基于虚拟仿真+CBL+TBL的混合式教学在“医学形态学实验”中的应用

目的探讨虚拟仿真实验项目与CBL及TBL相结合的混合式教学方法在“医学形态学实验”教学中的应用效果。方法以2016级和2017级选课学生为研究对象,随机分为对照组和实验组,对照组采用传统教学方法,实验组采用混合式教学方法,分别进行“医学形态学实验”教学;课程结束后,对学生进行问卷调查及综合考核,比较两种方法的教学效果。结果实验组学生的综合考核成绩显著高于对照组(P<0.05);问卷调查显示,实验组学生对混合式教学方法满意度较高(P<0.05)。结论在“医学形态学实验”教学中,混合式教学的教学效果明显优于传统教学方法。

Effect of Kaiyu Qingwei Jianji on the morphometry and residual strain distribution of small intestine in experimental diabetic rats

AIM： To investigate the effect of a Chinese medicine, Kaiyu Qingwei Jianji （KYQWJJ） used for diabetic treatment, on the morphometry and residual strain distribution of the small intestine in streptozotocin （STZ） -induced diabetic rats. Correlation analysis was also performed between the opening angle and residual strain with the blood glucose level. METHODS： Forty-two male Wistar rats weighing 220-240 g were included in this study. Thirty-two STZ- induced diabetic rats were subdivided into four groups （n = 8 in each group）, i.e. diabetic control group （DM）; high dose of KYQWJJ （T1, 36g/kg per day）; low dose of KYQWJJ （T2, 17 g/kg per day） and Gliclazide （T3, 50 mg/kg per day）. Another ten rats were used as nondiabetic control （CON）. The medicines were poured directly into stomach lumen by gastric lavage twice daily. The rats of CON and DM groups were only poured the physiological saline. Blood glucose and plasma insulin levels were measured. Experimental period was 35 d. At the end of experiment, three 5-cm long segments were harvested from the duodenum, jejunum and ileum. Three rings of 1-2 mm in length for no-load and zero-stress state tests were cut from the middle of different segments. The morphometric data, such as the circumferential length, the wall thickness and the opening angle were measured from the digitized images of intestinal segments in the no-load state and zerostress state. The residual strain was computed from the morphometry data. Furthermore, the linear regression analysis was performed between blood glucose level with morphometric and biomechanical data in the different intestinal segments. RESULTS： The blood glucose level of DM group was consistent 4-fold to 5-fold higher than those in CON group during the experiment （16.89 ± 1.11 vs 3.44 ± 0.15 mmol/L, P 〈 0.001）. The blood glucose level in the T1 （16.89 ± 1.11 vs 11.08 ± 2.67 mmol/L, P 〈 0.01） and T3 groups （16.89 ± 1.11 vs 13.54 ± 1.73 mmol/L, P 〈 0.05）, but not in T2 group （P 〉 0.05） was significantly lower than those in DM group. The plasma insulin levels of DM, T1, T2 and T3 groups were significantly lower than those in CON group （10.98 ± 1.02, 12.52 ± 1.42,13.54 ± 1.56,10.96 ± 0.96 vs 17.84 ± 2.34 pmol/L respectively, P 〈 0.05）, but no significantly difference among the groups with exception of CON group. The wet weight/cm and total wall thickness of duodenum, jejunum and ileum in DM group were significantly higher than those in CON group （wet weight （g/cm）： duodenum 0.209 ± 0.012 vs 0.166 ± 0.010, jejunum 0.149 ± 0.008 vs 0.121 ± 0.004, ileum 0.134 ± 0.013 vs 0.112 ± 0.007; Wall thickness （mm）： duodenum 0.849 ± 0.027 vs 0.710 ± 0.026, jejunum 0.7259 ± 0.034 vs 0.627 ± 0.025, ileum 0.532 ± 0.023 vs 0.470 ± 0.010, all P 〈 0.05）, T1 and T3 treatment could partly restore change of wall thickness, but T2 could not. The opening angle and absolute value of inner and outer residual stain were significantly smaller in duodenal segment （188 ± 11 degrees, -0.31 ± 0.02 and 0.35 ± 0.03 vs 259 ± 15 degrees, -0.40 ± 0.02 and 0.43 ± 0.05） and larger in jejunal （215 ± 20 degrees, -0.30 ± 0.03 and 0.36 ± 0.06 vs 172 ± 19 degrees, -0.25 ± 0.02 and 0.27 ± 0.02） and ileal segments （183 ± 20 degrees, -0.28 ± 0.01 and 0.34 ± 0.05 vs 153 ± 14 degrees, -0.23 ± 0.03 and 0.29 ± 0.04） in DM group than in CON group （P 〈 0.01）. TI and T3 treatment could partly restore this biomechanical alteration, but strong effect was found in T1 treatment （duodenum 243 ± 14 degrees, -0.36 ± 0.02 and 0.42 ± 0.06, jejunum 180 ± 15 degrees, -0.26 ± 0.03 and 0.30 ± 0.06 and ileum 163 ± 17 degrees, -0.23 ± 0.03 and 0.30 ± 0.05, compared with DM, P 〈 0.05）. The linear association was found between the glucose level with most morphometric and biomechanical data. CONCLUSION： KYQWJJ （high dose） treatment could partly restore the changes of blood glucose level and the remodeling of morphometry and residual strain of small intestine in diabetic rats. The linear regression analysis demonstrated that the effect of KYQWJJ on intestinal opening angle and residual strain is partially through its effect on the blood glucose level.

Experiment of dynamic property and transient magnetic effects of coal during deformation and fracture

Combining separated SHPB test device of Ф50 mm with ZDKT-type 1 transient magnetic resonance test system, long drop bar of 400 mm was used to impact coal specimens at four different speeds： 1.275, 3.287, 6.251, and 7.404 m/s. The change in waveform, the dynamic mechanical properties, and the generated effect of transient field during the coal deformation and fracture under the loads were discussed and analyzed. While magnetic signals during the coal fracture firstly needed EEMD, decomposition then had a FFT with Data Demon. The main results of the experiment are the following： the main frequency of magnetic signals was between 220 and 450 kHz and the instantaneous frequency during the damage of coal would have the instantaneous jump.

Morphological Research on Geometrical Scattering Waves of an Underwater Target

In this paper, a new method based on morphologic research named reconstruction cross-component removal （RCCR） is developed to analyze geometrical scattering waves of an underwater target. Combining the origin of the cross-component in Wigner-ViUe distribution, the highlight model of target echoes and time-frequency features of linear frequency-modulated signal can remove cross-components produced by multiple component signals in Wigner-Ville distribution and recover the auto-components of output signals. This method is used in experimental data processing, which can strengthen the real geometric highlights, and restrain the cross components. It is demonstrated that this method is helpful to analyze the geometrical scattering waves, providing an effective solution to underwater target detection and recognition.

MECHANISM OF PATHOLOGICAL CHANGES OF INTRAVENTRICULAR HEMORRHAGE IN DOGS

Objective To probe the mechanism of pathological changes of intraventricular hemorrhage(IVH). Methods The evaluation of neurological status,serial CT scans and pathological examination were applied on the canine model of IVH. The ventricular volume and blood clot volume were measured based on the CT images. Results The normal adult canine ventricle tend to be slitlike. After injection, the ventricle was obviously dilated by the blood clot. The linear regression of ventricular volume against blood clot volume was significant in the first week. From then on, however, while the clots continued to shrink, the ventricular volume showed progressive enlargement. The clots were lysed completely within 3 to 4 weeks. The linear regression of the degree of ventricular dilatation against the first clot volume was also significant. In the pathological examination, we found the ependymal lining of ventricular system was destroyed and neurons in the subependymal areas developed acidophil necrosis, which was prominent around Sylvian aqueduct. Conclusion Hemorrhagic ventricular dilatation(HVD) is a prominent feature of IVH and also is a strong indicator for poor prognosis. Ischemic changes of periventricular neurons in some important structures may be the most direct cause for poor outcome of IVH. It may be induced by periventricular vascular structures compressed by HVD, increased intracranial pressure, cerebral vasospasm and others.

Effect of probiotics on growth performance, development of small intestinal tract and microbial populations in broilers

The experiment was conducted using a total of 1392 one-day-old, Cobb commercial male broilers to investigate the effects of a commercial probiotic addition in diet on growth, the development of the small intestine and microbial populations of broilers. Broilers were randomly allotted by BW to 1 of 6 replicate cages （29 chicks per cage） for each of 8 treatments in a randomized block design involving one factorial arrangement of treatments. Dietary treatments included the basal diet （including corn, soybean, rapeseed, cottonseed meal） added with 100 mg/kg antibiotic, 0%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25% or 0.3%. The experiment last 42 d and divided into the starter period （1-21 d） and the finisher period （22-42 d）. The results showed that there were significant differences in broiler body weight （BW） （P〈0.001）, average daily feed intake （ADFI） （P=0.033）, relative length of the duodenum （P〈0.001）, jejunum （P=0.008）, ileum （P〈0.001） and the populations of lactobacillus （P〈0.001） and coliform （P〈0.001） in the rectum between the probiotics treatments and the control treatment only in the starter period of the trails. No significant differences were observed in intestinal morphology parameters in two periods of the experiment. Our results indicated that the probiotic was able to improve the performance of broiler chickens, and it was better in the starter period to be used than in the finisher period.

Pathomorphological changes after liver impact injury in rabbits

Objective: To investigate the histopathological changes in the liver and other organs after impact injury. Methods: The rabbits were impacted with a BIM IV biological impacting machine at the xiphoid process. The severity of liver injury was graded and scored through gross anatomy. At the same time, the pathological changes in the liver, heart, and lung were observed by light and electron microscopes. Results: Light microscopy showed that the pathological changes in the liver were: 1) loss of normal structure, hemorrhage and distortion of hepatic lobules; 2) cloudy swelling, degeneration, vacuolation and necrosis of liver cells; 3) infiltration of neutrophils. The lungs were injured and there were liver cell emboli in the small pulmonary arteries. Electron microscopy showed that the ultrastructure of the liver cells was severely damaged and the cells had significant features of necrosis. Conclusions: The major pathomorphological changes in the liver after impact injury are hemorrhage and necrosis. They may be complicated by exfoliation of liver cells to hepatic sinusoids. These cells circulate with the blood to form emboli in the pulmonary blood vessels.

An experimental investigation into electromyography, constitutive relationship and morphology of crucian carp for biomechanical “digital fish”

Currently, the integrated biomechanical studies on fish locomotion come into focus, so it is urgent to provide reliable and sys- tematic experimental results, and to establish a biomechanical ＂digital fish＂ database for some typical fish species. Accord- ingly, based on the control framework of ＂Neural Control - Active Contraction of Muscle - Passive Deformation＂, the elec- tromyography （EMG） signals, the mechanical properties and the constitutive relationship of skin, muscle, and body trunk, as well as morphological parameters of crucian carp, are investigated with experiments, from which a simplified database of bio- mechanical ＂digital fish＂ is established. First, the EMG signals from three lateral superficial red muscles of crucian carp, which was evolving in the C-start movement, were acquired with a self-designing amplifier. The modes of muscle activity were also investigated. Secondly, the Young＇s modulus and the reduced relaxation function of crucian carp＇s skin and muscle were de- termined by failure tests and relaxation tests in uniaxial tensile ways, respectively. Viscoelastic models were adopted to deduce the constitutive relationship. The mechanical properties and the angular stiffness of different sites on the crucian carp＇s body trunk were obtained with dynamic bending experiments, where a self-designing dynamic bending test machine was employed. The conclusion was drawn regarding the body trunk of crucian carp under dynamic bending deformation as an approximate elastomer. According to the above experimental results, a possible benefit of body effective stiffness increasing with a little energy dissipation was discussed. Thirdly, the distribution of geometric parameters and weight parameters for a single experi- mental individual and multiple individuals of crucian carp was studied with experiments. Finally, considering all the above re- suits, generic experimental data were obtained by normalization, and a preliminary biomechanical ＂digital fish＂ database for crucian carp was established.