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This study presents a new fabrication method for high frequency nanomechanical resonators by utilizing carbon layers with embedded single walled carbon-nanotube layers. The carbon layers, fabricated by pyrolysis of photo- or electron beam resists, showed low-density and moderate Young's modulus which is suitable to sensitive nanodevices. The carbon-nanotube layers underneath carbon layers enhanced conductivity and Young's modulus while maintaining low-density of carbon nanoresonators. These two layers are fashioned into doubly clamped nanomechanical beams by electron beam lithography and carbon dry etching processes. Dynamic behaviors such as resonant frequency and Q-factor are investigated using magnetomotive detection method.

The recombinant vacuolating cytotoxin (rVacA) of Helicobacter pylori that retains native conformational epitopes was evaluated as a vaccine antigen for anti-H. pylori treatment.s1m1 vacA gene fraction encoding the mature VacA protein was expressed as a soluble protein in E. coli at low temperature. The efficacy of anti-rVacA antibody against VacA or H. pylori was assessed in vitro using AGS cells and in vivo using a murine model.The rabbit antisera against rVacA completely neutralized the vacuolating activity and partially inhibited the cell death induced by VacA in AGS cells. Oral immunization of C57BL/6 mice with rVacA plus CpG-oligodeoxynucleotide (ODN) as an ajuvant stimulated specific anti-VacA antibody and mucosal immune responses which correlated with decreased systemic immune responses and gastric urease activities (p0.05).The rVacA antigen possessing conformational epitopes may have potential as a vaccine component and may be useful in serological and histopathological analysis.

A dual-gate-controlled single-electron transistor with coupled dot geometry has been fabricated on a silicon-on-insulator structure. Coupled dots are defined by tunable gates which are designed to separately control the tunneling potential barriers to compensate for disorder due to size fluctuation in quantum dots. The Coulomb-blockade phenomena observed in linear and nonlinear transport regimes were found to be enhanced by the multidot coupling. The Coulomb staircase (nonlinear effect) appears more clearly with the increasing number of coupled dots, indicating definite suppression of the inevitable cotunneling process. In the linear regime, the frequency of Coulomb oscillation was able to be tuned by changing the interdot coupling strength. These results indicate that enhancement of the Coulomb blockade and tunability can be achieved through replacing the traditional single dot by gate-controlled multidots in future single-electron devices.

We present an electrochemical biosensor utilizing pyrolyzed carbon as a working electrode for the aptamer-based thrombin detection. The pyrolyzed carbon is fabricated by photolithography and thermal decomposition of photoresist in an N2 atmosphere. Physical and electrical properties of carbon thin film pyrolyzed with a positive photoresist, AZ9260, were studied for the biosensor application. Electron transfer resistance changes due to thrombin binding onto the carbon surface modified with thrombin aptamer were measured using electrochemical impedance spectroscopy techniques. Thrombin concentrations between 0.5 nM and 500 nM were detected by the electrochemical measurements.

We present label-free, real-time detection of streptavidin binding using the pyrolyzed carbon with a p-type conduction behavior in aqueous solution, which is functionalized with amine-conjugated biotin. Pyrolyzed carbon derived from AZ 5214E are fabricated by photolithography and photoresist thermal decomposition in a N2 atmosphere. The streptavidin-biotin interactions on the pyrolyzed carbon are detected successfully by current change after streptavidin binding.

Employment creation is the best way to achieve growth and equity at the same time: namely, “shared growth.” Yet it is not the sheer number of jobs, but the quality of newly created jobs, that is most important in the development process. Simply put, what matters is the number of good jobs created. Good jobs imply high-productivity, high-paying jobs with the possibility of promotion. In this regard, and in its particular path of private sector-led development, Korea has abundant lessons to offer.

We developed an easy-to-operate 10:1 voltage divider system which enables to calibrate the Zener voltage standard's 10 V output within an uncertainty of a few parts in 10/sup 8/ with well established 1 V standard like 1 V Josephson array. Using a Zener voltage standard for a 10-V current source of the divider, the ratio calibration became simple and easy without losing any significant accuracy. The estimated uncertainty of 10:1 ratio calibration is about 0.006 ppm (1 U/sub c/).

A 10 V calibration system at KRISS is described which allows the measurement of 10 V electronic voltage standards using 1 V Josephson array with the help of an automated 10:1 resistive voltage divider system. The overall uncertainty of a measurement (1/spl sigma/) at 10 V is less than 0.1 ppm. >

We present batch-fabricated carbon-based nanomechanical resonators which are laminated by a pyrolyzed carbon layer and single-walled carbon-nanotube network (C/CNT resonators). The embedded CNT layers simultaneously enhance the electrical conductivity (∼160-fold) and mechanical stiffness (10% higher Young’s modulus) compared to nonstiffened carbon-only resonators. Dynamic behaviors of the fabricated C/CNT and carbon-only resonators, including fundamental frequency, Q-factor, and frequency tuning characteristics show comparable performance to the silicon based resonators.

The electric and the magnetic transport properties of the loop-type Al/Al 2 O 3 /Al single-electron tunneling device were studied. Even for the sample with charging energy about one order of magnitude greater than the Josephson coupling energy, the magnetoresistance showed h /2 e -oscillation at low bias voltage, attributed to the phase-coherent pair tunneling. The behavior of the magnetoresistance depends on the gate voltage, showing large and noiseless oscillations with the even number of excess charges but small and noisy oscillations with the odd number of excess charges in the metal islands.

The authors present a biosensor using pyrolyzed electron beam resist nanostructures as an active conducting channel. Versatile, arbitrarily shaped nanostructures such as nanowires, nanodots, and suspended nanobridges are fabricated by a facile electron beam resist thermal decomposition method. The nanostructures typically show 15–21nm thickness, 100–200nm width, 0.6nm roughness, and p-type majority conduction with tailored resistivity of 5.2–0.75Ωcm. Streptavidin-biotin binding and pH dependent conductance modulation are demonstrated using pyrolyzed resist based devices.

We have observed a memory effect in an aluminum single-electron memory cell with a floating node. Electrons were injected to or emitted from the floating node by field emission, which was evidenced by the sudden change in the Coulomb oscillation of a single-electron transistor. With the compensating voltage applied to the back gate, the Coulomb oscillation could be completely suppressed if the gate voltage sweep direction was reversed. We found that the Coulomb-oscillation period changed with the ratio of control-gate to back-gate voltage, being fitted well to the expected formula.

By using a cw Ar+ ion laser beam, microscopic crystalline silicon rods ≈102 µm in diameter and ≈103 µm in height have been grown on a silicon substrate by pyrolytic dissociation of SiH4. The kinetics of lateral growth of the silicon rods is derived from the time integration of the Arrhenius equation using a reasonable assumption that the temperature on the edge of the deposit saturates inversely to the substrate temperature with illumination time. For the axial growth, excluding the initial transient growth, the same result as Bäuerle and his collaborators is derived. The influences of laser power and illumination time on the deposited diameter and height are found experimentally, and it is found that the derived theory agrees well with the experimental results.

The abundant supply of highly educated and motivated human resources, extremely favorable to the rapid growth of an export-led, labor-intensive manufacturing sector, has been the primary source of Korean economic development during the past quarter century. Now, the Korean economy is undergoing a tremendously rapid industrial structural change into an OECD-type of mature economy. This paper examines four sets of problems Korean labor will face in the transition period of the 1990s: changes in the age-sex-educational composition of the labor force; changes in the structure of labor demand, leading to possible skill mismatches; rising labor costs and reform in the remuneration system; moves toward participatory and democratic labor-management relations.

Background In previous work, we reported that Korean Red Ginseng saponin fraction (RGSF) showed anti-inflammatory activities in vitro and in vivo . Methods The present study investigated the radioprotective properties of RGSF by examining its effects on ionizing radiation (IR)-enhanced and lipopolysaccharide (LPS)-mediated inflammatory responses in murine macrophage cells. Results RGSF induced strong downregulation of IR-enhanced and LPS-induced proinflammatory responses such as nitric oxide (NO) production (Inhibitory Concentration 50 (IC 50 ) = 5.1 ± 0.8 μM) and interleukin-1β levels. RGSF was found to exert its radioprotective effects by inhibition of a signaling cascade that activated checkpoint kinase 2–nuclear factor-κB. In addition, RGSF strongly inhibited IR-enhanced LPS-induced expression of hemoxyganase-1, implying that the latter may be a potential target of RGSF. Conclusion Taken together, our data suggest that RGSF can be considered and developed for use as an effective radioprotective agent with minimal adverse effects.