Carnosine and skeletal muscle dysfunction in a rodent multiple sclerosis model

Muscle weakness and fatigue are primary manifestations of multiple sclerosis (MS), a chronic disease of the central nervous system. Interventions that enhance muscle function may improve overall physical well-being of MS patients. Recently, we described that levels of carnosine, an endogenous muscle dipeptide involved in contractile function and fatigue-resistance, are reduced in muscle tissue from MS patients and a monophasic rodent MS model (experimental autoimmune encephalomyelitis, EAE). In the present study, we aimed to (1) confirm this finding in a chronic EAE model, along with the characterization of structural and functional muscle alterations, and (2) investigate the effect of carnosine supplementation to increase/restore muscle carnosine levels and improve muscle function in EAE. We performed muscle immunohistochemistry and ex vivo contractility measurements to examine muscle structure and function at different stages of EAE, and following nutritional intervention (oral carnosine: 3, 15 or 30 g/L in drinking water). Immunohistochemistry revealed progressively worsening muscle fiber atrophy and a switch towards a fast-twitch muscle phenotype during EAE. Using ex vivo muscle contractility experiments, we observed reductions in muscle strength and contraction speed, but no changes in muscle fatigability of EAE mice. However, carnosine levels were unaltered during all stages of EAE, and even though oral carnosine supplementation dose-dependently increased muscle carnosine levels up to + 94% after 56 days EAE, this did not improve muscle function of EAE mice. In conclusion, EAE mice display significant, yet time-dependent, muscular alterations, and carnosine intervention does not improve muscle function in EAE.

The impact of multimorbidity patterns on health-related quality of life in the general population: results of the Belgian Health Interview Survey

BACKGROUND

Chronic diseases and multimorbidity are a major cause of disease burden-for patients, caregivers, and society. Little is known however about potential interaction effects between specific disease combinations. Besides an additive effect, the presence of multiple conditions could also act synergistically or antagonistically regarding the impact on patients' health-related quality of life (HRQoL). The aim was to estimate the impact of coexisting chronic diseases on HRQoL of the adult general Belgian population.

METHODS

The Belgian Health Interview Survey 2018 provided data on self-reported chronic conditions and HRQoL (EQ-5D-5L) for a nationally representative sample. Linear mixed models were used to analyze two-way and three-way interactions of disease combinations on HRQoL.

RESULTS

Multimorbidity had a prevalence of 46.7% (≥ 2 conditions) and 29.7% (≥ 3 conditions). HRQoL decreased considerably with the presence of multiple chronic diseases. 14 out of 41 dyad combinations and 5 out of 13 triad combinations showed significant interactions, with a dominant presence of negative/synergistic effects. Positive/antagonistic effects were found in more subjective chronic diseases such as depression and chronic fatigue. Conditions appearing the most frequently in significant disease pair interactions were dorsopathies, respiratory diseases, and arthropathies.

CONCLUSIONS

Diverse multimorbidity patterns, both dyads and triads, were synergistically or antagonistically associated with lower HRQoL. Tackling the burden of multimorbidity is needed, especially because most disease combinations affect each other synergistically, resulting in a greater reduction in HRQoL. Further knowledge about those multimorbidity patterns with a greater impact on HRQoL is needed to better understand disease burden beyond mortality and morbidity data.

Metabolic engineering provides insight into the regulation of thiamin biosynthesis in plants

Thiamin (or thiamine) is a water-soluble B-vitamin (B1), which is required, in the form of thiamin pyrophosphate, as an essential cofactor in crucial carbon metabolism reactions in all forms of life. To ensure adequate metabolic functioning, humans rely on a sufficient dietary supply of thiamin. Increasing thiamin levels in plants via metabolic engineering is a powerful strategy to alleviate vitamin B1 malnutrition and thus improve global human health. These engineering strategies rely on comprehensive knowledge of plant thiamin metabolism and its regulation. Here, multiple metabolic engineering strategies were examined in the model plant Arabidopsis thaliana. This was achieved by constitutive overexpression of the three biosynthesis genes responsible for B1 synthesis, HMP-P synthase (THIC), HET-P synthase (THI1), and HMP-P kinase/TMP pyrophosphorylase (TH1), either separate or in combination. By monitoring the levels of thiamin, its phosphorylated entities, and its biosynthetic intermediates, we gained insight into the effect of either strategy on thiamin biosynthesis. Moreover, expression analysis of thiamin biosynthesis genes showed the plant's intriguing ability to respond to alterations in the pathway. Overall, we revealed the necessity to balance the pyrimidine and thiazole branches of thiamin biosynthesis and assessed its biosynthetic intermediates. Furthermore, the accumulation of nonphosphorylated intermediates demonstrated the inefficiency of endogenous thiamin salvage mechanisms. These results serve as guidelines in the development of novel thiamin metabolic engineering strategies.

Cov-MS: A Community-Based Template Assay for Mass-Spectrometry-Based Protein Detection in SARS-CoV-2 Patients

Rising population density and global mobility are among the reasons why pathogens such as SARS-CoV-2, the virus that causes COVID-19, spread so rapidly across the globe. The policy response to such pandemics will always have to include accurate monitoring of the spread, as this provides one of the few alternatives to total lockdown. However, COVID-19 diagnosis is currently performed almost exclusively by reverse transcription polymerase chain reaction (RT-PCR). Although this is efficient, automatable, and acceptably cheap, reliance on one type of technology comes with serious caveats, as illustrated by recurring reagent and test shortages. We therefore developed an alternative diagnostic test that detects proteolytically digested SARS-CoV-2 proteins using mass spectrometry (MS). We established the Cov-MS consortium, consisting of 15 academic laboratories and several industrial partners to increase applicability, accessibility, sensitivity, and robustness of this kind of SARS-CoV-2 detection. This, in turn, gave rise to the Cov-MS Digital Incubator that allows other laboratories to join the effort, navigate, and share their optimizations and translate the assay into their clinic. As this test relies on viral proteins instead of RNA, it provides an orthogonal and complementary approach to RT-PCR using other reagents that are relatively inexpensive and widely available, as well as orthogonally skilled personnel and different instruments. Data are available via ProteomeXchange with identifier PXD022550.

Distinct cellular strategies determine sensitivity to mild drought of Arabidopsis natural accessions

The worldwide distribution of Arabidopsis (Arabidopsis thaliana) accessions imposes different types of evolutionary pressures, which contributes to various responses of these accessions to environmental stresses. Responses to drought stress have mostly been studied in the Columbia accession, which is predominantly used in plant research. However, the reactions to drought stress are complex and our understanding of the responses that contribute to maintaining plant growth during mild drought (MD) is very limited. Here, we studied the mechanisms with which natural accessions react to MD at a physiological and molecular level during early leaf development. We documented variations in MD responses among natural accessions and used transcriptome sequencing of a drought-sensitive accession, ICE163, and a drought-insensitive accession, Yeg-1, to gain insights into the mechanisms underlying this discrepancy. This revealed that ICE163 preferentially induces jasmonate- and anthocyanin-related pathways, which are beneficial in biotic stress defense, whereas Yeg-1 has a more pronounced activation of abscisic acid signaling, the classical abiotic stress response. Related physiological traits, including the content of proline, anthocyanins, and reactive oxygen species, stomatal closure, and cellular leaf parameters, were investigated and linked to the transcriptional responses. We can conclude that most of these processes constitute general drought response mechanisms that are regulated similarly in drought-insensitive and -sensitive accessions. However, the capacity to close stomata and maintain cell expansion under MD appeared to be major factors that allow to better sustain leaf growth under MD.

Serum symmetric dimethylarginine shows a relatively consistent long-term concentration in healthy dogs with a significant effect of increased body fat percentage

Symmetric dimethylarginine (SDMA) is a promising renal marker that correlates well with the glomerular filtration rate and could allow earlier detection of impaired renal function. The main objectives of this study were to assess the long-term variability of SDMA in healthy dogs and examine the influence of an increased body fat percentage on the level of SDMA. Sixteen lean Beagles were randomly assigned to the control group or weight-change group in age- and gender-matched pairs. The energy intake of the control group (n = 8) was strictly regulated to maintain an ideal body weight for 83 weeks, while the weight-change group (n = 8) was fed to induce weight gain (week 0–47), to maintain stable excessive body weight (week 47–56) and to lose weight (week 56–83), consecutively. At 8 specified time points, the body condition score, body composition, glomerular filtration rate, serum concentration of SDMA and creatinine were analyzed. In the control group, the within-subject coefficient of variation, between-subject coefficient of variation, reference change value (type I error = 5%) and index of individuality were 0.16, 0.22, 0.43 and 0.73, respectively. The control group and weight-change group did not differ significantly in SDMA concentration. SDMA showed a significant negative association (coefficient = -0.07) with body fat percentage (p<0.01) in the weight-change group and a significant positive association (coefficient = 7.79) with serum creatinine (p<0.01) in the entire study population. In conclusion, SDMA concentration has high long-term stability in healthy adult dogs. For the evaluation of SDMA concentrations, subject-specific reference values are preferred over a population-based reference value seen their higher sensitivity. Moreover, an increased body fat percentage does seem to affect the serum SDMA concentration of otherwise healthy dogs, but its clinical relevance has to be clarified in further research.

Advancing science or advancing careers? Researchers' opinions on success indicators

The way in which we assess researchers has been under the radar in the past few years. Critics argue that current research assessments focus on productivity and that they increase unhealthy pressures on scientists. Yet, the precise ways in which assessments should change is still open for debate. We circulated a survey with Flemish researchers to understand how they work, and how they would rate the relevance of specific indicators used in research assessments. We found that most researchers worked far beyond their expected working schedule. We also found that, although they spent most of their time doing research, respondents wished they could dedicate more time to it and spend less time writing grants and performing other activities such as administrative duties and meetings. When looking at success indicators, we found that indicators related to openness, transparency, quality, and innovation were perceived as highly important in advancing science, but as relatively overlooked in career advancement. Conversely, indicators which denoted of prestige and competition were generally rated as important to career advancement, but irrelevant or even detrimental in advancing science. Open comments from respondents further revealed that, although indicators which indicate openness, transparency, and quality (e.g., publishing open access, publishing negative findings, sharing data, etc.) should ultimately be valued more in research assessments, the resources and support currently in place were insufficient to allow researchers to endorse such practices. In other words, current research assessments are inadequate and ignore practices which are essential in contributing to the advancement of science. Yet, before we change the way in which researchers are being assessed, supporting infrastructures must be put in place to ensure that researchers are able to commit to the activities that may benefit the advancement of science.

Use of Hybrid Data-Dependent and -Independent Acquisition Spectral Libraries Empowers Dual-Proteome Profiling

In the context of bacterial infections, it is imperative that physiological responses can be studied in an integrated manner, meaning a simultaneous analysis of both the host and the pathogen responses. To improve the sensitivity of detection, data-independent acquisition (DIA)-based proteomics was found to outperform data-dependent acquisition (DDA) workflows in identifying and quantifying low-abundant proteins. Here, by making use of representative bacterial pathogen/host proteome samples, we report an optimized hybrid library generation workflow for DIA mass spectrometry relying on the use of data-dependent and in silico-predicted spectral libraries. When compared to searching DDA experiment-specific libraries only, the use of hybrid libraries significantly improved peptide detection to an extent suggesting that infection-relevant host-pathogen conditions could be profiled in sufficient depth without the need of a priori bacterial pathogen enrichment when studying the bacterial proteome. Proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifiers PXD017904 and PXD017945.

Rethinking success, integrity, and culture in research (part 1) - a multi-actor qualitative study on success in science

BACKGROUND

Success shapes the lives and careers of scientists. But success in science is difficult to define, let alone to translate in indicators that can be used for assessment. In the past few years, several groups expressed their dissatisfaction with the indicators currently used for assessing researchers. But given the lack of agreement on what should constitute success in science, most propositions remain unanswered. This paper aims to complement our understanding of success in science and to document areas of tension and conflict in research assessments.

METHODS

We conducted semi-structured interviews and focus groups with policy makers, funders, institution leaders, editors or publishers, research integrity office members, research integrity community members, laboratory technicians, researchers, research students, and former-researchers who changed career to inquire on the topics of success, integrity, and responsibilities in science. We used the Flemish biomedical landscape as a baseline to be able to grasp the views of interacting and complementary actors in a system setting.

RESULTS

Given the breadth of our results, we divided our findings in a two-paper series, with the current paper focusing on what defines and determines success in science. Respondents depicted success as a multi-factorial, context-dependent, and mutable construct. Success appeared to be an interaction between characteristics from the researcher (Who), research outputs (What), processes (How), and luck. Interviewees noted that current research assessments overvalued outputs but largely ignored the processes deemed essential for research quality and integrity. Interviewees suggested that science needs a diversity of indicators that are transparent, robust, and valid, and that also allow a balanced and diverse view of success; that assessment of scientists should not blindly depend on metrics but also value human input; and that quality should be valued over quantity.

CONCLUSIONS

The objective of research assessments may be to encourage good researchers, to benefit society, or simply to advance science. Yet we show that current assessments fall short on each of these objectives. Open and transparent inter-actor dialogue is needed to understand what research assessments aim for and how they can best achieve their objective.

STUDY REGISTRATION

osf.io/33v3m.

Rethinking success, integrity, and culture in research (part 2) - a multi-actor qualitative study on problems of science

BACKGROUND

Research misconduct and questionable research practices have been the subject of increasing attention in the past few years. But despite the rich body of research available, few empirical works also include the perspectives of non-researcher stakeholders.

METHODS

We conducted semi-structured interviews and focus groups with policy makers, funders, institution leaders, editors or publishers, research integrity office members, research integrity community members, laboratory technicians, researchers, research students, and former-researchers who changed career to inquire on the topics of success, integrity, and responsibilities in science. We used the Flemish biomedical landscape as a baseline to be able to grasp the views of interacting and complementary actors in a system setting.

RESULTS

Given the breadth of our results, we divided our findings in a two-paper series with the current paper focusing on the problems that affect the integrity and research culture. We first found that different actors have different perspectives on the problems that affect the integrity and culture of research. Problems were either linked to personalities and attitudes, or to the climates in which researchers operate. Elements that were described as essential for success (in the associate paper) were often thought to accentuate the problems of research climates by disrupting research culture and research integrity. Even though all participants agreed that current research climates need to be addressed, participants generally did not feel responsible nor capable of initiating change. Instead, respondents revealed a circle of blame and mistrust between actor groups.

CONCLUSIONS

Our findings resonate with recent debates, and extrapolate a few action points which might help advance the discussion. First, the research integrity debate must revisit and tackle the way in which researchers are assessed. Second, approaches to promote better science need to address the impact that research climates have on research integrity and research culture rather than to capitalize on individual researchers' compliance. Finally, inter-actor dialogues and shared decision making must be given priority to ensure that the perspectives of the full research system are captured. Understanding the relations and interdependency between these perspectives is key to be able to address the problems of science.

STUDY REGISTRATION

https://osf.io/33v3m.

Failure to modulate reward prediction errors in declarative learning with theta (6 Hz) frequency transcranial alternating current stimulation

Recent evidence suggests that reward prediction errors (RPEs) play an important role in declarative learning, but its neurophysiological mechanism remains unclear. Here, we tested the hypothesis that RPEs modulate declarative learning via theta-frequency oscillations, which have been related to memory encoding in prior work. For that purpose, we examined the interaction between RPE and transcranial Alternating Current Stimulation (tACS) in declarative learning. Using a between-subject (real versus sham stimulation group), single-blind stimulation design, 76 participants learned 60 Dutch-Swahili word pairs, while theta-frequency (6 Hz) tACS was administered over the medial frontal cortex (MFC). Previous studies have implicated MFC in memory encoding. We replicated our previous finding of signed RPEs (SRPEs) boosting declarative learning; with larger and more positive RPEs enhancing memory performance. However, tACS failed to modulate the SRPE effect in declarative learning and did not affect memory performance. Bayesian statistics supported evidence for an absence of effect. Our study confirms a role of RPE in declarative learning, but also calls for standardized procedures in transcranial electrical stimulation.

Auxin, Abscisic Acid and Jasmonate Are the Central Players in Rice Sheath Rot Caused by Sarocladium oryzae and Pseudomonas fuscovaginae

Sheath rot is an emerging rice disease that causes severe yield losses worldwide. The main causal agents are the toxin producers Sarocladium oryzae and Pseudomonas fuscovaginae. The fungus S. oryzae produces helvolic acid and cerulenin and the bacterium P. fuscovaginae produces cyclic lipopeptides. Helvolic acid and the lipopeptide, fuscopeptin, inhibit membrane-bound H⁺-ATPase pumps in the rice plant. To manage rice sheath rot, a better understanding of the host response and virulence strategies of the pathogens is required. This study investigated the interaction of the sheath rot pathogens with their host and the role of their toxins herein. Japonica rice was inoculated with high- and low-helvolic acid-producing S. oryzae isolates or with P. fuscovaginae wild type and fuscopeptin mutant strains. During infection, cerulenin, helvolic acid and the phytohormones abscisic acid, jasmonate, auxin and salicylic acid were quantified in the sheath. In addition, disease severity and grain yield parameters were assessed. Rice plants responded to high-toxin-producing S. oryzae and P. fuscovaginae strains with an increase in abscisic acid, jasmonate and auxin levels. We conclude that, for both pathogens, toxins play a core role during sheath rot infection. S. oryzae and P. fuscovaginae interact with their host in a similar way. This may explain why both sheath rot pathogens cause very similar symptoms despite their different nature.

Role of inorganic nanoparticle degradation in cancer therapy

Nanomaterials are currently widely exploited for their potential in the development of novel cancer therapies, and so far, mainly nanoparticles (NPs) consisting of liposomes and polymers have made their way into the clinic. However, major bottlenecks for the clinical translation of other types of NPs (i.e. inorganic) are the lack of knowledge concerning their long-term distribution in vivo and their potential toxicity. To counter this, various research groups have worked on soluble NPs, such as zinc oxide (ZnO), copper oxide (CuO), and silver (Ag), which tend to dissolve spontaneously into their ionic form, releasing toxic metal ions and leading to reactive oxygen species (ROS) generation when exposed to cellular environments. By fine-tuning the dissolution kinetics of these NPs, it is possible to control the level of ROS production and thus cytotoxicity to selectively destroy tumor tissue. Specifically, cancer cells tend to exhibit a higher basal level of oxidative stress compared to normal cells due to their higher metabolic rates, and therefore, by engineering NPs that generate sufficient ROS that barely exceed toxic thresholds in cancer cells, normal cells will only experience reversible transient damage. This review focuses on the use of these soluble inorganic NPs for selective cancer therapy and on the various in vitro and in vivo studies that have aimed to control the dissolution kinetics of these NPs, either through particle doping or surface modifications.

Health-related quality of life in patients with non-communicable disease: study protocol of a cross-sectional survey

INTRODUCTION

Non-communicable diseases (NCDs) are associated with lower health-related quality of life (HRQoL). However, knowledge about those diseases and predictors with a greater impact on patients' HRQoL as well as knowledge on the complex relationship between HRQoL and comorbidities is lacking. The aim of this study is to assess the impact of NCDs on patients' HRQoL, with a focus on multimorbidity and socioeconomic status.

METHODS AND ANALYSIS

A primary care-based cross-sectional study is conducted in Flanders (Belgium). Study participants (≥18 years) are medically diagnosed with at least one of the following diseases: cardiometabolic disorders, mental disorders and musculoskeletal disorders. A minimum of 50 general practitioners will participate to recruit participants (convenient sample) and a total of 531 patients will be enrolled (voluntary response sample). Each participant will complete a paper-based questionnaire to gather research outcomes. Statistical analyses will be performed using multiple linear regression models with HRQoL as main outcome parameter, adjusted for possible confounders. This study will generate new evidence on the key predictors of HRQoL in patients with NCDs, and particularly provide new insights in multimorbidity to improve the quality of care in primary care, to support patients' self-management and to allocate resources more effectively.

ETHICS AND DISSEMINATION

The study has been approved by the Ethical Committee of Ghent University Hospital, Ghent, Belgium (reference number: B670201939629) prior to the beginning of the recruitment. Study results will be disseminated through peer-reviewed publications and conference presentations.

Cultural pressure and biased responding in free will attitudes

Whether you believe free will exists has profound effects on your behaviour, across different levels of processing, from simple motor action to social cognition. It is therefore important to understand which specific lay theories are held in the general public and why. Past research largely focused on investigating free will beliefs (FWB, 'Do you think free will exists?'), but largely ignored a second key aspect: free will attitudes (FWA, 'Do you like/value will?'). Attitudes are often independently predictive of behaviour, relative to beliefs, yet we currently know very little about FWAs in the general public. One key issue is whether such attitudes are subject to biased, socially desirable responding. The vast majority of the general public strongly believes in the existence of free will, which might create cultural pressure to value free will positively as well. In this registered report, we used a very large (N = 1100), open available dataset measuring implicit and explicit attitudes towards free will and determinism to address this issue. Our results indicate that both explicit and implicit attitudes towards free will are more positive than attitudes towards determinism. We also show that people experience cultural pressure to value free will, and to devalue determinism. Yet, we found no strong evidence that this cultural pressure affected either implicit or explicit attitudes in this dataset.

DLBCL Cells with Acquired Resistance to Venetoclax Are Not Sensitized to BIRD-2 But Can Be Resensitized to Venetoclax through Bcl-XL Inhibition

Anti-apoptotic Bcl-2-family members are frequently dysregulated in both blood and solid cancers, contributing to their survival despite ongoing oncogenic stress. Yet, such cancer cells often are highly dependent on Bcl-2 for their survival, a feature that is exploited by so-called BH3-mimetic drugs. Venetoclax (ABT-199) is a selective BH3-mimetic Bcl-2 antagonist that is currently used in the clinic for treatment of chronic lymphocytic leukemia patients. Unfortunately, venetoclax resistance has already emerged in patients, limiting the therapeutic success. Here, we examined strategies to overcome venetoclax resistance. Therefore, we used two diffuse large B-cell lymphoma (DLBCL) cell lines, Riva WT and venetoclax-resistant Riva (VR). The latter was obtained by prolonged culturing in the presence of venetoclax. We report that Riva VR cells did not become more sensitive to BIRD-2, a peptide targeting the Bcl-2 BH4 domain, and established cross-resistance towards BDA-366, a putative BH4-domain antagonist of Bcl-2. However, we found that Bcl-XL, another Bcl-2-family protein, is upregulated in Riva VR, while Mcl-1 expression levels are not different in comparison with Riva WT, hinting towards an increased dependence of Riva VR cells to Bcl-XL. Indeed, Riva VR cells could be resensitized to venetoclax by A-1155463, a selective BH3 mimetic Bcl-XL inhibitor. This is underpinned by siRNA experiments, demonstrating that lowering Bcl-XL-expression levels also augmented the sensitivity of Riva VR cells to venetoclax. Overall, this work demonstrates that Bcl-XL upregulation contributes to acquired resistance of DLBCL cancer cells towards venetoclax and that antagonizing Bcl-XL can resensitize such cells towards venetoclax.

An Activating Deletion Variant in the Submembrane Region of Natriuretic Peptide Receptor-B Causes Tall Stature

CONTEXT

C-type natriuretic peptide (CNP) is critically involved in endochondral bone growth. Variants in the genes encoding CNP or its cyclic guanosine monophosphate (cGMP)-forming receptor (natriuretic peptide receptor-B [NPR-B], gene NPR2) cause monogenic growth disorders. Here we describe a novel gain-of-function variant of NPR-B associated with tall stature and macrodactyly of the great toes (epiphyseal chondrodysplasia, Miura type).

DESIGN

History and clinical characteristics of 3 family members were collected. NPR2 was selected for sequencing. Skin fibroblasts and transfected HEK-293 cells were used to compare mutant versus wild-type NPR-B activities. Homology modeling was applied to understand the molecular consequences of the variant.

RESULTS

Mother's height was +2.77 standard deviation scores (SDS). The heights of her 2 daughters were +1.96 SDS at 7 years and +1.30 SDS at 4 years of age. Skeletal surveys showed macrodactyly of the great toes and pseudo-epiphyses of the mid- and proximal phalanges. Sequencing identified a novel heterozygous variant c.1444_1449delATGCTG in exon 8 of NPR2, predicted to result in deletion of 2 amino acids Met482-Leu483 within the submembrane region of NPR-B. In proband's skin fibroblasts, basal cGMP levels and CNP-stimulated cGMP production were markedly increased compared with controls. Consistently, assays with transfected HEK-293 cells showed markedly augmented baseline and ligand-dependent activity of mutant NPR-B.

CONCLUSIONS

We report the second activating variant within the intracellular submembrane region of NPR-B resulting in tall stature and macrodactyly. Our functional and modeling studies suggest that this domain plays a critical role in the baseline conformation and ligand-dependent structural rearrangement of NPR-B required for cGMP production.

Mathematical modelling with experimental validation of viscoelastic properties in non-Newtonian fluids

The paper proposes a mathematical framework for the use of fractional-order impedance models to capture fluid mechanics properties in frequency-domain experimental datasets. An overview of non-Newtonian (NN) fluid classification is given as to motivate the use of fractional-order models as natural solutions to capture fluid dynamics. Four classes of fluids are tested: oil, sugar, detergent and liquid soap. Three nonlinear identification methods are used to fit the model: nonlinear least squares, genetic algorithms and particle swarm optimization. The model identification results obtained from experimental datasets suggest the proposed model is useful to characterize various degree of viscoelasticity in NN fluids. The advantage of the proposed model is that it is compact, while capturing the fluid properties and can be identified in real-time for further use in prediction or control applications. This article is part of the theme issue 'Advanced materials modelling via fractional calculus: challenges and perspectives'.

4D Micro-Computed X-ray Tomography as a Tool to Determine Critical Process and Product Information of Spin Freeze-Dried Unit Doses

Maintaining chemical and physical stability of the product during freeze-drying is important but challenging. In addition, freeze-drying is typically associated with long process times. Therefore, mechanistic models have been developed to maximize drying efficiency without altering the chemical or physical stability of the product. Dried product mass transfer resistance ( R p ) is a critical input for these mechanistic models. Currently available techniques to determine R p only provide an estimation of the mean R p and do not allow measuring and determining essential local (i.e., intra-vial) R p differences. In this study, we present an analytical method, based on four-dimensional micro-computed tomography (4D- μ CT), which enables the possibility to determine intra-vial R p differences. Subsequently, these obtained R p values are used in a mechanistic model to predict the drying time distribution of a spin-frozen vial. Finally, this predicted primary drying time distribution is experimentally verified via thermal imaging during drying. It was further found during this study that 4D- μ CT uniquely allows measuring and determining other essential freeze-drying process parameters such as the moving direction(s) of the sublimation front and frozen product layer thickness, which allows gaining accurate process knowledge. To conclude, the study reveals that the variation in the end of primary drying time of a single vial could be predicted accurately using 4D- μ CT as similar results were found during the verification using thermal imaging.

Weight-gain induced changes in renal perfusion assessed by contrast-enhanced ultrasound precede increases in urinary protein excretion suggestive of glomerular and tubular injury and normalize after weight-loss in dogs

Early detection of obesity-related glomerulopathy in humans is challenging as it might not be detected by routine biomarkers of kidney function. This study's aim was to use novel kidney biomarkers and contrast-enhanced ultrasound (CEUS) to evaluate the effect of obesity development and weight-loss on kidney function, perfusion, and injury in dogs. Sixteen healthy lean adult beagles were assigned randomly but age-matched to a control group (CG) (n = 8) fed to maintain a lean body weight (BW) for 83 weeks; or to a weight-change group (WCG) (n = 8) fed the same diet to induce obesity (week 0-47), to maintain stable obese weight (week 47-56) and to lose BW (week 56-83). At 8 time points, values of systolic blood pressure (sBP); serum creatinine (sCr); blood urea nitrogen (BUN); serum cystatin C (sCysC); urine protein-to-creatinine ratio (UPC); and urinary biomarkers of glomerular and tubular injury were measured. Glomerular filtration rate (GFR) and renal perfusion using CEUS were assayed (except for week 68). For CEUS, intensity- and time-related parameters representing blood volume and velocity were derived from imaging data, respectively. At 12-22% weight-gain, cortical time-to-peak, representing blood velocity, was shorter in the WCG vs. the CG. After 37% weight-gain, sCysC, UPC, glomerular and tubular biomarkers of injury, urinary immunoglobulin G and urinary neutrophil gelatinase-associated lipocalin, respectively, were higher in the WCG. sBP, sCr, BUN and GFR were not significantly different. After 23% weight-loss, all alterations were attenuated. Early weight-gain in dogs induced renal perfusion changes measured with CEUS, without hyperfiltration, preceding increased urinary protein excretion with potential glomerular and tubular injury. The combined use of routine biomarkers of kidney function, CEUS and site-specific urinary biomarkers might be valuable in assessing kidney health of individuals at risk for obesity-related glomerulopathy in a non-invasive manner.

Vitrimers: directing chemical reactivity to control material properties

The development of more sustainable materials with a prolonged useful lifetime is a key requirement for a transition towards a more circular economy. However, polymer materials that are long-lasting and highly durable also tend to have a limited application potential for re-use. This is because such materials derive their durable properties from a high degree of chemical connectivity, resulting in rigid meshes or networks of polymer chains with a high intrinsic resistance to deformation. Once such polymers are fully synthesised, thermal (re)processing becomes hard (or impossible) to achieve without damaging the degree of chemical connectivity, and most recycling options quickly lead to a drop or even loss of material properties. In this context, both academic and industrial researchers have taken a keen interest in materials design that combines high degrees of chemical connectivity with an improved thermal (re)processability, mediated through a dynamic exchange reaction of covalent bonds. In particular vitrimer materials offer a promising concept because they completely maintain their degree of chemical connectivity at all times, yet can show a clear thermally driven plasticity and liquid behavior, enabled through rapid bond rearrangement reactions within the network. In the past decade, many suitable dynamic covalent chemistries were developed to create vitrimer materials, and are now applicable to a wide range of polymer matrices. The material properties of vitrimers, however, do not solely rely on the chemical structure of the polymer matrix, but also on the chemical reactivity of the dynamic bonds. Thus, chemical reactivity considerations become an integral part of material design, which has to take into account for example catalytic and cross-reactivity effects. This mini-review will aim to provide an overview of recent efforts aimed at understanding and controlling dynamic cross-linking reactions within vitrimers, and how directing this chemical reactivity can be used as a handle to steer material properties. Hence, it is shown how a focus on a fundamental chemical understanding can pave the way towards new sustainable materials and applications.

Metal-free activation of molecular oxygen by covalent triazine frameworks for selective aerobic oxidation

Oxygen activation is a critical step in ubiquitous heterogeneous oxidative processes, most prominently in catalysis, electrolysis, and pharmaceutical applications. We present here our findings on metal-free O₂ activation on covalent triazine frameworks (CTFs) as an important class of N-rich materials. The O₂ activation process was studied for the formation of aldehydes, ketones and imines. A detailed mechanistic study of O₂ activation and the role of nitrogen heteroatoms were comprehensively investigated. The electron paramagnetic resonance (EPR) and control experiments provide strong evidence for the reaction mechanism proving the applicability of the CTFs to activate oxygen into superoxide species. This report highlights the importance of a self-templating procedure to introduce N functionalities for the development of metal-free catalytic materials. The presented findings reveal an important step toward the use of CTFs as inexpensive and high-performance alternatives to metal-based materials not only for catalysis but also for biorelated applications dealing with O₂ activation.

Polymer- and Hybrid-Based Biomaterials for Interstitial, Connective, Vascular, Nerve, Visceral and Musculoskeletal Tissue Engineering

In this review, materials based on polymers and hybrids possessing both organic and inorganic contents for repairing or facilitating cell growth in tissue engineering are discussed. Pure polymer based biomaterials are predominantly used to target soft tissues. Stipulated by possibilities of tuning the composition and concentration of their inorganic content, hybrid materials allow to mimic properties of various types of harder tissues. That leads to the concept of "one-matches-all" referring to materials possessing the same polymeric base, but different inorganic content to enable tissue growth and repair, proliferation of cells, and the formation of the ECM (extra cellular matrix). Furthermore, adding drug delivery carriers to coatings and scaffolds designed with such materials brings additional functionality by encapsulating active molecules, antibacterial agents, and growth factors. We discuss here materials and methods of their assembly from a general perspective together with their applications in various tissue engineering sub-areas: interstitial, connective, vascular, nervous, visceral and musculoskeletal tissues. The overall aims of this review are two-fold: (a) to describe the needs and opportunities in the field of bio-medicine, which should be useful for material scientists, and (b) to present capabilities and resources available in the area of materials, which should be of interest for biologists and medical doctors.

Pain Detection with Bioimpedance Methodology from 3-Dimensional Exploration of Nociception in a Postoperative Observational Trial

Although the measurement of dielectric properties of the skin is a long-known tool for assessing the changes caused by nociception, the frequency modulated response has not been considered yet. However, for a rigorous characterization of the biological tissue during noxious stimulation, the bioimpedance needs to be analyzed over time as well as over frequency. The 3-dimensional analysis of nociception, including bioimpedance, time, and frequency changes, is provided by ANSPEC-PRO device. The objective of this observational trial is the validation of the new pain monitor, named as ANSPEC-PRO. After ethics committee approval and informed consent, 26 patients were monitored during the postoperative recovery period: 13 patients with the in-house developed prototype ANSPEC-PRO and 13 with the commercial device MEDSTORM. At every 7 min, the pain intensity was measured using the index of Anspec-pro or Medstorm and the 0-10 numeric rating scale (NRS), pre-surgery for 14 min and post-anesthesia for 140 min. Non-significant differences were reported for specificity-sensitivity analysis between ANSPEC-PRO (AUC = 0.49) and MEDSTORM (AUC = 0.52) measured indexes. A statistically significant positive linear relationship was observed between Anspec-pro index and NRS (r2 = 0.15, p < 0.01). Hence, we have obtained a validation of the prototype Anspec-pro which performs equally well as the commercial device under similar conditions.

Emotion regulation training in the treatment of obesity in young adolescents: protocol for a randomized controlled trial

BACKGROUND

The prevalence rates of childhood obesity are increasing. The current multidisciplinary treatments for (childhood) obesity are effective but only moderately and in the short term. A possible explanation for the onset and maintenance of childhood obesity is that it reflects a maladaptive mechanism for regulating high levels of stress and emotions. Therefore, the current RCT study aims to test the effectiveness of adding an emotion regulation training to care as usual (multidisciplinary obesity treatment) in young inpatients (10-14) involved in an obesity treatment program compared to care as usual alone. The research model for this RCT study states that when high levels of stress are regulated in a maladaptive way, this can contribute to the development of obesity.

METHODS

The current study will recruit 140 youngsters (10-14 years) who are involved in an inpatient multidisciplinary obesity treatment (MOT) program. After giving consent to participate in the study, youngsters will be randomly assigned, during consecutive waves, to one of two conditions: care as usual (receiving MOT) or intervention (receiving MOT in addition to emotion regulation training). The training itself consists of 12 weekly sessions, followed by a booster session after 3 and 5 months. The participants will be tested pretraining, post-training, and at 6 months' follow-up. We hypothesize that, compared to the control condition, youngsters in the intervention condition will (1) use more adaptive emotion regulation strategies and (2) report less emotional eating, both primary outcome measures. Moreover, on the level of secondary outcome measures, we hypothesize that youngsters in the intervention condition, compared with the control condition, will (3) report better sleep quality, (4) undergo improved weight loss and weight loss maintenance, and (5) experience better long-term (6-months) psychological well-being.

DISCUSSION

This study will add to both the scientific and clinical literature on the role of emotion regulation in the development and maintenance of different psychopathologies, as emotion regulation is a transdiagnostic factor.

TRIAL REGISTRATION

The RCT study protocol is registered at ISRCTN Registry, with study ID "ISRCTN 83822934." Registered on 13 December 2017.