Stress-Induced Metabolic Disorder in Peripheral CD4+ T Cells Leads to Anxiety-like Behavior.

Physical or mental stress leads to neuroplasticity in the brain and increases the risk of depression and anxiety. Stress exposure causes the dysfunction of peripheral T lymphocytes. However, the pathological role and underlying regulatory mechanism of peripheral T lymphocytes in mood disorders have not been well established. Here, we show that the lack of CD4+ T cells protects mice from stress-induced anxiety-like behavior. Physical stress-induced leukotriene B4 triggers severe mitochondrial fission in CD4+ T cells, which further leads to a variety of behavioral abnormalities including anxiety, depression, and social disorders. Metabolomic profiles and single-cell transcriptome reveal that CD4+ T cell-derived xanthine acts on oligodendrocytes in the left amygdala via adenosine receptor A1. Mitochondrial fission promotes the de novo synthesis of purine via interferon regulatory factor 1 accumulation in CD4+ T cells. Our study implicates a critical link between a purine metabolic disorder in CD4+ T cells and stress-driven anxiety-like behavior.

Multiomics analyses reveal a critical role of selenium in controlling T cell differentiation in Crohn's disease.

Inflammatory bowel disease (IBD) mainly includes Crohn's disease (CD) and ulcerative colitis (UC). Immune disorders play an essential role in the pathogenesis of these two IBDs, but the differences in the immune microenvironment of the colon and their underlying mechanisms remain poorly investigated. Here we examined the immunological features and metabolic microenvironment of untreated individuals with IBD by multiomics analyses. Modulation of CD-specific metabolites, particularly reduced selenium, can obviously shape type 1 T helper (Th1) cell differentiation, which is specifically enriched in CD. Selenium supplementation suppressed the symptoms and onset of CD and Th1 cell differentiation via selenoprotein W (SELW)-mediated cellular reactive oxygen species scavenging. SELW promoted purine salvage pathways and inhibited one-carbon metabolism by recruiting an E3 ubiquitin ligase, tripartite motif-containing protein 21, which controlled the stability of serine hydroxymethyltransferase 2. Our work highlights selenium as an essential regulator of T cell responses and potential therapeutic targets in CD.

Tuning the Chern number in quantum anomalous Hall insulators.

A quantum anomalous Hall (QAH) state is a two-dimensional topological insulating state that has a quantized Hall resistance of h/(Ce2) and vanishing longitudinal resistance under zero magnetic field (where h is the Planck constant, e is the elementary charge, and the Chern number C is an integer)1,2. The QAH effect has been realized in magnetic topological insulators3-9 and magic-angle twisted bilayer graphene10,11. However, the QAH effect at zero magnetic field has so far been realized only for C = 1. Here we realize a well quantized QAH effect with tunable Chern number (up to C = 5) in multilayer structures consisting of alternating magnetic and undoped topological insulator layers, fabricated using molecular beam epitaxy. The Chern number of these QAH insulators is determined by the number of undoped topological insulator layers in the multilayer structure. Moreover, we demonstrate that the Chern number of a given multilayer structure can be tuned by varying either the magnetic doping concentration in the magnetic topological insulator layers or the thickness of the interior magnetic topological insulator layer. We develop a theoretical model to explain our experimental observations and establish phase diagrams for QAH insulators with high, tunable Chern number. The realization of such insulators facilitates the application of dissipationless chiral edge currents in energy-efficient electronic devices, and opens up opportunities for developing multi-channel quantum computing and higher-capacity chiral circuit interconnects.

LncRNA CamK-A Regulates Ca2+-Signaling-Mediated Tumor Microenvironment Remodeling.

Cancer cells entail metabolic adaptation and microenvironmental remodeling to survive and progress. Both calcium (Ca2+) flux and Ca2+-dependent signaling play a crucial role in this process, although the underlying mechanism has yet to be elucidated. Through RNA screening, we identified one long noncoding RNA (lncRNA) named CamK-A (lncRNA for calcium-dependent kinase activation) in tumorigenesis. CamK-A is highly expressed in multiple human cancers and involved in cancer microenvironment remodeling via activation of Ca2+-triggered signaling. Mechanistically, CamK-A activates Ca2+/calmodulin-dependent kinase PNCK, which in turn phosphorylates IκBα and triggers calcium-dependent nuclear factor κB (NF-κB) activation. This regulation results in the tumor microenvironment remodeling, including macrophage recruitment, angiogenesis, and tumor progression. Notably, our human-patient-derived xenograft (PDX) model studies demonstrate that targeting CamK-A robustly impaired cancer development. Clinically, CamK-A expression coordinates with the activation of CaMK-NF-κB axis, and its high expression indicates poor patient survival rate, suggesting its role as a potential biomarker and therapeutic target.

Electrical switching of the edge current chirality in quantum anomalous Hall insulators.

A quantum anomalous Hall (QAH) insulator is a topological phase in which the interior is insulating but electrical current flows along the edges of the sample in either a clockwise or counterclockwise direction, as dictated by the spontaneous magnetization orientation. Such a chiral edge current eliminates any backscattering, giving rise to quantized Hall resistance and zero longitudinal resistance. Here we fabricate mesoscopic QAH sandwich Hall bar devices and succeed in switching the edge current chirality through thermally assisted spin-orbit torque (SOT). The well-quantized QAH states before and after SOT switching with opposite edge current chiralities are demonstrated through four- and three-terminal measurements. We show that the SOT responsible for magnetization switching can be generated by both surface and bulk carriers. Our results further our understanding of the interplay between magnetism and topological states and usher in an easy and instantaneous method to manipulate the QAH state.

APC mutations disrupt ß-catenin destruction complex condensates organized by Axin phase separation.

The Wnt/ß-catenin pathway is critical to maintaining cell fate decisions. Recent study showed that liquid-liquid-phase separation (LLPS) of Axin organized the ß-catenin destruction complex condensates in a normal cellular state. Mutations inactivating the APC gene are found in approximately 80% of all human colorectal cancer (CRC). However, the molecular mechanism of the formation of ß-catenin destruction complex condensates organized by Axin phase separation and how APC mutations impact the condensates are still unclear. Here, we report that the ß-catenin destruction complex, which is constructed by Axin, was assembled condensates via a phase separation process in CRC cells. The key role of wild-type APC is to stabilize destruction complex condensates. Surprisingly, truncated APC did not affect the formation of condensates, and GSK 3ß and CK1α were unsuccessfully recruited, preventing ß-catenin phosphorylation and resulting in accumulation in the cytoplasm of CRCs. Besides, we propose that the phase separation ability of Axin participates in the nucleus translocation of ß-catenin and be incorporated and concentrated into transcriptional condensates, affecting the transcriptional activity of Wnt signaling pathway.

Global prevalence and factors associated with preoperative depression in women undergoing breast surgery: a meta-analysis and meta-regression.

PURPOSE: Depression is one of the main psychological responses experienced by patients with breast cancer perioperatively. Therefore, this review aimed to synthesize the prevalence rate of depression preoperatively among patients with breast cancer. METHODS: Six databases were searched for published articles, which recruited female patients aged 18 years and above, diagnosed with breast cancer and planned for breast surgery. Grey literatures were searched from ProQuest Theses and Dissertations, Science.gov and CogPrints. Studies published in English from the inception of databases to January 2023 were considered. Two reviewers screened, extracted, and appraised the data independently. Joanna Briggs Institute data collection form was used for data collection. Hoy's Risk of Bias Tool was utilized to assess the individual study's quality. Review Manager 5.4 software was utilized for meta-analysis. Subgroup analyses were conducted to explore the reasons for any heterogeneity. Publication bias was evaluated by Egger's test and funnel plot. RESULTS: Twenty studies involving 32,143 patients with breast cancer were included. Meta-analyses revealed an overall preoperative prevalence of 30% among all studies. Subgroup analyses showed that studies conducted in the Middle East and North Africa used purposive sampling, with patients undergoing mastectomy and lumpectomy and with moderate risk of bias reported higher prevalence of preoperative depression (54%, 44%, 40%, and 49%, respectively) as compared to other respective subgroups. CONCLUSION: The high prevalence of preoperative depression among women with breast cancer indicated the need for health care professionals to provide more psychological support to them.

Protective effects of curcumin on corneal endothelial cell PANoptosis and monocyte adhesion induced by tumor necrosis factor-alpha and interferon-gamma in rats.

Decrease of human corneal endothelial cell (CEC) density leads to corneal edema, progressive corneal opacity, and reduced visual acuity. A reduction in CEC density may be related to elevated levels of inflammatory cytokines, such as tumor necrosis factor (TNF)-α and interferon (INF)-γ. PANoptosis, characterized by the activation of apoptosis, necroptosis, and pyroptosis, could be a factor in the loss of CECs driven by TNF-α and INF-γ. Cytokines also stimulate monocytes adhesion to endothelium. It has been shown in previous research that curcumin plays protective roles against numerous corneal inflammatory diseases. However, it is not determined whether curcumin acts as an anti-PANoptotic agent or if it mitigates monocyte adhesion to CECs. Therefore, this research aimed to explor the potential therapeutic effects of curcumin and its underlying mechanisms in the loss of CECs. CEC injury models were established, and curcumin was injected subconjunctivally. Clinical evaluation of the corneas was conducted using a scoring system and anterior segment photography. Corneal observation was performed with hematoxylin and eosin staining and immunostaining of zona occludens-1(ZO-1). Apoptotic cells within the corneal endothelium were observed using TUNEL staining. The detection of primary proteins expression was accomplished through Western blot analysis. Interleukin (IL)-1ß and macrophage chemotactic protein 1 (MCP-1) levels were determined via ELISA, while the expression of cleaved caspase-3, gasdermin-D (GSDMD), phosphor-mixed lineage kinase domain-like protein (p-MLKL) and intercellular cell adhesion molecule-1 were confirmed by immunofluorescence. Myeloperoxidase (MPO) activity was measured in aqueous humors. Curcumin treatment attenuated the loss of CECs and corneal edema caused by TNF-α and IFN-γ. Besides, it decreased the count of TUNEL-positive cells, and inhibited the upregulation of cleaved caspase-3, cleaved caspase-6, cleaved caspase-7, and cleaved poly (ADP-ribose) polymerase. Moreover, both the expression and phosphorylation of MLKL and receptor-interacting protein 3 were decreased in curcumin-treated rats. Furthermore, curcumin also lowered the expression of cleaved caspase-1, diminished the levels of IL1ß and MCP-1, and inhibited the activity of MPO. Besides, the expression of intercellular cell adhesion molecule-1, vascular cell adhesion molecule-1, as well as the number of CD11b-positive cells adhered to the CECs decreased for the administration of curcumin.

The Ceiling Effects of EQ-5D-3L and 5L in General Population Health Surveys: A Systematic Review and Meta-Analysis.

OBJECTIVES: This review aims to examine the ceiling effects of EQ-5D-3L (3L) and EQ-5D-5L (5L) in general adult populations and identify the factors influencing these effects. METHODS: We searched 8 databases for observational studies published in English from inception to 24 July 2023. Ceiling effects were calculated by dividing the number of participants reporting full health at dimension or profile level by the total sample size. Subgroup analysis and meta-regression using the metafor package in R software were performed. RESULTS: We identified 94 studies from 70 articles, including 4 543 647 adults across 37 countries. The global pooled proportion of individuals reporting full health ("11111") was 56% (95% CI 51%-62%) for 3L and 49% (95% CI 44%-54%) for 5L. The self-care dimension showed the highest ceiling effects (3L: 97%; 5L: 94%), whereas pain/discomfort had the lowest (3L: 69%; 5L: 60%). The ceiling effects in East/South-East Asia were higher than in Europe by 25% (95% CI 18%-32%) in 3L and 9% (95% CI -2%-20%) in 5L. Adjusting for mean age and proportion of males, significant regional differences persisted in the overall profile level of 3L, in all 3L dimensions (except for self-care), and 5L dimensions (except for pain/discomfort and anxiety/depression). CONCLUSIONS: This review highlights significant ceiling effects in the EQ-5D, especially in Asian populations. The 5L version exhibited fewer ceiling effects than the 3L, indicating its superiority for general population surveys. Further research is crucial to understand the disparities in self-reported health outcomes between Asians and other populations.

The impact of laparoscopic radical gastrectomy on the inflammatory response and immune function of patients with gastric cancer.

The currest study aimed to measure the effects of laparoscopic radical gastrectomy on inflammatory response along with immune function in gastric cancer (GC) patients. Seventy patients with GC in our hospital were retrospectively chosen to be the study objects and separated into control group (CG, 35 cases) and observation group (OG, 35 cases). Patients in the OG received radical laparotomy. Patients in the OG received laparoscopic radical gastrectomy. The surgical indicators, postoperative recovery indicators, inflammatory factors, immune function, incidence of adverse reactions along with quality of life of patients in both groups were compared. In contrast to the CG, the operation time of the OG presented as shorter (P<0.05), and the amount of intraoperative blood loss together with postoperative VAS score in the OG presented lower (P<0.05), but the number of lymph nodes dissection presented not statistically significant between 2 groups (P>0.05). The postoperative exhaust time, feeding time as well as hospital stay in the OG presented shorter relative to the CG (P<0.05). The serum levels of CRP, and IL-6 together with TNF-α presented elevated in both groups after surgery, and those in the OG presented lower when compared with the CG (P<0.05). The serum levels of IgA, and IgG together with IgM presented declined in both groups after surgery, and those in the OG presented higher when compared with the CG (P<0.05). The incidence of postoperative complications in the OG presented reduction relative to the CG (P<0.05). The GLQI scores of the OG presented significantly higher relative to the CG at discharge (P<0.05). Compared with radical gastrectomy, laparoscopic radical gastrectomy is more suitable for the treatment of GC, which can reduce the inflammatory response and promote the immune function of GC patients.

Pygo2 activates BRPF1 via Pygo2-H3K4me2/3 interaction to maintain malignant progression in colon cancer.

Epigenetic alterations have essential roles during colon adenocarcinoma (COAD) progression. As the coactivator of Wnt/b-catenin signaling, Pygopus 2 (Pygo2) binds H3K4me2/3 and participate in chromatin remodeling in multiple cancers. However, It remains unclear whether the Pygo2-H3K4me2/3 association has significance in COAD. We aimed to elucidate the roles of Pygo2 in COAD. Functionally, Pygo2 inhibition attenuated cell proliferation, self-renewal capacities in vitro. Pygo2 overexpression enhanced in vivo tumor growth. Besides, Pygo2 overexpression could also enhance cell migration ability and in vivo distal metastasis. Mechanistically, Pygo2 correlates positively with BRPF1 expressions, one epigenetic reader of histone acetylation. The luciferase reporter assay and Chromatin Immunoprecipitation (ChIP)-qPCR assay were used to find that Pygo2 coordinated with H3K4me2/3 modifications to activate BRPF1 transcriptions via binding to the promoter. Both Pygo2 and BRPF1 expressed highly in tumors and Pygo2 relied on BRPF1 to accelerate COAD progression, including cell proliferation rate, migration abilities, stemness features and in vivo tumor growth. Targeting BPRF1 (GSK5959) is effective to suppress in vitro growth of Pygo2high cell lines, and has mild effect on Pygo2low cells. The subcutaneous tumor model further demonstrated that GSK5959 could effectively suppress the in vivo growth of Pygo2high COAD, but not the Pygo2low subtype. Collectively, our study represented Pygo2/BRPF1 as an epigenetic vulnerability for COAD treatment with predictive significance.

Novel sulfonyl-substituted tetrandrine derivatives for colon cancer treatment by inducing mitochondrial apoptosis and inhibiting PI3K/AKT/mTOR pathway.

Tetrandrine (TET) possesses multiple pharmacological activities and could suppress tumor proliferation via PI3K pathway inhibition. However, inferior antitumor activity and potential toxicity limit its clinical application. In the present study, a series of 14-sulfonamide and sulfonate TET derivatives were designed, synthesized, and evaluated for biological activities. Through structural-activity relationship studies, compound 3c with α, ß-unsaturated carbonyl group exhibited the most potent activity against all tested tumor cell lines (including Hela, HCT116, HepG2, MCF-7, and SHSY5Y), as well as negligible toxicity against normal cell lines LO2 and HEK293. Additionally, compound 3c effectively inhibited HCT116 and CT26 cell proliferation in vitro with increased cell proportion in the G2/M phase, activated the mitochondrial apoptosis pathway, and induced colon cancer cell apoptosis by suppressing the PI3K/AKT/mTOR pathway. The further molecular docking results confirmed that compound 3c is potentially bound to multiple residues in PI3K with a stronger binding affinity than TET. Ultimately, compound 3c dramatically suppressed tumor growth in the CT26 xenograft tumor model, without noticeable visceral toxicity detected in the high-dose group. In summary, compound 3c might present new insights for designing new PI3K inhibitors and be a potential candidate for colon cancer treatment.

Association of a healthy ageing index with health-related outcomes in a multi-ethnic cohort from Singapore.

BACKGROUND: The global population is ageing rapidly and it is important to promote healthy ageing. The Healthy Ageing Index (HAI) is a comprehensive measure of health, but there is limited research on its association with other age-related outcomes. The management of an aging population necessitates considerations even among generally healthy adults, as age-related diseases often remain unaccounted for until later stages of life. This study explores the association of risk factors with HAI and its association with peripheral artery disease (PAD), muscle strength, health-related quality of life (HRQoL), and psychological distress in the Singapore Multi-Ethnic Cohort study. METHODS: This cross-sectional study involved 1909 participants (median (Q1, Q3) age: 53 (48, 60) years and 59.3% females) from Singapore Multi-Ethnic Cohort study. The risk factors of HAI included age, gender, ethnicity, education level, smoking, alcohol consumption, employment, BMI and past medical histories. PAD was assessed using ankle-brachial index (ABI), handgrip strength (HGS), HRQoL with the EQ-5D-5 L questionnaire and psychological distress via the Kessler Psychological Distress Scale (K10). HAI components were assessed using relevant marker tests. RESULTS: Older age, Malay and Indian ethnicities, unemployment, high BMI and histories of CHD, hypercholesterolaemia, tumours and TIA/stroke were associated with lower HAI scores indicative of poorer health. Higher HAI scores were associated with females and higher education levels. Lower HAI scores were significantly associated with low ABI, high K10 scores, mobility and anxiety/depression dimensions of EQ-5D-5 L. CONCLUSION: The most important factors associated with HAI were age, sex, ethnicity, education, unemployment, BMI and a history of health conditions. Lower HAI scores were significantly associated with PAD, lower HRQoL and psychological distress. Thus, the HAI demonstrates promise as an evaluation method for assessing PAD, overall muscle strength and HRQoL in a population-based setting.

A nonsense TMEM43 variant leads to disruption of connexin-linked function and autosomal dominant auditory neuropathy spectrum disorder.

Genes that are primarily expressed in cochlear glia-like supporting cells (GLSs) have not been clearly associated with progressive deafness. Herein, we present a deafness locus mapped to chromosome 3p25.1 and an auditory neuropathy spectrum disorder (ANSD) gene, TMEM43, mainly expressed in GLSs. We identify p.(Arg372Ter) of TMEM43 by linkage analysis and exome sequencing in two large Asian families segregating ANSD, which is characterized by inability to discriminate speech despite preserved sensitivity to sound. The knock-in mouse with the p.(Arg372Ter) variant recapitulates a progressive hearing loss with histological abnormalities in GLSs. Mechanistically, TMEM43 interacts with the Connexin26 and Connexin30 gap junction channels, disrupting the passive conductance current in GLSs in a dominant-negative fashion when the p.(Arg372Ter) variant is introduced. Based on these mechanistic insights, cochlear implant was performed on three subjects, and speech discrimination was successfully restored. Our study highlights a pathological role of cochlear GLSs by identifying a deafness gene and its causal relationship with ANSD.

Environmental Doping-Induced Degradation of the Quantum Anomalous Hall Insulators.

The quantum anomalous Hall (QAH) insulator carries dissipation-free chiral edge current and thus provides a unique opportunity to develop energy-efficient transformative information technology. Despite promising advances, the QAH insulator has thus far eluded any practical applications. In addition to its low working temperature, the QAH state in magnetically doped topological insulators usually deteriorates with time in ambient conditions. In this work, we store three QAH devices with similar initial properties in different environments. The QAH device without a protection layer in air shows clear degradation and becomes hole-doped. The QAH device kept in an argon glovebox without a protection layer shows no measurable degradation after 560 h, and the device protected by a 3 nm AlOx protection layer in air shows minimal degradation with stable QAH properties. Our work shows a route to preserve the dissipation-free chiral edge state in QAH devices for potential applications in quantum information technology.

Chemokine CCL7 mediates trigeminal neuropathic pain via CCR2/CCR3-ERK pathway in the trigeminal ganglion of mice.

BACKGROUND: Chemokine-mediated neuroinflammation plays an important role in the pathogenesis of neuropathic pain. The chemokine CC motif ligand 7 (CCL7) and its receptor CCR2 have been reported to contribute to neuropathic pain via astrocyte-microglial interaction in the spinal cord. Whether CCL7 in the trigeminal ganglion (TG) involves in trigeminal neuropathic pain and the involved mechanism remain largely unknown. METHODS: The partial infraorbital nerve transection (pIONT) was used to induce trigeminal neuropathic pain in mice. The expression of Ccl7, Ccr1, Ccr2, and Ccr3 was examined by real-time quantitative polymerase chain reaction. The distribution of CCL7, CCR2, and CCR3 was detected by immunofluorescence double-staining. The activation of extracellular signal-regulated kinase (ERK) was examined by Western blot and immunofluorescence. The effect of CCL7 on neuronal excitability was tested by whole-cell patch clamp recording. The effect of selective antagonists for CCR1, CCR2, and CCR3 on pain hypersensitivity was checked by behavioral testing. RESULTS: Ccl7 was persistently increased in neurons of TG after pIONT, and specific inhibition of CCL7 in the TG effectively relieved pIONT-induced orofacial mechanical allodynia. Intra-TG injection of recombinant CCL7 induced mechanical allodynia and increased the phosphorylation of ERK in the TG. Incubation of CCL7 with TG neurons also dose-dependently enhanced the neuronal excitability. Furthermore, pIONT increased the expression of CCL7 receptors Ccr1, Ccr2, and Ccr3. The intra-TG injection of the specific antagonist of CCR2 or CCR3 but not of CCR1 alleviated pIONT-induced orofacial mechanical allodynia and reduced ERK activation. Immunostaining showed that CCR2 and CCR3 are expressed in TG neurons, and CCL7-induced hyperexcitability of TG neurons was decreased by antagonists of CCR2 or CCR3. CONCLUSION: CCL7 activates ERK in TG neurons via CCR2 and CCR3 to enhance neuronal excitability, which contributes to the maintenance of trigeminal neuropathic pain. CCL7-CCR2/CCR3-ERK pathway may be potential targets for treating trigeminal neuropathic pain.

Crossover from Ising- to Rashba-type superconductivity in epitaxial Bi2Se3/monolayer NbSe2 heterostructures.

A topological insulator (TI) interfaced with an s-wave superconductor has been predicted to host topological superconductivity. Although the growth of epitaxial TI films on s-wave superconductors has been achieved by molecular-beam epitaxy, it remains an outstanding challenge for synthesizing atomically thin TI/superconductor heterostructures, which are critical for engineering the topological superconducting phase. Here we used molecular-beam epitaxy to grow Bi2Se3 films with a controlled thickness on monolayer NbSe2 and performed in situ angle-resolved photoemission spectroscopy and ex situ magnetotransport measurements on these heterostructures. We found that the emergence of Rashba-type bulk quantum-well bands and spin-non-degenerate surface states coincides with a marked suppression of the in-plane upper critical magnetic field of the superconductivity in Bi2Se3/monolayer NbSe2 heterostructures. This is a signature of a crossover from Ising- to Rashba-type superconducting pairings, induced by altering the Bi2Se3 film thickness. Our work opens a route for exploring a robust topological superconducting phase in TI/Ising superconductor heterostructures.

Experimental realization of free-space continuous-variable quantum key distribution based on fiber Sagnac interferometer.

The Gaussian-modulated coherent state (GMCS) is a well-known continuous-variable quantum key distribution (CV-QKD) protocol that is robust to incoherent background noise and can effectively suppress ambient light in free space. However, it is difficult to implement this protocol in free space using existing polarization coding schemes. In this Letter, we propose a polarization coding structure based on a self-compensating fiber Sagnac interferometer, which can reduce the required modulation voltage by two orders of magnitude and achieve fast and arbitrary polarization modulation, and experimentally demonstrate polarization coding-based GMCS CV-QKD for, it is believed, the first time. The proposed polarization modulation structure, which uses off-the-shelf fiber components, is compact, simple, and suitable for mobile terminals, such as flying lifts.

Confinement-Induced Chiral Edge Channel Interaction in Quantum Anomalous Hall Insulators.

In quantum anomalous Hall (QAH) insulators, the interior is insulating but electrons can travel with zero resistance along one-dimensional (1D) conducting paths known as chiral edge channels (CECs). These CECs have been predicted to be confined to the 1D edges and exponentially decay in the two-dimensional (2D) bulk. In this Letter, we present the results of a systematic study of QAH devices fashioned in a Hall bar geometry of different widths under gate voltages. At the charge neutral point, the QAH effect persists in a Hall bar device with a width of only ∼72 nm, implying the intrinsic decaying length of CECs is less than ∼36 nm. In the electron-doped regime, we find that the Hall resistance deviates quickly from the quantized value when the sample width is less than 1 µm. Our theoretical calculations suggest that the wave function of CEC first decays exponentially and then shows a long tail due to disorder-induced bulk states. Therefore, the deviation from the quantized Hall resistance in narrow QAH samples originates from the interaction between two opposite CECs mediated by disorder-induced bulk states in QAH insulators, consistent with our experimental observations.

Paenibacillus mangrovi sp. nov., a novel endophytic bacterium isolated from bark of Kandelia candel.

A endospore-forming bacterium, designated strain KQZ6P-2T, was isolated from surface-sterilized bark of the mangrove plant Kandelia candel, collected from Maowei Sea Mangrove Nature Reserve in Guangxi Zhuang Autonomous Region, China. Strain KQZ6P-2T was able to grow at NaCl concentrations in the range of 0-3 % (w/v) with optimum growth at 0-1 % (w/v) NaCl. Growth occurred at 20-42 °C (optimal growth at 30-37 °C) and pH 5.5-6.5 (optimal growth at pH 6.5). The 16S rRNA gene sequence similarity between strain KQZ6P-2T and its closest phylogenetic neighbour Paenibacillus chibensis JCM 9905T was 98.2 %. Phylogenetic analyses using 16S rRNA gene sequences showed that strain KQZ6P-2T formed a distinct lineage with Paenibacillus chibensis JCM 9905T. The draft genome of strain KQZ6P-2T was 5 937 633 bp in size and its DNA G+C content was 47.2mol%. Comparative genome analysis revealed that the average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values among strain KQZ6P-2T and its related species were below the cut-off levels of 95, 70 and 95.5%, respec-tively. The cell-wall peptidoglycan of strain KQZ6P-2T contained meso-diaminopimelic acid as the diagnostic diamino acid. Major cellular fatty acids were anteiso-C15:0 and C16:0. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified aminophospholipids, four unidentified phospholipids, an unidentified aminolipid and five unidentified lipids. Based on phylogenetic, phenotypic and chemotaxonomic data, strain KQZ6P-2T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus mangrovi sp. nov. is proposed. The type strain is KQZ6P-2T (=MCCC 1K07172T =JCM 34931T).