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We report on the fabrication and electrical transport properties of gate-tunable superconducting quantum interference devices (SQUIDs), made of semiconducting PbS nanowire contacted with PbIn superconducting electrodes. Applied with a magnetic field perpendicular to the plane of the nano-hybrid SQUID, periodic oscillations of the critical current due to the flux quantization in SQUID are observed up to T = 4.0 K. Nonsinusoidal current-phase relationship is obtained as a function of temperature and gate voltage, which is consistent with a short and diffusive junction model., Comment: 14 pages, 4 figures

We report a novel negative photoconductivity (NPC) mechanism in n-type indium arsenide nanowires (NWs). Photoexcitation significantly suppresses the conductivity with a gain up to 10(5). The origin of NPC is attributed to the depletion of conduction channels by light assisted hot electron trapping, supported by gate voltage threshold shift and wavelength-dependent photoconductance measurements. Scanning photocurrent microscopy excludes the possibility that NPC originates from the NW/metal contacts and reveals a competing positive photoconductivity. The conductivity recovery after illumination substantially slows down at low temperature, indicating a thermally activated detrapping mechanism. At 78 K, the spontaneous recovery of the conductance is completely quenched, resulting in a reversible memory device, which can be switched by light and gate voltage pulses. The novel NPC based optoelectronics may find exciting applications in photodetection and nonvolatile memory with low power consumption.

We report several quantum interference effects in graphene grown by chemical vapor deposition. A crossover between weak localization and weak antilocalization effects is observed when varying the gate voltage and we discuss the underlying scattering mechanisms. The characteristic length scale for phase coherence is compared with that estimated from universal conductance fluctuations in the microporeformed graphene sample. These extensive temperature- and gate-dependent measurements of the intervalley and intravalley scattering lengths provide important and useful insight for the macroscopic applications of graphene-based quantum devices., Comment: Current Applied Physics, vol.16 pg.31 (2016)

Molecular tweezers based on chenodeoxycholic acid bearing different lengths of arm were synthesized and their anion binding affinities were evaluated by 1 H NMR, isothermal calorimetric titration, and ESI mass spectrometry. Molecular tweezer 6 showed a high selectivity toward H 2 PO 4 - over Cl - , Br - , I - , and CH 3 CO 2 - by 1 H NMR titration, whereas the association constant for F - revealed the largest value as determined by ITC. The selectivity of 6 towards F - was about 10 3 times higher than that of Cl - , H 2 PO 4 - , and CH 3 CO 2 - . ITC experiment of 6 with F - in a DMSO showed two binding modes; two sequential association constants K 1 = 2.77 × 10 5 M -1 and K 2 = 8.68 x 10 6 M -1 were found. These sequential bindings were confirmed by ESI mass spectrometry. 1: 1 and 1: 2 complexes of 6 and F - were found at m/z 868.08 and 884.04.

Synthesis of cholic acid-based tripodal receptor (1) and its high chloride ion affinity in comparison with that of chenodeoxycholic acid (2) and lithocholic acid-based receptor (3) was achieved. Anion binding affinities of the receptors were evaluated NMR and ITC titrations. Tripodal receptor 1 showed a selective affinity for over , , , and . The selectivity of 1 for is about 3 times that of , and 17 times that for .

A new molecular tweezer receptor Hc1 based on hyodeoxycholic acid has been synthesized and its binding properties were accessed by 1 H NMR and isothermal titration calorimetry experiments. Molecular tweezer Hc1 shows a high selectivity toward F − over Cl − , Br − , I − , and H 2 PO 4 − .

本論文は、21世紀のグローバル・ロジスティクス戦略の在り方を明らかにすると同時に、グローバル・ロジスティクス戦略の課題を体系的に提案するのが目的である。そこで、理論と事例研究を通じて幾つかの課題を提案した。研究の結果、グローバル・ロジスティクス戦略は、環境志向型のグローバル経営戦略と整合性がとれたサプライチェーン・マネジメント(SCM: Supply Chain Management, 以下SCM)戦略をベースにしたグローバル・サプライチェーン・ロジスティクス・システムの体系的な構築と運営にあることが明らかになった。

In warm forming of aluminum sheet materials, determination, realization, and maintenance of optimal temperature gradient is a key process parameter for increased formability. In this study, a two-phase procedure for efficient and accurate determination of proper temperature condition for warm forming of aluminum sheet metal blanks is presented using a hybrid 3D isothermal/non-isothermal finite element analysis (FEA) and design of experiments (DOE) approach. First, the relative trend, priority and overall temperature ranges of aluminum sheet metal blank regions are obtained using isothermal FE modeling and DOE techniques to reduce the analysis time significantly. In this phase, different temperature levels were assigned onto different regions of the deforming blank material (i.e., holding region, corner region, etc.). Heat transfer with the tooling and environment during the deformation process is ignored in order to achieve rapid predictions. Second, few additional non-isothermal FEAs, taking heat transfer into account, are conducted to validate and to refine the warm forming conditions based on the results from the isothermal FEA/DOE analysis. The proposed hybrid methodology offers rapid and relatively accurate design of warm forming process, especially for large parts that require 3D FE analysis. In addition, effects of forming speed v, friction , and blank holder pressure on formability are investigated. Increasing part formability is observed with decreasing punch speed and blank holder pressure while an optimal process window is found in case of varying friction coefficients. DOI: 10.1115/1.2162913

A highly stereoselective reductive amination method was developed based on in situ generated sodium acyloxyborohydride and was successfully applied to a steroidal skeleton with various amine sources. High yield (96%) and a de of up to 95% were achieved by modifying the reducing reagent. The effect of this reagent will be discussed.

In this study, thermomechanically coupled finite element analysis (FEA) was performed for forming aluminum rectangular cups at elevated temperatures. In order to identify the onset of a failure during FEA, applicability, accuracy, and repeatability of three different failure criteria (maximum load, minimum thickness, and thickness ratio) were investigated. The thickness ratio criterion was selected since it resulted in accurate prediction of necking-type failure when compared with experimental measurements obtained under a variety of warm forming conditions. Predicted part depth values from FEA at various die-punch temperature combinations and blank holder pressures conditions were also compared with experiments, and showed good agreement. Forming limit diagrams were established at three different warm forming temperature levels (250°C, 300°C, and 350°C). An increasing limiting strain was observed with increasing forming temperature both in FEA and experiments. In addition, strain distributions on the formed part obtained under different die-punch temperature combinations were also compared to further validate the accuracy of FEA. A high temperature gradient between die and punch (Tdie>Tpunch) was found to result in increased formability; i.e., high part depths.

Gas assisted injection molding (GAIM) is an innovative low-pressure injection molding technique that can provide numerous benefits such as reduced part warpage, excellent surface quality without sink marks, low injection pressure and greater design flexibility. However, adoptions of GAIM may cause unexpected defects since it requires many subtle design factors such as resin shot size, delay time and gas injection pressure, which wouldn`t be considered in conventional injection molding process. Therefore, experiences applying GAIM should be collected and examined in order to establish design rules of the new technique. The purpose of this paper is to summarize developing cases of three automotive interior parts such as instrument panel, map pocket folding and center facia side panel so that possibilities and limitations of GAIM were examined. As a result, it is necessary to consider characteristics of GAIM at the initial stage of part design in order to obtain various advantages of the GAIM process without occurring severe defects, which would increase time and cost required to the part development.

Tail suspension is a ground-based model for the microgravity and cephalic fluid-shift aspects of spaceflight. To evaluate osteopenia and bone metabolism induced by microgravity, 18 8-week-old female Spraque-Dawley (SD) rats completed tail suspension for 2-weeks (n=6, TS), and were compared with baseline controls (n=6, BC) and 2-week vivarium control rats (n=6, VC). The BC, VC, and TS groups were fed standard lab chow (CRF-1, Charles River, Japan) and water ad libitum while control animals (BC and VC) were pair fed with the appropriate TS group to control for caloric intake. After 2-week suspension, the rats were sacrificed and femurs were removed for analysis of bone mineral density (BMD) by dual energy X-ray absorptionmetry (DEXA, Lunar DPXL, USA) and peripheral quantitative computed tomography (pQCT, XC-960, Germany). The femoral fresh weight of the TS group was approximately 8% lower when compared with the VC group (p

Chemical Sensor Research Group, Department of Chemistry, Kwangwoon University, Seoul 139-701, KoreaReceived April 20, 2004A short and efficient synthesis, solvent extraction and potentiometric measurements of new thiazole-containingnaphtho-crown ethers are reported. The naphthalene moiety enhances the ammonium ion selectivity overpotassium ion. The selectivity of NH

We report evidence of photoisomerization-induced complexation with l -phenylalanine in the thin film of spironaphthoxazine (SNO)–alkanethiol self-assembled monolayer by surface plasmon resonance (SPR). The betainic nature of merocyanine give rise to simultaneous binding of the positively changed ammonium group and anionic carboxylate function of l -phenylalanine under UV irradiation. SPR revealed that increased l -phenylalanine concentration afforded an increase in the relative resonance angle shift.

Protein and gene detection have been growing importance in medical diagnostics. Field effect transistor (FET) - type biosensors have many advantages such as miniaturization, standardization, and mass-production. In this work, we have fabricated metal-oxide-semiconductor (MOS) FET that operates as molecular recognitions based electronic sensor. Measurements were taken with the devices under phosphate buffered saline solution. The drain current () was decreased after forming self-assembled mono-layers (SAMs) used to capture the protein, which resulted from the negative charges of SAMs, and increased after forming protein by 11.5% at

The purpose of this paper is to discuss about how the logistics strategy must be carried out when it used as a means of management strategy in retailing. Therefore, in this study I showed some problems of logistics strategy for retailing by theory and case study. As the result, it concluded that building a supply chain logistics system for customer satisfaction by utilizing information technology is effective. In the future, to be successful logistics strategy of retailing, we must build an environmentally harmonious logistics system by utilizing information technology and improving the logistics system.

The mechanism of senescence-associated cytoplasmic induction of p-Erk1/2 (SA-p-Erk1/2) proteins in human diploid fibroblasts was investigated. p-Erk1/2 proteins were efficiently dephosphorylated in vitro by protein phosphatases 1 and 2A (PP1/2A) and MAPK phosphatase 3 (MKP3). Specific activity of PP1/2A and MKP3 activity significantly decreased during cellular senescence, whereas their protein expression levels did not. To investigate possible mechanism of phosphatase inactivation, we measured reactive oxygen species (ROS) generation by fluorescence-activated cell sorting analysis and found it was much higher in mid-old cells than the young cells. Treating the young cells once with 1 mm H2O2 remarkably induced p-Erk1/2 expression; however, it was transient unless repeatedly treated until 72 h. Multiple treatment of the cells with 0.2 mm H2O2 significantly duplicated inactivation of PP1/2A; however, thiol-specific reagents could reverse the PP1/2A activities, suggesting the oxidation of cysteine molecule in PP1/2A by the increased ROS. When the cells were pretreated with 10 mm N-acetyl-l-cysteine for 1 h, Erk1/2 activation was completely blocked. To elucidate which cysteine residue and/or metal ion in PP1/2A was modified by H2O2, electrospray ionization-tandem mass spectrometry analyses were performed with purified PP1C-alpha and found Cys62-SO3H and Cys105-SO3H, implicating the tertiary structure perturbation. H2O2 inhibited purified PP1C-alpha activity by both oxidation of Cys residues and metal ion(s), evidenced by dithiothreitol and ascorbate-restoration assay. In summary, SA-p-Erk1/2 was most likely due to the oxidation of PP1/2A, which resulted from the continuous exposure of the cells to vast amounts of ROS generated during cellular senescence by oxidation of Cys62 and Cys105 in PP1C-alpha and metal ion(s).

The synthesis, spectroscopic characterization, and potentiometricmeasurements of new 1,3,5-trisphenoxy-2,4,6-triethylbenzenesare described. The cation binding abilities oftrisphenoxy-2,4,6-triethylbenzenes were strongly dependenton the substituents introduced on the phenoxy units: thereceptors with electron-donating alkoxy groups (–OCH3and –OCH2C6H5) provided similar potentiometricperformance to that of nonactin in PVC-based, ion-selectivemembrane electrodes. The trisphenoxy-2,4,6-triethylbenzenereceptors with ether groups on ortho and meta positions ofphenoxy units exhibit almost identical cation recognitionproperties in the PVC membranes. It is postulated that theelectron-donating nature of the alkoxy substituents increases theelectron density in the phenoxy units, resulting in increasedcation-π interactions.

[reaction: see text] A novel C3V-symmetric scaffold, trindane 7, has been efficiently synthesized from 1,3,5-tris(bromomethyl)-2,4,6-tris(chloromethyl)benzene (1) in six steps with 47% overall yield. The control of all-syn stereochemistry in the tribenzylation step has been achieved by blocking one side of the trindane ring as metal carbonyl complexes. The potential utility of trindane 7 as a receptor skeleton has been examined with a urea derivative 12 toward several anionic guests.

This paper deals with an architecture of network-based control system using the CAN(Controller Area Network) protocol and its traffic analysis. It is difficult to determine an optimal network-based control architecture for a specific AGV(Autonomous Guided Vehicle) system with a manipulator arm. The fixed number of periodic messages to be occurred is pre-defined in the system. To determine whether the proposed system architecture is effective or not, we perform traffic analysis for the real-time communication of all messages. Through simulations, the range of transmission speed is found satisfying the required conditions and the permissible number of additional sensors is investigated for improving the system performance, when the sampling periods of analog sensors are determined under fixed condition that the transmission speed is over 500Kbps.

Atypical femoral fracture (AFF) has been widely issued since the American Society for Bone and Mineral Research (ASBMR) taskforce stated a possible association with long-term use of bisphosphonate in 2010. ASBMR taskforce recommended to include Paget’s disease as one of variables to investigate the AFF in 2010. On the other hand, the ASBMR taskforce in 2014 excluded Paget’s disease in the definition of AFF. Still, any rationale has been barely documented about this change. We described the rationale by reporting an 85-year-old man who had a subtrochanteric fracture with features of atypical femoral fracture which turned out to be Paget’s disease of bone in the pathology.

We previously showed that senescent cells respond to TPA with translocation of senescence associated-pErk1/2 (SA-pErk1/2) into nuclei along with reversal of senescence morphology. Here, we describe that the reversal of senescence phenotype was manifested by knockdown of cytoplasmic PEA-15 expression, a sequestrator of cytoplasmic pErk1/2. Transfection of short-interfering RNA to PEA-15 (siPEA-15) significantly induced nuclear translocation of SA-pErk1/2, and siPEA-15 with TPA co-treatment further increased the translocation. Moreover, the reversal of senescence phenotype, such as expressions of SA-β-galactosidase, p53, p21(WAF1), PML body, 53BP1 and H3K9me2, was modified by either knockdown of PEA-15 or TPA treatment, indicating that nuclear translocation of SA-pErk1/2 might inhibit senescence progression. Indeed, knockdown of PEA-15 or TPA treatment significantly induced progression of G1 arrested cells to S-phase in human diploid fibroblast (HDF) senescent cells, examined by immunocytochemistry, FACS and immunoblot analyses. In conclusion, downregulation of PEA-15 expression reverses senescence phenotypes via nuclear translocation of SA-pErk1/2, which suggests in vivo maintenance of senescence phenotype by sequestration of pErk1/2 in cytoplasm.

Diabetes is a pandemic disease with a higher occurrence in minority populations. The molecular mechanism to initiate diabetes-associated retinal angiogenesis remains largely unknown. We propose an inflammatory pathway of diabetic retinopathy in which macrophages in the diabetic eye provide TGFβ to retinal endothelial cells (REC) in the retinal microvasculature. In response to TGFβ, REC synthesize and secrete a pro-apoptotic BIGH3 (TGFβ-Induced Gene Human Clone 3) protein, which acts in an autocrine loop to induce REC apoptosis. Rhesus monkey retinal endothelial cells (RhREC) were treated with dMCM (cell media of macrophages treated with high glucose and LDL) and assayed for apoptosis (TUNEL), BIGH3 mRNA (qPCR), and protein (Western blots) expressions. Cells were also treated with ΤGFβ1 and 2 for BIGH3 mRNA and protein expression. Inhibition assays were carried out using antibodies for TGFβ1 and for BIGH3 to block apoptosis and mRNA expression. BIGH3 in cultured RhREC cells were identified by immunohistochemistry (IHC). Distribution of BIGH3 and macrophages in the diabetic mouse retina was examined with IHC. RhRECs treated with dMCM or TGFβ showed a significant increase in apoptosis and BIGH3 protein expression. Recombinant BIGH3 added to RhREC culture medium led to a dose-dependent increase in apoptosis. Antibodies (Ab) directed against BIGH3 and TGFβ, as well as TGFβ receptor blocker resulted in a significant reduction in apoptosis induced by either dMCM, TGFβ or BIGH3. IHC showed that cultured RhREC constitutively expressed BIGH3. Macrophage and BIGH3 protein were co-localized to the inner retina of the diabetic mouse eye. Our results support a novel inflammatory pathway for diabetic retinopathy. This pathway is initiated by TGFβ released from macrophages, which promotes synthesis and release of BIGH3 protein by REC and REC apoptosis.

This paper describes the design of a new 1-axis torque sensor that consists of two different type spokes. The sensor has three trapezoidal shape spokes and three support spokes. It serves a double purpose that the sensitivity and stiffness for driving torque. We suggest trapezoid-typed spokes rather than conventional rectangular-typed spoke for sensitivity, and support spokes are used to tolerate to decrease the deformation. The sensor is verified by finite element model analysis and experiments. The result showed the linear relationship between the applied weight and the measured value.

Reactive oxygen species (ROS)-mediated formation of mixed disulfides between critical cysteine residues in proteins and glutathione, a process referred to as protein S-glutathionylation, can lead to loss of enzymatic activity and protein degradation. Since mitochondria are a major source of ROS and a number of their proteins are susceptible to protein-S-glutathionylation, we examined if overexpression of mitochondrial thioltranferase glutaredoxin 2a (Grx2a) in macrophages of dyslipidemic atherosclerosis-prone mice would prevent mitochondrial dysfunction and protect against atherosclerotic lesion formation.We generated transgenic Grx2aMac(LDLR-/-) mice, which overexpress Grx2a as an EGFP fusion protein under the control of the macrophage-specific CD68 promoter. Transgenic mice and wild type siblings were fed a high fat diet for 14 weeks at which time we assessed mitochondrial bioenergetic function in peritoneal macrophages and atherosclerotic lesion formation. Flow cytometry and Western blot analysis demonstrated transgene expression in blood monocytes and peritoneal macrophages isolated from Grx2aMac(LDLR-/-) mice, and fluorescence confocal microscopy studies confirmed that Grx2a expression was restricted to the mitochondria of monocytic cells. Live-cell bioenergetic measurements revealed impaired mitochondrial ATP turnover in macrophages isolated from Grx2aMac(LDLR-/-) mice compared to macrophages isolated from non-transgenic mice. However, despite impaired mitochondrial function in macrophages of Grx2aMac(LDLR-/-) mice, we observed no significant difference in the severity of atherosclerosis between wildtype and Grx2aMac(LDLR-/-) mice.Our findings suggest that increasing Grx2a activity in macrophage mitochondria disrupts mitochondrial respiration and ATP production, but without affecting the proatherogenic potential of macrophages. Our data suggest that macrophages are resistant against moderate mitochondrial dysfunction and rely on alternative pathways for ATP synthesis to support the energetic requirements.

The objective of this investigation was to determine the prevalence and characteristics of extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae in ready-to-eat (RTE) vegetables. A total of 189 RTE vegetable samples (91 sprouts and 98 mixed salads) were collected in a retail market in South Korea from October 2012 to February 2013. The prevalence of ESBL-producing E. coli and K. pneumoniae was 10.1%. Of these, 94.7% were from the sprout samples. All isolates were resistant to cefotaxime, and many of the ESBL producers were also resistant to non-β-lactam antibiotics, including gentamicin, trimethoprim/sulfamethoxazole, and ciprofloxacin (73.7%, 63.2%, and 26.3% respectively). TEM-1, SHV-1, -2, -11, -12, -27, -28 and -61, and CTX-M-14, -15 and -55 β-lactamases were detected alone or in combination. The genetic platforms of all CTX-M producing isolates were ISEcp1-blaCTX-M-orf477 and ISEcp1-blaCTX-M-IS903 in CTX-M groups 1 and 9, respectively. To our knowledge, this is the first report of the prevalence and characterization of ESBL-producing E. coli and K. pneumoniae isolated from RTE vegetables. The results of this study indicate that RTE vegetables, sprouts, in particular, may play a role in spreading antimicrobial resistant bacteria and ESBL genes to humans.

In this study, the size dependence of metal sheet on the plastic deformation behavior was investigated in microscale deep drawing process. In order to perform deep drawing experiments, a tooling system was first developed. Then, a series of microscale deep drawing experiments were performed in various process conditions. The blank holder gap between the blank and blankholder was controlled to eliminate the possible defect such as wrinkling. In particular, the effects of feature size were analyzed by comparing the normalized deformation loads at different values of the scale factor λ. It was found that the maximum value of the normalized deformation load and the failure instant were strongly influenced by the feature size of metal sheet.Copyright © 2014 by ASME

A chemosensor compound (1) consisting of a central ferrocene with two butylaminomethyl arms showed unexpected facile electrochemical oxidation of the secondary amines in proximity to the ferrocene, which was utilized for electrochemical discrimination of phthalic acid selectively over two other isomers, isophthalic acid and terephthalic acid.

Purpose To assess the accuracy of 3 corneal horizontal meridian marking techniques using the iTrace Surgical Workstation in preoperative assessment for toric intraocular lens (IOL) implantation. Setting Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea. Design Prospective comparative observational study. Methods Patients were allocated into 3 groups. Three techniques—marking with a nonpendular marker with a surgeon's direct visualization, slitlamp-assisted marking with a pendulum-attached marker, and slitlamp-assisted marking with a horizontal slit beam—were used to perform the horizontal meridian marking. The marks were immediately documented and aligned with the Zaldivar toric caliper transparent topographic map. Using a horizontal reference meridian determined by the toric caliper, the accuracy of corneal horizontal marking techniques was quantitatively evaluated by determining the rotational deviation and vertical misalignment. Results For rotational deviation, the pendular marking showed the fewest errors to the horizontal reference meridian (mean error −0.66 degrees; mean absolute error [MAE] 3.77 degrees). There was a significant difference between the pendular marking and the surgeon's direct visual marking. For the MAE, the pendular marking showed less deviation than the surgeon's direct visual marking and the horizontal slit-beam marking. With vertical misalignment, there was no significant difference between the 3 different corneal horizontal meridian marking techniques. Conclusion The slitlamp-assisted technique with the pendulum-attached marker was more precise than marking with a nonpendular marker with a surgeon's direct visualization and marking with a horizontal slit beam in preoperative assessment for toric IOLs. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

This paper proposes a novel compensation method for shadow areas on the human face by analyzing magnitude components of the facial images on the Fourier domain. A feature extraction algorithm based on PCA+LDA is utilized to extract features of the magnitude components, and create a compensation handling mask which identifies and catalog the necessary compensation levels of darkness pixels. The proposed algorithm is applied to the facial data for the face recognition. The experimental results demonstrate that the proposed algorithm can effectively compensate for the dark areas in the human image as well as improve the accuracy of face recognition.

3α-Hydroxy-23,24-bisnorcholane spermidine and spermine carbamates 2–7 have been synthesized and their antimicrobial and hemolytic activities were evaluated. They exhibited excellent in vitro activities especially against methicillin-resistant Staphylococcus aureus.

To clarify the sequential changes in pRB and p16 during different stages of hepatocarcinogenesis such as fibrosis, cirrhosis, hepatocellular adenoma (HCA), and hepatocellular carcinoma (HCC), male Fischer 344 rats were singly injected with diethylnitrosamine (DEN), immediately followed with phenobarbital for 1 wk and then thioacetamide (TAA) for 39 wk in drinking water. Rats were killed at 9, 20, 30, and 40 wk after DEN initiation and changes of pRB level, p16 gene hypermethylation, and in vivo gankyrin expression were examined. Histologic examination showed stepwise appearances of fibrosis, cirrhosis, HCA, and HCC at weeks 9, 20, 30, and 40, respectively. Hypermethylation of p16 exon 1 was not found until HCA but appeared in 50% of the rats with HCC accompanied by complete loss of its mRNA expression. The amount of glutathione S-transferase–gankyrin bound to pRB and pRB degradation in the liver depended on the concentration of gankyrin and incubation time. Gankyrin expression preceded pRB degradation in liver cirrhosis. In conclusion, gankyrin expression induced in liver fibrosis accelerated the degradation of pRB during liver cirrhosis, and inactivation of p16 exon 1 by DNA hypermethylation occurred during the progression of tumor cells to poorly differentiated HCC. Inactivation of pRB and/or p16 resulted in complete loss of regulation in the cell-division cycle during early and late stages, respectively, of hepatocarcinogenesis. Mol. Carcinog. 30:138–150, 2001. © 2001 Wiley-Liss, Inc.

Synthesis of 2-pyridylthiazole ethers 2, 3), 4-nonyl-2-pyridylthiazole 4), 2-nonyl-4-pyridylthiazole 5) and 2-pyridylthiazole imine 6), potentially useful as effective cation-binding ligands, is described. The potentiometric properties of ion-selective membranes prepared with 30–32 wt% PVC, 66 wt% 2-nitrophenyloctyl ether and 2–4 wt% pyridylthiazole derivatives have been examined. While the membranes containing 2-pyridylthiazole ethers 1-4) exhibited high selectivity toward silver(I) ion, that prepared with 2-pyridylthiazole imine 6) resulted in negligible potentiometric reponse to most mono- and divalent cations.

The synthesis of 5,6,7,8-tetrahydro-4H-oxazolo[4,5-c]azepin-4-ones 5a,b and 1,3-benzoxazol-4-amines 4a,b are described starting from 4,5,6,7-tetrahydro-1,3-benzoxazol-4-ones. Thionation of 5a,b followed by alkylation with ethyl bromoacetate led to the corresponding S-alkyl azepines 7a,b.

Synthesis and antimicrobial activity of squalamine analogue 2 are reported. The synthesis of 2 was accomplished from bisnoralcohol 3. The spermidine moiety was introduced via reductive amination of an appropriately functionalized 3beta-aminosterol with spermidinyl aldehyde 17 utilizing sodium triacetoxyborohydride as the reducing agent. Compound 2 shows weaker antimicrobial activity than squalamine.

An implantation of phosphorus is used in tungsten polycide gate process, and the effects of implantation on the reduction of resistance and characteristics of GOI (Gate Oxide Integrity) were investigated. The sheet resistance of gate electrode decreases with increase of phosphorus implant dose and energy as increase of grain size. The depletion effects of gate polysilicon at reverse biases were found in unimplanted tungsten polycide gate due to the out-diffusion of dopant atoms in buffer polysilicon layers during activation anneals. However, the depletion effects of gate polysilicon were effectively suppressed by the implantation of phosphorus. The lifetime of gate oxide was degraded several orders of magnitude for the high-energy implanted samples. Therefore, there is optimum energy for phosphorus implantation into gate electrode to improve the resistance of tungsten polycide gate electrode and the depletion effects of gate polysilicon.

Free methionine-(R)-sulfoxide reductase (fRMsr) catalyzes the reduction of the free form of methionine-(R)-sulfoxide back to free methionine. The fRMsr protein from Staphylococcus aureus was overexpressed in Escherichia coli, purified and crystallized at 295 K using ammonium sulfate as a precipitant. Diffraction data were collected to 1.7 angstrom resolution from a native crystal using synchrotron radiation. The crystal belonged to the hexagonal space group P6(1)22, with unit-cell parameters a = b = 89.84, c = 88.75 angstrom, alpha = beta = 90, gamma = 120 degrees. Assuming the presence of one molecule in the asymmetric unit, the calculated Matthews coefficient value was 2.21 angstrom(3) Da(-1), with a solvent content of 57.1%.

The spinel ferrite NiCrxFe2−xO4 system was synthesized under atmospheric pressure, and showed single spinel phase in the XRD pattern. The lattice parameter decreased with increasing amount of Cr. For the study of cation distribution in this system, magnetic measurements and Mossbauer spectroscopy were carried out. It was found that ions at the B site moved to the A site, and that this system varied from an inverse to a normal spinel structure. It was observed that the magnetic moment of the systems and Curie Temperature decreased by substitution effect. Using a thermopower measurement, this system was found to exhibit n-type semiconductivity. In the electrical conductivity measurements, an abrupt change exists near the Tc, owing to the magnetic spin arrangement relaxation. The electrical conduction mechanism of spinel is an electron transfer between the +2 and +3 cations at the B site, so called polaron hopping mechanism. From the conductivity result, this system is closely related to the electron-hole-compensation between electrons and holes.

Crown ethers containing a thiazole subcyclic unit are prepared from the reactions of 1,3-bis[2(4-hydroxymethylthiazoyl)]benzene with di-p-tosylates of corresponding di, tri, tetra, pentaethylene glycols in the presence of potassium hydride. However, if the cavity size in the ring system is small, [2+2] cyclization adduct also is formed.

A new series of chiral C 2 -symmetric bisferrocenyldiimine 1 and bisferrocenyldiamines 2 and 3 proved to be efficient ligands for the copper(I)-catalyzed asymmetric cyclopropanation, cyclopropenation, and aziridination of alkenes and alkynes to give high diastereo- and enantioselectivity as well as high chemical yields. In some instances the enantiomeric excesses of cyclopropanated products are among the highest (>97% ee) ever reported. Comparative studies show that stereoselectivity depends highly on the steric variation both in the ligand and the substrate. Other transition metal complexes incorporating some of these ligands such as Ru( 3c )Cl 2 , [(NBD)Rh( 2 )]ClO 4 , [Cu( 2 )(MeCN) 2 ]PF 6 , and Pd( 2 )Cl 2 also demonstrated high enantioselectivity in cyclopropanation reactions.

Co1−xMnxFe2O4 spinels were synthesized at 1080°C in air as bulk phases. The lattice parameters increase with the addition of Mn cation, which is closely related to the effective substitution of Mn2+ cation. From the measurements of the magnetic moment, it is shown that Mn contributes to the canted magnetic moment between tetrahedral (A) and octahedral (B) sites, except for the sample with x = 0.2. The n-type conduction was observed from Seebeck coefficient measurements: this is ascribed the formation of Co3+ + e− and Mn3+ + e− from Co2+ and Mn2+ cations on A and B sites. The electrical conductivities increase with Mn substitution. It is suggested that the possibility of charge transfer between 2+ and 3+ cation in A as well as B sites may contribute to electrical conductivity.

Polypyrrole perchlorate (PPy-ClO 4 ) has been prepared by electrochemical polymerization in an acetonitrile solution. We present the results of extensive measurements on the physicochemical properties of the PPy-ClO 4 films by electrical, magnetic, electrochemical, and thermal analysis. Cyclic voltammetry demonstrates that both of the peak current and potential strongly depend on the scan rate, implying the electrode reaction process of PPy-ClO 4 is irreversible. Thermal analyses by thermogravimetric analysis (TGA) and by differential thermal analysis (DTA) show that a weight loss occurs between 250–320°C with a glass transition temperature T g ≈268°C, which is much higher than the previous works. The temperature dependence of the electrical conductivity, σ ( T ), is presented and analyzed using several models. The results demonstrate that the transport properties of PPy-ClO 4 can be described well by ln[ σ ( T ) T 1/2 ] vs. T −1/4 plot, corresponding to the phonon-assisted hopping process for the charge carriers. We discuss the implication of the data in relation with the microscopic and morphological structure of the samples.

Superconductor Bi2Pb1 − xSnxSr2Ca2Cu3Oy (x = 0.0, 0.05, 0.08, 0.1, 0.2 and 0.3) samples were prepared by the conventional solid state reaction and analyzed by XRD, SEM, TGA and DSC and their resistivities were measured by standard ac four-probe method. When a small quantity of Sn (x < 0.1 ) was added, it was found from the SEM and XRD results that high-Tc phase occurred preferentially and the critical temperature was elevated. With the results of XRD, EDX, DSC and TG, it was concluded that a small amount of Sn promotes the formation of liquid phase, which makes the weak link of grain boundary better. When a large amount (x ≥ 0.1) of Sn was added to the (Bi,Pb) 2223 system, however, the solid state reactions became more important than liquid phase-assisted reactions. Thus, the reaction rate decreased and there is no longer a significant role of tin on the formation of 2223 phase in that region (0.1 ≤ x ≤ 0.3).

Poly(pyrrole hexafluorophosphate) (PPPF 6 ) was prepared with the potentiostatic method to supply a constant potential of 1.21 V for 5 h in water/acetonitrile (1/99 vol %) solution of 0.2M pyrrole containing 0.1M tetraethylammonium hexafluorophosphate as a supporting electrolyte. The result of elemental analysis and Fourier transform infrared spectrum showed that it was a PPPF 6 that was doped with ∼28 wt % PF 6 - . From the cyclic voltammogram, it was found that the redox reaction of PPPF 6 was irreversible. Scanning electron microscopy was performed to know the morphology of PPPF 6 . The result of the differential scanning calorimetry did not show any special peak in temperature range of 25-800°C. From the temperature dependence of the electrical conductivity and electron spin resonance measurement, it was suggested that a possible conduction mechanism for the PPPF 6 polymer should be a small polaron hopping conduction.

A study of annealing effects on micro-structures and electrical properties of an initially amorphous silicon gate and of thin gate oxide was carried out. The amorphous silicon gate was crystallized by post gate anneal. As the annealing temperature increases, the resistivity of gate decreases due to the increase of dopant activation rate. The strong compressive stress in amorphous silicon gate is relaxed as the micro-structure of the gate changes to polycrystalline silicon. The electrical properties of thin gate oxide are improved by post gate anneal at higher temperatures. The leakage current decreases and the breakdown characteristics of the thin gate oxide are greatly improved. Particularly, the interface trap density at oxide/silicon decreases with the increase of annealing temperature, which is consistent with the behavior of polycrystalline silicon gate stress.

ZnSnxFe2−4x/3O4 spinels (0.0 ≤ x ≤ 0.3) which have cubic symmetry were synthesized using a ceramic technique at 1150°C for 24 h in air and rapidly quenched to room temperature. From the XRD. TGA and DTA results, it was found that all samples had single phase and thermal stability in the range of room temperature up to 1000 K. As Sn4− concentration was increased from x = 0 to 0.3, the lattice parameter and electrical conductivity increased. The results of Mossbauer spectroscopy and magnetic moment measurements showed that the tetrahedral (A) site is occupied by a Zn+ ion and magnetic moments depend only upon Fe3+ ion in an octahedral (B) site. The magnetic moments decreased with an increasing amount of non-magnetic Sn (d10) ion. n-type semiconductivity was observed in all samples. However, the conductivities did not depend on Sn substitution. It was assumed that the conduction mechanism would be derived from the competitive relation between the formation of Fe2+ and elongation of distance between neighboring Fe cations.