Pressure Effects on the Cooperative Jahn-Teller Distortion in AMnF 4 (A=Na,Tl)

This work investigates the Optical Absorption spectrum of the AMnF 4 layer perovskites of Mn 3+ , and its variation with the pressure. We show that the crystal-field transition energies and their pressure shifts provide a very useful information about the local structural changes in the \hbox{MnF}_6^{3-} complex and how it changes with the pressure, once the correlations between crystal-field electronic structure and coordination geometry around Mn 3+ has been established. Along this work we demonstrate that the equatorial and axial distances decrease from 1.844 to 1.813 + , and from 2.167 to 2.090 + , respectively, in the 0-100 kbar range, leading to a partial reduction of the Jahn-Teller distortion.     

Modeling the binding of peptides on carbon nanotubes and their use as protein and DNA carriers

An in-depth study of a novel functionalization of carbon nanotubes for their application as protein and DNA carriers is presented. First, the optimum conditions for the dispersion of single-walled carbon nanotubes (SWCNTs) with amphiphilic polypeptides were obtained, and the SWCNT–polypeptide complexes were characterized by different techniques (UV–Vis-NIR, CD, and AFM). Based on the properties of the SWCNT–polypeptide complexes, a model that characterizes the adsorption of natural proteins onto SWCNT was described for the first time. This model predicts the adsorption of natural proteins on SWCNTs based on the protein structure and composition, and therefore, allows the design of methods for the preparation of SWCNT–protein complexes. Besides, the use of cationic-designed amphiphilic polypeptides to disperse SWCNTs is applied for subsequent and efficient binding of DNA to carbon nanotubes by a bilayer approach. Therefore, in this article, we develop procedures for the use of SWCNTs as protein and DNA carriers. The systems were delivered into cells showing that the efficiency of delivery is affected by the charge of the complexes, which has important implications in the use of SWCNT as platforms for protein and DNA binding and subsequent use as delivery systems.     

陶寺、尉迟寺白灰面的测试研究

在XRD和拉曼光谱分析的基础上,借助XRF、ICP-AES和ICP-MS技术,对取自陶寺、尉迟寺遗址的“白灰面”做了相关测试和研究。结果表明,尉迟寺F85号红烧土房墙体表面白灰面为碳酸钙。陶寺“白灰面”有两种,一种为人工烧制的石灰,系石灰石烧制而成,表面打磨得较为光滑,并且有一块样品分4次加工,分为4层,表层主要为方解石和文石,里层则为石英含量略高的粘土和石灰的混合物,具较高的工艺,另外,有一块“白灰面”经检测为二水硫酸钙,这首次表明我国古代先民在4千年前已经开始开采和使用石膏做为建筑材料。     

One‐Pot Synthesis of Pentasubstituted Cyclohexanes by a Michael Addition Followed by a Tandem Inter–Intra Double Henry Reaction

Michael, Henry, and Henry : A new one‐pot reaction of α,β‐unsaturated aldehydes and β‐dicarbonyls, which involves a Michael reaction catalyzed by diarylprolinol ethers and an inter–intramolecular Henry tandem reaction catalyzed by TBAF (see scheme), has been developed. The reaction proceeds in high enantio‐ and diastereoselectivity for a wide range of unsaturated aldehydes and β‐dicarbonyl reagents.

     

单光子轨道角动量的传输特性研究

描述了高阶椭圆厄米-高斯光束及其单光子平均轨道角动量,并分析了一些与其单光子轨道角动量变化的有关情况,通过计算机仿真简要进行了说明.最后分析了单光子轨道角动量在空间某范围的概率分布及其变化情况.研究结果表明,高阶椭圆厄米-高斯光束与物质相互作用时,其单光子平均轨道角动量的变化幅度随接触物质材料的不同而异.     

J/psi production in quark-gluon plasma

We study J/psi production at RHIC and LHC energies with both initial production at energies reached and the BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC) with regeneration. We solve the coupled set of transport equations for the J/psi distribution in phase space and the hydrodynamic equation for evolution of quark-gluon plasma. At RHIC, continuous regeneration is crucial for the J/psi momentum distribution while the elliptic flow is still dominated by initial production. At energies reached at the LHC energy, almost all the initially created J/psis are dissociated in the medium and regeneration dominates the J/psi properties.     

Zinc and Copper Ions Induce Aggregation of Human β-Crystallins

Cataracts are defined as the clouding of the lens due to the formation of insoluble protein aggregates. Metal ions exposure has been recognized as a risk factor in the cataract formation process. The γ and β crystallins are members of a larger family and share several structural features. Several studies have shown that copper and zinc ions induce the formation of γ-crystallins aggregates. However, the interaction of metal ions with β-crystallins, some of the most abundant crystallins in the lens, has not been explored until now. Here, we evaluate the effect of Cu(II) and Zn(II) ions on the aggregation of HβA1, as a representative of the acidic form, and HβB2, as a representative of the basic β-crystallins. We used several biophysical techniques and computational methods to show that Cu(II) and Zn(II) induce aggregation following different pathways. Both metal ions destabilize the proteins and impact protein folding. Copper induced a small conformational change in HβA1, leading to high-molecular-weight light-scattering aggregates, while zinc is more aggressive towards HβB2 and induces a larger conformational change. Our work provides information on the mechanisms of metal-induced aggregation of β-crystallins.     

Activity coefficients of hexaamminecobalt(III) oxalate and hexacyanoferrate(III) in aqueous solutions of higher valent electrolytes at 25°C

The solubilities of hexaamminecobalt(III) oxalate and hexaamminecobalt(III) hexacyanoferrate(III) in aqueous solutions of different 1-2, 2-1 and 2-2 electrolytes were measured at 25°C. The results have been used to evaluate the relative activity coefficient of the saturating salts.     

Rhenium complexes with pyrazoles. Synthesis and crystal structure of trans-[Re(O)(OMe)L4]Br2·L·4H2O (L is 3,5-dimethylpyrazole)

The first mononuclear Re^V complex with four pyrazole ligands, viz., [Re(O)(OMe)L₄]Br₂ (L is 3,5-dimethylpyrazole), and its molecular adduct with L, viz., [Re(O)(OMe)L₄]Br₂·L·4H₂O, were synthesized. The complex is resistant to hydrolysis in a neutral aqueous solution. The structure of the adduct was established by X-ray diffraction analysis.