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The development of nanoenergetic materials with adjustable reaction performance is the key to achieving controllable ignition and propulsion. It has become one of the research hotspots of scientists in the field of energetic materials. Due to its excellent combustion performance and good film-forming properties, the Al/PVDF energetic system with controllable reactivity has a wide application potential for ignition and propulsion. In this work, an Al@PTA/PVDF nanoenergetic film with tunable performance was successfully prepared by in situ coating a polytannic acid (PTA) interface on the surface of Al nanoparticles (nAl) and a composite assembly with polyvinylidene fluoride (PVDF). The differential scanning calorimetry results show that the main exothermic peak of the Al@PTA/PVDF film is 7.0 °C higher than that of the pure Al/PVDF nanoenergetic film when the coating thickness of the PTA interface is adjusted, and the PTA interlayer can also change the reaction mode of nAl and PVDF to a multiband exothermic. In addition, with the thickening of the PTA interface, the activation energy of the Al@PTA/PVDF film increases from 270.2 to 316.1 kJ/mol, and its average burning rate gradually decreases to 152.68 mm/s. These results indicate that the PTA interface can better control the combustion reaction of Al/PVDF, which will promote its application in the field of controllable combustion and controllable propulsion. It is concluded that the degree of contact and the diffusion length of mass transfer between the reaction components can be changed by introducing an intermediate nanolayer between the fuel and the oxidant, which allows the combustion performance of various composite energetic materials to be adjusted. [ABSTRACT FROM AUTHOR]

Background: Previously, we have demonstrated that the batch variations of human platelet lysate (conventional MSC expansion medium) induce MSC heterogeneity and therapeutic inconsistency. On the other hand, the MSCs expanded with chemical defined medium have improved therapeutic consistency. Methods: In the current study, we studied the MSC subpopulation composition and variation in different types and batches of MSC expansion medium with scRNA-seq analysis. Results: MSCs expanded with different batches of media have higher levels of heterogeneity from the perspective of cell subpopulation composition at transcriptome levels and therapeutic inconsistency. The CD317+ subpopulation has enhanced immune suppression activities. And the percentage of CD317+ MSCs within MSCs is tightly correlated with its immune suppression activities, and also contributes to the heterogeneity and therapeutic inconsistency of MSCs. the CD317+ MSCs have increased expression levels of PTX3, which might stabilize the TSG6 protein and improve the therapeutic effects Conclusions: Thus, purifying CD317+ MSCs is one efficient strategy to reduce MSC heterogeneity and increase the therapeutic consistency of MSCs. [ABSTRACT FROM AUTHOR]

Traditional lead-based primary explosives present challenges in application to micro-energetics-on-a-chip. It is highly desired but still remains challenging to design a primary explosive for the development of powerful yet safe energetic films. Copper-based azides (Cu(N3)2 or CuN3, CA) are expected to be ideal alternatives owing to their properties such as excellent device compatibility, excellent detonation performance, and low environmental pollution. However, the significantly high electrostatic sensitivity of CA limits its use in micro-electro-mechanical systems (MEMS). This study presents an in situ electrochemical approach to preparing and modifying a CA film with excellent electrostatic safety using a Cu chip. Herein, a CA film is prepared by employing Cu nanorod arrays as precursors. Next, polypyrrole (PPy) is directly coated on the surface of the CA materials to produce a CA@PPy composite energetic film using the electrochemical process. The results show that CuN3 is first generated and gradually oxidized to Cu(N3)2, essentially forming enclosed nest-like structures during electrochemical azidation. The microstructure and composition of the product can be regulated by varying the current density and reaction time, which leads to controllable heat output of the CA from 521 to 1948 J g−1. Notably, the composite energetic film exhibits excellent electrostatic sensitivity (2.69 mJ) owing to the excellent conductivity of PPy. Thus, this study offers novel ideas for the further advances of composite energetic materials and applications in MEMS explosive systems. [ABSTRACT FROM AUTHOR]

Background: Although both preclinical and clinical studies have shown the great application potential of MSCs (mesenchymal stem/stromal cells) in treating many kinds of diseases, therapeutic inconsistency resulting from cell heterogeneity is the major stumbling block to their clinical applications. Cell population diversity and batch variation in the cell expansion medium are two major inducers of MSC heterogeneity. Methods: Cell population diversity was investigated through single-cell RNA sequencing analysis of human MSCs derived from the umbilical cord and expanded with fully chemically defined medium in the current study. Then, the MSC subpopulation with enhanced anti-inflammatory effects was studied in vitro and in vivo. Results: Our data showed that MSCs contain different populations with different functions, including subpopulations with enhanced functions of exosome secretion, extracellular matrix modification and responses to stimuli (regeneration and immune response). Among them, CD317+ MSCs have improved differentiation capabilities and enhanced immune suppression activities. Underlying mechanism studies showed that higher levels of TSG6 confer enhanced anti-inflammatory functions of CD317+ MSCs. Conclusions: Thus, CD317+ MSCs might be a promising candidate for treating immunological disorder-related diseases. [ABSTRACT FROM AUTHOR]

At present, the double-enzyme catalyzed method using maltooligosyltrehalose synthase (MTSase) and maltooligosyltrehalose trehalohydrolase (MTHase) is the mainstream technology for industrial trehalose production. However, MTSase and MTHase are prepared mainly using the heterologous expression in the engineered Escherichia coli strains so far. In this study, we first proved that the addition of 3 U/g neutral pullulanase PulA could enhance the trehalose conversion rate by 2.46 times in the double-enzyme catalyzed system. Then, a CBM68 domain was used to successfully assist the secretory expression of MTSase and MTHase from Arthrobacter ramosus S34 in Bacillus subtilis SCK6. At the basis, an engineered strain B. subtilis PSH02 (amyE::pulA/pHT43-C68-ARS/pMC68-ARH), which co-expressed MTSase, MTHase, and PulA, was constructed. After the 24 h fermentation of B. subtilis PSH02, the optimum ratio of the extracellular multi-enzymes was obtained to make the highest trehalose conversion rate of 80% from 100 g/L maltodextrin. The high passage stability and multi-enzyme preservation stability made B. subtilis PSH02 an excellent industrial production strain. Moreover, trehalose production using these extracellular enzymes produced via the one-step fermentation of B. subtilis PSH02 would greatly simplify the procedure for multi-enzyme preparation and be expected to reduce production costs. [ABSTRACT FROM AUTHOR]

A carbohydrate binding module 68 (CBM68) of pullulanase from Anoxybacillus sp. LM18-11 was used to enhance the secretory expression of a thermostable α-amylase (BLA702) in Bacillus subtilis, through an atypical secretion pathway. The extracellular activity of BLA702 guided by CBM68 was 1248 U/mL, which was 12.6 and 7.2 times higher than that of BLA702 guided by its original signal peptide and the endogenous signal peptide LipA, respectively. A single gene knockout strain library containing 51 genes encoding macromolecular transporters was constructed to detect the effect of each transporter on the secretory expression of CBM68-BLA702. The gene knockout strain 0127 increased the extracellular amylase activity by 2.5 times. On this basis, an engineered strain B. subtilis 0127 (AmyE::BLA702-NprB::CBM68-BLA702-PrsA) was constructed by integrating BLA702 and CBM68-BLA702 at the AmyE and NprB sites in the genome of B. subtilis 0127, respectively. The molecular chaperone PrsA was overexpressed, to reduce the inclusion body formation of the recombinant enzymes. The highest extracellular amylase activity produced by B. subtilis 0127 (AmyE::BLA702-NprB::CBM68-BLA702-PrsA) was 3745.7 U/mL, which was a little lower than that (3825.4 U/mL) of B. subtilis 0127 (pMAC68-BLA702), but showing a better stability of passage. This newly constructed strain has potential for the industrial production of BLA702. [ABSTRACT FROM AUTHOR]

Research on the distribution of mantle CO2 should involve comprehensive analysis from CO2 source to accumulation. The crust‐mantle pathway system is the key controlling factor of the distribution of mantle CO2, but has received little attention. The pathway system and controlling factors of CO2 distribution in the Bohai Sea are analyzed using data on fault styles and information on the mantle and lithosphere. The relation between volcanic rocks and the distribution of mantle CO2 is reassessed using age data for CO2 accumulations. The distribution of mantle CO2 is controlled by uplift of the asthenosphere and upper mantle, magma conduits in the mantle and fault systems in the crust. Uplifted regions of the asthenosphere are accumulation areas for CO2. The area with uplift of the Moho exhibits accumulation of mantle CO2 at depth. CO2 was mainly derived from vertical migration through the upper mantle and lower crust. The fault style in the upper crust controls the distance of horizontal migration and the locations of CO2 concentrations. The distribution of mantle CO2 and volcanic rocks are not the same, but both probably followed the same pathways sometimes. Mantle CO2 in the Bohai Sea is concentrated in the Bozhong sag and the surrounding area, particularly in a trap that formed before 5.1 Ma and is connected to crustal faults (the Bozhang faults) and lithospheric faults (the Tanlu faults). [ABSTRACT FROM AUTHOR]

Objectives: Myocardial infarction (MI) is the most predominant type of cardiovascular diseases with high mortality and morbidity. Stem cell therapy, especially cardiac progenitor cell therapy, has been proposed as a promising approach for cardiac regeneration and MI treatment. Previously, we have successfully generated cardiac progenitor‐like cells, induced cardiosphere (iCS), via somatic reprogramming. However, the genome integration characteristic of virus‐based reprogramming approach hampered their therapeutic applications due to the risk of tumour formation. In the current study, we aim to establish a safer iCS generation strategy with transgene‐free approaches. Materials and Methods: Four transgene‐free approaches for somatic reprogramming, including episome, minicircle, self‐replicative RNA, and sendai virus, were compared, from the perspective of cardiac progenitor marker expression, iCS formation, and cardiac differentiation. The therapeutic effects were assessed in the mouse model of MI, from the perspective of survival rate, cardiac function, and structural alterations. Results: The self‐replicative RNA approach produced more iCS, which had cardiomyocyte differentiation ability and therapeutic effects on the mouse model of MI with comparable levels with endogenous cardiospheres and iCS generated with retrovirus. In addition, the CXCR4 (C‐X‐C chemokine receptor 4) positive subpopulation of iCS derived cells (iCSDC) delivered by intravenous injection was found to have similar therapeutic effects with intramyocardial injection on the mouse model of MI, representing a safer delivery approach. Conclusion: Thus, the optimized strategy for iCS generation is safer and has more therapeutic potentials. [ABSTRACT FROM AUTHOR]