Chemerin, an 18 kDa protein secreted by adipose tissue, was reported to modulate immune system function through its binding to the chemerin receptor (chemerinR). We herein demonstrate that chemerin also influences adipose cell function. Our data showed 5 that chemerin and chemerinR mRNA expressions were highly expressed in adipose tissues, and that their expression levels were up-regulated in mice fed a high-fat diet. Both chemerin and chemerinR mRNA expression dramatically increased during the differentiation of 3T3-L1 cells and human preadipocytes into adipocytes. Furthermore, recombinant chemerin induced the phosphorylation of extracellular signal-regulated 10 kinases 1/2 (ERK 1/2) and lipolysis in differentiated 3T3-L1 adipocytes. Thus, the adipokine chemerin likely regulates adipocyte function by autocrine/paracrine mechanisms.

Recent research progress indicates a close link between ghrelin, a natural ligand of GH secretagogues receptor (GHS-R), and both the metabolic balance and body composition. To clarify the involvement of ghrelin and GHS-R in the process of adipogenesis, we measured the expression of GHS-R and peroxisome proliferator-activated receptor gamma 2 (PPAR-gamma 2) mRNA in rat adipocytes using semiquantitative RT-PCR methods. The levels of GHS-R mRNA increased by up to 4-fold in adipose tissue from epididymal and parametrial regions as the rat aged from 4-20 wk and were significantly elevated during the differentiation of preadipocytes in vitro. Ghrelin (10(-8) M for 10 d) stimulated the activity of glycerol-3-phosphate dehydrogenase and the differentiation of rat preadipocytes in vitro. Ghrelin treatment also significantly increased the levels of PPAR-gamma 2 mRNA in primary cultured rat differentiated adipocytes. In addition, isoproterenol (10(-8) M, 40 min)-stimulated lipolysis was significantly reduced by simultaneous ghrelin treatment in a dose-dependent manner in vitro. In conclusion, the expression of GHS-R in rat adipocytes increases with the age and during adipogenesis. Ghrelin in vitro stimulates the differentiation of preadipocytes and antagonizes lipolysis. Ghrelin may therefore play an important role in the process of adipogenesis in rats.

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resulting in relatively low data throughput. On the other hand, another type of the new memories based on a solid state We report a novel nonvolatile dual-layered electrolytic electrolyte [5], in which ions such as Ag+ or Cu+ move along resistance memory composed of a conductive Cu ion the applied field and form the conductive bridge in the activated layer and a thin insulator for the first time. An electrolyte, is a promising candidate from the viewpoints of ON/OFF mechanism of this new type memory is postulated high speed switching and low set/reset current. Previous as follows: Cu ions pierce through the insulator layer by studies on the memories, however, seem to show their applied electric field, the ions form a Cu conductive bridge in insufficient retention. the insulator layer, and this bridge dissolves back to the ion To realize both high speed switching and sufficient activated layer when the field is reversed. The 4 kbit memory retention, we have newly developed a dual-layered array with IT-IR cell structure was fabricated based on 180 electrolytic resistance memory utilizing Cu conductive bridge nm CMOS process. Set/reset pulses were 5 ns, 110 gtA and 1 combined with a thin insulator. ns, 125 gA, respectively. Those conditions provide large set/reset resistance ratio of over 2 orders of magnitude and Memory Design satisfactory retention. Essential characteristics for high capacity memories including superb scalability down to 20In a solid state electrolytic memory, metallic ions such as nmo, sufficient endurance up to 107 cycles and preliminary Ag+ or Cu+ play an essential role in fast forming a conductive data for 4-level memory are also presented. These bridge when the electric field is applied. But without the field, characteristics promise the memory being the next generation the bridge should steadfastly keep the shape for the data high capacity nonvolatile memory even before the scaling retention. It seems hard to solve these incompatible limitation of flash memories is encountered. characteristics within a single layer. Therefore we divided the role into respective two layers: the conductive ion activated Introduction layer and the resistance change layer of the insulator as shown in Fig. 1. The resistance change layer is thin enough An imminent scaling limit of flash memories accelerates for the activated ions to pierce through the layer rapidly in the search for the new memories and so far several types of the electric field. The conductive bridge is stable in the layer resistive memories are proposed, such as phase change when no electric field is applied. When the reverse field is memory [1, 2], oxide base resistance change memory [3, 4] applied, the bridge is dissolved back to the ion layer, where and so on. However, each memory seems to have inherent both the electric field and joule heat are thought to be main drawbacks such as large reset current and/or slow set speed, driving forces. Because the insulator layer is thin enough, o o a %^o Cu od 1 l z | CT e | og g uC Gd Cu-Te base conz u...

Since lithium salts are used as pharmaceutically active compounds against manic-depressive psychosis, there is a demand to monitor the lithium concentration in blood in the narrow range of 0.6-1.2 mM effectively and safely. Here we report on an optical sensor approach for the determination of Li+, based on the design and synthesis of a novel lithium fluoroionophore KLI-1 and its polymer immobilizable derivative KLI-2, and the application to an optode. The novel lithium fluoroionophores rely on a tetramethyl "blocking subunit" bearing 14-crown-4 as a Li+-selective binding site and 4-methylcoumarin as a fluorophore, intramolecularly connected to show ICT-type wavelength shift for ratiometric fluorescence measurements. The fluoroionophores showed high selectivity for Li+ with binding-induced blue shift in the fluorescence spectra, no response to major biological interfering cations (K+, Ca2+, Mg2+), a selectivity of log kLi+,Na+ = -2.4 over Na+ in solution, and no response to pH in the range of pH 3-10. A hydrophilic optode membrane with KLI-2 immobilized also showed good selectivity for Li+, pH independence in the physiological range (pH 6-8), and fully reversible signal changes. KLI-1 and KLI-2 are excellent Li+ fluorescent chemosensors that can be applied to quantitative measurements of lithium in clinical samples, although possible interference from Na+ has to be considered at the lower therapeutic level of Li+.

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Two new types of surface plasmon resonance (SPR) sensors that can determine the concentration of ammonium cations and urea were realized based on the previously reported theory of the absorption-based SPR measurement method. The change of the dielectric constant caused by the change of the light absorption characteristics of dyes incorporated in a sensing membrane phase is utilized in these SPR sensors. The determination of ions using the SPR sensor was realized by detecting the SPR signals of the minimum reflectance related to the change of absorption spectra of the dye in the ion optode membrane consisting of an ammonium-selective ionophore (TD19C6) and a lipophilic cationic dye (KD-M11) that shows absorption spectral changes due to protonation and deprotonation. A SPR enzyme sensor that can determine the concentration of urea was prepared by the combination of this ion optode membrane and an enzyme membrane based on urease. With the newly developed SPR sensors, the intensity changes of the reflectance at the fixed SPR resonance angle are monitored, which is different from conventional SPR sensors where usually the change of the SPR resonance angles is detected. In a continuous-flow experiment using the SPR ion sensor for NH4+ ion determination, a dynamic measurement range from 10(-5) to 10(-2) M was achieved. In the case of the enzyme-based SPR urea sensor, a dynamic range from 10(-4) to 10(-1) M was observed in a stopped-flow batch arrangement. It is expected that this sensing technique can be applied for the SPR-based detection of a wide range of low molecular weight analytes.