1,153 research outputs found

    Hopf-cyclic cohomology of the Connes-Moscovici Hopf algebras with infinite dimensional coefficients

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    We discuss a new strategy for the computation of the Hopf-cyclic cohomology of the Connes-Moscovici Hopf algebra Hn\mathcal{H}_n. More precisely, we introduce a multiplicative structure on the Hopf-cyclic complex of Hn\mathcal{H}_n, and we show that the van Est type characteristic homomorphism from the Hopf-cyclic complex of Hn\mathcal{H}_n to the Gelfand-Fuks cohomology of the Lie algebra WnW_n of formal vector fields on Rn\mathbb{R}^n respects this multiplicative structure. We then illustrate the machinery for n=1n=1.Comment: Minor revisions to highlight the main result

    Preliminary assessment of various additives on the specific reactivity of anti- rHBsAg monoclonal antibodies

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    Background: Antibodies have a wide application in diagnosis and treatment. In order to maintain optimal stability of various functional parts of antibodies such as antigen binding sites, several approaches have been suggested. Using additives such as polysaccharides and polyols is one of the main methods in protecting antibodies against aggregation or degradation in the formulation. The aim of this study was to evaluate the protective effect of various additives on the specific reactivity of monoclonal antibodies (mAbs) against recombinant HBsAg (rHBsAg) epitopes. Methods: To estimate the protective effect of different additives on the stability of antibody against conformational epitopes (S3 antibody) and linear epitopes (S7 and S11 antibodies) of rHBsAg, heat shock at 37°C was performed in liquid and solid phases. Environmental factors were considered to be constant. The specific reactivity of antibodies was evaluated using ELISA method. The data were analyzed using SPSS software by Mann-Whitney nonparametric test with the confidence interval of 95%. Results: Our results showed that 0.25 M sucrose, 0.04 M trehalose and 0.5% BSA had the most protective effect on maintaining the reactivity of mAbs (S3) against conformational epitopes of rHBsAg. Results obtained from S7 and S11 mAbs against linear characteristics showed minor differences. The most efficient protective additives were 0.04 M trehalose and 1 M sucrose. Conclusion: Nowadays, application of appropriate additives is important for increasing the stability of antibodies. It was concluded that sucrose, trehalose and BSA have considerable effects on the specific reactivity of anti rHBsAg mAbs during long storage. © 2015, Avicenna Journal of Medical Biotechnology. All rights reserved

    An extension of the spectral Tau method for numerical solution of multi-order fractional differential equations with convergence analysis

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    AbstractThe main purpose of this paper is to provide an efficient numerical approach for the fractional differential equations (FDEs) based on a spectral Tau method. An extension of the operational approach of the Tau method with the orthogonal polynomial bases is proposed to convert FDEs to its matrix–vector multiplication representation. The fractional derivatives are described in the Caputo sense. The spectral rate of convergence for the proposed method is established in the L2 norm. We tested our procedure on several examples and observed that the obtained numerical results confirm the theoretical prediction of the exponential rate of convergence

    Expression of an innate immune element (mouse hepcidin-1) in baculovirus expression system and the comparison of its function with synthetic human hepcidin-25

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    Hepcidin is an innate immune element which decreases the iron absorption from diet and iron releasing from macrophage cell. In contrast to the chemical iron chelators, there has been limited effort applied to the specific use of hepcidin as a new drug for decreasing the iron overload. Hepcidin is produced in different biological systems. For instance, E-coli is used for human hepcidin expression, however, post-translational modification is impaired. We have used a simple baculovirus expression system (BES) to improve the hepcidin folding and activity. Hepcidin Messenger Ribonucleic acid (mRNA) was isolated from mouse liver cells and its complementary Deoxyribonucleic acid (cDNA) was produced and amplified. PFastBac HTB vector was used for recombinant bacmid production. Recombinant baculovirus was produced using SF-9 cell line. The mouse hepcidin-1 protein was expressed in a large quantity and functional tests were performed for this recombinant peptide. The yield of hepcidin in BES was 20 μg/mL and anti-histidine (anti-His) tag antibody was used for the confirmation of hepcidin on western blot nitrocellulose paper. Functional tests showed that mouse hepcidin accumulates iron in the macrophage cell line J774A.1 up to 63%. In addition, our data showed that the mouse hepcidin-1 has less toxicity compared to the synthetic human hepcidin-25 (p = 0.000). © 2011 by School of Pharmacy

    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

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    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

    Molecular cloning and expression of novel fibroblast growth factor-2 conjugated with immunodominant domains of pseudomonas exotoxin

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    Angiogenesis is very important in cancer growth and metastasis. Basic fibroblast growth factor (bFGF) as one of the most important angiogenesis factors is an attractive target for cancer vaccine. Due to low immunogenicity, it cannot stimulate an effective immune response. Theoretically, pseudomonas exotoxin (PE) as a potent immunogenic carrier protein when fused to low immunogenic antigens such as bFGF significantly increased immunogenicity of it. In this study, we tried to molecular cloning and expression of bFGF conjugated with immunodominant domains of pseudomonas exotoxin. The coding sequence of fusion protein composed of bFGF linked to PE domains 1b and 2 using EAAAK poly linker. The KDEL sequence was also used in C-terminal coding sequence. It was synthesized and expressed using recombinant DNA technology in the bacterial expression system. Expression of recombinant protein verified using SDS-PAGE and western blot analyses. Finally, it purified using Ni-affinity chromatography. The band close to 37 kDa in SDS-PAGE and western blot analyses was aligned completely to designed sequence. Purified recombinant protein also showed as a clear single band near to 37 kDa

    Is the high cu tolerance of trichoderma atroviride isolated from the cu-polluted sediment due to adaptation?: an in vitro toxicological study

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    The tolerance of Cu by Trichoderma atroviride, a tolerant fungus isolated from the drainage surface sediment of the Serdang Industrial Area was investigated under in vitro conditions. Only this fungus species can tolerate up to 600 mg/L of Cu on solid medium Potato Dextrose Agar based on the isolation of the most tolerant fungus from the polluted sediment. Toxicity test performed on T. atroviride, showed a maximum tolerance at 300 mg/L of Cu concentration when grown in liquid medium Potato Dextrose Broth (PDB). The EC50 value of the isolate was 287.73 mg/L of Cu concentration in PDB. The Cu concentration in the drainage surface sediment, where the T. atroviride was isolated from, was 347.64 μg/g while the geochemical distributions of the non-resistant and resistant fractions of Cu were 99.6 and 0.4%, respectively. The sediment data indicated that the drainage had greatly received anthropogenic Cu from the nearby industries which are involved in the manufacturing of plastics and electronic products. The present findings indicate that the high Cu tolerance showed by T. atroviride could be due to the well adaptation of the fungus to the Cu polluted sediment. Therefore, T. atroviride could be a potential bioremediator of Cu pollution in the freshwater ecosystem

    Useful and harmful effects of using modern communication media (internet, satellite and mobile phone) from female students’ point of view in Bahar city

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    Background and Objectives:The proliferation of the Internet, video, audio, and mobile media has made many families t to have face-to-face problems with their children. The accepted norms of families are widely questioned and denied by children and cause problems that are dysfunctional and cause a kind of disorder and imbalance in the social system, in a way that challenges the core values ​​and public security of the social system. This hurts the collective conscience and public concern of the elite. New communication media allow children to communicate outside of social and geographical boundaries. Today, computers, networks, software, and everything related to them create new pressures and issues that people must adapt to and the new arena in which they express their normal or abnormal reactions. Gaining the necessary knowledge about new communication media and learning the skills to use them can direct its educational effects. Satellite, mobile phones and the Internet are emerging phenomena affecting education that have become part of the lives of people in societies, affecting thoughts and feelings, relationships and education in general; as the characters portrayed in the media may become role models for people and influence their attitudes, beliefs and behavior. Increasing information and being different in the news is one of the advantages of modern communication media that obtains information from sources with high speed and volume and presents it to the audience. The main purpose of this research was to determine the effects of using modern media communication from Bahar city students' point of view. Methods: The method of this research was descriptive, a kind of survey. Statistical population of the study included all female high-school students in Bahar city. Therefore, in terms of multi-cluster sampling method 288 individual were selected. The main instrument for gathering data in this research was a research-made questionnaire. For data analysis, the inferential statistics such as Kolmogorov-Smirnov test, one sample t-test and dependent t-test were used. Findings: The results showed that students believed that using modern media communication like Internet. Mobile, and so on, have harmful and useful effects. Nevertheless, the harmful effects of them are more than their useful effects. The useful effects were: increasing the social relationship of students, promoting the individual consciousness, and facilitating second language learning. On the other hand, the harmful effects were: students’ morality disorders, isolation of students, educational drop-out, decreasing the use of local slangs, and decreasing sport activity time among students. Conclusion: Considering the positive effect of using new communication media on social relations, personal awareness and facilitating second language learning, it is suggested that teachers and school officials design and use a plan for using these media in the classroom. It was also found that the harmful educational effects of modern communication media are: creating moral turmoil in students, isolating students, academic failure, reducing the use of local dialect and reducing the time of sports activities in them. Therefore, according to this finding, it is recommended that children be taught in school how to use these media correctly, as well as how to evaluate and select media content. In addition, it is suggested that the educational effects of each of the new communication media, such as mobile phones and related virtual networks, as well as satellite and the Internet, be investigated separately. It is also suggested that research be done on the correct pattern of mobile phone use and its educational opportunities and threats among students

    Reflective self-awareness exercise; steps towards changing students’ attitudes towards disability

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    The aim of this study was to explore the changes in students attitudes regarding disability after attending the module ‘Disability: theories, nature and experiences’ designed around reflective self-awareness exercises. Literature indicates enhanced knowledge does not automatically lead to changes in attitude. Health care professionals are the most significant people to instil hope in their clients to pursue a happy life. As advocates for people with disability, health care professionals need themselves to believe that people with disability can pursue a happy life as abled bodied people do. Researchers aimed to explore the impact of the ‘Disability’ module using discussion and reflective exercises, on students’ way of thinking about and changes in attitude towards disability. Students were asked to write stories at the beginning and after completing the module. A thematic analysis was applied to identify the students’ way of communicating their thoughts and feelings about disable bodied /disability before and after the module. Three major themes were identified to represent the differences before and after attending the module: problem /solution oriented approach towards perceived problems, separating/ integrating disable/able bodied, passive/ active role of disable bodied and society
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