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Effect of viscosity on the avalanche dynamics and flow transition of wet granular matter

Particuology 2021年第6期19卷 64-75页

作者： jens h.kasper Vanessa Magnanimo Sjoerd D.M.de Jong Arjan Beek Ahmed Jarray Multi-Scale Mechanics(MSM) Thermal and Fluid EngineeringFaculty of Engineering Technology.University ofTwenteP.O.Box 2177500 AE EnschedeThe Netherlands Construction Management and Engineering(CME) Faculty of Engineering TechnologyUniversity ofTwenteP.O.Box 2177500 AE EnschedeThe Netherlands

The dynamic behaviour of granular flows is important in geo-mechanics and industrial applications,yet poorly *** studied the effects of liquid viscosity and particle size on the dynamics of wet granular material flowing in a slowly rotating drum,in order to detect the transition from the avalanching to the continuous flow regime.A discrete element method(DEM)model,in which contact forces and cohesive forces were considered,was employed to simulate this flow *** model was validated experimentally,using glass beads in a wooden drum and water–glycerol mixtures to tune the liquid *** DEM simulations showed comparable results to the experiments in terms of average slope angle and avalanche *** observed that the avalanche amplitude,flow layer velocity and granular temperature decrease as the liquid viscosity *** effect is more pronounced for smaller sized *** increase in viscous forces causes the flowing particles to behave as a bulk,pushing the free surface towards a convex *** addition,avalanches become less pronounced and the granular flow transitions from the avalanching regime to the continuous *** avalanching flow regime is marked by intermittent rigid body movement of the particulate bed and near-zero drops in the granular temperature,while no rigid body movement of the bed occurs in the continuous flow *** identified the avalanching-continuous flow transition region as a function of a dimensionless granular Galileo number.

关键词： Granular avalanche Transition Cohesion Viscosity Rotary drum DEM

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Suspect and non-targeted screening of chemical pollutants in Botswana's aquatic environments

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Emerging Contaminants 2024年第3期10卷 363-373页

作者： Kgato P.Selwe Charlotte R.head Gothatamang N.Phokedi jens E.T.Andersen J.Brett Sallach Caroline E.h.Dessent Department of Chemistry University of YorkHeslingtonYorkUnited Kingdom Department of Environment and Geography University of YorkHeslingtonYorkUnited Kingdom Department of Biology University of YorkHeslingtonYorkUnited Kingdom Department of Chemical and Forensic Sciences Botswana International University of Science and TechnologyBotswana

Chemical pollution in the aquatic systems of Botswana has been sparsely studied despite its potential ecological ***,we perform a study of water samples collected from 13 locations distributed across Botswana to obtain the first overview of the nature and distribution of chemical contaminants across the country's aquatic *** resolution mass spectrometry was applied using nontargeted and suspect screening methods to qualitatively analyse samples.A total of 114 contaminants of emerging concern(CECs)were identified including 68(59.6%)pharmaceuticals and pharmaceutical metabolites;16(14.2%)pesticides;13(11.4%)psychoactive compounds and metabolites;11(9.7%)industrial chemicals and intermediates and lastly,5(4.4%)personal care ***,3,4-dimethylmethcathinone,and diazolidinyl urea represented the most commonly detected pharmaceutical,psychoactive drug and personal care product,*** pesticide dodemorph and three industrial chemicals(stearamide,pthalic acid and bis(2-ethylhexyl)phthalate)were detected in all samples obtained.90 CECs were detected in receiving water(from 7 sample locations),75 in wastewater(from 3 sample locations)and 60 in surface water(from 9 sample locations).Of the compounds detected,only 8 had been identified in environmental samples acquired in Botswana *** discuss the variations in the nature and frequency of chemical pollutants detected in this work in a geographical *** results indicate that Botswana's aquatic systems are subject to pollution,despite wastewater treatment and that in order to mitigate potentially harmful effects on both human and aquatic ecosystems,more investigations are required to correctly identify,track and tackle the sources of pollution.

关键词： Emerging contaminants Chemical pollution Water analysis Pharmaceuticals LC-hRMS/MS

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Apoptosis within mouse eye induced by Toxoplasma gondii

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Chinese Medical Journal 2001年第6期114卷 80-84,109页

作者：胡世兴广州中山医科大学中山眼科中心广州510060

Objective　To investigate apoptosis induced by Toxoplasma gondii (T. gondii) in eyes of C57BL/6 (B6) mice. Methods　Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) technique and pathological changes within eyes were analyzed at different time points after intraocular inoculation of either 50 or 500 of tachyzoites. Results　In eyes that received 50 tachyzoites, a few apoptotic inflammatory cells in the anterior chamber and keratocytes in the cornea were seen at days 1 and 2, but no apoptosis was detected 4 days after inoculation. Significantly greater apoptosis of inflammatory cells was observed in the anterior chamber and in the vitreous of eyes injected with 500 parasites. Apoptosis of inflammatory cells in the anterior chamber and of keratocytes in the cornea was seen at day 1. The apoptotic stromal keratocytes strikingly increased at day 4. There were a number of apoptotic inflammatory cells in the vitreous at day 2, and a few apoptotic retinal cells along the internal limiting membrane and the nerve fiber layer of the retina 4 days after inoculation. Conclusion　These results suggest that apoptosis of inflammatory cells infiltrated eye infected with this parasite may be a mechanism of eliminating the organism.

关键词： mouse · ocular toxoplasmosis · inflammatory cells · apoptosis

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Quantifying and sorting of gold nanoparticle dimers from complex reaction mixtures using flow cytometry

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Nano Research 2016年第10期9卷 3093-3098页

作者： jens B. Simonsen Nini E. A. Reeler Anna Fossum Knud A. Lerstrup Bo W. Laursen kasper Nergaard Universitetsparken 5 Nano-Science Center & Department of Chemistry University of Copenhagen Copenhagen DK-2100 Denmark Niels jensens Vej 2 Sino-Danish Centre for Education and Research (SDC) Aarhus DK-8000 Denmark Ole Maaloes Vej 5 Biotech Research and Innovation Centre (BRIC) University of Copenhagen Copenhagen DK-2200 Denmark

The formation, characterization, and purification of well-defined stoichiometric clusters of metallic nanoparticles, particularly in the form of dimers or trimers, are important and formidable challenges in nanoscience. here we show that flow cytometry can be used as a high-throughput method to determine the relative distribution of oligomeric clusters of molecularly linked gold nano- particles in bulk solution at the single-particle level with good statistics. This unique information would be near impossible to obtain using traditional characterization techniques. The flow cytometric approach is utilized to provide fast feedback for the synthesis optimization of the complex reaction between citrate-stabilized gold nanoparticles and bi-functional molecular wires with dithiocarbamate anchoring groups. Finally, we demonstrate that flow cytometry can be used to significantly increase the proportion of AuNP dimers from an oligomer-rich polydisperse sample by size-selective sorting.

关键词： flow cytometry characterization sorting nanoparticles gold nanoparticle dimers

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Fully integrated and broadband Si-rich silicon nitride wavelength converter based on Bragg scattering intermodal four-wave mixing

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Photonics Research 2024年第3期12卷 I0001-I0010页

作者： VALERIO VITALI ThALÍA DOMÍNGUEZ BUCIO hAO LIU JOSÉMANUEL LUQUE GONZÁLEZ FRANCISCO JURADO-ROMERO ALEJANDRO ORTEGA-MOÑUX GLENN ChURChILL JAMES C.GATES JAMES hILLIER NIKOLAOS KALFAGIANNIS DANIELE MELATI jens h.SChMID ILARIA CRISTIANI PAVEL ChEBEN J.GONZALO WANGÜEMERT-PÉREZ ÑIGO MOLINA-FERNÁNDEZ FREDERIC GARDES COSIMO LACAVA PERIKLIS PETROPOULOS Optoelectronics Research Centre University of SouthamptonSouthampton SO171BJUK Electrical Computer and Biomedical Engineering DepartmentUniversity of PaviaPavia 27100Italy Telecommunication Research Institute(TELMA) Universidad de MálagaCEI Andalucı´a TECHE.T.S.I.Telecomunicación29010 MálagaSpain School of Science and Technology Nottingham Trent UniversityNottingham NG118NSUK Department of Electrical Engineering Eindhoven University of TechnologyEindhoven 5600 MBThe Netherlands Department of Materials Science and Engineering University of IoanninaIoannina 45110Greece Centre de Nanosciences et de Nanotechnologies UniversitéParis-SaclayCNRS91120 PalaiseauFrance Advanced Electronics and Photonics Research Center National Research Council CanadaOttawaOntario K1A 0R6Canada

Intermodal four-wave mixing(FWM)processes have recently attracted significant interest for all-optical signal processing applications thanks to the possibility to control the propagation properties of waves exciting distinct spatial modes of the same *** allows,in principle,to place signals in different spectral regions and satisfy the phase matching condition over considerably larger bandwidths compared to intramodal ***,the demonstrations reported so far have shown a limited bandwidth and suffered from the lack of on-chip components designed for broadband manipulation of different *** demonstrate here a silicon-rich silicon nitride wavelength converter based on Bragg scattering intermodal FWM,which integrates mode conversion,multiplexing and de-multiplexing functionalities *** system enables wavelength conversion between pump waves and a signal located in different telecommunication bands(separated by 60 nm)with a 3 dB bandwidth exceeding 70 nm,which represents,to our knowledge,the widest bandwidth ever achieved in an intermodal FWM-based system.

关键词： scattering pump modal

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Extrahepatic complications to cirrhosis and portal hypertension: haemodynamic and homeostatic aspects

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World Journal of Gastroenterology 2014年第42期20卷 15499-15517页

作者： S?ren M?ller jens h henriksen Flemming Bendtsen Department of Clinical Physiology and Nuclear Medicine Center for Functional and Diagnostic Imaging and Research Copenhagen University Hospital University of Copenhagen Gastro Unit Medical Division Hvidovre Hospital Hvidovre Hospital Faculty of Health Sciences University of Copenhagen

In addition to complications relating to the liver, patients with cirrhosis and portal hypertension develop extrahepatic functional disturbances of multiple organ systems. This can be considered a multiple organ failure that involves the heart, lungs, kidneys, the immune systems, and other organ systems. Progressive fibrosis of the liver and subsequent metabolic impairment leads to a systemic and splanchnic arteriolar vasodilatation. This affects both the haemodynamic and functional homeostasis of many organs and largely determines the course of the disease. With the progression of the disease, the circulation becomes hyperdynamic with cardiac, pulmonary as well as renal consequences for dysfunction and reduced survival. Infections and a changed cardiac function known as cirrhotic cardiomyopathy may be involved in further aggravation of other complications such as renal failure precipitatingthe hepatorenal *** with end-stage liver disease and related complications as for example the hepatopulmonary syndrome can only radically be treated by liver *** a bridge to this treatment,knowledge on the mechanisms of the pathophysiology of complications is essential for the choice of vasoactive drugs,antibiotics,drugs with specific effects on fibrogenesis and inflammation,and drugs that target specific receptors.

关键词： Fibrogenesis Splanchnic haemodynamics Inflammation Bacterial translocation Infections Systemic circulation Cirrhotic cardiomyopathy hepatopulmonary syndrome Portopulmonary hypertension hepatorenal syndrome Ascites

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hYDROCORTISONE POTENTIATES ThE INhIBITORY EFFECT OF INTERLEUKIN-1 ON PANCREATIC BETA-CELL FUNCTION IN VITRO

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中山大学学报(医学科学版) 1990年第1期 16-22页

作者：程桦,jens hφiriis Nielsen Department of Internal Medicine Sun Yat-Sen Memorial hospita hagedorn Research Laboratory Denmark

To test the possible influence of hydrocortisone on the inhibitory effect of interleukin-1 on the pancreatic beta-cell function, insulin release and insulin content of newborn rat islets incubated without or with interleukin-1 and/or hydroc-ortisone were measured. Interleukin-1 （500 ng/1） resulted in a decrease of insulin release during day 1～3, but a partial recovery from inhibition during days 4～7. The insulin content of the islets was not changed significantly. hydrocortisone had an inhibitory effect on insulin release (at 10-7M) or both insulin release and insulin content of islets (at 10-6M). Both 10-7and 10-6M hydrocortisone seem to prevent the initial decrease in insulin release exerted by interleukin-1 （500 ng/1） during day 1-3,but thereafter resulted in an even more marked decrease of insulin release correspon-ding to 51% (at 10-7M) or 25% (at 10-6M) of control islets, respectively, duringdays 4～7. Rebound of insulin release after interleukin-1 was not seen. Insulin c

关键词： Interleukin-1 hydrocortisone Pancreatic beta-cell function

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Non-breeding movements of the Black-tailed Gull(Larus crassirostris)

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Avian Research 2023年第2期14卷 206-214页

作者： huan Xia Cecilia Nilsson kasper Thorup Chenxi Jia Fumin Lei Key Laboratory of Zoological Systematics and Evolution Institute of ZoologyChinese Academy of SciencesBeijing100101China College of Life Science University of Chinese Academy of SciencesBeijing100049China Center for Macroecology Evolution and ClimateGlobe InstituteUniversity of CopenhagenDK-2100CopenhagenDenmark Center for Excellence in Animal Evolution and Genetics Chinese Academy of SciencesKunming650223China

With the continued development of tracking technology and increasing interest in animal movement,our understanding of migration behavior has become more ***,there are still many species that have not been well studied,particularly sea ***,we present the first year-round Global Positioning System(GPS)tracking data of the Black-tailed Gull(Larus crassirostris)at the population *** used solar-powered GPS-Global System for Mobile communication(GSM)loggers to successfully track 30 individuals breeding at Xingrentuo Islet,Liaoning Province,China,for 1-3 *** for one individual who roamed in the far north of the Yellow Sea during non-breeding period,all others did a directed southward *** routes and wintering sites differed among migrating gulls and between years for the birds tracked for two or more ***,during wintering,the migrating gulls were more likely to travel over a large body of water and shift sites,and some trajectories were quite complex,which was probably closely related to what we observed in the field about their boat-chasing *** to wintering movements,the post-breeding movements ranged over a smaller ***,almost all of them had a long post-breeding period near the breeding islet(≥120days,he breeding islet),and 80%of the gulls who were tracked more than one year had at least one faithful post-breeding *** to the post-breeding period,only approximately half of the migrating gulls had a pre-breeding period that was shorter(3-20 days)and closer to the breeding islet(≤80 km).Migration distance varied among migrating gulls(range 209-2405 km)and the gulls moved least distance during postbreeding ***,we found that the southward movement of the migrating gulls occurred when the temperature near the breeding islet dropped;specifically,the gulls directly migrated southward away from the post-breeding *** results suggest that the B

关键词： Black-tailed Gull GPS tracking Larus crassirostris Migration Post-breeding Pre-breeding Sea bird Wintering

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弓形虫温度敏感变异株疫苗和眼弓形虫病(英文)

弓形虫温度敏感变异株疫苗和眼弓形虫病(英文)

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全国寄生虫学与热带医学学术研讨会

作者：吕芳丽黄世光 Lloyd h.kasper 中山大学中山医学院寄生虫学教研室暨南大学医学院达特茅斯医学院医学和微生物学教研室

Ocular toxoplasmosis(OT),a potentially blinding disorder,is the most common cause of human retinochoroiditis *** this study,the role of CD8+,CD4,B cell,and IL-10 gene in the protective immunity of ocular vaccination with the temperature-sensitive mutant of Rh Toxoplasma gondii strain(ts-4) and challenge with Rh strain was investigated in murine models utilizing inbred C57BL/6 mice-deficient in CD4,CD8,B cells (μMT),or IL-10 ***-normal histology with few tachyzoites was observed in the eyes of wild-type(WT) mice immunized intraperitoneally with the avirulent ts-4 strain followed by intraocular challenge with the Rh strain of *** contrast,all mutant mice had partially decreased vaccine-induced resistance associated with increased ocular parasite burdens after Rh strain *** inflammation without evidence of necrosis associated with increased parasite burdens were observed in the eyes of CD4 knockout(KO) mice after ***8 KO andμMT mice,as well as IL-10 KO mice,demonstrated increased ocular necrosis in response to ocular *** parasite burden was significantly increased in the eyes of both CD8 KO andμMT mice.A significant increase of the percentages of B cells and CD8 T cells in the draining lymph nodes were observed in WT and IL-10 KO mice after *** expected,there were no increases in the levels of immunoglobulin G in serum or aqueous humor inμMT mice,and there was no increase in the levels of gamma interferon and tumor necrosis factor alpha in the sera of CD4 KO mice after *** results suggest that the attenuated ts-4 of *** inoculated intracamerally can induce ocular protective immunity;mice deficient in CD8,CD4 T cells or B cells exhibit increased ocular parasite burden after challenge;CD4,CD8,B cell, and IL-10 gene are all necessary to the vaccine-induced resistance to ocular challenge by virulent Rh strain.

关键词： Toxoplasma gondii Mice Eye Vaccine

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Model Experiments on Melting of Alloys with Low Melting Temperature in a Medium with high Melting Temperature

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Journal of Iron and Steel Research International 1999年第2期6卷 1-9页

作者： Becker jens-Ulrik Oeters Franz Thyssen-Krupp Stahl Gmbh Technical University Berlin

Experiments of alloy melting were carried out in water/hCl h 2O eutectic model system. The eutectic has a solid liquid equilibrium temperature of -74 ℃. 5 cm diameter spheres of the eutectic in which three thermocouples in the core, on the edge and in the middle between them had been positioned were cooled to -196 ℃ in liquid nitrogen. After cooling the spheres were immersed into water of 10 ℃, and the changes of temperatures with time in the three thermocouples were measured. In some experiments the temperature on the outer side of the spheres where an ice shell grew up was also measured. In these experiments, the growing rate of the shell was additionally determined. The results for the first minute of the melting process, where the system can be considered as one dimensional, were described by an exact solution of Fouriers equation. The density of liquid ferromanganese at 1 500 ℃ was measured.

关键词： alloy melting model experiment

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