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Topological electronic materials, such as topological insulators, are distinct from trivial materials in the topology of their electronic band structures that lead to robust, unconventional topological states, which could bring revolutionary developments in electronics. This Perspective summarizes developments of topological insulators in various electronic applications including spintronics and magnetoelectronics. We group and analyse several important phenomena in spintronics using topological insulators, including spin–orbit torque, the magnetic proximity effect, interplay between antiferromagnetism and topology, and the formation of topological spin textures. We also outline recent developments in magnetoelectronics such as the axion insulator and the topological magnetoelectric effect observed using different topological insulators. This Perspective discusses the interplay between magnetism and topology in condensed matter.

In the past few decades, due to the rapid development of industry and the rapid growth of population, emissions of pollutants to the environment have increased dramatically, and the demand for drinking water is also increasing. Water treatment is a matter of concern because it is directly related to the health of humans and wildlife. Graphene and its derivatives have potential applications in seawater desalination and wastewater treatment due to their unique pore structure and ionic molecular sieving separation capabilities. Graphene, graphene oxide (GO), and reduced graphene oxide (rGO) can be formulated into nanoporous materials and composites with tunable properties that can be optimized for water filtration. Methods for perforating graphene include ion etching/ion bombardment and electron beam nanometer engraving, which are briefly introduced in this paper. Graphene-based composites further expand the capabilities of graphene in seawater desalination and wastewater treatment, by introducing new features and properties. In this review, the performance improvement of graphene-based separation membranes in decontamination and desalination in recent years is reviewed in detail. This review focuses on improving the performance of graphene-based membranes for separation, decontamination, and seawater desalination applications, by discussing how various modifications and preparation methods impact important performance properties, including water permeance, selectivity, rejection of solutes, membrane mechanical strength, and antifouling characteristics. We also discuss the outlook for future development of graphene-based membranes.

Multimetallic nanoparticles are useful in many fields, yet there are no effective strategies for synthesizing libraries of such structures, in which architectures can be explored in a systematic and site-specific manner. The absence of these capabilities precludes the possibility of comprehensively exploring such systems. We present systematic studies of individual polyelemental particle systems, in which composition and size can be independently controlled and structure formation (alloy versus phase-separated state) can be understood. We made libraries consisting of every combination of five metallic elements (Au, Ag, Co, Cu, and Ni) through polymer nanoreactor–mediated synthesis. Important insight into the factors that lead to alloy formation and phase segregation at the nanoscale were obtained, and routes to libraries of nanostructures that cannot be made by conventional methods were developed.

Background Antibiotic-resistant pathogens are challenging treatment of infections worldwide. Urban sewage is potentially a major conduit for dissemination of antibiotic resistance genes into various environmental compartments. However, the diversity and abundance of such genes in wastewater are not well known. Methods Here, seasonal and geographical distributions of antibiotic resistance genes and their host bacterial communities from Chinese urban sewage were characterized, using metagenomic analyses and 16S rRNA gene-based Illumina sequencing, respectively. Results In total, 381 different resistance genes were detected, and these genes were extensively shared across China, with no geographical clustering. Seasonal variation in abundance of resistance genes was observed, with average concentrations of 3.27 × 10 11 and 1.79 × 10 12 copies/L in summer and winter, respectively. Bacterial communities did not exhibit geographical clusters, but did show a significant distance-decay relationship ( P  < 0.01). The core, shared resistome accounted for 57.7% of the total resistance genes, and was significantly associated with the core microbial community ( P  < 0.01). The core human gut microbiota was also strongly associated with the shared resistome, demonstrating the potential contribution of human gut microbiota to the dissemination of resistance elements via sewage disposal. Conclusions This study provides a baseline for investigating environmental dissemination of resistance elements and raises the possibility of using the abundance of resistance genes in sewage as a tool for antibiotic stewardship.

A polymer pore template can control the order of assembly of nanoparticles into well-defined stacks and create superlattices. Lin et al. used DNA strands on gold nanoparticles to control interparticle distance. The DNA strands contained modified adenines with more rigid ribose groups that formed stronger base pairs. The height of the stacks of three different types of gold nanoparticle could be changed with different solvents, which in turn changed their optical response. Science , this issue p. 669 Locked DNA strands and micropores are used to assemble nanoparticles with different sizes and shapes into superlattices. DNA programmable assembly has been combined with top-down lithography to construct superlattices of discrete, reconfigurable nanoparticle architectures on a gold surface over large areas. Specifically, the assembly of individual colloidal plasmonic nanoparticles with different shapes and sizes is controlled by oligonucleotides containing “locked” nucleic acids and confined environments provided by polymer pores to yield oriented architectures that feature tunable arrangements and independently controllable distances at both nanometer- and micrometer-length scales. These structures, which would be difficult to construct by other common assembly methods, provide a platform to systematically study and control light-matter interactions in nanoparticle-based optical materials. The generality and potential of this approach are explored by identifying a broadband absorber with a solvent polarity response that allows dynamic tuning of visible light absorption.

Metaplastic breast cancer (MBC) are rare. The survival outcomes of MBC patients after breast conserving surgery plus radiotherapy (BCS+RT) or mastectomy have not been established. The study aimed to compare survival outcomes of MBC patients subjected to BCS+RT or mastectomy therapeutic options. A total of 1197 patients were enrolled in this study. Among them, 439 patients were subjected to BCS+RT, while 758 patients were subjected to mastectomy. After propensity score matching (PSM), the BCS+RT and mastectomy groups consisted of 321 patients, respectively. The univariate and multivariate analysis with a 6-month landmark all indicate that patients receiving BCS+RT has higher OS than patients receiving mastectomy (HR = 0.701,95% CI = 0.496-0.990, P = 0.044; HR = 0.684,95% CI = 0.479-0.977, P = 0.037) while the BCSS was no difference between the two groups (HR = 0.739,95% CI = 0.474-1.153, P = 0.183; HR = 0.741,95% CI = 0.468-1.173, P = 0.200). The BCS+RT therapeutic option exhibits a higher OS in MBC patients compared to the mastectomy approach.

Topological insulators are emergent states of quantum matter that are gapped in the bulk with timereversal symmetry-preserved gapless edge/surface states, adiabatically distinct from conventional materials. By proximity to various magnets and superconductors, topological insulators show novel physics at the interfaces, which give rise to two new areas named topological spintronics and topological quantum computation. Effects in the former such as the spin torques, spin-charge conversion, topological antiferromagnetic spintronics, and skyrmions realized in topological systems will be addressed. In the latter, a superconducting pairing gap leads to a state that supports Majorana fermions states, which may provide a new path for realizing topological quantum computation. Various signatures of Majorana zero modes/edge mode in topological superconductors will be discussed. The review ends by outlooks and potential applications of topological insulators. Topological superconductors that are fabricated using topological insulators with superconductors have a full pairing gap in the bulk and gapless surface states consisting of Majorana fermions. The theory of topological superconductors is reviewed, in close analogy to the theory of topological insulators.

A bstract Through the analysis of null symplectic structure, we derive the condition for integrable Virasoro generators on the covariant phase space of axisymmetric Killing horizons. A weak boundary condition selects a special relationship between the two temperatures for the putative CFT. When the integrability is satisfied for both future and past horizons, the two central charges are equal. At the end we discuss the physical implications.

Summary It is a grand challenge to ensure the food security for a predicted world population of exceeding 9.7 billion by 2050, especially in an era of global climate change, land degradation and biodiversity loss. Current agricultural productions are mainly relying on synthetic chemical fertilisers to boost plant productivity but have undesirable effects on the environment and soil biodiversity. A promising direction in sustainable agriculture is to harness naturally occurring processes of beneficial plant‐associated microbiomes to ensure sustained crop production and global food security. Despite the significant progress made in the development of beneficial microbes as inoculants to enhance plant performance, challenges remain with the translation of knowledge of plant and soil microbiomes to successful microbial products in the agricultural sector. Here, we highlight how fertilizer technology should be renovated by harnessing microbiome‐based innovations to promote plant productivity and contribute to the end of hunger. Conceptual diagrams to harness the plant‐microbe interactions for the development of new microbial products to improve plant performance. We propose to identify the core group of crop‐specific plant signalling molecules under various environmental stresses, and to extract the selected signalling molecules with the capacity to promote activities of beneficial microbes in the rhizosphere. The high‐throughput isolation approach can be used to isolate plant beneficial microbes in a high‐throughput manner, and the isolated bacterial cultures can be used to create various synthetic communities to test their effects on plant performance in controlled and field experiments.

Ferroptosis is a type of programmed cell death dependent on iron. It is different from other forms of cell death such as apoptosis, classic necrosis and autophagy. Ferroptosis is involved in many neurodegenerative diseases. The role of ferroptosis in glutamate-induced neuronal toxicity is not fully understood. To test its toxicity, glutamate (1.25-20 mM) was applied to HT-22 cells for 12 to 48 hours. The optimal experimental conditions occurred at 12 hours after incubation with 5 mM glutamate. Cells were cultured with 3-12 μM ferrostatin-1, an inhibitor of ferroptosis, for 12 hours before exposure to glutamate. The cell viability was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Autophagy was determined by monodansylcadaverine staining and apoptosis by caspase 3 activity. Damage to cell structures was observed under light and by transmission electron microscopy. The release of lactate dehydrogenase was detected by the commercial kit. Reactive oxygen species were measured by flow cytometry. Glutathione peroxidase activity, superoxide dismutase activity and malondialdehyde level were detected by the appropriate commercial kit. Prostaglandin peroxidase synthase 2 and glutathione peroxidase 4 gene expression was detected by real-time quantitative polymerase chain reaction. Glutathione peroxidase 4 and nuclear factor erythroid-derived-like 2 protein expression was detected by western blot analysis. Results showed that ferrostatin-1 can significantly counter the effects of glutamate on HT-22 cells, improving the survival rate, reducing the release of lactate dehydrogenase and reducing the damage to mitochondrial ultrastructure. However, it did not affect the caspase-3 expression and monodansylcadaverine-positive staining in glutamate-injured HT-22 cells. Ferrostatin-1 reduced the levels of reactive oxygen species and malondialdehyde and enhanced superoxide dismutase activity. It decreased gene expression of prostaglandin peroxidase synthase 2 and increased gene expression of glutathione peroxidase 4 and protein expressions of glutathione peroxidase 4 and nuclear factor (erythroid-derived)-like 2 in glutamate-injured HT-22 cells. Treatment of cultured cells with the apoptosis inhibitor Z-Val-Ala-Asp (OMe)-fluoromethyl ketone (2-8 μM), autophagy inhibitor 3-methyladenine (100-400 μM) or necrosis inhibitor necrostatin-1 (10-40 μM) had no effect on glutamate induced cell damage. However, the iron chelator deferoxamine mesylate salt inhibited glutamate induced cell death. Thus, the results suggested that ferroptosis is caused by glutamate-induced toxicity and that ferrostatin-1 protects HT-22 cells from glutamate-induced oxidative toxicity by inhibiting the oxidative stress.