Diverse Self-assembly Pathways in Nematic Compartment Network: Topological Percolation and Pathfinding.

The self-assembly of nematic molecules in microcompartments with unambiguously defined surface anchoring is well predictable and is likely to have a single stable topological structure. Here, in contrast, a confined nematic system comprising an array of microcompartments interconnected by channels is demonstrated, exhibiting diverse molecular assembly pathways leading to the formation of four types of topological structures and twelve different patterns randomly distributed. Intercompartment communication via channels plays a crucial role in the diversity of patterns and distributions. It determines the sizes and structures of domains separated by channel defects. The domain structure, which features a pathfinding algorithm and reverse tree structure, can be modelled by an isotropically directed bond percolation with additional restrictions. This system serves as a model for controlled randomness and restricted growth of networks, with potential applications in anticounterfeit protection as a physically unclonable function (PUF) with multiple-level communication protocols.

The efficacy and safety of tadalafil in the management of erectile dysfunction with diabetes and blood circulation issues.

BACKGROUND: Erectile dysfunction (ED) is a common diabetes-related complication. MATERIALS AND METHODS: This study examined the effect of daily low-dose tadalafil (5 mg) on patients' quality of life (including that of sex life) and blood circulation. Erectile dysfunction questionnaires were administered to 20 patients with type 2 diabetes (T2DM) and ED. The safety and efficacy of tadalafil were evaluated using laboratory tests, and the effect on blood circulation was measured through nail fold capillaroscopy. RESULTS: Daily tadalafil use by patients with T2DM and ED showed a statistically significant increase in the erectile reliability score from of 1.15 to 3.20 (p < .00012). Capillary blood circulation improvement tests showed a statistically significant increase in apical limb width from 13.1 to 14.64 µm (p = .04829) and flow from 9035 to 11946 µm3/s (p = .04405). Although not significant, increased capillary width and speed (rate of blood flow) confirmed improved blood circulation. There were no significant changes in the cardiac indicators (troponin, prostate-specific antigen, or electrocardiogram tests) before and after tadalafil administration, supporting the safety of its low-dose daily administration. CONCLUSIONS: A small dose of daily tadalafil was shown to safely improve erectile dysfunction and peripheral blood flow in patients with T2DM, in which peripheral arterial diseases should not be considered separately but rather as complex entities.

Multiresponsive Polymer Nanocomposite Liquid Crystals Having Heterogeneous Phase Transitions for Battery-Free Temperature Maintenance Indicators.

Multiresponsive functional materials that respond to more than one external stimulus are promising for novel photonic, electronic, and biomedical applications. However, the design or synthesis of new multiresponsive materials is challenging. Here, this work reports a facile method to prepare a multiresponsive colloidal material by mixing a liquid-crystalline 2D nanocolloid and a functional polymer colloid. For this purpose, electrically sensitive exfoliated α-ZrP 2D nanocolloids and thermosensitive block copolymer colloids that are dispersed well in water are mixed. In the liquid-crystalline nanocomposite, nematic, antinematic, or isotropic assemblies of α-ZrP, nanoparticles can be electrically and selectively obtained by applying electric fields with different frequencies; furthermore, their rheology is thermally and reversibly controlled through thesol-gel-sol transition. The nanocomposite exhibits a solid gel phase within a predesigned gel temperature range and a liquid sol phase outside this range. These properties facilitate the design of a simple display device in which information can be electrically written and thermally stabilized or erased, and using the device, a battery-free temperature maintenance indication function is demonstrated. The proposed polymer nanocomposite method can enrich the physical properties of 2D nanocolloidal liquid crystals and create new opportunities for eco-friendly, reusable, battery-free electro-optical devices.

Particle Filtering Based Remaining Useful Life Prediction for Electromagnetic Coil Insulation.

Electromagnetic coils are one of the key components of many systems. Their insulation failure can have severe effects on the systems in which coils are used. This paper focuses on insulation degradation monitoring and remaining useful life (RUL) prediction of electromagnetic coils. First, insulation degradation characteristics are extracted from coil high-frequency electrical parameters. Second, health indicator is defined based on insulation degradation characteristics to indicate the health degree of coil insulation. Finally, an insulation degradation model is constructed, and coil insulation RUL prediction is performed by particle filtering. Thermal accelerated degradation experiments are performed to validate the RUL prediction performance. The proposed method presents opportunities for predictive maintenance of systems that incorporate coils.

Electrical switching of birefringence in zirconium phosphate colloids with various solvents.

Even though a graphene-oxide (GO) dispersion is attractive for electro-optical switching devices because of its high Kerr coefficient, it has several limitations such as chemical instability and optical loss due to absorption at visible wavelengths. Here we introduce the use of tetrabutylammonium-tethered α-zirconium phosphate (TBA-ZrP) colloid in various solvents for electro-optical switching devices; the TBA-ZrP colloid is chemically stable and optically transparent. We find that the electrical switching behavior of TBA-ZrP is sensitively dependent on the type of solvent. The TBA-ZrP colloid in acetone exhibits the highest effective Kerr coefficient and the fastest switching time, which is related to the unusual behavior of the viscosity of the TBA-ZrP colloid in acetone. Its viscosity is relatively low and less sensitive to concentration compared to ZrP in other solvents. This indicates that the motion of individual nanoparticles is relatively less restricted in acetone. These findings may be useful in developing electro-optical devices using lyotropic liquid crystal colloids.

Comment on "Tunable Design of Structural Colors Produced by Pseudo-1D Photonic Crystals of Graphene Oxide" and Thin-Film Interference from Dried Graphene Oxide Film.

The mechanism of the iridescent color reflection from dried thin graphene oxide (GO) film on Si wafer is clarified. Dissimilarly to the photonic crystalline reflection in aqueous GO dispersion, the color reflection in dried GO film originates from the thin film interference. The peak reflection can reach 23% by optimizing the GO thickness and the substrate.

Electro-optical switching of graphene oxide liquid crystals with an extremely large Kerr coefficient.

The sensitive response of the nematic graphene oxide (GO) phase to external stimuli makes this phase attractive for extending the applicability of GO and reduced GO to solution processes and electro-optic devices. However, contrary to expectations, the alignment of nematic GO has been difficult to control through the application of electric fields or surface treatments. Here, we show that when interflake interactions are sufficiently weak, both the degree of microscopic ordering and the direction of macroscopic alignment of GO liquid crystals (LCs) can be readily controlled by applying low electric fields. We also show that the large polarizability anisotropy of GO and Onsager excluded-volume effect cooperatively give rise to Kerr coefficients that are about three orders of magnitude larger than the maximum value obtained so far in molecular LCs. The extremely large Kerr coefficient allowed us to fabricate electro-optic devices with macroscopic electrodes, as well as well-aligned, defect-free GO over wide areas.

Manipulation of structural color reflection in graphene oxide dispersions using electric fields.

Aqueous graphene oxide (GO) dispersions with a photonic crystal structure are carefully prepared to produce structural color reflection. We fabricate a simple reflective GO cell with a unique electrode design and demonstrate that the resulting structural color reflection is electrically erasable and rewritable. GO concentration and the direction of the electric field are vital factors in the development of the device. The resulting device works well, although it exhibits a rather slow response time; in particular, the spontaneous recovery time from dark to bright color reflection requires tens of minutes. Through the application of a horizontal electric field parallel to the substrate, the recovery time can be improved, resulting in a recovery period of 3 min. Although many unsolved issues remain, the findings in GO dispersion may provide a new possibility for color filter-less bi-stable color displays with low power consumption.

Optimization of particle size for high birefringence and fast switching time in electro-optical switching of graphene oxide dispersions.

In order to use graphene oxide (GO) dispersions for electro-optical applications, both a high GO concentration and a high electrical sensitivity are essential; however, these have not been achieved to date. Here, we report that by optimizing the mean size of GO particles to approximately 0.5 µm, one can obtain a high GO concentration of up to 2 wt% and high electrical sensitivity simultaneously. By reducing the mean GO-particle size, the interparticle interaction and the rotational viscosity can be significantly reduced, and a high-concentration isotropic phase can be obtained. As a result, the maximum birefringence increases and the dynamic response becomes faster. However, further decrease of the mean size below 0.1 µm causes a decrease in the anisotropy of electrical polarizability, resulting in the reduction of the electrical sensitivity of GO dispersions.

Genetic associations between miR­200bT>C and miR­495A>C polymorphisms and hypertension susceptibility.

Although microRNA (miRNA)-mediated functions and gene expression regulation are involved in the susceptibility to vascular diseases, the potential effect of miRNA polymorphisms on the susceptibility of patients to hypertension (HTN) remains to be sufficiently elucidated. Therefore, the present study aimed to identify the potential association between miRNA (miR)-200bT>C (rs7549819) and miR-495A>C (rs2281611) polymorphisms, which may be implicated in stroke and vascular pathogenesis, and the susceptibility to HTN and relevant risk factors in a Korean cohort recruited from Jeju National University Hospital (Jeju, South Korea). Using an analysis of PCR-restriction fragment length polymorphism, genotype analysis was conducted to assess the frequency of miR-200bT>C and miR-495A>C gene polymorphisms in the HTN group (n=232) and the non-HTN healthy control group (n=247). The results showed significant differences in the genotype distributions of the miR-495A>C polymorphism between the HTN and control groups, specifically with the CC genotype and C allele. However, neither the miR-200bT>C nor the dominant and recessive models were found to be distributed differently between the two groups. Following analysis of the genotype combination of the single nucleotide polymorphisms, the TC/CC and CC/CC combined genotypes of the miR-200bT>C and miR-495A>C polymorphisms were observed to be associated with susceptibility to HTN. The haplotype results demonstrated that the allele combination frequency of haplotype C-A was significantly different between the two groups. The stratified analysis revealed that the miR-200b and miR-495 polymorphisms are associated with the risk of HTN, exhibiting differences in the levels of body-mass index (<28.12 kg/m2), fasting blood glucose (<106.26 mg/dl), high-density lipoprotein cholesterol (<44.29 mg/dl) and systolic blood pressure (≥132.67 mmHg). Data from the present study suggested that the variant of miR-495A>C polymorphism and allelic combinations (haplotype C-A of miR-200bT>C/miR-495A>C) can increase hypertension susceptibility among a Korean population.

Associations of leptin receptors and miRNA polymorphisms with susceptibility to hypertension.

Leptin receptors (LEPR) are located in the central nervous system and other tissues including adipocytes and endothelial cells, where they play a key role in mediating the effects of leptin. MicroRNA (miR/miRNA)-27a and miR-155 have been shown to play an important role in the regulation of LEPR expression and are differentially expressed in various diseases. Therefore, the present study analyzed potential associations of LEPR deletion/insertion (Del/Ins), miR-27aA>G (rs895819) and miR-155T>A (rs767649) polymorphisms with a predisposition to hypertension (HTN). Genotyping was performed by a PCR-restriction fragment length polymorphism assay. Frequencies of LEPR Del/Ins and miRNA gene polymorphisms in patients diagnosed with HTN (n=232) and randomly selected healthy controls (n=247) were assessed. The present study found that Del/Ins and Ins/Ins genotypes and the Ins allele of the LEPR Del/Ins polymorphism were associated with a decreased risk of HTN compared with controls, whereas the miR-27aA>G rs895819 polymorphism was associated with an increased risk of HTN. Combined genotype and allele analyses for LEPR Del/Ins and two miRNA polymorphisms revealed an association with an increased risk or a decreased risk of HTN. Furthermore, stratification analysis revealed that HTN risk factors were associated with waist circumference (WC) and high-density lipoprotein cholesterol (HDL-C) values in LEPR Del/Ins polymorphism. They were also associated with body mass index, WC, triglyceride and HDL-C values in miR-27aA>G polymorphism. The present study revealed a combined effect of LEPR Del/Ins and miR-27aA>G polymorphisms on the risk of HTN in Koreans, suggesting that these gene polymorphisms could be potential markers for predicting HTN risk.

Genetic association between miR-27a and miR-449b polymorphisms and susceptibility to diabetes mellitus.

Various mutations in microRNAs (miRs) are associated with the pathogenesis of several diseases including cancers and vascular diseases. The present study aimed to investigate the potential association between miR-27a A>G (rs895819) and miR-449b A>G (rs10061133) polymorphisms with the prevalence of type 2 diabetes mellitus (T2DM), and its associated risk factors in the Korean population. Genotype analysis was performed using PCR-restriction fragment length polymorphism analysis to assess the frequency of miR-27a and miR-449b gene polymorphisms in patients diagnosed with T2DM (n=238) and healthy controls (n=247). The miR-27a GG genotype, recessive model, and G allele were significantly associated with a decreased risk of T2DM [adjusted odds ratio (AOR)=0.378, 95% confidence interval (CI): 0.208-0.686, P=0.001; AOR=0.425, 95% CI: 0.246-0.734, P=0.002; AOR=0.640, 95% CI: 0.493-0.831, P=0.001, respectively). Although the miR-449b polymorphism was not associated with the prevalence of T2DM, the genotype and allele combination analyses for miR-27a and miR-449b polymorphisms showed associations with T2DM prevalence. Furthermore, stratification analysis revealed that the miR-27a polymorphism was associated with DM risk factors including body mass index (<28.12 kg/m2, P=0.031), waist circumference (<93.03 cm, P=0.036), systolic blood pressure (<132.67 mmHg, P=0.017), fasting blood glucose levels (<106.26 mg/dl, P=0.015), glycosylated hemoglobin, type A1C (≤125.5 mg/dl, P=0.001), total cholesterol (≤240 mg/dl, P=0.010) and low-density lipoprotein levels (≤130 mg/dl, P=0.028). The present study revealed an association between miR-27a A>G and miR-449b A>G polymorphisms and the risk of DM in Koreans, which suggests that these gene polymorphisms could represent potential markers for predicting T2DM risk.

Association between VEGF polymorphisms and homocysteine levels in patients with ischemic stroke and silent brain infarction.

BACKGROUND AND PURPOSE: Vascular endothelial growth factor (VEGF) plays a role in atherosclerosis-related diseases such as cerebrovascular or cardiovascular diseases. However, the effect of VEGF -2578C>A, -1154G>A, -634G>C, and 936C>T polymorphisms on the susceptibility to stroke and silent brain infarction has not been reported. METHODS: Using polymerase chain reaction-amplified DNA, VEGF polymorphisms were analyzed in 615 patients with ischemic stroke, 376 patients with silent brain infarction, and 494 control subjects. RESULTS: The AA and CC+CA (C allele bearing) genotype frequencies of the -2578C>A polymorphism and the CT+TT (T allele-bearing) genotype frequency of the 936C>T polymorphism were significantly different between the stroke and control groups (false discovery rate-adjusted probability values of 0.016, 0.044, and 0.044, respectively). When stratified by the size of the occluded vessel, the VEGF polymorphisms were associated with patients with multiple small-artery occlusions. Several haplotypes of the VEGF polymorphisms were significantly different between the control and stroke groups. With respect to silent brain infarction, the difference in the frequency of the -634G>C polymorphism between the GC+CC (C allele-bearing) genotype and the controls was marginally significant (false discovery rate-adjusted probability value of 0.056). On the other hand, the -634G>C and 936C>T polymorphisms were associated with plasma homocysteine levels of patients with multiple or single small-artery occlusions, respectively. CONCLUSIONS: This study suggests that VEGF polymorphisms and haplotypes are possible genetic determinants for the risk of ischemic stroke, particularly in patients with multiple small-artery occlusions. However, VEGF polymorphisms had only a weak association with plasma homocysteine levels in the Korean population.

IFN-lambda endocytosis and IFN-lambda responsive promoter activation are dependent on cholesterol.

Recently, a relationship between receptor endocytosis and downstream signaling has been documented for several immunomodulatory molecules. However, endocytosis of interferon-lambdas (IFN-lambdas) and its impact on IFN-lambda function has not been studied. We show that IFN-lambda is internalized through a cholesterol-dependent, dynamin-independent, and Rho family of GTPase-independent pathway in HepG2 cells. Furthermore, we demonstrate that inhibition of IFN-lambda endocytosis by cholesterol depletion suppresses the activation of IFN-lambda responsive promoters. These results suggest that IFN-lambda endocytosis participates in regulating antiviral gene induction and thus may affect antiviral immunity.

Association between tumor necrosis factor-alpha (-308G→A and -238G→A) polymorphisms and homocysteine levels in patients with ischemic strokes and silent brain infarctions.

BACKGROUND AND PURPOSE: The aims of this study were to evaluate the role of tumor necrosis factor-α (TNF-α) polymorphisms in patients susceptible to ischemic stroke and silent brain infarction (SBI), and to determine the relationship between TNF-α polymorphisms and plasma total homocysteine (tHcy) levels. METHODS: We studied 237 patients with ischemic stroke, 257 patients with SBIs, and 216 control subjects. For control subjects, we selected healthy individuals matched for gender and age from those individuals who came to our hospital for health examinations. The TNF-α-308G→A and -238G→A genotypes were determined by the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: The frequency of the TNF-α-308G→A polymorphism was significantly different between the patients with ischemic stroke and the control group (GG vs. GA+AA; adjusted odds ratio, AOR, 0.50; 95% CI 0.255-0.989). By subgroup analysis, when tHcy levels were stratified into high (>10.80 µmol/l), moderate (8.21-10.80 µmol/l), and low levels (<8.21 µmol/l), the frequency of the TNF-α-308GA+AA genotype in the highest tertile group was higher than in the lowest tertile group (AOR 2.46; 95% CI 1.063-5.699). However, the relationship between SBI susceptibility and polymorphisms of TNF-α was not established. The tHcy levels were significantly and inversely correlated with folate levels in the TNF-α-308GG and TNF-α-238GG genotypes in the ischemic stroke, SBI, and control groups (p< 0.05). CONCLUSIONS: Our results suggest that the TNF-α-308G→A polymorphism is responsible for susceptibility to ischemic stroke and is associated with high tHcy levels in Koreans.

Effects of methionine synthase and methionine synthase reductase polymorphisms on hypertension susceptibility.

BACKGROUND: Polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene are strongly associated with hypertension incidence, although such association is inconsistent among ethnicities studied. However, effects of polymorphisms of other genes related to folate metabolism besides MTHFR on hypertension susceptibility are not well known yet. OBJECTIVE: The aim of this study was to elucidate whether methionine synthase (MTR) 2756A>G and methionine synthase reductase (MTRR) 66A>G polymorphisms might be associated with risks of hypertension susceptibility in the Korean population. METHODS: Genotyping of these two polymorphisms was performed for 232 hypertensive patients and 247 unrelated healthy controls using polymerase chain reaction-restriction fragment length polymorphism technique. RESULTS: In the present study, mutations of MTR 2756A>G and MTRR 66A>G polymorphisms were associated with increased and decreased susceptibility to hypertension, respectively. Allele combinations from these two polymorphisms were also related to hypertension prevalence. When polymorphism data were stratified according to clinical components of hypertension, The G allele of MTR 2756A>G polymorphism was significantly associated with an increased risk of hypertension in subjects with BMI < 26.1 kg/m2 (P = 0.004), WC < 87.2 in. (P = 0.021), FBG < 95.5 mg/dL (P = 0.011), triglyceride < 133.5 mg/dL (P = 0.034), and HDL-cholesterol < 52.2 mg/dL (P = 0.036). The G allele of MTRR 66A>G polymorphism was significantly associated with a decreased risk of hypertension in subjects with WC ≥ 87.2 in. (P = 0.029), FBG ≥ 95.5 mg/dL (P = 0.032) and triglyceride ≥ 133.5 mg/dL (P = 0.027). CONCLUSION: MTR 2756A>G and MTRR 66A>G polymorphisms related to folate metabolism might be genetic markers for risk of hypertension in the Korean population.

Generation and manipulation of isotropic droplets in nematic medium using switchable dielectrophoresis.

Dielectrophoresis (DEP) in a medium with anisotropic dielectric susceptibility is very different from typical DEP in an isotropic medium: The direction of particle actuation can be switched depending on the direction of the susceptibility tensor of the medium. However, the understanding of switchable DEP (SDEP) in an anisotropic medium is still in its infant stage. Here, we investigate SDEP using heat-generated isotropic droplets in a nematic liquid crystal (LC) medium. We demonstrate that the location of the generation of isotropic droplets can be partially controlled by controlling the temperature gradient within the LC cell using dielectric loss. The SDEP actuation of isotropic droplets is also highly dependent on the location of the isotropic droplets. Using this method, we fabricated different array patterns of isotropic and nematic phase separations under different applied signals.

Associations of MTRR and TSER polymorphisms related to folate metabolism with susceptibility to metabolic syndrome.

BACKGROUND: Hyperhomocysteinemia is a potential risk factor for the development of metabolic syndrome (MetS). Among genes involved in homocysteine metabolism, polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene are known to be associated with MetS incidence. However, effects of polymorphisms of other folate metabolism-related genes on MetS susceptibility are not well known yet. OBJECTIVE: This study was to determine whether methionine synthase (MTR) 2756A > G, methionine synthase reductase (MTRR) 66A > G, and thymidylate synthase enhancer region (TSER) 2R/3R polymorphisms might be associated with risks of MetS development in the Korean population. METHODS: Genotype analysis of the three polymorphisms was performed for a total of 483 subjects including 236 MetS patients and 247 unrelated healthy controls using polymerase chain reaction-restriction fragment length polymorphism technique. RESULTS: The present study revealed that MTRR and TSER polymorphisms were associated with susceptibility to MetS. Several genotypes and allele combinations from the three polymorphisms were also related to the MetS prevalence. When polymorphism data were stratified according to the risk components of MetS, MTR polymorphism was significantly associated with an increased risk of MetS in subjects with systolic blood pressure < 132.7 mmHg (AOR 1.842, 95% CI 1.039-3.266, P = 0.037) and fasting blood glucose level < 106.3 mg/dL (AOR 1.772, 95% CI 1.069-2.937, P = 0.027). MTRR polymorphism was significantly associated with a decreased risk of MetS in subjects with triglyceride level < 216.3 mg/dL (AOR 0.616, 95% CI 0.399-0.951, P = 0.029). To the best of our knowledge, this is the first to provide reliable evidence about the association of other folate metabolism-related gene polymorphisms besides MTHFR with MetS susceptibility and its risk factors. CONCLUSION: Results of this study suggest that MTRR and TSER polymorphisms might be potential genetic markers for the risk of MetS development in Korean population.

Dual-field-induced biaxial nematic ordering of two-dimensional nanoparticles and enhancement of interparticle interactions.

The ordering of 2D biaxial graphene oxide (GO) particles is investigated under the application of orthogonal electric (E) and magnetic fields (B); nematic, antinematic, or biaxial nematic ordering of GO particles is selectively obtained depending on the field conditions. Particularly, a perfect biaxial nematic ordering with the highest birefringence is induced by the dual fields. Unexpectedly, the presence of B enhances the effective polarizability anisotropy, which may attribute to the enhanced steric interparticle interaction. The dual fields induce the microscopic biaxial stacking assembly of GO particles, producing grainy flocs which are not observed in a single-field condition.

Laser-Induced Nanodroplet Injection and Reconfigurable Double Emulsions with Designed Inner Structures.

Microfabrication of complex double emulsion droplets with controlled substructures, which resemble biological cells, is an important but a highly challenging subject. Here, a new approach is proposed based on laser-induced injection of water nanodroplets into a liquid crystal (LC) drop. In contrast to the conventional top-down microfluidic fabrication, this method employs a series of bottom-up strategies such as nanodroplet injection, spontaneous and assisted coalescence, elastically driven actuation, and self-assembly. Each step is controlled precisely by adjusting the laser beam, interfacial tension, and its gradients, surface anchoring, and elasticity of the LC. Whispering gallery mode illumination is used to monitor the injection of droplets. A broad spectrum of double emulsions with a predesigned hierarchical architecture is fabricated and reconfigured by temperature, laser-induced coalescence, and injection. The proposed bottom-up method to produce customized microemulsions that are responsive to environmental cues can be used in the development of drug delivery systems, biosensors, and functional soft matter microstructures.