Discovery and Investigation of Mutase-like Activity in a Phenylalanine Ammonia Lyase from Anabaena variabilis

The effect of extended reaction times on the regio- and enantioselectivity of the phenylalanine ammonia lyase (PAL)-catalysed amination of a subset of cinnamate derivatives was investigated. This was done using a PAL from the cyanobacterium Anabaena variabilis and incubation in a concentrated ammonia buffer. Whilst early time point analyses revealed excellent selectivities to give mostly the well-documented (S)-α-amino acid products, subsequent accumulation of other regio-/stereo- isomers was seen. For many para-substituted substrates, the β-regioisomer, a previously-unreported product with this enzyme class, was found to become more abundant than the α-, after sufficient incubation, with slight preference for the (R)-enantiomer. Although attempts to tune the selectivity of the PAL toward any of the three side products were largely unsuccessful, the results provide insight into the evolutionary history of this class of enzymes and reinforce the prominence of the toolbox of specific and selective cinnamate-aminating enzymes

Polyaniline/palladium nanohybrids for moisture and hydrogen detection.

Palladium nanoparticles display fascinating electronic, optical and catalytic properties, thus they can be used for various applications such as sensor fabrication. Conducting polymers such as polyaniline have also been widely used in sensor technology due to its cost effectiveness, versatility, and ease of synthesis. In this research, attention was given to unify the exceptional properties of these two materials and construct palladium nanoparticle coated polyaniline films to detect hydrogen and moisture. Electrochemical polymerization of aniline was carried out on gold sputtered epoxy resin boards. Polyaniline film was generated across a gap of 0.2 mm created by a scratch made on the gold coating prior to electrochemical polymerization. A palladium nanoparticle dispersion was prepared using sonochemical reduction method and coated on to polyaniline film using drop-drying technique. Polyaniline only films were also fabricated for comparative analysis. Sensitivity of films towards humidity and hydrogen was evaluated using impedance spectroscopy in the presence of the respective species. According to the results, polyaniline films exhibited an impedance drop in the presence of humidity and the response was significantly improved once palladium nanoparticles were incorporated. Interestingly, polyaniline only films did not respond to hydrogen. Nevertheless, palladium nanoparticle coated polyaniline films exhibited remarkable response towards hydrogen

Lipid (per) oxidation in mitochondria:an emerging target in the ageing process?

Lipids are essential for physiological processes such as maintaining membrane integrity, providing a source of energy and acting as signalling molecules to control processes including cell proliferation, metabolism, inflammation and apoptosis. Disruption of lipid homeostasis can promote pathological changes that contribute towards biological ageing and age-related diseases. Several age-related diseases have been associated with altered lipid metabolism and an elevation in highly damaging lipid peroxidation products; the latter has been ascribed, at least in part, to mitochondrial dysfunction and elevated ROS formation. In addition, senescent cells, which are known to contribute significantly to age-related pathologies, are also associated with impaired mitochondrial function and changes in lipid metabolism. Therapeutic targeting of dysfunctional mitochondrial and pathological lipid metabolism is an emerging strategy for alleviating their negative impact during ageing and the progression to age-related diseases. Such therapies could include the use of drugs that prevent mitochondrial uncoupling, inhibit inflammatory lipid synthesis, modulate lipid transport or storage, reduce mitochondrial oxidative stress and eliminate senescent cells from tissues. In this review, we provide an overview of lipid structure and function, with emphasis on mitochondrial lipids and their potential for therapeutic targeting during ageing and age-related disease

Real time endoscope trajectory tracking in the 3D space using MEMS sensors

Colonoscopy is one of most widely used screening procedures conducted for detection colon cancers. Nevertheless, since the procedure is extremely uncomfortable, willingness to have a colonoscopy is very low. The endoscope looping, which is a common occurrence during colonoscopy procedures can cause severe pain to the patients. The detection of endoscope looping is difficult just from the feel of the endoscope, because of the endoscope stiffness and the high tension developed in the twisted endoscope inside the colon. The occurrence of Endoscope looping can be detected or prevented if the surgeon has sufficient spatial and orientation information of the endoscope. Hence, our goal is to develop a technique to track the three dimensional representation of the endoscope and develop a navigational aid for the surgeon to guide the colonoscopy. We used 8 inertial sensor systems, which are small enough to incorporate into the endoscope tube at predetermined locations. Then the firmware platform gathers data from these systems in real time. The data gathered from sensor systems are processed and fused to form a complete orientation description of sensor modules in 3D space. The processed orientation data is then sent to the PC and the Software application we developed interpolates the sent data in order to get the real time 3D visualization of the Endoscope. The developed prototype was tested using a model phantom. After testing for accuracy between the real shape and the calculated shape from our method we found out that the shape very closely resembles the real shape, quantitatively