Interfacial Fe-O-Ni-O-Fe Bonding Regulates the Active Ni Sites of Ni-MOFs via Iron Doping and Decorating with FeOOH for Super-Efficient Oxygen Evolution

The integration of Fe dopant and interfacial FeOOH into Ni-MOFs [Fe-doped-(Ni-MOFs)/FeOOH] to construct Fe-O-Ni-O-Fe bonding is demonstrated and the origin of remarkable electrocatalytic performance of Ni-MOFs is elucidated. X-ray absorption/photoelectron spectroscopy and theoretical calculation results indicate that Fe-O-Ni-O-Fe bonding can facilitate the distorted coordinated structure of the Ni site with a short nickel-oxygen bond and low coordination number, and can promote the redistribution of Ni/Fe charge density to efficiently regulate the adsorption behavior of key intermediates with a near-optimal d-band center. Here the Fe-doped-(Ni-MOFs)/FeOOH with interfacial Fe-O-Ni-O-Fe bonding shows superior catalytic performance for OER with a low overpotential of 210 mV at 15 mA cm^-2 and excellent stability with ≈3 % attenuation after a 120 h cycle test. This study provides a novel strategy to design high-performance Ni/Fe-based electrocatalysts for OER in alkaline media.

Quantification of peak blood flow velocity at the cardiac valve and great thoracic vessels by four-dimensional flow and two-dimensional phase-contrast MRI compared with echocardiography: a systematic review and meta-analysis

AIM

To objectively examine the agreement and correlation between four-dimensional (4D) flow magnetic resonance imaging (MRI) and traditional two-dimensional (2D) phase-contrast (PC) MRI with the reference standard of Doppler echocardiography for measuring peak blood velocity at the cardiac valve and great arteries, and to assess if 4D flow MRI offers an advantage over the traditional 2D method.

MATERIALS AND METHODS

The literature was searched systematically for studies that evaluate the degree of correlation and agreement between 4D flow MRI or 2D PC MRI and Doppler retrieved from PubMed, EMBASE, and the Cochrane Library. A meta-analysis was conducted to determine the peak velocity pooled bias with 95% limits of agreement (LoA) and correlation coefficient (r) for 4D flow MRI and 2D PC MRI compared with Doppler.

RESULTS

Ten studies that compared 4D flow MRI with Doppler and 12 studies that compared 2D PC MRI with Doppler were included. 4D flow MRI showed an underestimation with bias and 95% LoA of -0.09 (-0.41, 0.24) m/s (p=0.079) while 2D PC MRI showed a poorer agreement with a bias and 95% LoA of -0.25 (-0.53, 0.03), p=0.596. 4D flow MRI and 2D PC MRI showed a strong correlation with R=0.80 (95% CI 0.75, 0.84; p<0.001) and R=0.83 (95% CI 0.79, 0.87; p<0.001), respectively.

CONCLUSION

In this meta-analysis, 4D flow MRI provides improved assessment of peak velocity when compared with traditional 2D PC MRI. 4D flow MRI can be considered an important complement or substitute to Doppler echocardiography for peak velocity assessment.

Surface-Adsorbed Carboxylate Ligands on Layered Double Hydroxides/Metal-Organic Frameworks Promote the Electrocatalytic Oxygen Evolution Reaction

Metal-organic frameworks (MOFs) with carboxylate ligands as co-catalysts are very efficient for the oxygen evolution reaction (OER). However, the role of local adsorbed carboxylate ligands around the in-situ-transformed metal (oxy)hydroxides during OER is often overlooked. We reveal the extraordinary role and mechanism of surface-adsorbed carboxylate ligands on bi/trimetallic layered double hydroxides (LDHs)/MOFs for OER electrocatalytic activity enhancement. The results of X-ray photoelectron spectroscopy (XPS), synchrotron X-ray absorption spectroscopy, and density functional theory (DFT) calculations show that the carboxylic groups around metal (oxy)hydroxides can efficiently induce interfacial electron redistribution, facilitate an abundant high-valence state of nickel species with a partially distorted octahedral structure, and optimize the d-band center together with the beneficial Gibbs free energy of the intermediate. Furthermore, the results of in situ Raman and FTIR spectra reveal that the surface-adsorbed carboxylate ligands as Lewis base can promote sluggish OER kinetics by accelerating proton transfer and facilitating adsorption, activation, and dissociation of hydroxyl ions (OH^- ).

Hierarchical porous Ni, Fe-codoped Co-hydroxide arrays derived from metal–organic-frameworks for enhanced oxygen evolution

The multi metal organic frameworks can be successfully transformed into hierarchical porous Ni,Fe-codoped Co-hydroxide nanowire array catalysts with excellent electrocatalytic performance for the OER in alkaline media.

[Identification of mutations associated with coronary artery lesion susceptibility in Kawasaki disease by targeted enrichment of genomic region sequencing technique]

Objective: To screen and identify the mutations in Kawasaki disease by targeted enrichment of genomic region sequencing technique and investigate susceptibility genes associated with coronary artery lesion. Method: This was a case-control study.A total of 114 patients diagnosed as Kawasaki disease treated in Shanghai Children's Hospital between December 2015 and November 2016 were studied and another 45 healthy children who were physically examined in outpatient department were enrolled as control group. Patients were divided into two groups based on the results of echocardiogram. Peripheral venous blood was obtained from patients and controls. Genomic DNA was extracted. SeqCap EZ Choice libraries were prepared by targeted enrichment of genomic region technology. Then the libraries were sequenced to identify susceptibility genes associated with coronary artery lesion in patients diagnosed as Kawasaki disease.Susceptible genes were identified by Burden test, Pearson chi-square test or Fisher's exact probability test. Result: There was statistically significant difference in TNFRSF11B(rs2073618)G>C(p.N3K)mutation and GG/GC/CC genotype between Kawasaki disease group and control group(χ(2)=15.52, P=0.00). There was statistically significant difference in TNFRSF13B(rs34562254)C>T(p.P251L)mutation(χ(2)=10.40, P=0.01)and LEFTY1(rs360057)T>G(p.D322A)mutation(χ(2)=8.505, P=0.01)between patients with coronary artery lesions and those without. Conclusion: Targeted enrichment of genomic region sequencing technology can be used to do primary screening for the susceptible genes associated with coronary artery lesions in Chinese Kawasaki patients and may provide theoretical basis for larger sample investigation of risk prediction score standard in Kawasaki disease.

[Effect of a new ROCK inhibitor thiazovivin on the morphology and function of human corneal endothelial cells]

OBJECTIVE

To evaluate the effect of thiazovivin, a novel ROCK inhibitor, on the morphology and function of human corneal endothelial cells(HCECs).

METHODS

The primary HCECs were identified by light microscopy and immunofluorescence staining of neuron-specific enolase. To screen the optimal concentration and action time of thiazovivin for maintaining the morphology and function of primary HCECs, Na (+)/K (+)-ATPase and N-cadherin were chosen as indicators, and the morphology and function of HCECs in various concentrations(0 μmol/L, 2 μmol/L, 4 μmol/L, and 6 μmol/L)for different durations(24 h and 48 h)were examined by immunofluorescence experiments. The effect of thiazovivin on the expression of ROCK was investigated by immunofluorescence and Western blot.

RESULTS

The primary HCECs cultured were hexagonal, closely packed, homogeneously and obviously stained by neuron-specific enolase. The immunofluorescence staining of Na(+)/K(+)-ATPase showed that when the primary HCECs cultured with various concentrations of thiazovivin(0, 2, 4, 6 μmol/L)for 24 h, the fluorescence were obvious, and the average absorbance values(A)were 1.27±0.08, 3.72±0.17, 21.07±4.67, 3.69±0.34, respectively. And the immunofluorescence staining of N-cadherin revealed that when the primary HCECs treated with 4 μmol/L thiazovivin for 24 h, the cell boundary was clear and the structure of the cells was intact. While the treating time of thiazovivin(4 μmol/L)on HCECs extended to 48 h, the immunofluorescence staining of Na(+)/K(+)-ATPase and N-cadherin showed that compared to HCECs treated with thiazovivin(4 μmol/L)for 24 h, the fluorescence intensity did not change significantly, but the cells arranged slightly untidy. In addition, the immunofluorescence staining of ROCK was weakened and the expression of ROCK was reduced by thiazovivin. Thiazovivin was effective for protecting the morphology and function of HCECs. An optimal improvement in the morphology, connection and function of HCECs was found when the primary HCECs were cultured with 4 μmol/L thiazovivin for 24 h. Moreover, the expression of ROCK protein could be significantly inhibited by thiazovivin. (Chin J Ophthalmol, 2016, 52: 686-692).

Risk assessment of cadmium-contaminated soil on plant DNA damage using RAPD and physiological indices

Impact assessment of contaminants in soil is an important issue in environmental quality study and remediation of contaminated land. A random amplified polymorphic DNA (RAPD) 'fingerprinting' technique was exhibited to detect genotoxin-induced DNA damage of plants from heavy metal contaminated soil. This study compared the effects occurring at molecular and population levels in barley seedlings exposed to cadmium (Cd) contamination in soil. Results indicate that reduction of root growth and increase of total soluble protein level in the root tips of barley seedlings occurred with the ascending Cd concentrations. For the RAPD analyses, nine 10-base pair (bp) random RAPD primers (decamers) with 60-70% GC content were found to produce unique polymorphic band patterns and subsequently were used to produce a total of 129 RAPD fragments of 144-2639 base pair in molecular size in the root tips of control seedlings. Results produced from nine primers indicate that the changes occurring in RAPD profiles of the root tips following Cd treatment included alterations in band intensity as well as gain or loss of bands compared with the control seedlings. New amplified fragments at molecular size from approximately 154 to 2245 bp appeared almost for 10, 20 and 40 mg L(-1) Cd with 9 primers (one-four new polymerase chain reaction, (PCR) products), and the number of missing bands enhanced with the increasing Cd concentration for nine primers. These results suggest that genomic template stability reflecting changes in RAPD profiles were significantly affected and it compared favourably with the traditional indices such as growth and soluble protein level at the above Cd concentrations. The DNA polymorphisms detected by RAPD can be applied as a suitable biomarker assay for detection of the genotoxic effects of Cd stress in soil on plants. As a tool in risk assessment the RAPD assay can be used in characterisation of Cd hazard in soil.

Gender differences and other determinants of the rise in plasma homocysteine after L-methionine loading

The methionine load test is widely used to identify subjects with mild homocysteinemia. We studied factors influencing the rise in plasma homocysteine (tHcy) levels following oral methionine loading, after taking into account determinants of the basal level. The study population comprised 522 persons (mean age 53, range 17 to 95; 63% male; 60% with coronary disease). tHcy was measured fasting and 4 h after administration of L-methionine (dose 4 g/m2). The percentage rise in tHcy was greater in females, at younger ages, and with lower serum creatinine. Basal tHcy was lower in those with high levels of serum folate, red cell folate and serum B12; they also showed a greater percentage rise with loading. After adjustment for age, creatinine and serum vitamins the percent rise was greater in females (mean 230%, S.D. 92) than in males (mean 172%, S.D. 71, P < 0.0001). About 1/4 of this effect was explained by the methionine dose, but important independent gender effects remained. When the results of the loading test were compared with an overall reference range, females were systematically labelled as 'high' but comparison with age and gender-specific reference ranges normalised the sex distribution. Our data show that a single L-methionine loading protocol for both sexes is not appropriate. Gender-specific reference ranges should be used to define post-load homocysteinemia and previous studies which have identified a high proportion of females with this trait probably reflect the need for gender specific reference ranges.

Fasting and post-methionine homocyst(e)ine levels in a healthy Australian population

BACKGROUND

Plasma homocyst(e)ine (H[e]) is frequently measured in patients with occlusive vascular disease, but levels vary between populations and between laboratories.

AIMS

We sought to derive reference values for an Australian population over a wide age range.

METHODS

We measured plasma H(e) in the fasting state and after methionine loading in 116 volunteers selected at random from the Hunter districts of the New South Wales electoral roll and in 49 apparently healthy, active subjects recruited from the region's lawn bowling clubs. Reference ranges were derived for both sexes, in three age strata. We collaborated with two international laboratories in standardising our results.

RESULTS

Mean fasting H(e) levels were approximately 2.7 mumol/L higher in men than women, at all ages (95% CI for the difference, 1.2 to 4.1 mumol/L). Levels increased with age (approximately 1.0 mumol/L/decade, 95% CI 0.5 to 1.5) and were correlated with serum creatine (r = 0.48), serum folate (r = -0.30), red cell folate (r = -0.25) and serum B12 (r = -0.31) (all p < 0.001). These results are similar to those reported in other populations.

CONCLUSIONS

We have defined reference ranges for a typical Australian population, following careful laboratory standardisation. H(e) levels must be interpreted with regard to age, sex, renal function and vitamin B12 and folate status.