Synthesis of a lithium-encapsulated fullerenol and the effect of the internal lithium cation on its aggregation behavior

A lithium-encapsulated fullerenol Li@C₆₀(OH)₁₈, as an example of a polar solvent-soluble endohedral fullerene derivative, has been synthesized and fully characterized by infrared spectroscopy, nuclear magnetic resonance spectroscopy, UV spectroscopy, electron spin resonance (ESR) spectroscopy, matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS), elemental analysis, thermogravimetric analysis, and inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and the particle size was determined using the induced grating (IG) method, and scanning probe microscopy. The encapsulated Li⁺ was clearly detected by ⁷Li NMR at very high field in the range −15 to −19 ppm, an intermediate lithium-encapsulated fullerenol was detected by MALDI-TOF-MS, and the molar ratio of lithium-encapsulated fullerenol to empty fullerenol was quantitatively determined to be 12:88 by ICP-AES. The solid-state ESR and particle size measurements using the IG method showed the characteristic anionic behavior with no external counter cations, in what can be called a “cation-encapsulated anion nanoparticle”, revealing the drastic differences between its properties and those of empty C₆₀(OH)₁₆.      

Protein patterning on functionalized surface prepared by selective plasma polymerization

Techniques for patterned modification of substrate surfaces are important for the formation of microarrays on protein chips. One strategy is based on partial plasma polymerization to create protein adhesive/non-adhesive regions of several tens of micrometers in size. Protein immobilization on a plasma functionalized surface occurs by physical adsorption of a protein solution. Distinct 80 × 80 μm² square spots of fluorescently labeled protein, immunoglobulin G, surrounded by a non-fluorescent 80 μm wide grid were observed. The monomer tetraethylene glycol diethyl ether was the best candidate for plasma polymerization to produce a protein-repellent surface. However, the choice of monomer for the protein adhesive surface was strongly dependent on the type of protein. Binding assays were performed by protein immobilization on the patterned substrate and subsequent reaction with fluorescently labeled counterpart proteins (secondary antibodies). Fluorescent patterning similar to the original pattern was observed. In contrast, patterning was not observed when a fluorescently labeled non-counterpart protein was reacted with the surface. This indicated that the proteins were selectively adsorbed onto the target patterned surface and retained their biofunctional activity in addition to having a suitable orientation of the molecule. Moreover, the protein non-adhesive layer plays a role for suppression of the background signal and enhancement of the signal to noise (S/N) ratio. The proposed technique provides a simple and robust method for protein patterning.     

Water Network in Room-Temperature Ionic Liquid: <Emphasis Type="Italic">N,N</Emphasis>-Diethyl-<Emphasis Type="Italic">N</Emphasis>-Methyl-<Emphasis Type="Italic">N</Emphasis>-2-Methoxyethyl Ammonium Tetrafluoroborate

Crystal structures of room-temperature ionic liquid (RTIL)-H₂O mixtures are determined by the X-ray diffraction method. The RTIL is N,N-diethyl-N-methyl-N-2-methoxyethyl ammonium tetrafluoroborate, [DEME][BF₄]. At 0.9 mol pct H₂O, two kinds of superstructures occur simultaneously without a strain. Also, the volume of the unit cell is very small only at 0.9 mol pct additives. This relates to the composite domain structure, including a twin-related one, as an elastic anomaly. At other water concentrations, such an extraordinary behavior is not observable. By assuming a sublattice having an equivalent lattice constant, a water network at 1 mol pct H₂O is simulated using a Monte Carlo (MC) method. The network develops over the medium range in the simulation box.     

Distribution parameter and drift velocity for two-phase flow in a large diameter pipe

In view of practical importance of the drift flux model for two-phase flow analysis in general, and in the analysis of nuclear reactor transients and accidents in particular, the distribution parameter, and the drift velocity have been studied for two-phase flow in a vertical large diameter pipe. In this, study, local measurements were performed on flow parameters, such as void fraction, gas velocity and, liquid velocity in a vertical upward air–water two-phase flow in a pipe of 200 mm inner diameter and, 25 m in height by using the local sensor techniques such as hot-film probes, optical multi-sensor, probes and differential pressure gauges. Two-phase flow regimes in a vertical large diameter pipe, were classified into bubbly, churn and slug flows according to the visual observation. The values of the, distribution parameter and the mean drift velocity were determined directly by their definition using experiment data of the local flow parameters in a two-phase flow in a large diameter pipe. Various existing drift flux correlations were compared with the present experimental results and experimental data obtained by other researchers. A detailed discussion on the problems of these correlations was presented in this paper.     

Electrochemical behavior of Al in a non-aqueous alkyl carbonate solution containing LiBOB salt

Aluminum was studied as a current collector for rechargeable lithium batteries to understand electrochemical and passivation behavior. Electrochemical polarization tests, in situ scratch polarization tests and time-of-flight secondary ion mass spectroscopy (ToF-SIMS) analysis in lithium bis-oxalato borate (LiBOB)-containing alkyl carbonate solution were conducted. The Al foil did not follow the alloy and de-alloy process with the LiBOB salt in electrolyte at 0 V vs. Li/Li⁺ in the cathodic sweep. During the anodic scan to the noble direction, the absence of an oxidation peak up to 3 V vs. Li/Li⁺ indicated that the air-formed oxide layer of Al was not reduced to metal. Oxide-free Al surfaces made by the in situ scratch test during the electrochemical polarization resulted in abrupt alloy formation with Li at 0 V vs. Li/Li⁺, but the newly formed surface formed passive films at higher potential with oxygen, namely, Al-O compound, as confirmed by ToF-SIMS.     

Hydrogen isotope permeation from cooling water through various metal piping

In order to investigate the behavior of hydrogen isotope on the water–metal boundary, deuterium permeation experiments from heavy water vessel through various metal piping, such as pure iron (Fe), nickel (Ni), stainless steel (SS304), and pure iron with 10 μm gold plating, were performed at 573 K and at 15 MPa. During the experiment, surfaces of metal piping except gold plating one were oxidized at the heavy water boundary and then deuterium would generate by the oxidation reactions. This deuterium could be detected by mass spectrometer, which monitored the inside gases of the piping under continuous evacuation. The result showed clearly that the deuterium permeated through Fe, Ni, and SS304 piping was detected as mainly deuterium gas (D₂) under continuous evacuation, though that through gold plating one could not be detected effectively. The D₂ permeation rate through Fe, Ni, and SS304 piping reached equilibrium conditions with oxide generation at D₂O–metal boundary, although concluding the transfer mechanism will require further testing and modeling activities.     

Development of butt welding of polymeric materials based on softening and stirring effects by hot tool

In this study, new butt welding technique was proposed to join polymeric materials in which the polymeric material is softened by a heated tool due to the Joule effect heating of the electric current flow through the tool, and the coalescence of material is done by the stirring action due to the tool rotation. A 3 mm-thick Polycarbonate (PC) sheets were joined in various joining conditions, from which joining mechanism, mechanical properties of joints and process parameters affecting joint performance were investigated. In the experiments, in situ observation with a CCD camera and material temperature measurement during the process, as well as the observation of surface appearance and cross section of the joint and tensile test were performed for these purposes. It was shown from the in situ observation and material temperature measurement that the molten and softened region is formed around the weld tool. It was also shown that sufficient heat input was required to form sound joints with acceptable performance, which depended upon the joining speed and amount of electric current flow through the tool. The observation of joint appearance and cross section revealed that the joint with comparable thickness to base material was obtained under the condition of revolution pitch below 0.08 mm, defined by the ratio of joining speed to tool rotation. It is noticed that joints obtained from the proper conditions have the same mechanical properties as the base material, and that the process parameters of this method were tool rotation speed, welding speed and amount of electric current. These results suggest proposed method is useful for joining the polymeric materials.     

Numerical study on dynamic behavior of slope models including weak layers from deformation to failure using material point method

This paper describes numerical studies on the dynamic behavior of experimental slope models, including various inclined weak layers. These studies were conducted by simulation of shaking table tests using the material point method (MPM), which allows seamless treatment of various considerations, from elastic behavior to discontinuous collapse behavior of slopes, on the basis of an elasto-plastic constitutive law. The simulation results showed that the failure modes, progressive deformation and downward sliding of the numerical slope models, which were similar to that observed in the shaking table tests, can be obtained using the numerical method. In addition, sensitivity analyses of the numerical models used in this study were performed to determine the effects of mesh size, number of particles per cell (PPC) and damping constants on the simulation results. The results of these analyses indicated the use of fine meshes and high damping constants seems to produce sensible results and reduce numerical noises, respectively.     

Intramammary challenge of lipopolysaccharide stimulates secretion of lingual antimicrobial peptide into milk of dairy cows

Lingual antimicrobial peptide (LAP) belongs to the β-defensin family in cattle and is found in bovine milk. However, it is unclear whether LAP is involved in the early immune response to mammary infection. The aim of the study was to investigate the changes of LAP concentration in milk after intramammary challenge with lipopolysaccharide (LPS), the gram-negative bacteria cell membrane component, in dairy cows. Milk was collected before and after LPS or phosphate-buffered saline (control) challenge every hour for 12 h on d 0 and twice daily from d 1 to 7. Somatic cell count (SCC), LAP concentration, and lactoperoxidase (LPO) activity in the milk were measured. Somatic cell count started to increase at 2 h postchallenge and remained high until d 5 (694 ± 187 × 10³ to >1,000 ± 0 × 10³ cells/mL at d 0; >1,000 ± 0 × 10³ cells/mL at d 1 to 3; 684 ± 194 × 10³ to 829 ± 108 × 10³ cells/mL at d 4; 527 ± 197 × 10³ to 656 ± 145 × 10³ cells/mL at d 5). Somatic cell count increased in the control cows, although the levels were lower compared with those in the LPS challenge group. The LAP concentration in milk increased significantly at 2 h post-LPS-challenge and was maintained at high levels until d 2 (8.6 ± 0.6 to 17.5 ± 2.3 nM). In the control cow infused with phosphate-buffered saline, there was no increase of LAP concentration in milk (5.1 ± 0.6 to 7.2 ± 0.8 nM). Increase of LPO activity in the milk was observed at 6 h after LPS challenge and continued until d 3 (4.7 ± 0.3 to 9.4 ± 1.1 U). No increase of LPO activity was observed in the milk of control cows. The increase and subsequent decrease in LAP concentration after LPS challenge occurred earlier than those of LPO activity. In multiparous cows with LPS infusion, there was a significantly negative relationship between the days leading to the basal levels in LAP concentration and LPO activity (r = −0.75). These results suggest that LPS induces secretion of LAP into milk within hours and that LPO may have a synergistic antimicrobial function with LAP in mammary glands of dairy cows.