967 research outputs found

    Graphene-modified nickel foam electrode for cathodic degradation of nitrofuranzone: Kinetics, transformation products and toxicity

    Get PDF
    Simple, efficient, and durable electrodes are highly demanded for practical electro­chemical process. In this study, a reduced graphene oxide modified nickel foam electrode (GR‑Ni foam) was facilely prepared via one-step cyclic voltammetry electrodeposition of gra­phene oxide suspension onto the Ni foam. The electrochemical degradation of nitrofuran­zone (NFZ, a kind of typical antibiotics) was studied on the GR-Ni foam cathode. The cyclic voltammetry and electrochemical impedance spectra analysis confirmed that presence of GR loading accelerated the electron transfer from the cathode surface to NFZ. With the applied cathode potential of −1.25 V (vs. Ag/AgCl), the removal efficiency of NFZ (C0 = 20 mg L−1) at the GR-Ni foam electrode reached up to 99 % within 30 min, showing a higher reaction rate constant (0.1297 min−1) than 0.0870 min−1 at the Pd-Ni foam and 0.0186 min−1 at the Ni foam electrode. It was also found that the pH, dissolved oxygen and NFZ initial concentration have slight effect on NFZ degradation at the GR-Ni foam electrode. The reactions first occurred at nitro groups (-NO2), unsaturated C=N bonds and N-N bonds to generate furan ring-containing products, and then these products were transformed into linear diamine products. The direct reduction by electrons was mainly responsible for NFZ reduction at the GR-Ni foam electrode. Even after 18 cycles, the removal efficiency of NFZ still reached up to 98 % within 1 h. In addition, the cathodic degradation process could eliminate the antibacterial activity of NFZ. The GR-Ni foam electrode would have a great potential in electrochemical process for treating wastewater containing furan antibiotics

    Graphene-modified nickel foam electrode for cathodic degradation of nitrofuranzone: Kinetics, transformation products and toxicity

    Get PDF
    Simple, efficient, and durable electrodes are highly demanded for practical electrochemical process. In this study, a reduced graphene oxide modified nickel foam electrode (GR-Ni foam) was facilely prepared via one-step cyclic voltammetry electrodeposition of graphene oxide suspension onto the Ni foam. The electrochemical degradation of nitrofuranzone (NFZ, a kind of typical antibiotics) was studied on the GR-Ni foam cathode. The cyclic voltammetry and electrochemical impedance spectra analysis confirmed that presence of GR loading accelerated the electron transfer from the cathode surface to NFZ. With the applied cathode potential of −1.25 V (vs. Ag/AgCl), the removal efficiency of NFZ (C0 = 20 mg L−1) at the GR-Ni foam electrode reached up to 99 % within 30 min, showing a higher reaction rate constant (0.1297 min−1) than 0.0870 min−1 at the Pd-Ni foam and 0.0186 min−1 at the Ni foam electrode. It was also found that the pH, dissolved oxygen and NFZ initial concentration have slight effect on NFZ degradation at the GR-Ni foam electrode. The reactions first occurred at nitro groups (-NO2), unsaturated C=N bonds and N-N bonds to generate furan ring-containing products, and then these products were transformed into linear diamine products. The direct reduction by electrons was mainly responsible for NFZ reduction at the GR-Ni foam electrode. Even after 18 cycles, the removal efficiency of NFZ still reached up to 98 % within 1 h. In addition, the cathodic degradation process could eliminate the antibacterial activity of NFZ. The GR-Ni foam electrode would have a great potential in electrochemical process for treating wastewater containing furan antibiotics

    Molecular role of GATA binding protein 4 (GATA-4) in hyperglycemia-induced reduction of cardiac contractility

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Diabetic cardiomyopathy, a diabetes-specific complication, refers to a disorder that eventually leads to left ventricular hypertrophy in addition to diastolic and systolic dysfunction. In recent studies, hyperglycemia-induced reactive oxygen species (ROS) in cardiomyocytes have been linked to diabetic cardiomyopathy. GATA binding protein 4 (GATA-4) regulates the expression of many cardio-structural genes including cardiac troponin-I (cTnI).</p> <p>Methods</p> <p>Streptozotocin-induced diabetic rats and H9c2 embryonic rat cardiomyocytes treated with a high concentration of glucose (a D-glucose concentration of 30 mM was used and cells were cultured for 24 hr) were used to examine the effect of hyperglycemia on GATA-4 accumulation in the nucleus. cTnI expression was found to be linked to cardiac tonic dysfunction, and we evaluated the expression levels of cTnI and GATA-4 by Western blot analysis.</p> <p>Results</p> <p>Cardiac output was lowered in STZ-induced diabetic rats. In addition, higher expressions of cardiac troponin I (cTnI) and phosphorylated GATA-4 were identified in these rats by Western blotting. The changes were reversed by treatment with insulin or phlorizin after correction of the blood sugar level. In H9c2 cells, ROS production owing to the high glucose concentration increased the expression of cTnI and GATA-4 phosphorylation. However, hyperglycemia failed to increase the expression of cTnI when GATA-4 was silenced by small interfering RNA (siRNA) in H9c2 cells. Otherwise, activation of ERK is known to be a signal for phosphorylation of serine105 in GATA-4 to increase the DNA binding ability of this transcription factor. Moreover, GSK3β could directly interact with GATA-4 to cause GATA-4 to be exported from the nucleus. GATA-4 nuclear translocation and GSK3β ser9 phosphorylation were both elevated by a high glucose concentration in H9c2 cells. These changes were reversed by tiron (ROS scavenger), PD98059 (MEK/ERK inhibitor), or siRNA of GATA-4. Cell contractility measurement also indicated that the high glucose concentration decreased the contractility of H9c2 cells, and this was reduced by siRNA of GATA-4.</p> <p>Conclusions</p> <p>Hyperglycemia can cause systolic dysfunction and a higher expression of cTnI in cardiomyocytes through ROS, enhancing MEK/ERK-induced GATA-4 phosphorylation and accumulation in the cell nucleus.</p

    The effect of adding a home program to weekly institutional-based therapy for children with undefined developmental delay: A pilot randomized clinical trial

    Get PDF
    AbstractBackgroundEarly rehabilitation for children with developmental delay without a defined etiology have included home and clinic programs, but no comparisons have been made and efficacy is uncertain. We compared a weekly visit for institutional-based therapy (IT) to IT plus a structured home activity program (HAP).MethodsSeventy children who were diagnosed with motor or global developmental delay (ages 6-48 months and mean developmental age 12.5 months) without defined etiology were recruited (including 45 males and 23 females). The outcomes included the comprehensive developmental inventory for infants and toddlers test and the pediatric evaluation of disability inventory.ResultsChildren who received only IT improved in developmental level by 2.11 months compared with 3.11 months for those who received a combination of IT and HAP (p = 0.000). On all domains of the comprehensive developmental inventory for infants and toddlers test, except for self-help, children who participated in HAP showed greater improvements, including in cognition (p = 0.015), language (p = 0.010), motor (p = 0.000), and social (p = 0.038) domains. Except on the subdomain of self-care with caregiver assistance, the HAP group showed greater improvement in all the pediatric evaluation of disability inventory subdomains (p < 0.05).ConclusionEarly intervention programs are helpful for these children, and the addition of structured home activity programs may augment the effects on developmental progression

    A compact ka-band active integrated antenna with a GaAs amplifier in a ceramic package

    Get PDF
    This letter presents the design of a Ka-band active integrated antenna in package (AIAiP). A monolithic microwave integrated circuit amplifier based on the GaAs process and a compact patch antenna based on the printed circuit board process are implemented, respectively. Then, the amplifier and antenna are assembled together in a specified package using the wire-bond process. Thus, compared to the traditional solutions, the transmission loss and the size of the proposed AIAiP are significantly reduced. Furthermore, the influence of the bonding wire and the package is taken into account in the design of the amplifier and the antenna, respectively. A good agreement between the simulation and measurement results can be observed. The proposed AIAiP occupies a compact size of 7 × 7 mm2. Meanwhile, it achieves -10-dB impedance bandwidth from 33.4 to 37.2 GHz and a peak gain of 18.9 dBi at 35 GHz. Additionally, the impact of the package size on the antenna performance has been demonstrated for future AIA designers

    Increase of ATP-sensitive potassium (KATP) channels in the heart of type-1 diabetic rats

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>An impairment of cardiovascular function in streptozotocin (STZ)-diabetic rats has been mentioned within 5 days-to-3 months of induction. ATP-sensitive potassium (K<sub>ATP</sub>) channels are expressed on cardiac sarcolemmal membranes. It is highly responsive to metabolic fluctuations and can have effects on cardiac contractility. The present study attempted to clarify the changes of cardiac K<sub>ATP </sub>channels in diabetic disorders.</p> <p>Methods</p> <p>Streptozotocin-induced diabetic rats and neonatal rat cardiomyocytes treated with a high concentration of glucose (a D-glucose concentration of 30 mM was used and cells were cultured for 24 hr) were used to examine the effect of hyperglycemia on cardiac function and the expression of K<sub>ATP </sub>channels. K<sub>ATP </sub>channels expression was found to be linked to cardiac tonic dysfunction, and we evaluated the expression levels of K<sub>ATP </sub>channels by Western blot and Northern blot analysis.</p> <p>Results</p> <p>The result shows diazoxide produced a marked reduction of heart rate in control group. Furthermore, the methods of Northern blotting and Western blotting were employed to identify the gene expression of K<sub>ATP </sub>channel. Two subunits of cardiac K<sub>ATP </sub>channel (SUR2A and kir 6.2) were purchased as indicators and showed significantly decreased in both diabetic rats and high glucose treated rat cardiac myocytes. Correction of hyperglycemia by insulin or phlorizin restored the gene expression of cardiac K<sub>ATP </sub>in these diabetic rats.</p> <p>Conclusions</p> <p>Both mRNA and protein expression of cardiac K<sub>ATP </sub>channels are decreased in diabetic rats induced by STZ for 8 weeks. This phenomenon leads to result in desensitization of some K<sub>ATP </sub>channel drugs.</p
    • …
    corecore