Lung cancer is a malignant tumor with high rates of mortality and shows significant hereditary predisposition. Previous genome-wide association studies suggest that rs748404, located at promoter of ...TGM5 (transglutaminase 5), is associated with lung carcinoma. By analysis of 1000 genomes project data for three representative populations in the world, another five SNPs are identified to be in strong linkage disequilibrium with rs748404, thus suggesting that they may also be associated with lung carcinoma risk. However, it is ambiguous about the actually causal SNP(s) and the mechanism for the association. Dual-luciferase assay indicates that the functional SNPs are not rs748404, rs12911132 or rs35535629 but another three SNPs (rs66651343, rs12909095 and rs17779494) in lung cell. By chromosome conformation capture, it is disclosed that the enhancer encompassing the two SNPs, rs66651343 and rs12909095, can interact with the promoter of CCNDBP1 (cyclin D1 binding protein 1). RNA-seq data analysis indicates that CCNDBP1 expression is dependent on the genotype of these two SNPs. Chromatin immunoprecipitation assay suggests that the fragments spanning rs66651343 and rs12909095 can bind with the transcription factors, cut like homeobox 1 and SRY-box transcription factor 9, respectively. Our results establish the connection between genetic variations at this locus and lung cancer susceptibility.
Covalent adaptable networks (CANs; also known as dynamic covalent networks or vitrimers) are appealing for developing simple and efficient techniques for recycling thermosetting polymers. In this ...paper, ethylene glycol (EG) is used as a solvent to enable pressure-free surface welding, surface repair, and recycling of a malleable epoxy where the transesterification-type bond exchange reaction (BER) imparts a dynamic nature to the covalent network. At a high temperature, the EG molecules participate in the BER, leading to dissolution of the epoxy network. If the EG is allowed to evaporate, the dissolved epoxy can re-form into a solid. The effects of EG content, temperature, and catalyst concentration on EG-assisted BERs are investigated. It is found that the amount of EG can be adjusted to tune the solution/solid transformation: An excessive amount of EG is required to dissolve the epoxy; on the other hand, a shortage of EG can shift the reaction back to re-form the polymer. Furthermore, the catalyst concentration defines the point at which dissolution initiates, while the degradation rate depends on temperature. This new EG-assisted method is further used for surface welding, surface damage repair, and powder-based reprocessing. The EG-assisted method does not require pressure and can achieve the properties of a fresh sample. It also provides potential opportunities to develop facile recycling techniques for thermosetting polymers.
Thermosetting polymers and composites are a class of high-performance materials with significant industrial applications. However, recycling of thermosets and their filling matters are significantly ...challenging. Here, we propose a method to recycle epoxy thermosetting polymer and composites efficiently by a synergistic effect of a solvent mixture using a highly efficient organic catalyst at an ordinary pressure and mild temperatures. The anhydride-epoxy network depolymerization enabled by selective ester bond cleavage process is substantially enhanced by a good solvent assisted and alcohol participated transesterification reaction. The epoxy thermoset can be dissolved in 28 min with 50% mass loss, and 70 min with 95% mass loss at 170 °C under ambient pressure. We demonstrate that this method can be used to reclaim carbon fibers from industrial reinforced epoxy composite products and embedded metal parts from commercial electronic products with undiminished properties at a mild temperature (∼170 °C) under an ordinary pressure in a short time (1.5 h). Moreover, the decomposed epoxy oligomer can be reused as a reactive ingredient for the preparation of new epoxy materials with high strength and modulus. This work provides a new insight into the thermosets dissolution and recycling.
Edge-computing-enhanced Internet of Vehicles (EC-IoV) enables ubiquitous data processing and content sharing among vehicles and terrestrial edge computing (TEC) infrastructures (e.g., 5G base ...stations and roadside units) with little or no human intervention, and plays a key role in the intelligent transportation systems. However, EC-IoV is heavily dependent on the connections and interactions between vehicles and TEC infrastructures, thus will break down in some remote areas where TEC infrastructures are unavailable (e.g., desert, isolated islands, and disaster-stricken areas). Driven by the ubiquitous connections and global-area coverage, space-air-ground-integrated networks (SAGINs) efficiently support seamless coverage and efficient resource management, and represent the next frontier for edge computing. In light of this, we first review the state-of-the-art edge computing research for SAGINs in this article. After discussing several existing orbital and aerial edge computing architectures, we propose a framework of edge computing-enabled SAGINs to support various Internet of Vehicles (EC-IoV) services for the vehicles in remote areas. The main objective of the framework is to minimize the task completion time and satellite resource usage. To this end, a preclassification scheme is presented to reduce the size of action space, and a deep imitation learning-driven offloading and caching algorithm is proposed to achieve real-time decision making. The simulation results show the effectiveness of our proposed scheme. Finally, we also discuss some technology challenges and future directions.
MXene‐based thermal camouflage materials have gained increasing attention due to their low emissivity, however, the poor anti‐oxidation restricts their potential applications under complex ...environments. Various modification methods and strategies, e.g., the addition of antioxidant molecules and fillers have been developed to overcome this, but the realization of long‐term, reliable thermal camouflage using MXene network (coating) with excellent comprehensive performance remains a great challenge. Here, a MXene‐based hybrid network comodified with hyaluronic acid (HA) and hyperbranched polysiloxane (HSi) molecules is designed and fabricated. Notably, the presence of appreciated HA molecules restricts the oxidation of MXene sheets without altering infrared stealth performance, superior to other water‐soluble polymers; while the HSi molecules can act as efficient cross‐linking agents to generate strong interactions between MXene sheets and HA molecules. The optimized MXene/HA/HSi composites exhibit excellent mechanical flexibility (folded into crane structure), good water/solvent resistance, and long‐term stable thermal camouflage capability (with low infrared emissivity of ≈0.29). The long‐term thermal camouflage reliability (≈8 months) under various outdoor weathers and the scalable coating capability of the MXene‐coated textile enable them to disguise the IR signal of various targets in complex environments, indicating the great promise of achieved material for thermal camouflage, IR stealth, and counter surveillance.
A high‐performance thermal camouflage material is designed and successfully fabricated by decorating MXene network with hyaluronic acid (HA) and hyperbranched polysiloxane (HSi). Besides excellent mid‐infrared (IR) thermal camouflage, such material also integrates multiple advantages into itself, including being large‐scale, mechanically flexible, weather‐resistant, and thus showing great potential for stealth applications.
Development of green campus in China Tan, Hongwei; Chen, Shuqin; Shi, Qian ...
Journal of cleaner production,
02/2014, Letnik:
64
Journal Article
Recenzirano
The higher education is experiencing a rapid development in China, with the sharp increase of energy use and the low level of campus facility operation. Meanwhile, with the responsibility for ...knowledge transformation, sci-tech talents cultivation and technical innovation, universities are of great importance in the development of the sustainable society. The initiative of green campus has attracted great attention from both the society and the universities themselves. Therefore, it is very meaningful to get a full understanding of the current status of green campus development in China, and make the feasibility planning for the next step on this base. In this paper, the progress of green campus development in China is summarized, including all the initiatives to conduct the energy and resource efficient campus, and the current status of upgrading the energy and resource efficient campus to the green campus; the problems occurred during the development are analyzed, and the possible approaches and the action plan are explored accordingly, to promote the green campus development. It is found from the analysis that the development of energy and resource efficient campus has been expanded in a large scale in China, mainly aiming at the energy efficient technology application and campus energy management, and all these initiatives are strongly promoted by the national government with policy support and financial funding. With these great endeavors, an upgrade from the energy and resource efficient campus to the green campus is on progress, which expands its scope to sustainable education and the initiative of low-carbon life on campus. However, many problems also occurred during the progress, such as the lack of a good top-level design among different national ministries and the collaborative innovation among different departments in the university, and the need of a practical propulsion mode and a long-term mechanism to guarantee green campus development. Hence, some suggestions are made in terms of the administrative management, propulsion approach, evaluation standard, and action plan.
•The progress of green campus development in China is introduced.•Promotion from energy and resource efficient campus to green campus is discussed.•Possible approaches are put forward, to promote green campus development in China.
Highlights
Graphene oxide-based hybrid networks were fabricated via introducing multi-amino molecule with triple roles (i.e., cross-linker, fire retardant and reducing agent).
The optimized hybrid ...network with mechanically robust, exceptional intumescent effect and ultra-sensitive fire alarm response (~ 0.6 s) can be used as desirable smart fire alarm sensor materials.
Exceptional fire shielding performances, e.g., ~ 60% reduction in peak heat release rate and limiting oxygen index of ~ 36.5%, are achieved, when coated such hybrid network onto combustible polymer foam.
Smart fire alarm sensor (FAS) materials with mechanically robust, excellent flame retardancy as well as ultra-sensitive temperature-responsive capability are highly attractive platforms for fire safety application. However, most reported FAS materials can hardly provide sensitive, continuous and reliable alarm signal output due to their undesirable temperature-responsive, flame-resistant and mechanical performances. To overcome these hurdles, herein, we utilize the multi-amino molecule, named HCPA, that can serve as triple-roles including cross-linker, fire retardant and reducing agent for decorating graphene oxide (GO) sheets and obtaining the GO/HCPA hybrid networks. Benefiting from the formation of multi-interactions in hybrid network, the optimized GO/HCPA network exhibits significant increment in mechanical strength, e.g., tensile strength and toughness increase of ~ 2.3 and ~ 5.7 times, respectively, compared to the control one. More importantly, based on P and N doping and promoting thermal reduction effect on GO network, the excellent flame retardancy (withstanding ~ 1200 °C flame attack), ultra-fast fire alarm response time (~ 0.6 s) and ultra-long alarming period (> 600 s) are obtained, representing the best comprehensive performance of GO-based FAS counterparts. Furthermore, based on GO/HCPA network, the fireproof coating is constructed and applied in polymer foam and exhibited exceptional fire shielding performance. This work provides a new idea for designing and fabricating desirable FAS materials and fireproof coatings.
Bond strength of steel reinforcement embedded in ultra‐high‐performance fiber‐reinforced concrete (UHPFRC) plays a vital role in the post‐cracking behavior of reinforced UHPFRC members in flexure or ...tension. This paper presents an analytical study on the bond strength of steel reinforcement in UHPFRC. Three different bond‐slip models, namely the modified fib model, Marchand model and the proposed model are compared in the analytical method and explicit equations are also proposed. Comparisons with test data suggest that the proposed model and explicit equations can evaluate the bond‐slip behavior of reinforcement with good accuracy. Marchand model shows similar predictions of bond‐slip behavior to the proposed model at different load levels, whereas the modified fib model is accurate only when the reinforcement nearly yields in tension. The embedment length required for embedded reinforcement to develop its yield and ultimate strengths can also be calculated from the analytical method and explicit equations.
The structure design and switching regulation of pulse groups in multi‐function radars (MFRs) are closely related to the work mode. The sequential extraction and recognition of MFR pulse group ...structure is a fundamental task to analysing and interpreting the work modes and behaviour intentions of an MFR. In this study, the temporal structure of MFR pulse group is expressed hierarchically, which is intensively modelled based on regular grammar. Besides, a corresponding hierarchical automaton is established to sequentially extract and recognise the MFR pulse group structure in pulse train. The hierarchical automaton used for pulse group recognition has a two‐layer structure. The bottom layer of the hierarchical automaton realises the sequential input of pulses and recognition of pulse subgroups, and the sequential input of pulse subgroups and recognition of pulse groups are realised at the top layer. The simulation results demonstrate that the proposed method performs satisfyingly in recognising the pulse group structure and is robust to not only pulse noises but also to the emitter number and pulse group scale.
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