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At present, public databases house an extensive repository of transcriptome data, with the volume continuing to grow at an accelerated pace. Utilizing these data effectively is a shared interest within the scientific community. In this study, we introduced a novel strategy that harnesses SNPs and InDels identified from transcriptome data, combined with sample metadata from databases, to effectively screen for molecular markers correlated with traits. We utilized 228 transcriptome datasets of Eriocheir sinensis from the NCBI database and employed the Genome Analysis Toolkit software to identify 96 388 SNPs and 20 645 InDels. Employing the genome-wide association study analysis, in conjunction with the gender information from databases, we identified 3456 sex-biased SNPs and 639 sex-biased InDels. The KOG and KEGG annotations of the sex-biased SNPs and InDels revealed that these genes were primarily involved in the metabolic processes of E. sinensis. Combined with SnpEff annotation and PCR experimental validation, a highly sex-biased SNP located in the Kelch domain containing 4 (Klhdc4) gene, CHR67-6415071, was found to alter the splicing sites of Klhdc4, generating two splice variants, Klhdc4_a and Klhdc4_b. Additionally, Klhdc4 exhibited robust expression across the ovaries, testes, and accessory glands. The sex-biased SNPs and InDels identified in this study are conducive to the development of unisexual cultivation methods for E. sinensis, and the alternative splicing event caused by the sex-biased SNP in Klhdc4 may serve as a potential mechanism for sex regulation in E. sinensis. The analysis strategy employed in this study represents a new direction for the rational exploitation and utilization of transcriptome data in public databases.
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Phonons play a crucial role in many properties of solid-state systems, and it is expected that topological phonons may lead to rich and unconventional physics. On the basis of the existing phonon materials databases, we have compiled a catalog of topological phonon bands for more than 10,000 three-dimensional crystalline materials. Using topological quantum chemistry, we calculated the band representations, compatibility relations, and band topologies of each isolated set of phonon bands for the materials in the phonon databases. Additionally, we calculated the real-space invariants for all the topologically trivial bands and classified them as atomic or obstructed atomic bands. We have selected more than 1000 "ideal" nontrivial phonon materials to motivate future experiments. The datasets were used to build the Topological Phonon Database.
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Eriocheir sinensis, a key species in China's freshwater aquaculture, is threatened by various diseases, which were verified to be closely associated with oxidative stress. This study aimed to investigate the response of E. sinensis to hydrogen peroxide (H2O2)-induced oxidative stress to understand the biological processes behind these diseases. Crabs were exposed to different concentrations of H2O2 and their antioxidant enzyme activities and gene expressions for defense and immunity were measured. Results showed that activities of antioxidant enzymes-specificallysuperoxide dismutase (SOD), catalase (CAT), total antioxidant capacity(T-AOC), glutathione (GSH), and glutathione peroxidase (GSH-Px)-varied with exposure concentration and duration, initially increasing then decreasing. Notably, SOD, GSH-Px, and T-AOC activities dropped below control levels at 96 h. Concurrently, oxidative damage markers, including malondialdehyde (MDA), H2O2, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, increased with exposure duration. The mRNA expression of SOD, CAT, and GSH-Px also showed an initial increase followed by a decrease, peaking at 72 h. The upregulation of phenoloxidaseloxidase (proPO) and peroxinectin (PX) was also detected, but proPO was suppressed under high levels of H2O2. Heat shock protein 70 (HSP70) expression gradually increased with higher H2O2 concentrations, whereas induced nitrogen monoxide synthase (iNOS) was upregulated but decreased at 96 h. These findings emphasize H2O2's significant impact on the crab's oxidative and immune responses, highlighting the importance of understanding cellular stress responses for disease prevention and therapy development.
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The presence of topological flat minibands in moiré materials provides an opportunity to explore the interplay between topology and correlation. In this work, we study moiré minibands in topological insulator films with two hybridized surface states under a moiré superlattice potential created by two-dimensional insulating materials. We show the lowest conduction (highest valence) Kramers' pair of minibands can be Z 2 non-trivial when the minima (maxima) of moiré potential approximately form a hexagonal lattice with six-fold rotation symmetry. Coulomb interaction can drive the non-trivial Kramers' minibands into the quantum anomalous Hall state when they are half-filled, which is further stabilized by applying external gate voltages to break inversion. We propose the monolayer Sb2 on top of Sb2Te3 films as a candidate based on first principles calculations. Our work demonstrates the topological insulator based moiré heterostructure as a potential platform for studying interacting topological phases.
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Hydrogen peroxide (H2O2), a prevalent reactive oxygen species (ROS) found in natural aquatic environments, has garnered significant attention for its potential toxicity in fish. However, the molecular mechanisms underlying this toxicity are not yet comprehensively understood. This study aimed to assess H2O2-induced liver dysfunction in common carp (Cyprinus carpio) and elucidate the underlying molecular mechanisms via biochemical and transcriptomic analyses. Common carp were divided into normal control (NC) and H2O2-treated groups (1 mM H2O2), the latter of which was exposed to H2O2 for 1 h per day over a period of 14 days. Serum biochemical analyses indicated that exposure to H2O2 resulted in moderate liver damage, characterized by elevated alanine aminotransferase (ALT) activity and lowered albumin (Alb) level. Concurrently, H2O2 exposure induced oxidative stress and modified the hepatic metabolic enzyme levels. Transcriptome analysis highlighted that 1358 and 1188 genes were significantly downregulated and upregulated, respectively, in the H2O2-treated group. These differentially expressed genes (DEGs) were significantly enriched in protein synthesis and a variety of metabolic functions such as peptide biosynthetic processes, protein transport, ribonucleoprotein complex biogenesis, oxoacid metabolic processes, and tricarboxylic acid metabolic processes. Dysregulation of protein synthesis is principally associated with the downregulation of three specific pathways: ribosome biogenesis, protein export, and protein processing in the endoplasmic reticulum (ER). Furthermore, metabolic abnormalities were primarily characterized by inhibition of the citrate cycle (TCA) and fatty acid biosynthesis. Significantly, anomalies in both protein synthesis and metabolic function may be linked to aberrant regulation of the insulin signaling pathway. These findings offer innovative insights into the mechanisms underlying H2O2 toxicity in aquatic animals, contributing to the assessment of ecological risks.
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Carpas , Hepatopatías , Animales , Peróxido de Hidrógeno/farmacología , Carpas/metabolismo , Estrés Oxidativo , Perfilación de la Expresión Génica , Hígado/metabolismo , Hepatopatías/metabolismoRESUMEN
Eco-friendly photocatalysts for water splitting, highly efficient in oxygen/hydrogen evolution reactions, hold great promise for the storage of inexhaustible solar energy and address environmental challenges. However, current common photocatalysts rarely exhibit both H2 and O2 production performances unless some regulatory measures, such as strain engineering, are implemented. Additionally, the extensive utilization of flexible electronics remains constrained by their high Young's modulus. Herein, on the basis of density functional theory calculations, we identify a novel spontaneous oxygen-producing two-dimensional Ca(BiO2)2 material, which can efficiently regulate the electronic structures of the surface active sites, optimize the reaction pathways, reduce the reaction energy barriers, and boost the overall water-splitting activity through biaxial strain modulation. In detail, an unstrained Ca(BiO2)2 monolayer not only possesses a suitable band gap value (2.02 eV) to fulfill the photocatalytic water-splitting band edge relationships but also holds favorable transport properties, excellent optical absorption across the visible light spectrum, and spontaneous oxygen production under neutral conditions. More excitingly, under application of a 7% biaxial tensile strain modulation with an ideal biaxial strength of 32.35 GPa nm, the Ca(BiO2)2 monolayer not only maintains its structural integrity but also exhibits a completely spontaneous reaction for photocatalytic hydrogen precipitation with superior optical absorption. This can primarily be attributed to the substantial reduction of the potential barrier through strain engineering as well as the weakening of bond energy resulting from changes of the adsorption site as calculated by crystal orbital Hamiltonian population analysis. This flexible stretchable electronic modulated the photocatalyst behavior and bond energy of O-Bi and O-Ca interactions, offering outstanding potential for photocatalytic water spontaneous oxygen and hydrogen evolution among all of the reported metal oxides, and is more likely to become a promising candidate for future flexible electronic devices.
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Transposable elements (TEs) are mobile genetic elements that exist in the host genome and exert considerable influence on the evolution of the host genome. Since crustaceans, including decapoda, are considered ideal models for studying the relationship between adaptive evolution and TEs, TEs were identified and classified in the genomes of eight decapoda species and one diplostraca species (as the outgroup) using two strategies, namely homology-based annotation and de novo annotation. The statistics and classification of TEs showed that their proportion in the genome and their taxonomic composition in decapoda were different. Moreover, correlation analysis and transcriptome data demonstrated that there were more PIF-Harbinger TEs in the genomes of Eriocheir sinensis and Scylla paramamosain, and the expression patterns of PIF-Harbingers were significantly altered under air exposure stress conditions. These results signaled that PIF-Harbingers expanded in the genome of E. sinensis and S. paramamosain and might be related to their air exposure tolerance levels. Meanwhile, sequence alignment revealed that some Jockey-like sequences (JLSs) with high similarity to specific regions of the White spot syndrome virus (WSSV) genome existed in all eight decapod species. At the same time, phylogenetic comparison exposed that the phylogenetic tree constructed by JLSs was not in agreement with that of the species tree, and the distribution of each branch was significantly different. The abovementioned results signaled that these WSSV-specific JLSs might transfer horizontally and contribute to the emergence of WSSV. This study accumulated data for expanding research on TEs in decapod species and also provided new insights and future direction for the breeding of stress-resistant and disease-resistant crab breeds.
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Decápodos , Virus del Síndrome de la Mancha Blanca 1 , Animales , Elementos Transponibles de ADN/genética , Filogenia , Genómica , Virus del Síndrome de la Mancha Blanca 1/genética , Decápodos/genética , Evolución MolecularRESUMEN
Butyrate (BU), a gut microbiota-derived metabolite, has been reported to play a neuroprotective role in Parkinson's disease (PD). However, the specific molecular mechanism of BU has not been fully interpreted. This work aimed to verify the protective effects of BU against MPTP/MPP+ -induced neurotoxicity and explore the mechanisms involved. The results showed that BU protected against MPTP-induced motor dysfunction and decreased tyrosine hydroxylase (TH) and dopamine transporter (DAT) levels. Additionally, BU pretreatment improved PC12 cell viability and reduced MPP+ -induced PC12 cell apoptosis. BU treatment also attenuated MPP+ -stimulated oxidative stress and inflammatory response in PC12 cells. Furthermore, BU inhibited MPTP/MPP+ -induced hyperactivation of the JAK2/STAT3 signaling in mice and PC12 cells. Besides, a JAK2 agonist, Coumermycin A1 (C-A1), substantially reversed BU-mediated inhibition on JAK2/STAT3 phosphorylation in MPP+ -challenged PC12 cells and abated BU-induced repression on MPP+ -triggered apoptosis, oxidative stress, and inflammatory response in PC12 cells. To sum up, BU might exert neuroprotective effects against MPP+ /MPTP-induced neurotoxicity by inactivating the JAK2/STAT3 signaling.
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Microbioma Gastrointestinal , Intoxicación por MPTP , Fármacos Neuroprotectores , Enfermedad de Parkinson , Ratas , Ratones , Animales , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/metabolismo , Butiratos , Intoxicación por MPTP/tratamiento farmacológico , Intoxicación por MPTP/metabolismo , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Transducción de Señal , Células PC12 , Ratones Endogámicos C57BLRESUMEN
The unprecedented global increase in the anthropogenic-derived nitrogen (N) input may have profound effects on phosphorus (P) dynamics and may potentially lead to enhanced eutrophication as demonstrated in short-term mesocosm experiments. However, the role of N-influenced P release is less well studied in large-scale ecosystems. To gain more insight into ecosystem effects, we conducted a five-year large-scale experiment in ten ponds (700-1000 m2 each) with two types of sediments and five targeted total N concentrations (TN) by adding NH4Cl fertilizer (0.5, 1, 5, 10, and 25 mg N L-1). The results showed that: (â °) The sediment P release increased significantly when TN exceeded 10-25 mg N L-1. (â ±) The most pronounced sediment P release increase occurred in summer and from sediments rich in organic matter (OMSed). (â ²) TN, algal biomass, fish biomass, non-algal turbidity, sediment pH, and OMSed were the dominant factors explaining the sediment P release, as suggested by piecewise structural equation modeling. We propose several mechanisms that may have stimulated P release, i.e. high ammonium input causes a stoichiometric N:P imbalance and induce alkaline phosphatase production and dissolved P uptake by phytoplankton, leading to enhanced inorganic P diffusion gradient between sediment and water; higher pelagic fish production induced by the higher phytoplankton production may have led increased sediment P resuspension through disturbance; low oxygen level in the upper sediment caused by nitrification and organic decomposition of the settled phytoplankton and, finally, long-term N application-induced sediment acidification as a net effect of ammonium hydrolysis, nitrification, denitrification; The mechanisms revealed by this study shed new light on the complex processes underlying the N-stimulated sediment P release, with implications also for the strategies used for restoring eutrophicated lakes.
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Compuestos de Amonio , Lagos , Animales , Lagos/química , Ecosistema , Fósforo/análisis , Sedimentos Geológicos , Eutrofización , Nitrógeno/análisis , ChinaRESUMEN
Objective: Arteriolosclerosis cerebral small vessel disease (CSVD) is a common type of CSVD. This study aimed to explore the factors associated with cognitive function and total MRI burden related to the disease. Methods: The demographic characteristics, clinical manifestations, cognitive function score, Barthel Index (BI), blood test index, and follow-up results of arteriolosclerosis CSVD patients treated for the first time in our hospital from January 2014 to August 2022 were collected. White matter hyperintensity (WMH) Fazekas score, total MRI burden, and cerebral atrophy grade were evaluated according to brain MRI findings. Factors associated with CSVD cognitive function were analyzed by binary logistic regression. The correlative factors related to the total MRI burden of CSVD were analyzed by ordered multiple logistic regression. Results: A total of 146 patients were included in this study, of which 132 cases (90.4%) had hypertension. There were 108 patients (74.0%) with cognitive dysfunction, 97 patients (66.4%) with balance and gait disorders, and 83 patients (56.8%) with moderate-to-severe dependence in daily life (BI ≤ 60 points). Of 146 patients, 79 (54.1%) completed clinical and imaging follow-ups for a median of 3 years. The number of patients with cognitive impairment and BI ≤ 60 points after follow-up significantly increased compared with the first admission (P < 0.001). There were also significant differences in total MRI burden (P = 0.001), WMH Fazekas score, and cerebral atrophy grade (P < 0.001). Mean age (P = 0.012), median deep WMH Fazekas score (P = 0.028), and median deep (P < 0.001) and superficial (P =0.002) cerebral atrophy grade of patients with cognitive impairment at first admission were all higher than those with non-cognitive impairment. Multivariate analysis showed that deep cerebral atrophy was independently and significantly associated with cognitive impairment of CSVD (P = 0.024), and hypertension was significantly and independently associated with total MRI burden (P = 0.001). Conclusion: The disease course of arteriolosclerosis CSVD may be related to cognitive function and total MRI burden. Deep cerebral atrophy was an independent risk factor for cognitive dysfunction in arteriolosclerosis CSVD, and hypertension was an independent risk factor for total MRI burden.
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DM domain genes are a group of transcription factors that are integral to sexual development and its evolution in metazoans. Their functions and regulatory mechanisms are not well understood in Malacostraca (crabs and crayfish) while these sex regulators have been widely identified in the past decade. In this study, the Dmrt family was investigated in the decapod crab, Eriocheir sinensis. We find that most members of the EsDmrt family begin to enrich around the juvenile 1 stage. In reproductive organs, EsDsx1, EsDsx2, EsiDMY and EsiDmrt1a highly express in the male-specific androgenic gland (AG), while EsDmrt-like, EsDsx-like, EsDmrt11E, and EsiDmrt1b show relatively high expression in testis. Also, we find the highly aberrant expression of EsiDMY and EsiDmrt1a in the chimeric AG, strongly indicating their function in AG development. Moreover, RNA interference of EsDsx1, EsiDMY, and EsiDmrt1a results in a significant decrease in transcription of the Insulin-like androgenic hormone (IAG), respectively. Our findings suggest that Dmrt genes in E. sinensis primarily function in male sexual differentiation, especially in AG development. Besides, this study identifies two unique groups of Dmrt genes in Malacostraca: Dsx and iDmrt1. In Malacostraca Dsx, we uncover a cryptic mutation in the eight zinc motif-specific residues, which were firmly believed to be invariant across the Dmrt family. This mutation sets the Malacostraca Dsx apart from all the other Dmrt genes and implies a different way of transcriptional regulation. Genes from the iDmrt1 group show phylogenetical limitation to the malacostracan species and underwent positive selection, suggesting their highly specialized gene function to this class. Based on these findings, we propose that Dsx and iDmrt1 in Malacostraca have developed unique transcriptional regulation mechanisms to facilitate AG development. We hope that this study would contribute to our understandings of sexual development in Malacostraca and provide new insights into the evolutionary history of the Dmrt family.
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Electronic structure calculations indicate that the Sr2FeSbO6 double perovskite has a flat-band set just above the Fermi level that includes contributions from ordinary subbands with weak kinetic electron hopping plus a flat subband that can be attributed to the lattice geometry and orbital interference. To place the Fermi energy in that flat band, electron-doped samples with formulas Sr2-xLaxFeSbO6 (0 ≤ x ≤ 0.3) were synthesized, and their magnetism and ambient temperature crystal structures were determined by high-resolution synchrotron X-ray powder diffraction. All materials appear to display an antiferromagnetic-like maximum in the magnetic susceptibility, but the dominant spin coupling evolves from antiferromagnetic to ferromagnetic on electron doping. Which of the three subbands or combinations is responsible for the behavior has not been determined.
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The Chinese mitten crab, Eriocheir sinensis, is a vital freshwater aquaculture species in China, however, is also facing various crab disease threats. In the present study, we identify three novel variable lymphocyte receptor-like (VLR-like) genes-VLR-like1, VLR-like3 and VLR-like4-from E. sinensis, which play vital roles in adaptive immune system of agnathan vertebrates. The bacterial challenge, bacterial binding and antibacterial-activity experiments were applied to study immune functions of VLR-likes, and the transcriptomic data from previous E. sinensis bacterial challenge experiments were analyzed to speculate the possible signaling pathway. VLR-like1 and VLR-like4 can respond to Staphylococcus aureus challenge and inhibit S. aureus specifically. VLR-like1 and VLR-like4 possess broad-spectrum bacteria-binding ability whereas VLR-like3 do not. VLR-likes in E. sinensis could associate with the Toll-like receptor (TLR) signaling pathway. The above results suggest that VLR-likes defend against bacteria invasion though exerting anti-bacteria activity, and probably connect with the TLR signaling pathway. Furthermore, studying the immune functions of these VLR-likes will provide a new insight into the disease control strategy of crustacean culture.
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Proteínas de Artrópodos , Braquiuros , Braquiuros/inmunología , Braquiuros/microbiología , Proteínas de Artrópodos/inmunología , Transcriptoma/inmunología , Staphylococcus aureus/fisiologíaRESUMEN
Background: Endovascular treatment (EVT) is one of the effective treatment procedure for the symptomatic intracranial atherosclerotic stenosis (sICAS). Aim and methods: We evaluated the efficacy and safety of individualized endovascular treatment for sICAS patients. Clinical and imaging follow-ups were carried out to collect the data of 29 sICAS patients after 6 months of individualized endovascular treatment. Different treatment strategies are selected based on arterial access and lesion morphology of patients. If standard surgical path, narrow artery straight, stenosis length ≤10 mm, then the appropriate specifications of balloon-mounted stent (BMS) treatment. the surgical path is tortuous, the narrow artery is curved, the angle is apparent, the diameter of the near and far ends is significantly different, or the length of the stenosis is >10 mm, self-expanding stent (SES) with appropriate specifications is selected for treatment. If the narrowed artery is hyper flexed and the surgeon deems stenting inappropriate, balloon dilation angioplasty (BDA) treatment is chosen. Results and conclusion: 31 lesions of 29 sICAS patients received endovascular treatment. The median age was 61 years (IQR 54-69 years). The median preoperative stenosis was 90% (IQR 80-95%), and the mean stenosis length was (8.10 ± 3.27) mm. The most commonly used surgical procedure was Balloon-Mounted Stent (BMS) in 19 cases (65.52%), Self-expanding Stent (SES) in seven cases (24.14%), Balloon Dilation Angioplasty (BDA) in three cases (10.34%). (11.86 + 1.46 mm) was greater than that in the BMS group (6.14 + 1.59 mm) (P < 0.001). The median stenosis was 90% (IQR 80-92.5%) in the BMS group, lower than 99% (IQR 95-100%) in the SES group (P < 0.001). The median post-operative residual stenosis was 20% (IQR 15-25%), significantly improved compared with preoperative (P < 0.001). The success rate of the surgical technique was 93.10% (27/29). One patient (3.45%) had IS recurrence within 48 h after surgery, and the restenosis rate within 6 months after surgery was 6.90% (2/29). No patient died or had recurrent IS. Our data demonstrated that individualized endovascular treatment method could be potentially significant and safe for sICAS patients. This study will provide an important reference for the endovascular treatment of sICAD.
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BACKGROUND: P-selectin is a molecule participating in the inflammatory response through mediating cellular adhesion and essential for wound repair. However, studies regarding P-selectin in Bivalvia are rare. This study identified 90 P-selectin genes among nine bivalve genomes and classified them into 4 subfamilies according to phylogenetic analysis. RESULTS: Notable P-selectin gene expansion was observed in two Venerida species, Sinonovacula constricta and Mercenaria mercenaria. The synteny analysis revealed that P-selectin gene expansion was mostly caused by tandem duplication. In addition, the expression profiles of P-selectin genes in S. constricta showed that many P-selectins were specifically highly expressed in the gills, and the P-selectin expression patterns changed dramatically under low salt stress and ammonia nitrogen stress. CONCLUSIONS: The massive expansion of P-selectins may facilitate the tolerance to environmental stresses. This study sheds light on the characterizations and expression profiles of P-selectin genes in Bivalvia and provides an integrated framework for further investigation of the role of P-selectins in the environmental tolerance of bivalves.
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Mercenaria , Amoníaco , Animales , Genómica , Mercenaria/genética , Selectina-P/genética , FilogeniaRESUMEN
Exosomal programmed cell death ligand 1 (exoPD-L1) has emerged as a promising biomarker for cancer diagnosis and immunotherapy outcome prediction. However, the existing quantitation methods are incapable of addressing the heterogeneity of exoPD-L1 glycosylation, which has been demonstrated to be the institutional basis for PD-L1/PD-1 interaction and the crucial participant in inhibiting the activity of CD8+ T cells. Herein, an aptamer- and lectin-induced proximity ligation assay combined with quantitative real-time polymerase chain reaction for precise quantitation of glycosylated exoPD-L1 is developed. Leveraging the metabolism-free lectin labeling of glycosylation, the glycosylation-independent aptamer tagging of PD-L1, and excellent selectivity of dual-recognition, this method enables glycosylated exoPD-L1 quantitation with high sensitivity and selectivity in a wash-free manner. As a result, this method is able to distinguish the levels of glycosylated exoPD-L1 between healthy donors and cancer patients with sensitivity and specificity of 100%. Compared with the total circulating exoPD-L1 level, glycosylated exoPD-L1 is for the first time identified to be a more reliable biomarker for tumor diagnosis. Overall, this strategy holds a great potential for revealing the significance of exoPD-L1 glycosylation and converting glycosylated exoPD-L1 into a reliable clinical indicator.
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Antígeno B7-H1 , Neoplasias , Antígeno B7-H1/metabolismo , Biomarcadores de Tumor/metabolismo , Linfocitos T CD8-positivos/metabolismo , Glicosilación , Humanos , Lectinas/metabolismo , Ligandos , Neoplasias/diagnóstico , Receptor de Muerte Celular Programada 1/metabolismoRESUMEN
The superconducting analogue to the semiconducting diode, the Josephson diode, has long been sought with multiple avenues to realization being proposed by theorists1-3. Showing magnetic-field-free, single-directional superconductivity with Josephson coupling, it would serve as the building block for next-generation superconducting circuit technology. Here we realized the Josephson diode by fabricating an inversion symmetry breaking van der Waals heterostructure of NbSe2/Nb3Br8/NbSe2. We demonstrate that even without a magnetic field, the junction can be superconducting with a positive current while being resistive with a negative current. The ΔIc behaviour (the difference between positive and negative critical currents) with magnetic field is symmetric and Josephson coupling is proved through the Fraunhofer pattern. Also, stable half-wave rectification of a square-wave excitation was achieved with a very low switching current density, high rectification ratio and high robustness. This non-reciprocal behaviour strongly violates the known Josephson relations and opens the door to discover new mechanisms and physical phenomena through integration of quantum materials with Josephson junctions, and provides new avenues for superconducting quantum devices.
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The discovery of new catalysts that are efficient and sustainable is a major research endeavor for many industrial chemical processes. This requires an understanding and determination of the catalytic origins, which remains a challenge. Here, a novel method to identify the position of active sites based on searching for crystalline symmetry-protected obstructed atomic insulators (OAIs) that have metallic surface states is described. The obstructed Wannier charge centers (OWCCs) in OAIs are pinned by symmetries at some empty Wyckoff positions so that surfaces that accommodate these sites are guaranteed to have metallic obstructed surface states (OSSs). It is proposed and confirmed that the OSSs are the catalytic activity origins for crystalline materials. The theory on 2H-MoTe2 , 1T'-MoTe2 , and NiPS3 bulk single crystals is verified, whose active sites are consistent with the calculations. Most importantly, several high-efficiency catalysts are successfully identified just by considering the number of OWCCs and the symmetry. Using the real-space-invariant theory applied to a database of 34 013 topologically trivial insulators, 1788 unique OAIs are identified, of which 465 are potential high-performance catalysts. The new methodology will facilitate and accelerate the discovery of new catalysts for a wide range of heterogeneous redox reactions.
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Topological electronic flattened bands near or at the Fermi level are a promising route towards unconventional superconductivity and correlated insulating states. However, the related experiments are mostly limited to engineered materials, such as moiré systems1-3. Here we present a catalogue of the naturally occuring three-dimensional stoichiometric materials with flat bands around the Fermi level. We consider 55,206 materials from the Inorganic Crystal Structure Database catalogued using the Topological Quantum Chemistry website4,5, which provides their structural parameters, space group, band structure, density of states and topological characterization. We combine several direct signatures and properties of band flatness with a high-throughput analysis of all crystal structures. In particular, we identify materials hosting line-graph or bipartite sublattices-in either two or three dimensions-that probably lead to flat bands. From this trove of information, we create the Materials Flatband Database website, a powerful search engine for future theoretical and experimental studies. We use the database to extract a curated list of 2,379 high-quality flat-band materials, from which we identify 345 promising candidates that potentially host flat bands with charge centres that are not strongly localized on the atomic sites. We showcase five representative materials and provide a theoretical explanation for the origin of their flat bands close to the Fermi energy using the S-matrix method introduced in a parallel work6.