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1.
Anal Chem ; 95(2): 1635-1642, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36533710

RESUMO

Four-photon absorption (4PA) multimodal therapeutic agent applied to tumor ferroptosis process tracking is rarely reported. In this paper, two functionalized terpyridine iron complexes (TD-FeCl3, TD-Fe-TD) with four-photon absorption properties were designed and synthesized. The four-photon absorption cross sections of TD-FeCl3 reached 6.87 × 10-74cm8·s3·photon-3. Due to its strong near-infrared absorption, TD-FeCl3 has excellent photoacoustic imaging (PAI) capability for accurate PA imaging. TD-FeCl3 has an efficient longitudinal electron relaxation rate (r1 = 2.26 mM-1 s-1) and high spatial resolution, which can be applied as T1-weighted magnetic resonance imaging (MRI) contrast agent for tumor imaging in vivo. In addition, Fe3+ as a natural ferroptosis tracer, TD-FeCl3, is able to deplete glutathione (GSH) effectively, which can further enhance the ferroptosis process. We found that the series of cheap transition metal complexes has four-photon absorption activity and can be used as multimodal (MRI/PAI) diagnostic agents for tumor tracing processes.


Assuntos
Ferroptose , Nanopartículas , Neoplasias , Humanos , Nanopartículas/uso terapêutico , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética , Meios de Contraste , Ferro
2.
Clin Endocrinol (Oxf) ; 98(2): 212-220, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36237121

RESUMO

OBJECTIVES: Observational studies suggest birth weight and childhood obesity are closely associated with age at menarche. However, the relationships between them are currently inconsistent and it remains elusive whether such associations are causal. Therefore, the aim of the study was to investigate whether there existed causal relationships between birth weight, childhood obesity and age at menarche. DESIGN, PATIENTS AND MEASUREMENTS: A two-sample Mendelian randomization (MR) study. The standard inverse variance weighted MR analyses were adopted to evaluate the causal effects of birth weight (n = 143,677), childhood body mass index (BMI) (n = 39,620) on age at menarche (n = 182,416) with summary statistics from large-scale genome-wide association studies (GWASs). Meanwhile, we validated our MR results with some sensitivity analyses including maximum likelihood, weighted-median and MR pleiotropy residual sum and outlier methods. RESULTS: The present study showed that each one standard deviation (1-SD) lower birth weight was predicted to result in a 0.1479 years earlier of age at menarche (ß = .1479, 95% confidence interval [CI] = 0.0422-0.2535; p = 0.0061). We also found that genetically predicted 1-SD increase in childhood BMI was causally associated with early age at menarche (ß = -.3966, 95% CI = -0.5294 to -0.2639; p = 4.73E-09). CONCLUSIONS: Our MR study suggests the causal effect of lower birth weight and higher childhood BMI on the increased risk of earlier menarche. It may be the opportune time to carry out weight control intervention in prenatal and early childhood development periods to prevent early menarche onset, thus decreasing the future adverse consequences.


Assuntos
Obesidade Infantil , Pré-Escolar , Feminino , Gravidez , Humanos , Criança , Obesidade Infantil/genética , Menarca/genética , Análise da Randomização Mendeliana , Peso ao Nascer , Estudo de Associação Genômica Ampla , Índice de Massa Corporal , Polimorfismo de Nucleotídeo Único
3.
Br J Nutr ; 130(9): 1645-1656, 2023 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-36938807

RESUMO

Animal studies have shown that capsaicin plays a positive role in weight management. However, the results in human research are controversial. Therefore, the present systematic review and meta-analysis aimed to evaluate the effect of capsaicin on weight loss in adults. We searched PubMed, Embase, China Biomedical Literature Database (CBM), Cochrane library and clinical registration centre, identifying all randomised controlled trials (RCT) published in English and Chinese to 3 May 2022. A random-effect model was used to calculate the weighted mean difference (WMD) and 95 % CI. Heterogeneity between studies was assessed by the Cochran Q statistic and I-squared tests (I 2 ). Statistical analyses were performed using STATA version 15.1. P-values < 0·05 were considered as statistically significant. From 2377 retrieved studies, fifteen studies were finally included in the meta-analyses. Fifteen RCT with 762 individuals were included in our meta-analysis. Compared with the control group, the supplementation of capsaicin resulted in significant reduction on BMI (WMD: -0·25 kg/m2, 95 % CI = -0·35, -0·15 kg/m2, P < 0·05), body weight (BW) (WMD: -0·51 kg, 95 % CI = -0·86, -0·15 kg, P < 0·05) and waist circumference (WC) (WMD: -1·12 cm, 95 % CI = -2·00, -0·24 cm, P < 0·05). We found no detrimental effect of capsaicin on waist-to-hip ratio (WMD: -0·05, 95 % CI = -0·17, 0·06, P > 0·05). The current meta-analysis suggests that capsaicin supplementation may have rather modest effects in reducing BMI, BW and WC for overweight or obese individuals.


Assuntos
Capsaicina , Sobrepeso , Adulto , Humanos , Capsaicina/farmacologia , Capsaicina/uso terapêutico , Suplementos Nutricionais , Obesidade , Peso Corporal , Redução de Peso , Ensaios Clínicos Controlados Aleatórios como Assunto
4.
Thromb J ; 21(1): 41, 2023 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-37069620

RESUMO

BACKGROUND: Blood transfusion and previous stroke history are two independent risk factors of venous thromboembolism (VTE) in stroke patients. Whether the potential interaction of transfusion history and previous stroke history is associated with a greater risk of VTE remains unclear. This study aims to explore whether the combination of transfusion history and previous stroke history increases the risk of VTE among Chinese stroke patients. METHODS: A total of 1525 participants from the prospective Stroke Cohort of Henan Province were enrolled in our study. Multivariate logistic regression models were used to explore the associations among transfusion history, previous stroke history and VTE. The interaction was evaluated on both multiplicative and additive scales. The odds ratio (95% CI), relative excess risk of interaction (RERI), attributable proportion (AP), and synergy index (S) of interaction terms were used to examine multiplicative and additive interactions. Finally, we divided our population into two subgroups by National Institutes of Health Stroke Scale (NIHSS) score and re-evaluated the interaction effect in both scales. RESULTS: A total of 281 (18.4%) participants of 1525 complicated with VTE. Transfusion and previous stroke history were associated with an increased risk of VTE in our cohort. In the multiplicative scale, the combination of transfusion and previous stroke history was statistically significant on VTE in both unadjusted and adjusted models (P<0.05). For the additive scale, the RERI shrank to 7.016 (95% CI: 1.489 ~ 18.165), with the AP of 0.650 (95% CI: 0.204 ~ 0.797) and the S of 3.529 (95% CI: 1.415 ~ 8.579) after adjusting for covariates, indicating a supra-additive effect. In subgroups, the interaction effect between transfusion history and previous stroke history was pronouncedly associated with the increased risk of VTE in patients with NIHSS score > 5 points (P<0.05). CONCLUSIONS: Our results suggest that there may be a potential synergistic interaction between transfusion history and previous stroke history on the risk of VTE. Besides, the percentage of VTE incidence explained by interaction increased with the severity of stroke. Our findings will provide valuable evidence for thromboprophylaxis in Chinese stroke patients.

5.
Anal Chem ; 94(39): 13396-13403, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36136967

RESUMO

Intracellular lipid storage and regulation occur in lipid droplets, which are of great significance to the physiological activities of cells. Herein, a lipid droplet-specific fluorescence probe (lip-YB) with a high quantum yield (QYlip-YB = 73.28%), excellent photostability, and quickly polarity sensitivity was constructed successfully. Interestingly, lip-YB exhibited remarkable two-photon (TP) characteristics, which first realized real-time monitoring of the lipid droplet multidynamics process, diagnosing nonalcoholic fatty liver disease (NAFLD) and inflammation in living mice via TP fluorescence imaging. It is found that the as-prepared lip-YB provides a new avenue to design lipid droplet-specific imaging probes, clarifies its roles and mechanisms in cell metabolism, and can timely intervene in lipid droplet-related diseases during various physiological and pathological processes.


Assuntos
Gotículas Lipídicas , Hepatopatia Gordurosa não Alcoólica , Animais , Corantes Fluorescentes/metabolismo , Inflamação/diagnóstico por imagem , Inflamação/metabolismo , Gotículas Lipídicas/metabolismo , Lipídeos , Camundongos , Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem , Hepatopatia Gordurosa não Alcoólica/metabolismo
6.
Anal Chem ; 94(23): 8373-8381, 2022 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-35647787

RESUMO

Various suborganelles are delimited by lipid bilayers, in which high spatial and temporal morphological changes are essential to many physiological and pathological processes of cells. However, almost all the amphiphilic fluorescent molecules reported until now are not available for in situ precise tracking of membrane dynamics in cell apoptosis. Here, the MO (coumarin pyridine derivatives) was devised by engineering lipophilic coumarin and cationic pyridine salt, which not only lastingly anchored onto the plasma membrane in dark due to appropriate amphipathicity and electrostatic interactions but also in situ reflected the membrane damage and heterogeneity with secretion of extracellular vesicles (EVs) under reactive oxygen species regulation and was investigated by two-photon fluorescence lifetime imaging microscopy. This work opens up a new avenue for the development of plasma membrane staining and EV-based medicines for the early diagnosis and treatment of disease.


Assuntos
Corantes Fluorescentes , Neoplasias , Membrana Celular/metabolismo , Cumarínicos/metabolismo , Corantes Fluorescentes/metabolismo , Humanos , Microscopia de Fluorescência , Neoplasias/metabolismo , Imagem Óptica , Piridinas/metabolismo
7.
Inorg Chem ; 61(32): 12652-12661, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35921656

RESUMO

The synergy of multiphoton fluorescence imaging (MP-FI) and magnetic resonance imaging (MRI) provides an imaging platform with high resolution and unlimited penetration depth for early disease detection. Herein, two kinds of terpyridine-Mn(II) complexes (FD-Mn-O2NO and FD-Mn-FD) possessing seven and six coordination modes, respectively, were designed rationally for photodynamic therapy (PDT) guided by MP-FI/MRI. The complexes obtain different multiphoton fluorescence/magnetic resonance properties by adjusting the number of terpyridine ligands. Among them, FD-Mn-FD exhibits the following superiorities: (1) The optimal three-photon excitation wavelength of FD-Mn-FD falls at 1450 nm (NIR-II), which brings high sensitivity and deep tissue penetration in MP-FI. (2) FD-Mn-FD has effective longitudinal relaxation efficiency (r1 = 2.6 m M-1 s-1), which can be used for T1-weighted MRI, overcoming the problems of limited tissue penetration depth and low spatial resolution. (3) FD-Mn-FD generates endogenous 1O2 under irradiation by 808 nm light, thereby enhancing the PDT effect in vitro and in vivo. To the best of our knowledge, the complex FD-Mn-FD is the first complex to guide PDT through MP-FI/MRI, providing a blueprint for accurate and effective early detection and timely treatment of the complex in the early stages of cancer.


Assuntos
Neoplasias , Fotoquimioterapia , Humanos , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Neoplasias/tratamento farmacológico , Fótons , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico
8.
Anal Chem ; 93(35): 12059-12066, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34433261

RESUMO

Considering the multiple biological barriers before the entry of photosensitizers (PSs) into cytoplasm, it is of paramount importance to track PSs to elucidate their behaviors and distributions to guide the photodynamic therapy (PDT). Also, the developed PSs suffer from strong oxygen dependency. However, reports on such ideal theranostic platforms are rare. Herein, we developed a theranostic platform (CMTP-2) based on the coumarin-based D-π-A system, which, for the first time, can reveal the holistic intracellular delivery pathway and near-infrared (NIR)-activated mitophagy to guide synergistic type-I PDT and photothermal therapy. The dynamic endo-lysosomal escape of CMTP-2 was monitored, as well as its changeable distributions in endosomes, lysosomes, and mitochondria, demonstrating the preferential accumulation in mitochondria at the end. Upon NIR-I irradiation, CMTP-2 generated toxic radicals and heat, triggering the execution of mitophagy and apoptosis. In vivo experiments on mice indicated that CMTP-2 under 808 nm irradiation realized complete cancer ablation, showing great potential for advancements in synergistic phototherapy.


Assuntos
Mitofagia , Fotoquimioterapia , Animais , Linhagem Celular Tumoral , Lisossomos , Camundongos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Fototerapia , Terapia Fototérmica
9.
Anal Chem ; 92(15): 10815-10821, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32615754

RESUMO

Cell viability is greatly affected by external stimulus eliciting correlated dynamical physiological processes for cells to choose survival or death. A few fluorescent probes have been designed to detect whether the cell is in survival state or apoptotic state, but monitoring the regulation process of the cell undergoing survival to death remains a long-standing challenge. Herein, we highlight the in situ monitor of mitochondria regulating the cell viability by the RNA-specific fluorescent photosensitizer L. At normal conditions, L anchored mitochondria and interacted with mito-RNA to light up the mitochondria with red fluorescence. With external light stimulus, L generated reactive oxide species (ROS) and cause damage to mitochondria, which activated mitochondrial autophagy to prevent death, during which the red fluorescence of L witnessed dynamical distribution in accordance with the evolution of vacuole structures containing damaged mitochondria into autophagosomes. However, with ROS continuously increasing, the mitochondrial apoptosis was eventually commenced and L with red fluorescent was gradually accumulated in the nucleoli, indicating the programmed cell death. This work demonstrated how the delicate balance between survival and death are regulated by mitochondria.


Assuntos
Mitocôndrias/metabolismo , Fármacos Fotossensibilizantes/farmacologia , RNA/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Núcleo Celular/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Células HeLa , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/efeitos da radiação , Modelos Moleculares , Conformação Molecular , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo
10.
Mol Genet Genomics ; 295(2): 439-451, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31813042

RESUMO

Stroke is a complex disease with multiple etiologies. Numerous studies suggest an established association between obesity and stroke, which may partly arise from the shared genetic components between the two phenotypes. Despite genome-wide association studies (GWASs) have identified some loci associated with stroke and obesity individually, the estimated genetic variability explained by these loci is limited (especially for stroke) and the pleiotropic loci between them are largely unknown. In this study, we jointly applied the pleiotropy-informed conditional false discovery rate (cFDR) method and the genetic analysis incorporating pleiotropy and annotation (GPA) method on summary statistics of two large GWASs to detect the genetic overlap between stroke (n = 446,696) and obesity (n = 681,275). Stratified Q-Q and fold-enrichment plots showed strong pleiotropic enrichment between the two phenotypes. With cFDR < 0.05 and fdr.GPA < 0.2, we identified 24 (16 novel) stroke-associated SNPs and 12 (10 novel) of them to be potentially pleiotropic SNPs for both phenotypes. The corresponding genes were enriched in trait-associated gene ontology (GO) terms "brain development" and "negative regulation of transport". In conclusion, our study demonstrated the feasibility and effectivity of the two pleiotropic methods which successfully improved the genetic discovery by incorporating related GWAS datasets and validated the genetic intercommunity between stroke and obesity. The identification of pleiotropic loci may provide us any new insights into potential genetic and etiology mechanism between them for the further studies.


Assuntos
Pleiotropia Genética/genética , Predisposição Genética para Doença , Obesidade/genética , Acidente Vascular Cerebral/genética , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Redes Reguladoras de Genes/genética , Estudo de Associação Genômica Ampla , Humanos , Obesidade/patologia , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Acidente Vascular Cerebral/patologia
11.
Inorg Chem ; 59(5): 3249-3259, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32057236

RESUMO

Iron centers featuring thiolates in their metal coordination sphere (as ligands or substrates) are well-known to activate dioxygen. Both heme and non-heme centers that contain iron-thiolate bonds are found in nature. Investigating the ability of iron-thiolate model complexes to activate O2 is expected to improve the understanding of the key factors that direct reactivity to either iron or sulfur. We report here the structural and redox properties of a thiolate-based dinuclear Fe complex, [FeII2(LS)2] (LS2- = 2,2'-(2,2'-bipyridine-6,6'-iyl)bis(1,1-diphenylethanethiolate)), and its reactivity with dioxygen, in comparison with its previously reported protonated counterpart, [FeII2(LS)(LSH)]+. When reaction with O2 occurs in the absence of protons or in the presence of 1 equiv of proton (i.e., from [FeII2(LS)(LSH)]+), unsupported µ-oxo or µ-hydroxo FeIII dinuclear complexes ([FeIII2(LS)2O] and [FeIII2(LS)2(OH)]+, respectively) are generated. [FeIII2(LS)2O], reported previously but isolated here for the first time from O2 activation, is characterized by single crystal X-ray diffraction and Mössbauer, resonance Raman, and NMR spectroscopies. The addition of protons leads to the release of water and the generation of a mixture of two Fe-based "oxygen-free" species. Density functional theory calculations provide insight into the formation of the µ-oxo or µ-hydroxo FeIII dimers, suggesting that a dinuclear µ-peroxo FeIII intermediate is key to reactivity, and the structure of which changes as a function of protonation state. Compared to previously reported Mn-thiolate analogues, the evolution of the peroxo intermediates to the final products is different and involves a comproportionation vs a dismutation process for the Mn and Fe derivate, respectively.

12.
Int J Equity Health ; 19(1): 6, 2020 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-31906960

RESUMO

BACKGROUND: Aging and the chronic non-communicable diseases (NCDs) challenge the Chinese government in the process of providing hospitalization services fairly and reasonably. The Chinese government has developed the basic medical insurance system to solve the problem of "expensive medical cost and difficult medical services" for vulnerable groups and alleviate the unfair phenomenon. However, few studies have confirmed its effect through longitudinal comparison. This study aimed to explore the trend in the inequity of inpatient use among middle-aged and elderly individuals with NCDs in China. METHODS: This longitudinal comparative study was based on CHARLS data in 2011, 2013 and 2015. Concentration index (CI) was used to measure the variation trend of inequity of inpatient services utilization, while the decomposition method of the CI was applied to measure the factors contributing to inequity in inpatient services utilization. The effect of each factor on the change of inequity in inpatient services utilization was divided into the change of the elasticity and the change of inequality using the Oaxaca-type decomposition method. RESULTS: The affluent middle-aged and elderly patients with NCDs used more inpatient services than poor groups. The per capita household consumption expenditure (PCE) and Urban Employee Basic Medical Insurance (UEBMI) contributed to the decline in pro-rich inequality of inpatient use, while the New Rural Cooperative Medical Scheme (NRCMS) contributed to the decline in pro-poor inequality of inpatient use. CONCLUSIONS: There was a certain degree of pro-rich unfairness in the probability and frequency of inpatient services utilization for middle-aged and elderly individuals with NCDs in China. The decrease of pro-wealth contribution of PCE and UEBMI offset the decrease of pro-poor contribution of NRCMS, and improved the equity of inpatient services utilization, favoring poor people.


Assuntos
Utilização de Instalações e Serviços/estatística & dados numéricos , Disparidades em Assistência à Saúde/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Doenças não Transmissíveis/terapia , Idoso , China , Doença Crônica , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fatores Socioeconômicos
13.
J Am Chem Soc ; 141(20): 8244-8253, 2019 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-31026148

RESUMO

In the oxygen reduction reaction (ORR) domain, the investigation of new homogeneous catalysts is a crucial step toward the full comprehension of the key structural and/or electronic factors that control catalytic efficiency and selectivity. Herein, we report a unique non-heme diiron complex that can act as a homogeneous ORR catalyst in acetonitrile solution. This iron(II) thiolate dinuclear complex, [FeII2(LS)(LSH)] ([Fe2SH]+) (LS2- = 2,2'-(2,2'-bipyridine-6,6'-diyl)bis(1,1-diphenylethanethiolate)) contains a thiol group in the metal coordination sphere. [Fe2SH]+ is an efficient ORR catalyst both in the presence of a one-electron reducing agent and under electrochemically assisted conditions. However, its selectivity is dependent on the electron delivery pathway; in particular, the process is selective for H2O2 production under chemical conditions (up to ∼95%), whereas H2O is the main product during electrocatalysis (less than ∼10% H2O2). Based on computational work alongside the experimental data, a mechanistic proposal is discussed that rationalizes the selective and tunable reduction of dioxygen.

14.
Ann Hum Genet ; 83(6): 434-444, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31111486

RESUMO

Oral folate is currently the most common treatment for hyperhomocysteinemia (HHcy), which seriously threatens human health, but its efficacy is unsatisfactory. Betaine-homocysteine methyltransferase (BHMT) is a key enzyme that regulates Hcy metabolism. We investigated the association between the BHMT rs3733890 and the efficacy of oral folate therapy for HHcy in the Chinese Han population and analysed the effects of gene-environmental interactions on the efficacy. Blood samples were collected from 1071 eligible patients at baseline, and these individuals received subsequent folate treatment for 90 days. A total of 638 patients included in the final analysis were grouped into the treatment success group or the treatment failure group based on posttreatment Hcy levels. Hcy concentrations were measured by fluorescence polarization immunoassay. Time-of-flight mass spectrometry (MassArray system) was used to assess the genotype of BHMT rs3733890. Stratified analyses based on additive models and generalized multifactor dimensionality reduction were used to explore gene-environmental interactions. The genotype distribution presented distinct differences in the two groups. The mutant genotype and allele had significantly increased risk of treatment failure (p < 0.05). Furthermore, synergistic effects of the BHMT rs3733890 polymorphism with environmental risk factors (smoking, drinking, past history) on the efficacy of therapy were also found. However, future, large well-designed studies, as well as mechanistic studies, are still needed to validate our findings.


Assuntos
Alelos , Betaína-Homocisteína S-Metiltransferase/genética , Ácido Fólico/uso terapêutico , Hiper-Homocisteinemia/tratamento farmacológico , Hiper-Homocisteinemia/genética , Polimorfismo de Nucleotídeo Único , Administração Oral , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Meio Ambiente , Feminino , Ácido Fólico/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Resultado do Tratamento
15.
Chemistry ; 24(46): 11973-11982, 2018 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-29869814

RESUMO

Disulfide/thiolate interconversion controlled by Cu is proposed to be involved in relevant biological processes. In analogy to Cu, it can be envisaged that Fe also participates in the control of similar biological processes. We describe here Fe complexes that undergo FeIII -thiolate/FeII -disulfide (inter)conversion mediated by halide (de)coordination, and by the nature of the solvent. The dinuclear FeII -disulfide complex [FeII2 (LSSL)]2+ ((LS)2- =2,2'-(2,2'-bipyridine-6,6'-diyl)bis(1,1-diphenylethanethiolate), (LSSL)2- =the corresponding disulfide ligand) shows solvent-dependent properties. Whereas in a non-coordinating solvent (CH2 Cl2 ) the dinuclear FeII -disulfide complex is the only stable form, in the presence of coordinating solvents like MeCN or DMF it is partly or fully converted into mononuclear FeIII -thiolate species having a bound solvent molecule ([FeIII (LS)(Solv)]+ , Solv=DMF, MeCN). Addition of Cl- to a CH2 Cl2 solution containing the FeII -disulfide dinuclear complex leads to the fast and quantitative formation of a mononuclear FeIII -thiolate species with a bound Cl- , that is, ([FeIII (LS)Cl]). The reverse reaction can be achieved by addition of Li[[B(C6 F5 )4 ]. In relation to the metal-sulfur electronic distribution, the comparison between the redox properties of the Fe, Mn and Co complexes involved in these MIII -thiolate/MII -disulfide interconversion processes allow one to rationalize their respective efficiency.

16.
Chemistry ; 24(20): 5091-5094, 2018 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-29447424

RESUMO

The complexes [FeLN2S2 X] [in which LN2S2 =2,2'-(2,2'-bipryridine-6,6'-diyl)bis(1,1'-diphenylethanethiolate) and X=Cl, Br and I], characterized crystallographically earlier and here (Fe(L)Br), reveal a square pyramidal coordinated FeIII ion. Unusually, all three complexes have intermediate spin ground states. Susceptibility measurements, powder cw X- and Q-band EPR spectra, and zero-field powder Mössbauer spectra show that all complexes display distinct magnetic anisotropy, which has been rationalized by DFT calculations.

17.
Br J Nutr ; 119(8): 887-895, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29644956

RESUMO

The aim of this study is to analyse the efficacy rate of folate for the treatment of hyperhomocysteinaemia (HHcy) and to explore how folate metabolism-related gene polymorphisms change its efficacy. This study also explored the effects of gene-gene and gene-environment interactions on the efficacy of folate. A prospective cohort study enrolling HHcy patients was performed. The subjects were treated with oral folate (5 mg/d) for 90 d. We analysed the efficacy rate of folate for the treatment of HHcy by measuring homocysteine (Hcy) levels after treatment. Unconditioned logistic regression was conducted to analyse the association between SNP and the efficacy of folic acid therapy for HHcy. The efficacy rate of folate therapy for HHcy was 56·41 %. The MTHFR rs1801133 CT genotype, TT genotype and T allele; the MTHFR rs1801131 AC genotype, CC genotype and C allele; the MTRR rs1801394 GA genotype, GG genotype and G allele; and the MTRR rs162036 AG genotype and AG+GG genotypes were associated with the efficacy of folic acid therapy for HHcy (P<0·05). No association was seen between other SNP and the efficacy of folic acid. The optimal model of gene-gene interactions was a two-factor interaction model including rs1801133 and rs1801394. The optimal model of gene-environment interaction was a three-factor interaction model including history of hypertension, history of CHD and rs1801133. Folate supplementation can effectively decrease Hcy level. However, almost half of HHcy patients failed to reach the normal range. The efficacy of folate therapy may be genetically regulated.


Assuntos
Ácido Fólico/metabolismo , Ácido Fólico/uso terapêutico , Hiper-Homocisteinemia/tratamento farmacológico , Hiper-Homocisteinemia/genética , Polimorfismo de Nucleotídeo Único , Idoso , Estudos de Coortes , Feminino , Regulação da Expressão Gênica , Interação Gene-Ambiente , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
18.
Angew Chem Int Ed Engl ; 57(49): 16001-16004, 2018 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-30307683

RESUMO

[NiFe]-hydrogenase enzymes are efficient catalysts for H2 evolution but their synthetic models have not been reported to be active under aqueous conditions so far. Here we show that a close model of the [NiFe]-hydrogenase active site can work as a very active and stable heterogeneous H2 evolution catalyst under mildly acidic aqueous conditions. Entry in catalysis is a NiI FeII complex, with electronic structure analogous to the Ni-L state of the enzyme, corroborating the mechanism modification recently proposed for [NiFe]-hydrogenases.


Assuntos
Hidrogênio/metabolismo , Hidrogenase/metabolismo , Modelos Biológicos , Biocatálise , Domínio Catalítico , Teoria da Densidade Funcional , Hidrogênio/química , Concentração de Íons de Hidrogênio , Hidrogenase/química , Conformação Molecular , Soluções , Água/química , Água/metabolismo
19.
J Am Coll Nutr ; 36(7): 528-532, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28854002

RESUMO

BACKGROUND: Increased plasma homocysteine (Hcy) levels are a risk factor for stroke and can be reduced with folic acid therapy. Therefore, it is extremely important for patients with hyperhomocysteinemia (HHcy) to obtain the normal level of Hcy after folate intervention. Thus far, few studies have reported the effective rate defined as percentage of patients who achieved normal plasma Hcy levels after folic acid therapy. OBJECTIVES: The present study aimed to investigate the effective rate of folic acid for the treatment of HHcy and the impact of plasma baseline Hcy levels and the compliance of oral folic acid on the efficacy. METHODS: A total of 858 patients with HHcy were treated with oral folic acid (5 mg/d) for 3 months. Fasting blood samples collected at baseline and at the end of treatment were assayed for plasma Hcy levels. RESULTS: After 3 months of treatment, the plasma Hcy levels of 484 patients were reduced to below the normal levels (15 µmol/L), corresponding to an effective rate of 56.41%. The average of Hcy levels decreased by 28.05%. The effective rates of folic acid therapy in a mild Hcy elevated group and an intermediate Hcy elevated group were 61.34% and 27.78%, respectively (p = 0.000). The effective rates among patients with good and poor compliance of oral folic acid were 65.29% and 35.18%, respectively (p = 0.000). CONCLUSIONS: More than 40% patients with HHcy failed to reach the normal range (5-15 µmol/L) after 3 months of folic acid supplementation. Further prospective studies are warranted to explore the reasons for failure.


Assuntos
Ácido Fólico/uso terapêutico , Homocisteína/sangue , Hiper-Homocisteinemia/tratamento farmacológico , Complexo Vitamínico B/uso terapêutico , Idoso , Suplementos Nutricionais , Feminino , Ácido Fólico/farmacologia , Humanos , Hiper-Homocisteinemia/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Resultado do Tratamento , Complexo Vitamínico B/farmacologia
20.
ACS Appl Mater Interfaces ; 16(13): 16573-16579, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38511295

RESUMO

The intrinsic stability of the acceptor is a crucial component of the photovoltaic device stability. In this study, we investigated the efficiency and stability of the nonfused-ring acceptors LC8 and BC8 under indoor light conditions. Interestingly, we found that devices based on BC8 with terminal side chains exhibited a higher indoor efficiency and stability. Through accelerated aging experiments, we discovered that the acceptors generate singlet oxygen under light exposure with BC8 demonstrating lower levels of ROS compared to LC8. We attribute this difference to the modulation of the acceptor aggregation orientation. Furthermore, the generated reactive oxygen species (ROS) further deteriorate the acceptor structure, and this phenomenon is also observed in high-efficiency acceptor structures, such as Y6. Our research reveals important mechanisms of acceptor photo-oxidation processes, providing a theoretical basis for enhancing the intrinsic stability of acceptors.

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