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Single-molecule DNA sequencing using two-dimensionalTi2C(Oh)2 MXene nanopores: A first-principles investigation

Nano Research 2022年第11期15卷 9843-9849页

作者： Jariyanee Prasongkit Sirichok Jungthawan Rodrigo G.Amorim ralph h.scheicher Division of Physics Faculty of ScienceNakhon Phanom UniversityNakhon Phanom 48000Thailand School of Physics Institute of ScienceSuranaree University of Technology111 University AveNakhon Ratchasima 30000Thailand Center of Excellence in Advanced Functional Materials Suranaree University of TechnologyNakhon Ratchasima 30000Thailand Thailand Center of Excellence in Physics Ministry of Higher EducationScienceResearch and Innovation328 Si Ayutthaya RoadBangkok 10400Thailand Departamento de Física ICExUniversidade Federal Fluminense-UFFVolta Redonda/RJ 27213-145Brazil Division of Materials Theory Department of Physics and AstronomyUppsala UniversityUppsala SE-75120Sweden

Nanopore-based devices have provided exciting opportunities to develop affordable label-free DNA sequencing *** a decade ago,graphene has been proposed as a two-dimensional(2D)nanopore membrane in order to achieve single-base ***,it was experimentally revealed that clogging of the graphene nanopore can occur due to the hydrophobic nature of graphene,thus hindering the translocation of *** overcome this problem,the exploration of alternative 2D materials has gained considerable interest over the last *** we show that a Ti_(2)C-based MXene nanopore functionalized by hydroxyl groups(–Oh)exhibits transverse conductance properties that allow for the distinction between all four naturally occurring DNA *** have used a combination of density functional theory and non-equilibrium Green’s function method to sample over multiple orientations of the nucleotides in the nanopore,as generated from molecular dynamics *** conductance variation resulting from sweeping an applied gate voltage demonstrates that the Ti_(2)C-based MXene nanopore possesses high potential to rapidly and reliably sequence *** findings open the door to further theoretical and experimental explorations of MXene nanopores as a promising 2D material for nanopore-based DNA sensing.

关键词： nanopore DNA sequencing MXenes first-principles quantum transport

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Low-temperature catalytic methane deep oxidation over sol-gel derived mesoporous hausmannite (Mn_(3)O_(4)) spherical particles

ChemPhysMater

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ChemPhysMater 2024年第3期3卷 329-340页

作者： Patrick Ndouka Ndouka Stephane Kenmoe Jacques Richard Mache Elie Acayanka Dick hartmann Douma ralph Gebauer Patrick Mountapmbeme Kouotou Department of Chemistry Faculty of SciencesUniversity of MarouaP.O.Box 814 MarouaCameroon Department of Theoretical Chemistry University of Duisburg-EssenD-45141 EssenGermany Department of Mining Engineering School of Geology and Mining EngineeringUniversity of NgaoundéréP.O.Box 115 MeigangaCameroon Department of Inorganic Chemistry Faculty of ScienceUniversity of YaoundéIP.O.Box 812 YaoundéCameroon Groupe de Simulations Numériques en Magnétisme et Catalyse Facultédes Sciences et TechniquesUniversitéMarien NgouabiB.P.69 BrazzavilleCongo The Abdus Salam International Centre for Theoretical Physics(ICTP) 34151 TriesteItaly National Advanced School of Engineering of Maroua University of MarouaP.O.Box 46 MarouaCameroon higher Institute of Agriculture WoodWater and EnvironmentUniversity of EbolowaP.O.Box 118 EbolowaCameroon

In this study,Mn_(3)O_(4) spherical particles(SPs)were synthesized by the sol-gel process,after which they were thermally annealed at 400℃,and comprehensively characterized.X-ray Diffraction(XRD)revealed that Mn_(3)O_(4) exhibited a tetragonal spinel structure,and Fourier transformed infrared(FTIR)spectroscopy identified surfaceadsorbed functional *** electron microscopy(SEM)and the specific surface area analyses by Brunauer−Emmett−Teller(BET)revealed a porous,homogeneous surface composed of strongly agglomerated spherical grains with an estimated average particle size of∼35 nm,which corresponded to a large specific surface area of∼81.5 m^(2)/g.X-ray photoelectron spectroscopy(XPS)analysis indicated that Mn_(3)O_(4) was composed of metallic cations(Mn^(4+),Mn_(3)+,and Mn^(2+))and oxygen species(O_(2)−,Oh−and CO_(3)2−).The optical bandgap energy is∼2.55 *** of the catalytic performance of the Mn_(3)O_(4) SPs indicated T90 conversion of Ch4 to CO_(2) and h2O at 398℃ for gas hourly space velocity(GhSV)of 72000 mL^(3) g^(−1) h^(−1).This observed performance can be attributed to the cooperative effects of the smallest spherical grain size with a mesoporous structure,which is responsible for the larger specific surface area and available surface-active oxygenated *** cooperative effect of the good reducibility,higher ratio of active species(OLat/OAds),and results of density functional theory(DFT)calculations suggested that the total oxidation of Ch4 over the mesoporous Mn_(3)O_(4) SPs might take place via a two-term process in which both the Langmuir−hinshelwood and Mars−van Krevelen mechanisms are cooperatively involved.

关键词： Sol-gel Manganese oxide Catalytic oxidation Methane Langmuir−hinshelwood mechanism Mars−van Krevelen route Two−term process

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haplotype-based phylogenetic analysis and population genomics uncover the origin and domestication of sweetpotato

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Molecular Plant 2024年第2期17卷 277-296页

作者： Mengxiao Yan Ming Li Yunze Wang Xinyi Wang M-hossein Moeinzadeh Dora G.Quispe-huamanquispe Weijuan Fan Yijie Fang Yuqin Wang haozhen Nie Zhangying Wang Aiko Tanaka Bettina heider Jan F.Kreuze Godelieve Gheysen hongxia Wang Martin Vingron ralph Bock Jun Yang Shanghai Key Laboratory of Plant Functional Genomics and Resources Shanghai Chenshan Botanical GardenShanghai 201602China College of Life Sciences Chongqing Normal UniversityChongqing 401331China Biotechnology and Nuclear Technology Research Institute Sichuan Academy of Agricultural SciencesChengdu 610061China College of Life Sciences Shanghai Normal UniversityShanghai 200234China Department of Computational Molecular Biology Max Planck Institute for Molecular GeneticsIhnestraBe 63-7314195 BerlinGermany Department of Biotechnology Ghent University9000 GhentBelgium Guangdong Provincial Key Laboratory of Crops Genetics and Improvement Crop Research InstituteGuangdong Academy of Agricultural SciencesGuangzhou 510640China Graduate School of Bioagricultural Sciences Nagoya UniversityChikusaNagoya 464-8601Japan international Potato Center(CIP) LimaPeru CAS Center for Excellence of Molecular Plant Sciences Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai 200233China Max-Planck-Institut fur Molekulare Pflanzenphysiologie Am Muhlenberg 114476 Potsdam-GolmGermany

The hexaploid sweetpotato(lpomoea batatas)is one of the most important root crops ***,its genetic origin remains controversial,and its domestication history remains *** this study,we used a range of genetic evidence and a newly developed haplotype-based phylogenetic analysis to identify two probable progenitors of *** diploid progenitor was likely closely related to lpomoea ae-quatoriensis and contributed the B,subgenome,IbT-DNA2,and the lineage 1 type of chloroplast genome to *** tetraploid progenitor of sweetpotato was most likely *** 4x,which donated the B2 subgenome,IbT-DNA1,and the lineage 2 type of chloroplast *** most likely originated from reciprocal crosses between the diploid and tetraploid progenitors,followed by a subsequent whole-genome *** addition,we detected biased gene exchanges between the subgenomes;the rate of B,to B2 subgenome conversions was nearly three times higher than that of B2 to B subgenome *** analyses revealed that genes involved in storage root formation,maintenance of genome stabil-ity,biotic resistance,sugar transport,and potassium uptake were selected during the speciation and domestication of *** study sheds light on the evolution of sweetpotato and paves the way forimprovementofthiscrop.

关键词： sweetpotato origin gene conversion domestication IbT-DNA hPA

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West Meets East——Observations on Integrative Medicine in Rheumatology from the USA

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Chinese Journal of Integrative Medicine 2008年第3期14卷 165-166页

作者： h.ralph Schumacher University of Pennsylvania VA Medical Center151 KUniversity & Woodland AvesPhiladelphiaPA 19104U.S.A.

Integrating concepts and methods from Asia into standard academic Western medicine has been felt to offer important potential advantages. Western medicine methods of objective systematic evaluation can also offer pote... 详细信息

关键词： West Meets East Observations on Integrative Medicine in Rheumatology from the USA

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Differential effects on apoptosis induction in hepatocyte lines by stable expression of hepatitis B virus X protein

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World Journal of Gastroenterology 2006年第29期12卷 4673-4682页

作者： Nicola Fiedler Ellen Quant Ludger Fink Jianguang Sun ralph Schuster Wolfram h Gerlich Stephan Schaefer Institut for Medizinische Virologie Justus-LiebigUniversitat Frankfurter Str. 107 D-35392 GieBen Germany Abteilung fǖr Innere Medizin Christian AlbrechtUniversitat Kiel Germany Zentrum fǖr Innere Medizin Justus-LiebigUniversitat GieBen Germany Abteilung Virologie Universitat Rostock Schillingallee 70 18055 Rostock Germany Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing 100081 China

AIM： hepatitis B virus protein X （hBx） has been shown to be weakly oncogenic in vitro. The transforming activities of hBx have been linked with the inhibition of several functions of the tumor suppressor p53. We have studied whether hBx may have different effects on p53 depending on the cell type. METhODS： We used the human hepatoma cell line hepG2 and the immortalized murine hepatocyte line AML12 and analyzed stably transfected clones which expressed physiological amounts of hBx. P53 was induced by UV irradiation.RESULTS： The p53 induction by UV irradiation was unaffected by stable expression of hBx. however, the expression of the cyclin kinase inhibitor p21^waf/cip/sdi which gets activated by p53 was affected in the hBx transformed cell line AML12-hBx9, but not in hepG2. In AML-hBx9 cells, p21^waf/ciP/sdi -protein expression and p21^waf/dip/sdi transcription were deregulated. Furthermore, the process of apoptosis was affected in opposite ways in the two cell lines investigated. While stable expression of hBx enhanced apoptosis induced by UV irradiation in hepG2-cells, apoptosis was decreased in hBx transformed AML12-hBx9. P53 repressed transcription from the hBV enhancer I, when expressed from expression vectors or after induction of endogenous p53 by UV irradiation. Repression by endogenous p53 was partially reversible by stably expressed hBx in both cell lines.CONCLUSION： Stable expression of hBx leads to deregulation of apoptosis induced by UV irradiation depending on the cell line used. In an immortalized hepatocyte line hBx acted anti-apoptotic whereas expression in a carcinoma derived hepatocyte line hBx enhanced apoptosis.

关键词： Apoptosis hepatitis B virus hepatocyte lines

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On low-pass digital filters in oceanography

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Acta Oceanologica Sinica 1993年第2期12卷 183-196页

作者： Wang Jin ralph T.Cheng Institute of Oceanology Academia SinicaQingdao 266071China Department of Meteorology McGill University805 Sherbrook Street WestMontrealQuebec H3A 2K6Canada U.s.Geological Survey Menlo ParkCa 94025 USA

Two types of filters are widely used to remove semidirunal and diurnal tidal signals and other high frequency noises in *** first type of filters uses moving average with weights in time domain,and can be easily *** data will be lost at each end of the time series,especially for the low low-pass *** second type of filters uses the discrete Fourier transform filter(DFTF)which operates in the frequency domain,and there are no data loss at the ends for the forward ***,owing to the Gibbs phenomenon and the discrete sampling(Nyquist effect),ringing appears in the inverse transformed data,which is especially serious at each *** some data at the ends are also *** present study tries to find out what causes the ringing and then to seek for methods to overcome the *** have found that there are two kinds of ringings,one is the Gibbs phenomenon,as defined *** other is the'Nyquist'ringing due to sampling Nyquist critical *** former is due to the abrupt transition in frequency *** Gibbs and Nyquist effects show the ringing at each end of the filtered time ***,the use of a cosine taper or a linear taper on the window in the frequency domain makes the transition band smooth,so that the Gibbs phenomenon will be *** applying the Fast Fourier Transform(FFT),the original time series at each end is properly tapered by a split cosine bell that reduces significant ringing since this method limits the energy transfer from outside of the Nyquist ***,the DFTF can be a powerful tool to suppress the signals in which we are not interested,with sharp peaks in low frequency variation and less data loss at each end.

关键词： data On low-pass digital filters in oceanography

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Enhanced oil recovery of low salinity water flooding in sandstone and the role of clay

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Petroleum Exploration and Development 2018年第5期45卷 927-931页

作者： Al-SAEDI hasan N FLORI ralph E Missouri University of Science and Technology

Sandstone core and free-clay sandstone core were prepared in chromatography columns, and core flooding experiments were performed to determine the EOR mechanisms of low salinity（LS） water flooding and analyze the effect of clay on recovery factor. First, brine with a high salinity（hS） of 100 000 mg/L was injected to simulate formation water. Then, LS water of 1 000 mg/L was then injected at different temperatures. Concentrations of Ca;and Ch;COO;and ph of the fluid flowing out of the chromatography column were recorded. The results showed that during flooding the free-clay core with LS water, the carboxylic acid detached from the sand, as great as that of the clay-containing cores. It showed a noteworthy desorption of Ca;from the free-clay core surface, which indicated that LS water flooding resulted in a high recovery in sandstone without clay. Compared with hS water flooding, in the LS water flooding, the p h of produced fluid increased significantly; also, as the temperature increased, the ph and Ca;concentration of the produced fluid decreased; and the hydrophilic property of the sandstone was stronger. The results of oil recovery tests using the same columns were in line with the chemical analyses. The oil recovery from the free-clay columns was as great as from the column clay-containing column. The results of wettability measurements supported our theory.

关键词： sandstone reservoir low salinity water flooding enhanced oil recovery water-rock reaction wettability alteration clay

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Update in Gout and Other Microcrystalline Diseases:What is New or Controversial?

Update in Gout and Other Microcrystalline Diseases:What is N...

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中华医学会全国风湿病学年会

作者： h．ralph Schumacher University of Pennsylvania and VA Medical Center Philadelphia

*** Ⅰ . how accurate is diagnosis? ACR gout criteria are still "preliminary"since 1977. ACR criteria for RA can misdiagnose gout. Crystal diagnosis is definite,but how accurate is it? Errors are common Even rheumatologists often do not examine SF for crystals Serum mate is not diagnostic. Uric acid levels may be low during attacks. Inflammation itself may lower serum uric acid Ⅱ . Is it important to look for causes of hyperuricemia? Under-excretion is by far most common. Are there clues to a genetic basis?

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Establishing a dynamic US federal national vegetation classification process standard in partnership with non federal partners

Establishing a dynamic US federal national vegetation classi...

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ⅩⅪ International Grassland Congress and the Ⅷ International Rangeland Congress

作者： ralph h.Crawford US Forest Service Research and Development 1601 North Kent Street RPC-4 ArlingtonVirginia 22209

＜正＞Introduction The overall purpose of this Federal National Vegetation Classification Standard（NVC） is to support the development and use of a consistent national vegetation classification in order to produce uniform statistics about vegetation resources across the nation,based on vegetation data gathered at local,regional,or national levels.

关键词： vegetation types vegetation classification

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Synovial Fluid Analysis and Synovial Biopsy for the Rheumatologist

Synovial Fluid Analysis and Synovial Biopsy for the Rheumato...

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中华医学会全国风湿病学年会

作者： h．ralph Schumacher University of Pennsylvania and VA Medical Center Philadelphia MD

Ⅰ. Practical Approach to Synovial Fluid(SF) A. What aspects of SF analysis are likely to change diagnoses and treatments? 1. Gross appearance 2. Wet drop preparation Regular light Polarized light 3. Gram stain and cultures *** count and estimate *** by gross appearance C. Wet drop preparations 1. Miscellaneous findings *** and artifacts

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