Investigation of Structural, SEM, TEM and Dielectric Properties of BaTiO3 nanoparticles

BaTiO3 nanoparticles were prepared by solvothermal method. The X-ray diffraction (XRD) analysis was used to study the structure and crystallite size of BaTiO3 nanoparticles. The morphology and the size of the BaTiO3 nanoparticles were characterized using scanning and transmission electron microscopy (SEM and TEM). The optical properties were studied using the UV-Visible spectrum in the wavelength range of 300-800 nm. The dielectric properties of BaTiO3 nanoparticles were studied for different frequencies and different temperatures. The AC electrical conductivity study revealed that the conduction depended both on the frequency and the temperature

Improved Performance of CaCl2 Incorporated Polyethersulfone Ultrafiltration Membranes

Poly(ethersulfone) (PES) / poly(vinylpyrrolidone) (PVP) blend membranes modified with calcium chloride (CaCl2) were prepared by phase inversion method. Effect of CaCl2 on the morphology, filtration and performance characteristics of the PES/PVP membranes was studied in detail. Results indicated that CaCl2 blend membranes possessed better porosity and flux than the pristine PES membrane. Dye separation efficiency of CaCl2 blend membranes was also increased considerably. Especially, the PES/PVP blend membrane with 1 wt% CaCl2 showed highest permeate flux and improved dye rejection. Fouling analysis carried out on CaCl2 blend membranes clearly showed that these membranes possessed better antifouling effect than pure PES membrane. Thus the CaCl2 blended PES/PVP membranes are more promising for the treatment of dye polluted wastewater

Studies on Hall Effect and DC Conductivity Measurements of Semiconductor Thin films Prepared by Chemical Bath Deposition (CBD) method

Semiconductors have various useful properties that can be exploited for the realization of a large number of high performance devices in fields such as electronics and optoelectronics. Many novel semiconductors, especially in the form of thin films, are continually being developed. Thin films have drawn the attention of many researchers because of their numerous applications. As the film becomes thinner, the properties acquire greater importance in the miniaturization of elements such as resistors, transistors, capacitors, and solar cells. In the present work, copper selenide (CuSe), cadmium selenide (CdSe), zinc selenide (ZnSe), lead sulphide (PbS), zinc sulphide (ZnS), and cadmium sulphide (CdS) thin films were prepared by chemical bath deposition (CBD) method. The prepared thin films were analyzed by using Hall measurements in Van Der Pauw configuration (ECOPIA HMS-3000) at room temperature. The Hall parameters such as Hall mobility of the material, resistivity, carrier concentration, Hall coefficient and conductivity were determined. The DC electrical conductivity measurements were also carried out for the thin films using the conventional two – probe technique. The activation energies were also calculated from DC conductivity studies

Development and Validation of Stability Indicating RP-UPLC Method for Determination of Related Substances of Cinacalcet Tablets

INTRODUCTION: Analytical Chemistry is the oldest branch of Chemistry and is the foundation block on which other branches, namely, inorganic, organic, physical and biochemistry have grown to their present level. Understanding of these branches would not have been possible without an understanding and application of principles of analytical chemistry. It has provided us a glimpse of matter from simple atomic structures to complex molecules to comprehend properties based on structural arrangements. We have gained insight into the origin and evolution of the universe and life on our own planet through application of analytical techniques. An understanding of composition has contributed to improvement of material characteristics of natural resources and industrial materials to the benefit of mankind. Today we cannot think of even a single product of commercial use which has not been tested using analytical chemistry techniques before clearance for consumption Earliest studies were mainly concerned with understanding the composition of environment and natural resources based on classical methods of analysis. Classical Analysis also known as wet chemistry introduced quantitative studies and to this day forms the backbone of most university and industrial laboratories. Earliest techniques were by and large gravimetric in nature with the objective of determination of elemental composition. Titration methods evolved subsequently for acid-base and metals analysis of solutions. Analytical Chemistry is poised to make even greater contributions to betterment of life and understanding of new materials. AIM AND OBJECTIVE: The aim of the study is to develop simple, novel methods for the Determination of related substances of Cinacalet in bulk and pharmaceutical dosage forms. The estimation of Cinacalcet impurities in degraded product have been reported and review of literature indicated that no validated analytical method have been reported for pharmaceutical formulation till date. The objective of the present work is to develop analytical methods for the estimation of related substances in Cinacalcet tablets which comprises of the following. Reverse Phase -Ultra Performance Liquid Chromatographic Method (RP-UPLC) SUMMARY AND CONCLUSION: The present work entitled “Development and validation of stability indicating RP-UPLC method for determination of Related substances of Cinacalcet tablets” comprises of the following novel methods which have not been reported till date. Reverse phase-Ultra Performance Liquid Chromatography (RP-UPLC) The ultra violet method involves the determination of Related substances of Cinacalcet tablets 90mg by External standard method. The drug obeyed Beer’s Law at the concentration of 5-30 μg/mL. The correlation co-efficient was found to be 0.99 for the methods. The low percentage RSD value shows that the methods developed are not affected by the presence of sample matrix or devoid of interference by the excipients. In RP-UPLC method, C18column was used for estimation of impurities of Cinacalcet tablets. By trial and error method mobile phase chosen was Mobile phase A-0.1%v/v orthophosphoric acid and Mobile phase-B-Acetonitrile: Methanol (40.:60%v/v) and the effluents were monitored at 210nm for cinacalcet and its related compounds. The retention time was about 9.3. The chromatograms were then subjected to system suitability studies. The tailing factor and asymmetry factor were close to 1.2 which showed ascertained of the peak. The number of theoretical plate was found to be 355529 which proved the efficiency of the column. The correlation coefficient indicated linearity of the method. The %RSD values were < 10 which showed the reproducibility and specificity of the method and it can be used for routine analysis. The RP-UPLC method developed for determination of related substance of cinacalcet tablets 90mg is simple, accurate, precise rapid economical and stability indicating. The RP-UPLC methods though utilizes costly equipment is more accurate and highly specific and well suitable for more number of sample analysis and simultaneous estimation of drugs. The run time (27 min) enables for rapid determination of impurities . The method was validated for accuracy, precision, specificity, robustness, and detection and quantification limits, in accordance with ICH guidelines. Statistical analysis proved the method was precise, reproducible, selective, specific, and accurate for analysis of Cinacalcet and its impurities. The wide linearity range, sensitivity, accuracy, short retention time, and simple mobile phase showed that the method is suitable for routine quantification of impurities in Cinacalcet in pharmaceutical dosage forms with high precision and accuracy. Moreover, it may be applied for determination of Cinacalcet in the study of blend uniformity, tablet content uniformity and in-vitro dissolution profiling of Cinacalcet dosage forms, where sample load is higher and high throughput is essential for faster delivery of results Therefore all the proposed validation methods could be used for routine analysis and are devoid of interference by sample excipients

Investigation of anticancer activity and mechanisms of Meso- 2,3-dimercaptosuccinic acid (DMSA) in glioblastoma cell lines

A thesis submitted in partial fulfilment of the requirements of the University of Wolverhampton for the degree of Master of Philosophy.Glioblastoma (GBM) is an aggressive and the most prevalent form of brain tumour. It is characterized by high intertumoral and intratumoral heterogeneity and a low survival rate. Since 2005, the current gold standard of care for treating newly diagnosed GBM has remained the same: maximal safe resection, concomitant chemoradiation (CRT) with temozolomide (TMZ), and adjuvant TMZ. Thus, there is an urgent need to develop more therapeutic interventions for GBM to improve the disease prognosis. Our research group at the University of Wolverhampton has been working on repurposing known FDA approved drugs for cancer treatment. Previous studies from our group have shown that Disulfiram (DS), an FDA approved anti alcoholism drug has excellent anticancer activity against a wide range of cancers with its metal binding capability through its unique dithiol structure. Hence our group is interested in identifying clinically used dithiol compounds which are structurally similar to DS and has metal binding ability to repurpose them as potential anticancer drugs. This study focussed on determining the anticancer activity of Dimercaptosuccinic acid (DMSA), an FDA approved, orally administrated heavy metal chelator, clinically used to treat heavy metal poisoning. DMSA in combination with copper (Cu) exhibits cytotoxicity activity in GBM cell lines. DMSA+Cu, in combination with the conventional GBM drugs such as TMZ, Lomustine (CCNU) and Carmustine (BCNU), showed synergistic cytotoxicity and sensitized the GBM cell lines to first line drugs tested in this study. This study further explored the possible mechanisms of action of DMSA+Cu such as generation of reactive oxygen species (ROS), induction of DNA damage and cell death, inhibition of hypoxia induced stemness and epithelial to mesenchymal transition characteristics, which are the core anticancer mechanisms of DS+Cu. Collectively, our results show that DMSA+Cu induces DNA damage and cytotoxicity in GBM cell lines, in addition to synergistic enhancement of anti-GBM drugs. However, the mechanism of action of DMSA+Cu is very different to that of DS+Cu, especially we observed that DMSA+Cu does not target hypoxia induced cancer stem cell population or generate ROS to induce cytotoxicity. Thus, further studies on the mechanisms of DMSA+Cu induced cytotoxicity will translate DMSA as a potentially novel repurposed therapeutic agent for GBM treatment, due to its easy availability and established safety data

Protection mechanisms in the resurrection plant Xerophyta viscosa (Baker): both sucrose and raffinose family oligosaccharides (RFOs) accumulate in leaves in response to water deficit

Changes in water-soluble carbohydrates were examined in the leaves of the resurrection plant Xerophyta viscosa under conditions of water deficit. Sucrose and raffinose family oligosaccharides (RFOs), particularly raffinose, increased under these conditions, with the highest concentrations evident at 5% relative water content [RWC; 23.5 mg g−1 dry weight (DW) and 17.7 mg g−1 DW, respectively]. Importantly, these effects were reversible, with concentrations returning to levels comparable with that of the full turgor state 7 d after water deficit conditions were alleviated, providing evidence that both sucrose and RFOs may play a protective role in desiccated leaf tissue of X. viscosa. Further, because the sucrose-to-raffinose mass ratio of 1.3:1 observed in the dehydrated state was very low, compared with published data for other resurrection plants (always >5), it is suggested that, in X. viscosa leaves, RFOs serve the dual purpose of stress protection and carbon storage. XvGolS, a gene encoding a galactinol synthase enzyme responsible for the first catalytic step in RFO biosynthesis, was cloned and functionally expressed. In leaf tissue exposed to water deficit, XvGolS transcript levels were shown to increase at 19% RWC. GolS activity in planta could not be correlated with RFO accumulation, but a negative correlation was observed between RFO accumulation and myo-inositol depletion, during water deficit stress. This correlation was reversed after rehydration, suggesting that during water deficit myo-inositol is channelled into RFO synthesis, but during the rehydration process it is channelled to metabolic pathways related to the repair of desiccation-induced damag

Evaluating molecular diagnostic techniques for seed detection of Pseudomonas savastanoi pv. phaseolicola, causal agent of halo blight disease in mungbean (Vigna radiata)

Halo blight of mungbean (Vigna radiata var. radiata) is caused by the bacterium Pseudomonas savastanoi pv. phaseolicola. This pathogen is transmitted via infected seed, facilitating the spread of the disease into new cultivated areas. Prospective mungbean seed crops are currently subjected to visual inspection as a means of determining disease status, however, this is a poor method that relies on visible symptoms and does not account for latent infections. A range of molecular diagnostics targeting P. savastanoi pv. phaseolicola have been developed, but these have not been deployed on seeds. Quantitative PCR (qPCR) SYBR assay, hydrolysis probe, and conventional PCR, using the same primers were optimised against a plate-truthed dilution series of P. savastanoi pv. phaseolicola. The detection limit of the conventional PCR assay was approximately 9,000 CFU µl-1, while both qPCR assays could detect 9 CFU µl-1. These tests were then used to screen DNA extracted from 200 g allotments of 38 seed lots comprising six mungbean cultivars representing the primary Australian production area, and two seed lots of known infection status. Of these, the pathogen was detected in six seed lots by conventional PCR. The SYBR assay and hydrolysis probe methods detected 20 and 24 infected seed lots respectively. This shows that the hydrolysis probe method was the most effective at diagnosing the presence of P. savastanoi pv. phaseolicola in mungbean seed, providing a valuable molecular diagnostic to aid in integrated disease management and seed certification, substantially mitigating losses to halo blight disease

Studies on Hall Effect and DC Conductivity Measurements of Semiconductor Thin films Prepared by Chemical Bath Deposition (CBD) method

Semiconductors have various useful properties that can be exploited for the realization of a large number of high performance devices in fields such as electronics and optoelectronics. Many novel semiconductors, especially in the form of thin films, are continually being developed. Thin films have drawn the attention of many researchers because of their numerous applications. As the film becomes thinner, the properties acquire greater importance in the miniaturization of elements such as resistors, transistors, capacitors, and solar cells. In the present work, copper selenide (CuSe), cadmium selenide (CdSe), zinc selenide (ZnSe), lead sulphide (PbS), zinc sulphide (ZnS), and cadmium sulphide (CdS) thin films were prepared by chemical bath deposition (CBD) method. The prepared thin films were analyzed by using Hall measurements in Van Der Pauw configuration (ECOPIA HMS-3000) at room temperature. The Hall parameters such as Hall mobility of the material, resistivity, carrier concentration, Hall coefficient and conductivity were determined. The DC electrical conductivity measurements were also carried out for the thin films using the conventional two – probe technique. The activation energies were also calculated from DC conductivity studies

ZrO2-based catalysts for biodiesel production: A review

ZrO2-based catalysts are remarkable catalyst with unique advantageous in transesterification and esterification for biodiesel production. Various modifications have been conducted refer to a specified surface properties consist of surface acidity/basicity, specific surface area and porosity, hydrophobicity, and catalysts stability. Summary on the basic concept on catalyst synthesis, applicability for various feedstocks along with their reus�ability aspect in biodiesel production are discussed in this review. Even though the activity of the catalyst is depending on many factors including the oil feedstocks, reaction temperature, molar ratio of oil to methanol, and other conditions, the controllable surface properties of catalyst is a benefit of ZrO2-based catalysts. The recy�clability and reusability of the catalyst become important aspect for developing a sustainable biodiesel pro�duction in the perspective of green chemistry. In addition, future perspective to make sure the applicability of the catalyst for a sustainable process by life cycle assessment is highlighted in this review

A molecular physiological review of vegetative desiccation tolerance in the resurrection plant Xerophyta viscosa (Baker)

Xerophyta viscosa (Baker) is a monocotyledonous resurrection plant from the family Vellociacea that occurs in summer-rainfall areas of South Africa, Lesotho and Swaziland. It inhabits rocky terrain in exposed grasslands and frequently experiences periods of water deficit. Being a resurrection plant it tolerates the loss of 95 % of total cellular water, regaining full metabolic competency within 3 days of rehydration. In this paper, we review some of the molecular and physiological adaptations that occur during various stages of dehydration of X. viscosa, these being functionally grouped into early and late responses, which might be relevant to the attainment of desiccation tolerance. During early drying (to 55 % RWC) photosynthesis is shut down, there is increased presence and activity of housekeeping antioxidants and a redirection of metabolism to the increased formation of sucrose and raffinose family oligosaccharides. Other metabolic shifts suggest water replacement in vacuoles proposed to facilitate mechanical stabilization. Some regulatory processes observed include increased presence of a linker histone H1 variant, a Type 2C protein phosphatase, a calmodulin- and an ERD15-like protein. During the late stages of drying (to 10 % RWC) there was increased expression of several proteins involved in signal transduction, and retroelements speculated to be instrumental in gene silencing. There was induction of antioxidants not typically found in desiccation-sensitive systems, classical stress-associated proteins (HSP and LEAs), proteins involved in structural stabilization and those associated with changes in various metabolite pools during drying. Metabolites accumulated in this stage are proposed, inter alia, to facilitate subcellular stabilization by vitrification process which can include glass- and ionic liquid formation