335 research outputs found

    Influence of the waist diameters on transmission characteristics and strain sensitivity of microtapered long-period fiber gratings

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    Transmission characteristics of microtapered long-period fiber gratings (MTLPGs) and their strain and temperature sensitivities with variations in the waist diameters are investigated theoretically and experimentally. Transmission characteristics of MTLPGs strongly depend on the waist diameter of the tapered optical fiber (TOF) because of the modification of the effective index difference between the core and the cladding modes. Based on the photoelastic effect, the resonant wavelengths of MTLPGs with variations in strain shift to shorter wavelengths. The strain sensitivity of the MTLPG with a waist diameter of 25 μm is improved by a factor of 20 compared with that of a 125 μm long-period fiber grating. The temperature sensitivities of MTLPGs are also enhanced by reducing the waist diameter of the TOF

    Concentrations of HMGB1 and Hsp70 of healthy subjects in upper and lower airway: Literature Review and Meta-analysis

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    Although high-mobility group box 1 and heat-shock protein 70 are implicated in airway diseases and suggested as relevant diagnostic biomarkers, their control concentrations in the airways have not yet been determined. This study aimed to evaluate concentration of healthy subjects for both these proteins in the upper and lower airways via meta-analysis. We searched MEDLINE, EMBASE, and Google Scholar for articles describing concentration of healthy subjects for these proteins. Data from healthy populations were combined using a random-effects model, and subgroup and sensitivity analyses were performed to determine between-study heterogeneity. We analyzed 22 studies involving 485 patients. Concentration of healthy subjects of high-mobility group box 1 and heat-shock protein 70 varied from "not detected" to 326.13 ng/mL and from 0.20 pg/mL to 9240.00 pg/mL, respectively, with the values showing significant heterogeneity. Subgroup analysis for high-mobility group box 1 revealed 13.63 ng/mL (95% CI 12.13-15.14), 100.31 ng/mL (95% CI -31.28-231.91), 9.54 ng/mL (95% CI 8.91-10.17), and 65.82 ng/mL (95% CI 55.51-76.14) for the lower airway, upper airway, pediatric populations, and adults, respectively, whereas that for heat-shock protein 70 revealed 20.58 pg/mL (95% CI 7.87-33.29) for the lower airway and 9240.00 ±11820 pg/mL for the upper airway. Although concentrations of healthy subjects of these proteins varied in the upper and lower airways, the levels of both these proteins were higher in the upper airway than in the lower airway, and these concentrations differed according to the age and sampling procedure. Our findings support the further evaluation of these proteins as biomarkers for airway-related diseases

    Relationship Between Otorhinolaryngologic Diseases and Obesity

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    ObjectivesObesity rates have been increasing for all population groups worldwide, leading to the increased development of various diseases. This study was designed is to identify the relationships between obesity and several important otorhinolaryngologic diseases, including chronic otitis media (COM), chronic rhinosinusitis, and chronic tonsillitis.MethodsMean body mass index (BMI) was compared in patients with COM, rhinosinusitis, and tonsillitis and in a control group. The relationships among the prevalence rates of overweight and obesity, morbidity period, and BMI were assessed in each group.ResultsMean BMIs in the COM, rhinosinusitis, and tonsillitis groups were 24.45±2.72 kg/m2, 24.68±3.25 kg/m2, and 24.67±3.82 kg/m2, respectively, with each significantly higher than in the control group (23.22±3.01 kg/m2, P0.05 each).ConclusionMean BMI and the prevalence of obesity were elevated in the three groups of patients with representative otorhinolaryngologic inflammatory diseases, including COM, chronic rhinosinusitis, and chronic tonsillitis

    Depolarization mitigated in ferroelectric Hf0.5Zr0.5O2 ultrathin films (< 5 nm) on Si substrate by interface engineering

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    (Hf,Zr)O2 offers considerable potential for next-generation semiconductor devices owing to its nonvolatile spontaneous polarization at the nanoscale. However, scaling this material to sub-5 nm thickness poses several challenges, including the formation of an interfacial layer and high trap concentration. In particular, a low-k SiO2 interfacial layer is naturally formed when (Hf,Zr)O2 films are directly grown on a Si substrate, leading to high depolarization fields and rapid reduction of the remanent polarization. To address these issues, we conducted a study to significantly improve ferroelectricity and switching endurance of (Hf,Zr)O2 films with sub-5 nm thicknesses by inserting a TiO2 interfacial layer. The deposition of a Ti film prior to Hf0.5Zr0.5O2 film deposition resulted in a high-k TiO2 interfacial layer and prevented the direct contact of Hf0.5Zr0.5O2 with Si. Our findings show that the high-k TiO2 interfacial layer can reduce the SiO2/Si interface trap density and the depolarization field, resulting in a switchable polarization of 60.2 μC/cm2 for a 5 nm thick Hf0.5Zr0.5O2 film. Therefore, we propose that inserting a high-k TiO2 interfacial layer between the Hf0.5Zr0.5O2 film and the Si substrate may offer a promising solution to enhancing the ferroelectricity and reliability of (Hf,Zr)O2 grown on the Si substrate and can pave the way for next-generation semiconductor devices with improved performance

    A case study on swell correction of Chirp sub-bottom profiler (SBP) data using multi-beam echo sounder (MBES) data

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    High-resolution marine seismic data acquisition and subsequent analyses are highly influenced by sea conditions, directly affecting data quality and interpretation. Traditional swell effect correction methods are effective in improving reflector continuity; however, they are less useful for enhancing travel time consistency at intersection points of crossing lines. To develop a robust swell-removal technique for a set of crossing lines multi-beam echo sounder (MBES) data and Chirp sub-bottom profiler (SBP) data were acquired. After generation of a time structure map of the sea-bottom converted from the final processed multi-beam data, a moving average was used to improve the event continuity of the sea-bottom reflection of the Chirp SBP data. Using the position of the Chirp SBP data, the difference between the travel time of the sea-bottom from the smoothed map and the original travel time of the sea-bottom is calculated as a static correction. The static correction method based on the MBES data was compared and verified using three different cases: (i) simple 2D swell effect correction on a line-by-line basis, (ii) comparing the swell corrections at the crossing positions of 2D lines acquired from different dates, and (iii) comparison of ties of intersection points between 2D lines after new swell correction applied. Although a simple 2D swell correction showed great enhancement of reflector continuity, only the full static correction using the newly proposed method using MBES data produced completely corrected reflection events especially at the crossing points of 2D lines

    Anti-inflammatory effects of isoketocharbroic acid from brown alga, Sargassum micracanthum

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    During our on-going screening program designed to isolate natural compounds from marine environments, we isolated isoketochabrolic acid (IKCA) from Sargassum micracanthum, an important brown algae distributed in Jeju Island, Korea. Furthermore, we evaluated the inhibitory effects of IKCA on nitric oxide (NO) production in lipopolysaccharide (LPS)-triggered macrophages. IKCA strongly inhibited NO production, with an IC50 value of 58.31 μM. Subsequent studies demonstrated that IKCA potently and concentration-dependently reduced prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-6 cytokine production. In conclusion, to the best of our knowledge, this is the first study to show that IKCA isolated from S. micracanthum has a potent anti-inflammatory activity. Therefore, IKCA might be useful as an anti-inflammatory health supplement or functional cosmetics

    Flash Pulmonary Edema in a Patient With Unilateral Renal Artery Stenosis and Bilateral Functioning Kidneys

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    Flash pulmonary edema typically exhibits sudden onset and resolves rapidly. It generally is associated with bilateral renal artery stenosis or unilateral stenosis in conjunction with a single functional kidney. We describe a patient who presented with flash pulmonary edema treated by percutaneous therapy with stent implantation. Our case is unique in that the flash pulmonary edema occurred in the setting of unilateral renal artery stenosis with bilateral functioning kidneys

    Association between physical activity and episodic memory and the moderating effects of the apolipoprotein E ε4 allele and age

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    BackgroundAn abundance of evidence indicates that physical activity may protect against Alzheimer’s disease (AD) and related cognitive decline. However, little is known about the association between physical activity and AD-related cognitive decline according to age and the apolipoprotein E (APOE) ε4 allele (APOE4) as major risk factors. Therefore, we examined whether age and APOE4 status modulate the effects of physical activity on episodic memory as AD-related cognition in non-demented older adults.MethodsWe enrolled 196 adults aged between 65 and 90 years, with no dementia. All participants underwent comprehensive clinical assessments including physical activity evaluation and APOE genotyping. The AD-related cognitive domain was assessed by the episodic memory, as the earliest cognitive change in AD, and non-memory cognition for comparative purposes. Overall cognition was assessed by the total score (TS) of the Consortium to Establish a Registry for Alzheimer’s Disease neuropsychological battery.ResultsWe found significant physical activity × age and physical activity × APOE4 interaction effects on episodic memory. Subgroup analyses indicated that an association between physical activity and increased episodic memory was apparent only in subjects aged > 70 years, and in APOE4-positive subjects.ConclusionOur findings suggest that physical activity has beneficial effects on episodic memory, as an AD-related cognitive domain, in individuals aged > 70 years and in APOE4-positive individuals. Physicians should take age and APOE4 status account into when recommending physical activity to prevent AD-related cognitive decline
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