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Search Results: 1 - 10 of 405 matches for " Ghasemibasir Hamidreza "
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Expression of basal and luminal cytokeratins in breast cancer and their correlation with clinicopathological prognostic variables
Mohammadizadeh Fereshteh,Naimi Azar,Rajabi Parvin,Ghasemibasir Hamidreza
Indian Journal of Medical Sciences , 2009,
Abstract: Background : Normal breast ducts contain at least 3 types of epithelial cells: luminal (glandular) cells, basal/myoepithelial cells and stem cells. Myoepithelial and luminal epithelia can be distinguished by their different cytokeratin expression patterns. The aim of this study is to evaluate the expression of some prognostic biomarkers (ER, PR and HER2), as well as histological grading and lymph node status in cytokeratin-based groups of breast cancer. Objective: To evaluate the correlation between expression of basal and luminal markers and hormonal receptors, HER2/neu, age, grade and lymph node status in breast-invasive ductal carcinoma. Materials and Methods : Sixty-seven formalin-fixed and paraffin-embedded breast cancer specimens (of invasive ductal carcinoma, ′NOS′ type) which had already been studied for ER, PR and HER2/neu were selected. Data concerning age, tumor grade and lymph node status were also obtained from archives. Expression of basal (CK5/6) and luminal (CK7) cytokeratins was detected by immunohistochemistry. Stained sections were classified according to the intensity of staining and the percentage of stained cells. Results : We categorized the cases into 3 distinct phenotype groups: pure luminal, basal phenotype and null. Pure basal, mixed basal and luminal groups were classified as expressing a basal phenotype. There was a significant difference in the ER and/or PR expression between those 3 groups and a significant association between ER and/or PR negativity and basal phenotype expression. There was no significant difference in HER2/neu expression, age of the patients, tumor grade and lymph node status between the 3 cytokeratin-based groups and no significant association between lymph node status and basal phenotype expression. Conclusion : We found that to gain a real association between basal phenotype and prognostic markers, we should use a cocktail or a panel of different biomarkers to correctly determine basal-like phenotype of breast cancers. This approach guarantees more concordance with gene expression-based studies.
Giant eccrine hidrocystoma of orbit
Fateme Eslami,Farhad Fazel,Hamidreza Ghasemibasir,Afsaneh Naderi Beni
Journal of Research in Medical Sciences , 2007,
Abstract: A 14- year-old girl who had an upper eyelid mass for 3 months (without any pain or other symptoms) was referred to us. The orbital CT-scan revealed a superomedial orbital mass and excisional biopsy reported a giant eccrine hidrocystoma. KEY WORDS: Eccrine, hidrocystoma, giant, orbit, eyelid.
Synthesis and Characterization of Copper Nanoparticles by Bis-(Acetylacetonato)-Copper (II) Using Nonionic Surfactants and the Effect of Their Structures on Nanoparticles Size and Yield  [PDF]
Hamidreza Kamrani
Open Journal of Inorganic Non-metallic Materials (OJINM) , 2018, DOI: 10.4236/ojinm.2018.82002
Abstract: Between all precursors of copper complex, bis-(acetylacetonato)-copper (II) and bis-oxalate copper (II) with very close structures are two of the best representatives for copper nanoparticles synthesis. In this research, only bis-(acetylacetonato)-copper (II) in presence of some effective non-ionic surfactants such as Triton X-100, Dodecylamine, Tween 80 and also triphenylphosphine as a reducing agent via thermal decomposition process was used for copper nanopaticles synthesis. Two shif-base E19 and E22 complexes were also used for the investigation of these kinds of shif-base complexes capabilities by this method as precursors and all results were compared with each other. Between all surfactants, Triton X-100 gave the best yield with the largest grains. The techniques used for characterization of copper nanoparticles were TEM, EDX, FT-IR and XRD. TG-DTA and CV were used for characterization of bis-(acetylacetonato)-copper (II) complex.
Fabrication and Studying the Mechanical Properties of A356 Alloy Reinforced with Al2O3-10% Vol. ZrO2 Nano-particles through Stir Casting  [PDF]
Mohsen Hajizamani, Hamidreza Baharvandi
Advances in Materials Physics and Chemistry (AMPC) , 2011, DOI: 10.4236/ampc.2011.12005
Abstract: Al2O3-ZrO2 with a high level of hardness and toughness is known as ceramic steel. Due to its unique properties it can be used as a reinforcement in fabrication of metal matrix composites. In this study, nanoparticles of Al2O3-10% ZrO2 with an average size of 80 nm were used to fabricate Al matrix composites containing 0.5, 1, 1.5 and 2 wt.% of the reinforcement. The fabrication route was stir casting at 850?C. There is no report about usage of this reinforcement in fabrication of composites in the literature. The microstructures of the as-cast composites were studied by scanning electron microscope (SEM). Density measurement, hardness and tensile properties were carried out to identify the mechanical properties of the composites. The results revealed that with increasing the reinforcement content, density decreased while yield, ultimate tensile strength and compressive strength increased. Also, hardness increased by increasing the reinforcement content up to 1 wt.% Al2O3-10% ZrO2 but it decreased in the samples containing higher amounts of reinforcement.
Training Based Channel Estimation in MIMO-OFDM Systems  [PDF]
Maryam Imani, Hamidreza Bakhshi
Communications and Network (CN) , 2012, DOI: 10.4236/cn.2012.41008
Abstract: OFDM combined with the MIMO technique has become a core and attractive technology in future wireless communication systems and can be used to both improve capacity and quality of mobile wireless systems. Accurate and efficient channel estimation plays a key role in MIMO-OFDM communication systems, which is typically realized by using pilot or training sequences by virtue of low complexity and considerable performance. In this paper, we discuss some methods for channel estimation based training symbols in MIMO-OFDM systems. The results confirm the superiority of the represented methods over the existing ones in terms of bandwidth efficiency and estimation error.
The Tight Bound for the Number of Pilots in Channel Estimation for OFDM Systems  [PDF]
Maryam Imani, Hamidreza Bakhshi
Communications and Network (CN) , 2012, DOI: 10.4236/cn.2012.42019
Abstract: Coherent detection in OFDM systems requires accurate channel state information (CSI) at the receiver. Channel estimation based on pilot-symbol-assisted transmissions provides a reliable way to obtain CSI. Use of pilot symbols for channel estimation, introduces overhead and it is desirable to keep the number of pilot symbols as minimum as possible. This paper introduces a new tight bound for the number of pilots in channel estimation using adaptive scheme in OFDM systems. We calculate the minimum number of necessary pilots using two approaches. The first approach for the number of pilots is obtained based on Doppler frequency shift estimation and the second approach is acquired based on channel length estimation using second order statistics of received signal. Finally we obtain the tight bound for the number of pilots using attained values.
Q Fever: An Old but Still a Poorly Understood Disease
Hamidreza Honarmand
Interdisciplinary Perspectives on Infectious Diseases , 2012, DOI: 10.1155/2012/131932
Abstract: Q fever is a bacterial infection affecting mainly the lungs, liver, and heart. It is found around the world and is caused by the bacteria Coxiella burnetii. The bacteria affects sheep, goats, cattle, dogs, cats, birds, rodents, and ticks. Infected animals shed this bacteria in birth products, feces, milk, and urine. Humans usually get Q fever by breathing in contaminated droplets released by infected animals and drinking raw milk. People at highest risk for this infection are farmers, laboratory workers, sheep and dairy workers, and veterinarians. Chronic Q fever develops in people who have been infected for more than 6 months. It usually takes about 20 days after exposure to the bacteria for symptoms to occur. Most cases are mild, yet some severe cases have been reported. Symptoms of acute Q fever may include: chest pain with breathing, cough, fever, headache, jaundice, muscle pains, and shortness of breath. Symptoms of chronic Q fever may include chills, fatigue, night sweats, prolonged fever, and shortness of breath. Q fever is diagnosed with a blood antibody test. The main treatment for the disease is with antibiotics. For acute Q fever, doxycycline is recommended. For chronic Q fever, a combination of doxycycline and hydroxychloroquine is often used long term. Complications are cirrhosis, hepatitis, encephalitis, endocarditis, pericarditis, myocarditis, interstitial pulmonary fibrosis, meningitis, and pneumonia. People at risk should always: carefully dispose of animal products that may be infected, disinfect any contaminated areas, and thoroughly wash their hands. Pasteurizing milk can also help prevent Q fever. 1. Introduction Q fever is a zoonosis caused by Coxiella burnetii, an obligate gram-negative intracellular bacterium. Most commonly reported in southern France and Australia, Q fever occurs worldwide. C. burnetii infects various hosts, including humans, ruminants (cattle, sheep, goats), and pets—and, in rare cases, reptiles, birds, and ticks. This bacterium is excreted in urine, milk, feces, and birth products. These products, especially the latter, contain large numbers of bacteria that become aerosolized after drying. C. burnetii is highly infectious, and only a few organisms can cause disease. Because of its sporelike-life cycle, C. burnetii can remain viable and virulent for months. Infection can be acquired via inhalation or skin contact, and direct exposure to a ruminant is not necessary for infection. Rare human-to-human transmissions involving exposure to the placenta of an infected woman and blood transfusions have been reported
Analytical Computation of Reluctance Synchronous Machine Inductances Under Different Eccentricity Faults
Hamidreza Akbari
PIER M , 2012, DOI: 10.2528/PIERM11102005
Abstract: In the previous works, based on winding function theory, the calculation of reluctance machine inductances is carried out using numerical integration or inexact analytical equations based on approximated Fourier series expansions of the inverse air gap function. In this paper, development in Fourier series of the inverse air gap function has not been used, but a closed form analytical equation is developed for inductances calculation. This leads to a very precise computation of the inductances of the faulted machine and more accurate results. Moreover, all space harmonics ignored by the Fourier series expansions of the inverse air gap function will be included in the model. Derived comprehensive equation allows calculating time varying inductances of reluctance machines with different static, dynamic and mixed eccentricities in the frame of a single program. Inductances obtained by the proposed method are compared to those obtained from FE results. A satisfactory match was found between them.
An Improved Analytical Model for Salient Pole Synchronous Machines Under General Eccentricity Fault
Hamidreza Akbari
PIER B , 2013, DOI: 10.2528/PIERB13010101
Abstract: This paper develops a more precise analytical model for calculating salient pole synchronous machine (SPSM) inductances in case of general eccentricity including static, dynamic and mixed eccentricities. The developed method is based on the modified winding function approach (MWFA) which accurately considers variable air gap function and leads to pure analytical expressions of inductances. Available analytical techniques, based on MWFA, approximate the air gap function and simplify the geometrical model of SPSM, whereas, in this study, the influence of the openings between the rotor salient poles has been taken into account by using an effective form of rotor pole shoes. Using this technique, flux fringing effect is considered. By taking into account machine geometry, type of windings connection and flux fringing effect, this method is able to model most of the important features of an eccentric SPSM. The developed analytical expressions can calculate time varying inductances of SPSMs with any eccentricity type and degree in the frame of a single program. Simulation results for static eccentricity are compared with experimental tests on a laboratory generator to verify accuracy of the proposed model.
Moving Toward Application-Oriented Research System
Hamidreza Moghimi
Iranian Journal of Pharmaceutical Research , 2003,
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