1T'-transition metal dichalcogenide monolayers stabilized on 4H-Au nanowires for ultrasensitive SERS detection.

Unconventional 1T'-phase transition metal dichalcogenides (TMDs) have aroused tremendous research interest due to their unique phase-dependent physicochemical properties and applications. However, due to the metastable nature of 1T'-TMDs, the controlled synthesis of 1T'-TMD monolayers (MLs) with high phase purity and stability still remains a challenge. Here we report that 4H-Au nanowires (NWs), when used as templates, can induce the quasi-epitaxial growth of high-phase-purity and stable 1T'-TMD MLs, including WS2, WSe2, MoS2 and MoSe2, via a facile and rapid wet-chemical method. The as-synthesized 4H-Au@1T'-TMD core-shell NWs can be used for ultrasensitive surface-enhanced Raman scattering (SERS) detection. For instance, the 4H-Au@1T'-WS2 NWs have achieved attomole-level SERS detections of Rhodamine 6G and a variety of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike proteins. This work provides insights into the preparation of high-phase-purity and stable 1T'-TMD MLs on metal substrates or templates, showing great potential in various promising applications.

Characteristic Plasmon Energies for 2D In2Se3 Phase Identification at Nanoscale.

Two-dimensional (2D) materials with competing polymorphs offer remarkable potential to switch the associated 2D functionalities for novel device applications. Probing their phase transition and competition mechanisms requires nanoscale characterization techniques that can sensitively detect the nucleation of secondary phases down to single-layer thickness. Here we demonstrate nanoscale phase identification on 2D In2Se3 polymorphs, utilizing their distinct plasmon energies that can be distinguished by electron energy-loss spectroscopy (EELS). The characteristic plasmon energies of In2Se3 polymorphs have been validated by first-principles calculations, and also been successfully applied to reveal phase transitions using in situ EELS. Correlating with in situ X-ray diffraction, we further derive a subtle difference in the valence electron density of In2Se3 polymorphs, consistent with their disparate electronic properties. The nanometer resolution and independence of orientation make plasmon-energy mapping a versatile technique for nanoscale phase identification on 2D materials.

Hydroxide and Hydronium Ions Modulate the Dynamic Evolution of Nitrogen Nanobubbles in Water.

It has been widely recognized that the pH environment influences the nanobubble dynamics and hydroxide ions adsorbed on the surface may be responsible for the long-term survival of the nanobubbles. However, understanding the distribution of hydronium and hydroxide ions in the vicinity of a bulk nanobubble surface at a microscopic scale and the consequent impact of these ions on the nanobubble behavior remains a challenging endeavor. In this study, we carried out deep potential molecular dynamics simulations to explore the behavior of a nitrogen nanobubble under neutral, acidic, and alkaline conditions and the inherent mechanism, and we also conducted a theoretical thermodynamic and dynamic analysis to address constraints related to simulation duration. Our simulations and theoretical analyses demonstrate a trend of nanobubble dissolution similar to that observed experimentally, emphasizing the limited dissolution of bulk nanobubbles in alkaline conditions, where hydroxide ions tend to reside slightly farther from the nanobubble surface than hydronium ions, forming more stable hydrogen bond networks that shield the nanobubble from dissolution. In acidic conditions, the hydronium ions preferentially accumulating at the nanobubble surface in an orderly manner drive nanobubble dissolution to increase the entropy of the system, and the dissolved nitrogen molecules further strengthen the hydrogen bond networks of systems by providing a hydrophobic environment for hydronium ions, suggesting both entropy and enthalpy effects contribute to the instability of nanobubbles under acidic conditions. These results offer fresh insights into the double-layer distribution of hydroxide and hydronium near the nitrogen-water interface that influences the dynamic behavior of bulk nanobubbles.

Facet-Dependent Surface Restructuring on Nickel (Oxy)hydroxides: A Self-Activation Process for Enhanced Oxygen Evolution Reaction.

Unraveling the catalyst surface structure and behavior during reactions is essential for both mechanistic understanding and performance optimization. Here we report a phenomenon of facet-dependent surface restructuring intrinsic to ß-Ni(OH)2 catalysts during oxygen evolution reaction (OER), discovered by the correlative ex situ and operando characterization. The ex situ study after OER reveals ß-Ni(OH)2 restructuring at the edge facets to form nanoporous Ni1-xO, which is Ni deficient containing Ni3+ species. Operando liquid transmission electron microscopy (TEM) and Raman spectroscopy further identify the active role of the intermediate ß-NiOOH phase in both the OER catalysis and Ni1-xO formation, pinpointing the complete surface restructuring pathway. Such surface restructuring is shown to effectively increase the exposed active sites, accelerate Ni oxidation kinetics, and optimize *OH intermediate bonding energy toward fast OER kinetics, which leads to an extraordinary activity enhancement of ∼16-fold. Facilitated by such a self-activation process, the specially prepared ß-Ni(OH)2 with larger edge facets exhibits a 470-fold current enhancement than that of the benchmark IrO2, demonstrating a promising way to optimize metal-(oxy)hydroxide-based catalysts.

A nature-inspired multifunctional adhesive for cartilage tissue-biomaterial integration.

Surgical adhesives play a crucial role in tissue integration and repair, yet their application in wet conditions has been severely limited by inadequate adhesive strength and subpar biocompatibility. Furthermore, tissue adhesives have rarely been reported in cartilage tissue repair. In this study, a three-armed dopamine-modified hyaluronic acid derivative adhesive was prepared to function as a bio-inspired adhesive in moist environments. To meet the clinical requirements for cartilage tissue adhesion, we studied its chemical structure, including microscopic morphology, adhesion properties with materials and tissues, in vivo degradation rules, and biological evaluation. The OGMHA8-DOPA adhesive with the optimal aldehyde substitution degree and dopamine-grafting rate was determined by analyzing the experimental conditions. SEM results revealed that the cartilage tissue adhered to a porous interconnected structure. The excellent biocompatibility of the material not only facilitated chondrocyte adhesion but also supported their proliferation on its surface. Animal experiments have demonstrated that this material has no observable inflammatory response or incidence of fibrous capsule formation. The degradation timeline of the material extends beyond the duration of two weeks. The dopamine-modified adhesive exhibited a tight interfacial binding force between the biomaterial and cartilage tissue and excellent biocompatibility in watery tissue, revealing its potential for application in cartilage tissue repair and minimally invasive surgery.

Exploring the Dual Functions of Distal Acyl Group Direction in Various Nucleophilic Environments.

A universal glycosylation strategy could significantly simplify glycoside synthesis. One approach to achieving this goal is through acyl group direction for the corresponding 1,2-, 1,3-, 1,4-, or 1,6-trans glycosylation; however, this approach has been challenging for glycosidic bonds that require distal equatorial-acyl group direction. We developed an approach in weakly nucleophilic environments for selective 1,4-trans glycosylation directed by the equatorial-4-O-acyl group. Here, we explored this condition in other distal acyl groups and found that, besides 1,n-trans direction, acyl groups also mediated hydrogen bonding between acyl groups and alcohols. The latter showed a diverse effect and classified the acyl group direction into axial and equatorial categories. Corresponding glycosylation conditions were distinguished as guidance for acyl group direction from either category. Hence, acyl group direction may serve as a general glycosylation strategy.

Hollow-Carbon Confinement Annealing: A New Synthetic Approach to Make High-Entropy Solid-Solution and Intermetallic Nanoparticles.

High-entropy alloy (HEA) nanoparticles (NPs) have been emerging with superior compositional tunability and multielemental synergy, presenting a unique platform for material discovery and performance optimization. Here we report a synthetic approach utilizing hollow-carbon confinement in the ordinary furnace annealing to achieve the nonequilibrium HEA-NPs such as Pt0.45Fe0.18Co0.12Ni0.15Mn0.10 with uniform size ∼5.9 nm. The facile temperature control allows us not only to reveal the detailed reaction pathway through ex situ characterization but also to tailor the HEA-NP structure from the crystalline solid solution to intermetallic. The preconfinement of metal precursors is the key to ensure the uniform distribution of metal nanoparticles with confined volume, which is essential to prevent the thermodynamically favored phase separation even during the ordinary furnace annealing. Besides, the synthesized HEA-NPs exhibit remarkable activity and stability in oxygen reduction catalysis. The demonstrated synthetic approach may significantly expand the scope of HEA-NPs with uncharted composition and performance.

Synergism of Surfactant Mixture in Lowering Vapor-Liquid Interfacial Tension.

Through employing molecular dynamics, in this work, we study how a two-component surfactant mixture cooperatively reduces the interfacial tension of a flat vapor-liquid interface. Our simulation results show that in the presence of a given insoluble surfactant, adding a secondary surfactant would either further reduce interfacial tension, indicating a positive synergistic effect, or increase the interfacial tension instead, indicating a negative synergistic effect. The synergism of the surfactant mixture in lowering surface tension is found to depend strongly on the structure complementary effect between different surfactant components. The synergistic mechanisms are then interpreted with minimization of the bending free energy of the composite surfactant monolayer via cooperatively changing the monolayer spontaneous curvature. By roughly describing the monolayer spontaneous curvature with the balanced distribution of surfactant heads and tails, we confirm that the positive synergistic effect in lowering surface tension is featured with the increasingly symmetric head-tail distributions, while the negative synergistic effect is featured with the increasingly asymmetric head-tail distributions. Furthermore, our simulation results indicate that minimal interfacial tension can only be observed when the spontaneous curvature is nearly zero.

Uptight responses between clenching and forearm raising with factors of visual feedback and maintenance effort in healthy young women: An experimental study on factorial design.

BACKGROUND: To achieve different central preset force levels requires various fine-tuning efforts and may elicit different uptight responses. The mandibular lever system has a distinct regularity in the fine-tuning function of the upper limbs. The purpose of the present study was to detect whether the uptight responses elicited from motivating clenching differ from those induced by motivating forearm raising at different force levels. METHODS: Twenty-five healthy females were enrolled in this study. The target was low, medium, and maximum force levels with or without visual feedback and/or maintenance effort. Surface electromyographic (SEMG) activity was recorded from the bilateral anterior temporalis and masseter or left biceps brachii muscle (BicL), and the T-Scan III System synchronously recorded the sensitive force values. The uptight responses and task difficulties were recorded for occlusal and left forearm lifting tasks using a unique visual analogue scale. RESULTS: The highest uptight response value was achieved at a low clenching force level with visual feedback requiring no maintenance effort but at a maximum forearm-raising force level with visual feedback and maintenance effort. The SEMG activities of both jaw-closing muscles and BicL were associated with the central preset force level (P < 0.001). However, the maintenance effort only increased the jaw-closing muscles' SEMG activity at the maximal force level (P < 0.001). CONCLUSIONS: Clenching at the central preset lower force level with visual feedback is prone to elicit a higher degree of uptight response. The constant need for a low-intensity bite can have a negative effect on an individual's mood.

Stabilizing Interfaces in High-Temperature NCM811-Li Batteries via Tuning Terminal Alkyl Chains of Ether Solvents.

Ether electrolytes are promising for lithium metal batteries. Despite the intensive research in recent years, most state-of-the-art ether electrolytes still cannot form reliable electrode-electrolyte interfaces in NCM811-Li batteries at diluted concentrations, especially in those operating at elevated temperatures. We report a simple but effective strategy to break this bottleneck and stabilize interfaces in high-temperature NCM811-Li batteries in ether electrolytes. We propose that by gradually extending the terminal groups of glycol diethers from methyl groups to n-butyl groups, the comprehensive stability of ether electrolytes is improved. An anion-dominated solvation structure is realized at a concentration of 1 M. Accordingly, the electrode-electrolyte interactions are suppressed, and a thinner, denser, and more inorganic-rich solid- /cathode-electrolyte interface is achieved. Additionally, the surface phase transition and structural degradation of NCM811 cathode are alleviated. Consequently, in the ethylene glycol dibutyl ether-based electrolyte, the Coulombic efficiency for Li-Cu cells working at 60 °C is boosted to 99.41 % with a cycling life of over 200 cycles. The lifespan of high-temperature NCM811-Li cells is prolonged by more than 400 % with a stable average Coulombic efficiency of 99.77 % at quasi-practical conditions of 50 µm Li, lean electrolyte of 10 µL mAh-1 , and medium-high cathode loading of >2.2 mAh cm-2 .

Establishment of Zebrafish Models for Diabetes Mellitus and Its Microvascular Complications.

Diabetes mellitus (DM) is a chronic metabolic disease known to cause several microvascular complications, including diabetic retinopathy, diabetic nephropathy, and diabetic neuropathy. Hyperglycemia plays a key role in inducing diabetic microvascular complications. A cohort of diabetic animal models has been established to study diabetes-related vascular diseases. However, the zebrafish model offers unique advantages in this field. The tiny size and huge offspring numbers of zebrafish make it amenable to perform large-scale analysis or screening. The easily accessible strategies for gene manipulation with morpholino or CRISPR/Cas9 and chemical/drug treatment through microinjection or skin absorption allow establishing the zebrafish DM models by a variety of means. In addition, the transparency of zebrafish embryos makes it accessible to perform in vivo high-resolution imaging of the vascular system. In this review, we focus on the strategies to establish diabetic or hyperglycemic models with zebrafish and the achievements and disadvantages of using zebrafish as a model to study diabetic microvascular complications.

Using noninvasive anthropometric indices to develop and validate a predictive model for metabolic syndrome in Chinese adults: a nationwide study.

PURPOSE: Metabolic syndrome (Mets) is a pathological condition that includes many abnormal metabolic components and requires a simple detection method for rapid use in a large population. The aim of the study was to develop a diagnostic model for Mets in a Chinese population with noninvasive anthropometric and demographic predictors. PATIENTS AND METHODS: Least absolute shrinkage and selection operator (LASSO) regression was used to screen predictors. A large sample from the China National Diabetes and Metabolic Disorders Survey (CNDMDS) was used to develop the model with logistic regression, and internal, internal-external and external validation were conducted to evaluate the model performance. A score calculator was developed to display the final model. RESULTS: We evaluated the discrimination and calibration of the model by receiver operator characteristic (ROC) curves and calibration curve analysis. The area under the ROC curves (AUCs) and the Brier score of the original model were 0.88 and 0.122, respectively. The mean AUCs and the mean Brier score of 10-fold cross validation were 0.879 and 0.122, respectively. The mean AUCs and the mean Brier score of internal-external validation were 0.878 and 0.121, respectively. The AUCs and Brier score of external validation were 0.862 and 0.133, respectively. CONCLUSIONS: The model developed in this study has good discrimination and calibration performance. Its stability was proved by internal validation, external validation and internal-external validation. Then, this model has been displayed by a calculator which can exhibit the specific predictive probability for easy use in Chinese population.

Gas-liquid transition of van der Waals fluid confined in fluctuating nano-space.

Gas-liquid transition is generally a complex process, which involves nucleation of droplets and their growth by evaporation-condensation or collision-coalescence processes. Here, we focus on a microscopic system in which there is only one liquid droplet at most. In this case, we can develop an equilibrium theory for the formation of the droplet in the gas phase using the classical nucleation theory. We use the van der Waals fluid model with surface tension and calculate the size fluctuation of the droplet for various confinement conditions, NVT (in which the volume V of the system is fixed), NPT (in which the pressure P of the system is fixed), and NBT (in which the system is confined in a nano-bubble immersed in a host liquid, where both V and P can fluctuate). We show that in the NBT system, the size flexibility along with space confinement induces a wealth of properties that are not found in NVT and NPT. It exhibits richer phase behaviors: a stable droplet appears and coexists with the pure gas phase and/or pure liquid phase. When compared to the NVT system, the NBT system shows not only the oscillatory fluctuation between the two stable states but also a large fluctuation in the total volume and the pressure.

Constructing and validating nomograms to predict risk and prognostic factors of distant metastasis in urothelial bladder cancer patients: a population-based retrospective study.

BACKGROUND: Urothelial carcinoma is the most common type of bladder cancer worldwide and it has a poor prognosis for patients with distant metastasis. Nomograms are frequently used in clinical research, but no research has evaluated the diagnostic and prognostic factors of distant metastasis in urothelial bladder cancer (UBC). METHODS: The Surveillance, Epidemiology, and End Results database was used to analyze all patients diagnosed with UBC between 2000 and 2017. Lasso regression was used to identify the potential risk predictive factors for distant metastasis in UBC. Univariate and multivariate Cox proportional hazard regression analyses were performed to determine independent prognostic factors for distant metastasis urothelial bladder cancer (DMUBC). Subsequently, two nomograms were constructed based on the above models. The receiver operating characteristic (ROC), and calibration curves were performed to evaluate the two nomograms. RESULTS: The study included 73,264 patients with UBC, with 2,129 (2.9%) having distant metastasis at the time of diagnosis. In the diagnostic model, tumor size, histologic type, and stage N and T were all important risk predictive factors for distant metastasis of UBC. In the prognostic model, age, tumor size, surgery, and chemotherapy were independent factors affecting the prognosis of DMUBC. DCA, ROC, calibration, and Kaplan-Meier (K-M) survival curves reveal that the two nomograms can effectively predict the diagnosis and prognosis of DMUBC. CONCLUSION: The developed nomograms are practical methods for predicting the occurrence risk and prognosis of distant metastasis urothelial bladder cancer patients, which may benefit the clinical decision-making process.

Neuron navigator 3 (NAV3) is required for heart development in zebrafish.

As a tightly controlled biological process, cardiogenesis requires the specification and migration of a suite of cell types to form a particular three-dimensional configuration of the heart. Many genetic factors are involved in the formation and maturation of the heart, and any genetic mutations may result in severe cardiac failures. The neuron navigator (NAV) family consists of three vertebrate homologs (NAV1, NAV2, and NAV3) of the neural guidance molecule uncoordinated-53 (UNC-53) in Caenorhabditis elegans. Although they are recognized as neural regulators, their expressions are also detected in many organs, including the heart, kidney, and liver. However, the functions of NAVs, regardless of neural guidance, remain largely unexplored. In our study, we found that nav3 gene was expressed in the cardiac region of zebrafish embryos from 24 to 48 h post-fertilization (hpf) by means of in situ hybridization (ISH) assay. A CRISPR/Cas9-based genome editing method was utilized to delete the nav3 gene in zebrafish and loss of function of Nav3 resulted in a severe deficiency in its cardiac morphology and structure. The similar phenotypic defects of the knockout mutants could recur by nav3 morpholino injection and be rescued by nav3 mRNA injection. Dual-color fluorescence imaging of ventricle and atrium markers further confirmed the disruption of the heart development in nav3-deleted mutants. Although the heart rate was not affected by the deletion of nav3, the heartbeat intensity was decreased in the mutants. All these findings indicate that Nav3 was required for cardiogenesis in developing zebrafish embryos.

Robust and Flexible Random Lasers Using Perovskite Quantum Dots Coated Nickel Foam for Speckle-Free Laser Imaging.

The advantage of using flexible metallic structures as the substrate of flexible lasers over plastic materials is its strong mechanical strength and high thermal conductivity. Here, it is proposed to deposit CsPbBr3 perovskite quantum dots onto Ni porous foam for the realization of flexible lasers. Under two-photon 800 nm excitation at room temperature, incoherent random lasing emission is observed at ≈537 nm. By external deformation of the Ni porous foam, incoherent random lasing can be tuned to amplified spontaneous emission as well as the corresponding lasing threshold be controlled. More importantly, it is demonstrated that the laser is robust to intensive bending (>1000 bending cycles) with minimum effect on the lasing intensity. This flexible laser is also shown to be an ideal light source to produce a "speckle" free micro-image.

Reinvestigation of N,N-Diacetylimido-Protected 2-Aminothioglycosides in O-Glycosylation: Intermolecular Hydrogen Bonds Contributing to 1,2-Orthoamide Formation.

N,N-Diacetylimido protection of 2-aminoglycosides is an elegant strategy but has had limited applications due to unexpected side reactions in glycosylation. We found that high acid concentrations could diminish the side reactions. We observed intermolecular hydrogen bonding among alcohols and acids could disrupt. Assuming that intermolecular hydrogen bonding accelerates the formation of 1,2-orthoamides and disrupting intermolecular hydrogen bonds could turn to the desired glycosylation, we successfully employed sulfenyl triflate pre-activation in the glycosylation of a broad scope of alcohol acceptors, as well as in a one-pot synthesis of a protected human milk oligosaccharide, lacto-N-neotetraose.

Systematic profiling of early regulators during tissue regeneration using zebrafish model.

Great progresses have been made in comprehension of tissue regeneration process. However, one of the central questions in regeneration research remains to be deciphered is what factors initiate regenerative process. In present study, we focused on systematic profiling of early regulators in tissue regeneration via high-throughput screening on zebrafish caudal fin model. Firstly, 53 GO-annotated regeneration-related genes, which were specifically activated upon fin amputation, were identified according to the transcriptomic analysis. Moreover, qRT-PCR analysis of a couple of randomly selected genes from the aforementioned gene list validated our sequencing results. These studies confirmed the reliability of transcriptome sequencing analysis. Fibroblast growth factor 20a (fgf20a) is a key initial factor in the regeneration of zebrafish. Through a gene expression correlation analysis, we discovered a collection of 70 genes correlating with fgf20a, whose expression increased promptly at 2 days post amputation (dpa) and went down to the basal level until the completion of fin regeneration. In addition, two genes, socs3b and nppc, were chosen to investigate their functions during the fin regeneration. Inhibition of either of those genes significantly delayed the regenerative process. Taken together, we provided a simple and effective time-saving strategy that may serve as a tool for identifying early regulators in regeneration and identified 71 genes as early regulators of fin regeneration.

Insight into transketolase of Pyropia haitanensis under desiccation stress based on integrative analysis of omics and transformation.

BACKGROUND: Pyropia haitanensis, distributes in the intertidal zone, can tolerate water losses exceeding 90%. However, the mechanisms enabling P. haitanensis to survive harsh conditions remain uncharacterized. To elucidate the mechanism underlying P. haitanensis desiccation tolerance, we completed an integrated analysis of its transcriptome and proteome as well as transgenic Chlamydomonas reinhardtii carrying a P. haitanensis gene. RESULTS: P. haitanensis rapidly adjusted its physiological activities to compensate for water losses up to 60%, after which, photosynthesis, antioxidant systems, chaperones, and cytoskeleton were activated to response to severe desiccation stress. The integrative analysis suggested that transketolase (TKL) was affected by all desiccation treatments. Transgenic C. reinhardtii cells overexpressed PhTKL grew better than the wild-type cells in response to osmotic stress. CONCLUSION: P. haitanensis quickly establishes acclimatory homeostasis regarding its transcriptome and proteome to ensure its thalli can recover after being rehydrated. Additionally, PhTKL is vital for P. haitanensis desiccation tolerance. The present data may provide new insights for the breeding of algae and plants exhibiting enhanced desiccation tolerance.

Purification, identification and characterization of an esterase with high enantioselectivity to (S)-ethyl indoline-2-carboxylate.

OBJECTIVE: To purify an esterase which can selectively hydrolyze (R,S)-ethyl indoline-2-carboxylate to produce (S)-indoline-2-carboxylic acid and characterize its enzymatic properties. RESULTS: An intracellular esterase from Bacillus aryabhattai B8W22 was isolated and the purified protein was identified as a carboxylesterase by MALDI-TOF mass spectrometry. The enzyme (named BaCE) was 59.03-fold purification determined to be of approximately 35 kDa. Its specific activity was 0.574 U/mL with 20% yield. The enzyme showed maximum activity at pH 8.5 and 30 °C and was stable at 20-30 °C using pNPB as the substrate. The Km, Vmax, kcat and kcat/Km of the esterase were 0.52 mM, 6.39 µM/min, 26.87 min-1 and 51.67 mM/min, respectively. The esterase demonstrated high enantioselectivity toward (S)-ethyl indoline-2-carboxylate with 96.55% e.e.p at 44.39% conversion, corresponding to an E value of 133.45. CONCLUSIONS: In this study, a new esterase BaCE with an apparent molecular mass of 35 kDa was purified to homogeneity for the first time. The esterase from Bacillus aryabhattai B8W22 was isolated with a purification more than 59-fold and a yield of 20% by anion exchange chromatography and hydrophobic interaction chromatography. And its biochemical characterization were described in detail with pNPB as substrate. It displayed high enantioselectivity toward (S)-ethyl indoline-2-carboxylate. We next plan to highly express esterase BaCE in Escherichia coli, and apply it to industrial production of (S)-indoline-2-carboxylic acid.