Articular cartilage repair is limited. Current treatments for cartilage defect are less satisfactory, and rarely restore full function or return the tissue to its native normal state. The rise of tissue engineering holds great promise for the generation of functional cartilage tissue substitutes. The history of cartilage tissue engineering and highlights the applications and advantages of various kinds of scaffolds in cartilage tissue engineering, such as native scaffolds, synthesis scaffolds, composite scaffolds and nanometer scaffolds had been introduced. But native scaffolds have weak strength and immunogenicity insufficiency, synthesis scaffolds degrade quickly, whose degrading products have cytotoxicity,which need further improvement. The application of superficial decoration overcomes the disadvantage of some scaffolds to an extend. Composite scaffolds possess the advantages of several scaffolds, it points out the direction of future scaffolds research. The development of Nanometer technique endows newly-synthesis scaffolds with nano-grade, thus it has some advantages and give a new way for the development of tissue engineering. At the end, the problems of these scaffolds, their trend of development and perspective studies were discussed.

2% hydroxypropyl methyl cellulose (HPMC, medical grade, Taian Ruitai Cellulose Co., Ltd.) was added into calcium phosphate cement (Orthopedics Institute of General Hospital of Chinese PLA) and the mixture was put into distilled water to observe whether the surface was corrupt. Some calcium phosphate cement was immersed in water at different time and the residual cement was weighed 24 hours later. The results showed that there was no surface corruption in calcium phosphate cement with 2% HPMC after shake; the residual weight measured 24 hours later showed that 2% HPMC could shorten calcium phosphate cement cohesion time from 4 minutes to 1 minutes. The experiment indicates that 2% HPMC can significantly increase the waterproof performance of calcium phosphate cement, increase the work time and is adaptable in clinical application.

Objectives: To evaluate the feasibility, safety and validity of the early enteral nutrition in severe acute pancreatitis(SAP). Methods: 15 patients of SAP during April 2002 and June 2003 had received early enteral nutrition through naso jejunal tube. The nutrition and immune index and the rates of complications were analyzed. Results: 2～3 days after nutrition tube placed to stomach, the tube heads in 11 cases reached the jejunum automatically, while 3 cases needed the help of X ray and 1 case needed the help of gastroscopy. All of 15 cases tolerated the enteral nutrition well, and there was no relapse of SAP. The nutrition and immune measurement were improved after 2 weeks' enteral nutrition, without infection of pancreatic necrosis. Conclusions: It is safe, efficient and feasible of the early enteral nutrition in severe acute pancreatitis(SAP) through naso jejunal tube. Early enteral nutrition can improve the nutrition, immune function and prognosis.

Objective: To explore the cause and the strategy for air quantity signaling in old patients using mechanic air. Method: Summary and analysis of the causes for air quantity signaling in 187 cases of old patients using respiratory machine. Results: One hundred fifty-one cases showed low-limited air quantity signaling per minute whereas 36 cases presented high-limited air quantity signaling per minute. Conclusion: Judging and removing the obstacle in respiratory machine on time and accurately are the key point raising both the survival rate of severe patients and the successful rate of mechanic air.

Objective To identify the determinants of average length of stay of 16 upper first-class general hospitals from 2000 to 2007.Methods Relative data of 16 upper first-class general hospitals from 2000 to 2007 were collected, and descriptive analysis and multiple linear regression analysis were employed to explore the determinants of average length of stay. Results Operation ratio and days before operation of inpatients, ratio of salary to medical income, ratio of doctors to nurses, successful rescue rate in emergency, number of operation tables and staff had impact on average length of stay. Conclusion Resource allocation should be optimized, health care quality be enhanced, reasonable salary scheme be designed, and rational medical insurance policies be implemented in hospitals to shorten average length of stay.

Objective To comprehensively evaluate the competitiveness of hospitals so as to provide objective referrences for the long-term development. Methods Competitiveness evaluation index system and evaluation model were established. Using related data of 2007, 16 hospitals nationwide were evaluated and factor scores and comprehensive scores were obtained by means of factor analysis. Results Four factors were extracted, which were "technical efficiency factor", "economic income factor", "sustainable development factor" and "resource allocation factor". All hospitals were ranked by each factor score and comprehensive score. Conclusion Each hospital has its advantages and disadvantages, therefore, hospital managers should constitute individual development strategy accordingly.

Objective To explore the dose-effect relationship between water fluoride levels and hepatic damage in children and observe the difference in hepatic function between high-loaded fluoride people and dental fluorosis people in the same water fluoride level region. Methods 210 children were selected and divided into seven groups according to drinking water fluoride concentrations and whether they suffered from dental fluorosis. Urine and serum fluoride content total protein TP and albumin ALB content and activities of ALT AST and LDH in serum were determined. Results Both of urine and serum fluoride of high fluoride people and dental fluorosis people were higher than those of the control moreover fluoride contents in urine and serum increased gradually with the increase of fluoride level in drinking water. No significant differences were seen in serum TP ALB ALT and AST levels among groups. Serum LDH activities significantly increased in dental fluorosis people from area of 2.58 mg/L fluoride in drinking water and in two groups from area of 4.51 mg/L fluoride. Moreover there was an obvious dose-effect relationship between the drinking water fluoride concentration and LDH activity. Conclusion If the concentration of fluoride in drinking water exceed 2.0 mg/L it will cause hepatic damage in children with an remarkable dose-effect relationship. The degree of hepatic damage is related to not only water fluoride level but also the condition with or without dental fluorosis.

Objective To accurately understand multi-spot medical practice in China and evaluate its effect.Methods Operation data of 2008 and 2009 were gathered from all medical institutions in Kunming to analyze the effect of the practice trial using the fixed effect model.Results Under control of such factors as the scale and type of the hospitals,clinic visits of the second certified hospital benefited by the practice increased by 14％than before,whereas the medical revenue of the institution increased by 29％.The effect proves more significant in terms of total clinic visits and medical revenues at level-1 and level-2 medical institutions.Conclusion Multi-spot medical practice in Kunming proves successful as it increased medical service supply and medical revenue,especially for level-1 and level-2 medical institutions.This effect possibly results from releasing high-level physicians down to lower-level institutions,helping these institutions to attract patients.

BACKGROUND: Clinical observation demonstrates that accelerated fracture healing or lower limb heterotopic ossifications always occur in patients with paraplegia. It indicates that peripheral nervous system may play an important role in fracture healing process.OBJECTIVE: To observe bone histomorphometery parameter, callus formation and biochemical change during the process of fracture healing of unilateral lower limb denervated tibia.DESIGN: Self-control animal experiment.SETTING: Tianjin Hospital.MATERIALS: Totally 36 six-month-old healthy male Wistar rats, with mean body mass of 210 g, were used in this experiment.METHODS: This experiment was carried out at Animal Experimental Center of Tianjin Hospital from March 2001 to March 2004. Denervated tibia fracture model and innervated tibia fracture model were made in the same rat. Animals were executed under anaesthetic status at week 2 and week 4 after fracture. Bilateral tibias were chosen to take radiografts.Biomachamical strength was measured and non-decalcification sections were prepared to perform bone histomorphometery observation.MAIN OUTCOME MEASURES: ① Comparison of wet weight of bilateral tibias and callus of rats between two groups after fracture. ②X-ray plain film scoring. ③ Biomechanical testing of tibial samples. ④ Histomorphological observation of fracture healing RESULTS: ① Wet weight of bilateral tibia and callus of rats in denervated group was much higher than that in innervated group at weeks 2 and 4 after fracture [(0.94±0.15) vs (0.76±0.14) g, (1.06±0.26)vs (0.81±0.10) g,P ＜ 0.05]. ②In X-ray plain film scoring, callus formation was significantly increased in denervated group (P ＜ 0.01). ③In biomechanical testing of three-point bending of tibial sample, callus intensity was significantly lower at weeks 2 and 4 after fracture in denervated group than in innervated group[ (9.88±8.49)vs ( 16.62±13.38 ) N, ( 12.77±7.55 )vs (20.19±10.60) N,P ＜ 0.05]. ④Bone histomorphometery showed that compared with innervated group, mineralized bone trabecula width of denervated group was significantly reduced (P ＜ 0.05), osteoid width was increased , osteoclast index and bone absorption area were significantly increased (P ＜ 0.05), and there were no significant difference of fibroblast index and bone formation area between two groups; Compared with innervated group, mineralized deposition rate in the denervated group was significantly reduced (P ＜ 0.05), the mature time of osteoid was elongated (P ＜ 0.05).CONCLUSION: Peripheral nervous system may play an important role during early and middle period of fracture healing. Intact innervation is essential for normal fracture healing.

Objective To explore the changs of serum brain type creatine kinase isoenzyme(CK-BB),cystatin C of newborns with hypoxic-ischemic encephalopathy(HIE) and assess their applications.Methods The serum concentrations of CK-BB and cystatin C were measured by turbidimertric immunoassay in 56 HIE newborns and 42 normal neonates.Results 1.Compared with controls,the concentration of serum CK-BB in moderate HIE newborns had significant differences(P