检索结果-南通市图书馆

A shoe-box-sized 3D laser nanoprinter based on two-step absorption

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Advanced Manufacturing) 2024年第2期5卷 115-122页

作者： Tobias Messer Michael Hippe Jingya(Lilyn)Gao Martin Wegener institute of Applied Physics(APH) Karlsruhe Institute of Technology(KIT)76128 KarlsruheGermany institute of Nanotechnology(INT) Karlsruhe Institute of Technology(KIT)76128 KarlsruheGermany

State-of-the-art commercially available 3D laser micro-and nanoprinters using polymeric photoresists based on two-or multi-photon absorption rely on high-power pico-or femtosecond lasers,leading to fairly large and expensive ***,we have introduced photoresists based on two-step absorption instead of two-photon absorption,allowing for the use of small and inexpensive continuous-wave 405 nm wavelength GaN semiconductor laser diodes with light-output powers below 1 ***,using the identical photoresist system and similar laser diodes,we report on the design,construction,and characterization of a 3D laser nanoprinter that fits into a shoe *** shoe box contains all optical components,namely the mounted laser,the collimation-and beam-shaping optics,a miniature MEMS xy-scanner,a tube lens,the focusing microscope objective lens(NA=1.4,100×magnification),a piezo slip-stick z-stage,the sample holder,a camera monitoring system,LED sample illumination,as well as the miniaturized control electronics employing a *** present a gallery of example 3D structures printed with this *** achieve about 100 nm lateral spatial resolution and focus scan speeds of about 1 mm/***,our shoe-box-sized system can be made orders of magnitude less expensive than today’s commercial systems.

关键词： Two-step absorption Direct laser writing 3D laser nanoprinters Micro-electro-mechanical-systems scanner 3D nanostructures

Differential Regulation of Carbon Partitioning by the Central Growth Regulator Target of Rapamycin （TOR）

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2013年第6期6卷 1731-1733页

作者： Yi Zhang, Staffan Persson Patrick Giavalisco max-planck-institute of Molecular Plant Physiology Am Muehlenberg 1 14476 Potsdam Germany

Target of rapamycin （TOR） is an evolutionary conserved ser- ine/threonine protein kinase found in yeast, plants, and ani- mals. TOR plays a central role in sensing nutrients and energy status, growth factors, and other environmental signals, and integrates these cues to synchronize cell growth-related pro- cesses （Laplante and Sabatini, 2012）. In yeast and animal cells, TOR acts as the catalytic component in two structurally and functionally distinct protein complexes termed TORC （TOR complex） 1 and TORC2. TOR seems to be localized specifi- cally to the endomembrane system and the nucleus with a certain mobility, depending on the environmental conditions （Laplante and Sabatini, 2012）. The three major components of TORCl, namely TOR, RAPTOR （Regulatory associated protein of mTOR）, and LST8 （Lethal with Sec13 protein 8）, are present in the genome of Arabidopsis, and interactions between TOR and RAPTOR, as well as TOR and LST8, occur also in plants, indicating the existence of a plant TORC1 （Moreau et al., 2012）. Here, we highlight the possible role of TOR in carbon utilization and growth regulation in Arabidopsis.

关键词： Target of Rapamycin (TOR) Arabidopsis carbon

Cytomegalovirus infection in non-immunocompromised critically ill patients:A management perspective

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Virology 2024年第1期13卷 38-50页

作者： Madhura Bhide Omender Singh Prashant Nasa Deven Juneja institute of Critical Care Medicine Max Super Speciality HospitalSaketNew Delhi 110017India Department of Critical Care Medicine NMC Specialty HospitalDubai 7832United Arab Emirates

Critically ill patients are a vulnerable group at high risk of developing secondary *** disease severity,prolonged intensive care unit(ICU)stay,sepsis,and multiple drugs with immunosuppressive activity make these patients prone to immuneparesis and increase the risk of various opportunistic infections,including cytomegalovirus(CMV).CMV seroconversion has been reported in up to 33%of ICU patients,but its impact on patient outcomes remains a matter of *** though there are guidelines regarding the management of CMV infection in immunosuppressive patients with human immunodeficiency virus/acquired immuno deficiency syndrome,the need for treatment and therapeutic approaches in immunocompetent critically ill patients is still *** the diagnosis of CMV infection may be challenging in such patients due to non-specific symptoms and multiorgan ***,a better understanding of the symptomatology,diagnostics,and treatment options may aid intensive care physicians in ensuring accurate diagnoses and instituting therapeutic interventions.

关键词： Cytomegalovirus Critically ill Immunocompetent Intensive care unit Virus

Changes in Atlantic Thermohaline Circulation under Different Atmospheric CO_2 Scenarios in a Climate Model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of China University of Geosciences 2006年第4期17卷 326-331页

作者：牟林吴德星陈学恩 institute of Physical Oceanography Ocean University of China Qingdao 266003 China max-planck institute for Meteorology Hamburg 20146 Germany

The changes in the thermohaline circulation （THC） because of the increased CO2 in the atmosphere play an important role in future climate regimes. In this article, a new climate model developed at the max-planck institute for Meteorology is used to study the variation in THC strength, the changes of North Atlantic deep-water （NADW） formation, and the regional responses of the THC in the North Atlantic to increasing atmospheric CO2. From 2000 to 2100, under increased CO2 scenarios （B1, AIB, and A2）, the strength of THC decreases by 4 Sv （106 m^3/s）, 5.1 Sv, and 5.2 Sv, respectively, equivalent to a reduction of 20%, 25%, and 25.1% of the present THC strength. The analyses show that the oceanic deep convective activity significantly strengthens in the Greenland-leeland-Norway （GIN） Seas owing to saltier （denser） upper oceans, whereas weakens in the Labrador Sea and in the south of the Denmark Strait region （SDSR） because of surface warming and freshening due to global warming. The saltiness of the GIN Seas is mainly caused by the increase of the saline North Atlantic inflow through the Faro-Bank （FB） Channel. Under the scenario A1B, the deep-water formation rate in the North Atlantic decreases from 16.2 Sv to 12.9 Sv with increasing CO2.

关键词： thermohaline circulation (THC) greenhouse gases deepwater.

High temperature tensile,compression and creep behavior of recycled short carbon fibre reinforced AZ91 magnesium alloy fabricated by a high shearing dispersion technique

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2021年第5期9卷 1773-1787页

作者： Sinan Kandemir Sarkis Gavras Hajo Dieringa Department of Mechanical Engineering Izmir Institute of Technology35430UrlaIzmirTurkey Helmholtz-Zentrum Hereon MagIC-Magnesium Innovation CentreMax-Planck-Straße 121502GeesthachtGermany Helmholtz-Zentrum Hereon Institute of Metallic BiomaterialsMax-Planck-Straße 121502GeesthachtGermany Helmholtz-Zentrum Hereon Institute of Materials and Process DesignMax-Planck-Straße 121502GeesthachtGermany

The present study seeks the feasibility of using short carbon fibres recycled from polymer matrix composites as alternative to virgin carbon fibres in the reinforcement of magnesium *** microstructures,high temperature mechanical and creep properties of AZ91 alloy and its composites with various recycled carbon fibre contents(2.5 and 5 wt.%)and lengths(100 and 500μm)were investigated in the temperature range of 25-200℃.The microstructural characterization showed that the high shear dispersion technique provided the cast composites with finer grains and relatively homogenous distribution of *** materials tested displayed different behaviour depending on the type of *** general,while enhancements in the mechanical properties of composites is attributed to the load bearing and grain refinement effects of fibres,the fluctuations in the properties were discussed on the basis of porosity formation,relatively high reinforcement content leading to fibre clustering and interlayer found between the matrix and reinforcement compared to those of AZ91 *** compressive creep tests revealed similar or higher minimum creep rates in the recycled carbon fibre reinforced AZ91 in comparison to the unreinforced AZ91.

关键词： Metal matrix composites Magnesium alloys Recycled carbon fibre High-shear dispersion Microstructure Mechanical properties Creep

CALCULATION OF THE YOUNG'S MODULUS OF AN ADSORBED POLYMER LAYER

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2007年第1期25卷 95-105页

作者： Rüdiger Stark Michael Kappl Hans-Jürgen Butt max-planck-institute for Polymer Research Ackermannweg 1055128 MainzGermany

Polymer layers adsorbed to a surface or in a confined environment often change their mechanical properties. There is even the possibility of solidification of the confined layer. To judge the stiffness of such a layer, we used the Hertz model to calculate the Young＇s modulus of the polymer layer in the confinement of AFM experiments with silicon nitride tip with a radius of curvature ofR ≈ 50 nm and a glass sphere attached to the cantilever R =5 μm. Since there is no visible indentation of the layer in the AFM experiments, the layer is either penetrated very easily, or the indentation is too small to be seen in a force curve. The latter would be the case for a polymer layer with a Young＇s modulus above 4 × 10^8 Pa in case of an experiment with a silicon nitride tip and 4×10^5 Pa in case of a glass sphere.

关键词： AFM PDMS PI Confined polymer Young's modulus Solidification.

Cell orientation of swimming bacteria:From theoretical simulation to experimental evaluation

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2012年第3期55卷 202-209页

作者： PING LiYan max planck institute.for Chemical Ecology Beutenberg Campus Jena 07745 Germany

The motion of small bacteria consists of two phases:relatively long runs alternate with intermittent stops,back-ups,or tumbles,depending on the *** polar monotrichous bacteria,the flagellum is anchored at the cell pole inherited from the parent generation(old pole) and is surrounded by a chemoreceptor *** forward swimming,the leading pole is always the pole recently formed in cell division(new pole).The flagella of the peritrichous bacterium Escherichia coli often form a bundle behind the old *** cell orientation and receptor positioning during runs generally mimic that of monotrichous *** encountering a solid surface,peritrichous bacteria exhibit a circular motion with the leading pole dipping *** polar monotrichous bacteria also perform circular motion near solid boundaries,but during *** this case,the leading pole points *** little is known about behavior near milieu-air *** simulations have revealed some of the mechanisms underlying these phenomena,but leave many questions *** biophysics with molecular techniques will certainly advance our understanding of bacterial locomotion.

关键词： bacterial motion cell orientation hydrodynamic interaction Brownian motion wall effect

Sex ratio of mirid populations shifts in response to hostplant co-infestation or altered cytokinin signaling

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant biology 2017年第1期59卷 44-59页

作者： Nora Adam Theresa Erler Mario Kallenbach Martin Kaltenpoth Grit Kunert Ian T.Baldwin Meredith C.Schuman Department of Molecular Ecology Max Planck Institute for Chemical Ecology Hans-Knoll-Straβe 8 07745 Jena Germany German Centre for Integrative Biodiversity Research (iDiv) Deutscher Platz5e 04103 Leipzig Germany max planck Research Group Insect Symbiosis Max Planck Institute for Chemical Ecology Hans-Knoll-Straβe 8 07745 Jena Germany Department of Biochemistry Max Planck Institute for Chemical Ecology Hans-Knoll-Straβe 8 07745 Jena Germany

Herbivore species sharing a host plant often compete. In this study, we show that host plant-mediated interaction between two insect herbivores-a generalist and a specialist-results in a sex ratio shift of the specialist＇s offspring. We studied demographic parameters of the specialist Tupiocoris notatus（Hemiptera： Miridae）when co-infesting the host plant Nicotiana attenuata（Solanaceae） with the generalist leafhopper Empoasca sp.（Hemiptera： Cicadellidae）. We show that the usually female-biased sex ratio of T. notatus shifts toward a higher male proportion in the offspring on plants coinfested by Empoasca sp. This sex ratio change did not occur after oviposition, nor is it due differential mortality of female and male nymphs. Based on pyrosequencing and PCR of bacterial 16 S rRNA amplicons, we concluded that sex ratio shifts were unlikely to be due to infection with Wolbachia or other known sex ratio-distorting endosymbionts. Finally, we used transgenic lines of *** to evaluate if the sex ratio shift could be mediated by changes in general or specialized host plant metabolites. We found that the sex ratio shift occurred on plants deficient in two cytokinin receptors（irCHK2/3）.Thus, cytokinin-regulated traits can alter the offspring sex ratio of the specialist ***.

关键词： Empoasca populations specialist offspring Hemiptera altered Nicotiana specialized Solanaceae transgenic

Learning causality and causality-related learning:some recent progress

在线全文

学校读者我要写书评

暂无评论

National Science Review 2018年第1期5卷 26-29页

作者： Kun Zhang Bernhard Scholkopf Peter Spirtes Clark Glymour Department of Philosophy Carnegie Mellon University max planck institute for Intelligent Systems

INTRODUCTION Causality is a fiundamental notion in science,and plays an important role in explanation,prediction,decision making and ***,with the rapidaccumulation of huge volumes of data,it is even more desirable to abstract causal knowledge from ***,such data are usually time series measured over a relatively long time period or ag-

关键词： Learning causality and causality-related learning:some recent progress FCI