Objective To probe the new mechanism of simvastatin on high-fat diet-induced kidney dam-age. Methods Female SD rats were subjected to a standard control diet(SCD)or high-fat diet(HFD)for 20 weeks,then the HFD group was randomly divided into HFD group and HFD group with simvastatin treatment (HFD+ST,10mg·kg-1·d-1 )for another 8 weeks. The expression of adiponectin,adiponectin receptors R1 and R2, Adenosine 5′-monophosphate(AMP)-activated protein kinase(AMPK),peroxisome proliferator-activated receptorα(PPARα),glucose regulated protein 78(GRP78)and GADD153(CHOP)in kidney were assessed respective-ly. Results Body weight and serum lipid levels in HFD group significantly increased ,expression of adiponectin and its receptors significantly down-regulated. Phosphorylation of AMPKα and PPARα expression decreased,and expression of GRP78 and CHOP up-regulated significantly. Above indexes in simvastatin treatment groups improved significantly. Conclusion Simvastatin can improve high-fat induced kidney damages ,probably by increasing expression of adiponectin and its receptors ,decreasing endoplasmic reticulum stress.

Aim To study whether the mechanisms in-volved in resveratrol′s protective effects on vascular en-dothelial injury induced by high-calorie and high-chol-estrol diet are concerned with ERS and the change of eNOS expression. Methods Twenty-four male C57BL/6 mice were randomly divided into standard control diet (SCD),high-calorie and high-cholestrol diet(HCD)and HCD group treated with resveratrol (HCD +RES,400 mg·kg -1 ·d -1 ,1 2 weeks).Then the thoracic aorta was separated,embedded and sliced to analyze the pathological changes by HE and resor-cinol staining.The protein distribution of eNOS was measured with immunohistochemical analysis.The up-stream and downstream genes of ERS in thoracic aorta were detected by RT-PCR.After the pretreatment with different concentrations of resveratrol,the mouse aortic endothelial cells (MAECs)were treated with palmitic acid,then the changes of cell proliferation in each group were compared.Western blot,immunofluores-cence and immunohistochemistry were used to deter-mine the protein expressions of GRP78,CHOP and eNOS respectively.Results Mice fed with HCD showed thickening of thoracic aortic wall and disorgan-ized elastic fibers as compared with those in SCD group.The mRNA levels of ERS related genes were all increased obviously (P <0.05),while the protein expression of eNOS was decreased.Compared with HCDgroup,the thickened wall and the disorganized elasticfibers were improved significantly,the mRNA levels ofERS related genes were all decreased obviously (P <0.05)and the expression of eNOS protein was increased in HCD +RES group.Compared with NCgroup, the cell proliferation was significantly decreased,meanwhile GRP78 and CHOP was significantly increased (P <0.05)and the protein expression ofeNOS was decreased in PA group.The cell proliferation was increased significantly (P <0.05),the mRNA and protein expression of GRP78 and CHOP wasobviously decreased (P <0.05),meanwhile the protein expression of eNOS was increased in the mediumand large dose of RES pretreatment groups.Conclusion Resveratrol has obvious effects of improving endothelial damages induced by HCD and decreasing cellproliferateion of MAECs induced by PA, and themechanisms are possibly related with decreased ERSand increased level of eNOS protein.

Objective To explore the clinical features and treatment of skin ulcers.Methods A total of 185 skin ulcer patients with clinical data was analyzed retrospectively in our hospital from October 2014-October 2016.Results Of the 185 patients with skin ulcers,84(45.4％) were 51-70 years old,diabetic ulcers were most common,and most occurred in ankle (44.3％) and limbs (35.7％).After further statistical analysis,the healing rate of patients treated by surgery was significantly higher than non-surgical patients.Surgical procedures of local flap transfer after ulcer resection were most commonly used and of the highest healing rate.The number of ulcers,the largest diameter of ulcers,scar ulcers and blood barrier ulcers were four factors that were independent of the outcome of skin ulcers.Conclusions Skin ulcers hospitalized patients are more common in patients over 50 years of age,occur most in the lower limbs.Surgical therapy is the preferred treatment for most ulcers,of which local flap transfer after ulcer resection has the best effect.Ulcer patients should actively treat the primary disease,strengthen the care,early diagnosis,and early treatment.

This paper aims to define the concept of autonomous learning and explore the purpose and significance of medical students' autonomous learning by combing the literature review at home and abroad in this field.Through analyzing the research progress and research methods of autonomous learning,this paper attempts to raise problems and provide countermeasures accordingly.In the current research of autonomous learning,researchers' perception of this study is insufficient.The scope of the current research is too limited and the research fields need to be further widened.In addition,the classification of disciplines in this subject is unbalanced and the coverage also needs to be further expanded.There are many theoretical studies but few empirical studies so far,and thus empirical research should be strengthened.

AIM:To investigate the effects of exercise preconditioning(EP)combined with electroacupunc-ture(EA)on learning and memory ability of rats with vascular dementia(VD),and to explore role of hippocampal ferrop-tosis in this process.METHODS:Seventy-two male SD rats were randomly divided into non-EP group and EP group,with 36 rats in each group.The rats were subjected to EP,and subsequently to establish the VD model.The rats from non-EP group were randomly divided into sham group,model group(VD group)and VD-EA group,each with 12 rats,while those in EP group were randomly divided into EP-sham group,EP-VD group and EP-VD-EA group,each with 12 rats.All rats in EP group underwent 4 weeks of swimming exercise training,5 d per week,30 min per day.At the end of the 4th week,the rats in VD,EP-VD,EP-VD-EA and VD-EA groups were used to induce the VD model,and the rats in sham and EP-sham groups received a sham surgery to simulate the VD model.On the 7th day after successful modeling,the rats in EP-VD-EA and VD-EA groups were treated with EA for 4 weeks,6 d per week,30 min per day.At the end of the inter-vention,the learning and memory ability of the rats was evaluated using Morris water maze.Neuron morphology in the CA1 area of rat hippocampus was observed through Nissl staining.Ferrous ion(Fe2+),malondialdehyde(MDA)and re-duced glutathione(GSH)contents in the rat hippocampal tissues were quantified using the colorimetric assay.The expres-sion levels of ferroptosis-related proteins,nuclear factor E2-related factor 2(Nrf2)and glutathione peroxidase 4(GPX4),in the hippocampal tissues were quantified by Western blot method.RESULTS:Compared with sham group,the rats in VD group exhibited longer mean evasion latency and decreased number of traversals across the plateau(P<0.01).The neurons in the CA1 region of the hippocampus were loose and disorganized,exhibiting an irregular cellular morphology.The hippocampal Fe2+and MDA content was elevated,and the GSH content was reduced(P<0.01).The protein levels of hippocampal Nrf2 and GPX4 were decreased(P<0.01).Compared with VD group,the rats in EP-VD,EP-VD-EA and VD-EA groups showed a shorter average escape latency and an increased number of traversals across the plateau(P<0.05).Neurons in the hippocampal CA1 area were more neatly arranged,showing regular cellular morphology.The hip-pocampal Fe2+and MDA contents of the rats in EP-VD group were significantly reduced(P<0.01),while the GSH content was elevated(P<0.05).Hippocampal Fe2+and MDA contents were significantly reduced and GSH contents were signifi-cantly increased in EP-EA and EA groups(P<0.01).The protein levels of hippocampal Nrf2 and GPX4 in EP-VD,EP-VD-EA and VD-EA groups were significantly increased(P<0.01).CONCLUSION:Exercise preconditioning combined with EA improves learning and memory ability in VD rats by reducing hippocampal intra-neuronal iron overload,maintain-ing organismal redox homeostasis,and inhibiting ferroptosis.