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1.
Nanoscale ; 16(23): 11350-11352, 2024 Jun 13.
Article in English | MEDLINE | ID: mdl-38836329

ABSTRACT

Correction for 'Ultrafast switching to zero field topological spin textures in ferrimagnetic TbFeCo films' by Kaixin Zhu et al., Nanoscale, 2024, 16, 3133-3143, https://doi.org/10.1039/D3NR04529C.

2.
J Neuroinflammation ; 21(1): 148, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38840180

ABSTRACT

BACKGROUND: White matter injury (WMI) represents a significant etiological factor contributing to neurological impairment subsequent to Traumatic Brain Injury (TBI). CD36 receptors are recognized as pivotal participants in the pathogenesis of neurological disorders, including stroke and spinal cord injury. Furthermore, dynamic fluctuations in the phenotypic polarization of microglial cells have been intimately associated with the regenerative processes within the injured tissue following TBI. Nevertheless, there is a paucity of research addressing the impact of CD36 receptors on WMI and microglial polarization. This investigation aims to elucidate the functional role and mechanistic underpinnings of CD36 in modulating microglial polarization and WMI following TBI. METHODS: TBI models were induced in murine subjects via controlled cortical impact (CCI). The spatiotemporal patterns of CD36 expression were examined through quantitative polymerase chain reaction (qPCR), Western blot analysis, and immunofluorescence staining. The extent of white matter injury was assessed via transmission electron microscopy, Luxol Fast Blue (LFB) staining, and immunofluorescence staining. Transcriptome sequencing was employed to dissect the molecular mechanisms underlying CD36 down-regulation and its influence on white matter damage. Microglial polarization status was ascertained using qPCR, Western blot analysis, and immunofluorescence staining. In vitro, a Transwell co-culture system was employed to investigate the impact of CD36-dependent microglial polarization on oligodendrocytes subjected to oxygen-glucose deprivation (OGD). RESULTS: Western blot and qPCR analyses revealed that CD36 expression reached its zenith at 7 days post-TBI and remained sustained at this level thereafter. Immunofluorescence staining exhibited robust CD36 expression in astrocytes and microglia following TBI. Genetic deletion of CD36 ameliorated TBI-induced white matter injury, as evidenced by a reduced SMI-32/MBP ratio and G-ratio. Transcriptome sequencing unveiled differentially expressed genes enriched in processes linked to microglial activation, regulation of neuroinflammation, and the TNF signaling pathway. Additionally, bioinformatics analysis pinpointed the Traf5-p38 axis as a critical signaling pathway. In vivo and in vitro experiments indicated that inhibition of the CD36-Traf5-MAPK axis curtailed microglial polarization toward the pro-inflammatory phenotype. In a Transwell co-culture system, BV2 cells treated with LPS + IFN-γ exacerbated the damage of post-OGD oligodendrocytes, which could be rectified through CD36 knockdown in BV2 cells. CONCLUSIONS: This study illuminates that the suppression of CD36 mitigates WMI by constraining microglial polarization towards the pro-inflammatory phenotype through the down-regulation of the Traf5-MAPK signaling pathway. Our findings present a potential therapeutic strategy for averting neuroinflammatory responses and ensuing WMI damage resulting from TBI.


Subject(s)
CD36 Antigens , Mice, Inbred C57BL , Microglia , Animals , Microglia/metabolism , Microglia/pathology , Mice , CD36 Antigens/metabolism , CD36 Antigens/genetics , Mice, Knockout , White Matter/pathology , White Matter/metabolism , MAP Kinase Signaling System/physiology , Male , Cell Polarity/physiology , Brain Injuries, Traumatic/metabolism , Brain Injuries, Traumatic/pathology , Signal Transduction/physiology
3.
Adv Mater ; 36(26): e2403328, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38586929

ABSTRACT

Metal-organic frameworks (MOFs) have emerged as promising platforms for photocatalytic hydrogen evolution reaction (HER) due to their fascinating physiochemical properties. Rationally engineering the compositions and structures of MOFs can provide abundant opportunities for their optimization. In recent years, high-entropy materials (HEMs) have demonstrated great potential in the energy and environment fields. However, there is still no report on the development of high-entropy MOFs (HE-MOFs) for photocatalytic HER in aqueous solution. Herein, the authors report the synthesis of a novel p-type HE-MOFs single crystal (HE-MOF-SC) and the corresponding HE-MOFs nanosheets (HE-MOF-NS) capable of realizing visible-light-driven photocatalytic HER. Both HE-MOF-SC and HE-MOF-NS exhibit higher photocatalytic HER activity than all the single-metal MOFs, which are supposed to be ascribed to the interplay between the different metal nodes in the HE-MOFs that enables more efficient charge transfer. Moreover, impressively, the HE-MOF-NS demonstrates much higher photocatalytic activity than the HE-MOF-SC due to its thin thickness and enhanced surface area. At optimum conditions, the rate of H2 evolution on the HE-MOF-NS is ≈13.24 mmol h-1 g-1, which is among the highest values reported for water-stable MOF photocatalysts. This work highlights the importance of developing advanced high-entropy materials toward enhanced photocatalysis.

4.
J Am Chem Soc ; 146(9): 5834-5842, 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38277793

ABSTRACT

Electrochemical conversion of CH4 to easily transportable and value-added liquid fuels is highly attractive for energy-efficient CH4 utilization, but it is challenging due to the low reactivity and solubility of CH4 in the electrolyte. Herein, we report a high-pressure electro-Fenton (HPEF) strategy to establish a hetero-homogeneous process for the electrocatalytic conversion of CH4 by O2 at room temperature. In combination with elevation of reactant pressure to accelerate reaction kinetics, it delivers an unprecedented HCOOH productivity of 11.5 mmol h-1 gFe-1 with 220 times enhancement compared to that under ambient pressure. Remarkably, an HCOOH Faradic efficiency of 81.4% can be achieved with an ultralow cathodic overpotential of 0.38 V. The elevated pressure not only promotes the electrocatalytic reduction of O2 to H2O2 but also increases the reaction collision probability between CH4 and •OH, which is in situ generated from the Fe2+-facilitated decomposition of H2O2.

5.
Nanoscale ; 16(6): 3133-3143, 2024 Feb 08.
Article in English | MEDLINE | ID: mdl-38258484

ABSTRACT

The capability of femtosecond (fs) laser pulses to manipulate topological spin textures on a very short time scale is sparking considerable interest. This article presents the creation of high density zero field topological spin textures by fs laser excitation in ferrimagnetic TbFeCo amorphous films. The topological spin textures are demonstrated to emerge under fs laser pulse excitation through a unique ultrafast nucleation mechanism, rather than thermal effects. Notably, large intrinsic uniaxial anisotropy could substitute the external magnetic field for the creation and stabilization of topological spin textures, which is further verified by the corresponding micromagnetic simulation. The ultrafast switching between topological trivial and nontrivial magnetic states is realized at an optimum magnitude of magnetic field and laser fluence. Our results would broaden the options to generate zero-field topological spin textures from versatile magnetic states and provides a new perspective for ultrafast switching of 0/1 magnetic states in spintronic devices.

6.
FASEB J ; 37(9): e23112, 2023 09.
Article in English | MEDLINE | ID: mdl-37534961

ABSTRACT

Traumatic brain injury (TBI), particularly diffuse axonal injury (DAI), often results in sympathetic hyperactivity, which can exacerbate the prognosis of TBI patients. A key component of this process is the role of neutrophils in causing neuroinflammation after TBI by forming neutrophil extracellular traps (NETs), but the connection between NETs and sympathetic excitation following TBI remains unclear. Utilizing a DAI rat model, the current investigation examined the role of NETs and the HMGB1/JNK/AP1 signaling pathway in this process. The findings revealed that sympathetic excitability intensifies and peaks 3 days post-injury, a pattern mirrored by the activation of microglia, and the escalated NETs and HMGB1 levels. Subsequent in vitro exploration validated that HMGB1 fosters microglial activation via the JNK/AP1 pathway. Moreover, in vivo experimentation revealed that the application of anti-HMGB1 and AP1 inhibitors can mitigate microglial M1 polarization post-DAI, effectively curtailing sympathetic hyperactivity. Therefore, this research elucidates that post-TBI, NETs within the PVN may precipitate sympathetic hyperactivity by stimulating M1 microglial polarization through the HMGB1/JNK/AP1 pathway.


Subject(s)
Brain Injuries, Traumatic , Extracellular Traps , Rats , Animals , Mice , Microglia/metabolism , Extracellular Traps/metabolism , Brain Injuries, Traumatic/metabolism , Phenotype , Mice, Inbred C57BL
7.
Front Chem ; 11: 1189450, 2023.
Article in English | MEDLINE | ID: mdl-37090245

ABSTRACT

Ruthenium (Ru) has been considered a promising electrocatalyst for electrochemical hydrogen evolution reaction (HER) while its performance is limited due to the problems of particle aggregation and competitive adsorption of the reaction intermediates. Herein, we reported the synthesis of a zinc (Zn) modified Ru nanocluster electrocatalyst anchored on multiwalled carbon nanotubes (Ru-Zn/MWCNTs). The Ru-Zn catalysts were found to be highly dispersed on the MWCNTs substrate. Moreover, the Ru-Zn/MWCNTs exhibited low overpotentials of 26 and 119 mV for achieving current intensities of 10 and 100 mA cm-2 under alkaline conditions, respectively, surpassing Ru/MWCNTs with the same Ru loading and the commercial 5 wt% Pt/C (47 and 270 mV). Moreover, the Ru-Zn/MWCNTs showed greatly enhanced stability compared to Ru/MWCNTs with no significant decay after 10,000 cycles of CV sweeps and long-term operation for 90 h. The incorporation of Zn species was found to modify the electronic structure of the Ru active species and thus modulate the adsorption energy of the Had and OHad intermediates, which could be the main reason for the enhanced HER performance. This study provides a strategy to develop efficient and stable electrocatalysts towards the clean energy conversion field.

8.
Polymers (Basel) ; 15(3)2023 Jan 30.
Article in English | MEDLINE | ID: mdl-36772004

ABSTRACT

Eco-gelled coal gangue materials (EGCGMs) are usually produced using coal gangue, slag, and fly ash in a highly alkaline environment. Herein, to improve the mechanical properties of such materials, polypropylene fibers were uniformly mixed with them. An unconfined compressive strength test and a three-point bending test of the fiber-reinforced EGCGMs under different conditions were conducted. Based on the performance degradation control technology of the fiber structure, the interface mechanism of the composite materials was analyzed from the micro level using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). In the mechanical test, the 28 d UCS and flexural properties of the fiber-reinforced EGCGMs were analyzed using the Box-Behnken design response surface design method and orthogonal design method, respectively. The order of significance was as follows: sodium hydroxide, fiber length, and fiber content. Within the scope of the experimental study, when the NaOH content is 3, the fiber content is 5 ‱, and the fiber length is 9 mm, the mechanical properties are the best. Based on the microscopic equipment, it was discovered that the amorphous ecological glue condensation product formed by the reaction of slag and fly ash in the alkaline environment was filled between the coal gangue particles and the fibers, and several polymerization products accumulated to form a honeycomb network topology. The distribution of fibers in the EGCGM matrix could be primarily divided into single embedded and network occurrences. The fiber inhibits the crack initiation and development of the matrix through the crack resistance effect, and improves the brittleness characteristics through the bridging effect during the failure process, which promotes the ductility of the ecological cementitious coal gangue matrix.The results presented herein can provide a theoretical basis for improving the mechanical properties of alkali-activated geopolymers.

9.
Low Urin Tract Symptoms ; 13(4): 481-489, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34240558

ABSTRACT

OBJECTIVES: We aimed to determine the prevalence of urinary incontinence (UI) during the peri- and postpartum period in women from Nanjing, China, and estimate its risk factors. METHODS: From January to December 2018, a total of 6500 postpartum women were enrolled and asked to complete the questionnaires. Of these, 6370 (98%) women returned the questionnaires with valid responses. Additional data were collected, including age, height, weight, gestation time and parity, and neonatal weight. The International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form was used. Surface electromyography (sEMG) and a biofeedback training system were used as a testing platform, and PESEMG values were obtained. RESULTS: The prevalence of UI during pregnancy and at 6 weeks postpartum in women was 29.76% and 12.50%, respectively. The prevalence of stress UI (SUI), urge UI (UUI), mixed UI (MUI), and other types of UI that developed during pregnancy was 25.48%, 1.66%, 1.65%, and 0.97%, respectively. The prevalence of SUI, UUI, MUI, and other types of UI at 6 weeks postpartum was 8.49%, 2.07%, 1.16%, and 0.77%, respectively. Multivariate analysis showed that advanced age, greater postpartum body mass index (BMI), macrosomia, multiparity, and vaginal delivery were risk factors of postpartum UI. Women with mild degree of UI in pregnancy, those who had undergone cesarean section, and those without UI before pregnancy were relieved from UI at 6 weeks postpartum. CONCLUSIONS: The rate of UI in peri- and postpartum women from Nanjing is consistent across China. The most common type of UI was SUI, with many risk factors affecting its occurrence. Advanced age, greater postpartum BMI, multiparity, macrosomia, and vaginal delivery might be the main risk factors of UI in postpartum women.


Subject(s)
Urinary Incontinence, Stress , Urinary Incontinence , Cesarean Section , China/epidemiology , Female , Humans , Infant, Newborn , Postpartum Period , Pregnancy , Prevalence , Risk Factors , Surveys and Questionnaires , Urinary Incontinence/epidemiology , Urinary Incontinence, Stress/epidemiology , Urinary Incontinence, Urge/epidemiology
10.
Front Neurosci ; 15: 621477, 2021.
Article in English | MEDLINE | ID: mdl-33994918

ABSTRACT

Background: Paroxysmal sympathetic hyperactivity (PSH) is one of the important reasons for the high mortality and morbidity of traumatic brain injury (TBI). We aim to explore the role of the neutrophil extracellular traps (NETs) in the pathogenesis of sympathetic hyperexcitability after TBI and the underlying mechanisms, providing evidence for clinical treatment. Methods: Enzyme-linked immunosorbent assay was used to assess the plasma metanephrine and normetanephrine levels which represented the variation of the sympathetic system after TBI with rat diffuse axonal injury (DAI) model. NETs in the paraventricular nucleus (PVN) and circulating blood were examined using immunofluorescence and flow cytometry. Neutrophils-microglia co-culture system was established to further explore the effect of NETs on PSH and its mechanisms. Results: After TBI, metanephrine and normetanephrine levels began to increase at 9 h and peaked at 72 h. After the injury, the level of NETs kept increasing at 24 and 72 h in the PVN. A positive correlation was found between the concentration of the PVN NETs and blood catecholamine. Flow cytometry of peripheral blood cells revealed that NETs level in the injury group was higher than that in the control group. Immunofluorescence results confirmed the presence of NETs in the PVN after TBI. The positive result of immunoprecipitation suggested a correlation effect between LL37 and P2 × 7. Peptidyl arginine deiminase-4 (PAD4) inhibitor could inhibit the expression levels of MST1, YAP, and IL-1ß. The hippo/MST1 pathway inhibitor could inhibit the expression levels of YAP and IL-1ß. Conclusion: NETs formation in the PVN might be associated with sympathetic hyperactivity after TBI, which might relate to the activation of microglia cells and increased secretion of IL-1ß via the hippo/MST1 pathway.

11.
Article in English | MEDLINE | ID: mdl-33921023

ABSTRACT

The accessibility of urban fire services is a critical indicator in evaluating fire services and optimizing fire resource allocation. However, previous studies have mainly concentrated on measuring the spatial accessibility of fire services, and little, if any, consideration has been paid to exploring the spatiotemporal dynamics of the accessibility of urban fire services. Therefore, we used real-time travel time to extend an existing spatial accessibility method to measure the spatiotemporal accessibility of fire services in a case study of Nanjing, China. The results show that (1) the overall accessibility of fire incidents and fire stations in Nanjing, China, is uneven, with relatively high accessibility in the southwest and northeast of the city center; (2) the number of fire incidents with low-level accessibility apparently increases in rush hours (i.e., 07:00-09:00 and 17:00-19:00 h) in the southeast and north of the city center, and the fire incidents with medium-level and high-level accessibility easily change to lower levels under the influence of traffic congestion, with fire incidents with medium-level accessibility being affected the most; (3) the accessibility of fire stations changes over time with an obvious W pattern, with lower accessibility during rush hours than at other times, and several fire stations in the city center present an asymmetric W pattern; (4) the accessibility decline ratio for fire stations in rush hours is greater in the city center than in urban suburbs, and the decline ratios are strongly related to the travel time increase and the percent increase in uncovered fire incidents during rush hours. The results and findings demonstrate that our method can be used to explore the spatiotemporal dynamics of the accessibility of fire services, and so can guide policymakers in improving fire services.


Subject(s)
Health Services Accessibility , Travel , China , Cities , Health Services
12.
Brain Res ; 1762: 147450, 2021 07 01.
Article in English | MEDLINE | ID: mdl-33773978

ABSTRACT

BACKGROUND: Traumatic Brain Injury (TBI) present a significant burden to global health. Close association and mutual regulation exist between the brain and gut microbiota. In addition, metabolites may play an important role as intermediary mediators of the brain and gut microbiota. Consequently, the study sought to investigate the alterations in gut microbiota and metabolites after TBI and conducted a comprehensive analysis of the correlation between gut microbiota and metabolites after TBI in mice. METHODS: Changes in intestinal microbiota and metabolites in mice after moderate or severe traumatic brain injury were detected through 16S rDNA sequencing and the non-target LC-MS technology. Additionally, Pearson correlation analysis was used to explore the association between the microbiota and metabolites. RESULTS: TBI was able to change the composition of intestinal microbiota, resulting to a decrease in microbial diversity in the intestinal tract (sham vs sTBI: 8.35 ± 0.12 vs 7.71 ± 0.5, p < 0.01; sTBI vs mTBI: 7.71 ± 0.5 vs 8.25 ± 0.34, p < 0.05). The results also showed that TBI could change the types and abundance of metabolites (723 in mTBI and sham groups; 1221 in sTBI and sham groups; 324 in mTBI and sTBI groups). Moreover, some of the altered gut metabolites were significantly correlated with part of the altered gut microbes after TBI. CONCLUSIONS: TBI significantly changed intestinal microbiota as well as metabolites. Some of the altered microbiota and metabolites had a significant association. The results from this study provide information that paves way for future studies utilizing the brain gut axis theory in the diagnosis and treatment of TBI.


Subject(s)
Brain Injuries, Traumatic/metabolism , Brain-Gut Axis/physiology , Brain/metabolism , Gastrointestinal Microbiome/physiology , Metabolomics/methods , Animals , Brain/pathology , Brain Injuries, Traumatic/pathology , Male , Mice , Mice, Inbred C57BL
13.
Front Genet ; 12: 628841, 2021.
Article in English | MEDLINE | ID: mdl-33664770

ABSTRACT

Messager RNA (mRNA) can be modified in a variety of ways, among which the modification of N6-methyladenosine (m6A) is one of the most common ones. Recent studies have found that the m6A modification in mRNA could functionally regulate the splicing, localization, translation, and stability of mRNA, which might be closely related to multiple diseases. However, the roles of m6A modification in traumatic optic neuropathy (TON) are unknown. Herein, we detected the expression of m6A-related genes via quantitative real-time PCR (qRT-PCR) and performed methylated RNA immunoprecipitation sequencing (MeRIP-seq) as well as RNA-sequencing to analyze the alteration profiles of m6A modification after TON. The results showed that the expression of m6A-related genes (METTL3, WTAP, FTO, and ALKBH5) were all upregulated after TON. In all, 2,810 m6A peaks were differentially upregulated and 689 m6A peaks were downregulated. In addition, the hypermethylated and hypomethylated profiles of mRNA transcripts were also identified. To sum up, our study revealed the differentially expressed m6A modification in the early stage of TON, which may provide novel insights into the mechanism and treatment of TON.

14.
Anal Chem ; 93(4): 2207-2214, 2021 Feb 02.
Article in English | MEDLINE | ID: mdl-33410328

ABSTRACT

Photoionization mass spectrometry (PI-MS) is a powerful and highly sensitive analytical technique for online monitoring of volatile organic compounds (VOCs). However, due to the large difference of PI cross sections for different compounds and the limitation of photon energy, the ability of lamp-based PI-MS for detection of compounds with low PI cross sections and high ionization energies (IEs) is insufficient. Although the ion production rate can be improved by elevating the ion source pressure, the problem of generating plenty of cluster ions, such as [MH]+·(H2O)n (n = 1 and 2) and [M2]+, needs be solved. In this work, we developed a new nonuniform electric field high-pressure photoionization/photoionization-induced chemical ionization (NEF-HPPI/PICI) source with the abilities of both HPPI and PICI, which was accomplished through ion-molecule reactions with high-intensity H3O+ reactant ions generated by photoelectron ionization (PEI) of water molecules. By establishing a nonuniform electric field in a three-zone ionization region to enhance in-source declustering and using 99.999% helium as the carrier gas, not only the formation of cluster ions was significantly diminished, but the ion transmission efficiency was also improved. Consequently, the main characteristic ion for each analyte both in HPPI and PICI occupied more than 80%, especially [HCOOH·H]+ with a yield ratio of 99.2% for formic acid. The analytical capacity of this system was demonstrated by operando monitoring the hydrocarbons and oxygenated VOC products during the methanol-to-olefins and methane conversion catalytic reaction processes, exhibiting wide potential applications in process monitoring, reaction mechanism research, and online quality control.

15.
Nanoscale Adv ; 3(10): 2924-2933, 2021 May 18.
Article in English | MEDLINE | ID: mdl-36134181

ABSTRACT

Graphene-based hybrid composites as positive electrodes have aroused great interest in the field of hybrid supercapacitors. However, the charge storage capability of hybrid composites suffers from the scarce interaction between their end members to some extent. Herein, a hybrid composite with electrostatic interaction was obtained by employing a heterogeneous assembly strategy of Ni-Co layered double hydroxide (LDH) and sulfonated graphene nanosheets (SGN). Depending on the substitution of the negatively charged SGN for the interlayer nitrate anions compensating for the positively charged LDH host slabs, the abundance of Ni3+ on the surface of the hybrid composite could be increased to intensify the electrostatic interaction within hybrid composites. As expected, the effective coupling of LDH with SGN ensured the uniform incorporation of heterogeneous components. The unique structure of the hybrid composite accelerated electron transfer and ion diffusion processes during electrochemical reactions, which is beneficial to improve the electrochemical performance of battery-type electrodes. Further evaluation showed that the specific capacity of the LDH/SGN hybrid composite is 1177 C g-1 (2354 F g-1) at 1 A g-1. Additionally, the LDH/SGN//AC hybrid supercapacitor achieved an energy density of 43 W h kg-1 at 800 W kg-1 and still retained 94% of its initial specific capacitance over 10 000 cycles. The boosting effect of the electrostatic interaction within the hybrid composite on electrochemical properties offers a novel pathway for the development of supercapacitors.

16.
Chem Commun (Camb) ; 56(96): 15189-15192, 2020 Dec 08.
Article in English | MEDLINE | ID: mdl-33220678

ABSTRACT

Well-defined carbon shells encapsulating CoFe2O4 deliver superior performance in catalytic PMS activation for organics degradation with a reaction rate constant of 0.269 min-1, 4.7 times the hollow CoFe2O4 and 2.7 times the solid carbon sphere encapsulated one. This is attributed to the comprehensive effects of the Co2+ and C[double bond, length as m-dash]O active sites for free radical and nonradical mechanisms. The nanostructured materials outperformed most of the carbon- or cobalt-iron-based catalysts.

17.
Nanoscale ; 11(29): 13894-13902, 2019 Aug 07.
Article in English | MEDLINE | ID: mdl-31304947

ABSTRACT

Efficient charge and energy storage relies essentially on the development of innovative electrode materials with enhanced electrochemical kinetics. Herein, Ni0.55Co0.45C2O4 solid solution was successfully synthesized by a liquid-liquid interfacial reaction. The observation of the morphologies of Ni0.55Co0.45C2O4 depicts a peculiar micro-cuboid structure composed of nanoparticles in the size range of 13 to 23 nm, benefiting the increase in the contribution of surface-controlled reactions to charge storage processes. The results from X-ray diffraction and thermogravimetric analysis demonstrate the similarity of the crystal structure and thermal decomposition behavior between Ni0.55Co0.45C2O4 and CoC2O4, and indicate that the CoC2O4 lattice plays a role as the fundamental framework in the solid solution instead of NiC2O4. The electrochemical measurements show that Ni0.55Co0.45C2O4 achieves a higher specific capacity of 562 C g-1 at a current density of 1 A g-1 than its counterpart NiC2O4/CoC2O4 hybrids, due to this the alternative arrangement of nickel and cobalt species in the solid solution expedites the diffusion process of active ions during the electrochemical reaction. Depending on the enhancement of the electrochemical stability in the solid solution, Ni0.55Co0.45C2O4 electrodes retain 87.4% of the initial capacity after 4000 cycles. The assembled Ni0.55Co0.45C2O4//AC hybrid supercapacitor attains an energy density of 38.5 W h kg-1 at a power density of 799 W kg-1 with a long cycling life (80% of the initial capacitance after 10 000 cycles). The excellent electrochemical performance suggests that Ni0.55Co0.45C2O4 is a promising candidate electrode material for supercapacitors.

18.
Zhongguo Zhong Yao Za Zhi ; 44(11): 2283-2291, 2019 Jun.
Article in Chinese | MEDLINE | ID: mdl-31359655

ABSTRACT

To build up an identification method on cardiac glycosides in Taxillus chinensis and its Nerium indicum host, and evaluate the influence on medicine quality from host to T. chinensis, ultra-performance liquid chromatography coupled with quadrupole-time-of-flight tandem mass-mass spectrometry(UPLC-Q-TOF-MS/MS)was applied. The samples of T. chinensis(harvested from N. indicum)and its N. indicum host were collected in field. The samples of T. chinensis(harvested from Morus alba)and its M. alba host was taken as control substance. All samples were extracted by ultrasonic extraction in 70% ethanol. Chromatographic separation was performed on an ACQUITY UPLC HSS T3 C_(18)(2.1 mm×100 mm,1.8 µm)column at 40 ℃. Gradient elution was applied, and the mobile phase was consisted of 0.1% formic acid water and acetonitrile. The 0.5 µL of sample solution was injected and the flow rate of the mobile phase was kept at 0.6 mL·min~(-1) in each run. It was done to identify cardiac glycosides and explore the chemical composition correlation in T. chinensis and its N. indicum host by analyzing positive and negative ion mode mass spectrometry data, elemental composition, cardiac glycoside reference substance and searching related literatures. A total of 29 cardiac glycosides were identified, 28 of it belonged to N. indicum host, 5 belonged to T. chinensis(harvested from N. indicum host), none of cardiac glycoside was identified in T. chinensis(harvested from M. alba host). The result could provide a reference in evaluating the influence in T. chinensis medicine quality from host. It was rapid, accurate, and comprehensive to identify cardiac glycosides in T. chinensis and its N. indicum host by UPLC-Q-TOF-MS/MS.


Subject(s)
Cardiac Glycosides/analysis , Drugs, Chinese Herbal/chemistry , Loranthaceae/chemistry , Nerium/chemistry , Chromatography, High Pressure Liquid , Phytochemicals/analysis , Tandem Mass Spectrometry
19.
J Pharm Biomed Anal ; 174: 450-459, 2019 Sep 10.
Article in English | MEDLINE | ID: mdl-31220703

ABSTRACT

To evaluate the effect of the host plant on the quality of Loranthaceae species as medicinal raw material, ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) was used to identify cardiac glycosides in Nerium indicum and its parasitic plant species Taxillus chinensis and Scurrula parasitica. Samples were collected from N. indicum and these parasites, while Morus alba and its parasite T. chinensis and Osmanthus fragrans and its parasite S. parasitica were used as controls. Based on mass spectrometry data and elemental composition analysis of positive and negative ion modes, in combination with standard cardiac glycosides and relevant literature, cardiac glycosides in N. indicum and its parasites T. chinensis and S. parasitica were identified, and their correlations were analyzed. A total of 29 cardiac glycosides were identified, among which 28 were found in N. indicum parasitized by T. chinensis; 25 cardiac glycosides were identified in the same host under attack by S. parasitica; five cardiac glycosides were identified in both T. chinensis and S. parasitica, which grew parasitically on N. indicum, whereas no cardiac glycosides were identified in M. alba parasitized by T. chinensis, or in O. fragrans parasitized by S. parasitica. We conclude that UPLC-Q-TOF-MS/MS technology can identify cardiac glycosides in N. indicum and parasites T. chinensis and S. parasitica rapidly, accurately, and thoroughly. N. indicum will transfer its own cardiac glycosides to its parasites through the special host-parasite interaction. Our results provide a reference basis for evaluating the influence of the host plant on the quality of medicinal compounds obtained from Loranthaceae species.


Subject(s)
Cardiac Glycosides/chemistry , Loranthaceae/chemistry , Nerium/chemistry , Chromatography, High Pressure Liquid , Digitoxigenin/analysis , Doxorubicin/analogs & derivatives , Doxorubicin/analysis , Drugs, Chinese Herbal/chemistry , Flavonoids/chemistry , Molecular Structure , Plants, Medicinal/chemistry , Spectrometry, Mass, Electrospray Ionization , Tandem Mass Spectrometry
20.
Chem Commun (Camb) ; 55(50): 7151-7154, 2019 Jun 25.
Article in English | MEDLINE | ID: mdl-31119224

ABSTRACT

Herein, we, for the first time, report a high spin Co-Fe Prussian blue analogue (Co-Fe PBA) as a highly efficient Fenton-like catalyst for sulfate radical (SO4˙-) production. Our experiments and density functional theory (DFT) calculations show that the largely elongated SO4-OH bond length, strengthened adsorption and facilitated electron transfer for peroxymonosulfate (PMS) activation catalyzed by high-spin (HS) CoII are the main factors contributing to its excellent activity.

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