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21.
María Prados-Privado Juan Carlos Prados-Frutos José Luis Calvo-Guirado José Antonio Bea 《Computer methods in biomechanics and biomedical engineering》2016,19(15):1583-1591
To measure fatigue in dental implants and in its components, it is necessary to use a probabilistic analysis since the randomness in the output depends on a number of parameters (such as fatigue properties of titanium and applied loads, unknown beforehand as they depend on mastication habits). The purpose is to apply a probabilistic approximation in order to predict fatigue life, taking into account the randomness of variables. More accuracy on the results has been obtained by taking into account different load blocks with different amplitudes, as happens with bite forces during the day and allowing us to know how effects have different type of bruxism on the piece analysed. 相似文献
22.
23.
Antonio Grinyo 《Biotechnic & histochemistry》1968,43(1):19-25
Specimens of brain or spinal cord fixed in formalin, Cajal's formol-bromide, or Koenig, Groat and Windle's formalin-acacia can be used to stain oligodendrocytes in frozen, in paraffin, or in celloidin sections. The sections are soaked 3-5 min in 0.02% acetic acid, pH 3.4, then rinsed 2-3 sec in 3% H2O2 and transferred to a silver bath prepared as follows: Mix equal parts of 10% AgNO3 and 10% Na2WO4, and dissolve the precipitate with concentrated NH4OH; avoid an excess of ammonia. Silver at room temperature for 15-20 sec, develop in 1% formalin, dehydrate, and mount. For embedded material, prepare a mixture consisting of 1 part of 10% aqueous Aerosol MA and 4 parts of 10% Aerosol OT in 95% alcohol. Add 5 drops of this mixture to each 50 ml of dilute acetic acid and 3% H2O2; 5 drops to each 20 ml of the silver bath. 相似文献
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25.
Initial reaction rates for the hydrolysis of nucleic acids with micrococcal endonuclease (EC 3.1.31.1) insolubilized on Sepharose are strongly influenced by diffusional limitations. Although the absolute values are low, they can be increased substantially by changing particle and pore size of the support, or enzyme concentration in the insoluble derivative. As a result of steric and diffusional limitations, the course of the reaction and selectivity to hydrolysis products for the insoluble derivatives are different to those of the native enzyme; the former produces mainly large and small fragments but few of intermediate size. Because of these differences in course and selectivity of the reaction, diffusional limitations become less important when high initial reaction rates are not required. 相似文献
26.
Pedigree analysis is a central component of many current efforts to locate genes that contribute to diseases or to valuable traits. The analysis usually involves solving one of two very computation-intense problems. We analyze the complexity of these two problems. Surprisingly, we show that both problems are NP-hard even for pedigrees that contain no inbreeding loops. 相似文献
27.
Photosynthetically active vesicles prepared from Chlamydomonas reinhardtii retained a light-dependent glutamate synthase activity which was highly specific for 2-oxoglutarate (Km=2.1 mM) and L-glutamine (Km=0.9 mM) as amido group acceptor and donor respectively. This activity was inhibited by azaserine, p-hydroxymercuribenzoate and 3-(p-chlorophenyl)-1,1-dimethyl urea.Light-dependent synthesis of glutamate was also obtained by coupling Chlamydomonas photosynthetic particles to purified ferredoxin-glutamate synthase, using ascorbate and 2,6-dichlorophenol-indophenol as electron donor. This system was also specific for 2-oxoglutarate (Km=1 mM) and L-glutamine (Km=0.8 mM) as substrates, and was stimulated by dithioerythritol. Azaserine and p-hydroxymercuribenzoate, but not 3-(p-chlorophenyl)-1,1-dimethyl urea, inhibited the reconstituted activity; high concentrations of 2-oxoglutarate were inhibitory.Abbreviations A
Absorbance
- CCP
p-Trichlorometoxi-carbonylcyanide-phenylhydrazone
- Chl
Chlorophyll
- CMU
3-(p-Chlorophenyl)-1,1-dimethyl urea
- DPIP
2,6-Dichlorophenol-indophenol
- DTE
Dithioerythritol
- MSX
L-Methionine, D-L, sulfoximine
- MV
Methyl viologen 相似文献
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29.
Angeles Alonso-Moraga Antonio Bocanegra Juan M. Torres Juan López-Barea Carmen Pueyo 《Molecular and cellular biochemistry》1987,73(1):61-68
The intracellular concentrations of total glutathione, GSSG and protein · S-SG, the total excreted glutathione concentration, and the susceptibility towards GSH-reacting compounds were assayed in strains of Escherichia coli deficient in biosynthesis and/or reduction of glutathione. A deficiency in glutathione reductase displaced the glutathione status towards the oxidized forms. This displacement was more clearly appreciated in strains additionally deficient in glutathione biosynthesis. A deficiency in catalase activity also produced an increase in the oxidation of glutathione. The most severe changes were observed in the concentrations of protein-glutathione mixed disulfides and in the amount of glutathione excreted to the medium. Increased sensitivities towards compounds known to interact with cellular GSH were observed in glutathione reductase deficient strains, although these effects were enhanced in strains additionally deficient in GSH biosynthesis 相似文献
30.
Mauro Moresi Michele Patete Antonio Trunfio 《Applied microbiology and biotechnology》1989,31(5-6):495-501
Summary A whey fermentation by Kluyveromyces fragilis was scaled-up to a 1000-dm3 stirred fermentor, by varying the stirrer speed, the air-flow rate and the initial concentration of lactose. Its evolution was simulated by applying the same unstructured model (consisting of a microbial specific growth rate of pseudo-first order with respect to the COD concentration and constant biomass yield per unit COD removed) set up in previous experiments using 8- to 80-dm3 fermentors. Despite the great scale-up ratios, very different operating conditions, and geometric dissimilarity, a series of empirical regressions previously developed allowed approximate, but acceptable prediction of the stoichiometric and kinetic coefficients of the above mathematical model, thus confirming the capability of this model to provide a reliable basis for further scale-up of this fermentation process to a production scale. 相似文献