RESUMO
A face-centered-cubic (FCC) YH3 phase is known to be stable only under high pressure (HP) of more than gigapascal order, and it reverts to the hexagonal YH3 ambient-pressure phase when the pressure is released. We previously found that the FCC YH3 can be stabilized even at ambient pressure by substituting Y for 10 mol % Li (LiH-stabilized YH3, LSY). The LSY was synthesized by heat treatment under gigapascal HP, but this process is unfavorable for mass production; that is, only a few tens of milligrams of a sample can be obtained in a single batch. In this study, we overcame this problem by applying a ball milling (BM) process for synthesizing the LSY phase, and the yield by the BM process reached on the order of grams. We confirmed that the structure of the BM sample was the same as that of the HP sample by X-ray diffractometry, Raman spectroscopy, and neutron total scattering pair distribution function analyses. The crystallinity of the BM sample, however, was lower than that of the HP sample. The difference in the crystallinity affects the thermal stability of the LSY. The BM sample with a lower crystallinity released hydrogen at a lower temperature. The BM sample was found to reversibly desorb/absorb hydrogen maintaining its initial FCC structure when the rehydrogenation temperature was at 423 K. However, when the rehydrogenation temperature of BM sample was more than 573 K, the FCC structure changed to the hexagonal ambient pressure phase due to thermal instability of FCC phase for the BM sample.
RESUMO
Coral reef degradation due to various local stresses, such as nutrient enrichment and terrestrial run-off into coastal waters, is an increasing global concern. Inorganic phosphates have been considered to possibly inhibit skeleton formation in corals. Despite many studies available on the effects of nutrients on corals, a clear consensus on how nutrients exert deteriorative effects on corals has not been established satisfactorily. In this study, we examined the effects of phosphates and nitrates on in vitro aragonite CaCO3 formation by using biogenic polyamines and in vivo aragonite formation in the skeleton of juvenile Acropora digitifera corals. We showed that the phosphates at similar concentrations clearly inhibited both in vitro and in vivo CaCO3 formation. In contrast, nitrates inhibited neither in vitro aragonite CaCO3 formation nor in vivo aragonite formation in juvenile coral skeleton. Furthermore, our findings showed that inhibition of coral skeleton formation was due to absorption of phosphate on the skeleton, which inorganically inhibited normal development of juvenile coral skeleton.
Assuntos
Antozoários/efeitos dos fármacos , Antozoários/crescimento & desenvolvimento , Carbonato de Cálcio/metabolismo , Fosfatos/efeitos adversos , Animais , Calcificação Fisiológica/efeitos dos fármacos , Carbonato de Cálcio/química , Nitratos/efeitos adversos , Água do Mar/química , Poluentes Químicos da Água/efeitos adversosRESUMO
We examined the role of carotenoid-binding protein (CBP) in yellow cocoon pigmentation. First, using yellow or white cocoon races, we investigated the linkage between the yellow pigmentation and CBP expression. CBP was expressed only in the silk gland of the yellow cocoon races, which utilize carotenoids for cocoon pigmentation. Furthermore, CBP expression in the silk glands of day 1-7 fifth instar larvae matched the period of carotenoid uptake into the silk gland. Finally, we gave double-stranded CBP RNA to Bombyx mori (B. mori) larvae to induce RNA interference. The significantly reduced expression of CBP in the silk gland of fifth instar larva was confirmed on day 4 and a decrease in yellow pigmentation was observed in the cocoon. We showed that CBP plays a key role in the yellow cocoon pigmentation caused by carotenoids.
Assuntos
Bombyx/fisiologia , Carotenoides/metabolismo , Proteínas de Transporte/fisiologia , Proteínas de Insetos/fisiologia , Pigmentação/fisiologia , Animais , Bombyx/genética , Proteínas de Transporte/biossíntese , Proteínas de Transporte/genética , Sistema Digestório/metabolismo , Glândulas Exócrinas/metabolismo , Immunoblotting , Proteínas de Insetos/biossíntese , Proteínas de Insetos/genética , Larva/fisiologia , Interferência de RNA , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/farmacologiaRESUMO
BACKGROUND AND STUDY AIMS: l-Menthol (LM), sprayed on the distal gastric mucosa, is a safe antispasmodic agent used during esophagogastroduodenoscopy (EGD). However, it seems to affect gastric mucosal endoscopic findings. Therefore, we evaluated whether LM causes specific changes and impacts the endoscopic morphology of gastric lesions. PATIENTS AND METHODS: A total of 98 patients scheduled to undergo EGD were randomly assigned to receive LM solution (160âmg of 0.8â% LM added to 2.5âmL of indigo carmine [IC]; nâ=â49; LM group) or decuple-diluted IC solution without LM (nâ=â49; placebo group). We compared the incidence of specific mucosal changes and the difference in the endoscopic findings of several gastric lesions between these groups. RESULTS: Annular-reticular - like mucosal changes appeared immediately after the administration of LM solution. This change was observed in 71.4â% of the LM group compared with 12.2â% of the placebo group (Pâ<â0.01). In the placebo group, this change was observed in 14.7â% of subjects with atrophic gastritis compared with 6.7â% of those without atrophic gastritis (Pâ=â0.39), whereas in the LM group, this change was observed in 84.8â% of subjects with atrophic gastritis compared with 43.8â% of those without atrophic gastritis (Pâ<â0.01). Most early gastric cancers, erosions, and ulcers observed in this study became well demarcated after LM administration, although the incidence of gastric lesions did not differ significantly between the two groups. CONCLUSION: LM changes the gastric mucosa into edematous mucosa, and this occurs more frequently in atrophic gastric mucosa than in pathologic lesions. LM may facilitate the demarcation of pathologic gastric lesions without intestinal metaplasia.