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The new Si epitaxial (epi) defects not seen in scanning electron microscope (SEM) measurements were investigated. Morphologies of these defects were measured by atomic force microscope (AFM) but source of defect was not found in transmission electron microscope (TEM) measurements. In order to find the origin of the invisible defect, we observed the morphological changes of the various substrate defects after epi growth process. Most of the defects were removed during hydrogen (H 2 ) baking and hydrogen chloride (HCl) etching steps, but some particles survived. Among the survived defects, it was confirmed that the non-metallic particles having 200 nm or more were the origin of the invisible epi defects.

Objective Diabetes is characterized by pancreatic β-cell dedifferentiation. Dedifferentiating β cells inappropriately metabolize lipids over carbohydrates and exhibit impaired mitochondrial oxidative phosphorylation. However, the mechanism linking the β-cell's response to an adverse metabolic environment with impaired mitochondrial function remains unclear. Methods Here we report that the oxidoreductase cytochrome b5 reductase 3 (Cyb5r3) links FoxO1 signaling to β-cell stimulus/secretion coupling by regulating mitochondrial function, reactive oxygen species generation, and nicotinamide actin dysfunction (NAD)/reduced nicotinamide actin dysfunction (NADH) ratios. Results The expression of Cyb5r3 is decreased in FoxO1-deficient β cells. Mice with β-cell-specific deletion of Cyb5r3 have impaired insulin secretion, resulting in glucose intolerance and diet-induced hyperglycemia. Cyb5r3-deficient β cells have a blunted respiratory response to glucose and display extensive mitochondrial and secretory granule abnormalities, consistent with altered differentiation. Moreover, FoxO1 is unable to maintain expression of key differentiation markers in Cyb5r3-deficient β cells, suggesting that Cyb5r3 is required for FoxO1-dependent lineage stability. Conclusions The findings highlight a pathway linking FoxO1 to mitochondrial dysfunction that can mediate β-cell failure., Highlights • Cyb5r3 is a FoxO1 target in β-cells. • Cyb5r3 ablation impairs respiration and stimulus/secretion coupling in β-cells. • β-cell-specific deletion of Cyb5r3 impairs insulin secretion and causes glucose intolerance. • Cyb5r3-deficient β-cells display mitochondrial and secretory granule abnormalities. • Cyb5r3-deficient β-cells lack key differentiation markers.

Internal gettering (IG) of metallic impurities (MI) in Czochralski silicon (CZ-Si) is one of the key techniques in modern microelectronic engineering to manufacture high-performance devices with high process yield. Various silicon substrates such as EPI wafers with heavily boron-doped substrates, ion-implanted wafers, and rapid-thermal annealing (RTA) treated wafers have been used to enhance IG ability [1-2] and retain denuded zone (DZ) for the active area of devices. Especially, RTA-treatment is an easy way to form IG and DZ simultaneously with a rapid heat process that injects the intrinsic point defects, mainly vacancies, into the bulk. However, it was reported that vacancy clusters, or ‘nano voids’ whose size was less than 50nm [2-3] could be formed in the near-surface region after RTA process via vacancy self-trapping [4], which can possibly degrade the performance and yield of device. In this study, we investigated the effect of RTA treatment on the gate oxide reliability and their relation to the crystal nature, i.e., as-grown point defect distribution in silicon wafers. As shown in Fig. 1 a), we performed the Cu-contamination method [5] on the prepared samples to verify the crystal nature of each sample. After that, we separated the samples into two groups whether they treated by RTA or not, and carried out time-zero dielectric breakdown (TZDB) reliability tests on the patterned poly-Si/oxide/Semiconductor capacitors with the gate oxide thickness of 10 nm. As shown in Fig. 1 b), distribution of TZDB failed cell on the wafer was closely related to the crystal nature. Moreover, it was revealed that a vacancy-dominant region tends to have lower breakdown field than an interstitial-dominant region. These phenomena were only found in RTA-treated wafers and entire fail rate was drastically increases when RTA effect was combined with vacancy-dominated region, which was shown in Fig. 1 b). We assumed that as-grown vacancies contained in the vacancy-dominated region tend to enhance the supersaturation of vacancy beneath the oxide-semiconductor interface, so the formation of nano voids was accelerated and the breakdown field was lowered due to the presence of such defects. A detailed mechanism of the experimental result will be discussed. Figure 1. a) Crystal nature measured by Cu contamination method and b) TZDB frequency with or without RTP References 1. Jea-Gun Park, Gon-Sub Lee, Jin-Seo Lee, Kazunari Kurita, Hisashi Furuya, Mater. Sci. Eng., B, 134, 249 (2006). 2. G.Kissinger, D.Kot, W.Häckl, ECS transactions, 33(11), 113 (2010). 3. Thomas A. Frewen, Talid Sinno, Appl. Phy. Lett, 89, 191903 (2006). 4. M.Gao, X.F.Duan, L.-M.Peng, Appl. Phy. Lett., 73, 2311 (1998). 5. Sang-Wook Wee, Sung-Wook Lee, Ki-Man Bae, and Kwand-Salk Kim, U. S. Patent 7,901,132. Figure 1

To evaluate the optimum operating conditions for the micronization of cyclotrimethylenetrinitramine (RDX) crystals using the Supercritical Anti-Solvent (SAS) process, a predictive approach incorporating the Hansen solubility parameters and jet behavior analysis has been suggested. The crystals were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction, and particle size analysis. Near the mixture critical point, the jet behavior and corresponding FE-SEM images of the particles indicated that agglomerations were present at pressures below that of the mixture critical point. On the other hand, for conditions above the mixture critical point, the relative energy difference values were calculated using the Hansen solubility parameters to compare the effectiveness of the carbon dioxide and acetone mixture as an antisolvent. Our analysis was supported by the micronized RDX particles with a lesser degree of agglomeration at the temperature of 65 °C, the pressure of 11 MPa, and the concentration of 4.24 wt%. These results were attributed to the higher pressure than the mixture critical point and a relatively high value of RED (3.74).

The thermal behavior of silicon nanoparticles (Si NPs) was investigated for the preparation of silicon thin film using a solution process. TEM analysis of Si NPs, synthesized by inductively coupled plasma, revealed that the micro-structure of the Si NPs was amorphous and that the Si NPs had melted and merged at a comparatively low temperature (~750 °C) considering bulk melting temperature of silicon (1414 °C). A silicon ink solution was prepared by dispersing amorphous Si NPs in propylene glycol (PG). It was then coated onto a silicon wafer and a quartz plate to form a thin film. These films were annealed in a vacuum or in an N₂ environment to increase their film density. N2 annealing at 800 °C and 1000 °C induced the crystallization of the amorphous thin film. An elemental analysis by the SIMS depth profile showed that N₂annealing at 1000 °C for 180 min drastically reduced the concentrations of carbon and oxygen inside the silicon thin film. These results indicate that silicon ink prepared using amorphous Si NPs in PG can serve as a proper means of preparing silicon thin film via solution process.

Practical difficulty in the HDDR (hydrogenation disproportionation desorption recombination) processing of Nd-Fe-B-type alloy is a poor reproducibility of coercivity of the HDDR-treated material. In an attempt to improve the reproducibility of coercivity of the HDDR-treated Nd12.5Fe80.6B6.4Ga0.3Nb0.2 alloy, the hydrogen decrepitation was carefully controlled so as to induce more extensive micro-cracks in the particle. Prior to the hydrogenation and disproportionation reaction of HDDR processing, an additional hydrogen degassing was carried out at an elevated temperature of 600 C under vacuum for the previously hydrogen decrepitated particle. During the additional hydrogen degassing the lattice of hydrogen absorbed Nd2Fe14B phase was further shrunken, hence more microcracks were introduced in the particle due to its brittle nature. Particles with more micro-cracks had more homogeneous hydrogen absorption and desorption reaction during the HDDR-treatment. The improved reproducibility of coercivity of the HDDR-treated material was attributed to the improved homogeneity of the HDDR reactions due to the presence of more micro-cracks.

Rice bran (RB), a by-product obtained during polishing of un-milled rice, contains a large quantity of essential nutrients such as minerals, vitamins, fiber, amino acids, and antioxidants. In this study, the anti-obesity effects of stabilized RB addition as a food material in a diet-induced obese animal model were investigated. For the analysis, a total of 32 mice were randomly divided into four groups: normal diet group (ND, n=8), high-fat diet group (HFD, n=8), 20% RB added high fat diet group (HFRB20, n=8), and 40% RB added high fat diet group (HFRB40, n=8). The animals were sacrificed after 7 weeks. Body weight gain, various adipose tissue weights, blood glucose concentration, and serum leptin level of the HFRB40 group were found to be significantly lower than those of the HFD group. Moreover, antioxidant enzyme activity of the HFRB40 group was significantly higher than that of the HFD group. However, the HFRB20 group did not show significantly different values. The results of this study show that RB (40%) addition reduces body weight gain and improves obesity-related parameters. These results suggest RB could be considered as a functional additive material for the manufacture of anti-obesity products, and 40% RB addition would be the physiologically effective level.

In the present study, we developed an official individual analytical method for cymoxanil usingHPLC/UVD, respectively in different representative crops. Individual analytical methods for these pesticidesare not included in the Korea food code. The samples were extracted with acetonitrile, concentrated andpartitioned with dichloromethane and saturated sodium chloride solution. For cymoxanil, extracts wereconcentrated and clean-up through silica gel column chromatography with dicloromethane/acetone (60/40 v/v)and subjected to instrumental analysis. The limit of detection (LOD) for cymoxanil were 0.1 ng and 1 ngrespectively and limit of quantitation (LOQ) were 0.02 mg/kg. Recoveries for cymoxail ranged from 79.6~107.6% respectively, at fortification level of 0.02 mg/kg (LOQ), 0.2 mg/kg (10 LOQ) and 1.0 mg/kg(50 LOQ) and the coefficient of variation (CV) was less than 10%, regardless of sample types. These resultswere further confirmed with LC/MS. The proposed simultaneous analysis method is reproducible andsensitive enough to determine the residues of cymoxanil in the agricultural commodities. According to thevalidation data and performance characteristics and high sample throughput, the proposed method is suitablefor routine application.Key words analytical method, Cymoxanil, HPLC/UVD, LC/MS

A dual-function nano-system for synergistic photodynamic therapy (PDT) and photothermal therapy (PTT) was constructed. Gold nanorods (GNRs) as a PTT agent and chlorin e6 (Ce6) as a photosensitizer (PS) for PDT were loaded into a chitosan-functionalized, Pluronic-based nanogel that was proven to be an efficient delivery vehicle to the tumor site in vivo. Previously reported combined therapy systems relied on quenching and de-quenching of PS for PDT upon thermo-impact of PTT, thus only PTT followed by PDT procedure was possible. In contrast, the present dual-acting system has no quenching between PS and GNRs by preventing direct contact and self-aggregation of photo-sensitizers, allowing independent PDT or PTT procedure. In both in vitro cell culture and in vivo tumor-bearing mice experiments, a remarkably enhanced tumor ablation compared to the treatment of PDT or PTT only was observed by the treatment of PDT followed by PTT, but not significantly by the treatment of PTT followed by PDT. Thus, the present study demonstrated the synergistic effect of PDT and PTT in a sequence-dependent manner, and our system is a promising dual function nano system to achieve the enhanced phototherapy in vivo.

Validated analytical methods for isopyrazam are meager or lacking. In the present study, a singleresidual analytical method was developed for isopyrazam in selected commodities. Isopyrazam was analyzedin brown rice, soybean, green pepper, mandarin, cucumber, and Korean melon. We tried different solventsand methods through extraction, partition and purification steps to obtain best analytical results. Forisopyrazam samples were extracted with acetonitrile, concentrated and partitioned with n-hexane, clean-upusing florisil with n-hexane/ethylacetate (70/30) and analyzed with HPLC/UVD. The limit of quantitation(LOQ) for isopyrazam was 1.0 ng (S/N > 10) and method LOQ (MLOQ) was 0.04 mg kg Š 1 . Recovery rangedthrough 81.0~105.3% (syn-isomer) and 80.8~105.6% (anti-isomer) at fortification level of 0.04 (MLOQ), 0.4(10 × MLOQ), and 2.0 (50 × MLOQ). The coefficient of variation (CV) for isopyrazam was less than 10%regardless of sample types. These results were further confirmed with LC/MS, respectively. The proposedmethod is highly reproducible and sensitive and is suitable for routine analysis.Key words Agricultural products, Isopyrazam, Limit of quantitation, Pesticide, Single residual analytical method

System on Chip (SoC) and System in Package (SiP) technologies provide a path for continued improvement in performance, power, cost and size at the system level without relying upon conventional CMOS scaling alone. SiP technology is rapidly evolved from specialty technology used in a narrow set of applications to a high volume technology with wide ranging impact on electronics markets. The broadest adoption of SiP to date has been for stacked memory/logic devices and small modules (used to integrate mixed signal devices and passives) for mobile phone applications. Both these applications are driving high volume and very cost competitive market with a broad base of suppliers has developed. The Multi-Chip Packaging (MCP) technique has been increasing die stacking numbers to allow increasing memory capacity. According to ITRS roadmap, The progression of wafer thinning will reach 8μm thickness of thinned wafer and stacking of multiple die up to 14 stacks by the year 2015. This will pose a number of technical challenges for wafer thinning processes and starting material.[1] Semiconductor companies have studied gettering techniques until today for eliminating metallic contamination induced during device processes. Metallic contamination is one of the main failure sources in the device process. Thus, many researchers have been studying various gettering techniques by means of improving semiconductor device yields. Gettering can be categorized as either internal gettering or external gettering. In particular, internal gettering is easily achieved in a silicon wafer through the presence of oxygen precipitate (i.e. BMD) and heavily boron dope. However, state-of–the-art MCP process achieved and required novel grinding performance as thin as silicon substrate DZ region. As a result, traditional intrinsic or internal gettering should be studied to gettering ability effectiveness for extremely thinned silicon substrate. In order to understand gettering ability of MCP thinning processed wafer, the gettering test involves two type wafers as CZ polished and epitaxial wafer with splitting resistivity and dopant type which conventionally used to memory and logic device. Table 1 showed to the detailed sample types and their properties. The gettering test of thinning processed wafer was performed to below procedure. First, MCP thinning wafers were fabricated to three MCP thinning condition as total wafer thickness of 30um, 50um, and 100um after device heat simulation treatment. Afterward, the thinned samples were intentionally contaminated by Cu and Ni on backside of thinned wafer. Subsequently contaminated thinned wafers were applied to high temperature diffusion heat treatment on 950C about 30min. Cu and Ni diffused from the surface of a backside to surface of front surface or captured by the gettering sinks in the bulk during diffusion heat treatment. Finally, gettering ability analysis was evaluated by front and backside Cu, Ni concentration measurement. Gettering efficiency can be calculated to below equation.

Brain-targeted delivery of drug or imaging agent is hard to achieve efficiently due to the infiltrative nature of the blood-brain barrier (BBB). Moreover, delivery of therapeutic proteins to brain tissue is further limited by the size and physic-chemical properties of proteins. In this work, we developed a chitosan-conjugated Pluronic-based nano-carrier with a specific target peptide for the brain (rabies virus glycoprotein; RVG29) and applied for the protein delivery to the brain. The in-vivo brain accumulation of the nano-carrier in mice followed i.v injection was optically monitored with Cy5.5-conjugation to the nano-carrier, and the result showed that the Pluronic-based nano-carrier conjugated with both chitosan and the peptide was very efficient for the accumulation in brain tissue and was remarkably better than the nano-carrier conjugated with the peptide only. β-galactosidase, a model protein, was also delivered and accumulated efficiently in the brain by loading in the nano-carrier, analyzed by the bio-distribution of β-galactosidase. The delivered protein in the brain also maintained its bioactivity. Therefore, RVG29- and chitosan-conjugated Pluronic-based nano-carrier could be potentially useful for the diagnosis and therapy of brain diseases.

This study was conducted to investigate the physiological activities of saccharified cherry tomato gruel containing different levels(0, 15, 30, and 45%) of cherry tomato puree. The total phenolic compound and flavonoids contents of saccharified cherry tomato gruel with cherry tomato puree were 1.73-5.09 mg/g and 0.28-7.01 mg/g, respectively. DPPH radical scavenging activities of saccharified cherry tomato gruel with cherry tomato puree were 8.67-92.58%, respectively. The ABTS radical scavenging activities of saccharified cherry tomato gruel with cherry tomato puree ranged from 6.02 to 61.59%. The ACE inhibitory activity of cherry tomato rice gruel increased with cherry tomato puree showed a range of 38.85-62.15%, respectively. With increasing additions of cherry tomato puree, the total phenolic compound and flavonoid contents, DPPH and ABTS radical scavenging activities and, ACE inhibitory activities were increased significantly (p

This study investigated the quality characteristics of saccharified minor cereal gruel prepared with different grain kojis (rice, buckwheat, sorghum, adlay, and Italian millet koji). The moisture, crude protein, crude lipid, and crude ash contents of raw materials showed ranges of 11.12 - 12.85; 5.81-16.24; 0.56 - 4.36, and 0.28 - 1.93%, respectively. The crude protein, crude lipid, and crude ash contents of the samples showed ranges of 1.64 to 2.44; 0.08 to 0.28, and 0.09 to 0.18%, respectively. The pH, L, a, and b values ranged from 6.11- 6.43; 58.72 - 65.96; 2.92 - 5.76, and 7.81- 9.42, respectively. The viscosities of saccharified minor cereal gruel prepared with different grain kojis were significantly (p

The new metrology, Advanced Poly-silicon Ultra-Trace Profiling (APUTP), was developed for measuring bulk Cu and Ni in heavily boron-doped silicon wafers. A Ni recovery yield of 98.8% and a Cu recovery yield of 96.0% were achieved by optimizing the vapor phase etching and the wafer surface scanning conditions, following capture of Cu and Ni by the poly-silicon layer. A lower limit of detection (LOD) than previous techniques could be achieved using the mixture vapor etching method. This method can be used to indicate the amount of Cu and Ni resulting from bulk contamination in heavily boron-doped silicon wafers during wafer manufacturing. It was found that a higher degree of bulk Ni contamination arose during alkaline etching of heavily boron-doped silicon wafers compared with lightly boron-doped silicon wafers. In addition, it was proven that bulk Cu contamination was easily introduced in the heavily boron-doped silicon wafer by polishing the wafer with a slurry containing Cu in the presence of amine additives.

The clinical significance of ADAMTS13 activity for response to treatment, mortality rate, recurrence, and prognosis is unclear. Therefore, we investigated the characteristics of severe ADAMTS13 deficiency and evaluated its prognostic features in Thrombotic thrombocytopenic purpura (TTP). The Korean TTP Registry includes 66 patients from 13 teaching hospitals in Korea who received the diagnosis of TTP from January 2005 to December 2008. Blood samples obtained upon admission were sent for ADAMTS13 analysis (multimer analysis by sodium dodecyl sulfate electrophoresis) to a central laboratory along with patient clinical information. Patients with severe ADAMTS13 deficiency had lower serum creatinine levels (P = 0.001) than patients with non-severe ADAMTS13 deficiency. Although severe ADAMTS13 deficiency was associated with better response rate (75 vs. 53%, P = 0.145), remission rate (81 vs. 61%, P = 0.209), and mortality rate (19 vs. 31%, P = 0.508) than non-severe ADAMTS13 deficiency, treatment outcomes did not differ significantly between groups. After adjusting for clinical and laboratory features, multivariate analysis did not reveal any independent risk factors for TTP-associated mortality. Patients with severe ADAMTS13 deficiency had lower serum creatinine levels at presentation, but severe ADAMTS13 activity deficiency at TTP diagnosis does not appear to have prognostic significance.

Pluronic-based nano-carriers including bare forms that were composed of Pluronic F 68(NC(PF 68)) or Pluronic F 127(NC(PF 127)), and chitosan-conjugated forms (Chito-NC(PF 68) or Chito-NC(PF 127)) were prepared by photo-polymerizing two kinds of diacrylated Pluronic (F 68 and F 127) and acrylated chitosan to investigate the effect of chitosan conjugation and their physicochemical characteristics (size and hydrophilicity) of Pluronic-based nano-carriers on the tumor targeting efficiency. All of the nano-carriers were stable in serum-containing media without forming any aggregation and did not show any acute cytotoxicity to both normal (NIH3T3 fibroblast) and tumor (SCC7) cells. Chitosan conjugation did not change their sizes or thermo-sensitive properties of the nano-carriers, but significantly increased their in-vitro cellular uptake compared to the corresponding bare forms. The in-vivo tumor accumulation of these nano-carriers was optically monitored by using Cy5.5-attached nano-carriers in SCC7 tumor-bearing mice. For all cases, local accumulation of the injected nano-carriers in liver was not dominant compared to the tumor site, demonstrating good tumor targeting efficacy of the Pluronic-based nano-carriers. Among different samples, chitosan-conjugated nano-carriers showed much better tumor accumulation than bare forms, and mostly remained up to 72h, implying prolonged blood circulation and more efficient tumor accumulation. Between Chito-NC(PF 68) and Chito-NC(PF 127), Chito-NC(PF 68) showed a little better tumor accumulation and retention, suggesting the difference in Pluronic, thus difference in hydrophilicity and the size of the nano-carriers also might affect the tumor targeting. In contrast, bare nano-carriers were initially accumulated well in tumor, but they were excreted from the tumor site relatively rapidly. Therefore, chitosan-functionalization was very effective for improving the tumor targeting efficacy of Pluronic-based nano-carriers.

Since Mizoroki and Heck’s original work, numerous improve-ments and modifications have been reported for the catalytic system. However, most catalytic systems have focused on the development of suitable ligand systems that take into consi-deration the steric and electronic effects. Among them, sterically bulky phosphines

A simple method of depositing Pd nanoparticles onto carbon nanotubes (CNTs) as catalyst supports is devised for C C bond forming reactions. Thiol groups were utilized as linkers to secure the Pd nanoparticles without agglomeration. The samples were characterized by TEM, XPS and Raman spectroscopy. The prepared CNT-Pd nanocomposites effectively promoted the formation of C C bonds at a low Pd content (∼2.0%) and in the absence of any ligand. This result indicates that surface thiolation is an effective way to obtain highly dispersed metal nanoparticles on the surface of CNTs and markedly improves their catalytic activity.

In this study, we demonstrated the surface reaction in a LiCoO2/Li cell under high voltage condition and characterization of the composition and properties of electrode–electrolyte interface by 2D correlation analysis. 2D Raman correlation spectra revealed that the extraction of Li+ leads to the formation of surface components including Li2O and Co3O4 and structural distortion in hexagonal LiCoO2 structure.

OBJECTIVE The adipocyte-derived secretory protein adiponectin has been widely studied and shown to have potent insulin-sensitizing, antiapoptotic, and anti-inflammatory properties. While its biosynthesis is well understood, its fate, once in circulation, is less well established. RESEARCH DESIGN AND METHODS Here, we examine the half-life of adiponectin in circulation by tracking fluorescently labeled recombinant adiponectin in the circulation, following it to its final destination in the hepatocyte. RESULTS Despite its abundant presence in plasma, adiponectin is cleared rapidly with a half-life of ∼75 min. A more bioactive version carrying a mutation at cysteine 39 is cleared within minutes. Even though steady-state levels of adiponectin differ between male and female mice, we failed to detect any differences in clearance rates, suggesting that differences in plasma are mostly due to differential production rates. In a metabolically challenged state (high-fat diet exposure or in an ob/ob background), adiponectin levels are reduced in plasma and clearance is significantly prolonged, reflecting a dramatic drop in adiponectin production levels. CONCLUSIONS Combined, these results show a surprisingly rapid turnover of adiponectin with multiple fat pads contributing to the plasma levels of adiponectin and clearance mediated primarily by the liver. It is surprising that despite high-level production and rapid clearance, plasma levels of adiponectin remain remarkably constant.

Low level impurities often reside in cosmetic products. The aim of the present study was to estimate the human exposure to chromium from cosmetic products purchased at a local market in South Korea, and to assess the risk on public health. Hexavalent chromium is an impurity substance that contaminates cosmetic products during manufacture. The potential for chromium to induce and elicit allergic contact dermatitis, as well as the degree of chromium exposure from cosmetic products, were assessed. Chromium exposure was estimated using the chromium concentrations found in cosmetic samples taken from the local market along with the expected user pattern data that was taken from the literature. Of the cosmetics we tested and available for purchase on the Korean market, seven had chromium contents above the detection limit of 0.1 ppm (0.1 microg/mL), ranging from 0.2 to 3.15 ppm. In risk assessment, scientifically defensible dose-response relationships must be established for the end points of concern. In the case of chromium contaminated cosmetic products, this includes conducting dose-response assessments for allergic contact dermatitis following dermal exposure. This dose-response information can then be integrated with site-specific exposure assessments to regulate consumer safety by use of these products. We found that dermal exposure to chromium concentrations ranging from 0.0002 to 0.003 microg/cm(2) does not appear to cause concern for eliciting allergic contact dermatitis.

Vertically oriented multilayers composed of two saturated phospholipids, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphoserine (DPPS), were deposited on silicon. X-ray reflectivity was used to investigate the structures of the variously mixed phospholipid multilayers as a function of composition. Then, the phase stability was investigated at various annealing temperatures under humid conditions. The results indicated that the lipid spacing of the mixed phospholipid multilayers varied systematically as a function of the DPPC/DPPS ratio and that no macroscopic phase separation occurred during the annealing process under both dry and humid conditions.

Organic contaminants are particularly more difficult to classify or control than the others such as metal impurities or particulate matters because of their ubiquitous contamination from all sources of manufacturing facilities. Especially, bis(2-ethylhexyl) phthalate (DOP) used as plasticizer is shown to be an indicator of organic contamination because of its nonor low volatility and strong adsorption onto the silicon wafer. 2 We used DOP for quantitatively contaminating the wafer surface and studied its effects. Contaminated DOP spots were almost completely removed from the wafer surface during thermal oxidation of silicon. However, a very small portion of the spots remained on the surface and captured in the interface between polysilicon and silicon oxide layers during the polysilicon deposition process as schematically shown in Fig. 1. Fig. 2 shows the results of current vs. electric field (I/EF) measurements after the gate oxidation processing on a wafer. In the reference sample, large leakage currents of about 1x10 A/cm are observed only at the electric field of higher than 12 MV/cm and the increases in current begin to level off beyond about 7 MV/cm. On the other hand, the threshold EF values, at which currents begin to increase, shift to increasingly smaller values and rapid increases in current upon small increase in the electric field start to show up as the currents get close to the saturated values when the initial DOP concentration is increased. The decrease in slope just before breakdown voltage (BV) indicates that the resistance increases due to the thicker silicon oxide layers. However, the decrease in the BV suggests that the interface breaks down at a lower electric field resulting in an increase in leakage current due most likely to the presence of more conducting substance than the silicon oxide at the interface. To address how these contaminants induce the device failures, we show the cross-sectional views of the TEM images on the failed cells for the varied initial DOP concentrations in Fig. 2. The thickness of the silicon oxide layer, which was supposed to have grown to 80 A (= 8 nm), was increased from 8 nm to 13, 31 and 32 nm upon contaminating the surface by increasing the initial DOP surface concentration from 0 to 5x10 molecules/cm although the thermal oxidation of the silicon surface was carried out for the same duration in a furnace under identical experimental conditions. It is conceivable that the organic compounds may be reduced to elemental carbon in the presence of large amounts of silicon oxide at high temperature of 800C. The elemental carbon would then serve as a current leakage site, through which the current begins to flow and facilitates the breakdown of the interface. We have shown clearly that the organic contaminants are trapped during the thermal oxidation processing of silicon, which provide various routes to device failures; a portion of the organic contaminants remaining as the carbon compounds induces the expansion of the silicon oxide lattice, deteriorating the silicon oxide layer, resulting in the device failure. Results of our study clearly provide reasons for why the facilities for device fabrication must be kept extremely clean and the polymers using high concentrations of plasticizers should be avoided as much as possible from the clean room environments.

Excess caloric intake can lead to insulin resistance. The underlying reasons are complex but likely related to ectopic lipid deposition in nonadipose tissue. We hypothesized that the inability to appropriately expand subcutaneous adipose tissue may be an underlying reason for insulin resistance and beta cell failure. Mice lacking leptin while overexpressing adiponectin showed normalized glucose and insulin levels and dramatically improved glucose as well as positively affected serum triglyceride levels. Therefore, modestly increasing the levels of circulating full-length adiponectin completely rescued the diabetic phenotype in ob/ob mice. They displayed increased expression of PPARgamma target genes and a reduction in macrophage infiltration in adipose tissue and systemic inflammation. As a result, the transgenic mice were morbidly obese, with significantly higher levels of adipose tissue than their ob/ob littermates, leading to an interesting dichotomy of increased fat mass associated with improvement in insulin sensitivity. Based on these data, we propose that adiponectin acts as a peripheral "starvation" signal promoting the storage of triglycerides preferentially in adipose tissue. As a consequence, reduced triglyceride levels in the liver and muscle convey improved systemic insulin sensitivity. These mice therefore represent what we believe is a novel model of morbid obesity associated with an improved metabolic profile.

OBJECTIVE— Adiponectin increases insulin sensitivity and contributes to insulin's indirect effects on hepatic glucose production.RESEARCH DESIGN AND METHODS— To examine adiponectin's contribution to insulin action, we analyzed adiponectin levels and activation of AMP-activated protein kinase (AMPK) in insulin receptor transgenic/knockout mice (L1), a genetic model of resistance to insulin's indirect effects on hepatic glucose production.RESULTS— In euglycemic, insulin-resistant L1 mice, we detected hyperadiponectinemia with normal levels of adiponectin receptor-1 and -2. Moreover, adiponectin administration is unable to lower glucose levels or induce activation of AMPK, consistent with a state of adiponectin resistance. In a subset of hyperglycemic L1 mice, we observed decreased mRNA expression of AdipoR2 in liver and muscle, as well as decreased peroxisome proliferator–activated receptor (PPAR)α target gene expression in liver, raising the possibility that deterioration of adiponectin/AdipoR2 signaling via PPARα activation contributes to the progression from compensated insulin resistance to diabetes. In contrast, we failed to detect changes in other markers of the systemic or local inflammatory response.CONCLUSIONS— These data provide evidence for a mechanism of adiponectin resistance and corroborate the notion that adiponectin potentiates hepatic insulin sensitivity.

We have shown that mitochondrial DNA-depleted (rho(0)) SK-Hep1 hepatoma cells are resistant to apoptosis, contrary to previous papers reporting normal apoptotic susceptibility of rho(0) cells. We studied the changes of gene expression in SK-Hep1 rho(0) cells. DNA chip analysis showed that MnSOD expression was profoundly increased in rho(0) cells. O(2)(.) contents increased during rho(0) cell derivation but became normalized after establishment of rho(0) phenotypes, suggesting that MnSOD induction is an adaptive process to increased O(2)(.). rho(0) cells were resistant to menadione, paraquat, or doxorubicin, and O(2)(.) contents after treatment with them were lower in rho(0) cells compared with parental cells because of MnSOD overexpression. Expression levels and activity of glutathione peroxidases were also increased in rho(0) cells, rendering them resistant to exogenous H(2)O(2). rho(0) cells were resistant to p53, and intracellular ROS contents after p53 expression were lower compared with parental cells. Other types of rho(0) cells also showed increased MnSOD expression and resistance against ROS. Heme oxygenase-1 expression was increased in rho(0) cells, and a heme oxygenase-1 inhibitor decreased the induction of MnSOD in rho(0) cells and their resistance against ROS donors. These results indicate that rho(0) cells are resistant to cell death contrary to previous reports and suggest that an adaptive increase in the expression of antioxidant enzymes renders cancer cells or aged cells with frequent mitochondrial DNA mutations to resist against oxidative stress, host anti-cancer surveillance, or chemotherapeutic agents, conferring survival advantage on them.

A catalytic system based on Pd–CNT nanocomposites for the hydrodehalogenation of aryl halides is described. Thiol groups were utilized as linkers to secure the Pd nanoparticles without agglomeration. The Pd–CNT nanocomposites effectively promoted the hydrodehalogenation of aryl halides at a low Pd content (∼2.3%) and in the absence of any ligand. The results suggest that the CNTs could significantly influence the catalytic activities of CNT-supported metal catalysts for hydrodehalogenation.

We investigated the extent to which phosphatidylinositol 3-kinase (PI 3-kinase) and Rac, a member of the Rho family of small GTPases, are involved in the signaling cascade triggered by tumor necrosis factor (TNF)-alpha leading to activation of c-fos serum response element (SRE) and c-Jun amino-terminal kinase (JNK) in Rat-2 fibroblasts. Inhibition of PI 3-kinase by LY294002 or wortmannin, two specific PI 3-kinase antagonists, or co-transfection with a dominant negative mutant of PI 3-kinase dose-dependently blocked stimulation of c-fos SRE by TNF-alpha. Similarly, LY294002 significantly diminished TNF-alpha-induced activation of JNK, suggesting that nuclear signaling triggered by TNF-alpha is dependent on PI 3-kinase-mediated activation of both c-fos SRE and JNK. We also found nuclear signaling by TNF-alpha to be Rac-dependent, as demonstrated by the inhibitory effect of transient co-transfection with a dominant negative Rac mutant, RacN17. Our findings suggest that Rac is situated downstream of PI 3-kinase in the TNF-alpha signaling pathway to the nucleus, and we conclude that PI 3-kinase and Rac each plays a pivotal role in the nuclear signaling cascade triggered by TNF-alpha.

Mammalian acetyl-CoA carboxylase (ACC) is present in two isoforms, alpha and beta, both of which catalyze formation of malonyl-CoA by fixing CO2 into acetyl-CoA. ACC-alpha is highly expressed in lipogenic tissues whereas ACC-beta is a predominant form in heart and skeletal muscle tissues. Even though the tissue-specific expression pattern of two ACC isoforms suggests that each form may have a distinct function, existence of two isoforms catalyzing the identical reaction in a same cell has been a puzzling question. As a first step to answer this question and to identify the possible role of ACC isoforms in myogenic differentiation, we have investigated in the present study whether the expression and the subcellular distribution of ACC isoforms in H9c2 cardiac myocyte change so that malonyl-CoA produced by each form may modulate fatty acid oxidation. We have observed that the expression levels of both ACC forms were correlated to the extent of myogenic differentiation and that they were present not only in cytoplasm but also in other subcellular compartment. Among the various tested compounds, short-term treatment of H9c2 myotubes with insulin or okadaic acid rapidly increased the cytosolic content of both ACC isoforms up to 2 folds without affecting the total cellular ACC content. Taken together, these observations suggest that both ACC isoforms may play a pivotal role in muscle differentiation and that they may translocate between cytoplasm and other subcellular compartment to achieve its specific goal under the various physiological conditions.

Oxygen precipitates in Czochralski silicon (CZ-Si) are still considered as the major process-induced defects found in semiconductor device fabrication process because the role of oxygen precipitates in device process such as gettering of metal impurity, prevention of undesired wafer deformation, and degradation of carrier lifetime is quite significant to manufacture high-performance devices. Until now, various theoretical models to predict the oxygen precipitation in CZ-Si with respect to the interstitial oxygen (Oi), vacancy (CV), and the process temperature T have been suggested. However, the complexity and calculation time of a model strongly depend on the accuracy of the model. Thus, it is difficult to apply them on the evaluation of oxygen precipitation regularly in conventional wafer production. Hence, a practical and simple method to evaluate oxygen precipitation should be proposed. In this work, we derived the parameters that indicate the thermal stability and formation rate of the precipitate nuclei by analyzing as-grown oxygen precipitates formed in a p-type CZ-Si. First, we calculated a cumulative distribution function (CDF) of as-grown precipitate density with respect to the thermal history of CZ-Si crystal from the theoretical nucleation rate J(Oi, CV, T) [1]. After that, we fitted the CDF mathematically into the temperature-dependent precipitate density measured after slow ramped anneals with 1 K/min [2] at various stability temperatures followed by a growth anneal at 1000°C for 16 hours. Moreover, the first derivative Je (T) of the CDF was also calculated which was associated with an effective nucleation rate. The extreme point (T C, Je (TC)) on the Je (T) was determined as a new parameter that represents the precipitate behavior at a measured point. Finally, we correlated the parameters to the experimental results measured in various crystals after the test heat cycle started at 800°C for 4 hours and followed by 1000°C for 16 hours. As shown in Fig. 1, we found that both T C and Je (TC) were strongly correlated to the precipitate density, which means that the parameters were possibly applied to evaluate the behavior of oxygen precipitation in a crystal after various thermal processes. Fig. 1 Correlation of the T C (a) and Je (T ­C) (b) to the precipitate density measured after 2-step annealing starts at 800°C for 4 hours and followed by 1000°C for 16 hours. [1] G. Kissinger, D. Gräf, U. Lambert, and H. Richter, J. Electrochem. Soc. 144, 1447 (1997). [2] G. Kissinger and J. Dabrowski, J. Electrochem. Soc. 155, H448 (2008). Figure 1

To achieve a sufficient targeting efficiency and prolonged half-life in-vivo, the physicochemical parameters including size and surface chemistry of therapeutic and imaging agents should be controlled. In this study, we prepared an iron oxide nanoparticle (IONP)-loaded, functional nano-carrier with different loading contents to modulate the mechanical properties of the system, and compared the characteristics of tumor targeting and imaging in terms of loading contents of IONP. As a functional nano-carrier, chitosan-conjugated, Pluronic-based nano-carrier with useful properties such as long blood circulation, good tumor targeting, and easy loading of macromolecules was used. IONPs were efficiently encapsulated into the nano-carrier (high loading efficiency over 95%) and the mechanical properties of the IONP-loaded nano-carrier were controlled by varying the loading amount of IONP. The IONP-loaded nano-carrier with the higher loading content of IONP (40 wt.%) was significantly more rigid (over 2 ×) than those with lower loading contents of IONP (5 and 15 wt.%). Although the nano-carrier with the higher loading content of IONP showed more enhanced MR contrast effect with higher T 2 relaxivity and higher intracellular uptake in vitro, characteristics of in-vivo tumor targeting and MR cancer imaging were not good compared to that of the nano-carrrier with the lower loading contents of IONP. Since different loading contents did not affect other characteristics of the system (size, surface chemistry, and surface charge), the present result suggests that the mechanical properties (strength/flexibility) of nano-systems are also important factors to be controlled for targeted delivery and imaging.

In spite of several intrinsic and distinct advantages, a topical and transdermal administration of drugs has been limited mainly due to very low permeability of drugs across skin. Especially, it is generally regarded that hydrophilic macromolecules such as proteins, peptides, and vaccines cannot penetrate across skin. In this study, we demonstrated that chitosan-conjugated, Pluronic-based nano-carrier (nanogel) can act as an efficient delivery vehicle of hydrophilic proteins across human skin. The functional nano-carrier (100 nm in size), chemically-crosslinking Pluronic F 127 with chitosan conjugation, is flexible and soft with reservoir characteristics for biomacromolecules. The in-vitro permeation experiments through human cadaver skin revealed remarkable permeability of hydrophilic proteins of various sizes including FITC-BSA (67 kDa) and FITC-Insulin (6 kDa) by direct penetration of the nano-carrier across skin. The bioactivity post-permeation of proteins via the functional nano-carrier was also confirmed by delivering ß-galactosidase. Results presented in this paper suggest the use of chitosan-conjugated flexible nano-carrier as a novel platform for transcutaneous delivery of hydrophilic macromolecules and other drug-delivery applications.

Water extracts of eighteen herbal materials and genistein were used to investigate their effects on compound 48/80-induced histamine release in rat peritoneal mast cells (RPMCs). The inhibition effects of histamine release by the water extracts of Ulmus pumila Linne (UP), Lonicera japonica Thunberg (LJT), Angelica gigas Nakai (AGN), Cordyceps militaris (CM), Rehmannia glutinosa Liboschitz (RGL), Liriope platyphylla Wang et Tang (LPWT), Zizyphus jujuba var. inermis Rehder (ZJ) were evaluated by a dose-response assay. LPWT, ZJ, and genistein showed dose-dependent decrease in histamine release at the concentrations of 1 to 1,000 mg/mL, and the inhibition percentage reached up to 31.0, 35.9, and 46.2%, respectively. UP, LJT, AGN, CM, and RGL significantly decreased histamine release at 1 to 100 μg/mL. Among the various combinations, mixture of UP and genistein showed an enhanced inhibition on histamine release.

Previously, the optical imaging of chitosan-functionalized, Pluronic-based nano-carriers by Cy5.5 conjugation revealed a good tumor targeting characteristic of the nano-carriers in vivo [J. Control. Release, 147 (2010) 109-117]. However, in spite of the relatively strong signal from tumor site, they also showed strong fluorescence signals from other organs, especially liver. Thus, for the detection of pathological sites, the direct use of the Cy5.5-conjugated nano-carriers is limited due to significant background signals associated with non-specific delivery of the probes. To overcome this limitation, in this study, we prepared hydrocyanine-conjugated and chitosan-functionalized Pluronic-based nano-carriers (Hydrocyanine-NC) that can detect ROS in pathological sites. The reduction of cyanine to hydrocyanine of the nano-carriers resulted in complete disappearance of fluorescence emission, and the fluorescence could be recovered by ROS-induced re-oxidization. Hydrocyanine-NC could detect various ROS including superoxide anion (O(2)(-)) and hydroxyl radical (OH(-)) in a dose-dependent manner. Hydrocyanine-NC was also stable in serum-containing media and did not show acute cytotoxicity. Hydrocyanine-NC developed strong fluorescence by the intracellular ROS formation in LPS-stimulated macrophage cells in vitro. As an in-vivo inflammation site imaging, SCC7 tumor-bearing mice were optically monitored after the i.v. injection of the dye-conjugated nano-carriers. When non-reduced, cyanine-conjugated and chitosan-functionalized Pluronic-based nano-carriers (Cyanine-NC) were injected, strong fluorescence emission was observed from the abdominal area as well as from the tumor site, and it remained over 2days. In contrast, in the case of Hydrocyanine-NC, the initially very weak fluorescence emission from the abdominal area disappeared over time whereas the fluorescence emission from the tumor site was similar to that of Cyanine-NC. Therefore, the re-oxidation of Hydrocyanine-NC by ROS in vivo specifically eliminated the background signals from non-specific delivery of the probes, but it produced fluorescence emission strong enough to monitor the target inflammation site selectively.

Aryl-substituted alkenes (III) are synthesized by Mizoroki—Heck coupling using carbon nanotubes supported Pd(dba)2 as catalyst.

A catalytic system based on Pd–CNT nanocomposites for the hydrodehalogenation of aryl halides is described. Thiol groups were utilized as linkers to secure the Pd nanoparticles without agglomeration. The Pd–CNT nanocomposites effectively promoted the hydrodehalogenation of aryl halides at a low Pd content (∼2.3%) and in the absence of any ligand. The results suggest that the CNTs could significantly influence the catalytic activities of CNT-supported metal catalysts for hydrodehalogenation.

Quartz crystal microbalance (QCM) and atomic force microscope (AFM) were utilized to investigate the anticoagulant activities of sulfonated polymers against fibrin formation. Quantitative data on the thickness and viscoelastic properties of coagulated fibrin layers formed at various concentrations of sulfonated polymers were obtained from QCM results by applying a Voight-based model. Four types of sulfonated polymers including sulfonated chitosan (S-chitosan), monosulfonated poly(ethylene oxide) (PEO-SO(3)), disulfonated PEO (PEO-2SO(3)), and 4-arm sulfonated PEO (PEO-4SO(3)) were studied to compare with heparin in the presence or in the absence of antithrombin III (AT). All the sulfonated polymers showed the heparin-like activities to inhibit the function of thrombin for fibrin formation in the more or less extent while chitosan and PEO did not. Especially, S-chitosan prepared by sulfonation with propane sultone under a mild condition exhibited 35% of activity of free heparin while sulfonated PEOs showed 5-12% of heparin. However, there was no effect of S-chitosan without AT, indicating that the S-chitosan interfered in the fibrin formation process mainly by AT-mediated inhibition against thrombin. The sulfonated polymers not only decreased the coagulated mass but also affected the surface architecture and viscoelastic properties of the final fibrin layers coagulated. With increasing the concentrations of heparin or heparin-like polymers, the thick and textured fibrin layer was gradually diminished to reveal the thin and rigid fibrinogen-adsorbed layer, and therefore the fibrin layer became more rigid. The surface architecture of fibrin layers was confirmed by AFM. With increasing anticoagulants the density of both fibrin fiber and junctions between fibers was decreased but the fiber diameter was not much reduced.

Black raspberry juice was fermented to produce gamma-aminobutyric acid (GABA) using lactic acid bacteria (Lactobacillus brevis GABA 100) at different temperatures (25, 30, or 37 degrees C) and pHs (3.5, 4, 4.5, 5, 5.5, or 6) for 15 days. Concentrations of GABA in the juices were determined during fermentation using HPLC. GABA was produced continuously even if the viable bacterial counts markedly decreased. The fermentation at 30 degrees C generally showed higher production of GABA in the juices than those at 25 and 37 degrees C. The GABA in the juices fermented at 30 degrees C reached the maximum levels on the 12th day. The juices fermented at lower pH and lower temperature showed a lower degradation of monomeric anthocyanins. The results suggest that black raspberry juice can be GABA enriched using lactic acid bacteria.

Whereas NF-kappaB has potent antiapoptotic function in most cell types, it was reported that in pancreatic beta cells it serves a proapoptotic function and may contribute to the pathogenesis of autoimmune type 1 diabetes. To investigate the role of beta cell NF-kappaB in autoimmune diabetes, we produced transgenic mice expressing a nondegradable form of IkappaBalpha in pancreatic beta cells (RIP-mIkappaBalpha mice). beta cells of these mice were more susceptible to killing by TNF-alpha plus IFN-gamma but more resistant to IL-1beta plus IFN-gamma than normal beta cells. Similar results were obtained with beta cells lacking IkappaB kinase beta, a protein kinase required for NF-kappaB activation. Inhibition of beta cell NF-kappaB accelerated the development of autoimmune diabetes in nonobese diabetic mice but had no effect on glucose tolerance or serum insulin in C57BL/6 mice, precluding a nonphysiological effect of transgene expression. Development of diabetes after transfer of diabetogenic CD4(+) T cells was accelerated in RIP-mIkappaBalpha/nonobese diabetic mice and was abrogated by anti-TNF therapy. These results suggest that under conditions that resemble autoimmune type 1 diabetes, the dominant effect of NF-kappaB is prevention of TNF-induced apoptosis. This differs from the proapoptotic function of NF-kappaB in IL-1beta-stimulated beta cells.

Human soluble Fas ligand (sFasL) has an apoptotic activity in contrast to murine sFasL. The physiological function of human sFasL is not known, while the pathological consequence of sFasL overproduction has been reported. To understand the physiological function of (human) sFasL, murine and human lymphocytes were treated with sFasL. sFasL treatment significantly decreased CD45RBlo "memory" CD4+ lymphocyte fraction and increased propidium iodide (PI)+ apoptotic CD45RBloCD4+ lymphocytes among murine peripheral lymphocytes. However, sFasL treatment neither decreased CD45RO+ "memory" CD4+ lymphocyte fraction nor increased PI+ CD45RO+CD4+ lymphocytes among human peripheral lymphocytes, suggesting that the deletion of memory cells by sFasL had already occurred in vivo. Patients with systemic lupus erythematosus had sFasL-susceptible "memory" cell fraction suggesting an incomplete deletion of such "memory" cells. These results suggest that the physiological function of human sFasL is to delete the potentially auto-reactive "memory" lymphocytes, which complements membrane FasL (mFasL)-mediated deletion of auto-reactive cells in human beings but not in mice.

It is well-known that p38 mitogen-activated protein kinase (p38MAPK) participates in cellular responses to mitogenic stimuli, environmental and genotoxic stresses, and apoptotic agents. Although there are several reports on p38MAPK in relation to cell growth and apoptosis, the exact mechanism of p38MAPK-mediated cell growth regulation remains obscure. Here, we examined possible roles of p38MAPK in the sodium arsenite-induced cell growth inhibition in NIH3T3 cells. Sodium arsenite induced transient cell growth delay with marked activation of p38MAPK. In addition, arsenite induced CDK inhibitor p21CIP1/WAF1 and enhanced its binding to the CDK2, which resulted in inhibition of CDK2 activity. The levels of cyclin D1 expression and the CDK4 kinase activity were also significantly reduced. pRB was hypophosphorylated by sodium arsenite. SB203580, a specific inhibitor of p38MAPK, blocked arsenite-induced growth inhibition as well as the arsenite-induced p21CIP1/WAF1 expression. Expression of dominant negative p38MAPK also blocked arsenite-induced p21CIP1/WAF1 expression. Inhibited-CDK2 activity was also completely reversed by SB203580 or expression of dominant negative p38MAPK, while the decreased-cyclin D1 protein by the compound was not restored. These data demonstrate a possible link between the activation of p38MAPK and induction of p21CIP1/WAF1, suggesting that the activation of p38MAPK is, at least in part, related to the cell growth inhibition by sodium arsenite. J. Cell. Physiol. 190: 29–37, 2002. © 2002 Wiley-Liss, Inc.

Purpose:The incidence of neonatal hyperbilirubinemia is twice as high in East Asians as in Caucasians. However, its metabolic basis has not been clearly explained. The UDP-glucuronosyltransferase gene(UGT1A1) mutation was found to be a risk factor of neonatal hyperbilirubinemia. We studied whether neonatal hyperbilirubinemia is associated with the 1828G>A(rs 10929303) polymorphism of the UGT1A1 gene, which encodes for a key enzyme of bilirubin metabolism. Methods:The genomic DNA was isolated from 80 Korean full term neonates who had greater than a 12 mg/dL level of serum bilirubin with no obvious cause, and the genomic DNA was also isolated from 164 Korean neonates of the control population. We studied a single nucleotide polymorphism (SNP) of 1828G>A in the untranslated region of the UGT1A1 gene by direct sequencing. Results:Three of the 80 neonates with a serum bilirubin level above 12 mg/dL had homozygous mutations and 10 of the 80 neonates with a serum bilirubin level above 12 mg/dL had heterozygous mutations. Thirteen of the 164 neonates of the control group had homozygous mutations and 16 neonates of the control group had heterozygous mutations. The allele frequency of 1828G>A polymorphism of UGT1A1 in the hyperbilirubinemia group was 10.0 percent, which was not significantly different from the allele frequency of 12.8 percent in the control group. Conclusion:In this study, the 1828G>A polymorphism of the UGT1A1 gene was detected in the Korean neonates with neonatal hyperbilirubinemia. Our results indicated that this SNP is not associated with the prevalence of hyperbilirubinemia in Koreans.