Structure characterization of alginate and conformational behaviors of various alkali-metal alginates in solution

Summary The M/G ratio, i. e., number-ratio of D-mannuronate (M) to L-gluronate (G), and diad (MM, GG, MG, etc.) and triad (MMM, MMG, MGM, etc.) frequencies were determined with 100 MHz ¹³C-NMR spectra for two alginate samples, M-rich and G-rich samples. The M/G ratios obtained were in accord with those determined from chemical analysis on hydrolyzed products fairly well. Molecular chain dimensions in solution were investigated by viscosity method for five alkali-metal alginates carrying Li, Na, K, Rb and Cs, and the results were discussed based on ion radius and electronegativity of alkali-metals. Finally, ion-exchange characteristics of these alginates by Ca⁺⁺ ion were interpreted with M/G ratio and electronegativity.     

The dynamism of 2channel

2channel is the most popular online-community site in Japan, where millions of people are discussing or chitchatting about various topics. The communication in 2channel shows dynamic social phenomena such as positive/negative communication, polarization of opinions, slander called flaming, etc. In this paper, we assume the existence of underlying prevailing structures that motivate peoples participation. The structural equation model of 2channel, which is obtained on the basis of observed collective actions about peoples thought, emotions and motivations, shows the uniformity and regularities in complex human communication in 2channel.     

Prediction of protein-protein interaction sites using support vector machines

The identification of protein-protein interaction sites is essential for the mutant design and prediction of protein-protein networks. The interaction sites of residue units were predicted using support vector machines (SVM) and the profiles of sequentially/spatially neighboring residues, plus additional information. When only sequence information was used, prediction performance was highest using the feature vectors, sequentially neighboring profiles and predicted interaction site ratios, which were calculated by SVM regression using amino acid compositions. When structural information was also used, prediction performance was highest using the feature vectors, spatially neighboring residue profiles, accessible surface areas, and the with/without protein interaction sites ratios predicted by SVM regression and amino acid compositions. In the latter case, the precision at recall = 50% was 54-56% for a homo-hetero mixed test set and >20% higher than for random prediction. Approximately 30% of the residues wrongly predicted as interaction sites were the closest sequentially/spatially neighboring on the interaction site residues. The predicted residues covered 86-87% of the actual interfaces (96-97% of interfaces with over 20 residues). This prediction performance appeared to be slightly higher than a previously reported study. Comparing the prediction accuracy of each molecule, it seems to be easier to predict interaction sites for stable complexes.     

Retrieving information on the World Wide Web: effects of domain specific knowledge

In this study, we intend to examine information retrieval behaviors from a psychological point of view using a search engine on the World Wide Web (WWW). We investigated information retrieving behaviors in detail based on both the recorded data of retrievers’ web browsing actions and their thinking processes by the “think aloud” method. We focused on selected keywords for retrieving and compared them between retrievers who had enough knowledge about their task and those who did not. Our goal was to learn about the literacy needed for finding required information efficiently on the WWW.

Structure of decrystallized cotton in fabrics prepared by alkali and acrylonitrile treatments

The crystalline structure of decrystallized cotton, prepared by partial cyanoethylation with the use of sodium hydroxide aqueous solution and acrylonitrile, was examined by x-ray and IR data, in connection with such fabric properties as moisture regain. It was found that the moisture regain of the cotton fabric first increased, passed through a maximum at about 6 mole-% of cyanoethylation, and then slightly decreased with increasing degree of cyanoethylation. The increase of moisture regain in the region of the lower degree of cyanoethylation was well related to the decrease in the crystallinity of cotton. The x-ray diffraction studies revealed that the distension and disorder of the unit cell occurred primarily in the direction perpendicular to the (101) crystal plane as cyanoethylation proceeded.     

Organic solvent tolerance of Escherichia coli is independent of OmpF levels in the membrane

The organic solvent tolerance of Escherichia coli was measured under conditions in which OmpF levels were controlled by various means as follows: alteration of NaCl concentration in the medium, transformation with a stress-responsive gene (marA, robA, or soxS), or disruption of the ompF gene. It was shown that solvent tolerance of E. coli did not depend upon OmpF levels in the membrane.     

Natural convection and radiation heat transfer in a vertical porous layer with a hexagonal honeycomb core (Part 2: heat transfer experiment)

Combined natural convection and radiation heat transfer characteristics in a vertical porous layer with a hexagonal honeycomb core were investigated experimentally. The temperature distributions on the honeycomb core wall and the combined heat transfer rates through the porous layer were measured. The measurements of the heat transfer were accomplished using the guarded hot plate method. The honeycomb core wall was made of paper and large-mesh foamed resins were inserted into the honeycomb enclosures. The measurements were performed by varying the radiation parameters between 0.5 and 0.65, varying the temperature ratios between 0.01 and 0.1, and varying the Darcy-Rayleigh numbers between 5 and 80, and for a fixed aspect ratio H/L = 1. The experimental results for Nusselt numbers agreed well with our available numerical results. © 1999 Scripta Technica, Heat Trans Asian Res, 28(4): 295–306, 1999     

Involvement of Molecular Mechanisms between T/B Cells and IL-23: From Palmoplantar Pustulosis to Autoimmune Diseases

Palmoplantar pustulosis (PPP) is a disease that causes recurrent blisters and aseptic pustules on the palms and soles. It has been suggested that both innate and acquired immunity are involved. In particular, based on the tonsils and basic experiments, it has been assumed that T and B cells are involved in its pathogenesis. In addition, the results of clinical trials have suggested that IL-23 is closely related to the pathogenesis. This review describes PPP and the genetic background, the factors involved in the onset and exacerbation of disease and its relation to the molecular mechanism. In addition, we describe the usefulness of biological therapy and its implications in relation to the importance in pathology, the pathogenesis of PPP, the importance of the role of the IL-23–Th17 axis and IL-36 in PPP. Furthermore, we describe an animal experimental model of PPP, the efficacy and mechanism of action of guselkumab, an anti-IL-23 antibody, the latest research, and finally the possibility for it to be effective for other autoimmune diseases.     

Downregulation of the Cd38-Cyclic ADP-Ribose Signaling in Cardiomyocytes by Intermittent Hypoxia via Pten Upregulation

Sleep apnea syndrome (SAS) is characterized by recurrent episodes of oxygen desaturation and reoxygenation (intermittent hypoxia, IH), and it is a risk factor for cardiovascular disease (CVD) and insulin resistance/type 2 diabetes. However, the mechanisms linking IH stress and CVD remain elusive. We exposed rat H9c2 and mouse P19.CL6 cardiomyocytes to experimental IH or normoxia for 24 h to analyze the mRNA expression of the components of Cd38-cyclic ADP-ribose (cADPR) signaling. We found that the mRNA levels of cluster of differentiation 38 (Cd38), type 2 ryanodine receptor (Ryr2), and FK506-binding protein 12.6 (Fkbp12.6) in H9c2 and P19.CL6 cardiomyocytes were significantly decreased by IH, whereas the promoter activities of these genes were not decreased. By contrast, the expression of phosphatase and tensin homolog deleted from chromosome 10 (Pten) was upregulated in IH-treated cells. The small interfering RNA for Pten (siPten) and a non-specific control RNA were introduced into the H9c2 cells. The IH-induced downregulation of Cd38, Ryr2, and Fkbp12.6 was abolished by the introduction of the siPten, but not by the control RNA. These results indicate that IH stress upregulated the Pten in cardiomyocytes, resulting in the decreased mRNA levels of Cd38, Ryr2, and Fkbp12.6, leading to the inhibition of cardiomyocyte functions in SAS patients.