ABSTRACT
The First Affiliated Hospital of Xi'an Jiaotong University has established pediatric MOOCs courses, including the formation of excellent MOOC teachers, the curriculum planning and design of MOOCs, making MOOCs videos, and using MOOCs for teaching activities. The MOOCs for teaching is intuitive, the courses are interesting, and the learning time is flexible. Besides, it is open and resources-sharing, and it also can increase the educational equity. At the same time, it can reduce teachers' burden, improve teaching ability, and improve learning ability of students. Most students and teachers agree that MOOCs are worthy of promotion and application.
ABSTRACT
Objective To study the relationship between aquaporin 9 (AQP 9) gene and brain edema in neonatal rats of hypoxic-ischemic brain damage (HIBD) and the therapeutic mechanism of mannitol.Method Healthy and 7-day-old SD rats were randomly assigned into three groups:sham-operated group,HIBD group and mannitol group.Both HIBD and mannitol group were established on HIBD model.The mannitol group was given mannitol intraperitoneally at 0,24,48 h of HIBD.2 ml/kg of 2％ Evans blue (EB) were injected intraperitoneally before sacrifice.0,6,12,24,48 and 72 h after HIBD,the outcomes were analyzed including the brain water content,the expression of AQP 9 mRNA measured using RT-PCR and immunofluorescence staining methods,and the permeability of blood-brain barrier (BBB) measured with EB.Result In HIBD group,the brain water content was higher comparing with sham-operated group at 0 h after HIBD(P ＜ 0.05),and gradually increased over time,reaching peak at 48 h (89.3％ ± 1.9％) and then decreased.In mannitol group,brain water content started to decrease from 1 h after mannitol administration to the bottom at 12 h (86.5％ ±0.6％),then increased to peak at 72 h (87.2％ ± 1.7％),and brain water content were decreased during 0 ～ 48 h comparing with HIBD group.HIBD group's EB were higher than sham-operated group (P ＜ 0.05);Mannitol group's EB were decreased comparing with HIBD group (except 0 h,P ＜ 0.05).AQP 9 mRNA expression in the HIBD group was decreased at 0 h,and reached the bottom at 48 h (0.09 ± 0.07).Comparing with sham-operated group,it was higher in the HIBD group at0,6,72 h,and lower (P＜ 0.05) at 12,24,48 h.Higher AQP 9 mRNA expression were detected in mannitol group than HIBD group and sham-operated group at each time point (with the exception of 48 h) (P ＜ 0.05).AQP 9,which was closely related to water metabolism,were widely found in the pia mater and ependyma using immunofluorescence staining.After ischemia and hypoxia insult,an increasedecrease-increase pattern of AQP 9 expression was found.Conclusion AQP 9 is widely existed in various parts of the brain,influencing brain edema through a variety of pathways.AQP 9 also plays a role in alleviating brain edema in mannitol therapy.
ABSTRACT
BACKGROUND:Nano-hydroxyapatite as a surface modification material that is bonded to the surface of the zirconia ceramics upon sintering at high temperature can improve bone-inducing activity and bone bonding strength of the zirconia ceramics. Moreover, the sintering temperature is crucial for performance and bonding of the composite. OBJECTIVE:To detect the shear strength of nano-hydroxyapatite ceramics coating bonded to zirconia ceramics at different sintering temperatures. METHODS:Nano-hydroxyapatite slurry was prepared using sol/gel technology. Thereafter, 20 zirconium green bodies were coated with nano-hydroxyapatite slurry and randomly divided into four groups. Then, the specimens were put into non-pressure sintering furnace and sintered at 1 300, 1 400, 1 500, and 1 550℃, respectively. At last, we measured the shear strength of al the specimens after sintering by universal testing machine, and analyze the type of fractures. RESULTS AND CONCLUSION: With the rising of sintering temperature, the shear strength of the specimens was gradualy increased, and there were significant differences between the four groups [(4.04±1.19), (6.60±0.95), (16.51±1.93), (80.47±19.31) MPa,P < 0.05]. Within the scope of 1 550℃, the sintering temperature was positively relative to the shear strength of specimens. These findings indicate that in the certain temperature range, the higher the sintering temperature, the greater the shear strength of the bonding interface between zirconia and nano-hydroxyapatite. When the sintering temperature is 1 550℃, the shear strength of the bonding interface is the highest.
ABSTRACT
Objective Through the practice of new practice teaching methods, to observe whether it can help students to strengthen their self-identity as ‘trainee doctors’. Methods By sim-ulating interrogation, building simulation medical environment and increasing operation project, the practice operation abilities and sense of identity were improved,The questionnaire were required to fill in at the beginning and at the end of the term, and the differences between two teaching methods in advantages, characteristics and the identity of ‘trainee doctors’by their own pairing were compared. Data were analyzed by software SPSS 18.0. Results The new teaching model, to a certain extent, alleviated the present situation of having relatively more students and insufficient source, which was superior to traditional teaching mode in improving students' initiative, enthusiasm, learning ability, practical ability, analysis of the problems, comprehensive ability and so on. It also enabled students to master some of doctor-patient communication skills(P<0.001), to realize the identity of‘trainee doctors’ (Z=-7.671, P<0.001). Conclusion The new practice teaching mode has solved the problems such as insufficient source in clinical teaching. It has also increased the initiative and enthusiasm of students' clinical learning, so that students can think, analyze and deal with the problems from the point of view of doctors, and implement the identity of a‘trainee doctor’.
ABSTRACT
Dental composite resin is a kind of material which has been widely used in dental restoration. Research has found that the influence of residual monomer on the material mechanical, chemical and biological properties cannot be ignored. This paper elaborates these harms of residual monomers. The effects of resin matrix, inorganic filler and initiating system, illumination, secondarily treatment on the degree of conversion were also analyzed. The paper also discusses the effective measures to increase the conversion, and offers theoretical basis for the clinical application and development of composite resin.