BACKGROUND:Acellular vascular matrix as vascular scaffold has following advantages:acellular vascular matrix possesses complicated three-dimensional structure of natural blood vessels. Growth factor and structural domain on the surface of acellular matrix helps for cell adhesion and infiltration.OBJECTIVE:To prepare acellular vascular matrix material and to evaluate its biocompatibility in vivo and in vitro.METHODS:Trypsin and Triton X-100 were used to gradually dispose pig carotid artery and to prepare acellular vascular matrix. The biocompstibility of the material was evaluated by implantation in muscle, acute toxicity experiment and cytotoxicity test in vitro.RESULTS AND CONCLUSION:The acallular vascular matrix material possessed good chemical stability and did not release harmful factors that produced destruction and dissolution in erythrocytes, without acute hemolytic reaction or toxic effects on cell growth. The acellular vascular matrix material showed lots of inflammatory cell infiltration in eady stage of implantation, and no significant inflammatory cell infiltration in late stage of observation. Fibroblasts were visible in the acellular matrix. In addition, the acellular matrix material did not exhibit toxic effects on surrounding tissues,showing wound stage I healing.Simultaneously,histological sections demonstrated that there were good compatibility of scaffold material and surrounding tissues, without rejection.These indicated that acellular matrix material presented good biocompatibility in animals.

Objective The reliability and validity of the SGGC-Net-based motion capture system(SGGC-Net system)and SIMI system for parsing walking gait were compared using a three-dimensional(3D)motion capture system(Vicon)with marker points as a reference standard.Methods Thirty healthy college students were recruited,and their gait characteristics while walking on a treadmill were analyzed.Kinematic data were collected using the Vicon system,and video data were collected synchronously using four cameras to obtain the right shoulder,elbow,hip,knee,and ankle joint angles.Reliability was assessed using intraclass correlation coefficients(ICCs)with 95％confidence intervals and standard error of measurement(SEM).Validity was assessed using multiple correlation coefficients(MCCs)and root mean square errors(RMSEs).Results The ICCs of the maximum and minimum 3D coordinate angles of the upper and lower limb joints of the SGGC-Net system ranged from 0.798-0.990 with an SEM of 0.04°-0.95°,and the ICCs of the SIMI system ranged from 0.650-0.967,with an SEM of 0.31°-1.24°.The ICCs of the SGGC-Net system were higher than those of the SIMI system for all joint angles except for the minimum hip and maximum knee angles.Compared to the joint angle curves derived from the SIMI system,the MCCs of the curves derived from the SGGC-Net system ranged from 0.945-0.996,with RMSEs of 1.44°-4.65°,and the multiple correlation coefficients of the SIMI system ranged from 0.815-0.986,with RMSEs of 2.56°-9.99°.The MCCs of the SGGC-Net system were greater than those of the SIMI system at all angles except for the ankle joint.The RMSEs of the SGGC-Net system were smaller than those of the SIMI system at all angles except for the ankle joints.Conclusions The SGGC-Net system has better reliability and validity than the SIMI system in most of the variables,and it has better repeatability and accuracy in analyzing walking gait.It can be applied to motion capture environments without marker points,such as technical analysis of athletes'movements and clinical gait analysis of special populations.

Conventional transcatheter aortic valve replacement is normally recommended with transthoracic echocardiography, and contrast agent mediated fluoroscopy under anesthesia to guide a better implantation of the transcatheter valve. However, iodine-containing contrast agent possibly damages the patient’s kidney, and even induces the acute kidney injury. We reported a 75-year-old patient diagnosed with severe aortic valve stenosis, moderate regurgitation, and chronic renal failure. We performed the aortic valve replacement under the guidance of fluoroscopy and transesophageal ultrasound without contrast agent. Seven days after surgery, the patient recovered well and discharged with alleviated aortic stenosis and fixed transcatheter aortic valve.