Comparison of Three Methods for Diagnosis of Cutaneous Leishmaniasis

Background: Leishmaniasis is one of the infectious parasitic diseases of highest incidence in the world. Cutaneous Leishmaniasis (CL) has long been reported in Shiraz, Southern Iran. There is a need to find a sensitive and specific method for treatment and control of the disease.Methods: We have compared the sensitivity of the conventional methods microscopy and cultiva­tion of lesion scrapes against PCR amplification of parasite kinetoplast DNA from these sam­ples. The samples (n=219) were obtained from the patients clinically suspected of CL. The smears were stained with Giemsa for microscopy and cultured in Novy-Nicolle-McNeal (NNN) blood agar for promastigote growth. For PCR, the dry smears were scraped off the slides and DNA was extracted.Results: The positive rates from 219 specimens were 76.71%, 50.68%, and 93.61% for micros­copy, cultivation, and PCR, respectively. The highest correlation was found between PCR and micros­copy method (P= 0.014). In PCR assay, 95.61%, 3.9%, and 0.49% of the samples were identi­fied as Leishmania major, L. tropica, and dermatropic L. infantum, respectively.Conclusion: The PCR method appears to be the most sensitive for the diagnosis of CL and is valu­able for identifying the other species of Leishmania with confusing dermatropic signs

OFDMA-Based Medium Access Control for Next-Generation WLANs

Existing medium access control (MAC) schemes for wireless local area networks (WLANs) have been shown to lack scalability in crowded networks and can suffer from widely varying delays rendering them unsuited to delay sensitive applications, such as voice and video communications. These deficiencies are mainly due to the use of random multiple access techniques in the MAC layer. The design of these techniques is highly linked to the choice of the underlying physical (PHY) layer technology. The advent of new PHY schemes that are based on orthogonal frequency division multiple access (OFDMA) provides new opportunities for devising more efficient MAC protocols. We propose a new adaptive MAC design based on OFDMA technology. The design uses OFDMA to reduce collision during transmission request phases and makes channel access more predictable. To improve throughput, we combine the OFDMA access with a carrier sense multiple access (CSMA) scheme. Data transmission opportunities are assigned through an access point that can schedule traffic streams in both time and frequency (subchannels) domains. We demonstrate the effectiveness of the proposed MAC and compare it to existing mechanisms through simulation and by deriving an analytical model for the operation of the MAC in saturation mode

Removal of Amoxiclav Antibiotic from Aqueous Solutions Using Ultrasonic Waves

Antibiotics enter the environment, mainly aquatic environments, through the effluents of pharmaceutical industries, antibiotic factories, hospitals, human and animal sewage. Toxicity (carcinogenicity, mutagenicity and damage to the body's DNA), biodegradability, and drug resistance in antibiotics have caused these compounds to be called semi-persistent pollutants in the environment. The present study was conducted to investigate the effectiveness of ultrasonic waves in reducing the antibiotic amoxiclav in aqueous solutions. The discharge and flow velocity parameters have been neglected due to their insignificance. The investigated variables included contact time, amoxiclav concentration, and pH. Antibiotics were based on concentrations of 2 and 6 mg/L of Amoxiclav, retention time (30, 45, 60) minutes, and pH values (3, 7, 9) in an ultrasonic device with a volume of 10 liters and internal dimensions (20*30*50), and the frequency was set to 95. Then the remaining concentration in the samples was measured by HPLC. The obtained results were subjected to statistical analysis with SPSS software. As the retention time increases, the initial concentration of the antibiotic decreases, but on the contrary, as the initial concentration increases, the removal of the antibiotic decreases. The highest concentration reduction of amoxiclav in concentration 2 (mg/L) is about 50% in the retention time of 60 minutes and pH = 3, but in concentration of 6 (mg/L), the highest concentration reduction is in the same retention time and pH of about 47%. The advantages of ultrasonication are easy application, acceleration of chemical and biological processes, no production of secondary pollutants, reduction of suspended and soluble substances in water, and an effective and cheap method to remove the antibiotic Amoxiclav

Relationship between household food insecurity and food and nutrition literacy among children of 9-12 years of age: a cross-sectional study in a city of Iran

Objective: The aim of this study was to assess the relationship between household food insecurity (HFI) with food and nutrition literacy (FNLIT) in a sample of Iranian children. This cross sectional study was performed on 315 children aged 9 to 12 years recruited from the primary schools throughout Mashhad, Iran. The Household Food Insecurity Access Scale (HFIAS) was used to assess the HFI. Also, overall FNLIT score and its sub-categories were evaluated using a validated 40-item questionnaire. Results: The prevalence of HFI in the total sample was about 56. Also, almost 14 of students had a low FNLIT score. Food insecure children had significantly lower levels of FNLT and some subscales including nutrition knowledge, food choice literacy, and food label literacy than the food-secure subjects, moreover, they had a higher likelihood of having low FNLIT score (OR = 2.89, CI 1.03-8.09; p = 0.04). In conclusion, there is a negative association between HFI and FNLIT in children. Further studies to confirm this finding are needed. © 2020 The Author(s)

Phase Stability, Microstructure, and Mechanical Properties of Spark Plasma Sintered Nanocrystalline Boron-Doped AlCoFeMnNi High-Entropy Alloy

The microstructure and mechanical properties of mechanically alloyed and spark plasma sintered AlCoFeMnNi₋ₓB (x = 0, 0.5, 1, and 5 at. %) high-entropy alloys (HEAs) have been investigated. Boron-doped HEAs were synthesized using mechanical alloying up to 50 h of milling. Synthesized powders were then consolidated at 850, 900, and 950 °C for 10 min under a uniaxial pressure of 40 MPa using spark plasma sintering (SPS). A scanning electron microscope, which was equipped with energy dispersive spectroscopy (EDS), together with an optical microscope (OM) were used to analyze the microstructural evolution. X-ray diffraction analysis was used to differentiate the phases formed in the solution. The mechanical properties of the sintered specimens were analyzed using the shear-punch test (SPT). The fracture surface of the SPT samples was studied using SEM. Thermodynamic calculations revealed that by employing this process, it is possible to produce solid solution HEAs with a duplex FCC + BCC structure. It was shown that boron-doped AlCoFeMnNi high-entropy alloys contain some unique attributes. SPS at 900 °C for a sample with boron up to 0.5 at. % leads to the formation of an alloy with the highest shear strength. A further increase in the boron content in the boron-doped HEAs exhibited a decrease in the maximum shear strength. Finally, the correlations between the microstructural and mechanical characteristics of the sintered boron-containing high-entropy alloys are discussed

Enhanced Controlled-Access and Contention-Based Algorithms for IEEE 802.11e Wireless LANs

Abstrac

Natural frequencies of functionally graded plates with porosities via a simple four variable plate theory: an analytical approach

In this paper, the free vibration analysis of rectangular plates composed of functionally graded materials with porosities is investigated based on a simple first-order shear deformation plate theory. The network of pores in assumed to be empty or filled by low pressure air and the material properties of the plate varies through the thickness. Using Hamilton's principle and utilizing the variational method, the governing equations of motion of FG plates with porosities are derived. Considering two boundary layer functions, the governing equations of the system are rewritten and decoupled. Finally, two decoupled equations are solved analytically for Lévy-type boundary conditions so as to obtain the eigenfrequencies of the plate. The effects of porosity parameter, power law index, thickness-side ratio, aspect ratio, porosity distribution and boundary conditions on natural frequencies of the plate are investigated in detail

A Case Report of Nasopharyngeal Linguatuliasis in Tehran, Iran and Characterization of the Isolated Linguatula serrata

A vermiform specimen taken from a 10-year-old boy patient with the chief complain of sneezing, coughing and nasal dis-charge with a history of consumption of fast snack in the day before and liver of sheep in two weeks ago was referred for diagnosis to the Helminth Taxonomy Laboratory, Dept. of Mdical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Iran in Dec. 2006. The specimen was processed and examined by light microscope and drew the features of specimen by Camera Lucida. Eventually, the specimen was diagnosed as third nymphal stage of Linguatula serrata

Phase Stability, Microstructure, and Mechanical Properties of Spark Plasma Sintered Nanocrystalline Boron-Doped AlCoFeMnNi High-Entropy Alloy

The microstructure and mechanical properties of mechanically alloyed and spark plasma sintered AlCoFeMnNi₋ₓB (x = 0, 0.5, 1, and 5 at. %) high-entropy alloys (HEAs) have been investigated. Boron-doped HEAs were synthesized using mechanical alloying up to 50 h of milling. Synthesized powders were then consolidated at 850, 900, and 950 °C for 10 min under a uniaxial pressure of 40 MPa using spark plasma sintering (SPS). A scanning electron microscope, which was equipped with energy dispersive spectroscopy (EDS), together with an optical microscope (OM) were used to analyze the microstructural evolution. X-ray diffraction analysis was used to differentiate the phases formed in the solution. The mechanical properties of the sintered specimens were analyzed using the shear-punch test (SPT). The fracture surface of the SPT samples was studied using SEM. Thermodynamic calculations revealed that by employing this process, it is possible to produce solid solution HEAs with a duplex FCC + BCC structure. It was shown that boron-doped AlCoFeMnNi high-entropy alloys contain some unique attributes. SPS at 900 °C for a sample with boron up to 0.5 at. % leads to the formation of an alloy with the highest shear strength. A further increase in the boron content in the boron-doped HEAs exhibited a decrease in the maximum shear strength. Finally, the correlations between the microstructural and mechanical characteristics of the sintered boron-containing high-entropy alloys are discussed