Background
Mount evidence from observational studies suggested that associations between sleep duration and the risks of mild cognitive impairment (MCI)/dementia or cognitive decline had been ...recognized.
Methods
To explore the precise and continuous effect of sleep duration on these risks, we conducted a dose–response meta-analysis to quantitatively assess it.
Results
Five prospective cohort studies and 4 cross-sectional studies were eligible for inclusion criteria, which involved 62937 individuals, and documented 2718 MCI/dementia cases and 5596 cognitive decline cases. The pooled RR per 1 h increases in sleep duration was 0.99 (95% CI 0.97–1.01,
I
2
= 62.40%,
P
= 0.02,
n
= 6) for cognitive decline risk, and 0.98 (95% CI 0.97–1.00,
I
2
= 0%,
P
= 0.42,
n
= 4) for MCI/dementia risk. Similar U-shaped non-linear relationship of sleep duration and the risks of MCI/dementia and cognitive decline was revealed, respectively (all
P
non-linearity
< 0.001), whose peaks are approximately 7 h.
Conclusion
In conclusion, 7 h sleep duration tends to acquire the least risk of MCI/dementia or cognitive decline; however, more well-designed randomized controlled trials are urgently needed to balance potential modifiers.
Water, as a green reaction medium, is safe, non-toxic, and rich in reserves on Earth, while visible light represents a renewable, clean, and abundant energy source. Organic transformations carried ...out under the irradiation of visible light in water are undoubtedly more attractive, and are in line with the concept of "green chemistry" to effectively minimize the environmental impact of chemical synthesis. This review focuses on the recent progress in visible-light-mediated organic transformations in water, and the related mechanisms are also discussed. Although great achievements have been made, they are just the tip of the iceberg and there is still great room for improvement. This review will facilitate the understanding of visible-light-mediated organic transformations in water and further stimulate the advancement of more novel relevant strategies.
Water is a green reaction medium, while visible light represents a renewable, clean, and abundant energy source. The recent advances in visible-light-mediated organic transformations in water are summarized.
Despite recent advance in bioinspired adhesives, achieving strong adhesion and sealing hemostasis in aqueous and blood environments is challenging. A hyperbranched polymer (HBP) with a hydrophobic ...backbone and hydrophilic adhesive catechol side branches is designed and synthesized based on Michael addition reaction of multi‐vinyl monomers with dopamine. It is demonstrated that upon contacting water, the hydrophobic chains self‐aggregate to form coacervates quickly, displacing water molecules on the adherent surface to trigger increased exposure of catechol groups and thus rapidly strong adhesion to diverse materials from low surface energy to high energy in various environments, such as deionized water, sea water, PBS, and a wide range of pH solutions (pH = 3 to 11) without use of any oxidant. Also, this HBP adhesive (HBPA) exhibits a robust adhesion to fractured bone, precluding the problem of mismatched surface energy and mechanical properties. The HBPA's adhesion is repeatable in a wet condition. Intriguingly, the HBPA is capable of gluing dissimilar materials with distinct properties. Importantly, introducing long alkylamine into this modular hyperbranched architecture contributes to formation of an injectable hemostatic sealant that can rapidly stop visceral bleeding, especially hemorrhage from deep wound.
A hyperbranched polymer adhesive fabricated using a ternary Michael addition reaction of hydrophobic multi‐vinyl monomers with dopamine demonstrates strong underwater adhesion to diverse materials without any oxidant. This is due to water‐triggered fast coacervation and increased outward exposure of catechols. Introducing long‐chain alkylamine contributes to the formation of an injectable hemostatic sealant that can rapidly stop visceral bleeding, especially hemorrhage from deep wound.
A sustainable and cost‐effective protocol for direct aminomethylation of imidazo‐fused heterocycles by decarboxylative coupling reaction of N‐phenylglycines with imidazo‐fused heterocycles in the ...presence of CsPbBr3 under the irradiation of visible light has been developed. This is the first example of CsPbBr3‐catalyzed aminomethylation of imidazo‐fused heterocycles. The eminent advantage of this work is in that, CsPbBr3 is easily prepared and can be used at least 5 times without obvious reduction in its activity, exhibiting high catalyst economic feature.
The mechanisms of N‐heterocyclic carbene (NHC)‐catalyzed dearomatization reaction of alkyl pyridinium have been intensively studied using the density functional theory (DFT) method. The ...chemoselectivity and stereoselectivity were both analyzed based on the established mechanisms. The computational results showed that the chemoselective C4‐addition occurred before the C2‐addition, which is mainly because the C4 atom was more reactive according to the local reactivity analysis. The stereoselectivity was also investigated, and the C−C bond formation step was identified as the stereoselectivity‐determining step. The C−H⋅⋅⋅F and O−H⋅⋅⋅N interactions are identified as the main factors that govern the stereoselectivity by NCI analysis, and the preferred product was the RS‐configuration. This theoretical investigation would provide a case for understanding and predicting the selectivity of the organocatalytic dearomatization reactions of alkyl pyridinium.
Organocatalysis: The mechanisms of NHC‐catalyzed dearomatization reaction of alkyl pyridinium have been studied by using DFT methods. The potential active sites are successfully predicted by using local reactivity index and the origin of stereoselectivity is disclosed by NCI analysis. This theoretical investigation would aid the understanding and prediction of the selectivity of the organocatalytic dearomatization reactions of alkyl pyridinium.
Although organic light‐emitting devices have been commercialized as flat panel displays since 1997, only singlet excitons were emitted. Full use of singlet and triplet excitons, ...electrophosphorescence, has attracted increasing attentions after the premier work made by Forrest, Thompson, and co‐workers. In fact, red electrophosphorescent dye has already been used in sub‐display of commercial mobile phones since 2003. Highly efficient green phosphorescent dye is now undergoing of commercialization. Very recently, blue phosphorescence approaching the theoretical efficiency has also been achieved, which may overcome the final obstacle against the commercialization of full color display and white light sources from phosphorescent materials. Combining light out‐coupling structures with highly efficient phosphors (shown in the table‐of‐contents image), white emission with an efficiency matching that of fluorescent tubes (90 lm/W) has now been realized. It is possible to tune the color to the true white region by changing to a deep blue emitter and corresponding wide gap host and transporting material for the blue phosphor. In this article, recent progresses in red, green, blue, and white electrophosphorescent materials for OLEDs are reviewed, with special emphasis on blue electrophosphorescent materials.
Red phosphorescent dye has already been commercialized since 2003. Highly efficient green phosphorescent emitter is underway of commercialization. Very recently blue phosphorescence approaching the theoretical efficiency has also been obtained, which overcomes the final obstacle against commercialization of full color display and white light sources from electrophosphorescent materials. In this article, recent progresses in red, green, blue, and white phosphorescent materials for OLEDs are reviewed, with special emphasis on blue electrophosphorescent materials.
The introduction of phosphorus functional groups into the skeleton of thioflavones is an attractive task and of great significance. Herein, a metal‐free visible‐light‐induced radical cascade ...cyclization was developed for the preparation of 2‐phosphorylated thioflavones from methylthiolated alkynones and phosphine oxides. In water as a green reaction medium, a large number of such 2‐phosphorylated thioflavones were prepared, catalyzed by 4CzIPN 1,2,3,5‐tetrakis(carbazol‐9‐yl)‐4,6‐dicyanobenzene under visible‐light irradiation. These reactions could be performed at ambient temperature and feature simple operation, wide reaction scope, and recyclability of aqueous media.
Let there be light: By using water as a reaction medium, a large number of 2‐phosphorylated thioflavones are prepared through the reaction of methylthiolated alkynones and phosphine oxides catalyzed by 4CzIPN 1,2,3,5‐tetrakis(carbazol‐9‐yl)‐4,6‐dicyanobenzene under visible‐light irradiation.
Polystyrene is a multifunctional plastic used to manufacture consumables with a wide range of applications. Some azo compounds can produce free radicals when heated, which can be used as initiators ...for styrene polymerization. However, thermal runaway could occur during the styrene bulk polymerization initiated by azodiisobutyronitrile (AIBN) due to the release of a large amount of heat. To obtain thermal hazard properties, differential scanning calorimetry (DSC) and accelerating rate calorimetry (ARC) were applied to this investigation. The DSC experimental results showed that the extrapolated onset temperature and exothermic peak temperature decreased gradually after adding the initiator, which indicated initiator AIBN promoted the polymerization. ARC experiment decoded dynamic thermal parameters such as apparent activation energy, adiabatic temperature rise, initial runaway temperature, maximum temperature and polymerization heat of the hybrid system. Finally, the experimental and calculation results showed that the heat released by the polymerization reaction was basically unchanged at different heating rates; as the initiator concentration increases, the heat released by the polymerization reaction also increases, the polymerization temperature is controllable below 35.1 ℃. These results are critical for reducing the risk of loss of control and designing intrinsically safer styrene production, storage and transport processes.
A transition‐metal‐free visible‐light‐promoted radical phosphorylation/cyclization of N‐allylbenzamides with phosphine oxides for the synthesis of phosphoryl‐substituted dihydroisoquinolones was ...developed under room temperature. This protocol features mild reaction conditions, simple operation, broad substrate scope as well as scale‐up ability.
A simple and efficient decarboxylative radical addition/cyclization strategy was developed, by which a wide range of benzimidazo2,1-aisoquinoline-6(5H)-ones were prepared in one-pot via reaction of ...functionalized 2-arylbenzoimidazoles and carboxylic acids in the presence of K2S2O8/AgNO3 under mild reaction conditions.
