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Two-dimensional (2D) magnetic materials are the key to the development of the new generation in spintronics technology and engineering multifunctional devices. Herein, the electronic, spin-resolved transmission, and gas sensing properties of the 2D g-C 4 N 3 /MoS 2 van der Waals (vdW) heterostructure have been investigated by using density functional theory with non-equilibrium Green's function method. First, the g-C 4 N 3 /MoS 2 vdW heterostructure demonstrates ferromagnetic half-metallicity and superior adsorption capacity for gas molecules. The spin-dependent electronic transport of the g-C 4 N 3 /MoS 2 -based nanodevice is obviously regulated by parallel or anti-parallel spin configuration in electrodes, leading to perfect single-spin conduction behavior with a nearly 100% spin filtering efficiency, a negative differential resistance effect, and other interesting electrical transport phenomena. Moreover, g-C 4 N 3 /MoS 2 exhibits directional dependency and strong transport anisotropic behavior under bias windows, indicating that the electric current propagates more easily through the vertical direction than the horizontal direction. The physical mechanisms are revealed and analyzed by presenting the bias-dependent transmission spectra in combination with the projected local device density of states. Finally, the g-C 4 N 3 /MoS 2 -based gas sensor is more sensitive to CO, NO, NO 2 , and NH 3 molecules with the chemisorption type. The strong chemical adsorption leads to the formation of electrons on the local scattering center and ultimately affects the transport properties, resulting in the maximum gas sensitivity reaching 6.45 for NO at the bias of 0.8 V. This work not only reveals that the g-C 4 N 3 /MoS 2 vdW heterostructure with high anisotropy, perfect spin filtering, and outstanding gas sensitivity is a promising 2D material but also provides an insight into the further application in futuristic electronic nanodevices.

We study the properties of edge states for a selected (10,1)[(4,3)] twisted bilayer graphene (TBG) nanoribbon with minimal edges but a majority of zigzag edges. By using the tight-binding and Green's function methods, we find a remarkable rule of a local electronic transfer for the edge states. As the energy away from the Fermi level, the transfer is in the order of convex AB-, concave AB-, concave AA- and convex AA-stacked regions of the ribbon curve edges. We illustrate that this rule comes from the difference in interlayer couplings among the four types of local geometries at edges. Further, an in-plane transverse electric field can rearrange the edge bands and enlarge the energy regimes, leading to the lowest energy states modified from AB-stacked edge states to AA-stacked ones. The realignment of the edge bands results from the interplay between the interlayer coupling and the potential difference induced by the transverse electric field, which results in different bonding and antibonding edge states, i.e. the edge bands. In contrast, the total energy regime of the edge bands remain nearly unchanged under a relative strong off-plane perpendicular electric field, and the typical AA-stacked edge states are still maintained even the rotational symmetry of two layers is broken. Until a sufficiently strong value, the TBG nanoribbon tends to behave as two noninteracting monolayer ribbons except for a band distortion in low-energy regime. The conductance spectra reflects the edge bands well. We also discussed the influence of edge defects in the TBG nanoribbon on transport properties. It is found that the contributed conductance of each type of edge states shows different degrees of suppression for a monatomic vacancy in the corresponding region of edges., (© 2022 IOP Publishing Ltd.)

Objectives: Rotavirus (RV) is one of the most significant pathogens associated with childhood diarrhoeal deaths worldwide. Elevated cytoplasmic calcium is required for RV replication, but the underlying mechanisms responsible for calcium influx remain poorly understood. The Calcium-sensing receptor (CaSR) is an important Ca 2+ sensor that regulates the transport of Ca 2+ into or out of the extracellular space by affecting the status of Ca 2+ ion channels on the membrane of cells. Currently, the function of CaSR in RV replication is unclear., Materials and Methods: We evaluated the mRNA and protein levels of CaSR in RV-infected cells using qRT-PCR and Western blotting, respectively. Furthermore, we silenced or overexpressed CaSR in Caco-2 cells using siRNA or a CaSR gene contained adenovirus (Adv-CaSR). qRT-PCR, plaque assay, and Western blotting were used to determine the synthesis of virus genomic RNA, production of progeny virion, and the levels of viral proteins. The content of Ca 2+ in cells was observed under confocal microscopy., Results: Compared with control cells, the RV-infected cells presented significantly decreased CaSR expression. Moreover, adenoviral-mediated over-expression or induction of CaSR by R568 greatly inhibited the RV RNA synthesis, protein expression, and formation of viroplasm plaques, thereby suppressing RV replication. In contrast, CaSR-silenced cells exhibited significantly enhanced RV replication. Compared with the Adv-Control group, the concentration of cytosolic Ca 2+ significantly decreased in the Adv-CaSR group., Conclusion: These findings demonstrated that CaSR is a potential target for inhibition of RV replication. Therefore, enhancing the expression of CaSR might protect hosts from RV infections., Competing Interests: The authors declare that they have no competing interests.

The present analysis was to summarize the evidence of the effects of sesame and its derivatives supplementation on cardiovascular disease (CVD) risk factors by performing a meta-analysis of randomized controlled trials (RCTs). Electronic databases were searched from their inception to July 2020. Two investigators independently assessed articles for inclusion, extracted data, and statistical analysis. The quality of included articles was assessed according to the Cochrane risk of bias tool. Major outcomes were synthesized using a random effect model and presented as weighted mean difference and 95% confidence interval. Heterogeneity, subgroup analyses, sensitivity analysis, meta-regression, and publication bias were also conducted. The GRADE approach was used to evaluate the quality of evidence. Overall, 16 trials involving 908 participants were included for statistical pooling. Compared with the control group, sesame intake significantly decreased the levels of total cholesterol, triglycerides, systolic blood pressure, diastolic blood pressure, body weight, body mass index, hip circumference, and waist circumference ( P  < 0.05). These results were stable in sensitivity analysis, and no significant publication bias was detected. Our findings provided evidence that sesame consumption may reduce the risk of CVD by improving blood lipids, blood pressure, and body weight management. Further large-scale, well-designed RCTs are required to confirm these results.

Background: An increasing number of studies have indicated that uncomplicated acute appendicitis can be cured with antibiotics alone. Reducing the hazards of appendicitis in infants and young children is a priority problem. It is necessary to search for potential biomarkers for early diagnosis of appendicitis in infants and young children., Methods: A retrospective cohort study, including 366 infants and young children treated in the pediatric surgery department, was conducted. Complete blood count, C-reactive protein, and procalcitonin were measured at admission and 24 hours after operation., Results: The median of PCT, CRP, and WBC in the acute appendicitis group and other diseases group were 1.20, 0.11 - 4.06; 16.50, 0.81 - 76.21; 13.51, 7.53 - 26.30 and 0.03, 0.01 - 0.13; 3.35, 0.92 - 6.33; 14.34, 8.84 - 17.23 at the admission, respectively. PCT and CRP were found higher in the acute appendicitis group than that in other abdominal pain diseases group (p < 0.05). WBC is not a specific indicator for identifying acute appendicitis and other abdominal pain diseases (p > 0.05). In different acute appendicitis cases, PCT and CRP significantly increased in complicated appendicitis (p < 0.05). Data showed that WBC mildly increased in complicated appendicitis compared to acute simple appendicitis (p < 0.05). ROC curves showed that PCT was a specific indicator for identifying acute appendicitis and other abdominal pain diseases, AUCPCT = 1.000 (95% CI, 0.999 - 1.000). The median of antibiotic treatment is 4.0 d (95% CI 3.0 - 5.0) in acute appendicitis with PCT results versus 7.0 d (95% CI 5.0 - 9.0) in acute appendicitis without PCT result., Conclusions: PCT shows a high diagnostic ability for appendicitis in infants and young children at admission and assists pediatricians in management of pediatric appendicitis. The combination of these biomarkers is highly recommended. Further studies are needed to confirm our findings.

B-site Os-doped quadruple perovskite oxides LaCu 3 Fe 4- x Os x O 12 ( x = 1 and 2) were prepared under high-pressure and high-temperature conditions. Although parent compound LaCu 3 Fe 4 O 12 experiences Cu-Fe intermetallic charge transfer that changes the Cu 3+ /Fe 3+ charge combination to Cu 2+ /Fe 3.75+ at 393 K, in the Os-doped samples, the Cu and Fe charge states are found to be constant 2+ and 3+, respectively, indicating the complete suppression of charge transfer. Correspondingly, Os 6+ and mixed Os 4.5+ valence states are determined by X-ray absorption spectroscopy for x = 1 and x = 2 compositions, respectively. The x = 1 sample crystallizes in an Fe/Os disordered structure with the Im 3̅ space group. It experiences a spin-glass transition around 480 K. With further Os substitution up to x = 2, the crystal symmetry changes to Pn 3̅, where Fe and Os are orderly distributed in a rocksalt-type fashion at the B site. Moreover, this composition shows a long-range Cu 2+ (↑)Fe 3+ (↑)Os 4.5+ (↓) ferrimagnetic ordering near 520 K. This work provides a rare example for 5d substitution-suppressed intermetallic charge transfer as well as induced structural and magnetic phase transitions with high spin ordering temperature.

The α - T 3 lattice, a minimal model that presents flat bands, has sparked much interest in research but the finite-size effect and interaction has been rarely involved. Here we theoretically study the electronic structure and transport properties of zigzag-edge α - T 3 nanoribbons (Z αT 3 NRs) with and without uniaxial strain, where the exemplary widths N = 40 and 41 for two series are considered. By adopting the mean-field Hubbard model combined with the nonequilibrium Green's function method, we show that the spin-degenerate dispersionless flat band at the Fermi energy for the pristine ribbons is split into spin-up and -down flat bands under electron-electron Coulomb interaction. Specifically, the two bands are shifted toward in an opposite direction and away from the Fermi energy, which leads to an energy gap opening in the case of α ≠ 1. All three series of Z αT 3 NRs with width N = 3 n , 3 n + 1, 3 n + 2 (where n is a positive integer) exhibit an energy gap. This differs from the simple tight-binding calculations without considering electron-electron Coulomb interaction, for which the gap is always zero in the case of N = 3 n + 1. Here, the origin of the energy gap for N = 3 n + 1 arises from Coulomb repulsion between electrons. Importantly, the energy gap can be effectively manipulated by an uniaxial strain and Coulomb interaction if α ≠ 1. The gap linearly increases (decreases) when a tensile (compressive) strain increases, and it also monotonously increases as enhancing Coulomb interaction. Interestingly, a ground state of antiferromagnetic to ferromagnetic transition occurs when α increases from 0.8 to 1, leading to a semiconductor to metallic transition. Besides, the α -, strain- and interaction-dependent conductance is also explored. The findings here may be of importance in the band gap engineering and electromechanical applications of α - T 3 nanoribbon-based devices., (© 2021 IOP Publishing Ltd.)

A carbon phosphide (CP) monolayer, a 2D structure derived from the same 3-fold coordination found both in graphene and phosphorene, has been successfully synthesized in an experiment recently. In this paper, we investigated the modulation of electronic structures and transport characteristics of 2D nanosheets and quasi-1D nanoribbons of CP nanomaterials in the α-phase by using first-principles density functional theory simulation. The calculated band structures show that the band gap of 2D CP nanosheets progressively increases as the uniform biaxial strain changes from compression to stretching. However, the biaxial strain cannot change the indirect band gap behavior of the original 2D CP nanosheet. In addition, the band structures of quasi-1D nanoribbons with different styles of H-passivated zigzag edges have also been studied. The results show that the H-passivated zigzag PC ribbons with two P edges are semiconductors with indirect band gaps, and the gaps decrease with increasing width of ribbons. However, the H-passivated CP nanoribbons with one P-atom terminated edge in combination with one P-atom edge, and H-passivated CC nanoribbons with two C-atom terminated edges display metallic behaviors. The semi-conductive or metallic behaviors of zigzag CP nanoribbons can be explained by presenting the wave function of their energy band around the Fermi level. Finally, the electronic transport properties of different CP nanoribbon based nanojunctions are studied in which arise the interesting negative differential resistance or rectification effects in their current-voltage characteristic curves.

We theoretically investigate the Landau levels (LLs) and magneto-capacitance (MC) of monolayer black phosphorus under a perpendicular magnetic field, on which a parabolic potential is applied along with the armchair and zigzag directions, respectively. By both analytically perturbative calculation and numerical diagonalization based on an effective k ⋅ p Hamiltonian, we find that the LLs parabolically depend on the wave vectors and show strong anisotropy as the parabolic potential is applied along with different crystal directions. Specifically, the analytical LLs obtained by perturbative calculation from a decoupled single-band Hamiltonian are in good agreement with the numerical results. Importantly, the LLs are no longer linearly dependent on the magnetic field and level index even in the low energy regime due to the confinement of parabolic potential which repaints the cyclotron orbits. Moreover, the MC spectrum clearly reflects the structure of the LLs and exhibits strong anisotropic oscillating patterns. It can be used to determine the band parameters of phosphorene, i.e., the effective masses and inter-band coupling in the absence of magnetic and electric fields., (© 2020 IOP Publishing Ltd.)

We theoretically investigate the electronic structure and optical absorption spectrum of armchair-edged black phosphorene nanoribbons (APNRs) with and without uniaxial strain based on the tight-binding Hamiltonian and Kubo formula. We analytically obtain the energy spectrum and wavefunction, and reveal the band gap scaling law as 1/(N + 1) 2 for APNRs in the presence and absence of uniaxial strain, where N is the number of armchair dimer across the ribbon. We find the band gap of APNRs linearly increases (decreases) with increasing in-plane uniaxial tensile (compressive) strain ɛ x/y , but shows contrary dependence on the out-of-plane uniaxial strain ɛ z . The effective mass versus strain exhibits the same behavior to that of band gap but with nonlinear dependence. Under an incident light linearly-polarized along the ribbon, we demonstrate that the inter-band optical transitions obey the selection rule Δn = n - n' = 0, but the intra-band transitions are forbidden for both pristine and strained APNRs originating from the orthogonality between the transverse wavefunctions of the sublattices belonging to different subbands. Importantly, the transverse electric field or impurities can release the optical selection rules by breaking the wavefunction orthogonality, which results in that the optical transitions between any subbands are all possible. Our findings provide further understanding on the electronic and optical properties of APNRs, which may pave the way for designing optoelectronic devices based on phosphorene.

Piperine (Pip) has been widely studied for its multiple activities such as antidepressant, anti-epileptic, and so forth. However, the poor water solubility coupled with low bioavailability may inevitably hinder the application of Pip in the clinical setting. In this study, a formulation strategy was proposed to spontaneously resolve the low bioavailability and dose dividing issue of Pip. The matrix pellets (Pip-SR-pellets) consisting of Pip solid dispersion (Pip-SD) and hydroxypropylmethyl cellulose-K100 were developed to achieve an increased and sustained release profile in vitro . The Pip-SR-pellets were compacted into fast disintegrating tablets (FDTs) with a blend of excipients comprising lactose, MCC, LS-HPC, and CMS-Na. The Pip-SD was characterized by solubility study and XRD. The evaluation of the cross-sectional morphology of the Pip-FDTs via scanning electron microscope proved that Pip-SR-pellets maintained its structural integrity during compression and were uniformly distributed in the Pip-FDTs. The release profile of Pip-SR-pellets was highly consistent with the Pip-FDTs. In vivo pharmacokinetics study demonstrated that the relative bioavailability of Pip-SR-pellets was approximately 2.70-fold higher than that of the pure drug, and 1.62-fold compared with that of Pip-SD. This work therefore showed a potential industrialized method could be applied to formulate poorly water-soluble drug that has dose-dividing requirement.

An ilmenite-like monoclinic phase of HgMnO 3 with space group P 2 1 / c was prepared using high-pressure and high-temperature methods at 18 GPa and 1473 K. The MnO 6 octahedra form a two-dimensional (2D) network in the bc plane, leading to a long-range antiferromagnetic ordering with a low Néel temperature of T N ∼ 32 K. As the synthesis pressure increases to 20 GPa, a new perovskite-like rhombohedral phase with space group R 3̅ c was found to occur. The rhombohedral phase exhibits a three-dimensional (3D) network for the MnO 6 octahedra, giving rise to an antiferromagnetic ordering at T N ∼ 60 K. X-ray absorption spectroscopy confirms the invariable Mn 4+ charge state in these two polymorphic phases, in agreement with the Curie-Weiss and bond valence sum analysis. HgMnO 3 provides an interesting example to study the magnetic properties from 2D to 3D by varying synthesis pressure.

Motivated by the recent successful growth of quasi-free-standing single layer blue phosphorus (BlueP) on tellurium functionalized Au(1 1 1) by using black phosphorus as the precursor (Zhang et al 2016 Nano Lett. 16 4903; Gu et al 2017 ACS Nano 11 4943), here we study the strain performance for zigzag BlueP nanoribbons (zBluePNRs) with different edge chemical modifications. Based on the first-principles calculations, interestingly, we find that a narrow zBluePNR of width up to  ∼2 nm with edge sulfur (S) passivation under an uniaxial strain exhibits an important effect of negative Poisson's ratio because of the particularity of the P-S bonds at edges, and as the ribbon width further increases the Poisson's ratio varies from negative to positive. Meanwhile, the S-passivation also induces magnetism, and applying a strong enough strain can transfer this zBluePNR from magnetic metal state to half-metal one. All these physical properties are discussed in connection with the variation of microstructure of the ribbons. Our findings may paving the way for both a fundamental understanding of nanoscale physics and applied device engineering.

We study the electron transport properties through the junction of a benzene molecule in conjunction with two monolayer zigzag-edged phosphorene nanoribbon (ZPNR) electrodes by applying the nonequilibrium Green's functions in combination with the density functional theory. We find that the molecular junction with two phosphorus-carbon bonds exhibits an interesting low-bias negative differential resistance effect with a peak-to-valley ratio of 29, which originates from the edge states in ZPNR due to the anisotropic band structure of phosphorene. Importantly, the performance of the junction can be tuned via the molecule-ZPNR interface bonding. The findings may be useful in sensitive-device applications. Furthermore, the physical mechanisms are revealed and discussed in terms of the electronic transmission spectrum, the evolution of the frontier molecular orbitals, the local device density of states around the Fermi level, and the projected density of states.

We theoretically calculate the spin-dependent transmission probability and spin Seebeck coefficient for a zigzag-edge graphene nanoribbon p-n junction with periodically attached stubs under a perpendicular magnetic field and a ferromagnetic insulator. By using the nonequilibrium Green's function method combining with the tight-binding Hamiltonian, it is demonstrated that the spin-dependent transmission probability and spin Seebeck coefficient for two types of superlattices can be modulated by the potential drop, the magnetization strength, the number of periods of the superlattice, the strength of the perpendicular magnetic field, and the Anderson disorder strength. Interestingly, a metal to semiconductor transition occurs as the number of the superlattice for a crossed superlattice p-n junction increases, and its spin Seebeck coefficient is much larger than that for the T-shaped one around the zero Fermi energy. Furthermore, the spin Seebeck coefficient for crossed systems can be much pronounced and their maximum absolute value can reach 528 μV [Formula: see text] by choosing optimized parameters. Besides, the spin Seebeck coefficient for crossed p-n junction is strongly enhanced around the zero Fermi energy for a weak magnetic field. Our results provide theoretical references for modulating the thermoelectric properties of a graphene superlattice p-n junction by tuning its geometric structure and physical parameters.

Based on the tight-binding model and dual-probe scanning tunneling microscopy technology, we theoretically investigate the electronic structure and local property in the passivated AA-stacked bilayer armchair-edge graphene nanoribbons (AABLAGNRs). We show that they are highly sensitive to the size of the ribbons, which is evidently different from the single-layer armchair-edge graphene nanoribbons. The '3p' rule only applies to the narrow AABLGNRs. Namely, in the passivated 3p- and (3p  +  1)-AABLGNRs, the narrow ribbons are semiconducting while the medium and wide ribbons are metallic. Although the passivated (3p  +  2)-AABLGNRs are metallic, the '3j' rule only applies to the narrow and medium ribbons. Namely, electrons are in the semiconducting states at sites of line 3j while they are in the metallic states at other sites. This induces a series of parallel and discrete metallic channels, consisting of lines 3j  -  1 and 3j  -  2, for the low-energy electronic transports. In the passivated wide (3p  +  2)-AABLGNRs, all electrons are in the metallic states. Additionally, the '3p' and '3j' rules are controllable to disappear and reappear by applying an external perpendicular electric field. Resultantly, an electric filed-driven current switch can be realized in the passivated narrow and medium (3p  +  2)-AABLGNRs.

Relaxation of the inter- and intra-molecular interactions for the hydrogen bond (O:H-O) between undercoordinated molecules determines the unusual behavior of water nanodroplets and nanobubbles. However, probing such potentials remains unreality. Here we show that the Lagrangian solution [Huang et al., J. Phys. Chem. B, 2013. 117: 13639] transforms the observed H-O bond (x = H) and O:H nonbond (x = L) lengths and phonon frequencies (dx, x) [Sun et al., J. Phys. Chem. Lett., 2013. 4: 2565] into the respective force constants and bond energies (kx, Ex) and hence enables the mapping of the potential paths for the O:H-O bond relaxing with water cluster size. Results show that molecular undercoordination not only reduces the molecular size (dH) with enhanced H-O energy from the bulk value of 3.97 to 5.10 eV for a H2O monomer, but also enlarges the molecular separation (dL) with reduced O:H energy from 95 to 35 meV for a dimer. The H-O energy gain raises the melting point from bulk value 273 to 310 K for the skin and the O:H energy loss lowers the freezing temperature from bulk value 258 to 202 K for 1.4 nm sized droplet, by dispersing the quasisolid phase boundaries.

We study the quantum magnetotransport properties at low temperature for n-type monolayer MoS2 under a perpendicular magnetic field within the linear response theory. By using Kubo formula, it is predicted that the valley- and spin-resolved Hall conductance obeys the same rule as that for conventional fermions. However, the first Hall plateau and the longitudinal charge conductance in low energies are fully valley/spin-polarized, which may produce a pure valley/spin current. In the low magnetic field limit, importantly, the resistance as a function of field is in good agreement with the available experiment data. These interesting findings can be tested experimentally and may be useful for valleytronic and spintronic applications.