1,264 research outputs found
Nitric Oxide: Implications for Vascular and Endovascular Surgery
AbstractNitric oxide has a key role in vascular homeostasis. It plays a protective role by suppressing abnormal proliferation of vascular smooth muscle following various pathological situations including atherosclerosis and restenosis after vascular interventions such as balloon angioplasty, stent deployment and bypass grafting. It also has strong antiplatelet and anti-thrombogenic properties. In this review, possible applications to daily vascular and endovascular surgery practice, including systemic use of NO donors, enhancing endogenous production of NO by L-arginine and gene therapy, local delivery strategies and coating stents and grafts with NO-delivering/enhancing chemicals are reviewed
Bioinspired Optoelectronic Nose with Nanostructured Wavelength-Scalable Hollow-Core Infrared Fibers
Cataloged from PDF version of article.A digital photonic nose concept based on infrared absorption inside a hollow core infrared-transmitting fi ber array is presented. Wavelength- scalable photonic bandgap fi bers fi lter specifi c energy photons from a blackbody source, where volatile compounds selectively absorb photons depending on their chemical absorption spectrum. The pattern resulting in the detector array is processed as a binary signature
Opinion Mining on Non-English Short Text
As the type and the number of such venues increase, automated analysis of
sentiment on textual resources has become an essential data mining task. In
this paper, we investigate the problem of mining opinions on the collection of
informal short texts. Both positive and negative sentiment strength of texts
are detected. We focus on a non-English language that has few resources for
text mining. This approach would help enhance the sentiment analysis in
languages where a list of opinionated words does not exist. We propose a new
method projects the text into dense and low dimensional feature vectors
according to the sentiment strength of the words. We detect the mixture of
positive and negative sentiments on a multi-variant scale. Empirical evaluation
of the proposed framework on Turkish tweets shows that our approach gets good
results for opinion mining
The inner circumstellar disk of the UX Ori star V1026 Sco
The UX Ori type variables (named after the prototype of their class) are
intermediate-mass pre-main sequence objects. One of the most likely causes of
their variability is the obscuration of the central star by orbiting dust
clouds. We investigate the structure of the circumstellar environment of the
UX~Ori star V1026 Sco (HD 142666) and test whether the disk inclination is
large enough to explain the UX Ori variability. We observed the object in the
low-resolution mode of the near-infrared interferometric VLTI/AMBER instrument
and derived H- and K-band visibilities and closure phases. We modeled our AMBER
observations, published Keck Interferometer observations, archival MIDI/VLTI
visibilities, and the spectral energy distribution using geometric and
temperature-gradient models. Employing a geometric inclined-ring disk model, we
find a ring radius of 0.15 +- 0.06 AU in the H band and 0.18 +- 0.06 AU in the
K band. The best-fit temperature-gradient model consists of a star and two
concentric, ring-shaped disks. The inner disk has a temperature of
1257^{+133}_{-53} K at the inner rim and extends from 0.19 +- 0.01 AU to 0.23
+- 0.02 AU. The outer disk begins at 1.35^{+0.19}_{-0.20} AU and has an inner
temperature of 334^{+35}_{-17} K. The derived inclination of
48.6^{+2.9}_{-3.6}deg approximately agrees with the inclination derived with
the geometric model (49 +- 5deg in the K band and 50 +- 11deg in the H band).
The position angle of the fitted geometric and temperature-gradient models are
163 +- 9deg (K band; 179 +- 17deg in the H band) and 169.3^{+4.2}_{-6.7}deg,
respectively. The narrow width of the inner ring-shaped model disk and the disk
gap might be an indication for a puffed-up inner rim shadowing outer parts of
the disk. The intermediate inclination of ~50deg is consistent with models of
UX Ori objects where dust clouds in the inclined disk obscure the central star
Antiglycative effect of fruit and vegetable seed extracts: Inhibition of AGE formation and carbonyl-trapping abilities
BACKGROUND: Advanced glycation end-products (AGEs) are the final products derived from the non-enzymatic glycation process. AGEs are involved in the development of several health complications associated with diabetes and aging. Searching for anti- AGE extracts is necessary to mitigate the effects of age-related pathologies. RESULTS: The antioxidant and antiglycative activities of eight aqueous extracts of fruit and vegetable seeds were evaluated. All seed extracts (3.6 mg mL-1) exhibited anti-AGE activity in protein-glucose assay, ranging from 20 to 92% inhibition compared with aminoguanidine (4.87 mmol L-1). Green pepper extract exerted the highest anti-AGE activity. However, peach and pomegranate extracts exhibited the highest anti-AGE activity in protein-methylglyoxal assay, ranging from 0 to 79% inhibition. Hazelnut, almond and sesame extracts were not effective when methylglyoxal was the promoter. Apricot and peach extracts appeared to inhibit the formation of AGEs through their capacity for direct trapping of 1,2-dicarbonyls (IC50=0.14 mg mL-1). No relationship between antioxidant and phenolic compound content and antiglycative activity was found. Therefore other hydrophilic constituents in addition to phenolic acids must be involved in the antiglycative activity of the extracts. CONCLUSION: Aqueous extracts of fruits and vegetables can be considered in the prevention of glycation-associated complications of age-related pathologies. © 2012 Society of Chemical Industry.Peer Reviewe
Analysis of genetic variation among accessions of critically endangered Rhaponticoides iconiensis and Rhaponticoides mykalea based on RAPD and SDSPAGE markers
Rhaponticoides iconiensis (Hub.-Mor.) M.V.Agab and Greuter is a rare and endangered endemic species of the Konya region of Turkey. One related taxon, Rhaponticoides mykalea (Hub.-Mor.) M.V.Agab andGreuter, is morphologically similar but occurs in different geographical locations. This study has been conducted on the biology of this threatened plant in order to understand better the factors that shouldbe included in the development of conservation practices. The genetic variations were studied using RAPD markers and SDS-PAGE profiles of total seed proteins for three R. iconiensis populations and two R. mykalea populations. The analyzed R. iconiensis populations belonged to different soil types (calcareous and volcanic). The analyzed R. iconiensis and R. mykalea populations belonged to different bioclimatic zones. A genetic diversity within populations was detected both by SDS-PAGE and RAPD for R. iconiensis populations. The level of variation did not differ with respect to soil type for the species studied. Populations collected from the same soil types carried more polymorphisms than those grown in different zones. The genetic diversity was revealed more clearly for all populations byRAPD than through analyzing proteins. Differentiation between ecological groups was higher than that revealed within groups. Conservation programs should take into account the level of genetic diversity within population revealed by these markers according to soil types
Contribution of heme oxygenase 2 to blood pressure regulation in response to swimming exercise and detraining in spontaneously hypertensive rats
Background: We aimed to determine the effects of exercise followed by detraining on systolic blood pressure (SBP), heme oxygenase 2 (HO-2) expression, and carboxyhemoglobin (COHb) concentration in spontaneously hypertensive rats (SHR) to explain the role of carbon monoxide (CO) in this process. Material/Methods: Animals were randomized into exercised and detrained groups. Corresponding sedentary rats were grouped as Time 1–2. Swimming of 60 min/5 days/week for 10 weeks was applied. Detraining rats discontinued training for an additional 5 weeks. Gene and protein expressions were determined by real-time PCR and immunohistochemistry. Results: Aorta HO-2 histological scores (HSCORE) of hypertensive rats were lower, while SBP was higher. Swimming caused enhancement of HO-2 immunostaining in aorta endothelium and adventitia of SHR. Exercise induced elevation of blood COHb index in SHR. Synchronous BP lowering effect of exercise was observed. HO-2 mRNA expression, HSCORE, and blood COHb index were unaltered during detraining, while SBP was still low in SHR. Conclusions: CO synthesized by HO-2 at least partly plays a role in SBP regulation in the SHR-and BP-lowering effect of exercise. Regular exercise with short-term pauses may be advised to both hypertensives and individuals who are at risk. © Med Sci Monit
A Simple Chaotic Neuron Model : Stochastic Behavior of Neural Networks
We have shortly reviewed the occurrence of the post-synaptic potentials
between neurons, the relation between EEG and neuron dynamics, as well as
methods of signal analysis. We supposed a simple stochastic model representing
electrical activity of neuronal systems. The model is constructed using the
Monte Carlo simulation technique. The results yielded EEG-like signals with
their phase portraits in three-dimensional space. The Lyapunov exponent was
positive, indicating a chaotic behavior. The correlation dimension of the
EEG-like signals was found to be .92, which was smaller than those reported by
others. It was concluded that this neuron model may provide valuable clues
about the dynamic behavior of neural systems.Comment: 14 pages, 6 figure
Comparative Study Regarding the Welding Behavior of Galvanized Steel Using Laser Welding and Gas Metal Arc Welding Processes
Gas metal arc welding (GMAW) and laser welding are two commonly used joining methods. In this study, these two welding methods were used to join the galvanized sheets. For GMAW, the process parameters were: welding wire diameter, shielding gas flow, welding speed, current and wire feed speed. In term of laser welding, the analyzed parameters were: welding speed, power and pulse duration. In order to establish the effects of the main parameters on the resistance of the welded joint, changes were made to the values of a single process parameter, and the others were kept constant. The combined welded samples were examined non-destructively using X-rays method and then were subjected to destructive tensile tests, analyzing the tensile strength values
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