Dynamic Covalent Synthesis of Crystalline Porous Graphitic Frameworks

Porous graphitic framework (PGF) is a two-dimensional (2D) material that has emerging energy applications. An archetype contains stacked 2D layers, the structure of which features a fully annulated aromatic skeleton with embedded heteroatoms and periodic pores. Due to the lack of a rational approach in establishing in-plane order under mild synthetic conditions, the structural integrity of PGF has remained elusive and ultimately limited its material performance. Here, we report the discovery of the unusual dynamic character of the C=N bonds in the aromatic pyrazine ring system under basic aqueous conditions, which enables the successful synthesis of a crystalline porous nitrogenous graphitic framework with remarkable in-plane order, as evidenced by powder X-ray diffraction studies and direct visualization using high-resolution transmission electron microscopy. The crystalline framework displays superior performance as a cathode material for lithium-ion batteries, outperforming the amorphous counterparts in terms of capacity and cycle stability. Insertion of well-defined, evenly spaced nanoscale pores into the two-dimensional (2D) layers of graphene invokes exciting properties due to the modulation of its electronic band gaps and surface functionalities. A bottom-up synthesis approach to such porous graphitic frameworks (PGFs) is appealing but also remains a great challenge. The current methods of building covalent organic frameworks rely on a small collection of thermodynamically reversible reactions. Such reactions are, however, inadequate in generating a fully annulated aromatic skeleton in PGFs. With the discovery of dynamic pyrazine formation, we succeeded in applying this linking chemistry to obtain a crystalline PGF material, which has displayed high electrical conductivity and remarkable performance as a cathode material for lithium-ion batteries. We envision that the demonstrated success will open the door to a wide array of fully annulated 2D porous frameworks, which hold immense potential for clean energy applications. We report the unusual dynamic characteristics of the C=N bonds in the pyrazine ring promoted under basic aqueous conditions, which enables the successful synthesis of two-dimensional porous graphitic frameworks (PGFs) featuring fully annulated aromatic skeletons and periodic pores. The PGF displayed high electrical conductivity and remarkable performance as a cathode material for lithium-ion batteries, far outperforming the amorphous counterparts in terms of capacity and cycle stability

Melatonin as a Potential Agent in the Treatment of Sarcopenia

Considering the increased speed at which the world population is aging, sarcopenia could become an epidemic in this century. This condition currently has no means of prevention or treatment. Melatonin is a highly effective and ubiquitously acting antioxidant and free radical scavenger that is normally produced in all organisms. This molecule has been implicated in a huge number of biological processes, from anticonvulsant properties in children to protective effects on the lung in chronic obstructive pulmonary disease. In this review, we summarize the data which suggest that melatonin may be beneficial in attenuating, reducing or preventing each of the symptoms that characterize sarcopenia. The findings are not limited to sarcopenia, but also apply to osteoporosis-related sarcopenia and to age-related neuromuscular junction dysfunction. Since melatonin has a high safety profile and is drastically reduced in advanced age, its potential utility in the treatment of sarcopenic patients and related dysfunctions should be considered

Supplementary Material for: The consistency between registered acupuncture-moxibustion clinical studies and their published studies and update status of registered information

Background: Few studies have analyzed the consistency between registered acupuncture-moxibustion clinical studies and their published research results as well as their update status of registered information. Methods: We searched for acupuncture-moxibustion clinical studies that were registered at the World Health Organization International Clinical Trials Registry Platform between 2013 and 2015 and collected data regarding their characteristics and update status. Published results of these registered studies were identified and compared with registered information. Results: A total of 425 registered acupuncture-moxibustion clinical studies were included; 379 (89.2%) of them were interventional studies, and the remaining 46 (10.8%) were observational studies. Forty-six studies (10.8%) were found to have published results, and 51 published articles were identified. Overall, 73.2% (311) of registered studies did not update the research status in time; 46.6% (198) stopped updating before recruiting; 21.6% (92) stopped updating after recruiting; and 4.9% (21) stopped updating after completion. Regarding the 46 studies with published results, 29 (63.0%) were considered to be affected by reporting bias. These reporting biases predominantly involved the omission of some predefined outcomes or endpoints (16 studies), contradictions regarding descriptions of sample sizes (9 studies), discrepancies in treatment measurements or group distribution (7 studies), and inconsistent treatment durations (4 studies). When compared with other studies, significant and various reporting biases could also be commonly found in fields other than acupuncture-moxibustion. Conclusions: There were many discrepancies between registered information and published reports on acupuncture-moxibustion, which could also be commonly observed in other fields. Moreover, a large proportion of registered studies did not update their research status in time. Efforts should be made to improve the reporting quality and timely updates