Removal of heavy metals from waste water using locally derived chitosan

In this research work natural bio polymer “chitosan” was synthesized using locally available shrimp shells and adsorption of chromium by chitosan was studied. Synthesize of chitosan involved four main stages as preconditioning, demineralization, deprotenisation and deacetylation. “Preconditioning” process is a new step introduced in this research, to remove loosely bound protein. In the preconditioning, the skeletal matrix structure is first weakened which makes easier to remove soluble protein by washing with water. Therefore during deproteination process less alkali concentration can be used. Effect of deacetylation conditions such as alkali concentration, number of times of deacetylation performed and reaction temperature was investigated. Chitosan was characterized using Fourier Transform Infrared Spectroscopy (FTIR), Differential Thermal analysis (DTA), Thermal Gravimetric Analysis (TGA) and X-ray diffraction (XRD). These characterization techniques confirm the existence of chitosan. Degree of deacetylation was calculated using FTIR spectra. This value was highly depending on reaction temperature, reaction time, alkali concentration and number of times of deacetylation. Both characterization techniques confirm the existence of chitosan. The affinity of chitosan for chromium was studied using K2Cr2O7 solution as the heavy metal solution containing Cr (VI) ions. Adsorption of chromium ions by chitosan was investigated under different conditions. The effect of reaction temperature, particle size of chitosan and pH of solution were studied. Amount of chromium absorbed under different conditions was evaluated using atomic absorption spectroscopy

Developing Inhibitors Of Uchl5 Deubiquitinase In The Proteasome

Ubiquitin proteasomal system (UPS) plays a vital role in maintaining protein homeostasis by eliminating misfolded and damaged proteins in a eukaryotic cell. Target proteins to be degraded are modified by poly-ubiquitination, which leads to degradation by 26S proteasome. Before entering the 20S catalytic subunit, the 19S regulatory particle is responsible for binding, unfolding, and deubiquitinating the target protein. Based on the nature of the polyubiquitin tag, removal of the ubiquitin is performed by the deubiquitinases (DUBs) associated with the proteasome.Ubiquitin carboxyl-terminal hydrolase isozyme L5 (UCHL5) is one of the three DUBs in the proteasome. UCHL5 regulates many cellular functions and act as a key player in modulating cancer cell survival. Despite the therapeutic potential of UCHL5 in treating cancer, there are few inhibitors, and all of them suffer from poor selectivity. Therefore, we have performed a virtual screening with an FDA-approved drug library against the active site of UCHL5 and identified tiaprofenic (TA) acid as a potential inhibitor of UCHL5. We then designed and synthesized derivatives of TA guided by computational docking analyses. Our in-vitro evaluation revealed TAB2 as one candidate compound, which inhibits UCHL5 activity with improved potency. TAB derivatives have two carboxylic groups, which would impede its cell permeability. Therefore, cell-permeable acetoxymethyl derivatives of TAB compounds were synthesized, namely TAB-AM. We further demonstrated that TAB-AM derivatives retained their potency in inhibiting cancer cell viability and migration in MDA-MB-231 and MM.1S cells. Furthermore, we have extended our structure-based high throughput virtual screening approach to identify novel lead compounds as potential inhibitors targeting UCHL5 and successfully characterized the compounds. The inhibitory potential of these lead compounds could be further improved by the design and synthesis of their derivatives in the future

Removal of heavy metals from wastewater using chitosan

In this research work natural bio polymer “chitosan” was synthesized using locally available shrimp shells and adsorption of chromium by chitosan was studied. Synthesize of chitosan involved four main stages as preconditioning, demineralization, deprotenisation and deacetylation. Chitosan was characterized using Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD). Both characterization techniques confirm the existence of chitosan. The affinity of chitosan for chromium was studied using K2Cr2O7 solution as the heavy metal solution containing Cr (VI) ions. Adsorption of chromium ions by chitosan was investigated under different conditions. The effect of reaction temperature, particle size of chitosan and pH of solution were studied. Amount of chromium absorbed under different conditions was evaluated using atomic adsorption spectroscopy

First-principles calculation on electronic properties of Bismuth-halide inorganic perovskites for solar cell

Solar energy is a commonly used alternate source of energy and it can be utilized based on the principle of the photovoltaic effect. The photovoltaic effect converts sun energy into electrical energy using photovoltaic devices (solar cells)

Synthesizing and characterization of natural biopolymer chitosan derived from shrimp type, penaeus monodon

In this study natural biopolymer "chitosan" was synthesized using locally available shrimp type of Penaeus monodon. Synthesis of chitosan involved four main stages: preconditioning, demineralization, deprotenisalion and deacetylation. The first stage, "preconditioning " process, is a new step introduced in this research. Effect of deacetylation conditions such as alkali concentration, number of limes deacetylation was performed and reaction temperature was investigated. Yields of chitin and chitosan from R monodon were calculated. Chitosan was characterized using Fourier Transform Infrared (FTIR) Spectroscopy and X-ray diffraction. Degree of deacetylation of synthesized powder was calculated using FTIR spectra. Both characterization techniques confirm the existence of chitosan

Fabrication of dye sensitized solar cells using locally available sensitizers

Dye sensitized solar cells (DSSC) were fabricated using the dyes extracted from locally available natural plants of Mangosteen, Centella, Beetroot, Turmeric. Extracted dyes were analyzed using UV-vis spectrometer. Photo anodes were prepared by using regent grade TiO2 Powder. The TiO2 films were coated on Fluorine doped Tin Oxide (FTO) using doctor blade method and spray coating method. The film quality was examined using X-ray diffractometer and Scanning electron microscope (SEM). The film prepared using spray coating method has better uniformity. DSSCs fabricated using the dye extracted from mangosteen have shown high efficiency than the DSSCs of other dyes. Combined dye absorptions of X (mangosteen and centella) and Y (mangosteen and turmeric) were done to increase the efficiency. The DSSC fabricated with mangosteen and centella combination of dyes yielded the maximum performance

Effect of Reflux temperature on synthesis of hdroxyapatite by wet chemical precipitation technique

In this study, hydroxyapatite HA, [(Ca>o(P04)6(OHi:,j] was synthesized using wet chemical precipitation technique at different reflux temperatures. Calcium hydroxide [Ca(OH)J powder and Phosphoric acid [H3PO4] solution were used as starting materials. Variation in PH value of Ca(OHsuspension during the addition of H}P04 solution was analyzed. The effect of reflux temperature for the synthesis HA was investigated. Characteristics of synthesized powder were analyzed by Fourier transformed infrared (FTIR) spectroscopy and X-ray dijfraction (XRD). The powder characteristic has demonstrated that, the reflux temperature played an important role in the synthesis of pure and single phase HA powder

Quality of life and its associated factors among home-dwelling older people residing in the District of Colombo, Sri Lanka: a community-based cross-sectional study

Introduction This community-based cross-sectional study explored the factors affecting overall and domain-specific (physical health, psychological health, social relationships and environmental) quality of life (QOL) of home-dwelling older residents of the District of Colombo, Sri Lanka.Methods A representative sample (n=723) of older adults aged >65 years was obtained by the multistage cluster sampling technique. QOL was assessed using the validated Sinhala version of WHOQOL BREF Questionnaire. Data analysis was done using SPSS V.20.Results The mean±SD age was 72.23±6.3 years with the overall QOL score being (mean±SD) 56.73±12.57/100. The mean±SD QOL score of physical health, psychological health, social relationships and environmental domains were 55.81±15.80, 59.25±14.68, 46.36±20.08 and 64.61±11.96, respectively. The overall QOL in the adjusted model showed a significant positive association with the educational status, living conditions (with spouse, with spouse and children), participation in religious activities, being visited by friends or relatives and financial independence. The overall QOL was negatively associated with limitations in activities of daily living and instrumental activities of daily living, chronic arthritis and heart disease in the adjusted model. Living with the spouse was positively associated with the psychological domain of QOL. Osteoporosis and chronic arthritis affected the physical health domain, while cancer and disabling stroke affected the psychological domain of QOL negatively. All statistical significances were considered at p<0.05.Conclusion The overall QOL of home-dwelling elders of the Colombo District is moderate, with the lowest score being in social relationships and the highest in the environmental domain. Educational status, engaging in religious activities and financial independence are key factors associated with a better QOL. Limitations in physical activity and chronic diseases are associated with a reduced QOL. Living with the spouse is a key factor associated with the psychological health domain