Reframing the perception of outliers and negative data in translational research

Negative results can be a source of disappointment for scientists, yet their publication is needed for scientific progress, in particular for cutting-edge translational research of novel therapeutics. This manuscript is directed to scientists, junior and senior, that produce and review data for publication. It discusses the difference between 'negative' or 'unexpected' data and 'useless' data, re-evaluates the importance of the experimental design to generate valuable data and proposes strategies to work with and report negative results. Overall, it aims to reframe the perception of working with, reporting and reviewing unexpected data as an opportunity to provide rationale for innovative ideas, prevent the misuse of limited resources and, ultimately, strengthen the reputation of a scientist.

Design and Analysis of Massively Parallel Reporter Assays Using FORECAST

Machine learning is revolutionizing molecular biology and bioengineering by providing powerful insights and predictions. Massively parallel reporter assays (MPRAs) have emerged as a particularly valuable class of high-throughput technique to support such algorithms. MPRAs enable the simultaneous characterization of thousands or even millions of genetic constructs and provide the large amounts of data needed to train models. However, while the scale of this approach is impressive, the design of effective MPRA experiments is challenging due to the many factors that can be varied and the difficulty in predicting how these will impact the quality and quantity of data obtained. Here, we present a computational tool called FORECAST, which can simulate MPRA experiments based on fluorescence-activated cell sorting and subsequent sequencing (commonly referred to as Flow-seq or Sort-seq experiments), as well as carry out rigorous statistical estimation of construct performance from this type of experimental data. FORECAST can be used to develop workflows to aid the design of MPRA experiments and reanalyze existing MPRA data sets.

Processability of mesoporous materials in fused deposition modeling for drug delivery of a model thermolabile drug

The incorporation of drug-loaded mesoporous materials in dosage forms prepared with fused deposition modeling (FDM) has shown the potential to solve challenges relating to additive manufacturing techniques, such as the stability of poorly-soluble drugs in the amorphous state. However, the addition of these non-melting mesoporous materials significantly affects the mechanical properties of the filament used in FDM, which in turn affects the printability of the feedstock material. Therefore, in this study a full-factorial experimental design was utilized to investigate different processing parameters of the hot melt extrusion process, their effect on various mechanical properties and the potential correlation with the filaments' printability. The thermolabile, poorly-soluble drug ibuprofen was utilized as a model drug to assess the potential of two mesoporous materials, Mesoporous Magnesium Carbonate (MMC) and a silica-based material (MCM-41), to thermally protect the loaded drug. Factorial and principal components analysis displayed a correlation between non-printable MCM-41 filaments and their mechanical properties where printable filaments had a maximum stress >7.5 MPa and a Young's modulus >83 MPa. For MMC samples there was no clear correlation, which was in large part attributed to the filaments' inconsistencies and imperfections. Finally, both mesoporous materials displayed a thermal protective feature, as the decomposition due to the thermal degradation of a significant portion of the thermolabile drug was shifted to higher temperatures post-loading. This highlights the potential capability of such a system to be implemented for thermosensitive drugs in FDM applications.

Efficiency in sequential testing: Comparing the sequential probability ratio test and the sequential Bayes factor test

In a sequential hypothesis test, the analyst checks at multiple steps during data collection whether sufficient evidence has accrued to make a decision about the tested hypotheses. As soon as sufficient information has been obtained, data collection is terminated. Here, we compare two sequential hypothesis testing procedures that have recently been proposed for use in psychological research: Sequential Probability Ratio Test (SPRT; Psychological Methods, 25(2), 206-226, 2020) and the Sequential Bayes Factor Test (SBFT; Psychological Methods, 22(2), 322-339, 2017). We show that although the two methods have different philosophical roots, they share many similarities and can even be mathematically regarded as two instances of an overarching hypothesis testing framework. We demonstrate that the two methods use the same mechanisms for evidence monitoring and error control, and that differences in efficiency between the methods depend on the exact specification of the statistical models involved, as well as on the population truth. Our simulations indicate that when deciding on a sequential design within a unified sequential testing framework, researchers need to balance the needs of test efficiency, robustness against model misspecification, and appropriate uncertainty quantification. We provide guidance for navigating these design decisions based on individual preferences and simulation-based design analyses.

Hydra bioassay for the evaluation of chlordecone toxicity at environmental concentrations, alone or in complex mixtures with dechlorinated byproducts: experimental observations and modeling by experimental design

In chlordecone (CLD)-contaminated soils of the French West Indies, if microbial remediation or a physicochemical remediation process, e.g., in situ chemical reduction, is implemented, concentrations of degradation byproducts, such as hydrochlordecones, are expected to increase in the ecosystems. To study their impact in mixtures with CLD, bioassays were carried out. They consisted in evaluating the regenerative capacity of hydra polyps, from a clone whose phylogenetic analysis confirmed that it belonged to the species Hydra vulgaris Pallas, 1766. Hydra gastric sections were exposed to CLD alone or CLD plus dechlorinated byproducts (CLD-BP) for 96 h to assess regeneration. Based on chromatographic analysis, the CLD-BP mix was composed of the 5-monohydrochlordecone isomer (CAS nomenclature), four dihydrochlordecone isomers, and one trihydrochlordecone isomer representing 50%, 47%, and 3% of the total chromatographic area, respectively. A total of 18 mixtures of CLD and CLD-BP were tested. Six environmental concentrations of CLD (2.10^-4 μM to 4.10^-2 μM) and a similar range of CLD-BP were used. Results from exposures to CLD alone showed the following: (i) a significant decrease in the regenerative capacity of hydra, except at the lowest concentration (2.10^-4 μM); (ii) a concentration-independent deleterious effect. The regeneration scores obtained after the exposure to the addition of CLD-BP were not significantly different from those obtained after exposure to CLD alone. Using an experimental design, a modeling of the regeneration scores of hydra exposed to mixtures is proposed. Interpreted carefully, since they are limited to only one type of bioassay, the present results suggest that the situation in the aquatic environments should not become worse in terms of toxicity, if soil remediation programs resulting in the formation of hydrochlordecones are put in place.

Remarkably reproducible psychological (memory) phenomena in the classroom: some evidence for generality from small-N research

BACKGROUND

Mainstream psychology is experiencing a crisis of confidence. Many of the methodological solutions offered in response have focused largely on statistical alternatives to null hypothesis statistical testing, ignoring nonstatistical remedies that are readily available within psychology; namely, use of small-N designs. In fact, many classic memory studies that have passed the test of replicability used them. That methodological legacy warranted a retrospective look at nonexperimental data to explore the generality of the reported effects.

METHOD

Various classroom demonstrations were conducted over multiple semesters in introductory psychology courses with typical, mostly freshman students from a predominantly white private Catholic university in the US Midwest based on classic memory experiments on immediate memory span, chunking, and depth of processing.

RESULTS

Students tended to remember 7 ± 2 digits, remembered more digits of π following an attached meaningful story, and remembered more words after elaborative rehearsal than after maintenance rehearsal. These results amount to replications under uncontrolled classroom environments of the classic experiments originally conducted largely outside of null hypothesis statistical testing frameworks.

CONCLUSIONS

In light of the ongoing replication crisis in psychology, the results are remarkable and noteworthy, validating these historically important psychological findings. They are testament to the reliability of reproducible effects as the hallmark of empirical findings in science and suggest an alternative approach to commonly proffered solutions to the replication crisis.

Multivariate optimization approach applied to natural polymers from Ceratonia siliqua L. and Moringa oleifera Lam as coagulating/flocculating agents

In this study, a multivariate 23 experimental design was applied to optimize the operational conditions (seed mass, salt concentration, and pH) to employ Ceratonia siliqua L. (carob) and Moringa oleifera Lam (moringa) as coagulating/flocculating agents for water treatment. Currently, the coagulation stage in water treatment uses aluminium compounds, due to the characteristic reaction to natural alkalinity in raw water, and for its low market value. Considering that aluminium effects on human health are not sufficiently studied to acknowledge its toxicity, and its significant environmental impacts, it is suitable for the studies to search for alternatives to be employed in the water treatment that will be distributed to human consumption. This study was carried out with raw water of high turbidity level, 83.7 NTU. The raw water collected was also characterized according to pH, colour, Total Organic Carbon (TOC), Dissolved Organic Carbon (DOC), and Dissolved Organic Matter (DOM), with values of 6.7, 178 NTU, 6.80, 2.45 and 138.58 mg/L, respectively. The optimized results showed that with 2 g of seed, 0.5 mol L-1 of NaCl, and pH 11.0 In these conditions, moringa coagulant reached 90%, 86%, 6%, 67%, and 81% for turbidity, colour, DOC, TOC, and DOM removal, respectively, whereas the carob coagulant achieved 85%, 76%, 5%, 55.6%, 66.7%, respectively for the same parameters' removal. Both coagulants presented lower sludge formation, 1.1 mL L^-1 for moringa coagulant, and 1.1 mL L^-1 for carob coagulant. The results could be considered promises, and natural polymers carob and moringa can be suggested as alternatives agents in coagulation/flocculation stages for water treatment.

Understanding the importance of quality control and quality assurance in preclinical PET/CT imaging

The fundamental principle of experimental design is to ensure efficiency and efficacy of the performed experiments. Therefore, it behoves the researcher to gain knowledge of the technological equipment to be used. This should include an understanding of the instrument quality control and assurance requirements to avoid inadequate or spurious results due to instrumentation bias whilst improving reproducibility. Here, the important role of preclinical positron emission tomography/computed tomography and the scanner's required quality control and assurance is presented along with the suggested guidelines for quality control and assurance. There are a multitude of factors impeding the continuity and reproducibility of preclinical research data within a single laboratory as well as across laboratories. A more robust experimental design incorporating validation or accreditation of the scanner performance can reduce inconsistencies. Moreover, the well-being and welfare of the laboratory animals being imaged is prime justification for refining experimental designs to include verification of instrumentation quality control and assurance. Suboptimal scanner performance is not consistent with the 3R principle (Replacement, Reduction, and Refinement) and potentially subjects animals to unnecessary harm. Thus, quality assurance and control should be of paramount interest to any scientist conducting animal studies. For this reason, through this work, we intend to raise the awareness of researchers using PET/CT regarding quality control/quality assurance (QC/QA) guidelines and instil the importance of confirming that these are routinely followed. We introduce a basic understanding of the PET/CT scanner, present the purpose of QC/QA as well as provide evidence of imaging data biases caused by lack of QC/QA. This is shown through a review of the literature, QC/QA accepted standard protocols and our research. We also want to encourage researchers to have discussions with the PET/CT facilities manager and/or technicians to develop the optimal designed PET/CT experiment for obtaining their scientific objective. Additionally, this work provides an easy gateway to multiple resources not only for PET/CT knowledge but for guidelines and assistance in preclinical experimental design to enhance scientific integrity of the data and ensure animal welfare.

Formulation of intranasal surface engineered nanostructured lipid carriers of rotigotine: Full factorial design optimization, in vitro characterization, and pharmacokinetic evaluation

The objective of the present research was to develop, optimize, and evaluate rotigotine (RT)-loaded chitosan (CH) coated nanostructured lipid carriers (RT-CH-NLCs) for nose-to-brain delivery. The NLCs were prepared by homogenization and sonication technique as well as optimized by using three factors at three-level Box-Behnken design. The prepared NLCs were evaluated for particle size, zeta potential, entrapment efficiency, drug release, and ex vivo permeation. The pharmacokinetic study was conducted on albino Wistar rats to evaluate the bioavailability and neuropharmacokinetic parameters after intranasal administration of the optimized formulation (RT-CH-NLCs-OPT). The optimized formulation showed the particle size (170.48 ± 8.37 nm), PDI (0.19 ± 0.03), zeta potential (+ 26.73 mV), and entrapment efficiency (82.37 ± 2.48 %). In vitro drug release study displayed a sustained drug release pattern from RT-CH-NLCs-OPT (86.73±8.58 % in 24 h) in comparison to RT-Dis (98.61±7.24 % in 16 h). The permeability coefficient (PC) was found to be 11.39 ± 1.08×10^-4 cm.h^-1 and 2.34 folds higher than RT-Dis (4.85±1.53×10^-4 cm.h^-1). The relative bioavailability of RT from RT-CH-NLCs-OPT was 3.2-fold greater as compared to RT-Dis. The absolute bioavailability of RT after intranasal administration of RT-CH-NLCs-OPT was 2.1-fold higher than RT-CH-NLCs-OPT administered intravenously. The brain targeting and targeting potential was displayed by DTE (422.03 %) and DTP (76.03 %) after intranasal administration of RT-CH-NLCs-OPT as compared to RT-Dis (DTE 173.91 % and DTP 59.97 %). Furthermore, confocal laser scanning microscopy results confirmed better brain targeting for RT-CH-NLCs-OPT as compared to RT-Dis. From these findings, it could be concluded that RT-CH-NLCs could serve as a promising strategy for targeting RT through the intranasal route.

The effect of the Incontinence Health Belief Development Program on women's urinary incontinence awareness and health beliefs: a randomized controlled trial

INTRODUCTION AND HYPOTHESIS

This study is aimed at determining the effects of the Incontinence Health Belief Development Program (IHBDP) on the urinary incontinence awareness and health beliefs of women in the pre-menopausal period.

METHODS

This randomized controlled study was conducted in 160 eligible women. The pre-test and post-test data of the study were collected from experimental and control groups using the Socio-Demographic Characteristics Information Form, the Incontinence Awareness Scale, the Health Belief Scale on Urinary Incontinence and Kegel Exercise, and the Broome Pelvic Muscle Self-Efficacy Scale. The IHBDP was implemented with members of the experimental group for 5 weeks.

RESULTS

The women in the experimental group showed a significant difference in mean scores at the end of the program on the UI Awareness Scales, the Health Belief Scale on UI, and the Kegel Exercise compared with pre-training scores (p<0.05). In the experimental group, the factor scores and the total score of the Broome Pelvic Muscle Self-Efficacy Scale also increased. Furthermore, a statistically significant total score increase (p<0.05) was observed at the end of the program (79.8±8.8) compared with before the program (35.2±19.6).

CONCLUSIONS

The training given to the women in the pre-menopausal period based on the Health Belief Model appears highly effective in raising awareness about UI, fostering beliefs about Kegel exercises and increasing pelvic floor muscle self-efficacy.

Validity of food additive maltodextrin as placebo and effects on human gut physiology: systematic review of placebo-controlled clinical trials

PURPOSE

Maltodextrin (MDX) is a polysaccharide food additive commonly used as oral placebo/control to investigate treatments/interventions in humans. The aims of this study were to appraise the MDX effects on human physiology/gut microbiota, and to assess the validity of MDX as a placebo-control.

METHODS

We performed a systematic review of randomized-placebo-controlled clinical trials (RCTs) where MDX was used as an orally consumed placebo. Data were extracted from study results where effects (physiological/microbial) were attributed (or not) to MDX, and from study participant outcomes data, before-and-after MDX consumption, for post-publication 're-analysis' using paired-data statistics.

RESULTS

Of two hundred-sixteen studies on 'MDX/microbiome', seventy RCTs (n = 70) were selected for analysis. Supporting concerns regarding the validity of MDX as a placebo, the majority of RCTs (60%, CI 95% = 0.48-0.76; n = 42/70; Fisher-exact p = 0.001, expected < 5/70) reported MDX-induced physiological (38.1%, n = 16/42; p = 0.005), microbial metabolite (19%, n = 8/42; p = 0.013), or microbiome (50%, n = 21/42; p = 0.0001) effects. MDX-induced alterations on gut microbiome included changes in the Firmicutes and/or Bacteroidetes phyla, and Lactobacillus and/or Bifidobacterium species. Effects on various immunological, inflammatory markers, and gut function/permeability were also documented in 25.6% of the studies (n = 10/42). Notably, there was considerable variability in the direction of effects (decrease/increase), MDX dose, form (powder/pill), duration, and disease/populations studied. Overall, only 20% (n = 14/70; p = 0.026) of studies cross-referenced MDX as a justifiable/innocuous placebo, while 2.9% of studies (n = 2/70) acknowledged their data the opposite.

CONCLUSION

Orally-consumed MDX often (63.9% of RCTs) induces effects on human physiology/gut microbiota. Such effects question the validity of MDX as a placebo-control in human clinical trials.

Ultrasound-promoted preparation of polyvinyl ferrocene-based electrodes for selective formate separation: Experimental design and optimization

The selective separation of ions is a major technological challenge having far-ranging impacts from product separation in electrochemical production of base chemicals from CO₂ to water purification. In recent years, ion-selective electrochemical systems leveraging redox-materials emerged as an attractive platform based on their reversibility and remarkable ion selectivity. In the present study, we present an ultrasound-intensified fabrication process for polyvinyl ferrocene (PVF)-functionalized electrodes in a carbon nanotube (CNT) matrix for selective electro-adsorption of formate ions. To this end, a response surface methodology involving the Box-Behnken design with three effective independent variables, namely, PVF to CNT ratio, sonication duration, and ultrasonic amplitude was applied to reach the maximum formate adsorption efficiency. The fabricated electrodes were characterized using cyclic voltammetry, X-ray diffraction, Raman spectroscopy, and scanning electron microscopy (SEM). SEM images revealed that an optimized ultrasonic amplitude and sonication time provided remarkable improvements in electrode morphology. Through a sedimentation study, we qualitatively demonstrate that the main optimized conditions improved PVF/CNT dispersion stability, consequently providing the highest number of active surface sites for adsorption and the highest adsorption efficiency. The highest percentage of active electrode surface sites and the maximum adsorption efficiency were 97.8 and 90.7% respectively at a PVF/CNT ratio of 3, ultrasonication time of one hour, and 50% ultrasonic amplitude.

Neuroprotective activity of selenium nanoparticles against the effect of amino acid enantiomers in Alzheimer's disease

Alzheimer's disease (AD), the most prevalent neurodegenerative disease, is characterized by extracellular accumulation of amyloid-beta protein (Aβ), which is believed to be the very starting event of AD neurodegeneration. In this work, D-Phe, D-Ala, and D-Glu amino acids, which are the non-occurring enantiomeric form in the human body, and also D-Asp and DL-SeMet, have proved to be amyloidogenic regarding Aβ₄₂ aggregation in TEM studies. These amyloidogenic amino acid enantiomers also widened Aβ₄₂ fibrils up to 437% regarding Aβ₄₂ alone, suggesting that Aβ₄₂ aggregation is enantiomerically dependent. To inhibit enantiomeric-induced amyloid aggregation, selenium nanoparticles stabilized with chitosan (Ch-SeNPs) were successfully synthesized and employed. Thus, Ch-SeNPs reduced and even completely inhibited Aβ₄₂ aggregation produced in the presence of some amino acid enantiomers. In addition, through UV-Vis spectroscopy and fluorescence studies, it was deduced that Ch-SeNPs were able to interact differently with amino acids depending on their enantiomeric form. On the other hand, antioxidant properties of amino acid enantiomers were evaluated by DPPH and TBARS assays, with Tyr enantiomers being the only ones showing antioxidant effect. All spectroscopic data were statistically analysed through experimental design and response surface analysis, showing that the interaction between the Ch-SeNPs and the amino acids studied was enantioselective and allowing, in some cases, to establish the concentration ratios in which this interaction is maximum.

Mathematical Modeling to Guide Experimental Design: T Cell Clustering as a Case Study

Mathematical modeling provides a rigorous way to quantify immunological processes and discriminate between alternative mechanisms driving specific biological phenomena. It is typical that mathematical models of immunological phenomena are developed by modelers to explain specific sets of experimental data after the data have been collected by experimental collaborators. Whether the available data are sufficient to accurately estimate model parameters or to discriminate between alternative models is not typically investigated. While previously collected data may be sufficient to guide development of alternative models and help estimating model parameters, such data often do not allow to discriminate between alternative models. As a case study, we develop a series of power analyses to determine optimal sample sizes that allow for accurate estimation of model parameters and for discrimination between alternative models describing clustering of CD8 T cells around Plasmodium liver stages. In our typical experiments, mice are infected intravenously with Plasmodium sporozoites that invade hepatocytes (liver cells), and then activated CD8 T cells are transferred into the infected mice. The number of T cells found in the vicinity of individual infected hepatocytes at different times after T cell transfer is counted using intravital microscopy. We previously developed a series of mathematical models aimed to explain highly variable number of T cells per parasite; one of such models, the density-dependent recruitment (DDR) model, fitted the data from preliminary experiments better than the alternative models, such as the density-independent exit (DIE) model. Here, we show that the ability to discriminate between these alternative models depends on the number of parasites imaged in the analysis; analysis of about [Formula: see text] parasites at 2, 4, and 8 h after T cell transfer will allow for over 95% probability to select the correct model. The type of data collected also has an impact; following T cell clustering around individual parasites over time (called as longitudinal (LT) data) allows for a more precise and less biased estimates of the parameters of the DDR model than that generated from a more traditional way of imaging individual parasites in different liver areas/mice (cross-sectional (CS) data). However, LT imaging comes at a cost of a need to keep the mice alive under the microscope for hours which may be ethically unacceptable. We finally show that the number of time points at which the measurements are taken also impacts the precision of estimation of DDR model parameters; in particular, measuring T cell clustering at one time point does not allow accurately estimating all parameters of the DDR model. Using our case study, we propose a general framework on how mathematical modeling can be used to guide experimental designs and power analyses of complex biological processes.

Quality by Design in optimizing the extraction of (poly)phenolic compounds from Vaccinium myrtillus berries

Quality by Design was adopted for developing an effective extraction procedure of (poly)phenolic compounds from bilberry (Vaccinium myrtillus L.) fruits, using a pooled sample of berries from different regions of Ukraine. Mechanical solvent extraction, microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE) were investigated by screening matrices. Extraction time (Time, from 5 to 15 min), organic solvent type (OS type, methanol, ethanol and acetone), organic solvent percentage (OS%, from 50% to 90%), sample/extractant ratio (S/E ratio, from 0.025 to 0.1 g mL^-1), and, only for MAE, extraction temperature (T, from 30 to 60°C), were selected as critical method parameters (CMPs). The spectrophotometric assays total soluble polyphenols (TSP), total monomeric anthocyanins (TMA), and radical scavenging activity (evaluated by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), the 2,2'-azino-di-(3-ethylbenzthiazoline sulfonic acid), and the ferric reducing antioxidant power methods) were chosen as critical method attributes (CMAs). The screening procedure allowed for selecting UAE and methanol, while the other CMPs underwent further optimization through Response Surface Methodology. Target values for TSP, TMA and DPPH were selected and the method operable design region (MODR) was defined by means of Monte-Carlo simulations. The optimized conditions, with the corresponding MODR intervals in bracket, were the following: (i) Time, 17 min (15-23 min); OS%, 56% (44-59%); S/E ratio, 0.030 (0.022-0.034) g mL^-1. Under these experimental conditions, CMAs values of the pooled sample were the following (n = 3): TSP=4433±176 mg (+)-catechin eq/100 g dry weight (d.w.); TMA=3575±194 mg cyanidin-3-glucoside eq/100 g d.w.; DPPH=273±5 μg DPPH inhib./mg d.w. The optimized extraction method was tested for matrix effect (ME%) in the UHPLC-MS/MS analysis of 15 anthocyanins and 20 non-anthocyanins individual (poly)phenols commonly found in bilberries, as well as for luteolin, sinapic acid, and pelargonidin-3-glucoside, absent in this fruit and therefore added to the extracts as surrogate standards for evaluating apparent recovery (AR%). |ME%| was in any case ≤ 23% and AR% of the surrogate standards in the range 91-95%, confirming the very good performances of the optimized extraction method.

Reproducibility of the Standard Model of diffusion in white matter on clinical MRI systems

Estimating intra- and extra-axonal microstructure parameters, such as volume fractions and diffusivities, has been one of the major efforts in brain microstructure imaging with MRI. The Standard Model (SM) of diffusion in white matter has unified various modeling approaches based on impermeable narrow cylinders embedded in locally anisotropic extra-axonal space. However, estimating the SM parameters from a set of conventional diffusion MRI (dMRI) measurements is ill-conditioned. Multidimensional dMRI helps resolve the estimation degeneracies, but there remains a need for clinically feasible acquisitions that yield robust parameter maps. Here we find optimal multidimensional protocols by minimizing the mean-squared error of machine learning-based SM parameter estimates for two 3T scanners with corresponding gradient strengths of 40and80mT/m. We assess intra-scanner and inter-scanner repeatability for 15-minute optimal protocols by scanning 20 healthy volunteers twice on both scanners. The coefficients of variation all SM parameters except free water fraction are ≲10% voxelwise and 1-4% for their region-averaged values. As the achieved SM reproducibility outcomes are similar to those of conventional diffusion tensor imaging, our results enable robust in vivo mapping of white matter microstructure in neuroscience research and in the clinic.

Review: Bioavailability of trace elements in farm animals: definition and practical considerations for improved assessment of efficacy and safety

Currently, the authorisation procedure of trace elements as feed additives in the European Union according to Regulation (EC) No. 1831/2003 does not consider the bioavailability of trace element sources. This manuscript provides framework conditions for in vivo experiments that aim to estimate differences in the relative bioavailability between supplements of essential trace elements. Framework conditions encompass necessary technical information on the test substance, the experimental design and diet composition as well as the suitability of status parameters that allow for relative comparisons of regression variables. This manuscript evolves recommendations for researchers to conduct solid and reliable experiments on the matter as well as decision makers to interpret the value of studies submitted with authorisation applications regarding a certain trace element supplement.

In medio stat virtus: The importance of studying mediums in hypnosis research

Most of the experimental investigations on hypnosis used to compare small samples of individuals with low or high responsiveness to hypnosis by systematically excluding medium responders. The present article underlines the limitations of this methodological approach that may have partially weakened the scientific impact of hypnosis research. In fact, the mediums-neglecting bias might be one of the reasons why some investigations suffer from low replicability and generalizability. Themes such as hypnotizability scales, suggestibility, statistical power, and research design are critically reviewed with the aim of proposing a more rigorous approach that boost up impact and reliability of hypnosis research. In particular, the recruitment of medium hypnotizables and the adoption of a within-instead of a between-subjects design currently seem to be some of the best recommendations for strengthening hypnosis research, as well as to renew the dialogue between clinical and experimental hypnosis.

Opportunities, pitfalls and trade-offs in designing protocols for measuring the neural correlates of speech

Decoding speech and speech-related processes directly from the human brain has intensified in studies over recent years as such a decoder has the potential to positively impact people with limited communication capacity due to disease or injury. Additionally, it can present entirely new forms of human-computer interaction and human-machine communication in general and facilitate better neuroscientific understanding of speech processes. Here, we synthesize the literature on neural speech decoding pertaining to how speech decoding experiments have been conducted, coalescing around a necessity for thoughtful experimental design aimed at specific research goals, and robust procedures for evaluating speech decoding paradigms. We examine the use of different modalities for presenting stimuli to participants, methods for construction of paradigms including timings and speech rhythms, and possible linguistic considerations. In addition, novel methods for eliciting naturalistic speech and validating imagined speech task performance in experimental settings are presented based on recent research. We also describe the multitude of terms used to instruct participants on how to produce imagined speech during experiments and propose methods for investigating the effect of these terms on imagined speech decoding. We demonstrate that the range of experimental procedures used in neural speech decoding studies can have unintended consequences which can impact upon the efficacy of the knowledge obtained. The review delineates the strengths and weaknesses of present approaches and poses methodological advances which we anticipate will enhance experimental design, and progress toward the optimal design of movement independent direct speech brain-computer interfaces.

The impact of e-cigarette product place in music videos on susceptibility to use e-cigarettes among young adults: An experimental investigation

INTRODUCTION

Product placement in music videos is a growing promotional strategy. This study examined the impact of e-cigarette product placement and imagery in music videos on susceptibility to use e-cigarettes among young adults.

METHODS

A non-probability sample of young adults (18 to 24) in Southern California were recruited to participate in an experiment over Zoom. Participants were randomized into a treatment or a control group. The treatment group watched seven music videos with e-cigarette product placement and imagery. The control group watched the same seven music videos with all e-cigarette product placement and imagery digitally removed. Participants completed a questionnaire after watching the music videos. The focus of the analysis was on susceptibility to use e-cigarettes in the future among never users (n = 303).

RESULTS

Participants in the treatment group who had never used e-cigarettes were more likely to report intentions to try e-cigarettes in the future (OR = 1.94, 95% CI [1.08, 3.54], compared to participants in the control group. Participants in the treatment group who had never used e-cigarettes were more likely to report peer influence (OR = 1.97, 95% CI [1.19, 3.32], compared to participants in the control group. While these subitems of susceptibility to use e-cigarettes were statistically significant, the relationship between the treatment group and the composite measure of susceptibility was not.

CONCLUSION

Exposure to e-cigarette product placement in music videos may increase young adults' intentions to try e-cigarettes in the future. Federal, state, and local tobacco control regulatory bodies should consider strategies to reduce e-cigarette product placement in music videos.

Solvent screening, optimization and kinetic parameters of the biocatalytic epoxidation reaction of β-pinene mediated by Novozym®435

Monoterpenes, such as beta-pinene, are secondary metabolites widely used in the flavors and fragrance industries and can have their structure altered to enhance their applicability, such as producing epoxides, which are used as intermediaries for pharmaceuticals. Epoxides are commonly synthesized by the use of inorganic acids as catalysts, although the acid medium induces epoxide degradation. To overcome these limitations biocatalysis is shown as an alternative. Related to, this work aimed to perform the synthesis of β-Pinene epoxide using Pseudozyma antarctica lipase B (Novozym®435) as a biocatalyst, while determining the independent variables that influence the reaction using experimental design tools. Different solvent systems were evaluated (cyclohexane, acetonitrile, ethyl acetate, and dichloromethane) until 72 h reaction time, from which ethyl acetate showed higher conversion into the epoxidized product (40% in 24 h). Under the other solvents systems, several oxidized by-products were obtained, such as ketones and aldehydes. Moreover, applying metrics of green chemistry, ethyl acetate was also corroborated as the most promising solvent, with a higher atom economy (66.8%) in comparison to the others (41.3%), and a smaller E-value (1.19). Ethyl acetate was the solvent/acyl donor of choice and had the molar ratio and percentage of biocatalyst increased, which resulted in 80% of the product after 3 h of reaction. To obtain an optimized model, four independent variables (temperature, stirring, molar ratio, percentage of biocatalyst) were evaluated using experimental design tools, Fractional Factorial Design and Central Composite Rotatable Design, with conversions ranging from 23 to 95% after 3 h. All the independent variables were statistically significant (p < 0.05) and had different degrees of impact on the conversion. Kinetic parameters of the reaction were determined using the Lineweaver-Burk model (results under 30.1 mmol for Km and 10.7 mmol.min^-1 for Vmax). In conclusion, the combination of two different tools of experimental design provided the development of an optimized model for beta-Pinene epoxidation, achieving high conversion to the epoxidized product after 3 h.

Status, masculinity, and femininity at the intersection of age and gender

Although men are generally awarded greater status than women, little is known about how gendered ageism may affect the gender gap in status. Using an online survey experiment (N = 2473), this study examines how cultural beliefs about status, masculinity, and femininity are differentially affected by men's and women's age. Findings show that aging has little effect on men's perceived status, but aging drives both upswings and downswings in women's perceived status, giving men status advantages during early and late adulthood. Similarly, whereas aging does not affect men's perceived masculinity, aging drives upswings and downswings in women's perceived femininity, depending on current age. Perceived masculinity is more strongly linked to men's status than perceived femininity is to women's. Findings contribute to research on status and gendered ageism, and shed light on how age and gender combine to influence ubiquitous social judgments that are integral to the reproduction of social inequality.

Ultra-trace levels voltammetric determination of Pb2+ in the presence of Bi3+ at food samples by a Fe3O4@Schiff base Network1 modified glassy carbon electrode

In this research, a highly sensitive electrochemical sensor was developed for the square wave anodic stripping voltammetric determination of Pb²⁺ at ultra-trace levels. A Glassy carbon electrode was modified with an in-situ electroplated bismuth film and the nanocomposite of a recently synthesized melamine based covalent organic framework (schiff base network₁ (SNW₁)) and Fe₃O₄ nanoparticles (Fe₃O₄@SNW₁). The obtained results exhibit clearly that combination of Fe₃O₄@SNW₁ and in-situ electroplated bismuth film enhances the sensitivity of the modified electrode towards Pb²⁺ remarkably. A Plackett-Burman design was implemented for screening experimental factors to specify the significant variables influencing the sensitivity of the electroanalytical method. Afterward, the effective factors were optimized using Box-Behnken design (BBD). Under optimized conditions, the proposed electrode showed a linear response towards Pb²⁺ in the concentration range of 0.003-0.3 μmol L^-1 with the detection limit of 0.95 nmol L^-1. The selectivity of the fabricated electrode towards different ionic species were checked out and no serious interference was observed. At the end, the application of the designed sensor in the determination of Pb²⁺ at 10 different edible specimens were investigated and the obtained recovery values were in the range of (95.56-106.64%) indicating the successful performance of the designed sensor.

Assessment of nano lipid carrier loaded transdermal patch of rizatriptan benzoate

BACKGROUND

Migraine is a neurological disorder and is accompanied by different painful episodes. Hence the maintenance of a steady-state concentration of drug can be beneficial for the patients suffering with migraine. The present investigation focuses on the development of nano lipid carriers (NLCs) loaded transdermal patch of rizatriptan benzoate to sustain the effect of the drug for the enhancement of therapeutic effects.

METHOD

Stearic acid and peanut oil were used to make the NLCs. A central composite design was employed to observe the effect of formulation factors like solid lipid ratio, phase volume ratio, and concentration of surfactants on the formation of nanoparticles. The effects were evaluated for the responses like particle size and entrapment of the drug in the nanocarriers. The optimized formulation was subjected to compatibility, thermal, surface characteristics, and surface morphology studies. The optimized formulation was dispersed in HPMC 15CPS and PVP K30 polymer matrix and the transdermal patch was evaluated for its mechanical properties, drug release study, and skin irritation study.

RESULTS

The experimental design was suitable to produce nanosized stable lipid carriers of the drug with high drug entrapment. The drug and excipients were found to be compatible. The thermal and surface characteristics study proved the high loading of drug in the nanoparticles. The surface morphology study showed the formation of irregular-shaped NLCs. The transdermal patch had good mechanical properties. The ex vivo study of the formulated patch showed a sustained release of the drug over 24h. No skin irritation was reported from the transdermal patch.

CONCLUSION

Therefore, it can be concluded that the nanoparticles loaded transdermal patch of rizatriptan benzoate can be promising in controlling the divergent phases of migraine.