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Biomedical subjects

A G Swanson

Publications and source records attributed to A G Swanson.

At least 19 recordsLinked to original sources
PubMed1999

Randomized acquisition for the suppression of systematic F1 artifacts in two-dimensional NMR spectroscopy.

2D spectra, particularly for homonuclear correlation, can show a variety of artifactual signals in the F1 domain. Common sources include carry-over of signal modulation from one transient to the next ("rapid pulsing artifacts") and systematic variations in room temperature ("parallel diagonals"). In both cases there is one very simple expedient which can greatly reduce the impact of these sources of error. Multidimensional data sets are almost invariably recorded by simply incrementing or decrementing evolution periods, largely for reasons of convenience and historical precedent. If instead the sampling of the evolution periods is carried out in random order, the perturbations responsible for the sharp F1 signals in the conventional experiment manifest themselves as t1 noise. Since the randomized acquisition redistributes coherent artifactual signals randomly in F1, the maximum artifactual signal is substantially reduced in the randomized experiment and no longer appears in the form of misleading distinct peaks.

Magnetic Resonance Spectroscopy↗
PubMed1997

High-performance liquid chromatography/NMR spectrometry/mass spectrometry: further advances in hyphenated technology.

The earlier use of combined liquid chromatography/NMR spectrometry/mass spectrometry (LC/NMR/MS) involved the use of a particle beam interface. This paper describes further developments of this hyphenated technology, in particular the incorporation of an electrospray interface into the LC/NMR/MS system. This improved LC/NMR/MS system was designed for the support of a combinatorial library program. The power of this technique is demonstrated in the successful structural elucidation of each compound in a mixture of commercially available peptides.

Chemical Phenomena↗
PubMed1997

On-line liquid chromatography coupled with high field NMR and mass spectrometry (LC-NMR-MS): a new technique for drug metabolite structure elucidation.

High performance liquid chromatography has been coupled simultaneously to high field NMR and MS detectors, giving UV, NMR and mass spectra for each component in a mixture, after on-line separation. This powerful new tool for the structure elucidation of components in mixtures without isolation has been successfully applied to the analysis of the metabolites of paracetamol in human urine.

Acetaminophen↗
PubMed1994

Identification of ethanolamine in rat and gerbil brain tissue extracts by NMR spectroscopy.

Some NMR resonances which have previously been observed but not identified in mammalian brain tissue extracts have been shown to arise from ethanolamine. This conclusion is drawn from a systematic study of the perchloric acid extracts of rodent brain tissue in which several NMR experiments were used to assign the peaks unambiguously. The extraction procedure used in this work gave samples with highly reproducible spectra, and ethanolamine was observed in all our extract samples. A localized increase in the concentration of ethanolamine was seen in the spectra of extracts produced from a cerebral infarct induced by occlusion of the middle cerebral artery in the rat.

Animals↗
PubMed1992

A national, interdisciplinary consortium of primary care organizations to promote the education of generalist physicians.

This essay begins with the history from 1989 through late 1991 of the Primary Care Organization's Consortium (PCOC), a group of representatives from nine major academic and professional organizations for primary care specialties. The PCOC was formed to discuss what might be done to reverse the alarming decrease in the number of medical students who choose primary care specialties. The article reviews some of the conditions that many believe have caused the continuing move away from primary care careers, and concludes with a description of the PCOC's program to encourage medical students to choose primary care careers, and the new opportunities for collaborative planning of such programs that are now available to medical schools. The PCOC's success in defining its program is due to a process of interdisciplinary planning and collaboration at the national level that hopefully will facilitate similar collaboration among medical school departments.

Career Choice↗
PubMed1989

Specialty choice.

Explore the source record for details and available documents.

Career Choice↗
PubMed1986

United States citizens studying medicine abroad. Their backgrounds and test performance.

To acquire information about the characteristics of U.S. citizens who had recently studied medicine abroad, the Educational Commission for Foreign Medical Graduates (ECFMG) and the Association of American Medical Colleges merged independently collected data on a study group of 10,460 U.S. citizens who attended 359 medical schools in 75 foreign countries and who took their first ECFMG examination between 1978 and 1982. The study group was markedly heterogeneous: 21 percent were not U.S. citizens at birth, 32 percent did not have English as a native language, and 12 percent had two or more years of undergraduate college education in Puerto Rico. Sixty-seven percent resided in New York, New Jersey, California, Florida, or Puerto Rico, and 74 percent studied medicine in Mexico or the Caribbean. Forty-six percent passed the ECFMG examination on their first attempt, and 22 percent passed a subsequent examination. Only 45 percent had applied to a U.S. medical school, and 65 percent had taken the Medical College Admission Test. The means of the college grade-point averages, known for 39 percent of the study group, and of the scores on the admission test, known for 65 percent, were lower than those of both accepted and unaccepted applicants to U.S. medical schools in the 1976 and 1978 entering classes. The finding that 55 percent of the study group did not apply to a U.S. medical school does not support the widely held belief that most, if not all, U.S. citizens who attend foreign medical schools do so only after several unsuccessful attempts to gain admission to a U.S. school.

Adult↗