Chiral plasmonic nanostructure of twistedly stacked nanogaps

Nanogap plasmonic structures with strong coupling between separated components have different responses to orthogonal-polarized light, giving rise to giant optical chirality. Here, we proposed a three-dimensional(3D) nanostructure that consists of two vertically and twistedly aligned nanogaps, showing the hybridized charge distribution within 3D structures.It is discovered that the structure twisted by 60° exhibits plasmonic coupling behavior with/without gap modes for different circular-polarized plane waves, showing giant chiral response of 60% at the wavelength of 1550 nm. By controlling the disk radius and the insulator layer, the circular dichroism signal can be further tuned between 1538 and 1626 nm.     

微波波谱法研究水与有机/生物分子的分子配合物

微波波谱法是一种高灵敏度、高分辨率的研究分子系统内部动力学及超精细结构的方法,能解决许多其他方法难以解决的化学与物理领域具有挑战性的难题。本文综述了微波波谱法研究水分子与有机或生物分子形成分子配合物的内部动力学过程,详细讨论了不同类型的有机或生物分子与水分子形成的分子配合物,介绍了水在分子配合物中作为质子给体和质子受体的动力学,形成分子配合物后水分子和配体分子的隧道运动、结构和构象变化等动力学过程,并讨论了分子配合物中水分子和有机或生物分子的内部运动、相互作用键的强度、对称性影响隧道动力学特性。最后,展望了微波波谱法的发展方向。     

Decarbonylative CC Bond‐Forming Reactions of Saccharins by Nickel Catalysis: Homocoupling and Cycloaddition

Decarbonylation of saccharins by nickel catalysis enables two kinds of C?C bond‐forming reactions; homocoupling of saccharins to form biaryls and cycloaddition with alkynes to form benzosultams. The former represents the first reported nickel‐catalyzed decarbonylative C?C homocoupling reaction, whereas the latter constitutes a powerful method to pharmaceutically relevant benzosultams. The reactions proceed with good functional‐group tolerance and excellent regioselectivity.     

Flux-driven cellular precipitation in open system to form porous Cu3Sn

Recently, a new morphology of porous Cu₃Sn with lamellar structure is observed. Several possible explanations of the formation are proposed and compared. The most reasonable one seems to be the one based on a theory of flux-driven cellular precipitation in open system. Outflux of Sn from Cu₆Sn₅ generates simultaneously supersaturation with vacancies and with copper leading to the eutectoid-like transformation β → α + γ (where γ is void). The transformation is complete due to a complete outflux of Sn from the Cu₆Sn₅ phase. Simple formulae for prediction of the lamellar structure parameters and the propagation velocity are obtained and compared reasonably with experimental data. The suggested model can be interpreted as one more case of the flux-driven phase transformations in open systems.     

Comparisons of pharmacokinetics and NO‐releasing of nitrofibriate and fenofibrate after oral administration in rats

Nitrofibriate, a new compound of hypolipidemic, is modified based on fenofibrate. Both of them are used for prevention and treatment of cardiovascular diseases. In this study, an accurate and sensitive analytical method of reversed‐phase high‐performance liquid chromatography was developed to determine fenofibric acid, which is an active metabolite of both nitrofibriate and fenofibrate in rat plasma. This method was validated and successfully applied to pharmacokinetic study of nitrofibriate and fenofibrate after oral administration. The results suggested that the pharmacokinetic behavior of nitrofibriate followed a nonlinear process, while fenofibrate was linear, demonstrating that the two drugs were different in pharmacokinetic behaviors. Moreover, the effect of fenofibrate and nitrofibriate on releasing NO in rat serum was explored. This study showed that nitrofibriate, as a nitric oxide donor, could slowly release nitric oxide in vivo. This study provided a biopharmaceutical basis for further study of nitrofibriate.     

Lead optimization mapper: automating free energy calculations for lead optimization

Alchemical free energy calculations hold increasing promise as an aid to drug discovery efforts. However, applications of these techniques in discovery projects have been relatively few, partly because of the difficulty of planning and setting up calculations. Here, we introduce lead optimization mapper, LOMAP, an automated algorithm to plan efficient relative free energy calculations between potential ligands within a substantial library of perhaps hundreds of compounds. In this approach, ligands are first grouped by structural similarity primarily based on the size of a (loosely defined) maximal common substructure, and then calculations are planned within and between sets of structurally related compounds. An emphasis is placed on ensuring that relative free energies can be obtained between any pair of compounds without combining the results of too many different relative free energy calculations (to avoid accumulation of error) and by providing some redundancy to allow for the possibility of error and consistency checking and provide some insight into when results can be expected to be unreliable. The algorithm is discussed in detail and a Python implementation, based on both Schrödinger’s and OpenEye’s APIs, has been made available freely under the BSD license.     

Influence measures in ridge regression when the error terms follow an Ar(1) process

Influence concepts have an important place in linear regression models and case deletion is a useful method for assessing the influence of single case. The influence measures in the presence of multicollinearity were discussed under the linear regression models when the errors structure is uncorrelated and homoscedastic. In contrast to other article on this subject, we consider the influence measures in ridge regression with autocorrelated errors. Theoretical results are illustrated with a numerical example and a Monte Carlo simulation is conducted to see the effect autocorrelation coefficient, strength of multicollinearity and sample size on leverage points and influential observations.     

A New Approach to the Synthesis of Poly‐Functionalized Pyrano[2,3‐d]Pyrimidines Derivatives via Microwave‐Assisted Multi‐Component Reactions without Catalyst

A facile microwave‐assisted synthesis of pyrano[2,3‐d]pyrimidines derivatives is accomplished via reactions of 4‐arylmethylene‐2‐phenyloxazol‐5(4H)‐ones with pyrimidine‐4,6‐diol in ethylene glycol. The reaction is simple to perform and occurs under mild conditions with broad scope of applicability.     

Preface: Current research progress on mechanics of high speed rail

The construction and operation of high-speed rail（HSR）grid within the past two decades in China,in terms of the scale,may be possibly comparable to any national-wide construction in the history of China,even the Great Wall.By counting railways with commercial train service at the speed of200 km/h,China has the world’s longest HSR network with over 19 369.8 km of track in service today and this number