1.
The association of serum zinc and copper with hypertension: A meta-analysis.
Li, Z, Wang, W, Liu, H, Li, S, Zhang, D
Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS). 2019;:41-48
Abstract
OBJECTIVE The association of serum zinc (Zn), copper (Cu) with the risk of hypertension (HT) remains controversial. Therefore, we conducted a meta-analysis to explore the relationships. METHODS We searched relevant literatures on PubMed and Web of Science up to September 2018. Pooled standard mean difference (SMD) with corresponding 95% confidence interval (CI) was calculated by random effects model.I2 was used to evaluate heterogeneity among studies. RESULTS 25 articles of serum Zn and 22 articles of serum Cu were included in meta-analysis. HT patients had lower serum Zn [SMD (95%CI): -0.612(-0.951, -0.274), z = 3.54, Pfor z <0.001; I2 = 97.0%, PforI2 <0.001], whereas no significant difference of serum Cu was shown between HT patients and controls [SMD (95%CI): 0.153(-0.101, 0.407)]. Also, male HT patients had lower serum Zn [SMD (95%CI): -1.443(-2.868, -0.017), z = 1.98, Pfor z = 0.047; I2 = 98.8%, PforI2 <0.001]. In subgroup analysis, a lower serum Zn was observed in HT patients in studies conducted in Europe [-1.066(-1.759, -0.374)], in case-control studies [-0.718(-1.294, -0.142)], in matched case-control studies [-0.939(-1.646, -0.233)] and studies involving treated patients [-1.416(-2.195, -0.638)]. Meanwhile, a higher serum Cu was found in HT patients in studies conducted in Africa [1.96(1.402, 2.518)], and in matched case-control studies [0.655(0.204, 1.107)]. CONCLUSION The present meta-analysis indicates that serum Zn level in HT patients was significantly lower than that in controls, while no significantly different serum Cu level was found between HT patients and controls. Future studies are needed to confirm these results in future research.
2.
Adsorption of Cu(II) on oxidized multi-walled carbon nanotubes in the presence of hydroxylated and carboxylated fullerenes.
Wang, J, Li, Z, Li, S, Qi, W, Liu, P, Liu, F, Ye, Y, Wu, L, Wang, L, Wu, W
PloS one. 2013;(8):e72475
Abstract
The adsorption of Cu(II) on oxidized multi-walled carbon nanotubes (oMWCNTs) as a function of contact time, pH, ionic strength, temperature, and hydroxylated fullerene (C60(OH)n) and carboxylated fullerene (C60(C(COOH)2)n) were studied under ambient conditions using batch techniques. The results showed that the adsorption of Cu(II) had rapidly reached equilibrium and the kinetic process was well described by a pseudo-second-order rate model. Cu(II) adsorption on oMWCNTs was dependent on pH but independent of ionic strength. Compared with the Freundlich model, the Langmuir model was more suitable for analyzing the adsorption isotherms. The thermodynamic parameters calculated from temperature-dependent adsorption isotherms suggested that Cu(II) adsorption on oMWCNTs was spontaneous and endothermic. The effect of C60(OH)n on Cu(II) adsorption of oMWCNTs was not significant at low C60(OH)n concentration, whereas a negative effect was observed at higher concentration. The adsorption of Cu(II) on oMWCNTs was enhanced with increasing pH values at pH < 5, but decreased at pH ≥ 5. The presence of C60(C(COOH)2)n inhibited the adsorption of Cu(II) onto oMWCNTs at pH 4-6. The double sorption site model was applied to simulate the adsorption isotherms of Cu(II) in the presence of C60(OH)n and fitted the experimental data well.
3.
Using elevated carbon dioxide to enhance copper accumulation in Pteridium revolutum, a copper-tolerant plant, under experimental conditions.
Zheng, J, Wang, H, Li, Z, Tang, S, Chen, Z
International journal of phytoremediation. 2008;(2):159-70
Abstract
In our survey in the copper (Cu) mining area of China, a sun fern (Pteridium revolutum) was found to accumulate 30-567 mg Cu kg(-1) DW (33 samples) in its fronds with a large frond biomass. Cu translocation factors in the plants varied from 0.09 to 3.88. In a greenhouse pot experiment, the effect of an elevated CO2 concentration (700 microL L(-1)) on Cu accumulation in plants was studied using three fern species (P. revolutum, Pteridium aquilinum, and Pteris vittata) grown in the Cu-contaminated soil. P. revolutum showed a higher Cu tolerance but its Cu translocation factor was lower than 1. At the elevated CO2 concentration, frond biomass of all species was significantly increased, as was the total Cu content in the fronds of P. revolutum and P. aquilinum. Our study suggests that P. revolutum could serve as a good candidate for phytoextraction of Cu-contaminated soils and that doubling the ambient CO2 concentration will facilitate its use in phytoextraction.