Numerical simulation of the flow and erosion behavior of exhaust gas and particles in polysilicon reduction furnace.

In order to study the flow and erosion behavior of gas-solid exhaust in the polysilicon reduction furnace, the flow characteristics of exhaust gas and silicon particles were analyzed. The flow model and erosion model of exhaust gas and silicon particles were established based on the gas-solid flow theory and the erosion theory. The erosion and wear behavior of the gas-solid mixture in the flow passage pipeline were studied by numerical simulation. The results show that the wear and erosion from Nos. 1 to 8 regions at the bottom of the ring were caused by silicon particles colliding with high angle. The wear and erosion of 2 regions from Nos. 9 to 10 at the outside of the up azimuth on both sides of loop pipe outlets, 4 regions from Nos. 11 to 14 on the upper and lower wall of single furnace main channel were severely affected wear regions, which is caused by silicon particles with low angle and high velocity. Through comparative analysis, the erosion of upper wall of single furnace main channel is most serious. Increased gas velocity, particle concentration and particle size will exacerbate the erosion and wear rate of the pipeline in polysilicon reduction furnace, but the distribution and development of severe wear zone would not be affected significantly.

Effect of Shui Medicine Asarum insigne Polysaccharide on Glycolipid Metabolis,Renal Function and Oxi-dative Stress in Model Rats with Experimental Type 2 Diabetes / 中国药房

OBJECTIVE:To study the effect of Shui medicine Asarum insigne polysaccharide on glycolipid metabolism,renal function and oxidative stress in rats with experimental type 2 diabetes,and provide reference for its development and use. METH-ODS:60 SD rats were randomly divided into normal control group,model control group,positive control group (Irbesartan tab-lets,0.02 g/kg) and A. insigne polysaccharide low-dose,medium-dose,high-dose groups (calculated by crude drug as 2,4,8 g/kg),10 in each group. Except for normal control group,rats in other groups were intraperitoneally injected streptozotocin 75 mg/(kg·d)to induce model with diabetes. After modeling,rats in each administration group were intraperitoneally injected relevant medicines,and rats in normal control group and model control group were intragastrically administrated 5% carboxymet hylcellu-lose sodium solution,twice a day,for 42 d. After administration,UV spectrophotometer was used to detect the glycogen content in liver tissue. Automatic biochemical analyzer was used to detect 24 h urine output,24 h urinary protein content of rats,levels of tri-glyceride (TG),cholesterol (TC),low-density lipoprotein cholesterol (LDL-C),high-density lipoprotein cholesterol (HDL-C), creatinine (Cr),urea nitrogen (BUN) in serum,and levels of superoxide dismutase (SOD),glutathione peroxidase (GSH-Px), catalase(CAT),superoxide dismutase(ROS),malondialdehyde(MDA)in kidney tissue. RESULTS:Compared with normal con-trol group,glycogen content in liver tissue of rats in model control group was decreased(P<0.05);24 h urine output and 24 h uri-nary protein content were increased(P<0.05);levels of TG,TC,LDL-C in serum were increased(P<0.05),and HDL-C level was decreased (P<0.05);levels of SOD,CAT,GSH-Px in kidney tissue were decreased (P<0.05),and levels of ROS,MDA were increased(P<0.05). Compared with model group,except that there were no significant differences in the improvement of uri-nary protein content,HDL-C level in serum,24 h urine out-put in A. insigne polysaccharide low-dose group,above-men-tioned indexes in each administration group were obviously im-proved (P<0.05). CONCLUSIONS:A. insigne polysaccha-ride can regulate lipid metabolic disorders,and improve renal function and antioxidant capacity of rats.

Influence of Salvia miltiorrhizae on the mesenteric lymph node of rats with severe acute pancreatitis or obstructive jaundice.

OBJECTIVE: To observe the effect of salvia miltiorrhizae injection on inflammatory mediator levels and mesenteric lymph nodes in severe acute pancreatitis (SAP) and obstructive jaundice (OJ) rats and explore the protective mechanism of salvia miltiorrhizae on the lymph nodes of these rats. METHODS: A total of 288 rats were used in SAP-associated and OJ-associated experiments. The rats were randomly divided into sham-operated group, model control group, and treated group. At various time points after operation, the pathological changes in mesenteric lymph nodes of rats in each group were observed, respectively. RESULTS: The pathological severity scores in lymph nodes of SAP rats in treated group were significantly lower than those in model control group (P < .05) while the pathological changes in lymph nodes of OJ rats in treated group also showed varying degrees of mitigation. CONCLUSION: Salvia miltiorrhizae can exert protective effects on the lymph nodes of SAP or OJ rats via a mechanism that is associated with reducing the contents of inflammatory mediators in blood.

Analysis of the treatment response and prognosis of severe hand-foot-mouth disease / 中华传染病杂志

Objective To investigate the significance of early diagnosis and intervention in cases with severe hand-foot-mouth disease. Methods Nine severe cases were chosen from 220 hospitalized children with hand-foot-mouth disease for retrospective analysis, including onset, disease progression, the blood and cerebrospinal fluid tests, electroencephalogram data, patients' treatment responses and prognosis. Pearson X2 test and t test were utilized for statistical analysis. Results All cases showed nervous systems involved symptom, including meningeal irritation sign and (or) other pathological signs of nervous system (9 cases), drowsy (7 cases), trembling (6 cases), voiding dysfunction (3 cases), hypersensitivity(3 cases), autonomic nervous system disorders (2 cases), ataxia (1 case), left leg mild paralysis (1 case) and early stage of pulmonary edema (1 case). Early intervention, such as high dose gamma globulin, methylprednisolone, mannitol treatment restriction of fluid input, started before the development of heart and lung failure. No case died but one patient with encephalomyelitis showed hobbling left leg, which didn't recover until 6 weeks later. One case with brainstem encephalitis still showed abnormal electroencephalogram after 8 weeks follow-up but without clinical symptom. Conclusions Enterovirus 71 can cause severe hand-foot-mouth disease complicated by encephalitis, meningitis and pulmonary edema. Early active intervention before the development of neurogenic pulmonary edema can improve the prognosis and reduce the mortality.