Sol-Gel Technology as Reflected in Journal of Sol-Gel Science and Technology

Journal of Sol-Gel Science and Technology started as unique journal devoted to sol-gel science and technology in 1993. First, papers so far published in the Journal were intoduced. It was shown that the titles of invited papers and special issues show the broadening of the sol-gel area. Second, the change of the research tendency was conjectured from the four proceedings volumes. It was shown that the increase of importance of a particular class of materials and appearance of emergent materials are reflected in the title of the paper.     

Thermally Stabilized Fiber-Bragg-Grating Vibration Sensor Using Servo Motor Control

A fiber-Bragg-grating (FBG) vibration sensor, in which an FBG acts as an intensity-modulator for incident narrow spectrum light such as a laser, is thermally stabilized. Sensitivity of the sensor is kept constant over a wide range of temperature by feeding back a fraction of the output signal into the laser source in such a way that by shifting the oscillation wavelength of the laser the dc component of the detected photocurrent remains unchanged regardless of change in the environmental temperature. Variation in the sensor sensitivity is reduced to as small as 3 dB after the stabilization, although it is more than 55 dB without the stabilization.     

Determination of oxycodone and hydrocotarnine in cancer patient serum by high-performance liquid chromatography with electrochemical detection.

We developed an HPLC procedure using electrochemical detection for the quantitation of oxycodone and hydrocotarnine in cancer patients serum. An eluent of methanol:acetonitrile:5 mM pH 8 phosphate buffer (2:1:7) was used for the mobile phase. The calibration curve was linear in the range from 10 ng/mL to 100 ng/mL. The recovery of oxycodone and hydrocotarnine was 97.2% and 90.5%, respectively. The relative standard deviations within-runs and between-runs for the assay of oxycodone or hydrocotarnine were less than 4.8%. The method developed here was better than the method reported previously.     

Potentiometric determination of bromate using an Fe(III)-Fe(II) potential buffer by circulatory flow-injection analysis.

A method for the potentiometric determination of bromate by circulatory flow injection analysis (CFIA) is described. The procedure involves the use of an Fe(III)-Fe(II) potential buffer solution, which is recycled via a reservoir. The analytical method is based on a linear relationship between the concentration of bromate and a very transient potential change in the electrode potential due to the generation of intermediate bromine during the reaction of bromate with the Fe(III)-Fe(II) potential buffer solution, which also contains NaBr, (NH4)6Mo7O24 and H2SO4. An aliquot (5 microl) of a bromate sample solution was injected into the stream of the potential buffer solution, 100 ml of which was circulated at a flow rate of 1 ml/min; the potential buffer solution stream was then returned to the reservoir after passing through a flow-through redox electrode detector. A potential change due to the reaction of the injected sample with the potential buffer in a reaction coil was measured with the detector in the form of a peak signal. The effects of the bromide, sulfuric acid and Fe(III)-Fe(II) concentrations in the potential buffer, and length of the reaction coil on the peak heights were examined in order to optimize the proposed CFIA method. The analytical sensitivities to bromate were 5.6 mV/microM for 1 x 10(-2) M and 30.9 mV/microM for 1 x 10(-3) M in the concentration of Fe(III)-Fe(II) in a potential buffer solution containing 0.35 M NaBr, 0.2% (NH4)6Mo7O24 and 1 M H2SO4. The detection limit of bromate obtained by a 1 x 10(-3) M Fe(III)-Fe(II) potential buffer solution was 0.02 microM (2.5 ppb). The numbers of repetitive determinations in which the relative sensitivities within 5% were regarded as being tolerated were ca. 4000 and 2000 for the use of only 100 ml of 1 x 10(-2) M and 1 x 10(-3) M Fe(III)-Fe(II) potential buffer solution, respectively.     

Photofunctional Nanomodulators for Bioexcitation

A single organism comprises diverse types of cells. To acquire a detailed understanding of the biological functions of each cell, comprehensive control and analysis of homeostatic processes at the single‐cell level are required. In this study, we develop a new type of light‐driven nanomodulator comprising dye‐functionalized carbon nanohorns (CNHs) that generate heat and reactive oxygen species under biologically transparent near‐infrared (NIR) laser irradiation. By exploiting the physicochemical properties of the nanohorns, cellular calcium ion flux and membrane currents were successfully controlled at the single‐cell level. In addition, the nanomodulator allows a remote bioexcitation of tissues during NIR laser exposure making this system a powerful tool for single‐cell analyses and innovative cell therapies.     

Weil-Petersson geometry of Teichmüller–Coxeter complex and its finite rank property

On a Teichmüller space, the Weil-Petersson metric is known to be incomplete. Taking metric and geodesic completions result in two distinct spaces, where the Hopf-Rinow theorem is no longer relevant due to the singular behavior of the Weil-Petersson metric. We construct a geodesic completion of the Teichmüller space through the formalism of Coxeter complex with the Teichmüller space as its non-linear non-homogeneous fundamental domain. We then show that the metric and geodesic completions both satisfy a finite rank property, demonstrating a similarity with the non-compact symmetric spaces of semi-simple Lie groups.     

Metal Ionically-controlled Optical Signaling Based on a Chromoionophore-derived Calix[4]crown

A chromoionophore-derived calix[4]crown, 1 , possessing an effective signal-controllable function by metal ionic inputs has been newly synthesized, whose function is mainly of our interest, by transforming the process of receptor activation to one that may be detected by an optical signal (i.e. color change), the basic feature of antagonist-agonist competition may be reproduced readily and visually detected. The process would be particularly new within the field of optical read-out receptors. Further, from the standpoint of material sciences, the controllable signal function may not only be welcome for molecular information processing, but also contribute to the design of new sensory materials.