221 research outputs found

    Bending force of LLDPE monofilaments at high temperatures measured in DMA (Dynamic Mechanical Analyzer)

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    The bending force of monofilaments used as pile layer in artificial turf football fields is a very important property due to the strong relation with the performance of the entire system being the force that mostly influences the deformation of monofilaments. The existing test methods for measuring this force can only be used to perform tests at room temperature. Nowadays, artificial turf surfaces are being installed worldwide, even in regions with very high values of air temperature, leading to the need of evaluating the performance of monofilaments and thus, of testing their bending force at elevated temperatures. The aim of this paper is to use the DMA's advantage of testing at high temperatures, by using a new test method developed for measuring the bending force of monofilaments at room temperature and to evaluate the results obtained. For this purpose, six different LLDPE (Low Linear Density Polyethylene) monofilaments are tested at temperatures 25 degrees C, 50 degrees C and 80 degrees C and the bending force is measured. The DMA is used successfully on performing tests at high temperatures. Considering the results, an analysis of the bending behavior of LLDPE monofilaments depending on the temperature is done. All fibers show the same trends regarding this influence, with decreasing of the bending force while increasing the temperature

    A systematic review of interpersonal processes and their measurement within experience sampling studies of self-injurious thoughts and behaviours

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    Self-injurious thoughts and behaviours (SITBs) are a leading cause of death, and interpersonal processes (IPs) appear to play a role in SITBs. This systematic review synthesises the literature on IPs and SITBs in daily life and addresses four critical questions: (1) Which IPs have been assessed and how, (2) What is the relationship between IPs and SITBs in daily life?, (3) Do daily-life fluctuations in IPs differ between individuals with and without SITBs?, and (4) Do IPs relate differently to self-injurious thoughts than behaviours? Our review followed PRISMA guidelines and eligible literature was screened until 29 August 2023. We identified 52 Experience Sampling studies (34.62% daily-diary studies) of which most focused on IPs from suicide theories (e.g., thwarted belongingness) but largely used inconsistent operationalizations. Results from 35 studies investigating within-person associations were mixed. Based on 24 studies, whether individuals with and without SITBs differ in their interpersonal experiences remains unclear. Four studies have investigated whether IPs relate to the transition from thoughts to behaviours, but temporal models are needed to draw firm conclusions. Studies investigating IPs and SITBs in daily life are largely inconclusive. Psychometrically validated measures are warranted, and future daily-life studies would benefit from drawing on ideation-to-action frameworks

    DSM-5 non-suicidal self-injury disorder in a community sample: comparing NSSI engagement, recency and severity among emerging adults

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    Up to one in five emerging adults engage in non-suicidal self-injury (NSSI). Providing a better understanding of factors that differentiate between who engages in lifetime NSSI and who is more likely to engage in recent and clinically severe NSSI can provide meaningful information for prevention and intervention of NSSI. The present study (n = 669) considered NSSI lifetime engagement (no prior history of NSSI vs. lifetime NSSI), recency [past NSSI (>12 months ago) vs. recent (≤12-month) NSSI], and clinical severity among those with recent NSSI (subthreshold vs. DSM-5 NSSI disorder). The prevalence of NSSI disorder was 8.4% in emerging adults aged 18 to 26 years old. Higher anxiety levels were related to NSSI engagement, but only depressive symptoms and NSSI versatility were consistently associated with more recent NSSI and NSSI disorder. A stepped-care approach may be required in addressing NSSI among emerging adults

    Biotechnological modification and functionalisation of PET surfaces

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    Synthetic fibres form an important part of the textile industry, the production of poly(ethylene terephthalate) (PET) alone surpassing that of cotton. A disadvantage of synthetic fibres is their low hydrophilicity. Polyester fibres are particularly hydrophobic. This affects the processability and functionalisation of the fibres. A novel and promising alternative is the use of enzymes in surface modification of synthetic fibres. Synthetic materials have generally been considered resistant to biological degradation; recent developments at different research groups demonstrate that enzymes are very well capable of hydrolysing synthetic materials

    PAK6 Phosphorylates 14-3-3 gamma to Regulate Steady State Phosphorylation of LRRK2

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    Mutations in Leucine-rich repeat kinase 2 (LRRK2) are associated with Parkinson’s disease (PD) and, as such, LRRK2 is considered a promising therapeutic target for age-related neurodegeneration. Although the cellular functions of LRRK2 in health and disease are incompletely understood, robust evidence indicates that PD-associated mutations alter LRRK2 kinase and GTPase activities with consequent deregulation of the downstream signaling pathways. We have previously demonstrated that one LRRK2 binding partner is P21 (RAC1) Activated Kinase 6 (PAK6). Here, we interrogate the PAK6 interactome and find that PAK6 binds a subset of 14-3-3 proteins in a kinase dependent manner. Furthermore, PAK6 efficiently phosphorylates 14-3-3γ at Ser59 and this phosphorylation serves as a switch to dissociate the chaperone from client proteins including LRRK2, a well-established 14-3-3 binding partner. We found that 14-3-3γ phosphorylated by PAK6 is no longer competent to bind LRRK2 at phospho-Ser935, causing LRRK2 dephosphorylation. To address whether these interactions are relevant in a neuronal context, we demonstrate that a constitutively active form of PAK6 rescues the G2019S LRRK2-associated neurite shortening through phosphorylation of 14-3-3γ. Our results identify PAK6 as the kinase for 14-3-3γ and reveal a novel regulatory mechanism of 14-3-3/LRRK2 complex in the brain

    Biotechnological modification of polyester surfaces

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    Synthetic fibres form an important part of the textile industry, the production of poly(ethylene terephthalate) (PET) alone surpassing that of cotton. A disadvantage of synthetic fibres is their low hydrophilicity. Polyester fibres are particularly hydrophobic. This affects the processability and functionalisation of the fibres. A novel and promising alternative is the use of enzymes in surface modification of synthetic fibres. Synthetic materials have generally been considered resistant to biological degradation; recent developments at different research groups demonstrate that enzymes are very well capable of hydrolysing synthetic materials. Cutinase has been reported to increase hydrophilicity of polyesters by hydrolysis of ester bonds. Hydrolysis of PET by cutinase is via an endo-mechanism, resulting in new carboxyl and hydroxyl groups in the polymer surface. NaOH hydrolysis is via hydrolysis of end groups which results in little or no increase of new carboxyl and hydroxyl groups in the polymer surface. The enzymatic process therefore facilitates functionalisation processes. Enzymes will not penetrate into the material, and therefore not affect the favourable bulk properties contrary to chemical treatments. Manipulation of surface characteristics of textile materials is of fundamental importance in the production of advanced functional textiles. While a lot of research focuses on chemical modification or structuring of the surfaces, the introduction of functionalities using enzymes is a relatively unexplored and modern scientific area. The advantage of biotechnology or more specifically enzymes over other technologies is their high specificity towards a certain reaction or substrate. The general aim of our research is to functionalise (bio)polymeric textile materials using modern biotechnology. Enzymatic surface modification of textile materials involves processing of fibres or (bio)polymers to modify the physical chemical surface properties or the introduction of functional groups on the surface. The research presented focuses on specific enzymatic surface modification of PET to obtain functional structured surfaces. Control of enzymatic action at correct time and length scales is a prerequisite to achieve the desired functionalities. The research will result in new, specific knowledge and technologies to create biotechnologically modified textile materials with unique properties. The research contributes to bio-based economy through the development of novel processes for textiles exhibiting the desired functionalities and through development of novel enzyme technology for structuring and functionalisation of surfaces. Acknowledgements: This work is supported by a grant of the European Commission, FP7, Grant Agreement Number PIEF-GA-2008-219665
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