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Biomedical subjects

H Nam

Publications and source records attributed to H Nam.

5 recordsLinked to original sources
PubMed2000

A disposable amperometric sensor screen printed on a nitrocellulose strip: a glucose biosensor employing lead oxide as an interference-removing agent.

A new type of disposable amperometric sensor is devised by screen printing thick-film electrodes directly on a porous nitrocellulose (NC) strip. The chromatographic NC strip is then utilized to introduce various sample pretreatment layers. As a preliminary application, a glucose biosensor based on hydrogen peroxide detection is constructed by immobilizing glucose oxidase (GOx) on the NC electrode strip and by formulating a strong oxidation layer (i.e., PbO2) at the sample loading area, placed below the GOx reaction band. The screen-printed PbO2 paste serves as a sample pretreatment layer that removes interference by its strong oxidizing ability. Samples applied are carried chromatographically, via the PbO2 paste, to the GOx layer, and glucose is catalyzed to liberate hydrogen peroxide, which is then detected at the electrode surface. The proposed NC/PbO2 strip sensor is shown to be virtually insusceptible to interfering species such as acetaminophen and ascorbic and uric acids and to exhibit good performance, in terms of the sensor-to-sensor reproducibility (standard deviation, +/-0.026 - +/-0.086 microA), the sensitivity (slope, -0.183 microA/mM), and the linearity (correlation coefficient, 0.994 in the range of 0-10 mM).

Biosensing Techniques↗
PubMed1998

Microtiter plate-format optode.

Microtiter plate-format optodes could be assembled by casting bulk-response membranes into the standard 96-well polypropylene-based plate or by screen printing them on an optically transparent substrate with 96-well pattern. The compositions of thick optode membranes, especially the ratios of poly(vinyl chloride) (PVC) to plasticizer [bis-(2-ethylhexyl) sebacate (DOS)], were carefully optimized to provide reproducible and rapid response. Adjusting the ratio of PVC to DOS by 1:6, bulk-response membranes containing neutral carrier (4-tert-butyl calix[4]arene tetraacetic acid tetraethyl ester for sodium-selective membrane or valinomycin for potassium-selective membrane) and lipophilic pH indicator (ETH 5294) could exhibit equilibrium response in 5 min. The practical utility of microtiter plate-format optodes has been examined by determining clinically relevant electrolytes in serum samples. It was demonstrated that microtiter plate-format optodes can provide high sample throughput (approximately 100 samples in less than 5 min), analytical performance comparable to that of a potentiometric clinical analyzer, and additional information on electrolytes using the same samples prepared for other colorimetric measurements.

Animals↗
PubMed1998

Results of thoracoscopic sympathectomy for 96 cases of palmar hyperhidrosis.

From August 1996 to August 1997, we performed thoracoscopic sympathectomy for 96 cases of palmer hyperhidrosis. The patients' ages were from 22 to 58 years old (mean age: 28; gender ratio: male/female: 3/2). Most of them were students, workers or clerks. The patients were divided in two series: in 61 patients, the sympathetic chain before the 2nd to 4th ribs was removed in the lateral approach with a 3 hole procedure. In 35 patients, the 2nd portion of the sympathetic chain was destroyed (by electric cauter) in the posterior approach with a 2 hole procedure. The results were almost the same in the first series (all cases have a fair benefit), but in the second series, some advantages may be useful for therapy, i.e no need to turn the patients, severe compensation sweating is minimized (from 4% ==> 0%) and the amount of holes is reduced.

Adrenergic Fibers↗
PubMed1997

Vibrational Assignment and Anharmonic Resonance Analysis of the Dispersed Fluorescence and Stimulated Emission Pumping Spectra of DFCO (S 0 ) up to 9000 cm-1

Dispersed fluorescence and stimulated emission pumping spectra of jet-cooled DFCO from the 2(1) 6(2) , 5(1) 6(4) , 2(1) 5(1) 6(2) , and 5(1) 6(6) vibrational states of S 1 are presented up to 9000 cm-1 . Progressions are assigned primarily to vibrational states with excitation in the Franck-Condon active modes nu2 , nu5 , and nu6 . The spectrum is perturbed by a 266 (nu2 approximately 2nu6 ), a 233 (nu2 approximately 2nu3 ), and a 3566 (nu3 + nu5 approximately 2nu6 ) anharmonic resonance. These three resonances are increasingly important at high vibrational energies, thus explaining the complexity of the DFCO spectrum compared to that of HFCO. Seventy-five vibrational states are assigned as eigenstates of a 266, 233, and 3566 anharmonic resonance Hamiltonian. The rms deviation in the calculated energies is 1.2 cm-1 . Harmonic frequencies and anharmonic constants are reported. These are compared to constants derived from ab initio potential energy surfaces.

Journal Article↗