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Nano Research 2020年第1期13卷 145-150页

作者： Dogan Kaya richard J.Cobley richard e.palmer Department of electronics and Automation Vocational School of AdanaCukurova University01160CukurovaAdanaTurkey Nanoscale Physics Research Laboratory School of Physics and AstronomyUniversity of BirminghamEdgbastonBirminghamB152TTUK College of engineering Swansea UniversityBay CampusFabian WaySwanseaSA18ENUK

Understanding the atomistic formation of oxide layers on semiconductors is important for thin film fabrication,scaling down conventional devices and for the integration of emerging research ***,the initial oxidation of Si(111)is studied using the scanning tunneling *** to the complete saturation of the silicon surface with oxygen,we are able to probe the atomic nature of the oxide layer *** establish the threshold for local manipulation of inserted oxygen sites to be+3.8 *** by combining imaging with local atomic manipulation are we able to determine whether inserted oxygen exists beneath surface-bonded oxygen sites and differentiate between sites that have one and more than one oxygen atom inserted beneath the *** to the creation of the thin oxide film we observe a flip in the manipulation rates of inserted oxygen sites consistent with more oxygen inserting beneath the silicon surface.

关键词： scanning tunneling microscopy(STM) local manipulation Si(111) oxidation

Neuromorphic nanocluster networks:Critical role of the substrate in nano-link formation

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Nano Research 2023年第7期16卷 10500-10506页

作者： Wenkai Wu Alexey V.Verkhovtsev Theodoros Pavloudis Andrey V.Solov’yov richard e.palmer Nanomaterials Lab Faculty of Science and EngineeringSwansea UniversityBay CampusFabian WaySA18ENSwanseaUK MBN Research Center Altenhöferallee 360438 Frankfurt am MainGermany School of Physics Faculty of SciencesAristotle University of ThessalonikiGR-54124 ThessalonikiGreece

Atomic cluster-based networks represent a promising architecture for the realization of neuromorphic computing systems,which may overcome some of the limitations of the current computing *** formation and breakage of links between the clusters are of utmost importance for the functioning of these computing *** paper reports the results of molecular dynamics simulations of synapse(bridge)formation at elevated temperature and thermal breaking processes between 2.8 nmsized Au1415 clusters deposited on a carbon substrate,a model ***,we find that the bridge formation process is driven by the diffusion of gold atoms along the substrate,no matter how small the gap between the clusters *** complementary simulations of the bridge breaking process reveal the existence of a threshold bias voltage to activate bridge rupture via Joule *** results provide an atomistic-level understanding of the fundamental dynamical processes occurring in neuromorphic cluster arrays.

关键词： atomic-switch network nanoclusters nanoparticles(NPs) clusters on surfaces synapse neuromorphics molecular dynamics(MD)

Angular dependence of nanoparticle generation in the matrix assembly cluster source

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Nano Research 2019年第12期12卷 3069-3074页

作者： Maria Chiara Spadaro Junlei Zhao William D.Terry Jian Liu Feng Yin Flyura Djurabekova richard e.palmer College of engineering Swansea UniversityBay CampusFabian WaySwansea SAI 8ENUK Department of Physics and Helsinki Institute of Physics University of HelsinkiP.O.Box43f FIN-00014HelsinkiFinland Nanoscale Physics Research Laboratory School of Physics and AstronomyUniversity of BirminghamBirmingham B152TTUK National Center for electron Microscopy in Beijing Key Laboratory cf Advanced Materials(MOE)The State Key Laboratory of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua UniversityBeijing 100084China School of Physics and Information Technology Shaanxi Normal UniversityXian 710062China Catalan Institute of Nanoscience and Nanotechnology(ICN2) CSIC and BISTCampus UABBellaterra08193 BarcelonaCataloniaSpain

The matrix assembly cluster source(MACS)represents a bridge between conventional instruments for cluster beam deposition(CBD)and thelevel of industrial *** method is based on Ar^+ion sputtering of a pre-condensed Ar-M matrix(where M,is typically a metal such asAg).each Ar^+ion produces a collision cascade and thus the formation of metal clusters is in the matrix,which are then sputtered *** wepresent an experimental and computational investigation of the cluster emission process,specifically its dependence on the Ar^+ion angle of in cidence and the cluster emission *** find the in cide nee angle strongly in flue nces the emerging cluster flux,which is assigned to thespatial location of the deposited primary ion energy relative to the cluster into the *** also found an approximately constant anglebetween the incident ion beam and the peak in the emitted cluster distribution,with value between 99°and 109°.

关键词： cluster beam deposition scale-up nano particles silver ligand-free green synthesis

Nearest Neighbor Sampling of Point Sets Using Rays

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1131-1174页

作者： Liangchen Liu Louis Ly Colin B.Macdonald richard Tsai Department of Mathematics The University of Texas at Austin2515 SpeedwayAustinTX 78712USA Oden Institute for Computational engineering and Sciences The University of Texas at Austin201 E24th StAustinTX 78712USA Department of Mathematics University of British Columbia1984 Mathematics RdVancouverBCV6T1Z2Canada

We propose a new framework for the sampling,compression,and analysis of distributions of point sets and other geometric objects embedded in euclidean *** approach involves constructing a tensor called the RaySense sketch,which captures nearest neighbors from the underlying geometry of points along a set of *** explore various operations that can be performed on the RaySense sketch,leading to different properties and potential *** information about the data set can be extracted from the sketch,independent of the ray *** integrals on point sets can be efficiently computed using the *** also present several examples illustrating applications of the proposed strategy in practical scenarios.

关键词： Point clouds Sampling Classification Registration Deep learning Voronoi cell analysis

Carbon dioxide enrichment affected flower numbers transiently and increased successful post-pollination development stably but without altering final acorn production in mature pedunculate oak (Quercus robur L.)

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Journal of Forestry Research 2024年第4期35卷 1-12页

作者： Ryan McClory richard H.ellis Martin Lukac Jo Clark Carolina Mayoral Kris M.Hart Andrew R.G.Plackett A.Rob MacKenzie School of Agriculture Policy and DevelopmentUniversity of ReadingAgricultureEarley GateWhiteknights RoadPO Box 237Reading RG66EUUK Faculty of Forestry and Wood Sciences Czech University of Life Sciences PraguePrague 165000Czechia Future Trees Trust Harwell Innovation CentreBuilding 173Curie AvenueHarwellOxford OX110QGUK Birmingham Institute of Forest Research University of BirminghamEdgbastonBirmingham B152TTUK School of Biosciences University of BirminghamEdgbastonBirmingham B152TTUK School of Geography Earth and Environmental SciencesUniversity of BirminghamEdgbastonBirmingham B152TTUK

Acorn production in oak(Quercus spp.)shows considerable inter-annual variation,known as masting,which provides a natural defence against seed predators but a highly-variable supply of acorns for uses such as in commercial tree planting each *** emissions of greenhouse gases have been very widely reported to influence plant growth and seed or fruit size and quantity via the‘fertilisation effect’that leads to enhanced *** examine if acorn production in mature woodland communities will be affected by further increase in CO_(2),the contents of litter traps from a Free Air Carbon enrichment(FACe)experiment in deciduous woodland in central england were analysed for numbers of flowers and acorns of pedunculate oak(Quercus robur L.)at different stages of development and their predation levels under ambient and elevated CO_(2) ***-annual variation in acorn numbers was considerable and cyclical between 2015 and 2021,with the greatest numbers of mature acorns in 2015,2017 and 2020 but almost none in *** numbers of flowers,enlarged cups,immature acorns,empty acorn cups,and galls in the litter traps also varied amongst years;comparatively high numbers of enlarged cups were recorded in 2018,suggesting *** at this site is a fruit maturation masting species(i.e.,the extent of abortion of pollinated flowers during acorn development affects mature acorn numbers greatly).Raising the atmospheric CO_(2) concentration by 150μL L^(−1),from early 2017,increased the numbers of immature acorns,and all acorn evidence(empty cups+immature acorns+mature acorns)detected in the litter traps compared to ambient controls by 2021,but did not consistently affect the numbers of flowers,enlarged cups,empty cups,or mature *** number of flowers in the elevated CO_(2) plots’litter traps was greater in 2018 than 2017,one year after CO_(2) enrichment began,whereas numbers declined in ambient *** with CO_(2) also increased the number o

关键词： Quercus robur L. Acorns Masting Pedunculate oak Carbon dioxide

Wildfire severity alters soil microbial exoenzyme production and fungal abundances in the southern Appalachian Mountains

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Pedosphere 2024年第5期 865-878页

作者： Megan L.SCHILL richard BAIRD Shawn P.BROWN Allison M.VeACH Department of Integrative Biology University of Texas at San Antonio Biochemistry Molecular Biology Entomology and Plant Pathology Department Mississippi State University Department of Biological Sciences The University of Memphis

Climate change has increased drought frequency and duration that are exacerbated by increased temperatures globally. This effect has, and will continue,to increase fire occurrence across many regions of North America. In the southern Appalachian Mountains, wildfires with high burn severity occurred in 2016due to increased drought and human activity. To investigate the effects of burn severity on soil physicochemical properties, microbial extracellular enzyme production, and microbial abundances in a temperate region, surface soils (0–15 cm) were collected from two sites (the Great Smoky Mountains National Park in Tennessee and the Nantahala National Forest in North Carolina, USA) spanning lightly, moderately, and severely burned areas, accompanied by adjacent unburned locations that act as controls. The soil samples were collected at three time points between 2017 and 2019 (i.e., 0.5, 1, and 2.5 years post-fire)among burn severity plots. Total hydrolytic enzyme production varied over time, with severe burn plots having significantly lower enzyme production at 2.5years post-fire. Individual enzymes varied among burn severities and across time post-fire. Light burn plots showed greater carbon-specific (β-glucosidase and β-xylosidase) and phosphorus-specific (acid phosphatase) enzyme activities at 0.5 years post-fire, but this effect was transient. At 2.5 years post-fire, theβ-xylosidase and acid phosphatase activities were lower in severe or moderate burn plots relative to the controls. In contrast, the activity of nitrogen-specific enzyme leucyl aminopeptidase was the lowest in severe burn plots at 0.5 years post-fire, but was the lowest in light burn plots at 2.5 years post-fire. The fungi:bacteria ratio declined with burn severity, indicating that fungi are sensitive or less resilient to high burn severity during recovery. These results suggest that wildfires alter trajectories for soil microbial structure and function within a 2.5-year timeframe, which potentially

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Contribution of CT Scanning in the Investigation of Cranioencephalic Lesions in Bangui

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Open Journal of Radiology 2024年第3期14卷 156-165页

作者： Bangue Songrou Francky Kouandongui Timothée Mobima Borel Tambala Yannick Héritier Sombot-Soule Stéphane Kouzou Judith Guiaba Kette euloge Tapiade Bidan richard Bazogo National Center of Medical Imaging of Bangui Bangui Central African Republic Maman elisabeth DOMITIeN Hospital Bangui Central African Republic Community Hospital of Bangui Bangui Central African Republic

Introduction: Cranioencephalic exploration has always played a major role in CT scans. In the Central Africa Republic (CAR), the lack of cross-sectional imaging before the year 2020 meant that no study had focused on cranioencephalic lesions. The aim of this study was to contribute to improving the management of cranioencephalic pathologies in CAR. Patients and Method: The study took place at the Bangui National Medical Imaging Centre (CNIMB). It was a retrospective study over a two-year period (March 1, 2021 to February 30, 2023). All patients referred for cranioencephalic CT scans were included, regardless of age or sex. Results: 1745 CT scans were performed, 575 of which were cranioencephalic CT scans. The majority of patients were male (53%). Most lived in the capital Bangui (90.9%). Patients aged 61 and over were the most representative. The distribution of patients by requesting department showed that the reception and emergency department was one of the least requesting departments. The main abnormalities observed were strokes, 82.1% of which were ischaemic strokes and 17.9% haemorrhagic strokes. Strokes were followed by degenerative lesions. Post-traumatic injuries included haemorrhagic contusions (38.3%), subdural haematomas in 20.5% of cases, and extradural haematomas (9.3%). Craniofacial lesions (fractures) were observed in 45.8% of cases. Conclusion: Cranioencephalic scans accounted for 1/3 of CT examinations performed during the study period. It revealed pathologies that could not be detected by conventional means. All in all, CT scans contributed to the diagnosis of cerebral pathologies.

关键词： Cranioencephalic Scan National Medical Imaging Centre Bangui

Contribution of CT in the exploration of Non-Traumatic Pathologies of the Lumbar Spine in Adults in Bangui

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Open Journal of Radiology 2024年第3期14卷 125-134页

作者： Bangue Songrou Francky Kouandongui Timothée Mobima Yannick Héritier Sombot Borel Tambala Stéphane Kouzou Judith Guiaba Kette euloge Tapiade Bidan richard Bazogo National Center of Medical Imaging of Bangui Bangui Central Africa Republic Maman elisabeth DOMITIeN Hospital Bangui Central Africa Republic Community Hospital of Bangui Bangui Central Africa Republic

Background: In Central African Republic, a study carried out in 2019 highlighted the limits of conventional radiography in the diagnosis of non-traumatic lower back pain in adults. Objective: The objective of this study is to show the value of CT scanning in the exploration of non-traumatic pathologies of the lumbar spine in adults. Patients and Method: Retrospective and descriptive cross-sectional study covering the files of patients aged at least 18 years old, sent for lumbar scanning from March 1 to December 31, 2021 at the medical imaging center. Results: In total, 593 scan examinations were performed including 159 (26.8%) examinations of the lumbar spine. The average age of the patients was 49.84 years. The majority were male (66%). 127 (79.8%) were referred mainly to the neurology and rheumatology departments. Common low back pain (n = 97, 61%) was the main reason for requesting a CT scan. The lumbar scan was performed without contrast product in 88.7% of cases. In total, 148 (93.1%) examinations were pathological and dominated by overall disc overhang (62.2%) and somatic and interapophyseal osteoarthritis (16.9%). The other lesions were spondylodiscitis (7.4%), tumor-like lesions (3.4%) and narrow lumbar canal (1.4%).

关键词： CT Scanning Lumbar Bangui Adults

COVID-19 vaccination produces exercise-responsive SARS-CoV-2 specific T-cells regardless of infection history

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Journal of Sport and Health Science 2024年第1期13卷 99-107页

作者： Kyle A.Smith Tiffany M.Zúñiga Forrest L.Baker Helena Batatinha Charles R.Pedlar Shane C.Burgess Michael P.Gustafson emmanuel Katsanis richard J.Simpson School of Nutritional Sciences and Wellness The University of ArizonaTucsonAZ 85721USA Department of Pediatrics The University of ArizonaTucsonAZ 85724USA Faculty of Sport Allied Health and Performance ScienceSt.Mary's UniversityTwickenham TW14SXUK Institute of Sport exercise and Health University College LondonLondon WC1E 7HUUK Department of Animal and Comparative Biomedical Sciences The University of ArizonaTucsonAZ 85721USA The University of Arizona Cancer Center The University of ArizonaTucsonAZ 85719USA Laboratory Medicine and Pathology Mayo Clinic ArizonaPhoenixAZ 85054USA Department of Immunobiology The University of ArizonaTucsonAZ 85724USA Department of Medicine The University of ArizonaTucsonAZ 85724USA Department of Pathology The University of ArizonaTucsonAZ 85724USA

Background:The mobilization and redistribution of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)specific T-cells and neutralizing antibodies(nAbs)during exercise is purported to increase immune surveillance and protect against severe coronavirus disease 2019(COVID-19).We sought to determine if COVID-19 vaccination would elicit exercise-responsive SARS-CoV-2 T-cells and transiently alter nAb ***:eighteen healthy participants completed a 20-min bout of graded cycling exercise before and/or after receiving a COVID-19 *** major leukocyte subtypes were enumerated before,during,and after exercise by flow cytometry,and immune responses to SARS-CoV-2 were determined using whole blood peptide stimulation assays,T-cell receptor(TCR)-βsequencing,and SARS-CoV-2 nAb ***:COVID-19 vaccination had no effect on the mobilization or egress of major leukocyte subsets in response to intensity-controlled graded ***,non-infected participants had a significantly reduced mobilization of CD4+and CD8+naive T-cells,as well as CD4+central memory T-cells,after vaccination(synthetic immunity group);this was not seen after vaccination in those with prior SARS-CoV-2 infection(hybrid immunity group).Acute exercise after vaccination robustly mobilized SARS-CoV-2 specific T-cells to blood in an intensity-dependent *** groups mobilized T-cells that reacted to spike protein;however,only the hybrid immunity group mobilized T-cells that reacted to membrane and nucleocapsid *** increased significantly during exercise only in the hybrid immunity ***:These data indicate that acute exercise mobilizes SARS-CoV-2 specific T-cells that recognize spike protein and increases the redistribution of nAbs in individuals with hybrid immunity.

关键词： Anti-viral COVID-19 exercise immunology SARS-CoV-2 T-Cells Vaccine

Sinonasal Polyposis: About 60 Cases at Fann University Hospital Center, Senegal

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International Journal of Otolaryngology and Head & Neck Surgery 2024年第1期13卷 53-61页

作者： Mame Sanou Diouf Moustapha Ndiaye Ahmadou Dembele evelyne Siga Diom Ciré Ndiaye Amadou Thiam richard e. A. Deguenonvo Abdou Sy Malick Ndiaye Abdourahmane Tall Issa Cheikh Ndiaye Raymond Diouf HOGIP Hospital Center Dakar Senegal Fann University Hospital Center Dakar Senegal Ourossogui Hospital Center Matam Senegal La Paix Hospital Center Ziguinchor Senegal Children Hospital Center of Diamniadio Dakar Senegal

Introduction: Sinonasal polyposis (SNP) is a chronic inflammatory disease of the mucosa of the nasal cavities and facial sinuses. It is characterized by an oedematous, multifocal and bilateral degeneration of the nasosinus mucosa, which originates in the lateral masses of the ethmoid, where it causes the formation of smooth, gelatinous, translucent and pyriform polyp lesions. The objective of this study was to review epidemiological, clinical, paraclinical data and evaluate the results of endoscopic surgical treatment. Patients and Methods: This is a retrospective study on 60 patients followed at the eNT department of the Fann National University Hospital Center, from January 2010 to December 2015. All patients with sinonasal polyposis were included in the study. Results: The average age of our patients was 38 years and the sex ratio (M/F) was 0.8. In the patients’ histories, we found 18% asthma and 10% Widal’s disease. The average consultation time was 8.5 years. All patients had consulted for nasal obstruction;rhinorrhea was bilateral and found in 67.7% of cases, with olfactory disorders accounting for 50%. The CT scan performed in 58% of cases made it possible to specify the extent of the lesions;the involvement of the ethmoidal sinus was constant and extended to the other sinuses except in 2 cases. All patients had received medical treatment with local corticosteroids. endoscopic surgical treatment was initiated in 43% of cases after failure of corticosteroid-based medical treatment. The evolution under treatment marked by the reappearance of symptoms that increased each month. At one month postoperatively, all clinical symptomatology had improved with the exception of olfactory disorders, which persisted in 3 patients. At 12 months we noted 12 cases of reappearance of nasal obstruction. Conclusion: SNP is a disease of little known etiology. The diagnosis is almost always clinical. endoscopic surgery remains a recourse to medical treatment. For good local contro

关键词： Sinonasal Polyposis endonasal endoscopic Surgery CHNU Fann