Realtime kinetic analysis of antigen-antibody interaction using solid phase binding: Transformation of hCG-monoclonal antibody complex

Kinetic constants of MAb-hCG interactions have been determined using solid phase binding of I-125[hCG] to immobilized MAb. While association has been shown to follow the expected pattern, dissociation consists of at least two reversible steps, one with a rate constant of 0.0025 min(-1), and a second with a rate constant of 0.00023 min(-1). Validity of affinity constant measurements in the light of the complex reaction kinetics is discussed, A comparison between the method of surface plasmon resonance technology (BIAcore) and solid phase binding (SPB) for determination of kinetic parameters shows that SPB provides not only a cost-effective approach for determination of realtime kinetic parameters of macromolecular ligand-ligate interaction but also a method with several advantages over the BIAcore system in investigating the mechanism of antigen-antibody interaction.

Further studies on Norrish type II reactions including a reaction in the first excited singlet state and cyclization of 1:4 biradicals

The Norrish type II processes of methyl-2,2-dimethyl- cyclopropyl ketone, alpha-alkoxy acetones and alkyl pyruvates have been examined using the AM1 semi-empirical molecular orbital method with complete geometry optimization at the partial configuration interaction level in the restricted Hartree-Fock (RHF) frame. The results reveal that the methyl-substituted cyclopropyl ketone has a constrained geometry favourable for hydrogen abstraction from the gamma-position relative to the carbonyl group in the excited singlet state. The presence of the ether oxygen atom in the beta-position relative to the carbonyl group in alkoxy acetones and alkyl pyruvates leads to increased reactivity relative to alkyl monoketones and diketones respectively. The cyclization of 1:4 biradicals has been studied in the unrestricted Hartree-Fock (UHF) frame, and the results reveal that the 1:4 biradical derived from alkoxy acetones readily cyclizes to form oxetanols. On the other hand, in the 1:4 biradicals derived from methyl-substituted cyclopropyl ketone, the three-membered ring breaks readily to form an enol intermediate. Delocalization of an odd electron in 1:4 biradicals derived from alkyl pyruvates is thought to make cyclization difficult.

Thermo and photoluminescence properties of Eu3+ activated hexagonal, monoclinic and cubic gadolinium oxide nanorods

Different phases of Eu3+ activated gadolinium oxide (Gd (OH)(3), GdOOH and Gd2O3) nanorods have been prepared by the hydrothermal method with and without cityl trimethyl ammonium bromide (GAB) surfactant. Cubic Gd2O3:Eu (8 mol%) red phosphor has been prepared by the dehydration of corresponding hydroxide Gd(OH)(3):Eu after calcinations at 350 and 600 degrees C for 3 h, respectively. When Eu3+ ions were introduced into Gd(OH)(3), lattice sites which replace the original Gd3+ ions, a strong red emission centered at 613 nm has been observed upon UV illumination, due to the intrinsic Eu3+ transition between D-5(0) and F-7 configurations. Thermoluminescence glow curves of Gd (OH)(3): Eu and Gd2O3:Eu phosphors have been recorded by irradiating with gamma source ((CO)-C-60) in the dose range 10-60 Gy at a heating rate of 6.7 degrees C sec(-1). Well resolved glow peaks in the range 42-45, 67-76,95-103 and 102-125 degrees C were observed. When gamma-irradiation dose increased to 40 Gy, the glow peaks were reduced and with increase in gamma-dose (50 and 60 Gy) results the shift in first two glow peak temperatures at about 20 degrees C and a new shouldered peak at 86 degrees C was observed. It is observed that there is a shift in glow peak temperatures and variation in intensity, which is mainly attributed to different phases of gadolinium oxide. The trapping parameters namely activation energy (E), order of kinetics (b) and frequency factor were calculated using peak shape and the results are discussed. (C) 2010 Elsevier B.V. All rights reserved.

Organometallic chemistry of diphosphazanes. Rhodium(I) complexes of RN(PX2)2 (R = C6H5; X = OC6H5, OC6H4Br?p, R = CH3; X = OC6H5)

Reactions of [Rh(COD)Cl](2) with the ligand RN(PX(2))(2) (1: R=C6H5; X=OC6H5) give mono- or disubstituted complexes of the type [Rh-2(COD)Cl-2{eta(2)-C6H5N(P(OC6H5)(2))(2)}-] or [RhCl{eta(2)-C6H5N(P(OC6H5)(2))(2)}](2), depending on the reaction conditions. Reaction of 1 with [Rh(CO)(2)Cl](2) gives the symmetric binuclear complex, [Rh(CO)Cl{mu-C6H5N(P(OC6H5)(2))(2)}], whereas the same reaction with 2 (R=CH3; X=OC6H5) leads to the formation of an asymmetric complex of the type [Rh(CO)(mu-CO)Cl{mu-CH3N(P(OC6H5)(2))(2)}] containing both terminal and bridging CO groups. Interestingly the reaction of 3 (R=C6H5, X = OC6H4Br-p) with either [Rh(COD)Cl](2) or [Rh(CO)(2)Cl](2) leads only to the formation of the chlorine bridged binuclear complex, [RhCl{eta(2)-C6H5N(P(OC6H4Br-p)(2))(2)}](2). The structural elucidation of the complexes was carried out by elemental analyses, IR and P-31 NMR spectroscopic data.

ChemInform Abstract: Synthesis Based on Cyclohexadienes. Part 16. Synthesis of Methyl 2,7-Dimethyltricyclo (5.2.2.01,5)undec-5-ene-6-carboxylates

Synthesis of methyl 2, 7-dimethyltricyclo{5.2.2.0(1,5}undec-5-en-6-carboxylates, the tricyclic skeleton present in (+)-allo-cedrol (1) is described using the Diels-Alder strategy. Thus, Birch reduction of the aromatic acid 8 gives 5, the methyl ester of which is isomerised with DBU to a 1:1 mixture of the dienes 6 and 4. Cycloaddition of this mixture with 2-chloroacrylonitrile followed by hydrolysis yields the ketone 60 having the tricyclo{5.2.2.0(1.5)}undec-5-ene framework. Similar reaction with methyl vinyl ketone affords the regioisomeric adducts 61 and 62.

Mean-field theory of charge ordering and phase transitions in the colossal-magnetoresistive manganites

We study phase transitions in the colossal-magnetoresistive manganites by using a mean-field theory both at zero and non-zero temperatures. Our Hamiltonian includes double-exchange, superexchange, and Hubbard terms with on-site and nearest-neighbour Coulomb interaction, with the parameters estimated from earlier density-functional calculations. The phase diagrams show magnetic and charge-ordered (or charge-disordered) phases as a result of the competition between the double-exchange, superexchange, and Hubbard terms, the relative effects of which are sensitively dependent on parameters such as doping, bandwidth, and temperature. In accord with the experimental observations, several important features are reproduced from our model, namely, (i) a phase transition from an insulating, charge-ordered antiferromagnetic to a metallic, charge-disordered ferromagnetic state near dopant concentration x = 1/2, (ii) the reduction of the transition temperature TAF-->F by the application of a magnetic field, (iii) melting of the charge order by a magnetic field, and (iv) phase coexistence for certain values of temperature and doping. An important feature, not reproduced in our model, is the antiferromagnetism in the electron-doped systems, e.g., La1-xCaxMnO3 over the entire range of 0.5 less than or equal to x less than or equal to 1, and we suggest that a multi-band model which includes the unoccupied t(2g) orbitals might be an important ingredient for describing this feature.

Icosahedral quasicrystalline and hexagonal approximant phases in the Al-Mn-Be alloy system

We report the formation of a primitive icosahedral quasicrystal with increased stability in Al Mn-Be alloys close to the compound Al15Mn13Be2, by melt spinning and injection casting. The crystal structure of this compound was unknown. We show that in as-cast as well as heat treated condition the intermetallic phase H1 has a hexagonal structure with lattice parameters a = 1.2295 run and c = 2.4634 nm. The space group is P6(3)/mmc In the injection-cast samples, the quasicrystal coexists with another closely related hexagonal phase H2 with a = 1.2295 nm and c = 1.2317 nm with a possible space group of P6/mmm. This phase exhibits specific orientation relationships with the icosahedral quasicrystal given by [0001](hex)//2f(QC) and [01 (1) over bar0](hex)//5f(QC) where 2f(QC) and 5f(QC) represent twofold and fivefold axes respectively. Electron diffraction patterns from both phases exhibit a close resemblance to the quasicrystalline phase. It is shown that the H1 phase is closely related to mu-Al4Mn with the same e parameter while the a parameter is reduced by tau. Following Kreiner and Franzen, it is postulated that both structures (H1 and H2) can be understood by a simple hexagonal packing of I13 clusters.

Role of length scales on microwave thawing dynamics in 2D cylinders

Microwave (MW) thawing of 2D frozen cylinders exposed to uniform plane waves from one face, is modeled using the effective heat capacity formulation with the MW power obtained from the electric field equations. Computations are illustrated for tylose (23% methyl cellulose gel) which melts over a range of temperatures giving rise to a mushy zone. Within the mushy region the dielectric properties are functions of the liquid volume fraction. The resulting coupled, time dependent non-linear equations are solved using the Galerkin finite element method with a fixed mesh. Our method efficiently captures the multiple connected thawed domains that arise due to the penetration of MWs in the sample. For a cylinder of diameter D, the two length scales that control the thawing dynamics are D/D-p and D/lambda(m), where D-p and lambda(m) are the penetration depth and wavelength of radiation in the sample respectively. For D/D-p, D/lambda(m) much less than 1 power absorption is uniform and thawing occurs almost simultaneously across the sample (Regime I). For D/D-p much greater than 1 thawing is seen to occur from the incident face, since the power decays exponentially into the sample (Regime III). At intermediate values, 0.2 < D/D-p, D/lambda(m) < 2.0 (Regime II) thawing occurs from the unexposed face at smaller diameters, from both faces at intermediate diameters and from the exposed and central regions at larger diameters. Average power absorption during thawing indicates a monotonic rise in Regime I and a monotonic decrease in Regime III. Local maxima in the average power observed for samples in Regime II are due to internal resonances within the sample. Thawing time increases monotonically with sample diameter and temperature gradients in the sample generally increase from Regime I to Regime III. (C) 2002 Elsevier Science Ltd. All rights reserved.

Aromatic, microporous polymer networks with high surface area generated in Friedel-Crafts-type polycondensations

A series of novel, microporous polymer networks (MPNs) have been generated in a simple, acid catalysed Friedel-Crafts-type self-condensation of A(2)B(2)- and A(2)B(4)-type fluorenone monomers. Two A2B4-type monomers with 2,7-bis(N, N-diphenylamino) A or 2,7-bis [4-(N, N-diphenylamino) phenyl] D substitution of the fluorenone cores lead to MPNs with high S(BET) surface areas of up to 1400 m(2) g(-1). Two MPNs made of binary monomer mixtures showed the highest Brunauer-Emmett-Teller (BET) surface areas S(BET) of our series (SBET of up to 1800 m(2) g(-1)) after washing the powdery samples with supercritical carbon dioxide. Total pore volumes of up to 1.6 cm(3) g(-1) have been detected. It is observed that the substitution pattern of the monomers is strongly influencing the resulting physicochemical properties of the microporous polymer networks (MPNs).

Spectral Finite Element Modeling of Complex Structures for Applications in Real-time Structural Health Monitoring

In this paper we discuss the recent progresses in spectral finite element modeling of complex structures and its application in real-time structural health monitoring system based on sensor-actuator network and near real-time computation of Damage Force Indicator (DFI) vector. A waveguide network formalism is developed by mapping the original variational problem into the variational problem involving product spaces of 1D waveguides. Numerical convergence is studied using a h()-refinement scheme, where is the wavelength of interest. Computational issues towards successful implementation of this method with SHM system are discussed.

Antihyperlipidemic potential of Cedrus deodara extracts in monosodium glutamate induced obesity in neonatal rats

Objective: To study the antihyperlipidemic effect of Cedrus deodara (C. deodara) against monosodium glutamate (MSG) induced obesity in neonatal rats. Materials and Methods: The studies were carried out on newborn neonatal rats and were injected intraperitoneally with 2 mg/g of MSG on the 2(nd) and 4(th) postnatal days and 4 mg/g on 6(th), 8(th) and 10(th) postnatal days. Ethanolic extract (EE) and acetone extract (AE) of C. deodara was administered in a dose of 100 and 200 mg/kg, p.o./day at the age of 65 days. On day 60 of treatment, body weight, locomotor activity, body temperature, and various biochemical parameters like serum glucose, total cholesterol, triglyceride, and organs weights were recorded. Results: There was a significant reduction in body weight, organs and increased body temperature, locomotor activity after treatment with extracts. C. deodara decreased serum glucose, total cholesterol and triglyceride, low density lipoprotein (LDL) and very low density lipoprotein (VLDL) levels and increased high density lipoprotein (HDL) significantly has compared to MSG-control rats. Conclusion: C. deodara extracts exhibited antihyperlipidemic effect and it possesses anti-obesity properties in MSG induced obese rats.

Sampling disturbances of soft sensitive clays

Sampling disturbance is unavoidable and hence the laboratory testing most often is on partially disturbed samples. This paper deals with the development of a simple method to assess degree of sample disturbance from the prediction of yield stress due to cementation and comparison of yield stress in compression of partially disturbed sample with reference to a predicted compression path of the clay devoid of any mechanical disturbance. The method uses simple parameters which are normally determined in routine investigations.

Self-assembly of Ru-4 and Ru-8 assemblies by coordination using organometallic Ru(II)(2) precursors: Synthesis, characterization and properties

Coordination-driven self-assembly of binuclear half-sandwich p-cymene ruthenium(II) complexes [Ru-2(mu-eta(4)-C2O4)(MeOH)(2)(eta(6)-p-cymene)(2)](O3SCF3)(2) (1a) or [Ru-2(mu-eta(4)-N,N'-diphenyloxamidato)(MeOH)(2)(eta(6)-p-cymene)(2)]( O3SCF3)(2) (1b) separately with an imidazole-based tetratopic donor L in methanol affords two tetranuclear metallamacrocycles 2a and 2b, respectively. Conversely, the similar combination of L with 2,5-dihydroxy-1,4-benzoquinonato (dhbq) bridged binuclear complex [Ru-2(mu-eta(C6H2O4)-C-4)(MeOH)(2)(eta(6)-p-cymene)(2)](O3SCF3)(2) (1c) in 1:2 molar ratio resulted in an octanuclear macrocyclic cage 2c. All the self-assembled macrocycles 2a-2c were isolated as their triflate salts in high yields and were characterized fully by multinuclear (H-1, C-13 and F-19) NMR, infrared (IR) and electrospray ionization mass spectrometry (ESIMS). In addition, the molecular structure of macrocycle 2a was established unequivocally by single-crystal X-ray diffraction analysis and adopts a tetranuclear rectangular geometry with the dimensions of 5.53 angstrom x 12.39 angstrom. Furthermore, the photo-and electrochemical properties of these newly synthesized assemblies have been studied by using UV-vis absorption and cyclic voltammetry analysis.

Location Area Planning Using Simulated Annealing With A New Solution Representation

Location area planning problem is to partition the cellular/mobile network into location areas with the objective of minimizing the total cost. This partitioning problem is a difficult combinatorial optimization problem. In this paper, we use the simulated annealing with a new solution representation. In our method, we can automatically generate different number of location areas using Compact Index (CI) to obtain the optimal/best partitions. We compare the results obtained in our method with the earlier results available in literature. We show that our methodology is able to perform better than earlier methods.

Sm(III)nitrate-catalyzed one-pot synthesis of furano3,2c]-1,2,3,4-tetrahydroquinolines and DNA photocleavage studies

The synthesis and DNA photocleavage studies of furano3,2-c]-1,2,3,4-tetrahydroquinolines have been reported. Sm(III)nitrate was found to be an efficient for the Diels-Alder reaction of aryl amines with 2,3-dihydrofuran to offer the corresponding furano3,2-c]-1,2,3,4-tetrahydroquinolines derivatives as a mixture of cis/trans stereoisomers in moderate yields. The aqueous solubility of acid catalyst can be recycled without significant loss of activity. The DNA photocleavage studies shows that, the cis/trans stereoisomers are good DNA cleavage mimic in terms of molecular structure. (C) 2012 Elsevier B.V. All rights reserved.