3,647 research outputs found
BN Nanotube Serving as a Gas Chemical Sensor for NāO by Parallel Electric Field
Density functional theory calculations were performed to understand the electronic properties of Cāā, BāāNāā, BāāPāā, and (6, 0) BNNT interacted with NāO molecule in the presence and absence of an external electric field using the B3LYP method and 6-31G** basis set. The adsorption of NāO from O-side on the surface of (6, 0) BNNT has high sensitivity in comparison with BāāNāā nano-cage. The adsorption energy of NāO (O-side) on the sidewalls of BāāNāā and BNNT in the presence of an electric field are ā21.01 and ā15.48 kJ molā»Ā¹, respectively. Our results suggest that in the presence of an electric field, the BāāNāā nano-cage is the more energetically notable upon the NāO adsorption than (6, 0) BNNT, Cāā, and BāāPāā. Whereas, our results indicate that the electronic property of BNNT is more sensitive to NāO molecule at the presence of an electric field than BāāNāā nano-cage. It is anticipated that BNNT could be a favorable gas sensor for the detection of NāO molecule. Ā© 2016, Springer Science+Business Media New York
Physics of brain dynamics: Fokker-Planck analysis reveals changes in EEG delta-theta interactions in anaesthesia
We use drift and diffusion coefficients to reveal interactions between different oscillatory processes underlying a complex signal and apply the method to EEG delta and theta frequencies in the brain. By analysis of data recorded from rats during anaesthesia, we consider the stability and basins of attraction of fixed points in the phase portrait of the deterministic part of the retrieved stochastic process. We show that different classes of dynamics are associated with deep and light anaesthesia, and we demonstrate that the predominant directionality of the interaction is such that theta drives delt
Frequency of Antimicrobial-Resistant Genes in Salmonella enteritidis Isolated from Traditional and Industrial Iranian White Cheeses
Iranian white cheese is one of the most important kinds of cheese produced in large scale with high consumption in the country. This dairy product transmits bacterial pathogens like Salmonella spp. Antibiotic resistant Salmonella are widespread in the world. This study was performed to evaluate the frequency of antimicrobial-resistant Salmonella enteritidis and related genes isolated from traditional and industrial Iranian white cheeses. A total of 200 traditional and industrial Iranian white cheeses were collected within Chaharmahal Va Bakhtiari province (southwest Iran). After culturing on specific media using standard bacterial tests the Salmonella sp. was isolated. For specific detection of S. enteritidis from other Salmonella strains sefA gene was studied. Finally, the antibiotic susceptibility patterns were investigated. Results showed that 17 % of cheese samples were contaminated by Salmonella and 5.5 % of specimens by S. enteritidis. The frequencies of resistance genes including tetA, tetB, tetC, cat3, and floR in isolated S. enteritidis were 36.4, 54.5, 81.8, 54.5, and 36.4 %, respectively. All isolated S. enteritidis were susceptible to ciprofloxacin, cefotaxime, and ceftazidime (100 %). In addition, most of them were resistance to chloramphenicol (64 %) and susceptible to gentamicin (98 %). The Salmonella contamination was more frequent in traditional Iranian white cheeses (11.5 %) as compared to industrial (5.5 %) samples (p < 0.05). As compared to industrial samples, high level of resistant genes in Salmonella enteritidis isolated from traditional Iranian white cheeses were observed (p < 0.05). Therefore, traditional Iranian white cheeses are important source of Salmonella contamination in the country hence examination of dairy products for the presence of this pathogen is importan
An experimental study of permeability determination in the lab
Understanding the flow characteristics in laminar and turbulent flow regime is important for different aspects of reservoir and production engineering. One of the most important parameters in fluid flow is the permeability of the porous media. It is common practice in the industry to use Darcy and Forchheimers equations for characterising the fluid flow in the porous media at laminar and turbulent regimes, respectively. Core flooding experiments were performed with 1.5-inch diameter size core samples from limestone and sandstone formations. The permeability of the samples was measured in the laminar regime at basis flow rate. Then, the flow rate was increased in different steps and permeability was measured, accordingly. The plot of permeability versus flow rate was used to track the evolution of the flow regimes in the core porous media. There are different challenges to monitor the transition between laminar and turbulent regime through core flooding experiments. These challenges are discussed in this paper through both literature review and also experimental results. The results indicated that the core sample preparation, experiment control parameters and also test profiles are important aspects when measuring permeability in the lab. Ā© 2012 WIT Press
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Testicular expression of TDRD1, TDRD5, TDRD9 and TDRD12 in azoospermia.
BACKGROUND: Tudor domain-containing proteins (TDRDs) play a critical role in piRNA biogenesis and germ cell development. piRNAs, small regulatory RNAs, act by silencing of transposons during germline development and it has recently been shown in animal model studies that defects in TDRD genes can lead to sterility in males. METHODS: Here we evaluate gene and protein expression levels of four key TDRDs (TDRD1, TDRD5, TDRD9 and TDRD12) in testicular biopsy samples obtained from men with obstructive azoospermia (OA, nā=ā29), as controls, and various types of non-obstructive azoospermia containing hypospermatogenesis (HP, 28), maturation arrest (MA, nā=ā30), and Sertoli cell-only syndrome (SCOS, nā=ā32) as cases. One-way ANOVA test followed by Dunnett's multiple comparison post-test was used to determine inter-group differences in TDRD gene expression among cases and controls. RESULTS: The results showed very low expression of TDRD genes in SCOS specimens. Also, the expression of TDRD1 and TDRD9 genes were lower in MA samples compared to OA samples. The expression of TDRD5 significantly reduced in SCOS, MA and HP specimens than the OA specimens. Indeed, TDRD12 exhibited a very low expression in HP specimens in comparison to OA specimens. All these results were confirmed by Western blot technique. CONCLUSION: TDRDs could be very important in male infertility, which should be express in certain stages of spermatogenesis
The Truncated Moment Problem for Unital Commutative R-Algebras
Let A be a unital commutative R-algebra, B a linear subspace of A and K a
closed subset of the character space of A. For a linear functional L: B --> R,
we investigate conditions under which L admits an integral representation with
respect to a positive Radon measure supported in K. When A is equipped with a
submultiplicative seminorm, we employ techniques from the theory of positive
extensions of linear functionals to prove a criterion for the existence of such
an integral representation for L. When no topology is prescribed on A, we
identify suitable assumptions on B, A, L and K which allow us to construct a
seminormed structure on A, so as to exploit our previous result to get an
integral representation for L. We then use our main theorems to obtain, as
applications, several well known results on the classical truncated moment
problem, the moment problem for point processes, and the subnormal completion
problem for 2-variable weighted shifts
Interleukin-1 alpha variation is associated with the risk of developing preeclampsia
Objective Preeclampsia is a syndrome that affects 5 of all pregnancies, producing substantial maternal and prenatal morbidity and mortality. Several studies have reported that cytokine genes are associated with the persistence of preeclampsia or the severity of the disease. The aim of this study is to investigate the relationships between the polymorphisms of interleukin-1 alpha-889 (IL-1A) gene and preeclampsia. Method Genomic DNA was extracted from the peripheral blood of 305 patients with preeclampsia and 325 normal controls from Sayyad Shirazi Hospital of Golestan University. Then subjected to SSP-PCR amplification. STATA software and the chi square test were used for statistic calculations. Results The frequencies of IL-1A -889 genotypes C/C, T/T and C/T in preeclampsia cases were 34.8, 8.2, 57 and in controls were 20.9, 7.6 and 71.3 respectively. There was a significant 1.5 fold excess frequency in genotype C/C in cases (CI = 1.44-3.07, OR = 2.1, P = 0.0001). There was a significant difference in the frequencies of alleles or genotypes in IL-1A promoter regions between patients with preeclampsia and the control group. Turkomans showed the highest frequency of the C allele and Sistanies had the lowest frequency of the C allele in preeclampsia compared to control groups (CI = 1.5-3.9, OR = 2.48, P = 0.0001). Conclusion Our findings suggest that the IL-1A-899C/C genotype and C allele are associated with susceptibility to preeclampsia. Ā© 2015 Elsevier Ireland Ltd. All rights reserved
AMPA Receptor Surface Expression Is Regulated by S-Nitrosylation of Thorase and Transnitrosylation of NSF
The regulation of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) trafficking affects multiple brain functions, such as learning and memory. We have previously shown that Thorase plays an important role in the internalization of AMPARs from the synaptic membrane. Here, we show that N-methyl-d-aspartate receptor (NMDAR) activation leads to increased S-nitrosylation of Thorase and N-ethylmaleimide-sensitive factor (NSF). S-nitrosylation of Thorase stabilizes Thorase-AMPAR complexes and enhances the internalization of AMPAR and interaction with protein-interacting C kinase 1 (PICK1). S-nitrosylated NSF is dependent on the S-nitrosylation of Thorase via trans-nitrosylation, which modulates the surface insertion of AMPARs. In the presence of the S-nitrosylation-deficient C137L Thorase mutant, AMPAR trafficking, long-term potentiation, and long-term depression are impaired. Overall, our data suggest that both S-nitrosylation and interactions of Thorase and NSF/PICK1 are required to modulate AMPAR-mediated synaptic plasticity. This study provides critical information that elucidates the mechanism underlying Thorase and NSF-mediated trafficking of AMPAR complexes
Paleogene dinoflagellate cysts and thermal maturity from Pabdeh Formation ( Zagros basin, west of Iran)
Palynological investigation on 132 samples from the 428m thick outcrop section of Late Paleocene to EarlyĀ Oligocene of the Pabdeh Formation in southwestern Iran yielded 55 species of dinoflagellate cysts and allowedĀ establishment of seven biozones. Quantity of marine palynomorph elements indicate an open marineĀ environment at that time interval but, a slight increase in number of spore and pollen grains in some samplesĀ indicate suitable conditions for forest development as a consequence of increase in climate humidity. TheĀ species are common in various latitudes and most of them are cosmopolitan. Thermal maturity indexĀ measurement indicates oil prone nature for majority of the samples.Keyword: Pabdeh Formation, Dinoflagellate cysts, Paleogene, Palynostratigraphy, Thermal maturit
CFA optimizer: A new and powerful algorithm inspired by Franklin's and Coulomb's laws theory for solving the economic load dispatch problems
Copyright Ā© 2018 John Wiley & Sons, Ltd. This paper presents a new efficient algorithm inspired by Franklin's and Coulomb's laws theory that is referred to as CFA algorithm, for finding the global solutions of optimal economic load dispatch problems in power systems. CFA is based on the impact of electrically charged particles on each other due to electrical attraction and repulsion forces. The effectiveness of the CFA in different terms is tested on basic benchmark problems. Then, the quality of the CFA to achieve accurate results in different aspects is examined and proven on economic load dispatch problems including 4 different size cases, 6, 10, 15, and 110-unit test systems. Finally, the results are compared with other inspired algorithms as well as results reported in the literature. The simulation results provide evidence for the well-organized and efficient performance of the CFA algorithm in solving great diversity of nonlinear optimization problems
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