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Propofol enhances the field excitatory postsynaptic potentials in CA1 hippocampal slices of young and aged mice

Chinese Medical Journal 2014年第1期127卷 137-141页

作者： Yin Yiqing William J Middleton Carlos M. Florez Peter L. Carlen Hossam EI-Beheiry Department of Anesthesia Peking University China-Japan Friendship Hospital Beijing 100029 China Department of Anesthesia Toronto Westem Hospital University ofToronto University Health Network Toronto Canada toronto Western Research Institute University of Toronto TorontoCanada Department of Anesthesia Trillium Health Centre MississaugaOntario Canada

Background Increasing age was shown to decrease the requirements for ***,the mechanisms of ageing-induced potentiation of anesthetic actions have not been clearly *** aim of this study is to compare the effects of propofol on the field excitatory postsynaptic potentials （fEPSPs） in hippocampal slices of young and aging *** Brain slices were prepared from C57BL6 male young （2 months） and aging （＞12 months） *** dendritic field excitatory postsynaptic potential was recorded from the CA1 stratum radiatum using patch clamp electrophysiological methods.A bipolar concentric stimulating electrode was placed along the Schaffer collateral for othodromic *** effects of clinically-relevant concentrations of propofol were studied in the young and ageing mouse *** Propofol application increased the orthodromically evoked fEPSP produced in slices taken from young and older animals.A striking feature in the I/O relationship was the decreased enhancement of the fEPSPs by propofol in slices from older mice.A clinically relevant concentration of propofol,10 μmol/L,showed more significant enhancement in amplitude and area under the curve （AUC） of fEPSP in young compared to tissues from older mice （amplitude：young （24.9±3.4）％,old （4.6±1.6）％; AUC young （30.6±5.4）％,old （2.1±1.7）％）.There was no statistically significant difference between the paired-pulse facilitation （PPF） ratios calculated for the responses obtained in tissues from young *** slices from older mice,in the presence of 10 μmol/L propofol,PPF was decreased and returned to baseline after washout （baseline 1.21±0.01,propofol：1.16±0.01）.Bicuculline （15 μmol/L） blocked the enhancement of propofol on fEPSP in tissues from young and old *** The fEPSP of slices from aging mice demonstrates diminished sensitivity to the enhancing actions of propofol.

关键词： propofol field excitatory postsynaptic potentials CA1 hippocampal slice aging patch clamp

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Structure and principles of self-assembly of giant“sea urchin”type sulfonatophenyl porphine aggregates

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Nano Research 2022年第6期15卷 5527-5537页

作者： Marijus Pleckaitis Fayez Habach Lukas Kontenis Gábor Steinbach Greta Jarockyte Agne Kalnaityte IldikóDomonkos Parveen Akhtar Mehdi Alizadeh Saulius Bagdonas Vitalijus Karabanovas GyőzőGarab Ricardas Rotomskis Virginijus Barzda Laser Research Center Faculty of PhysicsVilnius UniversitySauletekio av.10Vilnius LT-10223Lithuania Biomedical Physics Laboratory National Cancer InstituteP.Baublio str.3bVilnius LT-08406Lithuania Department of Chemical and Physical Sciences University of Toronto Mississauga3359 Mississauga RdMississauga L5L 1C6Canada Light Conversion Keramiku str.2BVilnius LT-10233Lithuania Cellular Imaging Laboratory Biological Research CentreEötvös Loránd Research NetworkTemesvári körút 62Szeged 6726Hungary Institute of Biophysics Biological Research CentreEötvös Loránd Research NetworkTemesvári körút 62Szeged 6726Hungary Biofotonika Research and Development Ltd. Dózsa u.7Szeged 6720Hungary Institute of Plant Biology Biological Research CentreEötvös Loránd Research NetworkTemesvári körút 62Szeged 6726Hungary Department of Chemistry and Bioengineering Vilnius Gediminas Technical UniversitySauletekio av.11Vilnius LT-10223Lithuania Department of Physics Faculty of ScienceUniversity of OstravaChittussiho 10Ostrava CZ-71000Czech Republic Department of Physics University of Toronto60 St.George St.TorontoToronto M5S 1A7Canada

Principles of molecular self-assembly into giant hierarchical structures of hundreds of micrometers in size are studied in aggregates of meso-tetra(4-sulfonatophenyl)porphine(TPPS_(4)).The aggregates form a central tubular core,which is covered with radially protruding filamentous non-branching *** filaments cluster and orient at varying angles from the core surface and some filaments form *** to shape resemblance,the structures are termed giant sea urchin(GSU)*** resolved fluorescence microscopy reveals J-and H-bands of TPPS_(4)aggregates in both the central core and the *** fluorescence of the core is quenched while filaments exhibit strong *** drying,the filament fluorescence gets quenched while the core is less affected,showing stronger relative *** linear dichroism(FDLD)microscopy reveals that absorption dipoles corresponding to J-bands are oriented along the filament *** comparison of FDLD with scanning electron microscopy(SEM)reveals the structure of central core comprised of multilayer ribbons,which wind around the core axis forming a *** second-harmonic generation(SHG)and thirdharmonic generation microscopy exhibits strong signal from the filaments with nonlinear dipoles oriented close to the filament axis,while central core displays very low SHG due to close to centrosymmetric *** chiral nonlinear susceptibility points to helical arrangement of the *** investigation shows that TPPS_(4)molecules form distinct aggregate types,including chiral nanotubes and nanogranular aggregates that associate into the hierarchical GSU structure,prototypical to complex biological *** chiral TPPS_(4)aggregates can serve as harmonophores for nonlinear microscopy.

关键词： meso-tetra(4-sulfonatophenyl)porphine(TPPS_(4))aggregates self-assembly nanostructures harmonophores polarimetric second harmonic generation microscopy third harmonic generation microscopy

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Variations in terrestrial oxygen sources under climate change

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Science China Earth Sciences 2022年第9期65卷 1810-1823页

作者： Lei DING Jianping HUANG Changyu LI Dongliang HAN Xiaoyue LIU Haiyun LI Yan BAI Jiping HUANG College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China Collaborative Innovation Center for Western Ecological Safety Lanzhou UniversityLanzhou 730000China Enlightening Bioscience Research Center Mississauga L4X 2X7Canada

The terrestrial ecosystem is an important source of atmospheric oxygen, and its changes are closely related to variations in atmospheric oxygen level. However, few studies have focused on the characteristics and driving forces behind terrestrial ecosystem oxygen sources. In this study, based on observations and net carbon flux simulations from the Sixth Coupled Model Intercomparison Project, we investigated temporal and spatial variations in terrestrial oxygen sources. As the largest source of atmospheric oxygen, the terrestrial ecosystem can produce approximately 7.10±0.38 gigatons of oxygen per year, and the tropics are the main oxygen producing regions. Notably, there are many “non-oxygen-producing lands”, where the lands no longer provide oxygen to the atmosphere, located in the high latitudes and around the deserts of Central Asia. Long-term analysis reveals that anthropogenic activities and climate change are responsible for the variations in terrestrial oxygen sources owing to land-use changes and competing effects between net photosynthesis and heterotrophic respiration. By 2100, more oxygen will be produced from the low-middle latitudes, while the high latitudes will serve as a larger oxygen sink due to extreme land-use type changes and drastic increases in soil respiration. Through this study, we supplement the understanding of the modern oxygen cycle and help provide better estimates for future variations in atmospheric oxygen level.

关键词： Oxygen cycle Terrestrial ecosystem CMIP6 Anthropogenic forcing Climate change

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Effect of the Instrument Slit Function on Upwelling Radiance from a Wavelength Dependent Surface Reflectance

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Natural Science 2022年第3期14卷 133-147页

作者： Rajinder K. Jagpal Rehan Siddiqui Sanjar M. Abrarov Brendan M. Quine Epic College of Technology Mississauga Canada Department of Physics and Astronomy York University Toronto Canada Department of Earth and Space Science and Engineering York University Toronto Canada Thoth Technology Inc. Algonquin Radio Observatory Pembroke Canada

The Radiance Enhancement (RE) method was introduced for efficient detection of clouds from the space. Recently, we have also reported that due to high reflectance of combustion-originated smokes, this approach can also be generalized for detection of the forest fires by retrieving and analyzing datasets collected from a space orbiting micro-spectrometer operating in the near infrared spectral range. In our previous publication, we have performed a comparison of observed and synthetic radiance spectra by developing a method for computation of surface reflectance consisting of different canopies by weighted sum based on their areal coverage. However, this approach should be justified by a method based on corresponding proportions of the upwelling radiance. The results of computations we performed in this study reveal a good match between areal coverage of canopies and the corresponding proportions of the upwelling radiance due to effect of the instrument slit function.

关键词： Radiance Enhancement Upwelling Radiance Line-by-Line Computation Radiative Transfer Model

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The Variability of Air-sea O_(2)Flux in CMIP6:Implications for Estimating Terrestrial and Oceanic Carbon Sinks

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Advances in Atmospheric Sciences 2022年第8期39卷 1271-1284,I0024-I0026页

作者： Changyu LI Jianping HUANG Lei DING Yu REN Linli AN Xiaoyue LIU Jiping HUANG College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China Collaborative Innovation Center for Western Ecological Safety Lanzhou UniversityLanzhou 730000China Enlightening Bioscience Research Center MississaugaL4X 2X7Canada

The measurement of atmospheric O_(2)concentrations and related oxygen budget have been used to estimate terrestrial and oceanic carbon ***,a discrepancy remains in assessments of O_(2)exchange between ocean and atmosphere(***-sea O_(2)flux),which is one of the major contributors to uncertainties in the O_(2)-based estimations of the carbon ***,we explore the variability of air-sea O_(2)flux with the use of outputs from Coupled Model Intercomparison Project phase 6(CMIP6).The simulated air-sea O_(2)flux exhibits an obvious warming-induced upward trend(~1.49 Tmol yr−2)since the mid-1980s,accompanied by a strong decadal variability dominated by oceanic climate *** subsequently revise the O_(2)-based carbon uptakes in response to this changing air-sea O_(2)*** results show that,for the 1990−2000 period,the averaged net ocean and land sinks are 2.10±0.43 and 1.14±0.52 GtC yr−1 respectively,overall consistent with estimates derived by the Global Carbon Project(GCP).An enhanced carbon uptake is found in both land and ocean after year 2000,reflecting the modification of carbon cycle under human *** derived from CMIP5 simulations also investigated in the study allow for comparisons from which we can see the vital importance of oxygen dataset on carbon uptake estimations.

关键词： air-sea O_(2)flux carbon budget land and ocean carbon sinks CMIP6

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Modified Experimental Equipment to Prepare Dithietenes from Bis-（polyfluoroalkyl）-acetylenes and Sulfur

Modified Experimental Equipment to Prepare Dithietenes from ...

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2015年第十四届全国应用化学年会

作者：汪晓平 Ulrich W. Fekl university of toronto at mississauga

＜正＞Metal dithiolene complexes are a group of important compounds in some biological *** intermediates to prepare the metal dithiolene complexes are usually dithietenes.

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NanoHDA： A nanoparticle-assisted isothermal amplification technique for genotyping assays

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Nano Research 2017年第1期10卷 12-21页

作者： Abootaleb Sedighi Christopher Oberc Vicki Whitehall Paul C. H. Li Department of Chemistry Simon Fraser University Burnaby British Columbia VSA 1S6 Canada QIMR Berghofer Medical Research Institute 300 Herston Rd Brisbane Queensland 4006 Australia Department of Chemical and Physical Sciences University of Toronto Mississauga Ontario LSL IC6 Canada

Isothermal methods, such as helicase-dependent amplification （HDA）, have an advantage over polymerase chain reaction for DNA amplification owing to their ease of operation. Here, we developed a new HDA method that is nanoparticle-assisted, termed nanoHDA. This method uses gold nanoparticles （AuNPs） to improve the sensitivity and specificity of the isothermal method. In HDA, the denaturation of DNA templates is mediated by helicases, but this method is limited by the low denaturation efficiency of helicases. In this report, AuNPs with preferential affinity for single-stranded DNA （ssDNA） were utilized to improve the denaturation efficiency of helicases. The same affinity property of nanoparticles can also enhance specificity by suppressing primer-dimer formation. This nanoHDA method was employed to genotype the KRAS gene in genomic DNA samples from colorectal cancer patients, as achieved by the hybridization of nanoHDA amplicons using the NanoBioArray chip.

关键词： gold nanoparticle isothermal DNAamplification helicase genotyping assay colorectal cancer single nucleotidepolymorphism KRAS

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Deformation‑Induced Strengthening Mechanism in a Newly Designed L‑40 Tool Steel Manufactured by Laser Powder Bed Fusion

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Acta Metallurgica Sinica(English Letters) 2023年第1期36卷 21-34页

作者： Yuan Tian Kanwal Chadha Clodualdo Aranas Jr Voestalpine Additive Manufacturing Centre Ltd MississaugaON L5N 7Y3Canada Department of Mechanical Engineering University of New BrunswickFrederictonNB E3B 5A3Canada Planetary and Space Science Centre University of New BrunswickFrederictonNB E3B 5A3Canada

The microstructural and mechanical properties of a newly designed tool steel(L-40),specifcally designed to be employed in the laser powder bed fusion(LPBF)technique,were *** pool boundaries with submicron dendritic structures and about 14%retained austenite phase were evident after *** grain orientation after high cooling rate solidifcation is mostlyα∥building direction(BD).Then,the heat treatment converted the microstructure into a conventional martensitic phase,reduced the retained austenite to about 1.5%,and increasedα∥BD *** heat-treated sample exhibits higher tensile strength(1720±14 MPa)compared to the as-printed sample(1540±26 MPa)along the building direction,mainly due to hardening caused by a lower volume fraction of retained austenite phase and precipitation of *** a consequence of the strength-to-ductility trade-of,the heat-treated sample showed lower elongation(10%±2%)than that of the as-printed sample(18%±2%).It was observed that transformation-induced plasticity(TRIP)occurs in both the as-printed and heat-treated samples during tensile testing,which dynamically transforms the retained austenite into martensite,leading to improved *** minimum driving force to initiate the displacive phase transformation is about 6000 J/mol,which was achieved during tensile *** strength and ductility of LPBF-produced L-40 were compared with the other LPBF-produced tool steels in literature;the data indicate that heat-treated L-40 has an excellent combination of strength and ductility complemented with high printability.

关键词： Additive manufacturing Laser powder bed fusion L-40 tool steel Phase transformation

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Precipitation Behaviour at the Interface of an Additively Manufactured M789-N709 Hybrid Alloy

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金属学报:英文版 2023年第8期36卷 1353-1370页

作者： Kudakwashe Nyamuchiwa Yuan Tian Kanwal Chadha Lu Jiang Thomas Dorin Clodualdo Aranas Jr Mechanical Engineering Department University of New BrunswickFrederictonNBE3B 5A3Canada voestalpine Additive Manufacturing Centre Ltd. MississaugaONL5N 7Y3Canada Planetary and Space Science Centre University of New BrunswickFrederictonNBE3B 5A3Canada Institute for Frontier Materials Deakin UniversityGeelongVIC3220Australia

A novel hybrid alloy, designed for plastic injection dies, was fabricated by depositing M789 steel on wrought N709 steel through laser powder bed fusion (LPBF). The M789-N709 interface (with a thickness of about 300 μm) is characterized by the variation of titanium content from 0 wt% in the N709 section to about 1 wt% near the M789 region. A thermodynamic and kinetic simulation after aging treatment was performed to reveal the precipitation behavior in the M789-N709 interface. Different sizes and amounts of ETA-Ni3(Ti,Al) strengthening precipitates exist, with a maximum volume fraction and radius of about 5% and 5 nm, respectively (near the M789 region). Moreover, the volume fraction of precipitates significantly increases with Ti additions of up to 0.6 wt% (i.e., 100 μm from the N709 region);however, beyond this threshold, the increase in the amount of precipitation becomes gradual. The thermodynamic and kinetic simulations performed in the interface are validated by electron diffraction spectroscopy (EDS), electron probe microanalyzer (EPMA) and atomic probe tomography (APT) results;the measured precipitate size from the APT analysis is consistent with the simulation results. Two morphologies of precipitates were detected: elongated and spherical;both contribute to the robustness of the interface. The robust M789-N709 interface formed during the process shows good compatibility between the alloys, which is critical for extended tool life. These new insights about the precipitation at the interface of M789-N709 alloy are crucial in assessing the feasibility of N709 as a cost-effective base material to minimize the use of M789 when printing plastic injection dies.

关键词： Interface Direct aging Laser powder bed fusion Diffusion M789

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First Record of Soft-shelled Turtle(Testudines, Trionychidae) from the Late Pleistocene of Heilongjiang, Northeast China

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Acta Geologica Sinica(English Edition) 2021年第4期95卷 1409-1410页

作者： WU Wenhao DONG Nan LI Xiaobo ZHOU Changfu FENG Nan Robert R.REISZ Research Center of Palaeontology&Stratigraphy College of Earth ScienceJilin UniversityChangchun 130026China College of Earth Science Jilin UniversityChangchun 130061China Dinosaur Evolution Research Centre College of Earth ScienceJilin UniversityChangchun 130061China College of Earth Science and Engineering Shandong University of Science and TechnologyQingdaoShandong 266590China Heilongjiang Institute of Geological Sciences Harbin 150080China Department of Biology University of Toronto MississaugaMississaugaON L5L 1C6Canada

Objective Numerous vertebrate fossils, dominated by the Mammuthus–Coelodonta fauna, have been found from many Late Pleistocene fossil sites in Heilongjiang,northeast China(Jin and Kawamura, 1996). However,fossil turtles have not yet been reported. Recently, two soft-shelled turtle(trionychid) costal plates have been discovered together with other typical Mammuthus–Coelodonta fauna fossils.

关键词： Pleistocene Northeast northeast

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