Biometric traits of onion (Allium cepa L.) exposed to 137Cs and 243Am under hydroponic cultivation.

To elucidate the features of bioaccumulation and phytotoxic effects of long-lived artificial radionuclides, a hydroponic experiment was carried out with the cultivation of onion (Allium cepa L.) in low-mineralized solutions spiked with 137Cs (250 kBq L-1) or 243Am (9 kBq L-1). After the 27-day growth period, ≈70% of 137Cs and ≈14% of 243Am were transferred from the solutions to onion biomass with transfer factor values ≈ 400 and ≈ 80, respectively. Since the bioaccumulation of both radionuclides mainly took place in the roots of onion (77% 137Cs and 93% 243Am of the total amount in biomass), edible organs - bulbs and leaves - were protected to some extent from radioactive contamination. At the same time, the incorporation of the radionuclides into the root tissues caused certain changes in their biometric (geometric and mass) traits, which were more pronounced under the 243Am-treatment of onion. Exposure to 243Am significantly reduced the number, length, and total surface area of onion roots by 1.3-2.6 times. Under the influence of 137Cs, the dry-matter content in roots decreased by 1.3 times with a corresponding increase in the degree of hydration of the root tissues. On the whole, the data obtained revealed the specific features of 137Cs and 243Am behaviour in "hydroponic solution - plant" system and suggested that biometric traits of onion roots could be appropriate indicators of phyto(radio)toxicity.

The Bex-Nikaidoh operation for dextro-transposition of the great arteries with a ventricular septal defect and pulmonary stenosis using an 'oversized' conduit.

We report a case of a 4-month-old infant with dextro (d)-transposition of the great arteries, ventricular septal defect (VSD) and left ventricular outflow tract obstruction previously palliated with a systemic-to-pulmonary shunt. He underwent repair by aortic root translocation with an arterial switch procedure and coronary artery reimplantation (modified Bex-Nikaidoh operation). This case demonstrates that aortic translocation results in a more normal anatomic repair compared with the Rastelli operation. As shown, it is always possible to place an oversized conduit (homograft) and there is no risk of sternal compression of the conduit. This is especially important for children under 1 year, when there are contraindications for the Rastelli operation. Placement of oversized pulmonary ventricle-pulmonary artery conduits is performed to decrease conduit failure in the future. The postoperative course was uneventful. At 6 months, he was asymptomatic with tomographic images and echocardiography showing no residual lesions.