Optical properties of monolayer bismuthene in electric fields.

Optical excitations of monolayer bismuthene present very rich and unique absorption spectra. The optical energy gap corresponding to the threshold frequency is not equal to an indirect energy gap, and it becomes zero under the critical electric field. The frequency, number, intensity, and form of the absorption structures are dramatically changed when an external electric field is applied. The prominent peaks and the observable shoulders, respectively, arise from the constant-energy loop and the band-edge states of parabolic dispersions. These directly reflect the unusual electronic properties, being very different from those in monolayer graphene. The novel optical properties of bismuthine that are easily manipulated by electric fields may find a lot of various applications in optoelectronics, either combined with or complementary to those graphene-based systems.

A New Strategy for Obesity Treatment: Revealing the Frontiers of Anti-obesity Medications.

Obesity dramatically increases the risk of type 2 diabetes, fatty liver, hypertension, cardiovascular disease, and cancer, causing both declines in quality of life and life expectancy, which is a serious worldwide epidemic. At present, more and more patients with obesity are choosing drug therapy. However, given the high failure rate, high cost, and long design and testing process for discovering and developing new anti-obesity drugs, drug repurposing could be an innovative method and opportunity to broaden and improve pharmacological tools in this context. Because different diseases share molecular pathways and targets in the cells, anti-obesity drugs discovered in other fields are a viable option for treating obesity. Recently, some drugs initially developed for other diseases, such as treating diabetes, tumors, depression, alcoholism, erectile dysfunction, and Parkinson's disease, have been found to exert potential anti-obesity effects, which provides another treatment prospect. In this review, we will discuss the potential benefits and barriers associated with these drugs being used as obesity medications by focusing on their mechanisms of action when treating obesity. This could be a viable strategy for treating obesity as a significant advance in human health.

Feeding-induced hepatokines and crosstalk with multi-organ: A novel therapeutic target for Type 2 diabetes.

Hyperglycemia, which can be caused by either an insulin deficit and/or insulin resistance, is the main symptom of Type 2 diabetes, a significant endocrine metabolic illness. Conventional medications, including insulin and oral antidiabetic medicines, can alleviate the signs of diabetes but cannot restore insulin release in a physiologically normal amount. The liver detects and reacts to shifts in the nutritional condition that occur under a wide variety of metabolic situations, making it an essential organ for maintaining energy homeostasis. It also performs a crucial function in glucolipid metabolism through the secretion of hepatokines. Emerging research shows that feeding induces hepatokines release, which regulates glucose and lipid metabolism. Notably, these feeding-induced hepatokines act on multiple organs to regulate glucolipotoxicity and thus influence the development of T2DM. In this review, we focus on describing how feeding-induced cross-talk between hepatokines, including Adropin, Manf, Leap2 and Pcsk9, and metabolic organs (e.g.brain, heart, pancreas, and adipose tissue) affects metabolic disorders, thus revealing a novel approach for both controlling and managing of Type 2 diabetes as a promising medication.

Landau subband and Landau level properties of AA-stacked graphene superlattice.

Magneto-electronic properties of AA-stacked graphene superlattice (simple hexagonal graphite) are studied by the tight-binding model with an exact diagonalization method. The Landau subbands (LSs) with strong energy dispersions exist along k(z) and each subband possesses two band-edge states. Density of states reflects main features of the LSs, such as asymmetric prominent peak structures and the semimetallic behavior. Under the AA-stacked configuration, the LS wave functions are characterized by two sublattices, a and b. The quantum number (n(c,v)) of each LS, which corresponds to the number of zero points in the dominating carrier distributions, is determined by a certain sublattice and independent of k(z). For each LS, the difference between the number of zero point of the a and b sublattices is fixed and equals one. Furthermore, a reliable approximate solution of the low-lying LS energy is obtained. Through observing this solution, the dependence of the LS energy on the field strength and quantum number, k(z)-dependent energy spacing between two LSs, and the values of atomic hopping integrals are reasonably determined. A comparison of the AA-stacked graphene superlattice and monolayer graphene demonstrates that they possess some similar magneto-electronic properties.

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In order to solve the problem that soil soluble phosphorus content in most cultivated land in China is insufficient and the plant growth is inhibited, a phosphate solubilizing microorganism (PB) was screened and identified, and its phosphate solubilizing performance was optimized. The results showed that the PB strain was belonged to Burkholderia stabilis. It had the ability of nitrogen fixation and indole-3-acetic acid (IAA) secretion, as well as a certain inhibitory effect on Escherichia coli. It could maintain high activity and phosphorus solubilizing ability at pH 8.0-10.0, indicating good alkali resistance. The results of phosphorus dissolving performance optimization showed that the phosphate solubilizing capacity of strain PB reached the best at 30℃, pH 7.0, 180 r·min-1, using glucose as carbon source, ammonium sulfate as nitrogen source, tricalcium phosphate as phosphorus source and adding 50 µmol·L-1 lysine. The amount of dissolved phosphorus was 569.33 mg·L-1, which was 1.9 times of that before optimization. The strain mainly secreted citric acid, malonic acid, and glucuronic acid during metabolism. After adding lysine, the type of organic acids secreted by the strain did not change, but the content increased significantly. Results from pot experiments showed that the application of PB bacterial fertilizer could significantly improve the growth and physiological indicators of garlic seedlings, and that the promotion effect was more obvious after adding lysine. Compared with the control, the height of seedling was increased by 18.6%, seedling diameter was increased by 16.7%, aboveground fresh and dry weight were increased by 22.1% and 15.7%, and belowground fresh and dry weight were increased by 22.0% and 28.7%, respectively in PB with lysine treatment. Soil available phosphorus content was 2.1 and 2.3 times of the control in PB and PB+lysine treatments, indicating that PB could improve soil available phosphate content. Adding lysine could strengthen such function.

Low-energy Landau level spectrum in ABC-stacked trilayer graphene.

The low-lying Landau level (LL) properties of ABC-stacked trilayer graphene are investigated by the tight-binding (TB) model. The LL spectra exhibit an asymmetric structure around the Fermi level and three finely split LLs close to the Fermi level. The LL wave functions are described by six magnetic TB Bloch functions associated with six sublattices. These Bloch functions possess oscillation modes and localization features. An effective quantum number, which is used to define a LL, is defined by the oscillation mode of the Bloch function with the largest amplitude. The LL energies in the low-field and high-field regions exhibit different features since the trigonal warping effect strongly dominates the LL properties in the low-field region. Furthermore, the LLs do not present a simple relation between the magnetic field strength (effective quantum number) and the LL energy. A detailed comparison of the calculation with all atomic interactions taken into account and that ignoring some interlayer interactions is offered. The dissimilarities between these two calculations demonstrate that interlayer interactions strongly affect the main features of LLs and should not be ignored. The dissimilarities could be further examined by experimental measurements.

Potential mechanism of Ziyin Tongluo Formula in the treatment of postmenopausal osteoporosis: based on network pharmacology and ovariectomized rat model.

BACKGROUND: Amending from ancient classic, Ziyin Tongluo Formula (ZYTLF) has been prescribed to treat postmenopausal osteoporosis (PMOP) for decades with good curative effect. However, the possible mechanisms of it are still unknown. METHODS: Ovariectomized rat model was established to validate the therapeutic effect of ZYTLF on PMOP by Micro-CT bone analysis and pathological observation. Subsequently, active ingredients of ZYTLF and corresponding putative targets were identified by online databases. Overlapping genes were first obtained from mining genes associated with PMOP and then overlapped them with the putative targets. Key genes were selected from the multiple constructed and analyzed networks. GO and KEGG pathway enrichment analysis were performed by importing the key genes to the DAVID database. Moreover, validation of the binding association between key targets and their corresponding active compounds were accomplished by AutoDock Tools and other software. Lastly, Enzyme linked immunosorbent assay (Elisa) detection and Western blot analysis were utilized to further explore the possible mechanism of ZYTLF on PMOP. RESULTS: With 129 target genes interacting with PMOP, 92 active compounds of ZYTLF corresponded to 243 targets, and 50 key genes were chosen. Network analysis revealed the top 10 active ingredients, such as quercetin and kaempferol and the top 50 key genes, such as ERα, p38 MAPK, p-AKT and TGF-ß1. Enrichment analysis uncovered multiple signaling pathways, including estrogen signaling pathway, TNF signaling pathway, PI3K-Akt signaling pathway and MAPK signaling pathway. Furthermore, our finding of the foremost active compounds was tightly bound to the core proteins, which were verified by molecular docking analysis. Through experimental studies, we confirmed that the prescription of ZYTLF could ameliorate the OVX-induced bone loss, suppress the osteoclast activity and boost osteoblast ability through experimental studies. CONCLUSION: The potential mechanisms and therapeutic effects of ZYTLF against PMOP may be ascribed to inhibition of osteoclast activity, boost of osteoblast activity and enhancement of the expression of ERα.

Optical absorption spectra in finite double-walled carbon nanotubes.

The tight-binding model and the modified gradient approximation are, respectively, used to calculate the electronic states and optical properties of finite double-walled carbon nanotubes (DWCNTs). The optical absorption spectra allow us to decompose the total DWCNT spectral function into the contributions from the inner and outer walls. Intertube interactions can cause drastic changes in the symmetry of the electronic states, the Fermi level, the energy spacing, and the state degeneracy. Such effects are directly reflected in the joint density of states and optical absorption spectra. Thus, the first absorption peaks of the energy degeneracy (nondegeneracy) of two finite single-walled carbon nanotubes would be separated into three or four peaks in the shorter DWCNTs. For finite armchair DWCNTs, the number of the first group peaks decreases as the length increases. These results demonstrate a competition between the tube length, the intertube interactions, and the geometric structures. For finite zigzag DWCNTs however, the number of the first group peaks remains constant as the length increases. This phenomenon can be attributed to the states exclusively localized at the outermost zigzag positions. The energies of the peaks make a red-shift as the tube length increases. For sufficiently long DWCNTs absorption peak energies are almost independent of length.

Prediction of Quantum Anomalous Hall Effect in MBi and MSb (M:Ti, Zr, and Hf) Honeycombs.

The abounding possibilities of discovering novel materials has driven enhanced research effort in the field of materials physics. Only recently, the quantum anomalous hall effect (QAHE) was realized in magnetic topological insulators (TIs) albeit existing at extremely low temperatures. Here, we predict that MPn (M =Ti, Zr, and Hf; Pn =Sb and Bi) honeycombs are capable of possessing QAH insulating phases based on first-principles electronic structure calculations. We found that HfBi, HfSb, TiBi, and TiSb honeycomb systems possess QAHE with the largest band gap of 15 meV under the effect of tensile strain. In low-buckled HfBi honeycomb, we demonstrated the change of Chern number with increasing lattice constant. The band crossings occurred at low symmetry points. We also found that by varying the buckling distance we can induce a phase transition such that the band crossing between two Hf d-orbitals occurs along high-symmetry point K2. Moreover, edge states are demonstrated in buckled HfBi zigzag nanoribbons. This study contributes additional novel materials to the current pool of predicted QAH insulators which have promising applications in spintronics.

Optical properties of monolayer tinene in electric fields.

The absorption spectra of monolayer tinene in perpendicular electric fields are studied by the tight-binding model. There are three kinds of special structures, namely shoulders, logarithmical symmetric peaks and asymmetric peaks in the square-root form, corresponding to the optical excitations of the extreme points, saddle points and constant-energy loops. With the increasing field strength, two splitting shoulder structures, which are dominated by the parabolic bands of 5p z orbitals, come to exist because of the spin-split energy bands. The frequency of threshold shoulder declines to zero and then linearly grows. The third shoulder at 0.75~0.85 eV mainly comes from (5p x , 5p y ) orbitals. The former and the latter orbitals, respectively, create the saddle-point symmetric peaks near the M point, while they hybridize with one another to generate the loop-related asymmetric peaks. Tinene quite differs from graphene, silicene, and germanene. The special relationship among the multi-orbital chemical bondings, spin-orbital couplings and Coulomb potentials accounts for the feature-rich optical properties.