359 research outputs found

    Through the Spherical Looking-Glass: Asymmetry Enables Multicolored Internal Reflection in Cholesteric Liquid Crystal Shells

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    Spheres of cholesteric liquid crystal generate dynamic patterns due to selec- tive reflection from a helical structure subject to continuously curved bounda- ries. So far the patterns are investigated exclusively as function of reflections at the sphere exterior. Here it is shown that the cholesteric shells in a microfluidics produced double emulsion enable also a sequence of internal reflections if the shells have sufficiently thin top and thick bottom. While such asymmetry is promoted by buoyancy when the internal droplet has lower density than the liquid crystal, the elasticity of the cholesteric helix prefers a symmetric shell geometry, acting against gravity. This subtle balance can hide the internal reflections for long time. Eventually, however, the asymmetry is established, revealing a new class of photonic patterns characterized by colored sharp concentric rings. With the complete knowledge of the diverse light-reflecting behavior of cholesteric liquid crystal shells, and utilizing the tunability of the structure period by, e.g., temperature, electric field, or expo- sure to various chemical species as well as polymer stabilization for making the shells long-term stable, they may be developed into remarkable new optical elements for photonics, sensing, or security pattern generation

    Repression of FLOWERING LOCUS T Chromatin by Functionally Redundant Histone H3 Lysine 4 Demethylases in Arabidopsis

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    FLOWERING LOCUS T (FT) plays a key role as a mobile floral induction signal that initiates the floral transition. Therefore, precise control of FT expression is critical for the reproductive success of flowering plants. Coexistence of bivalent histone H3 lysine 27 trimethylation (H3K27me3) and H3K4me3 marks at the FT locus and the role of H3K27me3 as a strong FT repression mechanism in Arabidopsis have been reported. However, the role of an active mark, H3K4me3, in FT regulation has not been addressed, nor have the components affecting this mark been identified. Mutations in Arabidopsis thaliana Jumonji4 (AtJmj4) and EARLY FLOWERING6 (ELF6), two Arabidopsis genes encoding Jumonji (Jmj) family proteins, caused FT-dependent, additive early flowering correlated with increased expression of FT mRNA and increased H3K4me3 levels within FT chromatin. Purified recombinant AtJmj4 protein possesses specific demethylase activity for mono-, di-, and trimethylated H3K4. Tagged AtJmj4 and ELF6 proteins associate directly with the FT transcription initiation region, a region where the H3K4me3 levels were increased most significantly in the mutants. Thus, our study demonstrates the roles of AtJmj4 and ELF6 as H3K4 demethylases directly repressing FT chromatin and preventing precocious flowering in Arabidopsis

    Explicitly determined sea ice emissivity and emission temperature over the Arctic for surface‐sensitive microwave channels

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    Data assimilation of satellite microwave measurements is one of the importantkeys to improving weather forecasting over the Arctic region. However, the useofsurface-sensitivemicrowave-soundingchannelmeasurementsfordataassim-ilation or retrieval has been limited, especially during winter, due to the poorlyconstrained sea ice emissivity. In this study, aiming at more use of those channelmeasurements in the data assimilation, we propose an explicit method for speci-fying the surface radiative boundary conditions (namely emissivity and emittinglayer temperature of snow and ice). These were explicitly determined with aradiativetransfermodelforsnowandiceandwithsnow/icephysicalparameters(i.e. snow/ice depths and vertical distributions of temperature, density, salinity,and grain size) simulated from the thermodynamically driven snow/ice growthmodel. We conducted 1D-Var experiments in order to examine whether thisapproach can help to use the surface-sensitive microwave temperature channelmeasurements over the Arctic sea ice region for data assimilation. Results showthat (1) the surface-sensitive microwave channels can be used in the 1D-Varretrieval, and (2) the specification of the radiative boundary condition at thesurface using the snow/sea ice emission model can significantly improve theatmospheric temperature retrieval, especially in the lower troposphere (500hPato surface). The successful retrieval suggests that useful information can beextracted from surface-sensitive microwave-sounding channel radiances oversea ice surfaces through the explicit determination of snow/ice emissivity andemitting layer temperature

    Long-Term Use of Oral Corticosteroids and Safety Outcomes for Patients With Atopic Dermatitis

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    Importance: The use of oral corticosteroids for prolonged periods may be associated with adverse events (AEs). Nevertheless, the risk of AEs with oral corticosteroids, especially among patients with atopic dermatitis (AD), has not been comprehensively investigated and lacks evidence on duration of treatment. Objective: To assess the association between long-term exposure to oral corticosteroids and AEs among adult patients with AD. Design, Setting, and Participants: This nested case-control study used data from the Health Insurance Review and Assessment Service database of South Korea between January 1, 2012, and October 31, 2021, which included 1 year prior to the cohort entry date of January 1, 2013, for assessing exclusion criteria and baseline characteristics, and 1 year after the study end date of October 31, 2020, to ensure a minimum duration for assessing exposure. Among the population of adults with AD, patients diagnosed with any of 11 AEs were matched with patients who had never received a diagnosis of any of the 11 AEs. Exposure: Long-term use of oral corticosteroids was defined as cumulative supply of more than 30 days or more than 90 days of oral corticosteroid prescription per year. Main Outcomes and Measures: We used multivariable conditional logistic regression analyses to measure the risk of 11 individual outcomes (osteoporosis, fracture, type 2 diabetes, hyperlipidemia, hypertension, myocardial infarction, stroke, heart failure, avascular necrosis, cataract, or glaucoma) as the composite outcome, controlling for potential confounders. We further classified the composite outcome to individual outcomes to evaluate the AE-specific risk. Results: Among 1025270 patients with AD between 2013 and 2020, 164809 cases (mean [SD] age, 39.4 [14.8]; 56.9% women) were matched with 328303 controls (mean [SD] age, 39.3 [14.7]; 56.9% women) for sex, age, cohort entry date, follow-up duration, and severity of AD, where the balance of most baseline characteristics was achieved. A total of 5533 cases (3.4%) and 10561 controls (3.2%) were exposed to oral corticosteroids for more than 30 days, while 684 cases (0.4%) and 1153 controls (0.4%) were exposed to oral corticosteroids for more than 90 days. Overall, there was no increased risk of AEs with use of oral corticosteroids for more than 30 days (adjusted odds ratio [AOR], 1.00; 95% CI, 0.97-1.04), whereas the risk was slightly higher with use of oral corticosteroids for more than 90 days (AOR, 1.11; 95% CI, 1.01-1.23). The small elevation in experiencing an AE was observed with each cumulative or consecutive year of ever long-term use. Conclusions and Relevance: This case-control study found a slightly increased risk of AEs associated with use of oral corticosteroids for more than 90 days per year, which warrants future research to fully elucidate the observed findings

    Association between Sleep Duration and Injury from Falling among Older Adults:A Cross-Sectional Analysis of Korean Community Health Survey Data

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    Purpose: While sleeping problems increase with advancing age, there are inherent differences in sleep between males and females. Previous studies have shown inconsistent results of the relationship between sleep duration and risk of injury from falling. While controlling various sociodemographic and health-related factors, national representative data were used in order to analyze the association between sleep duration and injury from falling among older adults. Materials and Methods: The data were obtained from the Korean Community Health Survey of 2011. A total of 55654 individuals aged 65 years and older participated in the study. Multivariable logistic regression analysis was conducted to identify the factors associated with injury from falling. Results: After adjusting for covariates, such as age, sex, marital status, whether or not an individual is a recipient of benefits from the National Basic Livelihood Act, hypertension, diabetes mellitus, dyslipidemia, stress level, and self-rated health status, those who slept five hours or less per day [odds ratio (OR)=1.26; 95% confidence interval (CI)=1.18–1.34; p<0.001] or eight hours or more per day (OR=1.11; 95% CI=1.04–1.17; p=0.001) presented significantly higher ORs for injury from falling. A similar result was found when we conducted stratification by sex. Conclusion: The current study supports that there is a relationship between short sleep duration and injury from falling and also identified a marginal risk of long sleep in older adults. Therefore, sleep management in older adults with inadequate sleep duration may be necessary

    Preoperative Magnetic Resonance Imaging Evaluation in Patients with Adolescent Idiopathic Scoliosis

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    Study DesignRetrospective case series.PurposeThe purpose of this study was to examine the incidence of neural axis abnormalities and the relevant risk factors in patients with adolescent idiopathic scoliosis (AIS).Overview of LiteratureThe use of preoperative magnetic resonance imaging (MRI) to assess the whole spine in patients with idiopathic scoliosis is controversial, and indications for such MRI evaluations have not been definitively established. However, we routinely use whole-spine MRI in patients with scoliosis who are scheduled to undergo surgical correction.MethodsA total of 378 consecutive patients with presumed AIS who were admitted for spinal surgery were examined for neural axis abnormalities using MRI. To differentiate patients with normal and abnormal MRI findings, the following clinical parameters were evaluated: age, sex, menarcheal status, rotation angle (using a scoliometer), coronal balance, shoulder height difference, and low back pain. We radiographically evaluated curve type, thoracic or thoracolumbar curve direction, curve magnitude and flexibility, apical vertebral rotation, curve length, coronal balance, sagittal balance, shoulder height difference, thoracic kyphosis, and the Risser sign.ResultsNeural axis abnormalities were detected in 24 patients (6.3%). Abnormal MRI findings were significantly more common in males than in females and were associated with increased thoracic kyphosis. However, there were no significant differences in terms of the other measured parameters.ConclusionsAmong the patients with presumed AIS who received preoperative whole-spine MRI, 6.3% had neural axis abnormalities. Males and patients with increased thoracic kyphosis were at a higher risk

    Factors Related to Self-Confidence to Live Alone in Community-Dwelling Older Adults: A Cross-Sectional Study

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    Background Many older adults prefer to live alone in their own homes, with age-related issues in physical movement, regardless of their cultural background. Importantly, however, to identify the features of successfully ageing in place (AIP), and foster independent living among these individuals, this study explored their level of self-confidence to live alone and its related factors. Methods We conducted a cross-sectional study using secondary data from an earlier study with older adults living alone in South Korea recruited by convenience sampling methods (N = 936, mean age = 77.1 years, 76.1% female). Data regarding the general, health-related, and social characteristics as well as self-confidence to live alone were collected via face-to-face interviews in 2019. Self-confidence to live alone was measured with a numeric rating scale of 0 to 10. Results The average self-confidence score to live alone was 6.59. A regression analysis showed that mould exposure at home, depression, emergency department visits, and loneliness hinder self-confidence to live alone. Meanwhile, such self-confidence was facilitated by independency in instrumental activities of daily living (IADL), interactions with family members, social service utilisation, and social support. Conclusions This study suggests that healthcare providers need to consider the importance of self-confidence to live alone and influencing functional, mental, social, and environmental factors to promote quality of life as well as successful AIP for older adults living alone. Further, self-confidence to live alone could be a new practical index in the field of health and ageing to screen the successful AIP of older adults living alone.This work was supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI18C1284)

    Association of adverse respiratory events with sodium-glucose cotransporter 2 inhibitors versus dipeptidyl peptidase 4 inhibitors among patients with type 2 diabetes in South Korea:a nationwide cohort study

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    BACKGROUND: Impaired respiratory function remains underrecognized in patients with type 2 diabetes (T2D), despite common pulmonary impairment. Meanwhile, there is little data available on the respiratory effects of sodium glucose cotransporter 2 inhibitors (SGLT2i). Hence, we examined the association between SGLT2i use and the risk of adverse respiratory events in a real-world setting. METHODS: We conducted a population-based, nationwide cohort study using an active-comparator new-user design and nationwide claims data of South Korea from January 2015 to December 2020. Among individuals aged 18 years or older, propensity score matching was done to match each new user of SGLT2is with dipeptidyl peptidase 4 inhibitors (DPP4is), with patients followed up according to an as-treated definition. The primary outcome was respiratory events, a composite endpoint of acute pulmonary edema, acute respiratory distress syndrome (ARDS), pneumonia, and respiratory failure. Secondary outcomes were the individual components of the primary outcome and in-hospital death. Cox models were used to estimate hazard ratios (HRs) and 95% CIs. RESULTS: Of 205,534 patient pairs in the propensity score matched cohort, the mean age of the entire cohort was 53.8 years and 59% were men, with a median follow-up of 0.66 years; all baseline covariates achieved balance between the two groups. Incidence rates for overall respiratory events were 4.54 and 7.54 per 1000 person-years among SGLT2i and DPP4i users, respectively, corresponding to a rate difference of 3 less events per 1000 person-years (95% CI - 3.44 to - 2.55). HRs (95% CIs) were 0.60 (0.55 to 0.64) for the composite respiratory endpoint, 0.35 (0.23 to 0.55) for acute pulmonary edema, 0.44 (0.18 to 1.05) for ARDS, 0.61 (0.56 to 0.66) for pneumonia, 0.49 (0.31 to 0.76) for respiratory failure, and 0.46 (0.41 to 0.51) for in-hospital death. Similar trends were found across individual SGLT2is, subgroup analyses of age, sex, history of comorbidities, and a range of sensitivity analyses. CONCLUSIONS: These findings suggest a lower risk of adverse respiratory events associated with patients with T2D initiating SGLT2is versus DPP4is. This real-world evidence helps inform patients, clinicians, and guideline writers regarding the respiratory effects of SGLT2i in routine practice

    Clinically Conserved Genomic Subtypes of Gastric Adenocarcinoma

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    Gastric adenocarcinoma (GAC) is a lethal disease characterized by genomic and clinical heterogeneity. By integrating 8 previously established genomic signatures for GAC subtypes, we identified 6 clinically and molecularly distinct genomic consensus subtypes (CGSs). CGS1 have the poorest prognosis, very high stem cell characteristics, and high IGF1 expression, but low genomic alterations. CGS2 is enriched with canonical epithelial gene expression. CGS3 and CGS4 have high copy number alterations and low immune reactivity. However, CGS3 and CGS4 differ in that CGS3 has high HER2 activation, while CGS4 has high SALL4 and KRAS activation. CGS5 has the high mutation burden and moderately high immune reactivity that are characteristic of microsatellite instable tumors. Most CGS6 tumors are positive for Epstein Barr virus and show extremely high levels of methylation and high immune reactivity. In a systematic analysis of genomic and proteomic data, we estimated the potential response rate of each consensus subtype to standard and experimental treatments such as radiation therapy, targeted therapy, and immunotherapy. Interestingly, CGS3 was significantly associated with a benefit from chemoradiation therapy owing to its high basal level of ferroptosis. In addition, we also identified potential therapeutic targets for each consensus subtype. Thus, the consensus subtypes produced a robust classification and provide for additional characterizations for subtype-based customized interventions
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