Search

In recent years, different studies carried out in experimental diabetes models suggest that zinc oxide nanoparticles (ZnONPs) can be good antidiabetic agents, this evidence was obtained from long-term treatments using repeated doses of zinc oxide nanoparticles. The goal of this work was to evaluate the acute effects during six hours post-administration of ZnONPs on glycemia in healthy and diabetic rats and to compare the effects of oral and intraperitoneal administration. For this study male Wistar rats were used and experimental diabetes was induced by streptozotocin-nicotinamide intraperitoneal administration. At short-term ZnONPs administration induced hyperglycemic response in healthy and diabetic rats, the effect was dose-dependent and administration route. The diabetic rats were more sensitive to ZnONPs effect. In conclusion, this study provides novel information about the acute effects of zinc oxide nanoparticles on the fasting glycemia in experimental diabetes in vivo model and healthy rats, these data are important for its future clinical applications.

In the present study, we studied the effect of streptozotocin-induced Type 1 diabetes on contractile properties of soleus muscle in female and young male rats. We hypothesized that the gender affects the contractile function in diabetic rats. Thirty-two Sprague-Dawley rats, male and female, three months old were divided into four groups: Female Non-Diabetic (FND), Female Diabetic (FD), Male Non-Diabetic (MND) and Male Diabetic (MD). Diabetes was induced by a single dose of 60 mg/kg body weight of streptozotocin in citrate buffer pH 4.5 by intraperitoneal route. At 4 weeks after of the dose animals were considered to be diabetic if they had glucose levels ≥20 mmol/L. Soleus muscle mass and twitch force were higher in MND than in FND; in male rats, the diabetes decreased the muscle mass in 34% and the twitch force decayed in 33%; while in diabetic females the muscle mass and twitch force decayed 15% and 10% respectively. Our results showed that the diabetes has gender-dependent effects on the muscle mass and maximal contractile force.

BACKGROUND The effect of pregnancy on skeletal muscle still has not been clearly established. The aim of the present study was to investigate the effect of pregnancy on muscle weight and contractile properties of soleus and plantaris muscles. METHODS The female Sprague-Dawley rats were divided into two groups: nonpregnant (NP, 250 ± 4 g, n = 8) and late-pregnant (LP, 305 ± 13 g, n = 8). The right plantaris and soleus muscles were liberated from the surrounding tissues. Each muscle was placed on setup to mechanical recording with electric stimulation. In the optimum length of each muscle were recorded single twitches, tetani and fatigue. RESULTS The weight and cross-sectional area of soleus and plantaris muscles from pregnant rats was increased respect to nonpregnant rats. The maximal twitch tension decreased in both muscles during pregnancy respect to nonpregnant group. The soleus muscle of LP group developed lesser tetanic tension than NP group. However, the plantaris muscle showed a different behavior: to lower frequencies (5-30 Hz) the NP group developed greater tetanic tension than LP group, and for higher frequencies (40-100 Hz), the LP group developed greater tetanic tension than NP group. Finally, the soleus muscle was more resistance to fatigue than plantaris muscle in pregnant rats. CONCLUSION The fast and slow skeletal muscles show a differential contractile response during pregnancy, in tetanic tension and fatigue (Fig. 4, Ref. 48).

We performed a theoretical analysis of the systems formed by Pb/PbS with one or two molecule(s) of triethanolamine as a complexing agent. Conformational analysis, geometry optimizations and frequency calculations at the MP2/LANL2DZ level of theory were performed to check the isomer stabilities.

In this paper, we report experimental results on laser beam guiding by a self-tightening lattice photo induced in a strontium barium niobate (SBN) photorefractive crystal. In such setting, optical lattice (or periodical array of strongly-coupled waveguides) gradually transforms into array of weakly coupled ones. Experimental data are supported by computer simulation, which revealed crucial role of induced modulation instability in the strong laser beam guiding.

Experimental evidence of the cnoidal waves self-compression in photorefractive BTO crystal with drift nonlinearity is reported. The self-compression processes for a high voltages are limited by development of dynamic instability. Experimental data are supported by computer simulation.

We present experimental and theoretical results, which support the hypothesis that the photoinduced scattering in iron-doped lithium niobate crystals is due to the permanent amplification of nonstationary noise. The experiments that we present contradict the earlier suggested theory, which explains the noise as a three-wave mixing amplification process.

We use laser diffraction in the analysis of the transversal deformation that the papillary muscle of the female and male Wistar rat may undergo when is subjected to different tension (tension range, 0-30 mN) in the longitudinal plane. Papillary muscles from the right ventricle were illuminated at normal incidence with a He-Ne laser lasing at 594 nm at room temperature. The far-field diffraction pattern projected to a screen was recorded with a digital camera for its analysis. The analysis of the stress-strain curves from the two experimental groups shows that the papillary muscles from male rats exhibit a higher stiffness in the transversal axis compared to the female rats.

Two-wave mixing with a small angle between beams in a photorefractive crystal biased with an external electric field leads to the formation of additional non-Bragg orders and to wave amplification. A steady-state gain of 25 cm (-1) was obtained for an external voltage of 3 kV/cm in strontium barium niobate. Noise amplification and oscillation are also demonstrated.

In this work, we report on the fabrication and electrical characteristics of thin film transistors (TFTs) using chemically deposited cadmium sulfide (CdS) thin films as the semiconductor active layer in back-gated devices. The CdS thin films were deposited by the chemical bath deposition (CBD) technique using glycine as the complexing agent. The CdS layers were deposited on SiO2/Si-n substrates and lift-off was used to define the source and drain contacts (Au) on top of these layers. The Si-n wafer with a chromium-gold back contact served as the common gate for the transistors. Several devices with different channel lengths ranging from 10 to 80 μm were fabricated by this process. We studied the properties of the CdS layers deposited by this glycine-based CBD process and the electrical behavior of the transistors as a function of the channel length. The experimental results show that as-deposited CdS are n-type in character and devices exhibit typical pinch-off in drain current versus source–drain voltage (IDS–VDS) curves for several gate voltages. The values of the threshold voltage of the devices were in the range from 8.5 to 8.9 V, depending on the channel length. Channel mobility was between 4.3 and 5.2 cm 2 V −1 s −1 . This research implies that CdS TFTs produced by a simple and low-cost technique could be applicable to electronic devices. (Some figures in this article are in colour only in the electronic version)

We discuss a phase synthetic hologram, for encoding arbitrary complex fields, whose design is based on a sinusoidal phase grating with a spatially modulated phase depth. An important feature of the hologram is that it encodes the complex field at the zero diffraction order of the carrier grating. The smoothness of this sinusoidal carrier grating facilitates the implementation of the hologram with a pixelated spatial light modulator. We take advantage of the hologram reconstruction at the zero-diffraction order for the simultaneous generation of a collection of complex beams.

Interference fringes produced by the intersection of two plane waves in photorefractive strontium barium niobate crystal break in the transverse direction if the external electric field is high enough. For a certain relation between fringe spacing and nonlinearity strength, the tendency to regular pattern formation has been observed. We present a simple theory that qualitatively explains this effect.

We investigate theoretically the interaction of two or more beams intersecting at a small angle in a photorefractive crystal with a local type of holographic recording. All necessary diffraction orders are taken into account. It is shown that for photorefractive ferroelectrics the number of diffracted beams can be quite large. For negative nonlinearlity the high exponential gain previously predicted for three- or four-wave mixing does not exist if all diffraction orders are considered.