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1.
Zhongguo Zhen Jiu ; 43(2): 239-44, 2023 Feb 12.
Artigo em Chinês | MEDLINE | ID: mdl-36808522

RESUMO

Electroacupuncture may play a role in treatment of learning and memory impairment after ischemic stroke by regulating phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA)/cAMP response element binding protein (CREB) signaling pathway, nerve growth factor (NGF)/tyrosine kinase-A (TrkA) signaling pathway, Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway, Notch signaling pathway, erythropoietin-producing hepatocyte (Eph)/ephrin signaling pathway. The interactions among these pathways should be further explored in treatment of learning and memory impairment after ischemic stroke.


Assuntos
Eletroacupuntura , AVC Isquêmico , Humanos , Aprendizagem , Transdução de Sinais/fisiologia
2.
Adv Mater ; 35(7): e2208846, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36444853

RESUMO

The elaborate design of powerful Li-S binders with extended-functions like polysulfides adsorption/catalysis and Li+ hopping/transferring in addition to robust adhesion-property has remained a challenge. Here, an in situ cathode-interweaving strategy based on metalloporphyrin based covalent-bonding organic polymer (M-COP, M = Mn, Ni, and Zn) binders is reported for the first time. Thus-produced functional binders possess excellent mechanical-strengths, polysulfides adsorption/catalysis, and Li+ hopping/transferring ability. Specifically, the modulus of Mn-COP can reach up to ≈54.60 GPa (≈40 times higher than poly(vinylidene fluoride)) and the relative cell delivers a high initial-capacity (1027 mAh g-1 , 1 C and 913 mAh g-1 , 2 C), and excellent cycling-stability for >1000 cycles even at 4 C. The utilization-rate of sulfur can reach up to 81.8% and the electrodes based on these powerful binders can be easily scale-up fabricated (≈20 cm in a batch-experiment). Noteworthy, Mn-COP based cell delivers excellent capacities at a high sulfur-loading (8.6 mg cm-2 ) and low E/S ratio (5.8 µL mg-1 ). In addition, theoretical calculations reveal the vital roles of metalloporphyrin and thiourea-groups in enhancing the battery-performance.

3.
Angew Chem Int Ed Engl ; 61(50): e202212162, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36229417

RESUMO

Strategy that can design powerful photothermal-catalysts to achieve photothermal-effect assisted coupling-catalysis is much desired for the improvement of energy conversion efficiency and redox product value in CO2 electroreduction system. Herein, a kind of bifunctional viologen-containing covalent organic framework (Ni-2CBpy2+ -COF) has been prepared and successfully applied in photothermal-assisted co-electrolysis of CO2 and methanol. Specifically, the FECO (cathode) and FEHCOOH (anode) for Ni-2CBpy2+ -COF can reach up to ≈100 % at 1.9 V with ≈31.5 % saved overall electricity-consumption when the anodic oxygen evolution reaction (OER) is replaced by methanol oxidation. The superior performance could be attributed to the cyclic diquats in Ni-2CBpy2+ -COF that enhance the photothermal effect (ΔT=49.1 °C) to accelerate faster charge transfer between catalyst and immediate species as well as higher selectivity towards desired products as revealed by DFT calculations and characterizations.

4.
Adv Mater ; 34(44): e2206706, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36088527

RESUMO

Porous heterostructured electrocatalysts with multifunctionality and synergistic effect have much benefit for efficient electrocatalytic CO2 reduction reaction (CO2 RR), yet it still remains a daunting challenge to explore heterostructures based on covalent organic frameworks (COFs) and metal-organic frameworks (MOFs) in this field. Here, a series of honeycomb-like porous crystalline hetero-electrocatalysts (MCH-X, X = 1-4, X stands for the numbered sample obtained from different MOF doses in the synthesis of the MCH) are synthesized, and these are successfully applied in electrocatalytic CO2 RR. The specially designed heterostructures with integrated porous MOF-template and ultrathin COF-coating enable efficient CO2 adsorption/activation and conversion into CH4 . The best of them, MCH-3, shows greatly inhibited H2 evolution, excellent current density (-398.1 mA cm-2 ), and superior FE CH 4 ${\rm{F}}{{\rm{E}}_{{\rm{C}}{{\rm{H}}_4}}}$ (76.7%) to the physical mixture (38.0%), the MOF@COF without the honeycomb-like morphology (47.7%), and the bare COF (37.5%) and MOF (15.9%) at -1.0 V. Based on the density functional theory calculations and various characterizations, the vital roles of the MOF in facilitating CO2 adsorption/activation, stabilizing intermediates, and conquering the energy barrier of rate-determining step are intensively studied.

5.
Angew Chem Int Ed Engl ; 61(37): e202209289, 2022 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-35851736

RESUMO

The selective photo-oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is important due to its substitute-role in polyester-fabrication. Here, a titanium-cluster based metal-covalent organic framework nanosheet has been synthesized through the covalent-coupling between Ti6 -NH2 and benzotrithiophene tricarbaldehyde (BTT). The integration of them endows the nanosheet with a visible-light-adsorption region, effective electron-hole separation-efficiency and suitable photo-oxidation ability. Specifically, its photo-selectivity for HMF-to-FDCA can be >95 % with ≈100 % conversion, which is more than 2, 5, and 10 times higher than MOF-901 (43 %), Ti6 -NH2 (19 %) and under-darkness (9 %), respectively. Notably, an O2 -based mechanism is proposed and the vital roles of Ti6 -NH2 and BTT are verified by DFT calculations. This work might facilitate the exploration of porous-crystalline-catalysts for selective biomass-valorization.


Assuntos
Ácidos Dicarboxílicos , Titânio , Biomassa , Ácidos Dicarboxílicos/química , Furaldeído/química , Furanos/química , Porosidade , Titânio/química
6.
Angew Chem Int Ed Engl ; 61(5): e202114648, 2022 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-34806265

RESUMO

Strategies that enable simultaneous morphology-tuning and electroreduction performance boosting are much desired for the exploration of covalent organic frameworks in efficient CO2 electroreduction. Herein, a kind of functionalizing exfoliation agent has been selected to simultaneously modify and exfoliate bulk COFs into functional nanosheets and investigate their CO2 electroreduction performance. The obtained nanosheets (Cu-Tph-COF-Dct) with large-scale (≈1.0 µm) and ultrathin (≈3.8 nm) morphology enable a superior FECH4 (≈80 %) (almost doubly enhanced than bare COF) with large current-density (-220.0 mA cm-2 ) at -0.9 V. The boosted performance can be ascribed to the immobilized functionalizing exfoliation agent (Dct groups) with integrated amino and triazine groups that strengthen CO2 absorption/activation, stabilize intermediates and enrich the CO concentration around the Cu active sites as revealed by DFT calculations. The point-to-point functionalization strategy for modularly assembling Dct-functionalized COF catalyst for CO2 electroreduction will open up the attractive possibility of developing COFs as efficient CO2 RR electrocatalysts.

7.
Angew Chem Int Ed Engl ; 60(40): 21952-21958, 2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34387026

RESUMO

The exploration of novel systems for the electrochemical CO2 reduction reaction (CO2 RR) for the production of hydrocarbons like CH4 remains a giant challenge. Well-designed electrocatalysts with advantages like proton generation/transferring and intermediate-fixating for efficient CO2 RR are much preferred yet largely unexplored. In this work, a kind of Cu-porphyrin-based large-scale (≈1.5 µm) and ultrathin nanosheet (≈5 nm) has been successfully applied in electrochemical CO2 RR. It exhibits a superior FE CH 4 of 70 % with a high current density (-183.0 mA cm-2 ) at -1.6 V under rarely reported neutral conditions and maintains FE CH 4 >51 % over a wide potential range (-1.5 to -1.7 V) in a flow cell. The high performance can be attributed to the construction of numerous hydrogen-bonding networks through the integration of diaminotriazine with Cu-porphyrin, which is beneficial for proton migration and intermediate stabilization, as supported by DFT calculations. This work paves a new way in exploring hydrogen-bonding-based materials as efficient CO2 RR catalysts.

8.
Sci Bull (Beijing) ; 66(16): 1659-1668, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36654300

RESUMO

The design of selective and efficient covalent organic frameworks (COFs) based electrocatalysts with tunable morphology for efficient CO2 reduction reaction (CO2RR) to CH4 is highly desirable. Here, two kinds of anthraquinone-based COFs (i.e., AAn-COF and OH-AAn-COF) with tunable 1D superstructures (e.g., nanofibers (NF) and hollow tubes (HT)) have been produced via Schiff-base condensation reaction. Interestingly, a rarely reported nanosheet-based self-template mechanism and a nanosheet-crimping mechanism have been demonstrated for the production of COF-based nanofibers and hollow tubes, respectively. Besides, the obtained COF-based superstructures can be post-modified with transition metals for efficient CO2RR. Specifically, AAn-COF-Cu (NF) and OH-AAn-COF-Cu (HT) exhibit superior faradaic-efficiency with CH4 (FECH4) of 77% (-128.1 mA cm-2, -0.9 V) and 61% (-99.5 mA cm-2, -1.0 V) in a flow-cell, respectively. Noteworthy, the achieved FECH4 of AAn-COF-Cu (NF) (77%) the is highest one among reported crystalline COFs. This work provides a general methodology in exploring morphology-controlled COFs for electrocatalytic CO2RR.

9.
Langmuir ; 31(43): 11755-9, 2015 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-26467436

RESUMO

The on-surface reactions of tetrathiafulvalene equipped with four benzaldehyde groups (4ATTF) and ditopic diamine molecules are investigated. 4ATTF tends to form large-scale-ordered rhombus structures when reacted with p-phenylenediamine (PPDA). A longer ditopic diamine molecule, 1,1'-biphenyl-4,4'-diamine dihydrochloride (BPDA), causes the domain size of the regular rhombus structure to decrease and triangular and irregular rhombus structures to appear upon reaction with 4ATTF. However, in the rhombus structures formed by different-length ditopic diamine molecules, the single-layer covalent organic frameworks on the graphite surface preferentially orient in alignment with the underlying HOPG substrate lattice.


Assuntos
Compostos Heterocíclicos/síntese química , Compostos Orgânicos/química , Microscopia de Tunelamento , Propriedades de Superfície
11.
Cell Biochem Biophys ; 65(2): 217-27, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23015227

RESUMO

Despite the advances of adjuvant chemotherapy and significant improvement of survival, the prognosis for patients with osteosarcoma is generally poor. The search for more effective anti-osteosarcoma agents is necessary and urgent. Here we report that perifosine induces cell apoptosis and growth inhibition in cultured human osteosarcoma cells. Perifosine blocks Akt/mTOR complex 1 (mTORC1) signaling, while promoting caspase-3, c-Jun N-terminal kinases (JNK), and p53 activation. Further, perifosine inhibits survivin expression probably by disrupting its association with heat shock protein-90 (HSP-90). These signaling changes together were responsible for a marked increase of osteosarcoma cell apoptosis and growth inhibition. Finally, we found that a low dose of perifosine enhanced etoposide- or doxorubicin-induced anti-OS cells activity. The results together suggest that perifosine might be used as a novel and effective anti-osteosarcoma agent.


Assuntos
Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fosforilcolina/análogos & derivados , Antineoplásicos/farmacologia , Western Blotting , Caspase 3/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Doxorrubicina/farmacologia , Sinergismo Farmacológico , Ensaio de Imunoadsorção Enzimática , Etoposídeo/farmacologia , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina , Complexos Multiproteicos/metabolismo , Osteossarcoma/tratamento farmacológico , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Fosforilcolina/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Proteína Supressora de Tumor p53/metabolismo
12.
Arch Biochem Biophys ; 481(1): 131-6, 2009 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-18940180

RESUMO

Angiotensin II (Ang II) plays an important role in inflammatory process. Acute lung injury (ALI), an inflammatory disorder of the lung, is commonly associated with endotoxemia; however, the mechanism that endotoxin (lipopolysaccharide, LPS) induces the inflammatory response in ALI is not well defined. Here, we showed, in LPS-induced ALI rat model, that Ang II and Ang II type 1 (AT(1)) receptor were significantly increased in lung tissues, compared with those in controls. Meanwhile, nuclear factor (NF)-kappaB-DNA-binding activity, tumor necrosis factor (TNF)-alpha mRNA, and pneumocytic apoptosis were significantly increased. Moreover, pretreatment of rats with losartan, an antagonist of AT(1) receptor for Ang II, improved the inflammation, reduced the elevation of Ang II and AT(1) receptor, and inhibited NF-kappaB-DNA-binding activity, expression of TNF-alpha mRNA, and pneumocytic apoptosis. The data indicate that Ang II may mediate the inflammatory process in LPS-induced ALI through AT(1) receptor, which can be blocked by losartan.


Assuntos
Lesão Pulmonar Aguda/metabolismo , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Angiotensina II/metabolismo , Lipopolissacarídeos/farmacologia , Losartan/farmacologia , Receptor Tipo 1 de Angiotensina/metabolismo , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/patologia , Angiotensina II/sangue , Animais , Apoptose , Pulmão/metabolismo , Pulmão/patologia , NF-kappa B/metabolismo , Ratos , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/metabolismo
13.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue ; 18(6): 327-30, 2006 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-16784555

RESUMO

OBJECTIVE: To compare the measurement of extra-vascular lung water (EVLW) by a single-indicator dilution technique and measurement obtained by gravimetry in different types of acute respiratory distress syndrome (ARDS). METHODS: Thirty-three dogs were randomly assigned to three groups: control group, oleic acid group and hydrochloric acid group. ARDS was reproduced by either intravenous injection of oleic acid or intratracheal instillation of hydrochloric acid. EVLW was measured before ARDS, at the onset of ARDS and 10 hours after ARDS by a single indicator dilution technique. Ten hours after ARDS, dogs were sacrificed and then EVLW was quantitated by a gravimetric measurement (golden standard). Hemodynamics and pulmonary gas exchange were determined. RESULTS: There was a close positive correlation (r=0.8820, P<0.05) between single indicator dilution and gravimetric measurements. However, the measurement with the single indicator dilution was consistently higher than the gravimetric measurement. In the control group, there was a positive correlation (r=0.9870, P<0.05) between the values of EVLW as measured by single indicator dilution and by gravimetric measurements. In the oleic acid group, there was also a significant correlation (r=0.9360, P<0.05) between the values of EVLW as measured by single indicator dilution and by gravimetric measurements. In the hydrochloric acid group, correlation (r=0.7950, P<0.05) was also found between EVLW as measured by the two methods. However, the correlation found was lower in the hydrochloric acid group than those in other two groups. Hydrochloric acid instillation resulted in a significant increase in shunting and the partial pressure of carbon dioxide in artery (PaCO(2)) compared with oleic acid group at 10 hours after ARDS. CONCLUSION: The results of measuring EVLW using single indicator dilution measurement are closely related with those of gravimetric measurement in ARDS, however, the correlations varies with the methods of reproduction of ARDS.


Assuntos
Água Extravascular Pulmonar/metabolismo , Síndrome do Desconforto Respiratório/diagnóstico , Testes de Função Respiratória/métodos , Termodiluição/métodos , Animais , Modelos Animais de Doenças , Cães , Feminino , Ácido Clorídrico/administração & dosagem , Masculino , Ácido Oleico/administração & dosagem , Distribuição Aleatória , Síndrome do Desconforto Respiratório/induzido quimicamente , Síndrome do Desconforto Respiratório/metabolismo , Sensibilidade e Especificidade
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