Br-Doped BiOCl Nanosheet Exposed (001) Facet: Surface Oxygen Vacancy and Directed Electron Flow Boosting the Photocatalytic Performance.

The defective BiOCl nanosheet exposed (001) facet with favorable photocatalytic performance was designed. The surface microstructure analysis and theoretical calculation certified the dominant exposed (001) facet and rich surface oxygen defects of Br--doped BiOCl (B-6) nanosheets. The energy level structure analysis indicates that the band gap can be narrowed and the light absorption range can be widened by introducing Br- to BiOCl, and the presence of defective energy levels increases the photogenerated carrier transfer efficiency. Moreover, the doping of Br- in BiOCl promotes the directional flow of electrons to the surface of B-6, which improves the photocatalytic performance of the sample. Thus, the Br--doped BiOCl can degrade 96.5% RhB within 6 min under visible-light irradiation with high apparent reaction rate constants of 0.51 min-1, exhibiting the strongest photocatalytic degradation performance. This work provides guidance for the preparation of Bi-based photocatalysts with excellent performance.

Tools and techniques for the discovery of therapeutic aptamers: recent advances.

INTRODUCTION: The pursuit of novel therapeutic agents for serious diseases such as cancer has been a global endeavor. Aptamers characteristic of high affinity, programmability, low immunogenicity, and rapid permeability hold great promise for the treatment of diseases. Yet obtaining the approval for therapeutic aptamers remains challenging. Consequently, researchers are increasingly devoted to exploring innovative strategies and technologies to advance the development of these therapeutic aptamers. AREAS COVERED: The authors provide a comprehensive summary of the recent progress of the SELEX (Systematic Evolution of Ligands by EXponential enrichment) technique, and how the integration of modern tools has facilitated the identification of therapeutic aptamers. Additionally, the engineering of aptamers to enhance their functional attributes, such as inhibiting and targeting, is discussed, demonstrating the potential to broaden their scope of utility. EXPERT OPINION: The grand potential of aptamers and the insufficient development of relevant drugs have spurred countless efforts for stimulating their discovery and application in the therapeutic field. While SELEX techniques have undergone significant developments with the aid of advanced analysis instruments and ingeniously updated aptameric engineering strategies, several challenges still impede their clinical translation. A key challenge lies in the insufficient understanding of binding conformation and susceptibility to degradation under physiological conditions. Despite the hurdles, our opinion is optimistic. With continued progress in overcoming these obstacles, the widespread utilization of aptamers for clinical therapy is envisioned to become a reality soon.

Programming Affinity for Precise Tumor Recognition with Allosteric Nanosensing-Circles.

Although many smart probes for precise tumor recognition have been reported, the challenge of "on-target, off-tumor" remains. Therefore, we herein report the fabrication of a series of allosterically tunable DNA nanosensing-circles (NSCs). The recognition affinity of NSCs is programmed through sensitivity to tumor microenvironment (TME) hallmarks such as small molecules, acidity, or oncoproteins. Because of their special programming conditions and active targeting capabilities, NSCs can overcome the obstacles noted above, thus achieving precise tumor recognition. Results from in vitro analysis demonstrated that NSCs obtain their recognition ability through allosteric regulation after sensing TME hallmarks. Furthermore, in vivo imaging indicated that NSCs enable precise tumor imaging. These results demonstrate that our NSCs will be promising tools for precise tumor imaging and therapy.

Improvement of Luminescence Properties of Eulytite Single-Phase White Emitting Ca3Bi (PO4)3: Ce3+/Dy3+ Phosphor.

To reduce the issue of tri-primary color reabsorption, a new approach for single-phase phosphors as light-emitting diodes (LEDs) has been recommended. The structures, morphology, photoluminescence, thermal stability, and luminescence mechanism of a variety of Ca3Bi (PO4)3 (CBPO): Ce3+/Dy3+ phosphors were investigated. XRD characterization showed that all CBPO samples were eulytite structures. Furthermore, the energy transfer process from Ce3+ to Dy3+ in CBPO is systematically investigated in this work, and the color of light can be adjusted by changing the ratio of doped ions. Under UV light, energy is transferred from Ce3+-Dy3+ mainly through quadrupole-quadrupole interactions in the CBPO host, and doping with different Dy3+ concentrations tunes the emission color from blue to white. The thermal stability of the CBPO: 0.04Ce3+, 0.08Dy3+ samples is outstanding, and the CIE coordinates of the samples after emission have little effect with temperature, while their emission intensity at 423 K is as strong as that at room temperature, reaching 90%. The above results indicate that this CBPO material has great potential as a white light phosphor under near-UV excitation at the optimized concentration of Ce3+ and Dy3+.

Nitrogen-Doped Hierarchical Porous Carbon Derived from Coal for High-Performance Supercapacitor.

The surface properties and the hierarchical pore structure of carbon materials are important for their actual application in supercapacitors. It is important to pursue an integrated approach that is both easy and cost-effective but also challenging. Herein, coal-based hierarchical porous carbon with nitrogen doping was prepared by a simple dual template strategy using coal as the carbon precursor. The hierarchical pores were controlled by incorporating different target templates. Thanks to high conductivity, large electrochemically active surface area (483 m2 g-1), hierarchical porousness with appropriate micro-/mesoporous channels, and high surface nitrogen content (5.34%), the resulting porous carbon exhibits a high specific capacitance in a three-electrode system using KOH electrolytes, reaching 302 F g-1 at 1 A g-1 and 230 F g-1 at 50 A g-1 with a retention rate of 76%. At 250 W kg-1, the symmetrical supercapacitor assembled at 6 M KOH shows a high energy density of 8.3 Wh kg-1, and the stability of the cycling is smooth. The energy density of the symmetric supercapacitor assembled under ionic liquids was further increased to 48.3 Wh kg-1 with a power output of 750 W kg-1 when the operating voltage was increased to 3 V. This work expands the application of coal-based carbon materials in capacitive energy storage.

Constructing the quinonyl groups and structural defects in carbon for supercapacitor and capacitive deionization applications.

The structural defects and oxygen-containing functional groups of carbon materials as electrode materials for supercapacitors or capacitive deionization devices are critical to their electrochemical performance. The tuning of surface oxygen-containing functional groups and carbon defects during pyrolysis is key to achieve a high performance in ion storage. Herein, quinonyl-dominant defective porous carbon is prepared by a pyrolysis and cross-linking route using lavender stem and potassium acetate as precursor. Benefiting from the presence of abundant defect and surface quinonyl groups, porous carbon shows an ultra-high specific capacitance of 401 F g-1 (1 A g-1) and a high capacitance retention of 63% at a high current density of 100 A g-1 in a KOH solution. Meanwhile, as a capacitive deionization electrode material, it also exhibited a high adsorption capacity of 25.5 mg g-1 in 500 mg L-1 NaCl solution at 1.2 V. Theoretical density functional theory (DFT) calculation demonstrates that surface quinonyl groups and carbon defects can synergistically facilitate the adsorption of K+ and Na+ during the charge/discharge process. This work provides a new perspective for understanding the role of surface oxygen-containing groups and intrinsic defects of porous carbon materials in electrochemical energy storage and desalination applications.

Tuning the Zn2+ solvation structure in dual-salts hybrid aqueous electrolyte to stabilize the Zn metal anode.

Aqueous Zn-ion battery is expected to become a substitute for Li-ion battery due to its inherent safety, low cost, and environmental friendliness. Dendrite growth and side reaction problems during electroplating lead to its low Coulombic efficiency and unsatisfactory life, which greatly limits its practical application. Here, we propose a dual-salts hybrid electrolyte, which alleviates the above issues by mixing Zn(OTf)2 to ZnSO4 solution. Extensive tests and MD simulations have shown that the dual-salts hybrid electrolyte can regulate the solvation structure of Zn2+, facilitating uniform Zn deposition, and inhibiting side reactions and dendrite growth. Hence, the dual-salts hybrid electrolyte exhibits good reversibility in Zn//Zn batteries, which can provide a lifetime of more than 880 h at 1 mA cm-2 and 1 mAh cm-2. Moreover, the average Coulombic efficiency of Zn//Cu cells in hybrid system can reach 98.2% after 520 h, much better than that of 90.7% in pure ZnSO4 electrolyte and 92.0% in pure Zn(OTf)2 electrolyte. Benefiting from the fast ion exchange rate and high ion conductivity, Zn-ion hybrid capacitor in hybrid electrolyte also displays excellent stability and capacitive performance. This effective strategy for dual-salts hybrid electrolytes provides a promising direction for designing aqueous electrolytes for Zn-ion batteries.

Dual-Salt-Induced Hierarchical Porous Structure in a Carbon Sheet for High Performance Supercapacitors.

Porous carbon, one of the characteristic materials for electrochemical energy storage devices, has been paid wide-ranging attention. However, balancing the reconcilable mesopore volume with a large specific surface area (SSA) was still a challenge. Herein, a dual-salt-induced activation strategy was developed to obtain a porous carbon sheet with ultrahigh SSA (3082 m2 g-1), desirable mesopore volume (0.66 cm3 g-1), nanosheet morphology, and high surface O (7.87%) and S (4.0%) content. Hence, as a supercapacitor electrode, the optimal sample possessed a high specific capacitance (351 F g-1 at 1 A g-1) and excellent rate performance (holding capacitance up to 72.2% at 50 A g-1). Furthermore, the assembled zinc-ion hybrid supercapacitor also exhibited superior reversible capacity (142.7 mAh g-1 at 0.2 A g-1) and highly stable cycling (71.2 mAh g-1 at 5 A g-1 after 10,000 cycles with retention of 98.9%). This work was delivered a new possibility for the development of coal resources for the preparation of high performance porous carbon materials.

A versatile strategy for convenient circular bivalent functional nucleic acids construction.

Functional nucleic acids (FNAs), such as aptamers, nucleic acid enzymes and riboswitches play essential roles in various fields of life sciences. Tailoring of ingenious chemical moieties toward FNAs can enhance their biomedical properties and/or confer them with exogenic biological functions that, in turn, can considerably expand their biomedical applications, or even improve their clinical translations. Herein, we report the first example of a general chemical tailoring strategy that enables the divergent ligation of DNA sequences. By applying this technology, different types of aptamers and single-stranded nucleic acids of various lengths could be efficiently tailored to deliver the designed circular bivalent aptamers (CBApts) and cyclized DNA sequences with high yields. It is worth noting that CBApts exhibited significantly enhanced nuclease resistance, as well as considerably improved binding, targeting and tumor tissue enrichment abilities, which may pave the way for different investigations for biomedical purposes.

Hybrid nanoarchitectonics of coal-derived carbon with oxidation-induced morphology-selectivity for high-performance supercapacitor.

Coal-derived porous carbon with a large specific surface area is a common electrode material for supercapacitors. Its deep and branched micropores, dense bulk morphology and amorphous structure have greatly limited its practical applications. Herein, hybrid carbon materials were obtained from coal through oxidation followed by activation. The method allows tuning the morphology, porosity, structure, and the degree of graphitization. The pre-oxidation with KMnO4 can break raw coal into small hydrocarbon fragments, which deposit and grow on the surface of generated MnO during pyrolysis leading to hybrid carbon with mesoporous and graphitic nanostructures. Meanwhile, homogeneous etching of the carbon skeleton by the reaction intermediate of K2CO3 led to the formation of abundant active sites. Hence, the optimized sample exhibited a high capacitance of 333 F g-1 at 1 A g-1, an excellent rate capability with 58% capacitance retention at 100 A g-1 and superior cycle durability in a three-electrode system. Besides, an assembled symmetric two-electrode device displayed a high energy density of 8.9 Wh·kg-1 at 250 W·kg-1. This work proposed a facile and rational synthesis strategy by balancing the tradeoff between active sites and intrinsic conductivity and thus provided a new avenue for the value-added utilization of coal.

Homogeneous activation induced by bacterial cellulose nanofibers to construct interconnected microporous carbons for enhanced capacitive storage.

Porous carbons have been widely applied for capacitive energy storage, yet usually suffer from insufficient rate performance because of the sluggish ion transport kinetics in deep and multi-branched pores. Herein, we fabricated an interconnected microporous capacitive carbon (IMCC) by growing D (+)-glucosamine on bacterial cellulose (BC) nanofibers scaffold, followed by carbonization and activation. The BC nanofibers acted as a sacrificial template during pre-carbonization, facilitating the subsequent KOH permeation and homogeneous activation. By taking advantage of the interconnected microporous structure, the IMCC delivers a high capacitance of 302 F g-1 at 1 A g-1 and an excellent rate capability of 165 F g-1 at 100 A g-1 for aqueous supercapacitor, demonstrating its fast ion transport capability. Impressively, it also shows a superior gravimetric capacity of 177 mAh g-1 at 0.5 A g-1 and remains a high value of 72 mAh g-1 at 20 A g-1 as a cathode material for Zn-ion hybrid capacitor. This facile and cost-effective design strategy exhibits a great potential to construct carbohydrates-derived interconnected microporous carbon materials for high-rate energy storage.

A pH-Responsive Covalent Nanoscale Device Enhancing Temporal and Force Stability for Specific Tumor Imaging.

Approaches to DNA probe-mediated precision medicine have been extensively explored for the diagnosis and treatment of diverse types of cancer. Despite this, simple nanoscale devices with the required recognition specificity and sensitivity for clinical application have remained elusive until now. Here, we report a pH-driven covalent nanoscale device that integrates pH-responsive, switchable structure and proximity-driven covalent cross-linking. A tumor acidic, pH-driven mechanism eliminates "on-target, off-tumor" nonspecific recognition. By manipulating covalent binding to target molecule on the cell surface, this nanodevice avoids binding-then-shedding to improve the sensitivity of tumor recognition. We envision that this pH-driven covalent nanoscale device will inspire more clinical applications toward specific, long-term tumor imaging in the cancer microenvironment.

A Dual-Targeting Circular Aptamer Strategy Enables the Recognition of Different Leukemia Cells with Enhanced Binding Ability.

Currently, the broad use of monovalent aptamers in oncology faces challenges, including insufficient recognition and internalization caused by a finite number of receptors on the cell surface, as well as a confined recognition spectrum. Herein, we describe the development of a dual-targeting circular aptamer (DTCA) that can recognize two different biomarkers on living cells to augment aptamer-receptor interactions, thus enhancing recognition of the target cells. This improvement not only boosts binding and internalization abilities, but also expands the recognition spectrum of these aptamers to different leukemia cells. Moreover, the stability of DTCA in serum can be significantly improved by an enzyme-promoted terminal ligation strategy. The chemical incorporation of 5-fluorodeoxyuridine into DTCA resulted in a pharmaceutically functional aptamer that exhibited excellent selectivity, as demonstrated by its high cytotoxicity against target cancer cells, but not to normal cells. The superiority of our newly developed strategy was further highlighted by its precise tumor-imaging capability.

Functional Aptamer-Embedded Nanomaterials for Diagnostics and Therapeutics.

In the past decades, various nanomaterials with unique properties have been explored for bioapplications. Meanwhile, aptamers, generated from the systematic evolution of ligands by exponential enrichment technology, are becoming an indispensable element in the design of functional nanomaterials because of their small size, high stability, and convenient modification, especially endowing nanomaterials with recognition capability to specific targets. Therefore, the incorporation of aptamers into nanomaterials offers an unprecedented opportunity in the research fields of diagnostics and therapeutics. Here, we focus on recent advances in aptamer-embedded nanomaterials for bioapplications. First, we briefly introduce the properties of nanomaterials that can be functionalized with aptamers. Then, the applications of aptamer-embedded nanomaterials in cellular analysis, imaging, targeted drug delivery, gene editing, and cancer diagnosis/therapy are discussed. Finally, we provide some perspectives on the challenges and opportunities that have arisen from this promising area.

Aptamer Enables Consistent Maytansine Delivery through Maintaining Receptor Homeostasis for HER2 Targeted Cancer Therapy.

Although the extensive clinical use of the ADC trastuzumab-DM1(T-DM1) for human epidermal growth factor receptor 2 (HER2) targeted cancer therapy, many patients who initially respond to T-DM1 treatment eventually met the insufficient efficacy issue, which is partly attributed to the decreased amount of surface HER2 caused by HER2 degradation in target cells. In our study, we have engineered a HER2 targeted DNA aptamer-DM1 conjugate (HApDC) that can maintain the homeostasis of surface HER2 on the target cancer cell. These conclusions are supported by determining the efficient internalization of HApDC into HER2 overexpressed BT474 and SKBR3 cancer cell lines and by identifying the membranal HER2 level on HApDC-treated BT474 cells. Consistent with the impressive in vitro properties of our newly developed anticancer agent, DM1 could precisely be delivered to the tumor tissue in BT474 xenografted mouse models, because of the specific recognition of aptamer. Noteworthy, HApDC exhibited excellent in vivo tumor inhibition function with much lower healthy organ toxicity, compared with the free drug, which might be explained by the persistently targeted DM1 delivery, which is attributed to the remaining HER2 levels on cells.

Molecularly Engineering Triptolide with Aptamers for High Specificity and Cytotoxicity for Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) lacks three important receptors, ER, PR, and HER2. It is more aggressive and more likely to relapse after treatment, thus has been identified as one of the most malignant breast cancer types. The development of efficient targeted TNBC therapy is an important research topic in TNBC treatment. We report the development of a new aptamer-drug conjugate (ApDC), AS1411-triptolide conjugate (ATC), as targeted therapy for the treatment of TNBC with high efficacy. The conjugate possesses excellent specificity and high cytotoxicity against the MDA-MB-231 cell line. The advantages of our newly invented ATC are further highlighted by its excellent in vivo anti-TNBC efficacy and negligible side effects toward healthy organs.

Dispersal and Transmission of Avian Paramyxovirus Serotype 4 among Wild Birds and Domestic Poultry.

Avian paramyxovirus serotype 4 (APMV-4) is found sporadically in wild birds worldwide, and it is an economically important poultry pathogen. Despite the existence of several published strains, very little is known about the distribution, host species, and transmission of APMV-4 strains. To better understand the relationships among these factors, we conducted an APMV-4 surveillance of wild birds and domestic poultry in six provinces of China suspected of being intercontinental flyways and sites of interspecies transmission. APMV-4 surveillance was conducted in 9,160 wild birds representing seven species, and 1,461 domestic poultry in live bird markets (LMBs) from December 2013 to June 2016. The rate of APMV-4 isolation was 0.10% (11/10,621), and viruses were isolated from swan geese, bean geese, cormorants, mallards, and chickens. Sequencing and phylogenetic analyses of the 11 isolated viruses indicated that all the isolates belonging to genotype I were epidemiologically connected with wild bird-origin viruses from the Ukraine and Italy. Moreover, chicken-origin APMV-4 strains isolated from the LBMs were highly similar to wild bird-origin viruses from nearby lakes with free-living wild birds. In additional, a hemagglutination-negative APMV-4 virus was identified. These findings, together with recent APMV-4 studies, suggest potential virus interspecies transmission between wild birds and domestic poultry, and reveal possible epidemiological intercontinental connections between APMV-4 transmission by wild birds.

A Raf kinase inhibitor demonstrates antiviral activities both in vitro and in vivo against different genotypes of virulent Newcastle disease virus.

Newcastle disease (ND) is still one of the major plagues of birds worldwide. Combat actions are limited to vaccines, highlighting the urgent need for new and amply available antiviral drugs. Previous results have shown that Newcastle disease virus (NDV) downregulates the intracellular Raf kinase inhibitor protein (RKIP) expression for efficient replication, suggesting that this molecular may be a suitable target for antiviral intervention. In the present work, we investigated whether or not the Raf kinase inhibitor V (RKIV), which functions in the same way as RKIP by targeting the intracellular Raf kinase, is able to suppress the propagation of enzootic virulent NDV in vitro and in vivo. In vitro antiviral activity of RKIV was assessed by cell-based assay, and in vivo activity was determined in the chicken model. Our results clearly showed that RKIV treatment protected the cells from NDV-induced CPE with the effective concentrations on nM level, and inhibited virus replication in the lungs of infected chickens in a dose-dependent manner and protected chickens from the lethal infection by NDV. Thus, we conclude that the Raf kinase inhibitor compound RKIV, by inhibiting the host cellular target Raf kinase, might be very promising as a new class of antivirals against the enzootic virulent NDV infection.

High Genetic Diversity of Newcastle Disease Virus in Wild and Domestic Birds in Northeastern China from 2013 to 2015 Reveals Potential Epidemic Trends.

Newcastle disease (ND), caused by the virulent Newcastle disease virus (NDV), is one of the most important viral diseases of birds globally, but little is currently known regarding enzootic trends of NDV in northeastern China, especially for class I viruses. Thus, we performed a surveillance study for NDV in northeastern China from 2013 to 2015. A total 755 samples from wild and domestic birds in wetlands and live bird markets (LBMs) were collected, and 10 isolates of NDV were identified. Genetic and phylogenetic analyses showed that five isolates from LBMs belong to class I subgenotype 1b, two (one from wild birds and one from LBMs) belong to the vaccine-like class II genotype II, and three (all from wild birds) belong to class II subgenotype Ib. Interestingly, the five class I isolates had epidemiological connections with viruses from southern, eastern, and southeastern China. Our findings, together with recent prevalence trends of class I and virulent class II NDV in China, suggest possible virus transmission between wild and domestic birds and the potential for an NDV epidemic in the future.