Coexistence of Superhardness and Metal-Like Electrical Conductivity in High-Entropy Dodecaboride Composite with Atomic-Scale Interlocks.

High electrical conductivity and super high hardness are two sought-after material properties, but both are contradictory because the effective suppression of dislocation movement generally increases the scattering of conducting electrons. Here we synthesized a high-entropy dodecaboride composite (HEDC) with a large number of atomic-scale interlocking layers. It shows a Vickers hardness of 51.2 ± 3.6 GPa under an applied load of 0.49 N and an electrical resistivity of 44.5 µΩ·cm at room temperature. Such HEDC achieves superhardness by inheriting the high intrinsic hardness of its constituent phases and restricting the dislocation motion to further enhance the extrinsic hardness through forming numerous atom-scale interlocks between different slip systems. Moreover, the HEDC maintains the excellent electrical conductivity of the constituent borides, and the competition between two correlating structures produces the special kind of coherent boundary that minimizes the scattering of conducting electrons and does not largely deteriorate the electrical conductivity.

Preparation of Hierarchical Porous Silicon Carbide Monoliths via Ambient Pressure Drying Sol-Gel Process Followed by High-Temperature Pyrolysis.

Hierarchical porous silicon carbide (SiC) attracts great attention due to its superior chemical resistance, high thermal shock resistance, and excellent thermal stability. The preparation of a porous SiC monolith via a simple sol-gel method is limited by either the high cost of the raw materials or the special time-consuming drying process. Herein, we report an ambient drying sol-gel approach for the synthesis of organic-inorganic hybrid monolithic gels which can be converted into hierarchical porous SiC monoliths upon pyrolysis at 1400 °C. The as-synthesized SiC monoliths possess hierarchical pores with macropores of 4.5 µm and mesopores of 2.0 nm. The porosities, specific surface areas and compressive strengths of the hierarchical porous SiC monoliths are 71.3%, 171.5 m2/g and 7.0 ± 0.8 MPa, respectively.

Renal Arteriography via Radial Artery Access with a 125 cm Long Angiographic Catheter.

A 125 cm long catheter makes it possible to perform renal arteriography via radial artery, but its feasibility and safety remain unclear. Our study recruited 1,323 patients grouped by two different vascular accesses to renal arteriography, i.e., femoral artery access and radial artery access. The success rate of angiography was 100% in both groups. Differential analysis showed that the overall complication incidence of radial artery access group was significantly lower (2.5% for radial artery access vs. 4.8% for femoral artery access, p = 0.03). From this study, we suggest that using the 125 cm angiographic catheter to perform renal arteriography via radial artery access is feasible and safe.

High-entropy A2B2O7-type oxide ceramics: A potential immobilising matrix for high-level radioactive waste.

The sustainable development of civil nuclear energy requires the fabrication of the durable nuclear wasteforms, in particular for high-level radioactive waste, which involves the design of the composition and microstructure. Herein, we demonstrated that high-entropy ceramics (Eu1-xGdx)2(Ti0.2Zr0.2Hf0.2Nb0.2Ce0.2)2O7 are the potential candidate as immobilizing hosts for high-level radioactive waste. The static aqueous leaching test indicates that the normalized leaching rates for the simulated radionuclides Ce (LRCe) and Gd (LRGd) in as-prepared high-entropy ceramics are approximately 10-6~10-8 g·m-2·d-1 after 42 days testing, much lower than those reported values in doped-Gd2Zr2O7 (10-6~10-3 g·m-2·d-1). The excellent chemical durability is mainly due to the synergistic effects of the compositional complexity and severe lattice distortion. Compared to their ternary oxides, the low oxygen vacancy concentration slows down the migration and diffusion of cations. Moreover, the lattice distortion increases the lattice potential energy, also inhibiting the migration of cations. This study provides a strategy for the development and application of high-entropy ceramics as the wasteforms.

Enhanced Hardness in Transition-Metal Monocarbides via Optimal Occupancy of Bonding Orbitals.

An efficient strategy that can guide the synthesis of materials with superior mechanical properties is important for advanced material/device design. Here, we report a feasible way to enhance hardness in transition-metal monocarbides (TMCs) by optimally filling the bonding orbitals of valence electrons. We demonstrate that the intrinsic hardness of the NaCl- and WC-type TMCs maximizes at valence electron concentrations of about 9 and 10.25 electrons per cell, respectively; any deviation from such optimal values will reduce the hardness. Using the spark plasma sintering technique, a number of W1-xRexC (x = 0-0.5) have been successfully synthesized, and powder X-ray diffractions show that they adopt the hexagonal WC-type structure. Subsequent nanoindentation and Vickers hardness measurements corroborate that the newly developed W1-xRexC samples (x = 0.1-0.3) are much harder than their parent phase (i.e., WC), marking them as the hardest TMCs for practical applications. Furthermore, the hardness enhancement can be well rationalized by the balanced occupancy of bonding and antibonding states. Our findings not only elucidate the unique hardening mechanism in a large class of TMCs but also offer a guide for the design of other hard and superhard compounds such as borides and nitrides.

A Case-Control Study of the Association of the Polymorphisms of MTHFR and APOE with Risk Factors and the Severity of Coronary Artery Disease.

OBJECTIVES: To explore the association between single-nucleotide polymorphisms (SNPs) in MTHFR and APOE and the risk of CAD and, more importantly, the severity of CAD and the profile of serum lipids, we performed a case-control study in a Chinese Han population. METHODS: A total of 1,207 cases of consecutive CAD-suspected inpatients were recruited, and 406 CAD cases and 231 non-CAD controls were enrolled for the final analysis after screening for exclusion criteria. All subjects had undergone coronary angiography, and the severity of CAD was evaluated by 2 cardiologists according to the Gensini scores. The genotypes of MTHFR and APOEwere detected using real-time PCR, and then verified by Sanger sequencing. Environmental risk factors, such as age, sex, smoking, alcohol consumption, hypertension, diabetes, dyslipidemia, and BMI were collected. Statistical analyses (the χ2 test, binary logistic regression analysis, and ordinal polytomous logistic regression analysis) were performed with SPSS v16.0. RESULTS: The genotypes ofall the subjects included in the CAD and non-CAD groups in this study were successfully detected, with an agreement of 100% with Sanger sequencing. The distributions of genotypes CT and TT at MTHFR C667T were higher in CAD cases than in non-CAD controls (OR 1.99, 95% CI 1.34-2.95; OR 1.77, 95% CI 1.18-2.67; p < 0.05), whereas genotype AC at MTHFR A1298Cwas lower in CAD cases (OR 0.71, 95% CI 0.50-1.02; p < 0.05). A significant association was observed in genotypes CT and TT at MTHFR C667T and the risk of CAD (OR 1.44, 95% CI 1.27-3.67; OR 1.56, 95% CI 0.88-2.78; p < 0.05). Both genotypes and alleles of APOE were comparable in the CAD cases and non-CAD controls (p > 0.05). The genotype TT at MTHFR C667T and ε4+ at APOE were more likely to be found in the CAD subgroup with a Gensini score ≥72 (p = 0.040 and p = 0.028, respectively). Meanwhile, in the patients with genotype TT,a higher level of serum Hcy was detected, while genotype ε4+ patients possessed higher levels of serum apolipoprotein E (ApoE) and low-density lipoprotein cholesterol (LDL-C) than other genotypes. CONCLUSION: This study revealed that the SNP site of MTHFR C667Tis associatedwith the risk of CAD in this Chinese Han population. In addition, the genotypes of TT in MTHFR C667T and ε4+in APOE may increase the severity of CAD, and higher Hcy, LDL-C, and ApoE levels may be involved in this pathogenic process.

Assessing inflammation in Chinese subjects with subtypes of heart failure: an observational study of the Chinese PLA Hospital Heart Failure Registry.

BACKGROUND: Inflammation is an important element of the pathophysiological process of heart failure (HF) and is correlated with subtypes of HF. The association between multiple biomarkers of inflammation and HF subtypes in Chinese subjects remains unclear. This study aimed to compare the differences in inflammation biomarkers among Chinese patients with different subtypes of HF who have been identified to date. METHODS: We included 413 consecutive patients with HF, including 262 with preserved ejection fraction (HFpEF), 55 with middle-ranged ejection fraction (HFmrEF) and 96 with reduced ejection fraction (HFrEF). Ten inflammation biomarkers were analyzed and compared according to the HF subtypes. One hundred contemporary non-HF subjects were also recruited as the control group. Moreover, the correlations between the inflammatory biomarkers and left ventricular ejection fraction of the HF subtypes were assessed. RESULTS: The mean age of the HF patients was 65.0 ± 12.0 years, 65.8% were male. Distinct subtypes of HF demonstrated different inflammation biomarker panels. IL-6, PTX-3, ANGPTL-4 and TNF-α were correlated with HFrEF; IL-1ß and PTX-3 were correlated with HFmrEF; and IL-1ß and IL-6 were correlated with HFpEF. The multivariable logistic regression showed that IL-1ß [relative ratio (RR) = 1.08, 95% CI: 1.02-1.15, P = 0.010], IL-6 (RR = 1.03, 95% CI: 1.01-1.06, P = 0.016), PTX-3 (RR = 1.31, 95% CI: 1.11-1.55, P = 0.001), and ANGPTL-4 (RR = 1.05, 95% CI: 1.02-1.07, P < 0.001) were independently associated with HF, while IL-6 (RR = 1.03, 95% CI: 1.01-1.04, P = 0.019), PTX-3 (RR = 1.23, 95% CI: 1.06-1.43, P = 0.007), and ANGPTL-4 (RR = 1.03, 95% CI: 1.01-1.06, P = 0.005) were independently associated with the HF subtype. CONCLUSIONS: Diverse inflammation biomarkers have multifaceted presentations according to the subtype of HF, which may illustrate the diverse mechanisms of inflammation in Chinese HF patients. IL-6, PTX-3, and ANGPTL-4 were independent inflammation factors associated with HFrEF and HF.

Repeated measurement of growth-differentiation factor-15 in Chinese Han patients with post-myocardial infarction chronic heart failure.

BACKGROUND: Growth-differentiation factor-15 (GDF-15) is a promising prognostic biomarker in patients with chronic heart failure (CHF). Comparatively little is known about the value of repeated measurement of GDF-15 with CHF in Chinese Han population. This study sought to identify the clinical value of repeated measurement of GDF-15 in Chinese Han patients with post-myocardial infarction CHF. METHODS: In total, 232 consecutive Chinese Han patients with post-myocardial infarction CHF were enrolled prospectively from January 2014 to June 2016.The plasma concentration of GDF-15 was determined on admission and over 12 months. Patients were followed up for all-cause death and a composite outcome of major adverse cardiac events (MACE) included all-cause death, myocardial infarction and first heart failure (HF) re-hospitalization. Association with other clinical variables and adverse outcomes of repeated measurement of GDF-15 was explored. RESULTS: The median baseline GDF-15 level was 2025 ng/L. Baseline GDF-15 was moderately associated with baseline N-terminal pro-B type natriuretic peptide (NT-proBNP) (coefficient 0.561, P < 0.001). During a median follow-up of 20 months, there were 53 deaths and 100MACE. GDF-15 remained an independent predictor of all-cause death (adjusted hazard ratio 1.826 per 1 Ln U, 95% CI: 1.037-8.360; P = 0.037) and MACE (adjusted hazard ratio 2.243 per 1 Ln U, 95% CI: 1.181-1.775; P < 0.001) adjusted for established risk factors. Repeated measurement of GDF-15 was performed in 173 survivals over 12months. Increase of GDF-15 over 12 months was associated with dilatation of left ventricle and acted as an independent predictor of subsequent all-cause death (adjusted HR = 3.164, 95% CI: 1.245-0.041; P = 0.015). In the joint model, GDF-15 was also shown to be a risk factor for all-cause death (HR = 2.749, 95% CI: 1.667-3.831; P < 0.001) and MACE (HR = 2.434, 95% CI: 1.425-3.443; P < 0.001). CONCLUSIONS: Repeated measurements of GDF-15 have promising prognostic value of the risk of all-cause death in Chinese Han patients with CHF post-myocardial infarction. GDF-15 may influence the post-myocardial infarction CHF through the path physiological pathway of myocardial remodeling.

[Effects of Long-term Organic Amendments on Soil N2 O Emissions from Winter Wheat-maize Cropping Systems in the Guanzhong Plain].

The primary aim of this study was to quantify the effects of long-term organic amendments on soil nitrous oxide (N2O) emissions. Using static chamber-gas chromatograph technique, we measured N2O fluxes from winter wheat-maize rotation system and related environmental factors in the Guanzhong Plain for one year (October 2014 to October 2015). Field experiments were based on the "Chinese National Loess Fertility and Fertilizer Effects Long-term Monitoring Experiment". Four treatments were control (CK, 0 kg·hm-2), NPK (NPK, 353 kg·hm-2), NPK combined with maize straw[NPKS, (353+40) kg·hm-2] and cattle waste[NPKM, (238+115) kg·hm-2]. During the experimental period, N2O fluxes from CK treatment were small[<2.9 g·(hm2·d)-1]; while emissions from fertilized treatments peaked after fertilization[up to 113.4 g·(hm2·d)-1 for NPKS] and irrigation[up to 495.0 g·(hm2·d)-1 for NPKM] during winter wheat and maize seasons, respectively. N2O flux was significantly correlated to soil water-filled pore space for all treatments (r>0.28,P<0.05). Annual N2O emissions were (0.1±0.0), (2.6±0.1), (3.4±0.7) and (2.9±0.3) kg·hm-2 for CK, NPK, NPKS and NPKM, respectively. The fertilized treatments released higher N2O emissions than CK treatment (P<0.05), indicating that fertilization stimulated N2O emissions. However, the differences in N2O emissions were not significant among the fertilized treatments (P=0.06), suggesting that organic amendments did not increase N2O emissions obviously. The direct emission factors were 0.72%, 0.83% and 0.80% for NPK, NPKS and NPKM, respectively, all of which were lower than the IPCC default of 1%. The yield-scaled N2O emission for NPKM was the lowest among the fertilized treatments.

An age-structured two-strain epidemic model with super-infection.

This article focuses on the study of an age-structured two-strain model with super-infection. The explicit expression of basic reproduction numbers and the invasion reproduction numbers corresponding to strain one and strain two are obtained. It is shown that the infection-free steady state is globally stable if the basic reproductive number R(0) is below one. Existence of strain one and strain two exclusive equilibria is established. Conditions for local stability or instability of the exclusive equilibria of the strain one and strain two are established. Existence of coexistence equilibrium is also obtained under the condition that both invasion reproduction numbers are larger than one.