检索结果-南通市图书馆

Heterogeneity of mature oligodendrocytes in the central nervous system

Neural Regeneration Research 2025年第5期20卷 1336-1349页

作者： Chao Weng Adam M.R.Groh Moein Yaqubi Qiao-Ling Cui Jo Anne Stratton G.R.Wayne Moore Jack P.Antel Neuroimmunology Unit Montreal Neurological Institute-HospitalDepartment of Neurology and NeurosurgeryMcGill UniversityMontrealQCCanada Department of Neurology Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina

Mature oligodendrocytes form myelin sheaths that are crucial for the insulation of axons and efficient signal transmission in the central nervous *** evidence has challenged the classical view of the functionally static mature oligodendrocyte and revealed a gamut of dynamic functions such as the ability to modulate neuronal circuitry and provide metabolic support to *** the recognition of potential heterogeneity in mature oligodendrocyte function,a comprehensive summary of mature oligodendrocyte diversity is *** delve into early 20th-century studies by Robertson and Río-Hortega that laid the foundation for the modern identification of regional and morphological heterogeneity in mature ***,recent morphologic and functional studies call into question the long-assumed homogeneity of mature oligodendrocyte function through the identification of distinct subtypes with varying myelination ***,modern molecular investigations,employing techniques such as single cell/nucleus RNA sequencing,consistently unveil at least six mature oligodendrocyte subpopulations in the human central nervous system that are highly transcriptomically diverse and vary with central nervous system *** and disease related mature oligodendrocyte variation denotes the impact of pathological conditions such as multiple sclerosis,Alzheimer's disease,and psychiatric ***,caution is warranted when subclassifying mature oligodendrocytes because of the simplification needed to make conclusions about cell identity from temporally confined *** studies leveraging advanced techniques like spatial transcriptomics and single-cell proteomics promise a more nuanced understanding of mature oligodendrocyte *** research avenues that precisely evaluate mature oligodendrocyte heterogeneity with care to understand the mitigating influence of species,sex,central nervous system region,age,and disease,

关键词： aging central nervous system diseases electron microscopy heterogeneity immunohistochemistry myelin sheath natural history neuroglia oligodendroglia single-cell gene expression analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Co-adsorption of gaseous benzene, toluene, ethylbenzene,m-xylene(BTEX) and SO_2 on recyclable Fe_3O_4 nanoparticles at 0–101% relative humidities

引用

Journal of Environmental Sciences 2015年第5期27卷 164-174页

作者： Connie Z.Ye Parisa A.Ariya Department of Chemistry McGill University Department of Atmospheric and Oceanic Sciences McGill University

We herein used Fe3O4 nanoparticles（NPs） as an adsorption interface for the concurrent removal of gaseous benzene, toluene, ethylbenzene and m-xylene（BTEX） and sulfur dioxide（SO2）, at different relative humidities（RH）. X-ray diffraction, Brunauer-Emmett-Teller, and transmission electron microscopy were deployed for nanoparticle surface ***-dispersed Fe3O4（Fe2O3·Fe O） NPs synthesized with oleic acid（OA） as surfactant, and uncoated poly-dispersed Fe3O4 NPs demonstrated comparable removal *** experiments of BTEX on NPs were measured using gas chromatography equipped with flame ionization detection, which indicated high removal efficiencies（up to（95 ± 2）%） under dry conditions. The humidity effect and competitive adsorption were investigated using toluene as a model compound. It was observed that the removal efficiencies decreased as a function of the increase in RH, yet, under our experimental conditions, we observed（40 ± 4）% toluene removal at supersaturation for Fe3O4 NPs, and toluene removal of（83 ± 4）% to（59 ± 6）%, for OA-Fe3O4 NPs. In the presence of SO2, the toluene uptake was reduced under dry conditions to（89 ± 2）% and（75 ± 1）% for the uncoated and coated NPs, respectively, depicting competitive adsorption. At RH 〉 100%,competitive adsorption reduced the removal efficiency to（27 ± 1）% for uncoated NPs whereas OA-Fe3O4 NPs exhibited moderate efficiency loss of（55 ± 2）% at *** point to heterogeneous water coverage on the NP surface. The magnetic property of magnetite facilitated the recovery of both types of NPs, without the loss in efficiency when recycled and reused.

关键词： Fe3O4 nanoparticles Co-adsorption Competitive adsorption BTEX removal SO2 removal

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dynamic changes in the expression of apoptosis-related genes in differentiating gonocytes and in seminomas

引用

Asian Journal of Andrology 2015年第3期17卷 403-414页

作者： Gurpreet Manku The Research Institute of the mcgill university Health Centre McGill University Montreal Quebec Canada Departments of Medicine McGill University Montreal Quebec Canada Department of Pharmacology and Therapeutics McGill University Montreal Quebec Canada

Apoptosis is an integral part of the spermatogenic process, necessary to maintain a proper ratio of Sertoli to germ cell numbers and provide an adequate microenvironment to germ cells. Apoptosis may also represent a protective mechanism mediating the elimination of abnormal germ cells. Extensive apoptosis occurs between the first and second postnatal weeks, at the point when gonocytes, precursors of spermatogonial stem cells, should have migrated toward the basement membrane of the tubules and differentiated into spermatogonia. The mechanisms regulating this process are not well-understood. Gonocytes undergo phases of proliferation, migration, and differentiation which occur in a timely and closely regulated manner. Gonocytes failing to migrate and differentiate properly undergo apoptosis. Inadequate gonocyte differentiation has been suggested to lead to testicular germ cell tumor （TGCT） formation. Here, we examined the expression levels of apoptosis-related genes during gonocyte differentiation by quantitative real-time polymerase chain reaction, identifying 48 pro- and anti-apoptotic genes increased by at least two-fold in rat gonocytes induced to differentiate by retinoic acid, when compared to untreated gonocytes. Further analysis of the most highly expressed genes identified the pro-apoptotic genes Gadd45a and Cycs as upregulated in differentiating gonocytes and in spermatogonia compared with gonocytes. These genes were also significantly downregulated in seminomas, the most common type of TGCT, compared with normal human testicular tissues. These results indicate that apoptosis-related genes are actively regulated during gonocyte differentiation. Moreover, the down-regulation of pro-apoptotic genes in seminomas suggests that they could represent new therapeutic targets in the treatment of TGCTs.

关键词： apoptosis differentiation gonocytes seminomas spermatogonia

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Statistical Analyses of Runoff,River Stage and Peak Discharge,Tao River,China

引用

高原气象 1989年第1期8卷 52-63页

作者： C.A.Madramootoo,G.L.Austin,M.Blaskovic mcgill university mcgill university mcgill university Canada Canada Canada

Empirical equations relating runoff,maximum river stageand peak flow to rainfall were developed for the Tao riverdrainage basin at Li Jia Cun.A basin recession curve wasderived and a frequency analysis of extreme flood events *** showed that storm runoff was highlycorrelated with ***,maximum river stage andpeak flow were not as well correlated with *** wasfound necessary to separate rainfall into stratiform andconvective *** magnitudes of the once-in-50 year,once-in-100 year and once-in-200 year events,calculated by thelog Pearson type Ⅲ distribution were closely equal to thoseestimated from a log-probability *** forimproving the predictive ability of the empirical equations arepresented.

关键词： Figure

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Methane Dynamics in Northern Peatlands: A Review

引用

Pedosphere 2009年第4期19卷 409-421页

作者： D. Y. F. LAI Department of Geography McGill University

Northern peatlands store a large amount of carbon and play a significant role in the global carbon cycle. Owing to the presence of waterlogged and anaerobic conditions, peatlands are typically a source of methane (CH4), a very potent greenhouse gas. This paper reviews the key mechanisms of peatland CH4 production, consumption and transport and the major environmental and biotic controls on peatland CH4 emissions. The advantages and disadvantages of micrometeorological and chamber methods in measuring CH4 fluxes from northern peatlands are also discussed. The magnitude of CH4 flux varies considerably among peatland types (bogs and fens) and microtopographic locations (hummocks and hollows). Some anthropogenic activities including forestry, peat harvesting and industrial emission of sulphur dioxide can cause a reduction in CH4 release from northern peatlands. Further research should be conducted to investigate the in fluence of plant growth forms on CH4 flux from northern peatlands, determine the water table threshold at which plant production in peatlands enhances CH4 release, and quantify peatland CH4 exchange at plant community level with a higher temporal resolution using automatic chambers.

关键词： global carbon cycle greenhouse gas methane oxidation methanogenesis methanotrophy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

New approaches to cognitive work analysis through latent variable modeling in mining operations

引用

International Journal of Mining Science and Technology 2019年第4期29卷 549-556页

作者： S.Li Y.A.Sari M.Kumral Department of Mining and Materials Engineering McGill University

This paper discusses the utilization of latent variable modeling related to occupational health and safety in the mining *** variable modeling,which is a statistical model that relates observable and latent variables,could be used to facilitate researchers’understandings of the underlying constructs or hypothetical factors and their magnitude of effect that constitute a complex *** enhanced understanding,in turn,can help emphasize the important factors to improve mine *** most commonly used techniques include the exploratory factor analysis(EFA),the confirmatory factor analysis(CFA)and the structural equation model with latent variables(SEM).A critical comparison of the three techniques regarding mine safety is *** applications of latent variable modeling in mining engineering are *** this scope,relevant research papers were *** suggest that the application of such methods could prove useful in mine accident and safety *** of latent variables analysis in cognitive work analysis was proposed to improve the understanding of human-work relationships in mining operations.

关键词： Latent variables Exploratory factor analysis Confirmatory factor analysis Structural equation modeling Occupational health and safety Mine safety

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Phase-controlled field-effect micromixing using AC electroosmosis

引用

Microsystems & Nanoengineering 2020年第1期6卷 672-682页

作者： Paresa Modarres Maryam Tabrizian Biomedical Engineering Department McGill UniversityMontrealQCCanada Faculty of Dentistry McGill University2001 McGill College AveMontrealQCCanada

The exploration and application of electrokinetic techniques in micro total analysis systems have become ubiquitous in recent years,and scientists are expanding the use of such techniques in areas where comparable active or passive methods are not as *** this work,for the first time,we utilize the concept of AC electroosmosis to design a phase-controlled field-effect micromixer that benefits from a three-finger sinusoidally shaped *** to field-effect transistor devices,the principle of operation for the proposed micromixer is governed by the source-gate and source-drain voltage potentials that are modulated by introducing a phase lag between the driving *** an optimized flow rate and biasing scheme,we demonstrate that the source,gate,and drain voltage phase relations can be configured such that the micromixer switches from an unmixed state(phase shift of 0°)to a mixed state(phase shift of 180°).High mixing efficiencies beyond 90%was achieved at a volumetric flow rate of 4µL/min corresponding to~13.9mm/s at optimized voltage excitation ***,we employed the proposed micromixer for the synthesis of nanoscale lipid-based drug delivery vesicles through the process of electrohydrodynamic-mediated *** phase-controlled electrohydrodynamic mixing utilized for the nanoprecipitation technique proved that nanoparticles of improved monodispersity and concentration can be produced when mixing efficiency is enhanced by tuning the phase shifts between electrodes.

关键词： effect mixing mixer

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Freezing on demand: A new concept for mine safety and energy savings in wet underground mines

引用

International Journal of Mining Science and Technology 2019年第4期29卷 621-627页

作者： Mahmoud A.Alzoubi Ahmad Zueter Aurelien Nie-Rouquette Agus P.Sasmito Department of Mining and Materials Engineering McGill University

The artificial ground freezing(AGF)systems are designed to operate continuously for an extended period of time to control the groundwater seepage and to strengthen the groundwater structure surrounding excavation *** mode of operation requires a massive amount of energy to sustain the thickness of the frozen ***,it is of great interest to propose new concepts to reduce energy consumption while providing sufficient structural stability and safe *** paper discusses the principle of the freezing on demand(FoD)by means of experiment and mathematical model.A lab-scale rig that mimics the AGF process is conceived and *** setup is equipped with more than 80 thermocouples,flow-meters,and advanced instrumentation system to analyze the performance of the AGF process under the FoD concept.A mathematical model has been derived,validated,and utilized to simulate the transient FoD *** results suggest that the overall energy saving notably depends on the coolant’s temperature;the energy saving increases while decreasing the coolant inlet ***,applying the FoD concept in an AGF system leads to a significant drop in energy consumption.

关键词： Artificial ground freezing Freezing on demand Energy saving Conjugate heat transfer Porous media

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Physicochemical aspects of allanite flotation

引用

Journal of Rare Earths 2014年第5期32卷 476-486页

作者： Adam Jordens Chris Marion Olga Kuzmina Kristian E.Waters Department of Mining and Materials Engineering McGill University

This paper investigated the physicochemical properties of allanite, a RE-silicate, by measuring zeta potential in the absence and presence of three different flotation collectors （benzohydroxamic acid, sodium oleate and dodecylamine）. This data was then verified by microflotation experiments and with bubble-particle attachment pictures. The investigated properties of allanite were com- pared to those of quartz, a common gangue mineral in many RE deposits. The results of this work indicated that only dodecylamine was able to achieve a selective separation of allanite and quartz. This was accomplished by lowering the dodecylamine dosage so that only quartz was recovered by microflotation.

关键词： allanite flotation surface chemistry zeta potential bubble-particle attachment rare earths

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Probabilistic approach for open pit bench slope stability analysis——A mine case study

引用

International Journal of Mining Science and Technology 2019年第4期29卷 629-640页

作者： Christian Obregon Hani Mitri Department of Mining and Materials Engineering McGill University

The geotechnical slope design of an open pit wall starts at the bench scale *** this scale,the rock slope stability is governed primarily by the geological discontinuities within the rock mass and as a result,structurally-controlled failures(***,wedge or toppling)are most likely to *** probabilistic approach offers a major advantage over the traditional deterministic method in that it accounts for the different degrees of variability and uncertainty often encountered in rock *** paper presents a bench slope stability assessment for an open pit mine in Peru using a probabilistic-based approach by coupling a kinematic analysis based on stereographic projection techniques followed by a kinetic analysis by means of the limit equilibrium ***,these two probabilities are combined to provide an overall measure of the probability of failure(PoF)of the bench slope *** case study is characterized by significant scatter in the geometrical and mechanical properties of the *** surface mapping was conducted at 36 different sites following the ISRM suggested *** direct shear tests were carried *** is shown that by combining field and laboratory measurements and engineering judgment,the probability density functions(PDF)of the discontinuity parameters can be *** are then used in a Monte Carlo simulation process to compute both kinematic and kinetic probabilities of *** overall probability of failure aims to provide the design engineer with a tool to critically evaluate the bench performance from a geotechnical risk perspective and to provide a basis for future bench design optimization.

关键词： Mine safety Rock slope stability Kinematic analysis Probability of failure Limit equilibrium analysis Case study

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：