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Preparation and characterization of poly (ethylene glycol) grafted Caalginate fibers by γ-irradiation for biomedical applications

click Author
Md. Kamal Khan,
Applied Chemistry and Chemical Engineering
University of Dhaka
Mohammed Mizanur Rahman,
Applied Chemistry and Chemical Engineering
University of Dhaka
Bodrun Nesa,
Applied Chemistry and Chemical Engineering
University of Dhaka
https://www.apprhs.org/heartbeat/ed/bringing-viagra-on-a-plane.html Radiation processing, being a physical process, is an environmentally friendly alternative to chemical modifications. It is economically viable, safe, and possesses several advantages over other conventional methods employed for modification and grafting. To improve the physico-mechanical properties of Ca-alginate fiber (CaAF), poly (ethylene glycol) (PEG) was grafted by applying γ-radiation of different intensities. The effect of γ-irradiation on the physico-mechanical, thermal, morphological, thermal and water aging, water, and simulated body fluid (SBF) uptake were evaluated. FT-IR results confirmed that PEG was successfully grafted onto Ca-alginate fibers by γ-irradiation. From the detailed experimental results, irradiation doses and PEG concentration were optimized for grafting processes. The results showed that 50% PEG and 2.5 kGy irradiation dose yielded the highest tensile strength. Differential scanning calorimetric (DSC) analysis showed that with increasing γ-intensity a decrease of dehydration temperature of the fibers had occurred. On the other hand, the glass transition temperature (Tg) increased with increasing irradiation dose. The tensile cracked surfaces of the grafted alginate fibers were analyzed by scanning electron microscope (SEM) in order to monitor their surface morphologies. The SEM images of the cracked surfaces demonstrated that spherical shape rods were present for irradiated fiber sample while no such rods were observed for non-irradiated fibers. The characteristic data obtained from SBF and water uptake, and water and thermal aging experiments indicated that CaAF grafted with 50% PEG by applying 2.5 kGy γ-irradiation can be potentially
employed for biomedical purposes, such as surgical suture.
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https://www.apprhs.org/heartbeat/ed/mtf-viagra.html

Radiation Physics and Chemistry

Mohammed Mizanur Rahman
Applied Chemistry and Chemical Engineering
University of Dhaka
Shahriar Kabir
Applied Chemistry and Chemical Engineering
University of Dhaka
Taslim Ur Rashid
Applied Chemistry and Chemical Engineering
University of Dhaka

ed dysfunction how to get viagra from your doctor Abstract:

In the present study we have synthesized chitosan from waste prawns hell via g-irradiation of chitin and subsequent alkaline treatment. The detailed experimental studies demonstrated that nonirradiated chitin deacetylated by 40% NaOH solution showed 72% degree of deacetylation(DD), however 50k Gy irradiated chitin, deacetylated by 20% NaOH demonstrated 81.5% DD. Chitosanin solid state as obtained from g-irradiation of chitin was further irradiated by different doses(2–100kGy) of gamma irradiation and the effects of irradiation on the molecular weight, the rmo-mechanical by differential scanning calorimetry(DSC) and thermogravimetric analysis (TGA), and antimicrobial properties were evaluated with respect to nonirradiated chitosan sample. Gamma irradiation of chitosan with a dose of 100kGy caused a decrease in average molecular weight from1.9_105 to 6.5_104 Da  and thus increased its solubility in water. Nonirradiated and g-irradiated chitosan at concentration 1% (w/w) in water were prepared and used to evaluate of its potentiality for growth stimulation of Malabar spinach. The chitosan solution was sprayed on the specimen plants and neighboring soil where germinations were taken place and various plant growth parameters such as plan th eight, number of leaves, leaf areas, dry and wet weight of the plants and roots were investigated. The details study revealed that application of 30 k Gyirradiated chitosan yielded 60% higher growth of the Malabar spinach than that obtained from Nonirradiated chitosan. The data are consistent with preliminary results from field experiments and unambiguously confirms that a minor amount of chitosan has a pro found effect on the growth and development of Malabar spinach. 

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Evaluation of Fat Binding Capacity of Gamma Irradiated Chitosan Extracted from Prawn Shell

TASLIM UR RASHID,
Applied Chemistry and Chemical Engineering,
University of Dhaka,
SAYED M. SHAMSUDDIN,
Atomic Energy Research Establishment (AERE)
Institute of Radiation and Polymer Technology (IRPT)
MUBARAK A. KHAN,
We previously studied the effects of 2–100 kGy gamma radiation (generated from 6◦Co) on physicochemical, thermal, morphological, and antimicrobial properties of chitosan. The results demonstrated that these properties of chitosan were largely influenced by the action of gamma radiation. In addition, the fat binding capacity (FBC) of chitosan was found to be increased with increasing irradiation doses. In this work a thorough in vivo investigation on mice was performed to examine FBC of irradiated chitosan (30–100 kGy) in animal bodies. Different groups of mice specimens were fed with γ-irradiated chitosan along with natural rodent chow and cheese as well as sufficient supply of water. The unconsumed lipid measured in feces was found to increase by 67% in mice whose diet included 100 kGy irradiated chitosan, relative to that nonirradiated chitosan. After twelve weeks of intimate observation, mice were sacrificed to examine triglyceride (TG) and total cholesterol (TC) content in mice blood. The results demonstrated that TG and TC values of mice fed with γ-irradiated chitosan were significantly lower than that of the control. All of these findings are expected to enhance the future research on irradiated chitosan to be used as potential fat reducer in human metabolism.
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A new approach for the preparation of chitosan from γ -irradiation of prawn shell: effects of radiation on the characteristics of chitosan

Taslim Ur Rashid,
Mohammed Mizanur Rahman,
Shahriar Kabir,
go Abstract:
Chitosan is a biodegradable polymer composed of randomly distributed β-(1,4)-linked D-glucosamine (deacetylated unit) and N-acetyl-D-glucosamine (acetylated unit). It is produced commercially by deacetylation of chitin, which is the structural element in the exoskeleton of crustaceans (such as crabs and shrimps) and the cell walls of fungi. In the work reported, we
developed a facile technique for the preparation of chitosan by irradiating prawn shell at various intensities from 2 to 50 kGy. It was observed that γ -irradiation of prawn shell increased the degree of deacetylation (DD) of chitin at a relatively low alkali concentration during the deacetylation process. Among the various irradiation doses applied to prawn shell, a dose of 50 kGy and 4 h heating in 50% NaOH solution yielded 84.56% DDwhile the chitosan obtained from non-irradiated prawn shell with the same reaction conditions had only 74.70% DD. In order to evaluate the effect of γ -irradiation on the various physicochemical, thermomechanical and morphological properties, the chitosan samples were again irradiated (2–100 kGy) with γ -radiation. Molecular weight, DD, thermal properties with differential scanning calorimetry and thermogravimetric analysis, particle morphology by scanning electron microscopy, water binding capacity (WBC), fat binding capacity (FBC) and antimicrobial activity were determined and the effects of various γ -radiation doses were assessed. The DD, WBC, FBC and antimicrobial activity of the chitosan were found to improve on irradiation. It was obvious that irradiation caused a decrease of molecular weight from 187 128 to 64 972 gmol−1 after applying a radiation dose of 100 kGy which occurred due to the chain scission of chitosan molecules at glycosidic linkages. The decrease of molecular weight increased the water solubility of the chitosan, the extent of which was explored for biomedical applications.
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