435 research outputs found
Chemical components of marine sponge derived fungus fusarium proliferatum collected from Pulau Tinggi Malaysia (Komponen kimia kulat fusarium proliferatum diperolehi daripada Span Marin di Perairan Pulau Tinggi, Malaysia)
Marine fungus Fusarium proliferatum derived from marine sponge collected along Pulau Tinggi, Malaysia was cultivated on Potato Dextrose Broth and incubated for 7 days at 30oC. The liquid cultures were then extracted using ethyl acetate. The crude extract was investigated for its anti-microbial activity and was passed through Sephadex column and the fractions were collected. Reverse phase HPLC was used to monitor the component of crude extract. HPLC guided purification of crude extract resulted in the isolation of linoleic acid, 4-hydroxy phenethyl alcohol, 2,5-furandimethanol and adenosine. Their structures were elucidated by spectroscopic methods
Investigation of biofilm formation among methicillin-resistant Staphylococcus aureus isolated from children
Background: The aim of the present study was to investigate biofilm formation among Methicillin-resistant Staphylococcus aureus (MRSA) isolated from children referring to a pediatric hospital in Tehran. Methods: In total, 98 MRSA isolates were collected from children referring to a pediatric hospital during 2014 - 2015. All the isolates were confirmed to be MRSA using PCR amplification of the mecA gene. The antibiotic susceptibility patterns of the isolates were determined using the Kirby-Bauer disk-diffusion and E-test methods. In order to assess the ability of biofilm formation among the isolates, Congo red agar (CRA) and Microtiter Plate (Mtp) methods were used. Results: All the isolates were found to be susceptible to linezolid and vancomycin and, likewise, the majority was susceptible to minocycline and rifampicin. CRA and Mtp methods showed that 81.6 and 63.3 of the MRSA isolates, respectively, were biofilm producers. Conclusions: The early identification of S. aureus and detection of biofilm formation by the Mtp method are essential steps towards the prevention of the most serious nosocomial infections. © 2017, Archives of Pediatric Infectious Diseases
Investigation of biofilm formation among methicillin-resistant Staphylococcus aureus isolated from children
Background: The aim of the present study was to investigate biofilm formation among Methicillin-resistant Staphylococcus aureus (MRSA) isolated from children referring to a pediatric hospital in Tehran. Methods: In total, 98 MRSA isolates were collected from children referring to a pediatric hospital during 2014 - 2015. All the isolates were confirmed to be MRSA using PCR amplification of the mecA gene. The antibiotic susceptibility patterns of the isolates were determined using the Kirby-Bauer disk-diffusion and E-test methods. In order to assess the ability of biofilm formation among the isolates, Congo red agar (CRA) and Microtiter Plate (Mtp) methods were used. Results: All the isolates were found to be susceptible to linezolid and vancomycin and, likewise, the majority was susceptible to minocycline and rifampicin. CRA and Mtp methods showed that 81.6 and 63.3 of the MRSA isolates, respectively, were biofilm producers. Conclusions: The early identification of S. aureus and detection of biofilm formation by the Mtp method are essential steps towards the prevention of the most serious nosocomial infections. © 2017, Archives of Pediatric Infectious Diseases
Toxin production and drug resistance profiles of pediatric methicillinresistant Staphylococcus aureus isolates in Tehran
OFDR based distributed temperature sensor using the three-channel simultaneous radio-frequency lock-in technique
Factors influencing patient satisfaction with dental appearance and treatments they desire to improve aesthetics
Background: We assessed factors influencing patients’ satisfaction with their dental appearance and the
treatments they desired to improve dental aesthetics.
Methods: A cross-sectional study was performed out among 235 adult patients who visited the Hospital Universiti
Sains Malaysia dental clinic. A structured, interviewer-guided questionnaire was used to identify patient satisfaction
with their general dental appearance, cosmetic elements and desired treatments.
Results: The 235 patients consisted of 70 males (29.8%) and 165 females (70.2%), of mean age 31.5 years (SD 13.0).
Of these patients, 124 (52.8%) were not satisfied with their general dental appearance. In addition, 132 patients
(56.2%) were not happy with the color of their teeth, 76 (32.3%), regarded their teeth were poorly aligned, 62
(26.4%), as crowded and 56 (23.4%) protruded. Dissatisfaction with tooth color was significantly higher in female
than in male patients (odds ratio [OR] of 1.99 (95% confidence interval [CI] 1.13-3.50). Tooth whitening was the
treatment most desired by patients (48.1%). Results of multiple logistic regression analysis showed that patient
dissatisfaction with general dental appearance was significantly associated with female gender (OR = 2.18; 95% CI:
1.18-4.03), unhappiness with tooth color (OR = 3.05; 95% CI: 1.74-5.34) and the opinion that their teeth protruded
(OR = 2.91, 95% CI: 1.44-5.91)
Rheological, physicochemical, and microstructural properties of asphalt binder modified by fumed silica nanoparticles
Warm mix asphalt (WMA) is gaining increased attention in the asphalt paving industry as an eco-friendly and sustainable technology. WMA technologies are favorable in producing asphalt mixtures at temperatures 20–60 °C lower in comparison to conventional hot mix asphalt. This saves non-renewable fossil fuels, reduces energy consumption, and minimizes vapors and greenhouse gas emissions in the production, placement and conservation processes of asphalt mixtures. At the same time, this temperature reduction must not reduce the performance of asphalt pavements in-field. Low aging resistance, high moisture susceptibility, and low durability are generally seen as substantial drawbacks of WMA, which can lead to inferior pavement performance, and increased maintenance costs. This is partly due to the fact that low production temperature may increase the amount of water molecules trapped in the asphalt mixture. As a potential remedy, here we use fumed silica nanoparticles (FSN) have shown excellent potential in enhancing moisture and aging susceptibility of asphalt binders. In this study, asphalt binder modification by means of FSN was investigated, considering the effects of short-term and long-term aging on the rheological, thermal, and microstructural binder properties. This research paves the way for optimizing WMA by nanoparticles to present enhanced green asphalt technology
Polyaniline/palladium nanohybrids for moisture and hydrogen detection.
Palladium nanoparticles display fascinating electronic, optical and catalytic properties, thus they can be used for various applications such as sensor fabrication. Conducting polymers such as polyaniline have also been widely used in sensor technology due to its cost effectiveness, versatility, and ease of synthesis. In this research, attention was given to unify the exceptional properties of these two materials and construct palladium nanoparticle coated polyaniline films to detect hydrogen and moisture. Electrochemical polymerization of aniline was carried out on gold sputtered epoxy resin boards. Polyaniline film was generated across a gap of 0.2 mm created by a scratch made on the gold coating prior to electrochemical polymerization. A palladium nanoparticle dispersion was prepared using sonochemical reduction method and coated on to polyaniline film using drop-drying technique. Polyaniline only films were also fabricated for comparative analysis. Sensitivity of films towards humidity and hydrogen was evaluated using impedance spectroscopy in the presence of the respective species. According to the results, polyaniline films exhibited an impedance drop in the presence of humidity and the response was significantly improved once palladium nanoparticles were incorporated. Interestingly, polyaniline only films did not respond to hydrogen. Nevertheless, palladium nanoparticle coated polyaniline films exhibited remarkable response towards hydrogen
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