SGLT2 inhibitors have profound benefits on reducing heart failure and cardiovascular mortality in individuals with type 2 diabetes, although the mechanism(s) of this benefit remain poorly understood. ...Because changes in cardiac bioenergetics play a critical role in the pathophysiology of heart failure, the authors evaluated cardiac energy production and substrate use in diabetic mice treated with the SGTL2 inhibitor, empagliflozin. Empagliflozin treatment of diabetic
mice prevented the development of cardiac failure. Glycolysis, and the oxidation of glucose, fatty acids and ketones were measured in the isolated working heart perfused with 5 mmol/l glucose, 0.8 mmol/l palmitate, 0.5 mmol/l ß-hydroxybutyrate (ßOHB), and 500 μU/ml insulin. In vehicle-treated
mice, cardiac glucose oxidation rates were decreased by 61%, compared with control mice, but only by 43% in empagliflozin-treated diabetic mice. Interestingly, cardiac ketone oxidation rates in
mice decreased to 45% of the rates seen in control mice, whereas a similar decrease (43%) was seen in empagliflozin-treated
mice. Overall cardiac adenosine triphosphate (ATP) production rates decreased by 36% in
vehicle-treated hearts compared with control mice, with fatty acid oxidation providing 42%, glucose oxidation 26%, ketone oxidation 10%, and glycolysis 22% of ATP production in
mouse hearts. In empagliflozin-treated
mice, cardiac ATP production rates increased by 31% compared with
vehicle-treated mice, primarily due to a 61% increase in the contribution of glucose oxidation to energy production. Cardiac efficiency (cardiac work/O
consumed) decreased by 28% in
vehicle-treated hearts, compared with control hearts, and empagliflozin did not increase cardiac efficiency per se. Because ketone oxidation was impaired in
mouse hearts, the authors determined whether this contributed to the decrease in cardiac efficiency seen in the
mouse hearts. Addition of 600 μmol/l ßOHB to d
mouse hearts perfused with 5 mmol/l glucose, 0.8 mmol/l palmitate, and 100 μU/ml insulin increased ketone oxidation rates, but did not decrease either glucose oxidation or fatty acid oxidation rates. The presence of ketones did not increase cardiac efficiency, but did increase ATP production rates, due to the additional contribution of ketone oxidation to energy production. The authors conclude that empagliflozin treatment is associated with an increase in ATP production, resulting in an enhanced energy status of the heart.
This review encompasses the mechanisms of electrochemical glucose detection and recent advances in non-enzymatic glucose sensors based on a variety of materials ranging from platinum, gold, metal ...alloys/adatom, non-precious transition metal/metal oxides to glucose-specific organic materials. It shows that the discovery of new materials based on unique nanostructures have not only provided the detailed insight into non-enzymatic glucose oxidation, but also demonstrated the possibility of direct detection in whole blood or interstitial fluids. We critically evaluate various aspects of non-enzymatic electrochemical glucose sensors in terms of significance as well as performance. Beyond laboratory tests, the prospect of commercialization of non-enzymatic glucose sensors is discussed.
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•This review summarizes the latest progress in non-enzymatic electrochemical sensors.•The review encompasses fundamental principles of electrochemical glucose detection.•The merits and demerits of various electrode materials are discussed.•The authors critically evaluate numerous aspects concerning current research.•The prospect of clinical application of non-enzymatic glucose monitoring is described.
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•Co@NPC was prepared via one-pot pyrolysis using DES as self-template.•Coupling GOR for boosting H2 evolution and production of value-added chemicals.•N-doping optimizes the ...adsorption energy of H2O and glucose.•Graphitic N could most effectively promote the glucose oxidation reaction.
The electrocatalytic water splitting for hydrogen production is greatly limited by the sluggish anodic OER. Herein, a hybrid of cobalt nanoparticles supported in nitrogen doped porous carbon (Co@NPC) is prepared by using a biomass-based ternary deep eutectic solvent (DES) as precursor and self-templates, which is utlized as bifunctional electrocatalyst for boosting H2 generation and converting glucose into valuable chemicals simultaneously. Importantly, only a small cell voltage of 1.56 V is required to deliver 10 mA cm−2, which is 180 mV lower than that of overall water splitting. Density functional theory (DFT) calculations confirm that nitrogen doping porous carbon could synergistically optimize adsorption energies of H2O (ΔE*H2O) and *H adsorption free energies (ΔG*H), enhancing catalytic activity toward HER. This work highlights the potential application prospects of using glucose oxidation reaction (GOR) instead of OER to promote H2 generation and product value-added chemicals.
The detection of glucose is crucial in the management of diabetes and other medical conditions but also crucial in a wide range of industries such as food and beverages. The development of glucose ...sensors in the past century has allowed diabetic patients to effectively manage their disease and has saved lives. First-generation glucose sensors have considerable limitations in sensitivity and selectivity which has spurred the development of more advanced approaches for both the medical and industrial sectors. The wide range of application areas has resulted in a range of materials and fabrication techniques to produce novel glucose sensors that have higher sensitivity and selectivity, lower cost, and are simpler to use. A major focus has been on the development of enzymatic electrochemical sensors, typically using glucose oxidase. However, non-enzymatic approaches using direct electrochemistry of glucose on noble metals are now a viable approach in glucose biosensor design. This review discusses the mechanisms of electrochemical glucose sensing with a focus on the different generations of enzymatic-based sensors, their recent advances, and provides an overview of the next generation of non-enzymatic sensors. Advancements in manufacturing techniques and materials are key in propelling the field of glucose sensing, however, significant limitations remain which are highlighted in this review and requires addressing to obtain a more stable, sensitive, selective, cost efficient, and real-time glucose sensor.
Hydrogen, as the one of clean energy source, has the advantages of high energy density and carbon-free emission. Water electrolysis is one of the most promising ways to generate hydrogen, but the ...rather high energy required seriously hinders its widespread applications yet. In this study, we report an alkaline electrolyzer to implement energy-saving H2 generation by coupling cathodic hydrogen evolution reaction (HER) with anodic glucose oxidation reaction (GOR) other than oxygen evolution reaction, in which nickel-doped MoS2 nanoparticles (Ni–MoS2 NPs) has been developed as bifunctional electrocatalyst for HER and GOR. The electrolyzer only requires a cell voltage of 1.67 V to reach an electrolysis current density of 10 mA cm−2, about 270 mV lower than the corresponding value in the traditional electrolyzer. Electrolytic H2 generation with the assistance of biomass derived materials may open a new way for the future sustainable development.
•Ni-doped MoS2 was fabricated as bifunctional electrocatalyst.•Biomass derived glucose as the electron donor to replace water.•Glucose assisted electrolytic H2 generation can reduce energy consumption.
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•Pd/CeO2 exhibits higher catalytic activity than Pd/OCNT for glucose oxidation.•The catalyst deactivation is suppressed on Pd/CeO2 due to their strong interaction.•The adsorption of ...gluconic acid is weakened on Pd/CeO2.•The OHads generated on the CeO2 surface accelerates the oxidation of glucose.•Increasing the oxygen vacancy of CeO2 results in the enhanced catalytic activity.
Catalytic oxidizing of glucose into gluconic acid (GLUC) provides an attractive and feasible pathway for the high value-added utilization of glucose, in which Pd-based catalysts deliver outstanding catalytic performance. However, the surface poisoning of Pd caused by the strong adsorption of GLUC becomes the bottleneck for their further applications. Herein, oxygen-vacancy-riched ceria supported Pd catalyst (Pd/CeO2) is employed, which effectively alleviates the catalyst deactivation, and realizes high catalytic activity and stability with 100 % GLUC selectivity for glucose oxidation at room temperature. Kinetic analysis confirms the strong anti-poisoning ability of Pd/CeO2. The superior catalytic performance is attributed to the modulation of the electronic structure of Pd nanoparticles by the strong metal-support interaction between Pd and CeO2. The valence band photoemission spectra reveal that the downshift of the d-band center of Pd leads to the weak adsorption of GLUC on Pd/CeO2. Meanwhile, kinetic isotope effect experiments indicate that the OHads generated from H2O dissociation on the CeO2 surface affords another path for glucose oxidation, thus improves the catalytic activity.
Grain boundary enriched CuO nanobundle was reported to significantly increased the glucose diffusion as well as reduce the glucose oxidation barrier, thus displayed a lower onset potential of 94 mV, ...an extremely high sensitivity of 7474 μA mM−1 cm−2 in glucose detection and a high peak power density of 242 W m−2 in a glucose fuel cell.
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•CuO nanobundle with high density and homogenous GBs was obtained by a facile and large-scale method.•A high sensitivity of 7474 μA mM−1 cm−2 in glucose detection and a high peak power density of 242 W m−2 in a glucose fuel cell are achieved.•CuO-NB possesses the faster glucose mass transfer due to the terraces in GBs dislocation surface.•Electrons accumulate on GBs interfaces promote glucose adsorption and decrease free energy of dehydrogenation step.
Glucose oxidation reaction (GOR) plays a significant role in glucose fuel cells anode and glucose sensors. Therefore, optimizing the GOR catalyst nanostructure is auxiliary to their efficient operation. In this study, we present a cascade-assembled strategy to prepare CuO nanobundles (CuO-NB) with high-density and homogenous grainboundaries (GBs). The essence of activity in GOR that depended on GBs are thoroughly investigated. The increased glucose diffusion coefficient of CuO-NB means that GBs has a faster glucose mass transfer, which is attributed to the terraces in GBs dislocation surface. Furthermore, the accumulation of electrons on GBs makes the glucose adsorption increased and the free energy of dehydrogenation step decreased, leading to a lower glucose oxidation barrier. Therefore, CuO-NB is appropriate for non-invasive glucose detection and glucose fuel cells. This study sheds new light on the GBs effect in GOR and paves the way for developing high-efficiency electrocatalysts.
Gluconic acid (GOA) and glucaric acid (GAA) are valuable chemicals for a wide range of applications, yet conventional technologies for their production suffer from low efficiency, high cost, and ...especially environmental concerns. It is imperative to develop sustainable heterogeneous catalytic systems exhibiting promising catalytic activity and good recyclability. In this review, base-free glucose oxidation over structure-tailored heterogeneous catalysts is discussed, and Au-based catalysts are found to present promising potential in sustainable biorefineries. To address the issue of its cost, introducing secondary metals forming bimetallic catalysts and developing non-noble metal-based catalysts are proposed as possible solutions. GAA production is of particular interest due to its high value and yet limited investigation regarding the mechanisms and system development. The feasibility of raw biomass conversion over bifunctional catalysts is also explored for the sake of industrial application. The potential of emerging technologies including ultrasound-assisted, microwave-assisted, and photocatalytic oxidation is emphasized, which allow for milder operating conditions compared to conventional heating. This review curates the latest findings and highlights the opportunities and limitations of reported technologies, promoting the development of green catalytic systems to achieve sustainable valorization of biomass/food waste through controllable oxidation pathways.
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•Structure-tailored catalysts are highlighted for waste-derived glucose oxidation.•Non-noble metal-based catalysts and bimetallic catalysts need to be developed.•Mechanisms and catalytic systems for GAA production warrant further investigation.•The feasibility of raw biomass conversion over bifunctional catalysts is explored.•Ultrasound, microwave, and solar are emphasized as external energy sources.
Cholesterol is important for normal brain function. The brain synthesizes its own cholesterol, presumably in astrocytes. We have previously shown that diabetes results in decreased brain cholesterol ...synthesis by a reduction in sterol regulatory element-binding protein 2 (SREBP2)-regulated transcription. Here we show that coculture of control astrocytes with neurons enhances neurite outgrowth, and this is reduced with SREBP2 knockdown astrocytes. In vivo, mice with knockout of SREBP2 in astrocytes have impaired brain development and behavioral and motor defects. These mice also have altered energy balance, altered body composition, and a shift in metabolism toward carbohydrate oxidation driven by increased glucose oxidation by the brain. Thus, SREBP2-mediated cholesterol synthesis in astrocytes plays an important role in brain and neuronal development and function, and altered brain cholesterol synthesis may contribute to the interaction between metabolic diseases, such as diabetes and altered brain function.
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•2D/3D hhierarchical NiCu bimetallic MOF was developed via one-step synthesis.•Hierarchy facilitates mass and electron transfer between discrete MOF.•Highly dispersed NiCu sites ...contribute synergistically to electrocatalysis of Glu.•Sensor exhibits high sensitivity, wide linear range and good feasibility for usage.
The development of transition metal based enzyme-free glucose (Glu) sensor with high sensitivity, wide linear range, and long-term stability is highly desired. Herein, a series of 2D/3D hierarchical structured bimetallic organic framework (NiCu-MOF-x, x = 2, 4, 6, 8) were developed through a one-step hydrothermal route by adjusting the ratio of nickel and copper salts. The morphological similarity of NiCu-MOF-x and Ni-MOF was evidenced by X-ray diffraction survey. The structural evolution of NiCu-MOF-x was revealed by scanning electron microscopy. The optimal NiCu-MOF-6 exhibits high electrocatalytic activity toward Glu oxidation. Being applied as the electrode modifier for glassy carbon electrode (GCE), NiCu-MOF-6/GCE exhibits a remarkably widened linear range than its monometallic analog, owing to its significantly increased electrochemical surface area, interconnected channels for mass/electron transfer and synergistically functionalized Ni/Cu electroactive sites. Being applied in human serum analysis, this sensor shows a good feasibility with satisfying recoveries.
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