oalib

OALib Journal期刊

ISSN: 2333-9721

费用:99美元

投稿

匹配条件: “AR Shahverdi” ,找到相关结果约3303条。
列表显示的所有文章,均可免费获取
第1页/共3303条
每页显示
Fabrication of docetaxel surfaced Fe3O4 magnetite nanoparticles and their cytotoxicity on 4?T1 breast cancer cells
MH Yazdi, Z Najafi, MR Khorramizadeh, M Amini, AR Shahverdi
DARU Journal of Pharmaceutical Sciences , 2012, DOI: 10.1186/2008-2231-20-15
Abstract: Fe3O4 MNPs were synthesised by a chemical method and characterized by transmission electron microscopy and energy-dispersive spectroscopy techniques. In the next step, docetaxel-coated Fe3O4 MNPs were prepared, using percipitation method. The surface chemistry of docetaxel-coated Fe3O4 MNPs as well as their thermal decomposition characteristics were examined using fourier transform infrared spectroscopy and thermogravimetric analyzer equipment, respectively. The cytotoxicity assay was conducted on 4?T1 breast cancer carsinoma by MTT assay to evaluate the possible in vitro antiproliferative effects of docetaxel-coated Fe3O4 MNPs.During precipitation process, docetaxel molecules were precipitated on the surface of Fe3O4 MNPs by the ratio of 3:100 w/w which indicates that each milligram of coated Fe3O4 MNPs averagely contained 30?μg pure docetaxel compound. Docetaxel showed aniproliferative effects against mentioned cell line. The higestest concentartion of docetaxel (80?μg/ml) caused about 80% cell death. However, the results demostarted that much lower amounts of docetaxel will be needed in combination of Fe3O4 MNPs to produce the potent antiproliferative effect compared to docetaxel alone. Dose response cytotoxicity assay of docetaxel-coated Fe3O4 MNPs against 4?T1 breast cancer cells showed that lower amount of docetaxel (0.6?μg/ml) can exhibit higher cytotoxic effect against this cancer cell line (90% cell death).Today, side effects of anti cancer drugs are still considered as a major problem in chemotherapy of cancer diseases ([1]). In the recent years, new drug delivery systems have been developed to reduce the side effects of these drugs ([2-4]). These systems mainly include nanotubes ([5]), liposomes ([6]), dendrimers ([7]) and nanoparticles ([8]). The potential biomedical applications of Fe3O4 magnetite nanoparticles (MNPs) are well discussed in the literature ([9]). Due to their magnetic properties, these nanomaretials have recieved particular attention as p
Minimum inhibitory concentration of ciprofloxacin in combination with hexahydroquinoline derivatives against Staphylococcus aureus
M Yousefi,MR Pourmand,AR Shahverdi,M Amini
Tehran University Medical Journal , 2012,
Abstract: Background: Staphylococcus aureus is the most common pathogen responsible for skin and soft tissue infections worldwide. Methicillin-resistant S. aureus is a major cause of both nosocomial and community acquired infections. The emergence of antimicrobial-resistant S. aureus is of global concern. Fluoroquinolone antimicrobials including ciprofloxacin, levofloxacin, and moxifloxacin are used to treat skin and soft tissue infections due to S. aureus. Emergence of ciprofloxacin resistance has increased in community acquired methicillin-resistant S. aureus strains. The aim of this study was to evaluate the minimum inhibitory concentration of ciprofloxacin and hexahydroquino-line derivatives against methicillin- and ciprofloxacin-resistant S. aureus.Methods: Identification of S. aureus was performed by routine microbiological tests in the Department of Pathobiology in Winter 2012. The susceptibility of S. aureus strains to both methicillin and ciprofloxacin was examined by the Kirby-Bauer disk-diffusion method. The minimum inhibitory concentration of ciprofloxacin, hexahydroquinoline derivatives and their combination were separately determined by broth microdilution method against methicillin- and ciprofloxacin-resistant S. aureus.Results: The minimum inhibitory concentration of ciprofloxacin decreased in the presence of hexahydroquinolinein derivatives in comparison with ciprofloxacin alone.Conclusion: This study showed that hexahydroquinoline derivatives enhance the antibacterial effect of ciprofloxacin against methicillin- and ciprofloxacin-resistant S. aureus. Therefore, these derivatives could be used as inhibitors of antibiotic resistance in combination therapies. This enhancement may be related to the inhibitory effect of hexahydroquinoline derivatives on the expression of antibiotic efflux pump in the bacteria. However, the structural features of a fluoroquinolone that determine whether it is affected by efflux transporters are not fully defined.
Non-commuting graphs of nilpotent groups
Alireza Abdollahi,Hamid Shahverdi
Mathematics , 2013,
Abstract: Let $G$ be a non-abelian group and $Z(G)$ be the center of $G$. The non-commuting graph $\Gamma_G$ associated to $G$ is the graph whose vertex set is $G\setminus Z(G)$ and two distinct elements $x,y$ are adjacent if and only if $xy\neq yx$. We prove that if $G$ and $H$ are non-abelian nilpotent groups with irregular isomorphic non-commuting graphs, then $|G|=|H|$.
A Method for DMUs Classification in DEA
F. Rezai Balf,R. Shahverdi
International Journal of Applied Operational Research , 2011,
Abstract: In data envelopment analysis, anyone can do classification decision units with efficiency scores. It will be interesting if a method for classification of DMUs without regarding to efficiency score is obtained. So in this paper, the classification of Decision Making Units (DMUs) is done according to the additive model without being solved for obtaining scores efficiency. This is because it is known that the additive model is the simplest non-radial model in DEA. In fact, the classification of DMUs to a set of efficient, weak efficient, and inefficient units, based upon feasibility concept is done here. Especially, the models and theorems for this aim are presented. Keywords: Data Envelopment Analysis, Classification, Decision Making Units.
Evaluation of Internal Cracks and Collapse in Poplar Wood (Populus nigra) during a Conventional Drying Process with Ultrasonic Inspection
Saeid ESHAGHI,Hadi DASHTI,Mahdi SHAHVERDI
Notulae Scientia Biologicae , 2012,
Abstract: In this research, internal cracks and collapse of wood, formed during drying process, were measured using ultrasonic inspection. For this purpose, seven poplar (Populus nigra) small blocks were dried, according to a time-based schedule. Ultrasonic waves’ propagation velocity was measured at both parallel and perpendicular to grain directions, using Sylvatest ultrasound device, during kiln drying process. Results showed that in all dried blocks, waves’ propagation velocity in the parallel direction was higher than in the perpendicular direction to grain. Ultrasonic waves’ propagation test for non-destructive identification of internal cracks, which occurs in wood during drying process in the parallel direction, was more successful compared to the perpendicular direction. Using ultrasonic waves’ propagation test for detection of collapse that occurs in wood during drying process was not useful.
The Effect of Wood Knot as a Defect on Modulus of Elasticity (MOE) and Damping Correlation
Mohammad Ali HOSSEIN,Mahdi SHAHVERDI,Mehran ROOHNIA
Notulae Scientia Biologicae , 2011,
Abstract: This research was carried out to investigate the influence of knots on modulus of elasticity and on damping factor of vibration. Rectangular bars from Cupressus arizonica wood were used. Five individual trees were selected, and samples of 2*2*36 cm were cut and conditioned at 21°C and 65% relative humidity. Experiments based on free vibration and free-free bar method were performed and controlled in static bending test due to their modulus of elasticity. As expected, this kind of defect showed significant effects on modulus of elasticity, damping factor of vibration and FFT diagrams. A significant relation was observed between modulus of elasticity and damping factor between the two dynamic and static methods, but this relation decrease about 60% in knot-containing specimens. Modes of FFT spectrums of defect-free specimens were pick-like, symmetric specimens without any breaks, but the spectra of knot-containing samples spectrums were entirely asymmetric. Applying these diagrams in order to recognize the suitability or unsuitability of a piece of wood for specific applications, especially due to internal defects that are not visible, could be very important, and must be considered in future research.
Temperature Evolution in Poplar (Populus nigra) Tension Wood and Normal Wood during a Conventional Drying Process
Asghar TARMIAN,Amir SEPEHR,Mahdi SHAHVERDI
Notulae Scientia Biologicae , 2011,
Abstract: In this paper, temperature evolution through tension wood and normal wood in poplar (Populus nigra) under a convective drying condition was investigated. Flat-sawn boards with green dimensions 80×40×25 mm were dried at constant dry-bulb temperature of 60°C and relative humidity (RH) of 50% to a final moisture content of about 8%. They were coated on four surfaces using aluminum foil bonded with polyurethane (PU) glue to confine moisture movement along the board thickness. The measurement of board temperature was carried out at 2.5, 5, 7.5, 10 and 12.5 mm along the board thickness every 20 minutes by means of 1 mm-thermocouples. The pattern of temperature profile was observed to be almost similar for both tension wood and normal wood. However, a slightly steeper temperature gradient occurred in the normal wood compared to the tension wood. In both types of woods, the surface temperature rose progressively from the initial value to the dry-bulb temperature but the core temperature remained at an almost constant value as the wet-bulb temperature even at the end of drying.
Wood Anatomical Structure of Morus alba L. and Morus nigra L., Native to Iran
Elham KARAMI,Kambiz POURTAHMASI,Mahdi SHAHVERDI
Notulae Scientia Biologicae , 2010,
Abstract: Iran is a wast country with many different tree species. Among those there are two species of Morus genus including alba and nigra. Since long time ago, white mulberry’s wood (Morus alba) has been used for making musical instruments especially bowl shaped instruments in Iran.. In contrast, black mulberry’s wood (Morus nigra) has never been used for these types of applications. In order to investigate the possible replacement choices, this study has been carried out to investigate the anatomical differences and similarities between these two species. Wood samples of the two species have been collected from same site and microsections for light microscopic studies and maceration samples have been prepared. The anatomical characteristics were studied according to the IAWA List of Hardwoods. The most important similarities between them are: vessel solitary in short radial multiples or irregular clusters, fiber nonseptate, rays uniseriate and multiseriate type, paratracheal parenchyma, varying from vasicentric to aliform confluent, apotracheal as marginal bands, Rhombic crystals present in rays and sometimes in parenchyma. The main differences are: semi-ring porous distribution of vessels in M. alba, fewer number of vessels and presence of aliform parenchyma in M. nigra. Taking these results into consideration, the most important features of both species are similar and it could be recommended to use the nigra species as well as the alba for making musical instruments.
ESTABLISHING KILN DRYING SCHEDULE FOR POPLAR (P. ALBA) LUMBER OF 7 CM IN THICKNESS
Mahdi Shahverdi,Hadi Dashti,Mohammad Ali Hossein
BioResources , 2011,
Abstract: Poplar (Populus alba L.) lumber with a nominal thickness of 7 cm from the Taleghan region in Iran was dried through convective kiln drying and under three different programs of T5–D2 (Forest Product Laboratory proposed program for poplar), T5–D4, and T5–D6 in order to obtain the optimum kiln schedule so as to protect the wood quality at an appropriate level up to final moisture content of 12±2%. Subsequently, the intensities of warps, superficial and internal cracks occurrence, residual stresses, drying rate, and final moisture gradient were measured. Results revealed that due to low warping values, more homogeneous final moisture profile, fewer internal cracks, and absence of superficial cracks in the program T5–D2 compared to the other two (T5–D4 and T5–D6), this program can be recommended as an optimum program for poplar lumber drying at commercial scale from the Taleghan region. On the other hand and from an energy efficiency point of view, in comparison with the mild schedule (T5-D2), the severe schedule (T5-D6) by saving 456 h of drying time, reduced electricity consumption by 6156 KWh and was therefore found to be $ 240.08 more profitable in this trial.
Weed Population Response to Chickpea (Cicer arietinum L.) Variety, and Planting Date
S. K. Mousavi,P. Pezeshkpour,M. Shahverdi
Journal of Science and Technology of Agriculture and Natural Resources , 2007,
Abstract: The effects of Chickpea (Cicer arietinum L.) varieties, and sowing dates on weed interference were investigated in a 2-year (2002-3, and 2003-4 growing season) field experiment in Agricultural Research Station of Kohdasht in Lorestan Province. The experimental design was a randomized complete block in factorial arrangement with 3 replications. The experiment had 3 factors: weed interference at 2 levels (weed free, and weed infested throughout the total growing season), planting date at 3 levels (autumn, winter, and spring) and Chickpea varieties at 3 levels (ILC482, Hasham, and Greet). Weed density in autumn sowing plots was more than 3 and 7 times greater in autumn chickpea than in winter and spring sowing plots, respectively. Weed biomass in autumn sowing was 2.5 times as much as winter or spring sowing. Wild safflower and volunteer barley were the most frequent among the weed species. Volunteer barley was mainly present in autumn and winter planting dates. Wild safflower was among the weed species that in addition to competition, caused much difficulty to chickpea harvesting. Based on the hyperbolic curve fitted to the data, Chickpea maximum biomass reduction due to weed competition was estimated to be 91.8 %.
第1页/共3303条
每页显示


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.