Induced spawning of African cat fish Clarias lazera (C. and V.) using acetone dried carp pituitary extract, deoxy-corticosterone acetate and human chorionic gonadotropin

A study was conducted to determine the efficacy of carp pituitary extract, deoxycorticosterone acetate, and human chorionic gonadotropin in inducing spawning in Clarias lazera . Results indicate deoxycorticosterone acetate to be more potent than pituitary extract, although the difference is not significant

Miscibility and Hydrogen Bonding in Blends of Poly(4-vinylphenol)/Poly(vinyl methyl ketone)

The miscibility and phase behavior of poly(4-vinylphenol) (PVPh) with poly(vinyl methyl ketone) (PVMK) was investigated by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). It was shown that all blends of PVPh/PVMK are totally miscible. A DSC study showed the apparition of a single glass transition (T-g) over their entire composition range. When the amount of PVPh exceeds 50% in blends, the obtained T(g)s are found to be significantly higher than those observed for each individual component of the mixture, indicating that these blends are capable of forming interpolymer complexes. FTIR analysis revealed the existence of preferential specific interactions via hydrogen bonding between the hydroxyl and carbonyl groups, which intensified when the amount of PVPh was increased in blends. Furthermore, the quantitative FTIR study carried out for PVPh/PVMK blends was also performed for the vinylphenol (VPh) and vinyl methyl ketone (VMK) functional groups. These results were also established by scanning electron microscopy study (SEM).

Modificação química do poli(cloreto de vinila) com nucleófilos nitrogenados assistida por micro-ondas

Nesse trabalho foram realizadas reações de substituição nucleofílica (SN2), utilizando aquecimento térmico convencional e por irradiação de micro-ondas (MO), de alguns átomos cloro em amostras comerciais de poli(cloreto de vinila) (PVC), por grupos nitrila e também por grupos azida. Os grupos nitrila e azida foram substituidos na matriz em diferentes teores (10% e 20%). As reações do PVC com azida foram eficazes, apresentado percentuais de derivatização muito próximos dos valores desejados. Já no estudo com a nitrila não foi obtido o resultado esperado. Os copolímeros PVC azido substituídos foram modificados com propargilato de etila, sob catálise de iodeto de cuproso (CuI), para a obtenção de heterocíclicos do tipo triazólicos. Todos os copolímeros obtidos foram caracterizados por espectroscopia na região do infravermelho (FTIR) e os teores de nitrogênio incorporado foram determinados por análise elementar (AE). Através da análise dos dados obtidos, foi comprovado que a utilização da irradiação micro-ondas, quando comparada ao aquecimento convencional, é um processo mais seletivo e diminui, significativamente, os tempos de reação

Effect of dietary supplementation of tocoferol acetate alone and with varying combinations on growth, survival and fatty acids profile of Macrobrachium rosenbergii larvae through Moina micrura enrichment

A study was carried out to determine the effect of tocopherol acetate along with cod liver oil astaxanthin enriched Moina micrura (MC- control, Ml- tocopherol acetate enriched, M2-tocopherol acetate combined with cod liver oil (CLO) enriched and M3- tocopherol acetate combined with astaxanthin enriched) on growth, survival and fatty acid composition of M. rosenbergii (de Man) larvae (TC- unenriched Moina fed larvae, Tl- tocopherol acetate enriched Moina fed larvae, T2- tocopherol acetate + CLO enriched Moina fed larvae to T3 – tocopherol acetate+ astaxanthin enriched Moina fed larvae). Growth was expressed as the time taken in to the settlement of 95% post larvae. Maximum growth i.e., the lowest time taken to the 95% PL settlement (40 days) and the maximum survival percentage (61%) was observed in both T2 and T3 treatments fed with M2 and M3 Moina respectively. Minimum growth and survival was observed in unenriched Moina fed larvae (TC). In larval treatments T2, (larvae fed with (M2) vitamin E + CLO enriched Moina), showed a higher percentage of EPA, DHA and higher HUFA level than other treatments.

Application of combined effect of sodium acetate and nisin on reduction of contamination by Listeria monocytogenes in vacuum packaged grass carp (Ctenopharyngodon idella) fillets kept at 4°C

In this study microbiological , chemical quality and fatty acid composition of grass carp (Ctenopharyngodon idella) fillets treated by dipping in sodium acetate (%1 and %3), nisin (% 0.1 and % 0.2) and combination of sodium acetate and nisin was evaluated during 16 days of refrigerated of 4°C Antilisterial effect of nisin was enhanced with the increased concentration of sodium acetate. At day 12 post storage, Listeria monocytogenese count was higher in the control group than the recommended value, however in sodium acetate and nisin treated samples, the count was lower (5.17-5.91 log cfu/g). With increasing the concentrations of sodium acetate, mesophilic counts were lower. Regarding nisin, better results was obtained by applying %0.1 nisin. Greater inhibition of mesophile bacteria was observed when combination treatment was used. The number of lactobacillus was lower when higher concentrations of sodium acetate and nisin were used. Total Volatile Nitrogen values at the end of the experiment were lower in the samples treated with both nisin and sodium acetate and the better results were obtained in combination treatments. Peroxide (PV) at the end of the experiment was 1.9 meq/kg in control, and the lowest values were observed for the treatments 3(%0 sodium acetate +% 0.2 nisin) and 9(%3 sodium acetate +% 0.2 nisin) between 1.08 and 1.62 meq/kg without significant difference. Thiobarbituric acid (TBA) levels at the end of experiment have been shown to be 0.46 mg malonaldehyde per kg in the control. On the other hand treatments 9 had the TBA values of 0.19 mg malonaldehyde per kg which was significantly lower than that of control. Polyunsaturated fatty acids increased by increasing the sodium acetate doses and instead saturated fatty acids and n-6/n-3 ratio decreased. The ratio of UFA/SFA and also C22:6/C16:0 increased when a higher concentration of sodium acetate has been used. The best result obtained by using 3% of sodium acetate but no such relation with nisin was observed.

Cellulose acetate polymer film modified microstructured polymer optical fiber towards a nitrite optical probe

A novel microstructured polymer optical fiber (MPOF) probe for nitrites (NO(2)(-)) detection was made by forming rhodamine 6G (Rh 6G)-doped cellulose acetate (CA) on the side wall of array holes in a MPOF It was found that the MPOF probe only have a response to nitrites in a certain concentration of sulfuric acid solution The calibration graph of fluorescence intensity versus nitrites concentration was linear in the range of 2.0 x 10(-4) g/ml-5.0 x 10(-3) g/ml. The method possesses case of chemical modification, low cost design, and potential for direct integration with existing instrumentation, and has been applied to the determination of nitrites in real samples with satisfactory results. (C) 2010 Elsevier B.V. All rights reserved

Preparation and performance of cellulose acetate/polyethyleneimine blend microfiltration membranes and their applications

A modified microfiltration membrane has been prepared by blending a matrix polymer with a functional polymer. Cellulose acetate (CA) was blended with polyethyleneimine (PEI), which was then crosslinked by polyisocyanate, in a mixture of solvents. In the membrane, PEI can supply coupling sites for ligands in affinity separation or be used as ligands for metal chelating, removal of endotoxin or ion exchange. The effects of the time of phase inversion induced by water vapor, blended amount of PEI and amount of crosslinking agent on membrane performance were investigated. The prepared blend membranes have specific surface area of 12.04-24.11 m(2)/g and pure water flux (PWF) of 10-50 ml/cm(2) min with porosity of 63-75%. The membranes, made of 0.15 50 wt.% PEI/CA ratio and 0.5 crosslinking agent/PEI ratio, were applied to adsorbing Cu2+ and bovine serum albumin (BSA) individually. The maximum adsorption capacity of Cu2+ ion on the blend membrane is 7.42 mg/g dry membrane. The maximum adsorption capacities of BSA on the membranes with and without chelating Cu2+ ion are 86.6 and 43.8 mg/g dry membrane, respectively. (C) 2004 Elsevier B.V. All rights reserved.

Determination of lead using a poly(vinyl chloride)-based crown ether membrane

A poly(vinyl chloride)(PVC)-based membrane of 15-crown-5 exhibits a good response for lead(II) ions over a wide concentration range. The response time of the sensor is 30 s and the membrane can be used for more than four months without observing any divergence. The selectivity of the sensor is comparable with those reported for other such electrodes. It was possible to determine lead in polluted waters using this electrode assembly.

(Z)-2-(2-chloro-3,3,3-trifluoroprop-1enyl)-6-methoxyphenyl acetate

The crystal structure of the title compound, C12H10ClF3O3, was determined in order to establish the configuration of the C double bond. The compound was found to be the Z isomer. The crystal structure is dominated by Cl center dot center dot center dot O halogen bonds [Cl center dot center dot center dot O = 3.111 (3) angstrom], as well as C-H center dot center dot center dot O and C-H center dot center dot center dot F hydrogen-bonding interactions, that connect neighboring molecules into a three-dimensional supramolecular network.

Preparation and Characterization of Interpenetration Polymer Network Films Based on Poly(vinyl alcohol) and Poly(acrylic acid) for Drug Delivery

A series of full interpenetrating polymer network (full-IPN) films of poly(acrylic acid) (PAA)/poly (vinyl alcohol) (PVA) were prepared by radical solution polymerization and sequential IPN technology. Attenuated total reflectance-Fourier transform infrared spectroscopy, swelling properties, mechanical properties, morphology, and glass transition temperature of the films were investigated. FTIR spectra analysis showed that new interaction hydrogen bonds between PVA and PAA were formed. Swelling property of the films in distilled water and different pH buffer solution was studied. Swelling ratio increased with increasing PAA content of IPN films in all media, and swelling ratio decreased with increasing PVA crosslink degree. Tensile strength and elongation at break related not only to the constitution of IPNs but also to the swelling ratio of IPNs.

Separation of ethyl acetate-ethanol azeotropic mixture using hydrophilic ionic liquids

The separation of ethyl acetate and ethanol (EtOH) is important but difficult due to their close boiling points and formation of an azeotropic mixture. The separation of the azeotropic mixture of ethyl acetate and EtOH using the hydrophilic ionic liquids (ILs) 1-alkyl-3-methylimidazolium chloride (alkyl = butyl, hexyl, and octyl) ([C(n)mim]Cl, n = 4, 6, 8) and 1-allyl-3-methylimidazolium chloride and bromide ([Amim]Cl and [Amim]Br) has been investigated. Triangle phase diagrams of five ILs with ethyl acetate and EtOH were constructed, and the biphasic regions were found as follows: [Amim]Cl > [Amim]Br > [C(4)mim]Cl > [C(6)mim]Cl > [C(8)mim]Cl. The mechanisms of the ILs including cation, anion, and polarity effect were discussed.