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As a mitotic-specific target widely deregulated in various human cancers, polo-like kinase 1 (Plk1) has been extensively explored for anticancer activity and drug discovery. Although multiple catalytic domain inhibitors were tested in preclinical and clinical studies, their efficacies are limited by dose-limiting cytotoxicity, mainly from off-target cross reactivity. The C-terminal noncatalytic polo-box domain (PBD) of Plk1 has emerged as an attractive target for generating new protein–protein interaction inhibitors. Here, we identified a 1-thioxo-2,4-dihydro-[1,2,4]triazolo[4,3-a]quinazolin-5(1H)-one scaffold that efficiently inhibits Plk1 PBD but not its related Plk2 and Plk3 PBDs. Structure–activity relationship studies led to multiple inhibitors having ≥10-fold higher inhibitory activity than the previously characterized Plk1 PBD-specific phosphopeptide, PLHSpT (Kd∼ 450 nM). In addition, S-methyl prodrugs effectively inhibited mitotic progression and cell proliferation and their metabolic stability was determined. These data describe a novel class of small-molecule inhibitors that offer a promising avenue for future drug discovery against Plk1-addicted cancers.

Shiga toxin-producing Escherichia coli(STEC) are critical foodborne pathogens, which cause serious human health issues, including hemolytic uremic syndrome. Illnesses caused by STEC lack effective treatments that target the elimination of these bacteria from the gastrointestinal tract without causing an adverse effect. Reducing this pathogen from a reservoir of STEC is an effective strategy, but the challenges remain due to the lack of efficient, selective antimicrobial agents. We developed specific antibody-conjugated chitosan nanoparticles (CNs) to selectively target and treat STEC in the gastrointestinal tract. Given the great broad-spectrum antimicrobial activity of CN, we conjugated antibodies to CN. Antibodies were raised and purified from egg yolks after immunization of hens with seven different O-side-chain antigens isolated from STEC (O26, O45, O103, O111, O121, O145, and O157). We prepared CN-immunoglobulin Y (IgY) conjugates by forming amide bonds at different ratios of CN:IgY (10:1, 10:2, and 10:4). The CN-IgY conjugated at a 10:2 ratio demonstrated significantly enhanced antimicrobial activity against E. coliO157:H7. Conjugates of CN and anti-STEC IgY antibodies killed corresponding STEC serotypes specifically and selectively, while showing no significant impact on nontargeted bacteria, including Salmonella entericaand Lactobacillus plantarum. The enhanced antimicrobial activity of CN-IgY against STEC was also confirmed in synthetic intestinal fluid, as well as an in vivo animal model of Caenorhabditis elegans. These results suggest that the CN-IgY conjugates have strong and specific antimicrobial activity and that they are also great candidates to eliminate pathogens selectively in the gastrointestinal tract without inhibiting beneficial bacteria.

In the current investigation, an ultrasonic imaging system originally developed for visualization of microstructures in sheet metals, with capabilities of generating plane two-dimensional images at spatial resolutions between 1 and 200 μm, was used to quantitatively evaluate a Fused Filament Fabrication (FFF) processed 3D test part. For the ultrasonic system, a custom software program was written to control all components of the inspection schemes in a continuous scan mode, including the movement of three orthogonal translational stages, as well as display a live ultrasonic image during scanning and provide tools for advanced post-processing of the recorded ultrasonic signals. Prior to collecting ultrasonic data for a selected test specimen, an optical flat reference standard was used to characterize the ultrasonic probes and to quantify the system’s mechanical stability, repeatability, and accuracy when measuring the physical dimensions of features. Ultrasonic data collected at different spatial resolutions were used to characterize a part’s surface flatness, internal defects, and fusion conditions; and to measure the physical dimensions of intended features. To validate the accuracy of the ultrasonic internal characterization, one side panel of the test specimen was removed for visual confirmation, and additional ultrasonic data was collected and compared to the original data. Finally, a suggestion is made for adopting a process to qualify or certify FFF based additive manufacturing machines in the market by applying a reliable NDE validation method to a standardized part with various features of different shapes and physical dimensions.

Hypersensitivity reactions to pine nuts in children have been occasionally encountered recently, although reports on pine nut allergy cases are rare worldwide. The study aimed to feature clinical and laboratory findings pertaining to pine nut allergy in Korean children.

Musashi RNA-binding protein 2 (MSI2) has important roles in human cancer. However, the regulatory mechanisms by which MSI2alters breast cancer pathophysiology have not been clearly identified. Here we demonstrate that MSI2 directly regulates estrogen receptor 1 (ESR1), which is a well-known therapeutic target and has been shown to reflect clinical outcomes in breast cancer. Based on gene expression data analysis, we found that MSI2 expression was highly enriched in estrogen receptor (ER)-positive breast cancer and that MSI2 expression was significantly correlated with ESR1 expression, including expression of ESR1 downstream target genes. In addition, MSI2 levels were associated with clinical outcomes. MSI2 influenced breast cancer cell growth by altering ESR1 function. MSI2 alters ESR1 by binding specific sites in ESR1 RNA and by increasing ESR1 protein stability. Taken together, our findings identified a novel regulatory mechanism of MSI2 as an upstream regulator of ESR1 and revealed the clinical relevance of the RNA-binding protein MSI2 in breast cancer.

Rab coupling protein (RCP)-induced tumor cell migration has been implicated in tumor pathophysiology and patient outcomes. In the present study, we demonstrate that RCP stabilizes β1 integrin leading to increased β1 integrin levels and activation of a signaling cascade culminating in Slug induction, epithelial-to-mesenchymal transition and increased invasion. Ectopic expression of RCP induced Slug expression. Silencing β1 integrin efficiently inhibited RCP-induced Slug expression and subsequent cancer cell invasion. Conversely, ectopic expression of β1 integrin was sufficient to induce Slug expression. Pharmacological inhibition of integrin linked kinase (ILK), EGFR and NF-κB, as well as transfection of a dominant-negative mutant of Ras (RasN17), significantly inhibited RCP-induced Slug expression and cancer cell invasion. Strikingly, ectopic expression of RCP was sufficient to enhance metastasis of ovarian cancer cells to the lung. Collectively, we demonstrate a mechanism by which RCP promotes cancer cell aggressiveness through sequential β1 integrin stabilization, activation of an ILK/EGFR/Ras/NF-κB signaling cascade and subsequent Slug expression.

The original version of this article contained an error in the published figures Fig 2 and Fig 3f, where the information was inadvertently duplicated. This error does not alter the conclusions of the paper. The corrected figures are published in this correction notice. The authors sincerely apologize for this error.

We present the first results of a CO(2–1), (1–0), and 86 GHz SiO  maser survey of AGB stars, selected by their weak near-infrared excess. Among the 65 sources of the present sample we find 10 objects with low CO outflow velocities, $v_{\rm exp} \la 5\,$km s-1. Typically, these sources show (much) wider SiO maser features. Additionally, we get 5 sources with composite CO line profiles, i.e. a narrow feature is superimposed on a broader one, where both components are centered at the same stellar velocity. The gas mass-loss rates, outflow velocities and velocity structures suggested by these line profiles are compared with the results of hydrodynamical model calculations for dust forming molecular winds of pulsating AGB stars. The observations presented here give support to our recent low outflow-velocity models, in which only small amounts of dust are formed. Therefore, the wind generation in these models is dominated by stellar pulsation. We interpret the composite line profiles in terms of successive winds with different characteristics. Our hydrodynamical models, which show that the wind properties may be extremely sensitive to the stellar parameters, support such a scenario.

A Fresnel zone plate based SPEM (scanning photoelectron microscope) is in operation at the Pohang Light Source. Space resolution of the SPEM is typically, $\lesssim $1 μm (0.4 μm in the best resolution) and the photon flux at the focused spot is ~109photons/s. The SPEM is working in the energy range between 400 and 1,000 eV. In taking images and spectra, the SPEM detects photoelectrons from the focused spot using a hemispherical analyzer with 16-channel detection capability at energy resolution of ~0.5 eV. The SPEM also measures sample current, with which comparative x-ray absorption micro-spectroscopy is available in limited energy range with spectral resolving power (E/ΔE) of ~3,000. The advantage of detecting sample current image and x-ray absorption spectrum at the Fe Llll,-edge is demonstrated for understanding the effect of electrochemically deposited Zn layer on Fe substrate.

Recent hydrodynamical models (Winters et al. 2000b) allow the existence of pulsating, large velocity amplitude Asymptotic Giant Branch (AGB) stars with tenuous dusty circumstellar shells, which produce low mass-loss rates and simultaneously low wind velocities. The Semi-regular long-period variable L2Pup shows a broad SiO maser feature at 86 GHz ($v=1$, $J=2{-}1$), indicating an outward velocity of the material close to the stellar photosphere of at least 10 km s-1, and narrow CO ($J=2{-}1$) and (1-0) line profiles indicating an outflow velocity of the material in the circumstellar shell of only about 3 km s-1. This can be explained in terms of our hydrodynamical models which provide large velocities in the shocked stellar atmosphere and low velocities of the circumstellar outflow.

Anomalous changes in the ionospheric conditions related to the Wenchuan earthquake of 12 May 2008 are investigated using electron density (Ne) from Detection of Electro‐Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) and CHAMP satellites, electric field from DEMETER, and GPS‐total electron content (TEC) maps. The normalized Nefrom the DEMETER satellite reveal that the previously reported TEC increments before the earthquake can be considered as fragments of the gradual equatorial ionization anomaly (EIA) enhancements near the epicenter longitude that began approximately 1 month before the earthquake and reached its maximum with an exceptionally large strength index 8 days prior to the main shock. This feature is indirectly confirmed through the CHAMP Neand GPS TEC data. Following the EIA intensity peak, disturbances in the Neand O+density were observed in the nightside. Based on the concurrent electric field and Nechanges, it is suggested that EIA intensification could be triggered by the Efield disturbances over the epicenter. Ionospheric disturbances before the Wenchuan earthquake are analyzedThe TEC increase is revealed as the gradual EIA enhancementsThe nighttime data provide clues about geometry of seismo‐ionospheric coupling

Multilayer films composed of alternating layers of Bi and Se[Bi(4.55 Å)/Se(6.82 Å)]n(Bi4Se6), [Bi(6.13 Å)/Se(12.26) Å]n(Bi6Se12), and [Bi(4.86 Å)/Se(18.46 Å)]n(Bi4Se18)were fabricated by controlling the layer thickness at the atomic scale using thermal evaporation techniques. After annealing treatment, the Bi4Se18 alternately layered film shows a single phase of Bi2Se3rhombohedral crystalline structure with the characteristic density of single crystal Bi2Se3, whereas the Bi6Se12 and Bi4Se6 films show locally disordered Bi2Se3crystalline structure. The effectively controlled layered structure in the as-grown Bi4Se18 film enhances the Bi–Se chemical bonding state. The formation of a layered crystalline structure during the annealing process increased as the thickness of Se increased. After interdiffusion and the crystallization process, alternately layered Bi4Se18 films become stable Bi2Se3single crystals with a continuous and uniform layered structure. Finally, in the Bi–Se system, atomically controlled multilayers with an optimized ratio of each unit layer can be transformed to a perfect single-crystalline structure on oxidized Si with an amorphous phase through a self-organized ordering process.

Digital holography, Fourier optics and speckle are combined to enable a new direction in drug discovery. Optical coherence imaging (OCI) is a coherence-gated imaging approach that captures dynamic speckle from inside living tissue. The speckle temporal fluctuations arise from internal motions in the biological tissue, and the changes in these motions caused by applying drugs can be captured and quantified using tissue dynamics spectroscopy (TDS). A phenotypic profile of many reference drugs provides a training set that would help classify new compounds that may be candidates as new anti-cancer drugs.

Nafion/inorganic (inorganic = S-ZrO2, SiO2-SO3H, SBA-15-SO3H, MCM-41-SO3H, and P-Si gels) composite membranes were synthesized with the goal of increasing the proton exchange membrane (PEM) fuel cell performance at elevated temperatures up to 120degC and reduced relative humidity (RH) down to 25%. Inorganic materials were incorporated within the Nafion by three different techniques. The conductivity of composite membranes with sulfonated inorganic materials was not higher than the conductivity of the recast Nafion in the whole range of inorganic loading. Conductivity of the Nafion/P-Si gel membranes was affected by the surface of inorganic powders and was higher for membranes prepared by in situ formation techniques. At 120degC and 70% RH, the conductivity of some composite membranes reached 100 mS cm[?]1. Effect of the inorganic phase on the membrane performance in a fuel cell was much stronger than on its conductivity probably due to substantial improvement in membrane water retention properties. At 120degC and 50% RH, the cell resistance of the P-Si composite membrane was found to be 40% lower than that of Nafion. By applying the modified rule of mixtures, the composite proton conductivity was calculated and compared with experimental data.

Polyester resin based glass fiber reinforced composite panels obtained from a local windmill turbine blade part manufacturing company are used to evaluate the performance of inter-digital transducer (IDT) surface wave transducers. Interaction of surface waves with fiberglass layers is addressed in this work. Additionally, artificially created flaws such as cracks, impact damage and delamination are also studied in terms of amplitude changes in order to attempt to quantify the size, location and severity of damage in the test panels. As a potential application to the structural health monitoring (SHM) of windmill turbine blades, the coverage distance within the width of the sound field is estimated to be over 80 cm when a set of IDT sensors consisted of one transmitter and two receivers in a pitch-catch mode.

The article discusses the application of structural stress based analysis procedure in tubular joints varying from simple T joints, double T joints and K joints with internal stiffening configurations. Fatigue design of tubular joints in offshore structures has been based on surface extrapolation based hot spot stress methods. Structural stresses are calculated by using balanced nodal forces and moments from a solution. The process of converting nodal forces to line force and line moments which characterize the traction conditions is described.

Solder fatigue is one of the major product reliability concerns in electric packaging design. In this paper, the application of a mesh-insensitive structural stress method, previously developed by the authors, is demonstrated for characterizing fatigue of solder joints under thermal fatigue and mechanical fatigue conditions. Three sets of experimental data from literature are analyzed to demonstrate the effectiveness of the structural stress method in its ability to correlate test data over different packaging designs, test methods, etc. As evidenced in this study, the meshinsensitive structural stress method offers a simple but effective means to correlate the fatigue behavior of solder joints among various test conditions. The results show that the structural stress method can be used as an effective alternative to existing methods in the literature, in reliability design of electronic packaging.

Abstract: In Masan Bay, the drainage basin for the wastewater of heavily-industrialized cities and harbors in the southeastern Korea, a composite analysis of sediment cores reveals that accumulation history and behaviors of heavy metals are distinctive depending on anthropogenic activities and dissolved oxygen in water column. In the inner bay, Cu, Zn, and Pb have been enriched, associated with organic and sulfide matter, over background levels since the mid-1940s. It seems to result from the deposition of stream-disposed sewage under a poor water circulation before most of sewage collected in Masan City has been treated and disposed through an outfall into the outer bay since the late 1993. The outfall disposal contaminated the topmost sediments of the outer bay with the three metals, 2.2 to 3.2 times as much as the background. The three metals are strongly associated with Mn in the bay mouth, probably resulting from their oxidative precipitation beneath a chemical front of water column that forms by expansion and mixing of anoxic bay bottom water with oxygenated coastal water. The bay sediments seem to act as a mobile pool in that Mn and the pollutant metals are often remobilized to the anoxic bottom water in summer.

At present, the electronic packaging industry is actively searching for lead‐free (Pb‐free) solders due to environmental concerns over Pb‐containing solders. For a successful transition to Pb‐free manufacturing in electronics assembly, it is critical to understand the behavior of Pb‐free solders. We report the surface oxidation mechanism of Pb‐free solder in this paper. This mechanism has been investigated after using X‐ray photoelectron spectroscopy.

A series of new asymmetric bent main-chain liquid crystalline (LC) polyesters (BPE-Cn) were synthesized through the condensation polymerization of A−B type asymmetric α,ω-carboxylic acid−hydroxyl-terminated monomers containing different even numbers of methylene spacers (BPCA-Cn-PmOH, where n = 6, 8, and 10). Differential scanning calorimetry results showed three phase transition processes in this series of BPE-Cn samples. The phase change with the lowest transition temperature is cooling rate dependent, while the two higher temperature transitions are cooling rate independent. One-dimensional (1D) powder wide-angle X-ray diffraction (WAXD) results at different temperatures revealed that during cooling this series of polymers exhibits a low-ordered LC phase and a highly ordered smectic crystal phase before developing a crystalline phase at lower temperatures. The phase structures and symmetry were identified by 2D WAXD and selected area electron diffraction (SAED). On the basis of 2D fiber WAXD patterns, the low ordered LC phase was identified to be an anticlinically tilted SmC (SmCA) phase, which was constructed by an alternating synclinic SmC phase in each chemical repeating unit layer along the fiber drawn direction. The highly ordered smectic phase was an anticlinically tilted SmH (SmHA) phase, which was again constructed by an alternating synclinic SmH phase in neighboring layers. On the basis of the crystallographic point of view, this smectic crystal phase had an orthorhombic unit cell. The crystalline structure was determined to be an orthorhombic unit cell (KO) with Pna21 symmetry in these three polyesters. The crystalline structures and symmetry were also confirmed by SAED experiments. As the number of methylene units increased, the dimensions of the crystal structures also increased, yet they retained a zigzag conformation. A two-chain packing model of the KO phase with four chemical repeating units was proposed on the basis of the experimental diffraction patterns and qualitatively supported by simulated structural diffractions. Additionally, the phase identifications were also supported by the observation of texture changes in polarized light microscopy. Even though the zigzag molecular arrangement remains in the low ordered SmCA and the highly ordered SmHA phases which mimics the bent-core small molecules, chiral characteristics such as helical supramolecular structures are not observed due to the covalent bonding connections in this series of BPE-Cn polymers.

We demonstrate that among the three monofunctional catalases of Pseudomonas aeruginosa PA14, KatA and, to a lesser extent, KatB, but not KatE, are required for resistance to peroxide and osmotic stresses. KatA is crucial for adaptation to H2O2 stress and full virulence in both Drosophila melanogaster and mice. This dismantling of catalase roles represents a specialized catalytic system primarily involving KatA in responses to adverse environmental conditions.

A series of achiral 4-biphenyl carboxylic acid compounds (BPCA-Cn-PmOH) connected with alkoxyl chains having various carbon numbers (n = 6−10) and terminated by phenyl groups with meta-positioned hydroxyl groups was synthesized. Different phase structures including nematic, smectic A (SmA), smectic C (SmC), and highly ordered smectic liquid-crystalline phases along with crystalline phases were identified based on wide-angle X-ray diffraction and electron diffraction experiments. It was found via infrared spectroscopy that the hydrogen (H)-bonds were formed between the carboxylic acids to construct head-to-head dimers as the building blocks for these ordered structural formations. H-bonds formed via the meta-positioned hydroxyl groups also played an important role in forming ordered layers in these structures. The morphology of this series of BPCA-Cn-PmOH as observed under polarized light microscopy showed an oily streak (cylinder) texture with Myelin-figure in the SmA phase. When temperature cools to enter the SmC phase, these streaks (cylinders) started to twist into helical suprastructures, which were not only by the birefringence changes but also by the three-dimensional helical geometry observed in other microscopic techniques. The dynamic conformational changes of the aromatic and aliphatic parts in this series of BPCA-Cn-PmOH at different temperatures correspond well with the thermal transitions via solid-state carbon-13 nuclear magnetic resonance experiments. Computer simulation indicated that the head-to-head dimers possess a twisted rather than a bent conformation. It was deduced that the twisted conformation of the dimers and the terminal meta-substituted phenyl groups at both ends of the dimers are critically important in forming the helical suprastructures.

Self-assembled “supra-molecular” liquid-crystalline phases were investigated in one of a series of symmetrically tapered bisamides based on an amide core of 1,2-bis[3,4,5-tris(alkan-1-yloxy)benzamido]benzene and three alkyl tails on each side of the core. One of this series of bisamides having 14 carbon atoms in each tail (abbreviated as C14PhBA) served as an example in this study. Differential scanning calorimetry thermal diagrams showed two main phase transition processes in C14PhBA. Wide-angle X-ray diffraction results revealed that the high-temperature phase transition is between the isotropic melt (I) and a 2D low-ordered oblique columnar phase (I ↔ ΦOB). The low-temperature phase transition was attributed to the transition between a highly ordered, oblique columnar (ΦOK) phase and the ΦOB phase. Supra-molecular columns were directly visualized using transmission electron microscopy and atomic force microscopy. The formation of these supra-molecular structures is critically dependent upon the construction of building blocks (“columns”) by C14PhBA molecules. These building blocks developed via rigid amide core/alkyl tail micro-phase separation and the hydrogen (H) bond formation between the N−H and carbonyl groups among the cores. Spectroscopic studies showed that the columns were stabilized by intercore H-bonds oriented along the column long axis, and the alkyl tails in the ΦOK phase were packed into an ordered mesophase having about 64% of the methylene carbon atoms in long trans segments at room temperature. In the ΦOB phase, the alkyl tails adopt liquidlike disordered conformations. The high- and low-temperature phase transitions were thus mainly attributed to the sudden changes in H-bonding and alkyl tail conformation, respectively. A detailed packing model of the ΦOK phase was proposed and qualitatively proven using a simulated structural diffraction.

AbstractBackground: Interaction of the integrin leukocyte function-associated antigen (LFA)-1 (CD11a/CD18) with its ligands, the intercellular adhesion molecules (ICAM)-1, -2, and -3 (CD54, CD102, and CD50), is pivotal to many leukocyte adhesion events. Method: To define the mechanism of the movement of leukocytes to the inflammatory site by somatostatin (SOM) and substance P (SP), we examined the expression of the adhesion molecule LFA-1 and inside-out signals for integrins, protein kinase C (PKC), Ras, Rap1, and phosphoinositide (PI) 3-kinase, in anti-CD3-, anti-CD3+SOM-, anti-CD3+SP-stimulated or unstimulated spleen cells. Results: SOM caused down-regulation of LFA-1 mRNA translation as well as of adhesion-stimulating molecules such as Rap1, Ras, and PI 3-kinase. On the other hand, SP slightly induced LFA-1 mRNA translation and activation signals for integrins. The early-phase alteration of LFA-1 mRNA translation after 3 h of culture may be due to the changes of CD8+ T cells rather than changes of CD4+ cells. In adhesion assays, SOM significantly decreased cell adhesion (p < 0.05). Conclusion: These data suggest that SOM treatment of spleen cells, especially in CD8+ T cells, leads to downregulation of LFA-1 mRNA translation, inside-out signaling molecules for integrins (Ras, Rap1 and PI 3-kinase, but not PKC), and consequently to a decrease in the LFA-1-mediated adhesion to ICAM-1.Copyright © 2004 S. Karger AG, Basel

A series of tetralactam macrocycles having different substituents were prepared, and their binding affinities for an adipamide guest were investigated in CDCl3 by ¹H NMR titrations. The association constants strongly depend on the substituents, varying up to ΔΔG = 3.4 kcal/mol; electron-donating substituents (OMe, NMe2) decrease the binding affinity, while electron-withdrawing groups (Cl, NO2) increase it. These large substituent effects have been rationalized by secondary repulsions and partial perturbations of intramolecular hydrogen bonds.

Summary A subinterface crack paralleling an interface between two dissimilar piezoelectric solids is considered. When the distance between the interface and the crack is small compared to all other in-plane lengths, the problem can be analyzed as an asymptotic problem for a semi-infinite crack lying at some distance away from the interface. An integral equation for the asymptotic subinterface crack is derived, and a solution of the integral equation for small-generalized Dundurs parameters is obtained. Relations between the intensity factors for the subinterface crack and interface intensity factors of the corresponding interface crack are obtained for a conducting crack as well as for an insulating one.

Using nitrogen radio-frequency (RF) plasma operated in low-pressure metal-organic chemical vapor deposition (LP-MOCVD), nitrogen-doped ZnSe epilayers were grown and their optical properties were investigated. In the low-temperature photoluminescence (PL) of nitrogen-doped ZnSe epilayers, two emissions were observed, attributed to a nitrogen acceptor-bound exciton (I1) at 2.792 eV and a donor–acceptor pair (DAP) at 2.70 eV. The characteristics of nitrogen acceptor-bound excitons and DAP emissions under excitation power dependent PL spectra were discussed. From theses results, we found that nitrogen was successfully incorporated into selenium sites and then acted as an acceptor. In addition, we obtained the net acceptor concentration 1.15 × 10¹⁸ cm^—3 by capacitance–voltage profiling.

Abstract. Secretory production of human granulocyte colony-stimulating factor fusion protein (hG-CSF) by fed-batch culture of Escherichia coli was investigated in both 2.5-L and 30-L fermentors. To develop a fed-batch culture condition that allows efficient production of hG-CSF, different feeding strategies including pH-stat, exponential and constant feeding were examined. Among these, the constant feeding strategy (0.228 g glucose×min^-1) and the exponential feeding that supports a low specific growth rate (µ=0.116 h^-1) resulted in the best hG-CSF production. Under these conditions, 4.4 g×L^-1 of hG-CSF was produced. The effect of induction time on the protein production was also investigated. For the fed-batch cultures carried out with the pH-stat and exponential feeding strategies, induction at higher cell density (late-exponential phase) resulted in more hG-CSF production compared with induction at lower cell density (early to mid-exponential phase). The constant feeding strategy that supported best hG-CSF production was applied to the scale-up production of hG-CSF in 30 L of fermentor. The maximum dry cell weight and hG-CSF concentration of 51.7 and 4.2 g×L^-1, respectively, was obtained.

We have fabricated multiwalled carbon nanotubes (CNTs) with flowing acetylene, using a well-ordered porous anodic aluminum oxide (AAO) nanotemplate with or without deposition of Co in the pores as a catalyst. Without deposition of Co, the tubes were made in the pores having the shape of the pores by catalysis with the alumina of the AAO templates. With deposition of Co, both alumina and Co could work as a catalyst. By widening the pores after Co deposition, tubes grow out from the pores, by forming a tube-in-tube, which could be used for electrochemical energy storage. Since the alumina of the AAO templates works as a catalyst, one can fabricate special shapes of CNTs by designing the pores of AAO templates. We have succeeded for the first time to fabricate linearly joined CNTs by using AAO templates prepared by using pore widening and multianodization techniques. The electronic properties of the linearly joined CNTs will be affected critically by the junctions that contain five- and seven-membered carbon ring defects and could be controlled by changing the ratio of the two diameters of them. A schematic to fabricate FET (field-effect transistor) using the linearly joined CNTs fabricated on AAO templates has been suggested.

Poly(arylene ether phosphine oxide) (PEPO) with controlled molecular weights and amine end-groups was synthesized, and used as an adhesive, a coating material for adherend or a modifier for diglycidyl ether of bisphenol A (DGEBA)-based epoxy resins. Closely related poly(arylene ether sulfone) and commercial polyethersulfone, Udel® P-1700, were also utilized for comparison purposes. Adhesive behavior was measured via single lap shear samples as a function of coated polymer type, test temperature (R.T. and 100°C), and aging condition in boiling distilled water or 5% salt water. Flame resistance of PEPO and PEPO-modified epoxy resin was evaluated by TGA and a flame test. PEPO exhibited better adhesive properties than PES or Udel® P-1700. PEPO coating on an Al adherend markedly improved adhesive property of PES and Udel® even at 100°C, and after aging study failure mode changed from adhesive to cohesive with the PEPO. Aminophenyl terminated PEPO-modified epoxy resins also exhibited highly improved adhesive behavior and flame resistance, compared to control samples. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1198–1205, 2001

Elastase activity of Vibrio vulnificus was highly dependent on growth phase, reached a maximum during the stationary phase, and was regulated at the level of transcription. The stationary phase production of elastase in crp or rpoS mutants, which were constructed by allelic exchanges, decreased about 3- and 10-fold, respectively. However, the promoter activity of vvpE encoding elastase was unaffected by those mutations in the log phase when analyzed using a vvpE-lux fusion. A primer extension analysis revealed that the transcription of vvpE begins at two different sites, consisting of putative promoter L (PL) and promoter S (PS). The PL activity was constitutive through the log and stationary phases, lower than the PS activity, and unaffected by the crp or rpoS mutations. The transcription of PS, induced only in the stationary phase, was dependent on RpoS. The mutation in crp reduced the activity of PS; however, the additional inactivation of crp did not influence the PS activity in the rpoS mutant, indicating that CRP exerted its effects through PS requiring RpoS. These results demonstrate that vvpE expression is differentially directed by PL and PS depending on the growth phase and elevated by RpoS and CRP in the stationary phase.

Abstract: The vertical distribution of a bloom-forming Microcystis population was studied based on the relevant limnological parameters obtained from the lower Nakdong River (Mulgum) during the summer of 1994. Over three months (late June to late September), a high abundance of Microcystis population (mean � SD, 2.9 � 8.4 � 105 cells ml−1, n = 40) and algal biomass (mean � SD, chlorophyll a, 131 � 346 μg l−1, n = 31) was persistent throughout the entire water column (0–5 m, n = 11). The vertical distribution of carbon content was uneven, with a high concentration near the surface zone (mean � SD, total, 7.9 � 7.8; Microcystis, 5.2 � 8.3 μg C ml−1, n = 15). Incorporating limnological and meteorological factors, a diel study of the vertical distribution of Microcystis showed that the chlorophyll a concentration was highest near the surface zone on a calm night (wind velocity, <2 m s−1, 2300–700) but was evenly distributed on a windy day (>4 m s−1, 1100–1900). Among many possible factors, wind velocity may have played an important role in controlling the vertical distribution of Microcystis in the lower Nakdong River.

Vibrio vulnificus is an opportunistic gram-negative pathogen that commonly contaminates oysters. Predisposed individuals who consume raw oysters can die within days from sepsis, and even otherwise healthy people are susceptible to serious wound infection after contact with contaminated seafood or seawater. Numerous secreted and cell-associated virulence factors have been proposed to account for the fulminating and destructive nature of V. vulnificus infections. Among the putative virulence factors is an elastolytic metalloprotease. We cloned and sequenced the vvpE gene encoding an elastase of V. vulnificus ATCC 29307. The functions of the elastase were assessed by constructing vvpE insertional knockout mutants and evaluating phenotypic changes in vitro and in mice. Although other types of protease activity were still observed in vvpE mutants, elastase activity was completely absent in the mutants and was restored by reintroducing the recombinant vvpE gene. In contrast to previous characterization of elastase as a potential virulence factor, which was demonstrated by injecting the purified protein into animals, inactivation of the V. vulnificus vvpE gene did not affect the ability of the bacteria to infect mice and cause damage, either locally in subcutaneous tissues or systemically in the liver, in both iron-treated and normal mice. Furthermore, a vvpE mutant was not affected with regard to cytolytic activity toward INT407 epithelial cells or detachment of INT407 cells from culture dishes in vitro. Therefore, it appears that elastase is less important in the pathogenesis of V. vulnificus than would have been predicted by examining the effects of administering purified proteins to animals. However, V. vulnificus utilizes a variety of virulence factors; hence, the effects of inactivation of elastase alone could be masked by other compensatory virulence factors.

The by-product of lipid peroxidation, 4-hydroxynonenal (HNE), was shown to cause apoptosis in PC12 cells. In this study, we investigated the molecular mechanism of HNE-induced apoptosis in these cells. Specifically, we determined the effect of HNE on the activities of mitogen-activated protein (MAP) kinases involved in early signal transduction. Within 15 to 30 min after HNE treatment, c-Jun N-terminal protein kinase (JNK) was maximally activated, before it returned to control level at 1 h post-treatment. In contrast, activities of extracellular signal-regulated kinase and p38 MAP kinase remained unchanged from their baseline levels. Stress-activated protein kinase kinase (SEK1), an upstream kinase of JNK, was also activated within 5 min after HNE treatment and remained activated for up to 60 min. Marked activation of the JNK pathway through SEK1 and apoptosis signal-regulating kinase 1 (ASK1), an upstream kinase of SEK1, was demonstrated by the transient transfection of cDNA for wild-type SEK1 or ASK1 together with JNK into COS-7 cells. Furthermore, significant reductions in JNK activation and HNE-induced cell death were observed when either of the dominant negative mutant of SEK1 or ASK1 was cotransfected with JNK. Pretreatment of PC12 cells with a survival-promoting agent, 8-(4-chlorophenylthio)-cAMP, prevented both the HNE-induced JNK activation and apoptosis. Nonaldehyde, a nontoxic aldehyde, neither caused apoptosis nor JNK activation. Pretreatment of PC12 cells with SB203580, a specific inhibitor of p38 MAP kinase, had no effect on HNE-induced apoptosis. All these data suggest that the selective JNK activation by HNE is critical for the apoptosis of PC12 cells and that the HNE-mediated apoptosis is likely to be mediated through the activation of the ASK1-SEK1-JNK pathway without activation of extracellular signal-regulated kinase or p38 MAP kinase.