Asymmetric Hairpins DNA Encapsulated Silver Nanoclusters for In Situ Fluorescence Imaging of Fusion Gene Isoforms in Bone Marrow.

Rapid and accurate imaging of the BCR/ABL fusion gene isoforms (e.g., e13a2, e14a2 and co-expression type) of chronic myeloid leukemia (CML) is of vital importance to first-line drug selection, but there is no assay that meets clinical needs (e.g., clinical kits > 18 h without isoforms information). Herein, an in situ imaging platform is developed for the rapid and accurate detection of CML fusion gene isoforms using asymmetric sequence-enhanced hairpins DNA encapsulated silver nanoclusters (ADHA) and catalyzed hairpin assembly (CHA). The specific detection of e13a2 and e14a2 fusion gene isoforms with detection limits of 19.2 am (11.558 copies µL-1 ) and 32.56 am (19.601 copies µL-1 ) in one-pot is achieved. The feasibility of the developed assay for real-world applications are demonstrated by one-step fluorescence imaging (40 min) of e13a2, e14a2 and co-expression type in bone marrow quantitatively (International Standard: 15.66%-168.878%) and further validated by cDNA-sequencing. This work suggests that the developed imaging platform holds great potential for rapid identification of the fusion gene isoforms and isoform related treatment monitoring.

Kinetic Analysis on Spontaneous Combustion of Pressurized Hydrogen in Tubes.

Highly pressurized hydrogen storage is considered as one of the best methods currently due to its economic performance. However, the highly pressured storage technology is facing the threat of spontaneous combustion of high-pressure leakage, and there is still a lack of research on the kinetics of chemical reactions in the spontaneous combustion process, which greatly restricts the development of safe and efficient hydrogen-storage technology. Therefore, in this study, a three-dimensional simulation using the open-source packages OpenFOAM with a detailed kinetic model is proposed to analyze the hydrogen spontaneous combustion process in tubes. Subsequently, the effects and mechanisms of release pressures and tube geometry parameters are studied by means of kinetic simulation. The results show that the magnitude of the release pressure and tube diameter and length directly affects the spontaneous ignition and the location. In order to get more deep insights into the pressurized hydrogen release, reaction path analysis is performed. Three different hydrogen-consumed channels are found by reaction path analysis. The special performances found in spontaneous ignition with different release pressures and tube geometry parameters are caused by the competition between the chain-terminating channel and chain-branching channel. This work provides novel insights to understand the hydrogen spontaneous combustion process and enhances the theoretical basis for seeking safe hydrogen-storage means.

One-Pot Identification of BCR/ABLp210 Transcript Isoforms Based on Nanocluster Beacon.

The BCR/ABLp210 fusion gene is a classic biomarker of chronic myeloid leukemia, which can be divided into e13a2 and e14a2 isoforms according to different breakpoints. These two isoforms showed distinct differences in clinical manifestation, treatment effect, and prognosis risk. Herein, a strategy based on nanocluster beacon (NCB) fluorescence was developed to identify the e13a2 and e14a2 isoforms in one-pot. Because the fluorescence of AgNCs can be activated when they are placed in proximity to the corresponding enhancer sequences, thymine-rich (T-rich) or guanine-rich (G-rich). In this work, we explored an ideal DNA-AgNCs template as an excellent molecular reporter with a high signal-to-noise ratio. After recognition with the corresponding isoforms, the AgNCs can be pulled closer to the T-rich or G-rich sequences to form a three-way junction structure and generate fluorescence with corresponding wavelengths. Therefore, by distinguishing the corresponding wavelengths of AgNCs, we successfully identified two isoforms in one tube with the limitation of 16 pM for e13a2 and 9 pM for e14a2. Moreover, this strategy also realized isoform identification in leukemia cells and newly diagnosed CML patients within 40 min, which provides a powerful tool to distinguish fusion gene subtypes at the same time.

Light up multiple protein dimers on cell surface based on proximity-induced fluorescence activation of DNA-templated sliver nanoclusters.

Efficient and multiple analysis of receptor protein dimers is highly necessary, due to their important role in the occurrence and development of cancer. Herein, we report a turn-on strategy to visualize human epidermal growth factor receptor (HER) dimers on cell surfaces. By taking advantages of specific aptamer recognition and proximity-induced fluorescence activation of DNA-templated sliver nanoclusters (DNA/AgNCs) by guanine (G)-rich sequence, we attached the two kind of DNA/AgNCs sequence with different fluorescence properties to the corresponding HER aptamer to form aptamer-functionalized AgNCs probes, and attached G-rich sequence to the corresponding HER aptamer as enhancer. In the presence of protein dimers, after aptamer specific recognition and binding, it will draw the dark AgNCs probes close to the G-rich probes and then excite corresponding fluorescence. As a result, this approach has successfully realized imaging of HER2:HER2 homodimer and HER2:HER3 heterodimer at the same time, which was provided a new idea for the simultaneous detection of multiple HER2 dimers in situ. This AgNCs-based light up strategy provides a potential tool for further investigation of protein dimerization on cell surface, which is more conducive to the mechanism research, accurate classification and treatment of cancer.

Experimental Research on the Thermal Oxidation of Ventilation Air Methane in a Thermal Reverse Flow Reactor.

The thermal reverse flow reactor is an effective technical equipment for dealing with ventilation air methane, which has been causing a significant greenhouse effect. An experimental study on the thermal oxidation of ventilation air methane in a thermal reverse flow reactor was conducted. A mixture of domestic gas and ambient air was used to simulate ventilation air methane in the experiments, and the methane conversion efficiency was analyzed based on the concentration of combustion products determined by gas chromatography equipment. In addition, the effects of the switching time, the inlet methane concentration, the flow rate, and heat extraction were studied. The experimental results show that the reverse flow reactor system can run under a wide range of operating conditions with autothermal operation and high methane conversion. In addition, this system can even work with methane concentrations as low as 0.30% in the autothermal operation mode without NO x emission. Unlike previous studies, this study shows that the flow rate has little effect on the methane conversion rate in the cyclic steady state over a wide range of operating conditions. In addition, methane conversion and reaction zone change as the inlet methane concentration varies during the reaction process in the cyclic steady state. The combined optimization of operating parameters can effectively improve the stability of the reverse flow reactor system and methane conversion efficiency.