Developing a class of dual atom materials for multifunctional catalytic reactions

Dual atom catalysts, bridging single atom and metal/alloy nanoparticle catalysts, offer more opportunities to enhance the kinetics and multifunctional performance of oxygen reduction/evolution and hydrogen evolution reactions. However, the rational design of efficient multifunctional dual atom catalysts remains a blind area and is challenging. In this study, we achieved controllable regulation from Co nanoparticles to CoN4 single atoms to Co2N5 dual atoms using an atomization and sintering strategy via an N-stripping and thermal-migrating process. More importantly, this strategy could be extended to the fabrication of 22 distinct dual atom catalysts. In particular, the Co2N5 dual atom with tailored spin states could achieve ideally balanced adsorption/desorption of intermediates, thus realizing superior multifunctional activity. In addition, it endows Zn-air batteries with long-term stability for 800 h, allows water splitting to continuously operate for 1000 h, and can enable solar-powered water splitting systems with uninterrupted large-scale hydrogen production throughout day and night. This universal and scalable strategy provides opportunities for the controlled design of efficient multifunctional dual atom catalysts in energy conversion technologies

Identification and analysis of senescence-related genes in caudal fin cells of triploid crucian carp

This research aims to identify the hub genes associated with the senescence of triploid caudal fin cells. Transcriptomic data are obtained from the high and low generation (P6, P60) of triploid crucian carp caudal fin cells by high-throughput sequencing technology. Initially, all differential genes between the high and low generations are screened, yielding 4140 significantly upregulated genes and 3724 significantly downregulated genes. Subsequently, an aging gene set containing 950 genes is downloaded from the CellAge database to extract the differentially expressed genes associated with caudal fin cell aging, totaling 29 genes. GO and KEGG enrichment analyses are performed on these 29 aging differential genes. The GO analysis shows enrichment mainly in cellular processes related to aging, such as regulation of cell division, chromatin organization, cell cycle regulation. KEGG analysis reveals that the 29 aging-related genes are primarily involved in cell cycle and cellular senescence pathways. A PPI network of aging-related genes is constructed using the STRING database and Cytoscape software. Top-ranked genes were identified by using Degree, MCC, MNC, and Closeness algorithms in the Cytohubba plugin in Cytoscape, resulting in hub genes EZH2, JUN, MYD88, RBL2, BMP4, CCND1, NFKB2, MMP9. Lastly, qRT-PCR validation of these eight hub genes further confirmed the involvement of four genes: EZH2, RBL2, BMP4, and CCND1. The hub gene screened in this study may become a potential biomarker of fish caudal fin cell senescence, which provides a valuable experimental basis for the senescence of fish caudal fin cells, especially the senescence of caudal fin cells in polyploid fish, and the reproduction and breeding improvement of polyploid fish. It also provides meaningful data for elucidating the molecular mechanism of polyploid formation in animals, as well as the formation of aging and tumour in human beings

Optimism bias evaluation and decision-making risk forecast on bridge project cost based on reference class forecasting: Evidence from China

The high uncertainty of megaproject results in increasing complexity in the decisionmaking and ultimately leads to different degrees of cost overrun and project delays. One of the critical reasons for cost overrun and delay is the optimism bias of decision makers. Although the previous literature has analyzed the cost overrun distribution of bridges, roads and other infrastructure projects, there is still a lack of research on how to make more reasonable decisions according to the cost overrun risk and cost-benefit theory by considering the expectation of cost overrun. Therefore, this paper firstly measures optimism bias by conducting the field research and interviews regarding over 30 long bridges in China. On the basis of the optimism bias measure, a decision-making risk model of bridge projects with the expectation of cost overrun has been built. Then the paper takes Hangzhou Bay Bridge as an example to discuss the influence of cost overrun predication, implicit benefits and the project's operation time on NPV results. Moreover, the probability of project unbuildability risk under different degrees of cost optimism bias has also been discussed. Finally, suggestions for risk forecast are provided for decision-makers to make more objective and comprehensive judgments.Integral Design and Managemen

Effect of Sisal Fiber and Polyurethane Admixture on the Strength and Mechanical Behavior of Sand

One major problem related to sandy soil is its low shear strength and cohesion in engineering. Although much effort has been made to strengthen sand mass with satisfactory performances, most undertakings lack environmental considerations. Thus, a combination of natural fiber and macromolecule polymer material attempts to achieve both strength and eco-friendliness. In the present investigation, sisal fiber (SF) and water-based polyurethane (PU) were used to reinforce sand. A series of unconfined compression tests were carried out on sand specimens at different percentages of fiber contents (0.2%, 0.4%, 0.6%, and 0.8% by weight of dry sand) and polymer contents (1%, 2%, 3%, and 4% by weight of dry sand). The results showed within our test range that the unconfined compressive strength (UCS) as well as post-peak strength of specimens increase with fiber and polymer contents. The inclusion of fiber and polymer significantly improve the ductility of specimens. The effect of dry densities on UCS were studied with three proportions. It is found that a high dry density led to an increase of UCS due to an effective contact area increase. The interactions were studied by observation through scanning electron microscopy (SEM) images. The presence of water-based polyurethane has the potential to improve the interparticle cohesion of sand due to its unique network membrane structure. The fiber reinforcement benefit depends strongly on the friction, interlocking force, and bond strength at the interface

Identification of a novel M-superfamily conotoxin with the ability to enhance tetrodotoxin sensitive sodium currents

In this work, a novel M-superfamily conotoxin, designated lt3a, was purified from the crude venom of Conus litteratus. Combined with peptide sequencing, MALDI-TOF mass spectrometry and cDNA cloning techniques, the amino acid sequence of lt3a was supposed to be DgammaCCgamma OQWCDGACDCCS, where O is hydroxyproline and gamma is carboxyglutamate. The Cys framework of lt3a (-CC-C-C-CC-) is similar to that of psi-, mu-, kappaM-conotoxins, which are representatives of M-conotoxins. Peptide lt3a is categorized into M1 branch based on the number of residues in the last Cys loop. Whole cell patch-clamp study on adult rat dorsal root ganglion neurons indicated that lt3a could enhance tetrodotoxin-sensitive sodium currents. This is a previously unknown function of M-superfamily conotoxins

Unconfined Compressive Properties of Composite Sand Stabilized with Organic Polymers and Natural Fibers

As renewable and environment-friendly materials, coir and sisal natural fibers can be used in soil reinforcement with minimum cost and other benefits. In this study, we focused on their improvements of unconfined compressive properties of polymer treated sand. In total, 36 groups of unconfined compressive strength tests, combined with X-ray diffraction and scanning electron microscope investigations were performed. We had studied the effects of polymer and fiber contents, and fiber types on the reinforcement effectiveness. The results showed that both coir and sisal fiber can improve the mechanical properties and microstructure of treated sand. In terms of strength properties, sisal fiber inclusion was better than coir fiber, while both have a similar reinforcement benefit on soil ductile behaviors. The strength and compressive energy increased with an increment in polymer and fiber content. The reinforced sand can have up to 1 MPa compressive strength and 140 kPa compressive energy for coir fiber inclusion, while 1.2 MPa and 170 kPa, respectively, for sisal fiber. The axial stress-strain characteristics and failure patterns were also improved, and the brittle index decreased toward zero, which suggests an increasing ductile. The polymer membrane enwrapping and bonding sand grains, and the network structure built by fiber crossing and overlapping among sand grains, as well as the interfacial attachment conferred by polymer between sand grains and fiber, all contributed to the reinforcement of treated sand

Structural Variations of the 3D Genome Architecture in Cervical Cancer Development

<jats:p>Human papillomavirus (HPV) integration is the major contributor to cervical cancer (CC) development by inducing structural variations (SVs) in the human genome. SVs are directly associated with the three-dimensional (3D) genome structure leading to cancer development. The detection of SVs is not a trivial task, and several genome-wide techniques have greatly helped in the identification of SVs in the cancerous genome. However, in cervical cancer, precise prediction of SVs mainly translocations and their effects on 3D-genome and gene expression still need to be explored. Here, we have used high-throughput chromosome conformation capture (Hi-C) data of cervical cancer to detect the SVs, especially the translocations, and validated it through whole-genome sequencing (WGS) data. We found that the cervical cancer 3D-genome architecture rearranges itself as compared to that in the normal tissue, and 24% of the total genome switches their A/B compartments. Moreover, translocation detection from Hi-C data showed the presence of high-resolution <jats:italic>t</jats:italic>(4;7) (q13.1; q31.32) and <jats:italic>t</jats:italic>(1;16) (q21.2; q22.1) translocations, which disrupted the expression of the genes located at and nearby positions. Enrichment analysis suggested that the disrupted genes were mainly involved in controlling cervical cancer-related pathways. In summary, we detect the novel SVs through Hi-C data and unfold the association among genome-reorganization, translocations, and gene expression regulation. The results help understand the underlying pathogenicity mechanism of SVs in cervical cancer development and identify the targeted therapeutics against cervical cancer.</jats:p&gt

Analysis of expressed sequence tags from the venom ducts of Conus striatus: focusing on the expression profile of conotoxins

Cone snails (genus Conus) are predatory marine gastropods that use venom peptides for interacting with prey, predators and competitors. A majority of these peptides, generally known as conotoxins demonstrate striking selectivity in targeting specific subtypes of ion channels and neurotransmitter receptors. So they are not only useful tools in neuroscience to characterize receptors and receptor subtypes, but offer great potential in new drug research and development as well. Here, a cDNA library from the venom ducts of a fish-hunting cone snail species, Conus striatus is described for the generation of expressed sequence tags (ESTs). A total of 429 ESTs were grouped into 137 clusters or singletons. Among these sequences, 221 were toxin sequences, accounting for 52.1% (corresponding to 19 clusters) of all transcripts. A-superfamily (132 ESTs) and O-superfamily conotoxins (80 ESTs) constitute the predominant toxin components. Some non-disulfide-rich Conus peptides were also found. The expression profile of conotoxins also explained to some extent the pharmacological and physiological reactions elicited by this typical piscivorous species. For the first time, a nonstop transcript of conotoxin was identified, which is suggestive that alternative polyadenylation may be a means of post-transcriptional regulation of conotoxin production. A comparison analysis of these conotoxins reveals the different variation and divergence patterns in these two superfamilies. Our investigations indicate that focal hyper-mutation, block substitution and exon shuffling are three main mechanisms leading to the conotoxin diversity in a species. The comprehensive set of Conus gene sequences allowed the identification of the representative classes of conotoxins and related components, which may lay the foundation for further research and development of conotoxins

Quantum Chemistry Calculation-Aided Structural Optimization of Combretastatin A‑4-like Tubulin Polymerization Inhibitors: Improved Stability and Biological Activity

A potent combretastatin A-4 (CA-4) like tubulin polymerization inhibitor <b>22b</b> was found with strong antitumor activity previously. However, it easily undergoes <i>cis–trans</i> isomerization under natural light, and the resulting decrease in activity limits its further applications. In this study, we used quantum chemistry calculations to explore the molecular basis of its instability. Aided by the calculations, two rounds of structural optimization of <b>22b</b> were conducted. Accelerated quantitative light stability testing confirmed that the stability of these designed compounds was significantly improved as predicted. Among them, compounds <b>1</b> and <b>3b</b> displayed more potent inhibitory activity on tumor cell growth than <b>22b</b>. In addition, the potent <i>in vivo</i> antitumor activity of compound <b>1</b> was confirmed. Quantum chemistry calculations were used in the optimization of stilbene-like molecules, providing new insight into stilbenoid optimization and important implications for the future development of novel CA-4-like tubulin polymerization inhibitors