Decreased JH biosynthesis is related to precocious metamorphosis in recessive trimolter (rt) mutants of the silkworm, Bombyx mori.

In recessive trimolter (rt) mutants of the silkworm, Bombyx mori, that have four larval instars rather than five larval instars of normal B. mori, a decrease after a small increase in the hemolymph ecdysteroid titer during the early stages of the last (fourth) larval instar appeared to be a prerequisite for larvae to undergo precocious metamorphosis. The present study was carried out to investigate the possible mechanism underlying this decrease in the ecdysteroid titer. It was found that juvenile hormone (JH) biosynthetic activity of the corpora allata (CA) increased during the first day of the last larval instar, but its absolute JH biosynthesis activity was relatively lower compared to that of normal fourth-instar larvae in tetramolters. This lowered JH biosynthetic activity appeared to be related to a decrease in prothoracic gland ecdysteroidogenesis during the second day of the last instar, because hydroprene application prevented this decrease in prothoracic gland ecdysteroidogenesis, leading to the induction of a supernumerary larval molt. The in vitro incubation of prothoracic glands with hydroprene showed that hydroprene did not directly exert its action on prothoracicotropic hormone (PTTH) release. Further study showed that the application of hydroprene enhanced the competency of the glands to respond to PTTH. From these results, it was supposed that the lowered JH biosynthesis of the CA during the first day of last instar in rt mutants was related to decreased ecdysteroidogenesis in the prothoracic glands during the second day, thus playing a role in leading to precocious metamorphosis.

Non-invasive survey technology for estimating the distribution of oxidant solution: A pilot injection study.

In-situ chemical oxidation (ISCO) can remove pollutants efficiently. However, the most important key to successfully conducting ISCO on site is to place the oxidant in close contact with the contaminant. Therefore, monitoring tools that provide for enhanced tracking of the injectate offer considerable benefit to guide subsequent ISCO injections. In this study, we applied the MagnetoMetric Resistivity (MMR) method to survey the distribution of an injected oxidant. A pilot test was conducted on a 10 m × 10 m site, and the sodium persulfate injection involved four pulse injections from one injection well. A magnetic field survey coupled with conventional monitoring was performed before the initial injection and after each pulse injection. The results of this study showed that groundwater samples from six observation wells and seven direct-push EC loggings did not provide sufficient data to quantify the distribution and flow behavior of the injected oxidant. However, the magnetic field survey visually showed the dynamic distribution of the injected oxidant, and the flow pathways and flow behavior were assessed accordingly. Although the flow behavior of injected solution was changeable in the aquifer, but the magnetic field survey combined with the monitoring of the well samples helped to explain the abnormal changes in the electrical conductivity of the observation wells and supports the use of the magnetic field survey technology as a method of monitoring ISCO injections.

Involvement of 4E-BP phosphorylation in embryonic development of the silkworm, Bombyx mori.

Phosphorylation of the translational repressor 4E-binding protein (4E-BP) plays a critical role in regulating the overall translation levels in cells. In the present study, we investigated 4E-BP phosphorylation of Bombyx mori eggs by an immunoblot analysis of a conserved phospho-specific antibody to 4E-BP and demonstrated its role during embryonic development. When HCl treatment was applied to diapause-destined eggs at 20 h after oviposition, a dramatic increase in the phosphorylation of 4E-BP occurred 5 min after treatment with HCl, and high phosphorylation levels were maintained throughout embryonic stage in HCl-treated eggs compared to those in diapause (control) eggs. When HCl treatment was applied to diapause eggs on day 10 after oviposition, no dramatic activation in 4E-BP phosphorylation occurred, indicating stage-specific effects of HCl treatment. In both non-diapause eggs and eggs whose diapause had been terminated by chilling of diapausing eggs at 5°C for 70 days and then were transferred to 25°C, high phosphorylation levels of 4E-BP were also detected. Moreover, 4E-BP phosphorylation dramatically increased when dechorionated eggs were incubated in medium. The addition of rapamycin, a specific inhibitor of mammalian target of rapamycin (TOR) signaling, and LY294002, a phosphoinositide 3-kinase (PI3K) inhibitor, but not the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor, U0126, dose-dependently inhibited 4E-BP phosphorylation in dechorionated eggs, indicating that PI3K/TOR signaling is an upstream signaling event involved in 4E-BP phosphorylation. Examination of 4E-BP gene expression levels showed no differences between treatments with HCl and water in the first hour after treatment, indicating that changes in phosphorylation of 4E-BP upon HCl treatment are mainly regulated at the post-transcriptional level. In addition, MAPK pathways and glycogen synthase kinase (GSK)-3ß phosphorylation were not significantly affected in the first hour after HCl treatment. These results demonstrate that the rapid phosphorylation of 4E-BP is an early signaling event in embryonic development in the eggs whose diapause initiation was prevented by HCl treatment, thus being involved in the embryonic development of B. mori.

Determination of sulfonamides in swine muscle after salting-out assisted liquid extraction with acetonitrile coupled with back-extraction by a water/acetonitrile/dichloromethane ternary component system prior to high-performance liquid chromatography.

A salting-out assisted liquid extraction coupled with back-extraction by a water/acetonitrile/dichloromethane ternary component system combined with high-performance liquid chromatography with diode-array detection (HPLC-DAD) was developed for the extraction and determination of sulfonamides in solid tissue samples. After the homogenization of the swine muscle with acetonitrile and salt-promoted partitioning, an aliquot of 1 mL of the acetonitrile extract containing a small amount of dichloromethane (250-400 microL) was alkalinized with diethylamine. The clear organic extract obtained by centrifugation was used as a donor phase and then a small amount of water (40-55 microL) could be used as an acceptor phase to back-extract the analytes in the water/acetonitrile/dichloromethane ternary component system. In the back-extraction procedure, after mixing and centrifuging, the sedimented phase would be water and could be withdrawn easily into a microsyringe and directly injected into the HPLC system. Under the optimal conditions, recoveries were determined for swine muscle fortified at 10 ng/g and quantification was achieved by matrix-matched calibration. The calibration curves of five sulfonamides showed linearity with the coefficient of estimation above 0.998. Relative recoveries for the analytes were all from 96.5 to 109.2% with relative standard deviation of 2.7-4.0%. Preconcentration factors ranged from 16.8 to 30.6 for 1 mL of the acetonitrile extract. Limits of detection ranged from 0.2 to 1.0 ng/g.

Application of sugaring-out extraction for the determination of sulfonamides in honey by high-performance liquid chromatography with fluorescence detection.

A simple sugaring-out assisted liquid-liquid extraction method combined with high-performance liquid-chromatography with fluorescence detection (HPLC-FL) was developed for the extraction and determination of sulfonamides in honey. Sample preparation consisted of acid hydrolysis to release sugar-bound sulfonamides. After derivatization with fluorescamine, the derivatives were partitioned into the organic layer under the honey (sugar)/water/acetonitrile system. The clear organic extract obtained by centrifugation could be injected into the HPLC system either directly or after dilution. Linearity was obtained with the coefficient of determination (R(2)) higher than 0.998 from 2 to 200 ng/mL. Under the optimal conditions, recoveries were determined for honey fortified at three levels (5, 20, and 100 ng/g) were 80.9-99.6% with coefficients of variation of 0.3-4.4%. Limits of detection for the sulfonamides studied were found to range from 0.6 to 0.9 ng/g.

Determination of tetracyclines in surface water and milk by the magnesium hydroxide coprecipitation method.

A simple coprecipitation method was developed for the determination of tetracyclines (TCs) in surface water and milk by high-performance liquid chromatography with diode-array detection (HPLC-DAD). Magnesium ion was added into the surface water or the acetonitrile (MeCN) extract of milk. After alkalinization, magnesium hydroxide precipitates which had been formed can be separated from the matrix solution easily by centrifuging and then a dissolution step was performed by adding a small amount of acid. The final solution could be introduced directly into HPLC system for the determination of the analytes. Under optimal conditions, recoveries for the analysis of spiked surface water samples ranged from 83.6% to 95.1% with relative standard deviation of 2.0-5.5%. For milk samples, relative recoveries were 95.9-104.6% with relative standard deviation of 3.4-6.7%. The enrichment factors ranged from 41.5 to 48.1 for 10 mL water samples, and from 3.6 to 4.4 for 1 mL MeCN extracts of milk. Limits of detection ranged from 0.13 to 0.51 ng/mL, and from 3.0 to 8.5 ng/g for four TCs in surface water and milk samples, respectively.

Dispersive solid-phase microextraction method for sample extraction in the analysis of four tetracyclines in water and milk samples by high-performance liquid chromatography with diode-array detection.

A dispersive solid-phase microextraction (dispersive-SPME) method for the determination of tetracycline, oxytetracycline, chlortetracycline and doxycycline is proposed. Different silica-based and polymeric sorbents were evaluated for their capacity to simultaneously preconcentrate tetracyclines (TCs) in the dispersive format from aqueous or organic solutions. Silica-based sorbents especially functionalized with primary amine, secondary amine, or carbonyl groups have showed higher capacity than polymeric sorbents under organic environment. In the proposed dispersive solid-phase microextraction method, after extraction with acetonitrile and salt-promoted partitioning, TCs were adsorbed to a small amount of dispersive silica-based primary and secondary amine sorbents, desorbed with a small volume of desorption solution, and determined by high-performance liquid chromatography with diode-array detection. Under the optimal conditions, recoveries were determined for surface water and milk samples spiked at 10 ng/mL and 50-150 ng/g, respectively, and quantification was achieved by matrix-matched calibration. The calibration curves of four TCs in both samples showed linearity with a correlation coefficient value above 0.997. Average recoveries ranged from 97.1 to 104.1% and the precision was from 2.0 to 5.6%. Limits of detection ranged from 0.7 to 3.5 ng/mL and from 7.9 to 35.3 ng/g for four TCs surface in surface water and milk samples, respectively.

Application of dispersive liquid-liquid microextraction and dispersive micro-solid-phase extraction for the determination of quinolones in swine muscle by high-performance liquid chromatography with diode-array detection.

Dispersive liquid-liquid microextraction (DLLME) and dispersive micro-solid-phase extraction (DMSPE) are two simple and low-cost sample preparation methods for liquid samples. In this work, these two methods were applied to solid tissue sample for the determination of seven quinolones by high-performance liquid chromatography with diode-array detection (HPLC-DAD). After the homogenization of the swine muscle with acetonitrile and salt-promoted partitioning, small amounts of the extract were used for the DLLME and DMSPE methods. In the DLLME approach, the target analytes in the extraction solvent were rapidly extracted into a small volume of dichloromethane for drying and the residue was reconstituted for HPLC-DAD analysis. In the DMSPE approach, the target analytes in the extraction solvent were trapped by dispersive silica-based PSA (primary and secondary amine) sorbents and desorbed into a small amount of desorption solution for HPLC-DAD analysis. Under the optimal conditions, relative recoveries were determined for swine muscle spiked 50-200 microg kg(-1) and quantification was achieved by matrix-matched calibration. The calibration curves of seven quinolones showed linearity with a correlation coefficient value above 0.998 for both approaches. Relative recoveries ranged from 93.0 to 104.7% and from 95.5 to 111.0% for DLLME and DMSPE, respectively. Limits of detection (LODs) ranged from 5.6 to 23.8 microg kg(-1) and from 7.5 to 26.3 microg kg(-1) for DLLME and DMSPE, respectively.

The Internet and healthcare in Taiwan: value-added applications on the medical network in the National Health Insurance smart card system.

The introduction of smart card technology has ushered in a new era of electronic medical information systems. Taiwan's Bureau of National Health Insurance (BNHI) implemented the National Health Insurance (NHI) smart card project in 2004. The purpose of the project was to replace all paper cards with one smart card. The NHI medical network now provides three kinds of services. In this paper, we illustrate the status of the NHI smart card system in Taiwan and propose three kinds of value-added applications for the medical network, which are electronic exchange of medical information, retrieval of personal medical records and medical e-learning for future development of health information systems.

Operating costs and capacity in the airline industry.

This study illustrates how to calculate accurate costs, including the operating costs for individual airplanes and flights, as well as the costs per available seat kilometers, and per available ton kilometers using activity based costing. It also identifies the main activity items and drivers of each airplane and flight. Additionally, it uses a case study to illustrate the calculation of production variance, marketing variance and expected idle passenger capacity in the airline industry. This is useful information when the purchase or lease an airplane under the conditions of idle capacity.