Search

Precisely designing atomic metal-nitrogen-carbon (M-N-C) catalysts with asymmetric diatomic configurations and studying their structure–activity relationships for oxygen reduction reaction (ORR) are important for zinc-air batteries (ZABs). Herein, a dual-atomic-site catalyst (DASC) with CoN3S-MnN2S2 configuration was prepared for the cathodes of ZABs. Compared with Co-N-C (Mn-free) and CoMn-N-C (S-free doping), CoMn-N/S-C exhibits excellent half-wave potential (0.883 V) and turnover frequency (1.54 e·s−1·site−1), surpassing most of the reported state-of-the-art Pt-free ORR catalysts. The CoMn-N/S-C-based ZABs achieve extremely high specific capacity (959 mAh·g−1) and good stability (350 h@5 mA·cm−2). Density functional theory (DFT) calculation shows that the introduction of Mn and S can break the electron configuration symmetry of the original Co 3d orbital, lower the d-band center of the Co site, and optimize the desorption behavior of ⋆OH intermediate, thereby increasing the ORR activity. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new run-time monitoring technique to detect hardware Trojan (HT) on working field-programmable gate array (FPGA), which is helpful for reinforcing the hardware security of IoT devices. First, we place multiple temperature sensors on FPGA and collect their value at each time interval. Then, we construct a predictive model which can estimate the distribution of sensor frequency in real-time. If the difference between the predicted value and the real one surpasses a dynamically updated threshold, an HT activation is reported. The experiment results reveal that our technique has high detection accuracy (≥ 98%), low false negative ratio (≤ 1.5%) and zero false positive ratio under various FPGA HT benchmarks. [ABSTRACT FROM AUTHOR]

Electrolytic water splitting (EWS) is an attractive and promising technique for the production of hydrogen energy. Nevertheless, the sluggish kinetic rate of hydrogen/oxygen evolution reactions leads to a high overpotential and low energy efficiency. Up to date, Pt/Ir-based nanocatalysts have become the state-of-the-art EWS catalysts, but disadvantages such as high cost and low earth abundance greatly limit their applications in EWS devices. As an attractive candidate for the Pt/Ir catalysts, series of Ru-based nanomaterials have aroused much attention for their low price, Pt-like hydrogen bond strength, and high EWS activity. In particular, Ru-doped functional porous materials have been becoming one of the most representative EWS catalysts, which can not only achieve the dispersion and adjustment for active Ru sites, but also simultaneously solve the problems of mass transfer and catalytic conversion in EWS. In this review, the design and preparation strategies of Ru-doped functional porous materials toward EWS in recent years are summarized, including Ru-doped metal organic frameworks (MOFs), Ru-doped porous organic polymers (POPs), and their derivatives. Meanwhile, detailed structure–activity relationships induced by the tuned geometric/electronic structures of Ru-doped functional porous materials are further depicted in this review. Last but not least, the challenges and perspectives of Ru-doped functional porous materials catalysts are reasonably proposed to provide fresh ideas for the design of Ru-based EWS catalysts. [ABSTRACT FROM AUTHOR]

Developing an efficient, interface-rich, and free-standing non-noble-metal electrocatalyst is vital for the flexible zinc-air batteries (ZABs). Herein, a three-dimensional (3D) heterogeneous carbon-based flexible membrane was assembled by Co@carbon nanosheets/carbon nanotubes and hollow carbon nanofiber (Co@NS/CNT-CNF) as an efficient oxygen reduction reaction (ORR) catalyst with a positive half-wave potential of 0.846 V and a small Tafel slope of 79 mV·dec−1. Meanwhile, the Co@NS/CNT-CNF electrode also exhibits excellent open-circuit voltage, peak power density, and long-time cycling stability in liquid-state ZABs (1.605 V, 163 mW·cm−2, and 400 h) and flexible ZABs under flat/bending condition (1.47 V, 102 mW·cm−2, and 80 h). Such heterogeneous flexible membrane architecture not only optimizes the electrolyte infiltration, but also provides capacious possibility for O2 and electrolyte transfer. Meanwhile, work-function analyses coupled with density functional theory (DFT) results demonstrate that the electron transfer capability and metal—support interaction can be well optimized in the obtained Co@NS/CNT-CNF catalyst. [ABSTRACT FROM AUTHOR]

Cobalt hydroxide nanosheet is among the most popular oxygen evolution reaction (OER) catalyst yet still suffers from sluggish catalytic kinetics, limited activity, and poor stability. Here, an efficient in situ electrochemical reconstructed CoFe-hydroxides derived OER electrocatalyst was reported. The introduction of Fe promoted the transformation of Co2+ into Co3+ in CoFe-hydroxides nanosheet, along with the formation of abundant amorphous/crystalline interfaces. Thanks for the retained nanosheet microstructure, high valence Co3+ and Fe3+ species, and the amorphous/crystalline heterostructure interfaces, the as-designed electrochemical reconstructed CoFeOOH nanosheet/Ni foam (CoFeOOHNS/NF) electrode delivers 100 mA·cm−2 in alkaline at an overpotential of 275 mV and can stably electrocatalyze water oxidation for at least 35 h at 100 mA·cm−2. Meanwhile, the alkaline full water splitting electrolyzer achieves a current density of 10 mA·cm−2 only at 1.522 V for CoFeOOHNS/NFIIPt/C/NF, which is much lower than that of Ru/C/NFIIPt/C/NF (1.655 V@10 mA·cm−2). This work paves the way for in-situ synergetic modification engineering of electrochemical active components. [ABSTRACT FROM AUTHOR]

Pineapple (Ananas comosus L. Merr) is a tropical plant with economic importance. We aimed to explore the antioxidase and transcriptome changes of pineapple in response to heat stress using cultivars 'Xigua' and 'MD2′. The antioxidase activity of pineapple at different time points under high temperature (38 °C) was measured. The differentially expressed genes (DEGs) of the two pineapple varieties before and after high temperature treatment were screened and used to construct a protein to protein interaction (PPI) network. Subsequently, the expression of genes with high node degree in the PPI network was verified by qRT-PCR. The antioxidant enzyme activities varied in different cultivars with a time-dependent manner under high temperature. Totally 1214 DEGs was identified in 'Xigua' and 261 DEGs were identified in 'MD2′. The enriched GO terms mainly included 'response to hydrogen peroxide' and 'membrane part'. 'nitrogen metabolism' pathway and some secondary substance synthesis pathways were important KEGG pathways. A variety of heat shock proteins (HSPs) was identified to be related to the heat response of pineapple, and most of them showed a significantly high expression level in the high temperature group than that in the normal group. This study laid a certain foundation for the future research on the molecular mechanism of pineapple resistance to high temperature. [ABSTRACT FROM AUTHOR]

An electrochemical non-enzymatic glucose sensor based on copper nanorods (CuNRs) was developed. The CuNRs were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction spectroscopy, and X-ray photoelectron spectroscopy. The results display a layer of rough cuprous oxide that is formed on the surface of CuNRs. The CuNR- modified glassy carbon electrode exhibits an outstanding capability in terms of nonenzymatic sensing of glucose. The sensor displays high sensitivity (1490 μA•mM•cm), fast response time (less than 5 s), a low detection limit of 8 nM (S/ N = 3), long term stability, and excellent anti-fouling ability. The sensor was applied to the detection of glucose in (spiked) human serum and in black ice tea, with relative standard deviations (for n = 6) of 1.7 % and 1.9 %, respectively. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

It is reported that chitinase1 increases in Alzheimer's disease (AD). However, the alteration of chitinase1 in the progress of AD is still unclear. Thus, we designed the present study to detect chitinase1 level in different stages of APP/PS1 double transgenic mice. Experimental models were APP/PS1 double transgenic mice with 4, 12 and 22 months. Cognitive function was detected by Morris water maze test in APP/PS1 mice as well as controls. ELISA and the quantitative RT-PCR were used to detect chitinase1 level in different groups. The study displayed that expression of chitinase1 gradually increased in a time-dependent manner in APP/PS1 mice, while there were no statistical differences among the wild-type mice in varies ages. Moreover, chitnase1 increased significantly in APP/PS1 mice aged 12 and 22 months compared with the age matched wild-type group, respectively. However, no difference of chitnase1 was found between 4 months-old APP/PS1 mice and wild-type mice. Comparing with the age matched wild type group, the consequences of mRNA on the increase in chitnase1 is in accordance with protein in APP/PS1 mice. Furthermore, Morris water maze showed that 4 months-old APP/PS1 mice have normal spatial learning and impaired spatial memory; both spatial learning and spatial memory in 12 and 22 months-old APP/PS1 mice were declined. Time-dependent increase of chitnase1 in APP/PS1 double transgenic mice indicates that the level of chitinase1 is associated with decline of cognition. Therefore, chitinase1 might be a biomarker of disease progression in AD. [ABSTRACT FROM AUTHOR]

Public hospitals are the most important components of health systems and account for a large proportion of health resources in China. However, few researches on the efficiency assessment of public hospitals have been conducted in Tianjin, China. On the basis of the data of annual health service report in 2013 from the Ministry of Health, we measured the relative efficiency of the tertiary general public hospitals in Tianjin and estimated the magnitudes of output increase and/or input reduction by using data envelopment analysis to improve hospital efficiency. The main findings of this study indicate that more than half of the sample hospitals operate at a technical and scale efficiency, and the prevalent scale inefficiency is increasing returns to scale. Moreover, it is a prominent issue that health resource constraint and resource waste coexist. Health policy-makers and hospital administrators would need to address these problems by taking comprehensive measures such as optimizing the allocation of health resources, implementing hierarchical diagnosis and treatment, as well as innovating medical-service operating mechanism of public hospital to improve the people's wellbeing. [ABSTRACT FROM AUTHOR]

Emerging data suggests that mitochondrial dysfunction is prominently involved in Alzheimer disease (AD) progression. Sirtuin-3 (Sirt3) is a member of the sirtuin family of nicotinamide adenine dinucleotide dependent deacetylases that regulates a variety of mitochondrial functions and suppresses mitochondria-related physiology. Here, we determined sirt3 expression in a mouse model of AD. Spatial learning and memory were tested by Morris water maze in APP/PS1 double transgenic mice. The expression of sirt3 was assayed by real-time quantitative PCR and western blotting. Age-and gender-matched wild-type (WT) littermates were used as controls. Cortical sirt3 localization was assessed using immunohistochemistry. The expression of sirt3 mRNA was significantly lower in the cortex of APP/PS1 double transgenic mice than in WT littermates (0.83 ± 0.24 vs. 1.10 ± 0.21, P < 0.05). A comparable reduction was found in sirt3 protein levels using western blotting. The ratio of mean optical density (MOD) of total sirt3/β-actin in the cortex was 0.77 ± 0.11 in APP/PS1 double transgenic mice and 1.34 ± 0.17 in the WT littermates ( P < 0.01). Immunohistochemistry showed the same change as western blotting. The ratio of MOD of integral optical density/total area in APP/PS1 and WT littermates was 0.58 ± 0.02 and 0.71 ± 0.05 ( P < 0.01). These data show that sirt3 was depleted in APP/PS1 double transgenic mice. The results suggest that mitochondrial sirt3 might participate in the development of AD via mitochondrial dysfunction. [ABSTRACT FROM AUTHOR]

Transforming growth factor beta (TGFβ) signaling participates in pathogenesis of epilepsy. TGFβ1, as a transmitter of TGFβ signaling, might be a useful marker for predicting the prognosis of patients with epilepsy. The present study aimed to measure TGFβ1 level in the cerebrospinal fluid (CSF) of patients with drug-resistant epilepsy and non-resistant epilepsy. A total of 43 patients with epilepsy were recruited, 28 were non-resistant epilepsy subgroup, 15 drug-resistant epilepsy subgroup. 11 patients with intracranial infection and 11 individuals with primary headache were used as controls. The concentration of CSF and serum TGFβ1 was measured by enzyme-linked immunosorbent assay. The concentration of CSF-TGFβ1 was 209.26 ± 81.07 pg/ml in the drug-resistant epilepsy subgroup, 121.80 ± 40.32 pg/ml in the non-resistant epilepsy subgroup, 552.17 ± 456.20 pg/ml in intracranial infection control, 133.80 ± 68.55 pg/ml in headache control, respectively. TGFβ1 level was significantly increased in the drug-resistant epilepsy subgroup compared to the non-resistant epilepsy subgroup. TGFβ1 level in intracranial infection control was higher than that in the non-resistant epilepsy subgroup. There was no statistically difference of CSF-TGFβ1 between the non-resistant epilepsy subgroup and headache controls, between the resistant epilepsy subgroup and intracranial infection controls. TGFβ levels are increased in the CSF of patients with drug-resistant epilepsy. High CSF-TGFβ1 levels may be a potential screening biomarker of antiepileptic drug resistance in patients with epilepsy. [ABSTRACT FROM AUTHOR]

A glassy carbon electrode was modified with PdO-NiO composite nanofibers (PdO-NiO-NFs) and applied to the electrocatalytic reduction of hydrogen peroxide (HO). The PdO-NiO-NFs were synthesized by electrospinning and subsequent thermal treatment, and then characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Factors such as the composition and fraction of nanofibers, and of the applied potential were also studied. The sensor exhibits high sensitivity for HO (583.43 μA · mM · cm), a wide linear range (from 5.0 μM to 19 mM), a low detection limit (2.94 μM at an SNR of 3), good long term stability, and is resistant to fouling. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA), which is marked by inflammatory synovitis, is a common, chronic autoimmune-disease, whose pathogenesis is complex and still unclear. In order to explore the effects of heat and hyposmotic stimuli on synoviocytes in rheumatoid arthritis, the changes of [Ca2+i induced by heat, hyposmotic and 4α-PDD stimuli were observed in synoviocytes. [Ca2+i elevation induced by heat ⩾ 28°C, hyposmotic and 4α-PDD stimuli is found to be positively relative to increasing temperature, decreasing osmolality and rising concentration of 4α-PDD. Results show that there is reciprocity among these stimuli and desensitization, and that [Ca2+]i elevation depends on Ca2+ influx, but not necessarily links to Ca2+ release from intracellular stores and voltage-dependent Ca2+ channel in synoviocytes. The above characteristics of Ca2+ influx are similar to those of TRPV4. A probable mechanism has been suggested that heat and hyposmotic stimulation might increase the level of [Ca2+]i by activating the TRPV4-like channel and Ca2+ influx in the synoviocytes. [ABSTRACT FROM AUTHOR]