993 resultados para Solvent orange 7
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Shellac is the purified product of the natural polymer Lac. Shellac types, from different origins and with different ages, all purified by the solvent extraction process were compared in this study. Their physicochemical properties acid value, glass transition temperatures, color numbers and molecular sizes were determined. Metoprolol tartrate pellets were coated by air suspension coating with these different grades of shellac. Two coating levels 20% w/w and 25% w/w were applied and then subjected to in vitro dissolution testing. Enteric resistance was achieved for all tested brands for the two coating levels. At pH 6.8, 7.2 and 7.4, significant variations were obvious between the brands. rnMoreover the molecular size of shellac has a pronounced effect in that shellac types with larger molecular size show a higher and faster release than others, while the one with the smaller molecular size show the opposite effect on the release of metoprolol.rnIn this study commercially available ready for use aqueous shellac solutions (SSB AQUAGOLD), which are based on shellac SSB 57 (Dewaxed Orange Shellac, Bysakhi-Ber type refined in a solvent extraction process), with different manufacturing dates were used. rnTo improve the enteric coating properties of films from aqueous shellac solutions, different aqueous polymeric solutions of hydroxypropyl methylcellulose (HPMC), hydroxypropyl cellulose (HPC), carboyxmethyl cellulose (CMC), gum arabic and polysaccharides (Pullulan®) were used. These water soluble polymers will act as pore formers to enhance drug release from pellets coated with the combination of shellac and these polymers. The influence of these polymers on the gloss of the shellac films, mechanical properties of the films and drug release from metoprolol tartrate pellets were studied.rnThe potential of ethanol to alter the rate of drug release from shellac coated pellets was assessed by using a modified in vitro dose dumping in alcohol (DDA) method and the test concluded that shellac coated dosage forms can be co-administered with alcohol beverages containing ≤ 5% with no effect of alcohol on the shellac coat.rnPellets coated with shellac sodium salts, showed higher release rates than pellets coated with shellac as ammonium salt forms. rn
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Il seguente elaborato analizza l'importanza di un'adeguata rappresentazione di personaggi appartenenti allo spettro LGBT all'interno di programmi televisivi nordamericani, in particolare Orange Is The New Black e Orphan Black. Lo scopo della tesi è quello di provare l'importanza della rappresentazione nella costruzione dell'identità personale di ognuno, e nella lotta contro le discriminazioni di genere e orientamento sessuale. Le tesi si apre con un excursus teorico sul termine e il concetto di rappresentazione, soprattutto relativo all'ambito della televisione. Successivamente, vengono analizzati i vari tipi di rappresentazione all'interno nei due programmi televisivi presi in esame. La ricerca si conclude con una valutazione degli effetti e delle reazioni del pubblico a entrambi i telefilm e, infine, con alcune considerazioni personali.
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Ocean acidification is predicted to affect marine ecosystems in many ways, including modification of fish behaviour. Previous studies have identified effects of CO2-enriched conditions on the sensory behaviour of fishes, including the loss of natural responses to odours resulting in ecologically deleterious decisions. Many fishes also rely on hearing for orientation, habitat selection, predator avoidance and communication. We used an auditory choice chamber to study the influence of CO2-enriched conditions on directional responses of juvenile clownfish (Amphiprion percula) to daytime reef noise. Rearing and test conditions were based on Intergovernmental Panel on Climate Change predictions for the twenty-first century: current-day ambient, 600, 700 and 900 µatm pCO2. Juveniles from ambient CO2-conditions significantly avoided the reef noise, as expected, but this behaviour was absent in juveniles from CO2-enriched conditions. This study provides, to our knowledge, the first evidence that ocean acidification affects the auditory response of fishes, with potentially detrimental impacts on early survival.
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Sediments from near the basement of a number of Deep Sea Drilling Project (DSDP) sites, from the Bauer Deep, and from the East Pacific Rise have unusually high transition metal-to-aluminum ratios. Similarities in the chemical, isotopic, and mineralogical compositions of these deposits point to a common origin. All the sediments studied have rare-earth-element (REE) patterns strongly resembling the pattern of sea water, implying either that the REE's were coprecipitated with ferromanganese hydroxyoxides (hydroxyoxides denote a mixture of unspecified hydrated oxides and hydroxides), or that they are incorporated in small concentrations of phosphatic fish debris found in all samples. Oxygen isotopic data indicate that the metalliferous sediments are in isotopic equilibrium with sea water and are composed of varying mixtures of two end-member phases with different oxygen isotopic compositions: an iron-manganese hydroxyoxide and an iron-rich montmorillonite. A low-temperature origin for the sediments is supported by mineralogical analyses by x-ray diffraction which show that goethite, iron-rich montmorillonite, and various manganese hydroxyoxides are the dominant phases present. Sr87/Sr86 ratios for the DSDP sediments are indistinguishable from the Sr87/Sr86 ratio in modern sea water. Since these sediments were formed 30 to 90 m.y. ago, when sea water had a lower Sr87/Sr86 value, the strontium in the poorly crystalline hydroxyoxides must be exchanging with interstitial water in open contact with sea water. In contrast, uranium isotopic data indicate that the metalliferous sediments have formed a closed system for this element. The sulfur isotopic compositions suggest that sea-water sulfur dominates these sediments with little or no contribution of magmatic or bacteriologically reduced sulfur. In contrast, ratios of lead isotopes in the metalliferous deposits resemble values for oceanic tholeiite basalt, but are quite different from ratios found in authigenic marine manganese nodules. Thus, lead in the metalliferous sediments appears to be of magmatic origin. The combined mineralogical, isotopic, and chemical data for these sediments suggest that they formed from hydrothermal solutions generated by the interaction of sea water with newly formed basalt crust at mid-ocean ridges. The crystallization of solid phases took place at low temperatures and was strongly influenced by sea water, which was the source for some of the elements found in the sediments.
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An experiment was conducted to investigate the effects of increasing the level of two sources of fibrous by-products, orange pulp (OP) and carob meal (CM), in iso-NDF growing-finishing pig diets on nutrient balance, slurry composition and potential ammonia (NH3) and methane (CH4) emissions. Thirty pigs (85.4 ± 12.3 kg) were fed five iso-nutritive diets: a commercial control wheat/barley (C) and four experimental diets including two sources of fibrous by-products (OP and CM) and two dietary levels (75 and 150 g/kg) in a 2 × 2 factorial arrangement. After a 14-day adaptation period, faeces and urine were collected separately for 7 days to measure nutrient digestibility and the excretory patterns of N from pigs (6 replicates per diet) housed individually in metabolic pens. For each animal, the derived NH3 and CH4 emissions were measured in samples of slurry over an 11- and 100-day storage periods, respectively. Source and level of the fibrous by-products affected digestion efficiency in a different way as the coefficients of total tract apparent digestibility (CTTAD) for dry matter (DM), organic matter (OM), fibre fractions and gross energy increased with OP but decreased with CM (P < 0.05). Crude protein CTTAD decreased with the inclusion of both sources of fibre, being lower at the highest dietary level. Faecal concentration of fibre fractions increased (P < 0.05) with the level of inclusion of CM but decreased with that of OP (P < 0.01). High dietary level for both sources of fibre increased (P < 0.02) CP faecal content but urine N content decreased (from 205 to 168 g/kg DM, P < 0.05) in all the fibre-supplemented compared to C diet. Additionally, the proportions of undigested dietary, water soluble, and bacterial and endogenous debris of faecal N excretion were not affected by treatments. The initial slurry characteristics did not differ among different fibre sources and dietary levels, except pH, which decreased at the highest by-product inclusion levels. Ammonia emission per kg of slurry was lower in all the fibre-supplemented diets than in C diet (from 2.44 to 1.81 g, P < 0.05). Additionally, slurries from the highest dietary level of by-products tended (P < 0.06) to emit less NH3 per kg of initial total Kjeldahl N and showed a lower B0, independently of the fibre source. Thus, the fibre sources and their dietary levels affected pig nutrient digestion and composition of urine and faeces, showing potential to decrease NH3 and CH4 emissions at high levels of inclusion, independently of type of fibre.
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The aim of this study was to establish the relationships between faecal fat concentration and gaseous emissions from pig slurry. Five diets were designed to meet essential nutrient requirements: a control and four experimental feeds including two levels (35 or 70 g/kg) of calcium soap fatty acids distillate (CSP) and 0 or 200 g/kg of orange pulp (OP) combined in a 2 × 2 factorial structure. Thirty growing pigs (six per treatment) were used to measure dry matter (DM) and N balance, coefficients of total tract apparent digestibility (CTTAD) of nutrients, faecal and urine composition and potential emissions of ammonia (NH3) and methane (CH4). Increasing dietary CSP level decreased DM, ether extract (EE) and crude protein (CP) CTTAD (by 4.0, 11.1 and 3.5%, respectively, P < 0.05), but did not influence those of fibrous constituents. It also led to a decrease (from 475 to 412 g/kg DM, P < 0.001) of faecal concentration of neutral detergent fibre (aNDFom) and to an increment (from 138 to 204 g/kg, P < 0.001) of EE in faecal DM that was related to greater CH4 emissions, both per gram of organic matter (P = 0.021) or on a daily basis (P < 0.001). Level of CSP did not affect N content in faeces or urine, but increased daily DM (P < 0.001), and N (P = 0.031) faecal excretion with no effect on urine N excretion. This resulted in lesser (P = 0.036) NH3 potential emission per kg of slurry. Addition of OP decreased CTTAD of EE (by 7.9%, P = 0.044), but increased (P < 0.05) that of all the fibrous fractions. As a consequence, faecal EE content increased (from 165 to 177 g/kg DM; P = 0.012), and aNDFom decreased greatly (from 483 to 404 g/kg DM, P < 0.001), which in all resulted in a lack of effect of OP on CH4 potential emission. Inclusion of OP in the diet also led to a significant decrease of CP CTTAD (by 6.85%, P < 0.001), and to an increase of faecal CP concentration (from 174 to 226 g/kg DM, P < 0.001), with no significant influence on urine N content. These effects resulted in higher N faecal losses, especially those of the undigested dietary origin, without significant effects on potential NH3 emission. No significant interactions between CSP and OP supplementation were observed for the gaseous emissions measured.
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BINAM-prolinamides are very efficient catalyst for the synthesis of non-protected and N-benzyl isatin derivatives by using an aldol reaction between ketones and isatins under solvent-free conditions. The results in terms of diastereo- and enantioselectivities are good, up to 99% de and 97% ee, and higher to those previously reported in the literature under similar reaction conditions. A high variation of the results is observed depending on the structure of the isatin and the ketone used in the process. While 90% of ee and 97% ee, respectively, is obtained by using (Ra)-BINAM-l-(bis)prolinamide as catalyst in the addition of cyclohexanone and α-methoxyacetone to free isatin, 90% ee is achieved for the reaction between N-benzyl isatin and acetone using N-tosyl BINAM-l-prolinamide as catalyst. This reaction is also carried out using a silica BINAM-l-prolinamide supported catalyst under solvent-free conditions, which can be reused up to five times giving similar results.
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2. sér. has imprint: Utrecht : Kemink et fils, 1857-1861; 3.-5. seÌr. have imprint: Leyde : A.W. Sijthoff, 1907-1915.
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Lipidome profile of fluids and tissues is a growing field as the role of lipids as signaling molecules is increasingly understood, relying on an effective and representative extraction of the lipids present. A number of solvent systems suitable for lipid extraction are commonly in use, though no comprehensive investigation of their effectiveness across multiple lipid classes has been carried out. To address this, human LDL from normolipidemic volunteers was used to evaluate five different solvent extraction protocols [Folch, Bligh and Dyer, acidified Bligh and Dyer, methanol (MeOH)-tert-butyl methyl ether (TBME), and hexane-isopropanol] and the extracted lipids were analyzed by LC-MS in a high-resolution instrument equipped with polarity switching. Overall, more than 350 different lipid species from 19 lipid subclasses were identified. Solvent composition had a small effect on the extraction of predominant lipid classes (triacylglycerides, cholesterol esters, and phosphatidylcholines). In contrast, extraction of less abundant lipids (phosphatidylinositols, lyso-lipids, ceramides, and cholesterol sulfates) was greatly influenced by the solvent system used. Overall, the Folch method was most effective for the extraction of a broad range of lipid classes in LDL, although the hexane-isopropanol method was best for apolar lipids and the MeOH-TBME method was suitable for lactosyl ceramides. Copyright © 2013 by the American Society for Biochemistry and Molecular Biology, Inc.
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The Li-O2 battery may theoretically possess practical gravimetric energy densities several times greater than the current state-of-the-art Li-ion batteries.1 This magnitude of development is a requisite for true realization of electric vehicles capable of competing with the traditional combustion engine. However, significant challenges must be addressed before practical application may be considered. These include low efficiencies, low rate capabilities and the parasitic decomposition reactions of electrolyte/electrode materials resulting in very poor rechargeability.2-4 Ionic liquids, ILs, typically display several properties, extremely low vapor pressure and high electrochemical and thermal stability, which make them particularly interesting for Li-O2 battery electrolytes. However, the typically sluggish transport properties generally inhibit rate performance and cells suffer similar inefficiencies during cycling.5,6
In addition to the design of new ILs with tailored properties, formulating blended electrolytes using molecular solvents with ILs has been considered to improve their performance.7,8 In this work, we will discuss the physical properties vs. the electrochemical performance of a range of formulated electrolytes based on tetraglyme, a benchmark Li-O2 battery electrolyte solvent, and several ILs. The selected ILs are based on the bis{(trifluoromethyl)sulfonyl}imide anion and alkyl/ether functionalized cyclic alkylammonium cations, which exhibit very good stability and moderate viscosity.9 O2 electrochemistry will be investigated in these media using macro and microdisk voltammetry and O2 solubility/diffusivity is quantified as a function of the electrolyte formulation. Furthermore, galvanostatic cycling of selected electrolytes in Li-O2 cells will be discussed to probe their practical electrochemical performance. Finally, the physical characterization of the blended electrolytes will be reported in parallel to further determine structure (or formulation) vs. property relationships and to, therefore, assess the importance of certain electrolyte properties (viscosity, O2supply capability, donor number) on their performance.
This work was funded by the EPSRC (EP/L505262/1) and Innovate UK for the Practical Lithium-Air Batteries project (project number: 101577).
1. P. G. Bruce, S. A. Freunberger, L. J. Hardwick and J.-M. Tarascon, Nat. Mater., 11, 19 (2012).
2. S. A. Freunberger, Y. Chen, N. E. Drewett, L. J. Hardwick, F. Barde and P. G. Bruce, Angew. Chem., Int. Ed., 50, 8609 (2011).
3. B. D. McCloskey, A. Speidel, R. Scheffler, D. C. Miller, V. Viswanathan, J. S. Hummelshøj, J. K. Nørskov and A. C. Luntz, J. Phys. Chem. Lett., 3, 997 (2012).
4. D. G. Kwabi, T. P. Batcho, C. V. Amanchukwu, N. Ortiz-Vitoriano, P. Hammond, C. V. Thompson and Y. Shao-Horn, J. Phys. Chem. Lett., 5, 2850 (2014).
5. Z. H. Cui, W. G. Fan and X. X. Guo, J. Power Sources, 235, 251 (2013).
6. F. Soavi, S. Monaco and M. Mastragostino, J. Power Sources, 224, 115 (2013).
7. L. Cecchetto, M. Salomon, B. Scrosati and F. Croce, J. Power Sources, 213, 233 (2012).
8. A. Khan and C. Zhao, Electrochem. Commun., 49, 1 (2014).
9. Z. J. Chen, T. Xue and J.-M. Lee, RSC Adv., 2, 10564 (2012).
Resumo:
Neste trabalho são apresentadas e discutidas as estruturas cristalinas e moleculares do ligante (1), isatina-3-(toluilsulfono-hidrazona), dos complexos [bis(2-acetilpiridina-N4 - benziltiossemicarbazona-N,N,S)Cd(II)], (1), [bis (isatina-3-N4 -benziltiossemicarbazonaN,S)Hg(II)].Etanol, (2) e [bis (isatina-3-N4 -benziltiossemicarbazona-N,S,O)Zn(II)].DMF, (3). Cristais amarelos vítreos do ligante (1) foram obtidos a partir da evaporação lenta de etanol do ensaio de cristalização. Seus dados cristalográficos indicam que duas moléculas interagem através de ligações de hidrogênio do tipo N1-H···O1, formando unidades dímeras. A reação entre 2-acetilpiridina-N4 -benziltiossemicarbazona e Cd(CH3COO)2.2H2O, em presença de etanol, KOH, e após evaporação lenta da mistura de acetona e DMF(2:1), resultou em cristais amarelos do complexo (1). As interações do tipo C(10)-H(10)···S(1)···H(1)-N(4), e N(8)- H(29)⋅⋅⋅S(2) permitem a dimerização do complexo, e a formação de uma cadeia unidimensional. Os cristais laranja do complexo (2) foram obtidos da reação entre o ligante isatina-3-N4 -benziltiossemicarbazona e Hg(NO3)2.H2O, na presença de metanol, KOH, e após evaporação lenta de uma mistura de tolueno e acetona (2:1). As moléculas do complexo (2) estão associadas por ligações de hidrogênio do tipo N(63)-H(4)···O(21), essas interações centrossimétricas conduzem a formação de dímeros. A reação entre o ligante isatina-3-N4 - benziltiossemicarbazona e Zn(CH3COO)2.2H2O, em presença de etanol e KOH resultou em cristais de coloração laranja do complexo (3). A estrutura do complexo apresenta múltiplas ligações de hidrogênio, com formação de dímeros através das interações N1-H1···O1 e C3- H3···N(7). Os dímeros associam-se por interações N4-H4···O2 numa cadeia unidimensional ao longo da direção cristalográfica [100]. A polimerização bidimensional é observada 7 considerando-se as interações do tipo C20-H20···S1, N8-H8···S2 ao longo da direção cristalográfica [010], bem como das interações, N5-H5···O3DMF e C31-H31B···Car, que ocorrem através da molécula de solvente DMF.
Clustering of Protein Structures Using Hydrophobic Free Energy And Solvent Accessibility of Proteins