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61.
Enrique J. Baran 《Monatshefte für Chemie / Chemical Monthly》1991,122(6-7):479-481
Summary Mean amplitudes of vibration for OTeF
5
–
have been calculated from known spectroscopic and structural data in a wide temperature range. The results are briefly discussed in comparison with those of related species. 相似文献
62.
Jolanta Baran Andrzej Duda Adam Kowalski Ryszard Szymanski Stanislaw Penczek 《Macromolecular Symposia》1997,123(1):93-101
Chain transfer processes (ktr) taking place in the polymerization (anionic and pseudoanionic) of cyclic esters (lactones) are reviewed. These reactions are mostly responsible for the departure of these systems from the fully controlled (living) polymerizations. The ratios of kp/ktr have been determined for a number of initiating systems and the structures of the growing species are related to their selectivity, expressed by kp/ktr. It has been shown that the less reactive and more sterically crowded active species polymerize more selectively. 相似文献
63.
Neslihan Tekin Kamile Öztürk Talat Baran Barış Kerimoğlu Mehtap Tarhan Ayfer Menteş 《高分子科学杂志,A辑:纯化学与应用化学》2017,54(5):263-270
In the investigation for alternative chemotherapeutic strategies against leukemia, Pd(II) complexes were synthesized and investigated for cytotoxic and apoptotic properties on two human leukemia cell lines (HL-60 and K562). Pd(II) complexes (Pd-5a and Pd-6a) with 5a and 6a as ligands were synthesized and characterized by 1H-NMR and F-TIR. The cytotoxicity of the compounds was quantified using MTT method. Bax, Bcl-2, and caspase 3 gene expression levels were estimated using RT-qPCR. Here we show that Pd(II) complexes have important cytotoxic activity on human leukemia cell lines. RT-qPCR indicated that Bax and caspase 3 gene expression levels were increased after 24 h treatment with Pd-5a and Pd-6a complexes in both HL-60 and K562 cells at some selected dose. Furthermore, Bcl-2 gene expression level decreased after 24 h treatment with Pd-5a and Pd-6a complexes in K562 cells at all selected dose. In HL-60 cells, only one selected Pd-5a dose (25 µM) decreased the gene expression level of Bcl-2. The results obtained in the present investigation indicate that these two newly synthesized Pd(II) complexes have apoptotic effects at appropriate doses through caspase 3 and Bax genes and might represent a novel potentially active agents for the management of human leukemia cell lines. 相似文献
64.
Dr. Tian Qin Dr. Lara R. Malins Jacob T. Edwards Rohan R. Merchant Alexander J. E. Novak Jacob Z. Zhong Riley B. Mills Ming Yan Dr. Changxia Yuan Dr. Martin D. Eastgate Prof. Phil S. Baran 《Angewandte Chemie (International ed. in English)》2017,56(1):260-265
Two named reactions of fundamental importance and paramount utility in organic synthesis have been reinvestigated, the Barton decarboxylation and Giese radical conjugate addition. N ‐hydroxyphthalimide (NHPI) based redox‐active esters were found to be convenient starting materials for simple, thermal, Ni‐catalyzed radical formation and subsequent trapping with either a hydrogen atom source (PhSiH3) or an electron‐deficient olefin. These reactions feature operational simplicity, inexpensive reagents, and enhanced scope as evidenced by examples in the realm of peptide chemistry. 相似文献
65.
J. Baran A. J. Barnes M. K. Marchewka A. Pietraszko H. Ratajczak 《Journal of Molecular Structure》1997,416(1-3):33-42
The crystal structure of bis(betaine)-selenic acid has been determined by X-ray diffraction as orthorhombic, space group Pbca, with a = 11.591(2), b = 22.930(5), c = 12.045(2) Å and Z = 8. The crystal comprises hydrogen selenate ions, HSeO−4, and two distinct betaine molecules, which are held together into a complex by short hydrogen bonds. One of the betaine molecules is present as the zwitterion form (CH3)3N+---CH2---COO− and the second occurs as the protonated form (CH3)3N+---CH2---COOH. Powder FTIR and Raman spectra were measured. An assignment of the observed bands to vibrations of the hydrogen bonds and internal vibrations of the hydrogen selenate ion and the betaine molecules is proposed. 相似文献
66.
M. Baran 《Acta Mathematica Hungarica》2000,87(1-2):33-45
We define two closure operators of some well-known topological categories and investigate the relationships between these
closure operators and the one that is given in [9]. As a consequence, we characterize separation properties T
0, T
1, and T
2 for these well-known categories and compare them with the ones that are given in [3] and [6]. Finally, we characterize the
epimorphisms in the subcategories of these given categories.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
67.
Burcu Baran 《Archiv der Mathematik》2010,94(1):11-18
Let p be a prime number and G be a finite commutative group such that p
2 does not divide the order of G. In this note we prove that for every finite module M over the group ring Z
p
[G], the inequality #M £ #Zp[G]/FitZp[G](M){\#M\,\leq\,\#{\bf Z}_{p}[G]/{{\rm Fit}}_{{\bf Z}_{p}[G]}(M)} holds. Here, FitZp[G](M){\rm Fit}_{{\bf Z}_{p}[G]}(M) is the Z
p
[G]-Fitting ideal of M. 相似文献
68.
M. Baran 《Acta Mathematica Hungarica》1998,80(3):211-224
In this paper, various generalizations of the usual completely regular spaces and completely normal spaces to topological categories are given. Moreover, the relationships among various forms of these generalizations are investigated. 相似文献
69.
V.V. Nosenko I.P. Vorona S.S. Ishchenko N.P. Baran I.V. Zatovsky N.A. Gorodilova V.Yu. Povarchuk 《Radiation measurements》2012,47(10):970-973
Effect of pre-annealing of synthetic hydroxyapatite (HAP) on properties of γ- and UV- induced NO32- centers was studied by electron paramagnetic resonance (EPR). Nitrate-containing hydroxyapatite powders ((N)HAP)) and the powders with an admixture of carbonate and nitrate ions ((C,N)HAP) were annealed in the temperature range Tann = 20 °C ? 600 °C before irradiation. It was found that pre-annealing of (N)HAP samples changes the parameters of NO32- centers while no changes took place in (C,N)HAP. Moreover, at the pre-annealing temperatures Tann > 200 °C two new NO32- centers were observed in (N)HAP samples; they are characterized by larger value of A⊥ (3.67 and 4.41 mT) as compared to the known centers. It was also found that the dependence of NO32- centers amount on Tann is non-monotonous in both types of samples. Presumably this is caused by the escape of water molecules from HAP during the annealing and essential modification of the defect subsystem of HAP. 相似文献
70.
N. V. Gaponenko A. V. Mudryi O. V. Sergeev M. Stepikhova L. Palmetshofer W. Jantsch J. C. Pivin B. Hamilton A. S. Baran A. I. Rat''ko 《Journal of luminescence》1998,80(1-4):399-403
Sol–gel derived Fe2O3 films containing about 10 wt% of Er2O3 were deposited on porous silicon by dipping or by a spin-on technique followed by thermal processing at 1073 K for 15 min. The samples were characterized by means of PL, SEM and X-ray diffraction analyses. They exhibit strong room-temperature luminescence at 1.5 μm related to erbium in the sol–gel derived host. The luminescence intensity increases by a factor of 1000 when the samples are cooled from 300 to 4.2 K. After complete removal of the erbium-doped film by etching and partial etching the porous silicon, the erbium-related luminescence disappears. Following this, luminescence at 1.5 μm originating from optically active dislocations (“D-lines”) in porous silicon was detected. The influence of the conditions of synthesis on luminescence at 1.5 μm is discussed. 相似文献