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排序方式: 共有105条查询结果,搜索用时 828 毫秒
51.
Barbara Lorkowska-Zawicka Kamil Kamiński Justyna Ciejka Krzysztof Szczubia?ka Magdalena Bia?as Krzysztof Okoń Dariusz Adamek Maria Nowakowska Jacek Jawień Rafa? Olszanecki Ryszard Korbut 《Marine drugs》2014,12(7):3953-3969
This study was performed to evaluate the ability of N-(2-hydroxypropyl)-3-trimethylammonium chitosan chloride (HTCC), the cationically modified chitosan, to form biologically inactive complexes with unfractionated heparin and thereby blocking its anticoagulant activity. Experiments were carried out in rats in vivo and in vitro using the activated partial thromboplastin time (APTT) and prothrombin time (PT) tests for evaluation of heparin anticoagulant activity. For the first time we have found that HTCC effectively neutralizes anticoagulant action of heparin in rat blood in vitro as well as in rats in vivo. The effect of HTCC on suppression of heparin activity is dose-dependent and its efficacy can be comparable to that of protamine-the only agent used in clinic for heparin neutralization. HTCC administered i.v. alone had no direct effect on any of the coagulation tests used. The potential adverse effects of HTCC were further explored using rat experimental model of acute toxicity. When administered i.p. at high doses (250 and 500 mg/kg body weight), HTCC induced some significant dose-dependent structural abnormalities in the liver. However, when HTCC was administered at low doses, comparable to those used for neutralization of anticoagulant effect of heparin, no histopathological abnormalities in liver were observed. 相似文献
52.
53.
Wright DW Eaton DK Nielsen LT Kuhrt FW Koziel JA Spinhirne JP Parker DB 《Journal of agricultural and food chemistry》2005,53(22):8663-8672
Odor profiling efforts were directed at applying to high-density livestock operations some of the lessons learned in resolving past, highly diverse, odor-focused investigations in the consumer product industry. Solid-phase microextraction (SPME) was used for field air sampling of odorous air near and downwind of a beef cattle feedyard and a swine finisher barn in Texas. Multidimensional gas chromatography-olfactometry (MDGC-O) was utilized in an attempt to define and prioritize the basic building blocks of odor character associated with these livestock operations. Although scores of potential odorant volatiles have been previously identified in high-density livestock operations, the odor profile results developed herein suggest that only a very few of these may constitute the preponderance of the odor complaints associated with these environments. This appeared to be especially true for the case of increasing distance from both cattle feedyard and swine barn facilities, with p-cresol consistently taking on the dominant odor impact role with ever increasing distance. In contrast, at- or near-site odor profiles were shown to be much more complex, with many of the well-known lower tier odorant compounds rising in relative significance. For the cattle feedyard at- or near-site odor profiles, trimethylamine was shown to represent a significantly greater individual odor impact relative to the more often cited livestock odorants such as hydrogen sulfide, the organic sulfides, and volatile fatty acids. This study demonstrates that SPME combined with a MDGC-O-mass spectrometry system can be used for the sampling, identification, and prioritization of odors associated with livestock. 相似文献
54.
Antioxidant capacity manipulation in transgenic potato tuber by changes in phenolic compounds content 总被引:1,自引:0,他引:1
Lukaszewicz M Matysiak-Kata I Skala J Fecka I Cisowski W Szopa J 《Journal of agricultural and food chemistry》2004,52(6):1526-1533
The main goal of this study was to generate potato tubers with increased levels of flavonoids and thus modified antioxidant capacities. To accomplish this, the vector carrying multigene construct was prepared and several transgenic plants were generated, all overexpressing key biosynthesis pathway enzymes. The single-gene overexpression or simultaneous expression of genes encoding chalcone synthase (CHS), chalcone isomerase (CHI), and dihydroflavonol reductase (DFR) resulted in a significant increase of measured phenolic acids and anthocyanins. The increase in phenolic compounds synthesis is accompanied by decreases in starch and glucose levels in transgenic plants. The flavonoids-enriched plants showed improved antioxidant capacity; however, there is a complex relationship between antioxidant capacity and flavonoids content, suggesting the great participation of other compounds in the antioxidant potential of the plants. These other compounds are not yet recognized. 相似文献
55.
Lorenc-Kukuła K Amarowicz R Oszmiański J Doermann P Starzycki M Skała J Zuk M Kulma A Szopa J 《Journal of agricultural and food chemistry》2005,53(9):3685-3692
The principal goal of this paper was to generate flax (Linum usitatissimum L.) plants with increased antioxidant properties. To accomplish this a vector containing a multigene construct was prepared, and transgenic plants overexpressing essential flavonoid biosynthesis pathway enzymes were generated and analyzed. The simultaneous expression of genes encoding chalcone synthase (CHS), chalcone isomerase (CHI), and dihydroflavonol reductase (DFR) resulted in a significant increase of flax antioxidant capacity. To investigate the determinants of higher antioxidant properties of transgenic plants, the phenolic acids and lignans compound contents were measured. In both green part and seed extracts from transgenic plants, the phenolic acids level was increased when compared to the control. The calculated correlation coefficient between phenolic acids content and antioxidant capacity (0.82 and 0.70 for green part and flaxseed, respectively) perfectly reflects their strong relationship. The increase in yield of transgenic plants and their higher resistance to Fusarium culmorum and Fusarium oxysporum when compared to the control plants was a characteristic feature. It was assessed a very high correlation (correlation coefficient = 0.9) between phenolic acids level in flaxseed extract and resistance to F. culmorum. The flowering date of transgenic plants was approximately 3 weeks earlier than that of the control plants. Interestingly, a significant increase in monounsaturated fatty acids and a slight increase in lignans content accompanied the increase in antioxidant properties of flaxseeds. 相似文献
56.
Stachowska E Kijowski J Dziedziejko V Siennicka A Chlubek D 《Journal of agricultural and food chemistry》2011,59(21):11846-11852
Stimulation of macrophages by a variety fatty acids causes activation of MAP kinases (MAPKs). The consequences arising from down-regulation of MAPKs may be a limitation in the activity of PPARγ, which is modulated by a modification catalyzed by these kinases. Phosphorylation of MAP kinases-ERK1/2 and p38 as well as PPARγ was determined by real-time polymerase chain reaction and Western blotting in human macrophages cultured with conjugated linoleic acids (CLAs). We demonstrated that CLA isomers alter MAP kinase phosphorylation and PPARγ activation. Phosphorylation of ERK1/2 was diminished in cells cultivated with cis-9,trans-11 CLA, whereas phosphorylation of p38 was reduced by trans-10,cis-12 CLA. PPARγ was phosphorylated mainly by ERK1/2, and consequently, PPARγ phosphorylation was suppressed mainly by cis-9,trans-11 isomer. In human adipocytes, cis-9,trans-11 C 18:2 raised the activation of PPAR and several of its downstream target genes. We suggest that a similar process may also occur in human macrophages. 相似文献
57.
Thomas Scholten Christian Geißler Jacek Goc Peter Kühn Christoph Wiegand 《植物养料与土壤学杂志》2011,174(4):596-601
Splash cups have long been successfully used for both the quantification of kinetic energy of rainfall and the detachability of soil particles by rainfall impact, the so‐called “splash erosion”. Measurements of kinetic energy, however, have been difficult to operate in the field especially in remote areas, on steep slopes, and in forests since boundary conditions need to be controlled precisely. This paper introduces a new splash cup based on Ellison's archetype that reliably and accurately measures kinetic energy as a function of sand loss under a large variety of conditions. The Tübingen splash cup (T splash cup) is relatively easy to operate under harsh field conditions, and it can be used in experimental designs with a large number of plots and replications at reasonably low costs. The cup is constructed from plastic laboratory flasks and plastic pipes from water‐supply equipments. The unit sand is held by a removable carrier system that can easily be replaced in the field. The splash cups have been calibrated in combination with a laser distrometer using a linear regression function with r2 = 0.98. They measure kinetic energy over a wide range of rainfall intensities from 0.6 to 40 L m–2 h–1. Kinetic energy per area varies between 10 and 250 J m–2. Two years of field test measurements in a subtropical forest ecosystem in China proved the reliability, durability, and usability of our new splash cups and allowed detecting differences in kinetic energy between different tree species and biodiversity levels. 相似文献
58.
Teresa Ostaszewska MichaŁ Korwin-Kossakowski Jacek Wolnicki 《Aquaculture International》2006,14(1-2):113-126
The aim of the study was to evaluate the effect of short-term starvation on the morphology of the digestive system of juvenile
tench Tinca tinca (L.). The morphological changes in digestive structures of juveniles, fed 70 days starter or Chironomidae larvae, were examined after 1, 12, 24 and 48 h of starvation at 28 °C. The morphological changes in the organisation of the
digestive structures were as follows: (1) Intestine – proteolysis of the intestinal mucosa, especially of enterocytes in apical
part of mucosal folds; (2) Liver – progressive reduction of lipid vacuoles and glycogen granules, and, in effect, volume reduction
of hepatocytes cytoplasm; (3) Pancreas – progressive degeneration of exocrine pancreatic cells, parallel with decrease of
zymogen activity. The fish fed natural food prior to starvation seem to be more resistant to starvation than those fed starter. 相似文献
59.
Bartosz Mysłowski Remigiusz Panicz Jacek Sadowski Paulina Hofsoe 《Aquaculture International》2013,21(4):739-750
The aim of this study was to characterize whitefish and peled populations in Miedwie Lake by means of the genetic analysis of ND-1 (NADH dehydrogenase 1) gene and the ITS-1 (internal transcribed spacer 1) region in order to distinguish native forms from whitefish/peled hybrids. In the analysis, archival specimens of Coregonus lavaretus maraena from the Berlin Museum für Naturkunde were used. Genetic analysis performed with the aid of MEGA 4.0 software explicitly indicated that samples from Miedwie Lake belonged entirely to a native (rapidly growing) form of whitefish. Furthermore, the conducted research has also provided crucial information for a C. lavaretus management program for Miedwie Lake. 相似文献
60.
Omega gliadin proteins are one of the most allergenic components of wheat gluten. Proteins of the ω-5 subgroup are recognized as main allergens causing wheat dependent exercise induced anaphylaxis—the most dangerous, life-threatening IgE mediated food allergy. A set of wheat genotypes lacking all ω-gliadins has been developed by cumulating inactive gene variants in three gliadin coding loci (Gli A1, Gli B1 and Gli D1), using traditional plant breeding methods. Endosperm proteins of ω-gliadin-free genotypes were compared to a control genotype containing all ω-gliadins by A-PAGE, SDS-PAGE and RP-HPLC. A considerable decrease (about 30 %) of gliadin immunoreactivity as a consequence of ω-gliadin elimination was demonstrated by ELISA, using sera of ten patients allergic to gluten. Preliminary evaluation of the technological properties of the ω-gliadin-free genotype by the SDS sedimentation test suggests that elimination of all ω-gliadins may also significantly improve wheat bread making quality. 相似文献