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Isogeometric analysis (IGA) has been widely used as a spatial discretization method for phase field models since the seminal work of Gómez et al. (Comput. Methods Appl. Mech. Engrg. 197(49), pp. 4333–4352, 2008), and the first numerical convergence study of IGA for the Cahn-Hilliard equation was presented by Kästner et al. (J. Comput. Phys. 305(15), pp. 360–371, 2016). However, to the best of our knowledge, the theoretical convergence analysis of IGA for the Cahn-Hilliard equation is still missing in the literature. In this paper, we provide the convergence analysis of IGA for the multi-dimensional Cahn-Hilliard equation for the first time. The two important steps to carry out the convergence analysis are (1) we rigorously prove that the L ∞ norm of IGA solution is uniformly bounded for all mesh sizes, and (2) we construct an appropriate Ritz projection operator for the bi-Laplacian term in the Cahn-Hilliard equation. The first- and second-order stabilized semi-implicit schemes are used to obtain the fully discrete schemes. The energy stability analyses are rigorously proved for the resulting fully discrete schemes. Finally, several two- and three-dimensional numerical examples are presented to verify the theoretical results. [ABSTRACT FROM AUTHOR]

Purpose: Risk stratification based on somatic mutations in TERT promoter and BRAF/RAS has been well established for papillary thyroid cancer (PTC), and there is emerging evidence showed that TERT promoter methylation was frequently observed in thyroid cancer patients with adverse features. This study was aimed to comprehensive explore the prognostic value of BRAF/RAS mutations, TERT promoter mutations, and TERT promoter methylation in PTC. Methods: The relationships of BRAF/RAS mutations, TERT promoter mutations, and TERT promoter methylation with clinical characteristics and outcomes of PTC were analyzed in 382 patients with PTC. Results: TERT promoter mutation and hypermethylation were collectively observed in 52 (13.6%) samples and associated with BRAF/RAS mutation, aggressive clinical characteristics, and poor clinical outcomes of PTC. Coexistence of BRAF/RAS and TERT alterations was found in 45 of 382 (11.8%) PTC patients and strongly associated with old patient age, extrathyroidal extension, advanced pathologic T stage and metastasis. Importantly, patients with both BRAF/RAS and TERT alterations had higher rates of tumor recurrence (13.6% vs 1.5%, P = 0.042) and disease progression (24.4% vs 3.3%, P < 0.001) than patients without any alterations, and cox regression analysis revealed that the coexistence of BRAF/RAS and TERT alterations, but not BRAF/RAS or TERT alterations alone, increased the risk of progression-free interval with an adjusted HR of 10.35 (95% CI: 1.79–59.81, P = 0.009). Conclusions: This study suggested that comprehensively analysis of BRAF/RAS mutations, TERT promoter mutation and methylation is an effective strategy to identify high-risk patients with PTC. [ABSTRACT FROM AUTHOR]

Key message: A stable genomic region conferring FSR resistance at ~250 Mb on chromosome 1 was identified by GWAS. Genomic prediction has the potential to improve FSR resistance. Fusarium stalk rot (FSR) is a global destructive disease in maize; the efficiency of phenotypic selection for improving FSR resistance was low. Novel genomic tools of genome-wide association study (GWAS) and genomic prediction (GP) provide an opportunity for genetic dissection and improving FSR resistance. In this study, GWAS and GP analyses were performed on 562 tropical maize inbred lines consisting of two populations. In total, 15 SNPs significantly associated with FSR resistance were identified across two populations and the combinedPOP consisting of all 562 inbred lines, with the P-values ranging from 1.99 × 10–7 to 8.27 × 10–13, and the phenotypic variance explained (PVE) values ranging from 0.94 to 8.30%. The genetic effects of the 15 favorable alleles ranged from −4.29 to −14.21% of the FSR severity. One stable genomic region at ~ 250 Mb on chromosome 1 was detected across all populations, and the PVE values of the SNPs detected in this region ranged from 2.16 to 5.18%. Prediction accuracies of FSR severity estimated with the genome-wide SNPs were moderate and ranged from 0.29 to 0.51. By incorporating genotype-by-environment interaction, prediction accuracies were improved between 0.36 and 0.55 in different breeding scenarios. Considering both the genome coverage and the threshold of the P-value of SNPs to select a subset of molecular markers further improved the prediction accuracies. These findings extend the knowledge of exploiting genomic tools for genetic dissection and improving FSR resistance in tropical maize. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide is a toxic and hazardous gas that is commonly present in livestock farms, affecting the health of animals and workers. Electrochemical treatment is supposed to be a promising method for H2S control emission. However, this method has a disadvantage in that the product of elemental sulfur causes passivation of the electrode. Herein, hexadecyltrimethylammonium bromide (CTAB), a cationic surfactant, is introduced as an electrolyte additive to inhibition of passivation. The effect of electrolyte additives on the degradation of sulfur ions was investigated using linear sweep voltammetry, chronoamperometry, and electrical impedance spectroscopy. Electrolysis of S2− has been done in a potentiostatic regime at potential 6 V in 0.1 M potassium nitrate-supported electrolyte pH 11.5. The introduction of CTAB resulted in a 53% increase in the degradation of S2− in 3 h. In situ Raman spectrums reveal that CTAB enhances the adsorption of reactant sulfur ions on the Pt electrode, which improves the electron transfer step kinetics due to a combination of ψ 1 effect and the concept of specific adsorption. The proposed electrochemical technology introducing surfactants is promising for wastewater S2− removal. [ABSTRACT FROM AUTHOR]

In a dual-weighted residual method based on the finite element framework, the Galerkin orthogonality is an issue that prevents solving the dual equation in the same space as the one for the primal equation. In the literature, there have been two popular approaches to constructing a new space for the dual problem, i.e., refining mesh grids (h-approach) and raising the order of approximate polynomials (p-approach). In this paper, a novel approach is proposed for the purpose based on the multiple-precision technique, i.e., the construction of the new finite element space is based on the same configuration as the one for the primal equation, except for the precision in calculations. The feasibility of such a new approach is discussed in detail in the paper. In numerical experiments, the proposed approach can be realized conveniently with C++ template. Moreover, the new approach shows remarkable improvements in both efficiency and storage compared with the h-approach and the p-approach. It is worth mentioning that the performance of our approach is comparable with the one through a higher order interpolation (i-approach) in the literature. The combination of these two approaches is believed to further enhance the efficiency of the dual-weighted residual method. [ABSTRACT FROM AUTHOR]

TiO2-based materials are important photocatalysts but the rapid recombination of photoexcited electron–hole pairs, and the wide band gap both limit their photocatalytic activities. In this work, p-type phosphorus-doped graphene quantum dots (P-GQDs, 5~20 nm) were combined with n-type TiO2 nanoparticles (20~50 nm) and n-type silver iodide (AgI, 100~200 nm) by a facile sonication and precipitation process to yield a novel ternary photocatalyst TiO2/P-GQDs/AgI with n-p-n heterojunctions. The morphologies, structures, optical properties, and chemical environments of photocatalysts were all studied. The resulting ternary photocatalyst exhibited enhanced visible photocatalytic activity toward the degradation of methyl orange (MO), estimated to 70.4-fold that of pure TiO2. By contrast, the photocatalytic activities of TiO2/GQDs with an n-n heterojunction, TiO2/P-GQDs with a p-n heterojunction, and TiO2/GQDs/AgI (30%) with an n-n-n heterojunction showed 4.4-fold, 5.3-fold, and 14.2-fold higher than those of TiO2. The electrochemical and optical measurements revealed that the enhanced photocatalytic activity was linked to promoted charge carrier separation by n-p-n heterojunctions coupled with the increased absorption in the visible region. Overall, the new band structure connected in series p-n heterojunctions looks promising as a highly efficient photodegradation system for future use in decontamination of polluted water. [ABSTRACT FROM AUTHOR]

To cure the illness in the brain glioblastoma, the Gliadel wafer, as the first FDA-approved chemotherapy, was available on the market since 1997. Due to the complex studies in vivo, more and more researchers have paid their attention to investigate the dynamic process in the brain by numerical methods. This study aimed to simulate the drug concentration in the cavity after drug releases from Gliadel wafers into the brain tumor by a two-dimensional simulation. The government equations, the parameters, and corresponding initial and boundary conditions are specified. Then the models are discretized and solved by finite element method (FEM) and finite difference method (FDM) based on C++ library Adaptive Finite Element Package (AFEPack) and MATLAB, respectively. First of all, the numerical convergence of the method is studied by numerical results represented in several successively refined meshes, which shows the reliability of our method. In the results from FEM, a steady state of the pressure in the normal tissue can be simulated. As for FDM, the changes of drug concentration are displayed at six different times. The numerical method in this paper is an effective tool for the numerical study on drug release from polymers. Additionally, convection is a critical factor in drug transportation. Moreover, the simulation approach can be used as the guild for remedy optimization and dynamic analysis of other drugs (paclitaxel) for tumor treatment in the clinic. This mathematical model has wide applications about drug release in multiple dosage forms, such as long sustained release microspheres, oral extended release hydrophilic matrix tablets, hydrogel, and sustained release topical rings. [ABSTRACT FROM AUTHOR]

In this work, Ba0.99Ca0.01Zr0.02Ti0.98O3-xLiTaO3 (x = 0, 0.05%, 0.10%, 0.15%, 0.20%, Shorthand for BCZT-xLT) lead-free piezoelectric materials were successfully prepared by high-temperature solid-state reaction method, and the ingredients were calculated according to the theoretical composition of the chemical formula. The effects of LT doping on phase structure, microstructure, dielectric properties, and piezoelectric properties of BCZT-xLT ceramics were studied. The results show that a single perovskite structure is formed after doped LT, and a small amount of LT can improve the piezoelectric and dielectric properties of BCZT. When the doping amount is 0.1%, the Curie temperature is moved to a higher temperature of 129 °C. In addition, the ceramics with x = 0.1% sintered at 1440 °C exhibit enhanced properties of the piezoelectric coefficient (d33 ~ 361 pC/N), planar electromechanical coupling coefficient (kp ~ 40.8%), mechanical figure of merit (Qm ~ 192.4), remnant polarization (Pr ~ 16.6 μC/cm2), and coercive field (Ec ~ 1.3 kV/cm). [ABSTRACT FROM AUTHOR]

Fetal growth restriction (FGR) ranks second among causes of perinatal death. Circular RNA hsa_circ_0074371 (hsa_circ_0074371) is reported to be downregulated in FGR placentae. However, the role and regulatory mechanism of hsa_circ_0074371 in FGR pathogenesis are indistinct. Expression of hsa_circ_0074371, microRNA (miR)-582-3p, and low-density lipoprotein receptor-related protein 6 (LRP6) mRNA in FGR placentae and trophoblast cells (HTR-8/SVneo) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between hsa_circ_0074371 or LRP6 and miR-582-3p was verified by dual-luciferase reporter and/or RNA immunoprecipitation (RIP), RNA pull-down assays. The proliferation, cell cycle progression, apoptosis, migration, and invasion of HTR-8/SVneo cells were evaluated by Cell Counting Kit-8 (CCK-8), flow cytometry, wound healing, or transwell assays. Caspase3 activity was analyzed with a commercial kit. The protein levels of c-myc, cyclinD1, matrix metalloproteinase (MMP) 2, MMP9, and LRP6 were examined by western blotting. We observed that hsa_circ_0074371 and LRP6 were downregulated while miR-582-3p was upregulated in FGR placentae and HTR-8/SVneo cells. Hsa_circ_0074371 modulated LRP6 expression via sponging miR-582-3p. Hsa_circ_0074371 knockdown induced cell cycle arrest, apoptosis, and inhibited cell proliferation, migration, and invasion in HTR-8/SVneo cells. MiR-582-3p inhibitor reversed hsa_circ_0074371 silencing me on proliferation, migration, and invasion of HTR-8/SVneo cells. LRP6 overexpression overturned the inhibitory effect of miR-582-3p mimic on proliferation, migration, and invasion of HTR-8/SVneo cells. In conclusion, hsa_circ_0074371 downregulation inhibited proliferation, migration, and invasion of trophoblast cells via sponging miR-582-3p and decreasing LRP6 expression, providing a new mechanism related to FGR pathogenesis. [ABSTRACT FROM AUTHOR]

A fifth order finite difference alternative weighted essentially non-oscillatory scheme is studied for a five-equation model, which plays an important role in the modelling of compressible multi-component flows. In our algorithm, the primitive variables are used in the weighted essentially non-oscillatory interpolation, from which it can be proved that the equilibriums of the velocity and pressure are preserved respectively throughout the whole computation of contact moving interface problems, under the ideal and stiffened gases equations of state. In addition, it is found that with the interpolation being performed on the characteristic variables which are the projections of the primitive variables, non-physical oscillations appearing around the contact waves can be significantly restrained. Numerical examples verify the theory and illustrate the robustness of the proposed scheme. [ABSTRACT FROM AUTHOR]

Background: The Northeast Plain of China, which is an important region for the production of high grain quality rice in China. However, the grain quality of the rice produced varies across this region, even for the same cultivar. Objective: In order to explore the meteorological factors that have the greatest influence on quality and the transcriptional level differences between different cultivars and different locations at grain filling stage. Methods: We grew eight rice cultivars in three locations in Northeast China during two growing seasons (2017 and 2018). We recorded meteorological conditions, including air temperature, air temperature range, and photosynthetically active radiation (PAR) during the grain-filling stage of each cultivar, and analyzed the grain quality of those eight cultivars. Results: Across all eight cultivars, meteorological factors had a stronger effect on eating quality than genotype, while genotype had a stronger effect on milling quality. Of the three environmental factors assessed, PAR was significantly correlated with the most grain quality traits. Using RNA-sequencing analysis, we identified 573 environment-specific DEGs (Differentially Expressed Genes), and 119 genotype-specific DEGs; 11 DEGs were responsive to genotype × environment interactions. These DEGs were involved in many key metabolic processes. Conclusion: Our results indicated that interactions among environmental factors, especially PAR, affected rice quality in Northeast China. Further analyses of the DEGs identified herein may provide useful information for future breeding programs aiming to develop high grain quality rice varieties suitable for cultivation across Northeast China. [ABSTRACT FROM AUTHOR]

We establish a logarithmic stability estimate for the inverse problem of determining the nonlinear term, appearing in a semilinear boundary value problem, from the corresponding Dirichlet-to-Neumann map. Our result can be seen as a stability inequality for an earlier uniqueness result by Isakov and Sylvester (Commun Pure Appl Math 47:1403–1410, 1994). [ABSTRACT FROM AUTHOR]

High order methods play important roles in the modelling of compressible multi-component flows. However, they may generate negative sound speed, which leads to an instability of the numerical schemes. In this paper, we propose bound- and positivity-preserving limiters for high order finite difference schemes, based on which the equilibriums of the velocity and pressure are preserved throughout the whole computation of contact moving interface problems with the ideal and stiffened equations of state. For illustration purpose, high order alternative WENO scheme is taken for example. Numerical examples verify the theory and demonstrate the robustness of the proposed bound- and positivity-preserving limiters. [ABSTRACT FROM AUTHOR]

Background: Salt stress is a devastating environmental stress that causes plant growth inhibition and yield reduction. Objective: The identification of salt-tolerant genes brings hope for the generation of salinity-tolerant crop plants through molecular breeding. Methods: In this study, one salt-sensitive and one salt-tolerant maize inbred line were screened from 242 maize inbred lines. Reactive oxygen species (ROS)-related enzyme activities were detected and salt-responsive comparative transcriptome analysis was performed for control and 220 mM NaCl treated maize leaves. Results: Salt-tolerant maize inbred line (L87) showed higher ROS-related enzyme (SOD, POD, APX and CAT) activities and accumulated relatively lower levels of ROS under salt stress. Of the total DEGs, 1856 upregulated DEGs were specific to L87, including stress tolerance-related members of the 70kDa family of heat shock proteins (Hsp70s) and aquaporins. The DEGs involved in the abscisic acid (ABA), ethylene, jasmonic acid (JA) and salicylic acid (SA) signal transduction pathways may determine the difference in salt tolerance between the two varieties, especially one central component SnRK2, that positively regulates ABA signaling and was only upregulated in L87. Analysis of DEGs related to ROS scavenging showed that some peroxidase (POD), glutathione S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD) genes specific to L87 probably enhanced its salt tolerance. The analysis of differentially expressed transcription factors (TFs) suggested that WRKY TFs could contribute to the difference in salt tolerance between the two maize lines. Conclusion: Compared with Salt-sensitive maize inbred line (L29), L87 exhibits specific regulatory mechanisms related to salt tolerance, including plant hormone interactions, ROS scavenging and the regulation of TFs. Our study identifies new candidate genes that may regulate maize tolerance to salt stress and provides useful information for breeding maize with high salt resistance. [ABSTRACT FROM AUTHOR]

In Radovitzky and Ortiz (Comput Methods Appl Mech Eng 172(1–4):203–240, 1999), an error estimation technique for nonlinear PDEs is presented to adaptively generating mesh, based on the reduction of the order of the approximate polynomial. In this paper, following a similar analysis framework, we propose an a posteriori error estimation for Kohn–Sham equation by coarsening mesh. An upper bound for the difference of the total energies on two successively refined meshes is derived by the numerical solutions on two meshes through an asymptotic analysis, which finally generates an a posteriori error estimation. A variety of numerical tests show that such an a posteriori error estimation works very well in our h-adaptive finite element method framework. In addition, to further improve the efficiency, we solve a Poisson equation instead of the Kohn–Sham equation on the coarsened mesh. The effectiveness of this improvement is analyzed and numerically examined. [ABSTRACT FROM AUTHOR]

Nanostructured Cu oxides hold great promise as electrode materials for supercapacitors due to their low cost, high theoretical capacitance (1800 F g−1), as well as superior environmental benignity. In this work, hybrid three-dimensional (3D) network and flower-like structure CuO nanoparticles in situ grow on a 3D submicron-porous/solid copper current collector (S/SPCu) via a simple hydrothermal method using H2O2. Benefited from this unique hybrid porous architecture, the as-prepared CuO/S/SPCu electrode shows a high specific capacitance of 445 F g−1 at 2 mA cm−2, high rate capability (60.7% at 64 mA cm−2) and good cycling stability (82.8% capacitance retention after 2000 cycles). The high performance hybrid structure makes the environment-friendly and low-cost CuO/S/SPCu electrode a promising electrode material for supercapacitor applications. [ABSTRACT FROM AUTHOR]

A hybrid titanium chromium nitride nanotube (Ti0.95Cr0.05N NT) support was prepared by a facile synthesis procedure and further used as support for Pt nanoparticles (Pt/Ti0.95Cr0.05N NTs). The catalyst was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and nitrogen absorption/desorption, which show that the Pt/Ti0.95Cr0.05N NTs are formed with homogeneous cohesively attached nitride nanotube crystals. The X-ray photoelectron spectroscopy (XPS) reveals that the interaction between Ti0.95Cr0.05N NTs and Pt nanoparticles is enhanced due to the Cr element doping. Furthermore, the electrochemical experiments demonstrate that Ti0.95Cr0.05N NT-supported Pt catalyst exhibits enhanced catalytic activity and durability for methanol electrooxidation compared with traditional Pt/C catalyst. The experimental dates indicate that the excellent stability and durability of Pt/Ti0.95Cr0.05N NTs toward methanol electrochemical oxidation might be mainly ascribed to the synergistic effect introduced by Cr doping and the tubular nanostructures. The above results indicate that Ti0.95Cr0.05N NTs as support have a promising future in direct methanol fuel cells.Robust non-carbon Ti0.95Cr0.05N nanotubes with tubular structure used as Pt support are synthesized by a facile method, and the Pt/Ti0.95Cr0.05N NT catalyst exhibits much higher activity and stability than conventional JM Pt/C and Pt/TiN NT catalysts for methanol electrooxidation. [ABSTRACT FROM AUTHOR]

In the present study, Pt nanoparticles (20 wt%) were successfully anchored on vanadium (V)-doped titanium nitride hybrid support, which controllable prepared by adjusting the ratio of precursors. Electrochemical performance of the novel Pt/TiVN electrocatalyst exhibits well stability and better electrocatalytic activity than the conventional Pt/C electrocatalyst under direct methanol fuel cells (DMFCs) conditions. Notable, Pt/TiVN exhibits negative onset potential (ca. 0.1 V) and higher current density than Pt/TiN (1.7-fold) and Pt/C (2.5-fold), clearly demonstrating that methanol can be oxidized more easily on Pt/TiVN catalyst. These results indicate that the V doping has co-catalytic and electronic effects, and the hybrid material is indeed a promising support to improve Pt catalytic activity and durability for practical DMFCs. [ABSTRACT FROM AUTHOR]

A titanium silicon nitride nanotubes (TiSiN NTs) support with a one-dimensional (1D) nanostructure is controllable prepared in a controlled manner by adjusting the molar ratio of the precursors, and the TiSiN NTs support is further decorated with Pt nanoparticles to form an electrocatalyst for methanol electrooxidation. Transmission electron microscopy shows that the TiSiN NTs are formed with nanocrystals, and the hollow structure is composed of mesoporous walls. The N adsorption-desorption results reveal that the novel 1D nanotube structure exhibits a large Brunauer-Emmett-Teller surface area, and the XPS patterns demonstrate the strong interaction between the TiSiN NTs support and the Pt nanoparticles. Furthermore, the electrochemical measurements show that the Pt/TiSiN NTs exhibit an enhanced performance and stability compared to the conventional Pt/C catalysts. The dramatically improved durability of the catalyst is confirmed by the accelerated durability test. The combination of facile preparation and remarkable electrochemical performance demonstrates that TiSiN NTs are promising candidates as supports for direct methanol fuel cells. [ABSTRACT FROM AUTHOR]

The concept of scattering coefficients has played a pivotal role in a broad range of inverse scattering and imaging problems in acoustic, and electromagnetic media. In view of their promising applications in inverse problems related to mathematical imaging and elastic cloaking, the notion of elastic scattering coefficients of an inclusion is presented from the perspective of boundary layer potentials and a few properties are discussed. A reconstruction algorithm is developed and analyzed for extracting the elastic scattering coefficients from multi-static response measurements of the scattered field in order to cater to inverse scattering problems. The decay rate, stability and error analyses, and the estimate of maximal resolving order in terms of the signal-to-noise ratio are discussed. Moreover, scattering-coefficients-vanishing structures are designed and their utility for enhancement of nearly elastic cloaking is elucidated. [ABSTRACT FROM AUTHOR]

MicroRNAs play a crucial role in cancer progression and metastasis. miR-203a has been identified as a tumor suppressor in various cancers. However, its functions in renal cell carcinoma have not been illustrated. In this study, we detected the miR-203a expression in renal cell carcinoma and evaluated its association with clinical features. Overexpression of miR-203a was found in renal cell carcinoma tissues and renal cell carcinoma cells. High miR-203a expression is correlated with tumor stage and short overall survival time. Bioinformatics and luciferase assay confirmed that glycogen synthase kinase-3β was a target gene of miR-203a. Silencing of miR-203a could inhibit cell proliferation and migration, arrest them in G1 phase, and promote apoptosis in vitro. miR-203a promotes the progression of renal cell carcinoma and predicts a poor prognosis. [ABSTRACT FROM AUTHOR]

Abstract To investigate hypoglycemic substances from pumpkin, protein-bound polysaccharide was isolated by activity-guided isolation from water soluble substances of the fruits. The protein-bound polysaccharide from pumpkin fruits (PBPP) was identified to consist mainly of polysaccharide (approximately 41.21%) and protein (approximately 10.13%) by anthrone test and Lowry-Folin test. Different doses of PBPP were evaluated for hypoglycemic activity and the effect on serum insulin levels in alloxan diabetic rats. The results indicated that PBPP can obviously increase the levels of serum insulin, reduce the blood glucose levels and improve tolerance of glucose. The hypoglycemic effect of big dose PBPP group (1000 mg/kg body weight) excelled that of small dose PBPP group (500 mg/kg body weight) and antidiabetic agent group. The results suggest that the hypoglycemic effect of PBPP depends on the dose and PBPP possesses the possibility of being developed from a new antidiabetic agent. [ABSTRACT FROM AUTHOR]

Direct electroless nickel plating on n-Si(100) wafers in alkaline solutions was demonstrated without any activation procedure in advance, the effect of pH and temperature of the solutions on size of metal particles in deposits was examined, and also the element contents of deposits were analyzed by energy disperse spectroscopy (EDS). The results indicated that the size of metal particles increases with increasing temperature or decreasing pH. The possible mechanism of nickel deposition on n-Si(100) was discussed in terms of semiconductor electrochemistry, and the formation of nickel seed crystal on Si was mainly attributed to the generation of atomic hydrogen by electron capture of water molecule from the semiconductor in alkaline solutions. [ABSTRACT FROM AUTHOR]

A simple and fast method is described for the extraction of polycyclic aromatic hydrocarbons (PAHs) from complex samples. It is based on the use of a nanoferrofluid modified with a ternary hydrophobic deep eutectic solvent. A predictive model was used for the selection of the optimal eutectic mixture. The entire microextraction only takes a few minutes for completion. Under the optimal extraction conditions (by using menthol, borneol and camphor in a molar ratio of 5:1:4; 80 mg of nanoferrofluid), it offers marked improvements in terms of selectivity and sensitivity. The limits of detection range between 0.31 and 5.9 ng·L−1, and recoveries from spiked samples between 91.3 and 121%. In addition, the strong interactions between PAHs and the extractant were supported by quantum mechanical calculations. This results in a better insight into the microextraction mechanism, providing a fast, environmentally friendly and effective route for the optimization of pretreatment parameters. The method was successfully applied to the determination of the PAHs naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benzo[b]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene and indeno[1,2,3-c,d]pyrene in 12 kinds of coffee samples after different roasting conditions. [ABSTRACT FROM AUTHOR]

The magnetocaloric effect (MCE) is an intrinsic thermal response of all magnetic solids which has a direct and strong correlation with the corresponding magnetic phase transition. It has been well recognized that the magnetic phase transition can be tuned by adjusting applied pressure. Therefore, we perform the high hydrostatic pressure magnetization measurements (up to 1.4 GPa) on a recently reported giant MCE material of TmZn. The results indicate that the Curie temperature of TC increases from 8.4 K at the ambient pressure to 11.5 K under the pressure of 1.4 GPa. The field-induced first order metamagnetic transition is getting weak with increasing pressure, which results in a reduction of MCE. The hydrostatic pressure effect on the magnetic phase transition and MCE in the metamagnetic TmZn is discussed. [ABSTRACT FROM AUTHOR]