UV-shielding antimicrobial zein films blended with essential oils for active food packaging

A comprehensive study on zein film blended with glycerol and essential oils (EOs) is presented in this work. In particular, ultra violet (UV) shielding property and antimicrobial efficacy of developed active zein films (ZF) are tested. The fabricated films show zero transmittance in the UV region as compare to commercial poly-film which shows 40%–80% of UV transmittance. Results show that films are effective against spoilage microorganisms. The incorporation of EOs in ZF significantly reduces the growth of microbes over fruit samples since day 3. Physical interactions existing between EOs along with glycerol and zein provide considerable barrier properties. The glass transition temperature of the film comes out to be 47.7°C having the tensile strength of 1.21 ± 0.05 MPa. TGA curves show major weight loss in the range of 220–375°C. In conclusion, edible active ZF can be used as healthy packages over food and drug to increase their shelf life.     

Broadband, lossless, dispersion-compensating asymmetrical twin-core fiber design with flat-gain Raman amplification

We report here a broadband, lossless, dispersion-compensating asymmetrical twin-core fiber design with flat-gain Raman amplification that uses a single pump. Simulations show that broadband Raman amplification, with +/- 0.1-dB gain ripple, is achievable over a 31-nm bandwidth (1504-1535 nm) by use of a single pump. Amplifier characteristics have been modeled, with the effects of wavelength-dependent splice and background attenuation loss taken into account. The fiber also has a high negative-dispersion coefficient [-230 to -330 ps/(km nm)] over the operating wavelength range and, hence, only 12.5 km of this fiber can compensate for an accumulated dispersion of 240 km of standard transmission fiber. The device is thus proposed as a lossless dispersion-compensating module wherein lossless operation is achieved by use of inherently gain-flattened Raman amplification.     

Design and analysis of an algorithm for fair service in error‐prone wireless channels

In order to support diverse communication‐intensive real‐time and non‐real‐time data flows over a scarce, varying and shared wireless channel with location‐dependent and bursty errors, we define a service model that has the following characteristics: short‐term fairness among flows which perceive a clean channel, long‐term fairness for flows with bounded channel error, worst‐case delay bounds for packets, short‐term throughput bounds for flows with clean channels and long‐term throughput bounds for all flows with bounded channel error, expanded schedulable region, and support for both delay sensitive and error sensitive data flows. We present the wireless fair service algorithm, and show through both analysis and simulation that it achieves the requirements of the service model in typical wireless network environments. The key aspects of the algorithm are the following: (a) an enhanced fair queueing based service scheme that supports decoupling of delay and bandwidth, (b) graceful service compensation for lagging flows and graceful service degradation for leading flows, (c) support for real‐time delay sensitive flows as well as non‐real‐time error sensitive flows, and (d) an implementation within the framework of the simple and robust CSMA/CA wireless medium access protocol. This revised version was published online in July 2006 with corrections to the Cover Date.     

Modes in optical waveguides formed by silver-sodium ion exchange

Exact solutions of the scalar wave equation for the guided modes of planar optical waveguides formed by silver-sodium ion exchange have been obtained. It has been shown that there is good agreement between the exact solution and the solution obtained by using the Wentzel-Kramer-Brillouin (WKB) approximation.     

Effects of miRNA-149-5p and Platelet-Activating Factor-Receptor Signaling on the Growth and Targeted Therapy Response on Lung Cancer Cells

Accumulating evidence indicates that microRNAs (miRs) play critical roles in essentially all biological processes and their altered expression has been documented in various disease conditions, including human malignancies. Although several cellular mechanisms have been identified in mediating the effects of miRs, the involvement of G-protein-coupled, platelet-activating factor-receptor (PAFR) signaling in miR-149-5p-induced effects on lung cancer growth and therapeutic potential has not been studied. To that end, we first evaluated the functional significance of PAFR and miR-149-5p in A549 and H1299 human non-small cell lung cancer (NSCLC) cell lines. We observed that these tumor lines express endogenous PAFR and miR-149-5p and that PAFR activation by PAF agonist (CPAF) significantly increased, whereas miR-149-5p mimic transfection inhibited cell proliferation in a dose-dependent manner. Interestingly, miR-149-5p mimic significantly attenuated CPAF-mediated increased proliferation of NSCLC cells, as confirmed by miR-149-5p, cyclin D1, and forkhead box protein M1 (FOXM1) expression analysis via qPCR. Our next studies examined PAFR- and miR-149-5p-mediated effects on targeted therapy (i.e., erlotinib and gefitinib) responses. We observed that erlotinib and gefitinib inhibited A549 and H1299 cell survival in a dose- and time-dependent manner, and CPAF significantly blocked this effect. These findings indicate that miR-149-5p blocks PAFR-mediated increased cell proliferation, and PAFR activation attenuates the cytotoxic effects of targeted therapy.     

The fate of human sperm-derived mtDNA in somatic cells

Inheritance of animal mtDNA is almost exclusively maternal, most likely because sperm-derived mitochondria are actively eliminated from the ovum, either at or soon after fertilization. How such elimination occurs is currently unknown. We asked whether similar behavior could be detected in somatic cells, by following the fate of mitochondria and mtDNAs after entry of human sperm into transformed cells containing mitochondria but lacking endogenous mtDNAs (rho0 cells). We found that a high proportion (10%-20%) of cells contained functioning sperm mitochondria soon after sperm entry. However, under selective conditions permitting only the survival of cells harboring functional mtDNAs, only approximately 1/10(5) cells containing sperm mitochondria survived and proliferated. These data imply that mitochondria in sperm can enter somatic cells relatively easily, but they also suggest that mechanisms exist to eliminate sperm-derived mtDNA from somatic cells, mechanisms perhaps similar to those presumed to operate in the fertilized oocyte.     

Ray analysis of parabolic-index segmented planar waveguides

A ray analysis of periodically segmented waveguides with parabolic-index variation in the high-index region is presented. We carried out the analysis using ray transfer matrices, which is convenient to implement and which can be extended to study different types of graded-index segmented waveguide. Results of this ray tracing approach clearly illustrate the waveguiding properties and the existence of stable and unstable regions of operation in segmented waveguides. We also illustrate the tapering action exhibited by segmented waveguides in which the duty cycle varies along the length of the waveguide. This analysis, although restricted to multimode structures, provides a clear visualization of the waveguiding properties in terms of ray propagation in segmented waveguides.