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Research subject:
As a low price biomass, rice husk is able to accumulate a large amount of silica in its texture. The process for extracting this silica is greener than the conventional ones. The present research addresses the effects of the different process parameters on amorphous silica extraction from rice husk through a precipitation method.
Research approach
In the extraction process, first the rice husk was burned in the open air and then turned into white ash in an electric furnace. This ash was converted into sodium silicate solution using NaOH, and finally the silica was precipitated from this solution by sulfuric acid. The effect of solid to solvent ratio, the duration of the alkaline dissolution step as well as the pH and temperature of acid precipitation step have been investigated. Moreover, a special application of the amorphous silica in rubber industry was also investigated.
Main results
The results showed that a low solid to solvent ratio at the alkaline dissolution stage as well as an acidic pH along with a high precipitation temperature are required to obtain the highest production efficiency and to obtain high purity amorphous silica. The purity and chemistry of obtained silica were quite similar to commercial sample in the rubber industry; however, the surface area and pore volume of obtained silica was less than the commercial one. It was also found that prolonging the alkali dissolution step slightly increases the production efficiency. The obtained silica exhibited very close performance to the commercial sample, in the rubber-to-fiber adhesion system (RFS). This indicates the high ability of precipitated silica to be replaced by commercial types, which are mainly produced by more cost-effective and less biocompatible processes.

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Abstract
Research subject: In this research, epoxy modification was successfully performed by polyurethane and its effect on abrasion and adhesion properties have been investigated. The most important concern in the blending of these polymers was the formation of gels upon exposure of epoxy resin and isocyanate in polyurethane.
Research approach: One solution to overcome this problem is to control the chemical activity of Isocyanate. Therefore to reduce the chemical activity of isocyanate and prevent gel formation due to the combination of epoxy and polyurethane, first polyurethane prepolymer containing 3.58 wt.% NCO was prepared by mixing poly tetra methylene glycol 2000 (PTMG 2000) and toluene di isocyanate (2,4-TDI); and then by adding 20 wt.% of it to the epoxy resin, the curing process was completed by using dimethyl thio-toluene di amine (DMTDA) as a common curing agent and also specific heat treatment.
Main results: Fourier transformation infrared spectroscopy results showed that the modification process has been successful by elimination of the peaks related to epoxide and isocyanate groups in the prepared sample in addition to the formation of a broad peak related to secondary hydroxyl group (C-O) due to the opening of epoxide rings. Pull off tests also confirmed increasing adhesion to carbon steel substrate as a result of secondary hydroxyl generation through this blending. Although, the Persoz hardness of modified epoxy decreased by 5%, but with a 17-fold reduction of elastic modulus (as per tensile test result), abrasion resistance improved 6 times according to abrasion test. Finally, joining of the cavities to each other is introduced as the abrasion mechanism by considering the field emission- scanning electron microscope images.

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Our study aims to evaluate the physicochemical mechanism involved in the adhesion of Fusarium oxysporum f. sp. albedinis (Foa) on date palm root of resistant (Aziza M) and susceptible (Boufegouss) varieties by determining their surface properties. Hydrophobicity of Date palm root and Foa was evaluated by contact angle measurement (θ_w) and free energy of interaction determination (∆Giwi). Our results showed that Foa surface is hydrophilic (θ_w = 30.57° and ΔG_iwi = 15.51 mj/m²) and has an important electron donor character (γ^- = 53,99mj/m²), whereas its electron acceptor property is low (γ⁺ = 8.95 mj/m²). Regarding date palm, the surface of sensitive variety’s root is hydrophilic (θ_w = 62.97°), while that of resistant variety is hydrophobic (θ_w = 69.50°). This character was confirmed by quantitative approach (ΔG_iwi = 6.84 mj/m² for sensitive variety and ΔG_{iwi =} -20.61 mj/m² for resistant variety). Also, it was noted that both resistant and sensitive varieties are weak electron acceptors (γ ⁺ = 0.15 mj/m² and γ ⁺ = 0.08 mj/m² for resistant and sensitive varieties respectively). The two varieties are relatively important electron donors, but the sensitive variety is more donor (γ^- = 30.5 mj/m²) than the resistant one (γ^- = 16.57 mj/m²). These results suggest that hydrophilic character and electron donor/acceptor character may be responsible for the adhesion of Foa on sensitive date palm root and therefore causes its susceptibility to bayoud disease. In contrast, the hydrophobic character of the resistant variety could explain its resistance.

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Atherosclerosis is a chronic vascular disease and remains the leading cause of death and morbidity worldwide. Endothelial dysfunction is an important factor in the progression of atherosclerotic disease. Increased expression of cell adhesion index genes and decreased cell-binding proteins lead to abnormal endothelial function. These molecular changes are one of the most important indicators of endothelial cell dysfunction and the progression of atherosclerosis. CXCR3 is a G-protein-coupled chemokine receptor expressed by endothelial cells. The role of the receptor CXCR3 and its ligands in endothelial cells and heart disease is not yet fully understood. In this study, we evaluated the effect of CXCR3 downregulation on the expression level of adhesion (I-CAM-1, V-CAM-1), tight junction (TJP1), related to endothelial dysfunction.
In order to reduce the expression of the CXCR3 gene, the RNA-cleaving DNAzyme was used against the mRNA of the CXCR3 gene. DNAzyme was transfused into HUVEC cells by TurboFect^TM. After confirmation of decreased CXCR3 gene expression, RNA extraction and cDNA synthesis were performed and then the expression of markers was evaluated by RT-qPCR technique.
Our result was showed the expression level of I-CAM-1 and V-CAM-1 were showed significant up-regulation in transfected cells compared with control cells, while the TJP1 gene was not showed significant change. It seems that reducing the CXCR3 gene expression could induce endothelial dysfunction through the change of adhesion markers genes expression. Therefore, this receptor can be considered as a potential molecular target for a better understanding of the mechanism of atherosclerosis.

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Objective: The aim of the this study was to investigate the prevalence of toxB, paa, lpf and iha adhesion genes in enteropathogenic Escherichia coli (EPEC) isolates lacking in two important adhesion factors, the eaeA and bfpA genes. Methods: We examined a total of 70 serologically confirmed EPEC (eaeA^-, bfpA^-) isolates. DNA from the isolates was extracted by the phenol-chloroform method. toxB, paa, lpf and iha adhesion genes in the EPEC isolates were detected by polymerase chain reaction. Data were analyzed by SPSS software and statistical analysis using the chi square test. P-values less than 0.05 were considered significant. Results: PCR was positive for the toxB gene in 2 (2.85%), paa in 3 (4.28%), lpf in 32 (45.71%) and iha in 15 (21.42%) of the 70 strains. Statistically, none of the toxB, paa, and lpf genes were associated with diarrhea. However, the iha gene showed a weak significant relation to diarrhea (P=0.11). Conclusion: The main mechanism of pathogenicity for EPEC is attachment and effacement. Therefore, EPEC (eaeA^-, bfpA^-) should have another adhesin factor, which should be investigated. EPEC strains (eaeA-, bfpA-) that possess the lpf gene are common. Further investigations of the virulence properties of these strains are necessary in order to elucidate the role of these virulence factors in diarrhea among Iranian children.

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Objective: Acinetobacter baumannii (A. baumannii) has a good potential to colonize on various surfaces. As a virulence factor, adhesion to surfaces is the first step in colonization. The Two-Partner Secretion System (TPS) proteins are key factors for bacterial attachment. The purpose of this study is to identify and study the role of this family of proteins in adhesion of A. baumannii to human epithelial cells. Methods: Gene homologues that encoded the TPS were analyzed by bioinformatics tools and the primers were designed accordingly. The constructs synthesized in the pET22b vector were transferred to BL21(DE3). The transformed cells were named FhaB1 and FhaB2. The protein expression on the cell membrane was studied in addition to bacterial adhesion and biofilm formation by recombinant strains, A. baumannii and E.coli BL21(DE3). Results: Bioinformatic studies showed the bacterial potential of producing two exoproteins (FhaB1 and FhaB2). Expression of the recombinant proteins on the outer membrane was confirmed by Western Blot Analysis and whole cell ELISA. The results revealed an association between the recombinant cells and bacterial adhesion and biofilm formation. FhaB1, FhaB2  and A. baumannii exhibited enhanced adherence to human lung epithelial cells compared to E.coli BL21(DE3) Conclusion: TPS in A.baumannii is of adherence and colonization factors and is one of the bacterial virulence factors.

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Detecting and Preventing wheels slipping is at the core of all researches related to railway vehicle dynamics. In this paper, three fast non-elliptic contact models are evaluated and compared to each other in terms of contact patch, pressure and traction distributions as well as the creep forces. Among them Johnson and Kalker method was really useful to the similar problems while the common assumption is elastic half-space that many errors could be made especially in gauge-corner contact. Based on the conclusions drawn from this evaluation, two new methods is proposed which results in more accurate contact patch and pressure distribution estimation while maintaining the same computational efficiency. The Beam and Bristle model are proposed for tire engineering in automotive industries but they can predict slip in wheel-rail contact too. New methods are typically used for tire engineering. Tire engineering usually is dealing with higher values of slippage than there is rail engineering. So that they can be applied into the saturation zone. At last a FEM analysis will be done for evaluating the methods proposed. Also in the special case there is similar experimental projects done by other scientists. It should be noted that good agreement between FEM analysis results, tire engineering models, experimental results has been found for several contact applications including S1002 wheel profile over UIC60 rail profile for four different initial braking speed 30, 60, 100, 140 km/h have been compared with experimental results.

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Stem cells due to their ability of self-renewing and the potential of differentiating to different cell lineages are the ideal choices in regenerative tissue engineering. Under cyclic loading, these cells could differentiate to those kind of cells that experience similar conditions inside the body, like osteocytes and chondrocytes. In this research, the purpose is to investigate the effect of the 10 percent cyclic strain with the frequency of 1 Hertz on the mechanical response of a single mesenchymal stem cell cultured in a fibrin hydrogel block, using the finite element method and considering the role of integrins and implementing the Simo’s hyper-viscoelastic model for the cytoskeleton as long as the uniaxial loading leads the cell to differentiate toward Fibrochondrocyte. The results of presented model show that the averages of the circumferential, radial and shear stresses are 240, 260 and 140 Pascal, respectively and corresponding forces are 24, 45 and 15 Pico-Newton. The results imply that stresses and forces generated inside the cytoskeleton are large enough to elicit a different response from the cell. This research results can be very effective for better designing of biological experiments.

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Evaluation of probiotic properties of microorganisms isolated from stressful substrates has received considerable attention. Among probiotic microorganisms, yeasts are distinguished from lactic acid bacteria due to their bigger size, better adhesion ability, and resistance to antibiotics without the possibility of transferring resistance genes. In the present study, probiotic and antifungal properties of the predominant yeast isolated from natural honey were investigated. Sequencing results of the PCR products led to the identification of Saccharomyces cerevisiae as the predominant yeast isolated from honey. Moreover, the isolate had no hemolytic activity and showed the highest sensitivity towards natamycin among the studied antimycotic agents. In addition, although the yeast isolate had no proper survival under simulated gastrointestinal conditions, it had relatively high auto-aggregation (93.86%) and cell-surface hydrophobicity (76.36%). The highest co-aggregation ability of the isolate was also observed with Gram-positive bacteria Bacillus cereus and Staphylococcus aureus, and the inhibition activity of the isolate against B. cereus was significantly (p<0.05) higher than those of the other studied food-borne bacteria. The yeast isolate also showed 32.18% antifungal effect on Aspergillus flavus. Accordingly, the predominant yeast isolated from honey has suitable capabilities for application as a protective culture in fermentation industries.
 

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During root canal treatment, whole or a part of the tooth crown may be lost. Post and core is a method of repairing a damaged crown, in which a pinjet dipped in acrylic resin is used to mold the tooth canal and make a cast post and core. The main goal of this research is to produce an inexpensive pinjet with required strength and proper adhesion to acrylic resin. Therefore, to determine a right material for pinjet, lap shear and tensile tests were performed on eight polymer materials to check the adhesion of pinjet to acrylic resin and its yield strength, respectively. To produce some pinjets, a plastic injection mold was built and Moldflow Insight software was used to determine the process parameters of the injection molding. The results showed that HIPS 7240 with the lowest price among the examined materials and sufficient adhesion to acrylic resin is a suitable material for the pinjet. Also, this material with a yield strength of 10.91 MPa had an appropriate strength to prevent plastic deformation during the post and core molding process. While the injection time, melt temperature, and mold temperature were considered to 1 s, 230 ˚C, and 25 ˚C, respectively in both simulation and experimental methods, the injection pressure was 19 and 18 MPa and the injection speed was obtained 0.3 and 0.27 cm/s respectively in the simulation and experiments. Producing a perfect pinjet shows the ability and accuracy of the simulation in proposing the process parameters of plastic injection molding.
 

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Introduction:
Due to their role in regulating inflammation, monocytes and macrophages are important immune system cells incorporated and evaluated in various in vitro and in vivo disease modeling experiments. Accordingly, investigating appropriate culture conditions to maintain the viability, phenotype, and functionality of these cells is considered in different studies. In this study, we tried to evaluate whether the type of culture plate affects the adhesion, survival, and morphology of PMA-treated monocytes.
Methods:
 The THP-1 cell line was cultured in adherent or non-adherent culture plates and cells were treated with PMA small molecule to be induced into macrophages. The morphology of treated cells and the viability of detached cells were assessed three days post-induction.
Results and conclusion:
Our results showed that the morphology and viability of PMA-treated THP-1 cells were the same in both types of plates. In summary, we showed that the type of cell culture plate did not significantly affect PMA-treated THP-1 cells·