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To obtain atomic-level insights into the decomposition of 1,3,5-trinitro-2,4,6-trinitroaminobenzene (TNTNB) under different stimulations, this study applied reactive molecular dynamics simulations to illustrate the effects of thermal and shock stimuli on the TNTNB crystal.

The objective of this study was to investigate whether supplementation with N-carbamoylglutamate (NCG) to cows during late gestation alters uteroplacental tissue nutrient transporters, calf metabolism and newborn weight. Thirty multiparous Chinese Holstein cows were used in a randomized complete block design experiment. During the last 28 d of pregnancy, cows were fed a diet without (CON) or with NCG (20 g/d per cow). The body weight of calves was weighed immediately after birth. Placentome samples were collected at parturition and used to assess mRNA expression of genes involved in transport of arginine, glucose, fatty acid and angiogenesis factors, as well as the mammalian target of rapamycin (mTOR) pathway. Blood samples of calves before colostrum consumption were also collected for the detection of plasma parameters, amino acids (AA) and metabolomics analysis. The newborn weight (P = 0.02) and plasma Arg concentration of NCG-calves was significantly higher (P = 0.05) than that of CON-calves, and the plasma concentrations of urea nitrogen tended to be lower (P = 0.10) in the NCG group. The mRNA abundance of genes involved in glucose transport (solute carrier family 2 member 3 [SLC2A3], P < 0.01), angiogenesis (nitric oxide synthase 3 [NOS3], P = 0.02), and mTOR pathway (serine/threonine-protein kinase 1 [AKT1], P = 0.10; eukaryotic translation initiation factor 4B pseudogene 1 [EIF4BP1], P = 0.08; EIF4EBP2, P = 0.04; and E74-like factor 2 [ELF2], P = 0.03) was upregulated in the placentome of NCG-supplemented cows. In addition, 17 metabolites were significantly different in the placentome of NCG-supplemented cows compared to non-supplemented cows, and these metabolites are mainly involved in arginine and proline metabolism, alanine, aspartate and glutamate metabolism, and citrate cycle. In summary, the increased body weight of newborn calves from the NCG supplemented dairy cows may be attributed to the increased angiogenesis and uteroplacental nutrient transport and to the activated mTOR signal pathway, which may result in the increased nutrient supply to the fetus, and improved AA metabolism and urea cycle of the fetus.

Adding AlH3 nanoparticles (AHNPs) into energetic materials has become a widely used strategy to enhance the efficiency of heat release. However, the underlying mechanisms in the reaction between AHNPs and energetic materials are poorly understood. The evolution of AHNPs in 2,2′,4,4′,6,6′-hexanitrodiphenyl ethylene (HNS) was simulated by reactive dynamic based on ReaxFF force field. As a whole, adding AHNPs unexceptionally increases heat release, and the particle size, passivation shell, and contents of AHNPs influence the morphological evolution and hydrogen release performance. AHNPs with smaller size can rapidly release hydrogen under the drastic micro-explosion. In addition, the aggregation mechanism of AHNPs is revealed at the earlier and later stages of the reaction. Al-O, Al-C, and Al-N bonds are generated during the reaction. A large amounts of H of AHNPs and C of HNS cause O to be desorbed from the Al-contained cluster. For the core–shell structure or/and larger size AHNPs, their oxidation process undergoes a transformation of H2–H2O in the gas cavity. Carbon clusters formed during the reaction depend on the distribution of Al. The addition of AHNPs could promote the graphitization of carbon clusters. This work is expected to deepen insight into the reaction mechanism of AHNPs-containing energetic materials with negative oxygen balance.

Metal hydride additives, aluminum hydride in particular, have extensively been applied in solid rocket motor propellants. This work employed the reactive force field molecular dynamics to elaborate the underlying mechanism for the oxidation of highly active aluminum hydride nanoparticles (AHNPs) by gaseous oxides (CO, CO2, NO, and NO2). The results showed that AHNPs first went through four stages: dehydrogenation ( 25 ps), micro-explosion (~31 ps), and oxidation (>28 ps). The dehydrogenation of AHNPs surface overlaps with the Al nucleation in the preheating stage and prevents the oxidation of Al by gaseous oxides. Only a small part of Al on the surface is oxidized to form a thin and uneven oxide film (0.18–0.54 nm). In the core, the formed H2 is hindered by the shell and gradually gathers into H2 bubbles. H2 bubbles have great kinetic energy and become a micro-explosion promoter, eventually causing nanoparticles to burst at high temperatures. The micro-explosion accelerates the dissociation of gaseous oxides. This study provides an in-depth understanding of the mechanism of dehydrogenation and oxidation of metal hydride nanoparticles.

Molecular dynamics simulations on the reactions of nano-aluminum, water with different proportions of hydrogen peroxide were performed by ReaxFF. The reaction rate of the system increases by 27% as the molar ratio of H2O2 increases from 0 to 30%. The reaction paths in each period are elucidated by the change of the numbers of reactants and products. The reaction absorbs heat and releases isolated H atoms in the initial stage through pathways Al + 3H2O → Al(OH)3 + 3H and 3Al + 2H2O → 2AlO + AlH3 + H. Subsequently, H2O2 decomposes and releases O2 through 2H2O2 → 2H2O + O2 as the temperature rises to 350 K. And these O2 are rapidly involved in the formation of Al2O3, corresponding to the process 4AlO + O2 → 2Al2O3 and 2Al(OH)3 + 2AlH3 + 3O2 → 2Al2O3 + 6H2O. In the final stage, H2 molecules generated in accordance with the pathways of Al(OH)3 + AlH3 → Al2O3 + 3H2 and 2AlH3 + 3H2O → Al2O3 + 6H2. Particularly, the production of H2 decreases by 28.2%, 49.8% and 68.6%, as the molar ratio of H2O2 increases from 0 to 10%, 20% and 30%, respectively. Meanwhile, the reaction of Al/H2O/H2O2 releases much more energy (271.40–440.53 kJ/mol) than that of Al/H2O (180.67 kJ/mol). Moreover, the ignition temperature decreases with the increase of H2O2 concentration, but is proportional to the heating rate of ignition. When the molar ratio of H2O2 increases from 0 to 30%, the adiabatic flame temperature of the mixture increases linearly from 2400 K to 3000 K according to the adiabatic simulation.

Metal nanoparticles are easily deactivated by migration-aggregation in combustion. Encapsulated nanoparticles are one of the tools for coping with the stability challenges of metal nanoparticles. The self-assembly details of aluminum nanoparticles (ANPs) encapsulated into carbon nanotubes (CNTs) were demonstrated by molecular dynamics simulations. The simulation results show that ANPs can completely self-roll into CNTs to form a stable core-shell structure by inertial force and van der Waals force. Inside the tubes, ANPs move toward the cap at a velocity of 2.27 Å ps-1. However, it increases to 3.17 Å ps-1 when near the cap of CNTs. The initiation of the ANPs' oxidation and degradation can be effectively checked by coating CNTs. The diffusion of the Al atoms in the encapsulated ANPs occurred earlier than their oxidation in combustion, verified by using ReaxFF molecular dynamics simulations. The morphological evolutions of the nanostructures in the initial combustion of the encapsulated ANPs are predicted. The interplay between the encapsulated ANPs' responses and external stimuli is classified into core-shell separation, shell damage, and core-shell burst, which provides insights into the oxidation mechanism of encapsulated nanoparticles.

The modified attachment energy model was applied to predict the crystal morphology of hexanitrohexaazaisowurtzitane/1,3-dinitrobenzene (HNIW/DNB) cocrystal in ethanol. A double-layer interface structure was established based on experiments. Molecular dynamics simulation was employed to investigate the interaction of flat faces and ethanol solvents. We used periodic bond chains and roughness calculations to analyze the characteristics of the HNIW/DNB cocrystal. The crystal morphology of the HNIW/DNB cocrystal is mainly composed of the (001), (010), (102), and (111) faces in vacuum. The (001) face occupies the largest area (49.54%). In ethanol, the area of the (001) face increases to 68.58%. Ethanol molecules are adsorbed on the polar face through hydrogen bonding. In the slowest growth direction, two HNIW layers and one DNB layer alternately appear. The higher molecular recognition of the (001) face of HNIW/DNB resulted in this face becoming the most important growth face. Meanwhile, we also predicted the crystal morphologies of ε-HNIW and DNB in ethanol. The prediction morphologies are in excellent agreement with the experimental shapes. These simulation results can provide guidance for the recrystallization of HNIW/DNB.

Hexanitrostilbene plays an important role in aerospace and space technology because of its excellent chemical stability. However, carbon deposition during the explosion seriously affects its detonation performance. A newly parameterized reactive force field was used to simulate the decomposition behavior of nanometer aluminized hexanitrostilbene. Aluminum nanoparticles and the corresponding surface oxidized ones were mixtured with the hexanitrostilbene to build nanometer aluminized composites. The simulation results show that aluminum nanoparticles lead to an earlier decomposition of hexanitrostilbene in a new way. Aluminum nanoparticles follow diffusion oxidation theory in the heating. At high temperatures, Aluminum nanoparticle quickly splits and exposes active aluminum to participate in the reaction. The presence of oxide layer in surface oxidized aluminum nanoparticle is less attractive to oxygen, carbon and nitrogen atoms, and surface oxidized aluminum nanoparticle is difficult to split into small particles during ignition and detonation. Aluminum nanoparticles prevent the formation of larger carbon clusters and cause hydrogen and oxygen atoms escape from carbon clusters. This is the main reason for the increasing detonation pressure and energy outputs of nanometer aluminized Hexanitrostilbene. Adiabatic simulation shows that nanometer aluminized hexanitrostilbene decomposes faster and releases more energy than pure hexanitrostilbene. This work provides insights for the application of aluminized hexanitrostilbene composites in aerospace.

We report a first attempt to investigate the reaction mechanisms of hydroborate iron compound (HIC), a promising candidate for combustion catalyst, in AP/HTPB/Al composite solid propellants using ammonium perchlorate (AP) as the oxidizer and aluminum as the metal fuel. The effects of HIC on the combustion properties of propellants were experimentally examined to determine burning rates, combustion flame structures and flame temperature distribution. The combustion residues were collected and examined; the mechanical sensitivity of propellant samples were tested. It was found that the addition of HIC particles can increase the burning rates with only minor changes of the pressure exponent. When 5.0 wt% of Al is replaced by HIC, the pressure exponent increases from 0.31 to 0.35 over the pressure range 1–12 MPa while the burning rate increases from 33 mm s−1 to 40 mm s−1 at 7 MPa. The combustion flame images of burning propellants surface loaded with HIC at various pressures present multi-flame structures, and the flame brightness increases with increasing the pressure. Many sparks are observed near the burning surface during the propellant combustion, due to burning aluminum particles in gas phase. With 5.0 wt% HIC included, the propellant produces very different condensed combustion products (CCPs) with a variety of morphologies, and the most typical ones are “porous” shape, large alveolate and loose structures. The relative combustion residue mass decreases with increasing pressure (1–5 MPa) and HIC mass fraction in the formulation (0–5%); While HIC powder is insensitive to friction and impact stimuli (0% at height is higher than 125 cm), the tested propellant formulations containing different mass fraction of HIC particles result sensitive to impact and friction a bit more than the reference formulation without HIC particles.

The ReaxFF-lg is used to simulate the thermal decomposition of the pure nitroglycerin (NG) and nitroglycerin/nano-Al (NG/Al) systems. The simulation results show that the decomposition pathway of NG is the rupture of C–H and O–N bonds. However, the rupture of C–O and N–O bonds of NG is the main decomposition pathway in the NG/Al system. The strong attraction Al to oxygen atoms accelerates NG decomposition. The reaction of the NG/Al system begins on the surface between NG and Al. The surface of aluminum particles is the first to be oxidized. As the temperature increases, O atoms attached to the surface of Al particles penetrate into the aluminum particles. The interior of aluminum particles gradually becomes disordered and fluffy from orderly arrangement. The interaction between O and Al constitutes the early combustion reaction of the NG/Al system, which reduces the production of O-containing intermediates. The attraction of Al to C is greater than that to N at high temperatures, which increases the yield of C-Al cluster and decrease the yield of CO₂ at high temperature. The decomposition of NG/Al is an exothermic reaction without energy barrier. The decomposition of NG needs to overcome an energy barrier of 44.27 kcal/mol. Adiabatic simulation shows that the decomposition rate, heat release rate, and energy release rate of the NG/Al system are significantly higher than those of the NG system. This work presents a comprehensive insight into the interaction mechanism between nano-Al and NG.

The influence of hydrostatic pressure on the binding energy of hydrogenic impurity state in a wurtzite AlyGa1-yN/AlxGa1-xN parabolic quantum well and GaN/AlxGa1-xN square quantum well are studied using the variational method. The ground-state binding energies are presented as the functions of hydrostatic pressure, well width, composition and impurity center position. The anisotropic properties of the parameters in the system, and the changes (dependence) of electron effective mass, the dielectric constant, band gap with pressure and coordinate are considered in the numerical calculations. The results show that the hydrostatic pressure has obvious influence on the binding energy. The binding energy increase slowly with increasing the hydrostatic pressure p and the composition x, while the binding energy decrease significantly with increasing the well width and the position of impurity center. It is seen that the changing trends of the binding energy as a function of well width, pressure and the composition in the AlyGa1-yN/AlxGa1-xN parabolic quantum well are basically the same with that in the GaN/AlxGa1-xN square quantum well, but the changing trends of the binding energy as a function of impurity center position in the AlyGa1-yN/AlxGa1-xN parabolic quantum well are significantly greater than that in the GaN/AlxGa1-xN square quantum well.

Each quarter of the bovine mammary gland is an anatomically and functionally distinct gland. However, mastitis in one quarter may affect function of adjacent, uninfected glands. To investigate the mechanisms and potential mediators of these effects, we quantified early responses of the mammary gland to intramammary lipopolysaccharide (LPS) challenge, distinguishing between local and systemic effects. Ten multiparous cows over 70 d in milk were blocked into pairs by breed, cow-level somatic cell count (SCC), and milk yield. Within block, one cow was assigned to LPS treatment (T) such that both the front and the rear quarter of a randomly selected udder half received an infusion of 50 µg of LPS in 10 mL of saline (T-L); the contralateral quarters received only 10 mL of saline (T-S). Similarly, each paired control cow (C) received either 10 mL of saline (C-S) or no infusion (C-N) into udder halves. Cows were quarter milked twice daily, with foremilk samples (∼30 mL, front quarters) taken at -24, 0, 3, 6, 12, and 24 h relative to infusions. At 24 h, average milk yield in T-L and T-S quarters fell to 23 and 32% of pre-infusion levels, respectively. For T cows, systemic effects were observed by 3 h post-infusion as rectal temperature was elevated and foremilk fat concentration was reduced in both T-L and T-S. However, SCC and concentrations of l-lactate and total protein in foremilk indicated a local response to LPS: protein was transiently higher at 3 h, whereas SCC and lactate were higher at 6 h in T-L compared with T-S. Lactose concentration showed a local effect at 6 h, being lower in T-L than in T-S, and then a systemic effect at 12 h, being lower in both T-L and T-S than C quarters. Concomitant with changes in milk, systemic effects were also observed in blood. Plasma antioxidant potential and glucose concentration were lower in T cows than in C cows at 6 or 12 h, respectively, although neither variable remained different at 24 h. In summary, unilateral LPS infusion induced distinct, time-dependent effects on each milk component. Depending on the component, effects were local, systemic, or both, suggesting involvement of multiple different mediators that collectively result in systemic inhibition of milk production.

Ni(NH3)4(AFT)2 [NiC6H16N18O2, AFT = 4-amino-3-(5-tetrazolate)furazan] is synthesized and characterized by elemental analysis and Fourier-transform infrared spectroscopy for the first time. X-ray diffraction measurements are used to determine the crystal structure of compound 1. The results demonstrate that compound 1 crystallized in the orthorhombic crystal system. The nickel(II) ion is six-coordinated by N atoms from two AFT-ligands and four NH3 molecules. Its thermal properties are investigated by differential scanning calorimetry and thermogravimetry-derivative thermogravimetry methods, with the results demonstrating that the differential scanning calorimetry curve exhibits two endothermic and one exothermic processes. The endothermic processes are in the range of 130–510 °C with a peak temperature of 188 °C. The temperature from 230 to 400 °C is the exothermic process in which the peak temperature is 314.58 °C. In addition, Kissinger’s and Ozawa-Doyle’s methods are used for calculating the non-isothermal kinetics parameters. Moreover, the apparent activation energy ( E), safety, and thermal stability parameters ( TSADT, TTIT, Tb) for Ni(NH3)4(AFT)2 are calculated. In addition, the calculated thermodynamic functions ( ∆S≠, ∆H≠, and ∆G≠) for the exothermic decomposition process of Ni(NH3)4(AFT)2 are 55.07 J mol−1 K−1, 196.18 kJ mol−1, and 164.90 kJ mol−1, respectively.

Aluminum nanoparticles (ANPs), as an economical and effective metal fuel, are widely applied in energetic formulations. The objective of this research was to gain insights into the oxidation of ANPs in gaseous oxides (CO2, CO, NO2, and NO). The reactive molecular dynamics (RMD) simulations were performed to elucidate the detailed mechanisms of surface oxidation, chain-like products formation, and hollow formation in the evolution of ANPs. The O atoms in gaseous oxides are adsorbed on the ANPs' surface followed by the cleavage of O–C/N bond. The nucleation and growth of chain-like products occur in dense gaseous oxides. The four forms of chain products include tilted chain, twisted chain, branched chain, and cyclic chain were observed in CO atmosphere. A similar chain structure is also formed in NO atmosphere, but the chain length is significantly reduced. The oxide shell of ANPs is formed and expands rapidly in CO2 atmosphere, resulting in voids between oxide shell and Al core. Al atoms are transported from the core to the oxide shell through a bridge composed of Al atoms. The Al core gradually diffused outward and was eventually hollowed out. In addition, the final product has carbon deposits (C48 and C98) on the surface and core.

During lactation, an improper glucose supply often threatens mammary gland (MG) health. However, information is limited on the metabolic trajectories and molecules that regulate lactating MGs with an excessive glucose supply. Based on the network analysis of transcriptome and microRNAs, we found that the oversupply of glucose-induced severe glucose metabolic disorders in MGs of lactating goats, shifting lactose synthesis to acute fermentative glycolysis which caused increased flux of glucose metabolism into lactate. Moreover, NF-κB2 played a key role in regulating glycolysis, exhibiting a metabolic shift when MGs had an excessive supply of glucose. In primary mammary epithelial cells, fermentative glycolysis, and intracellular concentration of reactive oxygen species (ROS) were reduced by ganoderic acid A through blocking NF-κB2, while activation of NF-κB2 with phorbol myristate acetate (PMA) upregulated fermentative glycolysis and increased cellular ROS accumulation under excessive glucose. Thus, we established an NF-κB2-targeting method to reform the metabolic shift toward glycolysis caused by glucose oversupply by integrating NF-κB2 blockade and intracellular ROS scavenging.

BACKGROUND Pregnancy-induced hypoaminoacidemia, l-methionine (Met) included, disturbs embryogenesis and may also affect breast function. Supplementation with the dipeptide l-methionyl-Met (Met-Met) may improve lactation performance. OBJECTIVE We compared the effects of supplemental Met or Met-Met during pregnancy on mammogenesis and lactogenesis and investigated underlying mechanisms. METHODS In experiment 1, 9-wk-old ICR mice (n = 72, ∼30 g) were divided into 3 groups. During the first 17 days of pregnancy (DP), the Control group was fed a diet with Met (8.2 g/kg) and saline was intraperitoneally injected, the Met group was fed a Met-devoid diet and 35% of the Met (92-mmo l Met) as contained in the Control diet was intraperitoneally injected, and the Met-Met group was fed the same diet and 70-mmo l Met plus 11-mmo l Met-Met was intraperitoneally injected. All animals were fed the Control diet after DP17 and during lactation. Mammogenesis, lactogenesis, transcriptome at DP17, and milk performance during lactation were examined. In experiment 2, 9-wk-old ICR mice (n = 55, ∼30 g) at DP0 were injected through the teat with adeno-associated virus for overexpression/inhibition of phosphoinositide-3-kinase regulatory subunit 1 (Pik3r1), divided into the Control, Met, and Met-Met groups and received the same treatment as experiment 1 to examine mammogenesis and lactogenesis at DP17. RESULTS In experiment 1, compared with the Met group, the Met-Met group showed higher (P

Background The local supply of energy-yielding nutrients such as glucose seems to affect the synthesis of milk components in the mammary gland (MG). Thus, our study was conducted to investigate the effects of locally available MG glucose supply (LMGS) on amino acid (AA) sensing and utilization in the MG of lactating dairy goats. Six dosages of glucose (0, 20, 40, 60, 80, and 100 g/d) were infused into the MG through the external pudendal artery to investigate the dose-dependent changes in mammary AA uptake and utilization (Exp.1) and the changes in mRNA and protein expression of the AMPK-mTOR pathway (Expt.2). Results In Exp.1, total milk AA concentration was highest when goats were infused with 60 g/d glucose, but lower when goats were infused with 0 and 100 g/d glucose. Increasing LMGS quadratically changed the percentages of αS2-casein and α-lactalbumin in milk protein, which increased with infusions from 0 to 60 g/d glucose and then decreased with infusions between 60 and 100 g/d glucose. The LMGS changed the AA availability and intramammary gland AA utilization, as reflected by the mammary AA flux indexes. In Exp.2, the mRNA expression of LALBA in the MG increased quadratically with increasing LMGS, with the highest expression at dose of 60 g/d glucose. A high glucose dosage (100 g/d) activated the general control nonderepressible 2 kinase, an intracellular sensor of AA status, resulting in a reduced total milk AA concentration. Conclusions Our new findings suggest that the lactating MG in dairy goats may be affected by LMGS through regulation of the AA sensory pathway, AA utilization and protein synthesis, all being driven by the AMPK-mTOR pathway.

The advanced spiral growth model that considers the thermodynamics and kinetics aspects of the adsorption process is applied to predict the growth habits of the nitroguanidine crystal in water and ...

Extensive density functional theory (DFT) calculation and data analysis on molecular and crystal level features of 60 reported energetic materials (EMs) allowed us to define key descriptors that are characteristics of these compounds’ thermostability. We see these descriptors as reminiscent of “Lipinski’s rule of 5”, which revolutionized the design of new orally active pharmaceutical molecules. The proposed descriptors for thermostable EMs are of a type of molecular design, location and type of the weakest bond in the energetic molecule, as well as specific ranges of oxygen balance, crystal packing coefficient, Hirshfeld surface hydrogen bonding, and crystal lattice energy. On this basis, we designed three new thermostable EMs containing bridged, 3,5-dinitropyrazole moieties, HL3, HL7, and HL9, which were synthesized, characterized, and evaluated in small-scale field detonation experiments. The best overall performing compound HL7 exhibited an onset decomposition temperature of 341 °C and has a density of 1.865 g cm–3, and the calculated velocity of detonation and maximum detonation pressure were 8517 m s–1 and 30.6 GPa, respectively. Considering HL7’s impressive safety parameters [impact sensitivity (IS) = 22 J; friction sensitivity (FS) = 352; and electrostatic discharge sensitivity (ESD) = 1.05 J] and the results of small-scale field detonation experiments, the proposed guidelines should further promote the rational design of novel thermostable EMs, suitable for deep well drilling, space exploration, and other high-value defense and civil applications., A comprehensive computational analysis of energetic materials allowed the drawing of thermostability guidelines, inspiring the design of new thermostable explosives, which were synthesized and evaluated.

Bimetallic iron oxides (NiFe2O4, ZnFe2O4 and CoFe2O4) were prepared via the facile solvothermal method and characterized using SEM, TEM, XRD, FTIR, XPS and BET instruments. The catalytic behavior of the bimetallic iron oxides on the thermal decomposition of 5, 5′-bistetrazole-1, 1′-diolate (TKX-50) was studied using DSC and TG-DTG methods. Besides, the corresponding kinetic parameters of TKX-50 thermal decomposition were calculated by multi-kinetics methods including traditional, iso-conversional and iteration methods. The thermal decomposition peak temperature (Tp) and the activation energy (Ea) reduced obviously after the addition of bimetallic iron oxides. Among different bimetallic iron oxides, the ZnFe2O4 has the best catalytic activity for TKX-50 thermal decomposition. The high thermal decomposition peak temperature (THDP) and average apparent activation energy (Ea) of TKX-50 were decreased by 47.0 °C and 34.34 kJ mol−1 in the presence of ZnFe2O4 sample. The excellent catalytic activity of ZnFe2O4 for thermal decomposition of TKX-50 makes it a promising combustion catalyst of insensitive solid propellants containing TKX-50.

Despite the well-characterised mechanisms of amino acids (AA) regulation of milk protein synthesis in mammary glands (MG), the underlying specific AA regulatory machinery in bovine MG remains further elucidated. As methionine (Met) is one of the most important essential and limiting AA for dairy cows, it is crucial to expand how Met exerts its regulatory effects on dairy milk protein synthesis. Our previous work detected the potential regulatory role of seryl-tRNA synthetase (SARS) in essential AA (EAA)-stimulated bovine casein synthesis. Here, we investigated whether and how SARS participates in Met stimulation of casein production in bovine mammary epithelial cells (BMEC). With or without RNA interference against SARS, BMEC were treated with the medium in the absence (containing all other EAA and devoid of Met alone)/presence (containing 0·6 mm of Met in the medium devoid of Met alone) of Met. The protein abundance of β-casein and members of the mammalian target of rapamycin (mTOR) and general control nonderepressible 2 (GCN2) pathways was determined by immunoblot assay after 6 h treatment, the cell viability and cell cycle progression were determined by cell counting and propidium iodide-staining assay after 24 h treatment, and protein turnover was determined by l-[ring-3H5]phenylalanine isotope tracing assay after 48 h treatment. In the absence of Met, there was a general reduction in cell viability, total protein synthesis and β-casein production; in contrast, total protein degradation was enhanced. SARS knockdown strengthened these changes. Finally, SARS may work to promote Met-stimulated β-casein synthesis via affecting mTOR and GCN2 routes in BMEC.

Fe3O4/reduced graphene oxide (Fe3O4/rGO) nanocomposite has been successfully fabricated using a modified interface solvothermal method and characterized by X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. In the preparation procedure, graphene oxide was reduced and ultrafine Fe3O4 nanoparticles (NPs) were uniformly loaded on reduced graphene oxide (rGO) carrier. Scanning electron microscope, transmission electron microscope images and Brunauer–Emmett–Teller specific surface area revealed that the aggregation of Fe3O4 NPs was greatly reduced by introducing rGO as a substrate. The average size of the Fe3O4 NPs anchored on the graphene sheets was 100 nm, which is much smaller than 1-μm bare Fe3O4. The DSC results showed that Fe3O4/rGO nanocomposite reduces the first decomposition temperature of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) by 44.9 °C and decreases the apparent activation energy of TKX-50 by 26.2 kJ mol−1, which exhibits higher catalytic performance than its individual components and their physical mixture (hybrid). Hence, Fe3O4/rGO nanocomposite can be a promising additive for insensitive solid propellants based on TKX-50.

Molecular dynamics simulation on the reaction of nano-aluminum particle and water were performed by ReaxFF force field. The different reaction rates of aluminum with H2O and D2O indicate that the effect of kinetic isotope effect (KIE) is obvious. The generation rate of H2 is 20% higher than that of D2. The mechanism of formation and consumption of AlH3 as well as the generation of Al2O3 are elucidated. Specifically, the most frequent reaction pathways throughout the full period are clarified based on the changes of numbers of intermediate and final products. The reactions in the early period are endothermic and release isolated H atoms, which involves Al +3H2O → Al(OH)3 + 3H and 3Al + 2H2O → 2AlO + AlH3 + H. Afterwards, the reactions release a large amount of energy and generate H2 molecules in the later period, in accordance with the equations of 2AlO + H2O → Al2O3 + H2, Al(OH)3 + AlH3 → Al2O3 + 3H2 and 2AlH3 + 3H2O → Al2O3 + 6H2. The initial pathways are in agreement with early DFT investigations. The diffusion coefficients of the different atoms show that the replacement of H2O by D2O reduces the diffusion rate of all the atoms (5%) in the system. The KIE is confirmed, and the results agree with experiments. In addition, the simulations were performed under different maximum temperatures. Results show that the solid residues become more disperse in space as the temperature increase.

This study was to compare the effects of parenteral supplementation of methionyl-methionine (Met-Met) or Met on intestinal barrier function in Met-deficient pregnant mice. Pregnant mice were randomly divided into three groups. The Control group was provided a diet containing Met and received i.p. injection of saline. The Met group was fed the same diet but without Met and received daily i.p. injection of 35% of the Met contained in the control diet. The Met-Met group was treated the same as the Met group, except that 25% of the Met injected was replaced with Met-Met. Met-Met promoted villus surface area in ileum compared with Met alone. In addition, the mRNA abundance of amino acid and glucose transporters in the small intestine was altered with Met-Met. Moreover, Met-Met increased tight junction protein and decreased apoptosis-related proteins expression in the jejunum and ileum. These results suggest that Met-Met can promote intestinal function over Met alone in Met-deficient mice.

The thermal decomposition behaviors of 1,3-di (azido-acetoxy)-2-methyl-2-nitropropane (DAMNP) under pressures of 0.1 MPa and 3.0 MPa were investigated by DSC techniques. The results showed that with the increase in pressure, the decomposition heat increased significantly, while the peak temperature increased slightly. The kinetic and thermodynamic parameters of exothermic decomposition reaction were obtained, and the iso-kinetic point was found as 192.0 °C. Using the thermal decomposition parameters, the self-accelerating decomposition temperature and the critical temperature of thermal explosion were calculated to be 190.10 °C and 202.58 °C, respectively. The specific heat capacity of DAMNP was studied with micro-DSC method, and the molar heat capacity was found to be 531.98 J mol−1 K−1. The adiabatic time-to-explosion was calculated to be 75.67 s. The combustion heat of DAMNP was determined with an oxygen bomb calorimeter, and the standard molar enthalpy of formation was calculated to be − 189.46 kJ mol−1. These results are important in evaluating the thermal stability and application prospects of DAMNP.