Analysis of Coverage Region for MIMO Relay Network with Multiple Cooperative DF-Relays

We study and analyze coverage region in MIMO communication systems for a multiple-relay network with decode-and-forward (DF) strategy at the relays. Assuming that there is a line-of-sight (LOS) propagation environment for source-relay channels and channel state information is available at receivers (CSIR), we consider the objective of maximizing coverage region for a given transmission rate and show numerically the significant effect of propagation environment on capacity bounds, optimal relay location and coverage region. Also, we study the situation in which two adjacent relays cooperate in transmission signals to the destination and show analytically that the coverage region is extended compared to noncooperative scenario.Comment: Accepted for publication in International Symposium on Wireless Communication Systems (ISWCS) 201

Mycosynthesis of Silver Nanoparticles from Candida albicans and its Antibacterial Activity against Escherichia coli and Staphylococcus aureus

Purpose: To produce and characterize silver nanoparticles using Candida albicans and evaluate its antibacterial properties.Methods: Extracellular silver nanoparticles were biosynthesized using C. albicans. The biomass obtained from cultures of C. albicans was used to synthesize silver nanoparticles in 1.5 mM silver nitrate solution. Characterization of the biosynthesized nanoparticles was carried out using ultraviolet (UV)- visible spectrometry and scanning electron microscopy (SEM). The antibacterial properties of the nanoparticles were determined by agar disc diffusion method against Escherichia coli and Staphylococcus aureus.Results: Incubation of C. albicans with silver nitrate solution produced silver nanoparticles after 2 – 4 h as evidenced by change in the color of the reaction mixture. The formation of silver nanoparticles was confirmed by UV-visible spectroscopy which showed absorption peak between 300 – 800 nm, being the characteristic wavelength range of silver nanoparticles. SEM revealed the varying morphology of the nanoparticles which had a size range of 20 – 80 nm. Furthermore, the nanoparticles showed significant antimicrobial activity (p < 0.05).Conclusion: The biosynthesized silver nanoparticles hold some promise for various industrial applications, including drug delivery.Keywords: Antibacterial activity, Candida albicans, Escherichia coli, Mycosynthesis, Silver nanoparticles, Staphylococcus aureu

A Review of Microsurgery Versus Endoscopy: Controversies for Treatment of Colloid Cysts

Background: There is controversy about the value of endoscopic methods compared to microsurgical methods in the treatment of challenging colloidal cysts. This study aimed to review the findings of literature which studied microsurgery or neuroendoscopy in the colloid cyst.Methods: An advanced search in PubMed, Science Direct, and Google Scholar databases performed using keywords such as: “microsurgery,” “endoscopy,” “microsurgery versus endoscopy,” and “colloid cysts.”Results: Reviewing the findings of related studies showed some differences in sections of surgical management, microsurgery, endoscopy, complete cyst resection, recurrence rate, length of stay, and complications between the two surgical methods in the treatment of colloid cyst.Conclusion: Despite some disadvantages of endoscopy, it seems this method has more privileges than the other methods

Malva sylvestris inhibits Candida albicans biofilm formation

Introduction: Candidiasis-associated biofilm formed by Candida species complicates treatment and contributes to unacceptable high mortality rates. We performed the aqueous and ethanol extracts of the different parts of Malva sylvestris, Dorema aucheri, Ferulago angulata and Citrullus colocynthis plants to identify best plant extract that inhibits growth of Candida albicans or Candida krusei, and conducted a series of follow-up studies to examine the inhibitors of C. albicans biofilm formation of the identified plant extract.Methods: The antifungal activities of the aqueous and ethanol extracts of the different parts of M. sylvestris, D. aucheri, F. angulata and C. colocynthis plants were evaluated in vitro using disk diffusion test and broth microdilution test against C. albicans and C. krusei. The crystal violet assay, morphological response and expression pattern of hyphal wall protein 1 (HWP1) gene were carried out to investigate the biofilm-inhibitory properties of the best plant extract tested in C. albicans.Results: The screen identified ethanol extract of M. sylvestris root that largely represented antifungal activity among the tested extracts. M. sylvestris root inhibited C. albicans biofilm formation. Ethanol extract of M. sylvestris root demonstrated significant reduction in C. albicans biofilm formation (P &lt; 0.005). Moreover, morphological observation of ethanol extract of M. sylvestris root treated cells confirmed a decrease in biofilm thickness and cellular density. Finally, ethanol extract of M. sylvestris root displayed significant down-regulation of HWP1.Conclusion: These results provide proof of concept for the implementation of ethanol extract of M. sylvestris root as inhibitor of C. albicans biofilm formation.</p