There are some problems in the teaching of medical physics course,such as low learning initiative,deficient grasp of concept,and obstacles to realize the internalization and practical application of knowledge.The PAD (presentation-assimilation-discussion) class is applied in the course,in order to improve the students' learning state.PAD class is a teaching mode proposed from a psychological point,which advocates that teaching is the first before students start to learn and has an equal treatment on students' discussions and teachers' instruction,supporting independent learning.The teaching measures include:selecting course content to reach the balance between simplification and detailed interpretation;assigning open homework based on the course;dividing the class discussion into four steps;assessing students based on the performances of homework and final examinations.The research has shown that the PAD class facilitates improving the students' initiative of study and promoting the absorption and application of knowledge.

Objective To observe the role of brain-derived neurotrophic factor (BDNF) in the plasticity of enteric nervous-smooth muscle system,and to investigate the effects of BDNF induced plasticity on gastrointestinal motility in mice.Methods Male hybrid BDNF knockout (BDNF+/) mice and wild type (BDNF+/+) mice were selected,eight in each group.Gastrointestinal motility of BDNF+/+ mice and BDNF+/ mice were tested and compared.Longitudinal muscle strips of mice colon smooth muscle were prepared.The effects of carbachol (1 × 10 5 mol/L) and BDNF (1 × 10 7 mol/L) on contractile function of muscle strips were observed.And the effects of tetrodotoxin (TTX,1 × 10-6 mol/L) on BDNF induced contractile function of muscle strips were also studied.The changes of the density of mice intestinal myenteric plexus and the expression of smooth muscle α-actin (α-SMA) in colon smooth muscle were detected by immunohistochemical techniqne.The ultrastruetural alterations of myenteric plexus,neuromuscular junction (NMJ) and smooth muscle cells were detected by transmission electron microscope (TEM).T-test or Rank sum test was performed for comparison between groups.Results Number of feces particles and water content in feces of BDNF+/-mice ((3.80±0.75) and (39.60±1.47)％) were both lower than those of BDNF+/+ mice ((6.30± 1.03) and (51.00± 1.61) ％),and the differences were statistically significant (t=4.792,12.827;both P＜0.05).Carbachol (1 × 10-5 mol/L) could significantly increase contraction activity of smooth muscle of BDNF+/+ mice (R =3.26 ± 0.43) and BDNF+/-mice (R=2.15 ± 0.36),and the difference was statistically significant (t=15.754,9.632;both P＜0.05).The effects on contraction exciting of smooth muscle strips of BDNF+/+ mice were more significant than BDNF+/ mice,and the difference was statistically significant (t =5.972,P＜0.05).BDNF could significantly increase contraction of muscle strips of BDNF+/+ mice and R value increased from 1 to 1.41±0.09,and the differences were statistically significant (t=13.674,P＜0.05).TTX could obviously inhibit the excitatory effects of BDNF,R value decreased from 1.41 ± 0.09 to 1.03 ± 0.04 (t=11.692,P＜0.05).The density of myenteric plexus of BDNF+/ mice (median 5.8％,interquartile range 4.2％-7.0％) was significantly lower than that of BDNF+/+ mice (median 9.0％,interquartile range 7.1％-10.8％),and the difference was statistically significant (Z =3.730,P＜ 0.05).The expression of α-SMA of BDNF+/-mice (median 33.4％,interquartile range 28.8％-38.5％) was significantly lower than that of BDNF+/+ mice (median 44.6％,interquartile range 39.2％-48.8％),and the difference was statistically significant (Z=4.565,P＜0.05).The results of TEM indicated ultrastructural alterations of myenteric plexus,NMJ and smooth muscle in BDNF+/-mice.Conelusionss BDNF could induce the plasticity of morphology and function in enteric nervous-smooth muscle system,which may play an important role in mice gastrointestinal motility.

Obiective To construct the manageable, stable and reliable computer terminal environment for the hospital. Technology was successfully applied to the outpatient doctor workstation and the student electronic reading room in one hospital, and the system was running well.Conclusion The technical application can not only ensure the system security and stability, but also realize centralized management and improve efficiency.

Objective To study the level changes of matrix metalloproteinase-9 (MMP-9)and its clinical significance in patients with progressive ischemic stroke(PIS).Methods 136 cases of acute ischemic stroke including 46 cases of PIS and 90 cases of non-PIS,were studied.56 healthy subjects were selected into control group.MMP-9 level was measured by ELISA at 2,7 and 14 day after admission.The neurologic dysfunction score was observed.Results The MMP-9 level was ( 249.43 ± 63.76)μg/L,( 271.50±72.08 )μg/L,and (183.20 ±66.69)μg/L in PIS group,while it was (158.81±49.18 )μg/L,( 188.67±57.96 )μg/L,and ( 93.86 ±22.16)μg/L in non PIS group and was (88.60±15.93 )μg/L in control group at 2,7 and 14 days of admission.The MMP-9 level of PIS group at 2,7 and 14 day and the level in non PIS group at 2 and 7 day were higher than that of control group(P＜0.01 ).The MMP-9 level of PIS group was higher than that of different phrase of PIS group (P＜0.01 ).Linear X2 showed that the increase of MMP-9 level would increase the risk of ischemic stroke progression( X2=38.96,P＜0.01 ).Conclusion The remarkable increase of MMP-9 in patients with progressive ischemic stroke may be the indepent risk factor of the progression of ischemic stroke.

Objective To study the effect the edaravone on the expressions of ICAM-1,TNF-α after focal cerebral ischemia reperfusion in male rats.Methods 45 male SD rats were selected and randomly assigned into 3 groups:sham operation group(SO),ischemia reperfusion group(I/R),and edaravone treatment group(ED),each group had 15 rats.The expression of ICAM-1,TNF-α were checked by immunohistochemistry.All data in the groups were analyzed with t test.Results The expression of ICAM-1 and TNF-α in the I/R group and ED group were higher than the SO group(t=21.919,27.758,26.576,17.395,32.821,43.021,14.195,31.828,21.201,10.195,25.768,17.900,all P＜0.05)at reperfusion 3 hours,6 hours,and 12 hours.The expression of ICAM-1 and TNF-α in the I/R group were higher than the ED group(t=9.623,13.845,7.201,11.313,all P＜0.05)at reperfusion 3 hours and 6 hours.Conclusion Edaravone may exert the neuroprotective effect against the cerebral ischemia in rats by decreasing the expression of ICAM-1 and inhibiting the activation of TNF-α.This process could inhibit free radical generation.

Objective To compare the effect of levosimendan and milrinone on treatment of severe heart valve disease patients with postoperative low cardiac output syndrome. Methods Fifty-six severe heart valve disease patients with postoperative low cardiac output syndrome were selected, and the patients were divided into levosimendan group and milrinone group according to treatment method with 28 cases each. Both groups received symptom-relieved therapy, including cardiotonic, diuresis and other drugs. The patients in levosimendan group were combined with 24 h of continuous intravenous injection of levosimendan 0.05-0.20 μg/(kg·min) for 1 week, and the patients in milrinone group were combined with 24 h of continuous intravenous injection of milrinone 0.25-1.00 μg/(kg·min) for 1 week, in order to maintain mean arterial pressure ≥ 65 mmHg (1 mmHg=0.133 kPa). The cardiac output, cardiac index, left ventricular ejection fraction (LVEF), and the serum levels of lactic acid, creatinine, N-terminal pro brain natriuretic peptide (NT-proBNP) were compared between 2 groups. Results There were no statistical differences in cardiac output, cardiac index, LVEF, and the serum levels of creatinine, lactic acid, NT-proBNP before treatment between 2 groups (P>0.05). The cardiac output, cardiac index, LVEF, and the serum levels of creatinine, lactic acid and NT-proBNP after treatment in 2 groups were significantly better than those before treatment, and there were statistical differences ( P<0.05). There were no statistical differences in cardiac output, cardiac index and LVEF after treatment between 2 groups (P>0.05). The serum levels of creatinine, lactic acid and NT-proBNP after treatment in levosimendan group were significantly lower than those in milrinone group: (102.82 ± 21.31) μmol/L vs. (115.64 ± 58.73) μmol/L, (1.7 ± 1.4) mmol/L vs. (2.2 ± 1.0) mmol/L and (1 149 ± 515) ng/L vs. (1 321 ± 472) ng/L, and there were statistical differences (P<0.05). Conclusions Both the two drugs can significantly improve cardiac function in severe heart valve diseases patients with postoperative low cardiac output syndrome, while the levosimendan has more advantages in lowering serum creatinine, lactic acid value and NT-proBNP.

Objective To observe the effects of modifiedDanshen Decoction on spermidine/spermine acetyltransferase (SSAT) /polyamine pathways of SD rats with IRI; To investigate its protective mechanism. Methods The model of IRI was established by ligating left anterior descending coronary artery for 30 min followed by reperfusion for 90 min. The SD rats were randomly divided into the control group, sham-operation group, model group and modifiedDanshen Decoction group, with 10 rats in each group. The myocardial infarction size was measured by using TTC staining. The contents of SSAT were measured by ELISA. The SSAT mRNA and SSAT protein expression level were detected with real-time fluorescent quantitative PCR method and Western blot, respectively. The contents of polyamines (putrescine, spermidine, spermine) in cardiac tissue were detected by HPLC. Results Compared with sham-operation group, the myocardial infarction size, the SSAT content, the SSAT mRNA and SSAT protein expression levels of model group increased significantly, the contents of polyamines decreased significantly, with statistical significance (P<0.01); Compared with model group, the myocardial infarction size of modifiedDanshen Decoction group was significantly reduced, while the SSAT content and SSAT mRNA and protein expression level decreased significantly, the contents of polyamines increased, with statistical significance (P<0.05, P<0.01).ConclusionModifiedDanshen Decoction can adjust the SSAT polyamine pathways and increase polyamine content in cardiomyocytes, and thus play a role of protection of myocardial ischemia-reperfusion injury.

0bjective To establish a standard curve method with more accuracy employed in fluorescence real-time PCR(RT-PCR)as a alternation of the general method.Methods β-actin and KLK11 plasmid DNA for quantitative standard curve were constructed in our study,and Plasmids of β-actin was employed as a internal control.After serial dilution these plasmid were used as DNA standard to obtained slope.Expression of these two genes in malignant prostate cancer cell line LNCAP were tested by real-time PCR,and we analyzed the RT-PCR results with two different methods and compared their accuracy.Results Thestandards curves made from these linear DNA standards showed good linearity (R2=0.991 and 0.992 for β-actin and KLK11 standards graphs),but also displayed a discrepancy in their PCR efficiency(β-actin 123% and KLK11 99%).There were different results after two different stand curve analytical method:the expression of KLK11 mRNA in LNCAP was downregulated in general standard curve method.In the new analytical method,howerer,KLK11 upregnlated for 4.46-fold.And there was a significant difference between aplification efficiency of targt gene and internal control gene(t=4.829,P<0.05).Conclusions Compared with general standard curve method,the new advanced standard curve method described here avoids an error which considers there is identical amplification efficiency between target gene and internal reference gene.It is considered to be a more correct analytical method in fluorescence real-time PCR.

Objective:To discover the epidemic characteristics of brucellosis in Yunnan Province, and establish a grey GM (1, 1) model to predict brucellosis in Yunnan Province.Methods:The epidemic data of incidence rate of brucellosis and population data in Yunnan Province from 2008 to 2018 were collected from China Disease Prevention and Control Information System and Yunnan Provincial Bureau of Statistics. Epidemiological characteristics (including time, area and population distributions) were analyzed, and grey GM (1, 1) model was used to predict the incidence of brucellosis in Yunnan Province in 2019 and 2020.Results:A total of 1 216 brucellosis cases were reported in Yunnan Province from 2008 to 2018, with an average annual incidence rate of 0.237 4/100 000, showing an increasing trend year by year (χ 2trend = 843.34, P<0.01). Case reports were mainly from March to September, accounted for 69.41% (844/1 216) of the total number of cases. The top five regions with case reports were Honghe (289 cases), Qujing (264 cases), Kunming (258 cases), Dali (160 cases), and Yuxi (134 cases), accounting for 90.87% (1 105/1 216). The occupation was mainly farmers, accounting for 79.03% (961/1 216). A grey GM (1, 1) model was established to predict the incidence of brucellosis in Yunnan Province in 2019 and 2020, which was 0.487 6/100 000 and 0.481 7/100 000, respectively. Conclusion:The incidence of brucellosis in Yunnan Province has increased compared with that of the past, and targeted prevention and control should be carried out in key areas and key populations, and the prediction results should be prospectively evaluated to gradually improve the establishment of brucellosis prediction model in Yunnan Province.

Objective To summarize and analyze the pathological characteristics of solid pseudopapillary tumor of pancreas (SPTs).Methods The clinical data of 51 cases of SPTs were retrospectively analyzed.The immunohistochemical localizations of different markers (HSE,SYN,CD_(56),CD_(10),Nestin,Vim,a1-ACT,EMA,AE1/AE3 and CK19) on 39 SPTs were studied.Results Pathological features included a combination of solid and cystic components with pseudopapillae formation and degenerative regions without glands.Among the 39 cases of SPTs,the expression rate of NSE was 97.4%,the expression rate of CD_(56),CD_(10) was 84.6%,the expression rate of Nestin and Vim was 64% and 87%,the expression rate of S100 was 79.5%,the expression rate of a1-ACT and a1-AT was 82.1% and 79.5%,while the expression rate of SYN was 12.8%;however there was low expression and weak positive reaction of EMA,AE1/AE3 and CK19.Conclusions The typical pathological characteristics of SPTs may result from gradual degenerative changes induced anoxemia in some SPT's areas.The heterogeneity of SPTs on different antibody markers showed that the SPTs may be originated from pancreatic embryonic stem cells,and result from immature differentiation of the pluripotential stem cells during pancreatic genesis.