Study of the ‘Raman spectroscopic signature of life’ in mitochondria isolated from budding yeast

The ‘Raman spectroscopic signature of life’ is a Raman band at 1602 cm⁻¹ that sharply reflects the metabolic activity of cell mitochondria. Here we report the study of thissignature in isolated yeast mitochondria. The existence and behaviour of the 1602 cm⁻¹ band in isolated mitochondria have been confirmed to be the same as in living yeast cells: the intensity of the band decreases with timewhen a respiration inhibitor, sodium azide, is added. The present study shows the significance of isolated mitochondria in elucidating the origin of this still unassigned Raman band. Copyright © 2009 John Wiley & Sons, Ltd.     

In vitro studies of Photofrin® mediated photodynamic therapy on human rhabdomyosarcoma cell line (RD)

In the current study, the cytotoxic effects induced by the given photosensitizer (PS) on human rhybdomyosarcoma cancer cells (RD) as an experimental model were investigated. The experimental results like cytotoxic effects induced by the given PS on RD cells were dose dependent and the optimum concentration of Photofrin® (100 μg/ml) along with 120 J/cm² generates the maximum loss in cell viability which is almost 82%. The significant loss in cell viability is the result of interaction of suitable dose of laser light (630 nm of wavelength) with Photofrin®, after excitation of PS, production of reactive oxygen species (ROS), which leads to mitochondria damage and resulting of cell death (cell necrosis/cell apoptosis). Viability of controlled and treated RD cells with optimum dose of light (630 nm) has been assessed by neutral red assay (NRA) and cell damaging effect were verified by staining of mitochondria using Mitotracker® red as an efficient dye as well as reactive oxygen species (ROS) accumulation detection.     

Light Scattering Changes in Isolated Brain Mitochondria during Anoxia - Magnesium Effect on Morphological Changes and Respiration -

Under pathological conditions, morphological changes of the cells and tissues may differ from those of normal conditions, which can be reflected by changes in light scattering (LS). Consequently, LS has been recognized as a potential non-invasive tool for optical diagnosis of living tissue. This paper aimed to identify the basic properties of LS of isolated brain mitochondria in vitro under normoxic and anoxic conditions in the presence and absence of Mg²⁺. An increase in LS was observed during anoxia in both the presence and absence of Mg²⁺. In both cases, the changes in LS initiated by anoxia and reoxygenation started concomitantly with the reduction of heme aa₃. The rates of LS changes were slower than those of heme aa₃, particularly in the presence of Mg²⁺. Mg²⁺ inhibited the morphological responses of mitochondria caused by the addition of ADP and ATP, and significantly reduced the oxygen consumption rate in state 4. These results are due to modulation of the K⁺/H⁺ antiporter affected by Mg²⁺. In addition, the mitochondria were well coupled, although the basal level of LS fell after addition of Mg²⁺. Therefore, the observed responses of mitochondria at anoxia were physiological and independent of the presence or absence of Mg²⁺. The relationship between LS and redox state of cytochrome c oxidase, an anoxic indicator, provides a basis to assess the tissue conditions in vivo.     

Interaction of fisetin with human serum albumin by fluorescence, circular dichroism spectroscopy and DFT calculations: binding parameters and conformational changes

The interaction between fisetin, an antioxidant and neuroprotective flavonoid, and human serum albumin (HSA) is investigated by means of fluorescence (steady-state, synchronous, time-resolved) and circular dichroism (CD) spectroscopy. The formation of a 1:1 complex with a constant of about 10⁵ M⁻¹ was evidenced. Förster's resonance energy transfer and competitive binding with site markers warfarin and ibuprofen were considered and discussed. Changes in the CD band of HSA indicate a decrease in the α-helix content upon binding. An induced CD signal for bound fisetin was observed and rationalized in terms of density functional theory calculations.     

Fluorometric Detection of Adenosine Triphosphate with 3-Hydroxy-4′-(dimethylamino)flavone in Aqueous Solutions

An effect of appearance of new band in the excitation spectra of 3-hydroxy-4′-(dimethylamino)flavone (FME probe) in presence of adenosine triphosphate (ATP) is described. Considerable shift of new band up to the red and increase of fluorescence intensity points to the formation of FME-ATP associate, in which FME molecule undergoes to a strong electrostatic stabilization by tetra-charged ATP anion. It is shown the FME anion formation is possible under influence of ATP in the studied conditions. The dynamics of the observed effect is studied in mitochondria. The registered phenomenon allows the quantitative evaluation of ATP concentration in the range of 10⁻³–10⁻⁵ M. In contrast to ATP, other nucleoside phosphates do not give a new band in the excitation spectra of FME probe. This implies the possibility of the in vivo determination of the ATP concentration.     

Superdeformation in142Eu

A rotational band with 15 transitions has been observed in¹⁴²Eu in an experiment with the GASP Ge detector array by the¹¹⁰Pd(³⁷Cl,5_n) reaction. The average energy spacing between the neighbouring transitions is 60 keV, which is similar to the energy spacings in the superdeformed bands in the mass 140 region. The band has a constant dynamic moment of inertia as suggested by Cranked Shell Model calculations.     

High-resolution infrared measurements on HSOH: Analysis of the OH fundamental vibrational mode

High-resolution infrared measurements of the OH-stretching mode of oxadisulfane, HSOH, at 3625 cm⁻¹ have been recorded using a Bruker IFS 120 HR Fourier transform spectrometer. More than 1300 lines have been assigned to the ν(OH) fundamental vibration mode, which is a hybrid band showing a c-type perpendicular band and an a-type parallel band spectrum of an asymmetric rotor molecule. The splitting due to the torsional-tunneling has not been observed in this band. The band center position at 3625.59260(20) cm⁻¹ as well as rotational and centrifugal distortion constants for the ν(OH) vibrational excited state have been obtained from a least-squares fit analysis of a semirigid rotor. In addition the α_OH experimental vibration-rotation correction terms of the OH-stretching mode have been derived and compared to values used in an earlier semi-empirical calculation of the HSOH structure. All data are in very good agreement with high level ab initio calculations and confirm the assignment of an earlier matrix isolation spectrum at 3608 cm⁻¹ to the ν(OH) fundamental mode.     

Stoichiometry dependence of the OH- absorption band in LiNbO3 crystals

Hydrogen in the form of OH^- ions can be incorporated into LiNbO₃ single crystals during the growth process. The infrared absorption band due to the OH^- defects has been measured at room temperature and a considerable change of the band shape has been observed depending on the crystal composition. The structure of the band found in nearly stoichiometric crystals indicates three slightly different proton sites which can be explained on the basis of the LiNbO₃ crystal structure.     

The ν9 fundamental of ethane: Integrated intensity and band absorption measurements with application to the atmospheres of the major planets

Measurements of the absolute intensity and integrated band absorption have been performed for the ν₉ fundamental band of ethane. The intensity is found to be 34 ± 1.6 cm^-2 atm^-1 at STP, and this is significantly higher than previous estimates. It is shown that a Gaussian profile provides an empirical representation of the apparent spectral absorption coefficient. Employing this empirical profile, a simple expression is derived for the integrated band absorption, which is in excellent agreement with experimental values. The band model is then employed to investigate the possible role of ethane as a source of thermal infrared opacity within the atmospheres of Jupiter and Saturn, and to interpret qualitatively observed brightness temperatures for Saturn.     

High-spin states in148Tb

High spin states of¹¹⁷Xe have been investigated by means of in-beam γ-ray spectroscopy using the reaction⁹²Mo(²⁸Si, 2pn) at beam energies of 100 to 120 MeV. The previously known νh_11/2 bands are confirmed and the νg_7/2 favored-signature band is extended up to 47/2⁺, in which two band crossings are observed at ?ω=0.33 and 0.44 MeV, respectively. Two new positive-parity bands have been established, one of which is most likely the νg_7/2 unfavored-signature band. A new transition cascade with irregular level spacings is also observed.     

Properties of vanadium in InP

Experiments are performed on InP/V single crystals extracted from a polycristalline ingot grown in a two zones gradient freeze furnace; in photoluminescence (PL) we observe a band with two zero phonon lines at 5692.5 cm^-1 and 5705.5 cm^-1. Photoluminescence excitation (P.L.E.) spectra have also been observed. This type of luminescence spectra has already been observed in V doped GaAs and GaP and attributed to an internal transition of V²⁺ (3 d³). D.L.T.S. and O.D.L.T.S. experiments do not reveal any deep level in the forbidden band gap. These two results seem to indicate a puzzling behaviour of V in InP as in GaAs which is discussed in the framework of a model proposed for GaAs/V : the V²⁺ ground state has a large relaxation energy and so, the excited states giving rise to the P.L. and P.L.E. spectra are not resonant with the conduction band.     

Band crossing in 162Dy: Characterisation of negative-parity yrast and yrare sequences

The crossing of an octupole band by a rotation-aligned two-quasiparticle band has been observed in detail in ¹⁶²Dy. Both the yrast and yrare states are identified from the band heads (I =2 and I = 5) to high spin (I ～ 14), with band crossing in both the even-spin and odd-spin sequences.     

Levels in doubly odd 138Pr

The band structures of the doubly odd ¹³⁸Pr nucleus have been investigated using the ¹²⁸Te(¹⁴N, 4n)¹³⁸Pr reaction at a beam energy of 55-65 MeV. Altogether six distinct structures have been established, of which the lower part of the yrast band and two side bands were known from earlier works. The observed level properties of the members of the yrast band have been compared with theoretical calculations performed within the Particle Rotor Model (PRM) with axially symmetric core. The experimental branching ratios and B(M1)/B(E2) values when compared with the theoretical results of the PRM, suggest an oblate core.     

The absorption and fluorescence spectra of matrix-isolated CF2

The CF₂ absorption spectrum between 2700 and 2250 Å and its fluorescence spectrum excited by radiation near 2500 Å have been observed in matrix isolation experiments. The positions of the absorption bands are somewhat dependent on the environment in which the CF₂ molecule is trapped. The absorption spectrum can be explained in terms of a progression in the upper-state bending fundamental, with a band spacing of 499 cm⁻¹, and the fluorescence spectrum involves a progression in the ground-state bending fundamental, with a band spacing of 657 cm⁻¹. A significant deviation between the calculated and observed separation of any given absorption and emission band can be explained by considering the effect of phonon interactions. Arguments are presented suggesting that the band origin lies near 36 900 cm⁻¹ for CF₂ produced by the photolysis of CF₂N₂ in an argon matrix.     

Evidence for band termination in118Xe

The yrast band of¹¹⁸Xe has been extended up to tentativelyI ^π = 34⁺ in a heavy-ion in-beam γ-spectroscopic study using the NORDBALL detector array. A band crossing is observed at the highest spins and interpreted within the Modified Oscillator Model as a transition to a terminating band.     

Observation of a superdeformed band in <Superscript>190</Superscript>Pb

A superdeformed band has been observed in the N = 108 isotope ¹⁹⁰Pb. This is the most neutron-deficient Pb isotope in which superdeformed states have been observed. Several theoretical approaches have predicted that N = 108 will mark the limit of observable superdeformation in the Pb isotopes. The band, which consists of five (possibly six) transitions, is observed to feed at least one isomeric level in its decay to the ground state. This decay pattern supports a spin assignment of 10 for the lowest observed level.     

Four quasi-particle band in the odd-odd158TM nucleus

The¹²⁵Te (³⁷CI,4n) reaction has been used to study the high spin states of¹⁵⁸Tm by means of in beam gamma ray spectroscopy using Compton suppressed germanium detectors of the “Château de Cristal” facility. Besides the Yrast band, the rotational character of which is clearly established up to the 23^? level only, a new rotational band developed up to spin 33⁺ is also observed. It is interpreted as a 4QP band.     

Line parameters for the 01111-00001 band of COO from SOIR measurements of the Venus atmosphere

CO₂ is the major constituent of the atmosphere of Venus. Absorption lines due to its ¹²C¹⁶O¹⁸O isotopologue have been observed for the first time in Venus spectra in the 2930-3015 cm⁻¹ spectral region, where the HITRAN database does not contain any line from this isotopologue. The measurements were performed by the SOIR instrument, which is part of the SPICAV/SOIR instrument on board the Venus Express mission of ESA. SOIR measured the atmospheric transmission of the upper atmosphere of Venus (z>70 km) by performing a solar occultation experiment using the atmosphere as a gigantic absorption cell. The identification of this newly observed band was first made recently from Mars atmosphere observations by US colleagues. We have made independent theoretical calculations of the positions of the lines of this new 01111-00001 absorption band, which coincide perfectly with the positions of the observed lines. Assuming an oxygen isotopic ratio similar to the one measured previously in the lower atmosphere of Venus, the line strengths of each observed line are deduced and listed.     

Lifetime measurement of the ((11/2)−) isomer in 125Cs

A new rotational band has been observed in ¹⁶⁷Lu by ¹⁵²Sm (¹⁹F,4n)reaction at the HI-13 tandem accelerator of CIAE in Beijing. The high spin transition energies of the new band are almost identical to the triaxial superdeformed bands recently discovered in ¹⁶³Lu and ¹⁶⁵Lu. This new band is predicted as a triaxial superdeformed band by total routhian surface calculations. Received: 6 October 1997     

Infrared spectra of the polar and nonpolar N2O dimers in the 1280 cm region of the ν3 fundamental

The high-resolution infrared spectrum of the polar N₂O dimer has been observed in the region of the N₂O ν₃ fundamental (∼1280 cm⁻¹) using a tunable diode laser to probe a pulsed supersonic slit jet. About 120 rotational transitions were assigned in terms of an a/b hybrid band of a planar asymmetric top molecule with a slipped parallel structure. The vibrational origin was determined to be 1290.21 cm⁻¹, showing a blue shift of 5.31 cm⁻¹ with respect to the monomer band origin. In addition, the spectrum of the nonpolar isomer at 1279.71 cm⁻¹ has been remeasured and analyzed in improved detail. Small but widespread perturbations are noted in this band, which appear somewhat similar to larger effects observed previously in the ν₁ + ν₃ region for nonpolar (N₂O)₂.