http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
An unconventional role for miRNA: let-7 activates Toll-like receptor 7 and causes neurodegeneration
Lehmann, Sabrina M,Kr체ger, Christina,Park, Boyoun,Derkow, Katja,Rosenberger, Karen,Baumgart, Jan,Trimbuch, Thorsten,Eom, Gina,Hinz, Michael,Kaul, David,Habbel, Piet,K채lin, Roland,Franzoni, Eleonora,Ry Nature Publishing Group, a division of Macmillan P 2012 NATURE NEUROSCIENCE Vol.15 No.6
Activation of innate immune receptors by host-derived factors exacerbates CNS damage, but the identity of these factors remains elusive. We uncovered an unconventional role for the microRNA let-7, a highly abundant regulator of gene expression in the CNS, in which extracellular let-7 activates the RNA-sensing Toll-like receptor (TLR) 7 and induces neurodegeneration through neuronal TLR7. Cerebrospinal fluid (CSF) from individuals with Alzheimer's disease contains increased amounts of let-7b, and extracellular introduction of let-7b into the CSF of wild-type mice by intrathecal injection resulted in neurodegeneration. Mice lacking TLR7 were resistant to this neurodegenerative effect, but this susceptibility to let-7 was restored in neurons transfected with TLR7 by intrauterine electroporation of Tlr7<SUP>??/??</SUP> fetuses. Our results suggest that microRNAs can function as signaling molecules and identify TLR7 as an essential element in a pathway that contributes to the spread of CNS damage.
Lehmann, C. I.,Kim, Y.-H.,Preusse, P.,Chun, H.-Y.,Ern, M.,Kim, S.-Y. Copernicus GmbH 2012 Atmospheric measurement techniques Vol.5 No.7
<P><p><strong>Abstract.</strong> Convective gravity wave (GW) sources are spatially localized and emit at the same time waves with a wide spectrum of phase speeds. Any wave analysis therefore compromises between spectral and spatial resolution. Future satellite borne limb imagers will for a first time provide real 3-D volumes of observations. These volumes will be however limited which will impose further constraints on the analysis technique. In this study a three dimensional few-wave approach fitting sinusoidal waves to limited 3-D volumes is introduced. The method is applied to simulated GWs above typhoon Ewiniar and GW momentum flux is estimated from temperature fluctuations. Phase speed spectra as well as average profiles of positive, negative and net momentum fluxes are compared to momentum flux estimated by Fourier transform as well as spatial averaging of wind fluctuations. The results agree within 10-20%. The few-wave method can also reveal the spatial orientation of the GWs with respect to the source. The relevance of the results for different types of measurements as well as its applicability to model data is discussed.</p> </P>
An effective finite element approach for soil-structure analysis in the time-domain
Lehmann, L. Techno-Press 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.21 No.4
In this study, a complete analysis of soil-structure interaction problems is presented which includes a modelling of the near surrounding of the building (near-field) and a special description of the wave propagation process in larger distances (far-field). In order to reduce the computational effort which can be very high for time domain analysis of wave propagation problems, a special approach based on similarity transformation of the infinite domain on the near-field/far-field interface is applied for the wave radiation of the far-field. The near-field is discretised with standard Finite Elements, which also allows to introduce non-linear material behaviour. In this paper, a new approach to calculate the involved convolution integrals is presented. This approximation in time leads to a dramatically reduced computational effort for long simulation times, while the accuracy of the method is not affected. Finally, some benchmark examples are presented, which are compared to a coupled Finite Element/Boundary Element approach. The results are in excellent agreement with those of the coupled Finite Element/Boundary Element procedure, while the accuracy is not reduced. Furthermore, the presented approach is easy to incorporate in any Finite Element code, so the practical relevance is high.
O. Lehmann,N. K. Nguyen,J. Schuster,J. Roth-Stielow 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6
The “direct-torque-control” (DTC) is an alternative to the commonly used “field oriented control” (FOC) for the control of a PMSM. One advantage of the DTC is its inherent ability of sensorless control. However at standstill and low speed range the back-EMF based model has problems to detect the rotor position. The switching command synchronized evaluation (SCSE) calculates the rotor position using the current change during active voltage vectors. Realizations of the SCSE using the FOC are known, but the combination of the SCSE with a discrete-time DTC avoids problems with switching disturbances. The capability of the presented optimized DTC is proved with measurements on a test bench.
번역의 이론적 고찰과 한국문학 작품의 독일어 번역에 관한 특성
토비아스레만 ( Lehmann Tobias ) 한국독어독문학회 2012 獨逸文學 Vol.124 No.-
완벽한 번역이란 가능할까? 우리는 완벽한 번역을 위하여 노력하며, 또한 완벽한 번역을 위해 보다 정교하게 번역작업을 하고자 한다. 그러나 완벽한 번역은 하나의 꿈에 불과하다. 일반적으로 원본을 완벽하게 번역한다는 것은 결코 불가능하다. 심지어 새로운 글이 될 수도 있다. 발터 벤자민 (Die Aufgabe des Ubersetzers)과 폴 리코에 (Translation as Challenge and Source of Happiness)의 고찰을 통하여 살펴보면, 번역자에게는 원본에 쓰인 출발어와 그 언어가 배경으로 하는 사회, 문화와의 관계를 깊이 이해하는 것이 번역자에게 매우 중요한 과제라는 것을 알 수 있다. 그리고 번역자는 독자에게 번역의 내용을 특수한 감정이입으로 전달하여야 할 도전을 받는다. 그 감정이입에는 두 가지의 고려 요소가 있다. 첫째, 번역자는 출발어와 도착어를 완벽하게 구사할 수 있어야 한다. 둘째, 번역자는 독자의 희망과 기대 및 요구사항을 미리 파악하고 이를 번역에서 고려하여야 한다. 본 고에서는 이 문제들을 고찰하고자 하였으며, 이를 위하여 한국어를 독일어로 번역하는 문제와 관련하여, 이론적으로 뿐만아니라 실제적은 문제점들을 취급하고자 하였다. 폴 리코는 번역은 실제로 불가능하다고 했다. 왜냐하면 많은 언어와 그들이 지니고 있는 문화적 요소들은 너무나 서로 다르기 때문이다. 어휘와 수많은 문장구조를 한 언어에서 다른 언어로 옮길 경우 공통점을 찾기가 어렵기 때문에 번역상에서 힘든 문제점들이 자주 나타나는 것이다. 그런데 역사적으로, 사전이 존재하지 않은 경우에도 번역은 오래전부터 있어 왔다. 번역을 제외하고는 문화의 전달과 문화간의 소통을 위해서 다른 방법을 찾을 수 없다. 그러므로 한국 문화작품의 번역은, 한국 문화와 언어의 인정범위를 넓힐 수 있도록 돕기 위한 한국어의 세계화와 보편화의 도구라고 이해할 수 있을 것이다.
An effective finite element approach for soil-structure analysis in the time-domain
L. Lehmann 국제구조공학회 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.21 No.4
In this study, a complete analysis of soil-structure interaction problems is presented which includes a modelling of the near surrounding of the building (near-field) and a special description of the wave propagation process in larger distances (far-field). In order to reduce the computational effort which can be very high for time domain analysis of wave propagation problems, a special approach based on similarity transformation of the infinite domain on the near-field/far-field interface is applied for the wave radiation of the far-field. The near-field is discretised with standard Finite Elements, which also allows to introduce non-linear material behaviour. In this paper, a new approach to calculate the involved convolution integrals is presented. This approximation in time leads to a dramatically reduced computational effort for long simulation times, while the accuracy of the method is not affected. Finally, some benchmark examples are presented, which are compared to a coupled Finite Element/Boundary Element approach. The results are in excellent agreement with those of the coupled Finite Element/Boundary Element procedure, while the accuracy is not reduced. Furthermore, the presented approach is easy to incorporate in any Finite Element code, so the practical relevance is high.