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1.
Sensors (Basel) ; 24(5)2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38475221

ABSTRACT

The wrist is one of the most complex joints in our body, composed of eight bones. Therefore, measuring the angles of this intricate wrist movement can prove valuable in various fields such as sports analysis and rehabilitation. Textile stretch sensors can be easily produced by immersing an E-band in a SWCNT solution. The lightweight, cost-effective, and reproducible nature of textile stretch sensors makes them well suited for practical applications in clothing. In this paper, wrist angles were measured by attaching textile stretch sensors to an arm sleeve. Three sensors were utilized to measure all three axes of the wrist. Additionally, sensor precision was heightened through the utilization of the Multi-Layer Perceptron (MLP) technique, a subtype of deep learning. Rather than fixing the measurement values of each sensor to specific axes, we created an algorithm utilizing the coupling between sensors, allowing the measurement of wrist angles in three dimensions. Using this algorithm, the error angle of wrist angles measured with textile stretch sensors could be measured at less than 4.5°. This demonstrated higher accuracy compared to other soft sensors available for measuring wrist angles.

2.
ACS Appl Electron Mater ; 4(7): 3623-3631, 2022 Jul 26.
Article in English | MEDLINE | ID: mdl-35937184

ABSTRACT

Perovskite stannate SrSnO3 (SSO) is attracting attention as ultraviolet transparent conducting oxides (UV TCOs) due to its ultrawide band gap and high conductivity. Here, we investigate in detail the thickness-dependent electrical, structural, and optical properties of sequentially strain-relaxed La-doped SrSnO3 (SLSO) epitaxial thin films. We find that the SLSO films grow as an orthorhombic Pnma phase with a - a - c + in the c + direction under the tensile strain. With the strain relaxation, as the films become thicker, vertical grain boundaries are created and the orthorhombic phase becomes reoriented to all three possible orientations. Simultaneously, the conductance starts to deviate from the linear behavior with increasing film thickness. Through the analysis of thickness fringes in optical transmittance, we found that a 120 nm thick nominally 4% La-doped SrSnO3 film has a figure of merit (φTC = 2.65 × 10-3 Ω-1) at λ = 300 nm in the deep-UV region, which is the highest value among the well-known candidates for UV TCOs reported to date.

3.
Sci Adv ; 8(11): eabm3962, 2022 Mar 18.
Article in English | MEDLINE | ID: mdl-35302844

ABSTRACT

Scaling down of semiconductor devices requires high-k dielectric materials to continue lowering the operating voltage of field-effect transistors (FETs) and storing sufficient charge on a smaller area. Here, we investigate the dielectric properties of epitaxial BaHf0.6Ti0.4O3 (BHTO), an alloy of perovskite oxide barium hafnate (BaHfO3) and barium titanate (BaTiO3). We found the dielectric constant, the breakdown field, and the leakage current to be 150, 5.0 megavolts per centimeter (MV cm-1), and 10-4 amperes per square centimeter at 2 MV cm-1, respectively. The results suggest that two-dimensional (2D) carrier density of more than n2D = 1014 per square centimeter (cm-2) could be modulated by the BHTO gate oxide. We demonstrate an n-type accumulation mode FET and direct suppression of more than n2D = 1014 cm-2 via an n-type depletion-mode FET. We attribute the large dielectric constant, high breakdown field, and low leakage current of BHTO to the nanometer scale stoichiometric modulation of hafnium and titanium.

4.
Adv Mater ; 34(10): e2109144, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34936713

ABSTRACT

Matter-light interaction is at the center of diverse research fields from quantum optics to condensed matter physics, opening new fields like laser physics. A magnetic exciton is one such rare example found in magnetic insulators. However, it is relatively rare to observe that external variables control matter-light interaction. Here, it is reported that the broken inversion symmetry of multiferroicity can act as an external knob enabling magnetic excitons in the van der Waals antiferromagnet NiI2 . It is further discovered that this magnetic exciton arises from a transition between Zhang-Rice-triplet and Zhang-Rice-singlet fundamentally quantum-entangled states. This quantum entanglement produces an ultrasharp optical exciton peak at 1.384 eV with a 5 meV linewidth. The work demonstrates that NiI2 is 2D magnetically ordered with an intrinsically quantum-entangled ground state.

5.
Nano Lett ; 21(12): 5126-5132, 2021 Jun 23.
Article in English | MEDLINE | ID: mdl-34096728

ABSTRACT

Realizing a state of matter in two dimensions has repeatedly proven a novel route of discovering new physical phenomena. Van der Waals (vdW) materials have been at the center of these now extensive research activities. They offer a natural way of producing a monolayer of matter simply by mechanical exfoliation. This work demonstrates that the possible multiferroic state with coexisting antiferromagnetic and ferroelectric orders persists down to the bilayer flake of NiI2. By exploiting the optical second-harmonic generation technique, both magnitude and direction of the ferroelectric order, arising from the cycloidal spin order, are successfully traced. The possible multiferroic state's transition temperature decreases from 58 K for the bulk to about 20 K for the bilayer. Our observation will spur extensive efforts to demonstrate multifunctionality in vdW materials, which have been tried mostly by using heterostructures of singly ferroic ones until now.

6.
ACS Omega ; 6(21): 13802-13806, 2021 Jun 01.
Article in English | MEDLINE | ID: mdl-34095672

ABSTRACT

Terahertz spectroscopy can be utilized as an effective nondestructive identification tool for the study of artist's pigments. Consequently, extensive measurements have been conducted on representative pigment species, and a few terahertz spectral databases have been constructed. However, the reported spectra were often acquired from pigment samples mixed with polyethylene at room temperature with low resolution, which often led to low-quality spectra with unresolved overlapping lines further broadened due to thermal effects. Here, we present our study of vermilion (HgS, mercury sulfide) as an illustration of how we can overcome such difficulties by studying free-standing oil-paint samples at room temperature and then by performing low-temperature measurements on polyethylene-mixed samples to minimize line broadening due to thermal effects. Our results identify clearly resolved absorption peaks due to lattice vibrations of vermilion at 40.4, 44.5, and 89.9 cm-1 at 2 K. The temperature dependence of the peak shift and line broadening reveals anharmonic characteristics of these lattice vibrational modes. Our approach will definitely suggest new ways to improve and enhance existing terahertz spectral databases of ancient and modern pigments toward actual analysis, diagnosis, and conservation of heritage artworks.

7.
J Stroke Cerebrovasc Dis ; 26(6): 1383-1390, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28412319

ABSTRACT

BACKGROUND: Warfarin has a narrow therapeutic window. We hypothesized that genetic factors related to warfarin metabolism (CYP2C9) and activity (VKORC1) would show stronger associations than modifiable factors with the quality of anticoagulation control and risks for thromboembolism and hemorrhage. METHODS: In this retrospective cohort analysis, clinical and genetic data were collected from 380 patients with atrial fibrillation (AF) who were followed for an average observation period of 4 years. We evaluated the factors associated with time in therapeutic range (TTR, international normalized ratio [INR]: 2-3) and vascular events (either thromboembolic or hemorrhagic), including both genetic (CYP2C9 and VKORC1 genotype) and modifiable factors (anticoagulation service and warfarin dose assessment interval). RESULTS: The genotypic frequency of CYP2C9*3 (rs1057910) was 9.5% and that of VKORC1 1173C>T (rs9934438) was 16.3%. TTR showed dependence on VKORC1 polymorphism: TTR was higher in carriers of the VKORC1 1173C>T than of the VKORC1 TT genotype (61.7 ± 16.0% versus 56.7 ± 17.4%, P = .031). Multivariate testing showed that the VKORC1 genotype and anticoagulation service were independently related to labile INRs (TTR <65%). Vascular events were observed in 66 patients (18.4%) during the study period. A Cox proportional hazard model showed that the use of anticoagulation service and patients' characteristics, such as AF-thromboembolic risk (CHA2DS2-VASc score: Congestive heart failure, Hypertension, Age 75 years or older, Diabetes mellitus, previous Stroke or transient ischemic attack, Vascular disease, Age 65 to 74 years, female) and consequence (neurologic disability), but not genetic factors, were independently associated with vascular events. CONCLUSIONS: Both genetic factor (VKORC1 genotype) and clinical efforts (anticoagulation service) influenced the quality of anticoagulation control. However, clinical events were more strongly associated with patient characteristics and clinical efforts than with genetic factors.


Subject(s)
Anticoagulants/therapeutic use , Atrial Fibrillation/drug therapy , Blood Coagulation/drug effects , Cytochrome P-450 CYP2C9/genetics , Pharmacogenomic Variants , Stroke/prevention & control , Thromboembolism/prevention & control , Vitamin K Epoxide Reductases/genetics , Aged , Aged, 80 and over , Anticoagulants/adverse effects , Atrial Fibrillation/blood , Atrial Fibrillation/diagnosis , Atrial Fibrillation/genetics , Blood Coagulation/genetics , Chi-Square Distribution , Cytochrome P-450 CYP2C9/metabolism , Drug Monitoring/methods , Female , Gene Frequency , Hemorrhage/chemically induced , Hemorrhage/genetics , Humans , International Normalized Ratio , Linear Models , Logistic Models , Male , Middle Aged , Multivariate Analysis , Odds Ratio , Pharmacogenetics , Pharmacogenomic Testing , Proportional Hazards Models , Retrospective Studies , Risk Assessment , Risk Factors , Stroke/blood , Stroke/diagnosis , Stroke/genetics , Thromboembolism/blood , Thromboembolism/diagnosis , Thromboembolism/genetics , Time Factors , Treatment Outcome
8.
Case Rep Neurol Med ; 2016: 7575623, 2016.
Article in English | MEDLINE | ID: mdl-27648322

ABSTRACT

During gross anatomy head and neck laboratory session, one dissection group observed an abnormal anatomic variation in the posterior cranial fossa of a 94-year-old male cadaver. The internal occipital crest was not aligned with internal occipital protuberance and groove for superior sagittal sinus. It seemed that the internal occipital protuberance was shifted significantly to the right side. As a result the skull was overly stretched in order to connect with the internal occipital ridge. These internal skull variations of occipital bone landmarks can influence the location of adjacent dural venous sinuses and possibly influence cerebrospinal fluid flow. Similar anatomical anomalies have been attributed to presence of hydrocephalus and abnormalities in cisterna magna.

9.
J Environ Sci (China) ; 42: 275-283, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27090720

ABSTRACT

We have developed a new nanofilter using a carbon nanotube-silver composite material that is capable of efficiently removing waterborne viruses and bacteria. The nanofilter was subjected to plasma surface treatment to enhance its flow rate, which was improved by approximately 62%. Nanoscale pores were obtained by fabricating a carbon nanotube network and using nanoparticle fixation technology for the removal of viruses. The pore size of the nanofilter was approximately 38 nm and the measured flow rate ranged from 21.0 to 97.2L/(min·m(2)) under a pressure of 1-6 kgf/cm(2) when the amount of loaded carbon nanotube-silver composite was 1.0 mg/cm(2). The nanofilter was tested against Polio-, Noro-, and Coxsackie viruses using a sensitive real-time polymerase chain reaction assay to detect the presence of viral particles within the outflow. No trace of viruses was found to flow through the nanofilter with carbon nanotube-silver composite loaded above 0.8 mg/cm(2). Moreover, the surface of the filter has antibacterial properties to prevent bacterial clogging due to the presence of 20-nm silver nanoparticles, which were synthesized on the carbon nanotube surface.


Subject(s)
Bacteria , Filtration/instrumentation , Nanotubes, Carbon , Silver , Viruses , Water Microbiology , Water Purification/methods
10.
J Stroke ; 17(2): 192-8, 2015 May.
Article in English | MEDLINE | ID: mdl-26060806

ABSTRACT

BACKGROUND AND PURPOSE: Advantages of new oral anticoagulations may be greater in atrial fibrillation (AF) patients of poor anticoagulation control with warfarin. The SAMe-TT2R2 scoring system, based on clinical variables, was recently developed to aid in identifying these patients. In this study, we investigated the association of this clinical composite score with genetic factors related warfarin dosing and the quality of anticoagulation control. METHODS: Clinical and genetic data were collected from 380 consecutive Korean patients with AF (CHA2DS2-VASc score, 3.5±1.8) who were followed for an average of 4 years. We evaluated factors associated with time in therapeutic range (TTR, INR 2-3), including the CYP2C9 and VKORC1 genotypes and the SAMe-TT2R2 score (Sex female, Age <60 years, Medical history [>two co-morbidities], Treatment [interacting drugs, e.g., amiodarone], Tobacco use within 2 years [doubled], and Race non-white [doubled]). RESULTS: The average SAMe-TT2R2 score was 3.4±0.9, range 2-7; and 153 patients (40.2%) had SAMe-TT2R2 scores ≥4. Time in specific INR ranges varied depending on the VKORC1 genotype but not with the CYP2C9 genotype or the SAMe-TT2R2 score. TTR was higher in patients with the VKORC1 1173C>T than in VKORC1 TT (61.7±16% vs. 56.7±17.4%, P=0.031). Multivariate testing showed that VKORC1 genotype but not the SAMe-TT2R2 score was significantly associated with labile INRs. There was no correlation between the SAMe-TT2R2 scores and pharmacogenetic data. CONCLUSIONS: A genetic factor, but none of the common clinical and demographic factors, as combined in the SAMe-TT2R2 score, was associated with the quality of anticoagulation control in Korean patients with AF.

11.
Electrolyte Blood Press ; 10(1): 26-30, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23508726

ABSTRACT

We report a rare case of the concurrent manifestation of central diabetes insipidus (CDI) and type 2 diabetes mellitus (DM). A 56 year-old man was diagnosed as a type 2 DM on the basis of hyperglycemia with polyuria and polydipsia at a local clinic two months ago and started an oral hypoglycemic medication, but resulted in no symptomatic improvement at all. Upon admission to the university hospital, the patient's initial fasting blood sugar level was 140 mg/dL, and he showed polydipsic and polyuric conditions more than 8 L urine/day. Despite the hyperglycemia controlled with metformin and diet, his symptoms persisted. Further investigations including water deprivation test confirmed the coexisting CDI of unknown origin, and the patient's symptoms including an intense thirst were markedly improved by desmopressin nasal spray (10 µg/day). The possibility of a common origin of CDI and type 2 DM is raised in a review of the few relevant adult cases in the literature.

12.
J Cardiovasc Pharmacol ; 47(1): 96-102, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16424792

ABSTRACT

The effects of ketanserin, a 5-HT2 antagonist, on the ATP-sensitive K+ (K(ATP)) channels were studied in mouse ventricular myocytes using patch clamp technique. Under the whole-cell voltage clamp conditions, ketanserin (1-100 microM) reversibly inhibited pinacidil-induced K(ATP) current in a concentration-dependent fashion with a Ki value of 9.36 microM and the Hill coefficient was 0.67. This inhibition was developed even with the presence of 5-hydroxytryptamine (100 microM) in the bath. Prazosin, a selective alpha1-antagonist, also failed to mimic the effect of ketanserin. Ketanserin did not affect the channel activity in inside-out configuration under the ATP-free internal solution. Furthermore, ketanserin applied to the external solution did not affect the pinacidil-induced channel activity in the cell-attached patches, but did inhibit it when applied into the pipette. These results suggest that the inhibitory action of ketanserin observed in this study was probably due to a direct action on the K(ATP) channel rather than to an action through the 5-HT2 receptor or alpha1-adrenoceptor blockade, and that the antiarrhythmic activity of ketanserin against cardiac arrhythmias induced in the ischemic/reperfused heart is at least in part attributable to its inhibition of the K(ATP) channel.


Subject(s)
Adenosine Triphosphate/pharmacology , Ketanserin/pharmacology , Myocytes, Cardiac/drug effects , Potassium Channel Blockers/pharmacology , Potassium Channels/drug effects , Serotonin Antagonists/pharmacology , Animals , Anti-Arrhythmia Agents/pharmacology , Membrane Potentials/drug effects , Mice , Mice, Inbred ICR , Myocytes, Cardiac/metabolism , Potassium Channels/physiology , Receptors, Adrenergic, alpha-1/physiology , Receptors, Serotonin, 5-HT2/physiology
13.
Biochem Biophys Res Commun ; 313(1): 156-62, 2004 Jan 02.
Article in English | MEDLINE | ID: mdl-14672712

ABSTRACT

Previously, we identified a novel neuron-specific protein (PAHX-AP1) that binds to Refsum disease gene product (PAHX), and we developed transgenic (TG) mice that overexpress heart-targeted PAHX-AP1. These mice have atrial tachycardia and increased susceptibility to aconitine-induced arrhythmia. This study was undertaken to elucidate the possible changes in ion channels underlying the susceptibility to arrhythmia in these mice. RT-PCR analyses revealed that the cardiac expression of adrenergic beta(1)-receptor (ADRB1) was markedly lower, whereas voltage-gated potassium channel expression (Kv2.1) was higher in PAHX-AP1 TG mice compared with non-TG mice. However, the expression of voltage-sensitive sodium and calcium channels, and muscarinic receptor was not significantly different. Propranolol pretreatment, a non-specific beta-adrenoceptor antagonist, blocked aconitine-induced arrhythmia in non-TG mice, but not in PAHX-AP1 TG mice. Our results indicate that, in the PAHX-AP1 TG heart, the modulation of voltage-gated potassium channel and ADRB1 expression seem to be important in the electrophysiological changes associated with altered ion channel functions, but ADRB1 is not involved in the greater susceptibility to aconitine-induced arrhythmia.


Subject(s)
Arrhythmias, Cardiac/metabolism , Carrier Proteins/genetics , Nerve Tissue Proteins/genetics , Potassium Channels, Voltage-Gated/biosynthesis , Receptors, Adrenergic, beta-1/biosynthesis , Aconitine/toxicity , Action Potentials , Animals , Arrhythmias, Cardiac/chemically induced , Arrhythmias, Cardiac/genetics , Arrhythmias, Cardiac/physiopathology , Blood Pressure/drug effects , Blood Pressure/physiology , Carrier Proteins/biosynthesis , Female , Gene Expression Regulation/genetics , Genetic Predisposition to Disease , Heart Rate/drug effects , Heart Rate/physiology , Intracellular Signaling Peptides and Proteins , Ion Channels/biosynthesis , Male , Mice , Mice, Transgenic , Nerve Tissue Proteins/biosynthesis , Propranolol/pharmacology , Receptors, Muscarinic/biosynthesis , Refsum Disease/genetics
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