Andrea Callegari

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We used near-edge x-ray absorption fine structure (NEXAFS) spectroscopy to link the orientational bond order at three carbonaceous surfaces-rubbed polyimide, ion beam-irradiated polyimide, and ion beam-irradiated diamondlike carbon films-with the direction of liquid crystal (LC) alignment on these surfaces. We show that, in general, LC alignment can be(More)
The eigenstate resolved, near-infrared spectrum of methylamine, has been measured at 5 MHz CH 3 NH 2 , resolution in the region near 6615 cm~1 using a molecular-beam laser spectrometer with optothermal detection. Part of the spectrum of the NH (symmetric stretch Ðrst overtone) has been assigned by applying 2l 1 a millimeter-waveÈinfrared double resonance(More)
The technique used to align liquid crystals-rubbing the surface of a substrate on which a liquid crystal is subsequently deposited-has been perfected by the multibillion-dollar liquid-crystal display industry. However, it is widely recognized that a non-contact alignment technique would be highly desirable for future generations of large, high-resolution(More)
The intensity of water absorption in the region of the solar spectrum plays a dominant role in atmospheric energy balance and hence strongly influences climate. Significant controversy exists over how to model this absorption accurately. We report dipole moment measurements of highly vibrationally excited water, which provide stringent tests of intensities(More)
We have developed a simple and accurate method for calibrating the amplitude of vibration of quartz tuning fork sensors commonly used in atomic force- and near field optical-microscopy. Unlike interferometric methods, which require a complex optical setup, the method we present requires only a simple measurement of the electro-mechanical properties of the(More)
We measured the ultrafast response of triangular silver nanoparticles upon femtosecond excitation of their plasmon resonance. After a fast electron relaxation, the signature of a bimodal mechanical vibration of the particle is apparent as a spectral modulation. We identify the two lowest frequency, totally symmetric vibrations of the particle as responsible(More)
We report here a measurement of electric dipole moments in highly vibrationally excited HDO molecules. We use photofragment yield detected quantum beat spectroscopy to determine electric field induced splittings of the J=1 rotational levels of HDO excited with 4, 5, and 8 quanta of vibration in the OH stretching mode. The splittings allow us to deduce mua(More)
We present here the analysis of experimental Stark effect measurements made using photofragment quantum beat spectroscopy on the |4,0(-)>, |5,0(-)>, |8,0(+)> and |4,0(-)>|2> vibrational states of H(2)O [ Callegari , A. ; et al. Science 2002 , 297 , 993.]. To link the measured Stark coefficients with the dipole surface, we analyze our results using a coupled(More)
Ligand signature in the membrane dynamics of single TrkA receptor molecules L. Marchetti , A. Callegari , S. Luin, G. Signore, A. Viegi, F. Beltram and A. Cattaneo 1 NEST, Scuola Normale Superiore and Istituto Nanoscienze – CNR, Piazza San Silvestro 12, I56126 Pisa, Italy. 2 BioSNS Laboratory, Scuola Normale Superiore, c/o Istituto di Neuroscienze del CNR,(More)
Mitotic bookmarking transcription factors remain bound to chromosomes during mitosis and were proposed to regulate phenotypic maintenance of stem and progenitor cells at the mitosis-to-G1 (M-G1) transition. However, mitotic bookmarking remains largely unexplored in most stem cell types, and its functional relevance for cell fate decisions remains unclear.(More)
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