Protein nanopatterns and biosensors using gold binding polypeptide as a fusion partner

An efficient strategy for immobilizing proteins on a gold surface was developed by employing the gold binding polypeptide (GBP) as a fusion partner. Using the enhanced green fluorescent protein (EGFP), severe acute respiratory syndrome coronavirus (SARS-CoV) envelope protein (SCVme), and core streptavidin (cSA) of Streptomyces avidinii as model proteins, specific immobilization of the GBP-fusion proteins onto the gold nanoparticles and generation of protein nanopatterns on the bare gold surface were demonstrated. The GBP-fused SCVme bound to gold nanoparticles successfully interacted with its antibody and showed changes in absorbance and color, allowing efficient diagnosis of SARS-CoV. The fusion proteins could be successfully immobilized on the gold surface by nanopatterning and microcontact printing as examined by atomic force microscopy and surface plasmon resonance analysis. The poly(dimethylsiloxane) microfluidic channels were created on the gold surface and were used for antigen-antibody and DNA-DNA interaction studies. Specific immobilization of GBP-EGFP fusion protein and its interaction with the antibody in the microchannels could be demonstrated. By immobilizing the DNA probe through the use of GBP-fused cSA, specific hybridization of the target DNA prepared from Salmonella could also be achieved. The GBP-fusion method allows immobilization of proteins onto the gold surface without surface modification and in bioactive forms suitable for studying protein-protein, DNA-DNA, and other biomolecular interaction studies. Furthermore, these studies can be carried out in a microfluidic system, which allows high-throughput analysis of biomolecular interactions.     

Characteristics of pixel arrangements in various rhombuses for full-parallax three-dimensional image generation

In full-parallax three-dimensional (3-D) imaging systems, the pixel cells often have the shape of a rhombus. Proper arrangement of pixels in these rhombic-shaped cells is important to maximize the quality of displayable 3-D images with a given display panel. The possible number of pixel arrangements in a rhombic cell with a definite dimension is found by considering the number of possible crossings between parallel line families forming the pixel cells, when the slopes of the lines are approximated by the ratio between the number of pixels in the vertical and horizontal directions. To make the rhombic cell have a uniquely defined pixel arrangement, its horizontal and vertical dimensions should be equal to the even multiple of the pixel dimension in their corresponding direction.     

Pixel patterns for voxels in a contact-type three-dimensional imaging system for full-parallax image display

Incomplete voxels, which can be seen only at a part of the viewing zone's cross section in the optical configuration of a full parallax multiview imaging system based on a two-dimensional point light source array, are identified. Their corresponding pixel patterns are found to maximize the space where the voxels can exist in the configuration and to increase the voxel resolution of the displayable three-dimensional images. Furthermore, the pixel patterns for the rhomb-shaped pixel cells are also defined, and some problems related to voxel-based image synthesis are discussed.     

Reclamation of Abandoned Coal Mine Waste in Korea using Lime Cake By-Products

Abstract.  There are hundreds of abandoned coal mines in Korea's steep mountain valleys. Enormous amounts of coal waste from these mines were dumped on the slopes, contaminating streams with sediment and acid mine drainage. A limestone slurry by-product (lime cake), which is produced during the manufacture of soda ash, was investigated for its potential use in reclaiming the coal waste. The lime cake is fine grained, has low hydraulic conductivities (10^-8 to 10^-9 cm sec^-1), high pH, high electrical conductivity, and trace amounts of heavy metals. A field experiment was conducted; each plot was 20 x 5 m in size on a 56% slope. Treatments included a control (waste only), lime (CaCO₃), and lime cake. The lime requirement (LR) of the coal waste to pH 7.0 was determined; treatments consisted of adding 25, 50, and 100% of the LR. The lime cake and lime were applied either as a layer between the coal waste and topsoil or mixed into the topsoil and waste. Each plot was hydroseeded with grasses, and planted with trees. In each plot, soils, surface runoff, and subsurface water were collected and analyzed, and plant cover was measured. Lime cake treatments increased the pH of the coal waste from 3.5 to 6, and neutralized the pH of the runoff and leachate of the coal waste from 4.3 to 6.7. Moreover, the surface cover of seeded species was significantly increased; sufficient acidity in the coal waste was neutralized in the 25% LR plots to allow seed germination.     

Production of hydrogen by autothermal reforming of propane over Ni/delta-Al2O3

The performance of Ni/delta-Al2O3 catalyst in propane autothermal reforming (ATR) for hydrogen production was investigated in the present study. The catalysts were characterized using XRD, TEM, and SEM. The activity of the Ni/delta-Al2O3 catalyst manufactured by the water-alcohol method was better than those of the catalysts manufactured by the impregnation and chemical reduction methods. The Ni/delta-Al2O3 catalysts were modified by the addition of promoters such as Mg, La, Ce, and Co, in order to improve their stability and yield. Hydrogen production was the largest for the Ni-Co-CeO2/Al2O3, catalyst.     

Size and shape-tuned overgrowth on Au nanorods regulated by polyallylamine

Au nanorods prepared by a photochemical method were used as seeds for the overgrowth of thin shell of gold by using a mild reducing agent, ascorbic acid at ambient conditions. The overgrowth rate along different crystal facets of the starting gold nanorods was regulated by the addition of polyallylamine. The shape of the resulting gold nanorods was different from the naturally overgrown Au nanorods without any additives.     

A composite photocatalyst of cdS nanoparticles deposited on TiO2 nanosheets

A nanocomposite photocatalyst consisting of deposited CdS nanoparticles on TiO2 nanosheets was fabricated by a simple one-pot method. The contact between two phases was maximized by making a composite structure of TiO2 nanosheet decorated with CdS nanoparticles. The composite photocatalyst showed higher photoactivity for hydrogen production from aqueous Na2S/Na2SO3 solution and decomposition of methylene blue under visible light irradiation (lamda > or =420 nm) compared with single component CdS nanoparticles or a physical mixture of CdS nanoparticles and TiO2 nanorods. The intentional formation of nanoscale heterojunctions between two phases appears beneficial for inducing an efficient electron-hole separation.     

Stabilization of bzip peptides through incorporation of fluorinated aliphatic residues

Two fluorinated amino acids, 5,5,5-trifluoroisoleucine (5TFI) and (2S,3R)-4,4,4-trifluorovaline (4TFV), which have been shown to serve as isoleucine surrogates in protein synthesis in Escherichia coli, have been incorporated in vivo into basic leucine zipper (bzip) peptides derived from GCN4. The extents of residue-specific incorporation of 5TFI and 4TFV were 90 and 88 %, respectively, of the encoded isoleucine residues, as evidenced by MALDI mass spectrometry and amino acid analysis. Both circular dichroism and equilibrium sedimentation studies of the fluorinated bzip peptides indicated preservation of secondary and higher-order protein structure. Thermal-denaturation experiments showed an increase of 27 degrees C in melting temperature when isoleucine was replaced by 5TFI. However, the T(m) of the peptide containing 4TFV was increased by only 4 degrees C over that of the peptide containing valine. Similar trends were observed in chemical denaturation studies in which DeltaDeltaG(unfold) in water was determined to be 2.1 or 0.3 kcal mol(-1) upon incorporation of 5TFI or 4TFV, respectively. When the fluorinated peptides were tested for DNA binding, both their affinity and specificity were similar to those of the respective hydrogenated peptides. These results suggest that fluorinated amino acids, even when introduced into the same positions, can have markedly different effects on the physical properties of proteins, while having little impact on secondary and higher-order structure.     

Simulation of Ca2+-activated Cl- current of cardiomyocytes in rabbit pulmonary vein: implications of subsarcolemmal Ca2+ dynamics

In recent studies, we recorded transiently activated outward currents by the application of three-step voltage pulses to induce a reverse mode of Na+-Ca2+ exchange (NCX). We found that these currents were mediated by a Ca2+-activated Cl- current. Based on the recent reports describing the atrial Ca2+ transients, the Ca2+ transient at the subsarcolemmal space was initiated and then diffused into the cytosolic space. Because the myocardium in the pulmonary vein is an extension of the atrium, the Ca2+-activated Cl- current may reflect the subsarcolemmal Ca2+ dynamics. We tried to predict the subsarcolemmal Ca2+ dynamics by simulating these current traces. According to recent reports on the geometry of atrial myocytes, we assumed that there were three compartments of sarcoplasmic reticulum (SR): a network SR, a junctional SR and a central SR. Based on these structures, we also divided the cytosolic space into three compartments: the junctional, subsarcolemmal and cytosolic spaces. Geometry information and cellular capacitance suggested that there were essentially no T-tubules in these cells. The basic physical data, such as the compartmental volumes, the diffusion coefficients and the stability coefficients of the Ca2+ buffers, were obtained from the literature. In the simulation, we incorporated the NCX, the L-type Ca2+ channel, the rapid activating outward rectifier K+ channel, the Na+-K+ pump, the SR Ca2+-pump, the ryanodine receptor, the Ca2+-activated Cl- channel and the dynamics of Na+, K+, Ca2+ and Cl-. In these conditions, we could successfully reconstruct the Ca2+-activated Cl- currents. The simulation allowed estimation of the Ca2+ dynamics of each compartment and the distribution of the Ca2+-activated Cl- channel and the NCX in the sarcolemma on the junctional or subsarcolemmal space.