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1.
Small ; 20(34): e2401914, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38593297

RESUMO

Metal halide perovskite quantum dots (QDs) are widely studied in the field of photocatalytic CO2 due to their strong light absorption and long carrier migration length. However, it can not exhibit high catalytic performance because of the radiative recombination and the lack of effective catalytic sites. Metal organic frameworks (MOFs) encapsulated QDs can not only solve the aforementioned problems, but also maintain their own unique characteristics with ultra-high specific surfaces area and abundant metal sites. In this work, lead-free bismuth-based halide perovskite QDs are encapsulated into Zr-based MOF (UiO-66), which combines the advantages with high power conversion efficiency of QDs and the high surface area and porosity of UiO-66. In addition, benefiting from the close contact between the Cs3Bi2Br9 QDs and the UiO-66 enables the photogenerated electrons in the QDs to be rapidly transferred to the MOF. As a result, the Cs3Bi2Br9@UiO-66 composite exhibits a higher yield for photocatalytic CO2 reduction than that of the prepared large-sized composite of Cs3Bi2Br9 and UiO-66.

2.
Small ; 20(13): e2308767, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37949814

RESUMO

Dual single-atom catalysts (DSACs) are promising for breaking the scaling relationships and ensuring synergistic effects compared with conventional single-atom catalysts (SACs). Nevertheless, precise synthesis and optimization of DSACs with specific locations and functions remain challenging. Herein, dual single-atoms are specifically incorporated into the layer-stacked bulk-like carbon nitride, featuring in-plane three-coordinated Pd and interplanar four-coordinated Cu (Pd1-Cu1/b-CN) atomic sites, from both experimental results and DFT simulations. Using femtosecond time-resolved transient absorption (fs-TA) spectroscopy, it is found that the in-plane Pd features a charge decay lifetime of 95.6 ps which is much longer than that of the interplanar Cu (3.07 ps). This finding indicates that the in-plane Pd can provide electrons for the reaction as the catalytically active site in both structurally and dynamically favorable manners. Such a well-defined bi-functional cascade system ensures a 3.47-fold increase in CO yield compared to that of bulk-like CN (b-CN), while also exceeding the effects of single Pd1/b-CN and Cu1/b-CN sites. Furthermore, DFT calculations reveal that the inherent transformation from s-p coupling to d-p hybridization between the Pd site and CO2 molecule occurs during the initial CO2 adsorption and hydrogenation processes and stimulates the preferred CO2-to-CO reaction pathway.

3.
Bioorg Chem ; 149: 107499, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38815476

RESUMO

Janus Kinase 3 (JAK3) is important for the signaling transduction of cytokines in immune cells and is identified as potential target for treatment of rheumatoid arthritis (RA). Recently, we designed and synthesized two JAK3 inhibitors J1b and J1f, which featured with high selectivity but mild bioactivity. Therefore, in present study the structure was optimized to increase the potency. As shown in the results, most of the compounds synthesized showed stronger inhibitory activities against JAK3 in contrast to the lead compounds, among which 9a was the most promising candidate because it had the most potent effect in ameliorating carrageenan-induced inflammation of mice and exhibited low acute in vivo toxicity (MTD > 2 g/kg). Further analysis revealed that 9a was highly selective to JAK3 (IC50 = 0.29 nM) with only minimal effect on other JAK members (>3300-fold) and those kinases bearing a thiol in a position analogous to that of Cys909 in JAK3 (>150-fold). Meanwhile, the selectivity of JAK3 was also confirmed by PBMC stimulation assay, in which 9a irreversibly bound to JAK3 and robustly inhibited the signaling transduction with mild suppression on other JAKs. Moreover, it was showed that 9a could remarkably inhibited the proliferation of lymphocytes in response to concanavalin A and significantly mitigate disease severity in collagen induced arthritis. Therefore, present data indicate that compound 9a is a selective JAK3 inhibitor and could be a promising candidate for clinical treatment of RA.


Assuntos
Artrite Reumatoide , Janus Quinase 3 , Inibidores de Proteínas Quinases , Pirimidinas , Janus Quinase 3/antagonistas & inibidores , Janus Quinase 3/metabolismo , Artrite Reumatoide/tratamento farmacológico , Animais , Pirimidinas/química , Pirimidinas/farmacologia , Pirimidinas/síntese química , Humanos , Relação Estrutura-Atividade , Camundongos , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/síntese química , Estrutura Molecular , Relação Dose-Resposta a Droga , Pirróis/química , Pirróis/farmacologia , Pirróis/síntese química , Carragenina , Masculino , Artrite Experimental/tratamento farmacológico , Artrite Experimental/induzido quimicamente , Antirreumáticos/farmacologia , Antirreumáticos/química , Antirreumáticos/síntese química , Simulação de Acoplamento Molecular
4.
Mol Divers ; 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38709458

RESUMO

Nitric oxide (NO), the smallest signaling molecule known, can be excessively produced by overexpressed inducible nitric oxide synthase (iNOS), and eventually leads to multiple inflammatory related diseases. Thus, reducing the overexpression of NO represents as very potential anti-inflammatory strategy. In current study, a series of compounds were designed and synthesized based on the hybridization of 7H-pyrrolo[2,3-d]pyrimidine and cinnamamide fragments in order to develop novel NO production inhibitors. Among them, compound S2h displayed a vigorous inhibitory activity on NO production with an IC50 value of 3.21 ± 0.67 µM, which was much lower than that of the positive control Nω-nitro-L-arginine (L-NNA, IC50 = 28.36 ± 3.13 µM). Due to its obeying Lipinski's and Veber's rules that guarantee compounds with good oral bioavailability, S2h effectively suppressed the paw swelling in carrageenan-induced mice. Additionally, compound S2h formed clear interactions with iNOS protein according to the docking analysis. Therefore, compounds S2h is a promising lead compound for further development of potent iNOS inhibitors or anti-inflammatory agents.

5.
Chemistry ; 29(23): e202203706, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-36606747

RESUMO

Metal-organic frameworks (MOFs) materials have become a research forefront in the field of photocatalytic CO2 reduction attributed to their ultra-high specific surface area, adjustable structure, and abundant catalytic active sites. Particularly, MOFs can be facilely tuned to match CO2 photoreduction by utilizing post-modification of metal nodes, functionalization of organic linkers, and combination with other active materials. Herein, the recent advances in the construction strategy of MOF-based photocatalysts materials for CO2 reduction are highlighted. Some systematic modification strategies on MOF-based photocatalysts are also discussed, such as modification of metal sites and organic ligands, construction of heterojunction, introduction of single/dual-atom, and strain engineering. Finally, the future development directions of MOF-based photocatalysts in the field of CO2 reduction are presented.

6.
Ann Rheum Dis ; 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35595388

RESUMO

OBJECTIVE: To determine contributions and functions of autoantibodies (Abs) directed to the angiotensin receptor type 1 (AT1R), which are suggested to be involved in the pathogenesis of AT1R Abs-related diseases such as systemic sclerosis (SSc). METHODS: C57BL/6J mice were immunised with membrane-embedded human AT1R or empty membrane as control. Mice deficient for CD4+ or CD8+ T cells and B cells were immunised with membrane-embedded AT1R or an AT1R peptide proposed to be a dominant T cell epitope. A monoclonal (m)AT1R Ab was generated by hybridoma technique and transferred into C57BL/6J and AT1Ra/b knockout mice. The induced phenotype was examined by histology, immunohistochemistry, immunofluorescence, apoptosis assay and ELISA. In vitro, Abs responses towards AT1R were measured in cells of different origins and species. RESULTS: AT1R-immunised mice developed perivascular skin and lung inflammation, lymphocytic alveolitis, weak lung endothelial apoptosis and skin fibrosis accompanied by Smad2/3 signalling, not present in controls or mice deficient for CD4+ T and B cells. The AT1R peptide 149-172 provoked lung inflammation. Application of the mAT1R Ab induced skin and lung inflammation, not observed in AT1Ra/b knockout mice. In vitro, AT1R Abs activated rat cardiomyocytes and human monocytes, enhanced angiotensin II-mediated AT1R activation in AT1R-transfected HEK293 cells via AT1R binding and mAT1R Ab-activated monocytes mediated the induction of profibrotic markers in dermal fibroblasts. CONCLUSION: Our immunisation strategy successfully induced AT1R Abs, contributing to inflammation and, possibly, to fibrosis via activation of AT1R. Therefore, AT1R Abs are valuable targets for future therapies of SSc and other AT1R Ab-related diseases.

7.
Angew Chem Int Ed Engl ; 61(40): e202208414, 2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-35920387

RESUMO

Herein, using as-designed surface-mounted Bismuth-based metal-organic framework (Bi-MOF) on two-dimensional BiOBr support, as an operable platform for site-specific strain engineering to tailor the intermediate adsorption/desorption capability in CO2 photocatalytic conversion is proposed. Giant compressive strain up to 7.85 % is successfully induced on the surface-mounted Bi-MOF revealed by HRTEM images and geometric phase analysis as well as in situ Raman characterization, which largely downshifts the p band center of Bi nodes and intensifies their unsaturated state. In-depth explorations are put onto p-p (Bi 6p and CO2 /CO 2p) orbital hybridization. Taking the adsorption process as an example, the 1π and 7σ frontier molecule orbitals of CO2 2p for both the strain-free and strained models shift downwards the Fermi level, indicative of fast adsorption of CO2 . Meanwhile, strain engineering further induces new non-degenerate orbital overlapping near 1π and intensified overlapping of 7σ orbitals, stimulating the fast activation of absorbed CO2 molecules.

8.
Small ; 15(9): e1804545, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30680948

RESUMO

Developing cheap, abundant, and easily available electrocatalysts to drive the hydrogen evolution reaction (HER) at small overpotentials is an urgent demand of hydrogen production from water splitting. Molybdenum disulfide (MoS2 ) based composites have emerged as competitive electrocatalysts for HER in recent years. Herein, nickel@nitrogen-doped carbon@MoS2 nanosheets (Ni@NC@MoS2 ) hybrid sub-microspheres are presented as HER catalyst. MoS2 nanosheets with expanded interlayer spacings are vertically grown on nickel@nitrogen-doped carbon (Ni@NC) substrate to form Ni@NC@MoS2 hierarchical sub-microspheres by a simple hydrothermal process. The formed Ni@NC@MoS2 composites display excellent electrocatalytic activity for HER with an onset overpotential of 18 mV, a low overpotential of 82 mV at 10 mA cm-2 , a small Tafel slope of 47.5 mV dec-1 , and high durability in 0.5 H2 SO4 solution. The outstanding HER performance of the Ni@NC@MoS2 catalyst can be ascribed to the synergistic effect of dense catalytic sites on MoS2 nanosheets with exposed edges and expanded interlayer spacings, and the rapid electron transfer from Ni@NC substrate to MoS2 nanosheets. The excellent Ni@NC@MoS2 electrocatalyst promises potential application in practical hydrogen production, and the strategy reported here can also be extended to grow MoS2 on other nitrogen-doped carbon encapsulated metal species for various applications.

9.
J Neurol Neurosurg Psychiatry ; 90(6): 652-658, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30636700

RESUMO

BACKGROUND AND OBJECTIVE: Aetiology and pathogenesis of anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis, the most common autoimmune encephalitis, is largely unknown. Since an association of the disease with the human leucocyte antigen (HLA) has not been shown so far, we here investigated whether anti-NMDAR encephalitis is associated with the HLA locus. METHODS: HLA loci of 61 patients with anti-NMDAR encephalitis and 571 healthy controls from the Chinese Han population were genotyped and analysed for this study. RESULTS: Our results show that the DRB1*16:02 allele is associated with anti-NMDAR encephalitis (OR 3.416, 95% CI 1.817 to 6.174, p=8.9×10-5, padj=0.021), with a higher allele frequency in patients (14.75%) than in controls (4.82%). This association was found to be independent of tumour formation. Besides disease susceptibility, DRB1*16:02 is also related to the clinical outcome of patients during treatment, where patients with DRB1*16:02 showed a lower therapeutic response to the treatment than patients with other HLA alleles (p=0.033). Bioinformatic analysis using HLA peptide-binding prediction algorithms and computational docking suggested a close relationship between the NR1 subunit of NMDAR and the DRB1*16:02. CONCLUSIONS: This study for the first time demonstrates an association between specific HLA class II alleles and anti-NMDAR encephalitis, providing novel insights into the pathomechanism of the disease.


Assuntos
Encefalite Antirreceptor de N-Metil-D-Aspartato/genética , Cadeias HLA-DRB1/genética , Adolescente , Adulto , Alelos , Povo Asiático/genética , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Loci Gênicos/genética , Predisposição Genética para Doença/genética , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
Rheumatol Int ; 37(8): 1303-1310, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28434122

RESUMO

Pulmonary fibrosis (PF) is one of the leading causes of death in systemic sclerosis (SSc) patients. Although all SSc patients are characterized by autoimmunity, only part of them suffer from PF, suggesting that beside autoimmunity, some additional factors are involved in the initiation of PF in SSc. In this study, we aimed to identify genetic polymorphisms associated with the status of PF in SSc. We performed that an exhaustive search of the PubMed database was performed to identify eligible studies. Then, a comprehensive meta-analysis was performed by comparing PF+-SSc and PF--SSc patients to identify genetic polymorphisms associated with the status of PF in SSc. Among eight SSc-associated susceptibility polymorphisms which were applied for meta-analysis, IRF5 rs2004640 polymorphism (OR 1.12; 95% CI 1.02-1.22, P = 1.39 × 10-2), STAT4 rs7574865 polymorphism (OR 1.25; 95% CI 1.07-1.47, P = 5.3 × 10-3), IRAK1 rs1059702 polymorphism (OR 1.20; 95% CI 1.05-1.37, P = 0.007), and CTGF G-945C polymorphism (OR 1.42; 95% CI 1.18-1.71, P = 0.002) are associated with PF status in SSc, while TNFAIP3 rs5029939, CD226 rs763361, CD247 rs2056626, and IRF5 rs10488631 polymorphisms are not. Since IRF5, STAT4, and IRAK1 are important regulatory factors in the control of innate immune responses and CTGF is involved in the synthesis of extracellular matrix, these results suggest a role of the innate immunity and matrix compounds in the pathogenesis of PF in SSc.


Assuntos
Fator de Crescimento do Tecido Conjuntivo/genética , Fatores Reguladores de Interferon/genética , Quinases Associadas a Receptores de Interleucina-1/genética , Fibrose Pulmonar/genética , Fator de Transcrição STAT4/genética , Escleroderma Sistêmico/genética , Estudos de Casos e Controles , Marcadores Genéticos , Predisposição Genética para Doença , Genótipo , Humanos , Polimorfismo de Nucleotídeo Único , Escleroderma Sistêmico/complicações
11.
Biochim Biophys Acta ; 1838(8): 2019-25, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24780378

RESUMO

It has been shown that cholesterol modulates activity of protein kinase C (PKC), and PKC phosphorylates connexin 43 (Cx43) to regulate its function, respectively. However, it is not known whether cholesterol modulates function of Cx43 through regulating activity of PKC. In the present study, we demonstrated that cholesterol enrichment reduced the dye transfer ability of Cx43 in cultured H9c2 cells. Western blot analysis indicated that cholesterol enrichment enhanced the phosphorylated state of Cx43. Immunofluorescent images showed that cholesterol enrichment made the Cx43 distribution from condensed to diffused manner in the interface between the cells. In cholesterol enriched cells, PKC antagonists partially restored the dye transfer ability among the cells, downregulated the phosphorylation of Cx43 and redistributed Cx43 from the diffused manner to the condensed manner in the cell interface. In addition, reduction of cholesterol level suppressed PKC activity to phosphorylate Cx43 and restored Cx43 function in PKC agonist-treated cells. Furthermore, we demonstrated that cholesterol enrichment upregulated the phosphorylated state of Cx43 at Ser368, while PKC antagonists reversed the effect. Taken together, cholesterol level in the cells plays important roles in regulating Cx43 function through activation of the PKC signaling pathway.


Assuntos
Colesterol/farmacologia , Conexina 43/metabolismo , Junções Comunicantes/efeitos dos fármacos , Coração/efeitos dos fármacos , Proteína Quinase C/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Comunicação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Inibidores Enzimáticos/farmacologia , Imunofluorescência , Fosforilação/efeitos dos fármacos , Proteína Quinase C/antagonistas & inibidores , Ratos
12.
ChemSusChem ; : e202401810, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39347590

RESUMO

The photoelectrochemical (PEC) dual-electron pathway for water oxidation to produce hydrogen peroxide (H2O2) shows promising prospects. However, the dominance of the four-electron pathway leading to O2 evolution competes with this reaction, severely limiting the efficiency of H2O2 production. Here, we report a In2O3 passivator-coated BiVO4 (BVO) photoanode, which effectively enhances the selectivity and yield of H2O2 production via PEC water oxidation. Based on XPS spectra and DFT calculations, a heterojunction is formed between In2O3 and BVO, promoting the effective separation of interface and surface charges. More importantly, Mott-Schottky analysis and open-circuit potential measurements demonstrate that the In2O3 passivation layer on the BVO photoanode shifts the hole quasi-Fermi level towards the anodic direction, enhancing the oxidation level of holes. Additionally, the widening of the depletion layer and the flattening of the band bending on the In2O3-coated BVO photoanode favor the generation of H2O2 while suppressing the competitive O2 evolution reaction. In addition, the coating of In2O3 can also inhibit the decomposition of H2O2 and improve the stability of the photoanode. This work provides new perspectives on regulating PEC two/four-electron transfer for selective H2O2 production via water oxidation.

13.
Chem Asian J ; 19(15): e202400436, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38753576

RESUMO

Prolonging the lifetime of SAPO-34 catalysts and enhancing their olefin selectivity in methanol-to-olefin (MTO) reactions are critical yet challenging objectives. Here, a series of hierarchical SAPO-34 catalysts were synthesized using a straightforward recrystallization method. The incorporation of triethylamine into the recrystallization mother liquor facilitated the formation of mesopores, achieving a high solid yield of up to 90%. Notably, the addition of phosphoric acid and ammonium polyvinyl phosphate alcohol during the recrystallization process significantly enhanced the crystallinity and regularity of the hierarchical SAPO-34 crystals, consequently increasing the mesopore size. Due to the substantially improved mass transfer efficiency and moderated acidity, the SP34-0.14P-0.06R catalysts exhibited a prolonged lifetime of 344 min and 80.3% selectivity for ethylene and propylene at a weight hourly space velocity (WHSV) of 2 h-1. This performance markedly surpasses that of the parent SP34 catalyst, which demonstrated a lifetime of 136 min and a selectivity of 78.0%. Remarkably, the SP34-0.14P-0.06R maintained a lifetime of 166 min even at a high WHSV of 10 h-1, which is more than 5-fold greater than that of the original microporous SP34. This research offers valuable insights into the design and development of hierarchically porous zeolites with high yields, enhancing the efficiency of MTO reactions and other applications.

14.
Adv Sci (Weinh) ; 11(25): e2400730, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38654621

RESUMO

Metal-enzyme integrated catalysts (MEICs) that combine metal and enzyme offer great potential for sustainable chemoenzymatic cascade catalysis. However, rational design and construction of optimal microenvironments and accessible active sites for metal and enzyme in individual nanostructures are necessary but still challenging. Herein, Pd nanoparticles (NPs) and Candida antarctica lipase B (CALB) are co-immobilized into the pores and surfaces of covalent organic frameworks (COFs) with tunable functional groups, affording Pd/COF-X/CALB (X = ONa, OH, OMe) MEICs. This strategy can regulate the microenvironment around Pd NPs and CALB, and their interactions with substrates. As a result, the activity of the COF-based MEICs in catalyzing dynamic kinetic resolution of primary amines is enhanced and followed COF-OMe > COF-OH > COF-ONa. The experimental and simulation results demonstrated that functional groups of COFs modulated the conformation of CALB, the electronic states of Pd NPs, and the affinity of the integrated catalysts to the substrate, which contributed to the improvement of the catalytic activity of MEICs. Further, the MEICs are prepared using COF with hollow structure as support material, which increased accessible active sites and mass transfer efficiency, thus improving catalytic performance. This work provides a blueprint for rational design and preparation of highly active MEICs.

15.
ChemSusChem ; 17(12): e202301868, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38342756

RESUMO

Photocatalysis is an eco-friendly method to regenerate nicotinamide (NADH) cofactors, which is essential for biotransformation over oxidoreductases. Organic polymers exhibit high stability, biocompatibility and functional designability as photocatalysts, but still suffering from rapid charge recombination. Herewith the heteroatom structural engineering of donor-π-acceptor (D-π-A) conjugated porous polymers were conducted to promote charge transfer and photocatalytic NADH regeneration. The electron delocalization of polymer photocatalysts can be readily tuned by changing the electron density of the donor unit, leading to faster charge separation and better photocatalytic performance. The optimum sulfur-doped polymer exhibits the highest NADH regeneration yield of 47.4 % in 30 min and 94.1 % in 4 h, which can drive the biocatalytic C=C bond reduction of 2-cyclohexen-1-one by ene-reductase, giving the corresponding cyclohexanone yield of 96.7 % in 10 h. Moreover, the oxygen-doped polymer, from biomass derived 2,5-diformylfuran, exhibits comparable photocatalytic activity to the sulfur-doped CPP, suggesting the potential of furan as alternative donor unit to thiophene.

16.
Int J Biol Macromol ; 278(Pt 2): 134641, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39128755

RESUMO

Organometallic catalyst is extensively applied for the non-enzymatic regeneration of nicotinamide adenine dinucleotide (phosphate) cofactors, but suffering from the mutual inactivation with the enzymes in one pot. The spatially separated immobilization of organometallic catalyst and enzymes on suitable carriers not only can reduce their mutual inhabitation but also can enhance their reusability. Here in this work, we present a hierarchical porous COFs (HP-TpBpy) that incorporated with [(Cp*RhCl2]2 to generate the metalized COF, Rh-HP-TpBpy. The obtained Rh-HP-TpBpy exhibited superior performance in nicotinamide adenine dinucleotide (NADH) and nicotinamide adenine dinucleotide phosphate (NADPH) regeneration using formate as the hydride donor, significantly outperforming the natural formate dehydrogenases in cofactor preference toward NADP+. Subsequently, the Lactobacillus fermentum short-chain dehydrogenase/reductase 1 (LfSDR1) was then cross-linked into enzyme aggregates (CLEA) and immobilized on hierarchical Rh-HP-TpBpy, achieving the integrated chemoenzymatic catalyst, LfSDR1@Rh-HP-TpBpy, which can catalyze the chemoenzymatic reduction of halogenated aryl ketones and give the corresponding optically active halohydrins with high conversion and enantiomeric excess (ee) value up to 99 %. The LfSDR1@Rh-HP-TpBpy also exhibits largely enhanced stability compared with the free LfSDR1 and the CLEAs-LfSDR1, enabling its excellent reusability.


Assuntos
Enzimas Imobilizadas , Estruturas Metalorgânicas , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Estruturas Metalorgânicas/química , Catálise , NADP/química , NADP/metabolismo , Formiato Desidrogenases/química , Formiato Desidrogenases/metabolismo , NAD/química , Reagentes de Ligações Cruzadas/química , Biocatálise
17.
Nat Commun ; 14(1): 3901, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37400443

RESUMO

Understanding charge transfer dynamics and carrier separation pathway is challenging due to the lack of appropriate characterization strategies. In this work, a crystalline triazine/heptazine carbon nitride homojunction is selected as a model system to demonstrate the interfacial electron-transfer mechanism. Surface bimetallic cocatalysts are used as sensitive probes during in situ photoemission for tracing the S-scheme transfer of interfacial photogenerated electrons from triazine phase to the heptazine phase. Variation of the sample surface potential under light on/off confirms dynamic S-scheme charge transfer. Further theoretical calculations demonstrate an interesting reversal of interfacial electron-transfer path under light/dark conditions, which also supports the experimental evidence of S-scheme transport. Benefiting from the unique merit of S-scheme electron transfer, homojunction shows significantly enhanced activity for CO2 photoreduction. Our work thus provides a strategy to probe dynamic electron transfer mechanisms and to design delicate material structures towards efficient CO2 photoreduction.

18.
Front Immunol ; 14: 1196116, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37720234

RESUMO

Introduction: Natural products have been shown to an important source of therapeutics for human disease. In this study, we aimed to identify natural compounds as potential therapeutics for epidermolysis bullosa acquisita (EBA), an autoimmune disease caused by autoantibodies to type VII collagen (COL7). Methods: Utilizing an in vitro experimental system, we screened a natural product library composed of 800 pure compounds for their inhibitory effect on COL7-anti-COL7 IgG immune complex (IC)-mediated neutrophil activation and on neutrophil-mediated tissue damage. Results: Three natural compounds, namely luteolin peracetate, gossypol, and gossypolone were capable in inhibiting the IC-induced neutrophil adhesion and oxygen burst in vitro. Furthermore, luteolin peracetate and gossypolone were able to inhibit the anti-COL7 IgG induced dermal-epidermal separation in an ex vivo model for EBA. Discussion: In summary, this study demonstrates that luteolin peracetate and gossypolone are potential therapeutics for experimental EBA, which deserves further investigation.


Assuntos
Produtos Biológicos , Epidermólise Bolhosa Adquirida , Gossipol , Humanos , Complexo Antígeno-Anticorpo , Epidermólise Bolhosa Adquirida/tratamento farmacológico , Luteolina , Ativação de Neutrófilo , Imunoglobulina G
19.
Biomater Sci ; 11(15): 5232-5239, 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37338183

RESUMO

Piezoelectric polymer nanofibers are attracting increasing attention in the stimulation of cell growth and proliferation in tissue engineering and wound healing applications. However, their intrinsic non-biodegradability in vivo hinders widespread applications in the biological fields. Herein, we designed, synthesized and characterized composite materials of silk fibroin (SF)/LiNbO3 (LN) nanoparticles/MWCNTs by electrospinning technology, which displayed good biocompatibility and comparable piezoelectric properties with an output current of up to 15 nA and output voltage of up to 0.6 V under pressure stimulation, remaining stable after 200 cycles of pressure release without significant decay. Meanwhile, the mechanical properties of the LN/CNTs/SF-nanofiber scaffolds (SF-NFSs) are also enhanced, with a tensile strength reaching 12.84 MPa and an elongation at break reaching 80.07%. Importantly, in vitro cell proliferation experiments showed that the LN/CNTs/SF-NFSs promoted cell proliferation at a rate of 43%. Accordingly, the mouse wound healing experiments further indicated that they could accelerate the healing of skin wounds in mice that were continuously moving. Therefore, SF-based piezoelectric nanofibrous scaffolds exhibit potential for use in rapid wound healing and this sheds light on smart treatment for tissue engineering in biomedicine.


Assuntos
Fibroínas , Nanofibras , Camundongos , Animais , Alicerces Teciduais , Cicatrização , Engenharia Tecidual , Seda
20.
Heliyon ; 9(12): e22873, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38125480

RESUMO

Objectives: The spread of SARS-Cov-2 remains a global concern along with the emergence of variants. This study aims to characterize the epidemiological and clinical features of hospitalized patients who were dragonized with five different variants of SARS-CoV-2 during the past 3 years. Methods: This retrospective study recruited 432 COVID-19 patients who were hospitalized in the First Hospital of Changsha from January 2020 to August 2022. Clinical records on clinical symptoms, laboratory profiles, and chest CT images was collected. The epidemiological and clinical features were compared between COVID-19 patients infected with either the wild-type, Omicron variant or pre- Omicron variants (e.g., Alpha, Beta, Delta). Results: A total of 432 laboratory-confirmed COVID-19 inpatients were dialogized during three waves, including 247 cases during the wild-type transmission period, 65 cases during the transmission period of pre-Omicron variants, and 119 cases during the transmission period of Omicron variants. The proportion of moderately or severely ill inpatients showed a gradual decline from the wild-type transmission period to the Omicron transmission period. The common symptoms of inpatients infected with SARS-CoV-2 wildtype strains included fever (67.61 %), cough (57.89 %), fatigue (33.60 %), and shortness of breath (12.15 %). In contrast, patients infected with other variants mostly showed upper respiratory symptoms. Based on chest CT images, a lower degree of acute pulmonary infection was observed among inpatients infected with the Omicron variants than those infected with the wild-type strain (31.09 % vs 93.12 %, p-value<0.01). Conclusions: Compared with the wild-type strain, SARS-CoV-2 variants of concern, especially the Omicron variant, mostly caused a lower degree of acute pulmonary infection, indicating the reduced disease severity and mortality among hospitalized COVID-19 patients.

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