Ground state and edge excitations of quantum Hall liquid at filling factor 2/3

We present a numerical study of fractional quantum Hall liquid at Landau level filling factor $\nu=2/3$ in a microscopic model including long-range Coulomb interaction and edge confining potential, based on the disc geometry. We find the ground state is accurately described by the particle-hole conjugate of a $\nu=1/3$ Laughlin state. We also find there are two counter-propagating edge modes, and the velocity of the forward-propagating mode is larger than the backward-propagating mode. The velocities have opposite responses to the change of the background confinement potential. On the other hand changing the two-body Coulomb potential has qualitatively the same effect on the velocities; for example we find increasing layer thickness (which softens of the Coulomb interaction) reduces both the forward mode and the backward mode velocities.Comment: 12 pages, 13 figure

Quasiparticle tunneling in the Moore-Read fractional quantum Hall State

In fractional quantum Hall systems, quasiparticles of fractional charge can tunnel between the edges at a quantum point contact. Such tunneling (or backscattering) processes contribute to charge transport, and provide information on both the charge and statistics of the quasiparticles involved. Here we study quasiparticle tunneling in the Moore-Read state, in which quasiparticles of charge e/4 (non-Abelian) and e/2 (Abelian) may co-exist and both contribute to edge transport. On a disk geometry, we calculate the matrix elements for e/2 and e/4 quasiholes to tunnel through the bulk of the Moore-Read state, in an attempt to understand their relative importance. We find the tunneling amplitude for charge e/2 quasihole is exponentially smaller than that for charge e/4 quasihole, and the ratio between them can be (partially) attributed to their charge difference. We find that including long-range Coulomb interaction only has a weak effect on the ratio. We discuss briefly the relevance of these results to recent tunneling and interferometry experiments at filling factor nu=5/2.Comment: 9 pages, 6 figures; v2: expanded to include 3 more figures, minor corrections, references update

(2-Pyrid­yl)[5-(2-pyridyl­carbon­yl)-2-pyrid­yl]methanone

In the centrosymmetric title compound, C17H11N3O2, the dihedral angle between the central and pendant pyridyl rings is 50.29 (9)°. In the crystal, mol­ecules stack along the a axis by π–π inter­actions between the pyridine rings with centroid–centroid distances of 3.845 (2) Å. The N atom and one of the C atoms of the central ring are disordered by symmetry

Physical Exercise-Related Manifestations of Long COVID: A Systematic Review and Meta-Analysis

OBJECTIVE: This study aims to systematically assess physical exercise-related symptoms of post-acute sequelae of SARS-CoV-2 infection (PASC or long COVID) in coronavirus disease 2019 (COVID-19) survivors. METHODS: Eight databases were systematically searched on March 03, 2024. Original studies that compared physical exercise-related parameters measured by exercise testing between COVID-19 survivors who recovered from SARS-CoV-2 infection over 3 months and non-COVID-19 controls were included. A random-effects model was utilized to determine the mean differences (MDs) or standardized MDs in the meta-analysis. RESULTS: A total of 40 studies with 6241 COVID-19 survivors were included. The 6-min walk test, maximal oxygen consumption (VO CONCLUSION: The findings suggest an underestimation of the manifestations of PASC. COVID-19 survivors also harbor physical exercise-related symptoms of PASC that can be determined by the exercise testing and are distinct from those observed at rest. Exercise testing should be included while evaluating the symptoms of PASC in COVID-19 survivors

(Z)-Isobutyl 2-benzamido-3-(4-chloro­phen­yl)acrylate

The title compound, C20H20ClNO3, is a α-amino acid derivative which displays a Z configuration about the C=C double bond. The dihedral angle betwen the aromatic rings is 87.75 (12)°. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯N hydrogen bond. In the crystal structure, centrosymmetrically related mol­ecules inter­act through inter­molecular C—H⋯O hydrogen-bond inter­actions, forming dimers. The dimers are further linked into chains parallel to the a axis by N—H⋯O hydrogen bonds. The methyl groups of the isopropyl group are disordered over two positions with occupancy factors of 0.5

Effect of ligustrazine injection on the change of oxidative stress system during renal ischemia reperfusion injury in rabbits

目的  通过由兔肾脏缺血/再灌注损伤（IRI）导致的氧化应激体系中的变化，研究中药川芎嗪对IRI干预下的作用机制。方法  建立持续性阻断兔双侧肾动脉血流1h，再灌注5h的肾IRI动物模型。日本大耳兔32只，随机分成3组（n=10）：假手术组(sham，S组)，缺血/再灌注组(ischemia-reperfusion，IR组)，川芎嗪干预缺血/再灌注组（ligustrazine+ ischemia-reperfusion，LZ组），另外两只作为补充实验中意外死亡之用。于缺血前、缺血1h、再灌注1h、3h和5h依次经颈总动脉抽血用以检测超氧化物歧化酶（SOD）活力、黄嘌呤氧化酶（XO）活力以及丙二醛（MDA）含量。在实验结束后取兔肾组织依次检测SOD、XO活力以及MDA含量，并对其进行电镜观察。结果  随着肾缺血和再灌注时间的增加，IR组和LZ组血浆中的XO活力和MDA含量逐渐呈上升趋势，但同时间点LZ组较于IR组明显降低（均P<0.01）；SOD活力随着肾缺血和再灌注时间的增加而逐渐呈下降趋势，但同时间点下，LZ组较于IR组均明显偏高（均P<0.01）。IR组和LZ组相较于S组，肾组织XO活力、MDA含量均明显升高，SOD活力均明显降低（均P<0.01）；而LZ组肾组织中的XO活力、MDA含量均显著低于IR组，SOD活力均显著高于IR组，差异有非常显著性（均P<0.01），LZ组肾组织细胞的超微结构异常改变较IR组显著减轻。结论  川芎嗪能够使氧自由基水平降低，氧化应激损伤减轻，具有保护肾缺血/再灌注损伤的作用。Objective: To investigate the change of oxidative stress system during renal ischemia-reperfusion injury, and to study the mechanism of Ligustrazine on IRI under the intervention. Methods: Establish the IRI animal model by persistent blocking rabbits’ bilateral renal artery blood flow for 1 hour, then reperfusion for another 5 hours. Japanese big ear rabbits, 32, were randomly divided into three groups (n=10): sham operation group (group S), ischemia/reperfusion group (group IR), the effect of ligustrazine on ischemia/ reperfusion group (LZ group), the other two being added in the experiment for accidental death. In 1 hour before ischemia, ischemia, reperfusion 1h, 3h and 5h in turn to check the enzyme activity of superoxide dismutase (SOD), xanthine oxidase (XO) and the content of malondialdehyde (MDA) by getting the blood from common carotid artery. At the end of the experiment, the rabbit’s kidney was used to check the enzyme activity of XO, SOD and the content of MDA, then to observe the morphological changes under the electron microscopy. Results: With the increase of renal ischemia and reperfusion time, XO activity and MDA content of IR group and LZ group in plasma gradually up, they were significantly lower in LZ group than in IR group at same time point (all P<0.01), the activity of SOD in plasma was shown a time-dependent decline in both IR group and LZ group, whereas it was significant higher in LZ group compared with IR group at same time point during ischemia reperfusion (all P<0.01). SOD activity gradually decreased with the increase of renal ischemia and reperfusion time, but at the same time point, LZ group compared with IR group were significantly higher (P<0.01), however, for LZ group, as compared with IR group, activity of XO, content of MDA were increased remarkably while activity of SOD was decreased significantly in kidney tissue (all P<0.01) the abnormal changes of ultrastructure were mitigated significantly. Conclusion: Ligustrazine may attenuate renal ischemia-reperfusion injury by dropping oxygen free radical generation and enhancing oxygen free radical scavenge so that it can antagonize oxidative stress

A system-level mechanistic investigation of traditional Chinese medicine, Yinlai Decoction, for related diseases

Purpose: To systemically explore the pharmacological mechanisms of traditional Chinese medicine, Yinlai Decoction (YD), used in the clinical management of pediatric diseases such as pneumonia and recurrent respiratory tract infections.Methods: An ingredient-target-disease database of YD was constructed using Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). First, the molecular targets related to lung and stomach diseases were searched and screened to avoid duplication. Second, the associations between these molecular targets were evaluated via Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and Gene Ontology (GO) and Pathway enrichment analysis in STRING.Results: A total of 627 chemical ingredients and 654 protein targets in YD were obtained. After further screening, 38 molecular targets linked to respiratory diseases, inflammatory responses and various infections were identified. Finally, 576 GO terms and 75 KEGG pathway terms were obtained by analyzing gene functional annotation clusters and abundance value of these targets. Most of these terms were closely related to the inflammatory response.Conclusion: Based on these in silico findings, the use of YD for treating respiratory diseases, inflammation and various infections, most probably via the suppression of inflammation, has been established. The approach adopted in this study can serve as a model methodology to develop an innovative TCM candidate drug at a network pharmacology level.Keywords: Yinlai Decoction, Network (System) pharmacology, Inflammation, Interacting genes/proteins, Gene ocntology, Pathway enrichment analysi

Symmetry-breaking-induced giant Stark effect in 2D Janus materials

Symmetry breaking generally induce exotic physical properties, particularly for low-dimensional materials. Herein we demonstrate that symmetry breaking induces a giant Stark effect in 2D Janus materials using group IV-V monolayers with a four-atom-layer structure as a model system, which are constructed by Ge and As element substitution of symmetrical SnSb monolayer. A linear giant Stark effect is found in Janus semiconductor monolayers, as verified by the band gap variation up to 134 meV of Sn2SbAs monolayer, which is 30 times larger than that of SnSb monolayer (4 meV) when the applied electric field is increased from -0.30 to 0.30 V/{\AA}. By considering the induced electronic field, we propose a generalized and effective formula that efficiently determines the band gap variation owing to Stark effect. The calculated results from proposed formula are well agreement with those from DFT-HSE06 functional. The giant Stark effect is originated from the large spatial separation of centers of the conduction band minimum and valence band maximum states of Janus structure due to its intrinsic potential gradient. The wide-range tuning of band gap under electronic field shows potential applications of 2D Janus materials in optoelectronic devices.Comment: 10 pages, 5 figure

Identification and Functional Analysis of Variant Haplotypes in the 5′-Flanking Region of Protein Phosphatase 2A-Bδ Gene

Serine-threonine protein phosphatase 2A (PP2A) is a trimeric holoenzyme that plays an integral role in the regulation of cell growth, differentiation, and apoptosis. The substrate specificity and (sub)cellular localization of the PP2A holoenzymes are highly regulated by interaction with a family of regulatory B subunits (PP2A-Bs). The regulatory subunit PP2A-B/PR55δ (PP2A-Bδ) is involving in the dephosphorylation of PP2A substrates and is crucial for controlling entry into and exit from mitosis. The molecular mechanisms involved in the regulation of expression of PP2A-Bδ gene (PPP2R2D) remain largely unknown. To explore genetic variations in the 5′-flanking region of PPP2R2D gene as well as their frequent haplotypes in the Han Chinese population and determine whether such variations have an impact on transcriptional activity, DNA samples were collected from 70 healthy Chinese donors and sequenced for identifying genetic variants in the 5′-flanking region of PPP2R2D. Four genetic variants were identified in the 1836 bp 5′-flanking region of PPP2R2D. Linkage disequilibrium (LD) patterns and haplotype profiles were constructed for the genetic variants. Using serially truncated human PPP2R2D promoter luciferase constructs, we found that a 601 bp (−540 nt to +61 nt) fragment constitutes the core promoter region. The subcloning of individual 5′-flanking fragment revealed the existence of three haplotypes in the distal promoter of PPP2R2D. The luciferase reporter assay showed that different haplotypes exhibited distinct promoter activities. The EMSA revealed that the −462 G>A variant influences DNA-protein interactions involving the nuclear factor 1 (NF1). In vitro reporter gene assay indicated that cotransfection of NF1/B expression plasmid could positively regulate the activity of PPP2R2D proximal promoter. Introduction of exogenous NF1/B expression plasmid further confirmed that the NF1 involves in the regulation of PPP2R2D gene expression. Our findings suggest that functional genetic variants and their haplotypes in the 5′-flanking region of PPP2R2D are critical for transcriptional regulation of PP2A-Bδ