Temperate rainforests near the South Pole during peak Cretaceous warmth.

The mid-Cretaceous period was one of the warmest intervals of the past 140 million years1-5, driven by atmospheric carbon dioxide levels of around 1,000 parts per million by volume6. In the near absence of proximal geological records from south of the Antarctic Circle, it is disputed whether polar ice could exist under such environmental conditions. Here we use a sedimentary sequence recovered from the West Antarctic shelf-the southernmost Cretaceous record reported so far-and show that a temperate lowland rainforest environment existed at a palaeolatitude of about 82° S during the Turonian-Santonian age (92 to 83 million years ago). This record contains an intact 3-metre-long network of in situ fossil roots embedded in a mudstone matrix containing diverse pollen and spores. A climate model simulation shows that the reconstructed temperate climate at this high latitude requires a combination of both atmospheric carbon dioxide concentrations of 1,120-1,680 parts per million by volume and a vegetated land surface without major Antarctic glaciation, highlighting the important cooling effect exerted by ice albedo under high levels of atmospheric carbon dioxide.

Safety of autologous drainage blood reinfusion following total knee arthroplasty prepared with hydrogen peroxide.

In a clinical in vivo study, wound blood collected from an autologous reinfusion drain of patients undergoing elective total knee arthroplasty was examined to investigate if hydrogen peroxide bone surface preparation had an adverse effect on blood destined to be reinfused. The post-operative drain blood of thirty-eight patients was collected after pre-implantation bone preparation being performed either with or without the use of hydrogen peroxide. Filtered drain blood samples were analyzed and mean results for treatment / control groups respectfully were: haemoglobin (g/L) 98.6/100.9, p=0.7221; haemoglobin change from baseline (g/L) -39.1/-32.9, p=0.2117; MCV (fL) 94.6/93.1, p=0.2897; MCV change from baseline (fL) 2.0/2.5, p=0.6417; potassium (mmol/L) 4.5/4.6, p=0.8212; free haemoglobin (g/L) 1.2/1.3, p=0.4387; methaemoglobin (%) 0.2/0.2, p=0.8112; presence of echinocytes (%) 14/18, p=1.0000. These were all within safe limits for reinfusion. Under the study conditions, application of hydrogen peroxide followed by thorough lavage of the knee joint did not appear to result in any untoward degradation of the extravasated blood that might preclude its use for postoperative autologous drainage blood reinfusion.