Half-metallicity in EuN: A First-Principles Calculation

We report on the electronic and magnetic properties of the rock salt (RS) and cesium chloride (CsCl) phases of EuN. Our calculation was performed within the framework of the density functional theory (DFT), as implemented in the Wien2k package. We have used the generalized gradient approximation (GGA) for the exchange correlation potential and, in certain, cases the Local Spin Density (LSDA) approximation, with the Hubbard interaction taken into account.  Our calculation demonstrates the presence of an energy gap in both of the RS and CsCl structures when only spin-polarized calculation is used. However, taking the Hubbard potential into consideration, via the LSDA+U scheme, led to the disappearance of the energy gap, and hence to the absence of the half-metallic behavior in this system. Keywords: rare-earth nitrides; magnetic moment; DFT; DOS; half metallicity; spin density

Molecular markers as a prognostic system for hepatocellular carcinoma

AbstractThe gene expression profile p16, c-erbB-3 and bcl2 in hepatocellular carcinoma (HCC) patients with and without associated HCV infection, was assessed. Forty-eight subjects were included in the study and divided equally into two groups: HCC with and without HCV associated infection. Adjacent paracancerous tissues were assessed as control samples. Correlations with various clinico-pathological parameters of the tumour were assessed: stage, grade, and tumour size. The c-erbB-3 oncogene was expressed in 83.33% (40/48) of the total HCC sample and in 31.25% (15/48) of the noncancerous lesions. C-erbB-3 was expressed in 87.5% (21/24) of the HCC cases with associated HCV infection and in 79.16% (19/24) of the HCC cases without associated HCV infection. Gene expression of c-erbB-3 was significantly correlated with the clinico-pathological parameters of the tumour. P16 gene expression was found in 12.5% (6/48) of the total HCC sample and in 25% (12/48) of the para-cancerous lesions. P16 was expressed in 12.5% (3/24) of HCC cases with and without associated HCV infection. Gene expression of p16 exhibited significant negative correlation with clinico-pathological parameters of the tumour. Bcl2 gene expression was found in 20.8% (10/48) of the total HCC sample and in the para-cancerous lesions. Bcl2 was expressed in 20.8% (5/24) of the HCC cases with and without HCV associated infection. Gene expression of bcl2 did not show significant correlations with the clinico-pathological parameters of the tumour. In conclusion, gene expression profiles of p16 and c-erbB-3 could be used as prognostic molecular markers in HCC

Immunomodulatory effects of food

There is a strong consensus that nutrition plays a role in modulating immune function and that the immune system needs adequate supply of nutrients to function properly. The complexity of the immune system supports this idea because its optimal functioning involves a variety of biological activities including cell division and proliferation, energy metabolism, and production of proteins. The micronutrients most often cited as being important to immune function include vitamins A, C, E, and B6, folate, iron, zinc, and selenium. Other nutrients mentioned as playing a role in immune function include beta-carotene (a precursor to vitamin A), vitamin B12, and vitamin D. On the other hand, over-activation of the immune system can lead to detrimental effects such as chronic inflammation or autoimmune diseases. In persons with allergies, a normally harmless material can be mistaken as an antigen. Some individuals develop an exaggerated immune response to food through developing food allergy which may be IgE mediated, non-IgE mediated, or mixed. This review will highlight the interaction between the immune system and some foods and food components in terms of modulation of immune functions by a variety of mechanisms.Egypt J Pediatr Allergy Immunol 2011;9(1):3-1

The critical level of vitamin D in childhood asthma

Objectives: Studies have suggested a significant link between vitamin D status and asthma. We sought to determine the cutoff level of25 hydroxy (25-OH) vitamin D that is significantly linked to asthma status in children.Methods: Our cross-sectional study comprised 90 asthmatic children, aged 2-18 years. They were evaluated clinically and classified according to asthma severity and control. Asthma control test (ACT) was performed in those aged above 4 years.Pulmonary functions were performed in cooperative children (n=59). Serum 25-OH vitamin D levels were measured by ELISA in all patients.Results: The study comprised 52 boys (57.7%) and 38 girls (42.3%) with mean age 7.03±4.36 years. Thirty-six patients (40%) had mild asthma, 37 (41%) moderate asthma and 17 (19%) had severe asthma. Forty-two patients (46.6%) had controlled asthma; 14 (15.6%) partially controlled and 34 (37.8%) had uncontrolled asthma. ACT score ranged: 11-26, with mean score: 18.9 ± 4.3 SD. Serum 25-OHvitamin D levels ranged between 2-48 ng/ml (mean± SD: 12.2 ± 9 ng/ml); levels were comparable among different grades of asthma severity (f= 1.975, p=0.145), while the uncontrolled asthma group showed the lowest levels (f=8.511, p <0.001). 25-OH vitamin D levels correlated positively with ACT score (r= 0.369, p= <0.001) but not with inhaled steroids doses or any of the pulmonary function parameters. A level of 7.5 ng/ml was associated with partial/completeuncontrol of asthma with 81 % sensitivity and 53 % specificity.Conclusion: 25-OH vitamin D levels below 7.5 ng/ml are associated with poor asthma status in children.Keywords: Asthma, allergy, children, severity, inhaled steroids, 25 hydroxy vitamin D

Experimental investigation of unsteady flows at large incidence angles in a linear oscillating cascade

The aerodynamics of a cascade of airfoils oscillating in torsion about the midchord is investigated experimentally at a large mean incidence angle and, for reference, at a low mean incidence angle. The airfoil section is representative of a modern, low aspect ratio, fan blade tip section. Time-dependent airfoil surface pressure measurements were made for reduced frequencies up to 0.8 for out-of-phase oscillations at Mach numbers up to 0.8 and chordal incidence angles of 0 deg and 10 deg. For the 10 deg chordal incidence angle, a separation bubble formed at the leading edge of the suction surface. The separated flow field was found to have a dramatic effect on the chordwise distribution of the unsteady pressure. In this region, substantial deviations from the attached flow data were found with the deviations becoming less apparent in the aft region of the airfoil for all reduced frequencies. In particular, near the leading edge the separated flow had a strong destabilizing influence while the attached flow had a strong stabilizing influence