Stress memory polymers

Like shape memory polymers, a novel phenomenon of stress memory was shown in which the stress of a material can respond to an external stimulus. This concept was further enlightened by a switch‐spring‐frame model that would eliminate the limitation of existing models which overlooked the stimulus responsive nature of such polymers. The discovery being reported in this article was stemmed from a real case study into shape memory polymer fibers in compression stocking for varicose veins. The breakthrough of stress memory enabled researchers to develop applications needing stimuli‐responsive forces, which can broaden the horizon of such smart polymers in emerging smart products in many multidisciplinary fields such as sensors, stress garments, and massage devices, electronic skins, and artificial muscles. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 893–898     

Facile combustion synthesis of Ag2O nanoparticles using cantaloupe seeds and their multidisciplinary applications

Silver oxide nanoparticles (Ag₂O NPs) were prepared using cantaloupe (Cucumis melo) seeds as a fuel by employing a green synthesis method. The prepared Ag₂O NPs were investigated using powder X-ray diffraction (PXRD), UV–visible spectrum, Fourier transform infrared analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy-dispersive spectroscopy, and photoluminescence studies. PXRD data reveal the establishment of cubic crystal structure of Ag₂O NPs. According to SEM and TEM results, the morphology of the prepared NPs was agglomerated and spherical. The photodegradation activity of the prepared Ag₂O NPs over methylene blue dye was promising under visible light irradiation. Furthermore, the antimicrobial assay of the synthesized Ag₂O NPs was carried out by the disc diffusion method against Gram-positive and Gram-negative microbial strains.     

Aqueous Synthesis of N-Phenyl/alkyl-2-quinolinone-3-carboxylic Acids from Coumarin-3-carboxylic Acids

An efficient, ecofriendly aqueous synthesis of aromatic/aliphatic amines with coumarin-3-carboxylic acid in a one pot reaction in a sealed tube or InCl₃/ H₂O in open vessel to afford N-phenyl/alkyl-2-quinolinones is achieved. This method provides high yield of products in shorter time, making it a useful process for the synthesis of structurally diversified 2-quinolinones from corresponding coumarins.     

Insight into OroxylinA-7-O-β-d-Glucuronide-Enriched Oroxylum indicum Bark Extract in Oral Cancer HSC-3 Cell Apoptotic Mechanism: Role of Mitochondrial Microenvironment

Oroxylum indicum, of the Bignoniaceae family, has various ethnomedical uses such as an astringent, anti-inflammatory, anti-bronchitis, anti-helminthic and anti-microbial, including anticancer properties. The druggability of OI stem bark extract was determined by its molecular docking interactions with PARP and Caspase-3, two proteins involved in cell survival and death. Note that 50 µg/mL of Oroxylum indicum extract (OIE) showed a significant (p < 0.05%) toxicity to HSC-3 cells. MTT aided cell viability and proliferation assay demonstrated that 50 µg/mL of OIE displayed significant (p < 0.5%) reduction in cell number at 4 h of incubation time. Cell elongation and spindle formation was noticed when HSC-3 cells were treated with 50 µg/mL of OIE. OIE initiated DNA breakage and apoptosis in HSC-3 cells, as evident from DNA ladder assay and calcein/EB staining. Apoptosis potential of OIE is confirmed by flow cytometer and triple-staining (live cell/apoptosis/necrosis) assay. Caspase-3/7 fluorescence quenching (LANCE) assay demonstrated that 50 µg/mL of OIE significantly enhanced the RFU of caspases-3/7, indicating that the apoptosis potential of OIE is probably through the activation of caspases. Immuno-cytochemistry of HSC-3 cells treated with 50 µg/mL of OIE showed a significant reduction in mitochondrial bodies as well as a reduction in RFU in 60 min of incubation time. Immunoblotting studies clearly showed that treatment of HSC-3 cells with OI extract caused caspase-3 activation and PARP deactivation, resulting in apoptotic cell death. Overall, our data indicate that OIE is an effective apoptotic agent for human squamous carcinoma cells and it could be a future cancer chemotherapeutic target.     

Synthesis of Benzo[b]thiophene Substituted Carbamates,Ureas, Semicarbazides,and Pyrazoles and Their Antimicrobial and Analgesic Activity

2-Azidocarbonyl-3-chlorobenzo[b]thiophene 3 was obtained from 3-chloro-benzo[b]thiophene-2-carbonyl chloride 1 and 3-chloro-benzo[b]thiophene-2-carboxy hydrazide 2 . The compound 3 on Curtius rearrangement with various alcohols, amines, and hydrazines afforded the corresponding carbamates 4a–b , ureas 5a–j , and semicarbazides 6a–g , respectively. Compound 2 was also utilized for the synthesis of pyrazoles 7a–c by treatment with various chalcones. The structures of the newly synthesized compounds were elucidated on the basis of IR, ¹ H NMR, and mass spectral data and have been screened for antimicrobial and analgesic activities.     

SQUID-based measuring systems

A program has been developed and initiated at the Indira Gandhi Centre for Atomic Research (IGCAR) for the utilization of SQUID sensors in various application areas. DC SQUID sensors based on Nb-AlO _x -Nb Josephson junctions have been designed and developed inhouse along with associated flux-locked loop (FLL) electronics. A compact low field SQUID magnetometer insertible in a liquid helium storage dewar has also been developed inhouse and is in use. Efforts to build a high field SQUID magnetometer, SQUID-DAC system, are in progress. A planar gradiometric DC SQUID sensor for non-destructive evaluation (NDE) application to be used in relatively unshielded environment has been designed and developed. An easily portable NDE cryostat with a small lift-off distance, to be used in external locations has been designed and tested. The magnetic field produced by a given two-dimensional current density distribution is inverted using the Fourier transform technique.     

Constituent analysis of stress memory in semicrystalline polyurethane

Similar to shape memory, the stress in a stimulus responsive polymer can also be programmed, stored, and retrieved reversibly upon an external stimulus, and known as stress memory. Herein, the stress analysis in a semicrystalline polyurethane is investigated to unveil the total stress–strain components of the memory polymer. The evolution of stress under different temperature and strain levels is determined experimentally. A constitutive model based on phase transition was further used to predict and characterize the individual stress components during the thermomechanical process. In contrast to earlier models, a new approach of using relaxed modulus (RM) has been proposed to predict the stress components in tensile programming condition. The predicted results are having significant agreement with the experimental data. The quantitative stress analysis can help in engineering the products more precisely, where the controllable stimulus responsive stress is needed in multidisciplinary arenas such as pressure garments, massage devices, and artificial muscles etc. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 941–947     

On 5-regular bipartitions with even parts distinct

The Ramanujan Journal - In 2010, Andrews, Michael D. Hirschhorn and James A. Sellers considered the function ped(n), the number of partition of an integer n with even parts distinct (the odd parts...     

Mild,efficient Fischer indole synthesis using 2,4,6-trichloro-1,3,5-triazine (TCT)

Mild and efficient protocol for the Fischer indole synthesis using TCT has been described. TCT serves as a mild and inexpensive catalyst. Under these conditions several functional groups such as ester, cyano, sulfone, amides, and ethers are tolerated. By this method, many functionalized analytically pure indoles were prepared easily without the need of purification.