Black P/graphene hybrid: A fast response humidity sensor with good reversibility and stability.

Black phosphorus (BP) materials have attracted considerable attention owing to their ultra-sensitive humidity sensing characteristics because of the natural absorption of water (H2O) molecules on the BP surface caused by the specific 2D layer-crystalline structure. On the other hand, the BP-based humidity sensor is less repeatable due to the instability of BP with water molecules and the stability of the sensor is reduced. In this study, this limitation of the BP-based humidity sensor was overcome by preparing a BP/graphene hybrid as a novel humidity sensing nanostructure. The BP/graphene interface improved the stability of the humidity sensor after a few weeks with a linear response within the relative humidity (RH) range of 15-70%. The sensor's response/recovery speed of the humidity sensor was extremely fast within few seconds. The response (S) of the humidity sensor based on the BP/graphene hybrid is 43.4% at RH = 70%. The estimated response and recovery time of the sensor is only 9 and 30 seconds at RH = 70% at room temperature. The experimental investigation reveals that the BP/graphene hybrid not only improves the reversibility and hysteresis factors but also enhances the stability of the humidity sensor.

Cubic Crystal-Structured SnTe for Superior Li- and Na-Ion Battery Anodes.

A cubic crystal-structured Sn-based compound, SnTe, was easily synthesized using a solid-state synthetic process to produce a better rechargeable battery, and its possible application as a Sn-based high-capacity anode material for Li-ion batteries (LIBs) and Na-ion batteries (NIBs) was investigated. The electrochemically driven phase change mechanisms of the SnTe electrodes during Li and Na insertion/extraction were thoroughly examined utilizing various ex situ analytical techniques. During Li insertion, SnTe was converted to Li4.25Sn and Li2Te; meanwhile, during Na insertion, SnTe experienced a sequential topotactic transition to NaxSnTe (x ≤ 1.5) and conversion to Na3.75Sn and Na2Te, which recombined into the original SnTe phase after full Li and Na extraction. The distinctive phase change mechanisms provided remarkable electrochemical Li- and Na-ion storage performances, such as large reversible capacities with high Coulombic efficiencies and stable cyclabilities with fast C-rate characteristics, by preparing amorphous-C-decorated nanostructured SnTe-based composites. Therefore, SnTe, with its interesting phase change mechanisms, will be a promising alternative for the oncoming generation of anode materials for LIBs and NIBs.

Associations between genetic variants in the IRGM gene and inflammatory bowel diseases in the Korean population.

BACKGROUND: Recent European ancestry genome-wide association studies have identified genetic variants of IRGM as significant susceptibility loci for Crohn's disease (CD). Therefore, we investigated whether genetic variants of IRGM confer genetic susceptibility to CD or ulcerative colitis (UC) and evaluated the genotype-phenotype associations in the Korean population. METHODS: This study included 510 inflammatory bowel disease (IBD) patients (253 patients with CD and 257 with UC) and 520 healthy controls in Koreans. Initially, we performed direct sequencing analysis to identify unique IRGM single nucleotide polymorphisms (SNPs). Three selected haplotype-tagging SNPs and one risk locus (rs72553867, rs10065172, rs4958847, and rs12654043) within the IRGM were then geno-typed in patients and controls. RESULTS: IRGM SNP rs10065172 was significantly associated with CD susceptibility in terms of allelic frequency (P = 0.004; odds ratio [OR] = 1.42) and genotype frequency (dominant model, P = 0.008; OR = 1.62). We also found a relationship between SNP rs72553867 and CD susceptibility in the analysis of allelic frequency (P = 0.0117; OR = 0.67) and genotype frequency (dominant model, P = 0.002; OR = 0.55). In addition, we observed that the association of CD with rs10065172 became stronger in patients with younger age at diagnosis (≤ 20 years) or male gender. However, there was no significant association between the four SNPs and UC susceptibility. CONCLUSIONS: This is the first study to identify SNP rs10065172 and rs72553867 in IRGM as principal CD susceptibility loci in an Asian population.

Association of CYP2C19*2 and *3 genetic variants with essential hypertension in Koreans.

PURPOSE: The cytochrome P450 2C19 (CYP2C19) metabolizes arachidonic acid to produce epoxyicosanoid acids, which are involved in vascular tone and regulation of blood pressure. Recent findings suggest that CYP2C19 gene might be considered as a novel candidate gene for treatment of cardiovascular disease. The aim of the present study was to evaluate the association between two variants, CYP2C19* 2 (681G>A) and CYP2C19*3 (636G>A) and the development of essential hypertension (EH) in Koreans. MATERIALS AND METHODS: We carried out an association study in a total of 1190 individuals (527 hypertensive subjects and 663 unrelated healthy controls). The CYP2C19 polymorphisms were genotyped using the SNaPShot™ assay. RESULTS: The distribution of alleles and genotypes of CYP2C19* 3 showed significant difference between hypertensive patients and normal controls (p=0.011 and p=0.013, respectively). Logistic regression analysis indicated that the CYP2C19*3 (636A) allele carriers were significantly associated with EH [odds ratio, 0.691; 95% confidence interval (CI), 0.512-0.932, p=0.016], in comparison to wild type homozygotes (CYP2C19*1/*1). Neither genotype nor allele distribution of CYP2C19*2 polymorphism showed significant differences between hypertensive and control groups (p>0.05). CONCLUSION: Our present findings strengthen the evidence of an association between CYP2C19 gene polymorphism and EH prevalence. In particular, the CYP2C19*3 defective allele may contribute to reduced risk for the development of EH.