Partially conserved axial-vector current inS-matrix theory

Mandelstam�s argument that PCAC follows from assigning Lorentz quantum numberM=1 to the massless pion is examined in the context of multiparticle dual resonance model. We construct a factorisable dual model for pions which is formulated operatorially on the harmonic oscillator Fock space along the lines of Neveu-Schwarz model. The model has bothm ? andm ? as arbitrary parameters unconstrained by the duality requirement. Adler self-consistency condition is satisfied if and only if the conditionm?2?m?2=1/2 is imposed, in which case the model reduces to the chiral dual pion model of Neveu and Thorn, and Schwarz. The Lorentz quantum number of the pion in the dual model is shown to beM=0.

Isolation Of A Cytokinin-Binding Protein From Cucumis-Sativus Cotyledons

A cytokinin-binding protein which exists as monomer and dimer was isolated from cucumber (Cucumis sativus L. var Guntur) cotyledons by affinity chromatography on AH-Sepharose-pi6 Ap /s> column. The protein bound to [3H]-N6-(Δ2-isopentenyl) adenosine trialcohol. On Sephadex G-50 chromatography it gave 2 peaks corresponding to molecular weight 4000 and 8000 daltons. On sodium dodecyl sulphate-polyacrylamide gel electrophoresis, it gave only one band with an apparent molecular weight of 4000 daltons.

A matrix identity and perturbation expressions

An identity expressing formally the diagonal and off-diagonal elements of an inverse of a matrix is deduced employing operator techniques. Several well-known perturbation expressions for the self-energy are deduced as special cases. A new approximation and other applications following from the above formalism are briefly indicated through illustrations from a perturbed harmonic oscillator, chemisorption approximations and Kelly's result in the problem of electron correlation.

On computing an equivalent symmetric matrix for a nonsymmetric matrix

A real or a complex symmetric matrix is defined here as an equivalent symmetric matrix for a real nonsymmetric matrix if both have the same eigenvalues. An equivalent symmetric matrix is useful in computing the eigenvalues of a real nonsymmetric matrix. A procedure to compute equivalent symmetric matrices and its mathematical foundation are presented.

Rapid isolation of lysyl-tRNA synthetase from rat liver

The high molecular weight aminoacyl-tRNA synthetase complex (the 24S complex) was isolated from rat liver by ultracentrifugation. The lysyl-tRNA synthetase (E.C. 6.1.1.6) was selectively dissociated by hydrophobic interaction chromatography on 1,6 diaminohexyl agarose followed by hydroxylapatite chromatography and DEAE chromatography. The lysyl-tRNA synthetase dissociated from the 24S synthetase complex was purified approximately to 2700 fold with 14% yield.

An integer arithmetic method to compute generalized matrix inverse and solve linear equations exactly

An algorithm that uses integer arithmetic is suggested. It transforms anm ×n matrix to a diagonal form (of the structure of Smith Normal Form). Then it computes a reflexive generalized inverse of the matrix exactly and hence solves a system of linear equations error-free.

Chemical approaches of penicillin allergy—III Isolation of the penicillin-free carrier receptor protein (CRP) on a polymeric 7-deoxy penicillin analogue template and its role in penicillin immunogeneses in rabbit and man

Specific penicillin-carrier receptor proteins (CRP) have been isolated from the sera of penicillin allergic rabbits and human subjects in the unconjugated native state in electrophoretically homogeneous form by employing a synthetic polymeric affinity template containing the 7-deoxy analogue of penicillin G. The synthesis of the 7-deoxy analogue has been described. In this affinity system the antipenicillin-antibody is desorbed by 0·9M thiourea and the CRP in 8M urea. The CRP after incubation with penicillin is converted into the full-fledged antigen. Studies on the origin of CRP and the nature of antibody as well as comparative studies on the properties of the rabbit antibody and those of antibodies elicited by a BSA-BPO conjugate are reported.

Isolation and characterization of heat-stable allergens from shrimp (Penaeus indicus)

Shrimp are among the more common causes of immediate hypersensitivity reactions to food. To characterize better the allergenic substances within shrimp, extracts from heated shrimp were systematically examined with solid-phase radioimmunoassay and sera from patients clinically sensitive to shrimp. Two heat-stable protein allergens, designated as Sa-I and Sa-II, were identified from boiled shrimp (Penaeus indicus) extracts. Sa-I was isolated by ultrafiltration, Sephadex G-25, and diethylaminoethyl-Sephacel chromatography, whereas Sa-II, the major allergen, was purified by successive chromatography on diethylaminoethyl-Sephacel, Bio-Gel P-200, and Sepharose 4B columns. Sa-I, which was homogeneous by polyacrylamide gel electrophoresis (PAGE), elicited a single band on sodium dodecyl sulfate-PAGE corresponding to a molecular weight of 8.2 kd. Sa-II was also found to be homogeneous by PAGE, crossed immunoelectrophoresis, and immunoblotting. On sodium dodecyl sulfate-PAGE, it elicited a single band with a molecular weight of 34 kd. Sa-II was found to contain 301 amino acid residues and was particularly rich in glutamate/glutamine and aspartate/asparagine. Solid-phase radioimmunoassay-inhibition studies revealed that Sa-I and Sa-II share 54% of the allergenic epitopes, suggesting that Sa-I may be a fragment of Sa-II.SDS-PAGE, Sodium dodecyl sulfate-polyacrylamide gel electrophoresis; MW, Molecular weight; BSA, Bovine serum albumin; DEAE, Diethylaminoethyl; SPRIA, Solid-phase radioimmunoassay; CIE, Crossed immunoelectrophoresis .

The role of inflammation and matrix proteins in airway remodelling

Asthma is a chronic inflammatory disorder of the airways. Remodelling in asthma is defined as the structural changes seen in the airways of asthmatics in comparison to healthy controls. Progressive loss of lung function also seen in asthma might be caused by remodelling. The research aims of this thesis were to investigate inflammation and remodelling in the airways of different types of asthmatics and smokers. The association between inflammation and remodelling was also examined in a mouse model of allergic airway inflammation. Healthy smokers showed increased numbers of macrophages in the BAL with no changes in the inflammatory cells in biopsies. Macrophages seemed to be quite quiescent, since mRNA expression for a wide variety of inflammatory mediators, especially chemokines CCL3, CCL4, CCL5 and CCL20, secreted by macrophages was significantly lower than in healthy non-smokers. Attenuated macrophage activity in the airway lumen may render smokers more susceptible to airway infections and have an impact on the development of other airway pathology. Patients with diisocyanate-induced asthma (DIA) on inhaled corticosteroids (ICS) who still had non-specific bronchial hyperreactivity (NSBHR) at the end of the follow-up showed increased expression of TNF-α, IL-6 and IL-15 mRNA in BAL cells compared to those without NSBHR. In addition to being markers for poor prognosis and possible slight glucocorticoid resistance, these cytokines might aid in guiding the treatment of DIA. The increase in the thickness of tenascin-C layer in the bronchial basement membrane (BM) was much less than usually seen in other types of asthma, which might not make tenascin-C a good marker for DIA. OVA-induced tenascin-C expression in the lung was attenuated in STAT4-/- mice with impaired Th1-type immunity compared to WT mice. Interestingly, STAT6-/- mice with impaired Th2-type immunity showed tenascin-C expression levels similar to those of WT mice. The clearest difference between these two knockout strains in response to OVA was that STAT4-/- mice exhibited no upregulation of IFN-γ and TNF-α mRNA expression. Thus, tenascin-C expression was unexpectedly more related to Th1 type reactions. In vitro studies confirmed the results. Human fibroblasts stimulated by TNF-α and IFN-γ showed increased expression of tenascin-C. Patients with newly diagnosed asthma showed increased expression of laminin α2 in the bronchial BM in comparison to patients with asthma symptoms only and healthy controls. Both patients with asthma and those with only asthma symptoms showed increased expression of the laminin β2 chain in comparison to controls. Thus, laminin α2 expression differentiated patients with clinical asthma from patients with symptoms only. Furthermore, the expression of laminin α2 and β2 was associated with NSBHR, linking very specific remodelling events to clinical findings.

Antimicrobial activity of highly stable silver nano particles embedded in agar-agar matrix as a thin film

Highly stable silver nanoparticles (Ag NPs) in agar-agar (Ag/agar) as inorganic-organic hybrid were obtained as free-standing film by in situ reduction of silver nitrate by ethanol. The antimicrobial activity of Ag/agar film on Escherichia coli (E. coil), Staphylococcus aureus (S. aureus), and Candida albicans (C albicans) was evaluated in a nutrient broth and also in saline solution. In particular, films were repeatedly tested for antimicrobial activity after recycling. UV-vis absorption and TEM studies were carried out on films at different stages and morphological studies on microbes were carried out by SEM. Results showed spherical Ag NPs of size 15-25 nm, having sharp surface plasmon resonance (SPR) band. The antimicrobial activity of Ag/agar film was found to be in the order, C. albicans > E. coil > S. aureus, and antimicrobial activity against C. albicans was almost maintained even after the third cycle. Whereas, in case of E. coil and S. aureus there was a sharp decline in antimicrobial activity after the second cycle. Agglomeration of Ag NPs in Ag/agar film on exposure to microbes was observed by TEM studies. Cytotoxic experiments carried out on HeLa cells showed a threshold Ag NPs concentration of 60 mu g/mL, much higher than the minimum inhibition concentration of Ag NPs (25.8 mu g/mL) for E. coli. The mechanical strength of the film determined by nanoindentation technique showed almost retention of the strength even after repeated cycle. (C) 2010 Elsevier Ltd. All rights reserved.

Berry phenolics: isolation, analysis, identification, and antioxidant properties

The main objectives in this thesis were to isolate and identify the phenolic compounds in wild (Sorbus aucuparia) and cultivated rowanberries, European cranberries (Vaccinium microcarpon), lingonberries (Vaccinium vitis-idaea), and cloudberries (Rubus chamaemorus), as well as to investigate the antioxidant activity of phenolics occurring in berries in food oxidation models. In addition, the storage stability of cloudberry ellagitannin isolate was studied. In wild and cultivated rowanberries, the main phenolic compounds were chlorogenic acids and neochlorogenic acids with increasing anthocyanin content depending on the crossing partners. The proanthocyanidin contents of cranberries and lingonberries were investigated, revealing that the lingonberry contained more rare A-type dimers than the European cranberry. The liquid chromatography mass spectrometry (LC-MS) analysis of cloudberry ellagitannins showed that trimeric lambertianin C and sanguiin H-10 were the main ellagitannins. The berries, rich in different types of phenolic compounds including hydroxycinnamic acids, proanthocyanidins, and ellagitannins, showed antioxidant activity toward lipid oxidation in liposome and emulsion oxidation models. All the different rowanberry cultivars prevented lipid oxidation in the same way, in spite of the differences in their phenolic composition. In terms of liposomes, rowanberries were slightly more effective antioxidants than cranberry and lingonberry phenolics. Greater differences were found when comparing proanthocyanidin fractions. Proanthocyanidin dimers and trimers of both cranberries and lingonberries were most potent in inhibiting lipid oxidation. Antioxidant activities and antiradical capacities were also studied with hydroxycinnamic acid glycosides. The sinapic acid derivatives of the hydroxycinnamic acid glycosides were the most effective at preventing lipid oxidation in emulsions and liposomes and scavenging radicals in DPPH assay. In liposomes and emulsions, the formation of the secondary oxidation product, hexanal, was inhibited more than that of the primary oxidation product, conjugated diene hydroperoxides, by hydroxycinnamic acid derivatives. This indicates that they are principally chain-breaking antioxidants rather than metal chelators, although they possess chelating activity as well. The storage stability test of cloudberry ellagitannins was performed by storing ellagitannin isolate and ellagitannins encapsulated with maltodextrin at different relative vapor pressures. The storage stability was enhanced by the encapsulation when higher molecular weight maltodextrin was used. The best preservation was achieved when the capsules were stored at 0 or 33% relative vapor pressures. In addition, the antioxidant activities of encapsulated cloudberry extracts were followed during the storage period. Different storage conditions did not alter the antioxidant activity, even though changes in the ellagitannin contents were seen. The current results may be of use in improving the oxidative stability of food products by using berries as natural antioxidants.

Design of nonequivalent self-routing networks based on a matrix model

In earlier work, nonisomorphic graphs have been converted into networks to realize Multistage Interconnection networks, which are topologically nonequivalent to the Baseline network. The drawback of this technique is that these nonequivalent networks are not guaranteed to be self-routing, because each node in the graph model can be replaced by a (2 × 2) switch in any one of the four different configurations. Hence, the problem of routing in these networks remains unsolved. Moreover, nonisomorphic graphs were obtained by interconnecting bipartite loops in a heuristic manner; the heuristic nature of this procedure makes it difficult to guarantee full connectivity in large networks. We solve these problems through a direct approach, in which a matrix model for self-routing networks is developed. An example is given to show that this model encompases nonequivalent self-routing networks. This approach has the additional advantage in that the matrix model itself ensures full connectivity.

Heterogeneous nucleation of solidification of cadmium particles embedded in an aluminium matrix

A hypomonotectic alloy of Al-4.5wt%Cd has been manufactured by melt spinning and the resulting microstructure examined by transmission electron microscopy. As-melt spun hypomonotectic Al-4.5wt%Cd consists of a homogeneous distribution of faceted 5 to 120 nm diameter cadmium particles embedded in a matrix of aluminium, formed during the monotectic solidification reaction. The cadmium particles exhibit an orientation relationship with the aluminium matrix of {111}Al//{0001}Cd and lang110rangAlAl//lang11¯20> Cd, with four cadmium particle variants depending upon which of the four {111}Al planes is parallel to {0001}Cd. The cadmium particles exibit a distorted cuboctahedral shape, bounded by six curved {100}Al//{20¯23}Cd facets, six curved {111}Al/{40¯43}Cd facets and two flat {111}Al//{0001}Cd facets. The as-melt spun cadmium particle shape is metastable and the cadmium particles equilibrate during heat treatment below the cadmium melting point, becoming elongated to increase the surface area and decrease the separation of the {111}Al//{0001}Cd facets. The equilibrium cadmium particle shape and, therefore, the anisotropy of solid aluminium-solid cadmium and solid aluminium -liquid cadmium surface energies have been monitored by in situ heating in the transmission electron microscope over the temperature range between room temperature and 420 °C. The anisotropy of solid aluminium-solid cadmium surface energy is constant between room temperature and the cadmium melting point, with the {100}Al//{20¯23}Cd surface energy on average 40% greater than the {111}Al//{0001}Cd surface energy, and 10% greater than the {111}Al//{40¯43Cd surface energy. When the cadmium particles melt at temperatures above 321 °C, the {100}Al//{20¯23}Cd facets disappear and the {111}Al//{40¯43}Cd and {111}A1//{0001}Cd surface energies become equal. The {111}Al facets do not disappear when the cadmium particles melt, and the anisotropy of solid aluminium-liquid cadmium surface energy decreases gradually with increasing temperature above the cadmium melting point. The kinetics of cadmium solidification have been examined by heating and cooling experiments in a differential scanning calorimeter over a range of heating and cooling rates. Cadmium particle solidification is nucleated catalytically by the surrounding aluminium matrix on the {111}Al faceted surfaces, with an undercooling of 56 K and a contact angle of 42 °. The nucleation kinetics of cadmium particle solidification are in good agreement with the hemispherical cap model of heterogeneous nucleation.