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Aiming at the problem of precision driving and vibration suppression for sensitive payloads on-orbit, this paper proposes a new compliant platform based on an embedded superstructure and a smart material actuator. Firstly, the main structure of the platform is designed and optimized to achieve the expected indicators via the response surface method. Then, the vibration reduction mechanism of the platform with the embedded superstructure is studied by establishing an equivalent model. Following that, a four-phase superstructure is matched and designed with a compact space, and the results are verified by finite element modal analysis. Finally, both the tensioning performance and vibration reduction performance under fixed frequency harmonic disturbance are studied via transient dynamic simulation. Based on the obtained results, directions for future improvements are proposed. The relevant conclusions can provide a reference for function integration of precision tensioning and vibration suppression. [ABSTRACT FROM AUTHOR]

Hypochlorous acid (HOCl) is widely used in daily production and life because of its green and strongly oxidizing properties. Additionally, as a vital reactive oxygen species (ROS), it is an innate immune system weapon and performs a critical function in many pathophysiology processes. In this paper, a novel water-soluble fluorescent probe, BMH, with excellent performance is designed and synthesized by simple condensation of benzocoumarin and 2-mercaptoethanol. BMH has specific selectivity, excellent sensitivity, ultra-fast response (<3 s), and a wide pH detection range. The fluorescence intensity of BMH has an excellent linear correlation with the concentration of HOCl in the scope of 0–10 μM, and the calculated detection limit (DL) is 2.45 nM. The intramolecular charge transfer (ICT) sensing mechanism of BL has been verified by fluorescence, UV, and MS studies as well as density functional theory (DFT) calculations. Furthermore, BMH can be incorporated into a solid-state visual sensor to detect HOCl conveniently. BMH was applied to detect HOCl-spiked actual water samples and achieved satisfying recovery rates. Also, the low-toxicity BMH can be successfully used to track changes in endogenous/exogenous HOCl in living cells. In short, BL provides a robust and reliable monitoring tool to reveal the biological functions of HOCl and ensure its safe use. [ABSTRACT FROM AUTHOR]

Given that peroxynitrite (ONOO − ) is profoundly associated with health and diseases, a new fluorescent probe ABT was designed and synthesized for detection of ONOO − . ABT manifested not only ratiometric fluorescence signals simultaneously in response to concentrations of ONOO − (within 10 s), but high selectivity and sensitivity towards ONOO − over other physiological relevant species (detection limit = 26.3 nM). Moreover, ABT worked in a broad pH range with biological relevance. Thus, ABT could be used to quantitative detection of ONOO − concentration and has the potential to efficiently monitor ONOO − in living organisms. [ABSTRACT FROM AUTHOR]

The three-dimensional porous Fe3O4@Cu2−xS–MoS2 framework is reported for the first time. The as-prepared 3D framework exhibits good structural stability, high surface area, enhanced adsorption capacity to substrates, and strong absorption in the NIR range. As a result, such hybrid frameworks exhibit excellent NIR-light photocatalytic activity and stable cycling for the direct arylation of heteroaromatics at room temperature. [ABSTRACT FROM AUTHOR]

The application of nanohybrids in water treatment by the catalytic degradation of various pollutants has attracted much attention from researchers. Here, the Pd/Fe3O4-PEI-RGO nanohybrids (1d) with high shape selectivity and high specific surface area have been synthesized by the dispersion of Pd NPs and Fe3O4 NPs on PEI modified graphene oxide sheets. These nanohybrids show superior catalytic activity toward methylene blue with a high degradation efficiency above 99% in the presence of NaBH4 in aqueous solution, which is attributed to the effects of the Pd NPs supported on reduced graphene oxide nanosheets. Meanwhile, the 1d catalyst can be easily separated from the reaction mixture by applying an external magnetic field. The catalyst was recycled nine times without showing any significant loss in its activity. Such features enable this catalyst for promising application in catalysis, environment, and new energy fields. [ABSTRACT FROM AUTHOR]

Low cost, high activity and selectivity, convenient separation, and increased reusability are the main requirements for noble-metal-nanocatalyst-catalyzed reactions. Despite tremendous efforts, developing noble-metal nanocatalysts to meet the above requirements remains a significant challenge. Here we present a general strategy for the preparation of strongly coupled Fe3O4 and palladium nanoparticles (PdNPs) to graphene sheets by employing polyethyleneimine as the coupling linker. Transmission electron microscopic images show that Pd and Fe3O4 nanoparticles are highly dispersed on the graphene surface, and the mean particle size of Pd is around 3 nm. This nanocatalyst exhibits synergistic catalysis by Pd nanoparticles supported on reduced graphene oxide (rGO) and a tertiary amine of polyethyleneimine (Pd/Fe3O4/PEI/rGO) for the Tsuji-Trost reaction in water and air. For example, the reaction of ethyl acetoacetate with allyl ethyl carbonate afforded the allylated product in more than 99 % isolated yield, and the turnover frequency reached 2200 h−1. The yield of allylated products was 66 % for Pd/rGO without polyethyleneimine. The catalyst could be readily recycled by a magnet and reused more than 30 times without appreciable loss of activity. In addition, only about 7.5 % of Pd species leached off after 20 cycles, thus rendering this catalyst safer for the environment. [ABSTRACT FROM AUTHOR]

A new fluorescent derivative (1) containing coumarin exhibits Fe(III)-selective strong yellow-green fluorescence in ethanol. This compound could be used as an “off-on” chemosensor and allow the detection of Fe3+by monitoring changes in absorption and fluorescence spectra. Upon addition of Fe3+, an overall emission change of 125-fold was observed. High selectivity and sensitivity were observed over other metal ions, mainly due to the spirolactam ring-opening power of Fe3+. The detection limit was as low as 5.6?ppb. Photo-induced electron transfer, coupled with intramolecular charge transfer are proposed to account for the observed spectral response. [ABSTRACT FROM PUBLISHER]

Abstract: A novel and facile strategy was firstly developed to synthesize an efficient magnetic resonance imaging contrast agent via linking the Gd-complex (Gd-DTPA) onto the surfaces of ferroferric oxide nanoparticles. The new contrast agent is easily soluble in water media and shows better targeting ability on the liver organ. In addition, the synthesized contrast agent shows excellent magnetic resonance contrast behavior with longitudinal relaxivity value of 62.58mM−1 s−1 and emits strong bright fluorescence in the cellular environment. Furthermore, the new magnetic resonance imaging contrast agent is superparamagnetic at room temperature and has no apparent cytotoxicity on human HeLa cells. [Copyright &y& Elsevier]

Abstract: In the paper, a novel mutli-wavelength emissive aluminium ion chemosensor based on 3-[1′-(2′-hydroxy-α-methylbenzylidene-imino)]-2-(p-N,N-dimethyl aminophenyl)-1,2-dihydroquinazolin-4-(3H)-one is designed and synthesized. According to the fluorescence behavior toward several metal ions, it shows high selectivity to Al3+ over other commonly coexistent metal ions (Na+, Mg2+, Co2+, Ni2+, Cu2+, Fe3+, Cr3+, Hg2+, Zn2+, Cd2+) in aqueous environment (pH 7.40). Meanwhile the binding constant between Al3+ and chemosensor achieves 3.92×106 M−1 in aqueous media. Moreover, according to the Job plot, 1:1 stoichiometry between Al3+ and the sensor was deduced in aqueous media (pH 7.4). The good selectivity and sensitivity in aqueous media effectively enhance the application value of the chemosensor for Al3+. [Copyright &y& Elsevier]

8-hydroxyquinoline-5-carbaldehyde-(benzotriazol-1′-acetyl)hydrazone1was synthesized and found to show sensitivity and selectivity to Mg2+. Compared to other metal ions, the fluorescence intensity of1increased 65-fold upon addition of Mg2+with a low detection limit of 2.4 ppb in acetonitrile. [ABSTRACT FROM AUTHOR]

A Schiff-base fluorescent sensor, 7-methoxychromone-3-carbaldehyde-(3′,4′-dimethyl)pyrrole hydrazone (MCPH), was synthesized. The new sensor showed high selectivity for Al3+ over other metal ions examined in acetonitrile. Upon binding Al3+, a significant fluorescence enhancement with a turn-on ratio over 101-fold was triggered. The detection limit of MCPH for Al3+ was 2.5 × 10−7 mol L−1. [ABSTRACT FROM AUTHOR]

Abstract: Iron oxide magnetic nanoparticles were covalently modified by a fluorescent 8-aminoquinoline derivative and formed an optical sensor to be used as a highly sensitive and selective Zn2+ ions fluorescent nanosensor in aqueous solution at pH 7.0. The nanosensor was sufficiently characterized by physicochemical methods. The sensor can detect Zn2+ ions in aqueous solution with a submicromolar sensitivity of 0.1μM, and the interfering metal ions cannot influence its selectivity. MTT assay experiments indicated that the sensor showed no apparent cytotoxicity. [Copyright &y& Elsevier]

A Schiff-base ligand derived from 1-phenyl-3-methyl-4-formyl-2-pyrazolin-5-one (PMFP) and isoniazid was prepared and its La(III) complex was characterized by X-ray single crystal diffraction. The La(III) is nine-coordinate in a space group P21/n. DNA-binding was investigated by UV-Vis, fluorescence titration, ethidium bromide displacement experiments, and viscosity measurements, which indicated that the ligand and La(III) complex strongly binds to calf thymus DNA presumably via groove binding and intercalation. The intrinsic binding constants of the ligand and La(III) complex were 0.86 × 105 and 2.46 × 105 mol L−1, respectively. Antioxidant data from hydroxyl radical scavenging experiments in vitro suggest that the La(III) complex possesses higher scavenging ratio than the free ligand, metallic salt, and some standard antioxidants like mannitol. [ABSTRACT FROM AUTHOR]

Structural analyses indicate that the ligand and lanthanide ions form mononuclear 10-coordinate ([Ln L2 · (NO3)2] · NO3 [Ln(III) = La, Sm, Nd, and Yb; L is chromone-3-carbaldehyde-(isonicotinoyl) hydrazone) complexes with 1 : 2 metal-to-ligand stoichiometry. DNA-binding studies show that the ligand and its lanthanide complexes can bind to calf thymus DNA via an intercalation mode with binding constants of 105 (mol L-1)-1, and the lanthanide complexes bind stronger than the free ligand alone. Antioxidant activities of the ligand and lanthanide complexes were determined by superoxide and hydroxyl radical scavenging methods in vitro. The ligand and complexes possess strong scavenging effects, and the lanthanide complexes show stronger antioxidant activities than the ligand and some standard antioxidants, such as vitamin C. [ABSTRACT FROM AUTHOR]

In this paper, two novel porphyrinogen-like macrocycle ligands were synthesized and characterized with elemental analyses, 1H NMR, FAB-Ms, and IR methods. [ABSTRACT FROM AUTHOR]

A multifunctional nanoprobe, which can be used for dual modal imaging and the detection of cancer cells, has been reported. [ABSTRACT FROM AUTHOR]

Highlights: [•] A novel water-soluble fluorescent chemosensor based on naphthalene derivate was designed. [•] The fluorescent chemosensor for Al3+ could be synthesized simply. [•] The fluorescent sensor exhibited high selectivity for Al3+ in absolute water media (pH=7.0). [ABSTRACT FROM AUTHOR]

Abstract: Iron phosphate(III) was prepared by thermal decomposition of organophosphonates Fe(III)OPO(OC6H4COO)2·0.5H2O and FePO4·1.5H2O in air atmosphere. The resulting materials were characterized by chemical analysis, TG/DTA, XRD, SEM and electrochemical characterization. The effect of preparing methods, sintering time and temperature on their crystalline structure, particle morphology and electrochemistry properties was investigated. The materials obtained from Fe(III) carboxy-phenyl phosphate annealed at 380°C for 9h showed the highest discharge capacity of about 146mAh/g for the first cycle at the rate of 0.05mA/cm2. Compared with homogeneous precipitation method, the coordinate precipitation method favors the synthesis of suitable cathode materials with low crystal structure, relatively small grain size and minor remains carbons that is beneficial for improving the electrochemical performance. [Copyright &y& Elsevier]

Abstract: Series LiFePO4/C materials have been prepared by a so-called reformative solid-coordination method, which uses citric acid as the coordination agent and carbon source. A monodenate coordination band of –COO-M was proved to form gradually and that would help to disperse Li+ or Fe2+ among the homogeneous gel during the grinding process. Impure phase Fe2P was detected out among the LiFePO4/C composites with increasing annealed temperature. The remnant coating carbon was considered to be the reductive under the pure nitrogen gas. The amounts of carbon, particle size and morphology were investigated in detail and all the results showed to be related to the formation of Fe2P. The electro-conductive Fe2P phase among LiFePO4/C composites acts as important role in increasing electronic conductivity and evidently improves the electrochemical performance of LiFePO4/C including the less polarization phenomenon, comparatively high reversible capability, stable cycling performance and slight trend of less loss of rate capability. [Copyright &y& Elsevier]