46 research outputs found
Surface assembly of nano-metalorganic framework on amine functionalized indium tin oxide substrate for impedimetric sensing of parathion
No full textThe present paper reports the assembly and pesticide sensing application of a nanometal organic framework [Cd(atc)(H2O)2]n (‘atc’=2-aminoterephthalic acid). The assembly of the NMOF film has been achieved by sequential dipping of a 2-aminobenzylamine (2-ABA) modified indium tin oxide (ITO) slide in organic linker ‘atc’ and metal ion ‘Cd2+’ solutions. The different structural and morphological characteristics of the NMOF thin film have been characterized. The availability of pendent –COOH functional groups on the assembled NMOF film is exploited to synthesize a pesticide immunosensor by conjugating the NMOF film with anti-parathion antibody. This immunosensor has been explored for the electrochemical impedance spectroscopy (EIS) based analysis of parathion in the concentration range of 0.1–20 ng/mL. The proposed detection is specific with respect to other organophosphate compounds, e.g. malathion, paraoxon, fenitrothion, monochrotophos and dichlorovos. The proposed sensor shows the detection limit of 0.1 ng/mL and it is applicable for analysis of parathion in a rice sample. The sensor's performance is validated by comparting the obtained results with gas chromatographic data.Authors gratefully acknowledge the financial grant from CSIR India through project OMEGA/PSC0202/2.2.5. We are thankful to the Director, CSIR-CSIO, Chandigarh, India. The fourth author acknowledges partial financial support from the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (MEST) (No. 2009-0093848)
Molar extinction coefficient of organic compounds as a function of effective atomic number
No full textA study on photoelectrochemical properties of ZnO@ZnS nanostructures synthesized via facile ion-exchange approach
No full textImpact of a conserved tyrosine residue on binding of family 1 carbohydrate binding modules to cellulose allomorphs
No full textThe recalcitrance of cellulose, coupled with non-productive binding of cellulases, is considered to be a major bottleneck in the deconstruction of biomass into biofuels (Jeoh, T., Cardona, M. J., Karuna, N., Mudinoor, A. R. & Nill, J. Mechanistic kinetic models of enzymatic cellulose hydrolysis—A review. Biotechnol. Bioeng. 114, 1369–1385 (2017). doi:10.1002/bit.26277). Past research to address the recalcitrance of cellulose, has led the development of pre-treatment technologies like the Extractive Ammonia process (Sousa, L. et al. Next-generation ammonia pretreatment enhances cellulosic biofuel production. Energy Environ. Sci. 9, 1215–1223 (2016). doi:10.1039/c5ee03051j), which can modify the ultrastructure of native crystalline cellulose-I to cellulose-III allomorph (Chundawat, S. P. S. et al. Restructuring the crystalline cellulose hydrogen bond network enhances its depolymerization rate. J. Am. Chem. Soc. 133, 11163–11174 (2011). doi:10.1021/ja2011115). Surprisingly, it was found previsouly that some full-length cellulases bind with lower apparent affinity to crystalline cellulose-III, while the enzymatic hydrolysis rate for this modified cellulose-III allomorph was between two to five-folds higher by fungal cellulase enzyme cocktails (Gao, D. et al. Increased enzyme binding to substrate is not necessary for more efficient cellulose hydrolysis. Proc. Natl. Acad. Sci. 110, 10922–10927 (2013). doi:10.1073/pnas.1213426110). Our results attest to better understanding the role of carbohydrate-binding modules (CBMs) on the reduced binding affinity of full-length fungal cellulases seen towards cellulose-III. Here, we closely explore the role of key amino acid residues of a Family 1 CBM that are likely to impact protein binding interactions with the surface of cellulose-III. Single-site saturation mutagenesis libraries were generated at such key positions to better understand impact on CBM-1 adsorption to both cellulose allomorphs. We report results here relating to the: (i) Expression and purification of green fluorescent protein (GFP) tagged wild-type CBM-1 protein construct and its single-site saturation mutagenesis protein library for subsequent binding/structural characterization, (ii) Effect of pH and salt concentration on the apparent binding affinity or partition coefficient of wild-type CBM-1 protein and its saturation mutagenesis mutants library towards cellulose allomorphs. We also report regression correlations between the experimentally measured binding parameters and various in silico sequence/structural modeling derived Rosetta software estimated parameters that are indicative of protein function. We also discuss a roadmap for future studies that include analysis of full scale binding isotherm of wild type and some of the key mutants to native and pre-treated cellulose, cloning and testing of overall cellulase activity with mutant CBM1-cellulases to understand the correlation between CBM-mediated overall binding affinity and cellulolytic activity on different cellulose allomorphs. This work has important implications for creation of more efficient cellulase enzymes, which can pave the way towards sustainable production of biofuels from ammonia-pretreated lignocellulosic biomass.M.S.Includes bibliographical referencesby Akash Dagi
Investigations on photoelectrochemical performance of boron doped ZnO nanorods synthesized by facile hydrothermal technique
No full textFeasibility study on measurement of magnetocardiography (MCG) using fluxgate magnetometer
No full textA study of Co-doping effect on thermoluminescence properties of potassium calcium sulphate
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Study and improvement of dynamics of an Electron Beam Lithography Machine
No full textAn ever-increasing demand for making microchips smaller and quicker pushes for the advancement of lithography machines. System dynamics plays an important role in determining the performance of a lithography machine. This thesis is aimed to increase the throughput of an electron beam lithography machine, mainly for sparse patterns, by improving the system dynamics. A detailed study was conducted to better understand the dynamics and possible limitations of the electron beam lithography machine. It was found that the stage motion generates a reaction force on the system, and this reaction force induces oscillations in the system resulting in the electron beam error. Furthermore, for sparse patterns, stage motion and electron beam settling consume most of the operation time. A solution method is proposed where an X-stage counter mass and a fourth-order trajectory generator is incorporated in the current system. This results in the elimination of system oscillations, reducing the settling time of the beam to zero and a reduction in stage motion time by 20%.Mechanical Engineering | Mechatronic System Design (MSD
Comparative Analysis of Calcium Carbonate Content in the Eggshells of Domestic Hen and Selected Wild Bird Species from the Marathwada Region of Maharashtra, India
No full textEggshells in birds are primarily composed of calcium carbonate (CaCO3), which provide mechanical strength and protection to the developing embryo. In this study, CaCO3 content in the eggshells of the domestic hen (Gallus gallus domesticus) as a control species, compared with three wild bird species — Baya weaver (Ploceus philippinus), Spotted munia (Lonchura punctulata), and Red-wattled lapwing (Vanellus indicus) — collected from different districts of the Marathwada region of Maharashtra, India. Eggshells were collected from poultry farms and natural nesting sites, then cleaned, dried, powdered, and analysed using a simple acid-base back titration method involving hydrochloric acid (HCl) and sodium hydroxide (NaOH). Among the species, the Red-wattled lapwing exhibited the highest average CaCO3 content (95.18% ± 1.95), followed by the domestic hen (94.93% ± 0.92), Baya weaver (93.20% ± 2.53), and Spotted munia (91.50% ± 2.43). Two-way analysis of variance (ANOVA) revealed statistically significant differences among species (F = 28.74, P < 0.001), districts (F = 4.79, P = 0.0118), and their interaction (F = 14.64, P < 0.001). These findings provide important baseline data for avian ecological studies and suggest that nesting strategies and habitat variability play key roles in eggshell mineral content. The use of backyard-raised hens as a domesticated control enhances the ecological relevance of the comparisons and highlights the utility of simple analytical methods in avian physiology and conservation research
