Reflection spectra of various kinds of oxide glasses and fluoride glasses in the vacuum ultraviolet region

Reflection spectra of silicate, borate, phosphate, fluorophosphate and fluoride glasses are studied in the spectral region of 2–13 eV in order to understand their dispersion behaviors in the visible region from the point of view of atomic structures.The absorption bands due to bridging oxygen ions or fluorine ions are found at 11.6 eV and 10.4–9.5 eV in silicate glasses, at 10.2 and 8.8 eV in borate glasses, at 9.5 eV in phosphate glasses, at 11.2 eV in fluorophosphate glasses and at 11 eV in fluorozirconate glasses.In silicate glasses, the bands due to nonbridging oxygen ions are found in the region 8.8-4.9 eV. They shift to lower energies with increasing ionic radius, in the order of Ca²⁺, Sr²⁺ and Ba²⁺, for the glasses containing low valency cations, while they shift to higher energies with increasing ionic radius, in the order of Ti⁴⁺, Zr⁴⁺ and Th⁴⁺ or in the order of Nb⁵⁺ and Ta⁵⁺, for the glasses containing high valency cations.In glasses containing large amounts of PbO, strong bands due to PB²⁺ ions appear in the lower energy regions of 6.3–5.6 eV and 5.2–4.7 eV.     

Temperature fluctuations in a LiNbO3 melt during crystal growth

The synthesis of calcium carbonate (CaCO₃) crystals from aqueous solutions containing sodium dodecyl sulfate (SDS), poly(N-vinyl-1-pyrrolidone) (PVP), or SDS/PVP complexes has been performed through a slow titration method. It was found that aragonite and calcite co-existed in the prepared crystals. The formation of aragonite in the precipitation systems without magnesium ions indicates that at ambient temperature ca. 26.0°C, initially formed amorphous CaCO₃ could also transfer into aragonite in the sedimentary phase, which indicates the controlling factor of organic additives in the nucleation and growth process of CaCO₃ crystals. The appearance of hexagonal crystals in the suspensible phase confirmed the hexagonal crystallization cell of vaterite, and revealed the colloidal-dispersion function of the SDS/PVP complex in the crystallization process of CaCO₃.     

Synthesis of leucine-enkephalin analogs containing α-amino squaric acid

Novel Leu-enkephalin analogs 10a-c in which the Tyr¹, Gly², or Gly³ residue of Leu-enkephalin 9 was replaced with α-amino squaric acid analog Sq-Tyr 8b or Sq-Gly 8a were synthesized starting from 14 or 18. Conformational analysis of 10a-c together with its model compound 26 and their opioid receptor binding activity were evaluated.     

A nanostructured skeleton catalyst: Suzuki-coupling with a reusable and sustainable nanoporous metallic glass Pd-catalyst

Nanoporous metallic glass Pd, which was fabricated by dealloying of a glassy metallic alloy Pd(30)Ni(50)P(20), exhibited a remarkable catalytic activity for the Suzuki-coupling reaction between iodoarenes and arylboronic acids under mild conditions. Moreover, the catalyst can be reused several times without a significant loss of catalytic activity.     

Photodissociation of pyrene dimer radical cation during the pulse radiolysis–laser flash photolysis combined method

Photodissociation of pyrene (Py) dimer radical cation (Py ₂ ^?+ ) giving pyrene radical cation (Py^?+) and Py and subsequent regeneration of Py ₂ ^?+ by association of Py^?+ and Py were directly observed during the pulse radiolysis–laser flash photolysis combined method at room temperature. When Py ₂ ^?+ was excited at the local excitation band with the 532-nm laser flash, the rapid growth and decay of monomeric Py^?+ were observed at 460 nm. The dissociation of Py ₂ ^?+ proceeded via a one-photon process to give the ground-state Py^?+(D₀) and Py in the quantum yield (Φ_diss) of (2.9 ± 0.9) × 10^?3. It was shown that Py^?+ decayed with a time constant of several tens of nanoseconds, indicating that the association of Py^?+ with Py regenerating Py ₂ ^?+ proceeds at a diffusion-controlled rate. The photodissociation proceeded from the lowest excited state of Py ₂ ^?+ , even when Py ₂ ^?+ was excited to the higher excited state. The difference between the Φ_diss value of Py ₂ ^?+ and that previously reported for naphthalene dimer radical cation (Np ₂ ^?+ ) is discussed.     

一种新型氧氮杂大环化合物的光合成

以乙腈为溶剂,二苯甲酮为光敏化剂,6,6’-二甲基-4,4’-(三亚甲二氧基)-二-2-吡喃酮与N,N’-亚甲基双丙烯酰胺经光二重[2+2]环加成反应,位置选择性地合成了一种新型氧氮杂大环化合物,其结构经1H NMR,12C NMR,FT-IR和HR-MS表征。最佳光反应条件为:1 3.2 mmol,n(1)∶n(二苯甲酮)=1.0∶1.5,于300 W光照18 h,收率37%。     

Neuroprotective effects of edaravone-administration on 6-OHDA-treated dopaminergic neurons

Background

A recent human clinical trial of an Alzheimer's disease (AD) vaccine using amyloid beta (Aβ) 1–42 plus QS-21 adjuvant produced some positive results, but was halted due to meningoencephalitis in some participants. The development of a vaccine with mutant Aβ peptides that avoids the use of an adjuvant may result in an effective and safer human vaccine.

Results

All peptides tested showed high antibody responses, were long-lasting, and demonstrated good memory response. Epitope mapping indicated that peptide mutation did not lead to epitope switching. Mutant peptides induced different inflammation responses as evidenced by cytokine profiles. Ig isotyping indicated that adjuvant-free vaccination with peptides drove an adequate Th2 response. All anti-sera from vaccinated mice cross-reacted with human Aβ in APP/PS1 transgenic mouse brain tissue.

Conclusion

Our study demonstrated that an adjuvant-free vaccine with different Aβ peptides can be an effective and safe vaccination approach against AD. This study represents the first report of adjuvant-free vaccines utilizing Aβ peptides carrying diverse mutations in the T-cell epitope. These largely positive results provide encouragement for the future of the development of human vaccinations for AD.