Problem-based Learning (PBL) is a teaching model originating from the construc-tivism theory, which stressed the meaning construction in problem situation by collaborative learning, conversation and completing knowledge. Based on the times background, development of learning theory, teaching situation, cognitive strategies, ideological connotation about constructivism, PBL's practical significance, its teaching forms, teaching resources, internal motivation, and the teaching evaluation were analyzed deeply, which was beneficial to carrying out PBL normatively in medical education, so as to provide the theoretical support for further exploration and innovation of PBL.

OBJECTIVE:To observe the efficacy and safety of prednisone combined with human immunoglobulin(pH4)for intra-venous injection in the treatment of idiopathic thrombocytopenic purpura. METHODS:85 patients with idiopathic thrombocytopenic purpura were divided into control group(42 cases)and observation group(43 cases). Control group received 1.6 mg/(kg·d)Predni-sone tablet,orally,for continuous 4 weeks;observation group received 400 mg/(kg·d)human immunoglobulin(pH4)for intravenous injection,intravenous injection,for continuous 5 d,then 1.6 mg/(kg·d)Prednisone tablet,orally,for continuous 4 weeks. All pa-tients were given Adrenal color hydrazone tablet,Vitamin C tablet and other conventional treatment. Clinical efficacy,platelet number, T lymphocyte subsets(CD3+,CD3+CD4+,CD3+CD8+,CD19+),TNF-α,IL-6 before and after treatment,time of platelet number reached normal and reached peak value,peak value of platelet number and the incidence of adverse reactions in 2 groups were ob-served. RESULTS:The total effective rate and peak value of platelet number in observation group were significantly higher than control group,time of platelet number reached normal and reached peak value were significantly shorter than control group,the differences were statistically significant(P<0.05). Before treatment,there were no significant differences in platelet number,T lymphocyte sub-sets,IL-6 and TNF-αlevel in 2 groups(P>0.05);after treatment,platelet number,CD3+and CD3+CD4+in 2 groups were significant-ly higher than before,and observation group was higher than control group,IL-6,TNF-αlevel,CD3+CD8+and CD19+were signifi-cantly lower than before,and observation group was lower than control group,the differences were statistically significant(P<0.05). And there was no significant difference in the incidence of adverse reactions in 2 groups(P>0.05). CONCLUSIONS:Prednisone com-bined with human immunoglobulin(pH4) for intravenous injection shows better efficacy than prednisone alone in the treatment of idio-pathic thrombocytopenic purpura,it can increase platelet number,adjust immune function,and do not increase the incidence of ad-verse reactions.

Objective:To explore the teaching evaluation of online open course of hematology based on small private online course (SPOC) platform by means of quantitative method.Methods:The fourth-year undergraduates of clinical medicine major were selected to receive online course learning of hematology, including video viewing, rich text browsing, in-class quizzes, and seminars. The teaching contents covered the basis of hematological diseases, anemic diseases, hematological tumors, bleeding and coagulation disorders. Teaching evaluation was conducted through teaching behavior assessment, unit test, course examination and SPOC scoring. Linear regression analysis was used to analyze the correlation between the duration of the teaching video and student learning behavior. The correlation between video learning quantity and viewing time and course test scores and SPOC scores was analyzed. Kruskal-Wallis test was used to compare the differences in curriculum learning behavior (participation rate). T-test was used to compare the differences between the two results of two unit tests and to calculate the alternative-form reliability. Chi-square test was used to compare the differences in scores of different sub-specialty questions in hematology, and the differences of participation rate of different examination points of hematological tumors. Results:The teaching video viewing rate was significantly higher than the participation rate of rich text browsing and in-class quizzes ( P < 0.001; P < 0.001). There was no obvious correlation between video duration and video viewing, rich text browsing, in-class quizzes ( R = 0.168, F = 0.81, P = 0.376; R = 0.057, F = 0.07, P=0.802; R=0.124, F=0.37, P=0.546). There was a significant positive correlation between the participation rate of video viewing and rich text browsing and in-class quizzes ( R =0.890, F=76.41, P<0.001; R=0.934, F=163.67, P < 0.001). The participation rate of anemic disease unit test was significantly higher than that of hematological tumors ( χ2 = 49.08, P<0.001), bleeding and coagulation disorders ( χ2= 25.97, P< 0.001), and the second results were significantly improved ( t=-2.09, P=0.040), and the alternative-form reliability was 0.750. There was no significant difference in the participation rate of different sub-specialty courses ( χ2=5.20, P=0.074); the number of video watching was significantly positively correlated with SPOC scores ( R=0.523, F=196.22, P<0.001); the participation rate of molecular genetics and molecular biology tests of blood tumor was significantly lower than that of general clinical information questions ( P < 0.05). Conclusion:Teaching videos are the foundation of online courses. Increasing the number of video viewing and improving video viewing rate can effectively mobilize the enthusiasm of extensive learning, such as rich text browsing and in-class quizzes, and improve learning participation. It is conducive to the improvement of students' academic performance. Simple behavior factors such as video viewing time are not recommended as performance evaluation indicators. Unit test takes two times to get the highest score, which is conducive to improving professional learning level through learning behavior, without affecting the reliability of the performance evaluation. The online open course based on the SPOC platform is conducive to the balanced development of the course teaching of Hematology.

Objective To evaluate the coupling relationship between segmental longitudinal strain and left ventricular volume at different phases of the cardiac cycle by two dimensional speckle tracking imaging. Methods 2D grey scale images of 41 healthy adults were acquired,and time curve of left ventricular volume (LVV),segmental longitudinal strain(LS)and segmental longitudinal strain rate(LSr)were outputed by analysis software.The correlations between LVV and LS or LSr in isovolumic relaxation time(IVRT),the rapid filling time(RFT),the atrial filling time(AFT)and the ejection time(ET)were analyzed respectively. Results ①IVRT:LS in basal segment,middle segment,apical segment of interventricular septum,in apical segment,basal segment of the lateral wall,and in middle segment of inferior wall were low-moderate negatively correlated with LVV;only LSr in middle segment of anterior wall was negatively correlated with LVV(P<0.05).② RFT:LS in middle segment,apical segment of interventricular septum,in apical segment of the lateral wall were negatively correlated with LVV;LSr in basal segment,middle segment, apical segment of interventricular septum,in apical segment,middle segment,basal segment of lateral wall, in middle segment,basal segment of inferior wall were low-moderate negatively correlated with LVV(P <0.05).③AFT:LS in basal segment of inferior wall,in apical segment,basal segment of the anterior wall were low negatively correlated wtih LVV(P <0.05).④ET:LS in basal segment,middle segment,apical segment of interventricular septum,in apical segment,basal segment of the lateral wall were low negatively correlated with LVV(P <0.05);only LSr in apical segment of lateral wall was negatively correlated with LVV(P<0.05).Conclusions LS or LSr in special segments of interventricular septum,lateral wall, anterior wall and posterior wall are actively participate in the volume change of the left ventricle in healthy adults,specific myocardial segments of left ventricular wall are involved in left ventricular volume changes.