Exploration of Ideological and political education in Instrumental Analysis Teaching

Instrumental analysis is an elective course for biology majors. In undergraduate teaching design, there are many ideological and political elements that can be combined with professional knowledge. The core of this paper is to advocate the spirit of innovation and practice, scientifi c spirit, humanistic quality, patriotism, etc., and integrate ideological and political teaching into the course teaching, so as to jointly play the role of Ideological and political education

Recipe for single-pair-Weyl-points phonons carrying the same chiral charges

Recently, Wang et al. [Phys. Rev. B, 106, 195129 (2022)] challenged a widely held belief in the field of Weyl physics, demonstrating that single-pair-Weyl-points (SP-WPs) can exist in nonmagnetic spinless systems, contrary to previous assumptions that they could only exist in magnetic systems. Wang et al. observed that the SP-WPs with opposite and even chiral charges (i.e., |C| = 2 or 4) could also exist in nonmagnetic spinless systems. In this Letter, we present a novel finding in which SP-WPs have a partner, namely a charged nodal surface, in nonmagnetic spinless systems. In contrast to previous observations, we show that the SP-WPs can have uneven chiral charges (i.e., |C| = 1). We identify 6 (out of 230) space groups (SGs) that contain such SP-WPs by searching the encyclopedia of emergent particles in three-dimensional crystals. Our finds were confirmed through the phonon spectra of two specific materials Zr3O (with SG 182) and NaPH2NO3 (with SG 173). This discovery broadens the range of materials that can host SP-WPs and applies to other nonmagnetic spinless crystals

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Phononic Weyl pair, phononic Weyl complex, phononic real Chern insulator state, and phononic corner modes in 2D Kekulé-order graphene

The conceptual framework of topological states has recently been extended to bosonic systems, particularly phononic systems. In this work, we chose the recently experimentally prepared two-dimensional (2D) Kekulé-order graphene as a target to propose the coexistence of gapless and gapped topological phonon states in its phonon curves. This is the first work to investigate rich gapped and gapless topological phonon states in experimentally feasible 2D materials. For the gapped topological phonons, 2D Kekulé-order graphene hosts phononic real Chern insulator states, i.e., second-order topological states, and corner vibrational modes inside frequency gaps at 27.96 and 37.065 THz. For the gapless topological phonons, 2D Kekulé-order graphene hosts a phononic Weyl pair [comprising two linear Weyl points (LWPs)] and a phononic Weyl complex [comprising one quadratic nodal point (QNP) and two LWPs] around 7.54 and 47.3 THz (39.2 THz), respectively. Moreover, the difference between the phononic Weyl pair and the phononic Weyl complex was investigated in detail. Our study not only promotes 2D Kekulé-order graphene as a concrete material platform for exploring the intriguing physics of phononic second-order topology but also proposes the coexistence of different categories of Weyl phonons, i.e., a Weyl complex that comprises two LWPs and one QNP, in two dimensions. Our work paves the way for new advancements in topological phononics comprising gapless and gapped topological phonons

Double dual-nodal-line semimetals with large surface density of states: Topological quantum catalysts for the hydrogen-evolution reaction

Topological quantum catalysts are developing rapidly due to the emergence of exotic quantum materials and their corresponding catalytic performance. Although tens of thousands of topological semimetals have been developed, their low topological surface density of states (DOSs) remains a hindrance to the development of high-performance catalysts for electrochemical hydrogen evolution reactions (HERs). In this work, we investigate the potential of double dual-nodal line (DDNL) semimetals, which exhibit large surface DOSs and fair-low Gibbs free energies, as ideal topological quantum catalysts (TQCs) for HER. Using the NaAlGe compound as a representative example, we demonstrate that its DDNLs and high surface DOSs around the Fermi level provide advantages for achieving exceptionally high catalytic activity in the electrochemical HER process. Through a comparison of catalytic performance under different (electron and hole) doping and uniaxial strain conditions, we establish a linear correlation between the Gibbs free energy (ΔGH - ) and the projected surface DOSs on the (001) semi-infinite surface of the DDNL semimetal NaAlGe, specifically for the hydrogen evolution process. Our work introduces an alternative category of high-performance TQCs free of noble metals and contributes to a better understanding of the relationship between catalytic performance for HER and surface DOSs in DDNL semimetals

SHMT1 inhibits the metastasis of HCC by repressing NOX1-mediated ROS production

Abstract Background Hepatocellular carcinoma (HCC) is the most major type of primary hepatic cancer. Serine hydroxymethyltransferase 1 (SHMT1) is recently found to play critical roles in human cancers including lung cancer, ovarian cancer and intestinal cancer. However, the expression, function and the underlying mechanisms of SHMT1 in HCC remain uncovered. Methods qRT-PCR, immunohistochemistry and immunoblotting were performed to detect the expression of SHMT1 in HCC tissues and cell lines. HCC cell migration and invasion were determined by Boyden chamber and Transwell assay in vitro, and tumor metastasis was assessed via lung metastasis model in mice. The expression of key factors involved in epithelial-to-mesenchymal transition (EMT) process was evaluated by western blotting. Results In this study, data mining of public databases and analysis of clinical specimens demonstrated that SHMT1 expression was decreased in HCC. Reduced SHMT1 level was correlated with unfavorable clinicopathological features and poor prognosis of HCC patients. Gain- and loss-of-function experiments showed that SHMT1 overexpression inhibited the migration and invasion of HCCLM3 cells while SHMT1 knockdown enhanced the metastatic ability of Hep3B cells. Furthermore, qRT-PCR and western blotting showed that SHMT1 inhibited EMT and matrix metallopeptidase 2 (MMP2) expression. In vivo experiments showed that SHMT1 suppressed the lung metastasis of HCC cells in mice. Mechanistically, SHMT1 knockdown enhanced reactive oxygen species (ROS) production, and thus promoted the motility, EMT and MMP2 expression in Hep3B cells. Furthermore, NADPH oxidase 1 (NOX1) was identified to be the downstream target of SHMT1 in HCC. NOX1 expression was negatively correlated with SHMT1 expression in HCC. Rescue experiments revealed that NOX1 mediated the functional influence of SHMT1 on HCC cells. Conclusions These data indicate that SHMT1 inhibits the metastasis of HCC by repressing NOX1 mediated ROS production

Effects of Acupuncture on 1-chloro-2,4-dinitrochlorobenzene-induced Allergic Contact Dermatitis in Mice

Allergic contact dermatitis (ACD) is a chronic inflammatory skin disease. Topical corticosteroids are the first-line therapy for ACD despite their significant adverse effects. Acupuncture has been widely used in the treatment of various skin diseases, but its underlying mechanism remains unrevealed. In this study, we investigated the characteristics of acupuncture treatment based on effectiveness and mechanism. BALB/c mice received 1-chloro-2,4-dinitrobenzene (DNCB) application to build AD-like model. Results showed that acupuncture was an effective treatment method in inhibiting inflammatory conditions, serum IgE levels, and expression of proinflammatory cytokine Th2 (IL-4, IL-6), and Th2 (IL-1β, TNF-α) mRNA compared with DNCB treatment. Acupuncture treatment also inhibited nuclear factor-κB p65, phosphorylation of IκBα, and phosphorylation of occludin proteins expression. Furthermore, it could improve the expression of epidermal growth factor in both mRNA and protein levels. These results suggest that acupuncture, as an alternative therapy treatment for its no significant side effects, was effective in alleviating ACD by reducing proinflammatory cytokines and changing proteins' expression

Magnetic Second-Order Topological Insulator: An Experimentally Feasible 2D CrSiTe3

2D second-order topological insulators (SOTIs) have sparked significant interest, but currently, the proposed realistic 2D materials for SOTIs are limited to nonmagnetic systems. In this study, for the first time, a single layer of chalcogenide CrSiTe3—an experimentally realized transition metal trichalcogenide is proposed with a layer structure—as a 2D ferromagnetic (FM) SOTI. Based on first-principles calculations, this study confirms that the CrSiTe3 monolayer exhibits a nontrivial gapped bulk state in the spin-up channel and a trivial gapped bulk state in the spin-down channel. Based on the higher-order bulk–boundary correspondence, it demonstrates that the CrSiTe3 monolayer exhibits topologically protected corner states with a quantized fractional charge ((Formula presented.)) in the spin-up channel. Notably, unlike previous nonmagnetic examples, the topological corner states of the CrSiTe3 monolayer are spin-polarized and pinned at the corners of the sample in real space. Furthermore, the CrSiTe3 monolayer retains SOTI features when the spin–orbit coupling (SOC) is considered, as evidenced by the corner charge and corner states distribution. Finally, by applying biaxial strain and hole doping, this study transforms the magnetic insulating bulk states into spin-gapless semiconducting and half-metallic bulk states, respectively. Importantly, the topological corner states persist in the spin-up channel under these conditions

Hydrolysis of Solid Buffer Enables High‐Performance Aqueous Zinc Ion Battery

Abstract Aqueous zinc (Zn) ion batteries (AZIBs) have not yet fulfilled their talent of high safety and low cost since the anode/electrolyte interface (AEI) has long been impeded by hydrogen evolution, surface corrosion, dendritic growth, and by‐product accumulation. Here, the hydrolysis of solid buffers is elaborately proposed to comprehensively and enduringly handle these issues. Take 2D layered black phosphorus (BP) as a hydrolytic subject. It is reported that the phosphoric acid generated by hydrolysis in an aqueous electrolyte produces a zinc phosphate (ZPO) rich solid electrolyte interphase (SEI) layer, which largely inhibits the dendrite growth, surface corrosion, and hydrogen evolution. Meanwhile, the hydrolytic phosphoric acid stabilizes the pH value near AEI, avoiding the accumulation of alkaline by‐products. Notably, compared with the disposable ZPO engineerings of anodic SEI pre‐construction and electrolyte additive, the hydrolysis strategy of BP can realize a dramatically prolonged protective effect. As a result, these multiple merits endow BP modified separator to achieve improved stripping/plating stability toward Zn anode with more than ten times lifespan enhancement in Zn||Zn symmetrical cell. More encouragingly, when coupled with a V2O5·nH2O cathode with ultra‐high loadings (34.1 and 28.7 mg cm−2), the cumulative capacities are remarkably promoted for both coin and pouch cells