Objective To study the flow fields of electrolysis oxygen generation with micro-flow-channels of small square cylinders and the key structure factors impacting on the uniform distribution of the water flow in the micro-flow-channels.Methods The low Renault k-? model was used to represent the characteristics of the flow field in the micro-flow-channels.And the simulation results of the flow fields by CFD were calibrated by comparing with that of the particle image velocimetry(PIV) experiments,which showed that the low Renault k-? model was suitable to describe the flow field of the micro-flow-channels.Results The flow fields of variable flow were obtained.Conclusion The flow fields of variable flow rates distribute non-uniformly.The velocity magnitude is 10-3m/s,and the inlet structure of the electrolysis oxygen generation is a key factor impacting on the uniform distribution of the water flow.

Objective To study a technology for separating water from gas under microgravity in long-term manned space flight.Methods Several kinds of mixture of water and oxygen were separated by a new water/gas separating matrix and the action of gravity on the process was studied.Results The water/gas separator worked well in the range of gas flow below 2 500 mL/min and water flow below 4～6 L/h.A mixture of gas and water was separated into gas containing no water containing less than 1% gas.The phenomenon of a little oxygen existing in the water flow was explained.It was also found that gravity has nothing to do with the separation.Conclusion Hydrophilic porous membrane can be used to separate water from gas,and further works were continue needed to study the process and to resolve a few problems about water/gas separation under microgravity.

Objective To prepare the Pt/CeO2/GAC catalyst used to catalyze oxidation of condensate wastewater and to investigate whether the doping of Ce can increase catalytic activity for oxidizing condensate wastewater.Methods Impregnation glycol reduction method was adopted to prepare Pt/CeO2/GAC catalyst,and it was characterized by BET,XPS and XRD.The catalytic activity was determined by batch experiment.Results The experimental results revealed that more than 93.4% of ethanol in the condensate wastewater was oxidized to aldehyde and acetic acid with 13.33 g?L-1 Pt/CeO2/GAC catalyst dose,for 2 h reaction time,at 40 ℃ and normal pressure.In contrast,the oxidation efficiency was only 85.0% with Pt/GAC catalyst without doping Ce in the same reaction condition.Conclusion It is proven that the doping of Ce in Pt/GAC improves the catalytic activity.The characterization of Pt/CeO2/GAC catalyst shows that Ce is presented as Ce4+ that not only increases the content of chemisorbed oxygen on the surface of the catalyst,but also increases the content of Pt greatly.

Objective This study was designed to explore the effect of hyperglycemia on the expression of Toll-like receptor 4 (TLR4 ) in renal tubular epithelial cells and its significance in diabetic nephropathy. Methods In vitro cultured renal tubular epithelial cells ( NRK-52E) were divided into LG group (cultured in 5mmol / L glucose DMEM) and HC group (cultured in 25mmol / L glucose DMEM). Cells were harvested at different time points. Immunohistochemistry, Rt-PCR, Western Blot were used to detect TLR4 protein and mRNA expression, and the levels of IL-6 and TNF-α from the cell culture supernatant were determined by EL1SA assay. Results After 6 hours, there was increased expression TLR4 mRNA in HC group, which appeared to be maintained for 24 hours and began to decrease after 48 hours ( P < 0.05). TLR4 protein expression increased in HC group after 24 hours, and increased even further after 48 hours. Compared with LG groups, the difference had statistical significance ( P <0.05). In HG group, IL-6 and TNF-α expression in the supernatant from the NRK-52E culture were significantly increased ( P < 0.05) , and the expression of IL-6 and TNF-α was positive correlated with the expression of TLR4 protein ( r =0.799,0.820). Conclusion High glucose triggers an increase in expression of TLR4 in NRK-52E cells, itself leading to an increase in expression of inflammatory factors such as TNF-α and IL-6. In this way, TLR4 participates in the progress of diabetic nephropathy.

Objective To explore the effect of aldosterone on renal epithelialmesenchymal transition in streptozocin(STZ)-induced diabetic nephropathy rats. Methods Wistar rats were intraperitoneally injected with STZ(60 mg/kg)for the preparation of diabetic model.After 4 weeks,the rats with urinary protein＞30 mg/d were regarded as successful diabetic nephropathy(n=16),and were randomly divided into diabetic nephropathy(DN group,n=8)and spironolactone group(SP group,n=8).Then eight healthy rats were selected randomly as control group(N group,n=8).SP group rats were treated with spironolactone 40 mg·kg-1·d-1,and N group and DN group rats were given equal water.After 8 weeks,rats were sacrificed to collect urine,blood plasma,kidney tissue for detection of 24 h urinary protein,creatinine and renal pathological changes.Aldosterone concentration in plasma and kidney tissue was detected by mdioimmunoassay;E-cadherin,α-SMA protein expression by immunohistochemistry,Western blotting; E-cadherin,α-SMA mRNA expression by RT-PCR. Results Compared with N group,serum creatinine, urinary protein excretion in the DN rats were significantly higher (P＜0.01,respectively), E-cadhefin protein and mRNA were significantly reduced (P＜0.01, respectively),α-SMA protein and mRNA expression was up-regulated (P＜0.01, respectively). Aldosterone level of kidney tissue in DN rats was increased obviously [(24.71±5.30) ng/g vs (16.38±2.85) ng/g, P＜0.01], which was positively correlated with urinary protein excretion, serum creatinine and α-SMA protein (r=0.737, 0.574, 0.688, P＜0.01, respectively), and negatively correlated with E-cadherin protein (r=-0.659, P＜0.O1). While no significant difference was found in serum aldosterone among three groups. Compared with DN rats, urinary protein excretion, serum creatinine were reduced (P＜0.01, respectively), E-cadherin protein and mRNA were increased (P＜0.01, respectively), α-SMA protein and mRNA expression were decreased (P ＜0.01, respectively) in SP group rats.Conclusions Local aldosterone involves in renal epithelial-mesenchymal transition in diabetic nephropathy rat. Spironolactone can block the effect of aldosterone and play a role in renal protection.

Objective To determine the effect of aldosterone and its antagonist, spironolactone on epithelial-mesenchymal transition (EMT) of normal rat kidney epithelial cells (NRK-52E) in a high glucose milieu,and to explore the mechanism of renoprotection in diabetic nephropathy (DN ) in rats involving aldosterone and spironolacton. Methods NRK-52E cells were simultaneously cultured in the serum-free Dulbecco's modification of Eagle's medium Dulbecco (DMEM) for 12 hours. Then the low glucose (LG) group was cultured in LG (1000 mg/L) DMEM:The high glucose (HG) group was cultured in high glucose (4 500 mg/L) DMEM. The aldosterone (Aldo) groups were cultured in high glucose DMEM with the addition of 10,50 and 100 nmol/L aldosterone respectively. The SP group was cultured in high glucose (4 500 mg/L) DMEM plus 10~(-7)mol/L spironolactone. Immunohistochemistry, RT-PCR and Western blot were used to detect E-cadherin and α smooth muscle actin(α-SMA) mRNA expression. Results RT-PCR showed that compared with the LG Group, E-cadherin mRNA expression in the HG group was significantly lower, and α-SMA mRNA expression was significantly increased(P＜0.05). E-cadherin mRNA expression in the 50 nmol/L Aldo group and 100 nmol/L Aldo group was significantly lower than that in the HG group, while the expression of α-SMA mRNA was significantly increased in the HG group(P＜0.05), with a dose-dependent relationship with aldosterone(r=-0.70,P＜0.05;r=0.67, P＜0.05). E-cadherin mRNA in the SP group was significantly higher,while α-SMA mRNA expression was lower than that in the HG group(P＜0.01). Immunohistochemistry and Western blot showed that compared with the LG group, E-cadherin protein expression was significantly reduced, and α-SMA expression was significantly increased in the HG group(P＜0.01). In the 10 nmol/L Aldo, 50 nmol/L Aldo, and the 100 nmol/L Aldo groups, E-cadherin protein expression was significantly lower, and α-SMA protein expression was significantly higher than that in the HG group(P＜0.05), with a dose-dependent relationship with aldosterone(r=-0.83,P＜0.05;r=0.81, P＜0.05). In the SP group, E-cadherin protein expression was higher, and α-SMA protein level was lower than that in the HG group(P＜0.05). Conclusion Aldosterone can promote EMT of tubular epithelial cells in a high sugar milieu, leading to renal interstitial fibrosis in Diabetic nephropathy. Spironolactone can inhibit high glucose-induced renal tubular epithelial cells EMT, which may be an important mechanism for the inhibition of renal interstitial fibrosis.

Preliminary research and partial satellite carrying experiment were firstly carried out,so as to research the technique of environmental control and life support system(ECLSS)of Chinese manned spacecraft.Environmental control and life support sub-system of "Shenzhou" spacecraft were developed subsequently,and the technique of physical/chemical regenerative ECLSS and controlled ecological life support system(CELSS)were also researched gradually.This paper introduced the research and development of ECLSS of Chinese manned spacecraft,and discussed the technical character of ECLSS.

OBJECTIVE: To explore the relationship between protein kinase C (PKC) and matrix metalloproteinase (MMPs)/tissue inhibitor of metalloproteinase (TIMPs) in human mesangial cells under the high glucose medium, and to analyze the effect of PKC and MMPs/TIMPs in diabetes nephropathy (DN). METHODS: Normal human mesangial cells (NHMC) were divided into 4 groups: a control group(N, 5 mmol/L glucose), a high glucose group (H, 30 mmol/L glucose), a PKC inhibition group (P, 30 mmol/L glucose plus 10-5 mol/L chelerythrine chloride), and an mannitol group (M, 5 mmol/L glucose plus 25 mmol/L mannitol). Cell proliferation was measured by MTT at 24,48 or 72 hours. The activity of PKC was measured by ELISA and the mRNA and protein expressions of MMP2, 9 and TIMP1, 2 were examined by RT-PCR and Western blot. RESULTS: High glucose increased the activity of PKC as well as the expressions of mRNA and protein of MMP2, 9 and TIMP1, 2.The ratio of MMP-2/TIMP-2 and MMP-9/TIMP-1 was significantly decreased in the high glucose group compared with that of the control group (P<0.05). The mRNA and protein expressions of MMP2, 9 and TIMP1 were significantly increased in the PKC inhibition group compared with the control group (P<0.01). The ratio of MMP-2/TIMP-2 and MMP-9/TIMP-1 increased in the inhibition group compared with that of the high glucose group (P<0.05 or P<0.01). The activity of PKC was negatively correlated with the protein ratio of MMP-2/TIMP-2 and MMP-9/TIMP-1(rý-0.651,rý-0.702, both P<0.05). CONCLUSION High glucose can activate PKC in mesangial cells. The activity of PKC influences the expression of MMPs/TIMPs in the progressing of DN.
Cells, Cultured ; Glucose ; adverse effects ; pharmacology ; Humans ; Hyperglycemia ; metabolism ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Mesangial Cells ; metabolism ; Protein Kinase C ; metabolism ; Protein Kinase Inhibitors ; pharmacology ; RNA, Messenger ; metabolism ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism ; Tissue Inhibitor of Metalloproteinase-2 ; metabolism

OBJECTIVE: To examine the expressions of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in the kidney of rats with diabetic nephropathy before and after the treatment of Cordyceps sinensis, and to explore the mechanism of Cordyceps sinensis against hypoxia. METHODS: The diabetes model was produced by intraperitoneal injection of 60 mg/kg streptozotocin, then the rats whose 24 h urine protein level was above 30 mg/d were thought to have suffered diabetic nephropathy. Thirty rats were randomly divided into a diabetic nephropathy group (DN group, n=15) and a Cordyceps sinensis group (CS group, n=15), and another 15 normal rats served as a normal control group (NC group, n=15). The CS group were intragastrically administered Cordyceps sinensis extract liquid [5.0 g/(kg.d)], the other groups were intragastrically administered drinking water of equal volume. Five rats in each group were killed after 2, 4, and 6 weeks. The 24 h urine protein excretion, urine β-N-acetyl glucosaminidase (NAGase) and serum creatinine were measured; the renal pathological changes were evaluated by HE and Masson staining; the mRNA and protein expressions of HIF-1α and VEGF were dectected by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. RESULTS: Compared with the normal control group, the renal tubular vacuolar degeneration was obvious, and the glomerular mesangial matrix increased in the DN group. The 24 h urinary protein excretion, urine NAGase and serum creatinine also increased significantly (all P<0.05); the expressions of HIF-1α and VEGF in the renal tissue gradually increased with time, and the expression of HIF-1α was correlated with that of VEGF in the 2 groups (r=0.850, r=0.887, both P<0.05) . Compared with the DN group, the pathological changes were relieved, the 24 h urinary protein excretion, urine NAGase and serum creatinine level were decreased, and the expressions of HIF-1α and VEGF decreased in the CS group (all P<0.05), but they were still higher than those in the normal contral group (P<0.05). There was no significant difference in the mRNA and protein expression of HIF-1α between the 4th week and the 6th week after the treatment of CS (P>0.05). CONCLUSION The expressions of HIF-1α and VEGF increase in the kidney of rats with diabetic nephropathy, and the positive correlation suggests that there is chronic hypoxia in the renal tissue of diabetic nephropathy. Cordyceps sinensis may protect against chronic hypoxia injury in diabetic nephropathy by lowering the expressions of HIF-1α and VEGF.
Animals ; Cordyceps ; chemistry ; Diabetes Mellitus, Experimental ; complications ; metabolism ; Diabetic Nephropathies ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; metabolism ; Kidney ; metabolism ; Male ; Rats ; Rats, Wistar ; Vascular Endothelial Growth Factor A ; genetics ; metabolism