613 research outputs found
Morphological evaluation of the mandibular lingula using cone-beam computed tomography
Background: Lingula is a tongue-like flap of bone that overlaps the mandibular foramen antero-medially and location is clinically significant in oral and maxillofacial surgeries. The aim of this study was to assess the shape and precise location of lingula using cone-beam computed tomography (CBCT).
Materials and methods: In this study, 3-dimensional images provided by CBCT of 63 patients (28 females, 35 males, age range 25–70 years) were retrospectively evaluated. All CBCT images were performed due to implant planning. From both sides of 63 mandibles were classified in the following shapes: triangular, truncated, nodular and assimilated. The location was determined by 5 distances from the lingula: the anterior and the posterior borders of the mandibular ramus, mandibular notch and lover border of mandible. Height of the lingula was measured from the lingular tip to the mandibular foramen.
Results: Nodular shape of lingula was the most commonly found (32.5%). The mean distance of lingula from anterior and posterior borders of mandibular ramus was 18.5 ± 2.3 and 16.9 ± 3.5 mm, respectively. The lingula was located at 18.1 ± 3.6 mm from the mandibular notch and 38.3 mm from the lover border of mandible. The mean height of lingula was 7.8 ± 2.4 mm.
Conclusions: The present study provides the morphological variation and localization of the lingula. The lingula is an important clinical landmark for mandibular osteotomy, and for determining the distance to mandibular foramen entrance
Multiplexed nanoplasmonic biosensor for one-step simultaneous detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urine.
Development of rapid and multiplexed diagnostic tools is a top priority to address the current epidemic problem of sexually transmitted diseases. Here we introduce a novel nanoplasmonic biosensor for simultaneous detection of the two most common bacterial infections: Chlamydia trachomatis and Neisseria gonorrhoeae. Our plasmonic microarray is composed of gold nanohole sensor arrays that exhibit the extraordinary optical transmission (EOT), providing highly sensitive analysis in a label-free configuration. The integration in a microfluidic system and the precise immobilization of specific antibodies on the individual sensor arrays allow for selective detection and quantification of the bacteria in real-time. We achieved outstanding sensitivities for direct immunoassay of urine samples, with a limit of detection of 300 colony forming units (CFU)/mL for C. trachomatis and 1500CFU/mL for N. gonorrhoeae. The multiplexing capability of our biosensor was demonstrated by analyzing different urine samples spiked with either C. trachomatis or N. gonorrhoeae, and also containing both bacteria. We could successfully detect, identify and quantify the levels of the two bacteria in a one-step assay, without the need for DNA extraction or amplification techniques. This work opens up new possibilities for the implementation of point-of-care biosensors that enable fast, simple and efficient diagnosis of sexually transmitted infections
Cooperative spontaneous emission in nonuniform media
The subject of this paper is modification of cooperative spontaneous emission
by a nonuniform medium, with nonuniform distributions of electromagnetic field.
A brief analyzis is presented and it is postulated, that if spontaneous
emission from an atom is strongly suppressed, cooperative emission with another
atom may be a preferred emission channel and counteract the suppression.Comment: The final publication is available at http://www.epj.or
Coupled-resonator optical waveguides: Q-factor and disorder influence
Coupled resonator optical waveguides (CROW) can significantly reduce light
propagation pulse velocity due to pronounced dispersion properties. A number of
interesting applications have been proposed to benefit from such slow-light
propagation. Unfortunately, the inevitable presence of disorder, imperfections,
and a finite Q value may heavily affect the otherwise attractive properties of
CROWs. We show how finite a Q factor limits the maximum attainable group delay
time; the group index is limited by Q, but equally important the feasible
device length is itself also limited by damping resulting from a finite Q.
Adding the additional effects of disorder to this picture, limitations become
even more severe due to destructive interference phenomena, eventually in the
form of Anderson localization. Simple analytical considerations demonstrate
that the maximum attainable delay time in CROWs is limited by the intrinsic
photon lifetime of a single resonator.Comment: Accepted for Opt. Quant. Electro
Visualizing dimensionality reduction of systems biology data
One of the challenges in analyzing high-dimensional expression data is the
detection of important biological signals. A common approach is to apply a
dimension reduction method, such as principal component analysis. Typically,
after application of such a method the data is projected and visualized in the
new coordinate system, using scatter plots or profile plots. These methods
provide good results if the data have certain properties which become visible
in the new coordinate system and which were hard to detect in the original
coordinate system. Often however, the application of only one method does not
suffice to capture all important signals. Therefore several methods addressing
different aspects of the data need to be applied. We have developed a framework
for linear and non-linear dimension reduction methods within our visual
analytics pipeline SpRay. This includes measures that assist the interpretation
of the factorization result. Different visualizations of these measures can be
combined with functional annotations that support the interpretation of the
results. We show an application to high-resolution time series microarray data
in the antibiotic-producing organism Streptomyces coelicolor as well as to
microarray data measuring expression of cells with normal karyotype and cells
with trisomies of human chromosomes 13 and 21
Room temperature plasmon laser by total internal reflection
Plasmon lasers create and sustain intense and coherent optical fields below
light's diffraction limit with the unique ability to drastically enhance
light-matter interactions bringing fundamentally new capabilities to
bio-sensing, data storage, photolithography and optical communications.
However, these important applications require room temperature operation, which
remains a major hurdle. Here, we report a room temperature semiconductor
plasmon laser with both strong cavity feedback and optical confinement to
1/20th of the wavelength. The strong feedback arises from total internal
reflection of surface plasmons, while the confinement enhances the spontaneous
emission rate by up to 20 times.Comment: 8 Page, 2 Figure
Lasing oscillation in a three-dimensional photonic crystal nanocavity with a complete bandgap
We demonstrate lasing oscillation in a three-dimensional photonic crystal
nanocavity. The laser is realized by coupling a cavity mode, which is localized
in a complete photonic bandgap and exhibits the highest quality factor of
~38,500, with high-quality semiconductor quantum dots. We show a systematic
change in the laser characteristics, including the threshold and the
spontaneous emission coupling factor by controlling the crystal size, which
consequently changes the strength of photon confinement in the third dimension.
This opens up many interesting possibilities for realizing future ultimate
light sources and three-dimensional integrated photonic circuits and for more
fundamental studies of physics in the field of cavity quantum electrodynamics.Comment: 14 pages, 4 figure
Q-ball formation in the wake of Hubble-induced radiative corrections
We discuss some interesting aspects of the -ball formation during the
early oscillations of the flat directions. These oscillations are triggered by
the running of soft stemming from the nonzero energy density
of the Universe. However, this is quite different from the standard -ball formation. The running in presence of gauge and Yukawa couplings
becomes strong if is sufficiently large. Moreover, the -balls which are formed during the early oscillations constantly evolve, due
to the redshift of the Hubble-induced soft mass, until the low-energy
supersymmtery breaking becomes dominant. For smaller , -balls are not formed during early oscillations because of the shrinking of
the instability band due to the Hubble expansion. In this case the -balls are formed only at the weak scale, but typically carry smaller
charges, as a result of their amplitude redshift. Therefore, the Hubble-induced
corrections to the flat directions give rise to a successful -ball
cosmology.Comment: 7 revtex pages, few references corrected and added, final version to
appear in Phys. Rev.
Quantum phase transitions of light
Recently, condensed matter and atomic experiments have reached a length-scale
and temperature regime where new quantum collective phenomena emerge. Finding
such physics in systems of photons, however, is problematic, as photons
typically do not interact with each other and can be created or destroyed at
will. Here, we introduce a physical system of photons that exhibits strongly
correlated dynamics on a meso-scale. By adding photons to a two-dimensional
array of coupled optical cavities each containing a single two-level atom in
the photon-blockade regime, we form dressed states, or polaritons, that are
both long-lived and strongly interacting. Our zero temperature results predict
that this photonic system will undergo a characteristic Mott insulator
(excitations localised on each site) to superfluid (excitations delocalised
across the lattice) quantum phase transition. Each cavity's impressive photon
out-coupling potential may lead to actual devices based on these quantum
many-body effects, as well as observable, tunable quantum simulators. We
explicitly show that such phenomena may be observable in micro-machined diamond
containing nitrogen-vacancy colour centres and superconducting microwave
strip-line resonators.Comment: 11 pages, 5 figures (2 in colour
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