Because of graphene and phosphorene, two-dimensional (2D) layered materials of group IV and group V elements arouse great interest. However, group IV-V monolayers have not received due attention. In ...this work, three types of SiP monolayers were computationally designed to explore their electronic structure and optical properties. Computations confirm the stability of these monolayers, which are all indirect-bandgap semiconductors with bandgaps in the range 1.38-2.21 eV. The bandgaps straddle the redox potentials of water at pH= 0, indicating the potential of the monolayers for use as watersplitting photocatalysts. The computed optical properties demonstrate that certain monolayers of SiP 2D materials are absorbers of visible light and would serve as good candidates for optoelectronic devices.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We present a simple, robust, and cheap microfabrication method, based on thermally manipulating capillary action in poly(dimethylsiloxane) (PDMS) microholes, for preparing SU-8 curved ...microstructures. The microstructure morphology including convexity–concavity and curvature can be controlled via tuning the formation temperature. The convex SU-8 microspherical crowns with a height of 40 μm were formed at 10 °C, whereas the concave SU-8 microspherical crowns with a height of 90 μm were formed at 100 °C. The morphology of the microstructures is dictated by the thermally controlled combination of the pressure difference across the interface, contact angle, and surface tension. The fabricated microstructures with a spherical surface can be used as a microlens array or a mold for producing a microlens array. The clear and uniform images were observed using the generated microlens arrays. The equilibrium morphology of the microstructures can be predicted by numerical simulation, which can lessen the number of experiments and thus the design cost. The proposed method has the potential to find applications in industrial fields.
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IJS, KILJ, NUK, PNG, UL, UM
•PFOA treatment promotes ovarian cancer cell migration and invasion.•PFOA induces up-regulation of MMP2/9 expression in ovarian cancer cells.•PFOA induces activation of NF-κB through ERK1/2 ...phosphorylation.•Activation of ERK/NF-κB facilitates MMP2/9 expression, cell migration and invasion.
As widely used in consumer products, perfluorooctanoic acid (PFOA) has become a common environmental pollutant, which has been detected in human serum and associated with cancers. Our previous study showed that PFOA is a carcinogen that promotes endometrial cancer cell migration and invasion through activation of ERK/mTOR signaling. Here, we showed that PFOA (≥100 nM) treatment also stimulated A2780 ovarian cancer cell invasion and migration, which correlated with increased matrix metalloproteinases MMP-2/-9 expression, important proteases associated with tumor invasion and migration. Notably, PFOA treatment induced activation of ERK1/2/ NF-κB signaling. Pre-treatment with U0126, an ERK1/2inhibitor；or JSH-23, a NF-kB inhibitor, can reverse the PFOA-induced cell migration and invasion. Consistent with these results, inhibiting ERK1/2 or NF-κB signaling abolished PFOA-induced up-regulation of MMP-2/-9 expression. These results indicate that PFOA can stimulate ovarian cancer cell migration, invasion and MMP-2/-9 expression by up-regulating ERK/NF-κB pathway.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Forming bilayer or multilayer heterostructures via interlayer van der Waals interactions is a superior preparation strategy for two-dimensional heterojunctions. In this work, by employing density ...functional theory computations, we investigated heterostructured bilayers of transition-metal dichalcogenides (TMDs) (including MoS2, WS2, MoSe2, and WSe2) and MXene (exemplified by Sc2CF2) monolayer. All TMD and Sc2CF2 materials are hexagonal with little mismatch. Compared with separate TMD and Sc2CF2 monolayers, TMD–Sc2CF2 bilayers can be tuned to indirect semiconductors with the band gaps of 0.13–1.18 eV; more importantly, they are type-II heterostructures with the valence band maximum and conduction band minimum located at Sc2CF2 and TMDs, respectively. Stretching or compressing would reduce or enlarge the band gaps of the heterostructures, respectively. The tunable band structures make TMD–Sc2CF2 bilayers pomising candidates for electronic device applications.
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IJS, KILJ, NUK, PNG, UL, UM
As a significant stimulus, the external electric field (EEF) can change the decomposition mechanism and energy release of energetic materials (EMs). Hence, understanding the response of EMs to an EEF ...is greatly meaningful for their safe usage. Herein, the structural arrangement, a crucial factor in the impact sensitivity and detonation performance of EMs, under the EEF ranging from 0.0 to 0.5 V/Å was investigated via molecular dynamics simulation. Nitromethane (NM) was taken as a case study due to the simple structure. The simulation results show that there exists a critical EEF strength between 0.2 and 0.3 V/Å, which can induce the transition of NM molecules from relatively disordered distribution to solidlike ordered and compacted arrangement with a large density. In this ordered structure, NM dipoles are aligned in a head-to-tail pattern parallel to the EEF direction because of the favored dipole–dipole interactions and weak C–H···O hydrogen bonds. As the EEF strength is enhanced, the potential energy and cohesive energy density of the NM system gradually decrease and increase, respectively, indicative of high thermodynamics stability of ordered arrangement. The results reported here also shed light on the potential of the EEF to induce the nucleation and crystallization to explore new polymorphs of EMs.
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IJS, KILJ, NUK, PNG, UL, UM
Perfluorooctanoic acid (PFOA), a member of a group of polyfluorinated and perfluorinated alkyl substances (PFAS), is associated with adverse pregnancy outcomes in mammals. However, the effects of in ...vivo exposure to PFOA on the female reproductive system and the underlying mechanisms remain unclear. In our study, we constructed a mouse model to investigate whether low‐dose PFOA (1 mg/kg/day) or high‐dose PFOA (5 mg/kg/day) affect meiosis maturation of oocytes and the potential mechanisms that may be associated with oocyte maturation disorder. Our results indicate that low‐dose and high‐dose PFOA can lead to impaired oocyte maturation, which is manifested by decreased rate of embryonic foam rupture and first polar body extrusion. Moreover, PFOA exposure harmed the mitochondrial metabolic, resulting in low levels of ATP contents, high reactive oxygen species, aberrant mitochondrial membrane potential. In addition, the proportion of DNA damage marker γ‐H2AX was also significantly increased in PFOA exposure oocytes. These changes lead to abnormal arrangements of the spindle and chromosomes during oocyte maturation. In conclusion, our results for the first time illustrated that exposure to PFOA in vivo in female mice impaired the meiosis maturation of oocytes, which provided a basis for studying the mechanism of PFOA reproductive toxicity in female mammals.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
•Two novel high-energy compounds HANTT and ADNTT were achieved by facile amination of hygroscopic HDNTT, leading to the significant enhancement in thermal stability while maintaining excellent ...detonation performance and low sensitivity.•All new energetic compounds are insensitive to friction and impact.•The triaminoguanidinium salt of HANTT, with a good thermal stability (Td = 203 °C), demonstrates an excellent detonation velocity (vD = 8862 m s−1) surpassing that of RDX, attributing to its highest ΔfH (545.2 kJ mol−1) among all new compounds.•The low-cost and convenient three-step synthetic process with the overall yield exceeding 43 %, greatly promotes the potential application of these high-energy explosives with high stability.
The fine-tuning of the molecular structures of current explosives to reduce their inherent defects has proven to be an effective synthetic strategy for producing novel energetic compounds with superior overall performance. In this study, this strategy was adopted to modify the heat-labile nitro-substituted fused triazole through facile C-amination and N-amination, resulting in the synthesis of HANTT and ADNTT, respectively, both demonstrating a total yield exceeding 43 %. HANTT, ADNTT, and their derivates were fully characterized by IR, 1H and 13C spectroscopy, differential scanning calorimetry, thermal gravimetric analysis, and elemental analysis. NCI and Hirshfeld surfaces analysis were employed to explore the intermolecular interactions, while LOL-π, NICS, and ICSS analysis were performed to evaluate the aromaticity and stability of these compounds based on their respective single-crystal structures. Most of these insensitive compounds exhibit good thermostability (168–269 °C) and favorable detonation performances (20.2–32.1 GPa and 7679–8862 m s−1). Attributing to its highest heat of formation (545.2 kJ mol−1) among all new energetic compounds, triaminoguanidinium salt 6, with decent thermostability (Td = 203 °C), exhibits an excellent detonation velocity (vD = 8862 m s−1) superior to that of military benchmark explosives RDX (1,3,5-trinitro-1,3,5-triazacyclohexane), thus highlighting its potential as a high-energy insensitive explosive.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
As the perchlorate is embedded in the face-to-face stacking of completely planar fused-triazole caitions with strong hydrogen bonds, salt 3 exhibits high crystal density (1.939 g cm−3), excellent ...detonation performance (vD = 8719 m s−1, P = 32.9 GPa) and low sensitivity (IS > 40 J, FS = 216 N), which may well have promising applications as high-energy-density materials for replacement of RDX.
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A new family of nitrogen-rich fused-triazole energetic salts based on 3,6-diamino-1H-1,2,4triazolo4,3-b1,2,4triazole were synthesized and fully characterized by infrared spectroscopy (IR), 1H and 13C nuclear magnetic resonance, elemental analysis, differential scanning calorimetry (DSC). Structures of 3 and 4·H2O were confirmed by single-crystal X-ray diffraction analyses and their crystal packing characteristics were thoroughly analysed. All new compounds show good thermal stability (Td > 223 °C) and tend to be insensitive to external mechanical stimulus. The densities of these salts ranged from 1.72 to 1.93 g cm−3. Theoretical performance calculations (Gaussian 09 and EXPLO 5) provided detonation pressures and velocities within the ranges of 20.8 to 32.9 GPa and 7599 to 8719 m s−1, respectively. The perchlorate salt 3 exhibits the highest density (1.93 g cm−3) and best oxygen balance (−30.0%), good thermal stability (Td = 258 °C), low sensitivities, and excellent detonation velocity (8719 m s−1) and pressure (32.9 GPa), which suggest that it has the potential to be used as High-energy–density material.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Through first-principles computations, we investigated Li4NiTeO6, which is a new layered Ni-based cathode material for Li ion batteries, by focusing on the sequence of Li removal when it is charged. ...According to our computations, Li4NiTeO6 exhibits satisfactory structural stability with a volume change of 7.2% and electrical conductivity similar to Li2MnO3. We also examined the electronic configuration of this cathode material during its electrochemical progress and found a weak hybridization of Ni3d and O2p. Moreover, by analyzing the Bader charges of different elements, we confirmed that O and Ni are exclusively responsible for electron loss and gain. In addition, O evolution reactions occur when half of Li(+) ions are extracted. Finally, we investigated Li(+) migration paths and concluded that migration barriers depend on the charge distribution around migration paths.
