Angelica archengelica extract induced perturbation of rat skin and tight junctional protein (ZO-1) of HaCaT cells

Background and purpose of the study: Herbal enhancers compared to the synthetic ones have shown less toxis effects. Coumarins have been shown at concentrations inhibiting phospoliphase C-Y (Phc-Y) are able to enhance tight junction (TJ) permeability due to hyperpoalation of Zonolous Occludense-1 (ZO-1) proteins. The purpose of this study was to evaluate the influence of ethanolic extract of Angelica archengelica (AA-E) which contain coumarin on permeation of repaglinide across rat epidermis and on the tight junction plaque protein ZO-1 in HaCaT cells. Methods: Transepidermal water loss (TEWL) from the rat skin treated with different concentrations of AA-E was assessed by Tewameter. Scanning and Transmission Electron Microscopy (TEM) on were performed on AA-E treated rat skin portions. The possibility of AA-E influence on the architecture of tight junctions by adverse effect on the cytoplasmic ZO-1 in HaCaT cells was investigated. Finally, the systemic delivery of repaglinide from the optimized transdermal formulation was investigated in rats. Results: The permeation of repaglinide across excised rat epidermis was 7-fold higher in the presence of AA-E (5% w/v) as compared to propylene glycol:ethanol (7:3) mixture. The extract was found to perturb the lipid microconstituents in both excised and viable rat skin, although, the effect was less intense in the later. The enhanced permeation of repaglinide across rat epidermis excised after treatment with AA-E (5% w/v) for different periods was in concordance with the high TEWL values of similarly treated viable rat skin. Further, the observed increase in intercellular space, disordering of lipid structure and corneocyte detachment indicated considerable effect on the ultrastructure of rat epidermis. Treatment of HaCaT cell line with AA-E (0.16% w/v) for 6 hrs influenced ZO-1 as evidenced by reduced immunofluorescence of anti-TJP1 (ZO-1) antibody in Confocal Laser Scanning Microscopy studies (CLSM) studies. The plasma concentration of repaglinide from transdermal formulation was maintained higher and for longer time as compared to oral administration of repaglinide. Major conclusion: Results suggest the overwhelming influence of Angelica archengelica in enhancing the percutaneous permeation of repaglinide to be mediated through perturbation of skin lipids and tight junction protein (ZO-1).

The Wiener-Hopf solution of a class of mixed boundary value problems arising in surface water wave phenomena

Two mixed boundary value problems associated with two-dimensional Laplace equation, arising in the study of scattering of surface waves in deep water (or interface waves in two superposed fluids) in the linearised set up, by discontinuities in the surface (or interface) boundary conditions, are handled for solution by the aid of the Weiner-Hopf technique applied to a slightly more general differential equation to be solved under general boundary conditions and passing on to the limit in a manner so as to finally give rise to the solutions of the original problems. The first problem involves one discontinuity while the second problem involves two discontinuities. The reflection coefficient is obtained in closed form for the first problem and approximately for the second. The behaviour of the reflection coefficient for both the problems involving deep water against the incident wave number is depicted in a number of figures. It is observed that while the reflection coefficient for the first problem steadily increases with the wave number, that for the second problem exhibits oscillatory behaviour and vanishes at some discrete values of the wave number. Thus, there exist incident wave numbers for which total transmission takes place for the second problem. (C) 1999 Elsevier Science B.V. All rights reserved.

A facile entry into a new class of spiroheterocycles: synthesis of dispiro[oxindolechromanone/flavanone/tetralone]pyrroloisoquinoline ring systems

A series of novel dispiroheterocyclic systems have been synthesized by the cycloaddition of a new azomethine ylide generated by the decarboxylative route from tetrahydroisoquinoline-3-carboxylic acid and isatin with various dipolarophiles containing exocyclic double bond such as 3-arylidene-4-chromanone, 3-arylidene-4-flavanone and 2-arylidenetetrahydro-1-naphthalenone in moderate to good yield. The regio and stereochemistry of the title compounds was established by single crystal X-ray structure and spectroscopic techniques. (C) 2002 Elsevier Science Ltd. All rights reserved.

A new class of three dimensional D-pi-A trigonal cryptand derivatives for second-order nonlinear optics

Synthesis, crystal structures, linear and nonlinear optical properties of tris D-pi-A cryptand derivatives with C-3 symmetry are reported. Three fold symmetry inherent in the cryptand molecules has been utilized for designing these molecules. Molecular nonlinearities have been measured by hyper-Rayleigh scattering (HRS) experiments. Among the compounds studied, L-1 adopts non-centrosymmetric crystal structure. Compounds L-1, L-2, L-3 and L-4 show a measurable SHG powder signal. These molecules are more isotropic and have significantly higher melting points than the classical p-nitroaniline based dipolar NLO compounds, making them useful for further device applications. Besides, different acceptor groups can be attached to the cryptand molecules to modulate their NLO properties.

Optimization of off-oriented Ge substrates for MOVPE-grown GaAs solar cells

GaAs/Ge heterostructures having abrupt interfaces were grown on 2degrees, 6degrees, and 9degrees off-cut Ge substrates and investigated by cross-sectional high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy, photoluminescence spectroscopy and electrochemical capacitance voltage (ECV) profiler. The GaAs films were grown on off-oriented Ge substrates with growth temperature in the range of 600-700degreesC, growth rate of 3-12 mum/hr and a V/III ratio of 29-88. The lattice indexing of HRTEM exhibits an excellent lattice line matching between GaAs and Ge substrate. The PL spectra from GaAs layer on 6degrees off-cut Ge substrate shows the higher excitonic peak compared with 2degrees and 9degrees off-cut Ge substrates. In addition, the luminescence intensity from the GaAs solar cell grown on 6degrees off-cut is higher than on 9degrees off-cut Ge substrates and signifies the potential use of 6degrees off-cut Ge substrate in the GaAs solar cells industry. The ECV profiling shows an abrupt film/substrate interface as well as between various layers of the solar cell structures.

Remarkable photocytotoxicity in hypoxic HeLa cells by a dipyridophenazine copper(II) Schiff base thiolate

Copper(II) complexes Cu(satp)(L)] (1-3) of a Schiff base thiolate (salicylidene-2-aminothiophenol, H(2)satP) and phenanthroline bases (L), viz. 1,10-phenanthroline (phen in 1), dipyrido3,2-d:2',3'-f]quinoxaline (dpq in 2) and dipyrido3,2-a:2',3'-c]phenazine (dppz in 3), were prepared, characterized and their anaerobic DNA photocleavage activity and hypoxic photocytotoxicity studied. The redox active complexes show the Cu(II)-Cu(I) couple near -0.5 V for 1 and near 0.0 V vs. SCE (saturated calomel electrode) for 2 and 3. The one-electron paramagnetic complexes (similar to 1.85 mu(B)) are avid DNA binders giving K(b) values within 1.0 x 10(5) - 8.0 x 10(5) M(-1). Thermal melting and viscosity data along with molecular docking calculations suggest DNA groove and/or partial intercalative binding of the complexes. The complexes show anaerobic DNA cleavage activity in red light under argon via type-I pathway, while DNA photocleavage in air proceeds via hydroxyl radical pathway. The DFT (density functional theory) calculations reveal a thyil radical pathway for the anaerobic DNA photocleavage activity and suggest the possibility of generation of a transient copper(I) species due to bond breakage between the copper and sulfur to generate the thyil radical. An oxidation of the copper(I) species is likely by oxygen in an aerobic medium or by the buffer medium in an anaerobic condition. Complex 3 exhibits significant photocytotoxicity in HeLa cells (IC(50) = 8.3(+/- 1.0) mu M) in visible light, while showing lower dark toxicity (IC(50) = 17.2(+/- 1.0) mu M). A significant reduction in the dark toxicity is observed under hypoxic cellular conditions (IC(50) = 30.0(+/- 1.0) mu M in dark), while retaining its photocytotoxicity (IC(50) = 8.0(+/- 1.0) mu M). (C) 2011 Elsevier Inc. All rights reserved.

Calcium ruthenates: Determination of Gibbs energies of formation using electrochemical cells

Metallic Ru has been found to coexist separately with CaO, RuO2, and the interoxide phases, Ca2RuO4, Ca3Ru2O7, and CaRuO3, present along the pseudobinary system CaO-RuO2. The standard Gibbs energies of formation (Df((ox))G(o)) of the three calcium ruthenates from their component oxides have been measured in the temperature range 925-1350 K using solid-state cells with yttria-stabilized zirconia as the electrolyte and Ru+RuO2 as the reference electrode. The standard Gibbs energies of formation (Deltaf((ox))G(o)) of the compounds can be represented by Ca2RuO4:Deltaf((ox))G(o)/J mol(-1)=-38,340-6.611 T (+/-120), Ca3Ru2O7 : Df((ox))G(o)/J mol(-1)=-75,910-11.26 T (+/-180), and CaRuO3 : Deltaf((ox))G(o)/J mol(-1)=-35,480-3.844 T(+/-70). The data for Ca2RuO4 corresponds to the stoichiometric composition, which has an orthorhombic structure, space group Pbca, with short c axis ("S'' form). The structural features of the ternary oxides responsible for their mild entropy stabilization are discussed. A three-dimensional oxygen potential diagram for the system Ca-Ru-O is developed as a function of composition and temperature from the results obtained. Using the Neumann-Kopp rule to estimate the heat capacity of the ternary oxides relative to their constituent binary oxides, the standard enthalpies of formation of the three calcium ruthenates from the elements and their standard entropies at 298.15 K are evaluated. (C) 2003 The Electrochemical Society.

Critical properties of the double-exchange ferromagnet Nd(0.6)Pb(0.4)MnO(3)

Results of a study of dc magnetization M(T,H), performed on a Nd(0.6)Pb(0.4)MnO(3) single crystal in the temperature range around T(C) (Curie temperature) which embraces the supposed critical region \epsilon\=\T-T(C)\/T(C)less than or equal to0.05 are reported. The magnetic data analyzed in the critical region using the Kouvel-Fisher method give the values for the T(C)=156.47+/-0.06 K and the critical exponents beta=0.374+/-0.006 (from the temperature dependence of magnetization) and gamma=1.329+/-0.003 (from the temperature dependence of initial susceptibility). The critical isotherm M(T(C),H) gives delta=4.54+/-0.10. Thus the scaling law gamma+beta=deltabeta is fulfilled. The critical exponents obey the single scaling equation of state M(H,epsilon)=epsilon(beta)f(+/-)(H/epsilon(beta+gamma)), where f(+) for T>T(C) and f(-) for Tclass of three-dimensional Heisenberg ferromagnets with short-range interactions.

Insulin Growth Factor-2 Binding Protein 3 (IGF2BP3) Is a Glioblastoma-specific Marker That Activates Phosphatidylinositol 3-Kinase/Mitogen-activated Protein Kinase (PI3K/MAPK) Pathways by Modulating IGF-2

Glioblastoma is the most common and malignant form of primary astrocytoma. Upon investigation of the insulin-like growth factor (IGF) pathway, we found the IGF2BP3/IMP3 transcript and protein to be up-regulated in GBMs but not in lower grade astrocytomas (p<0.0001). IMP3 is an RNA binding protein known to bind to the 5'-untranslated region of IGF-2 mRNA, thereby activating its translation. Overexpression-and knockdown-based studies establish a role for IMP3 in promoting proliferation, anchorage-independent growth, invasion, and chemoresistance. IMP3 overexpressing B16F10 cells also showed increased tumor growth, angiogenesis, and metastasis, resulting in poor survival in a mouse model. Additionally, the infiltrating front, perivascular, and subpial regions in a majority of the GBMs stained positive for IMP3. Furthermore, two different murine glioma models were used to substantiate the above findings. In agreement with the translation activation functions of IMP3, we also found increased IGF-2 protein in the GBM tumor samples without a corresponding increase in its transcript levels. Also, in vitro IMP3 overexpression/knockdown modulated the IGF-2 protein levels without altering its transcript levels. Additionally, IGF-2 neutralization and supplementation studies established that the proproliferative effects of IMP3 were indeed mediated through IGF-2. Concordantly, PI3K and MAPK, the downstream effectors of IGF-2, are activated by IMP3 and are found to be essential for IMP3-induced cell proliferation. Thus, we have identified IMP3 as a GBM-specific proproliferative and proinvasive marker acting through IGF-2 resulting in the activation of oncogenic PI3K and MAPK pathways.

Cooperative Regulation of NOTCH1 Protein-Phosphatidylinositol 3-Kinase (PI3K) Signaling by NOD1, NOD2, and TLR2 Receptors Renders Enhanced Refractoriness to Transforming Growth Factor-beta (TGF-beta)- or Cytotoxic T-lymphocyte Antigen 4 (CTLA-4)-mediated Impairment of Human Dendritic Cell Maturation

Dendritic cells (DCs) as sentinels of the immune system are important for eliciting both primary and secondary immune responses to a plethora of microbial pathogens. Cooperative stimulation of a complex set of pattern-recognition receptors, including TLR2 and nucleotide-binding oligomerization domain (NOD)-like receptors on DCs, acts as a rate-limiting factor in determining the initiation and mounting of the robust immune response. It underscores the need for ``decoding'' these multiple receptor interactions. In this study, we demonstrate that TLR2 and NOD receptors cooperatively regulate functional maturation of human DCs. Intriguingly, synergistic stimulation of TLR2 and NOD receptors renders enhanced refractoriness to TGF-beta- or CTLA-4-mediated impairment of human DC maturation. Signaling perturbation data suggest that NOTCH1-PI3K signaling dynamics assume critical importance in TLR2- and NOD receptor-mediated surmounting of CTLA-4- and TGF-beta -suppressed maturation of human DCs. Interestingly, the NOTCH1-PI3K signaling axis holds the capacity to regulate DC functions by virtue of PKC delta-MAPK-dependent activation of NF-kappa B. This study provides mechanistic and functional insights into TLR2-and NOD receptor-mediated regulation of DC functions and unravels NOTCH1-PI3K as a signaling cohort for TLR2 and NOD receptors. These findings serve in building a conceptual foundation for the design of improved strategies for adjuvants and immunotherapies against infectious diseases.

Influence of the highest occupied molecular orbital energy level of the donor material on the effectiveness of the anode buffer layer in organic solar cells

Efficiency of organic photovoltaic cells based on organic electron donor/organic electron acceptor junctions can be strongly improved when the transparent conductive Anode is coated with a Buffer Layer (ABL). Here, the effects of a metal (gold) or oxide (molybdenum oxide) ABL are reported, as a function of the Highest Occupied Molecular Orbital (HOMO) of different electron donors. The results indicate that a good matching between the work function of the anode and the highest occupied molecular orbital of the donor material is the major factor limiting the hole transfer efficiency. Indeed, gold is efficient as ABL only when the HOMO of the organic donor is close to its work function Phi(Au). Therefore we show that the MoO(3) oxide has a wider field of application as ABL than gold. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Synthesis and Antileukemic Activity of Novel 4-(3-(Piperidin-4-yl) Propyl)Piperidine Derivatives

To explore the anticancer effect associated with the piperidine framework, several (substituted phenyl) {4-[3-(piperidin-4-yl)propyl]piperidin-1-yl} methanone derivatives 3(a-i) were synthesized. Variation in the functional group at N-terminal of the piperidine led to a set of compounds bearing amide moiety. Their chemical structures were confirmed by (1)H NMR, IR and mass spectra analysis. Among these, compounds 3a, 3d and 3e were endowed with antiproliferative activity. The most active compound among this series was 3a with nitro and fluoro substitution on the phenyl ring of aryl carboxamide moiety, which inhibited the growth of human leukemia cells (K562 and Reh) at low concentration. Comparison with other derivative (3h) results shown by LDH assay, cell cycle analysis and DNA fragmentation suggested that 3a is more potent to induce apoptosis.

Ferromagnetic transition and specific heat of Pr(0.6)Sr(0.4)MnO(3)

The critical properties of orthorhombic Pr(0.6)Sr(0.4)MnO(3) single crystals were investigated by a series of static magnetization measurements along the three different crystallographic axes as well as by specific heat measurements. A careful range-of-fitting-analysis of the magnetization and susceptibility data obtained from the modified Arrott plots shows that Pr(0.6)Sr(0.4)MnO(3) has a very narrow critical regime. Nevertheless, the system belongs to the three-dimensional (3D) Heisenberg universality class with short-range exchange. The critical exponents obey Widom scaling and are in excellent agreement with the single scaling equation of state M(H,epsilon) = vertical bar epsilon vertical bar(beta) f(+/-)(H/vertical bar epsilon vertical bar((beta+gamma)); with f(+) for T > T(c) and f(-) for T < T(c). A detailed analysis of the specific heat that account for all relevant contributions allows us to extract and analyze the contribution related to the magnetic phase transition. The specific heat indicates the presence of a linear electronic term at low temperatures and a prominent contribution from crystal field excitations of Pr. A comparison with data from literature for PrMnO(3) shows that a Pr-Mn magnetic exchange is responsible for a sizable shift in the lowest lying excitation.

Novel thiophene derivative hybrid composite solar cells

In this work composites of poly(3-hexylethiophene) (P3HT) and a thiophene derivative (7, 9-di (thiophen-2-yl)-8H-cyclopenta[a]acenaphthylen-8-one) (DTCPA) having donor acceptor architecture (DAD) were prepared. Photovoltaic properties of these hybrid composites were evaluated. DTCPA, which is a highly crystalline organic molecule with wide absorption range, was observed to improve the open circuit voltage of the solar cell. Furthermore, DTCPA crystals acts as a nucleating center and increases the molecular ordering of P3HT in the composite. Improved charge separation efficiency was observed by photoluminescence spectroscopy. Because of high built in potential in these devices, large open circuit voltage was observed. (C) 2011 Elsevier B.V. All rights reserved.

Electrochemical oxidation of boron containing compounds on titanium carbide and its implications to direct fuel cells

Electrochemical oxidation of sodium borohydride (NaBH(4)) and ammonia borane (NH(3)BH(3)) (AB) have been studied on titanium carbide electrode. The oxidation is followed by using cyclic voltammetry, chronoamperometry and polarization measurements. A fuel cell with TiC as anode and 40 wt% Pt/C as cathode is constructed and the polarization behaviour is studied with NaBH(4) as anodic fuel and hydrogen peroxide as catholyte. A maximum power density of 65 mW cm(-2) at a load current density of 83 mA cm(-2) is obtained at 343 K in the case of borhydride-based fuel cell and a value of 85 mW cm(-2) at 105 mA cm(-2) is obtained in the case of AB-based fuel cell at 353 K. (C) 2011 Elsevier Ltd. All rights reserved.