Continuous carbon capture in an electrochemical solid-electrolyte reactor

Electrochemical carbon-capture technologies, with renewable electricity as the energy input, are promising for carbon management but still suffer from low capture rates, oxygen sensitivity or system complexity^1-6. Here we demonstrate a continuous electrochemical carbon-capture design by coupling oxygen/water (O₂/H₂O) redox couple with a modular solid-electrolyte reactor⁷. By performing oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) redox electrolysis, our device can efficiently absorb dilute carbon dioxide (CO₂) molecules at the high-alkaline cathode-membrane interface to form carbonate ions, followed by a neutralization process through the proton flux from the anode to continuously output a high-purity (>99%) CO₂ stream from the middle solid-electrolyte layer. No chemical inputs were needed nor side products generated during the whole carbon absorption/release process. High carbon-capture rates (440 mA cm^-2, 0.137 mmol_CO2 min^-1 cm^-2 or 86.7 kg_CO2 day^-1 m^-2), high Faradaic efficiencies (>90% based on carbonate), high carbon-removal efficiency (>98%) in simulated flue gas and low energy consumption (starting from about 150 kJ per mol_CO2) were demonstrated in our carbon-capture solid-electrolyte reactor, suggesting promising practical applications.

Influence of chronic exposure to cold environment on thyroid gland function in rabbits

Chronic exposure to cold can affect the thyroid gland. However, the effect on thyroid gland perfusion images and the ratio between thyroid hormones secretion were not addressed in any previous study. The present study investigates the effects of chronic cold exposure on thyroid gland function using radionuclide tracer and thyroid hormones secretion concentration. New Zealand white rabbits weighing approximately 1.8-2 kg were kept in a cold room (4°C) for 7 weeks. Thyroid scintigraphy was performed for cold exposed rabbits and a control rabbit group. Each rabbit was injected with 115 MBq (3.1 mCi) technetium-99m pertechnetate (99mTc pertechnetate). Studies were performed using Gamma camera equipped with a low energy, high resolution, pinhole collimator interfaced with a computer. Static images were acquired 20 min after administration of the radiotracer. Rabbits chronically exposed to cold had less body weights than control. Thyroid gland uptake is higher in rabbits chronically exposed to cold than controls using radionuclide perfusion study. The increase was proportional to the time period, so the increase after 7 weeks was greater than 5 weeks. There is also an increase in free triiodothyronine (FT3) and a decrease in free thyroxine (FT4) values. Our results indicate that thyroid gland uptake is higher in rabbits chronically exposed to cold than control and the increase was proportional to the duration. The decrease in rabbit body weights may be related to the increase in metabolism due to the increase of thyroid hormones. Chronic cold exposure also increased the conversion of T4 to T3, which is more potent in thermogenic effect.

Assessment of skeletal muscle damage in experimental animal using In-111 antimyosin

Skeletal muscle injury induced in the thigh muscles of New Zealand rabbits was investigated using radionuclide imaging technique after intravenous injection of In-111 antimyosin. Images were obtained for 3 weeks beginning from the first day of injury. The injury was visualized as early as 3 h after injection of the tracer. The mean uptake ratio of the injury to the normal muscle was 2.8 +/- 0.62 (p < 0.001) on the third to fifth day, decreasing with healing to 1.40 +/- 0.15 by the end of the study (3 weeks). The mean uptake ratio of the more severely crushed left to less severely crushed right side was 1.36 +/- 0.17 (p < 0.01) on the third day. The results of this study show that the radionuclide imaging technique using In-111 antimyosin is useful for the assessment of skeletal muscle damage and also for monitoring the progress of healing. This technique can be applied clinically to evaluate skeletal muscle damage in problematic fractures.

Technetium 99mTc-DTPA clearance in the evaluation of pulmonary involvement in patients with diabetes mellitus

Systemic thickening of capillary endothelial basement membrane underlies the chronic complications of human diabetic microangiopathy. Since 99mTc-DTPA aerosol scintigraphy is a sensitive, non-invasive test of membrane permeability, we decided to study the effect of diabetes on the permeability of lung epithelium in diabetic patients using this test. Fifty (NIDDM) patients, aged 40-70 years, with or without complications, and who were non-smokers, were subjected to evaluation using 99mTc-DTPA aerosol. At the same time, pulmonary function tests, including carbon monoxide diffusion capacity, were done. Normal non-smoking subjects with no history of cardio-respiratory disease, who underwent 99mTc-DTPA and pulmonary function tests, served as controls. The risk factors which included age, sex, degree of control and presence of complications were noted. Twenty-nine (58%) of the patients had abnormal 99mTc-DTPA clearance. Thirty-four percent of the patients with complications and 24% of those without complications had abnormal clearance. Complications recorded included retinopathy, neuropathy and nephropathy. Fifty-five percent of patients with abnormal 99mTc-DTPA had suffered from diabetes for longer than 10 years. Sixty-two percent of patients with poor glycaemic control had abnormal 99mTc-DTPA. Diffusion capacity was not significantly affected in patients with complicated diabetes. Our preliminary results suggest that 99mTc-DTPA is a potentially sensitive test in assessing the degree of lung affection in diabetic patients. No significant correlation exists between diffusion capacity and 99mTc-DTPA. The risk factors did not affect the 99mTc-DTPA clearance, probably due to the small sample size.

The impact of brushing teeth on carbon-14 urea breath test results

OBJECTIVE

The 14C urea breath test noninvasively detects the presence of the urease-producing bacteria Helicobacter pylori in the stomach. Several sources of errors have been identified to cause false or indeterminate results on the test. The objective of this study was to identify whether brushing teeth affects the test results.

METHODS

We performed the 14C urea breath test on 168 patients, with breath samples counted at 10 and 20 min after oral administration of 2 microCi (74 kBq) 14C urea. Ninety-four patients brushed their teeth before the test while 74 did not.

RESULTS

Thirty-six of the 74 patients (49%) who did not brush their teeth had positive results at 10 min, which became negative at 20 min. None of the 94 patients who brushed their teeth before testing showed this pattern with agreement of results at 10 and 20 min.

CONCLUSION

We recommend brushing teeth before the 14C urea breath test since it significantly decreased the ambiguous results of the test in our laboratory.