Single-atom photo-catalysts:Synthesis,characterization,and applications

Single-atom catalysts(SACs)are gaining popularity in catalytic reactions due to their nearly 100%atomic utilization and defined active sites,which provide great convenience for studying the catalytic mechanism of catalysts.However,SACs still present challenges such as complex formation processes,low loading and easy agglomeration of catalysts.Herein,we systematically discuss the synthesis methods for SACs,including coprecipitation,impregnation,atomic layer deposition,pyrolysis and Anti-Ostwald ripening etc.Various techniques for characterizing single-atom catalysts(SACs)are described in detail.The utilization of individual atoms in various photocatalytic reactions and their mechanisms of action in different reactions are explained.The purpose of this review is to introduce single-atom synthesis methods,characterization techniques,specific catalytic action and their applications in the direction of photocatalysis,and to provide a reference for the industrialization of photocatalytic single-atoms,which is currently impossible,in the hope of promoting further development of photocatalytic single-atoms.

Identification of new aptamer BC-3 targeting RPS7 from rapid screening for bladder carcinoma

Aptamers,short single DNA or RNA oligonucleotides,have shown immense application potential as molecular probes for the early diagnosis and therapy of cancer.However,conventional cell-SELEX technologies for aptamer discovery are time-consuming and laborious.Here we discovered a new aptamer BC-3 by using an improved rapid X-Aptamer selection process for human bladder carcinoma,for which there is no specific molecular probe yet.We show that BC-3 exhibited excellent affinity in bladder cancer cells but not normal cells.We demonstrate that BC-3 displayed high selectivity for tumor cells over their normal counterparts in vitro,in mice,and in patient tumor tissue specimens.Further endocytosis pathway analysis revealed that BC-3 internalized into bladder cancer cells via clathrin-mediated endocytosis.Importantly,we identified ribosomal protein S7(RPS7)as the binding target of BC-3 via an integrated methodology(mass spectrometry,colocalization assay,and immunoblotting).Together,we report that a novel aptamer BC-3 is discovered for bladder cancer and its properties in the disease are unearthed.Our findings will facilitate the discovery of novel diagnostic and therapeutic strategies for bladder cancer.

Evaluation of skin barrier function based on skin dermoscopic features in patients with rosacea

To the Editor:Rosacea is a common chronic inflammatory skin disease with typical manifestations such as flushing,erythema,papules,pustules,and phymatous changes.[1]It has been indicated that the resulting abnormal skin barrier structure and function was associated with the etiology and pathological process of rosacea.[2]Transepidermal water loss(TEWL)and stratum corneum hydration(SCH)are commonly used to evaluate skin barrier function and must be measured using specific instruments,such as the Cutometer MPA 580(Courage&Khazaka Electronic GmbH,Cologne,Germany)and GPSkin Barrier(GPOWER Inc.,Seoul,South Korea),which inter-correlate well.[3]However,these instruments are not available to most dermatologists.Dermoscopy has been incorporated into the clinical practice of most dermatologists.Practically,dermoscopy is more accessible to clinical dermatologists than skin barrier measure instruments.

Catalytic Hydrogenation of Acetic Acid to Acetaldehyde: Synergistic Effect of Bifunctional Co/Ce-Fe Oxide Solid Solution Catalysts

The large-scale industrial production of acetic acid (HAc) from carbonylation of methanol has enabled intense research interest from direct hydrogenation of HAc to acetaldehyde (AA).Herein,a series of cerium-iron oxide solid solution supported metallic cobalt catalysts were prepared by modified sol-gel method and were applied in gas-phase hydrogenation of HAc to AA.A synergistic effect between the hydrogenation metal cobalt and Ce-Fe oxide solid solution is revealed.Specifically,oxygen vacancies provide the active sites for adsorption of HAc,while highly uniformly dispersed metallic Co adsorbs H2 and activates the reduction of HAc into AA.Moreover,the metallic Co can also assist the cyclical conversion between Fe3+/Fe2+ and Ce3+/Ce4+ on the surface of Ce1.xFexO2-δ supports.The unique effect substantially enhances the ability of the support material to rapidly capture oxygen atoms from HAc.It is found that the catalyst of 5% Co/Ce0.8Fe0.2O2-δ with the highest concentration of oxygen vacancy presents the best catalytic performance (i.e.acetaldehyde yield reaches 49.9%) under the optimal reaction conditions (i.e.623 K and H2 flow rate =10 mL/min).This work indicates that the Co/Ce-Fe oxide solid solution catalyst can be potentially used for the selective hydrogenation from HAc to AA.The synergy between the metallic Co and Ce1-xFexO2-δ revealed can be extended to the design of other composite catalysts.

Single-molecule DNA logic nanomachines based on origami

Nowadays,it is a truism that chemists,bioengineers and others must be schooled in cell and molecular biology,including knowledge of the cellular,elemental and molecular building blocks of living systems.Inspired by exquisite and efficient biomolecular machines in living cells,such as ATPases that catalyze the decomposition of ATP into ADP and free phosphate ion,researchers representing multiple disciplines are actively engaged in developing artificial nanostructures with well-defined geometry and nanoscale addressability.A successful outcome of these studies could lead to the development and clinical application of smart molecular machines for the drug delivery of theranostics in vivo.

Visible light-driven photocatalysis of W,N co-doped TiO_2

W, N co-doped TiO2 nanoparticles were synthesized by a sol-gel method. The prepared samples were characterized by X-ray diffraction （XRD）, field emission scanning electron microscopy （FE-SEM）, trans- mission electron microscopy （TEM）, Fourier transform infrared spectroscopy （FT-1R）, X-ray photoelectron spectroscopy （XPS） and diffuse reflectance spectrophotometry （DRS）. The results showed that the co- doped photocatalysts were essentially uniform spherical particles with the smallest particle size of 22.5 nm. Compared to un-doped TiO2, N-TiO2 and P-25, the absorption edge of the W, N co-doped TiO2 shifted to longer wavelength and its photocatalytic activity for degradation of methyl orange （MO） under Xe-lamp （350W） was higher.

DNA aptamer S11e recognizes fibrosarcoma and acts as a tumor suppressor

Fibrosarcoma is a serious malignant mesenchymal tumor with strong invasiveness,high recurrence,and poor prognosis.Currently,surgical resection is the main treatment for fibrosarcoma.However,due to the lack of specific biomarkers,the inability to accurately diagnose fibrosarcoma can lead to sub-optimal surgical outcomes and decreased survival.Here,we seek to address this translational barrier and we show that DNA aptamer S11e was able to recognize fibrosarcoma cells(HT1080)but not human embryonic lung fibroblast cells with Kd values in the nanomolar range.In addition,we found that S11e discerned tumors in HT1080 xenograft mouse models and tumor tissues from fibrosarcoma patients.Furthermore,we demonstrated that S11e internalized into HT1080 cells independent of the lysosome pathway and located in mitochondria.Moreover,we revealed that S11e promoted the apoptosis of HT1080 cells and inhibited HT1080 cell migration.Finally,we investigated the biologically functional cellular target of S11e using a mass spectrometry approach,and identified that Diablo/SMAC protein is a cellular binding protein of S11e,by interacting to which S11e inhibited HT1080 cell migration and invasion.Taken together,these results provide the evidence that S11e may be useful for early diagnosis,targeted therapy,and prognostication of fibrosarcoma.