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The large-scale hydrogen production and application through electrocatalytic water splitting depends crucially on the development of highly efficient, cost-effective electrocatalysts for oxygen evolution reaction (OER), which, however, remains challenging. Here, a new electrocatalyst of trimetallic Fe-Co-Ni hydroxide (denoted as FeCoNiOx Hy ) with a nanotubular structure is developed through an enhanced Kirkendall process under applied potential. The FeCoNiOx Hy features synergistic electronic interaction between Fe, Co, and Ni, which not only notably increases the intrinsic OER activity of FeCoNiOx Hy by facilitating the formation of *OOH intermediate, but also substantially improves the intrinsic conductivity of FeCoNiOx Hy to facilitate charge transfer and activate catalytic sites through electrocatalyst by promoting the formation of abundant Co3+ . Therefore, FeCoNiOx Hy delivers remarkably accelerated OER kinetics and superior apparent activity, indicated by an ultra-low overpotential potential of 257 mV at a high current density of 200 mA cm-2 . This work is of fundamental and practical significance for synergistic catalysis related to advanced energy conversion materials and technologies.
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Artificial light-driven splitting of water into hydrogen involves multiple links to emulate natural photosynthesis, including light absorption, electron or energy transfer, surface catalysis etâ al., in which, the mass transportation of sacrificial reagent and reactant is always ignored. Metal-organic cage (MOC) of Pd6 Ru8 (MOC-16), assembling multiple photosensitive Ru and catalytic Pd concomitant with directional electron transfer between them, provides an opportunity to explore the environmental effects from the view point of mass transportation without disturbance of other links. Zr-MOF of UiO-66 is used as a matrix to heterogenize MOC-16 and a series of characterizations are carried out to unravel the composition, structure and optical properties. The intact MOC-16 remains with long-term photo-stability and the outstanding photocatalytic activity is obtained by virtue of a long-lived triplet state. Three matrixes of ZIF-8, ZIF-8 derived carbonate CZIF, and UiO-66 are intercompared for mass transfer based on wettability and porous structure. Water molecule directly takes part in the formation of H2 catalyzed by MOC-16@UiO-66, evidenced by a kinetic isotope effect, in addition to the proton delivery thanks to the hydrophilic nature of UiO-66. The porous structure of UiO-66 is essential for the permeation of sacrificial reagent to serve as two-electron donor, in sharp contrast as one-electron donor in nonporous CZIF matrix. These results highlight the importance of microenviroment surrounding molecular catalysts in view of the heterogenization of molecular catalysts, meanwhile, providing a prominent guidance on how to choose 3D support to bridge the homogenous and heterogenous system.
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The rational design and synthesis of highly efficient electrocatalysts for oxygen evolution reaction (OER) is of critical importance to the large-scale production of hydrogen by water electrolysis. Here, we develop a bimetallic, synergistic, and highly efficient Co-Fe-P electrocatalyst for OER, by selecting a two-dimensional metal-organic framework (MOF) of Co-ZIF-L as the precursor. The Co-Fe-P electrocatalyst features pronounced synergistic effects induced by notable electron transfer from Co to Fe, and a large electrochemical active surface area achieved by organizing the synergistic Co-Fe-P into hierarchical nanosheet arrays with disordered grain boundaries. Such features facilitate the generation of abundant and efficiently exposed Co3+ sites for electrocatalytic OER and thus enable Co-Fe-P to deliver excellent activity (overpotential and Tafel slope as low as 240 mV and 36 mV dec-1, respectively, at a current density of 10 mA cm-2 in 1.0 M KOH solution). The Co-Fe-P electrocatalyst also shows great durability by steadily working for up to 24 h. Our work thus provides new insight into the development of highly efficient electrocatalysts based on nanoscale and/or electronic structure engineering.
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Application of a molecular catalyst in artificial photosynthesis is confronted with challenges such as rapid deactivation due to photodegradation or detrimental aggregation in harsh conditions. In this work, a metal-organic cage [Pd6(RuL3)8]28+ (MOC-16), characteristic of a photochemical molecular device (PMD) concurrently integrating eight Ru2+ light-harvesting centers and six Pd2+ catalytic centers for efficient homogeneous H2 production, is successfully heterogenized through incorporation into a metal-organic framework (MOF) of ZIF-8 and then transformed into a carbonate matrix of Znx(MeIm)x(CO3)x (CZIF), leading to hybridized MOC-16@CZIF. This MOC@MOF integrated photocatalyst inherits a highly efficient and directional electron transfer in the picosecond domain of MOC-16 and possesses one order increased microsecond magnitude of the triplet excited-state electron in comparison to that of the primitive MOC-16. The carbonate CZIF matrix endows MOC-16@CZIF with water wettability, serving as a proton relay to facilitate proton delivery by virtue of H2O as proton carriers. Electron transfer during the photocatalytic process is also enhanced by infiltration of a sacrificial agent of BIH into the CZIF matrix to promote conductivity, owing to its strong reducing ability to induce free charge carriers. These synergistic effects contribute to the extra high activity for H2 generation, making the turnover frequency of this heterogeneous MOC-16@CZIF photocatalyst maintain a level of â¼0.4 H2·s-1, increased by 50-fold over that of a homogeneous PMD. Meanwhile, it is robust enough to tolerate harsh reaction conditions, presenting an unprecedented heterogenization example of homogeneous PMD with a MOF-derived matrix to mimic catalytic features of a natural photosystem, which may shed light on the design of multifunctional PMD@MOF materials to expand the number of molecular catalysts for practical application in artificial photosynthesis.
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BACKGROUND Protective effects of reduced beta 2 glycoprotein I (Rb2GPI) against vascular injury of diabetes mellitus have been extensively investigated. However, the effects of Rb2GPI on liver injury in diabetic animals have not been reported. MATERIAL AND METHODS A diabetic rat model of was produced by systemic injection of streptozotocin (STZ). Rats were divided into a normal control group, a model group, and an Rb2GPI treatment group (N=6 in each group). After treatments, blood serum and liver tissue were collected to test the protection of Rb2GPI. AMP-activated protein kinase (AMPK) was detected by immunohistochemistry and Western blotting. RESULTS Our results revealed that Rß2GPI reduced blood glucose, serum creatinine, and urea nitrogen levels, as well as serum inflammation cytokines, including interleukin (IL)-6, tumor necrosis factor (TNF)-α and C-reactive protein in the diabetic rats. Importantly, Rß2GPI prevented liver injury in the diabetic rats as confirmed by hematoxylin-eosin (H&E) staining, alanine transaminase, aspartate transaminase, and gamma-glutamyl transferase. Reactive oxygen species (ROS) were promoted by diabetic modeling and were attenuated by Rß2GPI administration. Moreover, Rß2GPI significantly reduced liver catalase, malondialdehyde, and superoxide dismutase levels in the diabetic rats. Rß2GPI reduced liver glycolipid storage in STZ diabetic rats. Both immunohistochemistry and Western blotting demonstrated that Rß2GPI promoted AMPK phosphorylation in the diabetic rats. CONCLUSIONS Our data proved that Rß2GPI prevented liver injury in diabetic rats, likely through activating the AMPK signaling pathway.
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Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , beta 2 Glicoproteína I/metabolismo , beta 2 Glicoproteína I/farmacología , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Glucemia/análisis , Proteína C-Reactiva/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Creatinina/análisis , Creatinina/sangre , Complicaciones de la Diabetes/tratamiento farmacológico , Complicaciones de la Diabetes/metabolismo , Diabetes Mellitus Experimental/metabolismo , Modelos Animales de Enfermedad , Interleucina-6/metabolismo , Hígado/patología , Masculino , Estrés Oxidativo/efectos de los fármacos , Fosforilación , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/efectos de los fármacos , Estreptozocina/farmacología , Superóxido Dismutasa/metabolismo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
BACKGROUND Subclinical hypothyroidism (SCH) is typically featured by elevated serum concentration of thyroid-stimulating hormone (TSH). This study aimed to determine the relationship between TSH levels and microvascular complications in type 2 diabetes patients. MATERIAL AND METHODS A total of 860 type 2 diabetes patients were enrolled in this cross-sectional study. Subjects were evaluated for anthropometric measurements, thyroid function, diabetic retinopathy, and diabetic kidney disease. TSH was divided into 3 levels: 0.27-2.49 mU/l, 2.5-4.2 mU/l, and >4.2 mU/l. RESULTS Among the participants, 76 subjects (8.8%) were diagnosed with subclinical hypothyroidism (SCH) (male: 6.6% and female: 11.8%). The prevalence of diabetic retinopathy did not differ among the groups (P=0.259). Of the 860 type 2 diabetic subjects, we further excluded invalid or missing data. Therefore, 800 and 860 subjects were included in our study of diabetic retinopathy (DR) and diabetic kidney disease (DKD), respectively. The frequencies of microalbuminuria and macroalbuminuria differed significantly among the different groups. The frequency of DKD was significantly different among the 3 groups (P=0.001) and was higher in subjects with higher TSH levels. After an adjustment for confounding variables, TSH levels were significantly associated with DKD (P<0.001). When compared with subjects with TSH 0.27-2.49 mU/l, the frequency of DKD was higher in subjects with TSH >4.20 mU/l (OR 1.531, 95% CI 1.174-1.997) and with TSH 2.50-4.20 mU/l (OR 1.579, 95% CI 1.098-2.270). However, TSH levels was not significantly correlated with DR (P=0.126). CONCLUSIONS Type 2 diabetic patients with higher TSH values had a higher prevalence of DKD.
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Complicaciones de la Diabetes/sangre , Diabetes Mellitus Tipo 2/sangre , Microvasos/patología , Tirotropina/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , PrevalenciaRESUMEN
OBJECTIVE: To evaluate the clinical practical value of apparent diffusion coefficient (ADC) measurements based on diffusion-weighted MR imaging (DWI) for quantification of liver fibrosis and inflammation for hepatitis viral infection. METHODS: Diffusion-weighted MRI with parallel imaging was prospectively performed on 85 patients with chronic hepatitis and on 22 healthy volunteers within a single breath-hold using a single-shot spin-echo echo-planar sequence at b values of 100, 300, 500, 800 and 1000 s/mm2 respectively. ADC values of liver were measured with five different b values. The inflammation grades and fibrosis stages were evaluated histologically by biopsy. One-way analysis of variance and Spearman' s rank correlation test were used for statistical analysis. Receiver operating characteristics analysis was used to assess the performance of ADC in predicting the presence of stage > or = 2 and stage > or = 3 hepatic fibrosis, and grade > or = 1 hepatic inflammation. RESULTS: There was moderate negative correlation between hepatic ADC values and fibrosis stage. And the best correlation was obtained for a b value of 800 s/mm2 (r = -0.697, P = 0. 000). At all b values there was a significant decrease in hepatic ADC in patients with stage < or = 1 versus stage > or = 2 fibrosis and stage < or = 2 versus stage > or = 3 fibrosis (P < 0.05). Hepatic ADC was a significant predictor of stage > or = 2 and > or = 3 fibrosis. The areas under the curve were 0.909 vs 0.917, sensitivity 76.6% vs 80.0% and specificity 88.3% vs 91.5% (ADC with a b value of 800 s/mm2, 1.26 x 10(-3) mm2/s or less and 1.19 x 10(-3) mm2/s or less). There was weak to moderate negative correlation between ADCs and inflammation grade. Hepatic ADC was a significant predictor of grade > 1 inflammation with an area under the curve of 0.781, sensitivity of 60.0% and specificity of 86.4% (ADC with a b value of 500 s/mm2, 1.54 x 10(-3) mm2/s or less). CONCLUSION: The DWI measurement of hepatic ADC can be used to quantify liver fibrosis and inflammation. It will be a new approach for early diagnosis and therapeutic follow-up of hepatic fibrosis.
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Imagen de Difusión por Resonancia Magnética/métodos , Hepatitis Crónica/patología , Cirrosis Hepática/patología , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Adulto JovenRESUMEN
BACKGROUND: Adipocyte fatty acid-binding protein (A-FABP) has been recognized as an important player in macrophage cholesterol trafficking and inflammation, and may promote the development of atherosclerosis. To further elucidate the role of A-FABP in atherosclerosis in diabetes, we investigated the relationship between serum A-FABP concentrations and peripheral arterial disease (PAD) in patients with type 2 diabetes mellitus (T2DM). METHODS: In all, 488 inpatients with T2DM were enrolled in the study (254 men, 234 women; mean (±SD) age 57.3 ± 13.0 years). The severity of peripheral arterial stenosis was assessed by ultrasound examination. Serum A-FABP concentrations were determined by ELISA. RESULTS: Serum A-FABP concentrations were significantly higher in patients with than without PAD (8.0 ± 3.3 vs 6.2 ± 1.6 ng/mL, respectively; P < 0.05). Interestingly, there was an obvious gender-related difference in PAD patients with T2DM, with the stenosis rate being higher for female than male T2DM patients in the third A-FABP tertile. Logistic regression analysis revealed that serum A-FABP concentrations were an independent risk factor for PAD in female T2DM patients (odds ratio 1.890, 95% confidence interval 1.041-3.432; P = 0.036), but not in male T2DM patients. Correlation analyses revealed that A-FABP concentrations were correlated with body mass index (BMI), diastolic blood pressure, urinary microalbumin, and serum creatinine in male patients, and with BMI, duration of T2DM, fasting blood glucose, and serum creatinine in female patients. CONCLUSIONS: Serum A-FABP concentrations are closely associated with PAD in Chinese women with T2DM. The study findings suggest that A-FABP may be a more specific marker of PAD in diabetic women than men.
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Adipocitos/metabolismo , Biomarcadores/análisis , Diabetes Mellitus Tipo 2/fisiopatología , Proteínas de Unión a Ácidos Grasos/sangre , Enfermedad Arterial Periférica/sangre , Enfermedad Arterial Periférica/diagnóstico , Adipocitos/patología , Adulto , Pueblo Asiatico , Glucemia/análisis , Índice de Masa Corporal , Femenino , Estudios de Seguimiento , Hemoglobina Glucada/análisis , Humanos , Masculino , Persona de Mediana Edad , Enfermedad Arterial Periférica/etiología , Pronóstico , Factores de Riesgo , Factores SexualesRESUMEN
BACKGROUND AND AIMS: Few drugs have been confirmed to be effective for fulminant hepatic failure (FHF). The purpose of this study was to prepare sterically stable liposomes (SSL) encapsulating hepatic stimulator substance (HSS) and determine their therapeutic effect on FHF. METHODS: HSS were encapsulated into SSL (HSS-SSL). FHF was induced in rats by thioacetamide (TAA) injection (400mg/kg, three times with a 24-h interval). The agents, including HSS-SSL, SSL, HSS, and sodium chloride (NS), were each injected intravenously 2h after the second and the third TAA injection. RESULTS: Freshly prepared HSS-SSL had a mean size of 93.59nm and the average encapsulation efficiency was 37.20%. HSS encapsulated in SSL showed a longer half life and more potent target to injured livers than free HSS. Twenty-four hours after the third TAA-injection, the survival rate of HSS-SSL-treated rats (80%) was significantly higher than that of rats treated with NS (20%), SSL (25%), or HSS (50%). Histopathologic examination showed that there was the least necrosis and inflammation in the livers of HSS-SSL-treated rats. The incidence of stage 3 or 4 hepatic encephalopathy in HSS-SSL-treated rats was significantly lower than that in rats treated with other agents. The serum pro-inflammatory cytokine levels and hepatic lipid peroxidation levels were both markedly reduced, while hepatocyte proliferative rate was markedly increased after HSS-SSL treatment. CONCLUSION: Encapsulation by SSL markedly improved the therapeutic effect of HSS on FHF in rats. Encapsulation by SSL may be an effective approach to enhance the therapeutic potency of drugs for FHF.
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Fallo Hepático Agudo/tratamiento farmacológico , Péptidos/administración & dosificación , Animales , Proliferación Celular/efectos de los fármacos , Hepatocitos/efectos de los fármacos , Hepatocitos/patología , Péptidos y Proteínas de Señalización Intercelular , Liposomas , Fallo Hepático Agudo/patología , Masculino , Péptidos/farmacocinética , Ratas , Ratas Sprague-Dawley , Tioacetamida/metabolismo , Tioacetamida/toxicidad , Distribución TisularRESUMEN
Hepatocyte growth factor (HGF) was encapsulated into sterically stabilized liposomes (SSL) in order to protect it from in vivo degradation. Cyclic Arg-Gly-Asp (RGD) peptides were combined with maleimide-[poly (ethylene glycol)]-1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (MAL-PEG-DOPE) incorporated into SSL. The average percentage of HGF encapsulated into liposomes was 32.38%, the size of liposomes was 91.56 nm and the polydispersity index was 0.164. In vivo, histological observation of the rat livers revealed that injection of RGD-SSL-HGF induced more significant remission of liver cirrhosis than injection of SSL-HGF, HGF alone, HGF plus RGD-SSL and saline. When the histological score, the collagen surface density, the hydroxyproline content and the expression of procollagen alpha1 (I) and alpha1 (III) mRNA in the liver were evaluated, all values were smallest in the RGD-SSL-HGF group. In contrast, an increase in apoptotic alpha-SMA-positive cells was noted in the RGD-SSL-HGF group. Together, this data suggests that targeted liposomes encapsulating HGF is a promising therapeutic modality in terms of promoting the remission of liver cirrhosis by promoting collagen fiber digestion, inhibiting collagen production, and promoting apoptosis of alpha-SMA-positive cells in rats with cirrhosis.