Objective To study the effect of leaf movement speed on the setup error of multileaf collimator (MLC) in RapidArc mode,and to improve quality assurance and verify the reliability of RapidArc.Methods Referring to the PicketFenceStatic_M120.dcm and PicketFenceRA_Ml20.dcm files,the Tilt tests with different adjacent leaf speed were designed and setup errors of MLC were obtained by analyzing electronic portal imaging device images.Results In the Tilt tests,the setup errors gradually increased from gapl 1 to gapS0 in both static gantry mode and RapidArc mode.With a gantry angle of 270°,gap41 had the maximum setup error of-0.55 mm.In the RapidArc mode,gap46 had the maximum setup error of-0.67 mm.The deviation of gap width was no greater than 15％ in any mode.There was no significant difference in deviation pattern of gap width between four modes with different gantry angles.The same gaps in different stripes showed a consistent trend in gap width.The RapidArc mode had a larger variation in percentage deviation of gap width than the static gantry mode.Conclusions The setup error increases with the increase in the speed of MLC leaf.The variation in the leaf speed has no significant impact on the gap width.There is no correlation between the leaf speed and the deviation of gap width.Four different gantry angles give similar deviation patterns of gap width,suggesting that the deviation of gap width is related to the leaf rather than the gantry angle.The RapidArc mode has a greater impact on the gap width than the fixed gantry mode.

AIM: To study the effects of Yangyu Tuji (YYTJ) on delayed healing wound of diabetic rats caused by streptozotocin (STZ). METHODS: SD male rats were randomly divided into control group (control), model group (model); and 3 different dose groups of YYTJ. 55 mg/kg STZ were given by intraperitoneal injection except for control group. After 30 days, a round skin of 1.6 cm diametre was excised on all dorsal back of rats. The healing time and healing rate were observed according to re-epithelization. The content of collagenⅠ and Ⅲ was observed by Picric acid-Sirius red staining , Matrix metalloproteinase-1, 13 (MMP-1, -13), tissue inhibitor of metalloproteinases-1 (TIMP-1) by immuno-histochemistry assay. All data were analyzed by IPP software. RESULTS: The healing time in each group treated with YYTJ was shorter than that in model group (P

Keshan disease was an endemic cardiomyopathy in China. The very low selenium intake of local people was considered to be an important causal factor. The main pathological characteristics of this disease was multifo-cal necrosis and fibrous replacement of myocardium that was scattered throughout the wall of all chambers.Two patterns of myocardial necrosis, myofibrillar pattern and mitochondrial pattern were distinguished in electron microscopy. The myofibrillar pattern was characterized by myofibril segmentation. It agreed well with the contraction band necrosis described in light microscopy. It was mainly seen in acute Keshan heart and might be related to circulatory disorders. Mitochondrial pattern was identical with myocytolysis of conventional pathology. It represented the typical lesion of Keshan disease.Mitochondria showed early and conspicuous changes in involved myo-cytes. Myofibrillar damage seemed to be secondary to the mitochondrial injury in the development of myocytolysis.Histochemical studies revealed that the acid phosphatase activity was obviously increased in muscle fibers surrounding the necrotic foci, and the succinic dehydrogenase activity was greatly reduced in damaged myocardio-cytes.

The 81st annual scientific meeting of the American Diabetes Association (ADA) was held online from June 25 to 29, 2021. The conference encompassed following theme areas: Acute and chronic complications of diabetes, behavioral medicine, clinical nutrition, education and exercise, clinical diabetes/therapeutics, epidemiology/genetics, immunology/transplantation, insulin action/molecular metabolism, integrated physiology/obesity and islet biology/insulin secretions, which covers both clinical and basic aspects of diabetes mellitus and other metabolic diseases. Here is the summary of the main points of academic progress in diabetes and other metabolic diseases.

Objective To explore the effect of Shuanglu Tongnao Formula on neuronal ferroptosis in ischemic stroke rats and its regulatory mechanism on the silent information regulator 2 homolog 1(SIRT1)/nuclear factor erythroid 2-related fac-tor 2(Nrf2)/glutathione peroxidase 4(GPx4)signaling pathways.Methods Twenty rats were selected as sham operation group by the random number table method,and the remaining seventy rats were made ischemic stroke rat models by the middle cerebral artery occlusion method.The rats that had been successfully modeled were randomly divided into the model control group,Shuanglu Tongnao formula group,Shuanglu Tongnao formula+SIRT1 inhibitor group(Shuanglu Tongnao formula+EX527 group),with 20 rats in each group.After 14 days,the rats were scored for neurological injury;TTC staining was applied to detect the area of cerebral infarction in rats;HE staining was applied to detect pathological changes in rat brain tissue;Nissl staining was applied to detect the number of neurons in rat brain tissue;the kit was applied to detect the levels of ferri ion(Fe2+),superoxide dismutase(SOD),glutathione(GSH),and malonaldehyde(MDA)in rat brain tissue;immunohistochemistry was applied to de-tect the positive expression of acyl-CoA synthetase long-chain family member 4(ACSL4),transferrin receptor(TFR),and ferritin heavy polypeptide 1(FTH1)proteins in rat brain tissue;Western blotting method was applied to detect the expression of SIRT1,Nrf2,GPx4,and cystine/glutamate antiporter solute carrier family 7 member 11(SLC7A11)proteins in rat brain tissue.Results Compared with the sham operation group,the neurological deficit score,cerebral infarction area,the contents of Fe2+and MDA,and the protein expressions of ACSL4 and TFR in model control group were increased(P<0.05);the number of neurons,the con-tents of SOD and GSH,the protein expression of FTH1,SIRT1,Nrf2,GPx4,and SLC7A11 were all reduced(P<0.05).Compared with the model control group,the neurological deficit score,cerebral infarction area,the contents of Fe2+and MDA,and the protein expression of ACSL4 and TFR in the Shuanglu Tongnao formula group were reduced(P<0.05),and the number of neurons,the contents of SOD and GSH,the protein expressions of FTH1,SIRT1,Nrf2,GPx4,and SLC7A11 are all increased(P<0.05).The results of the SIRT1 inhibitor supplementation experiment showed that the SIRT1 inhibitor reversed the inhibitory effect of Shuan-glu Tongnao formula on neuronal ferroptosis,while also inhibited the expression of Nrf2 and GPx4(P<0.05).Conclusion The Shuanglu Tongnao formula may inhibit neuronal ferroptosis in ischemic stroke rats by activating the SIRT1/Nrf2/GPx4 signa-ling pathway.