Design and evaluation of synthetic silica-based monolithic materials in shrinkable tube for efficient protein extraction

Sample pretreatment is a required step in proteomics in order to remove interferences and preconcentrate the samples. Much research in recent years has focused on porous monolithic materials since they are highly permeable to liquid flow and show high mass transport compared with more common packed beds. These features are due to the micro-structure within the monolithic silica column which contains both macropores that reduce the back pressure, and mesopores that give good interaction with analytes. The aim of this work was to fabricate a continuous porous silica monolithic rod inside a heat shrinkable tube and to compare this with the same material whose surface has been modified with a C(18) phase, in order to use them for preconcentration/extraction of proteins. The performance of the silica-based monolithic rod was evaluated using eight proteins; insulin, cytochrome C, lysozyme, myoglobin, β-lactoglobulin, ovalbumin, hemoglobin, and bovine serum albumin at a concentration of 60 μM. The results show that recovery of the proteins was achieved by both columns with variable yields; however, the C(18) modified silica monolith gave higher recoveries (92.7 to 109.7%) than the non-modified silica monolith (25.5 to 97.9%). Both silica monoliths can be used with very low back pressure indicating a promising approach for future fabrication of the silica monolith inside a microfluidic device for the extraction of proteins from biological media

The role of charge localisation in mass spectrometry.

Ab-Initio molecular orbital calculations have been used to investigate the degree of charge localisation associated with the formation of ground state molecular radical cations upon electron impact for some simple amides, thio-amides, urea, thiourea, and their N-methyl substituted analogues, and guanidine. Some of the thio-amides which were not commercially available, were synthesised for the mass spectrometric studies. Ionisation energies have been calculated from the molecular orbital energies, using Koopmans' Theorem, and related to the predicted site of charge location in the molecular radical cations. The molecular orbital data was also used to study the effect of N-methylation on ionisation energy. The results obtained were found to be in close agreement with results obtained from photoelectron spectroscopy and electron impact mass spectrometry. Mulliken population analysis was used to obtain total atomic charges from the molecular orbital calculations so that the charge distributions in the neutral molecules and the radical cations could be compared. The molecular orbital calculations predict the major change in charge distribution to be equally shared between each nitrogen atom of urea, upon ionisation, with very little charge located on the oxygen; however for thiourea the change in charge distribution is largely located on the sulphur atom with very little change in the charge on either of the nitrogen atoms. These results are in agreement with previous predictions based on observed experimental data. The amides show more delocalisation with the charge more evenly distributed between nitrogen and oxygen, although N-methylation causes the charge to be preferentially located on nitrogen. The thio amides show the charge preferentially located on sulphur throughout. Molecular orbital calculations have also been used to investigate the energetics of the major fragmentation reaction in some of these compounds in relation to the predicted site of charge location in both the ground state molecular radical cations, and the fragment ions. This study has enabled an attempt to be made at rationalising the observed electron impact mass spectra on the basis of the calculated change in charge distribution upon ionisation of the compounds studied

Optimization preparation of the biosynthesis of silver nanoparticles using watermelon and study of its antibacterial activity

The field of nanotechnology is the most active area of research in modern materials science. There is increased demand on nanoparticles because of their wide applicability in various areas; for example, electronics, catalysis, chemistry, energy and medicine. Commonly, silver nanoparticles are fabricated using toxic and flammable chemicals. Therefore, the aim of this work is to find a cost effective and environment-friendly technique for green synthesis of silver nanoparticles from silver nitrate (AgNO3) solution using watermelon extract. The different parameters were optimised for the fabrication of silver nanoparticles including the contact time, concentration of watermelon extract, concentration of silver nitrate solution, reactant ratio, and reaction temperature. The fabricated nanoparticles were characterised using different instruments such as UV-Vis spectrophotometry and their size determined by transmission electron microscopy (TEM), while the element composition of the sample was obtained from the energy dispersive X-ray (EDX) spectrum. The antibacterial effect of the fabricated silver nanoparticles against two human pathogens Escherichia coli (E. coli) and Staphylococcus aureus (S.aureus) was studied and the obtained results confirm the fact that SNPs have the antibacterial property of nanoparticles

An innovative method of extraction of coffee oil using an advanced microwave system: in comparison with conventional Soxhlet extraction method

The production of energy and chemicals from waste biomass is an attractive alternative by comparison with first generation biofuels and fossil feedstocks. This paper investigates oil extraction from spent coffee grounds (SCG) by means of an advanced microwave process and compares this with a conventional Soxhlet extraction (SE) method. Microwave assisted oil extraction (MAE) from SCG was performed over different durations, varying solvent volumes and extraction temperatures. It was found that each of these parameters had an effect on the process, with the largest yield being over 11.54 wt %, oil extracted in 10 minutes using 160 ml of hexane at 95 oC. In 10 minutes, MAE was successful in extracting more oil than SE. MAE achieved a 24 fold decrease in duration for the extraction compared with SE and used less solvent per gram of oil produced. It is proposed that a certain moisture content in the SCG would be beneficial to the extraction process and might it also play a role in the heating process. The extracted oil can be converted into biodiesel and biochemicals leaving the remaining solids suitable for processing into bioethanol, fertiliser, adsorptive material and fuel pellets

Optimization of pH as a strategy to improve enzymatic saccharification of wheat straw for enhancing bioethanol production

In this work, wheat straw (WS) was used as a lignocellulosic substrate to investigate the influence of pH on enzymatic saccharification. The optimum enzymatic hydrolysis occurred at pH range 5.8 – 6.0, instead of 4.8 - 5.0 as has been widely reported in research. Two enzymes cocktails, Celluclast® 1.5L with Novozymes 188, Cellic® CTec2 and endo-1, 4-β-Xylanase, were used for the pH investigation over a pH range of 3.0 – 7.0. The highest concentration of total reduced sugar was found at pH 6.0 for all the different enzymes used in this study. The total reduced sugar produced from the enzymatic saccharification at pH 6.0 was found to be 7.0, 7.4 and 10.8 (g L-1) for Celluclast® 1.5L with Novozymes 188, endo-1, 4-β-Xylanase and Cellic® CTec2, respectively. By increasing the pH from 4.8 to 6.0, the total reduced sugar yield increased by 25% for Celluclast® 1.5L with Novozymes 188 and endo-1, 4-β-Xylanase and 21% for Cellic® CTec2. The results from this study indicate that WS hydrolysis can be improved significantly by elevating the pH at which the reaction occurs to the range of 5.8 to 6.0

Electrochemical Quantification of D-Glucose during the Production of Bioethanol from Thermo-Mechanically Pre-treated Wheat Straw

Mechanical pre-treatment (disc refining) of wheat straw, at both atmospheric and elevated pressure, is shown to be an efficient process to access fermentable monosaccharides, with the potential to integrate within the infrastructure of existing first-generation bioethanol plants. The mild, enzymatic degradation of this sustainable lignocellulosic biomass affords ca. 0.10-0.13 g/g (dry weight) of D-glucose quantifiable voltammetrically in real time, over a two hundred-fold range in experimental laboratory scales (25 mL to 5.0 L), with pressure disc refining of the wheat straw enabling almost twice the amount of D-glucose to be generated during the hydrolysis stage than experiments using atmospheric refining (0.06 – 0.09 g/g dry weight). Fermentation of the resulting hydrolysate affords 0.08 – 0.10 g/g (dry weight) of ethanol over similar scales, with ethanol productivity at ca. 37 mg/(L h). These results demonstrate that minimal cellulose decomposition occurs during pressure refining of wheat straw, in contrast to hemicellulose, and suggest that the development of green, mechanochemical processes for the scalable and cost-effective manufacture of second-generation bioethanol requires improved cellulose decomposition

A Disposable Microfluidic Device with a Screen Printed Electrode for Mimicking Phase II Metabolism

Human metabolism is investigated using several in vitro methods. However, the current methodologies are often expensive, tedious and complicated. Over the last decade, the combination of electrochemistry (EC) with mass spectrometry (MS) has a simpler and a cheaper alternative to mimic the human metabolism. This paper describes the development of a disposable microfluidic device with a screen-printed electrode (SPE) for monitoring phase II GSH reactions. The proposed chip has the potential to be used as a primary screening tool, thus complementing the current in vitro methods

Transcriptome analysis of grain development in hexaploid wheat

Background: Hexaploid wheat is one of the most important cereal crops for human nutrition. Molecular understanding of the biology of the developing grain will assist the improvement of yield and quality traits for different environments. High quality transcriptomics is a powerful method to increase this understanding. Results: The transcriptome of developing caryopses from hexaploid wheat ( Triticum aestivum, cv. Hereward) was determined using Affymetrix wheat GeneChip (R) oligonucleotide arrays which have probes for 55,052 transcripts. Of these, 14,550 showed significant differential regulation in the period between 6 and 42 days after anthesis ( daa). Large changes in transcript abundance were observed which were categorised into distinct phases of differentiation ( 6 - 10 daa), grain fill ( 12 - 21 daa) and desiccation/maturation ( 28 - 42 daa) and were associated with specific tissues and processes. A similar experiment on developing caryopses grown with dry and/or hot environmental treatments was also analysed, using the profiles established in the first experiment to show that most environmental treatment effects on transcription were due to acceleration of development, but that a few transcripts were specifically affected. Transcript abundance profiles in both experiments for nine selected known and putative wheat transcription factors were independently confirmed by real time RT-PCR. These expression profiles confirm or extend our knowledge of the roles of the known transcription factors and suggest roles for the unknown ones. Conclusion: This transcriptome data will provide a valuable resource for molecular studies on wheat grain. It has been demonstrated how it can be used to distinguish general developmental shifts from specific effects of treatments on gene expression and to diagnose the probable tissue specificity and role of transcription factors

Identification, release and olfactory detection of bile salts in the intestinal fluid of the Senegalese sole (Solea senegalensis)

Olfactory sensitivity to bile salts is wide-spread in teleosts; however, which bile salts are released in suYcient quantities to be detected is unclear. The current study identiWed bile salts in the intestinal and bile Xuids of Solea senegalensis by mass spectrometry–liquid chromatography and assessed their olfactory potency by the electro-olfactogram