A rhodium(II)-catalyzed asymmetric cyclooligomerization of bifunctional monomers possessing triazolyl and vinyl groups at 2,3- and 3,4-positions on the thiophene ring is studied. Structurally interesting cyclic dimers in which thienylene and cyclopropylene units are alternately connected are obtained as the major components. The eight-membered rings in the center are non-planar and adopt a tub-shaped conformation.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2020
An chiral Rh -catalyzed cyclooligomerization reaction of thiophenes having triazolyl and vinyl substituents at the 2- and 4-positions was studied. Structurally interesting cyclic trimers, having chirality that is ascribed only to the orientation of the 2,4-disubstituted thiophene rings, are obtained. The 2,4-disubstitution of the starting thiophene monomer allows production of each of the enantiomers.
View Article and Find Full Text PDFA 71-year-old man presented with hemothorax with cough, sputa and worsening dyspnea. On chest X-ray and computed tomography(CT), a huge tumor in the right upper lobe with hematoma and small amount of gas suggesting hemopneumothorax was revealed. No apparent lymphadenopathy nor intrapulmonary metastases were observed.
View Article and Find Full Text PDFBackground: Bevacizumab (Avastin(®)) was approved in Japan in April 2007 for patients with advanced or metastatic colorectal cancer. To address the limited clinical experience in Japanese patients, a post-approval surveillance study was undertaken in bevacizumab-treated patients in Japan.
Methods: Bevacizumab (5 or 10 mg/kg every 2 weeks) was administered with chemotherapy; patients were observed for 26 weeks from initiation of treatment.
4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a tobacco-specific nitrosamine, induced lung tumors in rodents and is likely involved in human lung cancer. 4-(Hydroxymethylnitrosamino)-1-(3-pyridyl)-1-butanone (HO-methyl NNK) glucuronide, a glucuronide of the reactive intermediate of NNK, has been identified in rats. The aim of this study is to estimate the role of HO-methyl NNK glucuronide in the tumorigenic effects of NNK.
View Article and Find Full Text PDFOne reason for the poor pitch performance in current cochlear-implant users may be the highly synchronized neural firing in electric hearing that lacks stochastic properties of neural firing in normal acoustic hearing. This study used three different electric stimulation patterns, jittered, probabilistic, and auditory-model-generated pulses, to mimic some aspects of the normal neural firing pattern in acoustic hearing. Pitch discrimination was measured at standard frequencies of 100, 250, 500, and 1000 Hz on three Nucleus-24 cochlear-implant users.
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