40 research outputs found
Evaluation of the radioactive contamination in fungi genus Boletus in the region of Europe and Yunnan Province in China
New volatile polyazolylborates of copper(I) for MOCVD
The volatility of new bis- and tetrakis-(pyrazo1yl)borates of copper(1) with monodentate tertiary phosphines recently prepared has been prepared by the reaction between CuCI, phosphine and KBH2pz2 or KBpz, in CH3CN (Hpz is a pyrazole-type ligand) has been studied. The IR data in gas in a vast temperature region confirm the stability of precursors in vapour, suggesting the molecular structure in vapour being similar to that determined previously by X-ray difiaction. The dependence of the volatility on the number of the pyrazolyl-moieties and nature of phosphine is discussed. Film growth rates obtained &om MOCVD experiments, as well as XRD and SEM data for copper films deposited by using [CU&B(~~)~(PM~P~~)~] as precursor are reported
Structure and volatility of copper complexes containing pyrazolyl-based ligands
Volatility studies, electrospray mass spectra and IR in vapour phase were carried out for a series of Cu(I) and Cu(II) complexes containing anionic pyrazole-based ligands such as 4-acyl-5-pyrazolonates and poly(pyrazolyl)borates. The volatility has been related to structural features and molecular parameters of the copper complexes. The crystal structures of [Cu(Q′)2(bipy)]·(acetone)1.5 (Q′=1-phenyl-3-methyl-4-benzoyl-pyrazolon-5-ato, bipy=2,2′-bipyridyl) and [Cu(QF)2(phen)]·EtOH (QF=1-phenyl-3-methyl-4-trifluoroacetyl-pyrazolon-5-ato, phen=1,10-phenanthroline), have been also determined. In these complexes the copper atom is in a tetragonally distorted octahedral arrangement of the four O-atoms of pyrazolones with N2-donor ligand in equatorial position. Two sets of CuO distances, the longer being in axial positions, have been found. XRD data of films obtained from metal organic chemical vapour deposition MOCVD experiments on [Cu(poly(pyrazolyl)borate)(PR3)] complexes have also been reported
Histomorphometric, ultrastructural and microhardness evaluation of the osseointegration of a nanostructured titanium oxide coating by metal-organic chemical vapour deposition: an in vivo study
Over the past decade the increase of elderly population has determined a rise in the incidence of bone fractures, and the
improvement of the implant\u2013bone interface remains an open problem. Metal-organic chemical vapour deposition (MOCVD) has
recently been proposed as a technique to coat orthopaedic and dental prostheses with metal nanostructured oxide \ufb01lms either
through the decomposition of oxygenated compounds (single-source precursors) or the reaction of oxygen-free metal compounds
with oxygenating agents. The present study was performed to assess the in vivo biocompatibility of commercially pure Ti (control
material: TI/MA) implants (+ 2 mm5 mm length) coated with nanostructured TiO2 \ufb01lms by MOCVD (Ti/MOCVD) and then
inserted into rabbit femoral cortical (middhiaphysis) and cancellous (distal epiphysis) bone. Histomorphometric, ultrastructural and
microhardness investigations were carried out. Four and 12 weeks after surgery, signi\ufb01cant (po0:0005) increases in AI of Ti/
MOCVD implants were observed as compared to Ti/MA implants (distal femoral epiphysis: 4 weeks=8.2%, ns; 12 weeks=52.3%,
po0:005; femoral diaphysis: 4 weeks=20.2%, po0:0005; 12 weeks=10.7%, po0:005). Bone microhardness results showed
signi\ufb01cant increases for the Ti/MOCVD versus Ti/MA implants at 200mm in the femoral diaphysis (4 weeks=14.2, po0:005) and
distal femoral epiphysis (12 weeks=14.5, po0:01) at 4 and 12 weeks, respectively. In conclusion, the current \ufb01ndings demonstrate
that the nanostructured TiO2 coatingpositively affects the osseointegration rate of commercially pure Ti implants and the bone
mineralization at the bone\u2013biomaterial interface in both cortical and cancellous bon
Estimating the biological half-life for radionuclides in homoeothermic vertebrates: a simplified allometric approach
The application of allometric, or mass-dependent,
relationships within radioecology has increased with the
evolution of models to predict the exposure of organisms
other than man. Allometry presents a method of addressing
the lack of empirical data on radionuclide transfer and
metabolism for the many radionuclide–species combinations
which may need to be considered. However, sufficient data
across a range of species with different masses are required to
establish allometric relationships and this is not always
available. Here, an alternative allometric approach to predict
the biological half-life of radionuclides in homoeothermic
vertebrates which does not require such data is derived.
Biological half-life values are predicted for four radionuclides
and compared to available data for a range of species.
All predictions were within a factor of five of the observed
values when the model was parameterised appropriate to the
feeding strategy of each species. This is an encouraging level
of agreement given that the allometric models are intended to
provide broad approximations rather than exact values.
However, reasons why some radionuclides deviate from what
would be anticipated from Kleiber’s law need to be determined
to allow a more complete exploitation of the potential
of allometric extrapolation within radioecological models