Stretchable Chiral Liquid Crystal ElastomersIn article number 2304506, Su Seok Choi and co‐workers reveal optical characteristics of the multiaxial (uniaxial, biaxial, and out‐of‐plane) ...mechanochromic color change mechanism of chiral liquid crystal elastomers (CLCEs). In contrast to the helix unwinding of CLCEs with losing circular polarization under uniaxial stretching, maintaining optical polarization under symmetrical stretching (biaxial and out‐of‐plane) for informative 3D stretching of CLCEs are reported.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
•The effect of the shape parameter of fan-shaped holes on film cooling effectiveness was experimentally investigated using the PSP (Pressure Sensitive Paint) technique.•The optimum value of shape ...parameters also derived using the response surface methodology.•The film cooling effectiveness is higher for the higher density ratio condition, but the effect of the blowing ratio was not consistent.•Generally, the overall averaged film cooling effectiveness increased as the area ratio increased up to the optimum point.•The optimum area ratio at which the film cooling effectiveness was maximized increased as the blowing ratio increased.•At the near gas turbine operating condition, the optimized hole showed 52.4% higher overall film cooling effectiveness than that of the reference hole.
In this study, the effect of the shape parameters of fan-shaped holes on film cooling effectiveness was experimentally investigated and the optimum values of each shape parameter to maximize the overall averaged film cooling effectiveness were presented. Among the shape parameters of a fan-shape hole, the injection angle and the hole length to diameter ratio (L/D) were fixed as 30 degrees and 6, respectively, and the three shape parameters, the forward expansion angle, the lateral expansion angle, and the metering length ratio, were selected as variables. The design points of each parameter were selected using the Box-Behnken design method, and the optimized values of each parameter were obtained using RSM (Response Surface Methodology). The film cooling effectiveness was measured using the PSP (pressure sensitive paint) technique. The experiment was conducted under the condition of two density ratios (1.0 and 2.0) and four blowing ratios (1.0, 1.5, 2.0, and 2.5). Results showed that the film cooling effectiveness was generally higher for the higher density ratio condition, but the effect of the blowing ratio was not consistent. The main effect analysis showed that film cooling effectiveness increased as the forward and the lateral expansion angles increased, and the metering length became shorter. However, optimization results showed that the optimized hole had a smaller forward expansion angle due to the interaction effect between each shape parameter. The film cooling effectiveness of the optimized hole was higher than that of the reference hole by 52.4% near the gas turbine operating condition.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Treatment of heart failure (HF) in the elderly face many difficulties due to lack of robust evidence. We analyzed the outcome of HF in octogenarians using a nationwide HF registry. Among 5625 ...patients from the Korean Acute Heart Failure (KorAHF) registry, prognosis of octogenarian HF and the association of guideline-directed medical therapy (GDMT) with mortality and readmissions were analyzed. Octogenarian patients (1185, 22.4%) showed a higher mortality, and males were especially at increased risk (HR (hazard ratio) 1.19, 95% CI 1.01-1.40). A J-curve association between blood pressure (BP) and mortality was observed regardless of age, but the nadir value was lower in octogenarians (123.8 vs. 127.9 mmHg for systolic blood pressure (SBP); 67.1 vs. 73.9 mmHg for diastolic blood pressure (DBP),
< 0.001). Use of GDMT in octogenarian patients with HF and reduced ejection fraction (EF) were inadequate (74.3%, 47.1%, and 46.1% in octogenarians vs. 78.4%, 59.8%, and 55.2% in non-elderly for renin-angiotensin system inhibitors, beta-blockers, and aldosterone antagonists, respectively; all
< 0.05). However, those on medications had a significant reduction in 6 month mortality. For octogenarians with HF and preserved EF, angiotensin receptor blocker use reduced hospitalizations for HF in men (HR 0.19, 95% CI 0.04-0.87), but not in women (
-interaction = 0.037). HF in octogenarians were found to have different characteristics compared with the non-elderly. However, adequate use of GDMT was still associated with improved survival, and more attention should be given to prescribing medications with clinical benefits.
Complex concentrated alloys (CCAs) with a face-centered-cubic (FCC) structure exhibit remarkable mechanical properties, introducing the expansion of compositional space in alloy design for structural ...materials. The formation of a single solid-solution phase is enabled by configuring various 3d-transition elements, while doping other elements even of a small portion generally leads to the formation of brittle intermetallic compounds. Herein, we demonstrate through a systematic investigation of single FCC (CoNi)100-xMox alloys that a wide range of refractory element Mo can simultaneously improve the strength and ductility while sustaining the solid-solution structure. The addition of Mo with a larger atomic size than those of 3d-transition elements introduces severe lattice distortion in the FCC lattice and causes grain-boundary segregation enriched by Mo atoms. In addition, increasing Mo content effectively reduces the stacking fault energy (SFE). The increased lattice distortion with Mo content enhances the solid-solution strengthening of the alloys. Besides, along with reduced SFE and stabilization of the dislocation emission site by grain-boundary segregation, this elevated solid-solution strengthening increases grain-boundary strengthening, reaching a yield strength of ∼1 GPa. Moreover, the reduction of SFE with increasing Mo results in the transition of dislocation substructures and the refinement of deformation twins, allowing for enhanced strain-hardening capability and thus ∼1.3 GPa tensile strength and ∼50% ductility. Such compositive and synergetic effects of refractory element Mo enable the CCAs with a single FCC solid solution to overcome the strength and ductility trade-off.
Display omitted
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Although neurotransmitters are key substances closely related to evaluating degenerative brain diseases as well as regulating essential functions in the body, many research efforts have not been ...focused on direct observation of such biochemical messengers, rather on monitoring relatively associated physical, mechanical, and electrophysiological parameters. Here, a bioresorbable silicon‐based neurochemical analyzer incorporated with 2D transition metal dichalcogenides is introduced as a completely implantable brain‐integrated system that can wirelessly monitor time‐dynamic behaviors of dopamine and relevant parameters in a simultaneous mode. An extensive range of examinations of molybdenum/tungsten disulfide (MoS2/WS2) nanosheets and catalytic iron nanoparticles (Fe NPs) highlights the underlying mechanisms of strong chemical and target‐specific responses to the neurotransmitters, along with theoretical modeling tools. Systematic characterizations demonstrate reversible, stable, and long‐term operational performances of the degradable bioelectronics with excellent sensitivity and selectivity over those of non‐dissolvable counterparts. A complete set of in vivo experiments with comparative analysis using carbon‐fiber electrodes illustrates the capability for potential use as a clinically accessible tool to associated neurodegenerative diseases.
A soft, wireless, and bioresorbable neurochemical system designed to determine various concentrations of neurotransmitters as well as to monitor peripheral physiologies (temperature, pH, electrical activity) in a simultaneous manner is presented. An extensive range of studies covers modifications of nanoscale materials and system‐level electronics, enabling the production of exceptional performance.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract Background Higher systolic blood pressure (SBP) has been reported to be associated with a better prognosis in heart failure (HF) patients. This study aimed to investigate the prognostic ...impact of hypertension in patients hospitalized with systolic HF. Methods Pooled analysis of data from three Korean observational studies was performed. Patients ≥18 years hospitalized with systolic HF (ejection fraction ≤45%) ( n = 3538) were compared for the incidence of 1-year all-cause mortality according to the presence of preexisting hypertension and SBP quartiles on admission. Results Patients with hypertension (prevalence, 51.6%) presented more often with diabetes (43.9% vs. 23.0%, p < 0.001) and chronic kidney disease (14.1% vs. 5.7%, p < 0.001). During the 1-year follow-up, patients with hypertension showed similar cumulative incidences of all-cause mortality as those without hypertension (8.3% vs. 8.4%, p = 0.900). Conversely, patients with higher SBP on admission had a lower incidence of all-cause death (quartile 4 vs. 1: 6.7% vs. 11.3%, p for trend = 0.004). In the multivariate analysis, an increase in SBP of 10 mmHg was associated with an 8.5% risk reduction of all-cause death (hazard ratio: 0.915, 95% confidence interval: 0.853–0.981, p = 0.013). Conclusions Higher SBP on admission was independently associated with a lower risk of 1-year all-cause mortality in systolic HF.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study investigated the prognostic power of corrected QT (QTc) interval in patients with acute heart failure (AHF) according to sex.
We analyzed multicenter Korean Acute Heart Failure registry ...with patients with AHF admitted from 2011 to 2014. Among them, we analyzed 4,990 patients who were followed up to 5 years. Regarding QTc interval based on 12 lead electrocardiogram, patients were classified into quartiles according to sex.
During follow-up with median 43.7 months, 2,243 (44.9%) patients died. The relationship between corrected QT interval and all-cause mortality followed a J-curve relationship. In Kaplan-Meier analysis, both sex had lowest mortality in the second QTc quartile. There were significant prognostic differences between the second and the fourth quartiles in male (log-rank p = 0.002), but not in female (log-rank p = 0.338). After adjusting covariates, the third (hazard ratio HR, 1.185; 95% confidence interval CI, 1.001 to 1.404; p = 0.049) and the fourth (HR, 1.404; 95% CI, 1.091 to 1.535; p = 0.003) quartiles demonstrated increased risk of mortality compared to the second quartile in male. In female, however, there was no significant difference across quartiles. QTc interval was associated with 5-year all-cause mortality in J-shape with nadir of 440 to 450 ms in male and 470 to 480 ms in female.
QTc interval was an independent predictor of overall death in male, but its significance decreased in female. The relationship between QTc interval and all-cause mortality was J-shaped in both sex.
Exosomes contain natural cargo molecules, such as miRNA, mRNA, and proteins, and transfer these functional cargos to neighboring or distant cells through circulation. In the wound-healing process, ...exosomes in the human blood and body fluids perform various functions, including proliferation, angiogenesis, differentiation, and wound healing, owing to their unique compositions. However, there is very limited information on the wound-healing effect of proteins in human cord blood plasma exosomes (CBPexo). Therefore, we studied the wound-healing potential of these proteins in terms of fibroblast functions, angiogenesis, and M2 macrophage differentiation. When scratch wound assays were conducted using human fibroblasts, CBPexo exhibited better wound-healing effects than adult blood plasma exosomes (ABPexo). CBPexo also promoted angiogenesis and differentiation of M2 macrophages, thus promoting the transition from inflammation to proliferation. To evaluate the CBPexo molecules involved, five proteins, GAL-3, GAL-7, HSP-72, PIP, and S100-A7, were selected through proteomic analysis, and their functions were investigated using an artificial exosome that expresses these proteins. Among these, HSP72 and PIP exhibited wound-healing effects similar to CBPexo. Furthermore, artificial exosomes expressing both HSP72 and PIP showed better wound-healing effects than CBPexo. Therefore, the use of artificial CBPexo can potentially overcome the limitations related to exosome production from CB.
To evaluate the CBPexo molecules involved, five proteins, GAL-3, GAL-7, HSP-72, PIP, and S100-A7, were selected through proteomic analysis, and their functions were investigated using an artificial exosome that expresses these proteins.
Voltage-gated potassium (Kv) channels, including Kv3.1 and Kv3.4, are known as oxygen sensors, and their function in hypoxia has been well investigated. However, the relationship between Kv channels ...and tumor hypoxia has yet to be investigated. This study demonstrates that Kv3.1 and Kv3.4 are tumor hypoxia-related Kv channels involved in cancer cell migration and invasion. Kv3.1 and Kv3.4 protein expression in A549 and MDA-MB-231 cells increased in a cell density-dependent manner, and the pattern was similar to the expression patterns of hypoxia-inducible factor-1α (HIF-1α) and reactive oxygen species (ROS) according to cell density, whereas Kv3.3 protein expression did not change in A549 cells with an increase in cell density. The Kv3.1 and Kv3.4 blocker blood depressing substance (BDS) did not affect cell proliferation; instead, BDS inhibited cell migration and invasion. We found that BDS inhibited intracellular pH regulation and extracellular signal-regulated kinase (ERK) activation in A549 cells cultured at a high density, potentially resulting in BDS-induced inhibition of cell migration and invasion. Our data suggest that Kv3.1 and Kv3.4 might be new therapeutic targets for cancer metastasis.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
PDF
