Silencing of long non-coding RNA DLX6-AS1 weakens neuroblastoma progression by the miR-513c-5p/PLK4 axis.

Emerging evidence has demonstrated the crucial roles of long noncoding RNAs in human cancers, including neuroblastoma (NB). DLX6 antisense RNA 1 (DLX6-AS1) has been identified as an oncogenic driver in NB. However, the mechanisms of DLX6-AS1 in NB progression are not fully understood. Our data showed that DLX6-AS1 was significantly overexpressed in NB tissues and cells. Moreover, DLX6-AS1 silencing repressed NB cell viability, colony formation, migration, and invasion, and promoted cell cycle arrest and apoptosis in vitro, as well as decreased tumor growth in vivo. Mechanistically, DLX6-AS1 operated as a miR-513c-5p sponge. MiR-513c-5p mediated the regulation of DLX6-AS1 on NB cell malignant progression in vitro. PLK4 was a target of miR-513c-5p- and DLX6-AS1-controlled PLK4 expression via sponging miR-513c-5p. Furthermore, the suppressive effect of miR-513c-5p overexpression on NB cell malignant progression in vitro was reversed by PLK4 upregulation. Our findings identified a novel regulatory mechanism, the DLX6-AS1/miR-513c-5p/PLK4 axis, in NB progression, highlighting a strong rationale for developing DLX6-AS1 as a new target for NB management.

Click-Type Protein-DNA Conjugation for Mn2+ Imaging in Living Cells.

A click-type protein-DNA conjugation, named as MnDDC (Mn2+-activated DCV-DNA conjunction), is presented, where DCV (rep protein of duck circovirus) and its target DNA work as the modular blocks to rapidly and effectively generate Mn2+-dependent and site-specific protein-DNA linkage. On the basis of MnDCC, a fluorescent Mn2+ biosensor composed of DCV and a molecular beacon, was developed for rapid sensing of Mn2+ within 2 min with nanomolar sensitivity. Using the proposed biosensor, not only analysis of Mn2+ in real samples (e.g., serum and food), but also wash-free fluorescent imaging of Mn2+ in extracellular environment and cytoplasm have been achieved. Moreover, the MnDDC-based sensor was proved to be a powerful tool for visualization of Mn2+ during exploration of the associated cytotoxicity in living neural cells, which is helpful to reveal the cellular responses toward the disordered homeostasis of Mn2+ in both extracellular and intracellular microenvironments.

Two new compounds from the roots of Scrophularia ningpoensis and their anti-inflammatory activities.

Aiming to investigate the bioactive constituents with anti-inflammatory activity from the roots of Scrophularia ningpoensis, two new compounds (1 and 3) were isolated from the extract of the roots of the plant. Their structures were elucidated on the basis of spectral analyses (UV, IR, NMR, and MS spectroscopy), as well as experimental and calculated electronic circular dichroism (ECD) analyses. All of the isolates were tested for their anti-inflammatory properties in terms of suppressing the production of NO in lipopolysaccharide-induced BV2 cells. Compound 2 exhibited stronger anti-inflammatory effects (77.65%) than the positive control curcumin (69.75%) at 10 µM.

Homogeneous electrochemical immunoassay of aflatoxin B1 in foodstuff using proximity-hybridization-induced omega-like DNA junctions and exonuclease III-triggered isothermal cycling signal amplification.

A new homogeneous electrochemical immunosensing platform was designed for sensitive detection of aflatoxin B1 (AFB1) in foodstuff. The system consisted of anti-AFB1 antibody labeled DNA1 (Ab-DNA1), AFB1-bovine serum albumin (BSA)-conjugated DNA2 (AFB1-DNA2), and methylene blue functionalized hairpin DNA. Owing to a specific antigen-antibody reaction between anti-AFB1 and AFB1-BSA, the immunocomplex formed assisted the proximity hybridization of DNA1 with DNA2, thus resulting in the formation of an omega-like DNA junction. Thereafter, the junction opened the hairpin DNA to construct a new double-stranded DNA, which could be readily cleaved by exonuclease III to release the omega-like DNA junction and methylene blue. The dissociated DNA junction could repeatedly hybridize with residual hairpin DNA molecules with exonuclease III-based isothermal cycling amplification, thereby releasing numerous free methylene blue molecules into the detection solution. The as-produced free methylene blue molecules could be captured by a negatively charged indium tin oxide electrode, each of which could produce an electronic signal within the applied potentials. On introduction of target AFB1, the analyte competed with AFB1-DNA2 for the conjugated anti-AFB1 on the Ab-DNA1, subsequently decreasing the amount of omega-like DNA junctions formed, hence causing methylene blue labeled hairpin DNA to move far away from the electrode surface. Under optimal conditions the detectable electrochemical signal decreased with increasing amount of target AFB1 in a dynamic working range of 0.01-30 ng mL-1 with a detection limit of 4.8 pg mL-1. In addition, the precision and reproducibility of this system were acceptable. Finally, the method was further evaluated for analysis of naturally contaminated or AFB1-spiked peanut samples, giving results that matched well with those obtained with a commercial AFB1 ELISA kit.

Two cases of Kawasaki disease: Clinical characteristics and onset of fever and gastrointestinal symptoms.

BACKGROUND: Kawasaki disease (KD) is a prevalent form of systemic vasculitis that can damage various organs and systems in children. Typical KD is not difficult to diagnose in clinical practice. In recent years, it has been shown that an increasing number of children do not satisfy the diagnostic criteria for typical KD. This condition is known as incomplete KD (IKD). It is challenging to promptly diagnose and treat such children in clinical practice. CASE DESCRIPTION: A 10-year-old girl was admitted to the hospital due to fever and abdominal pain. She presented with shock symptoms. An enhanced abdominal computed tomography scan revealed intestinal pneumatosis, effusion, and gallbladder enlargement, indicating intestinal obstruction. Due to the poor outcome following an emergency laparoscopic cholecystectomy, IKD was suspected. A 3-month-old male pediatric patient was admitted to the hospital due to a fever. Patchy, congestive rashes formed on the patient's body as KD progressed. IKD was suspected based on the clinical signs of fever, rash, and hyperemia of the lips. The two patients were then treated with human immunoglobulin and aspirin treatment. The prognosis for the two children was favorable following prompt treatment. CONCLUSION: Due to the fact that IKD is frequently misdiagnosed, it is vital to (1) improve the patient prognosis for the early identification of children with KD with prolonged fever and anti-infection failure as the initial manifestation and (2) perform timely diagnosis and comprehensive treatment.

Assessment of Interaction Behaviors of Cement-Emulsified Asphalt Based on Micro-Morphological and Macro-Rheological Approaches.

Cement emulsified asphalt composite binder (CEACB) plays a determining role in the construction of cold recycled asphalt pavements. Understanding the interaction behaviors of cement-emulsified asphalt is very essential to promote the serviceability of CEACB. The objective of this study was to explore the interaction behaviors and mechanism of cement-emulsified asphalt associated with microstructural characteristics and to assess the interaction ability of cement-emulsified asphalt by performing macro-rheological measurements. Firstly, the physico-chemical interaction of cement-emulsified asphalt was qualitatively discussed by analyzing the difference of characteristic peaks based on Fourier transform infrared (FTIR) spectrometer. Secondly, the micro-morphological evolution behaviors of CEACB attributing to the cement-emulsified asphalt interaction were investigated by using a fluorescence microscope (FM) and laser particle size analyzer (LPSA). Thirdly, the microstructural characteristics of CEACB were studied by observing the spatial network structure through the scanning electron microscopy (SEM). Finally, the macro-rheological index based on dynamic rheological shear (DSR) test was proposed to evaluate the interaction ability of cement-emulsified asphalt. The results show that the cement-emulsified asphalt interaction is merely a physical blending process due to the occurrence of no new characteristic peaks in the FTIR spectrum except for cement hydration products. The cement-emulsified asphalt interaction in early-age CEACB could be reflected by the aggregation process among asphalt droplets and the adsorption action of cement particles to asphalt droplets. A reasonable ratio of cement to emulsified asphalt could promote the formation of the denser spatial network structure of CEACB along with cement hydration products growing and interweaving with asphalt films. The K-B-G* index based on macro-rheological properties of CEACB with full consideration of cement hydration process is very suitable for evaluating the interaction ability of cement-emulsified asphalt under the condition of different cement proportions and curing time. The research would provide the support for understanding the natural properties of CEACB and promote the improvement of the mechanical performance of cold recycled asphalt pavements.

Genetic Characterization of Enterobacter hormaechei Co-Harboring bla NDM-1 and mcr-9 Causing Upper Respiratory Tract Infection.

Purpose: With the spread of multiple drug-resistant bacteria, bla NDM-1 and mcr-9 have been detected in various bacteria worldwide. However, the simultaneous detection of bla NDM-1 and mcr-9 in Enterobacter hormaechei has been rarely reported. This study identified an E. hormaechei strain carrying both bla NDM-1 and mcr-9. We investigated the genetic characteristics of these two resistance genes in detail, elucidating various potential mechanisms by which they may be transmitted. Methods: Bacterial genomic features and possible origins were assessed by whole-genome sequencing (WGS) with Illumina and PacBio platforms and phylogenetic analysis. Subsequent investigations were performed, including antimicrobial susceptibility testing and multilocus sequence typing (MLST). Results: We isolated an E. hormaechei strain DY1901 carrying both bla NDM-1 and mcr-9 from the sputum sample. Susceptibility testing showed that the isolate was multidrug-resistant. Multiple antibiotic resistance genes and virulence genes are widely distributed in DY1901. S1-PFGE, Southern blotting, and plasmid replicon typing showed that DY1901 carried four plasmids. The plasmid carrying mcr-9 was 259Kb in size and belonged to IncHI2, while the plasmid carrying bla NDM-1 was 45Kb in length and belonged to IncX3. Conclusion: The E. hormaechei strain isolated in this study has a broad antibiotic resistance spectrum, posing a challenge to clinical treatment. Plasmids carrying mcr-9 are fusion plasmids, and those taking NDM are widely disseminated in China, suggesting that we should conduct routine genomic surveillance on such plasmids to curb the spread of drug-resistant bacteria in the region.

Coaxial heterogeneous structure of TiO2 nanotube arrays with CdS as a superthin coating synthesized via modified electrochemical atomic layer deposition.

We report the fabrication and characterization of CdS/TiO(2) nanotube-array coaxial heterogeneous structures. Such structures may potentially be applied in various photocatalytic fields, such as water photocatalytic decomposition and toxic pollutant photocatalytic degradation. Thin films of CdS are conformally deposited onto TiO(2) nanotubes using a modified method of electrochemical atomic layer deposition. We propose that such nanostructured electrodes can overcome the poor absorption and high charge-carrier recombination observed with nanoparticulate films. The practical electrochemical deposition technique promotes the deposition of CdS onto the TiO(2) tube walls while minimizing deposition at the tube entrances, thus preventing pore clogging. The coaxial heterogeneous structure prepared by the new electrochemical process significantly enhances CdS/TiO(2) and CdS/electrolyte contact areas and reduces the distance that holes and electrons must travel to reach the electrolyte or underlying conducting substrate. This results in enhanced photon absorption and photocurrent generation. The detailed synthesis process and the surface morphology, structure, elemental analysis, and photoelectrochemical properties of the resulting films with the CdS/TiO(2) nanotube-array coaxial heterogeneous structure are discussed. In comparison with a pure TiO(2) nanotube array, a 5-fold enhancement in photoactivity was observed using the coaxial heterogeneous structure. This methodology may be useful in designing multijunction semiconductor materials for coating of highly structured substrates.

Biomineralization synthesis of a near-infrared fluorescent nanoprobe for direct glucose sensing in whole blood.

A near-infrared (NIR) fluorescent nanoprobe that enables to circumvent the interference of background absorption and fluorescence in whole blood was developed for the direct sensing of blood glucose. Here, NIR fluorescent protein (iRFP) and glucose oxidase (GOx) were collectively deployed as the templates for the biomineralization of Mn2+ to prepare a NIR fluorescent nanoprobe (iRFP-GOx-MnO2 nanoparticles, iRGMs), in which the fluorescence of iRFP was effectively quenched by MnO2via energy transfer. When the iRGMs were mixed with whole blood samples, GOx can convert blood glucose into gluconic acid, as well as H2O2, which will reduce MnO2 and decompose the iRGMs. As a result, the NIR fluorescence of iRFPs was restored, providing a fluorometric assay for the direct detection of blood glucose. Owing to the high efficiency of the cascade reaction and the low background interference of the NIR fluorescence signal, accurate and rapid analysis of the glucose levels in whole blood samples was achieved using the iRGMs. Moreover, an iRGM-based paper device that only requires 5 microliters of samples was also demonstrated in the direct assay of blood glucose without any pretreatment, affording an alternative approach for the accurate monitoring of blood glucose levels.

Amplified impedimetric immunosensor based on instant catalyst for sensitive determination of ochratoxin A.

A new impedimetric immunosensor for the fast determination of ochratoxin A (OTA) in food samples was developed based on the instant catalyst as enhancer. Initially, the signal tags were prepared via co-immobilization of anti-OTA antibody and amine-terminated dendrimer (PAMAM) on the graphene oxide nanosheets through the covalent interaction, which were utilized as a good platform for combining manganese ion (anti-OTA-GO-PAMAM-Mn(2+)). Upon target OTA introduction, a competitive-type immunoreaction was implemented between the analyte and the immobilized OTA-BSA on the electrode for the anti-OTA antibody on the graphene oxide nanosheets labels. After a competitive immunoassay format, the anti-OTA-GO-PAMAM-Mn(2+) were captured onto the electrode surface, which could induce the in situ formation of MnO2via classical redox reaction between Mn(2+) and KMnO4 on the immunesensing platform. Moreover, the generated MnO2 nanoparticles act as efficient catalyst could catalyze the 4-chloro-1-naphthol (4-CN) oxidation without H2O2 to generate an insoluble precipitation on the platform. Under the optimal conditions, the instant catalyst based impedimetric immunosensor displayed a wide dynamic working range between 0.1pgmL(-1) and 30ngmL(-1). The detection limit (LOD) of the assay was 0.055pgmL(-1). The developed method exhibited high selectivity and can be used for the determination of OTA in real red wine samples.

Novel glucometer-based immunosensing strategy suitable for complex systems with signal amplification using surfactant-responsive cargo release from glucose-encapsulated liposome nanocarriers.

Methods based on surfactant-responsive controlled release systems of cargoes from nanocontainers have been developed for bioanalytical applications, but most were utilized for drug delivery and a few reports were focused on immunoassays. Herein we design an in situ amplified immunoassay protocol for high-efficient detection of aflatoxins (aflatoxin B1, AFB1 used in this case) based on surfactant-responsive cargo release from glucose-encapsulated liposome nanocarriers with sensitivity enhancement. Initially, biotinylated liposome nanocarrier encapsulated with glucose was synthesized using a reverse-phase evaporation method. Thereafter, the nanocarrier was utilized as the signal-generation tag on capture antibody-coating microplate through classical biotin-avidin linkage after reaction with biotinylated detection antibody. Upon addition of buffered surfactant (1X PBS-Tween 20 buffer) into the medium, the surfactant immediately hydrolyzed the conjugated liposome, and released the encapsulated glucose from the nanocarriers, which could be quantitatively determined by using a low-cost personal glucometer (PGM). The detectable signal increased with the increment of target analyte. Under the optimal conditions, the assay could allow PGM detection toward target AFB1 as low as 0.6 pg mL(-1) (0.6 ppt). Moreover, the methodology also showed good reproducibility and high specificity toward target AFB1 against other mycotoxins and proteins, and was applicable for quantitatively monitoring target AFB1 in the complex systems, e.g., naturally contaminated/spiked peanut samples and serum specimens, with the acceptable results. Taking these advantages of simplification, low cost, universality and sensitivity, our design provides a new horizon for development of advanced immunoassays in future point-of-care testing.