Chitosan(Chitin)/Cellulose Composite Biosorbents Prepared Using Ionic Liquid for Heavy Metal Ions Adsorption

Chitosan(chitin)/cellulose composites as biodegradable biosorbents were prepared under an environment-friendly preparation processes using ionic liquids. Infrared and X-ray photoelectron spectra indicated the stronger intermolecular hydrogen bond between chitosan and cellulose, and the hydroxyl and amine groups were believed to be the metal ion binding sites. Among the prepared biosorbents, freeze-dried composite had higher adsorption capacity and better stability. The capacity of adsorption was found to be Cu(II) (0.417 mmol/g) > Zn(II) (0.303 mmol/g) > Cr(VI) (0.251 mmol/g) > Ni(II) (0.225 mmol/g) > Ph(II) (0.127 mmol/g) at the same initial concentration 5 mmol L-1. In contrast to some other chitosan-type biosorbents, preparation and component of the biosorbent were obviously more environment friendly. Moreover, adsorption capacity of chitosan in the blending biosorbent could be fully shown.

A general route to prepare one- and three-dimensional carbon nanotube/metal nanoparticle composite nanostructures

Adsorption of polyethyleneimine (PEI)-metal ion complexes onto the surfaces of carbon nanotubes (CNTs) and subsequent reduction of the metal ion leads to the fabrication of one-dimensional CNT/metal nanoparticle (CNT/M NP) heterogeneous nanostructures. Alternating adsorption of PEI-metal ion complexes and CNTs on substrates results in the formation of multilayered CNT films. After exposing the films to NaBH4, three-dimensional CNT composite films embedded with metal nanoparticles (NPs) are obtained. UV-visible spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy are used to characterize the film assembly. The resulting (CNT/M NP)(n) films inherit the properties from both the metal NPs and CNTs that exhibit unique performance in surface-enhanced Raman scattering (SERS) and electrocatalytic activities to the reduction of O-2; as a result, they are more attractive compared to (CNT/polyelectrolyte)(n) and (NP/polyelectrolyte)(n) films because of their multifunctionality.

Synthesis of the first rare earth metal bis(alkyl)s bearing an indenyl functionalized N-heterocyclic carbene

Treatment of indenyl-modified imidazolium bromide [C9H7CH2CH2(NCHCHN(C6H2Me3-2,4,6)CH)Br] ((IndH-NHC-H)Br) with rare earth metal tetra(alkyl) lithium (Ln(CH2SiMe3)(4)Li(THF)(4)) or with (trimethylsilylmethyl)lithium (LiCH2SiMe3) and rare earth metal tris(alkyl)s (Ln(CH2SiMe3)(3)(THF)(2)) sequentially afforded the first NHC-stabilized monomeric rare earth metal bis(alkyl) complexes (Ind-NHC)Ln(CH2SiMe3)(2) (1, Ln = Y; 2, Ln = Lu; 3, Ln = Sc) via double-deprotonation reactions. Complexes 1-3 are THF-free isostructural monomers. The monoanionic Ind-NHC species bond to the central metal ion in a eta(5):kappa(1) constrained geometry configuration (CGC) mode, which combine with the two cis-located alkyl moieties to form a tetrahedron ligand core, leading to the chirality of the complexes. Under the presence of activators AlEt3 and [Ph3C][B(C6F5)(4)], complex 2 showed catalytic activity toward the polymerization of isoprene to afford 3,4-regulated polyisoprene (91%).

Solvent effects of a fluorescent polyquinoline chemosensor for metal ions

Red shift and quenching effects of the fluorecence spectra of polyquinoline (PQH) solutions in different solvents are observed upon the addition of metal ions, which demonstrates the extraordinary solvent effects on metal-ion recognition and sensing ability (including sensitivity and selectivity) of PQH.

Preparation and characterization of PSt-b-PHEMA metal hybrids

The block copolymer polystyrene-b-poly[2-(trimethylsilyloxy)ethylene methacrylate] (PSt-b-PTMSEMA) was synthesized using atom-transfer radical polymerization (ATRP). The hydrolysis of PSt-b-PTMSEMA led to the formation of an amphiphilic block copolymer, polystyrene-b-poly(2-hydroxylethyl methacrylate) (PSt-b-PHEMA), which was characterized by GPC and H-1-NMR. TEM showed that the PSt-b-PHEMA formed a micelle, which is PSt as the core and PHEMA as the shell. Under appropriate conditions, the nickel or cobalt ion cause chemical reactions in these micelles and could be reduced easily. ESCA analysis showed that before reduction the metal existed as a hydroxide; after reduction, the metal existed as an oxide, and the metal content of these materials on the surface is more than that on the surface of the copolymer metal ion. XRD analysis showed that the metal existed as a hydroxide before reduction and existed as a metal after reduction.

Investigation of ion transfer across the micro-water/nitrobenzene interface facilitated by a fullerene derivative

A functionalized fullerene derivative containing a monoaza-18-crown-6 moiety was investigated by facilitated ion (such as Li+, Na+, K+, NH4+, Mg2+, and Ca2+) transfer across the micro-water/nitrobenzene interface supported at the tip of a micropipet. The current responses were detected by cyclic voltammetry and Osteryoung square wave voltammetry, which demonstrated that the facilitated ion transfer does occur by an interfacial complexation-dissociation process. The diffusion coefficient of this compound in nitrobenzene was approximately (5.90 +/- 0.04) x 10(-7) cm(2) s(-1), which is 1 order of magnitude less than other common ionophores due to the large size of the molecule. The selectivity of this molecule toward the metal ions followed the sequence Na+ > Li+ > K+ > NH4+ > Ca2+ similar to Mg2+. In addition, this compound was also easy to form film at the water/nitrobenzene interface to inhibit the simple ion transfer of tetramethylammonium ion. However, the adsorption of this ionophore has less influence on the facilitated metal ion transfer.

Gaseous dipeptide complexes with metal ions by electrospray ionization and tandem mass spectrometry

Electrospray ionization (ESI) and tandem mass spectrometry have been used to investigate the gas-phase interactions of five metal ions and seven dipeptides. For silver ion, two complexes ([M+Ag](+) and [2M+Ag](+)) were obtained as well as the one complex ([2M+Met-H](+)) for transition-metal ions. Upon collision activation, there is an obvious difference in MS/MS data between metal ion complex and the protonated molecule. The fragment pathway of each complex is related to the structures of dipeptide and the nature of metal ion which suggest that there are several interaction between the metal ions and dipeptides in gas phase.

QM/MM and Classical Molecular Dynamics Simulation of Histidine-Tagged Peptide Immobilization on Nickel Surface

The hybrid quantum mechanics (QM) and molecular mechanics (MM) method is employed to simulate the His-tagged peptide adsorption to ionized region of nickel surface. Based on the previous experiments, the peptide interaction with one Ni ion is considered. In the QM/MM calculation, the imidazoles on the side chain of the peptide and the metal ion with several neighboring water molecules are treated as QM part calculated by “GAMESS”, and the rest atoms are treated as MM part calculated by “TINKER”. The integrated molecular orbital/molecular mechanics (IMOMM) method is used to deal with theQMpart with the transitional metal. By using the QM/MM method, we optimize the structure of the synthetic peptide chelating with a Ni ion. Different chelate structures are considered. The geometry parameters of the QM subsystem we obtained by QM/MM calculation are consistent with the available experimental results. We also perform a classical molecular dynamics (MD) simulation with the experimental parameters for the synthetic peptide adsorption on a neutral Ni(1 0 0) surface. We find that half of the His-tags are almost parallel with the substrate, which enhance the binding strength. Peeling of the peptide from the Ni substrate is simulated in the aqueous solvent and in vacuum, respectively. The critical peeling forces in the two environments are obtained. The results show that the imidazole rings are attached to the substrate more tightly than other bases in this peptide.

QM/MM and Classical Molecular Dynamics Simulation of Histidine-Tagged Peptide Immobilization on Nickel Surface

The hybrid quantum mechanics (QM) and molecular mechanics (MM) method is employed to simulate the His-tagged peptide adsorption to ionized region of nickel surface. Based on the previous experiments, the peptide interaction with one Ni ion is considered. In the QM/MM calculation, the imidazoles on the side chain of the peptide and the metal ion with several neighboring water molecules are treated as QM part calculated by "GAMESS", and the rest atoms are treated as MM part calculated by "TINKER". The integrated molecular orbital/molecular mechanics (IMOMM) method is used to deal with the QM part with the transitional metal. By using the QM/MM method, we optimize the structure of the synthetic peptide chelating with a Ni ion. Different chelate structures are considered. The geometry parameters of the QM subsystem we obtained by QM/MM calculation are consistent with the available experimental results. We also perform a classical molecular dynamics (MD) simulation with the experimental parameters for the synthetic peptide adsorption on a neutral Ni(100) surface. We find that half of the His-tags are almost parallel with the substrate, which enhance the binding strength. Peeling of the peptide from the Ni substrate is simulated in the aqueous solvent and in vacuum, respectively. The critical peeling forces in the two environments are obtained. The results show that the in-tidazole rings are attached to the substrate more tightly than other bases in this peptide.

绞股蓝离体培养中影响皂甙产量的几个因素研究

绞股蓝(Gynostemma pentaphyllum)系葫芦科绞股蓝属植物，药用价值广泛，但其野生资源日趋减少，绞股蓝主要药效成分为绞股 蓝皂甙。利用组织和细胞培养生产绞股蓝皂甙是合理开发利用和保护绞股蓝资源的可能途径之一。本文对绞股蓝组织培养中培养基 的蔗糖和激素的组成以及各种胁迫条件：渗透压、重金属离子、真菌诱导物等对皂苷产量的影响进行了初步研究。其中，渗透压、 重金属离子、真菌诱导物对绞股蓝愈伤组织皂甙产量的影响尚未见报道。1. 蔗糖对绞股蓝愈伤组织之生长影响显著，2,4-D对绞股 蓝愈伤组织皂甙含量、产量影响显著。增加蔗糖用量，减少2，4-D的用量可提高皂甙产量。2. Mn++ 用量的提高抑制绞股蓝愈伤组 织的生长，但可促进皂甙含量、产量的提高。Mn++用量提高至MS培养基的20-30倍时可使皂甙产量增加近一倍，而提高Cu++浓度的 作用不明显。3. 甘露醇用量增加抑制绞股蓝愈伤组织的生长，但可使皂甙含量、产量提高。0.680mol·l-1甘露醇可使皂甙产量提 高83%，而Nacl较大抑制愈伤组织的生长并使皂甙产量降低。4. 米曲霉粗提物对绞股蓝愈伤组织生长先略微促进，然后抑制，而根 霉粗提物则使愈伤组织生长受抑制；两者对皂甙含量、产量的作用相似：在较低浓度范围内升高，然后下降。米曲霉粗提物可提高 产量一倍，根霉粗提物可提高42%。这些结果为高产细胞系的筛选和生长、生产培养条件的优化积累了资料。在综述部分，对植物 细胞培养中组织和器官分化、细胞结构变化、生化水平的变化与次生物合成和积累的关系作了讨论。Gynostemma pentaphyllum blongs to Gynostemma, Cucurbitaccae. It has a wide medical use, but its wild resource is threatened by people's excessive use. Its effective medical components are gypenosides. For reasonable use and protect its resource, it is a possible way to product gypenosides by plant tissue and cell culture. This paper has a primary study on the components of sucrose and hormones and a variety of stress conditions: osmostic pressure, heavy metal ion, fungal elicitors in the medium for the calli culture. The effects of osmostic pressure, heavy metal ion and fungal elicitors on the calli of Gynostemma pentaphyllum have not been reported. 1. Sucrose had a significant effect on the growth of the calli, 2,4 D had notable effects on the gypenosides content and production of the calli. Increased the concentration of sucrose and decreased the concentration of 2,4 D improved the production of gypenosides. 2. Increased the concentration of Mn++ inhibited the growth of the calli, but improved the content and production of gypenosides. The optimum concentration was 20-30 times as MS medium which improved the production 100%. Increased the concentration of Cu++ had not a notable effect. 3. Increased the concentration of mannitol inhibited the growth of the calli, but improved the content and production of gypenosides. The optimum concentration was 0.680mol·l-1 which improved the production 83%. Nacl apparently inhibited the growth of the calli and decreased the production of gypenosides. 4. The crude preparation of Aspergillus oryzae inhibited the growth of the calli that in low concentration. The crude praparation of Rhizopus formosensis inhibited the growth of the calli throughout. Their effects on the content and production of gypenosides are alike, but the former is higher than the latter. On the optimum concentration, each crude preparation improved the production 100% (Aspergillus oryzae), 42%(Rhizopus formosensis). These results has accumulated some informantion on the select of high yield cell strains and choose the best culture conditons for the growth and gypenosides product of the calli. In the review, it is discussed that the differentiation on tissue-organal, cellular and biochemical levels related to the synthesis and accumulation of secondary metabolites in plant culuture.

全永磁ECR离子源研究进展

Electron Cyclotron Resonance (ECR) ion source is regarded as the most efficient machine to produce stable multiple charge state ion beams. Because of the special characteristics, all-permanent magnet ECR ion sources have been widely adopted around the world to produce stable ion beams of multiple charge state with good repetition have been widely adopted around the world to produce stable ion beams of multiple charge state with good repetition and high duty factor for compact research platforms and ion beam implanters. In this paper, all-permanent magnet ECR ion sources developed at IMP are presented, and typical parameters and performances are discussed. The high charge state source, LAPECR2, is mainly used to produce intense high charge state ion beams, and the LAPECR1 source is designed to produce intense ion beams of medium and low charge state. An improved LAPECR1-M is specially designed to produce heavy metal ion beams of low charge state. These ECR ion sources have been adopted by different experimental terminals at IMP and, with their nice performance, many experimental studies could be possible. 中文文摘：ECR(电子回旋共振)离子源是产生稳定的强流多电荷态离子束流最有效装置。全永磁ECR 离子源因其独特的特点为很多中小型多电荷态离子束流实验平台与离子注入机等系统所采用，为后者产生重复性好、稳定性强的多电荷态离子束流。本文着重论述了中国科学院近代物理研究所研制的几台全永磁多电荷态ECR 离子源及其特性与典型性能，如能产生强流高电荷态离子束流的高性能全永磁离子源LAPECR2，能产生强流中 低电荷态离子束流的LAPECR1，能产生多电荷态重金属离子束流的LAPECR1-M 等。这些性能稳定的离子源为提高近代物理研究所相关试验平台的性能提供了关键的束流品质保障。

Flow-through room temperature phosphorescence optosensing for the determination of lead in sea water

The chelates formed between the heavy metal ion Pb(II) and the reagents 8-hydroxy-5-quinolinesulphonic acid, 8-hydroxy-7-quinolinesulphonic acid and 8-hydroxy-7-iodo-5-quinolinesulphonic acid exhibit strong room temperature phosphorescence (RTP) if retained on the surface of anion exchange resin beads. Based on the on-line formation, in a flow-injection system, of such RTP lead chelates and their transient immobilization on an anion exchange resin, three flow-through optosensing systems are investigated for lead in sea water. Optimum experimental conditions and the analytical performance characteristics of the three optosensors are discussed. Relative standard deviations (RSDs) of the order of 3% are typical at 100 ng ml−1 Pb(II) and the active sensing phases can easily be regenerated by passing 500 μl of 6 M hydrochloric acid. A lead(II) detection limit of 0.1 ng ml−1 (3×background SD, for 2 ml sample injection volumes) was achieved for the optosensor based on 8-hydroxy-7-quinolinesulphonic acid. Possible interferences present in sea water, including cations and anions which could affect the sensor response, are discussed in detail. Finally, the selected RTP flow-through optical sensor has been successfully tested for the determination of lead in sea water at a few ng ml−1.

Assembly of the highest connectivity Wells-Dawson polyoxometalate coordination polymer: the use of organic ligand flexibility

Through tuning the length of flexible bis(triazole) ligands and different metal ion coordination geometries, four Wells-Dawson polyoxoanion-based hybrid compounds, [Cu-6(btp)(3)(P2W18O62)] center dot 3H(2)O (1) (btp = 1,3-bis(1,2,4-triazol-1-yl)propane), [Cu-6(btb)(3)((P2W18O62) center dot 2H(2)O (2), [Cu-3(btb)(6)(P2W18O62)] center dot 6H(2)O (btb = 1,4-bis(1,2,4-triazol-1-yl)butane) (3), and [Cu-3(btx)(5.5)((P2W18O62) center dot 4H(2)O (btx = 1,6-bis(1,2,4-triazol-1-yl)hexane) (4), were synthesized and structurally characterized. in compound 1, the metal-organic motif exhibits a ladder-like chain, which is further fused by the ennead-dentate [P2W18O62](6-) anions to construct a 3D structure. In compound 2, the metal-organic motif exhibits an interesting Cu-btb grid layer, and the ennead-dentate polyoxoanions are sandwiched by two Cu-btb layers to construct a 3D structure

Assembly of supramolecular compounds with water-soluble calix[4]arenes

Three new copper compounds, Cu-2[C12H8N2](2)[C28H2OS4O16][H2O](11.9) (1), Cu-2[C12H8N2](3)[C28H20S4O16][H2O](5) (2), and Cu-2[C12H8N2](4)[C24H12S8O16][H2O](10.5) (3), were hydrothermally synthesized and structurally determined by X-ray diffraction and TG-DTA analyses. Interestingly, Compounds 1 and 2 were synthesized in a one-pot reaction. Complexes 1 and 3 contain capsule units, which are further assembled into three-dimensional (3-D) architectures with a-Po-related topology by pi-pi stacking and/or hydrogen-bonding interactions.