bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulation of the Cardiac Myocyte Action Potential by the Magnesium-Sensitive TRPM6 and TRPM7-like Current
Authors: Gwanyanya Asfree , Andriulė Inga , Istrate Bogdan M. , Easmin Farjana , Mubagwa Kanigula , Mačianskienė Regina
Published: August 2021

The cardiac Mg2+-sensitive, TRPM6, and TRPM7-like channels remain undefined, especially with the uncertainty regarding TRPM6 expression in cardiomyocytes. Additionally, their contribution to the cardiac action potential (AP) profile is unclear. Immunofluorescence assays showed the expression of the TRPM6 and TRPM7 proteins in isolated pig atrial and ventricular cardiomyocytes, of which the expression was modulated by incubation in extracellular divalent cation-free conditions. In patch clamp studies of cells dialyzed with solutions containing zero intracellular Mg2+ concentration ([Mg2+]i) to activate the Mg2+-sensitive channels, raising extracellular [Mg2+] ([Mg2+]o) from the 0.9-mM baseline to 7.2 mM prolonged the AP duration (APD). In contrast, no such effect was observed in cells dialyzed with physiological [Mg2+]i. Under voltage clamp, in cells dialyzed with zero [Mg2+]i, depolarizing ramps induced an outward-rectifying current, which was suppressed by raising [Mg2+]o and was absent in cells dialyzed with physiological [Mg2+]i. In cells dialyzed with physiological [Mg2+]i, raising [Mg2+]o decreased the L-type Ca2+ current and the total delayed-rectifier current but had no effect on the APD. These results suggest a co-expression of the TRPM6 and TRPM7 proteins in cardiomyocytes, which are therefore the molecular candidates for the native cardiac Mg2+-sensitive channels, and also suggest that the cardiac Mg2+-sensitive current shortens the APD, with potential implications in arrhythmogenesis.
Genome-wide Analysis of Basic Helix-Loop-Helix Family Genes and Expression Analysis in Response to Drought and Salt Stresses in Hibiscus hamabo Sieb. et Zucc
Authors: Ni Longjie , Wang Zhiquan , Fu Zekai , Liu Dina , Yin Yunlong , Li Huogen , Gu Chunsun
Published: August 2021

The basic helix-loop-helix (bHLH) family of transcription factors is one of the most significant and biggest in plants. It is involved in the regulation of both growth and development, as well as stress response. Numerous members of the bHLH family have been found and characterized in woody plants in recent years. However, no systematic study of the bHLH gene family has been published for Hibiscus hamabo Sieb. et Zucc. In this research, we identified 162 bHLH proteins (HhbHLHs) from the genomic and transcriptomic datasets of H. hamabo, which were phylogenetically divided into 19 subfamilies. According to a gene structural study, the number of exon-introns in HhbHLHs varied between zero and seventeen. MEME research revealed that the majority of HhbHLH proteins contained three conserved motifs, 1, 4, and 5. The examination of promoter cis-elements revealed that the majority of HhbHLH genes had several cis-elements involved in plant growth and development and abiotic stress responses. In addition, the overexpression of HhbHLH2 increased salt and drought stress tolerance in Arabidopsis.
Integrated Metabolomic and Transcriptomic Analysis Reveals the Flavonoid Regulatory Network by Eutrema EsMYB90
Authors: Qi Yuting , Li Chuanshun , Duan Chonghao , Gu Caihong , Zhang Quan
Published: August 2021

Flavonoids are representative secondary metabolites with different metabolic functions in plants. Previous study found that ectopic expression of EsMYB90 from Eutremasalsugineum could strongly increase anthocyanin content in transgenic tobacco via regulating the expression of anthocyanin biosynthesis genes. In the present research, metabolome analysis showed that there existed 130 significantly differential metabolites, of which 23 metabolites enhanced more than 1000 times in EsMYB90 transgenic tobacco leaves relative to the control, and the top 10 of the increased metabolites included caffeic acid, cyanidin O-syringic acid, myricetin and naringin. A total of 50 markedly differential flavonoids including flavones (14), flavonols (13), flavone C-glycosides (9), flavanones (7), catechin derivatives (5), anthocyanins (1) and isoflavone (1) were identified, of which 46 metabolites were at a significantly enhanced level. Integrated analysis of metabolome and transcriptome revealed that ectopic expression of EsMYB90 in transgenic tobacco leaves is highly associated with the prominent up-regulation of 16 flavonoid metabolites and the corresponding 42 flavonoid biosynthesis structure genes in phenylpropanoid/flavonoid pathways. Dual luciferase assay documented that EsMYB90 strongly activated the transcription of NtANS and NtDFR genes via improving their promoter activity in transiently expressed tobacco leaves, suggesting that EsMYB90 functions as a key regulator on anthocyanin and flavonoid biosynthesis. Taken together, the crucial regulatory role of EsMYB90 on enhancing many flavonoid metabolite levels is clearly demonstrated via modulating flavonoid biosynthesis gene expression in the leaves of transgenic tobacco, which extends our understanding of the regulating mechanism of MYB transcription factor in the phenylpropanoid/flavonoid pathways and provides a new clue and tool for further investigation and genetic engineering of flavonoid metabolism in plants.
Switching the Local Symmetry from D5h to D4h for Single-Molecule Magnets by Non-Coordinating Solvents
Authors: Ding Xia-Li , Luo Qian-Cheng , Zhai Yuan-Qi , Zhang Qian , Tian Lei , Zhang Xinliang , Ke Chao , Zhang Xu-Feng , Lv Yi , Zheng Yan-Zhen
Published: August 2021

A solvent effect towards the performance of two single-molecule magnets (SMMs) was observed. The tetrahydrofuran and toluene solvents can switch the equatorial coordinated 4-Phenylpyridine (4-PhPy) molecules from five to four, respectively, in [Dy(OtBu)2(4-PhPy)5]BPh41 and Na{[Dy(OtBu)2(4-PhPy)4][BPh4]2}∙2thf∙hex 2. This alternation significantly changes the local coordination symmetry of the Dy(III) center from D5h to D4h for 1 and 2, seperately. Magnetic studies show that the magnetic anisotropy energy barrier of 2 is higher than that of 1, while the relation of blocking temperature is just on the contrary due to the symmetry effect. The calculations of the electrostatic potential successfully explained the driving force of solvents for the molecular structure change, confirming the feasibility of adjusting the performance of SMMs via diverse solvents.
Comparative Morphology of the Stinger in Social Wasps (Hymenoptera: Vespidae)
Authors: Bissessarsingh Mario , Starr Christopher K.
Published: August 2021

The physical features of the stinger are compared in 51 species of vespid wasps: 4 eumenines and zethines, 2 stenogastrines, 16 independent-founding polistines, 13 swarm-founding New World polistines, and 16 vespines. The overall structure of the stinger is remarkably uniform within the family. Although the wasps show a broad range in body size and social habits, the central part of the venom-delivery apparatus—the sting shaft—varies only to a modest extent in length relative to overall body size. What variation there is shows no apparent correlation with social habits. This is consistent with the hypothesis that stinger size is constrained by the demands of a flight-worthy body. The sting lancets bear distinct, acute barbs in all examined species except in members of the Stenogastrinae. Barbs vary considerably among species in number, their summed lengths, and the relative degree of serration (summed length relative to lancet width). Where they are numerous and strong, it increases the likelihood of the stinger remaining fatally embedded in the skin of a vertebrate adversary (sting autotomy). Although an index that combines the number and strength of barbs is a more natural measure of overall serration, the number of barbs alone is almost as good a predictor of the likelihood of sting autotomy. Across the family as a whole, the tendency to sting autotomy is concentrated in the swarm-founding New World polistines.
How to Achieve Near-Normal Visual Acuity with Bevacizumab in Diabetic Macular Edema Patients
Authors: Sędziak-Marcinek Bogumiła , Wylęgała Adam , Chełmecka Elżbieta , Wylęgała Edward , Teper Sławomir
Published: August 2021

Patients suffering from diabetic retinopathy (DR) and diabetic macular edema (DME) are inherently interested in achieving normal or near-normal visual acuity. The study aimed to investigate factors influencing the visual acuity achieved by DME patients after bevacizumab (IVB) treatment. 98 patients (98 eyes) diagnosed with DR and DME underwent IVB treatment (9 injections/12 months). Patients were diagnosed and monitored using swept-source optical coherence tomography (SS-OCT), ultra-wide-field fluorescein angiography (UWFFA) and Early Treatment Diabetic Retinopathy Study (ETDRS) chart testing. We assessed macular central subfield thickness (CST), non-proliferative diabetic retinopathy (NPDR) indicators and best-corrected visual acuity (BCVA). After the treatment, patients were divided into BCVA≤75 and BCVA>75 groups. The IVB therapy increased the number of ETDRS letters read by about 9 and 8 in the BCVA≤75 and the BCVA>75 group, respectively. Before and after treatment, the BCVA>75 group had lower CST than the BCVA≤75 group. The treatment reduced macular CST by 177 μm in the BCVA≤75 group and only by 93 μm in the BCVA>75 group. Total non-perfusion area (NPA) decreased in both BCVA score groups after IVB therapy. Normal or near-normal vision can be achieved with IVB treatment, provided it starts when visual acuity is not significantly reduced yet. The ophthalmic screening of DR patients should also target those with relatively high visual acuity.
In the Aftermath of Acute Hospitalization for Traumatic Brain Injury: Factors Associated with the Direct Pathway into Specialized Rehabilitation
Authors: Tverdal Cathrine , Andelic Nada , Helseth Eirik , Brunborg Cathrine , Rønning Pål , Hellstrøm Torgeir , Røe Cecilie , Aarhus Mads
Published: August 2021

Previous research has demonstrated that early initiation of rehabilitation and direct care pathways improve outcomes for patients with severe traumatic brain injury (TBI). Despite this knowledge, there is a concern that a number of patients are still not included in the direct care pathway. The study aim was to provide an updated overview of discharge to rehabilitation following acute care and identify factors associated with the direct pathway. We analyzed data from the Oslo TBI Registry—Neurosurgery over a five-year period (2015–2019) and included 1724 adults with intracranial injuries. We described the patient population and applied multivariable logistic regression to investigate factors associated with the probability of entering the direct pathway. In total, 289 patients followed the direct pathway. For patients with moderate–severe TBI, the proportion increased from 22% to 35% during the study period. Significant predictors were younger age, low preinjury comorbidities, moderate–severe TBI and disability due to TBI at the time of discharge. In patients aged 18–29 years, 53% followed the direct pathway, in contrast to 10% of patients aged 65–79 years (moderate–severe TBI). This study highlights the need for further emphasis on entering the direct pathway to rehabilitation, particularly for patients aged >64 years.
Predictors of Hypoxemia and Related Adverse Outcomes in Patients Hospitalized with COVID-19: A Double-Center Retrospective Study
Authors: Asleh Rabea , Asher Elad , Yagel Oren , Samuel Tal , Elbaz-Greener Gabby , Wolak Arik , Durst Ronen , Ben-Chetrit Eli , Nir-Paz Ran , Helviz Yigal , Rubin Limor , Tvito Ariella , Glikson Michael , Amir Offer
Published: August 2021

Hypoxemia is a hallmark of coronavirus disease 2019 (COVID-19) severity. We sought to determine predictors of hypoxemia and related adverse outcomes among patients hospitalized with COVID-19 in the two largest hospitals in Jerusalem, Israel, from 9 March through 16 July 2020. Patients were categorized as those who developed reduced (<94%) vs. preserved (≥94%) arterial oxygen saturation (SpO2) within the first 48 h after arrival to the emergency department. Overall, 492 hospitalized patients with COVID-19 were retrospectively analyzed. Patients with reduced SpO2 were significantly older, had more comorbidities, higher body surface area (BSA) and body mass index (BMI), lower lymphocyte counts, impaired renal function, and elevated liver enzymes, c-reactive protein (CRP), and D-dimer levels as compared to those with preserved SpO2. In the multivariable regression analysis, older age (odds ratio (OR) 1.02 per year, p < 0.001), higher BSA (OR 1.16 per 0.10 m2, p = 0.003) or BMI (OR 1.05 per 1 kg/m2, p = 0.011), lower lymphocyte counts (OR 1.72 per 1 × 103/μL decrease, p = 0.002), and elevated CRP (1.11 per 1 mg/dL increase, p < 0.001) were found to be independent predictors of low SpO2. Severe hypoxemia requiring ventilatory support, older age, and pre-existing comorbidities, including underlying renal dysfunction and heart failure, were found to be significantly associated with in-hospital mortality. These findings suggest that assessment of predictors of hypoxemia early at the time of hospitalization with COVID-19 may be helpful in risk stratification and management.
Thyroid Cancer: Toward Surgical Evolution
Authors: D’Amore Annamaria , Patrone Renato , Docimo Ludovico , Conzo Giovanni , Lombardi Celestino Pio
Published: August 2021

It has been more than five years since the American Thyroid Association (ATA) and the Italian consensus on thyroid cancer was published [...]
Failure of High-Flow Nasal Cannula Therapy in Pneumonia and Non-Pneumonia Sepsis Patients: A Prospective Cohort Study
Authors: Kim Eunhye , Jeon Kyeongman , Oh Dong Kyu , Cho Young-Jae , Hong Sang-Bum , Lee Yeon Joo , Lee Sang-Min , Suh Gee Young , Park Mi-Hyeon , Lim Chae-Man , Park Sunghoon ,   on behalf of the Korean Sepsis Alliance (KSA) Investigators
Published: August 2021

Despite the increasing use of high-flow nasal cannulas (HFNCs) to treat critically ill patients, data on their effectiveness for sepsis patients remains very limited. We studied a prospective cohort of sepsis patients from the Korean Sepsis Registry (18 intensive care units (ICUs)). Patients started on HFNC therapy for hypoxemia within the first three ICU days were enrolled. HFNC failure was defined as intubation or ICU death, and the primary outcome was early HFNC failure occurring within 72 h of HFNC initiation. Of 901 patients with sepsis admitted to the ICU, 206 who received HFNC therapy were finally included (117 with pneumonia vs. 89 with non-pneumonia sepsis; median age, 71.0 (63.0–78.0) years; PaO2/FiO2 ratio, 160.2 (107.9–228.2) mm Hg; septic shock, n = 81 (39.3%)). During HFNC therapy, 72 (35.0%) patients were intubated and 51 (24.8%) died. HFNC failure developed in 95 (46.1%) patients, and among them, early failure rate was 85.3% (81/95). On multivariate analysis, an immunocompromised state (odds ratio (OR) = 2.730), use of a combination of antibiotics (OR = 0.219), and the PaO2/FiO2 ratio (OR = 0.308) were significantly associated with early HFNC failure in pneumonia sepsis patients. However, in non-pneumonia sepsis patients, lactate levels (OR = 1.532) were significantly associated with early HFNC failure. In conclusion, a high proportion of sepsis patients experience HFNC failure, usually within 72 h after therapy initiation, which emphasizes the importance of close monitoring. Furthermore, unlike in pneumonia sepsis, organ failure (i.e., lactate) might serve as a prognostic marker in non-pneumonia sepsis (i.e., type IV respiratory failure).
Zygomatic Implants Placed in Immediate Function through Extra-Maxillary Surgical Technique and 45 to 60 Degrees Angulated Abutments for Full-Arch Rehabilitation of Extremely Atrophic Maxillae: Short-Term Outcome of a Retrospective Cohort
Authors: Lopes Armando , de Araújo Nobre Miguel , Ferro Ana , Moura Guedes Carlos , Almeida Ricardo , Nunes Mariana
Published: August 2021

The use of new devices for the rehabilitation of the severely atrophic maxillae needs validation. We aimed to report the short-term outcome of severely atrophic jaws rehabilitated with zygomatic implants with no implant head angulation placed extramaxillary in conjunction with standard implants. Forty-four patients were consecutively included with 77 zygomatic implants (31 abutments of 45 degrees and 46 abutments of 60 degrees) and 115 standard implants. Outcome measures were prosthetic survival, implant/abutment success, complications, modified plaque index (mPLI), modified bleeding index (mBI), mucosal seal efficacy evaluation (MSEE) >4 mm, and Zygomatic implants classification level (ZICL). Two patients (4.5%) were lost to follow-up. No prosthesis was lost; one patient lost one zygomatic implant; two angulated abutments of 60 degrees needed to be replaced in one patient due to an aesthetic complaint; rendering a cumulative success rate at 2-years of 95.3% and 95.9% using patient and implant/abutment as unit of analysis, respectively. Mechanical and biological complications occurred in 13 and six patients, respectively; all resolved. The median mPLI and mBI was 1; MSEE > 4 mm occurred in 17% and 21% of patients at 1- and 2-years, respectively; ZICL1 was registered in 80% of patients. The current protocol enabled good short-term outcomes.
Improvement of Mechanical Strength of Tissue Engineering Scaffold Due to the Temperature Control of Polymer Blend Solution
Authors: Pangesty Azizah Intan , Todo Mitsugu
Published: August 2021

Polymeric scaffolds made of PCL/PLCL (ratio 1:3, respectively) blends have been developed by using the Thermally Induced Phase Separation (TIPS) process. A new additional technique has been introduced in this study by applying pre-heat treatment to the blend solution before the TIPS process. The main objective of this study is to evaluate the influence of the pre-heat treatment on mechanical properties. The mechanical evaluation showed that the mechanical strength of the scaffolds (including tensile strength, elastic modulus, and strain) improved as the temperature of the polymer blend solution increased. The effects on the microstructure features were also observed, such as increasing strut size and differences in phase separation morphology. Those microstructure changes due to temperature control contributed to the increasing of mechanical strength. The in vitro cell study showed that the PCL/PLCL blend scaffold exhibited better cytocompatibility than the neat PCL scaffold, indicated by a higher proliferation at 4 and 7 days in culture. This study highlighted that the improvement of the mechanical strength of polymer blends scaffolds can be achieved using a very versatile way by controlling the temperature of the polymer blend solution before the TIPS process.
Chained Data Acquisition and Transmission System Protype for Cabled Seafloor Earthquake Observatory
Authors: Qiao Jingyang , Liu Wu , Liu Jingquan , Zhou Jianping
Published: August 2021

Seafloor observatories can provide long-term, real-time submarine monitoring data, which has great significance for the study of major scientific technology in marine science, especially in the seafloor earthquake observation. The chained submarine data sampling and transmission system is the prototype and foundation of cabled seafloor earthquake observatories. This paper designs and builds a chained data sampling and transmission system (SQSTS) based on Zynq-7000 Soc (System on chip) and clock synchronization. At the beginning, we realized high-precision submarine data (24 bit) sampling based on Zynq-7000 Soc and ADS 1256. Using the PPS (Pulse per second) signal provided by the P88 1588 PTP (Precise time protocol) clock synchronization board and the inner crystal oscillator of the Zynq-7000 Soc, the time stamp up to the microsecond level, for the seismic data sampled in each seismometer node can support subsequent inversion of seismic data. In addition, a high-speed data transmission link connecting nodes in SQSTS, which is based on the Gigabit transceiver and optical cable, has been investigated. The transmission link has been realized by using the Aurora IP core. The theoretical calculations indicate that the data transmission bus bandwidth can reach 4 Gbps, while in the meantime its reliability has been proved by experiments. The experimental results show that the system owns the characteristics of high data sampling accuracy, stable and reliable high-speed transmission, and has promising application prospects.
Smuts to the Power of Three: Biotechnology, Biotrophy, and Basic Biology
Authors: Schirawski Jan , Perlin Michael H. , Saville Barry J.
Published: August 2021

Smut fungi are a large group of mainly biotrophic plant pathogens, many of which cause disease on cereal crops [...]
Risk Factors for Recanalization after Coil Embolization
Authors: Wiśniewski Karol , Tyfa Zbigniew , Tomasik Bartłomiej , Reorowicz Piotr , Bobeff Ernest J. , Posmyk Bartłomiej J. , Hupało Marlena , Stefańczyk Ludomir , Jóźwik Krzysztof , Jaskólski Dariusz J.
Published: August 2021

The aim of our study was to identify risk factors for recanalization 6 months after coil embolization using clinical data followed by computational fluid dynamics (CFD) analysis. Methods: Firstly, clinical data of 184 patients treated with coil embolization were analyzed retrospectively. Secondly, aneurysm models for high/low recanalization risk were generated based on ROC curves and their cut-off points. Afterward, CFD was utilized to validate the results. Results: In multivariable analysis, aneurysm filling during the first embolization was an independent risk factor whilst packing density was a protective factor of recanalization after 6 months in patients with aSAH. For patients with unruptured aneurysms, packing density was found to be a protective factor whilst the aneurysm neck size was an independent risk factor. Complex flow pattern and multiple vortices were associated with aneurysm shape and were characteristic of the high recanalization risk group. Conclusions: Statistical analysis suggested that there are various factors influencing recanalization risk. Once certain values of morphometric parameters are exceeded, a complex flow with numerous vortices occurs. This phenomenon was revealed due to CFD investigations that validated our statistical research. Thus, the complex flow pattern itself can be treated as a relevant recanalization predictor.
ILB® Attenuates Clinical Symptoms and Serum Biomarkers of Oxidative/Nitrosative Stress and Mitochondrial Dysfunction in Patients with Amyotrophic Lateral Sclerosis
Authors: Lazzarino Giacomo , Mangione Renata , Belli Antonio , Di Pietro Valentina , Nagy Zsuzsanna , Barnes Nicholas M. , Bruce Lars , Ropero Bernardo M. , Persson Lennart I. , Manca Benedetta , Saab Miriam Wissam , Amorini Angela M. , Tavazzi Barbara , Lazzarino Giuseppe , Logan Ann
Published: August 2021

Oxidative/nitrosative stress and mitochondrial dysfunction is a hallmark of amyotrophic lateral sclerosis (ALS), an invariably fatal progressive neurodegenerative disease. Here, as an exploratory arm of a phase II clinical trial (EudraCT Number 2017-005065-47), we used high performance liquid chromatography(HPLC) to investigate changes in the metabolic profiles of serum from ALS patients treated weekly for 4 weeks with a repeated sub-cutaneous dose of 1 mg/kg of a proprietary low molecular weight dextran sulphate, called ILB®. A significant normalization of the serum levels of several key metabolites was observed over the treatment period, including N-acetylaspartate (NAA), oxypurines, biomarkers of oxidative/nitrosative stress and antioxidants. An improved serum metabolic profile was accompanied by significant amelioration of the patients’ clinical conditions, indicating a response to ILB® treatment that appears to be mediated by improvement of tissue bioenergetics, decrease of oxidative/nitrosative stress and attenuation of (neuro)inflammatory processes.
Historical GIS as a Tool for Monitoring, Preserving and Planning Forest Landscape: A Case Study in a Mediterranean Region
Authors: Cillis Giuseppe , Statuto Dina , Picuno Pietro
Published: August 2021

In order to assess the dynamics of forests and the effectiveness of their management strategies, it is necessary to develop monitoring systems based on qualitative and quantitative tools for their conservation, valorization and restoration. This approach is particularly important for areas that have undergone intense anthropogenic transformations in the last century. In order to do this, it is first necessary to apply a chronological methodology based on historical GIS that allows the integration of different types of geodata. As a result of constantly evolving spatial analysis tools, the monitoring of landscape forest evolution is increasingly more effective and complete. Using as a case study a region representative of common processes of other Mediterranean areas (Southern Italy–Basilicata region), a diachronic analysis of 156 years was applied to evaluate the forest landscape dynamics. Starting from historical cartographies to remotely sensed data available online, a GIS-based approach was implemented to evaluate the spatial and statistical variations of the forest landscape. In this way, it was possible to assess how much, where and how the forest landscape has changed in order to provide a methodology to support more detailed and sectoral studies.
Bibliometric Mapping of Research on Magic Towns of Mexico
Authors: Flores-Romero Martha B. , Pérez-Romero Miriam E. , Álvarez-García José , del Río-Rama María de la Cruz
Published: August 2021

The tourism program “Pueblos Mágicos” was created in 2001 by the Mexican Secretary of Tourism (Sectur), together with its brand, with the aim of promoting tourism by preserving secular and ancestral traditions, as well as revitalizing cities and towns that make great efforts to protect and safeguard their cultural wealth. In this context, the aim of this research work is to show the current state of scientific research carried out within the context of the Magic Towns of Mexico. The work methodology is based on the bibliometric analysis of the scientific production indexed in two main international databases: Web of Science and Scopus. The application of this technique will make it possible to obtain a scientific mapping of the production (growth, researchers in the subject, production impact through the number of citations, network analysis, etc.), with the aim of observing the evolution in the generation of knowledge regarding this tourism development tool that acts as a distinctive brand for tourism in Mexico. This mapping is useful for researchers as it provides information on the research carried out so far, allowing them to identify gaps to work on in their future research work. The systematic search process identified 52 articles. The results indicate that the research carried out in this context is incipient, with few researchers addressing the subject on a continuous basis and most of them being transient researchers with a single article. Most of the research was approached from the perspective of cultural heritage, cultural resources, inherited resources, cultural tourism, public policy, local development and sustainable tourism, and sustainable development. In light of the number of articles published, all of these can be considered to be incipient lines of research.
Space Radiation Protection Countermeasures in Microgravity and Planetary Exploration
Authors: Montesinos Carlos A. , Khalid Radina , Cristea Octav , Greenberger Joel S. , Epperly Michael W. , Lemon Jennifer A. , Boreham Douglas R. , Popov Dmitri , Gorthi Gitika , Ramkumar Nandita , Jones Jeffrey A.
Published: August 2021

Background: Space radiation is one of the principal environmental factors limiting the human tolerance for space travel, and therefore a primary risk in need of mitigation strategies to enable crewed exploration of the solar system. Methods: We summarize the current state of knowledge regarding potential means to reduce the biological effects of space radiation. New countermeasure strategies for exploration-class missions are proposed, based on recent advances in nutrition, pharmacologic, and immune science. Results: Radiation protection can be categorized into (1) exposure-limiting: shielding and mission duration; (2) countermeasures: radioprotectors, radiomodulators, radiomitigators, and immune-modulation, and; (3) treatment and supportive care for the effects of radiation. Vehicle and mission design can augment the overall exposure. Testing in terrestrial laboratories and earth-based exposure facilities, as well as on the International Space Station (ISS), has demonstrated that dietary and pharmacologic countermeasures can be safe and effective. Immune system modulators are less robustly tested but show promise. Therapies for radiation prodromal syndrome may include pharmacologic agents; and autologous marrow for acute radiation syndrome (ARS). Conclusions: Current radiation protection technology is not yet optimized, but nevertheless offers substantial protection to crews based on Lunar or Mars design reference missions. With additional research and human testing, the space radiation risk can be further mitigated to allow for long-duration exploration of the solar system.
The Effect of Type-I Photoinitiators on the Kinetics of the UV-Induced Cotelomerization Process of Acrylate Monomers and Properties of Obtained Pressure-Sensitive Adhesives
Authors: Kowalczyk Agnieszka , Weisbrodt Mateusz , Schmidt Beata , Kraśkiewicz Agata
Published: August 2021

A new method of solvent-free acrylic pressure-sensitive adhesives (PSAs) based on UV-induced cotelomerization products was presented. The key acrylic monomers (i.e., n-butyl acrylate and acrylic acid) with copolymerizable photoinitiator 4-acrylooxybenzophenone in the presence of a selected chain transfer agent (tetrabromomethane, TBM) were used in the UV-cotelomerization process. Moreover, two kinds of UV-photoinitiators (α-hydroxyalkylphenones, HPs and acylphosphine oxides, APOs) were tested. Photo-DSC, viscosity, thermogravimetric, and GPC measurements for cotelomers were performed. The kinetics study revealed that the systems with APOs, especially Omnirad 819 and Omnirad TPO, were characterized by a much higher reaction rate and greater initiation efficiency than HPs systems were. Additionally, the APO-based syrups exhibited a higher solid content (ca. 60–96 wt%), a higher dynamic viscosity (5–185 Pa·s), but slightly lower molecular weights (Mn and Mw) compared to HP syrups. However, better self-adhesive features (i.e., adhesion and tack) were observed for PSAs based on cotelomers syrups obtained using APOs with lower solid contents (55–80 wt%). It was found that as the solids content (i.e., monomers conversion) increased the adhesion, the tack and glass transition temperature decreased and the type and amount of photoinitiator had no effect on polydispersity. Most of the obtained PSAs were characterized by excellent cohesion, both at 20 °C and 70 °C.
Recovery of Metals from Heat-Treated Printed Circuit Boards via an Enhanced Gravity Concentrator and High-Gradient Magnetic Separator
Authors: Xian Yushuai , Tao Youjun , Ma Fangyuan , Zhou You
Published: August 2021

The recovery and reuse of waste printed circuit boards (PCBs) has attracted more and more attention from global researchers, as recycling of waste PCB metals is of great significance to the rational utilization of metal material resources. This study puts forward a clean and economical method in which enhanced gravity separation and wet high-gradient magnetic separation were combined to recover waste PCBs with heat treatment at a temperature of 240 °C. The heat treatment could improve the metal liberation effect of the PCBs, and the thermal behavior was measured by thermogravimetric analysis (TGA). The pyrolysis of the non-metal fraction (NMF) began around 300 °C, and the glass transition temperature of epoxy resin was 135.17 °C. The enhanced gravity separation technique was used for the separation of metals and NMF under the compound force field. The metals grade of the gravity concentrates fraction (GRF) was 82.97% under the optimal conditions, and the metals recovery reached 90.55%. A wet high-gradient magnetic separator was applied to classify the GRF into magnetic (MA) and non-magnetic (NMA) fractions, which could achieve iron and copper enrichment. After the three stages combined process, the copper and iron grades of the NMA and MA fractions were 70.17% and 73.42%, and the recovery reached 74.02% and 78.11%, respectively.
Alkali-Activated Mortars with Recycled Fines and Hemp as a Sand
Authors: Pawluczuk Edyta , Kalinowska-Wichrowska Katarzyna , Soomro Mahfooz
Published: August 2021

Nowadays, effective and eco-friendly ways of using waste materials that could replace natural resources (for example, sand) in the production of concrete composites are highly sought. The article presents the results of research on geopolymer composites produced from two types of waste materials—hemp and fine fractions recovered from recycled cement concrete, which were both used as a replacement for standard sand. A total of two research experiments were conducted. In the first experiment, geopolymer mortars were made using the standard sand, which was substituted with recycled fines, from 0% to 30% by weight. In the second study, geopolymers containing organic filler were designed, where the variables were (i) the amount of hemp and the percent of sand by volume (0%, 2.5%, and 5%) and(ii) the amount of hydrated lime and the percent of fly ash (by weight) (0%, 2%, and 4%) that were prepared. In both cases, the basic properties of the prepared composites were determined, including their flexural strength, compressive strength, volume density in a dry and saturated state, and water absorption by weight. Observations of the microstructure of the geopolymers using an electron and optical microscope were also conducted. The test results show that both materials (hemp and recycled fines) and the appropriate selection of the proportions of mortar components and can produce composites with better physical and mechanical properties compared to mortars made of only natural sand. The detailed results show that recycled fines (RF) can be a valuable substitute for natural sand. The presence of 30% recycled fines (by weight) as a replacement for natural sand in the alkali-activated mortar increased its compressive strength by 26% and its flexural strength by 9% compared to control composites (compared to composites made entirely of sand without its alternatives). The good dispersion of both materials in the geopolymer matrix probably contributed to filling of the pores and reducing the water absorption of the composites. The use of hemp as a sand substitute generally caused a decrease in the strength properties of geopolymer mortar, but satisfactory results were achieved with the substitution of 2.5% hemp (by volume) as a replacement for standard sand (40 MPa for compressive strength, and 6.3MPa for flexural strength). Both of these waste materials could be used as a substitute for natural sand and are examples of an eco-friendly and sustainable substitution to save natural, non-renewable resources.
Oxygen Adsorption Induced Superconductivity in Ultrathin FeTe Film on SrTiO3(001)
Authors: Ren Wei , Ru Hao , Peng Kun , Li Huifang , Lu Shuai , Chen Aixi , Wang Pengdong , Fang Xinwei , Li Zhiyun , Huang Rong , Wang Li , Wang Yihua , Li Fangsen
Published: August 2021

The phenomenon of oxygen incorporation-induced superconductivity in iron telluride (Fe1+yTe, with antiferromagnetic (AFM) orders) is intriguing and quite different from the case of FeSe. Until now, the microscopic origin of the induced superconductivity and the role of oxygen are far from clear. Here, by combining in situ scanning tunneling microscopy/spectroscopy (STM/STS) and X-ray photoemission spectroscopy (XPS) on oxygenated FeTe, we found physically adsorbed O2 molecules crystallized into c (2/3 × 2) structure as an oxygen overlayer at low temperature, which was vital for superconductivity. The O2 overlayer were not epitaxial on the FeTe lattice, which implied weak O2 –FeTe interaction but strong molecular interactions. The energy shift observed in the STS and XPS measurements indicated a hole doping effect from the O2 overlayer to the FeTe layer, leading to a superconducting gap of 4.5 meV opened across the Fermi level. Our direct microscopic probe clarified the role of oxygen on FeTe and emphasized the importance of charge transfer effect to induce superconductivity in iron-chalcogenide thin films.
Bobbin Tool Friction Stir Welding of Aluminum Thick Lap Joints: Effect of Process Parameters on Temperature Distribution and Joints’ Properties
Authors: Ahmed Mohamed M. Z. , Habba Mohamed I. A. , El-Sayed Seleman Mohamed M. , Hajlaoui Khalil , Ataya Sabbah , Latief Fahamsyah H. , EL-Nikhaily Ahmed E.
Published: August 2021

Bobbin tool friction stir welding (BT-FSW) is characterized by a fully penetrated pin and double-sided shoulder that promote symmetrical solid-state joints. However, control of the processing parameters to obtain defect-free thick lap joints is still difficult and needs more effort. In this study, the BT-FSW process was used to produce 10 mm AA1050-H14 similar lap joints. A newly designed bobbin tool (BT) with three different pin geometries (cylindrical, square, and triangular) and concave shoulders profile was designed, manufactured, and applied to produce the Al alloy lap joints. The experiments were carried out at a constant tool rotation speed of 600 rpm and a wide range of various welding travel speeds of 200, 400, 600, 800, and 1000 mm/min. The generated temperature during the BT-FSW process was recorded and analyzed at the joints’ center line, and at both advancing and retreating sides. Visual inspection, macrostructures, hardness, and tensile properties were investigated. The fracture surfaces after tensile testing were also examined. The results showed that the pin geometry and travel speed are considered the most important controlling parameters in BT-FSW thick lap joints. The square (Sq) pin geometry gives the highest BT-FSW stir zone temperature compared to the other two pins, cylindrical (Cy) and triangular (Tr), whereas the Tr pin gives the lowest stir zone temperature at all applied travel speeds from 200 to 1000 mm/min. Furthermore, the temperature along the lap joints decreased with increasing the welding speed, and the maximum temperature of 380 °C was obtained at the lowest travel speed of 200 mm/min with applying Sq pin geometry. The temperature at the advancing side (AS) was higher than that at the retreating side (RS) by around 20 °C. Defect-free welds were produced using a bobbin tool with Cy and Sq pin geometries at all the travel welding speeds investigated. BT-FSW at a travel speed of 200 mm/min leads to the highest tensile shear properties, in the case of using the Sq pin. The hardness profiles showed a significant effect for both the tool pin geometry and the welding speed, whereas the width of the softened region is reduced dramatically with increasing the welding speed and using the triangular pin.
A Simple Soft Computing Structure for Modeling and Control
Authors: Redjimi Hemza , Tar József Kázmér
Published: August 2021

Using the interpolation/extrapolation skills of the core function of an iterative adaptive controller, a structurally simple single essential layer neural network-based topological structure is suggested with fast and explicit single-step teaching and data-retrieving abilities. Its operation does not assume massive parallelism, therefore it easily can be simulated by simple sequential program codes not needing sophisticated data synchronization mechanisms. It seems to be advantageous in approximate model-based common, robust, or adaptive controllers that can compensate for the effects of minor modeling imprecisions. In this structure a neuron can be in either a firing or a passive (i.e., producing zero output) state. In firing state its activation function realizes an abstract rotation that maps the desired kinematic data into the space of the necessary control forces. The activation function allows the use of a simple and fast incremental model modification for slowly varying dynamic models. Its operation is exemplified by numerical simulations for a van der Pol oscillator in free motion, and within a Computed Torque type control. To reveal the possibility for efficient model correction, a robust Variable Structure/Sliding Mode Controller is applied, too. The novel structure can be obtained by approximate experimental observations as e.g., the fuzzy models.
Application of Decomposable Semi-Regenerative Processes to the Study of k-out-of-n Systems
Authors: Rykov Vladimir , Ivanova Nika , Kozyrev Dmitry
Published: August 2021

This paper aimed to demonstrate the capabilities of decomposable semi-regenerative processes for the investigation of the k-out-of-n system. Proposed in 1955 by W. Smith, the regeneration idea has come a long way in terms of development and has found widespread applications. First, we briefly recall the history of the development of the regeneration idea and the main results of the theory of regenerative, semi-regenerative, and decomposable semi-regenerative processes. Then, the methods of the theory of decomposable semi-regenerative processes are used for the study of a k-out-of-n renewable system with exponentially distributed life and generally distributed repair times of its components. This system is very important for practice and its special cases have previously been considered (including by the authors); however, only special cases and using other methods are considered herein. In the current paper, two scenarios of system repair after its failure are considered for the first time: the partial and the full system repair scenarios. For both scenarios, the time-dependent system state probabilities are calculated in terms of their Laplace transforms. The closed form representation of the stationary probabilities for both scenarios are also presented. These latest results represent a new contribution to the study of this system.
Estimating the Highest Time-Step in Numerical Methods to Enhance the Optimization of Chaotic Oscillators
Authors: Valencia-Ponce  Martín Alejandro , Tlelo-Cuautle Esteban , de la Fraga Luis Gerardo
Published: August 2021

The execution time that takes to perform numerical simulation of a chaotic oscillator mainly depends on the time-step h. This paper shows that the optimization of chaotic oscillators can be enhanced by estimating the highest h in either one-step or multi-step methods. Four chaotic oscillators are used as a case study, and the optimization of their Kaplan-Yorke dimension (DKY) is performed by applying three metaheuristics, namely: particle swarm optimization (PSO), many optimizing liaison (MOL), and differential evolution (DE) algorithms. Three representative one-step and three multi-step methods are used to solve the four chaotic oscillators, for which the estimation of the highest h is obtained from their stability analysis. The optimization results show the effectiveness of using a high h value for the six numerical methods in reducing execution time while maximizing the positive Lyapunov exponent (LE+) and DKY of the chaotic oscillators by applying PSO, MOL, and DE algorithms.
Domain Heuristic Fusion of Multi-Word Embeddings for Nutrient Value Prediction
Authors: Ispirova Gordana , Eftimov Tome , Koroušić Seljak Barbara
Published: August 2021

Being both a poison and a cure for many lifestyle and non-communicable diseases, food is inscribing itself into the prime focus of precise medicine. The monitoring of few groups of nutrients is crucial for some patients, and methods for easing their calculations are emerging. Our proposed machine learning pipeline deals with nutrient prediction based on learned vector representations on short text–recipe names. In this study, we explored how the prediction results change when, instead of using the vector representations of the recipe description, we use the embeddings of the list of ingredients. The nutrient content of one food depends on its ingredients; therefore, the text of the ingredients contains more relevant information. We define a domain-specific heuristic for merging the embeddings of the ingredients, which combines the quantities of each ingredient in order to use them as features in machine learning models for nutrient prediction. The results from the experiments indicate that the prediction results improve when using the domain-specific heuristic. The prediction models for protein prediction were highly effective, with accuracies up to 97.98%. Implementing a domain-specific heuristic for combining multi-word embeddings yields better results than using conventional merging heuristics, with up to 60% more accuracy in some cases.
Multi-Output Soft Sensor with a Multivariate Filter That Predicts Errors Applied to an Industrial Reactive Distillation Process
Authors: Klimchenko Vladimir , Torgashov Andrei , Shardt Yuri A. W. , Yang Fan
Published: August 2021

The paper deals with the problem of developing a multi-output soft sensor for the industrial reactive distillation process of methyl tert-butyl ether production. Unlike the existing soft sensor approaches, this paper proposes using a soft sensor with filters to predict model errors, which are then taken into account as corrections in the final predictions of outputs. The decomposition of the problem of optimal estimation of time delays is proposed for each input of the soft sensor. Using the proposed approach to predict the concentrations of methyl sec-butyl ether, methanol, and the sum of dimers and trimers of isobutylene in the output product in a reactive distillation column was shown to improve the results by 32%, 67%, and 9.5%, respectively.
Green’s Function Related to a n-th Order Linear Differential Equation Coupled to Arbitrary Linear Non-Local Boundary Conditions
Authors: Cabada Alberto , López-Somoza Lucía , Yousfi Mouhcine
Published: August 2021

In this paper, we obtain the explicit expression of the Green’s function related to a general n-th order differential equation coupled to non-local linear boundary conditions. In such boundary conditions, an n dimensional parameter dependence is also assumed. Moreover, some comparison principles are obtained. The explicit expression depends on the value of the Green’s function related to the two-point homogeneous problem; that is, we are assuming that when all the parameters involved on the boundary conditions take the value zero then the problem has a unique solution, which is characterized by the corresponding Green’s function g. The expression of the Green’s function G of the general problem is given as a function of g and the real parameters considered at the boundary conditions. It is important to note that, in order to ensure the uniqueness of the solution of the considered linear problem, we must assume a non-resonant additional condition on the considered problem, which depends on the non-local conditions and the corresponding parameters. We point out that the assumption of the uniqueness of the solution of the two-point homogeneous problem is not a necessary condition to ensure the existence of the solution of the general case. Of course, in this situation, the expression we are looking for must be obtained in a different manner. To show the applicability of the obtained results, a particular example is given.