Differences in bioaccumulation and transfer ability between tributyltin and triphenyltin from parental female to offspring in viviparous surfperch Ditrema temmincki

To examine the risk of transgenerational transfer of organotin compounds (OTs) in fish, tributyltin (TBT) and triphenyltin (TPT) compounds and their breakdown products were determined in both parental females and offspring of viviparous surfperch Ditrema temmincki collected from Japanese coastal waters. TBT concentrations (Mean ± SD) in the offspring (34 ± 5.7 ng Sn g−1 wet wt) were significantly higher (10–17 times) than in the parental females (2.8 ± 1.0 ng Sn g−1 wet wt). In the offspring, TBT was the predominant butyltin compound (82 ± 1.6% ∑BTs = TBT + DBT + MBT), and represented a greater proportion than in the parental females (51 ± 9.3% as TBT). TPT concentrations were significantly lower than TBT, and the ratio of TPT in parental females, relative to offspring, was different from TBT. TPT concentrations in the offspring (0.8 ± 0.3 ng Sn g−1 wet wt) were almost identical to those in the parental females (1.0 ± 0.5 ng Sn g−1 wet wt). TPT was the predominant phenyltin (∑PTs = TPT + DPT + MPT) in both offspring (73 ± 12% as TPT) and parental females (72 ± 18% as TPT). Results suggest that the transfer rate of TBT from parent to offspring could be much faster than its degradation rate in the offspring, accounting for higher accumulation of TBT in the latter. In contrast, the transfer rate of TPT is slower than its biodegradation, leading to a lower concentration of TPT in the offspring. It is therefore likely that the offspring might be at a higher risk from TBT than the parental females during their early growth stage in ovary in the viviparous surfperch whereas exposure to TPT is comparable in both generations

Conveyance Test by Oscillation and Rotation to a Permanent Magnet Repulsive-Type Conveyor

Various applications of a single-axis controlled repulsive-type magnetic bearing have been proposed earlier. However, most conventional systems are equipped with a set of passive magnetic bearings and an active magnetic bearing. In this paper a new repulsive-type conveyor system with many passive magnetic bearing pairs is proposed. This system enables an easy rotation with negligible friction and soft conveyance by radial stiffness between the rotor and the stator permanent magnets. This paper also reports a conveyance test using ellipse motion of each shaft

Effects of tributyltin on the chlorophyll contents of marine microalga Tetraselmis tetrathele, Nannochloropsis oculata and Dunaliella sp

Three species of marine microalga Tetraselmis tetrathele, Nannochloropsis oculata and Dunaliella sp., the important phyto-plankton in many hatcheries, were used in an acute toxicity test of TBT with emphasis on the chlorophyll a and b contents. After a very short exposure time of three concentrations of TBT, 0.1, 0.5 and 1μgl^, the three species of algae showed different responses. The chlorophyll a and b contents of T. tetrathele in all treatments were higher than those in controls, even be doubled in 1μgl^ of TBT. N. oculata and Dunaliella had a slightly higher chlorophyll a and b contents in the lowest TBT concentration tested (0.1μgl^) than those in control, but as the TBT concentration increased their chlorophyll contents decreased. Three levels of TBT tested are within the range of the no observable effect concentration (NOEC) for T. tetrathele, while the lowest observable effect concentrations (LOEC) for N. oculata and Dunaliella are between 0.1 to 0.5μgl^. Among the three species, N. oculata has a highest sensitivity towards TBT

The effect of non-uniform magnetization of permanent magnets on the performance of a repulsive type magnetic bearing system

A permanent magnet bearing (MB) system utilizing the repulsive forces operating between the stator and rotor permanent magnet for levitation and radial control has been fabricated in our laboratory, The consistency of the permanent magnet magnetization effects the continuous steady-state and dynamic performance of the system. Since both the magnets are repelling each other, there will be demagnetization of the magnetization of the permanent magnet. Due to demagnetization or ageing or manufacturing asymmetry, the field distribution may not be uniform along the periphery of the magnet. In this paper the effect of this magnetization non-uniformity on the performances of the bearing system has been studied

'Correction:' Serum transforming growth factor beta-1 (TGF-beta-1) levels in diabetic patients are not associated with pre-existent coronary artery disease

<p>Abstract</p> <p>Background</p> <p>The association between TGF-β1 levels and long-term major adverse cardiovascular events (MACE) in patients with coronary artery disease (CAD) is controversial. No study specifically addressed patients with CAD and diabetes mellitus (DM). The association between TGF-β1 levels and long-term major adverse cardiovascular events (MACE) in patients with coronary artery disease (CAD) is controversial. No study specifically addressed patients with CAD and diabetes mellitus (DM).</p> <p>Methods</p> <p>Patients (n = 135, 30–80 years) referred for coronary angiography were submitted to clinical and laboratory evaluation, and the coronary angiograms were evaluated by two operators blinded to clinical characteristics. CAD was defined as the presence of a 70% stenosis in one major coronary artery, and DM was characterized as a fasting glycemia > 126 mg/dl or known diabetics (personal history of diabetes or previous use of anti-hyperglycemic drugs or insulin). Based on these criteria, study patients were classified into four groups: no DM and no CAD (controls, C n = 61), DM without CAD (D n = 23), CAD without DM (C-CAD n = 28), and CAD with DM (D-CAD n = 23). Baseline differences between the 4 groups were evaluated by the χ²test for trend (categorical variables) and by ANOVA (continuous variables, post-hoc Tukey). Patients were then followed-up during two years for the occurrence of MACE (cardiac death, stroke, myocardial infarction or myocardial revascularization). The association of candidate variables with the occurrence of 2-year MACE was assessed by univariate analysis.</p> <p>Results</p> <p>The mean age was 58.2 ± 0.9 years, and 51% were men. Patients with CAD had a higher mean age (p = 0.011) and a higher percentage were male (p = 0.040). There were no significant baseline differences between the 4 groups regarding hypertension, smoking status, blood pressure levels, lipid levels or inflammatory markers. TGF-β1 was similar between patients with or without CAD or DM (35.1 ×/÷ 1.3, 33.6 ×/÷ 1.6, 33.9 ×/÷ 1.4 and 31.8 ×/÷ 1.4 ng/ml in C, D, C-CAD and D-CAD, respectively, p = 0.547). In the 2-year follow-ip, independent predictors of 2-year MACE were age (p = 0.007), C-reactive protein (p = 0.048) and systolic blood pressure (p = 0.008), but not TGF-β1.</p> <p>Conclusion</p> <p>Serum TGF-β1 was not associated with CAD or MACE occurrence in patients with or without DM.</p