Showing papers by "Nima Naderi published in 2019"

Pectasol-C Modified Citrus Pectin targets Galectin-3-induced STAT3 activation and synergize paclitaxel cytotoxic effect on ovarian cancer spheroids.

Abstract: Here we sought to determine the relationship between STAT3 activity and Galectin-3 (Gal-3) and to investigate the cytotoxic effect of PectaSol-C Modified Citrus Pectin (Pect-MCP) as a specific competitive inhibitor of Galectin-3 (Gal-3) in combination with Paclitaxel (PTX) to kill the ovarian cancer cell SKOV-3 multicellular tumor spheroid (MCTS). To this order, SKOV-3 cells in 2D and 3D cultures were treated with exogenous Gal-3 for the assessment of STAT3 activity. Two-way ANOVA main effect and IC50 of each drug Paclitaxel (PTX) and Pect-MCP or in combination were obtained from MTT assay results. The phosphorylated STAT3 levels, migration, invasion, integrin mRNA and p-AKTser473 levels were assessed in the absence or presence of each drug alone or in combination. Gal-3 expression levels were assessed in human serous ovarian cancer (SOC) specimens and its correlation with different integrin mRNA levels was further assessed. Our results showed that Gal-3 expression level was significantly increased in MCTS compared to monolayer SKOV-3 cells which triggered STAT3 phosphorylation. Moreover, Pect-MCP synergized with PTX to kill SKOV3 MCTS through abrogation of STAT3 activity and reduced expression of its downstream target HIF-1α, reduced integrin mRNA levels, and subsequently decreased AKT activity. There were higher expression levels of Gal-3 in human high-grade SOC specimens compared to the normal ovary and borderline SOC which positively and significantly correlated with α5, β2 and β6 integrin mRNA levels. Together, these results revealed for the first time that Pect-MCP could be considered as a potential drug to enhance the PTX effect on ovarian cancer cells MCTS through inhibition of STAT3 activity.

Development and Optical Properties of ZnO Nanoflowers on Porous Silicon for Photovoltaic Applications

Abstract: In the present work, a comparison between zinc oxide (ZnO) nanoflowers and nanorods for photovoltaic applications is presented. Using chemical bath deposition technique, ZnO nanoflowers were grown on porous silicon (PS) while ZnO nanorods were deposited on flat Si substrate. The morphology of ZnO/PS sample indicated the formation of nanoflowers by accumulation of ZnO nanorods on PS walls. The structural studies indicated that ZnO nanoflowers experienced a stress relief compared to ZnO nanorods which was due to the role of porous substrate for accommodating the lattice strain in order to obtain the subsequent ZnO nanoflowers with reduced strain. The optical results obtained from ZnO nanoflowers showed more intense photoluminescence and Raman peaks compared with nanorods. It was due to the higher specific surface area of nanoflowers which led to a higher absorption coefficient and increased the generation of electron–hole pairs in this sample. Due to their elevated specific surface area, ZnO nanoflowers can capture the incident light and reduce the reflection coefficient of silicon substrates. Thus, they can be considered as an effective antireflective layer to improve the efficiency of solar cells. The optoelectrical results showed an improvement in the efficiency of fabricated solar cells by use of ZnO nanoflowers on PS structures when compared to the conventional ones possessing ZnO nanorods on flat silicon substrates. Development of ZnO nanoflowers on PS substrates can further extend the applications of ZnO nanostructures in photovoltaic devices.

Neuroprotective effects of lipopolysaccharide and naltrexone co‑preconditioning in the photothrombotic model of unilateral selective hippocampal ischemia in rat

Abstract: Preconditioning with lipopolysaccharide (LPS) or opioid antagonists has a neuroprotective effect in ischemic insults. However, the co‑preconditioning effect of toll‑like receptor ligands and opioid antagonists has not been investigated. In this study we examined the neuroprotective effect of LPS and naltrexone (NTX) preconditioning and co‑preconditioning in unilateral selective hippocampal ischemia in rats to assess for possible synergistic protective effects. LPS and NTX were injected unilaterally into the left cerebral ventricle of male rats. Forty‑eight hours after LPS and twenty‑four hours after NTX injection, ipsilateral selective hippocampal ischemia was induced using a modified version of the photothrombotic method. Protective effects for LPS and NTX were assessed by evaluating infarct volume (using 2,3,5‑triphenyltetrazolium chloride staining), and cognitive function (using radial arm water maze and passive avoidance tests). Animals in the ischemic group had an infarct lesion and considerable cognitive impairment, compared with the sham group. LPS or NTX preconditioning significantly reduced the infarct size and improved cognitive function. Moreover, co‑preconditioning with LPS and NTX increased the protective effect compared with preconditioning with LPS or NTX alone. Our data showed that LPS and NTX preconditioning resulted in a neuroprotective effect in hippocampal ischemia. Furthermore, co‑preconditioning with LPS and NTX resulted in a synergistic protective effect.

Substitution of corn silage with shredded beet pulp affects sorting behaviour and chewing activity of dairy cows.

Abstract: This study aims to evaluate the effects of substituting increasing concentrations of shredded beet pulp (SBP) for corn silage (CS) on nutrient intake, sorting index, intakes of particle size and nutrients, meal and rumination patterns, and chewing activity of dairy cows. Four multiparous (126 ± 13 day in milk) and 4 primiparous (121 ± 11 day in milk) Holstein cows were used in a 4 × 4 Latin square design experiment with 4 periods of 21 days. Dietary treatments were (DM basis): 16% of dietary DM as CS without SBP (0SBP); 8% CS and 8% SBP (8SBP); 4% CS and 12% SBP (12SBP); and 0% CS and 16% SBP (16SBP). We observed a reduction in the extent of sorting against long particles and medium particles but for fine particles with increasing SBP levels in the diets. The number of eating bouts per day was lesser (8.2%) in cows fed SBP diets compared with 0SBP cows and corresponded with a reduction in eating time per d across treatments. The number of ruminating bouts per day was similar across diets (16.8 bouts/day), but substituting SBP for CS in the diets tended to decrease linearly ruminating bout length (5 min/bout) and tended to increase ruminating bout interval (8 min/day). Eating, ruminating and total chewing time when expressed as minutes per kilogram of forage NDF intake and peNDF > 8 intake increased when SBP was substituted for CS in the diets. Primiparous cows had greater ruminating time (57 m/day) and total chewing time (73 min/day), eating rate (0.01 kg of DM/min) compared with multiparous cows. Also, increasing forage NDF and peNDF>8 , >8-mm DM intakes are effective means of stimulating ruminating and chewing activities. This study showed that SBP could partially replace CS and not affect DM intake, but chewing activity may decrease slightly.

Ultraviolet Detectors Based on Annealed Zinc Oxide Thin Films: Epitaxial Growth and Physical Characterizations

Abstract: In this report, ultraviolet (UV) detectors were fabricated based on zinc oxide thin films. The epitaxial growth of zinc oxide thin films was carried out on a bare glass substrate with a preferred orientation to (002) plane of wurtzite structure through radio frequency sputtering technique. The structural properties indicated a dominant peak at 2θ=34.28o, which was matched with JCPDS reference card No. 34-1451 and showed the wurtzite phase of deposited ZnO thin films. This peak showed the preferred orientation with the c-axis perpendicular to the surface. The crystallite size was estimated using the Scherrer equation as much as 44.5nm. The morphology of samples showed that pebble-shaped ZnO particles were covered on the entire substrate homogeneously. The results indicated the excellent optical properties in the visible-infrared region with high absorption in the UV spectrum. The extrapolated cut-off for the transmittance spectrum was at 373nm, which confirmed the calculated optical bandgap of this sample at 3.27eV. The optical properties showed that the deposited samples are suitable substrates for the fabrication of UV detectors. Two back-to-back Schottky contacts of Au were deposited on the ZnO substrate to fabricate UV detectors, and a metal-semiconductor-metal structure was designed. The optoelectrical properties of detectors were carried out using the measurement of current-voltage curves. The results indicated a high photosensitivity of 0.32 corresponding to the high performance of the fabricated device. Moreover, the device showed a short rise time of 0.40s and recovery time of 0.45s indicating the high speed of detection for fabricated UV detectors.