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Recently, the micromechanical exfoliation method has effectively separated the two-dimensional (2D) SiP 2 flake, which exhibits superior performance in field-effect transistors and photodetectors. In this paper, first-principles calculations were utilized to investigate the phononic properties of a SiP 2 monolayer, which would be significant to explain the thermal deformation of 2D SiP 2 -based devices. We found that the acoustic phonon branches of SiP 2 monolayer demonstrate significant in-plane anisotropy. The anisotropic ratios for the group velocities are 2.41 and 1.66 for the longitudinal and transverse acoustic modes, respectively. Meanwhile, the anisotropic ratio of the negative thermal expansion coefficient only considering the contribution from acoustic phonons is 0.14, while this ratio is ∼0.279 occurs at 120 K when both acoustic and optical phonons are taken into account. For the Raman-active optical phonons, the largest Grüneisen constant of these Raman-active phonons reaches 22.76, while the largest anisotropic ratio of phonon frequency is up to 2.16. To interpret this significant in-plane anisotropy, we calculated the electron density distribution, crystal orbital Hamilton populations (COHP) and interatomic force constants (IFCs), and found the maximal IFC in the x -direction is 5.79 times greater than y -direction, suggesting it as a major origin of the phononic anisotropy. • The significant anisotropic ratios for the thermal expansion constant of SiP 2 monolayer is 0.279 at 120 K. • All the optical phonons are Raman-active with unusual Grüneisen constants. The largest Grüneisen constant is 22.76. • The major origin of in-plane anisotropy is the interatomic force constant with anisotropic ratio of 5.79. [ABSTRACT FROM AUTHOR]

• (3-Aminopropyl) triethoxysilane with 1,4-Butane sultone to obtain zwitterionic silane (ZSi). • ZSi is grafted onto nano-hydroxyapatite (nHA) to obtain nHA-ZSi. • nHA-ZSi reduces the crystallization of the polymer matrix due to filler effect. • The specific capacitance increases with the addition of nHA-ZSi; reaches the maximum at 20%. In this study, we intend studying the role of nano-hydroxyapatite bearing zwitterion within carboxylated chitosan hydrogel electrolyte in improving supercapacitor performance. First, we carry out the ring-opening addition of (3-Aminopropyl) triethoxysilane with 1,4-Butane sultone to obtain zwitterionic silane (ZSi). Then, ZSi is grafted onto nano-hydroxyapatite (nHA) by condensation process to obtain nano-hydroxyapatite grafted zwitterionic silane (nHA-ZSi). The successful synthesis of nHA-ZSi is confirmed by Fourier transform infrared spectroscopy and 13C Nuclear magnetic resonance. Differential scanning calorimetry shows that the incorporation of nHA-ZSi reduces the crystallization of the polymer matrix due to filler effect. Afterwards, nHA-ZSi with 5%, 10%, 20%, 30% are mixed with carboxylated chitosan (CCS) to obtain composite films (CCS/nHA-ZSi). The stress-strain curves of CCS/nHA-ZSi are characterized by tensile testing. Ionic conductivities of hydrogel electrolytes are estimated by soaking CCS/nHA-ZSi in 1 M Na 2 SO 4 via electrochemical impedance. Furthermore, CCS/nHA-ZSi hydrogel electrolytes are assembled with symmetric carbon electrode for electrochemical tests, including cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance. The specific capacitance increases with the addition of nHA-ZSi; reaches the maximum at 20%; and then decreases due to aggregation. After 5000 cycles, CCS/20% nHA-ZSi supercapacitor has 98% capacitance retention at 6 mA/cm2. This study demonstrates that nano-hydroxyapatite bearing zwitterion is a beneficial additive for both mechanical strength and ionic conductivity in hydrogel electrolytes. [Display omitted] [ABSTRACT FROM AUTHOR]

Urease were known to catalyze the conversion of urea to ammonia and carbon dioxide. Microbial urease has demonstrated its benefits in wide biotechnological, agricultural, medicinal and engineering application. There are number of diverse microbial species contribute to urease activity in different natural habitats like soil, ocean and in various geological formation. For this study, urease bacteria were screened and isolate from acidic peat in Sarawak, Malaysia. Five distinct and diverse bacterial strains that were able to produce urease constitutively were selected to be characterized with respect to morphology, biochemical test, growth conditions and urease activity. The selected strain showed their capability to precipitate calcium carbonate (CaCO 3 ). Hence, the isolates could be potential source of acid ureases that can be use in various industrial utilizations. 16S rRNA sequencing and phylogenetic analysis found that the selected isolates belong to the genus of Bacillus . [ABSTRACT FROM AUTHOR]

Manganeses oxides (MnO x ) with different crystal and structural properties were prepared by the precipitation, the complex-decomposition, and the thermal decomposition methods, respectively. The materials were characterized by XRD, SEM, TEM, H 2 -TPR, TG-DSC, XPS, and N 2 adsorption/desorption at low temperatures. The samples were comparatively evaluated as catalysts for the oxidative dehydrogenation of ethylbenzene with carbon dioxide (CO 2 -ODEB). Results indicate that both Mn 2 O 3 and Mn 3 O 4 were active for CO 2 -ODEB and the Mn 3 O 4 prepared by the precipitation method showed the highest conversion of ethylbenzene over 60%. Moreover, the activity of MnO x for CO 2 -ODEB was significantly affected by the synthesis method and parameters of the oxides. The correlation between the reaction and characterization results indicates that the CO 2 -ODEB over MnO x may follow the redox mechanism involving the lattice oxygen, and the amount of the mobile oxygen species and the surface area were revealed to be key factors in determining the activity of the MnO x catalysts for the titled reaction. Together with the characterization results of XRD, TG-DSC, and H 2 -TPR, the irreversible reduction of MnOx to MnO under the conditions of CO 2 -ODEB was the main reason for the deactivation of the catalyst while the coke deposition had a less important impact on the stability of the catalyst. [ABSTRACT FROM AUTHOR]

Persimmon ( Diospyros kaki L.) leaves are extensively used in Chinese medicine and are also excellent source of dietary polyphenols. Here we investigated the antiproliferative and pro-apoptotic activity of the total flavonoids extracted from persimmon leaves (FPL) in PC-3 cells. After treating cells with different concentration of FPL, Quercetin or Rutin for 24 h, MTT and flow cytometry were used to measure the cytotoxicity, apoptotic rate and cell cycle arrest. Compared with Quercetin and Rutin, FPL showed higher cytotoxicity at 12.5 and 25 μg/ml concentrations and also presented lower IC 50 in PC-3 cells. In addition, FPL induced PC-3 cells apoptosis by activation of oxidative stress, as detected by ROS, MDA, nitrite and iNOS activity, and increased mitochondrial membrane permeability. Morphological changes, inactivation of Bcl-2, upregulation of BAX, release of cytochrome c and activation of downstream apoptotic signaling in FPL-treated PC-3 cells also suggested apoptotic death. Meanwhile, FPL significantly inhibited migration of PC-3 cells. Therefore, FPL inhibited proliferation, migration and induced apoptosis of PC-3 cells by activation of oxidative stress and mitochondrial-related apoptosis. [ABSTRACT FROM AUTHOR]

This work studied the anti-penetration performance and energy absorption characteristics of the honeycomb aluminum core structure. Tests of penetrating depth were conducted. The response and deformation resistance of the aluminum sandwich structure with a regular hexagonal honeycomb were studied through numerical simulation. The effect of the face/back plate thickness ratio and the shape of the core layer unit on the performance of the aluminum sandwich structure with a regular hexagonal honeycomb were compared and analyzed with a theoretical model of equivalent target calculation. Based on the results, the aluminum sandwich structure with a regular hexagonal honeycomb has the strongest anti-penetration capability when the thickness ratio of the face/back plate is set to 2.5:1. In terms of the energy consumption, the Arrow and concave hexagonal honeycomb aluminum sandwich structures are 14.7% and 25.9%, respectively, than the aluminum sandwich structure with a regular hexagonal honeycomb. The typical hierarchical honeycomb aluminum sandwich structure has better energy absorption characteristics than the aluminum sandwich structure with a regular hexagonal honeycomb. Therefore, the anti-penetration performance of the honeycomb aluminum sandwich structure can be improved by adjusting the thickness ratio of the face/back plate and changing the shape of the core layer. The research results are of great significance in guiding the design of the honeycomb aluminum sandwich structure. [ABSTRACT FROM AUTHOR]

Fish schooling is a common phenomenon that is assumed to have energy advantages, and various fish schooling configurations have been observed. However, the underlying mechanism of fish schooling remains an open question. To understand the relationship between energetically advantageous formations and swimming modes, we numerically investigated two self-propelled fish at different initial spacings. Stable beneficial formations were classified into three types, based on the benefiting individuals. The analysis focused on the intrinsic mechanisms of individual benefit for the three types of energetically beneficial formations in terms of the swimming performance, velocity clouds, and vortex evolution. For the first type, both fish benefited from parallel formations as the carangiform swimming mode promoted fluid flow and reduced lateral power because of the channel effect. For the second type, the front fish gained an efficiency advantage from pressure and vortex mechanisms, while the rear fish was almost indistinguishable from the swimming-alone condition in the sinusoidal and anguilliform swimming modes. For the last type, similar to the tandem queue, the rear fish modulated the vortex and gained an energy advantage in the carangiform and anguilliform swimming modes. This study provides new insights into the appropriate configuration of fish for different swimming modes in nature. • The stable beneficial formations were classified into three types, based on the benefiting individuals. • Type I, both fish in the carangiform swimming mode benefited from parallel formations using the channel effect. • Type II, the front fish gained an efficiency advantage in the sinusoidal and anguilliform swimming modes. • Type III, the rear fish gained an energy advantage in the carangiform and anguilliform swimming modes. [ABSTRACT FROM AUTHOR]

It is a long-held perception that fish may obtain a hydrodynamic advantage from clustering. This study attempts to determine whether all the fish in school gain the same energy advantage in different swimming modes. The numerical investigation based on two self-propelled fish arranged in tandem in carangiform, anguilliform, and sine curve swimming modes was conducted. It was found that fish could spontaneously form different steadily spaced queues, and discrete points of stable spacing were classified as proximity and wake interference points according to their swimming speed. The stable points were the result of the combined effect of wake impact and vortex modulation. From the carangiform to anguilliform to sine curve swimming modes, as the head amplitude increased, the vortex modulation of the rear fish gradually decreased, while the wake impact gradually increased. Therefore, the rear fish in carangiform swimming mode had lower energy consumption than that of the front, whereas the opposite was true in sine curve swimming mode. In addition, some interesting phenomena related to the vortex core arrangement were introduced at different stable points in these three swimming modes. The present results may enrich the scope of research on the hydrodynamic dominance of aquatic organisms in collective behaviour. • The two self-propelled fish arranged in tandem form a different steadily spaced queue in different swimming modes. • The stable points can be classified as the proximity and wake interference points. • The stable point was the result of the combined effect of wake impact and vortex modulation with different swimming modes. [ABSTRACT FROM AUTHOR]