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Background: Leptospirosis has been recognized as an important reemerging infectious disease caused by pathogenic Leptospira spp. A major challenge of this disease is the application of a basic research to improve diagnostic method. Outer membrane proteins of Leptospira are potential candidates that could be useful in diagnosis. Among them the lipL41 is an immunogenic protein which is present only in pathogenic serovars. In order to evaluate genetic conservation of the lipL41 gene, we cloned and sequenced this gene from Leptospira interrogans serovar Canicola.
Materials and Methods: Following the DNA extraction from the serovar, the lipL41 gene was amplified and cloned into pTZ57R/T vector and transformed into the competent E. coli (Top10). Recombinant clones were confirmed by colony PCR and DNA sequencing. The related sequences were then analyzed and compared with the sequences in the Genbank database.
Results: PCR amplification of the lipL41 gene resulted in a 1065 bp PCR product. The PCR based on the lipL41 gene detected all the pathogenic reference serovars of the tested Leptospira spp. It was revealed that in Iran the homology of the lipL41 gene between vaccinal and clinical serovars of Canicola was 100%. It also showed >95.9% homology with other pathogenic serovars in Genbank database, which indicates genetic conservation of this gene.
Conclusion: Because of the conservation of lipL41 gene among different strains of Leptospira and its exclusive presence in leptospira, it was revealed that the cloned gene could be further used as a good candidate for developing diagnostic methods such as ELISA and as positive control in diagnostic PCR.

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In this study, the three phase mixed matrix membranes comprising Pebax®1657, PEG-200 and MIL-53(AL) nanoparticles were evaluated for CO2 gas separation. The effect of various PEG-200 and MIL-53(AL) concentration within the pebax polymeric matrix on the structure, gas permeability, and selectivity of the membranes was investigated. To study the cross-sectional morphology, crystallinity and thermal properties of the synthesized membranes, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were utilized, respectively. Fourier transform infrared (FT-IR), was also carried out to identify the formation of the chemical bonds in the membrane. SEM images demonstrated a uniform cross-section and admissible dispersion of nanoparticles. The results of the thermal analyses indicated an increase in crystallinity and Tg in presence of MIL-53 particles. Permeation of pure gases (i.e., CO2, CH4) through the prepared neat Pebax®1657, the blended Pebax/PEG-200 and the Pebax/PEG-200/MIL-53(AL) mixed matrix membrane was measured at the pressure of 2–10 bar and temperature of 30 °C. The results showed that at the pressure 10 bar, the CO2 gas permeation from 133.36 barrer in pure membrane increased to 311.7 barrer (134%) in a membrane containing 10%wt MIL-53.
 

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Research subject: Selectivity and permeability are the major parameters of polymeric membranes in gas separation process. Hence, nowadays in order to improve aforementioned parameters, modification and enhancement issues for such membrane have been highly noticed.
Research approach: In this study, in order to improve the performance of polymeric membranes, the two-component blend membranes containing Pebax^®1657 and PVA were synthesized for CO₂ separation. The effect of different PVA concentrations within the Pebax matrix on structure, morphology and gas separation properties of resultant membranes was investigated. The chemical bonds, crystallinity and cross-sectional morphology studied through, Fourier transform infrared (FTIR), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), and were utilized.
Main results: The results of the thermal analysis indicated an increase in crystallinity and also glass transition temperature in presence of 5 – 15 wt.% PVA, while the membrane crystallinity decreased by increasing the PVA content up to 20 wt.%. FESEM images demonstrated a uniform cross-section without any cracks and defects for neat Pebax membrane but by adding PVA to Pebax matrix, appeared cracks and cave structures on the cross- section of blend membranes. The CO₂/CH₄ separation performance of membranes was measured using a constant volume set up at 30°C and feed pressure of 2, 6 and 10 bar. The obtained results revealed that the CO₂ permeability in blend membranes improved as the PVA content increased within the membrane. The best obtained CO₂ permeability was 204.64 Barrer which gained by Pebax/PVA (20wt.%) at feed pressure of 10 bar. Moreover, the highest selectivity of CO₂/N₂ for blend membrane with 15 wt.% of PVA was about 100.21 at 10 bar and 30°C.
 

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Research subject: In recent years, researchers have proposed various methods for gas separation because of rising greenhouse gases in the atmosphere and causing enormous environmental problems. One of the newest and emerging methods is membrane gas separation. In the last decade, mixed matrix membranes (MMMs) have received much attention due to their ability to successful separation of polar gases from mixtures.
Research approach: In this study, a novel two-component mixed matrix membrane was prepared by incorporating the nickel zinc iron oxide nanoparticles into the Pebox polymer matrix. This is owing to combination the unique features of Pebax copolymer such as high mechanical strength and gas permeability, with nanoparticle properties as considerable permeability and selectivity, and appropriate mechanical and thermal stability. The gas permeability test was performed for pristine membrane and MMMs at 35 °C and pressure range from 2 to 10 bar. Fabricated membranes were also evaluated by FESEM, FTIR-ATR, DSC and XRD tests
Main results: Results demonstrated that in the case of the optimum membrane with 1 wt.% of filler loading and at 10 bar, the CO₂ permeability was increased about 128% and reached to 278 Barrer, compared to pristine membrane. However, the CO₂/CH₄ and CO₂/N₂ selectivities were improved by 175 and 183 percent, respectively. This superior results was due to the presence of iron, nickel, and zinc atoms in the filler structure, which resulted in a better interaction with CO₂. On the other hand, the presence of CO₂-friendly segments in the Pebax structure caused much higher CO₂ permeability in comparison with other light gases.

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Nowadays, biological substances have allocated many applications to themselves in distinct industries. In this field, biological molecules with various potentials have been identified, from which we can refer to bacteriorhodopsin (BR). Bacteriorhodopsin is found in purple membrane of halobacterium salinarum. Due to its stability and various characteristics like possession of properties of a proton pump, bacteriorhodopsin has many applications in different industries. One of the most important industrial and semi-industrial production processes for bacteriorhodopsin is the isolation and purification of the purple membrane. In this investigation, after halobacterium salinarum culture, the purification was done according to the Yucel method. So as to produce bacteriorhodopsin in semi-industrial scale, a modified method was developed by substitution of mechanical approach with enzymatically method to destruction of DNA and uses of osmotic shock instead of dialyze. This method led to decrease of time and isolation cost in comparison to Yucel method. The contamination percentage of the PM was estimated below 5% for both methods. The purification percentages were 67±1% and 68±4% for the modified method and Yucel method, respectively, which is indicating of the equal purification percentage for both methods. Bacteriorhodopsin amount was 8.2±0.4, 8.1±0.6 mg per liter for the improved method and Yucel method, respectively. The enzyme activity assay by Kuyama method indicated that the pH variation was 1 unit with the same BR amount for both methods. Hence, the modified method introduced in this investigation could reduce time and costs of the purification by maintaining the BR characteristics.

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Abstract
Research subject: In recent years, many efforts have been made to improve the performance of polymer membranes in oxygen-nitrogen separation due to the high cost and energy consumption of cryogenic distillation and adsorption methods. Increasing the performance of these types of membranes is still needed for industrial applications.
Research approach: In this research, novel magnetic mixed matrix membranes (MMMs) were prepared using polysulfone (PSf) as the main matrix, and also neodymium (Nd) as the magnetic particles for O₂/N₂ separation. To avoid the particle sedimentation and proper dispersion of particles across the membrane thickness, magnetic particle dispersion in the PSf was controlled by applying an external magnetic field (MF). The effect of Nd magnetic particle content on the microstructure, magnetic properties and thermal stability of the prepared MMMs were investigated using scanning electron microscopy, vibrating sample magnetometer and thermo-gravimetric analysis. In this reseach, a novel magnetic module was designed and constructed to investigate the performance of prepared membranes in the presence of various MFs.
Main Results: The obtained results indicated that the permeability of O₂ and N₂ gases was improved by adding Nd magnetic particles into PSf matrix regardless of the amount of MF due to the chain packing of polymers disruption and free volume enhancement. The permeability of O₂ and N₂ in the MMMs containing 5 wt.% Nd in the absence of MF was about 182 % and 443%, respectively, higher than those of neat PSf membranes. Furthermore, the permeability and selectivity of PSf and PSf-Nd membranes were considerably improved by applying the MF during the permeation experiments. In the MMMs containing 5 wt.% Nd, O2/N2 selectivity was increased from 2.73 to 3.77 upon an increase in the intensity of MF from 0 to 570 mT. Considering the findings, the application of Nd particles and MF during the membrane preparation and separation processes can be facile methods for enhancement of membrane performance.
 
Keywords: Oxygen/nitrogen separation; Polysulfone; Neodymium; Magnetic mixed-matrix membranes; Magnetic separation module
 

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The molecular characteristics of Yersinia ruckeri such as total proteins (TP), outer membrane proteins OMP) and lipopolysaccharides (LPS) in 34 isolates from rainbow trout farms in Tehran, Mazandaran and Zanjan provinces were determined, using SDS-PAGE method. The molecular weight (MW) for TP of all bacterial isolates was mostly less than 100 KD with a banding density in range 28 to 100 KD. Also, protein pattern of OMP consisted of three major bands with MW of 28-35 KD (two bands) and 10-17 KD (one band) plus some minor bands with MW of 48-75 KD and 17-28 KD. In addition, the LPS pattern of all bacterial isolates were less than 130 KD with the most band density in range 28-100 KD. These results show that the banding profile of TP, OMP and LPS of all isolates of Y. ruckeri were identical, demonstrating minimum heterogeneity among Iranian isolates of Y. ruckeri. Therefore, it is feasible for the formulation of a monovalent vaccine to yersiniosis in future.

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In recent years, air separation using membranes has received much attention as a cost-effective technology for producing relatively pure streams of nitrogen and oxygen. The results of studies show that the design and fabrication of new polymers with the desired structure for the industrialization of polymer membrane technology in the field of oxygen separation from nitrogen is considered very important. The results obtained from various research works show that polymer membranes made on the basis of aromatic polyimides and PIMs due to high selectivity, suitable mechanical, thermal and chemical properties and also benefiting from different structures due to polymer substitutions are a suitable option for separation of oxygen and nitrogen. Moreover, the membrane modification process can greatly increase the mechanical, chemical and selectivity of the membranes and be an effective way to improve the separation of oxygen from nitrogen. The results indicate that the fabrication of blended membranes has increased the selectivity and permeability of the membranes, and the creation of transverse connections in most cases has increased the selectivity of the membranes. Meanwhile, carbon molecular sieve membranes that are made by thermal decomposition of the polymeric raw material under controlled temperature and pressure conditions due to their properties such as high selectivity and permeability, stability in corrosive environments and applicability at high temperatures are suitable options for separation of oxygen and nitrogen. Also, carefully in the results obtained from various research works, it can be seen that the use of driving force and magnetic particles in the polymer simultaneously improves the permeability and selectivity of membranes. As it is predicted, this method is one of the efficient methods in improving the performance of polymer membranes in the field of oxygen and nitrogen separation.

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Research subject: Osmosis membrane bioreactor is one of the best industrial wastewater treatment methods. The main advantage of using osmosis process is its operation at low hydraulic pressures which has a better performance in removing pollutants and low energy consumption than other methods                        
Research approach: In this research, Nano porous Titanium dioxide powder with a specific surface area and anatase wall was synthesized through a thermal process using cetyltrimethylammonium bromide (CTAB) as a surfactant directing agent and a pore-creating agent.Ultrafiltration nanocomposite membranes were made using modified titanium dioxide (TiO₂) (MT) and polysulfone (PSf) by phase the inversion method. The morphology and structure of the prepared membranes and nanoparticles were investigated using by atomic fourier transforms infrared spectroscopy(FESEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). In this research, bovine serum albumin (BSA) was used as simulated wastewater for the feed solution. The fabricated ultrafiltration membranes were tested in osmosis membrane bioreactor (OMBR) system due to lower energy and fouling. 0.6 % solution of poly (sodium 4-styrene sulfonate) was used as an osmotic solution. Comparative separation performance and antifouling properties of both nanocomposites in several analyzes such as water contact angle measurement, pure water flux and filtration of different concentrations of bovine serum albumin solution. BSA and fouling resistance have been investigated


Main results:  TThe results that Due to the addition of MT nanoparticles to the polymer matrix, the hydrophilicity and surface energy of the membrane increased, which led to the improvement of the membrane performance. The membrane containing 1% titanium oxide nanoparticles showed the best result. For example, for feeding with a concentration of 200 ppm, the water flux increased from 20 to 38.5 L/ m² h, and the percentage of returning lethal solution decreased from 19.6 to 30 g/ m² h. The flux recovery in this membrane was 96%, which indicates the antifouling property of the modified nanocomposite membrane.                                                                
              

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Research subject: Permeability and high selectivity are two important factors of gas separation membranes. To achieve such parameters, gas separation membranes can be modified and improved in terms of material type, material ratio, structure, and etc. For this purpose, in this research, the performance of chitosan-gallic acid/polysulfone thin film composite membranes (TFC) has been improved in CO₂ gas separation.
Research approach: To prepare chitosan-gallic acid/polysulfone TFC membranes, a nanometer-scale thin layer of chitosan-gallic acid was formed on the polysulfone support layer (PSF). Following this, chitosan-gallic acid composite thin layer membranes were synthesized with different mass ratios (1:1, 2:1, and 1:2). Various analytical techniques, including Fourier Transform Infrared Spectrometer (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and X-ray Photoelectric Spectroscopy )XPS(, were used to examine the structure of the TFC membranes, alongside CO₂/CH₄ and CO₂/N₂ separation tests.
Main results: Examining the chemical structure of the synthesized membranes showed the successful formation of chitosan-gallic acid chains on the PSF surface. The microscopic images of the synthesized membranes showed that a dense thin layer of chitosan-gallic acid was uniformly formed on the PSF support layer. The highest CO₂ separation was achieved with a chitosan-gallic acid mass ratio of 1:2. Increasing the gallic acid content in the selective layer of the thin film composite membrane resulted in improved CO₂ permeability, increasing from 294.4 GPU and 347.2 GPU for the 1:1 and 2:1 membrane, respectively, to 411.1 GPU for the 1:2 membrane. Additionally, the permeability of CH₄ and N₂ gases through the thin film composite (1:2) membrane was measured at 24.6 GPU and 19.2 GPU, respectively. The gas selectivity calculations revealed an increase in selectivity for CO₂/CH₄ and CO₂/N₂, rising from 13.84 and 17.165 in the 1:1 membrane and 9.684 and 12.969 in the 2:1 membrane to 16.711 and 21.411 in the 1:2 membranes. The results showed that the performance of the chitosan-gallic acid thin layer membrane, which was used for the first time in CO₂ separation, was acceptable.
 

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Research subject: Membranes and membrane processes have gained significant importance in recent decades, particularly in industries such as water treatment, oil processing, gas separation, and desalination. Among these, ceramic membranes are increasingly preferred due to their outstanding properties, including high mechanical, chemical, and thermal stability, suitable porosity, and high permeation flux. This study focuses on examining the characteristics of alumina ceramic suspensions used in the gel-casting method for fabricating ceramic membranes.
Research approach: This research investigates the influence of polysaccharide compounds as organic additives and binders in the fabrication of ceramic membranes. To optimize the microstructure, the study explores the rheological behavior and gelation time (chemo-rheology) of alumina ceramic powder–polysaccharide suspensions. Key parameters—including temperature, the presence or absence of ceramic powder, and the concentrations of cross-linking agent and binder—were systematically analyzed for their effects on gelation time. Additionally, the microstructure of the final membranes was evaluated using scanning electron microscopy (SEM).
Main results:The results demonstrated that the alumina–polysaccharide system, combined with an aldehyde-based cross-linking agent, is a promising approach for producing complex and robust ceramic green bodies. It was found that at ceramic powder loadings higher than 30 vol%, an increase in temperature by 5–10 °C, along with a two- to threefold increase in the contents of the polysaccharide binder and aldehyde-based cross-linking agent, significantly reduced the gelation time. These findings underscore the critical importance of precisely controlling parameters such as temperature and additive concentrations at a given ceramic powder loading to achieve optimal membrane properties.

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Aims: Today, due to the advent of drug resistance in cancer cells against conventional drugs, attention has been paid to the development of anti-cancer drugs with new mechanisms. Pardaxin is an amphipathic polypeptide neurotoxin.The aim of this study was to investigate the interaction of antimicrobial peptide pardaxin with DPPC (composed of 1, 2-dipalmitoyl-sn-glycero-3-phosphocholine) bilayers by molecular dynamics simulation.
Materials & Methods: In the present study, simulations for different membrane environments were designed under neutral pH conditions. At first, the Linux system was used to install the VMD 1.8.6 (Visual Molecular Dynamics) software; then, Gromacs 4.5.5 software was used to perform all the simulations. The pdb peptide structure (1XC0) was prepared from the Protein Data Bank and DPPC lipid bilayer was used for lipid-peptide simulation.
Findings: During the 500 nanoseconds of simulation, the peptide was infiltrated into the membrane. In the DPPC system, at first, the number of hydrogen bonds between the peptide and the lipid bilayer were increased and, then, remained almost constant until the end of the simulation and decreased over time with the number of hydrogen bonds between peptides and water. Pardaxin contacted with the membrane surface and entered into the membrane. In the presence of the peptide, the thickness of the membrane and the range of each lipid decreased and the membrane penetration increased.
Conclusion: The mechanism of Pardaxin is dependent on the bilayer composition, so that the pardaxin peptide contacts with DPPC lipid membrane surface and enters into it.

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OmpF is one of the bacterial outer membrane protein which can transfer the ions into the membrane. During the last years different theoretical and experimental methods have been used for the investigation of the bacterial protein. In this study for retaining periodic boundary condition and investigation of the channel structural changes, we use double lipid bilayer in the system. Different ion concentration was applied into the lipid bilayers to make simulation much more realistic. The aim of this simulation is if there is any prominent direction in the ion passage of the channels. Structural analysis for two proteins with a different orientation is dissimilar and dssp analysis shows different peaks although there are common peaks. Lining residues and constriction zone amino acids in the two final frames are also diverse. There is no ion passage thorough protein 2. The results are completely different for the ion channels and it shows which after 100ns simulation one of the channels which its direction is similar to the natural channel in the bacterial membrane is open and the ion passage is clear and the other channel is completely closed which is related to the direction of the channel due to the ion concentration.

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The conditions for the refinement of clarified sugarcane juice, including temperature (50o, 60o and 70oC) and pressure (0, 0.5, 1 and 1.5 bars) by micro-filtration membrane technology were investigated. The raw sugarcane juice was initially pre-filtrated with lime and then the juice obtained (clarified juice) processed using a ceramic micro-filter mem-brane (0.2 micrometer). The characteristics investigated included brix, polarity (sucrose percent), turbidity, color and purity. The results showed that the effects of different proc-ess conditions with micro-filtration on reduction of turbidity and color were significant at probably <0.01 and probably <0.05, respectively. For other characteristics, no significant difference was observed. Finally, a temperature of 70oC and transmembrane pressure of 1.5 bar were determined as the optimum conditions for ceramic micro-filtration. Mem-brane processing at 70oC and 1.5 bars reduced the turbidity, viscosity and color of clari-fied juice 56.25%, 16.67% and 6.49%, respectively, and increased 0.87 units of purity.

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Background: Klebsiella pneumoniae (K. pneumoniae) is responsible for life-threatening infections, given that it is usually resistant to antibacterial drugs. Due to the restricted antibiotic options for the treatment of resistant K. pneumoniae infections and the critical role of humoral immune responses in preventing infectious diseases, the present in silico study aimed to investigate fimbriae (type 1 and type 3), outer membrane protein A (OmpA), and outer membrane protein K35 (OmpK35) to find appropriate epitopes for vaccine development.
Materials & Methods: Several independent bioinformatics servers including IEDB, ABCpred, VaxiJen, and EMBOSS were applied to identify appropriate linear epitopes (B-cell and T-cell).  Conformational epitopes were also predicted using Ellipro and Discotope programs. The Antigenic Peptide Prediction server was used to confirm the identified epitopes. Molecular characteristics, toxicity, human similarity, and allergenicity were investigated.
Findings: The results demonstrated that the investigated proteins were highly immunogenic. In the first step, 25 epitopes were identified in the investigated proteins. After applying different exclusion criteria, the final epitope of each investigated protein was selected. The final epitopes of fimbriae (type 1 and type 3), OmpK35 and OmpA were located in 28-49, 26-53, 271-291, and 288-299 regions, respectively. Allergenicity, toxicity, and human similarity were negative for the predicted epitopes.
Conclusion: The present study results introduced four reliable B-cell and T-cell epitopes (each for one investigated protein) with appropriate physicochemical characteristics. The proposed epitopes could be used in vaccine development against K. pneumoniae after further in vitro and in vivo studies.

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There is a full connection between the electrochemical quantities of a fuel cell and the curves of the temperature and primary materials at the catalyst region. These quantities are strongly linked to the mass and heat transfer phenomena in the other regions. In the present paper, the lattice-Bolzmann method, as a microscale model with good computational capabilities in the problems such as the fuel cell, has been utilized to simulate the fluids flow and heat transfer in a two-dimensional cross section of a proton exchange membrane fuel cell including the channel, bipolar plate, gas diffusion layer and catalyst of the cathode and the electrochemical characteristics in the catalyst layer have been analyzed. By representing a method for estimation of the changes in the concentration along the channel, the serpentine arrangement has been modeled. The results reveal the essential role of the bipolar plate on the quantities at the catalyst layer.

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Bacteria are used directly by zooplankton as a food source. The purpose of this study is to use straw as a substrate for the proliferation of bacteria in geomembrane pools and its effects on the production and biochemical compositions of Artemia. One week before Artemia culture, the pools inoculated with Dunaliella sp. and straw (particles less than 200 microns) as follows: treatment 1= geomembrane pool containing Dunaliella sp. (one week of algae cultivation), treatment 2 = geomembrane pool containing Dunaliella sp. and 0.5 grams per liter of straw (one-week algae cultivation and adding straw from the second week), treatment 3 = geomembrane pool containing Dunaliella sp. and 0.5 g/l of straw (algae cultivation and adding straw from the first week) and treatment 4= geomembrane pool containing 0.5 g/l of straw (adding straw from the first week). Artemia was cultured for 18 days and fed based on a turbidity depth of 15 cm. The highest growth rate was observed at the end of day 18 in treatment 3 (P<0.05). The highest amount of protein was obtained in treatment 1 (P<0.05). The highest amount of biomass was observed in the control and T3 groups (P<0.05). The presence of straw in Artemia pools decreased EPA fatty acid by 5-7 times less than the control (P<0.05). Artemia can grow while feeding on environmental bacteria. Applying straw in Artemia cultivation can lead to an increase in PUFA fatty acids with 18 carbon chains.

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Chitosan (Cs) was extracted from shrimp shell and its derivative forms including N-alkyl (AlkCs) and nanoparticles (CsNPs) were prepared. First, the properties of nanoparticles were determined by dynamic light scattering (DLS) and the morphology of nanoparticles and N-alkylated by scanning electron microscopy (SEM). Then their antibacterial activity was evaluated by the test of minimum inhibitory (MIC) and lethal (MBC) concentration, diffusion on agar by disk, permeability of cell membrane by measurement of cytoplasmic beta-galactosidase release (ONPG). The type of apoptosis cell death was also examined by DAPI staining and changes in cell surface integrity by atomic force microscopy (AFM). The results showed that the nanoparticles are spherical with an average hydrodynamic diameter of 240 nm. N-alkyl had a rough surface structure compared to native chitosan. At the least of MIC (78 μg/ml) and MBC (100 μg/ml) points were observed for CsNPs (P < 0.05). Nanoparticles and N-alkyl of chitosan showed the highest diameter of growth inhibition zone at 1250 concentration compared to other disks (p <0.05). Outer membrane permeability of derivative forms of chitosan showed significant differences with native chitosan and cells of control. DAPI staining test showed higher cell death of chitosan-derived forms. DAPI staining test showed higher cell death of derivative of chitosan. The images obtained from AFM showed a change in the membrane integrity of the treated cells compared to spherical and clustered of control cells. Thus, the antibacterial properties of native chitosan improved by physical and chemical modification.
 

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The human amniotic membrane (HAM) is one of the rare allograft tissues that are in use in clinical trials. Biocompatibility, antibacterial effect, low immunogenicity, and scar prevention are properties that have made HAM attractive for tissue engineering (TE) applications, for example, as a cell carrier, injectable hydrogel, and cell culture substrate. In this research, the effect of digestion time on the structure, gelation kinetics, rheological and biological properties of amniotic membrane-derived hydrogels was studied. The results determined that digestion with pepsin should be performed at least for 24 h.  Prolonging the digestion time to 72 h increased the shear modulus, fiber diameter, and gelation rate. Cytocompatibility assays with L929 fibroblast cells showed that the digestion time had no effect on the cell toxicity of the hydrogels. However, cell proliferation was improved due to preserved constitutive bioactive molecules. The results of this research can be used to develop amniotic membrane-derived hydrogels for TE applications.

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The Juice clarification is an important operation in the fruit processing industry. Sour Orange is a source of vitamin C that is cultivated in the north of Iran. Since turbidity of this fruit after juice extraction affects on quality, shelf-life and concentration of juice; clarification and removing of turbidity-causing factors is important. In this study, the effect of membrane parameters including pressure (1.2-2.2 bar) and temperature (25-35 ºC) on the quality characteristics of sour orange during membrane clarification was investigated. The response surface methodology (RSM) by Design-Expert Software was used to optimize the clarification conditions. Results of the experiments showed that the Browning index was raised by increasing of temperature, but vitamin C content, Total antioxidant activity value and clarity was decreased in this condition. The Browning index was decreased by increasing of pressure; however, no significant effect was observed on the other quality characteristics. Results of process optimization indicated that the best condition to maximize of vitamin C content, total antioxidant and clarity and to minimize of Browning index achieved at 25 ºC and 1.7 bar. In this condition the vitamin C content, Browning index, Total antioxidant activity and clarity was 24.9 (mg/100 cc juice), 0.106, 87.97% and 97.1%, respectively.