Constructivism teaching theory emphasizes the central role of student in learning and this theoretical framework holds that learning always builds upon the active exploring and discovering new knowledge.Department of orthopedics in the first affiliated hospital of Chongqing Medical University introduced and implemented constructivism teaching in teachers' research and teaching activity as well as in students' learning.This mobilized students' learning enthusiasm and improved clinical teaching quality.

Objective To investigate the interest,cognition degree,participation degree and current situation of the advanced undergraduate clinical students in our college,to discuss the reason for low level of students' scientific research quality,in order to provide the reference to making research training programs for them.Methods The advanced undergraduates of seven-year and five-year clinical program interned in orthopedics department from January to June in 2014 were selected with cluster sampling method,and investigated anonymously by questionnaires and interview.120 students were investigated by questionnaire,and 120 effective questionnaires were taken back.30 students were interviewed.Results The results showed that 90.0 percent (n=108) of students were interested in scientific activity,and 47.5 percent (n=57) of students had participated in scientific lectures.In interviews,students think factors hindering the research on the participation in scientific research are:1)too many courses and heavy school tasks;2) absence of relative knowledge;3) lack of support from college;4) tough condition for scientific training;5) immature management system.Conclusion The advanced undergraduate clinical students had great interest in scientific activity,but had few opportunities to take part in,leading to their low level of scientific research quality.A variety of measures should be taken to bolster their scientific training.

Objective:To study dynamic changes of fragile histidine triad(FHIT) gene expression in ionizing radiation injury and radiation carcinogenesis. Methods: BEAS-2B cells were divided into 0.5,1,2,4,8,16 Gy irradiation groups and control group. In 24 h, 72 h and 10 d after irradiation, the expression of FHIT gene was studied with single-cell RT-PCR and DNA sequencing separately. Results: Different types of FHIT gene mutations occured in different phases after irradiation with different doses (All mutations were exon deletion mutations by DNA sequencing), while abnormal FHIT gene was not detected in control group. The percentage of mutation in 0.5,1,2,4,8,16 Gy dose groups was 52.6%,66.7%,57.9%,76.5%,64.7% and 81.3% respectively 24 h after irradiation;17.6%,22.2%,50.0%,47.4%,47.1% and 68.4% respectively 72 h after irradiation;and 21.1%,25.0%,60.0%,57.9%,61.1% and 68.4% respectively 10 d after irradiation. Conclusion: These results suggest that ionizing radiation can cause deletion of FHIT gene.

Objective: To inquire into the testis gene change of mouse model with kidney-yang deficiency induced by overfatigue and excessive sexual life, the modern science mechanism of syndrome of kidney-yang deficiency and kidney controlling reproduction can be revealed on the gene level. Methods: The model of kidney-yang deficiency was established by each male mouse with six female mice keeping in the same cage, and all the male mice were forced to swim for 30-40 minutes everyday lasting for four weeks. The testis genes of mice in control group and model group were detected with Mouse OneArrayTM Whole Genome DNA microarray. The differentially expressed genes were screened under the condition of the relative fluorescence intensity ratio of the two groups ≥2 and ≤0.5 and further classified according to gene function by using Molecule Annotation System (MAS) created by CapitalBio Corp. Beijing, China. Results: The mouse model with kidney-yang deficiency was established successfully by the method of overfatigue and excessive sexual life. The scatter plot of gene expression profiles of comparing control group with model group was drawn. Differentially expressed genes were screened, including 2425 up-regulated genes and 3080 down-regulated genes. Among the first one hundred up-regulated genes, 41 genes were known and among the first one hundred down-regulated genes, 62 genes were known. These genes were mainly related to the cellular structure/function, material/energy metabolism, signal transduction/transmission, inflammation/immunization, cell apoptosis, transcription/translation,proliferation/differentiation and cell cycle. Conclusion: The testis gene of kidney-yang deficiency mouse had a wide change. The essence of kidney-yang deficiency syndrome and the theory of the kidney originating and controlling life reproduction were explained on the gene level.

Objective To preliminarily study the effect of high concentration prolactin (PRL) on the immune system in schizo-phrenic patients by analyzing the changes of lymphocyte subsets and immunoglobulins (IgG ,IgM ,IgA) levels .Methods The flow cytometry was used to detect the T lymphocytes CD3+ ,CD4+ and CD8+ subsets ,NK cell percentages and CD4+ /CD8+ ratio re-spectively .The three humoral immune indicators(IgG ,IgM ,IgA) in peripheral blood were detected by using the immunoturbidimet-ric turbidimetric method .The data were analyzed by adopting the analysis of variance .Results Compared with the healthy control group and schizophrenia normal PRL group ,T lymphocytes CD4+ subsets percentages and CD4+ /CD8+ ratio as well as IgG were increased in the schizophrenia PRL increase group(P<0 .05) ,while the percentage of NK cells was decreased(P<0 .05) .Conclu-sion High concentration PRL may have a certain effect on the immune system by influencing the balance among lymphocyte sub-sets and the production of immunoglobulins .

Objective:To investigate the relationship between the distance from the upper and lower resection margin and the gastric cancer patients with R0 resection and no distant metastasis.Methods:Retrospective analysis of 281 patients with gastric cancer in our hospital,the relationship between the age,sex,tumor size,tumor size,vascular invasion,lymph node metastasis,TNM stage,type of gastric cancer,tumor location and operation mode was analyzed.To compare the survival time of patients with different upper and lower margins.Results:The increase of the distance from upper resection margin was significantly related to the tumor size＞5 cm,TNM stage,type of gastric cancer,tumor location,and the difference was statistically significant(P＜0.05);The distance of lower resection margin was significantly correlated with tumor size＞5cm,vascular invasion,lymph node metastasis and TNM stage,type of gastric cancer,and the difference was statistically significant (P＜0.05);Themedian survival timein patientsof upper resection marginr□3cm with 48 months of the 5-year follow-up period was significantly higher than that in patients of the resection margin＞3cmwith 46 months (P＜0.001).Themedian survival timein patientsof lower resection margin□3cm with 45 months of the 5-year follow-up period was significantly higher than that in patients of the resection margin＞3cm with 44 months (P＜0.001).Conclusion:Gastric cancer postoperative upper and lower resection margin was significantly related with tumor size,TNM staging factors,and the median survival time of upper and lower resection margin＞5 cm was significantly lower than that of the resection margin3 cm.

Abstract? AlM: To evaluate macular thickness and macular volume changes in people with diabetes mellitus but no significant decrease of visual acuity.?METHODS:A total of 87 eyes were collected in diabetic group. According to the international stage of diabetic retinopathy, these cases were divided into two subgroups:DR0 stage 54 eyes and DR1 stage 33 eyes. All the cases were received optical coherence tomography (OCT) scan in macular area;the scanning model is 512× 128; recording macular average thickness and macular volume, and compared with healthy subjects.? RESULTS: Macular average thickness and macular volume were higher in DR1 group than those in DR0 stage and control group, and differences were having statistical significance. But DR0 group and control group differences of the two indexes were not statistically significant.? CONCLUSlON: With the aggravation of diabetic retinopathy, the macular thickness tends to be thicken. Although without obvious visual loss, there have been slight morphological changes. Using OCT scan can find fundus changes earlier in patients with diabetes mellitus, and provide clinical basis for both early diagnosis and treatment.

The durability of denture base resins with a new type of organic-inorganic hybrid coating was examined after long-term water im-mersion.After water immersion for 1 80 days at constant temperature of 37 ℃ the flexural strength and elastic modulus of the samples with the coating were qualified with the national standerds,the controls were not.

Background Carotid stenosis is one of the important causes of ocular ischemic diseases,To study their relationship is helpful for us to classify and manage the ocular ischemic diseases.Objective This study was to investigate the correlation between ocular ischemic diseases and carotid stenosis.Methods Twenty patients with internal carotid artery stenosis rate more than 60％ defined by digital subtraction angiography(DSA) or magnetic resonance angiography (MRA) were selected,including 9 patients with lateral carotid artery stenosis and 11 patients with bilateral carotid artery stenosis.The best corrected visual acuity,intraocular pressure and fundus examinations were carried out,and the peak systolic velocity (PSV) and end diastolic velocity (EDV) of the central retinal artery(CRA) were detected with color doppler flowimaging (CDFI).The resistance index(RI) was calculated by the formula RI =PSV- EDV/PSV.The correlation between internal carotid artery stenosis rate and PSV or RI was evaluated by Spearman rank correlated analysis.Results The subjective inanifestations included transient amaurosis in 77.4％ frequency and visual blur in 22.6％ frequency in the 31 carotid artery stenosis.Twelve eyes(38.7％ ) appeared the ocular vascular abnormality.Other 2 patients were diagnosed as hypoperfusion retinopathy complicated by neovascular glaucoma.A negative relationship was found between internal carotid artery stenosis rate and PSV of CRA ( r =-0.41,R2 =0.168,P =0.021 ＜0.05 ),but no significant relationships was found between internal carotid artery stenosis rate and RI ( r =- 0.26,R2 =0.068,P =0.159 ).Conclusions Carotid artery stenosis can cause the of ocular ischemic symptoms.The characteristics of retinal hemodynamics is the type of low speed and normal resistance.

In order to ensure the normal teaching order during the prevention and control of the COVID-19 epidemic, the second semester of the 2019-2020 academic year in Central South University was devoted to the online teaching. In response to the school's call, the diagnostics teaching team has applied the Tencent classroom software, WeChat mini programs, analog teaching software and digital curriculum platform to carry out online teaching activities. On the basis of summarizing the previous online teaching experience, we have made a preliminary discussion and reflection on the online teaching, which will provide ideas and directions for the reform of medical education.