Clinical Study on Dark Tea with Pericarpium Citri Reticulatae Combined with Metformin for Type 2 Diabetes Mellitus

[Objectives]To observe the clinical effect of dark tea with pericarpium citri reticulateae combined with metformin for type 2 diabetes mellitus.[Methods]A total of 80 cases of patients with type 2 diabetes mellitus were randomly divided into the control group and the observation group with 40 cases in each group.The control group was given metform for treatment,and the observation group was given dark tea with pericarpium citri reticulateae combined with metformin for treatment.The two groups were continuously treated for 12 weeks.The indexes of patients were observed and recorded,such as the body mass index(BMI),abdominal circumference(AC),hemoglobin A1c(HbA1c),fasting blood glucose(FBG),postprandial 2 h blood glucose(P2hBG),uric acid(UA),total cholesterol(TC),and triglyceride(TG).The incidence of adverse reactions during the treatment period and the patient satisfaction for treatment in the two groups were counted.[Results]After treatment,the FBG,P2hBG and HbA1c in the two groups were decreased when compared with those before treatment(P<0.05)and the decrease of the above indexes in the observation group was more significant than that in the control group(P<0.05).After treatment,the BMI,AC,UA,TC and TG in the observation group were decreased more significantly when compared with those before treatment and those in the control group after treatment,differences were statistically significant(P<0.05).The above indexes in the control group did not change significantly before and after treatment(P>0.05).The incidence of adverse reactions was 2.5%in the observation group and 5.0%in the control group,the difference was not statistically significant(P>0.05).The patient satisfaction was 97.5%in the observation group and 55.0%in the control group,the difference was significant(P<0.05).[Conclusions]The curative effect of dark tea with pericarpium citri reticulateae combined with metformin for type 2 diabetes mellitus is better than that of western medicine alone and has no obvious adverse reactions,thus it is worthy of clinical promotion and application.

Fermionic Analogue of High Temperature Hawking Radiation in Black Phosphorus

Time-periodic laser driving can create nonequilibrium states not accessible in equilibrium,opening new regimes in materials engineering and topological phase transitions.We report that black phosphorus(BP)exhibits spatially nonuniform topological Floquet-Dirac states under laser illumination,mimicking the"gravity"felt by fermionic quasiparticles in the same way as that for a Schwarzschild black hole(SBH).Quantum tunneling of electrons from a type-ⅡDirac cone(inside BH)to a type-ⅠDirac cone(outside BH)emits an SBH-like Planck radiation spectrum.The Hawking temperature T_H obtained for a fermionic analog of BH in the bilayer BP is approximately 3K,which is several orders of magnitude higher than that in previous works.Our work sheds light on increasing T_H from the perspective of engineering 2D materials by time-periodic light illumination.The predicted SBH-like Hawking radiation,accessible in BP thin films,provides clues to probe analogous astrophysical phenomena in solids.

Topological superconducting phase in high-T_(c) superconductor MgB_(2) with Dirac-nodal-line fermions

Topological superconductors are an intriguing and elusive quantum phase,characterized by topologically protected gapless surface/edge states residing in a bulk superconducting gap,which hosts Majorana fermions.Unfortunately,all currently known topological superconductors have a very low transition temperature,limiting experimental measurements of Majorana fermions.Here we discover the existence of a topological Dirac–nodal-line state in a well-known conventional high-temperature superconductor,MgB_(2).First-principles calculations show that the Dirac–nodal-line structure exhibits a unique one-dimensional dispersive Dirac–nodal line,protected by both spatial-inversion and time-reversal symmetry,which connects the electron and hole Dirac states.Most importantly,we show that the topological superconducting phase can be realized with a conventional s-wave superconducting gap,evidenced by the topological edge mode of the MgB_(2) thin films showing chiral edge states.Our discovery may enable the experimental measurement of Majorana fermions at high temperature.

Pressure-induced Lifshitz transition in the type Ⅱ Dirac semimetal PtTe_2

Numerous exotic properties have been discovered in Dirac Semimetals(DSMs) and Weyl Semimetals(WSMs). In a given DSM/WSM, the Dirac/Weyl nodes usually coexist with other bulk states, making their respective contribution elusive. In this work, we distinguish the role of bulk states from the tilted Dirac nodes on the transport properties in DSMs. Specifically, we applied pressure to a type-II DSM material, PtTe2, and studied its pressure modified electronic and lattice structure systematically by using in situ transport measurements and X-ray diffraction(XRD). A pressure-induced transition at about 20 GPa is revealed in the transport properties, while the layered lattice structure is robust against pressure as illustrated in XRD measurement results.Density functional theory(DFT) calculations suggest that this is originated from the Lifshitz transition in the bulk states. Our findings provide evidence to identify the bulk states' influence on transport from the topologically-protected DSM states in the DSM material.

Topological states in quasicrystals

With the rapid development of topological states in crystals, the study of topological states has been extended to quasicrystals in recent years. In this review, we summarize the recent progress of topological states in quasicrystals, particularly focusing on one-dimensional (1D) and 2D systems. We first give a brief introduction to quasicrystalline structures. Then, we discuss topological phases in 1D quasicrystals where the topological nature is attributed to the synthetic dimensions associated with the quasiperiodic order of quasicrystals. We further present the generalization of various types of crystalline topological states to 2D quasicrystals, where real-space expressions of corresponding topological invariants are introduced due to the lack of translational symmetry in quasicrystals. Finally, since quasicrystals possess forbidden symmetries in crystals such as five-fold and eight-fold rotation, we provide an overview of unique quasicrystalline symmetry-protected topological states without crystalline counterpart.

A Unified View of Topological Phase Transition in Band Theory

We develop a unified view of topological phase transitions(TPTs)in solids by revising the classical band theory with the inclusion of topology.Reevaluating the band evolution from an“atomic crystal”(a normal insulator(NI))to a solid crystal,such as a semiconductor,we demonstrate that there exists ubiquitously an intermediate phase of topological insulator(TI),whose critical transition point displays a linear scaling between electron hopping potential and average bond length,underlined by deformation-potential theory.The validity of the scaling relation is verified in various two-dimensional(2D)lattices regardless of lattice symmetry,periodicity,and form of electron hoppings,based on a generic tight-binding model.Significantly,this linear scaling is shown to set an upper bound for the degree of structural disorder to destroy the topological order in a crystalline solid,as exemplified by formation of vacancies and thermal disorder.Our work formulates a simple framework for understanding the physical nature of TPTs with significant implications in practical applications of topological materials.

LiFePO_(4)/C cathode materials synthesized by co-precipitation and microwave heating

LiFePO_(4)/C cathode materials were synthesized by a combination of co-precipitation and microwave heat-ing using polyethylene glycol(PEG)as a carbon resource and the influence of microwave heating time on the struc-ture and electrochemical performance of the materials was also discussed.The samples were characterized by X-ray diffraction(XRD),TEM,particle-size analysis and con-stant current charge-discharge experiment.The results show that the LiFePO_(4)/C heated for 9 min has a pure olive-type phase and excellent electrochemical perform-ance.The initial discharge capacities of this sample are 154.3,139.7,123.9 mAh/g at the rates 0.1C,0.2C,1C at room temperature,respectively,and after 20 cycles remain 152.3,134.3,118.5 mAh/g,respectively.

Two-dimensional Stiefel-Whitney insulators in liganded Xenes

Two-dimensional(2D)Stiefel-Whitney insulator(SWI),which is characterized by the second Stiefel-Whitney class,is a class of topological phases with zero Berry curvature.As an intriguing topological state,it has been well studied in theory but seldom realized in realistic materials.Here we propose that a large class of liganded Xenes,i.e.,hydrogenated and halogenated 2D group-IV honeycomb lattices,are 2D SWIs.The nontrivial topology of liganded Xenes is identified by the bulk topological invariant and the existence of protected corner states.Moreover,the large and tunable bandgap(up to 3.5 eV)of liganded Xenes will facilitate the experimental characterization of the 2D SWI phase.Our findings not only provide abundant realistic material candidates that are experimentally feasible but also draw more fundamental research interest towards the topological physics associated with Stiefel-Whitney class in the absence of Berry curvature.