利用碳酸乙烯酯开环产物合成聚氨酯脲弹性体

二氧化碳的综合利用是关系人类生存环境的重大课题。采用二氧化碳的衍生物碳酸乙烯酯和1.6-己二胺开环反应合成脂肪族氨酯二醇,并将开环产物作为扩链剂与脂肪族聚碳酸酯二醇(PCDL)和异佛尔酮二异氰酸酯(IPDI)反应合成了脂肪族聚碳酸酯聚氨酯脲弹性体。研究表明,开环反应在38℃,反应10h后,可得到产率为89.9%(质量分数)的产物1.6-二(2-羟基-乙氧基羰基胺)已烷(DHDU)。通过改变碳酸乙烯酯开环物(DHDU)在大分子链中形成的氨酯-脲硬段单元的比例,可以调节合成的聚氨酯脲弹性体的机械性能。当脂肪族聚碳酸酯二醇(PCDL)分子量相同时,随着PCDL/DHDU摩尔比的减小,合成的聚氨酯脲弹性体的拉伸强度和硬度增加,断裂伸长率减小。该合成产物在生物材料领域具有广泛的应用前景。     

自蔓延法制取锰铝中间合金的实验

首次将自蔓延高温合成法（self-propagating high-temperature synthesis,SHS）用于锰铝中间合金的制备。采用Miedema生成热模型、金属间化合物的双参数模型估算了锰铝中间合金的标准生成焓、标准熵及比热容。通过理论计算确定了Mn3O4-Mn2O3-CaO-Al反应体系的绝热温度。以Mn2O3、Mn3O4和CaO、金属Al为原料,进行了锰铝中间合金的自蔓延反应合成试验,采用化学滴定、X射线衍射以及光学显微镜的方法对产物进行分析。理论计算和实验结果表明：反应体系的绝热温度为3 160 K,确定了该体系进行自蔓延反应的可行性。采用自蔓延合成法制备出了锰含量高达78%以上的锰铝中间合金,拓宽了锰铝中间合金的生产工艺。     

高校图书馆社区服务刍议

分析了高校图书馆服务社区的价值和可行性,探讨了高校图书馆社区服务的具体流程,包括居民用户需求调查、组织资源和人员、评价服务效果、加强管理等。     

浅谈基层图书馆的回溯建库——以阳泉市图书馆为例

阐述了图书馆回溯建库工作的意义,以阳泉市图书馆为例,介绍了回溯建库的前期准备工作,探讨了回溯建库工作的具体实施过程和有关做法。     

Electrochemical sensor for naphthols based on gold nanoparticles/hollow nitrogen-doped carbon microsphere hybrids functionalized with SH-β-cyclodextrin

Due to awfully harmful to the environment and human health, the qualitative and quantitative determinations of naphthols [1-naphthol (1-NAP) and 2-naphthol (2-NAP)] are of great significance and receive great attention. In this paper, gold nanoparticles (AuNPs)/hollow nitrogen-doped carbon microspheres (HNCMS) hybrids (AuNPs/HNCMS) were prepared and functionalized with thiolated-β-cyclodextrin (HS-β-CD) for the first time, and then applied successfully in sensitive and simultaneous electrochemical detection of naphthols. The results show that the oxidation peak currents of naphthols obtained on the HS-β-CD/AuNPs/HNCMS modified glassy carbon (GC) electrode are much higher than that on the AuNPs/HNCMS/GC, HNCMS/GC and bare GC electrodes. Additionally, compared with other electrochemical sensors developed previously, the proposed electrode results in improved detection limits of about four times for 1-NAP (1.0 nM) and two orders of magnitude for 2-NAP (1.2 nM). The linear response ranges of both 1-NAP and 2-NAP are 2–150 nM.     

The golden age: gold nanoparticles for biomedicine

Gold nanoparticles have been used in biomedical applications since their first colloidal syntheses more than three centuries ago. However, over the past two decades, their beautiful colors and unique electronic properties have also attracted tremendous attention due to their historical applications in art and ancient medicine and current applications in enhanced optoelectronics and photovoltaics. In spite of their modest alchemical beginnings, gold nanoparticles exhibit physical properties that are truly different from both small molecules and bulk materials, as well as from other nanoscale particles. Their unique combination of properties is just beginning to be fully realized in range of medical diagnostic and therapeutic applications. This critical review will provide insights into the design, synthesis, functionalization, and applications of these artificial molecules in biomedicine and discuss their tailored interactions with biological systems to achieve improved patient health. Further, we provide a survey of the rapidly expanding body of literature on this topic and argue that gold nanotechnology-enabled biomedicine is not simply an act of 'gilding the (nanomedicinal) lily', but that a new 'Golden Age' of biomedical nanotechnology is truly upon us. Moving forward, the most challenging nanoscience ahead of us will be to find new chemical and physical methods of functionalizing gold nanoparticles with compounds that can promote efficient binding, clearance, and biocompatibility and to assess their safety to other biological systems and their long-term term effects on human health and reproduction (472 references).     

Functionalization of magnetic nanoparticles with dendritic-linear-brush-like triblock copolymers and their drug release properties

Novel water-soluble dendritic-linear-brush-like triblock copolymer polyamidoamine-b-poly(2-(dimethylamino)ethyl methacrylate)-b-poly(poly(ethylene glycol) methyl ether methacrylate) (PAMAM-b-PDMAEMA-b-PPEGMA)-grafted superparamagnetic iron oxide nanoparticles (SPIONs) were successfully prepared via a two-step copper-mediated atom transfer radical polymerization (ATRP) method. The macroinitiators were immobilized on the surface of Fe(3)O(4) nanoparticles via effective ligand exchange of oleic acid with the propargyl focal point PAMAM-typed dendron (generation 2.0, denoted as propargyl-D(2.0)) containing four carboxyl acid end groups, following a click reaction with 2'-azidoethyl-2-bromoisobutylate (AEBIB). PDMAEMA and PPEGMA were grown gradually from nanoparticle surfaces using the "grafting from" approach, which rendered the SPIONs soluble in water and reversed aggregation. To the best of our knowledge, this is the first report that describes the functionalization of magnetic nanoparticles with dendritic-linear-brush-like triblock copolymers. The modified nanoparticles were systematically studied via TEM, FT-IR, DLS, XRD, NMR, TGA, and magnetization measurements. DLS measurement confirmed that the obtained dendritic-linear-brush-like triblock copolymer-grafted SPIONs had a uniform hydrodynamic particle size of average diameter less than 30 nm. The dendritic-linear-brush-like triblock copolymer-grafted SPIONs possessed excellent biocompatibility by methyl tetrazolium (MTT) assays against NIH3T3 cells and hemolysis assays with rabbit erythrocytes. Furthermore, an anticancer drug, doxorubicin (Dox), was used as a model drug and loaded into the dendritic-linear-brush-like triblock copolymer-grafted SPIONs, and subsequently, the drug releases were performed in phosphoric acid buffer solution pH = 4.7, 7.4, or 11.0 at 37 °C. The results verify that the dendritic-linear-brush-like triblock copolymer-grafted SPIONs possess pH-responsive drug release behavior. The Dox dose of the loaded and free drug required for 50% cellular growth inhibition was 2.72 and 0.72 μm/mL, respectively, according to MTT assay against a Hella cell line in vitro. Therefore, on the basis of its biocompatibility and drug release effect, the modified SPION could provide a charming opportunity to design some excellent drug delivery systems for therapeutic applications.     

Efficient Curing of Vinyl Carbonates by Thiol‐Ene Polymerization

Vinyl carbonates have recently been identified as a suitable alternative to (meth)acrylates, especially due to the low irritancy and cytotoxicity of these monomers. The drawback of some vinyl carbonates containing abstractable hydrogens arises through their moderate reactivity compared with acrylates. Within this paper, we use the thiol‐ene concept to enhance the photoreactivity of vinyl carbonates to a large extent to reach the level of those of similar acrylates. Mechanical properties of the final thiol‐ene polymers were determined by nanoindentation. Furthermore, low toxicity of all components was confirmed by osteoblast cell culture experiments.     

Molecular designing and DFT investigation of novel alternating donor–acceptor dibenzo[b,d]thiophen-based systems: from monomer to polymer

The structures and properties of dibenzo[b,d]thiophene (DBT) based alternating donor–acceptor conjugated oligomers, in which thieno[3,4-b]pyrazine (TP), thieno[3,4-b]thiadiazole (TD), and [1,2,5]thiadiazolo[3,4-e]thieno[3,4-b]pyrazine (TTP) as acceptors, and their periodic polymers were investigated by the density function theory (DFT) at the B3LYP/6-31G(d) level. The bond length, electron density at bond critical points (BCPs) and nucleus-independent chemical shift (NICS) are analyzed and correlated with the conductive properties. NICS shows that the conjugation degree is increased with main chain extension. Research results show the conductive ability of compounds with 1:2 D–A ratio is better than that with 1:1 D–A ratio. The reorganization energies and energy bands also are considered. The results suggest that (BTDDBT) _n and (BTPDDBT) _n have small reorganization energy (0.163 and 0.152 eV, respectively) and quite low energy gap (0.73 and 0.56 eV, respectively), which indicate that they may be potential organic conductive materials.     

全冠义齿碰撞检测算法研究与应用

全冠义齿数字化设计中,针对变形牙冠与非变形牙冠碰撞检测问题,提出一种基于动态混合包围盒的碰撞检测算法。首先,在预处理阶段为非变形牙冠建立,包含AABB和OBB包围盒的混合包围盒。设计过程中查询变形模型处于非变形模型AABB包围盒内的数据,为其建立局部动态AABB包围盒,将它与非变形模型的OBB包围盒进行碰撞检测,返回干涉图元的交线。之后,查询干涉区域并计算刺穿深度,将结果以色阶图的形式返回。碰撞检测效率高,可达到实时响应,色阶图结果清晰直观,为牙冠设计提供明确的操作依据。