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Characteristics of elution profile in radial chromatography under linear conditions

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Science China Chemistry 2005年第4期48卷 352-360页

作者： andreas Seidel-Morgenstern Max-Planck-Institut für Dynamik Komplexer Technischer Systeme 39106MagdeburgGermany

Based on the mass balance equations of solute transfer in the radial chroma-tographic column,the theoretical expression to describe the column efficiency and shape of elu-tion profile is obtained under linear isotherm ***,the tendency for the variation of column efficiency and symmetry of peak profile is systematically *** results showed that in radial chromatography the relationship between the column efficiency and volumetric flow rate is similar with that relationship in axial chromatography;relatively high column efficiency still can be obtained under high flow rate in radial *** the increase of retention factor of solutes and injection time,the column efficiency decreases *** effect of column diameter and column length on the column efficiency interfere with each *** is more advantageous to increase the column efficiency by applying columns with larger column diameter and shorter column *** to the discussion of the effect of diffusion on the column efficiency,radial chromatography is proved to be suitable for the separation of samples with relatively high diffusion coefficient,which predicts its obvious advantage in the preparative separation of samples such as proteins and DNA.

关键词： radial chromatography, column efficiency, elution profile, symmetry.

Multi-segment linear gradient optimization strategy based on resolution map in HPLC

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Science China Chemistry 2006年第4期49卷 315-325页

作者： andreas Seidel-Morgenstern Max-Planck-Institut fr Dynamik Komplexer Technischer Systeme Magdeburg 39106 Germany

Based on the mechanism of chromatographic retention (the relationship between the retention of solute and the mobile phase conditions) and method of resolution map, several methods of optimizing multi-segment linear gradient elution conditions were proposed according to the different separation requirements of various samples. These methods were verified using literature data. Moreover, the advantages and disadvantages of these methods were compared. It was proved that the third method is a fast optimization method which is capable of separating all the components with relatively high resolution.

关键词： optimization, multi-segment, linear gradient, resolution map, liquid chromatography.

Micro-annulus generation under downhole conditions: Insights from three-dimensional staged finite element analysis of cement hardening and wellbore operations

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第6期12卷 1185-1200页

作者： Weicheng Zhang andreas Eckert Department of Geosciences and Geological and Petroleum Engineering Missouri University of Science and TechnologyRollaMOUSA

A micro-annulus(MA)is defined as a high permeability zone or gap initiating/occurring at the casingcement and cement-formation interfaces during the wellbore life *** MA can significantly compromise wellbore integrity by establishing enhanced fluid flow *** study uses a staged finite element approach to simulate wellbore integrity during various loading steps of wellbore operations under downhole *** emphasis is placed on the processes of cement poro-elastic property evolution,volume variation,and pore pressure variation as part of the cement hardening *** resulting state of stress during the life cycle of a typical injection well(***,completion,and injection)is analyzed to assess the onset and evolution of micro-annuli at various interfaces of the composite wellbore system under downhole *** results show that cement shear failure is observed at the casing-cement interface during pressure testing(excessive wellbore pressure);and tensile debonding failure initiates at the cement-formation interface due to cement shrinkage during hardening and injection-related cooling(thermal cycling).Sensitivity analyses considering several parameters show that:(1)the degree of poro-elastic bulk shrinkage has significant implications for both shear and tensile failure initiation e the less the cement shrinks,the less likely the failure initiation is;(2)cement integrity increases with increasing depth;(3)cement pore pressure evolution has significant implications for tensile failure e if cement pore pressure decreases more,higher temperature differences can be sustained before an MA occurs;and(4)cement temperature fluctuations during hardening promote initiation of debonding *** summary,the results presented indicate that establishing downhole conditions to quantitatively analyze MA generation is *** results are different compared to laboratory studies without considering/simulating downhole *** kno

关键词： Micro-annulus Debonding Staged finite element analysis Cement hardening Poro-elastic bulk shrinkage Pore pressure Temperature fluctuation

Is hepatitis B-virucidal validation of biocides possible with the use of surrogates?

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World Journal of Gastroenterology 2014年第2期20卷 436-444页

作者： andreas Sauerbrei Institute of Virology and Antiviral Chemotherapy Jena University ClinicFriedrich Schiller University of JenaD-07745 JenaGermany

The hepatitis B virus(HBV)is considered to be a major public health problem worldwide,and a significant number of reports on nosocomial outbreaks of HBV infections have been *** of indirect HBV transmission by contaminated objects is only possible through the use of infection-control principles,including the use of chemical biocides,which are proven to render the virus *** virucidal activity of biocides against HBV cannot be predicted;therefore,validation of the virucidal action of disinfectants against HBV is ***,feasible HBV infectivity assays have not yet been ***,surrogate models have been proposed for testing the efficacy of biocides against *** of these assays do not correlate with HBV ***,the most promising and feasible assay is the use of the taxonomically related duck hepatitis B virus(DHBV),which belongs to the same Hepadnaviridae virus *** paper reviews the application of DHBV,which can be propagated in vitro in primary duck embryonic hepatocytes,for the testing of biocides and describes why this model can be used as reliable method to evaluate disinfectants for efficacy against *** susceptibility levels of important biocides,which are often used as ingredients for commercially available disinfectants,are also described.

关键词： Hepatitis B virus Surrogate model Duck hepatitis B virus Disinfectants Testing virucidal efficacy

High Responsivity and Ultra-Low Detection Limits in Nonlinear a-Si:H p-i-n Photodiodes Enabled by Photogating

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Photonic Sensors 2023年第4期13卷 27-38页

作者： andreas BABLICH Maurice MÜLLER Rainer BORNEMANN andreas NACHTIGAL Peter HARING BOLÍVAR Institute of Graphene-Based Nanotechnology University of SiegenHölderlinstr.357076 SiegenGermany Institute of High Frequency and Quantum Electronics University of SiegenHölderlinstr.357076 SiegenGermany

Photodetectors operating at the wavelength in the visible spectrum are key components in high-performance optoelectronic *** this work,massive nonlinearities in amorphous silicon p-i-n photodiodes enabled by the photogating are presented,resulting in responsivities up to 744 mA/W at blue *** detectors exhibit significant responsivity gains at optical modulation frequencies exceeding MHz and a more than 60-fold enhanced spectral response compared to the non-gated *** detection limits down to 10.4 nW/mm^(2) and mean signal-to-noise ratio enhancements of 8.5dB are demonstrated by illuminating the sensor with an additional 6.6μW/mm^(2) red ***-optical simulations verify photocarrier modulation due to defect-induced field screening to be the origin of such high responsivity *** experimental results validate the theory and enable the development of commercially viable and complementary metal oxide semiconductor(CMOS)compatible high responsivity photodetectors operating in the visible range for low-light level imaging and detection.

关键词： Photogating amorphous silicon a-Si:H nonlinearity photodetector responsivity gain

WNT/β-catenin-M2 macrophage interplay as a target for therapy against hepatocellular carcinoma:Role of Calculus bovis

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World Journal of Gastroenterology 2025年第3期31卷 130-133页

作者： Tryfonas Mpektsis Anastasios Manolakis andreas Kapsoritakis Department of Gastroenterology University Hospital of LarisaLarisa 41100Greece

Liver cancer,and in particular hepatocellular carcinoma(HCC)is a disease of rising prevalence and *** date,definitive treatment options include either surgical excision or ablation of the affected *** increasing research on several pathways that could be involved in the progression of HCC,new elements within these pathways emerge as potential targets for novel *** WNT/β-catenin pathway favors the presence of M2 tumor-associated macrophages which in turn promote tumor growth and *** inhibition of this pathway is considered a good candidate for such targeted therapeutic ***,as Huang et al show in their recently published article,Calculus bovis which is used in traditional Chinese medicine can exert an inhibitory effect on theβ-catenin pathway and become a potential candidate for targeted pharmacotherapy against liver cancer.

关键词： Hepatocellular carcinoma Calculus bovis WNT/β-catenin pathway Tumorassociated macrophages

Small scale adeno-associated virusvector production for preclinical gene delivery based on chloroform precipitation

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Neural Regeneration Research 2022年第1期17卷 99-100页

作者： Marcus Davidsson andreas Heuer Molecular Neuromodulation Department of Experimental Medical SciencesLund UniversityLundSweden Behavioural Neuroscience Laboratory Department of Experimental Medical SciencesLund UniversityLundSweden

Gene therapy aims to introduce genetic information into a cell-type of interest to replace,correct,silence,or modify defective *** therapy in its broadest sense can theoretically prevent,halt,or cure any condition that affects *** addition to that,the introduction and/or manipulation of genes is one of the major research areas in biological sciences,aimed to deepen our knowledge on how biological systems *** advances have made it possible to induce changes ranging from manipulations of large stretches of the genome to the change of single *** gold-standard vehicles to bring this genetic information into the target cells are viral vectors.

关键词： replace Small mankind

The interaction between a shaped charge jet and a single moving plate

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Defence Technology（防务技术） 2024年第1期31卷 1-13页

作者： andreas Helte Jonas Lundgren Jonas Candle FOI WeaponsProtection and SecuritySE-16490StockholmSweden

Reactive armour is a very efficient add-on armour against shaped charge *** reactive armour consists of one or several plates that are accelerated by an *** but less violent acceleration of plates can also be achieved in a completely inert reactive *** be efficient against elongated jets,the motion of the plates needs to be inclined against the jet such that a sliding contact between the jet and the plates is *** sliding contact causes a deflection and thinning of the *** certain circumstances,the contact will become unstable,leading to severe disturbances on the *** disturbances will drastically reduce the jet penetration performance and it is therefore of interest to study the conditions that leads to an unstable *** studies on the interaction between shaped charge jets and flyer plates have shown that it is mainly the forward moving plate in an explosive reactive armour that is effective in disturbing the *** is usually attributed to the higher plate-to-jet mass flux ratio involved in the collision of the forward moving plate compared to the backward moving *** slow moving plates,as occurs in inert reactive armour,the difference in mass flux for the forward and backward moving plate is much lesser,and it is therefore of interest to study if other factors than the mass flux influences on the protection *** this work,experiments have been performed where a plate is accelerated along its length,interacting with a shaped charge jet that is fired at an oblique angle to the plate’s normal,either against or along the plate’s *** arrangement corresponds to a jet interacting with a flyer plate from a reactive armour,with the exception that the collision velocity is the same for both types of obliquities in these *** experiments show that disturbances on the jet are different in the two cases even though the collision velocities are the *** simulatio

关键词： Reactive armour Flyer plate Shaped charge jet

Synthesis and Crystal Structure of an Anionic Linear Trinuclear Copper(Ⅱ) Complex Containing 2-Thenoyltrifluoroacetonato and Acetato Ligands

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Chinese Journal of Structural Chemistry 2014年第1期33卷 19-26页

作者： LOGANATHAN Nagarajan ROODT andreas Department of Chemistry University of the Free State

A novel anionic trinuclear linear copper（II） complex {[Et3NH][Cul.5（CH3COO）- （TTA）3] } 2 （1, TTA = 2-thenoyltrifluoroacetonate） has been synthesized in a direct reaction involving copper（]l） acetate monohydrate, TTA and excess triethylamine base in dichloromethane solvent. Green colored X-ray quality crystals of 1 were grown from n-hexane solvent at room temperature. The data were collected at 100 K. Compound I crystallizes in the monoclinic P21/n space group （a = 11.2141（8）, b = 19.0965（13）, c = 17.3680（14） A, β = 90.225（2）°, V= 3719.3（5） A3, Mr = 1840.14, Dc = 1.643 Mg/m3, F（000） = 1866, μ = 1.129 mm^-1 and Z = 2）. The asymmetric unit of 1 contains two copper atoms, one of which lies on a crystallographic inversion center with 50% occupancy.

关键词： copper crystals acetate monoclinic 1,3-diketonates