Laser Powder Bed Fusion of NiTiHf High-Temperature Shape Memory Alloy: Effect of Process Parameters on the Thermomechanical Behavior

Laser powder bed fusion has been widely investigated for shape memory alloys, primarily NiTi alloys, with the goal of tailoring microstructures and producing complex geometries. However, processing high temperature shape memory alloys (HTSMAs) remains unknown. In our previous study, we showed that it is possible to manufacture NiTiHf HTSMA, as one of the most viable alloys in the aerospace industry, using SLM and investigated the effect of parameters on defect formation. The current study elucidates the effect of process parameters (PPs) on the functionality of this alloy. Shape memory properties and the microstructure of additively manufactured Ni-rich NiTiHf alloys were characterized across a wide range of PPs (laser power, scanning speed, and hatch spacing) and correlated with energy density. The optimum laser parameters for defect-free and functional samples were found to be in the range of approximately 60–100 J/mm3. Below an energy density of 60 J/mm3, porosity formation due to lack-of-fusion is the limiting factor. Samples fabricated with energy densities of 60–100 J/mm3 showed comparable thermomechanical behavior in comparison with the starting as-cast material, and samples fabricated with higher energy densities (\u3e 100 J/mm3) showed very high transformation temperatures but poor thermomechanical behavior. Poor properties for samples with higher energies were mainly attributed to the excessive Ni loss and resultant change in the chemical composition of the matrix, as well as the formation of cracks and porosities. Although energy density was found to be an important factor, the outcome of this study suggests that each of the PPs should be selected carefully. A maximum actuation strain of 1.67% at 400 MPa was obtained for the sample with power, scan speed, and hatch space of 100 W, 400 mm/s, and 140 µm, respectively, while 1.5% actuation strain was obtained for the starting as-cast ingot. These results can serve as a guideline for future studies on optimizing PPs for fabricating functional HTSMAs

The social context-mining of trust in physicians and policy recommendations for improvement and promotion

زمینه و هدف: فهم این وضعیت چالش‌انگیز مستلزم پژوهش‌های علمی است تا بتوان از نتایج آن برای سیاستگذاری اجتماعی، آموزشی و بهداشتی استفاده کرد. هدف پژوهش حاضر شناسایی مؤلفه‌های اعتماد بیمار به پزشک و فهم چگونگی بهبود «اعتماد» بیماران به پزشکان بود. مواد و روش‌‌ها: روش این پژوهش کیفی از نوع فراترکیب است. طراحی، اجرا و نتیجه‌گیری این پژوهش در بازه زمانی 1398 تا 1400 انجام شده‌ است. پایگاه‌های علمی داخلی و بین‌المللی Normagz، MagIran، SID، Scopus، Science Direct و پایگاه نشریات با دسترسی آزاد مراجع اصلی استخراج متون بود. منطبق با رویکرد هفت مرحله‌ای Sandelowski و Barroso (2007 م.) و با راهبرد جستجوی هدفمند، 110 مقاله انتخاب شدند. برای دستیابی به اطلاعات مورد نیاز در خصوص پرسش‌های مطالعه، از واژگان کلیدی اصلی از قبیل «اعتماد به پزشک»، «رابطه پزشک و بیمار»، «اعتماد بین بیمار و پزشک» و «Trust to Patient»، «Trust between Patient and Physician» و «Relationship between Patient and Physician» استفاده شد. به لحاظ معیار ورود و خروج، انتخاب مقالات بر اساس شباهت‌های روش‌شناختی و فراهم‌ساختن پوشش عمیق و جامع از ویژگی‌های مورد نظر و مؤثر بر نتایج بود. با قیاس عنوان، چکیده، روش و یافته‌های پژوهش مرحله به مرحله تعدادی مقاله از دایره مطالعاتی حذف شد و در نهایت 54 مقاله مبنای کدگذاری و تحلیل قرار گرفت. ملاحظات اخلاقی: در مراحل مختلف طراحی، گردآوری و تحلیل داده و یافته‌های پژوهش از اصول و موازین اخلاق در پژوهش از قبیل وفاداری به متن، ارجاع‌دهی به منابع و رعایت اصول نگارش علمی تبعیت شده ‌است. یافته‌ها: نتایج این پژوهش نشان داد که اعتماد بیمار به پزشک رابطه‌ای پیچیده، دوسویه و متأثر از مؤلفه‌های متنوعی است. طبق یافته‌های این پژوهش عوامل اعتمادساز رابطه بیمار و پزشک در سه سطح کلان (اجتماعی ـ فرهنگی)، سطح میانی (قانونی ـ اخلاقی)، سطح خرد (حرفه‌ای ـ تخصصی، فردی ـ روان‌شناختی) طبقه‌بندی شد. افزون برآن، زیرطبقات یا زیرمؤلفه‌های این پژوهش شامل «اعتماد اجتماعی، رضایت اجتماعی، آموزش فرهنگی، مدیریت و محیط درمان، حقوق قانونی، اصول اخلاقی، امکانات درمان و بهداشت، محرمانگی، اخلاق علمی، حقوق قانونی، اصول اخلاقی، تعهد شغلی محرمانگی، دانش بالینی ـ تخصصی، مهارت کلامی ـ ارتباطی، باورمندی، آگاهی و تجربه درمانی بیمار و متغیرهای دموگرافیک» هستند. نتیجه‌گیری: بر اساس یافته‌های این پژوهش، بهبود رابطه مبتنی بر اعتماد میان بیمار و پزشک مستلزم فراهم‌نمودن شرایط و زمینه‌های اجتماعی و حرفه‌ای متنوعی است که در این میان مدیریت درمان (افزایش برابری در فرصت‌های دسترسی و با کیفیت برای همه و ساخت و تجهیز فضای درمانی بیمارمحور)، یادگیری درمان (آموزش آگاهی‌بخش و تقویت مهارت‌های ادراکی و انسانی پزشکان و کادر درمان) و مدیریت محیط درمان (آموزش مهارت ارتباطی، همزبانی با بیماران و فاصله‌گرفتن از جایگاه اقتدارگرایانه برای کلیه کادر پزشکی و درمان بر اساس نوع ارتباط)، از ضروریات زیرساختی آن تلقی می‌شود.Background and Aim: Trust between patient and physician has been challenged by overt and covert factors such as eroding social capital and increasing the cost of medical services in the community. To understand such a challenging situation, scientific research needs to be done so that the results of which can be used for making social, education and health policies. This study aimed to identify the components of trust between patient and physician as well as understand how to strengthen "trust" in physicians. Materials and Methods: A meta-synthesis was used to evaluate systematically the results of previous research regarding trust in physicians. This study has been designed, implemented and concluded from 2019 to 2021. Domestic and international scientific databases such as Normags, MagIran, SID, Scopus, Science Direct and open-access databases were the main sources for extracting text110 articles were selected based on the seven-step approach of Sandelowski and Barroso (2007) and focused search strategy. Key terms of "trust in patient", "trust between patient and physician", "physician-patient relationship", "trust between patient and physician" was used to obtain information about questionnaires. The criteria for selecting articles were methodological similarities and comprehensive coverage of the desired features affecting the results. By comparing the title, abstract, method and findings of the research, some articles were excluded from the study and finally, 54 articles were used as final sources for coding and analyzing. Ethical Considerations: The research ethical principles such as fidelity to the text, reference to sources and observance of the principles of scientific writing have been adhered to by the researchers in different stages of the research design, data collection, analysis and conclusion. Findings: The results of this study showed that the patients trust in the physician is a complex, two-way relationship and is affected by a variety of components. Based on the results, the confidence-building factors of the patient-physician relationship were classified into three levels of macro (socio-cultural), meso (legal-moral) and micro (professional-specialized, individual-psychological). In addition, the sub-components of this study include social trust, social satisfaction, cultural education, management and treatment environment, legal rights, ethical principles, treatment and health facilities, scientific ethics, legal rights, ethical principles, job commitment, confidentiality, clinical-specialized knowledge, verbal-communication skills, credibility, patient knowledge and therapeutic experience and demographic variables. Conclusion: Based on the findings of this study, improving the trust-based relationship between the patient and physician requires the provision of various social conditions and circumstances, including treatment management (increasing equality in access to high-quality educational opportunities as well as building and equipping patient-centered treatment spaces), treatment learning (educating, informing and strengthening the perceptual and human skills of physicians and treatment staff) and treatment environment management (communication skills training, communicating with patients and distancing oneself from an authoritarian position for all medical staff and treatment based on the type of communication), considered as its infrastructural requirements.   Cite this article as: Safaei M, Farasatkhah M, Shamsi Gooshki E. The Social Context-Mining of Patients Trust in Physicians and Recommendations for Improvement and Promotion: A Meta-Synthesis Analysis. Faṣlnāmah-i akhlāq-i pizishkī, i.e., Quarterly Journal of Medical Ethics. 2021; 15(46): e29

Comparison of Oncologic Short Term Results of Laparoscopic Versus Open Surgery of Rectal Cancer

Background Today, with improvements in laparoscopy technique, surgery of rectal cancer is performed by laparoscopy. Objectives This study was performed to evaluate oncologic results of open versus laparoscopic surgery of rectal cancer in terms of resection margins, removal of lymph nodes and recurrence rate. Patients and Methods This descriptive-analytic study was performed on 88 patients with middle and lower rectal cancer in the two equivalent groups of laparoscopic and open surgery in Mashhad Ghaem and Omid hospitals during 2011 - 2013. Information including age, sex, number of removed and involved lymph nodes, proximal, distal, and radial margins, tumor stage and location, recurrence and disease-free survival collected in the questionnaire and analyzed using descriptive statistics and frequency distribution tables and t-test. Results Both groups of open and laparoscopic surgery had similar characteristics of age, sex, recurrence and disease-free survival, tumor margins and one-year mortality. The number of removed and involved lymph nodes was higher in the laparoscopic group (5.16 vs. 3.55, respectively, with P < 0.050, and 1.74 vs. 0.59 with P = 0.023), but the ratio of involved lymph nodes to the total number of removed lymph nodes was not different between the two groups (LNR) (P = 0.071). Tumor stage was higher in the laparoscopic group and most were in stages II and III (P < 0.001). Conclusions Laparoscopic surgery is an effective technique for safe margin and removing lymph nodes in rectal cancer

The association of VEGF rs833061 and rs2010963 polymorphisms with susceptibility to colorectal cancer in an Iranian population

Vascular endothelial growth factor (VEGF) is one of the most important regulators of angiogenesis. Several single nucleotide polymorphisms (SNPs) are associated with the VEGF overexpression and tumor progression in several cancers. This study aimed to determine the association of VEGF rs833061 and rs2010963 polymorphism and their haplotypes with susceptibility to colorectal cancer (CRC) in the Iranian population. A total of 284 colorectal cancer patients (37.3% women, 62.7% men) were enrolled in this study. Healthy controls without evidence of cancer history or family cancer predispositions were frequency-matched to the cases by sex and age (+/- 5 years). Genotyping was performed by the Sequenom mass ARRAY method and the genotype distribution and risk estimate were analyzed by SPSS software. The correlation between the genotypes and clinicopathological parameters (Dukes stage, phenotype, location, differentiation, and tumor size) among colorectal cancer patients were investigated. We found a significant relationship, between rs833061T/C genotype and their TG haplotype with the age of diagnosis < 60; (p = 0.012, p = 0.014) and rs2010963G/C genotype with female gender and TG haplotype with third and fourth tumor stage and tumor location (p = 0.04and p = 0.047). This study showed that rs833061T/C genotype and TG haplotype increase the susceptibility to colon cancer in the Iranian population. This susceptibility has a significant relationship with the age of diagnosis and different stages of the tumor

The effect of silver nanoparticles on learning and memory in rodents: "a systematic review"

Abstract Background Silver nanoparticles (AgNPs) are widely used in medicine owing to their antiseptic activity and inducing cell death. Despite AgNPs' importance in nano-engineering and medical benefits, animal studies have shown silver toxicity can damage multiple organs such as the lungs, liver, kidneys, intestines, and brain. Several investigations revealed the correlation between Ag administration by different methods with impaired cognitive and behavioral abilities. Therefore, this systematic review aimed to conclude on the existing evidence of impairments in learning and memory that were changed in rodents exposed to AgNPs. Methods Main searches were retrieved in Google Scholar, Scopus, Web of Science, and PubMed databases from 1979 to 2022. Eligibility Criteria were applied to select and extract 15 articles among 892. Results Learning and memory abilities of rats and mice in screened studies were evaluated with MWM, NORT, PAL, T-maze, Y-maze, contextual fear conditioning, Radial Arm Maze and Carousel Maze test. Data have shown various sizes from 10 to 100 nm could affect the results of tests among animals exposed to AgNPs compared with control animals. However, in some treatments, results achieved from tests have not demonstrated significant differences between control and treated groups. Conclusion Studies have revealed that treatment with Ag-NPs of different sizes can impair learning and memory skills in rats and mice

Atherogenic index of plasma: A valuable novel index to distinguish patients with unstable atherogenic plaques

Background: Plaque instability is a leading cause of morbidity and mortality in coronary artery disease (CAD) patients. Numerous efforts have been made to figure out and manage unstable plaques prior to major cardiovascular events incidence. The current study aims to assess the values of the atherogenic index of plasma (AIP) to detect unstable plaques. Materials and Methods: The current case-control study was conducted on 435 patients who underwent percutaneous coronary intervention due to chronic stable angina (stable plaques, n = 145) or acute coronary syndrome (unstable plaques, n = 290). The demographic, comorbidities, chronic medications, biochemical and hematological characteristics of the patients were entered into the study checklist. The baseline AIP was measured according to the formula of triglycerides/high-density lipoprotein logarithm. Binary logistic regression was applied to investigate the standalone association of AIP with plaque instability. Receiver operating curve (ROC) was depicted to determine a cut-off, specificity, and sensitivity of AIP in unstable plaques diagnosis. Results: AIP was an independent predictor for atherogenic plaque unstability in both crude (odds ratio [OR]: 3.677, 95% confidence interval [CI]: 1.521–8.890; P = 0.004) and full-adjusted models (OR: 15, 95% CI: 2.77–81.157; P = 0.002). According to ROC curve, at cut-point level of 0.62, AIP had sensitivity and specificity of 89.70% and 34% to detect unstable plaques, respectively (area under the curve: 0.648, 95% CI: 0.601–0.692, P < 0.001). Conclusion: According to this study, at the threshold of 0.62, AIP as an independent biomarker associated with plaque instability can be considered a screening tool for patients at increased risk for adverse events due to unstable atherosclerotic plaques

Laser Powder Bed Fusion of NiTiHf High-Temperature Shape Memory Alloy: Effect of Process Parameters on the Thermomechanical Behavior

Laser powder bed fusion has been widely investigated for shape memory alloys, primarily NiTi alloys, with the goal of tailoring microstructures and producing complex geometries. However, processing high temperature shape memory alloys (HTSMAs) remains unknown. In our previous study, we showed that it is possible to manufacture NiTiHf HTSMA, as one of the most viable alloys in the aerospace industry, using SLM and investigated the effect of parameters on defect formation. The current study elucidates the effect of process parameters (PPs) on the functionality of this alloy. Shape memory properties and the microstructure of additively manufactured Ni-rich NiTiHf alloys were characterized across a wide range of PPs (laser power, scanning speed, and hatch spacing) and correlated with energy density. The optimum laser parameters for defect-free and functional samples were found to be in the range of approximately 60&ndash;100 J/mm3. Below an energy density of 60 J/mm3, porosity formation due to lack-of-fusion is the limiting factor. Samples fabricated with energy densities of 60&ndash;100 J/mm3 showed comparable thermomechanical behavior in comparison with the starting as-cast material, and samples fabricated with higher energy densities (&gt;100 J/mm3) showed very high transformation temperatures but poor thermomechanical behavior. Poor properties for samples with higher energies were mainly attributed to the excessive Ni loss and resultant change in the chemical composition of the matrix, as well as the formation of cracks and porosities. Although energy density was found to be an important factor, the outcome of this study suggests that each of the PPs should be selected carefully. A maximum actuation strain of 1.67% at 400 MPa was obtained for the sample with power, scan speed, and hatch space of 100 W, 400 mm/s, and 140 &micro;m, respectively, while 1.5% actuation strain was obtained for the starting as-cast ingot. These results can serve as a guideline for future studies on optimizing PPs for fabricating functional HTSMAs