Multi‐phosphorylation of the Intrinsically Disordered Unique Domain of c‐Src Studied by In‐Cell and Real‐Time NMR Spectroscopy

Intrinsically disordered regions (IDRs) are preferred sites for post‐translational modifications essential for regulating protein function. The enhanced local mobility of IDRs facilitates their observation by NMR spectroscopy in vivo. Phosphorylation events can occur at multiple sites and respond dynamically to changes in kinase–phosphatase networks. Here we used real‐time NMR spectroscopy to study the effect of kinases and phosphatases present in Xenopus oocytes and egg extracts on the phosphorylation state of the “unique domain” of c‐Src. We followed the phosphorylation of S17 in oocytes, and of S17, S69, and S75 in egg extracts by NMR spectroscopy, MS, and western blotting. Addition of specific kinase inhibitors showed that S75 and S69 are phosphorylated by CDKs (cyclin‐dependent kinases) differently from Cdk1. Moreover, although PKA (cAMP‐dependent protein kinase) can phosphorylate S17 in vitro, this was not the major S17 kinase in egg extracts. Changes in PKA activity affected the phosphorylation levels of CDK‐dependent sites, thus suggesting indirect effects of kinase–phosphatase networks. This study provides a proof‐of‐concept of the use of real‐time in vivo NMR spectroscopy to characterize kinase/phosphatase effects on intrinsically disordered regulatory domains.     

Study of sulphur in Assam coals by X-ray photoelectron spectroscopy

X-ray photoelectron spectroscopy (XPS) has been used to study the nature and content of sulphur contained in coal samples from Assam. In each case two sulphur 2p (S 2p) peaks were observed. The 169–171 eV 2p peak corresponds to sulphate, whilst the 164–165 eV peak is assigned to S in iron sulphide compounds such as pyrite, marcasite, etc. and also organic sulphur. The complete absence of a 169–171 eV S peak from a coal sample from which both pyritic and sulphate sulphur were removed by hydrodesulphurization strongly indicates that the remaining 164.7 eV S 2p peak corresponds to the total organic sulphur present in the coal.     

Synthesis of di(4‐hydroxyl benzophenone) sebacate and its usage as initiator in the photocrosslinking of polyethylene

A new benzophenone (BP) derivative with a long carbon chain and two chromophoric groups—di (4‐hydroxyl benzophenone) sebacate (BP‐S) used as a photoinitiator in the photocrosslinking of polyethylene (PE) has been synthesized and characterized by ultraviolet (UV) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and elemental analysis. The kinetic characteristics of BP‐S photoinitiated crosslinking of PE in the melt and its compatibility with PE resin have been examined by gel content measurement and thermal migration experiment. The results show that BP‐S is an excellent photoinitiator, which has better compatibility, less volatility, higher photoinitiating efficiency, and longer storage time than BP itself. It is promising for industrial applications of the photocrosslinking of polyolefins. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1581–1586, 2002;     

Surface and interfacial FTIR spectroscopic studies of latexes. IX. The effect of homopolymer and copolymer structures on surfactant mobility in Sty/BA latices

The effects of homopolymer and copolymer compositions and structures in styrene/n-butyl acrylate (Sty/BA) latices on sodium dioctyl sulfosuccinate (SDOSS) surfactant mobility and its preferential concentration at the film–air (F–A) and film–substrate (F–S) interfaces were examined using attenuated total reflectance Fourier transform infrared (ATR FTIR) spectroscopy. It appears that the SDOSS concentration at the F–S interface is highest when the Sty/BA feed ratio is 50/50, and the excess of Sty results in migration of SDOSS surfactant to the F–A interface. This behavior is attributed to the increased glass transition temperature and diminished compatibility between surfactant molecules and copolymer latex. This study also shows that the primary factors that influence exudation to either F–A or F–S interfaces are surface tension of the substrate, glass transition temperature, water flux during coalescence, and compatibility between latex components. © 1995 John Wiley & Sons, Inc.     

Lasers and Molecular Beams Applied to the Study of Clusters of Chiral Molecules

Resonance-enhanced two-photon ionization time-of-flight spectroscopy has been applied in a supersonic beam to study R-(+)-1-phenyl-1-propanol (P_R) and its diastereomeric clusters with R(–) and S(+) 2-butanol (B_R; B_S) and with R(–) and S(+) 2-butylamine (A_R, A_S). This mass resolved spectroscopy allowed us to assign a few vibronic frequencies of P_R and measure the spectral shift of the diastereomeric clusters P_RB_R, P_RB_S, P_RA_R, and P_RA_S. The different bathocromic shifts observed in the two pairs indicates the possibility for spectroscopically differentiating the aggregates. Moreover, very reproducible differences in the fragmentation patterns provide an additional tool for their discrimination.     

Sol–gel synthesis and characterization of lithium aluminate (L–A–H) and lithium aluminosilicate (L–A–S–H) gels

Hydrous lithium aluminosilicate (L–A–S–H) and lithium aluminate (L–A–H) gels are candidate precursors for glass-ceramics and ceramics with potential advantages over conventional processing routes. However, their structure before calcination remained largely unknown, despite the importance of precursor structure on the properties of the resulting materials. In the present study, it is demonstrated that L–A–S–H and L–A–H gels with Li/Al ≤ 1 can be produced via an organic steric entrapment route, while higher Li/Al ratios lead to crystallization of gibbsite or nordstrandite. The composition and the structure of the gels was studied by thermogravimetric analysis, X-ray diffraction, ²⁷Al and ²⁹Si magic-angle spinning nuclear magnetic resonance, and Raman spectroscopy. Aluminium was found to be almost exclusively in six-fold coordination in both the L–A–H and the L–A–S–H gels. Silicon in the L–A–S–H gels was mainly in Q⁴ sites and to a lesser extent in Q³ sites (four-fold coordination with no Si–O–Al bonds). The results thus indicate that silica-rich and aluminium-rich domains formed in these gels.     

The S?C?O (O?C?S) edward—lemieux effect is controlled by a P-orbital on oxygen. Evidence from electron momentum spectroscopy,photoelectron spectroscopy,X-ray crystallography,and density functional theory

The nature of the lone pairs in the series of molecules methyl propyl sulfide, dimethylthiomethane, methyl thiomethyl ether (MTME), dimethoxy-methane, and methyl propyl ether has been examined experimentally by the techniques of electron momentum spectroscopy and photoelectron spectroscopy. Although the HOMO of MTME is found to be a p-orbital on sulfur, it is the p-orbital on oxygen that controls the Edward—Lemieux effect (the anomeric effect) in this molecule through a combination of both stabilizing and destabilizing interactions with C–S orbitals.     

Synthesis and characterization of styrene-based microbeads possessing amine functionality

Microbeads possessing amine functionality at the surface have been prepared by two methods: In the first method, poly(4-vinylpridine/styrene) P(4VP/S) copolymer microbeads containing 13–69 mol % 4-vinylpridine (4VP) were synthesized from the monomers. In the second method, animated polystyrene (PS) particles were prepared by postpolymerization reactions on cross-linked PS and polychloromethylstyrene particles to obtain poly(aminomethylstyrene/styrene) and polydiethylaminomethylstyrene particles, respectively. Scanning electronic microscopy of P(4VP/S) microbeads showed regular and spherical particles having a diameter between 80 and 200 nm depending on 4VP content. The chemical structure of the various particles made was studied using Fourier transform infrared spectroscopy, electron spectroscopy for chemical analysis (ESCA), and elemental analysis, whereas thermal properties were determined by differential scanning calorimetry and thermogravimetric analysis. © 1994 John Wiley & Sons, Inc.     

Synthesis of a liquid zirconium hybrid resin and the ability of the resin to accelerate the curing of a transparent silicone‐modified cycloaliphatic epoxy nanocomposite

A liquid zirconium hybrid resin (Zr–QR) was synthesized through sol‐gel reactions of zirconium butoxide with silanol‐terminated polydimethylsiloxane (DMS‐S12) and γ‐glycidoxypropyltrimethoxysilane (Z‐6040). The sol‐gel reactions were monitored using Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance spectroscopy. The Zr–QR morphology was investigated using field emission transmission electron microscopy. The Zr–QR had a well‐ordered morphology and the dimensions were less than 5 nm. These properties were achieved because DMS‐S12 was used to separate the zirconium clusters and Z‐6040 was used to stabilize the Zr–QR. The acceleration of the curing reaction between silicone‐modified cycloaliphatic epoxy (SEP) and methylhexahydrophthalic anhydride (MHHPA) caused by the Zr–QR was investigated. Differential scanning calorimetry and FTIR spectroscopy investigations showed that the Zr–QR first reacted with MHHPA, producing chelating ligands and carboxylic acid. Unlike in the conventional method (adding acetic acid to cause non‐reactive chelating ligands to form), the carboxylic acid produced effectively accelerated the curing reaction between the SEP and MHHPA. The chelating ligand produced from the Zr–QR and MHHPA suppressed the gelation of the Zr–QR itself during the nanocomposite (SEP–Zr–QR) curing process. The cured SEP–Zr–QR nanocomposite exhibited excellent optical transmittance at visible wavelengths.© 2015 Society of Chemical Industry     

Deteriorated hardened cement paste structure analyzed by XPS and 29Si NMR techniques

In this report, X-ray photoelectron spectroscopy (XPS) and ²⁹Si-MAS-NMR was used for the evaluation of deteriorated hardened cement pastes. The deterioration by ammonium nitrate solution was accompanied by changes in the pore structure as well as by structural changes in the C–S–H in the hardened cement paste. The CaO/SiO₂ ratio of the C–S–H decreased with the progress of deterioration, there was also polymerization of the silicate in the C–S–H. It was confirmed that the degree of polymerization of silicate of the C–S–H in hardened cement paste can be determined by XPS. It was also shown that the polymerization depends on the structure of the C–S–H.     

Catalytic Pd–Ag nanoparticles immobilized on fiber glass by surface self-propagating thermal synthesis

Pd–Ag nanoparticles with different Pd/Ag ratio were deposited onto fiber glass by using the technique of surface self-propagating thermal synthesis (SSTS) and characterized by X-ray photoelectron spectroscopy (XPS), atomic absorption spectroscopy (ААS), and EXAFS spectroscopy. The samples reduced in hydrogen exhibited the formation of Pd–Ag alloy whose tentative structure and composition were suggested. Thermally scheduled reduction of Pd–Ag catalysts in hydrogen made the Ag atoms partially oxidized. Reported are the catalytic properties of synthesized Pd–Ag samples in selective hydrogenation of acetylene.     

Synthesis and characterization of new 4‐tolyldiphenylamine derivatives for hole transporting polymers

New hole transport polymers have been synthesized by condensation polymerization of 4‐tolyldiphenylamine (TDPA) with various types of aldehyde. The reaction conditions have been investigated to yield polymers with high molecular weight. It is found that the molecular weight and yield of the TDPA–aldehyde polymers strongly depend on the electron donor–acceptor nature of the substituent on the aromatic ring of the aldehyde monomer. Structural characterization by ¹H NMR spectroscopy shows that the addition condensation reaction occurs exclusively at the para position of TDPA. The electrochemical and optical properties of polymers have been investigated by cyclic voltammetry and UV–vis spectroscopy. Cyclic voltammograms of all polymers show well‐defined pairs of reduction and oxidation peaks, indicating that the polymers are electrochemically active. All polymers show low conductivities of magnitude 10^?14 S cm^?1. Differential scanning calori‐metry measurements reveal that TDPA–aldehyde polymers exhibit glass transitions in the range 170–230 °C. These polymers possess good solubility and the films show sufficient morphological stability. © 2001 Society of Chemical Industry     

Gel nanostructure in alkali-activated binders based on slag and fly ash,and effects of accelerated carbonation

Binders formed through alkali-activation of slags and fly ashes, including ‘fly ash geopolymers’, provide appealing properties as binders for low-emissions concrete production. However, the changes in pH and pore solution chemistry induced during accelerated carbonation testing provide unrealistically low predictions of in-service carbonation resistance. The aluminosilicate gel remaining in an alkali-activated slag system after accelerated carbonation is highly polymerised, consistent with a decalcification mechanism, while fly ash-based binders mainly carbonate through precipitation of alkali salts (bicarbonates at elevated CO₂ concentrations, or carbonates under natural exposure) from the pore solution, with little change in the binder gel identifiable by nuclear magnetic resonance spectroscopy. In activated fly ash/slag blends, two distinct gels (C–A–S–H and N–A–S–H) are formed; under accelerated carbonation, the N–A–S–H gel behaves comparably to fly ash-based systems, while the C–A–S–H gel is decalcified similarly to alkali-activated slag. This provides new scope for durability optimisation, and for developing appropriate testing methodologies.     

X-ray photoelectron spectroscopic investigation of coal

X-ray photoelectron spectroscopy (XPS) has been used to study the carbon, oxygen and sulphur content of several coking coals, a series of sink—float fractions from a high-volatile coking coal, and several inorganic minerals that are commonly found in coals. Single carbon and oxygen peaks were obtained that corresponded to carbon 1s orbital and oxygen 1s orbital electron binding energies which are expressed in units of electron volts (eV). Two sulphur 2p (S 2p) peaks were found. The 169–171 eV S 2p peak corresponded to the sulphates resulting from the oxidation of pyrite (FeS₂), while the 163–164 eV S 2p peak was assigned to the iron sulphide compounds such as pyrite or marcasite. No separate organic sulphur peaks were found for coal, because the majority of the organic sulphur peaks are probably overlapped by the inorganic sulphide line at 163–164 eV. The total carbon and sulphur determined using the XPS peak height correlated with the chemical analysis, although the accuracy of the XPS determinations seems to be lower. A possible direct quantitative method for determining the organic sulphur in coal by XPS is discussed.     

The Effect of H2S on the Performance of SOFCs using Methane Containing Fuel

In recent years, the interest for using biogas derived from biomass as fuel in solid oxide fuel cells (SOFCs) has increased. To maximise the biogas to electrical energy output, it is important to study the effects of the main biogas components (CH₄ and CO₂), minor ones and traces (e.g. H₂S) on performance and durability of the SOFC. Single anode‐supported SOFCs with Ni–Yttria‐Stabilised‐Zirconia (YSZ) anodes, YSZ electrolytes and lanthanum‐strontium‐manganite (LSM)–YSZ cathodes have been tested with a CH₄–H₂O–H₂ fuel mixture at open circuit voltage (OCV) and 1 A cm^–2 current load (850 °C). The cell performance was monitored with electric measurements and impedance spectroscopy. At OCV 2–24 ppm H₂S were added to the fuel in 24 h intervals. The reforming activity of the Ni‐containing anode decreased rapidly when H₂S was added to the fuel. This ultimately resulted in a lower production of fuel (H₂ and CO) from CH₄. Applying 1 A cm^–2 current load, a maximum concentration of 7 ppm H₂S was acceptable for a 24 h period.     

Poly[bis(2-aminophenyloxy)disulfide]: A polyaniline derivative containing disulfide bonds as a cathode material for lithium battery

A new conductive polyaniline derivative containing disulfide bonds, poly[bis(2-aminophenyloxy)disulfide] (PAPOD), has been proposed as a high energy-storage material. PAPOD has been synthesized using a moderate oxidant ferric chloride and characterized by elemental analysis, X-ray photoelectron spectroscopy (XPS), FT-IR, FT-Raman, and UV–vis spectroscopy. The cyclic voltammograms of this polymer show that the intramolecular self-catalysis occurs between the conductive main-chain polyaniline (doping/undoping processes of the π-conjugated system) and side-chain disulfide bonds (scission/reformation processes of the S–S bonds) in PAPOD. Because the redox reaction of conductive main-chain polyaniline occurs in the same potential range as that of the side-chain disulfide bonds of this polymer, the Li/PAPOD test cell displays a charge capacity of 230 mAh g⁻¹-cathode and an energy density of 460 mWh g⁻¹-cathode, which is about 2–3 times higher than those of inorganic intercalation compounds.     

Thermal conductivity of SiC microwires: Effect of temperature and structural domain size uncovered by 0 K limit phonon scattering

A comparative study of structure and thermal properties is reported for three 3C crystalline silicon carbide (SiC) microwires, including Sylramic, Hi-Nicalon S and a sample fabricated by laser chemical vapor deposition (LCVD). Structural characterization by Raman spectroscopy and x-ray diffraction (XRD) finds that the LCVD-based sample contains excessive silicon and smallest grains of SiC but detectable free carbon. Thermal characterization from room temperature down to 20 K uncovers the effect of nanosized grain on thermal properties. The thermal properties are correlated with the structure via structural thermal domain (STD) size, defined as the grain boundary-induced phonon mean free path at the 0 K limit. The STD size of the three samples is found as 9.35, 1.42 and 1.03?nm for the Sylramic, Hi-Nicalon S and LCVD SiC fibers, proportional to and nearly one order of magnification smaller than the corresponding crystalline size determined by XRD: 67–113, 14.6–18.4, and 5.85–7.84?nm.     

Recent advances in stratification and film formation of latex films; attenuated total reflection and step-scan photoacoustic FTIR spectroscopic studies

Surfactant–latex molecular level interactions as well as transient effects during latex film formation play an important role in latex technology. This review article focuses on the siloxane effects on anionic sodium dioctylsulfosuccinate (SDOSS) surfactant exudation during latex coalescence and quantitative analysis of SDOSS distribution at the both film–air (F–A) and film–substrate (F–S) interfaces. Attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy was utilized for characterization of the interactions between SDOSS and styrene–butyl acrylate latex copolymers. In addition, studies of SDOSS stratification along with depth-profiling analysis during latex film formation utilizing step-scan photoacoustic (S²-PAS) FTIR spectroscopy illustrate that SDOSS content is enriched at the F–A interface and decreases as the penetration depth increases across the latex film thickness. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 1321–1348, 1998     

Metal Complexes of a Novel Terpolymer Ligand: Synthesis, Spectral, Morphology, Thermal Degradation Kinetics and Antimicrobial Screening

2-amino-6-nitro-benzothiazole and thiosemicarbazide with formaldehyde (BTF) terpolymer ligand and its metal complexes have been synthesized. The plausible structure of the synthesized BTF terpolymer ligand was elucidated on the basis of elemental analysis and spectral studies such as FTIR, UV-Vis, ¹H and ¹³C NMR spectroscopy. Gel permeation chromatography (GPC) was used to determine the molecular weight of the terpolymer. The terpolymer metal complexes were analyzed by elemental analysis, molar conductivity measurements, and magnetic susceptibilities. The structure and geometry of the metal complexes were confirmed by various spectral techniques viz. electronic, ESR, FTIR and NMR spectroscopy. The morphology of the BTF terpolymer ligand and its metal complexes was examined using scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The thermal decomposition behaviour of the terpolymer ligand and its complexes was determined using thermogravimetric analysis (TGA). Freeman–Carroll (FC), Sharp–Wentworth (SW) and Phadnis–Deshpande (PD) methods were used to calculate the thermal activation energy (E_a), order of reaction (n), entropy change (ΔS), free energy change (ΔF), apparent entropy (S*) and frequency factor (Z) from the TGA data. Phadnis–Deshpande method was also used to propose the thermal degradation model for the decomposition pattern of the terpolymer ligand. The terpolymer ligand and its metal complexes were screened for its antimicrobial activity against chosen microbes.     

Characterization and Electrical Properties of Some Hydrochloric Acid-Doped Aniline and 2-Amino-Pyridine Homopolymers and Copolymers

The synthesis of (group I) hydrochloric acid-doped poly(aniline-co-toluidine), poly(aniline-co-thiophene), poly(aniline-co-o-phenylenediamine), and poly(aniline-co-2-aminopyridine) as well as their hydrochloric acid-doped homopolymers of polyaniline, poly-m-toluidine, poly-o-phenylene diamine, and poly-2-aminopyridine and the synthesis of (group II) hydrochloric acid-doped poly (2-aminopyridine-co-o-phenylene diamine) and its hydrochloric acid-doped homopolymers of poly 2-amino pyridine and poly-o-phenylene diamine have been carried out via a chemical oxidation process using ammonium and potassium persulphate as chemical initiators. The synthesized homo- and copolymers were characterized by ultraviolet-visible spectroscopy (UV-VIS), infrared spectroscopy (IR), and thermal analysis. The variation of the electrical conductivity (σ, S cm^?1) with the reciprocal of the absolute temperature (1000/T, K) at different frequencies (1–1000 kHz) for hydrochloric acid homopolymers and copolymers is illustrated.