82 research outputs found
Psychosocial and treatment correlates of opiate free success in a clinical review of a naltrexone implant program
Background: There is on-going controversy in relation to the efficacy of naltrexone used for the treatment of heroin addiction, and the important covariates of that success. We were also interested to review our experience with two depot forms of implantable naltrexone. Methods: A retrospective review of patients' charts was undertaken, patients were recalled by telephone and by letter, and urine drug screen samples were collected. Opiate free success (OFS) was the parameter of interest. Three groups were defined. The first two were treated in the previous 12 months and comprised "implant" and "tablet" patients. A third group was "historical" comprising those treated orally in the preceding 12 months. Results: There were 102, 113 and 161 patients in each group respectively. Groups were matched for age, sex, and dose of heroin used, but not financial status or social support. The overall follow-up rate was 82%. The Kaplan Meier 12 month OFS were 82%, 58% and 52% respectively. 12 post-treatment variables were independently associated with treatment retention. In a Cox proportional hazard multivariate model social support, the number of detoxification episodes, post-treatment employment, the use of multiple implant episodes and spiritual belief were significantly related to OFS. Conclusion: Consistent with the voluminous international literature clinically useful retention rates can be achieved with naltrexone, which may be improved by implants and particularly serial implants, repeat detoxification, meticulous clinical follow-up, and social support. As depot formulations of naltrexone become increasingly available such results can guide their clinical deployment, improve treatment outcomes, and enlarge the policy options for an exciting non-addictive pharmacotherapy for opiate addiction
EMSL and Institute for Integrated Catalysis (IIC) Catalysis Workshop
Within the context of significantly accelerating scientific progress in research areas that address important societal problems, a workshop was held in November 2010 at EMSL to identify specific and topically important areas of research and capability needs in catalysis-related science
Attitudes toward Substance Abuse Clients: An Empirical Study of Clinical Psychology Trainees
Chemical Trends in Solid Alkali Pertechnetates
Insight into the solid-state chemistry of pure technetium-99 (99Tc) oxides is required in the development of a robust immobilization and disposal system for nuclear waste stemming from the radiopharmaceutical industry, from the production of nuclear weapons, and from spent nuclear fuel. However, because of its radiotoxicity and the subsequent requirement of special facilities and handling procedures for research, only a few studies have been completed, many of which are over 20 years old. In this study, we report the synthesis of pure alkali pertechnetates (sodium, potassium, rubidium, and cesium) and analysis of these compounds by Raman spectroscopy, X-ray absorption spectroscopy (XANES and EXAFS), solid-state nuclear magnetic resonance (static and magic angle spinning), and neutron diffraction. The structures and spectral signatures of these compounds will aid in refining the understanding of 99Tc incorporation into and release from nuclear waste glasses. NaTcO4 shows aspects of the relatively higher electronegativity of the Na atom, resulting in large distortions of the pertechnetate tetrahedron and deshielding of the 99Tc nucleus relative to the aqueous TcO4 –. At the other extreme, the large Cs and Rb atoms interact only weakly with the pertechnetate, have closer to perfect tetrahedral symmetry at the Tc atom, and have very similar vibrational spectra, even though the crystal structure of CsTcO4 is orthorhombic while that of RbTcO4 is tetragonal. Further trends are observed in the cell volume and quadrupolar coupling constant
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Chemical Trends in Solid Alkali Pertechnetates.
Insight into the solid-state chemistry of pure technetium-99 (99Tc) oxides is required in the development of a robust immobilization and disposal system for nuclear waste stemming from the radiopharmaceutical industry, from the production of nuclear weapons, and from spent nuclear fuel. However, because of its radiotoxicity and the subsequent requirement of special facilities and handling procedures for research, only a few studies have been completed, many of which are over 20 years old. In this study, we report the synthesis of pure alkali pertechnetates (sodium, potassium, rubidium, and cesium) and analysis of these compounds by Raman spectroscopy, X-ray absorption spectroscopy (XANES and EXAFS), solid-state nuclear magnetic resonance (static and magic angle spinning), and neutron diffraction. The structures and spectral signatures of these compounds will aid in refining the understanding of 99Tc incorporation into and release from nuclear waste glasses. NaTcO4 shows aspects of the relatively higher electronegativity of the Na atom, resulting in large distortions of the pertechnetate tetrahedron and deshielding of the 99Tc nucleus relative to the aqueous TcO4-. At the other extreme, the large Cs and Rb atoms interact only weakly with the pertechnetate, have closer to perfect tetrahedral symmetry at the Tc atom, and have very similar vibrational spectra, even though the crystal structure of CsTcO4 is orthorhombic while that of RbTcO4 is tetragonal. Further trends are observed in the cell volume and quadrupolar coupling constant
Surface Interactions and Confinement of Methane: A High Pressure Magic Angle Spinning NMR and Computational Chemistry Study
Characterization
and modeling of the molecular-level behavior of
simple hydrocarbon gases, such as methane, in the presence of both
nonporous and nanoporous mineral matrices allows for predictive understanding
of important processes in engineered and natural systems. In this
study, changes in local electromagnetic environments of the carbon
atoms in methane under conditions of high pressure (up to 130 bar)
and moderate temperature (up to 346 K) were observed with <sup>13</sup>C magic-angle spinning (MAS) NMR spectroscopy while the methane gas
was mixed with two model solid substrates: a fumed nonporous, 12 nm
particle size silica and a mesoporous silica with 200 nm particle
size and 4 nm average pore diameter. Examination of the interactions
between methane and the silica systems over temperatures and pressures
that include the supercritical regime was allowed by a novel high
pressure MAS sample containment system, which provided high resolution
spectra collected under in situ conditions. For pure methane, no significant
thermal effects were found for the observed <sup>13</sup>C chemical
shifts at all pressures studied here (28.2, 32.6, 56.4, 65.1, 112.7,
and 130.3 bar). However, the <sup>13</sup>C chemical shifts of resonances
arising from confined methane changed slightly with changes in temperature
in mixtures with mesoporous silica. The chemical shift values of <sup>13</sup>C nuclides in methane change measurably as a function of
pressure both in the pure state and in mixtures with both silica matrices,
with a more pronounced shift when meso-porous silica is present. Molecular-level
simulations utilizing GCMC, MD, and DFT confirm qualitatively that
the experimentally measured changes are attributed to interactions
of methane with the hydroxylated silica surfaces as well as densification
of methane within nanopores and on pore surfaces
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