The O–O bond length is often used as a structural indicator to determine the valence states of bound O 2 ligands in biological metal–dioxygen intermediates and related biomimetic complexes. Here, we report very distinct O–O bond lengths found for three crystallographic forms (1.229(4), 1.330(4), 1.387(2) Å at 100 K) of a side-on iron–dioxygen species. Despite their different O–O bond distances, all forms possess the same electronic structure of Fe(III)–O 2 •– , as evidenced by their indistinguishable spectroscopic features. Density functional theory and ab initio calculations, which successfully reproduce spectroscopic parameters, predict a flat potential energy surface of an η 2 -O 2 motif binding to the iron center regarding the O–O distance. Therefore, the discrete O–O bond lengths observed likely arise from differential intermolecular interactions in the second coordination sphere. The work suggests that the O–O distance is not a reliable benchmark to unequivocally identify the valence state of O 2 ligands for metal–dioxygen species in O 2 -utilizing metalloproteins and synthetic complexes.

Singlet oxygen ( 1 O 2 ) has been recently identified as a key molecule against toxic Aβ aggregation, which is associated with the currently incurable Alzheimer's disease (AD). However, limited research has studied its efficiency against tau protein aggregation, the other major hallmark of AD. Herein, we designed and synthesized boron-dipyrromethene (BODIPY)−ruthenium conjugates and isolated three isomers. Under visible-light irradiation, the ε isomer can be photoactivated and efficiently generate singlet oxygen. Particularly, the complex demonstrated successful results in attenuating tauopathy�an appreciable decrease to 43 ± 2% at 100 nM. The photosensitizer was further found to remarkably promote neurite outgrowth and significantly increased the length and number of neurites in nerve cells. As a result of effective photoinduced singlet oxygen generation and proactive neurite outgrowth, the hybrid design has great potential for therapeutics for Alzheimer's disease.

Singlet oxygen (1O2) has been recently identified as the key mechanism for depressing β-amyloid (Aβ) accumulation and neurofibrillary tangles (NFTs). Slow cell internalization and short half-life of photosensitizing effects still impede the application of nanophotosensitizers for photodynamic therapy (PDT). The current major challenge of using spiropyran for PDT is the extremely short half-life of its ring-opened isomer, merocyanine. Merocyanine is the center of generation of 1O2. Here, we report that the complexation of spiropyran onto Au nanoparticles greatly enhances the stability of merocyanine (half-life is 91.6 h). Additionally, Au nanoparticles sharply decelerate the reversion of merocyanine back to spiropyran (a ring-closed form) by modifying the energy configuration of merocyanine, resulting in generation of a long-lived 1O2 phototherapy response (24 h) in the intracellular environment for depressing tau aggregation (a 32% reduction of NFT formation).

Carbon Monoxide (CO) plays an important role in signaling in the cells, making its use as a therapeutic tool highly intriguing. Reduced burst emissions are important to avoid the cytotoxicity...

Background Studies on health impact of lock-in job are mainly conducted in western countries with theory based on the value of individualism. We argued that the social-oriented concern should be considered in workers’ lock-in status in Chinese society. Methods Anonymous survey were conducted on 1102 workers of high-tech companies in Taiwan from October 2015 to January 2016 to assess their face need, lock-in status of job and burnout. Except separate into 3 groups by lock-in score, participants were categorized by the conflict of preference of job between themselves and their family. Chi-square test, ANOVA test, Person correlation test and regression were applied. Results Among 1102 participants, 18% had job that they did not prefer but their family prefer. Participants with higher face need and higher lock-in status had significantly higher risk of developing personal and work-related burnout. But the analysis using “lock-in Job for conflict of preference between themselves and their family” status showed more coherent result. Participants with job which “self not prefer but family do” had 2 times risk of having personal and work-related burnout (OR = 2.03 and 2.34). Participants with job which both themselves and their family not prefer had 4 times risk of having personal and work-related burnout (OR = 4.10 and 4.17). Conclusions Our study result indicated the importance to consider social-oriented job preference in lock-in status evaluation in Chinese culture. Workers’ lock-in status as their preference conflicting with their family’s preference showed significantly negative impact on their health.