Objective To evaluate the feasibilities and advantages of different concentrations of sodium alginate (SA) solutions as a submucosal injection solution for endoscopic submucosal dissection (ESD). Methods In vitro study, different concentrations of sodium alginate solutions and normal saline were injected into submucosal of resected porcine esophagus and stomach respectively, then observe and measure the heights of each injection induced mucosal elevations, and their changes over time. In vivo study, the mimic ESD were conducted in healthy pigs to evaluate the mucosal elevation effect and other assistant effects of sodium alginate as a submucosal injection solution. Results The elevation heights of the experiment groups injected with SA solutions were much higher than the control group injected with normal saline. Specially, the elevation created by 1 % SA in porcine esophagus was significantly higher than that of normal saline (P < 0.01) and the elevation created by 3 % SA was significantly higher than that of normal saline in porcine stomach (P < 0.001). In the mimic ESD experiment, mucosal elevation with clear margin occurred immediately after injection with SA solution. And the durable submucosal fluid cushion created by SA protected deeper tissues while facilitating ESD procedure. Conclusion The elevation heights created by SA solutions were greater and more durable than that created by normal saline, which were crucial for ESD. The viscosity property enabled SA to form a stable protective cushion and prevent bleeding by squeezing tissue around the wound, which may decrease perforation and bleeding rate during ESD procedure. Therefore, sodium alginate can be an ideal clinical submucosal injection solution.

"Tendency of disease" is an important concept in the theory of traditional Chinese medicine （TCM）. It was born out of and rooted in the thinking of "conducting by tendency" of ancient Chinese philosophy， meaning that the development and change of humans and nature have their own inevitable laws and dynamic tendencies. Based on the concept of holism and constant motion， the basic definition of "tendency"， the origin of the idea， the influence factors and related concepts were analysed， to grasp the overall connection in the dynamic changes in space and time， and to find a scientific and comprehensive objective law of development. The "tendency" was regarded as dynamic forces in the complex system， when yin and yang harmonized， called normal tendency； when fail to keep normal， called disease tendency； the season have sequential tendency， the earth has geographical tendency， people have body tendency， medications have medical tendency， and pulse has pulse tendency. Then the "eight methods of treating tendency" were summed up as observing tendency， evaluating tendency， waiting for tendency， accumulating tendency， favoring tendency， counteracting tendency， preventing tendency， and borrowing tendency， and condenses the methodo-logical thinking of "treatment according to disease tendency"， with a view to re-understanding the internal logic of TCM diagnosis and treatment， and providing metaphysical contemplation and exploration for the construction of a new paradigm of TCM syndrome differentiation and treatment.