Simultaneous determination of methylcarbamate and ethylcarbamate in fermented foods and beverages by derivatization and GC-MS analysis

BACKGROUND: Methylcarbamate (MC) and ethylcarbamate (EC) are toxic compounds that commonly exist in fermented food and beverages. In order to estimate the risk for their exposure, a sensitive simultaneous analytical method is required RESULTS: A simultaneous determination of MC and EC was described based on derivatization with 9-xanthydrol and consecutive detection using gas chromatography–mass spectrometry. The derivatization of MC and EC was performed directly in food or beverages and the reaction conditions were established through changing various parameters. The detection and the quantification limits were 0.01-0.03 μg/kg and 0.03-0.1 μg/kg, respectively, and the interday relative standard deviation was less than 12% at concentrations of 2.0 and 50 μg/kg. MC and EC were measured from 0.4 μg/kg to 85.8 μg/kg in sixteen Korean fermented foods and eleven beverages. CONCLUSION: A simple, sensitive method to detect MC and EC in several solid foods and liquid foods was developed based on derivatization with 9-xanthydrol for 10 min at an ambient temperature. The method may useful for routine analysis of MC and EC in numerous food samples

The Remaining Refractory Thickness Assessment of Hearth Part in the Blast Furnace

In the steel industry, the blast furnace is a process for making molten iron by melting iron ore. The blast furnace body is a huge structure of 50m in height, 20m in width. It should be operated not less than 15 years during one campaign. The structural problems of this blast furnace are cracks of the steel shell and thickness reductions of the stave and the refractory of hearth part caused by wear. Among them the thickness reduction of the hearth refractory in the blast furnace is very important factor in determining the dismantlement and the reconstruction of the blast furnace. Conventionally, the thermal model was used to estimate the residual thickness and to monitor the temperature of refractory with thermocouples installed on the refractory. Recently, Impact Echo method is being applied to measure the residual thicknesses of concrete or nonmetallic stiff structures. The method should be accompanied with verification in the actual blast furnace since there are differences in the reflection characteristics of the ultrasonic velocity depending on physical parameters of the steel shell, the refractory and ramming part between the steel shell and the refractory such as the size, the shape, the temperature, the consisting materials and etc. In this study, we compared various sensors such as accelerometer, a microphone and an ultrasonic sensor and the experimental methods in determining the ultrasonic velocity of the anisotropic refractory material. In addition, measuring refractory thickness of the actual blast furnace was carried out before dismantling and verified with exact thickness of refractory by means of measuring length of the core-boring sample and dismantling investigatio

Efficient aimpoint tracking using target range profiles of a wideband FMCW seeker

This paper proposes an efficient aimpoint tracking filter for high-range resolution FMCW radar seekers. A modified probabilistic data association scheme is devised to deal with closely located measurements generated by scatterers of an extended target and multipath clutter. In order to discriminate the aimpoint measurement from others, an approximate target range profile is used for calculating likelihoods of the validated measurements. Simulation results show the effectiveness and the superior performance of the proposed approach

A Case Study of Characteristics of Damages Caused by Typhoon EWINIAR 2006 in South Korea

During recent years, the climate of Korea has clearly been divided between dry season and rainy season due to the global warming and other reasons, and a record breaking rain is falling every year. The mountain slopes in Korea receives significant damage generally during the seasons of high rain front and typhoon. In 2006, the rainy season started in July and Typhoon EWINIAR which hit South Korea between July 26 and 28 caused significant damage to various slopes and roads. This paper presents a case study of the damages and characteristics of the damages to cut slopes, fill slopes, and roads caused by the concentrated heavy rains for 3 days in the regions of Inje and YangYang

A Novel Mechanism of PPARγ Regulation of TGFβ1: Implication in Cancer Biology

Peroxisome proliferator-activated receptor-γ (PPARγ) and retinoic acid X-receptor (RXR) heterodimer, which regulates cell growth and differentiation, represses the TGFβ1 gene that encodes for the protein involved in cancer biology. This review will introduce the novel mechanism associated with the inhibition of the TGFβ1 gene by PPARγ activation, which regulates the dephosphorylation of Zf9 transcription factor. Pharmacological manipulation of TGFβ1 by PPARγ activators can be applied for treating TGFβ1-induced pathophysiologic disorders such as cancer metastasis and fibrosis. In this article, we will discuss the opposing effects of TGFβ on tumor growth and metastasis, and address the signaling pathways regulated by PPARγ for tumor progression and suppression

Hypertensive brainstem encephalopathy involving deep supratentorial regions: does only blood pressure matter?

We report on a 42-year-old female patient who presented with high arterial blood pressure of 245/150 mmHg and hypertensive brainstem encephalopathy that involved the brainstem and extensive supratentorial deep gray and white matter. The lesions were nearly completely resolved several days after stabilization of the arterial blood pressure. Normal diffusion-weighted imaging findings and high apparent diffusion coefficient values suggested that the main pathomechanism was vasogenic edema owing to severe hypertension. On the basis of a literature review, the absolute value of blood pressure or whether the patient can control his/her blood pressure seems not to be associated with the degree of the lesions evident on magnetic resonance imaging. It remains to be determined if the acceleration rate and the duration of elevated arterial blood pressure might play a key role in the development of the hypertensive encephalopathy pattern

EFFECTS OF MO, CR, AND V ADDITIONS ON TENSILE AND CHARPY IMPACT PROPERTIES OF API X80 PIPELINE STEELS

In this study, four API X80 pipeline steels were fabricated by varying Mo, Cr, and V additions, and their microstructures and crystallographic orientations were analyzed to investigate the effects of their alloying compositions on tensile properties and Charpy impact properties. Because additions of Mo and V promoted the formation of fine acicular ferrite (AF) and granular bainite (GB) while prohibiting the formation of coarse GB, they increased the strength and upper-shelf energy (USE) and decreased the energy transition temperature (ETT). The addition of Cr promoted the formation of coarse GB and hard secondary phases, thereby leading to an increased effective grain size, ETT, and strength, and a decreased USE. The addition of V resulted in a higher strength, a higher USE, a smaller effective grain size, and a lower ETT, because it promoted the formation of fine and homogeneous of AF and GB. The steel that contains 0.3 wt pct Mo and 0.06 wt pct V without Cr had the highest USE and the lowest ETT, because its microstructure was composed of fine AF and GB while its maintained excellent tensile properties.X1126sciescopu