605 research outputs found
Conceptual design of a thermal neutron radiography facility in the cyclotron 30 LC using the MCNPX cod
The MCNPX code and the ENDF/B-VII cross-section library have been used to optimize the geometrical dimensions of the thermal neutron radiography facility (TNRF) based on the cyclotron 30 LC using a Be target as a neutron source and the Protons Beam Channel (PBC) with energy 15.0 MeV and 20.0 MeV. Thermal, epithermal and fast neutron energy ranges have been selected as < 0.4 eV, 0.4 eV–10 keV and >10 keV, respectively. The calculated values of the thermal neutron flux at the main collimator exit (MCE) have been estimated to be 1.31´105 n/cm2.s and 1.05´105 n/cm2.s, 1.97´105 n/cm2.s and 1.66´105 n/cm2.s for the ratio L/D = 90 and L/D = 110, and the PBC with energy 15.0 MeV and 20.0 MeV, respectively. In addition, the cooling system of the Be target has been designed using solid works program. The simulated results showed that the maximum temperature of the Be target is lower than the melting temperature of the Be target. The use of neutronic and gamma filters has been eliminated in the design phase reducing the economic cost had anyone thought to build this beam
QFT results for neutrino oscillations and New Physics
The CP asymmetry in neutrino oscillations, assuming new physics at production
and/or detection processes, is analyzed. We compute this CP asymmetry using the
standard quantum field theory within a general new physics scenario that may
generate new sources of CP and flavor violation. Well known results for the CP
asymmetry are reproduced in the case of V -A operators, and additional
contributions from new physics operators are derived. We apply this formalism
to SUSY extensions of the Standard Model where the contributions from new
operators could produce a CP asymmetry observable in the next generation of
neutrino experiments.Comment: 6 pages, 3 figures, version to be published in Phys.Rev.
Can dynamic contrast enhanced magnetic resonance imaging change treatment planning in endometrial carcinoma?
AbstractPurposeTo detect the diagnostic accuracy of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) in the assessment of myometrium and cervix infiltration and lymph node (L.N) status in patients with endometrial carcinoma.Patients and methodsForty patients with pathologically proven endometrial carcinoma underwent preoperative MRI assessment in the National Cancer Institute, Cairo University, Egypt over three years from 2009 to 2012. Every case had one stage for the T2 weighted images (T2 WIs) alone and another stage for the combined T2 and DCE images according to the revised international federation of gynecology and obstetrics (FIGO) classification. The pathological findings after surgery were the reference standard.ResultsThe sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of T2 WIs in detection of deep myometrial invasion were 80%, 72%, 70%, 84% and 79%, respectively and 87%, 90%, 85%, 92% and 87%, respectively for DCE-MRI. For cervical infiltration, T2 WIs showed 78.5%, 88%, 73%, 90.5% and 82.5%, respectively while DCE-MRI showed 92%, 97%, 92%, 97% and 95%, respectively. T2 WIs and DCE-MRI had 100% sensitivity and 85% specificity for the detection of L.N metastasis.ConclusionDCE-MRI can accurately detect invasion of the myometrium and cervix in cases of endometrial carcinoma
INTEGRATION OF ICT IN EFL/ESL TEACHERS' TRAINING AND SELF-EFFICACY BELIEFS AS PERCEIVED BY THE TRAINERS
Purpose of Study: The current study aimed at revealing the integration of information and communications technology (ICT) in EFL/ESL teachers' training and self-efficacy beliefs as perceived by trainers. A group of (64) trainers from different countries (Palestine, UK, USA, Iran, Lebanon, Yemen, Iraq) completed the two instruments of the study.
Methodology: The first instrument was a survey of the actuality of ICT integration in the training; it comprises (47) items distributed into nine domains, i.e. PowerPoint, Facebook, Wiki, YouTube, Blogs, Email, Google, Mobile, and Platform\E-course. The second instrument was a self-efficacy scale which consists of (14) items. The results of trainers' responses revealed that Emails, Mobile, and Google are often used with relative weights (%78.59, %68.13, and %68.02) respectively, whereas Wikis were never used i.e. relative weight (%28.96). The differences in integrating ICTs between male and female trainers were statistically insignificant. Furthermore, there were no statistically significant differences due to the respondents' period of experience.
Results: The results also showed that there were no statistically significant differences in the respondents' integration of ICT due to country of origin. The trainers' self-efficacy wobbles between 66.88 and 58.13 with a total of 61.70, which is moderate. Based on the study findings, the researchers recommend arousing trainers and trainees' awareness regarding integrating more ICTs in their training courses and encouraging them to try the different ICTs which make it easier for trainees to grasp the training material
Effect of micro TiOâ‚‚ on cement mortar
TiO2 is a primary photocatalytic ingredient. If incorporated into building materials, it can keep surfaces clean and significantly reduce smog-forming air pollutants. Many researchers have focused on the ability of Nano TiO2 to reduce NOx emissions or other pollutants. However, developing countries are unable to widely utilize Nano materials due to cost and technology barriers, in spite of their great need to find means for protecting structures from pollution and improve air quality. Some studies proved that micro TiO2 (commercial grade) also has photocatalytic properties. However, the effect of this inclusion on key mechanical and durability properties needs to be verified before being recommended for wide use. In this research the effect of commercial grade TiO2 powder on fresh state flow, compressive strength, shrinkage, sulfate resistance and carbonation. The results indicated that TiO2 decreased the workability as mortars became more sticky and dry with increased TiO2 content. The compressive strength was also reduced in TiO2 containing samples compared to the control samples especially at early ages .However, TiO2 powder as an additive in mortar was useful in reducing carbonation due to the filler effect. No samples in the current investigation showed signs of cracking or expansive mass loss due to sulfate exposure. It is recommended that TiO2 powder should be used as an additive to the mortar plaster to help in controlling the air pollution problem. However, some mix adjustment may be needed to counteract the loss in flow and strength due to the inclusion of TiO2 powder
Anti-quorum sensing activity of some medicinal plants
Background: Quorum sensing is the key regulator of virulence factors of Pseudomonas aeruginosa such as biofilm formation, motility, productions of proteases, hemolysin, pyocyanin, and toxins. The aim of this study was to explore the effect of the extracts from some medicinal plants on quorum sensing and related virulence factors of P. aeruginosa.Material and Methods: Quorum sensing inhibitory (OSI) effect of the alcohol extracts of 20 medicinal plants was evaluated by Chromobacterium violaceum reporter using agar cup diffusion method. The efficient QSI extracts were tested for their activity against biofilm synthesis, motility, and synthesis of pyocyanin from P. aeruginosa PA14Results: The extracts of Citrus sinensis, Laurus nobilis, Elettaria cardamomum, Allium cepa, and Coriandrum sativum exhibited potent quorum quenching effect. On the other hand, Psidium guajava and Mentha longifolia extracts showed lower QSI activity. These extracts exhibited significant elimination of pyocyanin formation and biofilm development of Pseudomonas aeruginosa PA14. In addition, they significantly inhibited twitching and swimming motilities of P. aeruginosa PA14.Conclusion: This study illustrated, for the first time, the importance of C. sinensis, L. nobilis, E. cardamomum, A. cepa, and C. sativum as quorum sensing inhibitors and virulence suppressors of P. aeruginosa. Thus, these plants could provide a natural source for the elimination of Pseudomonas pathogenesis.Keywords: Quorum sensing inhibitory activity, P. aeruginosa, Chromobacterium violaceum, virulence factor
Superior control of inflammatory pain by corticotropin-releasing factor receptor 1 via opioid peptides in distinct pain-relevant brain areas
Background: Under inflammatory conditions, the activation of corticotropin-releasing factor (CRF) receptor has been shown to inhibit pain through opioid peptide release from immune cells or neurons. CRF's effects on human and animal pain modulation depend, however, on the distribution of its receptor subtypes 1 and 2 (CRF-R1 and CRF-R2) along the neuraxis of pain transmission. The objective of this study is to investigate the respective role of each CRF receptor subtype on centrally administered CRF-induced antinociception during inflammatory pain.
Methods: The present study investigated the role of intracerebroventricular (i.c.v.) CRF receptor agonists on nociception and the contribution of cerebral CRF-R1 and/or CRF-R2 subtypes in an animal model of Freund's complete adjuvant (FCA)-induced hind paw inflammation. Methods used included behavioral experiments, immunofluorescence confocal analysis, and reverse transcriptase-polymerase chain reaction.
Results: Intracerebroventricular, but systemically inactive, doses of CRF elicited potent, dose-dependent antinociceptive effects in inflammatory pain which were significantly antagonized by i.c.v. CRF-R1-selective antagonist NBI 27914 (by approximately 60%) but less by CRF-R2-selective antagonist K41498 (by only 20%). In line with these findings, i.c.v. administration of CRF-R1 agonist stressin I produced superior control of inflammatory pain over CRF-R2 agonist urocortin-2. Intriguingly, i.c.v. opioid antagonist naloxone significantly reversed the CRF as well as CRF-R1 agonist-elicited pain inhibition. Consistent with existing evidence of high CRF concentrations in brain areas such as the thalamus, hypothalamus, locus coeruleus, and periaqueductal gray following its i.c.v. administration, double-immunofluorescence confocal microscopy demonstrated primarily CRF-R1-positive neurons that expressed opioid peptides in these pain-relevant brain areas. Finally, PCR analysis confirmed the predominant expression of the CRF-R1 over CRF-R2 in representative brain areas such as the hypothalamus.
Conclusion: Taken together, these findings suggest that CRF-R1 in opioid-peptide-containing brain areas plays an important role in the modulation of inflammatory pain and may be a useful therapeutic target for inflammatory pain control
Quorum sensing inhibitory activity of sub-inhibitory concentrations of β-lactams
Introduction: The virulence factors of Pseudomonas aeruginosa are under the control of quorum sensing (QS) signals. Hence, interference with QS prevents its pathogenesis.Objective: The aim of the present research is to assess the influence of some β-lactam antibiotics on cell communication and the release of different virulence factors.Methods: The minimal inhibitory concentrations of ceftazidime, cefepime and imipenem were evaluated by microbroth dilution method. The effect of sub-inhibitory concentration of the tested antibiotics on QS signals was investigated using reporter strain assay. In addition, different virulence factors (elastase, protease, pyocyanin and hemolysin) were estimated in the presence of their sub-inhibitory concentrations.Results: Low concentrations of ceftazidime, cefepime and imipenem caused significant elimination of the QS signals 3OHC12- HSL and C4-HSL up to 1/20 MIC. Furthermore, low concentrations of the tested antimicrobials suppressed virulence factors elastase and hemolysin. Moreover, 1/20 of their MICs reduced elastase, protease, pyocyanin and hemolysin.Conclusion: Utilization of β-lactam antibiotics at low concentrations could be an effective approach for prevention and treatment of P. aeruginosa infection.Keywords: Quorum sensing inhibition, β-lactams, Pseudomonas aeruginos
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