ON THE THEORY OF WASHING AND EXTRACTION

When precipitates are washed with a definite quantity of water or some other solvent, it's not recommended to use the washings at the same time. The principle also applies to the extraction between two liquid phases. In almost all analytical textbooks this principle is introduced with the next formula : [numerical formula] In some of them such special numbers, for instance, as n=4 and 5 are put in the formula to show C_5 <C_n

ON THE THEORY OF WASHING AND EXTRACTION

When precipitates are washed with a definite quantity of water or some other solvent, it's not recommended to use the washings at the same time. The principle also applies to the extraction between two liquid phases. In almost all analytical textbooks this principle is introduced with the next formula : [numerical formula] In some of them such special numbers, for instance, as n=4 and 5 are put in the formula to show C_5 <C_n

Efficacy of a Novel Narrow Knife with Water Jet Function for Colorectal Endoscopic Submucosal Dissection

Backgrounds. With respect to the knife’s design in colorectal endoscopic submucosal dissection (ESD), diameter, water jet function, and electric power are important because these relate to efficient dissection. In this study, we analyzed a novel, narrow ball tip-typed ESD knife with water jet function (Flush knife BT-S, diameter: 2.2 mm, length: 2000 mm, Fujifilm Co., Tokyo, Japan) compared to a regular diameter knife (Flush knife BT, diameter: 2.6 mm, length: 1800 mm). Methods. In laboratory and clinical research, electric power, knife insertion time, vacuum/suction amount with knife in the endoscopic channel, and water jet function were analyzed. We used a knife 2.0 mm long for BT-S and BT knives. Results. The BT-S showed faster mean knife insertion time (sec) and better vacuum amount (ml/min) compared to the BT (insertion time: 16.7 versus 21.6, p<0.001, vacuum amount: 38.0 versus 14.0, p<0.01). Additionally, the water jet function of the BT-S was not inferior. In 39 colorectal ESD cases in two institutions, there were mean 4.7 times (range: 1–28) of knife insertion. Suction under knife happened 59% (23/39) and suction of fluid could be done in 100%. Conclusions. Our study showed that the narrow knife allows significantly faster knife insertion, better vacuum function, and effective clinical results