Interaction Of Oxygen With Zn(0001) Surface

EELS and XPS studies show the presence of both adsorbed atomic and molecular oxygen at low temperatures. The nature of the oxide layer formed on the surface has been characterized by angular dependent and variable temperature EELS. A loss peak around 550 cm−1 is assigned to an electronic transition.

Hydroxylation of oxygen-covered Cu(110) and Zn(0001) surfaces by interaction with CH3OH, (CH3)2NH, H2S, HCl and other proton donor molecules

EELS studies provide definitive evidence for the hydroxylation of oxygen-covered Cu(110) and Zn(0001) surfaces on interaction with proton donor molecules such as H2O, CH3OH, HCOOH, NH3 and (CH3)2NH. The occurrence of surface hydroxylation is unambigouusly shown by a study of the interaction of H2S and HCl with an oxygen covered Cu(110) surface.

An NMR study of the interaction of cytosine arabinoside and lysozyme

Abstract is not available.

Singlet and triplet molecular interaction in excimers

A perturbative approach is developed to determine, term by term, the contributions of the various forces to the excimer potentials of the singlet and triplet excimers. The results show that the singlet excimer of naphthalene is more stable than the corresponding triplet excimer primarily due to large contributions of the exciton-resonance and the dispersion energy terms. The variation of the various terms with the conformations of the excimers suggests that the singlet and triplet excimers of naphthalene cannot have identical structure.

Loci affecting gamma-glutamyl transferase in adults and adolescents show age x SNP interaction and cardiometabolic disease associations

Serum gamma-glutamyl transferase (GGT) activity is a marker of liver disease which is also prospectively associated with the risk of all-cause mortality, cardiovascular disease, type 2 diabetes and cancers. We have discovered novel loci affecting GGT in a genome-wide association study (rs1497406 in an intergenic region of chromosome 1, P = 3.9 x 10(-8); rs944002 in C14orf73 on chromosome 14, P = 4.7 x 10(-13); rs340005 in RORA on chromosome 15, P = 2.4 x 10(-8)), and a highly significant heterogeneity between adult and adolescent results at the GGT1 locus on chromosome 22 (maximum P(HET) = 5.6 x 10(-12) at rs6519520). Pathway analysis of significant and suggestive single-nucleotide polymorphism associations showed significant overlap between genes affecting GGT and those affecting common metabolic and inflammatory diseases, and identified the hepatic nuclear factor (HNF) family as controllers of a network of genes affecting GGT. Our results reinforce the disease associations of GGT and demonstrate that control by the GGT1 locus varies with age.

Quantifying surfactant interaction effects on soil moisture

Quantifying surfactant interaction effects on soil moisture and turf quality.

Interaction of Alpha-tocopherol with diphenylpicryl hydrazyl a means to determine the polarity of the environment around Alpha-tocopherol and its binding with lipids

Alpha-Tocopherol is found to interact with the stable free radical DPPH orders of magnitude faster than ordinary phenols. It is suggested that the high reactivity arises from the coplanarity of the C-O-C framework with the aromatic ring. The rate constant of the reaction of Alpha-tocopherol with DPPH increases progressively with solvent polarity and can be quantitatively related to Kosower's Z parameter. Fatty acid derivatives slow down the reaction with DPPH due to binding with Alpha-tocopherol.

Kinetic mechanism of the interaction of D-cycloserine with serine hydroxymethyltransferase

The kinetic mechanism for the interaction of D-cycloserine with serine hydroxymethyltransferase (EC2.1.2.1) from sheep liver was established by measuring changes in the activity, absorbance, and circular dichoism (CD) of the enzyme. The irreversible inhibition of the enzyme was characterized by three detectable steps: an initial rapid step followed by two successive steps with rate constants of 5.4 X s-l and 1.4 X lo4 s-l. The first step was distinguished by a rapid disappearance of the enzyme absorbance peak at 425 nm, a decrease in the enzyme activity to 25% of the uninhibited velocity, and a lowering of the CD intensity at 432 nm to about 65% of the original value. The second step of the interaction was accompanied by a complete loss of enzyme.

Use of a volatile buffer at ambient temperature *1: Versatile approach to the purification of self-complementary synthetic deoxyoligonucleotides by reversed-phase high-performance liquid chromatography

Abstract is not available.

Thermodynamic and kinetic studies on saccharide binding to soya-bean agglutinin.

The fluorescence of N-dansylgalactosamine [N-(5-dimethylaminonaphthalene-1-sulphonyl)galactosamine] was enhanced 11-fold with a 25 nm blue-shift in the emission maximum upon binding to soya-bean agglutinin (SBA). This change was used to determine the association constants and thermodynamic parameters for this interaction. The association constant of 1.51 X 10(6) M-1 at 20 degrees C indicated a very strong binding, which is mainly due to a relatively small entropy value, as revealed by the thermodynamic parameters: delta G = -34.7 kJ X mol-1, delta H = -37.9 kJ X mol-1 and delta S = -10.9 J X mol-1 X K-1. The specific binding of this sugar to SBA shows that the lectin can accommodate a large hydrophobic substituent on the C-2 of galactose. Binding of non-fluorescent ligands, studied by monitoring the fluorescence changes when they are added to a mixture of SBA and N-dansylgalactosamine, indicates that a hydrophobic substituent at the anomeric position increases the affinity of the interaction. The C-6 hydroxy group also stabilizes the binding considerably. Kinetics of binding of N-dansylgalactosamine to SBA studied by stopped-flow spectrofluorimetry are consistent with a single-step mechanism and yielded k+1 = 2.4 X 10(5) M-1 X s-1 and k-1 = 0.2 s-1 at 20 degrees C. The activation parameters indicate an enthalpicly controlled association process.

Replication of the association of common rs9939609 variant of FTO with increased BMI in an Australian adult twin population but no evidence for gene by environment (G x E) interaction

OBJECTIVE: To further investigate a common variant (rs9939609) in the fat mass- and obesity-associated gene (FTO), which recent genome-wide association studies have shown to be associated with body mass index (BMI) and obesity. DESIGN: We examined the effect of this FTO variant on BMI in 3353 Australian adult male and female twins. RESULTS: The minor A allele of rs9939609 was associated with an increased BMI (P=0.0007). Each additional copy of the A allele was associated with a mean BMI increase of approximately 1.04 kg/m(2) (approximately 3.71 kg). Using variance components decomposition, we estimate that this single-nucleotide polymorphism accounts for approximately 3% of the genetic variance in BMI in our sample (approximately 2% of the total variance). By comparing intrapair variances of monozygotic twins of different genotypes we were able to perform a direct test of gene by environment (G x E) interaction in both sexes and gene by parity (G x P) interaction in women, but no evidence was found for either. CONCLUSIONS: In addition to supporting earlier findings that the rs9939609 variant in the FTO gene is associated with an increased BMI, our results indicate that the associated genetic effect does not interact with environment or parity.

Binding of polyphenols to plant cell wall analogues - Part 1: Anthocyanins

Anthocyanins are located within the vacuole of plant cells, and are released following cell rupture during eating or processing at which time they first come into contact with the plant cell wall. The extent of anthocyanin-cell wall interaction was investigated by monitoring the rate of anthocyanin depletion in the presence of pure cellulose or cellulose-pectin composites as cell wall models. It was found that anthocyanins interact with both cellulose and pectin over a two-stage process with initially (mins-hours) 13 similar to 18% of anthocyanins binding to cellulose or cellulose/pectincomposites. With prolonged exposure (days-weeks), a gradual increase in anthocyanin binding occurs, possibly due to anthocyanins stacking on top of a base layer. Binding of acylated and non-acylated anthocyanins followed a similar pattern with slightly more (5-10%) binding of the acylated forms. Composites with the highest pectin content had the greatest anthocyanin binding suggesting the existence of both ionic interactions (with pectin) and hydrophobic interactions (with cellulose) of anthocyanin with plant cell walls.