Temperature Dependence Of The Electrical Resistivity Of LaxLu1-xAs

We investigate the temperature-dependent resistivity of single-crystalline films of LaxLu1-xAs over the 5-300 K range. The resistivity was separated into lattice, carrier and impurity scattering regions. The effect of impurity scattering is significant below 20 K, while carrier scattering dominates at 20-80 K and lattice scattering dominates above 80 K. All scattering regions show strong dependence on the La content of the films. While the resistivity of 600 nm LuAs films agree well with the reported bulk resistivity values, 3 nm films possessed significantly higher resistivity, suggesting that interfacial roughness significantly impacts the scattering of carriers at the nanoscale limit. (C) 2013 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.Microelectronics Research Cente

Production and Storage of Cassava Chips for Reconversion into Gari

Cassava chips (7% moisture level) produced from cassava root (IITA 94/0561) was stored for 6 months in high density polyethylene bag. Stored chips were coarse milled, rehydrated to 62.51% and seeded with fresh cassava mash (FCM) at levels of 5%, 10% and 20%. The resulting mash was fermented for 72 hr, with pH monitored every 24 hr, and processed to gari. Yield and swelling capacity of gari were determined. Sensory evaluation was carried out on water soaked gari and gari paste (‘eba’). While least values for pH was obtained in FCM throughout the fermentation period, there was reduction in values in all samples with increase in fermentation time from 30.01 to 33.40%. Yield of gari from the seeded chips ranged from 64.4-72.3%, while that of FCM was 18.7%. Swelling capacity of gari ranged from 2.0 - 3.0 in FCM and that seeded with 20% FCM, respectively. Sensory evaluation result revealed that gari produced from cassava chips seeded at 10% level is adequate for making ‘eba’ while that seeded at 5% level is adequate for consumption as soaked gari (p<0.05). Use of stored cassava chips with 10% FCM for gari production could be encouraged to reduce postharvest problem of cassava roots and the drudgery of gari processing. Keywords: Cassava chips, cassava mash, gari, ‘eba’, postharvest losses, storag

AMELIORATION OF ARSENIC-INDUCED TOXICITY BY ETHANOL LEAF EXTRACT OF PHYLLANTUS AMARUS LINN AND VITAMIN C IN MALE ALBINO RATS

The ameliorative effect of ethanol leaf extract of Phyllantus amarus (EEPA) and vitamin C in arsenic-induced toxicity was studied. Thirty-six (36) male albino rats divided into six groups of six (6) rats each were used for the study. Arsenic toxicity was induced in three of the groups by daily intake of 100 ppm of arsenic as Dimethylarsenate (DMA) in their drinking water.  Two of the arsenic-exposed groups were treated with 200 and 500 mg/kg bwt of EEPA and vitamin C respectively. The third group was not treated during arsenic exposure. The fourth and fifth groups were positive control for P. amarus and Vitamin C respectively, while another group served as the normal control. All treatments were done orally for six weeks. The effects of treatments on lipid profile, lipid peroxidation and liver function were thereafter studied. Increased levels of total cholesterol, LDL-cholesterol and malondialdehyde (MDA) were observed in plasma and lymphocytes of untreated arsenic-exposed rats compared to the control group. Arsenic increased total cholesterol and LDL-cholesterol concentrations, while triacylglycerol concentration was reduced significantly. Treatments with EEPA and Vitamin C however ameliorated the dyslipidemia observed in arsenic-exposed groups. Exposure to DMA increased plasma activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) of the animals, while plasma activity of ALT in rats treated with Vitamin C was not different compared to the control. Both treatments however, had no significant effect (p > 0.05) on the activity of plasma AST. P. amarus may therefore play a role in ameliorating arsenic-induced dyslipidemia in male albino rats.     &nbsp

Cryoablation of low-flow vascular malformations

PURPOSEWe aimed to evaluate the safety and effectiveness of cryoablation in the treatment of low-flow malformations, specifically venous malformation (VM) and fibroadipose vascular anomaly (FAVA).METHODSWe conducted a retrospective review of 11 consecutive patients with low-flow malformations (14 lesions; 9 VM, 5 FAVA), median lesion volume 10.8 cm3, (range, 1.8–55.6 cm3) with a median age of 19 years (range, 10–50 years) who underwent cryoablation to achieve symptomatic control. Average follow-up was at a median of 207 days postprocedure (range, 120–886 days). Indications for treatment included focal pain and swelling. Technical success was achieved if the cryoablation ice ball covered the region of the malformation that corresponded to the patient’s symptoms. Clinical success was considered complete if all symptoms resolved and partial if some symptoms persisted but did not necessitate further treatment.RESULTSThe technical success rate was 100%. At 1-month follow-up, 13 of 14 lesions (93%) had a complete response and one (7%) had a partial response. At 6-month follow-up 12 of 13 (92%) had a complete response and 1 (8%) had a partial response. A total of 6 patients underwent primary cryoablation. Out of 9 VM cases, 7 had prior sclerotherapy and 2 had primary cryoablation. Out of the 5 FAVA cases, 1 had prior sclerotherapy and the remaining 4 cases underwent primary cryoablation. There were 3 minor complications following cryoablation including 2 cases of skin blisters and 1 case of transient numbness. These complications resolved with conservative management.CONCLUSIONCryoablation is safe and effective in the treatment of low-flow vascular malformations, either after sclerotherapy or as primary treatment

Advancing PoC Devices for Early Disease Detection using Graphene-based Sensors

Early detection of diseases is key to better disease management and higher survival rates. It aims at discovering conditions that have already produced biochemical changes in body fluids, but have not yet reached a stage of apparent physical symptoms or medical emergency. Therefore, early disease detection relies majorly on biochemical testing of biological fluids such as serum, in the body. The laboratories for these tests require biochemical-based instrumentations that are bulky and not commonly available especially in developing countries. Moreover, the tests are expensive and require trained personnel to conduct and interpret results. On the other hand, Lab-on-a-Chip (LOC) biosensors have a potential to miniaturize the entire biochemical/laboratory methods of diagnostics into versatile, inexpensive and portable devices with great potential for low-cost Point-of-Care (POC) applications. They are capable of providing accurate and precise information on the measured health indices for sub-clinical level of diseases. Nanotechnology-inspired biosensors have further advantages of low limit of detection (required for early diagnosis), real-time analysis and lesser sample volume requirement. Of all other nanomaterials, graphene is said to be the most promising, suitable for biosensing due to its biocompatibility and consistent signal amplification even under the conditions of harsh ionic solutions found in the human body. This paper reviews the potentials, fundamental concepts and related works in using Graphene-based Field Effect Transistors (GFETs) as biosensors for early disease diagnosis. This paper also highlights a low-cost patterning mechanism for preparing SiO2/Si substrate for metal deposition (of the source and drain electrodes of FETs)

Effects of co-administered dexamethasone and diclofenac potassium on pain, swelling and trismus following third molar surgery

BACKGROUND: The apparent interactions between the mechanisms of action of non-steroidal anti-inflammatory drugs (NSAIDS) and steroids suggest that co-therapy may provide beneficial inflammatory and pain relief in the absence of side effects. The aim of the study was to compare the effect of co-administered dexamethasone and diclofenac potassium (diclofenac K) with diclofenac K alone on the postoperative pain, swelling and trismus after surgical removal of third molars. PATIENTS AND METHODS: A prospective randomized double-blind study was conducted at the Department of Oral and Maxillofacial Surgery, Lagos University Teaching Hospital, Nigeria. A total of 100 patients were randomly allocated to two treatment groups of dexamethasone (prophylactic 8 mg and postoperative 4 mg IV) and diclofenac K (50 mg Oral before and after surgery), and diclofenac K alone (as with first group). The overall analgesic efficacy of the drug combinations was assessed postoperatively by determination of pain intensity using a category rating scale. Facial swelling was measured using a tape measure placed from tragus to gonion to tragus, while interincisal mouth-opening of patients was measured using a vernier calibrated caliper pre-operatively and post-operatively. RESULTS: Co-administration of dexamethasone and diclofenac K was significantly superior to diclofenac alone for the relief of pain (P < 0.05), and facial swelling up to post-operative 48 hour (P < 0.05). However, there was no significant difference for trismus relief between the two medication protocols (P > 0.05). CONCLUSION: This study illustrates enhanced effects of co-administered dexamethasone and diclofenac K on short-term post-operative pain and swelling, compared to diclofenac potassium alone in third molar surgery

Technical aspects of CT imaging of the spine

This review article discusses technical aspects of computed tomography (CT) imaging of the spine. Patient positioning, and its influence on image quality and movement artefact, is discussed. Particular emphasis is placed on the choice of scan parameters and their relation to image quality and radiation burden to the patient. Strategies to reduce radiation burden and artefact from metal implants are outlined. Data acquisition, processing, image display and steps to reduce artefact are reviewed. CT imaging of the spine is put into context with other imaging modalities for specific clinical indications or problems. This review aims to review underlying principles for image acquisition and to provide a rough guide for clinical problems without being prescriptive. Individual practice will always vary and reflect differences in local experience, technical provisions and clinical requirements

Measuring femoral lesions despite CT metal artefacts: a cadaveric study

Objective Computed tomography is the modality of choice for measuring osteolysis but suffers from metal-induced artefacts obscuring periprosthetic tissues. Previous papers on metal artefact reduction (MAR) show qualitative improvements, but their algorithms have not found acceptance for clinical applications. We investigated to what extent metal artefacts interfere with the segmentation of lesions adjacent to a metal femoral implant and whether metal artefact reduction improves the manual segmentation of such lesions. Materials and methods We manually created 27 periprosthetic lesions in 10 human cadaver femora. We filled the lesions with a fibrotic interface tissue substitute. Each femur was fitted with a polished tapered cobalt-chrome prosthesis and imaged twice—once with the metal, and once with a substitute resin prosthesis inserted. Metalaffected CTs were processed using standard back-projection as well as projection interpolation (PI) MAR. Two experienced users segmented all lesions and compared segmentation accuracy. Results We achieved accurate delineation of periprosthetic lesions in the metal-free images. The presence of a metal implant led us to underestimate lesion volume and introduced geometrical errors in segmentation boundaries.MediamaticsElectrical Engineering, Mathematics and Computer Scienc

Supramolecular networks stabilise and functionalise black phosphorus

The limited stability of the surface of black phosphorus (BP) under atmospheric conditions is a significant constraint on the exploitation of this layered material and its few layer analogue, phosphorene, as an optoelectronic material. Here we show that supramolecular networks stabilised by hydrogen bonding can be formed on BP, and that these monolayer-thick films can passivate the BP surface and inhibit oxidation under ambient conditions. The supramolecular layers are formed by solution deposition and we use atomic force microscopy to obtain images of the BP surface and hexagonal supramolecular networks of trimesic acid and melamine cyanurate (CA.M) under ambient conditions. The CA.M network is aligned with rows of phosphorus atoms and forms large domains which passivate the BP surface for more than a month, and also provides a stable supramolecular platform for the sequential deposition of 1,2,4,5-tetrakis(4-carboxyphenyl)benzene to form supramolecular heterostructures