Dissimilar joining of Al5083 to MgAZ31 was performed through friction stir welding (FSW) and Diffusion bonding (DB). A constant tool rotation rate of 400 rpm and travel speed of 50 mm/min was used for FSW. The peak temperature of this specimen was raised to maximum of 435° C at the advancing side of the FS weld. Thermal cycle of the FSW specimen showed a distinct plateau at about 430 ° C, lasting for about 8 s. At the travel speed of 50 mm/min, the distance corresponding to 8 s is about7mm, which is the pin diameter. The presence of the temperature plateau indicates that the temperature at eachthermocouple remained constant as the pin passed it. It further indicates that a eutectic reaction probably occurred, and kept the temperature constant as the pin passed by. The weld had anirregular shaped region in the weld center of DB weld and, having a different microstructure and hardness from the two base materials. The irregular shaped region in DB weld, contained a large volume of intermetallic compound Al12Mg17. The present study suggests that constitutional liquation and solid state Diffusion at the interface resulted in the intermetallic compound formation in the weld center.

Diffusion bonding is used for joining the powder metallurgy components together or to wrought parts. The key element of the joining process is based on the variation of dimensional changes between counterparts during sintering cycle. These dimensional changes may be optimized by proper chemical composition and/or density of the green compacts. It is also known that the strength of the bond is influenced by several factors such as the particle size of powder, fit size of the assembling, sintering atmosphere and lubrication method. This article presents the effect of the iron particle size of iron powder on the bond strength of sintered bonded P/M Fe-5%Cu to low carbon wrought steels. To study the quality of the bonding zone, shear strength, metallography and microhardness tests were performed. It is found that the maximum bond strength is obtained when the particle size ranges from 75 to 100μm.

Background: Prostate cancer is the third leading cause of death and is the most common cause of cancer in elderly men. Regarding to the low accuracy of screening methods such as prostate-specific antigen (PSA), Digital Rectal Examination (DRE) and trans rectal ultrasound (TRUS) in detection and localization of tumor, Magnetic Resonance Imaging (MRI) and Diffusion Weighted Imaging (DWI) attracted many attentions in the past years. DWI reveals micro-molecular Diffusion, which is the Brownian motion of the spins in biologic tissues. This technique can delineate pathologic lesions with high tissue contrast against generally suppressed background signal. In this paper, the value of DWI in detection of prostate cancer is studied.Methods: In this cross-sectional study, the studied population are suspicious patients to prostate cancer based on high Prostatic Specific Antigen level or abnormal Digital Rectal Examination who refered for prostate biopsy to radiology department of Hazrate- Rasoul Hospital during the year 2011. The results of DWI are compared to biopsy results for all patients.Results: Eighty five patients are selected. The DWI sensitivity in detecting of prostate cancer is 100%, specificity 97.1% and positive and negative predictive values are 89.5% and 100%, respectively. The results showed that if DWI reports the prostate cancer as negative, the result was highly reliable and if it reports as positive, although the report was not 100% reliable, but it still had high reliability, more than 90%.Conclusion: DWI had high accuracy in detecting prostate cancer for patients with cancer. Also the accuracy of this method for patients without prostate cancer was acceptable compared to the other common methods.

Background and Objective: The aim of this study was to measure the shear bond strength of composite resin to human dentin surface bonded with three different bonding systems.Subjects and Methods: The crown surface of 66 extracted human third molar teeth were abraded with trimer in a wet environment until the dentin surface was exposed, and they were polished with silicon carbide paper 400 and 600 grit. Then, all the smooth smear layer samples were randomly classified into three equal groups. We used bonding according to the instruction of the manufacturer (the first group Single bond, the second group BC Plus and third group Charm bond).Then, the composite resin was bonded to the tooth surface by plastic tube (diameter: 1.8 mm, height: 5mm).Finally, shear bond strength was determined by universal testing machine (LMT 100).Results: The variance analysis (ANOYA) P value=0.000 revealed the mean of shear bond strength is different between three groups. The mean shear bond far first, second and third groups are 15.25 MP, 6.84 MP, 8.59 MP, respectively. The multiple comparison with THKEY test showed that there is different significance between group one and the other two groups which did not differ significantly.Conclusion: All in all, we found out that greatest shear bond strength to dentin is the American Single bond, which is better than Korean product (BC Plus and charm bond).

Background: Multiple sclerosis (MS) is a chronic disease that begins most commonly in young adults and is characterized pathologically by multiple areas of central nervous system (CNS) white matter inflammation, demyelination, and glial scarring. The most valuable aid for diagnosis is magnetic resonance imaging (MRI). New type of MRI has been developed on the basis of molecular Diffusion which capable of detecting acute and active lesions. Early diagnosis and treatment is possible to stop or slowdown progression of disease. The aim of this study is to compare the findings of conventional and Diffusion- weighted (DW) MRI in detection cerebral lesions of MS.Methods: Thirty patients with clinically definite MS and 30 healthy volunteers were studied in a descriptive-prospective survey over a twelve-month period of time.Conventional and DW MRI were used in both groups. Total number, morphology, location and the mean size of the intra-cerebral plaques of MS were compared between group. The sensitivity and the specificity of both imaging methods in detecting these plaques were determined.Results: Thirty patients with MS with the mean age of 32.76±8.79 years and 30 healthy individuals with the mean age of 32.75±9.23 years were enrolled. Plaque within the brain was significantly higher by the conventional method (P<0.05). Ovoid lesions were greater in number in the conventional method group. More lesions were detected by the conventional method in the areas of periventricle, centrum semiovale and corpus callosum. Regarding the size of plaque, the minimum measurement was significantly lower in the conventional method group. The sensitivity of both methods was 100%. The specificity of conventional and DW MRI was 86.6% and 96.6%, respectively.Conclusion: In our study the sensitivity of both methods was the same but the specificity of DW MRI was higher. DW MRI may detect lesions which are not detectable by the routine methods.

Introduction The staging of endometrial carcinoma is now performed based on postoperative pathological assessments. If the staging of the cancer could be possible with a preoperative non-invasive method, based on the International Federation of Gynecology and Obstetrics system, a more appropriate treatment protocol can be recommended for patients. This study was performed aimed to evaluate the diagnostic value of dynamic magnetic resonance imaging with Diffusion-weighted imaging in the staging of endometrial carcinoma, based on the postoperative histopathological reference standard. Methods This prospective study was conducted in 2016-2021 on 35 patients with endometrial cancer referred to Ghaem Hospital in Mashhad. The staging of endometrial cancer was performed based on MRI findings and pathological samples. The diagnostic value of MRI was calculated to distinguish stages 1 from 2 and 1A from 1B. The lesion dimensions in the MRI and the pathological samples were compared using independent-sample t-test and the lesion dimensions between different stages using the ANOVA test by SPSS (version 17). P<0. 05 was considered statistically significant. Results According to the findings of MRI and pathology, the majority of patients (93. 3%) were in stage 1, and 2 (6. 7%) were in stage 2. The sensitivity, specificity, positive and negative predictive value in differentiating stage 1 from stage 2 was 100%, and the sensitivity, specificity, positive and negative predictive value of MRI in differentiating IA from IB was 100%. Conclusion It seems that dMRI by DWI method can be used in the staging of endometrial tumors in the initial stages (stage 1 from 2 and IA from IB) with diagnostic value.

Background & Aim: This study was carried out to compare the microshear bond strength of Clearfil SE bond between the two different regions of primary tooth: incisal and cervical.Methods & Materials: In this experimental study which was controlled in vitro trial, 20 extracted primary canines without any caries, fracture and structural anomalies were disinfected and stored in normal saline of a room temperature. Every tooth was hemisectioned buccolingually via ground section. From the two resultant mesially and distally sections, one was chosen for the test, randomly. The composite resin material (Ap-x;A2) was placed and packed into the micro bore tygon tubing with the height of 1mm and internal diameter of 0.7 mm. After application of self - etching primer (according to the manufacturers' instructions) over the incisal and cervical (buccal aspect) dentin, tygon tubes containing composite, were placed over these areas and cured for 40". Microshear bond strength was determined using the microshear machine and also mode of failure was investigated by stereomicroscope in addition. From incisal and cervical regions of primary canines, two specimens were chosen randomly to investigate the dentinal tubules orientation in these regions by SEM.Results: SEM observations revealed that the dentinal tubules were oblique, both in incisal and cervical, so there was no difference in dentinal tubules orientation between these two regions. Mean microshear bond strength was 33.88±1:10.67 MPa for incisal and 28.79±11.72 Mpa for cervical region. Adhesive failure was the most predominant mode of failures being observed in both regions.Conclusion: There was no statistically significant difference in microshear bond strength of Clearfil SE bond between the incisal and cervical dentin in primary tooth.

Background and Aim: bonding systems have been traditionally used on normal dentin, even though caries-affected and sclerotic dentin is often the clinically relevant bonding substrates. A self-etching primer adhesive system (Clearfil SE bond) was evaluated for its ability to bond to caries-affected and normal dentin.Materials and Methods: In this experimental study, twelve extracted human primary molars with occlusal caries were selected. The enamel and superficial dentin were ground with a diamond disk and stained with a caries detector solution (propylen glycol and 1% acid red). The red-stained soft dentin which was classified as infected dentin was excavated and the affected dentin and surrounding normal dentin were polished with a 600 grit silicon carbide paper under running water to achieve a flat surface. The entire flat surface was bonded with Clearfil SE bond (Kuraray) according to the manufacturer's instructions and covered with composite resin Clearfil AP-X (Kuraray) to form a composite crown, approximately 4.5 mm high. The teeth were stored in distilled water at room temperature for 24 hours and were then sectioned with a diamond saw under running water in both X and Y directions, perpendicular to the bonded surface with dimensions of approximately 0.8-1 mm, so that the bonded areas of the affected or normal dentin were isolated. The obtained rods were divided into two groups: Affected and sound dentin. After measuring the cross-sectional areas at the interface, the specimens were mounted in a microtensile tester machine and pulled under tension to failure. The mode of failure was evaluated using a stereomicroscope and the data were analyzed by t-test.Results: Statistical analysis indicated that the microtensile bond strength in affected dentin (21.53±6.52MPa) was significantly lower (p<0.05) than normal dentin (26.98±7.31MPa).Conclusion: The studied self-etch system, attained lower microtensile bond strength in affected dentin as compared to normal dentin.

Aim: The aim of this study was to compare the etching effect of porcelain with Hydrofluoric acid (HF) one shear bond strength using one coat bond and self cure composite.Methods & Materials: The study was conducted experimentally using observation as its technique. 40 porcelain cubes were prepared and assigned into 4 groups. Group I specimens were treated with 35% phosphoric acid.Subsequently one coat bond was applied to bond the bracket, group II specimens were made fresh with fine diamond bur, treated with a 35% phosphoric acid and one coat bond was applied to bond the bracket, group III specimens were treated with a 20% hydroflouric acid (HF) and Nomix composite bond was applied to bond the bracket, group IV specimens were treated with a 40% HF acid and the same procedure in the group III was followed. The Instron machine was used at a crosshead speed of 0.5 mm/min to test the shear bond strength.Result: The shear strength was 2.47±1.8Mpa for group I, 5.64±2.6Mpa for group II, 3.28±1.8Mpa for group III and 3.03±2.6 for group IV. The overall difference between the four groups was statistically significant (P<0.05). Conclusion: The use of fine diamond bur and 35% phosphoric acid for Etching and use of one coat bond can achieve a successful bond between either use only phosphoric acid or 20% HF acid-Etched with No mix composite and 40% HF acid etched with No mix composite.