Elimination of ingredients effect to improve the detection of anti HIV-1 p24 antibody in human serum using SPR apparatus.

Highly sensitive detection of proteins in serum becomes difficult in some cases during surface plasmon resonance (SPR) measurements, because some ingredients in the serum hugely enhance non-specific reactions on the sensing chip of SPR. It is well recognized that the antibody against core protein p24 of HIV in serum is one of the most important proteins in the accurate diagnosis of infection with HIV. In this study, we could attain the accurate detection of anti p24 antibody in human serum by eliminating the serious effects of the ingredients in serum on the measurement of SPR by employing these procedures: 1) blocking the gold surface of the sensing chip with human serum and 2) heating the serum sample at 56 degrees C for 30 min. Without these treatments, the signal of SPR was considerably suppressed on the measurements of the anti p24 antibody which contained human serum, making the accurate detection difficult. However, with introducing the above two treatments, the sensing of anti p24 antibody in human serum was improved, while a small non-specific reaction was still observed. By removing the non-specific reaction caused by the ingredients in the serum, we could accurately measure the antibody for p24 in human serum sample over the range from 1 to 20 micrograms/ml.     

Bioaccumulation of arsenic by freshwater algae (Nostoc sp.) and the application to the removal of inorganic arsenic from an aqueous phase

An arsenic-resistant blue-green alga, Nostoc sp., was screened from an arsenic-polluted environment. The effects of the culture conditions on the growth and the arsenic bioaccumulation were investigated. In five culture media tested, Microcystis aeruginosa medium was found to be optimum for the growth. The effects of the concentration of five nutrients (P, Co, Fe, Mo and N) in the MA medium on arsenic bioaccumulation by the Nostoc sp. were also investigated. From the experimental results, the authors proposed a new culture medium which was designed for effective arsenic bioaccumulation by the Nostoc sp. The new medium was named the Modified MA medium (abbreviated as MMA). Removal of arsenic from an aqueous phase by means of arsenic bioaccumulation by the Nostoc sp. was investigated. When arsenic-polluted water was enriched with the nutrients of MMA, the arsenic level was found to be effectively lowered by the Nostoc sp. to 0.05 ppm.     

Modular synthesis of benzo[b]phosphole derivatives via BuLi-mediated cyclization of (o-alkynylphenyl)phosphine

Treatment of an (o-alkynylphenyl)phosphine with a stoichiometric amount of BuLi effects a cyclization reaction to produce a 3-lithiobenzo[b]phosphole, which affords a variety of 3-substituted benzophospholes upon reaction with electrophiles. An example is given for the synthesis of a bis-benzo[b]phosphole, which can be further converted to the corresponding benzo[b]phosphole oxide possessing high electron affinity.     

Simple,Rapid, and Large-Scale Fabrication of Multi-Branched Hydrogels Based on Viscous Fingering for Cell Culture Applications

Hydrogels are widely used in cell culture applications. For fabricating tissues and organs, it is essential to produce hydrogels with specific structures. For instance, multiple-branched hydrogels are desirable for the development of network architectures that resemble the biological vascular network. However, existing techniques are inefficient and time-consuming for this application. To address this issue, a simple, rapid, and large-scale fabrication method based on viscous fingering is proposed. This approach utilizes only two plates. To produce a thin solution, a high-viscosity solution is introduced into the space between the plates, and one of the plates is peeled off. During this procedure, the solution's high viscosity results in the formation of multi-branched structures. Using this strategy, 180 mm × 200 mm multi-branched Pluronic F-127 hydrogels are successfully fabricated within 1 min. These structures are used as sacrificial layers for the fabrication of polydimethylsiloxane channels for culturing human umbilical vein endothelial cells (HUVECs). Similarly, multi-branched Matrigel and calcium (Ca)-alginate hydrogel structures are fabricated, and HUVECs are successfully cultured inside the hydrogels. Also, the hydrogels are collected from the plate, while maintaining their structures. The proposed fabrication technique will contribute to the development of network architectures such as vascular structures in tissue engineering.     

Structural development of benzhydrol-type 1'-acetoxychavicol acetate (ACA) analogs as human leukemia cell-growth inhibitors based on quantitative structure-activity relationship (QSAR) analysis

Benzhydrol-type analogs of 1'-acetoxychavicol acetate (ACA) were developed as inhibitors of human leukemia HL-60 cell growth based on quantitative structure-activity relationship (QSAR) analysis. An analog containing an anthracenyl moiety (8) was a potent inhibitor with the IC(50) value of 0.12 microM.     

Effects of low-temperature chemistry on the wall heat flux in HCCI combustion

Direct numerical simulations of homogeneous charge compression ignition combustion are performed to investigate the behaviour of the wall heat flux, Φ, under engine relevant conditions. In laminar conditions, there are four distinctive stages where Φ evolution is affected by low-temperature chemistry (LTC), resulting in multiple local maxima with a lagged maximum value in Φ evolution. These effects are also observed in turbulence conditions locally. However, they no longer appear in the mean Φ evolution clearly, although some weak non-monotonicity in Φ due to the LTC are observed. The locality of the LTC effects may need to be addressed for near-wall pollutant prediction in future.     

Transmission characteristics of photonic crystal waveguides with stubs and their application to optical filters

We study the transmission characteristics of a photonic crystal waveguide with a single stub of a finite length and propose a double-stub waveguide structure for its application to optical filters. The proposed device operates as a Fabry-Perot interferometer and can be used as a broad bandstop filter and a narrow bandpass filter. These filters are inherently compact and their center frequency is given by the resonant frequency of the stub.     

Enzymatic Cell-Surface Decoration with Proteins using Amphiphilic Lipid-Fused Peptide Substrates

Lipid modification of proteins plays a significant role in the activation of cellular signals such as proliferation. Thus, the demand for lipidated proteins is rising. However, getting a high yield and purity of lipidated proteins has been challenging. We developed a strategy for modifying proteins with a wide variety of synthetic lipids using microbial transglutaminase (MTG), which catalyzes the cross-linking reaction between a specific glutamine (Q) in a protein and lysine (K) in the lipid-fused peptide. The synthesized lipid-G₃S-MRHKGS lipid (lipid: fatty acids, tocopherol, lithocholic acid, cholesterol) was successfully conjugated to a protein fused with LLQG (Q-tagged protein) by an MTG reaction, yielding >90 % conversion of the Q-tagged protein in a lipidated form. The purified lipid–protein conjugates were used for labeling the cell membrane in vitro, resulting in best-anchoring ability of cholesterol modification. Furthermore, in situ cell-surface decoration with the protein was established in a simple manner: subjection of cells to a mixture of cholesterol-fused peptides, Q-tagged proteins and MTG.     

Redox-responsive conformational alteration of aromatic amides bearing N-quinonyl system

Redox-induced conformational alteration of N-aryl-N-phenylamides, in which the N-aryl group consists of a hydroquinone–p-quinone system, was examined. The reduced form bearing a dihydroxyphenyl or dimethoxyphenyl group exists mainly in the E-form, whereas the oxidized form bearing a N-benzoquinone moiety takes the Z-form both in the crystal and in solution. This redox-induced conformational alteration is associated with a marked change in optical properties. This system appears to have suitable properties for use in external redox stimulus-responsive functional switching.