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In view of the powder feeding system, a multi-physical coupling model of the gas-powder-piston was established based on the Euler-Euler two-fluid model. The numerical simulation method was applied to explore the effects of dense gas-solid flow characteristics under different operating pressures. The results show that gas-solid pulsations at different operating pressures are mainly concentrated in the upper part of the powder tank. An elevated operating pressure efficiently decreases the powder layer area (εp = 0.1) fluctuation. As the operating pressure increases from 0.5 MPa to 3.0 MPa, the rising time and fluctuation rate of pressure are reduced by 71.4% and 62.3%, respectively, and the pressure in the tank has a long stabilization period. Meanwhile, the variation of the instantaneous powder flow rate is more stable and its average value is closer to the theoretical. A high-pressure environment is more conducive to the stable transportation of powder.

Obesity has now surpassed malnutrition and infectious diseases as the most significant contributor to health problems worldwide. In particular, obesity is associated with several metabolic disorders, including hyperlipidemia, hepatic steatosis, and subfertility. Genipin (GNP), the aglycone of geniposide, is isolated from the extract of the traditional Chinese medicine Gardenia jasminoides Ellis and has been used in traditional oriental medicine against several inflammation-driven diseases. However, the effect and molecular mechanism of GNP on obesity-associated dyslipidemia and sperm dysfunction still need to be explored. In this study, we detect the effects of GNP on hyperlipidemia, hepatic lipid accumulation and sperm function using a high-fat diet (HFD)-induced obese mouse model. We find that obese mice treated with GNP show an improvement in body weight, serum triglyceride levels, serum hormone levels, serum inflammatory cytokines, hepatic steatosis and sperm function. At the molecular level, HFD/GNP diversely regulates the expression of miR-132 in a tissue-specific manner. miR-132 further targets and regulates the expression of SREBP-1c in liver cells, as well as the expressions of SREBP-1c and StAR in Leydig cells in the testis, thus modifying lipogenesis and steroidogenesis, respectively. Collectively, our data demonstrate that GNP shows a broad effect on the improvement of HFD-induced metabolic disorder and sperm dysfunction in male mice by tissue-specific regulation of miR-132. Our findings reveal the function GNP in ameliorating hepatic lipid metabolism and sperm function and suggest that this compound is a versatile drug to treat metabolic disorders.

The fluidization and transportation characteristics of powder fuel is a key to the design of fuel supply system of powder engine. In order to deeply study the fluidization characteristics of powder fuel, a numerical simulation method based on the two fluid model for dense gas-solid is built, which considers the action of moving wall through user defined function(UDF), and the influence of gas flow rate on the fluidization and characteristics of powder fuel are analyzed numerically. The results show that in the start-up stage, the powder mass flow rate entrained by fluidized gas under different cases is greater than theoretical flow rate, the pressure in powder storage tank and the force on moving wall are greater than that in steady stage, and the particle output and powder storage tank pressure increase with the increase of fluidized gas flow rate.In steady stage, the mass flow rate of powder pushed forward by the moving wall and the powder mass flow rate entrained by fluidized gas reach a dynamic balance. A relatively stable gas-solid interface can be formed under different cases, and the average powder flow rate is less than the theoretical flow rate. The average powder flow rate increases with the increase of fluidized gas flow rate, and the height of powder bed decreases with the increase of fluidized gas flow rate.

Resourceful beyond-graphene two-dimensional (2D) carbon crystals have been proposed/synthesized; however, the fundamental knowledge of their melting thermodynamics remains lacking. Here, the structural and thermodynamic properties of nine contemporary 2D carbon crystals upon heating are investigated using first-principle-based ReaxFF molecular dynamics simulations. Those 2D carbon crystals show distinct evolution of energetic and Lindemann index that distinguish their thermal stabilities. There are two or three critical temperatures at which structural transformation occurs for non-hexagon-contained 2D carbon allotropes. Analysis of polygons reveals that non-hexagon-contained 2D carbon crystals show thermally induced hex-graphene transitions via mechanisms such as bond rotations, dissociation, and reformation of bonds. The study provides new insights into the thermodynamics and pyrolysis chemistry of 2D carbon materials, as well as structural transitions, which is of great importance in the synthesis and application of 2D materials in high-temperature processing and environment.

Clathrate hydrates find diverse significant applications including but not limited to future energy resources, gas storage and transport, gas separation, water desalination, and refrigeration. Studies on the nucleation, growth, dissociation, and micro/nanoscale properties of clathrate hydrates that are of utmost importance for those applications are challenging by experiments but can be accessible by molecular simulations. By this method, however, identification of cage structures to extract useful insights is highly required. Herein, we introduce a hierarchical topology ring (HTR) algorithm to recognize cage structures with high efficiency and high accuracy. The HTR algorithm can identify all types of complete cages and is particularly optimized for hydrate identification in large-scale systems composed of millions of water molecules. Moreover, topological isomers of cages and n × guest@cage can be uniquely identified. Besides, we validate the use of HTR for the identification of cages of clathrate hydrates upon mechanical loads to failure.

Acetylcholine regulates various cognitive functions through broad cholinergic innervation. However, specific cholinergic subpopulations, circuits and molecular mechanisms underlying recognition memory remain largely unknown. Here we show that Ngfr+ cholinergic neurons in the substantia innominate (SI)/nucleus basalis of Meynert (nBM)-medial prefrontal cortex (mPFC) circuit selectively underlies recency judgements. Loss of nerve growth factor receptor (Ngfr−/− mice) reduced the excitability of cholinergic neurons in the SI/nBM-mPFC circuit but not in the medial septum (MS)-hippocampus pathway, and impaired temporal order memory but not novel object and object location recognition. Expression of Ngfr in Ngfr−/− SI/nBM restored defected temporal order memory. Fiber photometry revealed that acetylcholine release in mPFC not only predicted object encounters but also mediated recency judgments of objects, and such acetylcholine release was absent in Ngfr−/− mPFC. Chemogenetic and optogenetic inhibition of SI/nBM projection to mPFC in ChAT-Cre mice diminished mPFC acetylcholine release and deteriorated temporal order recognition. Impaired cholinergic activity led to a depolarizing shift of GABAergic inputs to mPFC pyramidal neurons, due to disturbed KCC2-mediated chloride gradients. Finally, potentiation of acetylcholine signaling upregulated KCC2 levels, restored GABAergic driving force and rescued temporal order recognition deficits in Ngfr−/− mice. Thus, NGFR-dependent SI/nBM-mPFC cholinergic circuit underlies temporal order recognition memory. Functional roles of the diverse cholinergic subpopulations such as those in the substantia innominate (SI) and the nucleus basalis of Meynert (nBM) are not fully understood. Here the authors show that Ngfr+ cholinergic neurons in the SI/nBM-mPFC circuit selectively regulates recency judgement in recognition memory. [ABSTRACT FROM AUTHOR]