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1.
Dis Colon Rectum ; 63(2): 226-232, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31914115

RESUMO

BACKGROUND: Online physician rating Web sites are used by over half of consumers to select doctors. No studies have examined physician rating Web sites for colon and rectal surgeons. OBJECTIVE: The purpose of this study was to evaluate the accuracy and rating patterns of colon and rectal surgeons on the largest physician rating Web site. DESIGN: Physician characteristics and ratings were collected from a randomly selected sample of 500 from 3043 Healthgrades "colon and rectal surgery specialists." Board certifications were verified with the American Board of Surgery and American Board of Colon and Rectal Surgery Web sites. SETTINGS: Data acquisition was completed on July 18, 2018. PATIENTS: Patients were not directly studied. MAIN OUTCOME MEASURES: The primary outcome was to assess the accuracy of Healthgrades in reporting American Board of Surgery and American Board of Colon and Rectal Surgery certification. The secondary outcome was to identify factors associated with high star ratings. RESULTS: A total of 48 (9.6%) of the 500 sampled were incorrectly identified as practicing US surgeons and excluded from subsequent analysis. Healthgrades showed 80.1% agreement with verified board certifications for American Board of Surgery and 85.4% for American Board of Colon and Rectal Surgery. The mean star rating was 4.2 of 5.0 (SD = 0.9), and 77 (21.6%) had 5-star ratings. In a multivariable logistic model (p < 0.001), 5-star rating was associated with 1 to 9 years (OR = 2.76; p = 0.04) or >40 years in practice (OR = 3.35; p = 0.04) and fewer reviews (OR = 0.88; p < 0.001). There were no significant associations with surgeon sex, age, geographic region, or board certification. LIMITATIONS: Data were limited to a single physician rating Web site. CONCLUSIONS: In the modern age of healthcare consumerism, physician rating Web sites should be used with caution given inaccuracies. More accurate online resources are needed to inform patient decisions in the selection of specialized colon and rectal surgical care. See Video Abstract at http://links.lww.com/DCR/B91. PRECISIÓN DE DATOS Y PREDICTORES DE ALTAS CALIFICACIONES DE CIRUJANOS DE COLON Y RECTO EN UN SITIO WEB DE CALIFICACIÓN MÉDICA EN LÍNEA: Más de la mitad de los consumidores utilizan los sitios web de calificación de médicos en línea para seleccionar médicos. Ningún estudio ha examinado los sitios web de calificación de médicos para cirujanos de colon y recto.Evaluar la precisión y los patrones de calificación de los cirujanos de colon y recto en el sitio web más grande de calificación de médicos.Las características y calificaciones de los médicos se obtuvieron de una muestra seleccionada al azar de 500 de 3,043 "especialistas en cirugía de colon y recto" de Healthgrades. Las certificaciones del Consejo se verificaron en los sitios web del Consejo Americano de Cirugía y del Consejo Americano de Cirugía de Colon y Recto.La adquisición de datos se completó el 18 de julio de 2018.Los pacientes no fueron estudiados directamente.El resultado primario fue evaluar la precisión de Healthgrades al informar la certificación por el Consejo Americano de Cirugía y por el Consejo Americano de Cirugía de Colon y Recto. El resultado secundario fue identificar factores asociados con altas calificaciones en estrellas.Un total de 48 (9.6%) de la muestra de 500 fueron identificados incorrectamente como cirujanos practicantes de EE. UU. y excluidos del análisis subsecuente. Healthgrades mostró un 80.1% de concordancia con las certificaciones verificadas del Consejo Americano de Cirugía y el 85.4% con el Consejo Americano de Cirugía de Colon y Recto. La calificación promedio de estrellas fue 4.2 / 5 (SD 0.9), y 77 (21.6%) tuvieron calificaciones de 5 estrellas. En un modelo logístico multivariable (p <0.001), la calificación de 5 estrellas se asoció con 1-9 años (OR 2.76, p = 0.04) o más de 40 años en la práctica (OR 3.35, p = 0.04) y menos evaluaciones (OR 0.88, p <0.001). No hubo asociaciones significativas con el género, edad, región geográfica o certificación por los Consejos del cirujano.Los datos se limitaron a un solo sitio web de calificación de médicos.En la era moderna del consumismo en atención médica, los sitios web de calificación de los médicos deben usarse con precaución debido a imprecisiones. Se necesitan recursos en línea más precisos para que las decisiones de los pacientes sean informadas en la selección de atención quirúrgica especializada de colon y recto. Consulte Video Resumen en http://links.lww.com/DCR/B91. (Traducción-Dr. Jorge Silva-Velazco).


Assuntos
Colo/cirurgia , Sistemas On-Line/instrumentação , Reto/cirurgia , Cirurgiões/estatística & dados numéricos , Confiabilidade dos Dados , Feminino , Humanos , Internet , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Valor Preditivo dos Testes , Conselhos de Especialidade Profissional/organização & administração , Cirurgiões/organização & administração
2.
J Neuroeng Rehabil ; 17(1): 58, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32345335

RESUMO

BACKGROUND: Compensations are commonly observed in patients with stroke when they engage in reaching without supervision; these behaviors may be detrimental to long-term functional improvement. Automatic detection and reduction of compensation cab help patients perform tasks correctly and promote better upper extremity recovery. OBJECTIVE: Our first objective is to verify the feasibility of detecting compensation online using machine learning methods and pressure distribution data. Second objective was to investigate whether compensations of stroke survivors can be reduced by audiovisual or force feedback. The third objective was to compare the effectiveness of audiovisual and force feedback in reducing compensation. METHODS: Eight patients with stroke performed reaching tasks while pressure distribution data were recorded. Both the offline and online recognition accuracy were investigated to assess the feasibility of applying a support vector machine (SVM) based compensation detection system. During reduction of compensation, audiovisual feedback was delivered using virtual reality technology, and force feedback was delivered through a rehabilitation robot. RESULTS: Good classification performance was obtained in online compensation recognition, with an average F1-score of over 0.95. Based on accurate online detection, real-time feedback significantly decreased compensations of patients with stroke in comparison with no-feedback condition (p < 0.001). Meanwhile, the difference between audiovisual and force feedback was also significant (p < 0.001) and force feedback was more effective in reducing compensation in patients with stroke. CONCLUSIONS: Accurate online recognition validated the feasibility of monitoring compensations using machine learning algorithms and pressure distribution data. Reliable online detection also paved the way for reducing compensations by providing feedback to patients with stroke. Our findings suggested that real-time feedback could be an effective approach to reducing compensatory patterns and force feedback demonstrated a more enviable potential compared with audiovisual feedback.


Assuntos
Adaptação Fisiológica/fisiologia , Sistemas On-Line , Reabilitação do Acidente Vascular Cerebral/instrumentação , Reabilitação do Acidente Vascular Cerebral/métodos , Adulto , Idoso , Retroalimentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sistemas On-Line/instrumentação , Projetos Piloto , Acidente Vascular Cerebral/fisiopatologia , Máquina de Vetores de Suporte , Sobreviventes , Extremidade Superior/fisiopatologia , Realidade Virtual
3.
Artigo em Inglês | MEDLINE | ID: mdl-29473786

RESUMO

To enable further study and assessment of indoor inhalation exposure risk, an online apparatus enabling measurement of semi-volatile compound partitioning on household particulates was developed. An example for use of the apparatus is described using dimethyl phthalate (DMP). The system employs direct measurement by membrane introduction mass spectrometry (MIMS). The MIMS system was calibrated using known gas phase DMP concentrations produced by gravimetrically calibrated permeation devices. The quantity of DMP sorbed by particles is described first using a model particle type, a reverse-phase liquid chromatography packing material, and then with a household dust sample. In addition, the desorption of semi-volatile compounds from a household dust sample was monitored using the apparatus, and characteristic fragment ion signals for phthalate compounds were observed.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Poeira/análise , Espectrometria de Massas/métodos , Sistemas On-Line , Material Particulado/análise , Ácidos Ftálicos/análise , Adsorção , Calibragem , Cromatografia Gasosa-Espectrometria de Massas/métodos , Cromatografia Gasosa-Espectrometria de Massas/normas , Humanos , Espectrometria de Massas/normas , Sistemas On-Line/instrumentação , Sistemas On-Line/normas , Material Particulado/farmacocinética , Ácidos Ftálicos/farmacocinética
4.
Water Sci Technol ; 75(11-12): 2716-2725, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28617291

RESUMO

The removal of total nitrogen in wastewater treatment plants (WWTPs) is often unsatisfactory for a variety of reasons. One possible measure to improve nitrogen removal is the addition of external carbon. However, the amount of carbon addition is directly related to WWTP operation costs, highlighting the importance of accurately determining the amount of external carbon required. The objective of this study was to obtain a low nitrate concentration in the anoxic zone of WWTPs efficiently and economically by optimizing the external carbon source dosage. Experiments were conducted using a pilot-scale pre-denitrification reactor at a Nanjing WWTP in China. External carbon source addition based on online monitoring of influent wastewater quality and a developed nitrification-denitrification numerical model was investigated. Results showed that carbon addition was reduced by 47.7% and aeration costs were reduced by 8.0% compared with those using a fixed-dose addition mode in the pilot reactor. The obtained technology was applied to the full-scale Jiangxinzhou WWTP in Nanjing with promising results.


Assuntos
Carbono/análise , Desnitrificação , Sistemas On-Line/instrumentação , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/análise , Poluentes Químicos da Água/análise , China , Monitoramento Ambiental , Modelos Teóricos , Projetos Piloto , Eliminação de Resíduos Líquidos/instrumentação
5.
Sensors (Basel) ; 15(8): 20698-716, 2015 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-26307993

RESUMO

The aim of this study is a further characterization of the electrical conductivity (EC) signal of goat milk, acquired on-line by EC sensors, to identify new indexes representative of the EC variations that can be observed during milking, when considering not healthy (NH) glands. Two foremilk gland samples from 42 Saanen goats, were collected for three consecutive weeks and for three different lactation stages (LS: 0-60 Days In Milking (DIM); 61-120 DIM; 121-180 DIM), for a total amount of 1512 samples. Bacteriological analyses and somatic cells counts (SCC) were used to define the health status of the glands. With negative bacteriological analyses and SCC < 1,000,000 cells/mL, glands were classified as healthy. When bacteriological analyses were positive or showed a SCC > 1,000,000 cells/mL, glands were classified as NH. For each milk EC signal, acquired on-line and for each gland considered, the Fourier frequency spectrum of the signal was calculated and three representative frequency peaks were identified. To evaluate data acquired a MIXED procedure was used considering the HS, LS and LS × HS as explanatory variables in the statistical model.Results showed that the studied frequency peaks had a significant relationship with the gland's health status. Results also explained how the milk EC signals' pattern change in case of NH glands. In fact, it is characterized by slower fluctuations (due to the lower frequencies of the peaks) and by an irregular trend (due to the higher amplitudes of all the main frequency peaks). Therefore, these frequency peaks could be used as new indexes to improve the performances of algorithms based on multivariate models which evaluate the health status of dairy goats through the use of gland milk EC sensors.


Assuntos
Indústria de Laticínios , Condutividade Elétrica , Análise de Fourier , Nível de Saúde , Leite/química , Sistemas On-Line/instrumentação , Processamento de Sinais Assistido por Computador , Animais , Feminino , Cabras , Lactação , Modelos Lineares , Glândulas Mamárias Animais/microbiologia
6.
Anal Bioanal Chem ; 406(7): 1975-84, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24510210

RESUMO

To find potential lead compounds for antigout drug discovery, an automated online, restricted-access material coupled with column-switching liquid chromatography with a diode-array detection (RAM-LC-DAD) system was developed for screening of xanthine oxidase (XO) inhibitors and their affinity rankings in complex mixtures. The system was first evaluated by analyzing a mixture of six compounds with known inhibition of XO. Nonspecific binding to the denatured XO was investigated and used as the control for screening. Subsequently, the newly developed system was applied to screening of a natural product, Oroxylum indicum extract, and four compounds which could specifically interact with XO were found and identified as oroxin B, oroxin A, baicalin, and baicalein. The results were verified by a competitive binding test using the known competitive inhibitor allopurinol and were further validated by an inhibition assay in vitro. The online RAM-LC-DAD system developed was shown to be a simple and effective strategy for the rapid screening of bioactive compounds from a complex mixture.


Assuntos
Bignoniaceae/química , Descoberta de Drogas/métodos , Inibidores Enzimáticos/isolamento & purificação , Sistemas On-Line/instrumentação , Xantina Oxidase/antagonistas & inibidores , Ligação Competitiva , Cromatografia Líquida de Alta Pressão , Descoberta de Drogas/instrumentação , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Extratos Vegetais/química , Ligação Proteica , Reprodutibilidade dos Testes , Sementes/química , Extração em Fase Sólida , Espectrometria de Massas em Tandem
7.
Health Info Libr J ; 31(2): 167-71, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24762256

RESUMO

This article describes the development and delivery of an online module at the University of Nottingham on the literature review process. In particular, it discusses how academic librarians collaborated with researcher developers at the Graduate School at the University to deliver a highly successful online learning experience for students. The article provides an overview of the course, a discussion on the experiences of both the tutors and participants involved, concentrating specifically on those in Medicine and Health Sciences. Details about future international collaborations and development of the course are also provided.


Assuntos
Instrução por Computador/métodos , Comportamento Cooperativo , Educação de Pós-Graduação em Medicina/métodos , Biblioteconomia/métodos , Sistemas On-Line , Alfabetização Digital , Instrução por Computador/instrumentação , Educação a Distância , Humanos , Sistemas On-Line/instrumentação , Reino Unido
8.
Behav Res Methods ; 46(2): 430-8, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24061930

RESUMO

Social networking has surpassed e-mail and instant messaging as the dominant form of online communication (Meeker, Devitt, & Wu, 2010). Currently, all large social networks are proprietary, making it difficult to impossible for researchers to make changes to such networks for the purpose of study design and access to user-generated data from the networks. To address this issue, the authors have developed and present Social Lab, an Internet-based free and open-source social network software system available from http://www.sociallab.es . Having full availability of navigation and communication data in Social Lab allows researchers to investigate behavior in social media on an individual and group level. Automated artificial users ("bots") are available to the researcher to simulate and stimulate social networking situations. These bots respond dynamically to situations as they unfold. The bots can easily be configured with scripts and can be used to experimentally manipulate social networking situations in Social Lab. Examples for setting up, configuring, and using Social Lab as a tool for research in social media are provided.


Assuntos
Pesquisa Comportamental/instrumentação , Sistemas de Informação em Laboratório Clínico/instrumentação , Mídias Sociais/instrumentação , Rede Social , Software , Acesso à Informação , Pesquisa Comportamental/métodos , Segurança Computacional , Apresentação de Dados , Humanos , Sistemas On-Line/instrumentação , Privacidade , Linguagens de Programação , Design de Software , Interface Usuário-Computador , Jogos de Vídeo
9.
Anal Chem ; 85(19): 8928-32, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-24003862

RESUMO

Detector response is not always equivalent between detectors or instrument types. Factors that impact detector response include molecular structure and detection wavelength. In liquid chromatography (LC), ultraviolet (UV) is often the primary detector; however, without determination of UV response factors for each analyte, chromatographic results are reported on an area percent rather than a weight percent. In extreme cases, response factors can differ by several orders of magnitude for structurally dissimilar compounds, making the uncalibrated data useless for quantitative applications. While impurity reference standards are normally used to calculate UV relative response factors (RRFs), reference standards of reaction mixture components are typically not available during route scouting or in the early stages of process development. Here, we describe an approach to establish RRFs from a single experiment using both online nuclear magnetic resonance (NMR) and LC. NMR is used as a mass detector from which a UV response factor can be determined to correct the high performance liquid chromatography (HPLC) data. Online reaction monitoring using simultaneous NMR and HPLC provides a platform to expedite the development and understanding of pharmaceutical reaction processes. Ultimately, the knowledge provided by a structurally information rich technique such as NMR can be correlated with more prevalent and mobile instrumentation [e.g., LC, mid-infrared spectrometers (MIR)] for additional routine process understanding and optimization.


Assuntos
Cromatografia Líquida de Alta Pressão/instrumentação , Espectroscopia de Ressonância Magnética/instrumentação , Sistemas On-Line/instrumentação , Preparações Farmacêuticas/química , Tecnologia Farmacêutica/instrumentação , Estrutura Molecular
11.
Environ Sci Technol ; 47(17): 9850-7, 2013 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-23883353

RESUMO

A new automated, sensitive, and fast system for the simultaneous online isolation and preconcentration of lead and strontium by sorption on a microcolumn packed with Sr-resin using an inductively coupled plasma mass spectrometry (ICP-MS) detector was developed, hyphenating lab-on-valve (LOV) and multisyringe flow injection analysis (MSFIA). Pb and Sr are directly retained on the sorbent column and eluted with a solution of 0.05 mol L(-1) ammonium oxalate. The detection limits achieved were 0.04 ng for lead and 0.03 ng for strontium. Mass calibration curves were used since the proposed system allows the use of different sample volumes for preconcentration. Mass linear working ranges were between 0.13 and 50 ng and 0.1 and 50 ng for lead and strontium, respectively. The repeatability of the method, expressed as RSD, was 2.1% and 2.7% for Pb and Sr, respectively. Environmental samples such as rainwater and airborne particulate (PM10) filters as well as a certified reference material SLRS-4 (river water) were satisfactorily analyzed obtaining recoveries between 90 and 110% for both elements. The main features of the LOV-MSFIA-ICP-MS system proposed are the capability to renew solid phase extraction at will in a fully automated way, the remarkable stability of the column which can be reused up to 160 times, and the potential to perform isotopic analysis.


Assuntos
Poluentes Atmosféricos/análise , Processamento Eletrônico de Dados/métodos , Monitoramento Ambiental/métodos , Chumbo/análise , Estrôncio/análise , Análise de Injeção de Fluxo/métodos , Isótopos/análise , Espectrometria de Massas , Sistemas On-Line/instrumentação , Chuva/química , Reprodutibilidade dos Testes , Extração em Fase Sólida/métodos , Isótopos de Estrôncio/análise
12.
Soc Psychiatry Psychiatr Epidemiol ; 48(5): 821-34, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22976338

RESUMO

PURPOSE: To establish the current prevalence of gambling and problem gambling in South Korea and to determine the associated demographic and game play patterns. METHODS: Administration of a gambling survey over the phone to 4,000 randomly selected South Korean adults (19+), supplemented by an online survey of 4,330 members of a South Korean online panel. RESULTS: The past year prevalence of gambling among South Korean adults was 41.8 %. The past year engagement in individual forms of gambling was 36.2 % for lotteries and instant lotteries; 12.0 % for social gambling; 2.3 % for sports betting; 1.5 % for casino gambling; 1.5 % for internet gambling; and 1.1 % for horse, bicycle, or motor boat betting. The past year prevalence of problem gambling was 0.5 %. Logistic regression identified the best predictors of problem gambling to be: having a greater number of gambling fallacies; gambling on the internet; betting on horses, bicycling, or motor boat racing; social gambling; male gender; mental health problems; sports betting; motivation for gambling (gambling to escape); casino gambling; and lower income. CONCLUSIONS: The past year prevalence of gambling (41.8 %) and problem gambling (0.5 %) in South Korea is low compared to other countries, especially relative to other Asian jurisdictions. This relatively low prevalence of gambling is likely related to the very strong negative attitudes toward it, the low participation by females, and restricted access. The low prevalence of problem gambling is likely related to the relatively low prevalence of gambling and restricted access to continuous forms of gambling. The variables that are predictive of problem gambling in South Korea are quite similar to those found in other countries with a couple of important differences.


Assuntos
Comportamento Aditivo/epidemiologia , Jogo de Azar/epidemiologia , Internet/estatística & dados numéricos , Transtornos Mentais/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Adulto , Idoso , Comorbidade , Diagnóstico Duplo (Psiquiatria) , Feminino , Jogo de Azar/classificação , Jogo de Azar/psicologia , Nível de Saúde , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Sistemas On-Line/instrumentação , Prevalência , República da Coreia/epidemiologia , Distribuição por Sexo , Classe Social , Fatores Socioeconômicos , Inquéritos e Questionários
13.
ScientificWorldJournal ; 2013: 923901, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24453923

RESUMO

Online monitoring humidity in the proton exchange membrane (PEM) fuel cell is an important issue in maintaining proper membrane humidity. The cost and size of existing sensors for monitoring humidity are prohibitive for online measurements. Online prediction of humidity using readily available measured data would be beneficial to water management. In this paper, a novel soft sensor method based on dynamic partial least squares (DPLS) regression is proposed and applied to humidity prediction in PEM fuel cell. In order to obtain data of humidity and test the feasibility of the proposed DPLS-based soft sensor a hardware-in-the-loop (HIL) test system is constructed. The time lag of the DPLS-based soft sensor is selected as 30 by comparing the root-mean-square error in different time lag. The performance of the proposed DPLS-based soft sensor is demonstrated by experimental results.


Assuntos
Fontes de Energia Elétrica , Monitoramento Ambiental , Umidade , Membranas Artificiais , Sistemas On-Line/instrumentação , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos
14.
J Environ Manage ; 129: 377-83, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-23994580

RESUMO

A fully automated on-line system for monitoring the photocatalytic degradation of herbicides was developed using multisyringe flow injection analysis (MSFIA) coupled to a solid phase extraction (SPE) unit with UV detection. The calibration curves were linear in the concentration range of 100-1000 µg L(-1) for 3,6-dichloro-2-methoxybenzoic acid (dicamba) and 500-3000 µg L(-1) for 2,4-dichlorophenoxyacetic acid (2,4-D), while the detection limits were 30 and 135 µg L(-1) for dicamba and 2,4-D, respectively. The monitoring of the photocatalytic degradation (TiO2 anatase/UV 254 nm) of these two herbicides was performed by MSFIA-SPE system using a small sample volume (2 mL) in a fully automated approach. The degradation was assessed in ultrapure and drinking water with initial concentrations of 1000 and 2000 µg L(-1) for dicamba and 2,4-D, respectively. Degradation percentages of approximately 85% were obtained for both herbicides in ultrapure water after 45 min of photocatalytic treatment. A similar degradation efficiency in drinking water was observed for 2,4-D, whereas dicamba exhibited a lower degradation percentage (75%), which could be attributed to the presence of inorganic species in this kind of water.


Assuntos
Ácido 2,4-Diclorofenoxiacético/análise , Dicamba/análise , Monitoramento Ambiental/métodos , Herbicidas/análise , Sistemas On-Line , Poluentes Químicos da Água/análise , Ácido 2,4-Diclorofenoxiacético/química , Dicamba/química , Monitoramento Ambiental/instrumentação , Análise de Injeção de Fluxo/instrumentação , Análise de Injeção de Fluxo/métodos , Herbicidas/química , Sistemas On-Line/instrumentação , Fotólise , Extração em Fase Sólida/instrumentação , Extração em Fase Sólida/métodos , Poluentes Químicos da Água/química
15.
J Environ Sci Health B ; 48(11): 893-905, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23998301

RESUMO

A simple and rapid online microchannel preconcentrator coupled with an amperometric detection for the analysis of carbofuran using polyethylene glycol coated onto magnetic particle (PEG-magnetic particles) sorbents was developed. This simple-to-prepare microchannel preconcentrator used an external magnet to retain the PEG-magnetic particle sorbents inside the microchannel. Under optimum conditions, the system provided two linear ranges, from 0.01 to 10.0 mg L(-1) and from 10.0 to 130.0 mg L(-1) with a limit of detection of 8.7 ± 0.1 µg L(-1). The microchannel preconcentrator provided very good stability; it can be used for up to 326 consecutive injections of 5.0 mg L(-1) carbofuran with a relative standard deviation of less than 3%. The developed system provided a good microchannel-to-microchannel and a good electrode-to-electrode reproducibility (n = 6, %RSD < 1). It also provided an excellent selectivity when it was tested with two other carbamate pesticides, carbaryl and methomyl, with a 43 and 256 times higher detection sensitivity for carbofuran, respectively. The developed system was successfully applied to detect carbofuran in surface water samples obtained near vegetable plantation areas. The concentrations of carbofuran in these samples were found to be in the range of non-detectable to 0.047 ± 0.001 mg L(-1). The developed system is easy to operate and easy to couple with other analytical instruments and it could be easily adapted for the analysis of other polar organic contaminants.


Assuntos
Carbofurano/análise , Monitoramento Ambiental/métodos , Sistemas On-Line/instrumentação , Praguicidas/análise , Poluentes Químicos da Água/análise , Carbaril/análise , Monitoramento Ambiental/instrumentação , Cromatografia Gasosa-Espectrometria de Massas , Fenômenos Magnéticos , Metomil/análise , Polietilenoglicóis/química , Sensibilidade e Especificidade
16.
Analyst ; 137(23): 5632-8, 2012 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-23076165

RESUMO

Here we present a validated rapid detection system for propofol, an anaesthetic with a narrow therapeutic window, in whole blood. This method utilises an on-line molecularly imprinted polymer solid-phase extraction, rather than the traditional C18 solid-phase extraction, coupled to fluorescence optical fibre detection. The linearity was assessed from 0.10-15 µg mL(-1) of propofol in whole blood, and the coefficients were greater than 0.995. The absolute recoveries of propofol were 95.81, 97.56 and 97.93% at three different concentrations. The inter-batch precision ranged from 4.3% to 8.1%, and the accuracy value ranged from 102.5% to 104.4%. The developed method was successfully applied to measure propofol concentrations in simulated whole blood samples. The entire analysis procedure lasted only 5 minutes, and the results showed no statistical difference between the new on-line method and a validated high-performance liquid chromatography method. The new on-line method, however, is faster and more convenient for the clinical real-time detection of propofol than previously reported methods.


Assuntos
Sistemas On-Line/instrumentação , Propofol/sangue , Cromatografia Líquida de Alta Pressão , Fluorescência , Humanos , Impressão Molecular , Fibras Ópticas , Extração em Fase Sólida/métodos
17.
Environ Sci Technol ; 46(7): 4067-73, 2012 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-22420672

RESUMO

Plasma air purifying systems present an interesting alternative to filters for purifying air. In this study, molecular processes in a commercially available ac driven plasma air purifier were studied in detail. This air purifier is supposed to reduce all air contaminants to small nontoxic molecules (e.g., H(2)O and CO(2)). However, degradation mechanisms are not yet fully understood. In this study, we investigated the exhaust of the plasma air purifier to determine which degradation products are formed. An interface was designed and constructed to allow the direct coupling of the plasma air purifier's exhaust to a mass spectrometer. The compounds studied, primary and secondary amines, were introduced at a concentration of 1 ppmV. Contrary to our expectations, polymerization instead of degradation was observed. The higher the ac voltage applied (max. 9.0 kV) to the plasma air purifier, the higher the mass of the oligomer distribution. Side chain oxidation products as well as oligomers could be observed for all compounds tested. Starting with amines of low mass (m/z < 200), compounds of molecular masses above 1000 Da were observed in the plasma air purifier. Detailed analysis of the observed mass spectra as well as experiments with deuterated dibutylamine helped to unravel the mechanism taking place in the plasma air purifier. Nitrate anions generated in the plasma air purifier (presumably from N(2)) are proposed to form ionic clusters with protonated amines.


Assuntos
Poluentes Atmosféricos/isolamento & purificação , Poluição do Ar/prevenção & controle , Monitoramento Ambiental/instrumentação , Sistemas On-Line/instrumentação , Gases em Plasma/química , Butilaminas/química , Deutério , Eletricidade , Espectrometria de Massas
18.
Sensors (Basel) ; 12(10): 13295-332, 2012 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23201997

RESUMO

This paper presents a new methodology for collaborative sensor data management known as WikiSensing. It is a novel approach that incorporates online collaboration with sensor data management. We introduce the work on this research by describing the motivation and challenges of designing and developing an online collaborative sensor data management system. This is followed by a brief survey on popular sensor data management and online collaborative systems. We then present the architecture for WikiSensing highlighting its main components and features. Several example scenarios are described to present the functionality of the system. We evaluate the approach by investigating the performance of aggregate queries and the scalability of the system.


Assuntos
Técnicas Biossensoriais/instrumentação , Redes de Comunicação de Computadores/instrumentação , Sistemas de Informação/instrumentação , Internet , Tecnologia sem Fio/instrumentação , Bases de Dados Factuais , Monitoramento Ambiental/instrumentação , Humanos , Sistemas On-Line/instrumentação , Interface Usuário-Computador
19.
Anal Chem ; 83(3): 1015-21, 2011 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-21162592

RESUMO

Salts and buffers, commonly used in isolation and stabilization of biological analytes, have a deleterious effect on electrospray ionization mass spectrometry (ESI-MS). Excessive concentrations of salts lead to ion suppression and adduct formation, which mask or complicate ion signals. In this work, we describe a salt remover (SR), configured as a three-compartment flow-through system, where the central compartment is separated from the outer compartments by a cation-exchange membrane (CEM) and an anion-exchange membrane (AEM). One platinum electrode is placed in each of the outer compartments, where water or electrolyte is flowing. The CEM electrode is held at a negative potential relative to the AEM side; cations/anions migrate by electrophoresis to the CEM/AEM receiver liquids, respectively. Proteins have poorer electrophoretic mobility relative to the buffer components, permitting removal of the salt. The salt-free proteins proceed to the ESI source. The capillary scale SR (internal volume 2.5 µL) described here effectively desalted continuous flows of NaCl solutions (200 mequiv/L at 1 µL/min, equivalent to a flux of 200 nequiv/min with 88% efficiency) and achieved >99.8% salt removal with 154 mM NaCl (isotonic saline) at 1 µL/min. With optimized current, >80% of concurrently present 20 µM protein was transmitted. Desalting efficiency and analyte loss was evaluated with different salt concentration and flow rate combinations under different applied current. Good-quality ESI-MS spectra of cytochrome c, myoglobin, and lysozyme as test proteins in a saline solution, passed through the SR, are demonstrated.


Assuntos
Diálise/métodos , Sistemas On-Line , Cloreto de Sódio/isolamento & purificação , Espectrometria de Massas por Ionização por Electrospray/métodos , Animais , Bovinos , Galinhas , Citocromos c'/análise , Diálise/instrumentação , Eletrodos , Cavalos , Muramidase/análise , Mioglobina/análise , Sistemas On-Line/instrumentação , Espectrometria de Massas por Ionização por Electrospray/instrumentação
20.
Environ Sci Technol ; 45(19): 8536-44, 2011 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-21875062

RESUMO

We describe a flow-through biosensor for online continuous water toxicity monitoring. At the heart of the device are disposable modular biochips incorporating agar-immobilized bioluminescent recombinant reporter bacteria, the responses of which are probed by single-photon avalanche diode detectors. To demonstrate the biosensor capabilities, we equipped it with biochips harboring both inducible and constitutive reporter strains and exposed it to a continuous water flow for up to 10 days. During these periods we challenged the biosensor with 2-h pulses of water spiked with model compounds representing different classes of potential water pollutants, as well as with a sample of industrial wastewater. The biosensor reporter panel detected all simulated contamination events within 0.5-2.5 h, and its response was indicative of the nature of the contaminating chemicals. We believe that a biosensor of the proposed design can be integrated into future water safety and security networks, as part of an early warning system against accidental or intentional water pollution by toxic chemicals.


Assuntos
Bactérias/metabolismo , Técnicas Biossensoriais/instrumentação , Monitoramento Ambiental/instrumentação , Medições Luminescentes/instrumentação , Análise em Microsséries/instrumentação , Sistemas On-Line/instrumentação , Poluentes Químicos da Água/toxicidade , Antimônio/análise , Antimônio/toxicidade , Arsênio/análise , Arsênio/toxicidade , Genes Reporter , Resíduos Industriais/análise , Fatores de Tempo , Eliminação de Resíduos Líquidos
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