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61.
Recent experimental results for the viscosity of liquid CdTe exhibit disparate behavior as a function of temperature. While some measurements show the expected Arrhenius-type behavior, other measurements show an anomalous temperature dependence indicating an increase in viscosity with increasing temperature. We present ab initio molecular-dynamics simulations of liquid cadmium telluride near its melting point and use the Stokes-Einstein relation to extract values of the viscosity constant. We find no anomalous behavior; the viscosity decreases monotonically with temperature and is consistent with an Arrhenius like behavior. Although calculated values are slightly smaller than those measured, the predicted activation energy agrees well with experiment. 相似文献
62.
Lu XX Tang HS Ko CC Wong JK Zhu N Yam VW 《Chemical communications (Cambridge, England)》2005,(12):1572-1574
The anion-assisted shift of trans-cis isomerization equilibrium of a palladium(II) complex containing acetanilide functionalities brought about by allosteric hydrogen bonding interactions has been established by UV/Vis, 1H NMR, 31P NMR and ESI-MS studies. 相似文献
63.
A method for the determination of cadmium microamounts in mixtures with metallic ions withE
1/2 near toE
1/2 of cadmium is discussed. For higher selectivity cadmium was extracted in the form of the pyridin-thiocyanate complexes prior to polarography.
Bestimmung von Cadmium(II) neben anderen Metallionen
Zusammenfassung Es wird eine polarographische Methode zur Bestimmung von Cd(II) neben anderen Metallionen mitE 1/2 naheE 1/2(Cd) diskutiert. Zur Erhöhung der Selektivität und Genauigkeit wird eine Pyridin-Thiocyanat-Extraktion vorgeschalten.相似文献
64.
Min Gyu Jeong Kai Zhou Soyeon Park HyeongJeon An Yonghoon Kwon Yeonho Chang Do-Hyeon Kim Sung Ho Ryu 《Experimental & molecular medicine》2021,53(2):291
Various repertoires of membrane protein interactions determine cellular responses to diverse environments around cells dynamically in space and time. Current assays, however, have limitations in unraveling these interactions in the physiological states in a living cell due to the lack of capability to probe the transient nature of these interactions on the crowded membrane. Here, we present a simple and robust assay that enables the investigation of transient protein interactions in living cells by using the single-molecule diffusional mobility shift assay (smDIMSA). Utilizing smDIMSA, we uncovered the interaction profile of EGFR with various membrane proteins and demonstrated the promiscuity of these interactions depending on the cancer cell line. The transient interaction profile obtained by smDIMSA will provide critical information to comprehend the crosstalk among various receptors on the plasma membrane.Subject terms: Fluorescence imaging, Super-resolution microscopy, Single-molecule biophysics 相似文献
65.
J. Jung H. S. Jeong H. H. Chung M. J. Lee J. H. Jin K. B. Park 《Journal of Radioanalytical and Nuclear Chemistry》2003,255(3):543-546
The radioactive concentrations of radionuclides were measured in the soil and groundwater below the 12 GeV proton beam-line tunnel at KEK. Various long-lived radionuclides, (7Be, 22Na, 46Sc, 54Mn, 60Co, 134Cs, 152Eu and 154Eu) were observed in the soil samples by -ray spectra measurements, and 3H was also detected by liquid scintillation counting. On the other hand, 3H, 22Na and 54Mn, which were leached from the soil were measured in the groundwater below the EP2 beam line. 3H and 22Na were also found in slight amounts in groundwater collected in a well dug beside the East Counter Hall. From a comparison with the radioactive concentration in soil and groundwater, the order of the leaching percentages were 3H>22Na>54Mn. This tendency was in agreement with an experimental result of the RI laboratory. 相似文献
66.
Photoactivation of pheophorbide a induces a mitochondrial-mediated apoptosis in Jurkat leukaemia cells 总被引:5,自引:0,他引:5
Lee WY Lim DS Ko SH Park YJ Ryu KS Ahn MY Kim YR Lee DW Cho CW 《Journal of photochemistry and photobiology. B, Biology》2004,75(3):119-126
The mechanism of cell death by pheophorbide a (Pba) which has been established to be a potential photosensitizer was examined in experimental photodynamic therapy (PDT) on Jurkat cells, a human lymphoid tumor cell line. In 30-60 min after irradiation, Pba treated cells exhibited apoptotic features including membrane blebbing and DNA fragmentation. Pba/PDT caused a rapid release of cytochrome c from mitochondria into the cytosol. Sequentially, activation of caspase-3 and the cleavage of poly ADP-ribose polymerase (PARP) were followed. Meanwhile, no evidence of activation of caspase-8 was indicated in the cells. In experiments with caspase inhibitors, it was found that caspase-3 alone was sufficient initiator for the Pba-induced apoptosis of the cells. Pba specific emission spectra were confirmed in the mitochondrial fraction and the light irradiation caused a rapid change in its membrane potential. Thus, mitochondria were entailed as the crucial targets for Pba as well as a responsible component for the cytochrome c release to initiate apoptotic pathways. Taken together, it was concluded that the mode of Jurkat cell death by Pba/PDT is an apoptosis, which is initiated by mitochondrial cytochrome c release and caspase-3-pathways. 相似文献
67.
The preparation of an 1,3-alternate calix[4]arene phosphorus ligand, 25,27-bis(2-(diphenylphosphino)ethoxy)-26,28-bis(1-propyloxy)calix[4]arene (3), is presented. Ligand 3 is obtained in three steps in 64% overall yield. Reaction of 3 with [Rh(cot)2]BF4 produced the encapsulated rhodium complex [Rh[(P,P)-diphen-calix[4]arene]]BF4 (4). As revealed by a single-crystal X-ray diffraction study, the rhodium center has a bent coordination environment with a P-Rh-P angle of 135.66(3) degrees. Palladation of 3 employing [Pd(MeCN)4](BF4)2 yielded the chelate palladium complex 7 in which the palladium center has a slightly bent configuration. Treatment of the ligand with Pd(cod)Cl2 and [Pd(eta3-C4H7)(THF)2]BF4 leads to the isolation of the monometallic complex. Full characterization includes X-ray structural studies of compounds 3, 4, and 6. 相似文献
68.
As a new type of foldamers, oligoindoles containing 4, 6, and 8 indole rings were synthesized, and their folding properties were characterized by a combination of 1H NMR techniques and UV/visible titration experiments. When chloride was added, the NH signals of the oligoindoles were downfield shifted as a result of hydrogen-bond formation, and the aromatic signals were upfield shifted by stacking between two indoles. Moreover, the ROESY experiment provided definitive NOE evidence for the helical stacking in the presence of chloride. Finally, the UV/visible titration experiments demonstrated that the oligoindoles formed 1:1 complexes with chloride, and the association constants greatly increased with increasing the number of the indole NHs. These observations are all consistent with the fact that oligoindoles adopt a helical conformation when complexed with chloride by hydrogen-bonding interactions. 相似文献
69.
This paper describes an efficient synthetic route for various types of novel carbocyclic nucleosides. The required stereochemistry of the targeted nucleosides was successfully obtained with use of Grubbs cyclization and Trost allylic alkylation from the carbohydrate chiral template "D-lactose". 相似文献
70.
Conformations of 2-methoxytetrahydropyran as a model for the six-membered ring in aldopyranosides have been calculated by the PCILO method using the algorithm of the conjugated gradient to optimize the geometry. The calculated geometry of the fourteen basic forms of 2-methoxytetrahydropyran was found to be in agreement with the available data obtained by X-ray diffraction of pyranosides. The results indicate differences in the geometry of 2-methoxytetrahydropyran resulting from the change of the axial vs. equatorial position of the methoxyl group. These changes are particularly meaningful in the values of bond angles and they are in agreement with the anomeric and exoanomeric effects. The experimentally found differences in the energies of an axial (4
C
1) and equatorial (1
C
4) conformer, G = 2.9–3.7 kJ/mol, and the dipole moment, = 1.20 ± 0.05 D (1D = 3.33 10–30mAs) agree well with the calculated values E = 3.18 kJ/mol and <> = 1.18 D which, in turn, suggest that the axial conformer is preferred over the equatorial one by a ratio a:e = 78:22. 相似文献