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Understanding nanodiamond structures is of great scientific and practical interest. It has been a long-standing challenge to unravel the complexity underlying nanodiamond structures and to resolve the controversies surrounding their polymorphic forms. Here, we use transmission electron microscopy with high-resolution imaging, electron diffraction, multislice simulations, and other supplementary techniques to study the impacts of small sizes and defects on cubic diamond nanostructures. The experimental results show that common cubic diamond nanoparticles display the (200) forbidden reflections in their electron diffraction patterns, which makes them indistinguishable from new diamond (n-diamond). The multislice simulations demonstrate that cubic nanodiamonds smaller than 5 nm can present the d-spacing at 1.78 Å corresponding to the (200) forbidden reflections, and the relative intensity of these reflections increases as the particle size decreases. Our simulation results also reveal that defects, such as surface distortions, internal dislocations, and grain boundaries can also make the (200) forbidden reflections visible. These findings provide valuable insights into the diamond structural complexity at nanoscale, the impact of defects on nanodiamond structures, and the discovery of novel diamond structures.
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Individuals differ in their sensitivity to the adverse consequences of their actions, leading some to persist in maladaptive behaviors. Two pathways have been identified for this insensitivity: a motivational pathway based on excessive reward valuation and a behavioral pathway based on autonomous stimulus-response mechanisms. Here, we identify a third, cognitive pathway based on differences in punishment knowledge and use of that knowledge to suppress behavior. We show that distinct phenotypes of punishment sensitivity emerge from differences in what people learn about their actions. Exposed to identical punishment contingencies, some people (sensitive phenotype) form correct causal beliefs that they use to guide their behavior, successfully obtaining rewards and avoiding punishment, whereas others form incorrect but internally coherent causal beliefs that lead them to earn punishment they do not like. Incorrect causal beliefs were not inherently problematic because we show that many individuals benefit from information about why they are being punished, revaluing their actions and changing their behavior to avoid further punishment (unaware phenotype). However, one condition where incorrect causal beliefs were problematic was when punishment is infrequent. Under this condition, more individuals show punishment insensitivity and detrimental patterns of behavior that resist experience and information-driven updating, even when punishment is severe (compulsive phenotype). For these individuals, rare punishment acted as a "trap," inoculating maladaptive behavioral preferences against cognitive and behavioral updating.
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Castigo , Recompensa , Castigo/psicología , Aprendizaje , Motivación , CogniciónRESUMEN
BACKGROUND: Diosgenin is an important steroidal precursor renowned for its diverse medicinal uses. It is predominantly sourced from Dioscorea species, particularly Dioscorea zingiberensis. Dioscorea zingiberensis has an ability to accumulate 2-16% diosgenin in its rhizomes. In this study, a diverse population of 180 D. zingiberensis accessions was used to evaluate the genomic regions associated with diosgenin biosynthesis by the genome wide association study approach (GWAS). RESULTS: The whole population was characterized for diosgenin contents from tubers by gas chromatography mass spectrometry. The individuals were genotyped by the genotyping-by-sequencing approach and 10,000 high-quality SNP markers were extracted for the GWAS. The highest significant marker-trait-association was observed as an SNP transversion (G to T) on chromosome 10, with 64% phenotypic variance explained. The SNP was located in the promoter region of CYP94D144 which is a member of P450 gene family involved in the independent biosynthesis of diosgenin from cholesterol. The transcription factor (TF) binding site enrichment analysis of the promoter region of CYP94D144 revealed NAC TF as a potential regulator. The results were further validated through expression profiling by qRT-PCR, and the comparison of high and low diosgenin producing hybrids obtained from a bi-parental population. CONCLUSIONS: This study not only enhanced the understanding of the genetic basis of diosgenin biosynthesis but also serves as a valuable reference for future genomic investigations on CYP94D144, with the aim of augmenting diosgenin production in yam tubers.
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Dioscorea , Diosgenina , Estudio de Asociación del Genoma Completo , Tubérculos de la Planta , Polimorfismo de Nucleótido Simple , Diosgenina/metabolismo , Dioscorea/genética , Dioscorea/metabolismo , Tubérculos de la Planta/genética , Tubérculos de la Planta/metabolismo , Variación GenéticaRESUMEN
With the increasing volume of human sequencing data available, analysis incorporating external controls becomes a popular and cost-effective approach to boost statistical power in disease association studies. To prevent spurious association due to population stratification, it is important to match the ancestry backgrounds of cases and controls. However, rare variant association tests based on a standard logistic regression model are conservative when all ancestry-matched strata have the same case-control ratio and might become anti-conservative when case-control ratio varies across strata. Under the conditional logistic regression (CLR) model, we propose a weighted burden test (CLR-Burden), a variance component test (CLR-SKAT) and a hybrid test (CLR-MiST). We show that the CLR model coupled with ancestry matching is a general approach to control for population stratification, regardless of the spatial distribution of disease risks. Through extensive simulation studies, we demonstrate that the CLR-based tests robustly control type 1 errors under different matching schemes and are more powerful than the standard Burden, SKAT and MiST tests. Furthermore, because CLR-based tests allow for different case-control ratios across strata, a full-matching scheme can be employed to efficiently utilize all available cases and controls to accelerate the discovery of disease associated genes.
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Modelos Genéticos , Estudios de Casos y Controles , Simulación por Computador , Humanos , Modelos LogísticosRESUMEN
Herein, a fiber-supported iron-based ionic liquid as a type of fibrous catalyst has been developed for the synthesis of bioactive 3,4-dihydropyrimidin-2-(1H)-ones (DHPMs) via three-component Biginelli reactions in a cleaner manner. The described fibrous catalyst was obtained from the commercially available polyetheretherketone (PEEK) fiber by postfunctionalization processes and was characterized and analyzed in detail by means of diversified technologies. Furthermore, the fiber-supported iron-based ionic liquids could mediate the classical three-component Biginelli reactions to proceed smoothly to gain a variety of substituted DHPMs with yields of up to 99%. The superior catalytic activities of the fibrous catalyst were ascribed to the quasi-homogeneous medium by ionic liquids generated in the surface layer of the PEEK fiber, which could afford an appropriate reaction zone and could further be available for the aggregation of substrates to facilitate the three-component reaction. Notably, the fibrous catalyst is available for recycling over 10 runs just by a pair of tweezers, and the operational procedure was capable of enlarging the catalytic system to the gram-scale without any performance degradation, which provided a cleaner manner to take advantage of the iron-based catalyst in organic synthesis with potential industrialization prospects.
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Highly selective synthesis of primary amines from renewable biomass has attracted increasing attention, but it still faces great challenges in chemical industry applications. In this study, an electron-rich Ru catalyst was constructed by doping N into coffee biochar using a one-pot carbonization method (Ru/NCB-600). Ru/NCB-600 showed high catalytic activity and yield for the reductive amination of furfural with green and cheap NH3 and H2. The excellent catalytic performance of Ru/NCB-600 was closely correlated to the formation of electron-rich Ruδ- species (Ruδ--Nxδ+), which endowed Ru/NCB-600 with an enhanced H2 adsorption and activation ability. Ru/NCB-600 showed a high formation rate of 95.6 gfurfurylamine·gRu-1·h-1 and a high yield of furfurylamine (98.6%) at 50 °C. Ru/NCB-600 can also be used for the reductive amination of various carbonyl compounds in good to excellent yield (95.4-99%). This study thus provides a potential pathway for the highly selective reductive amination of carbonyl compounds by regulating the electron density of Ru.
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The γ-cyclodextrin (γ-CD) metal-organic frameworks (CD-MOF-1) consist of γ-CD and potassium (K+) ions through coordinating an eight-coordinated K+ ion with two C5-linked oxygen and C6-linked hydroxyl (C5-O/C6-OH) groups in the primary faces of adjacent γ-CD units and two C2- and C3-linked hydroxyl (C2-OH/C3-OH) groups in the secondary faces. Herein, we found polysaccharide gels with only C2-OH/C3-OH or C5-O/C6-OH groups in pyranoid rings can form four-coordinated K+ ions and then coordinate γ-CD in a KOH solution for CD-MOF-1 growth. Exposure of C2-OH/C3-OH or C5-O/C6-OH groups in polysaccharide gels is important to form active four-coordinated K+ ions. Mechanism supporting this work is that four-coordinated K+ ion sites are first formed after coordinating C2-OH/C3-OH groups in pectin and then coordinating C5-O/C6-OH groups in the primary faces of γ-CD units. Alternatively, four-coordinated K+ ions with C5-O/C6-OH groups in chitosan can coordinate the C2-OH/C3-OH groups in the secondary faces of γ-CD units. Mechanism of CD-MOF-1 growing on pectin and chitosan gels through the proposed four-coordinated K+ ions is also universally applicable to other polysaccharide gels with similar C2-OH/C3-OH or C5-O/C6-OH groups such as alginate gel. Based on this mechanism, we developed pectin and chitosan gel-based CD-MOF-1 composites and exemplified applications of them in antibacterial and organic dye removal. To help future research and applications of this mechanism, we share our theoretical assumption for further investigations that any matrices with an ortho-hydroxyl carbon chain or ortho-hydroxyl ether structures may form four-coordinated K+ ions for CD-MOF-1 growth. The proposed mechanism will broaden the development of novel CD-MOF-1 composites in various fields.
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Geles , Potasio , Potasio/química , Geles/química , Porosidad , gamma-Ciclodextrinas/química , Estructuras Metalorgánicas/química , Polisacáridos/química , Pectinas/química , Iones/químicaRESUMEN
Resolvin (Rv) and lipoxin (Lx) play important regulative roles in the development of several inflammation-related diseases. The dysregulation of their metabolic network is believed to be closely related to the occurrence and development of asthma. The Hyssopus Cuspidatus Boriss extract (SXCF) has long been used as a treatment for asthma, while the mechanism of anti-inflammatory and anti-asthma action targeting Rv and Lx has not been thoroughly investigated. In this study, we aimed to investigate the effects of SXCF on Rv, Lx in ovalbumin (OVA)-sensitized asthmatic mice. The changes of Rv, Lx before and after drug administration were analyzed based on high sensitivity chromatography-multiple response monitoring (UHPLC-MRM) analysis and multivariate statistics. The pathology exploration included behavioral changes of mice, IgE in serum, cytokines in BALF, and lung tissue sections stained with H&E. It was found that SXCF significantly modulated the metabolic disturbance of Rv, Lx due to asthma. Its modulation effect was significantly better than that of dexamethasone and rosmarinic acid which is the first-line clinical medicine and the main component of Hyssopus Cuspidatus Boriss, respectively. SXCF is demonstrated to be a potential anti-asthmatic drug with significant disease-modifying effects on OVA-induced asthma. The modulation of Rv and Lx is a possible underlying mechanism of the SXCF effects.
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Antiasmáticos , Asma , Lipoxinas , Ratones , Animales , Lipoxinas/farmacología , Asma/inducido químicamente , Asma/tratamiento farmacológico , Asma/metabolismo , Antiasmáticos/efectos adversos , Pulmón/metabolismo , Citocinas/metabolismo , Extractos Vegetales/farmacología , Ratones Endogámicos BALB C , Modelos Animales de EnfermedadRESUMEN
Recently, organic-inorganic hybrid perovskites exhibiting facile structural phase transitions have accumulated significant attention due to their switchable second-order nonlinear optical (NLO) properties, which hold significant promise for next-generation intelligent optoelectronic devices. In this study, we present a novel one-dimensional hexagonal hybrid perovskite, (4-methoxypiperidinium)CdCl3, which undergoes a reversible high-temperature structural phase transition at 389 K. Notably, (4-methoxypiperidinium)CdCl3 demonstrates switchable second-order NLO and dielectric properties, accompanied by symmetry breaking from the centrosymmetric Pnma to noncentrosymmetric Pna21 space group. Variable-temperature structure analyses reveal that this transition is mainly driven by the order-disorder transformation of the 4-methoxypiperidinium cations. Furthermore, it also features a promising photoluminescence performance with blue-light emission and a long lifetime of 25.34 ns. It is anticipated that this study will expand the family of hybrid perovskites exhibiting high-temperature phase transitions and offer valuable guidance for the design of new NLO switching materials with superior optoelectronic properties.
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Gallium oxide (Ga2O3) is a promising wide bandgap semiconductor that is viewed as a contender for the next generation of high-power electronics due to its high theoretical breakdown electric field and large Baliga's figure of merit. Here, we report a facile route of synthesizingß-Ga2O3via direct oxidation conversion using solution-processed two-dimensional (2D) GaS semiconducting nanomaterial. Higher order of crystallinity in x-ray diffraction patterns and full surface coverage formation in scanning electron microscopy images after annealing were achieved. A direct and wide bandgap of 5 eV was calculated, and the synthesizedß-Ga2O3was fabricated as thin film transistors (TFT). Theß-Ga2O3TFT fabricated exhibits remarkable electron mobility (1.28 cm2Vs-1) and a good current ratio (Ion/Ioff) of 2.06 × 105. To further boost the electrical performance and solve the structural imperfections resulting from the exfoliation process of the 2D nanoflakes, we also introduced and doped graphene inß-Ga2O3TFT devices, increasing the electrical device mobility by â¼8-fold and thereby promoting percolation pathways for the charge transport. We found that electron mobility and conductivity increase directly with the graphene doping concentration. From these results, it can be proved that theß-Ga2O3networks have excellent carrier transport properties. The facile and convenient synthesis method successfully developed in this paper makes an outstanding contribution to applying 2D oxide materials in different and emerging optoelectronic applications.
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Fetal growth restriction (FGR) severely affects the health outcome of newborns and represents a major cause of perinatal morbidity. The precise involvement of circCULT1 in the progression of FGR remains unclear. We performed next-generation sequencing and RT-qPCR to identify differentially expressed circRNAs in placental tissues affected by FGR by comparing them with unaffected counterparts. Edu, flow cytometry, and transwell assay were conducted to detect HTR8/SVneo cell's function in regard to cell proliferation, migration, and invasion. The interaction between circCUL1 and hsa-miR-30e-3p was assessed through dual-luciferase reporter assays, validation of the interaction between circCUL1 and ANXA1 was performed using RNA pulldown and immunoprecipitation assays. Western blot analysis was performed to evaluate protein levels of autophagy markers and components of the PI3K/AKT signaling pathway. A knockout (KO) mouse model was established for homologous mmu-circ-0001469 to assess fetal mouse growth and development indicators. Our findings revealed an upregulation of circCUL1 expression in placental tissues from patients with FGR. We found that suppression of circCUL1 increased the trophoblast cell proliferation, migration, and invasion, circCUL1 could interact with hsa-miR-30e-3p. Further, circCUL1 stimulated autophagy, modulating trophoblast cell autophagy via the ANXA1/PI3K/AKT pathway, and a notable disparity was observed, with KO mice displaying accelerated embryo development and exhibiting heavier placentas in comparison to wild-type C57BL/6 mice. By modulating the ANXA1/PI3K/AKT signaling pathway through the interaction with hsa-miR-30e-3p, circCUL1 promotes autophagy while concurrently suppressing trophoblast cell proliferation, migration, and invasion. These findings offer novel insights into potential diagnostic markers and therapeutic targets for FGR research.
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Autofagia , Movimiento Celular , Retardo del Crecimiento Fetal , MicroARNs , Fosfatidilinositol 3-Quinasas , Proteínas Proto-Oncogénicas c-akt , Trofoblastos , Animales , Femenino , Humanos , Ratones , Embarazo , Anexina A1 , Retardo del Crecimiento Fetal/metabolismo , Retardo del Crecimiento Fetal/genética , Retardo del Crecimiento Fetal/patología , Ratones Noqueados , MicroARNs/metabolismo , MicroARNs/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Circular/genética , ARN Circular/metabolismo , Transducción de Señal , Trofoblastos/metabolismo , Trofoblastos/patologíaRESUMEN
Investigations of information-seeking often highlight people's tendency to forgo financial reward in return for advance information about future outcomes. Most of these experiments use tasks in which reward contingencies are described to participants. The use of such descriptions leaves open the question of whether the opportunity to obtain such noninstrumental information influences people's ability to learn and represent the underlying reward structure of an experimental environment. In two experiments, participants completed a two-armed bandit task with monetary incentives where reward contingencies were learned via trial-by-trial experience. We find, akin to description-based tasks, that participants are willing to forgo financial reward to receive information about a delayed, unchangeable outcome. Crucially, however, there is little evidence this willingness to pay for information is driven by an inaccurate representation of the reward structure: participants' representations approximated the underlying reward structure regardless of the presence of advance noninstrumental information. The results extend previous conclusions regarding the intrinsic value of information to an experience-based domain and highlight challenges of probing participants' memories for experienced rewards.
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Recompensa , Humanos , Adulto , Adulto Joven , Masculino , Femenino , Aprendizaje/fisiología , Conducta en la Búsqueda de Información/fisiologíaRESUMEN
Pomegranate (Punica granatum) is an important fruit crop for therapeutic and food applications. In June 2022, brown spots were observed on the fruit surface of pomegranate cultivar named Guangyan in Mengzi (23°20'6''N,103°25'5''E), Yunnan, China. The early spots appeared as circular or irregular lesions, measuring 1~1.5 mm in diameter. They were light brown with a clear boundary between disease and healthy tissues. Over time, these spots developed into polygonal lesions covering the entire fruit surface. Eventually, the diseased fruits decayed, and more than 50% of fruits were infected in pomegranate orchards. The tissues from the interface between health and disease were cut down, immersed in 75% ethanol for 15 s, then 5% NaOCl disinfecting for 2 min, washed three times with sterile water, and the PDA cultured at 26 °C in an incubator under dark conditions. Twenty-five samples were collected for pathogen isolation, ten fungal isolates were obtained by single spore germination, and these isolates had similar morphological characters. The colonies were white with 81 mm diameter at 7 days of incubation, containing undulate edges with dense aerial mycelium. After 14 days, the black conidiomata formed superficially, gathering into black droplets. Conidiogenous cells were hyaline, short, and filiform. Conidia were fusiform, straight or slightly curved, and comprised five cells, 24.12 to 34.53 (xÌ=29.78) µm × 4.21 to 12.15 (xÌ=8.68) µm (n=50). The three median cells were 13.13 to 25.22 µm (xÌ=18.54), dark brown, whose septa and periclinal walls were darker than the other two cells. The apical cells showed two to four appendages, 12.31 to 29.15 (xÌ=21.56) µm. Only a single appendage was found on the basal cell, 2.34 to 7.16 µm. Based on morphological features, these isolates were identified as Neopestalotiopsis clavispora (Maharachchikumbura et al., 2012, 2014). Molecular identification of isolate YNSL-3 was performed by amplification and sequencing of ITS4/ITS5, BT2A/ BT2B and EF1-728F/EF-2, respectively (White et al. 1990, Glass et al.1995, Carbone et al. 1999, O'Donnell et al. 1998). These base sequences were deposited in GenBank with accession numbers OQ891378 (ITS), OR088917 (Tef) and OR513439(Tub), respectively. BLAST searches of the sequences revealed 100% (478/478 bp), 100% (484/484 bp), and 94.67% (426/450 bp) homology with those of N. clavispora NM16311a from GenBank (LC209216, LC209220, and LC209221), respectively. Phylogenetic analysis (IQ-TREE) by maximum likelihood method showed that the isolate YNSL-3 was clustered with N. clavispora. The pathogenicity was tested with the isolate of YNSL-3, YNSL-5 and YNSL-8 by detached assay. The fruit surface of pomegranate cultivar Guangyan was wounded with a sterilized needle. The mycelial blocks (5mm2) of isolates cultured on PDA for 7 days were attached to the points of inoculation. Controls were inoculated with sterile PDA agar. All inoculated fruits were maintained in a growth chamber at 26°C with 75% relative humidity. The test was performed thrice. The brown lesions were observed after 7 days, whereas the controls showed no symptoms. The same pathogens reisolated were identical to the original isolates based on morphological characterization and molecular analyses. N. clavispora could cause different diseases in many plants (Rajashekara et al. 2023, Loredana et al. 2020). To our knowledge, this is the first report of fruit brown spot on Punica granatum caused by N. clavispora in China. This finding will help improve management strategies against the fruit brown spots on P. granatum in China.
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Auxin plays an essential role in modulating leaf development. However, its role in leaf development in rice (Oryza sativa L.) remains largely unknown. In this study, we found that PINOID (OsPID) and two Sister-of-PIN1s, termed PIN-FORMED1c (OsPIN1c) and OsPIN1d, are necessary for rice leaf development. The ospin1c ospin1d null mutant lines presented severe defects in leaf morphogenesis, including drooping and semi-drooping blades, an abnormally thickened sheath and lamina joint, and fused leaves with absent ligules and auricles. Loss-of-function ospid mutants displayed generally similar leaf morphology but lacked leaf fusion. Interestingly, misshaped leaf genesis displayed a preference for being ipsilateral. In addition, OsPIN1c and OsPID were commonly localized in the initiating leaf primordia. Furthermore, accompanied by the more severe organ morphogenesis in the ospin1c ospin1d ospid triple mutant, RNA sequencing analysis revealed that many genes essential for leaf development have an altered expression level. Together, this study furthers our understanding of the role auxin transport plays during leaf development in monocot rice.
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Oryza , Proteínas de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Oryza/metabolismo , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Ácidos Indolacéticos/metabolismo , Morfogénesis/genéticaRESUMEN
Rumination is closely linked to the onset and maintenance of major depressive disorder (MDD). Prior neuroimaging studies have identified the association between self-reported rumination trait and the functional coupling among a network of brain regions using resting-state functional magnetic resonance imaging (MRI). However, little is known about the underlying neural circuitry mechanism during active rumination in MDD. Degree centrality (DC) is a simple metric to denote network integration, which is critical for higher-order psychological processes such as rumination. During an MRI scan, individuals with MDD (N = 45) and healthy controls (HC, N = 46) completed a rumination state task. We examined the interaction effect between the group (MDD vs. HC) and condition (rumination vs. distraction) on vertex-wise DC. We further characterized the identified brain region's functional involvement with Neurosynth and BrainMap. Network-wise seed-based functional connectivity (FC) analysis was also conducted for the identified region of interest. Finally, exploratory correlation analysis was conducted between the identified region of interest's network FCs and self-reported in-scanner affect levels. We found that a left superior frontal gyrus (SFG) region, generally overlapped with the frontal eye field, showed a significant interaction effect. Further analysis revealed its involvement with executive functions. FCs between this region, the frontoparietal, and the dorsal attention network (DAN) also showed significant interaction effects. Furthermore, its FC to DAN during distraction showed a marginally significant negative association with in-scanner affect level at the baseline. Our results implicated an essential role of the left SFG in the rumination's underlying neural circuitry mechanism in MDD and provided novel evidence for the conceptualization of rumination in terms of impaired executive control.
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Trastorno Depresivo Mayor , Humanos , Encéfalo/diagnóstico por imagen , Corteza Prefrontal , Función Ejecutiva , Lóbulo Frontal , Imagen por Resonancia Magnética , Mapeo EncefálicoRESUMEN
Covalent organic frameworks (COFs) have emerged as a new class of cathode materials for energy storage in recent years. However, they are limited to two-dimensional (2D) or three-dimensional (3D) framework structures. Herein, this work reports designed synthesis of a redox-active one-dimensional (1D) COF and its composites with 1D carbon nanotubes (CNTs) via in situ growth. Used as cathode materials for Li-ion batteries, the 1D COF@CNT composites with unique dendritic core-shell structure can provide abundant and easily accessible redox-active sites, which contribute to improve diffusion rate of lithium ions and the corresponding specific capacity. This synergistic structural design enables excellent electrochemical performance of the cathodes, giving rise to 95% utilization of redox-active sites, high rate capability (81% capacity retention at 10 C), and long cycling stability (86% retention after 600 cycles at 5 C). As the first example to explore the application of 1D COFs in the field of energy storage, this study demonstrates the great potential of this novel type of linear crystalline porous polymers in battery technologies.
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Boron-based covalent organic frameworks (COFs) are susceptible to nucleophilic attack by water at the electron-deficient boron sites and even slightly humid air could destroy the integrity of their porous frameworks within hours. Such instability is a major limitation to the practical applications of boron-based COFs. Herein we report a significant enhancement of hydrostability of boroxine-linked COFs (COF-1 as representative) by modification with an oligoamine (tetraethylenepentamine, TEPA), which leads to survival of the modified COF in water and long-time stability under humid atmosphere. Meanwhile, the TEPA modification also results in a considerable increase in CO2 adsorption capacity up to 13â times and a dramatic improvement in CO2 /N2 selectivity in low pressure region, which make the modified COF suitable for capturing CO2 from flue gas. This work provides a facile, efficient, and scalable method to greatly improve hydrostability of boroxine-linked COFs and reshape them into high-performance CO2 adsorbents.
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Increasing environmental problems intensify the demand for high-performance environmental purification materials. MXene is a typical transition-metal carbide/nitride material with a two-dimensional geometric feature and a good deal of functional groups, and it is considered as an efficient adsorbent for removing pollutants from wastewater. However, the easy oxidation and relatively low adsorption capacity greatly restrict its application. In this study, the MXene/polydopamine (PDA) composite particles were fabricated through the biomimetic modification method of inducing the self-polymerization of dopamine in an MXene aqueous solution. Microstructure characterizations demonstrate that PDA facilitates the exfoliation of MXene. Adsorption measurements show that MXene and PDA exhibit an apparent synergistic effect in removing chromium hexavalent Cr(VI) from aqueous solution, and more PDA content leads to a larger synergistic effect. Consequently, the composite particles exhibit an ultrahigh adsorption capacity (862.3 mg/g). Specifically, even if the composite particles were stored in aqueous solution for 2 months, they still exhibit high adsorption ability with only a 3.3% loss in adsorption capacity, indirectly confirming the enhanced stability of MXene induced by PDA. Furthermore, the composite particles also show reduction ability to Cr(VI) and about 54.3% Cr(VI) can be reduced to harmless chromium trivalent Cr(III). This study provides a new method for the preparation of MXene-based adsorbents with excellent adsorption capacity and high stability, which has broad application prospects in the field of wastewater treatment.
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Selective reduction of nitroaromatics to the corresponding aromatic amines is extremely an attractive chemical process for both fundamental research and potential commercial applications. Herewith, we report that a highly dispersed Cu catalyst supported on H3PO4-activated coffee biochar and the resulting Cu/PBCR-600 catalyst show complete conversion of the nitroaromatics and >97.0% selectivity for the corresponding aromatic amines. The TOF of catalyzing the reduction of nitroaromatics (1.55-460.74 min-1) is approximately 2 to 15 times higher than those of previously reported non-noble and even noble metal catalysts. Additionally, Cu/PBCR-600 also shows high stability in catalytic recycles. Furthermore, it exhibits long-term catalytic stability (660 min) for practical application in a continuous-flow reactor. The characterizations and activity tests reveal that Cu0 existing in Cu/PBCR-600 acts as an active site in nitroaromatics reduction. Also, the further characterization by FTIR and UV-vis demonstrates that N, P co-doped coffee biochar could selectively adsorb and activate the nitro group of nitroaromatics.
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Phosphodiesterase 5 (PDE5) is a cyclic guanosine monophosphate-degrading enzyme involved in numerous biological pathways. Inhibitors of PDE5 are important therapeutics for the treatment of neurodegenerative diseases, including Alzheimer's disease (AD). We previously reported the first generation of quinoline-based PDE5 inhibitors for the treatment of AD. However, the short in vitro microsomal stability rendered them unsuitable drug candidates. Here we report a series of new quinoline-based PDE5 inhibitors. Among them, compound 4b, 8-cyclopropyl-3-(hydroxymethyl)-4-(((6-methoxypyridin-3-yl)methyl)amino)quinoline-6-carbonitrile, shows a PDE5 IC50 of 20 nM and improved in vitro microsomal stability (t1/2 = 44.6 min) as well as excellent efficacy in restoring long-term potentiation, a type of synaptic plasticity to underlie memory formation, in electrophysiology experiments with a mouse model of AD. These results provide an insight into the development of a new class of PDE5 inhibitors for the treatment of AD.