Functions In Cn Research Articles

Self‐Assembly of Spheroidal Structures: The Coordination Chemistry of Pentacyanocyclopentadienide

AbstractModelling studies show that the anion pentacyanocyclopentadienide, 1, can complex linearly coordinating cations such as silver(I) and copper(I) to form a spheroidal complex [M30(1)12]18+ with minimum distortion. The anion 1 complexes transition metal ions to give species which appear to be polymers in the solid state. The structure of Ag(1) was determined by powder diffraction and shows a one‐dimensional polymeric structure with three coordinate AgI and two CN functions of the ligand 1 non‐coordinated. No evidence for the formation of the spheroidal complex was found.

The Role of Methionine Oxidation/Reduction in the Regulation of Immune Response

Methionine oxidation by reactive oxygen species and reduction mediated by the methionine sulfoxide reductase (Msr) system may attenuate protein function in signal transduction pathways. This review will focus on two potential protein targets for methionine oxidation involved in signal transduction of the immune response: Ca(2+)/calmodulin-regulated phosphatase calcineurin (Cn) and inhibitor of kappa B-alpha (IkBα). The major known function of Cn is to regulate nuclear localization of the nuclear factor of activated T cells (NFAT), a family of transcription factors during immune stimulus. Like wise, IκBα inhibits the activity of nuclear factor kappa B (NFkB), which is known to regulate the transcription of various genes participating in immunological and oxidative stress response. Modification of Met (45) in IκBα enhances its resistance to protein-degredation; thereby, preventing NFkB from activating transcription in cells of the immune system. Similarly, the human Cn molecule contains several methionine residues that are either located next to a cysteine residue or a methionine residue. Accordingly, it is suggested that oxidation of a specific Cn-methionine may interfere with the proper NFAT nuclear-localization and transcriptional activation in T-cell. Thus, the roles of oxidized-methionine residues and their reduction, by the Msr system, are discussed as potential regulators of cellular immune response.

Representation formula for the critical points of the Tadjbakhsh-Odeh functional and its application

In order to study the buckled states of an elastic ring under uniform pressure, Tadjbakhsh and Odeh [14] introduced an energy functional which is a linear combination of the total squared curvature (elastic energy) and the area enclosed by the ring. We prove that the minimizer of the functional is not a disk when the pressure is large, and its curvature can be expressed by Jacobian elliptic cn(·) function. Moreover, the uniqueness of the minimizer is proven for certain range of the pressure.

On the weighted space of entire functions in ℂ n

In terms of the Laplace transform, we give a description of the dual space to the weighted space of entire functions in ℂn for the case in which the weight functions have polynomial growth.

Chemical processes in the atmospheric pressure plasma treatment of benzene

In this paper, we present the first multi-diagnostic investigation of the chemical processes occurring in nitrogen–benzene plasmas at atmospheric pressure. Plasma treatment results in extended deposit formation on the reactor surfaces. In our experiment, the composition of the deposit has been investigated by several well established analytical techniques (NMR, FT-IR, and GC-MS). The most abundant molecule synthesized in the plasma turns out to be biphenyl, while the polymeric, tholin-like, fraction of the deposit show the presence of CN, NH and NH2 functions. To get further insights on the characteristics of the discharge, optical emission spectra have also been recorded and studied.

Nodal Sets of Harmonic Functions

If u is a homogenous harmonic polynomial, its frequency is exactly its degree. In general, the frequency controls the growth of the harmonic functions. In the present lecture notes, we shall discuss how the frequency controls the size of nodal sets. As we know, plane harmonic functions are simply the real parts of holomorphic functions in the complex plane. This simple identification is not enjoyed by harmonic functions in higher dimensional spaces. However, harmonic functions in Rn, as analytic functions with interior estimates on derivatives, can be extended as holomorphic functions in Cn. It turns out that such an extension is extremely important in the discussion of nodal sets of harmonic functions. This is because the nodal sets of (general analytic) functions in Rn are not stable in the sense that a simple perturbation may change the structure of nodal sets. In particular, the dimension of nodal sets may change by perturbations. However, this never happens for holomorphic functions in Cn. In order to discuss nodal sets of harmonic functions, we shall first discuss complex nodal sets of the holomorphic extensions. It is not surprising that complex analysis plays an important role in our study. For example, we shall use repeatedly Rouche Theorem in C and in C2. It asserts that if an equidimensional holomorphic map has isolated zeroes then its holomorphic perturbation enjoys the same property and the number of isolated zeroes is preserved. Another property we shall use is the behavior of polynomials away from their zeroes. For a suitably normalized polynomial, a positive lower bound can be established for the modulus of the polynomial outside some balls around its zeroes. The foundation of our discussion is a monotonicity formula for harmonic functions. Corollaries of such a monotonicity include the doubling condition of L2-integrals and finite vanishing order. In fact, an integral quantity of harmonic functions in the unit ball controls the vanishing order of harmonic functions inside the ball.

Screening of α-helical peptide ligands controlling a calcineurin-phosphatase activity

In this paper, we describe an application of 202-membered fluorescently labeled peptide library designed to take an α-helix secondary structure. As a proof-of-concept experiment, a calmodulin (CaM)/calcineurin (Cn) pair was chosen to screen α-helical peptide ligands that tightly bind to CaM and also control enzymatic functions of Cn. Three peptides were successfully selected from the library by assaying Cn-phosphatase activities and peptide–CaM interactions (dual check process). The strategy using a designed peptide library shows real promise as a peptide-based high-throughput screening system.

Nanoclustered palladium(0) supported on a gel-type poly-acrylonitrile– N, N-dimethylacrylamide–ethylenedimethacrylate resin: Nanostructural aspects and catalytic behaviour

Gel-type resin poly-acrylonitrile (30 mol%)– N, N-dimethylacrylamide (66 mol%)–ethylenedimethacrylate (4 mol%) (ADE) is obtained in very high yield with γ-rays-sustained polymerisation in mass. Water-swollen ADE microparticles react readily with [PdCl 4 2−] in water to give a macromolecular complex likely to be ▪. The material undergoes facile reduction to a Pd 0/ADE nanocomposite, in which a surprisingly non-homogeneous distribution of Pd 0 nanoclusters suggests a remarkable inhomogeneity in the distribution of the –CN groups through the polymer framework. This circumstance is attributed to a marked occurrence of a block-type polymerisation of the acrylonitrile leading to spheroidal domains that are particularly rich in –CN functionalities. Pd 0/ADE appears to be an active, re-usable, mechanically and chemically stable catalyst in the model hydrogenation reaction of cyclohexene in methanol under moderate conditions, carried out in batch reactors.

Surface reactions during etching of organic low-k films by plasmas of N2 and H2

Surface reactions during etching of organic low-k film by N2 and H2 plasmas were studied through observations of the surface resident species using in situ infrared spectroscopy and in vacuo electron-spin-resonance techniques. We observed surface modifications by the formation of CN and NH bonds after exposure to plasmas generated from N2 and H2. The number of carbon dangling bonds were greater in processes where H2 was present. The passivation of carbon dangling bonds leads to CH3, NH3, and CN functionalities, which are the precursors for etching products that are desorbed, which includes volatile forms such as HCN and C2N2.

Robustness and modular design of the Drosophila segment polarity network

Biomolecular networks have to perform their functions robustly. A robust function may have preferences in the topological structures of the underlying network. We carried out an exhaustive computational analysis on network topologies in relation to a patterning function in Drosophila embryogenesis. We found that whereas the vast majority of topologies can either not perform the required function or only do so very fragilely, a small fraction of topologies emerges as particularly robust for the function. The topology adopted by Drosophila, that of the segment polarity network, is a top ranking one among all topologies with no direct autoregulation. Furthermore, we found that all robust topologies are modular—each being a combination of three kinds of modules. These modules can be traced back to three subfunctions of the patterning function, and their combinations provide a combinatorial variability for the robust topologies. Our results suggest that the requirement of functional robustness drastically reduces the choices of viable topology to a limited set of modular combinations among which nature optimizes its choice under evolutionary and other biological constraints.

Plasmodium falciparum calcineurin and its association with heat shock protein 90: mechanisms for the antimalarial activity of cyclosporin A and synergism with geldanamycin

Geldanamycin (GA), an antibiotic of the ansamycin family and an inhibitor of heat shock protein 90 (Hsp90), was previously shown to inhibit the malarial parasite, Plasmodium falciparum. Here we report that cyclosporin A (CsA), an inhibitor of parasitic cyclophilin (Cyp) and protein phosphatase 2B (calcineurin, CN), acted synergistically with GA to inhibit the erythrocytic growth of the parasite. Parasitic calcineurin associated with Hsp90 in vivo, and GA inhibited the association, but CsA had no effect. In a number of CsA-resistant (CsA R) P. falciparum clones mutations were detected in functionally significant amino acid residues of the catalytic and regulatory subunits of calcineurin (CnA and CnB, respectively) and in two out of three parasitic cyclophilins, namely Cyp19A and Cyp19B. No mutation was detected in the third cyclophilin, Cyp24. Further analysis of the mutant CnA revealed that its protein phosphatase activity was highly CsA-resistant in vitro. Similarly, one of the mutant Cyp19A proteins was purified and found to be unable to inhibit parasitic CN in the presence of CsA. Together, these results underscore the importance of the proper assembly and function of CN in plasmodial biology and suggest that the inhibition of CN can be a potential mechanism behind the CsA-sensitivity of the malaria parasite.

Cyclosporin A inhibits calcineurin (phosphatase 2B) and P-glycoprotein activity in Entamoeba histolytica

Cyclosporin A (CsA) inhibits the proliferation of several protozoan parasites through blocking the activity of calcineurin (Cn) or P-glycoproteins (Pgp). We report here, that inhibition of the proliferation of Entamoeba histolytica trophozoites, the causal agent of human amebiasis, is due to interference of the phosphatase activity of Cn, in a similar fashion to the effect of this immunosuppressive drug on T lymphocytes. The non-immunosuppressive CsA analog PSC-833, which binds Pgp without interfering the function of Cn, did not inhibit the proliferation of HM1:IMSS trophozoites. Moreover, phosphatase activity of amebic Cn, detected using the phosphopeptide RII, was drastically affected by incubation with CsA, but not with PSC-833. On the other hand, both drugs were also tested on clone C2 trophozoites, which grow in the presence of emetine due to over-expression of Pgp. The effect of CsA was similar to that observed on HM1:IMSS trophozoites, whereas PSC-833 only affected the proliferation and viability of clone C2 when the trophozoites were grown in the presence of 40 μM of emetine, suggesting an interference of the Pgp activity. This suggestion was confirmed by results from experiments of Pgp-dependent effux of rhodamine from pre-loaded trophozoites, in the presence of either of these drugs. Therefore, CsA inhibition of E. histolytica trophozoite proliferation is more likely due to Cn than Pgp activity inhibition.

Symbolic computation of exact solutions expressible in hyperbolic and elliptic functions for nonlinear PDEs

Algorithms are presented for the tanh- and sech-methods, which lead to closed-form solutions of nonlinear ordinary and partial differential equations (ODEs and PDEs). New algorithms are given to find exact polynomial solutions of ODEs and PDEs in terms of Jacobi’s elliptic functions. For systems with parameters, the algorithms determine the conditions on the parameters so that the differential equations admit polynomial solutions in tanh, sech, combinations thereof, Jacobi’s sn or cn functions. Examples illustrate key steps of the algorithms. The new algorithms are implemented in Mathematica. The package PDESpecialSolutions.m can be used to automatically compute new special solutions of nonlinear PDEs. Use of the package, implementation issues, scope, limitations, and future extensions of the software are addressed. A survey is given of related algorithms and symbolic software to compute exact solutions of nonlinear differential equations.

Tangential Form of the Trace Condition for Pluriharmonic Functions in Cn

In this paper we introduce a tangential form of the trace condition for pluriharmonic functions on a smooth bounded domain in Cn that has some convexity. The condition obtained, in the bidimensional case, is related to the complex components of quaternionic regular functions. In the case of the unit ball of Cn, we rewrite the trace condition in terms of spherical harmonics.

Selective Hydrogenation for Fine Chemicals: Recent Trends and New Developments.

AbstractFor Abstract see ChemInform Abstract in Full Text.

On the Monodromy of a Multivalued Function along Its Ramification Locus

We consider multivalued analytic functions in ℂn) whose set of singular points occupies a very small part of ℂn). Under a mapping of a topological space Y into ℂn), such a function f can induce a multivalued function on Y. This is possible even if the image of Y entirely lies in the ramification set of f. We estimate the monodromy group of the induced function via the monodromy group of f.

Study on High Performance Averaging Method for a Strongly Nonlinear System. 1st Report, In Case that the Jacobian Elliptic Cosine Function is Used as a Generating Solution.

The averaging method improved by using the Jacobian elliptic function is developed in order to obtain a highly accurate periodic solution for a strongly nonlinear system. The Jacobian elliptic cosine function (so-called cn function) is used as a generating solution for the harmonically excited Duffing-type equation with hardening spring and damping. The stability for approximate solution obtained by the present method is also discussed. By comparing with the very accurate numerical solutions obtained by applying the shooting method, it is confirmed that the present method gives more accurate solution than that obtained by the traditional averaging method using the trigonometric function. In addition, not only the fundamental amplitude but also the higher harmonic amplitudes of the solution obtained by the present method are in good agreement with those obtained by the shooting method.

Cn Functions, Hausdorff Measures, and Analytic Sets

We characterize in terms of Hausdorff measures and descriptive complexity subsets M⊆R which are (1)the image under some Cn function f of the set of points where derivatives of first n orders are zero, (2)the set of points where the level sets of some Cn function are perfect, and (3)the set of points where the level sets of some Cn function are uncountable.

Opposite regulation of tissue factor expression by calcineurin in monocytes and endothelial cells.

Tissue factor (TF), the primary initiator of blood coagulation with structural homology to the cytokine receptor family, has been implicated in various vascular processes including metastasis, angiogenesis, and atherosclerosis. Within the vasculature, monocytes and endothelial cells (EC) can be activated to synthesize TF depending on the induction of NF-kappaB. Despite the undisputed value of cyclosporin A (CsA) as an immunosuppressant, problems have emerged due to induction of vascular changes by a poorly understood mechanism. We demonstrate that CsA has opposite effects on TF gene expression, inhibiting NF-kappaB-mediated TF gene transcription in monocytes but enhancing it in EC. To test whether CsA binding proteins (cyclophilins) can mediate these CsA effects we used a nonimmunosuppressant analog of CsA that binds to cyclophilins but does not inhibit the Ca2+/calmodulin-dependent phosphatase calcineurin (Cn). This drug lacked regulatory function for NF-kappaB and TF expression suggesting that Cn is responsible for the inverse gene regulation. The key function of Cn was supported by experiments demonstrating that other phosphatase inhibitors also either positively or negatively regulated NF-kappaB in monocytes and EC. Calcineurin was demonstrated to regulate NF-kappaB activation at the level of IkappaBalpha degradation, because agonist-induced phosphorylation and subsequent degradation of IkappaBalpha is prevented by Cn inhibitors in monocytes but enhanced in EC. These data identify Cn as an opposite regulator in generating transcriptionally active NF-kappaB, and they confirm the presumption that the ability of Cn to participate in NF-kappaB transactivation is not T cell specific.

Inverse scattering and Clifford analysis

We apply a Borel-Pompeiu formula for functions in ℂn to investigate the existence of admissible data for the inverse scattering problem in three spatial dimensions.