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1.
Occup Med (Lond) ; 74(2): 152-160, 2024 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-38330390

RESUMO

BACKGROUND: Irregular menstruation is a major health problem among women, although its association with nightshift work remains controversial. AIMS: To study the association between nightshift work and irregular menstrual cycle among female workers and investigate any differences according to sleep quality, working hours or obesity. METHODS: This study included female workers who underwent health examinations from 2012 to 2019. Nightshift work, working hours, sleep quality and menstrual cycles were assessed using self-administered questionnaires. Irregular menstrual cycle was defined as self-reported irregular or ≥36 days. Adjusted odds ratios and 95% confidence intervals (CIs) were calculated by multivariable logistic regression; adjusted hazard ratios (95% CIs) for incident irregular menstrual cycle were calculated by Cox proportional hazard models with time-dependent analysis. RESULTS: The study participants were 87 147 in the cross-sectional study and 41 516 in the longitudinal study. After adjusting for all covariates in the cross-sectional analyses, the odds ratio for prevalent irregular menstrual cycle among female nightshift workers versus the reference was 1.26 (95% CI 1.2-1.33). In the cohort study, the adjusted hazard ratio for incident irregular menstrual cycle among nightshift workers was 1.95 (95% CI 1.61-2.35) in the period after 6 years. No significant differences were observed among subgroups stratified by sleep quality, working hours or obesity. CONCLUSIONS: Nightshift work is associated with an increased risk of both prevalent and incident irregular menstrual cycle in female workers without significant interactions by sleep quality, working hours or obesity.


Assuntos
Ciclo Menstrual , Distúrbios Menstruais , Feminino , Humanos , Seguimentos , Estudos de Coortes , Estudos Transversais , Estudos Longitudinais , Distúrbios Menstruais/etiologia , Distúrbios Menstruais/complicações , Obesidade/epidemiologia , Obesidade/complicações
2.
Nat Nanotechnol ; 18(7): 727-732, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37169897

RESUMO

A series of recent experiments have shown that collision of ballistic electrons in semiconductors can be used to probe the indistinguishability of single-electron wavepackets. Perhaps surprisingly, their Coulomb interaction has not been seen due to screening. Here we show Coulomb-dominated collision of high-energy single electrons in counter-propagating ballistic edge states, probed by measuring partition statistics while adjusting the collision timing. Although some experimental data suggest antibunching behaviour, we show that this is not due to quantum statistics but to strong repulsive Coulomb interactions. This prevents the wavepacket overlap needed for fermionic exchange statistics but suggests new ways to utilize Coulomb interactions: microscopically isolated and time-resolved interactions between ballistic electrons can enable the use of the Coulomb interaction for high-speed sensing or gate operations on flying electron qubits.

3.
Science ; 375(6581): 671-677, 2022 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-35143297

RESUMO

The extension of life span driven by 40% caloric restriction (CR) in rodents causes trade-offs in growth, reproduction, and immune defense that make it difficult to identify therapeutically relevant CR-mimetic targets. We report that about 14% CR for 2 years in healthy humans improved thymopoiesis and was correlated with mobilization of intrathymic ectopic lipid. CR-induced transcriptional reprogramming in adipose tissue implicated pathways regulating mitochondrial bioenergetics, anti-inflammatory responses, and longevity. Expression of the gene Pla2g7 encoding platelet activating factor acetyl hydrolase (PLA2G7) is inhibited in humans undergoing CR. Deletion of Pla2g7 in mice showed decreased thymic lipoatrophy, protection against age-related inflammation, lowered NLRP3 inflammasome activation, and improved metabolic health. Therefore, the reduction of PLA2G7 may mediate the immunometabolic effects of CR and could potentially be harnessed to lower inflammation and extend the health span.


Assuntos
1-Alquil-2-acetilglicerofosfocolina Esterase/genética , Tecido Adiposo/metabolismo , Restrição Calórica , Sistema Imunitário/fisiologia , Inflamação , Timo/imunologia , 1-Alquil-2-acetilglicerofosfocolina Esterase/metabolismo , Adulto , Envelhecimento , Animais , Regulação para Baixo , Metabolismo Energético , Feminino , Humanos , Inflamassomos/metabolismo , Longevidade , Linfopoese , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Termogênese , Timo/anatomia & histologia , Transcriptoma
4.
Nat Commun ; 12(1): 6784, 2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34811372

RESUMO

The control of the in-plane domain evolution in ferroelectric thin films is not only critical to understanding ferroelectric phenomena but also to enabling functional device fabrication. However, in-plane polarized ferroelectric thin films typically exhibit complicated multi-domain states, not desirable for optoelectronic device performance. Here we report a strategy combining interfacial symmetry engineering and anisotropic strain to design single-domain, in-plane polarized ferroelectric BaTiO3 thin films. Theoretical calculations predict the key role of the BaTiO3/PrScO3 [Formula: see text] substrate interfacial environment, where anisotropic strain, monoclinic distortions, and interfacial electrostatic potential stabilize a single-variant spontaneous polarization. A combination of scanning transmission electron microscopy, piezoresponse force microscopy, ferroelectric hysteresis loop measurements, and second harmonic generation measurements directly reveals the stabilization of the in-plane quasi-single-domain polarization state. This work offers design principles for engineering in-plane domains of ferroelectric oxide thin films, which is a prerequisite for high performance optoelectronic devices.

5.
Clin Toxicol (Phila) ; 59(10): 905-912, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33641566

RESUMO

OBJECTIVE: This retrospective study investigated the nature and severity of venom-induced consumption coagulopathy (VICC) and determined the clotting factors involved in VICC in patients after envenomation by South Korea's snakes. Additionally, we studied the effectiveness of antivenom for the treatment of VICC after envenomation. METHODS: Included patients were divided into three groups according to the severity of VICC (no VICC, partial VICC, and complete VICC). Data, including changes in coagulation parameters during hospitalization and clotting factors at presentation, were collected and analyzed. RESULTS: One hundred nineteen patients who presented at our emergency department within 3 h after snake envenomation were included. VICC developed in 34 patients (27 patients with partial VICC and 7 patients with complete VICC). Two of 34 patients with VICC required blood transfusions. Five patients with complete VICC had an undetectable fibrinogen concentration at presentation. Three patients with complete VICC had an unmeasurable INR and aPTT within 24 h. The median times of the most extreme values were 10 h for INR, 12 h for aPTT, and 16 h for fibrinogen after presentation in the VICC group. The D-dimer concentration peaked at a median of 63.5 h after presentation. The activities of factors II and X were significantly reduced in the complete VICC group (factor II: 88 (84-99.3)% in the non-VICC group vs. 69 (49.5-83.5)% in the complete VICC group; factor X:94 (83-102) in the non-VICC group vs. 70 (66.5-79.8)% in the complete VICC group), while there was no difference in factor V activity at presentation. The time from bite to first antivenom administration did not correlate with the time course and most extreme concentrations for fibrinogen and D-dimer within the VICC groups. DISCUSSION AND CONCLUSION: VICC occurs in approximately one-quarter of snakebite patients in South Korea; however, VICC itself does not appear to lead to clinical deterioration. Fibrinogen is an early diagnostic maker for complete VICC. Clotting factors II and X are involved in VICC. Future investigations should explore the mechanism of VICC from Korean snakebites and the effect of antivenom on VICC.


Assuntos
Coagulação Sanguínea , Coagulação Intravascular Disseminada/etiologia , Mordeduras de Serpentes/complicações , Venenos de Serpentes/antagonistas & inibidores , Serpentes , Idoso , Animais , Antivenenos/uso terapêutico , Biomarcadores/sangue , Coagulação Sanguínea/efeitos dos fármacos , Testes de Coagulação Sanguínea , Coagulação Intravascular Disseminada/sangue , Coagulação Intravascular Disseminada/diagnóstico , Coagulação Intravascular Disseminada/tratamento farmacológico , Fator X/metabolismo , Feminino , Fibrinogênio/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Protrombina/metabolismo , República da Coreia , Estudos Retrospectivos , Índice de Gravidade de Doença , Mordeduras de Serpentes/sangue , Mordeduras de Serpentes/diagnóstico , Mordeduras de Serpentes/tratamento farmacológico , Venenos de Serpentes/metabolismo , Fatores de Tempo , Resultado do Tratamento
6.
Epidemiol Psychiatr Sci ; 29: e176, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33077022

RESUMO

AIMS: To investigate the association between parity and the risk of incident dementia in women. METHODS: We pooled baseline and follow-up data for community-dwelling women aged 60 or older from six population-based, prospective cohort studies from four European and two Asian countries. We investigated the association between parity and incident dementia using Cox proportional hazards regression models adjusted for age, educational level, hypertension, diabetes mellitus and cohort, with additional analysis by dementia subtype (Alzheimer dementia (AD) and non-Alzheimer dementia (NAD)). RESULTS: Of 9756 women dementia-free at baseline, 7010 completed one or more follow-up assessments. The mean follow-up duration was 5.4 ± 3.1 years and dementia developed in 550 participants. The number of parities was associated with the risk of incident dementia (hazard ratio (HR) = 1.07, 95% confidence interval (CI) = 1.02-1.13). Grand multiparity (five or more parities) increased the risk of dementia by 30% compared to 1-4 parities (HR = 1.30, 95% CI = 1.02-1.67). The risk of NAD increased by 12% for every parity (HR = 1.12, 95% CI = 1.02-1.23) and by 60% for grand multiparity (HR = 1.60, 95% CI = 1.00-2.55), but the risk of AD was not significantly associated with parity. CONCLUSIONS: Grand multiparity is a significant risk factor for dementia in women. This may have particularly important implications for women in low and middle-income countries where the fertility rate and prevalence of grand multiparity are high.


Assuntos
Doença de Alzheimer/epidemiologia , Demência/epidemiologia , Paridade/fisiologia , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Estudos de Coortes , Europa (Continente)/epidemiologia , Feminino , Psiquiatria Geriátrica , Humanos , Incidência , Vida Independente , Pessoa de Meia-Idade , Gravidez , Modelos de Riscos Proporcionais , República da Coreia/epidemiologia , Fatores de Risco , Fatores Socioeconômicos
7.
Physiol Int ; 107(3): 359-375, 2020 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-32990655

RESUMO

OBJECTIVE: Prior research has evaluated the effects of acute exercise on episodic memory function. These studies have, on occasion, demonstrated that acute exercise may enhance both short- and long-term memory. It is uncertain as to whether the acute exercise improvements in long-term memory are a result of acute exercise attenuating declines in long-term memory, or rather, are driven by the enhancement effects of acute exercise on short-term memory. The present empirical study evaluates whether the decline from short- to long-term is influenced by acute exercise. This relationship is plausible as exercise has been shown to activate neurophysiological pathways (e.g., RAC1) that are involved in the mechanisms of forgetting. METHODS: To evaluate the effects of acute exercise on forgetting, we used data from 12 of our laboratory's prior experiments (N = 538). Across these 12 experiments, acute exercise ranged from 10 to 15 mins in duration (moderate-to-vigorous intensity). Episodic memory was assessed from word-list or paragraph-based assessments. Short-term memory was assessed immediately after encoding, with long-term memory assessed approximately 20-min later. Forgetting was calculated as the difference in short- and long-term memory performance. RESULTS: Acute exercise (vs. seated control) was not associated with an attenuated forgetting effect (d = 0.10; 95% CI: -0.04, 0.25, P = 0.17). We observed no evidence of a significant moderation effect (Q = 6.16, df = 17, P = 0.17, I2 = 0.00) for any of the evaluated parameters, including study design, exercise intensity and delay period. CONCLUSION: Across our 12 experimental studies, acute exercise was not associated with an attenuated forgetting effect. We discuss these implications for future research that evaluates the effects of acute exercise on long-term memory function.


Assuntos
Memória Episódica , Memória de Longo Prazo , Exercício Físico , Memória de Curto Prazo , Projetos de Pesquisa
8.
Phys Rev Lett ; 124(20): 202501, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32501086

RESUMO

We measured missing mass spectrum of the ^{12}C(γ,p) reaction for the first time in coincidence with potential decay products from η^{'} bound nuclei. We tagged an (η+p) pair associated with the η^{'}N→ηN process in a nucleus. After applying kinematical selections to reduce backgrounds, no signal events were observed in the bound-state region. An upper limit of the signal cross section in the opening angle cosθ_{lab}^{ηp}<-0.9 was obtained to be 2.2 nb/sr at the 90% confidence level. It is compared with theoretical cross sections, whose normalization ambiguity is suppressed by measuring a quasifree η^{'} production rate. Our results indicate a small branching fraction of the η^{'}N→ηN process and/or a shallow η^{'}-nucleus potential.

9.
Osteoporos Int ; 31(3): 547-555, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31720711

RESUMO

Thyroid dysfunction is associated with the loss of bone density (osteoporosis). However, the connection between subclinical thyroid dysfunction and osteoporosis remains controversial. This study found no apparent association between subclinical hypothyroidism or subclinical hyperthyroidism and bone mineral density (BMD) in the lumbar spine and femur. INTRODUCTION: The present study examined the relationship between subclinical thyroid dysfunction and BMD in healthy middle-aged adults. METHODS: A total of 25,510 healthy Koreans with normal free thyroxine levels were enrolled from January 2011 to December 2016, and 91% of subjects visited only once. The average age of the 15,761 women was 45, and the average age of the 9749 men was 48. Levels of thyroid-stimulating hormone (TSH) and BMD were recorded in all subjects. BMD was measured using dual-energy X-ray absorptiometry. RESULTS: No apparent association was found between subclinical thyroid dysfunction and BMD in the lumbar spine, femur-neck, and proximal femur sites compared with a euthyroid group. Age, body mass index (BMI), and postmenopausal status affected BMD in women, and only BMI affected BMD in men. Subclinical hypothyroidism was independently associated with a lower risk of osteoporosis (odds ratio 0.657, 95% confidence interval 0.464-0.930) in 4710 postmenopausal women. CONCLUSIONS: No apparent association was found between subclinical hypothyroidism or subclinical hyperthyroidism defined on single TSH measurement and BMD at the lumbar spine and femur in a large cohort of middle-aged men and women. Subclinical hypothyroidism was independently associated with a lower risk of osteoporosis in postmenopausal women.


Assuntos
Densidade Óssea , Osteoporose , Absorciometria de Fóton , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/epidemiologia , Osteoporose/etiologia , República da Coreia/epidemiologia
10.
J Hosp Infect ; 104(4): 476-483, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31785319

RESUMO

BACKGROUND: Concerns are growing over the importance of the hospital water environment for the transmission of carbapenemase-producing Enterobacteriaceae (CPE). AIM: To report a large outbreak in the cardiology units involving intensive care units (ICUs) and wards at a tertiary-care hospital. METHODS: This was a contact tracing, case-control study to find the risk factors for acquisition of CPE and environmental sampling was performed during a CPE outbreak between July and December 2018. FINDINGS: A total of 87 patients with CPE infection or colonization were identified in the cardiology units of the Asan Medical Centre. Diverse organisms were identified containing blakpc, blaNDM-1, blaVIM or blaIMP, blaOXA-48, and co-producing organisms. A case-control study indicated that using the sinks in the ward patient room bathroom for teeth brushing was associated with CPE acquisition (83% vs 30%; P=0.03). The environment was cultured and Klebsiella pneumoniae carbapenemase (KPC)-producing Escherichia coli was isolated from a water dispenser and New Delhi metallo-beta-lactamase (NDM) 1-producing Citrobacter freundii and Enterobacter cloacae from sinks in patient rooms. Pulsed-field gel electrophoresis (PFGE) analysis of KPC-producing E. coli from patients and the water dispenser in ICU and NDM-1-producing E. cloacae from the patient and sink drain showed the same pulsotypes. CONCLUSIONS: The water dispenser and sink drain were suspected as possible reservoirs of CPE in this outbreak. Close contacts with contaminated water such as tooth brushing were identified as risk factors for CPE acquisition. Education for the adequate use of the water environment system as well as the control of the hospital water environment should be implemented to prevent the CPE outbreaks.


Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Infecções por Enterobacteriaceae/etiologia , Infecções por Enterobacteriaceae/microbiologia , Contaminação de Equipamentos , Microbiologia da Água , Idoso , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Cardiologia , Estudos de Casos e Controles , Surtos de Doenças , Enterobacteriaceae , Feminino , Unidades Hospitalares , Hospitais , Humanos , Masculino , Pessoa de Meia-Idade , República da Coreia/epidemiologia , Fatores de Risco , Inquéritos e Questionários
11.
Exp Mech ; 59(9): 1261-1274, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31787777

RESUMO

Growth plate cartilage resides near the ends of long bones and is the primary driver of skeletal growth. During growth, both intrinsically and extrinsically generated mechanical stresses act on chondrocytes in the growth plate. Although the role of mechanical stresses in promoting tissue growth and homeostasis has been strongly demonstrated in articular cartilage of the major skeletal joints, effects of stresses on growth plate cartilage and bone growth are not as well established. Here, we review the literature on mechanobiology in growth plate cartilage at macroscopic and microscopic scales, with particular emphasis on comparison of results obtained using different methodological approaches, as well as from whole animal and in vitro experiments. To answer these questions, macroscopic mechanical stimulators have been developed and applied to study mechanobiology of growth plate cartilage and chondrocytes. However, the previous approaches have tested a limited number of stress conditions, and the mechanobiology of a single chondrocyte has not been well studied due to limitations of the macroscopic mechanical stimulators. We explore how microfluidics devices can overcome these limitations and improve current understanding of growth plate chondrocyte mechanobiology. In particular, microfluidic devices can generate multiple stress conditions in a single platform and enable real-time monitoring of metabolism and cellular behavior using optical microscopy. Systematic characterization of the chondrocytes using microfluidics will enhance our understanding of how to use mechanical stresses to control the bone growth and the properties of tissue-engineered growth plate cartilage.

12.
BMC Neurol ; 19(1): 180, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31370812

RESUMO

BACKGROUND: This study examined how intracranial large artery stenosis (ILAS), symptomatic and asymptomatic ILAS, and risk factors affect unfavorable outcome events after medical treatment in routine clinical practice. METHODS: This was a 24-month prospective observational study of consecutively recruited stroke patients. All participants underwent magnetic resonance angiography, and their clinical characteristics were assessed. Outcome events were vascular outcome, recurrent stroke, and death. Cox regression analyses were performed to identify potential factors associated with an unfavorable outcome, which included demographic and clinical characteristics, the risk factors, and stenosis status. RESULTS: The analysis included 686 patients; among them, 371 were assessed as ILAS negative, 231 as symptomatic ILAS, and 84 as asymptomatic ILAS. Body mass index (p < .05), hypertension (p = .01), and old infarction (p = .047) were factors relating to vascular outcomes. Hypertension was the only factor for recurrent stroke (p = .035). Poor glomerular filtration rate (< 30 mL/min/1.73 m2) (p = .011) and baseline National Institutes of Health Stroke Scale scores (p < .001) were significant predictors of death. CONCLUSIONS: This study extended previous results from clinical trials to a community-based cohort study by concurrently looking at the presence/absence of stenosis and a symptomatic/asymptomatic stenotic artery. Substantiated risk factors rather than the stenosis status were predominant determinants of adverse outcome. Although the degree of stenosis is often an indicator for treatment, we suggest risk factors, such as hypertension and renal dysfunction, should be monitored and intensively treated.


Assuntos
Isquemia Encefálica/complicações , Doenças Arteriais Intracranianas/complicações , Acidente Vascular Cerebral/complicações , Idoso , Artérias/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Isquemia Encefálica/mortalidade , Estudos de Coortes , Constrição Patológica , Feminino , Taxa de Filtração Glomerular , Humanos , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Recidiva , Fatores de Risco , Acidente Vascular Cerebral/mortalidade , Taiwan/epidemiologia
13.
J Dairy Sci ; 102(4): 2844-2853, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30799108

RESUMO

Synbiotics, a combination of prebiotics and probiotics, produce synergistic effects to promote gastrointestinal health. Herein, we investigated the synbiotic interaction between the Lactobacillus rhamnosus strain GG (LGG; a probiotic strain) and tagatose (a prebiotic) in a dextran sulfate sodium (DSS)-induced colitis murine model. Initially, body weight, food intake, and clinical features were dramatically decreased after treatment with DSS, and the addition of LGG, tagatose, or both ameliorated these effects. In our pyrosequencing analysis of fecal microbiota, DSS treatment increased the abundance of Proteobacteria and decreased that of Firmicutes. When LGG and tagatose were administered as synbiotics, the gut microbiota composition recovered from the dysbiosis caused by DSS treatment. In particular, the abundance of Bacteroides, Lactobacillus, and Akkermansia was significantly associated with probiotic, prebiotic, and synbiotic treatments. Taken together, our results suggest that LGG and tagatose as synbiotics can alleviate colitis, and synbiotics could be applied as dietary supplements in dairy foods such as yogurt and cheese.


Assuntos
Colite/induzido quimicamente , Colite/terapia , Hexoses/uso terapêutico , Lacticaseibacillus rhamnosus , Simbióticos , Animais , Sulfato de Dextrana/toxicidade , Fezes/microbiologia , Hexoses/administração & dosagem , Quelantes de Ferro/administração & dosagem , Quelantes de Ferro/farmacologia , Lactobacillus , Lacticaseibacillus rhamnosus/classificação , Camundongos , Microbiota
14.
Eur J Neurol ; 26(3): 553-555, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30103270

RESUMO

BACKGROUND AND PURPOSE: Fabry disease is an X-linked disease, and enzyme-based screening methods are not suitable for female patients. METHODS: In total, 1000 young stroke patients (18-55 years, 661 with ischaemic stroke and 339 with hypertensive intracerebral hemorrhage) were recruited. The Sequenom iPLEX assay was used to detect 26 Fabry related mutation genes. The frequency of Fabry disease in young stroke was reviewed and compared between Asian and non-Asian countries. RESULTS: Two male patients with ischaemic stroke were found to have a genetic mutation of IVS4+919G>A. There was no α-galactosidase A (GLA) gene mutation in female patients. The frequency in Asian stroke patients was 0.62% (male vs. female 0.63% vs. 0.58%) with 0.72% for ischaemic stroke and none for hemorrhagic stroke, compared to 0.88% (0.77% vs. 1.08%) with 0.83% for ischaemic stroke and 1.40% for hemorrhagic stroke reported in western countries. CONCLUSION: IVS4+919G>A is the GLA mutation in Taiwanese young ischaemic stroke patients. Fabry disease is more frequent among non-Asian patients compared to Asian patients.


Assuntos
Isquemia Encefálica/genética , Doença de Fabry/diagnóstico , Doença de Fabry/genética , Testes Genéticos , Acidente Vascular Cerebral/genética , Adolescente , Adulto , Fatores Etários , Isquemia Encefálica/epidemiologia , Doença de Fabry/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/epidemiologia , Taiwan/epidemiologia , Adulto Jovem
15.
Biomicrofluidics ; 12(6): 064101, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30473738

RESUMO

This paper presents micro-particle tracking velocimetry measurements over cultured bovine aortic endothelial cell monolayers in microchannels. The objective was to quantify fluid forces and cell morphology at the sub-cellular scale for monolayers subjected to steady shear rates of 5, 10, and 20 dyn/cm2. The ultimate goal of this study was to develop an experimental methodology for in vitro detailed study of physiologically realistic healthy and diseased conditions. Cell topography, shear stress, and pressure distributions were calculated from sets of velocity fields made in planes parallel to the microchannel wall. For each experiment, measurements were made in 3 h intervals for 18 h. It was found that there is a three-dimensional change in cell morphology as a result of applied shear stress. That is, cells flatten and become more wedge shaped in the stream direction while conserving volume by spreading laterally, i.e., in the cross-stream direction. These changes in cell morphology are directly related to local variations in fluid loading, i.e., shear stress and pressure. This paper describes the first flow measurements over a confluent layer of endothelial cells that are spatially resolved at the sub-cellular scale with a simultaneous temporal resolution to quantify the response of cells to fluid loading.

16.
Phys Rev Lett ; 121(13): 137703, 2018 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-30312059

RESUMO

Using a recent time-of-flight measurement technique with 1 ps time resolution and electron-energy spectroscopy, we develop a method to measure the longitudinal-optical-phonon emission rate of hot electrons traveling along a depleted edge of a quantum Hall bar. Comparison to a single-particle model implies the scattering mechanism involves a two-step process via an intra-Landau-level transition. We show that this can be suppressed by control of the edge potential profile, and a scattering length >1 mm can be achieved, allowing the use of this system for scalable single-electron device applications.

17.
Osteoporos Int ; 29(9): 2011-2020, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30014158

RESUMO

There was a U-shaped association between hip BMD and all-cause mortality, with the lowest mortality in the 90th percentile in males. However, there was an inverse linear relationship in females. In contrast, the association between lumbar spine BMD and mortality was less evident in males, with no association in females. INTRODUCTION: Bone mineral density (BMD) is reported inversely associated with mortality. Although some previous studies provided evidence for nonlinear associations, these were not adequately assessed in most previous works. METHODS: We evaluated the nonlinear relationship between BMD and mortality in Asians. Our study involved 8629 participants in the Dong-gu study from 2007 to 2010. Cox proportional hazard regression was used to calculate hazard ratios (HRs) according to BMD categories after adjusting for potential confounders. During a follow-up of 6.7 ± 1.4 years, 712 participants died. RESULTS: There was a U-shaped association between hip BMD and all-cause mortality, with the lowest mortality in the 90th percentile in males. However, there was an inverse linear relationship in females. In males, compared with the 75th to 95th percentile group, the < 2.5th percentile group had a 3.89 (95% CI 2.41-6.28)-fold higher risk and the 2.5th to 5th percentile group had a 2.51 (95% CI 1.25-5.04)-fold higher risk. The HR was 2.51 (95% CI 1.25, 5.04) in the > 97.5th percentile group. In females, compared with that in the 75th to 95th percentile group, the HR was 2.33 (95% CI 1.24, 4.39) in the < 2.5th percentile group. In contrast, the association between lumbar spine BMD and mortality was less evident in males, with no association in females. CONCLUSION: In conclusion, this study shows that the association between BMD and mortality varies by gender and that high and low BMD are predictors of all-cause mortality in males.


Assuntos
Densidade Óssea/fisiologia , Mortalidade , Absorciometria de Fóton/métodos , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Articulação do Quadril/fisiologia , Humanos , Vértebras Lombares/fisiologia , Masculino , Pessoa de Meia-Idade , Osteoporose/mortalidade , Osteoporose/fisiopatologia , República da Coreia/epidemiologia , Fatores Sexuais
19.
Nutr Metab Cardiovasc Dis ; 28(1): 14-22, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29191476

RESUMO

BACKGROUND AND AIMS: Intracranial arterial stenosis (ICAS) is one of the most common causes of stroke, especially in Asians. Hyperuricemia has been associated with an increased risk of comorbidities such as metabolic syndrome or cardiovascular diseases. However, there are few studies focusing on the association between serum uric acid (SUA) levels and asymptomatic ICAS. The aim of this study was to explore the association between SUA and the prevalence of ICAS in middle-aged Korean health screening examinees. METHODS AND RESULTS: A cross-sectional study was performed on 9417 males and 7755 females who underwent a comprehensive health examination including transcranial Doppler (TCD) ultrasonography. The association of SUA and ICAS was analyzed using multivariate logistic regression. The prevalence of ICAS among the total examinee population was 3.55%. In females, the multivariate-adjusted odds ratio for ICAS was 1.52 (confidence interval 1.13-2.04) in the 3rd quartile of SUA and 1.45 (1.05-2.00) in the highest quartile, compared to the reference (P for trend 0.008). This trend was evident in all clinically relevant subgroups evaluated, including women with low inflammation status. SUA was not significantly associated with the prevalence of ICAS among males. In a sensitivity analysis, the multivariate-adjusted odds ratio of middle cerebral artery stenosis in females was 1.60 (1.09-2.37) in the highest quartile compared to the reference (P for trend 0.023). CONCLUSIONS: Higher SUA level was associated with increased risk of ICAS among middle-aged females but not males. A further cohort study is warranted to elucidate the effect of SUA on asymptomatic ICAS.


Assuntos
Hiperuricemia/sangue , Doenças Arteriais Intracranianas/sangue , Ácido Úrico/sangue , Adulto , Doenças Assintomáticas , Biomarcadores/sangue , Comorbidade , Estudos Transversais , Feminino , Humanos , Hiperuricemia/diagnóstico , Hiperuricemia/epidemiologia , Doenças Arteriais Intracranianas/diagnóstico por imagem , Doenças Arteriais Intracranianas/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , República da Coreia/epidemiologia , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Ultrassonografia Doppler Transcraniana
20.
Andrologia ; 50(3)2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29110315

RESUMO

NAD(P)H-quinone oxidoreductase 1 (NQO1) is a highly inducible flavoprotein known to involve in various cellular defence mechanisms. In this study, we explored whether NQO1 deletion affects hormone-induced prostatic hyperplasia. Testosterone propionate (3 mg/kg, IP) was injected into wild-type (WT) and NOQ1 knockout C57BL/6 mice (NQO1-/- ) for 14 consecutive days, and the samples were collected for biological and histochemical studies. The testosterone-treated NQO1-/- showed about 140% higher prostate weight than the testosterone-treated WT, with enhanced connective tissue and hyperplastic glands formations. However, increased dihydrotestosterone level after testosterone treatment was not significantly different between the WT and NQO1-/- . In contrast, the enhanced nuclear expression of proliferating cell nuclear antigen in NQO1-/- prostate confirmed aggravated prostatic hyperplasia in NQO1-/- . Moreover, the expression of heat shock protein (HSP) 90-α was markedly increased in the NQO1-/- , and this was supported by increased testosterone-induced nuclear androgen receptor expression in NQO1-silenced LNCaP cells. Testosterone-induced prostate-specific antigen expression was not reversed in NOQ1-silenced cells after finasteride treatment. Although the exact role of NQO1 in prostatic hyperplasia remains unclear, the hyperplasia exacerbation due to NQO1 deletion might be independent of type 2 5α-reductase and might be related to enhanced androgen receptor affinity due to enhanced HSP90-α expression.


Assuntos
Di-Hidrotestosterona/sangue , NAD(P)H Desidrogenase (Quinona)/genética , Próstata/metabolismo , Hiperplasia Prostática/genética , Testosterona/sangue , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase/genética , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase/metabolismo , Animais , Linhagem Celular Tumoral , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Masculino , Camundongos , Camundongos Knockout , NAD(P)H Desidrogenase (Quinona)/metabolismo , Próstata/efeitos dos fármacos , Hiperplasia Prostática/induzido quimicamente , Hiperplasia Prostática/metabolismo , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Propionato de Testosterona
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