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1.
Nat Immunol ; 22(7): 851-864, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099918

RESUMO

Group 2 innate lymphoid cells (ILC2s) are essential to maintain tissue homeostasis. In cancer, ILC2s can harbor both pro-tumorigenic and anti-tumorigenic functions, but we know little about their underlying mechanisms or whether they could be clinically relevant or targeted to improve patient outcomes. Here, we found that high ILC2 infiltration in human melanoma was associated with a good clinical prognosis. ILC2s are critical producers of the cytokine granulocyte-macrophage colony-stimulating factor, which coordinates the recruitment and activation of eosinophils to enhance antitumor responses. Tumor-infiltrating ILC2s expressed programmed cell death protein-1, which limited their intratumoral accumulation, proliferation and antitumor effector functions. This inhibition could be overcome in vivo by combining interleukin-33-driven ILC2 activation with programmed cell death protein-1 blockade to significantly increase antitumor responses. Together, our results identified ILC2s as a critical immune cell type involved in melanoma immunity and revealed a potential synergistic approach to harness ILC2 function for antitumor immunotherapies.


Assuntos
Anticorpos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Inibidores de Checkpoint Imunológico/farmacologia , Interleucina-33/farmacologia , Linfócitos/efeitos dos fármacos , Melanoma Experimental/tratamento farmacológico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Neoplasias Cutâneas/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Quimiotaxia de Leucócito/efeitos dos fármacos , Citotoxicidade Imunológica/efeitos dos fármacos , Eosinófilos/efeitos dos fármacos , Eosinófilos/imunologia , Eosinófilos/metabolismo , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Linfócitos/imunologia , Linfócitos/metabolismo , Masculino , Melanoma Experimental/genética , Melanoma Experimental/imunologia , Melanoma Experimental/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/metabolismo , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/metabolismo
2.
J Am Chem Soc ; 146(13): 9434-9443, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38507716

RESUMO

Electrocatalytic synthesis of hydrogen peroxide (H2O2) in acidic media is an efficient and eco-friendly approach to produce inherently stable H2O2, but limited by the lack of selective and stable catalysts under industrial-relevant current densities. Herein, we report a diatomic cobalt catalyst for two-electron oxygen reduction to efficiently produce H2O2 at 50-400 mA cm-2 in acid. Electrode kinetics study shows a >95% selectivity for two-electron oxygen reduction on the diatomic cobalt sites. In a flow cell device, a record-high production rate of 11.72 mol gcat-1 h-1 and exceptional long-term stability (100 h) are realized under high current densities. In situ spectroscopic studies and theoretical calculations reveal that introducing a second metal into the coordination sphere of the cobalt site can optimize the binding strength of key H2O2 intermediates due to the downshifted d-band center of cobalt. We also demonstrate the feasibility of processing municipal plastic wastes through decentralized H2O2 production.

3.
Opt Express ; 32(10): 16867-16878, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38858883

RESUMO

In this paper, a highly integrated terahertz (THz) biosensor is proposed and implemented, which pioneered the preparation of low-temperature gallium arsenide (LT-GaAs) thin film photoconductive antenna (PCA) on the sensor for direct generation and detection of THz waves, simplifying complex terahertz time-domain spectroscopy (THz-TDS) systems. A latch type metasurface is deposited in the detection region to produce a resonance absorption peak at 0.6 THz that is independent of polarisation. Microfluidics is utilised and automatic injection is incorporated to mitigate the experimental effects of hydrogen bond absorption of THz waves in aqueous-based environment. Additionally, cell damage is minimised by regulating the cell flow rate. The biosensor was utilised to detect the concentration of three distinct sizes of bacteria with successful results. The assay was executed as a proof of concept to detect two distinct types of breast cancer cells. Based on the experimental findings, it has been observed that the amplitude and blueshift of the resonance absorption peaks have the ability to identify and differentiate various cancer cell types. The findings of this study introduce a novel approach for developing microfluidic THz metasurface biosensors that possess exceptional levels of integration, sensitivity, and rapid label-free detection capabilities.


Assuntos
Arsenicais , Técnicas Biossensoriais , Gálio , Espectroscopia Terahertz , Gálio/química , Arsenicais/química , Técnicas Biossensoriais/instrumentação , Espectroscopia Terahertz/instrumentação , Humanos , Desenho de Equipamento , Microfluídica/instrumentação
4.
Trends Immunol ; 42(12): 1113-1127, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34728143

RESUMO

Dendritic cells (DCs) are key immune sentinels that orchestrate protective immune responses against pathogens or cancers. DCs have evolved into multiple phenotypically, anatomically, and functionally distinct cell types. One of these DC types, Type 1 conventional DCs (cDC1s), are uniquely equipped to promote cytotoxic CD8+ T cell differentiation and, therefore, represent a promising target for harnessing antitumor immunity. Indeed, recent studies have highlighted the importance of cDC1s in tumor immunotherapy using immune checkpoint inhibitors. Here, we review the progress in defining the key developmental and functional attributes of cDC1s and the approaches to optimizing the potency of cDC1s for anticancer immunity.


Assuntos
Células Dendríticas , Neoplasias , Humanos , Imunoterapia , Ativação Linfocitária
5.
J Am Chem Soc ; 145(8): 4819-4827, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36790150

RESUMO

Heterogeneous catalysts containing diatomic sites are often hypothesized to have distinctive reactivity due to synergistic effects, but there are limited approaches that enable the convenient production of diatomic catalysts (DACs) with diverse metal combinations. Here, we present a general synthetic strategy for constructing a DAC library across a wide spectrum of homonuclear (Fe2, Co2, Ni2, Cu2, Mn2, and Pd2) and heteronuclear (Fe-Cu, Fe-Ni, Cu-Mn, and Cu-Co) bimetal centers. This strategy is based on an encapsulation-pyrolysis approach, wherein a porous material-encapsulated macrocyclic complex mediates the structure of DACs by preserving the main body of the molecular framework during pyrolysis. We take the oxygen reduction reaction (ORR) as an example to show that this DAC library can provide great opportunities for electrocatalyst development by unlocking an unconventional reaction pathway. Among all investigated sites, Fe-Cu diatomic sites possess exceptional high durability for ORR because the Fe-Cu pairs can steer elementary steps in the catalytic cycle and suppress the troublesome Fenton-like reactions.

6.
Nano Lett ; 22(4): 1557-1565, 2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35104146

RESUMO

The electrochemical reduction of CO2 to produce carbon-based fuels and chemicals possesses huge potentials to alleviate current environmental problems. However, it is confronted by great challenges in the design of active electrocatalysts with low overpotentials and high product selectivity. Here we report the atomic tuning of a single-Fe-atom catalyst with phosphorus (Fe-N/P-C) on commercial carbon black as a robust electrocatalyst for CO2 reduction. The Fe-N/P-C catalyst exhibits impressive performance in the electrochemical reduction of CO2 to CO, with a high Faradaic efficiency of 98% and a high mass-normalized turnover frequency of 508.8 h-1 at a low overpotential of 0.34 V. On the basis of ex-situ X-ray absorption spectroscopy measurements and DFT calculations, we reveal that the tuning of P in single-Fe-atom catalysts reduces the oxidation state of the Fe center and decreases the free-energy barrier of *CO intermediate formation, consequently maintaining the electrocatalytic activity and stability of single-Fe-atom catalysts.

7.
Angew Chem Int Ed Engl ; 62(13): e202217473, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36738169

RESUMO

Atomically dispersed metal catalysts show potential advantages in N2 reduction reaction (NRR) due to their excellent activity and efficient metal utilization. Unfortunately, the reported catalysts usually exhibit unsatisfactory NRR activity due to their poor N2 adsorption and activation. Herein, we report a novel Sn atomically dispersed protuberance (ADP) by coordination with substrate C and O to induce positive charge accumulation on Sn site for improving its N2 adsorption, activation and NRR performance. The extended X-ray absorption fine structure (EXAFS) spectra confirmed the local coordination structure of the Sn ADPs. NRR activity was significantly promoted via Sn ADPs, exhibiting a remarkable NH3 yield (RNH3 ) of 28.3 µg h-1 mgcat -1 (7447 µg h-1 mgSn -1 ) at -0.3 V. Furthermore, the enhanced N2 Hx intermediates was verified by in situ experiments, yielding consistent results with DFT calculation. This work opens a new avenue to regulate the activity and selectivity of N2 fixation.

8.
Angew Chem Int Ed Engl ; 62(52): e202314414, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-37946623

RESUMO

The integration of highly active single atoms (SAs) and atom clusters (ACs) into an electrocatalyst is critically important for high-efficiency two-electron oxygen reduction reaction (2e- ORR) to hydrogen peroxide (H2 O2 ). Here we report a tandem impregnation-pyrolysis-etching strategy to fabricate the oxygen-coordinated Fe SAs and ACs anchored on bacterial cellulose-derived carbon (BCC) (FeSAs/ACs-BCC). As the electrocatalyst, FeSAs/ACs-BCC exhibits superior electrocatalytic activity and selectivity toward 2e- ORR, affording an onset potential of 0.78 V (vs. RHE) and a high H2 O2 selectivity of 96.5 % in 0.1 M KOH. In a flow cell reactor, the FeSAs/ACs-BCC also achieves high-efficiency H2 O2 production with a yield rate of 12.51±0.18 mol gcat -1 h-1 and a faradaic efficiency of 89.4 %±1.3 % at 150 mA cm-2 . Additionally, the feasibility of coupling the produced H2 O2 and electro-Fenton process for the valorization of ethylene glycol was explored in detail. The theoretical calculations uncover that the oxygen-coordinated Fe SAs effectively regulate the electronic structure of Fe ACs which are the 2e- ORR active sites, resulting in the optimal binding strength of *OOH intermediate for high-efficiency H2 O2 production.

9.
Angew Chem Int Ed Engl ; 62(39): e202308044, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37483078

RESUMO

The electrochemical conversion of nitrate pollutants into value-added ammonia is a feasible way to achieve artificial nitrogen cycle. However, the development of electrocatalytic nitrate-to-ammonia reduction reaction (NO3 - RR) has been hampered by high overpotential and low Faradaic efficiency. Here we develop an iron single-atom catalyst coordinated with nitrogen and phosphorus on hollow carbon polyhedron (denoted as Fe-N/P-C) as a NO3 - RR electrocatalyst. Owing to the tuning effect of phosphorus atoms on breaking local charge symmetry of the single-Fe-atom catalyst, it facilitates the adsorption of nitrate ions and enrichment of some key reaction intermediates during the NO3 - RR process. The Fe-N/P-C catalyst exhibits 90.3 % ammonia Faradaic efficiency with a yield rate of 17980 µg h-1 mgcat -1 , greatly outperforming the reported Fe-based catalysts. Furthermore, operando SR-FTIR spectroscopy measurements reveal the reaction pathway based on key intermediates observed under different applied potentials and reaction durations. Density functional theory calculations demonstrate that the optimized free energy of NO3 - RR intermediates is ascribed to the asymmetric atomic interface configuration, which achieves the optimal electron density distribution. This work demonstrates the critical role of atomic-level precision modulation by heteroatom doping for the NO3 - RR, providing an effective strategy for improving the catalytic performance of single atom catalysts in different electrochemical reactions.

10.
Immunol Cell Biol ; 100(3): 160-173, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35048402

RESUMO

The role of RNA-binding proteins of the CCCH-containing family in regulating proinflammatory cytokine production and inflammation is increasingly recognized. We have identified ZC3H12C (Regnase-3) as a potential post-transcriptional regulator of tumor necrosis factor expression and have investigated its role in vivo by generating Zc3h12c-deficient mice that express green fluorescent protein instead of ZC3H12C. Zc3h12c-deficient mice develop hypertrophic lymph nodes. In the immune system, ZC3H12C expression is mostly restricted to the dendritic cell (DC) populations, and we show that DC-restricted ZC3H12C depletion is sufficient to cause lymphadenopathy. ZC3H12C can regulate Tnf messenger RNA stability via its RNase activity in vitro, and we confirmed the role of Tnf in the development of lymphadenopathy. Finally, we found that loss of ZC3H12C did not impact the outcome of skin inflammation in the imiquimod-induced murine model of psoriasis, despite Zc3h12c being identified as a risk factor for psoriasis susceptibility in several genome-wide association studies. Our data suggest a role for ZC3H12C in DC-driven skin homeostasis.


Assuntos
Linfadenopatia , Psoríase , Animais , Células Dendríticas , Estudo de Associação Genômica Ampla , Inflamação/patologia , Linfonodos/patologia , Linfadenopatia/patologia , Camundongos , Camundongos Endogâmicos C57BL , Pele/patologia
11.
J Cardiovasc Pharmacol ; 78(5): e690-e702, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34369901

RESUMO

ABSTRACT: This study aimed to investigate the effects of protopanaxadiol and protopanaxatriol ginsenosides on aconitine-induced cardiomyocyte injury and their regulatory mechanisms. The effects of ginsenosides on aconitine-induced cardiomyocyte damage were initially evaluated using H9c2 cells, and the molecular mechanisms were elucidated using molecular docking and western blotting. The changes in enzyme content, reactive oxygen species (ROS), calcium (Ca2+) concentration, and apoptosis were determined. Furthermore, an aconitine-induced cardiac injury rat model was established, the cardiac injury and serum physiological and biochemical indexes were measured, and the effects of ginsenoside were observed. The results showed that ginsenoside Rb1 significantly increased aconitine-induced cell viability, and its binding conformation with protein kinase B (AKT) protein was the most significant. In vitro and in vivo, Rb1 protects cardiomyocytes from aconitine-induced injury by regulating oxidative stress levels and maintaining Ca2+ concentration homeostasis. Moreover, Rb1 activated the PI3K/AKT pathway, downregulated Cleaved caspase-3 and Bax, and upregulated Bcl-2 expression. In conclusion, Rb1 protected H9c2 cells from aconitine-induced injury by maintaining Ca2+ homeostasis and activating the PI3K/AKT pathway to induce a cascade response of downstream proteins, thereby protecting cardiomyocytes from damage. These results suggested that ginsenoside Rb1 may be a potential cardiac protective drug.


Assuntos
Cálcio/metabolismo , Ginsenosídeos/farmacologia , Cardiopatias/prevenção & controle , Miócitos Cardíacos/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sapogeninas/farmacologia , Aconitina , Animais , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Cardiotoxicidade , Linhagem Celular , Modelos Animais de Doenças , Cardiopatias/induzido quimicamente , Cardiopatias/enzimologia , Cardiopatias/patologia , Homeostase , Masculino , Simulação de Acoplamento Molecular , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/patologia , Estresse Oxidativo/efeitos dos fármacos , Fosfatidilinositol 3-Quinase/metabolismo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais
12.
Small ; 16(13): e1906880, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32077593

RESUMO

It is an important issue that exposed active nitrogen atoms (e.g., edge or amino N atoms) in graphitic carbon nitride (g-C3 N4 ) could participate in ammonia (NH3 ) synthesis during the photocatalytic nitrogen reduction reaction (NRR). Herein, the experimental results in this work demonstrate that the exposed active N atoms in g-C3 N4 nanosheets can indeed be hydrogenated and contribute to NH3 synthesis during the visible-light photocatalytic NRR. However, these exposed N atoms can be firmly stabilized through forming BNC coordination by means of B-doping in g-C3 N4 nanosheets (BCN) with a B-doping content of 13.8 wt%. Moreover, the formed BNC coordination in g-C3 N4 not only effectively enhances the visible-light harvesting and suppresses the recombination of photogenerated carriers in g-C3 N4 , but also acts as the catalytic active site for N2 adsorption, activation, and hydrogenation. Consequently, the as-synthesized BCN exhibits high visible-light-driven photocatalytic NRR activity, affording an NH3 yield rate of 313.9 µmol g-1 h-1 , nearly 10 times of that for pristine g-C3 N4 . This work would be helpful for designing and developing high-efficiency metal-free NRR catalysts for visible-light-driven photocatalytic NH3 synthesis.

13.
Angew Chem Int Ed Engl ; 59(32): 13423-13429, 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32367577

RESUMO

Single-atom catalysts have demonstrated their superiority over other types of catalysts for various reactions. However, the reported nitrogen reduction reaction single-atom electrocatalysts for the nitrogen reduction reaction exclusively utilize metal-nitrogen or metal-carbon coordination configurations as catalytic active sites. Here, we report a Fe single-atom electrocatalyst supported on low-cost, nitrogen-free lignocellulose-derived carbon. The extended X-ray absorption fine structure spectra confirm that Fe atoms are anchored to the support via the Fe-(O-C2 )4 coordination configuration. Density functional theory calculations identify Fe-(O-C2 )4 as the active site for the nitrogen reduction reaction. An electrode consisting of the electrocatalyst loaded on carbon cloth can afford a NH3 yield rate and faradaic efficiency of 32.1 µg h-1 mgcat. -1 (5350 µg h-1 mgFe -1 ) and 29.3 %, respectively. An exceptional NH3 yield rate of 307.7 µg h-1 mgcat. -1 (51 283 µg h-1 mgFe -1 ) with a near record faradaic efficiency of 51.0 % can be achieved with the electrocatalyst immobilized on a glassy carbon electrode.

14.
Chemistry ; 25(23): 5904-5911, 2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-30767346

RESUMO

Electrosynthesis of NH3 through the N2 reduction reaction (NRR) under ambient conditions is regarded as promising technology to replace the industrial energy- and capital-intensive Haber-Bosch process. Herein, a room-temperature spontaneous redox approach to fabricate a core-shell-structured Au@CeO2 composite, with Au nanoparticle sizes below about 10 nm and a loading amount of 3.6 wt %, is reported for the NRR. The results demonstrate that as-synthesized Au@CeO2 possesses a surface area of 40.7 m2 g-1 and a porous structure. As an electrocatalyst, it exhibits high NRR activity, with an NH3 yield rate of 28.2 µg h-1 cm-2 (10.6 µg h-1 mg-1 cat. , 293.8 µg h-1 mg-1 Au ) and a faradaic efficiency of 9.50 % at -0.4 V versus a reversible hydrogen electrode in 0.01 m H2 SO4 electrolyte. The characterization results reveal the presence of rich oxygen vacancies in the CeO2 nanoparticle shell of Au@CeO2 ; these are favorable for N2 adsorption and activation for the NRR. This has been further verified by theoretical calculations. The abundant oxygen vacancies in the CeO2 nanoparticle shell, combined with the Au nanoparticle core of Au@CeO2 , are electrocatalytically active sites for the NRR, and thus, synergistically enhance the conversion of N2 into NH3 .

15.
Bioorg Med Chem ; 27(18): 4211-4218, 2019 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-31395508

RESUMO

OBJECTIVE: To study the changes of ginsenoside content in different proportion of Panax ginseng-Angelica sinensis (GA) co-decoction, and to explore the amelioration of hematopoietic function in mice after combined use of the two drugs. The active ingredient profiles in P. ginseng single decoction and co-decoction of GA were determined by high performance liquid chromatography (HPLC). The experimental pharmacology method was used to explore the effect of GA co-decoction on the hematopoietic function of chemotherapy mice. RESULTS: The active ingredient profiles of the co-decoction of GA significantly changed compared with those of the single decoction. Compared with GA1:0 (single decoction of Panax ginseng), the routine ginsenosides of all proportions of GA decreased significantly, but the proportion of rare ginsenosides increased significantly. The changes of contents of rare ginsenosides of GA were basically consistent with the trends of effects on the myelosuppression induced by CY. Compared with the model group, GA significantly increased the number of bone marrow nucleated cells, thymus index, peripheral blood leukocytes and platelets, and significantly reduced the spleen index. Moreover, GA could promote G1 phase bone marrow cells to enter the cell cycle, increase the proportion of S phase cells and G2/M phase cells, and increase the cell proliferation index. CONCLUSION: GA can ameliorate the hematopoietic function of mice after chemotherapy, and GA2:3, GA3:2 were the best, which may be due to the changes of the pharmacodynamic material basis of GA after compatibility. All these results implied that GA may be an ideal drug and food supplement for the treatment of toxic and side effects of chemotherapeutic drugs.


Assuntos
Angelica sinensis/química , Medicamentos de Ervas Chinesas/uso terapêutico , Ginsenosídeos/uso terapêutico , Hematopoese/efeitos dos fármacos , Panax/química , Animais , Medicamentos de Ervas Chinesas/farmacologia , Ginsenosídeos/farmacologia , Camundongos
16.
Angew Chem Int Ed Engl ; 58(46): 16644-16650, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31497911

RESUMO

As a metal-free nitrogen reduction reaction (NRR) photocatalyst, g-C3 N4 is available from a scalable synthesis at low cost. Importantly, it can be readily functionalized to enhance photocatalytic activities. However, the use of g-C3 N4 -based photocatalysts for the NRR has been questioned because of the elusive mechanism and the involvement of N defects. This work reports the synthesis of a g-C3 N4 photocatalyst modified with cyano groups and intercalated K+ (mCNN), possessing extended visible-light harvesting capacity and superior photocatalytic NRR activity (NH3 yield: 3.42 mmol g-1 h-1 ). Experimental and theoretical studies suggest that the -C≡N in mCNN can be regenerated through a pathway analogous to Mars van Krevelen process with the aid of the intercalated K+ . The results confirm that the regeneration of the cyano group not only enhances photocatalytic activity and sustains the catalytic cycle, but also stabilizes the photocatalyst.

17.
Adv Mater ; : e2404188, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38810207

RESUMO

The emerging market demand for high-energy-density of energy storage devices is pushing the disposal of end-of-life LiCoO2 (LCO) to shift toward sustainable upgrading into structurally stable high-voltage cathode materials. Herein, an integrated bulk and surface commodification strategy is proposed to render spent LCO (S-LCO) to operate at high voltages, involving bulk Mn doping, near surface P gradient doping, and Li3PO4/CoP (LPO/CP) coating on the LCO surface to yield upcycled LCO (defined as MP-LCO@LPO/CP). Benefiting from hybrid surface coating with Li+-conductive Li3PO4 (LPO) and electron conductive CoP (CP) coupled with Mn and P co-doping, the optimized MP-LCO@LPO/CP cathode exhibits enhanced high-voltage performance, delivering an initial discharge capacity of 218.8 mAh g-1 at 0.2 C with excellent capacity retention of 80.9% (0.5 C) after 200 cycles at a cut-off voltage of 4.6 V, along with 96.3% of capacity retention over 100 cycles at 4.5 V. These findings may afford meaningful construction for the upcycling of commercial S-LCO into next-generation upmarket cathode materials through the elaborate surface and bulk modification design.

18.
Front Immunol ; 14: 1182553, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37520521

RESUMO

Dendritic cells (DCs) are sentinel immune cells that form a critical bridge linking the innate and adaptive immune systems. Extensive research addressing the cellular origin and heterogeneity of the DC network has revealed the essential role played by the spatiotemporal activity of key transcription factors. In response to environmental signals DC mature but it is only following the sensing of environmental signals that DC can induce an antigen specific T cell response. Thus, whilst the coordinate action of transcription factors governs DC differentiation, sensing of environmental signals by DC is instrumental in shaping their functional properties. In this review, we provide an overview that focuses on recent advances in understanding the transcriptional networks that regulate the development of the reported DC subsets, shedding light on the function of different DC subsets. Specifically, we discuss the emerging knowledge on the heterogeneity of cDC2s, the ontogeny of pDCs, and the newly described DC subset, DC3. Additionally, we examine critical transcription factors such as IRF8, PU.1, and E2-2 and their regulatory mechanisms and downstream targets. We highlight the complex interplay between these transcription factors, which shape the DC transcriptome and influence their function in response to environmental stimuli. The information presented in this review provides essential insights into the regulation of DC development and function, which might have implications for developing novel therapeutic strategies for immune-related diseases.


Assuntos
Regulação da Expressão Gênica , Transcriptoma , Diferenciação Celular , Células Dendríticas
19.
RSC Adv ; 13(20): 13840-13844, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37152556

RESUMO

The use of electrochemical water is a very attractive and environmentally friendly solution for hydrogen fuel production. Platinum (Pt) catalysts are considered to be the most active catalyst for the hydrogen evolution reaction (HER) but suffer from low efficiency and slow kinetics. Herein, Pt nanoparticles dispersed Ni(OH)2 nanosheets (Pt-Ni(OH)2-X) with different deposition times were designed and developed via a vapour-phase hydrothermal method, followed by a pulsed laser deposition method. The Pt-Ni(OH)2-5 only needs overpotentials of 247.5 ± 43 and 512.5 ± 18 mV to reach current densities of 10 and 100 mA cm-2, respectively, outperforming the commercial Pt/C at a current density of 100 mA cm-2. Furthermore, the infrared spectrum revealed that the adsorption of water molecules becomes stronger at the surface of the Pt-Ni(OH)2-5 nanosheets, and the hydrogen protons overflow onto the Pt surface and facilitate the HER process. This work suggests that moderate Pt nanoparticle dispersed Ni(OH)2 nanosheet help to promote the hydrogen production process.

20.
Chem Sci ; 14(24): 6558-6563, 2023 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-37350822

RESUMO

Catalytic depolymerization represents a promising approach for the closed-loop recycling of plastic wastes. Here, we report a knowledge-driven catalyst development for poly(ethylene terephthalate) (PET) recycling, which not only achieves more than 23-fold enhancement in specific activity but also reduces the alkali concentration by an order of magnitude compared with the conventional hydrolysis. Substituted binuclear zinc catalysts are developed to regulate biomimetic intramolecular PET hydrolysis. Hammett studies and density functional theory (DFT) calculations indicate that the substituents modify the charge densities of the active centers, and an optimal substituent should slightly increase the electron richness of the zinc sites to facilitate the formation of a six-membered ring intermediate. The understanding of the structure-activity relationship leads to an advanced catalyst with a specific activity of 778 ± 40 gPET h-1 gcatal-1 in 0.1 M NaOH, far outcompeting the conventional hydrolysis using caustic bases (<33.3 gPET h-1 gcatal-1 in 1-5 M NaOH). This work opens new avenues for environmentally benign PET recycling.

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