A PEG-based biocompatible block catiomer with high buffering capacity for the construction of polyplex micelles showing efficient gene transfer toward primary cells

Nonviral gene vectors from synthetic catiomers (polyplexes) are a promising alternative to viral vectors. In particular, many recent efforts have been devoted to the construction of biocompatible polyplexes for in vivo nonviral gene therapy. A promising approach in this regard is the use of poly(ethylene glycol) (PEG)-based block catiomers, which form a nanoscaled core-shell polyplex with biocompatible PEG palisades. In this study, a series of PEG-based block catiomers with different amine functionalities were newly prepared by a simple and affordable synthetic procedure based on an aminolysis reaction, and their utility as gene carriers was investigated. This study revealed that the block catiomers carrying the ethylenediamine unit at the side chain are capable of efficient and less toxic transfection even toward primary cells, highlighting critical structural factors of the cationic units in the construction of polyplex-type gene vectors. Moreover, the availability of the polyplex micelle for transfection with primary osteoblasts will facilitate its use for bone regeneration in vivo mediated by nonviral gene transfection.     

Investigation of soil deformation characteristics during pullout of a ribbed reinforcement using X-ray micro CT

Steel-strip reinforced earth walls stabilize through the pullout resistance of the reinforcements. Soil dilation during the pullout of ribbed reinforcements may contribute to the evolution of pullout resistance; however, few studies have clarified this mechanism by investigating how soils behave with increasing pullout displacement. The ribs of the reinforcements enhance the pullout resistance, although the influence of the rib dimensions on the evolution of pullout resistance with increasing pullout displacement has not been sufficiently revealed. In the present study, a triaxial pullout apparatus is developed and pullout tests are conducted using ribbed reinforcements with different rib-inclination angles under isotropic stress. The displacement and strain fields in the soils during the pullout of the reinforcements are investigated by X-ray micro CT and a digital image correlation technique. It is found that larger rib-inclination angles provide higher pullout resistance at an early stage of the pullout because of the higher bearing resistance related to the more significant soil densification above the ribs. With increasing pullout displacement, the reinforcements with different rib-inclination angles come to behave as almost one in the same since a rigid soil wedge related to the passive soil failure is generated above the ribs. This tendency results in similar soil deformation characteristics and pullout resistance levels for every reinforcement beyond the soil failure state, although the rib-inclination angles are different.     

Preparation of macroreticular anion exchange membrane and its behavior relating to organic fouling

Base membranes were prepared by coating a monomer mixture consisting of styrene–divinylbenzene–polybutadiene–t-amyl alcohol onto a polypropyrene cloth and subsequently by polymerizing the monomers. The resultant base membranes were chloromethylated and then quaternized. Thus, macroreticular anion exchange membranes were prepared and their properties were investigated. Furthermore, the organic fouling of the membranes was studied by using Na dodecylbenzenesulfonate as a foulant. The resistibility of the membranes was dependent on the balance between the porosity of the membranes and the foulant quantity.     

Influence of external additives on the preservation of carthamin red colour: an introductory test for utilizing carthamin as a herbal colorant of processed foods

A number of carbohydrates and related compounds was admixed with carthamin in an acidic buffer solution and the effect of the test chemicals on carthamin stability examined at low temperature. Monosaccharides were scarcely effective, although slightly accentuated values were obvious in thed-forms (d-forml-form=1.31.0). Disaccharides were less effective for carthamin red preservation (dimermonomer=1.01.8). However, a high level of colour conservation was observed with sugar alcohols. Both polyethylene glycol and glycerine very effectively protected carthamin from bleaching in solution: the colour preservation rates calculated were 91.3% and 83.8%, respectively, after 24 h incubation at 5° C in the dark. Gelatine was also effective for maintaining carthamin colour (preservation rate: 81.3%). The results are assessed in connection with utilizing carthamin as a herbal colorant of processed foods.

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Einfluß von Zusatzstoffen nach Konservierung des Carthaminrots. Ein Test für die Verwertung von Carthamin als pflanzliche Farbe für verarbeitete Lebensmittel

Zusammenfassung Eine Zahl von Kohlenhydraten und verwandten Verbindungen wurden mit Carthamin in saurer Pufferlösung vermischt und die Wirkung auf dessen Stabilität bei niederer Temperatur getestet. Die Monosaccharide waren kaum effektiv, jedoch died-Form beschleunigte etwas stärker (d-Forml-Form=1.31.0). Die Disaccharide waren weniger wirksam auf die Farberhaltung (DimerMonomer=1.01.8). Jedoch wurde eine gute Farbkonservierung mit Zuckeralkoholen beobachtet, sowohl Polyethyleneglycol und auch Glycerin schützten Carthamin sehr wirksam zu 91,3 bzw. 83,8% nach 24h Einwirkung. Auch Gelatine war sehr farberhaltend (81,3%). Die Resultate wurden in bezug auf ihre Verwendung von Carthamin als Farbe für industriell verarbeitete Lebensmittel beurteilt.

     

A parametric logistic equation with light flux and medium concentration for cultivation planning of microalgae

Microalgae are considered to be promising producers of bioactive chemicals, feeds and fuels from carbon dioxide by photosynthesis. Thus, the prediction of microalgal growth profiles is important for the planning of cost-effective and sustainable cultivation–harvest cycles. This paper proposes a mathematical model capable of predicting the effect of light flux into culture and medium concentration on the growth profiles of microalgae by incorporating these growth-limiting factors into a logistic equation. The specific form of the equation is derived based on the experimentally measured growth profiles of Monoraphidium sp., a microalgal strain isolated by the authors, under 16 conditions consisting of combinations of incident light fluxes into culture and initial medium concentrations. Using a cross-validation method, it is shown that the proposed model has the ability to predict necessary incident light flux into culture and initial medium concentration for harvesting target biomass at a target time. Finally, model-guided cultivation planning is performed and is evaluated by comparing the result with experimental data.     

Probability of cochannel interference in the case of noncoherentphasor addition with unequal powers in Rayleigh fading environments

New, closed form expressions are derived for calculation of the probability of cochannel interference (PCI) in Rayleigh fading environments when interfering phasors with unequal mean powers add noncoherently in the receiver. Expressions enable PCI calculation at every point within a cell and/or cluster, both in base stations and mobile units     

Reaction of Silane with Atomic Oxygen at High Temperatures

The reaction of silane with atomic oxygen (³P) was investigated by the shock-tube–laser-photolysis method over the temperature range of 900–1170 K. Oxygen atoms were produced by the ArF laser photolysis of SO₂ behind reflected shock waves and monitored with atomic resonance absorption spectroscopy. The rate constant for the SiH₄ + O reaction was evaluated by taking the possible contribution of the consecutive reaction into consideration. The Arrhenius temperature coefficient was determined to be E_a= 26.6 kJ mol⁻¹, which is much higher than the experimental activation energies obtained at lower temperatures. Rate constants calculated by a transition state theory with the reaction barrier height of E₀= 10.2 kJ mol⁻¹ agreed well with both the present and the previous experimental results for a wide temperature range.     

Friction and wear of self-mated SiC and Si3N4 sliding in water

The friction and wear of self-mated SiC and Si₃N₄ with different initial roughness sliding in water were investigated with pin-on-disk apparatus at normal load of 5 N and sliding speed of 120 mm/s in ambient condition. It was found that, for self-mated Si₃N₄, the wear mechanism for surface smoothening to obtain low friction was tribochemical wear, but for self-mated SiC, it changed from mechanical wear into tribochemical wear with increasing sliding cycles. After running-in in water, self-mated Si₃N₄ exhibited lower steady-state friction coefficient than self-mated SiC did. For these two ceramics, initial and steady-state friction coefficients were hardly dependent on initial roughness. Initial roughness mainly affected the running-in period. The larger the initial roughness, the longer the running-in period, but the running-in period was much shorter for self-mated Si₃N₄ at each initial roughness than that for self-mated SiC.     

A new enzymatic method for the extraction of precarthamine from dyer's saffron florets

Precarthamine was extractable at a high yield from the floret paste of dyer's saffron, when pretreated with glucosidase in water. The hydrolysate extraction conditions, recovery rate, and identification were studied in order to establish a new enzymatic method for the preparation of precarthamine. The results are evaluated by comparison with the old procedures.

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Eine neue enzymatische Methode zur Extraktion von Precarthamin aus Safranblütenpaste

Zusammenfassung Precarthamin wurde in großer Menge aus Safranblütenpaste extrahiert, die mit Glucosidase in Wasser vorbehandelt wurde. Die Hydrolysebedingungen, die Ausbeute und die Identifizierung wurden studiert, um eine neue enzymatische Methode für die Herstellung von Precarthamin zu entwickeln. Die Resultate wurden mit der alten Arbeitsweise verglichen.