Background: Laparoscopic resection is increasingly used in colorectal cancer (CRC). It has been suggested to carry short-term benefits in safety, recovery, and preservation on immune function for patients with CRC. However, the impact of laparoscopic resection on natural killer (NK) cells is largely unclear. Methods: A total of 200 patients with CRC across Dukes A/B/C stages were randomly assigned to laparoscopic or open resection. The blood samples were collected before and after the surgery. The total number of NK cells was quantified by flow cytometer. Lytic units 35 toward K562 was used to quantify NK cells activity. The outcomes between the groups across pathological stages were also analyzed. Results: The number and activity of NK cells decreased after the surgery in both groups. The laparoscopic group showed a faster recovery rate of NK cells function than the control group as assessed by cell count and lytic activity. Natural killer cells were impaired in a higher degree in patients at Dukes B/C stages. The recovery of NK cells to baseline level at day 7 postsurgery was observed in the laparoscopic group across all 3 stages. Conclusion: Generally, laparoscopically assisted surgery resulted in a better preservation on NK cells function. A better outcome was observed in patients with CRC at Dukes B/C stages.

The technique of backhand topspin against backspin is important for table tennis players to gain more advantages in the confrontation. In this paper, a biomechanical analysis of backhand topspin against backspin was conducted with varsity and non-varsity male table tennis players from Zhejiang Changzheng Vocational and Technical College. The QUAL-ISYS infrared acquisition system collected the changes in the athletes' limb movements, and the force platform collected the changes in the athletes' limb moments in the ball striking process. The results showed that professionally trained athletes were able to achieve greater joint angles and provide greater torques to the shoulder, elbow and wrist joints at the moment of batting. The main purpose of this paper is to provide data reference for the improvement of backhand stroke technique by studying the pattern of limb movements of players when they perform backhand stroke. In summary, in order to improve the backhand technique of hitting backspin, athletes need to focus on training the shoulder, elbow and wrist joints to achieve greater variations of angles and greater torques. The novelty of this paper is collecting the body movements of backhand strokes in a more concise and fast way with the QUALISYS infrared acquisition system. KEYWORDS backhand topspin against backspin, biomechanics, QUALISYS, table tennisHow to cite this article: Guo, H.: Biomechanical comparison of backhand topspin against backspin between different level table tennis athletes using QUALSYS infrared acquisition.