86 research outputs found
Production of Gelatin Nanoparticles by Solvent Dissolution Method for Use as Food-grade
Introduction
 Gelatin is one of the most widely used colloidal proteins, which has unique hydrocolloidal property. Gelatin is derived from collagen by changing the thermal nature. This product is widely used in food, pharmaceutical, biomedical, cosmetic and photography industries. Global gelatin demand for food and non-food products is increasing. Two important properties of nanoparticles are: Increasing the surface-to-volume ratio of nanoparticles causes the atoms on the surface to have a much greater effect on their properties than the atoms within the particle volume. The effects of quantum size, which is the second feature. Methods for preparing nanoparticles from natural macromolecules: In general, two major methods for making protein nanoparticles have been reported Emulsion-solvent evaporation method and sedimentation or phase separation method in aqueous medium. Numerous methods have been reported for the preparation of nanoparticles from natural macromolecules. The first method is based on emulsification and the second method is based on phase separation in aqueous medium. In the first method, due to the instability of the emulsion, it is not possible to prepare nanoparticles smaller than 500 nm with a narrow particle size distribution. Therefore, coagulation method or anti-solvent method which is based on phase separation was proposed to prepare nanoparticles from natural macromolecules.
Â
Materials and Methods
 Type B (cow) gelatin was purchased from processing company with Bloom 260-240 food and pharmaceutical Iran solvent gelatin solution of 25% aqueous acetate glutaraldehyde from Iran Neutron Company. Two-stage anti-solvent method was used to produce gelatin nanoparticles. Then, to form nanoparticles, acetone was added dropwise while stirring until the dissolved acetone begins to change color and eventually turns white, which indicates the formation of nanoparticles. Finally, glutaraldehyde solution was added for cross-linking and finally centrifuged.
Â
 Results and Discussion
 The results showed that with increasing gelatin concentration, nanoparticle size and PDI increased significantly. According to the announced results, the solvent has a direct effect on the size. Therefore, the best mixing speed is determined to achieve the smallest particle size. Zeta potential is the best indicator for determining the electrical status of the particle surface and a factor for the stability of the potential of the colloidal system because it indicates the amount of charge accumulation in the immobile layer and the intensity of adsorption of opposite ions on the particle surface. If all the particles in the suspension are negatively or positively charged, the particles tend to repel each other and do not tend to accumulate. The tendency of co-particles to repel each other is directly related to the zeta potential. Fabricated gelatin nanoparticles have a stable structure, and are heat resistant. These nanoparticles are ready to be used to accept a variety of aromatic substances, compounds with high antioxidant properties, a variety of vitamins and heat-sensitive substances.
Â
Conclusion
The results of this study showed that the optimal conditions for the production of a particle of 88.6 nm at 40 ° C, the volume of acetone consumption was 15 ml, concentration 200 mg and speed 1000 rpm, and the morphology of gelatin nanoparticles have resistant, spherical polymer structure and mesh with a smooth surface that can be clearly seen under an electron microscope
Lipid-modifying effect of vitamin D fortified products: A systematic review and meta-analysis of Randomized Controlled Trials
Objectives: Various fortification strategies have been proposed to account to treat or prevent vitamin D deficiency. However, the optimum fortification approach, and the effect of these on health is not widely understood. There have been controversial reports regarding the effect of vitamin D fortification on the lipid profile. The aim of present review is the evaluation of administration of vitamin D fortified products on lipid profile.Methods: We used databases including PubMed/Medline, ISI Web of Knowledge, Science Direct, Scopus and Cochrane Library. A search was conducted until 2020 Randomized controlled trials that have assessed the relationship between consumption of vitamin D fortified products and serum lipid profile were included. The relationship between fortification dose, dairy or non-dairy fortification as well as duration of intervention and plasma lipid profiles evaluated in separate sub-groups.Results: Among serum lipids including total cholesterol(TC), triglyceride(TG), low density lipoprotein(LDL) and high density lipoprotein(HDL), fortification of vitamin D was reported to have a significant effect on reducing total cholesterol (pooled estimate: -0.089 mmol/L, 95%CI: -0.134 to -0.044, p<0.001). Its effect on other lipid profiles were not significant (LDL pooled estimate:-0.115 mmol/L, 95%CI:-0.238 to 0.008; HDL pooled estimate:0.024 mmol/L, 95%CI:-0.024 to 0.071; TG pooled estimate:-0.176mmol/L, 95%CI:-0.499 to 0.148).Conclusion: This meta-analysis demonstrated that vitamin D fortification could significantly reduce TC both in long and short term interventions and in different products. However this reduction, whilst statistically significant, may not be clinically important. The effect of fortification on other lipid profile components vary depending on dose and duration
Determination of Interleukin-6 and Tumor Necrosis Factor-alpha concentrations in Iranian-Khorasanian patients with preeclampsia
BACKGROUND: Our objective was to determine the role of Interleukin-6 (IL-6) and Tumor Necrosis Factor-alpha (TNF-alpha), markers of immune activation and endothelial dysfunction, in patients with preeclampsia. METHODS: Twenty four women with preeclampsia and eighteen antepartum normotensive pregnant women were recruited as controls. Serum levels of IL-6 and TNF-alpha were measured by enzyme-linked immunosorbent assay. We used independent-samples t test to assess the differences in the concentration of cytokines in preeclamptic patients and control subjects. RESULTS: IL-6 levels [mean (S.D.)] were significantly higher in preeclamptic women [5.8 (4.85) pg/ml] compared to normal pregnant women [3.01 (2.45) pg/ml] (p = 0.02). There was no significant change in concentration of TNF-alpha in preeclamptic women [53.8 (30.0) pg/ml] compared to normal pregnant women [51.9 (33.8) pg/ml] (p > 0.1). CONCLUSION: The results of this study show that IL-6 as a pro-inflammatory cytokine is present in higher concentration in women with preeclampsia. The study was undertaken in women with established preeclampsia and it is not possible to determine whether the increased concentration of IL-6 is a cause or consequence of the disease. Furthermore, these findings suggest that serum TNF-alpha level is not associated with preeclampsia
Antifouling properties of novel PSf and TNT composite membrane and study of effect of the flow direction on membrane washing
Antifouling properties of the polysulfone (PSf) and titanium nanotube (TNT) mixed matrix ultrafiltration membrane were investigated. The membrane was prepared by phase separation process using different concentrations of TNT and PSf. The pure water flux, protein removal and fouling parameters were studied to analyze the performance of the membrane. Morphology of the membrane was characterized by using scanning electron microscopy and atomic force microscopy. The most prominent observation was the significant improvement in water flux which attributed to improved hydrophilicity. The improvement of hydrophilicity was confirmed by water contact angle measurement and porosity measurements. This improvement in hydrophilicity is because of hydroxyl group present on TNT as determined by ATR-IR spectra. Fouling resistance of the membranes assessed by BSA solution filtration showed that 0.3 and 0.5 wt.% TNT loading membrane exhibited the best antifouling property that resulted in 100% flux recovery. The results also showed that 0.3 wt.% TNT loading membrane possessed the highest mean pore radius, porosity, and water flux. The effect of different washing directions in fouling experiment was reported. The perpendicular washing and parallel washing were carried out during fouling experiment and effects were discussed. The TNT nanocomposite membrane with parallel washing showed significant reusability during filtration
A survey on the quality of Master of Medical Education e-learning Course at Mashhad University of Medical Sciences
Introduction:Universities and educational institutes provide a great variety of e-learning programs to accommodate the increasing demands for higher education. However, some specialists believe that many of these courses fail to meet the required standards of e-learning, thus cannot achieve the goals of implemented programs. Therefore, regular quality assessment of e-learning programs should be carried out by education providers. This study aimed to assess the quality of medical education e-learning course at Mashhad University of Medical Science.
Methods:In the first step, most important components of e-learning standards were extracted through a comprehensive literature review of previous studies and a rating scale consisting of nine elements and 173 items were designed. Content validity of the scale was assured by consulting with ten different instructional design experts using Lawshe's Content Validity Ratio. Reliability of this scale is also investigated by inter-rater reliability coefficient which was 88% . In the next step we provided three instructional design experts with the above mentioned scale to collect required information for each sample lesson. Data was analyzed through SPSS Ver 16.0 software.
Result: The elements associated with ‘quality of contents’ and ‘accessibility’ were satisfactory, elements related to ‘instructional design’, ’learning management system’, ’multimedia’ and ‘student assessment’ were relatively satisfactory, and elements associated with ‘interaction’, ‘feedback’ and ‘student support’ were unsatisfactory. Overall, we evaluated the quality of the medical education e-learning course as relatively satisfactory.
Conclusion: Although the quality of the assessed e-learning course was relatively satisfactory, it is still necessary for corresponding administrators to reassess those items with an average of less than 1.66 (satisfactory level) and pay their special attentions to improvement of those items, in order to achieve better quality of the program
The potential of thin film nanocomposite membrane in reducing organic fouling in forward osmosis process
A major limiting factor of forward osmosis (FO) membrane, particularly in pressure retarded osmosis (PRO) mode, is fouling by natural organic matters. In this work, we investigated the effect of the nanocomposite substrate on the fouling of a thin film nanocomposite (TFN) membrane due to organic foulants in PRO mode. The TFN membrane was synthesized by coating a polyamide film over the surface of substrate made of polysulfone–titanium dioxide. The TFN membrane always showed much higher FO water flux than the typical thin film composite TFC membrane prepared from the pristine polysulfone substrate. Reduced internal concentration polarization following a significant decrease of the structural parameter in the nanocomposite substrate causes the mass transfer coefficient of the substrate to increase. In the PRO mode, BSA removal in the presence of Ca2 + confirmed that the TFN FO membrane could significantly mitigate fouling tendency compared to a typical TFC membrane. Results also showed that fouling in TFN FO is highly reversible, recovering > 92% permeate flux after a simple water rinse process. A complete study of the membrane fouling was reported with detailed scientific discussion. To the best of our knowledge, this is the first report on the effect of the nanocomposite membrane on membrane fouling in PRO mode
Preparation and characterization of a novel highly hydrophilic and antifouling polysulfone/nanoporous TiO 2
- …