Acetylation-mediated proteasomal degradation of core histones during DNA repair and spermatogenesis.

Histone acetylation plays critical roles in chromatin remodeling, DNA repair, and epigenetic regulation of gene expression, but the underlying mechanisms are unclear. Proteasomes usually catalyze ATP- and polyubiquitin-dependent proteolysis. Here, we show that the proteasomes containing the activator PA200 catalyze the polyubiquitin-independent degradation of histones. Most proteasomes in mammalian testes ("spermatoproteasomes") contain a spermatid/sperm-specific α subunit α4 s/PSMA8 and/or the catalytic ß subunits of immunoproteasomes in addition to PA200. Deletion of PA200 in mice abolishes acetylation-dependent degradation of somatic core histones during DNA double-strand breaks and delays core histone disappearance in elongated spermatids. Purified PA200 greatly promotes ATP-independent proteasomal degradation of the acetylated core histones, but not polyubiquitinated proteins. Furthermore, acetylation on histones is required for their binding to the bromodomain-like regions in PA200 and its yeast ortholog, Blm10. Thus, PA200/Blm10 specifically targets the core histones for acetylation-mediated degradation by proteasomes, providing mechanisms by which acetylation regulates histone degradation, DNA repair, and spermatogenesis.

Up-regulation of lncRNA WT1-AS ameliorates Aß-stimulated neuronal injury through modulation of miR-186-5p/CCND2 axis in Alzheimer's disease.

As a common neurodegenerative disorder, Alzheimer's disease (AD) seriously threatens human life. Long non-coding RNAs (lncRNAs) exhibit essential functions in AD development. Nevertheless, the detailed effects and possible mechanisms of lncRNA Wilms tumor 1 Antisense RNA (WT1-AS) in AD are largely unknown. In our studies, a total of 30 serum samples from AD patients were collected, and WT1-AS expressions were detected through qRT-PCR analysis. Additionally, an in vitro AD model was constructed by treating Aß1-42 in human neuroblastoma cells. Functional assays were implemented to assess the impacts of WT1-AS on Aß1-42-stimulated human neuroblastoma cell proliferation together with apoptosis. Moreover, relationship of WT1-AS, microRNA (miR)-186-5p as well as cyclin D2 (CCND2) could be predicted through bioinformatics tools as well as proved via dual-luciferase reporter experiments. Our results showed that WT1-AS together with CCND2 were low-expressed, while miR-186-5p presented high expression in AD serum samples together with Aß1-42-stimulated human neuroblastoma cells. WT1-AS over-expression or miR-186-5p depletion notably promoted the proliferation, reduced the apoptosis, and decreased the p-Tau protein expressions of human neuroblastoma cells induced with Aß1-42. Moreover, miR-186-5p combined with WT1-AS, and CCND2 was modulated by miR-186-5p. Furthermore, CCND2 elevation partially offsets the impacts of miR-186-5p elevation on Aß1-42-stimulated cell proliferation as well as apoptosis mediated with WT1-AS up-regulation. Our results indicated that up-regulation of lncRNA WT1-AS ameliorated Aß-stimulated neuronal damage through modulating miR-186-5p/CCND2 axis, offering a novel direction for AD therapy.

Integrated Transcriptomic and Metabolomic Analysis Reveals the Molecular Regulatory Mechanism of Flavonoid Biosynthesis in Maize Roots under Lead Stress.

Flavonoids are secondary metabolites that play important roles in the resistance of plants to abiotic stress. Despite the widely reported adverse effects of lead (Pb) contamination on maize, the effects of Pb on the biosynthetic processes of flavonoids in maize roots are still unknown. In the present work, we employed a combination of multi-omics and conventional assay methods to investigate the effects of two concentrations of Pb (40 and 250 mg/kg) on flavonoid biosynthesis in maize roots and the associated molecular regulatory mechanisms. Analysis using conventional assays revealed that 40 and 250 mg/kg Pb exposure increased the lead content of maize root to 0.67 ± 0.18 mg/kg and 3.09 ± 0.02 mg/kg, respectively, but they did not result in significant changes in maize root length. The multi-omics results suggested that exposure to 40 mg/kg of Pb caused differential expression of 33 genes and 34 metabolites related to flavonoids in the maize root system, while 250 mg/kg of Pb caused differential expression of 34 genes and 31 metabolites. Not only did these differentially expressed genes and metabolites participate in transferase activity, anthocyanin-containing compound biosynthetic processes, metal ion binding, hydroxyl group binding, cinnamoyl transferase activity, hydroxycinnamoyl transferase activity, and flavanone 4-reductase activity but they were also significantly enriched in the flavonoid, isoflavonoid, flavone, and flavonol biosynthesis pathways. These results show that Pb is involved in the regulation of maize root growth by interfering with the biosynthesis of flavonoids in the maize root system. The results of this study will enable the elucidation of the mechanisms of the effects of lead on maize root systems.

Soil microbial communities' contributions to soil ecosystem multifunctionality in the natural restoration of abandoned metal mines.

On a global scale, the restoration of metal mine ecosystem functions is urgently required, and soil microorganisms play an important role in this process. Conventional studies frequently focused on the relationship between individual functions and their drivers; however, ecosystem functions are multidimensional, and considering any given function in isolation ignores the trade-offs and interconnectedness between functions, which complicates obtaining a comprehensive understanding of ecosystem functions. To elucidate the relationships between soil microorganisms and the ecosystem multifunctionality (EMF) of metal mines, this study investigated natural restoration of metal mines, evaluated the EMF, and used high-throughput sequencing to explore the bacterial and fungal communities as well as their influence on EMF. Bacterial community diversity and composition were more sensitive to mine restoration than fungal community. Bacterial diversity exhibited redundancy in improving N-P-K-S multifunctionality; however, rare bacterial taxa including Dependentiae, Spirochaetes, and WPS-2 were important for metal multifunctionality. Although no clear relationship between fungal diversity and EMF was observed, the abundance of Glomeromycota had a significant effect on the three EMF categories (N-P-K-S, carbon, and metal multifunctionality). Previous studies confirmed a pronounced positive association between microbial diversity and multifunctionality; however, the relationship between microbial diversity and multifunctionality differs among functions' categories. In contrast, the presence of critical microbial taxa exerted stronger effects on mine multifunctionality.

Near-Infrared Light Responsive Surface with Switchable Wettability in Microstructure and Surface Chemistry.

Intelligent surfaces with reversibly switchable wettability have recently drawn considerable attention. One typical strategy to obtain such a surface is to change the surface chemistry or the microstructure. Herein, we report a new smart surface for which the wettability was controlled by both the surface chemistry and microstructure. Various wetting states were reversibly and precisely controlled through heating, pressing, NIR irradiation, and oxygen plasma treatment. The excellent shape memory characteristics of shape memory polyurethane (SMPU) and the controlled release of hydrophobic/hydrophilic oxygen-containing functional groups contributed to this ability. Microcapsules were used to design these smart surfaces. They controlled the release of a fluorinated alkyl silane (FAS) through shell melting, changed the surface composition, and played a decisive role in protecting the FAS against hydrolysis and evaporation to ensure that the surface's wettability is recyclable. Controlling of the surface chemistry or microstructure was repeated for at least 19 or 16 cycles, respectively, which indicated excellent repeatability compared to other smart surfaces. Based on the excellent controllability, the surface exhibited multiple functions, such as liquid directional transport and coefficient of friction control. In addition, it maintained this extraordinary ability under harsh environments owing to the great stability of the SMPU and adequate protection of the FAS by the microcapsules. With switchable wettability based on the surface chemistry and microstructure, this work provides a new principle for designing smart surfaces with wettability controlled in two ways.

Treatment of type II symptomatic ulnar styloid nonunions with reinsertion of the triangular fibrocartilage complex.

PURPOSE: The purpose of this retrospective study was to introduce an alternative technique for the treatment of type II symptomatic ulnar styloid nonunion by the reinsertion of the triangular fibrocartilage complex and the ulnar collateral ligament. METHODS: Between March 2009 and May 2017, 45 patients (34 males and 11 females) suffering from the nonunion of type II ulnar styloid fractures all underwent the subperiosteal resection of the avulsed fragments and the reinsertion of the TFCC and ulnar collateral ligament. Outcome assessments included the ranges of motion of the wrist, grip strength, pain, and Mayo wrist score. The preoperative and postoperative parameters were compared. A P-value less than 0.05 was considered to be statistically significant. RESULT: The mean follow-up period was 21.66 ± 7.93 months (range, 12 to 26 months). At the final follow-up, the mean preoperative flexion and extension were 79.32 ± 4.52° and 74.40 ± 4.36° respectively. The mean preoperative pain score, grip strength, and Mayo wrist score were 32.48 ± 4.00; 23.88 ± 8.38 kg, and 77.72 ± 8.31 respectively. The mean postoperative flexion and extension of the wrist were 80.56 ± 6.32° and 75.43 ± 3.12° respectively. The mean postoperative pain score, grip strength, and Mayo wrist score were 12.41 ± 3.27, 26.31 ± 8.30 kg, and 90.71 ± 7.97 respectively. There were significant differences in pain, grip strength, and Mayo wrist score (P < 0.05), but no significant differences concerning the range of motion of the wrist. CONCLUSION: In the treatment of the nonunion of type II ulnar styloid fractures, the resection of the avulsed fragments followed by the reinsertion of the TFCC and the ulnar collateral ligament with an anchor was a reliable alternative technique, bringing the satisfactory function of the wrist.

Stoichiometry of Nucleotide Binding to Proteasome AAA+ ATPase Hexamer Established by Native Mass Spectrometry.

AAA+ ATPases constitute a large family of proteins that are involved in a plethora of cellular processes including DNA disassembly, protein degradation and protein complex disassembly. They typically form a hexametric ring-shaped structure with six subunits in a (pseudo) 6-fold symmetry. In a subset of AAA+ ATPases that facilitate protein unfolding and degradation, six subunits cooperate to translocate protein substrates through a central pore in the ring. The number and type of nucleotides in an AAA+ ATPase hexamer is inherently linked to the mechanism that underlies cooperation among subunits and couples ATP hydrolysis with substrate translocation. We conducted a native MS study of a monodispersed form of PAN, an archaeal proteasome AAA+ ATPase, to determine the number of nucleotides bound to each hexamer of the WT protein. We utilized ADP and its analogs (TNP-ADP and mant-ADP), and a nonhydrolyzable ATP analog (AMP-PNP) to study nucleotide site occupancy within the PAN hexamer in ADP- and ATP-binding states, respectively. Throughout all experiments we used a Walker A mutant (PANK217A) that is impaired in nucleotide binding as an internal standard to mitigate the effects of residual solvation on mass measurement accuracy and to serve as a reference protein to control for nonspecific nucleotide binding. This approach led to the unambiguous finding that a WT PAN hexamer carried - from expression host - six tightly bound ADP molecules that could be exchanged for ADP and ATP analogs. Although the Walker A mutant did not bind ADP analogs, it did bind AMP-PNP, albeit at multiple stoichiometries. We observed variable levels of hexamer dissociation and an appearance of multimeric species with the over-charged molecular ion distributions across repeated experiments. We posit that these phenomena originated during ESI process at the final stages of ESI droplet evolution.

Provincial and sector-level material footprints in China.

High-income countries often outsource material demands to poorer countries along with the associated environmental damage. This phenomenon can also occur within (large) countries, such as China, which was responsible for 24 to 30% of the global material footprint (MF) between 2007 and 2010. Understanding the distribution and development of China's MF is hence critical for resource efficiency and circular economy ambitions globally. Here we present a comprehensive analysis of China's MF at the provincial and sectoral levels. We combine provincial-level input-output data with sector- and province-specific trade data, detailed material extraction data, and the global input-output database EXIOBASE. We find that some provinces have MFs equivalent to medium-sized, high-income countries and limited evidence of material decoupling. Lower-income regions with high levels of material extraction can have an MF per capita as large as developed provinces due to much higher material intensities. The higher-income south-coastal provinces have lower MF per capita than equally developed provinces. This finding relates partly to differences in economic structure but indicates the potential for improvement across provinces. Investment via capital formation is up to 4 times more resource-intensive than consumption and drives 49 to 86% of provincial-level MFs (the Organisation for Economic Co-operation and Development average is 37%). Resource-efficient production, efficient use of capital goods/infrastructure, and circular design are essential for reductions in China's MF. Policy efforts to shift to a high-quality development model may reduce material intensities, preferably while avoiding the further outsourcing of high-intensity activities to other provinces or lower-income countries.

Quantifying the synergy and trade-offs among economy-energy-environment-social targets: A perspective of industrial restructuring.

Protecting our environment while maintaining economic growth, requires a delicate balance among interlinked sustainable development policies. In this paper, we examine China's economic industries, including a high-resolution of the country's electricity sector during 2020-2030, using a multi-objective optimization model based on Input-Output analysis. This model, investigates the synergy and trade-offs of sustainable development goals in maximizing employment and GDP while minimizing energy and water consumption, CO2 emissions, and five major pollutants to advance a sustainable industrial structure adjustment pathway for China. Our results reveal that there exists both synergies and trade-offs among multiple objectives, e.g., synergy among goals of minimizing air pollutant emissions and trade-offs between minimizing energy consumption and maximizing employment. Through the planned industrial restructuring period (2020-2030), the GDP, employment, carbon emission, and energy consumption will increase respectively by, 96.1%, 7.2%, 16.8%, 16.8%, and 6.3%, while pollutant emissions would decrease. Moreover, our research indicates that energy and water conservation should be prioritized in industrial structure adjustment strategies and policies. Our model demonstrates how the synergies and trade-offs among multiple policy targets can empower policy-makers, especially in developing nations, to make more informed and optimized industrial structure adjustment policies for sustainable development.

Poultry eggshell-derived antimicrobial materials: Current status and future perspectives.

Poultry eggs, the basic foodstuffs of human society, have been extensively consumed for domestic and industrial uses. A large amount of eggshell waste is generated and discarded every year, resulting in a waste of natural resources and a threat to the environment. In this context, the reutilization of eggshell waste has gained increasing attentions. Meanwhile, the overuse of antibiotics has led to the emergence of many drug-resistant bacteria, which greatly endangers public health. Therefore, manufacturing new materials with strong antimicrobial activities has become the focus of many researchers. Recent studies have revealed that eggshells can be applied as solid substances, the raw materials for calcium oxide, and the calcium source for synthesizing hydroxyapatite or other materials with antimicrobial activities. Herein, the preparation methods, antibacterial mechanisms and the applications of these eggshell waste-derived antibacterial materials are summarized in this review. Finally, the current challenges and future directions in this field are discussed.

Degradation of organic pollutants by intimately coupling photocatalytic materials with microbes: a review.

With the rapid development of industry and agriculture, large amounts of organic pollutants have been released into the environment. Consequently, the degradation of refractory organic pollutants has become one of the toughest challenges in remediation. To solve this problem, intimate coupling of photocatalysis and biodegradation (ICPB) technology, which allows the simultaneous action of photocatalysis and biodegradation and thus integrates the advantages of photocatalytic reactions and biological treatments, was developed recently. ICPB consists mainly of porous carriers, photocatalysts, biofilms, and an illuminated reactor. Under illumination, photocatalysts on the surface of the carriers convert refractory pollutants into biodegradable products through photocatalytic reactions, after which these products are completely degraded by the biofilms cultivated in the carriers. Additionally, the biofilms are protected by the carriers from the harmful light and free radicals generated by the photocatalyst. Compared with traditional technologies, ICPB remarkably improves the degradation efficiency and reduces the cost of bioremediation. In this review, we introduce the origin and mechanisms of ICPB, discuss the development of reactors, carriers, photocatalysts, and biofilms used in ICPB, and summarize the applications of ICPB to treat organic pollutants. Finally, gaps in this research as well as future perspectives are discussed.

Socio-economic drivers of rising CO2 emissions at the sectoral and sub-regional levels in the Yangtze River Economic Belt.

As the world's largest inland shipping channel, the Yangtze River Economic Belt (YREB) is strategic to China's sustainable development where policymakers are increasingly emphasizing not only this region's economic development but also its CO2 emission reduction targets. To achieve emission targets in the YREB region, it is essential to identify the driving forces of its CO2 emissions. However, existing studies are not very refined and only examine the overall effects of drivers on CO2 emission changes, while neglecting the sub-regional and sectoral level effects across China. More refined research, therefore, will provide better-targeted policies for emission reduction relevant to regional levels such as the YREB region. Towards this end, this paper integrates the methods of structural decomposition analysis and attribution analysis to demonstrate the driving forces, at both sub-regional and sectoral levels, for YREB's emission changes from 2002 to 2012. Our results reveal the following: (1) Jiangsu Province has always been the main regional source of increasing CO2 emissions in the YREB, accounting for more than 20% of total CO2 emission growth. (2) The Electricity and Heat Production and Supply sector is responsible for most of the increases in CO2 emissions, both in 2002-2007 (609.8 Mt, 54.8%) and 2007-2012 (287.6 Mt, 34%). (3) During the period of 2007-2012, changes in per capita final demand were the primary driving force for the increases in CO2 emissions, while changes in CO2 emission intensity were the largest driving force for decreasing CO2 emissions, respectively accounting for 179.9% and -119.4% of total emission changes in the YREB region. (4) Moreover, the effect of emission intensity mainly exists in the Electricity and Heat Production and Supply sector in the Jiangsu and Zhejiang provinces, accounting for respectively, 10% and 10.4% of the total effects across all economic sectors. Considering the diverse impacts of driving forces in different sub-regions and economic sectors, policymakers should apply more refined measures to utilize varying driving forces in different sub-regions and economic sectors towards sustainable development.

Using Post-graphene 2D Materials to Detect and Remove Pesticides: Recent Advances and Future Recommendations.

Detection and removal of pesticides have become increasingly imperative as the widespread production and use of pesticides severely contaminate soil and groundwater and cause serious problems to non-target species such as human and animals. Recently, new two-dimensional materials beyond graphene (e.g., transition metal dichalcogenides, layered double hydroxides), called post-graphene two-dimensional materials (pg-2DMs), have exhibited promising potentials in detecting and removing pesticides due to their unique physiochemical attributes such as high photocatalytic activity and large specific surface area. This review summarizes the recent advances of utilizing pg-2DMs to detect, degrade and adsorb pesticides (e.g., thiobencarb, methyl parathion, paraquat). The current gaps and future prospects of this field are discussed as well.

Facile synthesis of rGO-MoS2-Ag nanocomposites with long-term antimicrobial activities.

The abuse of antibiotics has led to the emergence of numerous super resistant bacteria, which pose a serious threat to public health. Developing nanomaterials with novel modes of bactericidal activity offers the promise of fighting pathogens without the risk of causing drug resistances. Here, we used reduced graphene oxide (rGO), bulk molybdenum disulfide (MoS2) and silver nitrate (AgNO3) to synthesize a ternary nanocomposite, rGO-MoS2-Ag, via a simple one-pot method. The resulting rGO-MoS2-Ag presented as crumpled and sheet-like structures decorated with Ag nanoparticles. The minimum inhibitory concentration and minimum bactericidal concentration of rGO-MoS2-Ag against Escherichia coli were 50 and 100 µg ml-1, while Staphylococcus aureus reacted only to twice higher concentrations of 100 and 200 µg ml-1, respectively. Notably, rGO-MoS2-Ag exhibited better antibacterial activity towards E. coli and S. aureus than rGO, MoS2, or rGO-MoS2. This result can be attributed to the excellent performance of rGO-MoS2-Ag in destroying the bacterial cell membrane and inducing the generation of reactive oxygen species. The Ag+ ion release of rGO-MoS2-Ag was delayed, endowing the nanocomposite with long-term antibacterial capabilities and better biosafety. Our results indicate that the as-prepared rGO-MoS2-Ag has promising potential for application in biomedicine and public health.

Improving Subnational Input-Output Analyses Using Regional Trade Data: A Case-Study and Comparison.

Environmentally extended input-output analysis (EE-IO) is widely used for evaluating environmental performance (i.e., footprint) at a national level. Many studies have extended their analyses to the subnational level to guide regional policies. One promising method is to embed nationally disaggregated input-output tables, e.g., nesting a provincial level table, into a global multiregional input-output table. However, a widely used approach to environmental assessment generally disaggregates the trade structure at the national level to the provincial level using the same proportions (proportionality assumption). This means that the subnational spatial heterogeneities on international trade are not fully captured. By calculating the Chinese provincial material footprint (MF) based on two approaches-the proportionality assumption and the actual customs statistics-in the same framework, we evaluate the quantitative differences when the proportionality assumption is addressed. By computing MF for 23 aggregated resources across 30 Chinese provinces, our results show for countries with large material flows like China, estimating subnational-level international trade by proportionality assumption may lead to significant differences in material flows at both the disaggregated and aggregated levels. An important follow-up question is whether these differences are also relevant for other footprints.

Reconstruction of Finger Pulp Defects With an Innervated Distally-Based Neurovascular Flap.

PURPOSE: Finger pulp resurfacing is a challenging reconstructive problem. This article introduces sensory reconstruction of finger pulp defects using an innervated distally-based neurovascular flap raised from the dorsum of the thumb. METHODS: From May 2015 to May 2017, the innervated distally-based neurovascular flap was used in 36 patients. The mean age at surgery was 37 years (range, 18-61 years). All patients were assessed using the total active motion (TAM) scoring system of the American Society for Surgery of the Hand. The sensitivity of the flap was tested using static 2-point discrimination. RESULTS: Full flap survival was achieved in 35 cases. Partial necrosis at the distal margin of the flap was observed in 1 case. At the final follow-up (mean, 20 months; range, 18-23 months), the mean TAM of the thumb was 206° (range, 188°-238°), including 8 excellent and 28 good results. The mean TAM of fingers was 266° (range, 251°-282°), including 4 excellent and 32 good results. The mean value of static 2-point discrimination was 5 mm (range, 4-7 mm) in the flap, including 31 excellent and 5 good results. CONCLUSIONS: The innervated distally-based neurovascular flap raised from the dorsum of the thumb is a reliable alternative for sensory reconstruction of finger pulp defects. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Organic-Inorganic Copolymerization for a Homogenous Composite without an Interphase Boundary.

Ionic oligomers and their crosslinking implies a possibility to produce novel organic-inorganic composites by copolymerization. Using organic acrylamide monomers and inorganic calcium phosphate oligomers as precursors, uniformly structured polyacrylamide (PAM)-calcium phosphate copolymer is prepared by an organic-inorganic copolymerization. In contrast to the previous PAM-based composites by mixing inorganic components into polymers, the copolymerized material has no interphase boundary owing to the homogenous incorporation of the organic and inorganic units at molecular level, resulting in a complete and continuous hybrid network. The participation of the ionic binding effect in the crosslinking process can substantially improve the mechanical strength; the copolymer can reach a modulus and hardness of 35.14±1.91 GPa and 1.34±0.09 GPa, respectively, which are far superior to any other PAM-based composites.

Use of the First Dorsal Metacarpal Artery-Based Fascial Flap for Reconstruction of Small Defects on the Dorsum of the Hands.

PURPOSE: To describe the reconstruction of small defects on the dorsum of the hands using a first dorsal metacarpal artery-based fascial flap harvested through the borders of the defect. METHODS: From January, 2015 to May, 2017, 29 patients (29 hands) with soft tissue defects on the dorsum of the hand were treated using a first dorsal metacarpal artery-based fascial flap. At final follow-up, we measured range of motion of the metacarpophalangeal joints and the first web span. RESULTS: Average size of the defects was 2.7 × 2.5 cm. Average size of the flaps was 2.9 × 2.7 cm. Average length of the pedicle was 2.9 cm. All flaps survived. Range of motion of the second to fourth metacarpophalangeal joints reached 93% to 98% of the opposite hand. The span of the first web reached 98% of the opposite hand. CONCLUSIONS: A first dorsal metacarpal artery-based fascial flap can be an alternative for reconstruction of small defects on the dorsum of the hands. Flap harvesting through the border of the defect avoided an additional scar at the donor site. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

A Simple α-Ketoglutarate Electrochemical Biosensor Based on Reduced MoS2 Nanoparticle-Gold Nanoparticle Nanocomposite.

Convenient and sensitive methods for the detection of α-ketoglutarate (α-KG) will be beneficial for biomedical diagnosis and microbial fermentation industry. In this work, reduced MoS2 nanoparticles (rMNs) were prepared by ultrasonication and electrochemical reduction. The rMNs were then decorated with gold nanoparticles (Aunano) to fabricate rMNs-Aunano nanocomposite. The glass carbon electrode modified with rMNs-Aunano nanocomposite (rMNs-Aunano-GCE) showed excellent electro-catalytic oxidation toward NADH with a satisfied reproducibility and exhibited linear response in the range of 38.46-214.29 µM. Moreover, the L-Glutamic dehydrogenase modified rMNs-Aunano-GCE exhibited a sensitive and fast response to α-KG, with a linear response range of 11.12-52.94 µM and a detection limit of 6.25 µM. These findings will pave ways for the α-KG detection and the application of MoS2 or other two-dimensional materials in electrochemical sensing.

Effect of Bulk MoS2 on the Metabolic Profile of Yeast.

MoS2, a kind of two-dimensional material with unique performances, has been widely used in many fields. However, an in-depth understanding of its toxicity is still needed, let alone its effects on the environmental microorganism. Herein, we used different methods, including metabolomics technology, to investigate the influence of bulk MoS2 (BMS) on yeast cells. The results indicated that high concentrations (1 mg/L and more) of BMS could destroy cell membrane and induce ROS accumulation. When exposed to a low concentration of BMS (0.1 mg/L), the intracellular concentrations of many metabolites (e.g., fumaric acid, lysine) increased. However, most of their concentrations descended significantly as the yeast cells were treated with BMS of high concentrations (1 mg/L and more). Metabolomics analysis further revealed that exposure to high concentrations of BMS could significantly affect some metabolic pathways such as amino acid and citrate cycle related metabolism. These findings will be beneficial for MoS2 toxicity assessment and further applications.