Research on the catalytic activity of MNP-[Dop-OH]-CuBr2 nanocomposites: novel and stable reusable nanocatalysts for the synthesis of 1,3,5-triazine derivatives.

In recent years, magnetic nanocatalysts have been recommended as one of the best catalysts by chemists. Among magnetic nanoparticles, Fe3O4 nanoparticles are highly suitable due to their magnetic properties, chemical stability and low toxicity. These catalysts can be separated via magnetic separation after the chemical process is over and reused after regeneration. Owing to the importance of 1,3,5-triazine derivatives in pharmaceutical and medicinal chemistry, the synthesis of these compounds is always one of the important goals of organic chemists. In this research work, we first successfully synthesized CuBr2 immobilized on magnetic Fe3O4 nanoparticles functionalized with Dop-OH (prepared via the reaction of MNP-dopamine with 2-phenyloxirane) nanocomposites and then investigated their catalytic application in the synthesis of 1,3,5-triazine derivatives via an oxidative coupling reaction of amidine hydrochlorides and alcohols in air. Recycling experiments clearly revealed that MNP-[Dop-OH]-CuBr2 nanocatalysts could be reused for at least 8 times without much loss of catalytic activity.

Suppressing Dendritic Lithium Formation Using Porous Media in Lithium Metal-Based Batteries.

Because of its ultrahigh specific capacity, lithium metal holds great promise for revolutionizing current rechargeable battery technologies. Nevertheless, the unavoidable formation of dendritic Li, as well as the resulting safety hazards and poor cycling stability, have significantly hindered its practical applications. A mainstream strategy to solve this problem is introducing porous media, such as solid electrolytes, modified separators, or artificial protection layers, to block Li dendrite penetration. However, the scientific foundation of this strategy has not yet been elucidated. Herein, using experiments and simulation we analyze the role of the porous media in suppressing dendritic Li growth and probe the underlying fundamental mechanisms. It is found that the tortuous pores of the porous media, which drastically reduce the local flux of Li+ moving toward the anode and effectively extend the physical path of dendrite growth, are the key to achieving the nondendritic Li growth. On the basis of the theoretical exploration, we synthesize a novel porous silicon nitride submicron-wire membrane and incorporate it in both half-cell and full-cell configurations. The operation time of the battery cells is significantly extended without a short circuit. The findings lay the foundation to use a porous medium for achieving nondendritic Li growth in Li metal-based batteries.

Kinetically limited differential centrifugation as an inexpensive and readily available alternative to centrifugal elutriation.

When separating two species with similar densities but differing sedimentation velocities (because of differences in size), centrifugal elutriation is generally the method of choice. However, a major drawback to this approach is the requirement for specialized equipment. Here, we present a new method that achieves similar separations using standard benchtop centrifuges by loading the seperands as a layer on top of a dense buffer of a specified length, and running the benchtop centrifugation process for a calculated amount of time, thereby ensuring that all faster moving species are collected at the bottom, while all slower moving species remain in the buffer. We demonstrate the use of our procedure to isolate bacteria from blood culture broth (a mixture of bacterial growth media, blood, and bacteria).

[A novel COL4A5 splicing mutation causing Alport syndrome in a Chinese family].

OBJECTIVE: To identify the pathogenic mutation in a Chinese family with Alport syndrome. METHODS: Blood samples were collected from the members of the family. Direct DNA sequence analysis of the entire coding region and exon-intron boundaries of the COL4A5 gene was performed, and restriction fragment length polymorphism (RFLP) analysis was used to confirm the sequencing results and to test the mutation in all the family members and 200 controls. RESULTS: A novel splicing mutation of c.1517-1G to T in the COL4A5 gene was identified in all patients in the family. RFLP analysis did not detect this mutation in all the unaffected family members and the 200 controls. CONCLUSION: This data revealed a novel splicing mutation of c.1517-1G to T in the COL4A5 gene causing Alport syndrome in a Chinese family. Author's study enriched the spectrum of COL4A5 mutation associated with Alport syndrome.