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Objectives: The study aimed to investigate whether G2/M arrest caused by O2-(2,4-dinitrophenyl) diazeniumdiolate derivative (JS-K) was related to PTEN-mediated inhibition of PI3K/Akt pathway in hepatocellular carcinoma cells. Methods: The cell apoptosis was detected by DAPI staining and Annexin V-FITC/PI dual staining. The cell cycle was analysed by PI staining. The expressions of cell cycle-related proteins, PTEN and PI3K/AKT pathway were measured by Western blot. The rat model of primary hepatic carcinoma was established with diethylnitrosamine to verify the antitumour effects of JS-K. Key findings: The morphological features of apoptosis were obviously reversed when the cells were pre-treated with bpv(pic), followed by treatment with JS-K. JS-K mediated G2/M arrest and down-regulated expressions of cyclin B1. Meanwhile, it up-regulated the expression of p-Cdk1, p-Chk2 and p-CDC25C while down-regulated that of Cdk1 and CDC25C. Furthermore, JS-K also enhanced the expressions of p21 and p27, PTEN and p53 while decreased the expressions of p-PTEN, PI3K and p-AKT. However, bpv(pic) and Carboxy-PTIO could reverse JS-K-induced G2/M cell arrest and PTEN-mediated inhibition of the PI3K/AKT pathway. The same results were also testified in the rat model of primary hepatic carcinoma. Conclusions: JS-K caused G2/M arrest through PTEN-mediated inhibition of the PI3K/AKT pathway involving Chk2/CDC25C/Cdk1 checkpoint. [ABSTRACT FROM AUTHOR]

Polyethylene oxide (PEO)‐based solid‐state batteries hold great promise as the next‐generation batteries with high energy density and high safety. However, PEO‐based electrolytes encounter certain limitations, including inferior ionic conductivity, low Li+ transference number, and poor mechanical strength. Herein, we aim to simultaneously address these issues by utilizing one‐dimensional zwitterionic cellulose nanofiber (ZCNF) as fillers for PEO‐based electrolytes using a simple aqueous solution casting method. Multiple characterizations and theoretical calculations demonstrate that the unique zwitterionic structure imparts ZCNF with various functions, such as disrupting PEO crystallization, dissociating lithium salts, anchoring anions through cationic groups, accelerating Li+ migration by anionic groups, as well as its inherent reinforcement effect. As a result, the prepared PL‐ZCNF electrolyte exhibits remarkable ionic conductivity (5.37×10−4 S cm−1) and Li+ transference number (0.62) at 60 °C without sacrificing mechanical strength (9.2 MPa), together with high critical current density of 1.1 mA cm−2. Attributed to these merits of PL‐ZCNF, the LiFePO4|PL‐ZCNF|Li solid‐state full‐cell delivers exceptional rate capability and cycling performance (900 cycles at 5 C). Notably, the assembled pouch‐cell can maintain steady operation over 1000 cycles with an impressive 93.7 % capacity retention at 0.5 C and 60 °C, highlighting the great potential of PL‐ZCNF for practical applications. [ABSTRACT FROM AUTHOR]

Bypass dual throat nozzle (BDTN) is a new kind of fluidic thrust vectoring nozzle that can provide thrust vectoring by controlling self-adaptive flow. In this paper, BDTN-tab is proposed to improve the mixing ability of the nozzle. It is defined as a new kind of BDTN with an outlet modified by a pair of tabs. Under the premise of ensuring the nozzle outlet projected area remains unchanged, the pair of tabs coplanar with the convergent section of the cavity is designed to be. This design takes aerodynamic performance, thrust vectoring performance and mixing ability into account. Conclusions can be drawn through theoretical analysis, design, numerical simulation and wind tunnel experiments: The BDTN-tab can produce a thrust vectoring angle by opening the bypass valve, which can reach an extreme angle of 32°. As the tab angle increases, the thrust coefficient and thrust vectoring angle of the nozzle decrease. However, the vortex intensity at the nozzle outlet increases and can enhance the mixing between primary flow and external flow. [ABSTRACT FROM AUTHOR]

Turbulent flows through a channel roughened with circular-arc ribs of different pitch-to-height ratios (P / H = 3. 0 , 5.0 and 7.5) at a fixed Reynolds number are studied using direct numerical simulations (DNS). It is interesting to observe that in contrast to the classical channel flow over transverse square bars, the flow separation point in a channel roughened with circular-arc ribs is sensitive to the testing conditions and varies along the rib arc. The influences of the pitch-to-height ratio on the flow separation, statistical moments of the velocity field, and the anisotropy of turbulence stresses are investigated. The dynamics of coherent structures are studied by examining the skewness of the flow field, characteristics of the joint probability density functions (JPDF) of velocity fluctuations, quadrant analysis of Reynolds stresses, instantaneous velocity field, swirling strength, and temporal–spatial two-point auto-correlations. It is found that the flow anisotropy becomes suppressed as the value of P / H increases due to significant enhancement of the spanwise Reynolds normal stress 〈 w ′ w ′ 〉. It is also interesting to observe that the lifespan of turbulence structures becomes increasingly shortened at the midspan between two adjacent ribs as the pitch-to-height ratio increases. • Direct numerical simulation of turbulent flow in a channel with one wall roughened with circular-arc ribs. • Pitch-to-height ratio effects on the flow field and statistics. • Turbulence structures developing over circular-arc ribs. [ABSTRACT FROM AUTHOR]

A review of research progress in the design of the exhaust system for the scramjet and turbine based combined cycle (TBCC) engine is presented. Firstly, the technical challenges encountered in designing the exhaust system for a hypersonic propulsion system are highlighted and discussed, and the performance parameter definition as well as the theoretical thrust prediction for the exhaust system is introduced. The review of scramjet nozzle focuses on three aspects: 1) the design method of the single expansion ramp nozzle (SERN) for the integration of the airframe with the propulsion system, in which the design method developments of the two-dimensional (2D) SERN, SERN with lateral expansion and three-dimensional (3D) SERN with shape transition are all summarized; 2) the unique flow phenomena of the scramjet nozzle, including the nonuniform inflow and chemical nonequilibrium flow in SERN; 3) the coupling and interaction of the internal flow with the external freestream. Besides, the design and flow researches of the TBCC exhaust system is also reviewed for three parts: 1) variable geometry design for wide flight range, in which both a 2D and 3D exhaust system are described; 2) the overexpanded flow separation mechanism and its control at low flight Mach number; 3) mode transition from low-speed flowpath (LSF) to high-speed flowpath (HSF) for over-under exhaust system. Through the above summary and analysis, the current status, bottlenecks, and development trend of the exhaust system for an airbreathing hypersonic propulsion system can be further clarified. [ABSTRACT FROM AUTHOR]

Bypass dual throat nozzle (BDTN) is a new kind of fluidic thrust vectoring nozzle. Based on the excellent performance of BDTN, a short takeoff and landing (STOL) exhaust system as a substitute for the complex tilt rotor is investigated. The STOL exhaust system consists of a downward-bending transition part and a BDTN part. As the thrust vectoring angle reaches more than 35° in a separate BDTN, the transition part enables the actual thrust vectoring angle to reach a maximum of over 70° in STOL mode. In cruise mode, thrust vectoring effect of BDTN compensates the inherent deflection angle of the transition part, the thrust vectoring angle reaches nearly 0°. The transition part is designed with three area-laws and two centerline-laws. Results indicate that centerline-law II leads to less total pressure distortion than centreline-law I. Area-law B is the best area-law since it leads to the moderate change rate of cross-section, it makes the total pressure distribution at the outlet of the transition part more uniform. Then, the integrated STOL exhaust system is investigated, the performances are presented. The thrust direction can be changed by controlling two valves in BDTN, the redundant tilting mechanical structure of traditional tilt rotors is replaced by this way, the structural weight is reduced, and flight safety improves. Finally, the best configuration is selected according to the results of the numerical investigation, and the thrust coefficient is more than 0.920 in STOL and cruise mode. The thrust vectoring angle is -73.37° in STOL mode, and it's -1.81° in cruise mode. The design satisfies the basic requirements for STOL and cruising flight. Hence, the STOL exhaust system is worthy of further study. [ABSTRACT FROM AUTHOR]

This study numerically investigates the nozzle performance of a rotating detonation engine with film cooling. The premixed stoichiometric hydrogen/air mixture serves as the reactant, and the pure air is pumped into the film cooling holes. The diverging section of the nozzle is designed based on the characteristic method and the maximum thrust theory. The spike truncation ratio is optimized to ΔL spike = 40% L cowl , reducing the weight and maintaining a high axial thrust coefficient of 0.9456. In contrast with the steady condition, the flow loss of the practically transient condition mainly comes from three parts. The first is the pressure loss of the continuously sweeping shock waves, the second is the viscous effect of the flow passage, and the third is the energy dissipation of the recirculation zone in the base region. When the film cooling strategies are introduced on the inner and outer walls, the hole type a/b < 1.0/1.0 is preferred thanks to a more considerable coolant coverage induced by more violent interactions between the radial jet and the mainstream. The cooling effects and the aerodynamic performance can be further balanced within a moderate injection velocity. The final optimized nozzle configuration with ΔL spike = 40% L cowl , a/b = 1.0/2.0, and V sec = 100 m/s corresponds to an axial thrust coefficient of 0.9552, a discharge coefficient of 0.9344, a pressure gain of -16.48%, and a root mean square deviation of the flow deflection angle of 14.42°. [ABSTRACT FROM AUTHOR]