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At least 433 records · Page 24Linked to original sources
PubMed1997

Measurements of oxygen tension in the rat kidney after contrast media using an oxygen microelectrode with a guard cathode.

The oxygen tension (PO2) in the rat kidney was studied by modified Clark microelectrodes. Changes in PO2 were measured in the renal cortex and outer medulla after intravenous injections of the X-ray contrast medium (CM) diatrizoate, 370 mg iodine/mg body weight. Injection of diatrizoate caused a slight fall in PO2 in the renal cortex (from 42 +/- 4 to 38 +/- 4 mm Hg). In the medulla PO2 decreased significantly (from 34 +/- 6 to 20 +/- 4 mm Hg). Ringer's solution did not induce any changes.

Animals↗
PubMed1992

Practices and attitudes about cathode-ray tube-based and film-based image interpretation.

A questionnaire was mailed to 708 practicing radiologists and 348 members of the Society for Computer applications in Radiology (SCAR) in order to evaluate current practices and attitudes regarding the perceived advantages or disadvantages of film- and CRT-based image interpretation. A total of 27% of the 1,056 questionnaires (137 practicing radiologists; 145 SCAR members were returned. Ninety percent of practicing radiologists used film at least 75% of the time. Advantages of film-based reading listed by more than 75% of the respondents included: film reading is faster, and facilitates viewing multiple images. Advantages of CRT-based reading included: access to the entire dynamic range and potential imaging processing. Desirable attributes of existing displays included: adjustable grey scale, magnification, ability to view multiple images, allow quick review, and viewing by several individuals. Valued potential advances included: multiple higher resolution monitors, image processing and multimodality display. Practicing radiologists and computer applications society members had similar attitudes. Film-based reading is still nearly universal, but radiologists are interested in CRT-based reading if such devices have the proper features and become more available.

Attitude of Health Personnel↗
PubMed1995

Quality control of cathode-ray tube monitors for medical imaging using a simple photometer.

As computer monitors are used more in medical imaging and the use of picture archiving and communication system workstations with multiple monitors is increasing, quality control protocols become necessary to track subtle variations in performance characteristics. Several tests based on previously published work were applied to 10 monitors of three different types over a period of 5 months. Each test is explained, and the results are shown. For example, without corrective adjustments, 2 monitors from the same workstation showed a small but steady decline in maximum luminance of 8.1% and 7.6% over the course of 11 weeks that was not perceptible. From this experience, we took the first step toward developing a practical and useful quality control protocol. The proposed protocol requires only a photometer and the ability to generate the Society of Motion Picture and Television Engineers (SMPTE) test pattern, and takes approximately 5 minutes per monitor per week to gather data.

Data Display↗
PubMed2002

Assay of dipyridamole in human serum using cathodic adsorptive square-wave stripping voltammetry.

A rapid and sensitive square-wave voltammetric procedure was optimized for the determination of dipyridamole after its adsorption preconcentration onto a hanging mercury drop electrode. The peak current of the first of the two peaks developed for this drug in Britton-Robinson buffer at pH 8.0 has been considered for the present analytical study. An accumulation potential of -1.0 V versus Ag/AgCl/KCl(s), pulse amplitude a =100 mV, scan increment Delta E =10 mV, and frequency f =120 Hz were the optimal experimental parameters. Dipyridamole can be determined in the concentration range of 9.0 x 10(-9) to 5.0 x 10(-6) M using accumulation times of 30-300 s. A detection limit of 4.0 x 10(-11) M was achieved after a 300 s accumulation time. Applicability to serum samples was illustrated. The average recoveries for dipyridamole spiked to serum at 0.25-4.50 micro g ml(-1) were 96.0-102.0%, and the higher standard deviation was 2.9%. A detection limit of 0.06 micro g mL(-1) of serum was obtained.

Dipyridamole↗
PubMed2000

How faster and cheaper to determine chromium by adsorptive cathodic stripping voltammetry in the presence of DTPA and nitrate.

A modification of the voltammetric procedure for the determination of chromium in the presence of DTPA and nitrates was proposed. Morpholinoethanesulfonic (MES) acid and its sodium salt were used for stabilisation of pH instead of acetate buffer. In the presence of MES the determination of chromium can be carried out in the presence of dissolved oxygen without decrease of sensitivity of the measurements. Elimination of the purge step decreases total analysis time and saves gas.

Journal Article↗
PubMed1996

A new combined electrothermal-hollow cathode atom and emission sourceInstrumentation and preliminary investigation.

A new radiation source based on the FANES-method has been developed in order to achieve an intensity enhancement of the radiation produced. Investigations carried out with this new source are controlled by a computer system connected with a multichannel spectrometer having a wavelength modulated background corrector. First results show that the combination of the two sources increases the emission intensity of spectral lines.

Journal Article↗
PubMed2001

Factors affecting cathode ray tube display performance.

Monitors are a complex combination of analog circuits that perform absolutely amazing feats of current and voltage control at both low and high frequency. Digital circuits can reduce the complexity of interfacing with the adjustments and even be used to build complex waveforms, but they cannot replace the point at which pure power is required. Five main topic areas are covered, each building on the other in how they relate to display performance. They are glass composition, resolution and addressability, phosphor selection and aging characteristics, light output and uniformity, and the tools available to assess display performance.

Data Display↗