The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
P G Etchegoin - One of the best experts on this subject based on the ideXlab platform.
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Phenomenological local field enhancement Factor Distributions around electromagnetic hot spots.
The Journal of chemical physics, 2009Co-Authors: P G EtchegoinAbstract:We propose a general phenomenological description of the enhancement Factor Distribution for surface-enhanced Raman scattering (SERS) and other related phenomena exploiting large local field enhancements at hot spots. This description extends naturally the particular case of a single (fixed) hot spot, and it is expected to be “universal” for many classes of common SERS substrates containing a collection of electromagnetic hot spots with varying geometrical parameters. We further justify it from calculations with generalized Mie theory. The description studied here provides a useful starting point for a qualitative (and semiquantitative) understanding of experimental data and, in particular, the analysis of the statistics of single-molecule SERS events.
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enhancement Factor Distribution around a single surface enhanced raman scattering hot spot and its relation to single molecule detection
Journal of Chemical Physics, 2006Co-Authors: P G Etchegoin, Matthias MeyerAbstract:We provide the theoretical framework to understand the phenomenology and statistics of single molecule (SM) signals arising in surface enhanced Raman scattering (SERS) under the presence of so-called electromagnetic hot spots. We show that most characteristics of the SM-SERS phenomenon can be tracked down to the presence of a tail-like (power law) Distribution of enhancements and we propose a specific model for it. We analyze, in the light of this, the phenomenology of SM-SERS and show how the different experimental manifestations of the effect reported in the literature can be analyzed and understood under a unified "universal" framework with a minimum set of parameters.
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enhancement Factor Distribution around a single sers hot spot and its relation to single molecule detection
arXiv: Chemical Physics, 2006Co-Authors: P G Etchegoin, Matthias MeyerAbstract:We provide the theoretical framework to understand the phenomenology and statistics of single-molecule (SM) signals arising in Surface-Enhanced Raman Scattering (SERS) under the presence of so-called electromagnetic hot-spots (HS's). We show that most characteristics of the SM-SERS phenomenon can be tracked down to the presence of tail-like (power law) Distribution of enhancements and we propose a specific model for it. We analyze, in the light of this, the phenomenology of SM-SERS and show how the different experimental manifestations of the effect reported in the literature can be analyzed and understood under a unified ``universal'' framework with a minimum set of parameters.
Ramya Walsan - One of the best experts on this subject based on the ideXlab platform.
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geographic and area level socioeconomic variation in cardiometabolic risk Factor Distribution a systematic review of the literature
International Journal of Health Geographics, 2019Co-Authors: Renin Toms, Andrew D Bonney, Darren J Mayne, Xiaoqi Feng, Ramya WalsanAbstract:A growing number of publications report variation in the Distribution of cardiometabolic risk Factors (CMRFs) at different geographic scales. A review of these variations may help inform policy and health service organisation. To review studies reporting variation in the geographic Distribution of CMRFs and its association with various proxy measures of area-level socioeconomic disadvantage (ASED) among the adult ( ≥ 18 years) population across the world. A systematic search for published articles was conducted in four databases (MEDLINE (Ovid), PubMed, Scopus and Web of Science) considering the interdisciplinary nature of the review question. Population-based cross-sectional and cohort studies on geographic variations of one or more biological proxies of CMRFs with/without an analysed contextual association with ASED were included. Two independent reviewers screened the studies and PRISMA guidelines were followed in the study selection and reporting. A total of 265 studies were retrieved and screened, resulting in 24 eligible studies. The review revealed reports of variation in the Distribution of CMRFs, at varying geographic scales, in multiple countries. In addition, consistent associations between ASED and higher prevalence of CMRFs were demonstrated. The reports were mainly from industrialised nations and small area geographic units were frequently used. Geographic variation in cardiometabolic risk exists across multiple spatial scales and is positively associated with ASED. This association is independent of individual-level Factors and provides an imperative for area-based approaches to informing policy and health service organisation. The study protocol is registered in International prospective register of systematic reviews (Register No: CRD42018115294) PROSPERO 2018.
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Geographic and area-level socioeconomic variation in cardiometabolic risk Factor Distribution: a systematic review of the literature
International Journal of Health Geographics, 2019Co-Authors: Renin Toms, Ramya Walsan, Andrew Bonney, Darren J Mayne, Xiaoqi FengAbstract:Introduction A growing number of publications report variation in the Distribution of cardiometabolic risk Factors (CMRFs) at different geographic scales. A review of these variations may help inform policy and health service organisation. Aim To review studies reporting variation in the geographic Distribution of CMRFs and its association with various proxy measures of area-level socioeconomic disadvantage (ASED) among the adult ( ≥ 18 years) population across the world. Methods A systematic search for published articles was conducted in four databases (MEDLINE (Ovid), PubMed, Scopus and Web of Science) considering the interdisciplinary nature of the review question. Population-based cross-sectional and cohort studies on geographic variations of one or more biological proxies of CMRFs with/without an analysed contextual association with ASED were included. Two independent reviewers screened the studies and PRISMA guidelines were followed in the study selection and reporting. Result A total of 265 studies were retrieved and screened, resulting in 24 eligible studies. The review revealed reports of variation in the Distribution of CMRFs, at varying geographic scales, in multiple countries. In addition, consistent associations between ASED and higher prevalence of CMRFs were demonstrated. The reports were mainly from industrialised nations and small area geographic units were frequently used. Conclusion Geographic variation in cardiometabolic risk exists across multiple spatial scales and is positively associated with ASED. This association is independent of individual-level Factors and provides an imperative for area-based approaches to informing policy and health service organisation. The study protocol is registered in International prospective register of systematic reviews (Register No: CRD42018115294) PROSPERO 2018.
Xiaoqi Feng - One of the best experts on this subject based on the ideXlab platform.
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geographic and area level socioeconomic variation in cardiometabolic risk Factor Distribution a systematic review of the literature
International Journal of Health Geographics, 2019Co-Authors: Renin Toms, Andrew D Bonney, Darren J Mayne, Xiaoqi Feng, Ramya WalsanAbstract:A growing number of publications report variation in the Distribution of cardiometabolic risk Factors (CMRFs) at different geographic scales. A review of these variations may help inform policy and health service organisation. To review studies reporting variation in the geographic Distribution of CMRFs and its association with various proxy measures of area-level socioeconomic disadvantage (ASED) among the adult ( ≥ 18 years) population across the world. A systematic search for published articles was conducted in four databases (MEDLINE (Ovid), PubMed, Scopus and Web of Science) considering the interdisciplinary nature of the review question. Population-based cross-sectional and cohort studies on geographic variations of one or more biological proxies of CMRFs with/without an analysed contextual association with ASED were included. Two independent reviewers screened the studies and PRISMA guidelines were followed in the study selection and reporting. A total of 265 studies were retrieved and screened, resulting in 24 eligible studies. The review revealed reports of variation in the Distribution of CMRFs, at varying geographic scales, in multiple countries. In addition, consistent associations between ASED and higher prevalence of CMRFs were demonstrated. The reports were mainly from industrialised nations and small area geographic units were frequently used. Geographic variation in cardiometabolic risk exists across multiple spatial scales and is positively associated with ASED. This association is independent of individual-level Factors and provides an imperative for area-based approaches to informing policy and health service organisation. The study protocol is registered in International prospective register of systematic reviews (Register No: CRD42018115294) PROSPERO 2018.
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Geographic and area-level socioeconomic variation in cardiometabolic risk Factor Distribution: a systematic review of the literature
International Journal of Health Geographics, 2019Co-Authors: Renin Toms, Ramya Walsan, Andrew Bonney, Darren J Mayne, Xiaoqi FengAbstract:Introduction A growing number of publications report variation in the Distribution of cardiometabolic risk Factors (CMRFs) at different geographic scales. A review of these variations may help inform policy and health service organisation. Aim To review studies reporting variation in the geographic Distribution of CMRFs and its association with various proxy measures of area-level socioeconomic disadvantage (ASED) among the adult ( ≥ 18 years) population across the world. Methods A systematic search for published articles was conducted in four databases (MEDLINE (Ovid), PubMed, Scopus and Web of Science) considering the interdisciplinary nature of the review question. Population-based cross-sectional and cohort studies on geographic variations of one or more biological proxies of CMRFs with/without an analysed contextual association with ASED were included. Two independent reviewers screened the studies and PRISMA guidelines were followed in the study selection and reporting. Result A total of 265 studies were retrieved and screened, resulting in 24 eligible studies. The review revealed reports of variation in the Distribution of CMRFs, at varying geographic scales, in multiple countries. In addition, consistent associations between ASED and higher prevalence of CMRFs were demonstrated. The reports were mainly from industrialised nations and small area geographic units were frequently used. Conclusion Geographic variation in cardiometabolic risk exists across multiple spatial scales and is positively associated with ASED. This association is independent of individual-level Factors and provides an imperative for area-based approaches to informing policy and health service organisation. The study protocol is registered in International prospective register of systematic reviews (Register No: CRD42018115294) PROSPERO 2018.
Darren J Mayne - One of the best experts on this subject based on the ideXlab platform.
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geographic and area level socioeconomic variation in cardiometabolic risk Factor Distribution a systematic review of the literature
International Journal of Health Geographics, 2019Co-Authors: Renin Toms, Andrew D Bonney, Darren J Mayne, Xiaoqi Feng, Ramya WalsanAbstract:A growing number of publications report variation in the Distribution of cardiometabolic risk Factors (CMRFs) at different geographic scales. A review of these variations may help inform policy and health service organisation. To review studies reporting variation in the geographic Distribution of CMRFs and its association with various proxy measures of area-level socioeconomic disadvantage (ASED) among the adult ( ≥ 18 years) population across the world. A systematic search for published articles was conducted in four databases (MEDLINE (Ovid), PubMed, Scopus and Web of Science) considering the interdisciplinary nature of the review question. Population-based cross-sectional and cohort studies on geographic variations of one or more biological proxies of CMRFs with/without an analysed contextual association with ASED were included. Two independent reviewers screened the studies and PRISMA guidelines were followed in the study selection and reporting. A total of 265 studies were retrieved and screened, resulting in 24 eligible studies. The review revealed reports of variation in the Distribution of CMRFs, at varying geographic scales, in multiple countries. In addition, consistent associations between ASED and higher prevalence of CMRFs were demonstrated. The reports were mainly from industrialised nations and small area geographic units were frequently used. Geographic variation in cardiometabolic risk exists across multiple spatial scales and is positively associated with ASED. This association is independent of individual-level Factors and provides an imperative for area-based approaches to informing policy and health service organisation. The study protocol is registered in International prospective register of systematic reviews (Register No: CRD42018115294) PROSPERO 2018.
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Geographic and area-level socioeconomic variation in cardiometabolic risk Factor Distribution: a systematic review of the literature
International Journal of Health Geographics, 2019Co-Authors: Renin Toms, Ramya Walsan, Andrew Bonney, Darren J Mayne, Xiaoqi FengAbstract:Introduction A growing number of publications report variation in the Distribution of cardiometabolic risk Factors (CMRFs) at different geographic scales. A review of these variations may help inform policy and health service organisation. Aim To review studies reporting variation in the geographic Distribution of CMRFs and its association with various proxy measures of area-level socioeconomic disadvantage (ASED) among the adult ( ≥ 18 years) population across the world. Methods A systematic search for published articles was conducted in four databases (MEDLINE (Ovid), PubMed, Scopus and Web of Science) considering the interdisciplinary nature of the review question. Population-based cross-sectional and cohort studies on geographic variations of one or more biological proxies of CMRFs with/without an analysed contextual association with ASED were included. Two independent reviewers screened the studies and PRISMA guidelines were followed in the study selection and reporting. Result A total of 265 studies were retrieved and screened, resulting in 24 eligible studies. The review revealed reports of variation in the Distribution of CMRFs, at varying geographic scales, in multiple countries. In addition, consistent associations between ASED and higher prevalence of CMRFs were demonstrated. The reports were mainly from industrialised nations and small area geographic units were frequently used. Conclusion Geographic variation in cardiometabolic risk exists across multiple spatial scales and is positively associated with ASED. This association is independent of individual-level Factors and provides an imperative for area-based approaches to informing policy and health service organisation. The study protocol is registered in International prospective register of systematic reviews (Register No: CRD42018115294) PROSPERO 2018.
Debabrata Biswas - One of the best experts on this subject based on the ideXlab platform.
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shielding effects in random large area field emitters the field enhancement Factor Distribution and current calculation
Physics of Plasmas, 2018Co-Authors: Rashbihari Rudra, Debabrata BiswasAbstract:A finite-size uniform random Distribution of vertically aligned field emitters on a planar surface is studied under the assumption that the asymptotic field is uniform and parallel to the emitter axis. A formula for field enhancement Factor is first derived for a 2-emitter system and this is then generalized for N-emitters placed arbitrarily (line, array, or random). It is found that geometric effects dominate the shielding of field lines. The Distribution of field enhancement Factor for a uniform random Distribution of emitter locations is found to be closely approximated by an extreme value (Gumbel-minimum) Distribution when the mean separation is greater than the emitter height but is better approximated by a Gaussian for mean separations close to the emitter height. It is shown that these Distributions can be used to accurately predict the current emitted from a large area field emitter.A finite-size uniform random Distribution of vertically aligned field emitters on a planar surface is studied under the assumption that the asymptotic field is uniform and parallel to the emitter axis. A formula for field enhancement Factor is first derived for a 2-emitter system and this is then generalized for N-emitters placed arbitrarily (line, array, or random). It is found that geometric effects dominate the shielding of field lines. The Distribution of field enhancement Factor for a uniform random Distribution of emitter locations is found to be closely approximated by an extreme value (Gumbel-minimum) Distribution when the mean separation is greater than the emitter height but is better approximated by a Gaussian for mean separations close to the emitter height. It is shown that these Distributions can be used to accurately predict the current emitted from a large area field emitter.
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shielding effects in random large area field emitters the field enhancement Factor Distribution and current calculation
Physics of Plasmas, 2018Co-Authors: Debabrata Biswas, Rashbihari RudraAbstract:A finite-size uniform random Distribution of vertically aligned field emitters on a planar surface is studied under the assumption that the asymptotic field is uniform and parallel to the emitter axis. A formula for field enhancement Factor is first derived for a 2-emitter system and this is then generalized for N-emitters placed arbitrarily (line, array, or random). It is found that geometric effects dominate the shielding of field lines. The Distribution of field enhancement Factor for a uniform random Distribution of emitter locations is found to be closely approximated by an extreme value (Gumbel-minimum) Distribution when the mean separation is greater than the emitter height but is better approximated by a Gaussian for mean separations close to the emitter height. It is shown that these Distributions can be used to accurately predict the current emitted from a large area field emitter.
