Local structure of LiCoO2 nanoparticles studied by Co K-edge x-ray absorption spectroscopy.

We have studied the local structure of LiCoO(2) nanoparticles by Co K-edge x-ray absorption spectroscopy as a function of particle size. Extended x-ray absorption fine structure data reveal substantial changes in the near neighbor distances and the associated mean square relative displacements with decreasing particle size. X-ray absorption near edge structure spectra show clear local geometrical changes with decreasing particle size, similar to those that appear in the charging (delithiation) process. The results suggest that the LiCoO(2) nanoparticles are characterized by a large atomic disorder confined to the Co-O octahedra, similar to the distortions generated during the delithiation, and this disorder should be the primary limiting factor for a reversible diffusion of Li ions when nanoparticles of LiCoO(2) are used as cathode material in rechargeable Li ion batteries.

Involvement of adenosine A1 receptors in forced walking stress-induced analgesia in mice.

We investigated the involvement of adenosine receptors on forced walking stress-induced analgesia using a formalin-induced paw-licking test in male mice. Exposure to forced walking stress for 6 h showed stress-induced analgesia in the second phase (10-30 min), but not in the first phase (0-10 min). In the second phase, forced walking stress-induced analgesia was blocked by theophylline, a nonselective adenosine-receptor antagonist and DPCPX, an adenosine A1-receptor antagonist, but not ZM 241385, an adenosine A2A-receptor antagonist. These findings suggest that adenosine A1 receptors are involved in the analgesic mechanism activated by the forced walking stress.

Age-related differences in forced walking stress-induced analgesia in mice.

We investigated the effects of aging on forced walking stress-induced analgesia using a formalin-induced paw licking test in male mice. Exposure to forced walking stress for 6 h showed forced walking stress-induced analgesia in all mice aged 4, 24 and 48 weeks in the second phase (10-30 min), but not in the first phase (0-10 min). In the second phase, the degree of stress-induced analgesia was age-dependent (4 > 24 > 48 weeks). LY-235959, a competitive N-methyl-D-aspartate (NMDA) receptor antagonist, blocked forced walking stress-induced analgesia in mice aged 4 and 24 weeks, but not in those aged 48 weeks. Naloxone did not antagonize forced walking stress-induced analgesia in mice in any of the age groups. The present study suggests that the degree of forced walking stress-induced analgesia depends on the age of mice and confirms previous findings that forced walking stress-induced analgesia is involved in the nonopioid system via NMDA receptors.

Giant hydronephrosis due to a ureteral stone, and elevated serum levels of CA 19-9.

CA 19-9 is a widely used tumor marker. However, an elevation in serum CA 19-9 can occur in some patients with benign disorders such as cholecystolithiasis in the absence of tumor. We treated a case of acquired ureteral stone-induced giant hydronephrosis with markedly elevated serum CA 19-9 values. After nephrectomy, the serum CA 19-9 level returned to normal. No malignant cells were found in the tissues of the resected kidney. Localization of CA 19-9 was confirmed by immunohistochemical staining of the renal pelvic mucosa. A detailed case report is presented with a review of the literature.

Biomimetic Pathways for Assembling Inorganic Thin Films

Living organisms construct various forms of laminated nanocomposites through directed nucleation and growth of inorganics at self-assembled organic templates at temperatures below 100°C and in aqueous solutions. Recent research has focused on the use of functionalized organic surfaces to form continuous thin films of single-phase ceramics. Continuous thin films of mesostructured silicates have also been formed on hydrophobic and hydrophilic surfaces through a two-step mechanism. First, under acidic conditions, surfactant micellar structures are self-assembled at the solid/liquid interface, and second, inorganic precursors condense to form an inorganic-organic nanocomposite. Epitaxial coordination of adsorbed surfactant tubules is observed on mica and graphite substrates, whereas a random arrangement is observed on amorphous silica. The ability to process ceramic-organic nanocomposite films by these methods provides new technological opportunities.

Change in responsiveness of airway and beta-adrenoceptor in guinea pigs.

Allergen inhalation challenge resulted in significant (p < 0.05) increase in airway responsiveness to methacholine soon after immediate airway response (IAR) in guinea pigs actively sensitized with inhaled ovalbumin (OA) in vivo. We have investigated the involvement of thromboxane (Tx) A2 and platelet activating factor (PAF) in this airway hyperresponsiveness (AH). Pretreatment with CS-518, a selective thromboxane synthetase inhibitor, significantly inhibited both IAR (p < 0.07) and AH (p < 0.01), while pretreatment with WEB 2086, a PAF receptor antagonist, significantly inhibited only IAR (p < 0.05), but not AH after IAR. Propranolol, when inhaled before OA exposure, had no effect on bronchomotor tone, but if inhaled after IAR, it caused immediate death of guinea pigs. This result suggests that hyperresponsiveness of beta-adrenoceptor to propranolol may be induced by IAR. Examination of bronchoalveolar lavage (BAL) fluid revealed that no changes in cellular content were observed 60 min after OA exposure. In vitro, responsiveness of tracheal smooth muscle to carbachol was not changed by sensitization. Furthermore, anaphylactic reaction in vitro had no effect on the responsiveness. We conclude that airway responsiveness increases soon after IAR when infiltration of inflammatory cells is not yet found in vivo. It is also suggested that TxA2 but not PAF is involved in AH. Hyperresponsiveness to propranolol after IAR in OA sensitized guinea pigs illustrates the possibility of changes in function of beta-adrenoceptor after IAR.