BACKGROUND:Bone tissue engineering is the most promising way to treat bone defects at present. The key problem is to construct vascular networks which can provide oxygen and nutrients for new bone, and thereby provide a way for the body metabolism. OBJECTIVE:To review the characteristics of bone tissue engineering scaffold materials and to introduce the development of composite scaffold materials. METHODS:With the key words of“bone tissue engineering, scaffold, vascularization, composite scaffold”in Chinese and in English, respectively, a computer-based search was performed for articles published in CNKI and PubMed databases from January 2001 to January 2014. After the initial screening, the reserved articles were further detailed, summarized and concluded. RESULTS AND CONCLUSION:According to the different sources, the bone tissue engineering scaffold materials can be divided into artificial materials, natural derivatives and composite scaffold materials. Single scaffold is difficult to be the most ideal material for repair of bone defects, while composite scaffold can make up for the defects of the single scaffold to different degrees. Therefore, in recent years, the bone tissue engineering scaffolds have developed from single to composite scaffolds and there is the trend of organic combination of artificial materials and natural derivatives. However, composite scaffolds have many problems to be solved in the clinical application. The main aspect is to control the proportion of the composite scaffold so that the degradation of materials can be matched with growth of tissues and cells. The other one is to keep the porous and high mechanical strength of the composite scaffold.

Objective To study different e mbolization methods in various aneurys ms with metallic coils. Methods In 6 spherical aneurysms, the e mbolization was p erformed with coils in their bodies, discontinuing the total or part of the bloo d supply to the corresponding viscera. While in 6 diverticulum aneurysms, the em bolization with coils was conducted in their bodies only, maintaining the blood supply of the corresponding viscera. For some pseudoaneurysms, both afferent and efferent arteries were embolized and collateral arterial supplies were prevente d. Results All 19 cases 20 aneurysms, of aneurysms were success fully embolized. Among 8 cases of pseudoaneurysms, bleeding had been stopped in 7 cases. Putting coils in the b odies of aneurysms or embolizing both afferent and efferent arteries improved su ccessful rate. Conclusion Embolizing aneurysms with metallic co ils is an efficient, reliable, and simple interventional method for stopping bleeding.

Objective To investigate the biocompatibility of pure titanium (Ti) and Ti-6Al-7Nb surface treated by sanding acid etch (SLA) on rat osteoblasts. Methods Experiments were divided into four groups, Ti mechanical grinding group (S1 group), Ti sand-blasting acid group (SLA1 group), Ti-6Al-7Nb mechanical grinding group (S2 group) and Ti-6Al-7Nb sand-blasting acid group (SLA2 group). The surface topography of samples was examined by microscope. The contact angle measurement instrument was used to analyse surface hydrophily of SLA1 and SLA2 groups. The surface sediment mor?phology and phase were observed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) in two groups after be?ing soaked into simulated body fluid (SBF) for 7 d,14 d and 21 d. Osteoblasts extracted from rats were seeded on titanium sheets, and the osteoblast cells on different titanium surfaces were observed by inverted microscope. MTT colorimetric meth?od was used to measure the proliferation of osteoblasts. Results Compared with S1 and S2 groups, there were more holes on sample surface of SLA1 and SLA2 groups. The sample surface was hydrophilic structure in SLA1 and SLA2 groups. The con?tact angle was smaller in SLA2 group than that of SLA1 group. The hydroxyapatite coating was firstly observed in SLA2 group at 14 d. The hydroxyapatite coating was found in samples of two groups after 21 d. The proliferative ability of osteo?blasts was stronger in SLA1 and SLA2 groups than that of S1 and S2 groups. And the proliferative ability of osteoblasts was stronger in sample surface of SLA2 group than that of SLA1 group (P<0.05). Conclusion Ti-6Al-7Nb by SLA has good biological compatibility, which is helpful to promote the combination of implant and bone tissue.

Objective To investigate the characteristics of upper airway collapse in patients with obstructive slcep apnea hypopnea syndrome (OSAHS) when muscle is fully relaxed.Methods Thirty male ASA Ⅱ or Ⅲ patients with OSAHS aged 20-59 yr with body mass index 21-36 kg/m2 and apnea-hypopnea index (AHI) of 28-102times/h were studied.The patients were sedated with iv midazolam 1 mg and sufentanil 5 μg.Nasotracheal intubation was then performed under topical anesthesia with 1％ dicaine.After confirmation of correct position of nasotracheal tube,anesthesia was induced with propofol 0.5 mg/kg and vecuronium 0.08 mg/kg and maintained with target-controlled infusion of propofol and remifentanil.BIS was maintained at 40-60.Fiberopticnasopharyngoscope and pressure transducer were inserted via contralateral nasal cavity and connected with imaging workstation.The site and length of the obstruction were measured and calibrated.Positive pressure was applied to the pharyngeal cavity and gradually increased in increments of 1 cm H2O until 20 cm H2O.The change in cross-section area and critical opening pressure at different planes in pharyngeal cavity were recorded.Results Complete obstruction occurred at the plane of hard palate in one patient (3％).The soft palate and uvula completely collapsed in all 30 patients (100 ％).The collapse occurred at tongue level in 23 patients (77 ％).Every 1 cm H2O increase in pressure produced increase in cross-section area by (10 ± 4)mm2 at the level of hard palate and by(28 ± 18) mm2 at the level of soft palate and uvula.The critical opening pressure ranged from 3 to 18 cm H2O and was≤ 15 cm H2O in 90％ patients.Conclusion Soft palate and uvula collapse in all patients with OSAHS when muscle is fully relaxed.The critical opening pressure is ≤ 15 cm H2O in 90％ patients.

Zinc is essential for cell proliferation and differentiation,especially for the regulation of DNA synthesis and mitosis.On the molecular level,it is a structural constituent of a great number of proteins including enzymes of cellular signaling pathways and transcription factors.Zinc can modulate cellular signal recognition,second messenger metabolism,protein kinase and protein phosphatase activities.It may stimulate or inhibit activities of transcription factors,and it may as well be used as a second messenger involved in cell signaling regulation.

Objective To investigate the level and influencing factors of nurses' professional growth,in order to provide evidence for promoting the satisfaction degree of nurses with their career and reducing nursing turnover rate.Methods A random sample of 526 clinical nurses from 6 third-level and firstclass hospitals in Tianjin were investigated with Career Growth Scale.Resalts The score of chnical nurses' professional growth averages was (2.44±0.53) points.Single factor analysis found that working purpose,the work-ing years and sex affected the total score of career growth and the score of each dimension statistically.Multiple linear regression analysis showed that working purpose was the greatest impact on the degree of the career growth score among influencing factors,followed by the working years and sex.Conclusions Nurses' professional growth is on the average level.All relevant departments should strengthen the construction of professional nurse,improve the promotion and salary system to strengthen the nurses' career growth,in order to enhance the nurse's career satisfaction,reduce the nurse turnover rate.

Objective To analyze the efficiency and specificity of MSP2 alleles genotyping for Plasmodium falci-parum isolates by Nest-PCR and PCR-RFLP. Methods MSP2 alleles from Plasmodium falciparum isolates of Yunnan and Hainan were genotyped by Nest-PCR and PCR-RFLP, respectively, and the efficiency and specificity of the two me-thods were analyzed. Results The conventional Nest-PCR method could detect 79.8% (166/208) alleles of MSP2,and 65.7% (65/99) for 3D7 family, but could not identify the type of any allele. While PCR-RFLP showed 25.3% higher genotyping efficiency than Nest-PCR. Moreover, this method could identify the allele types. Conclusion PCR-RFLP genotyping technique is more efficient and specific than conventional Nest-PCR, and it is a convenient tool in the study on molecular epidemiology of malaria.

Objective To investigate the influence of work-family support,self-efficacy and psychological safety climate on nurses' career growth,and to establish a model of this influence.Methods Totally 382 registered nurses were recruited from four third level and grade A hospitals in Tianjin.They were investigated with Career Growth Scale (CGS),Work-Family Support Scale (WFSS),General Self-Efficacy Scale (GSES) and Psychological Safety Climate (PSC).Results The total effect of work-family support on nurses career growth was 0.562 with the 95％ confidence interval at 0.502-0.641;Indirect effect was 0.121 with the 95％ confidence interval at 0.065-0.207,both of the effects were statistically significant.The effect of work-family support-psychological security atmosphere-self-efficacy and career growth path accounted for 45.1％ of the total indirect effect with 95％ confidence interval at 0.197-0.201;the effect of work-family support-self-efficacy and career growth path accounted for 54.9％ of the total indirect effect with 95％ confidence interval at 0.066-0.068,the intermediary effect were established.Conclusions This study established a structural equation model connecting work-family support,self-efficacy,psychological security atmosphere,career growth and enucleate their internal connection.The administrators of nurses should provide nurses with support on both work and life,and help nurse with their career growth through increases of self-efficacy and psychological safety climate.

The introduction of MOOC to medical education in China can greatly promote the development of modern medical education.Using the content analysis method,the paper systemizes the research literatures on MOOC published in 2013-2015 in China.According to the analysis,currently,the research on MOOC in China is still in the initial stage.Therefore,it proposes the focus of domestic research on MOOC and the research development direction in medical education in the future.