Platform for Highly Sensitive Alkaline Phosphatase‐Based Immunosensors Using 1‐Naphthyl Phosphate and an Avidin‐Modified Indium Tin Oxide Electrode

We report a versatile platform for highly sensitive alkaline phosphatase (ALP)‐based electrochemical biosensors that uses an avidin‐modified indium tin oxide (ITO) electrode as a sensing electrode and 1‐naphthyl phosphate (NPP) as an ALP substrate. Almost no electrocatalytic activity of NPP and good electrocatalytic activity of 1‐naphthol (ALP product) on the ITO electrodes allow a high signal‐to‐background ratio. The effective surface covering of avidin on the ITO electrodes allows very low levels of nonspecific binding of proteins to the sensing electrodes. The platform technology is used to detect mouse IgG with a detection limit of 1.0 pg/mL.     

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     

Convergence theorems based on hybrid methods for generalized equilibrium problems and fixed point problems

The purpose of this work is to introduce a hybrid projection method for finding a common element of the set of a generalized equilibrium problem, the set of solutions to a variational inequality and the set of fixed points of a strict pseudo-contraction in a real Hilbert space.     

The Rogers-Ramanujan continued fraction and a new Eisenstein series identity

With two elementary trigonometric sums and the Jacobi theta function θ₁, we provide a new proof of two Ramanujan's identities for the Rogers-Ramanujan continued fraction in his lost notebook. We further derive a new Eisenstein series identity associated with the Rogers-Ramanujan continued fraction.     

The minimal prime spectrum of rings with annihilator conditions

In this paper, we study rings with the annihilator condition (a.c.) and rings whose space of minimal prime ideals, , is compact. We begin by extending the definition of (a.c.) to noncommutative rings. We then show that several extensions over semiprime rings have (a.c.). Moreover, we investigate the annihilator condition under the formation of matrix rings and classical quotient rings. Finally, we prove that if R is a reduced ring then: the classical right quotient ring Q(R) is strongly regular if and only if R has a Property (A) and is compact, if and only if R has (a.c.) and is compact. This extends several results about commutative rings with (a.c.) to the noncommutative setting.     

On products of quadratic twists and ranks of elliptic curves over large fields

In this paper, we give examples of elliptic curves E/K overa number field K satisfying the property that there exist P₁,P₂ K[t] such that the twists and are of positiverank over K(t). As a consequence of this result on twists, weshow that for those elliptic curves E/K, and for each , the rank of E over the fixed field (K^ab) under is infinite, where K^ab is the maximal abelian extension ofK.     

全流通格局下沪市主并上市公司并购绩效研究

以全流通格局下2007年发生并购的56家上市公司为样本,应用超常收益方法对沪市主并上市公司并购的绩效进行实证研究.结果表明:主并上市公司并购后绩效呈上升趋势;在横向并购、纵向并购和混合并购三种方式中,纵向并购的效果优于横向并购和混合并购,而横向并购与混合并购对绩效的影响区别不明显.     

Ferroelectric metal-organic framework with a high dielectric constant

Hydrothermal reaction of (l)-N-(4'-cyanobenzy)-(S)-proline with CdCl2 as a Lewis acid catalyst and NaN3 gives colorless block compound 1, in which 1 displays a complicated 3D framework. Ferroelectric and dielectric property measurements reveal that 1 exhibits physical properties comparable to that of a typical ferroelectric compound with a dipole relaxation process and a dielectric constant of ca. 38.6 that makes it, by definition, a high dielectric material.     

Analyses of Stemona alkaloids in Stemona tuberosa by liquid chromatography/tandem mass spectrometry

Alkaloid profiles in Stemona tuberosa were found to be highly variable. Six Stemona alkaloids isolated from the plant were subjected to on-line high-performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI-MS) and tandem mass spectrometry (MS/MS) analyses. Their fragmentation patterns and products were useful for their characterization. The LC/MS fingerprints of these alkaloids, though variable among samples, could provide an overall characterization of the authenticity and quality of this species and help to differentiate it from S. japonica and S. sessilifolia, as all three species are recognized as genuine sources of the herb Radix Stemonae in the Pharmacopoeia of the People's Republic of China.     

"Orthogonal" separations for reversed-phase liquid chromatography

A general procedure is proposed for the rapid development of a reversed-phase liquid chromatographic (RP-LC) separation that is "orthogonal" to a pre-existing ("primary") method for the RP-LC separation of a given sample. The procedure involves a change of the mobile-phase organic solvent (B-solvent), the replacement of the primary column by one of very different selectivity, and (only if necessary) a change in mobile phase pH or the use of a third column. Following the selection of the "orthogonal" B-solvent, column and mobile phase pH, further optimization of peak spacing and resolution can be achieved by varying separation temperature and either isocratic %B or gradient time. The relative "orthogonality" of the primary and "orthogonal" RP-LC methods is then evaluated from plots of retention for one method versus the other. The present procedure was used to develop "orthogonal" methods for nine routine RP-LC methods from six pharmaceutical analysis laboratories. The relative success of this approach can be judged from the results reported here.