Presence Of Tween Research Articles

Unveiling the role of solubilization of metformin hydrochloride assimilated in nonionic surfactants mediated mixed micellar assemblies

This study examines the distribution of an antidiabetic drug metformin hydrochloride (MNH) between water and mixed micellar environments produced by nonionic surfactants Tween 80 (TW-80) and Triton X-100 (TX-100). In our research, we described the UV–visible absorption spectra of a drug at various surfactant concentrations above and below critical micelle concentration (CMC). When employing TX-100, the absorbance spectra appeared to shift towards shorter wavelengths (blue shift) and there was an increase in absorbance intensity (hyperchromic shift), while using Tween 80, absorbance intensity increased (hyperchromic shift). We estimated the partition coefficient (Kx) from differential absorption data and utilized it to derive the free energy of partition (∆Gp). The partition coefficient in a single micellar system was found to be 7.82×106 and 1.79×106 in the presence of TW-80 and TX-100, respectively. The partition coefficient for the MNH/TW-80 system in a mixed micellar system reaches its maximum value of 1.08×107 when TX-100 is present at 1.26×106 M, indicating a considerable increase in the solubilizing power of micelles. The results showed that mixed micelles of TX-100/TW-80 were more effective for the solubilization of MNH than their individual micelles. It was crystal clear from the negative values of ∆Gb that binding is also spontaneous.

Design of Delivery Systems (Nanoemulsions and Biopolymer Nanoparticles) of Cloves Essential Oil: Preparation, Characterizations, Study the Release, and Antioxidant Activity

Abstract BACKGROUND: Clove oil has a wide range of therapeutic and pharmaceutical applications. It is also used in the manufacture of pesticides and antifungals, as well as many advantages. The study aims to improve the properties of essential oils, especially clove oil, and make them more stable by the design of delivery systems (nanoemulsions and biopolymer nanoparticles). METHODS: Clove oil was mixed with water in the presence of tween-20 as a polysorbate-type nonionic surfactant, and then carboxymethyl cellulose was added with different ratios of glycerin as a cross-linking agent. The formation of the clove nanogel was tested by spectrophotometric assay 2.2.2 Fourier transform infrared spectroscopy (FT-IR), Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR), dynamic light scattering (DLS), and morphology method field emission scanning electron microscopy (FESEM), also the rate of clove oil release during different periods, and hemolytic and antioxidant activity were tested. RESULTS: The nanoparticles were demonstrated by DLS and FESEM. The polydispersity index value was 0.279, indicating good monodispersity and good stability, while higher release values were obtained when glycerol was not present as a cross-linker. In addition to the higher antioxidant, values of the clove oil nano emulsion (CNE) have a maximum inhibition of 65% at a concentration of 100 μg/mL, whereas clove nano-gel (CNG) at the same concentration exhibited 59.2% inhibition. The calculated IC50 values of CNG and CNE were 6.58 and 3.25 μg/mL, respectively. CONCLUSION: The study proved through the results obtained that nanocomposites help stabilize components, especially volatile oil, which increases their effectiveness.

PAH bioremediation with Rhodococcus rhodochrous ATCC 21198: Impact of cell immobilization and surfactant use on PAH treatment and post-remediation toxicity

Polycyclic aromatic hydrocarbons (PAHs) are prevalent environmental contaminants that are harmful to ecological and human health. Bioremediation is a promising technique for remediating PAHs in the environment, however bioremediation often results in the accumulation of toxic PAH metabolites. The objectives of this research were to demonstrate the cometabolic treatment of a mixture of PAHs by a pure bacterial culture, Rhodococcus rhodochrous ATCC 21198, and investigate PAH metabolites and toxicity. Additionally, the surfactant Tween ® 80 and cell immobilization techniques were used to enhance bioremediation. Total PAH removal ranged from 70–95% for fluorene, 44–89% for phenanthrene, 86–97% for anthracene, and 6.5–78% for pyrene. Maximum removal was achieved with immobilized cells in the presence of Tween ® 80. Investigation of PAH metabolites produced by 21198 revealed a complex mixture of hydroxylated compounds, quinones, and ring-fission products. Toxicity appeared to increase after bioremediation, manifesting as mortality and developmental effects in embryonic zebrafish. 21198′s ability to rapidly transform PAHs of a variety of molecular structures and sizes suggests that 21198 can be a valuable microorganism for catalyzing PAH remediation. However, implementing further treatment processes to address toxic PAH metabolites should be pursued to help lower post-remediation toxicity in future studies.

In-silico characterization of a thermophilic serine protease via homology modeling, docking and molecular dynamics simulations

One of the major categories of industrial enzymes, proteases is crucial to the survival of living things. The purpose of this research was to newly thermostable protease from the thermophilum Geobacillus stearothermophilus. With the conserved catalytic tetrad, protease (Protease JJ) is closely related to the serine proteases from the subtilisin S8 peptidase, according to phylogenetic tree analysis. The tertiary structure of Protease JJ was predicted structurally using RoseTTAFold, and it is a sandwich structure overall. Homology modeling validation showed Protease JJ was modeled in X-ray’s protein areas, and it has gained a favored Ramachandran graph regarding Phi/Psi angels. Protease JJ showed structure stability through Molecular dynamics simulation in the presence of Tween20 and Methanol in 1% concentration. Also, Protease JJ exhibited thermal stability at 60 to 90 °C so that amino acid exposure of Protease JJ was low and constant throughout the MD simulation. Docking results of Protease JJ with BSA and βcasein were simulated via MD and it was found that Protease JJ could interact with both BSA and βcasein strongly. MM/PBSA analysis showed Protease JJ may be involved via more amino acids with BSA as well as established more interaction hydrogen bonds. Overall, evidence suggests Protease JJ probably has merit for future experimental investigation as a thermostable protease.Communicated by Ramaswamy H. Sarma

Tween-80 enhanced biodegradation of naphthalene by Klebsiella quasipneumoniae.

Accidental spillage of petroleum products and industrial activities result in various hydrocarbons in the environment. While the n-hydrocarbons are readily degraded, the polycyclic aromatic hydrocarbons (PAHs) are recalcitrant to natural degradation, toxic to aquatic life and are responsible for diverse health challenges in terrestrial animals; suggesting the need for faster and more eco-friendly ways of removing PAHs from the environment. In this study, the surfactant tween-80 was used to enhance a bacterium's intrinsic naphthalene biodegradation activity. Eight bacteria isolated from oil-contaminated soils were characterised using morphological and biochemical methods. The most effective strain was identified as Klebsiella quasipneumoniae using 16S rRNA gene analysis. High-Performance Liquid Chromatography (HPLC) analyses showed that the detectable concentration of naphthalene was decreased from 500 to 157.18μg/mL (67.4%) after 7 d in the absence of tween-80, while 99.4% removal was achieved in 3 d in the presence of tween-80 at 60μg/mL concentration. The peaks observed in the Fourier Transform Infra-Red Spectroscopy (FTIR) spectrum of control (naphthalene), which were absent in that of the metabolites, further established naphthalene degradation. Furthermore, Gas Chromatography-Mass Spectrometer (GCMS) revealed metabolites of single aromatic ring, such as 3,4-dihydroxybenzoic acid 4-hydroxylmethylphenol, which confirmed that the removal of naphthalene is by biodegradation. Tyrosinase induction and laccase activities suggested the involvement of these enzymes in naphthalene biodegradation by the bacterium. Conclusively, a strain of K. quasipneumoniae that can effectively remove naphthalene from contaminated environments has been isolated, and its biodegradation rate was doubled in the presence of non-ionic surfactant, tween-80.

Purification and characterization of moderately thermostable raw-starch digesting α-amylase from endophytic Streptomyces mobaraensis DB13 associated with Costus speciosus.

Endophytic actinobacteria are known to produce various enzymes with potential industrial applications. Alpha-amylase is an important class of industrial enzyme with a multi-dimensional utility. The present experiment was designed to characterize a moderately thermostable α-amylase producing endophytic Streptomyces mobaraensis DB13 isolated from Costus speciosus (J. Koenig) Sm. The enzyme was purified using 60% ammonium sulphate precipitation, dialysis, and Sephadex G-100 column chromatography. Based on 12% SDS-PAGE, the molecular weight of the purified α-amylase was estimated to be 55 kDa. The maximum α-amylase activity was achieved at pH 7.0, 50°C and it retained 80% of its activity at both pH 7.0 and 8.0 after incubation for 2 h. The α-mylase activity is strongly enhanced by Ca2+, Mg2+, and inhibited by Ba2+. The activity remains stable in the presence of Tween-80, SDS, PMSF, and Triton X-100; however, β-mercaptoethanol, EDTA, and H2O2 reduced the activity. The kinetic parameters Km and Vmax values for this α-amylase were calculated as 2.53 mM and 29.42 U/mL respectively. The α-amylase had the ability to digest various raw starches at a concentration of 10 mg/mL at pH 7.0, 50°C, where maize and rice are the preferred substrates. The digestion starts after 4 h of incubation, which reaches maximum after 48 h of incubation. These results suggest that S. mobaraensis DB13 is a potential source of moderately thermostable α-amylase enzyme, that effciently hydrolyzes raw starch. It suggesting that this α-amylase is a promising candidate to be use for industrial purposes.

Effect of Surfactants with Different Hydrophilic–Lipophilic Balance on the Cohesive Force between Cyclopentane Hydrate Particles

Effective control of the cohesive force between hydrate particles is the key to prevent their aggregation, which then causes pipeline blockage. The hydrophilic–lipophilic balance (HLB) value of surfactants was proposed as an important parameter for the evaluation and design of hydrate anti-agglomerants. A microscopic manipulation method was used to measure the cohesive forces between cyclopentane hydrate particles in the presence of Tween and Span series surfactants with different HLB values; moreover, the measured cohesive force was compared with the results of calculations based on the liquid bridge force model. Combined with the surface morphology and wettability of the hydrate particles, we analyzed the mechanism by which surfactants with different HLB values influence the cohesion between hydrate particles. The results show that for both Tween (hydrophilic, HLB > 10) and Span (hydrophobic, HLB < 10) surfactants, the cohesive force between cyclopentane hydrate particles decreased with decreasing HLB. The experimental results were in good agreement with the results of calculations based on the liquid bridge force model. The cohesive force between hydrate particles increased with increasing concentration of Tween surfactants, while in the case of the Span series, the cohesive force decreased with increasing surfactant concentration. In the formation process of cyclopentane hydrate particles, the aggregation of low-HLB surfactant molecules at the oil–water or gas–water interface increases the surface roughness and hydrophobicity of the hydrate particles and inhibits the formation of liquid bridges between particles, thus reducing the cohesion between particles. Therefore, the hydrate aggregation and the associated blockage risks can be reduced.

Synthesis of copper nanosquare and nanorectangular using novel precursor (substituted benzoic acid complexes)

The ligand 3,4,5-trimethoxybenzoic acid was used to prepare a series of its complexes with divalent manganese, cobalt, nickel and copper ions in a molar ratio of 2 ligand: 1 metal to give the complexes of formula [M(TMA)2].xH2O, M = Mn, Co; x = 0 or M = Ni, Cu; x = 2. The prepared complexes were characterized using FTIR, UV–Vis, CHN, molar conductivity, thermal analysis and magnetic susceptibility. The measurements proved that the TMA anion has the ability to bind with the studied metals by the behaviour of the bidentate chelate through the oxygen atoms of the carboxylic group. The complex [Cu(TMA)2] was used as a starting material to prepare copper nanoparticles using ascorbic acid in the presence of tween as a dispersant, which was characterized by X-ray diffraction and TEM technique. The TEM measurement proves that the copper was prepared with nanoscale with rectangular (53*70 nm) and square (30–32*30–32 nm) nanoparticles and the X-ray diffraction measurement proved that the formed copper was of high purity.

Mechanism of trichloroethylene degradation in Fe(II)-activated peroxymonosulfate coupled with citric acid system in the presence of surfactants.

This study demonstrated that peroxymonosulfate (PMS) activated by Fe(II)/citric acid (CA) could effectively degrade trichloroethylene (TCE) in the presence of Tween-80 (TW-80) or sodium dodecyl sulfate (SDS). Significant TCE removal of 91.6% (90.1%) with 1.3g L-1 TW-80 (2.3g L-1 SDS) were achieved at the PMS/Fe(II)/CA/TCE molar ratio of 4/4/4/1 (20/20/20/1). TCE degradation could be greatly elevated by Fe(II) and CA addition, while the existence of surfactants restrained TCE removal and the inhibitory effect increased with the higher surfactant concentration. The tests of the electron paramagnetic resonance (EPR) and reactive radicals scavenging experiments proved that sulfate radical (SO4-•), hydroxyl radical (HO•), and superoxide radical (O2-•) were responsible for TCE degradation and SO4-• acted as the major one. The influences of initial solution pH and inorganic anions k(Cl- and HCO3-) on TCE removal were also investigated. Eventually, TCE removal in actual groundwater tests with surfactants confirmed that the PMS/Fe(II)/CA process has a huge potential of practical application in remediating the groundwater contaminated by TCE after the pretreatment by solubilization using surfactants.

Insights into carbon dioxide hydrate formation, fluid type, and agglomeration in the system with or without tween-80

In this work, the flow of carbon dioxide (CO2) hydrate slurry is systematically investigated by analyzing its rheological behavior, apparent viscosity, and crystal shape. The results show that blocking is easy to occur in the pure water system, while no blockage is observed from the system containing Tween-80. Besides, we confirm that the hydrate slurry formed in the pure water system is a dilatant fluid with shear-thickening behavior. However, that obtained from the system containing Tween-80 are pseudoplastic fluids with shear-thinning behavior. The time development of hydrate slurry flow in the system with or without Tween-80 showed that the shear-thinning behavior is a key factor in preventing the hydrate slurry from blockage. In addition, in the presence of Tween-80, hydrates will form on the surface of the bubble. These hydrates are easily dispersed on top of the liquid phase and will not adhere to the top wall of the pipeline. However, in pure water, a dense adhesive layer is observed on the top of the pipeline, which will reduce the flow area in the pipeline, increasing the flow resistance. Overall, the main role of Tween-80 in preventing hydrates from aggregation includes two aspects, (1) changing the type of fluid from dilatant to pseudoplastic; (2) providing bubbles for hydrate formation. The addition of defoamer(BK601) will reduce the Tween-80′s effects in preventing hydrates by reducing shear-thinning behavior and the amount of bubbles.

Bacteria and fungi mediated degradation of poly aromatic hydrocarbons and effect of surfactant Tween-80

ABSTRACT Microorganisms (17 bacteria and 3 fungi) isolated from crude oil-contaminated soils were evaluated for degradation of five polyaromatic hydrocarbons (PAHs), both in the absence (-T80) and the presence of surfactant Tween-80 (+T80) at a 10 mg L−1 concentration of each PAH. Results of the heat map and Tukey HSD revealed that highest PAH degradation was observed by Kocuria rosea in +T80 treatment. Degradation (%) of individual PAH (-T80, +T80) was naphthalene: 96.6, 98.9; fluorene: 93.8, 95.1; phenanthrene: 58.1, 70.9; anthracene: 19.9, 32.5 and pyrene: 13.8, 54.7, respectively. Tukey HSD further revealed that all three fungi Trichoderma atroviride, Aspergillus nidulans and Aspergillus sydowii showed almost similar degradation of selected PAH. Based on degradation ability, consortia of K. rosea and A. sydowii were used for PAH degradation at 10, 50 and 100 mg L−1 in the presence of Tween-80. Results suggested that PAH degradation slowed down with the increase in the concentration. PAH degradation products phthalic acid and anthrone or phenanthrene-9,10 oxide or 9-phenanthrol were identified as a product of degradation. Bacterial strain Arthrobacter pascens, Pseudomonas aeruginosa, Bacillus megaterium, Bacillus sp., Bacillus niacini and Bacillus siamensis showed high fluorescence diacetate (FDA) hydrolase activity, whilst A. pascens, K. rosea, Pseudomonas sp. and B. niacini showed a significant soluble protein content.

The role of Tween 80 and SDS in the kinetics of semi-clathrate hydrates formation for carbon dioxide capture from flue gas

ABSTRACT The present study focuses on integrated experimental evaluation of a concentration effect in nonionic and anionic surfactants on semi-clathrate hydrates formation during the capture low-pressure carbon dioxide from the flue gas (N2 (83.13 mol.%)/CO2 (16.87 mol.%)). Semi-clathrate hydrates of tetra n-butylammonium bromide (TBAB) are favorable materials with phase changes due to their moderate hydrate formation conditions. The kinetics of CO2-N2-TBAB semi-clathrate hydrate formation was studied in the presence and absence of Tween-80 as a nonionic surfactant and sodium dodecyl sulfate (SDS) as an anionic one. The experiments were performed in a stirred batch reactor at a constant temperature of 273.55 K and an initial pressure of 2.1 MPa. 5.0 wt.% TBAB’s aqueous solutions were tested both in the absence of surfactants and in presence of Tween-80 and SDS at different concentrations (500, 1500, 3000 ppm). The separation factor and recovery for CO2 at low pressure were in situ controlled depending on the surfactant concentration. Adding 1500 ppm of Tween-80 provided optimal conditions for the СО2/N2 separation process; the separation factor was 9.5, the СО2 recovery was 53.1%.

Peptide-Based Hydrogels and Nanogels for Delivery of Doxorubicin.

IntroductionThe clinical use of the antitumoral drug doxorubicin (Dox) is reduced by its dose-limiting toxicity, related to cardiotoxic side effects and myelosuppression. In order to overcome these drawbacks, here we describe the synthesis, the structural characterization and the in vitro cytotoxicity assays of hydrogels (HGs) and nanogels (NGs) based on short peptide sequences loaded with Dox or with its liposomal formulation, Doxil.MethodsFmoc-FF alone or in combination with (FY)3 or PEG8-(FY)3 peptides, at two different ratios (1/1 and 2/1 v/v), were used for HGs and NGs formulations. HGs were prepared according to the “solvent-switch” method, whereas NGs were obtained through HG submicronition by the top-down methodology in presence of TWEEN®60 and SPAN®60 as stabilizing agents. HGs gelation kinetics were assessed by Circular Dichroism (CD). Stability and size of NGs were studied using Dynamic Light Scattering (DLS) measurements. Cell viability of empty and filled Dox HGs and NGs was evaluated on MDA-MB-231 breast cancer cells. Moreover, cell internalization of the drug was evaluated using immunofluorescence assays.ResultsDox filled hydrogels exhibit a high drug loading content (DLC=0.440), without syneresis after 10 days. Gelation kinetics (20–40 min) and the drug release (16–28%) over time of HGs were found dependent on relative peptide composition. Dox filled NGs exhibit a DLC of 0.137 and a low drug release (20–40%) after 72 h. Empty HGs and NGs show a high cell viability (>95%), whereas Dox loaded ones significantly reduce cell viability after 24 h (49–57%) and 72 h (7–25%) of incubation, respectively. Immunofluorescence assays evidenced a different cell localization for Dox delivered through HGs and NGs with respect to the free drug.DiscussionA modulation of the Dox release can be obtained by changing the ratios of the peptide components. The different cellular localization of the drug loaded into HGs and NGs suggests an alternative internalization mechanism. The high DLC, the low drug release and preliminary in vitro results suggest a potential employment of peptide-based HGs and NGs as drug delivery tools.

Efficient kinetic resolution of para-chlorostyrene oxide at elevated concentration by Solanum lycopersicum epoxide hydrolase in the presence of Tween-20

A putative Solanum lycopersicum epoxide hydrolase, SlEH2, was discovered based on computer-aided analysis. Then, its encoding gene (sleh2) was expressed in E. coli BL21(DE3). The substrate spectrum assay exhibited that E. coli/sleh2, an E. coli transformant expressing SlEH2, possessed the activity of 74.8 U/g wet cell and enantiomeric ratio (E) of 145 towards racemic (rac-) para-chlorostyrene oxide (4a). The scale-up kinetic resolution of 400 mM rac-4a was conducted using 200 mg/mL wet cells of E. coli/sleh2 in the presence of 1% (v/v) Tween-20, retaining (R)-4a with 98.4% ees and 47.1% yields while affording (R)-4b with 92.0% eep and 49.5% yieldp.

Degradation of trichloroethylene in aqueous solution by sodium percarbonate activated with Fe(II)-citric acid complex in the presence of surfactant Tween-80

The degradation performance of trichloroethylene (TCE) by sodium percarbonate (SPC) activated with citric acid (CA) chelated Fe(II) in the presence of nonionic surfactant Tween-80 was investigated. The addition of CA successfully prevented the precipitation of iron and facilitated TCE degradation. However, Tween-80 had an inhibitory effect on TCE degradation mainly due to the competition of ∗OH between Tween-80 and TCE. The effect of SPC and Fe(II) dosage on TCE degradation was also explored and the results displayed that 87.2% of TCE could be degraded in 15 min at the SPC/Fe(II)/CA/TCE molar ratio of 3/4/2/1. Free radical probe tests confirmed that both O2−∗ and ∗OH were generated in the SPC/Fe(II)/CA system. Free radical scavenging tests implied that the degradation of TCE in the SPC/Fe(II)/CA system was mainly attributed to ∗OH, while O2−∗ was only partially involved in the degradation of TCE. In addition, TCE removal was suppressed with the raising of the initial solution pH from 3.0 to 9.0. The actual groundwater (containing Tween-80) tests confirmed that 93.2% of TCE degradation could be achieved at the SPC/Fe(II)/CA/TCE molar ratio of 30/40/10/1 and strongly demonstrated that the SPC/Fe(II)/CA process has potential for the in situ treatment of TCE contaminated groundwater in the presence of surfactant Tween-80. In conclusion, TCE degradation by Fe(II) activated SPC system in the presence of Tween-80 can be significantly enhanced with the addition of CA, and this finding offers an innovative direction for removing chlorinated organic contaminants from groundwater in contaminated site after surfactant solubilization treatment.

Determination of Melphalan by Micelle Enhanced Spectrofluorimetric Method: Application to Content Uniformity Testing and Human Plasma

Abstract This manuscript describes a responsive, rapid, validated and economical spectrofluorimetric method for determination of Melphalan in its pharmaceutical dosage forms and spiked human plasma. The proposed method is relied on the investigation of fluorescence action of Melphalan in Tween-80 micellar system. The Melphalan shows strong native fluorescence at λem 365 nm upon excitation at λex 265 nm in Tween-80 system. There was good enhancement (1.68 fold) in fluorescence intensity in the presence of Tween-80. The proposed approach has a good linearity in the concentration range of 0.2 μg/mL–2 μg/mL. The lower limit of detection and that of quantitation was 0.03 μg/mL and 0.08 μg/mL respectively. The developed method has been validated and applied for content uniformity testing of Melphalan medicines available on the market and Melphalan spiked human plasma samples. The results are statistically compared and were found to be in good agreement to those obtained by comparison methods.

Efficient removal of trichloroethylene in surfactant amended solution by nano Fe0-Nickel bimetallic composite activated sodium persulfate process

Trichloroethylene (TCE) is chloride organic solvent used in industrial process and frequently detected as one of contaminants in groundwater. In present study, nano zero valent iron-nickel composite (nZVI-Ni) was prepared successfully by ion exchange process and investigated as a proficient sodium persulfate (SPS) activator for the removal of TCE in Fenton-like oxidation system. The physico-chemical characteristics, structure, and surface morphology of the prepared nZVI-Ni nanocomposite was analyzed through energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), N2 adsorption-desorption, transition electron microscopy (TEM), X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS). The experimental results obtained from batch tests in lab showed that more than 95% of TCE could be removed efficiently at nZVI-Ni/SPS/TCE molar ratio of 4/4/1 within 120 min at 20 °C. Further scavenging tests were designed to examine the presence of HO, SO4− and O2− radicals and verified the major role of HO radical in the nZVI-Ni/SPS system for the complete removal of TCE. Moreover, the generation of HO radicals in the system was confirmed through electrons paramagnetic resonance (EPR) of nZVI-Ni composite. The influence of surfactants on TCE removal was tested and the results showed that the percentage removal of TCE was recorded as 97.75%, 95.63% and 77.50% in the presence of Tween-80, BRIJ-35 and TX-100 surfactants at the nZVI-Ni/SPS/TCE molar ratio of 80/80/1, respectively. Results of TCE degradation in real groundwater revealed that nZVI-Ni can be applicable and is a promising catalyst for TCE removal in in-situ chemical oxidation (ISCO) practice. In Summary, these significant findings strongly demonstrate the feasibility and potential of nZVI-Ni activated SPS process as an alternative technique for TCE contaminated groundwater remediation.

Probabilistic Limit of Detection for Ricin Identification Using a Shotgun Proteomics Assay.

Robust and highly specific methods for the detection of the protein toxin ricin are of interest to the law enforcement community. In previous studies, methods based on liquid chromatography-tandem mass spectrometry shotgun proteomics have been proposed. The successful implementation of this approach relies on specific data evaluation criteria addressing (1) the quality of the mass spectrometric data, (2) the confidence of peptide identifications (peptide-spectrum matches), and (3) the number and sequence specificity of peptides detected. We present such data evaluation criteria and use a novel approach to establish the limit of detection for this ricin assay. Specifically, we use logistic regression to determine the probability of detection for individual ricin peptides at different concentrations. We then apply basic rules from probability theory, combining these individual peptide probabilities into an overall assay limit of detection. This procedure yields an assay limit of detection for ricin at 42.5 ng on column or 21.25 ng/μL for a 2-μL injection. We also show that, despite the conventional wisdom that detergents are deleterious to mass spectrometric analyses, the presence of Tween-20 did not prevent detection of ricin peptides, and indeed assays performed in buffers that included Tween-20 gave better results than assays performed using other buffer formulations with or without detergent removal.

Development of an eco-friendly deinking process for the production of bioethanol using diverse hazardous paper wastes

Bioethanol production using paper wastes seems a promising approach towards sustainable energy, but mainly hindered by hazardous ink. Therefore, in our experimental plan various methods were applied for the deinking of waste newspapers, laser printed papers and examination papers. A newly designed paper pulper reduced the pulping time from 6 h to 2 h. Cellulase (15 FPU/g) from Aspergillus oryzae MDU-4 was found effective for the deinking of newspapers, whereas laccase isozymes (150 U/g) from Ganoderma lucidum MDU-7 along with 2 mM HOBt was preferred for the ink removal and degradation from the examination papers. Ozonation in the presence of Tween-80 was found to be efficient in the removal of toxic toners used in laser printing papers. The biologically and physically deinked papers, studied with the help of SEM, TEM, FTIR, and XRD analysis revealed significant changes in the chemical and surface structure. Moreover, the saccharification of deinked papers with the help of an enzymatic consortium of Trichoderma citrinoviride MDU-1 resulted in 305 mg/g, 377 mg/g, and 409 mg/g release of sugars from the newspaper, examination paper, and laser printed paper, respectively. Finally, the enzymatic hydrolysates fermented with Saccharomyces cerevisiae NCIM-3640 produced 3.35 g/L ethanol, with 40.85% ethanol yield.

Synergistic Inhibition Effect of 9-(4-Chlorophenyl)-1,2,3,4-tetrahydroacridines and Tween-80 for Mild Steel Corrosion in Acid Medium

The synergistic inhibition effect of Tween-80 and 1,2,3,4-tetrahydroacridines, including 9-(4-chlorophenyl)-2-methyl-1,2,3,4-tetrahydroacridine (CMT) and ethyl 9-(4-chlorophenyl)-1,2,3,4-tetrahydroacridine-2-carboxylate (ECT), on mild steel corrosion in 1 M HCl was investigated by using weight loss tests, electrochemical techniques, and surface morphology (SEM/SECM). The results indicated that the mixtures of CMT/ECT and Tween-80 strongly inhibit the corrosion of mild steel compared to individual inhibitors, and the adsorption mode belongs to the Langmuir isothermal type. Electrochemical measurements showed that the mixtures were mixed-type inhibitors, and a double-layer structure film with the inner layer of Tween-80 and the outer layer of CMT/ECT was formed on the steel surface. That the calculated synergistic parameter value was larger than unity illustrates that the enhancement of inhibition in the presence of Tween-80 is only due to synergistic action. Surface analysis techniques (SEM/SECM) verified ...