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Arrhythmogenic mechanisms in ryanodine receptor channelopathies

Science China(Life Sciences) 2015年第1期58卷 54-58页

作者： ZHAO Yan-Ting VALDIVIA Carmen R. GURROLA Georgina B. hernndez jonathan j. VALDIVIA Héctor H. Center for Arrhythmia Research Department of Internal MedicineCardiovascular DivisionUniversity of Michigan

Ryanodine receptors(Ry Rs) are the calcium release channels of sarcoplasmic reticulum(SR) that provide the maj.rity of calcium ions(Ca2+) necessary to induce contraction of cardiac and skeletal muscle *** their intracellular environment,Ry R channels are regulated by a variety of cytosolic and luminal factors so that their output signal(Ca2+) induces finely-graded cell contraction without igniting cellular processes that may lead to aberrant electrical activity(ventricular arrhythmias) or cellular *** importance of Ry R dysfunction has been recently highlighted with the demonstration that point mutations in RYR2,the gene encoding for the cardiac isoform of the Ry R(Ry R2),are associated with catecholaminergic polymorphic ventricular tachycardia(CPVT),an arrhythmogenic syndrome characterized by the development of adrenergically-mediated ventricular tachycardia in individuals with an apparently normal *** we summarize the state of the field in regards to the main arrhythmogenic mechanisms triggered by Ry R2 channels harboring mutations linked to *** CPVT mutations characterized to date endow Ry R2 channels with a gain of function,resulting in hyperactive channels that release Ca2+ spontaneously,especially during *** spontaneous Ca2+ release is extruded by the electrogenic Na+/Ca2+ exchanger,which depolarizes the external membrane(delayed afterdepolarization or DAD) and may trigger untimely action ***,a rare set of CPVT mutations yield Ry R2 channels that are intrinsically hypo-active and hypo-responsive to stimuli,and it is unclear whether these channels release Ca2+ spontaneously during *** discuss novel cellular mechanisms that appear more suitable to explain ventricular arrhythmias due to Ry R2 loss-of-function mutations.

关键词： ryanodine receptors CPVT sarcoplasmic reticulum cardiac arrhythmias

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THEORETICAL ANALYSIS OF A HIGH-MACH-NUMBER DILUTE INELASTIC GAS IMPINGING ON A SURFACE

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Acta Mathematica Scientia 2010年第2期30卷 633-644页

作者： Yu Hui Deng jonathan j. Wylie Qiang Zhang Department of Mathematics City University of Hong Kong 83 Tat Chee Avenue Kowloon Tong Hong Kong China Center for applied Mathematics and Statistics New Jersey Institute of Technology Newark NJ 07102 U.S.A.

We consider a problem of a 2-dimensional high-Mach-number dilute inelastic gas originating from infinity impinging on an oblique surface of infinite length. By analyzing probabilities of particle-particle collisions, we derive an analytical formula for the mean force experienced by the surface when the system is dilute. We also derive conditions for the validity of our theory.

关键词： dilute inelastic gas high-Mach-number force

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The effect of bacterial challenge on ferritin regulation in the yellow fever mosquito, Aedes aegypti

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Insect Science 2013年第5期20卷 601-619页

作者： Dawn L. Geiser Guoli Zhou jonathan j. Mayo j.y j. Winzerling Department of Nutritional Sciences College of Agriculture and Life Sciences the University of Arizona Tucson Arizona 85721 USA

Secreted ferritin is the maj.r iron storage and transport protein in insects. Here, we characterize the message and protein expression profiles of yellow fever mosquito （Aedes aegypti） ferritin heavy chain homologue （HCH） and light chain homologue （LCH） subunits in response to iron and bacterial challenge. In vivo experiments demonstrated tissue-specific regulation of HCH and LCH expression over time post-blood meal （PBM）. Transcriptional regulation of HCH and LCH was treatment specific, with differences in regulation for na？ve versus mosquitoes challenged with heat-killed bacteria （HKB）. Translational regulation by iron regulatory protein （IRP） binding activity for the iron-responsive element （IRE） was tissue-specific and time-dependent PBM. However, mosquitoes challenged with HKB showed little change in IRP/IRE binding activity compared to na？ve animals. The changes in ferritin regulation and expression in vivo were confirmed with in vitro studies. We challenged mosquitoes with HKB followed by a blood meal to determine the effects on ferritin expression, and demonstrate a synergistic, time-dependent regulation of expression for HCH and LCH.

关键词： Aedes aegypti bacteria ferritin iron IRP mosquito

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Biomedical engineering and erectile restoration:design considerations for urologic prosthetics

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Asian j.urnal of Andrology 2020年第1期22卷 15-19页

作者： jonathan j.Lund Prosthetic Urology Research and Development Boston ScientificMinnetonkaMN 55343USA

For patients with moderate-to-severe erectile dysfunction,implantable penile prostheses continue to be a viable *** device developers apply design controls during the development cycle to ensure that a product performs as intended in the final use *** process relies heavily on the principles of systems engineering and documents every facet of performance,unmet need,and *** better understand design philosophy,it is important to frame benchmarked performance outcomes in the context of the ideal *** consideration of erectile anatomy and physiology,including flaccid state,transitional phases,and full tumescence,informs penile prosthesis design philosophy and provides the foundation for product advancement.

关键词： design controls engineering fluid dynamics inflatable penile prosthesis systems engineering

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Enhanced optical absorption in semiconductor nano- particles enabled by nearfield dielectric scattering

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Nano Research 2017年第4期10卷 1292-1301页

作者： Kowsalya D. Rasamani jonathan j. Foley IV Brittney Beidelman Yugang Sun Department of Chemistry Temple University 1901 North 13th Street Philadelphia Pennsylvania 19122 USA Department of Chemistry William Paterson University 300 Pompton Road Wayne New Jersey 07470 USA Department of Physics Bryn Mawr College 101 North Merion Avenue Bryn Mawr Pennsylvania 19010 USA

The optical absorption of semiconducting AgBr nanocubes is significantly increased by up to 5 times in the measured spectral range when they are bonded to the surface of dielectric SiO2 nanospheres through electrostatic interaction. The absorption enhancement factor depends on the wavelength and the size of the SiO2 nanoparticles （NPs）. Finite-difference time-domain calculations provide the nearfield intensity mapping of a heterostructure that is composed of a AgBr nanocube in close contact with a SiO2 nanosphere. The electric-field distributions indicate the field enhancement near the SiO2/AgBr interface due to light scattering and absorption enhancement in the AgBr nanocube, implying that the enhanced scattering nearfield increases the absorption cross section of the AgBr nanocube. The absorption cross-section spectra calculated using Mie theory agree with the experimental observations. This discovery sheds light on the utilization of dielectric spherical particles to increase the absorption in semiconductor NPs, thus improving the light-harvesting efficiency for solar-energy conversion.

关键词： enhanced scattering nearfield dielectric scattering absorption enhancement Mie theory

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Natural and anthropogenic sources of lead, zinc, and nickel in sediments of Lake Izabal, Guatemala

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j.urnal of Environmental Sciences 2020年第10期32卷 117-126页

作者： Elisandra hernandez jonathan Obrist-Farner Mark Brenner William F.Kenney j.son H.Curtis Edward Duarte Geosciences and Geological and Petroleum Engineering Department Missouri Uniuersity of Science and Technology.RollaMO 65409USA. Department of Geological Sciences University of FloridaGainesvilleFL 32611USA Land Use and Enuironmental Change Institute Uniuersity of FloridaGainesvilleFL 32611USA Escuela de Quimica Universidad de San Carlos de Guatemala01012Guatermala

Sediments in Lake Izabal,Guatemala,contain substantial lead (Pb),zinc (Zn),and nickel (Ni).The lack of historical data for heavy metal concentrations in the sediments makes it difficult to determine the sources or evaluate whether inputs of metals to the lake have changed through *** measured the relative abundances and concentrations of Pb,Zn,and Ni by X-Ray Fluorescence core scanning and by Inductively Coupled Plasma Optical Emission Spectrometry in three sediment cores to explore stratigraphic distributions of metals in the lake *** amounts of Pb and Zn in the core taken near the Polochic Delta suggest that galena and sphalerite mining increased Pb and Zn delivery to Lake Izabal between ~1945 and 1965 *** up-core Ni increase in the core taken near a different mine on the north shore of Lake Izabal suggests that recent nickel mining operations led to an increase in Ni concentrations in the local sediments,but amounts in the other cores indicate that Ni is not widely distributed throughout the *** cores from Lake Izabal are reliable recorders of heavy metal input to the lake,and were measured to establish background metal levels,which would otherwise be *** of Pb,Zn,and Ni in older,pre-20th-century Lake Izabal sediments reflect input from natural erosion of *** results provide previously unavailable estimates of background metal concentrations in Lake Izabal before the onset of *** results are necessary for future monitoring related to mining contamination of the lake ecosystem.

关键词： Lake Izabal Heavy metals Lead contamination Anthropogenic impacts Mining Guatemala

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Naringenin prevents experimental liver fibrosis by blocking TGFβ-Smad3 and j.K-Smad3 pathways

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World j.urnal of Gastroenterology 2017年第24期23卷 4354-4368页

作者： Erika hernández-Aquino Natanael Zarco Sael Casas-Graj.les Erika Ramos-Tovar Rosa E Flores-Beltrán jonathan Arauz Mineko Shibayama Liliana Favari Víctor Tsutsumi j.sé Segovia Pablo Muriel Laboratory of Experimental Hepatology Department of PharmacologyCinvestav-IPNApartado Postal 14-740Mexico City Department of Physiology Biophysics and NeurosciencesCinvestav-IPNApartado Postal 14-740Mexico City Department of Pharmacology School of MedicineAutonomous University of Baja CaliforniaMexicaliApartado Postal 21100 Department of Infectomics and Molecular Pathogenesis Cinvestav-IPNApartado Postal 14-740Mexico City

To study the molecular mechanisms involved in the hepatoprotective effects of naringenin (NAR) on carbon tetrachloride (CCl4)-induced liver fibrosis. METHODSThirty-two male Wistar rats (120-150 g) were randomly divided into four groups: (1) a control group (n = 8) that received 0.7% carboxy methyl-cellulose (NAR vehicle) 1 mL/daily p.o.; (2) a CCl4 group (n = 8) that received 400 mg of CCl4/kg body weight i.p. 3 times a week for 8 wk; (3) a CCl4 + NAR (n = 8) group that received 400 mg of CCl4/kg body weight i.p. 3 times a week for 8 wk and 100 mg of NAR/kg body weight daily for 8 wk p.o.; and (4) an NAR group (n = 8) that received 100 mg of NAR/kg body weight daily for 8 wk p.o. After the experimental period, animals were sacrificed under ketamine and xylazine anesthesia. Liver damage markers such as alanine aminotransferase (ALT), alkaline phosphatase (AP), γ-glutamyl transpeptidase (γ-GTP), reduced glutathione (GSH), glycogen content, lipid peroxidation (LPO) and collagen content were measured. The enzymatic activity of glutathione peroxidase (GPx) was assessed. Liver histopathology was performed utilizing Masson’s trichrome and hematoxylin-eosin stains. Zymography assays for MMP-9 and MMP-2 were carried out. Hepatic TGF-β, α-SMA, CTGF, Col-I, MMP-13, NF-κB, IL-1, IL-10, Smad7, Smad3, pSmad3 and pj.K proteins were detected via western blot. RESULTSNAR administration prevented increases in ALT, AP, γ-GTP, and GPx enzymatic activity; depletion of GSH and glycogen; and increases in LPO and collagen produced by chronic CCl4 intoxication (P 4. Although zymography assays showed that CCl4 produced an increase in MMP-9 and MMP-2 gelatinase activity; interestingly, NAR administration was associated with normal MMP-9 and MMP-2 activity (P < 0.05). The anti-inflammatory, antine

关键词： Fibrosis Transforming growth factor-β Naringenin pSmad3 Smad3 j.K Nuclear factor kappa Carbon tetrachloride

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Sexual dimorphism in cranial shape and size in geomyoid rodents:multivariate and evolutionary perspectives

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Current Zoology 2022年第4期68卷 469-487页

作者： jonathan j.M Calede Andrew Brown Department of Evolution Ecologyand Organismal BiologyThe Ohio State University318 W.12th Ave.300 Aronoff LaboratoryColumbusOH 43210USA The Ohio State University at Marion 1459 Mount Vernon AvenueMarionOH 43302USA College of Veterinary Medicine Texas A&M University660 Raymond Stotzer PkwyCollege StationTX 77843USA

Geomyoid rodents provide a great study system for the analysis of sexual *** are polygynic and many inhabit harsh arid environments thought to promote sexual *** fact,there has been extensive work published on the sexual size dimorphism of individual populations and species within this rodent ***,little work has been undertaken to assess the evolutionary patterns and processes associated with this sexual *** use multivariate analyses of cranial measurements in a phylogenetic framework to determine the distribution of size and shape dimorphism among geomyoids and test for Rensch’s *** results suggest that sexual dimorphism is more common in geomyids than heteromyids,but it is not in fact *** is evidence for variation in sexual dimorphism across ***,in many taxa,geographic variation appears to overwhelm existing sexual *** find support for the repeated independent evolution of shape and size dimorphism across geomyoid taxa,but we do not find support for an association between size and shape *** is no evidence for Rensch’s rule in geomyoids,whether at the superfamily or family ***,our findings suggest that there is no single explanation for the evolution of sexual dimorphism in geomyoids and that,instead,it is the product of numerous evolutionary *** studies incorporating phylogenetic relationships will be necessary to paint a more complete picture of the evolution of sexual dimorphism in geomyoids.

关键词： Geomyidae Heteromyidae phylogenetic comparative methods morphometrics Rensch’s rule

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Gulliver's travels

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作者： jonathan Swift edited by Albert j. Rivero.

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Multivariate analyses of skull morphology inform the taxonomy and evolution of geomyoid rodents

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Current Zoology 2023年第4期69卷 456-474页

作者： Lily A.Noftza jonathan j.M.Calede aBiology Program The Ohio State University at Marion1459 Mount Vernon AvenueMarionOH 43302USA Department of Evolution Ecologyand Organismal BiologyThe Ohio State University318 W.12th Ave.ColumbusOH 43210USA.

Morphological analyses are critical to quantify phenotypic variation,identify taxa,inform phylogenetic relationships,and shed light on evolutionary *** work is particularly important in groups that display great morphological *** is the case in geomyoid rodents,a group that includes 2 of the most species-rich families of rodents in North America:the Geomyidae(pocket gophers)and the Heteromyidae(kangaroo rats,pocket mice,and their relatives).We assessed variation in skull morphology(including both shape and size)among geomyoids to test the hypothesis that there are statistically significant differences in skull measurements at the family,genus,and species *** sample includes 886 specimens representing all geomyoid genera and 39 *** used the geometric mean to compare size across *** used 14 measurements of the cranium and lower j.w normalized for size to compare shape among and within *** results show that skull measurements enable the distinction of geomyoids at the family,genus,and species *** is a larger amount of size variation within Geomyidae than within *** phylomorphospace analysis shows that the skull shape of the common ancestor of all geomyoids was more similar to the common ancestor of heteromyids than that of *** skulls display negative allometry whereas heteromyid skulls display positive *** heteromyids,dipodomyines,and non-dipodomyines show significantly different allometric *** analyses including fossils will be necessary to test our evolutionary hypotheses.

关键词： canalization convergent evolution Geomyidae Heteromyidae morphometrics phylomorphospace

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