bluuebunny/crossref_metadata_2025 huggingface dataset:
Is Machine Learning a Better Way to Identify COVID-19 Patients Who Might Benefit from Hydroxychloroquine Treatment?—The IDENTIFY Trial
Authors: Burdick Hoyt , Lam Carson , Mataraso Samson , Siefkas Anna , Braden Gregory , Dellinger R. Phillip , McCoy Andrea , Vincent Jean-Louis , Green-Saxena Abigail , Barnes Gina , Hoffman Jana , Calvert Jacob , Pellegrini Emily , Das Ritankar
Published: November 2020

Therapeutic agents for the novel coronavirus disease 2019 (COVID-19) have been proposed, but evidence supporting their use is limited. A machine learning algorithm was developed in order to identify a subpopulation of COVID-19 patients for whom hydroxychloroquine was associated with improved survival; this population might be relevant for study in a clinical trial. A pragmatic trial was conducted at six United States hospitals. We enrolled COVID-19 patients that were admitted between 10 March and 4 June 2020. Treatment was not randomized. The study endpoint was mortality; discharge was a competing event. Hazard ratios were obtained on the entire population, and on the subpopulation indicated by the algorithm as suitable for treatment. A total of 290 patients were enrolled. In the subpopulation that was identified by the algorithm, hydroxychloroquine was associated with a statistically significant (p = 0.011) increase in survival (adjusted hazard ratio 0.29, 95% confidence interval (CI) 0.11–0.75). Adjusted survival among the algorithm indicated patients was 82.6% in the treated arm and 51.2% in the arm not treated. No association between treatment and mortality was observed in the general population. A 31% increase in survival at the end of the study was observed in a population of COVID-19 patients that were identified by a machine learning algorithm as having a better outcome with hydroxychloroquine treatment. Precision medicine approaches may be useful in identifying a subpopulation of COVID-19 patients more likely to be proven to benefit from hydroxychloroquine treatment in a clinical trial.
Locating the Origin of Femoral Maltorsion Using 3D Volumetric Technology—The Hockey Stick Theory
Authors: Ferràs-Tarragó Joan , Sanchis-Alfonso Vicente , Ramírez-Fuentes Cristina , Roselló-Añón Alejandro , Baixauli-García Francisco
Published: November 2020

Background: The origin of femoral maltorsion is often unknown. However, defining the origin of the rotation of the femoral maltorsion can be useful for establishing the most suitable point to do an external derotational osteotomy. Previous studies have not considered the femoral diaphysis in their investigations of the origin of the deformity. The study of the whole morphology of the femur with 3D volumetric tools, including the femoral diaphysis can contribute to a better understanding of the behavior of femoral maltorsion. Methods: An atypical case of unilateral femoral anteversion was selected. Both femurs were used to obtain 3D bio-models. The mirror image of the asymptomatic side was obtained and overlapped with the symptomatic femur. The Hausdorff–Besicovitch method was used to evaluate the morphologic discrepancies (in mm) between the two femurs in three zones: (1) the femoral neck, (2) the proximal diaphysis, and (3) the distal diaphysis. The differences between the two femurs were analyzed and its correlation was statistically defined using a lineal regression model. Results: The deformity in the distal diaphysis increased from the supracondylar area until the apex of the antecurvatum angle (R2 = 0.91) and then decreased until the base of the femoral neck (R2 = (−0.83)), to finally increase significantly in the femoral neck area (R2 = 0.87). All of the correlations were statistically significant (p-value ˂ 0.001). Conclusion: The femoral maltorsion originates in the supracondylar area and its rotational axis is the longitudinal axis of the femoral diaphysis. Even though the deformity affects the femoral diaphysis, its clinical relevance is much higher in the femoral neck since the rotational axis passes through its base. Thus, the osteotomy can be conducted along all of the femoral diaphysis as long as it is done perpendicular to it.
Evaluation of Systemic Renin and Angiotensin II Levels in Normal Tension Glaucoma
Authors: Jeon Soo Ji , Hwang Hyung Bin , Lee Na Young
Published: November 2020

The purpose of this study was to investigate the function of the renin–angiotensin–aldosterone system (RAAS) in normal tension glaucoma (NTG) patients by measuring the level of renin and angiotensin II (AngII) in the plasma. Twenty-four patients with NTG and 38 control subjects were included in this study. Renin and AngII were measured in the blood samples of all subjects by enzyme-linked immunosorbent assay (ELISA). No significant differences were found in the complete blood count, fasting glucose, low-density lipoprotein (LDL), and high-sensitivity C-reactive protein (hs-CRP) levels between the control and NTG groups. The systemic concentration and variability of the renin concentration in the blood was significantly higher in the NTG group (p = 0.005 and 0.005, respectively). According to multivariate logistic regression analysis, the variability of the renin concentration was associated with NTG (p = 0.006). In conclusion, the systemic concentration and variability of renin levels were elevated in NTG patients. An altered renin concentration could represent a difference in RAAS function in NTG patients.
Cerebrospinal Fluid and Serum d-Serine Levels in Patients with Alzheimer’s Disease: A Systematic Review and Meta-Analysis
Authors: Chang Chun-Hung , Kuo Hsiao-Lun , Ma Wei-Fen , Tsai Hsin-Chi
Published: November 2020

Objective: Alzheimer’s disease (AD) is a complex and severe neurodegenerative disease and still lacks effective methods of diagnosis. Dysfunction of the N-methyl-D-aspartate receptor (NMDAR) has been found to be involved in synapse dysfunction and neurotoxicity of AD mechanisms. d-Serine, an NMDAR receptor coagonist, is reported as a potential new biomarker for AD. However, the results of serum and cerebrospinal fluid (CSF) d-serine levels are conflicting. We conducted a meta-analysis to investigate the serum and CSF d-serine levels in patients with AD. Methods: We searched PubMed, the Cochrane central register of controlled trials, and the Cochrane database of systematic reviews for trials that measured d-serine levels both in patients with AD and in controls. We included controlled trials that analyzed d-serine levels in human samples (e.g., serum and CSF). Studies were pooled using a random-effect model for comparisons between AD and control group. We used effect size (ES; expressed as d-serine levels) in each selected meta-analysis to calculate standardized mean difference (SMD). Positive values indicated increased d-serine levels in AD group. We presented results with 95% confidence intervals (CIs). The heterogeneity of the included trials was evaluated through visually inspecting funnel plots and using the I2 statistic. Moderators of effects were explored using metaregression. Results: Seven trials with more than 1186 participants were included in this meta-analysis. d-serine levels in patients with AD were significantly higher than those in controls (SMD = 0.679, 95% CI = 0.335 to 1.022, p < 0.001). Subgroup analyses showed that the AD group had significantly higher d-serine levels in serum and CSF compared with the control group (SMD = 0.566 (serum) and 1.008 (CSF); 95% CI = 0.183 to 0.948 (serum) and 0.168 to 1.849 (CSF)). Moreover, a metaregression revealed a significant negative association between ES and mean mini-mental state examination score in AD group (slope = −0.1203, p = 0.0004). Conclusions: Our results revealed higher d-serine levels in the serum and CSF of patients with AD relative to the controls. Further studies with a larger sample size and longer follow-up are recommended to clarify this association.
Evans’ Syndrome: From Diagnosis to Treatment
Authors: Audia Sylvain , Grienay Natacha , Mounier Morgane , Michel Marc , Bonnotte Bernard
Published: November 2020

Evans’ syndrome (ES) is defined as the concomitant or sequential association of warm auto-immune haemolytic anaemia (AIHA) with immune thrombocytopenia (ITP), and less frequently autoimmune neutropenia. ES is a rare situation that represents up to 7% of AIHA and around 2% of ITP. When AIHA and ITP occurred concomitantly, the diagnosis procedure must rule out differential diagnoses such as thrombotic microangiopathies, anaemia due to bleedings complicating ITP, vitamin deficiencies, myelodysplastic syndromes, paroxysmal nocturnal haemoglobinuria, or specific conditions like HELLP when occurring during pregnancy. As for isolated auto-immune cytopenia (AIC), the determination of the primary or secondary nature of ES is important. Indeed, the association of ES with other diseases such as haematological malignancies, systemic lupus erythematosus, infections, or primary immune deficiencies can interfere with its management or alter its prognosis. Due to the rarity of the disease, the treatment of ES is mostly extrapolated from what is recommended for isolated AIC and mostly relies on corticosteroids, rituximab, splenectomy, and supportive therapies. The place for thrombopoietin receptor agonists, erythropoietin, immunosuppressants, haematopoietic cell transplantation, and thromboprophylaxis is also discussed in this review. Despite continuous progress in the management of AIC and a gradual increase in ES survival, the mortality due to ES remains higher than the ones of isolated AIC, supporting the need for an improvement in ES management.
Increased Omega-3 Fatty Acid Intake is Inversely Associated with Sarcopenic Obesity in Women but not in Men, Based on the 2014–2018 Korean National Health and Nutrition Examination Survey
Authors: Yang Woojung , Lee Jae-woo , Kim Yonghwan , Lee Jong Hun , Kang Hee-Taik
Published: November 2020

(1) Background: Omega-3 fatty acids (ω3FAs) are known to improve protein anabolism, increase the sensitivity to anabolic stimuli, decrease lipogenesis, and stimulate lipid oxidation. We aim to investigate whether ω3FAs are associated with the prevalence of sarcopenic obesity (SO). (2) Methods: Data were obtained from the 2014–2018 Korean National Health and Nutrition Examination Survey. The ratio of daily ω3FA intake to energy intake (ω3FA ratio) was categorized into four quartile groups. (3) Results: The prevalence of SO from Q1 to Q4 was 8.9%, 11.3%, 11.0%, and 9.8% respectively, in men and 17.4%, 14.0%, 13.9%, and 10.1% respectively, in women. The ω3FA ratio in individuals with and without SO were 1.0% and 0.9% in men (p-value = 0.271) respectively, and 0.8% and 1.0% in women (p-value = 0.017), respectively. Compared with Q1, odds ratios (95% confidence intervals) of Q2, Q3, and Q4 of ω3FA ratios were 1.563 (0.802–3.047), 1.246 (0.611–2.542), and 0.924 (0.458–1.864) respectively, in men and 0.663 (0.379–1.160), 0.640 (0.372–1.102), and 0.246 (0.113–0.534) respectively, in women, after fully adjusting for confounding factors. (4) Conclusions: The ω3FA ratio was significantly higher in older females without SO than in older females with SO. The ω3FA ratio was associated with the prevalence of SO in elderly females.
Difficult Cases of Autoimmune Hemolytic Anemia: A Challenge for the Internal Medicine Specialist
Authors: Fattizzo Bruno , Giannotta Juri , Serpenti Fabio , Barcellini Wilma
Published: November 2020

Autoimmune hemolytic anemia (AIHA) is diagnosed in the presence of anemia, hemolysis, and direct antiglobulin test (DAT) positivity with monospecific antisera. Many confounders of anemia and hemolytic markers should be included in the initial workup (i.e., nutrients deficiencies, chronic liver or kidney diseases, infections, and cancers). Besides classical presentation, there are difficult cases that may challenge the treating physician. These include DAT negative AIHA, diagnosed after the exclusion of other causes of hemolysis, and supported by the response to steroids, and secondary cases (infections, drugs, lymphoproliferative disorders, immunodeficiencies, etc.) that should be suspected and investigated through careful anamnesis physical examination, and specific tests in selected cases. The latter include autoantibody screening in patients with signs/symptoms of systemic autoimmune diseases, immunoglobulins (Ig) levels in case of frequent infections or suspected immunodeficiency, and ultrasound/ computed tomography (CT) studies and bone marrow evaluation to exclude hematologic diseases. AIHA occurring in pregnancy is a specific situation, usually manageable with steroids and intravenous (iv) Ig, although refractory cases have been described. Finally, AIHA may complicate specific clinical settings, including intensive care unit (ICU) admission, reticulocytopenia, treatment with novel anti-cancer drugs, and transplant. These cases are often severe, more frequently DAT negative, and require multiple treatments in a short time.
Circulating Tumor DNA as a Prognostic Determinant in Small Cell Lung Cancer Patients Receiving Atezolizumab
Authors: Herbreteau Guillaume , Langlais Alexandra , Greillier Laurent , Audigier-Valette Clarisse , Uwer Lionel , Hureaux José , Moro-Sibilot Denis , Guisier Florian , Carmier Delphine , Madelaine Jeannick , Otto Josiane , Souquet Pierre-Jean , Gounant Valérie , Merle Patrick , Molinier Olivier , Renault Aldo , Rabeau Audrey , Morin Franck , Denis Marc G , Pujol Jean-Louis
Published: November 2020

Background: The IFCT-1603 trial evaluated atezolizumab in small cell lung cancer (SCLC). The purpose of the present study was to determine whether circulating tumor DNA (ctDNA), prospectively collected at treatment initiation, was associated with the prognosis of SCLC, and whether it identified patients who benefited from atezolizumab. Methods: 68 patients were included in this study: 46 patients were treated with atezolizumab and 22 with conventional chemotherapy. Circulating DNA was extracted from plasma and NGS (Next Generation Sequencing) looked for mutations in the TP53, RB1, NOTCH1, NOTCH2, and NOTCH3 genes. ctDNA was detectable when at least one somatic mutation was identified, and its relative abundance was quantified by the variant allele fraction (VAF) of the most represented mutation. Results: We found that 49/68 patients (70.6%) had detectable baseline ctDNA. The most frequently identified mutations were TP53 (32/49; 65.3%) and RB1 (25/49; 51.0%). Patients with detectable ctDNA had a significantly lower disease control rate at week 6 compared with patients with no detectable ctDNA, regardless of the nature of the treatment. Detection of ctDNA was associated with a poor OS prognosis. The detection of ctDNA at a relative abundance greater than the median value was significantly associated with poor overall survival (OS) and progression free survival (PFS). Interestingly, the benefit in overall survival (OS) associated with low ctDNA was more pronounced in patients treated with atezolizumab than in patients receiving chemotherapy. Among patients whose relative ctDNA abundance was below the median, those treated with atezolizumab tended to have higher OS than those in the chemotherapy arm. Conclusion: ctDNA is strongly associated with the prognosis of SCLC patients treated with second-line immunotherapy. Its analysis seems justified for future SCLC clinical trials.
A Hybrid BEM-CFD Virtual Blade Model to Predict Interactions between Tidal Stream Turbines under Wave Conditions
Authors: Lombardi Nicolo’ , Ordonez-Sanchez Stephanie , Zanforlin Stefania , Johnstone Cameron
Published: November 2020

Tidal turbine array optimization is crucial for the further development of the marine sector. It has already been observed that tidal turbines within an array can be heavily affected by excessive aerodynamic interference, thus leading to performance deterioration. Small-scale experimental tests aimed at understanding the physical mechanisms of interaction and identifying optimal distances between machines can be found in the literature. However, often, the relatively narrow channels of laboratories imply high blockage ratios, which could affect the results, making them unreliable if extrapolated to full-scale cases. The main aim of this numerical study was to analyze the effects of the blockage caused by the laboratory channel walls in cases of current and also current surface waves. For this purpose, the performance predictions achieved for two turbines arranged in line for different lateral offsets in case of a typical laboratory scale were compared to the predictions obtained for a full scale, unconfined environment. The methodology consisted in the adoption a hybrid Blade Element Momentum–Computational Fluid Dynamics (BEM-CFD) approach, which was based on the Virtual Blade Model of ANSYS-Fluent. The results indicate that (1) the performance of a downstream turbine can increase up to 5% when this has a lateral separation of 1.5D from an upstream device in a full-scale environment compared to a misleading 15% calculated for the laboratory set-up, and (2) the relative fluctuations of power and thrust generated by waves are not significantly affected by the domain dimensions.
Space and Vine Cultivar Interact to Determine the Arbuscular Mycorrhizal Fungal Community Composition
Authors: López-García Álvaro , Jurado-Rivera José A. , Bota Josefina , Cifre Josep , Baraza Elena
Published: November 2020

The interest in the use of microbes as biofertilizers is increasing in recent years as the demands for sustainable cropping systems become more pressing. Although very widely used as biofertilizers, arbuscular mycorrhizal (AM) fungal associations with specific crops have received little attention and knowledge is limited, especially in the case of vineyards. In this study, the AM fungal community associated with soil and roots of a vineyard on Mallorca Island, Spain was characterized by DNA sequencing to resolve the relative importance of grape variety on their diversity and composition. Overall, soil contained a wider AM fungal diversity than plant roots, and this was found at both taxonomic and phylogenetic levels. The major effect on community composition was associated with sample type, either root or soil material, with a significant effect for the variety of the grape. This effect interacted with the spatial distribution of the plants. Such an interaction revealed a hierarchical effect of abiotic and biotic factors in shaping the composition of AM fungal communities. Our results have direct implications for the understanding of plant-fungal assemblages and the potential functional differences across plants in vineyard cropping.
Aetiology and 30-Year Long-Term Outcome of Children with Cardiomyopathy Necessitating Heart Transplantation
Authors: Zschirnt Martin , Thul Josef , Akintürk Hakan , Valeske Klaus , Schranz Dietmar , Skrzypek Susanne , Müller Matthias , Jux Christian , Hahn Andreas , Rupp Stefan
Published: November 2020

Studies assessing the long-term outcome after heart transplantation HTX in patients with cardiomyopathy (CM) in the paediatric age range are rare. The aim of this study was to determine the survival rate of children with CM undergoing HTX and to analyse how aetiology of cardiomyopathy influenced morbidity and mortality. We retrospectively analysed the medical records of children; who were transplanted in our centre between June 1988 and October 2019. 236 heart transplantations were performed since 1988 (9 re-transplants). 98 of 227 patients (43.2%) were transplanted because of CM. Survival rates were 93% after 1; 84% after 10 and 75% after 30 years. Overall; the aetiology of CM could be clearly identified in 37 subjects (37.7%). This rate increased up to 66.6% (12/19) by applying a comprehensive diagnostic workup since 2016. The survival rate was lower (p < 0.05) and neurocognitive deficits were more frequent (p = 0.001) in subjects with systemic diseases than in individuals with cardiac-specific conditions. These data indicate that the long-term survival rate of children with CM after HTX in experienced centers is high. A comprehensive diagnostic workup allows unraveling the basic defect in the majority of patients with CM undergoing HTX. Aetiology of CM affects morbidity and mortality in subjects necessitating HTX.
Establishment of a Molecular Tumor Board (MTB) and Uptake of Recommendations in a Community Setting
Authors: VanderWalde Ari , Grothey Axel , Vaena Daniel , Vidal Gregory , ElNaggar Adam , Bufalino Gabriella , Schwartzberg Lee
Published: November 2020

In the precision medicine era, molecular testing in advanced cancer is foundational to patient management. Molecular tumor boards (MTBs) can be effective in processing comprehensive genomic profiling (CGP) results and providing expert recommendations. We assessed an MTB and its role in a community setting. This retrospective analysis included patients with MTB recommendations at a community-based oncology practice January 2015 to December 2018; exclusions were death within 60 days of the MTB and/or no metastatic disease. Potentially actionable genomic alterations from CGP (immunohistochemistry, in-situ hybridization, next-generation sequencing) were reviewed bi-weekly by MTB practice experts, pathologists, genetic counselors, and other support staff, and clinical care recommendations were provided. Subsequent chart reviews determined implementation rates of recommendations. In 613 patients, the most common cancers were lung (23%), breast (19%), and colorectal (17%); others included ovarian, endometrial, bladder, and melanoma. Patients received 837 actionable recommendations: standard therapy (37%), clinical trial (31%), germline testing and genetic counseling (17%), off-label therapy (10%), subspecialty multidisciplinary tumor board review (2%), and advice for classifying tumor of unknown origin (2%). Of these recommendations, 36% to 78% were followed by the treating physician. For clinical trial recommendations (n = 262), 13% of patients enrolled in a clinical trial. The median time between CPG result availability and MTB presentation was 12 days. A community oncology-based comprehensive and high-throughput MTB provided useful clinical guidance in various treatment domains within an acceptable timeframe for patients with cancer in a large community setting.
Liquid Biomarkers for Pediatric Brain Tumors: Biological Features, Advantages and Perspectives
Authors: Madlener Sibylle , Gojo Johannes
Published: November 2020

Tumors of the central nervous system are the most frequent solid tumor type and the major cause for cancer-related mortality in children and adolescents. These tumors are biologically highly heterogeneous and comprise various different entities. Molecular diagnostics are already well-established for pediatric brain tumors and have facilitated a more accurate patient stratification. The availability of targeted, biomarker-driven therapies has increased the necessity of longitudinal monitoring of molecular alterations within tumors for precision medicine-guided therapy. Nevertheless, diagnosis is still primarily based on analyses of the primary tumor and follow-up is usually performed by imaging techniques which lack important information on tumor biology possibly changing the course of the disease. To overcome this shortage of longitudinal information, liquid biopsy has emerged as a promising diagnostic tool representing a less-invasive source of biomarkers for tumor monitoring and therapeutic decision making. Novel ultrasensitive methods for detection of allele variants, genetic alterations with low abundance, have been developed and are promising tools for establishing and integrating liquid biopsy techniques into clinical routine. Pediatric brain tumors harbor multiple molecular alterations with the potential to be used as liquid biomarkers. Consequently, studies have already investigated different types of biomarker in diverse entities of pediatric brain tumors. However, there are still certain pitfalls until liquid biomarkers can be unleashed and implemented into routine clinical care. Within this review, we summarize current knowledge on liquid biopsy markers and technologies in pediatric brain tumors, their advantages and drawbacks, as well as future potential biomarkers and perspectives with respect to clinical implementation in patient care.
Indigenous People on the Web
Authors: Dyson Laurel , Underwood Jim
Published: November 2020

This paper explores the ways in which Indigenous people around the world are participating in the World Wide Web, through establishing their own websites or accessing services via the Web. Indigenous websites are remarkably diverse: in addition to those representing Indigenous organizations and promoting Indigenous e-commerce, many websites have also been established to further unique concerns of Indigenous communities such as the maintenance and revitalization of Indigenous cultures, intercultural dialogue between Indigenous and non-Indigenous people, political advocacy and mobilization, community rebuilding and social support for disadvantaged communities. Despite the early involvement of Indigenous people on the Web, there still remain many unresolved issues, which include low levels of computer literacy and Internet connectivity, the cost of the technology, low levels of business understanding to support e-commerce, and concerns over the misappropriation of Indigenous knowledge and culture.
Learning to Collaborate and Collaborating to Learn: An Experiential Approach to Teaching Collaborative Systems
Authors: Kay Robert , Dyson Laurel
Published: November 2020

This paper describes the use of experiential learning theory in the development of an undergraduate subject in collaborative systems. The purpose of the subject was to introduce students to the design, development and use of collaborative systems in organizational environments. Early in the subject’s development it was decided that in order for students to gain a deeper understanding of the issues involved in the development of collaborative systems, they should collaborate using an e-learning system so that they could experience these problems first hand. The paper provides an overview of the subject structure, the views of students with regard to the learning approach and some of the outcomes that were observed. The findings revealed that the experiential approach was successful in providing students with a good understanding of the issues associated with the design and use of collaborative systems. However, while many achieved deeper learning outcomes than would normally be provided by a traditional didactic approach, there were students who failed to achieve the desired learning levels. The findings not only provide support for Perry’s model of intellectual development and the value of setting unstructured problems, but also demonstrate the need for structure in early experiential events to which students are exposed.
Experiment and Analysis for QoS of E-Commerce Systems
Authors: Kim Jeong-Su , Seo Sang-Koo
Published: November 2020

It is important for electronic commerce companies to understand the service quality of their systems, such as, the response time for users’ interactions, the service delay zone and the number of appropriate users accessing the systems concurrently. The accurate and prompt management of the service quality can greatly help build and operate systems more efficiently. In this paper we present a methodology for the service quality measurement and the user capacity modeling for electronic commerce systems. While most previous researches on this issue have been based on the closed-LAN environment, we conduct experiments under real network environment using sample e-Commerce systems. Specifically, we measure the response times for e-Commerce transactions under Cable, DSL, and wireless networks, and analyze the delay zones in processing the users’ service requests. The discrete event simulation and hybrid simulation are performed to estimate the maximum number of users using a response time limit as the service quality criterion. We also investigate the self-similar characteristics on the response time and the number of users, and the extensive results of the experiment and the simulations are described.
Motivations and Challenges for M-Business Transformation: A Multiple-Case Study
Authors: Tsai Heng-Sheng , Gururajan Raj
Published: November 2020

With the advance of wireless technology in recent years, issues of mobile (m-) business transformation become more important for researchers and practitioners. Subsequent to e-business transformation, mobile technology creates another opportunity of innovation inside and outside businesses. However, there is still limited information for m-business transformation. Hence, this study investigates the phenomenon by answering the questions: ‘Why do businesses transform into m-businesses?’ And ‘What are the possible challenges during the process of m-transformation?’ This study uses a multiple case study method, and reports the consolidated results of 17 interviews with 6 Australian organisations depicted as a framework, and aims at identifying the factors that influence the motivations for m-transformation, as well as the possible challenges during the process. The findings of this study can provide more understanding of the phenomenon, and further form the basis for a successful m-business transformation.
Key Drivers of Mobile Commerce Adoption. An Exploratory Study of Spanish Mobile Users
Authors: Bigné Enrique , Ruiz Carla , Sanz Silvia
Published: November 2020

Despite dramatic differences between non-store shoppers were discovered, very limited research has been conducted to examine them. This paper analyses the background of M-commerce and key drivers of future Mcommerce decision among Spanish mobile users. Our objective is two-fold: (1) to determine the influence of relations with the Mobile (frequency of Mobile use, length of Mobile use and Mobile affinity), demographics, non-store shopping previous experience (mail, catalogue, Television and Internet) and attitude to M-commerce and its influence on the M-commerce decision and (2) to identify key drivers of future M-commerce intention. We examined data from 606 personal interviews given to Spanish mobile users (270 Mobile shoppers and 336 non Mobile-shoppers) over 14 years old. Data analysis shows that age, attitude towards M-commerce, Internet shopping previous experience and relations with the Mobile (frequency, length of Mobile use and Mobile affinity) are the main predictors of M-commerce decision while age, length of Mobile use, Mobile affinity, consumer attitude towards M-commerce and previous M-commerce experience are the most relevant factors influencing future M-commerce intention. Based on these empirical results this research enables companies to know the key drivers influencing M-commerce adoption and, therefore, what aspects to highlight in their marketing strategies.
Business Model Scenarios for Remote Management
Authors: Braet Olivier , Ballon Pieter
Published: November 2020

This article critically appraises business model challenges in implementing remote management functionalities. Remote management is believed to create new service opportunities and foster convergence between previously dissociated islands of end user devices. Conflicting business logics from disparate industries, however, run counter to this attempt at centralization. We introduce a generic business modeling methodology that aims to move beyond traditional ICT investment appraisal techniques by combining four critical dimensions of design. We develop four business model scenarios based on the organizational design choice of ‘degree of vertical integration’ and the product design choices of ‘degree of product modularity’ and ‘distribution of intelligence’ and offer a description of the effect of these design choices on the intended customer value.
Phosphorus-Containing Silsesquioxane Derivatives as Additive or Reactive Components of Epoxy Resins
Authors: Szołyga Mariusz , Dutkiewicz Michał , Nowicki Marek , Sałasińska Kamila , Celiński Maciej , Marciniec Bogdan
Published: November 2020

Two phosphorus-containing cage-like silsesquioxane derivatives were synthesized as reactive or additive flame retardants for epoxy resin. The silsesquioxanes were obtained via an epoxide ring-opening reaction using a 10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPA). In one derivative containing in its structure 4 glycidoxypropyl and 4 phosphate groups, denoted as 4P4GS, only half of the epoxy rings was reacted with phosphate to obtain a reactive additive, while in the second derivative containing 8 phosphate groups, denoted as 8PS, all epoxy groups were converted, thus an additive modifier was obtained. The silsesquioxanes containing phosphorus atoms and the reactive phosphorus-free silsesquioxane derivative (octakis[(3-glycidoxypropyl)dimethylsiloxy]octasilsesquioxane (8GS)) were used to prepare hybrid materials based on epoxy resin. To compare the impact of the structure of silsesquioxane derivatives on the properties of hybrid materials, a number of samples containing 1, 5, and 10% of the modifiers making a series of epoxy materials containing additive or reactive modifiers, were obtained. The modified epoxies were studied using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), nanoindentation, water contact angle, and cone calorimetry tests to assess the effects of the modifier structure on the physicochemical properties of the investigated materials.
Numerical Prediction of Residual Stresses Distribution in Thin-Walled Press-Braked Stainless Steel Sections
Authors: Mutafi Ayad , Yidris Noorfaizal , Koloor Seyed Saeid Rahimian , Petrů Michal
Published: November 2020

Stainless steels are increasingly used in construction today, especially in harsh environments, in which steel corrosion commonly occurs. Cold-formed stainless steel structures are currently increasing in popularity because of its efficiency in load-bearing capacity and its appealing architectural appearance. Cold-rolling and press-braking are the cold-working processes used in the forming of stainless steel sections. Press braking can produce large cross-sections from thin to thick-walled sections compared to cold-rolling. Cold-forming in press-braked sections significantly affect member behaviour and joints; therefore, they have attained great attention from many researchers to initiate investigations on those effects. This paper examines the behaviour of residual stress distribution of stainless steel press-braked sections by implementing three-dimensional finite element (3D-FE) technique. The study proposed a full finite element procedure to predict the residual stresses starting from coiling-uncoiling to press-braking. This work considered material anisotropy to examine its effect on the residual stress distribution. The technique adopted was compared with different finite element techniques in the literature. This study also provided a parametric study for three corner radius-to-thickness ratios looking at the through-thickness residual stress distribution of four stainless steels (i.e., ferritic, austenitic, duplex, lean duplex) in which have their own chemical composition. In conclusion, the comparison showed that the adopted technique provides a detailed prediction of residual stress distribution. The influence of geometrical aspects is more pronounced than the material properties. Neglecting the material anisotropy shows higher shifting in the neutral axis. The parametric study showed that all stainless steel types have the same stress through-thickness distribution. Moreover, R/t ratios’ effect is insignificant in all transverse residual stress distributions, but a slight change to R/t ratios can affect the longitudinal residual stress distribution.
Arsenate Adsorption on Fly Ash, Chitosan and Their Composites and Its Relations with Surface, Charge and Pore Properties of the Sorbents
Authors: Adamczuk Agnieszka , Sofinska-Chmiel Weronika , Jozefaciuk Grzegorz
Published: November 2020

One of the ways to recycle millions of tons of fly ash and chitin wastes produced yearly is their utilization as low-cost sorbents, mainly for heavy metal cations and organic substances. To improve their sorption efficiency, fly ashes have been thermally activated or modified by chitosan. We aimed to deeply characterize the physicochemical properties of such sorbents to reveal the usefulness of modification procedures and their effect on As(V) adsorption. Using low temperature nitrogen adsorption, scanning electron microscopy, mercury intrusion porosimetry, potentiometric titration and adsorption isotherms of As(V) anions, surface, pore, charge and anion adsorption parameters of fly ash activated at various temperatures, chitosan, and fly ash modified by chitosan were determined. Arsenate adsorption equilibrium (Langmuir model), kinetics (pseudo-second order model) and thermodynamics on the obtained materials were studied. Neither temperature activation nor chitosan modifications of fly ash were necessary and profitable for improving physicochemical properties and As(V) adsorption efficiency of fly ash. Practically, the physicochemical parameters of the sorbents were not related to their anion adsorption parameters.
In Situ Laser-Induced Fabrication of a Ruthenium-Based Microelectrode for Non-Enzymatic Dopamine Sensing
Authors: Panov Maxim S. , Grishankina Anastasiia E. , Stupin Daniil D. , Lihachev Alexey I. , Mironov Vladimir N. , Strashkov Daniil M. , Khairullina Evgeniia M. , Tumkin Ilya I. , Ryazantsev Mikhail N.
Published: November 2020

In this paper, we propose a fast and simple approach for the fabrication of the electrocatalytically active ruthenium-containing microstructures using a laser-induced metal deposition technique. The results of scanning electron microscopy and electrical impedance spectroscopy (EIS) demonstrate that the fabricated ruthenium-based microelectrode had a highly developed surface composed of 10 μm pores and 10 nm zigzag cracks. The fabricated material exhibited excellent electrochemical properties toward non-enzymatic dopamine sensing, including high sensitivity (858.5 and 509.1 μA mM−1 cm−2), a low detection limit (0.13 and 0.15 μM), as well as good selectivity and stability.
Salecan-Clay Based Polymer Nanocomposites for Chemotherapeutic Drug Delivery Systems; Characterization and In Vitro Biocompatibility Studies
Authors: Florian Paula Ecaterina , Icriverzi Madalina , Ninciuleanu Claudia Mihaela , Alexandrescu Elvira , Trica Bogdan , Preda Silviu , Ianchis Raluca , Roseanu Anca
Published: November 2020

Salecan is a microbial polysaccharide suitable to obtain hydrogel for biomedical applications due to the excellent hydrophilicity and biocompatibility properties. In this work, Salecan of different concentrations was introduced into polymethacrylic acid (PMAA) in the presence of clay to form novel semi synthetic hydrogel nanocomposites systems and loaded afterwards with doxorubicin (DOX). The physical–chemical characteristics of the nanocomposites systems and their effect on the viability, and morphology of MDBK (Madin–Darby bovine kidney), HT-29 human colorectal adenocarcinoma and Colo 205 human colon adenocarcinoma cell lines were investigated. DOX release from the nanocomposite systems, cell up-take and subsequent effect on cell proliferation was also analyzed. It was found that Salecan concentration determined the swelling behavior, structural parameters and morphological features of the nanocomposite systems. The hydrogen bonds strongly influenced the formation of PMAA–Salecan–clay systems, each component bringing its own contribution, thus demonstrating the achievement of an advanced crosslinked network and a more compacted hydrogel nanocomposite morphology. All the synthesized nanocomposites had negligible toxicity to normal MDBK cells and chemoresistent HT-29 cell line, whereas in the case of Colo 205 cells a decrease by 40% of the cell viability was obtained for the sample containing the highest amount of Salecan. This effect was correlated with the lowest pore size distribution leading to highest available specific surface area and entrapped amount of DOX which was further released from the nanocomposite sample. Corroborating all the data it can be suggested that the synthesized nanocomposites with Salecan and clay could be good candidates as vehicles for chemotherapeutic agents.
Effects of Sodium Phosphate and Sodium Nitrite on the Pitting Corrosion Process of X70 Carbon Steel in Sodium Chloride Solution
Authors: Zhu Yongyan , Ding Jiayi , Zhang Jianli , Li Liang
Published: November 2020

In this paper, effects of sodium phosphate (Na3PO4) and sodium nitrite (NaNO2) on the pitting corrosion of X70 carbon steel in 0.10 mol/L NaCl solution were investigated by potentiodynamic polarization technique, electrochemical impedance spectroscopy (EIS) method, scanning electron microscope (SEM) and scanning electrochemical microscope (SECM). The SECM equipment was used to observe the dynamic processes of the pitting corrosion in situ. Na3PO4 or NaNO2 in the sodium chloride solution decreased the local anodic dissolution and increased the pitting resistance of the specimen. By analysis and comparison, it can be concluded that the inhibition effect of Na3PO4 is mainly due to the formation of a salt film, while the corrosion inhibition of NaNO2 is principally attributed to a protective oxide film on the electrode surface.
Effect of Asymmetric Accumulative Roll-Bonding process on the Microstructure and Strength Evolution of the AA1050/AZ31/AA1050 Multilayered Composite Materials
Authors: Mroz Sebastian , Wierzba Arkadiusz , Stefanik Andrzej , Szota Piotr
Published: November 2020

This paper aimed to propose the fabrication of light, Al/Mg/Al multilayered composite. Initially prepared three-layered feedstock was subjected to deformation during four rolling cycles (passes) using the conventional and modified accumulative roll bonding (ARB) processes at 400 °C, thanks to which 24-layered composite materials were produced. The modification of the ARB process was based on the application of the rotational speed asymmetry (asymmetric accumulative roll bonding, AARB). It was adopted that the initial thickness of the composite stack amounted to 3 mm (1 mm for each composite). The rolling was done in the laboratory duo D150 rolling mill with the application of the roll rotational speed asymmetry and symmetry av = 1.0 (ARB) and av = 1.25 and 1.5 (AARB). In this manuscript, it was proved that introducing the asymmetry into the ARB process for the tested Al/Mg/Al composite has an impact on the activation of additional shear bands, which results in higher fragmentation of the structure in comparison to the symmetrical process. Due to the application of the AARB, the reduction of the grain size by 17% was obtained, in comparison to the conventional ARB. Not to mention that at the same time there was an increase in strength of the fabricated multilayered composite.
Inverse Numerical Range and Determinantal Quartic Curves
Authors: Chien Mao-Ting , Nakazato Hiroshi
Published: November 2020

A hyperbolic ternary form, according to the Helton–Vinnikov theorem, admits a determinantal representation of a linear symmetric matrix pencil. A kernel vector function of the linear symmetric matrix pencil is a solution to the inverse numerical range problem of a matrix. We show that the kernel vector function associated to an irreducible hyperbolic elliptic curve is related to the elliptic group structure of the theta functions used in the Helton–Vinnikov theorem.
Short-Scale Stochastic Solar Energy Models: A Datacenter Use Case
Authors: Alouf Sara , Jean-Marie Alain
Published: November 2020

Modeling the amount of solar energy received by a photovoltaic panel is an essential part of green IT research. The specific motivation of this work is the management of the energy consumption of large datacenters. We propose a new stochastic model for the solar irradiance that features minute-scale variations and is therefore suitable for short-term control of performances. Departing from previous models, we use a weather-oriented classification of days obtained from past observations to parameterize the solar source. We demonstrate through extensive simulations, using real workloads, that our model outperforms the existing ones in predicting performance metrics related to energy storage.
Al-Based Metal Foams (AMF) as Permanent Cores in Casting: State-of-the-Art and Future Perspectives
Authors: Ubertalli Graziano , Ferraris Sara
Published: November 2020

Metal foams are extremely interesting due to their low density, high specific stiffness, and impact energy/vibration absorption ability. The use of metal foams as permanent cores in casting can be an opportunity to improve the properties of cast components and to simplify the technological processes (e.g., no need for core removal/treatment/recycling). The present review, besides a brief introduction on commercially available metal foams and their main characteristics, reports and compares the research works and patents related to the use of metal foams as permanent cores in casting, with particular attention to foam characteristics (e.g., presence/absence of surface skin, porosity and density, and liquid to foam volume ratio), casting parameters (e.g., pressure, the temperature of poured material, die material, and cooling rate), core–shell bonding and strategies for its improvement (foam surface treatments/coatings). The main issues that limit the application of metal foams as permanent cores in casting (e.g., poor core–shell bonding and poor foam resistance to casting conditions) are finally discussed together with possible solutions for their overcoming. Finally, characterization techniques, suitable for the investigation of foams, casting objects, and the core–shell bonding are summarized and compared in order to facilitate the selection and optimization of the more suitable ones.
A Workflow for Missing Values Imputation of Untargeted Metabolomics Data
Authors: Faquih Tariq , van Smeden Maarten , Luo Jiao , le Cessie Saskia , Kastenmüller Gabi , Krumsiek Jan , Noordam Raymond , van Heemst Diana , Rosendaal Frits R. , van Hylckama Vlieg Astrid , Willems van Dijk Ko , Mook-Kanamori Dennis O.
Published: November 2020

Metabolomics studies have seen a steady growth due to the development and implementation of affordable and high-quality metabolomics platforms. In large metabolite panels, measurement values are frequently missing and, if neglected or sub-optimally imputed, can cause biased study results. We provided a publicly available, user-friendly R script to streamline the imputation of missing endogenous, unannotated, and xenobiotic metabolites. We evaluated the multivariate imputation by chained equations (MICE) and k-nearest neighbors (kNN) analyses implemented in our script by simulations using measured metabolites data from the Netherlands Epidemiology of Obesity (NEO) study (n = 599). We simulated missing values in four unique metabolites from different pathways with different correlation structures in three sample sizes (599, 150, 50) with three missing percentages (15%, 30%, 60%), and using two missing mechanisms (completely at random and not at random). Based on the simulations, we found that for MICE, larger sample size was the primary factor decreasing bias and error. For kNN, the primary factor reducing bias and error was the metabolite correlation with its predictor metabolites. MICE provided consistently higher performance measures particularly for larger datasets (n > 50). In conclusion, we presented an imputation workflow in a publicly available R script to impute untargeted metabolomics data. Our simulations provided insight into the effects of sample size, percentage missing, and correlation structure on the accuracy of the two imputation methods.