In previous papers we have described methods for accurately measuring the spectra that represent the differences between the oxidized and the reduced forms of the cytochrome components of the turbid heart muscle particles that contain the intact succinic oxidase system (1, 2). In order to extend the pioneer observations of Keilin and Hartree on the carbon monoxide compound of cytochrome a3 (3) ...

Boron complexes of [14]triphyrins(2.1.1) were prepared from free-base [14]triphyrins(2.1.1) with phenylboron dichloride. The absorption spectrum of the meso-free β-alkyl-triphyrin boron complex in CH2Cl2 showed a broad weak band at around 640 nm assigned to transition from B-phenyl to the triphyrin, while that of the meso-aryl benzotriphyrin boron complex showed only Soret and Q bands.

Native and reconstituted myoglobin were prepared and their c.d. spectra recorded in the Soret region. Time-dependent changes in dichroism following reconstitution were observed and related to haem orientational disorder. Comparative c.d. studies, in agreement with n.m.r. studies, reveal that the degree and nature of this disorder are species-dependent.

The circular dichroism spectra of native and recombined vinyl-(protojhematin horseradish peroxidase are identical, which confirms the proper position of the reintroduced group. The same observation and conclusion applies to the light absorption spectra. Circular dichroism and light absorption spectra of seven artificial peroxidases, prepared from apoperoxidase and 2,4substituted hematins, have ...

The absorption spectrum of deoxygenated human hemoglobin differs from that of the isolated a! and /3 chains, and the difference has been ascribed to the conformational changes on which depends the cooperative ligand binding. Studies on hybrid-heme hemoglobins, in which one chain contains protoheme and the other chain mesoheme, showed that the prominent peak in the Soret region of the difference...

We have performed gas-phase absorption spectroscopy in the Soret-band region of chlorophyll (Chl) a and b tagged by quaternary ammonium ions together with time-dependent density functional theory (TD-DFT) calculations. This band is the strongest in the visible region of metalloporphyrins and an important reporter on the microenvironment. The cationic charge tags were tetramethylammonium, tetrab...

Soret band lifetimes of the free-base tetraphenylporphine (H(2)TPP) and Cu(ii) tetraphenylporphine (Cu(II)TPP) at 408 nm have been directly measured with femtosecond (fs) resolution using the fluorescence-upconversion technique for the first time, giving tau = 68 +/- 15 and 63 +/- 15 fs, respectively, in benzene solvent.

New stochastic models of thermodiffusion are constructed and their hydrodynamical limits are studied through a first order Chapman-Enskog expansion. These models differ from earlier ones by taking into account all first order contributions proportional to the temperature gradient and, thus, allow for both positive and negative Soret coefficients, in accordance with observations.

This article looks at the Soret and Dufour effects on the magnetohydrodynamic (MHD) peristaltic flow of variable viscosity fluid in a symmetric channel. Analysis is presented in the presence of Ohmic heating. Results for the stream function, temperature and concentration are constructed. The variations of sundry parameters are analyzed.