Various composites of nominal composition (1-x)Ba0.95Ca0.05TiO3?+?xLi0.1Cu0.1Co0.1Zn0.6Fe2.1O4 have been prepared and studied thoroughly. X-ray diffraction and Rietveld refinement confirmed the presence of Ba0.95Ca0.05TiO3 and Li0.1Cu0.1Co0.1Zn0.6Fe2.1O4 phases in the composites. The microstructures have been investigated by field emission scanning electron microscopy. Temperature dependent dielectric constant shows two peaks, one is at 150 °C and another at 270 °C for x?=?0.10 composite which resembles the characteristic ferroelectric and ferromagnetic transition peaks. A gradual progression of ferro-para electric transition towards room temperature is observed with doping. The non-Debye type dipole relaxations have been found. The linearity in the log(σAC) vs. log(ω) plots indicate that conduction is due to small polaron hopping. The real part of initial permeability increases with growing ferrite concentration but the cut-off frequency decreases. The magnetic property is also enhanced with doping content. The typical ferroelectric hysteresis loops have also seen with the addition of Li0.1Cu0.1Co0.1Zn0.6Fe2.1O4 up to x?=?0.40. The impedance values are found to decreases in the Nyquist plots. The magnetoelectric voltage coefficient is obtained 287?×?103 V/mT for x?=?0.15 at room temprrature. We found both ferromagnetic and ferroelectric hysteresis loops at room temperature. So, it confirms that the composites exhibit room temperature multiferroicity. This type of composites offers variety of opportunity for multifunctional devices application like hetero-structured read / write memory devices, switching devices and magnetic field sensing devices.
Prostate cancer (PC) is the most common cancer in men and the second leading cause of cancer-related death worldwide. Many therapeutic advances over the last two decades have led to an improvement in the survival of patients with metastatic PC, yet the majority of these patients still succumb to their disease. Antiagiogenic therapies have shown substantial benefits for many types of cancer but only a marginal benefit for PC. Ongoing clinical trials investigate antiangiogenic monotherapies or combination therapies. Despite the important role of angiogenesis in PC, clinical trials in refractory castration-resistant PC (CRPC) have demonstrated increased toxicity with no clinical benefit. A better understanding of the mechanism of angiogenesis may help to understand the failure of trials, possibly leading to the development of new targeted anti-angiogenic therapies in PC. These could include the identification of specific subsets of patients who might benefit from these therapeutic strategies. This paper provides a comprehensive review of the pathways involved in the angiogenesis, the chemotherapeutic agents with antiangiogenic activity, the available studies on anti-angiogenic agents and the potential mechanisms of resistance. 相似文献
Rice husk (RH) is a very effective natural adsorbent for fast removal of heavy metal cations from water solutions. Application of RH for removal of some heavy metal ions, such as Ni, Zn, Mn, Co, Cu, Pb and Cd from water solutions has been studied and different maximum adsorption capacities and a variety of optimized conditions were reported in the literature. In this work, the efficiency of RH harvested from different climatic regions was studied. For this proposal, different RH samples were collected from three different climatic regions of Iran (nominated as RH1 to RH3); their removal efficiencies of heavy metal cations of Ni(2+), Cu(2+) and Cd(2+) were investigated and compared. The adsorption data at optimum conditions could be assessed well by both Langmuir and Freundlich models. Statistical analysis of the results of adsorption isotherms showed that different RH samples have different efficiencies in uptake of these heavy metal ions. The RH samples were characterized using Fourier transform infrared spectroscopy and Boehm titration, which indicated that amounts of functional groups differed between RHs that are grown in different climatic conditions. 相似文献
Based on results obtained utilizing combinatorial chemistry techniques to screen the thermoelectric power factor of materials in the system ZnxIny Ox+1.5y, several multiphase candidates were down-selected and investigated in terms of their thermoelectric response from room temperature to 1050°C. While the screening experiments suggested that peaks in the power factor occur at relatively high indium oxide content, only the thermoelectric properties of zinc-oxide-rich homologous layered phases in the system (In2O3)(ZnO)k have been well documented, since the phases where k < 3 cannot be easily formed. In the present study, indium-oxide-rich materials in the system In2O3–(In2O3)(ZnO)3 were fabricated and their figures of merit were determined. The results suggest that the indium-oxide-rich phases have improved figures of merit, especially at elevated temperatures, relative to the best performing k phases by combining the high power factor of In2O3 and the low thermal conductivity of (In2O3)(ZnO)k. 相似文献
Breeding crops for disease resistance is a sustainable approach to reduce yield losses. While significant research on the adoption and impacts of improved crop varieties exists, most studies have analyzed yield effects in general without distinguishing between different varietal traits and characteristics. Here, panel data from wheat farmers in Ethiopia were used to compare improved varieties that are resistant to stripe rust (caused by Puccinia striiformis f. sp. tritici) with improved susceptible and traditional susceptible varieties. Production function estimates suggest that improved resistant varieties raise effective yields by 8% in comparison to local susceptible varieties. The yield difference between improved resistant and improved susceptible varieties is positive but small because rust levels were not very high in the years under study. However, under drought and other abiotic stresses, improved varieties – with and without resistance to stripe rust – performed notably worse than local varieties. The worse performance under abiotic stress may explain why many farmers have recently switched back to growing traditional varieties. Sustainable adoption needs a combination of various traits in the same varieties, including high yield potential, grain quality, disease resistance and tolerance to drought and other production stresses. 相似文献
The 129 mouse is the most widely used strain in gene targeting experiments. However, numerous substrains exist with demonstrable physiological differences. In this study a set of simple sequence length polymorphisms (SSLPs) was used to determine the relatedness of selected 129 substrains. 129/SvJ was significantly different from the other 129 substrains and is more accurately classified as a recombinant congenic strain (129cX/Sv), being derived from 129/Sv and an unknown strain. This mixed genetic background could complicate gene targeting experiments by reducing homologous recombination efficiency when constructs and ES cells are not derived from the same 129 substrain. Additionally, discrepancies due to different genetic backgrounds may arise when comparing phenotypes of genes targeted in different 129-derived ES cell lines. 相似文献