摘要:

The effect of cAMP levels on the fluidity of human erythrocytes membrane phospholipid is studied. When the cAMP levels are low, cAMP produces phospholipid molecules less ordered. When the cAMP levels are high, it has the opposite function for the above mentioned part of phospholipid. Generally, cAMP causes the long nonpolar chains in higher gauche configuration fraction. The effects of cAMP levels on the packing of the long nonpolar chain are not very notable. cGMP has the negative function on the membrane phospholipid. ATP has no notable effect on the membrane phospholipid. But cGMP or ATP weakens the function of cAMP and even causes the mixture of cAMP-cGMP or cAMP-ATP having an opposite effect compared to that of pure cAMP.

ISSN:0038-7010    

DOI:10.1080/00387019909349977

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Splitting the double layer into autonomous cells is essential during the photoemission from a metal into a solution. An emitted electron participates in the discharge of the double cell isolated from the other part of the interface. The work function of such an electron decreases by a value which is half of the quantity accepted for a single-particle emission. Comparing the new value with the experimental data shows that the interfacial photocurrent is produced by the secondary electrons which acquire the energy in collisions with the primary ones.

ISSN:0038-7010    

DOI:10.1080/00387019909349978

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Keeping in view the chemotherapeutic value of the sulfa-drugs, two scruff base ligands viz ℴ-vanillin-sulfanilamide (ℴVSaH) and ℴorder-vanillin-sulfamerazine (ℴVSmrzH) and their bipositive, tripositive tetrapositive and uranyl metal complexes have been synthesized and characterized by elemental analysis, IR spectra, thermal analysis, magnetic suceptibility measurements, diffuse reflectance spectra and1H NMR spectra and molar conductance measurements. The disappearance of phenolic proton signal at 12.6 ppm and the upfield shift of azomethine proton rignal (from 8.65 ppm against 8.96 ppm in the ligand) upon complexation indicate the coordination by phenolic oxygen (after deprotonation) and azomethine nitrogen respectively. Zn(II), Th(IV) and UO2(VI). complexes are found to be diamagnetic as expected. The low molar conductance values suggest the non-electrolytic nature of these complexes. The general compositions of there complexes are found to be [M(ℴVSa)2] where M=Cu(II), Ni(II), Zn(II), Co(II), [Nd(ℴVSa)(N03)2(H2O)2] [Th(ℴVSa)(N03)3(H20)] [UO2(ℴVSa)(ℴAc)(H2O)] and [M1(ℴVSmrz)2(H2O)2] where M1=Cu(II), Ni(II), Co(II) and Zn(II) and [UO2(ℴVSmrz)2].

ISSN:0038-7010    

DOI:10.1080/00387019909349979

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The FT infrared spectra of the binuclear copper(II) complex with imidazole and saccharin and of its iminodeuterated analogue at room (RT) and liquid nitrogen temperature (LNT) are recorded. The bands that are mainly due to the NH, ND, CO, SO2and metal-ligand stretchings are assigned. The spectral characteristics are correlated with the available structural data and compared with the corresponding data for other saccharinates and imidazole complexes.

ISSN:0038-7010    

DOI:10.1080/00387019909349980

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A new analytical method using the reagent di-2-pyridyl ketone benzoylhydrazone (DPKBH) as a colorimetric chelating agent for the spectrophotometric determination of Ni(II) in natural water samples wasestablished. This method involves a liquid-liquid extraction and was developed for determination of trace amounts of Ni(II).

ISSN:0038-7010    

DOI:10.1080/00387019909349981

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The use of neutral surfactant polyoxyethylene (9) dodecyl ether (AEO9) and polyoxyethylene (10) hexylphenol ether (TX-10) as an additive to enhance the chemiluminescence of peroxyoxalate reaction using bis(2-butoxycarbonyl-3,4,6-trichlorophenyl) oxalate (BBTPO) and hydrogen peroxide as the energy source in organic media with 9,10-diphenylanthracene as a fluorophore had been investigated. The oxidation of BBTPO in both AEO9 and TX-10 inverted micelles produced significantly improved intensity and efficiency of the chemiluminescence relative to that in normal organic media. It was found that in AEO9 and TX-10 inverted micellar media the enhancement of chemiluminescence was mainly due to the improvement of the reaction excitation efficiencies, but only slightly contributed by the increase of the fluorescence efficiency.

ISSN:0038-7010    

DOI:10.1080/00387019909349982

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Chemisorption and conformation of ω-mercaptoalkanols (HO(CH2)nSH, n=2, 6, 10) on silver mirror and HNO3etched silver foils have been observed by Fourier transform Surface Enhanced Raman Scattering spectroscopy (FT-SERS). The conformations of these adsorbates were affected by molecular chain length and surface roughness. In the adsorption state most of adsorbates inclined to be in trans conformation and ratio of trans to gauche conformation increased with the chain length.

ISSN:0038-7010    

DOI:10.1080/00387019909349983

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

In this work we have studied the hydrolysis of titanium tetrabutoxide (TTB) in butyl alcohol. The hydrolysis was carried out by adding H2O for a molar ratio water/alkoxide of 4. The hydrolysis has been followed by FT-IR spectroscopy, and the evolution of the Ti-O-C bands of the TTB molecule have been analysed. These bands are located at 1130, 1100 and 1039 cm−1and their intensities decrease with the hydrolysis time. However, these bands do not disappear for several days of hydrolysis confirming the difficulty to obtain a completely hydrolysed TTB molecule. Two IR bands have been assigned to Ti-OH groups and adsorbed H2O molecules. These bands appear at 3660 and 3525 cm−1respectively and they are firstly observed when a white precipitate appears in the solution. This work shows that this study can be rapidly carried out by FT-IR spectroscopy and can also be applied to the well-established sol-gel process.

ISSN:0038-7010    

DOI:10.1080/00387019909349984

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The alkaline isomer of horse heart ferricytochromecin the presence of γ-picoline (γ-MePy) is studied using1H NMR methods. We find that the lysine form of cytcoccurs at neutral pH environment in the presence of γ-MePy and increasing [γ-MePy] facilitates the transition from the native to the alkaline forms and stabilizes one of the two alkaline forms of cytc.The conformational changes in cyt c induced by temperature are similar with that induced by [γ-MePy]. The kinetic behavior for the formation of the two alkaline isomers have changed in the presence of even small amounts of γ-MePy. It is indicated that the presence of γ-MePy stabilize Lys72 or 73 binding form and inhibit the formation of Lys79 binding alkaline isomer.

ISSN:0038-7010    

DOI:10.1080/00387019909349985

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

New cationic Fe(III),Co(II) and Ni(II) mixed ligand complexes containing both triphenylphosphine and isatin ligands were prepared and characterized using conventional physical and chemical methods of analysis

ISSN:0038-7010    

DOI:10.1080/00387019909349986

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor