Gamma radiation-induced nanodefects in diffusive memristors and artificial neurons.

Gamma photons with an average energy of 1.25 MeV are well-known to generate large amounts of defects in semiconductor electronic devices. Here we investigate the novel effect of gamma radiation on diffusive memristors based on metallic silver nanoparticles dispersed in a dielectric matrix of silica. Our experimental findings show that after exposure to radiation, the memristors and artificial neurons made of them demonstrate much better performance in terms of stable volatile resistive switching and higher spiking frequencies, respectively, compared to the pristine samples. At the same time we observe partial oxidation of silver and reduction of silicon within the switching silica layer. We propose nanoinclusions of reduced silicon distributed across the silica layer to be the backbone for metallic nanoparticles to form conductive filaments, as supported by our theoretical simulations of radiation-induced changes in the diffusion process. Our findings propose a new opportunity to engineer the required characteristics of diffusive memristors in order to emulate biological neurons and develop bio-inspired computational technology.

Multilevel information storage using magnetoelastic layer stacks.

The use of voltages to control magnetisation via the inverse magnetostriction effect in piezoelectric/ferromagnet heterostructures holds promise for ultra-low energy information storage technologies. Epitaxial galfenol, an alloy of iron and gallium, has been shown to be a highly suitable material for such devices because it possesses biaxial anisotropy and large magnetostriction. Here we experimentally investigate the properties of galfenol/spacer/galfenol structures in which the compositions of the galfenol layers are varied in order to produce different strengths of the magnetic anisotropy and magnetostriction constants. Based upon these layers, we propose and simulate the operation of an information storage device that can operate as an energy efficient multilevel memory cell.

Development of an autonomic portable single-board computer based high resolution NIRS device for microcirculation analysis.

Near Infrared Spectroscopy (NIRS) is a wellestablished non-invasive technique for measuring metabolic changes in biological tissue. In this paper we describe the design and development of an autonomic portable single board computer based high resolution NIRS device, which allows quantification of these changes. The sensor-patch consisting of 8LEDs and 2photo-detectorsprovides8 channels for each detector, offering increased depth resolution for monitoring microcirculatory activity..NIRS data is acquired with a sampling rate of about 2Hz per channel using the data acquisition board which consists of a 16 bit ADC, a LED driver and programmable gain amplifiers. The components on the data acquisition board are controlled via the Advantech's PCM-3355L SBC based on Windows XP platform. The software was created using Visual Basic 6.0 and Microsoft Visual C++ 6.0. It offers optionally a real time 'monitoring' and a static data (offline) visualization mode. The most unique feature of the system is its ability to auto-calibrate itself i.e. Adopt the intensity of the LEDs output light to different experimental conditions, e.g. local melanin content, density of the tissue, and emitter-detector distances. To validate the device various experiments have been carried out such as measurements on resting and working gastrocnemius and biceps muscle in ambulatory situations. The achieved results confirmed adequate performance and reliability of the device.

Pleural empyema due to S. typhi: a case report.

In a 35 year old immunocompetent male, clinically diagnosed as a case of hydropneumothorax of left side, Salmonella typhi was isolated as the causative agent of pleural empyema.

Bacterial endocarditis due to Eikenella corrodens: a case report.

Of all the causes of bacterial endocarditis, HACEK group consisting of Haemophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella Kingae are rare causative agents. We report a case of bacterial endocarditis by E. corrodens, which is one of the members of the HACEK group.

Enterobacter cloacae: a predominant pathogen in neonatal septicaemia.

A total of 120 blood samples from neonates presenting with clinical signs of septicaemia were subjected for culture using brain heart infusion agar biphasic medium (BHI BPM) and glucose broth. Bacterial agents were isolated from 48 numbers (40%) of cultures. Gram-negative bacilli were isolated in maximum percentage (88.45%) of cases whereas gram-positive bacteria (coagulase negative staphylococci and group B streptococci) in 11.6% of cultures. E. cloacae (39.5%) was maximally isolated among the pathogenic bacteria followed by K. pneumoniae (23.2%), E. coli (11.6%) and others like Acinetobacter spp. (6.9%), Citrobacter freundi (4.6%) and P. mirabillis (2.3%). All the gram-negative bacilli isolates showed 100% susceptibility to amikacin, whereas 85% of E. cloacae isolates were sensitive to the same. Thus E. cloacae was found to be a predominant moderately sensitive pathogen in neonatal septicemia.