bluuebunny/crossref_metadata_2025 huggingface dataset:
Polysaccharides-Based Complex Particles’ Protective Role on the Stability and Bioactivity of Immobilized Curcumin
Authors: Iurciuc (Tincu) Camelia-Elena , Atanase Leonard Ionuţ , Jérôme Christine , Sol Vincent , Martin Patrick , Popa Marcel , Ochiuz Lăcrămioara
Published: March 2021

The curcumin degradation represents a significant limitation for its applications. The stability of free curcumin (FC) and immobilized curcumin in complex particles (ComPs) based on different polysaccharides was studied under the action of several factors. Ultraviolet-visible (UV-VIS) and Fourier-transform infrared (FTIR) spectroscopy proved the FC photodegradation and its role as a metal chelator: 82% of FC and between 26% and 39.79% of curcumin within the ComPs degraded after exposure for 28 days to natural light. The degradation half-life (t1/2) decreases for FC when the pH increases, from 6.8 h at pH = 3 to 2.1 h at pH = 9. For curcumin extracted from ComPs, t1/2 was constant (between 10 and 13 h) and depended on the sample’s composition. The total phenol (TPC) and total flavonoids (TFC) content values increased by 16% and 13%, respectively, for FC exposed to ultraviolet light at λ = 365 nm (UVA), whereas no significant change was observed for immobilized curcumin. Antioxidant activity expressed by IC50 (µmoles/mL) for FC exposed to UVA decreased by 29%, but curcumin within ComPs was not affected by the UVA. The bovine serum albumin (BSA) adsorption efficiency on the ComPs surface depends on the pH value and the cross-linking degree. ComPs have a protective role for the immobilized curcumin.
The Interplay between Immune System and Microbiota in Inflammatory Bowel Disease: A Narrative Review
Authors: Aldars-García Laila , Marin Alicia C. , Chaparro María , Gisbert Javier P.
Published: March 2021

The importance of the gut microbiota in human health is currently well established. It contributes to many vital functions such as development of the host immune system, digestion and metabolism, barrier against pathogens or brain–gut communication. Microbial colonization occurs during infancy in parallel with maturation of the host immune system; therefore, an adequate cross-talk between these processes is essential to generating tolerance to gut microbiota early in life, which is crucial to prevent allergic and immune-mediated diseases. Inflammatory bowel disease (IBD) is characterized by an exacerbated immune reaction against intestinal microbiota. Changes in abundance in the gut of certain microorganisms such as bacteria, fungi, viruses, and archaea have been associated with IBD. Microbes that are commonly found in high abundance in healthy gut microbiomes, such as F. prausnitzii or R. hominis, are reduced in IBD patients. E. coli, which is usually present in a healthy gut in very low concentrations, is increased in the gut of IBD patients. Microbial taxa influence the immune system, hence affecting the inflammatory status of the host. This review examines the IBD microbiome profile and presents IBD as a model of dysbiosis.
Accurate Receptor-Ligand Binding Free Energies from Fast QM Conformational Chemical Space Sampling
Authors: Boz Esra , Stein Matthias
Published: March 2021

Small molecule receptor-binding is dominated by weak, non-covalent interactions such as van-der-Waals hydrogen bonding or electrostatics. Calculating these non-covalent ligand-receptor interactions is a challenge to computational means in terms of accuracy and efficacy since the ligand may bind in a number of thermally accessible conformations. The conformational rotamer ensemble sampling tool (CREST) uses an iterative scheme to efficiently sample the conformational space and calculates energies using the semi-empirical ‘Geometry, Frequency, Noncovalent, eXtended Tight Binding’ (GFN2-xTB) method. This combined approach is applied to blind predictions of the modes and free energies of binding for a set of 10 drug molecule ligands to the cucurbit[n]urils CB[8] receptor from the recent ‘Statistical Assessment of the Modeling of Proteins and Ligands’ (SAMPL) challenge including morphine, hydromorphine, cocaine, fentanyl, and ketamine. For each system, the conformational space was sufficiently sampled for the free ligand and the ligand-receptor complexes using the quantum chemical Hamiltonian. A multitude of structures makes up the final conformer-rotamer ensemble, for which then free energies of binding are calculated. For those large and complex molecules, the results are in good agreement with experimental values with a mean error of 3 kcal/mol. The GFN2-xTB energies of binding are validated by advanced density functional theory calculations and found to be in good agreement. The efficacy of the automated QM sampling workflow allows the extension towards other complex molecular interaction scenarios.
A Novel Position-Specific Encoding Algorithm (SeqPose) of Nucleotide Sequences and Its Application for Detecting Enhancers
Authors: Mu Xuechen , Wang Yueying , Duan Meiyu , Liu Shuai , Li Fei , Wang Xiuli , Zhang Kai , Huang Lan , Zhou Fengfeng
Published: March 2021

Enhancers are short genomic regions exerting tissue-specific regulatory roles, usually for remote coding regions. Enhancers are observed in both prokaryotic and eukaryotic genomes, and their detections facilitate a better understanding of the transcriptional regulation mechanism. The accurate detection and transcriptional regulation strength evaluation of the enhancers remain a major bioinformatics challenge. Most of the current studies utilized the statistical features of short fixed-length nucleotide sequences. This study introduces the location information of each k-mer (SeqPose) into the encoding strategy of a DNA sequence and employs the attention mechanism in the two-layer bi-directional long-short term memory (BD-LSTM) model (spEnhancer) for the enhancer detection problem. The first layer of the delivered classifier discriminates between enhancers and non-enhancers, and the second layer evaluates the transcriptional regulation strength of the detected enhancer. The SeqPose-encoded features are selected by the Chi-squared test, and 45 positions are removed from further analysis. The existing studies may focus on selecting the statistical DNA sequence descriptors with large contributions to the prediction models. This study does not utilize these statistical DNA sequence descriptors. Then the word vector of the SeqPose-encoded features is obtained by using the word embedding layer. This study hypothesizes that different word vector features may contribute differently to the enhancer detection model, and assigns different weights to these word vectors through the attention mechanism in the BD-LSTM model. The previous study generously provided the training and independent test datasets, and the proposed spEnhancer is compared with the three existing state-of-the-art studies using the same experimental procedure. The leave-one-out validation data on the training dataset shows that the proposed spEnhancer achieves similar detection performances as the three existing studies. While spEnhancer achieves the best overall performance metric MCC for both of the two binary classification problems on the independent test dataset. The experimental data shows that the strategy of removing redundant positions (SeqPose) may help improve the DNA sequence-based prediction models. spEnhancer may serve well as a complementary model to the existing studies, especially for the novel query enhancers that are not included in the training dataset.
miRNA Regulatory Functions in Farm Animal Diseases, and Biomarker Potentials for Effective Therapies
Authors: Do Duy N. , Dudemaine Pier-Luc , Mathur Manisha , Suravajhala Prashanth , Zhao Xin , Ibeagha-Awemu Eveline M.
Published: March 2021

MicroRNAs (miRNAs) are small endogenous RNAs that regulate gene expression post-transcriptionally by targeting either the 3′ untranslated or coding regions of genes. They have been reported to play key roles in a wide range of biological processes. The recent remarkable developments of transcriptomics technologies, especially next-generation sequencing technologies and advanced bioinformatics tools, allow more in-depth exploration of messenger RNAs (mRNAs) and non-coding RNAs (ncRNAs), including miRNAs. These technologies have offered great opportunities for a deeper exploration of miRNA involvement in farm animal diseases, as well as livestock productivity and welfare. In this review, we provide an overview of the current knowledge of miRNA roles in major farm animal diseases with a particular focus on diseases of economic importance. In addition, we discuss the steps and future perspectives of using miRNAs as biomarkers and molecular therapy for livestock disease management as well as the challenges and opportunities for understanding the regulatory mechanisms of miRNAs related to disease pathogenesis.
Impaired Butyrate Induced Regulation of T Cell Surface Expression of CTLA-4 in Patients with Ulcerative Colitis
Authors: Magnusson Maria K. , Vidal Alexander , Maasfeh Lujain , Isaksson Stefan , Malhotra Rajneesh , Olsson Henric K. , Öhman Lena
Published: March 2021

Patients with ulcerative colitis (UC) have reduced intestinal levels of short-chain fatty acids (SCFAs), including butyrate, which are important regulators of host–microbiota crosstalk. The aim was therefore to determine effects of butyrate on blood and intestinal T cells from patients with active UC. T cells from UC patients and healthy subjects were polyclonally stimulated together with SCFAs and proliferation, activation, cytokine secretion, and surface expression of cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) were analyzed. Butyrate induced comparable, dose dependent inhibition of activation and proliferation in blood T cells and activation in intestinal T cells from UC patients and healthy subjects. However, surface expression of the inhibitory molecule CTLA-4 on stimulated blood and intestinal T cells was impaired in UC patients and was not restored following butyrate treatment. Furthermore, unlike intestinal T cells from healthy subjects, butyrate was unable to downregulate secretion of interferon gamma (IFNγ), interleukin (IL)-4, IL-17A, and IL-10 in UC patients. Although seemingly normal inhibitory effects on T cell activation and proliferation, butyrate has an impaired ability to reduce cytokine secretion and induce surface expression of CTLA-4 in T cells from UC patients with active disease. Overall, these observations indicate a dysfunction in butyrate induced immune regulation linked to CTLA-4 signaling in T cells from UC patients during a flare.
Molecular Action of Polyphenols in Leukaemia and Their Therapeutic Potential
Authors: Alaswad Hamza A. , Mahbub Amani A. , Le Maitre Christine L. , Jordan-Mahy Nicola
Published: March 2021

Leukaemia is a malignant disease of the blood. Current treatments for leukaemia are associated with serious side-effects. Plant-derived polyphenols have been identified as potent anti-cancer agents and have been shown to work synergistically with standard chemotherapy agents in leukaemia cell lines. Polyphenols have multiple mechanisms of action and have been reported to decrease cell proliferation, arrest cell cycle and induce apoptosis via the activation of caspase (3, 8 and 9); the loss of mitochondrial membrane potential and the release of cytochrome c. Polyphenols have been shown to suppress activation of transcription factors, including NF-kB and STAT3. Furthermore, polyphenols have pro-oxidant properties, with increasing evidence that polyphenols inhibit the antioxidant activity of glutathione, causing oxidative DNA damage. Polyphenols also induce autophagy-driven cancer cell death and regulate multidrug resistance proteins, and thus may be able to reverse resistance to chemotherapy agents. This review examines the molecular mechanism of action of polyphenols and discusses their potential therapeutic targets. Here, we discuss the pharmacological properties of polyphenols, including their anti-inflammatory, antioxidant, anti-proliferative, and anti-tumour activities, and suggest that polyphenols are potent natural agents that can be useful therapeutically; and discuss why data on bioavailability, toxicity and metabolism are essential to evaluate their clinical use.
The Marine Polysaccharide Ulvan Confers Potent Osteoinductive Capacity to PCL-Based Scaffolds for Bone Tissue Engineering Applications
Authors: Kikionis Stefanos , Ioannou Efstathia , Aggelidou Eleni , Tziveleka Leto-Aikaterini , Demiri Efterpi , Bakopoulou Athina , Zinelis Spiros , Kritis Aristeidis , Roussis Vassilios
Published: March 2021

Hybrid composites of synthetic and natural polymers represent materials of choice for bone tissue engineering. Ulvan, a biologically active marine sulfated polysaccharide, is attracting great interest in the development of novel biomedical scaffolds due to recent reports on its osteoinductive properties. Herein, a series of hybrid polycaprolactone scaffolds containing ulvan either alone or in blends with κ-carrageenan and chondroitin sulfate was prepared and characterized. The impact of the preparation methodology and the polysaccharide composition on their morphology, as well as on their mechanical, thermal, water uptake and porosity properties was determined, while their osteoinductive potential was investigated through the evaluation of cell adhesion, viability, and osteogenic differentiation of seeded human adipose-derived mesenchymal stem cells. The results verified the osteoinductive ability of ulvan, showing that its incorporation into the polycaprolactone matrix efficiently promoted cell attachment and viability, thus confirming its potential in the development of biomedical scaffolds for bone tissue regeneration applications.
Evaluating Consumers’ Willingness to Pay for Delay Compensation Services in Intra-City Delivery—A Value Optimization Study Using Choice
Authors: Pan Ruixu , Huang Yujie , Xiao Xiongwu
Published: March 2021

Intra-city delivery has developed rapidly along with the expansion of the logistics industry. Timely delivery is one of the main requirements of consumers and has become a major challenge to delivery service providers. To compensate for the adverse effects of delivery delays, platforms have launched delay compensation services for consumers who order. This study quantitatively evaluated consumer perception of the delay compensation service in intra-city deliveries using a choice experiment. We explored how different attributes of the delay compensation service plan affect consumer preference and their willingness to pay for the services. These service attributes are “delay probability display”, “compensation amount”, “compensation method”, “penalty method for riders”, and “one-time order price”. Using a multinomial logit model to analyze the questionnaire results, the respondents showed a positive preference for on-time delivery probability display, progressive compensation amount, and cash compensation. The results also show that the respondents opposed the penalty scheme where the riders would bear the compensation costs. Positive preference attributes are conducive to enhancing consumers’ willingness to order and pay for the program. Based on our findings and research conclusions, we proposed several recommendations to improve the delay compensation service program.
Spider Community Variability and Response to Restoration in Arid Grasslands of the Pacific Northwest, USA
Authors: Smith DiCarlo Lauren A. , DeBano Sandra J.
Published: March 2021

Grassland restoration in North America has intensified but its impact on major invertebrate groups, including spiders, is unclear. We studied three grassland locations in the Pacific Northwest, USA, to (1) describe variability in spider communities, (2) identify environmental variables that may underlie patterns in spider communities, and (3) determine whether spiders and environmental variables differ between actively (removal of disturbances, then plant with natives) vs. passively restored sites (removal of disturbance only). We found spider richness, diversity, and composition differed among the three locations but abundance did not. Sites with more litter and invasive grass cover had more spiders while sites at higher elevation and with more forb and biological soil crust cover had increased spider richness and diversity. Spider community composition was associated with elevation and litter cover. Surprisingly, no spider community or environmental variables differed between actively and passively restored sites, except that litter cover was higher in passively restored sites. This study demonstrates that even in superficially similar locations, invertebrate communities may differ greatly and these differences may prevent consistent responses to active vs. passive restoration. If increasing biodiversity or the abundance of invertebrate prey are goals, then environmental factors influencing spider communities should be taken into account in restoration planning.
Systematic Histological Scoring Reveals More Prominent Interstitial Inflammation in Myeloperoxidase-ANCA Compared to Proteinase 3-ANCA Glomerulonephritis
Authors: Hakroush Samy , Kluge Ingmar Alexander , Ströbel Philipp , Korsten Peter , Tampe Désirée , Tampe Björn
Published: March 2021

Background: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a systemic vasculitis, most frequently presenting as microscopic polyangiitis (MPA) or granulomatosis with polyangiitis (GPA). Kidney involvement is a common and severe complication of ANCA AAV which is observed in a considerable subset of patients, mainly affecting glomeruli. However, tubulointerstitial lesions have also been described in ANCA glomerulonephritis (GN). Therefore, we aim to describe active and chronic tubulointerstitial lesions in ANCA GN subtypes by systematic scoring analogous to the Banff scoring system while also utilizing clinical and laboratory findings. Methods: A total of 49 kidney biopsies with ANCA GN were retrospectively included in a single-center cohort study between 2015–2020. Results: We report that MPO-ANCA GN is associated with more severe deterioration of kidney function independent of systemic markers of AAV disease activity, and is also associated with increased proteinuria in MPO-ANCA GN and a decreased fraction of normal glomeruli. Finally, MPO-ANCA GN showed distinct, active, and chronic tubulointerstitial lesions. Conclusion: New insights into the pathophysiology of both entities, as well as differences in the clinical presentation of MPO- versus PR3-ANCA GN, could potentially pave the way for more precise treatment regimens. Therefore, it is important to understand the differences in histopathological presentation, especially in yet underestimated active tubulointerstitial lesions of ANCA GN subtypes. This research could further improve our understanding of distinct pathophysiological mechanisms.
Effect of Inpatient and Outpatient Pneumonia on Mobility Disability, Gait Speed, and Physical Activity in Older Adults
Authors: Brown Joshua , Sato Reiko , Morley John E.
Published: March 2021

Pathophysiological changes caused by pneumonia may influence physical functioning in older adults. This study was a secondary analysis of the Lifestyle Interventions and Independence for Elders (LIFE) Study. The LIFE Study included 1635 individuals over an average follow-up of 2.6 years at eight clinical sites during 2010–2013. Adults ≥70 years-old with mobility limitations (Short Physical Performance Battery score ≤9) were randomized to a physical activity (exercise) intervention or health education control arm. This analysis evaluated the association between pneumonia events and major mobility disability (MMD), gait speed, and physical activity levels. Pneumonia events, classified as inpatient or outpatient, were assessed by self-report during longitudinal follow-up. MMD was measured by the inability to complete a 400-m walk test, or other proxies, as a binary outcome and separately analyzed as “short-term” and “long-term” MMD. Short-term MMD was defined as MMD occurring in the assessment period immediately following (between 1-day to 6-months after) a pneumonia event and long-term was in the following assessment period (6 to 12 months after the event). Short- and long-term gait speed was similarly recorded during the walk test in meters per second (m/s) and measured on a linear scale. Physical activity levels were captured via accelerometry and shown visually. Mixed-effects repeated measures regression adjusted for intervention assignment, baseline demographics, comorbid conditions, and frailty. Among the 1635 participants, n = 174 (10.7%) had a pneumonia event of which 80 (46% of events) were hospitalized. Those with pneumonia during follow-up had higher baseline medication use, prior hospitalizations, and higher prevalence of lung disorders but similar baseline functioning. Pneumonia hospitalization was associated with a 4-fold increase [OR = 4.1 (3.2–5.0)] and outpatient events were associated with a 2-fold increase [OR = 2.6 (2.1–3.1)] in the odds of short-term MMD. Pneumonia hospitalizations, but not outpatient events, were associated with a nearly 10% decrement in short-term gait speed. Pneumonia events were not associated with either long-term MMD or gait speed outcomes. Physical activity levels decreased from baseline immediately following the pneumonia episode (10–30% reductions) and returned to baseline after 6 months. These results emphasize the importance of managing pneumonia risk factors to prevent disease in order to maintain physical independence and activity in older adults.
NEURAP—A Dedicated Neutron-Imaging Facility for Highly Radioactive Samples
Authors: Lehmann Eberhard , Thomsen Knud , Strobl Markus , Trtik Pavel , Bertsch Johannes , Dai Yong
Published: March 2021

NEURAP is a dedicated set-up at the Swiss neutron spallation source (SINQ) at the Paul Scherrer Institut (PSI), optionally implemented as a special configuration of the neutron-imaging station NEUTRA. It is one of very few instrumentations available worldwide enabling neutron-imaging of highly radioactive samples to be performed routinely, with special precautions and following a specific procedure. Since the relevant objects are strong γ-sources, dedicated techniques are needed to handle the samples and to perform neutron-imaging despite the radiation background. Dysprosium (Dy)-loaded imaging plates, effectively made sensitive to neutrons only, are employed. Neutrons are captured by Dy during neutron irradiation. Then the imaging plate is erased removing gamma detections. A subsequent relatively long self-exposure by the radiation from the intrinsic neutron-activated Dy within the imaging plate yields the neutron-only radiograph that is finally read out. During more than 20 years of NEURAP operation, images have been obtained for two major applications: (a) highly radioactive SINQ target components were investigated after long-term operation life; and (b) spent fuel rods and their cladding from Swiss nuclear power plants were characterized. Quantitative analysis of the image data demonstrated the accumulation of spallation products in the lead filled “Cannelloni” Zircaloy tubes of the SINQ target and the aggregation of hydrogen at specific sites in used fuel pins of power plants and their cladding, respectively. These results continue to help understanding material degradation and optimizing the operational regimes, which might lead to extending the safe lifetimes of these components.
COVID-19-Related Social Media Fake News in India
Authors: Al-Zaman Md. Sayeed
Published: March 2021

COVID-19-related online fake news poses a threat to Indian public health. In response, this study seeks to understand the five important features of COVID-19-related social media fake news by analyzing 125 Indian fake news. The analysis produces five major findings based on five research questions. First, the seven themes of fake news are health, religiopolitical, political, crime, entertainment, religious, and miscellaneous. Health-related fake news (67.2%) is on the top of the list that includes medicine, medical and healthcare facilities, viral infection, and doctor-patient issues. Second, the seven types of fake news contents are text, photo, audio, video, text and photo, text and video, and text and photo and video. More fake news takes the form of text and video (47.2%). Third, online media produces more fake news (94.4%) than mainstream media (5.6%). More interestingly, four social media platforms: Twitter, Facebook, WhatsApp, and YouTube, produce most of the fake news. Fourth, relatively more fake news has international connections (54.4%) as the COVID-19 pandemic is a global phenomenon. Fifth, most of the COVID-19-related fake news is negative (63.2%) which could be a real threat to public health. These results may contribute to the academic understanding of social media fake news during the present and future health-crisis period. This paper concludes by stating some limitations regarding the data source and results, as well as provides a few suggestions for further research.
Differentiating Neuroblastoma: A Systematic Review of the Retinoic Acid, Its Derivatives, and Synergistic Interactions
Authors: Bayeva Nadiya , Coll Erin , Piskareva Olga
Published: March 2021

A neuroblastoma (NB) is a solid paediatric tumour arising from undifferentiated neuronal cells. Despite the recent advances in disease management and treatment, it remains one of the leading causes of childhood cancer deaths, thereby necessitating the development of new therapeutic agents and regimens. Retinoic acid (RA), a vitamin A derivative, is a promising agent that can induce differentiation in NB cells. Its isoform, 13-cis RA or isotretinoin, is used in NB therapy; however, its effectiveness is limited to treating a minimal residual disease as maintenance therapy. As such, research focuses on RA derivatives that might increase the anti-NB action or explores the potential synergy between RA and other classes of drugs, such as cellular processes mediators, epigenetic modifiers, and immune modulators. This review summarises the in vitro, in vivo, and clinical data of RA, its derivatives, and synergising compounds, thereby establishing the most promising RA derivatives and combinations of RA for further investigation.
Exploring the Global Research Trends of Land Use Planning Based on a Bibliometric Analysis: Current Status and Future Prospects
Authors: Lv Tiangui , Wang Li , Xie Hualin , Zhang Xinmin , Zhang Yanwei
Published: March 2021

The land topic has generally become a major socioeconomic issue that currently attracts attention globally. To explore the issue, various countries devote much attention to land use planning. This paper searches the Core Collection of the Web of Science and collects 1771 land use planning articles published between 1990 and 2019. The R software, biblioshiny package, and CiteSpace are applied in this paper. The results show the following: (1) the number of papers related to land use planning has shown an overall growth trend, which can be divided into the following four stages: initial exploration, preliminary growth, stable development, and rapid development; (2) the United States is in an absolute leading position as the primary research force among developed countries. The top 3 countries related to international cooperation are the United States, China, and Italy; (3) land use planning, land use, GIS, urban planning, China, spatial planning and climate change are some high-frequency keywords used in land use planning; (4) the current research hot spots mainly focus on the relationship between land use spatial planning and regional planning, land informatization development, public participation, urban sprawl, and sustainable development; (5) the themes show 8 evolutionary paths related to the following four topics: ecosystem protection, climate and natural change, urban sprawl and agricultural development, and GIS development; (6) this paper proposes that strengthening integration within disciplines, introducing new theories and methods, and sustainable land use will become future research directions requiring more land use planning attention.
Comparative Analysis of Static and Viscoelastic Mechanical Behavior of Different Luting Material Categories after Aging
Authors: Ilie Nicoleta
Published: March 2021

The longevity of indirect restorations is primarily determined by the appropriate selection of the luting material. The function of a luting material is to seal the restoration and hold it in place for the time required for service. The mechanical behavior of luting materials and in particular their aging behavior, therefore, play a decisive role. The study provides a comparative analysis of the static and dynamic mechanical behavior of the most commonly used luting material categories—zinc phosphate cement, glass–ionomer cement, resin-modified glass–ionomer cement, resin-based composites, and self-adhesive resin-based composites—and their aging behavior. It also takes into account that luting materials are viscoelastic materials, i.e., materials that respond to external loading in a way that lies between an elastic solid and a viscous liquid. Flexural strength and modulus were determined in a three-point bending test followed by fractography analysis. The quasi-static and viscoelastic behavior was analyzed by a depth-sensing indentation test provided with a dynamic mechanical analysis (DMA) module at 20 different frequencies (1–50 Hz). The fracture toughness was evaluated in a notchless triangular prism (NTP) test. Material type exhibits the strongest influence on all measured properties, while the effect of aging becomes more evident in the material reliability. The variation of the viscoelastic parameters with aging reflects cement maturation or polymer plasticization.
A Microstructural Investigation of Austenitic Heat Resistant Alloy after 500 h of Steam Oxidation
Authors: Rutkowski Bogdan , Baran Krzysztof , Błoniarz Remigiusz , Kozieł Tomasz
Published: March 2021

Alloy 709 was oxidized at 700 °C for 500 h in a steam environment. A microstructural analysis of the oxide scale is reported. Modern techniques of advanced electron microscopy were used to characterize the morphology of the oxide scale and recognize its single components. The material developed a complex, multilayered oxide scale. The outermost layer consisting of Fe2O3. Fe2NiO4 tI28 spinel was detected underneath. An internal oxidation zone is present in the innermost layer. High quality SEM-EDS maps give insight into a larger area of the oxide scale at a relatively low magnification.
Effect of Peak Current Density on Tensile Properties of AZ31B Magnesium Alloy
Authors: Indhiarto Ichsan , Shimizu Tetsuhide , Yang Ming
Published: March 2021

An investigation into the effects, including the athermal effect, of a pulsed current on AZ31B magnesium alloy was carried out. Different peak current densities were applied at the same temperature under uniaxial tensile testing. The results indicate that the stress reduction caused by the increasing peak current density is independent of temperature. The strain hardening coefficient also shows a similar trend. The fracture strain shows the optimum value due to the current crowding effect.
Bone Coverage around Hydroxyapatite/Poly(L-Lactide) Composite Is Determined According to Depth from Cortical Bone Surface in Rabbits
Authors: Morizane Kazuaki , Goto Koji , Kawai Toshiyuki , Fujibayashi Shunsuke , Otsuki Bungo , Shimizu Takayoshi , Matsuda Shuichi
Published: March 2021

Composites of unsintered hydroxyapatite (HA) and poly(L-lactide) (PLLA) reinforced by compression forging are biodegradable, bioactive, and have ultrahigh strength. However, foreign body reactions to PLLA and physical irritation can occur when not covered by bone. We aimed to confirm the relationships between the depth of the implanted HA-PLLA threaded pins and the new bone formation. We inserted HA-PLLA composite threaded pins (diameter: 2.0 or 4.5 mm) into the femoral and tibial bones of 32 mature male Japanese white rabbits (weight 3.0–3.5 kg) with the pin head 1 or 0 mm below or protruding 1 or 2 mm above surrounding cortical bone. Eight euthanized rabbits were radiologically and histologically assessed at various intervals after implantation. Bone bridging was complete over pins of both diameters at ~12 weeks, when inserted 1 mm below the surface, but the coverage of the pins inserted at 0 mm varied. Bone was not formed when the pins protruded >1 mm from the bone surface. No inflammation developed around the pins by 25 weeks. However, foreign body reactions might develop if composites are fixed above the bone surface, and intraosseous fixation would be desirable using double-threaded screws or a countersink to avoid screw head protrusion.
Growth of ZnO Nanorods on ITO Film for Piezoelectric Nanogenerators
Authors: Kim Hyun Gi , Kim Eun Hye , Kim Sung Soo
Published: March 2021

Piezoelectric nanogenerators (NGs) consist of zinc oxide nanorods (ZNRs), and polydimethylsiloxane (PDMS) layers were fabricated on indium tin oxide (ITO)-coated substrate for the energy harvesting system. The formation of seed layers by an optimized aqueous solution method greatly helped the growth of well-aligned ZNRs for NGs. Polyethylenimine (PEI) was added to increase the aspect ratio of ZNRs, which reached up to 24:1, showing the best energy harvesting performance of NGs. The formation of PDMS layers on the ZNRs increased the work function difference for the top Ag electrode. The thickness of PDMS layers was optimized as 80 μm, which showed the maximum work function difference, resulting in the enhancement of charge density. Piezoelectric NGs made of ZNRs of the highest aspect ratio of 24:1 with an 80-μm-thick PDMS layer achieved the highest current density of 2270.1 nA/cm2, which could be sufficient to drive low-power electronics.
Clindamycin-Based 3D-Printed and Electrospun Coatings for Treatment of Implant-Related Infections
Authors: Maver Tina , Mastnak Tinkara , Mihelič Mihela , Maver Uroš , Finšgar Matjaž
Published: March 2021

This study presents the development and characterisation of two novel bioactive coatings deposited on TiAlV and AISI 316LVM substrates. The coatings were prepared using 3D printing and electrospinning. The 3D-printed coating consisted of the cellulose nanofibril suspension, alginate, and carboxymethylcellulose (CMC), while CMC and polyethylene oxide were used to prepare the electrospun coating. Both coatings were loaded with the antibiotic clindamycin (CLIN), which is a bacteriostatic lincosamide known for its activity against streptococci, staphylococci, pneumococci, Bacteroides species, and other anaerobes. Initial characterisation of the coatings was performed by attenuated total reflectance Fourier transform infrared spectroscopy, field emission scanning electron microscopy, and atomic force microscopy. Furthermore, the contact angle measurements, swelling rate, and biodegradability of the coatings were investigated. The released concentration of CLIN in PBS (pH = 7.4 at 25 °C) was determined by UV-VIS spectrophotometry. The coatings’ biocompatibility was determined using an MTT (3(4,5 dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) assay using an osteoblast cell culture (hFOB 1.19, ATCC CRL 11372).
First-Principle and Atomistic Modelling in Materials Science
Authors: Posselt Matthias
Published: March 2021

In the last two decades, the importance of Computational Materials Science has continuously increased due to the steadily growing availability of computer power [...]
Exploring the Slow Magnetic Relaxation of a Family of Photoluminescent 3D Lanthanide–Organic Frameworks Based on Dicarboxylate Ligands
Authors: Oyarzabal Itziar , Rojas Sara , Parejo Ana D. , Salinas-Castillo Alfonso , García José Ángel , Seco José M. , Cepeda Javier , Rodríguez-Diéguez Antonio
Published: March 2021

A family of metal–organic frameworks with general formula {[Nd2(ant)2((NH2)2-bdc)(DMF)4]·2DMF}n (1) and {[Ln2(ant)2((NH2)2-bdc)(DMF)4]·2DMF·2H2O}n (Ln = Tb (2), Ho (3), and Er (4)) has been obtained from reactions between 9,10-anthracenedicarboxylic (H2ant) and 2,5-diaminoterephthalic ((NH2)2-H2bdc) acids, and lanthanide ions in dimethylformamide (DMF). These lanthanide–organic frameworks (LnOFs) have been characterized, and their crystal structures have been elucidated by single crystal and powder X-ray diffraction methods (on the basis of a comparative refinement with similar structures), respectively for 1 and 2–4. All LnOFs present three-dimensional structures composed of dinuclear [Ln2(µ-CO2)4] entities linked through both carboxylate ligands that yield open frameworks in which DMF and water molecules are located in the channels. Magnetic studies of these LnOFs have revealed slow relaxation of the magnetization for the Nd-based counterpart. The compounds also acknowledge relevant photoluminescence (PL) emissions in the visible (for the Tb-based homologue) and near-infrared (for the Nd- and Er-based compounds) regions. The strong green emission yielded by compound 2 at room temperature allows its study for photoluminescence (PL) sensing of various solvent molecules, finding a particular discrimination for acetone.
Mathematical and Statistical Analysis of Doubling Times to Investigate the Early Spread of Epidemics: Application to the COVID-19 Pandemic
Authors: Smirnova Alexandra , DeCamp Linda , Chowell Gerardo
Published: March 2021

Simple mathematical tools are needed to quantify the threat posed by emerging and re-emerging infectious disease outbreaks using minimal data capturing the outbreak trajectory. Here we use mathematical analysis, simulation and COVID-19 epidemic data to demonstrate a novel approach to numerically and mathematically characterize the rate at which the doubling time of an epidemic is changing over time. For this purpose, we analyze the dynamics of epidemic doubling times during the initial epidemic stage, defined as the sequence of times at which the cumulative incidence doubles. We introduce new methodology to characterize epidemic threats by analyzing the evolution of epidemics as a function of (1) the number of times the epidemic doubles until the epidemic peak is reached and (2) the rate at which the doubling times increase. In our doubling-time approach, the most dangerous epidemic threats double in size many times and the doubling times change at a relatively low rate (e.g., doubling times remain nearly invariant) whereas the least transmissible threats double in size only a few times and the doubling times rapidly increases in the period of emergence. We derive analytical formulas and test and illustrate our methodology using synthetic and COVID-19 epidemic data. Our mathematical analysis demonstrates that the series of epidemic doubling times increase approximately according to an exponential function with a rate that quantifies the rate of change of the doubling times. Our analytic results are in excellent agreement with numerical results. Our methodology offers a simple and intuitive approach that relies on minimal outbreak trajectory data to characterize the threat posed by emerging and re-emerging infectious diseases.
Effects of Damaged Rotor Blades on the Aerodynamic Behavior and Heat-Transfer Characteristics of High-Pressure Gas Turbines
Authors: Mai Thanh Dam , Ryu Jaiyoung
Published: March 2021

Gas turbines are critical components of combined-cycle power plants because they influence the power output and overall efficiency. However, gas-turbine blades are susceptible to damage when operated under high-pressure, high-temperature conditions. This reduces gas-turbine performance and increases the probability of power-plant failure. This study compares the effects of rotor-blade damage at different locations on their aerodynamic behavior and heat-transfer properties. To this end, we considered five cases: a reference case involving a normal rotor blade and one case each of damage occurring on the pressure and suction sides of the blades’ near-tip and midspan sections. We used the Reynolds-averaged Navier-Stokes equation coupled with the k − ω SST γ turbulence model to solve the problem of high-speed, high-pressure compressible flow through the GE-E3 gas-turbine model. The results reveal that the rotor-blade damage increases the heat-transfer coefficients of the blade and vane surfaces by approximately 1% and 0.5%, respectively. This, in turn, increases their thermal stresses, especially near the rotor-blade tip and around damaged locations. The four damaged-blade cases reveal an increase in the aerodynamic force acting on the blade/vane surfaces. This increases the mechanical stress on and reduces the fatigue life of the blade/vane components.
E-Commerce Supply Chain Models under Altruistic Preference
Authors: Wang Yuyan , Yu Zhaoqing , Shen Liang , Dong Wenquan
Published: March 2021

This paper reviews the decisions, coordination contract, and altruistic preference of an e-commerce supply chain (eSC) composed of a manufacturer and a third-party e-commerce platform (platform). The research derives optimal decisions in a decentralized model with altruistic preference; it is indicated that altruistic preference can help increase the sales price and sales service level. Although the platform’s altruistic preference is not beneficial to its own profits, it can help increase the manufacturer’s profits. Moreover, when the degree of altruistic preference is kept within a limit, the profit of the decentralized system is higher in a model with altruistic preferences, which indicates that altruistic preference can contribute toward maintaining a friendly, harmonious, and cooperative a relationship between the platform and manufacturers. Contrary to a traditional offline supply chain, where the sales price is the lowest in the centralized model, the sales price is highest in a centralized eSC model. In the proposed coordination contract, the platform with a certain degree of altruistic preference offers zero-commission sales service and charges a certain amount for a fixed professional service fee. The proposed contract is more applicable to products whose market demands are less affected by sales prices and more affected by the sales service level.
Branch Less, Cut More and Schedule Jobs with Release and Delivery Times on Uniform Machines
Authors: Vakhania Nodari , Werner Frank
Published: March 2021

We consider the problem of scheduling n jobs with identical processing times and given release as well as delivery times on m uniform machines. The goal is to minimize the makespan, i.e., the maximum full completion time of any job. This problem is well-known to have an open complexity status even if the number of jobs is fixed. We present a polynomial-time algorithm for the problem which is based on the earlier introduced algorithmic framework blesscmore (“branch less and cut more”). We extend the analysis of the so-called behavior alternatives developed earlier for the version of the problem with identical parallel machines and show how the earlier used technique for identical machines can be extended to the uniform machine environment if a special condition on the job parameters is imposed. The time complexity of the proposed algorithm is O(γm2nlogn), where γ can be either n or the maximum job delivery time qmax. This complexity can even be reduced further by using a smaller number κ<n in the estimation describing the number of jobs of particular types. However, this number κ becomes only known when the algorithm has terminated.
Empowering Advanced Driver-Assistance Systems from Topological Data Analysis
Authors: Frahi Tarek , Chinesta Francisco , Falcó Antonio , Badias Alberto , Cueto Elias , Choi Hyung Yun , Han Manyong , Duval Jean-Louis
Published: March 2021

We are interested in evaluating the state of drivers to determine whether they are attentive to the road or not by using motion sensor data collected from car driving experiments. That is, our goal is to design a predictive model that can estimate the state of drivers given the data collected from motion sensors. For that purpose, we leverage recent developments in topological data analysis (TDA) to analyze and transform the data coming from sensor time series and build a machine learning model based on the topological features extracted with the TDA. We provide some experiments showing that our model proves to be accurate in the identification of the state of the user, predicting whether they are relaxed or tense.
Bioactive Indole Diketopiperazine Alkaloids from the Marine Endophytic Fungus Aspergillus sp. YJ191021
Authors: Yang Jin , Gong Lizhi , Guo Miaomiao , Jiang Yu , Ding Yi , Wang Zhijie , Xin Xiujuan , An Faliang
Published: March 2021

Six new prenylated indole diketopiperazine alkaloids, asperthrins A–F (1–6), along with eight known analogues (7–14), were isolated from the marine-derived endophytic fungus Aspergillus sp. YJ191021. Their planar structures and absolute configurations were elucidated by HR-ESI-MS, 1D/2D NMR data, and time-dependent density functional theory (TDDFT)/ECD calculation. The isolated compounds were assayed for their inhibition against three agricultural pathogenic fungi, four fish pathogenic bacteria, and two agricultural pathogenic bacteria. Compound 1 exhibited moderate antifungal and antibacterial activities against Vibrioanguillarum, Xanthomonas oryzae pv. Oryzicola, and Rhizoctoniasolani with minimal inhibitory concentration (MIC) values of 8, 12.5, and 25 μg/mL, respectively. Furthermore, 1 displayed notable anti-inflammatory activity with IC50 value of 1.46 ± 0.21 μM in Propionibacteriumacnes induced human monocyte cell line (THP-1).
Somatic Comorbidities and Cardiovascular Safety in Ketamine Use for Treatment-Resistant Depression
Authors: Szarmach Joanna , Cubała Wiesław Jerzy , Włodarczyk Adam , Gałuszko-Węgielnik Maria
Published: March 2021

Background and Objectives: There is evidence for ketamine efficacy in treatment-resistant depression (TRD). Several safety and tolerability concerns arise that some psychotropic agents may provide blood pressure or/and heart rate alterations. The aim of this study is to review blood pressure measurements in course of the treatment with ketamine on treatment refractory inpatients with somatic comorbidities in the course of MDD and BP. Materials and Methods: The study population of 49 patients comprised MDD and BP subjects treated with ketamine registered in the naturalistic observational protocol of treatment-resistant mood disorders (NCT04226963). Results: The conducted analysis showed that among people suffering from hypertension there is a higher increase in systolic blood pressure (RR) after infusion 2 (p = 0.004) than among people who do not suffer from hypertension. Patients with hypertension have a higher increase in diastolic RR compared to those not suffering from hypertension (p = 0,038). Among the subjects with diabetes mellitus, significant differences occurred for infusions 2 (p = 0.020), 7 (p = 0.020), and 8 (p = 0.035) for heart rate (HR), compared to subjects without diabetes mellitus. A higher increase in diastolic RR was noted in the group of subjects suffering from diabetes mellitus (p = 0.010) compared to those who did not. In the hyperlipidemic patients studied, a significantly greater decrease in HR after infusion 5 (p = 0.031) and systolic RR after infusion 4 (p = 0.036) was noted compared to nonpatients. People after a stroke had significantly higher increases in diastolic RR after infusions 4 (p = 0.021) and 6 (p = 0.001) than those who did not have a stroke. Patients suffering from epilepsy had a significantly greater decrease in systolic RR after the 8th infusion (p = 0.017) compared to those without epilepsy. Limitations: The study may be underpowered due to the small sample size. The observations apply to inhomogeneous TRD population in a single-site with no blinding and are limited to the acute administration. Conclusions: This study supports evidence for good safety and tolerability profile for short-term IV ketamine use in TRD treatment. However, risk mitigation measures are to be considered in patients with metabolic and cardiovascular comorbidities.