Simulation and experimental study on laser cleaning of paint-rust mixed layer on a Q235 surface.

In this paper, the theoretical model of laser cleaning of paint-rust mixed layer on the surface of a Q235 steel plate is established from the perspective of the laser ablation effect and the thermal vibration effect. The study simulates the temperature and stress field variations of the mixed layer under different laser power densities. The experiment recorded ablative fumes and vibrational spattering generated during the cleaning process and measured the micro-morphology and surface roughness of the cleaned specimens. The results show that the cleaning mechanism of the paint-rust mixed layer is dominated by the ablation effect at low laser power densities, while the combined effects of ablation and thermal vibration dominate at high laser power densities. However, excessive laser energy can damage the substrate. At a laser power density of 12.37×106 W/c m 2, the substrate surface is free from contamination residues and exhibits a bright, white, metallic gloss, which can be determined as the cleaning threshold for laser cleaning of paint-rust mixed layers. This study provides a valuable reference for the laser cleaning of mixed pollutants of paint and rust on metal surfaces.

METTL3-mediated m6A modification of pri-miR-148a-3p affects prostate cancer progression by regulating TXNIP.

OBJECTIVE: Prostate cancer (PCa) severely affects men's health worldwide. The mechanism of methyltransferase-like 3 (METTL3) in affecting PCa development by regulating miR-148a-3p expression via N6-methyladenosine (m6A) modification was investigated. METHODS: METTL3, miR-148a-3p, and thioredoxin interacting protein (TXNIP) levels were determined using RT-qPCR and Western blotting. The m6A modification level of miR-148a-3p was observed by Me-RIP assay. Bioinformatics website predicted miR-148a-3p and TXNIP levels in PCa and their correlation, and the binding site between them was verified by dual-luciferase assay. The proliferation, migration, invasion, and apoptosis of PCa cells were examined by CCK-8 assay, Transwell assay, and flow cytometry. A transplanted tumor model was established in nude mice to observe the tumor growth ability, followed by determination of TXNIP levels in tumor tissues by immunohistochemistry. RESULTS: METTL3 interference restrained the proliferation, migration, and invasion and promoted apoptosis of PCa cells. METTL3 up-regulated miR-148a-3p by promoting the m6A modification of pri-miR-148a-3p in PCa cells. miR-148a-3p overexpression nullified the inhibitory actions of silencing METTL3 on PCa cell growth. miR-148a-3p facilitated PCa cell growth by silencing TXNIP. METTL3 interference inhibited tumor growth by down-regulating miR-148a-3p and up-regulating TXNIP. CONCLUSION: METTL3 promoted miR-148a-3p by mediating the m6A modification of pri-miR-148a-3p, thereby targeting TXNIP, interfering with METTL3 to inhibit the proliferation, migration and invasion of PCa cells, promote apoptosis, and inhibit tumor growth in nude mice.

Interaction between m6A and ncRNAs and Its Association with Diseases.

Noncoding RNAs (ncRNA) are a kind of endogenous RNA that regulate many vital bioprocesses with limited ability to encode polypeptides. Most of them are involved in transcriptional and posttranscriptional regulations, thus showing some biological effects. N6-methyladenosine (m6A) RNA modification is a reversible modification that adjusts RNA's functions and stability. The enzymes that regulate m6A can be divided into "writers," "readers," and "erasers." Mechanically, m6A modification of microRNA is mainly identified by DGVR8, participating in the processing of primary micro-RNAs, while m6A modification on long noncoding RNA (lnc-RNA) can change its spatial structure and stability to regulate its RNA- or protein-binding ability. The m6A-modified lnc-RNA and circular RNA can act as competing endogenous RNAs, sponge downstream miRNA. Moreover, ncRNA can also regulate m6A level of downstream molecules. Here, we elaborate on recent advances about pathways and underlying molecular mechanisms of how the interaction between m6A and ncRNA is involved in the occurrence and development of various diseases, especially cancer.

Combined transcriptome and proteome analysis provides insights into anthocyanin accumulation in the leaves of red-leaved poplars.

KEY MESSAGE: Anthocyanin was highly accumulated in the leaves of red-leaved poplars; Many structural genes involved in anthocyanin synthesis were significantly up-regulated in 'Quanhong' and 'Xuanhong'; TTG2, HYH, and HY5 may be directly involved in the regulation of anthocyanin synthesis in both red-leaved poplars. The red-leaved poplar cultivars 'Quanhong' and 'Xuanhong' are bud mutations of Populus deltoides cv. 'Zhonglin 2025'. These cultivars are valued for their beautiful shape, lack of flying catkins, and ornamental leaf colors. However, the understanding of the molecular mechanism of anthocyanin accumulation in the leaves of red-leaved poplars is still unclear. Here, we profiled the changes of pigment content, transcriptome and proteome expression in the leaves of three poplar cultivars and the results showed that the ratios of anthocyanin to total chlorophyll in both red-leaved poplars were higher than that in 'Zhonglin 2025', indicating that the anthocyanin was highly accumulated in the leaves of red-leaved poplars. Based on the results of combined transcriptome and proteome analysis, 15 and 11 differentially expressed genes/proteins involved in anthocyanin synthesis were screened in 'Quanhong' and 'Xuanhong', respectively, indicating that the two red-leaved poplar cultivars have slightly different patterns of regulating anthocyanin biosynthesis. Among the 120 transcription factors, 3 (HY5, HYH, and TTG2), may be directly involved in the regulation of anthocyanin synthesis in both red-leaved poplars. This study screens the candidate genes involved in anthocyanin accumulation in the leaves of red-leaved poplars and lays a foundation for further exploring the molecular mechanism of leaf red coloration in red-leaved poplars.

Epitaxial Growth and Integration of Insulating Metal-Organic Frameworks in Electrochemistry.

With tunable pore size and rich active metal centers, metal-organic frameworks (MOFs) have been regarded as the one of the promising materials for catalysis. Prospectively, employing MOFs in electrochemistry would notably broaden the scope of electrocatalysis. However, this application is largely hindered by MOFs' conventionally poor electrical conductivity. Integrating MOFs without compromising their crystalline superiority holds a grand challenge to unveil their pristine electrocatalytic properties. In this work, we introduce an epitaxial growth strategy to accomplish the efficient integration of the insulating MOFs into electrochemistry. Particularly, with pristine-graphene-templated growth, the two-dimensional (2D) single-crystal MOF possesses a large lateral size of ∼23 µm and high aspect ratio up to ∼1500 and exhibits a significant electrochemical enhancement, with a charge transfer resistance of ∼200 ohm and a 30 mA cm-2 current density at only 0.53 V versus a reversible hydrogen electrode. The epitaxial strategy could be further applied to other 2D substrates, such as MoS2. This MOF/graphene 2D architecture sheds light on integrating insulating MOFs into electrochemical applications.

High-Performance Wafer-Scale MoS2 Transistors toward Practical Application.

Atomic thin transition-metal dichalcogenides (TMDs) are considered as an emerging platform to build next-generation semiconductor devices. However, to date most devices are still based on exfoliated TMD sheets on a micrometer scale. Here, a novel chemical vapor deposition synthesis strategy by introducing multilayer (ML) MoS2 islands to improve device performance is proposed. A four-probe method is applied to confirm that the contact resistance decreases by one order of magnitude, which can be attributed to a conformal contact by the extra amount of exposed edges from the ML-MoS2 islands. Based on such continuous MoS2 films synthesized on a 2 in. insulating substrate, a top-gated field effect transistor (FET) array is fabricated to explore key metrics such as threshold voltage (V T ) and field effect mobility (µFE ) for hundreds of MoS2 FETs. The statistical results exhibit a surprisingly low variability of these parameters. An average effective µFE of 70 cm2 V-1 s-1 and subthreshold swing of about 150 mV dec-1 are extracted from these MoS2 FETs, which are comparable to the best top-gated MoS2 FETs achieved by mechanical exfoliation. The result is a key step toward scaling 2D-TMDs into functional systems and paves the way for the future development of 2D-TMDs integrated circuits.

Probing the structure and dynamics of caveolin-1 in a caveolae-mimicking asymmetric lipid bilayer model.

Caveolin-1 is the principle membrane protein of caveolae and plays an important role in various cellular processes. The protein contains two helices (H1 and H2) connected by a three-residue break. Although caveolin-1 is assumed to adopt a U-shaped conformation in the transmembrane domain, with both the N-terminus and C-terminus exposed to the cytoplasm, the structure and dynamics of caveolin-1 in membranes are still unclear. Here, we performed six molecular dynamics simulations to characterize the structure and dynamics of caveolin-1 (residues D82-S136; Cav182-136) in a caveolae-mimicking asymmetric lipid bilayer. The simulations reveal that the structure of the caveolin scaffolding domain of caveolin-1 is dynamic, as it could be either fully helical or partly unstructured. Cav182-136 inserts into the inner leaflet of the asymmetric lipid bilayer with a stable U-shaped conformation and orients almost vertical to the bilayer surface. The simulations also provide new insights into the effects of caveolin-1 on the morphology of caveolae and the possible interacting site of cholesterol on caveolin-1.

Microplastics in different tissues of historical and live samples of endangered mega-fish (Acipenser sinensis) and their potential relevance to exposure pathways.

The Chinese sturgeon (Acipenser sinensis) is an endangered freshwater mega-fish (IUCN-red listed) that survives in the Yangtze River Basin, but the population of which has declined significantly in response to environmental pressures generated by human activities. In order to evaluate the interaction between Chinese sturgeon and microplastics (MPs) for the first time, we examined the gut and gills of historical samples (n = 27), in conjunction with the blood and mucus of live samples (n = 10), to explore the potential pathways involved in MP uptake. We detected MPs in 62.9 % of the field fish, with no significant difference between guts (mean=0.9 items/individual) and gills (mean=0.8 items/individual). The abundance of MPs in fish from 2017 was significantly higher than that from 2015 to 2016 with regards to both gills and gut samples. The size of MPs in gills was significantly smaller than those in guts, yet both contained mostly fibers (90.2 %). No MPs were confirmed in blood, however 62.5 % of mucus samples contained MPs. The MPs in mucus indicated the possibility of MPs entering Chinese sturgeons if their skins were damaged. The body size of Chinese sturgeons affected their MPs uptake by ingestion and inhalation, as less MPs were detected in the gut and gills of smaller individuals. Combining the evidence from historical and live samples, we revealed the presence of MPs in different tissues of Chinese sturgeon and their potential relevance to exposure pathways. Our work expands the understanding of multiple exposure pathways between MPs and long-lived mega-fish, while emphasizing the potential risks of long-term exposure in the field.

In situ copper faceting enables efficient CO2/CO electrolysis.

The copper (Cu)-catalyzed electrochemical CO2 reduction provides a route for the synthesis of multicarbon (C2+) products. However, the thermodynamically favorable Cu surface (i.e. Cu(111)) energetically favors single-carbon production, leading to low energy efficiency and low production rates for C2+ products. Here we introduce in situ copper faceting from electrochemical reduction to enable preferential exposure of Cu(100) facets. During the precatalyst evolution, a phosphate ligand slows the reduction of Cu and assists the generation and co-adsorption of CO and hydroxide ions, steering the surface reconstruction to Cu (100). The resulting Cu catalyst enables current densities of > 500 mA cm-2 and Faradaic efficiencies of >83% towards C2+ products from both CO2 reduction and CO reduction. When run at 500 mA cm-2 for 150 hours, the catalyst maintains a 37% full-cell energy efficiency and a 95% single-pass carbon efficiency throughout.

Bibliometric analysis of METTL3: Current perspectives, highlights, and trending topics.

N6-methyladenosine (m6A) is a representative of RNA methylation modification, which plays a critical role in the epigenetic modification process of regulating human diseases. As a key protein for m6A, methyltransferase 3 (METTL3) had been identified to be associated with a variety of diseases. The publications related to METTL3 were searched in the Web of Science Core Collection from the earliest mention to July 1st, 2022. Being screened by the retrieval strategy, a total of 1,738 articles related to METTL3 were retrieved. Much of our work focused on collecting the data of annual publication outputs, high-yielding countries/regions/authors, keywords, citations, and journals frequently published for qualitative and quantitative analysis. We found that diseases with high correlations to METTL3 not only included various known cancers but also obesity and atherosclerosis. In addition to m6A-related enzyme molecules, the most frequent key molecules were MYC proto-oncogene (C-MYC), Enhancer of zeste homolog 2 (EZH2), and Phosphatase and tensin homolog deleted on chromosome 10 (PTEN). METTL3 and methyltransferase 14 (METTL14) may function through opposite regulatory pathways in the same disease. "Leukemia," "Liver Cancer," and "Glioblastoma" were speculated to be potential hotspots in METTL3 related study. The number of publications had significantly surged year by year, demonstrating the growing importance of the research on epigenetic modification in the pathology of various diseases.

Global Trends of Lipid Metabolism Research in Epigenetics Field: A Bibliometric Analysis from 2012-2021.

Most common diseases are characterized by metabolic changes, among which lipid metabolism is a hotspot. Numerous studies have demonstrated a strong correlation between epigenetics and lipid metabolism. This study of publications on the epigenetics of lipid metabolism searched in the Web of Science Core Collection from 2012 to 2022, and a total of 3685 publications were retrieved. Much of our work focused on collecting the data of annual outputs, high-yielding countries and authors, vital journals, keywords and citations for qualitative and quantitative analysis. In the past decade, the overall number of publications has shown an upward trend. China (1382, 26.69%), the United States (1049, 20.26%) and Italy (206, 3.98%) were the main contributors of outputs. The Chinese Academy of Sciences and Yale University were significant potential cooperation institutions. Articles were mainly published in the "International Journal of Molecular Sciences". In addition to typical liver-related diseases, "ferroptosis", "diabetes" and "atherosclerosis" were identified as potential research topics. "NF-κB" and "oxidative stress" were referred to frequently in publications. METTL3 and ALKBH5 were the most discussed m6A-related enzymes in 2022. Our study revealed research hotspots and new trends in the epigenetics of lipid metabolism, hoping to provide significant information and inspiration for researchers to further explore new directions.

Distribution Characteristics of Microplastics in Surface Seawater off the Yangtze River Estuary Section and Analysis of Ecological Risk Assessment.

Microplastics are widespread in the oceans as a new type of pollutant. Due to the special geographical environment characteristics, the Yangtze River estuary region become hotspot for microplastics research. In 2017 and 2019, surface seawater microplastics samples were collected from five stations off the Yangtze River estuary during four seasons (spring, summer, autumn, and winter). The abundance and characteristics of microplastics in seawater were researched. The results showed that microplastics widely existed in surface seawater; the average abundance of microplastics in seawater was (0.17 ± 0.14) items/m3 (0.00561 ± 0.00462) mg/m3; and accounting for 80% of the total plastic debris, the abundance of microplastics was at moderately low levels compared to national and international studies. The particle size of most microplastics was between 1 mm to 2 mm, accounting for 36.1% of the total microplastics. The main shapes of microplastics were fiber, flake, and line, accounting for 39.5%, 28.4%, and 20.8%, respectively. Polypropylene, polyethylene terephthalate, and polyethylene were the main components of microplastics, accounting for 41.0%, 25.1%, and 24.9%, respectively. Yellow, green, black, and transparent were the most common colors, accounting for 21.9%, 19.6%, 16.5%, and 15.7%, respectively. This study shows that the spatial distribution of microplastics in the surface waters off the Yangtze River estuary shows a decreasing trend from nearshore to farshore due to the influence of land-based inputs, hydrodynamics, and human activities; the distribution of microplastics has obvious seasonal changes, and the level of microplastic pollution is higher in summer. The potential ecological risk of microplastics in the surface waters off the Yangtze River estuary is relatively small.

Metabolomic analysis and pathway profiling of paramylon production in Euglena gracilis grown on different carbon sources.

Paramylon (ß-1,3-glucan) produced by Euglena gracilis displays antioxidant, antitumor, and hypolipidaemic functions. The biological properties of paramylon production by E. gracilis can be understood by elucidating the metabolic changes within the algae. In this study, the carbon sources in AF-6 medium were replaced with glucose, sodium acetate, glycerol, or ethanol, and the paramylon yield was measured. Adding 0.1260 g/L glucose to the culture medium resulted in the highest paramylon yield of 70.48 %. The changes in metabolic pathways in E. gracilis grown on glucose were assessed via non-targeted metabolomics analysis using ultra-high-performance liquid chromatography coupled to high-resolution quadrupole-Orbitrap mass spectrometry. We found that glucose, as a carbon source, regulated some differentially expressed metabolites, including l-glutamic acid, γ-aminobutyric acid (GABA), and l-aspartic acid. Pathway analysis using the Kyoto Encyclopedia of Genes and Genomes further showed that glucose regulated the carbon and nitrogen balance through the GABA shunt, which enhanced photosynthesis, regulated the flux of carbon and nitrogen into the tricarboxylic acid cycle, promoted glucose uptake, and increased the accumulation of paramylon. This study provides new insights into E. gracilis metabolism during paramylon synthesis.

Reversing the Polarity of MoS2 with PTFE.

Pristine monolayer molybdenum disulfide (MoS2) demonstrates predominant and persistent n-type semiconducting polarity due to the natural sulfur vacancy, which hinders its electronic and optoelectronic applications in the rich bipolarity area of semiconductors. Current doping strategies in single-layer MoS2 are either too mild to reverse the heavily n-doped polarity or too volatile to create a robust electronic device meeting the requirements of both a long lifetime and compatibility for mass production. Herein, we demonstrate that MoS2 can be transferred onto polytetrafluoroethylene (PTFE), one of the most electronegative substrates. After transfer, the MoS2 photoluminescence exhibits an obvious blueshift from 1.83 to 1.89 eV and a prolonged lifetime, from 0.13 to 3.19 ns. The Fermi level of MoS2 experiences a remarkable 510 meV decrease, transforming its electronic structure into that of a hole-rich p-type semiconductor. Our work reveals a strong p-doping effect and charge transfer between MoS2 and PTFE, shedding light on a new nonvolatile strategy to fabricate p-type MoS2 devices.

Wafer-scale functional circuits based on two dimensional semiconductors with fabrication optimized by machine learning.

Triggered by the pioneering research on graphene, the family of two-dimensional layered materials (2DLMs) has been investigated for more than a decade, and appealing functionalities have been demonstrated. However, there are still challenges inhibiting high-quality growth and circuit-level integration, and results from previous studies are still far from complying with industrial standards. Here, we overcome these challenges by utilizing machine-learning (ML) algorithms to evaluate key process parameters that impact the electrical characteristics of MoS2 top-gated field-effect transistors (FETs). The wafer-scale fabrication processes are then guided by ML combined with grid searching to co-optimize device performance, including mobility, threshold voltage and subthreshold swing. A 62-level SPICE modeling was implemented for MoS2 FETs and further used to construct functional digital, analog, and photodetection circuits. Finally, we present wafer-scale test FET arrays and a 4-bit full adder employing industry-standard design flows and processes. Taken together, these results experimentally validate the application potential of ML-assisted fabrication optimization for beyond-silicon electronic materials.

Phase, Conductivity, and Surface Coordination Environment in Two-Dimensional Electrochemistry.

The booming frontier of electrochemistry is radically transforming the landscape of global chemical and energy industry. Most recent advancements in electrocatalysts have been built on trial and error, lacking model experiments to illuminate the fundamental factors hidden behind, such as phase, conductivity, and surface coordination environment. Here, we use phase-controllable, highly oriented two-dimensional MoTe2 as the model catalysts. The 2H phase MoTe2's conductivity can be engineered both extrinsically and intrinsically by single-layer graphene and lithiation, bringing down the sheet resistance from 0.95 MΩ/□ to 0.8 kΩ/□ and 0.6 kΩ/□. The corresponding electrocatalytic performance was unlocked from a silent state, catching up to its 1T' counterpart, with a parallel Tafel slope of 141 mV/dec. A focused ion beam further exposed the edge atoms, which exhibited a hydrogen evolution turnover frequency 104 times superior to that of basal plane atoms.

Optimizing Nonlinear Optical Visibility of Two-Dimensional Materials.

Two-dimensional (2D) materials have attracted broad research interests across various nonlinear optical (NLO) studies, including nonlinear photoluminescence (NPL), second harmonic generation (SHG), transient absorption (TA), and so forth. These studies have unveiled important features and information of 2D materials, such as in grain boundaries, defects, and crystal orientations. However, as most research studies focused on the intrinsic NLO processes, little attention has been paid to the substrates underneath. Here, we discovered that the NLO signal depends significantly on the thickness of SiO2 in SiO2/Si substrates. A 40-fold enhancement of the NPL signal of graphene was observed when the SiO2 thickness was varied from 270 to 125 nm under 800 nm excitation. We systematically studied the NPL intensity of graphene on three different SiO2 thicknesses within a pump wavelength range of 800-1100 nm. The results agreed with a numerical model based on back reflection and interference. Furthermore, we have extended our measurements to include TA and SHG of graphene and MoS2, confirming that SiO2 thickness has similar effects on all of the three major types of NLO signals. Our results will serve as an important guidance for choosing the optimum substrates to conduct NLO research studies on 2D materials.