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191.
Microporous divinyl benzene copolymer (MDBP) was used for the first time as immobilization material for Saccharomyces cerevisiae ATCC 26602 cells in a bed reactor and ethanol production from glucose was studied as a model system. A very homogenous thick
layer of yeast cells were seen from the scanning electron micrographs on the outer walls of biopolymer. The dried weight of
the cells was found to be approximately 2 g per gram of cell supporting material. Hydrophobic nature of polymer is an important
factor increasing cell adhesion on polymer pieces. The dynamic flow conditions through the biomaterial due to its microporous
architecture prevented exopolysaccharide matrix formation around cells and continuous washing out of toxic metabolites and
dead and degraded cells from the reactor provided less diffusional limitations and dynamic living environment to the cells.
In order to see the ethanol production performance of immobilized yeast cells, a large initial concentration range of glucose
between 6.7 and 300 g/l was studied at 1 ml/min in continuous packed-bed reactor. The inhibition effect of glucose with increasing
initial concentration was observed at above 150 g/l, a relatively high substrate concentration. The continuous fluid flow
around the microenvironment of the attached cells and mass transferring ability of cell immobilized on MDBP can help in decreasing
the inhibition effect of ethanol accumulation and high substrate concentration in the vicinity of the cells. 相似文献
192.
Valentyna P. Tokar Mykhaylo Yu. Losytskyy Tymish Y. Ohulchanskyy Dmytro V. Kryvorotenko Vladyslava B. Kovalska Anatoliy O. Balanda Igor M. Dmytruk Vadym M. Prokopets Sergiy M. Yarmoluk Valeriy M. Yashchuk 《Journal of fluorescence》2010,20(4):865-872
Spectral-fluorescent properties of benzothiazole styryl monomer (Bos-3) and homodimer (DBos-21) dyes in presence of DNA were
studied. The dyes enhance their fluorescence intensity in 2–3 orders of magnitude upon interaction with DNA. Studied styrylcyanines
in DNA presence demonstrate rather high values of two-photon absorption (TPA) cross-section, which are comparable with the
values of TPA cross section of the rhodamine dyes. An applicability of the styrylcyanines as probes for the fluorescence microscopy
of living cells was studied. It was shown that both dyes are cell-permeable but homodimer dye DBos-21 produces noticeably
brighter staining of HeLa cells comparing with monomer dye Bos-3. Molecules of DBos-21 initially bind to the nucleic acids-
containing cell organelles (presumable mitochondria) and are able to penetrate into the cell nucleus. Thus, homodimer styryl
DBos-21 dye is viewed as efficient stain for single-photon and two-photon excitation fluorescence imaging of living cells. 相似文献
193.
We introduce a new solution for two-person bargaining problems: the iterated egalitarian compromise solution. It is defined by using two prominent bargaining solutions, the egalitarian solution (Kalai, 1977) and the equal-loss solution (Chun, 1988), in an iterative fashion. While neither of these two solutions satisfy midpoint domination – an appealing normative property – we show that the iterated egalitarian compromise solution does so. 相似文献
194.
Summary: Radical-initiated terpolymerization of maleic anhydride (MA), N-vinyl-2-pyrrolidone (NVP) with N-isopyropyl acrylamide (NIPA) has been prepared as a way to obtain new water-soluble polymers. Structure, composition and thermal behaviour of synthesized terpolymers were determined by FTIR, UV-vis, 1H NMR spectroscopy, elemental analysis (N content), differential scanning calorimetry, thermogravimetric and differential thermal analysis, gel permeation chromatography analysis (GPC), scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). The terpolymer composition-structure-property relationship indicates that the semicrystalline structure of terpolymers with different reaction times, degrees of crystallinity, and thermal behaviour depends on the content of carboxyl and amide-containing monomer linkage. The antimicrobial activities the terpolymers were evaluated against pathogen bacteria: Staphylococcus aureus, Salmonella enteridis, Streptococcucs faecalis, Eschericia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The antimicrobial activity was explored by the well-diffusion technique. All the studied polymers, containing biologically active moieties in the form of ionized cyclic amide and carboxylic acid groups, were more effective against Gram-positive than Gram-negative bacteria. The bactericidal effect of terpolymers against Gram negative bacteria increased with the increasing reaction times. 相似文献
195.
Fluorescence of Styryl Dyes-DNA Complexes Induced by Single- and Two-Photon Excitation 总被引:1,自引:1,他引:0
Tokar VP Losytskyy MY Kovalska VB Kryvorotenko DV Balanda AO Prokopets VM Galak MP Dmytruk IM Yashchuk VM Yarmoluk SM 《Journal of fluorescence》2006,16(6):783-791
The series of novel monomer and homodimer styryl dyes based on (p-dimethylaminostyryl) benzothiazolium residues were synthesized and studied as possible fluorescent probes for nucleic acids
detection. Spectral-luminescent and spectral-photometric properties of obtained dyes in the unbound state and in DNA presence
were studied. Fluorescence emission induced by two-photon excitation of dye-DNA complexes in aqueous buffer solution was registered.
Two-photon absorption cross section values of the studied dyes in DNA presence were evaluated. 相似文献
196.
Elif Basak Ersoy Nuket Ocal 《Phosphorus, sulfur, and silicon and the related elements》2019,194(3):257-268
1,3-Dipolar cycloaddition reactions were studied to synthesize Polyhedral oligomeric silsesquioxane (POSS)-based norbornyl imide derivatives containing izoxazoline groups in good yields. And also 1,3-dipolar cycloaddition reactions of azomethine ylides with POSS-based norbornene dipolarophiles for a synthesis of the novel POSS-based norbornane-fused spiro-1,3-indandionolylpyrrolidines are reported. All newly synthesized POSS compounds were structurally characterized by FTIR, 1H, 13C NMR, HRMS and GC/MS analyses. 相似文献
197.
Doğan-Sağlamtimur Neslihan Bilgil Ahmet Güven Adnan Ötgün Halime Yıldırım Elif Dilan Arıcan Büşra 《Journal of Thermal Analysis and Calorimetry》2019,135(6):3339-3351
Journal of Thermal Analysis and Calorimetry - Waste tyre and waste polyethylene terephthalate (PET) bottles are major environmental problems. In this study, by using newly designed simple and... 相似文献
198.
199.
An Integrated Inventory-Routing System for Multi-item Joint Replenishment with Limited Vehicle Capacity 总被引:4,自引:0,他引:4
Sombat?SindhuchaoEmail author H.?Edwin.?Romeijn Elif?Ak?ali Rein?Boondiskulchok 《Journal of Global Optimization》2005,32(1):93-118
In this paper, we develop a mathematical programming approach for coordinating inventory and transportation decisions in an inbound commodity collection system. In particular, we consider a system that consists of a set of geographically dispersed suppliers that manufacture one or more non-identical items, and a central warehouse that stocks these items. The warehouse faces a constant and deterministic demand for the items from outside retailers. The items are collected by a fleet of vehicles that are dispatched from the central warehouse. The vehicles are capacitated, and must also satisfy a frequency constraint. Adopting a policy in which each vehicle always collects the same set of items, we formulate the inventory-routing problem of minimizing the long-run average inventory and transportation costs as a set partitioning problem. We employ a column generation approach to determine a lower bound on the total costs, and develop a branch-and-price algorithm that finds the optimal assignment of items to vehicles. We also propose greedy constructive heuristics, and develop a very large-scale neighborhood (VLSN) search algorithm to find near-optimal solutions for the problem. Computational tests are performed on a set of randomly generated problem instances.The work of this author was supported by a scholarship of the Faculty of Engineering of Ubonratchathani University, Ubonratchathani, Thailand., The work of this author was supported in part by the National Science Foundation under Grant No. DMI-0085682. 相似文献
200.
A model for the transition to the radiatively improved (RI) mode triggered in tokamaks by seeding of impurities is proposed. This model takes into account that with increasing plasma effective charge the growth rate of the toroidal ion temperature gradient (ITG) instability, considered nowadays as the dominant source of anomalous energy losses in low-confinement (L) mode, decreases. As a result the plasma density profile peaks due to an inward convection generated by trapped electron turbulence. This completely quenches ITG induced transport and a bifurcation to the RI mode occurs. Conditions necessary for the L-RI transition are investigated. 相似文献