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1.
Angew Chem Int Ed Engl ; : e202406292, 2024 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-38780997

RESUMEN

Aqueous Zn-ion batteries are an attractive electrochemical energy storage solution for their budget and safe properties. However, dendrites and uncontrolled side reactions in anodes detract the cycle life and energy density of the batteries.Grain boundaries in metals are generally considered as the source of the above problems but we present a diverse result. This study introduces an ultra-high proportion of grain boundaries on zinc electrodes through femtosecond laser bombardment to enhance stability of zinc metal/electrolyte interface.The ultra-high proportion of grain boundaries promotes the homogenization of zinc growth potential, to achieve uniform nucleation and growth, thereby suppressing dendrite formation. Additionally, the abundant active sites mitigate the side reactions during the electrochemical process. Consequently, the 15-µm-Fs-Zn||MnO2 pouch cell achieves an energy density of 249.4 Wh kg-1 and  operates for over 60 cycles at a depth-of-discharge of 23%. The recognition of the favorable influence exerted by UP-GBs paves a new way for other metal batteries.

2.
Nat Commun ; 15(1): 3354, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38637529

RESUMEN

The discovery of Mn-Ca complex in photosystem II stimulates research of manganese-based catalysts for oxygen evolution reaction (OER). However, conventional chemical strategies face challenges in regulating the four electron-proton processes of OER. Herein, we investigate alpha-manganese dioxide (α-MnO2) with typical MnIV-O-MnIII-HxO motifs as a model for adjusting proton coupling. We reveal that pre-equilibrium proton-coupled redox transition provides an adjustable energy profile for OER, paving the way for in-situ enhancing proton coupling through a new "reagent"- external electric field. Based on the α-MnO2 single-nanowire device, gate voltage induces a 4-fold increase in OER current density at 1.7 V versus reversible hydrogen electrode. Moreover, the proof-of-principle external electric field-assisted flow cell for water splitting demonstrates a 34% increase in current density and a 44.7 mW/cm² increase in net output power. These findings indicate an in-depth understanding of the role of proton-incorporated redox transition and develop practical approach for high-efficiency electrocatalysis.

3.
J Alzheimers Dis ; 97(4): 1661-1672, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38306031

RESUMEN

Background: Rapidly growing healthcare demand associated with global population aging has spurred the development of new digital tools for the assessment of cognitive performance in older adults. Objective: To develop a fully automated Mini-Mental State Examination (MMSE) assessment model and validate the model's rating consistency. Methods: The Automated Assessment Model for MMSE (AAM-MMSE) was an about 10-min computerized cognitive screening tool containing the same questions as the traditional paper-based Chinese MMSE. The validity of the AAM-MMSE was assessed in term of the consistency between the AAM-MMSE rating and physician rating. Results: A total of 427 participants were recruited for this study. The average age of these participants was 60.6 years old (ranging from 19 to 104 years old). According to the intraclass correlation coefficient (ICC), the interrater reliability between physicians and the AAM-MMSE for the full MMSE scale AAM-MMSE was high [ICC (2,1)=0.952; with its 95% CI of (0.883,0.974)]. According to the weighted kappa coefficients results the interrater agreement level for audio-related items showed high, but for items "Reading and obey", "Three-stage command", and "Writing complete sentence" were slight to fair. The AAM-MMSE rating accuracy was 87%. A Bland-Altman plot showed that the bias between the two total scores was 1.48 points with the upper and lower limits of agreement equal to 6.23 points and -3.26 points. Conclusions: Our work offers a promising fully automated MMSE assessment system for cognitive screening with pretty good accuracy.


Asunto(s)
Disfunción Cognitiva , Humanos , Anciano , Anciano de 80 o más Años , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/psicología , Reproducibilidad de los Resultados , Pruebas Neuropsicológicas , Algoritmos , Cognición
4.
Mol Biol Rep ; 51(1): 351, 2024 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-38400865

RESUMEN

The nervous system possesses the remarkable ability to undergo changes in order to store information; however, it is also susceptible to damage caused by invading pathogens or neurodegenerative processes. As a member of nucleotide-binding oligomerization domain-like receptor (NLR) family, the NLRP6 inflammasome serves as a cytoplasmic innate immune sensor responsible for detecting microbe-associated molecular patterns. Upon activation, NLRP6 can recruit the adapter protein apoptosis-associated speck-like protein (ASC) and the inflammatory factors caspase-1 or caspase-11. Consequently, inflammasomes are formed, facilitating the maturation and secretion of pro-inflammatory cytokines such as inflammatory factors-18 (IL-18) and inflammatory factors-1ß (IL-1ß). Precise regulation of NLRP6 is crucial for maintaining tissue homeostasis, as dysregulated inflammasome activation can contribute to the development of various diseases. Furthermore, NLRP6 may also play a role in the regulation of extraintestinal diseases. In cells of the brain, such as astrocytes and neurons, NLRP6 inflammasome are also present. Here, the assembly and subsequent activation of caspase-1 mediated by NLRP6 contribute to disease progression. This review aims to discuss the structure and function of NLRP6, explain clearly the mechanisms that induce and activate NLRP6, and explore its role within the central and peripheral nervous system.


Asunto(s)
Inflamasomas , Enfermedades del Sistema Nervioso , Humanos , Inflamasomas/metabolismo , Citocinas/metabolismo , Caspasa 1/metabolismo , Apoptosis , Enfermedades del Sistema Nervioso/genética , Caspasas , Péptidos y Proteínas de Señalización Intracelular
5.
Aging Clin Exp Res ; 36(1): 37, 2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38345751

RESUMEN

BACKGROUND: Non-invasive brain stimulation (NIBS) is a burgeoning approach with the potential to significantly enhance cognition and functional abilities in individuals who have undergone a stroke. However, the current evidence lacks robust comparisons and rankings of various NIBS methods concerning the specific stimulation sites and parameters used. To address this knowledge gap, this systematic review and meta-analysis seek to offer conclusive evidence on the efficacy and safety of NIBS in treating post-stroke cognitive impairment. METHODS: A systematic review of randomized control trials (RCT) was performed using Bayesian network meta-analysis. We searched RCT in the following databases until June 2022: Cochrane Central Register of Controlled Trials (CENTRAL), PUBMED, and EMBASE. We compared any active NIBS to control in terms of improving cognition function and activities of daily living (ADL) capacity following stroke. RESULTS: After reviewing 1577 retrieved citations, a total of 26 RCTs were included. High-frequency (HF)-repetitive transcranial magnetic stimulation (rTMS) (mean difference 2.25 [95% credible interval 0.77, 3.66]) was identified as a recommended approach for alleviating the global severity of cognition. Dual-rTMS (27.61 [25.66, 29.57]) emerged as a favorable technique for enhancing ADL function. In terms of stimulation targets, the dorsolateral prefrontal cortex exhibited a higher ranking in relation to the global severity of cognition. CONCLUSIONS: Among various NIBS techniques, HF-rTMS stands out as the most promising intervention for enhancing cognitive function. Meanwhile, Dual-rTMS is highly recommended for improving ADL capacity.


Asunto(s)
Disfunción Cognitiva , Accidente Cerebrovascular , Estimulación Transcraneal de Corriente Directa , Humanos , Estimulación Transcraneal de Corriente Directa/métodos , Metaanálisis en Red , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/terapia , Encéfalo , Disfunción Cognitiva/etiología , Disfunción Cognitiva/terapia
6.
ACS Nano ; 18(6): 5068-5078, 2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-38289162

RESUMEN

Solid-state batteries based on lithium metal anodes are expected to meet safety challenges while maintaining a high energy density. One major challenge lies in the fast interface degradation between the electrolyte and the lithium metal. Herein, we propose a quasi-3D interphase on a garnet solid-state electrolyte (SSE) by introducing lithiophilic nanotrenches. The nanotrenches created by the lithiophilic nanowire array can induce the superfilling of lithium metal into the nanotrenches, resulting in a low interfacial resistance (4 Ω cm2). Moreover, the embedded lithium metal anode optimizes the lithium deposition/stripping behavior not limited at the Li-SSE interface (∼1-10 nm) but extended into the bulk lithium anode (∼10 µm), realizing a high critical current density of 1.8-2.0 mA cm-2 at room temperature (RT). The embedded lithium metal anode is further applied in Li||LiFePO4 solid-state batteries, demonstrating a high reversible areal capacity of ∼3.0 mAh cm-2 at RT.

7.
Int Immunopharmacol ; 124(Pt B): 110903, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37717319

RESUMEN

Depression is a common mental disease with disastrous effect on the health and wealth globally. Focusing on the role for inflammation and immune activation in the pathogenesis of depression, many tries have been taken into effect targeting at the blockage of inflammatory cytokines, among which interleukin- 6 (IL-6) and its receptor antagonist tocilizumab attracts more attention, with inconsistent findings. Moderate to severe depressive disorder (MSDD) patients were enrolled and the serum concentrations of IL-6 and tumor necrosis factor-α (TNF-α) measured, their correlation with the Hamilton Depression Rating Scale-24 (HAMD-24) scores was analyzed, and their role in discriminating MSDD patients from the health controls were evaluated. Meanwhile, a depression rat model was established by intraperitoneal injection of LPS, and tocilizumab was administrated doing 50 mg/kg via intravenous injection. The behavioral performance was observed, the serum concentration of IL-6, TNF-α, and C-reactive protein (CRP) was measured, and the protein expression of IL-6 and TNF-α in the hippocampus were also detected. The activity of the Hypothalamic-pituitary-adrenal (HPA) axis was observed, and the protein expression levels in the hippocampus were detected via western blot. Moreover, the immunofluorescence staining (IF) technique was used to investigate the co-location of IL-6 and neuron (MAP2), astrocyte (GFAP), or microglial (IBA-1). The results showed that the serum IL-6 level was significantly increased in the MSDD patients and lipopolysaccharide (LPS)-challenged rats, with a significant correlation with the HAMD-24 scores or struggling time in the FST and corticosterone (CORT) abundance. Results of ROC analysis showed a significant diagnosis value of IL-6 in discriminating MSDD patients or depression rats from the controls in the present study. Tocilizumab could relieve the depression-like behaviors induced by LPS, together with a normal abundance of serum CORT and hypothalamic CRH expression. Moreover, tocilizumab could alleviate the "inflammatory storm" and impaired hippocampal synaptic plasticity in LPS-challenged depression rats, inhibiting the hyperactivation of astrocyte and microglia, decreasing the peripheral and central abundance of IL-6, CRP, and TNF-α, and balancing the hippocampal expression levels of synaptic plasticity-associated proteins and key molecular in Wnt/ß-catenin signaling pathway. These results indicated a predictive role of IL-6 in discriminating depression from controls, and demonstrated an antidepressant effect of tocilizumab in LPS-challenged rats, targeting at the inflammatory storm and the subsequent impairments of hippocampal synaptic plasticity.


Asunto(s)
Interleucina-6 , Lipopolisacáridos , Humanos , Ratas , Animales , Interleucina-6/metabolismo , Lipopolisacáridos/farmacología , Factor de Necrosis Tumoral alfa/metabolismo , Antidepresivos/farmacología , Antidepresivos/uso terapéutico , Hipocampo , Biomarcadores/metabolismo , Depresión/tratamiento farmacológico , Depresión/metabolismo
8.
Adv Mater ; 35(47): e2304667, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37730093

RESUMEN

Aqueous zinc-ion batteries (AZIBs) offer promising prospects for large-scale energy storage due to their inherent abundance and safety features. However, the growth of zinc dendrites remains a primary obstacle to the practical industrialization of AZIBs, especially under harsh conditions of high current densities and elevated temperatures. To address this issue, a Janus separator with an exceptionally ultrathin thickness of 29 µm is developed. This Janus separator features the bacterial cellulose (BC) layer on one side and Ag nanowires/bacterial cellulose (AgNWs/BC) layer on the other side. High zincophilic property and excellent electric/thermal conductivity of AgNWs make them ideal for serving as an ion pump to accelerate Zn2+ transport in the electrolyte, resulting in greatly improved Zn2+ conductivity, deposition of homogeneous Zn nuclei, and dendrite-free Zn. Consequently, the Zn||Zn symmetrical cells with the Janus separator exhibit a stable cycle life of over 1000 h under 80 mA cm-2 and are sustained for over 600 h at 10 mA cm-2 under 50 °C. Further, the Janus separator enables excellent cycling stability in AZIBs, aqueous zinc-ion capacitors (AZICs), and scaled-up flexible soft-packaged batteries. This study demonstrates the potential of functional separators in promoting the application of aqueous zinc batteries, particularly under harsh conditions.

9.
Brain Sci ; 13(1)2023 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-36672137

RESUMEN

Background: Screening cognitive impairment is complex and not an appliance for early screening. Gait performance is strongly associated with cognitive impairment. Objectives: We aimed to explore gait indicators that could potentially screen cognitive dysfunction. Methods: A total of 235 subjects were recruited from June 2021 to June 2022. Four gait tasks, including the walking test, the timed "Up & Go" test (TUG), foot pressure balance (FPB), and one-legged standing with eyes closed test (OLS-EC), were performed. Moreover, in the walking test, participants were instructed to walk at their usual pace for the single-gait test. For the dual-task tests, participants walked at their usual pace while counting backward from 100 by 1s. The data were analyzed by the independent sample t-test, univariate and multivariate logistic regression, a linear trend, stratified and interaction analysis, the receiver operating characteristic (ROC) curve, and Pearson's correlations. Results: Among the 235 participants, 81 (34.5%) were men and 154 (65.5%) were women. The mean age of participants was 72 ± 7.836 years. The control, MCI, mild AD, and severe AD groups had means of 71, 63, 71, and 30, respectively. After adjusting for age, sex, education, and body mass index (BMI), the dual-task toe-off-ground angle (TOA) (odds ratio (OR) = 0.911, 95% confidence interval (CI): 0.847, 0.979), single-task TOA (OR = 0.904, 95% CI: 0.841−0.971), and the timed "Up & Go" time (TUGT) (OR = 1.515, 95% CI: 1.243−1.846) were significantly associated with an increased risk of cognitive impairment. In addition, the trend test and stratified analysis results had no significant differences (all p > 0.05). The area under the roc curve (AUC) values of TOA in the dual-task and TUGT were 0.812 and 0.847, respectively. Additionally, TOA < 36.75° in the dual-task, TOA < 38.90° in the single-task, and TUGT > 9.83 seconds (s) are likely to indicate cognitive impairment. The cognitive assessment scale scores were significantly correlated with TOA (all r > 0.3, p < 0.001) and TUGT (all r > 0.2), respectively. Conclusion: TOA and TUGT scores are, in some circumstances, associated with cognitive impairment; therefore, they can be used as simple initial screenings to identify patients at risk.

10.
Biomed Pharmacother ; 157: 114084, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36481407

RESUMEN

Cervical cancer (CC), as the most common malignant tumor of the female reproductive system, is infamous for its high morbidity and mortality rates. Its development and metastasis are intricate because numerous signaling pathways are involved. Since the cancer and the PI3K/Akt signaling pathway are closely intertwined, direct inhibition of either the PI3K/Akt pathway or its target genes and molecules may be remarkably constructive for treatment. Albeit remarkable advances in the treatment of CC, existing common anti-cancer medications are not without problems. These problems include myelotoxicity, cardiotoxicity, genotoxicity, and vasospasm, which are the most common and well-recognized toxicities associated with these medications. Therefore, it is necessary and urgent to develop novel, potent, secure, and more reasonably priced anticancer medications that are void of the above problems. Against this backdrop, Chinese medicine monomers have received more attention in recent years owing to their safety, low toxicity, few side effects, and anti-tumor properties. By regulating the PI3K/Akt signaling pathway, Chinese medicine monomers are effective not only in inhibiting CC growth, proliferation, apoptosis, invasion, migration, and reversing drug resistance but also in a variety of targets. Most previous earlier studies focused on the use of a single traditional Chinese medicine monomer to treat CC by regulating the PI3K/Akt signaling pathway rather than a combination of several such monomers. More importantly, to our knowledge, there has hardly been any study providing an exhaustive and comprehensive review of all the Chinese medicine monomers at CC. In response to this scarcity, we attempt in this paper to provide a comprehensive review of all the literature to date on traditional Chinese medicine monomers at cervical cancer, highlight the mechanisms and future prospects for their use in the prevention and treatment of cervical cancer.


Asunto(s)
Neoplasias del Cuello Uterino , Femenino , Humanos , Apoptosis , Línea Celular Tumoral , Proliferación Celular , Medicina Tradicional China , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/fisiología , Neoplasias del Cuello Uterino/tratamiento farmacológico , Neoplasias del Cuello Uterino/genética
11.
Artículo en Inglés | MEDLINE | ID: mdl-35783509

RESUMEN

Complementary and alternative medicine (CAM) encompasses a wide range of different non-mainstream therapies that have been increasingly used for the treatment or adjunct treatment of various ailments, with premature ovarian failure (POF) being one of the most common conditions treated with CAM. This review updates the progress of CAM in the treatment of POF, and we focus specifically on reviewing the evidence for the efficacy and mechanisms of a range of CAM treatments in POF, including single herbal medicines and their active ingredients, compound Chinese medicines, acupuncture and moxibustion, psychotherapy, exercise, vitamins, massage, and dietary supplements. According to the literature, CAM is very helpful for improving POF symptoms, and we hope to provide some instructive suggestions for clinical treatment and experimental research in the future. However, more clinical trials are needed to prove the safety of CAM.

12.
Artículo en Inglés | MEDLINE | ID: mdl-35399635

RESUMEN

Premature ovarian insufficiency (POI) is defined as a decline in ovarian function before the age of 40 and is one of the leading causes of infertility in women. The etiology is complex, and the pathogenesis is not clear. The main treatment is hormone replacement therapy, but a growing body of data confirms that such treatment can increase the risk of endometrial disease and cardiovascular disease. Complementary and alternative medicine (CAM) has been widely used in patients with POI due to its limited adverse reactions and high efficiency. According to literature reports, CAM therapy for POI mainly includes traditional Chinese medicine, acupuncture, psychotherapy, dietary supplements, and exercise therapy. This article reviews the application of CAM in the treatment of POI and attempts to determine the therapeutic effects and the mechanisms behind these effects based on existing clinical and experimental studies in order to provide theoretical support for the treatment of POI.

13.
Artículo en Inglés | MEDLINE | ID: mdl-35270761

RESUMEN

(1) Background: The COVID-19 pandemic has led to significant shifts in university students' lives, which could be displayed by social mentality, a psychosocial conception at the individual and social levels. This five-wave longitudinal study aims to evaluate the changing social mentality of university students during the peak and preventive-order phases of the pandemic in China and investigate the trends and differences in social-demographic variables. (2) Methods: The Bi-Dimensional Structure Questionnaire of Social Mentality (B-DSMQ) was used to collect data from March 2020 to January 2021. Five-wave surveys were administered to 1319 students from five universities using online questionnaires. Analysis of variance (ANOVA) was used to compare the changes in social mentality over time and covariate groups. Linear mixed models were used to explore the associations of overall social mentality with time and covariates. Post hoc analysis was implemented within subgroups, including university, major, grade, parenting style, and the harmonious degree of parents. (3) Results: Students' social mentality changed significantly from Waves 1 to 5 (p < 0.001). It fell to its lowest in the third survey, increased in the fourth survey, and peaked in the fifth survey. In all of the subgroups, the changing social mentality differed significantly over time (p < 0.001). The p-values between groups suggested that changing social mentality was significantly different regarding gender, residence, university, major, grade, student cadre, graduates, nuclear family, economic status, parenting styles, and the harmonious degree of parents' relationship (p < 0.001). (4) Conclusions: Social mentality among university students decreased during the peak of the pandemic before increasing in the contained-risk period. It was the lowest in June when students began to return to the pandemic-preventive campus from quarantined homes. Students living in provinces (except for Shandong) who were from high-level universities in 2016 and 2017 and who majored in medicine displayed a more negative social mentality. Students who were female, student cadres, non-graduates, and enjoying high socioeconomic status displayed a more positive social mentality. Further research is needed on the relationship between mental health and social mentality, specifically the associates and interventions for positive social mentality.


Asunto(s)
COVID-19 , Pandemias , COVID-19/epidemiología , China/epidemiología , Femenino , Humanos , Estudios Longitudinales , SARS-CoV-2 , Estudiantes/psicología , Universidades
14.
IEEE Trans Cybern ; 52(1): 582-593, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32275634

RESUMEN

Concepts have been adopted in concept-cognitive learning (CCL) and conceptual clustering for concept classification and concept discovery. However, the standard CCL algorithms are incapable of tackling continuous data directly, and some standard conceptual clustering methods mainly focus on the attribute information, ignoring the object information that is also important to improve clustering analysis and concept classification ability. Therefore, in this article, we present a novel concept learning method, called the fuzzy-based concept learning model (FCLM), to address these two issues by exploiting concept hierarchical relations in concept lattices. More specifically, we first show some new related notions for FCLM based on a regular fuzzy formal decision context; among these notions, the object-oriented and attribute-oriented fuzzy concept similarities are used to achieve the concept similarity measure in concept lattices. Moreover, a novel fuzzy concept learning framework is designed, and its corresponding learning algorithms are developed. Finally, we conduct some experiments on various real-world datasets to demonstrate that the proposed method can achieve the state-of-the-art classification performance among similarity-based learning methods. In addition, we further verify the effectiveness of our method in concept discovery on the MNIST dataset.

15.
ACS Appl Mater Interfaces ; 13(7): 8219-8228, 2021 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-33560816

RESUMEN

Solid-state lithium metal battery (SSLMB) is regarded as a safer energy storage system compared to the liquid one. The performance of the SSLMB depends on the cathode performance and the side reactions derived from the interface of the cathode and the electrolyte, which becomes much severe at high temperatures. Herein, we carried out a facile spray-drying route to prepare a CNTs/LiV3O8/Y2O3 (M-LVO-Y) composite. The synthesized cathode material exhibits an outstanding Li+ storage performance with a high reversible capacity of 279.9 mA h g-1 at 0.05 A g-1, excellent power capability (182.5 mA h g-1 at 2 A g-1), and a long cycle lifespan of 500 cycles with a capacity retention of 66.5% at a current density of 1 A g-1. The fabricated rechargeable solid-state Li/M-LVO-Y-2 lithium metal battery (LMB) with a poly(ethylene oxide) (PEO)-based solid polymer electrolyte (SPE) achieves a high discharge capacity of 302.1 mA h g-1 at 0.05 A g-1 and a stable cycling performance with the highest capacity of 72.1% after 100 cycles at 0.2 A g-1 and 80 °C. The above battery performance demonstrates that SSLMBs with the CNTs/LiV3O8/Y2O3 cathode and the PEO-based SPE film can provide high energy density and are suitable for applying in a high-temperature environment.

16.
Membranes (Basel) ; 10(10)2020 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-33050535

RESUMEN

Sulfonated aromatic polymer (SAP) featuring hydrophilic nanochannels for water transport is a promising membrane material for desalination. SAPs with a high sulfonation degree favor water transport but suffer from reduced mechanical strength and membrane swelling. In this work, a hyperbranched polyester, H302, was introduced to crosslink a sulfonated styrene-ethylene/butylene-styrene (S-SEBS) copolymer membrane. The effects of crosslinking temperature and amount of H302 on the microstructure, and the pervaporation desalination performance of the membrane, were investigated. H302/S-SEBS copolymer membranes with different crosslinking conditions were characterized by various techniques including FTIR, DSC, EA, SEM, TEM and SAXS, and tensile strength, water sorption and contact angle measurements. The results indicate that the introduction of hyperbranched polyester enlarged the hydrophilic microdomain of the S-SEBS membrane. Crosslinking with hyperbranched polyester with heat treatment effectively enhanced the mechanical strength of the S-SEBS membrane, with the tensile strength being increased by 140-200% and the swelling ratio reduced by 45-70%, while reasonable water flux was maintained. When treating 5 wt% hypersaline water at 65 °C, the optimized crosslinked membrane containing 15 wt% H302 and heated at 100 °C reached a water flux of 9.3 kg·m-2·h-1 and a salt rejection of 99.9%. The results indicate that the hyperbranched-S-SEBS membrane is promising for use in PV desalination.

17.
ACS Cent Sci ; 6(8): 1431-1440, 2020 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-32875084

RESUMEN

Single-atom catalysts (SACs) have attracted widespread interest for many catalytic applications because of their distinguishing properties. However, general and scalable synthesis of efficient SACs remains significantly challenging, which limits their applications. Here we report an efficient and universal approach to fabricating a series of high-content metal atoms anchored into hollow nitrogen-doped graphene frameworks (M-N-Grs; M represents Fe, Co, Ni, Cu, etc.) at gram-scale. The highly compatible doped ZnO templates, acting as the dispersants of targeted metal heteroatoms, can react with the incoming gaseous organic ligands to form doped metal-organic framework thin shells, whose composition determines the heteroatom species and contents in M-N-Grs. We achieved over 1.2 atom % (5.85 wt %) metal loading content, superior oxygen reduction activity over commercial Pt/C catalyst, and a very high diffusion-limiting current (6.82 mA cm-2). Both experimental analyses and theoretical calculations reveal the oxygen reduction activity sequence of M-N-Grs. Additionally, the superior performance in Fe-N-Gr is mainly attributed to its unique electron structure, rich exposed active sites, and robust hollow framework. This synthesis strategy will stimulate the rapid development of SACs for diverse energy-related fields.

18.
Nanoscale ; 12(16): 9246-9254, 2020 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-32307502

RESUMEN

1T-MoS2 is widely used in the hydrogen evolution reaction (HER) due to its abundant active sites and good conductivity. However, 1T-MoS2 is thermodynamically metastable due to the distorted crystal structure. Recently, researchers have detected the J1 and A1g Raman peaks after the HER process and confirmed that the 2H-1T phase possesses good stability. Therefore, continuous HER is likely to transform 1T-MoS2 into a stable 2H-1T mixed phase. The in situ characterization of 1T-MoS2 individual nanosheets in the HER process is important to understand the intrinsic electrocatalytic behaviour at confined nanoscale, which has rarely been investigated. Herein, we built an individual 1T-MoS2 nanosheet micro-nano device by the intercalation of N-butyllithium into 2H-MoS2. Then, the device was kept at an overpotential (η) of 450 mV, which was much lower than the onset potential, for 20 minutes to ensure continuous HER. Through this electrochemical treatment, we successfully obtained a mixed phase of 2H-1T and monitored the electrochemical phase transition by in situ Raman mapping and atomic force microscopy (AFM). The HER performance of the 2H-1T phase was superior to that of 1T-MoS2 and 2H-MoS2. Additionally, computational simulations demonstrated that the 2H-1T phase exhibited optimal hydrogen adsorption energy. The presented work displays the excellent catalysis of the mixed phase obtained by the electrochemical phase transition, which provides new directions for improving the catalytic activity of TMDs.

19.
ACS Appl Mater Interfaces ; 12(9): 10420-10427, 2020 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-32028764

RESUMEN

A rechargeable aqueous zinc-ion battery (ZIB) is one of the attractive candidates for large-scale energy storage. Its further application relies on the exploitation of a high-capacity cathode and the understanding of an intrinsic energy storage mechanism. Herein, we report a novel layered K2V3O8 cathode material for the ZIB, adopting a strategy of charging first to extract part of K-ions from vanadate in initial few cycles, which creates more electrochemically active sites and lowers charge-transfer resistance of the ZIB system. As a result, a considerable specific capacity of 302.8 mA h g-1 at 0.1 A g-1, as well as a remarkable cycling stability (92.3% capacity retention at 4 A g-1 for 2000 cycles) and good rate capability, are achieved. Besides, the energy storage mechanism was studied by in situ X-ray diffraction, in situ Raman spectroscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma mass spectroscopy. An irreversible K-ion deintercalation in the first charge process is proved. It is believed that this novel cathode material for the rechargeable aqueous ZIB and the optimizing strategy will shed light on developing next-generation large-scale energy storage devices.

20.
Plant J ; 102(5): 931-947, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-31908046

RESUMEN

Phytohormone brassinosteroids (BRs) are essential for plant growth and development, but the mechanisms of BR-mediated pollen development remain largely unknown. In this study, we show that pollen viability, pollen germination and seed number decreased in the BR-deficient mutant d^im , which has a lesion in the BR biosynthetic gene DWARF (DWF), and in the bzr1 mutant, which is deficient in BR signaling regulator BRASSINAZOLE RESISTANT 1 (BZR1), compared with those in wild-type plants, whereas plants overexpressing DWF or BZR1 exhibited the opposite effects. Loss or gain of function in the DWF or BZR1 genes altered the timing of reactive oxygen species (ROS) production and programmed cell death (PCD) in tapetal cells, resulting in delayed or premature tapetal degeneration, respectively. Further analysis revealed that BZR1 could directly bind to the promoter of RESPIRATORY BURST OXIDASE HOMOLOG 1 (RBOH1), and that RBOH1-mediated ROS promote pollen and seed development by triggering PCD and tapetal cell degradation. In contrast, the suppression of RBOH1 compromised BR signaling-mediated ROS production and pollen development. These findings provide strong evidence that BZR1-dependent ROS production plays a critical role in the BR-mediated regulation of tapetal cell degeneration and pollen development in Solanum lycopersicum (tomato) plants.


Asunto(s)
Polen/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Solanum lycopersicum/metabolismo , Apoptosis/genética , Apoptosis/fisiología , Brasinoesteroides/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/fisiología , Solanum lycopersicum/fisiología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polen/fisiología , Transducción de Señal/genética , Transducción de Señal/fisiología
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