Metallo-supramolecular complexes from mPEG/PDPA diblock copolymers and their self-assembled strip nanosheets

Herein we designed and synthesized mPEG/PDPA copolymers containing two 4-([2,2′:6′,2′′-terpyridin]-4′-yl) phenyl (Tpyp) groups at the junction point of the two blocks (mPEG(-b-Tpyp)₂-b-PDPA_x, x = 23, 33, and 44). Interestingly, after a hierarchical pattern from the coordination of mPEG(-b-Tpyp)₂-b-PDPA_x with Ru(ii) ions followed by the self-assembly in water, 2D strip nanosheets with a monomolecular layer were obtained. In contrast, mPEG(-b-Tpyp)₂-b-PDPA_x without coordination self-assembled into spherical micelles in the similar condition. The formation of the rigid and charged ⋯Tpyp-Ru(ii)⋯ chain, the brush-shaped polymer architecture and the presence of the hexafluorophosphate (PF₆⁻) counterions should be responsible for the unique self-assembly behavior of the metallo-supramolecular complexes. It is expected that the hierarchical self-assembly pattern can provide a new strategy for preparation of self-assemblies with different morphologies.

Copolymers mPEG(-b-Tpyp)₂-b-PDPA_x were synthesized. After a hierarchical pattern from the coordination of the copolymers with Ru(ii) ions followed by the self-assembly in water, 2D strip nanosheets were obtained.     

High-temperature resistant water-soluble polymers derived from exotic amino acids

High-performance water-soluble polymers have a wide range of applications from engineering materials to biomedical plastics. However, existing materials are either natural polymers that lack high thermostability or rigid synthetic polymers. Therefore, we design an amino acid-derived building block, 4,4′-diamino-α-truxillate dianion (4ATA²⁻), that induces water solubility in high-performance polymers. Polyimides containing 4ATA²⁻ units are intrinsically water-soluble and are processed into films cast from an aqueous solution. The resulting polyimide films exhibit exceptional transparency and extremely high thermal stability. In addition, the films can be made insoluble in water by simple post-treatment using weak acid or multivalent metal ions such as calcium. The synthesized polyimide''s derived from bio-based resources are useful for yielding waterborne polymeric high-performance applications.

High-performance water-soluble polymers have a wide range of applications from engineering materials to biomedical plastics. This article discusses the synthesis of water-soluble polyimide from bio-based monomers.     

A novel off-on fluorescent chemosensor for Al3+ derived from a 4,5-diazafluorene Schiff base derivative

The performance of a chemosensor is closely related to its structure. A new Schiff bass (DFSB) based on 4,5-diazafluorene units has been synthesized in this work. The interaction of DFSB with different metal ions has been studied using UV-vis absorption spectra and fluorescent spectra. The results show that DFSB is a highly selective and sensitive probe for Al³⁺ ions over other commonly coexisting metal ions in ethanol. A very obvious fluorescence enhancement effect was observed, and a turn-on ratio over 1312-fold was triggered with the addition of 10 equiv. of Al³⁺ ions. What is more, such fluorescent responses could be detected by the naked eye under a UV-lamp. The lowest detection limit for Al³⁺ was determined as 3.7 × 10⁻⁸ M. The complex solution (DFSB–Al³⁺) exhibited reversibility with EDTA. These results may be caused by the unique molecular structure.

A highly selective and sensitive“turn-on” fluorescent sensor for detecting Al³⁺ derivated from 4,5-diazafluorene.     

Anti-HSV-1 activity of synthetic humic acid-like polymers derived from p-diphenolic starting compounds

A panel of ten humic-acid-like polymers was synthesized by oxidation of p-diphenolic compounds and characterized by relative molecular weights, FT-IR spectra and functional group analysis. Using the XTT-based tetrazolium reduction assay EZ4U, both the low-molecular starting compounds and the synthesized polymers were examined for antiviral and cytotoxic activities in HSV-1-infected Vero cells. With the exception of hydroquinone, 2,5-dihydroxytoluene and 2,5-dihydroxybenzoquinone, the starting compounds failed to inhibit herpesvirus replication. The polymeric oxidation products, however, developed anti-HSV-1 activity with EC50 values in the range of 0.65 (2,5-DHPOP) and 322 microg/ml (2,5-DHBQOP). The CC50 values of the polymers varied among 32.0 (TMHYDROP) and >512 microg/ml (2,5-DHBQOP, HYDSULFOP). The most effective polymers were found to be 2,5-DHPOP 2,5-DHTOP and GENOP (EC50: 0.65, 1.6 and 2.2 microg/ml, respectively, and SI: > or = 400, > or = 80 and > or = 58, respectively). Functional group analysis revealed that increasing numbers of carboxyl groups together with a high content of hydroxyl groups tend to enhance the antiviral activity of polymers derived from p-diphenolic compounds.     

护理安全评分表用于高龄住院患者安全预防的研究

目的 寻找有利于高龄住院患者安全预防的最佳方法 .方法 选取2006年1-8月收治的296例高龄住院患者和2007年1-8月收治的336例高龄住院患者,分别作为对照组和改进组,改进组采用护理安全评分表进行"危机程度"评分,实施针对性的安全防范措施;对照组使用常规的安全护理措施,2组患者分别在住院时间、发生不安全事件的人数等方面进行对比.结果 2组患者分别在住院时间、发生不安全事件的人数、家属满意度、护理2组患者护士的交接班时间、护士满意度,进行对比,差异均有统计学意义.结论 高龄患者在人院当日使用"护理安全评分表"进行"危机程度"评估,确定其危险指数,并实施针对性的安全护理防范措施,可明显降低高龄住院患者不安全事件的发生并减少住院时间,同时能缩短护士交接班时间,提高交接班效率.实现护患双赢.     

Surfactant-free synthesis of fluorescent platinum nanoclusters using HEPES buffer for hypochlorous acid sensing and imaging

A surfactant-free synthesis of noble-metal nanoclusters (NMNCs) with specific function has recently remained more attractive and superior in bio-applications. Herein, by employing the weak reducibility of non-toxic HEPES, we prepared novel water-soluble fluorescent HEPES@Pt NCs by a simple surfactant-free synthesis strategy for hypochlorous acid (HClO) sensing. The as-prepared Pt NCs featured ultra-small size (∼2 nm), bright blue fluorescence, high stability and biocompatibility, and the fluorescence of the Pt NC nanoprobe can be specifically quenched with hypochlorous acid by a static quenching process. Moreover, the surfactant-free Pt NC probe displays fascinating performances for HClO sensing, including fast response to HClO, high stability and specificity, and is further applied for imaging the fluctuations of the HClO concentration in living cells with satisfactory results for the first time. Thereby, we anticipate that it is a reliable and attractive approach to develop versatile NMNCs through the surfactant-free synthesis for further applications in biological research.

In this study, by employing the weak reducibility of non-toxic HEPES, a novel water-soluble fluorescent HEPES@Pt NC was successfully prepared by a simple surfactant-free synthesis strategy for ClO⁻ sensing and imaging.     

Atomic absorption spectrophotometry of free circulating platinum species in plasma derived from cis-dichlorodiammineplatinum(II)

We describe a method of analysis for free circulating platinum species derived from cis-dichlorodiammineplatinum(II) in blood plasma. Protein-bound and free platinum species were separated from each other by centrifugal ultrafiltration. Platinum in the ultrafiltrate was converted to a cationic complex by reaction with ethylenediamine, and the product was collected on paper impregnated with cation-exchange resin, where it could be stored indefinitely without loss. The platinum was eluted from the disk with 5 mol/liter hydrochloric acid, and an aliquot of this solution was then analyzed by flameless atomic absorption spectrophotometry. The overall analytical recovery of platinum was 80 +/- 2%. The minimum quantity of cis-dichlorodiammineplatinum detectable was 35 microgram/liter of plasma at the 99% confidence level. Detector response was linearly related to drug concentration in the range from 80 microgram to 290 mg of Pt per liter of plasma. Reaction variables were made optimal, so as to yield maximum sensitivity and reproducibility (+/- 2%) consistent with minimal sample transfers and manipulations.     

A new human trophoblast antigen isolated from immune complexes derived from placental blood and membranes

Immune complexes were prepared from human trophoblast membranes, placental blood serum, non-pregnant female serum and normal male serum by precipitation, gel filtration and affinity chromatography. The purified complexes were subjected to analysis by SDS-PAGE and one common antigenic species was identified. This antigen (mol. wt. 82.8 +/- 2.4 K) was designated the putative trophoblast antigen (TA) and shown to exhibit discrete antigenic homology with human immunoglobulin and HLA molecules.     

New dinuclear zinc(ii) complexes with Schiff bases obtained from o-phenylenediamine and their application as fluorescent materials in spin coating deposition

Two Zn(ii) complexes, K1 and K2, obtained from the template reaction of zinc(ii) acetate dihydrate with o-phenylenediamine and 2-hydroxy-5-methylisophthalaldehyde (K1) or 2-hydroxy-5-tert-butyl-1,3-benzenedicarboxaldehyde (K2), respectively, were characterized by X-ray crystallography, spectroscopic (UV-vis, fluorescence and IR), and thermal methods. In the complex [Zn₂(MeO)_1.4(OH)_0.6(L1)]·2H₂O K1, there are two binding sites in the macrocyclic ligand and they are occupied by zinc(ii) cations found in slightly distorted square pyramidal environment. The zinc(ii) cations are connected by slightly asymmetric oxo bridges with a Zn1–O14–Zn1[−x, −y + 1, −z + 1] angle of 104.8(2)°. In the dimer [Zn₂(CH₃COO)₂(L2)]·2EtOH K2, there are two crystallographically independent binding sites both occupied by zinc(ii) cations. There is a significant difference between both complexes, since in K1 only one site is independent and the second is occupied due to the application of symmetry rules, and the geometry of both sites is identical. Thin layers of the obtained Zn(ii) complexes were deposited on Si(111) by the spin coating method and studied by scanning electron microscopy (SEM/EDS), atomic force microscopy (AFM), fluorescence spectroscopy and ellipsometry. In the non-absorbing range, the value of the refractive index exhibits normal dispersion between 1.8 and 2.1 for K1_1–K1_3; and between 2.3 and 2.6 for the K2 series of samples established for long wavelengths (longer than 500 nm). The Zn(ii) complexes and their thin layers exhibited fluorescence between 534–573 nm and 495–572 nm for the compounds and the layers, respectively. The highest quantum yield of fluorescence was achieved for K2 in benzene and in the solid state ϕ = 0.78 and 0.58, respectively. The influence of the solvent polarity on the fluorescence properties of the obtained complexes was studied. Additionally, DFT calculations were performed to explain the structures and electronic spectral properties of the complexes.

Tin fluorescent materials were obtained using a spin coating method.     

Three-dimensional porous carbon derived from different organic acid salts for application in electrochemical sensing

Three-dimensional porous carbon materials were synthesized by the one-step pyrolysis of organic salts with different numbers of hydroxyl groups on the side chain (sodium tartrate, sodium malate and sodium succinate). Further, the formation of these porous carbon materials was explored. And then, three kinds of carbon materials were used for constructing electrochemical sensors for nitrite detection, respectively. Porous carbon derived from sodium tartrate (PC_ST) showed the highest electrocatalytic ability for nitrite oxidation among all three materials. The PC_ST-based sensors allow for rapid detection of nitrite in a wide linear range of 0.1–100 μM with a low detection limit of 0.043 μM. The sensor was applied to detect nitrite in meat samples and the results tested by the developed sensor were consistent with the results obtained by HPLC. We envision that PC_ST-based electrochemical sensor is promising as an alternative choice for the development of electrochemical analysis.

Three-dimensional porous carbon materials were synthesized by the one-step pyrolysis of organic salts with different numbers of hydroxyl groups on the side chain (sodium tartrate, sodium malate and sodium succinate).     

Bioresource derived porous carbon from cottonseed hull for removal of triclosan and electrochemical application

Biomass-derived porous carbon materials have drawn considerable attention due to their natural abundance and low cost. In this work, nitrogen enriched porous carbons (NRPCs) with large surface areas were designed and prepared from cottonseed hull via simultaneous carbonization and activation with a facile one-pot approach. The NRPCs were tunable in terms of pore structure, nitrogen content and morphology by adjusting the ratio of the carbon precursor (cottonseed hull), nitrogen source (urea), and activation agent (KOH). The as-synthesized NRPCs exhibited three-dimensional oriented and interlinked porous structure, high specific surface area (1160–2573 m² g⁻¹) and a high level of nitrogen-doping (6.02–10.7%). In a three electrode system, NRPCs prepared at 800 °C with the ratio (cottonseed hull : KOH : urea) of 1 : 1 : 2 (NRPC-112) showed a high specific capacitance of 340 F g⁻¹ at a current density of 0.5 A g⁻¹ and good rate capability (∼80% retention at a current density of 10 A g⁻¹) with 6 M KOH as electrolyte. In a two electrode cell, NRPC-112 demonstrated a high specific capacitance of 304 F g⁻¹ at 0.5 A g⁻¹ and an excellent rate capacity (∼71% retention at current density of 10 A g⁻¹) as well as excellent cycling stability (∼91% retention at 5 A g⁻¹) after 5000 cycles. Furthermore, the NRPCs exhibited an extraordinary adsorption capacity up to 205 mg g⁻¹ for emerging pollutant triclosan. The work provided a sustainable approach to prepare functional carbon materials from biomass-based resource for environment remediation and electrochemical applications.

Biomass derived nitrogen-enriched porous carbon materials from cottonseed hull for emerging pollutant triclosan removal and electrochemical application.     

Synthesis of fluorescent drug molecules for competitive binding assay based on molecularly imprinted polymers

Fluorescent immunosorbent assay (FIA) is very promising for sensitive and selective analysis in bio-medical applications. Here, we proposed an assay, using fluorescent engineering of analytes and the corresponding molecularly imprinted polymers (MIPs) as a plastic antibody. Three drug molecules (metronidazole, zidovudine and lamivudine) were condensed with 9-aminoacridine, using succinic anhydride as a spacer. The target products were characterized with ¹H-NMR, IR and mass spectrometry. UV-vis absorption and fluorescent properties of the fluorophore-labeled drug molecules were investigated. Feasibility of the fluorescent biomimetic immunosorbent assay based on MIPs was demonstrated in the solution. This work will provide sound foundation for the future application in real sample.

Drug molecules (metronidazole, zidovudine and lamivudine) were successfully labelled with a fluorescent reagent and used to develop fluorescent biomimetic immunosorbent assays using molecularly imprinted polymers in the place of natural antibody.     

Highly efficient solar seawater desalination with environmentally friendly hierarchical porous carbons derived from halogen-containing polymers

Desalination of seawater using solar energy is a promising solution to the global freshwater shortage. Ultrahigh surface area (up to 1740 m² g⁻¹) hierarchical porous carbons (HPC) have been prepared by the carbonization of precursors derived from the room temperature dehalogenation of low cost, widely available polyvinyl chloride (PVC) with simple, low cost, environmentally friendly processes. The broad hierarchical pores (from 2 nm to 20 μm) facilitate and ensure fast water and vapor transportation. Flexible photothermal steam generation devices were successfully fabricated with these hierarchical porous carbons on hydrophilic ultrathin (200 μm) paper. An evaporation rate record of 7.87 kg m⁻² h⁻¹ and high energy conversion of 95.8% have been obtained under the concentrated solar intensity of 5 kW m⁻². Our research leads to a new approach to converting halogenated plastics into environmentally friendly and useful porous carbon materials by simple, low-cost processes. It establishes and validates the concept of creating a sustainable and economic pathway to simultaneously recycle halogenated polymers, harvest solar energy and produce clean freshwater.

Hierarchical porous carbon derived from polyvinyl chloride enabled record high evaporation rate and high energy conversion in solar seawater desalination.     

绿色荧光蛋白基因体外转染骨髓源性血管内皮祖细胞

背景:寻找合适的标记分子作为血管内皮祖细胞谱系追踪观察的标志成为其体内、外诱导分化机制研究中的一项重要课题.目的:体外研究绿色荧光蛋白(green fluorescent protein,GFP)基因转染骨髓源性血管内皮祖细胞的方法,并检测基因转染后细胞的生物学特性.设计、时间及地点:细胞基因工程对照观察,于2007-07/2008-05存苏州大学附属第二医院实验中心完成.材料:3周龄清洁级Wistar大鼠15只用于制备骨髓源性血管内皮祖细胞,绿色荧光蛋白基因及重组腺病毒由苏州大学附属第二医院李晓强教授惠赠.方法:体外分离培养Wistar大鼠血管内皮祖细胞,EGM-2MV培养基培养大鼠骨髓中的单个核细胞.以腺病毒为载体,293A细胞为包装细胞,介导GFP转染血管内皮祖细胞,与末转染的同期细胞作对照.主要观察指标:在荧光显微镜下观察GFP表达效率.酶联免疫吸附法检测培养上清中血管内皮生长因予蛋白水平评价GFP转染血管内皮祖细胞后对细胞功能的影响,MTT法计价GFP转染血管内皮祖细胞后对细胞活性的影响.结果:成功构建了携带绿色荧光蚩白基因的重组腺病毒(Ad-GFP),成功培养了大鼠骨髓源性内皮祖细胞,重组Ad-GFP可高效率转染血管内皮祖细胞,病毒感染组阳性细胞与末感染组细胞血管内皮生长因子蛋白水平表达相当,Ad-GFP转染后对血管内皮祖细胞的增殖没有影响.结论:构建了带有GFP的缺陷型重组Ad-GFP,转染Wistar大鼠血管内皮祖细胞得到了高效表达,且感染细胞的生物学特性和增殖能力未受影响.     

Porous carbon material derived from fungal hyphae and its application for the removal of dye

In this work, fungal hyphae (FH, Irpex lacteus) was used as the carbon resource for the preparation of porous carbon materials (PCFH) using mixed alkali as the activator. The SEM, N₂ adsorption/desorption, FT-IR, XRD, Raman, and XPS were used to characterize the structure and surface properties of PCFH. The results showed that the PCFH not only has a huge Brunauer–Emmett–Teller (BET) surface area (2480 m² g⁻¹), but also has abundant functional groups containing carbon, oxygen, and nitrogen. Rhodamine B (RhB) was selected to evaluate the adsorption properties of the PCFH prepared under different conditions in dyeing wastewater. A fast adsorption rate was observed, and an uptake capacity of 765 mg g⁻¹ was achieved in the initial 5 min. The maximum adsorption capacity of PCFH to RhB reached 1912 mg g⁻¹ at the pH value of 9, which could efficiently remove RhB from the aqueous solution. The adsorption process was fitted better by a pseudo-second order model, and the adsorption isotherm for the RhB was well fitted by the Freundlich model. Moreover, the probable mechanism of adsorption was analyzed. In short, the good adsorption performance of PCFH indicated that it has a broad application prospect for dye water pollution control.

A highly porous carbon material based on fungal hyphae was prepared using mixed alkali and its application for removal of dye investigated.     

Antitumor activity of some organotin complexes of hydroxamic acids derived from dibasic carboxylic acid

The sensitivities of normal and preneoplastic rat hepatocytes have been tested against four organotin hydroxamates in vitro. These organotin hydroxamates are soluble in lipids but not in aqueous medium. The solubility in lipid had initially been utilized in the pilot experiments with Ehrlich ascites tumor cells containing lipids in the ascites fluid. Cytochemical staining of protein and the growths of drug-treated cells in vivo have been studied for Ehrlich ascites tumor cells. Measurement of DNA synthesis, protein content and the cytochemical staining of protein have been employed for normal and preneoplastic hepatocytes. Ehrlich ascites tumor cells and the preneoplastic hepatocytes are markedly sensitive to organotin hydroxamates whereas the normal hepatocytes are less sensitive to these chemicals. The results of the present work are significant, and it may be worthwhile to study the further drug action in vivo.     

Basophilic green fluorescent carbon nanoparticles derived from benzoxazine for the detection of Cr(vi) in a strongly alkaline environment

Fluorescent probes for heavy or transition metal ions in extreme environments are crucially important for practical use. In this work, basophilic green fluorescent carbon nanoparticles (G-CNPs) were synthesized by one-pot hydrothermal treatment of benzoxazine in NaOH aqueous solution. These G-CNPs showed favorable dispersibility in strongly alkaline conditions due to the abundant functional groups on their surface. Based on their good photoluminescence properties and excellent stability, the G-CNPs could be used to detect Cr(vi) in a strongly alkaline environment (pH = 14) through a fluorescence quenching effect. This detection process was achieved selectively among 17 anions within 30 seconds and the limitation was 0.58 μM (S/N = 3). It was revealed that the fluorescence turn-off process was caused by the inner filter effect (IFE) of Cr(vi). This study developed efficient fluorescence sensors based on fluorescent carbon nanoparticles, which could be used in strongly alkaline environments.

Basophilic green fluorescent carbon nanoparticles (G-CNPs) were prepared from benzoxazine for the selective detection of Cr(vi) in strongly alkaline environments.     

慢病毒载体介导绿色荧光蛋白转染大鼠牙髓干细胞

背景：对牙髓干细胞进行稳定高效安全的体外标记是示踪技术中首先需要解决的问题,也是牙齿再生体内研究的基础。 目的：探讨慢病毒载体介导绿色荧光蛋白转染大鼠牙髓干细胞的理想条件及方法,并确定其转染后是否保持干细胞特性。 方法：通过改良酶消化法获得大鼠牙髓干细胞,对其免疫表型及分化潜能进行鉴定,以感染复数为5,10,25,50和100的慢病毒载体介导绿色荧光蛋白作用24 h和48 h,倒置显微镜下检测转染率和荧光强度,并对大鼠牙髓干细胞感染前后的克隆增殖能力、细胞周期及牙向分化能力进行比较,评价感染对其生物学特性的影响。 结果与结论：流式细胞仪检测结果显示大鼠牙髓干细胞STRO-1和CD146表达阳性,CD34和CD45表达阴性,经相应诱导培养后可向成骨和成脂分化。当感染复数为50,作用时间为48 h时,转染效率最高,荧光表达最强;感染前后细胞增殖、克隆形成率及细胞周期等方面差异无显著性意义（P＞0.05）,碱性磷酸酶阳性表达。说明感染复数为50作用48 h是慢病毒载体介导绿色荧光蛋白转染大鼠牙髓干细胞的理想条件,且不影响牙髓干细胞生物学特性,为大鼠牙髓干细胞的体内研究提供了可靠的示踪方法。     

Mannich bases derived from lawsone and their metal complexes: synthetic strategies and biological properties

Lawsone (2-hydroxynaphthalene-1,4-dione) is a natural product which shows significant biological activity. Aminomethylnaphthoquinone Mannich bases derived from lawsone constitute an interesting class of naphthoquinones and/or their metal complexes have demonstrated a series of important biological properties. So, this review aimed to document the publications concerning the synthesis of aminomethylnaphthoquinone Mannich bases from lowsone, aldehydes and amines and their metal complexes using different conditions, and investigation of their applications.

Lawsone (2-hydroxynaphthalene-1,4-dione) is a natural product which shows significant biological activity.     

预防住院病人跌倒的安全防御体系的构建及其应用

[目的]探讨预防住院病人跌倒事件发生的安全防护体系的构建及其应用效果。[方法]完善制度、规范护士培训、定期检查病房的环境、设施及警示标识情况、制订持续健康教育方案、建立通畅的上报系统。[结果]实施安全防御体系后,住院病人跌倒事件发生率较实施前明显下降。[结论]建立安全防御体系可减少跌倒事件的发生。