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981.
982.
Allergenic extracts were produced from Drechslera (Helminthosporium) monoceras biomass cultured by solid-state fermentation using wheat bran as the substrate. The main fermentation variables were selected by statistical design, and the optimized biomass yield (1.43 mg/[g of dry substrate · d]) was obtained at pH 9.5 and 45.8% moisture. The allergenic extracts were produced from crude extract by protein precipitation and polyphenol removal. Proteins in the range of 16–160 kDa were identified in the extracts. Their reactions in patients were characterized by in vivo cutaneous tests (positive in 40% of the atopic patients) and by dot-blotting assays.  相似文献   
983.
A novel fused isocoumarin skeleton has been synthesized through selective domino multicyclizations by mixing homothallic acid and 2,3-diphenylacryloyl chloride at 200℃ under catalyst and solvent free reaction conditions. Six fused rings with two stereogenic centers were assembled in a convenient onepot operation in good yield. The resulting hexacyclic fused isocoumarin skeleton and its stereochemistry was fully characterized and unambiguously confirmed by X-ray diffraction analysis.  相似文献   
984.
Shape memory polymer (SMP) foams have been developed for use in neurovascular occlusion applications. These materials are predominantly polyurethanes that are known for their biocompatibility and tunable properties. However, these polymers inherently lack X‐ray visibility, which is a significant challenge for their use as implantable materials. Herein, low density, highly porous shape memory polyurethane foams were developed with tungsten nanoparticles dispersed into the foam matrix, at increasing concentrations, to serve as a radiopaque agent. Utilizing X‐ray fluoroscopy sufficient visibility of the foams at small geometries was observed. Thermal characterization of the foams indicated altered thermal response and delayed foam actuation with increasing nanoparticle loading (because of restricted network mobility). Mechanical testing indicated decreased toughness and strength for higher loading because of disruption of the SMP matrix. Overall, filler addition imparted x‐ray visibility to the SMP foams and allowed for tuned control of the transition temperature and actuation kinetics for the material. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
985.
Novel heterocyclic phosphoramidates were synthesized by a nucleophilic substitution reaction of 2-substitutedbenzimidazoles and diphenyl chlorophosphate (ClPO3Ph2) in the presence of potassium hydroxide (KOH) under an argon atmosphere. The structures of the phosphoramidates were characterized by NMR, IR, melting point, and elemental analysis.  相似文献   
986.
This paper undertakes the investigation of ordered vector spaces by applying nonstandard analysis. We introduce and study two types of nonstandard hulls of ordered vector spaces. Norm-nonstandard hulls of ordered Banach spaces are also investigated.  相似文献   
987.
Anthocyanins are water‐soluble pigments that are liable for colors ranging from red to blue of most fruits, vegetables, and flowers. A novel and fast method was developed for the determination of five anthocyanins and free pelargonidin by high‐performance liquid chromatography coupled to photodiode array detection. A 10% formic acid and acetonitrile mixture was employed as mobile phase in the gradient elution mode. Mobile phase composition, column temperature, flow rate, injection volume, and column conditioning time were optimized by employing a stepwise strategy. Using a C18 core–shell column (100 × 4.6 mm, 2.7 μm), the separation of six analytes was accomplished in less than 9.5 min with a run‐to‐run analysis time of 19 min. The developed method was validated with respect to linearity (r > 0.9999), limit of detection, limit of quantification, intra‐/interday precision (<2%), accuracy (98.6–104.4%), and specificity. Afterwards, the method was applied to the determination of anthocyanins present in 15 different samples including fruits, fruit juices, and fruit wines.  相似文献   
988.
A new method for the selective extraction of p‐aminosalicylic acid from aqueous and urine samples has been developed using magnetic molecularly imprinted polymer nanoparticles before determination by high‐performance liquid chromatography. The Fe3O4 nanoparticles were first prepared through the chemical coprecipitation of Fe2+ and Fe3+ and then coated with a vinyl shell. Subsequently, a layer of molecularly imprinted polymers was grafted onto the vinyl‐modified magnetic nanoparticles by precipitation polymerization. FTIR spectroscopy, scanning electron microscopy, vibrating sample magnetometry, and thermogravimetric analysis were applied to characterize the sorbent properties. Moreover, the predominant parameters affecting the magnetic solid phase extraction such as sample pH, sorption and elution times, the amount of sorbent, and composition and volume of eluent were investigated thoroughly. The maximum sorption capacity of the imprinted polymer toward p‐aminosalicylic acid was 70.9 mg/g, which is 4.5 times higher than that of the magnetic nonimprinted polymer. The magnetic molecularly imprinted polymer nanoparticles were applied for the selective extraction of p‐aminosalicylic acid from aqueous and urine samples and satisfactory results were achieved. The results illustrate that magnetic molecularly imprinted polymer nanoparticles have a great potential in the extraction of p‐aminosalicylic acid from environmental and biological matrices.  相似文献   
989.
990.
Electrochemical dimerization of vanillin in basic medium produced mixtures of meso/DL-hydrovanilloins, in contrary to earlier claims of the formation of meso-hydrovanilloin as the sole product. In the reinvestigation we have found that meso-percentage depends on the current density and the highest meso-percentage of 94% is achieved under 64 mA/cm2 current density, using Pb electrodes and 1.25 M aqueous NaOH as the electrolyte. Condensation of the renewable resources based monomer hydrovanilloin with formaldehyde in aqueous NaOH gives hydrovanilloin–formaldehyde polymer in 91% yield. The linear polymer is shown to contain hydrovanilloin units with methylene bridges connecting C-6 positions of the aromatic rings.  相似文献   
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