D Marshall Porterfield

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Single-celled spores of the fern Ceratopteris richardii undergo gravity-directed cell polarity development that is driven by polar calcium currents. Here we present results that establish a role for nitric oxide (NO)/cGMP signaling in transducing the stimulus of gravity to directed polarization of the spores. Application of specific NO donors and scavengers(More)
Large and/or aged seeds are prone to hypoxic conditions during germination. Germination of selected vegetable seeds including corn (Zea mays L.), squash (Cucurbita pepo L.), and tomato (Solanum lycopersicum L.) was studied in water with different concentrations of hydrogen peroxide (H 2 O 2) solution ranging from 0, 0.06% to 3.0% (v/v) or in aeroponics, all(More)
This study was designed to investigate the impact of 1,25-dihydroxyvitamin D (1,25(OH)2D) on glucose metabolism during early cancer progression. Untransformed and ras-oncogene transfected (ras) MCF10A human breast epithelial cells were employed to model early breast cancer progression. 1,25(OH)2D modified the response of the ras cells to glucose(More)
  • Chang-Soo Kim, Chang-Soo bullet, H Troy Kim, Charles W Nagle, Stefan Scarantino, Jason O Ufer +21 others
  • 2008
Methods of calibrating in vivo sensor systems using in vivo generating electrodes and related devices, International patent WO0122874. and associated implantable devices for dynamic monitoring of physiological and biological properties of tumors, US patent 6,402,689, 2002. Enhanced wettability of SU-8 photoresist through a photografting procedure for(More)
Physiological studies require sensitive tools to directly quantify transport kinetics in the cell/tissue spatial domain under physiological conditions. Although biosensors are capable of measuring concentration, their applications in physiological studies are limited due to the relatively low sensitivity, excessive drift/noise, and inability to quantify(More)
Single-celled spores of the fern Ceratopteris richardii undergo gravity-directed cell polarity development that is driven by polar calcium currents. Here we present results that establish a role for NO/cGMP signaling in transducing the stimulus of gravity to directed polarization of the spores. Application of specific NO donors and scavengers inhibited the(More)
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