Improved staining of proteins in polyacrylamide gels including isoelectric focusing gels with clear background at nanogram sensitivity using Coomassie Brilliant Blue G-250 and R-250

An improved procedure for staining of proteins following separation in polyacrylamide gels is described which utilizes the colloidal properties of Coomassie Brilliant Blue G-250 and R-250. The new method is based on addition of 20% v/v methanol and higher concentrations of ammonium sulfate to the staining solution previously described. The method combines the advantage of much shorter staining time with high sensitivity, a clear background not requiring destaining, stepwise staining, and stable fixation after staining. The method has been applied to staining of polyacrylamide gels after sodium dodecyl sulfate-electrophoresis and isoelectric focusing in carrier ampholyte-generated pH gradients.     

Sorption of tributyltin onto a natural quartz sand

The aim of this study is to understand the sorption of tributyltin (TBT) onto natural quartz sand by classical batch experiments and spectroscopic surface analyses. At pH<6, the major species of TBT is the cation TBT(+). Due to the presence of both the cationic part and the butyl chains, TBT should present amphiphilic properties. For concentrations lower than 40 microM, TBT sorption occurs as a homovalent 1:1 cation exchange between either H(+) or Na(+) and TBT(+). The increasing affinity of TBT with respect to the different materials follows the series kaolinite相似文献   

Dihydroanthracenone metabolites from the endophytic fungus Diaporthe melonis isolated from Annona squamosa

Chemical investigation of the endophytic fungus Diaporthe melonis, isolated from Annona squamosa, yielded two new dihydroanthracenone atropodiastereomers, diaporthemins A (1) and B (2), together with the known flavomannin-6,6′-di-O-methyl ether (3). The structures of the new compounds were established on the basis of extensive 1D and 2D NMR spectroscopy, as well as by high resolution mass spectrometry and by CD spectroscopy. Compounds 1–3 were tested for their antimicrobial activity against a multi-resistant clinical isolate of Staphylococcus aureus 25697, a susceptible reference strain of S. aureus ATCC 29213 and against Streptococcus pneumoniae ATCC 49619. Compound 3 strongly inhibited S. pneumonia growth with a MIC value of 2 μg/mL, and showed moderate activity against the S. aureus multi-resistant clinical isolate and susceptible reference strain (MIC 32 μg/mL), whereas 1 and 2 were not active against the tested strains.     

CI Reactive Black 5 dye as a visible crosslinker to improve physical properties of lyocell fabrics

Bi-functional reactive dyes have been used for reducing the fibrillation of lyocell fibres. The sole influence of CI Reactive Black 5 dye on the fibrillation tendency of lyocell single jersey knitted fabrics was investigated by dyeing with different concentrations (35 g/L for medium shade and 70 g/L for dark shade), dyeing without dyestuff and by decolouration process after each dyeing. The fibrillation tendency of lyocell fibres was accessed by means of fibre wet abrasion resistance and fibrillation number. Nitrogen content was used as indication of the amount of reactive dye in fabrics during dyeing and decolouration processes. The correlation between fibre fibrillation tendency and colour values of fabrics was found. Due to the fibrillation reduction, pilling formation in dyed lyocell fabrics was improved. As colour values can estimate the dye fixation and reduction in fabrics, reactive dye can be used as a visible marker for crosslinking effect on lyocell fabrics.     

Unusual octalactones from Corynespora cassiicola, an endophyte of Laguncularia racemosa

Chemical investigation of the EtOAc extract of the mangrove-derived endophyte Corynespora cassiicola, isolated from Laguncularia racemosa (Combretaceae), afforded five new secondary metabolites, named coryoctalactones A–E (1–5). The structures of the new compounds were determined on the basis of 1D- and 2D-NMR spectroscopy as well as high-resolution mass spectrometry. The absolute configuration of the side chain in 1–3 and 5 were tentatively deduced based on biogenetic consideration in comparison with xestodecalactones, previously isolated from C. cassiicola. All isolated compounds were evaluated for their antimicrobial, cytotoxic, and antitrypanosomal activities.     

Canonical factorization of continuous functions on the -torus

In this article we study the canonical factorization of continuous complex-valued functions on the -dimensional torus belonging to a weighted Wiener algebra with respect to a linear order on the -tuples of integers. It is proved that a function has a canonical factorization in this algebra if and only if it has a logarithm belonging to this algebra. A second characterization is given in terms of winding numbers. Moreover, the maximal ideal spaces of the relevant Banach algebras are identified.

     

Coadsorption de l'oxygène et du monoxyde de carbone sur des surfaces de rhénium

Temperature programmed desorption ($\text{2.65}\text{K}\text{sec}$) has been used to study carbon monoxide and mixed layers of carbon monoxide and oxygen on rhenium ribbons, strongly oriented parallel to the (0001) plane. Four binding states, populated in decreasing energy have been detected. Interpretation of the results on β states agrees qualitatively with King's model postulating dissociation of carbon monoxide molecules and a repulsive interaction energy between carbon and oxygen atoms. However, in the coadsorbed layers studies, it is shown that all the oxygen atoms do not play a part in the recombination process, during desorption, and that when oxygen is adsorbed after carbon monoxide, a displacement reaction occurs, due to apparent transfer from β states towards molecular α states. Optimization of the results on pure carbon monoxide layers leads to an interactional energy ω, equal to 3 $\text{kcal}\text{mole}$, and is only possible if is assumed that β states are formed on alternatively filled and empty rows.     

Discrete non-local boundary conditions for split-step Padé approximations of the one-way Helmholtz equation

This paper deals with the efficient numerical solution of the two-dimensional one-way Helmholtz equation posed on an unbounded domain. In this case, one has to introduce artificial boundary conditions to confine the computational domain. The main topic of this work is the construction of the so-called discrete transparent boundary conditions for state-of-the-art parabolic equation methods, namely a split-step discretization of the high-order parabolic approximation and the split-step Padé algorithm of Collins. Finally, several numerical examples arising in optics and underwater acoustics illustrate the efficiency and accuracy of our approach.     

Factorization in Weighted Wiener Matrix Algebras on Linearly Ordered Abelian Groups

Factorizations of Wiener-Hopf type of elements of weighted Wiener algebras of continuous matrix-valued functions on a compact abelian group are studied. The factorizations are with respect to a fixed linear order in the character group (considered with the discrete topology). Among other results, it is proved that if a matrix function has a canonical factorization in one such matrix Wiener algebra then it belongs to the connected component of the identity of the group of invertible elements in the algebra, and moreover, the factors of the canonical factorization depend continuously on the matrix function. In the scalar case, complete characterizations of canonical and noncanonical factorability are given in terms of abstract winding numbers. Wiener-Hopf equivalence of matrix functions with elements in weighted Wiener algebras is also discussed. The second author is supported by COFIN grant 2004015437 and by INdAM; the third and the fourth authors are partially supported by NSF grant DMS-0456625; the third author is also partially supported by the Faculty Research Assignment from the College of William and Mary.