Since ancient times in China, decocting times have been adjusted to improving objective medicinal effects. In medical texts, decocting times are dictated by the amount of water that is reduced. And in this report, we surveyed rhubarb (Chinese, Da-huang ; Japanese, Daio) formulation decocting times described in the earliest Shang-han-lun and Jin-gui-yao-lue texts, from the amount of water changed. We found that rhubarb decocting times could be divided into four 10-, 20-, 30- and 50-minute groups when rhubarb is decocted with other crude drugs, while when rhubarb is put in water after other crude drugs, decocting times could be divided into four 1-, 5-, 10- and 20-minute groups. Next, when we prepared rhubarb decoctions using unprocessed rhubarb and processed rhubarb, and compared change in the principal compounds eluted into those decoctions, we found that 80% or more of the principal compounds were eluted into a decoction when either unprocessed or processed rhubarb were decocted for 30 minutes. It was therefore clear that, in ancient times, rhubarb formulations were decocted for 10 to 30 minutes so that not all of the principle compounds would elute, or given 50 minutes to allow all the principle compounds to elute. Meanwhile, it was also clear that rhubarb was put in water1to 20 minutes before decocting finished, to adjust the amount of principle compound eluted.

Objectives: Diagnosis and treatment of osteoporosis are instrumental in obtaining good outcomes of hip surgery.Measuring bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA) is the gold standard for diagnosing osteoporosis. However, due to limited access to DXA, there is a need for a screening tool to identify patients at a higher risk of osteoporosis. We analyzed the potential utility of the Osteoporosis Self-assessment Tool for Asians (OSTA) as a screening tool for osteoporosis. Methods: A total of 1378 female patients who underwent hip surgery at 8 institutions were analyzed. For each patient, the BMD of the proximal femoral region was measured by DXA (DXA-BMD), and the correlation with OSTA score (as a continuous variable) was assessed. Receiver operating characteristic (ROC) curve analysis was performed to assess the ability of OSTA score to predict osteoporosis. Lastly, the OSTA score was truncated to yield an integer (OSTA index) to clarify the percentage of patients with osteoporosis for each index. Results: DXA-BMD showed a strong correlation with OSTA (r = 0.683; P < 0.001). On ROC curve analysis, the optimal OSTA score cut-off value of − 5.4 was associated with 73.8% sensitivity and 80.9% specificity for diagnosis of osteoporosis (area under the curve: 0.842). A decrease in the OSTA index by 1 unit was associated with a 7.3% increase in the probability of osteoporosis. Conclusions OSTA is a potentially useful tool for screening osteoporosis in patients undergoing hip surgery. Our findings may help identify high-risk patients who require further investigation using DXA.