排序方式: 共有61条查询结果,搜索用时 46 毫秒
1.
Alex Berlin Neil Gilkes Douglas Kilburn Vera Maximenko Renata Bura Alexander Markov Anton Skomarovsky Alexander Gusakov Arkady Sinitsyn Oleg Okunev Irina Solovieva John N. Saddler 《Applied biochemistry and biotechnology》2006,130(1-3):528-545
Seven cellulase preparations from Penicillium and Trichoderma spp. were evaluated for their ability to hydrolyze the cellulose fraction of hardwoods (yellow poplar and red maple) pretreated by organosolv extraction, as well as model cellulosic substrates such as filter paper. There was no significant correlation among hydrolytic performance on pretreated hardwood, based on glucose release, and filter paper activity. However, performance on pretreated hardwood showed significant correlations to the levels of endogenous β-glucosidase and xylanase activities in the cellulase preparation. Accordingly, differences in performance were reduced or eliminated following supplementation with a crude β-glucosidase preparation containing both activities. These results complement a previous investigation using softwoods pretreated by either organosolv extraction or steam explosion. Cellulase preparations that performed best on hardwood also showed superior performance on the softwood substrates. 相似文献
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Patient L Berry MB Coles SJ Hursthouse MB Kilburn JD 《Chemical communications (Cambridge, England)》2003,(20):2552-2553
Silylated methylenecyclopropyl hydrazones on treatment with BF3 x Et2O cyclise to give heterocyclic products involving a novel sequence of hydride and silyl shifts via a series of increasingly stable cationic intermediates. 相似文献
4.
Samarium(II) diiodide mediated intramolecular cyclisation of mixed enone-enoate substrates in THF/MeOH is described. Spirocyclic ethers are obtained, and the stereodefined preparation of 1-oxaspiro[4.4]nonan-7-one products is included. 相似文献
5.
D. Kilburn D. Bamford G. Dlubek J. Pionteck M. A. Alam 《Journal of Polymer Science.Polymer Physics》2003,41(23):3089-3093
The temperature dependence of the mean size of local free volumes in an amorphous atactic (aPP) and a semicrystalline syndiotactic polypropylene (sPP), and an amorphous ethylene‐propylene copolymer (E‐co‐P48) has been studied. Pressure‐volume‐temperature (PVT) experiments were performed for aPP, from which the hole fraction h of the Simha‐Somcynsky theory and the number density of holes were estimated. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 3089–3093, 2003 相似文献
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Lewis acid-mediated intermolecular addition of silylated methylenecyclopropane to aldehydes provides a novel route to tetrahydrofuran derivatives. 相似文献
7.
Arwa Kurabi Alex Berlin Neil Gilkes Douglas Kilburn Renata Bura Jamie Robinson Aleksandr Markov Anton Skomarovsky Aleksandr Gusakov Oleg Okunev Arkady Sinitsyn David Gregg Dan Xie John Saddler 《Applied biochemistry and biotechnology》2005,121(1-3):219-230
Softwood residues are the most abundant feedstock available for bioconversion in many northern countries. However, the high costs for delignification and enzymatic hydrolysis currently deter commercialization of softwood bioconversion processes. This study evaluates the abilities of two novel fungal preparations (MSUBC1 and MSUBC2) and two commercial cellulase preparations (TR1 and TR2) to hydrolyze cellulose in Douglas-fir pretreated by steam explosion or ethanol organosolv process. MSUBC1 showed significantly better performance than the other preparations on both lignocellulosic substrates. In particular, MSUBC1 achieved >76% cellulose conversion for hydrolysis of steam-exploded Douglas-fir (~44% lignin) after 72 h at low enzyme loading (10 filter paper units/g of cellulose) and without β-glucosidase supplementation. 相似文献
8.
CM Thaker S Rayaprol Krushna Mavani DS Rana MS Sahasrabudhe SI Patil DG Kuberkar 《Pramana》2002,58(5-6):1035-1039
The effect of simultaneous substitution of a fluctuating cation and a divalent cation in LaMnO3 perovskite modifies the properties of the material to exhibit large valence colossal magnetoresistance (CMR) effect. A good
example of these properties is (La1−2x
Pr
x
Ca
x
)MnO3 (LPCMO) type CMR material. In this communication it is reported that, with the increase in x (for x=0.1, 0.15, 0.2), the T
c varies between 100 and 120 K with improvisation in metal-insulator transition. Interestingly, resistance increases with x from few hundred ohms to few kilo ohms with corresponding decrease in the unit cell volume. The results of the studies using
X-ray diffraction (XRD), electrical resistivity, magnetoresistance and ac susceptibility measurements on LPCMO samples for
understanding the structural, transport and magnetic properties are discussed in detail. 相似文献
9.
Bartoli S Mahmood T Malik A Dixon S Kilburn JD 《Organic & biomolecular chemistry》2008,6(13):2340-2345
A chiral bisguanidinium macrocycle binds N-Boc-L-glutamate in a 1 : 1 stoichiometry with significant selectivity in competitive solvent (DMSO-H(2)O). 相似文献
10.
Mohamed A. Ghanem Jean-Mathieu Chrtien Jeremy D. Kilburn Philip N. Bartlett 《Bioelectrochemistry (Amsterdam, Netherlands)》2009,76(1-2):115
We report the preparation, using electrochemical and solid-phase synthesis, and characterisation of a 26 member library of 13 dihydroxybenzene derivatives covalently attached to glassy carbon through ethylenediamine (EDA) and C6H4CH2NH linkers. First, Boc-protected EDA or Boc–NHCH2C6H4 were electrochemically attached to the GC surface. After Boc-deprotection, dimethoxybenzoyl chlorides were coupled to the EDA and C6H4CH2NH linkers using solid-phase synthesis followed by deprotection of the methoxy groups to give the corresponding dihydroxybenzene compounds. Surface coverage and electrochemical parameters of the dihydroxybenzene modified electrodes were evaluated in parallel using cyclic voltammetry. The mid-peak potentials, Emp, and surface coverages for the 13 dihydroxybenzene derivatives were found to be independent of the choice of linker. The mid-peak potentials of the immobilised dihydroxybenzene derivatives varied between 0.0 and 260 mV vs. SCE and their surface coverages varied between 0.07 and 1.1 nmol cm− 2, depending on the pattern of substitution of the dihydroxybenzene ring. The electrocatalytic activities of the library were evaluated for mediation of NADH oxidation, and the ortho-dihydroxybenzene derivatives were found to have higher catalytic activity. 相似文献