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Journal of Geological Research 2020年第4期2卷 62-74页

作者： s.i.okonkwo s.O.idakwo federal university of technology owerrip.m.2.1526owerriimo statenigeria ibrahim badamasi babangida university lapaip.m.2.11lapainiger statenigeria

The geology of the Olode area, south-western Nigeria was investigatedpetrographically and geochemically in order to elucidate the mineralisationpotential of the rock units in the area. The area under study is generallychange to underlained by granite gneiss, mica schist and *** studies indicated prevalence of anhedral quartz (30 - 50%),plagioclase (14 - 20%), orthoclase (12 - 15%), muscovite (11 - 15%),tourmaline (6 - 10) and other minerals (8 - 11%) for the pegmatite. Thehigh value of siO2 and Al2O3 is consistent with the petrographical *** values and wide range in Ba (34 - 737 ppm) and Zr (3.8 - 132.6 ppm)strongly support a mixture of igneous and sedimentary. The bivariant plotsof Rb vs K/Rb, Zn vs K/Rb and Th vs K/Rb indicated a partial series offractionation, suggesting that the pegmatites are of rare element classeswhile granite gneiss and mica schist belong to the barren muscovite andrare element classes. This was supported by high ratios of K/Cs and K/Babut low Th/U values indicating distinctively low rare metal *** plot of Na2O/Al2O3 vs K2O/Al2O3 revealed an igneous precursor for allthe rock units. The negative Eu anomalies especially in the pegmatitic rockunit indicates fractionation and point toward a late metasomatic effect andtheir relatively weak negative Ce anomalies, also suggest their rare metalmineralization. The pegmatites, granite gneiss and mica schist of Olodearea considered as barren as all the samples plotted below the Gordiyenkosand Beus’ line of mineralization.

关键词： Pegmatite and associated rocks Geochemistry Mineralisation Gordiyenkos and Beus’line Olode

Erythrocyte sphingolipid species as biomarkers of Alzheimer's disease

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Journal of Pharmaceutical Analysis 2022年第1期12卷 178-185页

作者： Jericha Mill Vihar Patel Ozioma okonkwo Lingjun Li Thomas Raife Department of Chemistry University of Wisconsin-MadisonMadisonWI53706USA Department of Pathology and Laboratory Medicine University of Wisconsin School of Medicine and Public HealthMadisonWI53705USA Clinical science Center Wisconsin Alzheimer's Disease Research CenterUniversity of Wisconsin School of Medicine and Public HealthMadisonWI53792USA school of Pharmacy University of Wisconsin-MadisonMadisonWI53705USA

Diagnosing Alzheimer’s disease(AD)in the early stage is *** biomarkers can be of great value for population-based *** studies have been used to find potential biomarkers,but commonly used tissue sources can be difficult to *** objective of this study was to determine the potential utility of erythrocyte metabolite profiles in screening for *** some commonly-used sources such as cerebrospinal fluid and brain tissue,erythrocytes are plentiful and easily ***,erythrocytes are metabolically active,a feature that distinguishes this sample source from other bodily fluids like plasma and *** this preliminary pilot study,the erythrocyte metabolomes of 10 histopathologically confirmed AD patients and 10 patients without AD(control(CTRL))were *** blood was collected post-mortem and erythrocytes were analyzed using ultraperformance liquid chromatography tandem mass *** 750 metabolites were identified in AD and CTRL *** were increased in AD while 24 were decreased(Pity of the metabolites increased in AD were associated with amino acid metabolism and all of the decreased metabolites were associated with lipid *** among the potential biomarkers were 10 sphingolipid or sphingolipid-related species that were consistently decreased in AD *** have been previously implicated in AD and other neurological ***,previous studies have shown that erythrocyte sphingolipid concentrations vary widely in normal,healthy ***,these observations suggest that certain erythrocyte lipid phenotypes could be markers of risk for development of AD.

关键词： Alzheimer’s disease Neurodegenerative disease Mass spectrometry Erythrocytes Biomarkers Metabolomics

Revisiting cerebral endothelial cells in Alzheimer’s disease

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Neural Regeneration Research 2025年第10期20卷 2911-2912页

作者： Amira s.Hanafy Department of Neurosurgery University Hospital BonnBonnGermany

Alzheimer’s disease(AD)is the most common neurodegenerative disorder characterized by slow and progressive decline of cognitive and memory *** only approximately 5%of the cases,AD is familial,as often predisposed by genetic mutations(Hoogmartens et al.,2021),while sporadic AD accounts for approximately 95%of the *** amyloid cascade hypothesis is one of the fundamental hypotheses put out to explain AD pathogenesis as dysregulated homeostasis of amyloid-β(Aβ)peptides that leads to the accumulation of Aβplaques in the parenchyma,an anatomical hallmark of AD.

关键词： Alzheimer Aβ cerebral

Emerging structures and dynamic mechanisms ofγ-secretase for Alzheimer’s disease

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Neural Regeneration Research 2025年第1期20卷 174-180页

作者： Yinglong Miao Michael s.Wolfe Computational Medicine Program and Department of Pharmacology University of North Carolina–Chapel HillChapel HillNCUSA Department of Medicinal Chemistry University of KansasLawrenceKSUSA

γ-secretase,called“the proteasome of the membrane,”is a membrane-embedded protease complex that cleaves 150+peptide substrates with central roles in biology and medicine,including amyloid precursor protein and the Notch family of cell-surface *** inγ-secretase and amyloid precursor protein lead to early-onset familial Alzheimer’s disease.γ-secretase has thus served as a critical drug target for treating familial Alzheimer’s disease and the more common late-onset Alzheimer’s disease as ***,critical gaps remain in understanding the mechanisms of processive proteolysis of substrates,the effects of familial Alzheimer’s disease mutations,and allosteric modulation of substrate cleavage byγ-*** this review,we focus on recent studies of structural dynamic mechanisms ofγ-*** mechanisms,including the“Fit-stay-Trim,”“sliding-Unwinding,”and“Tilting-Unwinding,”have been proposed for substrate proteolysis of amyloid precursor protein byγ-secretase based on all-atom molecular dynamics *** an incorrect registry of the Notch1 substrate was identified in the cryo-electron microscopy structure of Notch1-boundγ-secretase,molecular dynamics simulations on a resolved model of Notch1-boundγ-secretase that was reconstructed using the amyloid precursor protein-boundγ-secretase as a template successfully capturedγ-secretase activation for proper cleavages of both wildtype and mutant Notch,being consistent with biochemical experimental *** approach could be potentially applied to decipher the processing mechanisms of various substrates byγ-*** addition,controversy over the effects of familial Alzheimer’s disease mutations,particularly the issue of whether they stabilize or destabilizeγ-secretase-substrate complexes,is ***,an outlook is provided for future studies ofγ-secretase,including pathways of substrate binding and product release,effects of modulators on familial Alzheimer’s disease mutations

关键词： Alzheimer’s disease amyloid precursor protein cryo-EM structures drug design intramembrane proteolysis molecular dynamics Notch

Complementary roles of glial cells in generating region-specific neuroinflammatory responses and phagocytosis in Parkinson’s disease

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Neural Regeneration Research 2025年第10期20卷 2917-2918页

作者： Leyre Ayerra Maria s.Aymerich Universidad de Navarra Facultad de CienciasDepartamento de Bioquímica y GenéticaPamplonaSpain CiMA-Universidad de Navarra PamplonaSpain idisNA Instituto de Investigación Sanitaria de NavarraPamplonaSpain

Neuroinflammation is associated with Parkinson’s disease:Reactive gliosis and neuroinflammation are hallmarks of Parkinson’s disease(PD),a multisystem neurodegenerative disorder characterized by a progressive loss of dopaminergic *** has long been considered a mere consequence of neuronal loss,but whether it promotes PD or is a key player in disease progression remains to be *** leukocyte antigen.

关键词： inflammation leukocyte generating

Multisensory mechanisms of gait and balance in Parkinson’s disease:an integrative review

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Neural Regeneration Research 2025年第1期20卷 82-92页

作者： stiven Roytman Rebecca Paalanen Giulia Carli Uros Marusic Prabesh Kanel Teus van Laar Nico i.Bohnen Department of Radiology University of MichiganAnn ArborMIUSA Department of Neurology University of MichiganAnn ArborMIUSA Morris K.Udall Center of Excellence for Parkinson’s Disease Research University of MichiganAnn ArborMIUSA institute for Kinesiology Research Science and Research Centre KoperKoperSlovenia Department of Health sciences Alma Mater Europaea–ECMMariborSlovenia Parkinson’s Foundation Research Center of Excellence University of MichiganAnn ArborMIUSA Department of Neurology University of GroningenUniversity Medical Center GroningenGroningenThe Netherlands Neurology service and GRECC VA Ann Arbor Healthcare SystemAnn ArborMIUSA

Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have on our aging *** and gait control does not happen automatically,as previously believed,but rather requires continuous involvement of central nervous *** effectively exert control over the body,the brain must integrate multiple streams of sensory information,including visual,vestibular,and somatosensory *** mechanisms which underpin the integration of these multisensory signals are the principal topic of the present *** multisensory integration theories focus on how failure of cognitive processes thought to be involved in multisensory integration leads to falls in older *** emphasis,however,has been placed on specific contributions of individual sensory modalities to multisensory integration processes and cross-modal interactions that occur between the sensory modalities in relation to gait and *** the present work,we review the contributions of somatosensory,visual,and vestibular modalities,along with their multisensory intersections to gait and balance in older adults and patients with Parkinson’s *** also review evidence of vestibular contributions to multisensory temporal binding windows,previously shown to be highly pertinent to fall risk in older ***,we relate multisensory vestibular mechanisms to potential neural substrates,both at the level of neurobiology(concerning positron emission tomography imaging)and at the level of electrophysiology(concerning electroencephalography).We hope that this integrative review,drawing influence across multiple subdisciplines of neuroscience,paves the way for novel research directions and therapeutic neuromodulatory approaches,to improve the lives of older adults and patients with neurodegenerative diseases.

关键词： aging balance encephalography functional magnetic resonance imaging gait multisensory integration Parkinson’s disease positron emission tomography somatosensory vestibular visual

Effect of erosion on corrosion of APi X120 steel in relation to erodent particle size

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Journal of iron and steel Research international 2020年第6期27卷 691-701页

作者： Paul C.okonkwo said Grami srinivasan Murugan shariq Khan Mechanical and Mechatronics Engineering Department College of EngineeringDhofar University211 SalalahOman Chemical Engineering College of EngineeringDhofar University211 SalalahOman

The nature of the solid erodent particles present in corrosive petroleum fluid can cause transporting pipeline to experience severe erosion and corrosion damages. The effect of erosion on corrosion behavior of APi X120 steel was investigated using aluminum oxide and silicon carbide particles with different sizes as erodent and 3.5wt.% NaCl aqueous solution saturated with carbon dioxide as a corrosive medium. The effect of the erodent particle size on the corrosion behavior of the steel material at different particle speeds and impact angles was investigated using weight loss, potentiodynamic polarization and surface analysis techniques. The erosion results confirmed that the material damage increased with increasing particle speed. it was observed that in carbon dioxide-saturated saline solution, deposition of protective iron carbonate film occurred on the steel surface. it was found that the corrosion film can provide better protection at lower particle speed than at higher speed. The ratio of total erosion-corrosion (s)/effect of erosion on corrosion (T) analysis confirmed that at higher s/T ratio, the particle speed and material removal rate are low and vice versa at lower s/T ratio. Lower s/T values for the combined erosion and corrosion tests performed with erodent silicon carbide particle compared to erodent aluminum oxide particle showed that erosion enhancement of corrosion is more evident in the test performed using aluminum oxide particle than using silicon carbide particle. The result also suggests that when subjected to larger size erodent particle, the damage to pipeline due to effect of erosion on corrosion process can be more significant compared to smaller size erodent particle.

关键词： Erosion Corrosion APi X120 steel Carbon dioxide Aluminum oxide silicon carbide Erodent particlesize

Effects of cutting parameter on microstructure and corrosion behavior of 304 stainless steel in simulated primary water

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Journal of Materials science & Technology 2022年第27期122卷 219-230页

作者： Honglin Yan Jianqiu Wang Zhiming Zhang Bright O.okonkwo Key Laboratory of Nuclear Materials and safety Assessment Institute of Metal ResearchChinese Academy of Sciences school of Materials science and Engineering University of Science and Technology of China

The influence of surface conditions on the corrosion behavior of engineering structures has been paid more ***,there is still a lack of systematic research on the effect of cutting parameters on material’s microstructure and performance in *** this paper,the effect of cutting parameters on microstructure and corrosion behaviors of 304 stainless steel in simulated primary water is well *** results show that different cutting parameters can cause the superficial layer a gradient microstructure with nanocrystalized layer on top and deformation band structures *** the similar surface roughness,the deformation microstructure can be very different due to the different cutting *** effect degree on the depth of deformation zone is feed rate>cutting depth>cutting *** larger feed rate,lower cutting depth,lower cutting rate may induce a deeper deformation *** the increasing depth away from the machined surface,the localized corrosion rate is decreased,and at the same depth the localized corrosion rate along the deformation bands is higher than that along the grain boundaries(GBs).The nanocrystalized surface has a smallest general corrosion rate due to the quick formation of Cr rich oxide ***,once the corrosion penetrates through this nanocrystalized layer,subsequent preferential corrosion at deformation bands and GBs will dominate and may lead to the significant increase of corrosion rate of the component in high temperature pressurized water.

关键词： stainless steel Transmission electron microscopy(TEM) High temperature corrosion Cutting parameter

“Oil injustice” in Nigeria’s Niger Delta Region: A Call for Responsive Governance

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Journal of Environmental Protection 2017年第1期8卷 42-60页

作者： Theodore okonkwo Uzuazo Etemire Department of Public Law Faculty of Law University of Port Harcourt Port Harcourt Nigeria

The injustice and chaos in the Niger Delta region of Nigeria resulting from the manner in which the oil industry is being run and regulated have since captured the attention of the world. importantly, the 2011 UNEP Report on the Environmental Assessment of Ogoniland (a Niger Delta community) which revealed shocking levels of ecological degradation has helped to keep the issue on the front burners of international discussion. in this light, this article explores the nature of injustice in the oil producing areas of Nigeria;it assesses the regulatory mechanisms that have been set up to prevent and reverse the injustice in the region;and based on the inadequacies of the present system, it makes recommendations as to how the mechanisms might be better strengthened, and governance executed, all in a manner that is more responsive to the plight of the affected people.

关键词： Oil and Gas Petroleum injustice Environmental Degradation Environmental Protection Benefit sharing Niger Delta Nigeria

A systematic review of progenitor survival and maturation in Parkinsonian models

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Neural Regeneration Research 2025年第11期20卷 3172-3178页

作者： Giulia Comini Eilís Dowd Pharmacology&Therapeutics and Galway Neuroscience Center University of GalwayGalwayIreland

stem cell-based brain repair is a promising emergent therapy for Parkinson's disease based on years of foundational research using human fetal donors as a cell *** current therapeutic options for patients,this approach has the potential to provide longterm stem cell–derived reconstruction and restoration of the dopaminergic input to denervated regions of the brain allowing for restoration of certain functions to *** ultimate clinical success of stem cell–derived brain repair will depend on both the safety and efficacy of the approach and the latter is dependent on the ability of the transplanted cells to survive and differentiate into functional dopaminergic neurons in the Parkinsonian *** the pre-clinical literature suggests that there is considerable variability in survival and differentiation between studies,the aim of this systematic review was to assess these parameters in human stem cell-derived dopaminergic progenitor transplant studies in animal models of Parkinson's disease.A defined systematic search of the PubMed database was completed to identify relevant studies published up to March *** screening,76 articles were included in the analysis from which 178 separate transplant studies were *** these,graft survival could be assessed in 52 studies and differentiation in 129 ***,we found that graft survival ranged froms transplanted,with a median of 51%of transplanted cells surviving in the brain;while dopaminergic differentiation of the cells ranged from 0% to 46% of cells transplanted with a median of 3%.This systematic review suggests that there is considerable scope for improvement in the differentiation of stem cell-derived dopaminergic progenitors to maximize the therapeutic potential of this approach for patients.

关键词： cell replacement therapy differentiation embryonic stem cells graft induced pluripotent stem cells Parkinson's disease survival transplant