A Combination of Nutriments Improves Mitochondrial Biogenesis and Function in Skeletal Muscle of Type 2 Diabetic Goto–Kakizaki Rats

BACKGROUND: Recent evidence indicates that insulin resistance in skeletal muscle may be related to reduce mitochondrial number and oxidation capacity. However, it is not known whether increasing mitochondrial number and function improves insulin resistance. In the present study, we investigated the effects of a combination of nutrients on insulin resistance and mitochondrial biogenesis/function in skeletal muscle of type 2 diabetic Goto-Kakizaki rats. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrated that defect of glucose and lipid metabolism is associated with low mitochondrial content and reduced mitochondrial enzyme activity in skeletal muscle of the diabetic Goto-Kakizaki rats. The treatment of combination of R-alpha-lipoic acid, acetyl-L-carnitine, nicotinamide, and biotin effectively improved glucose tolerance, decreased the basal insulin secretion and the level of circulating free fatty acid (FFA), and prevented the reduction of mitochondrial biogenesis in skeletal muscle. The nutrients treatment also significantly increased mRNA levels of genes involved in lipid metabolism, including peroxisome proliferator-activated receptor-alpha (Ppar alpha), peroxisome proliferator-activated receptor-delta (Ppar delta), and carnitine palmitoyl transferase-1 (Mcpt-1) and activity of mitochondrial complex I and II in skeletal muscle. All of these effects of mitochondrial nutrients are comparable to that of the antidiabetic drug, pioglitazone. In addition, the treatment with nutrients, unlike pioglitazone, did not cause body weight gain. CONCLUSIONS/SIGNIFICANCE: These data suggest that a combination of mitochondrial targeting nutrients may improve skeletal mitochondrial dysfunction and exert hypoglycemic effects, without causing weight gain

Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening

Exfoliated black phosphorus gas sensing properties at room temperature

Room temperature gas sensing properties of chemically exfoliated black phosphorus (BP) to oxidizing (NO2, CO2) and reducing (NH3, H-2, CO) gases in a dry air carrier have been reported. To study the gas sensing properties of BP, chemically exfoliated BP flakes have been drop casted on Si3N4 substrates provided with Pt comb-type interdigitated electrodes in N2 atmosphere. Scanning electron microscopy and x-ray photoelectron spectroscopy characterizations show respectively the occurrence of a mixed structure, composed of BP coarse aggregates dispersed on BP exfoliated few layer flakes bridging the electrodes, and a clear 2p doublet belonging to BP, which excludes the occurrence of surface oxidation. Room temperature electrical tests in dry air show a p-type response of multilayer BP with measured detection limits of 20 ppb and 10 ppm to NO2 and NH3 respectively. No response to CO and CO2 has been detected, while a slight but steady sensitivity to H-2 has been recorded. The reported results confirm, on an experimental basis, what was previously theoretically predicted, demonstrating the promising sensing properties of exfoliated BP

Enhanced optical and electrical gas sensing response of sol-gel based NiO-Au and ZnO-Au nanostructured thin films

NiO and ZnO thin films of about 40-50 nm thickness with embedded Au nanoparticles have been synthesized with a simple and reliable sol-gel procedure. The nanocomposites films are crystalline and porous and they show optical absorptions in the visible range according to Au nanoparticles concentration. These films have been tested as optical and electrical sensors for pollutant gases detection. A fast and reversible response has been detected for hydrogen, CO and NO 2. Au nanoparticles have been found to improve the optical sensing properties of both NiO and ZnO films over the Au surface plasmon resonance peak wavelength range, but also to enhance the ZnO optical response in the near UV range, where Au nanoparticles are optically inactive. Moreover, combining the observed shift in the surface plasmon resonance peak and the different semiconductive type of the two oxides, it has been proved that reducing gases inject electrons into the oxide and then afterward the charge variation is detected by Au nanoparticles. Electrical tests confirm the n-type behavior of ZnO and p-type behavior of NiO, and show good performances at lower temperatures. Moreover, an enhancing effect of Au nanoparticles in the overall sensing performances is observed also in electrical tests

Response to NO<inf>2</inf> and other gases of resistive chemically exfoliated MoS<inf>2</inf>-based gas sensors

We report on the fabrication, the morphological, structural, and chemical characterization, and the study of the electrical response to NO2 and other gases of resistive type gas sensors based on liquid chemically exfoliated (in N-methyl pyrrolidone, NMP) MoS2 flakes annealed in air either at 150 °C or at 250 °C. The active material has been analyzed by scanning electron microscopy (SEM), and micro Raman and X-ray core level photoemission spectroscopies. SEM shows that MoS2 exfoliated flakes are interconnected between electrodes of the sensing device to form percolation paths. Raman spectroscopy of the flakes before annealing demonstrates that the flakes are constituted by crystalline MoS2, while, annealing at 250 °C, does not introduce a detectable bulk contamination in the expected form of MoO3. The sensor obtained by thermal annealing in air at 150 °C exhibits a peculiar p-type response under exposure to NO2. In line with core level spectroscopy evidences, this behavior is potentially ascribed to nitrogen substitutional doping of S vacancies in the MoS2 surface (nitrogen atoms being likely provided by the intercalated NMP). Thermal annealing the MoS2 flakes in air at 250 °C irreversibly sets an n-type behavior of the gas sensing device, with a NO2 detection limit of 20 ppb. This behavior is assigned, in line with core level spectroscopy data, to a significant presence of S vacancies in the MoS2 annealed flakes and to the surface co-existence of MoO3 arising from the partial oxidation of the flakes surface. Both p- and n-type sensors have been demonstrated to be sensitive also to relative humidity. The n-type sensor shows good electrical response under H2 exposure

The influence of thermal and visible light activation modes on the NO2 response of WO3 nanofibers prepared by electrospinning

The paper reports on the influence of visible light at different wavelengths (red, λ = 630 nm; green, λ = 570 nm; purple–blue, λ = 430 nm), light irradiance conditions (from 30 to 770 μW/cm2) and operating temperatures (from 25 °C to 100 °C) on the electrical response of WO3 electrospun nanofibers (NFs) to 100–400 ppb NO2 gas in dry air. WO3 NFs were prepared by mixing a W–O sol–gel transparent solution (WCl6 in ethanol) with a polymeric solution made of polyvinylpyrrolidone (PVP) and dimethylformamide (DMF). Electrospun NFs were annealed between 300 °C and 500 °C and the their microstructures features investigated by SEM and XRD. Room temperature (25 °C) gas responses of the 450 °C annealed NFs have shown that, beside a slight reduction of the relative gas response (RRs), a decrease of the light wavelength (toward the purple–blue) and an increase of its irradiance, greatly improve the base line recovery and the response time with respect to dark conditions. At operating temperatures ranging from 25 °C to 100 °C, sensor relative responses in dark always resulted to be higher as respect to the ones displayed under purple–blue light illumination. The combined action of purple-blue light with an irradiance of 770 μW/cm2 and of mild operating temperature of 75 °C, relative responses (RRs) of 12.4 and base line recovery percentages (RPs) of 97% were attained at 400 ppb NO2. The capability to tune the response of WO3 NFs to NO2 by combining light and mild thermal gas sensors activations is addressed and discussed also considering the involved response mechanisms

A simple all-solution approach to the synthesis of large ZnO nanorod networks

Soft-lithography of Zn-loaded hydrogels and a subsequent hydrothermal growth process yield self-assembling networks of bridging ZnO nanorods (NRs). They are grown on seeding micropillars of ZnO until they touch, forming junctions that provide a preferred electrical path for the operative current of functional devices (e.g. gas senors)