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1.
Eur Heart J ; 44(14): 1265-1279, 2023 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-36721994

RESUMO

AIMS: Proliferation of vascular smooth muscle cells (VSMCs) is a hallmark of pulmonary hypertension (PH). Proliferative cells utilize purine bases from the de novo purine synthesis (DNPS) pathways for nucleotide synthesis; however, it is unclear whether DNPS plays a critical role in VSMC proliferation during development of PH. The last two steps of DNPS are catalysed by the enzyme 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/inosine monophosphate cyclohydrolase (ATIC). This study investigated whether ATIC-driven DNPS affects the proliferation of pulmonary artery smooth muscle cells (PASMCs) and the development of PH. METHODS AND RESULTS: Metabolites of DNPS in proliferative PASMCs were measured by liquid chromatography-tandem mass spectrometry. ATIC expression was assessed in platelet-derived growth factor-treated PASMCs and in the lungs of PH rodents and patients with pulmonary arterial hypertension. Mice with global and VSMC-specific knockout of Atic were utilized to investigate the role of ATIC in both hypoxia- and lung interleukin-6/hypoxia-induced murine PH. ATIC-mediated DNPS at the mRNA, protein, and enzymatic activity levels were increased in platelet-derived growth factor-treated PASMCs or PASMCs from PH rodents and patients with pulmonary arterial hypertension. In cultured PASMCs, ATIC knockdown decreased DNPS and nucleic acid DNA/RNA synthesis, and reduced cell proliferation. Global or VSMC-specific knockout of Atic attenuated vascular remodelling and inhibited the development and progression of both hypoxia- and lung IL-6/hypoxia-induced PH in mice. CONCLUSION: Targeting ATIC-mediated DNPS compromises the availability of purine nucleotides for incorporation into DNA/RNA, reducing PASMC proliferation and pulmonary vascular remodelling and ameliorating the development and progression of PH.


Assuntos
Hipertensão Pulmonar , Hipertensão Arterial Pulmonar , Camundongos , Animais , Roedores/metabolismo , Remodelação Vascular/fisiologia , Artéria Pulmonar , Purinas/metabolismo , Células Cultivadas , Hipóxia/metabolismo , RNA Mensageiro/metabolismo , Fator de Crescimento Derivado de Plaquetas/metabolismo , Proliferação de Células , Miócitos de Músculo Liso/metabolismo
2.
Am J Respir Cell Mol Biol ; 69(6): 678-688, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37639326

RESUMO

Acute lung injury (ALI) is characterized by lung vascular endothelial cell (EC) barrier compromise resulting in increased endothelial permeability and pulmonary edema. The infection of gram-negative bacteria that produce toxins like LPS is one of the major causes of ALI. LPS activates Toll-like receptor 4, leading to cytoskeleton reorganization, resulting in lung endothelial barrier disruption and pulmonary edema in ALI. However, the signaling pathways that lead to the cytoskeleton reorganization and lung microvascular EC barrier disruption remain largely unexplored. Here we show that LPS induces calpain activation and talin cleavage into head and rod domains and that inhibition of calpain attenuates talin cleavage, RhoA activation, and pulmonary EC barrier disruption in LPS-treated human lung microvascular ECs in vitro and lung EC barrier disruption and pulmonary edema induced by LPS in ALI in vivo. Moreover, overexpression of calpain causes talin cleavage and RhoA activation, myosin light chain (MLC) phosphorylation, and increases in actin stress fiber formation. Furthermore, knockdown of talin attenuates LPS-induced RhoA activation and MLC phosphorylation and increased stress fiber formation and mitigates LPS-induced lung microvascular endothelial barrier disruption. Additionally, overexpression of talin head and rod domains increases RhoA activation, MLC phosphorylation, and stress fiber formation and enhances lung endothelial barrier disruption. Finally, overexpression of cleavage-resistant talin mutant reduces LPS-induced increases in MLC phosphorylation in human lung microvascular ECs and attenuates LPS-induced lung microvascular endothelial barrier disruption. These results provide the first evidence that calpain mediates LPS-induced lung microvascular endothelial barrier disruption in ALI via cleavage of talin.


Assuntos
Lesão Pulmonar Aguda , Edema Pulmonar , Humanos , Lipopolissacarídeos/farmacologia , Calpaína/metabolismo , Talina/metabolismo , Pulmão/metabolismo , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/metabolismo , Cadeias Leves de Miosina/metabolismo , Permeabilidade Capilar
3.
Small ; 19(11): e2206338, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36539266

RESUMO

Flexible aqueous zinc batteries are promising candidates as safe power sources for fast-growing portable and wearable electronics. However, the low working voltage, poor rate capability, and cycling stability have greatly restricted their development and applications. Here, a new family of flexible bimetallic phosphide/carbon nanotube hybrid fiber electrodes with unique macroscopic microcrack structure and microscopic porous nanoflower structure is reported. The hierarchical microcrack structure not only facilitates the penetration of electrolyte for effective exposure of active sites, but also can serve as buffers to relieve the stress concentrations of the fiber electrode under deformations, enabling impressive electrochemical performance and mechanical flexibility. Particularly, the fabricated flexible aqueous zinc batteries demonstrate high working voltage plateau and specific capacity (≈1.7 V, 258.9 mAh g-1 at 2 A g-1 ), ultrahigh rate capability (135.8 mAh g-1 at 50 A g-1 , fully charged in only 9.8 s) and impressive power density of 79 000 W kg-1 . Moreover, the flexible batteries show ultralong cycling life with 74.6% capacity retention after 20 000 cycles. The fiber batteries are also highly flexible and can be easily knitted into soft electronic textiles to power a smartphone, which are particularly promising for the next-generation of flexible and wearable electronics.

4.
Phys Chem Chem Phys ; 25(40): 27829-27835, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37814900

RESUMO

Herein, a new series of bowl-shaped quadridentate ligands with a Si-N-Si-C-Si-C six-membered ring core and their manganese catalysts were designed using the density functional theory (DFT) method for the hydrogenation of unsaturated CX (XN, O) bonds. The frameworks of these ligands named by LYG (LYG = P(R1)2CH2Si(CH2)(CH3)NSi(CH3)(CH2Si(CH3)CH2P(R3)2)CH2P(R2)2) have a Si-N-Si-C-Si-C six-membered ring core at the bottom of the bowl structure and each Si atom links with one phosphorus arm (-CH2PR2). The Mn catalyst Mn(CO)-LYG was constructed to catalyze the hydrogenation of CO/CN bonds. The calculated results indicate that due to the bowl-shaped structure of LYG quadridentate ligands, these Mn catalysts could be advantageous not only in the tuneup of catalytic activity and stereoselectivity by modifying three phosphorus arms but also in the homogeneous catalyst immobilization by linking with the Si-N-Si-C-Si-C six-membered ring core using different supports. This work might provide theoretical insights to design new framework transition-metal catalysts for the hydrogenation of CX bonds.

5.
Brain Behav Immun ; 90: 55-69, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32739363

RESUMO

Alzheimer's disease (AD) is a progressively neurodegenerative disease with typical hallmarks of amyloid ß (Aß) plaque accumulation, neurofibrillary tangle (NFT) formation and neuronal death extension. In AD brain, activated microglia phagocytose Aß and neuronal debris, but also aggravate inflammation stress by releasing inflammatory factors and cytotoxins. Improving microglia on Aß catabolism and neuroinflammatory intervention is thus believed to be a promising therapeutic strategy for AD. AMP-activated protein kinase (AMPK) is highly expressed in microglia with AMPKα1 being tightly implicated in neuroinflammatory events. Since indirect AMPKα1 activators may cause side effects with undesired intracellular AMP/ATP ratio, we focused on direct AMPKα1 activator study by exploring its potential function in ameliorating AD-like pathology of AD model mice. Here, we reported that direct AMPKα1 activator DW14006 (2-(3-(7-chloro-6-(2'-hydroxy-[1,1'-biphenyl]-4-yl)-2-oxo-1,2-dihydroquinolin-3-yl)phenyl)acetic acid) effectively improved learning and memory impairments of APP/PS1 mice, and the underlying mechanisms have been intensively investigated. DW14006 reduced amyloid plaque deposition by promoting microglial o-Aß42 phagocytosis and ameliorated innate immune response by polarizing microglia to an anti-inflammatory phenotype. It selectively enhanced microglial phagocytosis of o-Aß42 by upgrading scavenger receptor CD36 through AMPKα1/PPARγ/CD36 signaling and suppressed inflammation by AMPKα1/IκB/NFκB signaling. Together, our work has detailed the crosstalk between AMPKα1 and microglia in AD model mice, and highlighted the potential of DW14006 in the treatment of AD.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos , Microglia/metabolismo , Fagocitose
6.
Biochem Biophys Res Commun ; 499(4): 948-953, 2018 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-29626480

RESUMO

Activating transcription factor 6α (ATF6α) as a transducer in unfolded protein response (UPR), plays an important role in liver glucose metabolism and insulin resistance. Thus, targeting ATF6α activation has been proposed to be a potential strategy for anti-T2DM drug discovery. Here, we determined that small molecule 2-[5-[1-(4-chlorophenoxy)ethyl]-4-phenyl-4H-1,2,4-triazol-3-yl]sulfanyl-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide (TSPA) functioned as an ATF6α translocation inducer effectively promoting ATF6α translocation into nucleus and ameliorating glucose homeostasis on db/db mice. TSPA promoted ATF6α translocation into nucleus without incresing C/EBP-homologous protein (CHOP) expression. TSPA restored the tunicamycin (TM)-stimulated insulin receptor (IR) desensitization through ATF6α activation, inhibited gluconeogenesis and efficiently improved glucose homeostasis on db/db mice. Furthermore, TSPA protected insulin pathway involving p38/X-box binding protein 1s (Xbp1s)/ER chaperones signaling pathway. Our current study has determined that ATF6α was a promising therapeutic target and also highlighted the potential of TSPA in the treatment of type 2 diabetes mellitus (T2DM).


Assuntos
Acetamidas/farmacologia , Fator 6 Ativador da Transcrição/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Glucose/metabolismo , Homeostase , Resistência à Insulina , Pirazóis/farmacologia , Triazóis/farmacologia , Animais , Linhagem Celular Tumoral , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Humanos , Masculino , Camundongos , Transporte Proteico/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição CHOP/metabolismo , Tunicamicina/farmacologia , Proteína 1 de Ligação a X-Box/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
7.
Acta Pharmacol Sin ; 38(8): 1104-1119, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28649128

RESUMO

Alzheimer's disease (AD) is a progressive neurodegenerative disease leading to the irreversible loss of brain neurons and cognitive abilities, and the vicious interplay between oxidative stress (OS) and tauopathy is believed to be one of the major players in AD development. Here, we demonstrated the capability of the small molecule N-(1,3-benzodioxol-5-yl)-2-[5-chloro-2-methoxy(phenylsulfonyl)anilino]acetamide (LX2343) to ameliorate the cognitive dysfunction of AD model rats by inhibiting OS-induced neuronal apoptosis and tauopathy. Streptozotocin (STZ) was used to induce OS in neuronal cells in vitro and in AD model rats that were made by intracerebroventricular injection of STZ (3 mg/kg, bilaterally), and Morris water maze test was used to evaluate the cognitive dysfunction in ICV-STZ rats. Treatment with LX2343 (5-20 µmol/L) significantly attenuated STZ-induced apoptosis in SH-SY5Y cells and mouse primary cortical neurons by alleviating OS and inhibiting the JNK/p38 and pro-apoptotic pathways. LX2343 was able to restore the integrity of mitochondrial function and morphology, increase ATP biosynthesis, and reduce ROS accumulation in the neuronal cells. In addition, LX2343 was found to be a non-ATP competitive GSK-3ß inhibitor with IC50 of 1.84±0.07 µmol/L, and it potently inhibited tau hyperphosphorylation in the neuronal cells. In ICV-STZ rats, administration of LX2343 (7, 21 mg·kg-1·d-1, ip, for 5 weeks) efficiently improved their cognitive deficits. LX2343 ameliorates the cognitive dysfunction in the AD model rats by suppressing OS-induced neuronal apoptosis and tauopathy, thus highlighting the potential of LX2343 for the treatment of AD.


Assuntos
Acetamidas/uso terapêutico , Doença de Alzheimer/tratamento farmacológico , Apoptose/efeitos dos fármacos , Disfunção Cognitiva/tratamento farmacológico , Nootrópicos/uso terapêutico , Estresse Oxidativo/efeitos dos fármacos , Sulfonamidas/uso terapêutico , Tauopatias/tratamento farmacológico , Animais , Células Cultivadas , Modelos Animais de Doenças , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
8.
Acta Pharmacol Sin ; 38(1): 9-28, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27694908

RESUMO

Considering the complicated pathogenesis of Alzheimer's disease (AD), multi-targets have become a focus in the discovery of drugs for treatment of this disease. In the current work, we established a multi-target strategy for discovering active reagents capable of suppressing both Aß level and Tau hyperphosphorylation from natural products, and found that the ethanol extract of Thamnolia vermicularis (THA) was able to improve learning ability in APP/PS1 transgenic mice by inhibiting both Aß levels and Tau hyperphosphorylation. SH-SY5Y and CHO-APP/BACE1 cells and primary astrocytes were used in cell-based assays. APP/PS1 transgenic mice [B6C3-Tg(APPswe, PS1dE9)] were administered THA (300 mg·kg-1·d-1, ig) for 100 d. After the administration was completed, the learning ability of the mice was detected using a Morris water maze (MWM) assay; immunofluorescence staining, Congo red staining and Thioflavine S staining were used to detect the senile plaques in the brains of the mice. ELISA was used to evaluate Aß and sAPPß contents, and Western blotting and RT-PCR were used to investigate the relevant signaling pathway regulation in response to THA treatment. In SH-SY5Y cells, THΑ (1, 10, 20 µg/mL) significantly stimulated PI3K/AKT/mTOR and AMPK/raptor/mTOR signaling-mediated autophagy in the promotion of Aß clearance as both a PI3K inhibitor and an AMPK indirect activator, and restrained Aß production as a suppressor against PERK/eIF2α-mediated BACE1 expression. Additionally, THA functioned as a GSK3ß inhibitor with an IC50 of 1.32±0.85 µg/mL, repressing Tau hyperphosphorylation. Similar effects on Aß accumulation and Tau hyperphosphorylation were observed in APP/PS1 transgenic mice treated with THA. Furthermore, administration of THA effectively improved the learning ability of APP/PS1 transgenic mice, and markedly reduced the number of senile plaques in their hippocampus and cortex. The results highlight the potential of the natural product THA for the treatment of AD.


Assuntos
Precursor de Proteína beta-Amiloide/genética , Líquens/química , Aprendizagem em Labirinto/efeitos dos fármacos , Extratos Vegetais/farmacologia , Placa Amiloide/metabolismo , Presenilina-1/genética , Tauopatias/tratamento farmacológico , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Encéfalo/metabolismo , Células Cultivadas , Cricetinae , Relação Dose-Resposta a Droga , Camundongos Transgênicos , Fosforilação/efeitos dos fármacos , Extratos Vegetais/química , Cultura Primária de Células , Transdução de Sinais/efeitos dos fármacos , Proteínas tau/metabolismo
9.
Phys Chem Chem Phys ; 16(22): 11037-46, 2014 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-24779028

RESUMO

The effects of chemical and structural surface heterogeneity on the CH4 adsorption behaviour on microporous carbons have been investigated using a hybrid theoretical approach, including the use of density functional theory (DFT), molecular dynamics (MD), and grand canonical Monte Carlo (GCMC) simulations. Bader charge analysis is first performed to analyze the surface atomic partial charges. The CH4 adsorption densities in defective and functionalized graphite slit pores are lower than that in the perfect pore according to the MD simulations. Finally, the CH4 adsorption isotherms for the perfect, defective and functionalized slit pores are analyzed using the GCMC simulations in combination with the DFT and MD results. For pores with a defective surface, the adsorption capacities decrease; the embedded functional groups decrease the adsorption capacity at low pressure and enhance it at high pressure. Our results demonstrate the significant effects of chemical and structural surface heterogeneity on the CH4 adsorption and provide a systematic approach to understand the gas adsorption behaviour.

10.
Heliyon ; 10(11): e32049, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38947445

RESUMO

Since the 20th century, Red Culture has served as a significant informal institution guiding revolutionary trajectory and developmental course. However, integrating Red Culture into contemporary corporate management and leveraging its constructive influence within today's market-driven economy necessitates comprehensive exploration and thoughtful consideration. This study aims to explore the potential influence of Red Culture on contemporary innovation. Empirical findings reveal substantial and affirmative effects of Red Culture on corporate innovation. Specifically, a heightened Red Culture ambiance correlates with a marked increase in both innovation input and output within corporate. Further investigation underscores Red Culture's pivotal governance role in mitigating strategic manipulation of innovation and research and development practices, especially within the overarching framework of innovation-driven strategies. Moreover, Red Culture synergizes with formal innovation incentive mechanisms, jointly fostering corporate innovation. This study provides micro-level empirical evidence that elucidates the impact of Red Culture on corporate innovation. Additionally, it furnishes valuable policy insights for the practical implementation and enhancement of pertinent Red Culture initiative.

11.
Vascul Pharmacol ; 154: 107269, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38158001

RESUMO

CRISPR editing involves double-strand breaks in DNA with attending insertions/deletions (indels) that may result in embryonic lethality in mice. The prime editing (PE) platform uses a prime editing guide RNA (pegRNA) and a Cas9 nickase fused to a modified reverse transcriptase to precisely introduce nucleotide substitutions or small indels without the unintended editing associated with DNA double-strand breaks. Recently, engineered pegRNAs (epegRNAs), with a 3'-extension that shields the primer-binding site of the pegRNA from nucleolytic attack, demonstrated superior activity over conventional pegRNAs in cultured cells. Here, we show the inability of three-component CRISPR or conventional PE to incorporate a nonsynonymous substitution in the Capn2 gene, expected to disrupt a phosphorylation site (S50A) in CAPN2. In contrast, an epegRNA with the same protospacer correctly installed the desired edit in two founder mice, as evidenced by robust genotyping assays for the detection of subtle nucleotide substitutions. Long-read sequencing demonstrated sequence fidelity around the edited site as well as top-ranked distal off-target sites. Western blotting and histological analysis of lipopolysaccharide-treated lung tissue revealed a decrease in phosphorylation of CAPN2 and notable alleviation of inflammation, respectively. These results demonstrate the first successful use of an epegRNA for germline transmission in an animal model and provide a solution to targeting essential developmental genes that otherwise may be challenging to edit.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Camundongos , Animais , Edição de Genes/métodos , RNA Guia de Sistemas CRISPR-Cas , DNA/genética , Nucleotídeos
12.
Reprod Toxicol ; 125: 108554, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38331007

RESUMO

Cadmium (Cd) is a harmful environmental pollutant that disrupts public health, including respiratory, digestive, and reproductive systems. In this study, male rats were exposed to CdCl2 at a dose of 3 mg/kg by oral for 28 days to investigate the impact on spermatogenesis. Testis tissue samples were collected after sacrifice, and piRNA expression levels were measured using piRNA microarray and qPCR. PiRNAs, specialized molecules involved in spermatogenesis, were examined. CdCl2 exposure led to disrupted piRNA expression, particularly in piRNA-DQ759395 in rats. This piRNA was found to have a binding site with p53, and a similar piRNA-DQ717867 was discovered in mice. In GC-2spd cells, CdCl2 exposure increased piRNA-DQ717867 expression, which resulted in cell cycle arrest and abnormal expression of cell cycle-related proteins. The activation of p53-related pathways and disruptions in cell cycle regulation were also observed. Antagomir-717867 transfections and PFT-a pretreatment in GC-2spd cells supported the involvement of piRNA-DQ717867 in regulating cell cycle-related proteins. This study suggests that Cd exposure induces abnormal expression of piRNA-DQ759395 in rat testis and that piRNA-DQ717867 may regulate p53, causing cell cycle abnormalities in GC-2spd cells. These findings help understand the mechanisms of male reproductive toxicity caused by Cd exposure and emphasize the role of piRNAs in cell cycle regulation and male reproductive health.


Assuntos
Cádmio , RNA de Interação com Piwi , Masculino , Ratos , Camundongos , Animais , Cádmio/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Espermatogênese , Testículo/metabolismo
13.
Eur J Med Chem ; 247: 115053, 2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36587419

RESUMO

Herein 2-cyanoethoxy-N,N,N',N'-tetraisopropyl-phosphorodiamidite(10, PIII, 3.5 eq.) could synergistically react with 3',5'-dihydroxyl groups in a dinucleotide(PV) at the cyclization step for the synthesis of cyclic dinucleotides (CDNs) (c-di-GMP, cGAMP etc.) and their phosphorothioated analogues. A dynamic PIII-PV coordination mechanism has been proposed for the cyclization procedure which is confirmed by the variant 31P NMR data and molecular simulation. Among the mono-phosphorothioated CDNs, two stereoisomers showed different capacity for STING activation and the reason was predicted by molecular modeling. While compound 12b1 showed most potent ability to elicit cytokines (IFNß, IL-6, Cxcl9 and Cxcl10) induction compared to another stereoisomer. Also, 12b1 significantly inhibited the tumor growth in the EO771 model with both 0.1 µg (i.t.) and 2 µg (i.v.) administration through the aid of a Mix delivery system developed by our group, and achieved a 31% long-term survival rate of tumor-bearing mice. 12b1/Mix significantly improved the percentage of CD8+ or CD4+ effector memory T (Tem, CD44highCD62Llow) cells and CD8+ central memory T (Tcm, CD44highCD62Lhigh) cells in the blood of EO771 mice, inducing the immune memory against EO771 tumor cells. Relatively lower dose regimens of 12b1(0.1 µg)/Mix displayed better tumor suppression by more potent STING pathway activation and higher levels of cytokines induction in the tumor.


Assuntos
Citocinas , Neoplasias , Animais , Camundongos , Lipídeos , Nucleotídeos de Citosina/química , Nucleotídeos de Citosina/metabolismo
14.
Dalton Trans ; 51(26): 10020-10028, 2022 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-35703402

RESUMO

Herein, a density functional theory (DFT) study was performed to investigate thoroughly the cascade reaction mechanism for the hydrogenation of carbon dioxide to methanol catalyzed by ruthenium pincer complex [RuH2(Me2PCH2SiMe2)2NH(CO)]. Three catalytic stages involving the hydrogenation of carbon dioxide (stage I), formic acid (stage II) and formaldehyde (stage III) were studied. The calculated results show that the dominant H2 activation strategy in the hydrogenation of CO2 to methanol may not be the methanol-assisted H2 activation, but the formate-assisted H2 activation. In this cascade reaction, all energy spans of stage I, II and III are 20.2 kcal mol-1 of the formate-assisted H2 activation. This implies that it could occur under mild conditions. Meanwhile, the catalyst is proposed to be efficient for the transfer hydrogenation using isopropanol as the hydrogen resource, and the ruthenium pincer complexes [RuH2(Me2PCH2SiMe2)2NH(CO)], [RuH2(Ph2PCH2SiMe2)2NH(CO)] and [RuH2(Me2PCH2SiMe2)2NH(CO)] exhibit similar catalytic activities for the hydrogenation of CO2 to methanol.

15.
Am J Transl Res ; 14(10): 6828-6845, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36398259

RESUMO

To reduce pain after total hip replacement (THR), researchers are interested in drug-free interventions. However, there is still a lack of consensus on their prevention efficacy. We performed a meta-analysis to evaluate the use of nonpharmaceutical interventions for postoperative pain management after THR. We searched the Cochrane Library, MEDLINE, EMBASE, Web of Science, PEDRO, and ClinicalTrials.gov databases for articles published between and 1991 and 2020. The main outcome measures were postoperative pain, opioid consumption, and quality of life (QoL). In total, 1,942 patients were studied. We found moderate evidence indicating postoperative pain relief measured by the Western Ontario and McMaster Universities Arthritis Index Scale, with mean differences (MDs) of -0.28 (95% confidence interval [CI], -0.49 to -0.07; P=0.01; I2 =0%) within three months, -0.19 (95% CI, -0.40 to 0.02; P=0.07; I2 =0%) between 3-6 months, and -0.13 (95% CI, -0.35 to 0.08; P=0.21; I2 =0%) between 6-12 months. Additionally, we found that acupuncture therapy could reduce opioid analgesic consumption (MD, -0.98; 95% CI, -1.18 to -0.79; fentanyl [mg/h]; P<0.01; I2 =72.2%) and significantly improve pain relief with an MD of 0.90 (95% CI, 0.47 to 1.33; P<0.01; I2 =0%) measured using the visual analog scale. Electrotherapy slightly improved perceived pain with an MD of 0.22 (95% CI, -0.27 to 0.70; P=0.37; I2 =0%). Moreover, moderate evidence has shown that preoperative exercises improve QoL. This meta-analysis suggested that continuous passive motion did not improve pain or QoL. Postoperative exercise was associated with pain relief and improved QoL. Acupuncture therapy after THR has been shown to reduce opioid analgesic consumption.

16.
RSC Adv ; 11(60): 38120-38125, 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-35498108

RESUMO

To suppress the aggregation behavior caused by the high surface energy of quantum dots (QDs), ZnCdS QDs were grown in situ on a g-C3N4 support. During the growth process, the QDs tightly adhered to the support surface. The ZnCdS QDs were prepared by low-temperature sulfurization and cation exchange with a zeolitic imidazolate framework precursor under mild conditions. The heterojunction of g-C3N4/ZnCdS-2 (CN/ZCS-2, with a g-C3N4 to ZIF-8 ratio of 2.0) not only showed excellent optical absorption performance, abundant reactive sites, and a close contact interface but also effectively separated the photogenerated electrons and holes, which greatly improved its photocatalytic hydrogen production performance. Under visible light irradiation (wavelength > 420 nm) without a noble metal cocatalyst, the hydrogen evolution rate of the CN/ZCS-2 heterojunction reached 1467.23 µmol g-1 h-1, and the durability and chemical stability were extraordinarily high.

17.
Dalton Trans ; 50(48): 17953-17959, 2021 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-34851331

RESUMO

Sluggish charge transfer is the major problem which restricts the development of metal-organic framework (MOF)-based photocatalysts. Recently, facet-engineering has been proven to be an effective method for solving this issue. However, due to difficulties in regulating the exposed facets of MOFs, there are few reports about the facet-engineering of MOF-based photocatalysts. Here, we firstly report facet-engineering for promoting the photocatalytic activity of NH2-UiO-66 crystals. In this study, by regulating the influence of kinetics and thermodynamics, cubic, tetra-decahedral, and octahedral forms of NH2-UiO-66 are synthesized. The photocatalytic hydrogen evolution rate of tetra-decahedral NH2-UiO-66 with co-exposed (100) and (111) crystal facets reaches 64.06 µmol g-1 h-1, which is approximately 2 and 1.5 times greater than that of the cubic and octahedral forms of NH2-UiO-66, respectively. The density functional theory (DFT) calculation and ultrafast spectroscopy results indicate that a slight staggering exists in the band structure of (100) and (111) facets, causing the facets junction to appear. The facet junction promotes the charge separation efficiency and prolongs the lifetime of the charge carriers, thereby giving tetra-decahedral NH2-UiO-66 optimal photocatalytic performance. This study demonstrates the feasibility and potential of facet-engineering for photocatalytic applications of MOFs.

18.
Dalton Trans ; 50(18): 6064-6070, 2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-33885684

RESUMO

ZCS-C (ZnCdS/CdS) QDs were synthesized via low-temperature vulcanization using zeolitic imidazolate framework-8 (ZIF-8) nanoparticles as a precursor, cation exchange, and heterojunction construction. Without any precious metal as a cocatalyst, the photocatalytic hydrogen production rate of ZCS-C-3 QDs reached 2.7 mmol g-1 h-1 under visible light irradiation. The optimized sample exhibited an outstanding chemical stability and recyclability, which is superior to most of the reported Zn1-xCdxS-based photocatalysts.

19.
Curr Med Sci ; 40(3): 444-454, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32681249

RESUMO

Pulmonary hypertension (PH) is a severe and progressive disease characterized by increased pulmonary vascular resistance leading to right heart failure and death. In PH, the cellular metabolisms including those of the three major nutrients (carbohydrate, lipid and protein) are aberrant in pulmonary vascular cells. Glucose uptake, glycolysis, insulin resistance, sphingolipid S1P, PGE2, TXA2, leukotrienes and glutaminolysis are upregulated, and phospholipid-prostacyclin and L-arginine-nitric oxide pathway are compromised in lung vascular cells. Fatty acid metabolism is disordered in lung endothelial cells and smooth muscle cells. These molecular mechanisms are integrated to promote PH-specific abnormal vascular cell proliferation and vascular remodeling. This review summarizes the recent advances in the metabolic reprogramming of glucose, fatty acid, and amino acid metabolism in pulmonary vascular remodeling in PH and the mechanisms for how these alterations affect vascular cell fate and impact the course of PH.


Assuntos
Hipertensão Pulmonar/metabolismo , Remodelação Vascular/fisiologia , Animais , Proliferação de Células/fisiologia , Células Endoteliais/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Pulmão/metabolismo , Miócitos de Músculo Liso/metabolismo , Transdução de Sinais/fisiologia
20.
Sci Total Environ ; 726: 138564, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32315854

RESUMO

Polystyrene (PS) has been widely used in various fields, whereas this thermoplastic material is generally considered to be resistant to biodegradation. Tribolium castaneum (Coleoptera: Tenebrionidae), a common pest of stored agricultural products, is a powerful model organism for general insect research. In this study, the larvae of T. castaneum were observed chewing and eating extruded polystyrene foam (XPS). Investigation of the gut microbiome of plastic- and bran-fed T. castaneum larvae showed that Acinetobacter sp. was strongly associated with PS ingestion. Additionally, one bacterial strain capable of PS degradation, was successfully isolated from the gut of these larvae and identified as Acinetobacter sp. AnTc-1 by its 16S rDNA sequence. Gel penetration chromatography (GPC), 1H nuclear magnetic resonance (1H NMR) spectroscopy, thermo gravimetric analysis (TGA) and scanning electron microscope (SEM) were employed to characterize the PS degradation. After incubation with AnTc-1 for 60 days, the mass weight (12.14%) and molecular weight (13%/25%, weight-average molecular weight (Mw)/number-average molecular weight (Mn)) of PS powder were significantly reduced. The results indicated that the isolated strain of Acinetobacter sp. AnTc-1 has PS-degrading capacity. The isolated strain may play a role in the larval gut for biodegradation of PS and has potential to be applied for petroleum-based plastic degradation study and development of remediation approaches.


Assuntos
Acinetobacter , Besouros , Tribolium , Animais , Larva , Poliestirenos
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