A self-driven solar coupling system with TiO2@MXene cathode for effectively eliminating uranium and organics from complex wastewater accompanying with electricity generation.

The inevitable organic matters in radioactive wastewater and contaminated waters pose great challenge in uranium recycling by traditional techniques. Here, a self-driven solar coupling system (SSCS), which was assembled by a TiO2 @MXene/CF cathode and a monolithic photoanode, was proposed for synergistically recycling uranium and degrading organics from complex radioactive wastewater, combining with electricity production. The TiO2 @MXene/CF was prepared via a simple annealing process with in-situ derived TiO2 nanoparticles decorated Ti3C2 MXene coated on carbon felt (CF). Under sunlight illumination, the photoanode captured electrons of organics, and drove electrons to the TiO2 @MXene/CF, which exhibited an exceptional UO22+ adsorption and reduction capacity because TiO2 nanoparticles provided plenty of surface hydroxyl groups for UO22+ adsorption, and the unique two-dimensional MXene facilitated the charge transfer. The SSCS with TiO2 @MXene/CF removed almost 100% UO22+ and organics with rate constants of ∼21 and ∼6.9 times those of the system with CF, accompanying with excellent power output (∼1000 µW·cm-2). The fixed uranium on TiO2 @MXene/CF was effectively reduced into insoluble UO2 (91.1%), and no obvious decay was observed after 15 repeated uses. This study proposes a multi-functional and easy-operated way for remediating radioactive wastewater and contaminated waters, and gives valuable insights in designing cathode materials for uranium reduction.

NF-κB negatively impacts the myogenic potential of muscle-derived stem cells.

Inhibition of the inhibitor of kappa B kinase (IKK)/nuclear factor-kappa B (NF-κB) pathway enhances muscle regeneration in injured and diseased skeletal muscle, but it is unclear exactly how this pathway contributes to the regeneration process. In this study, we examined the role of NF-κB in regulating the proliferation and differentiation of muscle-derived stem cells (MDSCs). MDSCs isolated from the skeletal muscles of p65(+/-) mice (haploinsufficient for the p65 subunit of NF-κB) had enhanced proliferation and myogenic differentiation compared to MDSCs isolated from wild-type (wt) littermates. In addition, selective pharmacological inhibition of IKKß, an upstream activator of NF-κB, enhanced wt MDSC differentiation into myotubes in vitro. The p65(+/-) MDSCs also displayed a higher muscle regeneration index than wt MDSCs following implantation into adult mice with muscular dystrophy. Additionally, using a muscle injury model, we observed that p65(+/-) MDSC engraftments were associated with reduced inflammation and necrosis. These results suggest that inhibition of the IKK/NF-κB pathway represents an effective approach to improve the myogenic regenerative potential of MDSCs and possibly other adult stem cell populations. Moreover, our results suggest that the improved muscle regeneration observed following inhibition of IKK/NF-κB, is mediated, at least in part, through enhanced stem cell proliferation and myogenic potential.

Synergistically adsorbing and reducing Uranium from water by a novel nano zero-valent copper/MXene 0D/2D nanocomposite.

Proper disposal of uranium-containing waste is of utmost importance for safeguarding the environment and human health. In this study, we proposed a novel zero-dimensional (0D)/two-dimensional (2D) nanocomposite material, nZVC/Ti3C2, composed of nano zero-valent copper (nZVC) nanoparticles loaded onto Ti3C2 MXene nanoflakes, which was prepared using a simple in situ chemical reduction method. The uniform dispersion of 0D nZVC nanoparticles, with a size of approximately 5 nm, onto the 2D ultrathin Ti3C2 MXene effectively prevented agglomeration and corrosion of nZVC. This unique configuration provided numerous adsorption sites for UO22+and facilitated a fascinating charge channel for reducing adsorbed UO22+ into low-mobilized UO2 by nZVC. Under the synergistic effect of Ti3C2 MXene and nZVC, remarkable efficiency and selectivity of nZVC/Ti3C2 for U (VI) removal were demonstrated, which exhibited an exceptional adsorption capacity of up to 360 mg/g, coupled with a high removal efficiency of 97.5 % and rapid kinetics. Importantly, the presence of humic acid did not significantly affect the U (VI) removal efficiency of the composite because of the reduction effect of nZVC. The underlying mechanism of U (VI) removal was elucidated, revealing the involvement of reductive immobilization in the form of UO2 (as high as 73.6 %), inner-sphere surface complexation, and hydrolytic precipitation. This mechanism was dependent on the availability of active nZVC and the solution's pH. These findings highlight the potential of nZVC/Ti3C2 composites as efficient decontaminants for radioactive wastewater, thus contributing to advancements in environmental remediation endeavors.

Molecular basis for the MacroD1-mediated hydrolysis of ADP-ribosylation.

MacroD1 is an enzyme that hydrolyzes protein mono-ADP-ribosylation. However, the key catalytic residues of MacroD1 in these biochemical reactions remain elusive. Here, we present the crystal structure of MacroD1 in a complex with ADP-ribose (ADPR). The ß5-α10-loop functions as a switch loop to mediate substrate recognition and right orientation. The conserved Phe272 in the ß5-α10-loop plays a crucial role in the orientation of ADPR distal ribose, and a conserved hydrogen-bond network contributes significantly to hold and orient the catalytic water12, which mediates ADPR hydrolysis. Moreover, we found that MacroD1 was recruited to the sites of DNA damage via recognition of ADP-ribosylation at DNA lesions. The MacroD1-mediated ADPR hydrolysis is essential for DNA damage repair. Taken together, our study provides structural and functional insights into the molecular mechanism of MacroD1-mediated ADPR hydrolysis and its role in DNA damage repair.

[In vitro study of expression and effects of HSP70/HSP90 in nasopharyngeal carcinoma cells after thermotherapy].

OBJECTIVE: To investigate the changes and effects of HSP70/HSP90 of in nasopharyngeal carcinoma cells HNE1 after thermotherapy. METHODS: HNE1 cells were incubated at 42 degrees C for 2 h. The changes of mRNA and protein level of HSP70/HSP90 were detected by real-time PCR and western-blot at different intervals. HNE1 cells were pretreated with quercetin, geldanamycin or quercetin plus geldanamycin, respectively, before heat treatment. Flow cytometry assay was applied to determine the apoptosis of HNE1 cells before thermotherapy and at 2 h, 4 h, 6 h, 8 h, 12 h and 24 h after thermotherapy. RESULTS: HSP70/HSP90 expression was up regulated at 2 h, reached to its peak at 4 h, descended at 8 h and returned to the normal level at 24 h after thermotherapy. The inhibition of HSP70 through quercetin induced up-regulation and delayed descent of HSP90. Combined pretreatment with quercetin and geldanamycin could significantly induce HNE1 apoptosis when compared with pretreatment with quercetin or geldanamycin alone (P<0.05). CONCLUSION: HSP70/HSP90 expression in HNE1 up regulated promptly after thermotherapy. Inhibition of expression and activity of HSP70/HSP90 before thermotherapy can increase sensitivity of the tumor cell to heat treatment.