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1.
Luminescence ; 39(1): e4674, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38286602

RESUMO

Recently, long persistent phosphors (LPPs) have attracted significant attention as promising candidates for biomedical applications. However, the serious decrease in luminescence intensity in tissue still remains a major challenge. Therefore, exploring more competitive LPPs and achieving reproducible tissue imaging is crucial. In this study, a new series of near-infrared (NIR) phosphors La3 Ga5 Sn1-x O14 :xCr3+ (x = 0.005-0.05) were synthesized using a high-temperature solid-state method. The as-synthesized samples were characterized using X-ray diffraction, diffuse/photoluminescence spectroscopy, fluorescence decay curves, and thermoluminescence spectroscopy. Upon excitation with ultraviolet light, strong emission bands were observed in the range 600-1200 nm with an optimal doping concentration of x = 0.02 mol. Moreover, La3 Ga5 SnO14 :Cr3+ exhibits persistent luminescence due to the presence of suitable energy traps, which prompted the phosphor to emit NIR light even after the removal of the excitation source.


Assuntos
Luminescência , Raios Ultravioleta , Difração de Raios X
2.
Bioorg Chem ; 136: 106547, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37105000

RESUMO

There is an urgent need to discover new antibacterial drugs and provide new treatment options for clinical antimicrobial resistance (AMR) pathogen infections. Inspired by the structural insights from analyzing the co-crystal structure of lefamulin with the ribosomes of S. aureus, a series of novel pleuromutilin derivatives of phenylene sulfide incorporated with urea moiety were designed and synthesized. The structure-activity relationship (SAR) study revealed that derivatives with urea in the meta position of phenylene sulfide had optimal antibacterial activities in vitro. Among them, 21h was the most potent one against Methicillin-resistant Staphylococcus aureus (MRSA) and clinical AMR Gram-positive bacteria with minimum inhibitory concentrations (MICs) in the range of 0.00195-0.250 µg/mL. And it possessed low resistance frequency, prolonged Post-Antibiotic Effect and the capability to overcome lefamulin-induced resistance. Furthermore, 21h exhibited potent antibacterial activity in vivo in both the thigh infection model and trauma infection model, representing a promising lead for the development of new antibiotics against Gram-positive pathogens, especially for AMR bacteria.


Assuntos
Antibacterianos , Staphylococcus aureus Resistente à Meticilina , Antibacterianos/farmacologia , Antibacterianos/química , Staphylococcus aureus , Relação Estrutura-Atividade , Testes de Sensibilidade Microbiana , Sulfetos/farmacologia , Pleuromutilinas
3.
Molecules ; 28(17)2023 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-37687096

RESUMO

A rigid polyurethane foam (RPUF) composite was prepared by compounding phytic acid (PA)-functionalized Graphite oxide (PA-GO) with flame-retardant poly (Ammonium phosphate) (APP) and expandable graphite (EG). The effects of PA-GO on the thermal, flame-retardant, and mechanical properties of RPUF were studied using a thermogravimetric analyzer, a limiting oxygen index (LOI) tester, a UL-94 vertical combustion tester, a cone calorimeter, scanning electron microscopy, and a universal tensile testing machine. The results indicated that there was a significant synergistic flame-retardant effect between PA-GO and the intumescent flame retardants (IFR) in the RPUF matrix. Compared with RPUF-1, the addition of 0.3 wt% PA-GO could increase LOI from 25.7% to 26.5%, increase UL-94 rating from V-2 to V-0, and reduce the peak heat release rate (PHRR) and total heat release rate (THR) by 28.5% and 22.2%, respectively. Moreover, the amount of residual char increased from 22.2 wt% to 24.6 wt%, and the char layer was continuous and dense, with almost no holes. Meanwhile, the loss of mechanical properties was apparently lightened.

4.
Angew Chem Int Ed Engl ; 62(38): e202309601, 2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37548132

RESUMO

High-voltage aqueous rechargeable energy storage devices with safety and high specific energy are hopeful candidates for the future energy storage system. However, the electrochemical stability window of aqueous electrolytes is a great challenge. Herein, inspired by density functional theory (DFT), polyethylene glycol (PEG) can interact strongly with water molecules, effectively reconstructing the hydrogen bond network. In addition, N, N-dimethylformamide (DMF) can coordinate with Zn2+ , assisting in the rapid desolvation of Zn2+ and stable plating/stripping process. Remarkably, by introducing PEG400 and DMF as co-solvents into the electrolyte, a wide electrochemical window of 4.27 V can be achieved. The shift in spectra indicate the transformation in the number and strength of hydrogen bonds, verifying the reconstruction of hydrogen bond network, which can largely inhibit the activity of water molecule, according well with the molecular dynamics simulations (MD) and online electrochemical mass spectroscopy (OEMS). Based on this electrolyte, symmetric Zn cells survived up to 5000 h at 1 mA cm-2 , and high voltage aqueous zinc ion supercapacitors assembled with Zn anode and activated carbon cathode achieved 800 cycles at 0.1 A g-1 . This work provides a feasible approach for constructing high-voltage alkali metal ion supercapacitors through reconstruction strategy of hydrogen bond network.

5.
Org Biomol Chem ; 19(7): 1616-1619, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-33533370

RESUMO

A novel and straightforward intramolecular cyclization of glycine derivatives to 2-substituted benzoxazoles through copper-catalyzed oxidative C-H/O-H cross-coupling was described. A variety of glycine derivatives involving short peptides underwent cross-dehydrogenative-coupling readily to afford diverse 2-substituted benzoxazoles. The synthetic method has the advantages of simple operation, broad substrate scope and mild reaction conditions, thus providing an alternative effective approach for benzoxazole construction.

6.
Nano Lett ; 20(5): 3798-3807, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32271024

RESUMO

A dendrite-free Li deposition strategy is developed with a composite separator of MnCO3 coated porous polypropylene. Mn2+ ions are preferentially reduced to form Mn nanoparticles on Li anodes, which helped to reduce the nucleation overpotential and achieve a dendrite-free deposition of Li bulky grains. When MnCO3 contacts the Li metal anode directly, an in situ artificial solid electrolyte interphase passivating layer was created from the reaction of Li metal, MnCO3 and liquid electrolyte. Li metal anodes show significantly improved stability for more than 2000 h of plating/stripping in Li||Li symmetric cells. The homemade ultrathin Li films on Cu foils (Li@Cu), obtained by electrochemical Li deposition with PP/MnCO3 separators, give enhanced cycling stability in LFP||Li@Cu cells. Combined with gel polymer electrolyte, the cycling stability of quasi-solid-state LFP||Li@Cu was further improved. This strategy for dendrite-free deposition via a composite separator provides a low-cost but efficient choice for alkaline metal batteries.

7.
Molecules ; 26(21)2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34770914

RESUMO

Eight new cytochalasins 1-8 and ten known analogs 9-18 were isolated from the endophytic fungus Phomopsis sp. xz-18. The planar structures of the cytochalasins were determined by HR-ESI-MS and NMR analysis. Compounds 1, 2, 9 and 10 were 5/6/6/7/5-fused pentacyclic cytochalasins; compounds 3 and 4 had conjugated diene structures in the macrocycle; and compound 6 had a ß,γ-unsaturated ketone. The absolute configuration of 6 was confirmed for the first time by the octant rule. The acid-free purification process proved that the pentacyclic system was a natural biosynthetic product and not an acid-mediated intramolecular cyclized artifact. The new compounds did not exhibit activities against human cancer cell lines in cytotoxicity bioassays or antipathogenic fungal activity, but compounds 1, 3 and 4 showed moderate antibacterial activity in disk diffusion assays.


Assuntos
Antifúngicos/farmacologia , Citocalasinas/farmacologia , Endófitos/efeitos dos fármacos , Phomopsis/efeitos dos fármacos , Antifúngicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Citocalasinas/química , Endófitos/metabolismo , Metabolismo Energético/efeitos dos fármacos , Humanos , Espectroscopia de Ressonância Magnética , Redes e Vias Metabólicas , Testes de Sensibilidade Microbiana , Estrutura Molecular , Phomopsis/metabolismo
8.
Int J Syst Evol Microbiol ; 70(9): 5026-5031, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32790600

RESUMO

A novel actinomycete, designated WYY166T, was isolated from the rhizosphere of Suaeda australis Moq. collected in Dongfang, PR China. The taxonomic position of this strain was investigated using a polyphasic approach. Phylogenetic analysis based on its 16S rRNA gene referred strain WYY166T to the genus Nonomuraea, and it was most closely related to the type strains Nonomuraea candida HMC10T, Nonomuraea turkmeniaca DSM 43926T, Nonomuraea maritima NBRC 106687T and Nonomuraea polychroma DSM 43925T (98.35, 97.60, 97.36 and 97.30% sequence similarity, respectively). Genome sequencing revealed a genome size of 11.27 Mbp and a G+C content of 71.10 mol%. The genome average nucleotide identity (ANI) values and the digital DNA - DNA hybridization (dDDH) values between strain WYY166T and the other species of the genus were found to be low (ANI 81.63~85.23 %, dDDH 23.6~31.6 %), suggesting that it represented a new species. The physiological evaluation showed that it had remarkable nitrate reduction activity. The whole-cell hydrolysates contained meso-diaminopimelic acid and madurose. The N-acyl type of muramic acid was acetyl. The major menaquinones were MK-9 (H4) (86.9 %) and MK-9 (H2) (13.1 %). The predominant fatty acids were iso-C16 : 0 (53.2 %), 10-methyl C17 : 0 (10.7 %), C17 : 1 ω6c (8.3 %) and iso-C16 : 1 h (7.3 %). These physiological, biochemical and chemotaxonomic data suggested that strain WYY166T should be classified as representing a novel species of the genus Nonomuraea, for which the name Nonomuraea nitratireducens sp. nov. is proposed. The type strain is WYY166T (=MCCC 1K03779T=KCTC 49343T).


Assuntos
Actinobacteria/classificação , Chenopodiaceae/microbiologia , Filogenia , Rizosfera , Microbiologia do Solo , Actinobacteria/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
9.
Bioorg Med Chem Lett ; 30(7): 127021, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32057583

RESUMO

Aberrant activation of NLRP3 inflammasome is present in a subset of acute and chronic inflammatory diseases. The NLRP3 inflammasome has been recognized as an attractive therapeutic target for developing novel and specific anti-inflammatory inhibitors. Cellular structure-activity relationship-guided optimization resulted in the identification of 4-oxo-2-thioxo-thiazolidinone derivative 9 as a selective and direct small-molecule inhibitor of NLRP3 with IC50 of 2.4 µM, possessing favorable ex vivo and in vivo pharmacokinetic properties. Compound 9 may represent a lead for the development of anti-inflammatory therapeutics for treating NLRP3-driven diseases.


Assuntos
Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Tiazolidinas/farmacologia , Animais , Descoberta de Drogas , Células HT29 , Humanos , Inflamassomos/efeitos dos fármacos , Estrutura Molecular , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Tiazolidinas/síntese química , Tiazolidinas/farmacocinética
10.
Org Biomol Chem ; 18(44): 9095-9099, 2020 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-33146660

RESUMO

The amide group has one of the most significant functionalities found in many natural products. Herein, low-nucleophilic amides are used in a Mannich-type reaction to synthesize N-acyl-protected amine derivatives. A highly efficient synthetic method utilizing simple aldehydes, N-substituted anilines, and amides as substrates was established through a one-pot amide pathway activated by hydrogen bonding between the ZnCl2 and amide under solvent-free conditions. This strategy can be broadly applied to medicinal chemistry. More importantly, compared with the previous Lewis acid catalyzed reaction, we proposed a new application of zinc chloride.

11.
Bioorg Chem ; 101: 103949, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32531507

RESUMO

A one-pot efficient biocatalytic strategy for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones was developed in a circulating microwave reactor selecting α-chymotrypsin as the promiscuous biocatalyst. In the circulating reaction system, the combination of microwave heating and external cooling could avoid the denaturation and inactivation of enzyme, and greatly improved the radiation power of microwave, thus improving the specific effects of microwave. During the reaction process, the microwave radiation power was automatically adjusted by adjusting the speed of the reaction mixture circulation. When the microwave power was maintained at 110 W, the best results could be obtained with the highest yield of 96% at 55 °C in 50 min, and the reaction had a wide range of substrates. But no obvious product was detected in a tank microwave reactor at 55 °C for 100 min, under this condition, the microwave power was maintained at about 3 W. As a contrast, the reaction only obtained 63% yield in 55 °C oil bath for 96 h.


Assuntos
Reatores Biológicos , Micro-Ondas , Animais , Biocatálise , Bovinos , Quimotripsina/metabolismo
12.
Mar Drugs ; 14(9)2016 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-27571085

RESUMO

By the method of ¹H NMR prescreening and tracing the diagnostic proton signals of the methyl groups, three additional new triquinane-type sesquiterpenoids-chondrosterins K-M (1-3) and the known sesquiterpenoid anhydroarthrosporone (4)-were isolated from the marine fungus Chondrostereum sp. Their structures were elucidated on the basis of MS, 1D, and 2D NMR data. Chondrosterin K is a rare hirsutane sesquiterpenoid, in which a methyl group was migrated from C-2 to C-6 and has a double bond between C-2 and C-3. Compounds 1-3 showed significant cytotoxicities against various cancer cell lines in vitro.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Polyporales/química , Sesquiterpenos/farmacologia , Animais , Antozoários/microbiologia , Antibióticos Antineoplásicos/química , Linhagem Celular Tumoral , Fermentação , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Conformação Molecular , Água do Mar/microbiologia , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Espectrometria de Massas por Ionização por Electrospray
13.
J Nat Prod ; 78(10): 2405-10, 2015 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-26378981

RESUMO

Aspertetranones A-D (1-4), four new highly oxygenated putative rearranged triketide-sesquiterpenoid meroterpenes, were isolated from the marine algal-associated fungus Aspergillus sp. ZL0-1b14. On the basis of a comprehensive spectroscopic analysis, the planar structures of aspertetranones were determined to possess an unusual skeleton in the terpenoid part. The relative and absolute configurations of the aspertetranones were assigned on the basis of NOESY analysis, X-ray crystallography, and circular dichroism spectroscopy. Compounds 1-4 were evaluated for anti-inflammatory activity in LPS-stimulated RAW264.7 macrophages. Aspertetranone D exhibited an inhibitory effect against IL-6 production with 69% inhibition at 40 µM.


Assuntos
Aspergillus/química , Sesquiterpenos/isolamento & purificação , Algoritmos , Animais , Anti-Inflamatórios/farmacologia , China , Cristalografia por Raios X , Interleucina-6/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Biologia Marinha , Camundongos , Conformação Molecular , Estrutura Molecular , Óxido Nítrico/análise , Ressonância Magnética Nuclear Biomolecular , Sesquiterpenos/química , Sesquiterpenos/farmacologia
14.
Sci Technol Adv Mater ; 15(4): 043502, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27877695

RESUMO

Precious metal nanoparticles are commonly used as the main active components of various catalysts. Given their high cost, limited quantity, and easy loss of catalytic activity under severe conditions, precious metals should be used in catalysts at low volumes and be protected from damaging environments. Accordingly, reducing the amount of precious metals without compromising their catalytic performance is difficult, particularly under challenging conditions. As multifunctional materials, core-shell nanoparticles are highly important owing to their wide range of applications in chemistry, physics, biology, and environmental areas. Compared with their single-component counterparts and other composites, core-shell nanoparticles offer a new active interface and a potential synergistic effect between the core and shell, making these materials highly attractive in catalytic application. On one hand, when a precious metal is used as the shell material, the catalytic activity can be greatly improved because of the increased surface area and the closed interfacial interaction between the core and the shell. On the other hand, when a precious metal is applied as the core material, the catalytic stability can be remarkably improved because of the protection conferred by the shell material. Therefore, a reasonable design of the core-shell catalyst for target applications must be developed. We summarize the latest advances in the fabrications, properties, and applications of core-shell nanoparticles in this paper. The current research trends of these core-shell catalysts are also highlighted.

15.
Innovation (Camb) ; 5(2): 100591, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38414519

RESUMO

Electricity is the lifeblood of modern society. However, the predominant source of electricity generation still relies on non-renewable fossil fuels, whose combustion releases greenhouse gases contributing to global warming. The increasing demand for energy and escalating environmental concerns necessitate proactive measures to develop innovative green energy technologies capable of both cooling the Earth and generating electricity. Here, we look forward to an interdisciplinary power system integrating solar absorbers, radiative coolers, and thermoelectric generators. This system can simultaneously harvest thermal energy from the sun and from cold space, thereby transforming the challenges posed by global warming into opportunities for the production of clean electricity. We underscore recent advancements in this field and address key challenges while also exploring forward-looking opportunities in the foreseeable future. The proposed integrated energy technology achieves uninterrupted power supply through the unrestricted capture of thermal energy, offering a robust alternative pathway for next-generation sustainable energy technologies.

16.
Int J Biol Macromol ; 267(Pt 2): 131586, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38615861

RESUMO

While hydrogels have potential for food packaging, limited research on hydrogels with excellent mechanical performance and antibacterial activity for preserving chicken breasts. Herein, we created antibacterial hydrogels by embedding methyl-ß-cyclodextrin/thyme oil inclusion complexes (MCD/TO-ICs) into a polyvinyl alcohol matrix containing dendrobium polysaccharides and guar gum in varying ratios using freeze-thaw cycling method. The resulting hydrogels exhibited a more compact structure than those without MCD/TO-ICs, enhancing thermal stability and increasing glass transition temperature due to additional intermolecular interactions between polymer chains that inhibited chain movement. XRD analysis showed no significant changes in crystalline phase, enabling formation of a 3D network through abundant hydrogen bonding. Moreover, the hydrogel demonstrated exceptional durability, with a toughness of 350 ± 25 kJ/m3 and adequate tearing resistance of 340 ± 30 J/m2, capable of lifting 3 kg weight, 1200 times greater than the hydrogel itself. Additionally, the hydrogels displayed excellent antimicrobial activity and antioxidant properties. Importantly, the hydrogels effectively maintained TVB-N levels and microbial counts within acceptable ranges, preserving sensory properties and extending the shelf life of chilled chicken breasts by four days. This study highlights the potential of MCD/TO-IC-incorporated polysaccharide hydrogels as safe and effective active packaging solutions for preserving chilled chicken in food industry.


Assuntos
Galinhas , Hidrogéis , Polissacarídeos , Animais , Hidrogéis/química , Hidrogéis/farmacologia , Polissacarídeos/química , Polissacarídeos/farmacologia , Conservação de Alimentos/métodos , beta-Ciclodextrinas/química , Embalagem de Alimentos/métodos , Galactanos/química , Galactanos/farmacologia , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Antibacterianos/farmacologia , Antibacterianos/química , Antioxidantes/farmacologia , Antioxidantes/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Mananas , Gomas Vegetais
17.
ACS Macro Lett ; 12(10): 1311-1316, 2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37708566

RESUMO

A polymer nanoparticle network using single-chain nanoparticles (SCNPs) as cross-links is designed. The experimental and theoretical study shows that incorporating SCNPs in polymer networks leads to smaller mesh size, faster terminal relaxation time, and reduced fluctuation among cross-links, resulting in a significant increase in shear storage modulus, and enhancement in tensile stress. Notably, the reversible single-chain collapse of SCNPs under thermal stimulation enables the polymer network to undergo coherent changes between two topological states, thereby exhibiting reversible transformations between soft and stiff states. This approach and finding can effectively tailor the mechanical properties of polymer networks, potentially leading to the development of intelligent, responsive materials.

18.
Nat Prod Res ; : 1-7, 2023 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-37132421

RESUMO

Three new compounds, apocimycin A-C, were identified from a saltern-derived Micromonospora sp. strain FXY415, isolated from Dongshi saltern, Fujian, China. Their planar structures and relative configuration were confirmed mainly by analysis of 1D- and 2D- NMR spectra. Three compounds belong to 4,6,8-trimythyl nona-2,7-dienoic acid derivatives, apocimycin A also has a phenoxazine nucleus. Apocimycin A-C exhibited weak cytotoxic and antimicrobial activities. Our research showed again that microbial communities in extreme environments are a potential resource in looking for new and bioactive led compounds.

19.
Front Bioeng Biotechnol ; 11: 1322514, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38155924

RESUMO

Liver disease has emerged as a significant worldwide health challenge due to its diverse causative factors and therapeutic complexities. The majority of liver diseases ultimately progress to end-stage liver disease and liver transplantation remains the only effective therapy with the limitations of donor organ shortage, lifelong immunosuppressants and expensive treatment costs. Numerous pre-clinical studies have revealed that extracellular vesicles released by mesenchymal stem cells (MSC-EV) exhibited considerable potential in treating liver diseases. Although natural MSC-EV has many potential advantages, some characteristics of MSC-EV, such as heterogeneity, uneven therapeutic effect, and rapid clearance in vivo constrain its clinical translation. In recent years, researchers have explored plenty of ways to improve the therapeutic efficacy and rotation rate of MSC-EV in the treatment of liver disease. In this review, we summarized current strategies to enhance the therapeutic potency of MSC-EV, mainly including optimization culture conditions in MSC or modifications of MSC-EV, aiming to facilitate the development and clinical application of MSC-EV in treating liver disease.

20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(3): 602-5, 2012 Mar.
Artigo em Zh | MEDLINE | ID: mdl-22582614

RESUMO

Self-designed identifying software for LIBS spectral line was introduced. Being integrated with LabVIEW, the soft ware can smooth spectral lines and pick peaks. The second difference and threshold methods were employed. Characteristic spectrum of several elements matches the NIST database, and realizes automatic spectral line identification and qualitative analysis of the basic composition of sample. This software can analyze spectrum handily and rapidly. It will be a useful tool for LIBS.

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