We report on the effects of Nb for Sc substitution on the structural and magnetic properties of the Sc1-xNbxFe2 series of compounds by means of scanning electron microscopy, energy dispersive X-ray ...microanalysis, X-ray powder diffraction, and magnetic measurements. The study focus on hexagonal P63/mmc crystal symmetry structure of the ScFe2 phase retained along the series. Whereas the unit cell is found to decrease regularly upon increasing the niobium content the magnetic properties are found to evolve in a non monotonous manner. A drop of the magnetization and Curie temperature is observed upon substitution, the highest TC being 530 K. Indeed, it is shown that Nb for Sc substitution induces dramatic changes of the magnetic properties such as a strong decrease of the ordering temperature and significant reduction of the spontaneous magnetization for Nb content above x=0.2 and 0.1, respectively. The highest magnetization is found for the Sc rich side with values of about 2.6 µB/f.u. corresponding to 1.3 µB/Fe atom. Moreover, compounds with x=0.75 and 1 are no longer exhibiting ferromagnetic order even at 2 K. The easy magnetization direction of Sc1-xNbxFe2 series of compounds is determined to be along the c-axis at room temperature.
•Hexagonal P63/mmc crystal symmetry retained along the series.•Composition dependence of the unit-cell parameters.•Overall volume contraction of ΔV/V = 8.6%.•Evolution of TC and MS upon Nb for Sc substitution.•Easy magnetization direction of ScFe2 is along c-axis.
The French are frequently regarded as grouchy. In a recent study, we observed a high proportion of patients initially consulting for psoriasis because they were dissatisfied with their previous ...therapy. We analyzed the characteristics of these patients.
This was a cross-sectional multicenter study in 40 centers belonging to the ResoPso (psoriasis treatment network) multicenter study group, with consecutive inclusions over a period of 11months in 2014. All adults (age>18 years) consulting for the first time for psoriasis at a center were included in the study.
Among patients, 1205 were included, of whom 249 (20.3%) were consulting because of their dissatisfaction with treatment. In the univariate analysis, these patients were younger (P=0.02) and presented psoriasis that had begun earlier in life (P<0.0001). It consisted mostly of generalized plaque psoriasis (P=0.047) and more severe forms of psoriasis (PASI and/or DLQI score>10, P<0.02). There were fewer cases of psoriatic arthritis (P=0.01). The "dissatisfied" patients reported significantly more frequent use of topical treatments (P<0.0001) and alternative medicines (P=0.02), and more infrequent use of biologics (P=0.006) as well as longer treatment periods (P=0.0005). They consulted at hospitals (P=0.01) and had previously seen more GPs and dermatologists (P≤0.0008). There was no impact of gender on the dissatisfaction profile by either comorbidities (metabolic, blood pressure, alcohol and tobacco consumption, and depression), or socio-economic data. In the multivariate analysis, DLQI>10 (P=0.01; 95% CI: 1.01-1.07) and longer duration of care (P=0.004; 95% CI: 1.23-2.99) were associated with dissatisfaction.
Twenty percent of our psoriatic patients seem dissatisfied with their treatment. It is difficult to draw a specific demographic and socioeconomic profile of dissatisfied patients. Only disease severity and possibly inadequate treatment at the initial consultation are associated with patient dissatisfaction. Explanations related to the individual patients and doctors may be proposed. Finally, while the French may be considered grouchy, the frequency of patient dissatisfaction seen in our study does not appear to be any greater than that observed in other countries.
Plasma and urine glycosaminoglycans (GAGs) are long, linear sulfated polysaccharides that have been proposed as potential noninvasive biomarkers for several diseases. However, owing to the analytical ...complexity associated with the measurement of GAG concentration and disaccharide composition (the so-called GAGome), a reference study of the normal healthy GAGome is currently missing. Here, we prospectively enrolled 308 healthy adults and analyzed their free GAGomes in urine and plasma using a standardized ultra-high-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry method together with comprehensive demographic and blood chemistry biomarker data. Of 25 blood chemistry biomarkers, we mainly observed weak correlations between the free GAGome and creatinine in urine and hemoglobin or erythrocyte counts in plasma. We found a higher free GAGome concentration – but not a more diverse composition - in males. Partitioned by gender, we also established reference intervals for all detectable free GAGome features in urine and plasma. Finally, we carried out a transference analysis in healthy individuals from two distinct geographical sites, including data from the Lifelines Cohort Study, which validated the reference intervals in urine. Our study is the first large-scale determination of normal free GAGomes reference intervals in plasma and urine and represents a critical resource for future physiology and biomarker research.
Mn-Al-C is intended to be one of the "gap magnets" with magnetic performance in-between ferrites and Nd-Fe-B. These magnets are based on the metastable ferromagnetic Formula omitted-phase with L1 ...Formula omitted structure, which requires well controlled synthesis to prevent the formation of secondary phases, detrimental for magnetic properties. Here, we investigate the formation of Formula omitted-phase in Mn-Al-C using Spark Plasma Sintering (SPS) and compare with conventional annealing. The effect of SPS parameters (pressure and electric current) on the phase formation is also studied. Single Formula omitted-phase is obtained for annealing 5 min at Formula omitted with SPS. In addition, we show that the initial grain size of the Formula omitted-phase is influencing the Formula omitted-phase transformation and fraction at a given annealing condition, independently of the annealing method used. A faster transformation was observed for smaller initial Formula omitted-grains. The samples obtained by SPS showed comparable magnetic properties with the conventional annealed ones, reaching coercivity of 0.18 T and saturation magnetization of 114 Am Formula omitted/kg in the optimized samples. The similarity in coercivity is related to the microstructure, as we reveal the presence of structure defects like twin boundaries and dislocations in both materials. Graphical abstract
Grain boundaries in rare earth permanent magnets are of major importance to optimize coercivity and densification during sintering. In this work, grain boundary engineering of Nd-based ThMn12 magnets ...and their nitrides was systematically investigated. First, the parent compound with excess Nd (5, 20 and 40 at%) was studied. It is shown that a paramagnetic dhcp-Nd grain boundary is formed with excess of Nd above 20 at%. This intergranular phase promotes the liquid-phase sintering process at ∼ 700 °C and a bulk nanostructured Nd1.2(Fe,Mo)12 sample with a relative density of 95 % using SPS was obtained. By further doping with Cu, the grain boundary phase properties were tuned by lowering its melting point below 500 °C. Next, the focus is on the nitrides which have a coercivity of ∼ 0.6 T. During the nitrogenation process, the dhcp-Nd grain boundary phase reacts with nitrogen to form a paramagnetic NdN phase, which does not influence coercivity. However, NdN inhibits liquid-phase sintering of the ThMn12 magnets, due to its high melting point (> 1500 °C), limiting the relative density to 65 % after SPS. Thus, a proper grain boundary for nitrides is yet to be found but this work elucidates in detail the specific challenges of grain boundary engineering in Nd-based ThMn12 magnets, non-nitrided and nitrided.
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•Tuning composition leads to a grain boundary allowing liquid sintering and magnetic decoupling.•The grain boundary (GB) can be tuned by adding Cu or Ga which reduces its melting point.•During nitrogenation, the dhcp-Nd GB phase reacts with nitrogen to form NdN phase.•The specific challenges of GB engineering in Nd-based ThMn12 magnets are elucidated.
•A UHPLC-MS/MS kit was used to quantify 17 glycosaminoglycan (GAG) disaccharides.•We validated the kit analytical performance systematically.•We demonstrated acceptable analytical performance in ...native human urine samples.•Intra- and inter-laboratory tests show robust reproducibility of GAG measurements.
Glycosaminoglycans (GAGs) are long linear sulfated polysaccharides implicated in processes linked to disease development such as mucopolysaccharidosis, respiratory failure, cancer, and viral infections, thereby serving as potential biomarkers. A successful clinical translation of GAGs as biomarkers depends on the availability of standardized GAG measurements. However, owing to the analytical complexity associated with the quantification of GAG concentration and structural composition, a standardized method to simultaneously measure multiple GAGs is missing. In this study, we sought to characterize the analytical performance of a ultra-high-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UHPLC-MS/MS)-based kit for the quantification of 17 free GAG disaccharides. The kit showed acceptable linearity, selectivity and specificity, accuracy and precision, and analyte stability in the absolute quantification of 15 disaccharides. In native human samples, here using urine as a reference matrix, the analytical performance of the kit was acceptable for the quantification of CS disaccharides. Intra- and inter-laboratory tests performed in an external laboratory demonstrated robust reproducibility of GAG measurements showing that the kit was acceptably standardized. In conclusion, these results indicated that the UHPLC-MS/MS kit was standardized for the simultaneous measurement of free GAG disaccharides allowing for comparability of measurements and enabling translational research.
The effects of compositional variations and different annealing regimes in Nd(Fe,Ti)12 alloys were studied in terms of phase formation and magnetic properties analysis. NdxFe11Ti (x = 1.05, 1.10, ...1.15, 1.20) alloys were produced by rapid solidification through suction casting technique. The effect of Nd content and post annealing were investigated in the temperature range of 700–1200 °C. Single 1:12 phase samples were obtained at temperatures between 1150 and 1200 °C for compositions with Nd concentration of 1.15 and 1.20. Intrinsic magnetic properties and magnetization reversal were studied for 1:12 single phase samples, revealing uniaxial anisotropy with anisotropy field (HA) of 1.08T and saturation magnetization of 137 Am2kg−1 at room temperature. In addition, the demagnetization mechanism in bulk polycrystalline samples was analyzed by means of Kerr microscopy under applied magnetic fields. Magnetization reversal process starts at the twin boundary, which acts as a nucleation center for the reversal domain, and coupling between adjacent grains is also observed. These may be part of the reasons for the observed low coercivity in the NdFe11Ti systems. The findings of the present study leads to a better understanding of the relation between magnetic properties and microstructure, and can open new strategies to obtain coercivity in this 1:12 phase system and, possibly, in the corresponding nitride.
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Cobalt ferrite (CFO) is a promising candidate for magnetostrictive applications like actuators or sensors. We have recently shown that uniaxial magnetic anisotropy can be induced in CFO by reactive ...sintering using spark plasma sintering (SPS), which leads to an improvement of its magnetostrictive properties. However, the origin of the anisotropy and the formation mechanism remain unexplained so far. In this study, different SPS processes have been conducted to determine which parameter is responsible for the induced uniaxial anisotropy. We demonstrate that the magnetic anisotropy arises during the cooling step when done under SPS’s uniaxial compression. In addition, we also investigate the fundamental origin of the magnetic anisotropy induced during the SPS process. We show that the polycrystalline anisotropic cobalt ferrite obtained after SPS exhibits no texture. However, the SPS samples turn isotropic after being annealed in air at 400 °C/2 h, as shown by magnetic and magnetostrictive measurements. A change in ionic distribution after the annealing is also observed by Mössbauer spectroscopy. Our findings suggest that the induced magnetic anisotropy results from the ionic distribution of the Co2+ in the CFO’s spinel lattice, a mechanism previously observed in magnetic annealed CFO. This study advances the in-depth understanding of the relationship between SPS processing and magnetic properties of cobalt ferrite.
Little is known about how women of childbearing age with psoriasis experience contraception, sexuality and pregnancies through the lens of their skin condition.
To evaluate the experiences and ...expectations in this group of patients.
In total, 235 women aged between 18 and 45 years old completed an online survey. We collected the characteristics of psoriasis, contraception and pregnancy history. Psoriasis severity was measured using the Simplified Psoriasis Index. Patient quality of life was assessed using the Dermatology Life Quality Index (DLQI) and the Short Form-12.
Psoriasis was mild in 78% of cases. The mean DLQI score was 8.8, highlighting a moderate impact of psoriasis. In total, 28% of the women had no current follow-ups, while at least two distinct physicians followed 21% of these patients. In total, 31.5% of the women felt that they could discuss sexuality during their consultations. In addition, 63% of respondents had a contraceptive method, but more than half of the women reported that contraception was rarely or never discussed during the consultations. In total, 63% had at least one pregnancy, and 61.5% reported that the doctor managing their psoriasis did not discuss their pregnancy during consultations. Psoriasis worsened during pregnancy for 21% of the respondents but improved in 34%. Among women who were not pregnant, less than 15% reported that the doctor in charge of their psoriasis discussed family planning and pregnancy possibilities.
Our study shows that the management of women of childbearing age with psoriasis must be improved with respect to sexuality, contraception and pregnancy planning.
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