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L. S. Lussier C. Sandorfy H. OA L E-Thanh D. Vocelle 《Photochemistry and photobiology》1987,45(S1):801-808
Abstract— The Fourier-transform infrared spectra of chloroform-d solutions of conjugated imines CH3 CH=CHCH=NCH(CH3 )2 and CH3 CH2 CH=CHCH=CHCH=NCH(CH3 )2 and the related protonated species with HCl, HBr, HI, trichloro, dichloro, monobromo and monochloroacetic acids or propionic acid are presented. The effects of conjugation and protonation are examined. The results show that conjugation slightly increases the basicity of the Schiff bases. HCl, HBr and HI protonate the Schiff bases completely. The carboxylic acids protonate partially depending on their p K a , values. When the Schiff base contains two (or more) C=C bonds conjugated with C=N, the main C=C stretching band undergoes a strong intensification showing that sizeable dipole moment variations occur along the conjugated chain. 相似文献
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Rabaeh Khalid A. Hammoudeh Issra’ M. E. Moftah Belal Oglat Ammar A. Eyadeh Molham M. Aldweri Feras M. Abdel-Qader Ala’ J. Devic Slobodan 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(2):665-672
Journal of Radioanalytical and Nuclear Chemistry - A novel low toxic normoxic polymer gel dosimeter containing acrylic acid monomer is prepared and characterized for dosimetry in radiotherapy. Gel... 相似文献
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Moftah OA Grbavčić S Zuža M Luković N Bezbradica D Knežević-Jugović Z 《Applied biochemistry and biotechnology》2012,166(2):348-364
Olive oil cake is a by-product from the olive oil processing industry and can be used for the lipase and protease production
by Candida utilis in solid state fermentation. Different carbon and nitrogen sources were evaluated, and the results showed that the supplementation
of the substrate with maltose and starch as carbon sources and yeast extract as a nitrogen source significantly increased
the lipase production. The best results were obtained with maltose, whereas rather low lipase and protease activities were
found with glucose and oleic acid. Response surface methodology and a five-level–three-factor central composite rotatable
design were used to evaluate the effects of the initial moisture content, inoculum size and fermentation time on both lipase
and protease activity levels. A lipase activity value of ≈25 U g-1 and a protease activity value of 110 U g-1 were obtained under the optimized fermentation conditions. An alkaline treatment of the substrate appeared to be efficient,
leading to increases of 39% and 133% in the lipase and protease production, respectively. The results showed that the olive
cake could be a good source for enzyme production by solid state fermentation. 相似文献
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A simple, sensitive and accurate spectrophotometric method has been described for the assay of diphenhydramine hydrochloride (DPH) in raw material and in biological samples. The method is based on extraction of DPH into dichloromethane as ion-pair complexes with patent blue (PB), eriochrome black T (EBT), methyl orange (MO) and bromocresol purple (BCP) in acidic medium. The coloured species exhibited absorption maxima at 632, 514, 428 and 414 nm for PB, EBT, MO and BCP, with molar absorptivity values of 1.32 × 105, 2.36 × 104, 3.68 × 104 and 3.07 × 104 l mol?1 cm?1, respectively. The reaction conditions were optimized to obtain the maximum colour intensity. Beer’s law was obeyed with a good correlation coefficient (0.9982–0.9993) in the concentration ranges 0.5–3, 2.0–16, 2.0–10 and 1.0–10 μg ml?1 for PB, EBT, MO and BCP methods, respectively. The composition ratio of the ion-association complexes was found to be 1:1 in all cases as established by Job’s method. The conditional stability constant (Kf) and the free energy changes (ΔG°) were determined for all complexes formed. The proposed method was successfully applied for the determination of DPH in tablets and human urine with good accuracy and precision. Statistical comparison of the results with those obtained by the official method showed good agreement and indicated no significant difference in accuracy and precision. 相似文献
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