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The Enzyme Linked Immunosorbent Assay (ELISA) technique has been widely used for the identification and quantification of biochemical markers. The typical ELISA requires a number of washing steps to eliminate the unbound proteins which sometimes cause the desorption of protein due to their weak bonding between protein and well plate. In this study, we have developed a meshed type of plastic membrane in order to increase the reliable binding efficiency between proteins and the membrane surface, and to provide easy steps of washing. The use of our developed solid membrane has significantly increased the binding capacity of the biomolecules because this membrane ELISA (mELISA) provides 3D binding surfaces which increases the surface area when compared to the conventional 2D surface well plate. The columns were pretreated to form a self-assembled layer (SAM) on the surface for the stable conjugation of a target antibody. The SAM-coated membranes could be stored for one month without any further deterioration of stability. The measured optical density (O.D.) shows a 1.2-fold increase in IgG antigen (25 &mu, g/mL) from the plastic membrane as compared with the conventional ELISA method. The concentrations of thyroid stimulating hormone were also monitored using the mELISA method and it shows good linearity against the concentrations.

In this study, we considered the toxicity of the combustion gases for the indoor floor materials such as carpet tiles, rubber tiles, decorated tiles, monorium, and PVC vinyl asbestos using the cone calorimeter and the NDIR analysis equipments. Only 5 types of gases (CO, , , NO and ) were selected to analyze among the combustion gases because of the limitations of NDIR equipment. For monorium the concentrations of , CO and were relatively higher and the maximum concentration of was 13 times higher than rubber tiles. Especially, the maximum concentration of CO was 3.09 times higher than PVC vinyl asbestos and it was 3.0~9.2 times higher than the permissible concentration of 50 ppm. For carpet tiles the concentration of NO was relatively higher and it was 2.9 times higher than rubber tiles. Also, the maximum concentration of was 2.25 times higher than PVC vinyl asbestos but it was lower than the hazardous concentration of 117~154 ppm. Therefore, the danger of and CO was considered to be much higher in fires with monorium.

In this study, temperature characteristics and fire damage form were analyzed to investigate flame spreading form and fire probability from ignition sources subject to drivit component materials which is finishing material in architecture. Ignition sources were limited to a gas torch and exterior panel board fire, and the size of the sample was manufacture in 30 cm length 50 cm height 5cm thickness size. Marble (inner wall) + 3 mm drivit (outer wall), marble (inner wall) + 4 mm plaster stone (outer wall), sandwich panel + 3 mm driver bit (outer wall), sandwich panel + 3 mm driver bit + insulation (outer wall), and gypsum board (inner wall) + 3 mm drivit (outer wall) were prepared for the sample. As result of the research for temperature characteristics, large temperature difference by each material was shown in at 30 seconds and at 300 seconds. Especially when the inner wall was a plaster board, lowest temperature of was shown at 300 seconds and marble inner wall showed the following lowest temperature of . Temperature rising over was shown in other materials. Regarding fire damage form, drivit or gypsum board outer wall parts exposed to fire showed combustion and carbonization to show calcination(breaking phenomenon) and influence of heat exposure was higher as calcination became more severe.

Current clinical trials of new anticancer therapies against metastatic renal cell carcinoma (RCC), including molecular‐targeted therapies, have not shown promise. The purpose of this study was to preclinically assess the antitumor effects of MC‐4, a partially purified material of Artemisia annua L., as a monotherapy or in combination with the known mechanistic target of rapamycin complex 1 (mTORC1) inhibitor, everolimus, against Caki‐1 (Von Hippel‐Lindau (VHL)+/+) and 786‐O (VHL−/−) human RCC cells. MC‐4 monotherapy significantly increased tumor growth inhibition and autophagic cell death in RCC cells in vitro and in vivo. Everolimus led to compensatory Akt activation by inhibiting only mTORC1 signaling pathway. In contrast to everolimus, MC‐4 enhanced phosphatase and tensin homolog expression and reduced its downstream effector, Akt/pyruvate kinase muscle isozyme M2 (PKM2), leading to decreased expression of glucose transporter 1, which is associated with cancer cell metabolism. The synergistic antitumor and anti‐metastatic effects induced by co‐administration of MC‐4 and everolimus involve cell growth inhibition and autophagic cell death via dual targeting of phosphatidylinositol 3‐kinase (PI3K)/Akt/PKM2 and mTORC1. These findings suggest that MC‐4 is a novel Akt/PKM2 inhibitor that can overcome the limitation of existing mTOR inhibitors and can be considered a novel strategy to treat patients with rapidly progressing advanced RCC.

[Purpose] The aim of this study was to examine the effects of community-based rehabilitation program in chronic stroke patients. [Subjects and Methods] Eleven subjects received community-based rehabilitation program ten times for ten months. The main outcome measures were the Modified Barthel Index score for activities of daily living and the Korean Mini-Mental State Examination score for cognition. [Results] The results of the study demonstrated that the community-based rehabilitation program improved activities of daily living performance and cognition significantly. [Conclusion] Based on the study results, the community-based rehabilitation program is an effective method for improving activities of daily living performance and cognitive function in elderly patients with chronic stroke.

Although a large number of microRNAs (miRNAs) have been identified in different plant species, the functional roles and targets of the majority of miRNAs have not yet been determined. Here, Arabidopsis thaliana miRNA400 (miR400) was investigated for its functional role in the defense response to diverse pathogens. Transgenic Arabidopsis plants that overexpress MIR400 (35S::MIR400) displayed much more severe disease symptoms than the wild-type plants when infected with the bacterium Pseudomonas syringae pv. tomato DC3000 or the fungus Botrytis cinerea. MiR400 guided the cleavage of two genes (At1g06580 and At1g62720) encoding pentatricopeptide repeat (PPR) proteins. To confirm further that the miR400-mediated defense response was due to the cleavage of PPR mRNAs, loss-of-function mutant and artificial miRNA-mediated knockdown mutants of PPR were generated, and their disease responses were analyzed upon pathogen challenge. Similar to the 35S::MIR400 plants, the ppr mutants displayed much more severe disease symptoms than the wild-type plants when challenged with the pathogens, indicating that miR400 affects the defense response by cleaving PPR mRNAs. Expression of miR400 was down-regulated, whereas the PPR1 and PPR2 transcripts increased upon pathogen challenge. Collectively, the present study reveals that miR400-mediated dysfunction of PPR proteins renders Arabidopsis more susceptible to pathogenic bacteria and fungi, which emphasizes the importance of PPR proteins in plant defense against diverse pathogens.

The purpose of this study is to conduct the study of the combustion and thermal characteristics through transportation oil for the analysis of fire hazard. Transportation oil breaks down into fuels such as diesel for civilian demands, gasoline, DF1(diesel for military), high sulfur diesel(for marine), kerosene and JP1(for aviation), and lubricants like brake fluid, power steering oil, engine oil, and automatic and manual transmission oil. The experiments of flash point, ignition point, flame duration time, heat release rate were carried out using TAG closed cup flash point tester(AFP761), Cleveland open cup auto flash point analyzer(AFP762), KRS-RG-9000 and Dual cone calorimeter. As a result, the fuel's ignition points were lower than lubricants, especially that of gasoline was not conducted as it has below zero one. Gasoline has the highest ignition point of about 600℃, while the other fuels showed 400~465℃. For flame duration time, lubricants had over 300 seconds, but fuels had less than 300 seconds except high sulfur diesel(350 seconds). Total heat release rate ranged 287~462 ㎾/㎡ for lubricants and gasoline showed the highest total heat release rate, 652 ㎾/㎡.

This study analyzed various possibilities of flash fire which could occur in a variety of combats, in order to predict that of flash fire of combat system armor using Autodyn program. The possibility was judged by the temperature distribution of fuels, which was caused by the impact of parts of fuel systems through an armor, in the event of getting shot by external ammunition. Diverse variables could affect the possibility of flash fire: external ammunition(Type A: penetration 570 mm, Type B: penetration 410 mm), fuels(Gasoline, Diesel, Kerosene), the thickness of an armor(100, 200, 300, 400, 500 mm), the gap of a fuel tank and an armor(45, 95, 145, 195, 245, 295 mm). As a result, when an armor was 20 mm think, the temperature of 3 fuels ranged like this: Gasoline 372~387 K, Diesel 442~408 K, Kerosene 384~395 K. Although they made a little difference among them, they all didn't reach their ignition points. When an armor was 200 mm think, each fuel reached the maximum temperature, not reaching its ignition points as well. The thicker an armor was, the lower the temperature got. When Type B ammunition was used, the temperature of fuels went up 19~59 K higher than Type A was used. In the case that the gap of fuel tank and an armor was 20 mm thick, the temperature distribution of Gasoline showed 389~450 K, the maximum temperature appeared in the gap of 145 mm, and the minimum temperature 295 mm. For Type B, the temperature distribution of fuels ranged 386~401 K, the maximum temperature appeared in the gap of 245 mm, and the minimum temperature 45 mm. There was no significant difference between two cases, and neither of them reached its ignition point. Accordingly, as the tested fuels of combat systems didn't reach their ignition points, it is thought that the possibility of flash point of an armor is low.

In this study, we have investigated the maximum smoke density and the initial stage smoke density in order to see the characteristics of smoke release of the architectural surface materials and the architectural adhesives, using smoke density chamber. As a result of the study, polyurethane foam showed the highest smoke density index, 206.55 within 10 min. In the case of the other samples, reinforced styrofoam was followed as 39.90, general styrofoam 33.73, and glass fiber 5.40, respectively. In the intial stage of a fire, it is forecasted actually to give hardship at the clear visibility. In the case of architectural adhesives, the highest ranking was those for windows and doors 509.64, stone 275.63, wood 232.25, tile 18.65, and styrofoam 6.44 were followed, respectively. This result is an early research to show characteristics of smoke release through experiment. However, it is meaningful that this study can be used as a basic for further study on architectural fire hazard prediction.

Oblique facial cleft is a rare congenital deformity. Its incidence has been reported as 0.24% of all reported cases of facial cleft. We report on a patient who had a left-sided oblique facial cleft with anopthamia, including lip and palate, nose alar base, and medial canthus. The patient also had a right-sided oblique facial cleft, which included lip and palate, nose alar base, medial canthus, and upper eye brow. Primary closure of the facial cleft was performed using multiple Z-plasty after excision of scar tissue.

Botulinum toxin type A (BTX-A) inhibits muscle contraction, which leads to reversible muscle atrophy and paralysis. Therefore, BTX-A injection can be an effective treatment of facial asymmetry that originated from the uncoordinated muscle movement. A 52-year-old patient was referred from another hospital for the correction of post-traumatic sequelae. The patient had prominent scar in the mandibular symphysis area with asymmetric lower lip movement. The reason for this asymmetric lower lip movement was due to damage in the lower lip depressor muscle. After the injection of BTX-A on the lower lip depressors, asymmetric lip movement has been improved.

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a disease characterized by jaw necrosis and delayed wound healing in patients who had received bisphosphonates. Buccal fat pad (BFP) can be used as a pedicled flap in the posterior region of the oral cavity. BFP pedicle flap needs simple surgical technique and it shows less donor site morbidity and aesthetic problem than other vascularized flap. BFP pedicled flap was fed by 3 arteries- facial, internal maxillary, and transverse facial artery. Osteomyelitis was generally related with poor blood supply. Thus, rich blood supply of BFP pedicle flap can have a potential advantage to BRONJ patients. In this case report, we presented 3 BRONJ patients treated by BFP pedicle flap after sequestrectomy.

The purpose of this study was to investigate the effect of bile salts on gastrointestinal absorption and the plasma second peak phenomenon of roxithromycin in rats. The pharmacokinetic parameters of roxithromycin were calculated after single oral administration at a dose of 20 mg/kg in sham-operated (control), bile duct cannulated (BDC) and bile salt co-administered bile duct cannulated (BSBDC) rats. In BDC rats, the total area under the plasma concentration–time curve from time zero to time infinity (AUC0–∞) and the peak plasma concentration (Cmax) were significantly smaller (0.572-fold) and lower (0.412-fold), respectively, than those in the control rats. These values were recovered by co-administration of bile salt (0.831- and 0.828-fold for AUC0–∞ and Cmax compared with the control, respectively). Thus, the decreased absorption of roxithromycin in BDC rats could be due to a depletion of bile. The solubility of roxithromycin was 3.09-fold increased at 30 mm of sodium taurocholate. The oral dosage regimen of roxithromycin could be changed in patients with bile deficiency or when the drug is administered to individuals on a high-fat diet, if the present rat data can be extrapolated to humans. Copyright © 2013 John Wiley & Sons, Ltd.

This study focuses on the identification of ignition characteristics and carbon discharge resulting from combustion of surface fuels vulnerable to forest fire. Four withered surface fuels, including dead leaves and cones of Pinus densiflora, dead leaves of Quercus variabilis, and Castenea crenata burs; and six biofuel herbs, including Agsstache rugosa, Oplismenus undulatifolius, Pueraria thunbergiana, Cirsium japonicum var. ussuriense, Festuca ovina L., and Osmundaceae were selected for analysis. Also, monthly carbon emissions (Jun. - Oct. 2008) from Festuca ovina were analyzed. As a result of tests, it was confirmed that dead leaves and cones of P. densiflora and C. crenata burs were instantly ignited with flame, which lasted quite a while. The total CO2 and CO emissions from the 10 different kinds of surface fuels analyzed on this study were 28-98 g and 0.76-4.08 g per 50 g of each fuel, respectively, indicating that the amount of carbon emissions vary depending on the type of fuel. The results also demonstrated that there is a great difference between withered fuels and biofuels in terms of carbon emissions. More specifically, the four withered types of fuels, compared to the six biofuel herbs, were found to emit more CO2 and CO. In particular, dead cones of P. densiflora emitted more carbon dioxide (CO2) and carbon monoxide (CO) than the rest of the surface fuels. Also, the carbon emissions were found high during the period of from August to September. Consequently, in the case of a forest fire, dead cones and leaves of P. densiflora are expected to emit up to 3.5 times more CO2 and CO than the other surface fuels. The area covered with dead leaves and pine cones is thought to have a high risk of ignition, high fire inten- sity because of relatively long lasting flame, and rapid fire spread. Herbs and living fuels with high moisture content are expected to elucidate the course of fire in that they produce large amount of combustion prod- ucts such as smoke and carbon discharge resulting from nonflame-ignition.

Purpose: The purpose of this study was to determine the effect of Tai Chi exercise program (Sun style 12 forms) on anxiety, powerlessness, self-esteem in community-dwelling elderly women. Methods: With a quasi-experimental design, a nonequivalent control group pretest-post test was used. Elderly women who agreed to participate in the study were assigned into an experimental group (n=23), or a control group (n=23). The experimental group participated in Tai Chi exercise program for 50 minutes per session, 2 times a week for 11 weeks. Tai Chi exercise program consisted of 10 minutes for warm-up, 35 minutes for main session, and 5 minutes for cooling down exercises. Anxiety, powerlessness, and self-esteem were measured with questionnaires to evaluate the effect of Tai Chi exercise program. The data were analyzed by using Chi-square test, Fisher's exact test, and Mann-Whitney test by a SPSS WIN 12.0 program. Results: The experimental group showed significant improvement for self-esteem (z=-3.130, p=.002), powerlessness(z=-3.267, p=.001), and anxiety (z=-2.932, p=.003) when compared to control group, Conclusions: Tai chi exercise program may be an effective nursing intervention to improve self-esteem and to reduce powerlessness and anxiety in community-dwelling elderly women.

Graphene's single atomic layer of sp(2) carbon has recently garnered much attention for its potential use in electronic applications. Here, we report a memory application for graphene, which we call graphene flash memory (GFM). GFM has the potential to exceed the performance of current flash memory technology by utilizing the intrinsic properties of graphene, such as high density of states, high work function, and low dimensionality. To this end, we have grown large-area graphene sheets by chemical vapor deposition and integrated them into a floating gate structure. GFM displays a wide memory window of ∼6 V at significantly low program/erase voltages of ±7 V. GFM also shows a long retention time of more than 10 years at room temperature. Additionally, simulations suggest that GFM suffers very little from cell-to-cell interference, potentially enabling scaling down far beyond current state-of-the-art flash memory devices.

A low-profile inverted-L antenna with one folding at 20−90 MHz bands for aircraft applications is presented. The designed antenna is installed on the top of the vertical stabiliser of an aircraft to increase the gain at 20 MHz using the ground edge current and to reduce air drag. The gain of the designed antenna is increased by 3 dB at 20 MHz, and the antenna length is reduced by 41% compared with the reference antenna, which is a folded monopole antenna coupled with a parasitic element. The measured 3 dB return loss bandwidth is 342.9 MHz (51.5%) and the peak gain at 200 MHz is −11.5 dBi for the 1/10 scaled sub-model. In addition, the omnidirectional radiation pattern was observed in the operating frequency.

We present an approach to mass produce high-quality graphene on insulator substrate. Ni dots with single or few grains were achieved by annealing. Electron backscattered diffraction indicated that almost all of the Ni dots had (111) surface that is parallel to the substrate. Single-layer graphene with good crystalline quality has been grown on Ni dots. The patterned graphene films were transferred to insulating substrates by wafer bonding and etch back technique, which resulted in zero misalignment, low contamination, and high yield (>90%). Graphene-based field-effect transistors with self-aligned gate were fabricated with this method, which demonstrate the potential of this method as a candidate for mass production of graphene transistors.

Purpose: The purpose of this study was to identify the effect of Tai Chi exercise on loneliness, sleep pattern, and instrumental activities of daily living in elderly women. Methods: A quasi-experimental design, a nonequivalent control group pretest-posttest was used. Elderly women who agreed to participated in the study were assigned into an experimental group (n

We present a critical review of graphene for field-effect transistor (FET) application. By using graphene sheet as the channel material, the new FET is expected offer significant advantages in certain aspects over and above that of the present Si-based counterpart. There are many challenges as well since the overall operating principle of the FET channel is different. We present our perspective with regard to these challenges. And we also demonstrate the ability of synthesizing monolayer graphene on Cu foils and placing it on insulator surfaces.

Purpose The present retrospective study evaluated various implant surface factors associated with Bicon implant survival for single-tooth restoration in the healthy individual. Patients and Methods A retrospective cohort study design was used. A total of 613 Bicon (Bicon System, Boston, MA) implants (272 patients) were included. Because the use of hydroxyapatite (HA) coating has been controversial, the surface type was chosen according to the patient's preference. A total of 308 HA-coated implants and 305 titanium plasma-sprayed (TPS) implants were used. The macroanatomy of both implant types was identical. Patients who had systemic disease, poor quality bone, or removable prosthetics were excluded from the present study. A chart review was conducted to record age, gender, implant diameter, implant length, installation depth, installation location, and the use of bone grafting. Implant failure was recorded, and the data were analyzed using the χ2 test and logistic regression analysis. Results The installation depth was an important prognostic factor in the HA-coated implants. The failure rate for the HA-coated implants installed at margin level and 2 mm below level was 10.29% and 3.01%, respectively (χ2 = 6.035, P = .014). The implant length was an important prognostic factor for the TPS-treated implants. The failure rate recorded for the TPS-treated implants installed with a length of less than 10 mm and 10 mm or longer was 15.46% and 2.40%, respectively (χ2 = 18.414, P Conclusion Many factors can influence the failure rate of TPS and HA-coated Bicon implants. Among these, installation depth played an especially significant role in the success of HA-coated Bicon implants in the present study.

We report the fabrication and characterization of a planar resonant tunneling transistor (PRTT) using a GaAs/AlGaAs heterostructure wafer. Our PRTT operates as an enhancement-mode device, and shows the negative differential resistance (NDR) modulated with the gate bias in an extremely wide range (from the fully depleted dot to the dot in a single-electron transistor regime). This NDR spectrum represents a full, gate-bias-modulated evolution of the 0-D states in a quantum dot. Our data are also consistent with the ground (E 1) and the first excited state (E 2) of the Fock-Darwin states.

We present the results of a systematic study of chemical vapor deposition of graphene on silicon substrates. The silicon substrate is covered with SiO 2 and capped with an electron-beam evaporator deposited nickel film, which serves as the catalyst for carbon precursor decomposition. Methane is used as the carbon precursor. Three key parameters of CVD growths, the growth temperature, time, and the post-growth cooling rate are studied and the optimized combination of the three allowed for the reproducible fabrication of single layer graphene of larger than 100 μm 2 covering more than 50% of the surface of 1-in. diameter Si wafers. We further demonstrate the transfer of CVD graphene onto SiO 2 /Si surfaces with higher than 95% success rate. Our result together with those reported by other research groups shows real promise of the integration of carbon electronics with silicon integrated circuit technology.

Strain potentials, potential profiles, and electronic subband energies of InAs/GaAs coupled double quantum dots (QDs) were calculated by using a finite-difference method (FDM) taking into account shape-based strain effects. The shape of the InAs/GaAs coupled double QDs on the basis of the transmission electron microscopy image was modeled to be a truncated hemi-ellipsoid. The interband transition energies from the ground electronic subband to the ground heavy-hole band (E1-HH1) in the InAs/GaAs coupled double QDs, as determined from the FDM calculations taking into account strain effects, were in qualitatively reasonable agreement with the excitonic peaks corresponding to the (E1-HH1) interband transition energies at several temperatures, as determined from the temperature-dependent photoluminescence spectra. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Strained potential profiles and electronic subband energies of InAs/GaAs coupled double quantum dots (DQDs) were calculated by using a three-dimensional finite-difference method (FDM) taking into account shape-based strain and nonparabolic effects. The interband transition energies from the ground electronic subband to the ground heavy-hole band (E 1 -HH 1 ) in the InAs/GaAs DQDs, as determined from the FDM calculations taking into account strain and nonparabolic effects, were in reasonable agreement with the experimental peaks corresponding to the (E 1 -HH 1 ) interband transition energies at several temperatures, as determined from the temperature-dependent photoluminescence spectra.

Capacitance–voltage ( C – V ) and electrostatic force microscopy (EFM) measurements on Si nanocrystals (Si-NCs) formed by using the sonochemical method were carried out to investigate the charging effects of the Si-NCs. Transmission electron microscopy images and atomic force microscopy images showed that the Si-NCs were created inside the SiO 2 layer. The C – V curve and the EFM image showed that the Si-NCs embedded in the SiO 2 layer experienced charging effects. The macroscopic surface charge density determined from the C – V curve was in reasonable agreement with the microscopic local value obtained from the EFM image. The present results indicate that the EFM technique might provide a promising method for investigating charging effects in various kinds of nanocrystals embedded in the insulating layer.

Two types of secondary amino alcohols were successfully resolved on a liquid chromatographic chiral stationary phase based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid. The secondary amino alcohols containing a secondary amino group connected directly to the stereogenic center were resolved much better than those containing a hydroxyl group attached directly to the stereogenic center. In addition, the dependence of the separation factor (α) on column temperature was exactly opposite for the two different types of secondary amino alcohols. From the thermodynamic calculations based on Van’t Hoff plots, we conclude that the enantioselectivity for the resolution of the secondary amino alcohols containing a secondary amino group connected directly to the stereogenic center is enthalpically controlled while that for the resolution of the secondary amino alcohols containing a hydroxyl group attached directly to the stereogenic center is entropically controlled.

The objective of this study was to identify CYP3A4 variants in Koreans and to characterize their functional consequences in vitro and in vivo. Four single nucleotide polymorphisms were identified in 50 Koreans by direct DNA sequencing. In an additional genotyping using 248 subjects, CYP3A4(*)18 was confirmed as the most frequent coding variant in Koreans at 1.7%, and its frequency was similar to that of Asians, suggesting that CYP3A4(*)18 would be the highest coding variant in Asians. The recombinant CYP3A4.18 protein prepared in baculovirus expression system showed 67.4% lower Vmax and 1.8-fold higher K(m) for midazolam 1'-hydroxylation compared with the wild type. The mean values of Cmax and area under the concentration curve (AUC) in the CYP3A4(*)1/(*)18 and CYP3A5(*)1/(*)3 subjects (n = 8) were 63% and 32% higher than in CYP3A4(*)1/(*)1 and CYP3A5(*)1/(*)3 carriers (n = 8), respectively. Although the in vitro assay exhibited a significant reduction of the enzyme activity for midazolam, the in vivo differences associated with the CYP3A4(*)1/(*)18 tend to be low (P < 0.07 in Cmax and P < 0.09 in AUC). In summary, the heterozygous CYP3A4(*)1/(*)18 does not appear to cause a significant change of midazolam disposition in vivo; however, the clinical relevance of CYP3A4(*)18/(*)18 remains to be evaluated.

We report transport measurements through an in-plane-gate quantum dot transistor (IPGQDT). Our IPGQDT has etched trench isolation between the two-dimensional electron gas QD and IPGs, and it operates in enhancement mode. At relatively small IPG biases, we observe negative differential resistance (NDR) in the current–voltage characteristics. The position of the NDR peak is controlled systematically by the change of the IPG bias. At large biases, the IPGQDT exhibits single-electron tunneling. All of these transport data are not sample specific and consistent with the size of the QD.