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1.
Adv Sci (Weinh) ; : e2401314, 2024 Jun 14.
Article in English | MEDLINE | ID: mdl-38877663

ABSTRACT

Organic anodes have emerged as a promising energy storage medium in proton ion batteries (PrIBs) due to their ability to reversibly accommodate non-metallic proton ions. Nevertheless, the currently available organic electrodes often encounter dissolution issues, leading to a decrease in long-cycle stability. In addition, the inherent potential of the organic anode is generally relatively high, resulting in low cell voltage of assembled PrIBs (<1.0 V). To address these challenges, a novel long-period stable, low redox potential biphenylzine derivative, [2,2'-biphenazine]-7,7'-tetraol (BPZT) is explored, from the perspective of molecular symmetry and solubility, in conjunction with the effect of the molecular frontier orbital energy levels on its redox potential. Specifically, BPZT exhibited a low potential of 0.29 V (vs SHE) and is virtually insoluble in 2 m H2SO4 electrolyte during cycling. When paired with MnO2@GF or PbO2 cathodes, the resulting PrIBs achieve cell voltages of 1.07 V or 1.44 V, respectively, and maintain a high capacity retention of 90% over 20000 cycles. Additionally, these full batteries can operate stably at a high mass loading of 10 mgBPZT cm-2, highlighting their potential toward long-term energy storage applications.

2.
ChemSusChem ; 16(19): e202300658, 2023 Oct 06.
Article in English | MEDLINE | ID: mdl-37491683

ABSTRACT

Aqueous zinc ion batteries (AZIBs) are gaining popularity as advanced energy storage devices that are economical, safe, and use resource-abundant storage options. In this study, we have synthesized a bipolar phenothiazine organic scaffold known as 3,7-bis(melaminyl)phenothiazin-5-ium iodide (PTDM), which is obtained by undergoing nucleophilic substitution through phenothiazinium tetraiodide hydrate (PTD) and melamine. Electrochemical results indicate that PTDM can act as a high-potential cathode material for rechargeable AZIBs. In detail, the aqueous PTDM//Zn full cell exhibits a high average voltage of approximate 1.13 V, along with a specific capacity of 118.3 mAh g-1 at 0.1 A g-1 . Furthermore, this demonstrated cell displays moderate long-term cycling stability over 6400 cycles, which is encouraging and suggests potential for developing advanced organic electrode materials for rechargeable AZIBs.

3.
Small Methods ; 7(10): e2300606, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37452266

ABSTRACT

Aqueous zinc-ion batteries (AZIBs) are expected to be an attractive alternative in advanced energy storage devices due to large abundance and dependable security. Nevertheless, the undesirable energy density and operating voltage still hinder the development of AZIBs, which is intimately associated with the fundamental properties of the cathode. In this work, polyvinylpyrrolidone (PVP) intercalated Mn0.07 VOx (PVP-MnVO) with a large interlayer spacing of 13.5 Å (against 12.5 Å for MnVO) synthesized by a facile hydrothermal method is adopted for the cathode in AZIBs. The experimental results demonstrate that PVP-MnVO with expanded interlayer spacing provides beneficial channels for the rapid diffusion of Zn2+ , resulting in a high discharge capacity of 402 mAh g-1 at 0.1 A g-1 , superior to that of MnVO (275 mAh g-1 at 0.1 A g-1 ). Meanwhile, the PVP molecule remains in the layer structure as a binder/pillar, which can maintain its structural integrity well during the charging/discharging process. Consequently, PVP-MnVO cathode exhibits superior rate capability and cycling stability (89% retention after 4300 cycles at 10 A g-1 ) compared to that of MnVO (≈51% retention over 500 cycles at 2 A g-1 ). This work proposes a new approach to optimize the performance of vanadium-based electrode materials in AZIBs.

4.
Medicine (Baltimore) ; 102(20): e33679, 2023 May 19.
Article in English | MEDLINE | ID: mdl-37335719

ABSTRACT

This study aimed to investigate the application value of an interactive micro class on occupational protection in the operating room for nursing interns. Using a cluster sampling approach, 200 junior college nursing interns were selected as participants at our hospital, who were practicing from June 2020 to April 2021. They were randomly assigned to either the observation group or the control group, with 100 participants in each. Data on teaching-related evaluation indicators, including clarity of teaching objectives, learning atmosphere, rational use of learning resources, effectiveness of teaching process regulation, and degree of students' participation in activities, were collected for both groups. Additionally, the scores of occupational protection assessment in the operating room, which encompassed physical, chemical, biological, environmental, and physiological and psychological factors, were also recorded. The comparative analysis of teaching-related evaluation indicators between the 2 groups revealed statistically significant differences. Specifically, significant differences were found between the 2 groups in the clarity of teaching objectives (P = .007), learning atmosphere (P < .001), rational use of learning resources (P < .001), effectiveness of teaching process regulation (P = .01), and degree of students' participation in activities (P < .001). Furthermore, the scores of all items in the observation group were higher than those in the control group. Additionally, the comparison results of the scores of the occupational protection assessment in the operating room between the 2 groups showed that while there was no statistically significant difference between the 2 groups before the intervention (P > .05). However, after the intervention, statistically significant differences were found between the 2 groups in physical (P < .001), chemical (P = .001), biological (P < .001), environmental (P < .001), and physiological and psychological factors (P < .001). Additionally, the scores of all items in the observation group were higher than those in the control group. The implementation of the interactive micro class enhanced the quality of teaching related to occupational protection in the operating room for interning nurses, thus verifying its benefits in clinical teaching practices.


Subject(s)
Operating Rooms , Students, Nursing , Humans , Learning , Curriculum , Hospitals , Physical Examination , Students, Nursing/psychology
5.
Front Microbiol ; 13: 996930, 2022.
Article in English | MEDLINE | ID: mdl-36274747

ABSTRACT

Coconut oil cake (COC), a byproduct of oil extraction, contains high levels of cellulose. The aim of this study was to isolate a cellulose-degrading yeast from rotten dahlia that can effectively use COC as the only carbon source for cellulase secretion. Based on screening, Meyerozyma guillermondii CBS 2030 (M. guillermondii) was identified as a potential candidate, with the highest cellulolytic activity among the yeast strains isolated, with the carboxymethyl cellulase (CMCase) activity reaching 102.96 U/mL on day 5. The cellulose in COC samples was evaluated before and after degradation by M. guillermondii. Analysis based on field emission scanning electron microscopy (FESEM) revealed that the COC structure was changed significantly during the treatment, indicating effective hydrolysis. Fourier transform infrared spectroscopy (FTIR) of the modified functional groups indicated successful depolymerization of coconut cake. X-ray diffraction (XRD) and analysis of color differences established effective degradation of COC by M. guillermondii. The results demonstrate that M. guillermondii effectively secretes CMCase and degrades cellulose, which has important practical significance in COC degradation.

6.
Foods ; 11(5)2022 Mar 02.
Article in English | MEDLINE | ID: mdl-35267371

ABSTRACT

Alfalfa polysaccharides (AP) receive wide attention in the field of medicine, because of their anti-inflammatory property. However, AP has high molecular weight and poor water solubility, resulting in low biological activity. We wanted to obtain highly bioactive alfalfa polysaccharides for further research. Herein, we successfully synthesized highly substituted sulfated alfalfa polysaccharides (SAP) via the chlorosulfonic acid (CSA)-pyridine (Pyr) method, which was optimized using response surface methodology (RSM). Under the best reaction conditions, that is, the reaction temperature, time, and ratio of CSA to Pyr being 55 °C, 2.25 h, and 1.5:1, respectively, the maximum degree of substitution of SAP can reach up to 0.724. Fourier transform infrared spectroscopy also confirmed the existence of sulfonic acid groups on SAP. Despite the increased average molecular weight of SAP, its water solubility is improved, which is beneficial for its biological activity. Further in vitro results showed that SAP exhibited better antioxidant activity and antibacterial ability than AP. Besides, the former can efficiently enhance the viability of oxidatively stressed intestinal epithelial cells compared with the latter. Furthermore, SAP has the potential to inhibit obesity. It is concluded that sulfation modification could improve the antioxidant, antibacterial, bovine intestinal epithelial cells' proliferation-promoting, and the obesity inhibition abilities of AP. The improvement of AP biological activity may provide references for the utilization of plant extracts that have weaker biological activity.

7.
Adv Mater ; 32(16): e2000338, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32141139

ABSTRACT

The newly emerged aqueous Zn-organic batteries are attracting extensive attention as a promising candidate for energy storage. However, most of them suffer from the unstable and/or soluble nature of organic molecules, showing limited cycle life (≤3000 cycles) that is far away from the requirement (10 000 cycles) for grid-scale energy storage. Here, a new aqueous zinc battery is proposed by using sulfur heterocyclic quinone dibenzo[b,i]thianthrene-5,7,12,14-tetraone (DTT) as the cathode. The cell shows a high reversible capacity of 210.9 mAh gDTT -1 at 50 mA gDTT -1 with a high mass loading of 5 mgDTT cm-2 , along with a fast kinetics for charge storage. Electrochemical measurements, ex situ analyses, and density functional theory calculation successfully demonstrate that the DTT electrode can simultaneously store both protons (H+ ) and Zn2+ to form DTT2 (H+ )4 (Zn2+ ), where Zn2+ is bound to the carboxyl groups from the adjacent DTT molecules with improved stability. Benefitting from the improved molecular stability and the inherent low solubility of DTT and related discharge products, the DTT//Zn full cell exhibits a superlong life of 23 000 cycles with a capacity retention of 83.8%, which is much superior to previous reports.

8.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-829321

ABSTRACT

@#[Abstract] Objective: To investigate the effect of lncRNA SNHG15 targeting miR-153 on cell viability and apoptosis of breast cancer cells and its apoptotic mechanism. Methods:The expression of SNHG15 in breast cancer cell lines(MDA-MB-231, BT-549 and MCF-7) were detected by Real-time fluorescent quantitative PCR (qPCR). MDA-MB-231 cells were divided into control (Ctrl) group, si-NC group, si-SNHG15 group, si-SNHG15+anti-NC group and si-SNHG15+anti-miR-153 group. Cell viability and apoptosis rate were detected by MTT and Flow cytometry, respectively. The targeting relationship between SNHG15 and miR-153 was verified by Dual luciferase report gene system. Mitochondrial membrane potential fluorescent probe (JC-1) staining method was used to detect cell mitochondrial membrane potential. The expressions of mitochondrial apoptosis-related proteins (Bcl-2, Bax, caspase3, cleaved caspase3 [c-caspase3] and Cyt-C)were detected by Western blotting. Results: The expression of SNHG15 in breast cancer cells was significantly higher than that in human normal mammary epithelial MCF10A cells (P<0.01). There was a targeting relationship between SNHG15 and miR-153. Compared with the control group, the cell viability and mitochondrial membrane potential of MDA-MB-231 cells in si-SNHG15 group were decreased, while apoptosis rate was increased (all P<0.01); the expressions of Bcl-2 and caspase3 were decreased while expressions of Bax, c-caspase3 and Cyt-C were increased (all P<0.01). However, co-transfection of si-SNHG15 and anti-miR-153 significantly attenuated the effects of si-SNHG15 on cell viability, apoptosis, mitochondrial membrane potential and expressions of Bcl-2, Bax, caspase3, c-caspase3 and Cyt-C (all P<0.01). Conclusion: lncRNA SNHG15 can target miR-153 to induce apoptosis of MDA-MB-231 cells, and the mechanism may be related to the regulation of apoptosis of mitochondrial pathway.

9.
Nat Commun ; 10(1): 2513, 2019 06 07.
Article in English | MEDLINE | ID: mdl-31175299

ABSTRACT

Redox flow batteries are promising for large-scale energy storage, but some long-standing problems such as safety issues, system cost and cycling stability must be resolved. Here we demonstrate a type of redox flow battery that is based on all-polymer particulate slurry electrolytes. Micro-sized and uniformly dispersed all-polymer particulate suspensions are utilized as redox-active materials in redox flow batteries, breaking through the solubility limit and facilitating the application of insoluble redox-active materials. Expensive ion-exchange membranes are replaced by commercial dialysis membranes, which can simultaneously realize the rapid shuttling of H+ ions and cut off the migration of redox-active particulates across the separator via size exclusion. In result, the all-polymer particulate slurry redox flow batteries exhibit a highly reversible multi-electron redox process, rapid electrochemical kinetics and ultra-stable long-term cycling capability.

10.
ACS Nano ; 12(12): 12492-12502, 2018 Dec 26.
Article in English | MEDLINE | ID: mdl-30474962

ABSTRACT

Rechargeable magnesium (Mg) batteries assembled with dendrite-free, safe, and earth-abundant metal Mg anodes potentially have the advantages of high theoretical specific capacity and energy density. Nevertheless, owing to the large polarity of divalent Mg2+ ions, the insertion of Mg2+ into electrode materials suffers from sluggish kinetics, which seriously limit the performance of Mg batteries. Herein, we demonstrate an atomic substitution strategy for the controlled preparation of ultrathin black TiO2- x (B-TiO2- x) nanoflakes with rich oxygen vacancies (OVs) and porosity by utilizing ultrathin 2D TiS2 nanoflakes as precursors. We find out that the presence of OVs in B-TiO2- x electrode material can greatly improve the electrochemical performances of rechargeable Mg batteries. Both experimental results and density functional theory simulations confirm that the introduction of OVs can remarkably enhance the electrical conductivity and increase the number of active sites for Mg2+ ion storage. The vacancy-rich B-TiO2- x nanoflakes exhibit high reversible capacity and good capacity retention after long-term cycling at large current densities. It is hoped that this work can provide valuable insights and inspirations on the defect engineering of electrode materials for rechargeable magnesium batteries.

11.
Adv Mater ; 30(32): e1802563, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29939428

ABSTRACT

Rechargeable magnesium batteries have attracted increasing attention due to the high theoretical volumetric capacities, dendrite formation-free characteristic and low cost of Mg metal anodes. However, the development of magnesium batteries is seriously hindered by the lack of capable cathode materials with long cycling life and fast solid-state diffusion kinetics for highly-polarized divalent Mg2+ ions. Herein, vanadium tetrasulfide (VS4 ) with special one-dimensional atomic-chain structure is reported to be able to serve as a favorable cathode material for high-performance magnesium batteries. Through a surfactant-assisted solution-phase process, sea-urchin-like VS4 nanodendrites are controllably prepared. Benefiting from the chain-like crystalline structure of VS4 , the S22- dimers in the VS4 nanodendrites provide abundant sites for Mg2+ insertion. Moreover, the VS4 atomic-chains bonded by weak van der Waals forces are beneficial to the diffusion kinetics of Mg2+ ions inside the open channels of VS4 . Through a series of systematic ex situ characterizations and density functional theory calculations, the magnesiation/demagnesiation mechanism of VS4 are elucidated. The VS4 nanodendrites present remarkable performance for Mg2+ storage among existing cathode materials, exhibiting a remarkable initial discharge capacity of 251 mAh g-1 at 100 mA g-1 and an impressive long-term cyclability at large current density of 500 mA g-1 (74 mAh g-1 after 800 cycles).

12.
ACS Appl Mater Interfaces ; 10(7): 6084-6089, 2018 Feb 21.
Article in English | MEDLINE | ID: mdl-29417816

ABSTRACT

An efficient self-standing hydrogen evolution electrode was prepared by in situ growth of stacked ultrathin TiO2/MoS2 heterolayers on carbon paper (CP@TiO2@MoS2). Owing to the high overall conductivity, large electrochemical surface area and abundant active sites, this novel electrode exhibits an excellent performance for hydrogen evolution reaction (HER). Remarkably, the composite electrode shows a low Tafel slope of 41.7 mV/dec, and an ultrahigh cathodic current density of 550 mA/cm2 at a very low overpotential of 0.25 V. This work presents a new universal strategy for the construction of effective, durable, scalable, and inexpensive electrodes that can be extended to other electrocatalytic systems.

13.
J Am Chem Soc ; 139(40): 14009-14012, 2017 10 11.
Article in English | MEDLINE | ID: mdl-28933843

ABSTRACT

The emergence of perovskite solar cells (PSCs) has generated enormous interest in the photovoltaic research community. Recently, cesium metal halides (CsMX3, M = Pb or Sn; X = I, Br, Cl or mixed halides) as a class of inorganic perovskites showed great promise for PSCs and other optoelectronic devices. However, CsMX3-based PSCs usually exhibit lower power conversion efficiencies (PCEs) than organic-inorganic hybrid PSCs, due to the unfavorable band gaps. Herein, a novel mixed-Pb/Sn mixed-halide inorganic perovskite, CsPb0.9Sn0.1IBr2, with a suitable band gap of 1.79 eV and an appropriate level of valence band maximum, was prepared in ambient atmosphere without a glovebox. After thoroughly eliminating labile organic components and noble metals, the all-inorganic PSCs based on CsPb0.9Sn0.1IBr2 and carbon counter electrodes exhibit a high open-circuit voltage of 1.26 V and a remarkable PCE up to 11.33%, which is record-breaking among the existing CsMX3-based PSCs. Moreover, the all-inorganic PSCs show good long-term stability and improved endurance against heat and moisture. This study indicates a feasible way to design inorganic halide perovskites through energy-band engineering for the construction of high-performance all-inorganic PSCs.

14.
Nanoscale ; 9(33): 11841-11845, 2017 Aug 24.
Article in English | MEDLINE | ID: mdl-28792059

ABSTRACT

An efficient method to synthesize well-crystallized inorganic cesium lead halide perovskites (CsPbX3, X = I or Br) with high yield and high reproducibility was proposed. Notably, the as-prepared CsPbI3 in the yellow orthorhombic phase (y-CsPbI3) can be easily converted to the black cubic perovskite phase CsPbI3 (b-CsPbI3) after thermal annealing. Furthermore, two-terminal photodetectors and all-inorganic perovskite solar cells based on b-CsPbI3 were fabricated, exhibiting high performances.

16.
J Am Chem Soc ; 138(49): 15829-15832, 2016 12 14.
Article in English | MEDLINE | ID: mdl-27960305

ABSTRACT

The research field on perovskite solar cells (PSCs) is seeing frequent record breaking in the power conversion efficiency (PCE). However, organic-inorganic hybrid halide perovskites and organic additives in common hole-transport materials (HTMs) exhibit poor stability against moisture and heat. Here we report the successful fabrication of all-inorganic PSCs without any labile or expensive organic components. The entire fabrication process can be operated in ambient environment without humidity control (e.g., a glovebox). Even without encapsulation, the all-inorganic PSCs present no performance degradation in humid air (90-95% relative humidity, 25 °C) for over 3 months (2640 h) and can endure extreme temperatures (100 and -22 °C). Moreover, by elimination of expensive HTMs and noble-metal electrodes, the cost was significantly reduced. The highest PCE of the first-generation all-inorganic PSCs reached 6.7%. This study opens the door for next-generation PSCs with long-term stability under harsh conditions, making practical application of PSCs a real possibility.

17.
Nanoscale ; 8(35): 16017-25, 2016 Sep 21.
Article in English | MEDLINE | ID: mdl-27545846

ABSTRACT

Here we report a facile one-step solution-phase process to directly grow ultrathin MoS2 nanofilms on a transparent conductive glass as a novel high-performance counter electrode for dye-sensitized solar cells. After an appropriate reaction time, the entire surface of the conductive glass substrate was uniformly covered by ultrathin MoS2 nanofilms with a thickness of only several stacked layers. Electrochemical impedance spectroscopy and cyclic voltammetry reveal that the MoS2 nanofilms possess excellent catalytic activity towards tri-iodide reduction. When used in dye-sensitized solar cells, the MoS2 nanofilms show an impressive energy conversion efficiency of 8.3%, which is higher than that of a Pt-based electrode and very promising to be a desirable alternative counter electrode. Considering their ultrathin thickness, superior catalytic activity, simple preparation process and low cost, the as-prepared MoS2 nanofilms with high photovoltaic performance are expected to be widely employed in dye-sensitized solar cells.

18.
Chemistry ; 20(45): 14614-8, 2014 Nov 03.
Article in English | MEDLINE | ID: mdl-25266337

ABSTRACT

Two-dimensional covalent organic frameworks (2D COFs) provide a unique platform for the molecular design of electronic and optoelectronic materials. Here, the synthesis and characterization of an electroactive COF containing the well-known tetrathiafulvalene (TTF) unit is reported. The TTF-COF crystallizes into 2D sheets with an eclipsed AA stacking motif, and shows high thermal stability and permanent porosity. The presence of TTF units endows the TTF-COF with electron-donating ability, which is characterized by cyclic voltammetry. In addition, the open frameworks of TTF-COF are amenable to doping with electron acceptors (e.g., iodine), and the conductivity of TTF-COF bulk samples can be improved by doping. Our results open up a reliable route for the preparation of well-ordered conjugated TTF polymers, which hold great potential for applications in fields from molecular electronics to energy storage.


Subject(s)
Heterocyclic Compounds/chemistry , Benzaldehydes/chemistry , Electrochemistry , Molecular Conformation , X-Ray Diffraction
19.
Chem Commun (Camb) ; 50(76): 11162-4, 2014 Oct 04.
Article in English | MEDLINE | ID: mdl-25111246

ABSTRACT

We report a new approach to construct covalent porphyrinic cages with different spacer lengths, in which the cage compounds have been conveniently synthesized in quantitative yields, via DABCO-templated imine condensation reactions.


Subject(s)
Heterocyclic Compounds, 2-Ring/chemistry , Imines/chemistry , Porphyrins/chemical synthesis , Models, Molecular , Molecular Structure , Porphyrins/chemistry
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