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Enhanced air-coupled impact echo technique by phase analysis of signals from multiple sensors

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 297-310页

作者： Najjiya Almallah nenad Gucunski New Jersey Department of Transportation New Jersey 08625USA Department of Civil&Environmental Engineering Rutgers University-New BrunswickNJ 08854USA

This paper presents an air-coupled impact echo(IE)technique that relies on the phase spectrum of the collected data to find the frequencies corresponding to the reflections from *** proposed technique takes advantage of the fact that the IE compression wave is not a propagating wave,but it is the 1st order symmetrical(s1)mode Lamb wave at zero group velocity(s1-ZGV).Therefore,it searches the phase spectra of the data collected by multiple sensors to locate the frequency corresponding to the lowest phase *** a result,the technique reduces the effect of propagating waves,including the direct acoustic wave and ambient *** is named the Constant Phase IE(CPIE).The performance of the CPIE is experimentally compared with the regular amplitude spectrum-based IE technique and two other multisensor IE *** CPIE shows a performance advantage,especially in a noisy environment.

关键词： nondestructive testing(NDT) nondestructive evaluation(NDE) bridge inspection bridge evaluation impact echo bridge delamination concrete bridge deck air-coupled sensing MEMs

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Geochemistry of sediments from the Lopare Basin(Bosnia and Herzegovina):Implications for Paleoclimate,Paleosalinity,Paleoredox and Provenance

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Acta Geologica sinica(English Edition) 2020年第5期94卷 1591-1618页

作者： AleksandraŠAJNOVIĆ nenad GRBA Franz NEUBAUER Milica KAŠANIN-GRUBIN Ksenija sTOJANOVIĆ nenad PETKOVIĆ Branimir JOVANČIĆEVIĆ University of Belgrade Center of ChemistryICTMStudentski trg 12-1611000 BelgradeSerbia University of Novi sad Faculty of SciencesDepartment of ChemistryBiochemistry and Environmental ProtectionTrg Dositeja Obradovica 321000 Novi SadSerbia Paris Lodron University of salzburg Department of Geography and GeologyHellbrunnerstrasse 345020 SalzburgAustria University of Belgrade Faculty of ChemistryStudentski trg 12-1611000 BelgradeSerbia Rio Tinto–Rio sava Exploration Takovska 4511000 BelgradeSerbia

A combined inorganic and organic geochemical study was carried out on marls and mudstones collected from the Lower Miocene Lopare Basin,Bosnia and Herzegovina.A total of 46 samples collected from two boreholes,Pot 1(depth of 193 m)and Pot 3(depth of 344 m),showed that element abundances like boron(B),lithium(Li),strontium(sr),uranium(U),chromium(Cr),nickel(Ni),magnesium(Mg),sodium(Na)and calcium(Ca)are much higher than average than in the upper continental crust(UCC).Chemical composition indicates at least two sources:(i)Mesozoic ophiolites occurring in the north of the investigated area,and(ii)dacito-andesitic pyroclastics(Mesozoic to Cenozoic).Lopare Basin sedimentation was influenced by strong evaporation resulting in a partly hypersaline lake,which formed during a warm climatic period,probably during the Miocene Climatic Optimum.A brief episode of humid climate conditions resulted in the basin fillingup and deposition of felsic sediments enriched in thorium(Th).Organic geochemistry shows that the majority of studied sediments contains predominantly immature to marginally mature algal organic matter(OM).The biomarker patterns are generally in agreement with the geological history of the Lopare Basin and inorganic and mineralogical ***,the molecular distribution of n-alkanes as reliable climatic andδ-MTTC as paleosalinity indicators do not support this conclusion.

关键词： geochemistry provenance analysis paleoenvironmental conditions salinity/hypersalinity biomarker Lopare Basin Bosnia and Herzegovina

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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 Dragana 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 drainage 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 oxyhydroxides 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

Multicriteria to estimate the environmental risk of sediment from the Obedska Bog(Northern serbia),a reservation area on UNEsCO's list

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International Journal of sediment Research 2020年第5期35卷 527-539页

作者： Dejan Kr?mar nenad Grba Marijana Kragulj Isakovski Nata?a Varga Jelena spasojevi? Jasmina Agbaba Bozo Du?an Dalmacija University of Novi sad Faculty of sciences Department of ChemistryBiochemistry and Environmental Protection

The objective of this current study is to compare related sediment legislation standards and norms to the diversity and influence of anthropogenic and natural(geogenic) sources of pollution in the investigated fluvial relief test site region of the Obedska *** metals(nickel(Ni).zinc(Zn),cadmium(Cd),copper(Cu) and lead(Pb) except chromium(Cr)) and arsenic(As) have higher values than the Upper Continental Crust(UCC) for loess *** sharp leaps in the enrichment factor(r) suggested "indicators of anthropogenic metal pollution" for Cd,Cu(r> 5.0) and Zn,Ni(r> 1.0) for this *** addition,the Chemical Proxy of Alteration(CPA,60-95) from the unique Jadar block terrane and neighbouring representative catchment areas,confirmed moderate to higher intensity of *** Component Analysis/Factor Analysis(PCA/FA) and cluster analysis suggest that Ni,Zn,Cu and Cd are derived from several anthropogenic sources,whereas As is convincingly of geogenic origin,and Pb and Cr exhibit dual *** sum of 16 *** Protection Agency Polycyclic Aromatic Hydrocarbons(EPA PAHs) indicated heterogenic sources,but minor effects to *** results of the current investigation indicated intensive and highly diffuse sources of pollution in this United Nations Educational,scientific and Cultural Organization [UNEsCO's] *** outcomes indicate that Cu should be added to the European Union [EU] watch list of emerging contaminants.

关键词： Priority substances in sediment Contamination criteria Multivariate statistical techniques Heterogeneous sources

sARs-CoV Genome Polymorphism: A Bioinformatics study

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Genomics, Proteomics & Bioinformatics 2005年第1期3卷 18-35页

作者： Gordana M. Pavlovi-La■eti nenad s. Miti Andrija M. Tomovi Mirjana D. Pavlovi Milo V.Beljanski Faculty of Mathematics University of Belgrade 11001 Belgrade Serbia and Montenegro Faculty of Mathematics University of Belgrade 11001 Belgrade Serbia and MontenegroFriedrich MiescherInstitute for Biomedical Research CH-4058 Basel Switzerland Institute of General and Physical Chemistry11001 Belgrade Serbia and Montenegro.Institute of General and Physical Chemistry11001 Belgrade Serbia and Montenegro.

A dataset of 103 sARs-CoV isolates （101 human patients and 2 palm civets） was investigated on different aspects of genome polymorphism and isolate classification. The number and the distribution of single nucleotide variations （sNVs） and insertions and deletions, with respect to a “profile”, were determined and discussed （“profile” being a sequence containing the most represented letter per position）. Distribution of substitution categories per codon positions, as well as synonymous and non-synonymous substitutions in coding regions of annotated isolates, was determined, along with amino acid （a.a.） property changes. similar analysis was performed for the spike （s） protein in all the isolates （55 of them being predicted for the first time）. The ratio Ka/Ks confirmed that the s gene was subjected to the Darwinian selection during virus transmission from animals to humans. Isolates from the dataset were classified according to genome polymorphism and genotypes. Genome polymorphism yields to two groups, one with a small number of sNVs and another with a large number of sNVs, with up to four subgroups with respect to insertions and deletions. We identified three basic nine-locus genotypes： TTTT/TTCGG, CGCC/TTCAT, and TGCC/TTCGT, with four subgenotypes. Both classifications proposed are in accordance with the new insights into possible epidemiological spread, both in space and time.

关键词： sARs Coronavirus single nucleotide polymorphism insertions deletions spike protein phylogenesis

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Lyme Borrelia as the etiological factor in three cases of primary inflammatory choriocapillaropathies

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International Journal of Ophthalmology(English edition) 2017年第12期10卷 1940-1944页

作者： svetlana V. Jovanovic nenad T. Petrovic Maja LJ. Zivkovic Zorica G. Toncic Tatjana s.sarenac Vulovic Department of Ophthalmology Faculty of Medical SciencesUniversity of KragujevacKragujevac 34000Serbia Department of Ophthalmology Faculty of MedicineUniversity of NisNis 18000Serbia Pediatric Institute Clinical Center of MontenegroPodgorica 81000Montenegro

Citation： Jovanovic sV, Petrovic NT, Zivkovic MLJ, Toncic ZG, sarenac Vulovic Ts. Lyme Borrelia as the etiological factor in three cases of primary inflammatory choriocapillaropathies, lnt J Ophthalmo12017 ; 10（12）... 详细信息

关键词： In Lyme Borrelia as the etiological factor in three cases of primary infl ammatory choriocapillaropathies Figure

Determining of Optimal Dimensions of Compliant spring Guiding systems

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Journal of Mechanics Engineering and Automation 2011年第6期1卷 455-463页

作者： nenad T. Pavlovic nenad D. Pavlovic Milos Milogevic Faculty of Mechanical Engineering Univesrity of Nis Nis 18000 Serbia

Compliant mechanisms transfer an input force or displacement to another point through elastic body deformation. The field of compliant mechanisms is expected to continue to grow as materials with superior properties are developed. The paper takes into consideration some typical spring guiding systems, being able to realize translating planar displacement of the link. some types of compound spring guiding systems, such as s-shaped guiding spring system, U-shaped guiding spring system and four spring guiding system with additional rigid-body link have been considered and analyzed as compliant structures. The mobility as well as guiding accuracy of the developed compliant mechanisms, that is, their capability to realize translating planar displacement of the link, have been researched, and the optimal dimensions of the mechanism have been determined in order to provide minimal guiding inaccuracy.

关键词： Compliant mechanisms spring guiding systems guiding accuracy mobility

Associations of cerebrospinal fluid amyloidogenic nanoplaques with cytokines in Alzheimer’s disease

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Translational Neurodegeneration 2021年第2期10卷 230-239页

作者： Mari Aksnes Hans Christian DAass Ann Tiiman Trine Holt Edwin Lars Terenius nenad Bogdanovic Vladana Vukojevic Anne-Brita Knapskog Department of Geriatric Medicine Institute of Clinical MedicineFaculty of MedicineUniversity of OsloOsloNorway Department of Medical Biochemistry Oslo University HospitalOsloNorway Department of Clinical Neurosciences(CNs) Center for Molecular Medicine CMM L8:01Karolinska InstitutetStockholmSweden Department of Geriatric Medicine The Memory ClinicOslo University HospitalOsloNorway Institute of Health and society Faculty of MedicineUniversity of OsloOsloNorway Norwegian National Advisory Unit on Ageing and Health Vestfold Hospital TrustTonsbergNorway Department of Neurobiology Care Science and Society(NVS)Division of Clinical GeriatricsKarolinska InstitutetHuddingeSweden

Background:The aggregation of amyloidβ(Aβ)is central in the pathogenesis of Alzheimer’s disease(AD).Recently it has been shown that specifically,larger,Thioflavin T-binding Aβaggregates are associated with increased neuroinflammation and cytokine *** study was aimed to quantify fibrillary amyloid aggregates,so-called nanoplaques,and investigate their relationship with cytokines in the cerebrospinal fluid(CsF).Methods:CsF was collected from 111 patients assessed for cognitive complaints at the Oslo University Hospital Memory *** patients were grouped based on their amyloid *** CsF nanoplaque concentration was quantified with the Thioflavin T-fluorescence correlation spectroscopy(ThT-FCs)*** levels of nine cytokines(eotaxin-1,granulocyte stimulating factor,interleukin[IL]-6,IL-7,IL-8,monocyte chemoattractant protein-1,gammainduced protein 10,macrophage inflammatory protein[MIP]-1α,and MIP-1β)were quantified with a magnetic bead-based multiplex assay and read on a Luminex Is 200 ***:There were 49 amyloid-negative and 62 amyloid-positive patients in the cohort;none of the cytokines differed significantly between the amyloid *** increased nanoplaque levels were associated with levels of MIP-1βbelow the lower limit of quantification,and with decreased levels of MIP-1αand *** associations remained significant when adjusted for age,sex,cognitive function,apolipoproteinε4 status and CsF core biomarker ***:The cytokine levels were not associated with amyloid status in this *** nanoplaque levels were negatively associated with MIP-1β,MIP-1αand IL-8,which is in line with recent findings suggesting that the upregulation of some cytokine markers has a protective role and is negatively associated with AD progression.

关键词： Alzheimer's disease Amyloid Amyloid beta peptides Amyloidogenic proteins Biomarkers Cerebrospinal fluid Cytokines Inflammation Fluorescence correlation spectroscopy Thioflavin T

Pain and function deteriorate in patients awaiting total joint arthroplasty that has been postponed due to the COVID-19 pandemic

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World Journal of Orthopedics 2021年第3期12卷 152-168页

作者： Jurek Rafal Tomasz Pietrzak Zia Maharaj Magdalena Erasmus Nkhodiseni sikhauli Josip nenad Cakic Lipalo Mokete Department of Orthopaedics University of the WitwatersrandJohannesburg 2193GautengSouth Africa Department of Orthopaedic surgery Charlotte Maxeke Johannesburg Academic HospitalJohannesburg 2193GautengSouth Africa Department of Orthopaedic surgery Life FourwaysJohannesburg 2193GautengSouth Africa

BACKGROUND Elective total joint arthroplasty(TJA)procedures have been postponed as part of the coronavirus disease 2019(COVID-19)response to avert healthcare system *** hip arthroplasty(THA)and total knee arthroplasty(TKA)procedures comprise the highest volume of elective procedures performed at health care facilities *** To determine the demand for TJA despite the pandemic and the impact of surgery postponement on physical and mental *** We conducted a prospective cross-sectional telephonic interview-based study on patients awaiting THA and TKA at an academic institution in south *** questionnaire consisted of four *** first section recorded baseline demographic data and medical co-morbidities,the length of time spent awaiting TJA,and the patients’desire to undergo elective surgery despite the COVID-19 *** 2 and section 3 assessed the patients’current physical and mental health,respectively,as a consequence of deferred surgical *** last section established the patients’perception of the healthcare system’s response to the COVID-19 pandemic and necessity to postpone elective *** received counseling and education on the current state of surgery during the COVID-19 pandemic and associated ***,patients were once again asked about their desire to undergo TJA during the COVID-19 *** We included 185 patients(65.95%female;mean age:50.28 years)awaiting TJA for a mean of 26.42±30.1 ***,88.65%of patients wanted TJA despite the COVID-19 *** awaiting TJA for 1-3 years were 3.3-fold more likely to want surgery than those waitings with comorbidities were 8.4-fold less likely to want TJA than those with no comorbidities(P=0.013).After receiving education,the patients wanting TJA decreased to 54.05%.Patients who changed their opinion after education had less insight on the increased morbidity(P=0.046)and mortality(P=0.001)asso

关键词： Total hip arthroplasty Total knee arthroplasty Elective surgery COVID-19 Waiting lists Primary total joint arthroplasty