检索结果-南通市图书馆

Local wavelet-based filtering of electromyographic signals to eliminate the electrocardiographic-induced artifacts in patients with spinal cord injury

引用

Journal of Biomedical Science and Engineering 2013年第7期6卷 1-13页

作者： Matthew Nitzken Nihit Bajaj Sevda Aslan Georgy Gimel’farb Ayman El-Baz Alexander Ovechkin BioImaging Laboratory Bioengineering Department University of Louisville Louisville USA Department of Computer Science The University of Auckland Auckland New Zealand Department of Neurological Surgery University of Louisville Louisville USA Frazier Rehab Institute Louisville USA Department of Neurological Surgery University of Louisville Louisville USA frazier rehab institute Louisville USA

Surface Electromyography (EMG) is a standard method used in clinical practice and research to assess motor function in order to help with the diagnosis of neuromuscular pathology in human and animal models. EMG recorded from trunk muscles involved in the activity of breathing can be used as a direct measure of respiratory motor function in patients with spinal cord injury (SCI) or other disorders associated with motor control deficits. However, EMG potentials recorded from these muscles are often contaminated with heart-induced electrocardiographic (ECG) signals. Elimination of these artifacts plays a critical role in the precise measure of the respiratory muscle electrical activity. This study was undertaken to find an optimal approach to eliminate the ECG artifacts from EMG recordings. Conventional global filtering can be used to decrease the ECG-induced artifact. However, this method can alter the EMG signal and changes physiologically relevant information. We hypothesize that, unlike global filtering, localized removal of ECG artifacts will not change the original EMG signals. We develop an approach to remove the ECG artifacts without altering the amplitude and frequency components of the EMG signal by using an externally recorded ECG signal as a mask to locate areas of the ECG spikes within EMG data. These segments containing ECG spikes were decomposed into 128 sub-wavelets by a custom-scaled Morlet Wavelet Transform. The ECG-related subwavelets at the ECG spike location were removed and a de-noised EMG signal was reconstructed. Validity of the proposed method was proven using mathematical simulated synthetic signals and EMG obtained from SCI patients. We compare the Rootmean Square Error and the Relative Change in Variance between this method, global, notch and adaptive filters. The results show that the localized wavelet-based filtering has the benefit of not introducing error in the native EMG signal and accurately removing ECG artifacts from EMG signals.

关键词： EMG De-Noising ECG Local Wavelet Filtering

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Beyond cotton and polyester: An evaluation of emerging feedstocks and conversion methods for the future of fashion industry

引用

Journal of Bioresources and Bioproducts 2024年第2期9卷 130-159页

作者： Ryen M.frazier Keren A.Vivas Ivana Azuaje Ramon Vera Alonzo Pifano Naycari Forfora Hasan Jameel Ericka Ford Joel J.Pawlak Richard Venditti Ronalds Gonzalez Department of Forest Biomaterials North Carolina State UniversityRaleighNC 27695USA Department of Textile Engineering Chemistry and ScienceThe Nonwovens InstituteNorth Carolina State UniversityRaleighNC 27695USA

As the global population grows,the demand for textiles is increasing rapidly.However,this puts immense pressure on manufacturers to produce more fiber.While synthetic fibers can be pro-duced cheaply,they have a negative impact on the environment.On the other hand,fibers from wool,sisal,fique,wood pulp(viscose),and man-made cellulose fibers(MMCFs)from cotton can-not alone meet the growing fiber demand without major stresses on land,water,and existing markets using these materials.With a greater emphasis on transparency and circular economy practices,there is a need to consider natural non-wood alternative sources for MMCFs to supple-ment other fiber types.However,introducing new feedstocks with different compositions may require different biomass conversion methods.Therefore,based on existing work,this review ad-dresses the technical feasibility of various alternative feedstocks for conversion to textile-grade fibers.First,alternative feedstocks are introduced,and then conventional(dissolving pulp)and emerging(fibrillated cellulose and recycled material)conversion technologies are evaluated to help select the most suitable and promising processes for these emerging alternative sources of cellulose.It is important to note that for alternative feedstocks to be adopted on a meaningful scale,high biomass availability and proximity of conversion facilities are critical factors.In North America,soybean,wheat,rice,sorghum,and sugarcane residues are widely available and most suitable for conventional conversion through various dissolving pulp production methods(pre-hydrolysis kraft,acid sulfite,soda,SO2-ethanol-water,and potassium hydroxide)or by emerging cellulose fibrillation methods.While dissolving pulp conversion is well-established,fibrillated cel-lulose methods could be beneficial from cost,efficiency,and environmental perspectives.Thus,the authors strongly encourage more work in this growing research area.However,conducting thorough cost and sustainability assessments is important to determine the best feedstock a

关键词： Non-wood Residue Regenerated cellulose Dissolving pulp Man-made cellulose fiber Apparel textile

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Impact of Social Determinants of Health on Self-Perceived Resilience: An Exploratory Study of Two Cohorts of Adults with Congenital Heart Disease

引用

Congenital Heart Disease 2024年第1期19卷 33-48页

作者： Albert Osom Krysta S.Barton Katie Sexton Lyndia Brumback Joyce P.Yi-frazier Abby R.Rosenberg Ruth Engelberg Jill M.Steiner Department of Biostatistics University of WashingtonSeattleWA98195USA Biostatistics Epidemiology and Analytics for Research(BEAR)Core Seattle Children’s Research InstituteSeattleWA98101USA College of Medicine University of WashingtonSeattleWA98195USA Center for Clinical and Translational Research Seattle Children’s Research InstituteSeattleWA98101USA Department of Psychosocial Oncology and Palliative Care Dana-Farber Cancer InstituteDepartment of MedicineBoston Children’s HospitalBostonMA02215USA Department of Pediatrics Harvard Medical SchoolBostonMA02215USA Division of Pulmonary Critical Care and Sleep MedicineDepartment of Medicine&Cambia Palliative Care Center of ExcellenceUniversity of WashingtonHarborview Medical CenterSeattleWA98104USA Division of Cardiology Department of Medicine&Cambia Palliative Care Center of ExcellenceUniversity of WashingtonSeattleWA98195USA

Social determinants of health(SDOH)affect quality of life.We investigated SDOH impacts on self-perceived resilience among people with adult congenital heart disease(ACHD).Secondary analysis of data from two com-plementary studies:a survey study conducted May 2021–June 2022 and a qualitative study conducted June 2020–August 2021.Resilience was assessed through CD-RISC10 score(range 0–40,higher scores reﬂect greater self-perceived resilience)and interview responses.Sociodemographic and SDOH(education,employment,living situa-tion,monetary stability,ﬁnancial dependency,area deprivation index)data were collected by healthcare record review and self-report.We used linear regression with robust standard errors to analyze survey data and performed a thematic analysis of interview data.Survey participants(N=127)mean age was 42±14 years;51%were female,87%white.ACHD was moderate(75%)or complex(25%);41%functional class C or D.Resilience(mean 30±7)varied by monetary stability:compared to people with difﬁculty paying bills,resilience was 15.0 points higher(95%CI:6.9–23.1,p<0.001)for people reporting having enough money and 14.2 points higher(95%CI:5.9–22.4,p=0.001)for those reporting just enough money.Interview participants’(N=25)mean age was 32 years(range 22–44);52%were female,72%white.ACHD was moderate(56%)or complex(44%);76%functional class C or D.Participants discussed factors affecting resilience aligned with each of the major SDOH,prominently,economic stability and healthcare access and quality.Financial stability may be important for supporting self-perceived resi-lience in ACHD.This knowledge can inform the development of resilience interventions for this population.

关键词： Social determinants of health adult congenital heart disease resilience ﬁnancial stability

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Shorebird patches as fingerprints of fractal coastline fluctuations due to climate change

引用

Ecological Processes 2012年第1期1卷 33-49页

作者： Matteo Convertino Adam Bockelie Gregory A Kiker Rafael Munoz-Carpena Igor Linkov Department of Agricultural and Biological Engineering-IFAS University of FloridaGainesvilleFLUSA Contractor at the Risk and Decision Science Team Environmental LaboratoryEngineer Research and Development CenterUS Army Corps of EngineersConcordMAUSA Florida Climate institute UF-FSUc/o Frazier Rogers HallGainesvilleFL USA Department of Civil and Environmental Engineering Massachusetts Institute of TechnologyCambridgeMAUSA Department of Earth Atmosphericand Planetary ScienceMassachusetts Institute of TechnologyCambridgeMAUSA Risk and Decision Science Team Environmental LaboratoryEngineer Research and Development CenterUS Army Corps of EngineersConcordMAUSA Department of Engineering and Public Policy Carnegie Mellon UniversityPittsburghPAUSA.

Introduction:The Florida coast is one of the most species-rich ecosystems in the world.This paper focuses on the sensitivity of the habitat of threatened and endangered shorebirds to sea level rise induced by climate change,and on the relationship of the habitat with the coastline evolution.We consider the resident Snowy Plover(Charadrius alexandrinus nivosus),and the migrant Piping Plover(Charadriusmelodus)and Red Knot(Calidris canutus)along the Gulf Coast of Mexico in Florida.Methods:We analyze and model the coupled dynamics of habitat patches of these imperiled shorebirds and of the shoreline geomorphology dictated by land cover change with consideration of the coastal wetlands.The land cover is modeled from 2006 to 2100 as a function of the A1B sea level rise scenario rescaled to 2 m.Using a maximum-entropy habitat suitability model and a set of macroecological criteria we delineate breeding and wintering patches for each year simulated.Results:Evidence of coupled ecogeomorphological dynamics was found by considering the fractal dimension of shorebird occurrence patterns and of the coastline.A scaling relationship between the fractal dimensions of the species patches and of the coastline was detected.The predicted power law of the patch size emerged from scale-free habitat patterns and was validated against 9 years of observations.We predict an overall 16%loss of the coastal landforms from inundation.Despite the changes in the coastline that cause habitat loss,fragmentation,and variations of patch connectivity,shorebirds self-organize by preserving a power-law distribution of the patch size in time.Yet,the probability of finding large patches is predicted to be smaller in 2100 than in 2006.The Piping Plover showed the highest fluctuation in the patch fractal dimension;thus,it is the species at greatest risk of decline.Conclusions:We propose a parsimonious modeling framework to capture macroscale ecogeomorphological patterns of coastal ecosystems.Our results suggest the potential use of the fractal dimension o

关键词： Land cover change Coastal wetlands Coastline complexity Fractal dimension Habitat suitability Patches Sea level rise

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Aerodynamic Modeling and Parameter Estimation from QAR Data of an Airplane Approaching a High-altitude Airport

引用

Chinese Journal of Aeronautics 2012年第3期25卷 361-371页

作者： WANG Qing WU Kaiyuan ZHANG Tianjiao KONG Yi'nan QIAN Weiqi State Key Laboratory of Aerodynamics.China Aerodynamics Research and Development Center Mianvang 621000.China Computational Aerodynamics institute China Aerodynamics Research and Development Center Mianyang 621000 China Seientifie Research Base of Civil Aviation Flight Technology and Safety Guanghan 618307China

Aerodynamic modeling and parameter estimation from quick accesses recorder （QAR） data is an important technical way to analyze the effects of highland weather conditions upon aerodynamic characteristics of airplane. It is also an essential content of flight accident analysis. The related techniques are developed in the present paper, including the geometric method for angle of attack and sideslip angle estimation, the extended Kalman filter associated with modified Bryson-frazier smoother （EKF-MBF） method for aerodynamic coefficient identification, the radial basis function （RBF） neural network method for aerodynamic mod- eling, and the Delta method for stability/control derivative estimation. As an application example, the QAR data of a civil air- plane approaching a high-altitude airport are processed and the aerodynamic coefficient and derivative estimates are obtained. The estimation results are reasonable, which shows that the developed techniques are feasible. The causes for the distribution of aerodynamic derivative estimates are analyzed. Accordingly, several measures to improve estimation accuracy are put forward.

关键词： civil airplane aerodynamics QAR data aerodynamic modeling aerodynamic parameter estimation flight safety EKF-MBF method neural network

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Wavefront-optimized surface retreatments of refractive error following previous laser refractive surgery: a retrospective study

引用

Eye and Vision 2016年第1期3卷 22-28页

作者： Kevin M.Broderick Rose K Sia Denise S.Ryan Richard D.Stutzman Michael J.Mines Travis C.frazier Mark F.Torres Kraig S.Bower Ophthalmology Service Walter Reed National Military Medical Center8901 Wisconsin AvenueBethesdaMD 20814USA Warfighter Refractive Eye Surgery Program and Research Center Ft.BelvoirVAUSA Ophthalmology Service Madigan Army Medical CenterTacomaWAUSA The Wilmer Eye institute Johns Hopkins UniversityBaltimoreMDUSA

Background:Retreatments are sometimes necessary to correct residual or induced refractive errors following refractive surgery.Many different combinations of primary treatment methods and retreatment techniques have been studied,however,few studies have investigated wavefront-optimized(WFO)technology for retreatment following primary refractive surgery.This study aimed to report the outcomes of WFO photorefractive keratectomy(PRK)retreatments of refractive error following previous laser refractive surgery with PRK,laser in situ keratomileusis(LASIK),or laser-assisted subepithelial keratectomy(LASEK).Methods:We reviewed records of patients who underwent WFO PRK retreatments using the Allegretto Wave Eye-Q 400 Hz Excimer Laser System(Alcon Surgical)between January 2008 and April 2011 at Walter Reed Army Medical Center and Madigan Army Medical Center.Outcomes were recorded in terms of uncorrected distance visual acuity(UDVA),manifest refraction spherical equivalent(MRSE),corrected distance visual acuity(CDVA),and complications at 1 month(M),3 M,and 6 M post-op.Results:Seventy-eight patients(120 eyes)underwent WFO PRK retreatment during the study period.Primary surgery was surface ablation in 87 eyes(78 PRK,9 LASEK)and LASIK in 33 eyes.The mean spherical equivalent before retreatment was−0.79±0.94 D(−3.00 to 1.88 D).UDVA was≥20/20 in 69 eyes(60.0%)at 1 M,54 eyes(71.1%)at 3 M,and 27 eyes(73.0%)at 6 M follow-up.MRSE was within±0.50 D of emmetropia in 78 eyes(67.8%)at 1 M,59 eyes(77.6%)at 3 M,and 25 eyes(67.6%)at 6 M follow-up.CDVA was maintained within±1 line of pre-op in 113 of 115 eyes(98.3%)at 1 M,74 of 76 eyes(97.4%)at 3 M,and 37 eyes(100%)at 6 M follow-up.Conclusion:Although follow-up was limited beyond 3 M,WFO PRK retreatments in patients with residual refractive error may be a safe and effective procedure.Further studies are necessary to determine the long-term safety and stability of outcomes.

关键词： Wavefront-optimized PRK LASIK LASEK Retreatment Enhancement

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nature:研究首次证实帕金森病部分上是一种自身免疫疾病

引用

现代生物医学进展 2017年第27期17卷 I0002-I0002页

作者： David Sulzer, Francesca Garretti, Ellen Kanter, Julian Agin-Liebes, Elizabeth Phillips, Simon Mallal David Sulzer, Roy N. Alcalay, Lucien Cote, Christopher Liong, Elizabeth Phillips, Simon Mallal David Sulzer Curtis McMurtrey, William H. Hildebrand Xiaobo Mao, Valina L. Dawson, Ted M. Dawson Xiaobo Mao, Valina L. Dawson, Ted M. Dawson Valina L. Dawson Valina L. Dawson, Ted M. Dawson Ted M. Dawson Carla Oseroff, John Pham, John Sidney, Myles B. Dillon, Chelsea Carpenter, Daniela Weiskopf, Bjoern Peters, April frazier, Cecilia S. Lindestam Arlehamn, Alessandro Sette Elizabeth Phillips, Simon Mallal Departments of Psychiatry Columbia University Division of Molcular Therapeutics New York State Psychiatric Institute New York New York 10032 USA Department of Neurology Columbia University New York New York 10032 USA Department of Pharmacology Columbia University New York New York 10032 USA Department of Microbiology and Immunology University of Oklahoma Oklahoma City Oklahoma 73104 USA Neuroregeneration and Stem Cell Program Institute for Cell Engineering and the Department of Neurology Johns Hopkins University School of Medicine Baltimore Maryland 21205 USA Adrienne Helis Malvin Medical Research Foundation New Orleans Louisiana 70130-2685 USA Department of Physiology Johns Hopkins University School of Medicine Baltimore Maryland 21205 USA Solomon H. Snyder Department of Neuroscience Johns Hopkins University School of Medicine Baltimore Maryland 21205 USA Department of Pharmacology & Molecular Sciences Johns Hopkins University School of Medicine Baltimore Maryland 21205 USA Division of Vaccine Discovery La Jolla Institute for Allergy and Immunology La Jolla California 92037 USA institute for Immunology and Infectious Diseases Murdoch University Perth Western Australia 6150 Australia Vanderbilt University School of Medicine Nashville Tennessee 37235 USA

帕金森病是一种神经退行性疾病。这种疾病的一种关键特征是受损的a-突触核蛋白（alpha-synuclein）在帕金森病患者体内的一种被称作多巴胺能神经元的脑细胞中堆积。在一项新的研究中，来自美国哥伦比亚大学医学中心和拉荷亚过敏症与免... 详细信息

帕金森病是一种神经退行性疾病。这种疾病的一种关键特征是受损的a-突触核蛋白（alpha-synuclein）在帕金森病患者体内的一种被称作多巴胺能神经元的脑细胞中堆积。在一项新的研究中，来自美国哥伦比亚大学医学中心和拉荷亚过敏症与免疫学研究所等研究机构的研究人员发现首个直接的证据证实自身免疫反应在帕金森病中发挥着作用。

关键词：自身免疫疾病帕金森病神经退行性疾病多巴胺能神经元哥伦比亚大学免疫反应研究人员研究机构

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：