Phosphatase activities of fractions of the venom of Renard's viperVipera ursini renardi

The separation of the venom of Renard's viper by filtration through Sephadex G-75 gel has been performed and phosphatase activities have been determined in the fractions and in the course of separation. The bulk of the activity of the phosphatases investigated was concentrated in the high-molecular-weight fractions I and II. A correlation has been found in the distribution of the DNase and ATP-pyrophosphatase activities with the phosphodiesterase activity in the venom fractions. There is no correlation in the distribution of the RNase and phosphodiesterase activity.     

Modification in physical properties of organo clay filled polyurethane nanocomposites

Polyurethane (PU) have been prepared by using polyether polyol (jagropol oil) and 1,6-hexamethylene diisocyanate (HMDI) as a cross-linker. The organically modified montmorillonite clay (o-MMT) is well dispersed into urethane matrix by in-situ polymerization method. A series of PU/o-MMT nanocomposites have been prepared by varying amounts viz., 1, 3, 5 and 6 wt % of nanoclay. The mechanical properties such as tensile strength, percentage elongation at break and tensile modulus of the composites were experimentally determined. The swelling behavior of the composites has been studied in different organic solvents. It was noticed that the swelling data of the composites significantly depends on the solubility parameters of the solvents. Microcrystalline parameters such as, lattice strain (g in %), average number of unit cells (〈N〉) in direction perpendicular to Bragg plane, surface weighted crystal size (D _s) and interplanar distance (d _hkl ), were calculated from X-ray patterns. These parameters were computed using Exponential asymmetric column length distribution functions. Morphological features of cryofractured PU/o-MMT composites were also analyzed using scanning electron microscopy (SEM).     

Polysaccharides ofEremurus. X. Characteristics of the polysaccharides ofEremurus lactiflorus andE. luteus

Water-soluble polysaccharides have been isolated from two species ofEremurus — E. lactiflorus andE. luteus — with yields of 13.5% and 20.5%, respectively. They contained mainly glucose and mannose in ratios of 1:5 and 1:3.1. The polysaccharides ofE. lactiflorus were separated from a column of DEAE-cellulose. The yield of neutral fraction was 10.3%. Gel filtration of the polysaccharides on Sephadex G-200 showed their polydispersity. Homogeneous fractions were obtained by fractional precipitation with ethanol. They have been characterized with respect to monosaccharide composition, molecular weight, and IR spectra.     

Extraction and chemical investigation of jute (Corchorus olitorius,Linn.) seed protein

Studies were made on the protein solubility of deoiled jute (Corchorus olitorius, Linn.) seed in aqueous solution over various pHs and in different concentrations of NaCl at pH 8.0. Chemical analysis of the seed protein showed 16 amino acids, of which 9 were essential. Gel filtration on Sephadex G-200 revealed the presence of four components, and their molecular weights were determined by two standard methods. Extractable jute seed proteins in salt solution were separated into six fractions electrophoretically (SDS-PAGE). The molecular weights of the six fractions were found to be 118,000; 103,000; 96,000; 67,500; 48,500; and 15,000.     

Study of gamma radiation induced damages and variation of oxygen enhancement ratio with radiation dose using Saccharomyces cerevisiae

In the present study, an attempt has been made to quantify Oxygen Enhancement Ratio (OER) and variation of OER as a function of dose with experimental and theoretical formulations using Saccharomyces cerevisiae D7, X2180 and rad 52. The study confirms that, the variation of OER with dose depends upon type of cell and repair proficiency of cells. A theoretical model has been formulated to estimate OER values. With the help of this model, OER value for any dose can be calculated in the exponential region of the survival curve without actually extending the experiment in that dose region.     

Radiolysis of synthetic oils based on polyalphaolefins

Radiolysis of a number of synthetic oils based on polyalphaolefins (WM-5, PAO-2, PAO-4, PAO-6, and PAO-8) has been studied. The radiation-chemical yields of hydrogen, low-and high-molecular-weight products (up to C₁₀₀) are reported. So, for PAO-4 oil (composition of the oil: 80 % of C₃₀, 13 % of C₄₀, 3 % of C₅₀) the yields of products of radiolysis (1/100 eV) make: \(G_{H_2 } \) = 3.7, G _{= 2.9, G C30 = ?3.3, G C40 = ?0.3, G C50 = 0.21, G C60 = 0.33, G >C60 = 0.5.}     

In Situ Characterization of Proteins Using Laserspray Ionization on a High-Performance MALDI-LTQ-Orbitrap Mass Spectrometer

The MALDI-LTQ-Orbitrap XL mass spectrometer is a high performance instrument capable of high resolution and accurate mass (HRAM) measurements. The maximum m/z of 4000 precludes the MALDI analysis of proteins without generating multiply charged ions. Herein, we present the study of HRAM laserspray ionization mass spectrometry (MS) with MS/MS and MS imaging capabilities using 2-nitrophloroglucinol (2-NPG) as matrix on a MALDI-LTQ-Orbitrap XL mass spectrometer. The optimized conditions for multiply charged ion production have been determined and applied to tissue profiling and imaging. Biomolecules as large as 15 kDa have been detected with up to five positive charges at 100 K mass resolution (at m/z 400). More importantly, MS/MS and protein identification on multiply charged precursor ions from both standards and tissue samples have been achieved for the first time with an intermediate-pressure source. The initial results reported in this study highlight potential utilities of laserspray ionization MS analysis for simultaneous in situ protein identification, visualization, and characterization from complex tissue samples on a commercially available HRAM MALDI MS system. Graphical Abstract

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Ultrasensitive detection and identification of BRAF V600 mutations in fresh frozen,FFPE, and plasma samples of melanoma patients by E-ice-COLD-PCR

A number of molecular diagnostic methods have been developed for the detection and identification of mutations in tumor samples, which are important for the choice of treatment in the context of personalized medicine. For the treatment of metastatic melanoma, Vemurafenib is recommended for patients with BRAF V600 activating mutations. However, the different assays developed to date for the detection of these mutations lack sensitivity or specificity or do not allow a sequencing-based identification or validation of the mutation. Recently, enhanced improved and complete enrichment co-amplification at lower denaturation temperature-polymerase chain reaction (E-ice-COLD-PCR) has been developed as a sensitive method for the detection and identification of mutations in KRAS codons 12/13. Here, we present the first E-ice-COLD-PCR assay for the detection and identification of BRAF codon 600 mutations, which has a large dynamic range, as 25 pg to 25 ng can be used as DNA input without any reduction in mutation enrichment efficiency, and which can detect down to 0.01 % of mutated alleles in a wild-type background. The assay has been validated on fresh frozen, formalin-fixed paraffin-embedded (FFPE), and plasma samples of melanoma patients and has allowed the detection and identification of BRAF mutations present in samples appearing as wild type using standard pyrosequencing, endpoint genotyping, or Sanger sequencing. Thus, the BRAF V600 E-ice-COLD-PCR assay is currently one of the most powerful molecular diagnostic tools for the ultrasensitive detection and identification of BRAF codon 600 mutations.     

Polarography of hexavalent molybdenum in hypophosphorous acid solutions

The polarographic behaviour and determination of Mo(VI) in hypophosphorous acid solutions of concentrations varying from 0.1 to 5.0 mol l^?1 andT=25±0.1 °C have been investigated. It was shown that reduction of MoO ₄ ^2? takes place along a single or two waves depending upon the acid concentration. Microcoulometric experiments have been performed at the limiting region of the different waves obtained at different acid concentrations. A scheme for the mechanism of reduction occuring at theDME has been deduced. A method for analytical determination of Mo(VI) on both the micro- and macro-scales in hypophosphorous acid solutions has been reported. Analysis of a binary mixture Mo(VI)/Cd(II) and a tertiary mixture Mo(VI)/Cd(II)/Zn(II) in mol l^?1 hypophosphorous acid has been investigated.     

Production of indigotin in submerged culture using morchella nov. ES-1

A new strain of the fungusMorchella nov. ES-1 (ATCC 20951) that produces blue pigment in submerged culture has been isolated. The blue pigment was extracted by chloroform or ethyl acetate treatment. The crude extract when chromatographed yielded three fractions; a blue one has been identified by mass spectrometry as indigotin. Fermentation studies using enriched media revealed that maximum accumulation of indigotin in culture was approx 24 mg/L in 168 h.     

A cathode for solid polymer electrolyte fuel cells: Designing the optimal structure of the active layer

The complete computer simulation of the cathodic active layer with solid polymer electrolyte (Nafion) is carried out. The active layer structure can be described by 8 parameters. In designing the optimal structure, it is shown that to provide the high overall characteristics of the cathode and save the catalyst, 0.5 of the active layer volume should be set aside for the support grains (agglomerates of carbon particles covered with platinum and containing Nafion incorporations and microvoids). Protons and oxygen molecules must be supplied to the active layer by means of peculiar combined percolation clusters. The latter consist of a combination of support grains with either Nafion grains (to produce “protonic” clusters) or grains-voids (to afford “gas” clusters). The volume fractions of Nafion grains and grain-voids are assumed to be 0.25 and 0.25. The computer simulation of the support grain structure is also carried out. Their composition, i.e., the volume fractions of the carbon component (g _e), Nafion (g _ii), and microvoids (g _gg), is varied. The support grains play the key role in the active layer functioning. It is impossible to organize three full-value percolation clusters (electronic, protonic, and gas); hence, one has to have one or two combined clusters in the active layer. Thus the double load fells on the support grains. Their optimal structure should not only sustain the transport of protons and electrons in the active layer but also create the best conditions for the electrochemical process in each grain. The maximum current I _max (realized upon reaching the optimal active layer thicknesses Δ*) is calculated. The dependences of I _max and Δ* on the main parameters characterizing the support grains (g _e and g _ii) are analyzed. Here, two goals are sought: (1) to obtain the high currents, (2) to provide the low consumption of platinum per power unit. To solve the first problem, one has to work with high values of g _e. The second problem requires the opposite: the values of g _e must be minimal possible.     

Functional Microgels Assisted Tryptic Digestion and Quantification of Cytochrome c Through Internal Standard Mass Spectrometry

Quantitation of cytochrome c (Cyt c) in cell lysates through surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) using gold nanoparticles (Au NPs) as the matrix and GR-10 peptide as an internal standard has been demonstrated. To shorten digestion time, temperature sensitive microgels containing trypsin (TR) and Au NPs have been employed. As-prepared functional microgels (TR/Au NPs/MGs) allow digestion of Cyt c within 15 s under microwave irradiation. The internal standard SALDI-MS approach provides linearity (R² = 0.98) of MS signal ratio (I _1168.6/I _1067.6) of the tryptic digested peptide (m/z 1168.6) to GR-10 peptide (m/z 1067.6) against the concentration of Cyt c ranging from 25 to 200 nM, with a limit of detection (at a signal-to-noise ratio of 3) of 10 nM. This approach has been validated by the analysis of the lysates of HeLa cells, with an average concentration of 13.7?±?3.5 μM for cytoplasmic Cyt c. Increased concentrations of Cyt c in the HeLa cells treated with etoposide (a commercial drug) or carbon dots (potential drug) have been revealed through this simple, sensitive, and rapid SALDI-MS approach, supporting the drugs induced Cyt c-mediated apoptosis of the cells. This study has shown that this internal standard SALDI-MS approach holds great potential for cell study. Graphical Abstract

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Activity coefficient of hydrochloric acid in aqueous solutions of sodium chloride

Electromotive-force measurements of the cell $$Pt;H_2 \left( {g,1{\text{ }}atm} \right)|HCl\left( {{\text{m}}_A } \right),NaCl\left( {{\text{m}}_B } \right)|AgCl;Ag$$ have been made at temperatures between 5 and 45°C at values ofm _A+m _B of 0.1, 0.3809, 0.6729, and 0.8720 mole-kg^?1. The activity coefficients of HCl in HCl/NaCl mixtures and the Harned coefficients α₁₂ have been obtained. The change of α₁₂ with total molality is consistent with the existence of binary interactions between H⁺ and Na⁺ ions. The linear variation of the relative partial molal heat content with the fraction of NaCl in the mixture suggests that an analog of the Harned rule exists for this thermodynamic quantity.     

Electrometric study of uranyl(II) and beryllium(II) complexes of 2,2′-dimercapto diethyl ether

Complexation of uranyl(II) and beryllium(II) ions with 2,2′-dimercaptodiethyl ether has been studied in 40% ethanolic media by potentiometric and conductometric titration techniques revealing the formation of an 1∶1 complex in either case. The stability constants of the complexes have been determined at ionic strength μ=0.1M (NaClO₄) by applyingCalvin andMelchior's extension ofBjerrum's method. LogK _stab values are found to be 12.60, 11.96 at 25 °C and 12.55, 11.90 at 35 °C respectively. The values of ΔG, ΔH and ΔS for the complexation reactions determined at 25 °C are also reported.     

Modelling of catalytic hydrocracking and fractionation of refinery vacuum residue

The main objective of this work was to create a kinetic model of refinery vacuum residue hydrocracking and to monitor the impact of the operating conditions on the product yields. Data and yield measurements were gathered from a residual hydrocracking unit (RHC). Reaction temperature ranged from 401°C to 412°C at the pressure of 18–20 MPa. A simplified kinetic yield model was applied; where the feed and each product fraction are represented by one lump (reactant or product of cracking) represented by the number of pseudo-components. The product fractions were determined by fractional distillation of the output mixture from the reactor. The kinetic model includes eight reaction steps and the following six fractions: vacuum residue, vacuum distillate, gas oil, kerosene, naphtha, and gas. In addition, a model for hydrodesulphurisation has been proposed. The average relative deviation between model and experimental yields was 5.36 %, and that for the sulphur conversion model was 1.04 %. An Excel file with the kinetic model was implemented in the Aspen Plus program using a user-defined model of the reactor. This model allows to input/output data between the Aspen Plus and Excel programs. The Excel subroutine calculates the reaction kinetics of cracking from the set temperature and residence time, and distributes the products into 30 pseudo-components created in the Aspen Plus program. The remaining part of the RHC unit was simulated in the Aspen Plus environment. The effects of the reaction conditions such as temperature and residence time on the conversion of the feed and on the distillation curves of the output mixture from the reactor were investigated. The model was verified by comparison of the distillation curves of simulated and real products.     

KL 2,3 ionization in neon by electron impact in the range 1.5–50 keV: cross sections and alignment

We have measured the ratio of cross sections σ(KL _2,3)/σ(K) for neon for electron impact in the energy range ofE ₀=1.5 ... 50 keV via the intensity ofKL _2,3?LLL _2,3 Auger satellite lines relative to the intensity ofKL ₁ L _2,3 (³ P) diagram line. The experimental ratio decreases over the full range of energyE ₀ which is contrary to an earlier result by Carlson et al. We have also measured the alignment ofKL _2,3 ¹ P and³ P states via the angular distribution of Auger satellite intensity for the energy rangeE ₀=1.5 ... 4 keV, within experimental error we have found a zero alignment. The totalK Auger spectrum, measured forE ₀=40 keV and at the magic angle of emission ?=54.7°, has been decomposed into its components by using appropriate line shapes distorted by postcollision interaction. Finally, we discussed whether the lines observed at the high-energy side ofKL _2,3?LLL _2,3 Auger satellite lines can be interpreted as structures caused by an angular momentum exchange in the postcollision interaction predicted by Niehaus and Zwakhals.     

GC and GC-MS Studies on the Essential Oil and Thiophenes from Tagetes patula L.

The production and the composition of the compounds (mono-, sesquiterpenes and acetylenic thiophenes) obtained by the steam distillation of Tagetes patula L. have been investigated. The volatile oil was produced by steam distillation. GC was carried out on three types of stationary phase using flame ionization and mass selective detection. Percentage data were calculated by the area normalization method with very good repeatability (RSD below 5%). Oils from flower-heads were rich in β-caryophyllene (53.5%) and the leaves contained terpinolene in high concentration (21.1%). The main volatile component of the hairy roots and intact roots was 5-(3-buten-1-ynyl)-2,2'-bithienyl (BBT) yielding 28.5% and 44.0% in the oils. Three new minor constituents were identified as α-gurjunene, β-caryophyllene and (E)-β-farnesene. A flash chromatographic method was developed for the isolation of thiophenes from a solvent extract of intact roots. The collected fractions were screened by TLC and analyzed by GC-MS. Three thiophene fractions were obtained containing BBT, 5-(4-acetoxy-1-butynyl)-2,2'-bithienyl (BBTOAc) and 5-(4-hydroxy-1-butynyl)-2,2'-bithienyl (BBTOH).     

Miscibility and crystallization behaviors of stereocomplex-type poly(l- and d-lactide)/poly(methyl methacrylate) blends

Stereocomplex-poly(l- and d-lactide) (sc-PLA) and poly(methyl methacrylate) (PMMA) blends were prepared by solution blending at PMMA loadings from 20 to 80 mass%. The miscibility and crystallization behaviors of the blends have been studied in detail by differential scanning calorimeter. The single-glass transition temperatures (T _g) of the blends demonstrated that the obtained system was miscible in the amorphous state. It was observed that the crystallization peak temperature of sc-PLA/PMMA blends was marginally lower than that of neat sc-PLA at various cooling rates, indicating the dilution effect of PMMA on the sc-PLA component to restrain the overall crystallization process. In the study of isothermal crystallization kinetics, the reciprocal value of crystallization peak time ( \( t_{\text{p}}^{ - 1} \) ) decreased with increasing PMMA content, indicating that the addition of non-crystalline PMMA inhibited the isothermal crystallization of sc-PLA at an identical crystallization temperature (T _c). Moreover, the negative value of Flory–Huggins interaction parameter (χ ₁₂ = ?0.16) of the blend further indicated that sc-PLA and PMMA formed miscible blends.     

On the determination of HCl+ (A,v′) vibrational populations from HCl+ (A→X) fluorescence spectra: direct comparison between photoionization and penning ionization

Using a beam apparatus, we have measured the HCl⁺ (A,v′→X,v″) fluorescence spectra of HCl⁺ (A,v′) ions formed in HeI (58.4 nm), and NeI (73.6 nm) photoionization and, for the first time, in He (2³ S) Penning ionization under single collision conditions with a wavelength bandwidth around 1 nm. In addition, we have studied Ne (3s ³ P _{2, 0}) Penning ionization of HCl at three different collision energies. The procedure and the problems in extracting HCl⁺ (A,v′) vibrational populations from the data are discussed in some detail. Thedirect comparison of photoionization and Penning ionization data allows definitive conclusions to be drawn on the question whether final state interactions in the Penning reaction change the “nascent” vibrational population (determined by electron spectrometry); for He (2³ S)+HCl, such changes are shown to be absent within the experimental uncertainty (<±10%). For Ne (3s ³ P _{2, 0})+HCl, the HCl⁺ (A,v′=0, 1) populations are also found to be close to those measured by electron spectrometry and essentially independent of collision energy in the range 34–96 meV. From measurements of the fluorescence intensity as a function of HCl density, we have evidence for a fast loss of HCl⁺ (A,v′) ions in collisions with HCl (rate constant around 5·10^?9 cm³s^?1).     

Molar heats of transport of dilute aqueous HCl solutions: A potentiometric study

Heats of transport for dilute aqueous HCl solutions at 25°C have been determined from the measurements of thermoelectric powers of the thermocell $$(T){\text{ }}Ag{\text{ - }}AgCl/HCl(ag.)/Ag - AgCl{\text{ (T + }}\Delta {\text{T)}}$$ The variation of the heat of transport with concentration has been examined up to 0.04M and the molar heat of transport at infinite dilution obtained by extrapolation. Present experimental results may be summarized by the equation $${\text{Q}}^ * = {\text{ }}3397 - 3734I^{1/2} {\text{ + }}33610{\text{I}}^{{\text{3/2}}}$$ whereQ ^* is the heat of transport in cal-mole^?1 andI is the ionic strength.