Effects of nano-silver impregnation on brittleness, physical and mechanical properties of heat-treated hardwoods   总被引：1，自引：1，他引：0  

Hamid Reza Taghiyari  Aliakbar Enayati  Hadi Gholamiyan 《Wood Science and Technology》2013,47(3):467-480

The present study investigates the effect of heat treatment of untreated and nano-silver-impregnated Populus nigra, Populus deltoides and Fagus orientalis on the physical and mechanical properties. Specimens were impregnated with a 200-ppm aqueous silver nanoparticles suspension. Heat treatment was carried out at temperatures of 135 ± 3 °C and 185 ± 3 °C. Nano-silver impregnation aggravated the effects of heat treatment. Although significant in some cases, nano-silver impregnation did not seem to have great effect on physical properties. It may be concluded that although NS impregnation aggravated the effects of heat treatment on solid woods, other factors may also be involved such as the species and density of the wood.  相似文献   

Homocysteine Induces Heme Oxygenase-1 Expression via Transcription Factor Nrf2 Activation in HepG2 Cells     

Monireh Mani  Taghi Golmohammadi  Shahnaz Khaghani  Zahra Zamani  Kayhan Azadmanesh  Reza Meshkani  Parvin Pasalar 《Iranian Biomedical Journal》2013,17(2):93-100

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Bone Marrow Stromal Cell Transdifferentiation into Oligodendrocyte-Like Cells Using Triiodothyronine as a Inducer with Expression of Platelet-Derived Growth Factor α as a Maturity Marker     

Hojjat-Allah Abbaszadeh  Taki Tiraihi  Ali Reza Delshad  Majid Saghedi Zadeh  Taher Taheri 《Iranian Biomedical Journal》2013,17(2):62-70

Background: The present study investigated the functional maturity of oligodendrocyte derived from rat bone marrow stromal cells (BMSC). Methods: The BMSC were isolated from female Sprague-Dawley rats and evaluated for different markers, such as fibronectin, CD106, CD90, Oct-4 and CD45. Transdifferentiation of OLC from BMSC was obtained by exposing the BMSC to DMSO and 1 µM all-trans-retinoic acid during the pre-induction stage and then induced by heregulin (HRG), platelet-derived growth factor AA (PDGFR-α), fibroblast growth factor and T3. The neuroprogenitor cells (NPC) were evaluated for nestin, neurofilament 68, neurofilament 160 and glial fibrillary acidic protein gene expression using immunocytochemistry. The OLC were assessed by immunocytochemistry for O4, oligo2, O1 and MBP marker and gene expression of PDGFR-α was examined by RT-PCR. Results: Our results showed that the fibronectin, CD106, CD90, CD45 and Oct-4 were expressed after the fourth passage. Also, the yield of OLC differentiation was about 71% when using the O1, O4 and oligo2 markers. Likewise, the expression of PDGFR-α in pre-oligodendrocytes was noticed, while MBP expression was detected in oligodendrocyte after 6 days of the induction. Conclusion: The conclusion of the study showed that BMSC can be induced to transdifferentiate into mature OLC. Key Words: Bone marrow stromal cell, Triiodothyronine, Platelet-derived growth factor α  相似文献   

Synthesis and characterization of nanocrystalline CoWO4@silk fibers with antibacterial activity under ultrasound irradiation     

Azadeh Azadbakht  Amir Reza Abbasi  Nourolah Noori  Ezzat Rafiee  Mojtaba Taran 《Fibers and Polymers》2013,14(4):687-692

The present investigation reports the novel synthesis of CoWO₄ nanoparticles@silk fiber under ultrasound irradiation. The effect of temperature, power of ultrasound irradiation and sequential dipping steps in growth of the CoWO₄ particles were studied. Results show a decrease in the particles size as the temperature and power of irradiation decreased. The fibers containing CoWO₄ nanoparticles were tested for their antibacterial efficacy against E. coli and S. aureus and were found to possess significant antibacterial activity. The results show the CoWO₄ nanoparticles@silk with strongest fluorescence characteristics can be obtained in this method. The physicochemical properties of the nanoparticles were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectroscopy.  相似文献   

Accumulation of heavy metal in Platanus orientalis, Robinia pseudoacacia and Fraxinus rotundifolia     

Sajjad Hosseinzadeh Monfared  Mohammad Matinizadeh  Anoushirvan Shirvany  Ghavamedin Zahedi Amiri  Reza Mousavi Fard  Fariba Rostami 《林业研究》2013,24(2):391-395

Plants are capable of reducing environmental pollutions through uptaking contaminants in their tissues. In the study site, twenty one-year-old leaves and shoots as well as twenty soil samples were sampled and analyzed by Inductively Coupled Plasma (ICP). We investigated the uptaking ability of lead (Pb) and cadmium (Cd) by the leaves and shoots of Platanus orientalis, Robinia pseudoacacia and Fraxinus rotundifolia in Karaj city, the western Tehran, Iran. We also evaluated the total metal accumulation capacity by using metal accumulation index (MAI). Results indicated that there was no significant difference in uptaking contents of Cd and Pb in the leaves among the trees. However accumulation of Cd in shoots of F. rotundifolia and R. pseudoacacia was significantly higher than that of P. orientalis. The accumulation of Pb in shoots of R. pseudoacacia was significantly higher than the other species. The amount of Pb in the soil of the study area was significantly higher than Cd. Concentrations of Cd and Pb in leaves of the three species are in the ranges of 2.4 2.7 mg Kg-1 and 7.1 14.4 mg Kg-1 , respectively. R. pseudoacacia had the highest MAI value for leaves (2.21) and F. rotundifolia had the highest MAI value for shoots (2.4).  相似文献   

Toxicity of three insecticides and tobacco extract against the fungus gnat, Lycoriella auripila and the economic injury level of the gnat on button mushroom     

Najmeh Shirvani-Farsani  Abbas Ali Zamani  Saeed Abbasi  Katayoon Kheradmand 《Journal of pest science》2013,86(3):591-597

Lycoriella auripila (Winnertz) (Diptera: Sciaridae) is one of the most frequently seen pests of cultivated mushrooms, Agaricus bisporus (Lange) Imbach. The effects of different concentrations of diazinon, imidacloprid and deltamethrin, and tobacco extract were tested against L. auripila on varieties 737 and A15 of button mushroom. Also, economic injury level (EIL) of fungus gnat was evaluated on variety 737. Different varieties of button mushroom were cultured and weight of harvested mushrooms was recorded to provide an estimate of yield loss. A linear regression analysis was used to determine the relationship between pest density and mushroom yield. Imidacloprid was the most effective insecticide against L. auripila on both varieties and caused 100 % control at the highest tested concentration. The lowest concentration of diazinon (500 ppm a.i.) increased pest emergence on 737 and A15. This is possibly due to the hormoligosis. Deltamethrin and tobacco extract were ineffective against fungus gnat between both varieties. High levels of adults of L. auripila were associated with significant reduction in mushroom yield. EIL were calculated according to the number of L. auripila required to cause the critical yield loss from the predictive model and by control costs, mushroom price, and the reduction of injury due to spraying by imidacloprid and diazinon. The lowest values of EIL were related to imidacloprid compared with diazinon. This is due to the different efficiency of these two insecticides, for it causes mortality in population of L. auripila. Based on this research, for the first time clear EILs are introduced to the button mushroom growers for treatment of L. auripila.  相似文献   

Investigation in early growth traits, litter size, and lamb survival in two Iranian fat-tailed sheep breeds     

Hadi Atashi  Jamshid Izadifard  Mohammad Javad Zamiri  Amir Akhlaghi 《Tropical animal health and production》2013,45(4):1051-1054

In the present study, 1,635 lambing records of Ghezel (n?=?766) and Mehraban (n?=?869) breeds were used to evaluate the early growth traits, litter size, and lamb survival in sheep reared in Fars Province, southern Iran, during a 5-year-long period. The least squares means (± SE) of lamb birth weight for Ghezel were 5.27 (±0.22), 5.02 (±0.22), and 3.98 (±0.23) kg for single males, single females, and twin lambs, respectively; whereas, the corresponding values for Mehraban were 4.39 (±0.18), 4.18 (±0.18), and 3.50 (±0.19) kg. The least squares means of pre-weaning lamb growth (gram per day) for Ghezel were 239 (±15), 218 (±15), and 181 (±16) for single males, single females, and twin lambs, respectively, and the corresponding values for Mehraban were 204 (±12), 187 (±12), and 156 (±13). Lambs from 2 year old ewes or younger were on average lighter at birth and at weaning and had a lower average daily gain than those from older ewes (P?<?0.05). The percentage of twin births increased from 1.1 and 1.3 % for ewes aged ≤ 2 years to 19 and 12 % for those aged ≥ 6 years old in Ghezel and Mehraban, respectively (P?<?0.05). The mean pre-weaning lamb mortality was 7.1 and 4.1 % for Ghezel and Mehraban, respectively.  相似文献   

Erratum to: Investigation on early growth traits, litter size, and lamb survival in two Iranian fat-tailed sheep breeds     

Hadi Atashi  Jamshid Izadifard  Mohammad Javad Zamiri  Amir Akhlaghi 《Tropical animal health and production》2013,45(4):1055-1055

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Current experimental models,assessment and dietary modulations of intestinal permeability in broiler chickens     

Saad Gilani  Peter V. Chrystal  Reza Barekatain 《动物营养（英文）》2021,7(3):801-811

Maintaining and optimising the intestinal barrier (IB) function in poultry has important implications for the health and performance of the birds. As a key aspect of the IB, intestinal permeability (IP) is mainly controlled by complex junctional proteins called tight junction proteins (TJ) that link enterocytes together. The disruption of TJ is associated with increased gut leakage with possible subsequent implications for bacterial translocation, intestinal inflammation, compromised health and performance of the birds. Despite considerable data being available for other species, research on IP in broiler chickens and in general avian species is still an understudied topic. This paper reviews the available literature with a specific focus on IP in broiler chickens with consideration given to practical factors affecting the IP, current assessment methods, markers and nutritional modulation of IP. Several experimental models to induce gut leakage are discussed including pathogens, rye-based diets, feed deprivation and stress-inducing agents such as exogenous glucocorticoids and heat stress. Although various markers including fluorescein isothiocyanate dextran, expression of TJ and bacterial translocation have been widely utilized to study IP, recent studies have identified a number of excreta biomarkers to evaluate intestinal integrity, in particular non-invasive IP. Although the research on various nutrients and feed additives to potentially modulate IP is still at an early stage, the most promising outcomes are anticipated for probiotics, prebiotics, amino acids and those feed ingredients, nutrients and additives with anti-inflammatory properties. Considerable research gaps are identified for the mechanistic mode of action of various nutrients to influence IP under different experimental models. The modulation of IP through various strategies (i.e. nutritional manipulation of diet) may be regarded as a new frontier for disease prevention and improving the health and performance of poultry particularly in an antibiotic-free production system.  相似文献   

Potassium fixation of some calcareous soils after short term extraction with different solutions     

Mahdi Najafi-Ghiri  Soodabeh Rezabigi  Sara Hosseini  Hamid Reza Boostani  Hamid Reza Owliaie 《Archives of Agronomy and Soil Science》2019,65(7):897-910

This investigation was done to determine the release of potassium (K) from five calcareous soils of southern Iran using 0.025 M CaCl₂, HCl and citric acid during six successive extractions and to study the K fixation capacity of the soils after K release experiment. Mineralogical study indicated that Vertisols and Mollisols were dominated with smectites; while other soils had illite, chlorite, palygorskite and smectite. Results indicated that citric acid extracted more K than CaCl₂ and HCl (137 vs. 111 and 113 mg kg^?1, respectively). The analysis of calcium (Ca), magnesium (Mg) and K concentrations in the solutions suggests that the exchange of K with soluble Ca and Mg (originated from dissolution of carbonates by acidic solutions) is the main mechanism of K release, but citrate is able to dissolve K-bearing minerals and release K in slightly calcareous soils. Soils with more illite released more K. Potassium fixation capacity of soils increased after extractions of soils with different extractants from 324 to 471 mg kg^?1, with no significant difference. It is suggested to apply more K fertilizers in K-depleted calcareous soils and use of different solutions for extracting K from soil minerals may be a temporary and short term solution.  相似文献