Electrospun Janus nanofibers loaded with a drug and inorganic nanoparticles as an effective antibacterial wound dressing

The most important property of a wound dressing is its anti-bacteria performance. Although electrospun nanofibers are frequently demonstrated to be potent candidates as wound dressings, no Janus fibers have been explored for this popular application. In this study, a Janus wound dressing composed of polyvinylpyrrolidone (PVP) and ethyl cellulose (EC) polymer matrices was prepared via a side-by-side electrospinning process, in which ciprofloxacin (CIP) and silver nanoparticles (AgNPs) were loaded in the two sides. A homemade acentric spinneret was exploited to maintain a continuous preparation process. Scanning and transmission electron microscope results demonstrated that the Janus fibers had a uniform and cylindrical morphology with a clear Janus structure, and AgNPs distributed in one side. X-ray diffraction patterns suggested that drug was present in the fibers in an amorphous state owing to rapid drying and its good compatibility with PVP, which was verified by infrared spectroscopy. In vitro tests showed that over 90% of CIP was released within the first 30 min, ensuring a strong antibacterial effect at the initial stages of wound healing. The Janus fibers were demonstrated to have good bactericidal activity against the growth of both Gram-positive S. aureus and Gram-negative E. coli. The PVP-CIP/EC-AgNPs Janus fibers could thus be a promising candidate for effective wound dressings. This work paves a new way for creating Janus structure-based advanced functional nanomaterials

Improving the economic value of photographic screening for optical coherence tomography-detectable macular oedema : a prospective, multicentre, UK study

Peer reviewedPublisher PD

Towards a higher plane of air transportation security: from hubris to knowledge

Security—in air transportation is an issue of global importance. Since September 11, 2001 there have been numerous events where terrorists have successfully exploited vulnerabilities and weakness in the security system. The authors, both security practitioners and academics—contribute to the discussion of what security in air transportation means—by proposing that the existing system still remains vulnerable to future exploitation by terrorists and other threat groups. The essay proffers a framing device. The meaning of security is considered in terms of our knowledge of the system. It considers air transportation security from the position that our knowledge and understanding is limited by hubris; and explains how this can be improved so that system vulnerabilities are revealed and mitigated against before they are exploited. The essay concerns itself with the notion that air transportation security has a multitude of meanings, and that the system is in a critical state because it is perpetually reliant upon sophisticated technologies to retrospectively plug gaps in the defences. The essay concludes that complexity and hubris create a malign condition—which is not visible to lawmakers, regulators and system designers. And, to improve our understanding of what effective security means we need to look behind the hubristic curtain and grapple with the complexities and vagaries, which are the ingredients to the creation and incubation of system vulnerability and weakness

Endoplasmic reticulum chaperone prolyl 4-hydroxylase, beta polypeptide (P4HB) promotes malignant phenotypes in glioma via MAPK signaling

published_or_final_versio

Observations of trace gases and aerosols over the Indian Ocean during the monsoon transition period

Characteristics of trace gases (O3, CO, CO2, CH4 and N2O) and aerosols (particle size of 2.5 micron) were studied over the Arabian Sea, equatorial Indian Ocean and southwest part of the Bay of Bengal during the monsoon transition period (October-November, 2004). Flow of pollutants is expected from south and southeast Asia during the monsoonal transition period due to the patterns of wind flow which are different from the monsoon period. This is the first detailed report on aerosols and trace gases during the sampled period as the earlier Bay of Bengal Experiment (BOBMEX), Arabian Sea Monsoon Experiment (ARMEX) and Indian Ocean Experiments (INDOEX) were during monsoon seasons. The significant observations during the transition period include: (i) low ozone concentration of the order of 5 ppbv around the equator, (ii) high concentrations of CO2, CH4 and N2O and (iii) variations in PM2.5 of 5-20μg/m3