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1.
Biol Trace Elem Res ; 2021 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-34773147

RESUMO

As an essential trace element, appropriate boron supplementation can promote immune function of animals. To illustrate the effects of boron in a rat model, RNA-Seq was conducted for the RNA from duodenum after treatment with different concentration of boron in which boron was given in the form of boric acid. More than 47 million reads were obtained in 0, 10, and 320 mg/L boron (0, 57.21, and 1830.66 mg/L boric acid) treatment groups that produced 58 965 402, 48 607 328, and 46 760 660 clean reads, respectively. More than 95% of the clean reads were successfully matched to the rat reference genome and assembled to generate 32 662 transcripts. A total of 624 and 391 differentially expressed candidate genes (DEGs) were found between 0 vs.10 and 0 vs. 320 mg/L boron comparison groups. We also identified transcription start site, transcription terminal site, and skipped exons as the main alternative splicing events. GO annotations revealed most of DEGs were involved in the regulation of immune activity. The DEGs were enriched in influenza A, herpes simplex infection, cytosolic DNA-sensing pathway, and antigen processing and presentation signaling pathways. The expression levels of genes enriched in these signaling pathways indicate that lower doses of boron could achieve better effects on promoting immune response in the duodenum. These effects on the immune system appear to be mediated via altering the expression patterns of genes involved in the related signaling pathways in a dose-dependent pattern. These data provide more insights into the molecular mechanisms of immune regulation in rats in response to dietary boron treatment.

2.
Front Plant Sci ; 12: 767667, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34759949

RESUMO

Multiple C2 domain and transmembrane region proteins (MCTPs) are a group of evolutionarily conserved proteins and show emerging roles in mediating protein trafficking and signaling transduction. Although, several studies showed that MCTPs play important roles during plant growth and development, their biological functions in cotton remain largely unknown. Here, we identify and characterize 33 GhMCTP genes from upland cotton (Gossypium hirsutum) and reveal the diverse expression patterns of GhMCTPs in various tissues. We also find that GhMCTP7, GhMCTP12, and GhMCTP17 are highly expressed in the main stem apex, suggesting their possible roles in shoot development. Through analyzing different cotton species, we discover plant heights are closely related to the expression levels of GhMCTP7, GhMCTP12, and GhMCTP17. Furthermore, we silence the expression of GhMCTP genes using virus-induced gene silencing (VIGS) system in cotton and find that GhMCTP7, GhMCTP12, and GhMCTP17 play an essential role in shoot meristem development. GhMCTPs interact with GhKNAT1 and GhKNAT2 and regulate meristem development through integrating multiple signal pathways. Taken together, our results demonstrate functional redundancy of GhMCTPs in cotton shoot meristem development and provide a valuable resource to further study various functions of GhMCTPs in plant growth and development.

3.
J Neurosci ; 41(48): 9872-9890, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34725188

RESUMO

Oligodendrocytes are vulnerable to genetic and environmental insults and its injury leads to demyelinating diseases. The roles of ErbB receptors in maintaining the CNS myelin integrity are largely unknown. Here, we overactivate ErbB receptors that mediate signaling of either neuregulin (NRG) or epidermal growth factor (EGF) family growth factors and found their synergistic activation caused deleterious outcomes in white matter. Sustained ErbB activation induced by the tetracycline-dependent mouse tool Plp-tTA resulted in demyelination, axonal degeneration, oligodendrocyte precursor cell (OPC) proliferation, astrogliosis, and microgliosis in white matter. Moreover, there was hypermyelination before these inflammatory pathologic events. In contrast, sustained ErbB activation induced by another tetracycline-dependent mouse tool Sox10 +/rtTA caused hypomyelination in the corpus callosum and optic nerve, which appeared to be a developmental deficit and did not associate with OPC regeneration, astrogliosis, or microgliosis. By tracing the differentiation states of cells expressing tetracycline-controlled transcriptional activator (tTA)/reverse tTA (rtTA)-dependent transgene or pulse-labeled reporter proteins in vitro and in vivo, we found that Plp-tTA targeted mainly mature oligodendrocytes (MOs), whereas Sox10 +/rtTA targeted OPCs and newly-formed oligodendrocytes (NFOs). The distinct phenotypes of mice with ErbB overactivation induced by Plp-tTA and Sox10 +/rtTA consolidated their nonoverlapping targeting preferences in the oligodendrocyte lineage, and enabled us to demonstrate that ErbB overactivation in MOs induced necroptosis that caused inflammatory demyelination, whereas in OPCs induced apoptosis that caused noninflammatory hypomyelination. Early interference with aberrant ErbB activation ceased oligodendrocyte deaths and restored myelin development in both mice. This study suggests that aberrant ErbB activation is an upstream pathogenetic mechanism of demyelinating diseases, providing a potential therapeutic target.SIGNIFICANCE STATEMENT Primary oligodendropathy is one of the etiologic mechanisms for multiple sclerosis, and oligodendrocyte necroptosis is a pathologic hallmark in the disease. Moreover, the demyelinating disease is now a broad concept that embraces schizophrenia, in which white matter lesions are an emerging feature. ErbB overactivation has been implicated in schizophrenia by genetic analysis and postmortem studies. This study suggests the etiologic implications of ErbB overactivation in myelin pathogenesis and elucidates the pathogenetic mechanisms.

4.
Dalton Trans ; 50(45): 16519-16527, 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34610065

RESUMO

In this article, a new zinc-containing ionic liquid (IL) [HMMIm]2[ZnCl4] (HMMIm = 1-hexyl-2,3-dimethyl-imidazolium) is designed, which acts as a multifunctional source for the interfacial engineering of ZnS nanodots (NDs). Given the electrostatic interaction driven by the imidazolium cation, the steric effect of the alkyl chain, and the in situ released Zn ion from the IL, [HMMIm]2[ZnCl4] shows great advantages in controlling the formation of ZnS NDs. Based on this strategy, a nanocomposite consisting of homodispersed ZnS NDs anchored on sulfur/nitrogen dual-doped reduced graphene oxide (ZnS-NDs@SNG) is prepared. When evaluated as an anode material for lithium-ion batteries (LIBs), the nanocomposite delivers high reversible specific capacity, excellent high-rate performance, and superior cycling life. In particular, a discharge capacity of 648.1 mA h g-1 can be achieved at a high current density (10.0 A g-1) over 5000 cycles. Benefitting from the multifunctional IL and the simple synthesis protocol, the IL-assisted interfacial engineering strategy will enable a new avenue for the controllable synthesis of metal-sulfide-based anode materials.

5.
Opt Lett ; 46(20): 5228-5231, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34653159

RESUMO

Hot carriers play a significant role in applications of photovoltaics, photodetection, and photocatalysis. However, effective methods for observing the ultrafast dynamic processes of hot carriers are concentrated on the time domain, on which it is difficult and complex to operate. We propose a novel, to the best of our knowledge, and creative strategy to convert the time-domain dynamic process into a spatially thermal redistribution in suspended carbon nanotube fibers. The large average free path of photoinduced hot holes ensures a prominent offset of temperature distribution. The experimental results confirm the theory about electrically driven transport of hot holes, which has rarely been reported.

6.
BMC Ophthalmol ; 21(1): 345, 2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34556073

RESUMO

BACKGROUND: To investigate the relationships between motor fusion and sex, age and spherical equivalent (SE). METHODS: This observational study enrolled 243 healthy, nonstrabismic adults, including 94 men and 149 women aged 20 to 59 years. The subjects were divided into three groups according to SE: myopic, emmetropic and hyperopic groups. The subjects were also divided into four groups according to age: 20-29, 30-39, 40-49 and 50-59 years groups. Motor fusion was measured with a synoptophore, including subjective angle (SA), divergence, convergence and fusional vergence range (FVR). RESULTS: The mean values of divergence, convergence and FVR for the whole sample group were 9.72 ± 0.26°, 19.34 ± 0.54°, and 29.06 ± 0.62°, respectively. A higher value of divergence was found in the myopic group than in the emmetropic group (p < 0.05). SE and divergence were significantly different among age groups (all p < 0.05). In addition, linear regression analysis showed that SE was correlated with divergence (p = 0.003). Age was correlated with SE, divergence and FVR (p < 0.001, p = 0.005, p = 0.002, respectively). In addition, the proportion of SA being in the comfort zone (defined as the value of SA satisfying Percival's criterion) in the age groups was significantly different (χ2 = 8.283, p = 0.041). CONCLUSIONS: Motor fusion is associated with age and SE in the normal Chinese adult population.


Assuntos
Hiperopia , Miopia , Erros de Refração , Adulto , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Erros de Refração/epidemiologia , Adulto Jovem
7.
ACS Appl Mater Interfaces ; 13(34): 40562-40570, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34470106

RESUMO

Improving the light utilization and electron-hole separation efficiency plays a central role in photocatalysis for converting light energy to hydrogen energy. Herein, for the first time, a stable, highly dispersible discrete T4 [Cd3In17Se31]5- cluster is developed as a novel photosensitizer to sensitize TiO2 for photocatalytic hydrogen production. Compared with pristine TiO2 (near zero) and the T4 clusters (19.5 µmol g-1 h-1) that exhibit low hydrogen evolution activities, the T4/TiO2 composite, constructed from traces of 0.127 mol % T4 cluster-sensitized TiO2, exhibits a dramatically improved photocatalytic activity of 328.2 µmol g-1 h-1, highlighting that the photocatalytic efficiency strongly correlates with that of the T4 cluster. In the meantime, the T4/TiO2 composites are highly stable, remaining robust in a long-time test of 50 h for photocatalytic hydrogen production. Ultrafast transient absorption spectroscopy, in combination with electrochemical analyses, steady-state and time-resolved photoluminescence, and density functional theory calculations, indicates that the T4 cluster not only serve as a photosensitizer to absorb visible light but also form a heterojunction between the interface of the T4 cluster and TiO2 to accelerate electron injection. This work highlights the great potential of the stable and highly dispersed discrete metal chalcogenide clusters as high-efficiency photosensitizers for converting solar energy to chemical energy.

8.
Environ Sci Pollut Res Int ; 28(44): 62306-62320, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34191263

RESUMO

Progesterone, an endocrine-disrupting chemical, has been frequently detected in wastewater for decades, posing a serious threat to ecological and human health. However, it is still a challenge to achieve the effective detection of progesterone in complex matrices water samples. In this study, a novel adsorbent CNT@CS/P(MAA) was prepared by grafting methacrylic polymers on the surface of modified carbon nanomaterials. Compared with other reported materials, the hybrid carbon nanomaterial could selectively identify the progesterone in the complex industrial pharmaceutical wastewater, and its adsorption performance is almost independent of the pH and environmental temperature. In addition, this nanomaterial could be reused with a good recovery rate. The prepared nanomaterials were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, nitrogen adsorption and desorption experiments, and thermogravimetric analysis. The results confirmed that the methacrylic polymers and chitosan layer were successfully grafted on the surface of carbon nanotubes. Adsorption isotherms, adsorption kinetics, and selectivity tests showed that CNT@CS/P(MAA) had a high adsorption capacity (44.45 mg·g-1), a fast adsorption rate and a satisfied selectivity for progesterone. Then, CNT@CS/P(MAA) was used as solid phase extraction sorbent and combined with HPLC to enrich progesterone from the wastewater samples. Under the optimum conditions, a good linearity was obtained with the correlation coefficient was 0.9998, and the limit of detection was 0.003 ng·mL-1. Therefore, this method could be used for the selective and effective detection of progesterone in industrial wastewater with complex substrates and provided a new method for the detection of progesterone in other environmental waters.


Assuntos
Nanotubos de Carbono , Preparações Farmacêuticas , Poluentes Químicos da Água , Adsorção , Humanos , Progesterona , Extração em Fase Sólida , Espectroscopia de Infravermelho com Transformada de Fourier , Águas Residuárias , Poluentes Químicos da Água/análise
9.
Exp Ther Med ; 21(4): 371, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33732344

RESUMO

It has been shown that flickering light can affect the development of eyeballs. However, the exact mechanism remains unclear. The ERK1/2-MMP-2 pathway is a classic pathway involved in the modulation of the extracellular matrix (ECM) in cancer tissues. However, to the best of our knowledge, the role of this pathway in modulating the scleral ECM in myopia has not been previously examined. The present study aimed to determine the effects of the ERK1/2-MMP-2 pathway on the formation of flickering light-induced myopia (FLM). Guinea pigs were raised under illumination at a flash rate of 0.5 Hz for 6 weeks to induce FLM. Peribulbar injections of dimethylsulfoxide or PD98059 (an inhibitor of phospho-ERK1/2) were administered starting at the third week of FLM modeling. Refraction was measured prior to and following treatments. The thickness of the posterior sclera (PS) was measured under a light microscope following H&E staining. The mRNA levels of MMP-2 were detected by the reverse transcription-quantitative PCR assay. The expression levels of MMP-2 and ERK1/2 were assayed by western blot and immunohistochemical analyses. Following 6 weeks of treatment, the refraction of the FLM group became more myopic compared with that of the control group, while PD98059 treatment inhibited the changes noted in the refraction. A marked reduction in the thickness of PS was observed in the FLM group, while PD98059 inhibited the remodeling of PS. In addition, the expression levels of MMP-2 and protein levels of phospho-ERK1/2 were increased in the FLM group, while PD98059 significantly inhibited MMP-2 mRNA and protein levels. These results indicated that ERK1/2-MMP-2 may be involved in the formation of FLM in guinea pigs by regulating the remodeling of PS.

10.
Dalton Trans ; 50(8): 2815-2823, 2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33533353

RESUMO

Silicon (Si) has recently aroused great interest as a promising anode material for lithium-ion batteries with high energy density due to its high theoretical capacity. However, the application of Si remains a great challenge owing to its extremely large volume change during cycling, thus resulting in dramatic capacity fading. Herein, a novel structure design of the porous Si/C composite with Si nanoparticles embedded in the carbon nanosheets has been successfully achieved by using a recrystallized NaCl template with appropriate particle size. The outermost sheet-like carbon coating can improve the electronic conductivity and contribute to the formation of a more stable solid-electrolyte interphase layer, while the inner void space effectively buffers the volume expansion of Si during the lithiation process. In addition, only a structure with Si particles anchored on the surface of carbon nanosheets has been obtained by using a commercial NaCl template with large particle size, confirming the effective regulation of the NaCl template in the microstructure and thus the electrochemical properties of the Si/C composites. As expected, benefiting from the combination of the outermost carbon coating and recrystallized NaCl-derived porous structure, the as-obtained Si/C composite demonstrates attractive cycling stability and rate performance as an anode material for lithium-ion batteries.

11.
Int Ophthalmol ; 41(3): 835-843, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33184676

RESUMO

PURPOSE: To evaluate the time trend of axial length (AL) and associated factors in 4- and 5-year-old children in Shanghai from 2013 to 2019. METHODS: This was a 7-year observational study of 985 four-year-old and 1059 five-year-old children in Shanghai. AL, horizontal and vertical corneal curvature, spherical equivalent (SE), and body height and weight were measured. Furthermore, a questionnaire was collected, including time outdoors and bad eyesight habits. RESULTS: In 4-year-old children, no significant difference was found in AL (P = 0.526), but significant differences were observed in SE (P = 0.001), horizontal corneal curvature (P = 0.006), vertical corneal curvature (P = 0.004), height (P < 0.001), and weight (P = 0.022) from 2013 to 2019. In 5-year-old children, no significant differences were found in AL (P = 0.304), SE (P = 0.200), or weight (P = 0.292), but significant differences were observed in horizontal corneal curvature (P = 0.040), vertical corneal curvature (P = 0.015), and height (P < 0.001) from 2013 to 2019. Multivariate analyses revealed that AL was mainly significantly associated with boys and time outdoors in the 4- and 5-year-old children. CONCLUSIONS: The AL of 4- and 5-year-old children remained relatively stable in Shanghai from 2013 to 2019. Longitudinal studies are needed to confirm the relationship between AL elongation and environmental risk factors.


Assuntos
Comprimento Axial do Olho , Córnea , Pré-Escolar , China/epidemiologia , Humanos , Estudos Longitudinais , Masculino , Refração Ocular
12.
Biol Trace Elem Res ; 199(1): 205-215, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32319072

RESUMO

Boron is an essential trace element for animals. Appropriate boron supplementation can produce beneficial effects on the animal body, while a high dose of boron has adverse and even toxic effects. Our aim was to investigate the impact of different doses of boron on the microstructure of duodenum in rats, expression of secretory immunoglobulin A (SIgA) and tight junction protein, cell proliferation and apoptosis. Eighty newly weaned clean Sprague-Dawley (SD) rats were given distilled water supplemented with 0, 10, 20, 40, 80, 160, 320, and 640 mg/L of boron for 60 days. We found that supplementation of 40 and 80 mg/L boron could increase the height of duodenal villi and the crypt depth, the number of intraepithelial lymphocytes (IELs) and goblet cells, the expression of SIgA, Zonula occludens-1 (ZO-1) and occludin, and proliferating cell nuclear antigen (PCNA) in duodenum of rats; decrease expression of Caspase-3 mRNA and the number of Caspase-3-positive cells, but supplementation of 320 and 640 mg/L boron could have the opposite effect in these indexes. The results showed that supplemented with 40 and 80 mg/L of boron could improve the structure and function of duodenum, while supplemented with 320-640 mg/L had a significant inhibitory effect.


Assuntos
Boro , Proteínas de Junções Íntimas , Animais , Apoptose , Boro/farmacologia , Proliferação de Células , Duodeno , Imunidade , Mucosa Intestinal , Ratos , Ratos Sprague-Dawley
13.
Food Chem Toxicol ; 146: 111838, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33137424

RESUMO

Supplementing different quantities of boron can significantly affect immune function in rat spleen, but the mechanism of action behind this effect remains unclear. Our purpose was to study the involvement of the estrogen membrane receptor GPR30 in the effect of boron on the proliferation, apoptosis, and immune function of rat spleen lymphocytes. Results showed that the addition of 0.4 mmol/L boron had a beneficial effect on the immune function and proliferation of spleen lymphocytes, but the addition of 40 mmol/L boron had opposite effect. After using G-15 to selectively inhibit GPR30, the proportions of CD4+ and CD8+ T cells, the content of IL-2 and IFN-γ, and the expression of PCNA protein were significantly decreased, while lymphocyte apoptosis rate increased significantly (p < 0.05 or p < 0.01). After G-15 treatment, the addition of 0.4 mmol/L boron had no effects on T cell subsets, lymphocyte proliferation, PCNA protein expression, and IgG and cytokine content (P > 0.05), while the addition of 40 mmol/L boron did not change the effects on lymphocyte subsets, proliferation and apoptosis. The results suggested that GPR30 mediates the effects of 0.4 mmol/L boron boron on the proliferation, apoptosis and immune function of spleen lymphocytes.


Assuntos
Apoptose/efeitos dos fármacos , Boro/farmacologia , Proliferação de Células/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Receptores Acoplados a Proteínas G/metabolismo , Baço/citologia , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Imunidade Celular , Linfócitos/fisiologia , Ratos , Receptores Acoplados a Proteínas G/genética
14.
ACS Appl Mater Interfaces ; 12(45): 50763-50771, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33136365

RESUMO

Graphene has excellent electrical, optical, thermal, and mechanical properties that make it an ideal optoelectronic material. However, it still has some problems, such as a very low light absorption rate, which means it cannot meet the application requirements of high-performance optoelectronic devices. Here, we produce a high-responsivity photodetector based on a monolayer graphene/RbAg4I5 composite nanostructure. With the aid of poly(methyl methacrylate), we suspend the monolayer graphene on a hollow carving groove with a width of 100 µm. A RbAg4I5 film evaporated on the back of the graphene causes the composite nanostructure to generate a large photocurrent under periodic illumination. Experimental results show that the dissociation and recombination of ion-electron bound states (IEBSs) are responsible for the excellent photoresponse. The device has very high (>1 A W-1) responsivity in wide-band illumination wavelength from 375 nm to 808 nm, especially at 375 nm, where it shows a responsivity of up to ∼5000 A W-1. We designed the dimensions of the carving groove to allow the light spot to cover the entire groove, and we cut the graphene sheet to match the length of the carving groove. With the structural optimizations, the energy of light can be used more efficiently to dissociate the IEBSs, which greatly improves the photoresponse of optoelectronic devices based on the proposed monolayer graphene/RbAg4I5 composite nanostructure.

15.
Chempluschem ; 85(11): 2487-2498, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33215856

RESUMO

Discrete supertetrahedral Tn chalcogenido clusters, which can be regarded as the smallest semiconductor quantum dots with precise chemical composition, have attracted considerable attention due to their outstanding photoluminescent, photoelectric, and photo/electrocatalytic properties. Such discrete molecular clusters are suitable for solution processing towards functional materials and can be used as precursors for constructing open-framework chalcogenides. Traditionally they were synthesized hydro(solvo)thermally with molecular solvents (e. g. water or organic amines), while until recently imidazolium-based ionic liquids (ILs) were found suitable for their preparation acting as reactive solvent and stabilizer for molecular clusters. We discuss herein recent advances in the syntheses, crystal structures, and selected properties of discrete supertetrahedral Tn chalcogenido clusters obtained in ILs. In particular, the enhanced photocatalytic properties of monodispersed Tn clusters in solvents are highlighted.

16.
Biomed Res Int ; 2020: 1507561, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33015153

RESUMO

Objective: This study was aimed at observing the effect Jiao-Tai-Wan in menopausal depression. Methods: In this paper, we used ovariectomized mice subjected to chronic unpredictable stress as a menopausal depression model. After the chronic stress, mice were administrated with JTW (3.3 and 6.6mg/kg) and imipramine (10 mg/kg) for 14 days. On the 14th day, mice were subjected to the behavior test like the forced swim test, tail suspension test, and locomotor activity or were sacrificed to assess the protein changes in different brain regions. Results: The administration of JTW at doses of 3.3 and 6.6mg/kg (p.o.) significantly shortened the duration of immobility in forced swim and tail suspension tests. There was no obvious difference in locomotor activity among all the groups. The western blot analysis data indicated that treatment with JTW (3.3 and 6.6 mg/kg, p.o.) prominently increased the A1R protein and the downstream protein ERK1/2 levels in the prefrontal cortex and hippocampus. However, the administration of JTW did not influence c-Fos protein in either the prefrontal cortex or hippocampus. Conclusion: Our findings suggest that JTW plays a vital role in ameliorating menopausal depression symptoms in the A1R-ERK1/2 pathway in the prefrontal cortex and hippocampus.


Assuntos
Comportamento Animal/efeitos dos fármacos , Depressão/tratamento farmacológico , Transtorno Depressivo/tratamento farmacológico , Medicamentos de Ervas Chinesas/farmacologia , Estresse Psicológico/tratamento farmacológico , Animais , Depressão/metabolismo , Transtorno Depressivo/metabolismo , Modelos Animais de Doenças , Feminino , Elevação dos Membros Posteriores/fisiologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Imipramina/farmacologia , Locomoção/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos ICR , Ovariectomia/métodos , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Estresse Psicológico/metabolismo , Natação/fisiologia
17.
Chem Commun (Camb) ; 56(77): 11390-11393, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-32990293

RESUMO

We report for the first time a novel support of polyetheretherketone fiber for the synthesis of recyclable N-heterocyclic carbene (NHC) catalysts. The fiber catalysts were verified in nucleophilic acylation of fluorobenzenes with superior catalytic activities, and successfully recycled by a tiny pair of tweezers over 21 cycles with minimal loss of performance.

18.
Small ; 16(34): e2002046, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32697433

RESUMO

Main obstacles from the shuttle effect and slow conversion rate of soluble polysulfide compromise the sulfur utilization and cycling life for lithium sulfur (Li-S) batteries. In pursuit of a practically viable high performance Li-S battery, a separator configuration (CoS2 /HPGC/interlayer) as efficient polysulfide trapping barrier is reported. This configuration endows great advantages, particularly enhanced conductivity, promoted polysulfide trapping capability, accelerated sulfur electrochemistry, when using the functional interlayer for Li-S cells. Attributed to the above merits, such cell shows excellent cyclability, with a capacity of 846 mAh g-1 after 250 cycles corresponding to a high capacity retention of 80.2% at 0.2 C, and 519 mAh g-1 after 500 cycles at 1C (1C = 1675 mA g-1 ). In addition, the optimized separator exhibits a high initial areal capacity of 4.293 mAh cm-2 at 0.1C. Moreover, with CoS2 /HPGC/interlayer, the sulfur cell enables a low self-discharge rate with a very high capacity retention of 97.1%. This work presents a structural engineering of the separator toward suppressing the dissolution of soluble Li2 Sn moieties and simultaneously promoting the sulfur conversion kinetics, thus achieving durable and high capacity Li-S batteries.

19.
Nanotechnology ; 31(45): 455201, 2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-32717725

RESUMO

A macroscopic silver nanowire (AgNW) network is grown by solid state ionics method. The ion flow during growth of the AgNW network is controlled by maintaining a current in the order of 10-7 A. Scanning electron microscopy (SEM) analysis reveals that the growth direction of AgNWs in the network is irregular and spread evenly in all directions and the nanowires are 40-160 nm in diameter. The microcosmic mechanism of silver nanostructures grown by the solid state ionics method is established by real time and in situ SEM analysis of the growth process of the AgNW networks. To study the photoelectric properties of the network, a self-supported AgNW network sample (∼1 mm wide and 8 mm long) is irradiated with lasers of different wavelengths of 375, 405, 532, 633, 808, and 1064 nm and 10.6 µm, and changes in the current between the two ends of the sample are recorded. The network displays negative photoconductance effect, and the maximum light responsivity is 43 mA W-1. The network displays light responsivity in the ultraviolet light-to-mid-infrared light region, with response times of tens of milliseconds. These findings indicate that the AgNW network has broad application prospect in ultra-wide spectrum photoelectric detection.

20.
Nanoscale ; 12(23): 12336-12345, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32515461

RESUMO

Charge transfer and surface photocatalytic reactions are two crucial factors that determine the efficiency of photocatalysts in converting light energy to hydrogen energy. Herein, a fast and green strategy composed of a one-pot microwave-assisted solvothermal synthesis followed by a heat treatment process is developed for synthesizing In2S3/mesoporous TiO2 nanocomposites, using a mixture of tetra-butyl titanate, H2O, In-S-ionic liquid precursor solution (In-S-ILs) and [Bmim]Cl as the reactants. The ionic liquid cations act not only as a microwave absorbent during the solvothermal process, but also as a morphology-controlling agent via a dissolution-recrystallization process, leading to the formation of nanocomposites consisting of small and uniform sized In2S3 and mesoporous TiO2. The optimum In2S3/mesoporous TiO2 nanocomposite with an In2S3 content of 1.01 mol% exhibits a H2 evolution rate of 637.9 µmol g-1 h-1, which is over 10 times that of commercial P25, and is 5.7 and 2.6 times that of neat mesoporous TiO2 and the milled In2S3/mesoporous TiO2 with the same component, respectively. The improved H2 evolution activity is predominantly attributed to the small size of In2S3, special mesoporous structure of TiO2, and their intimate heterojunction interface, which guaranteed effective charger transfer between In2S3 and mesoporous TiO2 as well as abundant active sites for photocatalytic reactions. This work provides a novel and simple strategy for obtaining special structures of semiconductor-based nanocomposites for efficient energy conversion.

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