9,155 research outputs found

    Molecular aspects of MERS-CoV

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    This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Middle East respiratory syndrome coronavirus (MERS-CoV) is a betacoronavirus which can cause acute respiratory distress in humans and is associated with a relatively high mortality rate. Since it was first identified in a patient who died in a Jeddah hospital in 2012, the World Health Organization has been notified of 1735 laboratory-confirmed cases from 27 countries, including 628 deaths. Most cases have occurred in Saudi Arabia. MERS-CoVancestors may be found in OldWorld bats of the Vespertilionidae family. After a proposed bat to camel switching event, transmission of MERS-CoV to humans is likely to have been the result of multiple zoonotic transfers from dromedary camels. Human-to-human transmission appears to require close contact with infected persons, with outbreaks mainly occurring in hospital environments. Outbreaks have been associated with inadequate infection prevention and control implementation, resulting in recommendations on basic and more advanced infection prevention and control measures by the World Health Organization, and issuing of government guidelines based on these recommendations in affected countries including Saudi Arabia. Evolutionary changes in the virus, particularly in the viral spike protein which mediates virus-host cell contact may potentially increase transmission of this virus. Efforts are on-going to identify specific evidence-based therapies or vaccines. The broad-spectrum antiviral nitazoxanide has been shown to have in vitro activity against MERS-CoV. Synthetic peptides and candidate vaccines based on regions of the spike protein have shown promise in rodent and non-human primate models. GLS-5300, a prophylactic DNA-plasmid vaccine encoding S protein, is the first MERS-CoV vaccine to be tested in humans, while monoclonal antibody, m336 has given promising results in animal models and has potential for use in outbreak situations

    Performance of FSO Communication System under Various Weather Condition

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    In this paper, the performance FSO communication under different weather condition is theoretically analyzed, using L-PPM modulation technique and a Si PIN photodiodes receiver over FSO channels. Based on the attenuation coefficient of different weather and impacts on a received signal power, SNR, BER, and channel are analyzed. Simulation results indicate that the performance of 16-PPM is more suited for FSO communication. Keywords: Communications, FSO Communications, Bit Error Rate, Channel Capacity

    Modeling and simulation of a 3-Ñ„ induction motor based on two types of WFA

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    This paper has been proposed to simulate the transient model of 3-Ф cage rotor induction motor based on winding function approach (WFA). According to this method the motor is assumed to be consist of an electrical circuits on both stator and rotor. The magneto motive forces (MMF) that have been generated by these circuits play a role for coupling them together. Then mutual and self-inductances will be easily computed using WFA. Two types of WFA have been used to build and simulate the model of the induction motor. In the one part type, it’s assumed that the coupling MMF between stator and rotor have a non-sinusoidal shapes according to the actual windings distribution over the motor slots. While in second part type the generated MMF in are assumed to have sinusoidal waveform. The suggested models may be used to simulate the dynamic as well as steady state performance of a faulty and non-faulty motor. A simulation of the suggested models that consists of m-rotor bars and n-stator phases multiple coupled circuit-based has been performed using matlab m.file and the results of the motor current have been proved in its nonlinear way by using WFA

    Bond strength of a new Kevlar fiber-reinforced composite post with semi-interpenetrating polymer network (IPN) matrix

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    This study aimed to evaluate the bond strength and the penetration depth of two adhesive systems to a new experimental semi-IPN fiber post versus a commercial post. Experimental Kevlar fiber (KF) and control everStick®POST (ES) posts (n=20/ group) with a diameter of 1.5 mm were used, 10 posts coated with StickResin (SR) and the other 10 posts coated with Scotch bond multipurpose (SBMP) adhesives. Composite resin buildup was performed over each post, using a cylindrical plastic mold (10 mm × 6 mm). Four discs of 2 mm thickness were prepared from each post/composite buildup and underwent pushout bond strength test at a crosshead speed of 0.5 mm/min accompanied by failure mode analysis. A further three specimens from each subgroup were bonded with adhesives labeled with 0.1 wt% Rhodamine B and embedded in acrylic resin, sectioned and examined under a confocal Laser-scanning microscope (CLSM) to measure the depth of resin penetration. Statistical analysis included ANOVA and Tukey test, the significance level was assumed at a p-value less than 0.05. The push-out bond strength of KF was comparable to that of ES with both SBMP and SR adhesives (P >0.05). Bond strength value for SBMP was higher than SR adhesive in either ES and KF posts with no significant difference (P > 0.05). ES exhibited higher adhesive penetration depth compared with KF (p<0.05). The bond strength of Kevlar post was comparable with the everStick post and the semi-interpenetrating structure of Kevlar post displayed some adhesive monomers diffusion indicating its usefulness as a new intracanal post

    Adenosine A2A Receptor Blockade Prevents Rotenone-Induced Motor Impairment in a Rat Model of Parkinsonism

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    Pharmacological studies implicate the blockade of adenosine receptorsas an effective strategy for reducing Parkinson’s disease (PD) symptoms. The objective of this study is to elucidate the possible protective effects of ZM241385 and 8-cyclopentyl-1, 3-dipropylxanthine, two selective A2A and A1 receptor antagonists, on a rotenone rat model of PD. Rats were split into four groups: vehicle control (1 ml/kg/48 h), rotenone (1.5 mg/kg/48 h, s.c.), ZM241385 (3.3 mg/kg/day, i.p) and 8-cyclopentyl-1, 3-dipropylxanthine (5 mg/kg/day, i.p). After that, animals were subjected to behavioral (stride length and grid walking) and biochemical (measuring concentration of dopamine levels using high performance liquid chromatography, HPLC). In the rotenone group, rats displayed a reduced motor activity and disturbed movement coordination in the behavioral tests and a decreased dopamine concentration as foundby HPLC. The effect of rotenone was partially prevented in the ZM241385 group, but not with 8-cyclopentyl-1,3-dipropylxanthine administration. The administration of ZM241385 improved motor function and movement coordination (partial increase of stride length and partial decrease in the number of foot slips) and an increase in dopamine concentration in the rotenone-injected rats. However, the 8-cyclopentyl-1,3-dipropylxanthine and rotenone groups were not significantly different. These results indicate that selective A2A receptor blockade by ZM241385, but not A1 receptor blockadeby 8-cyclopentyl-1,3-dipropylxanthine, may treat PD motor symptoms. This reinforces the potential use of A2A receptor antagonists as a treatment strategy for PD patients

    A proposal for testing Quantum Gravity in the lab

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    Attempts to formulate a quantum theory of gravitation are collectively known as {\it quantum gravity}. Various approaches to quantum gravity such as string theory and loop quantum gravity, as well as black hole physics and doubly special relativity theories predict a minimum measurable length, or a maximum observable momentum, and related modifications of the Heisenberg Uncertainty Principle to a so-called generalized uncertainty principle (GUP). We have proposed a GUP consistent with string theory, black hole physics and doubly special relativity theories and have showed that this modifies all quantum mechanical Hamiltonians. When applied to an elementary particle, it suggests that the space that confines it must be quantized, and in fact that all measurable lengths are quantized in units of a fundamental length (which can be the Planck length). On the one hand, this may signal the breakdown of the spacetime continuum picture near that scale, and on the other hand, it can predict an upper bound on the quantum gravity parameter in the GUP, from current observations. Furthermore, such fundamental discreteness of space may have observable consequences at length scales much larger than the Planck scale. Because this influences all the quantum Hamiltonians in an universal way, it predicts quantum gravity corrections to various quantum phenomena. Therefore, in the present work we compute these corrections to the Lamb shift, simple harmonic oscillator, Landau levels, and the tunneling current in a scanning tunneling microscope.Comment: v1: 10 pages, REVTeX 4, no figures; v2: minor typos corrected and a reference added. arXiv admin note: has substantial overlap with arXiv:0906.5396 , published in a different journa

    POTENTIAL IMPACT OF COQ10 AND VITAMIN E AGAINST (STZ) INDUCED METABOLIC DETERIORATION IN THE ALBINO RATS

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    Objective: This study evaluates the hypoglycemic effect of COQ10 and Vitamin E are determined using STZ induced diabetic rats.Methods: Rats selected for this study were divided into five groups of ten rats each as follows: first group Normal control rats, the second is considered as diabetic groups, injected intraperitoneal with a single dose of STZ (60 mg/kg B. wt). the third group Diabetic rats orally administered glibenclamide drug 10 mg/kg B. wt daily for 30 d 4th. And 5th groups were treated orally glibenclamide combined with vitamin E (2% concentration added to the normal basal diet), or coenzyme Q10 at the dose of 10 mg/kg i. p. daily for 30 consecutive days in addition histological examinations of liver, kidney and brain were carried out to confirm the biochemical changes of the diabetic group of rats.Results: All liver enzymes activities alanine and aspartate transferases and alkaline phosphatase (AST, ALT and ALP respectively), kidney function tests; creatinine and total urea, inflammatory biomarkers; CRP, IL-10 and TNF-α. Neurotransmitters; acetylcholine and acetylcholine esterase were enhanced with the highest degree in groups treated with COQ10 or vitamin E in addition to glibenclamide dug, almost restore the normal histological architecture of liver, kidney and brain.Conclusion: Orally supplemented glibenclamide with coenzyme Q10 or vitamin E showing significantly reduced blood glucose levels in STZ induced diabetic rats. It also showed hypolipidemia as well as hepatoprotective effects, enhance histological feature of liver, kidney and brain.Â

    Interleukin-12B gene polymorphism and visceral Leishmaniasis in Iraqi patients

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    The present study aimed to determine the role of IL12-1188 genetic polymorphism in susceptibility or resistant to visceral Leishmaniasis (VL) by studying single nucleotide polymorphism (SNP) in the gene of IL12B at position -1188 in 44 Iraqi VL patients and 40 healthy controls. IL-12 serum level showed no significant difference between patients and controls (5.33 ± 3.26 vs.2.17 ± 0.36 pg/ml). In addition, SNP analysis revealed that neither genotypes nor alleles of IL12B-1188 revealed a significant variation between VL patients and controls. To determine the impact of IL12B-1188 genotypes on IL-12 serum level, VL patients and controls were distributed according to their serum level in the three genotypes of this cytokine. It was found that IL12-1188 CC genotype demonstrated a significant increased level of IL-12 (26.16 ±19.76 pg/ml) in patients compared to CA and AA genotype (1.35 ± 0.35 pg/ml and 1.48 ± 0.23 pg/ml respectively) of patients. Keywords: Visceral leishmaniasis, Interleukin-12, Single nucleotide polymorphis
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