3,992 research outputs found
An Integrated Platform for Differential Electrochemical and ISFET Sensing
A fully-integrated differential biosensing platform on CMOS is presented for miniaturized enzyme-based electrochemical sensing. It enables sensor background current elimination and consists of a differential sensor array and a differential readout IC (DiRIC). The sensor array includes a four-electrode sensor for amperometric electrochemical sensing, as well as a differential ISFET-based pH sensor to calibrate the biosensors. The ISFET is biased in weak inversion and co-designed with DiRIC to enable pH measurements from 1 to 14 with resolution of 0.1 pH. DiRIC enables differential current measurement in the range of ¿¿100 ¿¿A with more than 120dB dynamic range
PPLN Waveguide for Quantum Communication
We report on energy-time and time-bin entangled photon-pair sources based on
a periodically poled lithium niobate (PPLN) waveguide. Degenerate twin photons
at 1314 nm wavelength are created by spontaneous parametric down-conversion and
coupled into standard telecom fibers. Our PPLN waveguide features a very high
conversion efficiency of about 10^(-6), roughly 4 orders of magnitude more than
that obtained employing bulk crystals. Even if using low power laser diodes,
this engenders a significant probability for creating two pairs at a time - an
important advantage for some quantum communication protocols. We point out a
simple means to characterize the pair creation probability in case of a pulsed
pump. To investigate the quality of the entangled states, we perform
photon-pair interference experiments, leading to visibilities of 97% for the
case of energy-time entanglement and of 84% for the case of time-bin
entanglement. Although the last figure must still be improved, these tests
demonstrate the high potential of PPLN waveguide based sources to become a key
element for future quantum communication schemesComment: 11 pages, 9 figures, submitted to the European Physical Journal D
(special issue of the Quick conference
RAPD markers in wild and cultivated Vitis vinifera
Some Vitis vinifera cultivars and V. vinifera ssp. silvestris individuals have been subjected to the RAPD analysis in order to estimate the genetic diversity existing within this germplasm. 44 decamer primers of arbitrary sequence have been used for PCR and reproducible band profiles have been obtained. The distribution of the individualized polymorphic DNA markers has not turned out to be different in a remarkable way between cultivated and wild grapevines but this RAPD approach provides for some characteristics useful to analyze genetic relationships even within the Vitis vinifera species
Nature-Inspired Interconnects for Self-Assembled Large-Scale Network-on-Chip Designs
Future nano-scale electronics built up from an Avogadro number of components
needs efficient, highly scalable, and robust means of communication in order to
be competitive with traditional silicon approaches. In recent years, the
Networks-on-Chip (NoC) paradigm emerged as a promising solution to interconnect
challenges in silicon-based electronics. Current NoC architectures are either
highly regular or fully customized, both of which represent implausible
assumptions for emerging bottom-up self-assembled molecular electronics that
are generally assumed to have a high degree of irregularity and imperfection.
Here, we pragmatically and experimentally investigate important design
trade-offs and properties of an irregular, abstract, yet physically plausible
3D small-world interconnect fabric that is inspired by modern network-on-chip
paradigms. We vary the framework's key parameters, such as the connectivity,
the number of switch nodes, the distribution of long- versus short-range
connections, and measure the network's relevant communication characteristics.
We further explore the robustness against link failures and the ability and
efficiency to solve a simple toy problem, the synchronization task. The results
confirm that (1) computation in irregular assemblies is a promising and
disruptive computing paradigm for self-assembled nano-scale electronics and (2)
that 3D small-world interconnect fabrics with a power-law decaying distribution
of shortcut lengths are physically plausible and have major advantages over
local 2D and 3D regular topologies
Orbiting Resonances and Bound States in Molecular Scattering
A family of orbiting resonances in molecular scattering is globally described
by using a single pole moving in the complex angular momentum plane. The
extrapolation of this pole at negative energies gives the location of the bound
states. Then a single pole trajectory, that connects a rotational band of bound
states and orbiting resonances, is obtained. These complex angular momentum
singularities are derived through a geometrical theory of the orbiting. The
downward crossing of the phase-shifts through pi/2, due to the repulsive region
of the molecular potential, is estimated by using a simple hard-core model.
Some remarks about the difference between diffracted rays and orbiting are also
given.Comment: 18 pages, 3 figures, to appear in Physical Review
Synthesis of 5-substituted 7,9-dihydro-8H-[1,3]dioxolo[4,5-h][2,3]benzodiazepin-8-ones as anticonvulsant agents
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O uso de drogas e o recolhimento compulsório de crianças e adolescentes no Rio de Janeiro
O estudo de crianças e adolescentes em situação de rua que fazem uso de drogas é um tema causador de grandes debates e polêmicas não só entre os pesquisadores da área, mas perante a sociedade também. Temos ciência que a questão do consumo de drogas está atrelada a uma perspectiva histórica, levando em conta os processos que transformaram os hábitos da sociedade. Neste sentido, é importante ressaltar que as políticas públicas voltadas para esse público alvo ainda não foram e ainda não são eficazes o suficiente para dar conta da crescente demanda. Em torno dessa discussão, surge o enfrentamento de modelos de tratamentos baseados em métodos proibicionistas e outros dispostos a utilizar a redução de danos como forma de atenuar os riscos e respeitar a vontade do indivíduo. Em meio a isso, a Prefeitura da cidade do Rio de Janeiro, através do Protocolo do Serviço Especializado em Abordagem Social, autoriza a internação compulsória dessa parte da população. O trabalho tem como proposta discutir se esse método de abordagem tem uma lógica de proteção ou de higienização da cidade, visando contribuir para o debate que acerca o tema. Em torno disso, o objetivo é uma reflexão crítica sobre as práticas das políticas públicas para população de rua e usuária de drogas
Polarization entangled photon-pair source based on quantum nonlinear photonics and interferometry
We present a versatile, high-brightness, guided-wave source of polarization
entangled photons, emitted at a telecom wavelength. Photon-pairs are generated
using an integrated type-0 nonlinear waveguide, and subsequently prepared in a
polarization entangled state via a stabilized fiber interferometer. We show
that the single photon emission wavelength can be tuned over more than 50 nm,
whereas the single photon spectral bandwidth can be chosen at will over more
than five orders of magnitude (from 25 MHz to 4 THz). Moreover, by performing
entanglement analysis, we demonstrate a high degree of control of the quantum
state via the violation of the Bell inequalities by more than 40 standard
deviations. This makes this scheme suitable for a wide range of quantum optics
experiments, ranging from fundamental research to quantum information
applications. We report on details of the setup, as well as on the
characterization of all included components, previously outlined in F. Kaiser
et al. (2013 Laser Phys. Lett. 10, 045202).Comment: 16 pages, 7 figure
Corrigendum: Effects of a 3-week inpatient multidisciplinary body weight reduction program on body composition and physical capabilities in adolescents and adults with obesity
A correction has been made to Funding. The correct Funding statement is: “Research funded by the Italian Ministry of Health.” The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated
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