Reconstruction of the polar interface between hexagonal LuFeO3 and intergrown Fe3O4 nanolayers.

We report the observation of an unusual phase assembly behavior during the growth of hexagonal LuFeO(3) thin films which resulted in the formation of epitaxial Fe(3)O(4) nanolayers. The magnetite layers were up to 5 nm thick and grew under the conditions at which Fe(2)O(3) is thermodynamically stable. These Fe(3)O(4) nanolayers act as buffer layers promoting a highly epitaxial growth of the hexagonal LuFeO(3) thin film up to 150 nm thick. Using scanning transmission electron microscopy, we show that the interface between (001) LuFeO(3) and (111) Fe(3)O(4) can be reconstructed in two ways depending on the sequence in which these compounds grow on each other. We suggest the polarity of the interface is the reason behind the observed interface reconstruction and epitaxial stabilization of magnetite.

Solution to the bioheat equation for hyperthermia with La(1-x)Ag(y)MnO(3-delta) nanoparticles: the effect of temperature autostabilization.

This work aimed to analyze the possibility and performance of the temperature controlled hyperthermia based on AC heating of magnetic nanoparticles with low Curie temperature. Temperature dependence of dynamic magnetic susceptibility has been studied experimentally on fine powders of La(0.8)Ag(0.15)MnO(2.95) in the frequency range of 0.5-2.0 MHz. Critical drop of the AC magnetic losses was found in the vicinity of the Curie point, T(C) = 42 degrees C. The obtained data was used in the numerical analysis of the bioheat equations under typical conditions of the hyperthermia treatment. The mathematical model includes a spherical tumor containing magnetic particles and surrounded by concentric healthy tissue, with account made for the blood perfusion. The calculations performed for various AC power, tumor sizes and doping geometries predict effective autostabilization of the temperature at T congruent with T(C) inside the tumor and steep temperature profile at the interface with the healthy tissue.

Ag-doped manganite nanoparticles: new materials for temperature-controlled medical hyperthermia.

The purpose of this study was to introduce newly synthesized nanomaterials as an alternative to superparamagnetic ironoxide based particles (SPIO) and thus to launch a new platform for highly controllable hyperthermia cancer therapy and imaging. The new material that forms the basis for this article is lanthanum manganite particles with silver ions inserted into the perovskite lattice: La(1-x)Ag(x)MnO(3+delta). Adjusting the silver doping level, it is possible to control the Curie temperature (T(c)) in the hyperthermia range of interest (41-44 degrees C). A new class of nanoparticles based on silver-doped manganites La(1-x)Ag(x)MnO(3+delta) is suggested. New nanoparticles are stable, and their properties were not affected by the typical ambient conditions in the living tissue. It is possible to monitor the particle uptake and retention by MRI. When these particles are placed into an alternating magnetic field, their temperature increases to the definite value near T(c) and then remains constant if the magnetic field is maintained. During the hyperthermia procedure, the temperature can be restricted, thereby preventing the necrosis of normal tissue. A new class of nanoparticles based on silver-doped manganites La(1-x)Ag(x)MnO(3+delta) was suggested. Ag-doped perovskite manganites particles clearly demonstrated the effect of adjustable Curie temperature necessary for highly controllable cellular hyperthermia. The magnetic relaxation properties of the particles are comparable with that of SPIO, and so we were able to monitor the particle movement and retention by MRI. Thus, the new material combines the MRI contrast enhancement capability with targeted hyperthermia treatment.

Quantitative analysis of thin films of RBa(2)Cu(3)O(7-x) (R-rare earth elements) and ZrO(2) (Y(2)O(3)) buffer layers by SNMS.

It is shown that RBa(2)Cu(3)O(7-X) single crystals may be used as reference samples for the quantitative analysis of RBa(2)Cu(3)O(7-X) thin films by SNMS. RSF-values for Y and Cu (relative to Ba) determined for ceramic RBa(2)Cu(3)O(7-X) samples are higher than those for single crystals. This difference may be caused by Ba segregation on grain boundaries. The depth profile analysis of YSZ/Al(2)O(3) samples was performed by DBM using a Ni grid to prevent sample charging. The reproducibility of analysis was better than 10%.

A comparison of the practices used for distribution of controlled substances in Massachusetts hospitals with those reported nationally.

A survey questionnaire concerning the procedures used to distribute controlled substances was mailed to 100 randomly selected Massachusetts hospital pharmacies. The tabulated results were compared to a similar study surveying 285 short-term medical and surgical hospitals nationwide. Of the 58 responding hospitals, 47 (81%) reported controlling either all or some Schedule III Controlled Substances in a manner similar to that used for the distribution and accountability of Schedule II drugs. A total of 42 (72%) reported maintaining the same systems for Schedule IV agents. In contrast, only 24 (42%) of those respondents reported controlling Schedule V drugs in a manner similar to Schedule II Controlled Substances. Similar to the findings of a nationwide study, many of the responding Massachusetts hospitals reported selective inclusion of those Schedule III, IV, and V drugs possessing an increased risk of illicit diversion into a more controlled distribution system. In conclusion, many Massachusetts hospitals distribute and account for controlled substances in a manner similar to that used nationwide.