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This study aimed to determine the effects of virtual reality (VR)-based meditation on the sleep quality, stress, and autonomic nervous system balance of nursing students. Nursing students were categorized into experimental groups I (VR-based meditation) and II (concentration meditation) and a control group. Before the study's initiation, we measured the participants' general characteristics, and a sleep measurement device was used to measure sleep quality. Stress levels and heart rate variability were measured before and after study completion. On the first day, all three groups slept without any intervention. On days 2-6, only experimental groups I and II implemented the intervention before sleeping. We found that the subjective sleep quality, wakefulness after sleep onset, sleep efficiency, deep sleep quality, subjective stress, objective stress, and autonomic nervous system balance of the VR meditation group were significantly better than those of the other groups. Our results reveal that the participants who underwent VR-based meditation experienced better sleep quality, lower stress levels, and improved autonomic nervous system balance compared with those in the concentration meditation and control groups. Thus, VR-based meditation effectively enhances sleep quality, lowers stress levels, and improves autonomic nervous system balance in nursing students.
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Terahertz (THz) waves, known as non-ionizing radiation owing to their low photon energies, can actually ionize atoms and molecules when a sufficiently large number of THz photons are concentrated in time and space. Here, we demonstrate the generation of ionizing, multicycle, 15-THz waves emitted from large-area lithium niobate crystals via phase-matched optical rectification of 150-terawatt laser pulses. A complete characterization of the generated THz waves in energy, pulse duration, and focal spot size shows that the field strength can reach up to 260 megavolts per centimeter. In particular, a single-shot THz interferometer is employed to measure the THz pulse duration and spectrum with complementary numerical simulations. Such intense THz pulses are irradiated onto various solid targets to demonstrate THz-induced tunneling ionization and plasma formation. This study also discusses the potential of nonperturbative THz-driven ionization in gases, which will open up new opportunities, including nonlinear and relativistic THz physics in plasma.
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High-density lipoprotein (HDL) therapy has demonstrated beneficial effects in acute stroke and acute myocardial infarction models by reducing infarct size. In this study, we investigated the inhibitory effects of reconstituted HDL (rHDL) on neointimal hyperplasia and elucidated its underlying mechanism using a balloon injury rat model. Our finding revealed a significant 37% reduction in the intima to media ratio in the arteries treated with 80 mg/kg rHDL compared to those subjected to injury alone (p < 0.05), indicating a specific inhibition of neointimal hyperplasia. In vivo analysis further supported the positive effects of rHDL by demonstrating a reduction in smooth muscle cell (SMC) proliferation and an increase in endothelial cell (EC) proliferation. Additionally, rHDL treatment led to decreased infiltration of leukocytes and downregulated the expression of matrix metallopeptidase 9 (MMP9) in the neointimal area. Notably, rHDL administration resulted in decreased expression of VCAM1 and HIF1α, alongside increased expression of heme oxygenase 1 (HO1) and heat shock protein 27 (HSP27). Overexpression of HSP27 and HO1 effectively inhibited SMC proliferation. Moreover, rHDL-mediated suppression of injury-induced HIF1α coincided with upregulation of HSP27. Interestingly, HSP27 and HO1 had varying effects on the expression of chemokine receptors and rHDL did not exert significant effect on chemokine receptor expression in THP1 cells. These findings underscore the distinct roles of HSP27 and HO1 as potential regulatory factors in the progression of restenosis. Collectively, our study demonstrates that rHDL exerts a potent anti-neointimal hyperplasia effect by reducing leukocytes infiltration and SMC proliferation while promoting EC proliferation.
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Proteínas de Choque Térmico HSP27 , Hemo-Oxigenasa 1 , Animales , Ratas , Células Cultivadas , Proteínas de Choque Térmico HSP27/genética , Hiperplasia , Lipoproteínas HDL/farmacología , Neointima/tratamiento farmacológicoRESUMEN
High-power terahertz radiation was observed to be emitted from a gas jet irradiated by 100-terawatt-class laser pulses in the laser-wakefield acceleration of electrons. The emitted terahertz radiation was characterized in terms of its spectrum, polarization, and energy dependence on the accompanying electron bunch energy and charge under various gas target conditions. With a nitrogen target, more than 4 mJ of energy was produced at <10 THz with a laser-to-terahertz conversion efficiency of ~0.15%. Such strong terahertz radiation is hypothesized to be produced from plasma electrons accelerated by the ponderomotive force of the laser and the plasma wakefields on the time scale of the laser pulse duration and plasma period. This model is examined with analytic calculations and particle-in-cell simulations to better understand the generation mechanism of high-energy terahertz radiation in laser-wakefield acceleration.
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In all-optical Compton scattering driven by a multi-petawatt laser, it is critical to have accurate spatiotemporal synchronization between the ultrarelativistic electron bunch and the ultrahigh-intensity laser beam. Such a synchronization was realized by using two complementary optical setups. The first setup, used for the initial synchronization, recorded the spatial interferogram between the two femtosecond lasers used for a GeV electron beam production and an ultrahigh scattering laser beam. The second one, consisting of spatial and spectral interferometers, measured the time delay between the two laser beams in the range of 0-200 fs in real time. These monitoring systems played an essential role in conducting Compton scattering experiments.
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BACKGROUND: This study aimed to confirm the efficacy of ultrasound-guided adductor canal block (ACB) as a treatment option for medial knee pain caused by knee osteoarthritis (KOA). METHODS: In total, 31 participants with medial knee pain due to KOA were randomized to either the ACB (ultrasound-guided ACB, n = 15) or placebo group (1 mL of 1% lidocaine, n = 16). The primary outcome was a numerical rating scale (NRS) for knee pain intensity comparing before and 4 weeks after injection. The secondary outcomes were the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), average daily number of analgesics consumed, average daily opioid consumption, and Timed Up and Go (TUG) test results before and 4 weeks after injection. RESULTS: Participants' baseline characteristics were not significantly different between the groups, except for age. At 4 weeks post-injection, the NRS score in the ACB group significantly improved compared to that in the placebo group (p = 0.009). However, the WOMAC, average daily number of analgesics consumed, average daily opioid consumption, and TUG test results did not show significant differences. CONCLUSION: ACB can be an effective treatment for reducing medial knee pain in patients with KOA.
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Osteoartritis de la Rodilla , Humanos , Osteoartritis de la Rodilla/complicaciones , Osteoartritis de la Rodilla/tratamiento farmacológico , Método Simple Ciego , Analgésicos Opioides , Articulación de la Rodilla/diagnóstico por imagen , Dolor/complicacionesRESUMEN
BACKGROUND: This study investigated the effects of resistance exercises using elastic bands on stress, lower extremity edema, and body composition in intensive care unit nurses. METHODS: Twenty-three and 21 participants were classified into the experimental and control groups, respectively. Only the experimental group was subjected to a resistance exercise program using elastic bands for 8 weeks. Variables were measured before the experimental treatment and at the 4th and 8th weeks post-treatment. Stress was assessed using a numeric rating scale and stress index. Lower extremity edema was determined using a tape measure. Body composition around the calf and tibia muscle was measured using a body composition analyzer. The homogeneity of participants' general characteristics and the dependent variable was ensured. RESULTS: Following experimental treatment, subjective (Fâ =â 11.674, Pâ <â .001) and objective stresses (Fâ =â 6.965, Pâ <â .001) decreased. No difference was detected in calf and ankle circumference between the groups, while differences in muscle thickness (left, Fâ =â 31.708, Pâ <â .001; right, Fâ =â 18.630, Pâ <â .001) and fat thickness (left, Fâ =â 19.984, Pâ <â .001; right, Fâ =â 24.640, Pâ <â .001) were observed. Muscle thickness increased, and fat thickness decreased in the body composition around the lower extremities. CONCLUSION: Resistance exercises using the TheraBand can be an intervention to decrease stress and improve lower extremity body composition in intensive care unit nurses.
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Entrenamiento de Fuerza , Humanos , Extremidad Inferior , Composición Corporal , Edema/terapia , Unidades de Cuidados Intensivos , Músculo Esquelético/fisiología , Fuerza MuscularRESUMEN
OBJECTIVE: Bilateral frozen shoulder (FS) is often treated with intra-articular corticosteroid injection (IACI). No studies have been performed to establish whether IACI must be administered in both shoulders or in only one shoulder to improve function. This study was therefore performed to determine whether unilateral IACI improves shoulder pain and passive range of motion (pROM) in bilateral FS. METHODS: The medical records of 165 patients with bilateral primary FS who underwent ultrasonography-guided IACI (2 mL of 10-mg/mL triamcinolone acetonide mixed with 5 mL of 1% lidocaine) in one shoulder were retrospectively reviewed. The outcome measures, namely the numeric rating scale (NRS) scores and pROM values (abduction, external rotation, flexion, hyperextension, and internal rotation), were evaluated pre- and post-injection. RESULTS: The patients' mean age was 54.0 ± 8.0 years. The mean symptom duration was 6.5 ± 2.8 months. The mean follow-up period after injection was 6.7 ± 0.8 weeks. The NRS scores and pROM values significantly improved in both the injected and non-injected shoulders. CONCLUSIONS: This study showed that unilateral IACI in patients with bilateral FS improves the clinical outcome of the non-injected shoulder. We suggest that physicians observe the non-injected shoulder after unilateral injection rather than performing bilateral injections.
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Bursitis , Corticoesteroides/uso terapéutico , Bursitis/diagnóstico por imagen , Bursitis/tratamiento farmacológico , Humanos , Inyecciones Intraarticulares , Persona de Mediana Edad , Rango del Movimiento Articular , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Concentrations of 28 novel and legacy perfluoroalkyl and polyfluoroalkyl substances (PFASs) in wastewater from 77 industrial plants in the largest industrial complex in Korea were determined. The industrial plants were of eight types (advanced electronic, battery, chemical, general electronic, glass and ceramic, metal, polymer, and textile). PFAS concentrations in river water receiving the wastewater were determined to assess the impact of wastewater from the industrial complex. Only 19 and nine target PFASs were detected in untreated industrial wastewater and river water, respectively. Novel PFASs such as F53B (6:2 chlorinated polyfluoroalkyl ether sulfonate) were not detected. The mean PFASs concentration in industrial wastewater treatment plant effluent was 5.18 µg/L. The mean total PFASs concentration was highest in advanced electronic plant effluent, second highest in general electronic plant effluent, and lowest in battery and chemical plant effluents. Perfluorohexane sulfonate was the dominant homolog, being detected in effluent from plants of all classes and contributing 96% of total discharged PFASs by mass. Perfluorooctane sulfonate (included in the Stockholm Convention) use has decreased markedly since previous studies. Perfluorooctane sulfonate has largely been replaced by PFASs with fewer than seven carbon atoms. A similar change was found for river water receiving industrial wastewater.
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Ácidos Alcanesulfónicos , Fluorocarburos , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Fluorocarburos/análisis , República de Corea , Ríos , Aguas Residuales/análisis , Agua , Contaminantes Químicos del Agua/análisisRESUMEN
Marine organisms such as fish are at risk of exposure to petrogenic polycyclic aromatic hydrocarbons (PAHs) released in oil spills. PAH toxicities are affected by the rates of PAH biotransformation and elimination in fish tissues, but little information on these rates is available. In this study, the biotransformation and tissue distribution of methylated phenanthrenes-typical petrogenic PAHs found after oil spills-in black rockfish (Sebastes schlegelii) were investigated. Two groups of fish were used. Each fish in one group was given a single intragastric dose of 3-methylphenanthrene, and each fish in the other group was given a single intragastric dose of 3,6-dimethylphenanthrene. The fish were allowed to recover in purified sea water for 196 h. Methylated phenanthrenes were detected in only blood and liver for 24 h after dosing, but the concentrations decreased over time and > 98% had been eliminated by the end of the study. Four mono-hydroxylated metabolites of 3,6-dimethylphenanthrene and six mono-hydroxylated metabolites of 3-methylphenanthrene were tentatively identified for the first time from tandem mass spectrometry analyses of fish bile. The concentrations of these metabolites in bile remained constant for 192 h, suggesting that the metabolites could be used as biomarkers of rockfish exposure to petrogenic PAHs.
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Perciformes , Fenantrenos , Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Animales , Biotransformación , Hidrocarburos Policíclicos Aromáticos/análisisRESUMEN
Per- and polyfluoroalkyl substances (PFAS) concentrations of groundwater in three cities of the Nakdong River Basin in South Korea were quantified to investigate PFAS contamination and the effect of PFAS leakage incident that occurred in the study area in 2018. Groundwater PFASs concentration ranged from non-detectable (N.D.) to 36.9 ng/L (mean 14.1 ng/L), in which, perfluorooctanoic acid (PFOA), perfluorohexanoic acid (PFHxA), perfluoropentanoic acid (PFPeA), and perfluorohexane sulfonate (PFHxS) were commonly observed. Compared to long-chain (C ≥ 8) PFAS, short-chain (Asunto(s)
Ácidos Alcanesulfónicos
, Agua Potable
, Fluorocarburos
, Agua Subterránea
, Contaminantes Químicos del Agua
, Ácidos Alcanesulfónicos/análisis
, Ciudades
, Agua Potable/análisis
, Fluorocarburos/análisis
, República de Corea
, Contaminantes Químicos del Agua/análisis
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The concentrations of 14 perfluoroalkyl substances (PFASs) and 46 pharmaceuticals in raw water and drinking water from five drinking water treatment plants were determined to assess removal of the chemicals during treatment. 10 out of 14 PFASs were detected in the raw and drinking water samples. The mean perfluorohexane sulfonate concentrations in raw and drinking water were the highest with levels of 106 and 69.6 ng L-1, respectively and the other PFAS concentrations were lower. The ∑14PFAS and individual PFAS removal efficiencies for the treatment plants were -36.9% to 70.7% (mean 31.3%) but the granular activated carbon process removed >80% of the total amount of long-chain PFASs that was removed. The removal efficiency increased as the perfluorocarbon chain length increased. The removal efficiencies increased by 14.2% and 11.2% from the shortest to the longest perfluoroalkyl carboxylic acid and perfluoroalkyl sulfonic acid chain lengths, respectively. 20 out of 46 pharmaceuticals were detected in the raw water samples, but most were removed completely during treatment. Only caffeine, carbamazepine, crotamiton, fenbendazole, metformin, and sulfamethoxazole were detected in the drinking water samples. Oxidation processes contributed >90% of the overall treatment plant removal efficiency except for metformin.
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Agua Potable , Fluorocarburos , Preparaciones Farmacéuticas , Contaminantes Químicos del Agua , Purificación del Agua , Monitoreo del Ambiente , Fluorocarburos/análisis , Contaminantes Químicos del Agua/análisisRESUMEN
We demonstrate efficient multicycle terahertz pulse generation at 14.6 THz from large-area lithium niobate crystals by using high-energy (up to 2 J) femtosecond Ti:sapphire laser pulses. Such terahertz radiation is produced by phase-matched optical rectification in lithium niobate. Experimentally, we achieve maximal terahertz energy of 0.71 mJ with conversion efficiency of â¼0.04%. Our experimental setup is simple and easily upscalable to produce multi-millijoule, multicycle terahertz radiation with proper lithium niobate crystals.
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We report multicycle, narrowband, terahertz radiation at 14.8 THz produced by phase-matched optical rectification of femtosecond laser pulses in bulk lithium niobate (LiNbO3) crystals. Our experiment and simulation show that the output terahertz energy greatly enhances when the input laser pulse is highly chirped, contrary to a common optical rectification process. We find this abnormal behavior is attributed to a linear electro-optic (EO) effect, in which the laser pulse propagating in LiNbO3 is modulated by the terahertz field it produces, and this in turn drives optical rectification more effectively to produce the terahertz field. This resonant cascading effect can greatly increase terahertz conversion efficiencies when the input laser pulse is properly pre-chirped with additional third order dispersion. We also observe similar multicycle terahertz emission from lithium tantalate (LiTaO3) at 14 THz and barium borate (BBO) at 7 THz, 10.6 THz, and 14.6 THz, all produced by narrowband phase-matched optical rectification.
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Drug abuse trends in South Korea were assessed by estimating the consumption rates of drugs that may be abused or misused by performing wastewater-based drug epidemiology. Of the 29 target compounds, 10 were found in samples from three wastewater treatment plants. Ephedrine had the highest mean estimated consumption rate, 574.1â¯mgâ¯d-1 (1000 people)-1. The anti-obesity drugs phendimetrazine and phentermine had the second and fifth highest mean estimated consumption rates, 182.9 and 113.1â¯mgâ¯d-1 (1000 people)-1, respectively. The zolpidem consumption rate was 65.8â¯mgâ¯d-1 (1000 people)-1. Methamphetamine was the only illicit drug detected in wastewater, and the estimated consumption rates (14.9-28.6â¯mgâ¯d-1 (1000 people)-1) were similar to consumption rates found in previous Korean studies (not detected to 45.8â¯mgâ¯d-1 (1000 people)-1). The mean estimated meperidine and cis-tramadol (opioid) consumption rates were 120 and 27.5â¯mgâ¯d-1 (1000 people)-1, respectively, and were 8.2 and 1.7 times higher, respectively, than the consumption rates found in 2013. Methylphenidate was detected in the influent and effluent samples at mean concentrations of 2.7 and 2.6â¯ng L-1, respectively, but the methylphenidate consumption rate could not be estimated because of the low excretion rate for humans (<1%).
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Drogas Ilícitas , Trastornos Relacionados con Sustancias , Monitoreo Epidemiológico Basado en Aguas Residuales , Contaminantes Químicos del Agua , Humanos , República de Corea/epidemiología , Trastornos Relacionados con Sustancias/epidemiología , Aguas Residuales/análisis , Contaminantes Químicos del Agua/análisisRESUMEN
We have experimentally demonstrated a simplified method for performing single-shot supercontinuum spectral interferometry (SSSI) that does not require pre-characterization of the probe pulse. The method, originally proposed by D. T. Vu, D. Jang, and K. Y. Kim, uses a genetic algorithm (GA) and as few as two time-delayed pump-probe shots to retrieve the pump-induced phase shift on the probe [Opt. Express26, 20572 (2018)]. We show that the GA is able to successfully retrieve the transient modulations on the probe, and that the error in the retrieved modulation decreases dramatically with the number of shots used. In addition, we propose and demonstrate a practical method that allows SSSI to be done with a single pump-probe shot (again, without the need for pre-characterization of the probe). This simplified method can prove to be immensely useful when performing SSSI with a low-repetition-rate laser source.
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This study investigated the tissue distribution of phenanthrene (PHE) and the formation of monohydroxy-phenanthrene (OH-PHE) metabolites in Korean rockfish (Sebastes schlegelii). PHE was intragastrically administered to two groups of rockfish. The first group was exposed to PHE at a low dose (10 mg/kg body weight) and the second group was exposed at a high dose (30 mg/kg body weight). The rockfish were analyzed and the levels of PHE were higher in the liver, followed by muscle, and then bile. PHE concentrations in the liver, muscle, and bile were 1.4-26, 0.10-2.01, and not detected (ND)-0.13 µg/g wet weight, respectively. All five monohydroxylated PHE metabolites (1-OH-PHE, 2-OH-PHE, 3-OH-PHE, 4-OH-PHE, and 9-OH-PHE) were detected only in bile. Among these OH-PHE metabolites, 3-OH-PHE was found at the highest concentration from all fish bile samples in both PHE exposure groups, indicating that regioselective OH-PHE formation occurs in rockfish and 3-OH PHE could be a good biomarker of exposure of Korean rockfish to PHE. Suspect screening analysis of the rockfish bile was performed by LC-QTOF/MS, and the formation of two OH-PHE-DNA adducts (thymine-OH-PHE and cytosine-OH-PHE) were identified in the bile sample collected 6 h after rockfish were exposed to the high PHE dose, indicating that OH-PHE metabolites may be toxic to fish. This is the first report on the formation characteristics of OH-PHE metabolites in rockfish and their use as biomarkers of exposure of rockfish to parent PHE.
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Perciformes , Fenantrenos , Animales , Aductos de ADN , República de CoreaRESUMEN
We demonstrate high-energy terahertz generation from a large-aperture (75-mm diameter) lithium niobate wafer by using a femtosecond laser with energy up to 2 J. This scheme utilizes optical rectification in a bulk lithium niobate crystal, where most terahertz energy is emitted from a thin layer of the rear surface. Despite its simple setup, this scheme can yield 0.19 mJ of terahertz energy with laser-to-terahertz conversion efficiencies of â¼10-4, about 3 times better than ZnTe when pumped at 800 nm. The experimental setup is upscalable for multimillijoule terahertz generation with petawatt laser pumping.
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We present an experimental study on pressure-dependent terahertz generation from two-color femtosecond laser filamentation in various gases. Contrary to short-focusing geometry, we find that long filamentation yields higher terahertz energy at lower gas pressures in most gases. This counter-intuitive phenomenon occurs due to multiple peculiar properties associated with filamentation. In practice, filamentation in low-pressure argon provides a maximum laser-to-terahertz conversion efficiency of 0.1%, about 10 times higher than in atmospheric air. In addition, our pressure-dependent study reveals an anticorrelation between terahertz output energy and local plasma fluorescence brightness. This determines the absolute phase difference between two-color laser fields for maximal terahertz generation, as well as verifies the microscopic mechanism of terahertz generation in two-color laser mixing.
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This study investigated the occurrence and distribution of 33 pharmaceutical and personal care products (PPCPs), five artificial sweeteners (ASs), and six pesticides in groundwater in rural agricultural and rural non-agricultural area in South Korea. A total of 31 target compounds (15 antibiotics, four anthelmintics, seven other PPCPs, four ASs, and one pesticide) were detected in agricultural groundwater at concentrations from not detected (ND) to 49.3â¯ng/L for PPCPs, ND to 1340â¯ng/L for ASs, and ND to 116â¯ng/L for pesticides. Four target compounds (two PPCPs and two ASs) were detected in rural non-agricultural groundwater in the range of 0.085-5.74â¯ng/L for PPCPs and 5.64-1330â¯ng/L for ASs. Among the target compounds, ASs, especially acesulfame (detection frequency 69% in rural agricultural areas and 100% in the rural non-agricultural area) were predominantly detected in both agricultural (mean: 32.9â¯ng/L) and non-agricultural (mean: 536â¯ng/L) groundwater, but different occurrence patterns were observed according to the sources of contamination. Known markers of sewage leakage were detected in both agricultural and non-agricultural groundwater samples (e.g., acesulfame (69% and 100%), caffeine (88% and 100%), and crotamiton (62% and 100%)), while compounds related to agricultural activities were only observed in agricultural groundwater (e.g., sulfathiazole (38%), sulfamethoxazole (31%), oxfendazole (69%), and carbofuran (42%)).