The Effect of Sodium-Dependent Glucose Cotransporter 2 Inhibitor Tofogliflozin on Neurovascular Coupling in the Retina in Type 2 Diabetic Mice

We investigated the effect of tofogliflozin, a sodium-dependent glucose cotransporter 2 inhibitor (SGLT2i), on retinal blood flow dysregulation, neural retinal dysfunction, and the impaired neurovascular coupling in type 2 diabetic mice. Tofogliflozin was added to mouse chow to deliver 5 mg/kg/day and 6-week-old mice were fed for 8 weeks. The longitudinal changes in the retinal neuronal function and blood flow responses to systemic hyperoxia and flicker stimulation were evaluated every 2 weeks in diabetic db/db mice that received tofogliflozin (n =6) or placebo (n = 6) from 8 to 14 weeks of age. We also evaluated glial activation and vascular endothelial growth factor (VEGF) expression by immunofluorescence. Tofogliflozin treatment caused a sustained decrease in blood glucose in db/db mice from 8 weeks of the treatment. In tofogliflozin-treated db/db mice, both responses improved from 8 to 14 weeks of age, compared with vehicle-treated diabetic mice. Subsequently, the electroretinography implicit time for the oscillatory potential was significantly improved in SGLT2i-treated db/db mice. The systemic tofogliflozin treatment prevented the activation of glial fibrillary acidic protein and VEGF protein expression, as detected by immunofluorescence. Our results suggest that glycemic control with tofogliflozin significantly improved the impaired retinal neurovascular coupling in type 2 diabetic mice with the inhibition of retinal glial activation.     

A formation of compatible poly(vinyl alcohol)/alumina gel composite and its properties

A formation of poly(vinyl alcohol) (PVA)/alumina gel composite was investigated with a viewpoint of compatibility of the composite. An alumina sol was prepared from aluminium iso-propoxide (Al(iPro)₃). The alkoxide was hydrolyzed and the resultant hydrate was peptized to a clear sol with acetic acid. The composite were transparent in whole content of alumina. The effects of dispersed alumina on the sorption of water and mechanical properties of composite were examined. The composites containing PVA 40–50% are flexible. They are folded in various forms and can be drawn five times the initial length in humid state. The residues obtained by calcination to remove PVA at 600°C keep its original form and transparency.     

Pervaporation of methanol–water mixture by poly(γ-methyl L-glutamate) membrane and synergetic effect of their mixture on diffusion rate

The pervaporation behaviors of methanol–water by poly(γ-methyl L -glutamate) (PMLG) membrane at non-steady- and steady-state permeation were investigated. The values of t_1/2 (time required to reach a half value of steady-state permeation flux) for methanol and water changed and did not change with the component in feed, respectively. Both of the average diffusion coefficients for methanol–and water–PMLG from the mixture changed exponentially with the sorption amount of methanol by the synergetic effect on diffusion. The difference in behavior of non-steady and steady state diffusion was explained by whether D_o (diffusion coefficient at zero penetrant concentration) was influenced by the concentration distribution of penetrant in PMLG membrane.     

A comparison of different paging mechanisms for mobile IP

This paper proposes two Individual paging schemes, then presents a comparative analysis on the signaling cost functions of Mobile IP (MIP) with different paging protocols and paging schemes and investigates constructing optimal paging areas using discrete system model as a mobility model. In wireless mobile Internet, mobile hosts often visit foreign networks that might be far away from their home networks and the occurrences of their inter-domain movement are relatively rare. In this scenario, our analytical results show that paging, particularly individual paging, can significantly improve the total signaling cost of MIP. We show that Domain paging can bring about considerable cost saving compared to FA (Foreign Agent) paging. Our results also demonstrate the significant advantages of Individual Paging over Static Aggregate Paging. The results show that specifying the optimal paging area size is critical in saving signaling cost of MIP with paging support. Hung Tuan Do received the B.E. degree in Electrical Engineeing and Computer Science from Hanoi University of Technology, Vietnam, and the M.E. and the Ph.D. both from Gunma University, Japan. His research interests include Mobility Management, Wireless Internet and Mobile Ad hoc Networks. Yoshikuni Onozato is a Professor with Gunma University. His research interests are in satellite systems, computer communication networks and distributed computing systems and span the entire spectrum from the design and performance evaluation of these systems to their implementation. He is a member of IEEE, ACM, IPSJ, ORSJ and IEICE.     

Study of the curing process giving the rigid polyurethane foam by dynamic viscoelastic method

Dynamic viscoelastic properties of the rigid polyurethane foam, which is used in Japan as a thermal insulator for refrigerators were studied during the curing process using the RDS-7700 Dynamic Spectrometer. The curing process, in which large volume expansion and heat evolution occurred, was easily analyzed by this method. The apparent storage modulus (G′_app), the apparent loss modulus (G″_app), and the apparent loss tangent (tan δ_app) were measured as a function of cure time. The effects of the curing temperature and the amine catalyst on the curing process were investigated. It was found that the curing process proceeded through three stages: logarithm of G″_app (log G″_app) increased with increasing cure time in the first stage, log G″_app increased with increasing logarithm of cure time in the second, and the change of G″_app cannot be expressed simply in the final. Curing behavior can be estimated from changes of rheological parameters during the curing. The fluidity of reaction mixture can be also predicted from the peak time of tan δ_app.     

Fabrication of flat micro‐gap electrodes for molecular electronics

Recently, organic molecular electronic devices such as molecular thin‐film transistors have received considerable attention as possible candidates for next‐generation electronic and optical devices. This paper reports on fabrication technologies of flat metallic electrodes on insulating substrates with a micrometer separation for high‐performance molecular device evaluation. The key technologies of fabricating planar‐type electrodes are the liftoff method by the combination of bilayer photoresist with overhang profile, electron beam evaporation of thin metal (Ti and Au) films, and SiO₂‐CMP (Chemical Mechanical Polishing) method of CVD (Chemical Vapor Deposition)‐deposited TEOS (tetraethoxysilane)–SiO₂ layer. The raggedness of the electrode/insulator interface and the electrode surface of the micro‐gap electrodes were less than 3 nm. The isolation characteristics of fabricated electrodes were on the order of 10¹³ ohms at room temperature, which is sufficient for evaluating electronic properties of organic thin‐film devices. Finally, pentacene FET (Field Effect Transistor) characteristics are discussed fabricated on the micro‐gap flat electrodes. The mobility of this FET was 0.015 cm²/Vs, which was almost on the order of the previous results. These results suggest that high‐performance organic thin‐film transistors can be realized on these advanced electrode structures. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 152(2): 39–46, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20152     

An Approximate Method for Design and Analysis of an ALOHA System

We develop here an approximate method for the design and performance prediction of a multiaccess communication system which employs the ALOHA packet-switching technique. Our model is based on the use of a diffusion process approximation of an ALOHAlike system (with or without time-slotting). A simple closed-form solution for the variableQ(t), a variant of the number of backlog messages at timet, is given in terms of a few system and user parameters. Final results are expressed in terms of ordinary performance measures such as throughput and average delay. Several numerical examples are given to demonstrate the usefulness of the approximation technique developed.     

A copy network with shared buffers for large-scale multicast ATMswitching

An architecture for the copy network that is an integral part of multicast ATM switches is described. The architecture makes use of the property that the broadcast banyan network (BBN) is nonblocking if the active inputs are cyclically concentrated and the outputs are monotone. In the architecture, by employing a token ring reservation scheme, the outputs of the copy network are reserved before a multicast cell is replicated. By the copy principle, the number of copies requested by a multicast call is not limited by the size of the copy network so that very large multicast switches can be configured in a modular fashion. The sequence of cells is preserved in the structure. Though physically separated, buffers within the copy network are completely shared, so that the throughput can reach 100%, and the cell delay and the cell loss probability can be made to be very small. The cell delay is estimated analytically and by computer simulation, and the results of both are found to agree with each other. The relationship between the cell loss probability under various traffic parameters and buffer sizes is studied by computer simulation     

CONFORMATIONAL ANALYSIS OF 2-(DIPHENYLPHOSPHANYL)-N,N-DIMETHYL-1-BENZ AMIDE AND 2-(DIPHENYLPHOSPHANYL)-PHENYL-PYRROLIDIN-1-YL-METHANONE BY NMR SPECTROSCOPY

We have synthesized 2-(Diphenylphosphanyl)-N, N-dimethyl-1-benzamide (1) and 2-(Diphenylphosphanyl)- phenyl-pyrrolidin-1-yl-methanone (2), and examined their conformations on the basis of NMR spectral data. Conformational analysis of the compounds is useful in deducing the structure in which they are active as a catalyst. In the present NMR measurements, ¹H-X fg-JHMBC (field gradient J-Resolved Hetero-nuclear Multiple-Bond Correlation) spectroscopy was implemented as a tool for the determination of hetero-nuclear three bond, phosphorus and protons and carbon-protons coupling constants. By fitting a sine curve to the experimental data by the method of 3D J-resolved HMBC NMR measurements, accurate ⁿ J _HX coupling constants were obtained. From the coupling constants, the corresponding dihedral angles, H3-C2-C3-P, H12-C12-C11-P, H16-C16-C11-P, H18-C18-C17-P, and H22-C22-C17-P, of compounds (1) and (2) were determined. The optimized structures of the compounds were obtained by molecular orbital calculations in which the dihedral angles experimentally determined were used.     

ANALYSIS OF MUTAGENICITY OF NITROBENZANTHRONES BY MOLECULAR ORBITAL CALCULATIONS

3-Nitrobenzanthrone (3-NBA) detected in diesel exhaust was found to be a very strong mutagen. 9-NBA, however, is less potent than 3-NBA and 11-NBA is devoid of mutagenicity. To explain the difference in mutagenicity among the three isomers theoretically, we proposed the metabolic activation pathway of NBAs and performed molecular orbital calculations. In the pathway, NBAs are transformed to nitrosobenzanthrone, N-hydroxy-3-aminobenzanthrone (N-OH-ABA), N-acetoxy-3-aminobenzanthrone (N-AcO-ABA), and finally ultimate carcinogens to form NBA-DNA adducts. We calculated the heat of formation, HOMO and LUMO energy for parent molecules and their activated intermediates. The activation energy (Ea) was also calculated for the binding reaction of the ultimate carcinogens with the DNA bases. A correlation was found between the mutagenicity of NBAs and the LUMO energy of parent molecules and the intermediates, nitrosobenzanthrone, N-OH-ABA, and N-AcO-ABA. The Ea values were not correlated with mutagenicity. This indicates that the production rate and stability of ultimate carcinogens are more important in determining the mutagenicity than the reaction rate of their binding to DNA.