The first observation of a Na2TiS2 related structure in a 2-D anionic manganese trimesate intercalated by cationic imidazole

A hydrothermal reaction of Mn(OAc)2·4H2O, trimesic acid, imidazole, KOH and water at 75 °C for 24 h gave rise to a 2-D compound, [HImd][Mn(BTC)(H2O)] (Imd = imidazole; BTC = trimesate), with protonated imidazole molecules occupying the inter-lamellar space, and the structure resembles the classic inorganic compound, the sodium intercalated TiS2 (Na2TiS2).

G(its)(2) VSR: An Information Theoretic Secure Verifiable Secret Redistribution Protocol for Long-term Archival Storage

Protocols for secure archival storage are becoming increasingly important as the use of digital storage for sensitive documents is gaining wider practice. Wong et al.[8] combined verifiable secret sharing with proactive secret sharing without reconstruction and proposed a verifiable secret redistribution protocol for long term storage. However their protocol requires that each of the receivers is honest during redistribution. We proposed[3] an extension to their protocol wherein we relaxed the requirement that all the recipients should be honest to the condition that only a simple majority amongst the recipients need to be honest during the re(distribution) processes. Further, both of these protocols make use of Feldman's approach for achieving integrity during the (redistribution processes. In this paper, we present a revised version of our earlier protocol, and its adaptation to incorporate Pedersen's approach instead of Feldman's thereby achieving information theoretic secrecy while retaining integrity guarantees.

2.5-dimensional solution of the advective accretion disk:a self-similar approach

We provide a 2.5-dimensional solution to a complete set of viscous hydrodynamical equations describing accretion- induced outflows and plausible jets around black holes/compact objects. We prescribe a self-consistent advective disk-outflow coupling model, which explicitly includes the information of vertical flux. Inter-connecting dynamics of an inflow-outflow system essentially upholds the conservation laws. We provide a set of analytical family of solutions through a self-similar approach. The flow parameters of the disk-outflow system depend strongly on the viscosity parameter α and the cooling factor.

Simultaneous Electrodeposition of MnO2 and Mn(OH)(2) for Supercapacitor Studies

Among the various Mn compounds, both MnO2 and Mn(OH)2 are electrochemically active in supercapacitor studies. MnO2 and Mn(OH)2 are simultaneously deposited, through a one-pot method, on the anode and cathode, respectively, of a galvanostatic electrolysis cell consisting of aqueous Mn(NO3)2 electrolyte. MnO2 and Mn(OH)2 coated stainless steel (SS) electrodes are found to exhibit a capacitive behavior with a high specific capacitance. MnO2/SS and Mn(OH)2/SS electrodes are used as the negative and positive electrodes, respectively, in assembling nonsymmetrical capacitors and testing. The results indicate that both Mn-based electrodes prepared simultaneously in a single electrolysis possess interesting electrochemical properties for supercapacitor application.

Normalized wall index specific and MRI-based stress analysis of atherosclerotic carotid plaques: A study comparing acutely symptomatic and asymptomatic patients

Background: Biomechanical stresses play an important role in determining plaque stability. Quantification of these simulated stresses can be potentially used to assess plaque vulnerability and differentiate different patient groups. Methods and Results: 54 asymptomatic and 45 acutely symptomatic patients underwent in vivo multicontrast magnetic resonance imaging (MRI) of the carotid arteries. Plaque geometry used for finite element analysis was derived from in vivo MRI at the sites of maximum and minimum plaque burden. In total, 198 slices were used for the computational simulations. A pre-shrink technique was used to refine the simulation. Maximum principle stress at the vulnerable plaque sites (ie, critical stress) was extracted for the selected slices and a comparison was performed between the 2 groups. Critical stress in the slice with maximum plaque burden is significantly higher in acutely symptomatic patients as compared to asymptomatic patients (median, inter quartile range: 198.0 kPa (119.8-359.0 kPa) vs 138.4 kPa (83.8-242.6 kPa), P=0.04). No significant difference was found in the slice with minimum plaque burden between the 2 groups (196.7 kPa (133.3-282.7 kPa) vs 182.4 kPa (117.2-310.6 kPa), P=0.82). Conclusions: Acutely symptomatic carotid plaques have significantly high biomechanical stresses than asymptomatic plaques. This might be potentially useful for establishing a biomechanical risk stratification criteria based on plaque burden in future studies.

Stress analysis of carotid plaque based on in vivo MRI of acute symptomatic and asymptomatic patients

Stress analysis within carotid plaques based on in vivo MR imaging has shown to be useful for the identification of vulnerable atheroma. This study is to investigate whether magnetic resonance imaging (MRI) based-biomechanical stress analysis of carotid plaques can differentiate acute symptomatic and asymptomatic patients. 54 asymptomatic and 45 acute symptomatic patients underwent in vivo multi-contrast MRI of the carotid arteries. Plaque geometry used for finite element analysis was derived from in vivo MR images at the site of maximum and minimum plaque burden. In total 198 slices were used for the computational simulations. A pre shrink technique was used to refine the simulation. Maximum principle stress at the vulnerable plaque sites (i.e. critical stress) was extracted for the selected slices and a comparison was performed between the two groups. Critical stress at the site of maximum plaque burden is significantly higher in acute symptomatic patients as compared to asymptomatic patients [median: 198.0kPa (inter quartile range (IQR) = (119.8 - 359.0) vs. 138.4kPa (83.8, 242.6), p=0.04]. No significant difference was found at the minimum plaque burden site between the two groups [196.7kPa (133.3- 282.7) vs. 182.4kPa (117.2 - 310. 6), p=0.82). Stress analysis at the site of maximal plaque burden can be effectively used for differentiating acute symptomatic carotid plaques from asymptomatic plaques. This maybe potentially used for development of biomechanical risk stratification criteria based on plaque burden in future studies.

Syntheses and characterization of trans-[NiL2(NCS)2][L = 2-(aminomethyl) pyridine], trans-[NiL02(NSC)2][L0 = 2-(2-aminoethyl)pyridine] and trans-[NiL00 2(NSC)2] [L00 = 2-(2-methylaminoethyl)pyridine] complexes: X-ray single crystal structure of trans-[NiL02(NSC)2] [L0 = 2-(2-aminoethyl)pyridine]

[NiL2(NCS)2] (1) [L = 2-(aminomethyl)pyridine], [NiL02(NCS)2] (2) [(L0) = 2-(2-aminoethyl)pyridine and [NiL00 2(NCS)2] (3) [L00 = 2-(2-methylaminoethyl)pyridine] have been synthesized from solution. All the complexes possess trans geometry as is evident from solid state UV–Vis spectral study and X-ray single crystal structure analysis of complex 2 unambiguously proves trans geometry of the species.

Synthesis, antimicrobial and cytotoxic activities of 1,3,4-oxadiazoles, 1,3,4-thiadiazoles and 1,2,4-triazoles

A new class of 1,3,4-oxadiazoles were prepared from acid hydrazides on treatment with different carboxylic acids in the presence of phosphorus oxychloride. Interconversion of oxadiazoles to thiadiazoles and triazoles was carried out with appropriate reagents. The antimicrobial and cytotoxic activities of compounds 7a-d to 12a-d were tested. Compounds 10d and 12d showed pronounced antimicrobial activity. Further, compound 10d exhibited maximum cytotoxicity. (C) 2008 Elsevier Masson SAS. All rights reserved.

Structure of nonactin-calcium perchlorate, C40H64O12.Ca(ClO4)2, and a comparative study of metal-nonactin complexes

M r= 975.9, orthorhombic, Pnna, a = 20.262 (3), b= 15.717 (2), c= 15.038 (1)A, V= 4788.97 A 3, z = 4, D x = 1.35 Mg m -3, Cu Kct radiation, 2 = 1.5418 A, /t = 2.79 mm -1, F(000) -= 2072, T = 293 K, R = 0.08, 3335 observed reflections. The molecular structure and the crystal packing are similar to those observed in the nonactin complexes of sodium thiocyanate and potassium thiocyanate. The eight metal-O distances are nearly the same in the potassium complex whereas the four distances involving carbonyl O atoms are shorter than the remaining four involving the tetrahydrofuran-ring O atoms in the Na and the Ca complexes. This observation can be explained in terms of the small ionic radii of Na + and Ca 2+, and leads to a plausible structural rationale for the stronger affinity of nonactin for K + than for the other two metal ions.

A thermal molecular migration in the solid-state - structures of isomeric 5-amino-4-(2,6-dichlorophenyl)-1-(2-nitrophenyl)-1h-1,2,3-triazole (yellow form i) and 4-(2,6-dichlorophenyl)-5-(2-nitroanilino)-2h-1,2,3-triazole (red form-ii), c14h9cl2n5o2

Yellow form (I): Mr= 350.09, monoclinic, P2Jn, Z--4, a=9.525(1), b=14.762(1), c= 11.268(1),/t, fl= 107.82 (1) o , V= 1508.3 A 3 , Din(flotation in aqueous KI)= 1.539 (2), D x= 1.541 (2) g cm -3, #(Cu Ka, 2 = 1.5418 A) = 40.58 cm -~, F(000) = 712, T= 293 K, R = 8.8% for 2054 significant refections. Red form (II): Mr= 350.09, triclinic, Pi, Z=2, a=9.796(2), b= 10.750 (2), c= 7.421 (1)A, a= 95.29 (2), fl= 0108-2701/84/111901-05501.50 70.18 (1), y = 92-.76 (2) °, V= 731.9 A 3, Din(flotation in KI) = 1.585 (3), D x = 1.588 (3) g cm -3, ~t(Cu Ka, 2 = 1.5418/~) = 40.58 cm -1, F(000) = 356, T=293 K, R = 5.8% for 1866 significant reflections. There are no unusual bond distances or angles. The triazole and two phenyl rings are planar. On the basis of packing considerations the possibility of intermolecular interactions playing a role in the reactivity of the starting material is ruled out.

Acid-catalysed cyclisations: structures of novel products isolated in the reaction of 2-[3-(2,6-dimethoxyphenyl)but-2-enyl]-2-methylcyclopentane-1,3-dione with MeOH-HCl

Reaction of the title compound (1a) with anhydrous MeOH-HCl gave 2-endo-(2,6-dimethoxyphenyl)-2-exo-methyl-5-methylbicyclo[3.2.1]octane-6,8-dione (3a), 1,5,14-timethoxy-5,8-seco-6,7-dinorestra-1,3,5(10),9(11)-tetraen-17-one (4), 1,5-dimethoxy-5,8-seco-6,7-dinorestra-1,3,5(10),8,14-pentaen-17-one (5), and 3,4,5,6-tetrahydro-2,7-dimethoxy-3,6-dimethyl-3,2,6-(13-oxopropan[1]yI[3]ylidene)-2H-1-benzoxocin (6). Structures assigned to compounds (3a), (4), and (6) are based on spectral data. The exo-tricyclic acetal structure (6) was further confirmed by the analysis of the 1H n.m.r. spectra of the isomeric alcohols (11) and (12), obtained by sodium borohydride reduction of (6).

NMR-Studies of Octahedral Dicyano-(2,2' Bipyridine) and Tetracyano-(2,2'-Bipyridine) Iron(ii) Complexes

Coordination compounds of the polypyridines, 2,2 ' -bipyridine (bipy) and 1,10-penanthroline (phen) have offered renewed interest on account of their manifold applications and from the point of view of understanding their structure-reactivity relationships.1 Iron(II) reacts with them to form tris-complexes possessing spin-paired ground states. Cyanide ion greatly enhances the rate of displacement of bipy or phen to form the Schilt class of compounds. Fe(bipy)2(CN)2 and Fe(phen)2(CN)2. They display varying colours in solution depending upon the nature of the solvent and react reversibly with acids to form diprotonated species.2 Magnetic circular dichroism studies have been reported to describe their lowest electronic excitation.

Structure of 5'-O-acetyl-2',3'-O-isopropylideneuridine, C14H18N2O7

M r = 326.3, monoclinic, P21, a --= 6.510 (2), b=8.432 (2), c= 15.114 (2),a, /~= 101.42 (3) ° , Z = 2, V= 813.15 A 3, D x = 1-33 Mg m -3, F(000) = 172, 2(Cu Ka) = 1.5418/~,, g(Cu Ka) = 0.906 mm -~, final R = 6.4% for 1924 observed counter reflections. The conformation about the glycosidic bond is syn [torsion angle C(6)-N(1)-C(1')-O(4')=-103.9(3)°]. The sugar pucker is C(2')-exo,C(3')-endo (3Tz). The conformation about the C(4')-C(5') bond is gauche-trans. An uncommon intermolecular hydrogen bond involving the ribose-ring oxygen O(1') and the base-nitrogen N(3) stabilizes the crystal structure.