Cooperative effect of bimetallic MOF-derived CoNi(OH)2@NiCo2S4nanocomposite electrocatalysts with boosted oxygen evolution activity.

Highly efficient and inexpensive electrocatalysts for oxygen evolution reaction (OER) are extensively studied for water splitting. Herein, a unique bimetallic nanocomposite CoNi(OH)2@NiCo2S4nanosheet arrays derived from metal-organic-frameworks (MOFs, CoNi-ZIF) is simply fabricated on Ni foam, endowing large specific surface area and outstanding electrical conductivity. Compared with their single-metallic counterparts, the bimetallic composite displays dramatically low overpotential and small Tafel slope as well as outstanding catalytic stability. The overpoptential at 20 mA cm-2for CoNi(OH)2@NiCo2S4is only 230 mV in comparison with Ni(OH)2@Ni3S2(266 mV), Co(OH)2@Co3S4(294 mV) and RuO2(η = 302 mV). First-principle calculations based on density functional theory (DFT) are carried out and reveal that the introduction of Ni in Co(OH)2helps lowered the energy difference of ΔGOOH*-ΔGO*, and thereby boosting the OER reactivity. This study provides an effective approach for the rational construction of low-cost metal hybrids.

Effect of case management based on Omaha system on clinical symptoms and quality of life of coronary heart disease patients after percutaneous coronary intervention.

To investigate the effect of case management (CM) based on the Omaha system on clinical symptoms and quality of life (QOL) of coronary heart disease patients after percutaneous coronary intervention (PCI). Patients with coronary heart disease after their first PCI in the People's Hospital of Longhua in Shenzhen were randomly divided into a control group (received CM based on the Omaha system) and an observation group (received routine nursing) using a random number table. Nursing problems and the knowledge-behavior-status (KBS) score of patients were evaluated on the day after surgery, on the day before discharge, at 5 weeks after discharge, and at 12 weeks after discharge. The QOL of patients was evaluated using the coronary intervention coronary revascularization outcome questionnaire (CROQ-PTCA-Post, Chinese version) score on the day after surgery and at 12 weeks after discharge. A total of 104 patients completed the study (51 in the control group, 53 in the observation group). There were no significant differences in baseline data between the 2 groups (P gr.05). The main nursing problems were circulation, mental health, and pain in both groups on the day after surgery, whereas they were circulation, sleep and rest, and mental health after nursing. There were no significant differences in the KBS scores of the co-existing nursing problems on the day after surgery (P Th.05). The KBS scores of the co-existing nursing problems were significantly increased between the 2 groups (P < .01) on the day before discharge and at 5 weeks and 12 weeks after discharge. The KBS scores of the most co-existing nursing problems in the observation group were significantly higher at 12 weeks after discharge than at the day before discharge and at 5 weeks after discharge. Moreover, there were no significant differences in the CROQ-PTCA-Post scores on the first day after surgery between the 2 groups (P gr.05). These scores were significantly increased between the 2 groups at 12 weeks after discharge (P < .01). CM based on the Omaha system for patients after PCI can effectively improve the KBS scores and QOL of PCI patients with postoperative nursing problems, making this approach worthy of clinical promotion.

Construction of self-supported hierarchical NiCo-S nanosheet arrays for supercapacitors with ultrahigh specific capacitance.

Transition metal bimetallic sulfides derived from metal-organic frameworks (MOFs) hold great promise for energy-related applications. Here, a facile two-step MOF-engaged strategy is developed to grow ultrathin nickel-cobalt sulfide nanosheet arrays (NiCo-S) on Ni foam with robust adhesion, which provides a large specific surface area and excellent electric conductivity. The optimal self-supported NiCo-S electrode exhibits the best electrochemical performance as a binder-free electrode for supercapacitors with an ultrahigh specific capacitance of 3724 F g-1 at a current density of 1 A g-1 and maintains 1680 F g-1 at 20 A g-1, outperforming recently reported best values based on nickel-cobalt sulfides and oxide/hydroxide counterparts. The results demonstrate that the in situ growth of conductive Ni3S2, the presence of Co(OH)2 and the synergy between bimetals help contribute to the superior capacity. Most importantly, electronic and valence states are carefully investigated to reveal the synergetic effect and it is evidenced that the greatly decreased energy barrier differences between two redox pairs (Ni2+/Ni3+ and Co2+/Co3+) result in higher electrochemical performance. This work might shed light on the origin of high capacitance obtained from bimetallic compound based electrochemical energy storage devices.

[Effects of 6-BA on cluster root formation and organic acid exudation in white lupin grown under phosphorus deficiency].

Phosphorus deficiency results in cluster root formation and increased organic acid exudation. The regulatory mechanisms for these processes, however, are not yet clear. In the present study, influences of 6-BA (6-benzyl aminopurine) on cluster root formation, exudation of citrate and malate and their concentrations in the root clusters of P-deficient white lupin plants were studied by using non-destructive localized collection method and high-performance liquid chromatography (HPLC) technique. The results showed that application of exogenous 6-BA to P-deficient plants did not influence plant growth and P distribution within the plant (Tables 2,3), whereas the cluster root formation (Fig. 1, Table 1) and organic acid exudation (Table 4) were inhibited. The inhibitory effects could be reversed by omitting 6-BA from the growth medium, and even some stimulatory effects was observed, when lower concentration of 6-BA (10(-8) mol/L) was applied (Fig. 1, Tables 1 and 4). The inhibitory effects of higher concentration of 6-BA (10(-7) mol/L) were not reversible. (Table 4). Treatment with 6-BA also had some influence on organic acid concentration in the tissue of cluster roots (Table 5). The possible reasons for the effects on cluster root formation and organic acid exudation by 6-BA are discussed.