Symmetry and reciprocity constraints on diffraction by gratings of quasi-planar particles

Symmetry and reciprocity constraints on polarization state of the field diffracted by gratings of quasi-planar particles are considered. It is shown that the optical activity effects observed recently in arrays of quasi-planar plasmonic particles on a dielectric substrate are due to the reflection of the field at the air-dielectric slab interface and are proportional to this reflection coefficient.Comment: 11 pages, 3 figures, 12 references; minor corrections for better appearanc

Isolation and Antibiotic Susceptibility of Bacteria from Otitis Media Infections in Children in Rabat Morocco

An inflammation of the middle ear by bacteria, viruses or champignons is called otitis media. The objective of this study was to determine the microbial etiology of otitis media in children in Rabat, and susceptibility pattern commonly prescribed antibiotics. Samples of ear swabs were collected from patients at the pediatric hospital, CHU Ibn Sina Rabat, during the period between February 2012 and March 2013. The total number of isolates was 67 (66 bacteria and Candida spp 1). Of these 66 bacteria spp, Streptococcus pneumoniae was the highest number (27) followed by Pseudomonas aeruginosa (16), Staphylococcus aureus (15), Escherichia coli (3), Klebsiella spp (3), Proteus species (2), and candida spp (1). This study out showed that the peak incidence was found in the age group 0-5 years (62,69%), followed by the group 5-10 years (20.90%), by cons, the group age 10-16 years was a rate of 16.41%. All bacteria were resistant to penicillin. . Pseudomonas aeruginosa, Escherichia coli and Klebsiella spp were resistant to certain antibiotics such as ofloxacin, amoxicillin, amoxicillin+clavulanic-acid, levofloxacin and cefuroxime. All strains of streptocoques pneumoniae were sensitive to ciprofloxacin, but all resistant to amoxicillin, cefuroxime and penicillin. All strains of Proteus spp were susceptible to ciprofloxacin, levofloxacin, ofloxacin, only resistant to amoxicillin. Accordingly, sufficient knowledge of the antibacterial susceptibility of bacteria, the judicious use of antibiotics and the periodic evaluation of the resistance profile of antibiotic sensitivity in the region is very important in order to avoid failure in the treatment of otitis media in children. Keywords: Otitis media, bacteria, antibacterial susceptibility, resistance, childre

Propagation of surface waves at the interface between nonlinear MTMs and anisotropic materials

Metamaterials (MTMs), which have both negative permeability and negative permittivity, have potential applications in optoelectronics and communications. These materials are fabricated in laboratories which is an added advantage. The focus of this work is on the propagation of surface waves at the interface between nonlinear MTMs and anisotropic materials in the optical range. The dispersion equation is derived from Maxwell’s equations. The dispersion equation is solved numerically to study the characteristics of the propagated wave. Only TE modes are considered. The results display the dependence of the propagating waves on the characteristics of the structure composite materials

Human papillomavirus genotype prevalence and distribution among Moroccan women

Background:Human papillomavirus (HPV) is the major etiologic agent of invasive cervical cancer, vulvar and vaginal cancer. It has been estimated that, worldwide, 70% of cervical cancers are due to HPV-16 and HPV-18. Malignant transformation appears to require the presence of additional cofactors such as pregnancy, smoking and immunosuppression. The aim of the present study was to determine the prevalence and distribution of HPV genotypes among Moroccan women.  Methods:Between January 1, 2011, and December 31, 2012, 277 cervical samples collected from confirmed women who attended the department of gynecology and obstetrics at Mohamed V Military teaching hospital, Rabat, Morocco, were analyzed in the laboratory of virology for HPV in vitro diagnosis and genotyping and for cytology in laboratory of pathology.Results:High-risk HPV DNA was detected in 101 (36%) samples, with higher prevalence in women ≥45 (43%) years. The overall prevalence of HPV infection and multiple infections in the study samples was 76% and 21%, respectively. The most frequent HPV genotypes were HPV-16 (31%). Human papillomavirus DNA detection was inversely related to maternal age. The risk of HPV infection was significantly reduced in women aged older than 30 years. The history of gynaecological problem showed significant association with the HPV positive test.Conclusion:In Morocco, the diagnosis of cervical lesions rests exclusively on the cytology-based screening that offers substantial protection, although current coverage is low. The introduction of HPV DNA testing in cervical cancer management will greatly benefit early stage HPV detection and help prevent development of cervical lesions and cancer. Screening pregnant women offer a significant opportunity for the Moroccan National Program against cervical cancer to control.  

Potentiel de biodégradation de corynébactéries isolées d'une zone polluée par les hydrocarbures du pétrole

Le degré de pollution engendré par l’effluent de la raffinerie de pétrole de Sidi Kacem (Maroc) a été estimé pendant l’année 1997. La détermination de l’oxygène dissous, de la demande chimique et biochimique en oxygène, ainsi que d’autres caractères physico-chimiques, a montré que l’effluent brut de la raffinerie est fortement pollué et que cette pollution se répercute sur la qualité des eaux de l’oued Rdom recevant cet effluent. Une collection de souches bactériennes capables de croître en présence du pétrole brut comme seule source de carbone a été isolée à partir de différentes stations de la zone polluée. L’identification des bactéries à Gram positif a été réalisée à l’aide de galeries d’identification. L’utilisation de la réaction en chaîne de la polymérase (PCR) et les Primers “ERIC” a montré que les bactéries isolées possèdent les séquences consensus inversées répétées. Ces séquences engendrent un profil en accord avec l’identification de quatre espèces appartenant au genre Corynebacterium : C. diphteriae, C. fascians, C. pseudotuberculosis, C. xerosis, d’une souche de Rhodoccocus equi et d’un Actynomyces. Le pourcentage de biodégradation du pétrole brut a été déterminé, il est de l’ordre de 40 % en quatre semaines pour les corynébactéries et la souche de Rhodoccocus et il est inférieur à 10 % pour la souche d’Actinomyces sp. Ces résultats sont en faveur d’un rôle de la flore à Gram positif dans la bioremédiation du site pollué

Occult hepatitis B virus infection in Moroccan HIV infected patients

Background: The purpose of this study is to assess the prevalence of Occult hepatitis B virus Infection (OBI) among antiretroviral treatment naïve HIV-1 infected individuals in Morocco and to determine factors favouring its occurrence.Methods: The retrospective study was conducted in the Mohammed V military teaching hospital in Rabat between January 2010 and June 2011. It included patients with confirmed HIV infection, tested negative to serological detection of HBV surface antigen (HBsAg) and did not received antiviral treatment or hepatitis B vaccine. All samples were tested for anti-HBc, anti-HBs and anti-HCV antibodies using enzyme immunoassay (ELISA). The detection of HBV DNA was performed by real-time PCR using two specific primers for a gene in the region C of the viral genome. The sensitivity of the technique was 20 copies/ml.Results: A total of 82 samples were analyzed, 19 (23 %) were found to have isolated anti-HBc, 07 (8.5%) with associated anti-HBc and Anti-HBs. No anti-HCV marker was detected on these screening samples. The HBV DNA was detected in 48 (58%) samples, of which, males constituted 58% (28/48). The mean age of these patients was 38 ± 8.2 (29-56), the median HIV-1 viral load and CD4 cell count HIV-1 infected patients were 127500 (54108-325325) copies/ml and 243 [80-385] cells/mm3 respectively and 27.1% (13/48) of these patients were found to have isolated anti-HBc. A significant correlations between DNA HBV and HIV viral load higher than 100000 copies/ml (P = 0.004), CD4 cell count lower than 400 cells/mm3 (P = 0.013, P = 0.006) and isolated anti-HBc samples (P <0.005) were founded. However there was no significant association with age, sex, transmission mode and clinical stage.  Conclusion: The consequences of this high prevalence of OBI in Morocco need to be considered in laboratory diagnosis of HBV infection in HIV infected patients and the PCR seems to be inevitable for a better diagnosis and therapy.

Design of Voltage control Oscillator using Nonlinear Composite Right/Left-Handed Transmission Line

In the present work, we propose a voltage control oscillator (VCO) at high frequency consists of nonlinear composite right/left-handed transmission line (CRLH-TL) loaded with Resonant Tunneling Diode (RTD). We designed three prototype device examples. The first one consists of one cell with short circuit at the beginning of the cell between ground and patch, and 50 Ω load resistance were added at the end of the cell between ground and patch. The second one is similar to the first prototype but with open circuit at the beginning of the cell instated of short circuit. The third prototype consists of one cell with two 50 Ω load resistances added between ground and patch at the beginning and at the end of the cell. The proposed VCO models are capable of generating oscillations at frequencies between 4.87- 14.9 GHz. In our simulations, we used OrCAD and ADS software to analyze the proposed circuit

Caractérisation antibiotypique et biochimique des souches marocaines de Salmonella enteritidis d'origine humaine et alimentaire

L’antibiotypie et la biotypie des souches marocaines de Salmonella enteritidis d’origine humaine et alimentaire ont été investiguées. Cinquante et une souches ont été isolées entre janvier 96 et décembre 97. Parmi les 31 souches humaines, dix souches se sont révélées résistantes aux antibiotiques dont quatre étaient résistantes à plus d’un antibiotique. Parmi les 20 souches alimentaires, onze étaient résistantes dont 6 résistantes à plus d’un antibiotique. Les résultats obtenus montrent une similitude avec les souches méditerranéennes. Les profils biochimiques atypiques étaient rencontrés aussi bien pour les souches alimentaires que pour les souches humaines. L’atypie affecte aussi bien les souches sensibles que les souches résistantes aux antibiotiques. Les caractères atypiques concernent le métabolisme de certains sucres et acides aminés

Transformation-based spherical cloaks designed by an implicit transformation-independent method: theory and optimization

Based on the concept of the cloak generating function, we propose an implicit transformation-independent method for the required parameters of spherical cloaks without knowing the needed coordinate transformation beforehand. A non-ideal discrete model is used to calculate and optimize the total scattering cross-sections of different profiles of the generating function. A bell-shaped quadratic spherical cloak is found to be the best candidate, which is further optimized by controlling the design parameters involved. Such improved invisibility is steady even when the model is highly discretized.European Commission (European Network of Excellence 'METAMORPHOSE')Foundation for Fundamental Research (Belarus) (F08MS-06