Iron-mediated injury plays an important role in a number of heart disorders. Studies on heart iron are therefore crucial for understanding the causes of excessive heart iron. Heart cells have the ability to accumulate transferrin-bound-iron via the transferrin receptor and non-transferrin-bound-iron probably via the L-type Ca2+ channel and the divalent metal transporter1. However, little is known about the mechanisms of iron export in the heart cells. Here, we investigated expression of iron exporters including ferroportin 1 (Fpn1), ceruloplasmin (CP) and hephaestin (Heph) and provided evidence for their existence in the heart. We demonstrated that iron has a significant effect on expression of Fpn1 and CP, but not Heph. Treatment of a high-iron diet induced a significant increase in Fpn1, a decrease in CP but no change in Heph mRNA and protein. The control of Fpn1 and CP protein expression by iron was parallel to that of their mRNA expression, suggesting a transcriptional regulation of Fpn1 and CP by iron. The existence of these proteins in the heart implies that they might have a role in heart iron homeostasis.

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1The loss of proteoglycan (PG) is regarded as one of the early signs of osteoarthritis (OA), 2 thus observing the progress of PG loss would be useful for the early detection of OA. In 3 this study, high-frequency ultrasound was used to monitor and analyze the trypsin-4 induced progressive degeneration in articular cartilage. Full-thickness cartilage-bone 5 specimens (n = 10) prepared from normal bovine patellae were digested using 0.25% 6 trypsin solution for different periods of time to evaluate the dynamic of the digestion 7 process. The trypsin penetration front was observed in M-mode image, which was 8 acquired using a nominal 50 MHz focused transducer. The transient speed of the 9 digestion process was estimated from the image. The digestion fraction, which represents 10 the ratio of the digestion depth to the total cartilage thickness, was estimated from 11 ultrasound data and histology sections. With ultrasound, the digestion fraction observed 12 in the 10 specimens ranged from 64 to 99%, and was correlated to that measured by 13 histology (R 2  0.63, p<0.05). It was found that the digestion speed decreased nonlinearly 14 with depth from 0.61 ± 0.16 m/s (mean ± SD) in the superficial zone to 0.04 ± 0.02 15 m/s in a region located at 70% of the cartilage thickness in depth. The relationship 16 between the digestion depth and the exposure duration in trypsin could be described 17 using a 3 rd order polynomial function. The full-thickness of digested and undigested 18 tissues was also measured using caliper, estimated from ultrasound data and histology 19 sections, and compared. These findings indicate that ultrasound could provide useful 20 information about the trypsin-induced progressive PG depletion in articular cartilage. 21Therefore, ultrasound represents a useful tool to evaluate the dynamic of models of OA in 22 vitro in cartilage specimens in a research environment, and this would ultimately help the 23 in-vitro examination of articular cartilage for research related to model of OA from the 24 early stages of tissue degradation. 25

A bench-scale study was undertaken to examine the effects of easily biodegradable organic carbon substrate on denitrification reaction and overall nitrogen removal from domestic wastewater under a modified sequencing batch reactor (SBR) system. The operation strategy of the SBR consisted of 0.75 h FILL, 8 h REACT separated into 4 h aerobic, 3 h anoxic and 1 h aerobic stages, 1.5 h SETTLE, 1 h DRAW and 0.75 h IDLE. Methanol, sodium acetate and sodium propionate, at the concentrations equivalent to theoretical COD values of 50, 100 and 150 mg O2 1−1 were used as the external carbon sources and added to the reactors prior to the anoxic stage. The study reveals that 4 h aerobic stage was sufficient to nitrify more than 98% NH4+-N and carbon addition caused slightly more nitrification than the control. Addition of sodium propionate at a low concentration (50 mg O2 1−1) significantly enhanced the denitrification process, the nitrate content in this reactor dropped to 3 mg 1−1 (89% reduction) at the end of the anoxic stage. Among the three substrate added at low dose, sodium propionate was the most effective carbon source, followed by acetate and the least effective one was methanol. When the carbon substrate were added at the doses of 100 and 150 mg O2 1−1, the denitrification rates of the acetate reactors recorded at the first hour of the anoxic stage were similar to those of the propionate's and significantly higher than the methanol reactors. When high dose (150 mg O2 1−1) of acetate or propionate was used, 95% reduction in wastewater NOx-N was found after 1 h anoxic stage while 3 h anoxic stage was required when the carbon dose was at 100 mg O2 1−1, indicating that addition of external carbon substrate at large quantity could shorten the denitrification time. However, the final effluent discharged from reactors treated with high dose of acetate and propionate contained more than 20 mg 1−1 BOD5 which might cause a contamination problem. Therefore, addition of sodium acetate or propionate at the concentration equivalent to theoretical COD values of 100 mg O2 1−1 appeared to be the most economical and reliable option.

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