418 research outputs found
Pervasive Displays Research: What's Next?
Reports on the 7th ACM International Symposium on Pervasive Displays that took place from June 6-8 in Munich, Germany
Acute brucella melitensis M16 infection model in mice treated with tumor necrosis factor-alpha inhibitors
Introduction: There is limited data in the literature about brucellosis related to an intracellular pathogen and anti-tumor necrosis factor alpha (anti-TNFα) medication. The aim of this study was to evaluate acute Brucella infections in mice receiving anti-TNFα drug treatment. Methodology: Anti-TNFα drugs were injected in mice on the first and fifth days of the study, after which the mice were infected with B. melitensis M16 strain. Mice were sacrificed on the fourteenth day after infection. Bacterial loads in the liver and spleen were defined, and histopathological changes were evaluated. Results: Neither the liver nor the spleen showed an increased bacterial load in all anti-TNFα drug groups when compared to a non-treated, infected group. The most significant histopathological findings were neutrophil infiltrations in the red pulp of the spleen and apoptotic cells with hepatocellular pleomorphism in the liver. There was no significant difference among the groups in terms of previously reported histopathological findings, such as extramedullary hematopoiesis and granuloma formation. Conclusions: There were no differences in hepatic and splenic bacterial load and granuloma formation, which indicate worsening of the acute Brucella infection in mice; in other words, anti-TNFα treatment did not exacerbate the acute Brucella spp. infection in mice. © 2015 Kutlu et al
Structure and propertties of ball milled utrahigh-molecular weight Polyethylene - clay composite
In this work the composite material based on polymer matrix filled with clay is studied. The preparation of powder composition consists of mechanical activation of substances and further common ball milling of polymer and clay in a high energy planetary ball mill. The process is divided into two stages; the first stage involves crushing of clay to obtain a nanosized powder, and in the second stage preparation of powdered nanocomposite is carried out. New clay-polymer composite shows considerable increase in modulus of elasticity and a decrease in coefficient of friction
4,5-dianilinophtalimide protects neuroendocrine cells against serum deprivation-induced stress and apoptosis
OBJECTIVE: The aim of this study was to reveal the effects of 4,5-dianilinophthalimide (DAPH), which inhibits amyloid β fibrillization, against serum deprivation (SD)-induced apoptosis and the possible mechanisms in differentiated PC12 neuron cells. METHODS: Firstly, we evaluated whether DAPH protects cell viability exposed to SD by MTT assay. Next, we examined the changes of phospho-p38 MAPK (Thr180/Tyr182), phospho-HSP27 (Ser82), phospho-c-JUN (Ser73) and cleaved-CASP3 (Asp175) profiles by immunoblotting, in PC12 cells exposed to SD. Intracellular reactive oxygen species (ROS) level was also measured. RESULTS: SD induced apoptosis accompanied by up-regulation of phospho-p38 MAPK (Thr180/Tyr182), phospho-HSP27 (Ser82), phospho-c-JUN (Ser73), cleaved-CASP3 (Asp175) and intracellular ROS content. Co-treatment with nontoxic doses of DAPH prevented apoptosis by the attenuation of activated proteins and reduction of ROS level. These results suggest that serum deprivation-induced apoptosis inhibited by DAPH administration. CONCLUSION: We have provided for the first evidence that DAPH has a neuroprotective effect on SD-caused stress, probably via contributing the reestablishment of redox homeostasis. © 2013 Neuroendocrinology Letters
Nanoantenna-enhanced ultrafast nonlinear spectroscopy of a single gold nanoparticle
Optical nanoantennas are a novel tool to investigate previously unattainable
dimensions in the nanocosmos. Just like their radio-frequency equivalents,
nanoantennas enhance the light-matter interaction in their feed gap. Antenna
enhancement of small signals promises to open a new regime in linear and
nonlinear spectroscopy on the nanoscale. Without antennas especially the
nonlinear spectroscopy of single nanoobjects is very demanding. Here, we
present for the first time antenna-enhanced ultrafast nonlinear optical
spectroscopy. In particular, we utilize the antenna to determine the nonlinear
transient absorption signal of a single gold nanoparticle caused by mechanical
breathing oscillations. We increase the signal amplitude by an order of
magnitude which is in good agreement with our analytical and numerical models.
Our method will find applications in linear and nonlinear spectroscopy of
nanoobjects, ranging from single protein binding events via nonlinear tensor
elements to the limits of continuum mechanics
Microbubble Composition and Preparation for High-Frequency Contrast-Enhanced Ultrasound Imaging: In Vitro and in Vivo Evaluation
Although high-frequency ultrasound imaging is gaining attention in various applications, hardly any ultrasound contrast agents (UCAs) dedicated to such frequencies (>15 MHz) are available for contrast-enhanced ultrasound (CEUS) imaging. Moreover, the composition of the limited commercially available UCAs for high-frequency CEUS (hfCEUS) is largely unknown, while shell properties have been shown to be an important factor for their performance. The aim of our study was to produce UCAs in-house for hfCEUS. Twelve different UCA formulations A-L were made by either sonication or mechanical agitation. The gas core consisted of C4F10 and the main coating lipid was either 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC; A-F formulation) or 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC; G-L formulation). Mechanical agitation r
Evidence for long-term Gamma-ray and X-ray variability from the unidentified TeV source HESS J0632+057
HESS J0632+057 is one of only two unidentified very-high-energy gamma-ray
sources which appear to be point-like within experimental resolution. It is
possibly associated with the massive Be star MWC 148 and has been suggested to
resemble known TeV binary systems like LS I +61 303 or LS 5039. HESS J0632+057
was observed by VERITAS for 31 hours in 2006, 2008 and 2009. During these
observations, no significant signal in gamma rays with energies above 1 TeV was
detected from the direction of HESS J0632+057. A flux upper limit corresponding
to 1.1% of the flux of the Crab Nebula has been derived from the VERITAS data.
The non-detection by VERITAS excludes with a probability of 99.993% that HESS
J0632+057 is a steady gamma-ray emitter. Contemporaneous X-ray observations
with Swift XRT reveal a factor of 1.8+-0.4 higher flux in the 1-10 keV range
than earlier X-ray observations of HESS J0632+057. The variability in the
gamma-ray and X-ray fluxes supports interpretation of the ob ject as a
gamma-ray emitting binary.Comment: 8 pages, 3 figures, Accepted for publication in The Astrophysical
Journa
VERITAS Observations of the gamma-Ray Binary LS I +61 303
LS I +61 303 is one of only a few high-mass X-ray binaries currently detected
at high significance in very high energy gamma-rays. The system was observed
over several orbital cycles (between September 2006 and February 2007) with the
VERITAS array of imaging air-Cherenkov telescopes. A signal of gamma-rays with
energies above 300 GeV is found with a statistical significance of 8.4 standard
deviations. The detected flux is measured to be strongly variable; the maximum
flux is found during most orbital cycles at apastron. The energy spectrum for
the period of maximum emission can be characterized by a power law with a
photon index of Gamma=2.40+-0.16_stat+-0.2_sys and a flux above 300 GeV
corresponding to 15-20% of the flux from the Crab Nebula.Comment: accepted for publication in The Astrophysical Journa
Detection of Extended VHE Gamma Ray Emission from G106.3+2.7 with VERITAS
We report the detection of very-high-energy (VHE) gamma-ray emission from
supernova remnant (SNR) G106.3+2.7. Observations performed in 2008 with the
VERITAS atmospheric Cherenkov gamma-ray telescope resolve extended emission
overlapping the elongated radio SNR. The 7.3 sigma (pre-trials) detection has a
full angular extent of roughly 0.6deg by 0.4deg. Most notably, the centroid of
the VHE emission is centered near the peak of the coincident 12CO (J = 1-0)
emission, 0.4deg away from the pulsar PSR J2229+6114, situated at the northern
end of the SNR. Evidently the current-epoch particles from the pulsar wind
nebula are not participating in the gamma-ray production. The VHE energy
spectrum measured with VERITAS is well characterized by a power law dN/dE =
N_0(E/3 TeV)^{-G} with a differential index of G = 2.29 +/- 0.33stat +/-
0.30sys and a flux of N_0 = (1.15 +/- 0.27stat +/- 0.35sys)x 10^{-13} cm^{-2}
s^{-1} TeV^{-1}. The integral flux above 1 TeV corresponds to ~5 percent of the
steady Crab Nebula emission above the same energy. We describe the observations
and analysis of the object and briefly discuss the implications of the
detection in a multiwavelength context.Comment: 5 pages, 2 figure
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