67 research outputs found
Development and characterization of nanostructured pharmacosomal mesophases: An innovative delivery system for bioactive peptides
Purpose: To potentially enhance the bioavailability and extend the bioactivity effectiveness of Isoleucine-Proline-Proline (IPP, an antihypertensive bioactive peptide of dairy origin), a novel Lyotropic Liquid Crystalline Pharmacosomal Nanoparticle (LLCPNP) was synthesized, and its physicochemical and technological characteristics were studied. Methods: LLCPNPs precursors were developed using IPP and soy phosphatidylcholine via complex formation. Polarized light microscopy, small angle X-ray scattering, differential scanning calorimetry, dynamic light scattering and Fourier transform infrared spectroscopy were employed to characterize the physicochemical properties of the nanoparticles. The in-vitro release and its related mechanisms were also studied. Results: Fourier transform infrared spectroscopy confirmed the complexation between the components of LLCPNPs. Phase behavior evaluation by polarized light microscope showed the characteristic birefringent texture. These findings along with those of small angle X-ray scattering and differential scanning calorimetry proved the formation of lamellar LLCPNPs. These particles represented nanometric size (<100 nm), high incorporation efficiency (93.72%) and proper physicochemical stability during long-term storage. In-vitro studies demonstrated a sustained release behavior fitted to non-Fickian diffusion and Higuchi kinetic models. Conclusion: The present study results emphasized that LLCPNPs could be proposed as an unrivaled carrier to promote the bioavailability, stability and shelf-life of nutraceutical and biopharmaceutical formulations containing bioactive peptides
Determinants of medical tourism considering a geographical model: a case study of Iran
Background: Medical Tourism has received significant attention worldwide as the most remarkable phenomenon in the tourism industry. Medical Tourism was considered a medical tourist’s behavior concerning the push/pull factors and three fundamental flows to assess the BTD model (Birthplace-Transportation-Destination). The present study aimed to unearth determinable factors of medical tourism based on a geographical model named BTD in Iran.
Methods: Firstly, with 301 respondents and 11 expert judges, after literature review, item building, and some assessments, the primary checklist leads to 49 items. Two next steps, some processes were common, including sample-to-item ratio (10.12, 10.24), the Cronbach's alpha (over 0.81, 0.85-0.96), Bartlett's Test (both were significant), and KMO (0.896, 0.915). Finally, EFA in the first study and PCA in the second study were assessed and reported. In the third study, to check multicollinearity, the VIF (1.809-2.917), AVE (0.50-0.55), and CR (0.59-0.68) were calculated. Then, AVE was compared with SIC. Ultimately, SEM was conducted that the 3-factor model, especially without the Mahalanobis distance, indicates better results. The study is developed in five cities called Khorasan, Tabriz, Tehran, Fars, and Isfahan.
Results: Regardless of cost, other significant factors were recognized, including birthplace-related factors, transportation-related factors, and destination-related factors.
Conclusion: As can be seen, the construction and the push/pull factors surveyed to assess the BTD model covering all main flows were well defined. Meaningful statistical relationships support the internal and external validity of the multidimensional construct. Therefore, present results are functional for interested sectors, and researchers must not disregard the market
Multi-response Optimization of Grooved Circular Tubes Filled with Polyurethane Foam as Energy Absorber
The main objective of this research is to improvethe design and performance of the polyurethane foam-filled thin-walled aluminum grooved circular tubes using multi-response optimization (MRO) technique. The tubes are shaped with the inner and the outer circular grooves at different positions along the axis. For this aim, several numerical simulations using ABAQUS finite element explicit code are performed to study the energy absorption of these structures. The effects of the grooves distance, tube diameter, grooves depth, foam density, and tube thickness are investigated onthecrashworthiness parameters of grooved circular tubes. Finite-element analysis is performed along the lines defined by design of experiments (DOE) technique at different combinations of the design parameters. The MRO is carried out using the mathematical models obtained from response surface methodology (RSM) for two crashworthiness parameters termed as the specific energy absorption (SEA) and the crushing force efficiency (CFE). Finally, by analyzing all the design criteria including theabsorbed energy of tube, themass of tube, the mean crushing load, and the maximum crushing load, the optimal density of polyurethane foam and geometric parameters were obtained through both multi-objective optimization process and Pareto diagram. A comparison of the obtained results indicates the significance of grooves distance and the inner diameter of thetube as the most influential parameters
Crashworthiness investigation of multi-component conical absorber with spherical cap under free inversion process: experimental study and numerical simulation
In this article, in order to provide energy absorption in thin-walled conical tubes under the inversion process, a new model of a multi-component conical absorber with a spherical cap is presented. For this purpose, by creating edges, a conical tube with a long length is divided into smaller components with different lengths and diameters. When the tube is subjected to axial loading, the process of deformation and dissipate of energy in this energy absorber is divided into two stages. The first stage is deformation of the spherical cap and the second stage is free inversion of each part of the conical inside next part. In other words, free inversion is formed by curling the edge of the components and then moving the tube wall downward. Therefore, the loss of energy absorption occurs with the bending of the spherical cap, the curling of the components edge and the circumferential contraction in the tube wall of each component. In this study, by using numerical simulation ABAQUS software, the effect of geometrical parameters, including cap type, number of conical components and semi-apical angle, on crashworthiness characteristics of the multi-component conical tubes are investigated. Also, in order to investigate the accuracy of the numerical simulation, some experimental tests were performed, which have obtained acceptable results. The results show that the proposed absorber model can be a suitable alternative for energy absorbers under the progressive buckling process
Population genetic structure of 2 species from Caspian Sea (Rutilus frissi kutum and Rutilus rutilus) and 2 species from Persian Gulf and Oman Sea (Rachycentron canadum and Eleutheronema tetradactylum) using Molecular Marker
Population structure of 2 species in the Caspian Sea (Rutilus frissi kutum and Rutilus rutilus) and 2 species in the Persian Gulf and Oman sea (Rachycentron canadum and Polynemus Plebeius) were studid by using Microsatellite and RAPD. For this 210 specimens of kutum (Khoshkrud, Tonekabon, Gorganrud, Anzali Lagoon and Kura River mouth), 90 (Gorgan Bay, Anzali Lagoon and Volga), 184 of cobia (Bushehr, daier, Bandarabass, bazm, lengeh) and 235 of (Khozestan, Bushehr, Bandarabass and chabahar) were sampled. Genomic DNA was extracted of fin using the phenol-chloroform .The quantity and quality of DNA from samples were assessed by spectrophptometer and 1% agarose gel electro-phoresis. PCR was carried out using microsatellite and RAPD primers. PCR products were separated on 8% polyacrylamide gels that were stained using silver nitrate. Result showed that in kutum the average of expected and observed heterozygosity was 0.54 and 0.49 respectively. Significant deviations from Hardy-Weinberg expectations were observed almost in all of location (P≤0.01, (P≤0.05). Using Fst and Rst there was significant difference between locations (P≤0.01). In study of Rutilus rutiluscaspicu the average of expected and observed heterozygosity was 0.5 and 0.7 respectively. Fst didn t show significant difference between iranian locations (P≥ 0.01) but it was Significant between Iranian populations and Russian populations (P≤ 0.05). In cobia the average of expected and observed heterozygosity was 0.655 and 0.874 respectively. Significant deviations from Hardy-Weinberg expectations were observed almost in all of location (P ≤0.01, (P≤ 0.05)). Significant differences (P<0.01) weren't observed between Rst recorded in the same region specimens studied but were observed between Rst recorded in the different region specimens studied. In Polynemus Plebeius, the observed heterozygosity in the Bushehr and Bandar abbas (0.22±0.13) was the highest and in Chabahar the lowest (0.171±0.175).Key word: Population Genetic, Rutilus frissi kutum ,Rutilus rutilus, Caspian Sea, Rachycentron canadum , Polynemus Plebeius, Persian Gulf and Oman sea
A Novel Electrochemical Flow-Cell for Operando XAS Investigations On X-ray Opaque Supports
Improvement of electrochemical technologies is one of the most popular topics
in the field of renewable energy. However, this process requires a deep
understanding of the electrode electrolyte interface behavior under operando
conditions. X-ray absorption spectroscopy (XAS) is widely employed to
characterize electrode materials, providing element-selective oxidation state
and local structure. Several existing cells allow studies as close as possible
to realistic operating conditions, but most of them rely on the deposition of
the electrodes on conductive and X-ray transparent materials, from where the
radiation impinges the sample. In this work, we present a new electrochemical
flow-cell for operando XAS that can be used with X-ray opaque substrates, since
the signal is effectively detected from the electrode surface, as the radiation
passes through a thin layer of electrolyte. The electrolyte can flow over the
electrode, reducing bubble formation and avoiding strong reactant concentration
gradients. We show that high-quality data can be obtained under operando
conditions, thanks to the high efficiency of the cell from the hard X-ray
regime down to 4 keV. We report as a case study the operando XAS investigation
at the Fe and Ni K-edges on Ni-doped maghemite films, epitaxially grown on Pt
substrates. The effect of the Ni content on the catalytic performances for the
oxygen evolution reaction is discussed.Comment: 11 pages, 9 figures, available supporting informatio
Survival of Patients with Malignant Pleural Effusion: A Single Center Study
Malignant pleural effusion is one of the most common complications of advanced malignancies, leading to decreased quality of life and life expectancy. With the advent of new therapies, patients with malignant pleural effusion appear to be living longer than previously thought. In this cohort study,26 patients, with malignant pleural effusion at the initial diagnosis of primary cancer, who were referred to the Lung Cancer Clinic of Shahid Motahari Clinic affiliated with Shiraz University of Medical Sciences , were studied Information on age, sex, tumor type, mortality, survival rate after malignant pleural effusion, EGFR mutation (in lung cancer patients), and metastasis were evaluated. In the present study, 12 patients (46.2%) were male and 14 patients (53.8%) were female. The median survival of patients was 2 years (interquartile range 1-3 years). Five patients (19.2%) had breast cancer, 19 patients (77.1%) had lung cancer, and two patients (7.7%) had lymphoma. The highest survival after diagnosis was related to one of the lymphoma patients (five years). In lung and breast cancer patients, the median survival was two years (interquartile range 1.5, 3) and one year (interquartile range 1, 2.5), respectively. Although the present study was a small single-center study, due to the appropriate lifespan of malignant pleural effusion patients with new therapies, more comprehensive studies are needed to re-evaluate the survival of patients with malignant pleural effusion
Impact of a PEO-based Interphase at the Negative Electrode of “Zero Excess” Lithium-Metal Batteries
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