Search results for "wt"

Polymerization of methyl and phenyl oxazoline initiated with alkyl chloroformates

2010

It has been shown that alkyl chloroformates are capable of initiating the polymerization of oxazolines. Esters itself initiate rather slowly and the polymerization proceeds via covalent growing species. Exchange of counter ions with triflate or iodide anions leads to faster initiation and higher reaction rates. The polymerization is of living character.

Neuroprotective, antioxidant and antiproliferative activity of grapefruit IntegroPectin on SH-SY5Y cells

2021

AbstractTested in vitro on SH-SY5Y neuroblastoma cells, grapefruit IntegroPectin is a powerful neuroprotective, antioxidant and antiproliferative agent. The strong antioxidant properties of grapefruit IntegroPectin, and its ability to preserve mitochondrial membrane potential and morphology, severely impaired in neurodegenerative disorders, make this new biopolymer highly soluble in water an attractive therapeutic agent for oxidative stress-associated brain disorders. Similarly, the ability of this new citrus pectin rich in naringin, linalool, linalool oxide and limonene adsorbed at the outer surface to inhibit cell proliferation or even kill, at high doses, neoplastic cells, coupled to its…

The Number of Active Sites for the Polymerization of Ethylene, Propylene and Butene-1 by Ziegler-Natta Catalyst

1975

Virazole (Ribavirin) a Cytostatic Agent

1978

Virazole (1-β-D-ribofuranosyl-1,2,4-triazole-3carboxamide,ribavirin) is a synthetic triazol nucleoside with a broad spectrum of antiviral activity. But virazole affects the metabolism not only of virus infected cells. Virazole strongly inhibits the cell proliferation of mouse lymphoma cells (L 5178y), which were not infected with DNA- or RNA-viruses. Starting with 3 × 103 cells/ml and an incubation period of 72 hr, the drug reduces the cell proliferation to 50% (= ED50 concentration) in a concentration of 4,7 μM.

Synthesis of Macromolecular Substances by Condensation Polymerization and Stepwise Addition Polymerization

2001

Condensation polymerizations (polycondensations) are stepwise reactions between bifunctional or polyfunctional components, with elimination of simple molecules such as water or alcohol and the formation of macromolecular substances. For the preparation of linear condensation polymers from bifunctional compounds (the same considerations apply to polyfunctional compounds which then lead to branched or crosslinked condensation polymers) there are basically two possibilities. One either starts from a monomer which has two unlike groups suitable for polycondensation (AB type), or one starts from two different monomers, each possessing a pair of identical reactive groups that can react with each …

1977

The solution polymerization of styrene in methylene dichloride catalysed by trifluoromethanesulfonic acid takes place at a high rate even at low catalyst concentration. The S-shaped course of the conversion curves is explained by a reaction mechanism, in which the catalyst rapidly forms an inactive complex with one monomer molecule, and this monomer-acid complex is in equilibrium with the free catalyst molecule from which the propagating species are formed. Therefore, the formation of active initiating species becomes a slow process which depends also on the change of monomer concentration during polymerization. It is assumed that the active initiating species are formed from two or three m…

ChemInform Abstract: Synthesis and Antiproliferative Activity of Novel 3-(Indazol-3-yl)-quinazolin-4(3H)-one and 3-(Indazol-3-yl)-benzotriazin-4(3H)-…

2010

Several new 3-(indazol-3-yl)-quinazolin-4(3H)-one and 3-(indazol-3-yl)-benzotriazin-4(3H)-one derivatives 5 and 6 were synthesized and tested for their in vitro antiproliferative activity against Raji, K562, and K562-R cell lines. The pharmacological screening showed that some 2, 6, or 7-substituted quinazolinones 5 posses a significant antiproliferative activity, with a percentage growth inhibition ranging from 44.8% to 100% at 50 microM, which was higher than that showed by the unsubstituted derivative 5a previously synthesized. For the most active compounds 5d, 5f, and 5g the IC50 were recorded.

General Cytotoxicity Assessment by Means of the MTT Assay

2014

Cytotoxicity assays were among the first in vitro bioassay methods used to predict toxicity of substances to various tissues. In vitro cytotoxicity testing provides a crucial means for safety assessment and screening, and for ranking compounds. The choice of using a particular cytotoxicity assay technology may be influenced by specific research goals. As such, four main classes of assays are used to monitor the response of cultured cells after treatment with potential toxicants. These methods measure viability, cell membrane integrity, cell proliferation, and metabolic activity. In this chapter, we focus on the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium reducti…

Data from: Effects of food abundance and early clutch predation on reproductive timing in a high Arctic shorebird exposed to advancements in arthropo…

2017

Climate change may influence the phenology of organisms unequally across trophic levels and thus lead to phenological mismatches between predators and prey. In cases where prey availability peaks before reproducing predators reach maximal prey demand, any negative fitness consequences would selectively favor resynchronization by earlier starts of the reproductive activities of the predators. At a study site in northeast Greenland, over a period of 17 years, the median emergence of the invertebrate prey of Sanderling Calidris alba advanced with 1.27 days per year. Yet, over the same period Sanderling did not advance hatching date. Thus, Sanderlings increasingly hatched after their prey was m…

The influence of the out-of-family care institutions onto child’s development

2013

The article offers the analysis of the out-of-family care institutions and their influence on child’s development. Despite the fact that the institutional out-of-family care provides the subject with physical security and satisfies his basic needs it cannot provide the most important aspect of the development of the child - the close relationship with at least of one of the adults who would be able to captivate and become a legal guardian for several years.