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1.
O. K. Krasil’nikova A. M. Voloshchuk A. E. Evsyukhin N. Y. Lomovskaya 《Colloid Journal》2006,68(2):182-188
The new template procedure for preparing ultramicro-, micro-, and supermicroporous carbon adsorbents is proposed on the basis
of the use of two polymers with different thermal stabilities as a template matrix and a carbonizable carbon source. The polymeric
template matrix is removed by thermal decomposition in the low-temperature pyrolysis of the polymer mixture, whereas the second
polymer component of a mixture is transformed into a carbonizate. The resultant monolithic carbonizate is the polymeric matrix
replica and represents a molecular-sieve ultramicroporous carbon adsorbent, which adsorbs water vapor at 293 K and does not
adsorb nitrogen vapor at 77 K. The activation of this carbonizate with water vapor leads to a series of micro-and supermicroporous
carbon adsorbents with a broad range of the parameters of a pore structure: BET specific surface area S
BET is 610–2130 m2/g, micropore volume W
0 is 0.20–0.69 cm3/g, micropore half-width x
0 (slit model) is 0.20–0.70 nm, mesopore specific area S
me is 20–1000 m2/g, and characteristic adsorption energy E
0 is 15.6–27.4 kJ/mol.
Original Russian Text ? O.K. Krasil’nikova, A.M. Voloshchuk, A.E. Evsyukhin, N.Y. Lomovsakaya, 2006, published in Kolloidnyi
Zhurnal, 2006, Vol. 68, No. 2, pp. 207–213. 相似文献
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A procedure for the quantitative characterization of complex stressed states and their effect on the relaxation properties of polymer materials has been proposed. Throughout the temperature interval where the thermal degradation of polymers can be ignored, three measurements runs for recording internal friction spectra Δ(T) are performed. As has been shown for cellulose diacetate and poly(vinylformals), a difference between attenuation decrements Δ1(T)–Δ2(T) for the initial samples and the same samples in the second measurement cycle reflects the presence of cryptoheterogeneity. This difference achieves its maximum values at temperatures close to the glass transition temperature T α but becomes noticeable even at temperatures several tens of degrees lower than T α. 相似文献
4.
Carlos Olano Natalia Lomovskaya Leonid Fonstein Jon T Roll C Richard Hutchinson 《Chemistry & biology》1999,6(12):845
Background: The biological activity of many microbial products requires the presence of one or more deoxysugar molecules attached to agylcone. This is especially prevalent among polyketides and is an important reason that the antitumor anthracycline antibiotics are avid DNA-binding drugs. The ability to make different deoxyaminosugars and attach them to the same or different aglycones in vivo would facilitate the synthesis of new anthracyclines and the quest for antitumor drugs. This is feasible using the numerous bacterial genes for deoxysugar biosynthesis that are now available. Results: Production of thymidine diphospho (TDP)-
-daunosamine (dnm), the aminodeoxysugar present in the anthracycline antitumor drugs daunorubicin (DNR) and doxorubicin (DXR), and its attachment to -rhodomycinone to generate rhodomycin D has been achieved by bioconversion with a strain of Streptomyces lividans that bears two plasmids. One contained the Streptomyces peucetius dnmJVUZTQS genes plus dnmW (previously named dpsH and considered to be a polyketide cyclase gene), dnrH, which is not required for the formation of rhodomycin D, and dnrl, a regulatory gene required for expression of the dnm and drr genes. The other plasmid had genes encoding glucose-1-phosphate thymidylyltransferase and TDP-glucose-4,6-dehydratase (dnmL and dnmM, respectively, or mtmDE, their homologs from Streptomyces agrillaceus) plus the drrAB DNR/DXR resistance genes. Conclusions: The high-yielding glycosylation of the aromatic polyketide -rhodomycinone using plasmid-borne deoxysugar biosynthesis genes proves that the minimal information for
-daunosamine biosynthesis and attachment in the heterologous host is encoded by the dnmLMJVUTS genes. This is a general approach to making both known and new glycosides of anthracyclines, several of which have medically important antitumor activity. 相似文献
5.
Stereochemical elucidation and total synthesis of dihydropacidamycin D, a semisynthetic pacidamycin.
C G Boojamra R C Lemoine J C Lee R Léger K A Stein N G Vernier A Magon O Lomovskaya P K Martin S Chamberland M D Lee S J Hecker V J Lee 《Journal of the American Chemical Society》2001,123(5):870-874
Hydrogenation of the C(4') exocyclic olefin of the pacidamycins has been shown to produce a series of semisynthetic compounds, the dihydropacidamycins, with antimicrobial activity similar to that of the natural products. Elucidation of stereochemistry in the pacidamycins has been completed through a campaign of natural product degradation experiments in combination with the total synthesis of the lowest-molecular weight dihydropacidamycin, dihydropacidamycin D. The stereochemical identities of the tryptophan and two alanine residues contained in pacidamycin D have been shown to be of the natural (S) configuration, and the unique 3-methylamino-2-aminobutyric acid contained in this series of antibiotics has been shown to be of the (2S,3S) configuration. Finally, the stereochemistry obtained by hydrogenation of the C(4')-C(5') exocyclic olefin has been shown to be (R) at the C(4') nucleoside site. 相似文献
6.
Lomovskoy V. A. Abaturova N. A. Lomovskaya N. Yu. Khlebnikova O. A. 《Mechanics of Composite Materials》2019,54(6):815-820
Mechanics of Composite Materials - The spectra of internal friction and temperature variation in the frequency of free damped torsional vibrations excited in a polyvinyl alcohol (PVA) sample in the... 相似文献
7.
Lomovskoi V. A. Abaturova N. A. Lomovskaya N. Yu. Galushko T. B. 《Colloid Journal》2022,84(3):297-303
Colloid Journal - The dissipative α-relaxation process in poly(vinyl alcohol) (PVA) films and in a supramolecular composite structure resulting from the formation of ordered regions in a... 相似文献
8.
BACKGROUND: The biological activity of many microbial products requires the presence of one or more deoxysugar molecules attached to agylcone. This is especially prevalent among polyketides and is an important reason that the antitumor anthracycline antibiotics are avid DNA-binding drugs. The ability to make different deoxyaminosugars and attach them to the same or different aglycones in vivo would facilitate the synthesis of new anthracyclines and the quest for antitumor drugs. This is feasible using the numerous bacterial genes for deoxysugar biosynthesis that are now available. RESULTS: Production of thymidine diphospho (TDP)-L-daunosamine (dnm), the aminodeoxysugar present in the anthracycline antitumor drugs daunorubicin (DNR) and doxorubicin (DXR), and its attachment to epsilon-rhodomycinone to generate rhodomycin D has been achieved by bioconversion with a strain of Streptomyces lividans that bears two plasmids. One contained the Streptomyces peucetius dnmJVUZTQS genes plus dnmW (previously named dpsH and considered to be a polyketide cyclase gene), dnrH, which is not required for the formation of rhodomycin D, and dnrI, a regulatory gene required for expression of the dnm and drr genes. The other plasmid had genes encoding glucose-1-phosphate thymidylyltransferase and TDP-glucose-4,6-dehydratase (dnmL and dnmM, respectively, or mtmDE, their homologs from Streptomyces agrillaceus) plus the drrAB DNR/DXR resistance genes. CONCLUSIONS: The high-yielding glycosylation of the aromatic polyketide epsilon-rhodomycinone using plasmid-borne deoxysugar biosynthesis genes proves that the minimal information for L-daunosamine biosynthesis and attachment in the heterologous host is encoded by the dnmLMJVUTS genes. This is a general approach to making both known and new glycosides of anthracyclines, several of which have medically important antitumor activity. 相似文献
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V. A. Lomovoskoi N. A. Abaturova N. Yu. Lomovskaya O. A. Khlebnikova T. B. Galushko 《Polymer Science Series A》2018,60(3):284-289
A comparative analysis of relaxation transitions observed in the internal friction spectra of poly(vinyl alcohol) and poly(vinyl formal) synthesized on its basis is presented. Two distinct peaks (α and β) of dissipative losses are revealed within the temperature range from–150 to +120°C. The time of acetylation of poly(vinyl alcohol) in the production of poly(vinyl formal) affects the characteristics of relaxation phenomena in poly(vinyl formal). A structural justification of change in the relaxation characteristics in poly(vinyl formal) is given according to the internal friction spectra and IR spectra. 相似文献