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1.
ACS Nano ; 17(24): 25101-25117, 2023 Dec 26.
Article in English | MEDLINE | ID: mdl-38052014

ABSTRACT

It is critical to understand the laws of quantum mechanics in transformative technologies for computation and quantum information science applications to enable the ongoing second quantum revolution calls. Recently, spin qubits based on point defects have gained great attention, since these qubits can be initiated, selectively controlled, and read out with high precision at ambient temperature. The major challenge in these systems is controllably generating multiqubit systems while properly coupling the defects. To address this issue, we began by tackling the engineering challenges these systems present and understanding the fundamentals of defects. In this regard, we controllably generate defects in MoS2 and WS2 monolayers and tune their physicochemical properties via proton irradiation. We quantitatively discovered that the proton energy could modulate the defects' density and nature; higher defect densities were seen with lower proton irradiation energies. Three distinct defect types were observed: vacancies, antisites, and adatoms. In particular, the creation and manipulation of antisite defects provides an alternative way to create and pattern spin qubits based on point defects. Our results demonstrate that altering the particle irradiation energy can regulate the formation of defects, which can be utilized to modify the properties of 2D materials and create reliable electronic devices.

2.
Water Res ; 246: 120707, 2023 Nov 01.
Article in English | MEDLINE | ID: mdl-37827038

ABSTRACT

Hydrate-based desalination (HBD) shows promise as a freshwater production technology for saline water. Liquid-phase hydrate formers, with their ability to facilitate hydrate formation at atmospheric pressure, have gained attention for their high energy efficiency in HBD. This study explored cyclopentane (CP) HBD by experimentally measuring the thermodynamic properties of CP hydrate in saline solutions and developing a theoretical framework to estimate the water yield of CP HBD under various operating conditions. The measured dissociation enthalpy of CP hydrate was found to be 12 % and 22 % lower compared to those of propane and R134a hydrates, respectively. The equilibrium dissociation temperatures of CP hydrate at different NaCl concentrations under atmospheric pressure were experimentally measured and then predicted using the Hu-Lee-Sum correlation. The theoretically achievable maximum salinity and water yield for CP HBD were calculated in the temperature range of 268-280 K and the initial salinity range of 0-8 wt.%. Additionally, the concept of HBD heat efficiency, representing the maximum amount of pure water producible per unit of heat, was introduced to identify an optimal operating condition for the HBD process. Efficiency-maximized temperatures, where the HBD heat efficiency reached its peaks, were determined for various initial salinities in the process, for example, 273.4 K for NaCl 3.5 wt.% solution. This novel approach provides invaluable guidance for determining the most energy-efficient operating conditions in the HBD process and establishes a solid foundation for further advancements in this field.


Subject(s)
Cyclopentanes , Sodium Chloride , Temperature , Thermodynamics , Hot Temperature
3.
Sci Rep ; 13(1): 15261, 2023 09 14.
Article in English | MEDLINE | ID: mdl-37709831

ABSTRACT

EWS RNA binding protein 1 (EWSR1) is a multifunctional protein whose epigenetic signatures contribute to the pathogenesis of various human diseases, such as neurodegenerative disorders, skin development, and tumorigenic processes. However, the specific cellular functions and physiological characteristics of EWSR1 remain unclear. In this study, we used quantitative mass spectrometry-based proteomics with tandem mass tag labeling to investigate the global proteome changes in brain tissue in Ewsr1 knockout and wild-type mice. From 9115 identified proteins, we selected 118 differentially expressed proteins, which is common to three quantitative data processing strategies including only protein level normalizations and spectrum-protein level normalization. Bioinformatics analysis of these common differentially expressed proteins revealed that proteins up-regulated in Ewsr1 knockout mouse are mostly related to the positive regulation of bone remodeling and inflammatory response. The down-regulated proteins were associated with the regulation of neurotransmitter levels or amino acid metabolic processes. Collectively, these findings provide insight into the physiological function and pathogenesis of EWSR1 on protein level. Better understanding of EWSR1 and its protein interactions will advance the field of clinical research into neuronal disorders. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD026994.


Subject(s)
Brain , Proteome , Humans , Animals , Mice , RNA-Binding Protein EWS/genetics , Bone Remodeling , Mice, Knockout
4.
Addict Behav ; 141: 107629, 2023 06.
Article in English | MEDLINE | ID: mdl-36746104

ABSTRACT

PURPOSE: This study aimed to use social jetlag to determine how smartphone overuse by adolescents before and after the COVID-19 pandemic might be associated with their circadian rhythm. METHODS: We used 2017 and 2020 Korea Youth Risk Behavior web-based Survey data and conducted a survey analysis on 100,976 adolescents. The dependent variable was abnormal social jetlag. Based on the times recorded by the survey, we calculated the weekday midpoint and weekend sleep time. The main independent variable was smartphone usage time (<2h/day, 2-3.9 h/day, 4-5.9 h/day, and ≥ 6 h/day). Multiple logistic regression and relative excess risk due to interaction (RERI) were performed. RESULTS: Abnormal social jetlag was most prevalent in male and female adolescents who used smartphones ≥ 6 h/day (adjusted odds ratio [AOR] = 2.60, 95 % confidence interval [CI] = 2.47-2.74). The longer the smartphone usage time, the higher the association with abnormal social jetlag. This association was more prominent in female adolescents. The additive interaction between longer smartphone usage time and post-COVID-19 year was statistically significant (total: RERI = 0.92, 95 % CI = 0.90-0.95; males: RERI = 0.83, 95 % CI = 0.80-0.87; females: RERI = 1.13, 95 % CI = 1.08-1.18). CONCLUSION: Our results clearly indicated that increased smartphone usage time tended to result in greater social jetlag, an association that was more pronounced in female. Moreover, the COVID-19 pandemic significantly strengthened this relationship. Further research is needed regarding the proper use of smartphones to ensure good sleep-in adolescents after the COVID-19 pandemic.


Subject(s)
COVID-19 , Smartphone , Humans , Male , Adolescent , Female , Pandemics , Time Factors , Sleep , Jet Lag Syndrome/complications , Surveys and Questionnaires , Republic of Korea
5.
J Affect Disord ; 329: 566-572, 2023 05 15.
Article in English | MEDLINE | ID: mdl-36828144

ABSTRACT

OBJECTIVE: To evaluate the association between pregnancy, lactation after delivery and depressive symptoms in Korean women and to explore the associations according to household composition. METHODS: We included 34,321 premenopausal women from the Korea Community Health Survey in 2019, a population-based cross-sectional study. We categorized the premenopausal women into 3 groups by questions about whether they were currently in menstruation: reference (women who were not pregnant or lactating after delivery), pregnancy, and lactation after delivery. Depressive symptoms (PHQ-9 ≥ 5) were assessed through questionnaires with trained interviewers. Multiple logistic regression analysis were performed. RESULTS: Among 34,321 participants, 20,790 (60.6 %) had depressive symptoms. In the fully adjusted model, we found a significant association between mild depressive symptoms in lactated women after delivery (odds ratio [OR], 95 % confidence interval [CI] = 1.32 [1.04-1.65]) compared to a reference. Compared to reference, the association between women who were lactation after delivery and depressive symptoms was particularly noticeable in women living in families of 2-generation (OR, 95 % CI = 1.29 [1.00-1.65]) and 3-generation (OR, 95 % CI = 2.53 [1.31-4.89]). LIMITATIONS: We utilized self-reported data on pregnancy and lactation after delivery, this exposure variable may be underestimated. CONCLUSION: Our study observed associations between lactated women after delivery and depressive symptoms. This association was more pronounced in women living in 3-generation.


Subject(s)
Depression , Lactation , Female , Pregnancy , Humans , Depression/epidemiology , Cross-Sectional Studies , Surveys and Questionnaires , Self Report , Republic of Korea/epidemiology
6.
Nat Commun ; 13(1): 6477, 2022 Oct 29.
Article in English | MEDLINE | ID: mdl-36309494

ABSTRACT

A tokamak, a torus-shaped nuclear fusion device, needs an electric current in the plasma to produce magnetic field in the poloidal direction for confining fusion plasmas. Plasma current is conventionally generated by electromagnetic induction. However, for a steady-state fusion reactor, minimizing the inductive current is essential to extend the tokamak operating duration. Several non-inductive current drive schemes have been developed for steady-state operations such as radio-frequency waves and neutral beams. However, commercial reactors require minimal use of these external sources to maximize the fusion gain, Q, the ratio of the fusion power to the external power. Apart from these external current drives, a self-generated current, so-called bootstrap current, was predicted theoretically and demonstrated experimentally. Here, we reveal another self-generated current that can exist in a tokamak and this has not yet been discussed by present theories. We report conclusive experimental evidence of this self-generated current observed in the KSTAR tokamak.

7.
J Affect Disord ; 293: 279-284, 2021 10 01.
Article in English | MEDLINE | ID: mdl-34225207

ABSTRACT

BACKGROUND: We aimed to evaluate the association between menstrual cycle irregularity and suicidal ideation in Korean women. METHODS: Data on 5,606 women from the 2010-2012 Korea National Health and Nutrition Examination Survey, a population-based cross-sectional study, were included. Menstrual cycle irregularity, suicidal ideation, current occupational status, age at menarche, education level, household income, and marital status were assessed through questionnaires with trained interviewers. A multivariate logistic regression analysis was performed after adjusting for age, socioeconomic status, smoking and drinking status, age at menarche, comorbid diseases, and physical activity. RESULTS: In the multivariate-adjusted models, we found significant associations between menstrual cycle irregularity and suicidal ideation (odds ratio [OR], 95% confidence interval [CI] = 1.44 [1.14-1.82]). This association was particularly noticeable in women aged 12 to 29 years (OR [95% CI] = 1.45 [1.04-2.03]), in those who had menarche at a relatively early age (aged 8-13 years) (OR [95% CI] = 1.60 [1.15-2.23]), and in those who were currently employed (OR [95% CI] = 1.46 [1.05-2.04]). LIMITATIONS: Suicidal ideation was evaluated based on the participants' self-reports, and were therefore subjective in nature. Additionally, due to the cross-sectional design and use of retrospective data, causal relationships could not be drawn. CONCLUSION: Women with irregular menstrual cycles were 1.42 times more likely to have suicidal ideation than those with regular cycles. More attention should be paid to menstrual cycle irregularity when attempting to improve levels of suicidal ideation.


Subject(s)
Menstrual Cycle , Suicidal Ideation , Adolescent , Child , Cross-Sectional Studies , Female , Humans , Nutrition Surveys , Republic of Korea/epidemiology , Retrospective Studies , Risk Factors
8.
J Psychosom Res ; 148: 110552, 2021 09.
Article in English | MEDLINE | ID: mdl-34171768

ABSTRACT

OBJECTIVE: We aimed to investigate the mental health impact of COVID-19 on a demographically well-characterized population cohort by gender and previous depression status. METHODS: Among people who participated in a community cohort study between 2013 and 2018 with previous depression measurement, a total of 1928 people without quarantine experience (680 men and 1249 women) were included after responding to an online survey in March 2020. In the 2020 survey, people were queried about daily needs supply, social support, risk perception, change during the COVID-19 pandemic, as well as mental health indices measuring loneliness, anxiety symptoms, post-traumatic stress disorder (PTSD), and depression. Separate analyses by gender were conducted to assess the association between COVID-19-related experiences and each mental health index, using multivariable logistic regressions with additional adjustment and stratification with pre-existing depression status. RESULTS: We could not observe significant gender differences for depression, anxiety, PTSD, and loneliness at 55 days after the start of the COVID-19 outbreak. Most external support, including daily needs supply and social support, protected men and women from experiencing severe anxiety (for life supply, OR = 0.92 (95%CI 0.88-0.97) (men) and OR = 0.95 (95% CI 0.91-0.99) (women); for social support, OR = 0.92(both for men and women, p < 0.01)). The results were similar for depression and PTSD. External support showed a larger reduction in the likelihoods for anxiety and depression during the COVID-19 pandemic among people with pre-existing depression compared to previously healthy people, and it was more prominent in men. CONCLUSION: COVID-19 significantly affected the mental health of both men and women in the early period of the pandemic. Having enough supply of daily needs and social support seems important, especially for people with previous depression.


Subject(s)
COVID-19/epidemiology , Depression/epidemiology , Health Surveys , Mental Health/statistics & numerical data , Adult , Aged , Anxiety/epidemiology , Causality , Female , Humans , Male , Middle Aged , Pandemics , Prospective Studies , SARS-CoV-2 , Stress Disorders, Post-Traumatic/epidemiology , Time Factors
9.
J Colloid Interface Sci ; 581(Pt B): 847-859, 2021 Jan 01.
Article in English | MEDLINE | ID: mdl-32818685

ABSTRACT

The development of efficient electrocatalysts for hydrogen generation is an essential task to meet future energy demand. In recent years, molybdenum ditelluride (MoTe2) has triggered incredible research interests due to intrinsic nontrivial band gap with promising semi-metallic behaviors. In this work, 2D MoTe2 nanosheets have been synthesized uniformly on graphene substrate through ultra-fast microwave-initiated approach, that shows a superior hydrogen evolution in acidic medium with low overpotential (~150 mV), low activation energy (8.4362 ± 1.5413 kJ mol-1), along with a Tafel slope of 94.5 mV/decade. Interestingly, MoTe2/graphene exhibits the enhanced electrocatalytic stability during the long cycling test, resulting an increase in specific surface area of catalyst materials. Moreover, the results from periodic plane-wave density functional theory (DFT) indicate that, the best active sites are the corner of a Mo-atom and a critical bifunctional site comprised of adjacent Mo and Te edge atoms. Furthermore, the corresponding volcano plot reveals the near thermoneutral catalytic activity of MoTe2/graphene for hydrogen generation.

10.
J Prosthodont ; 29(2): 185-189, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31919939

ABSTRACT

The articulator is a prerequisite device for the analysis of occlusion and prosthodontic treatment, and it is required to simulate patient jaw movements. This article describes the technique to obtain sagittal condylar inclination (SCI) using cone beam computed tomography (CBCT) data and intraoral scan of the protrusive interocclusal position. The SCI can be used on a virtual articulator in a computer-aided design software, and it can assist in the fabrication of prosthesis which is harmonious with the mandibular movement of individual patient.


Subject(s)
Cone-Beam Computed Tomography , Dental Articulators , Computer-Aided Design , Dental Occlusion , Humans , Imaging, Three-Dimensional , Jaw Relation Record , Mandible , Mandibular Condyle
11.
Twin Res Hum Genet ; 20(3): 226-235, 2017 06.
Article in English | MEDLINE | ID: mdl-28347396

ABSTRACT

Research shows that perceived family cohesion is positively related to prosocial behavior in adolescents. In this study, we investigated heritability of prosocial behavior (PB) and perceived family cohesion (FC) among Nigerian twins attending public schools in Lagos State, Nigeria (mean age = 14.7 years, SD = 1.7 years), and explored the issue of whether children's perception of cohesive family environment moderated genetic and environmental influences on (PB). The PB scale of the Strengths and Difficulties Questionnaire and the FC scale of the Family Adaptability and Cohesion Evaluation Scale III were completed by 2,376 twins (241 monozygotic (MZ) male, 354 MZ female, 440 dizygotic (DZ) male, 553 DZ female, and 788 opposite-sex DZ twins). A general sex-limitation and the bivariate genotype by environment interaction (G×E) models were applied to the data. The general sex-limitation model showed no significant sex differences, indicating that additive genetic and non-shared environmental influences were, 38% (95% CI = 31, 46) and 62% (95% CI = 54, 69) for PB and 33% (95% CI = 24, 40) and 67% (95% CI = 60, 76) for FC in both sexes. These estimates were similar to those found in Western and Asian twin studies to date. The correlation between PB and FC was 0.36. The best-fitting bivariate G×E model indicated that FC significantly moderated non-shared environmental influence unique to PB (E×E interaction). Specifically, non-shared environmental contributions to PB were highest when FC was lowest, and decreased as the levels of FC increased. However, genetic variances in PB were stable across all levels of FC. These findings suggest that FC reduces individual differences in PB by changing non-shared environmental experiences rather than genetic factors in PB.


Subject(s)
Family/psychology , Gene-Environment Interaction , Twins, Dizygotic/genetics , Twins, Monozygotic/genetics , Adolescent , Child , Female , Genotype , Humans , Male , Sex Characteristics , Social Behavior , Twins, Dizygotic/psychology , Twins, Monozygotic/psychology
12.
Langmuir ; 25(1): 410-4, 2009 Jan 06.
Article in English | MEDLINE | ID: mdl-19063617

ABSTRACT

We report the synthesis of Au/CuI and Au/CdS core-shell nanoparticle (NP) thin films using codeposition and electrochemical atomic layer deposition (EC-ALD). Au nanoparticle films were prepared on glassy carbon supports by depositing alternating layers of poly(diallyl dimethylammonium)-stabilized Au nanoparticles and CoP(2)W(17)O(61)(8-) polyoxometallate interlayers. From there, CuI was deposited onto the surface of Au nanoparticles using electrochemical atomic layer deposition, while CdS films were grown by an atom-by-atom codeposition method. The semiconductor-Au core-shell nanoparticles were characterized by electrochemistry, photoluminescence spectroscopy, and Raman spectroscopy. Our results indicate that the semiconductors deposit onto the AuNP surface by surface limited electrochemical reactions.

13.
J Colloid Interface Sci ; 298(2): 713-9, 2006 Jun 15.
Article in English | MEDLINE | ID: mdl-16458916

ABSTRACT

An array of the colloidal photonic crystals was directly fabricated using an ink-jet printing. The colloidal ink droplets containing the monodispersed polystyrene latex particles were selectively deposited on a hydrophobic surface. Solvent evaporation from each ink droplet leads to a formation of microdome-shaped colloidal assembles of close-packed structures. Microspectroscopic analysis has confirmed that the individual assembly serves as a photonic crystal and its optical properties can be correlated with the microstructural features. Unlike other techniques of patterned growth of colloidal photonic crystal, the substrate does not need to be patterned first and no template is needed in the direct writing by the ink-jet printing. Using our strategy, we have rapidly produced the colloidal photonic crystal microarrays composed of different-sized spheres addressably patterned on the same substrate.

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