[Sorafenib regulates vascular endothelial growth factor by runt-related transcription factor-3 to inhibit angiogenesis in hepatocellular carcinoma].

Objective: To investigate the molecular mechanism of sorafenib against hepatocellular carcinoma. Methods: Sorafenib efficacy was screened and verified by the hepatocellular carcinoma patient-derived tumor xenograft (PDX) model. Veterinary B-mode ultrasonography and in vivo confocal laser scanning microscopy were used to observe PDX angiogenesis. Immunohistochemistry was used to observe the expression of proliferation and angiogenesis-related proteins in PDX tissue. Real-time quantitative PCR technology was used to observe the RUNX3 gene in PDX tissues. SPSS 17.0 statistical software was used for statistical analysis. Results: Four cases of PDX were used to screen the efficacy of sorafenib. PDX1 had a significant response to sorafenib, with an inhibition rate of 68.07%. Compared with the control group, sorafenib had significantly inhibited PDX1 relative tumor volume (5.76±2.14 vs. 11.71±2.87, P<0.05). Cell division index (39.50±7.72 vs. 67.10±9.14, P<0.05) and Ki67 expression (288.6±43.40 vs. 531.70±55.60, P<0.05) were significantly decreased. Veterinary B-mode ultrasonography showed evident blood flow signals in PDX1 tumors. In vivo confocal laser scanning microscopy results showed that sorafenib had significantly reduced the total vessel length (1573.00±236.21 vs. 2675.03±162.00, P<0.05) and area (11 145.33±1931.97 vs. 20 105.37±885.93, P<0.05)) of PDX1 tumors. Immunohistochemical results showed that sorafenib had significantly down-regulated the protein expressions of CD34 (27.55±3.76 vs. 45.47±5.57, P<0.05), VEGF (16.33±2.86 vs. 22.77±3.20, P<0.05) and MVD (38.75±6.01 vs. 55.50±8.61, P<0.05). Real-time PCR results showed that sorafenib had significantly up-regulated RUNX3 gene expression (2.14±0.71 vs. 1.00±0.36, P<0.05). However, there was a negative correlation between the expression of RUNX3 gene and the ratio of VEGF-positive cells in sorafenib group (R2=0.509 7). Conclusion: Sorafenib may inhibit the PDX angiogenesis and the growth of hepatocellular carcinoma by regulating the RUNX3-VEGF pathway.

[Interference of long noncoding RNA FOXCUT inhibits epithelial-mesenchymal transformation and induces mitochondrial injury in nasopharyngeal carcinoma cells].

OBJECTIVE: To investigate the effects of RNA interference of long noncoding RNA FOXCUT on epithelial mesenchymal transformation and mitochondrial function in nasopharyngeal carcinoma (NPC) cells. METHODS: FOXCUT expression levels were detected by RT-PCR in tumor tissues and adjacent tissues from 50 patients with NPC and in NP69, CNE1, CNE2, SUNE2, HER2 and 5-8F cell lines. CNE1 cells were transfected with a short hairpin RNA (shRNA) targeting FOXCUT or a negative control RNA construct (shRNA-NC), and the changes in cell proliferation and morphology were assessed with CCK8 assay, clone formation assay and microscopic observation. An immunofluorescence assay was used to examine the vimentin-positive cells, and the levels of SOD, MDA and LDH in the cells were detected. The changes of mitochondrial membrane potential were detected with flow cytometry, and the expression levels of E-cad, N-cad, vimentin, Bax, Bcl-2, caspase-3 and c-Myc in the cells were detected with Western blotting. RESULTS: The expression level of FOXCUT was significantly increased in NPC tissues as compared with the adjacent tissues (P < 0.001). Compared with NP69 cells, CNE1, CNE2, SUNE2, HER2 and 5-8F cells all exhibited significantly increased expressions of FOXCUT (P < 0.001). In CNE1 cells, transfection with FOXCUT shRNA significantly inhibited cell proliferation and clone formation (P < 0.001), and caused obvious changes in cell morphology. FOXCUT knockdown significantly decreased the expressions of N-cad and vimentin, increased E- cad expression and the contents of MDA and LDH (P < 0.05), reduced vimentin- positive cells and the activity of SOD, and caused a shift of red fluorescent cells to green fluorescent cells and an increased percentage of green fluorescent cells. FOXCUT knockdown also resulted in significantly increased expressions of Bax/Bcl2 and cleaved Cas3/Cas3 and a lowered expression of c-Myc. CONCLUSIONS: Interference of FOXCUT can inhibit the proliferation and epithelial-mesenchymal transformation, enhance oxidative stress, induce mitochondrial function injury, and promote apoptosis in NPC cells, suggesting the potential of FOXCUT interference for targeted treatment of NPC.

Screening, identification, purification and homologous modeling of marine cold-active alpha-amylase.

BACKGROUND: Cold-active α-amylase is essential in industrial production. However, the number of cold-active α-amylases available for use is limited. Screening microbial strains would lay the groundwork for the future development of the food and pharmaceutical industries. OBJECTIVE: To screen microbial strains for cold-active α-amylase based on physiological and biochemical identification, as well as homology modelling. MATERIALS AND METHODS: Cold-active α-amylase strains were screened from water and mud obtained from the Yellow Sea. Colony morphology, Gram staining, scanning electron microscopy and transmission electron microscopy, physiological and biochemical identification and 16S rRNA gene analysis were used to identify strains. A series of steps, including DEAE-anion exchange column chromatography, SephadexG-100 column chromatography, and SDS-PAGE electrophoresis, were used to produce cold-active α-amylase of relatively high purity. Finally, the homology of amylase was modeled to explore the structure and activity site of the enzyme. RESULTS: The named dsh19-1 strain of cold-active α-amylase was screened and identified as Bacillus. The cold-active α-amylase produced by Bacillus was named AmyD-1. The protein with PDB sequence number 5A2B was found to have 40.6% homology with AmyD-1. The verification score of the 3-D model was 137.07 points. We discovered that the six sites are potential sites for amylase to decompose starch by building a 3-D AmyD-1 model. AmyD-1 has a molecular weight of 1515 bp, and hydrogen bonding may be the primary interaction force between AmyD-1 and glucose molecules. CONCLUSION: A cold-active α-amylase produced by Bacillus strain dsh19-1 was successfully obtained and named AmyD-1. This enzyme has potential uses in the food and pharmaceutical industries.

[A special on epidemic prevention and control: analysis on expression of 2019-nCoV related ACE2 and TMPRSS2 in eye tissues].

This article was published ahead of print on the official website of Chinese Journal of Ophthalmolog on Apirl 22,2020. Objective: Angiotensin converting enzyme 2 (ACE2) and Transmembrane serine protease 2 (TMPRSS2) are the key proteins for 2019-nCoV entry into host cells. To evaluate the potential infection risk of 2019-nCoV on ocular surface, we compared ACE2 and TMPRSS2 expression among different eye tissues. Methods: Experimental study. Thirty mice were assigned to male, female, aged, diabetic and non-diabetic groups, with 6 mice in each group. Real-time PCR was performed to quantify ACE2 and TMPRSS2 gene expression in conjunctiva, cornea, lacrimal gland, iris, lens, retina, lung, heart, kidney, and liver from male mice. Immunohistochemistry staining was applied to visualize the distribution of the two proteins in different mice tissues, and in human corneal and conjunctival sections. Published transcriptome datasets were extracted to generate the expression comparasion of ACE2 and TMPRSS2 between human conjunctival and corneal tissues, and results were analyzed using Mann-Whitney U test. Female mice, aged mice, STZ-induced diabetic mice, diabetic group control mice were also subjected to ACE2 expression analysis. Results were analyzed using Student's t-test. Results: The expression of ACE2 and TMPRSS2 genes were the highest in conjunctiva among all the six mice eye tissues explored. The expression of these two genes in conjunctiva were lower than that in kidney and lung. ACE2 and TMPRSS2 shared similar expression pattern with the staining concentrated in corneal epithelium, conjunctival epithelium and lacrimal gland serous cells. The expression levels of ACE2 showed gender difference. Female mice had lower ACE2 in conjunctiva and cornea than male mice, with the expression levels being only 43% (t=3.269, P=0.031) and 63% (t=4.080, P=0.015) of that in the male conjunctiva and cornea, respectively. Diabetic mice expressed more ACE2 in conjunctiva (1.21-fold, P>0.05) and lacrimal gland (1.10-fold, P>0.05) compared with the control group. No significant difference on ACE2 expression was found between the aged and young adult mice. The expression level of human conjunctiva ACE2 and TMPRSS2 were significantly higher than that in the cornea (P=0.007), with 5.74-fold and 12.84-fold higher in the conjunctiva than in the corneal epithelium cells, which resembled the situation in mice. Conclusion: The observation of high-level ACE2 and TMPRSS2 expression in conjunctiva among the 6 eye tissues examined suggests that conjunctiva serves as an infection target tissue of 2019-nCoV. (Chin J Ophthalmol, 2020, 56:438-446).

Omitting the lower neck and sparing the glottic larynx in node-negative nasopharyngeal carcinoma was safe and feasible, and improved patient-reported voice outcomes.

BACKGROUND: Worsening voice and speech quality was frequently reported in head-and-neck patients after radiotherapy to the neck; omitting the lower neck and sparing the glottic larynx in node-negative nasopharyngeal carcinoma (NPC) patients might be safe and feasible, and improve voice and speech outcomes. METHODS: From January 2009 to January 2013, 71 patients were analyzed. All patients received bilateral neck irradiation. Upper group (UG) patients spared the glottic larynx while lower group (LG) patients did not. Voice and speech quality were evaluated at two time-points (T1 and T2) using the Communication Domain of the Head and Neck Quality of Life (HNQOL) instrument and the Speech question of the University of Washington Quality of Life instrument. RESULTS: At a median follow-up time of 32 months (T1),71.6% of patients reported worsened voice and speech quality. UG patients resulted in significant decreases in glottic larynx dose. With a median follow-up time of 71 months (T2), no patients experienced out-of-field nodal recurrence;there was no difference in the 5-year overall survival and nodal recurrence-free survival between two groups (P = 0.235 and 0.750, respectively). At T1, in patients who without concurrent chemotherapy (CCT), UG patients showed significantly better patient-reported voice quality, (P = 0.022). UG patients without CCT also showed higher scores in the HNQOL communication domain and pain domain (P = 0.012 and P = 0.019). CONCLUSIONS: For node-negative NPC patients, omitting the lower neck and sparing the glottic larynx was safe and feasible, and better voice outcomes were achieved in patients without CCT. Further prospective longitudinal studies to investigate whether this approach would be beneficial to node-negative patients are warranted.

High toxicity of Bi(OH)3 and α-Bi2O3 nanoparticles towards malignant 9L and MCF-7 cells.

Here we report the extreme toxicity in vitro of Bi(OH)3 and α-Bi2O3 nanoparticles (NPs), obtained through a facile synthesis with an average single particle size of 6-10 nm, tested on malignant gliosarcoma 9L and MCF-7 human breast cancer cells. For both nanomaterials, clonogenic assays reveal a mortality of over 90% in 9L and MCF-7 cells for a concentration of 50 µg/mL after incubation for 24 h. Moreover, the NPs show a significant mortality of up to 60% in the malignant cells at the very low concentration of 6.25 µg/mL. In contrast, at the same concentration, the nanomaterials exhibit no noticeable mortality towards normal Madin-Darby canine kidney cells. The internalisation of the NPs was demonstrated using flow cytometry and confocal microscopy was used to investigate when the loss of cell viability starts. The NPs show a faster cell death in 9L cells compared with MCF-7 cells, demonstrated via the identification of apoptosis through increased sub G1 levels after 24 h of NP incubation. Cleavage is identified as the main apoptotic nuclear morphology in 9L, which suggests the presence of reactive oxygen species.

Enhanced energy transfer in heterogeneous nanocrystals for near infrared upconversion photocurrent generation.

The key to produce inorganic heterogeneous nanostructures, and to integrate multiple functionalities, is to enhance or at least retain the functionalities of different components of materials. However, this ideal scenario is often deteriorated at the interface of the heterogeneous nanostructures due to lattice mismatches, resulting in downgraded performance in most hybrid nanomaterials. Here, we report that there is a narrow window in controlling temperature in a Lewis acid-base reaction process to facilitate epitaxial alignment during the synthesis of hybrid nanomaterials. We demonstrate a perfectly fused NaYF4:Yb,Tm@ZnO heterogeneous nanostructure, in which the semiconductor ZnO shell can be epitaxially grown onto lanthanide-doped upconversion nanoparticles. By achieving a matched crystal lattice, the interface defects and crystalline grain boundaries are minimized to enable more efficient energy transfer from the upconversion nanoparticles to the semiconductor, resulting in both enhanced upconversion luminescence intensity and superior photoelectrochemical properties. This strategy provides an outstanding approach to endow lanthanide-doped upconversion nanoparticles with versatile properties.

Study of flux pinning mechanism under hydrostatic pressure in optimally doped (Ba,K)Fe2As2 single crystals.

Strong pinning depends on the pinning force strength and number density of effective defects. Using the hydrostatic pressure method, we demonstrate here that hydrostatic pressure of 1.2 GPa can significantly enhance flux pinning or the critical current density (Jc) of optimally doped Ba0.6K0.4Fe2As2 crystals by a factor of up to 5 in both low and high fields, which is generally rare with other Jc enhancement techniques. At 4.1 K, high pressure can significantly enhance Jc from 5 × 10(5 )A/cm(2) to nearly 10(6 )A/cm(2) at 2 T, and from 2 × 10(5 )A/cm(2) to nearly 5.5 × 10(5 )A/cm(2) at 12 T. Our systematic analysis of the flux pinning mechanism indicates that both the pinning centre number density and the pinning force are greatly increased by the pressure and enhance the pinning. This study also shows that superconducting performance in terms of flux pinning or Jc for optimally doped superconducting materials can be further improved by using pressure.

Ruminococcus gnavus E1 modulates mucin expression and intestinal glycosylation.

AIMS: The molecular cross-talk between commensal bacteria and the gut play an important role in the maintenance of the intestinal homeostasis and general health. Here, we studied the impact of a major Gram-positive anaerobic bacterium of the human gut microbiota, that is, Ruminococcus gnavus on the glycosylation pattern and the production of intestinal mucus by the goblet cells. METHODS AND RESULTS: Our results showed that R. gnavus E1 specifically increases the expression and the glycosylation level of the intestinal glyco-conjugates by goblet cells in the colonic mucosa of mono-associated mice with R. gnavus E1 as well as in human HT29-MTX cells. Such an effect was mediated through induction of the level of mRNA encoding for the major intestinal gel-forming mucin such as MUC2 and various glycosyltransferase enzymes. CONCLUSIONS: This study demonstrates for the first time that R. gnavus E1 possess the ability to modulate the glycosylation profile of the glyco-conjugate molecules and mucus in goblet cells. SIGNIFICANCE AND IMPACT OF THE STUDY: Furthermore, we demonstrated that R. gnavus E1 modified specifically the glycosylation pattern and MUC2 expression by means of a small soluble factor of peptidic nature (<3 kDa) and heat stable in the HT29-MTX cell.

Weekly cetuximab concurrent with IMRT aggravated radiation-induced oral mucositis in locally advanced nasopharyngeal carcinoma: Results of a randomized phase II study.

BACKGROUND: To evaluate the clinical efficacies and toxicities of induction chemotherapy followed by concomitant cisplatin-chemoradiotherapy (CRT) or cetuximab-radiotherapy (ERT) in locally advanced nasopharyngeal carcinoma (NPC). METHODS: Previously untreated patients with stage III-IVb NPC were eligible. They were randomized to CRT arm: intensity modulated radiation therapy (IMRT) with weekly cisplatin (30 mg/m(2)/w) or ERT arm: IMRT with weekly cetuximab (loading dose of 400 mg/m(2) followed by weekly doses of 250 mg/m(2)). Two cycles of induction chemotherapy (docetaxel 75 mg/m(2) d1 and cisplatin 80 mg/m(2) d1) were administered to both arms. Endpoints were survivals, toxicities and quality of life (QoL). RESULTS: Because of the unexpectedly high rates of grade 3/4 mucositis observed in the ERT arm, the study was closed ahead of schedule. A total of 44 patients (23 in CRT arm and 21 in ERT arm) were enrolled. All patients completed the scheduled induction chemotherapy and radical radiotherapy. The results showed better compliance (P<0.001) with more oral mucositis, acneiform rash and dysphagia (P<0.05) of cetuximab. The 3-year disease-free survival (DFS) were achieved as 78.3% and 85.7% (P=0.547) in CRT and ERT arm, respectively. In the analysis of QoL, the addition of cetuximab to radiotherapy temporarily increased the adverse symptoms but did not result in long-term dysfunction. CONCLUSIONS: ERT was not more efficacious than CRT but was more likely to cause acute adverse events in LA NPC. The recommended treatment modality was still concurrent cisplatin-IMRT. The combination of TP induction chemotherapy and concurrent cetuximab-radiotherapy should only be used in selected patients.

Tuneable Magnetic Phase Transitions in Layered CeMn2Ge(2-x)Six Compounds.

The structural and magnetic properties of seven CeMn2Ge(2-x)Six compounds with x = 0.0-2.0 have been investigated in detail. Substitution of Ge with Si leads to a monotonic decrease of both a and c along with concomitant contraction of the unit cell volume and significant modifications of the magnetic states - a crossover from ferromagnetism at room temperature for Ge-rich compounds to antiferromagnetism for Si-rich compounds. The magnetic phase diagram has been constructed over the full range of CeMn2Ge(2-x)Six compositions and co-existence of ferromagnetism and antiferromagnetism has been observed in CeMn2Ge1.2Si0.8, CeMn2Ge1.0Si1.0 and CeMn2Ge0.8Si1.2 with novel insight provided by high resolution neutron and X-ray synchrotron radiation studies. CeMn2Ge(2-x)Six compounds (x = 0, 0.4 and 0.8) exhibit moderate isothermal magnetic entropy accompanied with a second-order phase transition around room temperature. Analysis of critical behaviour in the vicinity of TC(inter) for CeMn2Ge2 compound indicates behaviour consistent with three-dimensional Heisenberg model predictions.

On the roles of graphene oxide doping for enhanced supercurrent in MgB2 based superconductors.

Due to their graphene-like properties after oxygen reduction, incorporation of graphene oxide (GO) sheets into correlated-electron materials offers a new pathway for tailoring their properties. Fabricating GO nanocomposites with polycrystalline MgB2 superconductors leads to an order of magnitude enhancement of the supercurrent at 5 K/8 T and 20 K/4 T. Herein, we introduce a novel experimental approach to overcome the formidable challenge of performing quantitative microscopy and microanalysis of such composites, so as to unveil how GO doping influences the structure and hence the material properties. Atom probe microscopy and electron microscopy were used to directly image the GO within the MgB2, and we combined these data with computational simulations to derive the property-enhancing mechanisms. Our results reveal synergetic effects of GO, namely, via localized atomic (carbon and oxygen) doping as well as texturing of the crystals, which provide both inter- and intra-granular flux pinning. This study opens up new insights into how low-dimensional nanostructures can be integrated into composites to modify the overall properties, using a methodology amenable to a wide range of applications.

Simulation of the phase diagram of magnetic vortices in two-dimensional superconductors: evidence for vortex chain formation.

We study the superconducting vortex states induced by the interplay of long-range Pearl repulsion and short-range intervortex attraction using Langevin dynamics simulations. We show that at low temperatures the vortices form an ordered Abrikosov lattice both in low and high fields. The vortices show distinctive modulated structures at intermediate fields depending on the effective intervortex attraction: ordered vortex chain and kagome-like vortex structures for weak attraction; bubble, stripe and antibubble lattices for strong attraction. Moreover, in the regime of the chain state, the vortices display structural transitions from chain to labyrinthine (or disordered chain) and/or to disordered states depending on the strength of the disorder.

Magnetism and magnetic structures of PrMn2Ge2-xSix.

The structural and magnetic properties of seven PrMn2Ge2-xSix compounds with Si concentrations in the range x = 0.0-2.0 have been investigated by x-ray diffraction, magnetic (5-350 K), differential scanning calorimetry (300-500 K) and neutron diffraction (3-480 K) measurements. Replacement of Ge by Si leads to a contraction of the unit cell and significant modifications to the magnetic states--a crossover from ferromagnetism at room temperature for Ge-rich compounds to antiferromagnetism for Si-rich compounds. The compositional dependence of the room temperature lattice parameters exhibits non-linear behaviour around x = 1.2, reflecting the presence of magnetovolume effects. Re-entrant ferromagnetism has been observed in both PrMn2Ge1.0Si1.0 and PrMn2Ge0.8Si1.2 compounds with co-existence of canted ferromagnetism and canted antiferromagnetism detected, with both compounds exhibiting a larger unit cell volume in the canted Fmc state than in the canted AFmc. Combined with earlier studies of this system, the magnetic phase diagram has been constructed over the full range of PrMn2Ge2-xSix compositions (x = 0.0-2.0) and over the temperature range of interest (T = 3-480 K). In common with other systems in the RMn2X2 series, the overall magnetic behaviour of PrMn2Ge2-xSix compounds is governed by the strong dependence of the magnetic couplings on the Mn-Mn spacing within the ab-plane. Both total manganese moment µ(Mn)(tot) and in-plane manganese moment µ(Mn)(ab) at 5 K are found to decrease with increasing Si content, which can be ascribed to the reduction of Mn-Mn separation distance and stronger Si-Mn hybridization compared with Ge-Mn hybridization. Pr site ferromagnetic ordering occurs for x < 1.6 below T(Pr)(C).

Driving magnetostructural transitions in layered intermetallic compounds.

We report the dramatic effect of applied pressure and magnetic field on the layered intermetallic compound Pr(0.5)Y(0.5)Mn(2)Ge(2). In the absence of pressure or magnetic field this compound displays interplanar ferromagnetism at room temperature and undergoes an isostructural first order magnetic transition (FOMT) to an antiferromagnetic state below 158 K, followed by another FOMT at 50 K due to the reemergence of ferromagnetism as praseodymium orders (T(C)(Pr)). The application of a magnetic field drives these two transitions towards each other, whereas the application of pressure drives them apart. Pressure also produces a giant magnetocaloric effect such that a threefold increase of the entropy change associated with the lower FOMT (at T(C)(Pr)) is seen under a pressure of 7.5 kbar. First principles calculations, using density functional theory, show that this remarkable magnetic behavior derives from the strong magnetoelastic coupling of the manganese layers in this compound.

The magnetocaloric effect and critical behaviour of the Mn(0.94)Ti(0.06)CoGe alloy.

Structural, magnetic and magnetocaloric properties of the Mn(0.94)Ti(0.06)CoGe alloy have been investigated using x-ray diffraction, DC magnetization and neutron diffraction measurements. Two phase transitions have been detected, at T(str) = 235 K and T(C) = 270 K. A giant magnetocaloric effect has been obtained at around T(str) associated with a structural phase transition from the low temperature orthorhombic TiNiSi-type structure to the high temperature hexagonal Ni(2)In-type structure, which is confirmed by neutron study. In the vicinity of the structural transition, at T(str), the magnetic entropy change, -ΔS(M) reached a maximum value of 14.8 J kg(-1) K(-1) under a magnetic field of 5 T, which is much higher than that previously reported for the parent compound MnCoGe. To investigate the nature of the magnetic phase transition around T(C) = 270 K from the ferromagnetic to the paramagnetic state, we performed a detailed critical exponent study. The critical components γ, ß and δ determined using the Kouvel-Fisher method, the modified Arrott plot and the critical isotherm analysis agree well. The values deduced for the critical exponents are close to the theoretical prediction from the mean-field model, indicating that the magnetic interactions are long range. On the basis of these critical exponents, the magnetization, field and temperature data around T(C) collapse onto two curves obeying the single scaling equation M(H,ε) = Îµ(ß)f ± (H/ε(ß+γ)).

Improving the solubility of Mn and suppressing the oxygen vacancy density in Zn(0.98)Mn(0.02)O nanocrystals via octylamine treatment.

Zn(0.98)Mn(0.02)O nanocrystals were synthesized by the wet chemical route and were treated with different content of octylamine. The environment around Mn and the defect type and concentration were characterized by photoluminescence, Raman, X-ray photoelectron spectroscopy, and X-ray absorption fine structure. It is found that N codoping effectively enhances the solubility of Mn substituting Zn via reducing donor binding energy of impurity by the orbital hybridization between the N-acceptor and Mn-donor. On the other hand, the O atoms released from MnO(6) and the N ions from octylamine occupy the site of oxygen vacancies and result in reduction of the concentration of oxygen vacancies in Zn(0.98)Mn(0.02)O nanocrystals.

Iron doped hexagonal ErMnO3: structural, magnetic, and dielectric properties.

The single phase ErFe(x)Mn1-xO3 (0 < or = x < or = 0.15) compounds were synthesized by the solid-state reaction method. The doping effects on the crystal structural, magnetic, thermal, and dielectric properties were systematically investigated. The XRD patterns show all samples crystallize in the hexagonal structure with P6(3)cm space group. The lattice parameters a and c first decrease with doping, which is followed by a subsequent increase at higher doping levels. Although both the Fe3+ and Mn3+ ions remain stable in high spin trivalent states in all samples, the magnetization is weakened with increasing Fe contents. The heat capacity data shows the antiferromagnetic transition slightly shifts from 77 K for ErMnO3 to 80 K for ErFe015Mn0.85O3, which can not be observed in the magnetic susceptibility data. The real part of complex impedance of these samples rises as the doping level increases, indicating the enhancement of insulativity of doped samples.

Magnetic phase diagrams based on static and dynamic magnetic behaviour in Ru-based superconducting ferromagnets.

In this work, we present magnetic phase diagrams of a RuSr(2)Eu(1.5)Ce(0.5)Cu(2)O(10-δ) (Ru-1222) superconducting ferromagnet derived from its static and dynamic magnetic responses, measured by temperature and field dependences of dc magnetization and nonlinear ac susceptibility in both low and high magnetic fields. Comparison of magnetic phase diagrams of phase pure and impure samples singles out the intrinsic and extrinsic magnetic features, naturally proposing a unified model of Ru-1222 magnetic behaviour. The results considered within the proposed interpretation indicate full agreement between static and dynamic properties which, if measured in combination, effectively complement each other, uncovering existing ambiguities.

Direct observation of local potassium variation and its correlation to electronic inhomogeneity in (Ba(1-x)K(x))Fe2As2 pnictide.

Local fluctuations in the distribution of dopant atoms are thought to cause the nanoscale electronic disorder or phase separation in pnictide superconductors. Atom probe tomography has enabled the first direct observations of dopant species clustering in a K-doped 122-phase pnictide. First-principles calculations suggest the coexistence of static magnetism and superconductivity on a lattice parameter length scale over a wide range of dopant concentrations. Our results provide evidence for a mixed scenario of phase coexistence and phase separation, depending on local dopant atom distributions.