Spatial-coupled Ampere-level Electrochemical Propylene Epoxidation over RuO2/Ti Hollow-fiber Penetration Electrodes.

The electrochemical propylene epoxidation reaction (PER) provides a promising route for ecofriendly propylene oxide (PO) production, instantly generating active halogen/oxygen species to alleviate chloride contamination inherent in traditional PER. However, the complex processes and unsatisfactory PO yield for current electrochemical PER falls short of meeting industrial application requirements. Herein, a spatial-coupling strategy over RuO2/Ti hollow-fiber penetration electrode (HPE) is adopted to facilitate efficient PO production, significantly improving PER performance to the ampere level (achieving over 80% PO faradaic efficiency and a maximum PO current density of 859 mA cm-2). The synergetic combination of the penetration effect of HPE and the spatial-coupled reaction sequence, enables the realization of ampere-level PO production with high specificity, exhibiting significant potentials for economically viable PER applications.

Ampere-level CO2 electroreduction with single-pass conversion exceeding 85% in acid over silver penetration electrodes.

Synthesis of valuable chemicals from CO2 electroreduction in acidic media is highly desirable to overcome carbonation. However, suppressing the hydrogen evolution reaction in such proton-rich environments remains a considerable challenge. The current study demonstrates the use of a hollow fiber silver penetration electrode with hierarchical micro/nanostructures to enable CO2 reduction to CO in strong acids via balanced coordination of CO2 and K+/H+ supplies. Correspondingly, a CO faradaic efficiency of 95% is achieved at a partial current density as high as 4.3 A/cm2 in a pH = 1 solution of H2SO4 and KCl, sustaining 200 h of continuous electrolysis at a current density of 2 A/cm2 with over 85% single-pass conversion of CO2. The experimental results and density functional theory calculations suggest that the controllable CO2 feeding induced by the hollow fiber penetration configuration primarily coordinate the CO2/H+ balance on Ag active sites in strong acids, favoring CO2 activation and key intermediate *COOH formation, resulting in enhanced CO formation.

Tensile-Strained Cu Penetration Electrode Boosts Asymmetric C-C Coupling for Ampere-Level CO2-to-C2+ Reduction in Acid.

The synthesis of multicarbon (C2+) products remains a substantial challenge in sustainable CO2 electroreduction owing to the need for sufficient current density and faradaic efficiency alongside carbon efficiency. Herein, we demonstrate ampere-level high-efficiency CO2 electroreduction to C2+ products in both neutral and strongly acidic (pH = 1) electrolytes using a hierarchical Cu hollow-fiber penetration electrode (HPE). High concentration of K+ could concurrently suppress hydrogen evolution reaction and facilitate C-C coupling, thereby promoting C2+ production in strong acid. By optimizing the K+ and H+ concentration and CO2 flow rate, a faradaic efficiency of 84.5% and a partial current density as high as 3.1 A cm-2 for C2+ products, alongside a single-pass carbon efficiency of 81.5% and stable electrolysis for 240 h were demonstrated in a strong acidic solution of H2SO4 and KCl (pH = 1). Experimental measurements and density functional theory simulations suggested that tensile-strained Cu HPE enhances the asymmetric C-C coupling to steer the selectivity and activity of C2+ products.

Three-dimensional reconstruction based on micro-imaging under wavelength-tunable illumination.

The three-dimensional reconstruction technique has been widely applied across various fields, with imaging serving as a fundamental approach to achieve this reconstruction. In the present study, we employed micro-imaging to realize 3D reconstruction based on the "shape from focus" and the chromatic aberration effect. This approach eliminates the need for sample or imaging lens movement to locate the focal plane for obtaining clear images. Instead, by utilizing tunable illuminance, we can adjust the imaging distance through the chromatic aberration, thereby achieving accurate reconstructions. As a means of verification, a simple system was accordingly constructed with an adjustable illuminance range (500-750 nm) at a magnification of 10× for imaging purposes. The fine reconstruction achieved high precision in micrometers; however, the depth of field emerged as an issue during the reconstruction process. To assess this method, a coin was employed, and the resulting reconstruction bias was determined to be as low as 0.01 mm. These findings indicate that the proposed method is practical for surface reconstruction and its capabilities will be further enhanced through optical design improvements.

Nitrogen-Doped Titanium Dioxide for Selective Photocatalytic Oxidation of Methane to Oxygenates.

Photocatalytic conversion of methane (CH4) to value-added chemicals using H2O as the oxidant under mild conditions is a desired sustainable pathway for synthesizing commodity chemicals. However, controlling product selectivity while maintaining high product yields is greatly challenging. Herein, we develop a highly efficient strategy, based on the precise control of the types of nitrogen dopants, and the design of photocatalysts, to achieve high selectivity and productivity of oxygenates via CH4 photocatalytic conversion. The primary product (methanol) is obtained in a high yield of 159.8 µmol·g-1·h-1 and 47.7% selectivity, and the selectivity of oxygenate compounds reached 92.5%. The unique hollow porous structure and substituted nitrogen sites of nitrogen-doped TiO2 synergistically promote its photo-oxidation performance. Furthermore, in situ attenuated total reflectance Fourier transform infrared spectroscopy provides direct evidence of the key intermediates and their evolution for producing methanol and multicarbon oxygenates. This study provides insights into the mechanism of photocatalytic CH4 conversion.

Tracking organic matrix in the seashell by elemental mapping under laser-induced breakdown spectroscopy.

As a biogenic calcium carbonate, the seashell plays a crucial role in marine environmental studies. In these studies, it is essential to investigate the composition of the seashell. In this study, we used laser-induced breakdown spectroscopy (LIBS) to analyze the elemental composition of cultured scallop-shell (Patinopecten yessoensis), with a specific focus on examining the organic elements (C, N, O, H) to track the shell organic matrix (SOM). Our findings indicate that the seashell organic layer can be accurately identified by referencing the strong emission of nitrogen or the low signal of calcium. To further confirm the presence of this layer, we employed fluorescence spectroscopy, Raman spectroscopy and FTIR spectroscopy. Correlation analysis revealed a strong connection between LIBS emissions (H, O, CC) and seashell organics, as well as demonstrated the presence of organics in metallic emissions (Si, Ba). However, when we conducted elemental mapping on the shell cross-section, the distribution similarity was observed between the elements N, Ba, and Sr. Based on the correlation of organics and the distribution similarity, it is concluded that barium is an element associated with the SOM. These results highlight the potential of LIBS for organic analysis, which can complement traditional seashell analysis.

A Sequencing-Based Phylogenetic Analysis of Various Strains of Watermelon Silver Mottle Virus in Northern China and Their One-Step Detection Using Reverse Transcription Loop-Mediated Isothermal Amplification.

Watermelon silver mottle virus (WSMoV), a potentially invasive virus, is known to reduce the yield and degrade the quality of infected crops in Cucurbitaceae and Solanaceae families, resulting in significant economic losses in limited areas of several Asian countries. WSMoV, previously detected on various crops in southern China, has now become more prevalent on watermelon and sweet pepper in the northern cities of China for the first time. A sequencing-based phylogenetic analysis has confirmed that the viral strains infecting cucumber, watermelon, and sweet pepper plants in Shandong Province are most closely related to those isolated from Guangdong, Guangxi, and Taiwan, suggesting a farther and continuous spread of WSMoV throughout China. To develop a fast, accurate, and practical protocol for WSMoV detection, we designed a set of primers from the conserved sequence of the WSMoV nucleocapsid protein (N) gene for a one-step assay based on reverse transcription loop-mediated isothermal amplification (RT-LAMP). The RT-LAMP assay was performed successfully for 50 min at 61°C and exhibited a highly specific result without cross-reactions with other similar viruses and a sensitivity that is 100-fold higher than that of the traditional RT-PCR. The confirmation of 26 WSMoV suspect samples collected from various regions in Shandong through the RT-LAMP testing has demonstrated that the assay is suitable and practical for detection of WSMoV in both laboratory and field settings.

Electrochemical Epoxidation of Propylene to Propylene Oxide via Halogen-Mediated Systems.

As one of the most important derivatives of propylene, the production of propylene oxide (PO) is severely restricted. The traditional chlorohydrin process is being eliminated due to environmental concerns, while processes such as Halcon and hydrogen peroxide epoxidation are limited by cost and efficiency, making it difficult to meet market demand. Therefore, achieving PO production through clean and efficient technologies has received extensive attention, and halogen-mediated electrochemical epoxidation of alkene is considered to be a desirable technology for the production of alkylene oxide. In this work, we used electrochemical methods to synthesize PO in halogen-mediated systems based on a RuO2-loaded Ti (RuO2/Ti) anode and screened out two potential mediated systems of chlorine (Cl) and bromine (Br) for the electrosynthesis of PO. At a current density of 100 mA·cm-2, both Cl- and Br-mediated systems delivered PO Faradaic efficiencies of more than 80%. In particular, the Br-mediated system obtained PO Faradaic efficiencies of more than 90% at lower potentials (≤1.5 V vs RHE) with better electrode structure durability. Furthermore, detailed product distribution investigations and DFT calculations suggested hypohalous acid molecules as key reaction intermediates in both Cl- and Br-mediated systems. This work presents a green and efficient PO production route with halogen-mediated electrochemical epoxidation of propylene driven by renewable electricity, exhibiting promising potential to replace the traditional chlorohydrin process.

A Broad Range Triboelectric Stiffness Sensor for Variable Inclusions Recognition.

With the development of artificial intelligence, stiffness sensors are extensively utilized in various fields, and their integration with robots for automated palpation has gained significant attention. This study presents a broad range self-powered stiffness sensor based on the triboelectric nanogenerator (Stiff-TENG) for variable inclusions in soft objects detection. The Stiff-TENG employs a stacked structure comprising an indium tin oxide film, an elastic sponge, a fluorinated ethylene propylene film with a conductive ink electrode, and two acrylic pieces with a shielding layer. Through the decoupling method, the Stiff-TENG achieves stiffness detection of objects within 1.0 s. The output performance and characteristics of the TENG for different stiffness objects under 4 mm displacement are analyzed. The Stiff-TENG is successfully used to detect the heterogeneous stiffness structures, enabling effective recognition of variable inclusions in soft object, reaching a recognition accuracy of 99.7%. Furthermore, its adaptability makes it well-suited for the detection of pathological conditions within the human body, as pathological tissues often exhibit changes in the stiffness of internal organs. This research highlights the innovative applications of TENG and thereby showcases its immense potential in healthcare applications such as palpation which assesses pathological conditions based on organ stiffness.

JamTac: A Tactile Jamming Gripper for Searching and Grasping in Low-Visibility Environments.

Humans can feel and grasp efficiently in the dark through tactile feedback, whereas it is still a challenging task for robots. In this research, we create a novel soft gripper named JamTac, which has high-resolution tactile perception, a large detection surface, and integrated sensing-grasping capability that can search and grasp in low-visibility environments. The gripper combines granular jamming and visuotactile perception technologies. Using the principle of refractive index matching, a refraction-free liquid-particle rationing scheme is developed, which makes the gripper itself to be an excellent tactile sensor without breaking its original grasping capability. We simultaneously acquire color and depth information inside the gripper, making it possible to sense the shape, texture, hardness, and contact force with high resolution. Experimental results demonstrate that JamTac can be a promising tool to search and grasp in situations when vision is not available.

Highly Efficient CO2 Reduction at Steady 2 A cm-2 by Surface Reconstruction of Silver Penetration Electrode.

Electroreduction of CO2 to CO is a promising route for greenhouse gas resource utilization, but it still suffers from impractical current density and poor durability. Here, a nanosheet shell (NS) vertically standing on the Ag hollow fiber (NS@Ag HF) surface formed by electrochemical surface reconstruction is reported. As-prepared NS@Ag HF as a gas penetration electrode exhibited a high CO faradaic efficiency of 97% at an ultra-high current density of 2.0 A cm-2 with a sustained performance for continuous >200 h operation. The experimental and theoretical studies reveal that promoted surface electronic structures of NS@Ag HF by the nanosheets not only suppress the competitive hydrogen evolution reaction but also facilitate the CO2 reduction kinetics. This work provides a feasible strategy for fabricating robust catalysts for highly efficient and stable CO2 reduction.

Ni Nanoclusters Anchored on Ni-N-C Sites for CO2 Electroreduction at High Current Densities.

Transition metal catalyst-based electrocatalytic CO2 reduction is a highly attractive approach to fulfill the renewable energy storage and a negative carbon cycle. However, it remains a great challenge for the earth-abundant VIII transition metal catalysts to achieve highly selective, active, and stable CO2 electroreduction. Herein, bamboo-like carbon nanotubes that anchor both Ni nanoclusters and atomically dispersed Ni-N-C sites (NiNCNT) are developed for exclusive CO2 conversion to CO at stable industry-relevant current densities. Through optimization of gas-liquid-catalyst interphases via hydrophobic modulation, NiNCNT exhibits as high as Faradaic efficiency (FE) of 99.3% for CO formation at a current density of -300 mA·cm-2 (-0.35 V vs reversible hydrogen electrode (RHE)), and even an extremely high CO partial current density (jCO) of -457 mA·cm-2 corresponding to a CO FE of 91.4% at -0.48 V vs RHE. Such superior CO2 electroreduction performance is ascribed to the enhanced electron transfer and local electron density of Ni 3d orbitals upon incorporation of Ni nanoclusters, which facilitates the formation of the COOH* intermediate.

The Novel Compounds with Biological Activity Derived from Soil Fungi in the Past Decade.

The secondary metabolites isolated from soil fungi have received more and more attention, especially new compounds that exhibited good biological activities. In this review, a total of 546 new compounds are included in the relevant literature since 2011. The new compounds are isolated from soil fungi, We divided these compounds into seven categories, including alkaloids, terpenoids, steroids, ketones, phenylpropanoids, quinones, esters, lactones, etc. In addition, the biological activities and structure-activity relationships of these compounds have also been fully discussed. The activities of these compounds are roughly divided into eight categories, including anticancer activity, antimicrobial activity, anti-inflammatory activity, antioxidant activity, antiviral activity, antimalarial activity, immunosuppressive activity and other activities. Since natural products are an important source of new drugs, this review may have a positive guiding effect on drug screening.

Chloride Ion Adsorption Enables Ampere-Level CO2 Electroreduction over Silver Hollow Fiber.

Electrochemical conversion of CO2 into valuable feedstocks is a promising strategy for carbon neutrality. However, it remains a challenge to possess a large current density, a high faradaic efficiency and excellent stability for practical applications of CO2 utilization. Herein, we report a facile tactic that enables exceedingly efficient CO2 electroreduction to CO by virtue of low-coordination chloride ion (Cl- ) adsorption on a silver hollow fiber (Ag HF) electrode. A CO faradaic efficiency of 92.3 % at a current density of one ampere per square centimeter (1 A cm-2 ) in 3.0 M KCl with a sustained performance observed during a 150-hour test was achieved, which is better than state-of-the-art electrocatalysts. The electrochemical results and density functional theory (DFT) calculations suggested a low-coordination Cl- adsorption on surface of Ag HF, which not only suppressed the competitive hydrogen evolution reaction (HER), but also facilitated the CO2 reduction kinetics.

Hierarchical micro/nanostructured silver hollow fiber boosts electroreduction of carbon dioxide.

Efficient conversion of CO2 to commodity chemicals by sustainable way is of great significance for achieving carbon neutrality. Although considerable progress has been made in CO2 utilization, highly efficient CO2 conversion with high space velocity under mild conditions remains a challenge. Here, we report a hierarchical micro/nanostructured silver hollow fiber electrode that reduces CO2 to CO with a faradaic efficiency of 93% and a current density of 1.26 A · cm-2 at a potential of -0.83 V vs. RHE. Exceeding 50% conversions of as high as 31,000 mL · gcat-1 · h-1 CO2 are achieved at ambient temperature and pressure. Electrochemical results and time-resolved operando Raman spectra demonstrate that enhanced three-phase interface reactions and oriented mass transfers synergistically boost CO production.

Crystal structure and catalytic mechanism of the MbnBC holoenzyme required for methanobactin biosynthesis.

Methanobactins (Mbns) are a family of copper-binding peptides involved in copper uptake by methanotrophs, and are potential therapeutic agents for treating diseases characterized by disordered copper accumulation. Mbns are produced via modification of MbnA precursor peptides at cysteine residues catalyzed by the core biosynthetic machinery containing MbnB, an iron-dependent enzyme, and MbnC. However, mechanistic details underlying the catalysis of the MbnBC holoenzyme remain unclear. Here, we present crystal structures of MbnABC complexes from two distinct species, revealing that the leader peptide of the substrate MbnA binds MbnC for recruitment of the MbnBC holoenzyme, while the core peptide of MbnA resides in the catalytic cavity created by the MbnB-MbnC interaction which harbors a unique tri-iron cluster. Ligation of the substrate sulfhydryl group to the tri-iron center achieves a dioxygen-dependent reaction for oxazolone-thioamide installation. Structural analysis of the MbnABC complexes together with functional investigation of MbnB variants identified a conserved catalytic aspartate residue as a general base required for MbnBC-mediated MbnA modification. Together, our study reveals the similar architecture and function of MbnBC complexes from different species, demonstrating an evolutionarily conserved catalytic mechanism of the MbnBC holoenzymes.

Design, Synthesis, Biological Evaluation and Silico Prediction of Novel Sinomenine Derivatives.

Sinomenine is a morphinan alkaloid with a variety of biological activities. Its derivatives have shown significant cytotoxic activity against different cancer cell lines in many studies. In this study, two series of sinomenine derivatives were designed and synthesized by modifying the active positions C1 and C4 on the A ring of sinomenine. Twenty-three compounds were synthesized and characterized by spectroscopy (IR, 1H-NMR, 13C-NMR, and HRMS). They were further evaluated for their cytotoxic activity against five cancer cell lines, MCF-7, Hela, HepG2, SW480 and A549, and a normal cell line, Hek293, using MTT and CCK8 methods. The chlorine-containing compounds exhibited significant cytotoxic activity compared to the nucleus structure of sinomenine. Furthermore, we searched for cancer-related core targets and verified their interaction with derivatives through molecular docking. The chlorine-containing compounds 5g, 5i, 5j, 6a, 6d, 6e, and 6g exhibited the best against four core targets AKT1, EGFR, HARS and KARS. The molecular docking results were consistent with the cytotoxic results. Overall, results indicate that chlorine-containing derivatives might be a promising lead for the development of new anticancer agents.

Biological Activities of Some New Secondary Metabolites Isolated from Endophytic Fungi: A Review Study.

Secondary metabolites isolated from plant endophytic fungi have been getting more and more attention. Some secondary metabolites exhibit high biological activities, hence, they have potential to be used for promising lead compounds in drug discovery. In this review, a total of 134 journal articles (from 2017 to 2019) were reviewed and the chemical structures of 449 new metabolites, including polyketides, terpenoids, steroids and so on, were summarized. Besides, various biological activities and structure-activity relationship of some compounds were aslo described.

Novel natural compounds from endophytic fungi with anticancer activity.

Plant endophytes are microorganisms that live in healthy plant tissues in part or all of their life history without causing obvious symptoms of infection in the host plants. Endophytes, a new type of microbial resource that can produce a variety of biological constituents, have great values for research and broad prospects for development. This article reviewed the research and development progress of endophytic fungi with cytotoxic activity between 2014 and 2017, including endophytic fungi sources, microbial taxonomy, compound classification and cytotoxic activity. The results showed that the 109 strains of endophytic fungi belong to 3 phyla, 7 classes and 50 genera. The secondary metabolites mainly contained alkaloids, terpenes, steroids, polyketides, quinones, isocoumarins, esters etc. The results of this study provide references for the development of new antitumor drugs and endophytes resources.