568 research outputs found
Dual-Comb Swept Wavelength Interferometry
We demonstrate a hybrid swept wavelength interferometry-dual-comb spectroscopy system for fast broadband full-field measurements. Phase and amplitude retrieval is experimentally verified and compensation of laser sweep nonlinearity is demonstrated without external referencing
Microscopic mechanism for experimentally observed anomalous elasticity of DNA in 2D
By exploring a recent model [Palmeri, J., M. Manghi, and N. Destainville.
2007. Phys. Rev. Lett. 99:088103] where DNA bending elasticity, described by
the wormlike chain model, is coupled to base-pair denaturation, we demonstrate
that small denaturation bubbles lead to anomalies in the flexibility of DNA at
the nanometric scale, when confined in two dimensions (2D), as reported in
atomic force microscopy (AFM) experiments [Wiggins, P. A., et al. 2006. Nature
Nanotech. 1:137-141]. Our model yields very good fits to experimental data and
quantitative predictions that can be tested experimentally. Although such
anomalies exist when DNA fluctuates freely in three dimensions (3D), they are
too weak to be detected. Interactions between bases in the helical
double-stranded DNA are modified by electrostatic adsorption on a 2D substrate,
which facilitates local denaturation. This work reconciles the apparent
discrepancy between observed 2D and 3D DNA elastic properties and points out
that conclusions about the 3D properties of DNA (and its companion proteins and
enzymes) do not directly follow from 2D experiments by AFM.Comment: To appear in Biophys. J. 8 pages, supplementary information included
(7 pages
Digital Twin of a Network and Operating Environment Using Augmented Reality
We demonstrate the digital twin of a network, network elements, and operating
environment using machine learning. We achieve network card failure
localization and remote collaboration over 86 km of fiber using augmented
reality
Real-Time Monitoring of Cable Break in a Live Fiber Network using a Coherent Transceiver Prototype
We monitor a 524km live network link using an FPGA-based sensing-capable
coherent transceiver prototype during a human-caused cable break. Post-analysis
of polarization data reveals minute-level potential warning precursors and
baseline-exceeding changes directly preceding the break.Comment: 3 page
Transmission of 273.6 Tb/s Over 1001 km of 15-Mode Multi-Mode Fiber Using C-Band Only 16-QAM Signals
In recent years, space-division multiplexing (SDM) has been proposed and investigated as a technique to increase the per-fiber capacity in order to cope with the ever-increasing demand for capacity in optical transmission networks. Considering the various SDM architectures proposed, multi-mode fibers potentially allow for the highest spatial channel density, but current demonstrations have been limited to mostly short-distance high-mode count or long-distance low-mode count transmission. In this work, we transmit 15 modes × 184 wavelength channels × 24.5 GBd PDM-16-QAM signals, spanning the full C-band, over 1001 km of 15-mode multi-mode fiber. The resulting net data rate of 273.6 Tb/s is the highest reported data rate in long-distance multi-mode fiber transmission and results in a record capacity-distance product of 273.9 Pb/s · km for multi-mode transmission. This was achieved by using mode multiplexers with low mode-dependent loss (MDL) and insertion loss, as well as a 15-mode fiber optimized for a low differential mode delay (DMD) transmission regime
Alignment of Free-Space Coupling of Few-Mode Fibre to Multi-Mode Fibre using Digital Holography
Off-axis digital holography is used to align a few-mode fiber to a multi-mode fiber in a free-space optical setup. Alignment based on power coupling measurements alone cannot guarantee low mode-dependent loss. The proposed alignment method enables reliable fiber coupling with low mode-dependent loss and crosstalk
Odontoma composto em região anterior de mandíbula associado a canino retido: relato de caso
Odontomas são os tumores odontogênicos com a maior incidência, geralmente são assintomáticos e o diagnóstico é realizado através de exame físico e imaginológico, o qual muitas vezes é solicitado para investigar a causa de atrasos na erupção dentária. O presente trabalho tem por objetivo relatar um caso clínico de odontoma composto em região anterior de mandíbula associado a canino retido, enfatizando a técnica cirúrgica e a importância do diagnóstico precoce. Paciente do gênero feminino, 37 anos, leucoderma, apresentou em radiografia panorâmica de rotina a transmigração do elemento dentário 33, que se encontrava retido em região de mento, com lesões mistas adjacentes. A abordagem cirúrgica para remoção das lesões e extração do elemento dental retido foi realizada sob anestesia local a nível ambulatorial, seguida de exame histopatológico, o qual confirmou o diagnóstico de odontoma composto. A associação entre retardo de erupção dentária e a presença de odontomas torna importante a realização de radiografias ou tomografias odontológicas para investigação dos sinais e sintomas clínicos, visto que, através de um diagnóstico precoce ainda na dentição decídua, é possível intervir para evitar falhas na erupção de elementos dentários permanentes com um prognóstico cirúrgico mais favorável
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