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•Wastes from leather production are upcycled as sustainable fillers for polymer composites.•Leather waste is an adjuvant and synergist to phosphorus flame retardants that decrease the ...fire load of poly(ethylene–vinyl acetate).•The main modes of action, which include enhanced residue formation and stabilization, are explored and characterized multi-methodically.•The combination of flame retardant and filler exhibit better fire performance than equal loadings of only flame retardant.•The chemical mechanisms of flame retardancy are elucidated to explain the fire phenomena.
Leather is among the most ancient, widely used materials worldwide. Industrial-scale leather production produces large quantities of organic waste attained during shaving and buffing steps during processing. In this study, leather wastes (LW) are used as fillers in flame retarded polymer composites. LW is investigated as a multifunctional bio-filler that enhances the fire performance of flame retarded poly(ethylene–vinyl acetate) (EVA) containing phosphorus flame retardants (P-FRs) ammonium polyphosphate (APP) or a melamine-encapsulated APP (eAPP). Using LW from tanneries as adjuvants to enhance P-FRs in EVA reduces industrial wastes that otherwise require costly waste management solutions. Materials are characterized multi-methodically via mechanical tests, electron microscopy, rheology, thermogravimetric analysis, evolved gas analysis, and condensed phase FTIR, also reaction-to-small-flames and cone calorimeter tests. EVA containing 10 wt-% LW and 20 wt-% P-FRs achieve 20% reductions in fire loads versus EVA, and up to 10% reduction in effective heats of combustion versus EVA with equal (30 wt-%) P-FR loadings. Enhanced char stabilization of EVA composites with LW and P-FRs lowered peaks of heat release rates up to 53% compared to EVA, and up to 40% compared to equal P-FRs loadings. Synergisms between LW and P-FRs in EVA are quantified. A chemical decomposition mechanism is proposed.
The first observation of the $ {B}_s^0 $→ (χ$_{c1}$(3872) → J/ψπ$^{+}$π$^{−}$)π$^{+}$π$^{−}$ decay is reported using proton-proton collision data, corresponding to integrated luminosities of 1, 2 and ...6 fb$^{−1}$, collected by the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV, respectively. The ratio of branching fractions relative to the $ {B}_s^0 $→ (ψ(2S) → J/ψπ$^{+}$π$^{−}$)π$^{+}$π$^{−}$ decay is measured to be$ \frac{\mathcal{B}\left({B}_s^0\to {\chi}_{c1}(3872){\pi}^{+}{\pi}^{-}\right)\times \mathcal{B}\left({\chi}_{c1}(3872)\to J/\psi {\pi}^{+}{\pi}^{-}\right)}{\mathcal{B}\left({B}_s^0\to \psi (2S){\pi}^{+}{\pi}^{-}\right)\times \mathcal{B}\left(\psi (2S)\to J/\psi {\pi}^{+}{\pi}^{-}\right)}=\left(6.8\pm 1.1\pm 0.2\right)\times {10}^{-2}, $where the first uncertainty is statistical and the second systematic. The mass spectrum of the π$^{+}$π$^{−}$ system recoiling against the χ$_{c1}$(3872) meson exhibits a large contribution from $ {B}_s^0 $→ χ$_{c1}$(3872) (f$_{0}$(980) → π$^{+}$π$^{−}$) decays.graphic not available: see fulltext
ObjectivesThe Drug-Associated Risk Tool (DART) has been developed as a self-administered questionnaire for patients with the aim of stratifying patients according to their risk of drug-related ...problems (DRPs). We aimed to validate the ability of the questionnaire to distinguish between hospitalised patients showing lower and higher numbers of DRPs.DesignCross-sectional study assessing the questionnaire’s concurrent criterion validity.SettingFive geriatric and the associated physical and neurological rehabilitation wards of a Swiss regional secondary care hospital with 617 beds.ParticipantsWe recruited 110 patients from a total of 437 admissions. Exclusion criteria were insufficient knowledge in spoken or written German, medical conditions preventing meaningful conversations and already receiving pharmacy services.InterventionsComprehensive pharmacist-led clinical medication reviews were performed, including patient interviews, to identify potential and manifest DRPs. A cluster analysis was conducted to assess the discriminatory potential of the DART to group patients according to number (low and high) of identified DRPs. A subsequent discriminatory function analysis was performed to reduce the number of items. We determined which DART items may be used to trigger what type of medication review.ResultsRecruited patients had a median age of 79 years and were prescribed a median of 11 drugs. Patients with a median DART score of 10 and a median of 3 DRPs represented one cluster, whereas patients with a median DART score of 15 and a median of 8 DRPs represented another cluster. Discriminatory function analysis reduced the questionnaire to five items with a moderate to strong correlation with the number of DRPs per patient (Spearman’s rank correlation ρ=0.44). Additional items were associated with patients benefiting from interviews.ConclusionsAs a self-administered questionnaire for patients, the DART may be used to stratify hospitalised non-acute older patients in groups of having low and high likelihood of DRPs. The analyses showed that a short form of the DART can be used instead of the full tool to identify older inpatients at risk for DRPs. Additional eight items from the DART may be used to initiate additional clinical pharmacy services. The linkage between certain DART questions and type of medication review enables pharmacist resource allocation.
The ubiquity of polymeric materials in daily life comes with an increased fire risk, and sustained research into efficient flame retardants is key to ensuring the safety of the populace and material ...goods from accidental fires. Phosphorus, a versatile and effective element for use in flame retardants, has the potential to supersede the halogenated variants that are still widely used today: current formulations employ a variety of modes of action and methods of implementation, as additives or as reactants, to solve the task of developing flame‐retarding polymeric materials. Phosphorus‐based flame retardants can act in both the gas and condensed phase during a fire. This Review investigates how current phosphorus chemistry helps in reducing the flammability of polymers, and addresses the future of sustainable, efficient, and safe phosphorus‐based flame‐retardants from renewable sources.
The burning issue: The ubiquitous use of polymeric materials in daily life comes with an increased fire risk. Continued research into efficient flame retardants is key to ensuring safety. This Review investigates how modern phosphorus chemistry helps to reduce the flammability of polymers, and addresses the future of sustainable, efficient, and safe phosphorus‐based flame retardants from renewable sources.
Polymeric delivery systems have been extensively studied to achieve localized and controlled release of protein drugs. However, it is still challenging to control the release of multiple protein ...drugs in distinct stages according to the progress of disease or treatment. This study successfully demonstrates that multiple protein drugs can be released from aptamer-functionalized hydrogels with adjustable release rates at predetermined time points using complementary sequences (CSs) as biomolecular triggers. Because both aptamer–protein interactions and aptamer–CS hybridization are sequence-specific, aptamer-functionalized hydrogels constitute a promising polymeric delivery system for the programmable release of multiple protein drugs to treat complex human diseases.
Nucleic acid aptamers are an emerging class of synthetic ligands and have recently attracted significant attention in numerous fields. One is in biosensor development. In principle, nucleic acid ...aptamers can be discovered to recognize any molecule of interest with high affinity and specificity. In addition, unlike most ligands evolved in nature, synthetic nucleic acid aptamers are usually tolerant of harsh chemical, physical, and biological conditions. These distinguished characteristics make aptamers attractive molecular recognition ligands for biosensing applications. This review first concisely introduces methods for aptamer discovery including upstream selection and downstream truncation, then discusses aptamer-based biosensor development from the viewpoint of signal production. graphic removed
The ability to regulate cell–material interactions is important in various applications such as regenerative medicine and cell separation. This study successfully demonstrates that the binding states ...of cells on a hydrogel surface can be programmed by using hybridized aptamers and triggering complementary sequences (CSs). In the absence of the triggering CSs, the aptamers exhibit a stable, hybridized state in the hydrogel for cell-type-specific catch. In the presence of the triggering CSs, the aptamers are transformed into a new hybridized state that leads to the rapid dissociation of the aptamers from the hydrogel. As a result, the cells are released from the hydrogel. The entire procedure of cell catch and release during the transformation of the aptamers is biocompatible and does not involve any factor destructive to either the cells or the hydrogel. Thus, the programmable hydrogel is regenerable and can be applied to a new round of cell catch and release when needed.
A rigid aromatic phosphorus‐containing hyperbranched flame retardant structure is synthesized from 10‐(2,5‐dihydroxyphenyl)‐10H‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO‐HQ), ...tris(4‐hydroxyphenyl)phosphine oxide (THPPO), and 1,4‐terephthaloyl chloride (TPC). The resulting poly‐(DOPO‐HQ/THPPO‐terephthalate) (PDTT) is implemented as a flame retardant into an epoxy resin (EP) at a 10 wt% loading. The effects on EP are compared with those of the monomer DOPO‐HQ and triphenylphosphine oxide (OPPh3) as low molar mass flame retardants. The glass transition temperature, thermal decomposition, flammability (reaction to small flame), and burning behavior of the thermosets are investigated using differential scanning calorimetry, thermogravimetric analysis, pyrolysis combustion flow calorimetry, UL 94‐burning chamber testing, and cone calorimeter measurements. Although P‐contents are low at only 0.6 wt%, the study aims not at attaining V‐0, but at presenting a proof of principle: Epoxy resinswith PDTT show promising fire performance, exhibiting a 25% reduction in total heat evolved (THE), a 30% reduction in peak heat release rate (PHRR) due to flame inhibition (21% reduction in effective heat of combustion (EHC)), and an increase in Tg at the same time. This study indicates that rigid aromatic hyperbranched polymeric structures offer a promising route toward multifunctional flame retardancy.
This article reports the results of an investigation of a hyperbranched rigid aromatic phosphorus‐containing flame retardant for epoxy resins. A macromolecule with a rigid, complex shape has been synthesized and characterized, affording multifunctional flame retardancy to a bisphenol A‐based high‐performance thermoset. Fire tests and pyrolysis investigations offer insight into modes of action, and molecular modeling bridges theoretical concept with practice.
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