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1.
Nanoscale Horiz ; 9(4): 627-636, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38334479

RESUMO

Selective hydrogenation of CO2 to yield CH4 relies on the appropriate catalysts that can facilitate the cleavage of CO bonds and dissociative adsorption of H2. Ultrafine Rh nanoparticles loaded on silica nanospheres were used as a class of photocatalysts to significantly improve the selectivity and reaction rate of producing CH4 from the mixture of CO2 and H2 under the illumination of a broadband visible light source. The intense light scattering resonances in the silica nanospheres generate strong electric fields near the silica surface to enhance the light absorption power in the supported ultrafine Rh nanoparticles, promoting the efficiency of hot electron generation in the Rh nanoparticles. The interaction of the hot electrons with the adsorbate species on the Rh nanoparticle surface weakens the C-O bond to facilitate the deoxygenation of CO2, favoring the production of CH4 with a unity selectivity at a faster rate in the presence of surface adsorbed hydrogen (H*). The systematic studies on reaction kinetics and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy under different conditions, including various temperatures, illumination powers, and feeding gas compositions, reveal the reaction mechanism responsible for CO2 methanation and the role of photoillumination.

2.
MedComm (2020) ; 4(6): e462, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38156294

RESUMO

Mitochondria are multifaceted and dynamic organelles regulating various important cellular processes from signal transduction to determining cell fate. As dynamic properties of mitochondria, fusion and fission accompanied with mitophagy, undergo constant changes in number and morphology to sustain mitochondrial homeostasis in response to cell context changes. Thus, the dysregulation of mitochondrial dynamics and mitophagy is unsurprisingly related with various diseases, but the unclear underlying mechanism hinders their clinical application. In this review, we summarize the recent developments in the molecular mechanism of mitochondrial dynamics and mitophagy, particularly the different roles of key components in mitochondrial dynamics in different context. We also summarize the roles of mitochondrial dynamics and target treatment in diseases related to the cardiovascular system, nervous system, respiratory system, and tumor cell metabolism demanding high-energy. In these diseases, it is common that excessive mitochondrial fission is dominant and accompanied by impaired fusion and mitophagy. But there have been many conflicting findings about them recently, which are specifically highlighted in this view. We look forward that these findings will help broaden our understanding of the roles of the mitochondrial dynamics in diseases and will be beneficial to the discovery of novel selective therapeutic targets.

3.
Bioorg Chem ; 140: 106812, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37651894

RESUMO

A total of 17 structurally diverse clerodane diterpenoids, including ten undescribed clerodane diterpenoids (tinopanoids K-T, 1-10) and seven known compounds (11-17), were isolated from the vines and leaves of Tinospora crispa. Compound 3 has not only bear the dominant substituents of γ-hydroxy-α, ß-unsaturated-γ-lactone with anti-inflammatory activity, but also a ternary epoxy structure at C-3/C-4. The planar structures and relative configurations of the clerodane diterpenoids were elucidated by spectroscopic data interpretation. The absolute configurations of compounds 1, 4, 8 and 13 were determined by single-crystal X-ray crystallographic, while that of compound 3 was determined using computed ECD data and single crystal X-ray diffraction of related p-bromobenzoate ester (3a). Subsequently, all compounds were evaluated for their inhibitory effect on nitric oxide (NO) production of LPS-activated BV-2 cells, and compounds 3 and 8 exhibited better NO inhibitory potency, with IC50 values of 5.6 and 13.8 µM than the positive control minocycline (Mino, IC50 = 22.9 µM). The corresponding results of western blot analysis and qRT-PCR revealed that compound 3 can significantly inhibit the inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) protein expressions, mRNA levels of pro-inflammatory cytokins of tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6) and interleukin 1ß (IL-1ß). The underlying mechanism by which compound 3 exerted anti-neuroinflammatory effects was investigated by western blot and immunofluorescence assay, which suggested compound 3 inhibited LPS induced neuroinflammation via the suppression of toll-like receptor 4 (TLR4) dependent Signal Transducer and Activator of Transcription 3 (Stat3) and mitogen-activated protein kinase (MAPK) signaling pathways, and the activation of Heme Oxygenase-1 (HO-1) mediated signals.


Assuntos
Diterpenos Clerodânicos , Tinospora , Diterpenos Clerodânicos/farmacologia , Lipopolissacarídeos/farmacologia , Anti-Inflamatórios/farmacologia , Western Blotting
4.
Poult Sci ; 102(4): 102513, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36805395

RESUMO

Salmonella is an important zoonotic pathogen that not only endangers food safety and human health, but also causes considerable economic losses to the poultry industry. Therefore, it is essential to establish a rapid, sensitive, and specific diagnostic method for the early detection of Salmonella infection in poultry. In this study, we developed a novel enzyme-linked immunosorbent assay (ELISA) for the detection of anti-Salmonella antibodies using a recombinant SifA protein. Amino acid sequence comparison revealed that SifA is a relatively conserved secretory protein across Salmonella serotypes. Therefore, we hypothesized that SifA can serve as a detection antigen for diagnostic testing. The SifA protein was expressed in Escherichia coli and used as a coating antigen to establish an SifA-ELISA. Control sera from specific-pathogen-free (SPF) chickens infected with Salmonella or several other non-Salmonella pathogens were then tested using the SifA-ELISA. Specificity testing demonstrated that the SifA-ELISA could detect antibodies against 3 different serotypes of Salmonella, whereas antibodies against other non-Salmonella pathogens could not be detected. Compared to the SifA-ELISA, the Salmonella plate agglutination test (PAT) failed to detect antibodies in serum samples from chickens infected with Salmonella Typhimurium. This result suggests that our SifA-ELISA may be better than PAT at detecting Salmonella infection. Comparing clinical sera, we observed a similar rate of Salmonella positivity between SifA-ELISA and PAT (92.6%). In addition, anti-SifA antibodies were continuously detected during Salmonella infection of SPF chickens, demonstrating that SifA-ELISA could consistently detect high levels of antibodies for at least 8 wk. Furthermore, the intra-assay and interassay coefficients of variation (CV) of the SifA-ELISA were below 10%, which is considered acceptable. In summary, the SifA-ELISA established here is a promising and reliable method for detection of anti-Salmonella antibodies in poultry and may contribute to the early diagnosis of Salmonella infection.


Assuntos
Doenças das Aves Domésticas , Salmonelose Animal , Animais , Humanos , Aves Domésticas , Galinhas , Anticorpos Antibacterianos , Proteínas Recombinantes , Salmonella typhimurium , Ensaio de Imunoadsorção Enzimática/veterinária , Ensaio de Imunoadsorção Enzimática/métodos , Salmonelose Animal/diagnóstico , Doenças das Aves Domésticas/diagnóstico , Sensibilidade e Especificidade
5.
Eur J Med Chem ; 248: 115094, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36634454

RESUMO

Noncovalent inhibitors of p97 have entered clinical studies. Compared with noncovalent inhibitors, covalent inhibitors have unique advantages in maintaining inhibitory effect and improving the resistance of the target. We previously employed the activity-based protein profiling to definitely identify p97 as the protein target of FL-18 that has a unique scaffold of benpropargylamide coupled with an imidazole. In this study, we report a thorough structure-activity-relationship study involving the new scaffold. A total of three rounds of optimization led to the discovery of the most potent covalent inhibitor of p97 to date. A chemical proteomics study indicated that the newly-synthesized compounds still targeted the C522 residue of p97 and retained selectivity among the complicated whole proteome. This study provides a suite of new covalent inhibitors of p97 to assist in its biological study and drug discovery.


Assuntos
Inibidores Enzimáticos , Imidazóis , Adenosina Trifosfatases , Inibidores Enzimáticos/química , Imidazóis/farmacologia , Ligação Proteica , Relação Estrutura-Atividade
6.
Angew Chem Int Ed Engl ; 61(35): e202205839, 2022 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-35695784

RESUMO

Simultaneous transformation of CO2 and H2 O into syngas (CO and H2 ) using solar power is desirable for industrial applications. Herein, an efficient photocatalyst based on double-shelled nanoboxes, with an outer shell of hydroxy-rich nickel cobaltite nanosheets and an inner shell of Cu2 S (Cu2 S@ROH -NiCo2 O3 ), is prepared via a multistep templating strategy. The high performance of Cu2 S@ROH -NiCo2 O3 (7.1 mmol g-1 h-1 for CO; 2.8 mmol g-1 h-1 for H2 ) is attributed to the hierarchical hollow geometry and p-n heterojunction to promote light absorption and charge separation. Spectroscopic and theoretical analyses elucidate that the ROH -NiCo2 O3 surface enhances *CO2 adsorption and lowers energy barriers for CO2 -to-CO. Therefore, modulating the hydroxy contents of ROH -NiCo2 O3 can achieve broad CO/H2 ratios from 0.51 to 1.24. This work offers in-depth insights into adjustable syngas photosynthesis and generalized concepts of selective heterogeneous CO2 photoreduction beyond cobalt-based oxides.

7.
Sci Data ; 9(1): 205, 2022 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-35562358

RESUMO

The published map recording cultural sites in Xinjiang shows that there is a lack of data collection on the distribution of sites in the area, and no relevant data sets have been released. Existing written materials indicate that there are more cultural sites in this area. For this reason, we have collected and sorted out information. Our cultural site database provides the geographic location and corresponding geographic environment of each site in Xinjiang from the Paleolithic to the Bronze Age. The data record the human development and settlement process, settlement environment landscape characteristics, scale, type, quantity, and spatial distribution in Xinjiang in prehistoric China. These data not only are the basis for further understanding the spatial distribution of prehistoric humans in Xinjiang, but also provide references for understanding prehistoric human behavior and prehistoric man-land relationship, and the exchange of eastern and western civilizations. It is of great significance to modern social planning, site protection, and resource utilization.

8.
Sci Rep ; 12(1): 5072, 2022 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-35332226

RESUMO

When studying the human settlement process, it is of great significance to understand the prehistoric environment, economy and society by exploring the human-land relationship and the evolution of civilization reflected by the settlement environment. This paper explores the natural and social environmental preferences of early human settlements in Xinjiang, China, from the Palaeolithic to the Bronze Age (45 ka BP-2250 a BP). Through the characteristics of settlement preferences, the distribution of settlements is accurately predicted, and the relationship between settlement preferences and the evolution of the environment and civilization is verified and discussed. We summarize the needs and conditions of early human settlement from the perspectives of the social environment and natural environment and explain the stages, consistency and differentiation of the spatial and temporal evolution of settlement preferences with the interaction of adaptation and transformation. On this basis, we discuss the logical focuses and content of early human settlement preference research. This research provides a reference for the process, representation, driving mode, and research ideas of early human settlement preferences.


Assuntos
Meio Ambiente , Meio Social , China , Civilização , Humanos
9.
Chemosphere ; 291(Pt 2): 132963, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34800508

RESUMO

Microbial fuel cells (MFCs) are of great interest due to their capability to directly convert organic compounds to electric energy. In particular, MFCs technology showed great potential to directly harness the energy from xylose in the form of bioelectricity and biohydrogen simultaneously. Herein, we report a yeast strain of Cystobasidium slooffiae JSUX1 enabled the reduction and assembly of graphene oxide (GO) nanosheets into three-dimensional reduced GO (3D rGO) hydrogels on the surface of carbon felt (CF) anode. The autonomously self-modified 3D rGO hydrogel anode entitled the yeast-based MFCs with two times enhancement on bioelectricity and biohydrogen production from xylose. Further analysis demonstrated that the 3D rGO hydrogel attracted more yeast cells and reduced the interfacial charge transfer resistance, which was the underlying mechanism for the improvement of MFCs performance. This work offers a new strategy to reinforce the performance of yeast-based MFCs and provides a new opportunity to efficiently harvest energy from xylose.


Assuntos
Fontes de Energia Bioelétrica , Grafite , Eletrodos , Hidrogéis , Saccharomyces cerevisiae , Xilose
10.
Bioorg Med Chem Lett ; 52: 128403, 2021 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-34610423

RESUMO

Blocking the programmed cell death protein 1 (PD-1) and programmed death-ligand (PD-L1) interaction has emerged as one of the most promising treatments for cancer immunotherapy. A novel series of compounds bearing a benzo[d]isoxazole scaffold was developed as PD-1/PD-L1 inhibitors, among them, compound P20 exhibited the most potent inhibitory activity, with an IC50 value of 26.8 nM. The preliminary structure-activity relationship was also investigated. The docking analysis of compound P20 with the PD-L1 dimer complex (PDB ID: 5j89) indicated that compound P20 was bound to the PD-L1 dimer with high affinity. These results suggest that compound P20 is a promising lead compound for the development of inhibitors of the PD-1/PD-L1 interaction.


Assuntos
Antígeno B7-H1/antagonistas & inibidores , Desenho de Fármacos , Inibidores de Checkpoint Imunológico/farmacologia , Isoxazóis/farmacologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Antígeno B7-H1/metabolismo , Relação Dose-Resposta a Droga , Humanos , Inibidores de Checkpoint Imunológico/síntese química , Inibidores de Checkpoint Imunológico/química , Isoxazóis/síntese química , Isoxazóis/química , Simulação de Acoplamento Molecular , Estrutura Molecular , Receptor de Morte Celular Programada 1/metabolismo , Relação Estrutura-Atividade
11.
Bioorg Chem ; 114: 105034, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34116264

RESUMO

Blockade of the programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) signalling pathway is a promising tumour immunotherapeutic approach, and small molecule drugs have more advantages than monoclonal antibody macromolecules in clinical applications. Therefore, a series of 1-methyl-1H-pyrazolo[4,3-b]pyridine derivatives as PD-1/PD-L1 interaction novel small-molecule inhibitors were designed employing a ring fusion strategy. The inhibitory activity of compounds was evaluated by the HTRF assay, among which D38 was identified as the most potent PD-1/PD-L1 interaction inhibitor with an IC50 value of 9.6 nM. Furthermore, D38 exhibited prominent inhibitory activity against the PD-1/PD-L1 interaction with an EC50 value of 1.61 µM in a coculture model of PD-L1/TCR activator-expressing CHO cells and PD-1-expressing Jurkat cells. In addition, the preliminary structure-activity relationships (SARs) of compounds were elucidated, and the binding mode of D38 with the PD-L1 dimer was analysed by molecular docking. Overall, D38 could be employed as a prospective lead compound of PD-1/PD-L1 interaction inhibitors for further development.


Assuntos
Antígeno B7-H1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Pirazóis/farmacologia , Piridinas/farmacologia , Animais , Antígeno B7-H1/metabolismo , Células CHO , Cricetulus , Desenho de Fármacos , Humanos , Células Jurkat , Simulação de Acoplamento Molecular , Estrutura Molecular , Ligação Proteica , Pirazóis/síntese química , Pirazóis/metabolismo , Pirazóis/toxicidade , Piridinas/síntese química , Piridinas/metabolismo , Piridinas/toxicidade , Relação Estrutura-Atividade
12.
Eur J Med Chem ; 217: 113377, 2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-33770574

RESUMO

Blockade of the programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) pathway is an attractive strategy for immunotherapy. A novel series of compounds bearing a benzo[d]isothiazole scaffold were developed, among which CH20 exhibited promising activity, with an IC50 value of 8.5 nM. Further cell-based PD-1/PD-L1 blockade bioassays indicated that CH20 can inhibit the PD-1/PD-L1 interaction at the cellular level, with an EC50 value of 5.6 µM CH20 could have better potency in restoring the activity of effector cells, as the maximal luminescence values (RLUmax) of CH20 were equivalent to those of PD-L1 mAbs. The docking analysis of CH20 with the PD-L1 dimer complex (PDB ID: 6R3K) confirmed that CH20 is a promising lead compound for the development of inhibitors of the PD-1/PD-L1 interaction. The preliminary structure-activity relationship was investigated in this paper, with the aim of future drug development.


Assuntos
Antineoplásicos/farmacologia , Antígeno B7-H1/antagonistas & inibidores , Desenho de Fármacos , Inibidores de Checkpoint Imunológico/farmacologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Tiazóis/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Antígeno B7-H1/química , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cricetulus , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Inibidores de Checkpoint Imunológico/síntese química , Inibidores de Checkpoint Imunológico/química , Simulação de Acoplamento Molecular , Estrutura Molecular , Receptor de Morte Celular Programada 1/química , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/química
13.
RSC Adv ; 11(22): 13119-13123, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-35423854

RESUMO

Palladium-catalyzed 2-substituted quinazolin-4(3H)-one formation from readily available o-nitrobenzamides and alcohols using hydrogen transfer is described. Various quinazolin-4(3H)-ones were obtained in good to high yields. The cascade reaction including alcohol oxidation, nitro reduction, condensation, and dehydrogenation occurs without any added reducing or oxidizing agent.

14.
Nanomicro Lett ; 12(1): 41, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-34138277

RESUMO

Photothermal catalysis represents a promising strategy to utilize the renewable energy source (e.g., solar energy) to drive chemical reactions more efficiently. Successful and efficient photothermal catalysis relies on the availability of ideal photothermal catalysts, which can provide both large areas of catalytically active surface and strong light absorption power simultaneously. Such duplex requirements of a photothermal catalyst exhibit opposing dependence on the size of the catalyst nanoparticles, i.e., smaller size is beneficial for achieving higher surface area and more active surface, whereas larger size favors the light absorption in the nanoparticles. In this article, we report the synthesis of ultrafine RuOOH nanoparticles with a size of 2-3 nm uniformly dispersed on the surfaces of silica (SiOx) nanospheres of hundreds of nanometers in size to tackle this challenge of forming an ideal photothermal catalyst. The ultrasmall RuOOH nanoparticles exhibit a large surface area as well as the ability to activate adsorbed molecular oxygen. The SiOx nanospheres exhibit strong surface light scattering resonances to enhance the light absorption power of the small RuOOH nanoparticles anchored on the SiOx surface. Therefore, the RuOOH/SiOx composite particles represent a new class of efficient photothermal catalysts with a photothermal energy conversion efficiency of 92.5% for selective aerobic oxidation of benzyl alcohol to benzylaldehyde under ambient conditions.

15.
Nanoscale ; 11(36): 16723-16732, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31478541

RESUMO

The photocatalytic reduction of carbon dioxide on nanoparticles of group VIII transition metals represents an emerging research area in recent years because of their promise in transforming carbon dioxide, a greenhouse gas, into value-added chemicals and fuels with the energy input of light. This mini review summarizes the fundamentals of the reduction of carbon dioxide and addresses how the photoexcitation of the metal nanoparticles can influence the reactions. The important roles of non-thermal hot electrons and photothermal effect in the photocatalytic reduction of carbon dioxide are highlighted, and the recent research reported in the literature are overviewed. There are still challenges in characterizing the photocatalytic reactions to distinguish the contributions of non-thermal and photothermal effects.

16.
Front Chem ; 6: 494, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30386774

RESUMO

Silica nanoparticles, optically transparent in the visible spectral region, represent a class of dielectric antenna to tune the propagation and local field distribution of the visible light through surface scattering while the energy loss is minimized. The light scattering on the surface of silica nanoparticles include resonant scattering and random scattering that strongly depend on their geometry: spherical silica nanoparticles with the highest geometrical symmetry favors the light scattering resonances on the nanoparticle surfaces to promote resonant scattering while non-spherical silica nanoparticles mainly support random scattering. Both resonant scattering and random scattering of light on the silica nanoparticles are capable of enhancing the light absorption in quantum-sized metal nanocrystals attached to the surfaces of the silica nanoparticles. The contributions of resonant scattering and random scattering to the enhancement of light absorption have been compared and discussed. The understanding highlights the importance of the geometry of the silica nanoparticle antenna on the design and synthesis of composite materials for efficient light harvesting.

17.
Nanomicro Lett ; 10(4): 55, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30393703

RESUMO

Fast and sensitive detection of dilute rare earth species still represents a challenge for an on-site survey of new resources and evaluation of the economic value. In this work, a robust and low-cost protocol has been developed to analyze the concentration of rare earth ions using a smartphone camera. The success of this protocol relies on mesoporous silica nanoparticles (MSNs) with large-area negatively charged surfaces, on which the rare earth cations (e.g., Eu3+) are efficiently adsorbed through electrostatic attraction to enable a "concentrating effect". The initial adsorption rate is as fast as 4025 mg (g min)-1, and the adsorption capacity of Eu3+ ions in the MSNs is as high as 4730 mg g-1 (equivalent to ~ 41.2 M) at 70 °C. The concentrated Eu3+ ions in the MSNs can form a complex with a light sensitizer of 1,10-phenanthroline to significantly enhance the characteristic red emission of Eu3+ ions due to an "antenna effect" that relies on the efficient energy transfer from the light sensitizer to the Eu3+ ions. The positive synergy of "concentrating effect" and "antenna effect" in the MSNs enables the analysis of rare earth ions in a wide dynamic range and with a detection limit down to ~ 80 nM even using a smartphone camera. Our results highlight the promise of the protocol in fieldwork for exploring valuable rare earth resources.

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