Search

As the field of microfluidics continues to grow, there is an increasing demand for public education about this technology. This article presents a quick, simple, safe, and inexpensive method for teaching microfiuidics to younger students and the general public. (To listen to a podcast about this article, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/anchem/audio/ index.html.) 10.1021/ac902926x

Au-Pd bimetallic model catalysts are synthesized as alloy clusters on SiO2 films and are used for a variety of reactions. The surface composition, physical structure, catalytic properties and morphology are characterized which is critical to understand the role Au plays in enhancing the catalytic properties of Pd.

The study was done using the metastable impact electron spectroscopy of adsorbed xenon (MAX), which can provide accurate information on the binding energies, energy positions, and the widths of the Xenon 5p states. The study suggests that MAX can be used for quantitative characterizations of uniform and nonuniform surfaces in metals as well as wide gap materials.

The electronic and chemical properties of Ag cluster on MgO (100) films grown on Mo (100) are studied using metastable impact electron and ultraviolet photoelectron spectroscopies (MIES/UPS) and temperature programmed desorption (TDP). It was found that the defect sites alters the properties of metal/oxide catalyst and due to strong interaction between Ag and defect sites there is a change observed in the chemical properties of Ag cluster.

A modular route in generating ligands made from phosphine-containing acids and various amino acids employs an alkyl chain as a bridging structure connecting chelating functionalities. This allows the addition of a second chiral center next to the phosphine substituent. The resulting product is a diastereomeric ligand containing two chiral centers which can act either in concert or dissonance.

The disugar diphosphine ligands, benzyl- and methyl-protected diphosphines (9 and 10) are prepared and are then used in the asymmetric hydrogenation of alpha-(N-acetylamino)acrylate leading to products in high enantiomeric excess. The disugar D-trehalose is used as the starting material which is subsequently protected to yield 9 and 10.

The characterization of newly developed sonication-mediated glycosylation protocol for the synthesis of oligomannosides is described. The protocol could also be applied to the glycosyl donors that are known to have low reactivity.

It is proposed that altering the electrochemical properties of the reaction center can change regiospecificity of hydride transfer catalyzed by a pyridine nucleotide-dependent enzyme. The difluoromethylene functionality has assumed a role as a carbonyl mimic with an apparently reversed regioselectivity of hydride reduction.

Research is presented demonstrating the direct association of a radical with the PMP coenzyme in E1 catalysis, using EPR and isotopic PMP labeling techniques.

The enzyme CDP-D-glucose 4,6-dehydratase (E(sub od)), which was isolated from Yersinia pseudotuberculosis, is characterized. The enzyme catalyzes the transformation of CDP-D-glucose to CDP-6-deoxy-L-threo-D-glycero-4-hexulose. Substrate analogues were prepared that would lead to either inhibition or turnover to develop methods to control or regulate the conversion. The E(sub od) reaction has been distinguished as the common entry in the formation of all 6-deoxyhexoses.

Multilayered microstructures can accelerate the proton conduction process in proton exchange membranes (PEMs). Herein, we design and construct PEMs with microstructures based on bifunctional nanofibers and sulfonated poly(ether ether ketone) (SPEEK) nanofibers. Specifically, the bifunctional nanofibers composed of poly(vinyl alcohol) and chitosan are prepared and then combined with the electrospun SPEEK nanofibers. The stable microstructure is derived from the compatible interfacial property of nanofibers and the formed hydrogen bonds. The multilayered microstructure consisting of nanofibers accelerates the proton conduction even at subzero temperature because of regulating the proton conduction pathways. Specifically, the (SKNF/CPNF/SKNF)/PA membrane exhibits the proton conductivities of (0.951 ± 0.138) × 10 -2 S/cm at -30 °C and (7.32 ± 0.37) × 10 -2 S/cm at 160 °C. Additionally, the fine proton conductivity stability is demonstrated by the proton conductivity in the long-term test and the cooling/heating cycle test, such as 1.67 × 10 -2 S/cm at -30 °C (after 1000 h), 4.52 × 10 -2 S/cm at 30 °C (after 810 h), 1.12 × 10 -2 S/cm at -30 °C, and 1.01 × 10 -1 S/cm at 30 °C in the cooling/heating process (5 cycles). The single fuel cell possesses an open-circuit voltage of 0.886 V and a peak power density of 0.508 W/cm 2 at 130 °C.

Proteolytic targeting chimera (PROTAC) represent an advanced strategy for targeting undruggable proteins, and the molecular warheads targeting E3 ligases play a crucial role. Recently, we explored an alkenyl oxindole warhead targeting the E3 ligase DCAF11 and sought to validate its potential. In this study, we synthesized a range of BRD4 PROTACs ( 8a - 8o , 14a-14f , 22a-22m ) with modified alkenyl oxindole warheads and developed a high-throughput screening system based on high-content imaging. We identified L134 ( 22a ) as a potent BRD4 degrader, achieving BRD4 degradation ( D max > 98%, DC 50 = 7.36 nM) and demonstrating antitumor activity. Mechanically, BRD4 degradation by L134 was mediated through the ubiquitin-proteasome system in a DCAF11-dependent manner. Therefore, this study provides a rapid screening method for effective PROTACs and highlights the PROTAC L134 based on alkenyl oxindole-DCAF11 pair as a promising candidate for treating BRD4-driven cancers.

Alloy-type anodes used in magnesium ion batteries (MIBs) have garnered significant attention in light of their substantial theoretical specific capacities and possible matchability with conventional electrolytes. However, the major challenges for alloy-type anodes are the sluggish transport kinetics as well as severe volume variations during the discharge/charge processes. Herein, we present a strategy for phase-structure modulation to fabricate a self-supporting In-Bi film through straightforward magnetron sputtering. In comparison to the single-phase In and Bi electrodes, the biphase InBi/Bi electrode displays markedly enhanced rate and cycling performance, with the discharge capacities of 303.1/292.6 mAh g -1 after 550/500 cycles at 200/2000 mA g -1 , respectively. The exceptional Mg storage capability of the sputtered InBi/Bi electrode could be ascribed to the favorable two-phase configuration and increased phase boundaries, effectively accommodating volume expansion and accelerating Mg 2+ ion transport. More importantly, the (de)magnesiation mechanism of InBi/Bi for MIBs was elucidated through operando X-ray diffraction.

Developing fouling-resistant materials is of paramount interest in marine industries and biomedical applications. In this work, we studied the interfacial hydration and surface-protein interactions of the amphiphilic brush surface functionalized with hybrid hydrophilic trimethylamine N -oxide (TMAO) and hydrophobic pentafluoroethyl groups using a combination of atomistic molecular dynamics simulations and free-energy computations. Our results show that while the interfacial hydration density of the amphiphilic surface slightly decreases with the introduction of small fluorocarbons compared to that of the pure TMAO-functionalized surface, the amphiphilic surface remains relatively strong in resisting protein adsorption. The nanosized clustering of hydrophobic fluorine atoms on the top of the amphiphilic brush surface introduces weak protein adsorption; however, due to the strong interfacial hydration and weak hydrophobic interaction, the amphiphilic surface exhibits sufficient antibiofouling activities. Our fundamental studies will be critical for the discovery of marine fouling-resistant coating surfaces.

The successful application of mRNA vaccines in preventing and treating infectious diseases highlights their potential as therapeutic vaccines for cancer treatment. However, unlike infectious diseases, effective antitumor therapy, particularly for solid tumors, necessitates the activation of more powerful cellular and humoral immunity to achieve clinical efficacy. Here, we report a spleen-targeted mRNA vaccine (Mn@mRNA-LNP) designed to deliver tumor antigen-encoding mRNA and manganese adjuvant (Mn 2+ ) simultaneously to dendritic cells (DCs) in the spleen. This delivery system promotes DC maturation and surface antigen presentation and stimulates the production of cytotoxic T cells. Additionally, Mn 2+ codelivered in the system serves as a safe and effective immune adjuvant, activating the stimulator of interferon genes (STING) signaling pathway and promoting the secretion of type I interferon, further enhancing the antigen-specific T cell responses. Mn@mRNA-LNP effectively inhibits tumor progression in established melanoma and colon tumor models as well as in a model of tumor recurrence after resection. Notably, the combination of Mn@mRNA-LNP with immune checkpoint inhibitors further enhances complete tumor suppression and prolonged the overall survival in mice. Overall, this "All-in-One" mRNA vaccine significantly boosts antitumor immunity responses by improving spleen targeting and immune activation, providing an attractive strategy for the future clinical translation of therapeutic mRNA vaccines.

Ambient urea synthesis via C-N coupling from CO 2 and nitrate reduction offers an attractive alternative to the Bosch-Meiser route, but it is hindered by the lack of efficient catalysts. Herein, we report that Fe-doped InOOH nanosheets effectively catalyze the coreduction of CO 2 and nitrate, giving a high Faradaic Efficiency of 26.9%, a yield rate of 980.6 μg h -1 mg cat. -1 , and a good durability. Theoretical calculations further elucidate that iron dopants can tailor the reactivity of the In site, facilitating the hydrogenation of the key *CO 2 NH 2 intermediate and suppressing the hydrogen production with a higher energy barrier.

Microwave thermotherapy (MT) is a clinical local tumor ablation modality, but its applications are limited by its therapeutic efficacy and safety. Therefore, developing sensitizers to optimize the outcomes of MT is in demand in clinical practice. Herein, we engineered a special nanoframework (i.e., FdMI) based on a fucoidan-decorated zirconium metal-organic framework incorporating manganese ions and liquid physisorption for microwave tumor ablation. The monodisperse nanoframework exhibited both microwave thermal effects and microwave dynamic effects, which could effectively kill cancer cells by efficient intracellular drug delivery. Through fucoidan-mediated targeting of P-selectin in the tumor microenvironment (TME), the FdMI effectively accumulated in tumor regions, leading to significant eradication of orthotropic triple-negative breast cancer (TNBC) and aggressive Hepa1-6 liver tumors by the synergistic effects of microwave thermotherapy/dynamic therapy (MT/MDT). The eradication of primary tumors could activate systemic immune responses, which effectively inhibited distant TNBC tumors and lung metastasis of Hepa1-6 liver tumors, respectively. This work not only engineered nanoparticle sensitizers for tumor-targeted synergistic MT/MDT but also demonstrated that nanocarrier-based microwave tumor ablation could stimulate antitumor immunity to effectively inhibit distant and metastatic tumors, demonstrating the high potential for effectively managing advanced malignant tumors.

Water-enabled electricity generation (WEG), which harvests energy from the natural water cycle, is a novel strategy for producing green electricity. Taking advantage of the ion sieving effect based on evaporation-induced water flows in charged nanopores, various WEG devices have been developed. Here, we report that a carbonized mushroom produces a record-high current output of up to 96.7 μA, which is attributed to a unique ion adsorption effect combined with an ion sieving effect. Specifically, the natural gradient potential from root to cap in a mushroom caused by tissue differentiation adsorbs different ions, enhancing the traditional ion sieving current. In synergy with the two effects, the mushroom can operate under a broad range of concentrations (0 to 0.6 mol L -1 ) and represents significant improvements in current, duration, and total charge transfer. These findings reveal the hidden talent of mushrooms as natural materials for WEG, providing inspiration for the development of high-performance WEG devices.

While experimental realization of multiple charge-density waves (CDWs) has been ascribed to monolayer 1T-NbTe 2 , their atomic structures are still largely unclear, preventing a deep understanding of their novel electronic structures. Here, comparing first-principles-calculated orbital textures with reported STM measurements, we successfully identify multiple CDWs in monolayer NbTe 2 . Surprisingly, we reveal that both 1T/1H phases could exist in monolayer NbTe 2 , which was incognizant before. Particularly, we find that the experimentally observed 4 × 1 and 4 × 4 CDWs could be attributed to 1H stacking, while the observed 19 × 19 phase could possess 1T stacking. The existence of 1T/1H phases results in competition between CDW, spin-density wave (SDW), and ferromagnetism in 1H stacking under an external field and results in CDW-induced quantum phase transitions from a Kramers-Weyl fermion to a topological insulator in 1T stacking. Our study suggests NbTe 2 as an exotic platform to investigate the interplay between CDW, SDW, and topological phases, which are largely unexplored in current experiments.

Over the last 30 years, despite considerable research and endeavors aimed at harnessing aptamers as pharmaceutical molecules, the progress in developing aptamer-based drugs has been falling short of expectations. Sequential steps of affinity molecule acquisition and functional screening are typically required for discovering affinity-based macromolecule therapeutics, which can be time-consuming and limiting in candidate selection. Additionally, aptamers often necessitate tedious postselection modifications to overcome pharmacokinetic limitations, which usually impede the binding affinity. Herein, we propose a novel in vitro screening platform termed Functional Aptamers in vitro Evolution (FAIVE), which integrates affinity molecule acquisition with functional screening and introduces chemical diversity during the process. This platform aims to rapidly generate functional aptamers capable of binding to target proteins and regulating their functions. Illustrated by targeting intranuclear RNA-protein interactions involving HIV-1 Tat protein and TAR RNA, FAIVE demonstrates a selection of functional aptamers with significant intracellular blocking effects. The study also explores lipid nanoparticle delivery systems to enhance intracellular delivery efficiency, expanding aptamer targeting potential to broader intracellular and intranuclear domains. This study emphasizes the potential of FAIVE to expedite the development of aptamer-based drugs and facilitate the creation of more versatile and effective therapeutics.

Macrocyclic peptides are promising scaffolds for the covalent ligand discovery. However, platforms enabling the direct identification of covalent macrocyclic ligands in a high-throughput manner are limited. In this study, we present an mRNA display platform allowing selection of covalent macrocyclic inhibitors using 1,3-dibromoacetone-vinyl sulfone (DBA-VS). Testcase selections on TEV protease resulted in potent covalent inhibitors with diverse cyclic structures, among which cTEV6-2, a macrocyclic peptide with a unique C-terminal cyclization, emerged as the most potent covalent inhibitor of TEV protease described to-date. This study outlines the workflow for integrating chemical functionalization─installation of a covalent warhead─with mRNA display and showcases its application in targeted covalent ligand discovery.

A metal-organic frameworks (MOFs)-in-MOF nanovehicle (160 nm), which was constructed with newly prepared ultrasmall Cu(I)Cu(II)-BTC MOFs (UCMs, 2.95 nm) loaded with doxorubicin (DOX) and a nuclear localization signal (NLS) peptide as multicores (UCMDNs) and ZIF-8 as the shell MOF, was proposed to cross layers of biological barriers with adaptive size evolution capacity for achieving efficient nucleus-targeted drug delivery. It first enhanced tumor tissue penetration through its larger nanosize effect. Then the acidic tumor environment made the ZIF-8 shell degrade, releasing small-sized UCMDNs to enter into the cell and into the nucleus under the guidance of NLS. Furthermore, due to the distinct surface structural characteristics of UCMs, UCMDNs remained stable in the cytoplasm and collapsed in the nucleus due to the DOX-DNA interaction to deliver DOX precisely. It showed superior performance in the nucleus-directed delivery of DOX (delivery efficiency up to 56.7%) and a high tumor growth inhibition rate (96.4%), offering promising prospects in tumor chemotherapy.

Investigating the habitability of ocean worlds is a priority of current and future NASA missions. The Europa Clipper mission will conduct approximately 50 flybys of Jupiter's moon Europa, returning a detailed portrait of its interior from the synthesis of data from its instrument suite. The magnetometer on board has the capability of decoupling Europa's induced magnetic field to high precision, and when these data are inverted, the electrical conductivity profile from the electrically conducting subsurface salty ocean may be constrained. To optimize the interpretation of magnetic induction data near ocean worlds and constrain salinity from electrical conductivity, accurate laboratory electrical conductivity data are needed under the conditions expected in their subsurface oceans. At the high-pressure, low-temperature (HPLT) conditions of icy worlds, comprehensive conductivity data sets are sparse or absent from either laboratory data or simulations. We conducted molecular dynamics simulations of candidate ocean compositions of aqueous NaCl under HPLT conditions at multiple concentrations. Our results predict electrical conductivity as a function of temperature, pressure, and composition, showing a decrease in conductivity as the pressure increases deeper into the interior of an icy moon. These data can guide laboratory experiments at conditions relevant to icy moons and can be used in tandem to forward-model the magnetic induction signals at ocean worlds and compare with future spacecraft data. We discuss implications for the Europa Clipper mission., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

The development of catalysts with high photon utilization efficiency is crucial for enhancing the catalytic performance of photocatalysts. Graphitic carbon nitride (g-C 3 N 4 ) is a prominent material in the field of photocatalysis. However, it still exhibits drawbacks such as low utilization of visible light and severe recombination of photogenerated carriers. To address these issues, this study employs MoS 2 nanotubes (NTs) as cocatalysts and constructs MoS 2 NTs/g-C 3 N 4 . The MoS 2 NTs/g-C 3 N 4 exhibits a significant cavity enhancement effect through multiple light reflections. This results in a broad spectral absorption range and high photon utilization efficiency, while also reducing the recombination of photogenerated carriers. The photocatalyst demonstrates outstanding performance in both photocatalytic hydrogen production and photodegradation of organic pollutants. Specifically, the hydrogen production rate is 1921 μmol·g -1 ·h -1 , which is approximately 2.4 times that of g-C 3 N 4 . Furthermore, the photodegradation rate of Rhodamine B reaches 98.6% within 30 min, which is approximately three times higher than that of g-C 3 N 4 . Free radical capture experiments confirm that holes (h + ) are the primary active species in photodegradation. A plausible photocatalytic mechanism for the catalyst is proposed. This study provides valuable insights into the development of heterojunction photocatalysts with high photon utilization efficiency.

Enzymes catalyze almost all material conversion processes within living organisms, yet their natural evolution remains unobserved. Short peptides, derived from proteins and featuring active sites, have emerged as promising building blocks for constructing bioactive supramolecular materials that mimic native proteins through self-assembly. Herein, we employ histidine-containing isomeric tetrapeptides KHFF, HKFF, KFHF, HFKF, FKHF, and FHKF to craft supramolecular self-assemblies, aiming to explore the sequence-activity landscapes of enzyme evolution. Our investigations reveal the profound impact of peptide sequence variations on both assembly behavior and catalytic activity as hydrolytic simulation enzymes. During self-assembly, a delicate balance of multiple intermolecular interactions, particularly hydrogen bonding and aromatic-aromatic interactions, influences nanostructure formation, yielding various morphologies (e.g., nanofibers, nanospheres, and nanodiscs). Furthermore, the analysis of the structure-activity relationship demonstrates a strong correlation between the distribution of the His active site on the nanostructures and the formation of the catalytic microenvironment. This investigation of the sequence-structure-activity paradigm reflects how natural enzymes enhance catalytic activity by adjusting the primary structure during evolution, promoting fundamental research related to enzyme evolutionary processes.

Cancer vaccines with the ability to elicit tumor-specific immune responses have attracted significant interest in cancer immunotherapy. A key challenge for effective cancer vaccines is the spatiotemporal codelivery of antigens and adjuvants. Herein, we synthesized a copolymer library containing nine poly(ethylene glycol) methyl ether methacrylate- co -butyl methacrylate- co -2-(azepan-1-yl)ethyl methacrylate (PEGMA- co -BMA- co -C7AMA) graft copolymers with designed proportions of different components to regulate their properties. Among these polymers, C-25, with a C7AMA:BMA ratio at 1.5:1 and PEG wt % of 25%, was screened as the most effective nanovaccine carrier with enhanced ability to induce mouse bone marrow-derived dendritic cell (BMDC) maturation. Additionally, RNA-sequencing (RNA-Seq) analysis revealed that C-25 could activate dendritic cells (DCs) through multisignaling pathways to trigger potent immune effects. Then, the screened C-25 was used to encapsulate the model peptide antigen, OVA 257-280 , to form nanovaccine C-25/OVA 257-280 . It was found that the C-25/OVA 257-280 nanovaccine could effectively facilitate DC maturation and antigen cross-presentation without any other additional adjuvant and exhibited excellent prophylactic efficacy in the B16F10-OVA tumor model. Moreover, in combination with antiprogrammed cell death protein-ligand 1 (anti-PD-L1), the C-25/OVA 257-280 nanovaccine could significantly delay the growth of pre-existing tumors. Therefore, this work developed a minimalist nanovaccine with a simple formulation and high efficiency in activating tumor-specific immune responses, showing great potential for further application in cancer immunotherapy.

Vanadium oxides are excellent cathode materials with large storage capacities for aqueous zinc-ion batteries, but their further development has been hampered by their low electronic conductivity and slow Zn 2+ diffusion. Here, an electrochemically induced phase transformation strategy is proposed to mitigate and overcome these barriers. In situ X-ray diffraction analysis confirms the complete transformation of tunnel-like structural V 6 O 13 into layered V 5 O 12 ·6H 2 O during the initial electrochemical charging process. Theoretical calculations reveal that the phase transformation is crucial to reducing the Zn 2+ migration energy barrier and facilitating fast charge storage kinetics. The calculated band structures indicate that the bandgap of V 5 O 12 ·6H 2 O (0.0006 eV) is lower than that of V 6 O 13 (0.5010 eV), which enhanced the excitation of charge carriers to the conduction band, favoring electron transfer in redox reactions. As a result, the transformed V 5 O 12 ·6H 2 O delivers a high capacity of 609 mA h g -1 at 0.1 A g -1 , superior rate performance (300 mA h g -1 at 20 A g -1 ), fast-charging capability (<7 min charging for 465 mA h g -1 ), and excellent cycling stability with a reversible capacity of 346 mA h g -1 at 5 A g -1 after 5000 cycles.

This study investigated differences in absorption and metabolism between 1,3-oleate-2-palmitate glycerol (OPO) and 1-oleate-2-palmitate-3-linoleate glycerol (OPL) using C57BL/6J mice. OPL was associated with higher postprandial plasma total triacylglycerol (TG), low-density lipoprotein cholesterol (LDL-C) concentrations, and the ratio of LDL-C to high-density lipoprotein cholesterol (HDL-C) compared to those of OPO ( p > 0.05). OPO significantly increased postprandial oleic acid (OA) concentrations compared to OPL over the entire monitoring period ( p < 0.05), while OPL significantly elevated linoleic acid (LA) levels compared to OPO ( p < 0.05). After 1 month of feeding, the mice in both OPO and OPL groups showed lower final weight, weight gain, and liver TG, LDL-C, and LDL/HDL concentrations compared to the control (soybean oil) group. Lipidomics results showed that OPO increased the biosynthesis of very long-chain fatty acids and decreased the abundance of AcCa (16:1), AcCa (18:2), AcCa (18:1), AcCa (16:0), CarE (16:0), and CarE (16:1) relative to OPL. These lipid metabolites were positively correlated with liver TG, LDL-C, and LDL/HDL levels and negatively related to peroxisome proliferator-activated receptors α (PPARα) and acyl-CoA oxidase (ACOX1) expression. This study showed differences in physiologic functions between OPO and OPL and provided support for the future application of OPL in infant formula.

Deoxynivalenol (DON), one of the most polluted mycotoxins in the environment and food, has been proven to have strong embryonic and reproductive toxicities. However, the effects of DON on placental impairment and effective interventions are still unclear. This study investigated the effect of β-carotene on placental functional impairment and its underlying molecular mechanism under DON exposure. Adverse pregnancy outcomes were caused by intraperitoneal injection of DON from 13.5 to 15.5 days of gestation in mice, resulting in higher enrichment of DON in placenta than in other tissue samples. Interestingly, 0.1% β-carotene dietary supplementation could significantly alleviate DON-induced pregnancy outcomes. Additionally, in vivo and in vitro placental barrier models demonstrated the association of DON-induced placental function impairment with placental permeability barrier disruption, angiogenesis impairment, and oxidative stress induction. Moreover, β-carotene regulated DON-induced placental toxicity by activating the expressions of claudin 1, zonula occludens -1, and vascular endothelial growth factor-A through retinoic acid-peroxisome proliferator-activated receptor α signaling.

Intranasal vaccines can induce protective immune responses at the mucosa surface entrance, preventing the invasion of respiratory pathogens. However, the nasal barrier remains a major challenge in the development of intranasal vaccines. Herein, a transmucosal nanovaccine based on cationic fluorocarbon modified chitosan (FCS) is developed to induce mucosal immunity. In our system, FCS can self-assemble with the model antigen ovalbumin and TLR9 agonist CpG, effectively promoting the maturation and cross-presentation of dendritic cells. More importantly, it can enhance the production of secretory immunoglobin A (sIgA) at mucosal surfaces for those intranasally vaccinated mice, which in the meantime showed effective production of immunoglobulin G (IgG) systemically. As a proof-of-concept study, such a mucosal vaccine inhibits ovalbumin-expressing B16-OVA melanoma, especially its lung metastases. Our work presents a unique intranasal delivery system to deliver antigen across mucosal epithelia and promote mucosal and systemic immunity.

In-situ exsolution type perovskites as solid oxide fuel cell (SOFCs) anode materials have received widespread attention because of their excellent catalytic activity. In this study, excessive NiO is introduced to the Sr 2 V 0.4 Fe 0.9 Mo 0.7 O 6-δ (SVFMO) perovskite with the B-site excess design, and in-situ growth of FeNi 3 alloy nanoparticles is induced in the reducing atmosphere to form the Sr 2 V 0.4 Fe 0.9 Mo 0.7 O 6-δ -Ni 0.4 (SVFMO-Ni 0.4 ) composite anode. Here, with H 2 or CH 4 as SOFCs fuel gas, the formation of FeNi 3 nanoparticles further enhances the catalytic ability. Compared with SVFMO, the maximum power density ( P max ) of Sr 2 V 0.4 Fe 0.9 Mo 0.7 O 6-δ -Ni 0.4 (SVFMO-Ni 0.4 ) increases from 538 to 828 mW cm -2 at 850 °C with hydrogen as the fuel gas, and the total polarization resistance ( R P ) decreases from 0.23 to 0.17 Ω cm 2 . In addition, the long-term operational stability of the SVFMO-Ni 0.4 anode shows no apparent performance degradation for more than 300 h. Compared with SVFMO, the P max of SVFMO-Ni 0.4 increases from 138 to 464 mW cm -2 with methane as fuel gas, and the R P decreases from 1.21 to 0.29 Ω cm 2 .

Titanium alloy porous scaffolds possess excellent mechanical properties and biocompatibility, making them promising for applications in bone tissue engineering. The integration of triply periodic minimal surface (TPMS) with porous scaffolds provides a structural resemblance to the trabecular and cortical bone structures of natural bone tissue, effectively reducing stress-shielding effects, enabling the scaffold to withstand complex stress environments, and facilitating nutrient transport. In this study, we designed fused porous scaffolds based on the Gyroid and Diamond units within TPMS and fabricated samples using selective laser melting technology. The effects of the rotation direction and angle of the inner-layer G unit on the elastic modulus of the fused TPMS porous scaffold were investigated through quasi-static compression experiments. Furthermore, the influence of the rotation direction and angle of the inner-layer G unit on the permeability, pressure, and flow velocity of the fused TPMS porous scaffold structure was studied using computational fluid dynamics (CFD) based on the Navier-Stokes model. The quasi-static compression experiment results demonstrated that the yield strength of the fused TPMS porous scaffold ranged from 367.741 to 419.354 MPa, and the elastic modulus ranged from 10.617 to 11.252 GPa, exhibiting stable mechanical performance in different loading directions. The CFD simulation results indicated that the permeability of the fused TPMS porous scaffold model ranged from 5.70015 × 10 -8 to 6.33725 × 10 -8 m 2 . It can be observed that the fused porous scaffold meets the requirements of the complex stress-bearing demands of skeletal structures and complies with the permeability requirements of human bone tissue.

In today's information age, high performance nonvolatile memory devices have become extremely important. Despite their potential, existing devices suffer from limitations, such as low operation speed, low memory capacity, short retention time, and a complex preparation process. To overcome these limitations, advanced memory designs are required to improve speed, memory capacity, and retention time and reduce the number of preparation steps. Here, we present a nonvolatile floating-gate-like memory device based on a transistor that uses the polarization effect of ferroelectric material PZT (Pb[Zr 0.2 Ti 0.8 ]O 3 ) for regulating tunneling electrons for charging and discharging the MoS 2 channel layer. The transistor is defined as a polarized tunneling transistor (PTT) and does not require a tunnel layer or a floating-gate layer. The PTT demonstrates an ultrafast programming/erasing speed of 25/20 ns and a response time of 120/105 ns, which is comparable to the ultrafast flash memories based on van der Waals heterostructures. Additionally, the PTT has a high extinction ratio of 10 4 , a long retention time of 10 years, and a simple fabrication process. Our research provides future guidelines for the development of the next generation of ultrafast nonvolatile memory devices.

The layered transition metal oxides (Na x TMO 2 ) are the most attractive cathode options for the rechargeable sodium-ion batteries (SIBs) owing to their high specific capacity, outstanding sodium desorption ability, and high average operating voltage. However, the kinetic behaviors corresponding to complex and prominent phase transitions are still perplexing. Here, we investigate the detailed electrochemical kinetic characteristics of the NaNi 1/3 Fe 1/3 Mn 1/3 O 2 electrode by electrochemical impedance spectroscopy (EIS) in three-electrode configurations assistance with the distribution of relaxation times (DRT) and trusted equivalent circuit models numerical analysis. The complex and prominent phase transformations evolution of O3-P3-O3' in the charge process and O3'-P3'-O3 during the discharge process are reflected at different degrees of frequencies and potentials, and significant contributions for the charge transfer step are established on this basis. As the charge and discharge proceed, the influence on charge transfer process by phase transform will be weak, however, which still has some expression and can be caught by EIS assistance with DRT. Additionally, a diagrammatic model for Na + extraction/insertion is established to illustrate the physicochemical reaction mechanism in the NaNi 1/3 Fe 1/3 Mn 1/3 O 2 electrode. The results definitely provide certain scientific thoughts and guiding principles for the commercialization of Na x TMO 2 in SIBs.

Biomimetic structures to fabricate bioelectronic interfaces that allow sensors to electrically communicate with electrodes have potential applications in the development of biosensors. Herein, inspired by the structure feature of nitric oxide (NO) sensory protein, we constructed a biomimetically catalytic center, the histamine coordinated iron phthalocyanine (FePc), for efficient and sensitive detection of NO. In specific, NO is recognized by axial tethered FePc, and the oxidative signal of NO on FePc is converted into output signal through electrocatalytic oxidation. Based on the fabricated catalytic structure on the carbon fiber electrode, on one hand, the macrocyclic π system of FePc enabled a rapid redox process, which facilitates electron transfer, thereby greatly improving sensitivity. On the other hand, by coordination with histamine on the electrode surface, FePc can enhance the electrochemical oxidation activity toward NO and promote catalytic detection, which have been revealed by electrochemical characterizations and density functional theory theoretical calculations. The designed electrochemical microsensor exhibits a low limit of detection (0.03 nM) and shows a wide detection range (0.1 nM-2 μM). In addition, the electrochemical microsensor has been successfully used for real-time monitoring of NO release by live cells. So, this work shows a new strategy for the design of bio-inspired electrochemical microsensors that may provide a potential analytical tool for tracing biological signal molecules with enzyme-free biomimetically catalytic centers.

Carcinoembryonic antigen (CEA) is a recognized biomarker for lung cancer and can be used for early detection. However, the clinical value of CEA is not fully realized due to the rigorous requirement for high-sensitivity and wide-range detection methods. Field-effect transistor (FET) biosensors, as one of the potentially powerful platforms, may detect CEA with a significantly higher sensitivity than conventional clinical testing equipment, while their sensitivity and detection range for CEA are far below the requirement for early detection. Here, we construct a floating gate FET biosensor to detect CEA based on a semiconducting carbon nanotube (CNT) film combined with an undulating yttrium oxide (Y 2 O 3 ) dielectric layer as the biosensing interface. Utilizing an undulating biosensing interface, the proposed device showed a wider detection range and optimized sensitivity and detection limit, which benefited from an increase of probe-binding sites on the sensing interface and an increase of electric double-layer capacitance, respectively. The outcomes of analytical studies confirm that the undulating Y 2 O 3 provided the desired biosensing surface for probe immobilization and performance optimization of a CNT-FET biosensor toward CEA including a wide detection range from 1 fg/mL to 1 ng/mL, good linearity, and high sensitivity of 72 ag/mL. More crucially, the sensing platform can function normally in the complicated environment of fetal bovine serum, indicating its great promise for early lung cancer screening.

Digitaria ciliaris var. chrysoblephara is a xerophytic weed severely invading rice fields along with the application of rice mechanical direct seeding technology in China. This study identified one resistant population (M5) with an Ile-1781-Leu substitution in ACCase1 showing broad-spectrum resistance to three chemical classes of ACCase-inhibiting herbicides, including metamifop, cyhalofop-butyl, fenoxaprop- p -ethyl, haloxyfop- p -methyl, clethodim, sethoxydim, and pinoxaden. The other two populations, M2 and M4, without any resistance-responsible mutations, only exhibited resistance to aryloxyphenoxypropionate (APP) herbicides cyhalofop-butyl and fenoxaprop- p -ethyl. Pre-treatment with the cytochrome P450 monooxygenase (P450) inhibitor PBO significantly reduced the cyhalofop-butyl resistance by 43% in the M2 population. Pre-emergence weed control with soil-applied herbicides, such as pretilachlor, pendimethalin, and oxadiazon, can effectively inhibit the germination and growth of D. ciliaris var. chrysoblephara . The present study reported a xerophytic weed species invading rice fields featuring broad-spectrum resistance to ACCase-inhibiting herbicides as a result of Ile-1781-Leu mutation of ACCase . Both target- and P450-involved non-target-site mechanisms may be contributing to resistance in D. ciliaris var. chrysoblephara species.

The heteroepitaxy of high-quality aluminum nitride (AlN) with low stress is essential for the development of energy-efficient deep ultraviolet light-emitting diodes (DUV-LEDs). In this work, we realize that quasi-van der Waals epitaxy growth of a stress-released AlN film with low dislocation density on hexagonal boron nitride (h-BN)/sapphire suffered from high-temperature annealing (HTA) treatment and demonstrate its application in a DUV-LED. It is revealed that HTA effectively improves the crystalline quality and surface morphology of monolayer h-BN. Guided by first-principles calculations, we demonstrate that h-BN can enhance lateral migration of Al atoms due to the ability to lower the surface migration barrier (less than 0.14 eV), resulting in the rapid coalescence of the AlN film. The HTA h-BN is also proved to be efficient in reducing the dislocation density and releasing the large strain in the AlN epilayer. Based on the low-stress and high-quality AlN film on HTA h-BN, the as-fabricated 290 nm DUV-LED exhibits 80% luminescence enhancement compared to that without h-BN, as well as good reliability with a negligible wavelength shift under high current. These findings broaden the applications of h-BN in favor of III-nitride and provide an opportunity for further developing DUV optoelectronic devices on large mismatched heterogeneous substrates.

During the cell viability detection process inside a microfluidic chip, the more uniform the distribution of medium flow rates, the higher the accuracy of detection results. In order to achieve this goal, a multichannel microfluidic chip with uniform distribution of medium flow rates has been successfully designed. The multichannel microfluidic chip is designed with cell injection channels, vascular network-shaped medium injection channels, buffer zones, and a culture chamber. The medium flow rates inside culture chambers of the multichannel microfluidic chip and the common single-channel microfluidic chip are compared by COMSOL Multiphysics software and particle velocimetry experiment. The simulation and experimental results show that the medium flow rate distribution inside the culture chamber of the multichannel microfluidic chip is more uniform and changes more smoothly. When the medium perfusion flow rate is 0.5 μL/min, the maximum flow rate difference inside the culture chamber of the single-channel microfluidic chip is more than 13 times that of the multichannel microfluidic chip. Therefore, the multichannel microfluidic chip can ensure a uniform supply of medium inside the culture chamber, which is beneficial to improve the accuracy of cell viability detection.

The crossing of blood-brain barrier (BBB) is essential for glioblastoma (GBM) therapy, and homotypic targeting is an effective strategy to achieve BBB crossing. In this work, GBM patient-derived tumor cell membrane (GBM-PDTCM) is prepared to cloak gold nanorods (AuNRs). Relying on the high homology of the GBM-PDTCM to the brain cell membrane, GBM-PDTCM@AuNRs realize efficient BBB crossing and selective GBM targeting. Meanwhile, owing to the functionalization of Raman reporter and lipophilic fluorophore, GBM-PDTCM@AuNRs are able to generate fluorescence and Raman signals at GBM lesion, and almost all tumor can be precisely resected in 15 min by the guidance of dual signals, ameliorating the surgical treatment for advanced GBM. In addition, photothermal therapy for orthotopic xenograft mice is accomplished by intravenous injection of GBM-PDTCM@AuNRs, doubling the median survival time of the mice, which improves the nonsurgical treatment for early GBM. Therefore, benefiting from homotypic membrane-enhanced BBB crossing and GBM targeting, all-stage GBM can be treated with GBM-PDTCM@AuNRs in distinct ways, providing an alternative idea for the therapy of tumor in the brain.

The reversibility and cyclability of aqueous zinc-ion batteries (ZIBs) are largely determined by the stabilization of the Zn anode. Therefore, a stable anode/electrolyte interface capable of inhibiting dendrites and side reactions is crucial for high-performing ZIBs. In this study, we investigated the adsorption of 1,4-dioxane (DX) to promote the exposure of Zn (002) facets and prevent dendrite growth. DX appears to reside at the interface and suppress the detrimental side reactions. ZIBs with the addition of DX demonstrated a long-term cycling stability of 1000 h in harsh conditions of 10 mA cm -2 with an ultrahigh cumulative plated capacity of 5 Ah cm -2 and shows a good reversibility with an average Coulombic efficiency of 99.7%. The Zn//NH 4 V 4 O 10 full battery with DX achieves a high specific capacity (202 mAh g -1 at 5 A g -1 ) and capacity retention (90.6% after 5000 cycles), much better than that of ZIBs with the pristine ZnSO 4 electrolyte. By selectively adjusting the Zn 2+ deposition rate on the crystal facets with adsorbed molecules, this work provides a promising modulation strategy at the molecular level for high-performing Zn anodes and can potentially be applied to other metal anodes suffering from instability and irreversibility.

Integrating different reaction sites offers new prospects to address the difficulties in single-atom catalysis, but the precise regulation of active sites at the atomic level remains challenging. Here, we demonstrate a sodium-directed photon-induced assembly (SPA) strategy for boosting the atomic utilization efficiency of single-atom catalysts (SACs) by constructing multifarious Au sites on TiO 2 substrate. Na + was employed as the crucial cement to direct Au single atoms onto TiO 2 , while the light-induced electron transfer from excited TiO 2 to Au(Na + ) ensembles contributed to the self-assembly formation of Au nanoclusters. The synergism between plasmonic near-field and Schottky junction enabled the cascade electron transfer for charge separation, which was further enhanced by oxygen vacancies in TiO 2 . Our dual-site photocatalysts exhibited a nearly 2 orders of magnitude improvement in the hydrogen evolution activity under simulated solar light, with a striking turnover frequency (TOF) value of 1533 h -1 that exceeded other Au/TiO 2 -based photocatalysts reported. Our SPA strategy can be easily extended to prepare a wide range of metal-coupled nanostructures with enhanced performance for diverse catalytic reactions. Thus, this study provides a well-defined platform to extend the boundaries of SACs for multisite catalysis through harnessing metal-support interactions.

Leukocyte adhesion deficiency-1 (LAD-1) disorder is a severe immunodeficiency syndrome caused by deficiency or mutation of β2 integrin. The phosphorylation on threonine 758 of β2 integrin acts as a molecular switch inhibiting the binding of filamin. However, the switch mechanism of site-specific phosphorylation at the atom level is still poorly understood. To resolve the regulation mechanism, all-atom molecular dynamics simulation and Markov state model were used to study the dynamic regulation pathway of phosphorylation. Wild type system possessed lower binding free energy and fewer number of states than the phosphorylated system. Both systems underwent local disorder-to-order conformation conversion when achieving steady states. To reach steady states, wild type adopted less number of transition paths/shortest path according to the transition path theory than the phosphorylated system. The underlying phosphorylated regulation pathway was from P1 to P0 and then P4 state, and the main driving force should be hydrogen bond and hydrophobic interaction disturbing the secondary structure of phosphorylated states. These studies will shed light on the pathogenesis of LAD-1 disease and lay a foundation for drug development.

Exploring highly efficient microwave absorption (MA) materials with a facile preparation method is of great significance for tackling electromagnetic pollution and remains a challenge. Herein, ternary MoO 2 /Mo 2 C/Mo 2 N composites with porous structures are fabricated by a simple precursor pyrolysis process. The unique structure and multiple components, which could generate sufficient heterogeneous interfaces, are conducive to improve impedance matching, trigger polarization loss, and strengthen conduction loss. Profiting from the synergistic effect of multiple dissipation mechanisms, the composites exhibit exceedingly good MA performance. The minimum reflection loss value reaches -38.0 dB at 10.4 GHz when the thickness is 2.0 mm, and the maximum effective absorbing bandwidth is 4.11 GHz ranged from 12.41 to 16.52 GHz when the thickness is 1.5 mm. These strategies pave opportunities for rational design of Mo-related composites for high-efficiency electromagnetic-wave absorption performance.

The iron-based superconductors are an ideal platform to reveal the enigma of the unconventional superconductivity and potential topological superconductivity. Among them, the monolayer Fe(Se,Te)/SrTiO 3 (001), which is proposed to be topological nontrivial, shows interface-enhanced high-temperature superconductivity in the two-dimensional limit. However, the experimental studies on the superconducting pairing mechanism of monolayer Fe(Se,Te) films are still limited. Here, by measuring the quasiparticle interference in monolayer Fe(Se,Te)/SrTiO 3 (001), we report the observation of the anisotropic structure of the large superconducting gap and the sign change of the superconducting gap on different electron pockets. The results are well consistent with the "bonding-antibonding" s ± -wave pairing symmetry driven by spin fluctuations in conjunction with spin-orbit coupling. Our work is of basic significance not only for a unified superconducting formalism in the iron-based superconductors, but also for understanding of topological superconductivity in high-temperature superconductors.