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1.
Plant J ; 114(3): 570-590, 2023 05.
Article in English | MEDLINE | ID: mdl-36815286

ABSTRACT

Leaf senescence involves massive multidimensional alterations, such as nutrient redistribution, and is closely related to crop yield and quality. No apical meristem, Arabidopsis transcription activation factor, and Cup-shaped cotyledon (NAC)-type transcription factors integrate various signals and modulate an enormous number of target genes to ensure the appropriate progression of leaf senescence. However, few leaf senescence-related NACs have been functionally characterized in wheat. Based on our previous RNA-sequencing (RNA-seq) data, we focused on a NAC family member, TaNAC69-B, which is increasingly expressed during leaf senescence in wheat. Overexpression of TaNAC69-B led to precocious leaf senescence in wheat and Arabidopsis, and affected several agricultural traits in transgenic wheat. Moreover, impaired expression of TaNAC69-B by virus-induced gene silencing retarded the leaf senescence in wheat. By RNA-seq and quantitative real-time polymerase chain reaction analysis, we confirmed that some abscisic acid (ABA) biosynthesis genes, including AAO3 and its ortholog in wheat, TraesCS2B02G270600 (TaAO3-B), were elevated by the overexpression of TaNAC69-B. Consistently, we observed more severe ABA-induced leaf senescence in TaNAC69-B-OE wheat and Arabidopsis plants. Furthermore, we determined that TaNAC69-B bound to the NAC binding site core (CGT) on the promoter regions of AAO3 and TaAO3-B. Moreover, we confirmed elevated ABA levels in TaNAC69-B-OE wheat lines. Although TaNAC69-B shares 39.83% identity (amino acid) with AtNAP, TaNAC69-B did not completely restore the delayed leaf senescence in the atnap mutant. Collectively, our results revealed a positive feedback loop, consisting of TaNAC69-B, ABA biosynthesis and leaf senescence, that is essential for the regulation of leaf senescence in wheat.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Arabidopsis/genetics , Arabidopsis/metabolism , Triticum/metabolism , Plant Senescence , Transcription Factors/genetics , Transcription Factors/metabolism , Arabidopsis Proteins/metabolism , Gene Expression Regulation, Plant , Plant Leaves/genetics , Plant Leaves/metabolism , Abscisic Acid/metabolism
2.
J Am Chem Soc ; 145(5): 3108-3120, 2023 02 08.
Article in English | MEDLINE | ID: mdl-36700857

ABSTRACT

Nicotinamide adenine dinucleotide (NAD) is a critical regulator of metabolic networks, and declining levels of its oxidized form, NAD+, are closely associated with numerous diseases. While supplementing cells with precursors needed for NAD+ synthesis has shown poor efficacy in combatting NAD+ decline, an alternative strategy is the development of synthetic materials that catalyze the oxidation of NADH into NAD+, thereby taking over the natural role of the NADH oxidase (NOX) present in bacteria. Herein, we discovered that metal-nitrogen-doped graphene (MNGR) materials can catalyze the oxidation of NADH into NAD+. Among MNGR materials with different transition metals, Fe-, Co-, and Cu-NGR displayed strong catalytic activity combined with >80% conversion of NADH into NAD+, similar specificity to NOX for abstracting hydrogen from the pyridine ring of nicotinamide, and higher selectivity than 51 other nanomaterials. The NOX-like activity of FeNGR functioned well in diverse cell lines. As a proof of concept of the in vivo application, we showed that FeNGR could specifically target the liver and remedy the metabolic flux anomaly in obesity mice with NAD+-deficient cells. Overall, our study provides a distinct insight for exploration of drug candidates by design of synthetic materials to mimic the functions of unique enzymes (e.g., NOX) in bacteria.


Subject(s)
Graphite , NAD , Mice , Animals , NAD/metabolism , Oxidation-Reduction , Mammals/metabolism , Bacteria/metabolism , Dietary Supplements
3.
Crit Rev Food Sci Nutr ; 63(25): 7341-7356, 2023.
Article in English | MEDLINE | ID: mdl-35229702

ABSTRACT

Pesticides residues in foodstuffs are longstanding of great concern to consumers and governments, thus reliable evaluation techniques for these residues are necessary to ensure food safety. Emerging ambient ionization mass spectrometry (AIMS), a transformative technology in the field of analytical chemistry, is becoming a promising and solid evaluation technology due to its advantages of direct, real-time and in-situ ionization on samples without complex pretreatments. To provide useful guidance on the evaluation techniques in the field of food safety, we offered a comprehensive review on the AIMS technology and introduced their novel applications for the analysis of residual pesticides in foodstuffs under different testing scenarios (i.e., quantitative, screening, imaging, high-throughput detection and rapid on-site analysis). Meanwhile, the creative combination of AIMS with high-resolution mass analyzer (e.g., orbitrap and time-of-flight) was fundamentally mentioned based on recent studies about the detection and evaluation of multi-residual pesticides between 2015 and 2021. Finally, the technical challenges and prospects associated with AIMS operation in food industry were discussed.


Subject(s)
Pesticide Residues , Pesticides , Pesticides/analysis , Radar , Mass Spectrometry/methods , Pesticide Residues/analysis , Food Safety
4.
Pestic Biochem Physiol ; 197: 105688, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38072543

ABSTRACT

Difenoconazole (DFN) is widely utilized as a fungicide in wheat production. However, its accumulation in plant tissues has a profound impact on the physiological functions of wheat plants, thus severely threatening wheat growth and even jeopardizing human health. This study aims to comprehensively analyze the dynamic dissipation patterns of DFN, along with an investigation into the physiological, hormonal, and transcriptomic responses of wheat seedlings exposed to DFN. The results demonstrated that exposure of wheat roots to DFN (10 mg/kg in soil) led to a significant accumulation of DFN in wheat plants, with the DFN content in roots being notably higher than that in leaves. Accumulating DFN triggered an increase in reactive oxygen species content, malonaldehyde content, and antioxidant enzyme activities, while concurrently inhibiting photosynthesis. Transcriptome analysis further revealed that the number of differentially expressed genes was greater in roots compared with leaves under DFN stress. Key genes in roots and leaves that exhibited a positive response to DFN-induced stress were identified through weighted gene co-expression network analysis. Metabolic pathway analysis indicated that these key genes mainly encode proteins involved in glutathione metabolism, plant hormone signaling, amino acid metabolism, and detoxification/defense pathways. Further results indicated that abscisic acid and salicylic acid play vital roles in the detoxification of leaf and root DFN, respectively. In brief, the abovementioned findings contribute to a deeper understanding of the detrimental effects of DFN on wheat seedlings, while shedding light on the molecular mechanisms underlying the responses of wheat root and leaves to DFN exposure.


Subject(s)
Plant Growth Regulators , Triticum , Humans , Plant Growth Regulators/pharmacology , Plant Growth Regulators/metabolism , Triticum/genetics , Triticum/metabolism , Gene Expression Profiling , Antioxidants/pharmacology , Hormones/metabolism , Hormones/pharmacology , Seedlings , Stress, Physiological/genetics , Plant Roots/metabolism
5.
Mikrochim Acta ; 190(10): 383, 2023 09 12.
Article in English | MEDLINE | ID: mdl-37697171

ABSTRACT

Covalent organic framework-coated magnetite particles (Fe3O4@COF) were synthesized and applied as the adsorbent to the selective capture of phthalate esters (PAEs) in liquid foods. Combined with the magnetic solid-phase extraction (MSPE) technology, a gas chromatography-tandem mass spectrometry (GC-MS/MS) method was employed for the separation and quantification of PAEs. Following optimization of the magnetic extraction and elution parameters, the developed analytical method offered a satisfactory linear range (0.1-5 µg L-1) with determination coefficients ranging from 0.9934 to 0.9975 for the five different PAEs studied. The limits of detection (LOD) were in the range 1.9-12.8 ng L-1. The recoveries ranged from 70.0 to 119.8% with a relative standard deviation (RSD) less than 9.7%. Density functional theory (DFT) calculations established that the dominant adsorption mechanism used by the COF to bind PAEs involved π-π stacking interactions. Results encourage the wider use of COF-based adsorbents and MSPE methods in the analytical determination of PAEs in foods.


Subject(s)
Metal-Organic Frameworks , Tandem Mass Spectrometry , Gas Chromatography-Mass Spectrometry , Solid Phase Extraction , Magnetic Phenomena , Esters
6.
Mikrochim Acta ; 190(5): 169, 2023 Apr 04.
Article in English | MEDLINE | ID: mdl-37016038

ABSTRACT

Molecularly imprinted polymers (MIPs) were combined with surface-enhanced Raman scattering (SERS) and AgNPs were prepared by in situ reduction within the MIP for selective and sensitive detection of sulfamethazine (SMZ). The MIP@AgNPs composites were characterized in detail by several analytical techniques, showing the generation of polymers and the formation of AgNPs hot spots. The specific affinity and rapid adsorption equilibrium rates of MIP@AgNPs composites were verified by static and kinetic adsorption studies. The MIP@AgNPs with high selectivity and excellent sensitivity were used as SERS substrates to detect SMZ. A good linear correlation (R2 = 0.996) in rang of 10-10-10-6 mol L-1 was observed between the Raman signal (1596 cm-1) and the concentration of SMZ. The limit of detection (LOD) was as low as 8.10 × 10-11 mol L-1 with relative standard deviations (RSD) of 6.32%. The good stability and reproducibility are also fully reflected in the SERS detection based on MIP@AgNPs. The method was successfully applied to the analysis of lake water samples, with recoveries in the range 85.1% to 102.5%. In summary, SERS detection based on MIP@AgNPs can be developed for a wider and broader range of practical applications. Schematic illustration of MIP@AgNPs sensor for the SERS detection of sulfamethazine.

7.
Nat Mater ; 20(10): 1385-1391, 2021 10.
Article in English | MEDLINE | ID: mdl-34112977

ABSTRACT

Replacing scarce and expensive platinum (Pt) with metal-nitrogen-carbon (M-N-C) catalysts for the oxygen reduction reaction in proton exchange membrane fuel cells has largely been impeded by the low oxygen reduction reaction activity of M-N-C due to low active site density and site utilization. Herein, we overcome these limits by implementing chemical vapour deposition to synthesize Fe-N-C by flowing iron chloride vapour over a Zn-N-C substrate at 750 °C, leading to high-temperature trans-metalation of Zn-N4 sites into Fe-N4 sites. Characterization by multiple techniques shows that all Fe-N4 sites formed via this approach are gas-phase and electrochemically accessible. As a result, the Fe-N-C catalyst has an active site density of 1.92 × 1020 sites per gram with 100% site utilization. This catalyst delivers an unprecedented oxygen reduction reaction activity of 33 mA cm-2 at 0.90 V (iR-corrected; i, current; R, resistance) in a H2-O2 proton exchange membrane fuel cell at 1.0 bar and 80 °C.

8.
Angew Chem Int Ed Engl ; 60(28): 15344-15347, 2021 Jul 05.
Article in English | MEDLINE | ID: mdl-33904226

ABSTRACT

Cu-based electrocatalysts facilitate CO2 electrochemical reduction (CO2 ER) to produce multi-carbon products. However, the roles of Cu0 and Cu+ and the mechanistic understanding remain elusive. This paper describes the controllable construction of Cu0 -Cu+ sites derived from the well-dispersed cupric oxide particles supported on copper phyllosilicate lamella to enhance CO2 ER performance. 20 % Cu/CuSiO3 shows the superior CO2 ER performance with 51.8 % C2 H4 Faraday efficiency at -1.1 V vs reversible hydrogen electrode during the 6 hour test. In situ attenuated total reflection infrared spectra and density functional theory (DFT) calculations were employed to elucidate the reaction mechanism. The enhancement in CO2 ER activity is mainly attributed to the synergism of Cu0 -Cu+ pairs: Cu0 activates CO2 and facilitates the following electron transfers; Cu+ strengthens *CO adsorption to further boost C-C coupling. We provide a strategy to rationally design Cu-based catalysts with viable valence states to boost CO2 ER.

9.
Angew Chem Int Ed Engl ; 60(9): 4879-4885, 2021 Feb 23.
Article in English | MEDLINE | ID: mdl-33231928

ABSTRACT

Copper can efficiently electro-catalyze carbon dioxide reduction to C2+ products (C2 H4 , C2 H5 OH, n-propanol). However, the correlation between the activity and active sites remains ambiguous, impeding further improvements in their performance. The facet effect of copper crystals to promote CO adsorption and C-C coupling and consequently yield a superior selectivity for C2+ products is described. We achieve a high Faradaic efficiency (FE) of 87 % and a large partial current density of 217 mA cm-2 toward C2+ products on Cu(OH)2 -D at only -0.54 V versus the reversible hydrogen electrode in a flow-cell electrolyzer. With further coupled to a Si solar cell, record-high solar conversion efficiencies of 4.47 % and 6.4 % are achieved for C2 H4 and C2+ products, respectively. This study provides an in-depth understanding of the selective formation of C2+ products on Cu and paves the way for the practical application of electrocatalytic or solar-driven CO2 reduction.

10.
Angew Chem Int Ed Engl ; 60(21): 11707-11712, 2021 May 17.
Article in English | MEDLINE | ID: mdl-33605017

ABSTRACT

The commercial success of the electrochemical energy conversion technologies required for the decarbonization of the energy sector requires the replacement of the noble metal-based electrocatalysts currently used in (co-)electrolyzers and fuel cells with inexpensive, platinum-group metal-free analogs. Among these, Fe/N/C-type catalysts display promising performances for the reduction of O2 or CO2 , but their insufficient activity and stability jeopardize their implementation in such devices. To circumvent these issues, a better understanding of the local geometric and electronic structure of their catalytic active sites under reaction conditions is needed. Herein we shed light on the electronic structure of the molecular sites in two Fe/N/C catalysts by probing their average spin state with X-ray emission spectroscopy (XES). Chiefly, our in situ XES measurements reveal for the first time the existence of reversible, potential-induced spin state changes in these materials.

11.
J Am Chem Soc ; 142(46): 19602-19610, 2020 11 18.
Article in English | MEDLINE | ID: mdl-33108194

ABSTRACT

NADPH oxidase (NOX) as a transmembrane enzyme complex controls the generation of superoxide that plays important roles in immune signaling pathway. NOX inactivation may elicit immunodeficiency and cause chronic granulomatous disease (CGD). Biocompatible synthetic materials with NOX-like activities would therefore be interesting as curative and/or preventive approaches in case of NOX deficiency. Herein, we synthesized a Fe-N doped graphene (FeNGR) nanomaterial that could mimic the activity of NOX by efficiently catalyzing the conversion of NADPH into NADP+ and triggering the generation of oxygen radicals. The resulting FeNGR nanozyme had similar cellular distribution to NOX and is able to mimic the enzyme function in NOX-deficient cells by catalyzing the generation of superoxide and retrieving the immune activity, evidenced by TNF-α, IL-1ß, and IL-6 production in response to Alum exposure. Overall, our study discovered a synthetic material (FeNGR) to mimic NOX and demonstrated its biological function in immune activation of NOX-deficient cells.


Subject(s)
Biomimetic Materials/chemistry , Graphite/chemistry , Iron/chemistry , NADPH Oxidases/chemistry , Nitrogen/chemistry , Biomimetic Materials/metabolism , Fluorescent Dyes/chemistry , Humans , Interleukin-1beta/metabolism , Interleukin-6/metabolism , Models, Molecular , NADP/metabolism , NADPH Oxidases/metabolism , Oxidation-Reduction , Peroxidase/metabolism , Reactive Oxygen Species/chemistry , Signal Transduction , Superoxides/chemistry , Superoxides/metabolism , THP-1 Cells , Tumor Necrosis Factor-alpha/metabolism
12.
J Am Chem Soc ; 142(3): 1417-1423, 2020 Jan 22.
Article in English | MEDLINE | ID: mdl-31880925

ABSTRACT

Pyrolysis is indispensable for synthesizing highly active Fe-N-C catalysts for the oxygen reduction reaction (ORR) in acid, but how Fe, N, and C precursors transform to ORR-active sites during pyrolysis remains unclear. This knowledge gap obscures the connections between the input precursors and the output products, clouding the pathway toward Fe-N-C catalyst improvement. Herein, we unravel the evolution pathway of precursors to ORR-active catalyst comprised exclusively of single-atom Fe1(II)-N4 sites via in-temperature X-ray absorption spectroscopy. The Fe precursor transforms to Fe oxides below 300 °C and then to tetrahedral Fe1(II)-O4 via a crystal-to-melt-like transformation below 600 °C. The Fe1(II)-O4 releases a single Fe atom that diffuses into the N-doped carbon defect forming Fe1(II)-N4 above 600 °C. This vapor-phase single Fe atom transport mechanism is verified by synthesizing Fe1(II)-N4 sites via "noncontact pyrolysis" wherein the Fe precursor is not in physical contact with the N and C precursors during pyrolysis.

13.
Prostate ; 80(12): 1024-1037, 2020 09.
Article in English | MEDLINE | ID: mdl-32628792

ABSTRACT

BACKGROUND: Dysregulation of microRNAs has performed vital gene regulatory functions in the genesis, progression, and prognosis of multiple malignant tumors. This study aimed to elucidate the regulatory mechanism of miR-196a in prostate cancer (PCa) and explore its clinical significance. METHODS: Quantitative real-time polymerase chain reaction was implemented to examine miR-196a and p27kip1 messenger RNA expression in PCa. Cell proliferation was evaluated via Cell Counting Kit-8, colony formation, and nude mouse tumorigenicity assays. Luciferase reporter assay was applied to identify target genes. p27kip1 protein expression in PCa was investigated using Western blot analysis and immunohistochemistry. RESULTS: There was a dramatic upregulation of miR-196a in PCa. Upregulated miR-196a was related to worse Gleason score (GS), later pathological stage, and poor biochemical recurrence (BCR)-free survival. In vivo and in vitro experiments exhibited that miR-196a promoted PCa proliferation and expedited G1/S-phase progression through the downregulation of p27kip1 protein. Additionally, p27kip1 protein was distinctly downregulated in PCa. Low p27kip1 protein expression had a strong correlation with increased GS and was an independent predictor of BCR after radical prostatectomy (RP). CONCLUSIONS: Excessive expression of miR-196a and subsequent downregulation of p27kip1 protein play essential roles in promoting PCa proliferation and leading to BCR after RP. miR-196a and its target p27kip1 may become novel molecular biomarkers and therapeutic targets for PCa.


Subject(s)
Cyclin-Dependent Kinase Inhibitor p27/metabolism , MicroRNAs/metabolism , Prostatic Neoplasms/metabolism , Cell Line, Tumor , Cell Proliferation/physiology , Cyclin-Dependent Kinase Inhibitor p27/biosynthesis , Cyclin-Dependent Kinase Inhibitor p27/genetics , Down-Regulation , HEK293 Cells , Humans , Immunohistochemistry , Male , MicroRNAs/biosynthesis , MicroRNAs/genetics , Neoplasm Recurrence, Local/genetics , Neoplasm Recurrence, Local/metabolism , Neoplasm Recurrence, Local/pathology , PC-3 Cells , Prostatectomy/methods , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Prostatic Neoplasms/surgery
14.
J Gen Intern Med ; 35(9): 2621-2628, 2020 09.
Article in English | MEDLINE | ID: mdl-32462572

ABSTRACT

BACKGROUND: Variability in the quality of stroke care is widespread. Identifying performance-based outlier hospitals based on quality indicators (QIs) has become a common practice. OBJECTIVES: To develop a tool for identifying performance-based outlier hospitals based on risk-adjusted adherence rates of process indicators. DESIGN: Hospitals were classified into five-level outliers based on the observed-to-expected ratio and P value. The composite quality score was derived by summation of the points for each indicator for each hospital, and associations between outlier status and outcomes were determined. PARTICIPANTS: Patients diagnosed with acute ischemic stroke, January 1, 2011-May 31, 2017. INTERVENTION: N/A MAIN OUTCOME MEASURES: Independence at discharge (the modified Rankin Scale = 0-2). KEY RESULTS: A total of 501,132 patients from 519 hospitals were identified. From 0.39 to 19.65% of hospitals were identified as high outliers according to various QIs. Composite quality scores ranged from - 20 to 16. Providers that were high outliers based on QI2, QI8, QI9, and QI11 had higher independent rates. For composite quality score, each point increase corresponded to an 8% increase in the odds of independent rate. CONCLUSION: Nationwide variation in the quality of acute stroke care exists at the hospital level. Variability in the quality of stroke care can be captured by our proposed quality score. Applying this quality score as a benchmarking tool could provide audit-level feedback to policymakers and hospitals to aid quality improvement.


Subject(s)
Brain Ischemia , Stroke , China/epidemiology , Humans , Quality Improvement , Quality Indicators, Health Care , Stroke/diagnosis , Stroke/therapy
15.
Angew Chem Int Ed Engl ; 59(8): 3235-3243, 2020 Feb 17.
Article in English | MEDLINE | ID: mdl-31799800

ABSTRACT

Fe-N-C catalysts containing atomic FeNx sites are promising candidates as precious-metal-free catalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells. The durability of Fe-N-C catalysts in fuel cells has been extensively studied using accelerated stress tests (AST). Herein we reveal stronger degradation of the Fe-N-C structure and four-times higher ORR activity loss when performing load cycling AST in O2 - vs. Ar-saturated pH 1 electrolyte. Raman spectroscopy results show carbon corrosion after AST in O2 , even when cycling at low potentials, while no corrosion occurred after any load cycling AST in Ar. The load-cycling AST in O2 leads to loss of a significant fraction of FeNx sites, as shown by energy dispersive X-ray spectroscopy analyses, and to the formation of Fe oxides. The results support that the unexpected carbon corrosion occurring at such low potential in the presence of O2 is due to reactive oxygen species produced between H2 O2 and Fe sites via Fenton reactions.

16.
J Am Chem Soc ; 141(7): 3232-3239, 2019 02 20.
Article in English | MEDLINE | ID: mdl-30673227

ABSTRACT

Despite the fundamental and practical significance of the hydrogen evolution and oxidation reactions (HER/HOR), their kinetics in base remain unclear. Herein, we show that the alkaline HER/HOR kinetics can be unified by the catalytic roles of the adsorbed hydroxyl (OHad)-water-alkali metal cation (AM+) adducts, on the basis of the observations that enriching the OHad abundance via surface Ni benefits the HER/HOR; increasing the AM+ concentration only promotes the HER, while varying the identity of AM+ affects both HER/HOR. The presence of OHad-(H2O) x-AM+ in the double-layer region facilitates the OHad removal into the bulk, forming OH--(H2O) x-AM+ as per the hard-soft acid-base theory, thereby selectively promoting the HER. It can be detrimental to the HOR as per the bifunctional mechanism, as the AM+ destabilizes the OHad, which is further supported by the CO oxidation results. This new notion may be important for alkaline electrochemistry.

17.
J Am Chem Soc ; 141(31): 12372-12381, 2019 Aug 07.
Article in English | MEDLINE | ID: mdl-31306016

ABSTRACT

Nitrogen-doped carbon materials featuring atomically dispersed metal cations (M-N-C) are an emerging family of materials with potential applications for electrocatalysis. The electrocatalytic activity of M-N-C materials toward four-electron oxygen reduction reaction (ORR) to H2O is a mainstream line of research for replacing platinum-group-metal-based catalysts at the cathode of fuel cells. However, fundamental and practical aspects of their electrocatalytic activity toward two-electron ORR to H2O2, a future green "dream" process for chemical industry, remain poorly understood. Here we combined computational and experimental efforts to uncover the trends in electrochemical H2O2 production over a series of M-N-C materials (M = Mn, Fe, Co, Ni, and Cu) exclusively comprising atomically dispersed M-Nx sites from molecular first-principles to bench-scale electrolyzers operating at industrial current density. We investigated the effect of the nature of a 3d metal within a series of M-N-C catalysts on the electrocatalytic activity/selectivity for ORR (H2O2 and H2O products) and H2O2 reduction reaction (H2O2RR). Co-N-C catalyst was uncovered with outstanding H2O2 productivity considering its high ORR activity, highest H2O2 selectivity, and lowest H2O2RR activity. The activity-selectivity trend over M-N-C materials was further analyzed by density functional theory, providing molecular-scale understandings of experimental volcano trends for four- and two-electron ORR. The predicted binding energy of HO* intermediate over Co-N-C catalyst is located near the top of the volcano accounting for favorable two-electron ORR. The industrial H2O2 productivity over Co-N-C catalyst was demonstrated in a microflow cell, exhibiting an unprecedented production rate of more than 4 mol peroxide gcatalyst-1 h-1 at a current density of 50 mA cm-2.

18.
BMC Cancer ; 19(1): 1099, 2019 Nov 12.
Article in English | MEDLINE | ID: mdl-31718596

ABSTRACT

BACKGROUND: There are differences in the quality of care among breast cancer patients. Narrowing the quality differences could be achieved by increasing the utilization rate of indicators. Here we explored key indicators that can improve the quality of care and factors that may affect the use of these indicators. METHODS: A total of 3669 breast cancer patients were included in our retrospective study. We calculated patient quality-of-care composite score based on patient average method. Patients were divided into high- and low-quality groups according to the mean score. We obtained the indicators with large difference in utilization between the two groups. Multilevel logistic regression model was used to analyze the factors influencing quality of care and use of indicators. RESULTS: The mean composite score was 0.802, and the number of patients in the high- and low-quality groups were 1898 and 1771, respectively. Four indicators showed a difference in utilization between the two groups of over 40%. Histological grade, pathological stage, tumor size and insurance type were the factors affecting the quality of care. In single indicator evaluation, besides the above factors, age, patient income and number of comorbidities may also affect the use of these four indicators. Number of comorbidities may have opposite effects on the use of different indicators, as does pathological stage. CONCLUSIONS: Identifying key indicators for enhancing the quality-of-care of breast cancer patients and factors that affect the indicator adherence may provide guides for enhancing the utilization rate of these indicators in clinical practice.


Subject(s)
Breast Neoplasms/epidemiology , Quality Indicators, Health Care , Quality of Health Care , Adult , Aged , Breast Neoplasms/diagnosis , Breast Neoplasms/therapy , Factor Analysis, Statistical , Female , Humans , Middle Aged , Neoplasm Staging , Young Adult
19.
Nano Lett ; 18(2): 798-804, 2018 02 14.
Article in English | MEDLINE | ID: mdl-29272136

ABSTRACT

Doping with a transition metal was recently shown to greatly boost the activity and durability of PtNi/C octahedral nanoparticles (NPs) for the oxygen reduction reaction (ORR), but its specific roles remain unclear. By combining electrochemistry, ex situ and in situ spectroscopic techniques, density functional theory calculations, and a newly developed kinetic Monte Carlo model, we showed that Mo atoms are preferentially located on the vertex and edge sites of Mo-PtNi/C in the form of oxides, which are stable within the wide potential window of the electrochemical cycle. These surface Mo oxides stabilize adjacent Pt sites, hereby stabilizing the octahedral shape enriched with (111) facets, and lead to increased concentration of Ni in subsurface layers where they are protected against acid dissolution. Consequently, the favorable Pt3Ni(111) structure for the ORR is stabilized on the surface of PtNi/C NPs in acid against voltage cycling. Significantly, the unusual potential-dependent oxygen coverage trend on Mo-doped PtNi/C NPs as revealed by the surface-sensitive Δµ analysis suggests that the Mo dopants may also improve the ORR kinetics by modifying the coordination environments of Pt atoms on the surface. Our studies point out a possible way to stabilize the favorable shape and composition established on conceptual catalytic models in practical nanoscale catalysts.

20.
Molecules ; 24(2)2019 Jan 10.
Article in English | MEDLINE | ID: mdl-30634608

ABSTRACT

Gastrodia elata Blume (G. elata) is a prominent traditional herb and its dry tuber is officially listed in the Chinese Pharmacopoeia. To ensure the quality of dried G. elata, the establishment of a nondestructive and convenient method to monitor the drying process is necessary. In this study, a nondestructive low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) method was introduced to monitor the drying process of G. elata. Three water states (bound, immobilized, and free) in G. elata samples were investigated through multiexponential fitting and inversion of the NMR data. The variation and distribution of the three water states during drying were monitored by LF-NMR, and the spatial distribution of water and internal structural changes were analyzed by MRI. Linear analysis of the moisture content, L* (lightness), b* (yellowness), and NMR parameters showed good correlations among them. Furthermore, partial least squares regression (PLSR) model analysis, which takes into account all NMR parameters, also showed good correlations among these parameters. All results showed that LF-NMR was feasible and convenient for monitoring moisture content. Therefore, LF-NMR and MRI could be used to monitor the moisture content nondestructively in the drying process of Chinese traditional herbs.


Subject(s)
Desiccation/methods , Gastrodia/chemistry , Water/analysis , Least-Squares Analysis , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy , Plant Extracts/chemistry
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