A Novel Synthetic Protocol for the Heteroannulation of Oxocarbazole and Oxoazacarbazole Derivatives through Corresponding Oxoketene Dithioacetals

An efficient novel strategy for the heteroannulation of 6,7‐dihydropyrazolo[3,4‐b]carbazol‐8(1H,5H,9H)‐one 4 and 5‐N‐benzyl‐6,7‐dihydropyrazolo[3,4‐b]carbazol‐8(1H,9H)‐one 5 has been developed to allow the incorporation of pyrazole, isoxazole, pyrimidine, benzodiazepine, and benzothiazepine rings through their corresponding oxoketene dithioacetal derivatives 6 and 7 , respectively.     

Cyclodextrin based drug delivery system of protease inhibitor—nelfinavir mesylate

The purpose of present investigation was to understand the interactions involved in complexation of Nelfinavir Mesylate (NM)—a protease inhibitor, used in the treatment of HIV/AIDS with Beta-cyclodextrin (β-CD) and its subsequent effect on its absorption properties and bioavailability. Milling method was used for complexation. The inclusion complexes were characterized by 2D NOESY NMR and ITC studies. The feasibility of findings was further confirmed by using Cerius² software of Tripos Inc. using Silicon Graphics O_2. Pharmacokinetic studies were carried out in rabbits and data was treated by Student’s t Test. 2D NOESY NMR studies showed very intricate behavior showing interactions amongst drug and β-CD molecule as well as amongst β-CD–β-CD molecules. This fact of formation of molecular aggregates was further confirmed by ITC studies. Computer simulation studies further supported the finding of forming shallow complex. The percent relative bioavailability of complex at the dose of 400 mg/kg in rabbits was 185.37 as compared to the plain NM at 400 mg/kg dose. The studies were conducted at low dose of 200 mg/kg of drug in the form of complex in rabbit does not show statistically significant difference in AUC, T _1/2 and Kel. as compared to plain drug at 400 mg/kg of rabbit.     

Spin fluctuation and local magnetism of isolated Fe impurities in Pd<Subscript>1−x</Subscript>V<Subscript>x</Subscript> alloys studied by time differential perturbed angular distribution spectroscopy

The magnetic moment and spin fluctuation temperature of isolated Fe impurity atoms in Pd_1?xV_x (0 ≤ x ≤ 0.15) alloys have been studied by time differential perturbed angular distribution (TDPAD) technique. With increasing V content in Pd matrix, a large non-linear reduction of the local magnetic moment accompanied with an exponential increase of the spin fluctuation temperature T_SF has been observed. At and beyond x = 0.12, the Fe atoms are found to be nonmagnetic. As an important new feature, T_SF is observed to vary quadratically with composition dependent changes in host spin polarization.     

Synthesis,characterization and phase transition studies in 4-hexyloxy benzylidene 4’-alkoxyanilines

Synthesis and the characterization through polarizing optical microscope (POM) textures in number of 4-hexyloxy benzylidene 4’-alkoxyanilines, 6O.Om with m = 4, 6 to 10 liquid crystalline materials are carried out. Furthermore, the density and thermal expansion coefficient results reveal that the phase transitions present, viz., isotropic–nematic, nematic–SmC and SmC–SmI show first-order nature as expected. The transition temperatures obtained thorough the differential scanning calorimetry is found to be in agreement with the literature data. The first two compounds exhibit only the nematic phase while the next four compounds show enantiotropic SmC phase as per the literature data. The compound with m = 10 exhibits monotropic SmI phase. However, we, the authors, are able to observe this phase in addition to SmC and nematic through POM only as per the literature. The parameters calculated across the phase transitions and in the phases are in agreement with the body of the data available.     

Mechanism of manganese (mono and di) telluride thin-film formation and properties

Mechanistic studies on the electrocrystallization of manganese telluride (MnTe) thin film are reported using aqueous acidic solution containing MnSO₄ and TeO₂. Tartaric acid was used for the inhibition of hydrated manganese oxide anodic growth at counter electrode. A detailed study on the mechanistic aspect of electrochemical growth of MnTe using cyclic voltametry is carried out. Conditions for electrochemical growth of manganese mono and di telluride thin films have been reported using cyclic voltammetric scans for Mn²⁺, Te⁴⁺ and combined Mn²⁺ and Te⁴⁺. X-ray diffraction showed the formation of polycrystalline MnTe films with cubic, hexagonal and orthorhombic mixed phases. MnTe film morphology was studied using scanning electron microscope. Susceptibility and electrical characterization supports the anti-ferromagnetic behavior of the as-deposited MnTe thin film.     

Hydrazine reduced exfoliated graphene/graphene oxide layers and?magnetoconductance measurements of Ge-supported graphene layers

Inexpensive production and characteristic magnetoconductance fluctuation of Ge-supported stable graphene/graphene oxide layers are being reported. The changeover from graphite to graphene oxide structure during synthesis was evident from X-ray diffraction patterns whereas development of mono and bilayer graphene/graphene oxide was confirmed by electron microscopy studies. Responding to applied magnetic fields (up to 0.3 T), the Ge-supported graphene layers are shown to exhibit prominent magnetoconductance steps and are attributed to the alteration of Landau levels across the Fermi surface. While low-cost fabrication process is attractive for large scale production, the advantage of short synthesis time and understanding magneto-transport mechanism would find relevance in graphene-based nanodevices and circuits.     

Peacock feather supported self assembled ZnO nanostructures for tuning photonic properties

Barbules of the peacock feather have been used as the natural template for developing assemblies of zinc oxide (ZnO) nanospheres. The different colored barbules consisting of various photonic crystals (extracted from eye-pattern) were characterized in terms of the stop-bands identified in the respective Reflectance spectra. The stop-bands of the photonic crystals are found to get red-shifted after the loading of ZnO nanospheres and was reasoned to the modification of photonic band gap. The ZnO nanosphere decorated barbules show well defined photoluminescence response with dominant defect related emission of ZnO. The artificially grown inorganic structures on natural templates form a basis of new hybrid system that can help in exploiting photonic band gap engineering and light wave modulation with high selectivity.     

Nondestructive evaluation of helicopter rotor blades using guided Lamb modes

This paper presents an application for turning and direct modes in a complex composite laminate structure. The propagation and interaction of turning modes and fundamental Lamb modes are investigated in the skin, spar and web sections of a helicopter rotor blade. Finite element models were used to understand the various mode conversions at geometric discontinuities such as web-spar joints. Experimental investigation was carried out with the help of air coupled ultrasonic transducers. The turning and direct modes were confirmed with the help of particle displacements and velocities. Experimental B-Scans were performed on damaged and undamaged samples for qualitative and quantitative assessment of the structure. A strong correlation between the numerical and experimental results was observed and reported.