CuO Quantum Dots Supported by SrTiO3 Perovskite Using the Flame Spray Pyrolysis Method: Enhanced Activity and Excellent Thermal Resistance for Catalytic Combustion of CO and CH4.

As a non-noble-metal catalyst, CuO has great potential in the catalytic combustion of CO and CH4. In this work, the influence of loading active copper components onto perovskites and essential operating parameters in flame aerosol synthesis has been experimentally and theoretically investigated to optimize the catalytic efficiency for the complete oxidation of lean CO and CH4. Herein, the CuO-SrTiO3 nanocatalysts are one-step-synthesized by flame spray pyrolysis with varied copper loadings and precursor feeding rates. The sample under the precursor flow rate of 3 mL/min and the CuO loading of 15 mol % demonstrates optimal catalytic performance. It is primarily attributed to the excellent low-temperature reducibility and improved activity of copper species originated by CuO quantum dots and metal-support interaction. Besides, SrTiO3 perovskite as a support can effectively inhibit the sintering of CuO quantum dots at high temperatures, which is responsible for the excellent sintering and water deactivation resistances.

Ubiquitin-specific peptidase 46 (USP46) suppresses renal cell carcinoma tumorigenesis through AKT pathway inactivation.

USP46, a member of the ubiquitin-specific protease family, plays essential roles in cancer cell proliferation and metastasis and is used as a candidate target for cancer therapeutics. However, the effects of USP46 on renal cell carcinoma (RCC) and its underlying molecular mechanism remain unknown. In this study, the predictive and prognostic relevance of USP46 in RCC, patient-derived primary tissues, and normal liver tissues obtained from the TCGA dataset were analyzed for the USP46 mRNA levels or prognostic relevance. Gain-of-function or loss-of-function assays were used to evaluate the vital roles of USP46 in tumor cell proliferation and cell migration. As a result, the USP46 expression level in RCC is highly decreased compared to normal tissues, and the Kaplan-Meier curve showed that USP46 high expression patients had good prognoses. Functionally, the forced expression of USP46 significantly restrained tumor cell proliferation, colony formation, and cell migration. The shRNA mediated USP46 knockdown cells exhibited the opposite results. We further showed that ectopically expressed USP46 obviously inhibited the AKT signaling pathway in cancer cells, while USP46 depletion caused a dramatic increase in AKT activity reflected by phosphorylation in the serine and threonine residues of AKT or downstream p70S6K1. Importantly, MK2206, a specific AKT inhibitor, completely counteracted the effects on cell proliferation, cell migration, and AKT activity in the USP46 depletion cells. We thus revealed a novel mechanism of USP46 regulation in RCC, and our data indicate that USP46 is a tumor suppressor in RCC via AKT signaling pathway inactivation.

Carbon Quantum Dot Implanted Graphite Carbon Nitride Nanotubes: Excellent Charge Separation and Enhanced Photocatalytic Hydrogen Evolution.

Graphite carbon nitride (g-C3 N4 ) is a promising candidate for photocatalytic hydrogen production, but only shows moderate activity owing to sluggish photocarrier transfer and insufficient light absorption. Herein, carbon quantum dots (CQDs) implanted in the surface plane of g-C3 N4 nanotubes were synthesized by thermal polymerization of freeze-dried urea and CQDs precursor. The CQD-implanted g-C3 N4 nanotubes (CCTs) could simultaneously facilitate photoelectron transport and suppress charge recombination through their specially coupled heterogeneous interface. The electronic structure and morphology were optimized in the CCTs, contributing to greater visible light absorption and a weakened barrier of the photocarrier transfer. As a result, the CCTs exhibited efficient photocatalytic performance under light irradiation with a high H2 production rate of 3538.3 µmol g-1 h-1 and a notable quantum yield of 10.94 % at 420 nm.

Tailor-Made Core-Shell CaO/TiO2-Al2O3 Architecture as a High-Capacity and Long-Life CO2 Sorbent.

CaO-based sorbents are widely used for CO2 capture, steam methane reforming, and gasification enhancement, but the sorbents suffer from rapid deactivation during successive carbonation/calcination cycles. This research proposes a novel self-assembly template synthesis (SATS) method to prepare a hierarchical structure CaO-based sorbent, Ca-rich, Al2O3-supported, and TiO2-stabilized in a core-shell microarchitecture (CaO/TiO2-Al2O3). The cyclic CO2 capture performance of CaO/TiO2-Al2O3 is compared with those of pure CaO and CaO/Al2O3. CaO/TiO2-Al2O3 sorbent achieved superior and durable CO2 capture capacity of 0.52 g CO2/g sorbent after 20 cycles under the mild calcination condition and retained a high-capacity and long-life performance of 0.44 g CO2/g sorbent after 104 cycles under the severe calcination condition, much higher than those of CaO and CaO/Al2O3. The microstructure characterization of CaO/TiO2-Al2O3 confirmed that the core-shell structure of composite support effectively inhibited the reaction between active component (CaO particles) and main support (Al2O3 particles) by TiO2 addition, which contributed to its properties of high reactivity, thermal stability, mechanical strength, and resistance to agglomeration and sintering.

Ubiquitin-specific peptidase 53 inhibits the occurrence and development of clear cell renal cell carcinoma through NF-κB pathway inactivation.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is one of the most prevalent malignant diseases in the urinary system with more than 140,000 related deaths annually. Ubiquitination-deubiquitination homeostasis is an important factor in ccRCC progression; ubiquitin-specific peptidase 53 (USP53) belongs to the family of deubiquitinating enzymes, but its functions are rarely reported. METHODS: Databases obtained from GEO and TCGA were analyzed to reveal the role of USP53 in ccRCC. CCK-8/BrdU and EDU assays were used to detect the proliferation of ccRCC after USP53 overexpression or knockdown. A tumor xenograft experiment was used to verify the effect of the proliferation of ccRCC after USP53 knockdown. Transwell assays were used to detect the metastasis of ccRCC after USP53 overexpression or knockdown. RNA sequencing and western blot analysis were employed to detect the change in genes after USP53 overexpression and knockdown. Then we tested the effect of USP53 on IκBα protein stability through western blot analysis. Detect the effect of USP53 on IκBα ubiquitination in vitro by immunoprecipitation method. RESULTS: USP53 expression was downregulated in ccRCC tissues and USP53 expression was significantly negatively correlated with the tumor progression and clinical prognosis. The ability of growth and metastasis of ccRCC was inhibited after USP53 overexpression. In addition, USP53 knockdown promoted ccRCC growth and metastasis. Moreover, USP53 knockdown promoted the ability of clone formation of ccRCC in vivo. NF-κB signaling pathway significantly enriched and downregulated in USP53 overexpressed cells, and genes in the NF-κB pathway (such as IL1B, CXCL1-3, RELA, RELB, etc.) were obviously downregulated in USP53 overexpressed cells. USP53 overexpression decreased the phosphorylation of IKKß and P65 in both Caki-1 and 786-O cells, and the expression of IκBα was increased. Phosphorylation of IKKß and P65 was increased in both Caki-1 and 786-O cells after USP53 knockdown. As the expression of USP53 increases, the protein expression of IκBα was also gradually increased and USP53 reduced the ubiquitination of IκBα. CONCLUSION: In summary, our data indicate that USP53 inhibits the inactivation of the NF-κB pathway by reducing the ubiquitination of IκBα to further inhibit ccRCC proliferation and metastasis. These findings may help understand the pathogenesis of ccRCC and introduce new potential therapeutic targets for kidney cancer patients.

An antibody-aptamer sandwich cathodic photoelectrochemical biosensor for the detection of progesterone.

The progesterone (P4) level in body fluids can act as an indicator for early pregnancy diagnosis and offers insight into mammalian somatic function. In this work, we designed an antibody-aptamer based sandwich assay as a cathodic photoelectrochemical (PEC) biosensor for P4 detection. The composites of carbon dots and graphene oxide (CDs-GO) with favorable cathodic photocurrent response were used as photoactive materials on which the antibody (Ab) of P4 was immobilized. Meanwhile, high affinity truncated P4 aptamer was immobilized on Au-CuO-Cu2O to act as a bioconjugate. When P4 was present, the aptamer-Au-CuO-Cu2O bioconjugate could amplify the cathodic photocurrent of CDs-GO modified electrode through Ab-P4-aptamer interactions. Under optimum conditions, the cathodic photocurrent of the constructed PEC biosensor was found to increase linearly with P4 in a wide concentration range from 0.5 nM to 180 nM, with a low detection limit (3S/N) of 0.17 nΜ. The proposed cathodic PEC sensing platform demonstrated high selectivity, satisfying reproducibility, good stability. The sensor was successfully applied in the determination of P4 in human serum samples.

Cathodic "signal-on" photoelectrochemical aptasensor for chloramphenicol detection using hierarchical porous flower-like Bi-BiOI@C composite.

A novel p-type semiconductor-based cathodic "signal-on" photoelectrochemical (PEC) aptasensor was proposed for highly sensitive and selective detection of chloramphenicol (CAP). The photocathode was fabricated with hierarchical porous flower-like Bi-BiOI@C composite synthesized via a one-pot solvothermal method using glucose as both green reductant and carbon precursor. Due to the surface plasmon resonance (SPR) effect of Bi and high-conductivity of carbon, the composite exhibited an enhanced cathodic photocurrent as compared with pure BiOI or Bi-BiOI. When CAP-binding aptamer was immobilized as recognition element on Bi-BiOI@C modified electrode, a cathodic PEC aptasensor showing specific "signal-on" response to CAP was constructed. Some influencing factors such as coating amount of Bi-BiOI@C suspension, applied bias potential, and aptamer concentration were studied. Under the optimum conditions, the cathodic photocurrent of the constructed PEC aptasensor increased linearly with CAP concentration from 2 to 250 nM, with a detection limit (3S/N) of 0.79 nΜ. The proposed sensor was successfully applied to the determination of CAP in pharmaceutical tablet, eye drop and lake water samples.

One-Step Synthesis of CuO-Cu2O Heterojunction by Flame Spray Pyrolysis for Cathodic Photoelectrochemical Sensing of l-Cysteine.

CuO-Cu2O heterojunction was synthesized via a one-step flame spray pyrolysis (FSP) process and employed as photoactive material in construction of a photoelectrochemical (PEC) sensing device. The surface analysis showed that CuO-Cu2O nanocomposites in the size less than 10 nm were formed and uniformly distributed on the electrode surface. Under visible light irradiation, the CuO-Cu2O-coated electrode exhibited admirable cathodic photocurrent response, owing to the favorable property of the CuO-Cu2O heterojunction such as strong absorption in the visible region and effective separation of photogenerated electron-hole pairs. On the basis of the interaction of l-cysteine (l-Cys) with Cu-containing compounds via the formation of Cu-S bond, the CuO-Cu2O was proposed as a PEC sensor for l-Cys detection. A declined photocurrent response of CuO-Cu2O to addition of l-Cys was observed. Influence factors including CuO-Cu2O concentration, coating amount of CuO-Cu2O, and applied bias potential on the PEC response toward l-Cys were optimized. Under optimum conditions, the photocurrent of the proposed sensor was linearly declined with increasing the concentration of l-Cys from 0.2 to 10 µM, with a detection limit (3S/N) of 0.05 µM. Moreover, this PEC sensor displayed high selectivity, reproducibility, and stability. The potential applicability of the proposed PEC sensor was assessed in human urine samples.