Replicability is an important feature of scientific research, but aspects of contemporary research culture, such as an emphasis on novelty, can make replicability seem less important than it should ...be. The Reproducibility Project: Cancer Biology was set up to provide evidence about the replicability of preclinical research in cancer biology by repeating selected experiments from high-impact papers. A total of 50 experiments from 23 papers were repeated, generating data about the replicability of a total of 158 effects. Most of the original effects were positive effects (136), with the rest being null effects (22). A majority of the original effect sizes were reported as numerical values (117), with the rest being reported as representative images (41). We employed seven methods to assess replicability, and some of these methods were not suitable for all the effects in our sample. One method compared effect sizes: for positive effects, the median effect size in the replications was 85% smaller than the median effect size in the original experiments, and 92% of replication effect sizes were smaller than the original. The other methods were binary - the replication was either a success or a failure - and five of these methods could be used to assess both positive and null effects when effect sizes were reported as numerical values. For positive effects, 40% of replications (39/97) succeeded according to three or more of these five methods, and for null effects 80% of replications (12/15) were successful on this basis; combining positive and null effects, the success rate was 46% (51/112). A successful replication does not definitively confirm an original finding or its theoretical interpretation. Equally, a failure to replicate does not disconfirm a finding, but it does suggest that additional investigation is needed to establish its reliability.
Measurement of the dynamic kinetics involved in opening a jar may enable health care professionals to understand and train individuals in optimal hand/grip mechanics. This technical note details the ...design, validity, and reproducibility testing of a mimetic jar capable of measuring the forces and moments and isolated digital forces applied to the lid of the jar. An ecological jar instrument was designed with a torque limiter to provide a natural opening mechanism while a six-axis load cell and force sensing resistors recorded the way individuals applied force to the jar and lid during opening of a sealed container. A total of 115 volunteers participated in a validation of the device and an additional 36 participated in repeatability testing. Compared with prior instruments, this mimetic jar provides more force data and a simulated opening experience – making this jar instrument unique. Future studies utilizing the jar designed herein may allow health care professionals to evaluate patients suffering from debilitating osteoarthritis, fibromyalgia or other neuromuscular conditions and offer improvement strategies.
Conspectus Long-lived organic room-temperature phosphorescence (RTP) materials have recently drawn extensive attention because of their promising applications in information security, biological ...imaging, optoelectronic devices, and intelligent sensors. In contrast to conventional fluorescence, the RTP phenomenon originates from the slow radiative transition of triplet excitons. Thus, enhancing the intersystem crossing (ISC) rate from the lowest excited singlet state (S1) to the excited triplet state and suppressing the nonradiative relaxation channels of the lowest excited triplet state (T1) are reasonable methods for realizing highly efficient RTP in purely organic materials. Over the past few decades, many strategies have been designed on the basis of the above two crucial factors. The introduction of heavy atoms, aromatic carbonyl groups, and other heteroatoms with abundant lone-pair electrons has been demonstrated to strengthen the spin–orbit coupling, thereby successfully facilitating the ISC process. Furthermore, the rigid environment is commonly constructed through crystal engineering to restrict intramolecular motions and intermolecular collisions to decrease excited-state energy dissipation. However, most crystal-based organic RTP materials suffer from poor processability, flexibility, and reproducibility, becoming a thorny obstacle to their practical application. Amorphous organic polymers with long-lived RTP characteristics are more competitive in materials science. The intertwined structures and long chains of polymers not only ensure the rigid environment with multiple interactions but also protect triplet excitons from the surroundings, which are conducive to realizing ultralong and bright RTP emission. Exploring the fabrication strategies, intrinsic mechanisms, and practical applications of organic long-lived RTP polymers is highly desirable but remains a formidable challenge. In particular, intelligent organic RTP polymer systems that are capable of dynamically responding to external stimuli (e.g., light, temperature, oxygen, and humidity) have been rarely reported. To develop multifunctional RTP materials and expand their potential applications, a great amount of effort has been expended. This Account gives a summary of the significant advances in amorphous organic RTP polymer systems, especially smart stimulus-responsive ones, focusing on the construction of a rigid environment to suppress nonradiative deactivation by abundant inter/intramolecular interactions. The typical interactions in RTP polymer systems mainly include hydrogen bonding, ionic bonding, and covalent bonding, which can change the molecular electronic structures and affect the energy dissipation channels of the excited states. An in-depth understanding of intrinsic mechanisms and an extensive exploration of potential applications for excitation-dependent color-tunable, ultraviolet (UV) irradiation-activated, temperature-dependent, water-responsive, and circularly polarized RTP polymer systems are distinctly illustrated in this Account. Furthermore, we propose some detailed perspectives in terms of materials design, mechanism exploration, and promising application potential with the hope to provide helpful guidance for the future development of amorphous organic RTP polymers.
Purpose: 3-(6-methyl-pyridin-2-ylethynyl)-cyclohex-2-enone-O-11C-methyl-oxime (11C-ABP688) is a highly-selective antagonist PET tracer for imaging the metabotropic glutamate receptor subtype 5 ...(mGluR5). Test-Retest variability ranged from 7 to 14% for VT and 6 to 16% for BPND. incrementVT between test and retest was 2% or less on average in all regions, indicating no order effect in the absence of a challenge condition. incrementVT in cerebellum pre/post-NAC was 0.8±13.0%, indicating no effect of NAC in that region and supporting its use as a reference region. incrementBPND following NAC equaled or exceeded the T/RT variability in all regions except SMST.
Correction for 'Long-term repeatability improvement of quantitative LIBS using a two-point standardization method' by Zhongqi Hao
et al.
,
J. Anal. At. Spectrom.
, 2018,
33
, 1564-1570, DOI:
...10.1039/C8JA00148K
.
Objetivo: comparar la medida del área de úlceras venosas por medio de los softwares AutoCAD(r) e Image Tool. Método: se trata de un estudio de evaluación de reproducibilidad de pruebas, realizado en ...un ambulatorio de angiología de un hospital universitario. Los datos fueron recolectados de 21 pacientes con úlceras venosas, en el período de marzo a julio de 2015, por medio de formulario de recolección y fotografías de las heridas. Cinco enfermeros (evaluadores) del Grupo de Estudios de Lesiones de Piel del hospital participaron de la investigación. Las heridas fueron medidas en ambos softwares. Los datos fueron analizados por medio de: Coeficiente de correlación intraclase, Coeficiente de correlación de concordancia y Procedimiento de Bland y Altman. La investigación respetó los aspectos éticos de acuerdo con la legislación vigente. Resultados: los tamaños de las úlceras presentaron gran amplitud, sin embargo, sin diferencia significativa entre las medidas; existe excelente correlación intraclase y de concordancia entre los softwares, los que parecen ser más precisos en medidas de heridas con área > 10 cm². Conclusión: el uso de ambos softwares es indicado para medir úlceras venosas, pareciendo ser más precisos cuando utilizados para medir heridas con área > 10 cm².
The first results from the Reproducibility Project: Cancer Biology suggest that there is scope for improving reproducibility in pre-clinical cancer research.
The amino acid derivative reactivity assay (ADRA) is an in chemico alternative assay for skin sensitization listed in OECD test guideline 442C. ADRA evaluates the reactivity of sensitizers to ...proteins, which is key event 1 in the skin sensitization adverse outcome pathway.
Although the current key event 1 evaluation method is a simple assay that evaluates nucleophile and test chemical reactivity, mixtures of unknown molecular weights cannot be evaluated because a constant molar ratio between the nucleophile and test chemical is necessary. In addition, because the nucleophile is quantified by HPLC, the frequency of co‐eluting the test chemical and nucleophile increases when measuring multi‐component mixtures. To solve these issues, test conditions have been developed using a 0.5 mg/mL test chemical solution and fluorescence‐based detection. Since the practicality of these methods has not been substantiated, a validation test to confirm reproducibility was conducted in this study.
The 10 proficiency substances listed in the ADRA guidelines were tested three times at five different laboratories. The results of both within‐ and between‐laboratory reproducibility were 100%, and the results of ultraviolet‐ and fluorescence‐based measurements were also consistent. In addition to the proficiency substances, a new positive control, squaric acid diethyl ester, was tested three times at the five laboratories. The results showed high reproducibility with N‐(2‐(1‐naphthyl)acetyl)‐l‐cysteine depletion of 37%–52% and α‐N‐(2‐(1‐naphthyl)acetyl)‐l‐lysine depletion of 99%–100%.
Thus, high reproducibility was confirmed in both evaluations of the 0.5 mg/mL test chemical and the fluorescence‐based measurements, validating the practicability of these methods.
We implemented a study to validate a new amino acid derivative reactivity assay (ADRA) using a 0.5 mg/mL test chemical solution by determining within‐laboratory and between‐laboratory reproducibility in five participating laboratories. The aim of this study was to verify reproducibility with 10 proficiency substances and 1 positive control. The results showed sufficiently high reproducibility and predictive capacity. We plan to submit this new ADRA test method to the OECD test guideline group in the near future.
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