Unique Criteria Research Articles

Decision making criteria for adaptive reuse strategy in UNESCO world heritage city

PurposeWithin the next 20–30 years, adaptive reuse will have the greatest potential to reduce the built environment's environmental impact. Despite this, stakeholders still do not have sufficient points of reference in justifying and evaluating their adaptation practice decisions. The decision to reuse a building involves a complex set of considerations, including economic, social, environmental, legislative and architectural issues. The purpose of this paper is to investigate the unique decision-making criteria among stakeholders when considering adaptive reuse of an existing building asset in Malaysian heritage cities.Design/Methodology/ApproachThirty (30) unique criteria of decision-making were identified through a detailed literature review. The quantitative method of a self-completion questionnaire survey was conducted among stakeholders, including architects, valuers, planners, government department, developers and building owners. There were asked about their opinion and view on the criteria that could have influenced the decision-making in considering the adaptive reuse of the existing buildings in two heritage cities in the states of Penang and Malacca, Malaysia. Thus, it is the aim of this paper to evaluate and reveal the key criteria pertaining to this.FindingsThe analysis shows that there are seven key criteria that influence the decision-making of adaptive reuse of existing building: building value; building suitability; structural condition; official plan and zoning; building code; client requirement and heritage designated. In this regard, while “building value” factors were the key determinants in deciding whether to reuse or demolish, the asset’s suitability and structural condition, as well as rules, were also taken into account. Additionally, the environmental, economic and social tenets of sustainability were also identified as important, but were given less weight in matters concerning reuse. And due to the fact that many of the existing buildings are rapidly becoming obsolete, they are now increasingly being prioritized during the adaptive reuse decision-making process to ensure long-term outcomes.Research Limitations/ImplicationsThe research is limited owing to the difficulty in obtaining accurate information concerning the number of decision agents who have been involved in the adaptive reuse of existing buildings. Thus, the respondents in this research were randomly selected. Due to this limitation, the result does not encompass the whole Malaysia, only the stakeholders in Penang and Malacca have been selected the respondents in this study as these states are listed in the UNESCO World Heritage.Social ImplicationsWhen deciding whether to reuse or demolish an existing building, the proposed criteria will outline the crucial areas that must be examined by owners, developers and key project stakeholders. It can also be used to assess the financial, physical and social aspects of a cultural project.Originality/ValueThis paper adds to the body of knowledge concerning decision-making criteria for adaptive reuse strategies in achieving heritage city sustainability.

FRESH METHOD: 3D BIOPRINTING AS A NEW APPROACH FOR TISSUE AND ORGAN REGENERATION

Over the last decade, techniques of additive manufacturing of biomaterials have undergone a transformation, from a fast prototype tool used in research and development, to a viable approach in the production of customised medical devices. The key to this transformation is the ability of additive manufacturing to precisely define the structure and properties of a material in three dimensions, and to adjust those properties to unique anatomical and physiological criteria based on the medical data obtained by Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). The 3D bioprinting technique was developed as a solution to provide temporary and ubiquitous support of structures during the printing process. In general, integrated 3D printing may be understood as a building chamber that is filled with bearing materials, where biomaterials, cellular spheroids, cell-laden hydrogels and other materials (bioinks) are deposited using a syringe-based extruder. In particular, FRESH 3D bioprinting is a revolutionary technology, which may bring a fast and efficient advancement to medicine thanks to the ability to print new tissues from live cells.

Overview of Interventional Pulmonology for Radiologists.

Interventional pulmonology is a growing field specializing in minimally invasive procedures of the mediastinum, lungs, airways, and pleura. These procedures have both diagnostic and therapeutic indications and are performed for benign and malignant diseases. Endobronchial US has been combined with transbronchial needle aspiration to extend tissue sampling beyond the airways and into the lungs and mediastinum. Recent innovations extending the peripheral access of bronchoscopy include electromagnetic navigational bronchoscopy and thinner bronchoscopes. An important indication for therapeutic bronchoscopy is the relief of central airway obstruction, which may be severe and life threatening. Techniques for restoring patency of the central airways include mechanical debulking and multiple modalities for ablation, stent placement, and balloon bronchoplasty. Bronchoscopic lung volume reduction improves quality of life in certain patients with severe emphysema and is an important less invasive alternative to lung volume reduction surgery. Bronchial thermoplasty is likewise a nonpharmacologic treatment in patients with severe uncontrolled asthma. Many of these procedures have unique selection criteria that require precise evaluations at preprocedure imaging. Postprocedure imaging is also essential in determining outcome success and the presence of complications. Radiologists should be familiar with these procedures as well as the relevant imaging features in both planning and later surveillance. Evolving techniques that may become more widely available in the near future include robotic-assisted bronchoscopy, bronchoscopic transparenchymal nodule access, transbronchial cryobiopsy, ablation of early-stage cancers, and endobronchial intratumoral chemotherapy. An invited commentary by Wayne et al is available online. ©RSNA, 2021.

Postpartum psychosis: a diagnosis for the DSMV.

Postpartum psychosis (PPP) is a serious disorder that is associated with maternal and infant morbidity and mortality, yet it is denied a diagnostic classification in the Diagnostic and Statistical Manual of Mental Disorders (DSM). PPP was included in the DSMI (1952) and the DSMII (1968). It was removed from DSMIII (1980). The purpose of this article is to review the history of postpartum psychosis in the DSM and provide the mechanism and research that argues for the inclusion of postpartum psychosis as a separate diagnostic entity in the DSM. This work describes a proposal to the DSMV committee in 2020 for inclusion of PPP as a unique diagnosis based on the cognitive disorganization that accompanies psychotic symptoms. The proposal for inclusion provides the required criteria such as a rationale for the proposed change and evidence that PPP is distinct from other disorders. Validators are described. Reliability studies and benefits of inclusion are provided. We were unable to gain consensus on the presence of cognitive impairment for all postpartum psychotic episodes. The committee opined that we did not demonstrate proof that PPP is a distinct diagnosis. However, the committee acknowledged that the current "specifier" may be insufficient, and thus the option favored by the committee is that it could be added to Sect.3 of the DSM, "Conditions for Further Study." In the next proposal, we suggest that the unique temporal relationship of symptom onset to childbirth deserves consideration as unique criteria for diagnostic distinction of PPP.

An Overview of Indicator Choice and Normalization in Raw Material Supply Risk Assessments

Supply risk assessments are an integral part of raw material criticality assessments frequently used at the country or company level to identify raw materials of concern. However, the indicators used in supply risk assessments to estimate the likelihood of supply disruptions vary substantially. Here, we summarize and evaluate the use of supply risk indicators and their normalization to supply risk scores in 88 methods published until 2020. In total, we find 618 individual applications of supply risk criteria with 98 unique criteria belonging to one of ten indicator categories. The most often used categories of supply risk indicators are concentration, scarcity, and political instability. The most frequently used criteria are the country concentration of production, depletion time of reserves, and geopolitical risk. Indicator measurements and normalizations vary substantially between different methods for the same criterion. Our results can be used for future raw material criticality assessments to screen for suitable supply risk indicators and generally accepted indicator normalizations. We also find a further need for stronger empirical evidence of widely used indicators.

A biomarker for amniotic fluid embolism: the search continues.

Research into the pregnancy associated cytokine storm-like condition historically known as amniotic fluid embolism (AFE) has been hampered by a lack of unique diagnostic criteria. In its classic form, the clinical presentation of this condition is unmistakable. In less classic presentations, each of the clinical hallmarks of AFE (depressed ventricular function, lung injury and coagulopathy) may, in isolation, be seen in other obstetric conditions. Indeed, much of the confusion arising from previously published case series purporting to describe women with AFE appears to be the result of the inclusion of patients with other conditions. (Clark SL et al Obstet Gynecol 2014:123: 337-48) Identification of a reliable, objective biomarker specific to AFE is badly needed.

Donor Characteristics and Recipient Outcomes After Heart Transplantation in Adult Congenital Heart Disease.

BackgroundPatients with adult congenital heart disease (ACHD) experience long waitlist times for heart transplantation (HTx) while a large proportion of donor hearts are refused. The goal of this study was to inform optimal donor selection for patients with ACHD listed for HTx by examining the impact of donor characteristics on post‐HTx outcomes.Methods and ResultsUsing the Scientific Registry of Transplant Recipients, we conducted a retrospective analysis of patients aged ≥18 years listed for HTx in the United States between 2000 and 2016. We compared waitlist times between patients with ACHD and patients with noncongenital heart disease and constructed multivariate hazard models to identify donor characteristics associated with increased waitlist time. We then compared post‐HTx survival between patients with ACHD and patients with noncongenital heart disease and constructed multivariate hazard models to identify donor characteristics associated with mortality. There were very few differences in donor characteristics between HTx recipients with ACHD and those with noncongenital heart disease. Status 1A–listed patients with ACHD experienced longer waitlist times compared with patients with noncongenital heart disease. Increased wait times were associated with some donor characteristics. Post‐HTx outcomes varied over time, with patients with ACHD having inferior early mortality (0 to 30 days), similar intermediate mortality (31 days to 4 years), and superior late mortality (>4 years). We identified no donor characteristics associated with mortality to justify the observed differences in donor selection or waitlist time.ConclusionsHTx candidates with ACHD wait longer for transplant but do not require unique donor selection criteria. HTx teams should consider liberalizing donor criteria and focusing only on evidence‐based selection to improve waitlist outcomes and reduce the recipient–donor disparity.

Potential Privilege of Maltodextrin-α-Tocopherol Nano-Micelles in Seizing Tacrolimus Renal Toxicity, Managing Rheumatoid Arthritis and Accelerating Bone Regeneration.

BackgroundTacrolimus (TAC) is a powerful immunosuppressive agent whose therapeutic applicability is confined owing to its systemic side effects.ObjectiveHerein, we harnessed a natural polymer based bioconjugate composed of maltodextrin and α-tocopherol (MD-α-TOC) to encapsulate TAC as an attempt to overcome its biological limitations while enhancing its therapeutic anti-rheumatic efficacy.MethodsThe designed TAC loaded maltodextrin-α-tocopherol nano-micelles (TAC@MD-α-TOC) were assessed for their physical properties, safety, toxicological behavior, their ability to combat arthritis and assist bone/cartilage formation.ResultsIn vitro cell viability assay revealed enhanced safety profile of optimized TAC@MD-α-TOC with 1.6- to 2-fold increase in Vero cells viability compared with free TAC. Subacute toxicity study demonstrated a diminished nephro- and hepato-toxicity accompanied with optimized TAC@MD-α-TOC. TAC@MD-α-TOC also showed significantly enhanced anti-arthritic activity compared with free TAC, as reflected by improved clinical scores and decreased IL-6 and TNF-α levels in serum and synovial fluids. Unique bone formation criteria were proved with TAC@MD-α-TOC by elevated serum and synovial fluid levels of osteocalcin and osteopontin mRNA and proteins expression. Chondrogenic differentiation abilities of TAC@MD-α-TOC were proved by increased serum and synovial fluid levels of SOX9 mRNA and protein expression.ConclusionOverall, our designed bioconjugate micelles offered an excellent approach for improved TAC safety profile with enhanced anti-arthritic activity and unique bone formation characteristics.

ВЫБОР СИСТЕМЫ УПРАВЛЕНИЯ ОБУЧЕНИЕМ НА ОСНОВЕ МАТРИЦЫ ПРИОРИТЕТОВ

The rapid transition to distance education caused by the COVID-19 pandemic has forced some higher education institutions to implement distance learning systems as soon as possible. The period, prior to the implementation, to select the appropriate software was in some cases limited in time. A partial consequence of his limitation was the lack of an integrated approach for selecting criteria and their subsequent use to assess the benefits of a particular system. Under such conditions the decisions should be made on an imperative base without considering the requirements of some user groups. Objective. The study aims to assess the effectiveness of choosing a learning management system using a matrix of criteria, which significance degree determined by only a key group. Besides, the article evaluates the effectiveness of applying general criteria to choose software in modern market of distance learning systems. Method. As an assessment method, the author uses a multi-criteria selection based on a matrix of criteria. Each of the criteria’s weight and significance are determined analytically based on a survey of university teachers. Results. The work results are expressed in specific data - ranking systems using the chosen method, as well as recommendations to select criteria taking into account their expert or analytical assessment. Conclusions. The conclusions drawn from the study indicate the inadequacy of applying criteria, which significance confirmed by a focus group involved in the software product operation and maintenance. The author marked the necessity to use unique selection criteria reflecting each educational institution capabilities and needs individually.

Milestones in thromboangiitis obliterans: a position paper of the VAS-European independent foundation in angiology/vascular medicine.

Even today thromboangiitis obliterans has disease features that remain misunderstood or underappreciated. The epidemiology, etiology and pathophysiology of the disease are still unclear. Biomarkers and disease activity markers are lacking, thus clinical assessment is difficult. We are still struggling to establish unique diagnostic, staging and treatment criteria. This is an academic-collaborative effort to describe the pathophysiology, the clinical manifestations, the diagnostic approach, and the challenges of management of patients with TAO. A systematic search for relevant studies dating from 1900 to the end of 2020 was performed on the PubMed, SCOPUS, and Science Direct databases. Given the intriguing nature of presentation of TAO, its management, to some extent is not only different in different regions of the world but also varies within the same region. Following this project, we discovered ambiguity, overlap and lack of clear-cut criteria for management of TAO. An international group of experts however came to one conclusion. They all agree that management of TAO needs a call for action for a renewed global look with multi-center studies, to update the geographical distribution of the disease and to establish a unique set of diagnostic criteria and a consensus-based guideline for best treatment based on current evidence.

Advanced Phases at Diagnosis of Childhood Chronic Myeloid Leukemia : The Experience of the International Registry for Chronic Myeloid Leukemia (CML) in Children and Adolescents (I-CML-Ped Study)

Introduction. Chronic myeloid leukemia (CML) is a very rare disease in children and adolescents. The international registry of CML in children and adolescents (I-CML-Ped Study) established in the year 2011 has proven very beneficial to better describe this disease in pediatric cohorts.Aims: To describe the characteristics and the outcome of the pediatric population with advanced phases of CML at initial diagnosis.Patients and Methods: Patients enrolled in the international registry for CML in children and adolescents (I-CML-Ped Study) were the subjects of the study .Disease phases were defined according to the ELN criteria. Characteristics and outcome were determined in children in accelerated (AP) and blastic phase (BP). No recommendations were given regarding the treatment of the patients. Overall survival (OS) was estimated from diagnosis by the Kaplan and Meier method.Results. 479 children and adolescents less than 18 years old with CML were enrolled in the I-CML-Ped study between January 2011 and April 2017. Among them, 37 patients (7.7%) presented at initial diagnosis with CML in advanced phase according to the ELN criteria: 20 children (13 boys and 7 girls, median age 12.6 years - range 3 to 18 years) and 17 children (11 boys and 6 girls, median age 11 years - range 5 to 17 years) were diagnosed in AP and in BP, respectively. Among the 17 patients diagnosed in BP, 12 (70%) had lymphoid and 2 myeloid phenotype (not specified: 2 patients with extramedullary disease as unique criteria of BP). According to the Sokal score for patients less than 45 years, 73% and 82% of the patients in AP and BP at diagnosis were high risk patients, respectively. For the 17 children in BP, treatment consisted of tyrosine kinase inhibitors (TKI) (n=3) or a combination of chemotherapy and TKI successively and/or simultaneously (n=14); 11 of them were transplanted (sibling donor: n=2; unrelated donor n=8; unknown: n=1) with a median time after diagnosis of 7 months (range, 4.5 to 10 months). For the 20 children in AP, treatment consisted of TKI (n=17) or a combination of chemotherapy and TKI successively and/or simultaneously (n=3); 6 of them were transplanted (sibling donor: n=5; unrelated donor n=1) with a median time after diagnosis of 8 months (range, 4 to 21.5 months). With a median time from diagnosis of 3.5 years (range 8 months to 13.5 years), 13 out of 17 patients in BP at initial diagnosis are alive in at least major molecular response (MMR) (11 patients) or without MMR (2 patients) including 5 patients who were not transplanted; death occurred in 3 transplanted patients (relapses: 2 patients; chronic graft versus host disease: 1 patient) and in one patient with progression of the disease. Nineteen out of 20 patients in AP at initial diagnosis are alive (one patient died after progression) in at least MMR (15 patients) or without MMR (2 patients) or unknown status (2 patients). The 5 years OS rates were 94% (95% confidence interval (CI): 66%-99%) and 74% (95% CI: 44%-89%) for patients diagnosed in AP or BP, respectively.Conclusion: The data indicates that the frequency of advanced phases at diagnosis of CML is similar in children and in adults but with a predominance of lymphoid phenotype in children in blastic phase compared to adult population. Hematopoietic stem cell transplantation remains a curative treatment of children in blastic phase at diagnosis.Acknowledgment: The I-CML Ped study is supported by an unrestricted grant from Novartis Pharmaceutical Company DisclosuresNo relevant conflicts of interest to declare.

Life satisfaction of veterans with post-traumatic stress disorder: The predictive role of cognitive flexibility and alexithymia

Veterans with post-traumatic stress disorder have low life satisfaction and this exacerbates their symptoms. Life satisfaction is the result of each person's cognitive assessment of life based on their own unique criteria and circumstances. Therefore, the present study was conducted to predict the life satisfaction of veterans with post-traumatic stress disorder based on cognitive flexibility and alexithymia. In this descriptive-correlational study, 120 veterans with post-traumatic stress disorder who were hospitalized and treated in Isar Psychiatric Hospital in Ardabil in 2019 were selected as the available sample and examined. Data collection tools were Diner et al.’s Life Satisfaction Questionnaire, Dennis and Vander wall Cognitive Flexibility Questionnaire, and Toronto Emotional Dysfunction Questionnaire. Data were analyzed using Pearson correlation test and multiple regression analysis using SPSS 23 statistical software. Life satisfaction of veterans with post-traumatic stress disorder had a positive and significant relationship with cognitive flexibility and a negative and significant relationship with Alexithymia (P<0.05). Also, cognitive flexibility and alexithymia of 68% of the variance scores predicted the level of life satisfaction of veterans with post-traumatic stress disorder (P<0.001). High cognitive flexibility and low alexithymia improve life satisfaction in veterans with post-traumatic stress disorder. Therefore, training veterans to empower them in these areas is recommended.

Minding the gap: academic outcomes from pre-college programs

ABSTRACT This paper analyzes the effects of assignment to a one-year college preparatory program on academic performance in college. We use a large dataset of United States Naval Academy students from the 1988 to 2018 graduating classes, of which a little over 22% received remediation. Exploiting the Academy's unique admissions criteria, we instrument for pre-college treatment using the number and quality of other applicants originating from the same Congressional district. We find that these pre-college programs promote significant but short-lived improvements in academic grades. They also can encourage students to choose STEM-oriented majors, and promote retention by lowering voluntary exits.

Developing successful assumed autonomy‐based initiatives: An attention‐based view

AbstractResearch SummaryAdopting the attention‐based view of the firm as our principal theoretical lens, we explore the mechanisms by which subsidiaries attract or avoid headquarters attention in developing successful assumed autonomy‐based initiatives. To this end, our study utilizes qualitative data from subsidiary and headquarters perspectives in a multiple case study design. Our study reveals that subsidiaries first engage in non‐disclosure of assumed autonomy‐based initiatives to avoid negative headquarters attention. We then highlight the way in which subsidiaries undertake initiative selling to attract positive headquarters attention; in particular, we identify the unique selling criteria of demonstrable financial success and corporate alignment. Finally, we reveal the importance of timing in balancing the competing dual requirements of non‐disclosure and initiative selling.Managerial SummaryOur paper aims to explore the mechanisms by which subsidiaries attract or avoid attention from headquarters, to ensure that their proactive, autonomous actions facilitate the attainment of an extended role within the MNE. We highlight three mechanisms as especially important here for subsidiary managers. First, we reveal that subsidiaries initially engage in “non‐disclosure” of these actions to avoid negative headquarters attention. Second, we discover that subsidiaries ultimately look to demonstrate the financial success and corporate alignment of their autonomous actions. Finally, we emphasize the importance of timing in balancing the requirements of non‐disclosure and the “selling” of the subsidiary's actions to headquarters.

Methodology of studying art: sociology, culturology, and art history

This article describes the capabilities of methodology of studying art in the three interrelated scientific fields &amp;ndash; sociology, culturology, and art history. Emphasis is placed on determination of the key criteria of comprehensive approach towards the analysis of art: each of the three scientific fields may have its own unique criteria for such analysis, but there also universal criteria that allow most fully assessing the essence and purpose of art, considering the general trends of its development in modern reality. The subject of this research is the methodology of comprehensive analysis of art using the instruments of sociology, culturology, and art history. The main conclusions are as follows: 1) disclosure of the content of the methodology of studying art; 2) determination of various criteria for comprehensive analysis of art within the framework of sociology, culturology, and art history; 3) demonstration of capabilities of using certain criteria in analyzing the essence of art and artworks; 4) focus on the social dimension of art, touching upon the heuristic value of the methods of applied sociological research; 5) characteristics of the capabilities of studying the symbolic nature of art in the context of culturology; 6) assessment of the development trends of the methodology of modern art history.

Relationships of Brassica Seed Physical Characteristics with Germination Performance and Plant Blindness

Brassica oleracea is an important crop species that at early growth stages may exhibit failure of the apical growing point, an abnormality called “blindness”. The occurrence of blindness is promoted by exposure to low temperatures during imbibition and germination, but the causes of sensitivity to such conditions are unknown. We combined three analytical seed technology instruments to explore seed physical properties that are highly correlated with quality parameters and might be used directly for grading or sorting seed lots into subpopulations varying in potential susceptibility to blindness. For image analysis, we used the VideometerLab instrument, which can scan 19 wavelengths from ultraviolet to infrared and utilize that information in any combination to potentially identify unique criteria related to seed quality. The iXeed CF Analyzer was utilized to obtain chlorophyll fluorescence values for individual seeds. Chlorophyll contents of many seeds can be used as an indicator of seed maturity, a major contributor to seed quality. Finally, oxygen consumption measurements of individual seeds as obtained with the Q2 instrument are highly correlated with their performance under a wide variety of conditions. Six Brassica seed lots differed in their susceptibility to induction of blindness or loss of viability due to 48 h hydrated incubation at 1.5 ∘C. Analysis of physical and respiratory parameters identified some measurements that were highly correlated with the occurrence of blindness. Higher chlorophyll content, as detected by the CF-Mobile and certain wavelengths in the Videometer, was associated with greater occurrence of blindness or death following the induction treatment, suggesting that more immature seeds may be susceptible to blindness. Further research is required, but methods to detect and sort such seeds based on physical characteristics appear to be feasible.

A95 HOW ENDOSCOPY TEACHERS MAKE POLYPECTOMY ENTRUSTMENT DECISIONS IN CLINICAL AND SIMULATION-BASED SETTINGS

Abstract Background Entrustment, a central construct in competency-based medical education (CBME), represents the point at which clinical supervisors trust a trainee to perform a task independently. Many implementations of CBME involve assessing entrustment through observation of entrustable professional activities (EPAs). While EPAs are frequently assessed in both clinical and simulation-based settings, research has yet to clarify how faculty who teach endoscopy form judgments of entrustment across these two contexts. Aims We aimed to explore the features that endoscopy teachers report as influencing their entrustment decisions regarding polypectomy across clinical and simulation-based assessment settings. Methods We designed an interview-based, constructivist grounded theory-informed study involving endoscopy teachers and trainees in the University of Toronto gastroenterology residency program. Teachers completed separate EPA assessments of each trainee’s performance of an endoscopic polypectomy (colonic polyps &amp;lt; 1cm, Paris 0-Is or 0-Ip in morphology) in both settings. Teachers were interviewed after each assessment to explore how they made their entrustment decision within and across settings. Transcribed interview data were coded iteratively using constant comparison to generate themes. Results Based on 14 interviews with 7 endoscopy teachers, we found that they: (1) held multiple meanings of entrustment for polypectomy, both within and across participants, (2) expressed variability in how they justified their entrustment decisions, the related narrative, and numerical scoring, (3) held unique personal criteria for making decisions ‘comfortably,’ including authenticity of the task, variability in terms of polyp shape, location, and morphology, as well as the ability to assess trainee response to procedural complications (e.g., post-polypectomy bleeding), and (4) perceived a relative freedom when using simulation to make entrustment decisions due to the absence of a real patient. Conclusions We found that faculty who teach endoscopy defined polypectomy entrustment in a variety of ways, leading to variability in how they judged entrustment within and across trainees and assessment settings. The observed idiosyncrasies suggest gastroenterology competence committees cannot assume equivalence of EPA data obtained from different settings. Furthermore, educators designing faculty development for CBME will need to attend to the criteria that endoscopy teachers report they need to comfortably make entrustment decisions. Funding Agencies Royal College of Physicians and Surgeons of Canada

Failure phenomena in metallic and metal-lined polymer composite pressure vessels for aerospace applications

Metallic and metal-lined polymer composite pressure vessels are extensively used in industries, including the aerospace industry. In the absence of unique failure criteria for the structural elements, phenomenological or empirical methodologies are used by researchers. This paper discusses comprehensive methodologies for predicting burst pressure of metallic and metal-lined polymer composite pressure vessels for aerospace applications. Metallic pressure vessels were analysed using Ansys software, considering the elastic-plastic nature of the materials. The progressive analysis was performed in metal-lined composite pressure vessels in an explicit mode using Ansys software. The problem of solution convergence is discussed in detail. The extent of degradation in static analysis is suggested after multiple analysis trials. In the unit pressure extrapolation technique, the stress components were evaluated using Ansys software and transformed into a local coordinate system, and hence, the failure pressure of the first-ply was identified by the maximum stress criterion. The analysis then continues with the degradation of the failed layers using Ansys software, and successive failures of layers were identified in steps. The results of burst pressure, evaluated through the present analyses, showed good agreement with the published test results. The procedures described in the paper would be of interest to the designers of pressure vessels.

Three-dimensional Printing in Orthopedic Surgery: Current Applications and Future Developments

Three-dimensional (3D) printing technology has revolutionized how the authors examine, diagnose, and treat various medical conditions across a wide range of specialties. Synonymous with additive manufacturing, 3D printing fuses materials together layer by layer in 2-dimensional cross-sections to build the finished 3D product. This technology has proven superior to other manufacturing methods in certain instances because of its flexibility in the design process to create personalized products on demand. Within the field of orthopedics, 3D printing’s popularity has been driven in part by its capacity to address difficult cases in which the design must meet unique anatomic or pathologic criteria. As its use has become more common, so have the ways in which the field has adapted 3D printing technology to improve patient care. This review outlines the basics of 3D printing technology and its current applications in orthopedics: anatomic models, noncustom implants, patient-specific instrumentation, and patient-specific implants. The authors then briefly summarize 3D bioprinting and how it could impact bone and cartilage restoration in the future. Editor’s Note: I solicited this paper and have classified it as a Symposium Article after seeing Dr. Peterson present the subject at Duke Orthopaedic Surgery Department Grand Rounds. I thought it was an excellent update to the information contained in the September 2016 TIO symposium “3D Modeling, Printing and Biofabrication in Orthopaedic Surgery,” guest edited by Kevin Tetsworth (vol 31 no 3).

Reviewing equity investors’ funding criteria: a comprehensive classification and research agenda

ABSTRACT Venture capitalists and angel investors usually apply a set of assessment criteria to evaluate the key elements of entrepreneurial projects. However, since each investor considers different criteria, previous researchers who analysed investors’ decision making, ended up analysing a variety of divergent aspects. In this paper, a systematic literature review on the assessment criteria applied by equity investors was carried out. The purpose of this study was to identify and classify all the criteria considered by previous researchers to determine whether some aspects were investigated more extensively than others and to understand the reasons for this type of approach. After screening the abstracts of 894 journal publications, 53 articles were selected for a detailed analysis. In total, 208 unique criteria were identified and were subsequently classified into 35 specific categories, 11 generic classes and 4 main domains of analysis. The high level of detail and granularity of this work is one of its added values and can provide a knowledge base for future researchers who intend to apply new methodologies for the analysis of investors’ decision-making. Starting from the results obtained so far, a new agenda for future research is suggested to encourage a more data-driven approach leveraging data science techniques.