Functional Renormalization Group Study of Superconductivity in Rhombohedral Trilayer Graphene.

We employ a functional renormalization group approach to ascertain the pairing mechanism and symmetry of the superconducting phase observed in rhombohedral trilayer graphene. Superconductivity in this system occurs in a regime of carrier density and displacement field with a weakly distorted annular Fermi sea. We find that repulsive Coulomb interactions can induce electron pairing on the Fermi surface by taking advantage of momentum-space structure associated with the finite width of the Fermi sea annulus. The degeneracy between spin-singlet and spin-triplet pairing is lifted by valley-exchange interactions that strengthen under the RG flow and develop nontrivial momentum-space structure. We find that the leading pairing instability is d-wave-like and spin singlet, and that the theoretical phase diagram versus carrier density and displacement field agrees qualitatively with experiment.

Pseudospin Paramagnons and the Superconducting Dome in Magic Angle Twisted Bilayer Graphene.

We present a theory of superconductivity in twisted bilayer graphene in which attraction is generated between electrons on the same honeycomb sublattice when the system is close to a sublattice polarization instability. The resulting Cooper pairs are spin-polarized valley singlets. Because the sublattice polarizability is mainly contributed by interband fluctuations, superconductivity occurs over a wide range of filling fraction. It is suppressed by (i) applying a sublattice polarizing field (generated by an aligned BN substrate) or (ii) changing moiré band filling to favor valley polarization. The enhanced intrasublattice attraction close to sublattice polarization instability is analogous to enhanced like-spin attraction in liquid ^{3}He near the melting curve and the enhanced valley-singlet repulsion close to valley-polarization instabilities is analogous to enhanced spin-singlet repulsion in metals that are close to a ferromagnetic instability. We comment on the relationship between our pseudospin paramagnon model and the rich phenomenology of superconductivity in twisted bilayer and multilayer graphene.

Identification of the Immune Cell Infiltration Landscape in Head and Neck Squamous Cell Carcinoma (HNSC) for the Exploration of Immunotherapy and Prognosis.

It is generally believed that the majority of head and neck cancers develop in the mucosal epithelial cells of the mouth, pharynx, and larynx, which is collectively known as head and neck squamous cell carcinoma (HNSC). As a complex pathological process, HNSC develops through a variety of cellular and molecular events. Cancerous cells and immune cells infiltrating tumors are the main components of the tumor microenvironment. However, infiltration of HNSCs by the immune system has not been determined to date. In this work, we proposed computational algorithms to identify different immune subtypes. An analysis of the Cancer Genome Atlas (TCGA) database revealed gene expression profiles and corresponding clinical information. In HNSC patients, two immune-related genes (ZAP70 and IGKV2D-40) may be targets for immunotherapy, and these genes appear to be closely related to the prognosis. Several immunological subtypes were associated with immune function, immune checkpoints, and prognostic factors in HNSCs. Furthermore, ZAP70 is closely related to the overall survival (OS), progress-free interval (PFI), and disease-specific survival (DSS) of HNSC patients. The potential pathways that are associated with ZAP70 were found to have included adaptive immune response, response to oxidative stress, DNA replication, and lipid binding. This study provides a theoretical foundation for developing immunotherapy drugs for HNSC patients. By evaluating larger cohorts, we can gain a deeper understanding of immunotherapy and provide direction for current research on immunotherapy strategies in HNSCs.

Comprehensive characterization and optimization of Caco-2 cells enabled the development of a miniaturized 96-well permeability assay.

Assessment of compound permeability through a Caco-2 cell monolayer is a well-accepted model to evaluate its in-vivo permeability potential and transporter interaction. While this assay has commonly been conducted using a 24-well assay plate format, a miniaturised 96-well assay format is highly desirable to achieve greater capacity and higher efficiency.Previous attempts to convert this assay from 24-well to 96-well format at our lab, however, had met with varied efflux capacities and unacceptable efflux ratios for digoxin, a substrate of P-glycoprotein (Pgp), which indicated inadequate Pgp transporter expression in the 96-well format.These challenges in converting the assays were attributed to the heterogeneous and unstable nature of the Caco-2 cells. To overcome the challenges, single-cell sorting of Caco-2 cells was conducted by flow cytometry to obtain a more homogeneous and stable cell population. The sorted cells were then seeded to 96-well transwell plates and the Pgp expression under various cell culture conditions was monitored by a LC-MS/MS-based targeted proteomics method.Through cell sorting and direct Pgp expression measurement, Caco-2 cells with adequate and sustained Pgp expression in a 96-well format were obtained, which led to the successful development and implementation of a 96-well Caco-2 assay with significant efficiency gain and faster turnaround time than the historical 24-well assay.

Enhancement of Spin-Charge Conversion in Dilute Magnetic Alloys by Kondo Screening.

We derive a kinetic theory capable of dealing both with large spin-orbit coupling and Kondo screening in dilute magnetic alloys. We obtain the collision integral nonperturbatively and uncover a contribution proportional to the momentum derivative of the impurity scattering S matrix. The latter yields an important correction to the spin diffusion and spin-charge conversion coefficients, and fully captures the so-called side-jump process without resorting to the Born approximation (which fails for resonant scattering), or to otherwise heuristic derivations. We apply our kinetic theory to a quantum impurity model with strong spin-orbit, which captures the most important features of Kondo-screened Cerium impurities in alloys such as Ce_{x}La_{1-x}Cu_{6}. We find (1) a large zero-temperature spin-Hall conductivity that depends solely on the Fermi wave number and (2) a transverse spin diffusion mechanism that modifies the standard Fick's diffusion law. Our predictions can be readily verified by standard spin-transport measurements in metal alloys with Kondo impurities.

Scattering of Magnons at Graphene Quantum-Hall-Magnet Junctions.

Motivated by recent nonlocal transport studies of quantum-Hall-magnet (QHM) states formed in monolayer graphene's N=0 Landau level, we study the scattering of QHM magnons by gate-controlled junctions between states with different integer filling factors ν. For the ν=1|-1|1 geometry we find that magnons are weakly scattered by electric potential variation in the junction region, and that the scattering is chiral when the junction lacks a mirror symmetry. For the ν=1|0|1 geometry, we find that kinematic constraints completely block magnon transmission if the incident angle exceeds a critical value. Our results explain the suppressed nonlocal-voltage signals observed in the ν=1|0|1 case. We use our theory to propose that valley waves generated at ν=-1|1 junctions and magnons can be used in combination to probe the spin or valley flavor structure of QHM states at integer and fractional filling factors.

Current-Driven Magnetization Reversal in Orbital Chern Insulators.

Graphene multilayers with flat moiré minibands can exhibit the quantized anomalous Hall effect due to the combined influence of spontaneous valley polarization and topologically nontrivial valley-projected bands. The sign of the Hall effect in these Chern insulators can be reversed either by applying an external magnetic field, or by driving a transport current through the system. We propose a current-driven mechanism whereby reversal occurs along lines in the (current I, magnetic-field B) control parameter space with slope dI/dB=(e/h)MA_{M}(1-γ^{2})/γ, where M is the magnetization, A_{M} is the moiré unit cell area, and γ<1 is the ratio of the chemical potential difference between valleys along a domain wall to the electrical bias eV.

Spatially Discordant Repolarization Alternans in the Absence of Conduction Velocity Restitution.

Spatially discordant alternans (SDA) of action potential duration (APD) has been widely observed in cardiac tissue and is linked to cardiac arrhythmogenesis. Theoretical studies have shown that conduction velocity restitution (CVR) is required for the formation of SDA. However, this theory is not completely supported by experiments, indicating that other mechanisms may exist. In this study, we carried out computer simulations using mathematical models of action potentials to investigate the mechanisms of SDA in cardiac tissue. We show that when CVR is present and engaged, such as fast pacing from one side of the tissue, the spatial pattern of APD in the tissue undergoes either spatially concordant alternans or SDA, independent of initial conditions or tissue heterogeneities. When CVR is not engaged, such as simultaneous pacing of the whole tissue or under normal/slow heart rates, the spatial pattern of APD in the tissue can have multiple solutions, including spatially concordant alternans and different SDA patterns, depending on heterogeneous initial conditions or pre-existing repolarization heterogeneities. In homogeneous tissue, curved nodal lines are not stable, which either evolve into straight lines or disappear. However, in heterogeneous itssue, curved nodal lines can be stable, depending on their initial locations and shapes relative to the structure of the heterogeneity. Therefore, CVR-induced SDA and non-CVR-induced SDA exhibit different dynamical properties, which may be responsible for the different SDA properties observed in experimental studies and arrhythmogenesis in different clinical settings.

Serum exosomal miR-7977 as a novel biomarker for lung adenocarcinoma.

Exosomal microRNAs (miRNAs) have great potentials as a novel biomarker to predict lung cancer. We applied a miRNA microarray to identify aberrantly expressed serum exosomal miRNAs as candidate biomarkers for patients with lung adenocarcinoma (LUAD). Compared with the normal control, 31 exosomal miRNAs were found to be upregulated and 29 exosomal miRNAs were downregulated in the serum of LUAD respectively. Then, 10 dysregulated exosomal miRNAs expression levels in serum were further validated via qRT-polymerase chain reaction. Notably, exosomal miR-7977 was highest expressed and miR-98-3p was lowest expressed in the patients with LUAD, and exosomal miR-7977 showed significant correlation with the N stage and TNM stage with patients with LUAD (P < .05). Receiver operating characteristic curve showed that the abundant level of exosomal miR-7977 may predict LUAD with an area of under the curve (AUC) of 0.787. In comparison with exosomal miR-7977, exosomal miR-98-3p had a smaller area (0.719). The combination of exosomal miR-7977 and miR-98-3p improved the AUC to 0.816. Furthermore, in vitro experiments revealed that inhibition of miR-7977 enhanced the proliferation, invasion, and inhibited apoptosis in A549 cells, the opposite results were performed by miR-7977 mimics. In conclusion, exosomal miR-7977 was identified as a novel biomarker for patients with LUAD and may play as a tumor suppressor in lung cancer.

Circular RNAs expression profiles in plasma exosomes from early-stage lung adenocarcinoma and the potential biomarkers.

This study aimed to identify differential circular RNA (circRNA) in the plasma exosomes of patients with lung adenocarcinoma (LUAD) using high-throughput sequencing. First, exosomes were isolated using an exosome isolation kit and confirmed by Western blotting, transmission electron microscopy, and NanoSight Assay. Subsequently, plasma circRNA expression profiles were screened by high-throughput sequencing and confirmed by fluorescence quantitative real-time polymerase chain reaction (qRT-PCR) and Sanger sequencing. Finally, the circRNA-miRNA-mRNA network was performed to forecast the potential function of circRNAs. The result of high-throughput sequencing data documented that 182 differentially expressed exosomal circRNAs in all were screened, which included 105 that were upregulated and 78 that were downregulated in LUAD patients plasma compared with controls. The four upregulated circRNAs including circ_0001492, circ_0001346, circ_0000690, and circ_0001439 were identical to the sequencing data by qRT-PCR, and their latent circRNA-miRNA-mRNA interactions were exhibited. Taken together, our study firstly revealed the altered exosomal circRNA expression from plasma samples in patients with LUAD and supports the need for exploring their potential as biomarkers and the pathological effects of lung cancer.

Proposal for Unambiguous Electrical Detection of Spin-Charge Conversion in Lateral Spin Valves.

Efficient detection of spin-charge conversion is crucial for advancing our understanding of emergent phenomena in spin-orbit-coupled nanostructures. Here, we provide a proof of principle of an electrical detection scheme of spin-charge conversion that enables full disentanglement of competing spin-orbit coupling (SOC) transport phenomena in diffusive lateral channels, i.e., the inverse spin Hall effect and the spin galvanic effect. A suitable geometry in an applied oblique magnetic field is shown to provide direct access to SOC transport coefficients through a symmetry analysis of the output nonlocal resistance. The scheme is robust against tilting of the spin-injector magnetization, disorder, and spurious non-spin-related contributions to the nonlocal signal and can be used to probe spin-charge conversion effects in both spin-valve and hybrid optospintronic devices.

Stability of spatially discordant repolarization alternans in cardiac tissue.

Cardiac alternans, a period-2 behavior of excitation and contraction of the heart, is a precursor of ventricular arrhythmias and sudden cardiac death. One form of alternans is repolarization or action potential duration alternans. In cardiac tissue, repolarization alternans can be spatially in-phase, called spatially concordant alternans, or spatially out-of-phase, called spatially discordant alternans (SDA). In SDA, the border between two out-of-phase regions is called a node in a one-dimensional cable or a nodal line in a two-dimensional tissue. In this study, we investigate the stability and dynamics of the nodes and nodal lines of repolarization alternans driven by voltage instabilities. We use amplitude equation and coupled map lattice models to derive theoretical results, which are compared with simulation results from the ionic model. Both conduction velocity restitution induced SDA and non-conduction velocity restitution induced SDA are investigated. We show that the stability and dynamics of the SDA nodes or nodal lines are determined by the balance of the tensions generated by conduction velocity restitution, convection due to action potential propagation, curvature of the nodal lines, and repolarization and coupling heterogeneities. Our study provides mechanistic insights into the different SDA behaviors observed in experiments.

Evidence of peripheral olfactory impairment in the domestic silkworms: insight from the comparative transcriptome and population genetics.

BACKGROUND: The insect olfactory system is a highly specific and sensitive chemical detector, which plays important roles in feeding, mating and finding an appropriate oviposition site. The ecological niche of Bombyx mori has changed greatly since domestication from B. mandarina, and its olfactory response to environmental odorants clearly decreased. However, the mechanisms that result in the olfactory impairment are largely unknown. RESULTS: The antennal transcriptomes were compared between the domestic and wild silkworms. Comparison of the same sex between the domestic and wild silkworms revealed 1410 and 1173 differentially expressed genes (DEGs) in males and females, respectively. To understand the olfactory impairment, we mainly focused on the olfactory-related genes. In total, 30 olfactory genes and 19 odorant-degrading enzymes (ODEs) showed differential expression in the two comparisons, in which 19 and 14 were down-regulated in the domestic silkworm, respectively. Based on population genomic data, the down-regulated odorant receptors (ORs) showed a higher ratio of unique non-synonymous polymorphisms to synonymous polymorphisms (N/S ratio) in the domestic populations than that in the wild silkworms. Furthermore, one deleterious mutation was found in OR30 of the domestic population, which was located in transmembrane helix 6 (TM6). CONCLUSIONS: Our results suggested that down-regulation of the olfactory-related genes and relaxed selection might be the major reasons for olfactory impairment of the domestic silkworm reared completely indoor environment. Reversely, wild silkworm may increase expression and remove deleterious polymorphisms of olfactory-related genes to retain sensitive olfaction.

Anomalous Nonlocal Resistance and Spin-Charge Conversion Mechanisms in Two-Dimensional Metals.

We uncover two anomalous features in the nonlocal transport behavior of two-dimensional metallic materials with spin-orbit coupling. First, the nonlocal resistance can have negative values and oscillate with distance, even in the absence of a magnetic field. Second, the oscillations of the nonlocal resistance under an applied in-plane magnetic field (the Hanle effect) can be asymmetric under field reversal. Both features are produced by direct magnetoelectric coupling, which is possible in materials with broken inversion symmetry but was not included in previous spin-diffusion theories of nonlocal transport. These effects can be used to identify the relative contributions of different spin-charge conversion mechanisms. They should be observable in adatom-functionalized graphene, and they may provide the reason for discrepancies in recent nonlocal transport experiments on graphene.

Edge Modes, Degeneracies, and Topological Numbers in Non-Hermitian Systems.

We analyze chiral topological edge modes in a non-Hermitian variant of the 2D Dirac equation. Such modes appear at interfaces between media with different "masses" and/or signs of the "non-Hermitian charge." The existence of these edge modes is intimately related to exceptional points of the bulk Hamiltonians, i.e., degeneracies in the bulk spectra of the media. We find that the topological edge modes can be divided into three families ("Hermitian-like," "non-Hermitian," and "mixed"); these are characterized by two winding numbers, describing two distinct kinds of half-integer charges carried by the exceptional points. We show that all the above types of topological edge modes can be realized in honeycomb lattices of ring resonators with asymmetric or gain-loss couplings.

Significance of Anthropogenic Factors to Freely Dissolved Polycyclic Aromatic Hydrocarbons in Freshwater of China.

Assessment of surface water pollution by organic pollutants is a top priority in many parts of the world, as it provides critical information for implementing effective measures to ensure drinking water safety. This is particularly important in China, where insufficient data of national scale have been acquired on the occurrence of any organic pollutants in the country's water bodies. To fill the knowledge gap, we employed passive samplers to survey polycyclic aromatic hydrocarbons (PAHs) in 42 freshwaters throughout the country. The dissolved Σ24PAH concentrations ranged from 0.28 to 538 ng L-1, with the highest and lowest values obtained in Southern Lake in Wuhan and in the Nam Co Lake in Tibet, respectively. Average Σ24PAH concentrations in West, Central, and East China correlated well with the population densities in these regions. The composition profiles of PAHs showed a mixed PAH source of coal combustion, fossil fuel combustion, and oil spills. In addition, all dissolved PAH concentrations were below the water guidelines developed by the U.S. Environmental Protection Agency, the European Union, and the Canadian government, except for anthracene in Southern Lake. Our results also demonstrated the feasibility of establishing a global network of monitoring organic pollutants in the aquatic environment with passive sampling techniques.

Velocity synchronization of multi-agent systems with mismatched parameters via sampled position data.

Power systems are special multi-agent systems with nonlinear coupling function and symmetric structures. This paper extends these systems to a class of multi-agent systems with mismatched parameters, linear coupling function, and asymmetric structures and investigates their velocity synchronization via sampled position data. The dynamics of the agents is adopted as that of generators with mismatched parameters, while the system structures are supposed to be complex. Two distributed linear consensus protocols are designed, respectively, for multi-agent systems without or with communication delay. Necessary and sufficient conditions based on the sampling period, the mismatched parameters, the delay, and the nonzero eigenvalues of the Laplacian matrix are established. It is shown that velocity synchronization of multi-agent systems with mismatched parameters can be achieved if the sampled period is chosen appropriately. Simulations are given to illustrate the effectiveness of the theoretical results.

The value of metagenomic next-generation sequencing for the diagnosis of pulmonary tuberculosis using bronchoalveolar lavage fluid.

OBJECTIVE: The aim of this study was to compare metagenomic next-generation sequencing (mNGS) with other methods, including Xpert MTB/RIF, Mycobacterium tuberculosis (MTB) culture, and acid-fast bacillus (AFB) staining in the diagnosis of pulmonary tuberculosis (PTB) using bronchoalveolar lavage fluid (BALF). METHODS: The data of 186 patients with suspected PTB were retrospectively collected from January 2020 to May 2021 at Tongji Hospital. BALF samples were collected from all patients and analyzed using AFB staining, MTB culture, Xpert MTB/RIF, and mNGS. RESULTS: Of the 186 patients, 38 patients were ultimately diagnosed as PTB. Metagenomic next-generation sequencing exhibited a sensitivity of 78.95%, which was higher than AFB staining (27.59%) and MTB culture (44.12%) but similar to Xpert MTB/RIF (72.73%). Utilization of combined methods demonstrates improvement for PTB diagnosis. In support of this, the area under the receiver operating characteristic curve for the combination of mNGS and MTB culture (0.933, 95% CI: 0.871, 0.995) was larger than those of mNGS, Xpert MTB/RIF, MTB culture, and the combination of Xpert MTB/RIF and MTB culture. CONCLUSION: The sensitivity of mNGS in the diagnosis of PTB using BALF specimen is similar to Xpert MTB/RIF. Metagenomic next-generation sequencing in combination with MTB culture may further improve the diagnosis of pulmonary tuberculosis.

Efficacy and safety of modified Valsalva maneuver for treatment of paroxysmal supraventricular tachycardia: a meta-analysis.

OBJECTIVE: To compare the efficacy and safety of the modified versus standard Valsalva maneuver in the treatment of paroxysmal supraventricular tachycardia (PSVT). METHODS: The PubMed, Embase, Web of Science, CNKI, WanFang Data, and VIP electronic databases were searched to identify studies comparing the modified and standard Valsalva maneuvers in the treatment of PSVT from database inception to 1 May 2023. Two reviewers independently screened the literature, extracted the data, and assessed the risk of bias of all included studies. RESULTS: Nineteen randomized controlled trials involving 2527 patients with PSVT were included. The overall rate of cardioversion was higher in the modified than standard Valsalva group (risk ratio [RR] = 1.80, 95% confidence interval [CI] = 1.61-2.01), as was the success rate of cardioversion after a single Valsalva maneuver (RR = 2.05, 95% CI = 1.74-2.41). There was no statistically significant difference in adverse reactions between the two groups (RR = 1.07, 95% CI = 0.82-1.38). CONCLUSION: Current evidence suggests that the modified Valsalva maneuver can significantly improve the success rate of cardioversion in patients with PSVT without increasing adverse reactions. The modified Valsalva maneuver is therefore worth promoting and should be considered as a routine first treatment.INPLASY registration number: 2023100092.

Promiscuous Oxidosqualene Cyclases from Neoalsomitra integrifoliola Catalyzing the Formation of Tetracyclic, Pentacyclic, and Heterocyclic Triterpenes.

Six oxidosqualene cyclases (NiOSC1-NiOSC6) from Neoalsomitra integrifoliola were characterized for the biosynthesis of diverse triterpene scaffolds, including tetracyclic and pentacyclic triterpenes from the 2,3-oxidosqualene (1) and oxacyclic triterpenes from the 2,3:22,23-dioxidosqualene (2). NiOSC1 showed high efficiency in the production of naturally rare (20R)-epimers of oxacyclic triterpenes. Mutagenesis results revealed that the NiOSC1-F731G mutant significantly increased the yields of (20R)-epimers compared to the wild type. Homology modeling and molecular docking elucidated the origin of the (20R)-configuration in the epoxide addition step.