Search

In this study, we aimed to elucidate the materialistic characteristics of 11 pieces of earthenware belonging to the Neolithic and Bronze Age excavated from Jeongseon Auraji, South Korea. As a result, the chemical composition of earthenwares belonging to the early Bronze Age was distributed in the intermediate area between the Neolithic and Bronze Age earthenwares, but no significant difference was confirmed based on their manufacturing period. Upon comparison, the earthenwares excavated from Jeongseon Auraji site were found to comprise less acidic components than those excavated from Yeongdong, and are characterized by the alkaline components depending on the excavated site. In the rare earth elements distribution pattern, all the analyzed earthenwares exhibited similar pattern, confirming that the raw materials present in the clay were the same. As a result of microstructure analysis, the clay particles and voids were found to be irregularly distributed in the analyzed earthenwares. Neolithic earthenwares exhibited many irregular voids, and an arrangement of aluminosilicate, including feldspar, was observed along with the clay substrate. Furthermore, we confirmed that the empty space in early Bronze Age earthenwares was filled with fine particles and cube crystals. Moreover, the main mineral phase of earthenwares excavated from Jeongseon Auraji exhibited similar composition, and therefore, there was no significant difference in the firing temperature of these earthenwares. The firing temperature of the earthenwares ranged from 750 to 850°C.

A kenaf-derived activated carbon (KAC) for a high-power density supercapacitor was developed in this study through phosphoric acid activation. The N2/77K isothermal adsorption–desorption curve was used to estimate the textural properties of KAC based on BET and BJH and the pore size distribution based on NLDFT. The electrochemical properties of KAC were analyzed by using the coin-type cell applying 1 M SPBBF4/PC electrolyte, and the specific surface area and total pore volume were 1490–1942 m2/g and 1.18–3.18 cm3/g, respectively. The pore characteristics of KAC varied according to the activation temperature, and most KAC showed a mesoporous structure. As the activation temperature increased, the mesopore volume increased up to 700 °C, then decreased. The mesoporous structure of KAC resulted in a substantial decrease in the Warburg impedance as the ion diffusion resistance decreased. Hence, the specific capacitance of KAC decreased from 82.9 F/g to 59.48 F/g as the charge–discharge rate increased from 1 mA/g to 10 mA/g, with the rate of reduction at approximately 30%. The rate of reduction of KAC’s specific capacitance was 50% lower compared with commercial activated carbon; hence, KAC is a more suitable electrode-active material for high power density supercapacitors.

Point defect engineering in Cu2ZnSnSe4 (CZTSe) thin films is the main issue to improve its device performance. This study reveals the correlation between the reaction pathway and the point defects in the CZTSe film. The reaction pathway from a metallic precursor (Mo/Zn/Sn/Cu) to a kesterite CZTSe film is varied by changing the annealing process. The synthesized CZTSe films under different reaction pathways induce different device performances with different defect energy levels, although all CZTSe films have similar structural and optical properties (Eg ∼ 1.0 eV). The admittance spectroscopy demonstrates the correlations between point defect types (VZn, ZnSn, ZnCu, CuZn, and VCu) and the reaction pathways for the formation of CZTSe films. The different growth rates of binary selenides, such as ZnSe and/or Sn-Se phases, during the annealing process are especially strongly related to the formation of point defects, leading to the different open-circuit voltages (396-451 mV) and fill factors (51-65%). The results of this study suggest that controlling the reaction pathway is an effective approach to adjust the formation of defects in the kesterite CZTSe film as well as to fabricate high-performance solar cell devices.

A cation substitution in Cu2ZnSn(S,Se)4 (CZTSSe) offers a viable strategy to reduce the open-circuit voltage (Voc)-deficit by altering the characteristics of band-tail states, antisite defects, and...

Due to its favorable optical properties, Cu2SnS3 (CTS) is a promising material for thin film solar cells. Doping, which modifies the absorber properties, is one way to improve the conversion efficiency of CTS solar cells. In this work, CTS solar cells with selenium doping were fabricated on a flexible substrate using sputtering method and the effect of doping on the properties of CTS solar cells was investigated. In XRD analysis, a shift in the CTS peaks can be observed due to the doped selenium. XRF analysis confirmed the different ratios of Cu/Sn and (S+Se)/(Cu+Sn) depending on the amount of selenium doping. Selenium doping can help to lower the chemical potential of sulfur. This effectively reduces the point defects of CTS thin films. Overall improved electrical properties were observed in the CTS solar cell with a small amount of selenium doping, and a notable conversion efficiency of 1.02 % was achieved in the CTS solar cell doped with 1 at% of selenium.

In this study, we prepared ACFs with a high specific surface area from various precursors (rayon, pitch, and oxidized polyacrylonitrile-based fibers) by a steam-activation technique and investigated the effects of the micropore and mesopore fraction on 2-CEES adsorption behaviors. The activation time was precisely controlled so that the activation yield was in the range of 35–40% to ensure the mechanical properties of the ACFs. The N2 adsorption isotherm characteristics at 77K were confirmed by Brunauer–Emmett–Teller, Barrett–Joyner–Halenda and non-local density functional theory equations. The adsorption capacities of the ACF were measured by breakthrough experiments in the gas phase (750 μg/mL of 2-CEES in N2 flow). The removal efficiency of the ACFs was evaluated and compared with that of AC. From the results, specific surface areas and total pore volume of the ACF were determined to be 1380–1670 m2/g and 0.61–0.82 cm3/g, respectively. It was also observed that various pore characteristics of ACF were found to be dependent on crystallite structure of each precursor. The break through time (C/C0 = 0.10) was in the order of Oxi-Pan-H-9-2

A cation substitution in Cu

Bee venom (BV) from honey bee (Apis Melifera L.) contains at least 18 pharmacologically active components including melittin (MLT), phospholipase A2 (PLA2), and apamin etc. BV is safe for human treatments dose dependently and proven to possess different healing properties including antibacterial and antiparasitidal properties. Nevertheless, antiviral properties of BV have not well investigated. Hence, we identified the potential antiviral properties of BV and its component against a broad panel of viruses. Co-incubation of non-cytotoxic amounts of BV and MLT, the main component of BV, significantly inhibited the replication of enveloped viruses such as Influenza A virus (PR8), Vesicular Stomatitis Virus (VSV), Respiratory Syncytial Virus (RSV), and Herpes Simplex Virus (HSV). Additionally, BV and MLT also inhibited the replication of non-enveloped viruses such as Enterovirus-71 (EV-71) and Coxsackie Virus (H3). Such antiviral properties were mainly explained by virucidal mechanism. Moreover, MLT protected mice which were challenged with lethal doses of pathogenic influenza A H1N1 viruses. Therefore, these results provides the evidence that BV and MLT could be a potential source as a promising antiviral agent, especially to develop as a broad spectrum antiviral agent.

The belief that honey bee venom (BV) can be used to treat certain immune-related diseases, such as arthritis and rheumatic conditions, goes back to antiquity. A growing number of reports have demonstrated that BV contains at least 18 pharmacologically active components, including phospholipase A2 (PLA2). Recent research has shown that bee venom PLA2 (bvPLA2) induces protective immune responses against several diseases including asthma, Parkinson’s disease, and drug-induced organ inflammation. However, the antiviral properties of bvPLA2 have not been well investigated. Hence, we examined the potential inhibitory effects of bvPLA2 and its possible mechanism of action against a broad panel of pathogenic viruses in vitro. Pre-treatment with bvPLA2 significantly inhibited the replication of vesicular stomatitis virus (VSV), coxsackie virus (H3), enterovirus-71 (EV-71), herpes simplex virus (HSV) and Adenovirus (AdV) dramatically. However, bvPLA2 did not show antiviral activity against Influenza A virus (PR8) and Newcastle disease virus (NDV). Such inhibitory effects were explained by blocking of the attachment of the virus to cells upon bvPLA2 treatment. Additionally, we observed that Heparan sulfate (HS) has an inhibitory effect on the attachment of HSV to the cell surface dose dependently, which was inconsistent with bvPLA2 treatment. These findings suggest that bvPLA2 has an inhibitory effect on the replication of diverse viruses by blocking their attachment to the cell surface and could be a promising source of natural antiviral agents.

Herein, an integrated device that comprises inorganic kesterite solar cells and Li-ion batteries (LIBs) has been proposed for application in fast photo-charging power systems. LiFePO4 and Li4Ti5O12 were selected as the battery electrode materials and six kesterite solar cells connected in series were fabricated to satisfy the charging voltage required for LIBs. Photo-charging was conducted at the rate of 1C (1.790 mAh g−1) at 2.1 V. An energy conversion and storage efficiency of 3.87% was acquired in the integrated device, and a storage efficiency of over 70% was observed in LIBs. Furthermore, by synchronizing the charging voltage of the solar cell and LIB, over 70% of the capacity was obtained at the rate of 1C, while preventing overvoltage during long-term charging.

Angelica tenuissima Nakai is a widely used commodity in traditional medicine. Nevertheless, no study has been conducted on the antiviral and immune-modulatory properties of an aqueous extract of Angelica tenuissima Nakai. In the present study, we evaluated the antiviral activities and the mechanism of action of an aqueous extract of Angelica tenuissima Nakai both in vitro and in vivo. In vitro, an effective dose of Angelica tenuissima Nakai markedly inhibited the replication of Influenza A virus (PR8), Vesicular stomatitis virus (VSV), Herpes simplex virus (HSV), Coxsackie virus, and Enterovirus (EV-71) on epithelial (HEK293T/HeLa) and immune (RAW264.7) cells. Such inhibition can be described by the induction of the antiviral state in cells by antiviral, IFNrelated gene induction and secretion of IFNs and pro-inflammatory cytokines. In vivo, Angelica tenuissima Nakai treated BALB/c mice displayed higher survivability and lower lung viral titers when challenged with lethal doses of highly pathogenic influenza A subtypes (H1N1, H5N2, H7N3, and H9N2). We also found that Angelica tenuissima Nakai can induce the secretion of IL-6, IFN-λ, and local IgA in bronchoalveolar lavage fluid (BALF) of Angelica tenuissima Nakai treated mice, which correlating with the observed prophylactic effects. In HPLC analysis, we found the presence of several compounds in the aqueous fraction and among them; we evaluated antiviral properties of ferulic acid. Therefore, an extract of Angelica tenuissima Nakai and its components, including ferulic acid, play roles as immunomodulators and may be potential candidates for novel anti-viral/anti-influenza agents.

The fringe-field switching (FFS) mode that uses liquid crystals (LCs) with negative dielectric anisotropy is used in high-resolution FFS liquid crystal display owing to its higher transmittance over positive LC, although its response time becomes slow and operating voltage (Vop) becomes high. In the device, reduction of the cell gap is required to achieve fast response time, which results in increase in Vop in general. In this paper, we propose the FFS mode with electrode width 1 µm and distance between the electrodes 1.5 µm. In such an electrode structure, Vop decreases with decreasing cell gap to 2 µm so that a proper Vop, high LC's light efficiency of 90%, a high color temperature, and a fast response time less than 10 ms, can be achieved, which maximizes electro-optic performance of the FFS mode.

Epimedium koreanum Nakai has been extensively used in traditional Korean and Chinese medicine to treat a variety of diseases. Despite the plant’s known immune modulatory potential and chemical make-up, scientific information on its antiviral properties and mode of action have not been completely investigated. In this study, the broad antiviral spectrum and mode of action of an aqueous extract from Epimedium koreanum Nakai was evaluated in vitro, and moreover, the protective effect against divergent influenza A subtypes was determined in BALB/c mice. An effective dose of Epimedium koreanum Nakai markedly reduced the replication of Influenza A Virus (PR8), Vesicular Stomatitis Virus (VSV), Herpes Simplex Virus (HSV) and Newcastle Disease Virus (NDV) in RAW264.7 and HEK293T cells. Mechanically, we found that an aqueous extract from Epimedium koreanum Nakai induced the secretion of type I IFN and pro-inflammatory cytokines and the subsequent stimulation of the antiviral state in cells. Among various components present in the extract, quercetin was confirmed to have striking antiviral properties. The oral administration of Epimedium koreanum Nakai exhibited preventive effects on BALB/c mice against lethal doses of highly pathogenic influenza A subtypes (H1N1, H5N2, H7N3 and H9N2). Therefore, an extract of Epimedium koreanum Nakai and its components play roles as immunomodulators in the innate immune response, and may be potential candidates for prophylactic or therapeutic treatments against diverse viruses in animal and humans.

Anisotropically structured upconversion nanocrystals capable of exhibiting bright upconversion emission properties are a promising new class of high performance optical materials. In this study, we investigate a facile synthetic method for the new nanoplate structure of YF3:Yb3+/Er3+ with enhanced luminescence intensity. The shape of YF3:Yb3+/Er3+ nanocrystals can be controlled by changing the synthesis conditions of the NaOH concentration, reaction time, and surfactant. The concentration of NaOH determines the final structure of YF3:Yb3+/Er3+. By increasing the NaOH concentration from 0.25 mmol to 2.5 mmol, YF3:Yb3+/Er3+ nanoplates transform into NaYF4:Yb3+/Er3+ nanoparticles; in the absence of NaOH, the nanoplate structure of YF3:Yb3+/Er3+ changes to particles. The YF3:Yb3+/Er3+ nanoplates show luminescence efficiency much greater than that of the spherical YF3:Yb3+/Er3+ nanocrystals.

Dense granule protein-7 (GRA-7) is an excretory protein of Toxoplasma gondii. It is a potential serodiagnostic marker and vaccine candidate for toxoplasmosis. Previous reports demonstrated that GRA-7 induces innate immune responses in macrophages by interacting with TRAF6 via the MyD88-dependent pathway. In the present study, we evaluated the antiviral activity and induction of an antiviral state by GRA-7 both in vitro and in vivo. It was observed that GRA-7 markedly reduced the replication of vesicular stomatitis virus (VSV-GFP), influenza A virus (PR8-GFP), coxsackievirus (H3-GFP), herpes simplex virus (HSV-GFP), and adenovirus-GFP in epithelial (HEK293T/HeLa) and immune (RAW264.7) cells. These antiviral activities of GRA-7 were attributed to the induction of type I interferon (IFN) signaling, resulting in the secretion of IFNs and pro-inflammatory cytokines. Additionally, in BALB/c mice, intranasal administration of GRA-7 prevented lethal infection by influenza A virus (H1N1) and exhibited prophylactic effects against respiratory syncytial virus (RSV-GFP). Collectively, these results suggested that GRA-7 exhibits immunostimulatory and broad spectrum antiviral activities via type I IFN signaling. Thus, GRA-7 can be potentially used as a vaccine adjuvant or as a candidate drug with prophylactic potential against viruses.

논문투고일：2014년 04월 26일 논문수정완료일：2014년 06월 10일 논문게재확정일：2014년 60월 13일* BNF1000,Corporations look for their competitiveness in many different a reas, and one of them is customer call center, which provides professional, special service to the customers. The importance and the value of realization of customer satisfaction at each call center have become significant as it plays a leading role and is responsible for customer recreation and follow-up servic es. This study held in-depth interviews with 3 groups of profession al call representatives (categorized by experience) from popular property and life insurance companies in Korea who oper ate in and outbound calls. Three variables, emotional quotient, organizational citizenship behavior (OCB), and IT utilization s kill, were selected and it was observed how these variables aff ect the job performance of in and outbound call center representati ves. The importance of the relationship between the variables and the key factors in the future direction of improvement of t he call center representative organization was analyzed. Emotional quotient refers to the ability to recognize and use t he emotion of oneself and others. It was considered it would be effective in enhancing the counseling ability of call center representatives, This study identifies the effect of emotional quotient on job performance and organizational citizenship beha vior, which is defined as actions outside of normative roles in the organization. Also, the study aims to prove the effect o f emotional quotient on the rapidly developing IT utilization a bility in relation to job performance. As a result, it was found that service career (3 months, 3 year s, 10 years) had a significant effect on the key factors that affect the organization-emotional quotient, IT utilization skill, and OCB. Especially for OCB, it was considered relatively less important to the new employees, while it greatly affected the job performance, rate of settlement, and sustainment of the working life for those with longer experience. Also, the re sult of the interview for each variable differed by the service career. Emotional quotient, IT utilization skill, and OCB were close connection for the representatives with longer experience than for those with shorter experience. And the level of intima cy of their relationship with job performance was in proportion to the years of service. Thus, to secure stability for the call center representatives and enhance their job performance continually, the importance of emotional quotient and IT utilization skill shall be reflected in the operation process actively. In particular, in order t o lead a organization with outstanding culture, a management system sh all apply OCB from the recruitment process.

The fringe-field switching (FFS) mode that uses liquid crystals (LC) with negative dielectric anisotropy is used in high resolution FFS-LCD owing to its higher transmittance over positive LC. In this paper, the FFS mode with electrode width 1 µm and distances between the electrodes 1.5 µm is proposed. In such an electrode structure, operating voltage (Vop) decreases with decreasing cell gap to 2 µm so that a proper Vop, high LC's light efficiency of 90%, and a fast response time less than 10 ms, can be achieved, which maximizes electro-optic performance of the FFS mode. In addition, the color temperature of a white state becomes higher in the fine patterned FFS cell.

In-plane field driven vertical alignment device using a liquid crystal with positive dielectric anisotropy has been studied. In the device, the distance between inter-digital electrodes needs to be increased to achieve higher transmittance; however, such a design results in an increase in operating voltage and slower response time. In this work, we use polymer stabilisation technique, which generates surface tilt angle other than 90o, to improve upon these drawbacks. As a result, the proposed device shows lower operating voltage and faster response time while keeping transmittance at the same level, compared to those prior to polymer stabilisation.

Coptidis Rhizoma is derived from the dried rhizome of Ranunculaceous plants and is a commonly used traditional Chinese medicine. Although Coptidis Rhizoma is commonly used for its many therapeutic effects, antiviral activity against respiratory syncytial virus (RSV) has not been reported in detail. In this study, we evaluated the antiviral activities of Coptidis Rhizoma extract (CRE) against RSV in human respiratory tract cell line (HEp2) and BALB/c mice. An effective dose of CRE significantly reduces the replication of RSV in HEp2 cells and reduces the RSV-induced cell death. This antiviral activity against RSV was through the induction of type I interferon-related signaling and the antiviral state in HEp2 cells. More importantly, oral administration of CRE exhibited prophylactic effects in BALB/c mice against RSV. In HPLC analysis, we found the presence of several compounds in the aqueous fraction and among them; we confirmed that palmatine was related to the antiviral properties and immunemodulation effect. Taken together, an extract of Coptidis Rhizoma and its components play roles as immunomodulators and could be a potential source as promising natural antivirals that can confer protection to RSV. These outcomes should encourage further allied studies in other natural products.

Performance and anti-corrosion of cold forged fuel pumps and die-casting fuel pumps have been tested in this study. Ethanol with 10 ppm of acetic acid is applied for the anti-corrosion test for 250 hours. Performance test result shows that the pumping efficiency of the cold forged fuel pump is equivalent to that of the die-casting fuel pump. The cold forged lower housing has better quality against corrosiveness and finer metallic structure than the die-casting lower housing does. Key Words : Fuel Pump, Cold Forging, Lower Hosing, Anti-Corrosion, Die-Casting * 교신저자 : 박성영(sungyoung@kongju.ac.kr)접수일 11년 11월 07일 수정일 12년 01월 03일 게재확정일 12년 01월 05일 1. 서론 현재까지 자동차용 연료펌프의 설계법, 성능예측 및 향상에 대해서 연구가 다수 이루어졌지만 자동차용 연료펌프의 효율 향상과 신뢰성 있는 설계법이 아직도 만족할 만한 결과를 보이지 못하고 있다. 특히 연료펌프에 대한 국내 연구는 연료 펌프 생산업체 위주로 소극적 개발이 진행되어 왔으며, 다양한 형상 및 인자에 따른 실험 결과에 근거한 설계법 및 성능 예측법은 실제 제품에 적용하기에 무리가 있다[1]. 자동차용 연료펌프는 국내 시판되는 가솔린 자동차의 거의 대부분에 사용되고 있음에도 불구하고 설계기술을 포함하는 핵심 기술들은 외국의 소수 자동차부품 전문 기술업체만이 보유하고 있다. 국내시장을 차지하는 대부분의 국내업체들도 이들 외국기업의 자본으로 이루어졌기 때문에 국내업체들은 독자적으로 기술개발을 수행하기 어려운 환경에 처해져 있으며, 생산 및 제조 기술에서 경쟁력이 있음에도 해외 판매 및 제품 개발에 한계를 가지고 있다. 세계적으로 완성차업체들의 글로벌 소싱이 현실화되고, 그에 따른 연료펌프의 시장이 확대되고 있는 상황에서 펌프의 효율 향상 및 신뢰성 있는 설계법의 확보는 기업의 글로벌 경쟁력을 확보하는데 필수적인 요소라 할 수 있다[2,3].가솔린 자동차의 연료펌프는 차량의 연료탱크 내부에 설치되어 연료탱크에서 엔진으로 연료를 공급하는 장치이다. 초기 용적형 연료펌프의 토출압 맥동, 소음․진동 등의 문제점을 해결하기 위하여 재생펌프(Regenerative Pump)가 도입되었으며, 현재 대부분의 가솔린 자동차용

Angelica tenuissima Nakai is a widely used commodity in traditional medicine. Nevertheless, no study has been conducted on the antiviral and immune-modulatory properties of an aqueous extract of Angelica tenuissima Nakai. In the present study, we evaluated the antiviral activities and the mechanism of action of an aqueous extract of Angelica tenuissima Nakai both in vitro and in vivo. In vitro, an effective dose of Angelica tenuissima Nakai markedly inhibited the replication of Influenza A virus (PR8), Vesicular stomatitis virus (VSV), Herpes simplex virus (HSV), Coxsackie virus, and Enterovirus (EV-71) on epithelial (HEK293T/HeLa) and immune (RAW264.7) cells. Such inhibition can be described by the induction of the antiviral state in cells by antiviral, IFNrelated gene induction and secretion of IFNs and pro-inflammatory cytokines. In vivo, Angelica tenuissima Nakai treated BALB/c mice displayed higher survivability and lower lung viral titers when challenged with lethal doses of highly pathogenic influenza A subtypes (H1N1, H5N2, H7N3, and H9N2). We also found that Angelica tenuissima Nakai can induce the secretion of IL-6, IFN-λ, and local IgA in bronchoalveolar lavage fluid (BALF) of Angelica tenuissima Nakai treated mice, which correlating with the observed prophylactic effects. In HPLC analysis, we found the presence of several compounds in the aqueous fraction and among them; we evaluated antiviral properties of ferulic acid. Therefore, an extract of Angelica tenuissima Nakai and its components, including ferulic acid, play roles as immunomodulators and may be potential candidates for novel anti-viral/anti-influenza agents.

Background Cortex Phellodendri (C. Phellodendri), the dried trunk bark of Phellodendron amurense Ruprecht, has been known as a traditional herbal medicine, showing several bioactivities. However, antiviral activity of C. Phellodendri aqueous extract (CP) not reported in detail, particularly aiming the prophylactic effectiveness. Methods In vitro CP antiviral activity evaluated against Influenza A virus (PR8), Vesicular Stomatitis Virus (VSV), Newcastle Disease Virus (NDV), Herpes Simplex Virus (HSV), Coxsackie Virus (H3-GFP) and Enterovirus-71 (EV-71) infection on immune (RAW264.7) and epithelial (HEK293T/HeLa) cells. Such antiviral effects were explained by the induction of antiviral state which was determined by phosphorylation of signal molecules, secretion of IFNs and cytokines, and cellular antiviral mRNA expression. Furthermore, Compounds present in the aqueous fractions confirmed by HPLC analysis and evaluated their anti-viral activities. Additionally, in vivo protective effect of CP against divergent influenza A subtypes was determined in a BALB/c mouse infection model. Results An effective dose of CP significantly reduced the virus replication both in immune and epithelial cells. Mechanically, CP induced mRNA expression of anti-viral genes and cytokine secretion in both RAW264.7 and HEK293T cells. Furthermore, the main compound identified was berberine, and shows promising antiviral properties similar to CP. Finally, BALB/c mice treated with CP displayed higher protection levels against lethal doses of highly pathogenic influenza A subtypes (H1N1, H5N2, H7N3 and H9N2). Conclusion CP including berberine play an immunomodulatory role with broad spectrum antiviral activity, due to induction of antiviral state via type I IFN stimulation mechanism. Consequently, C. Phellodendri could be a potential source for promising natural antivirals or to design other antiviral agents for animal and humans. Electronic supplementary material The online version of this article (doi:10.1186/s12906-016-1206-x) contains supplementary material, which is available to authorized users.

Electrospray ionization mass spectra of PA-6 and berberine. The molecular weight identification of PA-6 (A) and berberine (B) was carried out by ESI-MS. (PPTX 145Â kb)

The heavy metal cadmium is a xenobiotic toxicant of environmental and occupational concern and it has been classified as a human carcinogen. Inhalation of cadmium has been implicated in the development of emphysema and pulmonary fibrosis, but, the detailed mechanism by which cadmium induces adverse biological effects is not yet known. Therefore, we undertook the investigation of genes that are induced after cadmium exposure to illustrate the mechanism of cadmium toxicity. For this purpose, we employed the polymerase chain reaction (PCR)-based suppression subtractive hybridization (SSH) technique. We identified 29 different cadmium-inducible genes in human peripheral blood mononuclear cells (PBMCs), such as macrophage migration inhibitory factor (MIF), lysophosphatidic acid acyltransferase-alpha, enolase-1alpha, VEGF, Bax, and neuron-derived orphan receptor-1 (Nor-1), which are known to be associated with inflammation, cell survival, and apoptosis. Induction of these genes by cadmium treatment was further confirmed by semi-quantitative reverse-transcription PCR. Further, we found that these genes were also induced after cadmium exposure in normal human lung fibroblast cell line, WI-38, suggesting potential use of this induction profile to monitor cadmium toxicity in the lung.

The device characteristics of a gradual hole injection dual-gate lateral insulated gate bipolar transistor (GHI-LIGBT) is analyzed with the experiment and two-dimensional (2-D) numerical simulation. The hole injection mechanism in the GHI-LIGBT is investigated in detail and the device characteristics of the GHI-LIGBT are studied in terms of the various device parameters such as the p/sup +/ injector length and the injection gate length. The hole injection characteristics and latch-up characteristics in the GHI-LIGBT are also presented as a function of temperature. The experimental results demonstrate that an on-state voltage drop in GHI-LIGBT is reduced by 1 V, compared with the conventional SA-LIGBT and the negative resistance regime is eliminated since the injection of holes is initiated at the lower anode voltage. It is also found that the low on-state voltage drop in the GHI-LIGBT can be achieved without sacrificing the inherent high switching speed in shorted anode (SA) LIGBT structures.

We have firstly demonstrated a hybrid flash including both NOR and NAND cell in a single chip using 90 nm logic technology for S-SIM (Super-Subscriber Identity Module) application. The memory sizes are 16 MB NAND and 768 kB NOR flash, respectively. The flash memory cells exhibited over 10 k-cycle endurance and 10-year retention for the successful smart card application.

A polymer-stabilized vertical alignment (PS-VA) mode using a new type of photoreactive monomer for polymer stabilization of the liquid crystal (LC) director was developed. Conventional reactive mesogens having a higher molecular weight than those of the host LC tend to aggregate and form large-sized polymer grains when exposed to ultraviolet (UV) light, subsequently deteriorating the quality of the dark state. To address these problems, bis(4-hydroxyphenyl) diacrylates were synthesized with four different linking groups as stabilizing monomers (SMs) which have molecular weights similar to that of the host LC. Their stabilizing characteristics with respect to the molecular size and polarity of SMs were evaluated by examining the electro-optic characteristics of LC cells after UV irradiation. The results showed that the SM containing a small linking group in size between biphenyls with high polarity was favored to achieve excellent polymer stabilization. The SM containing an ether linkage showed excellent electro-optic characteristics with no large-sized polymer grains even in the absence of a photo-initiator. Consequently, we anticipate that SMs, polar and smaller in size, can improve the electro-optic characteristics in PS-VA mode.

We propose and fabricate a new base resistance-controlled thyristor (BKT) employing a self-aligned corrugated p-base. The new device, entitled CB-BRT, suppresses the snap-back effectively and increases the maximum controllable current. Experimental results show that the snap-back of the CB-BRT is reduced significantly when compared with that of the conventional BRT. Also, the maximum controllable current of the CB-BRT increases as compared with the conventional BRT.

A new shorted-anode lateral insulated gate bipolar transistor (SA-LIGBT), entitled gradual hole injection dual gate LIGBT (GHI-LIGBT), is proposed and fabricated. The new device employs a dual gate and p/sup +/ injector in order to initiate the hole injection gradually from the anode electrode into the drift region so that the negative differential resistance (NDR) regime may be eliminated. The experimental results show that the NDR regime, which may cause undesirable device characteristics, is completely eliminated in the GHI-LIGBT, and the forward voltage drop is reduced by 1 V at the current density of 200 A/cm/sup 2/ in comparison with the conventional SA-LIGBT.

A new shorted-anode lateral IGBT with dual gate and p/sup +/ injector (DG-SALIGBT) is proposed and fabricated in order to eliminate the negative differential resistance (NDR) regime, which is the inherent characteristic of SALIGBTs, by modulating the drift region conductivity gradually. The experimental results show that the NDR regime is eliminated completely and the forward voltage drop is reduced considerably in the DG-SALIGBT when compared with the conventional SALIGBT, without sacrificing the switching speed. We have analyzed the device operation mechanism, such as hole injection phenomena, by 2D numerical simulation.

A Hybrid Schottky INjector Field Effect Transistor (HSINFET) which increases the forward conduction current without sacrificing the latch-up capability and turn-off characteristics, is proposed. The feature of the structure is that the hybrid Schottky injector is implemented by the trench sidewall Schottky contact and p-n junction injector at the bottom of a trench. The device characteristics of the proposed HSINFET are numerically simulated and compared with conventional devices. The proposed HSINFET exhibits a lower forward voltage drop than the conventional HSINFET by 0.4 V at 100 A/cm/sup 2/.

We proposed a method to reduce the operating voltage and the grey-to-grey switching time of a vertically aligned liquid crystal display using a mixture of planar and vertical polyimide alignment materials. The surface anchoring energy of the two-polyimide mixture was smaller than that of the pure vertical polyimide and consequently, liquid crystal molecules were easily switched to a planar state with an electric field, resulting in a greater maximum retardation than that of the pure polyimide at the same applied voltage. Rising time was also significantly reduced due to the suppressed optical bouncing effect in the mixed planar polyimide, and the decaying time showed negligible change. With the proposed approach, we can reduce the cell gap to obtain half-wave retardation allowing for faster response time while keeping a low operating voltage. (Some figures may appear in colour only in the online journal)

We developed a robust measurement recipe for six layer SOI film stack. Both spectrometer and BPR were combined to characterize the plate and storage polysilicons. A new global optimization method was developed to find the best solution in parameter spaces with up to 12 parameters. Such a recipe was applied to production wafers with over 50 site die mapping. The 5 day repeatability shows the measurements were stable and robust.