Flipped classroom is an approach of basic medical education for undergraduate students

Background: With the development of medical education, new teaching method, such as flipped teaching model, was paid attention in the process. However, the sharing elaborate courses was used in the flipped teaching model in basic medicine has not been well investigated. Therefore, the aim of this study was to evaluate students’ learning effect of the histology and biochemistry between traditional teaching methods and flipped teaching method in the basic medicine classes to provide a scientific evidence of a new model establishment in the medical students’ education. Methods: 180 medical students at the Dalian Medical University were enrolled in the process. Hyperthyroidism was chosen for the content of this study. The participants were randomly allocated into the common teaching model group with the traditional lecture-based manner or the flipped teaching model group with the sharing elaborate courses manner. There are paper test, online test and lab test for histology and embryology after learning. The scores including total score, paper test score, online test score and lab test score were compared in two differernt teaching model and students were required to complete the questionnaire to evaluate the teaching model. Results: The scores of total, online and lab test with flipped teaching model were higher than those in common teaching model in histology and embryology. Additionally, the scores of total, paper and lab test with flipped teaching model were higher than those in common teaching model in biochemistry.The feedback of all items in the questionnaires were much positive. More students agreed and accepted the flipped teaching method could help to improve their performance. Conclusions: The medical students at Dalian Medical University can benefit from the flipped classroom teaching model, and a flipped classroom teaching model may well serve some subject areas such as histology and biochemistry. The flipped classroom approach can serve as a potentially exciting new modality for teaching model in the future.

teaching online learning system; 3) Teaching effect quality monitoring platform. 4) Virtual basic medical experimental teaching platform.

Participants
A total of 180 students majoring in clinical medicine from Dalian Medical University.They were enrolled in the studying the histology and biochemistry experiments. Some participants were randomly located into common(n=93) and flipped(n=87) group for histology and biochemistry. All students were unaware of their group assignments before class. The flipped teaching group is that students use the relevant teaching resources to learn outside the classroom firstly, and then the teachers and students cooperated to solve the problems that encountered in the study. The common teaching group is the traditional education model with the traditional lecture-based manner.

Data evaluation and statistical analysis
To evaluate students' understanding of course, the total score is consist of three parts including paper test(40%), online test(30%) and lab test(30%) for histology and embryology. However, the total score is consist of three parts including paper test(40%), online test(20%) and lab test(40%) for biochemistry. Results of the statistical analyses were presented as the mean ± standard deviation (± SD). The scores between two groups were analyzed using the t-test. All statistical analyses were performed using the SPSS 17.0 version and p-values of less than 0.05 were considered significant.
Besides, we also use the questionnaire to receive the feedback of the teaching method from students.

Flip learning resoure at Dalian Medical University
In our department, we established some elaborate courses sharing class network resources successfully. The resource was showed digital teaching website(figure1A)including theoretical teaching and experimental teaching. Online Classroom contained the video teaching online learning system (figure1B). Teaching effect quality monitoring platform and Virtual basic medical experimental teaching platform(figure1C&D).The resoure were taken advantage fully by students.

Teaching quality evaluation of flipped teaching mode in Histology and Embryology
The evaluation of flip teaching mode in Histology and Embryology was divided into two parts including the score grade analysis and grade division. In the score grade analysis, it was also consisted of total score, paper test score, online test score and lab test score. The results was showed in figure 2.
The total score of students in the common mode class is 83.87±11.22, and the total score of students in the flipped mode class is 86.70±10.01. There is a difference between the two groups (p<0.05) However, the average of papers test with no differences between common and flipped model (p>0.05)( figure 2B). The results analysis shows that the flipping teaching mode can greatly improve the enthusiasm of students' self-directed learning, effectively using time, significantly improve their academic performance, and improve the performance of teaching content supported by network resources.
We also compared the distribution of grades among students in the two teaching modes. The results are not showed here. In the different distribution of grades, there are some students. Moreover, the number of student is increasing with distribution of grades rising. Particularly, the excellent rate(the total score is more 90) in the flipped teaching group near to 50.57% is higher compared with common teaching group about 36.56%.

Teaching quality evaluation of flip teaching mode in biochemistry experiment
The evaluation of flip teaching mode in biochemistry experiment was divided into two parts including the score grade analysis and grade division. The results was showed in figure.3 The data in figure.3 above shows that the total score of 90 students in the normal mode class is 85.87±14.87, and the total score of 85 students in the flip mode class is 91.70±10.01. There is significant difference between the two groups (p<0.01). Analysis of paper test results: the average grade of the average mode class was 30.63±5.28, and the average grade of the flip mode class was 35.23±1.72. There was a significant difference between the two groups (p<0.01). Analysis of the The authors declare that they have no competing interests.   The score grade analysis of flipped teaching mode in Histology and Embryology. The total score(A), paper test score(B), online test score(C) and lab test score(D)of flipped teaching mode in Histology and Embryology.* p<0.05.