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41.
H Horiuchi H Matsuda M Murata 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1990,52(3):559-565
The thrombocyte extracts (TE) and thrombocyte-secretion products (TSP) prepared from chicken peripheral blood were examined for the growth activity of chicken embryo fibroblasts (CEF). When the cells were incubated with TE and TSP, the enhancement of cell spreading was observed within one hour after seeding, but the control culture showed little spreading. Three to six days after cell seeding, the increase of the cell densities in the culture supplemented with TE and TSP was noticed in comparison with the culture without thrombocyte materials. The results strongly indicate the possibility for the presence of thrombocyte-derived growth factor(s) to CEF. 相似文献
42.
43.
Ann Mari Fransson 《Soil biology & biochemistry》2007,39(5):1213-1217
Plant roots and soil microorganisms contain significant quantities of low molecular weight (MW) phosphorylated nucleosides and sugars. Consequently, upon death these can represent a significant input of organic-P to the soil. Some of these organic-P substrates must first be dephosphorylated by phosphatases before being assimilated by the soil microbial community while others can be taken up directly from soil solution. To determine whether sorption or phosphatase activity was limiting the bioavailability of low MW organic-P in soil we compared the microbial uptake and C mineralization of a range of 14C-labeled organic-P substrates [glucose-6-phosphate, adenosine monophosphate (AMP), adenosine diphosphate (ADP) and adenosine triphosphate (ATP)] to that of the parent compounds (adenosine and glucose). In a fertile grassland soil we showed that at low organic-P substrate concentrations (<0.5 mM) phosphatase activity did not limit microbial uptake or mineralization in comparison to their non-phosphorylated counterparts. However, at high substrate concentrations (1-10 mM) the mineralization of the organic-P compounds was significantly lower than that of the non-phosphorylated compounds suggesting that phosphatase activity or microbial transporter capacity limited bioavailability. Sorption to the solid phase followed the series glucose<adenosine<G-6-P<AMP<ADP=ATP. However, sorption of the organic-P compounds to the solid phase did not appear to greatly affect bioavailability. The high adenosine mineralization capacity of the microbial biomass suggests that nucleosides may represent a significant source of C and N to the soil microbial biomass. We conclude that at low organic-P substrate concentrations typical of those in soil, neither phosphatase activity nor sorption greatly limits their bioavailability. 相似文献
44.
Junling An Ling Zhou Meiyuan Huang Hu Li Tsunehiko Otoshi Kazuhide Matsuda 《Water, air, and soil pollution》2001,130(1-4):1205-1210
Uncertainties in the assessment of critical loads for acidic deposition are caused by the choice of biological indicators (BI), critical chemical values (CCV), the current methods used to determine critical loads for an ecosystem, and deficient field data. This paper focuses on the present steady-state mass balance (SSMB) approach, dynamic models and the importance of changes in atmospheric base-cation deposition (BCD), particularly in China. It is argued that 1) for the SSMB approach much uncertainty may come from the choice of BI and the related CCV, and long-term and large-scale monitoring data on weathering rates and growth uptake are urgently needed, especially in China, 2) significant uncertainty may be caused by changes in BCD during SO2 emission controls, particularly in China, 3) constructing a mechanistic Al submodel may be a promising direction for dynamic models, and 4) the nutrient cycle in the vegetation through biogeochemical processes should be incorporated into dynamic models but the input requirements should be moderate for broad application considerations. Generally higher BCD, different soil components and characteristics and different vegetation types in China compared to Europe and North America suggest that more field investigations on BI and their corresponding CCV be carried out before application of current approaches to specific areas, particularly in China. 相似文献
45.
Tetsuya Suzuki Jun Itakura Masumi Watanabe Mari Ohta Yuri Sato Yuko Yamaya 《Journal of agricultural and food chemistry》2002,50(1):230-234
Electrolyzed anodic NaCl solutions [EW+], prepared by the electrolysis of 0.1% NaCl, have been shown to instantly inactivate most pathogens that cause food-borne disease. Elimination of food-borne pathogens does not necessarily guarantee food safety because enterotoxins produced by pathogens may remain active. We have tested whether EW+ can inactivate Staphylococcal enterotoxin A (SEA), one of the major enterotoxins responsible for food poisoning. Fixed quantities of SEA were mixed with increasing molar ratios of EW+, and SEA was evaluated by reversed-phase passive latex agglutination (RPLA) test, immunoassay, native polyacrylamide gel electrophoresis (PAGE), and amino acid analysis after 30 min incubations. Exposure of 70 ng, or 2.6 pmol, of SEA in 25 microL of PBS to a 10-fold volume of EW+, or ca. 64.6 x 10(3)-fold molar excess of HOCl in EW+, caused a loss of immuno-reactivity between SEA and a specific anti-SEA antibody. Native PAGE indicated that EW+ caused fragmentation of SEA, and amino acid analysis indicated a loss in amino acid content, in particular Met, Tyr, Ile, Asn, and Asp. Staphylococcal enterotoxin-A excreted into culture broth was also inactivated by exposure to an excess molar ratio of EW+. Thus, EW+ may be a useful management tool to ensure food hygiene by food processing industries. 相似文献
46.
The sensory quality and chemical constituents of juices from seven sea buckthorn (Hippophaerhamnoides L.) varieties were studied in two consecutive seasons. The juices were generally described as sour and astringent, with low sweetness and fruity flavor. The differences in sensory quality as well as in chemical composition between samples and years were significant (p < 0.05) in most parameters studied. The Chuiskaya variety was described as the sweetest, with the strongest fruity flavor, whereas the varieties Avgustinka, Botanicheskaya, Trofimovskaya, and Raisa were the sourest and most astringent. Total sugar (fructose and glucose) varied from 1.9 to 7.1 g/100 mL in juice, total acid (malic and quinic acids) from 3.1 to 5.1 g/100 mL, vitamin C from 29 to 176 mg/100 mL, and pulp oil from 0.7 to 3.6%. The soluble solids were between 7.4 and 12.6, the pH between 2.7 and 2.9, and the titrable acidity between 2.0 and 3.7. The redness was highest on Avgustinka and Raisa, but there were no differences in yellowness. Total sugar and the sugar/acid ratio correlated positively with sweetness and negatively with sourness and astringency, whereas total acid and titrable acidity correlated positively with sourness and astringency and negatively with sweetness. 相似文献
47.
Nihei K Ying BP Murakami T Matsuda H Hashimoto M Kubo I 《Journal of agricultural and food chemistry》2005,53(3):608-613
This is the first report for secondary metabolites in an African medicinal plant, Pachyelasma tessmannii (Leguminosae). Four novel saponins, pachyelasides A-D, were isolated from the methanol extract of the root bark by using recycling HPLC. These compounds showed molluscicidal activity (LD(50) < or =8.0 mug/mL) against the South American snail, Biomphalaria glabratus. The structures were determined on the basis of extensive nuclear magnetic resonance spectroscopic and matrix-assisted laser desorption/ionization time-of-flight mass spectrometric studies. 相似文献
48.
Used with one of two surfactants (SDS, an anionic surfactant, and Triton X-100, a nonionic surfactant), the ligand, I? was evaluated as a washing agent for the desorption of Cd from naturally and artificially contaminated soils. Increasing amounts of the ligand, I?, with a surfactant, specifically removes higher levels of Cd but not Cu, Zn and Pb. After seven washings, the ligand, I? with the nonionic surfactant, Triton X-100, removed 65 and 90% of the Cd from soils I and II, containing respectively, to 15 and 1275 mg of Cd/kg. The ligand, I?, and the anionic surfactant, SDS, removed 35 and 70% of the Cd from soils I and II, respectively. Before washing, the carbonate fraction of soil I contained the most Cd (48%) while the exchangeable and carbonate fractions of soil II contained 29 and 33% of the total Cd, respectively. For soil I, SDS with/ without the ligand desorbed Cd mainly from the carbonate and oxide fractions, while only Triton X-100 with ligand I? could remove Cd from the exchangeable fraction. For soil II, Cd was desorbed from the exchangeable fraction only when either surfactant was used in combination with the ligand. Thus, a surfactant with ligand can extract specific heavy metals from soils and selective sequential extraction is useful in identifying which fraction can be targeted by the surfactant – ligand agent. 相似文献
49.
Volatile compounds of selected strawberry varieties analyzed by purge-and-trap headspace GC-MS 总被引:1,自引:0,他引:1
Hakala MA Lapveteläinen AT Kallio HP 《Journal of agricultural and food chemistry》2002,50(5):1133-1142
Six strawberry (Fragaria x ananassa Duch.) varieties, Senga Sengana, Jonsok, Polka, Korona, Bounty, and Honeoye, were studied in relation to composition of their volatile headspace compounds collected by dynamic purge-and-trap concentration. Also, the influence of cultivation technique on the volatile compounds was tested by comparing conventionally and organically cultivated strawberry varieties. In addition, the effect of geographical origin on strawberry volatiles was investigated. The emphasis of this study was lay in the industrial utilization of strawberry. A total of 52 different volatile compounds were determined from frozen strawberries grown in 1997 and 1998. In addition to individual compounds, total areas of chromatogram profiles were compared. The major esters were found to be methyl butanoate, ethyl butanoate, methyl hexanoate, and ethyl hexanoate. With the application of principal component analysis and analysis of variance to the data matrix, the varieties were classified into three groups. Var. Honeoye was most different from the others. Organic cultivation had no effect on strawberry volatiles. 相似文献
50.
K Harada O Kamimura H Kasai T Matsuda A Tonomura VV Moshchalkov 《Science (New York, N.Y.)》1996,274(5290):1167-1170
The microscopic mechanism of the matching effect in a superconductor, which manifested itself as the production of peaks or cusps in the critical current at specific values of the applied magnetic field, was investigated with Lorentz microscopy to allow direct observation of the behavior of vortices in a niobium thin film having a regular array of artificial defects. Vortices were observed to form regular and consequently rigid lattices at the matching magnetic field, at its multiples, and at its fractions. The dynamic observation furthermore revealed that vortices were most difficult to move at the matching field, whereas excess vortices moved easily. 相似文献