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Molecular Networks Regulating Meristem Homeostasis

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Molecular Plant 2018年第7期11卷 883-885页

作者： jan Traas Laboratoire de Reproduction et Developpement des Plantes INRA CNRS ENSL UCB Lyon I Universite de Lyon 46 allee d'ltalie 69364 Lyon Cedex 07 France

The shoot apical meristem （SAM）, which produces all the aerial parts of the plant, plays a major role in the establish- ment of plant architecture. In many higher plants, the SAM has a stereotypic organization in zones with different func- tions. At the summit of the dome-shaped meristem is a popu- lation of stem cells （called the central zone）, required for meristem maintenance. Part of the cells produced by the central zone will enter a differentiation pathway and their descendants will serve as founders for the stems and lateral organs at the meristem periphery （or peripheral zone）. During the last decades, much of the research on the SAM has focused on three major signaling cascades required for its function：

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Some recent advances in fluidized-bed polymerization technology

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Particuology 2010年第6期8卷 578-581页

作者： jan van Egmond Mike Tilston Union Carbide Corporation a subsidiary of The Dow Chemical CompanyFreeportTX 77541USA

The fluidized-bed polymerization process has been in use for decades. From the manufacturer＇s perspective it is desirable to improve technology without major modification of the reactor system. Therefore, in order to meet the demand for new products or more efficient reactor operation, manufacturers prefer to improve the catalyst system in the most cost effective manner. Using polypropylene production as an example, some recent advances in fluidized-bed polymerization technology are presented.

关键词： Fluidized bed Polymerization Polypropylene Catalyst Donor Kinetics

Behaviour of cranes(family Gruidae)mirrors their phylogenetic relationships

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Avian Research 2021年第3期12卷 285-295页

作者： Nela Nováková jan Robovský Faculty of Science University of South BohemiaBranišovská176037005ČeskéBudějoviceCzechia

Background:The behavioural repertoire of every species evolved over time and its evolution can be traced through the phylogenetic relationships in distinct ***(family Gruidae)represent a small,old,monophyletic group with well-corroborated phylogenetic relationships on the species level,and at the same time they exhibit a complex and well-described behavioural ***:We therefore investigated the evolution of behavioural traits of cranes in a phylogenetic context using several phylogenetic approaches and two types of trait *** cranes exhibit more than a hundred behavioural displays,almost one third of which may be phylogenetically ***:More than half of the analysed traits carry a significant phylogenetic *** ancestor of cranes already exhibited a quite complex behavioural repertoire,which remained unchanged in Balearicinae but altered greatly in Gruinae,specifically by the shedding of traits rather than their *** scoring has an influence on results within the Gruinae,primarily in genera Bugeranus and ***:Albeit the behavioural traits alone cannot be used for resolving species-level relationships within the Gruidae,when optimized on molecular tree,they can help us to detect interesting evolutionary transformations of behaviour repertoire within *** Limpkin(Aramus guarauna)seems to be the most enigmatic species and should be studied in detail for its behavioural repertoire,which may include some precursors of crane behavioural traits.

关键词： Ancestral behavioural repertoire Evolution Phylogenetic signal

CFB cyclones at high temperature:Operational results and design assessment

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Particuology 2008年第3期6卷 149-156页

作者： Raf Dewil jan Baeyens Bart Caerts Department of Chemical Engineering Associated Faculty of Technology and Bio-sciencesCampus De NayerKatholieke Universiteit LeuvenJan De Nayerlaan 5B-2860 Sint-Katelijne-WaverBelgium Department of Chemical Engineering University of BirminghamEdgbastonBirmingham B15 2TTUnited Kingdom Department of Chemical Engineering Katholieke Universiteit LeuvenWillem De Croylaan 46B-3001 HeverleeBelgium

Pressure drop and cut size measurements are reported for a full scale cyclone operating within a 58 MWth CFB-combustor unit at 775 ℃. The paper reviews the vast number of equations to calculate the pressure drop and separation efficiency of cyclones, generally for operation at ambient temperature and at low Cs [〈0.5]. None of the literature correlations predicts the pressure drop with a fair accuracy within the range of experimental operating conditions. The cut size d50 can be estimated using direct empirical methods or using the Stokes number, Stk50. Both methods were used to compare measured and predicted values of d50. With the exception of Muschelknautz and Krambrock, none of the equations made accurate predictions. Finally, an alternative method to determine the friction factor of the pressure drop equation （Euler number, Eu） and of the cut size is proposed. The Eu number is determined from the geometry of common cyclones, and the derived value of Stk50 defines more accurate cut sizes. The remaining discrepancy of less than 5%, when compared with the measured values, is tentatively explained in terms of a reduced cyclone diameter due to the solids layer formed near its wall. Further measurements, mostly using positron emission particle tracking, elucidate the particle motion in the cyclone and both tracking results and the influence of the particle movement on Eu and Stk50 will be discussed in a follow-up paper.

关键词： Cyclone High loading High temperature Combustor

Multiferroics under the tip: probing magnetoelectric coupling at the nanoscale

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National Science Review 2019年第4期6卷 626-628页

作者： Yunya Liu jan Seidel Jiangyu Li Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education School of Materials Science and Engineering Xiangtan University School of Materials Science and Engineering University of New South Wales ARC Centre of Excellence in Future Low-Energy Electronics Technologies University of New South Wales Shenzhen Key Laboratory of Nanobiomechanics Shenzhen Institutes of Advanced TechnologyChinese Academy of Sciences Department of Mechanical Engineering University of Washington

Multiferroic materials, with the coexistence of electric and magnetic orderings and thus exhibition of magnetoelectric coupling, offer an intriguing playground for controlling and understanding the structure of condensed matter interacting with external stimuli, and promise exciting opportunities for technological applications. While originally

关键词： Multiferroics under the tip probing magnetoelectric coupling at the nanoscale

Ethylene Controls Autophosphorylation of the Histidine Kinase Domain in Ethylene Receptor ETR1

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Molecular Plant 2008年第2期1卷 380-387页

作者： jan Voet-van-Vormizeele Georg Groth Heinrich-Heine-Universitat Biochemie der Pflanzen Universitatsstr. 1 40225 Duisseldorf Germany

Perception of the phytohormone ethylene is accomplished by a small family of integral membrane receptors. In Arabidopsis, five ethylene receptor proteins are known, including ethylene resistant I （ETR1）. The hydrophobic aminoterminal domain of these receptors contains the ethylene-binding site while the carboxyl-terminal part consists of a histidine kinase domain and a response regulator domain, which are well known elements found in bacterial two-component signaling. The soluble membrane-extrinsic carboxyl-terminal part of the receptor, which is likely to play an important role in signal transduction, showed intrinsic kinase activity when expressed and purified on its own. However, a correlation between signal input and autokinase activity was not established in these studies, as receptors were missing the trans- membrane amino-terminal sensor domain. Thus, it is still unclear whether autophosphorylation occurs in response to perception of the ethylene signal. Here, we report on autophosphorylation studies of purified full-length ETR1. Autoki- nase activity of the purified receptor is controlled by ethylene or by ethylene agonists like the π-acceptor compound cyanide. In fact, both signal molecules were able to completely turn off the intrinsic kinase activity, Furthermore, the observed inhibition of autophosphorylation in ETR1 by both molecules could be prevented when the ethylene antagonist 1-methyl-cyclopropene （MOP） was applied.

关键词： ethylene pathway phytohormone receptor membrane protein two-component system signaltransduction Arabidopsis thaliana,

Fiber effects in nutrition and gut health in pigs

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Journal of Animal Science and Biotechnology 2014年第3期5卷 273-279页

作者： jan Erik Lindberg Department of Animal Nutrition and Management Swedish University of Agricultural Sciences

Dietary fiber is associated with impaired nutrient utilization and reduced net energy values. However, fiber has to be included in the diet to maintain normal physiological functions in the digestive tract. Moreover, the negative impact of dietary fiber will be determined by the fiber properties and may differ considerably between fiber sources. Various techniques can be applied to enhance nutritional value and utilization of available feed resources. In addition, the extent of fiber utilization is affected by the age of the pig and the pig breed. The use of potential prebiotic effects of dietary fiber is an attractive way to stimulate gut health and thereby minimize the use of anti-microbial growth promoters. Inclusion of soluble non-starch polysaccharides （NSP） in the diet can stimulate the growth of commensal gut microbes, inclusion of NSP from chicory results in changes in gut micro-environment and gut morphology of pigs, while growth performance remains unaffected and digestibility was only marginally reduced. The fermentation products and pH in digesta responded to diet type and were correlated with shifts in the microbiota. Interestingly, fiber intake will have an impact on the expression of intestinal epithelial heat-shock proteins in the pig. Heat-shock proteins have an important physiological role in the gut and carry out crucial housekeeping functions in order to maintain the mucosal barrier integrity. Thus, there are increasing evidence showing that fiber can have prebiotic effects in pigs due to interactions with the gut micro-environment and the gut associated immune system.

关键词： Breed Gut health Fiber Pigs Prebiotics Utilization

Interesting effects in harmonic generation by plane elastic waves

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Acta Mechanica Sinica 2017年第4期33卷 754-762页

作者： Yanzheng Wang jan D.Achenbach Department of Engineering Mechanics Zhejiang University Department of Mechanical Engineering Northwestern University

The harmonics of plane longitudinal and transverse waves in nonlinear elastic solids with up to cubic nonlinearity in a one-dimensional setting are investigated in this paper. It is shown that due to quadratic nonlinearity, a transverse wave generates a second longitudinal *** propagates with the velocity of transverse waves, as well as resonant transverse first and third harmonics due to the cubic and quadratic nonlinearities. A longitudinal wave generates a resonant longitudinal second harmonic, as well as first and third harmonics with amplitudes that increase linearly and quadratically with distance propagated. In a second investigation, incidence from the linear side of a primary wave on an interface between a linear and a nonlinear elastic solid is considered. The incident wave crosses the interface and generates a harmonic with interface conditions that are equilibrated by compensatory waves propagating in two directions away from the interface. The back-propagated compensatory wave provides information on the nonlinear elastic constants of the material behind the interface. It is shown that the amplitudes of the compensatory waves can be increased by mixing two incident longitudinal waves of appropriate frequencies.

关键词： harmonic longitudinal resonant transverse nonlinearity cubic incident solids propagating constants

SYNTHESIS,CHARACTERIZATION AND ENHANCED ELECTRICAL PROPERTIES OF CTAB-DIRECTED POLYANILINE NANOPARTICLES

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Chinese Journal of Polymer Science 2011年第2期29卷 181-190页

作者： Lal Said jan Mohamed Ahmed Siddig Department of Physics Postgraduate College Mardan23200Khyber PakhtunkhwaPakistan School of Physics and Applied Physics Faculty of Science and TechnologyEL Neelain UniversityKhartoumSudan

Inverse microemulsion system of cetyltrimethylammonium bromide（CTAB） molecules is utilized for virtually monodispersed and controlled growth of HCl polyaniline（PANI） nanoparticles at room temperature（ca.300 K）.The templated electroconductive polymer reveals lamellar crystalline structure under X-ray diffraction signifying marked sub-chain alignment of the polymerized *** nanostructured polymer has spherically symmetric morphology in a size range of 2.0 nm to 6.0 nm under electron microscope *** permeation chromatography gives polydispersity index of 1.02 for nanostructured polymer in agreement with the size monodispersity transpired by electron *** *** conductivityσ_（dc） of PANI at room temperature is 10.11 S/cm whereas the variation of conductivity with temperature in the range 227-303 *** that the conducting mechanism can be considered as three-dimensional variable-range-hopping（3D-VRH）.UV-Vis spectrum indicates two broad absorption bands due to polaron formation that contributes to enhanced electrical conductivity of the *** fundamental absorption edge in the polymer is formed by direct allowed transitions to the extent that the optical band gap value was found to be 2.35 *** crystalline nanostructure and homogeneous doping attained in the cationic template of amphiphile are argued as contributing factors to the enhanced conductivity of the polymer.

关键词： Polyaniline Nanostructured Band gap energy Electrical conductivity