[Research progress in Filifactor alocis interacting with periodontitis].

Many new microbial species which are correlated with periodontitis have been identified in addition to the"red complex"cultured by conventional methods due to the development of high-throughput sequencing technology. Filifactor alocis (Fa), as a anaerobic Gram-positive bacteria, is closely related to the occurrence and development of periodontitis. Fa can not only destroy host cells and induce immune escape response, but also interact with other periodontal pathogens to promote the periodontitis. This article summarizes and discusses the research progress on the relationship between Fa and periodontitis in recent years and highlighs a new way to investigate the etiology, prevention and treatment of periodontitis.

Vitamin D deficiency in patients with stages 1 and 2 chronic kidney disease in Southern China.

AIM: We aim to investigate the incidence and associated factors of vitamin D deficiency, a seldom reported factor, in patients with stages 1 and 2 chronic kidney disease (CKD) in southern China. METHODS: We conducted a single-center observational study. Hospitalized patients over 14 years old, who were diagnosed with stages 1 and 2 CKD and had their serum 25-hydroxyvitamin D [25 (OH) D] measured, were included. Patients were divided into vitamin D deficient and non-deficient groups depending on the cutoff serum 25 (OH) D value of 37 nmol/L. Clinical and biochemical parameters were evaluated for associated factors of vitamin D deficiency by logistic regression. RESULTS: A total of 118 patients were included, of which 62 (52.5%) were vitamin D insufficient and 47 (39.8%) were vitamin D deficient. Using multivariate binary logistic regression analysis, high serum level of gamma-glutamyl transpeptidase (GGT) (OR = 5.163; 95%CI, 1.105-24.130; P = 0.037), dyslipidemia (OR = 3.083; 95%CI, 1.029-9.243; P = 0.044), 24-hour urinary protein excretion (UPE) ≥3.5 g/24 hrs (OR = 5.010; 95%CI, 1.316-19.074; P = 0.018), and treatment with glucocorticoids (OR = 2.973; 95%CI, 1.093-8.084; P = 0.033) were independently associated with vitamin D deficiency. In addition, among different types of nephropathy, minimal change disease (MCD) had the highest incidence (85.7%) of vitamin D deficiency. CONCLUSION: Poor vitamin D status is common in patients with stages 1 and 2 CKD in southern China. The incidence of vitamin D deficiency is 39.8%. High serum GGT level, dyslipidemia, 24-hour UPE ≥3.5 g/24 hrs, and treatment with glucocorticoids are independent associated factors of vitamin D deficiency.

Predictors of Vitamin D deficiency in predialysis patients with stage 3-5 chronic kidney diseases in Southern China.

OBJECTIVE: Vitamin D status and risk factors of Vitamin D deficiency in chronic kidney disease (CKD) patients in China have been seldom reported before. In this study, we aim to investigate serum 25-hydroxyvitamin D [25(OH)D] status and find the predictors of Vitamin D deficiency in predialysis patients with Stage 3-5 CKDs in Southern China. METHODS: In this retrospective cross-sectional study, hospitalized predialysis patients who were diagnosed of Stage 3-5 CKD and had taken measurement of serum 25(OH)D in a single center from January 2014 to June 2015 were included. Patients were divided into Vitamin D deficiency group and nondeficiency group depending on the cutoff serum 25(OH)D value of 37 nmol/L. Clinical and biochemical parameters were collected and evaluated for predictors of Vitamin D deficiency by logistic regression. RESULTS: One hundred and fifty-two patients were included in this study, of which 87 (57.2%) were in Vitamin D insufficiency state while 60 (39.5%) were in Vitamin D deficiency state. Serum 25(OH)D levels of patients in Stage 4 and Stage 5 CKD were lower than that of patients in Stage 3 CKD (P = 0.002). It was discovered that female gender (odds ratio [OR] = 3.674; 95% confidence interval [CI], 1.607-8.396; P = 0.002), serum albumin level <30.0 g/L (OR = 6.816; 95% CI, 2.634-17.633; P < 0.001), and estimated glomerular filtration rate (eGFR) <30 ml/min/1.73 m2 (OR = 4.761; 95% CI, 1.353-16.754; P = 0.015) were independent predictors of Vitamin D deficiency. CONCLUSIONS: Vitamin D insufficiency and deficiency are common in predialysis patients with Stage 3-5 CKD in Southern China. Female gender, hypoalbuminemia with serum albumin level <30.0 g/L, and severe damaged renal function with eGFR <30 ml/min/1.73 m2 are independent predictors of Vitamin D deficiency in predialysis patients with Stage 3-5 CKD.

Hidden Antipolar Order Parameter and Entangled Néel-Type Charged Domain Walls in Hybrid Improper Ferroelectrics.

Hybrid improper ferroelectricity (HIF) denotes a new class of polar instability by the mixture of two octahedral-distortion modes and can feature the coexistence of abundant head-to-head and tail-to-tail polar domains, of which the domain walls tend to be charged due to the respective screening charges with an opposite sign. However, no such coexisting carriers are available in the materials. Using group-theoretical, microscopic, and spectroscopic analyses, we establish the existence of a hidden antipolar order parameter in model HIF (Ca,Sr)_{3}Ti_{2}O_{7} by the condensation of a weak, previously unnoticed antipolar lattice instability, turning the order-parameter spaces to be multicomponent with the distinct polar-antipolar intertwining and accompanied formation of Néel-type twinlike antipolar domain walls (few nanometers) between the head-to-head and tail-to-tail domains. The finite-width Néel walls and correlated domain topology inherently lift the polar divergences between the domains, casting an emergent exemplification of charged domain-wall screening by an antipolar ingredient.

Domain topology and domain switching kinetics in a hybrid improper ferroelectric.

Charged polar interfaces such as charged ferroelectric walls or heterostructured interfaces of ZnO/(Zn,Mg)O and LaAlO3/SrTiO3, across which the normal component of electric polarization changes suddenly, can host large two-dimensional conduction. Charged ferroelectric walls, which are energetically unfavourable in general, were found to be mysteriously abundant in hybrid improper ferroelectric (Ca,Sr)3Ti2O7 crystals. From the exploration of antiphase boundaries in bilayer-perovskites, here we discover that each of four polarization-direction states is degenerate with two antiphase domains, and these eight structural variants form a Z4 × Z2 domain structure with Z3 vortices and five distinct types of domain walls, whose topology is directly relevant to the presence of abundant charged walls. We also discover a zipper-like nature of antiphase boundaries, which are the reversible creation/annihilation centres of pairs of two types of ferroelectric walls (and also Z3-vortex pairs) in 90° and 180° polarization switching. Our results demonstrate the unexpectedly rich nature of hybrid improper ferroelectricity.

Large single crystal growth, transport property, and spectroscopic characterizations of three-dimensional Dirac semimetal Cd3As2.

The three dimensional (3D) Dirac semimetal is a new quantum state of matter that has attracted much attention recently in physics and material science. Here, we report on the growth of large plate-like single crystals of Cd3As2 in two major orientations by a self-selecting vapor growth (SSVG) method, and the optimum growth conditions have been experimentally determined. The crystalline imperfections and electrical properties of the crystals were examined with transmission electron microscopy (TEM), scanning tunneling microscopy (STM), and transport property measurements. This SSVG method makes it possible to control the as-grown crystal compositions with excess Cd or As leading to mobilities near 5-10(5) cm(2)V(-1)s(-1). Zn-doping can effectively reduce the carrier density to reach the maximum residual resistivity ratio (RRRρ300K/ρ5K) of 7.6. A vacuum-cleaved single crystal has been investigated using angle-resolved photoemission spectroscopy (ARPES) to reveal a single Dirac cone near the center of the surface Brillouin zone with a binding energy of approximately 200 meV.

Scanning transmission electron microscopy using selective high-order laue zones: three-dimensional atomic ordering in sodium cobaltate.

A new scanning transmission electron microscopy (STEM) imaging technique using high-order Laue zones (named HOLZ-STEM), a diffraction contrast which has been strenuously avoided or minimized in traditional STEM imaging, can be used to obtain the additional 1D periodic information along the electron propagation axis without sacrificing atomic resolution in the lateral (2D) dimension. HOLZ-STEM has been demonstrated to resolve the 3D long-range Na ordering of Na0.71CoO2. Direct evidence of spiral-like Na-trimer chains twisting along the c axis is unambiguously established in real space.

Sodium ion ordering and vacancy cluster formation in NaxCoO2 (x=0.71 and 0.84) single crystals by synchrotron X-Ray diffraction.

In the rich phase diagram of NaxCoO2, x=0.71 enjoys special stability and is called the Curie-Weiss metal due to its anomalous properties. Similarly, x=0.84 prepared from high temperature melt is a special end point beyond which the system phase separates. Using synchrotron x-ray diffraction on single crystals, we discovered sqrt[12]a and sqrt[13]a superlattice structures which we interpret as the ordering of Na (vacancy) clusters. These results lead to a picture of coexisting local moments and itinerant carriers and form the first step towards understanding the many anomalous properties of cobaltates.