bluuebunny/crossref_metadata_2025 huggingface dataset:
Patients’ Non-Medical and Organizational Needs during Cancer Diagnosis and Treatment
Authors: Osowiecka Karolina , Sroda Radoslaw , Saied Arian , Szwiec Marek , Mangold Sarah , Osuch Dominika , Nawrocki Sergiusz , Rucinska Monika
Published: August 2020

The aim of this cross-sectional study was to determine non-medical and organizational needs among cancer patients during diagnosis and treatment. The study included 384 cancer patients treated in five oncological centers in Poland. A questionnaire designed for the study was used. Most of the patients received psychological support from their partner/family/friends (88%), to a lesser extent from a psychologist (21%) and priests (4%). Forty-three percent of patients received social support from their partner/family/friends and only 7% of respondents received support from a social worker. Most patients stated they would like to have a professional who would help them with their non-medical problems during the diagnostic process and cancer treatment. The youth, with a higher education level who were professionally active and living in cities seemed to be more aware of their needs. Improvements to the oncological system in Poland should focus on expanding patient access to professional support of non-medical needs.
Geocoding Error, Spatial Uncertainty, and Implications for Exposure Assessment and Environmental Epidemiology
Authors: Kinnee Ellen J. , Tripathy Sheila , Schinasi Leah , Shmool Jessie L. C. , Sheffield Perry E. , Holguin Fernando , Clougherty Jane E.
Published: August 2020

Although environmental epidemiology studies often rely on geocoding procedures in the process of assigning spatial exposure estimates, geocoding methods are not commonly reported, nor are consequent errors in exposure assignment explored. Geocoding methods differ in accuracy, however, and, given the increasing refinement of available exposure models for air pollution and other exposures, geocoding error may account for an increasingly larger proportion of exposure misclassification. We used residential addresses from a reasonably large, dense dataset of asthma emergency department visits from all New York City hospitals (n = 21,183; 26.9 addresses/km2), and geocoded each using three methods (Address Point, Street Segment, Parcel Centroid). We compared missingness and spatial patterning therein, quantified distance and directional errors, and quantified impacts on pollution exposure estimates and assignment to Census areas for sociodemographic characterization. Parcel Centroids had the highest overall missingness rate (38.1%, Address Point = 9.6%, Street Segment = 6.1%), and spatial clustering in missingness was significant for all methods, though its spatial patterns differed. Street Segment geocodes had the largest mean distance error (µ = 29.2 (SD = 26.2) m; vs. µ = 15.9 (SD = 17.7) m for Parcel Centroids), and the strongest spatial patterns therein. We found substantial over- and under-estimation of pollution exposures, with greater error for higher pollutant concentrations, but minimal impact on Census area assignment. Finally, we developed surfaces of spatial patterns in errors in order to identify locations in the study area where exposures may be over-/under-estimated. Our observations provide insights towards refining geocoding methods for epidemiology, and suggest methods for quantifying and interpreting geocoding error with respect to exposure misclassification, towards understanding potential impacts on health effect estimates.
Sepsis-Associated Brain Dysfunction: A Review of Current Literature
Authors: Czempik Piotr F. , Pluta Michał P. , Krzych Łukasz J.
Published: August 2020

Sepsis-associated brain dysfunction (SABD) may be the most common type of encephalopathy in critically ill patients. SABD develops in up to 70% of septic patients and represents the most frequent organ insufficiency associated with sepsis. It presents with a plethora of acute neurological features and may have several serious long-term psychiatric consequences. SABD might cause various pathological changes in the brain through numerous mechanisms. Clinical neurological examination is the basic screening method for SABD, although it may be challenging in subjects receiving with opioids and sedative agents. As electrographic seizures and periodic discharges might be present in 20% of septic patients, screening with electroencephalography (EEG) might be useful. Several imaging techniques have been suggested for non-invasive assessment of structure and function of the brain in SABD patients; however, their usefulness is rather limited. Although several experimental therapies have been postulated, at the moment, no specific treatment exists. Clinicians should focus on preventive measures and optimal management of sepsis. This review discusses epidemiology, clinical presentation, pathology, pathophysiology, diagnosis, management, and prevention of SABD.
Introduction to Big Data Computing for Geospatial Applications
Authors: Li Zhenlong , Tang Wenwu , Huang Qunying , Shook Eric , Guan Qingfeng
Published: August 2020

The convergence of big data and geospatial computing has brought challenges and opportunities to GIScience with regards to geospatial data management, processing, analysis, modeling, and visualization. This special issue highlights recent advancements in integrating new computing approaches, spatial methods, and data management strategies to tackle geospatial big data challenges and meanwhile demonstrates the opportunities for using big data for geospatial applications. Crucial to the advancements highlighted here is the integration of computational thinking and spatial thinking and the transformation of abstract ideas and models to concrete data structures and algorithms. This editorial first introduces the background and motivation of this special issue followed by an overview of the ten included articles. Conclusion and future research directions are provided in the last section.
Philadelphia Chromosome-Positive Leukemia in the Lymphoid Lineage—Similarities and Differences with the Myeloid Lineage and Specific Vulnerabilities
Authors: Komorowski Lukasz , Fidyt Klaudyna , Patkowska Elżbieta , Firczuk Malgorzata
Published: August 2020

Philadelphia chromosome (Ph) results from a translocation between the breakpoint cluster region (BCR) gene on chromosome 9 and ABL proto-oncogene 1 (ABL1) gene on chromosome 22. The fusion gene, BCR-ABL1, is a constitutively active tyrosine kinase which promotes development of leukemia. Depending on the breakpoint site within the BCR gene, different isoforms of BCR-ABL1 exist, with p210 and p190 being the most prevalent. P210 isoform is the hallmark of chronic myeloid leukemia (CML), while p190 isoform is expressed in majority of Ph-positive B cell acute lymphoblastic leukemia (Ph+ B-ALL) cases. The crucial component of treatment protocols of CML and Ph+ B-ALL patients are tyrosine kinase inhibitors (TKIs), drugs which target both BCR-ABL1 isoforms. While TKIs therapy is successful in great majority of CML patients, Ph+ B-ALL often relapses as a drug-resistant disease. Recently, the high-throughput genomic and proteomic analyses revealed significant differences between CML and Ph+ B-ALL. In this review we summarize recent discoveries related to differential signaling pathways mediated by different BCR-ABL1 isoforms, lineage-specific genetic lesions, and metabolic reprogramming. In particular, we emphasize the features distinguishing Ph+ B-ALL from CML and focus on potential therapeutic approaches exploiting those characteristics, which could improve the treatment of Ph+ B-ALL.
Genome-Wide DNA Alterations in X-Irradiated Human Gingiva Fibroblasts
Authors: Nath Neetika , Hagenau Lisa , Weiss Stefan , Tzvetkova Ana , Jensen Lars R. , Kaderali Lars , Port Matthias , Scherthan Harry , Kuss Andreas W.
Published: August 2020

While ionizing radiation (IR) is a powerful tool in medical diagnostics, nuclear medicine, and radiology, it also is a serious threat to the integrity of genetic material. Mutagenic effects of IR to the human genome have long been the subject of research, yet still comparatively little is known about the genome-wide effects of IR exposure on the DNA-sequence level. In this study, we employed high throughput sequencing technologies to investigate IR-induced DNA alterations in human gingiva fibroblasts (HGF) that were acutely exposed to 0.5, 2, and 10 Gy of 240 kV X-radiation followed by repair times of 16 h or 7 days before whole-genome sequencing (WGS). Our analysis of the obtained WGS datasets revealed patterns of IR-induced variant (SNV and InDel) accumulation across the genome, within chromosomes as well as around the borders of topologically associating domains (TADs). Chromosome 19 consistently accumulated the highest SNVs and InDels events. Translocations showed variable patterns but with recurrent chromosomes of origin (e.g., Chr7 and Chr16). IR-induced InDels showed a relative increase in number relative to SNVs and a characteristic signature with respect to the frequency of triplet deletions in areas without repetitive or microhomology features. Overall experimental conditions and datasets the majority of SNVs per genome had no or little predicted functional impact with a maximum of 62, showing damaging potential. A dose-dependent effect of IR was surprisingly not apparent. We also observed a significant reduction in transition/transversion (Ti/Tv) ratios for IR-dependent SNVs, which could point to a contribution of the mismatch repair (MMR) system that strongly favors the repair of transitions over transversions, to the IR-induced DNA-damage response in human cells. Taken together, our results show the presence of distinguishable characteristic patterns of IR-induced DNA-alterations on a genome-wide level and implicate DNA-repair mechanisms in the formation of these signatures.
Alzheimer’s Disease and Specialized Pro-Resolving Lipid Mediators: Do MaR1, RvD1, and NPD1 Show Promise for Prevention and Treatment?
Authors: Miyazawa Keishi , Fukunaga Hisanori , Tatewaki Yasuko , Takano Yumi , Yamamoto Shuzo , Mutoh Tatsushi , Taki Yasuyuki
Published: August 2020

Alzheimer’s disease (AD) is a common neurodegenerative disease and a major contributor to progressive cognitive impairment in an aging society. As the pathophysiology of AD involves chronic neuroinflammation, the resolution of inflammation and the group of lipid mediators that actively regulate it—i.e., specialized pro-resolving lipid mediators (SPMs)—attracted attention in recent years as therapeutic targets. This review focuses on the following three specific SPMs and summarizes their relationships to AD, as they were shown to effectively address and reduce the risk of AD-related neuroinflammation: maresin 1 (MaR1), resolvin D1 (RvD1), and neuroprotectin D1 (NPD1). These three SPMs are metabolites of docosahexaenoic acid (DHA), which is contained in fish oils and is thus easily available to the public. They are expected to become incorporated into promising avenues for preventing and treating AD in the future.
Preventing Tumour Recurrence after Liver Transplantation: The Role of Machine Perfusion
Authors: Boteon Yuri , Flores Carvalho Mauricio Alfredo , Panconesi Rebecca , Muiesan Paolo , Schlegel Andrea
Published: August 2020

Tumour recurrence is currently a hot topic in liver transplantation. The basic mechanisms are increasingly discussed, and, for example, recurrence of hepatocellular carcinoma is often described in pre-injured donor livers, which frequently suffer from significant ischemia/reperfusion injury. This review article highlights the underlying mechanisms and describes the specific tissue milieu required to promote tumour recurrence after liver transplantation. We summarise the current literature in this field and show risk factors that contribute to a pro-tumour-recurrent environment. Finally, the potential role of new machine perfusion technology is discussed, including the most recent data, which demonstrate a protective effect of hypothermic oxygenated perfusion before liver transplantation.
Obesity and COVID-19: Molecular Mechanisms Linking Both Pandemics
Authors: Ritter Andreas , Kreis Nina-Naomi , Louwen Frank , Yuan Juping
Published: August 2020

The coronavirus disease 2019 COVID-19 pandemic is rapidly spreading worldwide and is becoming a major public health crisis. Increasing evidence demonstrates a strong correlation between obesity and the COVID-19 disease. We have summarized recent studies and addressed the impact of obesity on COVID-19 in terms of hospitalization, severity, mortality, and patient outcome. We discuss the potential molecular mechanisms whereby obesity contributes to the pathogenesis of COVID-19. In addition to obesity-related deregulated immune response, chronic inflammation, endothelium imbalance, metabolic dysfunction, and its associated comorbidities, dysfunctional mesenchymal stem cells/adipose-derived mesenchymal stem cells may also play crucial roles in fueling systemic inflammation contributing to the cytokine storm and promoting pulmonary fibrosis causing lung functional failure, characteristic of severe COVID-19. Moreover, obesity may also compromise motile cilia on airway epithelial cells and impair functioning of the mucociliary escalators, reducing the clearance of severe acute respiratory syndrome coronavirus (SARS-CoV-2). Obese diseased adipose tissues overexpress the receptors and proteases for the SARS-CoV-2 entry, implicating its possible roles as virus reservoir and accelerator reinforcing violent systemic inflammation and immune response. Finally, anti-inflammatory cytokines like anti-interleukin 6 and administration of mesenchymal stromal/stem cells may serve as potential immune modulatory therapies for supportively combating COVID-19. Obesity is conversely related to the development of COVID-19 through numerous molecular mechanisms and individuals with obesity belong to the COVID-19-susceptible population requiring more protective measures.
Effects of Ischemia-Reperfusion on Tubular Cell Membrane Transporters and Consequences in Kidney Transplantation
Authors: Faucher Quentin , Alarcan Hugo , Marquet Pierre , Barin-Le Guellec Chantal
Published: August 2020

Ischemia-reperfusion (IR)-induced acute kidney injury (IRI) is an inevitable event in kidney transplantation. It is a complex pathophysiological process associated with numerous structural and metabolic changes that have a profound influence on the early and the late function of the transplanted kidney. Proximal tubular cells are particularly sensitive to IRI. These cells are involved in renal and whole-body homeostasis, detoxification processes and drugs elimination by a transporter-dependent, transcellular transport system involving Solute Carriers (SLCs) and ATP Binding Cassettes (ABCs) transporters. Numerous studies conducted mainly in animal models suggested that IRI causes decreased expression and activity of some major tubular transporters. This could favor uremic toxins accumulation and renal metabolic alterations or impact the pharmacokinetic/toxicity of drugs used in transplantation. It is of particular importance to understand the underlying mechanisms and effects of IR on tubular transporters in order to improve the mechanistic understanding of IRI pathophysiology, identify biomarkers of graft function or promote the design and development of novel and effective therapies. Modulation of transporters’ activity could thus be a new therapeutic opportunity to attenuate kidney injury during IR.
Cutaneous Manifestations in Pancreatic Diseases—A Review
Authors: Miulescu Raluca , Balaban Daniel Vasile , Sandru Florica , Jinga Mariana
Published: August 2020

Pancreatic pathology, comprising acute and chronic pancreatitis, autoimmune pancreatitis and pancreatic neoplasms, primarily presents with gastrointestinal symptoms and signs; however, it is well recognized that it can also associate a wide range of extra-digestive features. Among these systemic manifestations, cutaneous involvement plays an important role both as a diagnostic clue for the pancreatic disease itself and serving as a prognostic factor for the severity of the condition. Recognition of these cutaneous signs is, however, far from being satisfactory, all the more as some of them are relatively rare. In the current review, we discuss skin involvement in pancreatic diseases, referring to pancreatic panniculitis, cutaneous hemorrhagic manifestations, skin metastasis, acanthosis nigricans, livedo reticularis, necrolytic migratory erythema and cutaneous fistula. We highlight the clinical characteristics, treatment and prognostic value of these lesions. Better awareness among medical specialties other than dermatology is needed for detection of the skin clues associated with pancreatic pathology.
Effectiveness of Different Application Parameters of Neuromuscular Electrical Stimulation for the Treatment of Dysphagia after a Stroke: A Systematic Review
Authors: Diéguez-Pérez Isabel , Leirós-Rodríguez Raquel
Published: August 2020

Background: Dysphagia causes severe complications among people with a stroke. Physiotherapy allows the cure of this pathology, and among the tools it offers is neuromuscular electrical stimulation. However, this is a technique that has not been protocolized. Therefore, it was considered necessary to carry out a systematic review on the efficacy of the various parameters of application of the neuromuscular electrical stimulation in dysphagia generated after a stroke. Methods: A systematic search for publications was conducted in March 2020 in the Pubmed, Cinahl, Medline, Web of Science and Scopus databases, using as search terms: Electric stimulation therapy, Deglutition disorders and Stroke. Results: 21 articles were obtained in which the application of neuromuscular electrical stimulation was applied in isolation (n = 7) or in combination with other techniques such as strengthening exercises and manual therapy techniques (n = 14), with this second modality of treatment having greater benefits for patients. Conclusion: The greatest efficacy of this technique is reached when applied at 60-80 Hz, 700 μs of pulse duration, at the motor intensity threshold and in sessions of 20–30 min.
Characterization of IgA Deposition in the Kidney of Patients with IgA Nephropathy and Minimal Change Disease
Authors: Cho Won-Hee , Park Seon-Hwa , Choi Seul-Ki , Jung Su Woong , Jeong Kyung Hwan , Kim Yang-Gyun , Moon Ju-Young , Lim Sung-Jig , Sung Ji-Youn , Jhee Jong Hyun , Chin Ho Jun , Choi Bum Soon , Lee Sang-Ho
Published: August 2020

Approximately 5% of patients with IgA nephropathy (IgAN) exhibit mild mesangial lesions with acute onset nephrotic syndrome and diffuse foot process effacement representative of minimal change disease (MCD). It is not clear whether these unusual cases of IgAN with MCD (IgAN-MCD) are variant types of IgAN or coincidental deposition of IgA in patients with MCD. In a retrospective multicenter cohort study of 18 hospitals in Korea, we analyzed 46 patients with IgAN-MCD. Patients with endocapillary proliferation, segmental sclerosis, and crescent were excluded, and the clinical features and prognosis of IgAN-MCD were compared with those of pure MCD. In addition, we performed galactose-deficient IgA1 (KM55) staining to characterize IgAN-MCD. Among the 21,697 patients with glomerulonephritis enrolled in the database, 46 patients (0.21%) were diagnosed with IgAN-MCD, and 1610 patients (7.4%) with pure MCD. The 46 patients with IgAN-MCD accounted for 0.6% of primary IgAN patients (n = 7584). There was no difference in prognosis between patients with IgAN-MCD and those with only MCD. IgA and KM55 showed double positivity in all patients with IgAN-MCD (n = 4) or primary IgAN (n = 5) under double immunofluorescent staining. However, in four patients with lupus nephritis, mesangial IgA was deposited, but galactose-deficient-IgA1 (Gd-IgA1) was not. These findings suggest that IgAN-MCD is a dual glomerulopathy in which MCD was superimposed on possibly indolent IgAN. We confirmed by KM55 staining that IgAN-MCD is true IgAN, enabling better characterizations of the disease. Furthermore, IgAN-MCD shows a good prognosis when treated according to the usual MCD treatment modality.
Sjögren’s Syndrome: The Clinical Spectrum of Male Patients
Authors: Chatzis Loukas , Pezoulas Vasileios C. , Ferro Francesco , Gandolfo Saviana , Donati Valentina , Binutti Marco , Callegher Sara Zandonella , Venetsanopoulou Aliki , Zampeli Evangelia , Mavrommati Maria , Argyropoulou Ourania D. , Michalopoulos Giorgos , Voulgari Paraskevi V. , Exarchos Themis , Baldini Chiara , Skopouli Fotini N. , Fotiadis Dimitrios I. , De Vita Salvatore , Moutsopoulos Haralampos M. , Tzioufas Athanasios G. , Goules Andreas V.
Published: August 2020

Background: To compare the clinical, serological and histologic features between male and female patients with Sjögren’s syndrome (SS) and explore the potential effect of gender on lymphoma development. Methods: From a multicenter population (Universities of Udine, Pisa and Athens, Harokopion and Ioannina (UPAHI)) consisting of consecutive SS patients fulfilling the 2016 ACR/EULAR criteria, male patients were identified, matched and compared with female controls. Data-driven multivariable logistic regression analysis was applied to identify independent lymphoma-associated factors. Results: From 1987 consecutive SS patients, 96 males and 192 matched female controls were identified and compared. Males had a higher frequency of lymphoma compared to females (18% vs. 5.2%, OR = 3.89, 95% CI: 1.66 to 8.67; p = 0.0014) and an increased prevalence of serum anti-La/SSB antibodies (50% vs. 34%, OR = 1.953, 95% CI: 1.19 to 3.25; p = 0.0128). No differences were observed in the frequencies of lymphoma predictors between the two genders. Data-driven multivariable logistic regression analysis revealed negative association of the female gender with lymphoma and positive association with lymphadenopathy. Conclusion: Male SS patients carry an increased risk of lymphoma development. Although statistics showed no difference in classical lymphoma predictors compared to females, data-driven analysis revealed gender and lymphadenopathy as independent lymphoma-associated features.
Nontraumatic Headache in Adult Emergency Patients: Prevalence, Etiologies, and Radiological Findings
Authors: Handschin Nadja , Oppliger Maria , Brehm Alex , Psychogios Marios , Bonati Leo , Nickel Christian H. , Bingisser Roland
Published: August 2020

The aim of this study was to measure prevalence, to describe underlying etiologies, and to assess radiological findings, focusing on significant intracranial abnormality (sICA). This was a prospective study of unselected adult patients admitted to the emergency department (ED) in a tertiary care hospital where all presenters were systematically interviewed about their symptoms. We attributed nontraumatic headache with neuroimaging to four groups: Normal or no new finding, extracranial abnormality, insignificant intracranial abnormality, or significant intracranial abnormality. sICA was defined as “needing acute therapy”, “needing follow-up neuroimaging”, or “clinically important neurological disorder”. Among 11,269 screened ED presentations, the prevalence of nontraumatic headache was 10.1% (1132 patients). Neuroimaging (cCT and/or cMRI) was performed in 303 patients. Seventy (23.1% of scanned; 6.2% of all headache patients) patients had sICA. Etiologies were cerebrovascular disease (56%), intracranial bleeding (17%), tumors (14%), infection (9%), and others (6%). Short-term outcome was excellent, with 99.3% in-hospital survival in patients with and 99.4% in patients without neuroimaging, and 97.1% in sICA; 1-year survival in outpatients with neuroimaging was 99.2%, 99.0% in outpatients without, and 88.6% in patients with sICA. Factors associated with sICA were age, emergency severity index (ESI) of 1 or 2, Glasgow coma score (GCS) under 14, focal neurological signs, and a history of malignancy. Prevalence of headache and incidence of sICA were high, but survival after work-up for nontraumatic headache was excellent in the 94% patients without sICA. Due to the incidence of sICA, extensive indication for neuroimaging in headache patients is further warranted, particularly in patients with risk factors.
Effects of Diesel Exhaust Particles on Mouse Gastric Stem Cells
Authors: Al-Sadik Heba , Sugathan Subi , Saseedharan Prashanth , Sulaiman Shahrazad , Beegam Sumaya , Nemmar Abderrahim , Attoub Samir , Karam Sherif M.
Published: August 2020

Stem cells have attracted many scientists because of their unique properties and therapeutic applications. However, very little is known on the environmental toxins that could affect their biological features. This study focuses on the consequences of the exposure of a cell line representative of the mouse gastric stem/progenitor (mGS) cells to diesel exhaust particles (DEPs). These immortal cells were cultured using routine protocols. The DEPs were added to the culture media at 1, 10, and 100 µg/mL for 1 to 72 h. The cells were assayed for their viability, migration, oxidative stress, and the expression of genes specific for cell proliferation, pluripotency, and death. DEPs induced a reduction in the metabolic activity of mGS cells, only at a high concentration of 100 µg/mL. However, no significant effects were detected on cell migration, oxidative stress markers (glutathione and thiobarbituric acid reactive substances), and cell death related proteins/genes. Interestingly, these findings were associated with down-regulation of Notch 2 and 3 and Bmi-1 proteins and activation of STAT3 involved in the regulation of the fate of stem cells. In conclusion, this study demonstrates that mGS cells have some resistance to oxidative stress and apoptosis when exposed to DEPs at the expense of their stemness.
Experimental and Numerical Impact Analysis of Automotive Bumper Brackets Made of 2D Triaxially Braided CFRP Composites
Authors: Böhm Robert , Hornig Andreas , Weber Tony , Grüber Bernd , Gude Maik
Published: August 2020

The impact behavior of carbon fiber epoxy bumper brackets reinforced with 2D biaxial and 2D triaxial braids was experimentally and numerically analyzed. For this purpose, a phenomenological damage model was modified and implemented as a user material in ABAQUS. It was hypothesized that all input parameters could be determined from a suitable high-speed test program. Therefore, novel impact test device was designed, developed and integrated into a drop tower. Drop tower tests with different impactor masses and impact velocities at different bumper bracket configurations were conducted to compare the numerically predicted deformation and damage behavior with experimental evidence. Good correlations between simulations and tests were found, both for the global structural deformation, including fracture, and local damage entities in the impact zone. It was proven that the developed phenomenological damage models can be fully applied for present-day industrial problems.
Study on the Thermodynamic Properties of Concrete Surface during Microwave Deicing of Airport Pavement
Authors: Chen Haowen , Xu Jinyu , Wu Yunquan , Liu Junliang , Huang He
Published: August 2020

In the cold belt area, the icing phenomenon often appears on the airport pavement, which affects the safety of aircraft take-off and landing. Microwave deicing technology can effectively solve this practical problem and has many advantages. Taking microwave deicing technology as the research object and the surface temperature of pavement concrete as the index, an open microwave test system has been established in this paper. Based on this system, the temperature distribution, variation rule, and influencing factors of concrete have been studied systematically. The results show that the surface temperature of concrete increases linearly due to microwave action. In addition, during the microwave action, the temperature increase of the concrete surface is centered on the center point and shows a stepwise decreasing trend along the radius. At the same time, the increase of microwave source height leads to the increase of surface temperature distribution uniformity. The surface ice affects the rate of temperature increase of concrete in stages under microwave action, and the surface edge area remains frozen for a certain period of time. The temperature distribution of concrete surface is a decisive factor affecting the degree of ice removal, and the concrete surface will generate residual heat after the microwave action ends. This phenomenon can delay the regression of the temperature distribution of the concrete surface, thus effectively preventing the re-freezing of the ice layer.
Synthesis and Characterization of GdVO4:Nd Near-Infrared Phosphors for Optical Time-Gated In Vivo Imaging
Authors: Nimmegeers Ben , Cosaert Ewoud , Carbonati Tecla , Meroni Daniela , Poelman Dirk
Published: August 2020

Many medical imaging techniques use some form of ionizing radiation. This radiation is not only potentially harmful for the patient, but also for the medical personnel. An alternative imaging technique uses near-infrared (NIR) emitting luminescent particles as tracers. If the luminescent probes are excited inside the body, autofluorescence from the biological tissues is also induced. This problem can be circumvented by using time-gated imaging. Hereby, the light collection only starts when the fluorescence of the tissue has decayed. This requires particles showing both excitation and emission in the near-infrared and a long decay time so that they can be used in time-gated imaging. In this work, Nd-doped GdVO4 NIR emitting particles were prepared using solid state reaction. Particles could be efficiently excited at 808 nm, right in the first transparency window for biological tissues, emitted in the second transparency window at around 1064 nm, and showed a decay time of the order of 70 μs, sufficiently long for time-gating. By using a Gd-containing host, these particles could be ideally suited for multimodal optical/magnetic imaging after size reduction and surface functionalization.
ASIC-Resistant Proof of Work Based on Power Analysis of Low-End Microcontrollers
Authors: Kim Hyunjun , Kim Kyungho , Kwon Hyeokdong , Seo Hwajeong
Published: August 2020

Application-Specific Integrated Circuit (ASIC)-resistant Proof-of-Work (PoW) is widely adopted in modern cryptocurrency. The operation of ASIC-resistant PoW on ASIC is designed to be inefficient due to its special features. In this paper, we firstly introduce a novel ASIC-resistant PoW for low-end microcontrollers. We utilized the measured power trace during the cryptographic function on certain input values. Afterward, the post-processing routine was performed on the power trace to remove the noise. The refined power trace is always constant information depending on input values. By performing the hash function with the power trace, the final output was obtained. This framework only works on microcontrollers and the power trace depends on certain input values, which is not predictable and computed by ASIC.
A New ECDLP-Based PoW Model
Authors: Meneghetti Alessio , Sala Massimiliano , Taufer Daniele
Published: August 2020

Blockchain technology has attracted a lot of research interest in the last few years. Originally, their consensus algorithm was Hashcash, which is an instance of the so-called Proof-of-Work. Nowadays, there are several competing consensus algorithms, not necessarily PoW. In this paper, we propose an alternative proof of work algorithm which is based on the solution of consecutive discrete logarithm problems over the point group of elliptic curves. At the same time, we sketch a blockchain scheme, whose consensus is reached via our algorithm. In the considered architecture, the curves are pseudorandomly determined by block creators, chosen to be cryptographically secure and changed every epoch. Given the current state of the chain and a prescribed set of transactions, the curve selection is fully rigid, therefore trust is needed neither in miners nor in the scheme proposers.
Financial Performance Assessment of Construction Firms by Means of RAM-Based Composite Indicators
Authors: Tsolas Ioannis E.
Published: August 2020

This paper aims to provide a novel construct that is based on data envelopment analysis (DEA) range adjusted measure (RAM) of efficiency and demonstrate its practical implementation by evaluating the financial performance of a sample of three upper-class contracting license (Classes 5–7) Greek construction firms. In a two-step framework, firm efficiency (i.e., composite indicators (CIs)) is produced firstly by means of RAM using single financial ratios, which are selected by grey relational analysis (GRA), and then Tobit regression is employed to model the CIs. In light of the results, only 4% of the sampled firms are efficient, and the firm ranking is consistent with the ranking of Grey Relational Grande (GRG) values produced by GRA. Moreover, the firms with a contracting license of the highest level (Class 7) appear not to be superior in efficiency to their counterparts that belong to Classes 5–6.
Strong, Strongly Universal and Weak Interval Eigenvectors in Max-Plus Algebra
Authors: Gavalec Martin , Plavka Ján , Ponce Daniela
Published: August 2020

The optimization problems, such as scheduling or project management, in which the objective function depends on the operations maximum and plus, can be naturally formulated and solved in max-plus algebra. A system of discrete events, e.g., activations of processors in parallel computing, or activations of some other cooperating machines, is described by a systems of max-plus linear equations. In particular, if the system is in a steady state, such as a synchronized computer network in data processing, then the state vector is an eigenvector of the system. In reality, the entries of matrices and vectors are considered as intervals. The properties and recognition algorithms for several types of interval eigenvectors are studied in this paper. For a given interval matrix and interval vector, a set of generators is defined. Then, the strong and the strongly universal eigenvectors are studied and described as max-plus linear combinations of generators. Moreover, a polynomial recognition algorithm is suggested and its correctness is proved. Similar results are presented for the weak eigenvectors. The results are illustrated by numerical examples. The results have a general character and can be applied in every max-plus algebra and every instance of the interval eigenproblem.
Determining When an Algebra Is an Evolution Algebra
Authors: Bustamante Miguel , Mellon Pauline , Velasco M.
Published: August 2020

Evolution algebras are non-associative algebras that describe non-Mendelian hereditary processes and have connections with many other areas. In this paper, we obtain necessary and sufficient conditions for a given algebra A to be an evolution algebra. We prove that the problem is equivalent to the so-called SDC problem, that is, the simultaneous diagonalisation via congruence of a given set of matrices. More precisely we show that an n-dimensional algebra A is an evolution algebra if and only if a certain set of n symmetric n×n matrices {M1,…,Mn} describing the product of A are SDC. We apply this characterisation to show that while certain classical genetic algebras (representing Mendelian and auto-tetraploid inheritance) are not themselves evolution algebras, arbitrarily small perturbations of these are evolution algebras. This is intringuing, as evolution algebras model asexual reproduction, unlike the classical ones.
The Approximation Property of a One-Dimensional, Time Independent Schrödinger Equation with a Hyperbolic Potential Well
Authors: Choi Ginkyu , Jung Soon-Mo
Published: August 2020

A type of Hyers–Ulam stability of the one-dimensional, time independent Schrödinger equation was recently investigated; the relevant system had a parabolic potential wall. As a continuation, we proved a type of Hyers–Ulam stability of the time independent Schrödinger equation under the action of a specific hyperbolic potential well. One of the advantages of this paper is that it proves a type of Hyers–Ulam stability of the Schrödinger equation under the condition that the potential function has singularities.
Synthesis and Characterization of 40 wt % Ce0.9Pr0.1O2–δ–60 wt % NdxSr1−xFe0.9Cu0.1O3−δ Dual-Phase Membranes for Efficient Oxygen Separation
Authors: Chen Guoxing , Zhao Zhijun , Widenmeyer Marc , Yan Ruijuan , Wang Ling , Feldhoff Armin , Weidenkaff Anke
Published: August 2020

Dense, H2- and CO2-resistant, oxygen-permeable 40 wt % Ce0.9Pr0.1O2–δ–60 wt % NdxSr1−xFe0.9Cu0.1O3−δdual-phase membranes were prepared in a one-pot process. These Nd-containing dual-phase membranes have up to 60% lower material costs than many classically used dual-phase materials. The Ce0.9Pr0.1O2−δ–Nd0.5Sr0.5Fe0.9Cu0.1O3−δ sample demonstrates outstanding activity and a regenerative ability in the presence of different atmospheres, especially in a reducing atmosphere and pure CO2 atmosphere in comparison with all investigated samples. The oxygen permeation fluxes across a Ce0.9Pr0.1O2−δ–Nd0.5Sr0.5Fe0.9Cu0.1O3−δ membrane reached up to 1.02 mL min−1 cm−2 and 0.63 mL min−1 cm−2 under an air/He and air/CO2 gradient at T = 1223 K, respectively. In addition, a Ce0.9Pr0.1O2–δ–Nd0.5Sr0.5Fe0.9Cu0.1O3–δ membrane (0.65 mm thickness) shows excellent long-term self-healing stability for 125 h. The repeated membrane fabrication delivered oxygen permeation fluxes had a deviation of less than 5%. These results indicate that this highly renewable dual-phase membrane is a potential candidate for long lifetime, high temperature gas separation applications and coupled reaction–separation processes.
Experimental Study on the Preparation of Cementing Materials by Direct Reduction Coupling of a Hematite-Carbon Base
Authors: Shi Ruimeng , Zhao Junxue , Li Xiaoming , Zou Chong , Cui Yaru , Qiu Guibao
Published: August 2020

The reduction of iron in hematite and process coupling of cementing material generated from gangue components are explored in this paper, and a technical proposal for preparing directly reduced iron and cementing materials considering the processes of energy and material flows is proposed. An experimental study preparing cementing materials, such as tricalcium silicate and dicalcium silicate, by roasting the components, was performed. In this study, hematite was used as the raw material and powdered carbon was added, as the reducing agent, with CaO; at the same time, the gangue components of iron ore were used as the principal raw materials for the process of directly reduced iron preparation by direct reduction of iron ore. The FactSage software package was used to perform thermodynamic calculations of the reduction of iron and its influence on the formation of tricalcium silicate and dicalcium silicate. The feasibility of the direct reduction of iron to elemental iron and preparation of cementing materials by roasting of gangue components under the studied thermodynamic conditions was discussed. Different temperature control strategies were used to verify the reaction coupling test. The results showed that zero-valent iron could be produced by roasting and reducing hematite under certain experimental conditions, and cementing materials, such as tricalcium silicate and dicalcium silicate, could be produced simultaneously by reacting the gangue components with CaO. Fe2O3 exerted an adverse effect on the formation of tricalcium silicate, and sufficient reduction of the iron was a precondition for the formation and stability of tricalcium silicate.
Determination of Constitutive Equation and Thermo–Mechanical Processing Map for Pure Iridium
Authors: Zhou Mi , Hu Rui , Yang Jieren , Wang Chuanjun , Wen Ming
Published: August 2020

Deformation behavior of pure iridium has been studied during thermal compression testing with the help of Gleeble-1500D in the temperature range of 1200 °C~1500 °C and strain rate range of 10−1 s−1~10−2 s−1. Resistance to deformation, microstructural evolution and hot workability of pure iridium have been used to analyze in detail. Frictional coefficient has been used to modify the experimental stress–strain curve of thermal compression test, and it has been found effective in reducing the influence of friction during thermo–mechanical testing. The hyperbolic sine constitutive equation of pure iridium has been established to give a material processing model for numerical simulation. A very high value of activation energy for iridium, 573 KJ/mol, clearly indicates that it is very hard to deform this material. The deformation mechanism of pure iridium is dependent upon temperature as well as strain rate. At low temperature and strain rate (temperature range of 1200 °C~1300 °C and strain rate range of 10−1 s−1~10−2 s−1), dynamic recovery is active while dynamic recrystallization becomes operative as temperature and stain rate are increased. On further increase in temperature and decrease in strain rate (temperature range of 1400 °C~1500 °C and strain rates of 10−2 s−1~10−3 s−1), abnormal grain growth takes place. On the basis of a constitutive model and processing map, suitable forming process parameters (temperature range of 1400 °C~1500 °C and strain rate range of 0.1 s−1~0.05 s−1) for pure iridium have been worked out.
On the Intergranular Corrosion Properties of Thin Ferritic Stainless Steel Sheets Welded by Fiber-Laser
Authors: Sommer Niklas , Kryukov Igor , Wolf Christian , Wiegand Michael , Kahlmeyer Martin , Böhm Stefan
Published: August 2020

In the present investigation, thin sheets of stabilized and unstabilized ferritic stainless steel were welded in butt joint configuration using irradiation of a 1070 nm fiber-laser. Using optical microscopy, the microstructural evolution upon alternating heat input was characterized. In addition to that, hardness and tensile tests were carried out on the specimens. Detailed focus was given to the intergranular corrosion properties, which were investigated on basis of the Strauss test with different times of exposure to the corrosive environment. Following these tests, the mechanical properties of the joints were characterized using tensile tests. A combination of the latter with an inspection by μ-CT analysis allows for the proposition of an intergranular corrosion rate with regard to the degradation of the joint strength.
Low-Cycle Fatigue and Fracture Behavior of Aluminized Stainless Steel AISI 321 for Solar Thermal Power Generation Systems
Authors: Li Wei , Yang Lei , Li Cong , Chen Huitao , Zuo Lu , Li Yide , Chen Jian , He Jianjun , Zhang Sheng-de
Published: August 2020

The microstructure, low-cycle fatigue property, and fracture behavior of as-received and aluminized steel were investigated at room temperature, respectively. The results reveal that the aluminized layer is mainly composed of three layers: (I) the external Al2O3 layer, (II) the transition Fe-Al mesophase layer, and (III) the diffusion layer with AlFe and AlCrFe phase. The microhardness of as-received steel lower than that of aluminized steel until the distance from aluminized layer is greater than 150 μm. Compared to the original steel, the aluminized steel exhibits lower stress amplitude and fatigue life, which is correlated to the surface integrity. According to the Coffin-Manson relationship, the fatigue-ductility coefficients for as-received and aluminized steel is 4.347 and 3.528, respectively. Fractographic analysis reveals that the fatigue cracks tend to nucleate at the coating and propagate through the grain boundaries apace.
COVID-19 Is a Multifaceted Challenging Pandemic Which Needs Urgent Public Health Interventions
Authors: Contini Carlo , Caselli Elisabetta , Martini Fernanda , Maritati Martina , Torreggiani Elena , Seraceni Silva , Vesce Fortunato , Perri Paolo , Rizzo Leonzio , Tognon Mauro
Published: August 2020

Until less than two decades ago, all known human coronaviruses (CoV) caused diseases so mild that they did not stimulate further advanced CoV research. In 2002 and following years, the scenario changed dramatically with the advent of the new more pathogenic CoVs, including Severe Acute Respiratory Syndome (SARS-CoV-1), Middle Eastern respiratory syndrome (MERS)-CoV, and the new zoonotic SARS-CoV-2, likely originated from bat species and responsible for the present coronavirus disease (COVID-19), which to date has caused 15,581,007 confirmed cases and 635,173 deaths in 208 countries, including Italy. SARS-CoV-2 transmission is mainly airborne via droplets generated by symptomatic patients, and possibly asymptomatic individuals during incubation of the disease, although for the latter, there are no certain data yet. However, research on asymptomatic viral infection is currently ongoing worldwide to elucidate the real prevalence and mortality of the disease. From a clinical point of view, COVID-19 would be defined as “COVID Planet “ because it presents as a multifaceted disease, due to the large number of organs and tissues infected by the virus. Overall, based on the available published data, 80.9% of patients infected by SARS-CoV-2 develop a mild disease/infection, 13.8% severe pneumonia, 4.7% respiratory failure, septic shock, or multi-organ failure, and 3% of these cases are fatal, but mortality parameter is highly variable in different countries. Clinically, SARS-CoV-2 causes severe primary interstitial viral pneumonia and a “cytokine storm syndrome”, characterized by a severe and fatal uncontrolled systemic inflammatory response triggered by the activation of interleukin 6 (IL-6) with development of endothelitis and generalized thrombosis that can lead to organ failure and death. Risk factors include advanced age and comorbidities including hypertension, diabetes, and cardiovascular disease. Virus entry occurs via binding the angiotensin-converting enzyme 2 (ACE2) receptor present in almost all tissues and organs through the Spike (S) protein. Currently, SARS-CoV-2 infection is prevented by the use of masks, social distancing, and improved hand hygiene measures. This review summarizes the current knowledge on the main biological and clinical features of the SARS-CoV-2 pandemic, also focusing on the principal measures taken in some Italian regions to face the emergency and on the most important treatments used to manage the COVID-19 pandemic.
A Process Mineralogical Evaluation of Chromite at the Nkomati Nickel Mine, Uitkomst Complex, South Africa
Authors: Dzvinamurungu Thomas , Rose Derek Hugh , Viljoen Karel Stephanus , Mulaba-Bafubiandi Antoine Floribert
Published: August 2020

A process mineralogical study based on three texturally and mineralogically different chromite-bearing ore types at the Nkomati nickel mine was undertaken, with focus on chromite. Chromite is a by-product of the Ni-Cu-Co-PGE ore at Nkomati Nickel mine. These being the PCMZ_MG (medium-grade Ni-Cu sulphide silicate ore with disseminated chromite), PCMZ_HG (high-grade Ni-Cu sulphide silicate ore containing disseminated chromite) and MCHR (massive chromite unit) ore types. These were processed using benchtop flotation followed by gravity concentration using a shaking table at different grind sizes. Quantitative mineralogical data was obtained using a 600F Mineral Liberation Analyser for the unprocessed and processed ores at three selected target grinds. The Mineral Liberation Analyser data indicated that increased milling does not relate to increased chromite grades and recoveries, particularly for the disseminated PCMZ type ores based on laboratory-scale gravity concentration. The recovery is controlled largely by the chromite chemistry. The results also showed that the MCHR samples that underwent a pre-flotation stage before gravity separation had better Cr2O3 grades (45% to 47%) and recoveries (52% to 61%) than MCHR ore that did not undergo a pre-flotation stage, which recorded grades ranging from 44% to 46% and recoveries ranging from 43% to 60%. This holds promise for the blending of MCHR ores with the PCMZ ores. The PCMZ ores also displayed better Cr2O3 grades and recoveries at coarser grinds. The optimal target grind to process all three ore types is a P80 of 75 μm, which is the current grind size employed at Nkomati Nickel mine. Due to the low nickel price and grade the Nkomati Nickel mine is currently under care and maintenance.