Amperometric immunosensor for detection of antibodies of Salmonella typhi in patient serum

An amperometric sensor for detection of antibodies to Salmonella typhi in the serum of patients was developed. This involved usage of screen-printed electrodes and recombinant flagellin fusion protein. An indirect enzyme-linked immunosorbant assay was used for detection of antibodies to S. typhi in the patient serum. The screen-printed electrodes were made using polystyrene and graphite. These electrodes were tested for their ability to detect 1-naphthol, which is the product formed due to the hydrolysis of the substrate 1-naphthyl phosphate by the enzyme alkaline phosphatase. These electrodes were coated with recombinant flagellin fusion protein made by recombinant DNA technology and blocked with bovine serum albumin (BSA). Further they were incubated with patient serum and goat anti-human alkaline phosphatase conjugate. The immunosensing was performed by using amperometric method. Pooled human serum samples from apparently healthy individuals were used as control. Both the pooled healthy human serum samples and patient sera were subjected to Widal agglutination test and amperometric method. A 100% correlation was found between the Widal test and amperometric method. The time taken for the detection by electrochemical method is 1 h and 15 min, while the time taken by Widal test is 18 h.     

Singular positone and semipositone boundary value problems of second order delay differential equations

In this paper we present some new existence results for singular positone and semipositone boundary value problems of second order delay differential equations. Throughout our nonlinearity may be singular in its dependent variable.     

An infinite interval problem arising in circularly symmetric deformations of shallow membrane caps

Existence results are presented for singular boundary value problems modelling phenomena which arise in the theory of shallow membrane caps.     

Anti‐periodic solutions for evolution equations with mappings in the class (S+)

In this paper, we study the existence of anti‐periodic solutions for the first order evolution equation in a Hilbert space H, where G : H → ? is an even function such that ?G is a mapping of class (S₊) and f : ? → ? satisfies f(t + T) = –f(t) for any t ∈ ? with f(·) ∈ L²(0, T; H). (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Fixed point theory for composite maps on almost dominating extension spaces

New fixed point results are presented forU _c ^k (X, X) maps in extension type spaces.     

Fixed points forM ⋆ and regularly approximable maps

Several new fixed point results are presented for set valued maps. The maps we discuss are either ofM ^* type or of regularly approximable type.47H10     

A general approach to nonlinear multiple control problems with perturbation consideration

In this paper, we consider a general nonlinear optimal control problem involving multiple criteria. We show that the problem can be transformed into a standard optimal control problem, and hence, is solvable by conventional techniques. However, the optimal control so obtained is of open loop nature and is rather sensitive to perturbations. Based on the first-order approximation, neighboring extremal approach is used to obtain a local linear feedback correction control law, leading to a combined controller. Two numerical examples are solved using the proposed method to demonstrate the effectiveness of the combined control.     

Nonexistence of positive solutions for 2 order integro-differential inequalities

In this paper, we shall show that under suitable conditions on f and K, the inequalities

imply that the integro-differential inequalities

have no positive solutions, respectively.     

Computing the Writhing Number of a Polygonal Knot

The writhing number measures the global geometry of a closed space curve or knot. We show that this measure is related to the average winding number of its Gauss map. Using this relationship, we give an algorithm for computing the writhing number for a polygonal knot with n edges in time roughly proportional to n^1.6. We also implement a different, simple algorithm and provide experimental evidence for its practical efficiency.     

The Discrete 2-Center Problem

We present an algorithm for computing the discrete 2-center of a set P of n points in the plane; that is, computing two congruent disks of smallest possible radius, centered at two points of P , whose union covers P . Our algorithm runs in time O(n ^4/3 log ⁵ n) . Received July 18, 1997, and in revised form March 17, 1998.