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Biomedical subjects

P J Schilling

Publications and source records attributed to P J Schilling.

13 recordsLinked to original sources
PubMed2002

Homogeneity of a supersaturated solid solution.

Extended x-ray absorption fine structures, small-angle x-ray scattering, and atomistic model calculations have been employed to probe the homogeneity of the fcc solution created in Ag-Cu, a classical system demonstrating the extension of solubility across the entire miscibility gap through rapid quenching. Our results reveal that in many cases the supersaturated solutions formed have decomposition features on the scale of 1 nm. Conventional diffraction methods are inadequate in determining the level of supersaturation or the uniformity of such solid solution alloys.

Journal Article↗
PubMed2001

X-ray fluorescence mapping and micro-XANES spectroscopic characterization of exhaust particulates emitted from auto engines burning MMT-added gasoline.

The elemental distribution and compositional homogeneity in auto exhaust particulates emitted from methylcyclopentadienyl manganese tricarbonyl-(MMT-)added gasoline engines have been investigated using a newly installed synchrotron X-ray microprobe. Two representative groups of exhaust particulate matter, as defined in a recent bulk X-ray absorption fine structure (XAFS) spectroscopic study at the Mn K-edge, were studied. The micro-X-ray absorption near-edge structure (XANES) spectra indicate a relatively homogeneous distribution of phases within a given particulate sample, down to a spatial extent of 40 microm (the resolution of microprobe). The micro-XANES also enabled analysis of several areas which displayed compositions different from the bulk sample, supporting the general theory describing manganese species formation in the exhaust. The ability to evaluate small regions also enabled direct verification of manganese sulfate from the S XANES despite the vast excess of sulfur present in other forms. The presence of a chloride compound, introduced through the sample dilution air and engine intake air, was also revealed. The study demonstrates the value of the combined X-ray microfluorescence with excitation by polychromatic radiation for elemental mapping and micro-XANES spectroscopy for chemical speciation in the study of dilute environmental materials containing low-Z constituents such as Cl, S, and P.

Air Pollutants↗
PubMed2001

Amorphous structures in the immiscible Ag-Ni system.

Vapor quenching in the phase-separating Ag-Ni system creates alloys that appear homogeneously amorphous under conventional probes. However, an atomic-level structural analysis based on extended x-ray absorption fine structures in combination with reverse Monte Carlo and molecular dynamics simulations demonstrates that these new phases are characterized by nonuniform, spinodal-like structures on an extremely fine scale. This heterogeneous nature of the structure is directly responsible for the unexpectedly low heat (and temperature) of crystallization observed in calorimetric measurements.

Journal Article↗
PubMed1994

Results of the 1992 association of residents in radiation oncology (ARRO) survey.

In 1992 the Association of Residents in Radiation Oncology (ARRO) conducted its ninth annual survey of all residents in training. The survey identified perceived strengths and shortcomings of training. Factors influencing the choice of Radiation Oncology as a medical specialty were identified. Residents raised concerns over the adequacy and preparation of training. Factors influencing the decision to enter private practice or academic medicine were also identified. Future surveys are planned to expand this important database.

Adult↗
PubMed1992

Novel tumor necrosis factor toxic effects. Pulmonary hemorrhage and severe hepatic dysfunction.

Recombinant human tumor necrosis factor is an investigational antitumor agent currently undergoing clinical trials. Previous reports of pulmonary and hepatic toxicities include mild reversible decline in pulmonary diffusing capacity and mild elevation of bilirubin and transaminases. This report describes two novel toxicities in patients receiving their first intravenous dose of tumor necrosis factor: pulmonary hemorrhage and severe hepatic dysfunction. These patients received no other antitumor therapy for at least 4 weeks before tumor necrosis factor treatment and no additional antitumor therapy concomitant with tumor necrosis factor. An analysis of the possible pathogenesis is presented.

Adult↗
PubMed1991

Development of systemic lupus erythematosus after interferon therapy for chronic myelogenous leukemia.

A 19-year-old man with Philadelphia-positive chronic myelogenous leukemia treated with interferon-alpha (IFN-alpha) therapy for 45 months had systemic lupus erythematosus disease features: malar rash, migratory arthralgias, elevated antinuclear antibodies, elevated antinative DNA, hypocomplementemia, lymphopenia, and proteinuria. After discontinuation of the IFN and initiation of corticosteroids, there was gradual recovery of symptoms, a decline in antinative DNA and antinuclear antibodies to normal levels, and a decrease in proteinuria. The potential association between IFN therapy and the development of systemic lupus erythematosus, and the role of IFN in other autoimmune diseases, is discussed.

Adult↗
PubMed1975

Pseudo-retroperitoneal gas in rupture of aneurysm of abdominal aorta.

Four cases of ruptured abdominal aortic aneurysm producing retroperitoneal radiolucent shadows are presented. Gross and microscopic examination showed this to be due to dissection of blood through the retroperitoneal fat. This finding has been helpful in confirming the presence of retroperitoneal hemorrhage.

Aged↗
PubMedDate not supplied

Radiation oncology practice accreditation.

The practice accreditation program of The American College of Radiology is described. Practice accreditation constitutes a facile mechanism to accomplish external quality assurance and to assess compliance with recognized standards. The process of accreditation includes critical review of each radiation therapy facility, the technical staff, all quality assurance procedures, medical physics staff, nursing and physician personnel as well as a whole host of other items, the most important of which is meticulous examination of selected patient charts. In the appendix, standards developed by the American College of Radiation Oncology, are reported.

Accreditation↗