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In this work, a simple strategy for fabricating a 3D nitrogen doped holey graphene hydrogel decorated with NiCo 2 O 4 nanoflowers (NHGH/NiCo 2 O 4 ) via a one-pot hydrothermal method with subsequent calcination is reported for the first time. The novel NHGH/NiCo 2 O 4 nanocomposites featured high electrical conductivity, large and accessible surface areas, abundant active sites, and excellent electrocatalytic performance. Considering the excellent catalytic activity of NiCo 2 O 4 , a sensitive and bifunctional electrochemical non-enzymatic biosensor was established for the determination of glucose and hydrogen peroxide (H 2 O 2 ). The obtained biosensor exhibited wide linear ranges (glucose: 0.005-10.95 mM; H 2 O 2 : 1-510 μM) and a low detection limits (glucose: 0.39 μM; H 2 O 2 : 0.136 μM) in alkaline solution (S/N = 3). Excellent electrocatalytic activity of this sensor was ascribed to the synergistic effects of the hybrid structure between the NiCo 2 O 4 nanoflowers and NHGH. Furthermore, the sensitive biosensor also exhibited high selectivity and could be applied to determine glucose in real blood samples. Taken together, the results reveal that the proposed hybrid nanocomposite could be a promising electrochemical biosensor., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: This study aimed to determine the differences in clinical parameters among Han, Uygur, and Kazak men with normal glucose tolerance., Methods: Participants' data from the China National Diabetes and Metabolic Disorders Study pertaining to Han, Uygur, and Kazak men from the Xinjiang province were used (n = 930). Pearson's correlation was used to examine the relationship between HOMA-IR, Matsuda Index, and clinical characteristics., Results: HOMA-IR of Han men was significantly higher than in Uygurs and Kazaks (P < 0.001). The Matsuda Index of Kazaks was significantly higher than that of Hans and Uygurs (P < 0.001). While Kazaks had the highest BMI, WC, SBP, and DBP; they also had the highest HDL-C and lowest TG (P < 0.001). TG of Uygurs was significantly higher than that of Hans and Kazaks (P < 0.001). In Hans and Kazaks, the TG/HDL-C ratio increased with HOMA-IR quartiles; there was no association in Uygurs. In Hans and Kazaks, the TG/HDL-C ratio decreased with Matsuda index quartiles; there was no association in Uygurs. Multivariate linear regression showed that HOMA-IR was independently associated with ethnicity, BMI and TG/HDL-C ratio (P < 0.01), while Matsuda index was independently associated with ethnicity, BMI, LDL-C levels (P < 0.001) and TG/HDL-C ratio (P < 0.001)., Conclusions: In conclusion, Han, Uygur, and Kazak men had different lipid profiles, BMI, and WC. Han men had the highest insulin resistance while Kazak men had the highest insulin sensitivity.

Epithelial-mesenchymal transition (EMT) has been recognized to accelerate peritoneal membrane dysfunction. 1,25(OH)2D3/vitamin D receptor (VDR) is important for preventing various types of EMT in vivo. However, its function on EMT and inflammation of human peritoneal mesothelial cells (HPMCs) remains to be elucidated. Therefore, the present study investigated the effects of 1,25(OH)2D3/VDR on high glucose (HG)‑induced EMT and inflammation in HPMCs and the underlying molecular mechanism. It was determined that HG reduced VDR expression, increased inflammatory cytokine expression, including transforming growth factor β (TGFβ) and interleukin‑6 (IL‑6) and phosphorylated‑SMAD family member 3 (p‑Smad3) expression. EMT was promoted as the expression level of the epithelial marker E‑cadherin was reduced, whereas expression levels of the mesenchymal markers α‑SMA and FN were increased. 1,25(OH)2D3 pretreatment inhibited the expression of inflammatory cytokines in HPMCs and attenuated HG‑induced EMT, possibly through inhibition of the TGFβ/Smad pathway by binding to its receptor VDR.

The regulation of cell proliferation, differentiation and immunomodulation are affected by 1,25(OH)2D3. However, its function during apoptosis and oxidative stress in human peritoneal mesothelial cells (HPMCs) remains unknown. The aim of the present study was to investigate whether the regulation of apoptosis and oxidative stress have therapeutic relevance in peritoneal dialysis (PD) therapy. The present study investigated the effects of 1,25(OH)2D3 on high glucose (HG)-induced apoptosis and reactive oxygen species (ROS) production in HPMCs, and examined the underlying molecular mechanisms. Flow cytometry and western blotting were performed to detect cell apoptosis, 2,7-dichlorofluorescein diacetate was used to measure reactive oxygen species production and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was used to measure cell viability. The results of the present study demonstrated that exposure to HG increased apoptosis and ROS production in HPMCs, whereas pretreatment with 1,25(OH)2D3 significantly inhibited HG‑induced apoptosis and ROS production. Further analysis revealed that 1,25(OH)2D3 facilitated cell survival via the MAPK/P38 pathway. The results of the present study indicate that 1,25(OH)2D3 inhibits apoptosis and ROS production in HG‑induced HPMCs via inhibition of the MAPK/P38 pathway.

Ascorbic acid is necessary for optimal insulin secretion from pancreatic islets. We evaluated ascorbate recycling and whether it is impaired by increased glucose metabolism in the rat beta-cell line INS-1. INS-1 cells, engineered with the potential for overexpression of glucokinase under the control of a tetracycline-inducible gene expression system, took up and reduced dehydroascorbic acid to ascorbate in a concentration-dependent manner that was optimal in the presence of physiologic D-glucose concentrations. Ascorbate uptake did not affect intracellular GSH concentrations. Whereas depletion of GSH in culture to levels about 25% of normal also did not affect the ability of the cells to reduce dehydroascorbic acid, more severe acute GSH depletion to less than 10% of normal levels did impair dehydroascorbic acid reduction. Culture of inducible cells in 11.8 mM D-glucose and doxycycline for 48 h enhanced glucokinase activity, increased glucose utilization, abolished D-glucose-dependent insulin secretion, and increased generation of reactive oxygen species. The latter may have contributed to subsequent decreases in the ability of the cells both to maintain intracellular ascorbate and to recycle it from dehydroascorbic acid. Cultured beta cells have a high capacity to recycle ascorbate, but this is sensitive to oxidant stress generated by increased glucose metabolism due to culture in high glucose concentrations and increased glucokinase expression. Impaired ascorbate recycling as a result of increased glucose metabolism may have implications for the role of ascorbate in insulin secretion in diabetes mellitus and may partially explain glucose toxicity in beta cells.

Pancreatic beta cells secrete insulin in response to changes in the extracellular glucose. However, prolonged exposure to elevated glucose exerts toxic effects on beta cells and results in beta cell dysfunction and ultimately beta cell death (glucose toxicity). To investigate the mechanism of how increased extracellular glucose is toxic to beta cells, we used two model systems where glucose metabolism was increased in beta cell lines by enhancing glucokinase (GK) activity and exposing cells to physiologically relevant increases in extracellular glucose (3.3-20 mm). Exposure of cells with enhanced GK activity to 20 mm glucose accelerated glycolysis, but reduced cellular NAD(P)H and ATP, caused accumulation of intracellular reactive oxygen species (ROS) and oxidative damage to mitochondria and DNA, and promoted apoptotic cell death. These changes required both enhanced GK activity and exposure to elevated extracellular glucose. A ROS scavenger partially prevented the toxic effects of increased glucose metabolism. These results indicate that increased glucose metabolism in beta cells generates oxidative stress and impairs cell function and survival; this may be a mechanism of glucose toxicity in beta cells. The level of beta cell GK may also be critical in this process.

A high-performance nonenzymatic glucose sensor was successfully prepared by a layer by layer strategy through electrodeposition assembling multilayer films of Cu-metal-organic frameworks/multi-walled carbon nanotubes (Cu-MOF/MWNTs) modified glassy carbon electrodes (GCE). Different multilayer films of Cu-MOF/MWNTs modified GCE (Cu-MOF/MWNTs/GCE) were prepared by repeating the electrodeposition of MWNTs onto the GCE in an MWNTs solution (MWNTs/GCE) and electrodeposition of the Cu-MOF layer onto the MWNTs film surface to form a Cu-MOF/MWNTs composite layer in the crystallization solution of Cu-MOF. Results confirmed that this method to fabricate multilayer composite films on the GCE was fast and convenient, and that multilayer composite films were stable and unified. The electrode modified by the multilayer composite films could effectively increase the exposure of active sites and increase the surface area of reactive contact. The GCE modified by eight layers (four multilayers Cu-MOF/MWNTs films) showed the optimum catalytic performance in the oxidation of glucose. The novel glucose sensor exhibited a wider detection linear range of 0.5 μM–11.84 mM, with a detection limit of 0.4 μM and a sensitivity of 3878 μA cm−2 mM−1. Moreover, the electrochemical response of the sensor on glucose was fast (within 0.3 s) and stable, exhibited good selectivity and was free of interference. • A novel and high-performance glucose sensor fabricated by electrodepositing of Cu-MOF and MWNTs was first employed. • Rich active sites of the deposited Cu-MOF films and the MWNTs make the sensor shows high catalytic activity for glucose. • The sensor has a wide detection linear range from 0.5 to 11840 μM and a detection limit of as low as 0.4 μM. • Fabricated sensor shows excellent capacity of resisting disturbance of AA, UA, DA, CaCl 2 , sucrose and D-fructose. • After a period of use, fabricated sensor can still maintain good stability and reproducibility. [ABSTRACT FROM AUTHOR]

Background: Sugarcane, a tropical C4 perennial crop, is capable of producing 30–100 tons or more of biomass per hectare annually. The lignocellulosic residue remaining after sugar extraction is currently underutilized and can provide a significant source of biomass for the production of second-generation bioethanol. Results: MYB31 and MYB42 were cloned from maize and expressed in sugarcane with and without the UTR sequences. The cloned sequences were 98 and 99 % identical to the published nucleotide sequences. The inclusion of the UTR sequences did not affect any of the parameters tested. There was little difference in plant height and the number of internodes of the MYB-overexpressing sugarcane plants when compared with controls. MYB transgene expression determined by qPCR exhibited continued expression in young and maturing internodes. MYB31 downregulated more genes within the lignin biosynthetic pathway than MYB42. MYB31 and MYB42 expression resulted in decreased lignin content in some lines. All MYB42 plants further analyzed showed significant increases in glucose release by enzymatic hydrolysis in 72 h, whereas only two MYB31 plants released more glucose than control plants. This correlated directly with a significant decrease in acid-insoluble lignin. Soluble sucrose content of the MYB42 transgenic plants did not vary compared to control plants. Conclusions: This study demonstrates the use of MYB transcription factors to improve the production of bioethanol from sugarcane bagasse remaining after sugar extraction. [ABSTRACT FROM AUTHOR]

• A simple and easy fabrication method for laser engraved porous graphene (LEPG). • Bi-functional H2O2 and glucose electrochemical sensor were designed based on GOD/Pt-LEPG. • The obtained flexible sensor exhibited a high sensitivity by decorating Pt NPs and immobilizing glucose oxidase. • A simple and effective way to fabricate flexible electronic devices was explored. Polyimide-laser-engraved porous graphene (LEPG) are hopeful electrode modification materials for flexible electrochemical sensing based on its high-efficiency preparation and low cost. Herein, a flexible, multi-patterned, and miniaturized electrode was fabricated via a simple and novel direct laser engraving. 3D LEPG with porous network structure can selective decorated with Pt nanoparticles (Pt NPs) by in situ electrochemical depositions (Pt-LEPG) as sensitively H 2 O 2 sensors with a wide range of linear (0.01–29 nM) and high sensitivity (575.75 μA mM−1 cm-2). Subsequently, a glucose biosensor was successfully constructed through immobilized glucose oxidases (GOD) onto Pt-LEPG electrode. New-designed GOD/Pt-LEPG glucose sensor exhibited a noteworthy lower limit of detection (0.3 μM, S/N = 3) and high sensitivity (241.82 μA mM-1 cm-2), as much a wide-range of linear (0.01–31.5 mM) at near-neutral pH conditions, enabling detect glucose in real human serum specimens with satisfactory results. Predictably, these outstanding performance sensors have great potential in terms of flexible and wearable electronics. [ABSTRACT FROM AUTHOR]

Abstract: Two novel β-glucosidase genes designated as bgl1D and bgl1E, which encode 172- and 151-aa peptides, respectively, were cloned by function-based screening of a metagenomic library from uncultured soil microorganisms. Sequence analyses indicated that Bgl1D and Bgl1E exhibited lower similarities with some putative β-glucosidases. Functional characterization through high-performance liquid chromatography demonstrated that purified recombinant Bgl1D and Bgl1E proteins hydrolyzed d-glucosyl-β-(1–4)-d-glucose to glucose. Using p-nitrophenyl-β-d-glucoside as substrate, K m was 0.54 and 2.11mM, and k cat/K m was 1489 and 787mM−1 min−1 for Bgl1D and Bgl1E, respectively. The optimum pH and temperature for Bgl1D was pH 10.0 and 30°C, while the optimum values for Bgl1E were pH 10.0 and 25°C. Bgl1D exhibited habitat-specific characteristics, including higher activity in lower temperature and at high concentrations of AlCl3 and LiCl. Bgl1D also displayed remarkable activity across a broad pH range (5.5–10.5), making it a potential candidate for industrial applications. [ABSTRACT FROM AUTHOR]