Antidiabetic Activity of Zinc Oxide and Silver Nanoparticles on Streptozotocin-Induced Diabetic Rats

The use of nanoparticles in medicine is an attractive proposition. In the present study, zinc oxide and silver nanoparticles were evaluated for their antidiabetic activity. Fifty male albino rats with weight 120 ± 20 and age 6 months were used. Animals were grouped as follows: control; did not receive any type of treatment, diabetic; received a single intraperitoneal dose of streptozotocin (100 mg/kg), diabetic + zinc oxide nanoparticles (ZnONPs), received single daily oral dose of 10 mg/kg ZnONPs in suspension, diabetic + silver nanoparticles (SNPs); received a single daily oral dose of SNP of 10 mg/kg in suspension and diabetic + insulin; received a single subcutaneous dose of 0.6 units/50 g body weight. Zinc oxide and silver nanoparticles induce a significant reduced blood glucose, higher serum insulin, higher glucokinase activity higher expression level of insulin, insulin receptor, GLUT-2 and glucokinase genes in diabetic rats treated with zinc oxide, silver nanoparticles and insulin. In conclusion, zinc oxide and sliver nanoparticles act as potent antidiabetic agents.     

Reducing the dose of gonadotrophin-releasing hormone agonist on starting ovarian stimulation: effect on ovarian response and in-vitro fertilization outcome

The aim of this study was to examine if lowering the dose of gonadotrophin-releasing hormone agonist (GnRHa) on starting ovarian stimulation could be beneficial in in-vitro fertilization (IVF) programmes. A total of 64 normally ovulating patients entering an IVF programme were randomized to receive GnRHa (nafarelin acetate/Synarel) as an intranasal spray commencing in the midluteal phase, either at a dosage of 200 microg three times daily until the day of human chorionic gonadotrophin (HCG) administration, or to be reduced to 200 microg twice daily as ovarian stimulation was initiated. Patients in both groups were below 35 years with a body mass index below 30. All patients received three ampoules of Metrodin HP per day. Blood samples were taken on the day of HCG administration to measure luteinizing hormone (LH), oestradiol, and progesterone. LH and oestradiol were found to be significantly higher in the lower Synarel dose group. Our results show that reducing the GnRHa dose during ovarian stimulation in IVF might be beneficial in terms of significantly more oocytes recovered, and significantly greater number of embryos available for transfer and freezing, with no incidence of premature luteinization.     

A New Access Control Solution for a Multi-Provider Wireless Environment

The fundamental goal in future 4G mobile multi-service networks is to provide an efficient mobile computing environment. We presume that future terminals will be equipped with multiple heterogeneous wireless interfaces. We want to enable each user to seamlessly move between different providers networks. Besides seamless roaming, a key consideration is also devoted to quality-of-service provision. In this article, we propose a model and an architectural framework for supporting quality of service in the context of interconnected multi-provider wireless systems. The proposed integrated COPS-based management and RADIUS-based access control architecture will allow providers to offer multimedia services while optimizing the use of the underlying network resources. We suggest new concepts and protocols to provide solutions to these challenges and describe the French national research project named MMQoS aiming on building such future networks.     

Gamma-Irradiation and Storage Effects on Some Chemical Aspects of Carrots

Studies on chemical changes induced by gamma-irradiation at optimum dose of 75 krad in carrots were undertaken. Sugars, nitrogen, free amino acids, amino acids of alcohol insoluble solids, and pectin fractions were determined. The results indicate that the postharvest irradiation of carrots does not dramatically affect their chemical composition during storage. However, it was observed that storage time affected significantly the biochemical changes occurring in the constituents of carrots exposed to gamma-irradiation.     

A study of excess loop delay in tunable continuous-time bandpass delta–sigma modulators using RC-resonators

Excess loop delay is one of the most critical non-idealities of continuous-time delta–sigma modulators as it leads to degradation of the signal-to-noise-ratio or even instability. A comprehensive study of the impact of excess loop delay on tunable continuous-time bandpass delta–sigma modulators using RC-resonators is performed in this paper, both analytically and by simulations. Moreover, a detailed analysis of the conventional compensation techniques for single-band continuous-time bandpass modulators as well as their adaptability to tunable bandpass modulators is performed. The results indicate that only tuning of the scaling coefficients is suitable to compensate for excess loop delay in high-speed tunable bandpass modulators. Based on this result, an approach to the compensation of excess loop delay is proposed which maps the poles of the noise transfer function (NFT) to almost ideal and thus stable positions. Excess loop delay equal to one clock cycle may thus be compensated while the available tuning range of the center frequency depends on the order and the out-of-band-gain of the NFT. A prototype implemented on a printed circuit board proves the feasibility of the proposed approach.     

Annealing effects on the structural and optical properties of growth ZnO thin films fabricated by pulsed laser deposition (PLD)

Annealed ZnO thin film at 300, 350, 400, 450 and 500 °C in air were deposited on glass substrate by using pulsed laser deposition. The effects of annealing temperature on the structural and optical properties of annealed ZnO thin films by grazing incident X-ray diffraction (GIXRD), transmittance spectra, and photoluminescence (PL) were investigated. The GIXRD reveal the presence of hexagonal wurtzite structure of ZnO with preferred orientation (002). The particle size is calculated using Debye–Scherrer equation and the average grain size were found to be in the range 5.22–10.61 ± 0.01 nm. The transmittance spectra demonstrate highly transparent nature of the films in visible region (>70 %). The calculation of optical band gap energy is found to be in the range 2.95–3.32 ± 0.01 eV. The PL spectra shows that the amorphous film gives a UV emission only and the annealed films produce UV, violet, blue and green emissions this indicates that the point defects increased as the amorphous film was annealed.     

Memory switching in amorphous Ge---Se---Tl chalcogenide semiconductor films

The switching effects in amorphous GeSe₂, GeSe₄, GeSe₂Tl and GeSe₄Tl thin films have been investigated. The observed switching phenimenon for these compositions was of the memory type. The threshold switching voltage was found to increase linearly with increasing film thickness (80–740 nm), while it decreased exponentially with increasing temperature (T < T_g).

The effect of adding thallium to both amorphous GeSe₂ and amorphous GeSe₄ results in decreasing the values of the threshold electric field, the activation energy of switching, as well as the thermal activation energy of conduction. The results obtained are explained in accordance with the electrothermal model of breakdown.     

Non-productive tool path optimisation for four-axis milling using the simulated annealing algorithm

The paper concerns the development of generic computer aided optimisation techniques for the minimisation of residence time of a multi-component pallet in a horizontal machining centre. A general methodology has been established to take a part program for a multi-faced pallet, that involves many components, typically 20–30, and tool changes, segment it to extract the position and machining conditions embedded in it, automatically re-sequence the machining operations to find the optimum total tool path, and regenerate a new part program with the optimised machining sequence. A range of case studies has been used to: validate the software, and to demonstrate its ability to minimise the total pallet residence time. The techniques developed can be used for semi-automatic part programming of the entire pallet with multi-components, and with an auto-selection multi-tool facility. The software is capable of achieving a large reduction in part programming time, as well as reducing the non-machining time. It is shown that the use of the optimisation package with a range of part programs reduces the total pallet residence time by a factor between 9.5 and 36%, and consequently has the potential to achieve considerable economic gains.