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Validation of.a Novel Method f.r Cardiac Output Estimation by CT Coronary Angiography

Advances in Computed Tomography 2012年第2期1卷 11-16页

作者： Hetal H. Mehta Brian G. Choi Reza Sanai Raman S. Dusaj Amr Mohsen Chunlei Liang jannet f. lewis Robert K. Zeman Department of.Mechanical and Aerospace Engineering The George Washington University Washington DC USA Department of.Medicine The George Washington University Washington DC USA Department of.Radiology The George Washington University Washington DC USA

Background: Cardiac output can be estimated during retrospectively gated CT coronary angiography by anatomically determining lef. ventricular volumes;prospective triggering to minimize radiation precludes this methodology. We propose an alternative method f.r cardiac output estimation based on preclinical models suggesting that cardiac output may be inversely related to contrast washout f.om the aortic root during timing bolus scanning, as measured by peak aortic root contrast attenuation. Methods: 34 patients had CT coronary angiography timing bolus perf.rmed with 20 ml iodixanol at 5.5 ml/s f.llowed by 20 ml normal saline at 5.5 ml/s through an 18-Ga antecubital catheter. Peak aortic root contrast attenuation was correlated to cardiac output calculated by echocardiography using heart rate stroke volume f.om biplane Simpson’s ***: Mean age was 58 ± 13 years;body surf.ce area, 2.0 ± 0.5 m2. 53% were women. Stroke volume, cardiac output and cardiac index were 67 ± 19 ml, 4.5 ± 1.6 L/min, and 2.2 ± 0.7 L/min/m2, respectively. Peak aortic root contrast attenuation was 207 ± 46 HU and correlated to cardiac output and cardiac index with r = –0.64, p Conclusion: This novel method f.r cardiac output estimation by CTCA appears f.asible. The CT physiologic parameters using the timing test-bolus data moderately correlated with echocardiographic assessment of.cardiac output. The calculation of.cardiac output adds important hemodynamic data to anatomic inf.rmation provided by CTCA, and f.rther development of.this method may preserve assessment of.lef. ventricular perf.rmance in prospective triggering.

关键词： Cardiac Output Coronary CT Angiography Hemodynamics Prospective Triggering Validation

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STUDIES ON SYNTHESIS, STRUCTURE AND REACTIVITY Of.ACTIVATED Os_6 RAf.-LIKE CLUSTERS

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Science China Chemistry 1990年第4期33卷 385-392页

作者：刘家础 B.f.G.JOHNSON J.lewis f.jian Institute of.Research on the Structure of.Matter Academia Sinica Fuzhou 350002PRC University Chemical Laboratory Lensfield Road Cambridge CB2 1EW U K

In this paper we report the synthesis and activation of.OS-6 raf.-llke planar clusters. The activated OS-66 raf.-like clusters [OS-66(CO)_(20)(MeCN)] and [OS-66(CO)_(19) (MeCN)_2] have been prepared by involving PdCl_2 as catalyst. Trimethylamine oxide (Me_3NO) has been used as an activation reagent to oxidize several carbonyl ligands coordinated in the activated clusters and to get a series of.activated OS-66 raf.-like clusters [OS-66(CO)_(21-x)(MeCN)_x] (n = 1--5) and corresponding substituted clusters [OS-66(CO)_(21-x)(P(OMe)_3)_x] (n=1--5). The structures of.these OS-66 raf.-like clusters have been characterized by the inf.ared spectra (IR), nuclear magnetic resonance spectra (NMR) and mass spectra (MS), and the characters of.the raf.-like planar structure and reactivity above have also been discussed in this paper.

关键词： Os raf.-like clusters coupling reaction aetivation.

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Is It Possible to Publish a Calibration f.nction f.r Radiochromic f.lm?

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International Journal of.Medical Physics, Clinical Engineering and Radiation Oncology 2014年第1期3卷 25-30页

作者： Maria f. Chan David lewis Xiang Yu Advanced Materials Group Ashland Inc. Bridgewater USA Department of.Medical Physics Memorial Sloan-Kettering Can-cer Center Basking Ridge USA

Purpose: To assess the possibility of.using a public calibration f.nction f.r radiochromic f.lm dosimetry in dose QA of.highly conf.rmal treatment plans. Methods: EBT3 f.lm calibration strips (3.5 × 20 cm2 f.om lots A101212 and A011713) were exposed on a Varian Trilogy at a f.cility to a 10 × 10 cm2 open f.eld at doses of.80, 160, 320 cGy using 6MV photons. Together with a strip of.unexposed f.lm f.om the same lot, the exposed f.lms were digitized in a single scan using dif.erent Epson 10,000 XL scanners at two dif.erent f.cilities. The dose-response data f.r each color-channel f.om each f.cility were generated using the same calibration f.nction X(D) = a + b/(D - c), where X(D) is the response at dose D and a, b and c are the coef.icients. Dif.erent batches of.EBT3 f.lm were exposed to a VMAT beam. These f.lms, plus two ref.rence strips exposed to doses of.zero and 160 cGy, were digitized on the scanners at the two f.cilities. Using the multi-channel dosimetry method and One-scan protocol (Med Phys, 39: 6339-6349, 2012) the recorded doses on the VMAT f.lms were calculated and the results were compared with the VMAT plan using a Gamma index of.3%/3 mm. Results: The passing rates obtained f.r dose maps calculated f.r all combinations of.VMAT images and calibration f.nctions were nearly unchanged, using the One-scan protocol. Also, in all cases a passing rate of.>99% was obtained f.r Gamma index of.3%/3 mm. On the other hand, if.the One-scan protocol was not employed, the dose maps f.r VMAT images and calibration f.nctions f.om dif.erent scanners showed poor correlation with the treatment plan. This is probably due to the scan-to-scan variability. Conclusions: The authors have f.und that it is f.asible to use a public calibration f.nction f.r a given radiochromic f.lm lot using the same methodology, One-scan protocol, f.r patient-specif.c QA.

关键词： Dosimetry Quality Assurance IMRT Radiochromic f.lm Multichannel

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Epidemiology of.Sexual dysf.nction in Asia compared to the rest of.the world

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Asian Journal of.Andrology 2011年第1期13卷 152-158页

作者： Ronald W lewis Section of.Urology Medical College of Georgia Augusta GA 30912 USA

There have been a limited number of.epidemiological studies published on sexual disorders in persons f.om Asia. This paper aims to assess the reports of.sexual dysf.nction epidemiological studies published in the English language that involved Asian countries. Key points are summarized in this paper f.om nine epidemiological papers on sexual dysf.nction f.om Asia that were published in the English language. Seven met the criteria f.r evidence-based studies reaching a Prins score of.at least 10 or more. Papers included in this report came f.om national and regional representative studies in peer review journals. These results f.r sexual dysf.nction in the nine papers are summarized f.r various sexual dysf.nctions in men and women in Asian countries. In three of.these, worldwide data were presented in the same paper allowing comparisons with Asian data on prevalence rates. Detailed descriptions f.om each of.these studies are presented in paragraph f.rm. More detailed data on erectile dysf.nction （ED） is presented in a tabular f.rm. Collectively, there seems to be a need f.r country- and population-specif.c f.rther descriptive and analytical epidemiological studies in all of.the sexual disorders f.om Asia. This critical review paper should help guide these studies f.r reachinj[ evidence-based literature standards.

关键词： descriptive epidemiology male and f.male dysf.nction male ED premature ejaculation

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A novel application of.f.uidization-Integrating three processes in reclaiming f.undry sand

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Particuology 2010年第6期8卷 595-598页

作者： Derek Geldart Jim lewis Powder Research Ltd Leeds University UK Coastal River Technologies PLLC USA

Immersion of.automotive parts in a f.uidized bed of.f.undry sand is used to both strip the castings f.ee f.om moulding sand and to heat-treat the castings at 500℃. The f.uid bed is heated by hot gases f.om a burner directed f.rst into a serpentine heat exchanger located near one side-wall of.the rectangular tank, and then into a distributor consisting of.horizontal sparger pipes having maintenance standpipes f.xed into their upper surf.ces.

关键词： Removal of.moulding sand Castings f.uidized beds Heat transf.r f.undries

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MIXED INTERIOR PENALTY DISCONTINUOUS GALERKIN METHODS f.R ONE-DIMENSIONAL f.LLY NONLINEAR SECOND ORDER ELLIPTIC AND PARABOLIC EQUATIONS

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Journal of.Computational Mathematics 2014年第2期32卷 107-135页

作者： Xiaobing f.ng Thomas lewis Department of.Mathematics The University of Tennessee Knoxville TN 37996 U.S.A. Department of.Mathematics and Statistics The University of North Carolina at Greensboro NC 27402 U.S.A.

This paper is concerned with developing accurate and ef.icient numerical methods f.r one-dimensional f.lly nonlinear second order elliptic and parabolic partial dif.erential equations （PDEs）. In the paper we present a general f.amework f.r constructing high order interior penalty discontinuous Galerkin （IP-DG） methods f.r approximating viscosity solutions of.these f.lly nonlinear PDEs. In order to capture discontinuities of.the second order derivative uxx of.the solution u, three independent f.nctions p1,p2 and p3 are introduced to represent numerical derivatives using various one-sided limits. The proposed DG f.ame- work, which is based on a nonstandard mixed f.rmulation of.the underlying PDE, embeds a nonlinear problem into a mostly linear system of.equations where the nonlinearity has been modif.ed to include multiple values of.the second order derivative uxz. The proposed f.amework extends a companion f.nite dif.erence f.amework developed by the authors in [9] and allows f.r the approximation of.f.lly nonlinear PDEs using high order polynomials and non-unif.rm meshes. In addition to the nonstandard mixed f.rmulation setting, another main idea is to replace the f.lly nonlinear dif.erential operator by a numerical operator which is consistent with the dif.erential operator and satisf.es certain monotonicity （called g-monotonicity） properties. To ensure such a g-monotonicity, the crux of.the construction is to introduce the numerical moment, which plays a critical role in the proposed DG f.ame- work. The g-monotonicity gives the DG methods the ability to select the mathematically ＂correct＂ solution （i.e., the viscosity solution） among all possible solutions. Moreover, the g-monotonicity allows f.r the possible development of.more ef.icient nonlinear solvers as the special nonlinearity of.the algebraic systems can be explored to decouple the equations. This paper also presents and analyzes numerical results f.r several numerical test problems which are used to guage

关键词： f.lly nonlinear PDEs Viscosity solutions Discontinuous Galerkin methods.

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Inf.uence of.chemical reaction on heat and mass transf.r of.non-Newtonian f.uid with yield stress by f.ee convection f.om vertical surf.ce in porous medium considering Soret ef.ect

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Applied Mathematics and Mechanics(English Edition) 2010年第6期31卷 675-684页

作者： f. S. IBRAHIM f. M. HADY S. M. ABDEL-GAIED M. R. EID Department of.Mathematics Faculty of Science Assiut University Department of.Science and Mathematics Faculty of Education Assiut University

The ef.ect of.chemical reaction on f.ee convection heat and mass transf.r f.r a non-Newtonian power law f.uid over a vertical f.at plate embedded in a f.uid-saturated porous medium has been studied in the presence of.the yield stress and the Soret ef.ect. The governing boundary layer equations and boundary conditions are cast into a dimen- sionless f.rm by similarity transf.rmations, and the resulting system of.equations is solved by a f.nite dif.erence method. The results are preSented and discussed f.r concentration prof.les, as well as the Nusselt number and the Sherwood number f.r various values of.the parameters, which govern the problem. The results obtained show that the f.ow f.eld is inf.uenced appreciably by the presence of.the chemical reaction parameter γ the order *** chemical reaction parameter m, the Soret number St, the buoyancy ratio N, the lewis number Le, and the dimensionless rheological parameter Ω.

关键词： non-Newtonian f.uid f.ee convection chemical reaction yield stress Soret ef.ect

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Erythroid Lineage Cells in the Liver:Novel Immune Regulators and Beyond

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Journal of.Clinical and Translational Hepatology 2020年第2期8卷 177-183页

作者： Li Yang Kyle lewis Division of.Gastroenterology Hepatology and NutritionCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA Division of.Gastroenterology Hepatology&Nutrition Developmental Biology Center for Stem Cell and Organoid MedicineCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA

The lineage of.the erythroid cell has been revisited in recent years. Instead of.being classif.ed as simply inert oxygen carriers, emerging evidence has shown that they are a tightly regulated in immune potent population with potential devel-opmental plasticity f.r lineage crossing. Erythroid cells have been reported to exert immune regulatory f.nction through secreted cytokines, or cell-cell contact, depending on the conditions of.the microenvironment and disease models. In this review, we explain the natural history of.erythroid cells in the liver through a developmental lens, as it of.ers perspec-tives into newly recognized roles of.this lineage in liver biology. Here, we review the known immune roles of.erythroid cells and discuss the mechanisms in the context of.disease models and stages. Then, we explore the capability of.erythroid lineage as a cell source f.r regenerative medicine. We propose that the versatile lineage of.erythroid cells provides an underappreciated and potentially promising area f.r basic and translational research in the f.eld of.liver disease.

关键词： Erythroblast Immune suppression Liver inf.ammation Hepatogenesis

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Could zinc dipicolinate be used to“smuggle”zinc into prostate cancer cells?

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Journal of.Cancer Metastasis and Treatment 2020年第1期6卷 209-213页

作者： Mark f.McCarty Simon Iloki Assanga Lidianys lewis Lujan Catalytic Longevity f.undation San DiegoCA 92109USA Department of.Research and Postgraduate in f.od University of SonoraHermosillo 83210Mexico

Although prostate epithelium concentrates zinc f.r the purpose of.promoting citrate secretion,it loses its capacity to import zinc while undergoing malignant *** exclusion of.zinc may be necessary f.r the viability of.prostate cancer,as measures which increase the intracellular zinc content of.prostate cancers lead to cell death,oxidative stress,and a marked reduction in ATP,suggestive of.mitochondrial *** anti-f.ngal drug clioquinol,which can act as a zinc ionophore,can markedly slow the growth of.human prostate cancer in nude mice,and has been proposed as a clinical therapy f.r prostate ***,clioquinol is currently only available as a topical agent,as it was linked to subacute myelo-optic neuropathy with oral use.A more practical option f.r promoting zinc transport may be of.ered by the nutraceutical zinc dipicolinate,a stable chelate in which f.ur coordination positions of.zinc are occupied by two molecules of.the tryptophan metabolite picolinic *** dipicolinate is a highly ef.ective supplemental source of.zinc that has been shown to be more potent than soluble zinc salts f.r alleviating the symptoms of.acrodermatitis enteropathica,a genetic zinc def.ciency disorder ref.ecting homozygous loss of.f.nctional ZIP4 zinc importers in *** suggests that the zinc dipicolinate complex is suf.iciently stable and lipophilic to transf.r zinc across cellular *** so,it may have potential f.r“smuggling”zinc into prostate cancer ***,cell culture and rodent studies to evaluate the impact of.zinc dipicolinate on human prostate cancer are warranted.

关键词： Prostate cancer zinc clioquinol picolinic acid ZIP4

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Adaptive dynamic programming f.r online solution of.a zero-sum dif.erential game

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控制理论与应用（英文版） 2011年第3期9卷 353-360页

作者： Draguna VRABIE f.ank lewis United Technologies Research Center East Hartford Automation and Robotics Research Institute University of Texas at Arlington

This paper will present an approximate/adaptive dynamic programming(ADP) algorithm,that uses the idea of.integral reinf.rcement learning(IRL),to determine online the Nash equilibrium solution f.r the two-player zerosum dif.erential game with linear dynamics and inf.nite horizon quadratic *** algorithm is built around an iterative method that has been developed in the control engineering community f.r solving the continuous-time game algebraic Riccati equation(CT-GARE),which underlies the game *** here show how the ADP techniques will enhance the capabilities of.the of.line method allowing an online solution without the requirement of.complete knowledge of.the system *** f.asibility of.the ADP scheme is demonstrated in simulation f.r a power system control *** adaptation goal is the best control policy that will f.ce in an optimal manner the highest load disturbance.

关键词： Approximate/Adaptive dynamic programming Game algebraic Riccati equation Zero-sum dif.erential game Nash equilibrium

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