Background Preprints are publicly available manuscripts posted to various servers that have not been peer reviewed. Although preprints have existed since 1961, they have gained increased popularity during the COVID-19 pandemic due to the need for immediate, relevant information. Objective The aim of this study is to evaluate the publication rate and impact of preprints included in the Centers for Disease Control and Prevention (CDC) COVID-19 Science Update and assess the performance of the COVID-19 Science Update team in selecting impactful preprints. Methods All preprints in the first 100 editions (April 1, 2020, to July 30, 2021) of the Science Update were included in the study. Preprints that were not published were categorized as “unpublished preprints.” Preprints that were subsequently published exist in 2 versions (in a peer-reviewed journal and on the original preprint server), which were analyzed separately and referred to as “peer-reviewed preprint” and “original preprint,” respectively. Time to publish was the time interval between the date on which a preprint was first posted and the date on which it was first available as a peer-reviewed article. Impact was quantified by Altmetric Attention Score and citation count for all available manuscripts on August 6, 2021. Preprints were analyzed by publication status, publication rate, preprint server, and time to publication. Results Of the 275 preprints included in the CDC COVID-19 Science Update during the study period, most came from three servers: medRxiv (n=201, 73.1%), bioRxiv (n=41, 14.9%), and SSRN (n=25, 9.1%), with 8 (2.9%) coming from other sources. Additionally, 152 (55.3%) were eventually published. The median time to publish was 2.3 (IQR 1.4-3.7). When preprints posted in the last 2.3 months were excluded (to account for the time to publish), the publication rate was 67.8%. Moreover, 76 journals published at least one preprint from the CDC COVID-19 Science Update, and 18 journals published at least three. The median Altmetric Attention Score for unpublished preprints (n=123, 44.7%) was 146 (IQR 22-552) with a median citation count of 2 (IQR 0-8); for original preprints (n=152, 55.2%), these values were 212 (IQR 22-1164) and 14 (IQR 2-40), respectively; for peer-review preprints, these values were 265 (IQR 29-1896) and 19 (IQR 3-101), respectively. Conclusions Prior studies of COVID-19 preprints found publication rates between 5.4% and 21.1%. Preprints included in the CDC COVID-19 Science Update were published at a higher rate than overall COVID-19 preprints, and those that were ultimately published were published within months and received higher attention scores than unpublished preprints. These findings indicate that the Science Update process for selecting preprints had a high fidelity in terms of their likelihood to be published and their impact. The incorporation of high-quality preprints into the CDC COVID-19 Science Update improves this activity’s capacity to inform meaningful public health decision-making.

Significance: For use in medical balloons and related clinical applications, polymers are usually designed for transparency under illumination with white-light sources. However, when illuminated with ultraviolet (UV) or blue light, most of these materials autofluoresce in the visible range, which can be a concern for modalities that rely on tissue autofluorescence for diagnostic or therapeutic purposes. Aim: A search for published information on spectral properties of polymers that can be used for medical balloon manufacturing revealed a scarcity of published information on this subject. The aim of these studies was to address this gap. Approach: The autofluorescence properties of polymers used in medical balloon manufacturing were examined for their suitability for hyperspectral imaging and related applications. Excitation-emission matrices of different balloon materials were acquired within the 320-to 620-nm spectral range. In parallel, autofluorescence profiles from the 420-to 620-nm range were extracted from hyperspectral datasets of the same samples illuminated with UV light. The list of tested polymers included polyurethanes, nylon, polyethylene terephthalate (PET), polyether block amide (PEBAX), vulcanized silicone, thermoplastic elastomers with and without talc, and cyclic olefin copolymers, known by their trade name TOPAS. Results: Each type of polymer exhibited a specific pattern of autofluorescence. Polyurethanes, PET, and thermoplastic elastomers containing talc had the highest autofluorescence values, while sheets made of nylon, PEBAX, and TOPAS exhibited negligible autofluorescence. Hyperspectral imaging was used to illustrate how the choice of specific balloon material can impact the ability of principal component analysis to reveal the ablated cardiac tissue. Conclusions: The data revealed significant differences between autofluorescence profiles of the polymers and pointed to the most promising balloon materials for clinical implementation of approaches that depend on tissue autofluorescence.

BACKGROUND Preprints are publicly available manuscripts posted to various servers that have not been peer-reviewed. Although preprints have existed since 1961, they have gained increased popularity and credibility during the COVID-19 pandemic due to the need for immediate, relevant information. OBJECTIVE The inclusion of preprints in the CDC COVID-19 Science Update, a weekly publication that provides brief summaries of new COVID-19-related studies, is an opportunity to evaluate the publication rate and impact (Altmetric Attention Score and citation count) of selected preprints and assess the performance of the Science Update to select impactful preprints. METHODS All preprints in the first 100 editions (April 1, 2020 – July 30, 2021) of the Science Update were included in the study. Preprints that were not published were categorized as “unpublished preprints”. Preprints that were subsequently published exist in two versions (in a peer-reviewed journal and on the original preprint server) which were analyzed separately and referred to as “peer-reviewed preprint” and “original preprint”, respectively. Time-to-publish was the time interval between the date on which a preprint was first posted to the date on which it was first available as a peer-reviewed article. Impact was quantified by Altmetric Attention Score and citation count for all available manuscripts on August 6, 2021. Preprints were analyzed by publication status, rate, and time to publication. RESULTS Among 275 preprints included in the CDC COVID-19 Science Update during the study period, most came from three servers: medRxiv (n=201), bioRxiv (n=41), and SSRN (n=25), with eight coming from other sources. More than half (55.3%) were eventually published. The median time-to-publish was 2.31 months (IQR 1.38-3.73). When preprints posted in the last 2.31 months were excluded (to account for the time-to-publish), the publication rate was to 67.8%. Seventy-six journals published at least one preprint from the CDC COVID-19 Science Update and 18 journals published at least three. The median Altmetric Attention Score for unpublished preprints (n=123) was 146 (IQR 22-552) and median citation count of 2 (IQR 0-8); for original preprints (n=152) these values were 212 (IQR 22-1164) and 14 (IQR 2-40), respectively. For peer-review preprints, these values were 265 (IQR 29-1896) 19 (IQR 3-101), respectively. CONCLUSIONS Prior studies of COVID-19 preprints found publication rates between 5.4% and 21.1%. Preprints included in the CDC COVID-19 Science Update were published at a higher rate than overall COVID-19 preprints, and those that were ultimately published were published within months and received higher attention scores than unpublished preprints. These findings indicate that the Science Update process for selecting preprints appears have done so with high fidelity in terms of their likelihood to be published and impactful. Incorporation of high-quality preprints into the CDC COVID-19 Science Update improves this activity’s capacity to inform meaningful public health decision making.

Purpose: Gender disparities among the senior echelons of academic medicine are striking and persistent. The role of medical school dean has been particularly immune to gender diversity, and limited prior research identified women’s shorter decanal tenures as a potential driver. The authors assessed gender differences in tenure length of deanships in the current era to elucidate this finding. Method; From October 2020 to June 2021, the authors collected information about medical school deanships that were held from January 1, 2006, to June 30, 2020. All schools were members of the Association of American Medical Colleges (AAMC). The authors collected data from online public records and augmented their findings via direct outreach to medical schools. They used time to event analyses before and after adjustment for interim vs permanent status of the initial appointment, school ownership (public/private), and school size to assess for gender differences in length of deanship tenure during the study period. The unit of analysis was deanships, and the primary outcome was length of deanships measured in years. Results: Authors included data on 528 deanships. Women held 91 (17%) of these terms. Men held the majority of permanent deanships (n = 352 [85%]). A greater percentage of the deanships held by women were interim only (n = 27 [30%]) compared with men (n = 85 [20%]). In unadjusted and adjusted analyses, there were no significant gender differences in length of deanship tenures. Conclusions: Analysis of appointments of AAMC-member medical school deans from 2006 to 2020 revealed that women have remained in their deanships as long their male counterparts. The myth about women deans’ shorter longevity should no longer be promulgated. Academic medicine should consider novel solutions to addressing women’s persistent underrepresentation in the dean role, including employing the gender proportionality principle used in the business and legal communities.