The author's retinoscopy with a double-door type of illumination is presented in this paper. It is an objective method for the measurement of refractive errors by using an elect ic retinoscope. Spherical lens are used to neutralize the illumination from the pupil of the Patient u til the size, intensity and rapidity of movement of the double-door illumination from the pupil becomes almost identical. When a lineal back slit srace has been revealed in the middle of the double-door illumination, with a point of re(?)lex light on the center corneal surface, the neutral point is determined. The main points of using this method are also discussed in this paper.

BACKGROUND:The artificial joint has gone through nearly a century of history from the beginning of design to the clinical application. The forerunner of artificial joints is artificial hip joint. With the skiled technological application in clinic, the design, application and improvement of wrist, shoulder, knee and other artificial joints have been promoted. OBJECTIVE: To summarize the application progress and performance characteristics of artificial joint materials in exercise-induced articular cartilage injury. METHODS: PubMed (http://www.ncbi.nlm.nih.gov/PubMed), Wanfang database (http://wanfangdata.com.cn/) and China National Knowledge Infrastructure (http://www.cnki.net/) during 1980 to 2015 were retrieved by the first author. “Sports; Cartilage Injury; Artificial Joint” were taken as the key words in English and Chinese, respectively. Retrieved data were analyzed and summarized. The artificial joint materials commonly used at home and abroad were introduced and analyzed one by one. The clinical advantages and disadvantages of various materials were analyzed from the view of materials science. The surface treatment methods commonly used for artificial joints were described. The direction of the artificial joint research was pointed out from a development perspective. RESULTS AND CONCLUSION:The surface modification of titanium aloys can obtain surface ceramic layer with good performance, and can effectively improve the anti-wear properties of titanium aloys. The filing and modification of ultra-high molecular weight polyethylene can obtain joint composites with good anti-wear properties that can effectively reduce the production of ultra-high molecular weight polyethylene wear particles and the biological response induced by ultra-high molecular weight polyethylene wear particles. Further research and improvement of ceramic artificial joints wil be the future direction of development of artificial joints.

Objective To prove the prophylactic function of absorbable gelatin sponge and bioprotein glue for prevention of epidural and nerve root scar adhesions after laminectomy. Methods We excised the L6 vertebral plates of 36 adult New Zealand male rabbits,to make vertebral plate excision model and to find nerve root. Then divided them into 3 groups based on different materials:gelatin sponge and bioproten glue (group A),gelatin sponge (group B) and saline solution (group C). The morphological changes of the scars were observed grossly and histologically at 2 and 8 weeks after operation. We also measured the orbit of the nerve root. Results Gelatin sponge combining with bioprotein glue can reduce adhesion obviously(P