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Transport receptor occupancy in nuclear pore complex mimics

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Nano Research 2022年第11期15卷 9689-9703页

作者： Alessio Fragasso Hendrik W.de Vries John Andersson Eli Ovan der Sluis erik van der giessen Patrick R.Onck Cees Dekker Department of Bionanoscience Kavli Institute of NanoscienceDelft University of TechnologyVan der Maasweg 9Delft 2629 HZThe Netherlands Zernike Institute for Advanced Materials University of GroningenNijenborgh 4Groningen 9747AGThe Netherlands Department of Chemistry and Chemical Engineering Chalmers University of TechnologyKemivägen 10Gothenburg SE-41296Sweden

Nuclear pore complexes(NPCs)regulate all molecular transport between the nucleus and the cytoplasm in eukaryotic *** disordered Phe-Gly nucleoporins(FG-Nups)line the central conduit of NPCs to impart a selective barrier where large proteins are excluded unless bound to a transport receptor(karyopherin;Kap).Here,we assess“Kap-centric”NPC models,which postulate that Kaps participate in establishing the selective *** combine biomimetic nanopores,formed by tethering Nsp1 to the inner wall of a solid-state nanopore,with coarse-grained modeling to show that yeast Kap95 exhibits two populations in Nsp1-coated pores:one population that is transported across the pore in milliseconds,and a second population that is stably assembled within the FG mesh of the *** current measurements show a conductance decrease for increasing Kap concentrations and noise data indicate an increase in rigidity of the *** reveals an accumulation of Kap95 near the pore wall,yielding a conductance *** find that Kaps only mildly affect the conformation of the Nsp1 mesh and that,even at high concentrations,Kaps only bind at most 8%of the FG-motifs in the nanopore,indicating that Kap95 occupancy is limited by steric constraints rather than by depletion of available *** data provide an alternative explanation of the origin of bimodal NPC binding of Kaps,where a stable population of Kaps binds avidly to the NPC periphery,while fast transport proceeds via a central FG-rich channel through lower affinity interactions between Kaps and the cohesive domains of Nsp1.

关键词： nuclear pore complex intrinsically disordered proteins nuclear transport receptors karyopherins nanopores biomimetics molecular dynamics coarse-grained modeling

Indentation of elastically soft and plastically compressible solids

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Acta Mechanica Sinica 2015年第4期31卷 473-480页

作者： A.Needleman V.Tvergaard E.van der giessen Department of Materials Science and Engineering Texas A&M University College Station Department of Mechanical Engineering The Technical University of Denmark Zernike Institute for Advanced Materials University of Groningen

The effect of soft elasticity, i.e., a relatively small value of the ratio of Young＇s modulus to yield strength and plastic compressibility on the indentation of isotropically hardening elastic-viscoplastic solids is investigated. Calcu- lations are carried out for indentation of a perfectly sticking rigid sharp indenter into a cylinder modeling indentation of a half space. The material is characterized by a finite strain elastic-viscoplastic constitutive relation that allows for plas- tic as well as elastic compressibility. Both soft elasticity and plastic compressibility significantly reduce the ratio of nomi- nal indentation hardness to yield strength. A linear relation is found between the nominal indentation hardness and the log- arithm of the ratio of Young＇s modulus to yield strength, but with a different coefficient than reported in previous studies. The nominal indentation hardness decreases rapidly for small deviations from plastic incompressibility and then decreases rather slowly for values of the plastic Poisson＇s ratio less than 0.25. For both soft elasticity and plastic compressibility, the main reason for the lower values of indentation hardness is related to the reduction in the hydrostatic stress level in the material below the indenter.

关键词： Plasticity Compressibility Indentation Finite element analysis

LARGE STRAIN TORSION OF AXIALLY-CONSTRAINED SOLID RUBBER BARS

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Acta Mechanica Sinica 1994年第2期10卷 136-149页

作者： P.D. Wu K.W. Neale E. van der giessen On leave from Universite de Sherbrooke Sherbrooke Quebec Canada Laboratory for Engineering Mechanics Faculty of Mechanical Engineering and Marine Technology Delft University of Technology The Netherlands

Large strain fixed-end torsion of circular solid rubber bars is studied semi-analytically. The analyses are based on various non-Gaussian network models for rubber elasticity, some of which were proposed very recently. Results are presented in terms of predicted torque vs. twist curves and axial force vs. twist curves. In some cases, the predicted stress distributions are also given. The sensitivity of the second-order axial force to the employed models is considered. The predicted results are compared with experimental results found in the literature.

关键词： rubber network model large strain torsion

Skewed superstatistical distributions from a Langevin and Fokker-Planck approach

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Chinese Science Bulletin 2011年第34期56卷 3633-3638页

作者： van der STRAETEN erik BECK Christian Queen Mary University of London School of Mathematical Sciences

The superstatistics concept is a useful statistical method to describe inhomogeneous complex systems for which a system parameter βfluctuatesonalargespatio-temporal scale. Inthispaper weanalyze ameasuredtimeseriesofwindspeed fluctuationsandextract the superstatistical distribution function f(β) directly from the data. We construct suitable Langevin and Fokker-Planck models with a position dependent β-field and show that they reduce to standard type of superstatistics in the overdamped limit.

关键词：普朗克复杂系统统计方法时间尺度分布函数位置相关不均匀过阻尼

Metal-Free Decarboxylation ofα,β-Unsaturated Carboxylic Acids for Carbon-Carbon and Carbon-Heteroatom Coupling Reactions

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Chinese Journal of Chemistry 2020年第12期38卷 1780-1792页

作者： Xianjun Xu erik Vvan der Eycken Huangdi Feng College of Chemistry and Chemical Engineering&Shanghai Engineering Research Center of Textile Chemistry and Cleaner Production Shanghai University of Engineering Science333 Longteng RoodShanghai 201620China Laboratory for Organic&Microwave-Assisted Chemistry(LOMAC) Department of ChemistryKU LeuvenCelestijnenlaon 200FLeuven 3001Belgium Peoples Friendship University of Russia(RUDN University) 6 Miklukho-Maklaya StreetMoscow 117198Russia

Metal-free decarbox)lative couplig reactions represent an alternative paradigm for carbon-carbon or carbon-heteroatom bond formation that com-plement more traditional metal catalysis *** this review recent advances in metal-fre decarboxlation reactions of a.J-unsaturated carbowyic acids are *** major reaction classes are covered:1)generation of C-C,C-N C-S,-X bonds using propioic acids;2)transformations ofalkenyl acids for C-C,C-P,C-N.C-S,C-X *** cases involving electrochemisty and photochemistry represent a frontier area for carbon-carbon and carbon-heteroatom coupling *** the proposed mechanisms for both types of reactions are discussed.

关键词： processes. bonds frontier

Synthesis of nitrogen-tethered 1,6-enynes through CuI/TFA catalysis

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Organic Chemistry Frontiers 2022年第2期9卷 394-399页

作者： Leilei Cao Liliang Huang Xianjun Xu erik V.van der Eycken Huangdi Feng College of Chemistry and Chemical Engineering Shanghai University of Engineering ScienceShanghai201620China Laboratory for Organic&Microwave-Assisted Chemistry(LOMAC) Department of ChemistryKU LeuvenCelestijnenlaan 200FLeuvenB-3001Belgium Shanghai Peoples’Friendship University of Russia(RUDN University) Miklukho-Maklaya Street 6Moscow117198Russia Shanghai Frontiers Science Research Center for Druggability of Cardiovascular noncoding RNA Institute for Frontier Medical TechnologyShanghai University of Engineering ScienceShanghai201620China

A novel method for the concise and effective construction of nitrogen-tethered 1,6-enynes in moderate to good yields was *** transformation involves a TFA-promoted Pictet-Spengler reaction/iminium formation,copper-catalyzed alkyne-iminium ene reaction/alkynylation of a 2-arylethan-1-amine,formaldehyde solution,and a terminal *** process features exclusive chemoselectivity,simple operation,and high atom *** experimental studies suggest that the alkyne-iminium ene reaction involving an intermolecular hydride transfer is the key step in the current methodology.

关键词： catalysis hydride promoted

Artificial intelligence for characterization of diminutive colorectal polyps:A feasibility study comparing two computer-aided diagnosis systems

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Artificial Intelligence in Gastrointestinal Endoscopy 2024年第1期5卷 11-22页

作者： Quirine Eunice Wennie van der Zander Ramon M Schreuder Ayla Thijssen Carolus H J Kusters Nikoo Dehghani Thom Scheeve Bjorn Winkens Mirjam C M van der Ende-van Loon Peter H N de With Fons van der Sommen Ad A M Masclee erik J Schoon Department of Gastroenterology and Hepatology Maastricht University Medical CenterMaastricht 6202 AZNetherlands GROW School for Oncology and ReproductionMaastricht UniversityMaastricht 6200 MDNetherlands Division of Gastroenterology and Hepatology Catharina Hospital EindhovenEindhoven 5602 ZANetherlands Department of Electrical Engineering Eindhoven University of TechnologyEindhoven 5600 MBNetherlands Department of Methodology and Statistics Maastricht UniversityPostbus 6166200 MD MaastrichtNetherlands School for Public Health and Primary Care Maastricht UniversityMaastricht 6200 MDNetherlands

BACKGROUND Artificial intelligence(AI)has potential in the optical diagnosis of colorectal *** To evaluate the feasibility of the real-time use of the computer-aided diagnosis system(CADx)AI for ColoRectal Polyps(AI4CRP)for the optical diagnosis of diminutive colorectal polyps and to compare the performance with CAD EYE^(TM)(Fujifilm,Tokyo,Japan).CADx influence on the optical diagnosis of an expert endoscopist was also *** AI4CRP was developed in-house and CAD EYE was proprietary software provided by *** CADxsystems exploit convolutional neural *** polyps were characterized as benign or premalignant and histopathology was used as gold ***4CRP provided an objective assessment of its characterization by presenting a calibrated confidence characterization value(range 0.0-1.0).A predefined cut-off value of 0.6 was set with values0.76).Self-critical AI4CRP’s diagnostic performances excluded low confidence *** AI4CRP use was feasible and performed on 30 patients with 51 colorectal ***-critical AI4CRP,excluding 14 low confidence characterizations[27.5%(14/51)],had a diagnostic accuracy of 89.2%,sensitivity of 89.7%,and specificity of 87.5%,which was higher compared to *** EYE had a 83.7%diagnostic accuracy,74.2%sensitivity,and 100.0%*** performances of the endoscopist alone(before AI)increased nonsignificantly after reviewing the CADx characterizations of both AI4CRP and CAD EYE(AI-assisted endoscopist).Diagnostic performances of the AI-assisted endoscopist were higher compared to both CADx-systems,except for specificity for which CAD EYE performed *** Real-time use of AI4CRP was *** confidence values provided by a CADx is novel and self-critical AI4CRP sho

关键词： Artificial intelligence Colorectal polyp characterization Computer aided diagnosis Diminutive colorectal polyps Optical diagnosis Self-critical artificial intelligence

Surface functionalized N-C-TiO_(2)/C nanocomposites derived from metal-organic framework in water vapour for enhanced photocatalytic H generation

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Journal of Energy Chemistry 2021年第6期30卷 485-495,I0012页

作者： Mian Zahid Hussain Zhuxian Yang Bart van der Linden Zheng Huang Quanli Jia erik Cerrato Roland A.Fischer Freek Kapteijn Yanqiu Zhu Yongde Xia College of Engineering Mathematics and Physical SciencesUniversity of ExeterExeter EX44QFUnited Kingdom Department of Chemistry and Catalysis Research Center Technical University of MunichGarching 85748Germany Catalysis Engineering Chemical Engineering DepartmentDelft University of Technologyvan der Maasweg92629 HZ DelftNetherlands Henan Key Laboratory of High Temperature Functional Ceramics Zhengzhou UniversityZhengzhou 450052HenanChina Department of Chemistry University of TurinVia P.Giuria710125 TurinItaly

Surface-functionalized nitrogen/carbon co-doped polymorphic TiO_(2) phase junction nanoparticles uniformly distributed in porous carbon matrix were synthesized by a simple one-step pyrolysis of titanium based metal-organic framework(MOF),NH_(2)-MIL^(-1)25(Ti) at 700℃ under water vapour *** water vapour during the pyrolysis of NH_(2)-MIL^(-1)25(Ti) not only functionalizes the derived porous carbon matrix with carboxyl groups but also forms additional oxygen-rich N like interstitial/intraband states lying above the valence band of TiO2 along with the self-doped carbo n,which further narrows the energy band gaps of polymorphic TiO2 nanoparticles that enhance photocatalytic charge transfer *** co-catalyst,sample N-C-TiO2/CArW demonstrates H_(2) evolution activity of 426 μmol gcat-1h^(-1),which remarkably outperforms commercial TiO_(2)(P-25) and N-C-TiO_(2)/CAr with a 5-fold and 3-fold H_(2) generation,*** study clearly shows that water vapour atmosphere during the pyrolysis increases the hydrophilicity of the Ti-MOF derived composites by functionalizing porous carbon matrix with carboxylic groups,as well as enhancing the electrical conductivity and charge transfer efficiency due to the formation of additional localized oxygen-rich N like interstitial/intraband *** work also demonstrates that by optimizing the anatase-rutile phase composition of the TiO2 polymorphs,tuning the energy band gaps by N/C co-doping and functionalizing the porous carbon matrix in the N-C-TiO2/C nanocomposites,the photocatalytic H_(2) generation activity can be further enhanced.

关键词： Metal-organic framework TiO_(2) Porous carbon Nanocomposite Photocatalysis Hydrogen generation

Physical and chemical changes of rapeseed meal proteins during toasting and their effects on in vitro digestibility

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Journal of Animal Science and Biotechnology 2017年第2期8卷 417-427页

作者： Sergio Salazar-Villanea erik M.A.M.Bruininx Harry Gruppen Wouter H.Hendriks Patrick Carré Alain Quinsac Antonius F.B.van der Poel Wageningen Livestock Research P.O.Box 3386700 AH WageningenThe Netherlands Animal Nutrition Group Wageningen University&ResearchP.O.Box 3386700 AH WageningenThe Netherlands Agfifirm Innovation Center Royal Dutch Agrifirm GroupP.O.Box 200187302 HA ApeldoornThe Netherlands Laboratory of Food Chemistry Wageningen University&ResearchP.O.Box 176700 AA WageningenThe Netherlands CREOL/OLEAD 11 rue MongeParc Industriel33600 PessacFrance Terres Inovia 11 rue MongeParc Industriel33600 PessacFrance

Background： Toasting during the production of rapeseed meal（RSM） decreases ileal crude protein（CP） and amino acid（AA） digestibility. The mechanisms that determine the decrease in digestibility have not been fully elucidated. A high protein quality, low-denatured, RSM was produced and toasted up to 120 min, with samples taken every 20 min. The aim of this study was to characterize secondary structure and chemical changes of proteins and glucosinolates occurring during toasting of RSM and the effects on its in vitro CP ***： The decrease in protein solubility and the increase of intermolecular β-sheets with increasing toasting time were indications of protein aggregation. The contents of NDF and ADIN increased with increasing toasting *** of arginine, lysine and O-methylisourea reactive lysine（OMIU-RL） linearly decreased with increasing toasting time, with a larger decrease of OMIU-RL than lysine. First-order reactions calculated from the measured parameters show that glucosinolates were degraded faster than lysine, OMIU-RL and arginine and that physical changes to proteins seem to occur before chemical changes during toasting. Despite the drastic physical and chemical changes noticed on the proteins, the coefficient of in vitro CP digestibility ranged from 0.776 to 0.750 and there were no effects on the extent of protein hydrolysis after 120 min. In contrast, the rate of protein hydrolysis linearly decreased with increasing toasting time, which was largely correlated to the decrease in protein solubility, lysine and OMIU-RL observed. Rate of protein hydrolysis was more than 2-fold higher for the untoasted RSM compared to the 120 min toasted ***： Increasing the toasting time for the production of RSM causes physical and chemical changes to the proteins that decrease the rate of protein hydrolysis. The observed decrease in the rate of protein hydrolysis could impact protein digestion and utilization.

关键词： Hydrolysis rate In vitro protein digestibility Rapeseed meal Reactive lysine Secondary structure