Development of UHPLC-Q-Exactive Orbitrap/MS Technique for Determination of Proanthocyanidins (PAs) Monomer Composition Content in Persimmon.

The main units of persimmon proanthocyanidins (PAs) are composed of flavan-3-ols including epigallocatechin gallate (EGCG) and gallocatechin gallate (GCG). Precise quantification of GCG is challenging due to its trace amounts in persimmon. In this study, to establish the optimal UHPLC-Q-Exactive Orbitrap/MS technique for the determination of PAs monomer composition in persimmon fruit flesh of different astringency types, mass spectrometry and chromatographic conditions were optimized. The results showed that when operating in negative ion mode, using a T3 chromatographic column (a type of C18 column with high-strength silica), acetonitrile as the organic phase, a 0.1% mobile phase acid content, and a mobile phase flow rate of 0.2 mL/min, the chromatographic peak shape and resolution of the PAs monomer composition improved. Additionally, there was no tailing phenomenon observed in the chromatographic peaks. At the same time, the intra-day and inter-day precision, stability, and recovery of the procedure were good. The relative standard deviation (RSD) of stability was less than 5%. The intra-day precision was in the range of 1.14% to 2.36%, and the inter-day precision ranged from 1.03% to 2.92%, both of which were less than 5%. The recovery rate ranged from 94.43% to 98.59% with an RSD less than 5%. The results showed that the UHPLC-Q-Exactive Orbitrap/MS technique established in this study can not only be used for the quantification of EGCG and GCG in persimmon fruit flesh but also be suitable for analyzing other PAs monomer compositions, providing robust support for the related research on persimmon PAs.

Sulfur-Bridged Asymmetric CuNi Bimetallic Atom Sites for CO2 Reduction with High Efficiency.

Double-atom catalysts (DACs) with asymmetric coordination are crucial for enhancing the benefits of electrochemical carbon dioxide reduction and advancing sustainable development, however, the rational design of DACs is still challenging. Herein, this work synthesizes atomically dispersed catalysts with novel sulfur-bridged Cu-S-Ni sites (named Cu-S-Ni/SNC), utilizing biomass wool keratin as precursor. The plentiful disulfide bonds in wool keratin overcome the limitations of traditional gas-phase S ligand etching process and enable the one-step formation of S-bridged sites. X-ray absorption spectroscopy (XAS) confirms the existence of bimetallic sites with N2Cu-S-NiN2 moiety. In H-cell, Cu-S-Ni/SNC shows high CO Faraday efficiency of 98.1% at -0.65 V versus RHE. Benefiting from the charge tuning effect between the metal site and bridged sulfur atoms, a large current density of 550 mA cm-2 can be achieved at -1.00 V in flow cell. Additionally, in situ XAS, attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), and density functional theory (DFT) calculations show Cu as the main adsorption site is dual-regulated by Ni and S atoms, which enhances CO2 activation and accelerates the formation of *COOH intermediates. This kind of asymmetric bimetallic atom catalysts may open new pathways for precision preparation and performance regulation of atomic materials toward energy applications.

Design, Fabrication, Characterization, and Simulation of AlN-Based Piezoelectric Micromachined Ultrasonic Transducer for Sonar Imaging Applications.

To address the requirements of sonar imaging, such as high receiving sensitivity, a wide bandwidth, and a wide receiving angle, an AlN PMUT with an optimized ratio of 0.6 for the piezoelectric layer diameter to backside cavity diameter is proposed in this paper. A sample AlN PMUT is designed and fabricated with the SOI substrate-based bulk MEMS process. The characterization test result of the sample demonstrates a -6 dB bandwidth of approximately 500 kHz and a measured receiving sensitivity per unit area of 1.37 V/µPa/mm2, which significantly surpasses the performance of previously reported PMUTs. The -6 dB horizontal angles of the AlN PMUT at 300 kHz and 500 kHz are measured as 68.30° and 54.24°, respectively. To achieve an accurate prediction of its characteristics when being packaged and assembled in a receive array, numerical simulations with the consideration of film stress are conducted. The numerical result shows a maximum deviation of ±7% in the underwater receiving sensitivity across the frequency range of 200 kHz to 1000 kHz and a deviation of about 0.33% in the peak of underwater receiving sensitivity compared to the experimental data. By such good agreement, the simulation method reveals its capability of providing theoretical foundation for enhancing the uniformity of AlN PMUTs in future studies.

Study on the Structure and Properties of Silk Fibers Obtained from Factory All-Age Artificial Diets.

The traditional production mode of the sericulture industry is no longer suitable for the development requirements of modern agriculture; to facilitate the sustainable development of the sericulture industry, factory all-age artificial diet feeding came into being. Understanding the structural characteristics and properties of silk fibers obtained from factory all-age artificial diet feeding is an important prerequisite for application in the fields of textiles, clothing, biomedicine, and others. However, there have been no reports so far. In this paper, by feeding silkworms with factory all-age artificial diets (AD group) and mulberry leaves (ML group), silk fibers were obtained via two different feeding methods. The structure, mechanical properties, hygroscopic properties, and degradation properties were studied by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Structurally, no new functional groups appeared in the AD group. Compared with the ML group, the structure of the two groups was similar, and there was no significant difference in mechanical properties and moisture absorption. The structure of degummed silk fibers is dominated by crystalline regions, but α-chymotrypsin hydrolyzes the amorphous regions of silk proteins, so that after 28 d of degradation, the weight loss of both is very small. This provides further justification for the feasibility of factory all-age artificial diets for silkworms.

High-Entropy Engineering Reinforced Surface Electronic States and Structural Defects of Hierarchical Metal Oxides@Graphene Fibers toward High-Performance Wearable Supercapacitors.

Construction advanced fibers with high Faradic activity and conductivity are effective to realize high energy density with sufficient redox reactions for fiber-based electrochemical supercapacitors (FESCs), yet it is generally at the sacrifice of kinetics and structural stability. Here, a high-entropy doping strategy is proposed to develop high-energy-density FESCs based on high-entropy doped metal oxide@graphene fiber composite (HE-MO@GF). Due to the synergistic participation of multi-metal elements via high-entropy doping, the HE-MO@GF features abundant oxygen vacancies from introducing various low-valence metal ions, lattice distortions, and optimized electronic structure. Consequently, the HE-MO@GF maintains sufficient active sites, a low diffusion barrier, fast adsorption kinetics, improved electronic conductivity, enhanced structural stability, and Faradaic reversibility. Thereinto, HE-MO@GF presents ultra-large areal capacitance (3673.74 mF cm-2) and excellent rate performance (1446.78 mF cm-2 at 30 mA cm-2) in 6 M KOH electrolyte. The HE-MO@GF-based solid-state FESCs also deliver high energy density (132.85 µWh cm-2), good cycle performance (81.05% of capacity retention after 10,000 cycles), and robust tolerance to sweat erosion and multiple washing, which is woven into the textile to power various wearable devices (e.g., watch, badge and luminous glasses). This high-entropy strategy provides significant guidance for designing innovative fiber materials and highlights the development of next-generation wearable energy devices.

An asymmetrically coordinated Zn-Co diatomic site catalyst for efficient hydrogen evolution reactions.

We propose an innovative preparation method, namely, a two-step pyrolysis process, to synthesize Zn-Co bimetallic catalysts with excellent hydrogen evolution performance. In the synthesized Zn1Co1-SNC catalyst, there exists a strong interaction between Zn and Co, along with synergistic effects with S/N atoms, collectively promoting the stability of the catalyst structure. Experimental results demonstrate that the overpotential of this catalyst at 10 mA cm-2 current density is only 49 mV, and it maintains excellent hydrogen evolution performance even after 5000 cycles.

Lattice Strain and Mott-Schottky Effect of the Charge-Asymmetry Pd1Fe Single-Atom Alloy Catalyst for Semi-Hydrogenation of Alkynes with High Efficiency.

The ideal interface design between the metal and substrate is crucial in determining the overall performance of the alkyne semihydrogenation reaction. Single-atom alloys (SAAs) with isolated dispersed active centers are ideal media for the study of reaction effects. Herein, a charge-asymmetry "armor" SAA (named Pd1Fe SAA@PC), which consists of a Pd1Fe alloy core and a semiconducting P-doped C (PC) shell, is rationally designed as an ideal catalyst for the selective hydrogenation of alkynes with high efficiency. Multiple spectroscopic analyses and density functional theory calculations have demonstrated that Pd1Fe SAA@PC is dual-regulated by lattice tensile and Schottky effects, which govern the selectivity and activity of hydrogenation, respectively. (1) The PC shell layer applied an external traction force causing a 1.2% tensile strain inside the Pd1Fe alloy to increase the reaction selectivity. (2) P doping into the C-shell layer realized a transition from a p-type semiconductor to an n-type semiconductor, thereby forming a unique Schottky junction for advancing alkyne semihydrogenation activity. The dual regulation of lattice strain and the Schottky effect ensures the excellent performance of Pd1Fe SAA@PC in the semihydrogenation reaction of phenylethylene, achieving a conversion rate of 99.9% and a selectivity of 98.9% at 4 min. These well-defined interface modulation strategies offer a practical approach for the rational design and performance optimization of semihydrogenation catalysts.

Tunneling Proton Grotthuss Transfer Channels by Hydrophilic-Zincophobic Heterointerface Shielding for High-Performance Zn-MnO2 Batteries.

Hollandite-type manganese dioxide (α-MnO2) is recognized as a promising cathode material upon high-performance aqueous zinc-ion batteries (ZIBs) owing to the high theoretical capacities, high working potentials, unique Zn2+/H+ co-insertion chemistry, and environmental friendliness. However, its practical applications limited by Zn2+ accommodation, where the strong coulombic interaction and sluggish kinetics cause significant lattice deformation, fast capacity degradation, insufficient rate capability, and undesired interface degradation. It remains challenging to accurately modulate H+ intercalation while suppressing Zn2+ insertion for better lattice stability and electrochemical kinetics. Herein, proton Grotthuss transfer channels are first tunneled by shielding MnO2 with hydrophilic-zincophobic heterointerface, fulfilling the H+-dominating diffusion with the state-of-the-art ZIBs performance. Local atomic structure and theoretical simulation confirm that surface-engineered α-MnO2 affords to the synergy of Mn electron t2g-eg activation, oxygen vacancy enrichment, selective H+ Grotthuss transfer, and accelerated desolvation kinetics. Consequently, fortified α-MnO2 achieves prominent low current density cycle stability (≈100% capacity retention at 1 C after 400 cycles), remarkable long-lifespan cycling performance (98% capacity retention at 20 C after 12 000 cycles), and ultrafast rate performance (up to 30 C). The study exemplifies a new approach of heterointerface engineering for regulation of H+-dominating Grotthuss transfer and lattice stabilization in α-MnO2 toward reliable ZIBs.

Sulfur Modified Carbon-Based Single-Atom Catalysts for Electrocatalytic Reactions.

Efficient and sustainable energy development is a powerful tool for addressing the energy and environmental crises. Single-atom catalysts (SACs) have received high attention for their extremely high atom utilization efficiency and excellent catalytic activity, and have broad application prospects in energy development and chemical production. M-N4 is an active center model with clear catalytic activity, but its catalytic properties such as catalytic activity, selectivity, and durability need to be further improved. Adjustment of the coordination environment of the central metal by incorporating heteroatoms (e.g., sulfur) is an effective and feasible modification method. This paper describes the precise synthetic methods for introducing sulfur atoms into M-N4 and controlling whether they are directly coordinated with the central metal to form a specific coordination configuration, the application of sulfur-doped carbon-based single-atom catalysts in electrocatalytic reactions such as ORR, CO2RR, HER, OER, and other electrocatalytic reaction are systematically reviewed. Meanwhile, the effect of the tuning of the electronic structure and ligand configuration parameters of the active center due to doped sulfur atoms with the improvement of catalytic performance is introduced by combining different characterization and testing methods. Finally, several opinions on development of sulfur-doped carbon-based SACs are put forward.

Targeting PKM2 signaling cascade with salvianic acid A normalizes tumor blood vessels to facilitate chemotherapeutic drug delivery.

Aberrant tumor blood vessels are prone to propel the malignant progression of tumors, and targeting abnormal metabolism of tumor endothelial cells emerges as a promising option to achieve vascular normalization and antagonize tumor progression. Herein, we demonstrated that salvianic acid A (SAA) played a pivotal role in contributing to vascular normalization in the tumor-bearing mice, thereby improving delivery and effectiveness of the chemotherapeutic agent. SAA was capable of inhibiting glycolysis and strengthening endothelial junctions in the human umbilical vein endothelial cells (HUVECs) exposed to hypoxia. Mechanistically, SAA was inclined to directly bind to the glycolytic enzyme PKM2, leading to a dramatic decrease in endothelial glycolysis. More importantly, SAA improved the endothelial integrity via activating the ß-Catenin/Claudin-5 signaling axis in a PKM2-dependent manner. Our findings suggest that SAA may serve as a potent agent for inducing tumor vascular normalization.

Nanocavity in hollow sandwiched catalysts as substrate regulator for boosting hydrodeoxygenation of biomass-derived carbonyl compounds.

Hydrodeoxygenation of oxygen-rich molecules toward hydrocarbons is attractive yet challenging in the sustainable biomass upgrading. The typical supported metal catalysts often display unstable catalytic performances owing to the migration and aggregation of metal nanoparticles (NPs) into large sizes under harsh conditions. Here, we develop a crystal growth and post-synthetic etching method to construct hollow chromium terephthalate MIL-101 (named as HoMIL-101) with one layer of sandwiched Ru NPs as robust catalysts. Impressively, HoMIL-101@Ru@MIL-101 exhibits the excellent activity and stability for hydrodeoxygenation of biomass-derived levulinic acid to gamma-valerolactone under 50°C and 1-megapascal H2, and its activity is about six times of solid sandwich counterparts, outperforming the state-of-the-art heterogeneous catalysts. Control experiments and theoretical simulation clearly indicate that the enrichment of levulinic acid and H2 by nanocavity as substrate regulator enables self-regulating the backwash of both substrates toward Ru NPs sandwiched in MIL-101 shells for promoting reaction with respect to solid counterparts, thus leading to the substantially enhanced performance.

Systematic optimization and evaluation of culture conditions for the construction of circulating tumor cell clusters using breast cancer cell lines.

BACKGROUND: Circulating tumor cell (CTC) clusters play a critical role in carcinoma metastasis. However, the rarity of CTC clusters and the limitations of capture techniques have retarded the research progress. In vitro CTC clusters model can help to further understand the biological properties of CTC clusters and their clinical significance. Therefore, it is necessary to establish reliable in vitro methodological models to form CTC clusters whose biological characteristics are very similar to clinical CTC clusters. METHODS: The assays of immunofluorescence, transmission electron microscopy, EdU incorporation, cell adhension and microfluidic chips were used. The experimental metastasis model in mice was used. RESULTS: We systematically optimized the culture methods to form in vitro CTC clusters model, and more importantly, evaluated it with reference to the biological capabilities of reported clinical CTC clusters. In vitro CTC clusters exhibited a high degree of similarity to the reported pathological characteristics of CTC clusters isolated from patients at different stages of tumor metastasis, including the appearance morphology, size, adhesive and tight junctions-associated proteins, and other indicators of CTC clusters. Furthermore, in vivo experiments also demonstrated that the CTC clusters had an enhanced ability to grow and metastasize compared to single CTC. CONCLUSIONS: The study provides a reliable model to help to obtain comparatively stable and qualified CTC clusters in vitro, propelling the studies on tumor metastasis.

A nitrogen-doped carbon nanosheet composited platinum-cobalt single atom alloy catalyst for effective hydrogen evolution reaction.

An electrocatalyst with ultra-small PtCo single atom alloy species evenly dispersed on nitrogen-doped ultra-thin carbon nanosheets (PtCo SAA/NC) was designed. The introduction of single-atom Pt not only maximizes the atomic utilization efficiency of Pt species, but also synergistically enhances the charge transfer characteristics of Co cluster surfaces, thereby increasing the migration and evolution rate of hydrogen ions. The PtCo SAA/NC catalyst exhibits a Tafel slope of 42 mV dec-1 and a low overpotential of 45 mV at 10 mA cm-2 in 0.5 M H2SO4 solution.

Zn Single-Atom Catalysts Enable the Catalytic Transfer Hydrogenation of α,ß-Unsaturated Aldehydes.

Highly active nonprecious-metal single-atom catalysts (SACs) toward catalytic transfer hydrogenation (CTH) of α,ß-unsaturated aldehydes are of great significance but still are deficient. Herein, we report that Zn-N-C SACs containing Zn-N3 moieties can catalyze the conversion of cinnamaldehyde to cinnamyl alcohol with a conversion of 95.5% and selectivity of 95.4% under a mild temperature and atmospheric pressure, which is the first case of Zn-species-based heterogeneous catalysts for the CTH reaction. Isotopic labeling, in situ FT-IR spectroscopy, and DFT calculations indicate that reactants, coabsorbed at the Zn sites, proceed CTH via a "Meerwein-Ponndorf-Verley" mechanism. DFT calculations also reveal that the high activity over Zn-N3 moieties stems from the suitable adsorption energy and favorable reaction energy of the rate-determining step at the Zn active sites. Our findings demonstrate that Zn-N-C SACs hold extraordinary activity toward CTH reactions and thus provide a promising approach to explore the advanced SACs for high-value-added chemicals.

Cryptotanshinone inhibits PFK-mediated aerobic glycolysis by activating AMPK pathway leading to blockade of cutaneous melanoma.

BACKGROUND: Cutaneous melanoma is a kind of skin malignancy with low morbidity but high mortality. Cryptotanshinone (CPT), an important component of salvia miltiorrhiza has potent anti-tumor activity and also indicates therapeutic effect on dermatosis. So we thought that CPT maybe a potential agent for therapy of cutaneous melanoma. METHODS: B16F10 and A375 melanoma cells were used for in vitro assay. Tumor graft models were made in C57BL/6N and BALB/c nude mice for in vivo assay. Seahorse XF Glycolysis Stress Test Kit was used to detect extracellular acidification rate and oxygen consumption rate. Si-RNAs were used for knocking down adenosine monophosphate-activated protein kinase (AMPK) expression in melanoma cells. RESULTS: CPT could inhibit the proliferation of melanoma cells. Meanwhile, CPT changed the glucose metabolism and inhibited phosphofructokinase (PFK)-mediated glycolysis in melanoma cells to a certain extent. Importantly, CPT activated AMPK and inhibited the expression of hypoxia inducible factor 1α (HIF-1α). Both AMPK inhibitor and silencing AMPK could partially reverse CPT's effect on cell proliferation, cell apoptosis and glycolysis. Finally, in vivo experimental data demonstrated that CPT blocked the growth of melanoma, in which was dependent on the glycolysis-mediated cell proliferation. CONCLUSIONS: CPT activated AMPK and then inhibited PFK-mediated aerobic glycolysis leading to inhibition of growth of cutaneous melanoma. CPT should be a promising anti-melanoma agent for clinical melanoma therapy.

Application Prospect of Induced Pluripotent Stem Cells in Organoids and Cell Therapy.

Since its inception, induced pluripotent stem cell (iPSC) technology has been hailed as a powerful tool for comprehending disease etiology and advancing drug screening across various domains. While earlier iPSC-based disease modeling and drug assessment primarily operated at the cellular level, recent years have witnessed a significant shift towards organoid-based investigations. Organoids derived from iPSCs offer distinct advantages, particularly in enabling the observation of disease progression and drug metabolism in an in vivo-like environment, surpassing the capabilities of iPSC-derived cells. Furthermore, iPSC-based cell therapy has emerged as a focal point of clinical interest. In this review, we provide an extensive overview of non-integrative reprogramming methods that have evolved since the inception of iPSC technology. We also deliver a comprehensive examination of iPSC-derived organoids, spanning the realms of the nervous system, cardiovascular system, and oncology, as well as systematically elucidate recent advancements in iPSC-related cell therapies.

Dynamic chloride ion adsorption on single iridium atom boosts seawater oxidation catalysis.

Seawater electrolysis offers a renewable, scalable, and economic means for green hydrogen production. However, anode corrosion by Cl- pose great challenges for its commercialization. Herein, different from conventional catalysts designed to repel Cl- adsorption, we develop an atomic Ir catalyst on cobalt iron layered double hydroxide (Ir/CoFe-LDH) to tailor Cl- adsorption and modulate the electronic structure of the Ir active center, thereby establishing a unique Ir-OH/Cl coordination for alkaline seawater electrolysis. Operando characterizations and theoretical calculations unveil the pivotal role of this coordination state to lower OER activation energy by a factor of 1.93. The Ir/CoFe-LDH exhibits a remarkable oxygen evolution reaction activity (202 mV overpotential and TOF = 7.46 O2 s-1) in 6 M NaOH+2.8 M NaCl, superior over Cl--free 6 M NaOH electrolyte (236 mV overpotential and TOF = 1.05 O2 s-1), with 100% catalytic selectivity and stability at high current densities (400-800 mA cm-2) for more than 1,000 h.

Cascade Dual Sites Modulate Local CO Coverage and Hydrogen-Binding Strength to Boost CO2 Electroreduction to Ethylene.

Rationally modulating the binding strength of reaction intermediates on surface sites of copper-based catalysts could facilitate C-C coupling to generate multicarbon products in an electrochemical CO2 reduction reaction. Herein, theoretical calculations reveal that cascade Ag-Cu dual sites could synergistically increase local CO coverage and lower the kinetic barrier for CO protonation, leading to enhanced asymmetric C-C coupling to generate C2H4. As a proof of concept, the Cu3N-Ag nanocubes (NCs) with Ag located in partial Cu sites and a Cu3N unit center are successfully synthesized. The Faraday efficiency and partial current density of C2H4 over Cu3N-Ag NCs are 7.8 and 9.0 times those of Cu3N NCs, respectively. In situ spectroscopies combined with theoretical calculations confirm that Ag sites produce CO and Cu sites promote asymmetric C-C coupling to *COCHO, significantly enhancing the generation of C2H4. Our work provides new insights into the cascade catalysis strategy at the atomic scale for boosting CO2 to multicarbon products.

A surface strategy boosting the ethylene selectivity for CO2 reduction and in situ mechanistic insights.

Electrochemical reduction of carbon dioxide into ethylene, as opposed to traditional industrial methods, represents a more environmentally friendly and promising technical approach. However, achieving high activity of ethylene remains a huge challenge due to the numerous possible reaction pathways. Here, we construct a hierarchical nanoelectrode composed of CuO treated with dodecanethiol to achieve elevated ethylene activity with a Faradaic efficiency reaching 79.5%. Through on in situ investigations, it is observed that dodecanethiol modification not only facilitates CO2 transfer and enhances *CO coverage on the catalyst surfaces, but also stabilizes Cu(100) facet. Density functional theory calculations of activation energy barriers of the asymmetrical C-C coupling between *CO and *CHO further support that the greatly increased selectivity of ethylene is attributed to the thiol-stabilized Cu(100). Our findings not only provide an effective strategy to design and construct Cu-based catalysts for highly selective CO2 to ethylene, but also offer deep insights into the mechanism of CO2 to ethylene.

A replacement strategy for regulating local environment of single-atom Co-SxN4-x catalysts to facilitate CO2 electroreduction.

The performances of single-atom catalysts are governed by their local coordination environments. Here, a thermal replacement strategy is developed for the synthesis of single-atom catalysts with precisely controlled and adjustable local coordination environments. A series of Co-SxN4-x (x = 0, 1, 2, 3) single-atom catalysts are successfully synthesized by thermally replacing coordinated N with S at elevated temperature, and a volcano relationship between coordinations and catalytic performances toward electrochemical CO2 reduction is observed. The Co-S1N3 catalyst has the balanced COOH*and CO* bindings, and thus locates at the apex of the volcano with the highest performance toward electrochemical CO2 reduction to CO, with the maximum CO Faradaic efficiency of 98 ± 1.8% and high turnover frequency of 4564 h-1 at an overpotential of 410 mV tested in H-cell with CO2-saturated 0.5 M KHCO3, surpassing most of the reported single-atom catalysts. This work provides a rational approach to control the local coordination environment of the single-atom catalysts, which is important for further fine-tuning the catalytic performance.