16 research outputs found

    The comparison of the effectiveness of contingency management and trans-theoretical model on the risk of sexual behaviors in cocaine users: A short report study

    Get PDF
    BACKGROUND: A transtheoretical model (TTM) can be considered as a cognitive and motivational view, a component which plays a significant role in addiction. Further, the theoretical basis of contingency management (CM) treatment is the origin of behaviorism and relies on operant conditioning. The present study is performed aiming to determine the effectiveness of TTM and CM on cocaine use and sexual risk behaviors in cocaine users. METHODS: In this randomized clinical trial with 6-month follow-up, which was performed from 15 December 2014 to 20 November 2015, 75 male cocaine users were selected based on a respondent-driven sampling (RDS) method and were randomly divided into three groups by block randomization. The experimental group received a 12-week CM protocol and TTM and the control group was placed on the waiting list. Pre-test, post-test (after 12 weeks of training), and follow-up (six months) were administered. Data analysis was carried out using repeated measures analysis of variance (ANOVA), Scheffe’s post hoc test, and chi-square test through SPSS software. RESULTS: The mean age of the CM group, TTM group, and control group was estimated 26.12, 25.31, and 23.91, respectively. The primary outcome showed that CM and TTM had a significant effect on decreasing the sexual thoughts, sexual hyperactivity, and high risk behaviors. This effectiveness was stable until six months (P = 0.008), however there was not a significant difference between the two treatments (P = 0.200). The secondary outcome showed that in the changing stages, TTM (F-72%) and CM (F-60%) had a significant effectiveness which maintained until the follow-up stage. CONCLUSION: The findings more enhance the hope to integrate the theoretical approaches into the clinical interventions

    The comparison of executive functions between active users of methamphetamine and those in abstinence phase

    Get PDF
    BACKGROUND: Addiction to stimuli causes malfunction and morphologic changes in the nervous system. Representation of these changes in exclusive functions is accompanied by contradictory findings. This study was conducted aiming to compare the executive functions of two groups of users and non-users of methamphetamine in Tehran, Iran.METHODS: This study was conducted in the form of a case–control study from October 2014 to March 2014. In this regard, 30 men who were active users of methamphetamine and 35 men who were in abstinence phase in Tehran were selected using respondent-driven sampling (RDS) method and assigned into two groups. The executive functions of the two groups were evaluated using the software version of the Wisconsin Card Sorting Test (WCST) and the data were analyzed using t-test and chi-square test using SPSS software.RESULTS: The exclusive function index in methamphetamine users significantly decreased in comparison with the control group. Also, the preservation errors in consumer group were greater than the control group (P < 0.050).CONCLUSION: The results of this study showed that exclusive functions in stimulant users were associated with significant damage. Considering the importance of executive functions as a mediating factor in the recurrence of consumption, it is desirable to decrease the function of this index in the treatment of dependence to methamphetamine to be on the center of clinical attention

    The comparison of the effectiveness of contingency management and trans-theoretical model on the risk of sexual behaviors in cocaine users: A short report study

    Get PDF
    BACKGROUND: A transtheoretical model (TTM) can be considered as a cognitive and motivational view, a component which plays a significant role in addiction. Further, the theoretical basis of contingency management (CM) treatment is the origin of behaviorism and relies on operant conditioning. The present study is performed aiming to determine the effectiveness of TTM and CM on cocaine use and sexual risk behaviors in cocaine users.METHODS: In this randomized clinical trial with 6-month follow-up, which was performed from 15 December 2014 to 20 November 2015, 75 male cocaine users were selected based on a respondent-driven sampling (RDS) method and were randomly divided into three groups by block randomization. The experimental group received a 12-week CM protocol and TTM and the control group was placed on the waiting list. Pre-test, post-test (after 12 weeks of training), and follow-up (six months) were administered. Data analysis was carried out using repeated measures analysis of variance (ANOVA), Scheffe’s post hoc test, and chi-square test through SPSS software.RESULTS: The mean age of the CM group, TTM group, and control group was estimated 26.12, 25.31, and 23.91, respectively. The primary outcome showed that CM and TTM had a significant effect on decreasing the sexual thoughts, sexual hyperactivity, and high risk behaviors. This effectiveness was stable until six months (P = 0.008), however there was not a significant difference between the two treatments (P = 0.200). The secondary outcome showed that in the changing stages, TTM (F-72%) and CM (F-60%) had a significant effectiveness which maintained until the follow-up stage.CONCLUSION: The findings more enhance the hope to integrate the theoretical approaches into the clinical interventions

    Comparison of Oral Health-Related Quality of Life, Patient Satisfaction, and Stress Level between Patients Undergone Fixed Orthodontic Treatment and Clear Aligner Therapy

    Get PDF
    Introduction: Few studies were conducted on the effectiveness of clear aligners. The present study aimed to compare the quality of life related to oral health, patient satisfaction, and the level of anxiety caused by treatment in patients treated with fixed orthodontics and clear aligners.Materials and Methods: This descriptive-analytical study was conducted on 100 patients undergoing fixed orthodontic treatment six months from the start of their treatment and 100 patients undergoing treatment with clear aligners six months from the start of their treatment. The Oral Health Impact Profile (OHIP-14) questionnaire was used to compare the effect of these two treatments on the quality of life related to the oral health of these patients. Additionally, Patient Satisfaction (PSQ-18) questionnaire was used to check patients’ satisfaction and State Trait Anxiety Inventory was used to assess patients’ anxiety status.Results: The patients included 78 (38. 8%) males and 122 (61.2%) females. The average quality of life related to oral health was 53.26 with a range of 19 to 69, the average patient satisfaction was 42. 46, with a range of 14 to 50, and the mean and standard deviation of anxiety caused by treatment was 72. 26 ± 13. 93 with a range of 37 to 99. The average anxiety caused by the treatment in the transparent aligners group was significantly higher than the fixed orthodontic group (P<0.001). The average quality of life related to oral health in the transparent aligners group questionnaire was significantly lower than the fixed orthodontic group (P<0.001).Conclusion: The findings of this study showed that the level of anxiety of clear aligners recipients is higher, and their quality of life is lower

    Comparison Between Effect of Letrozole Plus Misoprostol and Misoprostol Alone in Terminating Non-Viable First Trimester Pregnancies: A Single Blind Randomized Trial

    Get PDF
    Objective: To evaluate the effect of letrozole plus misoprostol to terminate non-viable pregnancies in first trimester compared with the use of misoprostol alone. Materials and methods: In a single-blind clinical trial, 128 women over 18 years old referred to Educational-Medical centers of Tabriz University of Medical Science (Tabriz, Iran), for abortion in first trimester of non-viable pregnancies, were randomly selected in two intervention and control groups using Rand list (version 1.2) software. To complete abortion both groups received 600 mcg of misoprostolorally. The intervention group received letrozole 10 mg daily for 3 days before receiving misoprostolorally. Complete abortion rate and the side effects of both groups were recorded. Results: Mean pregnancy age based on LMP in intervention group and control group were 7.74 ± 0.95 and 8.52 ± 1.29 weeks respectively. Complete abortion rate in the intervention group was 93.7%, and in control group was 68.7% which was significantly higher in intervention group (p = 0.001). Abdominal pain in the intervention group is also significantly lower than that of the control group (p = 0.013). Intervention group also had significantly lower duration of bleeding rather than control group (p = 0.006). Conclusion: Based on the findings of this study, letrozole pretreatment with misoprostol for first-trimester medical abortion can increase complete abortion rate significantly without increasing side effects compared to use of misoprostol alone

    Influence of successive thermal cycling on microstructure evolution of EBM-manufactured alloy 718 in track-by-track and layer-by-layer design

    No full text
    Successive thermal cycling (STC) during multi-track and multi-layer manufacturing of Alloy 718 using electron beam melting (EBM) process leads to a microstructure with a high degree of complexity. In the present study, a detailed microstructural study of EBM-manufactured Alloy 718 was conducted by producing samples in shapes from one single track and single wall to 3D samples with maximum 10 longitudinal tracks and 50 vertical layers. The relationship between STC, solidification microstructure, interdendritic segregation, phase precipitation (MC, ή-phase), and hardness was investigated. Cooling rates (liquid-to-solid and solid-to-solid state) was estimated by measuring primary dendrite arm spacing (PDAS) and showed an increased cooling rate at the bottom compared to the top of the multi-layer samples. Thus, microstructure gradient was identified along the build direction. Moreover, extensive formation of solidification micro-constituents including MC-type carbides, induced by micro-segregation, was observed in all the samples. The electron backscatter diffraction (EBSD) technique showed a high textured structure in 〈001〉 direction with a few grains misoriented at the surface of all samples. Finer microstructure and possibility of more γ″ phase precipitation at the bottom of the samples resulted in slightly higher (~11%) hardness values compared to top of the samples

    Effect of build location on microstructural characteristics and corrosion behavior of EB-PBF built Alloy 718

    No full text
    Electron beam-powder bed fusion (EB-PBF), a high-temperature additive manufacturing (AM) technique, shows great promise in the production of high-quality metallic parts in different applications such as the aerospace industry. To achieve a higher build efficiency, it is ideal to build multiple parts together with as low spacing as possible between the respective parts. In the EB-PBF technique, there are many unknown variations in microstructural characteristics and functional performance that could be induced as a result of the location of the parts on the build plate, gaps between the parts and part geometry, etc. In the present study, the variations in the microstructure and corrosion performance as a function of the parts location on the build plate in the EB-PBF process were investigated. The microstructural features were correlated with the thermal history of the samples built in different locations on the build plate, including exterior (the outermost), middle (between the outermost and innermost), and interior (the innermost) regions. The cubic coupons located in the exterior regions showed increased level (~ 20 %) of defects (mainly in the form of shrinkage pores) and lower level (~ 30-35 %) of Nb-rich phase fraction due to their higher cooling rates compared to the interior and middle samples. Electrochemical investigations showed that the location indirectly had a substantial influence on the corrosion behavior, verified by a significant increase in polarization resistance (Rp) from the exterior (2.1 ± 0.3 kΩ.cm2) to interior regions (39.2 ± 4.1 kΩ.cm2). © 2020, The Author(s)

    Subsurface grain refinement in electron beam-powder bed fusion of Alloy 718 : Surface texture and oxidation performance

    No full text
    Subsurface grains of Alloy 718 additively manufactured via electron beam-powder bed fusion technique were refined using shot peening to improve the surface texture and oxidation performance. Oxidation of the specimens was performed at 650 and 800 degrees C in ambient air. Due to plastic deformation upon shot peening, compressive residual stress and high microstrain were generated in the subsurface region within a depth of approximately 50 mu m. The shot-peened specimen exhibited lower surface roughness, finer subsurface grains, and higher hardness compared to the as-built specimen. Shot peening, coupled with hot isostatic pressing and heat treatment (HIP-HT), yielded superior oxidation performance with substantially low oxidation kinetics at 800 degrees C. The smooth surface, as well as dense and refined subsurface microstructure resulting from shot peening, facilitated the formation of a continuous, protective, and adherent Cr-rich oxide scale.Financial supports of the Knowledge Foundation for the SupREme project (Dnr 20180203) and Aforsk for the SCC-SUMAN project (18-296) are highly acknowledged. The authors would like to thank Mr. Jonas Olsson, Dr. Mahdi Eynian, and Prof. Joel Andersson for their valuable help and advice in processing and characterization of the specimens. The authors would like to thank Mr. Olle Widman from Curtiss-wright Surface Technologies for shot peening, Mr. Johannes Gardstam, and Mr. James Shipley from Quintus Technologies AB for HT-HIPing of the specimens. The authors are grateful to Venkataramanan Mohandass for the characterization of the specimens. Chalmers Materials Analysis Laboratory (CMAL) at the Chalmers University of Technology are appreciated for the help in the XRD/SEM analysis.</p

    A state-of-the-art review on fatigue performance of powder bed fusion-built alloy 718

    No full text
    Alloy 718 is a Ni-Fe-based superalloy, which has been successfully adapted to powder bed fusion (PBF) additive manufacturing because of the alloy's adaptability with such emerging technology in achieving enhanced mechanical properties. Despite a promising perspective for PBF-built Alloy 718 in different industries, a few factors, including microstructural non-uniformities, volumetric defects, undesired non-metallic inclusions, anisotropic behavior, residual stress, as well as surface and sub-surface irregularities, lead to premature fatigue life of the parts. However, the PBF technology has been quickly growing, and associate progress has resulted in substantial advances in quality, hence increased fatigue life of the parts. Therefore, a critical assessment of the efficacy of the PBF-built Alloy 718 parts can be highly enlightening. A fundamental understanding of the relationship between feedstock material, manufacturing process, process parameters, microstructure, properties, and fatigue life of PBF-built Alloy 718 is crucial for improving the characteristics of the current materials, designing new alloy systems, and enhancing the capability of the PBF techniques. The present paper aims to comprehensively review the fundamentals and recent advances in the PBF-built Alloy 718 parts with improved fatigue life, the influence of thermal and mechanical post-treatment, mechanisms of fatigue crack initiation and growth, thermo-mechanical fatigue, dwell-time fatigue, as well as fracture behavior in different loading conditions and environments considering anisotropic characteristics of the material. An unbiased review of the literature provides an understanding of the advanced and outstanding achievements in the field that assure further research. An evaluation of the status of the field, the gaps in the theoretical understanding, and the fundamental needs for the sustainable development of PBF-built Alloy 718 with enhanced fatigue life in specific applications are also provided

    Tailored grain morphology via a unique melting strategy in electron beam-powder bed fusion

    Get PDF
    This study presents a unique melting strategy in electron beam-powder bed fusion of Alloy 718 to tailor the grain morphology from the typical columnar to equiaxed morphology. For this transition, a specific combination of certain process parameters, including low scanning speeds (400-800 mm/s), wide line offsets (300-500 mu m) and a high number of line order (#10) was selected to control local solidification conditions in each melt pool during the process. In addition, secondary melting of each layer with a 90. rotation with respect to primary melting induced more vigorous motions within the melt pools and extensive changes in thermal gradient direction, facilitating grain morphology tailoring. Four different types of microstructures were classified according to the produced grain morphology depending on the overlap zone between two adjacent melt pools, i.e., fully-columnar (overlap above 40 %), fully-equiaxed (overlap below 15 %), mixed columnar-equiaxed grains, and hemispherical melt pools containing mixed columnar-equiaxed grains (overlap similar to 20-25 %). The typical texture was &lt;001&gt;; however, the texture was reduced significantly through the transition from the columnar to equiaxed grain morphology. Along with all four different microstructures, shrinkage defects and cracks were also identified which amount of them reduced by a reduction in areal energy input. The hardness was increased through the transition, which was linked to the growth of the.” precipitates and high grain boundary density in the fully-equiaxed grain morphology.Funding from the “European Regional Development Fund,” the “Simulation and Control of Material affecting Processes” (SiCoMap), and the “Sustainable Manufacturing Through Next-Generation Additive Process” (SUMAN-Next) projects, with funding from the KK foundation, are highly acknowledged</p
    corecore