bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radon Concentrations in a Nuclear Reactor Center in Brazil
Authors: Cardoso da Silva Paulo Sergio , de Campos Marcia Pires , Mohamad El Hajj Thammiris , de Lima Reis Guilherme 
Published: May 2021

Abstract
Radiation workers are normally exposed to doses resulting from their day-to-day activities. Besides that, background radiation, such as radon, can contribute to the exposure rates. The radionuclide 222Rn is a noble gas belonging to the uranium series, and its indoor concentration in the air depends on the exhalation from surrounding soil and the exhalation from building materials. Radon exhaling from porous building materials containing high uranium concentrations can become a significant exposure factor in areas with limited ventilation. The objective of this study was to evaluate the 222Rn concentrations in the radiochemistry and radiometric laboratories in the nuclear reactor building of the Nuclear Reactor Center (CERPq) located in the Institute of Nuclear and Energy Research (IPEN), São Paulo, Brazil. Measurements were done using a Radon Gas Monitor, model RAD7, equipped with a solid-state alpha detector. A passive method (SSNTD) was also used, consisting of square pieces of C-39 foils (2.5 cm × 2.5 cm) placed within small diffusion chambers. The CR-39 detectors were etched in KOH 30% solution at 80 °C for 5.5 h in a constant-temperature bath. After etching, the detectors were washed, dried, and scanned using a microscope to obtain the track density measurements. The activity concentrations measured with both techniques varied from 52 to 103 Bq m−3 in the studied areas of the CERPq. These values may be compared to the reference level of 100 Bq m−3 established by the World Health Organization to ensure safety environments.
Postmortem Study of Cause of Death Among Children Hospitalized With Respiratory Illness in Kenya
Authors: Njuguna Henry N. , Zaki Sherif R. , Roberts Drucilla J. , Rogena Emily A. , Walong Edwin , Fligner Corinne L. , Keating M. Kelly , Gachii Andrew K. , Maleche-Obimbo Elizabeth , Irimu Grace , Mathaiya John , Orata Noelle , Lopokoiyit Rosemarie , Michuki Jackson , Emukule Gideon O. , Onyango Clayton O. , Gikunju Stella , Owuor Collins , Muturi Peter K. , Bunei Milka , Gloria Carvalho Maria , Fields Barry , Mott Joshua A. , Widdowson Marc-Alain , Chaves Sandra S. 
Published: May 2021

Background:
In resource-limited settings, acute respiratory infections continue to be the leading cause of death in young children. We conducted postmortem investigations in children <5 years hospitalized with a clinical diagnosis of respiratory disease at Kenya’s largest referral hospital.

Methods:
We collected respiratory and other tissues postmortem to examine pathologic processes using histology, molecular and immunohistochemistry assays. Nasopharyngeal, trachea, bronchi and lung specimens were tested using 21-target respiratory pathogen real-time reverse transcription polymerase chain reaction assays deployed on Taqman Array Cards. Expert panels reviewed all findings to determine causes of death and associated pathogens.

Results:
From 2014 to 2015, we investigated 64 pediatric deaths (median age 7 months). Pneumonia was determined as cause of death in 70% (42/52) of cases where death was associated with an infectious disease process. The main etiologies of pneumonia deaths were respiratory syncytial virus (RSV) (n = 7, 19%), Pneumocystis jirovecii (n = 7, 19%), influenza A (n = 5, 14%) and Streptococcus pneumoniae (n = 5, 14%)—10% of cases had multi-pathogen involvement. Among the other 10 deaths associated with a nonpneumonia infectious process, 4 did not have an etiology assigned, the others were associated with miliary tuberculosis (2), cerebral thrombosis due to HIV (1), Enterobacteriaceae (1), rotavirus (1), and 1 case of respiratory infection with severe hypokalemia associated with RSV.

Conclusions:
In spite of well-established vaccination programs in Kenya, some deaths were still vaccine preventable. Accelerated development of RSV monoclonal antibodies and vaccines, introduction of seasonal influenza vaccination, and maintenance or improved uptake of existing vaccines can contribute to further reductions in childhood mortality.
The Physician Assistant Student Experience: Diversity, Stress, and School Membership
Authors: Frias Dominique , Yuen Cynthia X. 
Published: May 2021

Purpose
This article investigates whether students' stress and psychological sense of school membership (PSSM), which influence their ability to navigate the rigors of PA education, vary by their demographic characteristics.

Methods
In 2017, 4050 matriculating and 2718 graduating PA students reported their demographics and feelings of stress. Graduating students also reported their PSSM. Multiple regressions explored whether students' demographics were associated with their stress and PSSM. Stress analyses controlled for student type (ie, matriculating versus graduating).

Results
Female, underrepresented minority (URM), and graduating students reported more stress when compared to male, non-URM, and matriculating students. URM students reported lower PSSM relative to non-URMs.

Conclusion
URM students' experiences from entering a profession that is predominantly non-Hispanic White may increase stress and reduce PSSM, possibly contributing to lower educational satisfaction and on-time completion rates identified in previous research.
Cardiac Troponin-T Release After Sport and Differences by Age, Sex, Training Type, Volume, and Intensity: A Critical Review
Authors: Cantinotti Massimiliano , Clerico Aldo , Giordano Raffaele , Assanta Nadia , Franchi Eliana , Koestenberger Martin , Marchese Pietro , Storti Simona , D'Ascenzi Flavio 
Published: May 2021

Background:
Postexercise release of cardiac troponin (cTn) is a well-known phenomenon, although the influence of various confounders remains unclear. The aim of this critical review was to analyze the postexercise release of cTn according to age, sex, different types of sport, exercise intensity and duration, and training level.

Data Sources:
A literature search was performed within the National Library of Medicine using the following keywords: cTn, peak, release, and exercise. The search was further refined by adding the keywords athletes, children/adolescents, and sport.

Main Results:
For final analysis, 52 studies were included: 43 adult studies, 4 pediatric studies, and 5 with a mixed population of adults and children. Several studies have investigated the kinetics of cTn response after exercise with different biomarkers. The current evidence suggests that sport intensity and duration have significant effects on postexercise cTn elevation, whereas the influence of the type of sport, age, and sex have been not completely defined yet. Most data were obtained during endurance races, whereas evidence is limited (or almost absent), particularly for mixed sports. Data on young adults and professional athletes are limited. Finally, studies on women are extremely limited, and those for non-White are absent.

Conclusions:
Postexercise release of cTn can be observed both in young and master athletes and usually represents a physiological phenomenon; however, more rarely, it may unmask a subclinical cardiac disease. The influence of different confounders (age, sex, sport type/intensity/duration, and training level) should be better clarified to establish individualized ranges of normality for postexercise cTn elevation.
Methamphetamine Use, Syphilis, and Specific Online Sex Partner Meeting Venues Are Associated With HIV Status Among Urban Black Gay and Bisexual Men Who Have Sex Men
Authors: Jennings Jacky M. , Wagner Jessica , Tilchin Carla , Schumacher Christina M. , Thornton Nicole , Hamill Matthew M. , Rompalo Anne , Ruhs Sebastian , Rives Sarah , Ghanem Khalil G. , Latkin Carl 
Published: May 2021

Background
In the context of increasing syphilis rates, particularly among Black men who have sex men (MSM), the objectives were to determine the associations between methamphetamine (meth) use and syphilis and HIV positivity, and to identify sex partner meeting venues as potential intervention access points among Black MSM in a mid-Atlantic US city.

Methods
This study is an ongoing longitudinal cohort study. Participants were recruited from clinical and nonclinical settings and included sexually active MSM aged 18 to 45 years. The baseline visit included a behavioral survey and testing for syphilis, HIV, gonorrhea, and chlamydia. Logistic regression analyses were used for hypothesis testing.

Results
Among 359 MSM completing baseline, 74.4% (268) Black MSM were included; 31% (84) were aged 24 to 29 years, 43.7% (117) reported unprotected anal intercourse at last sex, and 15.3% (41) reported meth use in the past 3 months. Sixteen percent (43) had syphilis, 46.6% (125) were living with HIV, and 19.0% (51) had gonorrhea and/or chlamydia. Meth use was associated with sexual and drug risk behaviors and HIV, but not syphilis. In adjusted analyses, meth use increased the odds of HIV positivity by 6.43 (95% confidence interval, 2.30–17.98) and syphilis positivity by 2.57 (95% confidence interval, 1.23–5.37). Four online sex partner meeting venues were associated with meth use and HIV, whereas syphilis was associated with one.

Conclusions
Among Black MSM, meth use and syphilis positivity were associated with more than 6-fold and almost 3-fold increased adjusted odds of HIV positivity, respectively. Four specific sex partner meeting venues may be important access points for HIV/sexually transmitted infection and substance use prevention.
Can Diagnostic Codes in Health Care Claims Data Identify Confirmed Chlamydial and Gonococcal Infections? A Retrospective Cohort Study, 2003 to 2017
Authors: Mauk Kerry C. , Torrone Elizabeth A. , Flagg Elaine W. 
Published: May 2021

Background
Because most sources of administrative claims data do not contain laboratory result data, researchers rely on diagnosis codes to identify cases of disease. The validity of using diagnosis codes to identify chlamydial and gonococcal infections in administrative claims data remains largely uninvestigated.

Methods
We conducted a retrospective cohort analysis using OptumLabs Data Warehouse, which includes deidentified medical (inpatient and outpatient) claims and laboratory test results. Among males and females aged 15 to 39 years during the period 2003–2017, we identified chlamydia and gonorrhea test results and corresponding diagnosis codes. Using test results as the criterion standard, we calculated the sensitivity and specificity of chlamydia and gonorrhea diagnosis codes to identify laboratory-confirmed infections.

Results
We identified 9.7 million chlamydia and gonorrhea test results among 3.1 million enrollees. Of the 176,241 positive chlamydia test results, only 11,515 had a corresponding diagnosis code, for a sensitivity of 6.5 (95% confidence interval [CI], 6.4–6.7) and a specificity of 99.5 (95% CI, 99.5–99.5). Corresponding diagnosis codes were identified for 8056 of the 31,766 positive gonorrhea test results, for a sensitivity of 25.4 (95% CI, 24.9–25.8) and a specificity of 99.7 (95% CI, 99.7–99.7).

Conclusions
Our findings indicate that using only International Classification of Diseases, Ninth and Tenth Revisions, Clinical Modification diagnosis codes to identify chlamydial and gonococcal infections substantially underestimates the burden of these diseases and inaccurately classifies laboratory-confirmed infections.
Assessing the Burden of Infant Deaths Due to Herpes Simplex Virus, Human Immunodeficiency Virus, and Congenital Syphilis: United States, 1995 to 2017
Authors: Slutsker Jennifer Sanderson , Schillinger Julia A. 
Published: May 2021

Background
Despite advances in diagnosis and treatment, neonatal infection with herpes simplex virus (HSV) has a high case fatality rate. The national burden of neonatal HSV and associated deaths is unknown because this condition is not nationally notifiable. We investigated trends in HSV-related infant deaths compared with infant deaths from congenital syphilis (CS) and human immunodeficiency virus (HIV).

Methods
Linked birth-death files for infant deaths from 1995 to 2017 were obtained from the National Center for Health Statistics. These files include infants who were born alive and died in the first 365 days of life and exclude stillbirths. We searched death certificates for disease codes indicating HSV, CS, or HIV, and calculated the frequency and rate of deaths for each infection, overall, by infant sex, and birthing parent age and race/ethnicity.

Results
Nationally, 1591 deaths related to the infections of interest were identified: 1271 related to HSV (79.9%), 234 to HIV (14.7%), and 86 to CS (5.4%). Herpes simplex virus–related deaths increased significantly from 0.83/100,000 live births (95% confidence interval [CI], 0.57–1.17) in 1995 to 1.77 (95% CI, 1.37–2.24) in 2017. In contrast, HIV-related deaths declined: 1.64/100,000 (95% CI, 1.27–2.10) in 1995 to 0.00 in 2017. There was a median of 3 CS-related deaths/year, with elevated frequencies in 1995 to 1996 and 2017 (n = 8). Herpes simplex virus–related death rates were elevated among infants born to birthing parents younger than 20 years (4.17/100,000; 95% CI, 3.75–4.59) and to Black parents (2.86/100,000; 95% CI, 2.58–3.15).

Conclusions
Nationally, HSV-related infant deaths exceeded those caused by HIV and CS and seem to be increasing. Our findings underscore the need for an effective HSV vaccine, test technologies enabling rapid identification of infants exposed to HSV at delivery, and a focus on equity in prevention efforts.
Case Report: Modified Piggyback System to Treat Peripheral Iridotomies and Degenerative Myopia
Authors: Nadarajah Vakishan 
Published: May 2021

SIGNIFICANCE
This report details how a case with degenerative myopia and symptoms secondary to laser peripheral iridotomies is managed with a modified piggyback contact lens system. The benefits of using a system with tinted and gas-permeable (GP) lenses are discussed.

PURPOSE
This study aimed to report the positive outcome of a modified piggyback system in the treatment of degenerative myopia and iris abnormalities.

CASE REPORT
A patient with degenerative myopia presented with visual disturbances secondary to laser peripheral iridotomies in both eyes. A modified piggyback system was trialed using a corneal GP lens overlaying a tinted soft contact lens to provide optimal vision and visual comfort in both eyes. After optimizing the fit, there was a reduction in glare and improved vision.

CONCLUSIONS
Hard contact lenses often provide superior optics and vision compared with soft lenses, especially to patients with high refractive errors. Patients who require hard lenses and also have visual disturbances secondary to iris abnormalities could be managed with a modified piggyback contact lens systems using a corneal GP lens and tinted soft lens.
Visual Performance with Spherical and Multifocal Contact Lenses in a Pediatric Population
Authors: Bickle Katherine M. , Mitchell G. Lynn , Walline Jeffrey J. 
Published: May 2021

SIGNIFICANCE
This pilot study compared subjective and objective vision of children wearing single-vision and +2.00, +3.00, and +4.00 D add power soft multifocal contact lenses to determine whether the higher add power—thought to provide better myopia control—resulted in visual compromise.

PURPOSE
This study aimed to determine the maximum add power children wearing center-distance soft multifocal contact lenses could accept objectively and subjectively.

METHODS
Myopic children were assigned in random order to wear omafilcon A single-vision or multifocal “D” contact lenses with +2.00, +3.00, or +4.00 D add power for 1 week each. High-contrast distance and near visual acuity, low-contrast distance visual acuity, and contrast sensitivity were measured at each visit along with a quality of vision questionnaire to assess their vision. The Friedman test was performed to evaluate the impact of add power on all outcome measures.

Results
Eleven subjects were enrolled, and nine subjects completed the study. The median age of completed subjects was 11 years. Median logMAR low-contrast distance visual acuity was reduced in the +3.00 (+0.20) and +4.00 (+0.28) D add lenses compared with the +2.00 (+0.16) D add and single-vision lenses (+0.10, P < .001). All three multifocal lenses resulted in reduced contrast sensitivity (+1.35 to +1.40) compared with single-vision lenses (+1.60, P < .001). In general, +3.00 and +4.00 D add lenses resulted in worse glare/starbursts, ghost images, computer vision, changing fixation distance, and overall vision, but results varied. There were no differences among the lenses with respect to subjective assessments of distance vision, near vision, strain or tiredness, contact lens comfort, or sporting activities.

CONCLUSIONS
The +3.00 D and higher add powers result in more objective and subjective vision-related issues than single-vision lenses, but the +2.00 D add multifocal lenses were well tolerated.
Development and Evaluation of Deep Learning-Accelerated Single-Breath-Hold Abdominal HASTE at 3 T Using Variable Refocusing Flip Angles
Authors: Herrmann Judith , Nickel Dominik , Mugler John P. , Arberet Simon , Gassenmaier Sebastian , Afat Saif , Nikolaou Konstantin , Othman Ahmed E. 
Published: May 2021

Objective
Deep learning (DL) reconstruction enables substantial acceleration of image acquisition while maintaining diagnostic image quality. The aims of this study were to overcome the drawback of specific absorption rate (SAR)–related limitations at 3 T and to develop a DL-accelerated single-breath-hold half-Fourier acquisition single-shot turbo spin echo (HASTE) sequence for 2-dimesional T2-weighted fat-suppressed magnetic resonance imaging of the abdomen at 3 T using a variable flip angle (FA) evolution for the refocusing radiofrequency pulses, as well as to evaluate its feasibility and image quality in comparison to state-of-the-art T2-weighted fat-suppressed imaging technique (BLADE).

Materials and Methods
First, a suitable FA evolution with low cardiac motion–related signal loss (CRSL) and low SAR was determined through a prospective volunteer study with 11 participants. Image quality and diagnostic confidence with 5 different FA evolutions of a HASTEDL were assessed to identify the most suitable FA evolution. Second, the identified FA evolution was implemented clinically and evaluated in 51 patients undergoing a clinically indicated liver magnetic resonance imaging at 3 T. Two radiologists assessed the HASTEDL and standard sequences regarding overall image quality, noise, contrast, sharpness, artifacts, CRSL, and diagnostic confidence using a Likert scale ranging from 1 to 4, with 4 being the best. Comparative analyses were conducted to assess the differences between HASTEDL (acquisition time, 21 seconds; single breath-hold) and the routinely used T2-weighted BLADE sequence (acquisition time, 4 minutes; respiratory triggering).

Results
From the volunteer study, the FA evolution characterized by the control points 130-90-110-130 degrees (HASTEDL) was identified as optimal among the 5 evolutions evaluated and was implemented in our clinical protocol. In all 51 patients, HASTEDL was successfully acquired at 3 T and showed excellent image quality (median, 4; interquartile range, 3–4). Although BLADE was rated significantly higher for overall image quality, noise, contrast, sharpness, artifacts, CRSL, and diagnostic confidence than HASTEDL, no differences were found concerning the number (n = 102) and measured diameter of the detected hepatic lesions between the 2 sequences BLADE and HASTEDL.

Conclusions
The proposed single-breath-hold abdominal HASTEDL with variable refocusing FAs is feasible at 3 T within SAR limits and yields high image quality and diagnostic confidence as compared with a standard T2-weighted acquisition technique, at a 10th of the acquisition time.
Guidelines for Perioperative Care for Liver Transplantation: Enhanced Recovery After Surgery (ERAS) Recommendations
Authors: Brustia Raffaele , Monsel Antoine , Skurzak Stefano , Schiffer Eduardo , Carrier François Martin , Patrono Damiano , Kaba Abdourahamane , Detry Olivier , Malbouisson Luiz , Andraus Wellington , Vandenbroucke-Menu Franck , Biancofiore Gianni , Kaido Toshimi , Compagnon Philippe , Uemoto Shinji , Rodriguez Laiz Gonzalo , De Boer Marieke , Orloff Susan , Melgar Paola , Buis Carlijn , Zeillemaker-Hoekstra Miriam , Usher Helen , Reyntjens Koen , Baird Emily , Demartines Nicolas , Wigmore Stephen , Scatton Olivier 
Published: May 2021

Background.
Enhanced Recovery After Surgery (ERAS) is a multimodal, evidence-based, program of care developed to minimize the response to surgical stress, associated with reduced perioperative morbidity and hospital stay. This study presents the specific ERAS Society recommendations for liver transplantation (LT) based on the best available evidence and on expert consensus

Methods.
PubMed and ClinicalTrials.gov were searched in April 2019 for published and ongoing randomized clinical trials on LT in the last 15 y. Studies were selected by 5 independent reviewers and were eligible if focusing on each validated ERAS item in the area of adult LT. An e-Delphi method was used with an extended interdisciplinary panel of experts to validate the final recommendations.

Results.
Forty-three articles were included in the systematic review. A consensus was reached among experts after the second round. Patients should be screened for malnutrition and treated whenever possible. Prophylactic nasogastric intubation and prophylactic abdominal drainage may be omitted, and early extubation should be considered. Early oral intake, mobilization, and multimodal-balanced analgesia are recommended.

Conclusions.
The current ERAS recommendations were elaborated based on the best available evidence and endorsed by the e-Delphi method. Nevertheless, prospective studies need to confirm the clinical use of the suggested protocol.