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C Kono

Publications and source records attributed to C Kono.

11 recordsLinked to original sources
PubMed2001

Evidence for intermolecular interaction between sulfonium and sulfide sulfur atoms and its application to synthesis of cyclic bis(disulfide) dimer.

On the basis of the remote Pummerer reaction of p-bis(alkylthio)-aromatic S-oxides, the intermolecular interaction between the sulfonium and sulfide sulfur atoms is described. (1) In marked contrast to the Pummerer reaction of 1b-d(3) with (CF(3)CO)(2)O (J. Org. Chem. 1999, 64, 3190-3195), the reaction of 3,3',5,5'-tetramesityl-4-(trideuteriomethylsulfinyl)-4'-(methylthio)biphenyl (1a-d(3)) as a sterically hindered analogue of 1b gave only 2a-d(2). (2) Both reactions of the two unsymmetrical regioisomers of 1-(ethylthio)-4-(methylthio)benzene S-oxide (5a and 5b) with (CF(3)CO)(2)O afforded a mixture of the mono-Pummerer products 6a and 6b, the bis-Pummerer product 7, and the bis-sulfide 8 in a similar ratio. The quenching at the initial stage of both reactions produced 5a, 5b, 8, and the bis-sulfoxide 10 in a similar ratio. These results indicate the equilibrium in the intermolecular interaction between the sulfur atoms. (3) The reaction of the p-bis(benzylthio)-aromatic S-oxide 16 with (CF(3)SO(2))(2)O gave the cyclic bis(disulfide) dimer 17 for the diphenyl sulfide and diphenylmethane spacers or the cyclic tetrakis(disulfide) tetramer 19 for the benzene and biphenyl spacers via the debenzylation of an intermolecular dithia dication. The cyclic bis(dithia dication) dimer A resulting from the intermolecular interaction between the sulfonium and sulfide sulfur atoms is proposed as an intermediate throughout the present reactions.

Journal Article↗
PubMed1997

Dysphagia in children with oculo-auriculo-vertebral spectrum.

Feeding difficulty necessitating tube feeding after the infantile period was seen in 3 children with oculo-auriculo-vertebral spectrum. Videofluorographic imaging showed impaired pharyngeal function, which was thought to result from dysplasia of the pharyngeal muscles. Note should be made of feeding difficulty in patients with oculo-auriculo-vertebral spectrum.

Child, Preschool↗
PubMed1995

Inherent bias in correlation averaged images.

The correlation averaging algorithm frequently used to enhance micrographs of repeating structures contains an inherent bias that favours images with larger pixel values or positive noise levels. This bias not only skews the composite image toward higher pixel values, but also distorts the image by increasing the value of high-valued pixels more than that of low-valued pixels. These errors are especially important in scanning probe microscopy images where the pixel value reflects a distinct height. A similar algorithm that uses a structure function in place of the correlation function eliminates this bias.

Bias↗
PubMed1995

Subsequent epilepsy in very-low-birthweight infants: a long-term follow-up study from birth.

We studied 197 survivors of 290 very-low-birthweight (VLBW, < 1,500 g) infants admitted to our neonatal intensive care unit from 1977 through 1982. The children were all followed until at least age 6 years (mean 10 years 6 months). Eight children (4.1%) had epilepsy: 5 had generalized, 2 had unilateral, and 1 had partial seizures. Two (1.0%) had active and poorly controlled epilepsy. Three had a history of epileptic seizures, but none for > or = 6 years, and 3 were no longer receiving antiepileptic drug (AED) treatment. Most (5 of 8) were severely multiply handicapped. As compared with VLBW children without epileptic seizures and neurodevelopmental abnormalities, VLBW children with epileptic seizures had a gestational age < 27 weeks, a weight < 1,000 g, severe perinatal complications as indicated by an Apgar score of < 4 at 5 min, and the need for long-term oxygen administration.

Apgar Score↗
PubMed1986

Mean platelet volume artifacts: the effect of anticoagulants and temperature on canine platelets.

Improper handling of specimens results in artifactually high Mean Platelet Volume (MPV) measurements limiting their usefulness as a clinical tool. MPV measurement and Scanning Electron Microscopy (SEM) were performed on split specimens collected from normal dogs using two anticoagulants and two temperatures over a period of 4 hours. Platelets exposed to EDTA and maintained at 4 degrees C (39.2 degrees F) exhibited the highest artifactual increase in MPV, while those exposed to citrate and maintained at 37 degrees C (98.6 degrees F) exhibited minimal change. The increase in MPV was accompanied by platelet shape change from a smooth disc to an irregular sphere with filopodia. It is recommended that citrated specimens maintained at 37 degrees C be used in all MPV measurements.

Journal Article↗