Optimization of Porous Insert Configuration in a Central Receiver Tube for Heat Transfer Enhancement

AbstractIn this paper, the heat transfer enhancement for convection heat transfer of turbulent flow in a central receiver tube filled with porous medium under non-uniform circumferential heat flux was numerically investigated. The effects of some parameters of porous medium (layout, thermal conductivity and porosity) and the Reynolds number (Re) on the thermal and thermo-hydraulic performance were discussed. The results showed that the enhanced receiver tube (ERT) with down-filling porous inserts and in-filling porous inserts have good thermal performance when the ratio of thermal conductivity of porous medium to working fluid (λs/λf) is less than 1,000. The ERT with out-filling porous inserts and up-filling porous inserts have good thermo-hydraulic performance when λs/λf >100. The porosity (ɛ) and Re also affect the thermal and thermo-hydraulic performance, the Nusselt number (Nu) and performance evaluation criteria (PEC) of heat transfer enhancement under constant pumping power of most kinds of ERTs decrease with the increase of ɛ, but the PEC of the ERT with in-filling porous inserts increases with the increase of ɛ. The Nu of all kinds of ERTs increases with the increase of Re, but the PEC decreases with the increase of Re

Achievement of interventions on HIV infection prevention among migrants in China: A meta-analysis

In China, migrants with acquired immunodeficiency syndrome (AIDS) have become a serious problem in the field of AIDS prevention. This study aimed to evaluate the efficacy of interventions for human immunodeficiency virus (HIV) infection prevention for migrants in China and to identify factors associated with intervention efficacy. A computerized literature search of the Chinese National Knowledge Infrastructure, Wan Fang, and PubMed databases was conducted to collect related articles published in China. Only self-control intervention studies or studies containing sections regarding self-control interventions wherein the method of intervention was health education were included. Rev Manager 5.3 software was used to analyze the intervention effects in terms of knowledge, attitude, and behavior indexes. Relative to pre-intervention, the HIV interventions showed statistically significant efficacy in terms of sexual transmission of HIV, condom use for HIV prevention, change in attitude towards HIV/AIDS patients, incidence of commercial sex behavior, and recent condoms use during sex (P < .01). Moreover, the baseline rate of migrants, intervention time, peer education, region, and education background were factors influencing the efficacy of the intervention. Significant improvement in terms of knowledge of sexual transmission of HIV and attitudes and behaviors among migrants was observed; however, based on the findings of previous studies, the interventions should be customized for different people from different districts in China. Further research is needed to evaluate subgroups of migrants in China according to their baseline characteristics.Keywords: migrants, AIDS/HIV, intervention, meta-analysis, precision interventio

Clinical efficacy and safety of edaravone therapy in acute cerebral haemorrhage

Purpose: To evaluate the clinical efficacy and safety of edaravone in the treatment of acute cerebral haemorrhage (ACH).Methods: This study recruited 120 patients who developed ACH. The patients were divided into control and treatment groups with 60 patients per group. The control group underwent conventional treatment and the treatment group also received intravenous edaravone. The volumes of cerebral edema and cerebral hematoma, high-sensitivity C-reactive protein (hs-CRP) and interleukin-6 (IL-6) levels, and Chinese Stroke Scale (CSS) score before and after treatment were compared between the two groups.Results: The respective cerebral edema volumes of the control and treatment groups decreased from 20.99 ± 12.09 and 21.80 ± 12.01 mL on day 0 to 11.23 ± 6.34 and 12.11 ± 5.98 mL at day 7 and 4.69 ± 4.03 and 4.64 ± 3.9 mL on day 14 (P < 0.05). The respective cerebral hematoma volumes of the control and treatment groups decreased from 18.98 ± 12.04 and 18.97 ± 12.07 mL on day 0 to 12.34 ± 6.57 and 11.89 ± 4.01 mL at day 7 and 9.49 ± 3.95 and 9.52 ± 3.96 mL on day 14. Compared with pretreatment, hs-CRP and IL-6 levels and CSS score of the two groups decreased significantly following treatment (p < 0.05); the differences in the cerebral edema and hematoma volumes of the two groups on days 7 and 14 were not significant (p > 0.05). The hs-CRP and IL-6 levels and CSS scores of the treatment group decreased appreciably (p < 0.05), while the incidence of adverse reactions in the treatment and control groups was 16.67 and 13.33 %, respectively, but the difference was not significant (p > 0.05).Conclusion: Edaravone shows remarkable clinical efficacy and safety with no obvious adverse reactions in the treatment of ACH. Therefore, its use is recommended.Keywords: Cerebral haemorrhage, Edaravone, Cerebral edema, C-reactive protein, Interleukin-6, Chinese Stroke Scal

Isopropyl 4-nitro­benzoate

In the mol­ecule of the title compound, C10H11NO4, the nitro group is approximately coplanar with the benzene ring [dihedral angle = 4.57 (10)°], while the carboxyl­ate group is slightly twisted, making an angle of 12.16 (8)°. In the crystal, weak inter­molecular C—H⋯O hydrogen bonding and π–π stacking inter­actions [centroid–centroid distances = 3.670 (2) and 3.665 (2) Å] are observed

Effects of Triptergium Glycosides on Expressions of MCP- 1 and CTGF in Rats with Early Diabetic Nephropathy

Purpose: To investigate the effects of triptergium glycosides (TG) on expressions of monocyte chemoattractant protein-1 (MCP-1) and connective tissue growth factor (CTGF) in early diabetic nephropathy (DN) in rats, and explore its mechanism of renal protection.Methods: Thirty-two rats were divided into 4 groups: normal control (NC), DN, and DN-treated with TG (5 and 10 mg/kg/d) groups. After 8 weeks, body weight, blood glucose (BG), albumin (ALB), blood urea nitrogen (BUN), creatinine (SCr) and 24 h urinary total protein (UTP) of rats were determined. Additionally, expressions of CTGF, MCP-1 and ED-1 were detected by immunohistochemistry assay, while mRNA and protein expressions of CTGF and MCP-1 in kidney tissues were evaluated using reverse transcription-polymerase chain reaction (RT-PCR) and western blot technique.Results: BG, ALB, SCr, BUN and UTP in DN group were significantly increased (p < 0.01), compared with NC group. Compared with DN group, ALB (28.90 and 31.49 vs 23.13 g/L) and UTP (21.87 and 18.91 vs 37.19 mg/24 h) were significantly changed in TG groups (p < 0.05). ED-1 positive cells were significantly increased in DN group (p < 0.01), compared with NC group, whereas treatment with TG significantly reversed the increase (1.67 and 1.41 vs 2.73 in glomeruli, 9.86 and 9.49 VS 13.18 in glomerular interstitial, p < 0.01). Proteins and mRNA expressions of CTGF and MCP-1 significantly increased (p < 0.01) in DN group, compared with NC group, while their expressions in TG groups were reversed.Conclusion: TG ameliorates renal injury in diabetic rats via decreasing MCP-1 and CTGF expressions and reducing macrophage activation.Keywords: Diabetic nephropathy, Triptergium glycosides, Connective tissue growth factor, Monocyte chemoattractant protein-

Effect of rosiglitazone on rabbit model of myocardial ischemia-reperfusion injury

AbstractObjectiveTo explore mechanism and protective effect of rosiglitazone on myocardial ischemia reperfusion (I/R) injury.MethodsA total of 48 male Japanese white big-ear rabbits were randomly divided into control group (A), I/R group (B), low dose of rosiglitazone group (C), high dose of rosiglitazone group (D). Plasma concentration of and also reduced the concentration of plasma serum creatine kinase (CK), CK-MB, high-sensitivity C-reactive protein (hsCRP), ultra-superoxide dismutase (SOD), malondialdehyde (MDA), lactic acid glutathione skin peroxidase (GSH-PX), nitric oxide (NO) and endothelin (ET) were measured 1 h later after I/R. Twenty-four hours after I/R the hearts were harvested for pathological and ultrastructural analysis. Area of myocardial infarction were tested.ResultsPlasma concentration of CK, CK-MB, hsCRP, NO, MDA and ET were decreased in C, D group compared with group B. Plasma concentration of T-SOD and GSH-Px were increased significantly in C, D group compared with group B. Compared with group B, pathological and ultrastructural changes in C and D group were slightly. There was significant difference in myocardial infarction area between group C, D and group B (P<0.05). Myocardial infarction area and arrhythmia rate were lower in group C, D compare with group B.ConclusionsRosiglitazone may protect myocardium from I/R injury by enhancing T-SOD and GSH-Px concentration, inhibit inflammatory reaction, and improve endothelial function

2,4-Dichloro-6-[2-meth­oxy-4-(prop-2-en-1-yl)phen­oxy]-1,3,5-triazine

The title compound, C13H11Cl2N3O2, was obtained by the reaction of eugenol and cyanuric chloride. The dihedral angle between the benzene and triazine rings is 87.56 (4)°. Two C atoms of the allyl group are disordered over two sites in a 0.72 (2):0.28 (2) ratio