CO2 hydrogenation to methanol has attracted great interest while suffering from low conversion and high energy input. Herein, tiny Pd3Cu nanoparticles are confined into a metal–organic framework ...(MOF), UiO‐66, to afford Pd3Cu@UiO‐66 for CO2 hydrogenation. Remarkably, it achieves a methanol production rate of 340 μmol g−1 h−1 at 200 °C and 1.25 MPa under light irradiation, far surpassing that in the dark. The photo‐generated electron transfer from the MOF to antibonding orbitals of CO2* promotes CO2 activation and HCOO* formation. In addition, the Pd3Cu microenvironment plays a critical role in CO2 hydrogenation. In contrast to the MOF‐supported Pd3Cu (Pd3Cu/UiO‐66), the Pd3Cu@UiO‐66 exhibits a much higher methanol production rate due to the close proximity between CO2 and H2 activation sites, which greatly facilitates their interaction and conversion. This work provides a new avenue to the integration of solar and thermal energy for efficient CO2 hydrogenation under moderate conditions.
The Pd3Cu nanoparticles encapsulated into a MOF affording Pd3Cu@UiO‐66 exhibits excellent performance in CO2 hydrogenation enhanced by light irradiation. Photo‐generated electrons migrate from the linkers to activate CO2 adsorbed on Zr–oxo clusters. Then activated CO2 accepts spillover H* from Pd3Cu to complete the conversion. Significantly, the Pd3Cu spatial position plays a critical role and UiO‐66‐confined Pd3Cu greatly promotes activity.
Autophagy is a genetically well-controlled cellular process that is tightly controlled by a set of core genes, including the family of autophagy-related genes (ATG). Autophagy is a "double-edged ...sword" in tumors. It can promote or suppress tumor development, which depends on the cell and tissue types and the stages of tumor. At present, tumor immunotherapy is a promising treatment strategy against tumors. Recent studies have shown that autophagy significantly controls immune responses by modulating the functions of immune cells and the production of cytokines. Conversely, some cytokines and immune cells have a great effect on the function of autophagy. Therapies aiming at autophagy to enhance the immune responses and anti-tumor effects of immunotherapy have become the prospective strategy, with enhanced antigen presentation and higher sensitivity to CTLs. However, the induction of autophagy may also benefit tumor cells escape from immune surveillance and result in intrinsic resistance against anti-tumor immunotherapy. Increasing studies have proven the optimal use of either ATG inducers or inhibitors can restrain tumor growth and progression by enhancing anti-tumor immune responses and overcoming the anti-tumor immune resistance in combination with several immunotherapeutic strategies, indicating that induction or inhibition of autophagy might show us a prospective therapeutic strategy when combined with immunotherapy. In this article, the possible mechanisms of autophagy regulating immune system, and the potential applications of autophagy in tumor immunotherapy will be discussed.
With the assistance of microwave irradiation, greenish‐yellow luminescent graphene quantum dots (gGQDs) with a quantum yield (QY) up to 11.7% are successfully prepared via cleaving graphene oxide ...(GO) under acid conditions. The cleaving and reduction processes are accomplished simultaneously using microwave treatment without additional reducing agent. When the gGQDs are further reduced with NaBH4, bright blue luminescent graphene quantum dots (bGQDs) are obtained with a QY as high as 22.9%. Both GQDs show well‐known excitation‐dependent PL behavior, which could be ascribed to the transition from the lowest unoccupied molecular orbital (LUMO) to the highest occupied molecular orbital (HOMO) with a carbene‐like triplet ground state. Electrochemiluminescence (ECL) is observed from the graphene quantum dots for the first time, suggesting promising applications in ECL biosensing and imaging. The ECL mechanism is investigated in detail. Furthermore, a novel sensor for Cd2+ is proposed based on Cd2+ induced ECL quenching with cysteine (Cys) as the masking agent.
Two‐color graphene quantum dots are prepared using a facile microwave‐assisted approach to have fluorescent quantum yields as high as 22.9%. The graphene quantum dots are demonstrated to be electrochemiluminescent. A novel electrochemiluminescence sensor for Cd2+ is proposed based on the competitive coordination between cysteine and graphene quantum dots for metal ions.
The fabrication of intrinsic carbon defects is usually tangled with doping effects, and the identification of their unique roles in catalysis remains a tough task. Herein, a K+‐assisted synthetic ...strategy is developed to afford porous carbon (K‐defect‐C) with abundant intrinsic defects and complete elimination of heteroatom via direct pyrolysis of K+‐confined metal–organic frameworks (MOFs). Positron‐annihilation lifetime spectroscopy, X‐ray absorption fine structure measurement, and scanning transmission electron microscopy jointly illustrate the existence of abundant 12‐vacancy‐type carbon defects (V12) in K‐defect‐C. Remarkably, the K‐defect‐C achieves ultrahigh CO Faradaic efficiency (99%) at −0.45 V in CO2 electroreduction, far surpassing MOF‐derived carbon without K+ etching. Theoretical calculations reveal that the V12 defects in K‐defect‐C favor CO2 adsorption and significantly accelerate the formation of the rate‐determining COOH* intermediate, thereby promoting CO2 reduction. This work develops a novel strategy to generate intrinsic carbon defects and provides new insights into their critical role in catalysis.
A K+‐assisted synthetic strategy is developed to afford porous carbon (K‐defect‐C‐1100) with abundant 12‐vacancy‐type (V12) carbon defects via direct pyrolysis of a K+‐confined metal–organic framework (K+@bio‐MOF‐1) at 1100 °C. Strikingly, the K‐defect‐C‐1100 presents excellent electrocatalytic CO2 reduction activity with ultrahigh CO Faradic efficiency up to 99% at −0.45 V, far surpassing the N‐doped carbon (N‐C‐1100) counterpart.
The purpose of our study was to investigate the underlying mechanism and functional role of microRNA-145 (miR-145) in cervical cancer. In this study, quantitative real-time PCR (qRT-PCR) was used to ...detect miR-145 and FSCN1 expression levels in tissues and HeLa cells. Western blotting was performed to determine the protein level of FSCN1. The luciferase assay was used to verify the direct target of miR-145. The CCK-8 assay and 2D colony formation assays were performed to determine the effects of miR-145 mimics or FSCN1 silencing on cell proliferation. miR-145 expression levels were significantly down-regulated, while FSCN1 expression levels were significantly up-regulated in the cervical carcinoma tissues compared with their matched non-cancerous tissues. In addition, FSCN1 expression levels were negatively correlated to miR-145 in tissues. Next, FSCN1 was verified as the direct target of miR-145 in HeLa cells. Moreover, overexpression of miR-145 dramatically inhibited the proliferation of HeLa cells. The silencing of FSCN1 exhibited the similar patterns on cell proliferation as miR-145 overexpression. The miR-145/ FSCN1 axis contributes to the progression of cervical cancer by inhibition of cervical cancer cell proliferation.
The abnormality of the plasma membrane (PM) is an important biomarker for cell status and many diseases. Hence, visualizing the PM, especially in complex systems, is an emerging field in the life ...sciences, especially in low‐resource settings. Herein, we developed a water‐soluble PM‐specific probe utilizing electrostatic and hydrophobic interaction strategies with aggregation‐induced emission as the signal output. The probe could image the PM with many advanced features (wash‐free, ultrafast staining process, excellent PM specificity, and good biocompatibility), which were demonstrated by the PM imaging of neurons. The probe allowed for the first time the imaging of erythrocytes in the complex brain environment through a fluorescence‐based method. Moreover, the PM of the epidermal and partial view of the eyeball structure of live zebrafish are also revealed.
Insane in the membrane: A plasma membrane (PM)‐specific probe with aggregation‐induced emission characteristics for wash‐free PM imaging is presented. This is the first time that erythrocytes have been visualized in the brain through a fluorescence‐based method. Moreover, a partial view of the eyeball structure of live zebrafish was obtained through the in situ labelling of the epidermal PM.
In this study, the previously overlooked effects of contaminants’ molecular structure on their degradation efficiencies and dominant reactive oxygen species (ROS) in advanced oxidation processes ...(AOPs) are investigated with a peroxymonosulfate (PMS) activation system selected as the typical AOP system. Averagely, degradation efficiencies of 19 contaminants are discrepant in the CoCaAl-LDO/PMS system with production of SO4 •–, •OH, and 1O2. Density functional theory calculations indicated that compounds with high E HOMO, low-energy gap (ΔE = E LUMO – E HOMO), and low vertical ionization potential are more vulnerable to be attacked. Further analysis disclosed that the dominant ROS was the same one when treating similar types of contaminants, namely SO4 •–, 1O2, 1O2, and •OH for the degradation of CBZ-like compounds, SAs, bisphenol, and triazine compounds, respectively. This phenomenon may be caused by the contaminants’ structures especially the commonly shared or basic parent structures which can affect their effective reaction time and second-order rate constants with ROS, thus influencing the contribution of each ROS during its degradation. Overall, the new insights gained in this study provide a basis for designing more effective AOPs to improve their practical application in wastewater treatment.
The new and low-cost iron embedded carbon composites (Fe-BC-700) were prepared by a facile pyrolysis technology. The as-prepared material exhibited an extremely high removal efficiency of biphenol A ...in the presence of peroxymonosulfate (PMS). Besides the sulfate radicals (SO4−) from the PMS activation, the inherent persistent free radicals (PFR) in biochar also played an important role in the degradation of BPA.
Display omitted
•Fe-BC-700 with Fe0, abundant functional groups and nanofibers was facilely prepared.•The high removal efficiency of BPA depends on activation and non-activation factors.•The contribution of the different factors was quantified for the first time.
Activation of peroxymonosulfate (PMS) to degrade recalcitrant organic pollutants has attracted much attention, however, this process usually needs expensive or toxic catalysts. Herein, we prepared a Fe functionalized biochar composite that contain Fe0, porous carbon with abundant functional groups and nanofibers (Fe-BC-700) to activate PMS and efficiently remove bisphenol A (BPA). The contribution of different participants in the complicated system involving Fe species, carbon composites, and radicals and nonradicals were quantitatively investigated. Under optimal conditions (0.2 g/L PMS and 0.15 g/L catalyst), 20 mg/L of BPA can be completely removed in 5 min by Fe-BC-700. The effects including the activation of PMS by Fe species to produce sulfate radicals (SO4−), the electron transfer by the nanofiber-mesoporous carbon structure, and the inherent persistent free radicals (PFR) in biochar, were demonstrated to contribute to the high performance. A series of contrast experiments showed that PMS activated by Fe contributed to about 36% of BPA degradation, while the carbon composites, especially carbon nanofibers contributed to 17%, and the other 47% was ascribed to the adsorption of carbon composites (may further undergoing degradation). Meanwhile, the degradation by SO4− accounted for about 23% (by quenching experiments), while the nonradical pathway contributed to 30%. This work suggests that the non-activation factors in PMS/porous catalyst/pollutant system cannot be neglected.
PDF
