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141.
Tamás Juhász Zsolt Szengyel Nóra Szijártó Kati Réczey 《Applied biochemistry and biotechnology》2004,113(1-3):201-211
Currently, the high market price of cellulases prohibits commercialization of the lignocellulosics-to-fuel ethanol process,
which utilizes enzymes for saccharification of cellulose. For this reason research aimed at understanding and improving cellulase
production is still a hot topic in cellulase research. Trichoderma reesei RUT C30 is known to be one of the best hyper producing cellulolytic fungi, which makes it an ideal test organism for research.
New findings could be adopted for industrial strains in the hope of improving enzyme yields, which in turn may result in lower
market price of cellulases, thus making fuel ethanol more cost competitive with fossil fuels. Being one of the factors affecting
the growth and cellulase production of T. reesei, the pH of cultivation is of major interest. In the present work, numerous pH-controlling strategies were compared both in
shake-flask cultures and in a fermentor. Application of various buffer systems in shake-flask experiments was also tested.
Although application of buffers resulted in slightly lower cellulase activity than that obtained in non-buffered medium, β-glucosidase
production was increased greatly. 相似文献
142.
In an m-cycle system C of order n the blocks are the vertex sets of n(n−1)/(2m) cycles Ci such that each edge of the complete graph Kn belongs to precisely one cycle Ci E C. We prove the existence of m-cycle systems that admit no vertex partition into two classes in such a way that each class meets every cycle of C. The proofs apply both constructive and probabilistic methods, and also some old and new facts about Steiner Triple Systems without large independent sets. © 1996 John Wiley & Sons, Inc. 相似文献
143.
Norbert Szoboszlai Erzsébet Andrási Zsolt Ajtony Ivett Császma 《Mikrochimica acta》2001,137(1-2):81-86
A method is reported for measuring Se and Sn in human brain tissue. The patients from whom the samples were taken had no
diseases in their central nervous system. Microwave energy was applied to digest the brain samples. The digested samples were
analyzed without dilution by transversely heated graphite atomizer for atomic absorption spectrometry with longitudinal Zeeman
background correction. The dependence of integrated absorbance on various chemical modifiers has been examined. The most appropriate
technique proved to be 5 μl sample injection using 20 μg prereduced palladium-nitrate for Se determination, and 20 μl sample
injection applying 10 μg palladium-nitrate + 3 μg magnesium-nitrate for the measurements of Sn. The optimal temperature program
was found to be 1200 °C pyrolysis and 2100 °C atomisation temperature for Se and 1500 °C pyrolysis and 2300 °C atomisation
temperature for Sn. Accuracy of the applied techniques was tested by the analysis of standard reference materials. The precision
was ±5% for Se and ±10% for Sn. The range of recovery values was 85–95% for Se and 95–105% for Sn. The mean Se concentrations
in the investigated brain parts ranged from 200 to 700 ng/g, while the Sn concentrations were between 20 and 300 ng/g dry
weight.
Received October 3, 2000. Revision February 1, 2001. 相似文献
144.
Zsolt Lengvárszky 《Algebra Universalis》1992,29(4):601-603
Presented by R. Freese. 相似文献
145.
Zsolt Keresztessy Magdolna Bodnár Elizabeth Ber István Hajdu Min Zhang John F. Hartmann Tamara Minko János Borbély 《Colloid and polymer science》2009,287(7):759-765
For the purpose of targeted drug delivery, composite biodegradable nanoparticles were prepared from chitosan and the poly-γ-glutamic
acid via an ionotropic gelation process. These stable self-assembled nanoparticles were characterized by dynamic light scattering,
transmission electron microscopy, and atomic force microscopy, which demonstrated that the nanosystem consists of spherical
particles with a smooth surface both in aqueous environment and in dried state. Toxicity measurements showed that the composition
is nontoxic when tested either on cell cultures or in animal feeding experiments. To evaluate the potential of the nanosystem
for intracellular drug delivery, the nanoparticles were fluorescently labeled and folic acid was attached as a cancer cell-specific
targeting moiety. The ability of the particles to be internalized was tested using confocal microscopic imaging on cultured
A2780/AD ovarian cancer cells, which overexpress folate receptors. The quantitative data obtained by digital processing of
the intensity of green color of each pixel in the pictures inside the cell boundaries and total intensity of fluorescence
inside the cells showed that “targeted” particles internalized into the cells significantly faster and the total accumulation
of these particles was substantially higher in the cancer cells when compared with “nontargeted” particles, which may facilitate
effective and specific cytoplasmic delivery of anticancer agents loaded into such nanoparticles.
Zsolt Keresztessy and Magdolna Bodnár contributed equally to this work. 相似文献
146.
A new analogue of the antitumor pericosines possessing a bicyclo[2.2.2]octene skeleton has been synthesized from methyl gallate using oxidative dearomatization and regio- and diastereoselective Diels-Alder reaction as the key steps. 相似文献
147.
We present a class of exact ground states of a three-dimensional periodic Anderson model at 3/4 filling. Hopping and hybridization of d and f electrons extend over the unit cell of a general Bravais lattice. Employing novel composite operators combined with 55 matching conditions the Hamiltonian is cast into positive semidefinite form. A product wave function in position space allows one to identify stability regions of an insulating and a conducting ground state. The metallic phase is a non-Fermi liquid with one dispersing and one flat band. 相似文献
148.
Zsolt Katona 《Graphs and Combinatorics》2005,21(1):71-76
Let f(l, t, n) be the maximal size of a family such that any l2 sets of have an exactly t1-element intersection. If l3, it trivially comes from [8] that the optimal families are trivially intersecting (there is a t-element core contained by all the members of the family). Hence it is easy to determine Let g(l,t,n) be the maximal size of an l-wise exaclty t-intersecting family that is not trivially t-intersecting. We give upper and lower bounds which only meet in the following case: g(3, 1, n) = n2/3(1 + o(1)). 相似文献
149.
A framework (G,p) is a straight line realization of a graph G=(V,E) in , given by a map . We prove that if (G,p) is an infinitesimally rigid framework then there is an infinitesimally rigid framework (G,q) for which the points q(v), vV(G), are distinct points of the k×k grid, where . We also show that such a framework on G can be constructed in O(|V|3) time. 相似文献
150.
The mobility and speciation of Pt was investigated in dust deposited in highway tunnels and in gully sediments. For this, a sequential extraction technique was used in combination with a microwave digestion procedure, followed by detection of Pt with high resolution ICP-MS. A digestion procedure using HNO3/HCl/H2O2
was developed and its efficiency tested for environmental materials. Total Pt contents ranged from approximately 100 to 300 g/kg. The high share of chemically mobile Pt in the tunnel dust (up to about 40%) indicates that Pt is predominantly emitted in a mobile form from the converter. The absence of a mobile fraction in the gully sediment is explained by the elution of Pt by run-off. Except for the mobile and easily mobilised fractions none of the other fractions of the sequential extraction contains Pt, neither in the dust samples nor in the gully sediment. 相似文献