Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 186
Filtrar
1.
Nat Commun ; 15(1): 3766, 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38704382

RESUMO

Coordination cages have been widely reported to bind a variety of guests, which are useful for chemical separation. Although the use of cages in the solid state benefits the recycling, the flexibility, dynamicity, and metal-ligand bond reversibility of solid-state cages are poor, preventing efficient guest encapsulation. Here we report a type of coordination cage-integrated solid materials that can be swelled into gel in water. The material is prepared through incorporation of an anionic FeII4L6 cage as the counterion of a cationic poly(ionic liquid) (MOC@PIL). The immobilized cages within MOC@PILs have been found to greatly affect the swelling ability of MOC@PILs and thus the mechanical properties. Importantly, upon swelling, the uptake of water provides an ideal microenvironment within the gels for the immobilized cages to dynamically move and flex that leads to excellent solution-level guest binding performances. This concept has enabled the use of MOC@PILs as efficient adsorbents for the removal of pollutants from water and for the purification of toluene and cyclohexane. Importantly, MOC@PILs can be regenerated through a deswelling strategy along with the recycling of the extracted guests.

2.
Adv Sci (Weinh) ; : e2308181, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459671

RESUMO

Developing synthetic molecular devices for controlling ion transmembrane transport is a promising research field in supramolecular chemistry. These artificial ion channels provide models to study ion channel diseases and have huge potential for therapeutic applications. Compared with self-assembled ion channels constructed by intermolecular weak interactions between smaller molecules or cyclic compounds, metallacage-based ion channels have well-defined structures and can exist as single components in the phospholipid bilayer. A naphthalene diimide-based artificial chloride ion channel is constructed through efficient subcomponent self-assembly and its selective ion transport activity in large unilamellar vesicles and the planar lipid bilayer membrane by fluorescence and ion-current measurements is investigated. Molecular dynamics simulations and density functional theory calculations show that the metallacage spans the entire phospholipid bilayer as an unimolecular ion transport channel. This channel transports chloride ions across the cell membrane, which disturbs the ion balance of cancer cells and inhibits the growth of cancer cells at low concentrations.

3.
Angew Chem Int Ed Engl ; 63(18): e202403149, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38421194

RESUMO

Expanded azahelicenes, as heteroanalogues of helically chiral helicenes, hold significant potential for chiroptical materials. Nevertheless, their investigation and research have remained largely unexplored. Herein, we present the facile synthesis of a series of expanded azahelicenes NHn (n=1-5) consisting of 11, 19, 27, 35, and 43 fused rings, mainly by Suzuki coupling followed by Bi(OTf)3-mediated cyclization of vinyl ethers. The structures of NH2, NH3 and NH4 were confirmed through X-ray crystallography analysis, and their (P)- and (M)- enantiomers were also isolated with chiral high performance liquid chromatography. The enantiomers exhibit large absorption (abs) and luminescence (lum) dissymmetry factors, with |gabs|max=0.044; |glum|max=0.003 for NH2, |gabs|max=0.048; |glum|=0.014 for NH3, and |gabs|max=0.043; |glum|max=0.021 for NH4, which are superior to their respective all-carbon analogues.

4.
Angew Chem Int Ed Engl ; 63(12): e202319502, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38279667

RESUMO

Aiming at the construction of novel stimuli-responsive fluorescent system with precisely tunable emissions, the typical 9,14-diphenyl-9,14-dihydrodibenzo[a, c]phenazine (DPAC) luminogen with attractive vibration-induced emission (VIE) behavior has been introduced into [2]rotaxane as a stopper. Taking advantage of their unique dual stimuli-responsiveness towards solvent and anion, the resultant [2]rotaxanes reveal both tunable VIE and switchable circularly polarized luminescence (CPL). Attributed to the formation of mechanical bonds, DPAC-functionalized [2]rotaxanes display interesting VIE behaviors including white-light emission upon the addition of viscous solvent, as evaluated in detail by femtosecond transient absorption (TA) spectra. In addition, ascribed to the regulation of chirality information transmission through anion-induced motions of chiral wheel, the resolved chiral [2]rotaxanes reveal unique switchable CPL upon the addition of anion, leading to significant increase in the dissymmetry factors (glum ) values with excellent reversibility. Interestingly, upon doping the chiral [2]rotaxanes in stretchable polymer, the blend films reveal remarkable emission change from white light to light blue with significant 6.5-fold increase in glum values up to -0.035 under external tensile stresses. This work provides not only a new design strategy for developing molecular systems with fluorescent tunability but also a novel platform for the construction of smart chiral luminescent materials for practical use.

5.
Chem Commun (Camb) ; 60(9): 1184-1187, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38193861

RESUMO

In this study, we designed and synthesized three conformation-adaptive Pd2L4- and Pd3L6-type coordination cages based on three dihydrophenazine-based ligands with different lengths. Interestingly, the shorter ligands L1 and L2 self-assembled into Pd2L4-type coordination cages while the longer ligand L3 formed Pd3L6-type one, mainly driven by the anion template effect. All coordination cages were confirmed through single-crystal X-ray diffraction, and their structural conformations underwent great changes compared with those of their corresponding ligands. Moreover, the conformational changes also significantly affected their photophysical and electrochemical properties which were distinct from their parent ligands.

6.
Angew Chem Int Ed Engl ; 63(4): e202315061, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-37966368

RESUMO

The development of multimode photopatterning systems based on supramolecular coordination complexes (SCCs) is considerably attractive in supramolecular chemistry and materials science, because SCCs can serve as promising platforms for the incorporation of multiple functional building blocks. Herein, we report a light-responsive liquid-crystalline metallacycle that is constructed by coordination-driven self-assembly. By exploiting its fascinating liquid crystal features, bright emission properties, and facile photocyclization capability, a unique system with spatially-controlled fluorescence-resonance energy transfer (FRET) is built through the introduction of a photochromic spiropyran derivative, which led to the realization of the first example of a liquid-crystalline metallacycle for orthogonal photopatterning in three-modes, namely holography, fluorescence, and photochromism.

7.
J Am Chem Soc ; 145(49): 26791-26798, 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-37972388

RESUMO

Knot-like structures were found to have interesting magnetic properties in condensed matter physics. Herein, we report on topologically chiral molecular knots as efficient spintronic chiral material. The discovery of the chiral-induced spin selectivity (CISS) effect opens the possibility of manipulating the spin orientation with soft materials at room temperature and eliminating the need for a ferromagnetic electrode. In the chiral molecular trefoil knot, there are no stereogenic carbon atoms, and chirality results from the spatial arrangements of crossings in the trefoil knot structures. The molecules show a very high spin polarization of nearly 90%, a conductivity that is higher by about 2 orders of magnitude compared with that of other chiral small molecules, and enhanced thermal stability. A plausible explanation for these special properties is provided, combined with model calculations, that supports the role of electron-electron interaction in these systems.

8.
BMC Psychiatry ; 23(1): 740, 2023 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-37821875

RESUMO

BACKGROUND: We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of blonanserin and risperidone for the treatment of schizophrenia and to provide reliable pharmacotherapeutic evidence for in the clinical treatment of schizophrenia. METHODS: We systematically searched the PubMed, Cochrane Library, Embase, Chinese Biomedical Literature Database (CBM), and China National Knowledge Infrastructure (CNKI) databases for head-to-head randomized controlled trials that compared blonanserin with risperidone for the treatment of schizophrenia. We extracted the following data: author, year, country, diagnostic criteria, sample size, course of treatment, dosage and outcomes. Our main endpoint was the changes in the Positive and Negative Syndrome Scale (PANSS) total scores. Meta-analysis of the included data was conducted by RevMan 5.3 software. We used the GRADE criteria to evaluate the certainty of the evidence. RESULTS: A total of 411 studies were initially; 8 trials were eligible and were included in our analysis (N = 1386 participants). Regarding efficacy, there was no difference in changes in the PANSS total scores between the two groups (P > 0.05). In terms of safety, compared to risperidone, the incidence of serum prolactin increases and weight gain in the blonanserin group was lower (P<0.05), but the incidence of extrapyramidal symptoms (EPS) was higher (P<0.05). CONCLUSION: The efficacy of blonanserin is similar to that of risperidone, but it is unclear whether blonanserin is more effective than risperidone at improving cognitive and social function. More high-quality studies are needed to verify the efficacy and safety of blonanserin in the future.


Assuntos
Antipsicóticos , Esquizofrenia , Humanos , Risperidona/efeitos adversos , Esquizofrenia/tratamento farmacológico , Antipsicóticos/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto
10.
Angew Chem Int Ed Engl ; 62(42): e202309619, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37610742

RESUMO

In this work, a facile and versatile strategy for the synthesis of contorted polycyclic aromatic hydrocarbons (PAHs) starting from the functionalized pentacene was established. A series of novel PAHs 1-4 and their derivatives were synthesized through a simple two-step synthesis procedure involving an intramolecular reductive Friedel-Crafts cyclization of four newly synthesized pentacene aldehydes 5-8 as a key step. All the molecules were confirmed by single-crystal X-ray diffraction and their photophysical and electrochemical properties were studied in detail. Interestingly, the most striking feature of 1-4 is their highly contorted carbon structures and the accompanying helical chirality. In particular, the optical resolution of 2 was successfully achieved by chiral-phase HPLC, and the enantiomers were characterized by circular dichroism and circularly polarized luminescence spectroscopy. Despite the highly nonplanar conformations, these contorted PAHs exhibited emissive properties with moderate-to-good fluorescence quantum yields, implying the potential utility of this series PAHs as high-quality organic laser dyes. By using a self-assembly method with the help of epoxy resin, a bottle microlaser based on 3 a was successfully illustrated with a lasing wavelength of 567.8 nm at a threshold of 0.3 mJ/cm2 . We believe that this work will shed light on the chemical versatility of pentacene and its derivatives in the construction of novel functionalized PAHs.

11.
Nat Commun ; 14(1): 5307, 2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37652914

RESUMO

Aiming at the creation of polymers with attractive dynamic properties, herein, rotaxane-branched dendronized polymers (DPs) with rotaxane-branched dendrons attached onto the polymer chains are proposed. Starting from macromonomers with both rotaxane-branched dendrons and polymerization site, targeted rotaxane-branched DPs are successfully synthesized through ring-opening metathesis polymerization (ROMP). Interestingly, due to the existence of multiple switchable [2]rotaxane branches within the attached dendrons, anion-induced reversible thickness modulation of the resultant rotaxane-branched DPs is achieved, which further lead to tunable thermal and rheological properties, making them attractive platform for the construction of smart polymeric materials.

12.
J Thorac Dis ; 15(6): 3372-3385, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37426151

RESUMO

Background: Data are quite sparse on the comprehensive analyses of pulmonary hypertension (PH) clinical trials worldwide. Methods: Information including participating countries (developed or developing), intervention type, trial size, PH categories, sponsorship, study phase, design strategies, and participants' demographic characteristics was extracted from PH trials registered on ClinicalTrials.gov from 1999 to 2021. Results: A total of 203 eligible clinical PH trials were screened, involving 23,402 participants, 67.8% of whom were females. Major clinical trials were designed to test drug interventions (95.6%), sponsored solely by industries in 59.5%, and targeting Group 1 PH patients in 76.3%. A large number of countries participated in PH clinical trials; however, most clinical trials were conducted in developed countries (84.2%). Developing countries were involved in clinical trials with larger sample sizes (P<0.01). Additionally, the differences between developed and developing countries centered on interventions, sponsors, PH groups, and design strategies. Furthermore, developing countries participated in multinational clinical trials with good quality, homogeneity, reliability, and data authenticity. All pediatric participants were diagnosed with Group 1 PH and were only involved in drug intervention trials. Children participated in far fewer clinical trials than adults (P<0.01), and most were enrolled in PH clinical trials in developed countries. Among the entire clinical trial population, younger patients with Group 1 PH had a much higher participation to prevalence ratio (PPR). There was no difference in women's PPRs between developed and developing countries. However, developing countries had higher PPRs for PH Groups I and IV (1.28 vs. 1.22, P<0.01), while developed countries had a lower PPR for Group III (P=0.02). Conclusions: PH is attracting increasing global attention, which is not at the same level of progress in developed and developing countries. Women and children with this disease have unique characteristics and require more attention.

13.
Angew Chem Int Ed Engl ; 62(36): e202308210, 2023 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-37452485

RESUMO

A series of covalent organic cages built from fluorophores capable of aggregation-induced emission (AIE) were elegantly prepared through the reduction of preorganized M2 (LA )3 (LB )2 -type metallacages, simultaneously taking advantage of the synthetic accessibility and well-defined shapes and sizes of metallacages, the good chemical stability of the covalent cages as well as the bright emission of AIE fluorophores. Moreover, the covalent cages could be further post-synthetically modified into an amide-functionalized cage with a higher quantum yield. Furthermore, these presented covalent cages proved to be good energy donors and were used to construct light-harvesting systems employing Nile Red as an energy acceptor. These light-harvesting systems displayed efficient energy transfer and relatively high antenna effect, which enabled their use as efficient photocatalysts for a dehalogenation reaction. This research provides a new avenue for the development of luminescent covalent cages for light-harvesting and photocatalysis.

14.
Ital J Pediatr ; 49(1): 86, 2023 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-37455314

RESUMO

BACKGROUND: Sandplay therapy is a psychotherapeutic technique, based on the psychoanalytic theory of the unconscious. Nearly a century after it was developed, sandplay can now be applied for the initial diagnosis tools for sand players. The goal of the current research is to demonstrate the role of sandplay in identifying internet-addicted adolescents in China. The study aims to evaluate the reliability and validity for sandplay as a diagnosis and evaluation tool for internet addiction symptoms, and to verify the consistency that exists between results based on sandplay pictures and those based on the Pathological Internet Usage Scale for Adolescents (APIUS). METHODS: The research was conducted with a 2 × 2 mixed factorial design - two types of participants (addicts and non-addicts) and two types of sandplay pictures (pictures for addicts and pictures for non-addicts). An absolute recognition-judgment paradigm was used along with eye movement evaluations to evaluate the existing initial sandplay picture system for internet addiction symptoms (22 sandplay pictures, 11 related to addicts and 11 related to non-addicts, respectively). Sixty Chinese adolescents were selected as the participants (30 as addicts and 30 as non-addicts) according to the APIUS. RESULTS: (1) The initial sandplay pictures for internet addicts are clearly preferred by Chinese internet-addicted adolescents, which are more familiar and easier to process; (2) Such pictures have a higher level of emotional arousal and cognitive resonance for the addicts; (3) Track and heat maps indicate that young internet addicts mainly fixate on the initial sandplay pictures for internet addicts. CONCLUSION: This initial sandplay picture system can be used to screen and identify young Chinese internet addicts based on symptoms, and the evaluation results are consistent with those based on the APIUS.


Assuntos
Movimentos Oculares , Transtorno de Adição à Internet , Ludoterapia , Adolescente , Humanos , População do Leste Asiático , Transtorno de Adição à Internet/diagnóstico , Reprodutibilidade dos Testes
15.
J Am Chem Soc ; 145(26): 14498-14509, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37328923

RESUMO

Aiming at the construction of novel soft actuators through the amplified motions of molecular machines at the nanoscale, the design and synthesis of a new family of photoresponsive rotaxane-branched dendrimers through an efficient controllable divergent approach was successfully realized for the first time. In the third-generation rotaxane-branched dendrimers, up to 21 azobenzene-based rotaxane units located at each branch, thus making them the first successful synthesis of light-control integrated artificial molecular machines. Notably, upon alternative irradiation with UV and visible light, photoisomerization of the azobenzene stoppers leads to the collective and amplified motions of the precisely arranged rotaxane units, resulting in controllable and reversible dimension modulation of the integrating photoresponsive rotaxane-branched dendrimers in solution. Moreover, novel macroscopic soft actuators were further constructed based on these photoresponsive rotaxane-branched dendrimers, which revealed fast shape transformation behaviors with an actuating speed up to 21.2 ± 0.2° s-1 upon ultraviolet irradiation. More importantly, the resultant soft actuators could produce mechanical work upon light control that has been further successfully employed for weight-lifting and cargo transporting, thus laying the foundation toward the construction of novel smart materials that can perform programmed events.

16.
Front Physiol ; 14: 1177297, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37101698

RESUMO

Chemosensation of tarsi provides moths with the ability to detect chemical signals which are important for food recognition. However, molecular mechanisms underlying the chemosensory roles of tarsi are still unknown. The fall armyworm Spodoptera frugiperda is a serious moth pest that can damage many plants worldwide. In the current study, we conducted transcriptome sequencing with total RNA extracted from S. frugiperda tarsi. Through sequence assembly and gene annotation, 23 odorant receptors 10 gustatory receptors and 10 inotropic receptors (IRs) were identified. Further phylogenetic analysis with these genes and homologs from other insect species indicated specific genes, including ORco, carbon dioxide receptors, fructose receptor, IR co-receptors, and sugar receptors were expressed in the tarsi of S. frugiperda. Expression profiling with RT-qPCR in different tissues of adult S. frugiperda showed that most annotated SfruORs and SfruIRs were mainly expressed in the antennae, and most SfruGRs were mainly expressed in the proboscises. However, SfruOR30, SfruGR9, SfruIR60a, SfruIR64a, SfruIR75d, and SfruIR76b were also highly enriched in the tarsi of S. frugiperda. Especially SfruGR9, the putative fructose receptor, was predominantly expressed in the tarsi, and with its levels significantly higher in the female tarsi than in the male ones. Moreover, SfruIR60a was also found to be expressed with higher levels in the tarsi than in other tissues. This study not only improves our insight into the tarsal chemoreception systems of S. frugiperda but also provides useful information for further functional studies of chemosensory receptors in S. frugiperda tarsi.

17.
World J Clin Cases ; 11(7): 1513-1520, 2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-36926403

RESUMO

BACKGROUND: Multiple primary malignant neoplasms (MPMNs) are rare, while synchronous MPMNs (SMPMNs) are even less common. Owing to the progression of medical technology and the extension of life expectancy, its incidence is gradually increasing. CASE SUMMARY: Although reports of breast and thyroid dual cancers are common, cases of an additional diagnosis of kidney primary cancer within the same individual are rare. CONCLUSION: We present a case of simultaneous MPMN of three endocrine organs, reviewing the relevant literature to enhance our understanding of SMPMNs while emphasizing the increasingly important need for accurate diagnosis and multidisciplinary management whenever this challenging situation arises.

18.
Eur J Surg Oncol ; 49(5): 964-973, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36958948

RESUMO

BACKGROUND: The Global Leadership Initiative on Malnutrition released a new version of the malnutrition criteria (GLIM criteria). To investigate the influence of the GLIM criteria on the long-term efficacy of radical gastric cancer surgery and establish a nomogram to predict the long-term prognosis of patients with gastric cancer. METHODS: A retrospective analysis of 1121 patients with gastric cancer in our department from 2010 to 2013 was performed. A nomogram was established to predict overall survival (OS) based on the GLIM criteria. Patients were divided into the low-risk group (LRG) and high-risk group (HRG) based on the established nomogram. RESULTS: Multivariate Cox regression analyses showed that GLIM criteria was an independent risk factor for the 5-year OS (HR = 1.768, Cl:1.341-2.329, p < 0.001). The C index, AUC and Time-ROC of the nomogram were significantly better than that of GLIM criteria and traditional criteria. The 5-year OS of patients receiving adjuvant chemotherapy in the high-risk group was significantly higher than that of patients without chemotherapy (45.77% vs. 24.73%,p < 0.001). CONCLUSIONS: The GLIM criteria independently influence the long-term outcome of patients after radical gastric cancer surgery. The established nomogram can predict the long-term survival of patients with gastric cancer, and postoperative adjuvant chemotherapy for HRG can significantly improve the 5-year OS of patients.


Assuntos
Intervalo Livre de Doença , Neoplasias Gástricas , Humanos , Quimioterapia Adjuvante , Desnutrição , Avaliação Nutricional , Estado Nutricional , Estudos Retrospectivos , Neoplasias Gástricas/cirurgia
19.
Angew Chem Int Ed Engl ; 62(27): e202301900, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-36959097

RESUMO

Developing a new strategy to improve the self-assembly efficiency of functional assemblies in a confined space and construct hybrid functional materials is a significant and fascinating endeavor. Herein, we present a highly efficient strategy for achieving the supramolecular self-assembly of well-defined metallacages in microdroplets through continuous-flow microfluidic devices. The high efficiency and versatility of this approach are demonstrated by the generation of five representative metallacages in different solvents containing water, DMF, acetonitrile, and methanol in a few minutes with nearly quantitative yields, in contrast to the yields obtained with the hour-scale reaction time in a batch reactor. A ring-opening catalytic reaction of the metallacages was selected as a model reaction for exploring supramolecular catalysis in microdroplets, whereby the catalytic yield was enhanced by 2.22-fold compared to that of the same reaction in the batch reactor. This work illustrates a new promising approach for the self-assembly of supramolecular systems.

20.
Chem Soc Rev ; 52(3): 1129-1154, 2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-36722920

RESUMO

Two-dimensional metallacycles and three-dimensional metallacages constructed by coordination-driven self-assembly have attracted much attention because they exhibit unique structures and properties and are highly efficient to synthesize. Introduction of switching into supramolecular chemistry systems is a popular strategy, as switching can endow systems with reversible features that are triggered by different stimuli. Through this strategy, novel switchable metallacycles and metallacages were generated, which can be reversibly switched into different stable states with distinct characteristics by external stimuli. Switchable metallacycles and metallacages exhibit versatile structures and reversible properties and are inherently dynamic and respond to artificial signals; thus, these structures have many promising applications in a wide range of fields, such as drug delivery, data processing, pollutant removal, switchable catalysis, smart functional materials, etc. This review focuses on the design of switchable metallacycles and metallacages, their switching behaviours and mechanisms triggered by external stimuli, and the corresponding structural changes and resultant properties and functions.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...