Structure and electrochemical performance of Cu singly doped and Cu/Al co-doped nano-nickel hydroxide

Nanometer Cu singly doped and Cu/Al co-doped nickel hydroxides were synthesized by ultrasonic-assisted precipitation method. Their crystal structure, particle size, morphology, tap density and electrochemical performance were investigated. The results show that the samples have a-phase structure with narrow particle size distribution. Cu singly doped nano-Ni（OH）2 contains irregular particles, while Cu/Al co-doped nano-Ni（OH）2 displays a quasi-spherical shape and has a relatively higher tap density. Composite electrodes were prepared by mixing 8% （mass fraction） nanometer samples with commercial micro-size spherical nickel. The charge/discharge test and cyclic voltammetry results indicate that the electrochemical performance of Cu/Al co-doped nano-Ni（OH）2 is better than that of Cu singly doped nano-Ni（OH）2, the former＇s discharge capacity reaches 330 mA.h/g at 0.2C, 12 mA.h/g and 91 mA.h/g larger than that of Cu singly doped sample and pure spherical nickel electrode, respectively. Moreover, the proton diffusion coefficient of Cu/Al co-doped sample is 52.3% larger than that of Cu singly doped sample.

Usefulness of contrast-enhanced ultrasonography in determining treatment efficacy and outcome after pancreatic cancer chemotherapy

AIM:To investigate if contrast-enhanced ultrasonography(CE-US) is useful for determining treatment efficacy and outcome in the early stages of pancreatic cancer chemotherapy by assessing changes in intratumor hemodynamics using CE-US with a contrast agent.METHODS:The subjects were 34 patients with unresectable advanced pancreatic cancer treated by chemotherapy.CE-US was assessed after every treatment(course) completion under the same conditions,and patients were divided into two groups according to the intratumor enhancement pattern:Vascular rich(R) group and vascular poor(P) group.RESULTS:After the second course of treatment,R group in intratumor hemodynamics had 18 patients,and P group had 16 patients.The reduction rates of serum CA19-9 level after chemotherapy which decreased to half or less of the baseline level were 2/15(0.1%) in P group,but 11/16(69%) in R group(P = 0.006).When the mean number of courses of chemotherapy and outcome were compared,P group had a mean number of courses of 4.9(R group,10.2) and mean survival time(MST) of 246 d(R group,402 d),showing that outcome was significantly better in R group(P=0.006).CONCLUSION:CE-US revealed that the change in intratumor blood flow correlated with both serum CA19-9 level and outcome.Patients with serum CA19-9 that decreased to less than half the baseline level,and patients with an abundant intratumor blood flow,had a significantly better outcome.Thus,CE-US is potentially useful for evaluating treatment efficacy and outcome in the early stages of pancreatic cancer chemotherapy.

脱脂椰蓉可溶性膳食纤维的抗氧化活性研究

以脱脂椰蓉为原料,采用超声波辅助碱法提取可溶性膳食纤维,研究料液比、碱液浓度、超声时间、超声温度对提取率的影响,优化工艺条件并对提取的椰蓉可溶性膳食纤维进行抗氧化活性研究。结果表明,超声波辅助碱法提取脱脂椰蓉可溶性膳食纤维的最佳工艺参数是:料液比1:30、碱液浓度7%、超声时间30 min、超声温度40℃,椰蓉可溶性膳食纤维提取率为12.23%。抗氧化性试验结果表明,椰蓉可溶性膳食纤维具有一定的抗氧化和还原力,对DPPH·和·OH清除率分别可达68.4%和61.2%。

Study of lanthanide doped zinc oxide nanoparticles synthesized via a sonochemical method

In this work, lanthanide doped zinc oxide nanoparticles synthesized in room-temperature ionic liquid via a sonochemical method have been studied. Firstly, the cavitation bubble temperatures in 1-butyl-3-methylimidazolium hexafluorophosphate (ImPF6) have been estimated by the methyl radical recombination method. The temperatures measured in ImPF6 are in the range of 3000-4000 K. Secondly, a facile method has been proposed to prepare lanthanide (Ⅲ) doped zinc oxide nanoparticles in ImPF6 via an ultrasonic irradiation. The nanomaterials are studied by transmission electron microscopy, X-ray diffraction, photoacoustic and luminescence techniques. The results show that the relaxation processes of the samples depend strongly on the lanthanide doping. Moreover, a mechanism is proposed to interpret the formation of lanthanide (Ⅲ) doped zinc oxide nanoparticles in the ImPF6 upon ultrasonic irradiation.

Crystal formation and growth mechanism of inorganic nanomaterials in sonochemical syntheses

A clear understanding of the nucleation, growth, coarsening, the preparation of highly controlled nanostructures. Among and aggregation processes of nanomaterials is necessary to enable wet chemical synthetic methods, ultrasound-assisted preparation has become an important tool in material science. The formation and crystal growth mechanism under ultrasound is special compared with other wet chemical synthetic routes. In this review, we discussed the chemical and physical effect of ultrasound and summarized the ultrasonic effect on crystallization. The sonolysis of water and the cavitation-induced microjet impact and shockwave are the two key factors in the sonochemieal formation of inorganic nanomaterials. The ultrasonic-assisted Ostwald ripening and oriented attachment processes have been reviewed for the possible crystal growth mechanisms in the fabrication of inorganic nanostructures.