火星探测和天体矿物手性

从地球到月球到火星,人类一直没有停下探矿寻宝的脚步。从冰洲石到水晶到紫水晶,这些晶莹剔透矿石所呈现的光学现象给科学家带来“光是什么”和“手性起源”的百折不挠探究,贯穿整个科学发展史,促进科学、技术和现代社会进步,并将持续为未来科技发展带来不可估量的影响。

The Effects on the Cutting Propagation of Cinnamomum micranthum in Different Seasons

Cinnamomum micranthum is one of China Third-class Endangered Tree Species. The seedlings of C. micranthum are difficult to obtain. It is important to study the cutting propagation of C. micranthum in different seasons to improve the rooting rate for providing seedling propagation technique for the afforestation industry. In this study,the optimal season for the cutting propagation of C. micranthum was summer( May),providing 80. 6% rooting rate. The rooting rate in Summer was 33. 4% higher than that in Spring( March). This technique is important to make the best use of rare C. micranthum resources and to provide plenty of seedlings for afforestation and greening industry.

NMR signal separation of ionic liquids by poly( sodium-p-styrenesulfonate)-assisted chromatographic NMR spectroscopy--Dedicated to Professor Xiuwen Han on the occasion of her 80th birthday

Diffusion-ordered nuclear magnetic resonance spectroscopy(DOSY),dubbed chromato-graphic NMR spectroscopy,can be used to simultaneously distinguish and identify the structures of components in a mixture according to their different diffusion coefficients.In order to improve the resolution of DOSY on the diffusion dimension,a lot of matrices have been developed to expand the application of this technique in mixture analysis.However,there is no matrix to detect the mixture of ionic liquids(ILs).Herein,we introduced a new matrix,poly(sodium-p-styrenesulfonate)(PSSNa),which can be used to fully separate the signals of a mixture of different ILs.The mixture of three imidazolium ILs of 1-butyl-3-methylimidazolium bromide,1-allyl-3-vinylimidazolium bromide and 1-arboxymethy-3-methylimidazolium chloride could be fully distinguished by virtue of their different interactions with PSSNa.We also investigated the influences of PSSNa amount,IL con-centration and solution pH value on the signal resolution of mixtures.This work provides a scientific reference for the analysis of the other IL analytes.

Growth and Optical Applications of Centimeter-Long ZnO Nanocombs

Ultralong ZnO nanocombs have been synthesized on silicon substrates with a high growth rate of~7μm/s using a simple“thermal evaporation and condensation”method promoted by Cu catalysts.The lengths of the ZnO nanocombs range from several millimeters to more than one centimeter and the diameters of the branches are about 300 nm.The growth mechanism of the ultralong nanocombs and the catalytic behavior of the copper are discussed.The nanocombs were readily separated and their applications as optical polarizer and grating were investigated.The results show that the ultralong ZnO nanocombs can act as effective optical components in miniaturized integrated optics systems.

NMR Studies on the Interaction between Oncogene RET G-Quadruplex and Berberine

of main observation and conclusion RET G-quadruplex DNA(G4-DNA)is formed in the promoter region of RET protein,which is involved in the initiation and progression of human cancers.Berberine inhibits cancer cell growth through interactions with RET G4-DNA,but how it binds to RET G4-DNA remains unknown.Previously,we reported that colchicine selectively bound to RET G4-DNA,but the structural basis of its binding selectivity is still unclear.Here,mainly by NMR,we demonstrated how berberine bound to RET G4-DNA in a means different from colchicine,and implied several key determinants for small molecules specifically binding to one G4-DNA.

Trimetaphosphate-induced chiral selection between amino acid and nucleoside using ^(15)N-^(31)P coupling NMR

Life on Earth uses a common set of L-amino acids(L-aa)to construct proteins and D-nucleosides(D-Nu)to form nucleic acids,which serve as the carrier of genetic information.Herein,we reveal the in-trinsic mechanism of chiral selection of L-aa and D-Nu from the perspective of chemical origin of life.This work employed^(15)N-labeled L-aa and performed one-pot synthesis of nucleotide amidate of amino acid(N-aa-NMP)using equal amounts of L-^(15)N-aa and D-^(14)N-aa with D-/L-Nu in the aqueous solution of trimetaphosphate,generating L-^(15)N-aa-NMP and D-^(14)N-aa-NMP,respectively.The ^(31)P-NMR data indicated that L-aa was preferentially selected during the formation of N-aa-NMP in the presence of D-Nu.Surpris-ingly,D-aa was preferred over L-aa in the presence of L-Nu.Further analysis revealed that L-^(15)N-aa-D-NMP vs.D-^(14)N-aa-L-NMP and D-^(14)N-aa-D-NMP vs.L-^(15)N-aa-L-NMP were mirror isomers of each other,respec-tively.These data suggest that there could be a set of chiral systems opposite to that on Earth,which infers there might be a world of life that is a mirror image of the Earth.