Interactions of colloidal particles with complex ions and polymers

The lecture represented a review of the work done in the author’s laboratory dealing with the behavior of a variety of submicronic particles in the presence of simple and complex ions, surface active agents, polyelectrolytes and polymers. Experimentally, the stability of colloidal sols, which can be readily followed by optical methods, was investigated as a function of the composition of the electrolyte environments. This approach offers a number of advantages when the evaluation of solid-solute interactions is attempted. By selecting various colloidal sols one can study the interactions of counterions with particles of different surface properties, such as the charge density, type and concentration of stabilizing ions, degree of solvation, surface ionization, etc. One of five papers presented at the Symposium, “Basic Aspects of Detergency,” AOCS-ISF World Congress, Chicago, September 1970. This lecture summary was prepared during the author’s stay at the Swedish Institute for Surface Chemistry, Stockholm.     

Stickstoffbindung in Soda- und Hochofenschlacken

Stand der Erkenntnisse über die Entstickung von Roheisen durch Soda und die Stickstoffbindung in Schlacke. Analytisch-chemischer Versuchsplan. Untersuchung von Betriebsschlacken und entsprechenden synthetischen Schmelzen sowie Aufstellung einer Stickstoffbilanz der Sodabehandlung von Thomasroheisen. Deutung der Entstickung bei der Sodabehandlung. Hinweise auf die Stickstoffbewegung im Hochofen.     

2,5-Dihydroxybenzoic acid butylamine and other ionic liquid matrixes for enhanced MALDI-MS analysis of biomolecules

The performance of the new ionic liquid MALDI-MS matrix 2,5-dihydroxybenzoic acid butylamine (DHBB) was assessed and compared to results obtained with the ionic liquid MALDI-MS matrixes alpha-cyano-4-hydroxycinnamic acid butylamine (CHCAB), 3,5-dimethoxycinnamic acid triethylamine (SinTri), and the frequently used solid MALDI matrixes 2,5-dihydroxybenzoic acid (DHB) and alpha-cyano-4-hydroxycinnamic acid (CHCA). The vacuum-stable, liquid consistency of ionic liquid matrix sample preparations considerably enhanced MALDI-MS analysis in terms of shot-to-shot reproducibility. Consequently, relative standard deviations serving as a measure for reproducibility of intensity-values acquired from 90 different spots on one MALDI-MS preparation were approximately one-half as high when solid DHB was replaced by the ionic liquid DHBB and eight times lower after exchange of solid CHCA by ionic liquid CHCAB. Interestingly, the ionic liquid MALDI matrix DHBB conserved the broad applicability of its solid analogue DHB, reduced MALDI induced fragmentation of monosialylated glycans and gangliosides, and was the superior ionic liquid matrix for MALDI-MS analysis of oligosaccharides and polymers, such as poly(ethylene glycol). It also worked well with glycoconjugates, peptides, and proteins; however, the tendency of DHBB to form multiple alkali adduct ions with peptides and proteins made CHCAB the ionic liquid matrix of choice for peptides. SinTri was the best ionic liquid matrix for proteins of high molecular weight, such as IgG. Furthermore, it was demonstrated for the first time that solvent properties and MALDI matrix properties of ionic liquids, such as DHBB, can be combined to enable fast, direct screening of an enzymatic reaction. This was proven by the desialylation of sialylactose with sialidase from Clostridium perfringens in the presence of diluted aqueous DHBB and subsequent direct MALDI-MS analysis of the reaction mixture.     

Thermofraktographie zur Schnellanalyse von Kunststoffen. 4. Mitt.: Identifizierung der Basiskomponenten von Epoxidharzen

Thermofractography is suitable for the rapid identification of the basic components of epoxy resins. 2–3 mg of the polymer sample are being heated in the temperature gradient of 200 to 450°C. The thus forming decomposition products are being transferred as a starting line onto the separating thin layer by means of a carrier gas. After development the thermofractogram (TFG) shows in the temperature range of 200 to approx. 350°C the free oligomeres. The resulting phenols and their subsequent products appear on the TFG from 350°C. A cycloaliphatic type does not give phenolic fragments. The degradation mechanisms of epoxy resins are being discussed in regard to the TFG results and are being confirmed by establishing TGA curves. For the rapid evaluation of the thermofractograms of epoxy resins a questioning scheme is given as an evaluation key.     

Growth parameters and meat quality of finishing hogs supplemented with creatine monohydrate and a high glycemic carbohydrate for the last 30 days of production

The objective of this study was to evaluate the growth and meat quality of hogs supplemented with creatine monohydrate (CMH) and (or) a simple carbohydrate (dextrose) for the last 30 days of production. Crossbred market barrows (n=32; 75 kg) were blocked by weight and randomly allotted to one of eight pens with four animals per pen. Dietary treatments were a control (normal corn and soybean meal diet), CMH (control diet supplemented with 0.55% CMH), DEXT (control diet supplemented with 2.1% dextrose), and COMBO (control diet supplemented with CMH and DEXT). Average daily gain on test, fat depth, hot carcass weight, and LMA (postmortem dot grid measurement) were not affected by dietary treatment. However, a nonsignificant trend (P=0.07) was observed for 10th rib loin muscle area (LMA) gain on test as determined by real-time ultrasound comparisons over the course of the 30 days feeding duration (COMBO=4.24 cm(2) increase vs. control=1.0 cm(2) increase). No significant differences in pork quality were noted across treatment groups.     

Cells of the yeast Saccharomyces cerevisiae are transformable by DNA under non-artificial conditions

Transformants of bakers' yeast (Saccharomyces cerevisiae) can be generated when non-growing cells metabolize sugars (without additional nutrients) in the presence of plasmid DNA. These results suggest that there is a mechanism by which DNA can naturally be taken up by the yeast cell. Natural transformation does not take place in common complete or minimal yeast culture media such as YPD and YNB. The starvation conditions used in our experiments thus seem to be an important prerequisite for such transformation events.