Summary
The project ‘Obesogenic Environment and Childhood Obesity’ (OBECHO), carried out under the leadership of the International Institute of Spatial Lifecourse Epidemiology (ISLE), has reviewed ...all sufficiently reported studies of obesogenic environmental determinants published prior to 1 January 2019. Findings of the OBECHO project have formed the unprecedentedly inclusive evidence for policy‐making and the establishment of the future research agenda regarding the obesogenic environment. Furthermore, the outbreak of the coronavirus disease 2019 (COVID‐19) pandemic has made this evidence become an important benchmark record of how youths have interacted with the obesogenic environment in the pre‐COVID‐19 era. The implementation of lockdown measures worldwide for curbing COVID‐19 transmission has been affecting not mere youth's lifestyle behaviours and weight status but, more fundamentally, obesogenic environments and hence youth‐environment interaction patterns. However, COVID‐19, although causing unfavoured changes, will speed up the transformation of the research landscape from traditional to modern modes for more reliable evidence. We should closely track and study those abnormalities caused by COVID‐19 and the accompanying interventions.
Summary
The increasing prevalence of obesity in youth has contributed to the growing global burden of chronic diseases (e.g. diabetes, cardiovascular diseases and cancers), which has been largely ...accounted for by obesogenic behaviours and environments. Previous studies have focused on the influences on obesity of multidimensional environmental indicators, which have mixed effects, for example, built environmental factors, food environmental factors and neighbourhood safety. After a thorough search of all databases, I found a limited body of reviews on the associations of basic environmental factors. A basic environmental factor, from a perspective of geographic information systems, is an indicator constructed by only one‐step spatial function, without ambiguous effects on obesity. In contrast to basic obesogenic environmental factors, an example of mixed environmental factor is neighbourhood safety, which is a complex measure of night light, crime rate, traffic volume, speed limit, smoothness of roads and many other factors of injury. Without a sufficient, up‐to‐date understanding of the roles of basic obesogenic environmental factors in obesity, the uncertainties will propagate and lead to more uncertainties in the association between indicators and obesity.
As hot topics in the chemical conversion of CO2, the photo‐/electrocatalytic reduction of CO2 and use of CO2 as a supporter for energy storage have shown great potential for the utilization of CO2. ...However, many obstacles still exist on the road to realizing highly efficient chemical CO2 conversion, such as inefficient uptake/activation of CO2 and mass transport in catalysts. Covalent organic frameworks (COFs), as a kind of porous material, have been widely explored as catalysts for the chemical conversion of CO2 owing to their unique features. In particular, COF‐based functional materials containing diverse active sites (such as single metal sites, metal nanoparticles, and metal oxides) offer great potential for realizing CO2 conversion and energy storage. This Minireview discusses recent breakthroughs in the basic knowledge, mechanisms, and pathways of chemical CO2 conversion strategies that use COF‐based functional catalysts. In addition, the challenges and prospects of COF‐based functional catalysts for the efficient utilization of CO2 are also introduced.
This Minireview discusses recent developments in the basic knowledge, mechanisms, and CO2 utilization strategies regarding the use of functional materials based on covalent‐organic frameworks (COFs) with diverse active sites as catalysts. Insight is provided into the challenges and prospects of COF‐based catalysts for the design of the next‐generation photo‐/electrocatalysts for the utilization of CO2.
Dinitrogen cleavage and hydrogenation by transition-metal centers to produce ammonia is central in industry and in Nature. After an introductory section on the thermodynamic and kinetic challenges ...linked to N
2
splitting, this
tutorial review
discusses three major classes of transition-metal systems (homogeneous, heterogeneous and biological) capable of achieving dissociation and hydrogenation of dinitrogen. Molecular complexes, solid-state Haber-Bosch catalytic systems, silica-supported tantalum hydrides and nitrogenase will be discussed. Emphasis is focused on the reaction mechanisms operating in the process of dissociation and hydrogenation of dinitrogen, and in particular on the key role played by metal hydride bonds and by dihydrogen in such reactions.
Transition metal-hydride bonds and bifunctional H
2
heterolytic splitting can play a key role in electron and proton transfer elementary steps involved in homogeneous, heterogeneous and enzymatic systems for N
2
hydrogenative cleavage and NH
3
synthesis.
Organic room temperature luminescent materials present a unique phosphorescence emission with a long lifetime. However, many of these materials only emit single blue or green color in spite of ...external stimulation, and their color tunability is limited. Herein, we report a rational design to extend the emission color range from blue to red by controlling the doping of simple pyrene derivatives into a robust polymer matrix. The integration of these pyrene molecules into the polymer films enhances the intersystem crossing pathway, decreases the first triplet level of the system, and ensures the films show a sensitive response to excitation energy, finally yielding excitation‐dependent long‐life luminescent polymeric systems under ambient conditions. These materials were used to construct anti‐counterfeiting patterns with multicolor interconversion, presenting a promising application potential in the field of information security.
Lucky blue‐red clovers: A strategy for achieving excitation‐dependent long‐life luminescent polymer systems under ambient conditions by tuning the aggregation state of phosphors in polyvinyl alcohol films is developed. The developed polymers show promise in multicolor patterning for anti‐counterfeiting applications.
Wide-field small aperture telescopes are widely used for optical transient observations. Detection and classification of astronomical targets in observed images are the most important and basic step. ...In this paper, we propose an astronomical target detection and classification framework based on deep neural networks. Our framework adopts the concept of the Faster R-CNN and uses a modified Resnet-50 as a backbone network and a feature pyramid network to extract features from images of different astronomical targets. To increase the generalization ability of our framework, we use both simulated and real observation images to train the neural network. After training, the neural network could detect and classify astronomical targets automatically. We test the performance of our framework with simulated data and find that our framework has almost the same detection ability as that of the traditional method for bright and isolated sources and our framework has two times better detection ability for dim targets, albeit all celestial objects detected by the traditional method can be classified correctly. We also use our framework to process real observation data and find that our framework can improve 25% detection ability than that of the traditional method when the threshold of our framework is 0.6. Rapid discovery of transient targets is quite important and we further propose to install our framework in embedded devices such as the Nvidia Jetson Xavier to achieve real-time astronomical targets detection and classification abilities.
When solving constrained optimization problems by evolutionary algorithms, the core issue is to balance constraints and objective function. This paper is the first attempt to utilize the correlation ...between constraints and objective function to keep this balance. First of all, the correlation between constraints and objective function is mined and represented by a correlation index. Afterward, a weighted sum updating approach and an archiving and replacement mechanism are proposed to make use of this correlation index to guide the evolution. By the above process, a novel constrained optimization evolutionary algorithm is presented. Experiments on a broad range of benchmark test functions indicate that the proposed method shows better or at least competitive performance against other state-of-the-art methods. Moreover, the proposed method is applied to the gait optimization of humanoid robots.
Immunotherapy, as a powerful strategy for cancer treatment, has achieved tremendous efficacy in clinical trials. Despite these advancements, there is much to do in terms of enhancing therapeutic ...benefits and decreasing the side effects of cancer immunotherapy. Advanced nanobiomaterials, including liposomes, polymers, and silica, play a vital role in the codelivery of drugs and immunomodulators. These nanobiomaterial-based delivery systems could effectively promote antitumor immune responses and simultaneously reduce toxic adverse effects. Furthermore, nanobiomaterials may also combine with each other or with traditional drugs via different mechanisms, thus giving rise to more accurate and efficient tumor treatment. Here, an overview of the latest advancement in these nanobiomaterials used for cancer immunotherapy is given, describing outstanding systems, including lipid-based nanoparticles, polymer-based scaffolds or micelles, inorganic nanosystems, and others.
Pollution by heavy metals limits the area of land available for cultivation of food crops. A potential solution to this problem might lie in the molecular breeding of food crops for phytoremediation ...that accumulate toxic metals in straw while producing safe and nutritious grains. Here, we identify a rice quantitative trait locus we name cadmium (Cd) accumulation in leaf 1 (CAL1), which encodes a defensin-like protein. CAL1 is expressed preferentially in root exodermis and xylem parenchyma cells. We provide evidence that CAL1 acts by chelating Cd in the cytosol and facilitating Cd secretion to extracellular spaces, hence lowering cytosolic Cd concentration while driving long-distance Cd transport via xylem vessels. CAL1 does not appear to affect Cd accumulation in rice grains or the accumulation of other essential metals, thus providing an efficient molecular tool to breed dual-function rice varieties that produce safe grains while remediating paddy soils.
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