Phonon Landau Quantization and Enhanced Lifetime in Deformed Graphene.

The pseudomagnetic field effect may offer unique opportunities for the emergence of intriguing phenomena. To date, investigations into pseudomagnetic field effects on phonons have been limited to sound waves in metamaterials. The revelation of this exotic effect on the atomic vibration of natural materials remains elusive. Our simulations of twisted graphene nanoribbons reveal well-defined Landau spectra and sublattice polarization of phonon states, mimicking the behavior of Dirac Fermions in magnetic fields. Both valley-specified helical edge currents and snake orbits are obtained. Analysis of dynamics indicates that phonon Landau states have extended lifetimes, which are crucial for the realization of Landau-level lasing. Our findings demonstrate the occurrence of the phonon pseudomagnetic field effect in natural materials, which has important implications for the mechanical tuning of phonon quantum states at the atomic scale.

Giant Flexoelectricity in Bent Semiconductor Thinfilm.

We elucidate the flexoelectricity of semiconductors in the high strain gradient regime, the underlying mechanism of which is less understood. By using the generalized Bloch theorem, we uncover a strong flexoelectric-like effect in bent thinfilms of Si and Ge due to a high-strain-gradient-induced band gap closure. We show that an unusual type-II band alignment is formed between the compressed and elongated sides of the bent film. Therefore, upon the band gap closure, electrons transfer from the compressed side to the elongated side to reach the thermodynamic equilibrium, leading to a pronounced change of polarization along the film thickness dimension. The obtained transverse flexoelectric coefficients are unexpectedly high with a quadratic dependence on the film thickness. This new mechanism is extendable to other semiconductor materials with moderate energy gaps. Our findings have important implications for the future applications of flexoelectricity in semiconductor materials.

A nomogram model for predicting postoperative prognosis in patients with aneurysmal subarachnoid hemorrhage using preoperative biochemical indices.

OBJECTIVE: The nutritional status and inflammatory responses of patients with aneurysmal subarachnoid hemorrhage (aSAH) play a vital prognostic role. We investigated the relationship between preoperative prognostic nutritional index (PNI)、neutrophil/albumin ratio (NAR)、platelet/albumin ratio (PAR) and other factors and the clinical prognosis of patients who underwent clipping for aSAH and its predictive model. METHODS: The clinical data of 212 patients with aSAH who underwent neurosurgery at Nanyang Central Hospital between 2018 and 2023 were retrospectively analyzed. Based on the Glasgow Outcome Scale (GOS) score at 6 months postoperatively, the patients were categorized into two groups: poor (GOSI-III) and good (GOSIV-V) prognosis groups. Multivariate logistic regression analysis was performed to determine the predictive value of preoperative PNI、NAR、PAR、hyperlipidemia and Glasgow Coma Scale (GCS) for prognosis. Furthermore, nomograms and prognostic prediction models were constructed. Receiver operating characteristic curves and area under the curve (AUC) were utilized to determine the predictive values. RESULTS: Multivariate logistic regression analysis revealed that PNI (OR = 1.250, 95%CI 1.060 ~ 1.475, P = 0.008), NAR (OR = 0.000, 95%CI 0.000 ~ 0.004, P = 0.000), PAR(OR = 0.515, 95%CI 0.283 ~ 0.937, P = 0.030), hyperlipidemia (OR = 4.627, 95%CI 1.166 ~ 18.367, P = 0.029), and GCS(OR = 1.446, 95%CI 1.041 ~ 2.008, P = 0.028) are independent risk factors for poor postoperative prognosis. The total score of the nomogram was 200, and the AUC value was 0.972. CONCLUSIONS: PNI and NAR can reflect the nutritional status and inflammatory responses of patients.They are significantly associated with the postoperative prognosis of patients with aSAH. Comprehensively analyzing PNI and NAR combined with other clinical indicators can more effectively guide treatment and help predict prognosis.

Isoflurane preconditioning attenuates OGD/R-induced cardiomyocyte cytotoxicity by regulating the miR-210/BNIP3 axis.

Isoflurane, a commonly used inhaled anesthetic, has been found to have a cardioprotective effect. However, the precise mechanisms have not been fully elucidated. Here, we found that isoflurane preconditioning enhanced OGD/R-induced upregulation of miR-210, a hypoxia-responsive miRNA, in AC16 human myocardial cells. To further test the roles of miR-210 in regulating the effects of isoflurane preconditioning on OGD/R-induced cardiomyocyte injury, AC16 cells were transfected with anti-miR-210 or control anti-miRNA. Results showed that isoflurane preconditioning attenuated OGD/R-induced cardiomyocyte cytotoxicity (as assessed by cell viability, LDH and CK-MB levels), which could be reversed by anti-miR-210. Isoflurane preconditioning also prevented OGD/R-induced increase in apoptotic rate, caspase-3 and caspase-9 activities, and Bax level and decrease in Bcl-2 expression level, while anti-miR-210 blocked these effects. We also found that anti-miR-210 prevented the inhibitory effects of isoflurane preconditioning on OGD/R-induced decrease in adenosine triphosphate content; mitochondrial volume; citrate synthase activity; complex I, II, and IV activities; and p-DRP1 and MFN2 expression. Besides, the expression of BNIP3, a reported direct target of miR-210, was significantly decreased under hypoxia condition and could be regulated by isoflurane preconditioning. In addition, BNIP3 knockdown attenuated the effects of miR-210 silencing on the cytoprotection of isoflurane preconditioning. These findings suggested that isoflurane preconditioning exerted protective effects against OGD/R-induced cardiac cytotoxicity by regulating the miR-210/BNIP3 axis.

Morphological Awareness and DHH Students' Reading-Related Abilities: A Meta-Analysis of Correlations.

This article presents the first meta-analysis on correlations of morphological awareness (MA) with reading-related abilities in deaf and hard-of-hearing (DHH) students (k = 14, N = 556). The results showed high mean correlations of MA with all three reading-related abilities: rs = 0.610, 0.712, and 0.669 (all ps < 0.001), respectively, for word reading, vocabulary knowledge, and reading comprehension. A set of moderator analysis was conducted of language, DHH students' age/reading stage and degree of hearing loss, and task type. The correlation of MA with word reading was significantly stronger in alphabetic than in non-alphabetic languages, and for fluency than accuracy; for vocabulary knowledge, the correlation was significantly stronger for production MA tasks than for judgment tasks; for reading comprehension, derivational MA tasks showed a stronger correlation than those having a mixed focus on inflection and derivation. While no other moderator effects were significant, the correlations for subsets of effect sizes were largely high for a moderator. These findings reaffirmed the importance of morphology in DHH students' reading development. The present synthesis, while evidencing major development of research on the metalinguistic underpinnings of reading in DHH students, also showed that the literature on MA is still very limited.

Electric Field-Controlled Damping Switches of Coupled Dirac Plasmons.

For quasiparticle systems, the control of the quasiparticle lifetime is an important goal, determining whether the related fascinating physics can be revealed in fundamental research and utilized in practical applications. Here, we use double-layer graphene with a boron nitride spacer as a model system to demonstrate that the lifetime of coupled Dirac plasmons can be remotely tuned by electric field-controlled damping pathways. Essentially, one of the graphene layers serves as an external damping amplifier whose efficiency can be controlled by the corresponding doping level. Through this damping switch, the damping rate of the plasmon can be actively tuned up to 1.7 fold. This Letter provides a prototype design to actively control the lifetime of graphene plasmons and also broadens our horizon for the damping control of other quasiparticle systems.

Mixed-Valence CsCu4Se3: Large Phonon Anharmonicity Driven by the Hierarchy of the Rigid [(Cu+)4(Se2-)2](Se-) Double Anti-CaF2 Layer and the Soft Cs+ Sublattice.

Crystalline solids that exhibit inherently low lattice thermal conductivity (κlat) have attracted a great deal of attention because they offer the only independent control for pursuing a high thermoelectric figure of merit (ZT). Herein, we report the successful preparation of CsCu4Q3 (Q = S (compound 1), Se (compound 2)) with the aid of a safe and facile boron-chalcogen method. The single-crystal diffraction data confirm the P4/mmm hierarchical structures built up by the mixed-valence [(Cu+)4(Q2-)2](Q-) double anti-CaF2 layer and the NaCl-type Cs+ sublattice involving multiple bonding interactions. The electron-poor compound CsCu4Q3 features Cu-Q antibonding states around EF that facilitates a high σ value of 3100 S/cm in 2 at 323 K. Significantly, the ultralow κlat value of 2, 0.20 W/m/K at 650 K (70% lower than that of Cu2Se), is mainly driven by the vibrational coupling of the rigid double anti-CaF2 layer and the soft NaCl-type sublattice. The hierarchical structure increases the bond multiplicity, which eventually leads to a large phonon anharmonicity, as evidenced by the effective scattering of the low-lying optical phonons to the heat-carrying acoustic phonons. Consequently, the acoustic phonon frequency in 2 drops sharply from 118 cm-1 (of Cu2Se) to 48 cm-1. In addition, the elastic properties indicate that the hierarchical structure largely inhibits the transverse phonon modes, leading to a sound velocity (1571 m/s) and a Debye temperature (189 K) lower than those of Cu2Se (2320 m/s; 292 K).

Formation of Bloch Flat Bands in Polar Twisted Bilayers without Magic Angles.

The existence of Bloch flat bands of electrons provides a facile pathway to obtain exotic quantum phases owing to strong correlation. Despite the established magic angle mechanism for twisted bilayer graphene, understanding of the emergence of flat bands in twisted bilayers of two-dimensional polar crystals remains elusive. Here, we show that due to the polarity between constituent elements in the monolayer, the formation of complete flat bands in twisted bilayers is triggered as long as the twist angle is less than a certain critical value. Using the twisted bilayer of hexagonal boron nitride (hBN) as an example, our simulations using the density-functional tight-binding method reveal that the flat band originates from the stacking-induced decoupling of the highest occupied (lowest unoccupied) states, which predominantly reside in the regions of the moiré superlattice where the anion (cation) atoms in both layers are overlaid. Our findings have important implications for the future search for and study of flat bands in polar materials.

Unconventional deformation potential and half-metallicity in zigzag nanoribbons of 2D-Xenes.

Realization of half-metallicity (HM) in low dimensional materials is a fundamental challenge for nano spintronics and a critical component for developing alternative generations of information technology. Using first-principles calculations, we reveal an unconventional deformation potential for zigzag nanoribbons (NRs) of 2D-Xenes. Both the conduction band minimum (CBM) and valence band maximum (VBM) of the edge states have negative deformation potentials. This unique property, combined with the localization and spin-polarization of the edge states, enables us to induce spin-splitting and HM using an inhomogeneous strain pattern, such as simple in-plane bending. Indeed, our calculation using the generalized Bloch theorem reveals the predicted HM in bent zigzag silicene NRs. Furthermore, the magnetic stability of the long range magnetic order for the spin-polarized edge states is maintained well against the bending deformation. These aspects indicate that it is a promising approach to realize HM in low dimensions with the zigzag 2D-Xene NRs.

Strain induced spin-splitting and half-metallicity in antiferromagnetic bilayer silicene under bending.

Searching for half-metals in low dimensional materials is not only of scientific importance, but also has important implications for the realization of spintronic devices on a small scale. In this work, we show theoretically that simple bending can induce spin-splitting in bilayer silicene. For bilayer silicene with Bernal stacking, the monolayer has a long range ferromagnetic spin order and between the two monolayers, the spin orders are opposite, giving rise to an antiferromagnetic configuration for the ground state of the bilayer silicene. Under bending, the antiferromagnetic spin order is retained but the energetic degeneracy of opposite spin states is lifted. Due to the unusual deformation potentials of the conduction band minimum (CBM) and valence band maximum (VBM) as revealed by density-functional theory calculations and density-functional tight-binding calculations, this spin-splitting is nearly proportional to the degree of bending deformation. Consequently, the spin-splitting can be significant and the desired half-metallic state may emerge when the bending increases, which has been verified by direct simulation of the bent bilayer silicene using the generalized Bloch theorem. Our results hint that bilayer silicene may be an excellent candidate for half-metallicity.

Indigo Naturalis Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice by Modulating the Intestinal Microbiota Community.

Indigo naturalis (IN) is a traditional Chinese medicine, named Qing-Dai, which is extracted from indigo plants and has been used to treat patients with inflammatory bowel disease (IBD) in China and Japan. Though there are notable effects of IN on colitis, the mechanisms remain elusive. Regarding the significance of alterations of intestinal flora related to IBD and the poor water solubility of the blue IN powder, we predicted that the protective action of IN on colitis may occur through modifying gut microbiota. To investigate the relationships of IN, colitis, and gut microbiomes, a dextran sulfate sodium (DSS)-induced mice colitis model was tested to explore the protective effects of IN on macroscopic colitis symptoms, the histopathological structure, inflammation cytokines, and gut microbiota, and their potential functions. Sulfasalazine (SASP) was used as the positive control. Firstly, because it was a mixture, the main chemical compositions of indigo and indirubin in IN were detected by ultra-performance liquid chromatography (UPLC). The clinical activity score (CAS), hematoxylin and eosin (H&E) staining results, and enzyme-linked immunosorbent assay (ELISA) results in this study showed that IN greatly improved the health conditions of the tested colitis mice, ameliorated the histopathological structure of the colon tissue, down-regulated pro-inflammatory cytokines, and up-regulated anti-inflammatory cytokines. The results of 16S rDNA sequences analysis with the Illumina MiSeq platform showed that IN could modulate the balance of gut microbiota, especially by down-regulating the relative quantity of Turicibacter and up-regulating the relative quantity of Peptococcus. The therapeutic effect of IN may be closely related to the anaerobic gram-positive bacteria of Turicibacter and Peptococcus. The inferred metagenomes from 16S data using PICRUSt demonstrated that decreased metabolic genes, such as through biosynthesis of siderophore group nonribosomal peptides, non-homologous end-joining, and glycosphingolipid biosynthesis of lacto and neolacto series, may maintain microbiota homeostasis during inflammation from IN treatment in DSS-induced colitis.

Tryptanthrin Protects Mice against Dextran Sulfate Sodium-Induced Colitis through Inhibition of TNF-α/NF-κB and IL-6/STAT3 Pathways.

Inflammatory bowel disease (IBD) is a notable health problem and may considerably affect the quality of human life. Previously, the protective roles of tryptanthrin (TRYP) against dextran sulfate sodium (DSS) induced colitis has been proved, but the concrete mechanism remained elusive. It has been suggested that TRYP could diminish the weight loss and improve the health conditions of mice with DSS induced colitis. Hematoxylin and eosin staining revealed that TRYP could improve the histopathological structure of the colon tissue. Two signaling pathways (TNF-α/NF-κBp65 and IL-6/STAT3) were investigated using immunochemistry and western blot. The detected concentrations of the two cytokines TNF-α and IL-6 showed that their levels decreased after TRYP treatment of the colitis. The protein expression level of NF-κBp65 in cytoplasm increased after TRYP treatment of the induced colitis. However, the protein level of NF-κBp65 in the nucleus decreased after administration of TRYP. The expression level of IκBα, the inhibitory protein of NF-κBp65, was tested and the results suggested that TRYP could inhibit the degradation of IκBα. The phosphorylation level of STAT3 was inhibited by TRYP and the expression level of STAT3 and p-STAT3 decreased after administration of TRYP. We conclude that TRYP improves the health condition of mice with DSS induced colitis by regulating the TNF-α/NF-κBp65 and IL-6/STAT3 signaling pathways via inhibiting the degradation of IκBα and the phosphorylation of STAT3.

Long non-coding RNA DANCR, a prognostic indicator, promotes cell growth and tumorigenicity in gastric cancer.

Gastric cancer remains the third leading cause of cancer-related mortality worldwide, and proliferation of gastric cancer represents the major reason for its poor prognosis. Recent evidence indicates that long non-coding RNAs play crucial roles in development and progression of gastric cancer. Long non-coding RNA differentiation antagonizing non-protein coding RNA is upregulated in hepatic cell carcinoma, but the role of lncRNA differentiation antagonizing non-protein coding RNA in gastric cancer has not been explored. In this article, we found that differentiation antagonizing non-protein coding RNA is also upregulated in gastric cancer. Experiments revealed that silencing differentiation antagonizing non-protein coding RNA significantly inhibited gastric cancer cell proliferation in vitro and in vivo. Overexpression of differentiation antagonizing non-protein coding RNA notably increases gastric cancer cell proliferation. From RNA-seq and gene ontology annotations, we found that differentiation antagonizing non-protein coding RNA influences the gene expression programs in cell metabolic and cycle process. Taken together, our findings suggest that the long non-coding RNA differentiation antagonizing non-protein coding RNA promotes the proliferation of gastric cancer and is a potential prognostic biomarker and therapeutic target in gastric cancer.

Antifungal Indole Alkaloids from Winchia calophylla.

Ten indole alkaloids (1-10) were obtained from an antifungal extract of Winchia calophylla, of which two (2 and 4) were new. N(4)-Methyl-10-hydroxyl-desacetylakuammilin (2) was an akuammiline-type indole alkaloid. N(1)-Methyl-echitaminic acid (4) was an unusual zwitterion with a basic vincorine-type skeleton. This is the first report of 10 in W. calophylla. The structures of all of the compounds were determined based on spectroscopic data, and their bioactivities were assessed. Compound 1 showed potent activity against the plant pathogenic fungi of Penicillium italicum and Fusarium oxysporum f.sp cubens with IC50 s of 10.4 and 11.5 µM, respectively, and 3 inhibited Rhizoctonia solani with an IC50 of 11.7 µM. Compounds 2 and 4 showed weak cytotoxicity against the human leukemic cell line HL-60 in vitro with IC50 s of 51.4 and 75.3 µM, respectively. Compounds 1 and 2 displayed weak activity against acetylcholinesterase with IC50 s around 61.3 and 52.6 µM, respectively.

Ervatamines A-I, Anti-inflammatory Monoterpenoid Indole Alkaloids with Diverse Skeletons from Ervatamia hainanensis.

Nine new monoterpenoid indole alkaloids, ervatamines A-I (1-9), and five known ones (10-14), were isolated from Ervatamia hainanensis. The new structures were elucidated by extensive spectroscopic analysis and comparison to known compounds. Their absolute configurations were determined by various methods including computational methods, X-ray diffraction analysis, and electronic circular dichroism spectroscopy, as well as chemical transformations. Ervatamine A (1) is a ring-C-contracted ibogan-type monoterpenoid indole alkaloid with an unusual 6/5/6/6/6 pentacyclic rearranged ring system. Ervatamines B-E (2-5) display a nitrogen-containing 9/6 ring system, which is rarely observed in nature. The epimeric ervatamines B (2) and C (3) possess a 22-nor-monoterpenoid indole alkaloid carbon skeleton, which was only found in deformylstemmadenine. Compounds 10 and 14 exhibited significant anti-inflammatory activities, with IC50 values of 25.5 and 41.5 µM, respectively, while the IC50 value of indomethacin as a positive control was found to be 42.6 µM. Additionally, compound 9 showed mild activity against 786-O and HL-60 cell lines.

Phonon quasiparticles and anharmonic free energy in complex systems.

We use a hybrid strategy to obtain anharmonic frequency shifts and lifetimes of phonon quasiparticles from first principles molecular dynamics simulations in modest size supercells. This approach is effective irrespective of crystal structure complexity and facilitates calculation of full anharmonic phonon dispersions, as long as phonon quasiparticles are well defined. We validate this approach to obtain anharmonic effects with calculations in MgSiO3 perovskite, the major Earth forming mineral phase. First, we reproduce irregular thermal frequency shifts of well characterized Raman modes. Second, we combine the phonon gas model (PGM) with quasiparticle frequencies and reproduce free energies obtained using thermodynamic integration. Combining thoroughly sampled quasiparticle dispersions with the PGM we then obtain first-principles anharmonic free energy in the thermodynamic limit (N→∞).

Strain-induced pseudomagnetic fields in twisted graphene nanoribbons.

We present, for the first time, an atomic-level and quantitative study of a strain-induced pseudomagnetic field in graphene nanoribbons with widths of hundreds of nanometers. We show that twisting strongly affects the band structures of graphene nanoribbons with arbitrary chirality and generates well-defined pseudo-Landau levels, which mimics the quantization of massive Dirac fermions in a magnetic field up to 160 T. Electrons are localized either at ribbon edges forming the edge current or at the ribbon center forming the snake orbit current, both being valley polarized. Our result paves the way for the design of new graphene-based nanoelectronics.

Lycodine-type alkaloids from Lycopodiastrum casuarinoides and their acetylcholinesterase inhibitory activity.

Four new lycodine-type alkaloids, namely 16-hydroxyhuperzine B (1), N-methyl-11-acetoxyhuperzine B (2), 8,15-dihydrolycoparin A (3) and (7S,12S,13R)-huperzine D-16-O-ß-d-glucopyranoside (4), along with ten known analogues 5-14, were isolated from the whole plant of Lycopodiastrum casuarinoides. The structures of the new compounds were elucidated by means of spectroscopic techniques (IR, MS, NMR, and CD) and chemical methods. Compounds 1 and 2 possessed four connected six-membered rings, while compounds 3 and 4 were piperidine ring cleavage products. In particular, compound 4 was a lycopodium alkaloidal glycoside which is reported for the first time. Among the isolated compounds N-demethylhuperzinine (7), huperzine C (8), huperzine B (9) and lycoparin C (13) possessed significant inhibitory activity against acetylcholinesterase, and the new compound 1 showed moderate inhibitory activity. The structure activity relationships were discussed.

YTHDF2 favors protumoral macrophage polarization and implies poor survival outcomes in triple negative breast cancer.

Patients with triple-negative breast cancer (TNBC) frequently experience resistance to chemotherapy, leading to recurrence. The approach of optimizing anti-tumoral immunological effect is promising in overcoming such resistance, given the heterogeneity and lack of biomarkers in TNBC. In this study, we focused on YTHDF2, an N6-methyladenosine (m6A) RNA-reader protein, in macrophages, one of the most abundant intra-tumoral immune cells. Using single-cell sequencing and ex vivo experiments, we discovered that YTHDF2 significantly promotes pro-tumoral phenotype polarization of macrophages and is closely associated with down-regulated antigen-presentation signaling to other immune cells in TNBC. The in vitro deprivation of YTHDF2 favors anti-tumoral effect. Expressions of multiple transcription factors, especially SPI1, were consistently observed in YTHDF2-high macrophages, providing potential therapeutic targets for new strategies. In conclusion, YTHDF2 in macrophages appears to promote pro-tumoral effects while suppressing immune activity, indicating the treatment targeting YTHDF2 or its transcription factors could be a promising strategy for chemoresistant TNBC.

Liquid Chromatography-Tandem Mass Spectrometry-Based Metabolomics Analysis of Indigo Naturalis Treatment of Ulcerative Colitis in Mice.

Ulcerative colitis (UC), often known as UC, is an inflammatory disease of the intestines that has frequent and long-lasting flare-ups. It is unknown precisely how the traditional Chinese drug Indigo Naturalis (IN) heals inflammatory bowel disease, despite its long-standing use in China and Japan. Finding new metabolite biomarkers linked to UC could improve our understanding of the disease, speed up the diagnostic process, and provide insight into how certain drugs work to treat the condition. Our work is designed to use a metabolomic method to analyze potential alterations in endogenous substances and their impact on metabolic pathways in a mouse model of UC. To determine which biomarkers and metabolisms are more frequently connected with IN's effects on UC, liquid chromatography-tandem mass spectrometry analysis of the serum metabolomics of UC mice and normal mice was performed. The outcomes demonstrated that IN boosted the health of UC mice and reduced the severity of their metabolic dysfunction. In the UC model, it was also found that IN changed the way 17 biomarkers and 3 metabolisms functioned.