Fuel cell applied research: electrocatalysis and materials. Quarterly report, January 1-March 31, 1979

In situ regeneration of surface areas of sintered carbon supported platinum electrodes in 85% H/sub 3/PO/sub 4/ at 150/sup 0/C was studied. The kinetics of oxygen reduction on platinum in trifluoromethane sulfonic acid was investigated. Overpotentials in solid oxide electrolyte fuel cells were studied. Results are presented and discussed. Also, a survey of the status of studies of phosphoric acid and molten carbonate fuel cells is described. (WHK

Fuel cell applied research: electrocatalysis and materials. Quarterly report, July 1-September 30, 1978

A study was undertaken to investigate the electrocatalysis of the formic acid and methanol oxidation reactions at underpotentially deposited metal surfaces at 25/sup 0/C. The test electrode was a smooth polycrystalline platinum disc, on which a metal Bi, Cd, Pb or Tl was underpotentially deposited (UPD) by potential cycling in 1 N HClO/sub 4/. The organic reactant (HCOOH or CH/sub 3/OH) was added to this electrolyte so that its concentration was 0.26 M. Cyclic voltammograms were recorded on the Pt (control) and on the UPD test electrodes at a sweep rate of 50 mV/sec in the potential range of 0 to 1.45 V/RHE. Results are reported. Also, overpotentials in solid electrolyte fuel cells were studied. Alternating and direct current techniques were used to determine the impedance characteristics at the platinum-yttria stabilized zirconia (YSZ) interface in the regions of potentials where the oxygen evolution and reduction reactions take place. The measurements were conducted as a function of time to elucidate aging effects on the kinetics of these reactions. Experiments were conducted at 1000/sup 0/C in the potential range of -600 to +600 mV vs an air reference electrode. Results are presented and discussed. (WHK

Fuel cell applied research: electrocatalysis and materials. Quarterly report, April 1-June 30, 1979

Topics studied include: (1) oxygen reduction and cyclic voltammetry on carbon supported platinum electrodes in 85% H/sub 3/PO/sub 4/; (2) oxygen reduction on platinum in 85% H/sub 3/PO/sub 4/ with small additions of trifluoromethane sulfonic acid or trifluoracetic acid; (3) overpotential characteristics of electrodes at interfaces with solid oxide electrolytes; and (4) oxygen diffusion through interconvection material in high temperature solid electrolyte fuel cells. Also, studies of phosphoric acid and molten carbonate fuel cell technologies are surveyed. (WHK

BRCA1 genomic deletions are major founder mutations in Dutch breast cancer patients

Contains fulltext : 25346___.PDF (publisher's version ) (Open Access

A high proportion of novel mutations in BRCA1 with strong founder effects among Dutch and Belgian hereditary breast and ovarian cancer families

Contains fulltext : 25573.PDF (publisher's version ) (Open Access

BRCA1 genomic deletions are major founder mutations in Dutch breast cancer patients

To date, more than 300 distinct small deletions, insertions and point mutations, mostly leading to premature termination of translation, have been reported in the breast/ovarian-cancer susceptibility gene BRCA1. The elevated frequencies of some mutations in certain ethnic subpopulations are caused by founder effects, rather than by mutation hotspots. Here we report that the currently available mutation spectrum of BRCA1 has been biased by PCR-based mutation-screening methods, such as SSCP, the protein truncation test (PTT) and direct sequencing, using genomic DNA as template. Three large genomic deletions that are not detected by these approaches comprise 36% of all BRCA1 mutations found in Dutch breast-cancer families to date. A 510-bp Alu- mediated deletion comprising exon 22 was found in 8 of 170 breast-cancer families recruited for research purposes and in 6 of 49 probands referred to the Amsterdam Family Cancer Clinic for genetic counselling. In addition, a 3,835-bp Alu-mediated deletion encompassing exon 13 was detected in 6 of the 170 research families, while an deletion of approximately 14 kb was detected in a single family. Haplotype analyses indicated that each recurrent deletion had a single common ancestor