4,441 research outputs found

    The mechanism of the polarization dependence of the optical transmission in subwavelength metal hole arrays

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    We investigate the mechanism of extraordinary optical transmission in subwave-length metal hole arrays. Experimental results for the arrays consisting of square or rectangle holes are well explained about the dependence of transmission strength on the polarization direction of the incident light. This polarization dependence occurs in each single-hole. For a hole array, there is in addition an interplay between the adjacent holes which is caused by the transverse magnetic field of surface plasmon polariton on the metal film surfaces. Based on the detailed study of a single-hole and two-hole structures, a simple method to calculate the total tranmissivity of hole arrays is proposed.Comment: 34 pages, 7 figure

    Factors associated with the introduction of prelacteal feeds in Nepal: findings from the Nepal Demographic and Health Survey 2011

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    Background: A prelacteal feed is any food except mother’s milk provided to a newborn before initiating breastfeeding. Prelacteal feeding is a major barrier to exclusive breastfeeding. It is a prevalent practice in Nepal. Little is known about the factors associated with providing prelacteal feeds to the Nepalese newborn. This study explored the factors associated with providing prelacteal feeds to children under three years in Nepal using the Nepal Demographic and Health Survey (NDHS) 2011. Methods: This study utilised the NDHS 2011 child dataset which is a nationally representative study. The rates of providing prelacteal feeds were reported as a proportion. Complex Sample Analysis method was used to account for the cluster design and sample weight of the study. Chi-square tests and multiple logistic regression were used to analyse the factors associated with providing prelacteal feeds.Results: A sample of 3948 mothers were included in the study. A total of 841 [26.5% (95% CI: 23.1%–30.3%)] weighted proportion) of mothers reported of providing prelacteal feeds to their newborn infants. Plain water (n = 75), sugar/glucose (n = 35), gripe water (n = 3), sugar/salt solution (n = 3), fruit juice (n = 3), infant formula (n = 96), tea (n = 3) and other milk other than breast milk (n = 556) were some of the types of prelacteal feeds reported. The multiple regression analysis showed that the mothers who had no education, were not working, were from the middle wealth quintile, who had not attended four antenatal care visits, were first time mothers and who were from the Terai/Plain region were more likely to provide prelacteal feeds. Conclusions: Given that one in four infants were provided with prelacteal feeds, there is a need to implement breastfeeding promotion programs to increase the practice of exclusive breastfeeding and reduce prelacteal feeding practices. Breastfeeding counseling at antenatal clinics and peer support for exclusive breastfeeding should be included as part of breastfeeding promotion programs. Mobilisation of female community health volunteers for peer counseling is also a feasible option for Nepal

    Association of PET-measured myocardial flow reserve with echocardiography-estimated pulmonary artery systolic pressure in patients with hypertrophic cardiomyopathy

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    BackgroundPulmonary hypertension (PH) is a known complication of HCM and is a strong predictor of mortality. We aim to investigate the relationship between microvascular dysfunction measured by quantitative PET and PH in HCM patients.MethodsEighty-nine symptomatic HCM patients were included in the study. Each patient underwent two 20-min 13N-NH3 dynamic PET scans for rest and stress conditions, respectively. A 2-tissue irreversible compartmental model was used to fit the segments time activity curves for estimating segmental and global myocardial blood flow (MBF) and myocardial flow reserve (MFR). Echocardiographic derived PASP was utilized to estimate PH.ResultsPatients were categorized into two groups across PASP: PH (PASP > 36 mmHg) and no-PH (PASP ≤ 36 mmHg). patients with PH had larger left atrium, ratio of higher inflow early diastole (E) and atrial contraction (A) waves, E/A, and ratio of inflow and peak early diastolic waves, E/e', significantly reduced global stress MBF (1.85 ± 0.52 vs. 2.13 ± 0.56 ml/min/g; p = 0.024) and MFR (2.21 ± 0.57 vs. 2.62 ± 0.75; p = 0.005), while the MBFs at rest between the two groups were similar. There were significant negative correlations between global stress MBF/MFR and PASP (stress MBF: r = -0.23, p = 0.03; MFR: r = -0.32, p = 0.002); for regional MBF and MFR measurements, the highest linear correlation coefficients were observed in the septal wall (stress MBF: r = -0.27, p = 0.01; MFR: r = -0.31, p = 0.003). Global MFR was identified to be independent predictor for PH in multivariate regression analysis.ConclusionEchocardiography-derived PASP is negatively correlated with global MFR measured by 13N-NH3 dynamic PET. Global MFR is suggested to be an index of PH in HCM patients.</div

    The multi-level governance of formulating regional brand identities: Evidence from three Mega City Regions in China

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    The emergence and expansion of clusters of large metropolitan areas also known as Mega City Regions (MCRs) is a worldwide phenomenon. In China, governmental attempts are made to develop so-called regional brand identities for them. Regional brand identities, as a subspecies of place brand identities, differ from regional identities in the sense that they are the result of conscious branding efforts on the part of public authorities rather than more historically evolved regional identities as experienced by citizens. In this study, the establishment of regional brand identities for three MCRs in China is examined, as these are constituted through and institutionally embedded in intergovernmental relations. We map the perceptions of national, provincial and municipal governments of regional brand identities based on planning documents and relevant interviews. The emergence and stabilization of the regional profiles for China's largest MCRs Pearl River Delta (PRD), Yangtze River Delta (YRD) and Jing-Jin-Ji (JJJ) are featured in their dynamic territorial boundaries, centralized institutionalization and various symbolic meanings. The national government promotes the regional brands to reinforce the strategic awareness and future direction of the region, and these profiles are diffused at the provincial and municipal level

    Synchronous nanoscale topographic and chemical mapping by differential-confocal controlled Raman microscopy

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    Confocal Raman microscopy is currently used for label-free optical sensing and imaging within the biological, engineering, and physical sciences as well as in industry. However, currently these methods have limitations, including their low spatial resolution and poor focus stability, that restrict the breadth of new applications. This paper now introduces differential-confocal controlled Raman microscopy as a technique that fuses differential confocal microscopy and Raman spectroscopy, enabling the point-to-point collection of three-dimensional nanoscale topographic information with the simultaneous reconstruction of corresponding chemical information. The microscope collects the scattered Raman light together with the Rayleigh light, both as Rayleigh scattered and reflected light (these are normally filtered out in conventional confocal Raman systems). Inherent in the design of the instrument is a significant improvement in the axial focusing resolution of topographical features in the image (to ∼1 nm ), which, when coupled with super-resolution image restoration, gives a lateral resolution of 220 nm. By using differential confocal imaging for controlling the Raman imaging, the system presents a significant enhancement of the focusing and measurement accuracy, precision, and stability (with an antidrift capability), mitigating against both thermal and vibrational artefacts. We also demonstrate an improved scan speed, arising as a consequence of the nonaxial scanning mode

    The macro-behavior of agents' opinion under the influence of an external field

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    In this paper, a model about the evolution of opinion on small world networks is proposed. We studied the macro-behavior of the agents' opinion and the relative change rate as time elapses. The external field was found to play an important role in making the opinion s(t)s(t) balance or increase, and without the influence of the external field, the relative change rate γ(t)\gamma(t) shows a nonlinear increasing behavior as time runs. What's more, this nonlinear increasing behavior is independent of the initial condition, the strength of the external field and the time that we cancel the external field. Maybe the results can reflect some phenomenon in our society, such as the function of the macro-control in China or the Mass Media in our society.Comment: 8 pages, 3 figure

    Residential indoor exposure to fine and ultrafine particulate air pollution in association with blood pressure and subclinical central haemodynamic markers of cardiovascular risk among healthy adults living in Perth, Western Australia

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    Despite that large percentages of individual daily time is spent in the home, few studies have examined the relationship between indoor particulate matter (PM) exposure in residential settings with subclinical indicators of cardiovascular risk. This cross-sectional study investigated associations between exposure to fine (PM2.5) and ultrafine (UFP) PM in domestic indoor environments, with central blood pressure (BP) and component BP measures (pulse pressure, augmented pressure [AP], augmentation index [AIx], mean arterial pressure, pulse wave velocity [PWV]) in 40 non-smoking, otherwise healthy adults (58% women) living in Perth, Western Australia. Overall, in adjusted models, an interquartile range (IQR) increase in PM2.5 was associated with a 3.2 mmHg (95% confidence interval [CI]: 0.99, 5.45) higher diastolic BP, and a 1.8 mmHg lower AP (95%CI: − 3.63, − 0.01) and 0.4 m/s PWV (95%CI: − 0.80, − 0.08), respectively. For the UFP fraction, an IQR increase was associated with a 5.2% higher AIx (95%CI: 0.51, 9.97) and a 0.6 m/s lower PWV (95%CI: − 1.00, − 0.11). When stratified by sex, higher UFP concentrations were associated with higher DBP and lower PWV among women. Among men, higher UFP concentrations were associated with lower AP. Exposure to domestic indoor fine and ultrafine PM was associated with preclinical indicators of cardiovascular risk and some of these relationships were affected by sex. These findings contribute important evidence linking low-level residential indoor PM exposure with measurable impacts on cardiovascular physiology and may inform preventative recommendations as part of risk profiles for susceptible individuals
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