Search

There is increasing concern about the adverse impact of exposure to microplastic, as an emerging pollutant, on wild organisms, and particularly on organisms co-exposed to microplastic and other environmental contaminants. It has been widely reported that the combination of microplastics and heavy metals showed obvious toxicity to organisms in terms their growth and development. The present study was performed to determine the impact of binary metal mixtures of cadmium (Cd) and polystyrene microplastic (PS-microplastic) on Tigriopus japonicus, a typical marine model organism, using a titration design. Increasing concentrations of PS-microplastic (2 μg/L, 20 μg/L, and 200 μg/L) were titrated against a constant concentration of Cd (15.2 μg/L). The results showed no significant impact of exposure to this dose of Cd or co-exposure to Cd and the lowest dose of PS-microplastic examined (2 μg/L). However, the feeding rate, filtration rate, oxygen consumption rate, and hatching number declined significantly in T. japonicus co-exposed to Cd and higher concentrations of PS-microplastic (20 μg/L and 200 μg/L) (p < 0.05). Furthermore, the development of F1 larvae from nauplius stage (N) to adult stage (A) was markedly delayed when co-exposed to Cd and higher doses of PS-microplastic (20 and 200 μg/L), and the effects persisted to the F2 larval stage. Interestingly, the present titration design did not affect the sex ratio or number of oocysts in either the F1 or F2 generation. These results indicated that the current marine environmental concentrations of Cd and microplastic are safe for wild organisms. Further studies are required to address the knowledge gap regarding toxicological effects at the cellular and molecular levels.

Objective: In this study, we aimed to develop an amino-terminal fragment (ATF) peptide-targeted liposome carrying β-elemene (ATF24-PEG-Lipo-β-E) for targeted delivery into urokinase plasminogen activator receptor-overexpressing bladder cancer cells combined with cisplatin (DDP) for bladder cancer treatment. Methods: The liposomes were prepared by ethanol injection and high-pressure microjet homogenization. The liposomes were characterized, and the drug content, entrapment efficiency, and in vitro release were studied. The targeting efficiency was investigated using confocal microscopy, ultra-fast liquid chromatography, and an orthotopic bladder cancer model. The effects of ATF24-PEG-Lipo-β-E combined with DDP on cell viability and proliferation were evaluated by a Cell Counting Kit-8 (CCK-8) assay, a colony formation assay, and cell apoptosis and cell cycle analyses. The anticancer effects were evaluated in a KU-19-19 bladder cancer xenograft model. Results: ATF24-PEG-Lipo-β-E had small and uniform sizes (˜79 nm), high drug loading capacity (˜5.24 mg/mL), high entrapment efficiency (98.37 ± 0.95%), and exhibited sustained drug release behavior. ATF24-PEG-Lipo-β-E had better targeting efficiency and higher cytotoxicity than polyethylene glycol (PEG)ylated β-elemene liposomes (PEG-Lipo-β-E). DDP, combined with ATF24-PEG-Lipo-β-E, exerted a synergistic effect on cellular apoptosis and cell arrest at the G2/M phase, and these effects were dependent on the caspase-dependent pathway and Cdc25C/Cdc2/cyclin B1 pathways. Furthermore, the in vivo antitumor activity showed that the targeted liposomes effectively inhibited the growth of tumors, using the combined strategy. Conclusions: The present study provided an effective strategy for the targeted delivery of β-elemene (β-E) to bladder cancer, and a combined strategy for bladder cancer treatment.

Background: Traditional Chinese medicine (TCM) syndrome, also named syndrome, are comprehensive and integral analyses of clinical information which helps to guide different individualized treatment prescriptions. Methods: Thirty healthy controls and 80 colorectal cancer (CRC) patients (including 33 Spleen Qi Deficiency syndrome, 23 Dampness heat Heat syndrome, 17 Blood stasis Stasis syndrome and 7 other syndrome) were enrolled into this study. Human mRNAs were extracted from peripheral blood mononuclear cells. The gene expression for CRC patients with different TCM syndrome was determined by microarray and qRT-PCR. Results: Spleen Qi Deficiency, Dampness Heat and Blood Stasis were the most common syndromes in CRC patients. There is a significant difference was found in mRNA expression levels (especially for PIK3CA, STAT3, SOX9 and KDM5C) among Spleen Qi Deficiency, Dampness Heat and Blood Stasis syndrome groups. The higher mRNA levels of JNK1, TP53, MLH1, MSH6, PMS2, SOCS3, TCF7L2, FAM123B, PSAP, FBXW7, SALL4 and the lower expression of inflammatory cytokine IL-6 were found in Spleen Qi Deficiency group but not other syndrome types. The higher mRNA levels of KRAS, MUC16, EGFR, GRASP65, PIK3CA, MAPK7, CD24, STAT3, SLC11A1, Bcl-2, TXNDC17 and some inflammatory cytokines (IL-6, IL-23, TNF-a, CXCR4) were found in Dampness Heat group but not other syndrome types. Blood Stasis syndrome showed higher expression of SOX9, MLH1, MSH6, KDM5C, PCDH11X, PSAP and SALL4, and lower mRNA levels of PIK3CA, CD24, STAT3, CXCR4, TXNDC17 and TP53. The CRC patients with Dampness Heat syndrome may might have a poor prognosis than other syndrome types. Conclusion: The identification of syndrome conditions had different impacts on CRC prognosis, and which may might be related with different mRNA expression levels. Some oncogenes and pro-inflammatory cytokines were highly expressed in Dampness Heat group but not other syndrome types, suggesting that the CRC patients with Dampness Heat syndrome may might have a poor prognosis. Our results prelimitarily uncovered the molecular basis of syndrome differences in CRC prognosis, a better understanding for TCM treatment of CRC.

5-Fluorouracil (5-FU) is known as a first-line chemotherapeutic agent against colorectal cancer (CRC), but drug resistance occurs frequently and significantly limits its clinical success. Our previous study showed that the protocadherin 17 (PCDH17) gene was frequently methylated and functioned as a tumor suppressor in CRC. However, the relationship between PCDH17 and 5-FU resistance in CRC remains unclear. Here, we revealed that PCDH17 was more highly expressed in 5-FU-sensitive CRC tissues than in 5-FU-resistant CRC tissues, and high expression of PCDH17 was correlated with high BECN1 expression. Moreover, this expression profile contributed to superior prognosis and increased survival in CRC patients. Restoring PCDH17 expression augmented the 5-FU sensitivity of CRC in vitro and in vivo by promoting apoptosis and autophagic cell death. Furthermore, autophagy played a dominant role in PCDH17-induced cell death, as an autophagy inhibitor blocked cell death to a greater extent than the pancaspase inhibitor Z-VAD-FMK. PCDH17 inhibition by siRNA decreased the autophagy response and 5-FU sensitivity. Mechanistically, we showed that c-Jun NH2-terminal kinase (JNK) activation was a key determinant in PCDH17-induced autophagy. The compound SP600125, an inhibitor of JNK, suppressed autophagy and 5-FU-induced cell death in PCDH17-reexpressing CRC cells. Taken together, our findings suggest for the first time that PCDH17 increases the sensitivity of CRC to 5-FU treatment by inducing apoptosis and JNK-dependent autophagic cell death. PCDH17 may be a potential prognostic marker for predicting 5-FU sensitivity in CRC patients.

Heavy metal pollution has become a great concern due to its adverse effects on the ecological system and human health. The present study investigated the concentrations of six common heavy metals (Cr, Cu, Zn, As, Cd, and Pb) in the Tianjin coastal area to understand their distribution, enrichment, sources, and potential ecological risk levels, focusing on the main contributors. The results showed that the concentration of Cu was high in the surface seawater (6.89 µg/L for the average), while Cd was the main contaminating metal in the sediments, with an average concentration of 0.77 mg/kg. The potential ecological risk index (RI) implied that the heavy metals in the sediments could cause considerable ecological risk, and Cd was the major contributor to ecological risk in this area. In particular, the field investigation showed that Cd contamination occurred as a result of anthropogenic activities, including port transportation, mariculture, and metal fabrication along the coastal area. Therefore, it is necessary to control Cd contamination in the future to improve the quality of the marine environment in Bohai Bay.

Purpose: To determine whether p53, PCDH17, Beclin-1 expression is associated with clinicopathological characteristics of bladder cancer. Materials and Methods: 75 patients with non-muscle-invasive and muscle-invasive bladder cancer were included. Immunohistochemical staining for p53, PCDH17 and Beclin-1 were carried out on the same paraffin-embedded blocks serial sections of these patients who underwent surgery between 2010 and 2015. In addition, p53 gene mutations in these tumors were screened by DNA sequencing. Results: Forty-nine (66.7%) of 75 tumors had p53 gene mutations detected by DNA sequencing method. Of these tumors, 43 (86.0%) exhibited p53 high expression. Furthermore, p53 mutation and low expression of PCDH17 were significantly associated with muscle-invasive bladder cancer. Beclin-1 was also strongly associated with T stage. The p53 mutation, the expression of p53 and PCDH17 were significantly associated with survival from bladder cancer. In addition, patients with p53 high-expression or p53 mutation, PCDH17 low-expression and Beclin-1 low-expression significantly had a poor prognosis. Conclusions: Use of a DNA sequencing method to detect p53 gene mutations was consistent with an immunohistochemical method to detect p53 alterations. In conjunction with levels of p53/PCDH17/Beclin-1, p53 and PCDH17 were independently associated with prognosis; Beclin-1 only had a tendency towards overall survival. p53/PCDH17/Beclin-1 phenotype seems to play a more important role than p53 expression in bladder cancer outcome. It is also identified that p53/PCDH17, p53/Beclin-1 or PCDH17/Beclin-1 all have a cooperative and synergistic effect, which may provide us the potential biomarker for bladder cancer patients.

N6-methyladenosine (m6A) modification can alter gene expression by regulating RNA splicing, stability, translocation, and translation. Emerging evidence shows that m6A modification plays an important role in cancer development and progression, including cell proliferation, migration and invasion, cell apoptosis, autophagy, and drug resistance. Until now, the role of m6A modification mediated autophagy in cancer drug resistance is still unclear. In this study, we found that m6A methyltransferase METTL3-mediated autophagy played an important role in reversing gefitinib resistance by β-elemene in non-small cell lung cancer (NSCLC) cells. Mechanistically, in vitro and in vivo studies indicated that β-elemene could reverse gefitinib resistance in NSCLC cells by inhibiting cell autophagy process in a manner of chloroquine. β-elemene inhibited the autophagy flux by preventing autophagic lysosome acidification, resulting in increasing expression of SQSTM1 and LC3B-II. Moreover, both β-elemene and gefitinib decreased the level of m6A methylation of gefitinib resistance cells. METTL3 was higher expressed in lung adenocarcinoma tissues than that of paired normal tissues, and was involved in the gefitinib resistance of NSCLC cells. Furthermore, METTL3 positively regulated autophagy by increasing the critical genes of autophagy pathway such as ATG5 and ATG7. In conclusion, our study unveiled the mechanism of METTL3-mediated autophagy in reversing gefitinib resistance of NSCLC cells by β-elemene, which shed light on providing potential molecular-therapy target and clinical-treatment method in NSCLC patients with gefitinib resistance.

Beauveria bassiana is an important entomopathogenic fungus used to control a variety of insect pests. Conidia are the infective propagules of the fungus. However, some important factors that influence conidiation are still to be investigated. In this study, a mutant with decreased conidial production and hyphal growth was identified from a random T-DNA insertional library of B. bassiana. The corresponding gene (Bbthi) for this mutation encodes a putative thiazole synthase. Thiazole and pyrimidine are structural components of thiamine (vitamin B1), which is an essential nutrient for all forms of life. Disruption of Bbthi, Bbpyr, a putative pyrimidine synthetic gene, or both in B. bassiana results in a significant decrease of thiamine content. Loss of Bbthi and Bbpyr function significantly decreased the conidial production and hyphal growth, as well as disrupted the integrity of conidial cell wall. However, the defect of Bbpyr and Bbthi does not decrease the virulence of B. bassiana. Our results indicate the importance of thiamine biosynthesis in conidiation of B. bassiana, and provide useful information to produce conidia of entomopathogenic fungi for biocontrol of insect pests.

N6-methyladenosine (m6A) modification can alter gene expression by regulating RNA splicing, stability, translocation, and translation. Emerging evidence shows that m6A modification plays an important role in cancer development and progression, including cell proliferation, migration and invasion, cell apoptosis, autophagy, and drug resistance. Until now, the role of m6A modification mediated autophagy in cancer drug resistance is still unclear. In this study, we found that m6A methyltransferase METTL3-mediated autophagy played an important role in reversing gefitinib resistance by β-elemene in non-small cell lung cancer (NSCLC) cells. Mechanistically, in vitro and in vivo studies indicated that β-elemene could reverse gefitinib resistance in NSCLC cells by inhibiting cell autophagy process in a manner of chloroquine. β-elemene inhibited the autophagy flux by preventing autophagic lysosome acidification, resulting in increasing expression of SQSTM1 and LC3B-II. Moreover, both β-elemene and gefitinib decreased the level of m6A methylation of gefitinib resistance cells. METTL3 was higher expressed in lung adenocarcinoma tissues than that of paired normal tissues, and was involved in the gefitinib resistance of NSCLC cells. Furthermore, METTL3 positively regulated autophagy by increasing the critical genes of autophagy pathway such as ATG5 and ATG7. In conclusion, our study unveiled the mechanism of METTL3-mediated autophagy in reversing gefitinib resistance of NSCLC cells by β-elemene, which shed light on providing potential molecular-therapy target and clinical-treatment method in NSCLC patients with gefitinib resistance.

Ferroptosis, a novel form of programmed cell death, is characterized by iron-dependent lipid peroxidation and has been shown to be involved in multiple diseases, including cancer. Stimulating ferroptosis in cancer cells may be a potential strategy for cancer therapy. Therefore, ferroptosis-inducing drugs are attracting more attention for cancer treatment. Here, we showed that erianin, a natural product isolated from Dendrobium chrysotoxum Lindl, exerted its anticancer activity by inducing cell death and inhibiting cell migration in lung cancer cells. Subsequently, we demonstrated for the first time that erianin induced ferroptotic cell death in lung cancer cells, which was accompanied by ROS accumulation, lipid peroxidation, and GSH depletion. The ferroptosis inhibitors Fer-1 and Lip-1 but not Z-VAD-FMK, CQ, or necrostatin-1 rescued erianin-induced cell death, indicating that ferroptosis contributed to erianin-induced cell death. Furthermore, we demonstrated that Ca2+/CaM signaling was a critical mediator of erianin-induced ferroptosis and that blockade of this signaling significantly rescued cell death induced by erianin treatment by suppressing ferroptosis. Taken together, our data suggest that the natural product erianin exerts its anticancer effects by inducing Ca2+/CaM-dependent ferroptosis and inhibiting cell migration, and erianin will hopefully serve as a prospective compound for lung cancer treatment.

Objective: This study aimed to develop a new polyethylene glycol (PEG)ylated β-elemene liposome (PEG-Lipo-β-E) and evaluate its characterization, pharmacokinetics, antitumor effects and safety in vitro and in vivo. Methods: The liposomes were prepared by ethanol injection and high-pressure micro-jet homogenization. Characterization of the liposomes was conducted, and drug content, entrapment efficiency (EE), in vitro release and stability were studied by ultra-fast liquid chromatography (UFLC) and a liquid surface method. Blood was drawn from rats to establish the pharmacokinetic parameters. The anticancer effect was evaluated in a KU-19-19 bladder cancer xenograft model. Histological analyses were performed to evaluate safety. Results: The PEG-Lipo-β-E showed good stability and was characterized as 83.31 ± 0.181 nm in size, 0.279 ± 0.004 in polydispersity index (PDI), −21.4 ± 1.06 mV in zeta potential, 6.65 ± 0.02 in pH, 5.024 ± 0.107 mg/mL in β-elemene (β-E) content, and 95.53 ± 1.712% in average EE. The Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) indicated the formation of PEG-Lipo-β-E. Compared to elemene injection, PEG-Lipo-β-E demonstrated a 1.75-fold decrease in clearance, a 1.62-fold increase in half-life, and a 1.76-fold increase in area under the concentration-time curves (AUCs) from 0 hour to 1.5 hours (P < 0.05). PEG-Lipo-β-E also showed an enhanced anticancer effect in vivo. Histological analyses showed that there was no evidence of toxicity to the heart, kidney, liver, lung or spleen. Conclusions: The present study demonstrates PEG-Lipo-β-E as a new formulation with ease of preparation, high EE, good stability, improved bioavailability and antitumor effects.

Background In China, traditional Chinese medicine (TCM) is an increasingly important part of the treatment of non-small cell lung cancer (NSCLC), which usually includes a combination of prescription and syndrome differentiation. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have been proven to be the first-line drugs for the treatment of advanced EGFR mutation-positive NSCLC. In China, EGFR-TKIs are used in combination with traditional Chinese medicines to reduce side effects and/or enhance effectiveness. Nevertheless, the relationship between TCMs and EGFR-TKIs remain unclear. This meta-review aimed to explore the clinical evidence of TCMs combined with EGFR-TKIs in the treatment of NSCLC. Methods Related studies were found by searching the databases of EMBASE, PubMed, Web of Science, MEDLINE, Cochrane library database, China Academic Journals (CNKI), Wanfang and Weipu. This study included 57 randomized controlled trials, all of these were processed by Stata software (version 12.0). In the study, all the materials are published articles, patient anonymity and informed consent and ethics Approval/Institutional review board are not necessary. Results This study demonstrated that the objective response rate was higher in the group of TCMs plus EGFR-TKIs than in the group of EGFR-TKIs alone (risk ratios 1.39, 95% confidence intervals [1.29, 1.50]). Further research of specific herbal medicines showed that Huangqi, Baishu, Fuling, Gancao, Maidong, Baihuashecao, Shashen, Dangshen and Renshen, had significant higher contributions to results. Conclusion TCMs may improve the efficacy of EGFR-TKIs in the treatment of NSCLC.

FeCo films with various thicknesses were fabricated by direct-current magnetron sputtering on corning glass and organic ferroelectric PVDF substrates at the same time with 5 nm Ru seed layer and 5 nm Ta protective layer. The in-plane uniaxial anisotropy field of FeCo on glass substrate increases from 24 to 36 Oe with the increase of FeCo film thickness from 5 to 100 nm. However, a large in-plane anisotropy field of FeCo on PVDF substrate increases with FeCo thickness from 5 to 20 nm and gradually decreases with the FeCo thickness further increasing. Atomic force microscope images of FeCo on glass show quite smooth surface with root-mean-square roughness around 0.5 nm and have none visible granules on the surface for all samples. While, AFM images of FeCo on PVDF show quite rough surface with RMS roughness around 25 nm and have visible granules with the smallest granules appearing at the FeCo thickness of 20 nm. The permeability spectra show the typical ferromagnetic resonance phenomenon and can be well fitted by the LLG equation with the obtained experimental parameters. The ferromagnetic resonance frequency can reach 7.0 GHz for the 20 nm FeCo film on PVDF. Moreover, the quality factor of this sample can respectively reach 26, 12 and 7 at 1.0, 2.0, and 3.0 GHz, indicating the potential real 3G application for high-frequency devices.

The interface has become an important issue in organic magnetic spin-valves. In this work, Si/FeCo/Ta, Si/FeCo/Bepp2/Ta, and Si/Bepp2/FeCo/Ta samples with the variation of the FeCo layer thickness were fabricated by direct-current magnetron sputtering for FeCo layers and the thermal evaporation method for Bepp2 layers. The interaction at the interfaces between the FeCo magnetic layer and Bepp2 organic layer was investigated by the traditional magnetic properties measurement and X-ray photoelectron spectroscopy with the Argon ion etching technique. The experimental results show that the interfacial reaction is strong when sputtering FeCo on Bepp2 layer due to the high energy of sputtered FeCo atoms in contrast with the weak interfacial reaction when evaporating Bepp2 on FeCo layer. Moreover, the capping layer of Ta is quite important to protect FeCo layer against oxidation from air either by direct contact or through Bepp2 layer. Our experiment is very helpful for fabricating organic spin-valves with high-spin injection efficiency.

Strip-like FeCo films were patterned by a traditional lithograph process from intrinsically isotropic continuous FeCo films. The strip-patterned FeCo film shows a strong in-plane uniaxial magnetic anisotropy with easy axis along the length direction of the strip. The angular dependences of remanence ratio, switching field, and coercivity indicate that the magnetization reversal mechanism of the strip-patterned FeCo film is coherent rotation and domain wall depinning when the applied field is near the hard axis and easy axis, respectively. The consistency of the experimental hysteresis loops of the strip-patterned FeCo film and calculated hysteresis loops with a simple in-plane uniaxial anisotropy model indicates that the strip-patterned FeCo film behaves as a single domain. The absence of the domain wall and the strong in-plane anisotropy field make the strip-patterned FeCo films have much potential for high-frequency application.

The field emission (FE) properties of vertically aligned carbon nanotube (CNT) arrays having a surface decorated with Ta layer were investigated. The CNTs with 6 nm thickness of Ta decoration showed improved FE properties with a low turn-on field of 0.64 V/mu m at 10 mu A/cm(2), a threshold field of 1.06 V/mu m at 1 mA/cm(2) and a maximum current density of 7.61 mA/cm(2) at 1.6 V/mu m. After Ta decoration, the increased emission centres and/or defect sites on the surface of CNTs improved the field enhancement factor. The work function of CNTs with Ta decoration measured with ultraviolet photoelectron spectroscopy decreased from 4.74 to 4.15 eV with increasing Ta thickness of 0-6 nm. The decreased work function and increased field enhancement factor were responsible for the improved FE properties of the vertically aligned CNTs. Moreover, a significant hysteresis in the cycle-testing of the current density with rising and falling electric field process was observed and attributed to the adsorption/desorption effect, as confirmed by the photoelectron spectrum. (C) 2014 Elsevier Ltd. All rights reserved.

The field emission behavior of aligned carbon nanotubes (CNTs) is remarkably improved by decorating their surfaces with Ti nanoparticles through a sputtering process. The CNT/Ti(4 nm) sample shows a low turn-on field of 0.63 V/lm at 10 mu A/cm(2), low threshold field of 1.06 V/mu m at 1 mA/cm(2), and maximum field emission current density of 23 mA/cm(2) at 1.80 V/mu m. The enhanced field emission properties of the CNT/Ti samples are attributed to the added defect sites and Ti nanoparticles, which increase the field enhancement factor and density of emission sites. Stability measurements indicate that the Ti coating, which acts as a protective layer, also strengthens the field emission stability of the CNT arrays. Moreover, the extent of hysteresis in the current-voltage sweep highly depends on the voltage-sweep speed. (C) 2013 Elsevier B.V. All rights reserved.

We analysed the relation between the boson peak in glasses and the van Hove singularity in crystals. The comparison of the experimental results obtained for amorphous iron to the published data for two different iron crystals suggests that the appearance of the pseudo-Brillouin zone with corresponding flattening of the dispersion relations and the resulting boson peak in glasses are the fundamental effects caused by a finite and well-defined value of interatomic distance, i.e. simply by an atomistic character of nature. Accordingly, the Brillouin zone and the van Hove singularities in crystals can be considered as the crystalline counterparts, or ‘derivatives’, of these ‘glassy’ quantities. In addition, we analyse the options for observing the excess states in glasses caused by another effect, i.e. by phonon scattering. Possibly, this is indeed seen in the reduced DOS of ambient silica glass and amorphous iron in the 1–2 meV energy range.

The magnetic spectra of two magnetostatic coupled ferromagnetic stripes with different distances were investigated by the three-dimensional object oriented micromagnetic framework (OOMMF) code. The studied systems exhibit two resonance peaks. The higher peak can be identified with the bulk mode predicted by the macroscopic LL model. The lower peak originates from edge magnetic moments. Influence of magnetostatic interaction on the two resonance models was studied in detail. As the distance between two stripes increases, the magnetic spectrum of two stripes is close to the case of a single stripe.

Co nanowire arrays with three typical diameters of 20, 50 and 120 nm have been fabricated into anodic alumina oxide templates using an ac electrodeposition method. It is found that the crystal texture of the Co nanowires depends on the pH value of the deposition electrolyte. X-ray diffraction results show that the (1 0 0) texture appears at pH 6.2, while the diffraction peaks of (1 0 0) and (1 0 1) appear at pH 6.4 with the diameter of 20 nm. In addition, the (0 0 2), (1 0 0) and (1 0 1) peaks appear with an increase of pH value for the nanowire arrays with diameters of 50 and 120 nm, respectively. Magnetic measurements indicate the effect of structure on the magnetic properties of the nanowire arrays, which depend strongly on the different diffraction peaks, as adjusted by the pH value.

Developing high frequency soft magnetic thin films is still a hot issue due to the requirement of the technology in high frequency field. Traditionally, tuning the high frequency performance of magnetic thin films is realized by tuning the in-plane uniaxial anisotropy field of magnetic thin films with amorphous or nanocrystalline structure. There are several methods to obtain the in-plane uniaxial magnetic anisotropy such as applying an in-plane magnetic field during thin film deposition, magnetic field annealing, addition of elements or compounds, and patterned thin films to create shape anisotropy method [1]. Moreover, with the increase of the grain size, the high frequency performance becomes worse due to the decrease of the in-plane uniaxial anisotropy field and associated the cut-off frequency according to the random exchange anisotropy model of Herzer [2]. However, there are few works are concerned the high frequency properties of epitaxial single crystal film. In this work, Fe0.84Si0.16 (FeSi)/Ta (5 nm) thin films with thickness of 70 nm have been deposited on (001) MgO substrates by rf magnetron sputtering at 400 °C with a base pressure below 3'10 −5 Pa and a processing Ar pressure of 0.2 Pa, and then heat-treated for 1 h at 800 °C with the heating rate of 50 °C/min. MgO/FeSi/Ta shows (002) and (004) peaks, which indicated that FeSi(001)[110]//MgO(001) [100] film is epitaxial growth. The mainly chemical order phase is B2 with a significant A2 disorder phase according to the X-rays diffraction peak intensity ratio [3]. Angular dependence of remanence ratio (ARR) and hysteresis loops with the magnetic field applied parallel to in-plane film were measured by vibrating sample magnetometer (VSM) at room temperature. A four-fold symmetry of remanence ratio from the ARR graph was observed, indicating the cubic magnetic crystalline anisotropy of FeSi films. However two adjacent easy axis direction remanence ratios are not completely equivalent, which may be caused by a superstition of an extra in-plane uniaxial anisotropy with easy axis along the [100] direction as shown in Fig. 1. Thus, we may conclude the presence of a superstition of a strong four-fold magneto-crystalline anisotropy and a small in-plane uniaxial magnetic anisotropy with easy magnetization axis along the [100] and [010] crystallographic directions of FeSi and hard magnetization axis along the [110] and [110] crystallographic directions. The saturation field along [110] direction reaches 550 Oe and the saturation magnetization is about 13 kGs. The dynamic magnetic properties are investigated by the one-terminal micro-strip transmission-line perturbation method in the frequency range 0.1–9 GHz. The permeability spectra are shown in Fig. 2 with an extra magnetic field applied along the [100] easy axis direction. One can see the natural ferromagnetic resonance frequency is around 8.0 GHz for epitaxial FeSi thin films on (001) MgO substrate. The quite large resonance frequency is ascribed to the large magneto crystalline anisotropy field of FeSi films with cubic anisotropy. The obtained Gibert damping constant (a) through fitting the complex permeability (μ") based on Lan-dau-Lifshitz-Gibert equation with the variation of applied magnetic field is around 0.016, which is larger than that of pure Fe film. It maybe understood by the chemical disorder of Fe and Si atoms with A2 structure.

The epitaxial growth of FeSi film on (001) 0.68Pb(Mg1/3Nb2/3)O3-0.32PbTiO3 (PMN-0.32PT) was fabricated by sputtering and confirmed by high-resolution transmission electron microscopy. A fourfold symmetric angular remanent magnetization curve of as-deposited FeSi thin film is well fitted theoretically by considering the cubic magnetocrystalline anisotropy. We found that the fourfold anisotropy decreases slightly when an electric field (E) is applied on the Pt/PMN-0.32PT/FeSi/Ta heterostructures with Pt layer as the positive electrode. However, a magnetic anisotropy transition from fourfold anisotropy to twofold anisotropy occurs under negative E. The strain-electric field curve suggests that the observed different variation trend of magnetic anisotropy results from the asymmetric strain response on the polarity of E. Moreover, once the transition happens, it was irreversible unless the heterostructures are heated above the phase transition temperature of PMN-0.32PT.

Co2FexMn1−xSi (0 ≦ x ≦ 1) Heusler alloys were fabricated by arc-melting the stoichiometric quantities of the constituents. We investigated the magnetic properties, geometric structure simulation, and real crystal structure for powder samples and the magnetic damping constant for polished thin-disk samples. All samples show high Curie temperatures, and the molecular magnetic moment increases with Fe concentration. The theoretical atomic site occupation of Co2FexMn1−xSi Heusler alloys with A2, B2, and L21 structures were simulated by Diamond 3.2. The real crystal structure was studied via x-ray diffraction measurement, followed by both Rietveld refinement and 57Fe Mossbauer spectroscopy. The result indicates that in addition to the main phase of L21, some B2 phases coexist in the samples, which will decrease the gap at the Fermi level and destroy half metallicity. The corresponding magnetic damping constant, deduced from the ferromagnetic resonance, decreases as the concentration of the L21 phase increases. Therefore, the ordered L21 structure is the key factor for improving the half metallicity and decreasing the magnetic damping constant. The results suggest that the Co2Fe0.7Mn0.3Si Heusler alloy with a 100% L21 phase is more suitable for applications.

An electric-field pulses driven magnetoelectric memory cell in a single layered ferromagnetic thin film was fabricated by direct-current magnetron sputtering Ru/Fe65Co35 on ferroelectric (110) [Pb(Mg1/2 Nb2/3)O3]0.68-[PbTiO3]0.32 (PMN-PT) substrates. The magnetization in the orthogonal directions can be reset by the positive/negative electric fields pulse in PMN-PT/Ru/FeCo heterostructures due to the strain mediated converse magnetoelectric effect. The high (low) resistance state was realized under the negative (positive) electric fields pulse due to the anisotropy magnetoresistance of FeCo films. Then, a non-volatile magnetic memory cell with resistance and electric field, respectively, as the media and writing field was realized.

Magnetic damping constant (α) is one of the key parameters to determine the critical current density of spin-transfer-torque devices and the switching time of magnetization for ultra-high-frequency devices. In this work, Gd doped FeCo films were fabricated to investigate α based on the ferromagnetic resonance technique. Gd doping not only can efficiently decrease the magnetic inhomogeneity and the extrinsic part of α but also the Lande g-factor and intrinsic part of α. The obtained α was roughly proportional to (g-2)2 and the magnetic anisotropic constant, indicating that the decreased spin-orbit interaction decreases α by Gd doping.

Large electric field tunable remanent magnetization and in-plane anisotropy in a Fe65Co35 film was observed in sputtered ferromagnetic/ferroelectric heterostructures. Two stable magnetization directions were established through a 90° transition of the in-plane uniaxial anisotropy of FeCo film under a positive electric field, and large nonvolatile remanence ratio tunability between 0.50 and 0.12 was realized using electric field pulses. With the increase of negative electric field, the anisotropy field increases at a rate of around 31.1 Oe/(kV cm−1). The large tunable anisotropy field and remnant magnetization may have potential applications in electrically tunable microwave magnetic devices and information storage memories.

Amorphous tris-(8-hydroxyquinoline) aluminum (Alq(3)) layers, which first form Alq(3) islands and then grow into submicrometre thorns, with different nominal thicknesses are investigated. The field emission characteristics of Alq(3) submicrometre thorns with nominal thicknesses of 20 nm, 50 nm and 100 nm include low turn-on fields of 3.2V mu m(-1), 6.8V mu m(-1) and 9.0V mu m(-1) at 10 mu Acm(-2), and low threshold fields of 5.1V mu m(-1), 10.0V mu m(-1) and 13.0V mu m(-1) at 1mAcm(-2), respectively. The enhanced field emission properties are governed by the morphology of Alq(3) submicrometre thorns, which can be controlled by the evaporation rate and the layer thickness. A significant hysteresis in the cycle testing of the current density with a rise and fall electric field process, which is an undesirable property for practical applications, is observed in the case of the considered samples. This hysteresis can be eliminated via an increase in the nominal thicknesses and tests, and this is important for practical applications. The microstructure and adsorption/desorption effect are responsible for this hysteresis phenomenon. Amorphous Alq(3) submicrometre thorns with good field emission properties are promising candidates for application as field emitters.

The CrO2 micro rod powder was synthesized by decomposing the CrO3 flakes at a specific temperature to yield precursor and annealing such a precursor in a sealed glass tube. The magneto-transport properties have been measured by a direct current four-probe method using a Cu/CrO2 rods/colloidal silver liquid electrode sandwich device. The largest magnetoresistance (MR) around ~72 % was observed at 77 K with applied current of 0.05 μA. The non-linear I–V curve indicates a tunneling type transport properties and the tunneling barrier height is around 2.2 ± 0.04 eV at 77 K, which is obtained with fitting the non-linear I–V curves using Simmons’ equation. A mixing of Cr oxides on the surface of CrO2 rod observed by X-ray photoemission spectroscopy provides a tunneling barrier rather than a single phase of Cr2O3 insulating barrier. The MR shows strong bias voltage dependence and is ascribed to the two-step tunneling process.