Search results for "Lene"
showing 10 items of 4480 documents
Synthesis of oxide-supported vanadium catalysts and their activity in ethylene polymerization
1999
The activity of oxide-supported vanadium-based catalyst systems (VOCl 3/Et 2AlCl) in low-pressure ethylene polymerization and the properties of the resulting polyethylenes were studied in relation to the type and mode of modification of the oxide support. Alumina, silica and an un"conventional silica-type material prepared by the sol-gel process were used as supports. Results are compared with those obtained earlier with a catalyst supported on MgCl 2(THF) 2. Of the oxides studied, the silica-type sol-gel material dehydrated and subsequently modified with Et 2AlCl proved to be the best carrier for a vanadium catalyst. The polyethylene prepared by using this catalyst support was found to exh…
In Vitro Evaluation of Poly(lactide-co-glycolide) In Situ Forming Gels for Bedaquiline Fumarate Salt and Pharmacokinetics Following Subcutaneous Inje…
2021
This study evaluated in vitro and in vivo drug release of bedaquiline from in situ forming gels (ISGs) containing 200 mg eq./g bedaquiline fumarate salt prepared with four different grades of poly(d,l-lactide) (PDLLA) or poly(d,l-lactide-co-glycolide) (PLGA) with a lactide/glycolide ratio of 50/50 or 75/25 and acid (A) or ester (E) end-capping in N-methyl-2-pyrrolidone at a polymer/solvent ratio of 20/80% (w/w). Mean in vitro drug release in 0.05 M phosphate buffer pH 7.4 with 1% (w/v) sodium lauryl sulphate was 37.3, 47.1, 53.3, and 62.3% within 28 days for ISGs containing PLGA5050A, PDLLA, PLGA7525A, and PLGA7525E, respectively. The data suggested that drug release was primarily controlle…
El principio de proporcionalidad como criterio hermenéutico en la justicia constitucional
2011
RESUMEN. La presente contribución realiza un análisis crítico sobre la aplicación judicial del principio de proporcionalidad para la concretización del contenido material de los derechos fundamentales, en contraposición a las posturas divergentes, que señalan que este instrumento ha traído inseguridad al plano de la interpretación constitucional, dada la visión de los derechos fundamentales como principios y de establecer una jerarquía axiológica movediza, además de inestabilidad e imprevisibilidad a la solución del mismo conflicto en casos futuros. La visión que ofrecemos sitúa al principio de proporcionalidad como un instrumento de la hermenéutica constitucional, capaz de brindar una fund…
Comparison of imidazolium and pyridinium ionic liquids as the media for biphasic ethylene polymerization in the presence of titanocene catalyst
2009
Chloroglinianowe ciecze jonowe z kationem 1-n-oktylo-3-metylopirydyniowym [C8-β-mpy]+[AlCl4]- lub 1-n-oktylo-4-metylopirydyniowym [C8-γ-mpy]+[AlCl4]- zastosowano jako jedną z faz w dwufazowej polimeryzacji etylenu w układzie ciecz jonowa/heksan, prowadzonej wobec katalizatora tytanocenowego (Cp2TiCl2) aktywowanego AlEtCl2. Wydajności polimeryzacji i właściwości polimerów otrzymanych z udziałem wymienionych cieczy jonowych porównano z odpowiednimi wielkościami uzyskanymi wcześniej przy udziale cieczy imidazoliowej ([C8-mim]+ [AlCl4]-) (tabele 1 i 2). Stwierdzono, że wprowadzenie do układu pirydyniowych zamiast imidazoliowych cieczy jonowych skutkuje wzrostem całkowitej wydajności procesu, wi…
Interaction of mushroom tyrosinase with aromatic amines, o-diamines and o-aminophenols
2004
3-Amino-L-tyrosine was found to be a substrate of mushroom tyrosinase, contrary to what had previously been reported in the literature. A series of amino derivatives of benzoic acid were tested as substrates and inhibitors of the enzyme. 3-Amino-4-hydroxybenzoic acid, 4-amino-3-hydroxybenzoic acid and 3,4-diaminobenzoic acid were oxidized by this enzyme, as previously reported for Neurospora crassa tyrosinase, but 4-aminobenzoic acid and 3-aminobenzoic acid were not. Interestingly, 3-amino-4-hydroxybenzoic acid was oxidized five times faster than 4-amino-3-hydroxybenzoic acid, confirming the importance of proton transfer from the hydroxyl group at C-4 position. All compounds inhibited the m…
The C–I･･･⁻O–N⁺ Halogen Bonds with Tetraiodoethylene and Aromatic N-oxides
2020
The nature of C–I⋯⁻O–N⁺ interactions, first of its kind, between non-fluorinated tetraiodoethylene XB-donor and pyridine N-oxides (PyNO) are studied by single-crystal X-ray diffraction (SCXRD) and Density Functional Theory (DFT) calculations. Despite the non-fluorinated nature of the C2I4, the I⋯O halogen bond distances are similar to well-known perfluorohaloalkane/-arene donor-PyNO analogues. With C2I4, oxygens of the N-oxides adopt exclusively 2-XB-coordination in contrast to the versatile bonding modes observed with perfluorinated XB-donors. The C2I4 as the XB donor forms with PyNO’s one-dimensional chain polymer structures in which the C2I4⋯(μ-PyNO)2⋯C2I4 segments manifesting two bondin…
Isolation of a Stable, Acyclic, Two-Coordinate Silylene
2012
The synthesis and characterization of a stable, acyclic two-coordinate silylene, Si(SArMe6)2, (ArMe6 = C6H3-2,6(C6H2-2,4,6-Me3)2) by reduction of Br2Si(SArMe6)2 with a magnesium(I) reductant is described. It features a v-shaped silicon coordination with a S-Si-S angle of 90.519(2)° and an average Si-S distance of 2.158(3) Å. Although it reacts readily with an alkyl halide, it does not react with hydrogen under ambient conditions probably as a result of the ca. 4.3 eV energy difference between the frontier silicon lone pair and 3p orbitals. peerReviewed
CCDC 642893: Experimental Crystal Structure Determination
2007
Related Article: C.Peifer, D.Schollmeyer, M.Tschertsche, S.Laufer|2007|Acta Crystallogr.,Sect.E:Struct.Rep.Online|63|o1551|doi:10.1107/S1600536807009300
La tecnica del bilanciamento nella giurisprudenza dei tribunali internazionali
2023
La presente ricerca esamina il ruolo della tecnica del bilanciamento tra interessi, principi o valori nel ragionamento del giudice internazionale. Da un punto di vista tecnico, essa tenta di chiarire le funzioni che il bilanciamento può svolgere nell’ambito dell’esercizio della funzione giudiziaria internazionale, e quale sia la struttura dell’argomentazione giudiziaria che su essa si fondi, sempre che un approccio comune tra i diversi tribunali internazionali sia riscontrabile. Da un punto di vista di politica giudiziaria, intende fornire alcune possibili spiegazioni della diversa propensione dei diversi tribunali internazionali a fare ricorso a tale tecnica o, nella giurisprudenza di uno …
Reactive Compatibilization of PBT/EVA Blends with an Ethylene-Acrylic Acid Copolymer and a Low Molar Mass Bis-Oxazoline
2004
Polyesters and polyolefins form highly incompatible blends with poor properties and gross morphology that hinder any practical applications. In this work, the possibility to compatibilize an incompatible blend of poly(butylene terephthalate) (PBT) with ethylene vinyl acetate (EVA) by adding a bis-oxazoline compound, 2,2'-(1,3-phenylene)-bis(2-oxazoline) (PBO), and an ethylene acrylic acid copolymer (EAA) as compatibilizer precursors has been studied. The results indicate that the binary uncompatibilized blends show poor mechanical properties and a bad morphology with scarce adhesion between the phases. The situation is only slightly improved when the EAA is added while the best performance …