Total Glucosides of Paeony Induce Mitochondrial Dysfunction and Apoptosis by Promoting the Degradation of α5-nAChR in Melanoma Cells.

BACKGROUND: Malignant melanoma is the leading cause of skin cancer-related death, with high malignancy and rapid progression. Total glucosides of paeony (TGP) are extracted from the roots of Paeonia Lactiflora Pall and are widely used in the treatment of chronic hepatitis, rheumatoid arthritis, and adjuvant therapy of tumor chemotherapy. METHODS: In the present research, M14 and A375 cells were treated with TGP. CCK8, transwell and western blotting were performed to analyze the effect of TGP on cell function. RESULTS: TGP treatment impeded the proliferation and migration and activated the apoptosis pathway in melanoma cells. Importantly, TGP induced the degradation of α5-nAChR. Overexpression of α5-nAChR inhibited the anti-cancer effect of TGP. In addition, TGP treatment released cytochrome c from mitochondria into the cytoplasm, inducing mitochondrial dysfunction in melanoma cells. TGP also inhibited the phosphorylation of P38-MAPK, and P38-MAPK inhibitor reduced the promoting effect of α5-nAChR in cell proliferation and migration. CONCLUSION: TGP inhibited cell viability and migration and induced mitochondrial dysfunction and apoptosis by promoting the degradation of α5-nAChR in melanoma cells. This research provided a potential therapeutic anti-cancer drug for treatment strategies of melanoma.

Past, present, and future of global research on artificial intelligence applications in dermatology: A bibliometric analysis.

In recent decades, artificial intelligence (AI) has played an increasingly important role in medicine, including dermatology. Worldwide, numerous studies have reported on AI applications in dermatology, rapidly increasing interest in this field. However, no bibliometric studies have been conducted to evaluate the past, present, or future of this topic. This study aimed to illustrate past and present research and outline future directions for global research on AI applications in dermatology using bibliometric analysis. We conducted an online search of the Web of Science Core Collection database to identify scientific papers on AI applications in dermatology. The bibliometric metadata of each selected paper were extracted, analyzed, and visualized using VOS viewer and Cite Space. A total of 406 papers, comprising 8 randomized controlled trials and 20 prospective studies, were deemed eligible for inclusion. The United States had the highest number of papers (n = 166). The University of California System (n = 24) and Allan C. Halpern (n = 11) were the institution and author with the highest number of papers, respectively. Based on keyword co-occurrence analysis, the studies were categorized into 9 distinct clusters, with clusters 2, 3, and 7 containing keywords with the latest average publication year. Wound progression prediction using machine learning, the integration of AI into teledermatology, and applications of the algorithms in skin diseases, are the current research priorities and will remain future research aims in this field.

Research progress of MOF-based membrane reactor coupled with AOP technology for organic wastewater treatment.

MOF-based catalytic membrane reactor (MCMR), which can simultaneously achieve membrane separation and chemical catalytic degradation in an integrated system, is a cutting-edge technology for effective treatment of organic pollutants in water. The coupling of MCMR and advanced oxidation process (AOP) not only significantly improves the pollutant removal efficiency but also inhibits the membrane pollution through self-cleaning effect, thus improving the stability of MCMR. This paper reviews different MCMR systems combined with photocatalysis, Fenton oxidation, and persulfate activation, elucidates the reaction mechanism, discusses key issues to improve system effectiveness, and suggests future challenges and research directions.

Designing reliable and accurate isotope-tracer experiments for CO2 photoreduction.

The photoreduction of carbon dioxide (CO2) into renewable synthetic fuels is an attractive approach for generating alternative energy feedstocks that may compete with and eventually displace fossil fuels. However, it is challenging to accurately trace the products of CO2 photoreduction on account of the poor conversion efficiency of these reactions and the imperceptible introduced carbon contamination. Isotope-tracing experiments have been used to solve this problem, but they frequently yield false-positive results because of improper experimental execution and, in some cases, insufficient rigor. Thus, it is imperative that accurate and effective strategies for evaluating various potential products of CO2 photoreduction are developed for the field. Herein, we experimentally demonstrate that the contemporary approach toward isotope-tracing experiments in CO2 photoreduction is not necessarily rigorous. Several examples of where pitfalls and misunderstandings arise, consequently making isotope product traceability difficult, are demonstrated. Further, we develop and describe standard guidelines for isotope-tracing experiments in CO2 photoreduction reactions and then verify the procedure using some reported photoreduction systems.

Atomically Dispersed Nickel Anchored on a Nitrogen-Doped Carbon/TiO2 Composite for Efficient and Selective Photocatalytic CH4 Oxidation to Oxygenates.

Direct photocatalytic oxidation of methane to liquid oxygenated products is a sustainable strategy for methane valorization at room temperature. However, in this reaction, noble metals are generally needed to function as cocatalysts for obtaining adequate activity and selectivity. Here, we report atomically dispersed nickel anchored on a nitrogen-doped carbon/TiO2 composite (Ni-NC/TiO2 ) as a highly active and selective catalyst for photooxidation of CH4 to C1 oxygenates with O2 as the only oxidant. Ni-NC/TiO2 exhibits a yield of C1 oxygenates of 198 µmol for 4 h with a selectivity of 93 %, exceeding that of most reported high-performance photocatalysts. Experimental and theoretical investigations suggest that the single-atom Ni-NC sites not only enhance the transfer of photogenerated electrons from TiO2 to isolated Ni atoms but also dominantly facilitate the activation of O2 to form the key intermediate ⋅OOH radicals, which synergistically lead to a substantial enhancement in both activity and selectivity.

A review on ZnS-based photocatalysts for CO2 reduction in all-inorganic aqueous medium.

Photocatalytic CO2 reduction mimics natural photosynthesis, which is a potential technology for "carbon neutrality". This article will review the recent research progress of a class of distinguished photocatalytic CO2 reduction systems based on ZnS nanocrystal photocatalysts. We will focus on the pathway of maximizing the photoreduction rate of CO2 by continuously optimizing the catalyst design and the composition of the reaction medium. Such discussions will be meaningful and beneficial for developing universal strategies of solar fuel production. Finally, an outlook will be provided to brighten the prospects of ZnS-based photocatalytic CO2 reduction systems.

Recent Advances in the Research of Photo-Assisted Lithium-Based Rechargeable Batteries.

The application of solar energy is crucial for alleviating the energy crisis and achieving sustainable development. In recent years, photo-assisted rechargeable batteries have attracted researchers because they can directly convert and store solar energy in the batteries. And it also can be used like a normal battery without light illumination. Photo-assisted lithium-based batteries have received more attention than other energy storage systems due to their higher energy density and relatively mature development. This Review focuses on the design of various photo-assisted lithium-based batteries including Li-ion, Li-S, Li-O2 , Li-CO2 and Li-I batteries, as well as the working mechanism of photoelectrodes in these battery systems. The basic understanding and challenge of photo-assisted lithium-based batteries are also discussed. At last, perspectives for the photoelectrode development are provided in the summary to advance photo-assisted energy storage systems.

Recent progress in the design of photocatalytic H2O2 synthesis system.

Photocatalytic synthesis of hydrogen peroxide under mild reaction conditions is a promising technology. This article will review the recent research progress in the design of photocatalytic H2O2 synthesis systems. A comprehensive discussion of the strategies that could solve two essential issues related to H2O2 synthesis. That is, how to improve the reaction kinetics of H2O2 formation via 2e- oxygen reduction reaction and inhibit the H2O2 decomposition through a variety of surface functionalization methods. The photocatalyst design and the reaction mechanism will be especially stressed in this work which will be concluded with an outlook to show the possible ways for synthesizing high-concentration H2O2 solution in the future.

Au Modified F-TiO2 for Efficient Photocatalytic Synthesis of Hydrogen Peroxide.

In this work, Au-modified F-TiO2 is developed as a simple and efficient photocatalyst for H2O2 production under ultraviolet light. The Au/F-TiO2 photocatalyst avoids the necessity of adding fluoride into the reaction medium for enhancing H2O2 synthesis, as in a pure TiO2 reaction system. The F- modification inhibits the H2O2 decomposition through the formation of the ≡Ti-F complex. Au is an active cocatalyst for photocatalytic H2O2 production. We compared the activity of TiO2 with F- modification and without F- modification in the presence of Au, and found that the H2O2 production rate over Au/F-TiO2 reaches four times that of Au/TiO2. In situ electron spin resonance studies have shown that H2O2 is produced by stepwise single-electron oxygen reduction on the Au/F-TiO2 photocatalyst.

A ß-cyclodextrin Modified Graphitic Carbon Nitride with Au Co-Catalyst for Efficient Photocatalytic Hydrogen Peroxide Production.

Photocatalytic hydrogen peroxide (H2O2) production has attracted considerable attention as a renewable and environment-friendly method to replace other traditional production techniques. The performance of H2O2 production remains limited by the inertness of graphitic carbon nitride (CN) towards the adsorption and activation of O2. In this work, a photocatalyst comprising of ß-cyclodextrin (ß-CD)-modified CN with supporting Au co-catalyst (Au/ß-CD-CN) has been utilized for effective H2O2 production under visible light irradiation. The static contact angle measurement suggested that ß-CD modification increased the hydrophobicity of the CN photocatalyst as well as its affinity to oxygen gas, leading to an increase in H2O2 production. The rate of H2O2 production reached more than 0.1 mM/h under visible-light irradiation. The electron spin resonance spectra indicated that H2O2 was directly formed via a 2-electron oxygen reduction reaction (ORR) over the Au/ß-CD-CN photocatalyst.

Electrocatalytic Synthesis of Hydrogen Peroxide over Au/TiO2 and Electrochemical Trace of OOH* Intermediate.

In this work, a series of gold-supported titanium oxide composites have been prepared and high selectivity (over 90%) of hydrogen peroxide is achieved. For the first time, electrochemical impedance spectroscopy and electron spin resonance analysis demonstrate that high charge transfer impedance of the catalyst can suppress the decomposition of OOH* intermediates thus promoting the two-electron process of the oxygen reduction reaction.

Distance Synergy of MoS2 -Confined Rhodium Atoms for Highly Efficient Hydrogen Evolution.

Perturbing the electronic structure of the MoS2 basal plane by confining heteroatoms offers the opportunity to trigger in-plane activity for the hydrogen evolution reaction (HER). The key challenge consists of inducing the optimum HER activity by controlling the type and distribution of confined atoms. A distance synergy of MoS2 -confined single-atom rhodium is presented, leading to an ultra-high HER activity at the in-plane S sites adjacent to the rhodium. By optimizing the distance between the confined Rh atoms, an ultra-low overpotential of 67 mV is achieved at a current density of 10 mA cm-2 in acidic solution. Experiments and first-principles calculations demonstrate a unique distance synergy between the confined rhodium atoms in tuning the reactivity of neighboring in-plane S atoms, which presents a volcanic trend with the inter-rhodium distance. This study provides a new strategy to tailor the activity of MoS2 surface via modulating the distance between confined single atoms.

Stabilizing CuGaS2 by crystalline CdS through an interfacial Z-scheme charge transfer for enhanced photocatalytic CO2 reduction under visible light.

CuGaS2 is one of the most excellent visible-light-active photocatalysts for CO2 reduction and water splitting. However, CuGaS2 suffers from serious deactivation in photocatalytic reactions, which is mainly due to the photo-oxidation induced self-corrosion (Cu+ to Cu2+). Here, we constructed a CuGaS2/CdS hybrid photocatalyst dominated by a Z-scheme charge transfer mechanism. The transfer of photo-generated electrons from excited nanocrystalline CdS to CuGaS2 across the coherent interface reduces Cu2+ formation and favors Cu+ regeneration. This process suppresses the deactivation of CuGaS2 and maintains high performance. Both the activity and stability of photocatalytic CO2 reduction to produce CO over the CuGaS2/CdS hybrid were remarkably improved, which was approximately 4-fold higher than CuGaS2 and 3-fold higher than CdS in converting CO2 into CO. Our study demonstrates that even using the semiconductors prone to photo-corrosion, it is possible to obtain satisfactory catalytic activity and stability by designing efficient Z-scheme-charge-transfer-type photocatalysts.

Intermolecular cascaded π-conjugation channels for electron delivery powering CO2 photoreduction.

Photoreduction of CO2 to fuels offers a promising strategy for managing the global carbon balance using renewable solar energy. But the decisive process of oriented photogenerated electron delivery presents a considerable challenge. Here, we report the construction of intermolecular cascaded π-conjugation channels for powering CO2 photoreduction by modifying both intramolecular and intermolecular conjugation of conjugated polymers (CPs). This coordination of dual conjugation is firstly proved by theoretical calculations and transient spectroscopies, showcasing alkynyl-removed CPs blocking the delocalization of electrons and in turn delivering the localized electrons through the intermolecular cascaded channels to active sites. Therefore, the optimized CPs (N-CP-D) exhibiting CO evolution activity of 2247 µmol g-1 h-1 and revealing a remarkable enhancement of 138-times compared to unmodified CPs (N-CP-A).

Abnormal overexpression of G9a in melanoma cells promotes cancer progression via upregulation of the Notch1 signaling pathway.

Malignant melanoma is a type of very dangerous skin cancer. Histone modifiers usually become dysregulated during the process of carcinoma development, thus there is potential for a histone modifier inhibitor as a useful drug for cancer therapy. There is a multitude of evidence regarding the role of G9a, a histone methyltransferase (HMTase), in tumorigenesis. In this study, we first showed that G9a was significantly upregulated in melanoma patients. Using the TCGA database, we found a significantly higher expression of G9a in primary melanoma samples (n = 461) compared to normal skin samples (n = 551). Next, we knocked down G9a in human M14 and A375 melanoma cell lines in vitro via small interfering RNA (siRNA). This resulted in a significant decrease in cell viability, migration and invasion, and an increase in cell apoptosis. UNC0642 is a small molecule inhibitor of G9a that demonstrates minimal cell toxicity and good in vivo pharmacokinetic characteristics. We investigated the role of UNC0642 in melanoma cells, and detected its anti-cancer effects in vitro and in vivo. Next, we treated cells with UNC0642, and observed a significant decrease in cell viability in M14 and A375 cell lines. Furthermore, treatment with UNC0642 resulted in increased apoptosis. In immunocompetent mice bearing A375 engrafts, treatment with UNC0642 inhibited tumor growth. Results of Western blot analysis revealed that administration of UNC0642 or silencing of G9a expression by siRNA reduced Notch1 expression significantly and decreased the level of Hes1 in A375. All in all, the data from our study demonstrates potential of G9a as a therapeutic target in the treatment of melanoma.

α5-nAChR modulates melanoma growth through the Notch1 signaling pathway.

The roles of α5-nicotinic acetylcholine receptors (α5-nAChRs) in various types of solid cancer have been reported; however, its role in melanoma remains unknown. We knocked down α5-nAChR expression in melanoma cells to investigate the role of α5-nAChR in the proliferation, migration, and invasion of melanoma cells, and its effect on downstream signaling pathways. Using immunohistochemical analysis, we determined that α5-nAChR expression is significantly increased in human melanoma tissues and cell lines compared with normal human skin tissues. Knocking down α5-nAChR expression in melanoma cells in culture significantly inhibited the proliferation, migration, and invasiveness of melanoma cell lines. Specifically, knockdown of α5-nAChR inhibited PI3K-AKT and ERK1/2 signaling activity. Moreover, we confirmed that the Notch1 signaling pathway is the downstream target of α5-nAChR in melanoma. Our findings suggest that α5-nAChR plays a critical role in melanoma development and progression, and that targeting α5-nAChR may be a strategy for melanoma treatment.

A novel "turn-on" fluorescent sensor for hydrogen peroxide based on oxidized porous g-C3 N4 nanosheets.

An oxidized, porous graphitic carbon nitride nanosheets (CNNs) was successfully obtained via a bottom-up approach. The inner filter effect (IFE) of Fe (III) tetrakis (1-methyl-4-pyridyl) porphyrin pentachlorideporphyrin pentachloride (FeTMPyP) on the CNNs results in fluorescence quenching of the CNNs due to the overlap of FeTMPyP absorbance band and CNNs emission band. It is interesting that the quenched fluorescence could be "turned on" in response to the participation of H2 O2 , which caused by decomposition of FeMPyP. In this study, for the first time, a porous fluorescence probe based on CNNs and FeTMPyP was designed and an excellent H2 O2 detection performance with a large detection range of 0.1 ~ 100 µM and a detection limit of 0.07 µM was achieved. Furthermore, the proposed method was successfully used for H2 O2 detection in RAW 264.7 cells.

Optimizing Electron Densities of Ni-N-C Complexes by Hybrid Coordination for Efficient Electrocatalytic CO2 Reduction.

Metal-N-C is a type of attractive electrocatalyst for efficient CO2 reduction to CO. Because of the ambiguity in their atomic structures, the active sites and catalytic mechanisms of the catalysts have remained under debate. Here, the effects of N and C hybrid coordination on the activity of Ni-N-C catalysts were investigated, combining theoretical and experimental methods. The theoretical calculations revealed that N and C hybrid coordination greatly enhanced the capability of single-atom Ni active sites to provide electrons to reactant molecules and strengthens the bonding of Ni to N and C in the Ni-N-C complexes. During the reaction process, the C and N coordination synergistically optimized the reaction energies in the conversion of CO2 to CO. A good agreement between theoretical calculations and electrochemical experiments was achieved based on the newly developed Ni-N-C electrocatalysts. The activity of hybrid-coordination NiN2 C2 was more than double that of single-coordination NiN4 .

Highly Selective Production of Ethylene by the Electroreduction of Carbon Monoxide.

Conversion of carbon monoxide to high value-added ethylene with high selectivity by traditional syngas conversion process is challenging because of the limitation of Anderson-Schulz-Flory distribution. Herein we report a direct electrocatalytic process for highly selective ethylene production from CO reduction with water over Cu catalysts at room temperature and ambient pressure. An unprecedented 52.7 % Faradaic efficiency of ethylene formation is achieved through optimization of cathode structure to facilitate CO diffusion at the surface of the electrode and Cu catalysts to enhance the C-C bond coupling. The highly selective ethylene production is almost without other carbon-based byproducts (e.g. C1 -C4 hydrocarbons and CO2 ) and avoids the drawbacks of the traditional Fischer-Tropsch process that always delivers undesired products. This study provides a new and promising strategy for highly selective production of ethylene from the abundant industrial CO.

Direct and Selective Photocatalytic Oxidation of CH4 to Oxygenates with O2 on Cocatalysts/ZnO at Room Temperature in Water.

Direct conversion of methane into methanol and other liquid oxygenates still confronts considerable challenges in activating the first C-H bond of methane and inhibiting overoxidation. Here, we report that ZnO loaded with appropriate cocatalysts (Pt, Pd, Au, or Ag) enables direct oxidation of methane to methanol and formaldehyde in water using only molecular oxygen as the oxidant under mild light irradiation at room temperature. Up to 250 micromoles of liquid oxygenates with ∼95% selectivity is achieved for 2 h over 10 mg of ZnO loaded with 0.1 wt % of Au. Experiments with isotopically labeled oxygen and water reveal that molecular O2, rather than water, is the source of oxygen for direct CH4 oxidation. We find that ZnO and cocatalyst could concertedly activate CH4 and O2 into methyl radical and mildly oxidative intermediate (hydroperoxyl radical) in water, which are two key precursor intermediates for generating oxygenated liquid products in direct CH4 oxidation. Our study underlines two equally significant aspects for realizing direct and selective photooxidation of CH4 to liquid oxygenates, i.e., efficient C-H bond activation of CH4 and controllable activation of O2.