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2.
Opt Lett ; 48(3): 607, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36723543

RESUMO

We present a corrigendum to our Letter [Opt. Lett.35, 703 (2010)10.1364/OL.35.000703]. In the original Letter we inadvertently included in Fig. 2(a) a TEM micrograph corresponding to a different, but very similar, sample. This corrigendum replaces Fig. 2(a) with a correct version. Since the main results are rather based in optical absorption measurements, and their modeling by using the T-matrix method, this correction does not affect the results and conclusions of the original Letter.

4.
Nature ; 603(7902): 648-653, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35264798

RESUMO

Birds morph their wing shape to accomplish extraordinary manoeuvres1-4, which are governed by avian-specific equations of motion. Solving these equations requires information about a bird's aerodynamic and inertial characteristics5. Avian flight research to date has focused on resolving aerodynamic features, whereas inertial properties including centre of gravity and moment of inertia are seldom addressed. Here we use an analytical method to determine the inertial characteristics of 22 species across the full range of elbow and wrist flexion and extension. We find that wing morphing allows birds to substantially change their roll and yaw inertia but has a minimal effect on the position of the centre of gravity. With the addition of inertial characteristics, we derived a novel metric of pitch agility and estimated the static pitch stability, revealing that the agility and static margin ranges are reduced as body mass increases. These results provide quantitative evidence that evolution selects for both stable and unstable flight, in contrast to the prevailing narrative that birds are evolving away from stability6. This comprehensive analysis of avian inertial characteristics provides the key features required to establish a theoretical model of avian manoeuvrability.


Assuntos
Voo Animal , Asas de Animais , Animais , Fenômenos Biomecânicos , Aves , Modelos Biológicos , Movimento (Física)
5.
Hong Kong Med J ; 28(4): 315-320, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-33750741

RESUMO

The novel coronavirus disease (COVID-19) may result in acute respiratory distress syndrome and respiratory failure, necessitating mechanical respiratory support. Healthcare professionals are exposed to a particularly high risk of contracting the virus while providing resuscitation and respiratory support, which may in turn result in grave consequences and even death. Although COVID-19 has been shown to cause milder disease in children, paediatricians and intensivists who provide care for children must be prepared to provide optimal respiratory support without putting themselves or other medical, nursing, and paramedical staff at undue risk. We propose an airway management approach that is especially relevant in the current COVID-19 pandemic and provides instructions for: (1) Elective intubation for respiratory failure; and (2) Emergency intubation during cardiopulmonary resuscitation. To minimise risk, intubation methods must be kept as straightforward as possible and should include the provision of appropriate personal protection and equipment to healthcare workers. We identify two key considerations: that bag-mask ventilation should be avoided if possible and that bacterial and viral filters should be placed in the respiratory circuit. Our novel approach provides a framework for airway management that could benefit paediatric critical care practitioners who provide care for any children with a novel viral illness, with a focus on infection prevention during high-risk airway management procedures.


Assuntos
COVID-19 , Insuficiência Respiratória , Manuseio das Vias Aéreas/métodos , Criança , Humanos , Pandemias/prevenção & controle , SARS-CoV-2
6.
J Hosp Infect ; 122: 27-34, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34942201

RESUMO

OBJECTIVES: The first large nosocomial cluster of coronavirus disease 2019 (COVID-19) in Singapore in April 2021 led to partial closure of a major acute care hospital. This study examined factors associated with infection among patients, staff and visitors; investigated the possible role of aerosol-based transmission; evaluated the effectiveness of BNT162.b2 and mRNA1273 vaccines; and described the successful containment of the cluster. METHODS: Close contacts of patients with COVID-19 and the affected ward were identified and underwent surveillance for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Patient, staff and visitor cohorts were constructed and factors associated with infection were evaluated. Phylogenetic analysis of patient samples was performed. Ward air exhaust filters were tested for SARS-CoV-2. RESULTS: In total, there were 47 cases, comprising 29 patients, nine staff, six visitors and three household contacts. All infections were of the Delta variant. Ventilation studies showed turbulent air flow and swabs from air exhaust filters were positive for SARS-CoV-2. Vaccine breakthrough infections were seen in both patients and staff. Among patients, vaccination was associated with a 79% lower odds of infection with COVID-19 (adjusted odds ratio 0.21, 95% confidence interval 0.05-0.95). CONCLUSIONS: This cluster occurred despite enhancement of infection control measures that the hospital had undertaken at the onset of the COVID-19 pandemic. It was brought under control rapidly through case isolation, extensive contact tracing and quarantine measures, and led to enhanced use of hospital personal protective equipment, introduction of routine rostered testing of inpatients and staff, and changes in hospital infrastructure to improve ventilation within general wards.


Assuntos
COVID-19 , Infecção Hospitalar , COVID-19/epidemiologia , COVID-19/prevenção & controle , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/prevenção & controle , Surtos de Doenças , Hospitais , Humanos , Pandemias/prevenção & controle , Filogenia , SARS-CoV-2/genética , Singapura/epidemiologia
7.
Mater Today Adv ; 11: 100148, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34179746

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic had caused a severe depletion of the worldwide supply of N95 respirators. The development of methods to effectively decontaminate N95 respirators while maintaining their integrity is crucial for respirator regeneration and reuse. In this study, we systematically evaluated five respirator decontamination methods using vaporized hydrogen peroxide (VHP) or ultraviolet (254 nm wavelength, UVC) radiation. Through testing the bioburden, filtration, fluid resistance, and fit (shape) of the decontaminated respirators, we found that the decontamination methods using BioQuell VHP, custom VHP container, Steris VHP, and Sterrad VHP effectively inactivated Cardiovirus (3-log10 reduction) and bacteria (6-log10 reduction) without compromising the respirator integrity after 2-15 cycles. Hope UVC system was capable of inactivating Cardiovirus (3-log10 reduction) but exhibited relatively poorer bactericidal activity. These methods are capable of decontaminating 10-1000 respirators per batch with varied decontamination times (10-200 min). Our findings show that N95 respirators treated by the previously mentioned decontamination methods are safe and effective for reuse by industry, laboratories, and hospitals.

11.
Diabet Med ; 37(8): 1308-1315, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32096282

RESUMO

AIM: To assess the associations between demographic and clinical characteristics and sensor glucose metrics in young children with type 1 diabetes, using masked, continuous glucose monitoring data from children aged 2 to < 8 years. RESEARCH DESIGN AND METHODS: The analysis included 143 children across 14 sites in the USA, enrolled in a separate clinical trial. Eligibility criteria were: age 2 to <8 years; type 1 diabetes duration ≥3 months; no continuous glucose monitoring use for past 30 days; and HbA1c concentration 53 to <86 mmol/mol (7.0 to <10.0%). All participants wore masked continuous glucose monitors up to 14 days. RESULTS: On average, participants spent the majority (13 h) of the day in hyperglycaemia (>10.0 mmol/l) and a median of ~1 h/day in hypoglycaemia (<3.9 mmol/l). Participants with minority race/ethnicity and higher parent education levels spent more time in target range, 3.9-10.0 mmol/l, and less time in hyperglycaemia. More time in hypoglycaemia was associated with minority race/ethnicity and younger age at diagnosis. Continuous glucose monitoring metrics were similar in pump and injection users. CONCLUSIONS: Given that both hypo- and hyperglycaemia negatively impact neurocognitive development, strategies to increase time in target glucose range for young children are needed.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Automonitorização da Glicemia , Criança , Pré-Escolar , Feminino , Hemoglobinas Glicadas/metabolismo , Controle Glicêmico , Humanos , Bombas de Infusão Implantáveis , Sistemas de Infusão de Insulina , Masculino , Monitorização Ambulatorial
13.
Sci Rep ; 9(1): 5699, 2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-30952901

RESUMO

An intense photoluminescence emission was observed from noble metal nanoclusters (Pt, Ag or Au) embedded in sapphire plates, nucleated by MeV ion-implantation and assisted by an annealing process. In particular, the spectral photoluminescence characteristics, such as range and peak emission, were compared to the behavior observed from Pt nanoclusters embedded in a silica matrix and excited by UV irradiation. Correlation between emission energy, nanoclusters size and metal composition were analyzed by using the scaling energy relation EFermi/N1/3 from the spherical Jellium model. The metal nanocluster luminescent spectra were numerically simulated and correctly fitted using the bulk Fermi energy for each metal and a Gaussian nanoclusters size distribution for the samples. Our results suggest protoplasmonics photoluminescence from metal nanoclusters free of surface state or strain effects at the nanoclusters-matrix interface that can influence over their optical properties. These metal nanoclusters present very promising optical features such as bright visible photoluminescence and photostability under strong picosecond laser excitations. Besides superlinear photoluminescence from metal nanoclusters were also observed under UV high power excitation showing a quadratic dependence on the pump power fluence.

14.
Diabet Med ; 36(4): 465-472, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30343524

RESUMO

AIM: To test the measurement properties of the revised and updated Pediatric Quality of Life Inventory (PedsQL) 3.2 Diabetes Module originally developed in Type 1 diabetes in youth with Type 2 diabetes. METHODS: The PedsQL 3.2 Diabetes Module and PedsQL Generic Core Scales were administered in a field test study to 100 young people aged 9-25 years with Type 2 diabetes. Factor analysis was conducted to determine the factor structure of the items. RESULTS: The 15-item Diabetes Symptoms Summary Score and 12-item Type 2-specific Diabetes Management Summary Score were empirically derived through factor analysis. The Diabetes Symptoms and Type 2-specific Diabetes Management Summary Scores showed acceptable to excellent reliability across the age groups tested (α = 0.85-0.94). The Diabetes Symptoms and Type 2-specific Diabetes Management Summary Scores evidenced construct validity through large effect size correlations with the Generic Core Scales Total Scale Score (r = 0.67 and 0.57, respectively). HbA1c was correlated with the Diabetes Symptoms and Type 2-specific Diabetes Management Summary Scores (r = -0.13 and -0.22). Minimal clinically important difference (MCID) scores were 5.91 and 7.39 for the Diabetes Symptoms and Type 2-specific Diabetes Management Summary Scores. CONCLUSIONS: The PedsQL 3.2 Diabetes Module Diabetes Symptoms Summary Score and Type 2-specific Diabetes Management Summary Score exhibited satisfactory measurement properties for use as youth self-reported diabetes symptoms and diabetes management outcomes for clinical research and clinical practice for young people with Type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Nível de Saúde , Psicometria/métodos , Qualidade de Vida , Inquéritos e Questionários , Adolescente , Adulto , Fatores Etários , Idade de Início , Criança , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/psicologia , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/psicologia , Estudos de Viabilidade , Feminino , Humanos , Masculino , Medidas de Resultados Relatados pelo Paciente , Reprodutibilidade dos Testes , Inquéritos e Questionários/normas , Adulto Jovem
15.
J Prev Alzheimers Dis ; 5(1): 21-25, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29405228

RESUMO

OBJECTIVE: To examine the association between long-term tea consumption and depressive and anxiety symptoms in community-living elderly. DESIGN: Community based cross-sectional study. SETTING: The Diet and Healthy Aging Study (DaHA), a prospective cohort study in Singapore. PARTICIPANTS: 614 elderly aged 60 years and above, who were free of dementia and cognitive impairment. MEASUREMENTS: Information on tea consumption was obtained through interviewer-administered questionnaire. Long-term tea drinking was defined as regular consumption for at least 15 years. Depressive and anxiety symptoms were measured using the 15-item Geriatric Depression Scale (GDS-15) and the 20-item Geriatric Anxiety Inventory (GAI), respectively. A generalized structural equation model (gSEM) was applied to ascertain the association between long-term tea consumption and depressive and anxiety symptoms. RESULTS: About 59% of the subjects had consumed tea for over 15 years. Long term tea consumption was significantly associated with a reduced odds of having depressive and anxiety symptoms, after adjusting for demographics (i.e., age, gender, education and ethnicity), comorbid conditions (i.e., heart disease, diabetes, stroke, hypertension and hyperlipidaemia) and long-term coffee consumption. CONCLUSION: There was evidence suggesting that long-term tea consumption was associated with reduced depressive and anxiety symptoms among community-living elderly. This suggests that it is worthwhile to further investigate the role of tea's bioactive compounds in promoting mental health in aging.


Assuntos
Ansiedade/prevenção & controle , Depressão/prevenção & controle , Comportamento de Ingestão de Líquido , Chá , Idoso , Estudos Transversais , Avaliação Geriátrica , Envelhecimento Saudável , Humanos , Vida Independente , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Inquéritos e Questionários
16.
Aliment Pharmacol Ther ; 46(10): 1001-1010, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28940673

RESUMO

BACKGROUND: Decompensated liver disease due to portal hypertension leads to significant morbidity and mortality. Statins can modulate intrahepatic vascular tone, but the clinical significance remains uncertain. AIM: To determine the effects of statin use on the risk of liver decompensation and death among patients with chronic viral hepatitis. METHODS: We conducted a population wide cohort study using a hospital based database from the Hong Kong Hospital Authority. Adults with chronic viral hepatitis without prior liver decompensation were identified from 2000 to 2012 by International Classification of Diseases, Ninth Revision, Clinical Modification, diagnostic codes. Statin use was defined as a cumulative defined daily dose of >28. Landmark analysis was used to overcome immortal time bias. Propensity score weighting was further performed to minimise baseline confounders. Primary outcome was a composite of portal hypertension related liver decompensation events, with adjustment for death as a competing risk. RESULTS: A total of 69 184 patients with chronic viral hepatitis (2053 statin users and 67 131 statin non-users) were identified for the 2-year landmark analysis. After propensity score weighting of 23 baseline covariates, statin use was associated with a significant reduction in composite liver decompensation events (HR: 0.55; 95% CI: 0.36-0.83; P = .005), ascites (HR: 0.57; 95% CI: 0.36-0.92; P = .02), and a dose-dependent decrease in death (HR: 0.87; 95% CI: 0.76-0.99; P = .035) relative to no statin use. CONCLUSIONS: Patients with chronic viral hepatitis who used statins have a reduced risk of liver decompensation and death compared to non-users in this propensity score weighted landmark analysis.


Assuntos
Hepatite Crônica/tratamento farmacológico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hepatopatias/tratamento farmacológico , Falência Hepática/prevenção & controle , Adulto , Idoso , Estudos de Coortes , Feminino , Hong Kong , Humanos , Masculino , Pessoa de Meia-Idade , Pontuação de Propensão , Risco , Adulto Jovem
17.
Environ Entomol ; 46(3): 649-653, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28402490

RESUMO

Here, we describe a field experiment that tested for attraction of cerambycid beetles to odors from angiosperm hosts, and whether plant volatiles also serve to enhance attraction of beetles to their aggregation-sex pheromones. Traps were baited with a blend of synthesized chemicals that are common pheromone components of species in the subfamilies Cerambycinae and Lamiinae. The source of plant volatiles was chipped wood from trees of three angiosperm species, as well as from one nonhost, gymnosperm species. Bioassays were conducted in wooded areas of east-central Illinois. Traps were baited with the pheromone blend alone, the blend + wood chips from one tree species, wood chips alone, or a solvent control lure. Seven species of cerambycids were significantly attracted to the pheromone blend, with or without wood chips. In two cases, wood chips from angiosperms appeared to enhance attraction to pheromones, whereas they inhibited attraction in another three cases. Pine chips did not strongly influence attraction of any species. Overall, our results suggest that host plant volatiles from wood chips may improve trap catch with synthesized pheromones for some cerambycid species, but the effect is not general, necessitating case-by-case testing to determine how individual target species are affected.


Assuntos
Quimiotaxia , Besouros/fisiologia , Cadeia Alimentar , Odorantes/análise , Atrativos Sexuais/farmacologia , Animais , Besouros/crescimento & desenvolvimento , Comportamento Alimentar , Feminino , Fraxinus/química , Illinois , Larva/fisiologia , Masculino , Quercus/química , Salix/química
18.
J Nutr Health Aging ; 20(4): 404-7, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26999240

RESUMO

OBJECTIVE: Our aim of this study was to investigate the association between fish consumption and depressive symptoms in senior ethnic Chinese residents of Singapore. DESIGN: A population-based cross-sectional study. SETTING: The Singapore Longitudinal Aging Studies (SLAS). PARTICIPANT: The study consisted of 2,034 participants from the Singapore Longitudinal Aging Studies (SLAS) project who were at least 55 years old. MEASUREMENTS: The presence of depressive symptoms was compared between those who self-reported eating fish at least three times a week versus those who ate fish less often. A score of 5 or greater on the 15-item Geriatric Depression Scale (GDS-15) was the cutoff for being designated as having depressive symptoms. RESULTS: Fish intake was associated with a lower prevalence of depressive symptoms ([odds ratio] OR = 0.60, 95% [confidence interval] CI 0.40-0.90; P = .015) after controlling for age, sex, marital status, housing, smoking, alcohol consumption, physical exercise, social and productive activities, self-rated health, hypertension, diabetes, heart failure or attack, stroke, fruit and vegetable intake, and Mini-Mental State Examination (MMSE) scores. CONCLUSION: Our results suggest that eating fish at least three times a week is associated with a lower odds of having depressive symptoms among Chinese adults over 55 years old living in Singapore.


Assuntos
Envelhecimento , Povo Asiático , Depressão/epidemiologia , Depressão/psicologia , Dieta/estatística & dados numéricos , Peixes , Idoso , Animais , China/etnologia , Estudos Transversais , Depressão/dietoterapia , Depressão/prevenção & controle , Feminino , Avaliação Geriátrica , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Fatores de Risco , Autorrelato , Singapura/epidemiologia
19.
Eur J Neurol ; 23(2): 382-6, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26435298

RESUMO

BACKGROUND AND PURPOSE: Our aim was to provide estimates of traumatic brain injury (TBI) in 2050 for the African population by region, sex and age strata. METHODS: A literature search was performed in October 2014 in PubMed for population-based studies of TBI in different geographical locations. Articles were selected from Kenya (model 1), New Zealand (model 2) and the USA (model 3). In model 1, rates of road traffic injury in Kenya were used to estimate TBI rates in the African continent. Models 2 and 3 used existing TBI incidence estimates from other locations to estimate the burden of TBI for Africa in 2050. The 2050 African population, as projected by the United Nations, was used as a base population. RESULTS: Based on rates from model 1, the estimated total TBI count in Africa in 2050 is 5.98 ± 0.03 million, with the highest count in eastern (2.04 ± 0.01 million) and lowest count in southern (0.15 ± 0.00 million) Africa. A higher TBI count is predicted by models 2 (14.25 ± 0.75 million) and 3 (10.40 ± 0.02 million). Estimated TBI count is highest for males aged 15-34 (5.47 ± 0.55 million in model 2 and 3.21 ± 0.13 million in model 3). CONCLUSIONS: Projected estimates of TBI in Africa are high, with a burden of anywhere between approximately 6 and 14 million new cases in 2050. This emphasizes the importance of developing accurate surveillance systems of TBI at a population level and public health measures to mitigate the risk and burden of TBI.


Assuntos
Lesões Encefálicas/epidemiologia , Adolescente , Adulto , África/epidemiologia , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Fatores Sexuais , Adulto Jovem
20.
Brain Res ; 1574: 96-104, 2014 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-24928620

RESUMO

Deferoxamine (DFO) has shown therapeutic promise for the treatment of Parkinson׳s disease (PD) as it has reduced both behavioral and biochemical deficits when injected into the brain of rodent models of PD. Intranasally administered DFO targets the brain directly but non-invasively and has been effective in animal models of stroke and Alzheimer׳s disease. In this study we sought to determine whether intranasal (IN) DFO could be neuroprotective for PD in a rat model. PD was induced with a unilateral injection of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle, while sham surgery rats received saline injections. Rats were pre-treated three times with either IN DFO or saline (starting 4 days before 6-OHDA), and post-treated twice/wk for one month before behavioral tests. In the apomorphine-induced rotational test, IN DFO significantly decreased the number of contralateral turns after injection of apomorphine HCl (p<0.05). Also, IN DFO significantly decreased limb asymmetry in the rearing tube as measured with contralateral limb touches (p<0.05). The IN DFO treatment yielded a trend towards decreased contralateral foot-slips on the tapered balance beam, though the difference was not significant. Finally, IN DFO-treated rats had increased preservation of tyrosine hydroxylase immunoreactive neurons in the substantia nigra (p<0.05). These results confirm that DFO is beneficial in a 6-OHDA model and demonstrate improvement in motor deficits and dopaminergic neuronal survival with non-invasive intranasal delivery, making this an attractive potential treatment for PD.


Assuntos
Antiparkinsonianos/administração & dosagem , Desferroxamina/administração & dosagem , Transtornos Parkinsonianos/tratamento farmacológico , Administração Intranasal , Animais , Apomorfina/farmacologia , Agonistas de Dopamina/farmacologia , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/patologia , Neurônios Dopaminérgicos/fisiologia , Lateralidade Funcional , Masculino , Feixe Prosencefálico Mediano/fisiopatologia , Atividade Motora/efeitos dos fármacos , Oxidopamina , Transtornos Parkinsonianos/patologia , Transtornos Parkinsonianos/fisiopatologia , Fotomicrografia , Ratos Long-Evans , Substância Negra/efeitos dos fármacos , Substância Negra/patologia , Substância Negra/fisiopatologia , Tirosina 3-Mono-Oxigenase/metabolismo
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