Download or read book Microscopie Non Lin aire written by Thierry Boulesteix and published by Omniscriptum. This book was released on 2011 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Depuis 1990, la microscopie non linéaire de fluorescence excitée à deux photons ou de génération de second harmonique a insufflé un nouvel élan à la microscopie optique. Il est possible de réaliser de l'imagerie fonctionnelle tridimensionnelle de tissus épais vivants ou de cellule. Le contraste provient soit de colorants optimisés pour l'imagerie non linéaire, soit de protéines naturellement présentes dans les tissus comme l'élastine ou le collagène. Ce travail mené au sein du Laboratoire d'Optique et Biosciences à l'École polytechnique est enrichi de nombreuses images obtenues par combinaison des signaux de fluorescence à deux photons et de second harmonique. Il montre tout l'intérèt de cette technique face à l'histologie classique et permet de mettre en évidence des effets du lindane (un insecticide très répandu) sur le système cardio- circulatoire du Rat. Il a également été possible de mener une étude nanotoxinologique à partir du signal de second harmonique des filaments de myosine. Il s'agit d'une mesure de contracture au repos de cellules atriales de grenouille soumises à une toxine (la saxitoxine), avec une précision de 20 nm.
Download or read book Microscopie par g n ration du second harmonique written by Laurent Moreaux and published by . This book was released on 2002 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: By far the most well known form of non-linear microscopy is based on two-photon excited fluorescence (TPEF), which bas now become a laboratory standard for biological imaging. A lesser known form of this microscopy, however, was used several years prior to the invention of TPEF microscopy, based on the generation of second harmonic light either from surfaces or from endogenous tissue structures. Because of difficulties in signal, second-harmonic generation (SHG) microscopy has gone by relatively unnoticed until only very recently. This work present a detailed experimental and theoretical analysis of the generation of second-harmonic radiation from biological membranes labeled with exogenous markers. We demonstrate that simultaneous second-harmonic generation and two-photon excited fluorescence can be used to image biological membranes labeled with properly designed chromophore. Moreover, we show that spatial resolutions provided by SHG and TPEF microscopies are commensurate, meaning that the two contrast modes can very often be conveniently derived from the same instrument. Based on phased-array antennas model, we derive expressions for the SHG radiation power, angular distribution and polarization dependence in the cases of ideal or non-ideal molecular alignment in the membrane. We define an SHG cross-section similar to that used in two-photon excited fluorescence to allow direct comparison. Despite their similarities, however, SHG and TPEF are fundamentally different phenomena. The first is coherent whereas the second is not. We demonstrate, moreover, that this basic difference provides a unique window into molecular spatial organization which is inaccessible to fluorescence. At least, we present a screening technique to quantify and ascertain the nature of the second-harmonic generation response of chromophores to a trans-membrane electric field. These results are specifically directed to the optimisation of membrane potential response in SHG microscopy.
Download or read book L optique dans les instruments Applications la m decine et la biologie written by GOURE Jean-Pierre and published by Lavoisier. This book was released on 2013-04-01 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les instruments jouent un rôle primordial dans l’avancée scientifique et technologique. Les ouvrages de cette mini-série consacrée à l’optique dans les instruments ont pour but de montrer que l’optique et les composants optiques constituent souvent la partie essentielle autour de laquelle interviennent l’électronique, la mécanique et l’informatique. Le premier tome a décrit les bases nécessaires à la compréhension des phénomènes physiques mis en jeu. Ce second tome a pour but d’illustrer par divers exemples le rôle fondamental de l’optique dans l’instrumentation destinée à la biologie et à la médecine. Sont développés quelques instruments utilisés en routine pour l’analyse et la caractérisation, des instruments de très haute complexité permettant aux chercheurs d’avoir accès à des mesures ultra précises ainsi que des technologies prometteuses actuellement en développement. Enfin ces exemples permettront de voir l’impact des lasers non seulement dans l’instrumentation mais aussi dans les soins médicaux depuis l’ophtalmologie jusqu’à la chirurgie et le traitement de nombreuses maladies.
Download or read book Microscopie par g n ration de troisi me harmonique appliqu e la biologie written by Delphine Debarre and published by . This book was released on 2006 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Routledge Dictionnaire Technique Anglais written by Yves Arden and published by Psychology Press. This book was released on 1994 with total page 866 pages. Available in PDF, EPUB and Kindle. Book excerpt: The French-English volume of this highly acclaimed set consists of some 100,000 keywords in both French and English, drawn from the whole range of modern applied science and technical terminology. Covers over 70 subject areas, from engineering and chemistry to packaging, transportation, data processing and much more.
Download or read book 10th International Congress on X ray Optics and Microanalysis written by and published by . This book was released on 1984 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal de physique written by and published by . This book was released on 2006 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book R ponse non lin aire locale de monocouches mol culaires ordonn es et effets d exaltations sur les structures m talliques granulaires sond s par microscopie 2 photons written by Christelle Chantal Ginette Anceau and published by . This book was released on 2002 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: La microscopie à 2-photons est aujourd'hui largement utilisée en biologie pour améliorer la profondeur de pénétration dans les tissus biologiques et limiter la photo-destruction. La résolution spatiale proche de celle de la microscopie confocale et l'étude temporelle des échantillons en fait une technique de choix dans la compréhension de la physique sub-microscopique.Ce mémoire présente la mise en place d'un microscope sous excitation deux photons. La résolution spatiale (environ 400 nanomètres), l'apport d'une détection spectrale et d'une analyse en polarisation a permis l'étude de systèmes moléculaires ordonnés et de structures métalliques désordonnées par la génération de second harmonique et de fluorescence à deux photons.Les échantillons étudiés sont des monocouches moléculaires déposées par la méthode de Langmuir-Blodgett. L'étude en polarisation du signal émis a permis d'accéder à des informations locales sur la symétrie de l'ordre moléculaire et la présence de domaines d'orientations spécifiques. Dans une seconde partie, nous avons étudié des films d'or granulaire générant des pics d'exaltation linéaire du champ électromagnétique localisés à la surface de l'échantillon dans des zones nanométriques. La génération de second harmonique de surface a montré elle aussi une localisation spatiale d'exaltations non-linéaires. Leurs répartitions et leurs amplitudes dépendent fortement de la granularité des échantillons et de l'état de polarisation incident. Ces exaltations mettent en évidence la sensibilité de cette technique à la morphologie d'effets de surface à une échelle sub-micronique.L'étude d'une monocouche de molécules déposée à la surface de telles structures a montré une exaltation de la réponse non-linéaire des molécules. Cependant, le seuil de dommage moléculaire est à ce stade un facteur limitant. Des études du temps de vie de fluorescence montrent, de plus, des interactions de type chimiques métal/molécules. Des solutions sont envisagées et discutées
Download or read book Microscopie multiphotonique appliqu e la biologie written by Aymeric Leray and published by . This book was released on 2005 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les techniques de microscopie multiphotonique s'imposent de plus en plus en biologie. Ces techniques permettent d'accéder à une profondeur d'imagerie inégalée dans les tissus vivants tout en les préservant des effets de photo-toxicité. Cette profondeur d'imagerie dépend en outre à la fois de la sensibilité des marqueurs (à l'origine de la fluorescence ou de la génération de seconde harmonique) et des performances optiques du microscope. Le travail présenté dans ce mémoire s'articule autour de ces deux problématiques. Dans une première partie, nous caractérisons de nouveaux marqueurs membranaires du point de vue de leurs propriétés optiques non linéaires et de leur organisation au sein de phospholipides. Nous présentons ensuite le développement d'un microscope multiphotonique prototype dont les performances en terme de profondeur d'imagerie notamment sont étudiées expérimentalement et à partir de simulations Monte Carlo.
Download or read book Physics Briefs written by and published by . This book was released on 1979 with total page 888 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Routledge French Technical Dictionary Dictionnaire technique anglais written by Yves Arden and published by Routledge. This book was released on 2013-01-11 with total page 866 pages. Available in PDF, EPUB and Kindle. Book excerpt: The French-English volume of this highly acclaimed set consists of some 100,000 keywords in both French and English, drawn from the whole range of modern applied science and technical terminology. Covers over 70 subject areas, from engineering and chemistry to packaging, transportation, data processing and much more.
Download or read book Music A Mathematical Offering written by Dave Benson and published by Cambridge University Press. This book was released on 2007 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores the interaction between music and mathematics including harmony, symmetry, digital music and perception of sound.
Download or read book Lenses and Waves written by Fokko Jan Dijksterhuis and published by Springer Science & Business Media. This book was released on 2006-01-20 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1690, Christiaan Huygens (1629-1695) published Traité de la Lumière, containing his renowned wave theory of light. It is considered a landmark in seventeenth-century science, for the way Huygens mathematized the corpuscular nature of light and his probabilistic conception of natural knowledge. This book discusses the development of Huygens' wave theory, reconstructing the winding road that eventually led to Traité de la Lumière. For the first time, the full range of manuscript sources is taken into account. In addition, the development of Huygens' thinking on the nature of light is put in the context of his optics as a whole, which was dominated by his lifelong pursuit of theoretical and practical dioptrics. In so doing, this book offers the first account of the development of Huygens' mathematical analysis of lenses and telescopes and its significance for the origin of the wave theory of light. As Huygens applied his mathematical proficiency to practical issues pertaining to telescopes – including trying to design a perfect telescope by means of mathematical theory – his dioptrics is significant for our understanding of seventeenth-century relations between theory and practice. With this full account of Huygens' optics, this book sheds new light on the history of seventeenth-century optics and the rise of the new mathematical sciences, as well as Huygens' oeuvre as a whole. Students of the history of optics, of early mathematical physics, and the Scientific Revolution, will find this book enlightening.
Download or read book Applied Nonlinear Optics written by Frits Zernike and published by Courier Corporation. This book was released on 2006-01-01 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Directed toward physicists and engineers interested in the device applications enabled by nonlinear optics, this text is suitable for advanced undergraduates and graduate students. Its content is presented entirely on a classical basis and requires only an elementary knowledge of quantum mechanics. The authors demonstrate how real laboratory situations can diverge from ideal theory, acquainting readers with the kinds of problems common to construction of a nonlinear device. They also offer a detailed discussion of the practical problems and characteristics of nonlinear materials, as well as the selection procedures necessary to ensure the use of good material. Their treatment begins with an introduction to the theories of linear and nonlinear optics, along with the basic ideas behind them. Succeeding chapters explore phase matching and nonlinear materials, followed by detailed treatments of second-harmonic generation, parametric up-conversion, and optical parametric amplification and oscillation. Appendixes offer a comprehensive list of materials and their properties; the text concludes with references and an index.
Download or read book Music and Science in the Age of Galileo written by V. Coelho and published by Springer Science & Business Media. This book was released on 1992-11-30 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: A collection of essays exploring the relations between music and the scientific culture of Galileo's time. It takes a broad historical approach towards understanding such topics as the role of music in Galileo's experiments and in the scientific revolution
Download or read book Hydrogeology written by Alain Dassargues and published by CRC Press. This book was released on 2018-09-03 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text combines the science and engineering of hydrogeology in an accessible, innovative style. As well as providing physical descriptions and characterisations of hydrogeological processes, it also sets out the corresponding mathematical equations for groundwater flow and solute/heat transport calculations. And, within this, the methodological and conceptual aspects for flow and contaminant transport modelling are discussed in detail. This comprehensive analysis forms the ideal textbook for graduate and undergraduate students interested in groundwater resources and engineering, and indeed its analyses can apply to researchers and professionals involved in the area.
Download or read book The Harmony of Illusions written by Allan Young and published by Princeton University Press. This book was released on 1997-10-27 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: As far back as we know, there have been individuals incapacitated by memories that have filled them with sadness and remorse, fright and horror, or a sense of irreparable loss. Only recently, however, have people tormented with such recollections been diagnosed as suffering from "post-traumatic stress disorder." Here Allan Young traces this malady, particularly as it is suffered by Vietnam veterans, to its beginnings in the emergence of ideas about the unconscious mind and to earlier manifestations of traumatic memory like shell shock or traumatic hysteria. In Young's view, PTSD is not a timeless or universal phenomenon newly discovered. Rather, it is a "harmony of illusions," a cultural product gradually put together by the practices, technologies, and narratives with which it is diagnosed, studied, and treated and by the various interests, institutions, and moral arguments mobilizing these efforts. This book is part history and part ethnography, and it includes a detailed account of everyday life in the treatment of Vietnam veterans with PTSD. To illustrate his points, Young presents a number of fascinating transcripts of the group therapy and diagnostic sessions that he observed firsthand over a period of two years. Through his comments and the transcripts themselves, the reader becomes familiar with the individual hospital personnel and clients and their struggle to make sense of life after a tragic war. One observes that everyone on the unit is heavily invested in the PTSD diagnosis: boundaries between therapist and patient are as unclear as were the distinctions between victim and victimizer in the jungles of Southeast Asia.
