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detection and identification of S1 and S2 heart sounds using wavelet decomposition method

International Journal of Biomathematics 2015年第6期8卷 141-155页

作者： Ali Tavakoli Golpaygani Nahid Abolpour Kamran Hassani d. john doyle Biomedical Engineering departmentFaculty of Electrical Mechanical and Construction Engineering Standard Research Institute Karaj Iran department of Physics and Biomedical EngineeringShiraz University of Medical Sciences Shiraz Iran department of Biomechanics Science and Research Branch Islamic Azad University Tehran Iran department of General AnesthesiologyAnesthesiology Institute Cleveland Clinic Abu Dhabi Abu Dhabi UAE

Phonocardiogram （PCG）, the digital recording of heart sounds is becoming increasingly popular as a primary detection system for diagnosing heart disorders and it is relatively inexpensive. Electrocardiogram （ECG） is used during the PCG in order to identify the systolic and diastolic parts manually. In this study a heart sound segmentation algorithm has been developed which separates the heart sound signal into these parts automa- tically. This study was carried out on 100 patients with normal and abnormal heart sounds. The algorithm uses discrete wavelet decomposition and reconstruction to pro- duce PCG intensity envelopes and separates that into four parts： the first heart sound, the systolic period, the second heart sound and the diastolic period. The performance of the algorithm has been evaluated using 14,000 cardiac periods from 100 digital PCG recordings, including normal and abnormal heart sounds. In tests, the algorithm was over93% correct in detecting the first and second heart sounds. The presented automatic seg- mentation Mgorithm using w^velet decomposition and reconstruction to select suitable frequency band for envelope calculations has been found to be effective to segment PCG signals into four parts without using an ECG.

关键词： Phonocardiography auscultation murmurs wavelet decomposition waveletreconstruction segmentation.

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Linewidth narrowing in self-injection-locked on-chip lasers

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Light(Science & Applications) 2023年第10期12卷 2074-2083页

作者： Emad Alkhazraji Weng W.Chow Frédéric Grillot john E.Bowers Yating Wan Integrated Photonics Lab King Abdullah University of Science and TechnologyThuwal 23955Saudi Arabia Sandia National Laboratories AlbuquerqueNM 87185-1086USA LTCI Télécom ParisInstitut Polytechnique de Paris91120 PalaiseauFrance department of Electronic and Computer Engineering University of California-Santa BarbaraSanta BarbaraCA 93106USA

Stable laser emission with narrow linewidth is of critical importance in many applications,including coherent communications,LIdAR,and remote *** this work,the physics underlying spectral narrowing of self-injection-locked on-chip lasers to Hz-level lasing linewidth is investigated using a composite-cavity *** integrated III–V/SiN lasers operating with quantum-dot and quantum-well active regions are analyzed with a focus on the effects of carrier quantum *** intrinsic differences are associated with gain saturation and carrier-induced refractive index,which are directly connected with 0-and 2-dimensional carrier densities of *** from parametric studies are presented for tradeoffs involved with tailoring the linewidth,output power,and injection current for different device *** both quantum-well and quantum-dot devices show similar linewidth-narrowing capabilities,the former emits at a higher optical power in the self-injection-locked state,while the latter is more ***,a multi-objective optimization analysis is provided to optimize the operation and design *** the quantum-well laser,minimizing the number of quantum-well layers is found to decrease the threshold current without significantly reducing the output *** the quantum-dot laser,increasing the quantum-dot layers or density in each layer increases the output power without significantly increasing the threshold *** findings serve to guide more detailed parametric studies to produce timely results for engineering design.

关键词： narrowing injection quantum

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Leading Approaches to Vascularize Kidney Constructs in Tissue Engineering

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Engineering 2022年第12期19卷 117-127页

作者： diana S.Lim john d.Jackson Anthony Atala James J.Yoo Wake Forest Institute for Regenerative Medicine Wake Forest University School of MedicineMedical Center BoulevardNC 27157USA

There is an unprecedented need for new treatments for renal failure,as the incidence of this disease is increasing disproportionately to advancements in *** treatments are limited by the availability of viable organs,for which there is a worldwide *** treatment modalities also require a substantial amount of infrastructure,significantly limiting the access to care in most *** tissue engineering approaches promise to develop alternative solutions that address many of the inadequacies in current *** many advancements have been made—primarily in the past decade—in biofabrication and whole-organ tissue engineering,many challenges *** major hindrance to the progress of current tissue engineering approaches is establishing successful vascularization of developed engineered tissue *** review focuses on the recent advancements that address the vascular challenge,including the biofabrication of vasculature,whole-organ engineering through decellularization and recellularization approaches,microscale organogenesis,and vascularization using organoids in the context of kidney tissue *** also highlight the specific challenges that remain in developing successful strategies capable of clinical translation.

关键词： Kidney Vascularization Tissue engineering Biofabrication Organoids

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Challenges and opportunities in improving left ventricular remodelling and clinical outcome following surgical and trans-catheter aortic valve replacement

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Frontiers of Medicine 2021年第3期15卷 416-437页

作者： Xu Yu Jin Mario Petrou Jiang Ting Hu Ed d Nicol john R Pepper Surgical Echo-Cardiology Services Oxford Heart CentreJohn Radcliffe HospitalOxford University Hospitals NHS Foundation TrustOxford OX39DUUK Cardiac Surgical Physiology and Genomics Group Nuffield Division of Clinical Laboratory SciencesRadcliffe Department of MedicineUniversity of OxfordOxford OX39DUUK department of Cardiac Surgery Royal Brompton HospitalLondon SW36NPUK National Heart and Lung Institute Imperial College LondonLondon SW36LYUK NIHR Imperial Biomedical Research Centre London W21NYUK department of Cardiology Royal Brompton HospitalLondon SW36NPUK

Over the last half century,surgical aortic valve replacement(SAVR)has evolved to offer a durable and efficient valve haemodynamically,with low procedural complications that allows favourable remodelling of left ventricular(LV)structure and *** latter has become more challenging among elderly patients,particularly following trans-catheter aortic valve implantation(TAVI).Precise understanding of myocardial adaptation to pressure and volume overloading and its responses to valve surgery requires comprehensive assessments from aortic valve energy loss,valvular-vascular impedance to myocardial activation,force-velocity relationship,and myocardial *** hypertrophy and myocardial fibrosis remains as the structural and morphological focus in this *** intervention in asymptomatic aortic stenosis or regurgitation along with individualised management of hypertension and atrial fibrillation is likely to improve patient *** pacing via the His-Purkinje system for conduction abnormalities,further reduction in para-valvular aortic regurgitation along with therapy of angiotensin receptor blockade will improve patient outcome by facilitating hypertrophy regression,LV coordinate contraction,and global vascular *** leaflet thromboses require anticoagulation while impaired access to coronary ostia risks future TAVI-in-TAVI or coronary *** comparable long-term durability and the resolution of TAVI related complications become available,SAVR remains the first choice for lower risk younger patients.

关键词： surgical aortic valve replacement trans-catheter aortic valve implantation left ventricular hypertrophy and fibrosis myocardial force-velocity relationship His-Purkinje pacing renin-angiotensin system inhibitors coronary access impairment

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dietary analysis of Homonota darwini (Squamata:Gekkonidae) in Northern Patagonia

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Current Zoology 2010年第4期56卷 406-410页

作者： Marcelo E.KUN Carla PIANTONI john d.KRENZ Nora R.IBARGüENGOYTíA departamento de Zoología Centro Regional Universitario Bariloche Universidad del Comahue Unidad Postal Universidad del Comahue Smithsonian Institution NHB MRC 163 department of Biological Sciences Minnesota State University departamento de Zoologia Centro Regional Universitario Bariloche Universidad del Comahue Unidad Postal Universidad del Comahue Instituto de Investigación en diversidad y Medio Ambiente (INIBIOMA) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)

Our study investigated the diet of the southernmost gecko in the world, Homonota darwini. Fifty-three specimens were captured during spring and summer in four locations in Patagonia, Argentina. The stomach contents of the specimens were identified, and we tbund that prey consisted of six main groups： Coleoptera, Hymenoptera, Homoptera and Araneae, and the adults and larvae of moth Lepidoptera. Lepidoptera was the major dietary component. The presence of ants and moths as common prey suggests an ambush feeding strategy. In spring, females consumed more ants than males although no other dietary differences between males and females were evident. We tbund nine geckos with empty stomachs and six parasitized by nematodes. Presence of empty stomachs corroborates previous observations of other nocturnal geckos and non-gecko lizards. Reduced foraging success of nocturnal lizards could be due to difficulty in prey detection due to dim light, reduced or erratic activity of insect prey at night, or shorter activity times of geckos relative to diurnal success. Sex and season were not associated with the incidence of empty stomachs. Principal component analysis showed that four food alternatives correlated with season. The constraint of nocturnality, coupled with low night-time temperatures restricting feeding to only a few hours after sunset, appear to have caused a generality of diet which may limit energy acquisition. We conclude that H. darwini is an arthropod generalist and likely an ambush forager, as are many other nocturnal gekkonids

关键词： Nocturnal lizards diet Gekkonidae Patagonia PCA

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design and simulation of self-powered radio frequency identification (RFId) tags for mobile temperature monitoring

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Science China(Technological Sciences) 2013年第1期56卷 1-7页

作者： CHU HeQun WU GuangMin CHEN JianMing FEI Fei MAI john d LI Wen J MEMS Laboratory Department of Physics Faculty of Science Kunming University of Science and Technology department of Mechanical and Biomedical Engineering City University of Hong Kong

This paper presents a design for a self-powered radio frequency identification (RFId) tag with a thin film bulk acoustic reso- nating piezoelectric power supply (PPS), which can be used for portable remote temperature monitoring. We call this system a PPS-RFId for short. The RFId systems have been found to have many applications in the internet of things (IOT) in the past decade. But semi-active RFId tags require an onboard battery which limits their applications in many fields. For these reasons, our research focuses on power sources for the RFId tags. This paper emphasizes the circuit design and simulation of PPS. In our tests, 0.283 mW was generated by PPS at 1 Hz vibration by a 650 N impact force. The results showed that the integrated PPS could supply sufficient power for the designed PPS-RFId tag. The PPS-RFId tag can be widely used for temperature monitoring during mobile transport of perishable items such as medicines or food.

关键词： self-powered radio frequency identification (RFId) piezoelectric temperature monitoring energy harvesting internet of things

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Pyramiding disease resistance genes in elite winter wheat germplasm for Western Canada

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The Crop Journal 2019年第6期7卷 739-749页

作者： AndréLaroche Michele Frick Robert J.Graf Jamie Larsen john d.Laurie Agriculture and Agri-Food Canada Lethbridge Research and Development CentreLethbridgeAlberta T1J 4B1Canada Agriculture and Agri-Food Canada Harrow Research and Development Centre2585 County Road 20HarrowOntario N0R 1G0Canada

We report on pyramiding different disease resistance genes against fungal pathogens in Canadian winter wheat germplasm based on available dNA markers and gene *** resistance represents a safe, economical and ecological method for protecting plants, growers and the health of consumers. Major diseases of wheat on the Canadian Prairies are common bunt, rusts(leaf, stem and stripe) and Fusarium head blight. Over the years markers for resistance genes against these diseases have been identified and used by the international wheat community. We describe markers that we have used to pyramid different resistance genes and indicate their presence in Canadian winter wheat cultivars issued from the winter wheat breeding program at the Agriculture and Agri-Food Canada,Lethbridge Research and development Centre, the only winter wheat breeding program in Western Canada actively delivering new varieties for all regions of the Canadian *** sources of resistance and identities of PCR primers and amplification conditions are indicated to enable the transfer and pyramiding of different resistance(R) genes to breeding lines. We conclude by reviewing new tools for identifying R genes in wheat and indicate how mutagenesis and gene editing can help future efforts to extend the protection offered by known R genes.

关键词： Bunt Gene pyramiding Wheat rusts Marker-assisted selection Triticum aestivum

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Qidong: a crucible for studies on liver cancer etiology and prevention

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Cancer Biology & Medicine 2019年第1期16卷 24-37页

作者： Jianguo Chen Jian Zhu Gaoren Wang john d.Groopman Thomas W.Kensler department of Epidemiology Qidong Liver Cancer Institute department of Epidemiology Tumor Hospital Nantong University department of Environmental Health and Engineering Johns Hopkins Bloomberg School of Public Health Public Health Sciences division Fred Hutchinson Cancer Research Center

Qidong(Jiangsu, China) has been of interest to cancer epidemiologists and biologists because, until recently, it was an endemic area for liver cancer, having amongst the highest incidence rates in the world. The establishment of the Qidong Cancer Registry together with the Qidong Liver Cancer Institute in 1972 has charted the patterns of liver cancer incidence and mortality in a stable population throughout a period of enormous economic, social, and environmental changes as well as of improvements in health care delivery. Updated incidence trends in Qidong are described. Notably, the China age-standardized incidence rate for liver cancer has dropped by over 50% in the past several decades. Molecular epidemiologic and genomic deep sequencing studies have affirmed that infection with hepatitis B virus as well as dietary exposure to aflatoxins through contamination of dietary staples such as corn, and to microcystins–blue-green algal toxins found in ditch and pond water – were likely important etiologic factors that account for the high incidence of liver cancer in this region. Public health initiatives to facilitate universal vaccination of newborns against HBV and to improve drinking water sources in this rural area, as well as economic and social mandates serendipitously facilitating dietary diversity, have led to precipitous declines in exposures to these etiologic factors, concomitantly driving substantive declines in the liver cancer incidence seen now in Qidong. In this regard, Qidong serves as a template for the global impact that a package of intervention strategies may exert on cancer burden.

关键词： Liver cancer incidence hepatitis B virus aflatoxin microcystin screening chemoprevention mutational signature

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Hepatitis B and C infection and liver disease trends among human immunodeficiency virus-infected individuals

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World Journal of Gastroenterology 2011年第14期17卷 1807-1816页

作者： Susan E Buskin Elizabeth A Barash john d Scott david M Aboulafia Robert W Wood Public Health-Seattle and King County WA 98104United States University of Washington SeattleWA 98195United States Harborview Medical Center SeattleWA 98104United States Virginia Mason Medical Center SeattleWA 98101United States

AIM:To examine trends in and correlates of liver disease and viral hepatitis in an human immunodeficiency virus (HIV)-infected cohort. METHOdS:The multi-site adult/adolescent spectrum of HIV-related diseases (ASd) followed 29 490 HIVinfected individuals receiving medical care in 11 U.S. metropolitan areas for an average of 2.4 years,and a total of 69 487 person-years,between 1998 and 2004. ASd collected data on the presentation,treatment,and outcomes of HIV,including liver disease,hepatitis screening,and hepatitis diagnoses. RESULTS:Incident liver disease,chronic hepatitis B virus (HBV),and hepatitis C virus (HCV) were diagnosed in 0.9,1.8,and 4.7 per 100 person-years. HBV and HCV screening increased from fewer than 20% to over 60% during this period of observation (P deaths occurred in 57% of those diagnosed with liver disease relative to 15% overall (P deaths occurred among individuals with a diagnosis of liver disease. despite care guidelines promoting screening and vaccination for HBV and screening for HCV,screening and vaccination were not universally conducted or,if conducted,not documented. CONCLUSION:due to high rates of incident liver disease,viral hepatitis screening,vaccination,and treatment among HIV-infected individuals should be a priority.

关键词： Human immunodeficiency virus Hepatitis B Hepatitis C Liver disease

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Effect of introducing weather parameters on the accuracy of milk production forecast models

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Information Processing in Agriculture 2020年第1期7卷 120-138页

作者： Fan Zhang john Upton Laurence Shalloo Philip Shine Michael d.Murphy department of Process Energy and Transport EngineeringCork Institute of TechnologyCo.CorkIreland Animal and Grassland Research Innovation Centre Teagasc MooreparkCo.CorkIreland

The objective of this study was to analyze the effect of adding meteorological data to the training process of two milk production forecast *** two models chosen were the nonlinear auto-regressive model with exogenous input(NARX)and the multiple linear regression(MLR)*** accuracy of these models were assessed using seven different combinations of precipitation,sunshine hours and soil temperature as additional model training *** data(daily milk yield and days in milk)from 39 pasture-based Holstein-Friesian Irish dairy cows were selected to compare to the model outputs from a central *** models were trained using historical milk production data from three lactation cycles and were employed to predict the total daily milk yield of a fourth lactation cycle for each individual cow over short(10-day),medium(30-day)and long-term(305-day)forecast *** NARX model was found to provide a greater prediction accuracy when compared to the MLR model when predicting annual individual cow milk yield(kg),with R2 values greater than 0.7 for 95.5%and 14.7%of total predictions,*** results showed that the introduction of sunshine hours,precipitation and soil temperature data improved the prediction accuracy of individual cow milk prediction for the NARX model in the short,medium and long-term forecast *** hours was shown to have the largest impact on milk production with an improvement of forecast accuracy observed in 60%and 70%of all predictions(for all 39 test cows from both groups).However,the overall improvement in accuracy was small with a maximum forecast error reduction of 4.3%.Thus,the utilization of meteorological parameters in milk production forecasting did not have a substantial impact on forecast accuracy.

关键词： Milk production forecasting dairy modelling Model optimization Meteorological data

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