2,000 research outputs found
Efficacy of Hepatitis B Vaccination in Under Five-Year-Old Children in Iran: A Systematic Review and Meta-Analysis Study
Context: Hepatitis B viral infection, specially in children, is an unsolved global health issue. National and international vaccination programs, as the main means to prevent this infection, have been operating for years. This meta-analysis study was launched to investigate the vaccination efficacy in under five-year-old children in Iran. Evidence Acquisition: In this research, all national databases including, SID, Magiran, Iran medex, Iran doc, and Medlib, as well as international databases, including PubMed, Medline, and ISI were searched for published articles associated with evaluation of seroconversion rates after hepatitis-B vaccination in Iranian children. The search was performed in the Persian and/or English language and in under five-year-old children in Iran. The variance of each study was calculated using the binomial distribution formula. The results of studies were combined using random-effects meta-analysis model. Data were analyzed using STATA version 12. Results: In the present research, 11 studies, performed from 2000 to 2017, were investigated. The number of samples in these 11 studies were 3063 children (1592 males and 1471 females). In the studies, the efficacy range of the hepatitis-B vaccine in under five-year-old children in Iran was 89 (95 CI: 86 -93) with high heterogeneity (P value for heterogeneity was 0.001, I-2 = 92.9). Range of efficacy for males and females was 85 (95 CI: 78 to 91) and 88 (95 CI: 83 to 93), respectively. Conclusions: The hepatitis B virus (HBV) vaccination program in Iran seems to be highly effective although some questions, such as the effect of gender on responsiveness to vaccine and heterogeneity of different data, remain unclear
Timing performance of 30-nm-wide superconducting nanowire avalanche photodetectors
We investigated the timing jitter of superconducting nanowire avalanche
photodetectors (SNAPs, also referred to as cascade switching superconducting
single photon detectors) based on 30-nm-wide nanowires. At bias currents (IB)
near the switching current, SNAPs showed sub 35 ps FWHM Gaussian jitter similar
to standard 100 nm wide superconducting nanowire single-photon detectors. At
lower values of IB, the instrument response function (IRF) of the detectors
became wider, more asymmetric, and shifted to longer time delays. We could
reproduce the experimentally observed IRF time-shift in simulations based on an
electrothermal model, and explain the effect with a simple physical picture
A novel diblock copolymer of (monomethoxy poly [ethylene glycol]-oleate) with a small hydrophobic fraction to make stable micelles/polymersomes for curcumin delivery to cancer cells
Curcumin is a potent natural anticancer agent, but its effectiveness is limited by properties such as very low solubility, high rate of degradation, and low rate of absorption of its hydrophobic molecules in vivo. To date, various nanocarriers have been used to improve the bioavailability of this hydrophobic biomaterial. This study investigates the encapsulation of curcumin in a novel nanostructure of monomethoxy poly(ethylene glycol)-oleate (mPEG-OA) and its anticancer effect. Tests were done to determine the critical micelle concentration (CMC), encapsulation efficiency, drug-loading efficiency, and cytotoxicity (against U87MG brain carcinoma cells and HFSF-PI3 cells as normal human fibroblasts) of some nanodevice preparations. The results of fluorescence microscopy and cell-cycle analyses indicated that the in vitro bioavailability of the encapsulated curcumin was significantly greater than that of free curcumin. Cytotoxicity evaluations showed that half maximal inhibitory concentrations of free curcumin and curcumin-loaded mPEG-OA for the U87MG cancer cell line were 48 μM and 24 μM, respectively. The Annexin-V-FLUOS assay was used to quantify the apoptotic effect of the prepared nanostructures. Apoptosis induction was observed in a dose-dependent manner after curcumin-loaded mPEG-OA treatments. Two common self-assembling structures, micelles and polymersomes, were observed by atomic force microscopy and dynamic light scattering, and the abundance of each structure was dependent on the concentration of the diblock copolymer. The mPEG-OA micelles had a very low CMC (13.24 μM or 0.03 g/L). Moreover, atomic force microscopy and dynamic light scattering showed that the curcumin-loaded mPEG-OA polymersomes had very stable structures, and at concentrations 1,000 times less than the CMC, at which the micelles disappear, polymersomes were the dominant structures in the dispersion with a reduced size distribution below 150 nm. Overall, the results from these tests revealed that this nanocarrier can be considered as an appropriate drug delivery system for delivering curcumin to cancer cells. © 2014 Erfani-Moghadam et al
Thermal Behavior of Nanoclay Reinforced Ultraviolet Curable Epoxy Acrylate
This study related to preparation of UV curable epoxy nanoclay nanocomposite and investigation on
mechanical and thermal properties of their thin films. For achieving this UV-curable epoxy dimethacrylate
was synthesized by epoxy resin (EPIKOTE 828), methacrylic acid, triphenylphosphine (PPh3) as catalyst
and para-methoxy phenol (PMP) as inhibitor at 80 ºC for 2 hours (yield 99%). Formulation of UV curable
resin was achieved by 5% w/w benzophenone and N, N dimethylaminoethyl methacrylate. The resin was
reinforced by using 1-5% w/w modified nanoclay in total formulation. Synthesized resin was characterized
by FTIR spectroscopy and thermal behaviors of nanocomposites were evaluated by TGA and DSC analysis.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3521
Rate-dependent and antiarrhythmic reentrant tachycardia (AVNRT) effects of simvastatin in isolated rabbit atrioventricular nodal model
Background and purpose: Several previous studies have shown the direct and indirect effects of statins on supraventricular and ventricular arrhythmia. The purpose of the present study is to determine (1) whether Simvastatin modifies the rate-dependent properties of the AV node, (2) to what extent such changes are related to effect of Simvastatin on the basic properties of AV nodal conduction and refractoriness. Materials and methods: AV nodal refractoriness (AVERP & AVFRP) and rate dependency protocols Fatigue and Facilitation were used to assesse the electrophysiological properties of AV node. We used an isolated perfussed rabbit with AV nodal preparation in one group (N=8). The stimulation protocols were carried out during control phase and in the presence of various concentrations of Simvastatin (0.5 , 0.8 , 1, 3 ,10 μm). Results: Simvastatin in concentration-dependent manner successfully prolonged effective and functional nodal refractory period (AVERP & AVFRP). Also an increase in Wenckebach cycle length was observed. Simvastatin in high concentration (3,10 μm) increases the arrhythmia threshold. Various concentrations of simvastatin increased fatigue, but it reached to significant level only at 30 μM. Conclusion: Simvastatin has potential anti-AVNRT effects by elevating arrhythmia threshold and prolongation of nodal refractoriness
Effect of Current Frequency and Annealing on Magnetic Properties of [Co70Fe30]97Sn3 Nanowire Arrays
[Co70Fe30]97Sn3 alloy nanowire arrays have been fabricated by alternative current (ac) electrodeposition
of Co2+, Fe2+ and Sn2+ into anodic aluminum oxide (AAO) templates. The samples were deposited at current
frequency 50, 100, 200, 300, 400, 500, 800 and 1000 Hz, respectively. The structure and magnetic
properties of [Co70Fe30]97Sn3 nanowire arrays dependence on different current frequency were analyzed by
XRD and alternating gradient field magnetometer (AGFM). The X-ray diffraction patterns are shown an
amorphous structure of the[Co70Fe30]97Sn3 nanowires.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3535
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