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1.
J Aging Res ; 2024: 4946303, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38746043

RESUMO

Background: Subjective cognitive decline (SCD) in older individuals has been implicated as a possible precursor to Alzheimer's disease. Poor sleep quality and anxiety/depressive symptoms have been linked to the progression of SCD, but these associations and older adults' worries have yet to be fully established in the Chinese older adult population, which is one of the largest in the world. The aim of this study was to explore the relationship between sleep quality, anxiety/depression symptoms, and worries, and SCD prevalence among Chinese community-dwelling older individuals. Methods: A total of 707 adults aged between 60 and 99 from Shanghai, China, completed self-report questionnaires that covered their cognitive and mental well-being, as well as demographic information. Subjective cognitive decline (SCD) was evaluated using the memory/cognition syndromes of the old adult self-report (OASR). Sleep quality, anxiety/depression, and worries were measured from their respective sections of the OASR. Results: The general linear regression models showed that poorer sleep quality was associated with an increased prevalence of anxiety/depression symptoms, worries, and SCD among older adults. As suggested by the mediation analysis, anxiety/depression and worries were significant mediators in the relationship between sleep quality and SCD prevalence, and these two factors also have a serial mediation effect between sleep quality and SCD prevalence. Conclusions: Poorer sleep quality is associated with a higher rate of SCD among older adults, and a higher prevalence of anxiety/depression and worries mediate this relationship, suggesting possible mechanism pathways that lead to SCD. These factors may provide the basis for early, targeted interventions for older adults' mental health preservation and improved quality of life.

2.
Angew Chem Int Ed Engl ; 63(8): e202315599, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38169100

RESUMO

Polypeptides, as natural polyelectrolytes, are assembled into tailored proteins to integrate chromophores and catalytic sites for photosynthesis. Mimicking nature to create the water-soluble nanoassemblies from synthetic polyelectrolytes and photocatalytic molecular species for artificial photosynthesis is still rare. Here, we report the enhancement of the full-spectrum solar-light-driven H2 production within a supramolecular system built by the co-assembly of anionic metalloporphyrins with cationic polyelectrolytes in water. This supramolecular photocatalytic system achieves a H2 production rate of 793 and 685 µmol h-1 g-1 over 24 h with a combination of Mg or Zn porphyrin as photosensitizers and Cu porphyrin as a catalyst, which is more than 23 times higher than that of free molecular controls. With a photosensitizer to catalyst ratio of 10000 : 1, the highest H2 production rate of >51,700 µmol h-1 g-1 with a turnover number (TON) of >1,290 per molecular catalyst was achieved over 24 h irradiation. The hierarchical self-assembly not only enhances photostability through forming ordered stackings of the metalloporphyrins but also facilitates both energy and electron transfer from antenna molecules to catalysts, and therefore promotes the photocatalysis. This study provides structural and mechanistic insights into the self-assembly enhanced photostability and catalytic performance of supramolecular photocatalytic systems.

3.
iScience ; 26(9): 107658, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37664633

RESUMO

Humans can distinguish flying birds from drones based solely on motion features when no image information is available. However, it remains unclear which motion features of animate motion induce our animacy perception. To address this, we first analyzed the differences in centroid motion between birds and drones, and discovered that birds exhibit greater acceleration, angular speed, and trajectory fluctuations. We further determined the order of their importance in evoking animacy perception was trajectory fluctuations, acceleration, and speed. More interestingly, people judge whether a moving object is alive using a feature-matching strategy, implying that animacy perception is induced in a key feature-triggered way rather than relying on the accumulation of evidence. Our findings not only shed light on the critical motion features that induce animacy perception and their relative contributions but also have important implications for developing target classification algorithms based on motion features.

4.
Angew Chem Int Ed Engl ; 62(21): e202302274, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36942477

RESUMO

Two-dimensional (2D) organic polymers have recently received considerable interest, especially those whose architectures are held together via supramolecular engineering. However, current approaches toward supramolecular 2D structures usually suffer from mutual interference of noncovalent interactions and lack of intrinsic functions. Herein, we report well-regulated 2D supramolecular polymers (2DSPs) through an aromatics-selective recognition strategy of cation-π and donor-acceptor (D-A) motifs, which are derived from C4 -symmetric cationic monomers and electron-withdrawing molecules. By subtly designing the strength and direction of noncovalent driving forces, the mutual interference between cation-π and D-A interactions is effectively avoided, enabling the construction of 2DSPs in aqueous solution. On this basis, the resultant 2DSPs possess boosted photocatalytic hydrogen evolution activity at a rate of 600 µmol g-1 h-1 , which is mainly ascribed to the specific stacking mode of cation-π/D-A motifs and the ordered 2D structures.

5.
Mol Plant ; 16(4): 694-708, 2023 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-36772793

RESUMO

Comprehensive utilization of cottonseeds is limited by the presence of pigment glands and its inclusion gossypol. The ideal cotton has glandless seeds but a glanded plant, a trait found in only a few Australian wild cotton species, including Gossypium bickii. Introgression of this trait into cultivated species has proved to be difficult. Understanding the biological processes toward pigment gland morphogenesis and the associated underlying molecular mechanisms will facilitate breeding of cultivated cotton varieties with the trait of glandless seeds and glanded plant. In this study, single-cell RNA sequencing (scRNA-seq) was performed on 12 222 protoplasts isolated from cotyledons of germinating G. bickii seeds 48 h after imbibition. Clustered into 14 distinct clusters unsupervisedly, these cells could be grouped into eight cell populations with the assistance of known cell marker genes. The pigment gland cells were well separated from others and could be separated into pigment gland parenchyma cells, secretory cells, and apoptotic cells. By integrating the pigment gland cell developmental trajectory, transcription factor regulatory networks, and core transcription factor functional validation, we established a model for pigment gland formation. In this model, light and gibberellin were verified to promote the formation of pigment glands. In addition, three novel genes, GbiERF114 (ETHYLENE RESPONSE FACTOR 114), GbiZAT11 (ZINC FINGER OF ARABIDOPSIS THALIANA 11), and GbiNTL9 (NAC TRANSCRIPTION FACTOR-LIKE 9), were found to affect pigment gland formation. Collectively, these findings provide new insights into pigment gland morphogenesis and lay the cornerstone for future cotton scRNA-seq investigations.


Assuntos
Gossypium , Transcriptoma , Gossypium/genética , Transcriptoma/genética , Austrália , Melhoramento Vegetal , Fatores de Transcrição/genética , Regulação da Expressão Gênica de Plantas/genética
6.
Psychon Bull Rev ; 30(3): 1065-1073, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36324029

RESUMO

Chinese is a visually complex logographic script that consists of square-shaped characters, with each character composed of strokes. Previous masked priming studies using single-character Chinese stroke neighbors (i.e., visually similar characters differing in only one or two strokes, e.g., /) have shown facilitatory or inhibitory priming effects. We tested whether the mixed pattern of stroke neighbor priming might be an instance of asymmetry in priming that has been observed previously with Japanese kana and Latin alphabets. Specifically, a prime lacking a stroke (or line segment) that is present in the target speeds up the recognition of its stroke neighbor almost as much as the identity prime (e.g., - = -), but not the converse (e.g., - >> -). Two experiments, one using a character match task and the second using lexical decision, showed a robust asymmetry in priming by stroke neighbors. The results suggest that the early letter identification process is similar across script types, as anticipated by the Noisy Channel model, which regards the first stage of visual word recognition as a language-universal perceptual process.


Assuntos
Idioma , Reconhecimento Visual de Modelos , Humanos , China , Mascaramento Perceptivo , Tempo de Reação , Leitura , Reconhecimento Psicológico , Redação
7.
Plant Commun ; 4(1): 100421, 2023 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-35949167

RESUMO

The pigment gland is a morphological characteristic of Gossypium and its related genera. Gossypium bickii (G1) is characterized by delayed pigment gland morphogenesis in the cotyledons. In this study, a reference-grade genome of G1 was generated, and comparative genomics analysis showed that G1 was closest to Gossypium australe (G2), followed by A- and D-genome species. Two large fragment translocations in chromosomes 5 and 13 were detected between the G genome and other Gossypium genomes and were unique to the G1 and G2 genomes. Compared with the G2 genome, two large fragment inversions in chromosomes 12 and 13 were detected in G1. According to the phylogeny, divergence time, and similarity analysis of nuclear and chloroplast genomes, G1 was formed by hybridization between Gossypium sturtianum (C1) and a common ancestor of G2 and Gossypium nelsonii (G3). The coordinated expression patterns of pigment gland formation (GoPGF) and gossypol biosynthesis genes in G1 were verified to be consistent with its phenotype, and nine genes that were related to the process of pigment gland formation were identified. A novel gene, GbiCYP76B6, regulated by GoPGF, was found to affect gossypol biosynthesis. These findings offer insights into the origin and evolution of G1 and its mechanism of pigment gland formation and gossypol biosynthesis.


Assuntos
Gossypium , Gossipol , Gossypium/genética , Hibridização Genética , Núcleo Celular , Evolução Molecular
8.
J Genet Genomics ; 50(3): 192-203, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-35940521

RESUMO

Many circular RNAs (circRNAs) are reported to be abnormally expressed during the progression of various tumors, and these circRNAs can be used as anti-tumor targets. Therefore, it is important to identify circRNAs that can be used effectively for the clinical diagnosis and treatment of colorectal cancer (CRC). Here, we report that hsa_Circ_0000826 (Circ_0000826), a circRNA with significantly reduced expression level in CRC tissues, is associated with a poor prognosis in patients. The silencing of Circ_0000826 promotes the proliferation of CRC cells. Conversely, the overexpression of Circ_0000826 restricted CRC cell proliferation both in vitro and in vivo. Furthermore, Circ_0000826 could target AU-rich element RNA-binding protein 1 (AUF1). AUF1, known as heterogeneous nuclear ribonucleoprotein D (hnRNP D), could bind to the c-MYC 3'-UTR and promote c-MYC expression. When Circ_0000826 binds to AUF1, it competitively inhibits the binding of AUF1 to the c-MYC 3'-UTR, which inhibits the c-MYC expression and cell proliferation. These results provide novel insights into the functional mechanism of Circ_0000826 action in CRC progression and indicate its potential use as a therapeutic target in CRC.


Assuntos
Neoplasias Colorretais , MicroRNAs , Humanos , RNA Circular/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Neoplasias Colorretais/patologia , MicroRNAs/genética
9.
Nanoscale ; 15(1): 376-386, 2022 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-36511884

RESUMO

In natural systems like photosynthetic organisms and photo-active enzymes, the spatial organization of chromophores is critical for efficient light harvesting and bio-catalysis. Inspired by nature, a novel modular nanoplatform with both biological imaging and therapeutic functions is constructed by taking advantage of the intrinsic core-shell structure of Fe-decorated carbon dots. Light-harvesting chromophores with deep-red photoluminescence are densely packed into the carbon core. Simultaneously, the atomically dispersed Fe3+ catalytic sites accounting for efficient conversion of H2O2 to ˙OH are discretely distributed on the shell. Precise control over their spatial distribution leads to the elegant integration and exciting interplay of the functional moieties. On the one hand, incorporating a catalysis shell enhances the emission of chromophores via synergistic shielding and rigidifying effects. On the other hand, visible light excitation of the chromophores significantly increases the catalytic activity and cytotoxicity against cancer cells, ascribed to the promotion of the charge transfer process. This nanoplatform exhibits excellent biocompatibility, bright red fluorescence, and light-regulated cytotoxicity for anti-cancer treatment, promising its applications in smart nanocatalytic medicines and efficient chemodynamic therapy.


Assuntos
Peróxido de Hidrogênio , Luz
10.
Artigo em Inglês | MEDLINE | ID: mdl-35805660

RESUMO

African swine fever (ASF) is a severe infectious disease affecting domestic and wild suids. Spatiotemporal dynamics analysis of the ASF is crucial to understanding its transmission. The ASF broke out in Vietnam in February 2019. The research on the spatiotemporal evolution characteristics of ASF in Vietnam is lacking. Spatiotemporal statistical methods, including direction analysis, spatial autocorrelation analysis, and spatiotemporal scan statistics were used to reveal the dynamics of the spatial diffusion direction and spatiotemporal aggregation characteristics of ASF in Vietnam. According to the cessation of the epidemic, it was divided into three phases: February to August 2019 (phase 1), April to December 2020 (phase 2), and January 2021 to March 2022 (phase 3). The ASF showed a significant spread trend from north to south in phase 1. The occurrence rate of the ASF aggregated spatially in phase 1 and became random in phases 2 and 3. The high-high ASF clusters (the province was a high cluster and both it and its neighbors had a high ASF occurrence rate) were concentrated in the north in phases 1 and 2. Four spatiotemporal high-risk ASF clusters were identified with a mean radius of 121.88 km. In general, there were significant concentrated outbreak areas and directional spread in the early stage and small-scale, high-frequency, and randomly scattered outbreaks in the later stage. The findings could contribute to a deeper understanding of the spatiotemporal spread of the ASF in Vietnam.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Epidemias , Febre Suína Africana/epidemiologia , Animais , Surtos de Doenças/veterinária , Sus scrofa , Suínos , Vietnã/epidemiologia
11.
Chem Sci ; 13(26): 7892-7899, 2022 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-35865886

RESUMO

Photoisomeric supramolecular assemblies have drawn enormous attention in recent years. Although it is a general rule that photoisomerization from a less to a more distorted isomer causes the destruction of assemblies, this photoisomerization process inducing a converse transition from irregular aggregates to regular assemblies is still a great challenge. Here, we report a converse sol-to-gel transition derived from the planar to nonplanar photoisomer conversion, which is in sharp contrast to the conventional light-induced gel collapse. A well-designed acylhydrazone-linked monomer is exploited as a photoisomer to realize the above-mentioned phase transition. In the monomer, imine is responsible for trans-cis interconversion and amide generates intermolecular hydrogen bonds enabling the photoisomerization-driven self-assembly. The counterintuitive feature of the sol-to-gel transition is ascribed to the partial trans → cis photoisomerization of acylhydrazone causing changes in stacking mode of monomers. Furthermore, the reversible phase transition is applied in the valves formed in situ in microfluidic devices, providing fascinating potential for miniature materials.

12.
Nat Commun ; 13(1): 3546, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35729110

RESUMO

Sequential energy transfer is ubiquitous in natural light harvesting systems to make full use of solar energy. Although various artificial systems have been developed with the biomimetic sequential energy transfer character, most of them exhibit the overall energy transfer efficiency lower than 70% due to the disordered organization of donor/acceptor chromophores. Herein a sequential energy transfer system is constructed via supramolecular copolymerization of σ-platinated (hetero)acenes, by taking inspiration from the natural light harvesting of green photosynthetic bacteria. The absorption and emission transitions of the three designed σ-platinated (hetero)acenes range from visible to NIR region through structural variation. Structural similarity of these monomers faciliates supramolecular copolymerization in apolar media via the nucleation-elongation mechanism. The resulting supramolecular copolymers display long diffusion length of excitation energy (> 200 donor units) and high exciton migration rates (~1014 L mol-1 s-1), leading to an overall sequential energy transfer efficiency of 87.4% for the ternary copolymers. The superior properties originate from the dense packing of σ-platinated (hetero)acene monomers in supramolecular copolymers, mimicking the aggregation mode of bacteriochlorophyll pigments in green photosynthetic bacteria. Overall, directional supramolecular copolymerization of donor/acceptor chromophores with high energy transfer efficiency would provide new avenues toward artificial photosynthesis applications.


Assuntos
Fotossíntese , Energia Solar , Biomimética/métodos , Transferência de Energia
13.
J Am Chem Soc ; 144(22): 9775-9784, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35621014

RESUMO

Chirality delivers substantial value to the field of supramolecular polymers, not only serving as a probe to monitor the dynamic assembly process but providing access to chiroptical materials. The current study demonstrates that, for supramolecular donor-acceptor copolymers, their comonomer organization modes can be greatly influenced by stereocommunication at the molecular level. The enantiopure N-[(1R or 1S)-phenylethyl]benzamides are incorporated into two structurally similar comonomers, locating between the π-aromatic diethynylacene core and the alkyl chain peripheries. Parallel arrangement of the stereogenic methyl units brings steric hindrance between the homochiral comonomers, which is relieved for the heterochiral comonomers due to the adoption of staggered arrangement. It consequently steers randomly mixed organization for the homochiral supramolecular copolymers within the nanofibers. In comparison, the heterochiral counterparts form nanoparticles in an alternate donor-acceptor organization manner. The variation of comonomer arrangement modes gives rise to distinct energy transfer efficiency at the supramolecular level. Overall, the elaborate manipulation of stereogenic centers in the comonomer structures exerts significant impacts on the characteristics of supramolecular copolymers, which could be useful for chiral sensing, recognition, and optoelectronic applications.

14.
Plants (Basel) ; 11(6)2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35336610

RESUMO

Gossypol, a terpenoid compound mainly synthesized in the cotton roots, acts as a phytoalexin in protecting the plants from biotic stress. Roots are critical for both the secondary metabolism and the growth of the plant. Light plays an important role in plant growth and material metabolism, however, the effect of root illumination (RI) on the cotton seedling growth and gossypol metabolism remains unclear. In the present study, the cotton genetic standard line TM-1 and four pairs of near-isogenic lines (NILs) were used as materials to study the impact of RI on cotton seedlings. Results showed that, compared with the cotton seedlings cultivated without RI, the photosynthetic rate, leaf area, and dry weight of roots and leaves were significantly increased, while the gossypol content in leaves and roots was significantly reduced in seedlings cultivated with RI. GO and KEGG enrichment analysis of the differentially expressed genes (DEGs) with and without RI both indicated that photosynthesis and terpenoid biosynthesis-related GO terms and pathways were significantly enriched, the expression profile confirmed that RI positively regulated the photosynthesis system and negatively affected the gossypol biosynthesis pathway in roots. This study revealed the effects of RI on seedlings' growth and gossypol biosynthesis in upland cotton, and provided important insights for the engineering of cotton with low gossypol accumulation.

15.
Environ Res ; 208: 112761, 2022 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-35065932

RESUMO

As a highly contagious disease, COVID-19 caused a worldwide pandemic and it is still ongoing. However, the infection in China has been successfully controlled although its initial transmission was also nationwide and has caused a serious public health crisis. The analysis on the early-stage COVID-19 transmission in China is worth investigating for its guiding significance on prevention to other countries and regions. In this study, we conducted the experiments from the perspectives of COVID-19 occurrence and intensity. We eliminated unimportant factors from 113 variables and applied four machine learning-based classification and regression models to predict COVID-19 occurrence and intensity, respectively. The influence of each important factor was analysed when applicable. Our optimal model on COVID-19 occurrence prediction presented an accuracy of 91.91% and the best R2 of intensity prediction reached 0.778. Linear regression-based model was identified as unable to fit and predict the intensity, and thus only the variable influence on COVID-19 occurrence can be explained. We found that (1) CO VID-19 was more likely to occur in prosperous cities closer to the epicentre and located on higher altitudes, (2) and the occurrence was higher under extreme weather and high minimum relative humidity. (3) Most air pollutants increased the risk of COVID-19 occurrence except NO2 and O3, and there existed a lag effect of 6-7 days. (4) NPIs (non-pharmaceutical interventions) did not show apparent effect until two weeks after.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , COVID-19 , Poluentes Atmosféricos/análise , Poluição do Ar/análise , COVID-19/epidemiologia , China/epidemiologia , Cidades , Humanos , Aprendizado de Máquina , Material Particulado/análise , SARS-CoV-2 , Fatores Sociais
16.
Br J Psychol ; 113(1): 153-175, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34435351

RESUMO

Although neuroimaging studies have shown that exogenous and endogenous attention are dissociable, only a few behavioural studies have explored their differential effects on visual sensitivity, and none have directly focused on visual appearance. Here, we show that exogenous and endogenous attention produces contrasting effects on apparent size. Participants performed a spatial pre-cueing comparative judgement task that had been frequently used to test the attentional effects on visual perception. The results showed that a smaller stimulus within the focus of exogenous attention was perceived to be equal in size as a larger unattended stimulus, whereas a larger stimulus within the focus of endogenous attention was perceived to be equal in size as a smaller unattended stimulus. In other words, exogenous attention increased the perceived size while endogenous attention decreased the perceived size. The contrasting effects may be attributed to the mechanism that exogenous attention favours parvocellular processing for which more neurons with smaller receptive fields (RFs) are activated for a given size, whereas endogenous attention favours magnocellular processing for which fewer neurons with larger RFs are activated. This finding shows that exogenous and endogenous attention acts differentially on size perception, and provides supportive evidence for the distinct mechanisms underlying the two types of attentional processing.


Assuntos
Atenção , Percepção de Tamanho , Sinais (Psicologia) , Humanos , Estimulação Luminosa , Percepção Espacial , Percepção Visual
17.
One Health ; 13: 100335, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34632042

RESUMO

Research on the impact of the environment on COVID-19 diffusion lacks a full-comprehensive perspective, and neglecting the multiplicity of the human-environment system can lead to misleading conclusions. We attempted to reveal all pre-existing environmental-to-human and human-to-human determinants that influence the transmission of COVID-19. As such, We estimated the daily case incidence ratios (CIR) of COVID-19 for prefectures across mainland China, and used a mixed-effects mixed-distribution model to study the association between the CIR and 114 factors related to climate, atmospheric environmental quality, terrain, population, economic, human mobility as well as non-pharmaceutical interventions (NPIs). Not only the changes in determinants over time as the pandemic progresses but also their lag and interaction effects were examined. CO, O3, PM10 and PM2.5 were found positively linked with CIR, but the effect of NO2 was negative. The temperature had no significant association with CIR, and the daily minimum humidity was a significant negatively predictor. NPIs' level was negatively associated with CIR until with a lag of 15 days. Higher accumulated destination migration scale flow from the epicenter and lower distance to the epicenter (DisWH) were associated with a higher CIR, however, the interaction between DisWH and the time was positive. The more economically developed and more densely populated cities have a higher probability of CIR occurrence, but they may not have a higher CIR intensity.The COVID-19 diffusion are caused by a multiplicity of environmental, economic, social factors as well as NPIs. First, multiple pollutants carried simultaneously on particulate matter affect COVID-19 transmission. Second, the temperature has a limited impact on the spread of the epidemic. Third, NPIs must last for at least 15 days or longer before the effect has been apparent. Fourth, the impact of population movement from the epicenter on COVID-19 gradually diminished over time and intraregional migration deserves more attention.

18.
Molecules ; 26(9)2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-34068830

RESUMO

Cooperative supramolecular polymerization of π-conjugated compounds into one-dimensional nanostructures has received tremendous attentions in recent years. It is commonly achieved by incorporating amide linkages into the monomeric structures, which provide hydrogen bonds for intermolecular non-covalent complexation. Herein, the effect of amide linkages is elaborately studied, by comparing supramolecular polymerization behaviors of two structurally similar monomers with the same platinum(II) acetylide cores. As compared to the N-phenyl benzamide linkages, N-[(1S)-1-phenylethyl] benzamide linkages give rise to effective chirality transfer behaviors due to the closer distances between the chiral units and the platinum(II) acetylide core. They also provide stronger intermolecular hydrogen bonding strength, which consequently brings higher thermo-stability and enhanced gelation capability for the resulting supramolecular polymers. Supramolecular polymerization is further strengthened by varying the monomers from monotopic to ditopic structures. Hence, with the judicious modulation of structural parameters, the current study opens up new avenues for the rational design of supramolecular polymeric systems.

19.
Angew Chem Int Ed Engl ; 60(25): 14076-14082, 2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-33829624

RESUMO

Near-infrared (NIR) responsiveness is important for various applications. Currently, single-photon NIR-responsive systems are rare compared to systems that display two-photon absorption and triplet-triplet annihilation processes. Supramolecular stacking of photo-responsive chromophores results in decreased efficiency due to space-confinement effects. Herein we show that σ-platination of pentacenes is a feasible protocol to build single-photon NIR-responsive systems, with advantages including a low HOMO-LUMO energy gap, high photochemical efficiency, and pathway specificity. The pentacene-to-endoperoxidation transformation is accompanied by color and absorbance changes. The high photo-oxygenation efficiency of σ-platinated pentacenes facilitates NIR responsiveness in one-dimensional supramolecular polymers, resulting in the disappearance of supramolecular chirality signals and disruption of self-assembled nanofibers. Overall, the σ-platination strategy opens up new avenues toward NIR photo-responsive materials at the molecular and supramolecular levels.

20.
Angew Chem Int Ed Engl ; 60(15): 8212-8219, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33450117

RESUMO

Phosphorescent materials with bright emission in versatile media are important for their practical applications, which require to lower the susceptibility of triplet excitons to surroundings. Herein a non-covalent clipping strategy has been developed to attain this objective, by designing a tweezer receptor to encapsulate PtII -based triplet emitters through two-fold π-stacking interactions. The PtII emitters display robust phosphorescence by virtue of synergistic rigidifying and shielding effects, which are hardly influenced by emitter concentration, oxygen content, and solvent polarity changes. The phosphorescent colors are elaborately modulated by varying ligand substitutes on PtII emitters. Circularly polarized phosphorescence is further amplified for chiral PtII emitters, by taking advantage of dual phosphorescence and chirality enhancement upon non-covalent tweezer complexation. Overall, the clipping approach paves the way for the development of high-performance phosphorescent materials with bright emission, environmental robustness, and facile color tunability.

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