Osteosclerosis due to endemic fluorosis

Endemic water borne fluorosis is a public health problem in Isparta, a city located in southern Turkey. In order to investigate the association between osteosclerosis and fluorosis, we retrospectively screened the results of lumbar spine and femur neck bone mineral density (BMD) of 1500 patients who were examined before, for any reason in between 2001-2003. Sixty nine patients (67 females and 2 males, mean age 52.6+/-10.2) with vertebra T-scores>or=+2 were found only except a patient with osteoid osteoma in the femur neck (femur T-score+6.64). Thirty-four of the patients could be reexamined with lateral vertebra BMD and investigated for fluorosis and the other etiologic causes of osteosclerosis. Of 34 patients, 14 had either mottled tooth enamel or urine fluoride level greater than 1.5 mg/l. Other etiologic causes were hypothyroidism (2), hypoparathyroidism (1), history of lumbar fracture (1), use of retinoids (1), vitamin D (7), oral calcium preparations (9), and bisphosphanates (3). Lateral lumbar vertebral T-score was greater than+2 in 12 patients (35.3%). Femur T-score was greater than+2 in 7 patients (20.6%). Fourteen patients (41.2%) had lateral vertebral or femur T-score>or=+2. Five (35.7%) of these patients had signs of fluorosis, as discussed before. Mean body mass index of individuals with fluorosis was 36.4+/-7.9 and this result was significantly higher than other osteosclerotic subjects (31.6+/-4.4). In conclusion we believe that approximately one third of the osteosclerosis in our region was due to endemic skeletal fluorosis and obesity may enhance this osteosclerotic type bone changes in endemic fluorosis.     

Numerical and Optical Analysis of Solar Power Level Adaptable Solar Reactor

Solar energy is an abundant renewable energy resource that can be used to provide high process heat necessary to run thermochemical processes for production of various solar fuels and commodities. In a solar reactor, sunlight is concentrated into a receiver through a small opening called the aperture. However, obtaining and maintaining semiconstant high temperatures inside a solar reactor is a challenge. This is because the incident solar radiation can fluctuate depending on the position of the sun and the weather conditions. For fixed aperture size reactors, changes in incident solar flux directly affect the temperature inside the reactor. This paper presents a novel solar reactor with variable aperture mechanism that is designed and manufactured at our lab. Radiation heat transfer analysis of this reactor concept is studied via Monte Carlo (MC) ray tracing. MC ray tracing module is coupled to a steady-state one-dimensional energy equation solver. Energy equation is solved for the wall and gas, accounting for the absorption, emission, and convection. Incoming direct flux values for a typical day are obtained from National Renewable Energy Lab database. Results show that for a perfectly insulated reactor, the average temperature of the working fluid may be kept appreciably constant throughout the day if aperture diameter is varied between 3 cm and 1.5 cm for incoming fluxes starting with 400 W/m² at 05:12 a.m., reaching peak value of 981 W/m² at noon, and eventually receiving 400 W/m² at 6:58 p.m., which can make the solar reactor run about 13 hr continuously at 1500 K semiconstant temperature.     

A review on conversion of triglycerides to on‐specification diesel fuels without additional inputs

Dependence on fossil fuels for global energy supply has continued to generate concerns about climate change and sustainable development. It has motivated the search for carbon‐neutral alternative resources for the production of transportation fuels to replace crude oil. Although biodiesels have recently emerged as a close substitute to petrol diesel, their use in compression ignition engines designed to run on petro‐diesel fuels are linked to adverse effects on the engines' performance and life span. This informed efforts at upgrading biodiesel or direct conversion of triglycerides to hydrocarbon mixtures that are identical or similar to that of petro‐diesel through hydrodeoxygenation. Moreover, it seems that commercial methods for the conversion of triglycerides to diesel fuels depends on inputs (methanol and hydrogen) derived from fossil fuels. However, it will be desirable to do so without inputs from fossil fuels. Hence, reaction paths for direct conversion of triglycerides to on‐specification hydrocarbons fuels without hydrogen gas input are discussed and suggested strategies are in cognisance of green chemistry principles. Copyright © 2012 John Wiley & Sons, Ltd.     

The Prevention of Oil and Chemical Pollution: Proactive Approaches in the UK and Canada

In the UK, various initiatives have been launched in an attempt to provide guidance on the occurrence and avoidance of oil and chemical pollution. Despite these efforts, oil and chemicals remain a major cause of pollution. In Canada, similar initiatives have been more successful due to a participative approach to campaign development and implementation. This paper compares UK and Canadian initiatives and identifies factors which led to the success of the Canadian campaigns.     

Characterization of cryogenic heat treated Vanadis 4 PM cold work tool steel

The amount of retained austenite in the quenched cold work tool steel sample is 17.7%, in the condition of sub-zero heat treated and double tempered samples following by quenching is 1.9% determined by XRD analysis. The types of carbides (MC, M₇C₃, M₂₃C₆) present in the structure was determined by XRD and SEM-EDS analysis. The hardness of test samples were 865 HV(0.1) for quenched sample and 785 HV(0.1) forth sample subjected to sub-zero treatment and double tempered after the quenching.     

Comparison of performance and emissions of diesel fuel,rapeseed and soybean oil methyl esters injected at different pressures

Fuel properties of rapeseed oil and soybean oil methyl esters (e.g. density, cetane number and viscosity etc.) are similar to those of the diesel fuel. These methyl esters can be used as diesel engine fuel by mixing withy diesel fuel. In this study a comparison of diesel fuel, the rapeseed oil methyl ester and the soybean oil methyl ester was made from the engine performance and emissions point of view. The tests were carried out with a four-cylinder diesel engine for tree different injection pressures such as 250, 300 and 350 bar with each of these fuels. For the purpose of comparison, tests were also conducted at full load conditions with diesel fuel. As the result, the performance and emission values of rapeseed oil (R) and soybean oil (S) methyl esters were found to be nearly the same with those of diesel fuels (D) when injection pressure was increased to 300 bar.     

Cellular uptake properties of a 2''-amino/2''-O-methyl-modified chimeric hammerhead ribozyme targeted to the epidermal growth factor receptor mRNA

PURPOSE: Rhabdomyosarcomas (RMS) are heterogeneous in their clinical presentation, histology, and cytogenetics. The growth of some RMS cells has been found to be regulated by the tyrosine kinase insulin-like growth factor (IGF) type I receptor. However, RMS cells exhibit variable sensitivity to inhibitors of tyrosine kinases and IGF receptors. Collectively, these heterogeneous features suggest that differences exist in the growth regulatory pathways of RMS. The objective of this study is to identify active tyrosine kinase signal transduction pathways in embryonal and alveolar RMS cells. METHODS: RMS tumor samples and cell lines representing both embryonal and alveolar histologic subtypes have been analyzed by immunoprecipitation and immunoblotting techniques to characterize phosphotyrosyl protein patterns and to identify tyrosine phosphorylated proteins. RESULTS: RMS cells can be characterized based on the patterns of phosphotyrosyl proteins, including the phosphorylation status of the catenin-like protein Cas1 and the signal adapter protein SHC, and the activation of IGF type I receptor signaling cascades including the formation of SHC-GRB2 signal protein complexes and MAP kinase activation. CONCLUSIONS: Rhabdomyosarcomas, especially the embryonal histologic subtype, are heterogeneous at the level of tyrosine kinase signal transduction. It will be important to characterize the growth regulatory pathways active in individual RMS tumors before targeting molecular therapies to this malignancy.     

A 21-mW 8-b 125-MSample/s ADC in 0.09-mm/sup 2/ 0.13-/spl mu/m CMOS

This paper presents an 8-b two-step subranging analog-to-digital (ADC) using interpolation, averaging, offset compensation, and pipelining techniques to accomplish an effective number of bits of 7.6 b at 125 MSample/s. The 0.13-/spl mu/m CMOS ADC occupies 0.09 mm/sup 2/ and consumes 21 mW.