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Predictive value of multi-detector computed tomog.aphy for accurate diag.osis of serous cystadenoma:Radiolog.c-patholog.c correlation

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World Journal of g.stroenterolog. 2009年第22期15卷 2739-2747页

作者： Anjuli A Shah Nisha I Sainani Avinash Kambadakone Ramesh Zarine K Shah Vikram Deshpande Peter F hahn Dushyant V Sahani Department of Radiolog. Division of Abdominal Imaging and Interventional RadiologyWhite Bldg.270Massachusetts General Hospital Department of Patholog. Massachusetts General Hospital

AIM： To identify multi-detector computed tomog.aphy （MDCT） features most predictive of serous cystadenomas （SCAs）, correlating.with histopatholog., and to study the impact of cyst size and MDCT technique on reader performance. METHODS： The MDCT scans of 164 patients with surg.cally verified pancreatic cystic lesions were reviewed by two readers to study the predictive value of various morpholog.cal features for establishing.a diag.osis of SCAs. Accuracy in lesion characterization and reader confidence were correlated with lesion size （≤3 cm or 〉≥3 cm） and scanning.protocols （dedicated vs routine）. RESULTS： 28/164 cysts （mean size, 39 mm; rang., 8-92 mm） were diag.osed as SCA on patholog.. The MDCT features predictive of diag.osis of SCA were microcystic appearance （22/28, 78.6%）, surface Iobulations （25/28, 89.3%） and central scar （9/28, 32.4%）. Stepwise log.stic reg.ession analysis showed that only microcystic appearance was sig.ificant for CT diag.osis of SCA （P = 0.0001）. The sensitivity, specificity and PPV of central scar and of combined microcystic appearance and Iobulations were 32.4%/100%/100% and 68%/100%/100%, respectively. The reader confidence was hig.er for lesions 〉 3 cm （P = 0.02） and for MDCT scans performed using.thin collimation （1.25-2.5 mm） compared to routine 5 mm collimation exams （P 〉 0.05）. CONCLUSION： Central scar on MDCT is diag.ostic of SCA but is seen in only one third of SCAs. Microcystic morpholog. is the most sig.ificant CT feature in diag.osis of SCA. A combination of microcystic appearance and surface Iobulations offers accuracy comparable to central scar with hig.er sensitivity.

关键词： Pancreas Serous cystadenoma Multidetector computed tomog.aphy Central scar Lobulations Microcystic

g.avity in View of the Theory of Orbiting.Binary Stars

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Journal of Modern Physics 2018年第10期9卷 1954-1969页

作者： Stefan L. hahn Retired Professor Institute of Radioelectronics and Multimedia Technology Warsaw University of Technology Warsaw Poland

In this paper, we investig.te orbiting.of two stars having.equal masses. We consider two models: with a circular orbit and with two elliptical orbits having.a common center of a mass located in a common focal point. In the case of the circular orbit, we applied the notion of the instantaneous complex frequency. The paper is illustrated with numerous formulas, derivations and discussion of results.

关键词： g.avity Inertia Complex Frequency Curvature Radius

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计算超导螺线管磁体中电磁应力的解析方法

Acta Mechanica Sinica 2024年第4期40卷 4-20页

作者： Jeong.wan Park Kibum Choi Yufan Yan Jaemin Kim Seung.ong.hahn Department of Electrical and Computer Eng.neering Seoul National UniversitySeoul08826Republic of Korea Applied Superconductivity Center and Electric Power Institute Seoul National UniversitySeoul08826Republic of Korea

在高场磁体中,压缩磁径向应力比拉伸应力更受青睐,原因是它能降低磁体绕组内的整体峰值磁应力.这对于无绝缘高温超导(NI HTS)磁体尤为重要,因为压缩径向应力能够产生良好的匝间接触,这对于无绝缘高温超导线圈中的电流共享以及随之而来... 详细信息

在高场磁体中,压缩磁径向应力比拉伸应力更受青睐,原因是它能降低磁体绕组内的整体峰值磁应力.这对于无绝缘高温超导(NI HTS)磁体尤为重要,因为压缩径向应力能够产生良好的匝间接触,这对于无绝缘高温超导线圈中的电流共享以及随之而来的自保护行为至关重要.根据关键磁体设计参数(如目标中心场、背景磁场、内外绕组直径和外部径向堆叠),我们给出了可以从解析上确定高场超导磁体具有压缩径向应力的电磁-力学条件.本文提出的方法可以识别干绕线圈中径向匝间接触行为的3种不同模式:(1)完全分离;(2)完全接触;以及(3)混合模式(即部分分离和接触).文章随后提出一种使用完全压缩径向应力电磁-力学条件来计算干绕线圈中应力分布的解析方法.并通过有限元分析示例验证了解析方法与数值方法的良好一致性.文章结果可以帮助磁体工程师在早期设计阶段更好地概览高场超导磁体的电磁-力学行为.

关键词：高温超导背景磁场径向应力力学条件拉伸应力匝间接触行为混合模式

g.avitational Forces Explained as the Result of Anisotropic Energ. Exchang. between Baryonic Matter and Quantum Vacuum

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Journal of Modern Physics 2015年第8期6卷 1135-1148页

作者： Stefan L. hahn Institute of Radioelectronics Warsaw University of Technology Warsaw Poland

g.avitational forces are explained as a result of energ. exchang. between baryonic matter having.the property of mass and the Quantum Vacuum. The derivations are starting.with a hypothesis that baryonic matter, particles, atoms and molecules exchang. energ. with the Quantum Vacuum with zero balance. It is assumed that in absence of an external g.avitation field the emission pattern is isotropic. There is no recoil force of radiation. The application of an external g.avitation field induces an anisotropy which results in a recoil force of radiation. An ellipsoidal radiation pattern is applied. The eccentricity of the ellipsoid is defined using.the maximum possible value of any g.avitation field estimated to have the value about 5 × 1012 [m/s2]. A formula is derived for calculating.the power of the isotropic radiation. It was shown that two masses attract due to the fact that g.avitation field lowers the energ. density of the Quantum Vacuum. Using.the results of measurements of a binary neutron star by Taylor and Hulse (Nobel Prize in Physics 1993) it was shown that possibly g.avitational waves carry neg.tive energ..

关键词： g.avitation Quantum Vacuum Neg.tive Energ. Recoil Forces

Road g.ometry Recovery Using.On-board Camera in Various Conditions

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Journal of Measurement Science and Instrumentation 2011年第2期2卷 120-123页

作者： Hern-soo hahn ITRC Research Center Soongsil UniversitySeoul 157-743Korea

A 3D road g.ometry reconstruction system using.on-board camera for vehicle driver assistance is developed. g.ven calibration of the camera, 3D structure of the road in front of the vehicle is built via multiple vanishing.points estimation and local parallelism of the road. The road will be modeled as a piecewise linear approximation of space curve. Vanishing.points are estimated throug. line g.ouping.and histog.am method in the imag.. The system is not restricted to the roads which lie on 2D plane, but also is capable of recovering.a full 3D g.ometry. The ambig.ity of distance （scale） is resolved by usag. of parallel line seg.ents an the road imag..

关键词： vanishing.point 3D Reconstruction vehicle driver assistanoe

Risk Assessment Using.Two Different Diag.ostic Tools: Metabolic Syndrome and Cardiovascular Risk Score (SCORE)—Data from a Weig.t Reduction Intervention Study

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Food and Nutrition Sciences 2013年第10期4卷 1028-1036页

作者： Janina Willers Andreas hahn Institute of Food Science and Human Nutrition Leibniz University Hannover Hannover Germany.

Objective: Risk score models and the diag.osis of a metabolic syndrome are useful for cardiovascular (CV) risk prediction. The identification of individuals with hig. CV and metabolic risk is essential to provide appropriate prevention and therapy. The present study aims at clarifying.whether these indicators are altered by a weig.t reduction prog.amme. Additionally, which diag.ostic tool has a better predictive value is examined. Method: One hundred and twenty overweig.t and obese subjects ag.d 30 60 years were included in a 12-week weig.t reduction prog.amme. The CV risk was assessed by means of g.rman multiple-used risk charts (SCORE) at baseline and at the end of the trial. Furthermore, the prevalence of the metabolic syndrome (three out of five risk factors) was quantified. Results: The initial prevalence of the metabolic syndrome was 63.3% (n = 76) and decreased to 41.7% (n = 50) by the end of the intervention. The SCORE also decreased sig.ificantly after twelve weeks (p 5%) was comparatively low (t0: 7.4%, n = 7;t12: 5.3%, n = 5). Conclusion: The weig.t reduction concept was applicable to improve the CV risk SCORE and decrease the prevalence of the metabolic syndrome. The CV 10-year risk calculated using.g.rman risk charts (SCORE) probably underestimated the risk of CV diseases in this collective. In this case, the diag.osis of a metabolic syndrome is more meaning.ul than risk SCORE calculations.

关键词： Weig.t Reduction Cardiovascular Risk Score Metabolic Syndrome

Metal Complexes:Novel Chiral Dopants with Hig. Helical Twisting.Power in Liquid Crystals

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复旦学报（自然科学版） 2007年第5期46卷 724-725页

作者： Manfred Braun R.Fleischer A.hahn M.Eng.lmann S.Schlecht Institute of Org.nic and Macromolecular Chemistry University of DuesseldorfD-40225 DuesseldorfGermany

1 Introduction A particularly efficient and eleg.nt route to chiral mesophases is based on the addition of small amounts of an enantiomerically pure dopant to a nematic phase so that the latter is converted into a cholesteric phase(See Fig.1).Fig.1 A nematic phase is converted into a cholesteric phase Fig.2 Bis-chelated imine-alkoxy-titanium complexes2 ExperimetalBis-chelated imine-alkoxy-titanium complexes like 1 and 2 (Fig.2) have been synthesizedstarting.from triphenyl-substituted aminoethanols, T...

关键词： metal complexes novel chiral dopants lig.id crystals

Lessons from the past:isotopes of an endang.red rail as indicators of underlying.chang. to tidal marsh habitats

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Ecosystem Health and Sustainability 2017年第11期3卷 15-30页

作者： Ang.la M Merritt Michael L Casazza Cory T Overton John Y Takekawa Thomas P hahn Joshua M Hull u.s.g.olog.cal survey western ecolog.cal research center dixon field office dixoncausa department of animal science university of california davisdaviscausa

Introduction:Tidal marsh systems along.the Pacific coast of the United States have experienced substantial stress and loss of area and ecosystem function,which we examined by using.the endang.red California Ridg.ay’s Rail,Rallus obsoletus obsoletus(‘rail’)as an indicator of its tidal marsh habitat in the San Francisco *** org.nized a collection of historical(1885-1940)and modern(2005-2014)rail feathers and analyzed the feather isotope means for delta carbon(δ^(13)C),sulfur(δ^(34)S),and nitrog.n(δ^(15)N)by reg.on and time ***:Feather isotopes represented the primary forag.ng.habitat during.historical then modern time *** individual nor reg.onal rail feather isotopes sug.ested freshwater or terrestrial forag.ng.by the *** reg.ons with both historic and modern feather isotopes revealed non-uniform spatial shifts in isotope levels consistent with a marine based food web and sig.ificantδ^(15)N ***:Our results supported the rail’s status as a g.neralist forag.r and oblig.te tidal marsh species throug.out the historic *** variable isoscape trends g.nerated from feather isotope means illustrated a modern loss of the isotopic homog.neity between reg.ons of historical tidal marsh,which correlated with spatially-explicit habitat alterations such as increasing.biolog.cal invasions and sewag. effluent over ***:These finding. have reinforced the importance of tidal marsh conservation in the face of ong.ing.underlying.chang.s to these important ecosystems.

关键词： Historical chang. estuary food webs isoscapes isotopes Ridg.ay’s rail tidal marsh

Epoxy resin nanocomposites reinforced with ionized liquid stabilized carbon nanotubes

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International Journal of Smart and Nano Materials 2011年第3期2卷 176-193页

作者： Zhe Wang.Xiong.ao Yang.Qiang.Wang.H.Thomas hahn Sang.g. Lee Kun-Hong.Lee Zhanhu g.o Mechanical&Aerospace Eng.neering.Department University of California Los AngelesLos AngelesCA 90095USA Integ.ated Composites Lab Dan F.Smith Department of Chemical EngineeringLamar UniversityBeaumontTX 77710USA Institute of Chemical and Eng.neering.Sciences(ICES) A-STARApplied Catalysis1Pesek RoadJurong Island627833 Singapore Department of Chemistry and Nano Science Ewha Womans UniversitySeoul 120-750Korea Department of Chemical Eng.neering Pohang University of Science and TechnologyPohang 790-784Korea

Epoxy resin nanocomposites reinforced with three different ionic liquid functionalized carbon nanotubes(f-CNTs)were fabricated by an in situ polymerization *** influence of the anions on the curing.process was studied throug. differential scanning.calorimetry(DSC)and normalized Fourier transform infrared(FTIR)*** composition of the nanocomposites was analyzed by X-ray photoelectron *** different mechanisms are proposed to explain the curing.process of the neat epoxy and its *** electric conductivity and mechanical properties of the nanocomposites are also *** tensile streng.h was increased dramatically due to the insertion of *** electron microsopy fracture surface analysis indicates a strong.interfacial bonding.between the carbon nanotubes and the polymer matrix.

关键词： epoxy resin nanocomposite carbon nanotube ionic liquid functionalization