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1.
Blanka Wladislaw Liliana Marzorati Jonas Gruber 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):185-188
Abstract Some new norbornene thioester derivatives of endo configuration are sinthesized. Proofs are provided that thioester group has more preference for endo configuration than the ester group. 相似文献
2.
Claudio L. Donnici Elaine Henriques Teixeira Pereira Júlio C. Dias Lopes Liliana Marzorati Blanka Wladislaw 《合成通讯》2013,43(3):342-350
The study on reactivity of several α-substituted α-sulfonyl malonates toward 1,4-diazabicyclo[2.2.2]octane (DABCO) and Bu3N is described. The reactivity with DABCO revealed the possible competition between decarbalkoxylation and unexpected desulfonylation, depending on the α-substituent, because of sterical hindrance around the electrophilic centers (SO2 and CO2R). The derivatives with crowded α-substituents suffer selective desulfonylation, and a novel and efficient desulfonylation method can be proposed. The dependence of the reactivity of α-sulfonyl malonates on the sterical hindrance around the electrophilic centers is confirmed by conformational analysis (Macromodel/MM2? and Mopac/MP3). The carbanionic mechanism is proved because the corresponding protonated, deuterated, and sulfenylated products were obtained by addition of the corresponding electrophilic agents. Bu3N showed itself to be a novel selective decarbalkoxylation agent for any α-substituted α-sulfonyl malonate. 相似文献
3.
Petr Tůma Martin Jaček Blanka Sommerová Pavel Dlouhý Radka Jarošíková Jitka Husáková Veronika Wosková Vladimíra Fejfarová 《Electrophoresis》2022,43(11):1129-1139
Determination of the broad-spectrum antibiotics amoxicilline (AMX) and ceftazidime (CTZ) in blood serum and microdialysates of the subcutaneous tissue of the lower limbs is performed using CE with contactless conductivity detection (C4D). Baseline separation of AMX is achieved in 0.5 M acetic acid as the background electrolyte and separation of CTZ in 3.2 M acetic acid with addition of 13% v/v methanol. The CE-C4D determination is performed in a 25 µm capillary with suppression of the EOF using INST-coating on an effective length of 18 cm and the attained migration time is 4.2 min for AMX and 4.4 min for CTZ. The analysis was performed using 20 µl of serum and 15 µl of microdialysate, treated by the addition of acetonitrile in a ratio of 1/3 v/v and the sample is injected into the capillary using the large volume sample stacking technique. The LOQ attained in the microdialysate is 148 ng/ml for AMX and 339 ng/ml for CTZ, and in serum 143 ng/ml for AMX and 318 ng/ml for CTZ. The CE-C4D method is employed for monitoring the passage of AMX and CTZ from the blood circulatory system into the subcutaneous tissue at the sites of diabetic ulceration in patients suffering from diabetic foot syndrome and also for measuring the pharmacokinetics following intravenous application of bolus antibiotic doses. 相似文献
4.
Monovacancy diffusion alone dominates over diffusion due to divacancies and interstitials in Al for all temperatures up to the melting point. Deviations from a single Arrhenius dependence are due to anharmonicity. The conclusion is based on a combination of theoretical methods, from density functional theory to thermodynamic integration, without fitting to experimental data. The calculated diffusion rate agrees with experimental data over 11 orders of magnitude. 相似文献
5.
A.?P.?Voitovich O.?V.?GoncharovaEmail author V.?S.?Kalinov 《Journal of Applied Spectroscopy》2005,72(3):301-305
As a result of studying thin-film nano-sized media, it is shown that the extended surface exerts a substantial influence on
their distinctive properties. It has been established that, by using special methods to obtain nano-sized media under certain
conditions, it is possible to form crystal structures with a high concentration of defects of a prescribed type in the near-surface
layers of nanocrystals. The correlations found between the conducting and optical properties of thin-film nano-sized structures
are an additional factor that extends the capabilities of controlling their characteristics with a view toward developing
miniature effective radiation sources, elements of modulation of laser radiation, dosimeters, and components of thin-film
solar cells.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 3, pp. 287–291, May–June, 2005. 相似文献
6.
I. F. Voloshin A. V. Kalinov L. M. Fisher V. A. Yampol’skiĭ 《Journal of Experimental and Theoretical Physics》2007,105(1):278-282
The evolution of the spatial distribution of the magnetic induction in a superconductor after the action of the alternating magnetic field perpendicular to the trapped magnetic flux has been analyzed. The observed stabilization of the magnetic induction profile is attributed to the increase in the pinning force, so that the screening current density becomes subcritical. The last statement is corroborated by direct measurements. 相似文献
7.
8.
Michal Korenko Marián Kucharík Jozef Vincenc Oboňa Dušan Janičkovič Rosa Córdoba José María De Teresa Blanka Kubíková 《Helvetica chimica acta》2008,91(7):1389-1399
The rapid‐solidification processing (by a cooling rate of 105–106 K/s) was used for the preparation of deeply undercooled cryolite/alumina (Na3AlF6/Al2O3) melts. We found a mass of nanotubes on the surface of these undercooled melts. The nanotubes were preferentially located on the defect places of the surface with the following approximate dimensions: base≈100×100 nm, length≈1000 nm. The solidified samples with the nanotubes on the surface were analyzed by scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX), X‐ray diffraction (XRD), and infrared spectroscopy (IR). 相似文献
9.
estmír ejka Jan Pláteník Richard Buchal Vilém Guryca Jakub irc Martin Vejraka Jiina Crkovská Taras Ardan Jií Michálek Blanka Brnová Jitka ejková 《Photochemistry and photobiology》2009,85(3):794-800
The aim of the present paper was to examine the irradiation effect of two doses of UVA rays (365 nm) on the rabbit cornea and lens. Corneas of anesthetized adult albino rabbits were irradiated with UVA rays for 5 days (daily dose 1.01 J cm−2 in one group of rabbits and daily dose 2.02 J cm−2 in the second group of animals). The third day after the last irradiation, the rabbits were killed, and their eyes were employed for spectrophotometrical, biochemical and immunohistochemical investigations. Normal eyes served as controls. Absorption spectra of the whole corneal centers were recorded over the UV–VIS (visible) spectral range. Levels of antioxidant and prooxidant enzymes, nitric oxide synthases and nitric oxide (indirectly measured as nitrate concentration) were investigated in the cornea. Malondialdehyde, a byproduct of lipid peroxidation, was examined in the cornea and lens. The results show that the staining for endothelial nitric oxide synthase was more pronounced in corneas irradiated with the higher UVA dose. Otherwise, UVA rays at either dose did not significantly change corneal light absorption properties and did not cause statistically significant metabolic changes in the cornea or lens. In conclusion, UVA rays at the employed doses did not evoke harmful effects in the cornea or lens. 相似文献
10.
S. A. Mikhnov V. S. Kalinov O. M. Komar S. I. Ovseichuk 《Journal of Applied Spectroscopy》1990,53(4):1048-1052
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 53, No. 4, pp. 584–589, October, 1990. 相似文献