Long-term stability of hydroxyapatite bone phantoms for the calibration ofin vivox-ray fluorescence spectrometry-based systems of bone lead and strontium quantification.

Hydroxyapatite (HAp) phantoms have been proposed as an alternative to plaster of Paris (poP) phantoms for the calibration of x-ray fluorescence-based systems for thein vivoquantification of bone lead and strontium which employ a coherent normalization procedure. The chemical composition of the material becomes critical in the calculation, or omission, of the coherent correction factor (CCF) required in this normalization procedure. This study evaluated the long-term chemical stability of HAp phantoms. Phantoms were prepared and allowed to age for a two week period and over a seven year period in ambient conditions. The chemical composition of the phantoms was then assessed by powder x-ray diffraction. Two week old phantoms were found to be composed of HAp with only a small amount of contamination from CaHPO4·2H2O. Seven year old phantoms were found to have converted nearly completely to a carbonate-bearing apatite in the form of Ca10(PO4)6(CO3)0.75(OH)0.5indicating that the HAp phantom material likely reacts with carbon dioxide in air over time forming a carbonate-bearing apatite. The influence of this chemical conversion was assessed at the level of relevant cross-sections. Calibration under the assumption that the material is HAp when in fact it is a carbonate-bearing apatite would result in not more than a 0.2%-2% bias in the total mass attenuation coefficient within the photon energy range of 0-100 keV. Differential scattering cross-section for coherent scattering was found to differ between HAp and carbonate-bearing apatite by 0.9%-2% for both a 35.5 keV and 88.0 keVγ-ray. This variation in the differential scattering cross-section for coherent scattering may introduce a ca. 2% bias in the CCF used within the coherent normalization-based calibration procedure. Using HAp phantoms as calibrators thus requires acknowledgement of this conversion in chemical form and possible introduction of uncertainty into the calibration procedure.

The Culture and Justice Quorum at University of California, San Diego: A Departmental Approach to Dismantling Structural Racism.

PROBLEM: Structural racism is embedded within the structure and function of academic medical institutions. Although many institutions have begun to incorporate racial justice within academic medicine, it needs to be integral to every discipline and all aspects of medical education, research, and health system practice. Guidance is lacking, however, on how to create and sustain department-level action to shift culture and encourage antiracist work. APPROACH: To address the culture, uphold racial justice, and address the challenges of racism in medicine with dynamic and innovative solutions, the Department of Obstetrics, Gynecology and Reproductive Sciences at University of California, San Diego, formed a Culture and Justice Quorum (the Quorum) in September 2020. All department faculty, residents, fellows, and staff were invited to participate in the Quorum as ambassadors who commit to meet and facilitate Quorum work or as supporters who pledge Quorum support without regular meeting participation. OUTCOMES: In all, 153 of 155 invited individuals (98.7%) responded, with 36 (23.2%) requesting to participate as ambassadors and 117 (75.5%) as supporters. Quorum ambassadors have worked together to assess the climate of the department, university, and health system, including incorporating input and amplifying efforts of the department's resident leadership council. The Quorum has implemented initiatives to promote health equity and developed a report card to demonstrate activities, monitor progress, and ensure accountability. NEXT STEPS: Through the innovative Culture and Justice Quorum, the department aims to address structural racism, foster justice, and dismantle the foundational injustices embedded within departmental clinical, educational, and research work and within the wider culture. The Quorum offers a model for creating and sustaining department-level action to shift culture and encourage antiracist work. Since established, it has received institutional recognition, including receiving the 2022 Inclusive Excellent Award for Department-Organizational Unit, which recognizes outstanding institutional contributions for inclusion and diversity efforts.

Impact of a student-led community education program to promote Pap test screening among Asian-American women.

INTRODUCTION: Among ethnic groups, Asian-American women have the highest incidence of cervical cancer, low cervical cancer screening rates, and are more likely to state they have "never thought about" and/or "do not need" Pap testing. Through a Patient Advocacy grant awarded by the American Society of Cytopathology Foundation, we developed a culturally sensitive educational outreach program to encourage Pap screening among Asian-Americans in our community. MATERIALS AND METHODS: Educational materials, translated into three languages, were shared at nine community events by undergraduate and medical student volunteers. Pre- and post-education surveys on awareness, knowledge, and attitudes towards screening were administered. Results were tallied and reported as raw percentages. RESULTS: A total of 328 surveys were completed; 80% were Asian respondents. Twenty percent of respondents were not up to date (NUTD) with Pap screening. Knowledge of Pap tests reported as "excellent"/"good" rose from 46% before to 85% after education. Those reporting "very likely"/"likely" to schedule a Pap test increased from 72% to 92% in the NUTD group and from 84% to 97% in the 21-29 age group. Those reporting "very likely"/"likely" to recommend a Pap test to others increased from 68% to 98% in the NUTD group and 77% to 97% in those aged 21-29. CONCLUSIONS: A student-led community-based culturally sensitive outreach approach improved Pap test knowledge and awareness among Asian-Americans. The largest increase in likelihood to obtain a Pap test and recommend the test to others was the NUTD and 21-29 age groups, suggesting influence on those in need of screening.

Path selection for conformational interconversions in [2]catenanes.

[strucure: see text]The conformational interconversions of several [2]catenanes containing a dibenzo-34-crown-10 ether (BPP34C10) interlocked with rings containing two 4,4'-dipyridyls tethered by different aryl spacers have been studied. Blocking groups on the tethers enabled the two pathways for circumrotation of the BPP34C10 to be open or blocked. The activation barrier for migration along the open tethers varied from 11 to 13 kcal/mol. This study demonstrates an ability to select the pathway for conformational interconversions in [2]catenanes.