In situ detection of microorganisms by fluorescence in situ hybridization (FISH) is a powerful tool for environmental microbiology, but analyses can be hampered by low rRNA content in target organisms, especially in oligotrophic environments. Here, we present a non-enzymatic, hybridization chain reaction (HCR)-based signal amplified in situ whole-cell detection technique (in situ DNA-HCR). The components of the amplification buffer were optimized to polymerize DNA amplifier probes for in situ DNA-HCR. In situ hybridization of initiator probes followed by signal amplification via HCR produced bright signals with high specificity and probe permeation into cells. The detection rates for Bacteria in a seawater sample and Archaea in anaerobic sludge samples were comparable with or greater than those obtained by catalyzed reporter deposition (CARD)-FISH or standard FISH. Detection of multiple organisms (Bacteria, Archaea and Methanosaetaceae) in an anaerobic sludge sample was achieved by simultaneous in situ DNA-HCR. In summary, in situ DNA-HCR is a simple and easy technique for detecting single microbial cells and enhancing understanding of the ecology and behaviour of environmental microorganisms in situ.

The method of coating electrospun ultrafine poly(L-lactic acid) fibers with DNA, by building up polyelectrolyte layer(s) of poly(ethyleneimine) (PEI) and plasmid DNA using an electrostatic layer-by-layer deposition method, for gene delivery is presented. The pGL3 encoding luciferase was applied as plasmid DNA. The quantity of pGL3 immobilized on individual fibers increased with increasing pGL3 concentration in the immersion solution (0.017-0.870 mg/mL) and increasing bilayer number of PEI/pGL3 (single-triple). With the exception of one specimen prepared under the condition 0.870 mg/mL pGL3 solution and double PEI/pGL3 layers, the transfection efficiency of COS-7 cells, defined by the ratio of fluorescence intensity (resulting from the presence of luciferase) with respect to the quantity of cellular protein on the fibrous mat increased with increasing quantity of pGL3 on the fibers. In addition to the ease of controlling the quality of polyelectrolyte bilayer(s) by simply changing the concentrations of substances and number of immersing cycles, the features of the electrospun fibrous mat such as a very large surface-to-volume ratio and flexibility, could potentially be employed as a strategy for gene therapy combined with tissue engineering technology.

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This paper describes the first persistent-mode medium magnetic field (400 MHz; 9.39 T) nuclear magnetic resonance (NMR) magnet which uses superconducting joints between high-temperature superconductors (HTSs). As the ultimate goal, we aim to develop a high-resolution 1.3 GHz (30.5 T) NMR magnet operated in the persistent-mode. The magnet requires superconducting joints between HTSs and those between an HTS and a low-temperature superconductor (LTS). Towards this goal, we have been developing persistent-mode HTS inner coils to be operated in a 400 MHz (9.39 T) NMR magnet and here we present the first prototype inner coil wound with a single piece (RE = rare earth)Ba2Cu3O7−x (REBCO) conductor. The coil and a REBCO persistent current switch are connected with intermediate grown superconducting joints with high critical currents in external magnetic fields. To evaluate the performance of the joints in an ultimately stable and homogeneous magnetic field, the coil is operated in the persistent-mode, generating 0.1 T, in a 9.3 T background magnetic field of a persistent-mode LTS outer coil. The magnetic field drift over two years of the 400 MHz LTS/REBCO NMR magnet is as small as ∼1 ppm, giving high-resolution NMR spectra. The magnetic field drift rate over the second year was 0.03 × 10−3 ppm h−1, which is more than three orders of magnitude smaller than that required for an NMR magnet, demonstrating that the superconducting joints function satisfactorily in a high-resolution NMR system. The corresponding joint resistance is inferred to be <10−14 Ω.

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Electrospinning involves the generation of a jet of viscous solution, and results in the formation of ultra-fine fibers. Silicate fibers prepared using this technology and via the sol-gel process were evaluated as scaffolds for bone tissue engineering. We found that human osteoblastic MG63 cells successfully adhered on individual silicate fibers, and proliferated on them. In an apatite-formation ability study, spherical particles covered the fibers after soaking in simulated body fluid for 7 days. Energy dispersive X-ray analysis revealed that Ca/P atomic ratio of the particles was similar to that of human bone. In addition, X-ray diffraction analysis revealed that crystalline structure of the particles agreed with that of apatite. These results suggest that electrospun silicate fibers are a potential candidate for scaffolding material in bone tissue engineering.

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The lipase of Pseudomonas cepacia was immobilized onto electrospun polyacrylonitrile (PAN) fibers and used for the conversion of (S)-glycidol with vinyl n-butyrate to glycidyl n-butyrate in isooctane. The rate of reaction with the adsorbed lipase was 23-fold higher than the initial material. After 10 recyclings, the initial reaction rate was 80% of the original rate. This system of enzyme immobilization is therefore suitable for carrying out transesterification reactions in nonaqueous solvents.