1.
Serum copper and zinc levels in breast cancer: A meta-analysis.
Feng, Y, Zeng, JW, Ma, Q, Zhang, S, Tang, J, Feng, JF
Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS). 2020;:126629
Abstract
BACKGROUND More and more studies have investigated the relationship between serum copper (Cu) and/or zinc (Zn) levels and breast cancer (BC). However, the results are inconsistent. It is unclear whether the serum Cu to Zn ratio (Cu/Zn) is associated with BC risk. Therefore, we evaluated serum Cu and Zn concentrations, and Cu/Zn in BC through meta-analysis. MATERIALS AND METHODS Studies reporting serum Cu and/or Zn concentrations in BC patients and controls from 1991 to 2020 were identified from PubMed, CNKI, and Wanfang databases online. Based on a random effects model, summary standard mean differences (SMDs) and the corresponding 95 % confidence intervals (95 % CIs) were applied to compare the serum levels of Cu, Zn and Cu/Zn between BC patients and controls. RESULTS Thirty-six eligible studies involving 5747 female subjects were included. The present study illustrated that the BC patients had significantly higher serum Cu levels than healthy controls (HC) (SMD (95 % CI): 1.99(1.48, 2.49)) and patients with benign breast diseases (BD) (SMD (95 % CI): 0.99(0.38, 1.61)). However, Zn concentrations were statistically decreased in BC patients than HC (SMD (95 % CI): -1.20(-1.74, -0.66)) and BD (SMD (95 % CI): -1.13 (-1.73, -0.54)). Cu/Zn concentrations were remarkably increased in BC patients than HC (SMD (95 % CI): 2.75(1.79, 3.60)) and BD (SMD (95 % CI): 2.98(1.91, 4.05)) in some studies. CONCLUSION The results show that elevated serum levels of Cu and Cu/Zn, as well as decreased Zn might be associated with increased risk of breast cancer. These three parameters have the potential to distinguish breast cancer from benign breast diseases.
2.
Improvement of lactic acid production from cellulose with the addition of Zn/Ni/C under alkaline hydrothermal conditions.
Zhang, S, Jin, F, Hu, J, Huo, Z
Bioresource technology. 2011;(2):1998-2003
Abstract
The effect of Zn, Ni and activated carbon on the yield of lactic acid from cellulose was investigated to improve the lactic acid yield under alkaline hydrothermal conditions. The results showed that the lactic acid yield increased greatly in the presence of Zn, Ni and activated carbon. Central composite response surface method (RSM) design experimentation was used to find the optimal concentrations of Zn, Ni, activated carbon and NaOH, which indicated that 0.02 g Zn, 0.03 g Ni, 0.07 g activated carbon and 2.5 mol/L NaOH were the optimal concentrations. Under this condition, the highest lactic acid yield was 42%, which was much higher than previous results using only NaOH (15%). The confirmatory experiments on lactic acid yield proved that the proposed model of lactic acid yield can accurately predict the lactic acid yield from cellulose.