Synthesis of a polynorbornene containing 3,5-di-TERT-butyl-4-hydroxybenzoyl group

Summary A new polynorbornene derivative was synthesized by ring-opening metathesis polymerization (ROMP) of 5- {[(3,5-di-t-butyl-4-hydroxy-benzoyl)oxy]methyl}-2-norbornene (BHBN) using Ru- and Os-based catalysts. The structure and properties of the poly(BHBN) were characterized by NMR, IR, DTA, DSC, and GPC. It was shown that ROMP leads to the formation of high molecular weight polynor-bornene derivatives containing the stabilizing group.     

Einfluß der Austenitausscheidung auf die Sensibilisierung eines Duplexstahls gegenüber interkristalliner Korrosion

Der Einfluß der Austenitausscheidung auf die Sensibilisierung gegenüber interkristalliner Korrosion wird an einem Duplexstahl Cr-Ni (24,4–7,4 %) untersucht. Zuvor wurden die Walzzustandsmorphologie des Duplexstahles durch thermische Behandlung zerstört und die Carbidausscheidungen in Lösung gebracht. Elektronenmikroskopie und Huey-Versuche verifizierten die Ergebnisse.     

Effect of defect orientation on metal fracture-statistical prognosis

Aluminium specimens of pre-caused defects are tensile tested at different temperatures. The defects are differently oriented to the tensile axis. The results have undergone statistical processing integrated with fundamental fracture approach. Analytical model to prognosticate the metal reliability in the range of applied tensile stresses is found. A method for evaluation of the defects orientation effect on fracture is suggested. The introduced strength spaces present a principal strength history of loaded defect metal.     

Mechanical properties of carbon nanotubes: a fiber digest for beginners

A condensed review of mechanical properties of carbon nanotubes is given. Theory as well as experiments is examined with a view to extracting the fundamental elements that should allow the reader to build his own perspective of the subject.     

Relative incorporation of linoleic and arachidonic acid in phospholipids and triglycerides of different rat tissues

Fat-deficient rats were fed different amounts of methyl linoleate for increasing periods of time. The fatty acid composition of triglycerides and phospholipids of epididymal fat pad, epirenal fat depot, intestinal fat depot, liver, and the pool of heart, kidney, lungs and pancreas was determined. The distribution of the total amount of linoleic and arachidonic acid incorporated into phospholipids and triglycerides per rat was calculated. Phospholipids and triglycerides of depot tissues presented different fatty acid compositions. Although the phospholipids of liver and the pool of heart, kidney, lung and pancreas specifically incorporated linoleic acid at the beginning they very rapidly attained a rather steady composition, whereas triglycerides went on incorporating the acid. The amount of linoleic acid incorporated into the phospholipids of depot tissues was rather small. The triglycerides undoubtedly contributed in the highest proportion to the total pool of linoleic acid. However, the highest proportion of arachidonic acid was found in the total pool of phospholipids. The total amount of linoleic acid incorporated into the phospholipids was an approximately lineal function of the amount of phospholipids independent of period of administration and doses of methyl linoleate. Besides presenting two lineal functions of the amount of phospholipids, arachidonic acid showed a vertical increase coincident with a vertical decrease of the amount of eicosa-5,8,11-trienoic acid. At this period no change in the amount of the phospholipid was shown. This phenomenon is explaioned as a possible direct replacement of eicosatrienoic acid by arachidonic acid.     

Soft plasma processing of organic nanowires: a route for the fabrication of 1D organic heterostructures and the template synthesis of inorganic 1D nanostructures

Hierarchical (branched) and hybrid metal-NPs/organic supported NWs are fabricated through controlled plasma processing of metalloporphyrin, metallophthalocyanine and perylene nanowires. The procedure is also applied for the development of a general template route for the synthesis of supported metal and metal oxide nanowires.     

Synthesis and anticancer activity of the (R,S)-benzofused 1,5-oxathiepine moiety tethered to purines through alkylidenoxy linkers

Herein we report the design, synthesis, and anticancer activity of a series of substituted (R,S)-9-[2- or 3-(3,4-dihydro-2H-1,5-benzoxathiepine-3-yloxy)alkyl]-9H-purines. Derivatives with propylenoxy-linked 2',6'-dichloro- and 6'-bromopurines are more active than their respective ethylenoxy-linked purine conjugates. On the other hand, the compound with a propylenoxy-linked 6'-chloropurine is nearly equipotent to the corresponding ethylenoxy-linked conjugate. Our results show that bromo- and chloropurine-conjugated benzoxathiepines containing a propylenoxy linker are able to inhibit PI3 kinase (PI3K) phosphorylation in MCF-7 breast cancer cells, indicating that the activation of eIF2α, together with inhibition of the PI3K pathway, is the mechanism of action by which these compounds effect their antitumor activity in the MCF-7 cell line; apoptosis was induced in a p53-independent manner.     

Guided assembly of metal and hybrid conductive probes using floating potential dielectrophoresis

We present the site-selective, parallel and reproducible formation of conductive gold and tetrathiafulvalene-gold (TTF-Au) hybrid micro- and nanowires from their respective ion salt and cation-radical solutions. While the formation of micro- and nanowires by means of dielectrophoresis with directly coupled electrodes has been thoroughly investigated in recent studies, we present here the first relevant example of metal and hybrid wire assembly obtained by floating potential dielectrophoresis. In this configuration, the assembly of micro- and nanowires is achieved by capacitively coupling a large electrode (bias electrode) to a conductive substrate (p-doped Si) separated by an insulating oxide layer. In contrast to former studies, this allows parallel production of micro- and nanowires with only one pair of electrodes connected to a sine wave generator. We further demonstrate that these structures are suitable probes for localized surface enhanced Raman spectroscopy (SERS).