The polarized Raman spectra of Ca2Cu03, C a l . s S r ~. ~C u O ~ and Ca1.6Sro.rCuO3 single oystals and the IR transmission spenra of Ca~Cu03 and Cal.aSro.rOuO~ have been measured. The frequencies of all I'point phonons of Ca2Cuo3 have been dclermined on the basis of assignment of the one-phonon Raman (4) and IR lines 10 definite normal modes and alculalions of the lattice dynamics. The line assignment is wnsislenl wilh earlier mults for Cal.gSr0.2ChO3 as well BS with the line shifts upon substitution of Sr for Ca. I h e inlensive bmad lines in the (bb)polarized Raman speclra of both Sr-free and Sr-subtiluted ?ample (in addition l o the two As Lines already assigned) have been attributed to resonanlly enhanced two-phonon scattering involving modes related 10 motions of Cu andlor O(2) atoms. A coincidence has k e n found between most of the line frequencies and half-widlhs in the (bb)polarized Raman spectra and some of the maxima in the two-phonon density of stales as oblained fmm lattice dynamirs calculations.

The present study describes a simultaneous and highly reproducible large-scale synthesis of six (and more) colors of size-homogeneous and highly luminescent CdSe quantum dots in a single reaction, controlled by a slow-increasing temperature gradient. The described protocol allows a precise control and a synchronized isolation of aliquots of CdSe nanocrystals with defined sizes, avoiding disturbance of the growth of nanocrystals (existing in the reaction mixture) to the isolation of the next aliquot. The obtained quantum dot fractions are of high quality (in 95% size-homogeneous) and have sharp photoluminescence spectra (fwhm approximately 30 nm), quantum yields of 45-70% (in organic solvent), and a lack of aggregation in organic solvents. The method is environmentally friendly as it ensures almost complete utilization of the precursors and productive yield approximately 95%.

Resonant Raman scattering by ion beam synthesized in silicon matrix Mg 2 Si phase is studied. The samples are prepared with the implantation of 24 Mg + ions with dose 4 ϫ 10 17 cm −2 and with two different energies 40 and 60 keV into ͑100͒Si substrates. The far infrared spectra are used as criteria for the formation of the Mg 2 Si phase. The Raman spectra are excited with different lines of Ar + laser, with energies of the lines lying in the interval from 2.40 to 2.75 eV. The resonant scattering can be investigated using these laser lines, as far as according to the Mg 2 Si band structure, there are direct gaps with energies in the same region. The energy dependences of the scattered intensities in the case of the scattering by the allowed F 2g and the forbidden LO-type modes are experimentally obtained and theoretically interpreted. On the base of the investigation energies of the interband transitions in the Mg 2 Si are determined. It is found also that the resonant Raman scattering appears to be a powerful tool for characterization of a material with inclusions in it. In the particular case it is concluded that the Mg 2 Si phase is present in the form of a surface layer in the sample, prepared with implantation energy 40 keV and as low-dimensional precipitates, embedded in the silicon matrix, in the sample, prepared with the higher implantation energy.

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The present study was designed to investigate whether poly-ion complex hollow vesicles (polymersomes), based on chemically modified chitosan, are appropriate for passive tumour targeting in the context of their application as drug carriers. The experiments were performed on colon cancer-grafted mice. The mice were subjected to anaesthesia and injected intravenously with water-soluble nanoparticles: (1) QD705-labelled polymersomes (average size ∼120 nm; size distribution ∼10%) or (2) native QD705. The optical imaging was carried out on Maestro EX 2.10 In Vivo Imaging System (excitation filter 435–480 nm; emission filter 700 nm, longpass). In the case of QD705, the fluorescence appeared in the tumour area within 1 min after injection and disappeared completely within 60 min. A strong fluorescent signal was detected in the liver on the 30th minute. The visualization of tumour using QD705 was based only on angiogenesis. In the case of QD705-labelled polymersomes, the fluorescence appeared in the tumour area immediately after injection with excellent visualization of blood vessels in the whole body. A strong fluorescent signal was detected in the tumour area within 16 hours. This indicated that QD705-labelled polymersomes were delivered predominantly into the tumour due to their long circulation in the bloodstream and enhanced permeability and retention effect. A very weak fluorescent signal was found in the liver area. The data suggest that size-controlled long-circulating polymersomes are very promising carriers for drug delivery in solid tumours, including delivery of small nanoparticles and contrast substances.