Chain conformation of polyethylene in the solid state as studied by 13C cross-polarization/magic angle spinning nuclear magnetic resonance spectroscopy

High-resolution ¹³C nuclear magnetic resonance (n.m.r.) spectra of melt-quenched polyethylene and polyethylene single crystals are measured by the cross-polarization/magic angle spinning technique. Melt-quenched polyethylene and polyethylene single crystals have four small upfield peaks, a shoulder on the main peak and three small peaks, respectively. Based on the ¹³C n.m.r. resonance lines of cyclic paraffin C₆₄H₁₂₈ reported previously, it is concluded that the main peak and the three upfield peaks arise from the trans zigzag structure region and the folded structure region, respectively. From these peak intensities, it is estimated that the stem length of polyethylene single crystals is approximately 125 Å. Taking into account an error in the estimation of the small peak intensities, the calculated stem length of 125 Å is consistent with the crystal thickness (120–150 Å) observed directly by electron microscopy. It can be concluded, therefore, that polyethylene single crystals mainly contain sharply folded structure. Melt-quenched polyethylene may contain sharply folded structure to some extent in addition to loose loops.     

Long-term variations in dissolved trace elements in the Sagami River and its tributaries (upstream area), Japan

We investigated long-term variations in dissolved chemical species in water sampled from the Sagami River and its tributaries, Japan. The samples were taken monthly from May 1993 to April 2000 at 28 sampling sites in the Sagami River system. In this paper, we concentrate on 17 sites in the upper catchment. Twenty-four major to trace elements (Li, Mg, Al, Ca, V, Mn, Fe, Co, Ni, Cu, Zn, As, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, W, Tl, Pb, U) were determined by using conventional Q-pole ICP-MS with direct nebulizalion. Water flux was measured from 1995. The data for most species were subjected to fast Fourier transformation (FFT) to extract dominant periodicities, their magnitudes, and their phases. Clear seasonal variations were observed for Al, V, As, Rb and Cs at some sampling points, especially in the tributaries. The seasonal variations may be due to either anthropogenic causes, such as irrigation or wastewater discharge, or natural causes, such as water temperature, pH, redox condition, water flux, or activity of microorganisms. We found no correlation with pH. Water temperature may not be a main controlling factor, although the seasonal variability would be correlated with it. Hydrologic factors may have only minor effects. We suggest that most of the seasonal variation might be correlated with the irrigation of rice paddies. It was difficult to identify all the causes of the seasonal variability. To investigate interannual trends, we used centered 12-month moving averages to eliminate seasonal variations. The water quality of the uppermost streams was generally constant, being controlled by springs on Mt. Fuji. However, in 1993 and 1998, V, As, Rb, Cs and U were depleted briefly, possibly by dilution by overflow from Lakes Kawaguchi and Yamanaka. Hydrologic factors may be more important for interannual variability than seasonal variability. Some heavy trace elements (Zn, Ni, Cd and Sb) showed very irregular variations with high concentration peaks. These elements were discharged from either factories or abandoned mine tailings.     

Development of a novel glue consisting of naturally-derived biomolecules: citric acid and human serum albumin

A novel glue consisting of human serum albumin (HSA) and citric acid derivative (CAD) was developed where the glue is named as CAD-A glue. In this adhesive, CAD works as a crosslinking reagent of HSA. For preparing crosslinking reagent CAD, using citric acid as a starting material, three carboxyl groups of a citric acid were modified with N-hydroxysuccinimide in the presence of 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride. From 1H-NMR spectrum, CAD with three active ester groups in a molecule was successfully synthesized with a high yield (more than 80%). The boding time of CAD-A glue to collagen-based casing was saturated within 15 minutes. The bonding strength of this glue to collagen-based casings increased with increasing of HSA concentration. The maximum bonding strength of CAD-A glue was a slightly low level compared to the bonding strength of cyanoacrylate adhesive and was 9 times higher than that of fibrin glue. The CAD-A glue showed excellent biocompatibility and high ability of wound closure similar to that of cyanoacrylate-based adhesive when glues were applied to the mouse skin. These results suggested that this developed adhesive had both tissue compatibility and bonding strength for use in clinical field.     

Effects of Two Distinct Psychoactive Microbes,Lacticaseibacillus rhamnosus JB-1 and Limosilactobacillus reuteri 6475, on Circulating and Hippocampal mRNA in Male Mice

Discovery of the microbiota-gut–brain axis has led to proposed microbe-based therapeutic strategies in mental health, including the use of mood-altering bacterial species, termed psychobiotics. However, we still have limited understanding of the key signaling pathways engaged by specific organisms in modulating brain function, and evidence suggests that bacteria with broadly similar neuroactive and immunomodulatory actions can drive different behavioral outcomes. We sought to identify pathways distinguishing two psychoactive bacterial strains that seemingly engage similar gut–brain signaling pathways but have distinct effects on behaviour. We used RNAseq to identify mRNAs differentially expressed in the blood and hippocampus of mice following Lacticaseibacillus rhamnosus JB-1, and Limosilactobacillus reuteri 6475 treatment and performed Gene Set Enrichment Analysis (GSEA) to identify enrichment in pathway activity. L. rhamnosus, but not L. reuteri treatment altered several pathways in the blood and hippocampus, and the rhamnosus could be clearly distinguished based on mRNA profile. In particular, L. rhamnosus treatment modulated the activity of interferon signaling, JAK/STAT, and TNF-alpha via NF-KB pathways. Our results highlight that psychobiotics can induce complex changes in host gene expression, andin understanding these changes, we may help fine-tune selection of psychobiotics for treating mood disorders.     

Effect of display of YOLO’s object recognition results to HMD for an operator controlling a mobile robot

Artificial Life and Robotics - An operator feels a burden when he/she controls a rescue robot remotely because he/she has to keep watching camera images to find the target object. We think that...