acetic acid sodium hydrate (BRL37344), a β3-adrenoceptor agonist, significantly decreased the amplitude and muscle force of the 20 Hz EFS-induced DSM contractions in a concentration-dependent manner. The BRL37344 inhibitory effect was significantly antagonized by 1-(2-ethylphenoxy)-3-[[(1S)-1,2,3,4-tetrahydro-1-naphthalenyl]amino]-(2S)-2-propanol hydrochloride (SR59230A), a β3-adrenoceptor antagonist. We further isolated the cholinergic from the purinergic component of the 0.5-50 Hz EFS-induced DSM contractions by using selective inhibitors, atropine as well as suramin and α,β-methylene-ATP. We found that BRL37344 inhibited both the purinergic and cholinergic components of the nerve-evoked contractions in rat DSM isolated strips. The pharmacological blockade of the BK channels with iberiotoxin, a selective BK channel inhibitor, increased the amplitude and muscle force of the 20 Hz EFS-induced contractions in rat DSM isolated strips. In the presence of iberiotoxin, there was a significant reduction in the BRL37344-induced inhibition of the 20 Hz EFS-induced contractions in rat DSM isolated strips. These latter findings suggest that BK channels play a critical role in the β3-adrenoceptor-mediated inhibition of rat DSM nerve-evoked contractions.

  2. An Integrated Theory of Adsorption and Partition Mechanism and Eash Contribution to Solute Retention in Reversed Phase Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    耿信笃; 弗莱德依瑞格涅尔

    2003-01-01

    With the combination of the the stoichiometric displacement model for retention (SDM-R) in reversed phase liquid chromatography (RPLC) and the stoichiometric displacement model for adsorption (SDM-A) in physical chemistry,the total number of moles of the re-solvated methanol of stationary phase side.nr,and that of solute side in the mobile phase,q,corresponding the one mole of the desorbing solute,were separately determined and referred as the characterization parameters of the contributions of the adsorption mechanism and partition mechanism to the solute retention,respectively.A chromatographic system of insulin,using mobile phase consisting of the pseudo-homologue of alcohols(methanol,ethanol and 2-propanol)-water and trifluoroacetic acid was employed.The maximum number of the methanol layers on the stationary phase surface was found to be 10.6,only 3 of which being valid in usual RPLC,traditionally referred as a volume process in partition mechanism.However,it still follows the SDM-R.Both of q and nr of insulin were found not to be zero,indicating that the retention mechanism of insulin is a mixed mode of partition mechanism and adsorption mechanism.When methanol is used as the organic modifier,the ratio of q/nr was 1.13,indicating the contribution to insulin retention due to partition mechanism being a bit greater than that due to adsorption mechanism.A linear relationship between q,or nr and the carbon number of the pseudo-homologue in the mobile phase was also found.As a methodology for investigating the retention mechanism retention and behavior of biopolymers.a homologue of organic solvents as the organic modifier in mobile phase has also been explored.

  3. Genotoxic damage induced by isopropanol in germinal and somatic cells of Drosophila melanogaster.

    Science.gov (United States)

    Palermo, Ana María; Mudry, Marta Dolores

    2011-12-24

    Isopropanol (isopropyl alcohol, 2-propanol, IPA) is a volatile solvent widely used in domestic or industrial environments and reported as innocuous in various test systems. The aim of this work was to search for in vivo genotoxic effects of IPA in Drosophila melanogaster, studying its ability to induce nondisjunction (ND) in females, sex linked recessive lethals (SLRL) in males, and somatic mutation and/or recombination (SMART) in larvae. Treatments were acute (60min) and were administered via inhalation. IPA had low toxicity in adult flies (75% IPA mortality index, MI=12.7% (females) and 2.6% (males)) and larvae (MI=14.3%, 75% IPA). Female fertility was severely affected during the first 24h (brood I, BI) after treatment, but, afterwards, control values were recovered. IPA induced a 50-fold increase of ND (%) in 24h old females, and a six-fold rise in 4-5 d old BI offspring. Nondisjunction frequencies (%) in the offspring of broods II to V (24h in each case) were similar to control values. IPA doses of 25% and 50% (v/v), tested in 24h old females, showed a significant dose-dependent increase of ND(%)in BI only, with control values in subsequent broods. Flies gave normal offspring when kept in regular media for 24h before mating. The eye spot test (SMART) showed a significant increase at 50% IPA (p<0.05, m=2), but the response was not dose-dependent. IPA failed to induce SLRL in any of the spermatogenesis stages tested. These findings suggest that the main effect of IPA is to induce chromosomal malsegregation; IPA must be present at the resumption of M-phase I after fertilization, to exert these effects. The alcohol does not affect DNA directly, but perturbations of the nuclear membrane may be responsible for induction of ND.

  4. Catalytic Hydrogenation of Acetone to Isopropanol: An Environmentally Benign Approach

    Directory of Open Access Journals (Sweden)

    Ateeq Rahman

    2011-01-01

    Full Text Available The catalytic hydrogenation of acetone is an important area of catalytic process to produce fine chemicals. Hydrogenation of acetone has important applications for heat pumps, fuel cells or in fulfilling the sizeable demand for the production of 2-propanol. Catalytic vapour phase hydrogenation of acetone has gained attention over the decades with variety of homogeneous catalysts notably Iridium, Rh, Ru complexes and heterogeneous catalysts comprising of Raney Nickel, Raney Sponge, Ni/Al2O3, Ni/SiO2, or Co-Al2O3, Pd, Rh, Ru, Re, or Fe/Al2O3 supported on SiO2 or MgO and even CoMgAl, NiMg Al layered double hydroxide, Cu metal, CuO, Cu2O. Nano catalysts are developed for actone reduction Ni maleate, cobalt oxide prepared in organic solvents. Author present a review on acetone hydrogenation under different conditions with various homogeneous and heterogeneous catalysts studied so far in literature and new strategies to develop economic and environmentally benign approach. ©2010 BCREC UNDIP. All rights reserved(Received: 16th June 2010, Revised: 18th October 2010; Accepted: 25th October 2010[How to Cite:Ateeq Rahman. (2010. Catalytic Hydrogenation of Acetone to Isopropanol: An Environmentally Benign Approach. Bulletin of Chemical Reaction Engineering and Catalysis, 5(2: 113-126. doi:10.9767/bcrec.5.2.798.113-126][DOI: http://dx.doi.org/10.9767/bcrec.5.2.798.113-126 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/798

  5. Mapping of the spectral density function of a C alpha-H alpha bond vector from NMR relaxation rates of a 13C-labelled alpha-carbon in motilin.

    Science.gov (United States)

    Allard, P; Jarvet, J; Ehrenberg, A; Gräslund, A

    1995-02-01

    The peptide hormone motilin was synthesised with a 13C-enriched alpha-carbon in the leucine at position 10. In aqueous solution, six different relaxation rates were measured for the 13C alpha-H alpha fragment as a function of temperature and with and without the addition of 30% (v/v) of the cosolvent d2-1,1,1,3,3,3-hexafluoro-2-propanol (HFP). The relaxation rates were analysed employing the spectral density mapping technique introduced by Peng and Wagner [(1992) J. Magn. Reson., 98, 308-332] and using the model-free approach by Lipari and Szabo [(1982) J. Am. Chem. Soc., 104, 4546-4570]. The fit to various models of dynamics was also considered. Different procedures to evaluate the overall rotational correlation time were compared. A single exponential time correlation function was found to give a good fit to the measured spectral densities only for motilin in 30% (v/v) HFP at low temperatures, whereas at high temperatures in this solvent, and in D2O at all temperatures, none of the considered models gave an acceptable fit. A new empirical spectral density function was tested and found to accurately fit the experimental spectral density mapping points. The application of spectral density mapping based on NMR relaxation data for a specific 13C-1H vector is shown to be a highly useful method to study biomolecular dynamics. Advantages are high sensitivity, high precision and uniform sampling of the spectral density function over the frequency range.

  6. Biocide and antibiotic resistance of Enterococcus faecalis and Enterococcus faecium isolated from the swine meat chain.

    Science.gov (United States)

    Rizzotti, Lucia; Rossi, Franca; Torriani, Sandra

    2016-12-01

    In this study nine strains of Enterococcus faecalis and 12 strains of Enterococcus faecium, isolated from different sample types in the swine meat chain and previously characterized for the presence of antibiotic resistance genes, were examined for phenotypic tolerance to seven biocides (chlorexidine, benzalkonium chloride, triclosan, sodium hypochlorite, 2-propanol, formaldehyde and hydrogen peroxide) and resistance to nine antibiotics (ampicillin, vancomycin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline and chloramphenicol). Moreover, the presence of efflux system encoding genes qacA/B, qacC, qacE, qacEΔ1, emeA, and stress response genes, sigV and gsp65, involved in the tolerance to biocides, was analysed. Most strains were not tolerant to the biocides, but showed minimum inhibitory concentrations (MICs) higher than the recommended cut-off values for all the antibiotics tested, except for vancomycin and chloramphenicol. Only weak correlations, if any, were found between biocide and antibiotic resistance data. One E. faecalis strain was tolerant to triclosan and one E. faecium strain, with higher tolerance to chlorexidine than the other strains tested, was found to carry a qacA/B gene. Our results indicated that phenotypic resistance to antibiotics is very frequent in enterococcal isolates from the swine meat chain, but phenotypic tolerance to biocides is not common. On the other hand, the gene qacA/B was found for the first time in the species E. faecium, an indication of the necessity to adopt measures suitable to control the spread of biocide resistance determinants among enterococci.

  7. Analysis of drugs of abuse in human plasma using microextraction by packed sorbents and ultra-high-performance liquid chromatography.

    Science.gov (United States)

    Fernández, P; González, M; Regenjo, M; Ares, A M; Fernández, A M; Lorenzo, R A; Carro, A M

    2017-02-17

    A miniaturized and simple method based on digitally programmed microextraction by packed sorbent (eVol(®)-MEPS) coupled to ultra-performance liquid chromatography (UPLC) has been developed for quantitative determination of three synthetic cathinones and seven conventional drugs of abuse and metabolites. The influence of several extraction parameters, such as washing and elution solvents were tested. In addition important variables affecting MEPS performance, namely sample volume, sorbent drying time, washing solvent volume, elution volume, number of extraction cycles, sorbent phase and pH, were evaluated using an asymmetrical screening design. The optimal experimental conditions involved 300μL of plasma, loading 10×100μL of sample through a C8/SCX sorbent in a MEPS syringe placed in the semi-automatic eVol(®) system, washing using 150μL H2O:MeOH (90:10, v/v), drying for 0.5min and elution using 200μL dichloromethane:2-propanol:ammonium hydroxide (78:20:2, v/v/v). The drugs separation was achieved using an ACQUITY BEH Shield RP18 column (2.1mm×100mm×1.7μm) in 3min. Under optimized conditions the proposed method was validated in terms of selectivity, linearity, limits of detection (LOD) and quantitation (LOQ), precision and matrix effect, using standard addition calibration. The combination of MEPS and UPLC provides a method for the primary screening of the analytes in 18min with excellent recoveries at three concentration levels, ranging between 80 and 104% (relative standard deviation <11%). The developed methodology has been successfully applied to plasma samples from polydrug abusers.

  8. Fast non-aqueous reversed-phase liquid chromatography separation of triacylglycerol regioisomers with isocratic mobile phase. Application to different oils and fats.

    Science.gov (United States)

    Tamba Sompila, Arnaud W G; Héron, Sylvie; Hmida, Dorra; Tchapla, Alain

    2017-01-15

    The distribution of fatty acid species at the sn-1/3 position or the sn-2 position of triacylglycerols (TAGs) in natural fats and oils affects their physical and nutritional properties. In fats and oils, determining the presence of one or two regioisomers and the identification of structure, where they do have one, as well as their separation, became a problem of fundamental importance to solve. A variety of instrumental technics has been proposed, such as MS, chromatography-MS or pure chromatography. A number of studies deal with the optimization of the separation, but very often, they are expensive in time. In the present study, in order to decrease the analysis time while maintaining good chromatographic separation, we tested different monomeric and polymeric stationary phases and different chromatographic conditions (mobile phase composition and analysis temperature) using Non-Aqueous Reversed Phase Liquid Chromatography (NARP-LC). It was demonstrated that mixed polymeric stationary bonded silica with accessible terminal hydroxyl groups leads to very good separation for the pairs of TAGs regioisomers constituted by two saturated and one unsaturated fatty acid (with double bond number: from 1 to 6). A Nucleodur C18 ISIS percolated by isocratic mobile phase (acetonitrile/2-propanol) at 18°C leads to their separations in less than 15min. The difference of retention times between two regioisomers XYX and XXY are large enough to confirm, as application, the presence of POP, SOP, SOS and PLP and no PPO, SPO, SSO and PPL in Theobroma cacao butter. In the same way, this study respectively shows the presence of SOS, SOP and no SSO, PSO in Butyrospermum parkii butter, POP, SOP, SOS and no PPO, PSO and SSO in Carapa oil and finally POP and no PPO in Pistacia Lentiscus oil.

  9. Synthesis and characterization of delta-atracotoxin-Ar1a, the lethal neurotoxin from venom of the Sydney funnel-web spider (Atrax robustus).

    Science.gov (United States)

    Alewood, Dianne; Birinyi-Strachan, Liesl C; Pallaghy, Paul K; Norton, Raymond S; Nicholson, Graham M; Alewood, Paul F

    2003-11-11

    Delta-atracotoxin-Ar1a (delta-ACTX-Ar1a) is the major polypeptide neurotoxin isolated from the venom of the male Sydney funnel-web spider, Atrax robustus. This neurotoxin targets both insect and mammalian voltage-gated sodium channels, where it competes with scorpion alpha-toxins for neurotoxin receptor site-3 to slow sodium-channel inactivation. Progress in characterizing the structure and mechanism of action of this toxin has been hampered by the limited supply of pure toxin from natural sources. In this paper, we describe the first successful chemical synthesis and oxidative refolding of the four-disulfide bond containing delta-ACTX-Ar1a. This synthesis involved solid-phase Boc chemistry using double coupling, followed by oxidative folding of purified peptide using a buffer of 2 M GdnHCl and glutathione/glutathiol in a 1:1 mixture of 2-propanol (pH 8.5). Successful oxidation and refolding was confirmed using both chemical and pharmacological characterization. Ion spray mass spectrometry was employed to confirm the molecular weight. (1)H NMR analysis showed identical chemical shifts for native and synthetic toxins, indicating that the synthetic toxin adopts the native fold. Pharmacological studies employing whole-cell patch clamp recordings from rat dorsal root ganglion neurons confirmed that synthetic delta-ACTX-Ar1a produced a slowing of the sodium current inactivation and hyperpolarizing shifts in the voltage-dependence of activation and inactivation similar to native toxin. Under current clamp conditions, we show for the first time that delta-ACTX-Ar1a produces spontaneous repetitive plateau potentials underlying the clinical symptoms seen during envenomation. This successful oxidative refolding of synthetic delta-ACTX-Ar1a paves the way for future structure-activity studies to determine the toxin pharmacophore.

  10. Highly efficient direct aerobic oxidative esterification of cinnamyl alcohol with alkyl alcohols catalysed by gold nanoparticles incarcerated in a nanoporous polymer matrix: a tool for investigating the role of the polymer host.

    Science.gov (United States)

    Buonerba, Antonio; Noschese, Annarita; Grassi, Alfonso

    2014-04-25

    The selective aerobic oxidation of cinnamyl alcohol to cinnamaldehyde, as well as direct oxidative esterification of this alcohol with primary and secondary aliphatic alcohols, were achieved with high chemoselectivity by using gold nanoparticles supported in a nanoporous semicrystalline multi-block copolymer matrix, which consisted of syndiotactic polystyrene-co-cis-1,4-polybutadiene. The cascade reaction that leads to the alkyl cinnamates occurs through two oxidation steps: the selective oxidation of cinnamyl alcohol to cinnamaldehyde, followed by oxidation of the hemiacetal that results from the base-catalysed reaction of cinnamaldehyde with an aliphatic alcohol. The rate constants for the two steps were evaluated in the temperature range 10-45 °C. The cinnamyl alcohol oxidation is faster than the oxidative esterification of cinnamaldehyde with methanol, ethanol, 2-propanol, 1-butanol, 1-hexanol or 1-octanol. The rate constants of the latter reaction are pseudo-zero order with respect to the aliphatic alcohol and decrease as the bulkiness of the alcohol is increased. The activation energy (Ea) for the two oxidation steps was calculated for esterification of cinnamyl alcohol with 1-butanol (Ea = 57.8±11.5 and 62.7±16.7 kJ mol(-1) for the first and second step, respectively). The oxidative esterification of cinnamyl alcohol with 2-phenylethanol follows pseudo-first-order kinetics with respect to 2-phenylethanol and is faster than observed for other alcohols because of fast diffusion of the aromatic alcohol in the crystalline phase of the support. The kinetic investigation allowed us to assess the role of the polymer support in the determination of both high activity and selectivity in the title reaction.

  11. Comparative study of photoinduced wettability conversion between [PW{sub 12}O{sub 40}]{sup 3−}/brookite and [SiW{sub 12}O{sub 40}]{sup 4−}/brookite hybrid films

    Energy Technology Data Exchange (ETDEWEB)

    Pruethiarenun, Kunchaya; Isobe, Toshihiro; Matsushita, Sachiko [Department of Metallurgy and Ceramic Science, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan); Ye, Jinhua [Environmental Remediation Materials Unit, Environment and Energy Materials Division, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Nakajima, Akira, E-mail: anakajim@ceram.titech.ac.jp [Department of Metallurgy and Ceramic Science, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2014-04-01

    Two tungsten-based Keggin-type heteropolyacids (PW{sub 12}: ([PW{sub 12}O{sub 40}]{sup 3−}) and SiW{sub 12}: ([SiW{sub 12}O{sub 40}]{sup 4−})) were hybridized with brookite-type TiO{sub 2}. Then photocatalytic decomposition activity, photoinduced hydrophilicity, and sustainability of the hydrophilicity in the dark were evaluated using gaseous 2-propanol (IPA) decomposition and sessile drop method. The obtained films were transparent in the visible wavelength range. Both hybrid films exhibited higher photocatalytic decomposition activity and had higher photoinduced hydrophilicizing rates than pure brookite films under UV illumination. The PW{sub 12}/TiO{sub 2} film exhibited better photocatalytic performance than the SiW{sub 12}/TiO{sub 2} film did. Atmosphere dependence, XPS analysis, and electrochemical experiments indicated the cause of these two films' different levels of sustainability of hydrophilicity to be differences in their electron storage capability. Results show that the electron scavenger capability and reoxidation efficiency of the heteropolyacid are key factors affecting the overall performance of wettability conversion of this hybrid film system before and after UV illumination. - Highlights: • Transparent PW{sub 12}/brookite(TTP) and SiW{sub 12}/brookite(TTS) films were prepared. • Both films exhibited better photocatalytic performance than pure brookite film. • The TTP film exhibited more sustainable hydrophilicity than the TTS film did. • Reoxidation efficiency of HPAs is a key factor for wettability conversion.

  12. Study of dilution of Spin-On Glass by Fourier transform infrared spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, Miguel, E-mail: mdominguez@inaoep.mx [National Institute for Astrophysics, Optics and Electronics (INAOE), Electronics Department, Luis Enrique Erro No. 1, Puebla 72840 (Mexico); Rosales, Pedro; Torres, Alfonso; Moreno, Mario [National Institute for Astrophysics, Optics and Electronics (INAOE), Electronics Department, Luis Enrique Erro No. 1, Puebla 72840 (Mexico); Orduna, Abdu [CIBA-Tlaxcala, Instituto Politecnico Nacional, Tepetitla, Tlax. 90700 (Mexico)

    2012-05-31

    In this work, we study the dilution of Spin-On Glass (SOG) in order to obtain high quality SiO{sub 2} films at 200 Degree-Sign C, with optical and electrical characteristics similar to those of the thermally grown SiO{sub 2}. For the production of SiO{sub 2} films we used 2-propanol and deionized water (DI) as diluents for the SOG and we compared the electrical and optical film properties with those of the films obtained from undiluted SOG. From Fourier transform infrared spectroscopy we observed a considerable reduction of Si-OH (920 cm{sup -1}), O-H (3490 cm{sup -1}) and C-H, C-O bonds (1139 cm{sup -1}) in the films produced from SOG diluted with DI. Besides the above, the insulator breakdown field was approximately 21 MV/cm, the refractive index and the dielectric constant were close to those of the thermally grown SiO{sub 2}. Our results suggest that the film produced from SOG diluted with DI and cured at 200 Degree-Sign C is an excellent candidate to be used as insulator on flexible and large-area electronics. - Highlights: Black-Right-Pointing-Pointer Preparation of high quality silicon oxide (SiO{sub 2}) films at 200 Degree-Sign C. Black-Right-Pointing-Pointer Dilution of Spin-On Glass (SOG) solution was studied. Black-Right-Pointing-Pointer Dilution of SOG is necessary to obtain high quality films annealed at 200 Degree-Sign C. Black-Right-Pointing-Pointer n and k are close to those of the thermally grown SiO{sub 2}.

  13. Histology without xylene.

    Science.gov (United States)

    Buesa, René J; Peshkov, Maxim V

    2009-08-01

    After the hazardous effects of xylene became indisputable in the 1970s, many potential substitutes became available, some with as many if not more hazards. This article discusses the inadequacy of 5 vegetable oils as substitutes, as well as the characteristics of 22 D-limonene-based substitutes, all less effective in their chemical role, some capable of inducing health problems, and costing more than twice as much as xylene. Some of the 35 alkane-based substitutes discussed are effective for tissue processing, less toxic, with a cost about the same as xylene, but are not very effective for dewaxing and other staining tasks. Isopropanol (2-propanol) alone or mixed with molten paraffin is a technically acceptable and cost-effective substitute for xylene for tissue processing, but in this study, we demonstrate that the best clearing agents from the sectioning quality and diagnostic value point of view, with automated or manual protocols, are mixtures of 5:1 and 2:1 isopropanol and mineral oil, followed by undiluted mineral oil, all at 50 degrees C, making them a safer and cheaper substitute than xylene. Using a 1.7% dishwasher soap aqueous solution at 90 degrees C to dewax before staining and oven drying the stained sections before coverslipping will eliminate xylene from the staining tasks. Tissue processors retorts and conduits can be dewaxed with a 2% solution of a strong glassware laboratory detergent. These 4 methodologies will make the histology laboratory xylene-free but, due to the natural resistance to change, many histotechs will be reluctant to adopt them if they think that their technical expertise could be jeopardized, and the only way these changes will succeed is if the pathologists, as stewards of the histology laboratory, commit to their implementation.

  14. Spontaneous Pattern Formation Induced by Bénard-Marangoni Convection for Sol-Gel-Derived Titania Dip-Coating Films: Effect of Co-solvents with a High Surface Tension and Low Volatility.

    Science.gov (United States)

    Uchiyama, Hiroaki; Matsui, Tadayuki; Kozuka, Hiromitsu

    2015-11-17

    Evaporation-driven surface tension gradient in the liquid layer often causes the convective flow, i.e., Bénard-Marangoni convection, resulting in the formation of cell-like patterns on the surface. Here, we prepared sol-gel-derived titania films from Ti(OC3H7(i))4 solutions by dip coating and discussed the effect of the addition of co-solvents with a high surface tension and low volatility on the spontaneous pattern formation induced by Bénard-Marangoni convection. Propylene glycol (PG, with a surface tension of 38.6 mN m(-1)) and dipropylene glycol (DPG, with a surface tension of 33.9 mN m(-1)) were added to the coating solutions containing 2-propanol (2-Pr, with a surface tension of 22.9 mN m(-1)) for controlling the evaporation-driven surface tension gradient in the coating layer on a substrate. During dip coating at a substrate withdrawal speed of 50 cm min(-1) in a thermostatic oven at 60 °C, linearly arranged cell-like patterns on a micrometer scale were spontaneously formed on the titania gel films, irrespective of the composition of coating solutions. Such surface patterns remained even after the heat treatment at 200 and 600 °C, where the densification and crystallization of the titania films progressed. The width and height of the cell-like patterns increased with increasing PG and DPG contents in the coating solutions, where the addition of PG resulted in the formation of cells with a larger height than DPG.

  15. Inorganic chemistry in a nanoreactor: Au/TiO2 nanocomposites by photolysis of a single-source precursor in miniemulsion.

    Science.gov (United States)

    Heutz, Niels A; Dolcet, Paolo; Birkner, Alexander; Casarin, Maurizio; Merz, Klaus; Gialanella, Stefano; Gross, Silvia

    2013-11-07

    An original synthetic route, based on the combination of a single-source precursor, UV-photodegradation and inverse w/o miniemulsion, is used to prepare Au nanoparticles (NPs) dispersed on titania. The source of the nanocomposite materials is the photolabile single-source precursor AuCl4(NH4)7[Ti2(O2)2(cit)(Hcit)]2·12H2O, which is suspended in a w/o miniemulsion consisting of different surfactant/hydrocarbon/water formulations (surfactant: sodium dodecylsulfate (SDS) or Triton X-100) and subsequently irradiated with a UV lamp to promote its decomposition in the confined space of the droplets. Gold NPs that form at room temperature are found to be crystalline, while titanium dioxide occurs as an amorphous phase. Moreover, the average crystallite size of gold NPs ranges between 20 and 24 nm when using SDS and between 26 and 40 nm in the case of Triton X-100, after 4 and 8 hours of irradiation time, respectively. Scanning and transmission electron microscopies (SEM and TEM) are used to get information about the nanocomposite morphology and nanostructure, revealing that gold NPs are uniformly distributed on the titanium oxide surface. Furthermore, X-ray photoelectron spectroscopy (XPS) outcomes, besides confirming the formation of both metallic gold and titania, provide information about the high dispersion of Au NPs on the TiO2 surface. In fact, the Au : Ti atomic ratio is found to be 0.45-1.5 (1 : 2-1.5 : 1), which is higher than the value determined by starting from the precursor stoichiometry (0.25). Catalytic testing in the oxidation of 2-propanol shows that decomposition of the precursor in a miniemulsion provides a nanocomposite with enhanced activity compared to the decomposition in the aqueous phase.

  16. Dual-function 2-nitroimidazoles as hypoxic cell radiosensitizers and bioreductive cytotoxins: In vivo evaluation in KHT murine sarcomas

    Energy Technology Data Exchange (ETDEWEB)

    Cole, S.; Stratford, I.J.; Adams, G.E.; Fielden, E.M.; Jenkins, T.C. (Medical Research Council, Didcot, Oxon (England))

    1990-10-01

    The efficacies of a series of potential prodrugs of RSU-1069 and its alkyl-aziridine analogues were assessed. These 1-(2-haloethylamino)-3-(2-nitro-1-imidazolyl)-2-propanol compounds were designed to cyclize in vivo to generate 2-nitro-imidazoles with aziridine (RSU-1069) or alkyl-substituted aziridine (RSU-1164, RB-7040, or RSU-1150) functions. Maximum tolerated single, intraperitoneal doses (MTD) were determined in C3H/He mice bearing subcutaneous KHT sarcomas, and a drug dose-response relationship for radiosensitization was established for each compound administered at the optimum time (45-60 min) before local irradiation of tumors with a 10-Gy dose of X-rays. The potentials of the compounds as bioreductive cytotoxins were studied by administering them immediately after irradiation. Tumor cell survival was measured 18-24 h after treatment in an in vitro soft agar clonogenic assay. Results of toxicity, radiosensitization, and bioreductive cytotoxicity assays for each of the prodrugs (RB-6171, RB-6172, RB-6173, RB-6174, and RB-6175) of the alkyl-substituted aziridines were entirely consistent with complete conversion to their respective target compounds. For example, RB-6171 (the prodrug form of RSU-1164) was only about four times less efficient than RSU-1069 as a radiosensitizer and bioreductive cytotoxin but had an MTD 7.5 times higher. In contrast, prodrugs of RSU-1069 (RB-6144 and RB-6145) were two- to threefold less toxic than their expected product. RB-6144 was a poor radiosensitizer and bioreductive agent compared with RSU-1069 and was similar to RB-6170, a nonalkylating nitroimidazole. This is consistent with the observation that there is limited conversion of RB-6144 to RSU-1069 in vitro. However, radiosensitization and bioreductive cytotoxicity produced by RB-6145 were only slightly less than the effects produced by RSU-1069.

  17. Analysis of 3-MCPD and 1,3-DCP in Various Foodstuffs Using GC-MS.

    Science.gov (United States)

    Kim, Wooseok; Jeong, Yun A; On, Jiwon; Choi, Ari; Lee, Jee-Yeon; Lee, Joon Goo; Lee, Kwang-Geun; Pyo, Heesoo

    2015-09-01

    3-Monochloro-1,2-propanediol (3-MCPD) and 1,3-dichloro-2-propanol (1,3-DCP) are not only produced in the manufacturing process of foodstuffs such as hydrolyzed vegetable proteins and soy sauce but are also formed by heat processing in the presence of fat and low water activity. 3-MCPD exists both in free and ester forms, and the ester form has been also detected in various foods. Free 3-MCPD and 1,3-DCP are classified as Group 2B by the International Agency for Research on Cancer. Although there is no data confirming the toxicity of either compound in humans, their toxicity was evidenced in animal experimentation or in vitro. Although few studies have been conducted, free 3-MCPD has been shown to have neurotoxicity, reproductive toxicity, and carcinogenicity. In contrast, 1,3-DCP only has mutagenic activity. The purpose of this study was to analyze 3-MCPD and 1,3-DCP in various foods using gas chromatography -mass spectrometry. 3-MCPD and 1,3-DCP were analyzed using phenyl boronic acid derivatization and the liquid-liquid extraction method, respectively. The analytical method for 3-MCPD and 1,3-DCP was validated in terms of linearity, limit of detection (LOD), limit of quantitation, accuracy and precision. Consequently, the LODs of 3-MCPD and 1,3-DCP in various matrices were identified to be in the ranges of 4.18~10.56 ng/g and 1.06~3.15 ng/g, respectively.

  18. Pharmacokinetics of mitomycin C in dogs: application of a high-performance liquid chromatographic assay.

    Science.gov (United States)

    Barbhaiya, R H; Papp, E A; Van Harken, D R; Smyth, R D

    1984-09-01

    A normal-phase high-performance liquid chromatographic (HPLC) assay was developed for the determination of mitomycin C in plasma and urine. The method involves extraction of mitomycin C from plasma or urine into ethyl acetate-2-propanol-chloroform (70:15:15) with UV detection at 365 nm. Quantitation was performed with an internal standard (porfiromycin) by the peak height ratio method. Excellent correlation was obtained between the HPLC assay and the established microbiological cup-plate bioassay. The pharmacokinetics of mitomycin C were investigated in beagle dogs following a 1-mg/kg iv (22-mg/m2) bolus dose. The plasma mitomycin C concentration versus time data were analyzed by using an open three-compartment model. The average volume of distribution was 1.90 L or 17% of body weight for the central compartment and 7.7 L or 68% of body weight for the terminal elimination phase. The volumes of distribution at steady state, calculated by model-dependent and -independent methods, compared very well with each other and were 6.5 L or 58% of body weight. Total body clearance averaged 112 mL/min, and the mean terminal plasma half-life was 53 min. The 0-24-h urinary excretion of intact mitomycin C accounted for 19% of the dose. The terminal half-life and percent urinary recovery of mitomycin C in dogs is similar to that in humans. Based on these observations, the dog appears to be a good model for studying the disposition of mitomycin C.

  19. Relation between phase composition and photocatalytic activity of TiO{sub 2} in a sulfoxide deoxygenation reaction

    Energy Technology Data Exchange (ETDEWEB)

    Molinari, Alessandra, E-mail: alessandra.molinari@unife.it [Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17, 44121 Ferrara (Italy); Bonino, Francesca; Magnacca, Giuliana [Dipartimento di Chimica, NIS and INSTM Reference Centre, Università di Torino, Via G. Quarello 15, I-10135 and Via P. Giuria 7, I-10125, Turin (Italy); Demaria, Francesca; Maldotti, Andrea [Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17, 44121 Ferrara (Italy)

    2015-05-05

    In the present study we synthesize three TiO{sub 2} samples, TiO{sub 2}-500, TiO{sub 2}-750 and TiO{sub 2}-850, by a sol–gel procedure varying the rutile and anatase content by calcination at different temperatures. Characterization by XRD, NIR-Raman, UV-Raman, BET, DR-UV-Vis spectroscopy and SEM points out that TiO{sub 2}-500 consists mainly of anatase and TiO{sub 2}-850 of rutile. TiO{sub 2}-700 presents both phases on the surface that is the part of the photocatalyst interested by UV illumination. The photocatalysts are tested in the deoxygenation reaction of methyl p-tolyl sulfoxide to the corresponding sulfide using 2-propanol as hole scavenger. It is demonstrated that the presence of both anatase and rutile on the surface of TiO{sub 2}-700 is responsible of the increase of the photocatalytic activity. This is likely due to a more efficient charge separation process that increases lifetime of the charges giving availability of electrons and holes for the photocatalytic reaction. Methyl p-tolyl sulfide is formed with a selectivity of 100%. - Highlights: • TiO{sub 2} samples are synthesized via sol–gel varying the rutile and anatase composition. • TiO{sub 2}-700 (calcined at 700 °C) presents both anatase and rutile on the surface. • Efficient charges separation is allowed by the presence of anatase and rutile. • Spatial separation of charges renders TiO{sub 2}-700 the most active photocatalyst. • Methyl p-tolyl sulfoxide is transformed in sulfide with 100% selectivity.

  20. Bio-based degradation of emerging endocrine-disrupting and dye-based pollutants using cross-linked enzyme aggregates.

    Science.gov (United States)

    Bilal, Muhammad; Asgher, Muhammad; Iqbal, Hafiz M N; Hu, Hongbo; Zhang, Xuehong

    2017-01-14

    In this study, manganese peroxidase (MnP) from an indigenous white-rot fungus Ganoderma lucidum IBL-05 was insolubilized in the form of cross-linked enzyme aggregates (CLEAs) using various aggregating agents, i.e., acetone, ammonium sulfate, ethanol, 2-propanol, and tert-butanol, followed by glutaraldehyde (GA) cross-linking. The precipitant type, MnP, and GA concentrations affected the CLEAs activity recovery and aggregation yield. Among precipitants used, acetone appeared to be the most efficient aggregation agent, providing the highest activity recovery and aggregation yield of 31.26 and 73.46%, respectively. Optimal cross-linking was noticed using 2.0% (v/v) GA and 8:1 (v/v) MnP to GA ratio at 3.0 h cross-linking time under continuous agitation at 4 °C. The highest recovered activity and aggregation yield were determined to be 47.57 and 81.26%, respectively. The MnP-CLEAs, thus synthesized, were tested to investigate their bio-catalytic capacity for removing two known endocrine-disrupting chemicals (EDCs), e.g., nonylphenol and triclosan in a packed bed reactor system. The insolubilized MnP efficiently catalyzed the biodegradation of both EDCs, transforming over 80% in the presence of MnP-based system. A maximal of 100% decolorization was recorded for Sitara textile (SIT-based) effluent, followed by 95.5% for Crescent textile (CRT-based) effluent, 88.0% for K&N textile (KIT-based) effluent, and 84.2% for Nishat textile (NIT-based) effluent.

  1. Permeation of 70% isopropyl alcohol through surgical gloves: comparison of the standard methods ASTM F739 and EN 374.

    Science.gov (United States)

    Mäkelä, Erja A; Vainiotalo, Sinikka; Peltonen, Kimmo

    2003-06-01

    Standard test methods ASTM F739 and EN 374 were compared by assessing the permeation of 70% isopropyl alcohol (2-propanol) through seven brands of surgical gloves. The two standards differ in the flow rates of the collection medium and in the chemical permeation rate at which the breakthrough time (BTT) is detected, the EN detection level being 10 times higher than the permeation rate used by ASTM. In a departure from the EN standard method, a 4 h testing time was used instead of 8 h. All of the tested gloves were from the same manufacturer and were made from either natural rubber (NR) (six brands) or chloroprene rubber (CR) (one brand). Two of the NR glove brands were double layered. For the thin NR gloves (0.22, 0.28 and 0.27 mm) the permeation rates were higher throughout the tests with a flow rate of 474 ml/min (EN) of the collection medium (nitrogen) compared with the permeation rates obtained with a flow rate of 52 ml/min (ASTM). These resulted in BTTs of 4.6, 6.5 and 7.6 min (EN) and 4.8, 6.5 and 9.1 min (ASTM), respectively. No statistical difference could be observed between the BTT values obtained with the two standard methods for any of the thin gloves. Thus, although the ASTM standard has a lower criterion for the detection of permeation, it does not necessarily produce shorter BTTs. For the better barriers the methods yielded more equivalent permeation rate curves and thus the EN BTTs were longer than the ASTM BTTs: the EN results were 21, 80, 122 and >240 min compared with the ASTM results of 12, 32, 38 and 103 min for glove thicknesses of 0.37 (NR), 0.22 + 0.22 (double layered NR), 0.31 + 0.29 (double layered NR) and 0.19 mm (CR), respectively.

  2. Crystal structures of halohydrin hydrogen-halide-lyases from Corynebacterium sp. N-1074.

    Science.gov (United States)

    Watanabe, Fumiaki; Yu, Fujio; Ohtaki, Akashi; Yamanaka, Yasuaki; Noguchi, Keiichi; Yohda, Masafumi; Odaka, Masafumi

    2015-12-01

    Halohydrin hydrogen-halide-lyase (H-Lyase) is a bacterial enzyme that is involved in the degradation of halohydrins. This enzyme catalyzes the intramolecular nucleophilic displacement of a halogen by a vicinal hydroxyl group in halohydrins to produce the corresponding epoxides. The epoxide products are subsequently hydrolyzed by an epoxide hydrolase, yielding the corresponding 1, 2-diol. Until now, six different H-Lyases have been studied. These H-Lyases are grouped into three subtypes (A, B, and C) based on amino acid sequence similarities and exhibit different enantioselectivity. Corynebacterium sp. strain N-1074 has two different isozymes of H-Lyase, HheA (A-type) and HheB (B-type). We have determined their crystal structures to elucidate the differences in enantioselectivity among them. All three groups share a similar structure, including catalytic sites. The lack of enantioselectivity of HheA seems to be due to the relatively wide size of the substrate tunnel compared to that of other H-Lyases. Among the B-type H-Lyases, HheB shows relatively high enantioselectivity compared to that of HheBGP1 . This difference seems to be due to amino acid replacements at the active site tunnel. The binding mode of 1, 3-dicyano-2-propanol at the catalytic site in the crystal structure of the HheB-DiCN complex suggests that the product should be (R)-epichlorohydrin, which agrees with the enantioselectivity of HheB. Comparison with the structure of HheC provides a clue for the difference in their enantioselectivity.

  3. Optimization of a New Aerodynamic Cylindrical FAIMS Device for Small Molecule Analysis

    Science.gov (United States)

    Purves, Randy W.; Prasad, Satendra; Belford, Michael; Vandenberg, Albert; Dunyach, Jean-Jacques

    2017-03-01

    The implementation of an aerodynamic mechanism to improve ion sampling between nanoelectrospray (n-ESI) and FAIMS was recently reported for proteomic analyses. This investigation explores the new FAIMS interface for small molecule analysis at high liquid flow rates and includes an examination of key differences in ionization between heated-ESI (HESI) and n-ESI. The sheath gas, critical for desolvation with HESI, affects FAIMS operation as higher FAIMS gas flow rates are required to achieve sufficient desolvation. Gas flow rate experiments also uncovered m/z discrimination with the conventional design as larger (slower moving) m/z ions experienced larger signal intensity losses than smaller m/z ions due to the desolvation gas flow having a greater drag effect on slower moving ions. The modified inlet in new FAIMS dampens the gas drag, making the HESI source more amenable as less m/z bias and significantly lower %RSD values were observed. Furthermore, a larger radius inner electrode in new FAIMS enables significantly higher E/N (electric field/number gas density) to be achieved using the existing waveform generator. Thus, new FAIMS signal intensities using only nitrogen improved 1.25- to 2-fold compared with the conventional design and 50% helium. Adding helium to the new FAIMS gave no significant improvements. The larger inner electrode also decreased ion focusing capabilities, and the effect on peak separation and ion intensity was examined in detail. The peak capacity of new FAIMS was approximately double that of conventional FAIMS; separation of seven low m/z ions gave a peak capacity of 37.7 using the gas additive 2-propanol.

  4. Caustic-Side Solvent Extraction: Chemical and Physical Properties of the Optimized Solvent

    Energy Technology Data Exchange (ETDEWEB)

    Delmau, L.H.

    2002-10-08

    This work was undertaken to optimize the solvent used in the Caustic Side Solvent Extraction (CSSX) process and to measure key chemical and physical properties related to its performance in the removal of cesium from the alkaline high-level salt waste stored in tanks at the Savannah River Site. The need to adjust the solvent composition arose from the prior discovery that the previous baseline solvent was supersaturated with respect to the calixarene extractant. The following solvent-component concentrations in Isopar{reg_sign} L diluent are recommended: 0.007 M calix[4]arene-bis(tert-octylbenzo-crown-6) (BOBCalixC6) extractant, 0.75 M 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB) phase modifier, and 0.003 M tri-n-octylamine (TOA) stripping aid. Criteria for this selection included BOBCalixC6 solubility, batch cesium distribution ratios (D{sub Cs}), calculated flowsheet robustness, third-phase formation, coalescence rate (dispersion numbers), and solvent density. Although minor compromises within acceptable limits were made in flowsheet robustness and solvent density, significant benefits were gained in lower risk of third-phase formation and lower solvent cost. Data are also reported for the optimized solvent regarding the temperature dependence of D{sub Cs} in extraction, scrubbing, and stripping (ESS); ESS performance on recycle; partitioning of BOBCalixC6, Cs-7SB, and TOA to aqueous process solutions; partitioning of organic anions; distribution of metals; solvent phase separation at low temperatures; solvent stability to elevated temperatures; and solvent density and viscosity. Overall, the technical risk of the CSSX process has been reduced by resolving previously identified issues and raising no new issues.

  5. Monte Carlo Simulation of Aqueous Dilute Solutions of Polyhydric Alcohols

    Science.gov (United States)

    Lilly, Arnys Clifton, Jr.

    In order to investigate the details of hydrogen bonding and solution molecular conformation of complex alcohols in water, isobaric-isothermal Monte Carlo simulations were carried out on several systems. The solutes investigated were ethanol, ethylene glycol, 1,2-propylene glycol, 1,3 -propylene glycol and glycerol. In addition, propane, which does not hydrogen bond but does form water hydrates, was simulated in aqueous solution. The complex alcohol-water systems are very nonideal in their behavior as a function of solute concentration down to very dilute solutions. The water model employed was TIP4P water^1 and the intermolecular potentials employed are of the Jorgensen type^2 in which the interactions between the molecules are represented by interaction sites usually located on nuclei. The interactions are represented by a sum of Coulomb and Lennard-Jones terms between all intermolecular pairs of sites. Intramolecular rotations in the solute are modeled by torsional potential energy functions taken from ethanol, 1-propanol and 2-propanol for C-O and C-C bond rotations. Quasi-component pair correlation functions were used to analyze the hydrogen bonding. Hydrogen bonds were classified as proton acceptor and proton donor bonds by analyzing the nearest neighbor pair correlation function between hydroxyl oxygen and hydrogen and between solvent-water hydrogen and oxygen. The results obtained for partial molar heats of solution are more negative than experimental values by 3.0 to 14 kcal/mol. In solution, all solutes reached a contracted molecular geometry with the OH groups generally on one side of the molecule. There is a tendency for the solute OH groups to hydrogen bond with water, with more proton acceptor bonds than proton donor bonds. The water -solute binding energies correlate with experimental measurements of the water-binding properties of the solute. ftn ^1Jorgensen, W. L. et al, J. Chem. Phys., 79, 926 (1983). ^2Jorgensen, W. L., J. Phys Chem., 87, 5304

  6. Qualitative and quantitative analysis of a group of volatile organic compounds in biological samples by HS-GC/FID: application in practical cases.

    Science.gov (United States)

    Monteiro, C; Franco, J M; Proença, P; Castañera, A; Claro, A; Vieira, D N; Corte-Real, F

    2014-10-01

    A simple and sensitive procedure, using n-propanol as internal standard (IS), was developed and validated for the qualitative and quantitative analysis of a group of 11 volatile organic substances with different physicochemical properties (1-butanol, 2-propanol, acetaldehyde, ethyl acetate, acetone, acetonitrile, chloroform, diethyl ether, methanol, toluene and p-xylene) in whole blood, urine and vitreous humor. Samples were prepared by dilution with an aqueous solution of internal standard followed by Headspace Gas Chromatography with a Flame-ionization Detector (HS GC-FID) analysis. Chromatographic separation was performed using two capillary columns with different polarities (DB-ALC2: 30m×0.320mm×1.2μm and DB-ALC1: 30m×0.320mm×1.8μm), thus providing a change in the retention and elution order of volatiles. This dual column confirmation increases the specificity, since the risk of another substance co-eluting at the same time in both columns is very small. The method was linear from 5 to 1000mg/L for toluene and p-xylene, 50-1000mg/L for chloroform, and 50-2000mg/L for the remaining substances, with correlation coefficients of over 0.99 for all compounds. The limits of detection (LOD) ranged 1 to 10mg/L, while the limits of quantification (LOQ) ranged from 2 to 31mg/L. The intra-day precision (CV<6.4%), intermediate precision (CV<7.0%) and accuracy (relative error ±10%) of the method were in conformity with the criteria normally accepted in bioanalytical method validation. The method developed has been applied to forensic cases, with the advantages that it uses a small sample volume and does not require any extraction procedure as it makes use of a headspace injection technique.

  7. Determination of thermodynamic properties of poly(cyclohexyl methacrylate)by inverse gas chromatography

    Institute of Scientific and Technical Information of China (English)

    Ismet KAYA; Cigdem Yigit PALA

    2014-01-01

    In this work,some thermodynamic properties of poly( cyclohexyl methacrylate)were studied by inverse gas chromatography( IGC). For this purpose,the polymeric substance was coated on Chromosorb W and which was filled into a glass column. The retention times(tr)of the probes were determined from the interactions of poly(cyclohexyl methacrylate)with n-pentane,n-hexane,n-heptane,n-octane,n-decane, methanol,ethanol,2-propanol,butanol,acetone,ethyl methyl ketone,benzene,toluene and o-xylene by IGC technique. Then,the specific volume(V0g)was determined for each probe molecule. By using(1/T;lnV0g) graphics,the glass transition temperature of poly( cyclohexyl methacrylate)was found to be 373 K. The adsorp-tion heat under the glass transition temperature(ΔH a ),and partial molar heat of sorption above the glass tran-sition(ΔHS1 ),partial molar free energy of sorption(ΔGS1 )and partial molar entropy of sorption(ΔSS1 )belong-ing to sorption for every probe were calculated. The partial molar heat of mixing at infinite dilution(ΔH∞1 ), partial molar free energy of mixing at infinite dilution(ΔG∞1 ),Flory-Huggins interaction parameter(χ∞12 )and weight fraction activity coefficient(a1/w1)∞ values of polymer-solute systems were calculated at different col-umn temperatures. The solubility parameters(δ2 )of the polymer were obtained by IGC technique.

  8. Quantification of free formaldehyde in carrageenan and processed Eucheuma seaweed using high-performance liquid chromatography.

    Science.gov (United States)

    Hornshøj, Bettina Høj; Kobbelgaard, Sara; Blakemore, William R; Stapelfeldt, Henrik; Bixler, Harris J; Klinger, Markus

    2015-01-01

    In 2010 the European Commission placed a limit on the amount of free formaldehyde in carrageenan and processed Eucheuma seaweed (PES) of 5 mg kg(-1). Formaldehyde is not used in carrageenan and PES processing and accordingly one would not expect free formaldehyde to be present in carrageenan and PES. However, surprisingly high levels up to 10 mg kg(-1) have been found using the generally accepted AOAC and Hach tests. These findings are, per proposed reaction pathways, likely due to the formation of formaldehyde when sulphated galactose, the backbone of carrageenan, is hydrolysed with the strong acid used in these conventional tests. In order to minimise the risk of false-positives, which may lead to regulatory non-compliance, a new high-performance liquid chromatography (HPLC) method has been developed. Initially, carrageenan or PES is extracted with 2-propanol and subsequently reacted with 2,4-dinitrophenylhydrazine (DNPH) to form the chromophore formaldehyde-DNPH, which is finally quantified by reversed-phase HPLC with ultraviolet light detection at 355 nm. This method has been found to have a limit of detection of 0.05 mg kg(-1) and a limit of quantification of 0.2 mg kg(-1). Recoveries from samples spiked with known quantities of formaldehyde were 95-107%. Using this more specific technique, 20 samples of carrageenan and PES were tested for formaldehyde. Only one sample had a detectable content of formaldehyde (0.40 mg kg(-1)), thus demonstrating that the formaldehyde content of commercial carrageenan and PES products are well below the European Commission maximum limit of 5 mg kg(-1).

  9. Evaluation of salicylic acid fatty ester prodrugs for UV protection.

    Science.gov (United States)

    Im, Jong Seob; Balakrishnan, Prabagar; Oh, Dong Hoon; Kim, Jung Sun; Jeon, Eun-Mi; Kim, Dae-Duk; Yong, Chul Soon; Choi, Han-Gon

    2011-07-01

    The purpose of this study was to investigate the physicochemical properties and in vitro evaluation of fatty ester prodrugs of salicylic acid for ultraviolet (UV) protection. The physicochemical properties such as lipophilicity, chemical stability and enzymatic hydrolysis were investigated with the following fatty ester prodrugs of salicylic acid: octanoyl (C8SA), nonanoyl (C9SA), decanoyl (C10SA), lauroyl (C12SA), myristoyl (C14SA) and palmitoyl oxysalicylate (C16SA). Furthermore, their skin permeation and accumulation were evaluated using a combination of common permeation enhancing techniques such as the use of a lipophilic receptor solution, removal of stratum corneum and delipidization of skin. Their k' values were proportional to the degree of carbon-carbon saturation in the side chain. All these fatty esters were highly stable in 2-propanol, acetonitrile and glycerin, but unstable in methanol and ethanol. They were relatively unstable in liver and skin homogenates. In particular, C16SA was mostly hydrolyzed to its parent compound in hairless mouse liver and skin homogenates, suggesting that it might be converted to salicylic acid after its topical administration. In the skin permeation and accumulation study, C16SA showed the poorest permeation in all skins, suggesting that it could not be permeated in the skin. Furthermore, C14SA and C16SA were less accumulated in delipidized skin compared with normal skin or stripped skin, suggesting that these esters had relatively strong affinities for lipids compared with the other prodrugs in the skin. C16SA showed significantly higher dermal accumulation in all skins compared with its parent salicylic acid. Thus, the palmitoyl oxysalicylate (C16SA) might be a potential candidate for UV protection due to its absence of skin permeation, smaller uptake in the lipid phase and relatively lower skin accumulation.

  10. Enzymatic polymerization of natural anacardic acid and antibiofouling effects of polyanacardic acid coatings.

    Science.gov (United States)

    Chelikani, Rahul; Kim, Yong Hwan; Yoon, Do-Young; Kim, Dong-Shik

    2009-05-01

    Anacardic acid, separated from cashew nut shell liquid, is well known for its strong antibiotic and antioxidant activities. Recent findings indicate that phenolic compounds from plant sources have an effect on Gram-negative bacteria biofilm formation. In this work, a polyphenolic coating was prepared from anacardic acid using enzymatic synthesis and tested for its effects on biofilm formation of both Gram-negative and Gram-positive bacteria. Natural anacardic acid was enzymatically polymerized using soybean peroxidase. Hydrogen peroxide and phenothiazine-10-propionic acid were used as an oxidizing agent and redox mediator, respectively. Nuclear magnetic resonance and Fourier transform infrared (FTIR) analyses showed the formation of oxyphenylene and phenylene units through the phenol rings. No linkage through the alkyl chain was observed, which proved a high chemo-selectivity of the enzyme. Aqueous solvents turned out to play an important role in the polymer production yield and molecular weight. With 2-propanol, the highest production yield (61%) of polymer (molecular weight = 3,900) was observed, and with methanol, higher-molecular-weight polymers (5,000) were produced with lower production yields (43%). The resulting polyanacardic acid was cross-linked on a solid surface to form a permanent natural polymer coating. The FTIR analysis indicates that the cross-linking between the polymers took place through the unsaturated alkyl side chains. The polyanacardic acid coating was then tested for its antibiofouling effect against Gram-negative and Gram-positive bacteria and compared with the antibiofouling effects of polycardanol coatings reported in the literature. The polyanacardic acid coating showed more reduction in biofilm formation on its surface than polycardanol coatings in the case of Gram-positive bacteria, while in the case of Gram-negative bacteria, it showed a similar reduction in biofilm formation as polycardanol.

  11. Evaluation of a virucidal quantitative carrier test for surface disinfectants.

    Directory of Open Access Journals (Sweden)

    Holger F Rabenau

    Full Text Available Surface disinfectants are part of broader preventive strategies preventing the transmission of bacteria, fungi and viruses in medical institutions. To evaluate their virucidal efficacy, these products must be tested with appropriate model viruses with different physico-chemical properties under conditions representing practical application in hospitals. The aim of this study was to evaluate a quantitative carrier assay. Furthermore, different putative model viruses like adenovirus type 5 (AdV-5 and different animal parvoviruses were evaluated with respect to their tenacity and practicability in laboratory handling. To evaluate the robustness of the method, some of the viruses were tested in parallel in different laboratories in a multi-center study. Different biocides, which are common active ingredients of surface disinfectants, were used in the test. After drying on stainless steel discs as the carrier, model viruses were exposed to different concentrations of three alcohols, peracetic acid (PAA or glutaraldehyde (GDA, with a fixed exposure time of 5 minutes. Residual virus was determined after treatment by endpoint titration. All parvoviruses exhibited a similar stability with respect to GDA, while AdV-5 was more susceptible. For PAA, the porcine parvovirus was more sensitive than the other parvoviruses, and again, AdV-5 presented a higher susceptibility than the parvoviruses. All parvoviruses were resistant to alcohols, while AdV-5 was only stable when treated with 2-propanol. The analysis of the results of the multi-center study showed a high reproducibility of this test system. In conclusion, two viruses with different physico-chemical properties can be recommended as appropriate model viruses for the evaluation of the virucidal efficacy of surface disinfectants: AdV-5, which has a high clinical impact, and murine parvovirus (MVM with the highest practicability among the parvoviruses tested.

  12. Combinatorial synthesis and screening of cancer cell-specific nanomedicines targeted via phage fusion proteins

    Directory of Open Access Journals (Sweden)

    James W. Gillespie

    2015-06-01

    Full Text Available Active tumor targeting of nanomedicines has recently shown significant improvements in the therapeutic activity of currently existing drug delivery systems, such as liposomal doxorubicin (Doxil/Caelyx/Lipodox. Previously, we have shown that isolated pVIII major coat proteins of the fd tet filamentous phage vector, containing cancer cell-specific peptide fusions at their N terminus, can be used as active targeting ligands in a liposomal doxorubicin delivery system in vitro and in vivo. Here, we show a novel major coat protein isolation procedure in 2-propanol that allows spontaneous incorporation of the hydrophobic protein core into preformed liposomal doxorubicin with minimal damage or drug loss while still retaining the targeting ligand exposed for cell-specific targeting. Using a panel of 12 structurally unique ligands with specificity towards breast, lung, and/or pancreatic cancer, we showed the feasibility of pVIII major coat proteins to significantly increase the throughput of targeting ligand screening in a common nanomedicine core. Phage protein-modified Lipodox samples showed an average doxorubicin recovery of 82.8% across all samples with 100% of protein incorporation in the correct orientation (N-terminus exposed. Following cytotoxicity screening in a doxorubicin-sensitive breast cancer line (MCF-7, three major groups of ligands were identified. Ligands showing the most improved cytotoxicity included: DMPGTVLP, ANGRPSMT, VNGRAEAP, and ANDVYLD showing a 25-fold improvement (p < 0.05 in toxicity. Similarly DGQYLGSQ, ETYNQPYL, and GSSEQLYL ligands with specificity towards a doxorubicin-insensitive pancreatic cancer line (PANC-1 showed significant increases in toxicity (2-fold; p < 0.05. Thus, we demonstrated proof-of-concept that pVIII major coat proteins can be screened in significantly higher throughput to identify novel ligands displaying improved therapeutic activity in a desired cancer phenotype.

  13. Measurement and correlation of solubility of hexamethylenetetramine in organic solvents%乌洛托品在有机溶剂中溶解度的测定与关联

    Institute of Scientific and Technical Information of China (English)

    李群生; 赵宇; 秦小勇; 王宝华; 易争明

    2012-01-01

    利用了一套有激光检测系统的实验设备,采用动态法测定了乌洛托品在甲醇、乙醇、正丙醇、异丙醇、正丁醇及正戊醇溶剂中,温度范围为278~334 K间的溶解度,并分别应用Apelblat方程、λh方程和Wilson方程对实验数据进行了关联.结果表明乌洛托品在6种实验溶剂中的溶解度都随温度的升高而增大,在甲醇中溶解度最大,拟合值与实验值的相对误差均在3%之内;Apelblat方程的关联效果最好.%The solubilities of hexamethylenetetramine in methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 1-pentanol between 278 and 334 K have been measured with a laser monitoring observation apparatus using the dynamic method. The experimental data were correlated with models based on the Apelblat equation, the λh equation and the Wilson equation. It was found that the Apelblat equation gave the best fit with the experimental data. The deviations between experimental and calculated data were less than 3%. It was found that the solubility increases with increasing temperature and the solubility is largest in methanol.

  14. Dechlorination of polychlorinated biphenyls in transformer oil using UV and visible light.

    Science.gov (United States)

    Kong, Jiansong; Achari, Gopal; Langford, Cooper H

    2013-01-01

    A study on dechlorination of PCB138 in transformer oil (TO) and 2-propanol (IPA) using 254 nm ultraviolet (UV) light as well as dye sensitized visible light has been conducted. Studies on dechlorination of polychlorinated biphenyls (PCBs) in TO using visible light in the presence of methylene blue (MB) and triethylamine (TEA) (providing a 'photocatalytic' cycle) in both deaerated and aerated conditions have been conducted to determine effects of TO, MB and TEA on reaction rates. The results show that photolytic methods are effective in treating PCBs in TO, and that the oil plays a limited adverse role. Under UV irradiation, PCB 138 can be >99% dechlorinated in the presence 0.06% (w/w) TO in IPA within 1 h with a rate constant of 0.0853 min(-1), while 47% of PCB138 can be dechlorinated in 92.1% (w/w) TO in IPA within 2 h with a rate constant of 0.0051 min(-1). In the 'photocatalytic' system, 94% reduction of PCB 138 was achieved within 30 min with a rate constant of 0.0968 min(-1) when the solvent was 60.70% (w/w) TO in IPA, while 71% dechlorination of PCB138 was achieved within 30 min with a rate constant of 0.0382 min(-1) when 81.62% (w/w) TO was present. In treatment of 30-73 ppm PCBs in TO, the optimal concentration of MB and TEA were found to be 0.5 g/L and 58.08 g/L respectively. Because of quenching by oxygen, deaeration of the solution is necessary for an efficient reaction. The photocatalytic system is especially adapted for treating lower concentration of PCBs in TO.

  15. Alcohol dispersions of calcium hydroxide nanoparticles for stone conservation.

    Science.gov (United States)

    Rodriguez-Navarro, Carlos; Suzuki, Amelia; Ruiz-Agudo, Encarnacion

    2013-09-10

    Alcohol dispersions of Ca(OH)2 nanoparticles, the so-called nanolimes, are emerging as an effective conservation material for the consolidation of stone, mortars, and plasters present in old masonry and/or mural paintings. To better understand how this treatment operates, to optimize its performance and broaden its applications, here we study the nano and microstructural characteristics, carbonation behavior, and consolidation efficacy of colloidal alcohol dispersions of Ca(OH)2 nanoparticles produced by both homogeneous (commercial nanolime) and heterogeneous phase synthesis (aged slaked lime and carbide lime putties). We observe that the alcohol not only provides a high colloidal stability to Ca(OH)2 particles, but also affects the kinetics of carbonation and CaCO3 polymorph selection. This is due to the pseudomorphic replacement of Ca(OH)2 particles by calcium alkoxides upon reaction with ethanol or 2-propanol. The extent of this replacement reaction depends on Ca(OH)2 size and time. Hydrolysis of alkoxides speeds up the carbonation process and increases the CaCO3 yield. The higher degree of transformation into calcium alkoxide of both the commercial nanolime and the carbide lime fosters metastable vaterite formation, while calcite precipitation is promoted upon carbonation of the aged slaked lime due its lower reactivity, which limits calcium alkoxide formation. A higher consolidation efficacy in terms of strength gain of treated porous stone is achieved in the latter case, despite the fact that the carbonation is much faster and reaches a higher yield in the former ones. Formation of alkoxides, which has been neglected in previous studies, needs to be considered when applying nanolime treatments. These results show that the use Ca(OH)2 nanoparticle dispersions prepared with either aged slaked lime or carbide lime putties is an economical and effective conservation alternative to commercial nanolimes produced by homogeneous phase synthesis. Ultimately, this

  16. TES buffer-induced phase separation of aqueous solutions of several water-miscible organic solvents at 298.15 K: phase diagrams and molecular dynamic simulations.

    Science.gov (United States)

    Taha, Mohamed; Lee, Ming-Jer

    2013-06-28

    Water and the organic solvents tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, 1-propanol, 2-propanol, tert-butanol, acetonitrile, or acetone are completely miscible in all proportions at room temperature. Here, we present new buffering-out phase separation systems that the above mentioned organic aqueous solutions can be induced to form two liquid phases in the presence of a biological buffer 2-[[1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl]amino]ethanesulfonic acid (TES). The lower liquid phase is rich in water and buffer, and the upper phase is organic rich. This observation has both practical and mechanistic interests. The phase diagrams of these systems were constructed by experimental measurements at ambient conditions. Molecular dynamic (MD) simulations were performed for TES + water + THF system to understand the interactions between TES, water, and organic solvent at molecular level. Several composition-sets for this system, beyond and inside the liquid-liquid phase-splitting region, have been simulated. Interestingly, the MD simulation for compositions inside the phase separation region showed that THF molecules are forced out from the water network to start forming a new liquid phase. The hydrogen-bonds, hydrogen-bonds lifetimes, hydrogen-bond energies, radial distribution functions, coordination numbers, the electrostatic interactions, and the van der Waals interactions between the different pairs have been calculated. Additionally, MD simulations for TES + water + tert-butanol∕acetonitrile∕acetone phase separation systems were simulated. The results from MD simulations provide an explanation for the buffering-out phenomena observed in [TES + water + organic solvent] systems by a mechanism controlled by the competitive interactions of the buffer and the organic solvent with water. The molecular mechanism reported here is helpful for designing new benign separation materials.

  17. Abscisic Acid accumulation in spinach leaf slices in the presence of penetrating and nonpenetrating solutes.

    Science.gov (United States)

    Creelman, R A; Zeevaart, J A

    1985-01-01

    Abscisic acid (ABA) accumulated in detached, wilted leaves of spinach (Spinacia oleracea L. cv Savoy Hybrid 612) and reached a maximum level within 3 to 4 hours. The increase in ABA over that found in detached turgid leaves was approximately 10-fold. The effects of water stress could be mimicked by the use of thin slices of spinach leaves incubated in the presence of 0.6 molar mannitol, a compound which causes plasmolysis (loss of turgor). About equal amounts of ABA were found both in the leaf slices and in detached leaves, whereas 2 to 4 times more ABA accumulated in the medium than in the slices. When spinach leaf slices were incubated with ethylene glycol, a compound which rapidly penetrates the cell membrane causing a decrease in the osmotic potential of the tissue and only transient loss of turgor, no ABA accumulated. Ethylene glycol was not inhibitory with respect to ABA accumulation. Spinach leaf slices incubated in both ethylene glycol and mannitol had ABA levels similar to those found when slices were incubated with mannitol alone. Increases similar to those found with mannitol also occurred when Aquacide III, a highly purified form of polyethylene glycol, was used. Aquacide III causes cytorrhysis, a situation similar to that found in wilted leaves. Thus, it appears that loss of turgor is essential for ABA accumulation.When spinach leaf slices were incubated with solutes which are supposed to disturb membrane integrity (KHSO(3), 2-propanol, or KCl) no increase in ABA was observed. These data indicate that, with respect to the accumulation of ABA, mannitol caused a physical stress (loss of turgor) rather than a chemical stress (membrane damage).

  18. Novel coupled structures of FeWO4/TiO2 and FeWO4/TiO2/CdS designed for highly efficient visible-light photocatalysis.

    Science.gov (United States)

    Bera, Sandipan; Rawal, Sher Bahadur; Kim, Hark Jin; Lee, Wan In

    2014-06-25

    A quadrilateral disk-shaped FeWO4 nanocrystal (NC) with an average size of ∼35 nm was prepared via hydrothermal reaction. The obtained dark brown FeWO4 NC with a bandgap (Eg) of 1.98 eV was then coupled with TiO2 to form FeWO4/TiO2 composites. The valence band (VB) of FeWO4 (+2.8 eV vs NHE) was more positive than that of TiO2 (+2.7 eV); thus this system could be classified as a Type-B heterojunction. Under visible-light irradiation, 5/95 FeWO4/TiO2 (by wt %) exhibited remarkable photocatalytic activity: the amount of CO2 evolved from gaseous 2-propanol (IP) and the decomposition rate of aqueous salicylic acid (SA) were, respectively, 1.7 and 2.5 times greater than those of typical nitrogen-doped TiO2 (N-TiO2). This unique catalytic property was deduced to arise from the intersemiconductor hole transfer between the VBs of FeWO4 and TiO2. Herein, several experimental evidence were also provided to confirm the hole-transfer mechanism. To further enhance the catalytic efficiency, double-heterojunctioned FeWO4/TiO2/CdS composites were prepared by loading CdS quantum dots (QDs) onto the FeWO4/TiO2 surface. Surprisingly, the catalytic activity for evolving CO2 from IP was 2.6 times greater than that of bare FeWO4/TiO2 and 4.4 times greater than that of N-TiO2, suggesting that both holes and electrons were essential species in decomposing organic compounds.

  19. Chitosan and chitosan chlorhydrate based various approaches for enhancement of dissolution rate of carvedilol

    Directory of Open Access Journals (Sweden)

    Shete Amol S

    2012-12-01

    Full Text Available Abstract Background and the purpose of the study Carvedilol nonselective β-adrenoreceptor blocker, chemically (±-1-(Carbazol-4-yloxy-3-[[2-(o-methoxypHenoxy ethyl] amino]-2-propanol, slightly soluble in ethyl ether; and practically insoluble in water, gastric fluid (simulated, TS, pH 1.1, and intestinal fluid (simulated, TS without pancreatin, pH 7.5 Compounds with aqueous solubility less than 1% W/V often represents dissolution rate limited absorption. There is need to enhance the dissolution rate of carvedilol. The objective of our present investigation was to compare chitosan and chitosan chlorhydrate based various approaches for enhancement of dissolution rate of carvedilol. Methods The different formulations were prepared by different methods like solvent change approach to prepare hydrosols, solvent evaporation technique to form solid dispersions and cogrind mixtures. The prepared formulations were characterized in terms of saturation solubility, drug content, infrared spectroscopy (FTIR, differential scanning calorimetry (DSC, powder X-ray diffraction (PXRD, electron microscopy, in vitro dissolution studies and stability studies. Results The practical yield in case of hydrosols was ranged from 59.76 to 92.32%. The drug content was found to uniform among the different batches of hydrosols, cogrind mixture and solid dispersions ranged from 98.24 to 99.89%. There was significant improvement in dissolution rate of carvedilol with chitosan chlorhdyrate as compare to chitosan and explanation to this behavior was found in the differences in the wetting, solubilities and swelling capacity of the chitosan and chitosan salts, chitosan chlorhydrate rapidly wet and dissolve upon its incorporation into the dissolution medium, whereas the chitosan base, less water soluble, would take more time to dissolve. Conclusion This technique is scalable and valuable in manufacturing process in future for enhancement of dissolution of poorly water soluble

  20. Local sustained delivery of acetylsalicylic acid via hybrid stent with biodegradable nanofibers reduces adhesion of blood cells and promotes reendothelialization of the denuded artery.

    Science.gov (United States)

    Lee, Cheng-Hung; Lin, Yu-Huang; Chang, Shang-Hung; Tai, Chun-Der; Liu, Shih-Jung; Chu, Yen; Wang, Chao-Jan; Hsu, Ming-Yi; Chang, Hung; Chang, Gwo-Jyh; Hung, Kuo-Chun; Hsieh, Ming-Jer; Lin, Fen-Chiung; Hsieh, I-Chang; Wen, Ming-Shien; Huang, Yenlin

    2014-01-01

    Incomplete endothelialization, blood cell adhesion to vascular stents, and inflammation of arteries can result in acute stent thromboses. The systemic administration of acetylsalicylic acid decreases endothelial dysfunction, potentially reducing thrombus, enhancing vasodilatation, and inhibiting the progression of atherosclerosis; but, this is weakened by upper gastrointestinal bleeding. This study proposes a hybrid stent with biodegradable nanofibers, for the local, sustained delivery of acetylsalicylic acid to injured artery walls. Biodegradable nanofibers are prepared by first dissolving poly(D,L)-lactide-co-glycolide and acetylsalicylic acid in 1,1,1,3,3,3-hexafluoro-2-propanol. The solution is then electrospun into nanofibrous tubes, which are then mounted onto commercially available bare-metal stents. In vitro release rates of pharmaceuticals from nanofibers are characterized using an elution method, and a highperformance liquid chromatography assay. The experimental results suggest that biodegradable nanofibers release high concentrations of acetylsalicylic acid for three weeks. The in vivo efficacy of local delivery of acetylsalicylic acid in reducing platelet and monocyte adhesion, and the minimum tissue inflammatory reaction caused by the hybrid stents in treating denuded rabbit arteries, are documented. The proposed hybrid stent, with biodegradable acetylsalicylic acid-loaded nanofibers, substantially contributed to local, sustained delivery of drugs to promote re-endothelialization and reduce thrombogenicity in the injured artery. The stents may have potential applications in the local delivery of cardiovascular drugs. Furthermore, the use of hybrid stents with acetylsalicylic acid-loaded nanofibers that have high drug loadings may provide insight into the treatment of patients with high risk of acute stent thromboses.

  1. Formal approaches to information hiding: An analysis of interactive systems, statistical disclosure control, and refinement of specifications

    Science.gov (United States)

    Armijo, Kenneth Miguel

    This research investigates the impact of Marangoni phenomena, with low mixture concentrations of alcohol and water, to enhance thermal transport capability of gravity-assisted heat pipes. The use of binary mixture working fluids in gravity-assisted heat pipes are shown to improve the critical heat flux (CHF) and operating performance, more so than with pure fluids. The CHF is responsible for dryout when the pumping rate of a liquid flow structure is not sufficient to provide enough fluid to the evaporator section. In the first study, heat pipe performance experiments were conducted for pure water and 2-propanol solutions with varying concentrations. Initial tests with pure water determined the optimal working fluid charge for the heat pipe; subsequent performance tests over a wide range of heat input levels were then conducted for each working fluid at this optimum value. The results indicated that some mixtures significantly enhance the heat transfer coefficient and heat flux capability of the heat pipe evaporator. For the best mixture tested, the maximum evaporator heat flux carried by the coolant without dryout was found to be 52% higher than the value for the same heat pipe using pure water as a coolant under comparable conditions. Peak evaporator heat flux values above 100 W/cm2 were achieved with some mixtures. Evaporator and condenser heat transfer coefficient data are presented and the trends are examined in the context of the expected effect of the Marangoni mechanisms on heat transfer. A second experimental study was also performed of a 37° inclined, gravity-assisted, brass heat pipe with a 0.05M 2-Propanol/water binary mixture. The device design was developed from the first study by enlarging the evaporator and condenser surface areas. Strip heaters were also employed to provide larger input heat flux levels, for enhanced heat pipe performance testing. These experiments were carried out for varying liquid charge ratios between 30% and 70%, to determine

  2. Validation of scaffold design optimization in bone tissue engineering: finite element modeling versus designed experiments.

    Science.gov (United States)

    Uth, Nicholas; Mueller, Jens; Smucker, Byran; Yousefi, Azizeh-Mitra

    2017-02-21

    This study reports the development of biological/synthetic scaffolds for bone tissue engineering (TE) via 3D bioplotting. These scaffolds were composed of poly(L-lactic-co-glycolic acid) (PLGA), type I collagen, and nano-hydroxyapatite (nHA) in an attempt to mimic the extracellular matrix of bone. The solvent used for processing the scaffolds was 1,1,1,3,3,3-hexafluoro-2-propanol. The produced scaffolds were characterized by scanning electron microscopy, microcomputed tomography, thermogravimetric analysis, and unconfined compression test. This study also sought to validate the use of finite-element optimization in COMSOL Multiphysics for scaffold design. Scaffold topology was simplified to three factors: nHA content, strand diameter, and strand spacing. These factors affect the ability of the scaffold to bear mechanical loads and how porous the structure can be. Twenty four scaffolds were constructed according to an I-optimal, split-plot designed experiment (DE) in order to generate experimental models of the factor-response relationships. Within the design region, the DE and COMSOL models agreed in their recommended optimal nHA (30%) and strand diameter (460 μm). However, the two methods disagreed by more than 30% in strand spacing (908 μm for DE; 601 μm for COMSOL). Seven scaffolds were 3D-bioplotted to validate the predictions of DE and COMSOL models (4.5-9.9 MPa measured moduli). The predictions for these scaffolds showed relative agreement for scaffold porosity (mean absolute percentage error of 4% for DE and 13% for COMSOL), but were substantially poorer for scaffold modulus (51% for DE; 21% for COMSOL), partly due to some simplifying assumptions made by the models. Expanding the design region in future experiments (e.g., higher nHA content and strand diameter), developing an efficient solvent evaporation method, and exerting a greater control over layer overlap could allow developing PLGA-nHA-collagen scaffolds to meet the mechanical requirements for

  3. 氟碳化合物等离子体处理丝绸织物的表面分析%The surface properties of silk fabrics treated by fluorocarbon compound plasma

    Institute of Scientific and Technical Information of China (English)

    沈丽; 朱泉; 曹淑华

    2013-01-01

    Silk fabrics were treated by low temperature plasma with fluorocarbons such as hexafluoropro-pene, perfluoroheptane, perfluorocyclobutane, perfluorooctyl ethylene, 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2, 2-trifluoroethanol. The water and oil repellency of silk treated by fluorocarbon plasma was investigated. The changes of element composition and functional groups before and after treatment were characterized by X-ray photoelectron spectroscopy (XPS). Certain amounts of fluorine atoms were introduced to the surface of fluorocarbon plasma treated silk fabrics, which increased the water repellency of silk fabrics. C1s spectra showed that -CF, -CF2 and -CF3 groups were introduced to the silk surface. The fluoro containing groups on the silk fabrics surface varied with the kinds of fluorocarbon compounds, which indicated that the binding modes with silk fabric surface changed with the structures of fluorocarbon compounds.%以六氟丙烯、全氟庚烷、八氟环丁烷、全氟辛基乙烯、1,1,1,3,3,3-六氟-2-丙醇和2,2,2-三氟乙醇等氟碳化合物为气氛对丝绸织物进行等离子体处理,考察处理后丝绸织物的拒水拒油性能,利用X射线光电子能谱(XPS)分析等离子体处理前后元素组成及官能团的变化.不同氟碳化合物等离子体处理后在织物表面引入了一定量的氟元素,织物的拒水性能增加.Cls谱图表明在织物表面引入了—CF、—CF2和—CF3基团,不同氟碳化合物引入到织物表面的含氟基团有所不同,说明化合物结构不同使在丝绸织物表面的结合方式有所区别.

  4. Insufficient neutralization in testing a chlorhexidine-containing ethanol-based hand rub can result in a false positive efficacy assessment

    Directory of Open Access Journals (Sweden)

    Kampf Günter

    2005-06-01

    Full Text Available Abstract Background Effective neutralization in testing hand hygiene preparations is considered to be a crucial element to ensure validity of the test results, especially with the difficulty to neutralize chlorhexidine gluconate. Aim of the study was to measure the effect of chemical neutralization under practical test conditions according to EN 1500. Methods We have investigated two ethanol-based hand rubs (product A, based on 61% ethanol and 1% chlorhexidine gluconate; product B, based on 85% ethanol. The efficacy of products (application of 3 ml for 30 s was compared to 2-propanol 60% (v/v (two 3 ml rubs of 30 s each on hands artificially contaminated with Escherichia coli using a cross-over design with 15 volunteers. Pre-values were obtained by rubbing fingertips for 1 minute in liquid broth. Post-values were determined by sampling immediately after disinfection in liquid broth with and without neutralizers (0.5% lecithin, 4% polysorbate 20. Results The neutralizers were found to be effective and non-toxic. Without neutralization in the sampling fluid, the reference disinfection reduced the test bacteria by 3.7 log10, product B by 3.3 log10 and product A by 4.8 log10 (P = 0.001; ANOVA. With neutralization the reference disinfection reduced the test bacteria by 3.5 log10, product B by 3.3 log10 and product A by 2.7 log10 (P = 0.011; ANOVA. In comparison to the reference treatment Product B lead to a lower mean reduction than the reference disinfection but the difference was not significant (P > 0.1; Wilcoxon-Wilcox test. Without neutralizing agents in the sampling fluid, product A yielded a significantly higher reduction of test bacteria (4.8; P = 0.02 as compared to the situation with neutralizing agents (2.7; P = 0.033. Conclusion The crucial step of neutralization lies in the sampling fluid itself in order to stop any residual bacteriostatic or bactericidal activity immediately after the application of the preparation, especially with

  5. 虎纹捕鸟蛛丝蛋白/丝素复合纤维的结构与力学性能%Structure and mechanical properties of electrospun Ornithoctonus huwenna spidroin/silk compound fiber

    Institute of Scientific and Technical Information of China (English)

    张敏; 张野妹; 朱仁宽; 吴维; 张爱丽; 潘志娟

    2011-01-01

    Spidroin / silk composite nano-fibers were obtained by electrospinning of the mixed solution of Ornithoctonus huwenna spider silk / 1,1,1,3,3,3, -hexafluoro-2-propanol ( HFIP) and silk / HFIP. The effect of mixing ratio of spidroin and silk on the morphology, molecular conformations, and crystallinity of the electrospun fibers were investigated by means of SEM , FT-IR, XRD, and the enhancement effect of spidroin on the mechanical property of the electrospun fibers were analyzed. The results indicated that increasing the content of spidroin attenuated the fiber diameter significantly and increased the number of fibers with a diameter < 300 nm. Addition of certain amount of spidroin is beneficial to the improvement of the mechanical property of the electrospun silk fiber mat. The FT-IR and XRD analyses showed that the mass fraction of spidroin has no regular influence on the content of conformation molecules, such as β-fold, random crimp, α-spiral and β-angle, of the fiber.%以虎纹捕鸟蛛丝/六氟异丙醇(HFIP)和丝素/HFIP的混合液为纺丝液,制备了虎纹捕鸟蛛丝蛋白/丝素复合纳米纤维,并通过SEM、FT-IR、XRD研究蜘蛛丝蛋白和丝素的混合比例对纤维形态结构、分子构象、结晶结构的影响,分析蜘蛛丝蛋白对静电纺丝素纤维的力学增强效应.结果表明:随蛛丝蛋白含量的增加,复合纤维的平均直径明显减小,直径小于300 nm的纤维数量增加;添加一定量的蜘蛛丝蛋白有助于改善静电纺丝素纤维毡的力学性能.FT-IR和XRD谱图都表明,蜘蛛丝蛋白的质量分数对复合纤维中β-折叠、无规卷曲、α-螺旋和β-转角构象分子的含量均无规律性的影响.

  6. Influence of electrospinning on microstructure of regenerated Argiope bruennichi silk%静电纺再生加工对横纹金珠丝微观结构的影响

    Institute of Scientific and Technical Information of China (English)

    裔婷婷; 潘志娟

    2012-01-01

    蜘蛛丝因其优异的力学性能和良好的生物相容性引起了学者的广泛关注.为此在研究横纹金珠丝在六氟异丙醇(HFIP)中溶解性能的基础上,采用静电纺丝的方法制备再生横纹金珠丝(框丝、卵袋内层丝、卵袋外层丝),分析比较再生横纹金蛛丝和天然横纹金蛛丝在形态结构、分子构象、结晶结构以及热稳定性方面的差异.结果发现:静电纺再生框丝呈扁平带状,带宽为(751±196) nm,卵袋内层丝和卵袋外层丝直径分别为(141±46) nm和(105±37)nm.X衍射图谱和TG-DTA测定结果表明,静电纺再生加工后,横纹金珠丝结构由silkⅡ向silk Ⅰ转变,结晶度下降,主要热分解温度降低.%Spider silk has attracted wide attentions of scholars and researchers due to its excellent mechanical properties and good biocompatibility in recent years. The regenerated Argiope bruennichi silk ( scaffolding silk, egg case inner cover silk, egg case outer cover silk) was prepared by electrospinning on the basis of studying the solubility of Argiope bruennichi silk in 1,1,1,3 ,3 ,3-hexafluoro-2-propanol (HFIP). The morphology, molecular conformation, crystallinity and thermal property of the natural Argiope bruennichi silk and the electrospun Argiope bruennichi silk were compared. The results indicated the electrospun regenerated Argiope bruennichi silk was flat ribbon with the bandwidth ( 751 ± 196 ) nm and a diameter of egg case inner cover silk and egg case outer cover silk (141 ±46) nm and ( 105 ± 37) nm, respectively. The XRD and TG-DTA analysis showed that the crystal structure of electrospun Argiope bruennichi silk has changed from silk II to silk I , and the crystallinity and main thermal decomposition temperature decreased.

  7. 变形杆菌属脂肪酶LipK107的分离纯化、结晶及初步晶体学分析%Purification,crystallization and preliminary crystallographic analysis of a lipase from Proteus sp.K107

    Institute of Scientific and Technical Information of China (English)

    戚宝杰; 刘清海; 谢静莉; 魏东芝

    2012-01-01

    After induced by IPTG,the recombinant E.coli expressed Lipase LipK107 as HisX6 fusion protein.High purity enzyme was obtained by affinity chromatography and gel filtration chromatography.Purified lipase was analyzed by circular dichrosim(CD)in order to reveal the secondary structure composition of lipase LipK107.Then,purified lipase was crystallized by the hanging-drop vapour-diffusion method.High quality crystals were obtained using 0.1mol/L sodium citrate tribasic dihydrate pH6.2,10% v/v 2-propanol,15% w/v polyethylene glycol 4000 as precipitant.X-ray diffraction data was collected to 2.0 using synchrotron radiation.%经过异丙基-β-D-硫代吡喃半乳糖苷(IPTG)诱导,重组大肠杆菌高效表达出带有组氨酸标签的可溶性脂肪酶LipK107。通过亲和层析和凝胶层析两步法纯化,得到电泳纯的脂肪酶样品。在获得的纯酶基础上,进行了圆二色谱实验,以分析脂肪酶LipK107的二级结构组成。接着,使用悬滴气相扩散法进行了纯酶的结晶实验,经过晶体生长条件的初步筛选及优化,在0.1mol/L pH6.2柠檬酸钠,10%v/v异丙醇,15%w/v聚乙二醇4000条件下得到高质量的脂肪酶晶体,使用同步辐射光源收集了一套分辨率为2.0的X-射线衍射数据。

  8. 甘油合成1,3-丙二醇%Synthesis of 1,3-Propanediol from Glycerol

    Institute of Scientific and Technical Information of China (English)

    陈国辉; 孙全

    2011-01-01

    1,3-Propanediol was synthesized from glycerol by chloration,oxidation, Clemmensen reaction and hydrolysis. The structure of the target compound was determined by method of IR and MS. The molar ratio, temperature and solvent of the reaction were investigated to optimize the reaction conditions. The optimum conditions are: for chloration: 120 ℃; for oxidation: 23 ~ 27 ℃, n ( 1,3-dichloroacetone ): n ( sodium dichromate) = 1.8:1, the amount of reaction solvent: 1.4 g 1,3-dichloro-2-propanol per 1 mL water, and for Clemmensen reaction: n (1,3-dichloropropane): n ( zinc )= 1:1.2, with water as the desirable solvent, and the overall yield of 37. 1%.%以甘油为原料,经过氯代、氧化、克莱门森还原、水解4步反应,最终合成1,3-丙二醇,并用红外光谱仪和质谱仪对目标产物进行结构确定.从反应物摩尔比、反应温度、反应溶剂等优化了反应条件.最优反应条件为:氯代反应:温度120℃;氧化反应:温度23~27℃,,n(1,3-二氯-2-丙醇):n(重铬酸钠)=1.8:1,反应溶剂用量:1 mL水溶解1.4 g 1,3-二氯-2-丙醇;克莱门森还原反应:n(1,3-二氯丙酮):n(锌)=1:1.2,水作反应溶剂最佳,在该条件下,1,3-丙二醇总产率可达37.1%.

  9. Measuring acetic and formic acid by proton transfer reaction-mass spectrometry: sensitivity, humidity dependence, and quantifying interferences

    Directory of Open Access Journals (Sweden)

    M. Baasandorj

    2014-10-01

    Full Text Available We present a detailed investigation of the factors governing the quantification of formic acid (FA, acetic acid (AA and their relevant mass analogues by proton transfer reaction-mass spectrometry (PTR-MS, assess the underlying fragmentation pathways and humidity dependencies, and present a new method for separating FA and AA from their main isobaric interferences. PTR-MS sensitivities towards glycolaldehyde, ethyl acetate and peroxyacetic acid at m/z 61 are comparable to that for AA; when present, these species will interfere with ambient AA measurements by PTR-MS. Likewise, when it is present, dimethyl ether can interfere with FA measurements. On the other hand, for E/N = 125 Townsend (Td, the PTR-MS sensitivity towards ethanol at m/z 47 is 5–20× lower than for FA; ethanol will then only be an important interference when present in much higher abundance than FA. Sensitivity towards 2-propanol is m/z 79, which is also commonly used to measure benzene. However, the resulting interference for benzene is only significant when E/N is low (E/N, but decreases with humidity at high E/N due to water-driven fragmentation. Sensitivity towards FA decreases with humidity throughout the full range of E/N. For glycoaldehyde and the alcohols, the sensitivity increases with humidity due to ligand switching reactions (at low E/N and reduced fragmentation in the presence of water (at high E/N. Their role as interferences will typically be greatest at high humidity. For compounds such as AA where the humidity effect depends strongly on the collisional energy in the drift tube, simple humidity correction factors (XR will only be relevant for a specific instrumental configuration. We recommend E/N∼125 Td as an effective condition for AA and FA measurements by PTR-MS, as it optimizes between the competing E/N-dependent mechanisms controlling their sensitivities and those of the interfering species. Finally, we present the design and evaluation of an online acid

  10. Enantiomeric separation and simulation studies of pheniramine, oxybutynin, cetirizine, and brinzolamide chiral drugs on amylose-based columns.

    Science.gov (United States)

    Ali, Imran; Al-Othman, Zeid A; Al-Warthan, Abdulrahman; Alam, Syed Dilshad; Farooqi, Javed A

    2014-03-01

    Solid phase extraction (SPE)-chiral separation of the important drugs pheniramine, oxybutynin, cetirizine, and brinzolamide was achieved on the C18 cartridge and AmyCoat (150 x 46 mm) and Chiralpak AD (25 cm x 0.46 cm id) chiral columns in human plasma. Pheniramine, oxybutynin, cetirizine, and brinzolamide were resolved using n-hexane-2-PrOH-DEA (85:15:0.1, v/v), n-hexane-2-PrOH-DEA (80:20:0.1, v/v), n-hexane-2-PrOH-DEA (70:30:0.2, v/v), and n-hexane-2-propanol (90:10, v/v) as mobile phases. The separation was carried out at 25 ± 1 ºC temperature with detection at 225 nm for cetirizine and oxybutynin and 220 nm for pheniramine and brinzolamide. The flow rates of the mobile phases were 0.5 mL min(-1). The retention factors of pheniramine, oxybutynin, cetirizine and brinzolamide were 3.25 and 4.34, 4.76 and 5.64, 6.10 and 6.60, and 1.64 and 2.01, respectively. The separation factors of these drugs were 1.33, 1.18, 1.09 and 1.20 while their resolutions factors were 1.09, 1.45, 1.63 and 1.25, and 1.15, respectively. The absolute configurations of the eluted enantiomers of the reported drugs were determined by simulation studies. It was observed that the order of enantiomers elution of the reported drugs was S-pheniramine > R-pheniramine; R-oxybutynin > S-oxybutynin; S-cetirizine > R-cetirizine; and S-brinzolamide > R-brinzolamide. The mechanism of separation was also determined at the supramolecular level by considering interactions and modeling results. The reported SPE-chiral high-performance liquid chromatography (HPLC) methods are suitable for the enantiomeric analyses of these drugs in any biological sample. In addition, simulation studies may be used to determine the absolute configuration of the first and second eluted enantiomers.

  11. A new low-molecular-weight organogelator based on long chain substituted phenyl Schiff base%一种席夫碱凝胶因子的制备及凝胶化研究

    Institute of Scientific and Technical Information of China (English)

    陈发胜; 薛伟; 郭敏; 尹桂

    2009-01-01

    We report on the synthesis and self-assembly of a Schiff-based molecules N, N'-[1, 4-phenylenebis (methan-1-yl-1-ylidene)]bis[3,4,5-tris(dodecyloxy)aniline] (PBBA). It was found that PBBA could form stable gels in several weak polar solvents such as benzyl alcohol, octanol, 1-butanol and 2-propanol. The gel-to-solution phase-transition temperatures (Tg) of gels in selected solvents increase with the enhancing of gelator concentration. Scanning electron microscopy (SEM) images revealed that their xerogel morphologies were aggregations of fibers. The results from fourier trasform infrared spectrometry(FT-IR) indicated that the van der Waals interaction between the alkyl chains and n - n interactions were the main driving forces for the formation of the self-assembled gels. Further detailed analyses of their aggregation modes were conducted by X-ray diffraction (XRD) measurements. The most prominent features are reflections at 2θ=32°, which are assigned to van der Waals interactions between alkyl chains with a mean distance of 2. 796 4 A. The peak at 2θ=22° indicates another unit with a typical distance of 4. 039 6 A, which is assumed to correspond to π-π stacking interactions.%合成并表征了一种可自组装的Schiff碱凝胶因子(gelator)N,N'-(1,4-苯基二亚甲基叶立德)-二[3,4,5-三(十二烷氧基)苯胺](简称PBBA);研究了该凝胶因子在一些有机溶剂中凝胶化性能;用傅里叶变换红外光谱(FT-IR)、X射线衍射(XRD)、扫描电镜(SEM)等分析方法对凝胶进行了表征;研究了不同浓度的凝胶因子对溶胶-凝胶以及凝胶-溶胶转变温度的影响.研究表明该凝胶因子是通过范德华力,π-π堆积等次价键的作用而聚集自组装成三维网状结构,再与溶剂相互作用形成凝胶的.

  12. Seasonal variations of particle-associated nitrosamines by gas chromatography-mass spectrometry in the atmospheric environment of Zonguldak, Turkey.

    Science.gov (United States)

    Akyüz, Mehmet; Ata, Şevket

    2013-10-01

    A gas chromatography-mass spectrometry method has been proposed for the determination of low-level mutagenic and carcinogenic nitrosamines in particulate matter. The method includes the collection of particulate matters (PM2.5 and PM10) using a dichotomous Partisol 2025 sampler and extraction of the compounds from aqueous solution with dichloromethane/2-propanol after sonication with a slightly basic water solution prior to their GC-MS analysis in electron impact mode. The obtained recoveries of nitrosamines ranged from 92.4 to 99.2 %, and the precision of this method, as indicated by the relative standard deviations, was within the range of 0.95-2.46 %. The detection limits obtained from calculations using the GC-MS results based on S/N=3 were found within the range from 4 to 22 pg/m(3). The predominant nitrosamines determined in particulate matter were N-nitrosodimethylamine, N-nitrosodiethylamine, N-nitrosodibutylamine and N-nitrosomorpholine. Furthermore, N-mono- and dinitrosopiperazine and N-nitrosoethylbutylamine were also determined. N-dinitrosopiperazine was detected in PM2.5 samples at the highest concentrations of up to 22.85 ng/m(3) and in PM2.5-10 samples at concentrations up to 7.60 ng/m(3) in winter, whereas it was found in PM2.5 samples up to 5.15 ng/m(3) and in PM2.5-10 samples up to 3.12 ng/m(3) in summer. The total concentrations of nitrosamines were up to 161.4 ng/m(3) in fine and 53.90 ng/m(3) in coarse fractions in winter, whereas in summer were up to 35.24 and 12.60 ng/m(3), respectively. The concentration levels of nitrosamines fluctuated significantly within a year, with higher means and peak concentrations in the winter compared to that in the summertime. The seasonal variations of particle-associated nitrosamine concentrations were investigated together with their relationships with meteorological parameters using Pearson's correlation analysis in the winter and summer periods. Analysis of variance was used to determine which

  13. Visible-light-driven Cu(II)-(Sr(1-y)Na(y))(Ti(1-x)Mo(x))O3 photocatalysts based on conduction band control and surface ion modification.

    Science.gov (United States)

    Qiu, Xiaoqing; Miyauchi, Masahiro; Yu, Huogen; Irie, Hiroshi; Hashimoto, Kazuhito

    2010-11-03

    Band-gap narrowing is generally considered to be a primary method in the design of visible-light-active photocatalysts because it can decrease the photo threshold to lower energies. However, controlling the valence band by up-shifting the top of the band or inducing localized levels above the band results in quantum efficiencies under visible light much lower than those under UV irradiation (such as those reported for N-doped TiO(2): Science 2001, 293, 269. J. Phys. Chem. B 2003, 107, 5483). Herein, we report a systematic study on a novel, visible-light-driven photocatalyst based on conduction band control and surface ion modification. Cu(II)-(Sr(1-y)Na(y))(Ti(1-x)Mo(x))O(3) photocatalysts were prepared by a soft chemical method in combination with an impregnation technique. It is found that Mo(6+) as well as Na(+) doping in the SrTiO(3) can lower the bottom of the conduction band and effectively extend the absorption edge to the visible light region. The Cu(II) clusters grafted on the surface act as a co-catalyst to efficiently reduce the oxygen molecules, thus consuming the excited electrons. Consequently, photocatalytic decomposition of gaseous 2-propanol into CO(2) is achieved, that is, CH(3)CHOHCH(3) + (9)/(2)O(2) → 3CO(2) + H(2)O. For Cu(II)-(Sr(1-y)Na(y))(Ti(1-x)Mo(x))O(3) at x = 2.0% under visible light irradiation, the maximum CO(2) generation rate can reach 0.148 μmol/h; the quantum efficiency under visible light is calculated to be 14.5%, while it is 10% under UV light irradiation. Our results suggest that high visible light photocatalytic efficiency can be achieved by combining conduction band control and surface ion modification, which provides a new approach for rational design and development of high-performance photocatalysts.

  14. HPLC法测定左亚叶酸钙中的右旋异构体△%Determination of dextroisomer in Calcium levofolinate by HPLC

    Institute of Scientific and Technical Information of China (English)

    刘凤丽; 沈园园

    2013-01-01

      目的:建立测定左亚叶酸钙原料药中右旋异构体含量的高效液相色谱方法。方法:采用CHIRAL-HSA色谱柱(150mm×4.0mm,5μm),流动相为0.1mol·L-1磷酸二氢钠缓冲液(用氢氧化钠溶液调节pH至5.0)-异丙醇-乙腈(890∶95∶15);流速为1.0mL·min-1;检测波长为286nm;柱温为40℃。结果:在1.5~10.0μg·mL-1范围内线性回归方程为Y=29.125X-1.0025(r=1.0000),平均回收率为100.1%(RSD=0.8%,n=9)。结论:该方法操作简便、灵敏度高、重复性好。%Objietive:To establish a HPLC method for determination the content of dextroisomer in Calcium levofolinate. Methods:The separation was performed on a human albumin coated silica gel column (150mm×4.0mm,5μm). The mobile phase was 0.1mol·L-1 sodium dihydrogen Phosphate buffer(adjust to pH 5.0 with sodium hydroxide solution)-2-propanol-acetonitrile(890:95:15).The flow rate was 1.0 mL·min-1. Ultraviolet absorption detector was set at 286 nm and column temperature was at 40℃. Results: The linear range of dextroisomer was between 1.5 and 10.0 μg·mL-1 (r=1.0000). The average recovery was 100.1 % with RSD was 0.8%. Conclusions:A reproducible and specific method is provided for the content of dextroisomer in Calcium levofolinate .

  15. NaBr, NaCl和KBr在几种有机溶剂中活度系数的测定%Activity Coefficient Measurement of NaBr, NaCl and KBr in Selected Organic Solvents

    Institute of Scientific and Technical Information of China (English)

    姜波; 王利生; 李弥异

    2011-01-01

    In this paper, the conductivities of NaBr in methanol, ethanol, 1-propanol, 2-propanol, NaC1 and KBr in methanol, ethanol system (solution concentration within 0. 1 mol· L-1 ) were determined at 298.15 K, 313.15 K and 323.15 K at atmosphere pressure respectively. The mean ion activity coefficients of NaBr, NaC1 and KBr in various organic solvents were calculated according to DebyeHacker limiting law and Onsager-Falkenhangen equations. The effects of concentration and temperature on activity coefficients of electrolyte solutions were discussed. The calculated results were compared with those of NaBr in ethanol, NaC1 in methanol and KBr in methanol reported in literature. The results show that the experimental data obtained by conductivity method have good agreement with data in literature.%分别测定了NaBr在甲醉、乙醇、正丙醉和异丙醇中,NaCI和KBr在甲醉和乙醉中共8个体系(溶液物质的量的浓度在0.1 mol·L(-1)范围内)在298.15,313.15和323.15 K下的电导率,利用Debye-Hiicker和Osager-Falkenhangen公式计算了以上溶液体系的平均离子活度系数,讨论了浓度和温度对电解质溶液活度系数的影响.其中NaBr在乙醇中,NaCI在甲醉中和KBr在甲醇中的平均离子活度系数的计算结果与已发表文献中的数据进行了比较.结果表明,该方法的活度系数结果与文献数据有较好的一致性.

  16. Incipient flocculation molding: A new ceramic-forming technique

    Science.gov (United States)

    Arrasmith, Steven Reade

    Incipient Flocculation Molding (IFM) was conceived as a new near-net-shape forming technique for ceramic components. It was hypothesized that the development of a temperature-dependent deflocculant would result in a forming technique that is flexible, efficient, and capable of producing a superior microstructure with improved mechanical properties from highly reactive, submicron ceramic powders. IFM utilizes a concentrated, nonaqueous, sterically stabilized ceramic powder and/or colloidal suspension which is injected into a non-porous mold. The suspension is then flocculated by destabilizing the suspension by lowering the temperature. Flocculation is both rapid and reversible. Cooling to -20°C produces a green body with sufficient strength for removal from the mold. The solvent is removed from the green body by evaporation. The dried green body is subsequently sintered to form a dense ceramic monolith. This is the first ceramic forming method based upon the manipulation of a sterically-stabilized suspension. To demonstrate IFM, the process of grafting polyethylene glycol (PEG), with molecular weights from 600 to 8000, to alumina powders was investigated. The maximum grafted amounts were achieved by the technique of dispersing the alumina powders in molten polymer at 195°C. The ungrafted PEG was then removed by repeated centrifuging and redispersion in fresh distilled water. The rheological behavior of suspensions of the PEG-grafted powders in water, 2-propanol and 2-butanol were characterized. All of the aqueous suspensions were shear thinning. The PEG 4600-grafted alumina powder aqueous suspensions were the most fluid. Sample rods and bars were molded from 52 vol% PEG-grafted alumina suspensions in 2-butanol. The best results were obtained with a preheated aluminum mold lubricated with a fluorinated oil mold-release. The samples were dried, sintered, and their microstructure and density were compared with sintered samples dry pressed from the same alumina powder

  17. Application of physiologically based pharmacokinetic modeling in predicting drug–drug interactions for sarpogrelate hydrochloride in humans

    Directory of Open Access Journals (Sweden)

    Min JS

    2016-09-01

    Full Text Available Jee Sun Min,1 Doyun Kim,1 Jung Bae Park,1 Hyunjin Heo,1 Soo Hyeon Bae,2 Jae Hong Seo,1 Euichaul Oh,1 Soo Kyung Bae1 1Integrated Research Institute of Pharmaceutical Sciences, College of Pharmacy, The Catholic University of Korea, Bucheon, 2Department of Pharmacology, College of Medicine, The Catholic University of Korea, Seocho-gu, Seoul, South Korea Background: Evaluating the potential risk of metabolic drug–drug interactions (DDIs is clinically important. Objective: To develop a physiologically based pharmacokinetic (PBPK model for sarpogrelate hydrochloride and its active metabolite, (R,S-1-{2-[2-(3-methoxyphenylethyl]-phenoxy}-3-(dimethylamino-2-propanol (M-1, in order to predict DDIs between sarpogrelate and the clinically relevant cytochrome P450 (CYP 2D6 substrates, metoprolol, desipramine, dextromethorphan, imipramine, and tolterodine. Methods: The PBPK model was developed, incorporating the physicochemical and pharmacokinetic properties of sarpogrelate hydrochloride, and M-1 based on the findings from in vitro and in vivo studies. Subsequently, the model was verified by comparing the predicted concentration-time profiles and pharmacokinetic parameters of sarpogrelate and M-1 to the observed clinical data. Finally, the verified model was used to simulate clinical DDIs between sarpogrelate hydrochloride and sensitive CYP2D6 substrates. The predictive performance of the model was assessed by comparing predicted results to observed data after coadministering sarpogrelate hydrochloride and metoprolol. Results: The developed PBPK model accurately predicted sarpogrelate and M-1 plasma concentration profiles after single or multiple doses of sarpogrelate hydrochloride. The simulated ratios of area under the curve and maximum plasma concentration of metoprolol in the presence of sarpogrelate hydrochloride to baseline were in good agreement with the observed ratios. The predicted fold-increases in the area under the curve ratios of metoprolol

  18. Comparison of direct infusion and on-line liquid chromatography/electrospray ionization mass spectrometry for the analysis of nucleic acids.

    Science.gov (United States)

    Huber, C G; Krajete, A

    2000-07-01

    The applicability of ion-pair reversed-phase high-performance liquid chromatography/electrospray ionization mass spectrometry (IP-RP-HPLC/ESI-MS) and direct infusion/ESI-MS to the characterization of nucleic acid mixtures was evaluated by the analysis of the reaction products obtained from solid-phase synthesis of a 39-mer oligonucleotide. IP-RP-HPLC/ESI-MS was performed using 200 microm i.d. capillary columns packed with octadecylated, micropellicular poly(styrene-divinylbenzene) particles and applying gradients of acetonitrile in 50 mM triethylammonium bicarbonate (TEAB). Three different solvent systems were utilized for direct infusion/ESI-MS with removal of metal cations by on-line cation exchange: (1) 10 mM triethylamine (TEA) in 50% aqueous acetonitrile, (2) 2.2 mM TEA, 400 mM hexafluoro-2-propanol (HFIP) in 20% aqueous methanol and (3) 50 mM TEAB in 10% aqueous acetonitrile. Owing to its separation capability, the highest selectivity and specificity were achieved with IP-RP-HPLC/ESI-MS, which, apart form the 39-mer target sequence, allowed the identification of two isobutyryl-protected target sequences and a 10-mer and 20-mer failure sequence. Direct infusion/ESI-MS with TEA-acetonitrile or TEA-HFIP-methanol as solvent revealed signals for the 39-mer in the m/z range 700-1600. The presence of derivatives containing one, two, three and four isobutyryl groups indicated that the hydrolysis of the protecting groups after solid-phase synthesis was not complete. Failure sequences could not be identified by direct infusion/ESI-MS under conditions favoring multiple charging of the analytes owing to the high chemical background and coincidental overlapping of m/z signals. However, efficient charge state reduction upon addition of carbonic acid to the electrosprayed solvent shifted the signals of the 39-mer and derivatives to m/z values >2400 and allowed the detection of seven different failure sequences, ranging from the 8-mer to the 23-mer, in the mixture.

  19. From Homogeneous to Heterogenized Solar Fuels Assemblies: Observation of Electron Transfer Events in Systems Containing Dye-Sensitized Semiconductors and Molecular Catalysts

    Science.gov (United States)

    Kamire, Rebecca Joy

    The conversion of solar energy into chemical energy by simultaneously oxidizing water and reducing protons to hydrogen could provide a much-needed fuel source within a more sustainable energy economy. Dye-sensitized photoelectrochemical cells (DSPECs) are capable of forming fuels using sunlight if photoexcited chromophores transfer charges to semiconductor electrodes and catalysts, and catalysis occurs, at rates exceeding those of charge recombination. The rational design of efficient DSPECs will require an understanding of the catalytic mechanisms and rate-limiting steps of the oxidative and reductive reactions. Here, we focus on how molecular and electrode design can be used to favor the desired charge transfer events from photoexcited perylene-3,4-dicarboximide (PMI) chromophores into semiconductor films and to molecular catalysts. Previous efforts with related chromophores have focused on charge transfer between dyes and catalysts in homogeneous covalent systems without the presence of a supporting electrode. In this work, femtosecond to millisecond transient absorption spectroscopies are utilized to identify a PMI derivative capable of injecting electrons into nanostructured semiconductor films with favorable rates and yields. The identified derivative is further used to oxidize covalently attached homogeneous water oxidation catalyst (WOC) precursor Cp*Ir III(ppy)Cl, where ppy = 2-phenylpyridine, on TiO2 and then incorporated into several photoelectrodes for photodriven water oxidation and hydrogen production. Atomic layer deposition of Al2O3 following chromophore adsorption is employed to improve the chemical stability of the chromophores and to prevent rapid electron-hole recombination. The TiO2-based photoanodes contain a coadsorbed WOC [(Ir IV(pyalc)(H2O)R)2(micro-O)] +2, where pyalc = 2-(2'pyridyl)-2-propanolate, or its mononuclear precursor functionalized with a siloxane binding group. NiO-based photocathodes include molecular cobaloxime- or [Ni(P2N2) 2

  20. Cleaning Efficiencies of Three Cleaning Agents on Four Different Surfaces after Contamination by Gemcitabine and 5-fluorouracile.

    Science.gov (United States)

    Böhlandt, Antje; Groeneveld, Svenja; Fischer, Elke; Schierl, Rudolf

    2015-01-01

    Occupational exposure to antineoplastic drugs has been documented for decades showing widespread contamination in preparation and administration areas. Apart from preventive measures, efficient cleaning of surfaces is indispensable to minimize the exposure risk. The aim of this study was to evaluate the efficiency of three cleaning agents after intentional contamination by gemcitabine (GEM) and 5-fluorouracile (5-FU) on four different surface types usually installed in healthcare settings. Glass, stainless steel, polyvinylchloride (PVC), and laminated wood plates were contaminated with 20 ng/μl GEM and 2 ng/μl 5-FU solutions. Wipe samples were analyzed for drug residues after cleaning with a) distilled water, b) aqueous solution containing sodium dodecyl sulfate (10 mM) and 2-propanol (SDS-2P), and c) Incides N (pre-soaked) alcoholic wipes. Quantification was performed by high-performance liquid chromatography (HPLC) for GEM and gas chromato-graphy-tandem mass spectrometry (GCMS/MS) for 5-FU. Recovery was determined and cleaning efficiency was calculated for each scenario. Mean recoveries were 77-89% for GEM and 24-77% for 5-FU and calculated cleaning efficiencies ranged between 95 and 100% and 89 and 100%, respectively. Residual drug amounts were detected in the range nd (not detected) - 84 ng GEM/sample and nd - 6.6 ng 5-FU/sample depending on surface type and cleaning agent. Distilled water and SDS-2P had better decontamination outcomes than Incides N wipes on nearly all surface types, especially for GEM. Regarding 5-FU, the overall cleaning efficiency was lower with highest residues on laminated wood surfaces. The tested cleaning procedures are shown to clean glass, stainless steel, PVC, and laminated wood with an efficiency of 89-100% after contamination with GEM and 5-FU. Nevertheless, drug residues could be verified by wipe samples. Pure distilled water and SDS in an alcoholic-aqueous solution expressed an efficient cleaning performance, especially with