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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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Evaluating alternative stem cell hypotheses for adult corneal epithelial maintenance

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World Journal of Stem Cells 2015年第2期7卷 281-299页

作者： john d West Natalie J dorà J Martin Collinson Genes and development Group Centre for Integrative PhysiologyCollege of Medicine and Veterinary MedicineUniversity of Edinburgh Institute of Medical Sciences School of Medical SciencesCollege of Life Sciences and MedicineForesterhillUniversity of Aberdeen

In this review we evaluate evidence for three different hypotheses that explain how the corneal epithelium is maintained. The limbal epithelial stem cell(LESC)hypothesis is most widely accepted. This proposes that stem cells in the basal layer of the limbal epithelium, at the periphery of the cornea, maintain themselves and also produce transient(or transit) amplifying cells(TACs). TACs then move centripetally to the centre of the cornea in the basal layer of the corneal epithelium and also replenish cells in the overlying suprabasal layers. The LESCs maintain the corneal epithelium during normal homeostasis and become more active to repair significant wounds. Second, the corneal epithelial stem cell(CESC) hypothesis postulates that, during normal homeostasis, stem cells distributed throughout the basal corneal epithelium, maintain the tissue. According to this hypothesis, LESCs are present in the limbus but are only active during wound healing. We also consider a third possibility, that the corneal epithelium is maintained during normal homeostasis by proliferation of basal corneal epithelial cells without any input from stem cells. After reviewing the published evidence, we conclude that the LESC and CESC hypotheses are consistent with more of the evidence than the third hypothesis, so we do not consider this further. The LESC and CESC hypotheses each have difficulty accounting for one main type of evidence so we evaluate the two key lines of evidence that discriminate between them. Finally, we discuss how lineage-tracing experiments have begun to resolve the debate in favour of the LESC hypothesis. Nevertheless, it also seems likely that some basal corneal epithelial cells can act as long-term progenitors if limbal stem cell function is compromised. Thus, this aspect of the CESC hypothesis may have a lasting impact on our understanding of corneal epithelial maintenance, even if it is eventually shown that stem cells are restricted to the limbus as proposed by the

关键词： Eye Cornea Corneal epithelium Limbalepithelium Stem cell Lineage tracing

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differential response of tomato genotypes to Xanthomonas-specific pathogen-associated molecular patterns and correlation with bacterial spot (Xanthomonas perforans) resistance

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Horticulture Research 2016年第1期3卷 142-147页

作者： Krishna Bhattarai Frank J Louws john d Williamson dilip R Panthee department of Horticultural Science North Carolina State UniversityMountain Horticultural Crops Research and Extension CenterMills RiverMills RiverNC 28759USA department of Plant Pathology North Carolina State UniversityRaleighNC 27695USA department of Horticultural Science North Carolina State UniversityRaleighNC 27695USA

Plants depend on innate immune responses to retard the initial spread of pathogens entering through stomata,hydathodes or *** responses are triggered by conserved patterns in pathogen-encoded molecules known as pathogen-associated molecular patterns(PAMPs).Production of reactive oxygen species(ROS)is one of the first responses,and the resulting‘oxidative burst’is considered to be a first line of *** this study,we conducted association analyses between ROS production and bacterial spot(BS;Xanthomonas spp.)resistance in 63 genotypes of tomato(Solanum lycopersicum L.).A luminol-based assay was performed on leaf tissues that had been treated with a flagellin 22(flg22),flagellin 28 and a Xanthomonas-specific flg22(flg22-Xac)peptide,to measure PAMP-induced ROS production in each *** genotypes were also assessed for BS disease response by inoculation with Xanthomonas perforans,race *** there was no consistent relationship between peptides used and host response to the BS,there was a significant negative correlation(r=−0.25,Pdisease severity and ROS production,when flg22-Xac was *** response could potentially be used to identify the Xanthomonas-specific PRR allele in tomato,and eventually PAMP-triggered immunity loci could be mapped in a segregating *** has potential significance in tomato improvement.

关键词： eventually injuries specific

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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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Commission for the Management ＆ Application of Geoscience Information （CGI）

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Episodes 2006年第3期29卷 231-233页

作者： dr. Kristine Asch Ian jackson Bundesanstalt fiir Geowissenschafien und Rohstoffe （Federal Institute for Geosciences and Natural Resources） Stilleweg 2 d - 30655 Hannover Germany British Geological Survey Kingsley dunham Centre Keyworth Nottingham NG12 5GG UK

An introduction to CGI Information in general and digital information in particular, underpins all of the IUGS strategic objectives. CGI is helping to address a growing need to improve the quality and range of both information content and the applications that are used to acquire, analyse, process and disseminate geoscience data. It will do this by the exchange of knowledge and best practice and the support for standards. CGI is a new （strictly speaking, re-activated） Commission, founded by the lUGS in late 2002 following the demise of an earlier information Commission, COGEOINFO. Early tasks for CGI were to establish its objectives, set up its structure and modus operandi, elect its Council and establish a web presence. The new Commission was formally ratified by the IUGS at the IGC in Florence in 2004 and also held its first full Open Meeting there.

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Secondary Current and Classification of River Channels

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Applied Mathematics 2013年第1期4卷 70-78页

作者： Kaguchwa john Njenga Kwanza jackson Kioko Gathia Patricia Wanjiru Jomo Kenyatta University of Agriculture and Technology Nairobi Kenya Mathematics department Egerton University Egerton Kenya

In this research, the secondary current theory is used in investigating the role of phase shift angle between the secondary current and the channel axis displacement in stability analysis of a river channel. To achieve this, a small-perturbation stability analysis is developed for investigation of the role of the secondary current accompanying channel curvature in the initiation and early development of meanders in open channels. The secondary currents are generating in planes perpendicular to the primary direction of motion. The secondary currents form a helical motion in which the water in the upper part of the river is driven outward, whereas the water near the bottom is driven inward in a bend. Force-momentum equations for longitudinal and transverse direction in open channel bends were utilized. Assuming that the transverse force contributed by the bed is negligible, the pressure force associated with the transverse surface inclination is balanced by the centripetal force. Existing equations of the transverse velocity profile were analyzed. Since the magnitude of the vertical velocity is negligible compared to the transverse velocity in secondary currents, this study concentrates on the transverse velocity which is the radial component of the secondary current. This formulation leads to a linear differential equation which is solved for its orthogonal components which give the rates of meander growth and downstream migration. It is shown that instability increases with decrease in phase shift angle. Transition from straight to meandering and then from meandering to braiding occurs when phase shift angle is reduced.

关键词： Secondary Flow Phase Shift Meandering Braiding Stability

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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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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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