Biomedical subjects

A Ercan

Publications and source records attributed to A Ercan.

3 recordsLinked to original sources

PubMed2006

Analog pixel array detectors.

X-ray pixel array detectors (PADs) are generally thought of as either digital photon counters (DPADs) or X-ray analog-integrating pixel array detectors (APADs). Experiences with APADs, which are especially well suited for X-ray imaging experiments where transient or high instantaneous flux events must be recorded, are reported. The design, characterization and experimental applications of several APAD designs developed at Cornell University are discussed. The simplest design is a ;flash' architecture, wherein successive integrated X-ray images, as short as several hundred nanoseconds in duration, are stored in the detector chips for later off-chip digitization. Radiography experiments using a prototype flash APAD are summarized. Another design has been implemented that combines flash capability with the ability to continuously stream X-ray images at slower (e.g. milliseconds) rates. Progress is described towards radiation-hardened APADs that can be tiled to cover a large area. A mixed-mode PAD, design by combining many of the attractive features of both APADs and DPADs, is also described.

Equipment Design↗

PubMed2001

[Blunt injury of the aortic arch: report of two cases].

Blunt injury of the aortic arch and its great vessels is rare. Although most of the cases die at the event side, those who can reach the hospital present with a clinic of pseudoaneurysm or arterial occlusion. The mainstay of diagnosis is to have a high suspicion index. As the physical examination findings are subtle, radiodiagnostic tools are helpful. Aortography is the most important investigation technique in suitable cases in order to plan surgery. Extracorporeal circulation and deep hypothermia may successfully be used with known side effects. In this study, we report our recent experience with two cases of blunt injury of the arcus aorta.

Adolescent↗

PubMed1999

Simple, high-yield purification of xanthine oxidase from bovine milk.

Xanthine oxidase, a commercially important enzyme with a wide area of application, was extracted from fresh milk, without added preservatives, using toluene and heat. The short purification procedure, with high yield, consisted of extraction, ammonium sulfate fractionation, and DEAE-Sepharose (fast flow) column chromatography. Xanthine oxidase was eluted as a single activity peak from the column using a buffer gradient. The purification fold, specific activity and yield for the purified xanthine oxidase were 328, 10.161 U/mg and 69%, respectively. The enzyme was concentrated by ultrafiltration, although 31% of the activity was lost during concentration, no change in specific activity was observed. Activity and protein gave coincident staining bands on native polyacrylamide gels. The intensity and the number of bands were dependent on the oxidative state(s) of the enzyme; reduction by 2-mercaptoethanol decreased the intensity of the slow-moving bands and increased the intensity of the fastest-moving band. Following sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), two major bands (molecular masses of 152 and 131 kDa) were observed, accounting for > or = 95% of xanthine oxidase. Native- and SDS-PAGE showed that the purified xanthine oxidase becomes a heterodimer due to endogenous proteases.

Animals↗