Shape‐memory bioresorbable terpolymer composite with antirestenotic drug

Shape‐memory polymers (SMPs) that combine shape‐memory, biodegradability, and controlled drug release properties are very promising for medical and pharmaceutical application. Moreover, incorporation of antirestenotic drug into SMP biodegradable stent seems to be an interesting solution because of possibility to combine the mechanical support that provides stent and also drug elution. The aim of our study was to analyze the effect of incorporation of sirolimus into poly(l ‐lactide‐co‐glycolide‐co‐trimethylene carbonate) on physicochemical and mechanical properties, degradation, and shape‐memory effect of the terpolymer. For this purpose, sirolimus was incorporated into the terpolymer by injection molding method. It has been demonstrated that drug‐free terpolymer after injection molding characterized insignificant changes in terpolymer composition. Degradation of materials during processing was not observed. Incorporation of drug molecules did not change shape‐memory properties of terpolymer. ¹H‐ and ¹³C‐NMR spectra of poly(lactide‐co‐glycolide‐co‐trimethylene carbonate) confirmed that changes during degradation were similar for terpolymer and terpolymer with sirolimus. Sustained and regular release of sirolimus was observed. The developed material presents potential for biomedical and pharmaceutical applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41902.     

Nanoparticles of Copper Stimulate Angiogenesis at Systemic and Molecular Level

Copper is a key element affecting blood vessel growth and muscle development. However, the ions released from Cu salts are toxic. Given their specific physicochemical properties, nanoparticles of Cu (NanoCu) may have different bioactivity and affect the development of blood vessel and muscles in a different manner than Cu salts. The objective of the study was to evaluate the influence of NanoCu on embryo development and angiogenesis at the systemic and molecular level, in experiments using a chick embryo model. Fertilized chicken eggs were divided into a control group, and groups injected with a placebo, CuSO₄ or NanoCu. Embryo development at the whole body level and molecular indices using an embryo chorioallantoic membrane model were measured during embryogenesis. The present study indicated for the first time that NanoCu have pro-angiogenic properties at the systemic level, to a greater degree than CuSO₄ salt. The properties of NanoCu were confirmed at the molecular level, demonstrating significant effects on mRNA concentration and on mRNA gene expression of all pro-angiogenic and pro-proliferative genes measured herein.     

Carborane‐Derived Local Anesthetics are Isomer Dependent

Clinically there is a need for local anesthetics with a greater specificity of action on target cells and longer duration. We have synthesized a series of local anesthetic derivatives we call boronicaines in which the aromatic phenyl ring of lidocaine was replaced with ortho‐, meta‐, C,C’‐dimethyl meta‐ and para‐carborane clusters. The boronicaine derivatives were tested for their analgesic activity and compared with lidocaine using standard procedures in mice following a plantar injection. The compounds differed in their analgesic activity in the following order: ortho‐carborane = C,C’‐dimethyl meta‐carborane > para‐carborane > lidocaine > meta‐carborane derivative. Both ortho‐boronicaine and C,C’‐dimethyl meta‐boronicaine had longer durations of analgesia than lidocaine. Differences in analgesic efficacies are rationalized by variations in chemical structure and protein binding characteristics.     

Generalized M-2M Mapping Scheme for SLM and PTS Based OFDM Systems Without Side-Information

Orthogonal frequency division multiplexing (OFDM) is an attractive multicarrier modulation scheme, but it suffers from the problem of high peak-to-average power ratio (PAPR). Selected mapping (SLM) and partial transmit sequences (PTS) are two well known, distortion-less techniques with good PAPR reduction capabilities. But, both the methods require side information (SI) about the phase rotation factors to recover the original data signal at the receiving end. The transmission of SI not only results in data rate loss but also, in BER performance degradation if SI gets corrupted over the channel. In this paper we have proposed a new mapping scheme, named “ $M\text{- }2M$ Mapping scheme” for SLM and PTS based methods to completely eliminate the requirement of SI at the receiver. In this scheme $M$ data points are mapped to the constellation points of 2M-ary modulation scheme using (1, j) as the phase rotation factors. Some criteria are suggested with which the method is applied for different constellation sizes, $M=4$ to $M=16$ . The method can be easily coupled with conventional SLM and PTS techniques. When compared with the existing methods like multi point square mapping, which do not need SI, our technique is scalable and provides good PAPR reduction capability with consistent BER performance.     

Ce-doped bismuth ferrite thin films with improved electrical and functional properties

Bi_1?xCe_xFeO₃ (BCFO) thin film capacitors (x = 0 to 0.2) are fabricated on indium tin oxide coated corning glass substrate by chemical solution deposition method. X-ray diffraction results show a partial phase transition from rhombohedral to tetragonal structure induced in BCFO thin film having preferred (110) orientation with increase in Ce dopant concentration. Current density–field (J–E) characteristics indicate that the leakage current density reduces by several orders of magnitude in Ce-doped BFO thin films resulting from smaller grain sizes and smoother surfaces. Space-charge-limited current and Fowler–Nordheim tunneling are identified as dominating leakage behavior in BCFO thin film capacitors at moderate and high field regions, respectively. Enhanced ferroelectric response with well-saturated (P–E) hysteresis loop is observed for Bi_0.88Ce_0.12FeO₃ thin film having high remnant polarization (P _r—127 µC/cm²) at an applied field of 1080 kV/cm. Bi_0.88Ce_0.12FeO₃ thin film exhibiting well-defined capacitance–field (C–E) butterfly loop with dielectric loss (tan δ—0.03) measured at 10 kHz suggested good ferroelectric properties with high tunability of about 88 %.     

ND++ – an extended IPv6 Neighbor Discovery protocol for enhanced stateless address autoconfiguration in MANETs

Recent trends in information and communications technologies are oriented toward the design of the Future Internet and the Internet of Things. While IPv6‐based mobile ad hoc networks (MANETs) are emerging as an important building block of these new technologies, it is necessary to come up with adequate self‐configuration capabilities allowing for seamless and automated configuration of addresses in mobile environment. The mechanisms of stateless address autoconfiguration proposed for IPv6 networks are supposed to automate some configuration steps; however, they would need to be aligned with the requirements imposed by MANET networks. Therefore, in this article, we present Neighbor Discovery ++ – an extended IPv6 Neighbor Discovery protocol for enhanced duplicate address detection in MANETs, which provides increased coverage of network nodes, while minimizing protocol overhead. It exploits efficient flooding mechanism on the basis of the multipoint relay concept, which makes it an interesting approach also for large‐scale networks. Trials performed on the designated real‐world testbed platform indicate that ND++ is a promising solution to support efficient address autoconfiguration in MANETs. Copyright © 2012 John Wiley & Sons, Ltd.     

Behavioural analysis of a hydroelectric production power plant under reworking scheme

By high calibre of the fundamental nature of electric power, both of our economic and personal interests, a system is expected to supply as electrical energy as possible with the highest degree of quality and reliability. This research work aimed to evaluate the reliability measures of a hydroelectric power station. The results of this study are deliberate to provide the improved criteria for upcoming proposals, and serves as a basis for generation expansion planning of hydroelectric power stations. This paper presents a Markov-process based mathematical model for a hydroelectric power plant. The important reliability measures have been derived and discussed with the help of failure and repair rates through the analysis. This research gives a clear view of how the hydropower plants are modelled by defining the states under the failure and repair rates.