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Coarse to Fine: The Role of Severe Plastic Deformation in Advancing Titanium-Based Medical Implants - A Comprehensive Review

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 295-306页

作者： dr.gana R Mihajlović Bojan I Međo Ivana Lj Cvijović-Alagić Veljko R Djokić Faculty of Technology and Metallurgy University of BelgradeKarnegijeva 411120 BelgradeSerbia Vinča Institute of Nuclear Sci-ences-National Institute of the Republic of serbia University of Belgrade11001BeogradSerbia Innovation Centre of the Faculty of Technology and Metallurgy Karnegijeva 411120 BelgradeSerbia

This paper describes severe plastic deformation(SPD)procedures,which are utilized to form an ultrafine-grained structure in metallic *** the SPD process,a solid material sample is subjected to very high loads without a significant change in sample *** the present work,the high-pressure torsion(HPT)process,as one of the SPD techniques,which achieves a high degree of deformation and ensures refinement of the microstructure,will be discussed in more *** that grain size control is accepted as a method to obtain materials with desired characteristics,an overview of the properties of ultrafine-grained titanium-based biomaterials to be used in medicine is ***,particular attention is dedicated to the influences of HPT process parameters,primarily hydr.static pressure,and number of revolutions during torsion,on the grain size and physical and mechanical characteristics(modulus of elasticity,microhardness,and tensile properties),corrosion resistance,and biocompatibility of the titanium-based biomaterials.A review of the literature indicates that titanium-based materials obtained by the SPD process show improved mechanical and physical properties without losing biocompatibility and corrosion resistance,which suggests that these methods of obtaining implants are something that should be further developed in the future.

关键词： high-pressure torsion process ultrafine-grained titanium-based materials electrochemical anodization physical properties mechanical properties

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Prolonged intermittent theta burst stimulation restores the balance between A_(2A)R-and A_(1)R-mediated adenosine signaling in the 6-hydr.xidopamine model of Parkinson's disease

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Neural Regeneration Research 2025年第7期20卷 2053-2067页

作者： Milica Zeljkovic Jovanovic Jelena Stanojevic Ivana Stevanovic Milica Ninkovic Tihomir V.Ilic Nadezda Nedeljkovic Milorad dr.gic Laboratory for Neurobiology Department of General Physiology and BiophysicsFaculty of BiologyUniversity of BelgradeBelgradeSerbia Medical Faculty of Military Medical Academy University of DefenceBelgradeSerbia

An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's *** therapeutic approaches fail to alter disease progression,demonstrating the need for novel approaches in *** transcranial magnetic stimulation is a non-invasive approach that has been shown to improve motor and non-motor symptoms of Parkinson's ***,the underlying mechanisms of the beneficial effects of repetitive transcranial magnetic stimulation remain *** purpose of this study is to investigate the extent to which the beneficial effects of prolonged intermittent theta burst stimulation in the 6-hydr.xydopamine model of experimental parkinsonism are based on modulation of adenosine-mediated *** with unilateral 6-hydr.xydopamine lesions underwent intermittent theta burst stimulation for 3 weeks and were tested for motor skills using the Rotarod ***,quantitative reverse transcription polymerase chain reaction,immunohistochemistry,and biochemical analysis of components of adenosine-mediated signaling were performed on the synaptosomal fraction of the lesioned caudate *** intermittent theta burst stimulation improved motor symptoms in 6-hydr.xydopamine-lesioned animals.A 6-hydr.xydopamine lesion resulted in progressive loss of dopaminergic neurons in the caudate *** with intermittent theta burst stimulation began 7 days after the lesion,coinciding with the onset of motor *** treatment with prolonged intermittent theta burst stimulation,complete motor recovery was *** improvement was accompanied by downregulation of the e N/CD73-A_(2A)R pathway and a return to physiological levels of A_(1)R-adenosine deaminase 1 after 3 weeks of intermittent theta burst *** results demonstrated that 6-hydr.xydopamine-induced degeneration reduced the expression of A_(1)R and elevated the expression of A_(2A)***

关键词： A_(1)R A_(2A)R adenosine receptors adenosine ecto-5′-nucleotidase intermittent theta burst stimulation non-invasive brain stimulation Parkinson's disease purinergic signalling

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Trace element study in Tisa River and Danube alluvial sediment in serbia

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International Journal of Sediment Research 2013年第2期28卷 234-245页

作者： Sanja M.SAKAN Nenad M.SAKAN dr.gana S.DORDEVIC ICTM Department of ChemistryUniversity of BelgradeNjegoseva 12P.O.Box 81511001 BelgradeSERBIA Dr. Institute of Physics University of Belgrade11081 BelgradeP.O.Box 68SERBIA Dr.

The contaminated sediment serves as a long-term source of toxic elements,since that mobility and transport in the environment of these elements are strongly influenced to associated solid *** this study,the modified Tessier sequential extraction procedure was applied for the fractionation of Cd,As,Hg,Cu,Zn,Cr,Pb,Ni and V in the sediments(Tisa River and canal sediments - Danube alluvial formation),to obtain an overall classification of trace element pollution in these areas through its spatial *** of this region are important due to the widespread occurrence of metal mining activities throughout the Tisa and Danube dr.inage basins and possibilities of contamination with toxic elements at studies *** steps of the sequential extraction procedure partitioned elements into CHCOONHextractable(F1),NHOH·HC carbonate extractable and easily reducible(F), HCO/(NH)COmoderately reducible(F3),HO-HNOorganic extractable(F4),and HCl acid soluble residue (F5).Analyses of the extracts were performed by flame atomic absorption *** indicate the degree of risk of toxic elements,risk assessment code and contamination factor have been *** results of partitioning study indicate that more easily mobilized forms(metals in adsorbed/exchangeable/carbonate forms or bound to amorphous Fe and Mn oxyhydr.xides and Fe and Mn oxides) were predominant for copper,zinc,cadmium and lead,which can be used as indicators for input from anthropogenic *** contrast,the largest amount of chromium and nickel were associated with the inert fraction,which reduced their solubility and rendered them immobile under natural conditions and indicative of natural *** of remaining portion of metals was bound to ferromanganese oxides *** is concluded that sequential extraction results proved useful to distinguish between anthropogenic and geochemical sources of elements in the sediments.

关键词： Sequential extraction Modified Tessier procedure Metals Metalloids Risk assessment code

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Macroscopically-Zoned Grandite from the Garnetite Skarn of Meka Presedla(Kopaonik Mountain,serbia)

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Acta Geologica Sinica(English Edition) 2012年第2期86卷 393-406页

作者： Pavle TANCIC Predr.g VULIC Reinhard KAINDL Bernhard SARTORY Radovan DIMITRIJEVIC Geological Institute of serbia BelgradeSerbia Department of Crystallography Faculty of Mining and GeologyUniversity of BelgradeBelgradeSerbia 3 Institute of Mineralogy and Petrography University of InnsbruckInnsbruckAustria

The macroscopically-zoned grandite from the garnetite skarn of Meka Presedla （Kopaonik Mountain, serbia） was studied with optical microscopy, electron microprobe analysis （EMPA）, Fourier transform infra-red （FT-IR）, and Raman methods. The EMPA results indicate that the main core-rim compositional variations （Ca2.93-2.97Mn0.05-0.06Mg0.00-0.01AI1.14-L26 Fe0.72-0.83 Ti0.00-0.02Si2.97-3.02012） slightly differ along the zones, showing evidence for a quasi-cyclic alternation of the oscillatory zoning nature. Among this, considerable variation is observed only by the AI-Fe3＋ substitutions in the octahedr.l site. The EMPA also indicate that the grandite zones compositionally vary, mostly within ＋1 and ±2 mol% of the homogeneity level range, that is, Grs64±1Adr.36±1SpS2 （A）, Grs62±1Adr.38±1Sps2 （B）, Grs59±2Adr.0±2Sps2 （C）, Grs58±2Adr.1±2Sps2 （D）, and Grss±1Adr.1±1Sps2 （E）. Therefore, the investigated garnet can be considered as relatively highly homogeneous. The majority of compositions lie within the narrow miscibility region of 0.58±2〈XGrs〈0.64±1, without gaps, and with only three outliers near the zone boundaries of approximately 0.38〈XGrs〈0.52. FT-IR and Raman bands are almost constant within the zones and adequate to the chemical compositions. All of the zones should be considered as anhydr.us. From the results, formation temperatures between -600 and 720℃ and pressures 0f-2-3 kbars, are derived. Among five possible causes for the slightly optical anisotropy of grandite, three were reconsidered, and consequently rejected.

关键词： grandite anisotropy compositional variation zone homogeneities miscibility region

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Sustainable development of lignite production on open cast mines in serbia

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Mining Science and Technology 2009年第5期19卷 679-683页

作者： DANICIC Darko MITROVIC Slobodan PAVLOVIC Vladimir KOVACEV Sava Kolubara Metal D. Djurdjevica 32 Vreoci 11560 Serbia Electric Power of serbia Vojvode Stepe 412 Belgrade 11000 Serbia Faculty of Mining and Geology University of Belgrade Belgrade 11000 Serbia

Energy sector represents a key industrial branch for national, environmental and economic success. With its exclusive access to domestic deposits, lignite industry represents a guarantor of reliable raw materials, offering long-term supply security based on verified reserves. Currently operated coalmines in serbia (Kolubara and Kostolac) have production around 36 million tons of lignite, and over 108 million m3 of overburden. Consequently, sustainability of lignite production requires cost reduction and environmental protection, as well as capacity increase. In order to rationalise, and increase efficiency of serbian lignite mines, it is necessary to focus the activities on major issues shown within the triangle of energy policy objectives (security of supply, competi- tive prices and environmental protection). Production process optimisation singled out several special programs. Equipment revi- talization and modernization is necessary taking into account that majority of the currently operated machinery has a life up to 25 years. Production process automation would enable high level of technical operation in the field of open cast mines management. Lack of coal quality uniformity is the permanent problem resulting by great amounts of coal reserves to be used uneconomically. Planning and training at all levels and finally cooperative software for business procedures and work order management. The measures suggested are a key precondition for maintaining competitive position of lignite production on international level.

关键词： lignite production revitalization automation homogenization

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Can the desiccation of forests in Tara National Park (serbia) be attributed to the effects of a dr.ught period?

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Journal of Forestry Research 2024年第6期35卷 220-229页

作者： GoranČešljar NevenaČule IlijaĐorđević Saša Eremija Natalija Momirović Marko Tomić Filip Jovanović Institute of Forestry Kneza Višeslava 3Belgrade 11030Serbia Tara National Park Milenka Topalovića 3Bajina Bašta 31250Serbia

Forest ecosystems within national parks are threatened by various biotic and abiotic *** deter-mine the causes of the desiccation and death of trees in mixed coniferous and deciduous forests of Tara National Park(TNP),serbia,we monitored defoliation and mortality of individual trees in permanent experimental *** on the desiccation of a large number of trees were gathered by determining the total volume of dr. trees and areas of forests under dr.ing *** two sets of data were combined to determine the impact of climatic events,primarily dr.ught periods,on the desiccation of *** data from the International Co-operative Program on Assessment and Monitoring of Air Pollution Effects on Forests(ICP Forests)with TNP data helped relate forest desiccation to climate *** climate signals were identified by monitoring tree defoliation changes in two permanent experimental plots,and then assessed for their influence on tree desicca-tion in the entire national *** standardized precipita-tion evapotranspiration index(SPEI)was used for a more detailed analysis of the dr.ught *** the lack of climate data for a certain period,the SPEI index revealed a link between climate variables and the defoliation and desic-cation of ***,the desiccation of trees was preceded by a long dr.ught *** mixed conifer-ous-deciduous forests are often considered less vulnerable to natural influences,this study suggests that forest ecosystems can become vulnerable regardless of tree species composi-tion due to multi-year *** findings contribute to a better understanding of important clues for predicting pos-sible future desiccation of *** monitoring of the state of forests and of more permanent experimental plots in national parks could provide better quality data and timely responses to stressful situations.

关键词： Forest ecosystems Extreme climate events dr.ught Defoliation Monitoring

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Sedimentation History of Neogene Lacustrine Sediments of Sueoka Bela Stena Based on Geochemical Parameters(Valjevo-Mionica Basin,serbia)

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Acta Geologica Sinica(English Edition) 2008年第6期82卷 1201-1212页

作者： Aleksandr. AJNOVI Vladimir SIMI Branimir JOVANIEVI Olga CVETKOVI Radovan DIMITRIJEVI Nenad GRUBIN Center of Chemistry IChTM11000 BelgradeSerbia Faculty of Mining and Geology University of Belgrade11000 BelgradeSerbia Faculty of Chemistry University of Belgrade11000 BelgradeSerbia Rio Tinto Exploration Bulevar A VNOJ-a 7111000 BelgradeSerbia

Sediments of the western part of the Valjevo-Mionica basin （serbia） were examined both geochemically and mineralogically to explain, on the basis of their sedimentologicai characteristics, the causes of changes in their qualitative and quantitative composition. A total of 62 samples obtained from the dr.llhole at depths up to 400 m was investigated. Using correlation of the obtained data, six geochemical zones were defined, two of which being specially distinguished by their mineralogical, geochemical and sedimentological characteristics. The first one, upper zone A, consists of banded marlstones interbedded with clay and oil shales and is characterized by presence of analcite and searlesite. These minerals and very high contents of Na20 indicate sedimentation in alkaline conditions with increased salinity in arid climate. That provided pronounced water stratification, as well as higher bioproductivity in the basin and sedimentary organic matter preservation. Therefore, the zone A sediments are characterized by high organic matter contents of the type which provides good potential for production of liquid hydr.carbons. Another specific zone, zone F, contains sediments with very high MgO, K2O and Li concentrations. Their geochemical correlation, as well as almost complete absence of illite in this zone, indicates the presence of interstratified clay mineral type illite-saponite （lithium-bearing Mg-smectite）.

关键词： lacustrine sediments geochemistry searlesite statistical analysis

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Age-specific causes of upper gastrointestinal bleeding in childr.n

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World Journal of Gastroenterology 2023年第47期29卷 6095-6110页

作者： Marija Kocic Petar Rasic Vuk Marusic dr.gan Prokic Djordje Savic Maja Milickovic Ivana Kitic Tanja Mijovic Adr.jan Sarajlija Department of Gastroenterology Hepatology and NutritionMother and Child Health Care Institute of Serbia“Dr.Vukan Cupic”Belgrade 11000Serbia Department of Abdominal Surgery Mother and Child Health Care Institute of Serbia“Dr.Vukan Cupic”Belgrade 11000Serbia Institute of Epidemiology Faculty of MedicineUniversity of BelgradeBelgrade 11000Serbia Faculty of Medicine University of BelgradeBelgrade 11000Serbia Pediatric Day Care Hospital Department Mother and Child Health Care Institute of Serbia“Dr.Vukan Cupic”Belgrade 11000Serbia Department of Abdominal Surgery Mother and Child Health Care Institute of Serbia“Dr.Vukan Cupic”Radoja Dakica 6-8Belgrade 11000Serbia

The etiology of upper gastrointestinal bleeding(UGIB)varies by age,from newborns to adolescents,with some of the causes overlapping between age *** particular causes such as vitamin K deficiency and cow’s milk protein allergy are limited to specific age groups,occurring only in neonates and infants,others such as erosive esophagitis and gastritis may be identified at all ***,the incidence of UGIB is variable throughout the world and in different hospital *** North America and Europe,most UGIBs are nonvariceal,associated with erosive esophagitis,gastritis,and gastric and duodenal *** recent years,the most common causes in some Middle Eastern and Far Eastern countries are becoming similar to those in Western ***,variceal bleeding still predominates in certain parts of the world,especially in South *** most severe hemorrhage arises from variceal bleeding,peptic ulceration,and disseminated intravascular *** is a credible indicator of a UGI source of bleeding in the majority of *** familiar with the most likely UGIB causes in specific ages and geographic areas is especially important for adequate orientation in clinical settings,the use of proper diagnostic tests, and rapid initiation of the therapy. The fundamental approach to the management of UGIBincludes an immediate assessment of severity, detecting possible causes, and providing hemodynamic stability,followed by early endoscopy. Unusual UGIB causes must always be considered when establishing a diagnosis inthe pediatric population because some of them are unique to childr.n. Endoscopic techniques are of significantdiagnostic value, and combined with medicaments, may be used for the management of acute bleeding. Finally,surgical treatment is reserved for the most severe bleeding.

关键词： Upper gastrointestinal bleeding Age-specific Epidemiology Pediatric Unusual cause

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Transcatheter Ventricular Septal Defect Closure with Nit-Occlud LêVSD Device—Five Years’Experience and Literature Review

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Congenital Heart Disease 2023年第3期18卷 361-371页

作者： Ivana B.Cerović Vladislav A.Vukomanović Jovan Lj.Košutić Mila S.Stajević Sanja S.Ninić Saša S.Popović Ivan D.Dizdarević Staša D.Krasić Sergej M.Prijić Cardiology Department Mother and Child Health Institute of Serbia“Dr VukanČupić”Belgrade11070Serbia Faculty of Medicine University of BelgradeBelgrade11070Serbia

Introduction:Transcatheter closure is an alternative to ventricular septal defect(VSD)occlusion ***-Occlud LêVSD coil is a new device yet to be *** study aimed to evaluate immediate and midterm results after transcatheter closure with the Nit-Occlud LêVSD ***:The retrospective analysis included 30 patients with VSD referred for closure during the period from October 2015 to December ***:At the time of intervention,the patients’mean age and body weights were 7.5±5.6 years and 29.3±19.1 *** majority of the defects had perimembranous location(24/30),four defects had muscular and two outlet subaortic *** mean effective right-side diameter of the VSDs was 3.6±1.3 *** ventricular fibrillation,device embolization,and hemolysis developed in different patients and were successfully *** of the patients had a complete atrioventricular *** coil was successfully placed in 25/30(83.3%)*** majority of the devices were 10 mm×6 mm(11/25)and 12 mm×8 mm(8/25)in *** patients required the implantation of a second *** follow-up period was 2.1±1.4 *** VSD closure was achieved in 48%of cases immediately after the intervention,74%during 2.1±1.6 months after the procedure,and 81%over *** remaining patients had a trivial residual *** the follow-up,approximately one-third of patients developed trivial aortic and mitral valve regurgitation,and half of the patients acquired trace/mild tricuspid ***(z-score)left ventricular end-diastolic diameter(0.15±0.37 vs.0.92±0.82,p=0.005)and left atrium dimension(0.47±0.58 vs.1.89±1.11,p=0.005),as well as the left atrium to aortic root ratio(1.2±0.1 vs.1.4±0.2,p=0.005)showed a significant decrease over follow-up related to the period before ***:Intervention with Nit-OccludLêVSD coil showed appropriate results regarding VSD closure rate,complications,and chamber *** introduction of t

关键词： Ventricular septal defect transcatheter device childr.n

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Decision Support for Integrated Management of Local-Level Adaptation to Climate Changes: The Case of serbia

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International Journal of Disaster Risk Science 2021年第4期12卷 479-494页

作者： Petar Vranić Srđan Glišović Lazar Velimirović Mathematical Institute of the serbian Academy of Sciences and Arts 11001BelgradeSerbia Faculty of Occupational Safety in Niš University of Niš18000NišSerbia

Projected climate changes will additionally increase the already significant risk of natural hazard-related disasters in serbia and the west Balkan region as a *** is about to introduce the strategy for climate change adaptation and ***,a national decision-support system for implementation of the climate change law and strategy is yet to be *** study contributes to the implementation of adaptation policies at subnational levels by development of a decision-support model for local-level management of the climate change adaptation *** study explores the potential for synergetic application of multicriteria decision making analysis and probabilistic reasoning methods by focusing on Bayesian networks,analytical hierarchy processes,and geographic information systems for selection of priority adaptation *** study was based on the formation of causal chains,which enable linking management decisions and socioeconomic or biophysical consequences into articulated sequences of conditional relationships.A model was tested in the forestry sector,and it clearly pointed out development of an early warning system and planning of water intake basins as priority adaptation *** the results are shown as a probability distribution for each alternative solutions,the model can assist decision makers with prompt evaluation of various scenarios.

关键词： Bayesian networks Climate change adaptation Multicriteria decision-making serbia Wildfire risk

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