•A chemomechanical coupled damage model for fracture behavior inside NCM polycrystalline particles is proposed.•The simulated crack morphology, distribution, and branching are consistent with the ...experiments.•Go-and-wait propagation mode is obtained by calculated damage dissipation energy.•Increasing the C-rates brings two different aggravating effects to the fracture of secondary particles.•The holes and island particles observed in many experiments are captured for the first time.
The degradation of secondary particles caused by intergranular fracture is an important reason for the capacity fading of LiNixCoyMn1-x-yO2 (NCM) polycrystalline electrodes. In this study, a chemomechanical damage model was established to implement a simulation of fracture behavior under different fracture energies, interfacial strengths and C-rates. Cohesive elements were applied along the interfaces of randomly distributed primary particles, generated by the Voronoi algorithm to simulate their separation during lithiation. The damage dissipation energy was calculated to characterize the propagation of cracks. The simulation results showed that the fracture energy and strength between primary particles play an important role in the intergranular fracture behavior. Increasing the C-rates brings two different aggravating effects to the fracture of secondary particles in different cycle stages. The extensive propagation of the main crack suppresses the growth of secondary cracks under a high C-rate or small fracture energy. Island particles and holes that appeared in many experiments after a long-term cycling protocol were simulated for the first time. The evolution of the simulated cracks was consistent with many published experimental images. The method and results are of great significance for understanding the fracture behavior of NCM cathodes.
Body mass index (BMI; in kg/m(2)) values at or above the 75th percentile are associated with increased morbidity and mortality in adulthood, and there are significant correlations between BMI values ...in childhood and in adulthood. The present study addresses the predictive value of childhood BMI for overweight at 35 +/- 5 y, defined as BMI > 28 for men and BMI > 26 for women. Analyses of data from 555 white children showed that overweight at age 35 y could be predicted from BMI at younger ages. The prediction is excellent at age 18 y, good at age 13 y, but only moderate at ages < 13 y. For 18-y-olds with BMIs above the 60th percentile, the probability of overweight at age 35 y is 34% for men and 37% for women. A clinically applicable method is provided to assign an overweight child to a group with a known probability of high BMI values in adulthood.
Summary
Background
Immune thrombocytopenia (ITP) is a common autoimmune bleeding disorder, in which platelet glycoprotein (GP)IIb–IIIa and GPIb–IX are the two most frequently targeted autoantigens. ...Our previous studies in animal models of ITP demonstrated that intravenous immunoglobulin G (IVIG) could protect against anti‐GPIIb–IIIa autoantibody‐mediated thrombocytopenia but failed to ameliorate ITP induced by most anti‐GPIb–IX autoantibodies.
Objectives
The objective of this human study was to evaluate the association between the specificity of antiplatelet autoantibodies and response to IVIG treatment.
Patients/Methods
In this retrospective study, a cohort of 156 previously untreated adults with severe ITP who underwent IVIG therapy (0.4 g kg−1 day−1 for 5 days) was analyzed. The primary outcome was response defined as platelet counts of ≥ 30 × 109 L−1 and a doubling of baseline counts within 7 days of dosing, and an absence of bleeding.
Results and Conclusions
Among the 66 patients with anti‐GPIb–IX autoantibodies, only 24 (36.4%) achieved a response, as compared with 72 of 90 patients (80.0%) who were negative for anti‐GPIb–IX autoantibodies (relative risk 2.2; 95% confidence interval 1.6–3.1). This study found no difference in response between patients with anti‐GPIIb–IIIa autoantibodies (61.7%) and those without anti‐GPIIb–IIIa autoantibodies (61.3%). Logistic regressions, including main effects and the interaction between these two autoantibodies, showed no influence of anti‐GPIIb–IIIa autoantibodies on the effects of anti‐GPIb–IX autoantibodies with regard to their association with IVIG response. Thus, in adults with ITP, the presence of anti‐GPIb–IX autoantibodies is a predictive factor for poor response to IVIG treatment. Trial registration: ClinicalTrials.gov NCT01666795.
Senary Refractory High-Entropy Alloy HfNbTaTiVZr Gao, M. C.; Zhang, B.; Yang, S. ...
Metallurgical and materials transactions. A, Physical metallurgy and materials science,
07/2016, Letnik:
47, Številka:
7
Journal Article
Recenzirano
Odprti dostop
Discovery of new single-phase high-entropy alloys (HEAs) is important to understand HEA formation mechanisms. The present study reports computational design and experimental validation of a senary ...HEA, HfNbTaTiVZr, in a body-centered cubic structure. The phase diagrams and thermodynamic properties of this senary system were modeled using the CALPHAD method. Its atomic structure and diffusion constants were studied using
ab initio
molecular dynamics simulations. The microstructure of the as-cast HfNbTaTiVZr alloy was studied using X-ray diffraction and scanning electron microscopy, and the microsegregation in the as-cast state was found to qualitatively agree with the solidification predictions from CALPHAD. Supported by both simulation and experimental results, the HEA formation rules are discussed.
An accurate, rapid, and sensitive method for the determination of risperidone and 9-hydroxyrisperidone in urine samples was developed by combining water-compatible magnetic molecularly imprinted ...solid-phase extraction with high performance liquid chromatography. Several variables relating to the efficiency of magnetic solid phase extraction were optimized, including the amount of adsorbent, adsorption time, type of elution solvent, and desorption time. The analytical performance of this method was validated under the optimized conditions. The linearity for risperidone and 9-hydroxyrisperidone was obtained in the range 1–2000ngmL−1 with correlation coefficient ≥ 0.991. Limits of detection of risperidone and 9-hydroxyrisperidone are 0.21ngmL−1 and 0.24ngmL−1, respectively. Recoveries at three spike levels (10, 100, and 1000ngmL−1) ranged from 94.6% to 102.4% with relative standard deviations (%) ≤ 5.3. These results confirmed that this method can be successfully and facilely used to analyze the multi-residues of risperidone and 9-hydroxyrisperidone in urine samples with high efficiency and good sensitivity.
Display omitted
•A MMIPs-SPE-HPLC method was developed for risperidone and 9-hydroxyrisperidone detection.•Water-compatible magnetic MIPs were prepared using methacrylic acid and allyl glucose as co-monomers.•MMIPs showed high affinity and selectivity to risperidone and 9-hydroxyrisperidone.
It is vital to improve the rate capability and cycling performance of Sb2S3 to promote its application in lithium-ion batteries. Herein, Sb2S3 is successfully anchored inside a carbon ...nanotube-in-nanotube via a multi-step method based on a metal–organic framework and carbon nanotubes. The composite has a large specific surface area (48.1 m2 g−1), relatively high content of Sb2S3 (57%), and an external highly conductive nitrogen-doped amorphous carbon nanotube. Benefitting from these advanced structure advantages, such as well-confined Sb2S3, completely closed internal void space, highly conductive carbon matrix, and formation of C–S covalent bonds, the composite exhibits superior lithium storage performance. The rate capability is its highlight. Even at 15 A g−1, the discharge capacity still reaches 361 mA h g−1. After the rate test, a cycling test at 5 A g−1 up to 400 cycles demonstrates its excellent structural stability. The cycling performance is very impressive (710.5 mA h g−1 at 1 A g−1 after 1500 cycles, 316 mA h g−1 at 5 A g−1 after 1700 cycles, 201.5 mA h g−1 at 10 A g−1 after 1000 cycles). The reversible capacity is outstanding (1117.2 mA h g−1 at 0.1 A g−1). Electrochemical kinetic analyses and ex situ observation of the cycled composite are studied in detail to comprehensively elucidate its electrochemical mechanism. It can be concluded that carbon nanotube-in-nanotube@Sb2S3 is a promising anode material for high-performance lithium-ion batteries.
A stress assisted diffusion model considering concentration-dependent elastic modulus of active material has been established for the multi-layered electrodes of lithium batteries. The physical ...mechanism for the effect of modulus variation on the Li-ion diffusion and corresponding biaxial stress is well elucidated. Moreover, the analytic solutions of maximum stress in both active layer and collector are respectively derived. It has been found that the modulus stiffening gives rise to the additional stress gradient and enhances Li-ion diffusion, therefore to increase the biaxial stress in the plate electrode. In contrast, modulus softening makes the stress assisted diffusion less significant and the corresponding stresses are reduced. These coupled effects are more significant during potentiostatic charging and galvanostatic charging with high charging rates. Moreover, the maximum stress in the active layer is independent of charging process, but depends upon the elastic modulus variation due to Li-ion insertion. Finally, with increasing thickness ratio between collector and active material, the impacts of concentration dependent modulus on the Li-ion diffusion in active layer decreases, whereas this effect on maximum stress in the current collector increases.
Aim A meta-analysis was performed to evaluate the diagnostic value of magnetic resonance elastography (MRE) in detecting and staging hepatic fibrosis. Materials and methods A systematic search of ...PubMed, EMBASE, Web of Science, and Cochrane Library Database up to October 2013 was undertaken to find studies on the evaluation of MRE in patients suspected of hepatic fibrosis. Data from the articles were analysed using Meta-disc 1.4 and Stata 12.0 software. The sensitivity, specificity, and area under the summary receiver operating characteristic (ROC) curve (AUROC) were pooled for all stages of hepatic fibrosis (F ≥ 1, F ≥ 2, F ≥ 3, and F = 4). Publication bias was assessed through the Deeks' funnel plot asymmetry tests. Results Thirteen studies comprising 989 patients met the inclusion criteria. The pooled sensitivity and specificity for F ≥ 1, F ≥ 2, F ≥ 3, and F = 4 were 0.87 (95% CI = 0.84–0.89) and 0.92 (95% CI = 0.87–0.96), 0.87 (95% CI = 0.84–0.90) and 0.92 (95% CI = 0.89–0.95), 0.88 (95% CI = 0.85–0.91) and 0.91 (95% CI = 0.88–0.93), 0.91 (95% CI = 0.87–0.94) and 0.92 (95% CI = 0.89–0.94), respectively. The pooled AUROC for F ≥ 1, F ≥ 2, F ≥ 3, and F = 4 were 0.9502, 0.9663, 0.9644, and 0.9768, respectively. The non-significant slope of Deeks' funnel plot asymmetry tests indicated that no significant bias was found. Conclusions MRE has a high diagnostic accuracy for the quantitative detection and staging of hepatic fibrosis.
The influence of severe warm-rolling and subsequent annealing on the microstructure and mechanical properties in an AlCoCrFeNi2.1 high entropy alloy consisting of a lamellar arrangement of ordered ...L12 and B2 phases was studied. For this purpose, the as-cast EHEA was severely warm-rolled up to 90% reduction in thickness at selected temperatures of 400 °C, 600 °C, and 750 °C. The severely warm-rolled EHEAs were further annealed at temperatures ranging from 800 °C to 1200 °C for 1 h. Warm-rolling resulted in a unique disordering behavior of the L12 depending on the temperature of warm-rolling. However, the B2 phase maintained the ordered structure irrespective of the warm-rolling temperature. The EHEA warm-rolled at 400 °C and 600 °C showed a predominantly lamellar microstructure, while the EHEA warm-rolled at 750 °C showed a novel heterogeneous microstructure featured by a mixture of lamellar and non-lamellar regions. Annealing of the 90% warm-rolled materials resulted in the formation of predominantly duplex microstructures consisting of disordered FCC and B2 phases. The EHEA warm-rolled at 400 °C and 600 °C showed high strength but rather limited ductility, which could be improved upon annealing. Remarkably, the EHEA warm-rolled at 750 °C showed the most outstanding properties featured by exceptional strength-ductility combination owing to the novel heterogeneous microstructure. Annealing of the heterogeneous EHEA resulted in the deterioration of the strength-ductility balance owing to the annihilation of the heterogeneous microstructure, being replaced by a microduplex structure.
•The AlCoCrFeNi2.1 was severely warm-rolled at different temperatures and annealed.•Unique disordering behavior was observed depending on the rolling temperature.•Novel heterogeneous structure by warm-rolling at 750 °C showed outstanding properties.•Elimination of heterogeneous structure due to annealing resulted in inferior properties.
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