The synthesis of 6H-benzo[c]chromenes from unactivated 2-bromo aryl benzyl ethers was studied through two approaches: (i) the transition-metal-free intramolecular dehydrohalide coupling via intramolecular homolytic aromatic substitution; and (ii) the intramolecular cyclization via direct C–H arylation catalysed by PdCl2(MeCN)2. Having developed the most efficient method, a 17-membered chromene ...

We report on the preparation of large-scale uniform bilayer graphenes on nominally flat Si-polar 6H-SiC(0001) substrates by flash annealing in ultrahigh vacuum. The resulting graphenes have a single thickness of one bilayer and consist of regular terraces separated by the triple SiC bilayer steps on the 6H-SiC(0001) substrates. In situ scanning tunneling microscopy reveals that suppression of p...

SiC based capacitive devices have the potential to operate in high temperature, chemically corrosive environments provided that the electrical integrity of the gate oxide and metallization can be maintained in these environments. We report on the performance of large area, up to 8 x 10 -3 cm, field-effect capacitive sensors fabricated on both the 4H and 6H polytypes at 600°C. Large area capacit...

The title compound, (C(10)H(10)N(2))(2)[SiW(12)O(40)]·C(10)H(8)N(2)·6H(2)O or (4,4'-bipyH(2))(2)[SiW(12)O(40)].(4,4'-bipy)·6H(2)O (4,4'-bipy is 4,4'-bipyridine), was prepared under hydro-thermal conditions. The asymmetric unit contains a discrete Keggin-type [SiW(12)O(40)](4-) anion (located on a twofold axis), one 4,4'-bipy (located on a twofold axis), two (4,4'-bipyH(2))(2+) cations and six u...

Nanosized copper aluminate (CuAl(2)O(4)) spinel particles have been prepared by a precursor approach with the aid of ultrasound radiation. Mono-phasic copper aluminate with a crystallite diameter of 17nm along the (311) plane was formed when the products were synthesized using Cu(NO(3))(2) x 6H(2)O and Al(NO(3))(3) x 9H(2)O as starting materials, with urea as a precipitation agent at a concentr...

We report the utilization of key design parameters to simulate, batch-fabricate and evaluate first-generation single crystal 6H-SiC piezoresistive accelerometers for extreme impact, high electromagnetic fields (EM) and high temperature applications. The results from finite element analysis (FEA) of the selected design models were compared to evaluated prototypes. While FEA results predicted saf...

6-chloro-5-ethyl-, n-propyl- and isopropyluracils 5a-c were efficiently prepared from the corresponding 5-alkybarbituric acids 3a-c via treatment with phosphorus oxychloride and N,N-dimethylaniline to yield the corresponding 5-alkyl-2,4,6-trichloro-pyrimidines 4a-c, which were selectively hydrolyzed by heating in 10% aqueous sodium hydroxide for 30 minutes. The reaction of compounds 5a-c with 1...

A series of pyranopyrazoles, namely, 7-(2-aminoethyl)-3,4-dimethyl-1-phenyl-1H-pyrazolo[3,4-b]pyridin-6(7H)-one (2), (Z)-3,4-dimethyl-1-(4-((4-nitrobenzylidene)amino)phenyl)pyrano[2,3-c]pyrazol-6(1H)-one (5), 1-(4-(3,4-dimethyl-6-oxopyrano[2,3-c]pyrazol-1(6H)-yl)phenyl)-3-(naphthalen-1-yl)urea (6), (Z)-ethyl 4-((3,4-dimethyl-6-oxo-1,6-dihydropyrano[2,3-c]pyrazol-5-yl)diazenyl)benzoate (8) and 3...

Abstract Heterocyclic amines (HCAs) are toxic products from the Maillard reaction that form of sugars, amino acids and creatine/creatinine when cooking protein rich food. In this work, commonly consumed meats in Saudi Arabia (camel, beef chicken) were fried under conditions resembling home cooking. The effect marinades made blueberry, raspberry strawberry tested separately on meat at different ...

To determine whether Aloe vera (AV), a traditional herbal medicine, could maintain homeostasis, we investigated its ability to regulate the production of hormones, particularly thyroid hormones. T4 ELISA assay with (6H media) and without thyrotropin (TSH) (5H showed that AV functions endocrine homeostasis. understand mechanisms by which regulates thyroxine release, confirmed protein expression ...