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Recent laser upgrades at Sandia's Z-backlighter facility in order to accommodate new requirements for magnetized liner inertial fusion on the Z-machine

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High Power Laser Science and Engineering 2016年第4期4卷 1-12页

作者： Jens Schwarz Patrick Rambo darrell armstrong Marius Schollmeier Ian Smith Jonathan Shores Matthias Geissel Mark Kimmel John Porter Sandia National Laboratories

The Z-backlighter laser facility primarily consists of two high energy, high-power laser systems. Z-Beamlet laser(ZBL)(Rambo et al., Appl. Opt. 44, 2421(2005)) is a multi-kJ-class, nanosecond laser operating at 1054 nm which is frequency doubled to 527 nm in order to provide x-ray backlighting of high energy density events on the Z-machine. Z-Petawatt(ZPW)(Schwarz et al., J. Phys.: Conf. Ser. 112, 032020(2008)) is a petawatt-class system operating at 1054 nm delivering up to 500 J in 500 fs for backlighting and various short-pulse laser experiments(see also Figure 10 for a facility overview). With the development of the magnetized liner inertial fusion(MagLIF) concept on the Z-machine, the primary backlighting missions of ZBL and ZPW have been adjusted accordingly. As a result, we have focused our recent efforts on increasing the output energy of ZBL from 2 to 4 kJ at 527 nm by modifying the fiber front end to now include extra bandwidth(for stimulated Brillouin scattering suppression). The MagLIF concept requires a well-defined/behaved beam for interaction with the pressurized fuel. Hence we have made great efforts to implement an adaptive optics system on ZBL and have explored the use of phase plates. We are also exploring concepts to use ZPW as a backlighter for ZBL driven MagLIF experiments. Alternatively, ZPW could be used as an additional fusion fuel pre-heater or as a temporally flexible high energy pre-pulse. All of these concepts require the ability to operate the ZPW in a nanosecond long-pulse mode, in which the beam can co-propagate with ZBL. Some of the proposed modifications are complete and most of them are well on their way.

关键词： adaptive optics high energy lasers MagLIF OPCPA petawatt lasers SBS suppression

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Integrating geographical information systems,remote sensing,and machine learning techniques to monitor urban expansion:an application to Luanda,Angola

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Geo-Spatial Information Science 2023年第3期26卷 446-464页

作者： armstrong Manuvakola Ezequias Ngolo Teiji Watanabe Graduate School of Environmental Science Hokkaido UniversitySapporoJapan Faculty of Environmental Earth Science Hokkaido UniversitySapporoJapan

According to many previous studies,application of remote sensing for the complex and heterogeneous urban environments in Sub-Saharan African countries is challenging due to the spectral confusion among features caused by diversity of construction *** to classification based on spectral indices that are expected to better highlight features of interest and to be prone to unsupervised classification,this study aims(1)to evaluate the effectiveness of index-based classification for Land Use Land Cover(LULC)using an unsupervised machine learning algorithm Product Quantized K-means(PQk-means);and(2)to monitor the urban expansion of Luanda,the capital city of Angola in a Logistic Regression Model(LRM).Comparison with state-of-the-art algorithms shows that unsupervised classification by means of spectral indices is effective for the study area and can be used for further *** built-up area of Luanda has increased from 94.5 km2 in 2000 to 198.3 km2 in 2008 and to 468.4 km2 in 2018,mainly driven by the proximity to the already established residential areas and to the main roads as confirmed by the logistic regression *** generated probability maps show high probability of urban growth in the areas where government had defined housing programs.

关键词： Land use land cover(LULC) spectral index remote sensing geographical information systems(GIS) machine learning PQk-means logistic regression

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Measurement and quantification of caking in excipients and food products with emphasis on the non-homogeneous interaction with ambient moisture

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Particuology 2021年第3期19卷 75-83页

作者： Katrina Brockbank Brian armstrong Jamie Clayton Freeman Technology Ltd 1 Miller CourtSevern DriveTewkesburyGloucestershireGL208DNUK

Whilst caking occurs via several different mechanisms,absorption and migration of moisture is frequently the most dominant mechanism within the food and pharmaceutical *** understanding the propensity to cake is important for minimising down-stream process issues,however most characterisation techniques assume that moisture induced caking occurs homogenously through the sample resulting in a uniformly caked powder *** this study,the effect of moisture induced caking on powder flowability was investigated using powder *** materials,including skimmed milk powder(SMP)and sulphated methyl ester(SME)were stored for several days under controlled humidity *** flow energies,a measure of the resistance to flow,were measured at 24 h intervals using an FT4 Powder *** the energy is measured as a function of the bed height,variations in the powder bed are also *** results demonstrated that caking does not always occur uniformly,instead a caked region(or crust)forms at the air-powder interface and then progresses through the powder ***,the strength of this caked region was shown to increase over several days before stabilising.

关键词： Powder Caking Crust formation Powder rheometry Relative humidity

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Detrital zircon U-Pb geochronology and geochemistry of the Riachuelos and Palma Sola beach sediments,Veracruz State,Gulf of Mexico:a new insight on palaeoenvironment

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Journal of Palaeogeography 2020年第4期9卷 495-521页

作者： John S.armstrong-Altrin Unidad de Procesos Oceánicos y Costeros Instituto de Ciencias del Mar y LimnologíaUniversidad Nacional Autónoma de MéxicoCiudad UniversitariaCiudad de México 04510México

Zircons are abundant in the beach *** this study,surface microtexture,mineralogy,bulk sediment geochemistry,trace element composition and U−Pb isotopic geochronology of detrital zircons collected from the Riachuelos and Palma Sola beach areas,southwestern Gulf of Mexico were performed to infer the sediment provenance and *** zircon microtexture was categorized as mechanically-and/or chemically-induced *** weathering index values for the Riachuelos(~72−77)and Palma Sola(~71−74)beach sediments indicated moderate weathering of both of the two source *** major and trace element data of bulk sediments suggested passive margin settings for the two *** trace elemental ratios and chondrite-normalized rare earth element(REE)patterns of bulk sediments revealed that the sediments were likely sourced by felsic and intermediate igneous *** the zircon Th/U ratios(mostly more than 0.2)and zircon REE patterns(with negative Eu and positive Ce anomalies)suggested a magmatic origin for both of the beach sediments from these two *** distinct zircon age peaks respectively belonging to the Paleozoic and the Cenozoic were identified both in the Riachuelos and Palma Sola beach *** geochronology comparison research between the Riachuelos−Palma Sola beach sediments and potential source areas in SW Gulf of Mexico revealed that the source terrane supplied the Paleozoic zircons of this study was identified as the Mesa Central Province(MCP),and the Cenozoic zircons were transported from the nearby Eastern Alkaline Province(EAP).Moreover,although the Precambrian zircons were very few in the studied sediments,their geochronology and geochemistry results still could infer that they were contributed by the source terranes of Grenvillian igneous suites in the Oaxaca and the Chiapas Massif Complexes.

关键词： Detrital zircon Beach sediment U-Pb dating Zircon grain morphology Microtexture Mineralogy Geochemistry Geochronology Gulf of Mexico

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Shared decision-making in stroke:an evolving approach to improved patient care

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Stroke & Vascular Neurology 2017年第2期2卷 84-87页

作者： Melissa J armstrong Department of Neurology University of Florida College of MedicineGainesvilleFloridaUSA

Shared decision-making(SDM)occurs when patients,families and clinicians consider patients’values and preferences alongside the best medical evidence and partner to make the best decision for a given patient in a specific *** is increasingly promoted within Western contexts and is also being explored outside such settings,including in *** and tools to promote SDM can improve patients’knowledge/understanding,participation in the decision-making process,satisfaction and trust in the healthcare *** has also proposed long-term benefits to patients,clinicians,organisations and healthcare *** successfully perform SDM,clinicians must know their patients’values and goals and the evidence underlying different diagnostic and treatment *** is relevant for decisions throughout stroke care,from thrombolysis to goals of care,diagnostic assessments,rehabilitation strategies,and secondary stroke *** physician,patient,family,cultural and system barriers to SDM *** to overcome these barriers and facilitate SDM include clinician motivation,patient participation,adequate time and tools to support the process,such as decision *** research about SDM in stroke care is lacking,decision aids are available for select decisions,such as anticoagulation for stroke prevention in atrial *** research is needed regarding both cultural aspects of successful SDM and application of SDM to stroke-specific contexts.

关键词： prevention overcome outside

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Congenital cytomegalovirus infection and advances in murine models of neuropathogenesis

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Virologica Sinica 2022年第2期37卷 318-320页

作者： Najealicka armstrong Qiyi Tang Department of Microbiology Howard University College of MedicineWashingtonDC20059USA

Congenital human cytomegalovirus(c HCMV) has been a well-known infectious cause of morbidity and mortality in newborns and a contributing factor for neurological disorders in infants(Crough and Khanna,2009).

关键词： Congenital mortality cytomegalovirus

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Biologics:how far can they go in Crohn’s disease?

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Gastroenterology Report 2022年第1期10卷 155-170页

作者： Katie A.Dunleavy darrell S.Pardi Division of Gastroenterology and Hepatology Mayo ClinicRochesterMNUSA

Crohn’s disease is a chronic gastrointestinal inflammatory disorder,characterized by episodes of relapsing and remitting *** the disease mechanism becomes better elucidated,there is a significant increase in the number of available biologic *** article summarizes and synthesizes current Food and Drug Administration-approved biological therapy for Crohn’s disease and examines the positioning of medical therapy as emerging biologics break onto the market.

关键词： Crohn’s disease medical treatment biologics anti-TNFs anti-integrins anti-interleukins JAK inhibitors S1Pinhibitors

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Assessing the Scale and Potential of Chinese Investment Overseas:An Econometric Approach

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China & World Economy 2011年第4期19卷 22-37页

作者： Shiro armstrong Crawford School of Economies and Government Australian National University

The recent rise in Chinese outward direct investment （ODI） has significant global implicatzons and impacts on host country policy. The present paper attempts to provide a theoretical basis and to define a robust econometric approach to assess the performance and potential of Chinese ODI. In this paper, foreign direct investment （FDI） performance is estimated using a frontier FDI model to measure how foreign investors, especially China, and the recipients of this direct investment perform relative to a benchmark of potential FDI. The results show that Chinese ODI achieves less of its potential compared with other investors. However, its ODI to Australia has performed much better than investment to other destinations. The results suggest that Chinese policy-makers should look at the pattern of China＇s ODI and, in light of superior performance in destinations like Australia, adjust policy strategies and institutional arrangements to enhance performance and reduce barriers to Chinese ODI.

关键词： Chinese investment foreign direct investment spatial linkage

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Primary epithelial tumours of the appendix in a black population:A review of cases

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World Journal of Gastroenterology 2009年第12期15卷 1472-1474页

作者： Rondell Patrell darrell Graham Nadia Patricia Williams Kamille Aisha West Department of Pathology University Hospital of the West Indies MonaKingston 7JamaicaWest Indies

AIM： To determine the and clinical features of prevalence, histologic types primary epithelial tumours of the vermiform appendix in a predominantly black population.METHODS： All cases of primary tumours of the appendix identified by review of the histopathology records at the University of the West Indies between January 1987 and June 2007 were selected. Relevant pathologic and clinical data were extracted with supplementation from patient charts where available. Non-epithelial tumours were excluded. The total number of appendectomy specimens over the period was also ascertained.RESULTS： Forty-two primary epithelial tumours were identified out of 6 824 appendectomies yielding a prevalence rate of approximately 0.62%. Welldifferentiated neuroendocrine cell tumours （carcinoids, 47.6%） and benign non-endocrine cell tumours （adenomas, 45.2%） were most common with nearly equal frequency. The median age was 43 years, with no sex predilection. Carcinoid tumours occurred in younger patients （mean age 32 years）, with a male-to-female ratio of 1.2：1. A clinical diagnosis of acute appendicitis was the most common reason for appendectomy （57.1%） and was histologically confirmed in 75% （18 of 24） of cases. In total, 16.7% of cases were diagnosed after incidental appendectomy.CONCLUSION： Appendiceal epithelial tumours are rare in our experience, and are represented principally by carcinoid turnours and adenornas. Carcinoid tumours occurred in younger patients but were slightly more common in men than women. Tumours were not suspected clinically and were diagnosed incidentally in specimens submitted for acute appendicitis supporting the need for histological evaluation in all resection specimens.

关键词： Epithelial tumours Appendiceal tumours Carcinoid Adenoma Appendicitis

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Iron and non-alcoholic fatty liver disease

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World Journal of Gastroenterology 2016年第36期22卷 8112-8122页

作者： Laurence J Britton V Nathan Subramaniam darrell HG Crawford Gallipoli Medical Research Institute The University of Queensland Greenslopes Private Hospital Brisbance Queensland 4120 Australia The Princess Alexandra Hospital Queensland 4120 Australia QIMR Berghofer Medical Research Institute Queensland 4120 Australia

The mechanisms that promote liver injury in non-alcoholic fatty liver disease(NAFLD) are yet to be thoroughly elucidated. As such, effective treatment strategies are lacking and novel therapeutic targets are required. Iron has been widely implicated in the pathogenesis of NAFLD and represents a potential target for treatment. Relationships between serum ferritin concentration and NAFLD are noted in a majority of studies, although serum ferritin is an imprecise measure of iron loading. Numerous mechanisms for a pathogenic role of hepatic iron in NAFLD have been demonstrated in animal and cell culture models. However, the human data linking hepatic iron to liver injury in NAFLD is less clear, with seemingly conflicting evidence, supporting either an effect of iron in hepatocytes or within reticulo-endothelial cells. Adipose tissue has emerged as a key site at which iron may have a pathogenic role in NAFLD. Evidence for this comes indirectly from studies that have evaluated the role of adipose tissue iron with respect to insulin resistance. Adding further complexity, multiple strands of evidence support an effect of NAFLD itself on iron metabolism. In this review, we summarise the human and basic science data that has evaluated the role of iron in NAFLD pathogenesis.

关键词： Iron Fatty liver Liver steatosis Insulin resistance Steatohepatitis Diabetes mellitus Adipose tissue

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