Self-Healable Hydrophobic Material Based on Anthracenyl Functionalized Fluorous Block Copolymers via Reversible Addition-Fragmentation Chain Transfer Polymerization and Rapid Diels–Alder Reaction

Recently, among the available approaches to develop self-healable materials, 1,2,4-triazoline-3,5-dione (TAD)-based Diels–Alder (DA) chemistry has gained tremendous attention, becuase this DA reaction is very rapid under ambient conditions. This study delineates developing a self-healing hydrophobic fluorinated polymer utilizing dynamic and rapid TAD-DA chemistry. For this purpose, block copolymers of 2-hydroxyethyl methacrylate (HEMA) and 2,2,2-trifluoroethylmethacrylate (TFEMA) are prepared via reversible addition-fragmentation chain transfer polymerization. Subsequently, the pendant hydroxyl groups of the HEMA repeat units are modified with anthracenyl functionality via esterification with 9-anthracenecarboxylic acid. The tailor-made polymer-bearing anthracenyl pendants are subsequently crosslinked via a rapid DA reaction using a bifunctional TAD derivative at room temperature (r.t.). Differential scanning calorimetry (DSC) analysis is performed to interpret the thermoreversible behavior of the TAD-derived DA polymer. The self-healing characteristics of this TAD-derived DA conjugate are studied by monitoring the healing of a notched surface via AFM analysis. Interestingly, the TAD conjugated fluoropolymers are hydrophobic, as evidenced by the water contact angle analysis. Such TAD-derived DA fluoropolymer conjugates with remarkable hydrophobic characteristics and excellent self-healing features can pave a new direction in the potential materials for specialty paints, coatings, and adhesives.     

Supramolecular Interaction of Molecular Cage and β-Galactosidase: Application in Enzymatic Inhibition,Drug Delivery and Antimicrobial Activity

Enzyme inhibitors play a crucial role in diagnosis of a wide spectrum of diseases related to bacterial infections. We report here the effect of a water-soluble self-assembled Pd^II₈ molecular cage towards β-galactosidase enzyme activity. The molecular cage is composed of a tetrapyridyl donor ( L ) and cis-[(en)Pd(NO₃)₂] (en=ethane-1,2-diamine) acceptor and it has a hydrophobic internal cavity. We have observed that the acceptor moiety mainly possesses the ability to inactivate the β-galactosidase enzyme activity. Kinetic investigation revealed the mixed mode of inhibition. This inhibition strategy was extended to control the growth of methicillin-resistant Staphylococcus aureus. The internalization of the Pd(II) cage inside the bacteria was confirmed when bacterial solutions were incubated with curcumin loaded cage. The intrinsic green fluorescence of curcumin made the bacteria glow when put under an optical microscope. Furthermore, this curcumin loaded molecular cage shows an enhanced antibacterial activity. Thus, Pd^II₈ molecular cage is quite attractive due to its dual role as enzyme inhibitor and drug carrier.     

Evaluating the impact of service quality on the dynamics of customer satisfaction in the telecommunication industry of Jorhat,Assam

Telecommunication Systems - Service quality acts as an antecedent to customer satisfaction (CS). Evaluation of service quality in an enterprise is vital to improve productivity and increase CS....     

Design and acceptance test of compact planar monopole antenna for LTE smartphone considering SAR,TRP, and HAC values

Eight different types of compact multiband planar antennas are proposed in this work for covering several long‐term evaluation (LTE) and Wi‐Fi bands in a smartphone antenna design. Gradual inclusion of several sections of a radiator on an inexpensive FR4 substrate is presented for receiving multi‐LTE bands with a handset device. Along with the presently available LTE bands, this antenna design approach also includes upcoming LTE in unlicensed spectrum and LTE licensed‐assisted access. Various techniques such as partial ground, branch line slit, parasitic structure, and meandered lines are used to achieve desired resonant frequencies, bandwidth, matching, and miniaturization. The final type of eight antennas has been implemented in the real‐world mobile phone handset. The interaction between the mobile handset and the human phantom model has been analyzed at few specific frequencies for evaluating specific absorption rate (SAR) and total radiated power (TRP) in a simulated manner. The same type is also studied as a hearing aid compatibility (HAC)–supported wireless device. The simulated results show the SAR and HAC values are at the acceptance level for this proposed design. A prototype model is developed and few parameters are measured for validation.     

Rational Nanotoolbox with Theranostic Potential for Medicated Pro‐Regenerative Corneal Implants

Cornea diseases are a leading cause of blindness and the disease burden is exacerbated by the increasing shortage around the world for cadaveric donor corneas. Despite the advances in the field of regenerative medicine, successful transplantation of laboratory‐made artificial corneas is not fully realized in clinical practice. The causes of failure of such artificial corneal implants are multifactorial and include latent infections from viruses and other microbes, enzyme overexpression, implant degradation, extrusion or delayed epithelial regeneration. Therefore, there is an urgent unmet need for developing customized corneal implants to suit the host environment and counter the effects of inflammation or infection, which are able to track early signs of implant failure in situ. This work reports a nanotoolbox comprising tools for protection from infection, promotion of regeneration, and noninvasive monitoring of the in situ corneal environment. These nanosystems can be incorporated within pro‐regenerative biosynthetic implants, transforming them into theranostic devices, which are able to respond to biological changes following implantation.     

Design of a compact triple band antenna with independent frequency tuning for MIMO applications

In this article, a planar, low profile microstrip line‐fed triple band multiple input multiple output (MIMO) antenna is presented for WiMax (2.5/3.5/5.5 GHz)/WLAN (2.4/3.6/5.8 GHz) applications simultaneously. The single element of the MIMO antenna consists of (i) a rectangular split ring resonator (SRR), (ii) a stepped impedance resonator (SIR) inside the SRR and (iii) a slot on the SIR. Each of the resonators generates its own individual band and each band is independently tunable. The antenna exhibits three operating bands at 2.35‐2.85 GHz, 3.25‐3.90 GHz and 5.45‐5.65 GHz. Four antenna elements are used to design the proposed MIMO antenna. The simulated results are observed and reported in terms of S‐parameters, gain, radiation patterns, envelope correlation coefficient (ECC), diversity gain (DG), channel capacity loss (CCL) and total active reflection coefficient. ECC and CCL are within the acceptable range defined for 4G and 5G application standards. To validate the simulation results a prototype structure is fabricated and the measured results are compared with those obtained from the simulation.     

3D human action analysis and recognition through GLAC descriptor on 2D motion and static posture images

In this paper, we present an approach for identification of actions within depth action videos. First, we process the video to get motion history images (MHIs) and static history images (SHIs) corresponding to an action video based on the use of 3D Motion Trail Model (3DMTM). We then characterize the action video by extracting the Gradient Local Auto-Correlations (GLAC) features from the SHIs and the MHIs. The two sets of features i.e., GLAC features from MHIs and GLAC features from SHIs are concatenated to obtain a representation vector for action. Finally, we perform the classification on all the action samples by using the l2-regularized Collaborative Representation Classifier (l2-CRC) to recognize different human actions in an effective way. We perform evaluation of the proposed method on three action datasets, MSR-Action3D, DHA and UTD-MHAD. Through experimental results, we observe that the proposed method performs superior to other approaches.