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41.
To establish a quicker preparation procedure for cryoprecipitate (Cryo) from a patient's autologous plasma, to be used as fibrin glue, we examined the effects of various conditions on the concentrations and yields of coagulation factors in Cryo. Human plasma from healthy volunteers was divided and treated under various freezing, shaking and defrosting conditions. The concentrations of fibrinogen, plasminogen, fibronectin, and factor XIII in Cryo were then measured. Results were as follows: (1) concentrations and yields of plasma components in Cryo obtained from plasma stored at -20 degrees C were significantly higher than those in Cryo from plasma stored at -80 degrees C; (2) shaking at 70 cycles/min during the freezing process had a favorable effect on the concentrations and yields of coagulation factors in the Cryo; (3) a shaking thaw process in a cold water bath was a rapid method for obtaining adequate yields of coagulation factors; (4) shaking in the defrosting process did not affect the yields of coagulation factors. These results indicated that Cryo containing high concentrations of coagulation factors could be prepared easily and rapidly from a patient's autologous plasma (within 4-5 h). 相似文献
42.
Tominaga J Michizoe J Kamiya N Ichinose H Maruyama T Goto M 《Journal of Bioscience and Bioengineering》2004,98(1):14-19
Catalytic oxidation of biphenyl derivatives was investigated using laccase in a homogeneous aqueous-organic system. A thermostable laccase from Trametes sp. showed the highest catalytic activity for the oxidation of 4-hydroxybiphenyl (4-HB) at a reaction temperature of 60 degrees C when dimethylsulfoxide (DMSO) was employed as a co-solvent. Furthermore, the catalytic performance was successfully enhanced by the incorporation of a laccase mediator system (LMS) into the aqueous-DMSO media. The catalytic performance strongly depended on the type of mediator, and the highest activity was observed with 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as mediator, suggesting the importance of the selection of a suitable mediator. It was verified that this mediator system is applicable to the oxidation of several biphenyl derivatives with hydroxyl groups. 相似文献
43.
44.
Takeba K Fujinuma K Sakamoto M Jimbo K Oka H Ito Y Nakazawa H 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2003,44(5):246-252
A simple and rapid liquid chromatographic method was developed for the simultaneous determination of twelve benzimidazole anthelmintics in livestock foods using reversed-phase high-performance liquid chromatography with photodiode array detection (PDA). A sample was homogenized with acetonitrile and n-hexane, and centrifuged. The acetonitrile phase was isolated and evaporated. The residue was dissolved in 0.1 mol/L carbonate buffer solution (pH = 9.1), sonicated, and then subjected to clean-up on a Bond Elut LRC-C18 cartridge. The benzimidazole compounds were separated isocratically on a Capcell Pak C18 UG 120 (5 microns, 150 x 4.6 mm i.d.) column and detected by PDA at 295 and 313 nm. Mixtures of acetonitrile and 0.05 mol/L ammonium acetate in mixing ratios of (20:80) and (40:60) were used as the mobile phase, and the flow-rate was 1.0 mL/min at 40 degrees C. The mean recoveries (n = 3) from 0.1-0.5 microgram/g added samples were 72.6-97.2% with coefficients of variation of 0.3-8.5%. The detection limits were 0.01-0.05 microgram/g. 相似文献
45.
We examined the biological effects of porcine enamel matrix derivative (EMD; Emdogain) on the formation of reparative dentine and dentine bridges in rat molars after pulp amputation. The pulp chambers of upper molars of Wistar rats were perforated and the amputated pulp surfaces were directly capped with either EMD or its carrier propylene glycol alginate (PGA) as control. The cavities were then restored with glass-ionomer cement. On post-amputation days 4-30, the dissected maxillae were examined by light and electron microscopy. In PGA-capped pulp, reparative dentine had been formed over the dentine walls under the prepared cavity on day 7 post-amputation and its thickness extended until day 30. On day 30, as well as reparative dentine formation, diffuse calcification had occurred beneath the amputated wound surfaces. Dentine bridge formation under the amputated coronal pulp surface was observed in 18.2% of amputated pulp on day 30. In EMD-capped pulp, reparative dentine had already been formed by odontoblast-like cells over the dentine walls, already on day 4 post-amputation, and its thickness extended until day 30. The Ca and P weight % and Ca/P ratio of reparative dentine matrix were similar to those of pre-existing dentine matrix, and these values were not different between PGA and EMD-capped pulp. Dentine bridge formation was observed in 27.3% of EMD-capped pulp on day 30. Our results suggest that EMD enhances the formation of both reparative dentine and dentine bridges during wound healing of amputated rat molar pulp. 相似文献
46.
Takashi Kojima Yasuki Mori Masahiro Kamiya Ryo Sasai Hideaki Itoh 《Journal of Materials Science》2007,42(15):6056-6061
Capability of the recycling of high strength and high fracture toughness yttria-stabilized tetragonal zirconia polycrystalline
(Y-TZP) sintered body utilizing “low-temperature annealing degradation” phenomenon was investigated. Hydrothermal treatment
was employed to induce the phase transformation from tetragonal to monoclinic zirconia and to disintegrate the Y-TZP sintered
body. 3 mol% Y2O3–ZrO2 specimens sintered at 1,550 °C and more were disintegrated without leaving the original appearances when the treatment temperature
was between 200 °C and 400 °C. The size of the disintegrated fragments of Y-TZP sintered body was much affected by hydrothermal
treatment conditions. Only with hydrothermal treatment and simple ball milling, the sintered body was pulverized into the
primary particle level. This technique is expected to apply to a sustainable recycling system for the zirconia ceramics, which
restrains an energy consumption compared to crushing zirconia using mechanical procedures. 相似文献
47.
CdSe microcrystals were successfully dispersed in GeO2 glass andCaF2 crystal thin films by rf-sputtering. All films preparedshowed the blue shift of absorption edge in visible spectra due toquantum size effect. The amount of the blue shift of the filmsincreased with decreasing the size of the microcrystals. Comparingthe amount of the particle size–depending blue shift of CdSemicrocrystals dispersed in between the GeO2, CaF2 and SiO2 matricies, the influence of the matrix on the shift was found.Therefore, it can be said that there is an influence of the matrix onthe quantum size effect. From the modified theoretical calculation,the influence of matrix was considered to appear through Coulombinteraction between electrons and holes. 相似文献
48.
49.
This article presents a study of the effect of through-the-thickness stitching yarns upon the strength and failure behavior
of multidirectionally reinforced composites. The in-plane yarns were placed in four directions (0,±45, 90) to form a quasi-isotropic
preform, which had open spaces between adjacent yarns. These interyarn spaces allowed easy insertion of the through-the-thickness
stitching yarns without significant damage of the in-plane fibers. Fiber volume fractions of over 54 pct were obtained by
this method. The through-the-thickness yarn sizes used in this study were 2, 4, and 6 kilo-filament (kf). Non-stitched performs
were also manufactured with the same fiber content and by the same procedure as the stiched preforms for the control experiments.
All preforms were infiltrated with epoxy resin by the resin transfer molding (RTM) technique. In-plane tensile and compressive
strength, interlaminar shear strength, and mode I fracture toughness of the carbon/epoxy composites were measured at three
through-the-thickness yarn contents. Although the through-the-thickness yarns significantly enhanced the mode I fracture toughness,
they tended to degrade the in-plane tensile and compressive strength. The failure process under interlaminar shear loading
by double notch shear tests showed two distinct stages: the fiber-matrix interfacial failure followed by the breakage/debonding
of the through-the-thickness yarns. The through-the-thickness yarns caused a reduction of the initial failure load in the
first stage but could enhance the final failure load in the second stage. In composites with 6 kf through-the-thickness yarns,
the final failure load could exceed the initial failure load. Scanning electron microscope (SEM) and optical microscopic examinations
were also conducted for observing the failure mechanisms and fracture surfaces.
This article is based on a presentation made in the Symposium “Mechanisms and Mechanics of Composites Fracture” held October
11–15, 1998, at the TMS Fall Meeting in Rosemont, Illinois, under the auspices of the TMS-SMD/ASM-MSCTS Composite-Materials
Committee. 相似文献
50.