Exosomes are nano-vesicles released by many kinds of cells. Exosomes play a significant role in cell-to-cell communication and substance transportation through direct effect of signaling molecules on the cell membrane surface, intracellular regulation of cellular content during membrane fusion, or regulation of release of various bioactive molecules. Several studies have reported that culture supernatant of stem cells has some related exosomes to take part in wound repair. The secretion of exosomes is depended on the source and the physiological and pathological condition of deriving cells. How to stimulate the stem cells to produce exosomes maximally and their clinical application are worthy to explore. In this review, we summarize the biological function and application of exosomes derived from stem cells in wound repair.

Objective : To understand the current situation and influencing factors of occupational burnout among vaccination personnels in Haining. Methods : The vaccination staffs of all vaccination clinics in Haining were investigated by the general questionnaire and Maslach Burnout Inventory. Logistic regression model was used to analyze the influencing factors for job burnout of vaccination personnels. Results : A total of 160 questionnaires were distributed and 158 valid questionnaires were collected. The effective rate of questionnaires was 98.75%. A total of 91 vaccination staffs suffered from occupational burnout,accounting for 57.59%. Among them,the median（inter-quartile range）of the scores of emotional exhaustion,depersonalization and personal achievement were 13.00（14.00）,4.00（6.00）and 26.50（17.00）,respectively,which were all lower than the normalized scores（22.19,7.12 and 36.53,P<0.05）. The results of logistic regression analysis showed that having confidence in vaccination was a protective factor for emotional failure（OR=0.175,95%CI：0.058-0.523）and low sense of achievement（OR=0.272,95%CI：0.079-0.937）in vaccination personnels;having experience in adverse event following immunization（AEFI）was a risk factor for depersonalization（OR=3.125,95%CI：1.472-6.633）and occupational burnout（OR= 2.391,95%CI：1.189-4.807）in vaccination personnels. Conclusion A certain proportion of vaccination staffs in Haining suffered from occupational burnout. The experience of AEFI was a risk factor for their occupational burnout.

Objective: To investigate the differences in the intake of macronutrients between boarders and resident students in China, and to provide a scientific reference for relevant policies and preventive measures. Methods: The difference of macronutrients level between boarders and resident students were analyzed with the multilevel model (MLM) by using the data from Chinese Health and Nutrition Survey and the indicators of Chinese Dietary Reference Intakes (DRIs) 2013. Results: The daily intake of energy, carbohydrate, fat and protein were (1 597.59±557.15)kcal, (216.2±84.66)g, (57.88±31.96)g, (52.69±21.2)g respectively, with a rate of meeting DRIs of 17.32%, 84.17%, 50.30% for energy, carbohydrate and protein. There were significant differences in amount of energy, carbohydrate between boarders and resident students, but no significant difference in rate of meeting DRIs (15.09%, 87.28%, 17.54%, 83.86%, P>0.05 ). No difference in the amount of fat and protein intake between boarders and resident students, but the protein rate of meeting DRIs among resident students was significantly lower than that in boarders(34.91% vs 51.82%, χ2=4.45, P<0.01). Conclusion The results revealed an imbalanced intake of macronutrients among primary and secondary school students, which highlight the insufficiency in energy intake and the worse meeting rate of DRIs for protein among resident-student. The nutritional education targeting at boarder-students should be strengthened.

Purpose: Titanium implants are widely used in the treatment of dentition defects; however, due to problems such as osseointegration failure, peri-implant bone resorption, and periimplant inflammation, their application is subject to certain restrictions. The surface modification of titanium implants can improve the implant success rate and meet the needs of clinical applications. The goal of this study was to evaluate the effect of the use of porous titanium with a chitosan/hydroxyapatite coating on osseointegration. Methods: Titanium implants with a dense core and a porous outer structure were prepared using a computer-aided design model and selective laser sintering technology, with a fabricated chitosan/hydroxyapatite composite coating on their surfaces. in vivo and in vitro experiments were used to assess osteogenesis. Results: The quasi-elastic gradient and compressive strength of porous titanium implants were observed to decrease as the porosity increased. The in vitro experiments demonstrated that, the porous titanium implants had no biological toxicity; additionally, the porous structure was shown to be superior to dense titanium with regard to facilitating the adhesion and proliferation of osteoblast-like MC3T3-E1 cells. The in vivo experimental results also showed that the porous structure was beneficial, as bone tissue could grow into the pores, thereby exhibiting good osseointegration. Conclusions Porous titanium with a chitosan/hydroxyapatite coating promoted MC3T3-E1 cell proliferation and differentiation, and also improved osseointegration in vitro. This study has meaningful implications for research into ways of improving the surface structures of implants and promoting implant osseointegration.