Search results for "Reaction"

Do Individual Reactions Predict Group Reactions?

1987

Summary.-Group reactions of three-man groups included in 71 junior ice hockey players were measured using a homeostat. Individual reaction times (simple reaction time, choice reaction time) did not predict group performance. In social psychology many studies have compared the effectiveness of an individual and a group (Kelley & Thibaut. 1969). Less research has been done to predict group performance by individuals' performance. In this study group performance was measured by a homeostat developed in the USSR (Medvedev, 1967). Ic consists of three microammeters connected in the same electric network. When the Examiner rotates the electric resistance, the subjects ought to restore the equilib…

The molecular profiling of solid tumors by liquid biopsy: a position paper of the AIOM–SIAPEC-IAP–SIBioC–SIC–SIF Italian Scientific Societies

2021

The term liquid biopsy (LB) refers to the use of various biological fluids as a surrogate for neoplastic tissue to achieve information for diagnostic, prognostic and predictive purposes. In the current clinical practice, LB is used for the identification of driver mutations in circulating tumor DNA derived from both tumor tissue and circulating neoplastic cells. As suggested by a growing body of evidence, however, there are several clinical settings where biological samples other than tissue could be used in the routine practice to identify potentially predictive biomarkers of either response or resistance to targeted treatments. New applications are emerging as useful clinical tools, and o…

Sampling strategy in molecular microbial ecology: influence of soil sample size on DNA fingerprinting analysis of fungal and bacterial communities.

2003

Assessing soil microbial community structure by the use of molecular techniques requires a satisfactory sampling strategy that takes into account the high microbial diversity and the heterogeneous distribution of microorganisms in the soil matrix. The influence of the sample size of three different soil types (sand, silt and clay soils) on the DNA yield and analysis of bacterial and fungal community structure were investigated. Six sample sizes from 0.125 g to 4 g were evaluated. The genetic community structure was assessed by automated ribosomal intergenic spacer analysis (A-RISA fingerprint). Variations between bacterial (B-ARISA) and fungal (F-ARISA) community structure were quantified b…

Dioxidomolybdenum(VI) and -tungsten(VI) complexes with tripodal amino bisphenolate ligands as epoxidation and oxo-transfer catalysts

2017

The molybdenum(VI) and tungsten(VI) complexes [MO2(L)] (M = Mo (1), W (2), H2L = bis(2-hydroxy-3,5-di-tert-butybenzyl)morpholinylethylamine) were synthesized and the complexes were used to catalyze oxotransfer reactions, viz. sulfoxidation, epoxidation and benzoin oxidation. For comparison, the same reactions were catalyzed using the known complexes [MO2(L′)] (M = Mo (3), W (4), H2L′ = bis(2-hydroxy-3,5-di-tert-butybenzyl)ethanolamine) and [MO2(L″)] (M = Mo (5), W (6), H2L″ = bis(2-hydroxy-3,5-di-tert-butybenzyl)diethyleneglycolamine). The oxo atom transfer activity between DMSO and benzoin at 120 °C was identical for all studied catalysts. Reasonable catalytic activity was observed for sul…

A statistical design of experiments for optimizing the MALDI-TOF-MS sample preparation of polymers. An application in the assessment of the thermo-me…

2011

[EN] The sample preparation procedure for MALDI-TOF MS of polymers is addressed in this study by the application of a statistical Design of Experiments (DoE). Industrial poly (ethylene terephthalate) (PET) was chosen as model polymer. Different experimental settings (levels) for matrixes, analyte/matrix proportions and concentrations of cationization agent were considered. The quality parameters used for the analysis were signal-to-noise ratio and resolution. A closer inspection of the statistical results provided the study not only with the best combination of factors for the MALDI sample preparation, but also with a better understanding of the influence of the different factors, individua…

Über die Elementarreaktionen der radikalischen Polymerisation von Benzylmethacrylat

1973

Durch Kombination stationarer und instationarer Methodik (rotierender Sektor) werden die Absolutwerte der Geschwindigkeitskonstanten von Kettenwachstum und Kettenabbruch von Benzylmethacrylat unter dem Einflus verschieden viskoser Losungsmittel bestimmt. Die Radikalausbeute f hangt von der Viskositat des Losungssystems und der Art der Monomeren, dagegen nicht (oder fast nicht) von der Konzentration des Monomeren und der Geschwindigkeit der Radikalerzeugung ab. Daraus wird geschlossen, das ein merklicher Anteil von Zwillingsrekombinationen auserhalb des primaren Losungsmittelkafigs stattfindet. Die Geschwindigkeitskonstante kw des Kettenwachstums stimmt praktisch uberein mit der des Methylme…

Studien zum Vorgang der Wasserstoffübertragung, 38. Selektive katalytische Hydrierungen mit Palladium-Trägerkatalysatoren auf der Basis von ‘Aminoaer…

1976

Es wird die Darstellung neuer Palladium-Trager-Katalysatoren auf modifizierten Siliciumdioxidtragern insbesondere ‘Aminoaerosil’ beschrieben. Die Oberflachenaminogruppen der Palladium-Trager-Katalysatoren bewirken durch Salzbildung eine bevorzugte katalytische Hydrierung von Olefincarbonsauren in Gegenwart ihrer Athylester. Durch Variation der Struktur der Substrate, des Palladiumgehalts und der Reduktionsweise des Katalysators, der chemischen Veranderung der Oberflachengruppe des Tragers sowie des Losungsmittels, wird versucht, Einblick in die Vorgange an der Kontaktoberflache zu gewinnen. Studies on the Occurrence of Hydrogen Transfer, 38. — Selective Catalytic Hydrogenations with Palladi…

ChemInform Abstract: Photochemical Functionalization of Allyl Benzoates by C-H Insertion.

2013

The photoreactivity of allyl benzoates, containing an electron-rich double bond, has been explored by irradiation at 305 nm in different solvents. Solvent addition products arising from an insertion of the alpha H–C bonds of THF, dioxane, and i-PrOH to the allylic double bond was realized. The observed reactivity depended on reaction conditions and substitution pattern of the substrate. A DFT study on this unusual reaction was performed allowing the formulation of two mechanistic pathways.

The kinetics of anionic polymerization of styrene in 1,2-dimethoxiethane

2007

Kinetic measurements in a flow apparatus in combination with conductance measurements, permit the determination of the two equilibrium constants Kes and Kdiss* and the three propagation rate constants k(±)c, k(±)s and k(−) as a function of temperature. The great differences in the polymerization rate in various solvents are mainly caused by their influence on the equilibrium constants. The influence of the solvent on the rate constants is not greater than in other chemical reactions.

1972

The metathesis reaction of cyclooctene was investigated with respect to the solvent, the catalyst, and the ratio of its components. A necessary condition for an active metathesis catalyst appears to be the presence of two transition metal-carbon bonds in a complex of the transition metal compound with an aluminum halide. A structure for the active complex is proposed. Die Metathese-Reaktion von Cycloocten wurde unter dem Einflus verschiedener Losungsmittel, verschiedener Katalysatorsysteme und Verhaltnisse der Katalysatorkomponenten untersucht. Die Ergebnisse lassen darauf schliesen, das die aktiven Katalysatoren Komplexe besonderer Ubergangsmetallverbindungen mit Aluminiumhalogeniden darst…