苯硼酸修饰的树形高分子作为高效的多肽胞内递送载体（英文）

小肽及其类似物在生命活动中发挥着至关重要的作用.开发高效、安全的小肽胞内递送技术对于生物医药以及生命科学基础研究都具有重要意义.当前,将不同性质的小肽高效递送到细胞中并使其发挥生物学功能仍然面临挑战.本文通过在树形高分子表面修饰苯硼酸基团得到一种小肽胞内递送载体.该载体可以将不同极性和带电性质的小肽高效、安全地递送到多种细胞系中.与传统的穿膜肽相比,该方法对小肽的递送效率更高,同时能够更加有效地保护小肽避免其被蛋白酶降解,维持其生物学活性.通过该研究,我们得到了一种高效、通用的小肽胞内递送方法,为小肽递送载体的理性设计提供了新的思路.     

An extracellular polymer at the interface of magnetic bioseparations

FucoPol, a fucose-containing extracellular polysaccharide (EPS) produced by bacterium Enterobacter A47 using glycerol as the carbon source, was employed as a coating material for magnetic particles (MPs), which were subsequently functionalized with an artificial ligand for the capture of antibodies. The performance of the modified MPs (MP–EPS-22/8) for antibody purification was investigated using direct magnetic separation alone or combined with an aqueous two-phase system (ATPS) composed of polyethylene glycol (PEG) and dextran. In direct magnetic capturing, and using pure protein solutions of human immunoglobulin G (hIgG) and bovine serum albumin (BSA), MP–EPS-22/8 bound 120 mg hIgG g⁻¹ MPs, whereas with BSA only 10 ± 2 mg BSA g⁻¹ MPs was achieved. The hybrid process combining both the ATPS and magnetic capturing leads to a good performance for partitioning of hIgG in the desired phase as well as recovery by the magnetic separator. The MPs were able to bind 145 mg of hIgG g⁻¹ of particles which is quite high when compared with direct magnetic separation. The theoretical maximum capacity was calculated to be 410 ± 15 mg hIgG adsorbed g⁻¹ MPs with a binding affinity constant of 4.3 × 10⁴ M⁻¹. In multiple extraction steps, the MPs bound 92% of loaded hIgG with a final purity level of 98.5%. The MPs could easily be regenerated, recycled and re-used for five cycles with only minor loss of capacity. FucoPol coating allowed both electrostatic and hydrophobic interactions with the antibody contributing to enhance the specificity for the targeted products.     

超导磁分离工业废水处理技术研究

超导高梯度磁分离污水处理是一种新型的污水处理技术.采用超导磁体和经过表面有机改性的铁磁性颗粒为"磁种"与污水中非磁性有害物质絮接,通过强磁场分离COD值降到78 ms/L,污水净化效果良好.讨论了利用等离子体聚合薄膜制备具有强捕捉能力的磁性粒子工艺.     

氨基酸磁性分子印迹微球的制备及吸附性能研究

采用分子印迹技术,以Ala和Phe为模板分子,苯乙烯和甲基丙烯酸为共聚单体,二乙烯苯为交联剂,Fe3O4为磁性载体,制备了对两种氨基酸有特异性识别的磁性分子印迹聚合物Ala-MMIPs和Phe-MMIPs。研究了两种印迹聚合物的吸附特性,并探讨了吸附机理。结果表明,Phe在其印迹聚合物上的最大吸附量和吸附平衡常数分别为231.62μmol/g和0.21L/mmol;而Ala在它的印迹微球上的最大吸附量和吸附平衡常数分别为179.16μmol/g和0.12L/mmol。说明Phe与Phe-MMIPs有3个作用位点,Ala与Ala-MMIPs之间有2个作用位点,因此吸附能力前者大于后者。     

Nanocrystalline materials for high temperature soft magnetic applications: A current prospectus

Conventional physical metallurgy approaches to improve soft ferromagnetic properties involve tailoring chemistry and optimizing microstructure. Alloy design involves consideration of induction and Curie temperatures. Significant in the tailoring of microstructure is the recognition that the coercivity, (H _c) is roughly inversely proportional to the grain size (D _g) for grain sizes exceeding ∼0·1−1 μm (where the grain size exceeds the Bloch wall thickness,δ). In such cases grain boundaries act as impediments to domain wall motion, and thus fine-grained materials are usually harder than large-grained materials. Significant recent development in the understanding of magnetic coercivity mechanisms have led to the realization that for very small grain sizesD _g<∼100 nm,H _c decreases sharply with decreasing grain size. This can be rationalized by the extension of random anisotropy models that were first suggested to explain the magnetic softness of transition-metal-based amorphous alloys. This important concept suggests that nanocrystalline and amorphous alloys have significant potential as soft magnetic materials. In this paper we have discussed routes to produce interesting nanocrystalline magnets. These include plasma (arc) production followed by compaction and primary crystallization of metallic glasses. A new class of nanocrystalline magnetic materials, HITPERM, having high permeabilities at high temperatures have also been discussed.     

电机槽楔用各向异性导磁复合材料进展

用各向异性导磁复合材料制备磁性槽楔是槽楔用导磁复合材料的发展趋势。本文综述了各向异性导磁复合材料的结构组成,并简要介绍了其相对于各向同性导磁复合材料所具备的特点,最后对目前各向异性导磁复合材料中存在的一些问题提出了看法和建议。     

Chemical interferences when using high gradient magnetic separation for phosphate removal: consequences for lake restoration

A promising method for lake restoration is the treatment of lake inlets through the specific adsorption of phosphate (P) on strongly magnetizable particles (Fe) and their subsequent removal using in-flow high gradient magnetic separation (HGMS) techniques. In this work, we report an extensive investigation on the chemical interferences affecting P removal efficiencies in natural waters from 20 Mediterranean ponds and reservoirs. A set of three treatments were considered based on different Fe particles/P concentration ratios. High P removal efficiencies (>80%) were found in freshwater lakes (conductivities < 600 μS cm⁻¹). However, a significant reduction in P removal was observed for extremely high mineralized waters. Correlation analysis showed that major cations (Mg²⁺, Na⁺ and K⁺) and anions (SO₄²⁻ and Cl⁻) played an essential role in P removal efficiency. Comparison between different treatments have shown that when increasing P and Fe concentrations at the same rate or when increasing Fe concentrations for a fixed P concentration, there exist systematic reductions in the slope of the regression lines relating P removal efficiency and the concentration of different chemical variables. These results evidence a general reduction in the chemical competition between P and other ions for adsorption sites on Fe particles. Additional analyses also revealed a reduction in water color, dissolved organic carbon (DOC) and reactive silicate (Si) concentrations with the addition of Fe microparticles.     

Nanoscale materials for tackling brain cancer: recent progress and outlook

This article reports on recent progress in the development of advanced nanoscale photoreactive, magnetic and multifunctional materials applicable to brain cancer diagnostics, imaging, and therapy, with an emphasis on the latest contributions and the novelty of the approach, along with the most promising emergent trends.     

制冷机用稀土磁性材料及其形状尺寸与加工

在概述了近年来制冷技术中应用较多的稀土磁性材料的基础上，介绍了这些材料在应用过程中形状与尺寸的确定思路和方法以及所采用的加工工艺。     

柠檬酸法合成纳米SrFe12O19的工艺分析及磁性研究

本文采用柠檬酸法制备出球形和棒状的纳米SrFe12O19颗粒,粒径为30～100 nm.并对其制备工艺进行研究,采用正交实验设计,主要考察了PH值、用水量、柠檬酸用量、煅烧时间、煅烧温度对粒子的粒径与性能的影响.利用TEM、XRD和IR等测试手段对样品进行表征,确定出制备分散均匀、粒径较小的纳米SrFe12O19的最佳工艺条件为柠檬酸与金属离子的摩尔比为1∶1,PH值为6,用水量为120ml,且在900℃下煅烧2h.并利用VSM对最佳工艺下的SrFe12O19的磁学性能进行研究,得出SrFe12O19的Hc为2456.3Oe,Ms为30.5 emu/g.     

两种磁性液体用氟碳表面活性剂性能的实验研究

氟碳表面活性剂作为一种新型功能材料,具有优良的耐热稳定性和化学稳定性,耐高温、耐酸碱、耐腐蚀等特性,具有高表面活性、用量少、有效率高等卓越特点,通过对2种氟碳表面活性剂：全氟聚醚油（FMY）和全氟聚醚酸（FMS）与其它碳氢类和有机硅类的表面活性剂在表面张力的测量,表面张力随温度的变化,复配张力变化以及粘温性能测试等几个方面进行实验,得出其最佳使用条件,从而为制备氟碳基磁性液体确定制备工艺条件。     

NiaSi2O5（OH）4 Multi-Walled Nanotubes with Tunable Magnetic Properties and Their Application as Anode Materials for Lithium Batteries

Highly crystalline and thermally stable pure multi-walled Ni₃Si₂O₅(OH)₄ nanotubes with a layered structure have been synthesized in water at a relatively low temperature of 200–210 °C using a facile and simple method. The nickel ions between the layers could be reduced in situ to form size-tunable Ni nanocrystals, which endowed these nanotubes with tunable magnetic properties. Additionally, when used as the anode material in a lithium ion battery, the layered structure of the Ni₃Si₂O₅(OH)₄ nanotubes provided favorable transport kinetics for lithium ions and the discharge capacity reached 226.7 mA·h·g⁻¹ after 21 cycles at a rate of 20 mA·g⁻¹. Furthermore, after the nanotubes were calcined (600 °C, 4 h) or reduced (180 °C, 10 h), the corresponding discharge capacities increased to 277.2 mA·h·g⁻¹ and 308.5 mA·h·g⁻¹, respectively.