فهرست مطالب mousavi. n

Paleocene-Miocene sediments in the central part of the Gorgan Plain were studied to evaluate lithostratigraphy, biostratigraphy and reconstruction of the paleogeography of the South Caspian Basin (SCB). Based on nannofossils distribution in the studied interval, the following points were identified: Foram layers equivalent sediments have Thanetian –Eocene age and Upper Maykop- Diatom equivalent sediments have Middle-Late Miocene age. Evaluation of the nannofossils distribution in the studied interval has clarified a major unconformity between lower Paleocene-Eocene sediments and the upper Middle-late Miocene sediments. This unconformity is coincident with collisional event of the Afro-Arabia and Eurasia Plates and rising of the surrounding mountain ranges around the Caspian Basin including Alborz and Kopet-Dagh Mountains. Nannofossils distribution of the studied succession displays that the SCB was connected to the Black Sea and Mediterranean Basin in the lower Middle Miocene and was isolated in the Middle-Late Miocene. The interpreted east-west running seismic lines displays a clear increase in the sediment thickness and accommodation space from eastern to western part of the Gorgan Plain. The higher available accommodation space from east to west of the Gorgan Plain led to a delay in the subaerial exposure in the western part of the Gorgan Plain due to rising of the Kopet-Dagh and Alborz Ranges. This interpretation is consistent with the lack of the Paleocene-Eocene sediments and presence of the Cretaceous sediments below the major unconformity in the eastern part of the Gorgan Plain and presence of the Paleocene-Eocene sediment below the unconformity in the studied area.   

One of the problems of all ceramic restorations is their risk of fracture due to occlusal loads. The aim of the present study was to compare the effect of two marginal designs (shoulder and chamfer) on the fracture resistance of IPS-emax all ceramic restorations. One extracted maxillary first premolar received chamfer 50' marginal preparation (0.8 mm). Twenty impressions were made using poly vinyl siloxane. Then, chamfer was converted to shoulder 90'(1mm). After impression, epoxy resin dies were fabricated. Impressions of each epoxy resin die were made and poured with die stone. Twenty Press crowns and twenty ZirCAD crowns were made on stone dies and cemented on resin dies. Then, samples underwent a fracture test in a universal testing machine. Data were analyzed by one-way ANOVA. The mean fracture resistance was 1426N for the chamfer ZirCAD samples, 1361.3N for the shoulder ZirCAD samples, 1059.9N for the chamfer Press samples and 1295.8N for the shoulder Press samples. One-way ANOVA revealed no difference among groups. (p=0.095). After porcelain application, marginal design does not affect fracture resistance of single IPS-emax posterior crowns. Fracture resistance was approximately the same in Press and ZirPress groups probably due to porcelain application, because in ZirCAD group fractures occurred in the porcelain prior to the core.

Demand for implant supported overdentures has increased due to the problems of conventional dentures. Despite the high success rate of implants, implant failure remains a major challenge. Implant overload can cause cortical bone loss and implant failure. Using finite element analysis, this study aimed to find the best design and type of attachments causing minimum stress in the alveolar bone. The geometrical model of the mandible was produced using computed tomography (CT) data and three ITI implants were placed in the midline and the location of the first premolar teeth. All conditions were simulated using finite element software. Three bar-ball, bar and ball attachments were considered to support the overdenture. Maximum von Mises stress was calculated in the supporting bone in different overdenture designs. The results showed that the greatest amount of stress in bone was around the upper thread and the neck of the implant. The ball and the bar-ball attachments applied the most and the least amount of stress to the bone around the implant, respectively. Maximum stress was applied to the ball attachment in the bar-ball design. The maximum amount of movement was in bar-ball attachment. The bar-design decreased the stability of overdenture, as well as the stress in the peri-implant bone. Ball design increased concentration of stress in bone around the implant and increased the stability of overdenture.

Enamel wear is among the main disadvantages of ceramic restorations. Recently, use of full zirconia crowns without dental porcelain has been suggested. The aim of this study was to compare the effect of feldspathic porcelain and zirconia on the wear of natural teeth. In this experimental study, 22 zirconia specimens were fabricated; out of which, 11 specimens were polished and chosen as zirconia specimens while the remaining 11 were used to fabricate porcelain specimens. A total of 22 natural human teeth were also obtained. The natural teeth were photographed by a stereomicroscope in a fixed position and the distance from the cusp tip to a reference point was measured. Next, 11 teeth opposed zirconia and the remaining 11 opposed porcelain specimens in a chewing simulator and subjected to 120,000 masticatory cycles. The teeth were photographed again and the greatest difference between the before and after values ​​ was recorded. The mean (± standard deviation) wear rate was 153.8±95.68 and 306.3±127.74, in the zirconia and porcelain groups, respectively; and the two groups had a statistically significant difference in this respect (P=0.007). The mean wear was significantly lower in teeth opposing zirconia than in those opposing feldspathic porcelain.

Hereditary persistence of fetal hemoglobin (HPFH) and δβ-thalassemia are heterogeneous disorders characterized by elevated levels of fetal hemoglobin (Hb F). Deletional mutations are responsible for the disease and are not recognized by routine hematological tests. The aim of this study was to perform a molecular characterization of beta globin gene cluster deletions in anemic patients referred to the genetic laboratory of Amirkola children hospital. In this cross sectional study, thirty patients (14 females and 16 males) with mild microcytic hypochromic anemia with hematologic index (MCV<80 fl, MCH<27 pg, variable HbA2 and high level of Hb F) were tested for the 3 common delta beta deletional mutations: Sicilian δβ-thalassemia, Asian-lndian inversion-deletion γδβ-thalssemia and hemoglobin Lepore using Gap-PCR technique. Sicilian, Asian-lndian γδβ-thalssemia deletions as well as the Hb Lepore were found respectively in 6 (20%), 6 (20%) and 1 (3.33%) patients and 17 cases remained uncharacterized. Regarding the presence of different forms of deletion in beta globin gene cluster in this region, molecular characterization of these mutations is important in at risk couples presenting microcytic anemia and should be considered in premarital screening and prenatal diagnosis centers for a more efficient thalassemia major prevention program.

This study was conducted to investigate the toxicity of Titanium Oxide (TiO2) and Zinc Oxide (ZnO) nanoparticles as two of most widely used nanoparticles. The result of this study can help to designing environmental standard and legislations for nanoparticles. Different concentrations of nano ZnO and TiO2 nanoparticles were added to nutrient Agar culture media. Then, definite numbers of Escherichia coli and Staphylococcus aureus bacteria were added to culture media and inhibition of these bacteria growth was measured in comparison to controls. Obtained data were analyzed to determine nanoparticles’ EC50 and NOEC (No Observed Effect Concentration) using SPSS ver.16 and Probit standard test. 24-hours EC50 of nano ZnO using E. coli and S. aureus determined to be 5.47 mg/L and 2.38 mg/L respectively. In addition, 24-hours EC50 of nano TiO2 using E. coli and S. aureus determined to be 5366 mg/L and 3471 mg/L respectively. In the case of ZnO nanoparticles, no observed effect concentration determined to be 1.15 and 3.28 mg/L for E. coli and S. aureus respectively and in the case of TiO2 nanoparticles no observed effect level determined to be 1937 and 1184 mg/L for E. coli and S. aureus respectively. This study showed that acute toxicity of nano ZnO is by farmore than that of nano TiO2. Regarding the EPA acute toxicity criteria, nano ZnO is categorized as moderately toxic and nano TiO2 is categorized as practically non toxic. Hence, regarding the acute toxicity, in recommending exposure criteria and environmental disposal standards, compared to nano TiO2, nano ZnO requires more attention.

In recent years، there has been a growing interest in the interrelationships among obsessive- compulsive disorder، impulsivity، and serotonin and previous studies produced mixed results. This study aimed at investigating the comparison of impulsivity between responsive and non-responsive obsessive-compulsive patients to selective serotonin reuptake inhibitors (SSRIs). Subjects and In an ex post facto design، using Sadock and Sadock''s (2007) definition، and through convenience sampling، 27 Obsessive-Compulsive patients were divided into two groups (responsive and non-responsive to SSRI) and were examined through 11th Barratt Impulsivity Scale، Yale-Brown Obsessive-Compulsive Scale (symptom checklist)، and Structured Clinical Interview for DSM-IV. The mean scores of impulsivity and its components in responsive patients were higher in comparison with non responsive ones. Centroids of responsive and non responsive groups were significantly different regarding impulsivity، attentional، motor، and non-planning impulsiveness (p< 0. 009). Among the four variables، there were significant differences only in impulsivity (p<0. 01)، attention (p< 0. 01) and impulsiveness between responsive and non responsive groups (p <0. 05). The findings of this research shows that there is a significant difference in impulsivity level between responsive and non-responsive obsessive-compulsive patients to SSRIs، and the mean score of impulsivity in non-responsive patients is higher. However، attending to some paradoxes in the literature، more researches are needed to provide a comprehensive theoretical explanation for the interrelationships among impulsivity،OCD، and responsivity to SSRIs.

Pyrethroid-impregnated bednets have been shown to be one of the most promising tools that have emerged in recent years to control malaria. Mosquitoes may be physically irritated by pyrethyroids, reducing the time searching for blood meals, or driving them away. Permethrin impregnated nets also may deter a proportion of mosquitoes from entering houses. Irritant effect of nets treated with 200 mg and 500 mg permethrin/m² on susceptible and resistant genotypes of Anopheles stephensi was studied using the modified W.H.O. provisional technique. The W.H.O. irritability test was not used in the present study. Irritability test were carried out in a W.H.O. plastic bioassay cone. Three days old unfed, females were tested individually or in group of five mosquitoes. When female mosquitoes were confined in bioassay cones on treated netting, the resistant strain of A.stephensi showed significantly less irritability (Scored on the time until first flight take-off) in response to each dose as compared with the susceptible strain and F1 hybrids. The higher dose provoked more irritation of each genotypes, this could cause lower knockdown and kill rates which this dose could produce with each genotype. From the results of this study it could be concluded that a dose of 200 mg/m² of permethrin impregnated into bednets is preferable to 500 mg/m² for malaria control.