[Show abstract][Hide abstract] ABSTRACT: The Nernst equations between the oxidation-reduction potential (ORP), the concentration of hypochlorous acid and chlorine and the value of pH in electrolyzed oxidizing water (EOW) were developed in three parts, which were in agreement in the measured values. The role of ORP in EOW for killing Escherichia coli O157:H7 was studied. The inactivation effect of EOW on E. coh O157:H7 was also studied by spectroscopy measurements, and the inactivation mechanism was proposed. (c) 2006 Elsevier Ltd. All rights reserved.
Preview · Article · Feb 2007 · Journal of Food Engineering
[Show abstract][Hide abstract] ABSTRACT: Semipermeable membrane devices (SPMDs) were developed for passive in situ monitoring of organochlorine pesticides (OCPs) in aqueous solution in both laboratory and field (Pearl River Delta, China) studies. The device consisted of a thin film of neutral lipid triolein, enclosed in thin-walled tubing made of composite cellulose acetate membrane (CA) supported by linear low density polyethylene (LLDPE) (CAPE). Results from the laboratory and field application indicated that triolein-CAPE (TCAPE) could quickly and efficiently accumulate hydrophobic OCPs in water and uptake equilibrium could reached within 20h in the laboratory. Some mathematical relationships of TCAPE-water partition coefficient (logK(sw)), triolein-water partition coefficient (logK(tw)) and octanol-water partition coefficient (logK(ow)) were developed under the laboratory conditions. A good correlation of accumulation in TCAPE with r(2) values ranging from 0.55 to 0.86 for individual OCPs (n=8) and an excellent correlation of logK(sw) and logK(ow) was also obtained under the field conditions. The average OCPs concentration in the surface water could be estimated by measuring OCPs concentration in the device under the field conditions.
[Show abstract][Hide abstract] ABSTRACT: By using solid phase methods (ferrocenyl peptide) conjugate-DNA complexes are formed, in which the peptide sequence is YKKAA. The identity of a DNA target can be determined by E1/2 (half-wave potential) of ferrocenyl peptide complexes and the ratio of peak currents. Additionally, these conjugate-DNA complexes exhibit predictable and trackable electrochemical properties, high DNA duplex stability, and specific sharp melting transitions. Experiments for the detection of single-base match by utilizing two signaling probes are carried out, and the results demonstrate that rapid and accurate detection of a single-base mismatch can be achieved by using these dual-signaling probes. The conjugate-DNA interface of the nonspecific complexes is flexible on biologically relevant time scales that may assist in the rapid and efficient finding of the target site.
Preview · Article · May 2006 · Sensors and Actuators B Chemical
[Show abstract][Hide abstract] ABSTRACT: Surface enhanced Raman scattering of pyridine molecules was observed on crystalline rutile TiO2 (110) in an Ultra High Vacuum (UHV) chamber along with in situ scanning tunneling micrograph (STM) and Quartz Crystals Microbalance (QCM). It was interesting to note that a new Raman band at 247 cm(-1) appeared and we ascribed it to the Ti-N vibration between nitrogen of adpyridine molecule and titanium of TiO2. The site and azimuthal orientation of adpyridine molecules on TiO2 (110)-(1x1) surface were explicitly recorded by in situ STM. Besides the charge transfer mechanism, a mechanism was proposed to interpret the origin of the Raman intensity enhancement.
[Show abstract][Hide abstract] ABSTRACT: Photoirradiation of O-hydroxylcyclohexyletheramine-doxorubicin (dox) when bound to DNA exhibits high DNA cleavage efficiency and selectivity, leading to GG steps cleavage. Coupling ultraviolet absorption with viscosity measurement, the mode of dox–DNA complex is groove-binding. The three-dimensional structure from X-ray crystallography reveals that dox bound to DNA base pairs to groove reversal along with its antenna (hydroxylcyclohexylether-amine) in the major groove. We also provide a direct evidence of supporting a model that transfers electrons from base to dox and holes migrate within DNA.