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Microbes of the phylum Aigarchaeota are widely distributed in geothermal environments, but their physiological and ecological roles are poorly understood. Here we analyze six Aigarchaeota metagenomic bins from two circumneutral hot springs in Tengchong, China, to reveal that they are either strict or facultative anaerobes, and most are chemolithotrophs that can perform sulfide oxidation. Applying comparative genomics to the Thaumarchaeota and Aigarchaeota, we find that they both originated from thermal habitats, sharing 1154 genes with their common ancestor. Horizontal gene transfer played a crucial role in shaping genetic diversity of Aigarchaeota and led to functional partitioning and ecological divergence among sympatric microbes, as several key functional innovations were endowed by Bacteria, including dissimilatory sulfite reduction and possibly carbon monoxide oxidation. Our study expands our knowledge of the possible ecological roles of the Aigarchaeota and clarifies their evolutionary relationship to their sister lineage Thaumarchaeota.

We investigate the energy band structure and transport properties of electrons in superlattice structure based on semi-Dirac material with one-dimensional periodic potentials of square barriers. The influence of different parameters on transmission probability in superlattice structure is studied. It is found that two new Dirac points are formed in the superlattice structure by adjusting the gap parameter. The position of the new Dirac points can be regulated by changing the size of the potential barrier, the ratio of well width to barrier width, and the gap parameter. Some forbidden bands appear in the transmission probability, the location and width of the forbidden bands can be regulated by changing the system parameters. [ABSTRACT FROM AUTHOR]

Cyanobacteriota , the sole prokaryotes capable of oxygenic photosynthesis (OxyP), occupy a unique and pivotal role in Earth's history. While the notion that OxyP may have originated from Cyanobacteriota is widely accepted, its early evolution remains elusive. Here, by using both metagenomics and metatranscriptomics, we explore 36 metagenome-assembled genomes from hot spring ecosystems, belonging to two deep-branching cyanobacterial orders: Thermostichales and Gloeomargaritales. Functional investigation reveals that Thermostichales encode the crucial thylakoid membrane biogenesis protein, vesicle-inducing protein in plastids 1 (Vipp1). Based on the phylogenetic results, we infer that the evolution of the thylakoid membrane predates the divergence of Thermostichales from other cyanobacterial groups and that Thermostichales may be the most ancient lineage known to date to have inherited this feature from their common ancestor. Apart from OxyP, both lineages are potentially capable of sulfide-driven AnoxyP by linking sulfide oxidation to the photosynthetic electron transport chain. Unexpectedly, this AnoxyP capacity appears to be an acquired feature, as the key gene sqr was horizontally transferred from later-evolved cyanobacterial lineages. The presence of two D1 protein variants in Thermostichales suggests the functional flexibility of photosystems, ensuring their survival in fluctuating redox environments. Furthermore, all MAGs feature streamlined phycobilisomes with a preference for capturing longer-wavelength light, implying a unique evolutionary trajectory. Collectively, these results reveal the photosynthetic flexibility in these early-diverging cyanobacterial lineages, shedding new light on the early evolution of Cyanobacteriota and their photosynthetic processes. [ABSTRACT FROM AUTHOR]

The Andreev reflection in topological nodal-line semimetal–superconductor (TNLSM–SC) junctions is studied based on the Landauer–Büttiker formula combined with the non-equilibrium Green's function method. It is found that the Andreev reflection coefficient can reach large values of several tens for a TNLSM–SC junction. In the energy gap, two new peaks for the Andreev reflection appear. Outside the energy gap, the Andreev reflection shows a quasi-periodic variation. With the incident energy increasing, the Andreev reflection decreases periodically. This phenomenon originates from the peculiar energy spectrum of the TNLSMs. The value and quasi-period of the Andreev reflection coefficient depend on the size of the system in different directions. These anomalous Andreev reflections are helpful to study the transport properties in normal metal–superconductor junctions. [ABSTRACT FROM AUTHOR]

Objectives: CD4+ T cell helper and regulatory function in human cancers has been well characterised. However, the definition of tumor‐infiltrating CD4+ T cell exhaustion and how it contributes to the immune response and disease progression in human gastric cancer (GC) remain largely unknown. Methods: A total of 128 GC patients were enrolled in the study. The expression of CD39 and PD‐1 on CD4+ T cells in the different samples was analysed by flow cytometry. GC‐infiltrating CD4+ T cell subpopulations based on CD39 expression were phenotypically and functionally assessed. The role of CD39 in the immune response of GC‐infiltrating T cells was investigated by inhibiting CD39 enzymatic activity. Results: In comparison with CD4+ T cells from the non‐tumor tissues, significantly more GC‐infiltrating CD4+ T cells expressed CD39. Most GC‐infiltrating CD39+CD4+ T cells exhibited CD45RA−CCR7− effector–memory phenotype expressing more exhaustion‐associated inhibitory molecules and transcription factors and produced less TNF‐α, IFN‐γ and cytolytic molecules than their CD39−CD4+ counterparts. Moreover, ex vivo inhibition of CD39 enzymatic activity enhanced their functional potential reflected by TNF‐α and IFN‐γ production. Finally, increased percentages of GC‐infiltrating CD39+CD4+ T cells were positively associated with disease progression and patients' poorer overall survival. Conclusion: Our study demonstrates that CD39 expression defines GC‐infiltrating CD4+ T cell exhaustion and their immunosuppressive function. Targeting CD39 may be a promising therapeutic strategy for treating GC patients. [ABSTRACT FROM AUTHOR]

The diffusion and accumulation behaviour of hydrogen in X70 pipeline steel were investigated via hydrogen permeation test, hydrogen diffusion simulation, and hydrogen content test technology in a simulated coal gas environment (4 MPa total pressure, 0.2 MPa hydrogen partial pressure). The mechanical properties of the X70 pipeline steel substrate and weld in a simulated coal gas environment were also analyzed through impact toughness test, crack propagation test, notch tensile test, and slow strain rate tensile test. Experimental results show that hydrogen absorbed on the X70 steel surface in a simulated coal gas environment spreads into the inside of the X70 steel, and the internal diffusion hydrogen mass fraction is 1.9×10-7 after reaching a steady state. Compared with the original performance in air, there is no decline in the impact performance, notched tensile and slow strain rate tensile strength, plasticity, and damage tolerance of the X70 pipeline steel substrate and weld in simulated coal gas. Results show that in a coal gas environment, X70 steel has a lower risk of hydrogen embrittlement.

Performing the non-equilibrium Green's function method, we calculate the Seebeck coefficient (S) and the thermoelectrical figure of merit (Z T) in the quantum anomalous Hall insulator-topological superconductor-quantum anomalous Hall insulator hybrid structure with temperature gradient. It is found that a high thermoelectrical figure of merit can be achieved with the helical topological superconductor phase. The S and the Z T are mainly affected by the temperature and the device size. At a certain temperature and the right device size, the Seebeck coefficient and the figure of merit can reach very high values. [ABSTRACT FROM AUTHOR]

[Cd(C15H13N5)2Cl2], monoclinic, C2/c (no. 15), a = 15.6291(6) Å, b = 12.8859(4) Å, c = 14.7622(5) Å, β = 97.781(3)°, V = 2945.65(18) Å3, Z = 4, Rgt(F) = 0.0381, ωRref(F2) = 0.0738, T = 293(2) K.

A robust dead-beat synchronization method was presented for discrete chaotic systems using adaptive channel blind equalization and dead-beat chaotic synchronization. This method utilizes chaotic synchronization error as the en- ergy function and evolutionary programming to train the RNN, whose output was used as the driving signal for the cha- otic receiver. Furthermore, based on the robust dead-beat synchronization method, a new secure communication method was proposed.