Prenatal diagnosis and treatment of fetal long QT syndrome: a case report

We report a case of a fetus presenting with bradycardia, intermittent atrioventricular (AV) block, ventricular tachycardia (VT) and the signs of fetal congestive heart failure (ascites and scrotal hydrocele) during mid-gestation. Prenatal treatment with β-adrenergic blocker (propranolol) and digitalis glycosides was prescribed because of suspicion of long QT syndrome occurring with fetal congestive heart failure. The male baby was born at 39 weeks of gestation and showed a prolonged QT interval (QTc = 492 ms) and frequent variable AV block or alternating left and right bundle branch block, depending on the atrial rate. Prenatal administration of lidocaine failed to correct the fetal VT. Conversely, propranolol decreased the attack frequency of fetal VT. Postnatal administration of the K⁺ channel opener (nicorandil) successfully shortened the QT interval and improved the outcome. Copyright © 2002 John Wiley & Sons, Ltd.     

Molecular study of thermal immobilization of chromium(VI) with clay

Clay that contains kaolinite has been used extensively as a raw material for manufacturing of bricks and china at 900-1100 degrees C. This study used clay to stabilize the contaminant chromium(VI) [Cr(VI)] through a heating process at 500-1100 degrees C. X-ray absorption spectroscopic results indicated that the 500-900 degrees C heating process transformed hazardous Cr(VI) to nontoxic Cr(III); Cr2O3 was the species detected as most abundant. The 1100 degrees C heating process caused the formation of Cr2SiO5, which was not detected in the samples heated at 500-900 degrees C. Fourier transformed extended X-ray absorption fine structure spectra were fitted by use of WinXAS software. Phase shifts and backscatter(ing) amplitudes for specific atom pairs, based on the crystallographic data for CrO3 and Cr2O3, were theoretically calculated with the FEFF software. The processed XAS data show that the first shell coordination numbers were similar to each other as the temperature was increased from 500 to 900 degrees C and 1100 degrees C, implying that their Cr(III) crystallite size was relatively similar. The interatomic distance between the target center element and the first shell for the 500-1100 degrees C samples was 1.98 A. The Debye-Waller factor for the 1100 degrees C sample was increased compared with the 500 and 900 degrees C samples and probably indicates the formation of Cr2SiO5.     

Enzymatic Degradation and Aminolysis of Microbial Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) Single Crystals

Solution-grown single crystals of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] were hydrolyzed by polyhydroxybutyrate (PHB) depolymerase from Ralstonia pickettii T1. Enzymatic degradation proceeded from the edges of lamellar crystals, yielding serrated contour and small crystal fragments. Gel permeation chromatography analysis revealed that the molecular weights of the crystals decreased during enzymatic degradation, suggesting that the enzymatic hydrolysis of chain-folding regions at the crystal surfaces occurred in addition to the enzymatic degradation at crystal laterals or edges. After P(3HB-co-4HB) single crystals were aminolysed in 20% aqueous methylamine solution to remove the folded-chain regions and enzymatic degradation by lipase from Rhizopus oryzae to remove 4HB components at crystal surfaces of single crystal aminolyzed, it was found that a small amount (up to ca. 2 mol%) of 4HB component can be incorporated into the P(3HB) mother crystal lattice irrespective of the 4HB content.     

Assessing the potential exposure risk and control for airborne titanium dioxide and carbon black nanoparticles in the workplace

Purpose  

This study assessed the potential exposure risks for workers in the workplace exposed to airborne titanium dioxide nanoparticles (TiO₂-NPs) and carbon black nanoparticles (CB-NPs). The risk management control strategies were also developed for the NP engineering workplace.     

Prenatal detection of limb defects after chorionic villus sampling

Prenatal sonographic diagnoses of two cases of severe limb defects after first-trimester chorionic villus sampling (CVS) are presented. Pathological examination after elective termination correlated well with the prenatal sonographic findings. Although the relationship between CVS and limb defects remains controversial, careful ultrasound examination for possible limb defects in cases receiving CVS is recommended.     

A long-term survey on anthropogenic impacts to the water quality of coral reefs, southern Taiwan

Before 2001, the ecological protection area in the Kenting National Park (KTNP), southern Taiwan, was poorly described. In this study, a set of four-year data (2001-2004) of seawater qualities at 19 sampling sites around the Nanwan Bay in the KTNP was used to explore anthropogenic impacts to ecological environment, especially coral reefs. The parameters of water quality were analyzed immediately after collection. The results showed that higher values of nutrients and suspended solids were attributed to the higher run-off around Nanwan Bay. The fluxes of nutrients and suspended solids were consistently correlated to rainfall. Hence, equations were developed to calculate nutrient fluxes and suspended solids by using only rainfall data. Our results show that suspended solids and ammonia were the dominant factors leading to the drop in coral coverage. In summary, the water quality in the intertidal zone of Nanwan Bay has been degraded and required greater attention.     

Thermal detoxification of hazardous metal sludge by applied electromagnetic energy

Industrial wastewater sludge was treated by microwave processes to enhance the stabilization of laden copper. The effects of additives, processing time, microwave adsorbents, moisture content, reaction atmosphere, and cooling gas were investigated. The stabilization results were significantly enhanced by metal powder additives, prolonged microwave processing time, proper moisture content, the addition of carbonaceous materials, and a reaction environment with inert gas. It was also found that the moisture content would increase the homogeneity of applied microwave energy, and thus achieve a better overall efficiency between stabilizing agents and copper. The added metal powders may reduce Cu(II) to Cu(0) in the sludge or TCLP. The resulting thermal energy of microwave radiation, and microarcing process and the oxidation heat of Al powder may also assist the transformation of Cu(II) into CuO and CuAl2O4 phases. Part of the sludge was vitrified within inert gas environment when the processing time was longer than 18 min and active carbon dosage was more than 3g. Reduction reactions also occurred in the hybrid microwave processes, leading to the reduction of sulfates and metal ions, and the formation of Cu2S and FeS. Moreover, the microwave radiation can also enhance the feasibility of co-treating of inorganic and organic solid waste.     

PAH emission from the incineration of three plastic wastes

A batch-type, controlled-air incinerator was used for the treatment of polyvinyl chloride (PVC), high-density polyethylene (HDPE), and polypropylene (PP) plastic wastes. The concentration and composition of 21 individual polycyclic aromatic hydrocarbons (PAHs) in the raw wastes, flue gas (gas and particle phases), and ash were determined. Stack flue-gas samples were collected by a PAH stack-sampling system. Twenty-one individual PAHs were analyzed primarily by a gas chromatograph/mass spectrometer (GC/MS). The CO concentration correlated well with the total PAH (R2 > .89), and thus can be used as a surrogate indicator for PAH emission. Excess amounts of air supply in the incineration of plastic wastes could decrease not only the concentration of the PAHs in the bottom ash but also the emission factor (EF) of the total PAH in the stack flue gas. Of the three plastic wastes, HDPE was found to have the highest mean EF of the total PAHs (462.3 mg/kg waste) from the stack flue gas. Incinerating PVC would result in a higher EF of PAHs (195.4 mg/kg waste) in the bottom ash. When PVC plastic wastes were incinerated, higher-ringed PAHs constituted a larger percentage in the bottom ash as compared to those from PP and HDPE plastics. By judging the output and input (O/I) ratio of the PAHs from the incineration trials of plastic wastes, the PAHs involved in incineration of three plastic wastes were almost entirely destroyed; and a low residual amount between 0.00018 and 0.00032 remained in the emission.