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Machine learning in orthopaedic surgery

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World Journal of Orthopedics 2021年第9期12卷 685-699页

作者： simon p Lalehzarian Anirudh K Gowd Joseph N Liu The Chicago Medical School Rosalind Franklin University of Medicine and ScienceNorth ChicagoIL 60064United States Department of Orthopaedic Surgery Wake Forest Baptist Medical CenterWinston-SalemNC 27157United States USC Epstein Family Center for Sports Medicine Keck Medicine of USCLos AngelesCA 90033United States

Artificial intelligence and machine learning in orthopaedic surgery has gained mass interest over the last decade or *** prior studies,researchers have demonstrated that machine learning in orthopaedics can be used for different applications such as fracture detection,bone tumor diagnosis,detecting hip implant mechanical loosening,and grading *** time goes on,the utility of artificial intelligence and machine learning algorithms,such as deep learning,continues to grow and expand in orthopaedic *** purpose of this review is to provide an understanding of the concepts of machine learning and a background of current and future orthopaedic applications of machine learning in risk assessment,outcomes assessment,imaging,and basic science *** most cases,machine learning has proven to be just as effective,if not more effective,than prior methods such as logistic regression in assessment and *** the help of deep learning algorithms,such as artificial neural networks and convolutional neural networks,artificial intelligence in orthopaedics has been able to improve diagnostic accuracy and speed,flag the most critical and urgent patients for immediate attention,reduce the amount of human error,reduce the strain on medical professionals,and improve *** machine learning has shown diagnostic and prognostic uses in orthopaedic surgery,physicians should continue to research these techniques and be trained to use these methods effectively in order to improve orthopaedic treatment.

关键词： Artificial intelligence Machine learning Supervised learning Unsupervised learning Deep learning Orthopaedic surgery

Microstructure and mechanical properties of AZ91 magnesium alloy subject to deep cryogenic treatments

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International Journal of Minerals,Metallurgy and Materials 2013年第9期20卷 896-901页

作者： Gui-rong Li Hong-ming Wang Yun Cai Yu-tao Zhao Jun-jie Wang simon p.A. Gill School of Materials Science & Engineering Jiangsu University The State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of Sciences Department of Engineering University of Leicester

AZ91 magnesium alloy was subjected to a deep cryogenic treatment. X-ray diffraction （XRD）, scanning electronic microscopy （SEM）, and transmission electronic microscopy （TEM） methods were utilized to characterize the composition and microstructure of the treated samples. The results show that after two cryogenic treatments, the quantity of the precipitate hardening β phase increases, and the sizes of the precipitates are refined from 8-10μm to 2-4μm. This is expected to be due to the decreased solubility of aluminum in the matrix at low temperature and the significant plastic deformation owing to internal differences in thermal contraction between phases and grains. The polycrystalline matrix is also noticeably refined, with the sizes of the subsequent nanocrystalline grains in the range of 50-100 nm. High density dislocations are observed to pile up at the grain boundaries, inducing the dynamic recrystallization of the microstructure, leading to the generation of a nanocrystalline grain structure. After two deep cryogenic treatments, the tensile strength and elongation are found to be substantially increased, rising from 243 Mpa and 4.4% of as-cast state to 299 Mpa and 5.1%.

关键词： magnesium alloys cryogenic treatment microstructure mechanical properties

Corrosion Behavior of AZ31 Magnesium Alloy in Highly Alkaline Environment

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Acta Metallurgica Sinica(English Letters) 2017年第4期30卷 367-375页

作者： Somi Doja Lukas Bichler simon Fan School of Engineering University of British ColumbiaOkanagan 3333 University Way Kelowna BC V1V 1VTCanada ZincNyx Energy Solutions Vancouver BC V6P 6T3 Canada

Industrial components made with a magnesium-aluminum alloy AZ31 are often used in diverse engineering applications where component weight, strength, and durability are critical. Similarly as other Mg alloys, however, the AZ31 is susceptible to corrosion in alkaline environments. In this work, corrosion of commercial grade AZ31 alloy plate was examined in potassium hydroxide （KOH） using immersion and potentiodynamic studies. The results suggest that the concentration of A1 and Mn in the alloy may govern the kinetics of micro-galvanic corrosion and the initiation of corrosion pits. Further, trace amounts of Ni in the AZ31 alloy were seen to enable formation of Ni（OH）2 surface layer, which may have further accelerated alloy corrosion due to its cracking and void coalescence. The effect of pH on the corrosion behavior of AZ31 was studied with reference to pourbaix diagrams.

关键词： Magnesium alloy AZ31 KOH

Degradation and fate of 2,4-dinitroanisole(DNAN)and its intermediates treated with Mg/Cu bimetal:Surface examination with XAS,DFT,and LDI-MS

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Journal of Environmental Sciences 2023年第7期129卷 161-173页

作者： Andrew Mai Emese Hadnagy Qiantao Shi Lotanna Ezeonu Jason p.Robbins simon G.podkolzin Agamemnon Koutsospyros Christos Christodoulatos Center for Environmental Systems Stevens Institute of TechnologyHobokenNJ 07030USA School of Engineering and Technology University of Washington TacomaTacomaWA 98402USA

A novel Mg-based bimetal reagent(Mg/Cu)was used as an enhanced reductive system to degrade insensitivemunition 2,4-dinitroanisole(DNAN),a contaminant found in *** ofDNANwas significantly impacted by dissolved oxygen and studied in anoxic and oxic bimetal systems(i.e.,purging with N2,air,or O_(2) gas).Degradation occurred through sequential nitroreduction:first one nitro group was reduced(ortho or para)to form short-lived intermediates 2-amino-4-nitroanisole or 4-amino-2-nitroanisole(2-ANAN or 4-ANAN),and then subsequent reduction of the other nitro group formed 2,4-diaminoanisole(DAAN).The nitro-amino intermediates demonstrated regioselective reduction in the ortho position to 2-ANAN;Regioselectivity was also impacted by the anoxic/oxic *** O_(2)-purging DNAN degradation rate was slightly enhanced,but most notably O_(2) significantly accelerated DAAN *** also further degraded only in the oxygenated Mg/Cu *** of DNAN byproducts to the reagent occurred regardless of anoxic/oxic condition,resulting in a partition of carbon mass between the adsorbed phase(27%-35%)and dissolved phase(59%-72%).Additional surface techniqueswere applied to investigate contaminant interaction with *** functional theory(DFT)calculations identified preferential adsorption structures for DNAN on Cu with binding through two O atoms of one or both nitro groups.X-ray absorption spectroscopy(XAS)measurements determined the oxidation state of catalyticmetal Cu and formation of a Cu-O-N bond during *** desorption ionization mass spectrometry(LDI-MS)measurements also identified intermediate 2-ANAN adsorbed to the bimetal surface.

关键词： Insensitive munition Magnesium bimetal Reductive degradation Adsorption Surface analysis DFT DNAN Oxic

Ileal pouch surgery for ulcerative colitis

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World Journal of Gastroenterology 2007年第24期13卷 3288-3300页

作者： simon p Bach Neil J Mortensen Department of Colorectal Surgery John Radcliffe Hospital Oxford OX3 9DU United Kingdom

Ulcerative colitis (UC) is a relapsing and remitting disease characterised by chronic mucosal and submucosal inflammation of the colon and rectum. Treatment may vary depending upon the extent and severity of inflammation. Broadly speaking medical treatments aim to induce and then maintain remission. Surgery is indicated for inflammatory disease that is refractory to medical treatment or in cases of neoplastic transformation. Approximately 25% of patients with UC ultimately require colectomy. Ileal pouch-anal anastomosis (IpAA) has become the standard of care for patients with ulcerative colitis who ultimately require colectomy. This review will examine indications for IpAA, patient selection, technical aspects of surgery, management of complications and long term outcome following this procedure.

关键词： Ulcerative colitis Ileal pouch Ileal pouch anal anastomosis

In vitro corrosion behaviour of phenolic coated nickel–titanium surfaces

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Biosurface and Biotribology 2020年第1期6卷 25-30页

作者： simon Longela Athanasios Chatzitakis IRC Tz P.O.Box 106048Dar es SalaamTanzania Department of Chemistry Centre for Materials Science and NanotechnologyUniversity of OsloFERMiOGaustadalléen 21NO-0349 OsloNorway

The biocompatibility of implantable nickel-titanium biomaterials relies on the quality of their *** this study,nickel-titanium surfaces are coated with phenolic thin films of tannic acid and pyrogallol with the purpose of studying their corrosion resistance in physiological *** tests are performed:the open-circuit potential test,potentiodynamic polarisation and potentiostatic electrochemical impedance *** measurements are scrutinised in order to gain knowledge concerning the kinetics of the cathodic and anodic reactions,while the open-circuit potentials and impedance spectroscopy help to study the electrolyte-surficial *** is found that coating nitinol with polyphenols results in the depletion of the native oxide layer and thus a decrease of corrosion *** treated nitinol surfaces(with a corrosion rate of 0.119 mm/year)are half as electrochemically corrosion resistive as tannic acid-coated ***,it is proposed that tannic treated nitinol would be a better option if implanted on biomaterial surfaces.

关键词： spectroscopy titanium phenolic

Natural regeneration in logging gaps of different sizes in Subri River Forest Reserve(Ghana)

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Journal of Forestry Research 2022年第4期33卷 1157-1174页

作者： Maame Esi Hammond Radek pokorný simon Abugre Augustine Gyedu Department of Silviculture Faculty of Forestry and Wood TechnologyMendel University in BrnoZemědělská361300 BrnoCzech Republic Department of Forest Science School of Natural ResourcesUniversity of Energy and Natural ResourcesP.O.Box 214SunyaniGhana Forest Services Division(FSD) P.M.BKumasiGhana

Subri River Forest Reserve(SR)is the most extensive forest area in Ghana with an accompanying rich floral *** the years,logging from both legally prescribed and illegal operations remain the predominant forest disturbance in *** creation following logging is crucial in determining tree species composition and ***,the study evaluated the composition and diversity of naturally regenerated tree species in logging gaps of different sizes and,again examined the roles of these tree species in fulfilling the economic and ecological agenda of sustainable forest management after logging in *** gaps were randomly selected:4 each were grouped into small size(≤200 m^(2)),medium size(201–300 m^(2)),and large size(≥300 m^(2)).Data were gathered from 1 m^(2) circular area at gap centres and repeatedly inside 1 m width strip along 20 m individual N-S-E-W *** diversity differed significantly between gap *** diversity indices were measured in large size *** sizes shared similar *** were significant differences among various height groupings of tree species across all three gap *** preferred medium to large size gaps,while shadetolerant tree species preferred small size gaps for their *** and Lower Risk Near Threatened tree species under Conservation Status and,premium and Commercial tree species under Utilisation Status preferred small size gaps for their proliferation and ***,we recommend the single tree-based selective logging for ensuring creations of small to medium size(200–300 m^(2))gaps through adjustments to the logging permit process,revision of Allocation Quota permit,strict adherence to the 40-year polycyclic selection system,along with more dedicated enforcement and *** along these protocols would tremendously facilitate natural regeneration of different suites of timber species resulting in the improvement of the overall biodiversity conservat

关键词： Conservation status Gap size Diversity Logging Natural regeneration Subri River Forest Reserve Tree species Utilisation status

The complexity of sediment recycling as revealed by common pb isotopes in K-feldspar

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Geoscience Frontiers 2018年第5期9卷 1515-1527页

作者： simon p.Johnson Christopher L.Kirkland Noreen J.Evans Brad J.McDonald Huntly N.Cutten Geological Survey of Western Australia Mineral House100 Plain StreetEast PerthWestern Australia6004Australia Centre for Exploration Targeting-Curtin Node The Institute for Geoscience ResearchDepartment of Applied GeologyWestern Australian School of MinesCurtin UniversityPerthWestern Australia6102Australia John de Laeter Centre The Institute for Geoscience ResearchDepartment of Applied Geology and Applied PhysicsCurtin UniversityPerthWestern Australia6102Australia

Detrital zircon U-pb geochronology has become the gold standard in evaluating source to sink relationships in sedimentary basins. However, the physical and chemical robustness of zircon, which make it such a useful mineral for provenance studies, is also a hindrance as zircon can be recycled through numerous sedimentary basins, thus obscuring the first cycle source to sink relationship. An elegant approach to addressing this potential issue is to compare the pb isotope composition of detrital K-feldspar, a mineral which is unlikely to survive more than one erosion-transport-deposition cycle, with that of magmatic K-feldspar from potential basement source terranes. Here we present new in situ pb isotope data on detrital K-feldspar from two proterozoic arkosic sandstones from Western Australia, and magmatic K-feldspar grains from potential igneous source rocks, as inferred by the age and Hf isotope composition of detrital zircon grains. The data indicate that the detrital zircon and K-feldspar grains could not have been liberated from the same source rocks, and that the zircon has most likely been recycled through older sedimentary basins. These results provide a more complete understanding of apparently simple source to sink relationships in this part of proterozoic Western Australia.

关键词： Detrital zircon K-feldspar pb isotopes Sediment provenance Sediment recycling

Reading Text Under Normal and Disappearing presentation Conditions

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心理与行为研究 2004年第3期2卷 505-512页

作者： simon p. Liversedge Department of psychology University of Durham Durham DH1 3LE UK

In this article I discuss data from a series of experiments in which readers’ eye movements were recorded as they processed sentences in which each word disappeared or was masked 60ms after fixation onset. We used this paradigm to investigate whether we could induce a gap effect during reading, and how visual and linguistic factors affected eye movements under these conditions. The data showed that no gap effect occurred in our experiment. Overall reading times were the same under normal and disappearing presentation conditions. However, readers did adopt a strategy of making fewer but longer fixations when the text disappeared than when it did not. Additionally, clear frequency effects occurred regardless of whether the text was presented normally or disappeared. This finding indicates that while the visual uptake of information is important, cognitive processes associated with the lexical identification of words are a primary influence on when readers move their eyes during reading. The findings are taken to support the E-Z Reader model of eye movement control.

关键词： eye movements disappearing text reading.