•Geotagged social media data provide a means to measure visits to urban parks.•Total number and intensity of visits vary significantly among different types of parks.•Park size, entrance fee, and ...distance to city center significantly affected park visits.•Number of bus stops near park was positively related to visits.
Quantifying park use and understanding its driving factors is crucially important for increasing park use and thus human well-being. Previous studies have investigated the effects of different physical and sociocultural factors on park usage using visitor surveys and direct observations of park users, which are usually site specific and time consuming. We quantified and compared the number of visits for different types of parks in Beijing using freely available geotagged check-in data from social media. We investigated how park attributes, park location, park context and public transportation affected the number of park check-in visits, using multiple linear regressions. Despite potential biases in the use of social media data, using a park typology, we found that the number of visits was significantly different among different types of parks. While cultural relics parks and large urban parks had larger numbers of visits, neighborhood parks had higher visitation rates per unit of area. Park size and entrance fees were associated with increased numbers of visits for all types of parks. For parks that mainly serve local residents, the distance to urban center significantly affected park use. The number of bus stops was positively correlated with park visits, suggesting that increased accessibility through public transportation leads to more visits. The results indicated that improving park accessibility via public transportation and planning small, accessible green spaces in residential areas were effective in improving park use.
Hydrogen spillover phenomenon of metal-supported electrocatalysts can significantly impact their activity in hydrogen evolution reaction (HER). However, design of active electrocatalysts faces grand ...challenges due to the insufficient understandings on how to overcome this thermodynamically and kinetically adverse process. Here we theoretically profile that the interfacial charge accumulation induces by the large work function difference between metal and support (∆Φ) and sequentially strong interfacial proton adsorption construct a high energy barrier for hydrogen transfer. Theoretical simulations and control experiments rationalize that small ∆Φ induces interfacial charge dilution and relocation, thereby weakening interfacial proton adsorption and enabling efficient hydrogen spillover for HER. Experimentally, a series of Pt alloys-CoP catalysts with tailorable ∆Φ show a strong ∆Φ-dependent HER activity, in which PtIr/CoP with the smallest ∆Φ = 0.02 eV delivers the best HER performance. These findings have conclusively identified ∆Φ as the criterion in guiding the design of hydrogen spillover-based binary HER electrocatalysts.
Graphene with atomic layer of sp2-hybridized carbon atoms in a hexagonal structure has attracted multidisciplinary attention since its discovery. Due to the inherent advantages of large specific ...surface area and abundant functional groups, its derivative graphene oxide (GO) nanomaterials have achieved large-scale development in effective pollution treatment. In the past few years, novel GO-based nanomaterials through coupling with other nanomaterials have been synthesized with significant process and applied for efficient elimination of different kinds of pollutants. This paper aims to summarize recent research results on the excellent removal ability of GO-based nanomaterials for various heavy metal ions in aqueous solutions. The synthesis, adsorption process characteristics and interaction mechanism of the adsorbent are emphasized and discussed. The effects of various environmental conditions are outlined. At last, a brief summary, perspective and outlook are presented. This review is intended to provide some thrilling information for the design and manufacture of GO-based nanomaterials for the elimination of heavy metal ions from wastewater in environmental pollution management.
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•Synthesis and surface modification of GO-based composites are reviewed.•Applications of different GO-based composites for metal ions elimination are reviewed.•Interaction mechanism of metal ions with GO-based composites is discussed.•Sorption capacities of metal ions on GO-based composites and other materials are compared.•Perspective of GO-based composites in pollution management is summarized.
The synthesis of graphene oxide-based materials and their application in the efficient elimination of different metal ions are summarized and compared with other materials. The interaction mechanism is discussed in detail.
This paper summarizes the current knowledge regarding the possible modes of action and nutritional factors involved in the use of essential oils （EOs） for swine and poultry. EOs have recently ...attracted increased interest as feed additives to be fed to swine and poultry, possibly replacing the use of antibiotic growth promoters which have been prohibited in the European Union since 2006. In general, EOs enhance the production of digestive secretions and nutrient absorption, reduce pathogenic stress in the gut, exert antioxidant properties and reinforce the animal＇s immune status, which help to explain the enhanced performance observed in swine and poultry. However, the mechanisms involved in causing this growth promotion are far from being elucidated, since data on the complex gut ecosystem, gut function, in vivo oxidative status and immune system are still lacking. In addition, limited information is available regarding the interaction between EOs and feed ingredients or other feed additives （especially pro- or prebiotics and organic acids）. This knowledge may help feed formulators to better utilize EOs when they formulate diets for poultry and swine.
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•Strong electronic metal-support interactions (EMSI) between Pt and CeO2 nanorods.•Efficient and selective hydrogenation of quinolines by Pt/CeO2 at room temperature.•Strong EMSI ...enables the enhanced electronic density of Pt anchored on CeO2 nanorods.•Modulated electronic structures of Pt deliver high capability for hydrogen cleavage.•Modulated electronic structures of Pt improve the chemoselectivity.
Selectively catalytic hydrogenation of various quinolines in the presence of other reducible groups into the 1,2,3,4-tetrahydroquinoline compounds under mild conditions is a particular challenge for the heterogeneous catalysts due to the natural chemical stability of quinolines and poor chemoselectivity. Pt-based catalysts generally deliver good catalytic activity and selectivity for hydrogenation of quinolines with other reducible groups. However, the over-hydrogenated by-products are also often observed. Herein, Pt nanoparticles supported on CeO2 nanorods (Pt/NR-CeO2) realized highly efficient and chemoselective hydrogenation of various functionalized quinolines at room temperature. The unusual catalytic performance can be attributed to the strong electronic metal-support interactions (EMSI) between Pt and NR-CeO2 with the abundant surface oxygen vacancy, resulting in the enhanced electronic density of Pt nanoparticles. Subsequently, the modulated electronic structure of Pt enables the efficient hydrogen activation at room temperature, leading to a TOF of 546 h−1 of Pt/NR-CeO2 for the selective hydrogenation of 6-chloroquinolines. Density functional theory calculations also reveal that the high electron density of Pt benefits the desorption of the hydrogenated products and thus avoids the over-hydrogenation effectively.
Abstract
Carbon neutrality initiative has stimulated the development of the sustainable methodologies for hydrogen generation and safe storage. Aqueous-phase reforming methanol and H
2
O (APRM) has ...attracted the particular interests for their high gravimetric density and easy availability. Thus, to efficiently release hydrogen and significantly suppress CO generation at low temperatures without any additives is the sustainable pursuit of APRM. Herein, we demonstrate that the dual-active sites of Pt single-atoms and frustrated Lewis pairs (FLPs) on porous nanorods of CeO
2
enable the efficient additive-free H
2
generation with a low CO (0.027%) through APRM at 120 °C. Mechanism investigations illustrate that the Pt single-atoms and Lewis acidic sites cooperatively promote the activation of methanol. With the help of a spontaneous water dissociation on FLPs, Pt single-atoms exhibit a significantly improved reforming of *CO to promote H
2
production and suppress CO generation. This finding provides a promising path towards the flexible hydrogen utilizations.
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•Photodegradation of POPs by GR-based composites was comprehensively reviewed.•Recent developments in the synthesis of GR-based photocatalysts were summarized.•Catalytic mechanisms ...and roles of GR species in composites were elucidated in depth.•Challenges and future research needs in this field were insightfully suggested.
Over the last decade, two-dimensional graphene (2D GR) has brought new impetus in environmental photocatalysis, mainly benefiting from their unique physicochemical and photoelectric structural properties. Numbers of researchers have spared no effort to utilize visible-light-induced GR-based composites as catalyst platform to generate reactive species in photocatalytic oxidation technology. Herein, a comprehensive overview is presented on recent achievements of the construction and water-related applications of these photocatalysts for persistent organic pollutants (POPs) removal. A brief introduction of synthesis strategies is introduced for GR and its derivatives. Roles of GR as supports, flexible substrates and co-catalysts in composites are specifically pointed out with experimental studies. Most importantly, shortcomings (e.g., fast carrier recombination and serious photocorrosion) appeared in visible light photocatalysis and relative solutions by using GR species are clearly investigated. Based on the current research status, special attention has been paid to their promising applications on removing typical POPs, such as phenols, antibiotics, pharmaceuticals and dyes. Also, challenges (e.g., biotoxicity) and prospects are discussed for future developments in this field. This paper enriches the knowledge to deeply understand the catalytic performances and mechanisms of GR-based photocatalysts, and bring better perspectives for researchers in this field.
Translation initiation is a key step in the regulation of gene expression. In addition to the annotated translation initiation sites (TISs), the translation process may also start at multiple ...alternative TISs (including both AUG and non-AUG codons), which makes it challenging to predict TISs and study the underlying regulatory mechanisms. Meanwhile, the advent of several high-throughput sequencing techniques for profiling initiating ribosomes at single-nucleotide resolution, e.g. GTI-seq and QTI-seq, provides abundant data for systematically studying the general principles of translation initiation and the development of computational method for TIS identification.
We have developed a deep learning-based framework, named TITER, for accurately predicting TISs on a genome-wide scale based on QTI-seq data. TITER extracts the sequence features of translation initiation from the surrounding sequence contexts of TISs using a hybrid neural network and further integrates the prior preference of TIS codon composition into a unified prediction framework.
Extensive tests demonstrated that TITER can greatly outperform the state-of-the-art prediction methods in identifying TISs. In addition, TITER was able to identify important sequence signatures for individual types of TIS codons, including a Kozak-sequence-like motif for AUG start codon. Furthermore, the TITER prediction score can be related to the strength of translation initiation in various biological scenarios, including the repressive effect of the upstream open reading frames on gene expression and the mutational effects influencing translation initiation efficiency.
TITER is available as an open-source software and can be downloaded from https://github.com/zhangsaithu/titer .
lzhang20@mail.tsinghua.edu.cn or zengjy321@tsinghua.edu.cn.
Supplementary data are available at Bioinformatics online.
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•Electrospun Polyasparthydrazide (PAHy) nanofibrous hydrogel dressing was prepared.•Silver nanoparticles (AgNPs) were in-situ synthesized in the PAHy nanofiber hydrogel.•PAHy/AgNPs ...dressing exhibited antibacterial and wound healing-promoting capacities.•PAHy/AgNPs dressing showed great potential for the treatment of infected wounds.
The long-term exposure of skin wounds, especially for those chronic wounds, is commonly accompanied with the bacterial infection, which further holds back the wound healing process. Therefore, it’s urgently required to develop the innovative wound dressings with both antibacterial property and healing-promoting function. In this study, a series of novel hydrogel dressings constructed with polyasparthydrazide (PAHy) nanofibers and different concentrations of in-situ synthesized silver nanoparticles (AgNPs) were designed and prepared. It was found that all the PAHy nanofiber hydrogel mats without or with AgNPs exhibited uniform and bead-free nanofibrous structure, and the AgNPs-contained PAHy nanofiber hydrogel mats showed obviously decreased fiber diameters compared with pure PAHy nanofiber hydrogel mat. The mechanical properties of all as-prepared PAHy/AgNPs nanofiber hydrogel mats in the dry condition were significantly larger than those in the wet condition, and appropriate addition of AgNPs could improve the mechanical properties to some extent. The water swelling ratio of different PAHy/AgNPs hydrogel mats were found to be decreased with the increasing of AgNPs content. The nanofiber hydrogel mat prepared with polysuccinimide (PSI) with 0.5 wt% silver nitrate (AgNO3), named as PAHy/AgNPs-0.5 hydrogel mat, displayed a higher cumulative silver release rate (9.4 ± 1.1 %) after 72 h, and it was demonstrated to possess excellent antibacterial rates against E. coli (99.99 %) and S. aureus (99.99 %), and clear inhibition zones with the diameter of 1.0 ± 0.1 mm for E. coli and 5.8 ± 0.3 mm for S. aureus. Importantly, the animal studies showed that the PAHy/AgNPs-0.5 nanofiber hydrogel mat could significantly accelerate the wound healing process by promoting the re-epithelialization and collagen deposition of wound site, which possessed huge potential for serving as advanced dressing materials for the infected wound treatment.
Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) with chronic and recurrent characteristics caused by multiple reasons. Although the pathogenic factors have not been clarified yet, ...recent studies have demonstrated that intestinal microbiota plays a major role in UC, especially in the immune system. This review focuses on the description of several major microbiota communities that affect UC and their interactions with the host. In this review, eight kinds of microbiota that are highly related to IBD, including
clusters IV and XIVa,
species,
, and
are demonstrated on the changes in amount and roles in the onset and progression of IBD. In addition, potential therapeutic targets for UC involved in the regulation of microbiota, including NLRPs, vitamin D receptor as well as secreted proteins, are discussed in this review.
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