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Sources of signal fluctuations in functional magnetic resonance imaging at 7 Tesla 7特斯拉功能磁共振成像信号波动的来源
1st Portuguese Biomedical Engineering Meeting Pub Date : 2011-03-01 DOI: 10.1109/ENBENG.2011.6026092
J. Jorge, P. Figueiredo, W. van der Zwaag, J. Marques
{"title":"Sources of signal fluctuations in functional magnetic resonance imaging at 7 Tesla","authors":"J. Jorge, P. Figueiredo, W. van der Zwaag, J. Marques","doi":"10.1109/ENBENG.2011.6026092","DOIUrl":"https://doi.org/10.1109/ENBENG.2011.6026092","url":null,"abstract":"High-field magnetic resonance imaging (MRI) systems allow for critical improvements in image signal-to-noise ratio (SNR), potentially leading to higher sensitivity and spatial resolution for functional MRI (fMRI). 3D segmented echo volumar imaging (EVI) has recently been proposed for high-resolution fMRI at ultra-high fields. It provides higher image SNR than standard 2D echo planar imaging (EPI), but is also thought to be more sensitive to physiological noise. This becomes especially important at higher field strengths, where increased signal fluctuations from correlated noise sources, namely physiological processes, have been observed. This work is focused on the analysis of fMRI data acquired at 7T using standard EPI and segmented EVI. A principal component analysis-based approach and a physiological regressor-based approach were investigated for correlated noise characterization and correction. Although increases in physiological noise from EPI to segmented EVI were found, both corrective approaches produced significant improvements in temporal SNR, explained signal information, and activation sensitivity for either acquisition technique, and especially for segmented EVI.","PeriodicalId":206538,"journal":{"name":"1st Portuguese Biomedical Engineering Meeting","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129823534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Wavelet analysis of the autonomic outflowof the pupil's variation in normal subjects, given stimuli 小波分析正常受试者在给定刺激下瞳孔自主流出的变化
1st Portuguese Biomedical Engineering Meeting Pub Date : 2011-03-01 DOI: 10.1109/ENBENG.2011.6026066
G. Leal, C. Neves, P. Vieira
{"title":"Wavelet analysis of the autonomic outflowof the pupil's variation in normal subjects, given stimuli","authors":"G. Leal, C. Neves, P. Vieira","doi":"10.1109/ENBENG.2011.6026066","DOIUrl":"https://doi.org/10.1109/ENBENG.2011.6026066","url":null,"abstract":"This paper presents preliminary results of Wavelet analysis of the pupil size variation signal. A Pupillometer has been developed in order to detect the pupil's variation in time in a non-invasive way. The output signal of the equipment expresses the pupil's features variation in time (area, perimeter, vertical diameter, horizontal diameter). We know that the Autonomic Nervous System (ANS) is divided into the Sympathetic and Parasympathetic components and theoretically they are always competing with each other as a two oscillator model. The aim of this project is to identify these components and their frequency bands. With the present results we show that the signal from the pupil's variation has two major frequency bands, the first being the 0–1 Hz band (LF — Low Frequency) and the second being 1–2Hz band (HF — High Frequency). From the literature we know that the Sympathetic Nervous System (SNS) behaves in a lower frequency than the Parasympathetic (PSNS) one. This means that SNS oscillates in the LF band and PSNS oscillates in the HF band.","PeriodicalId":206538,"journal":{"name":"1st Portuguese Biomedical Engineering Meeting","volume":"688 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132038533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Multicriteria model to allocate human resources in community care programmes 在社区护理计划中分配人力资源的多准则模式
1st Portuguese Biomedical Engineering Meeting Pub Date : 2011-03-01 DOI: 10.1109/ENBENG.2011.6026087
T. Rodrigues, M. Oliveira, A. B. de Sá
{"title":"Multicriteria model to allocate human resources in community care programmes","authors":"T. Rodrigues, M. Oliveira, A. B. de Sá","doi":"10.1109/ENBENG.2011.6026087","DOIUrl":"https://doi.org/10.1109/ENBENG.2011.6026087","url":null,"abstract":"Presently, healthcare organizations are facing shortage of human and financial resources, demanding decisions about how to allocate the available resources while pursuing multiple objectives. This is the case of the Group of Primary Care Centres (GPCC) of Northern Lisbon, which faces the challenge of prioritizing community care programmes and decide which programmes should be funded. The methods available to help decision-makers in prioritizing programmes typically do not account for the multiple objectives of the GPCC and furthermore do not present transparent and rational processes. This paper aims to create a multicriteria resource allocation model — MARCCO (Multi-criteria Model to Allocate Human Resources in Community Care PrOgrammes) — to allocate human resources to community care programmes. MARCCO's results helped and supported the GPCC in prioritizing these programmes and in understanding how the allocation of resources can add value to the organization.","PeriodicalId":206538,"journal":{"name":"1st Portuguese Biomedical Engineering Meeting","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129654180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Computational tools for assessing cardiovascular variability 评估心血管变异性的计算工具
1st Portuguese Biomedical Engineering Meeting Pub Date : 2011-03-01 DOI: 10.1109/ENBENG.2011.6026082
C. Tavares, R. Martins, S. Laranjo, I. Rocha
{"title":"Computational tools for assessing cardiovascular variability","authors":"C. Tavares, R. Martins, S. Laranjo, I. Rocha","doi":"10.1109/ENBENG.2011.6026082","DOIUrl":"https://doi.org/10.1109/ENBENG.2011.6026082","url":null,"abstract":"The analysis of heart rate variability is nowadays a common method for noninvasive evaluation of the autonomic nervous system integrity. In this work we developed an integrated and modular system — FisioSinal — capable of clinical and laboratorial evaluation of the behavior of autonomic nervous system using cardiovascular signals in humans and animal models. The computational tools that were included seek to cover the currently most validated methodologies: stochastic analysis, descriptive statistics, auto-regression, fast Fourier transform, discrete Wavelets transform and baroreflex sensitivity index. Due to its limitations, we developed and validated a new analytical tool based on Hilbert-Huang transform. FisioSinal was validated and tested by analyzing a synthesized signal. The clinical applicability was demonstrated through an analysis of the cardiovascular signals of a normal individual and a patient with paroxysmal atrial fibrillation, undergoing autonomic a provocation maneuver.","PeriodicalId":206538,"journal":{"name":"1st Portuguese Biomedical Engineering Meeting","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130586571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 19
Monitoring bacterial processes by Fourier transform infrared spectroscopy: Helicobacter pylori drug inactivation and plasmid bioproduction in recombinant Escherichia coli cultures 傅立叶变换红外光谱监测细菌过程:重组大肠杆菌培养中幽门螺杆菌药物失活和质粒生物生产
1st Portuguese Biomedical Engineering Meeting Pub Date : 2011-03-01 DOI: 10.1109/ENBENG.2011.6026090
T. Scholz, V. V. Lopes, C. Calado
{"title":"Monitoring bacterial processes by Fourier transform infrared spectroscopy: Helicobacter pylori drug inactivation and plasmid bioproduction in recombinant Escherichia coli cultures","authors":"T. Scholz, V. V. Lopes, C. Calado","doi":"10.1109/ENBENG.2011.6026090","DOIUrl":"https://doi.org/10.1109/ENBENG.2011.6026090","url":null,"abstract":"Fourier transform infrared (FTIR) spectroscopy is evaluated as a tool to monitor two bacterial processes: strain discrimination and drug inactivation studies with the gastric pathogen Helicobacter pylori and the plasmid production process based on high-density cultures of recombinant Escherichia coli. Results show, that after evaluation of different incubation conditions of H.pylori with the drug model, the application of principal component analysis to the FTIR spectra assembles the samples into clusters which can be related with the minimal inhibitory concentration. Morever, the same methodology applied to FTIR spectra from 12 different strains can be used to distinguish them. For the E.coli cultures it is possible to estimate the concentration of relevant bioprocess monitoring variables, such as plasmid, biomass, and carbon sources (glucose, glycerol, acetate) by using partial least squares (PLS) models based on FTIR spectra.","PeriodicalId":206538,"journal":{"name":"1st Portuguese Biomedical Engineering Meeting","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123812930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Ocular fundus imaging: From structure to function 眼底成像:从结构到功能
1st Portuguese Biomedical Engineering Meeting Pub Date : 2011-03-01 DOI: 10.1109/ENBENG.2011.6026080
P. Serranho, C. Maduro, T. Santos, J. Cunha-Vaz, Rui Bernardes, A. Araújo, S. Barbeiro
{"title":"Ocular fundus imaging: From structure to function","authors":"P. Serranho, C. Maduro, T. Santos, J. Cunha-Vaz, Rui Bernardes, A. Araújo, S. Barbeiro","doi":"10.1109/ENBENG.2011.6026080","DOIUrl":"https://doi.org/10.1109/ENBENG.2011.6026080","url":null,"abstract":"Imaging the ocular fundus, namely the retina, to detect and/or monitor changes over time from the healthy condition is of fundamental importance to assess onset and disease progression and is a valuable tool to understand the basic mechanisms of ocular diseases. Current trends point to the need for less or non-invasive approaches, to the need for detailed (higher spatial and temporal resolution) imaging systems and to the quantification as opposed to qualitative classification of any findings. In this work we present a snapshot of our research by presenting two examples of technical development aiming to obtain structural and function information from the human retina, in vivo, using non-invasive techniques, namely optical coherence tomography imaging. Based on our experience and developed work, we are now starting to bridge the gap to brain imaging as the eye is only the starting point of vision.","PeriodicalId":206538,"journal":{"name":"1st Portuguese Biomedical Engineering Meeting","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131186941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Process intensification platforms for application in bioengineering 生物工程应用的过程强化平台
1st Portuguese Biomedical Engineering Meeting Pub Date : 2011-03-01 DOI: 10.1109/ENBENG.2011.6026048
M. Marques, P. Fernandes, Carla C. C. R. de Carvalho
{"title":"Process intensification platforms for application in bioengineering","authors":"M. Marques, P. Fernandes, Carla C. C. R. de Carvalho","doi":"10.1109/ENBENG.2011.6026048","DOIUrl":"https://doi.org/10.1109/ENBENG.2011.6026048","url":null,"abstract":"The work presented reports the use of small scale reactors, with 15 mL-3 μL of volume, in bioprocesses. This field of research is of acknowledged relevance, since the rational use of small scale reactors is contributing to speed up process development in several areas of biotechnology, in particular due to the possibility of carrying out high throughput assays. Small scale reactors are available in different working volumes, configurations and architectures. These bioreactors are currently used in a wide array of applications, from cell screening to process optimization. The present work is focused on three major application areas, namely steroid biotransformations, siderophore production and screening of antibacterial agents. Results have shown the reliability of these platforms as suitable alternatives of traditional reactors and as screening tools. Fully automated platforms with monitoring and control devices are on the pipeline to further take advantage of the high throughput capability.","PeriodicalId":206538,"journal":{"name":"1st Portuguese Biomedical Engineering Meeting","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132912540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Lab-on-a-chip using acoustic streaming for mixing and pumping fluids 芯片实验室利用声学流来混合和泵送流体
1st Portuguese Biomedical Engineering Meeting Pub Date : 2011-03-01 DOI: 10.1109/ENBENG.2011.6026068
V. Cardoso, S. Catarino, S. Lanceros‐Méndez, G. Minas
{"title":"Lab-on-a-chip using acoustic streaming for mixing and pumping fluids","authors":"V. Cardoso, S. Catarino, S. Lanceros‐Méndez, G. Minas","doi":"10.1109/ENBENG.2011.6026068","DOIUrl":"https://doi.org/10.1109/ENBENG.2011.6026068","url":null,"abstract":"The research team is focused on lab-on-a-chip devices for clinical applications, with on-chip integration of electronic circuits, optical filters and (bio)sensors. An example of the work is a lab-on-a-chip where acoustic streaming technique is used to promote the mixing and the pumping of the fluids inside microchannels. The transducer that generates the acoustic streaming is based on a piezoelectric polymer, processed to be functionally graded for, in conjunction with the signal applied to the transducers, being able to control the movement and heating of the fluids. A highly selective optical interference filter co-integrated in CMOS allows the use of only a white light source when spectrophotometry is used as the detection technique, resulting in an actually portable device.","PeriodicalId":206538,"journal":{"name":"1st Portuguese Biomedical Engineering Meeting","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134022116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Exploring embryonic stem cell fate using cellular microarrays 利用细胞微阵列技术探索胚胎干细胞的命运
1st Portuguese Biomedical Engineering Meeting Pub Date : 2011-03-01 DOI: 10.1109/ENBENG.2011.6026038
Tiago G Fernandes, M. M. Diogo, J. Dordick, J. Cabral
{"title":"Exploring embryonic stem cell fate using cellular microarrays","authors":"Tiago G Fernandes, M. M. Diogo, J. Dordick, J. Cabral","doi":"10.1109/ENBENG.2011.6026038","DOIUrl":"https://doi.org/10.1109/ENBENG.2011.6026038","url":null,"abstract":"This work addresses the development of artificial cellular niches for studying the mechanisms that affect stem cell pluripotency, and aims at contributing to a better understanding of the cellular and molecular events that regulate stem cell functions. Embryonic stem (ES) cells were used as model systems to establish in vitro artificial microenvironments that better mimic the extracellular matrix. Microscale-based systems were designed for 3D culture of these cell types, and high-throughput screening platforms were developed to unveil the effects of complex interactions on cell fate. Particularly, We have developed a novel 3D cellular microarray platform to enable the rapid and efficient tracking of stem cell fate and quantification of specific stem cell markers. Our results revealed that this platform is suitable for studying the expansion of mouse ES cells as they retain their pluripotent and undifferentiated state. In addition to the influence of mechanical and matrix-related responses, the effects of microenvironmental conditions (e.g. small molecules and growth factors) were also analyzed due to their capacity of modulating intracellular pathways. This novel platform is a powerful new tool for investigating cellular mechanisms involved in stem cell expansion and differentiation and provides the basis for rapid identification of signals and conditions that can be used to direct cellular responses.","PeriodicalId":206538,"journal":{"name":"1st Portuguese Biomedical Engineering Meeting","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124497756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A RNomics-based strategy identifies regulatory small RNAs in Burkholderia cepacia complex 基于rnomics的策略识别洋葱伯克霍尔德菌复合体中的调节小rna
1st Portuguese Biomedical Engineering Meeting Pub Date : 2011-03-01 DOI: 10.1109/ENBENG.2011.6026035
C. G. Ramos, S. A. Sousa, A. M. Grilo, Paulo J da Costa, J. Feliciano, J. Leitão
{"title":"A RNomics-based strategy identifies regulatory small RNAs in Burkholderia cepacia complex","authors":"C. G. Ramos, S. A. Sousa, A. M. Grilo, Paulo J da Costa, J. Feliciano, J. Leitão","doi":"10.1109/ENBENG.2011.6026035","DOIUrl":"https://doi.org/10.1109/ENBENG.2011.6026035","url":null,"abstract":"Regulatory small non-coding RNAs (sRNAs) are know to be involved in bacterial virulence, most often exerting its function in a Hfq-dependent fashion. Burkholderia cepacia complex (Bcc) bacteria are important human opportunistic pathogens, that possess exceptionally large and complex genomes (∼7000 genes) comprising roughly 8 Mb. Within their genomes, it has been predicted in silico 213 sRNAs. Bcc are unique among human pathogens by encoding two distinct and functional Hfq-like proteins. In this work, we describe a strategy based on co-immunoprecipitation of sRNAs with Hfq-like proteins, the cloning and identification of the sRNAs, showing the wide array of possibilities that this RNomics approach endows the researcher for sRNA discovery.","PeriodicalId":206538,"journal":{"name":"1st Portuguese Biomedical Engineering Meeting","volume":"163 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123462606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
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