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This study evaluated the effects of maleic anhydride (MA) coupling agent on the mechanical and thermal properties and long-term stability of post-consumer recycled (PCR) plastics. The addition of MA coupling agent increased the tensile strength by 32.12%, enhancing the mechanical durability of the recycled plastic. Furthermore, the melt index (MI) increased by 366.23%, significantly improving processability. Thermogravimetric analysis (TGA) results showed a significant improvement in thermal stability, and a lifetime prediction model estimated an extension of the material’s life by 532.66% at 200 °C. These results demonstrate that MA coupling agent effectively suppresses long-term degradation at high temperatures. Therefore, MA coupling agents can simultaneously improve mechanical properties and recyclability and offer a potent solution for creating sustainable plastics within a circular economy.

Parkinson's disease (PD) is an incurable age-related neurodegenerative disorder affecting both the central and peripheral nervous systems. Although common, the etiology of PD remains poorly understood. Genetic studies infer that the disease results from a complex interaction between genetics and environment and there is growing evidence that PD may represent a constellation of diseases with overlapping yet distinct underlying mechanisms. Novel clinical approaches will require a better understanding of the mechanisms at work within an individual as well as methods to identify the specific array of mechanisms that have contributed to the disease. Induced pluripotent stem cell (iPSC) strategies provide an opportunity to directly study the affected neuronal subtypes in a given patient. Here we report the generation of iPSC-derived midbrain dopaminergic neurons from a patient with a triplication in the α-synuclein gene (SNCA). We observed that the iPSCs readily differentiated into functional neurons. Importantly, the PD-affected line exhibited disease-related phenotypes in culture: accumulation of α-synuclein, inherent overexpression of markers of oxidative stress, and sensitivity to peroxide induced oxidative stress. These findings show that the dominantly-acting PD mutation is intrinsically capable of perturbing normal cell function in culture and confirm that these features reflect, at least in part, a cell autonomous disease process that is independent of exposure to the entire complexity of the diseased brain.

Data suggest that clinical applications of human induced pluripotent stem cells (hiPSCs) will be realized. Nonetheless, clinical applications will require hiPSCs that are free of exogenous DNA and that can be manufactured through Good Manufacturing Practice (GMP). Optimally, derivation of hiPSCs should be rapid and efficient in order to minimize manipulations, reduce potential for accumulation of mutations and minimize financial costs. Previous studies reported the use of modified synthetic mRNAs to reprogram fibroblasts to a pluripotent state. Here, we provide an optimized, fully chemically defined and feeder-free protocol for the derivation of hiPSCs using synthetic mRNAs. The protocol results in derivation of fully reprogrammed hiPSC lines from adult dermal fibroblasts in less than two weeks. The hiPSC lines were successfully tested for their identity, purity, stability and safety at a GMP facility and cryopreserved. To our knowledge, as a proof of principle, these are the first integration-free iPSCs lines that were reproducibly generated through synthetic mRNA reprogramming that could be putatively used for clinical purposes.

Purpose Due to the COVID-19 pandemic, many people have experienced career shocks, especially employees in the hotel industry. To address how to retain talent in the industry, this study aims to examine the joint impacts of employee resilience, work social support and proactive personality on hotel employees’ career change intentions. Design/methodology/approach A survey questionnaire was developed to test the proposed framework. Data from 339 current hotel employees in the USA was analyzed using the PROCESS model. Findings Results show a significant three-way interaction, indicating that for less proactive employees, resilience is negatively associated with career change intentions. However, for highly proactive employees, an additional situation cue in the form of strong work social support is required to activate the expression of resilience. Highly proactive and resilient employees who receive strong supervisor or coworker support during the pandemic have lower career change intentions. However, highly proactive employees who receive weak supervisor or coworker support exhibit similar levels of career change intentions, regardless of resilience level. Practical implications Hotel managers should consider helping employees enhance their resilience and overcome career shocks by providing training and resources and establishing a learning culture. More importantly, it is essential to offer strong supervisor and coworker support to promote resilience among proactive employees. Hotel managers should actively promote strong work social support, and offer training and counseling opportunities to promote employee retention during the pandemic. Originality/value To the best of the authors’ knowledge, this study is the first to examine employee resilience in the hospitality field. This study contributes to the employee resilience literature as well as trait activation theory by examining situational cues that can activate employee resilience and by providing empirical evidence to reveal the boundary conditions of how employee resilience impacts career change intentions.

Nature has evolved selective enzymes for the efficient biosynthesis of complex products. This exceptional ability stems from adapted enzymatic pockets, which geometrically constrain reactants and stabilize specific reactive intermediates by placing electron-donating/accepting residues nearby. Here we perform an abiotic electrophilic aromatic substitution reaction, which is directed precisely through space. Ester arms—positioned above the planes of aromatic rings—enable it to distinguish between nearly identical, neighbouring reactive positions. Quantum mechanical calculations show that, in two competing reaction pathways, both [C–H···O]–hydrogen bonding and electrophile preorganization by coordination to a carbonyl group likely play a role in controlling the reaction. These through-space-directed mechanisms are inspired by dimethylallyl tryptophan synthases, which direct biological electrophilic aromatic substitutions by preorganizing dimethylallyl cations and by stabilizing reactive intermediates with [C–H···N]–hydrogen bonding. Our results demonstrate how the third dimension above and underneath aromatic rings can be exploited to precisely control electrophilic aromatic substitutions. Regioselectivity during electrophilic aromatic substitution is typically controlled by substituents on the aryl group. Here the authors report an electrophilic aromatic substitution reaction, wherein remote chiral ester groups direct the electrophile to a precise location on the molecule.

Personal neoantigen vaccines have been envisioned as an effective approach to induce, amplify and diversify antitumor T cell responses. To define the long-term effects of such a vaccine, we evaluated the clinical outcome and circulating immune responses of eight patients with surgically resected stage IIIB/C or IVM1a/b melanoma, at a median of almost 4 years after treatment with NeoVax, a long-peptide vaccine targeting up to 20 personal neoantigens per patient ( NCT01970358 ). All patients were alive and six were without evidence of active disease. We observed long-term persistence of neoantigen-specific T cell responses following vaccination, with ex vivo detection of neoantigen-specific T cells exhibiting a memory phenotype. We also found diversification of neoantigen-specific T cell clones over time, with emergence of multiple T cell receptor clonotypes exhibiting distinct functional avidities. Furthermore, we detected evidence of tumor infiltration by neoantigen-specific T cell clones after vaccination and epitope spreading, suggesting on-target vaccine-induced tumor cell killing. Personal neoantigen peptide vaccines thus induce T cell responses that persist over years and broaden the spectrum of tumor-specific cytotoxicity in patients with melanoma. Personalized neoantigen vaccination in patients with melanoma elicits durable and specific memory T cell clones that have cytotoxic gene signatures and can diversify to include nonvaccine neoantigen specificities.

Allogeneic lung transplant is limited both by the shortage of available donor lungs and by the lack of suitable long-term lung assist devices to bridge patients to lung transplantation. Avian lungs have different structure and mechanics resulting in more efficient gas exchange than mammalian lungs. Decellularized avian lungs, recellularized with human lung cells, could therefore provide a powerful novel gas exchange unit for potential use in pulmonary therapeutics. To initially assess this in both small and large avian lung models, chicken (Gallus gallus domesticus) and emu (Dromaius novaehollandiae) lungs were decellularized using modifications of a detergent-based protocol, previously utilized with mammalian lungs. Light and electron microscopy, vascular and airway resistance, quantitation and gel analyses of residual DNA, and immunohistochemical and mass spectrometric analyses of remaining extracellular matrix (ECM) proteins demonstrated maintenance of lung structure, minimal residual DNA, and retention of major ECM proteins in the decellularized scaffolds. Seeding with human bronchial epithelial cells, human pulmonary vascular endothelial cells, human mesenchymal stromal cells, and human lung fibroblasts demonstrated initial cell attachment on decellularized avian lungs and growth over a 7-day period. These initial studies demonstrate that decellularized avian lungs may be a feasible approach for generating functional lung tissue for clinical therapeutics.

Solvent-based and mechanical recycling technology approaches were compared with respect to each process’s decontamination efficiency. Herein, post-consumer polystyrene (PS) feedstock was recycled by both technologies, yielding recycled PS resins (rPS). The process feedstock was subjected to four recycling cycles in succession to assess the technology perennity. The physico-chemical and mechanical properties of the rPS were then evaluated to discern the advantages and drawbacks of each recycling approach. The molecular weight of the mechanically recycled resin was found to decrease by 30% over the reprocessing cycles. In contrast, the solvent-base recycling technology yielded a similar molecular weight regarding the feedstock. This consistency in the rPS product is critical for consumer applications. Further qualitative and quantitative analyses on residual organic compounds and inorganic and particulate contaminants were investigated. It was found that the solvent-based technology is very efficient for purifying deeply contaminated feedstock in comparison to mechanical recycling, which is limited to well-cleaned and niche feedstocks.

Fault tolerance is critical for distributed stream processing systems, yet achieving error-free fault tolerance often incurs substantial performance overhead. We present AF-Stream, a distributed stream processing system that addresses the trade-off between performance and accuracy in fault tolerance. AF-Stream builds on a notion called approximate fault tolerance, whose idea is to mitigate backup overhead by adaptively issuing backups, while ensuring that the errors upon failures are bounded with theoretical guarantees. Specifically, AF-Stream allows users to specify bounds on both the state divergence and the loss of non-backup streaming items. It issues state and item backups only when the bounds are reached. Our AF-Stream design provides an extensible programming model for incorporating general streaming algorithms as well as exports only few threshold parameters for configuring approximation fault tolerance. Furthermore, we formally prove that AF-Stream preserves high algorithm-specific accuracy of streaming algorithms, and in particular the convergence guarantees of online learning. Experiments show that AF-Stream maintains high performance (compared to no fault tolerance) and high accuracy after multiple failures (compared to no failures) under various streaming algorithms.

Purpose The current study aims to investigate hotel guests’ intention to use virtual reality (VR) and willingness to pay more for hotels that have VR applications (e.g. virtual room tour) when booking a hotel. Design/methodology/approach Through a theoretical lens of stimuli–organism–response (S-O-R), relationships among an individual’s performance expectancy, effort expectancy, social influence, utilitarian motivation, hedonic motivation, perceived value, intention to use VR and willingness to pay more for VR were tested using partial least square-structural equation modeling. Findings Performance expectancy, social influence, utilitarian motivation and hedonic motivation affect the perceived value of VR. An individual’s perceived value of VR affects his/her intention to use VR and willingness to pay more for a hotel that has VR contents (e.g. virtual room tour) available during the hotel booking process. Originality/value Through the S-O-R framework, this study provided insights into hotel guests’ intention to use VR and explored how their intentions lead to their willingness to pay more for a hotel if VR is available during the reservation or hotel selection process. 探索VR应用对酒店收益管理的影响 摘要 研究目的 本论文旨在检验酒店客人使用VR和愿意预定提供VR应用（比如, 参观虚拟房间）的酒店房间。 研究设计/方法/途径 通过基于S-O-R理论基础, 本论文搭建了模型, 描述个人绩效期望、努力期望、社交影响、实用型动机、和享乐型动机、感知价值、VR使用意图、和VR溢价支付意愿等相互关系, 使用PLS-SEM方法检测模型。 研究结果 研究结果表明, 绩效期望、社交影响、实用型动机、和享乐型动机对VR的感知价值都有影响。个人对VR感知价值对其使用VR和愿意预定提供VR应用（比如, 参观虚拟房间）的酒店房间。