Engineering of Lipid Nanoparticles by the Multifunctionalization of the Surface with Amino Acid Derivatives for the Neutralization of a Target Toxic Peptide

Protein affinity reagents (e.g., antibodies) are often used for basic research, diagnostics, separations, and disease therapy. Although a lot of “synthetic” protein affinity reagents have been developed as a cost-effective alternative to antibodies, their low biocompatibility is a considerable problem for clinical application. Lipid nanoparticles (LNP) represent a highly biocompatible drug delivery agent. However, little has been reported that LNP itself works as a protein affinity reagent in living animals. Here, LNP is engineered for binding to and neutralizing a target toxic peptide in living animals by multifunctionalization with amino acid derivatives. Multifunctionalized LNP (MF-LNP) is prepared using amino acid derivative-conjugated lipids. Optimized MF-LNP exhibits nanomolar affinity to the target toxic peptide and inhibits toxic peptide-dependent hemolysis and cytotoxicity. In addition, MF-LNP captures and neutralizes the toxic peptide after intravenous injection in the bloodstream; in addition, MF-LNP does not release the toxic peptide in the accumulated organ. These results reveal the potential of using LNP as a highly biocompatible protein affinity reagent such as an antidote.     

The effect of Na addition on the first hydrogen absorption kinetics of cast hypoeutectic Mg–La alloys

With superior properties of Mg such as high hydrogen storage capacity (7.6 wt% H/MgH₂), low price, and low density, Mg has been widely studied as a promising candidate for solid-state hydrogen storage systems. However, a harsh activation procedure, slow hydrogenation/dehydrogenation process, and a high temperature for dehydrogenation prevent the use of Mg-based metal hydrides for practical applications. For these reasons, Mg-based alloys for hydrogen storage systems are generally alloyed with other elements to improve hydrogen sorption properties. In this article, we have added Na to cast Mg–La alloys and achieved a significant improvement in hydrogen absorption kinetics during the first activation cycle. The role of Na in Mg–La has been discussed based on the findings from microstructural observations, crystallography, and first principles calculations based on density functional theory. From our results in this study, we have found that the Na doped surface of Mg–La alloy systems have a lower adsorption energy for H₂ compared to Na-free surfaces which facilitates adsorption and dissociation of hydrogen molecules leading to improvement of absorption kinetic. The effect of Na on the microstructure of these alloys, such as eutectic refinement and a density of twins is not highly correlated with absorption kinetics.     

Predicting Tensile Properties of Friction-Stir-Welded 6063 Aluminum with Experimentally Measured Welding Heat Input

This work aims to develop a reliable method to predict mechanical properties of friction-stir-welded 6 xxx-series alloys with experimentally measured welding heat input. A calorimetrical method was utilized to experimentally measure the welding heat input in the friction stir welded of aluminum alloy 6063-T5. Good correlations between the input variables, i.e., welding parameters and physical properties of the materials, and the welding heat inputs obtained with experimental measurements were discovered. The welding heat input can be predicted using the empirical equation derived based on these correlations. Moreover, the results suggested that the thermal conductivities of the welded alloys affected the welding heat input significantly. Mechanical properties, including hardness and tensile properties, of friction-stir-welded aluminum alloy 6063 were in good correlation to the heat input obtained with experimental measurement. These correlations were explained by the evolution of the strengthening precipitates during welding. This work proposed a reliable new route to predict these mechanical responses through the estimation of heat input.     

Effect of expander shape on cooling characteristics by using a model pulse tube refrigerator

Pulse tube refrigerators do not have moving parts in the cold section, and they have low vibration, high reliability, and long life. The expander in refrigerators typically has an inverted U or coaxial shape because this attains a wider absorber area, lower height, and compactness. However, the performance of a Stirling-type pulse tube refrigerator is inferior to that of a Stirling refrigerator. Cooling characteristics of the pulse tube refrigerator greatly depend on the shape of the expander. In this study, an inertance-type refrigerator, which uses ambient air for the working gas, was developed to examine the effect of expander shape. This refrigerator model with changeable expander operated with a Stirling cycle, and it was composed of a reciprocating compressor, after-cooler, regenerator, absorber, pulse tube, hot-end, and inertance tube with reservoir. The following expander shapes were tested: in-line, L shape, L-L shape, and coaxial shape. The effect of expander shape on cooling capacity was examined experimentally and numerically using the model pulse tube refrigerator. The results of experiments showed that the L shape expander had the highest performance and the coaxial expander had the lowest performance. In addition, the characteristics of the gas flow in each expander were confirmed by fluid dynamics analysis.     

A molten metal jet impingement on a flat spreading surface

ABSTRACT

In the event of a severe accident, past experiences such as Three Mile Island and Fukushima Daichi have shown that the reactor core of a light-water nuclear reactor, if not properly safeguarded, could go through a meltdown. This will be followed by the formation of a corium, a mix of molten fuel elements, and liquid metals from the Reactor Pressure Vessel (RPV). In the worst-case scenario, a melt through from the RPV can occur and lead to the spreading of the corium, in the form of a molten element’s jet impinging on a flat concrete structure of the Primary Containment Vessel (PCV). To enhance the decommissioning and the safety procedure, scope of the present article is to deepen the understanding of the phenomena involved in the mentioned scenario, mainly jet-instability and molten material spreading. In the present study, experiments were carried out, by using corium simulant materials such as Copper and Tin, to investigate the link between the instability of the gravity-driven molten metal jet and the impinging followed by its spreading over a flat area.     

Monitoring behaviour of catabolic genes and change of microbial community structures in seawater microcosms during aromatic compound degradation

The behaviour of microbial populations responsible for degradation of the aromatic compounds, phenol, benzoate, and salicylate, and changes of microbial community structures in seawater microcosms were analysed quantitatively and qualitatively using MPN–PCR and PCR–DGGE. The purpose of the study was to investigate the ecology of the entire microbial community during bioremediation. Bacterial populations possessing catechol 1,2-dioxygenase (C12O) DNA were evidently the primary degraders of phenol and benzoate, but others possessing catechol 2,3-dioxygenase (C23O) DNA increased to enhance substrate degradation under high-load conditions when the substrates were present for long periods. However, salicylate degradation was evidently facilitated by specific bacterial populations possessing C23O DNA. PCR–DGGE analyses suggested that bacterial populations already relatively dominant in the original microcosm contributed to phenol degradation. Bacteria composing a minor fraction of the original population apparently increased and contributed to benzoate degradation. Bacterial populations possessing C23O DNA were responsible for salicylate degradation, however, and different degrading bacteria were evidently selected for, depending on the initial salicylate concentration. Microbial community structure tended to be simplified by aromatic compound degradation. Thus, microbial monitoring can elucidate the behaviour of bacterial populations responsible for aromatic compound degradation and be used to assess the effects of bioremediation on intact microbial ecosystems.     

Feasible method,utilizing density changes,for estimating in situ dynamic strength and deformation properties of sand samples

Laboratory tests and design reliability are directly controlled by sample quality. The frozen sampling (FS) method is useful for dynamic strength and deformation tests of undisturbed clean sand. However, it is very expensive and requires considerable equipment. The sample quality of Toyoura sands obtained from 48 mm and 75 mm samplers are scrutinized based on void ratio, dynamic strength and deformation properties through model and cyclic undrained triaxial tests. A conventional method for estimating in-situ dynamic strength and deformation properties of sand samples utilizing density changes is examined and the applicability of the proposed method is discussed for the samples obtained from Niigata sand deposits.The main conclusions obtained from this study are summarized as follows:(1) A conventional method for estimating in-situ void ratio (e₀), D_r, stress ratio (R_L20) in a 20 cyclic time frame and the initial modulus of rigidity (G₀) of sand samples utilizing density changes is proposed.(2) The in-situ R_L20 and G₀ estimated from the proposed method for sand samples from tube samplers were similar to those of frozen sampling and the in-situ modulus of initial rigidity was calculated from the secondary wave velocity for Niigata sand deposits.Therefore, dynamic strength and deformation properties changes, caused by sampling, can be modified appropriately to an in-situ condition by this proposed method.     

Study on the fabrication of a SU-8 cantilever vertically-allocated in a closed fluidic microchannel

Microsystem Technologies - This paper describes the fabrication of a vertically-allocated SU-8 cantilever in a closed fluidic channel. The difficulties to fabricate the vertically-allocated SU-8...