负载过氧化铜的介孔二氧化硅纳米粒子协同化学动力学疗法和化疗联合治疗肿瘤

化学动力学治疗(CDT)是通过使用芬顿催化剂将细胞内过氧化氢(H_(2)O_(2))催化成羟基自由基(·OH)以杀死癌细胞的一种新型治疗方法。然而,内源性H_(2)O_(2)含量不足以及单一治疗的局限性限制了CDT的治疗效率。本工作报道了一种负载过氧化铜(CuO_(2))的介孔二氧化硅纳米颗粒(MSN)。其中,MSN内部负载化疗药物阿霉素(DOX),其表面负载催化剂CuO_(2)封堵孔道,避免药物提前早释。在肿瘤微环境(TME)刺激下,CuO_(2)分解产生外源性H_(2)O_(2)和类芬顿离子Cu~(2+),Cu^(2+)消耗细胞内谷胱甘肽(GSH)生成Cu^(+),Cu^(+)催化外源性H_(2)O_(2)生成高细胞毒性的·OH,协同化疗药物DOX实现CDT和化疗的联合治疗,提高抗肿瘤疗效。此外,体外细胞实验研究表明,该芬顿催化剂表现出良好的细胞相容性和优异的细胞毒性,为协同治疗肿瘤提供了一种新策略。

pH响应型过氧化铜修饰的介孔二氧化硅纳米催化剂用于肿瘤治疗

化疗是目前癌症治疗中最主要的治疗手段,然而化疗药物对肿瘤细胞无选择性,使得药物进入生物体后分布于各个组织器官,只有少量药物到达肿瘤组织,毒副作用大,治疗效果不尽人意。基于此,合成了一种负载过氧化铜(CuO2)的介孔二氧化硅(MSN)纳米催化剂,其内部装载化疗药物阿霉素(DOX),表面负载CuO2封堵孔道,避免药物提前释药,同时CuO2在胞内酸性条件下可通过类芬顿反应协同化疗杀死癌细胞,提高抗肿瘤疗效;实验数据显示,载药颗粒为146.2 nm的规则球形,比表面积458.07 m2/g,载药量为14.9%。本研究为肿瘤的联合治疗提供了一种新的策略。

过氧化铜和氧化铜的制备及其电化学还原CO_(2)性能研究——推荐一个综合研究型无机化学实验

铜基催化剂能高效地将CO_(2)深度电化学还原(CORR)为多碳烃类化合物,其催化性能与催化剂的结构有关。我们以大学无机化学实验“过氧化钙的制备及含量测定”为基础,设计了集合成、形貌结构表征和CORR的性能应用研究为一体的综合研究型实验。结果表明铜氧化物催化剂的形貌结构对CORR产物的选择性具有显著的差异。本综合研究型实验内容丰富,有助于提升学生化学专业核心素养,符合新时代化学学科的发展要求。

Bi系高温氧化物超导体CuO_2面内Cu-O键伸缩振动的分析

测试了一系列Ｂｉ系高温氧化物超导体的红外吸收谱，分析了Ｂｉ系超导样品ＣｕＯ２面内Ｃｕ—Ｏ键的伸缩振动与样品超导电性的联系。结果表明，ＣｕＯ２面内Ｃｕ—Ｏ伸缩振动吸收峰强度的变化与样品零电阻温度的变化一致，其原因与微观结构内部声子与载流子的相互作用密切相关。其次，根据分子振动理论，采用简化模型计算了Ｂｉ系超导体ＣｕＯ２面内Ｃｕ—Ｏ键的伸缩振动频率。

Effects of Waterborne Cu and Cd on Anti-oxidative Response, Lipid Peroxidation and Heavy Metals Accumulation in Abalone Haliotis discus hannai Ino

The aim of this study was to compare the effects of waterbome copper （Cu） and cadmium （Cd） on survival, anti-oxida- tive response, lipid peroxidation and metal accumulation in abalone Haliotis discus hannai. Experimental animals （initial weight： 7.49 g±0.01 g） were exposed to graded concentrations of waterborne Cu （0.02, 0.04, 0.06, 0.08 mg L-1） or Cd （0.025, 0.05, 0.25, 0.5 mgL-1） for 28 days, respectively. Activities of the anti-oxidative enzymes （catalase, CAT; superoxide dismutase, SOD; glutathione peroxidases, GPx; glutathione S-transferase, GST）, contents of the reduced glutathione （GSH） and malondiadehyde （MDA） in the hepatopancreas, and metal accumulation in hepatopancreas and muscles were analyzed after 0, 1, 3, 6, 10, 15, 21, 28 days of metal exposure, respectively. Results showed that 0.04 mg L-1, 0.06 mg L-1 and 0.08 mgL-1 Cu caused 100% death of abalone on the 21st, 10th and 6th day, respectively. However, no dead abalone was found during the 28-day waterborne Cd exposure at all experimental concentrations. Generally, activities of SOD and GST in hepatopancreas under all Cu concentrations followed a decrease trend as the exposure time prolonged. However, these activities were firstly increased and then decreased to the control level and increased again during Cd exposure. Activities of CAT in all Cu exposure treatments were higher than those in the control. These activities were firstly increased and then decreased to the control level and increased again during Cd exposure. Contents of MDA in hepatopancreas in all Cu treatments significantly increased first and then decreased to the control level. However, the MDA contents in hepatopan- creas were not significantly changed during the 28-day Cd exposure. The metals accumulation in both hepatopancreas and muscles of abalone significantly increased with the increase of waterborne metals concentration and exposure time. These results indicated that H. discus hannai has a positive anti-oxidative defense against Cu or Cd. In conclusion, anti-oxidative mechanism in abalone to resist waterborne Cu did not follow the same pattern as that for waterborne Cd.

Enhanced sulfidization flotation of cuprite by surface modification with hydrogen peroxide

Hydrogen peroxide was used as an oxidant to modify the cuprite surface and enhance its sulfidization.Surface-adsorption and infrared spectroscopy measurements indicated that the modification of the cuprite surface with hydrogen peroxide before sulfidization increased the adsorption capacity of xanthate.Zeta potential,scanning electron microscopy-energy dispersive X-ray spectroscopy,X-ray photoelectron spectroscopy,and time-of-flight secondary ion mass spectrometry results showed that the modification with hydrogen peroxide increased the contents of S^(2−)and Sn^(2−)species on the cuprite surface.Microflotation tests showed that the recovery of cuprite increased from 61.74%to 83.30%after the modification of the surface with hydrogen peroxide.These results confirm that the modification of the cuprite surface with hydrogen peroxide enhances the sulfidization of cuprite,which in turn improves its flotation.

Inhibitory Effect of Isorhapontigenin on Copper-Mediated Peroxidation of Human Low-Density Lipoprotein in vitro

Aim To study the effect of Isorhapontigenin (Iso) on copper-mediatedperoxidation of human low-density lipoprotein (LDL) and on the toxicity of oxidized LDL (ox-LDL) tomouse macrophages in vitro. Methods Human LDL from sera df normal lipidemic donors was separated bysequential ultracentrifugation. The separated human IDL 1 mg·mL^(-1) in phosphate buffer saline, pH7.4, was incubated with cupric sulfate (10 μmol·L^(-1) ) at 37℃ for 10 h in the presence orabsence of various concentrations of Iso. Malondialdehyde (MDA) formation, vitamin E consumption,electrophoretic mobility of LDL, mitochondria] membrane potential of mouse peritoneal macrophages,phagocytosis of neutral red, and release of nitric oxide (NO) from macrophages were determined byvarious methods. Results Iso 1 - 100 μmol·L^(-1) significantly inhibited the increase of MDAformation, vitamin E consumption and electrophoretic mobility of LDL induced by Cu^(2+) in aconcentration-dependent manner. The injury of the mitochondrial membrane potential of mouseperitoneal macrophages due to incubation with ox-LDL (0.1 mg·mL^(-1)) at 37℃ for 12 h was markedlyprotected by 10 μmol·L^(-1) Iso. After pretreat-ment of the macrophages with 10 μmol · L^(-1)of Iso and then exposure to ox-LDL for 4 h, the reduction of phagocytosis of neutral red and releaseof NO in response to lipopolysaccharide (IPS) stimulation were significantly prevented. ConclusionIso has protective action against Cu^(2+) - mediated LDL peroxidation and ox-LDL induced toxicity tomacrophages in vitro.

Low-temperature Catalytic Reduction of Nitrogen Monoxide with Carbon Monoxide on Copper Iron and Copper Cobalt Composite Oxides

Copper iron composite oxides （CuO/Fe2O3） and copper cobalt composite oxides （CuO/Co3O4） for the catalytic reduction of NO with CO at low temperature were prepared by co-precipitation. The catalytic activity and thermal stability of the catalysts were evaluated by a microreactor-GC system. The 100% conversion temperatures of NO are 80 ℃ for CuO/Fe2O3 and 90 ℃ for CuO/Co3O4. The catalysts possess high catalytic activity and favorable thermal stability for NO reduction with CO in a wide temperature range and long time range. A systematic study of the molar ratios of the reactants, the volume of NaOH, aging time, and calcination temperature/time was carried out to investigate the influence preparation conditions on the catalytic activity of the catalysts.

Theoretical perspective on mononuclear copper‐oxygen mediated C–H and O–H activations:A comparison between biological and synthetic systems

Dioxygen activations constitute one of core issues in copper-dependent metalloenzymes. Upon O_(2) activation, copper-dependent metalloenzymes such as particulate methane monooxygenases(pM MOs), lytic polysaccharide monooxygenases(LPMOs) and binuclear copper enzymes PHM and DβM, are able to perform various challenging C–H bond activations. Meanwhile, various copper-oxygen core containing complexes have been synthetized to mimic the active species of metalloenzymes. Dioxygen activation by mononuclear copper active site may generate various copper-oxygen intermediates, including Cu(Ⅱ)-superoxo, Cu(Ⅱ)-hydroperoxo, Cu(Ⅱ)-oxyl as well as the Cu(Ⅲ)-hydroxide species. Intriguingly, all these species have been invoked as the potential active intermediates for C–H/O–H activations in either biological or synthetic systems. Due to the poor understanding on reactivities of copper-oxygen complex, the nature of active species in both biological and synthetic systems are highly controversial. In this account, we will compare the reactivities of various mononuclear copper-oxygen species between biological systems and the synthetic systems. The present study is expected to provide the consistent understanding on reactivities of various copper-oxygen active species in both biological and synthetic systems.

Combined effects of water temperature and copper ion concentration on catalase activity in Crassostrea ariakensis

A central composite experimental design and response surface method were used to investigate the combined effects of water temperature(18–34℃) and copper ion concentration(0.1–1.5 mg/L) on the catalase(CAT) activity in the digestive gland of C rassostrea ariakensis. The results showed that the linear effects of temperature were significant(P <0.01), the quadratic effects of temperature were significant( P <0.05), the linear effects of copper ion concentration were not significant(P >0.05), and the quadratic effects of copper ion concentration were significant(P <0.05). Additionally, the synergistic effects of temperature and copper ion concentration were not significant(P >0.05), and the effect of temperature was greater than that of copper ion concentration. A model equation of CAT enzyme activity in the digestive gland of C. ariakensis toward the two factors of interest was established, with R 2, Adj. R 2 and Pred. R 2 values as high as 0.943 7, 0.887 3 and 0.838 5, respectively. These findings suggested that the goodness of fit to experimental data and predictive capability of the model were satisfactory, and could be practically applied for prediction under the conditions of the study. Overall, the results suggest that the simultaneous variation of temperature and copper ion concentration alters the activity of the antioxidant enzyme CAT by modulating active oxygen species metabolism, which may be utilized as a biomarker to detect the effects of copper pollution.

Cu_2O nanowires as anode materials for Li-ion rechargeable batteries

Li-ion batteries are a key technology for multiple clean energy applications.In this study,Cu2O nanowires were obtained by the reduction of cupric acetate with pyrrole.The resulting Cu2O nanowires exhibited excellent reversible capacities of 470mAh g-1 at rate of 1 C after 100 cycles.The results show that the Cu2O nanowires had more capacity than materials previously reported.No fading was observed over 100 cycles of charging and discharging.The compound metal Cu and incorporation of the conducting polymer polypyrrole(PPy)improved the conductivity of Cu2O and enhanced the stability of the electrode during cycling.The results from this study imply that Cu2O nanowires with high capacity and good cycle retention could be excellent candidates as anode materials for Li-ion rechargeable batteries.