91 research outputs found

    Ferroelectric higher-order topological insulator in two dimensions

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    The interplay between ferroelectricity and band topology can give rise to a wide range of both fundamental and applied research. Here, we map out the emergence of nontrivial corner states in two-dimensional ferroelectrics, and remarkably demonstrate that ferroelectricity and corner states are coupled together by crystallographic symmetry to realize the electric control of higher-order topology. Implemented by density functional theory, we identify a series of experimentally synthesized two-dimensional ferroelectrics, such as In2_2Se3_3, BN bilayers, and SnS, as realistic material candidates for the proposed ferroelectric higher-order topological insulators. Our work not only sheds new light on traditional ferroelectric materials but also opens an avenue to bridge the higher-order topology and ferroelectricity that provides a nonvolatile handle to manipulate the topology in next-generation electronic devices

    The status and potential of regional integrated energy systems in sub-Saharan Africa: an investigation of the feasibility and implications for sustainable energy development

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    Sub-Saharan Africa (SSA) is experiencing rapid economic growth and rising demand for energy, accompanied by significant low energy access and sustainability challenges. Globally, to address similar issues and unlock a region's energy potential, regional integrated energy systems have gained traction, and initiatives such as establishing power pools for regional electricity markets, cross-border power exchanges, and integrating renewable energy resources are being promoted. This paper describes the status of regional integrated energy systems in Sub-Saharan Africa. We analyze the energy growth achieved through effective strategies and policies that support regional integrated energy systems in developed and developing regions (the United Kingdom and China). Our findings show that challenges, including limited access to financing, regulatory barriers, lack of effective energy planning model, inadequate supporting policies, and fragmented institutional frameworks, hinder the region's widespread deployment of regional integrated energy systems. Taking lessons from the case studies, addressing SSA's energy challenges requires concerted efforts from governments, international organizations, and the private sector to create enabling policy environments, mobilize investments, and build technical capacity and supporting infrastructures. Regional integrated energy systems can enhance energy security by diversifying energy sources, fostering economic development, and stimulating cross-border energy trade. In the United Kingdom, the implementation of integrated energy systems has contributed to a 25% reduction in carbon emissions and a 15% increase in energy efficiency over the past decade. Similarly, in China, the integration of renewable energy sources into regional energy systems has led to a 30% increase in renewable energy capacity and a 20% decrease in coal consumption since 2010. China owns 32% of global renewable energy market, alongside an installed capacity of about 1.26 TW in the first quarter of 2023. Our findings from the power pools indicate that three out of the four pools possess significant hydro energy resources. Specifically, within the CAPP region, 7 out of 10 countries heavily rely on hydro energy, while in EAPP, 6 out of 11 countries exhibit a similar dependency. Moreover, within SAPP, 9 out of 12 countries and within WAPP, 5 out of 14 countries rely significantly on hydro energy

    Porous polydimethylsiloxane films with specific surface wettability but distinct regular physical structures fabricated by 3D printing

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    Porous polydimethylsiloxane (PDMS) films with special surface wettability have potential applications in the biomedical, environmental, and structural mechanical fields. However, preparing porous PDMS films with a regular surface pattern using conventional methods, such as chemical foaming or physical pore formation, is challenging. In this study, porous PDMS films with a regular surface pattern are designed and prepared using 3D printing to ensure the formation of controllable and regular physical structures. First, the effect of the surface wettability of glass substrates with different surface energies (commercial hydrophilic glass and hydrophobic glass (F-glass) obtained by treating regular glass with 1H,1H,2H,2H-perfluorooctyl-trichlorosilane) on the structural characteristics of the 3D printed PDMS filaments is investigated systematically. Additionally, the effect of the printing speed and the surface wettability of the glass substrate on the PDMS filament morphology is investigated synchronously. Next, using the F-glass substrate and an optimized printing speed, the effects of the number of printed layers on both the morphologies of the individual PDMS filaments and porous PDMS films, and the surface wettability of the films are studied. This study reveals that regularly patterned porous PDMS films with distinct structural designs but the same controllable surface wettability, such as anisotropic surface wettability and superhydrophobicity, can be easily fabricated through 3D printing. This study provides a new method for fabricating porous PDMS films with a specific surface wettability, which can potentially expand the application of porous PDMS films

    LARGE ROOT ANGLE1, encoding OsPIN2, is involved in root system architecture in rice

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    Root system architecture is very important for plant growth and crop yield. It is essential for nutrient and water uptake, anchoring, and mechanical support. Root growth angle (RGA) is a vital constituent of root system architecture and is used as a parameter for variety evaluation in plant breeding. However, little is known about the underlying molecular mechanisms that determine root growth angle in rice (Oryza sativa). In this study, a rice mutant large root angle1 (lra1) was isolated and shown to exhibit a large RGA and reduced sensitivity to gravity. Genome resequencing and complementation assays identified OsPIN2 as the gene responsible for the mutant phenotypes. OsPIN2 was mainly expressed in roots and the base of shoots, and showed polar localization in the plasma membrane of root epidermal and cortex cells. OsPIN2 was shown to play an important role in mediating root gravitropic responses in rice and was essential for plants to produce normal RGAs. Taken together, our findings suggest that OsPIN2 plays an important role in root gravitropic responses and determining the root system architecture in rice by affecting polar auxin transport in the root tip

    Circulating tumor DNA clearance predicts prognosis across treatment regimen in a large real-world longitudinally monitored advanced non-small cell lung cancer cohort

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    Background: Although growth advantage of certain clones would ultimately translate into a clinically visible disease progression, radiological imaging does not reflect clonal evolution at molecular level. Circulating tumor DNA (ctDNA), validated as a tool for mutation detection in lung cancer, could reflect dynamic molecular changes. We evaluated the utility of ctDNA as a predictive and a prognostic marker in disease monitoring of advanced non-small cell lung cancer (NSCLC) patients.Methods: This is a multicenter prospective cohort study. We performed capture-based ultra-deep sequencing on longitudinal plasma samples utilizing a panel consisting of 168 NSCLC-related genes on 949 advanced NSCLC patients with driver mutations to monitor treatment responses and disease progression. The correlations between ctDNA and progression-free survival (PFS)/overall survival (OS) were performed on 248 patients undergoing various treatments with the minimum of 2 ctDNA tests.Results: The results of this study revealed that higher ctDNA abundance (P=0.012) and mutation count (P=8.5x10(-4)) at baseline are associated with shorter OS. We also found that patients with ctDNA clearance, not just driver mutation clearance, at any point during the course of treatment were associated with longer PFS (P=2.2x10(-1)6, HR 0.28) and OS (P=4.5x10(-6), HR 0.19) regardless of type of treatment and evaluation schedule.Conclusions: This prospective real-world study shows that ctDNA clearance during treatment may serve as predictive and prognostic marker across a wide spectrum of treatment regimens

    The Crest Phenotype in Chicken Is Associated with Ectopic Expression of HOXC8 in Cranial Skin

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    The Crest phenotype is characterised by a tuft of elongated feathers atop the head. A similar phenotype is also seen in several wild bird species. Crest shows an autosomal incompletely dominant mode of inheritance and is associated with cerebral hernia. Here we show, using linkage analysis and genome-wide association, that Crest is located on the E22C19W28 linkage group and that it shows complete association to the HOXC-cluster on this chromosome. Expression analysis of tissues from Crested and non-crested chickens, representing 26 different breeds, revealed that HOXC8, but not HOXC12 or HOXC13, showed ectopic expression in cranial skin during embryonic development. We propose that Crest is caused by a cis-acting regulatory mutation underlying the ectopic expression of HOXC8. However, the identification of the causative mutation(s) has to await until a method becomes available for assembling this chromosomal region. Crest is unfortunately located in a genomic region that has so far defied all attempts to establish a contiguous sequence

    Recent research on association between gene polymorphisms of IL-28B and other cytokines and HCV infection

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    It has been confirmed that the body′s response to hepatitis C virus (HCV) is not only associated with virus, but also associated with some cytokines and their gene polymorphisms. In this paper, the current research on some cytokines associated with HCV and their gene polymorphisms is reviewed. And it is shown that interleukin-28B is closely associated with the course and prognosis of chronic hepatitis C (CHC). Therefore, it is of great significance for the clinical diagnosis and treatment of CHC to investigate host cytokines and their gene polymorphisms
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