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MULTI- DIMENSIONAL LAPLACE TRANSFORM FOR NON - HOMOGENOUS PARTIAL DIFFERENTIAL EQUATIONS
A. Aghili Aghili,A. Motahhari
Journal of Global Research in Mathematical Archives , 2013,
Abstract: In this work, we implement multi-dimensional Laplace transform method for solving the non – homogenous second order partial differential equations. The results reveal that the Laplace transforms method is very convenient and effective. Key words and Phrases: Two-dimensional Laplace transforms; Heat equation; second order linear differential equations; Wave equation. Mathematics Subject Classification2010: Primary 44A30, Secondary 35L05
An in-vitro comparison of visual inspection, bite-wing radiography, and laser fluorescence methods for the diagnosis of occlusal caries
Pourhashemi S,Jafari A,Motahhari P,Panjnoosh M
Journal of the Indian Society of Pedodontics and Preventive Dentistry , 2009,
Abstract: Purpose: The purpose of this study was to compare accuracy and reproducibility of visual inspection (VI), bitewing (BW) radiography, and laser fluorescence (LF, DIANOdent) methods in the diagnosis of occlusal caries. Materials and Methods: The study was done on 80 extracted permanent premolars that seem to be intact or with primary caries in fissures. Three trained dentist examined the teeth in four stages: VI, BW radiography, LF, and histologic examination. Sensitivity, specificity, positive and negative predictive values, and accuracy of all methods were calculated and compared. For the LF method, using ROC curve and counterpart points on it, we determined upper and lower limits and calculated the parameters. Results: The estimated accuracy was 58.9% for VI and 45.1% for BW radiography methods. Kappa coefficient for interexaminer reproducibility was 57% and 34.1% in VI and BW radiography, respectively. Inter- and intraexaminer reproducibility coefficients of LF methods were 78.4% and 83.6%, respectively. The mean intraexaminer reproducibility coefficient in the VI method was 61.2%. Conclusion: Although accuracy and reproducibility of the LF method were higher than those of the VI and BW radiography, it is better to use this method together with other methods to reduce diagnostic faults.
Histological evaluation of Accell Connexus and Bio-Oss on quality and rate of bone healing: a single blind experimental study on rabbit’s calvarium
A Khorsand,A A R Rasouli Ghahroudi,P Motahhari,M Rezaei Rad
Journal of Dentistry of Tehran University of Medical Sciences , 2012,
Abstract: Objective: The objective of this study was to evaluate the effect of Accell Connexus on the quality and rate of healing in experimental defects of rabbit calvarium compared to Bio-Oss .Materials and Methods: Twelve 2.5-3.5 kg weighing New Zealand white rabbits were used. Three defects (3×6 mm) were created in the cranium of the animals subsequently filled with Accell Connexus , Bio-Oss or served as controls. The animals were sacrificed four, six and eight weeks postoperatively and the histology blocks were studied in terms of inflammation, trabeculation thickness, bone type regeneration, foreign body and remained biomaterial by light microscope. The data were subject to Mann-Whitney U test.Results: Increased inflammatory reaction, foreign body reaction, delayed bone formation and lower rate of ossification were observed in DBM-filled defects compared to Bio-Oss or controls. However, no significant differences were observed in bone formation between Bio-Oss , Accell Connexus and control specimens in the three time intervals. Furthermore, no significant differences were noted between Bio-Oss and control groups.Conclusion: Accell Connexus showeda lower rate of ossification and bone healing compared to Bio-Oss or controlgroups.Other studies in this field seem necessary.
Optimal Extraction of Glycyrrhetinic Acid Froml icorice Root
Mitra Amani,Rahmat Sotudeh-Gharebagh Navid Mostoufi,Hosein A. Motahhari Kashani
Journal of Food Technology , 2013,
Abstract: Licorice is a self-propelling plant that has many applications in pharmaceutical and food industries. Glycyrrhiza glabra is a kind of licorice whose main active constituentis a triterpenoid saponin called glycyrrhizin. If ether bound of glycyrrhizin is broken,it would loss its sweet taste and converts to glycyrrhetinic acid which is used as ananti-inflammatory agent. In order to produce glycyrrhetinic acid, glycyrrhizin without isolation is hydrolyzed in an acidic medium to release glycyrrhetinic acid. After filtration, glycyrrhetinic acid is extracted from resulting cake by ethyl acetate. The extract is then evaporated and the resulting solution is acetylated to produce glycyrrhetinic acid acetate. The ester is then purified by hexane and hydrolyzed with sodium hydroxide to produce glycyrrhetinic acid. The glycyrrhetinic acid produced in this way is dissolved in methanol and decolorized by activated carbon. Finally, water is added to solution to precipitate white glycyrrhetinic acid, which is purified by crystallization in aqueous ethanol to yield the final purified product.
The effect of bevel angle on apical microleakage following the use of amalgam and MTA
Sharifian MR,Motahhari P,Shahsia S
Journal of Dental Medicine , 2006,
Abstract: Background and Aim: Achieving appropriate seal in canal obturation is the main goal of endodontic therapy. However, in some cases, it can not be obtained by non-surgical procedures alone. Retrograde surgery is one of the most common procedures in endodontics. Apical seal improvement can be obtained by root end filling and decreasing the root end resection angle (bevel angle). The aim of this study was to investigate the role of bevel angle on apical microleakage following the use of amalgam and MTA as root end filling materials. Materials and Methods: In this experimental study, 128 extracted human teeth were instrumented and obturated by lateral condensation technique. The teeth were divided into two groups and the apical root resection was performed by high speed fissure bur (one group perpendicular to the long axis of the teeth and the other 45 to the long axis. The 3 mm root end cavity was prepared by ultrasonic device. Each group was divided into two subgroups: One filled with amalgam and the other with MTA. Teeth were incubated for 72 h, covered by two layers of nail polish (except for apical 3mm) and submerged in methylene blue for 48 h. Teeth were washed under tap water and mesiodistally dissected by low speed disc. Dye penetration was evaluated by stereomicroscope. Data were analysed by two way ANOVA and Tukey tests with p<0.05 as the limit of significance. Results: The results showed that retrofill material type had a significant effect on microleakage and MTA was superior to amalgam in this respect. Bevel angle failed to show any significant effect on apical microleakage. Conclusion: Based on the results of this study, it seems that the use of MTA instead of amalgam in clinical practice can improve the success rate of endodontic surgery whereas the bevel angle can be determined based on the status of each individual case; However, increasing the bevel angle seems to increase microleakage due to exposure of more dentinal tubules.
Compound odontoma associated with an unerupted mandibular primary canine: A case report
Seraj B,Motahhari P,Fakhri M,Ahmadi R
Journal of Dental Medicine , 2007,
Abstract: Odontomas are benign tumors of odontogenic origin characterized by their slow growth. They are considered to be a common type of odontogenic tumor, but rarely occur in the primary dentition.The etiology of odontomas is unknown, although local trauma, infection and genetic factors have been suggested. Odontomas often cause disturbances in the eruption of teeth such as, impaction or delayed eruption, and retention of primary teeth and abnormalities in the position of teeth such as tipping or displacement of adjacent teeth. In this paper, a case of unerupted right mandibular primary cuspid in a 5 years old girl due to the presence of a compound odontoma is presented.
Histologic comparison of Bio-Oss and Neo-Oss in bone regeneration of experimental defects on rabbit calvarium
Paknejad M,Rokn AR,Motahhari P,Mirza Toloei R
Journal of Dental Medicine , 2006,
Abstract: Background and Aim: Several biomaterials have been presented for regeneration of intraosseous defects and Bio-Oss is one of the most accepted materials in this field. Neo-Oss may be the first and only regenerative material made in Iran which few studies have been published about it. The aim of this study was the histologic evaluation of Neo-Oss in comparison with Bio-Oss in experimental rabbit calvarial defects. Materials and Methods: This was an interventional in vivo study. After elevating muccoperiosteal flap 18 standard defects (3×6mm) in frontal & parietal bone were made by round bur on the calvarium of 6 New Zealand rabbits. Defects were randomly assigned to one of the following treatments: 1-No graft (control), 2-Bio-Oss graft 3-Neo-Oss graft. After 4 weeks the animals were killed and histologic sections prepared. The studied variables consisted of inflammation, type of regenerated bone, thickness of bony trabeculation and foreign body reaction. Data were analyzed by Friedman test with p<0.05 as the limit of significance. Results: The results showed that Bio-Oss was effective for bone regeneration. Inflammation (P= 0.026) and foreign body reaction (P= 0.002) in Neo-Oss was significantly more than Bio-Oss group. Thickness of terabecula in Neo-Oss group (66.7% thin) was significantly different from Bio-Oss (100% thick) and control group (50% thin 50% thick) (P= 0.006). In Neo-Oss group, granulation tissue containing giant cells was observed and the rate of resorption during 4 weeks was high. Conclusion: Based on the results of this study, the healing capacity of Neo-Oss in comparison with Bio-Oss is not acceptable.
A Comparative Investigation of Lead Sulfate and Lead Oxide Sulfate Study of Morphology and Thermal Decomposition  [PDF]
S. A. A. Sajadi
American Journal of Analytical Chemistry (AJAC) , 2011, DOI: 10.4236/ajac.2011.22024
Abstract: The compound lead oxide sulfate PbSO4.PbO was prepared in our laboratory. The Thermal behavior of PbSO4 was studied using techniques of Thermogravimetry under air atmosphere from 25 to 1200°C. The identity of both compounds was confirmed by XRD technique. Results obtained using both techniques support same decomposition stages for this compound. The electron microscopic investigations are made by SEM and TEM. The compound is characterized by XRD and the purity was determined by analytical Methods. Also a series of thermogravimetric analysis is made and the ideal condition is determined to convert this compound to pure lead oxide.
Metal ion-binding properties of L-glutamic acid and L-aspartic acid, a comparative investigation  [PDF]
S. A. A. Sajadi
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.22013
Abstract: A comparative research has been developed for acidity and stability constants of M(Glu)1, M(Asp)2 and M(Ttr)3 complexes, which have been determined by potentiometric pH titration. Depending on metal ion-binding properties, vital differences in building complex were observed. The present study indicates that in M(Ttr) com-plexes, metal ions are arranged to the carboxyl groups, but in M(Glu) and M(Asp), some metal ions are able to build chelate over amine groups. The results mentioned-above demonstrate that for some M(Glu) and M(Asp) complexes, the stability constants are also largely determined by the affinity of metal ions for amine group. This leads to a kind of selectivity of metal ions, and transfers them through building complexes accompanied with glutamate and aspartate. For heavy metal ions, this building complex helps the absorption and filtration of the blood plasma, and consequently, the excursion of heavy metal ions takes place. This is an important method in micro-dialysis. In this study the different as-pects of stabilization of metal ion complexes regarding to Irving-Williams sequence have been investigated.
Determining the Basaltic Sequence Using Seismic Reflection and Resistivity Methods  [PDF]
A. Alanezi, A. Qadrouh
Open Journal of Geology (OJG) , 2013, DOI: 10.4236/ojg.2013.32B004
Abstract:

This study was carried out in Harat Rahat (south of Almadinah Almonwarah) using seismic reflection and resistivity methods. The main objectives of this study are to determine the extent of the basaltic layer and to define the subsurface faults and fractures that could affect and control the groundwater movement in the study area. A 2D seismic profile was acquired and the result shows that the subsurface in the study area has a major fault. We obtained a well match when the seismic result was compared with drilled wells. As a complementary tool, the resistivity method was applied in order to detect the groundwater level. The results of the resistivity method showed that six distinct layers have been identified. The interpretation of these six layers show that the first three layers, the fourth layer, the fifth layer and the bottom of the section indicated various subsurface structures and lithologies; various basaltic layers, fractured basalt, weathered basement and fresh basaltic layers, respectively. It is obvious that the eventual success of geophysical surveys depend on the combination with other subsurface data sources in order to produce accurate maps.

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