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1.
Immunity ; 54(3): 454-467.e6, 2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33561388

RESUMO

Heparin, a mammalian polysaccharide, is a widely used anticoagulant medicine to treat thrombotic disorders. It is also known to improve outcomes in sepsis, a leading cause of mortality resulted from infection-induced immune dysfunction. Whereas it is relatively clear how heparin exerts its anticoagulant effect, the immunomodulatory mechanisms enabled by heparin remain enigmatic. Here, we show that heparin prevented caspase-11-dependent immune responses and lethality in sepsis independent of its anticoagulant properties. Heparin or a chemically modified form of heparin without anticoagulant function inhibited the alarmin HMGB1-lipopolysaccharide (LPS) interaction and prevented the macrophage glycocalyx degradation by heparanase. These events blocked the cytosolic delivery of LPS in macrophages and the activation of caspase-11, a cytosolic LPS receptor that mediates lethality in sepsis. Survival was higher in septic patients treated with heparin than those without heparin treatment. The identification of this previously unrecognized heparin function establishes a link between innate immune responses and coagulation.


Assuntos
Anticoagulantes/uso terapêutico , Caspases/metabolismo , Heparina/uso terapêutico , Macrófagos/imunologia , Sepse/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Caspases/genética , Linhagem Celular , Feminino , Glucuronidase/genética , Glucuronidase/metabolismo , Glicocálix/metabolismo , Proteína HMGB1/metabolismo , Humanos , Imunomodulação , Lipopolissacarídeos/metabolismo , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Sepse/mortalidade , Análise de Sobrevida , Adulto Jovem
2.
Plant Cell ; 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38875155

RESUMO

Plants respond to cold stress at multiple levels, including increasing cytosolic calcium (Ca2+) influx and triggering the expression of cold-responsive genes. Here we show that the Ca2+-permeable channel CYCLIC NUCLEOTIDE GATED CHANNEL20 (CNGC20) positively regulates freezing tolerance in Arabidopsis (Arabidopsis thaliana) by mediating cold-induced Ca2+ influx. Moreover, we demonstrate that the leucine-rich repeat receptor-like kinase PLANT PEPTIDE CONTAINING SULFATED TYROSINE1 RECEPTOR (PSY1R) is activated by cold, phosphorylating and enhancing the activity of CNGC20. The psy1r mutant exhibited decreased cold-evoked Ca2+ influx and freezing tolerance. Conversely, COLD-RESPONSIVE PROTEIN KINASE1 (CRPK1), a protein kinase that negatively regulates cold signaling, phosphorylates and facilitates the degradation of CNGC20 under prolonged periods of cold treatment, thereby attenuating freezing tolerance. This study thus identifies PSY1R and CRPK1 kinases that regulate CNGC20 activity and stability, respectively, thereby antagonistically modulating freezing tolerance in plants.

3.
J Lipid Res ; 65(2): 100499, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38218337

RESUMO

Ferroptosis is a novel cell death mechanism that is mediated by iron-dependent lipid peroxidation. It may be involved in atherosclerosis development. Products of phospholipid oxidation play a key role in atherosclerosis. 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphocholine (PGPC) is a phospholipid oxidation product present in atherosclerotic lesions. It remains unclear whether PGPC causes atherosclerosis by inducing endothelial cell ferroptosis. In this study, human umbilical vein endothelial cells (HUVECs) were treated with PGPC. Intracellular levels of ferrous iron, lipid peroxidation, superoxide anions (O2•-), and glutathione were detected, and expression of fatty acid binding protein-3 (FABP3), glutathione peroxidase 4 (GPX4), and CD36 were measured. Additionally, the mitochondrial membrane potential (MMP) was determined. Aortas from C57BL6 mice were isolated for vasodilation testing. Results showed that PGPC increased ferrous iron levels, the production of lipid peroxidation and O2•-, and FABP3 expression. However, PGPC inhibited the expression of GPX4 and glutathione production and destroyed normal MMP. These effects were also blocked by ferrostatin-1, an inhibitor of ferroptosis. FABP3 silencing significantly reversed the effect of PGPC. Furthermore, PGPC stimulated CD36 expression. Conversely, CD36 silencing reversed the effects of PGPC, including PGPC-induced FABP3 expression. Importantly, E06, a direct inhibitor of the oxidized 1-palmitoyl-2-arachidonoyl-phosphatidylcholine IgM natural antibody, inhibited the effects of PGPC. Finally, PGPC impaired endothelium-dependent vasodilation, ferrostatin-1 or FABP3 inhibitors inhibited this impairment. Our data demonstrate that PGPC impairs endothelial function by inducing endothelial cell ferroptosis through the CD36 receptor to increase FABP3 expression. Our findings provide new insights into the mechanisms of atherosclerosis and a therapeutic target for atherosclerosis.


Assuntos
Aterosclerose , Cicloexilaminas , Ferroptose , Fenilenodiaminas , Animais , Camundongos , Humanos , Fosfolipídeos , Fosforilcolina , Éteres Fosfolipídicos/metabolismo , Éteres Fosfolipídicos/farmacologia , Camundongos Endogâmicos C57BL , Células Endoteliais da Veia Umbilical Humana/metabolismo , Endotélio/metabolismo , Glutationa/metabolismo , Ferro/metabolismo , Proteína 3 Ligante de Ácido Graxo
4.
J Cell Mol Med ; 28(12): e18449, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38924214

RESUMO

Mitochondrial dynamics has emerged as an important target for neuronal protection after cerebral ischaemia/reperfusion. Therefore, the aim of this study was to investigate the mechanism by which ARMC10 regulation of mitochondrial dynamics affects mitochondrial function involved in ischaemic stroke (IS). Mitochondrial morphology was detected by laser scanning confocal microscopy (LSCM), and mitochondrial ultrastructural alterations were detected by electron microscopy. The expression of mitochondrial dynamics-related genes Drp1, Mfn1, Mfn2, Fis1, OPA1 and ARMC10 and downstream target genes c-Myc, CyclinD1 and AXIN2 was detected by RT-qPCR. Western blot was used to detect the protein expression of ß-catenin, GSK-3ß, p-GSK-3ß, Bcl-2 and Bax. DCFH-DA fluorescent probe was to detect the effect of ARMC10 on mitochondrial ROS level, Annexin V-FITC fluorescent probe was to detect the effect of ARMC10 on apoptosis, and ATP assay kit was to detect the effect of ARMC10 on ATP production. Mitochondrial dynamics was dysregulated in clinical IS samples and in the OGD/R cell model, and the relative expression of ARMC10 gene was significantly decreased in IS group (p < 0.05). Knockdown and overexpression of ARMC10 could affect mitochondrial dynamics, mitochondrial function and neuronal apoptosis. Agonist and inhibitor affected mitochondrial function and neuronal apoptosis by targeting Wnt/ß-Catenin signal pathway. In the OGD/R model, ARMC10 affected mitochondrial function and neuronal apoptosis through the mechanism that regulates Wnt/ß-catenin signalling pathway. ARMC10 regulates mitochondrial dynamics and protects mitochondrial function by activating Wnt/ß-catenin signalling pathway, to exert neuroprotective effects.


Assuntos
Apoptose , Proteínas do Domínio Armadillo , AVC Isquêmico , Mitocôndrias , Dinâmica Mitocondrial , Via de Sinalização Wnt , Mitocôndrias/metabolismo , Humanos , AVC Isquêmico/metabolismo , AVC Isquêmico/genética , AVC Isquêmico/patologia , Proteínas do Domínio Armadillo/metabolismo , Proteínas do Domínio Armadillo/genética , Masculino , beta Catenina/metabolismo , beta Catenina/genética , Espécies Reativas de Oxigênio/metabolismo , Isquemia Encefálica/metabolismo , Isquemia Encefálica/genética , Isquemia Encefálica/patologia , Animais
5.
Am Heart J ; 272: 69-85, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38490563

RESUMO

BACKGROUND: We aimed to develop and validate a model to predict 1-year mortality risk among patients hospitalized for acute heart failure (AHF), build a risk score and interpret its application in clinical decision making. METHODS: By using data from China Patient-Centred Evaluative Assessment of Cardiac Events Prospective Heart Failure Study, which prospectively enrolled patients hospitalized for AHF in 52 hospitals across 20 provinces, we used multivariate Cox proportional hazard model to develop and validate a model to predict 1-year mortality. RESULTS: There were 4,875 patients included in the study, 857 (17.58%) of them died within 1-year following discharge of index hospitalization. A total of 13 predictors were selected to establish the prediction model, including age, medical history of chronic obstructive pulmonary disease and hypertension, systolic blood pressure, Kansas City Cardiomyopathy Questionnaire-12 score, angiotensin converting enzyme inhibitor or angiotensin receptor blocker at discharge, discharge symptom, N-terminal pro-brain natriuretic peptide, high-sensitivity troponin T, serum creatine, albumin, blood urea nitrogen, and highly sensitive C-reactive protein. The model showed a high performance on discrimination (C-index was 0.759 [95% confidence interval: 0.739, 0.778] in development cohort and 0.761 [95% confidence interval: 0.731, 0.791] in validation cohort), accuracy, calibration, and outperformed than several existed risk scores. A point-based risk score was built to stratify low- (0-12), intermediate- (13-16), and high-risk group (≥17) among patients. CONCLUSIONS: A prediction model using readily available predictors was developed and internal validated to predict 1-year mortality risk among patients hospitalized for AHF. It may serve as a useful tool for individual risk stratification and informing decision making to improve clinical care.


Assuntos
Insuficiência Cardíaca , Hospitalização , Humanos , Insuficiência Cardíaca/mortalidade , Masculino , Feminino , China/epidemiologia , Idoso , Medição de Risco/métodos , Doença Aguda , Hospitalização/estatística & dados numéricos , Estudos Prospectivos , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Modelos de Riscos Proporcionais , Peptídeo Natriurético Encefálico/sangue , Troponina T/sangue , Proteína C-Reativa/análise , Fragmentos de Peptídeos/sangue
6.
Langmuir ; 40(14): 7384-7394, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38530344

RESUMO

Photocatalytic technology is a popular research area for converting solar energy into environmentally friendly chemicals and is considered the greenest approach for producing H2O2. However, the corresponding reactive oxygen species (ROS) and pathway involved in the photocatalytic generation of H2O2 by the Bi2.15WO6-glucose system are still not clear. Quenching experiments have established that neither •OH nor h+ contribute to the formation of H2O2, and show that the formed surface superoxo (≡Bi-OO•) and peroxo (≡Bi-OOH) species are the predominant ROS in H2O2 generation. In addition, various characterizations indicate the enhanced electron-transfer on the surface of Bi2.15WO6 with increasing contents of glucose via the ligand-to-metal charge transfer pathway, confirming H-transfer from glucose to ≡Bi-OO• or ≡Bi-OOH. The increased production of H2O2 with decreasing bond dissociation energy (BDEO-H) values of various phenolic compounds again supports the H-transfer mechanism from phenolic compounds to ≡Bi-OO• and then to ≡Bi-OOH. DFT calculations further reveal that on the Bi2.15WO6 surface, oxygen is sequentially reduced to ≡Bi-OO• and ≡Bi-OOH, while H-transfer from H2O or glucose to ≡Bi-OO• and ≡Bi-OOH, resulting in the production of H2O2. The lower energy barrier of H-transfer from adsorbed glucose (0.636 eV) than that from H2O (1.157 eV) indicates that H-transfer is more favorable from adsorbed glucose. This work gives new insight into the photocatalytic generation of H2O2 by Bi2.15WO6 in the presence of glucose/phenolic compounds via the H-abstraction pathway.

7.
Pediatr Res ; 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38877281

RESUMO

BACKGROUND: To investigate the concurrent, long-term, and future adverse events and assess the trend of adverse events in pediatric patients with patent ductus arteriosus (PDA) after transcatheter closure. METHODS: A total of 1590 patients underwent transcatheter PDA closure were enrolled, including 465 patients (median age = 22 months) in the training group and 1125 patients in the validation group. Logistic regression analysis was used to assess independent risk factors associated with concurrent adverse events after closure. The chi-square test was used to evaluate the 5-year follow-up trend. RESULTS: Multivariable logistic regression analysis indicated that low age, female, and high pulmonary end diameter were independent risk factors for concurrent adverse events after closure. For patients without concurrent adverse events and for those who with concurrent adverse events but return to normal, the Chi-square test showed no abnormal results at the 5-year follow-up. Furthermore, the follow-up data of the validation group were not significantly different from those of the training group. CONCLUSION: The value of long-term follow-up of children may be limited for those who did not have a concurrent adverse event after closure nor for those who had a concurrent adverse event after closure but returned to normal during the 5-year follow-up period. IMPACT: Follow-up monitoring of adverse events tended to be recommended in pediatric patients with PDA after transcatheter closure. However, follow-up in these pediatric patients is expensive and there is a risk of sedation for echocardiography examination frequently. ·Patients who had no concurrent adverse events after closure did not show any abnormality at 5-year follow-up. ·Most of the patients who had concurrent adverse events after closure returned to normal at 5-year follow-up. The value of long-term follow-up may be limited for the above patients after transcatheter PDA closure.

8.
Nanotechnology ; 35(37)2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38861971

RESUMO

HfO2-based ferroelectric materials as the most promising candidate for the ferroelectric memories, have been widely studied for more than a decade due to their excellent ferroelectric properties and CMOS compatibility. In order to realize its industrialization as soon as possible, researchers have been devoted to improving the reliability performance, such as wake up, imprint, limited endurance, et al. Among them, the breakdown characteristic is one of main failure mechanisms of HfO2-based ferroelectric devices, which limits the write/read reliability of the devices. Based on this, we systematically studied the effect of thickness on the time-dependent dielectric breakdown (TDDB) tolerate capability of HfO2-ZrO2(HZO) FE films under both forward and reverse electrical stress conditions. The thickness of HZO FE film ranged from 6 to 20 nm. Our findings reveal that decreasing the thickness of the HZO FE film leads to an improvement in TDDB tolerance capability which is attributed to the fact that higher density of oxygen vacancies in thinner HZO FE films can effectively inhibit the generation of new oxygen vacancies and the growth of conductive filaments, thus effectively improving the TDDB characteristics. These results provide a potential solution for mitigating breakdown characteristics of HfO2-based ferroelectric devices in memory applications.

9.
Environ Sci Technol ; 58(1): 371-380, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38146194

RESUMO

Cyclic desulfurization-regeneration-denitrification based on metal-free carbon materials is one of the most promising ways to remove NOx and SO2 simultaneously. However, the impact of S-doping induced by the cyclic desulfurization and regeneration (C-S-R) process on the selective catalytic reduction (SCR) is not well understood. Herein, it is demonstrated that the C-S-R process at 500 °C induces in situ S-doping with a significant accumulation of C-S-C structures. NOx conversion was dramatically enhanced from 18.95% of the original sample to 84.55% of the S-doped sample. Density functional theory calculations revealed that the C-S-C structure significantly regulates the electronic structure of the C atom adjacent to the ketonic carbonyl group, thereby significantly altering the NH3 adsorption configuration with superior adsorption capacity. Moreover, S-doping induces an extra electron transfer between the N atom of the NH3 molecule and the C atom of the carbon plane, thereby promoting the activation of NH3 over the ketonic carbonyl group with a reduced energy barrier. This study elucidates a synergetic promotional mechanism between the ketonic carbonyl group and the C-S-C structure for SCR, offering a novel design strategy for high-performance heteroatom-doped carbon catalysts in industrial applications.


Assuntos
Amônia , Carbono , Oxirredução , Amônia/química , Metais , Titânio , Catálise
10.
Environ Sci Technol ; 58(4): 2133-2143, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38237035

RESUMO

The byproduct formation in environmental catalysis is strongly influenced by the chemical state and coordination of catalysts. Herein, two Pd/CeO2 catalysts (PdCe-350 and PdCe-800) with varying oxygen vacancies (Ov) and coordination numbers (CN) of Pd were prepared to investigate the mechanism of N2O and NH3 formation during NO reduction by CO. PdCe-350 exhibits a higher density of Ov and Pd sites with higher CN, leading to an enhanced metal-support interaction by electron transformation from the support to Pd. Consequently, PdCe-350 displayed increased levels of byproduct formation. In situ spectroscopies under dry and wet conditions revealed that at low temperatures, the N2O formation strongly correlated with the Ov density through the decomposition of chelating nitro species on PdCe-350. Conversely, at high temperatures, it was linked to the reactivity of Pd species, primarily facilitated by monodentate nitrates on PdCe-800. In terms of NH3 formation, its occurrence was closely associated with the activation of H2O and C3H6, since a water-gas shift or hydrocarbon reforming could provide hydrogen. Both bridging and monodentate nitrates showed activity in NH3 formation, while hyponitrites were identified as key intermediates for both catalysts. The insights provide a fundamental understanding of the intricate relationship among the local coordination of Pd, surface Ov, and byproduct distribution.


Assuntos
Oxigênio , Água , Oxirredução , Análise Espectral , Nitratos/química , Catálise
11.
BMC Anesthesiol ; 24(1): 27, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38233828

RESUMO

BACKGROUND: Previous studies have examined anesthetics to improve postoperative prognosis after knee arthroscopic surgery. However, it is currently unknown whether perioperative anesthetics can influence postoperative hospital stay. We investigated the impact of esketamine after knee arthroscopic surgery on post-operative length of stay, fever and surgical site infection. METHODS: This study included 455 patients who underwent knee surgery between January2020 and August 2021at a tertiary hospital in China. Patient characteristics, preoperative laboratory values, intra-operative anesthetic data, and postoperative outcomes were collected. Univariate and multivariate logistic regression analyses with or without propensity score matching were performed to identify factors related to post-operative discharge within 3 days(PD3). RESULTS: A total of 297 cases met our inclusion criteria. The mean age of patients was 42 ± 14 years, mean body mass index, 24.1 ± 3.5 kg/m2, 157(53%) patients were male. Meniscus-related procedures accounted for the most part of all the procedures with a percentage of 40.4%, followed by combined procedures of 35.4%. After we adjusted for demographic and intraoperative characteristics with propensity score matching, esketamine use was significantly associated with PD3 with the highest odds ratio of 2.28 (95% confidence interval (CI): 1.18-4.41, p = 0.014). CONCLUSION: Esketamine use was associated with PD3 in patients underwent knee arthroscopic surgery. The findings of this study will be useful to anesthesiologists in making informed decisions regarding the choice of anesthetics for knee joint diseases. TRIAL REGISTRATION: This study was approved by the Ethics Committee (Approval No.:2023-041-01) of the Eighth Affiliated Hospital, Sun Yat-sen University and retrospectively registered.


Assuntos
Anestésicos , Artroscopia , Ketamina , Humanos , Masculino , Adulto , Pessoa de Meia-Idade , Feminino , Estudos de Coortes , Tempo de Internação , Artroscopia/métodos , Pontuação de Propensão , Hospitais , Estudos Retrospectivos , Complicações Pós-Operatórias/etiologia
12.
J Invertebr Pathol ; 203: 108076, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38382734

RESUMO

Beauveria bassiana is one of the most extensively studied entomopathogenic fungi (EPF) and is widely used as a biocontrol agent against various insect pests. Proteins containing the MARVEL domain are conserved in eukaryotes, typically with four transmembrane structures. In this study, we identified the five MARVEL domain proteins in B. bassiana. Five MARVEL domain proteins were localized to cytomembrane and vacuoles in B. bassiana, but had different roles in maintaining the lipid-droplet homeostasis. These proteins were required for fungal virulence, but differentially contributed to fungal utilization of nutrients, stress tolerance, and development under aerial and submerged conditions. Notably, BbMARVEL2 was essential for conidial surface morphology. Additionally, these five MARVEL domain proteins contributed to fungal interaction with the host immune defense. This study provides new mechanistic insights into the life cycle of B. bassiana as a biocontrol agent.


Assuntos
Beauveria , Animais , Virulência , Proteínas Fúngicas/metabolismo , Insetos/microbiologia , Proteínas com Domínio MARVEL/metabolismo , Esporos Fúngicos
13.
Nano Lett ; 23(24): 11899-11906, 2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38071625

RESUMO

Cu-based catalysts possess great potential in the electrocatalytic nitrate (NO3-) reduction reaction for ammonia (NH3) synthesis. However, the low atomic economy limits their further application. Here we report a Cu single-atom (SA) incorporated in nitrogen-doped carbon (Cu SA/NC) with high atomic economy, which exhibits superior NH3 Faradaic efficiency (FE) of 100% along with an impressive NH3 yield rate of 7480 µg h-1 mgcat.-1. As counterparts, Cus+n/NC, with mixed SA and nanoparticles (NPs), shows decreasing NH3 FE with decreasing SA content, but the production of N2 and N2O increases gradually, which reaches the maximum on pure Cu NPs. In situ characterizations and theoretical calculations reveal that a higher NH3 FE of Cu SA/NC is ascribed to a lower free energy of the rate-limiting step (HNO* → N*) and effective inhibition for the N-N coupled process. This work provides the intuitive activity trends of Cu-based catalysts, opening an avenue for subsequent catalysts design.

14.
Int Orthop ; 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38806820

RESUMO

PURPOSE: Robot-assisted total knee arthroplasty (TKA) was developed to improve the precision and accuracy of implant placement in conventional TKA. However, the angular differences between referenced axes in robot-assisted TKA and conventional TKA remain unclear. The aim of this study was to investigate the angular differences in sagittal alignment between robot-assisted TKA and conventional TKA for both the femur and the tibia and to discuss their clinical implications. METHODS: We conducted a retrospective analysis of data from 100 patients (97 patients) who underwent computed tomography (CT) for Mako TKA. We measured the angle between the robot femoral axis (RFA) and conventional femoral axis (CFA) in the sagittal plane and the angle between the robot tibial axis (RTA) and the conventional tibial axis (CTA). Angles were compared between the sexes. Correlation analysis was conducted between the angles and height. RESULTS: In the sagittal plane, the mean RFA-CFA angle was 2.2° ± 1.6°, and the mean RTA-CTA angle was 2.3° ± 1.6°. There were no significant differences between the two angles among males and females (p > 0.05). There was a correlation between the RFA-CFA angle and RTA-CTA angle (p < 0.001, r = 0.33), and there was a correlation between height and the combination of the RFA-CFA angle and RTA-CTA angle (p = 0.03, r = 0.22). CONCLUSION: There are angular differences between the axes referenced by robot-assisted TKA and those referenced by conventional TKA, which may be influenced by patient height. Correctly understanding these differences is crucial when evaluating the implant position and surgical outcomes after robot-assisted TKA. Furthermore, caution should be taken when assessing the flexion-extension angle of the knee since the angles displayed in the Mako system are different from the angles measured with intramedullary anatomical axes. After all, sagittal alignment principles differ between robot-assisted and conventional TKA; however, further studies are required to determine which principle is more appropriate or to modify these principles.

15.
J Sci Food Agric ; 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38591367

RESUMO

BACKGROUND: Goat milk is considered a nutritionally superior resource, owing to its advantageous nutritional attributes. Nevertheless, it is susceptible to spoilage and the persistence of pathogens. Electron beam irradiation stands as a promising non-thermal processing technique capable of prolonging shelf life with minimal residue and a high degree of automation. RESULTS: The effects of electron beam irradiation (2, 3, 5, and 7 kGy) on microorganisms, physicochemical properties, and protein structure of goat milk compared with conventional pasteurized goat milk (PGM) was evaluated. It was found that a 2 kGy electron beam irradiation reduces the total microbial count of goat milk by 6-logs, and the irradiated goat milk protein secondary structure showed a significant decrease in ɑ-helix content. Low irradiation doses led to microaggregation and crosslinking. In contrast, high doses (≥ 5 kGy) slightly disrupted the aggregates and decreased the particle size, disrupting the microscopic surface structure of goat milk, verified by scanning electron microscopy and confocal laser scanning microscopy. CONCLUSION: The irradiation of goat milk with a 2 kGy electron beam may effectively inactivate harmful microorganisms in the milk and maintain/or improve the physicochemical quality and protein structure of goat milk compared to thermal pasteurization. © 2024 Society of Chemical Industry.

16.
Small ; 19(20): e2207695, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36793161

RESUMO

As a traditional method of ammonia (NH3 ) synthesis, Haber-Bosch method expends a vast amount of energy. An alternative route for NH3 synthesis is proposed from nitrate (NO3 - ) via electrocatalysis. However, the structure-activity relationship remains challenging and requires in-depth research both experimentally and theoretically. Here an N-coordinated Cu-Ni dual-single-atom catalyst anchored in N-doped carbon (Cu/Ni-NC) is reported, which has competitive activity with a maximal NH3 Faradaic efficiency of 97.28%. Detailed characterizations demonstrate that the high activity of Cu/Ni-NC mainly comes from the contribution of Cu-Ni dual active sites. That is, (1) the electron transfer (Ni â†’ Cu) reveals the strong electron interaction of Cu-Ni dual-single-atom; (2) the strong hybridizations of Cu 3d-and Ni 3d-O 2p orbitals of NO3 - can accelerate electron transfer from Cu-Ni dual-site to NO3 - ; (3) Cu/Ni-NC can effectively decrease the rate-limiting step barriers, suppress N-N coupling for N2 O and N2 formation and hydrogen production.

17.
Clin Sci (Lond) ; 137(10): 823-841, 2023 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-37184210

RESUMO

The present study aims to investigate the role of AKT2 in the pathogenesis of hepatic and cardiac lipotoxicity induced by lipid overload-induced obesity and identify its downstream targets. WT and Akt2 KO mice were fed either normal diet, or high-fat diet (HFD) to induce obesity model in vivo. Human hepatic cell line (L02 cells) and neonatal rat cardiomyocytes (NRCMs) were used as in vitro models. We observed that during HFD-induced obesity, Akt2 loss-of-function mitigated lipid accumulation and oxidative stress in the liver and heart tissue. Mechanistically, down-regulation of Akt2 promotes SIRT6 expression in L02 cells and NRCMs, the latter deacetylates SOD2, which promotes SOD2 activity and therefore alleviates oxidative stress-induced injury of hepatocytes and cardiomyocytes. Furthermore, we also proved that AKT2 inhibitor protects hepatocytes and cardiomyocytes from HFD-induced oxidative stress. Therefore, our work prove that AKT2 plays an important role in the regulation of obesity-induced lipid metabolic disorder in the liver and heart. Our study also indicates AKT2 inhibitor as a potential therapy for obesity-induced hepatic and cardiac injury.


Assuntos
Dieta Hiperlipídica , Sirtuínas , Humanos , Animais , Camundongos , Ratos , Dieta Hiperlipídica/efeitos adversos , Fígado/metabolismo , Estresse Oxidativo , Obesidade/metabolismo , Miócitos Cardíacos/metabolismo , Sirtuínas/metabolismo , Lipídeos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Proto-Oncogênicas c-akt/metabolismo
18.
Fish Shellfish Immunol ; 143: 109215, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37951320

RESUMO

Marine lectins are a group of proteins that possess specific carbohydrate recognition and binding domains. They exhibit various activities, including antimicrobial, antitumor, antiviral, and immunomodulatory effects. In this study, a novel galectin-binding lectin gene named PFL-96 (GenBank: OQ561753.1) was cloned from Pinctada fucata. The PFL-96 gene has an open reading frame of 324 base pairs (bp) and encodes a protein comprising 107 amino acids. The protein has a molecular weight of 11.95 kDa and an isoelectric point of 9.27. It contains an N-terminal signal peptide and a galactose-binding lectin domain. The sequence identity to lectin proteins from fish, echinoderms, coelenterates, and shellfish ranges from 31.90 to 40.00 %. In the phylogenetic analysis, it was found that the PFL-96 protein is closely related to the lectin from Pteria penguin. The PFL-96 recombinant protein exhibited coagulation activity on 2 % rabbit red blood cells at a concentration of ≥8 µg/mL. Additionally, it showed significant hemolytic activity at a concentration of ≥32 µg/mL. The PFL-96 recombinant protein exhibited significant antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Candida albicans, and Vibrio alginolyticus, with minimum inhibitory concentrations (MIC) of 4, 8, 16, and 16 µg/mL, respectively. The minimum bactericidal concentrations (MBC) were determined to be 8, 16, 32, and 32 µg/mL, respectively. Furthermore, the PFL-96 recombinant protein exhibited inhibitory effects on the proliferation of Hela tumor cells, HepG2 tumor cells, and C666-1 tumor cells, with IC50 values of 7.962, 8.007, and 9.502 µg/mL, respectively. These findings suggest that the recombinant protein PFL-96 exhibits significant bioactivity in vitro, contributing to a better understanding of the active compounds found in P. fucata. The present study establishes a fundamental basis for further investigation into the mechanism of action and structural optimization of the recombinant protein PFL-96. The aim is to develop potential candidates for antibacterial and anti-tumor agents.


Assuntos
Pinctada , Animais , Coelhos , Pinctada/metabolismo , Sequência de Aminoácidos , Filogenia , Clonagem Molecular , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/metabolismo , Galectinas/genética , Galectinas/metabolismo , Antibacterianos/metabolismo
19.
Cell Biol Toxicol ; 39(4): 1489-1507, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-35798905

RESUMO

The sirtuin 6 (SIRT6) participates in regulating glucose and lipid homeostasis. However, the function of SIRT6 in the process of cardiac pathogenesis caused by obesity-associated lipotoxicity remains to be unveiled. This study was designed to elucidate the role of SIRT6 in the pathogenesis of cardiac injury due to nutrition overload-induced obesity and explore the downstream signaling pathways affecting oxidative stress in the heart. In this study, we used Sirt6 cardiac-specific knockout murine models treated with a high-fat diet (HFD) feeding to explore the function and mechanism of SIRT6 in the heart tissue during HFD-induced obesity. We also took advantage of neonatal cardiomyocytes to study the role and downstream molecules of SIRT6 during HFD-induced injury in vitro, in which intracellular oxidative stress and mitochondrial content were assessed. We observed that during HFD-induced obesity, Sirt6 loss-of-function aggravated cardiac injury including left ventricular hypertrophy and lipid accumulation. Our results evidenced that upon increased fatty acid uptake, SIRT6 positively regulated the expression of endonuclease G (ENDOG), which is a mitochondrial-resident molecule that plays an important role in mitochondrial biogenesis and redox homeostasis. Our results also showed that SIRT6 positively regulated superoxide dismutase 2 (SOD2) expression post-transcriptionally via ENDOG. Our study gives a new sight into SIRT6 beneficial role in mitochondrial biogenesis of cardiomyocytes. Our data also show that SIRT6 is required to reduce intracellular oxidative stress in the heart triggered by high-fat diet-induced obesity, involving the control of ENDOG/SOD2.


Assuntos
Estresse Oxidativo , Sirtuínas , Camundongos , Animais , Estresse Oxidativo/fisiologia , Sirtuínas/metabolismo , Obesidade/etiologia , Obesidade/metabolismo , Lipídeos
20.
Nanotechnology ; 35(9)2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38035384

RESUMO

HfO2-based ferroelectric field-effect transistors (FeFETs) are a promising candidate for multilevel memory manipulation and brain-like computing due to the multi-domain properties of the HfO2FE films based polycrystalline structure. Although there have been many reports on the working mechanism of the HfO2-based FeFET and improving its reliability, the impact of multi-domain effect on the effective carrier mobility (µchannel) has not been carried out yet. The effectiveµchanneldetermines the level of readout current and affects the accuracy of the precision of peripheral circuit. In this work, FeFETs with HfZrOxFE gate dielectric were fabricated, and the effect of write (or erase) pulses with linear gradient variation on the effectiveµchannelwas studied. For the multiple downward polarization under write pulses, theµchanneldegrades as the domains gradually switch to downward. This is mainly due to the enhancement of the scattering effect induced by the positive charges (e.g. oxygen vacanciesVO2+) trapping and the increase of channel carrier density. For the erase pulses, theµchannelincreases as the domains gradually reverse to upward, which is mainly due to the reduction of the scattering effect induced by the detrapping of positive charges and the decrease of channel carrier density. In addition, the modulation effect of multilevel polarization states onµchannelis verified by numerical simulation. This effect provides a new idea and solution for the development of low power HfO2-based FeFETs in neuromorphic computing.

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