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Photonics Research 2021年第6期9卷 1117-1123页

作者： fRANK MEHNKE CHRISTIAN KUHN MARTIN GUTTMANN LUCA SULMONI VERENA MONTAG JOHANNES GLAAB tim WERNICKE MICHAEL KNEISSL Institute of Solid State Physics Technische Universität Berlin10623 BerlinGermany ferdinand-Braun-Institut Leibniz-Institut für Höchstfrequenztechnik12489 BerlinGermany Current address:School of Electrical and Computer Engineering Georgia Institute of TechnologyAtlantaGeorgia 30332USA

We present the growth and electro-optical characteristics of highly transparent AlGaN-based tunnel heterojunction light-emitting diodes(LEDs)emitting at 232 nm entirely grown by metalorganic vapor phase epitaxy(MOVPE).A GaN:Si interlayer was embedded into a highly Mg-and Si-doped Al_(0.87)Ga_(0.13)N tunnel junction to enable polarization field enhanced *** LEDs exhibit an on-wafer integrated emission power of 77μWat 5 mA,which correlates to an external quantum efficiency(EQE)of 0.29%with 45μWemitted through the bottom sapphire substrate and 32μW emitted through the transparent top *** depositing a highly reflective aluminum reflector,a maximum emission power of 1.73 mW was achieved at 100 mA under pulsed mode operation with a maximum EQE of 0.35%as collected through the bottom substrate.

关键词： heterojunction MOVPE AlGaN

Prospective evaluation of ^(18)f-fDG positron emission tomography in the preoperative staging of patients with hepatic colorectal metastases

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Hepatobiliary Surgery and Nutrition 2022年第4期11卷 539-554页

作者： tim Akhurst Mithat Gönen Raymond E.Baser Lawrence H.Schwartz Scott Tuorto Lynn A.Brody Anne Covey Karen T.Brown Steven M.Larson Yuman fong Department of Radiology Memorial Sloan-Kettering Cancer CenterNew YorkNYUSA Peter MacCallum Cancer Centre VictoriaAustralia Department of Epidemiology and Biostatistics Memorial Sloan-Kettering Cancer CenterNew YorkNYUSA Department of Surgery Memorial Sloan-Kettering Cancer CenterNew YorkNYUSA

Background:Despite considerable advances in preoperative imaging,up to one-third of patients operatively explored for hepatic colorectal metastases are unexpectedly found to harbor unresectable intrahepatic or extrahepatic ***:The current study is a prospective,blinded study comparing utility of[18f]2-fluoro-2-deoxyglucose positron emission tomography(18f-fDG-PET)to computed tomography(CT)and CT arterial portography(CTAP)as preoperative ***:The 125 planned subjects were *** seen on fDG-PET alone changed therapy for 23 of 125 patients(18%).fDG-PET confirmed other radiologic findings in 16 cases(13%),for an overall influence on therapy in 39 cases(31%).fDG-PET was the most sensitive diagnostic imaging test for extrahepatic cancer;it was 80-90%sensitive for extrahepatic cancer and 70-90%*** the 28 cases of unresectable disease due to extrahepatic disease,fDG-PET findings solely changed therapies in 16 cases(57%)and influenced therapy in seven other cases(25%).Of the 21 unresectable cases due to extent of intrahepatic disease,fDG-PET did not solely change therapy in ***,fDG-PET had the lowest sensitivity for hepatic sites compared with CT or *** particular,small(for small tumors was 0.58 and for patients on chemotherapy it was 0.66,a modest improvement over no ***:fDG-PET is an important test for preoperative staging of patients with hepatic colorectal metastases,affecting treatment decisions in nearly one-third of *** high yield is due mainly to detection of extrahepatic *** is therefore recommended in patients with extrahepatic lesions suspected to be disseminated cancer or those with high risk for extrahepatic *** is not a good test for identification of small tumors in the liver.

关键词： Positron emission tomography(PET) computed tomography(CT) colorectal hepatic metastases surgery

SCHISTOX: An individual based model for the epidemiology and control of schistosomiasis

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Infectious Disease Modelling 2021年第1期6卷 438-447页

作者： Matthew Graham Diepreye Ayabina tim CD.Lucas Benjamin S.Collyer Graham f.Medley T.Deirdre Hollingsworth Jaspreet Toor Big Data Institute Li Ka Shing Centre for Health Information and DiscoveryUniversity of OxfordOxfordUnited Kingdom Centre for Mathematical Modelling of Infectious Disease London School of Hygiene and Tropical MedicineLondonUnited Kingdom Centre for Environment and Health Imperial College LondonLondonUnited Kingdom Department of Infectious Disease Epidemiology School of Public HealthFaculty of MedicineSt Mary’s CampusImperial College LondonUnited Kingdom MRC Centre for Global Infectious Disease Analysis the Abdul Latif Jameel Institute for Disease and Emergency Analytics(J-IDEA)School of Public HealthImperial College LondonLondonW21PGUnited Kingdom

A stochastic individual based model,SCHISTOX,has been developed for the study of schistosome transmission dynamics and the impact of control by mass drug *** novel aspects that can be investigated include individual level adherence and access to treatment,multiple communities,human sex population dynamics,and implementation of a potential *** of the model parameters have been estimated within previous studies and have been shown to vary between communities,such as the age-specific contact rates governing the age profiles of ***,uncertainty remains as there are wide ranges for certain parameter values and a few remain relatively *** analyse the model dynamics by parameterizing it with published parameter *** also discuss the development of SCHISTOX in the form of a publicly available open-source GitHub *** next key development stage involves validating the model by calibrating to epidemiological data.

关键词： Schistosomiasis Individual based model Mass drug administration

GekkofS—A Temporary Burst Buffer file System for HPC Applications

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Journal of Computer Science & Technology 2020年第1期35卷 72-91页

作者： Marc-AndréVef Nafiseh Moti tim Süβ Markus Tacke Tommaso Tocci Ramon Nou Alberto Miranda Toni Cortes AndréBrinkmann Zentrum für Datenverarbeitung Johannes Gutenberg University MainzMainz 55128Germany Barcelona Supercomputing Center Barcelona 08034Spain Computer Architecture Department Universitat Politècnica de CatalunyaBarcelona 08034Spain

Many scientific fields increasingly use high-performance computing(HPC)to process and analyze massive amounts of experimental data while storage systems in today's HPC environments have to cope with new access *** patterns include many metadata operations,small I/O requests,or randomized file I/O,while general-purpose parallel file systems have been optimized for sequential shared access to large *** buffer file systems create a separate file system that applications can use to store temporary *** aggregate node-local storage available within the compute nodes or use dedicated SSD clusters and offer a peak bandwidth higher than that of the backend parallel file system without interfering with ***,burst buffer file systems typically offer many features that a scientific application,running in isolation for a limited amount of time,does not *** present GekkofS,a temporary,highly-scalable file system which has been specifically optimized for the aforementioned use *** provides relaxed POSIX semantics which only offers features which are actually required by most(not all)*** is,therefore,able to provide scalable I/O performance and reaches millions of metadata operations already for a small number of nodes,significantly outperforming the capabilities of common parallel file systems.

关键词： distributed file system high-performance computing(HPC) burst buffer POSIX(portable operating system interface)

Background Soil Mercury: An Unrecognized Source of Blood Mercury in Infants?

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Open Journal of Soil Science 2013年第1期3卷 23-29页

作者： Pamela f. Heckel tim C. Keener Grace K. LeMasters College of Engineering and Applied Science University of Cin- cinnati Cincinnati USA. College of Medicine University of Cincinnati Cincinnati USA College of Medicine University of Cincinnati Cincinnati USA

Introduction: During the past four decades, mercury (Hg) research focused on fish consumption has explained less than 22% of Hg in human blood. One overlooked exposure pathway for infants and young children is the concentration of Hg in soils. Although 75% of the U.S. population lives in urban areas near industrial facilities, minimal data exist regarding the concentration and speciation of Hg in residential soils. Chronic exposure through ingestion of low concentrations of Hg in soils may explain a portion of the blood Hg levels noted in infants. Methods: Three relatively unexposed residential sites in a suburban community were selected. The primary route of contamination was atmospheric deposition. Soils were digested in a nitric acid-hydrofluoric acid solution and analyzed by cold vapor atomic absorption spectrophotometry. Measured concentrations of total Hg in local suburban soil samples were compared to levels measured in a national study of 27 remote and rural sites. The Al-Shahristani pharmacokinetic model, developed after the 1971 Iraqi Methyl Hg poisoning incident, was used to calculate the blood Hg concentration in a hypothetical year-old infant. Results: Soil samples contained Hg concentrations ranging from 0.01 to 0.24 ppmw. The distribution of Hg in the soil samples was non-linear and non-normal. The mean soil Hg concentrations at the three locations were 0.08, 0.05 and 0.08 ppm. Calculated blood Hg concentrations for a 10 kg, year-old infant due to ingestion of soil (200 mg/day) containing 0.2, 0.4 and 0.8 ppm Hg were 0.08, 0.17 and 0.26 μg/L, respectively. Conclusions: The pilot study data appear to support the hypothesis that chronic, low-level soil ingestion may be a significant source of Hg for infants. further study is warranted.

关键词： Mercury Blood Mercury Pharmacokinetics Air Toxics

Spin frustration and magnetic ordering in triangular lattice antiferromagnet Ca_3CoNb_2O_9

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Chinese Physics B 2015年第12期24卷 549-553页

作者：代佳周萍王朋帅庞斐 tim J.Munsie Graeme M.Luke 张金珊于伟强 Department of Physics Renmin University of China Department of Physics and Astronomy Mc Master University Canadian Institute for Advanced Research School of Energy Power and Mechanical Engineering North China Electric Power University

We synthesized a quasi-two-dimensional distorted triangular lattice antiferromagnet Ca3CoNb2O9, in which the effective spin of Co2＋is 1/2 at low temperatures, whose magnetic properties were studied by dc susceptibility and magnetization techniques. The x-ray diffraction confirms the quality of our powder samples. The large Weiss constant θCW --55 K and the low Neel temperature TN- 1.45 K give a frustration factor f =｜ θCW/TN｜≈ 38, suggesting that Ca3 Co Nb2O9resides in strong frustration regime. Slightly below TN, deviation between the susceptibility data under zero-field cooling（ZfC）and field cooling（fC） is observed. A new magnetic state with 1/3 of the saturate magnetization Ms is suggested in the magnetization curve at 0.46 K. Our study indicates that Ca3 Co Nb2O9is an interesting material to investigate magnetism in triangular lattice antiferromagnets with weak anisotropy.

关键词： Ca3CoNb2O9 triangular lattice frustration spin glass magnetization plateau

Reduced striatal volumes in Parkinson’s disease:a magnetic resonance imaging study

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Translational Neurodegeneration 2012年第1期1卷 132-139页

作者： Toni L Pitcher Tracy R Melzer Michael R MacAskill Charlotte f Graham Leslie Livingston Ross J Keenan Richard Watts John C Dalrymple-Alford tim J Anderson Department of Medicine University of OtagoChristchurchNew Zealand New Zealand Brain Research Institute 66 Stewart StChristchurch 8011New Zealand Department of Psychology University of CanterburyChristchurchNew Zealand College of Medicine University of VermontBurlingtonVTUSA Christchurch Radiology Group ChristchurchNew Zealand Department of Neurology Canterbury District Health BoardChristchurchNew Zealand

Background:The presence and extent of structural changes in the brain as a consequence of Parkinson’s disease(PD)is still poorly ***:High-resolution 3-tesla T1-weighted structural magnetic resonance images in sixty-five PD and 27 age-matched healthy control participants were ***,caudate,and intracranial volumes were manually traced in the axial plane of 3D reconstructed *** nuclei volumes were normalized to intracranial volume for statistical *** status was assessed using the Unified Parkinson’s Disease Rating Scale and Hoehn and Yahr *** status was assessed using global status tests and detailed neuropsychological ***:Both caudate and putamen volumes were smaller in PD brains compared to controls after adjusting for age and *** volumes were reduced by 11%(p=0.001)and putamen volumes by 8.1%(p=0.025).PD striatal volumes were not found to be significantly correlated with cognitive or motor ***:Small,but significant reductions in the volume of both the caudate and putamen occur in PD *** reductions are independent of the effects of age and gender,however the relation of these reductions to the functional loss of dopamine,which is characteristic of PD,remains unclear.

关键词： Magnetic resonance imaging Volumetry Caudate Putamen Parkinson’s disease

Interannual Variation of Multiple Tropical Cyclone Events in the Western North Pacific

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Advances in Atmospheric Sciences 2012年第6期29卷 1279-1291页

作者：高建芸李天明 fujian Climate Center China Meteorological Administration International Pacific Research Center and Department of Meteorology University of Hawaii

The interannual variability of occurrence of multiple tropical cyclone （MTC） events during June-October in the western North Pacific （WNP） was examined for the period 1979-2006. The number of the MTC events ranged from 2 to 9 per year, exhibiting a remarkable year-to-year variation. Seven active and seven inactive MTC years were identified. Compared to the inactive years, tropical cyclone genesis locations extended farther to the east and in the meridional direction during the active MTC years. A composite analysis shows that inactive MTC years were often associated with the E1 Nifio decaying phase, as warm SST anomalies in the equatorial eastern-central Pacific in the preceding winter transitioned into cold sea surface temperature （SST） anomalies in the concurrent summer. Associated with the SST evolution were suppressed low-level cyclonic vorticity and weakened convection in the WNP monsoon region. In addition to the mean flow difference~ significant differences between active and inactive MTC years were also found in the strength of the atmospheric intraseasonal oscillation （ISO）. Compared with inactive MTC years, ISO activity was much stronger along the equator and in the WNP region during active MTC years. Both westwardand northward-propagating ISO spectrums strengthened during active MTC years compared to inactive years. The combined mean state and ISO activity changes may set up a favorable environment for the generation of MTC events.

关键词： multiple tropical cyclone events interannual variation

Golimumab in real-world practice in patients with ulcerative colitis:Twelve-month results

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World Journal of Gastroenterology 2020年第21期26卷 2852-2863页

作者： Niels Teich Harald Grümmer Eric Jorgensen Thomas Liceni frank Holtkamp-Endemann tim fischer Susanne Hohenberger Internistische Gemeinschaftspraxis für Verdauungs-und Stoffwechselkrankheiten Leipzig und Schkeuditz Leipzig 04105Germany Praxis für Innere Medizin/Gastroenterologie Potsdam 14471Germany Magen-Darm-Zentrum Remscheid Remscheid 42859Germany MVZ für Gastroenterologie am Bayerischen Platz Berlin 10825Germany Gastroenterologische Gemeinschaftspraxis am Germania-Campus Münster 48159Germany Medical Affairs MSD Sharp and Dohme GmbHHaar 85540Germany

BACKGROUND The introduction of biologics has revolutionized the management of the chronic inflammatory bowel disease,ulcerative colitis(UC),with many patients experiencing significant improvements not only in their symptoms but in other outcomes relevant to individuals and society as a *** Germany,there are no prospective data>3 mo that assess the work productivity,daily activities and quality of life(QoL)of patients with moderate-to-severe UC treated with *** To assess change in work productivity,capacity for daily activities and QoL in UC patients treated with golimumab in *** The validated Work Productivity Activity Impairment(WPAI)Questionnaire was used to analyze the change in work productivity,the capacity for daily activities after three months(primary endpoint)and disease specific and health related QoL(HRQoL)up to 1 year(secondary endpoints).The changes in work productivity and activity impairment were evaluated every three months until month twelve compared to ***-specific and health-related QoL were assessed with the inflammatory bowel disease questionnaire and with the short-form 12 health survey questionnaire(Sf-12).RESULTS This prospective non-interventional study included 287 *** analysis population was comprised of 282 patients who had completed at least two *** baseline,61%of patients had moderate UC and 18%had severe ***,75%of patients worked full-time or part-time at baseline.A total of 212 patients who were employed at the start of the study(employed population)were evaluated for the primary *** significantly reduced all WPAI sub-scores compared to baseline after three,six,nine and twelve months after the start of treatment(Pfic QoL and HRQoL,as measured by the Sf-12 questionnaire,improved significantly with golimumab at all evaluation times(Pf moderate-to-severe UC with golimum

关键词： Ulcerative colitis Quality of life Work productivity Non-interventional study Golimumab Work Productivity Activity Impairment(WPAI)Questionnaire

Current-induced degradation and lifetime prediction of 310 nm ultraviolet light-emitting diodes

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Photonics Research 2019年第7期7卷 14-18页

作者： Jan Ruschel Johannes Glaab Batoul Beidoun Neysha Lobo Ploch Jens Rass tim Kolbe Arne Knauer Markus Weyers Sven Einfeldt Michael Kneissl ferdinand-Braun-Institut Leibniz-Institut fur HochstfrequenztechnikGustav-Kirchhoff-Str.412489 BerlinGermany Technische Universitat Berlin Institut fur FestkorperphysikHardenbergstr.36EW6-710623 BerlinGermany

The impact of operation current on the degradation behavior of 310 nm UV LEDs is investigated over 1000 h of stress. It ranges from 50 to 300 mA and corresponds to current densities from 34 to 201 A/cm^*** separate the impact of current from that of temperature, the junction temperature is kept constant by adjusting the heat sink temperature. Higher current was found to strongly accelerate the optical power reduction during operation. A mathematical model for lifetime prediction is *** indicates that lifetime is inversely proportional to the cube of the current density, suggesting the involvement of Auger recombinati on.

关键词： degradation light-emitting diodes lifetime