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1.
Cell Mol Life Sci ; 81(1): 264, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38878214

RESUMO

Atrial fibrillation (AF) is the most common arrhythmia, and atrial fibrosis is a pathological hallmark of structural remodeling in AF. Prostaglandin I2 (PGI2) can prevent the process of fibrosis in various tissues via cell surface Prostaglandin I2 receptor (IP). However, the role of PGI2 in AF and atrial fibrosis remains unclear. The present study aimed to clarify the role of PGI2 in angiotensin II (Ang II)-induced AF and the underlying molecular mechanism. PGI2 content was decreased in both plasma and atrial tissue from patients with AF and mice treated with Ang II. Treatment with the PGI2 analog, iloprost, reduced Ang II-induced AF and atrial fibrosis. Iloprost prevented Ang II-induced atrial fibroblast collagen synthesis and differentiation. RNA-sequencing analysis revealed that iloprost significantly attenuated transcriptome changes in Ang II-treated atrial fibroblasts, especially mitogen-activated protein kinase (MAPK)-regulated genes. We demonstrated that iloprost elevated cAMP levels and then activated protein kinase A, resulting in a suppression of extracellular signal-regulated kinase1/2 and P38 activation, and ultimately inhibiting MAPK-dependent interleukin-6 transcription. In contrast, cardiac fibroblast-specific IP-knockdown mice had increased Ang II-induced AF inducibility and aggravated atrial fibrosis. Together, our study suggests that PGI2/IP system protects against atrial fibrosis and that PGI2 is a therapeutic target for treating AF.The prospectively registered trial was approved by the Chinese Clinical Trial Registry. The trial registration number is ChiCTR2200056733. Data of registration was 2022/02/12.


Assuntos
Angiotensina II , Fibrilação Atrial , Remodelamento Atrial , Epoprostenol , Camundongos Endogâmicos C57BL , Transdução de Sinais , Animais , Fibrilação Atrial/metabolismo , Fibrilação Atrial/patologia , Fibrilação Atrial/induzido quimicamente , Fibrilação Atrial/prevenção & controle , Camundongos , Humanos , Masculino , Transdução de Sinais/efeitos dos fármacos , Remodelamento Atrial/efeitos dos fármacos , Epoprostenol/metabolismo , Fibrose , Fibroblastos/metabolismo , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Átrios do Coração/metabolismo , Átrios do Coração/patologia , Átrios do Coração/efeitos dos fármacos , Iloprosta/farmacologia , Receptores de Epoprostenol/metabolismo , Receptores de Epoprostenol/genética , Feminino
2.
Circulation ; 147(19): 1444-1460, 2023 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-36987924

RESUMO

BACKGROUND: Myocardial ischemia-reperfusion (I/R) injury causes cardiac dysfunction to myocardial cell loss and fibrosis. Prevention of cell death is important to protect cardiac function after I/R injury. The process of reperfusion can lead to multiple types of cardiomyocyte death, including necrosis, apoptosis, autophagy, and ferroptosis. However, the time point at which the various modes of cell death occur after reperfusion injury and the mechanisms underlying ferroptosis regulation in cardiomyocytes are still unclear. METHODS: Using a left anterior descending coronary artery ligation mouse model, we sought to investigate the time point at which the various modes of cell death occur after reperfusion injury. To discover the key molecules involved in cardiomyocyte ferroptosis, we performed a metabolomics study. Loss/gain-of-function approaches were used to understand the role of 15-lipoxygenase (Alox15) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc1α) in myocardial I/R injury. RESULTS: We found that apoptosis and necrosis occurred in the early phase of I/R injury, and that ferroptosis was the predominant form of cell death during the prolonged reperfusion. Metabolomic profiling of eicosanoids revealed that Alox15 metabolites accumulated in ferroptotic cardiomyocytes. We demonstrated that Alox15 expression was specifically increased in the injured area of the left ventricle below the suture and colocalized with cardiomyocytes. Furthermore, myocardial-specific knockout of Alox15 in mice alleviated I/R injury and restored cardiac function. 15-Hydroperoxyeicosatetraenoic acid (15-HpETE), an intermediate metabolite derived from arachidonic acid by Alox15, was identified as a trigger for cardiomyocyte ferroptosis. We explored the mechanism underlying its effects and found that 15-HpETE promoted the binding of Pgc1α to the ubiquitin ligase ring finger protein 34, leading to its ubiquitin-dependent degradation. Consequently, attenuated mitochondrial biogenesis and abnormal mitochondrial morphology were observed. ML351, a specific inhibitor of Alox15, increased the protein level of Pgc1α, inhibited cardiomyocyte ferroptosis, protected the injured myocardium, and caused cardiac function recovery. CONCLUSIONS: Together, our results established that Alox15/15-HpETE-mediated cardiomyocyte ferroptosis plays an important role in prolonged I/R injury.


Assuntos
Araquidonato 15-Lipoxigenase , Ferroptose , Traumatismo por Reperfusão Miocárdica , Animais , Camundongos , Apoptose , Araquidonato 12-Lipoxigenase/metabolismo , Araquidonato 12-Lipoxigenase/farmacologia , Araquidonato 15-Lipoxigenase/genética , Araquidonato 15-Lipoxigenase/metabolismo , Araquidonato 15-Lipoxigenase/farmacologia , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/metabolismo , Miócitos Cardíacos/metabolismo , Necrose/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Ubiquitinas/metabolismo , Ubiquitinas/farmacologia
3.
Anal Chem ; 96(25): 10111-10115, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38869290

RESUMO

The Si window is the most widely used internal reflection element (IRE) for electrochemical attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), yet local chemical etching on Si by concentrated OH- anions bottlenecks the reliable application of this method in strong alkaline electrolytes. In this report, atomic layer deposition of a 25 nm nonconductive TiO2 barrier layer on the reflecting plane of a Si prism is demonstrated to address this challenge. In situ ATR-SEIRAS measurement on a Au film electrode with the Si/TiO2 composite IRE in 1 M NaOH reveals reversible global spectral features without spectral distortion at 1000-1300 cm-1, in stark contrast to those obtained with a bare Si window. By applying this structured ATR-SEIRAS, ethanol electrooxidation on a Pt/C catalyst in 1 and 5 M NaOH is explored, manifesting that such high pH values prevent the adsorption of as-formed acetate in the C2 pathway but not that of CO intermediate in the C1 pathway.

4.
Angew Chem Int Ed Engl ; 63(13): e202317740, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38318927

RESUMO

Plasmon-mediated electrocatalysis that rests on the ability of coupling localized surface plasmon resonance (LSPR) and electrochemical activation, emerges as an intriguing and booming area. However, its development seriously suffers from the entanglement between the photoelectronic and photothermal effects induced by the decay of plasmons, especially under the influence of applied potential. Herein, using LSPR-mediated CO2 reduction on Ag electrocatalyst as a model system, we quantitatively uncover the dominant photoelectronic effect on CO2 reduction reaction over a wide potential window, in contrast to the leading photothermal effect on H2 evolution reaction at relatively negative potentials. The excitation of LSPR selectively enhances the CO faradaic efficiency (17-fold at -0.6 VRHE ) and partial current density (100-fold at -0.6 VRHE ), suppressing the undesired H2 faradaic efficiency. Furthermore, in situ attenuated total reflection-surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) reveals a plasmon-promoted formation of the bridge-bonded CO on Ag surface via a carbonyl-containing C1 intermediate. The present work demonstrates a deep mechanistic understanding of selective regulation of interfacial reactions by coupling plasmons and electrochemistry.

6.
J Chem Phys ; 158(17)2023 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-37125721

RESUMO

A wide spectrum of state-of-the-art characterization techniques have been devised to monitor the electrode-electrolyte interface that dictates the performance of electrochemical devices. However, coupling multiple characterization techniques to realize in situ multidimensional analysis of electrochemical interfaces remains a challenge. Herein, we presented a hyphenated differential electrochemical mass spectrometry and attenuated total reflection surface enhanced infrared absorption spectroscopy analytical method via a specially designed electrochemical cell that enables a simultaneous detection of deposited and volatile interface species under electrochemical reaction conditions, especially suitable for non-aqueous, electrolyte-based energy devices. As a proof of concept, we demonstrated the capability of the homemade setup and obtained the valuable reaction mechanisms, by taking the tantalizing reactions in non-aqueous lithium-ion batteries (i.e., oxidation and reduction processes of carbonate-based electrolytes on Li1+xNi0.8Mn0.1Co0.1O2 and graphite surfaces) and lithium-oxygen batteries (i.e., reversibility of the oxygen reaction) as model reactions. Overall, we believe that the coupled and complementary techniques reported here will provide important insights into the interfacial electrochemistry of energy storage materials (i.e., in situ, multi-dimensional information in one single experiment) and generate much interest in the electrochemistry community and beyond.

7.
Anal Chem ; 94(32): 11337-11344, 2022 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-35930311

RESUMO

A balanced detection of both adsorbates and dissolved species is very important for the clarification of the electrochemical reaction mechanism yet remains a major challenge for different modes of electrochemical infrared (IR) spectroscopy. Among others, conventional attenuated total reflection-surface-enhanced IR absorption spectroscopy (ATR-SEIRAS) is far less sensitive to low-concentration solution species than to surface species. We report herein an electrochemical wide-frequency ATR-SEIRAS with a novel thin-layer flow cell design, fulfilling the simultaneous detection of the variations of surface and solution species. This setup consists of a silicon wafer (with one side micromachined and the other side metallized), a thin-layer electrolyte structure with tunable thickness and flow rate, and a tilt-correction system based on laser collimation, enabling a well-controlled mass transport within the electrolyte layer and the spectral differentiation of solution species from adsorbates. Using acidic methanol oxidation on a Pt film electrode as a model system, besides SEIRA bands for adsorbed CO and formate intermediates, IR spectral signals for dissolved products CO2, formic acid, and methyl formate can be readily identified for a quiescent electrolyte layer of ∼20 µm, which are otherwise undetected with conventional ATR-SEIRAS, as indicated by the trend of spectral features with increasing thickness or flow rate.


Assuntos
Eletrólitos , Eletroquímica , Eletrodos , Espectrofotometria Infravermelho/métodos , Propriedades de Superfície
8.
BMC Med Imaging ; 22(1): 85, 2022 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-35550032

RESUMO

BACKGROUND: Acoustic structure quantification (ASQ) has been applied to evaluate liver histologic changes by analyzing the speckle pattern seen on B-mode ultrasound. We aimed to assess the severity of portal hypertension (PHT) through hepatic ultrasonography. METHODS: Sixty patients diagnosed with PHT and underwent surgical treatment with portosystemic shunts were enrolled. Portal pressure (PP) was measured intraoperatively. Patients were divided into subgroups according to the severity of gastroesophageal varices and Child-Pugh class. Three difference ratio (Cm2) values on ASQ histogram mode were analyzed for their relationships with PP, degree of gastroesophageal varices and Child-Pugh liver function. Thirty healthy volunteers matched with the patients for gender and age were enrolled as controls. Comparisons among groups and correlation of the parameters with PP were analyzed. Area under the receive operating characteristic curve was used to evaluate the predicting value of ASQ parameters. RESULTS: In the patients, the ASQ parameters peak Cm2 (Cm2max), mean Cm2 (Cm2mean) and the highest occurred Cm2 value of the obtained red curve (RmaxCm2) were all greatly increased (P < 0.0001, P < 0.0001, P = 0.027). Multiple comparisons indicated that, regardless of Child-Pugh class and degree of gastroesophageal varices, the patients had significantly increased Cm2max and Cm2mean compared with the controls (all P < 0.0001). No differences among subgroups were observed. Cm2max was significantly statistically correlated with PP (r = 0.3505, P < 0.01), degree of varices (r = 0.4998, P < 0.0001). Youden's index for Cm2max with a cut-off value of 140.3 for predicting the presence of PHT, gastroesophageal varices and liver function equal to or worse than Child-Pugh class B were 0.8, 0.91 and 0.84, respectively. CONCLUSIONS: ASQ analysis of ultrasonographic images may have a role in the evaluation of the severity of PHT by detecting liver histologic changes in the speckle pattern caused by cirrhosis.


Assuntos
Varizes Esofágicas e Gástricas , Hipertensão Portal , Varizes , Acústica , Varizes Esofágicas e Gástricas/diagnóstico por imagem , Humanos , Hipertensão Portal/diagnóstico por imagem , Fígado/diagnóstico por imagem , Cirrose Hepática/diagnóstico por imagem
9.
Echocardiography ; 39(8): 1054-1063, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35781700

RESUMO

BACKGROUND: Carotid atherosclerosis by ultrasound scanning can be considered as an ideal window to reflect systemic artery atherosclerosis, which has aroused wide concern for predicting the severity of coronary artery atherosclerosis clinically. Ultrasound radio frequency (RF) data technology has enabled us to evaluate the carotid structure and elastic function precisely, for predicting the severity of coronary artery atherosclerosis. METHODS: Patients with suspected coronary artery disease (CAD) underwent coronary angiography and were assigned to four groups according to whether atherosclerotic plaque was found or not and it caused stenosis. Carotid artery intima-media thickness (IMT) and arterial stiffness were investigated by quality intima-media thickness (QIMT) and quality arterial stiffness (QAS) techniques during ultrasound scanning. Univariable and multivariable modeling were used to investigate correlations of carotid parameters to coronary artery atherosclerosis. Receive operating characteristic (ROC) curves were used to evaluate diagnostic performance of these ultrasound variables. RESULTS: Carotid IMT and stiffness variables pulse wave velocity (PWV), α, ß and compliance coefficient (CC) were statistically different between every two-group's comparisons. IMT correlated with stiffness variables significantly with r = 0.70, 0.77, 0.63, and -0.39, respectively. All variables correlated with the severity of coronary atherosclerosis with the odd ratio (OR) of 1.73, 1.67, 1.19, 1.23, and 0.56 accordingly as IMT, PWV, α, ß and CC were concerned. The AUC of IMT, PWV, α, ß and CC were 0.9257, 0.8910, 0.8016, 0.9383, 0.8581 with correctly classified rate of 88.16%, 83.77%, 78.07%, 86.84%, and 81.58%, respectively. CONCLUSIONS: Carotid artery IMT and stiffness variable PWV, α, ß and CC presented favorable predicting and differentiating values for patients with coronary atherosclerosis of different severity.


Assuntos
Aterosclerose , Doença da Artéria Coronariana , Artérias Carótidas , Espessura Intima-Media Carotídea , Humanos , Análise de Onda de Pulso
10.
Angew Chem Int Ed Engl ; 61(11): e202113362, 2022 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-34957665

RESUMO

Electro-reforming of renewable biomass resources is an alternative technology for sustainable pure H2 production. Herein, we discovered an unconventional cation effect on the concurrent formate and H2 production via glycerol electro-reforming. In stark contrast to the cation effect via forming double layers in cathodic reactions, residual cations at the anode were discovered to interact with the glycerol oxidation intermediates to steer its product selectivity. Through a combination of product analysis, transient kinetics, crown ether trapping experiments, in situ IRRAS and DFT calculations, the aldehyde intermediates were discovered to be stabilized by the Li+ cations to favor the non-oxidative C-C cleavage for formate production. The maximal formate efficiency could reach 81.3 % under ≈60 mA cm-2 in LiOH. This work emphasizes the significance of engineering the microenvironment at the electrode-electrolyte interface for efficient electrolytic processes.

11.
Clin Exp Pharmacol Physiol ; 47(7): 1134-1144, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32068900

RESUMO

Glycerophospholipids (GPs) and sphingolipids (SPs) are important lipid components in the body and play biological functions. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) are important nutrients, and their supplements are commonly used for preventing some diseases. However, the effect of n-3 PUFAs on the human glycerophospholipidome and sphingolipidome is unclear. We used targeted lipidomics to study the GP and SP profile of healthy individuals after supplementation with n-3 PUFAs for 3, 7, 14 and 21 days. Fuzzy c-means clustering was used to cluster the lipid species into six classes reflecting different changed-content patterns after n-3 PUFA supplementation. Among the species with significantly changed content, lysophospholipids were the most sensitive; their content started to increase on day 3. The content of phosphatidylserines increased at a later stage. The content of most of the phosphatidylcholines and alkylphosphatidylcholines decreased on day 21. A correlation network analysis of lipid species suggested that some enzymes involved in the metabolism of lysophospholipids and phosphatidylserines were regulated by n-3 PUFAs. Levels of creatine kinase-MB (CK-MB), urea, glucose, triglycerides and total bilirubin were altered by n-3 PUFA at 21 days. Correlation analysis revealed that the level of CK-MB was negatively correlated with those of species in lysophosphatidic acid, lysophosphatidylcholine, lysophosphatidylethanolamine and phosphatidylserine classes, which were increased by n-3 PUFA supplementation. With the analysis in this work, we demonstrated the regular pattern of n-3 PUFAs on GP and SP metabolism, which provides a pharmacological basis for n-3 PUFAs for clinical application.


Assuntos
Suplementos Nutricionais/análise , Ácidos Graxos Ômega-3/farmacologia , Lipidômica , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino
12.
Angew Chem Int Ed Engl ; 59(50): 22397-22402, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-32893447

RESUMO

Driven by the persisting poor understanding of the sluggish kinetics of the hydrogen evolution reaction (HER) on Pt in alkaline media, a direct correlation of the interfacial water structure and activity is still yet to be established. Herein, using Pt and Pt-Ni nanoparticles we first demonstrate a strong dependence of the proton donor structure on the HER activity and pH. The structure of the first layer changes from the proton acceptors to the donors with increasing pH. In the base, the reactivity of the interfacial water varied its structure, and the activation energies of water dissociation increased in the sequence: the dangling O-H bonds < the trihedrally coordinated water < the tetrahedrally coordinated water. Moreover, optimizing the adsorption of H and OH intermediates can re-orientate the interfacial water molecules with their H atoms pointing towards the electrode surface, thereby enhancing the kinetics of HER. Our results clarified the dynamic role of the water structure at the electrode-electrolyte interface during HER and the design of highly efficient HER catalysts.

13.
J Am Chem Soc ; 141(51): 20451-20459, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31790227

RESUMO

Oxygen-containing groups on carbon materials can induce high catalytic activity for some reactions. Herein, on the basis of a series of metal-free single-layer graphene nanodisks (GNDs) with different surface contents of oxygen-containing groups for highly efficient electrocatalytic reduction reaction of CO2 (CO2RR) to produce formate (HCOO-), we find that the CO2RR catalytic performance is only positively correlated with the surface content of carboxyl groups. While significantly, the density functional theory calculations demonstrate that the observed high CO2RR catalytic activity originates not from the solo carboxyl or other oxygen-containing groups, but from the synergistic effect between carboxyl groups and adjacent other types of groups (namely, hydroxyl, epoxide, and carbonyl) on GNDs. Inspired by such new knowledge, we further find that if the GND catalyst can "alternate work with rest", its electrocatalytic activity for CO2RR can be regenerated cyclically via a simple electro-oxidation method to regenerate the surface carboxyl groups, achieving a remarkable long-term durability for CO2RR. Such work deepens our understanding of the role of oxygen-containing groups in catalysis and provides a new strategy for the design and synthesis of high-performance metal-free carbon-based catalysts.

14.
Am J Physiol Gastrointest Liver Physiol ; 316(4): G527-G538, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30789748

RESUMO

Hepatic steatosis is the beginning phase of nonalcoholic fatty liver disease, and hyperhomocysteinemia (HHcy) is a significant risk factor. Soluble epoxide hydrolase (sEH) hydrolyzes epoxyeicosatrienoic acids (EETs) and other epoxy fatty acids, attenuating their cardiovascular protective effects. However, the involvement of sEH in HHcy-induced hepatic steatosis is unknown. The current study aimed to explore the role of sEH in HHcy-induced lipid disorder. We fed 6-wk-old male mice a chow diet or 2% (wt/wt) high-metnionine diet for 8 wk to establish the HHcy model. A high level of homocysteine induced lipid accumulation in vivo and in vitro, which was concomitant with the increased activity and expression of sEH. Treatment with a highly selective specific sEH inhibitor (0.8 mg·kg-1·day-1 for the animal model and 1 µM for cells) prevented HHcy-induced lipid accumulation in vivo and in vitro. Inhibition of sEH activated the peroxisome proliferator-activated receptor-α (PPAR-α), as evidenced by elevated ß-oxidation of fatty acids and the expression of PPAR-α target genes in HHcy-induced hepatic steatosis. In primary cultured hepatocytes, the effect of sEH inhibition on PPAR-α activation was further confirmed by a marked increase in PPAR-response element luciferase activity, which was reversed by knock down of PPAR-α. Of note, 11,12-EET ligand dependently activated PPAR-α. Thus increased sEH activity is a key determinant in the pathogenesis of HHcy-induced hepatic steatosis, and sEH inhibition could be an effective treatment for HHcy-induced hepatic steatosis. NEW & NOTEWORTHY In the current study, we demonstrated that upregulation of soluble epoxide hydrolase (sEH) is involved in the hyperhomocysteinemia (HHcy)-caused hepatic steatosis in an HHcy mouse model and in murine primary hepatocytes. Improving hepatic steatosis in HHcy mice by pharmacological inhibition of sEH to activate peroxisome proliferator-activated receptor-α was ligand dependent, and sEH could be a potential therapeutic target for the treatment of nonalcoholic fatty liver disease.


Assuntos
Inibidores Enzimáticos/farmacocinética , Epóxido Hidrolases , Ácidos Graxos/metabolismo , Fígado Gorduroso , Hiper-Homocisteinemia , PPAR alfa/metabolismo , Animais , Modelos Animais de Doenças , Descoberta de Drogas , Epóxido Hidrolases/antagonistas & inibidores , Epóxido Hidrolases/metabolismo , Fígado Gorduroso/tratamento farmacológico , Fígado Gorduroso/enzimologia , Fígado Gorduroso/etiologia , Fígado Gorduroso/metabolismo , Hiper-Homocisteinemia/complicações , Hiper-Homocisteinemia/metabolismo , Ligantes , Camundongos , Camundongos Endogâmicos C57BL , Regulação para Cima
15.
Anal Chem ; 91(16): 10541-10548, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31313574

RESUMO

The photothermally induced resonance AFM-IR technique (denoted as PTIR) is a promising and still developing analytical method that can provide nanoscale chemical and topographical information. Herein, by taking advantage of a customized PTIR system with either top-down or bottom-up incidence mode for a quantum cascade laser (QCL), we explore how the surface-enhanced IR absorption (SEIRA) effect due to the Au-coated AFM tip and/or substrate may affect the PTIR signals from 25 to 580 nm thick p-nitrobenzoic acid (PNBA) samples, as a function of sample thickness, incidence mode, laser polarization, and Au film morphology. By analysis of the νas(NO2) band intensity, it is revealed that the SEIRA effect may increase the PTIR signals by 1.5-8.3 times, with that from the Au-coated substrate being greater than that from the Au-coated tip. Nevertheless, the overall PTIR signal goes up monotonically over the entire thickness range for the top-down incidence mode, while it increases and then decreases with the sample thickness for the bottom-up incidence mode. The p-polarized laser enhances the PTIR signal more than does the s-polarized laser, especially on the Au-coated substrate. The significant loss of the PTIR signal of a PNBA sample corroborates the substantial loss of the SEIRA effect of an annealed Au film. The present work may promote the application of the SEIRA effect to the PTIR technique and provides hints for developing the PTIR technique into a more versatile analytical tool.

16.
Clin Exp Pharmacol Physiol ; 46(8): 705-710, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30983029

RESUMO

Pre-eclampsia (PE) is considered a leading cause of mortality and morbidity in pregnant women worldwide. Eicosanoids derived from polyunsaturated fatty acids (PUFAs) might play an important role in the occurrence and development of PE. Omega-3 PUFAs are nutrients that are popular supplements for pregnant women and can reduce blood pressure. However, the levels of eicosanoids derived from omega-3 PUFAs in women with PE is not clear. The purpose of this study was to investigate the eicosanoid metabolic signature of PE. We performed a case-control study using data for pregnant women (n = 10) with PE and normotensive pregnant women (n = 10). We investigated the difference in eicosanoid profile between the groups by LC-MS/MS-based metabolomics. The plasma levels of arachidonic acid metabolites and some of the lipoxygenase metabolites of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) showed an increasing trend, and those of the cytochrome P450 metabolites of EPA and DHA were decreased in women with PE. Levels of leukotriene B4, 14,15-dihydroxy-eicosatetraenoate, 16-hydroxydocosahexaenoic acid and 8,9-epoxy eicosatetraenoic acid were significantly correlated with PE occurrence. These eicosanoids might take part in the progression of PE in pregnant women.


Assuntos
Eicosanoides/metabolismo , Ácidos Graxos Ômega-3/metabolismo , Metabolômica , Pré-Eclâmpsia/metabolismo , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Gravidez , Adulto Jovem
17.
J Am Chem Soc ; 140(8): 2880-2889, 2018 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-29409320

RESUMO

Facile interconversion between CO2 and formate/formic acid (FA) is of broad interest in energy storage and conversion and neutral carbon emission. Historically, electrochemical CO2 reduction reaction to formate on Pd surfaces was limited to a narrow potential range positive of -0.25 V (vs RHE). Herein, a boron-doped Pd catalyst (Pd-B/C), with a high CO tolerance to facilitate dehydrogenation of FA/formate to CO2, is initially explored for electrochemical CO2 reduction over the potential range of -0.2 V to -1.0 V (vs RHE), with reference to Pd/C. The experimental results demonstrate that the faradaic efficiency for formate (ηHCOO-) reaches ca. 70% over 2 h of electrolysis in CO2-saturated 0.1 M KHCO3 at -0.5 V (vs RHE) on Pd-B/C, that is ca. 12 times as high as that on homemade or commercial Pd/C, leading to a formate concentration of ca. 234 mM mg-1 Pd, or ca. 18 times as high as that on Pd/C, without optimization of the catalyst layer and the electrolyte. Furthermore, the competitive selectivity ηHCOO-/ηCO on Pd-B/C is always significantly higher than that on Pd/C despite a decreases of ηHCOO- and an increases of the CO faradaic efficiency (ηCO) at potentials negative of -0.5 V. The density functional theory (DFT) calculations on energetic aspects of CO2 reduction reaction on modeled Pd(111) surfaces with and without H-adsorbate reveal that the B-doping in the Pd subsurface favors the formation of the adsorbed HCOO*, an intermediate for the FA pathway, more than that of *COOH, an intermediate for the CO pathway. The present study confers Pd-B/C a unique dual functional catalyst for the HCOOH ↔ CO2 interconversion.

18.
Artigo em Inglês | MEDLINE | ID: mdl-30223037

RESUMO

Omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation is a recommended preventive approach against cardiovascular diseases, but its mechanism of protection against myocardial infarction (MI) injury is not fully understood. Eicosanoid metabolomics demonstrated an abnormal eicosanoid profile was in the plasma of mice receiving MI surgery. 19,20-EDP, 17,18-EEQ, 14,15-EET and 9,10-EpOME were decreased, and PGE2 was increased by the surgery. N-3 PUFA-rich diets feeding or transgene of Fat-1 shifted the eicosanoid profile to an n-3 PUFA dominant style and attenuated the myocardial infarction injury. Multiple logistic regression analysis suggested the degree of MI injury was related with an eicosanoid pattern, composed by eicosanoids derived from both n-3 and n-6 PUFA in the three enzymatic pathways. These results suggested the benefits of n-3 PUFA on MI was achieved synergistically.


Assuntos
Eicosanoides/uso terapêutico , Ácidos Graxos Ômega-3/uso terapêutico , Traumatismos Cardíacos/dietoterapia , Infarto do Miocárdio/dietoterapia , Animais , Dieta , Eicosanoides/metabolismo , Traumatismos Cardíacos/metabolismo , Traumatismos Cardíacos/patologia , Humanos , Modelos Logísticos , Camundongos , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/fisiopatologia
19.
J Am Chem Soc ; 139(44): 15664-15667, 2017 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-29058890

RESUMO

Cu is the only monometallic catalyst that produces a large amount of hydrocarbon fuels during the CO2 electrochemical reduction reaction (CO2RR). However, the CO2RR mechanism and the impact of electrolyte are unclear. In this communication, two important issues regarding the CO2RR on Cu surfaces are studied: (1) the direct observation on reaction intermediates and (2) the role of the electrolyte (KHCO3) in the reaction. Surface-enhanced infrared absorption spectroscopy allows direct observation of several reaction intermediates that have never been detected before, except for the commonly detected CO. Another important finding is that CO2 molecules are mediated to the Cu surface via their equilibrium with bicarbonate anions instead of direct adsorption from the solution. These results shed light on the full understanding of the CO2RR on Cu surfaces and developing more advanced catalysts.

20.
Biochem Biophys Res Commun ; 483(1): 602-608, 2017 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-27998767

RESUMO

Maternal diabetes mellitus induces an increased risk of congenital heart defects (CHD), however, the exact mechanisms are still not fully illustrated. In this study, diabetic pregnant C57BL/6 mice were induced by injection of streptozotocin before mating. Compared with the control normal mice, diabetic pregnant mice displayed significant changes of the exosomal miRNA contents in the blood, as revealed by RNA-seq analysis. Multiple of these miRNAs were found involved in cardiac development regulation. Moreover, fluorescence labeled exosomes and gold nanoparticles could cross the placenta barrier and infiltrated into the embryonic organs/tissues, including the heart, during embryonic development. Injection of diabetic maternal exosomes strikingly increased the risk of CHD in the normal recipient pregnant mice. Taken together, we could draw the conclusion that maternal exosomes in diabetes could cross the maternal-fetal barrier and contribute to the cardiac development deficiency possibly via miRNAs, providing new insights in CHD prevention and treatment.


Assuntos
Complicações do Diabetes/metabolismo , Exossomos/metabolismo , Cardiopatias Congênitas/complicações , Coração/embriologia , Miocárdio/metabolismo , Animais , Diabetes Mellitus Experimental/metabolismo , Ecocardiografia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Placenta/metabolismo , Gravidez
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