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香蕉为什么是弯的孩子们经常问的100个有趣的问题及其答案

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Bringing epigenetics into the diagnostics of the andrology laboratory： challenges and perspectives

2002年

作者：（德）马蒂亚斯·米勒-米夏埃利斯（Matthias jorg muller-Michaelis）王浣倩译

本书主要内容包括：人生出来就有两个耳朵；从恐龙到蚂蚁——大大小小的动物；沿着太空飞船行驶的轨道；各种各样的导线和点亮的灯泡等。

ISBN: (纸本)7501157049

本书主要内容包括：人生出来就有两个耳朵；从恐龙到蚂蚁——大大小小的动物；沿着太空飞船行驶的轨道；各种各样的导线和点亮的灯泡等。

关键词：科学知识

来源：汇雅图书（南通市图书馆... 评论

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Asian Journal of Andrology 2014年第5期16卷 669-674,I0006页

作者： Ruth Klaver jorg Gromoll Centre of Reproductive Medicine and Andrology University Clinics of MOnster MOnster Germany

Recent studies have shown significant associations of aberrant DNA methylation in spermatozoa with idiopathic male infertility, increased frequency of spontaneous abortions and imprinting disorders. Thus, the analysis of DNA methylation of specific genes in spermatozoa has the potential to become a new valuable diagnostic marker in clinical andrology. This perspective article discusses the current state and value of DNA methylation analysis in the diagnostic setup of infertile men and outlines challenges and perspectives. It highlights the potential of DNA methylation in andrological diagnostics and its putative benefit in the examination of hitherto idiopathic infertile patients is described.

关键词： DNA methylation male infertility spermatogenesis

Transfer of CrylAc and Cry2Ab proteins from genetically engineered Bt cotton to herbivores and predators

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Insect Science 2018年第5期25卷 823-832页

作者： Michael Meissle jorg Romeis Agroscope Research Division Agroecology and Environment Zurich Switzerland

With the cukivation of Bt cotton, the produced insecticidal Cry proteins are ingested by herbivores and potentially transferred along the food chain to natural enemies, such as predators. In laboratory experiments with Bollgard II cotton, concentrations of CrylAc and Cry2Ab were measured in Lepidoptera larvae （Spodoptera littoralis, Hello- this virescens）, plant bugs （Euschistus heros）, aphids （Aphis gossypii）, whiteflies （Bemisia tabaci）, thrips （ Thrips tabaci, Frankliniella occidentalis）, and spider mites （Tetranychus urticae）. Tritrophic experiments were conducted with caterpillars ofS. littoralis as prey and larvae of ladybird beetles （Harmonia axyridis, Adalia bipunctata） and lacewings （Chrysop- erla carnea） as predators. Immunological measurements （ELISA） indicated that herbivores feeding on Bt cotton contained 5%-50% of the Bt protein concentrations in leaves except whiteflies and aphids, which contained no or only traces of Bt protein, and spider mites, which contained 7 times more Cry 1Ac than leaves. Similarly, predators contained 1%-30% of the Cry protein concentration in prey. For the nontarget risk assessment, this indicates that Bt protein concentrations decrease considerably from one trophic level to the next in the food web, except for spider mites that contain Bt protein concentrations higher than those measured in the leaves. Exposure of phloem sucking hemipterans is negligible.

关键词： arthropod food web Bacillus thuringiensis Bt cotton Cry protein ELISA transgenic plants

Fundamental influences of particles on stirred and unstirred venting processes of foaming systems

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Frontiers of Chemical Science and Engineering 2014年第2期8卷 141-148页

作者： Henrik LEIMEISTER jorg STEINBACH Department of Process Engineering Technische Universitat Berlin Strage des 17. Juni 135 10623 Berlin Germany

Venting is the common safety measure to protect plant equipment against excessive overpressure. So far, scenarios in which particles were part of the system and should have been accounted for did ignore their presence; the scenarios were treated like a two-phase system. Current research shows that particles can have a major influence on the venting behaviour. Experimental results indicate that particles affect level swell and relief flow especially of foamy systems. Based on those results four different layers of influence of the particle have been identified and are presented in a first model. Based on this model recommendations for the development of new and more complex models are given.

关键词： venting multi-phase

The contribution of small leaks in a baghouse filter to dust emission in the PM2.s range-A system approach

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Particuology 2017年第1期15卷 40-52页

作者： Oliver Kurtz jorg Meyer Gerhard Kasper Institut for Mechanische Verfahrenstechnik und Mechanik Karlsruhe Institute of Technology 76131 Karlsruhe Germany Freudenberg Filtration Technologies 69465 WeinheimGermany.

The contribution of leakage in a baghouse filter （defined as a short circuit between the upstream and downstream sides of the filter） to the emission of fine particles is quantified in comparison to other dust emission sources, and the influence of key operating variables on overall system response is analyzed. The study was conducted on a well-maintained pilot-scale filter unit （9 bags of 500 g/m^2 calendered polyester needle felt; total surface area 4.2 m^2） operated in Ap-controlled mode over a range of pulsing intensities, with two types of test dust （one free-flowing and the other cohesive） at inlet concentrations of 10 and 30 g/m^3. Leaks included single holes between 0.5 and 4 mm diameter, intentionally placed in either the plenum plate or one of the filter bags, as well as seamlines from bag confectioning. Emissions were sep- arated by source into a transient contribution due to dust penetration through the filter bags after each cleaning pulse, and a continuous contribution from leaks. This separation was based on a novel method of data processing that relies on time-resolved concentration measurements with a specially calibrated optical particle counter. Tiny leaks on the order of 1 mm generated the same emission level as all the bags combined, and dominated continuous emissions. The equivalent leak cross section （leakage = media emission） was about 1 ppm of the total installed filter surface, independent of upstream dust concentra- tion. Leakage through open seamlines amounted to 75% of media emissions in case of free-flowing test dust. Leakage was restricted to aerodynamic diameters less than ~5 μm （roughly the PM2.s mass frac- tion）. For comparison, time-averaged mass penetration through conventional needle-felt media ranged from about 10^-5 to 10^-6, depending on cohesiveness of the particle material and pulse cleaning intensity, giving emission levels between about 0.02 and 0.2 mg/m^3 at the reference concentration of 10 R/m^2.

关键词： Air filtration Baghouse Pulse-cleaned filters Leaks PM2.5 Dust emission

Numerical analysis of hydroabrasion in a hydrocyclone

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Petroleum Science 2016年第2期13卷 304-319页

作者： Mehdi Azimian Hans-jorg Bart Department of Mechanical and Process Engineering University of Kaiserslautern 67663 Kaiserslautern Germany

The velocity profiles and separation efficiency curves of a hydrocyclone were predicted by an Euler-Euler approach using a computational fluid dynamics tool ANSYS-CFX 14.5. The Euler-Euler approach is capable of considering the particle-particle interactions and is appropriate for highly laden liquid-solid mixtures. Pre- dicted results were compared and validated with experi- mental results and showed a considerably good agreement. An increase in the particle cut size with increasing solid concentration of the inlet mixture flow was observed and discussed. In addition to this, the erosion on hydrocyclone walls constructed from stainless steel 410, eroded by sand particles （mainly SiOz）, was predicted with the Euler-La- grange approach. In this approach, the abrasive solid particles were traced in a Lagrangian reference frame as discrete particles. The increases in the input flow velocity, solid concentration, and the particle size have increased the erosion at the upper part of the cylindrical body of the hydrocyclone, where the tangential inlet flow enters the hydrocyclone. The erosion density in the area between the cylindrical to conical body area, in comparison to other parts of the hydrocyclone, also increased considerably. Moreover, it was observed that an increase in the particle shape factor from 0.1 to 1.0 leads to a decrease of almost 70 % in the average erosion density of the hydrocyclone wall surfaces.

关键词： Hydrocyclone Computational fluiddynamicS (CFD) Separation efficiency - Erosion rateErosion impact parameters

Prey-mediated effects of mCry51Aa2-producing cotton on the predatory nontarget bug Orius majusculus(Reuter)

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Insect Science 2023年第4期30卷 1191-1206页

作者： Anja Boss jorg Romeis Michael Meissle Research Division Agroecology and Environment AgroscopeZurichSwitzerland Institute of Plant Sciences University of BernBernSwitzerland

Genetically engineered(GE)cotton,MON 88702,is protected against cer-tain sucking pests,such as plant bugs and thrips,by producing mCry51Aa2,a mod-ified protein from Bacillus thuringiensis(Bt).Predatory pirate bugs(Orius spp.),natural enemies contributing to biological pest control,are also sensitive to the insecti-cidal protein when exposed continuously to high *** evaluated effects of MON 88702 on Orius majusculus when fed prey types with different mCry51Aa2 *** neonates were provided exclusively Tetranychus urticae spider mites reared on MON 88702(high mCry51Aa2 content),adverse effects on predator survival and de-velopment were confirmed,compared with specimens fed prey from near-isogenic non-Bt *** fed a mixture of *** and Ephestia kuehniella eggs(mCry51Aa2-free),predator life table parameters were similar to the treatment where eggs were fed *** mCry51Aa2-containing spider mites were provided for a limited time at the beginning or the end of juvenile development,effects were less *** pirate bug nymphs showed similar consumption rates for prey from Bt and non-Bt cotton,choice experiments revealed a preference for *** eggs over spider *** larvae(Spodoptera littoralis,high mCry51Aa2 content)or cotton aphids(Aphis gossypii,mCry51Aa2-free)reared on MON 88702 as alternative prey did not result in adverse ef-fects on *** study suggests limited risk of mCry51Aa2-producing cotton for ***,because its sensitivity for the Bt protein is relatively low and its natural food consists of diverse prey species with varying concentrations of Bt protein.

关键词： ecosystem services environmental risk assessment enzyme-linked im-munosorbent assay(ELISA) genetically modified crops Heteroptera Anthocoridae tritrophic interactions

Studies of fiber-matrix debonding

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Frontiers of Structural and Civil Engineering 2015年第4期9卷 448-456页

作者： Navneet DRONAMRAJU Johannes SOLASS jorg HILDEBRAND Simulation und Experiment Bauhaus-Universitdt Weimar Weimar 99423 Germany

In this paper, the debonding of a single fiber-matrix system of carbon fiber reinforced composite (CFRP) AS4/Epson 828 material is studied using Cohesive Zone Model (CZM). The effect of parameters namely, maximum tangential contact stress, tangential slip distance and artificial damping coefficient on the debonding length at the interface of the fiber-matrix is analyzed. Contact elements used in the CZM are coupled based on a bilinear stress-strain curve. Load is applied on the matrix, tangential to the interface. Hence, debonding is observed primarily in Mode II. Wide range of values are considered to study the inter-dependency of the parameters and its effect on debonding length. Out of the three parameters mentioned, artificial damping coefficient and tangential slip distance significantly affect debonding length. A thorough investigation is recommended for case wise interface debonding analysis, to estimate the optimal parametric values while using CZM.

关键词： single fibre cohesive zone model interface debonding carbon fiber reinforced composite (CFRP)

Colorful Insights： Advances in Imaging Drive Nove 3reakthroughs in Ca^2＋ Signaling

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Molecular Plant 2015年第3期8卷 352-355页

作者： Alex Costa jorg Kudla Dipartimento di Bioacienze Università degli Studi di Milano Via G. Celoria 26 20133 Milan Italy Istituto di Biofisica Consiglio Nazionale delle Ricerche Via G. Celoria 26 20133 Milan Italy Institut für Biologie und Biotechnologie der Pflanzen Universitat Münster Schlossplatz 4 48149 Münster Germany

In plants, Ca^2＋ signals occur in response to both environmental and developmental stimuli. These signals involve increases in [Ca^2＋] in compartments such as the cytoplasm, nucleus, and mitochondria, and can display multiple shapes ranging from sin- gle transients to repetitive Ca^2＋ oscillations. Generation and shaping of stimulus specific [Ca^2＋] signatures depends on Ca^2＋ influxes and effluxes occurring at both the plasma membrane （PM） and membranes of the different subcellular compartments.

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