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L. Ignat M. IgnatC. Ciobanu F. DorofteiV.I. Popa 《Industrial Crops and Products》2011,34(1):1017-1028
Lignin use in polymer industry has recently become very attractive from both economical and environmental reasons. In the specific case of blending, the addition of low lignin amounts was found to improve the properties and extends the application field of other natural or synthetic polymers, but the effects of oxidative enzymes on resulting blends are widely unknown. Thereby, the current study was carried out to determine some potential effects of small flax lignin concentrations (4.2 and 9.3 wt%) on the enzymatic degradation of a poly(ethylene adipate) urethane (PU). Thin cast films of PU and its lignin blends were incubated for 3 days at 30 °C with buffered solutions of fungal peroxidase and laccase extracted from Aspergillus sp., and compared with the untreated ones. Changes in surface structure and morphology were investigated by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM), while the impact on bulk was assessed from tensile tests and thermogravimetry analysis (TGA). Although the addition of flax lignin reduces the surface structural modifications after enzyme treatment, the morphology, tensile and thermo-oxidative characteristics are still affected, with laccase showing the higher degradative efficiency. The lignin concentration, its high impact on the resulting blends morphology and relative low resistance to laccase and peroxidase degradation was the most important factors proved to driven the enzymatic oxidation. 相似文献
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Suat Cetiner Marius Olariu Romeo Ciobanu Hale Karakas Fatma Kalaoglu A. Sezai Sarac 《Fibers and Polymers》2010,11(6):843-850
Spectrophotometric, morphologic and dielectric properties of polyacrylonitrile (PAN) composite films in the presence of pyrrole
derivatives were reported in this paper. The composite films were fabricated by oxidative polymerization of pyrrole (Py),
N-methyl pyrrole (NMPy) and N-phenyl pyrrole (NPhPy) by cerium(IV) on polyacrylonitrile matrix. The effect of temperature
on the dielectric properties was studied in the frequency range from 0.05 Hz up to 10 MHz and in the temperature range from
0 °C up to 250 °C. Conductivity was increased with temperature due to increase of the mobility of charge carriers in the composite
films. By increasing the temperature, the dipoles become free and respond to the applied electric field in composite structure;
thus, the polarization and dielectric constant increases. PNPhPy-PAN composite films exhibited the highest dielectric constant,
AC conductivity and tan delta. 相似文献
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Danko Abramiuc Luminita Ciobanu Rodica Muresan Magda Chiosac Augustin Muresan 《Fibers and Polymers》2013,14(11):1826-1833
The paper discusses a method to functionalize cotton fabrics using biologically active natural compounds to achieve the antibacterial characteristics required for medical application. The biologically active natural compounds include propolis, beeswax, and chitosan. Three 100 % cotton knitted fabrics with different degrees of compactness were impregnated in the emulsions containing the active ingredients and fabric variant G3 with the highest degree of impregnation was considered for the evaluation of the antibacterial properties and comfort characteristics. The results show that the treated cotton fabric had high antibacterial activity against both gram positive bacteria Staphylococcus aureus and Streptococcus β haemolytic, and gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The presence of the biologically active natural compounds on the cotton substrates modified the surface of the textile fibers as seen in the SEM images. The treatment also improved fabric comfort properties, the cotton substrates became less air permissive and more hygroscopic after the treatment. The experimental results indicated that propolis, beeswax and chitosan can be applied as an emulsion to functionalize cotton textile materials. The antibacterial performance of the functionalized fabrics suggested that the cotton fabrics treated with those biologically active natural compounds have the potentials to be used in medical fields. 相似文献
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Ciobanu DC Bastiaansen JW Lonergan SM Thomsen H Dekkers JC Plastow GS Rothschild MF 《Journal of animal science》2004,82(10):2829-2839
Suggestive QTL affecting raw firmness scores and average Instron force, tenderness, juiciness, and chewiness on cooked meat were mapped to pig chromosome 2 using a three-generation intercross between Berkshire and Yorkshire pigs. Based on its function and location, the calpastatin (CAST) gene was considered to be a good candidate for the observed effects. Several missense and silent mutations were identified in CAST and haplotypes covering most of the coding region were constructed and used for association analyses with meat quality traits. Results demonstrated that one CAST haplotype was significantly associated with lower Instron force and cooking loss and higher juiciness and, therefore, this haplotype is associated with higher eating quality. Some of the sequence variation identified may be associated with differences in phosphorylation of CAST by adenosine cyclic 3', 5'-monophosphate-dependent protein kinase and may in turn explain the meat quality phenotypic differences. The beneficial haplotype was present in all the commercial breeds tested and may provide significant improvements for the pig industry and consumers because it can be used in marker-assisted selection to produce naturally tender and juicy pork without additional processing steps. 相似文献
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Efficacy of temozolomide or dacarbazine in combination with an anthracycline for rescue chemotherapy in dogs with lymphoma 总被引:2,自引:0,他引:2
Dervisis NG Dominguez PA Sarbu L Newman RG Cadile CD Swanson CN Kitchell BE 《Journal of the American Veterinary Medical Association》2007,231(4):563-569
OBJECTIVE: To compare results of treatment with temozolomide or dacarbazine, in combination with an anthracycline, in dogs with relapsed or refractory lymphoma. DESIGN: Nonrandomized, controlled clinical trial. ANIMALS: 63 dogs with relapsed or refractory lymphoma. PROCEDURES: Chemotherapy was administered in 21-day cycles. A combination of temozolomide and an anthracycline (doxorubicin or dactinomycin) was administered to 21 dogs and a combination of dacarbazine and an anthracycline was administered to 42 dogs. Efficacy and toxicoses were assessed. Results-Thirteen of the 18 (72%) dogs treated with the temozolomide-anthracycline combination and 25 of the 35 (71%) dogs treated with the dacarbazine-anthracycline combination had a complete or partial response. Median duration of response to rescue chemotherapy was 40 days (range, 0 to 217 days) for dogs in the temozolomide group and 50 days (range, 0 to 587 days) for dogs in the dacarbazine group. The incidence of high-grade hematologic toxicoses was significantly higher among dogs in the dacarbazine group than among dogs in the temozolomide group, but the incidence of gastrointestinal tract toxicoses was not significantly different between groups. There were no significant differences between groups in regard to proportion of dogs with a complete or partial response, duration of response to rescue chemotherapy, survival time following rescue chemotherapy, or overall survival time. CONCLUSIONS AND CLINICAL RELEVANCE: Both combinations had promise in the treatment of dogs with relapsed or refractory lymphoma, although administration of temozolomide was more convenient than administration of dacarbazine and caused fewer hematologic toxicoses. 相似文献
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S.E.F. Guimaraes M.F. Rothschild D. Ciobanu C.H. Stahl & S.M. Lonergan 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2007,124(4):246-253
The SDHD gene was examined for single nucleotide polymorphisms (SNP) as well as for expression changes in the Longissimus dorsi muscle of commercial pigs with different potential for growth. Three SNPs, including one previously described in the coding region and two new ones in the 3'-UTR, were found. The normalized expression of SDHD was correlated with growth, meat quality and sensory traits (p < 0.05). For the commercial pigs used in this study, as well as a Berkshire × Yorkshire resource population, the SNPs have been associated (p < 0.05) with: growth, carcass composition, meat quality and sensory traits. Despite the fact that the described SNPs were not significantly associated with the normalized expression values, the SDHD SNPs and expression were associated with growth and meat quality traits in pigs. 相似文献