Structures and Magnetic Properties of Two Copper(II) Complexes with 2,5‐Dichloro‐3,6‐Dihydroxy‐1,4‐Benzoquinone Dianionic and Tetrachloroquinone Ligand

The polynuclear copper(II) complex [Cu₂(Hdpa)₂(μ‐ClDHBQ)(ClO₄)₂]_n, 1 is bridged by ClDHBQ^?2 (2,5‐dichloro‐3,6‐dihydroxy‐1,4‐benzoquinone dianionic) and 2,2′‐dipyridylamine (Hdpa). In the axial position, Cu is connected with the oxygen atom of ClO. The perchlorate anion may be envisaged as a monodentate O‐bound ligand. Through the bond bridge of O–Cu … O–Cl, the binuclear compound [Cu₂(Hdpa)₂(μ‐ClDHBQ)(ClO₄)₂] is strung together into a long chain compound. Tetrachlorocatechol underwent partial oxidation/hydrolysis/dechlorination processes to produce ClDHBQ^?2. The other mononuclear complex [Cu(Hdpa)(TeCQ)](DMF), 2 , in which tetrachloroquinone (TeCQ) was produced by oxidation of tetrachlorocatechol (TeCC), therefore complex 2 is in the quinone form. The magnetic susceptibility measurements show antiferromagnetic coupling with J = ?11.9 cm^?1, θ = 2.6 K, and g = 2.05 for complex 1. Complex 2 exhibits the typical paramagnetic behavior of s = 1/2.     

Quantitative analysis of human serum leptin using a nanoarray protein chip based on single-molecule sandwich immunoassay

We report a method for the quantitative analysis of human serum leptin, which is a protein hormone associated with obesity, using a nanoarray protein chip based on a single-molecule sandwich immunoassay. The nanoarray patterning of a biotin-probe with a spot diameter of 150 nm on a self-assembled monolayer functionalized by MPTMS on a glass substrate was successfully accomplished using atomic force microscopy (AFM)-based dip-pen nanolithography (DPN). Unlabeled leptin protein molecules in human serum were detected based on the sandwich fluorescence immunoassay by total internal reflection fluorescence microscopy (TIRFM). The linear regression equation for leptin in the range of 100 zM-400 aM was determined to be y = 456.35x + 80,382 (R = 0.9901). The accuracy and sensitivity of the chip assay were clinically validated by comparing the leptin level in adult serum obtained by this method with those measured using the enzyme-linked immunosorbent assay (ELISA) performed with the same leptin standards and serum samples. In contrast to conventional ELISA techniques, the proposed chip methodology exhibited the advantages of ultra-sensitivity, a smaller sample volume and faster analysis time.     

Voltammetric Antioxidant Analysis in Mineral Oil Samples Immobilized into Boron‐Doped Diamond Micropore Array Electrodes

Mineral oil microdroplets containing the model antioxidant N,N‐didodecyl‐N′,N′‐diethyl‐phenylene‐diamine (DDPD) are immobilized into a 100×100 pore‐array (ca. 10 μm individual pore diameter, 100 μm pitch) in a boron‐doped diamond electrode surface. The robust diamond surface allows pore filling, cleaning, and reuse without damage to the electrode surface. The electrode is immersed into aqueous electrolyte media, and voltammetric responses for the oxidation of DDPD are obtained. In order to further improve the current responses, 20 wt% of carbon nanofibers are co‐deposited with the oil into the pore array. Voltammetric signals are consistent with the oxidation of DDPD and the associated transfer of perchlorate anions (in aqueous 0.1 M NaClO₄) or the transfer of protons (in aqueous 0.1 M HClO₄). From the magnitude of the current response, the DDPD content in the mineral oil can be determined down to less than 1 wt% levels. Perhaps surprisingly, the reversible (or midpoint) potential for the DDPD oxidation in mineral oil (when immersed in 0.1 NaClO₄) is shown to be concentration‐dependent and to shift to more positive potential values for more dilute DDPD in mineral oil solutions. An extraction mechanism and the formation of a separate organic product phase are proposed to explain this behavior.     

Lysophosphatidylglycerol inhibits formyl peptide receptor like-1-stimulated chemotactic migration and IL-1�� production from human phagocytes

In this study, we observed that lysophosphatidylglycerol (LPG) completely inhibited a formyl peptide receptor like-1 (FPRL1) agonist (MMK-1)-stimulated chemotactic migration in human phagocytes, such as neutrophils and monocytes. LPG also dramatically inhibited IL-1β production by another FPRL1 agonist serum amyloid A (SAA) in human phagocytes. However, LPG itself induced intracellular calcium increase and superoxide anion production in human phagocytes. Keeping in mind that phagocytes migration and IL-1β production by FPRL1 are important for the induction of inflammatory response, our data suggest that LPG can be regarded as a useful material for the modulation of inflammatory response induced by FPRL1 activation.     

All‐in‐One Target‐Cell‐Specific Magnetic Nanoparticles for Simultaneous Molecular Imaging and siRNA Delivery

Cancer‐cell‐targeted gene silencing was observed with a magnetic‐nanoparticle platform (MEIO, magnetism‐engineered iron oxide) on which a fluorescent dye, siRNA, and a RGD‐peptide targeting moiety were attached (see picture). The different functionalities enable the macroscopic (magnetic resonance) and microscopic (fluorescence) imaging of target cells. This system may be suitable for concurrent diagnostic and therapeutic applications.

     

Loading of Exponentially Grown LBL Films with Silver Nanoparticles and Their Application to Generalized SERS Detection

Feature film : Thin films made by exponential layer‐by‐layer growth display high diffusivity and can be readily infiltrated with inorganic nanoparticles. They can sequestrate molecular systems from solution as a function of the composition of their layers, while providing intense surface‐enhanced Raman scattering (SERS) signals (see picture).

     

Self‐Assembled Organic Microtubes from Amphiphilic Molecules

Getting the sizes sorted out : In recent years, there have been increasing numbers of reports about self‐assembled nano‐ or microtubular structures because of their potential uses in a variety of technical applications, which are largely determined by the tube sizes. This Focus Review highlights microsized self‐assembled organic tubular structures formed in aqueous solutions and organic solvents.

     

Highly Selective Dopamine Sensor based on an Imprinted SAM/Mediator Gold Electrode

A new concept of molecular imprinted polymer (MIP) electrode was proposed for amperometric detection of dopamine (DA). The MIP electrode was fabricated based on a screen-printed gold electrode. Thioglycolic acid (TGA) and allyl mercaptan (AM) were bounded on the gold electrode by covalent bonding to control the TGA density. The mediator, quercetin (Q), was also covalently bonded to the carboxyl group of TGA by using the carboxyl activation agent: 1-ethyl-3-(3-dimethylamino-propyl) carbodiimide (EDC). Molecularly imprinted poly(methyl methacrylate) (PMMA) was polymerized by UV curing. Different surface distribution densities of TGA were studied for realizing the recognition abilities of MIP electrodes. The TGA density was well controlled on the gold surface and the DA recognition ability was correlated to it.     

Finding almost squares IV

In this paper, we continue the study of almost squares; these are integers n representable as n = a · b for some . We show that almost all (in the measure–theoretic sense) short intervals [x, x + (log x)¹²] contain at least one almost square, and we consider related questions. Moreover, a result of Erdős shows that the exponent 12 cannot be smaller than 0.086 .... Received: 26 June 2008; Revised: 22 December 2008