ABSTRACT
Background: We previously examined National Institutes of Health (NIH)-funded randomized controlled trials (RCTs) published in 2004, 2009, and 2015 and found low compliance with NIH policies on inclusion, analysis, and reporting results for female and minoritized subgroups, with no improvement over time. We conducted a fourth wave of data collection using RCTs published in 2021, comparing current results with previous years. Materials and Methods: The authors used PubMed to find 657 RCTs published in print in 14 leading US medical journals in 2021. Of those, 93 (14.2%) were eligible for analysis. We reviewed all parts of eligible studies and any published commentary. Fisher's exact statistics compared proportions of studies analyzing or reporting results for subgroups in 2021 compared with RCTs studied in previous waves. Posthoc analysis compared eligible RCTs about the Covid-19 pandemic to eligible RCTs on other topics. Results: Twenty-five of 93 studies (26.9%) analyzed or reported outcomes by race or ethnicity, an increase over previous years (p < 0.01). Among 79 RCTs with participants of both sexes, the median proportion of female participants was 43%. Moreover, 34 (43.0%) reported an outcome by sex, included sex as a covariate in statistical analysis, or reported results by sex, also an increase over previous waves (p < 0.01). Eleven eligible studies (11.8%) were on a SARS-CoV-2 topic; there was no difference between SARS-CoV-2 RCTs and RCTs on other topics. Conclusions: Analysis and reporting by sex, race, and ethnicity for NIH-funded RCTs published in 2021 significantly increased from previous waves, despite no corresponding increase in enrollment.
Subject(s)
COVID-19 , Ethnicity , Male , Female , Humans , Randomized Controlled Trials as Topic , Research Design , SARS-CoV-2ABSTRACT
Up until now, gas permeation through polymers under high pressure has not been able to be measured continuously. The combination of a special high pressure cell and a commercially available fluorescence-based oxygen measurement system allows in-situ monitoring of oxygen permeation through a polymer sample under pressure in an aqueous environment. The principle of the oxygen sensor is based on dynamic fluorescence quenching and measurement of the fluorescence decay time. It was observed that the decay time increases non-linearly with the applied pressure, and hence, the displayed oxygen concentration has to be corrected. This deviation between the measured and the real concentration depends not only on the pressure but also on the absolute oxygen concentration in the water. To obtain a calibration curve, tests were performed in the pressure range between 1 and 2000 bars and initial oxygen concentrations in the range between 40 and 280 µmol/l. The polynomial calibration curve was of the fourth order, describing the raw data with a coefficient of determination R(2) > 0.99. The effective oxygen permeation through polymeric samples can be calculated with this function. A pressure hysteresis test was undertaken but no hysteresis was found. No temperature dependence of the oxygen sensor signal was observed in the range between 20 °C and 30 °C. This study presents for the first time data showing the oxygen permeation rates through a polyethylene film in the pressure range between 1 and 2000 bars at 23 °C.
ABSTRACT
Pectin triggers formation of casein micro-particles during solution casting. Confocal Raman microscopy revealed their composition and spatial dimension in resulting films. Peaks in the Raman spectra corresponded to those found in films prepared by either casein or pectin. This suggested that no conformational changes occurred after mixing. Raman images revealed incompatibility of both polymers because particles consisted of casein only and the surrounding matrix of pectin. Deformation of micro-particles into an oblate shape took place during film formation. In dried films, an empty space between casein and pectin was found in lateral dimension. In contrast, casein micro-particles overlapped with the pectin matrix in the vertical dimension.
