Biomedical subjects

T Weitkamp

Publications and source records attributed to T Weitkamp.

5 recordsLinked to original sources

PubMed2005

Shearing interferometer for quantifying the coherence of hard x-ray beams.

We report a quantitative measurement of the full transverse coherence function of the 14.4 keV x-ray radiation produced by an undulator at the Swiss Light Source. An x-ray grating interferometer consisting of a beam splitter phase grating and an analyzer amplitude grating has been used to measure the degree of coherence as a function of the beam separation out to 30 microm. Importantly, the technique provides a model-free and spatially resolved measurement of the complex coherence function and is not restricted to high resolution detectors and small fields of view. The spatial characterization of the wave front has important applications in discovering localized defects in beam line optics.

Journal Article↗

PubMed2003

Synchrotron X-ray microtomography (on a micron scale) provides three-dimensional imaging representation of bone ingrowth in calcium phosphate biomaterials.

This study used synchrotron X-ray microtomography on a micron scale to compare three-dimensional (3D) bone ingrowth after implantation of various calcium phosphate bone substitutes in a rabbit model. The advantage of using this new method for the study of biomaterials was then compared with histomorphometry for analysis of interconnection and bone ingrowth. The study focused on the newly formed bone-biomaterial interface. Macroporous Biphasic Calcium Phosphate (MBCP) ceramic blocks and two different injectable calcium phosphate biomaterials [an injectable bone substitute (IBS) consisting of a biphasic calcium phosphate granule suspension in hydrosoluble polymer and a calcium phosphate cement material (CPC)] were studied after in vivo implantation. Absorption or phase-contrast microtomography was performed with the dedicated set-up at beamline ID22. Experimental spatial resolution was between 1 and 1.4 microm, depending on experimental radiation. All calcium phosphates tested showed osteoconduction. IBS observations after 3D reconstruction showed interconnected bioactive biomaterial with total open macroporosity and complete bone ingrowth as early as 3 weeks after implantation. This experimentation was consistent with two-dimensional histomorphometric analysis, which confirmed its suitability for biomaterials. This 3D study relates the different types of bone substitution to biomaterial architecture. As porosity and interconnection increase, bone ingrowth becomes greater at the expense of the bone substitute: IBS>MBCP>CPC.

Animals↗

PubMed2002

Quantitative analysis of two-component samples using in-line hard X-ray images.

Methods for rapid quantitative phase-sensitive X-ray imaging of non-crystalline samples consisting of two distinct components are investigated. The transverse spatial distribution of the projected thickness of each component is reconstructed by computer processing of in-line images collected using synchrotron-generated hard X-rays and a position-sensitive detector with submicrometre spatial resolution. Different imaging techniques and associated image-processing algorithms are considered, with relative advantages and difficulties of each approach compared. A possible generalization of the method for the case of n-component samples is briefly discussed.

Journal Article↗

PubMedDate not supplied

Nursing the community in cyberspace.

As nursing expands more into the community, the role of health promotion is finding its way on the information superhighway. Through NetWellness, nursing faculty experts at the University of Cincinnati College of Nursing and Health are providing health care information via the internet. Not only is the world wide web a site of their nursing practice, but also faculty are identifying new linkages to add to the College's curriculum.

Computer Communication Networks↗

PubMedDate not supplied

Promoting women's health via the World Wide Web.

Women, as a segment of society at risk for chronic illnesses and complications from normal life events, such as pregnancy and menopause, are seeking information to improve their health status. One tool on the World Wide Web provided by a team of Ohio health care providers, including nurses, physicians, pharmacists, and dietitians, is the Ask an Expert feature of NetWellness. Designed as a consumer health information resource, NetWellness (www.netwellness.org) also is a valuable tool to health care professionals.

Female↗