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1.
Exp Ther Med ; 28(1): 275, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38800049

RESUMO

Particulate matter 2.5 (PM2.5) imposes a heavy burden on the skin and respiratory system of human beings, causing side effects such as aging, inflammation and cancer. Astaxanthin (ATX) is a well-known antioxidant widely used for its anti-inflammatory and anti-aging properties. However, few studies have investigated the protective effects of ATX against PM2.5-induced senescence in HaCaT cells. In the present study, the levels of reactive oxygen species (ROS) and antioxidant enzymes were measured after treatment with PM2.5. The results revealed that PM2.5 generated excessive ROS and reduced the translocation of nuclear factor erythroid 2-related factor 2 (NRF2), subsequently reducing the expression of antioxidant enzymes. However, pretreatment with ATX reversed the ROS levels as well as the expression of antioxidant enzymes. In addition, ATX protected cells from PM2.5-induced DNA damage and rescued PM2.5-induced cell cycle arrest. The levels of senescence-associated phenotype markers, such as interleukin-1ß, matrix metalloproteinases, and ß-galactosidase, were increased by exposure to PM2.5, however these effects were reversed by ATX. After interfering with NRF2 mRNA expression and exposing cells to PM2.5, the levels of ROS and ß-galactosidase were higher compared with siControl RNA cells exposed to PM2.5. However, ATX inhibited ROS and ß-galactosidase levels in both the siControl RNA and the siNRF2 RNA groups. Thus, ATX protects HaCaT keratinocytes from PM2.5-induced senescence by partially inhibiting excessive ROS generation via the NRF2 signaling pathway.

2.
Toxicol Mech Methods ; : 1-10, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38736318

RESUMO

This study investigated the mechanism of silver nanoparticle (AgNP) cytotoxicity from a mitochondrial perspective. The effect of AgNP on manganese superoxide dismutase (MnSOD), a mitochondrial antioxidant enzyme, against oxidative stress has not been studied in detail. We demonstrated that AgNP decreased MnSOD mRNA level, protein expression, and activity in human Chang liver cells in a time-dependent manner. AgNP induced the production of mitochondrial reactive oxygen species (mtROS), particularly superoxide anion. AgNP was found to increase mitochondrial calcium level and disrupt mitochondrial function, leading to reduced ATP level, succinate dehydrogenase activity, and mitochondrial permeability. AgNP induced cytochrome c release from the mitochondria into the cytoplasm, attenuated the expression of the anti-apoptotic proteins phospho Bcl-2 and Mcl-1, and induced the expression of the pro-apoptotic proteins Bim and Bax. In addition, c-Jun N-terminal kinase (JNK) phosphorylation was significantly increased by AgNP. Treatment with elamipretide (a mitochondria-targeted antioxidant) and SP600125 (a JNK inhibitor) showed the involvement of MnSOD and JNK in these processes. These results indicated that AgNP damaged human Chang liver cells by destroying mitochondrial function through the accumulation of mtROS.

3.
Mol Med Rep ; 30(1)2024 07.
Artigo em Inglês | MEDLINE | ID: mdl-38757300

RESUMO

Physiological stress such as excessive reactive oxygen species (ROS) production may contribute normal fibroblasts activation into cancer­associated fibroblasts, which serve a crucial role in certain types of cancer such as pancreatic, breast, liver and lung cancer. The present study aimed to examine the cytoprotective effects of luteolin (3',4',5,7­tetrahydroxyflavone) against hydrogen peroxide (H2O2)­generated oxidative stress in lung fibroblasts. To examine the effects of luteolin against H2O2­induced damages, cell viability, sub­G1 cell population, nuclear staining with Hoechst 33342, lipid peroxidation and comet assays were performed. To evaluate the effects of luteolin on the protein expression level of apoptosis, western blot assay was performed. To assess the antioxidant effects of luteolin, detection of ROS using H2DCFDA staining, O2­ and ·OH using electron spin resonance spectrometer and antioxidant enzyme activity was performed. In a cell­free chemical system, luteolin scavenges superoxide anion and hydroxyl radical generated by xanthine/xanthine oxidase and the Fenton reaction (FeSO4/H2O2). Furthermore, Chinese hamster lung fibroblasts (V79­4) treated with H2O2 showed a significant increase in cellular ROS. Intracellular ROS levels and damage to cellular components such as lipids and DNA in H2O2­treated cells were significantly decreased by luteolin pretreatment. Luteolin increased cell viability, which was impaired following H2O2 treatment and prevented H2O2­mediated apoptosis. Luteolin suppressed active caspase­9 and caspase­3 levels while increasing Bcl­2 expression and decreasing Bax protein levels. Additionally, luteolin restored levels of glutathione that was reduced in response to H2O2. Moreover, luteolin enhanced the activity and protein expressions of superoxide dismutase, catalase, glutathione peroxidase, and heme oxygenase­1. Overall, these results indicated that luteolin inhibits H2O2­mediated cellular damage by upregulating antioxidant enzymes.


Assuntos
Antioxidantes , Apoptose , Sobrevivência Celular , Fibroblastos , Peróxido de Hidrogênio , Luteolina , Estresse Oxidativo , Espécies Reativas de Oxigênio , Luteolina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Peróxido de Hidrogênio/farmacologia , Peróxido de Hidrogênio/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/efeitos dos fármacos , Linhagem Celular , Cricetinae , Peroxidação de Lipídeos/efeitos dos fármacos , Cricetulus
4.
Mol Cells ; 47(5): 100066, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38679413

RESUMO

Particulate matter 2.5 (PM2.5) poses a serious threat to human health and is responsible for respiratory disorders, cardiovascular diseases, and skin disorders. 3-Bromo-4,5-dihydroxybenzaldehyde (3-BDB), abundant in marine red algae, exhibits anti-inflammatory, antioxidant, and antidiabetic activities. In this study, we investigated the protective mechanisms of 3-BDB against PM2.5-induced cell cycle arrest and autophagy in human keratinocytes. Intracellular reactive oxygen species generation, DNA damage, cell cycle arrest, intracellular Ca2+ level, and autophagy activation were tested. 3-BDB was found to restore cell proliferation and viability which were reduced by PM2.5. Furthermore, 3-BDB reduced PM2.5-induced reactive oxygen species levels, DNA damage, and attenuated cell cycle arrest. Moreover, 3-BDB ameliorated the PM2.5-induced increases in cellular Ca2+ level and autophagy activation. While PM2.5 treatment reduced cell growth and viability, these were restored by the treatment with the autophagy inhibitor bafilomycin A1 or 3-BDB. The findings indicate that 3-BDB ameliorates skin cell death caused by PM2.5 via inhibiting cell cycle arrest and autophagy. Hence, 3-BDB can be exploited as a preventive/therapeutic agent for PM2.5-induced skin impairment.


Assuntos
Autofagia , Benzaldeídos , Pontos de Checagem do Ciclo Celular , Queratinócitos , Material Particulado , Espécies Reativas de Oxigênio , Autofagia/efeitos dos fármacos , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Material Particulado/toxicidade , Benzaldeídos/farmacologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Proliferação de Células/efeitos dos fármacos , Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos
5.
Int J Med Sci ; 21(5): 937-948, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38617009

RESUMO

The skin is directly exposed to atmospheric pollutants, especially particulate matter 2.5 (PM2.5) in the air, which poses significant harm to skin health. However, limited research has been performed to identify molecules that can confer resistance to such substances. Herein, we analyzed the effect of fermented sea tangle (FST) extract on PM2.5-induced human HaCaT keratinocyte damage. Results showed that FST extract, at concentrations less than 800 µg/mL, exhibited non-significant toxicity to cells and concentration-dependent inhibition of PM2.5-induced reactive oxygen species (ROS) production. PM2.5 induced oxidative stress by stimulating ROS, resulting in DNA damage, lipid peroxidation, and protein carbonylation, which were inhibited by the FST extract. FST extract significantly suppressed the increase in calcium level and apoptosis caused by PM2.5 treatment and significantly restored the reduced cell viability. Mitochondrial membrane depolarization occurred due to PM2.5 treatment, however, FST extract recovered mitochondrial membrane polarization. PM2.5 inhibited the expression of the anti-apoptotic protein Bcl-2, and induced the expression of pro-apoptotic proteins Bax and Bim, the apoptosis initiator caspase-9, as well as the executor caspase-3, however, FST extract effectively protected the changes in the levels of these proteins caused by PM2.5. Interestingly, pan-caspase inhibitor Z-VAD-FMK treatment enhanced the anti-apoptotic effect of FST extract in PM2.5-treated cells. Our results indicate that FST extract prevents PM2.5-induced cell damage via inhibition of mitochondria-mediated apoptosis in human keratinocytes. Accordingly, FST extract could be included in skin care products to protect cells against the harmful effects of PM2.5.


Assuntos
Queratinócitos , Pele , Humanos , Espécies Reativas de Oxigênio , Apoptose , Material Particulado/toxicidade
6.
Artif Organs ; 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38660762

RESUMO

BACKGROUND: Vascular smooth muscle cells (VSMCs) are commonly used as seed cells in tissue-engineered vascular constructions. However, their variable phenotypes and difficult to control functions pose challenges. This study aimed to overcome these obstacles using a three-dimensional culture system. METHODS: Calf VSMCs were administered tumor necrosis factor-alpha (TNF-α) before culturing in two- and three-dimensional well plates and polyglycolic acid (PGA) scaffolds, respectively. The phenotypic markers of VSMCs were detected by immunofluorescence staining and western blotting, and the proliferation and migration abilities of VSMCs were detected by CCK-8, EDU, cell counting, scratch, and Transwell assays. RESULTS: TNF-α rapidly decreased the contractile phenotypic markers and elevated the synthetic phenotypic markers of VSMCs, as well as markedly increasing the proliferation and migration ability of VSMCs under two- and three-dimensional culture conditions. CONCLUSIONS: TNF-α can rapidly induce a phenotypic shift in VSMCs and change their viability on PGA scaffolds.

7.
Artigo em Inglês | MEDLINE | ID: mdl-38683453

RESUMO

Runt domain transcription factor 3 (RUNX3) suppresses many different cancer types and is disabled by mutations, epigenetic repression, or cytoplasmic mislocalization. In this study, we investigated whether oxidative stress is associated with RUNX3 accumulation from the nucleus to the cytoplasm in terms of histone modification. Oxidative stress elevated histone deacetylase (HDAC) level and lowered that of histone acetyltransferase. In addition, oxidative stress decreased the expression of mixed lineage leukemia (MLL), a histone methyltransferase, but increased the expression of euchromatic histone-lysine N-methyltransferase 2 (EHMT2/G9a), which is also a histone methyltransferase. Moreover, oxidative stress-induced RUNX3 phosphorylation, Src activation, and Jun activation domain-binding protein 1 (JAB1) expression were inhibited by knockdown of HDAC and G9a, restoring the nuclear localization of RUNX3 under oxidative stress. Cytoplasmic RUNX3 localization was followed by oxidative stress-induced histone modification, activated Src along with RUNX3 phosphorylation, and induction of JAB1, resulting in RUNX3 inactivation.

8.
J Proteome Res ; 23(5): 1713-1724, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38648079

RESUMO

Non-small-cell lung cancer (NSCLC), a common malignant tumor, requires deeper pathogenesis investigation. Autophagy is an evolutionarily conserved lysosomal degradation process that is frequently blocked during cancer progression. It is an urgent need to determine the novel autophagy-associated regulators in NSCLC. Here, we found that pirin was upregulated in NSCLC, and its expression was positively correlated with poor prognosis. Overexpression of pirin inhibited autophagy and promoted NSCLC proliferation. We then performed data-independent acquisition-based quantitative proteomics to identify the differentially expressed proteins (DEPs) in pirin-overexpression (OE) or pirin-knockdown (KD) cells. Among the pirin-regulated DEPs, ornithine decarboxylase 1 (ODC1) was downregulated in pirin-KD cells while upregulated along with pirin overexpression. ODC1 depletion reversed the pirin-induced autophagy inhibition and pro-proliferation effect in A549 and H460 cells. Immunohistochemistry showed that ODC1 was highly expressed in NSCLC cancer tissues and positively related with pirin. Notably, NSCLC patients with pirinhigh/ODC1high had a higher risk in terms of overall survival. In summary, we identified pirin and ODC1 as a novel cluster of prognostic biomarkers for NSCLC and highlighted the potential oncogenic role of the pirin/ODC1/autophagy axis in this cancer type. Targeting this pathway represents a possible therapeutic approach to treat NSCLC.


Assuntos
Autofagia , Carcinoma Pulmonar de Células não Pequenas , Proliferação de Células , Progressão da Doença , Neoplasias Pulmonares , Ornitina Descarboxilase , Feminino , Humanos , Masculino , Células A549 , Autofagia/genética , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/metabolismo , Ornitina Descarboxilase/metabolismo , Ornitina Descarboxilase/genética , Prognóstico , Regulação para Cima
9.
BMJ Case Rep ; 17(4)2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38642935

RESUMO

We describe a case of bowel perforation secondary to a recurrence of primary fallopian tube carcinoma treated more than a decade ago. A woman in her 70s presented to a rural centre with an acute abdomen. An abdominal CT showed a perforated ileum secondary to a pelvic mass. Emergency laparotomy identified the pelvic mass that was adherent to the side wall and invading the ileum at the site of perforation. Its adherence to the external iliac vessels posed a challenge to achieve en-bloc resection; therefore, a defunctioning loop ileostomy was created. Final histopathology and immunopathology were consistent with the recurrence of her primary fallopian tube carcinoma. The patient was further discussed in a multidisciplinary team meeting at a tertiary referral hospital. This case highlighted the importance of having a high index of suspicion for cancer recurrence, the utility of rapid source control laparotomy and multidisciplinary team patient management.


Assuntos
Carcinoma , Neoplasias das Tubas Uterinas , Perfuração Intestinal , Peritonite , Feminino , Humanos , Neoplasias das Tubas Uterinas/complicações , Neoplasias das Tubas Uterinas/cirurgia , Tubas Uterinas , Perfuração Intestinal/etiologia , Perfuração Intestinal/cirurgia , Recidiva Local de Neoplasia/complicações , Peritonite/etiologia , Peritonite/cirurgia , Idoso
11.
Environ Pollut ; 347: 123675, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38447650

RESUMO

Stimulation of human keratinocytes with particulate matter 2.5 (PM2.5) elicits complex signaling events, including a rise in the generation of reactive oxygen species (ROS). However, the mechanisms underlying PM2.5-induced ROS production remain unknown. Here, we show that PM2.5-induced ROS production in human keratinocytes is mediated via the NADPH oxidase (NOXs) system and the Ca2+ signaling pathway. PM2.5 treatment increased the expression of NOX1, NOX4, and a calcium-sensitive NOX, dual oxidase 1 (DUOX1), in human epidermal keratinocyte cell line. PM2.5 bound to aryl hydrocarbon receptor (AhR), and this complex bound to promoter regions of NOX1 and DUOX1, suggesting that AhR acted as a transcription factor of NOX1 and DUOX1. PM2.5 increased the transcription of DUOX1 via epigenetic modification. Moreover, a link between DNA demethylase and histone methyltransferase with the promoter regions of DUOX1 led to an elevation in the expression of DUOX1 mRNA. Interestingly, PM2.5 increased NOX4 expression and promoted the interaction of NOX4 and Ca2+ channels within the cytoplasmic membrane or endoplasmic reticulum, leading to Ca2+ release. The increase in intracellular Ca2+ concentration activated DUOX1, responsible for ROS production. Our findings provide evidence for a PM2.5-mediated ROS-generating system network, in which increased NOX1, NOX4, and DUOX1 expression serves as a ROS signal through AhR and Ca2+ activation.


Assuntos
NADPH Oxidases , Receptores de Hidrocarboneto Arílico , Humanos , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Oxidases Duais/genética , Oxidases Duais/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Material Particulado/toxicidade , Epigênese Genética
12.
Int J Med Sci ; 21(4): 681-689, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38464827

RESUMO

Background: The exposure of the human skin to particulate matter 2.5 (PM2.5) results in adverse health outcomes, such as skin aging, wrinkle formation, pigment spots, and atopic dermatitis. It has previously been shown that rosmarinic acid (RA) can protect keratinocytes from ultraviolet B radiation by enhancing cellular antioxidant systems and reducing oxidative damage; however, its protective action against the adverse effects of PM2.5 on skin cells remains unclear. Therefore, in this study, we explored the mechanism underlying the protective effects of RA against PM2.5-mediated oxidative stress in HaCaT keratinocytes. Methods: HaCaT keratinocytes were pretreated with RA and exposed to PM2.5. Thereafter, reactive oxygen species (ROS) production, protein carbonylation, lipid peroxidation, DNA damage, and cellular apoptosis were investigated using various methods, including confocal microscopy, western blot analysis, and flow cytometry. Results: RA significantly inhibited PM2.5-induced lipid peroxidation, protein carbonylation, DNA damage, increases in intracellular Ca2+ level, and mitochondrial depolarization. It also significantly attenuated PM2.5-induced apoptosis by downregulating Bcl-2-associated X, cleaved caspase-9, and cleaved caspase-3 protein levels, while upregulating B-cell lymphoma 2 protein level. Further, our results indicated that PM2.5-induced apoptosis was associated with the activation of the mitogen-activated protein kinase (MAPK) signaling pathway and that MAPK inhibitors as well as RA exhibited protective effects against PM2.5-induced apoptosis. Conclusion: RA protected HaCaT cells from PM2.5-induced apoptosis by lowering oxidative stress.


Assuntos
Material Particulado , Ácido Rosmarínico , Humanos , Material Particulado/toxicidade , Linhagem Celular , Queratinócitos , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Apoptose
13.
Int Ophthalmol ; 44(1): 3, 2024 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-38315299

RESUMO

PURPOSE: To introduce the treatment of diabetic macular edema (DME) with subthreshold micropulse diode laser (SMPL), to summarize the biological impact, therapeutic effects, and safety of this treatment, and to discuss the response to DME when SMPL is combined with anti-vascular endothelial growth factor (anti-VEGF) or steroid. METHODS: The literature search was performed on the PubMed database, with a selection of English-language articles published from 2000 to 2023 with the following combinations of search terms: diabetes macular (o) edema, micropulse laser or subthreshold micropulse laser, anti-vascular endothelial growth factor, and steroid. RESULTS: SMPL is a popular, invisible retinal laser phototherapy that is inexpensive, safe, and effective in the treatment of DME. It can selectively target the retinal pigment epithelium, reduce the expression of pro-inflammatory factors, promote the absorption of macular edema, and exert a similar and lasting clinical effect to traditional lasers. No significant difference was found in the therapeutic effects of SMPL between different wavelengths. However, HbA1c level and pretreatment central macular thickness (CMT) may affect the therapeutic outcomes of SMPL. CONCLUSION: SMPL has a slow onset and produces lasting clinical effects similar to conventional photocoagulation. It has been reported that SMPL combined with the intravitreal anti-VEGF injection can significantly reduce the number of injections without influencing the therapeutic effect, which is essential for clinical applications and research. Although 577 nm SMPL is widely used clinically, there are no standardized protocols for SMPL. Additionally, some important problems regarding the treatment of SMPL require further discussion and exploration.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Edema Macular , Humanos , Retinopatia Diabética/complicações , Retinopatia Diabética/diagnóstico , Retinopatia Diabética/cirurgia , Edema Macular/diagnóstico , Edema Macular/etiologia , Edema Macular/cirurgia , Lasers Semicondutores/uso terapêutico , Fatores de Crescimento Endotelial , Fotocoagulação a Laser/métodos , Esteroides , Resultado do Tratamento , Tomografia de Coerência Óptica
14.
Mar Drugs ; 22(2)2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38393029

RESUMO

Five new diisoprenyl cyclohexene-type meroterpenoids, aspergienynes J-N (1-5), along with three known analogues (6-8), were obtained from the mangrove endophytic fungal strain Aspergillus sp. GXNU-Y85. The chemical structures, including their absolute configurations, were established via spectroscopic data and comparison of experimental and calculated ECD spectra. Cytotoxicity assay results indicated that compound 8 had strong cytotoxicity against HeLa cancer cells, and its IC50 value was 11.8 µM. In addition, flow cytometry analysis revealed that the cytotoxicity of 8 was due to the induction of G1 cell cycle arrest and apoptosis in HeLa cells.


Assuntos
Antineoplásicos , Aspergillus , Humanos , Estrutura Molecular , Células HeLa , Aspergillus/química , Análise Espectral , Antineoplásicos/farmacologia , Antineoplásicos/metabolismo
15.
Anticancer Res ; 44(3): 1079-1086, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38423648

RESUMO

BACKGROUND/AIM: Melanoma is a prevalent malignant tumor that arises from melanocytes. The treatment of malignant melanoma has become challenging due to the development of drug resistance. It is, therefore, imperative to identify novel therapeutic drug candidates for controlling malignant melanoma. Naringenin is a flavonoid abundant in oranges and other citrus fruits and recognized for its numerous medicinal benefits. The objective of the study was to assess the anti-carcinogenic potential of naringenin by evaluating its ability to regulate the cellular production of reactive oxygen species (ROS) and its effect on mitochondrial function and apoptosis in melanoma cells. MATERIALS AND METHODS: Cell viability, intracellular ROS levels, cell apoptosis, and mitochondrial functions were evaluated. RESULTS: Naringenin decreased melanoma cell viability and triggered generation of ROS, leading to cell apoptosis. In addition, it stimulated mitochondrial damage in melanoma cells by elevating the levels of Ca2+ and ROS in the mitochondria and decreasing cellular ATP. Naringenin stimulated the expression of proapoptotic proteins, including phospho p53, B-cell lymphoma-2 (Bcl-2)-associated X protein, cleaved caspase-3, and cleaved caspase-9, in melanoma cells in a time-dependent manner. Furthermore, it reduced the expression of the anti-apoptotic protein Bcl-2. Naringenin triggered cell apoptosis by phosphorylating c-Jun N-terminal kinase and stimulating cellular autophagy. CONCLUSION: Naringenin caused oxidative stress and mitochondrial damage, and activated autophagy in melanoma cells, leading to cell apoptosis. These findings indicate the potential of naringenin as a new therapeutic candidate for melanoma.


Assuntos
Flavanonas , Melanoma , Humanos , Espécies Reativas de Oxigênio/metabolismo , Melanoma/patologia , Linhagem Celular Tumoral , Apoptose , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Potencial da Membrana Mitocondrial
16.
J Colloid Interface Sci ; 660: 440-448, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38244509

RESUMO

This study employed a one-step hydrothermal process to synthesize Ni3S2/Fe3O4 nanoblocks in situ on nickel foam (NF). The resulting Ni3S2/Fe3O4/NF catalyst demonstrates exceptional electrocatalytic activity for the oxygen evolution reaction (OER) and robust long-term stability. It achieves a low overpotential of only 220 mV for a current density of 10 mA cm-2 with a Tafel slope of 54.1 mV dec-1 and remains stable in 1.0 M KOH for 66 h. The binder-free self-supported three-dimensional nanoblocks enhance the reaction region and long-term stability. Electronic interactions between Fe3O4 and Ni3S2, coupled with heterogeneous interfaces, optimize the electronic structure, fostering the formation of highly reactive species. Density-functional theory (DFT) calculations confirm that Ni3S2/Fe3O4, with a heterogeneous interfacial structure, modulates the chemisorption of reaction intermediates on the catalyst surface, optimizing the Gibbs free energies (ΔG) of oxygen-containing intermediates. The synergistic effect between the two active materials within the heterogeneous structure enhances OER catalytic performance. This finding offers a valuable approach to designing efficient and stable OER electrocatalysts.

17.
J Colloid Interface Sci ; 661: 91-101, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38295706

RESUMO

A high-temperature-resistance insulating layer with high thermal conductivity is the key component for fabricating the instant metal-based electric heating tube. However, it is still a challenge for materials to possess excellent high-temperature resistance, superior insulating property, and high thermal conductivity at the same time. Here, a novel SiO2 bridged AlN/MSR composite based on methylphenyl silicone resin (MSR) and AlN filler was reported. MSR with a high thermal decomposition temperature of 452.0 °C and a high withstand voltage of 5.6 kV was first synthesized by adjusting the contents of alkyl and phenyl groups. The superior high-temperature resistant insulating property is 3.7 and 2.4 times higher than the national standard requirement of 1.5 kV and commercial silicone resin, respectively. The hydrogen bonds formed between SiO2, AlN, and MSR and the electrostatic adsorption between SiO2 and AlN can remarkably improve the uniform dispersion of AlN in MSR and thus enhance the insulating property, thermal conductivity, and thermal stability. With the addition of 2 wt% SiO2 and 50 wt% AlN, the SiO2-AlN/MSR composite exhibits an extremely high withstand voltage of 7.3 kV, a high thermal conductivity of 0.553 W·m-1·K-1, and an enhanced decomposition temperature of 475 °C. The superior insulating property and thermal conductivity are 4.9 and 1.3 times higher than the national standard requirement and pure MSR, respectively. This novel composite shows great potential for application in the fields requiring integrated superior insulating property, high-temperature resistance, and high thermal conductivity.

18.
Intensive Crit Care Nurs ; 82: 103632, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38290221

RESUMO

OBJECTIVES: To explore the differences in post-intensive care unit memory and posttraumatic stress disorder symptoms between patients with and without delirium, and assess the correlations between the two. DESIGN: Prospective cohort observation study. SETTING: A cardiac intensive care unit of a tertiary hospital in China. We enrolled 318 consecutive patients after cardiac surgery between December 2017 and March 2019. MAIN OUTCOME MEASURES: Delirium was assessed using the Confusion Assessment Method for the ICU from intensive care unit admission to discharge. Intensive care unit memory was assessed using the ICU-Memory Tool through face-to-face interviews one week after discharge. Posttraumatic stress disorder was measured telephonically using the Impact of Events Scale-revised questionnaire at three months post-discharge. RESULTS: Eighty patients each in the delirium and non-delirium groups were enrolled for follow-up interviews. Patients with delirium had vaguer memories of pre-intensive care unit admission and of their stay, and recollected more memories of feelings (vs. without delirium). Posttraumatic stress disorder was diagnosed in 14 patients with and in seven without delirium, with non-significant differences between groups. Delirium did not influence post-intensive care unit factual, feeling, and delusional memories, nor posttraumatic stress disorder and hyperarousal, intrusion, and avoidance. The memories of feelings were positively correlated with the last three (r = 0.285, r = 0.390 and r = 0.373, respectively). CONCLUSION: Patients with delirium had vague intensive care unit memories. Memories of feelings were positively correlated with symptoms of hyperarousal, intrusion, and avoidance. Delirium did not influence factual, feeling, or delusional memories nor posttraumatic stress disorder incidence and symptoms. IMPLICATIONS FOR CLINICAL PRACTICE: Interventions are needed to reduce the impact of vague memory in patients with post-intensive care unit delirium. Memories of feelings should be focused on because of their correlation with hyperarousal, intrusion, and avoidance. Delirium prevention and early recognition measures are suggested.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Delírio , Transtornos de Estresse Pós-Traumáticos , Humanos , Assistência ao Convalescente , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Cuidados Críticos , Delírio/complicações , Unidades de Terapia Intensiva , Alta do Paciente , Estudos Prospectivos , Transtornos de Estresse Pós-Traumáticos/complicações
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