Terahertz (THz = 1012 Hz) radiation has attracted wide attention for its unprecedented sensing ability and its noninvasive and nonionizing properties. Tremendous strides in THz instrumentation have ...prompted impressive breakthroughs in THz biomedical research. Here, we review the current state of THz spectroscopy and imaging in various biomedical applications ranging from biomolecules, including DNA/RNA, amino acids/peptides, proteins, and carbohydrates, to cells and tissues. We also address the potential biological effects of THz radiation during its biological applications and propose future prospects for this cutting-edge technology.
The self‐sustainable dynamic movement of soft actuators represents a continuous motion upon constant stimulus to achieve its great potential in emerging photoresponsive applications from ...self‐propelling machines, artificial robots to advanced biomimetic devices. Conversion of dynamic isomerization of molecular motors and switches into macroscopic self‐oscillation of soft materials is highly attractive but challenging. In this study, an overcrowded alkene motor with trifunctional acrylate groups is designed and synthesized, and its photoisomerization can be achieved in the liquid‐crystalline networks. Furthermore, the photodynamic storage modulus can be mainly modulated by the dynamic stable–unstable isomerization of the molecular motor upon UV exposure. Thus, the light‐driven self‐oscillating behavior from chaotic to regular movement can be performed based on the photodynamic mechanical balance of the micro‐oscillating modulus of the polymer network triggered by the dynamic reconfiguration of the motor. The results pave the way for inspirations in the development of advanced photoactive functional architectures and biomimetic actuators.
Light‐driven self‐oscillating behavior from chaotic to regular motion is demonstrated in liquid‐crystalline networks loaded with molecular motors. Based on the photodynamic mechanical anisotropy mainly modulated by the reversible stable–unstable isomerization of a molecular motor, the oscillating frequency and deflection amplitude are compatible with the concentration of motor, the UV intensity, and the anisotropic modulus of the polymer network.
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Shape-memory polymers (SMPs), as an important class of smart materials, have been attracting interests from both academia and industries. Over the past two decades, the fundamental ...principles of SMPs have been well established, facilitating research to design different types of SMPs at the molecular structure level. Meanwhile, in recent years, increasing attention has been paid to design SMPs with unique shape-memory behavior and manufacture SMP articles with sophisticated shape towards practical applications. Notably, photo-cross-linking strategy has actively established a powerful platform to develop SMPs from basic molecular structure design to advanced design and manufacturing. This review emphasizes the view that there is a close connection between photo-cross-linking strategy and SMPs. Following a brief introduction on the important general aspects of SMPs, progress in research on various photo-cross-linking approaches used for molecular structure design of SMPs is reviewed. To depict the significance of photo-cross-linking strategy for SMPs beyond conventional molecular structure design, achievements at unconventional aspects of advanced design and 4D printing are highlighted.
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•Embedding double bond in the linear PLA-PCL copolyesters aim to crosslinking.•Using UV-assisted FDM printing strategy to fabricate shape memory architecture.•Development of elbow ...protectors for personalized and patient-adaptable treatment.
4D printing, as a booming additive manufacturing technology of smart material, provides a new opportunity for the development of shape memory polymers (SMPs). Meanwhile, the diversity of SMPs structure calls for flexible and well-adapted printing technology. Fused deposition modelling (FDM) is one of the most versatile and cost-effective methods owing to the simplicity of the technique and broad compatibility with a wide variety of materials, but it fails to deal with the fabrication of shape memory networks that possess excellent structural stability as well as shape memory effect (SME). Aiming to personalized or patient-adaptable treatment devices, in this work, we demonstrate a UV-assisted FDM 4D printing strategy to fabricate elbow protector models based on shape memory copolyester networks. First, the linear unsaturated copolyesters were synthesized, amongst, poly(lactic acid) was chosen as hard segment providing the material a good mechanical performance and printability, the poly(ε-caprolactone) with strong crystallizability was employed as switching segment, and a functional coupling agent contained double bonds was used to join the two segments and as the same time. This copolyester can be easily processed into filament, and the in-situ formation of photo-crosslinking network during the UV-assisted FDM printing not only enhances the bonding strength of each layer, but also may guarantee the obtained objects a good shape memory property. Three models with distinctly Chinese characteristics were printed to demonstrate excellent SME. Then, the elbow protectors both in personalized and patient-adaptable treatment strategies were developed, which indicates a great potential in robust applications.
Water oxidation is the key kinetic bottleneck of photoelectrochemical devices for fuel synthesis. Despite advances in the identification of intermediates, elucidating the catalytic mechanism of this ...multi-redox reaction on metal-oxide photoanodes remains a significant experimental and theoretical challenge. Here, we report an experimental analysis of water oxidation kinetics on four widely studied metal oxides, focusing particularly on haematite. We observe that haematite is able to access a reaction mechanism that is third order in surface-hole density, which is assigned to equilibration between three surface holes and M(OH)-O-M(OH) sites. This reaction exhibits low activation energy (E
≈ 60 meV). Density functional theory is used to determine the energetics of charge accumulation and O-O bond formation on a model haematite (110) surface. The proposed mechanism shows parallels with the function of the oxygen evolving complex of photosystem II, and provides new insights into the mechanism of heterogeneous water oxidation on a metal oxide surface.
Current international guidelines recommend aerobic, resistance, and combined exercises for the management of type 2 diabetes mellitus (T2DM). In our study, we conducted a network meta-analysis to ...assess the comparative impact of different exercise training modalities on glycemic control, cardiovascular risk factors, and weight loss in patients with T2DM.
We searched five electronic databases to identify randomized controlled trials (RCTs) that compared the differences between different exercise training modalities for patients with T2DM. The risk of bias in the included RCTs was evaluated according to the Cochrane tool. Network meta-analysis was performed to calculate mean difference the ratio of the mean and absolute risk differences. Data were analyzed using R-3.4.0.
A total of 37 studies with 2208 patients with T2DM were included in our study. Both supervised aerobic and supervised resistance exercises showed a significant reduction in HbA1c compared to no exercise (0.30% lower, 0.30% lower, respectively), however, there was a less reduction when compared to combined exercise (0.17% higher, 0.23% higher). Supervised aerobic also presented more significant improvement than no exercise in fasting plasma glucose (9.38 mg/dl lower), total cholesterol (20.24 mg/dl lower), triacylglycerol (19.34 mg/dl lower), and low-density lipoprotein cholesterol (11.88 mg/dl lower). Supervised resistance showed more benefit than no exercise in improving systolic blood pressure (3.90 mmHg lower) and total cholesterol (22.08 mg/dl lower. In addition, supervised aerobic exercise was more powerful in improving HbA1c and weight loss than unsupervised aerobic (HbA1c: 0.60% lower; weight loss: 5.02 kg lower) and unsupervised resistance (HbA1c: 0.53% lower) exercises.
Compared with either supervised aerobic or supervised resistance exercise alone, combined exercise showed more pronounced improvement in HbA1c levels; however, there was a less marked improvement in some cardiovascular risk factors. In terms of weight loss, there were no significant differences among the combined, supervised aerobic, and supervised resistance exercises.
Our study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO); registration number: CRD42017067518 .
Under the new vista of carbon neutrality, all industries in China face new challenges. As the pillar industry for fossil energy, the coal industry cannot blindly “de-coal”. It is necessary to combine ...the two-way force associated with abandoned mines to turn energy into resources and problems into solutions. Innovation that combines emission reduction and neutralization can overcome the bottlenecks in carbon neutralization in abandoned mines, and help achieve the national carbon peak in 2030 and carbon neutrality in 2060. This involves the entire life cycle of the mine, including the status quo of abandoned coal mines, and the development of downstream industries. The development mode of resource utilization in abandoned mines in accordance with the national situation was summarized, and the suggestion of carbon neutralization in abandoned mines was put forward, which involves three steps: (1) Define the value of abandoned mines, consolidate energy market share, enjoy the policy dividend, and realize carbon neutralization breakthrough; (2) list the development path of carbon neutralization in abandoned mines, utilize photosynthesis to sequester carbon, combine industrial advantages to promote the development of a new energy industry, promote the integration of carbon emission, gathering, sequestration and utilization, realize carbon sequestration and mineralization in terminals and participate in carbon sink market allocation; (3) promote multiple simultaneous measures to solve existing problems, develop abandoned mines, and implement carbon neutralization goals.
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•Recognize the status of coal mines and achieve breakthroughs in carbon neutrality•Promote clean new energy construction and land restoration in the industry•Realize the integration of carbon emission-collection-storage-utilization•Participate in carbon sink market allocation and promote carbon neutrality•Put forward policy recommendations and get through the implementation blockages
Cerambycidae (longhorn beetles) and related families in the superfamily Chrysomeloidea are important components of forest ecosystems and play a key role in nutrient cycling and pollination. Using ...full mitochondrial genomes and dense taxon sampling, the phylogeny of Chrysomeloidea with a focus on Cerambycidae and allied families was explored. We used 151 mitochondrial genomes (75 newly sequenced) covering all families and 29 subfamilies of Chrysomeloidea. Our results reveal that (i) Chrysomelidae (leaf beetles) are sister to all other chrysomeloid families; (ii) Cerambycidae sensu stricto (s. s.) is polyphyletic due to the inclusion of other families that split Cerambycidae into a ‘lamiine’ clade comprising Lepturinae sensu lato (s. l.) + (Lamiinae + Spondylidinae) and a ‘cerambycine’ clade comprising Dorcasominae + (Cerambycinae + Prioninae s. l.); (iii) the subfamilies within the two clades of Cerambycidae s. s. were monophyletic, except for the placement of Necydalinae nested in Lepturinae, and the placement of Parandrinae within Prioninae (now considered as tribes Necydalini and Parandrini, respectively); (iv) smaller families were grouped into two major clades: one composed of Disteniidae+Vesperidae and the other composed of Orsodacnidae + (Megalopodidae + Oxypeltidae); (v) relationships among the four major clades were poorly supported but were resolved as ((cerambycines + (Disteniidae + Vesperidae) + Orsodacnidae + (Megalopodidae + Oxypeltidae)) + lamiines. Divergence time analyses estimated that Chrysomeloidea originated ca. 154.1 Mya during the late Jurassic, and most subfamilies of Cerambycidae originated much earlier than subfamilies of Chrysomelidae. The diversification of families within Chrysomeloidea was largely coincident with the radiation of angiosperms during the Early Cretaceous.
Seventy‐five full mitochondrial genomes were newly generated and combined with existing Genbank data, for a dataset of 151 mitochondrial genomes covering all families and 29 subfamilies of Chrysomeloidea.
The mitogenomes provide a framework for the phylogeny and classification of Chrysomeloidea, which confirm and extend existing notions of deep‐level relationships of Cerambycidae and the smaller families of Chrysomeloidea.
Divergence time analyses estimated that Chrysomeloidea originated ca. 154.1 Mya in the late Jurassic.
Tungsten carbide is one of the most promising electrocatalysts for the hydrogen evolution reaction, although it exhibits sluggish kinetics due to a strong tungsten-hydrogen bond. In addition, ...tungsten carbide's catalytic activity toward the oxygen evolution reaction has yet to be reported. Here, we introduce a superaerophobic nitrogen-doped tungsten carbide nanoarray electrode exhibiting high stability and activity toward hydrogen evolution reaction as well as driving oxygen evolution efficiently in acid. Nitrogen-doping and nanoarray structure accelerate hydrogen gas release from the electrode, realizing a current density of -200 mA cm
at the potential of -190 mV vs. reversible hydrogen electrode, which manifest one of the best non-noble metal catalysts for hydrogen evolution reaction. Under acidic conditions (0.5 M sulfuric acid), water splitting catalyzed by nitrogen-doped tungsten carbide nanoarray starts from about 1.4 V, and outperforms most other water splitting catalysts.
Compared with the irreversible shape-shifting feature of the traditional one-way shape-memory effect (1W-SME), two-way shape-memory materials (2W-SMMs) can exhibit programmable and reversible shape ...switching between two or more distinct shapes and show great potential in many areas such as artificial muscles and robots. The stress-free 2W-SME can be simply realized in semicrystalline polymer networks with a broad melting temperature (T m) range; however, the working mechanism of these two-way shape-memory polymers has not been clearly understood from the view of crystalline behavior such as stress-induced crystallization and self-nucleation. Herein, we develop a series of PCL-based networks (NW-PCLDA-BA) with a broad melting temperature range (ΔT m) via copolymerization of n-butyl acrylate (BA) and PCL-diacrylate (PCLDA) with gradient molecular weights. The stress-free 2W-SME with desirable reversible actuation was realized through the partial melting–recrystallization process of PCL crystalline domains by tuning the applied programming stress and actuating high temperature (T high) in a rational range of ΔT m. The influences of the self-nucleating effect and the changes in the microstructure of the crystalline domain on the stress-free 2W-SME were systematically investigated, and the mechanism of the actuation behavior was discussed. This work provides a facile strategy to achieve the tunable stress-free 2W-SME as well as the fast evaluation of the best 2W-SME performance in a semicrystalline network system.