bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiplex Real-Time PCR Assay for Six Major Carbapenemase Genes
Authors: Yoshioka Nori , Hagiya Hideharu , Deguchi Matsuo , Hamaguchi Shigeto , Kagita Masanori , Nishi Isao , Akeda Yukihiro , Tomono Kazunori
Published: March 2021

The global dissemination of carbapenemase-producing Enterobacteriaceae (CPE) is a major concern in public health. Due to the existence of the diversity of carbapenemases, development of an easily available, cost-effective multiplex detection assay for CPE is required worldwide. Using clinically available and reliable equipment, COBAS® z480 (Roche Diagnostics K.K., Tokyo, Japan), we developed a multiplex real-time PCR assay for the detection of two combinations of carbapenemases; first, blaNDM, blaKPC, and blaIMP (Set 1), and second, blaGES, blaOXA-48, and blaVIM (Set 2). We constructed standard curves for each carbapenemase gene using serial dilutions of DNA standards, then applied reference or clinical isolates with each carbapenemase gene to this assay. The multiplex assay showed satisfactory accuracy to detect CPE genes, with the correlation coefficients of greater than 0.99 for all genotypes. The assay appropriately differentiated the reference or clinical strains harboring each carbapenemase gene without cross reactivity. Lastly, the assay successfully detected multiple genes without false-positive reactions by applying six clinical isolates carrying both NDM and OXA-48-like carbapenemase genes. Major advantages of our assay include multiplicity, simple operation, robustness, and speed (1 h). We believe that the multiplex assay potentially contributes to early diagnosis of CPE with a diverse genetic background.
TIGIT/CD226 Axis Regulates Anti-Tumor Immunity
Authors: Yeo Jinah , Ko Minkyung , Lee Dong-Hee , Park Yoon , Jin Hyung-seung
Published: March 2021

Tumors escape immune surveillance by inducing various immunosuppressive pathways, including the activation of inhibitory receptors on tumor-infiltrating T cells. While monoclonal antibodies (mAbs) blocking programmed cell death 1 (PD-1), programmed death-ligand 1 (PD-L1), and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) have been approved for multiple cancer indications, only a subset of patients benefit from immune checkpoint blockade therapies, highlighting the need for additional approaches. Therefore, the identification of new target molecules acting in distinct or complementary pathways in monotherapy or combination therapy with PD-1/PD-L1 blockade is gaining immense interest. T cell immunoreceptor with Ig and immunoreceptor tyrosine-based inhibitory motif (ITIM) domains (TIGIT) has received considerable attention in cancer immunotherapy. Recently, anti-TIGIT mAb (tiragolumab) has demonstrated promising clinical efficacy in non-small cell lung cancer treatment when combined with an anti-PD-L1 drug (Tecentriq), leading to phase III trial initiation. TIGIT is expressed mainly on T and natural killer cells; it functions as an inhibitory checkpoint receptor, thereby limiting adaptive and innate immunity. CD226 competes for binding with the same ligands with TIGIT but delivers a positive stimulatory signal to the immune cells. This review discusses the recent discoveries regarding the roles of TIGIT and CD226 in immune cell function and their potential application in cancer immunotherapy.
Retrospective Evaluation of Progenitor Biological Bandage Use: A Complementary and Safe Therapeutic Management Option for Prevention of Hypertrophic Scarring in Pediatric Burn Care
Authors: Al-Dourobi Karim , Laurent Alexis , Deghayli Lina , Flahaut Marjorie , Abdel-Sayed Philippe , Scaletta Corinne , Michetti Murielle , Waselle Laurent , Simon Jeanne-Pascale , El Ezzi Oumama , Raffoul Wassim , Applegate Lee , Hirt-Burri Nathalie , Roessingh Anthony
Published: March 2021

Progenitor Biological Bandages (PBB) have been continuously applied clinically in the Lausanne Burn Center for over two decades. Vast translational experience and hindsight have been gathered, specifically for cutaneous healing promotion of donor-site grafts and second-degree pediatric burns. PBBs constitute combined Advanced Therapy Medicinal Products, containing viable cultured allogeneic fetal dermal progenitor fibroblasts. Such constructs may partly favor repair and regeneration of functional cutaneous tissues by releasing cytokines and growth factors, potentially negating the need for subsequent skin grafting, while reducing the formation of hypertrophic scar tissues. This retrospective case-control study (2010–2018) of pediatric second-degree burn patients comprehensively compared two initial wound treatment options (i.e., PBBs versus Aquacel® Ag, applied during ten to twelve days post-trauma). Results confirmed clinical safety of PBBs with regard to morbidity, mortality, and overall complications. No difference was detected between groups for length of hospitalization or initial relative burn surface decreasing rates. Nevertheless, a trend was observed in younger patients treated with PBBs, requiring fewer corrective interventions or subsequent skin grafting. Importantly, significant improvements were observed in the PBB group regarding hypertrophic scarring (i.e., reduced number of scar complications and related corrective interventions). Such results establish evidence of clinical benefits yielded by the Swiss fetal progenitor cell transplantation program and favor further implementation of specific cell therapies in highly specialized regenerative medicine.
In Silico Plasma Protein Binding Studies of Selected Group of Drugs Using TLC and HPLC Retention Data
Authors: Wanat Karolina , Żydek Grażyna , Hekner Adam , Brzezińska Elżbieta
Published: March 2021

Plasma protein binding is an important determinant of the pharmacokinetic properties of chemical compounds in living organisms. The aim of the present study was to determine the index of protein binding affinity based on chromatographic experiments. The question is which chromatographic environment will best mimic the drug–protein binding conditions. Retention data from normal phase thin-layer liquid chromatography (NP TLC), reversed phase (RP) TLC and HPLC chromatography experiments with 129 active pharmaceutical ingredients (APIs) were collected. The stationary phase of the TLC plates was modified with protein and the HPLC column was filled with immobilized human serum albumin. In both chromatographic methods, the mobile phase was based on a buffer with a pH of 7.4 to mimic physiological conditions. Chemometric analyses were performed to compare multiple linear regression models (MLRs) with retention data, using protein binding values as the dependent variable. In the course of the analysis, APIs were divided into acidic, basic and neutral groups, and separate models were created for each group. The MLR models had a coefficient of determination between 0.73 and 0.91, with the highest values from NP TLC data.
Discovery and Optimization of Selective Inhibitors of Meprin α (Part I)
Authors: Hou Shurong , Diez Juan , Wang Chao , Becker-Pauly Christoph , Fields Gregg B. , Bannister Thomas , Spicer Timothy P. , Scampavia Louis D. , Minond Dmitriy
Published: March 2021

Meprin α and β are zinc-dependent proteinases implicated in multiple diseases including cancers, fibrosis, and Alzheimer’s. However, until recently, only a few inhibitors of either meprin were reported and no inhibitors are in preclinical development. Moreover, inhibitors of other metzincins developed in previous years are not effective in inhibiting meprins suggesting the need for de novo discovery effort. To address the paucity of tractable meprin inhibitors we developed ultrahigh-throughput assays and conducted parallel screening of >650,000 compounds against each meprin. As a result of this effort, we identified five selective meprin α hits belonging to three different chemotypes (triazole-hydroxyacetamides, sulfonamide-hydroxypropanamides, and phenoxy-hydroxyacetamides). These hits demonstrated a nanomolar to micromolar inhibitory activity against meprin α with low cytotoxicity and >30-fold selectivity against meprin β and other related metzincincs. These selective inhibitors of meprin α provide a good starting point for further optimization.
Endothelial Iron Homeostasis Regulates Blood-Brain Barrier Integrity via the HIF2α—Ve-Cadherin Pathway
Authors: Rand Daniel , Ravid Orly , Atrakchi Dana , Israelov Hila , Bresler Yael , Shemesh Chen , Omesi Liora , Liraz-Zaltsman Sigal , Gosselet Fabien , Maskrey Taber S. , Schnaider Beeri Michal , Wipf Peter , Cooper Itzik
Published: March 2021

The objective of this study was to investigate the molecular response to damage at the blood-brain barrier (BBB) and to elucidate critical pathways that might lead to effective treatment in central nervous system (CNS) pathologies in which the BBB is compromised. We have used a human, stem-cell derived in-vitro BBB injury model to gain a better understanding of the mechanisms controlling BBB integrity. Chemical injury induced by exposure to an organophosphate resulted in rapid lipid peroxidation, initiating a ferroptosis-like process. Additionally, mitochondrial ROS formation (MRF) and increase in mitochondrial membrane permeability were induced, leading to apoptotic cell death. Yet, these processes did not directly result in damage to barrier functionality, since blocking them did not reverse the increased permeability. We found that the iron chelator, Desferal© significantly decreased MRF and apoptosis subsequent to barrier insult, while also rescuing barrier integrity by inhibiting the labile iron pool increase, inducing HIF2α expression and preventing the degradation of Ve-cadherin specifically on the endothelial cell surface. Moreover, the novel nitroxide JP4-039 significantly rescued both injury-induced endothelium cell toxicity and barrier functionality. Elucidating a regulatory pathway that maintains BBB integrity illuminates a potential therapeutic approach to protect the BBB degradation that is evident in many neurological diseases.
Multi-Component Hydrogel Beads Incorporated with Reduced Graphene Oxide for pH-Responsive and Controlled Co-Delivery of Multiple Agents
Authors: Obireddy Sreekanth Reddy , Lai Wing-Fu
Published: March 2021

The development of combination therapy has received great attention in recent years because of its potential to achieve higher therapeutic efficacy than that achieved by mono-drug therapy. Carriers for effective and stimuli-responsive co-delivery of multiple agents, however, are highly deficient at the moment. To address this need, this study reports the generation of multi-component hydrogel beads incorporated with reduced graphene oxide (rGO). The beads are prepared by incorporating doxorubicin (DOX)-loaded gelatine (GL) microbeads into hydrogel beads containing rGO and 5-fluorouracil (5-FU). rGO-containing beads are shown to be more effective in inhibiting the growth of MCF-7 cells via the induction of reactive oxygen species (ROS) generation. In addition, the drug release sustainability of the beads is affected by the pH of the release medium, with the release rate increasing in neutral pH but decreasing in the acidic environment. Our beads warrant further development as carriers for pH-responsive and controlled co-delivery of multiple agents.
Oral Proteasomal Inhibitors Ixazomib, Oprozomib, and Delanzomib Upregulate the Function of Organic Anion Transporter 3 (OAT3): Implications in OAT3-Mediated Drug-Drug Interactions
Authors: Fan Yunzhou , Liang Zhengxuan , Zhang Jinghui , You Guofeng
Published: March 2021

Organic anion transporter 3 (OAT3) is mainly expressed at the basolateral membrane of kidney proximal tubules, and is involved in the renal elimination of various kinds of important drugs, potentially affecting drug efficacy or toxicity. Our laboratory previously reported that ubiquitin modification of OAT3 triggers the endocytosis of OAT3 from the plasma membrane to intracellular endosomes, followed by degradation. Oral anticancer drugs ixazomib, oprozomib, and delanzomib, as proteasomal inhibitors, target the ubiquitin–proteasome system in clinics. Therefore, this study investigated the effects of ixazomib, oprozomib, and delanzomib on the expression and transport activity of OAT3 and elucidated the underlying mechanisms. We showed that all three drugs significantly increased the accumulation of ubiquitinated OAT3, which was consistent with decreased intracellular 20S proteasomal activity; stimulated OAT3-mediated transport of estrone sulfate and p-aminohippuric acid; and increased OAT3 surface expression. The enhanced transport activity and OAT3 expression following drug treatment resulted from an increase in maximum transport velocity of OAT3 without altering the substrate binding affinity, and from a decreased OAT3 degradation. Together, our study discovered a novel role of anticancer agents ixazomib, oprozomib, and delanzomib in upregulating OAT3 function, unveiled the proteasome as a promising target for OAT3 regulation, and provided implication of OAT3-mediated drug–drug interactions, which should be warned against during combination therapies with proteasome inhibitor drugs.
Evaluating the Effect a of Handout on Community Pharmacists’ Opioid Safety Counseling
Authors: Thakur Tanvee , Chewning Betty
Published: March 2021

Community pharmacists are the most accessible healthcare professionals to counsel patients about opioid risks and safety. Resources such as handouts are needed to improve pharmacists’ self-efficacy about opioid safety counseling. This study aims to understand the effects and usefulness of handouts in opioid risk and safety counseling in community pharmacists. Three community pharmacies participated in this study for three weeks, where five pharmacists participated in completing a survey about the process and integration of a handout in opioid medication consultation. Pharmacists filled the survey after counseling patients for opioid medication/s. Field observations were conducted at one of these sites as well. A total of 57 consults were recorded via surveys in these pharmacies. Only using the handout to guide the conversation was rated much less useful than integrating the handout and showing it to patient in the consult (β = 0.94, adjusted R2 = 0.29, p < 0.00001). Satisfaction about the patient education provided increased if opioid risks and safety topics were discussed (β = 0.7, adjusted R2 = 0.32, p = 0.00015). Patients seemed engaged in the consults, which was evident from the head nods, questions asked, and attention toward the pharmacist. Effective communication with patients or patient caregivers about opioid safety can be accomplished by using and modeling use of this handout and by providing structured instructions to use this handout optimally.
Flowering Phenology Adjustment and Flower Longevity in a South American Alpine Species
Authors: Arroyo Mary T. K. , Tamburrino Ítalo , Pliscoff Patricio , Robles Valeria , Colldecarrera Maria , Guerrero Pablo C.
Published: March 2021

Delayed flowering due to later snowmelt and colder temperatures at higher elevations in the alpine are expected to lead to flowering phenological adjustment to prevent decoupling of peak flowering from the warmest time of the year, thereby favoring pollination. However, even if flowering is brought forward in the season at higher elevations, an elevational temperature gap is likely to remain between the high- and low-elevation populations of a species at the time these reach peak flowering on account of the atmospheric reduction in temperature with increasing elevation. The negative effect of this temperature gap on pollination could be compensated by plastically-prolonged flower life spans at higher elevations, increasing the probability of pollination. In a tightly temperature-controlled study, the flowering phenology adjustment and flower longevity compensation hypotheses were investigated in an alpine species in the Andes of central Chile. The snow free period varied from 7 to 8.2 months over 810 m elevation. Temperatures were suitable for growth on 82–98% of the snow free days. Flowering onset was temporally displaced at the rate of 4.6 d per 100 m increase in elevation and flowering was more synchronous at higher elevations. Flowering phenology was adjusted over elevation. The latter was manifest in thermal sums tending to decrease with elevation for population flowering onset, 50% flowering, and peak flowering when the lower thermal limit for growth (TBASE) was held constant over elevation. For TBASE graded over elevation so as to reflect the growing season temperature decline, thermal sums did not vary with elevation, opening the door to a possible elevational decline in the thermal temperature threshold for growth. Potential flower longevity was reduced by passive warming and was more prolonged in natural populations when temperatures were lower, indicating a plastic trait. Pollination rates, as evaluated with the Relative Pollination Rate index (RPR), when weighted for differences in floral abundance over the flowering season, declined with elevation as did fruit set. Contrary to expectation, the life-spans of flowers at higher elevations were not more prolonged and failed to compensate for the elevational decrease in pollination rates. Although strong evidence for phenological adjustment was forthcoming, flower longevity compensation did not occur over Oxalis squamata’s elevational range. Thus, flower longevity compensation is not applicable in all alpine species. Comparison with work conducted several decades ago on the same species in the same area provides valuable clues regarding the effects of climate change on flowering phenology and fitness in the central Chilean alpine where temperatures have been increasing and winter snow accumulation has been declining.
Antibacterial and COX-2 Inhibitory Tetrahydrobisbenzylisoquinoline Alkaloids from the Philippine Medicinal Plant Phaeanthus ophthalmicus
Authors: Magpantay Hilbert D. , Malaluan Ivane N. , Manzano Joe Anthony H. , Quimque Mark Tristan , Pueblos Kirstin Rhys , Moor Natalija , Budde Simon , Bangcaya Porferio S. , Lim-Valle Demi , Dahse Hans-Martin , Khan Abbas , Wei Dong-Qing , Alejandro Grecebio Jonathan D. , Macabeo Allan Patrick G.
Published: March 2021

Phaeanthus ophthalmicus (Roxb. ex G.Don) J.Sinclair (previously known as P. ebracteolatus (Presl) Merr) is a Philippine medicinal plant occurring as evergreen shrub in the lowland forests of Luzon islands. It is used traditionally by Filipinos to treat bacterial conjunctivitis, ulcer and wound infections. Based on previous investigations where cyclooxygenase-2 (COX-2) functions as immune-linked factor in infectious sensitivities to bacterial pathogens by triggering pro-inflammatory immune-associated reactions, we investigated the antimicrobial and COX inhibitory activities of the extracts and tetrahydrobisbenzylisoquinoline alkaloids of P. ophthalmicus in vitro and in silico to validate its ethnomedicinal uses. Thus, the dichloromethane–methanol (DCM–MeOH) crude extract and alkaloid extracts exhibiting antibacterial activities against drug-resistant bacterial strains such as methicillin-resistance Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), Klebsiella pneumoniae + CRE and Pseudomonas aeruginosa + MBL afforded (+)-tetrandrine (1) and (+)-limacusine (2) as the major biologically active tetrahydrobisbenzylisoquinoline alkaloidal constituents after purification. Both tetrahydrobisbenzylisoquinoline alkaloids 1 and 2 showed broad spectrum antibacterial activity with strongest inhibition against the Gram-negative bacteria MβL-Pseudomonas aeruginosa Klebsiella pneumoniae + CRE. Interestingly, the alkaloid limacusine (2) showed selective inhibition against ovine COX-2 in vitro. These results were ascertained by molecular docking and molecular dynamics simulation experiments where alkaloid 2 showed strong affinity in the catalytic sites of Gram-negative bacterial enzymes P. aeruginosa elastase and K. pneumoniae KPC-2 carbapenemase (enzymes involved in infectivity mechanisms), and of ovine COX-2. Overall, our study provides credence on the ethnomedicinal use of the Philippine medicinal plant P. ophthalmicus as traditional plant-based adjuvant to treat bacterial conjunctivitis and other related infections. The antibacterial activities and selective COX-2 inhibition observed for limacusine (2) point to its role as the biologically active constituent of P. ophthalmicus. A limited number of drugs with COX-2 inhibitory properties like celecoxib also confer antibacterial activity. Thus, tetrahydrobisbenzyl alkaloids, especially 2, are promising pharmaceutical inspirations for developing treatments of bacterial/inflammation-related infections.
Additive Manufacturing of Polymer Materials: Progress, Promise and Challenges
Authors: Saleh Alghamdi Saad , John Sabu , Roy Choudhury Namita , Dutta Naba K.
Published: March 2021

The use of additive manufacturing (AM) has moved well beyond prototyping and has been established as a highly versatile manufacturing method with demonstrated potential to completely transform traditional manufacturing in the future. In this paper, a comprehensive review and critical analyses of the recent advances and achievements in the field of different AM processes for polymers, their composites and nanocomposites, elastomers and multi materials, shape memory polymers and thermo-responsive materials are presented. Moreover, their applications in different fields such as bio-medical, electronics, textiles, and aerospace industries are also discussed. We conclude the article with an account of further research needs and future perspectives of AM process with polymeric materials.
Effect of Organo-Modified Montmorillonite Nanoclay on Mechanical, Thermo-Mechanical, and Thermal Properties of Carbon Fiber-Reinforced Phenolic Composites
Authors: Pumchusak Jantrawan , Thajina Nonthawat , Keawsujai Watcharakorn , Chaiwan Pattarakamon
Published: March 2021

This work aims to explore the effect of organo-modified montmorillonite nanoclay (O-MMT) on the mechanical, thermo-mechanical, and thermal properties of carbon fiber-reinforced phenolic composites (CFRP). CFRP at variable O-MMT contents (from 0 to 2.5 wt%) were prepared. The addition of 1.5 wt% O-MMT was found to give the heat resistant polymer composite optimum properties. Compared to the CFRP, the CFRP with 1.5 wt% O-MMT provided a higher tensile strength of 64 MPa (+20%), higher impact strength of 49 kJ/m2 (+51%), but a little lower bending strength of 162 MPa (−1%). The composite showed a 64% higher storage modulus at 30 °C of 6.4 GPa. It also could reserve its high modulus up to 145 °C. Moreover, it had a higher heat deflection temperature of 152 °C (+1%) and a higher thermal degradation temperature of 630 °C. This composite could maintain its mechanical properties at high temperature and was a good candidate for heat resistant material.
Influence of Polymeric Restorative Materials on the Stress Distribution in Posterior Fixed Partial Dentures: 3D Finite Element Analysis
Authors: Campaner Larissa Mendes , Silveira Marcos Paulo Motta , de Andrade Guilherme Schmitt , Borges Alexandre Luiz Souto , Bottino Marco Antonio , Dal Piva Amanda Maria de Oliveira , Lo Giudice Roberto , Ausiello Pietro , Tribst João Paulo Mendes
Published: March 2021

Background: This study evaluated the effect of interim restorative materials (acrylic resin (AR), resin composite (RC) or polyetheretherketone (PEEK) for dental computer-aided design/computer-aided manufacturing (CAD/CAM)) on the stress distribution of a posterior three-unit fixed partial denture. Methods: The abutment teeth (first molar and first premolar) were modeled using the BioCAD protocol containing 1.5 mm of axial reduction and converging axial walls. A static structural analysis was performed in the computer-aided engineering software, and the Maximum Principal Stress criterion was used to analyze the prosthesis and the cement layers of both abutment teeth. The materials were considered isotropic, linearly elastic, homogeneous and with bonded contacts. An axial load (600 N) was applied to the occlusal surface of the second premolar. Results: Regardless of the restorative material, the region of the prosthetic connectors showed the highest tensile stress magnitude. The highest stress peak was observed with the use of RC (129 MPa) compared to PEEK and AR. For the cement layers, RC showed the lowest values in the occlusal region (7 MPa) and the highest values for the cervical margin (14 MPa) compared to PEEK (21 and 12 MPa) and AR (21 and 13 MPa). Conclusions: Different interim restorative materials for posterior fixed partial dentures present different biomechanical behavior. The use of resin composite can attenuate the stress magnitude on the cement layer, and the use of acrylic resin can attenuate the stress magnitude on the connector region.
Trends in Chitosan as a Primary Biopolymer for Functional Films and Coatings Manufacture for Food and Natural Products
Authors: Díaz-Montes Elsa , Castro-Muñoz Roberto
Published: March 2021

Some of the current challenges faced by the food industry deal with the natural ripening process and the short shelf-life of fresh and minimally processed products. The loss of vitamins and minerals, lipid oxidation, enzymatic browning, and growth of microorganisms have been the main issues for many years within the innovation and improvement of food packaging, which seeks to preserve and protect the product until its consumption. Most of the conventional packaging are petroleum-derived plastics, which after product consumption becomes a major concern due to environmental damage provoked by their difficult degradation. In this sense, many researchers have shown interest in edible films and coatings, which represent an environmentally friendly alternative for food packaging. To date, chitosan (CS) is among the most common materials in the formulation of these biodegradable packaging together with polysaccharides, proteins, and lipids. The good film-forming and biological properties (i.e., antimicrobial, antifungal, and antiviral) of CS have fostered its usage in food packaging. Therefore, the goal of this paper is to collect and discuss the latest development works (over the last five years) aimed at using CS in the manufacture of edible films and coatings for food preservation. Particular attention has been devoted to relevant findings in the field, together with the novel preparation protocols of such biodegradable packaging. Finally, recent trends in new concepts of composite films and coatings are also addressed.
Interface Strength and Fiber Content Influence on Corn Stover Fibers Reinforced Bio-Polyethylene Composites Stiffness
Authors: Tarrés Quim , Hernández-Díaz David , Ardanuy Mònica
Published: March 2021

Stiffness of material is a key parameter that allows the use of material for structural or semi-structural purposes. Besides, lightweight materials are increasingly calling the attention of the industry. Environmental impact is also increasing in its importance. Bio-based materials produced from renewable sources can be good candidates for structural purposes combining lightweight and low environmental impact. Nonetheless, similar mechanical properties of commodities have to be reached with such materials. In this work, composite materials from corn stover fibers as a bio-polyethylene reinforcement were produced and tested. The effect of coupling agents to improve the fiber–matrix interface has been evaluated. It has been found that coupling agent content influenced the stiffness of the materials, increasing the Young’s modulus and the material processability. The best performance was achieved for a 6% of coupling agent, corresponding to 4.61 GPa for 50 w/w% of corn stover fibers. Micromechanics showed the impact of the semi-random orientation of the fibers and the lesser impact of its morphology. It was possible to determine a triangular packing of the composites as a hypothesis for future research.
Transient Thermal Performance of Power Cable Ascertained Using Finite Element Analysis
Authors: Ghoneim Sherif Salama Mohamed , Ahmed Mahrous , Sabiha Nehmdoh Abdelmotaleb
Published: March 2021

This paper presents the computation of the cable ampacity and the temperature distribution through long duration based on the equivalent thermal circuit based on IEC 60287 standard and the Finite element method using COMSOL (Multiphysics environment, version 5.5). This study investigated the cable ampacity and the temperature rise of the cable core and sheath at steady state and emergency conditions. The cable ampacity was investigated at different conditions such as the variation of cable depth, soil properties, and soil temperature. The results confirmed the adaptation between the thermal circuit results and the COMSOL results as well as the effectiveness of using the numerical method to compute the cable ampacity. Using the COMSOL-based thermal properties evaluations, the transient performance of the cable is ascertained. The transient study is performed for different cable loading currents and dry zone sizes.
How Does the Planck Scale Affect Qubits?
Authors: Lake Matthew J.
Published: March 2021

Gedanken experiments in quantum gravity motivate generalised uncertainty relations (GURs) implying deviations from the standard quantum statistics close to the Planck scale. These deviations have been extensively investigated for the non-spin part of the wave function, but existing models tacitly assume that spin states remain unaffected by the quantisation of the background in which the quantum matter propagates. Here, we explore a new model of nonlocal geometry in which the Planck-scale smearing of classical points generates GURs for angular momentum. These, in turn, imply an analogous generalisation of the spin uncertainty relations. The new relations correspond to a novel representation of SU(2) that acts nontrivially on both subspaces of the composite state describing matter-geometry interactions. For single particles, each spin matrix has four independent eigenvectors, corresponding to two 2-fold degenerate eigenvalues ħ±(ħ+β)/2, where β is a small correction to the effective Planck’s constant. These represent the spin states of a quantum particle immersed in a quantum background geometry and the correction by β emerges as a direct result of the interaction terms. In addition to the canonical qubits states, |0⟩=|↑⟩ and |1⟩=|↓⟩, there exist two new eigenstates in which the spin of the particle becomes entangled with the spin sector of the fluctuating spacetime. We explore ways to empirically distinguish the resulting "geometric" qubits, |0′⟩ and |1′⟩, from their canonical counterparts.
Mapping the Groundwater Level and Soil Moisture of a Montane Peat Bog Using UAV Monitoring and Machine Learning
Authors: Lendzioch Theodora , Langhammer Jakub , Vlček Lukáš , Minařík Robert
Published: March 2021

One of the best preconditions for the sufficient monitoring of peat bog ecosystems is the collection, processing, and analysis of unique spatial data to understand peat bog dynamics. Over two seasons, we sampled groundwater level (GWL) and soil moisture (SM) ground truth data at two diverse locations at the Rokytka Peat bog within the Sumava Mountains, Czechia. These data served as reference data and were modeled with a suite of potential variables derived from digital surface models (DSMs) and RGB, multispectral, and thermal orthoimages reflecting topomorphometry, vegetation, and surface temperature information generated from drone mapping. We used 34 predictors to feed the random forest (RF) algorithm. The predictor selection, hyperparameter tuning, and performance assessment were performed with the target-oriented leave-location-out (LLO) spatial cross-validation (CV) strategy combined with forward feature selection (FFS) to avoid overfitting and to predict on unknown locations. The spatial CV performance statistics showed low (R2 = 0.12) to high (R2 = 0.78) model predictions. The predictor importance was used for model interpretation, where temperature had strong impact on GWL and SM, and we found significant contributions of other predictors, such as Normalized Difference Vegetation Index (NDVI), Normalized Difference Index (NDI), Enhanced Red-Green-Blue Vegetation Index (ERGBVE), Shape Index (SHP), Green Leaf Index (GLI), Brightness Index (BI), Coloration Index (CI), Redness Index (RI), Primary Colours Hue Index (HI), Overall Hue Index (HUE), SAGA Wetness Index (TWI), Plan Curvature (PlnCurv), Topographic Position Index (TPI), and Vector Ruggedness Measure (VRM). Additionally, we estimated the area of applicability (AOA) by presenting maps where the prediction model yielded high-quality results and where predictions were highly uncertain because machine learning (ML) models make predictions far beyond sampling locations without sampling data with no knowledge about these environments. The AOA method is well suited and unique for planning and decision-making about the best sampling strategy, most notably with limited data.
Semi-Supervised Learning for Seismic Impedance Inversion Using Generative Adversarial Networks
Authors: Wu Bangyu , Meng Delin , Zhao Haixia
Published: March 2021

Seismic impedance inversion is essential to characterize hydrocarbon reservoir and detect fluids in field of geophysics. However, it is nonlinear and ill-posed due to unknown seismic wavelet, observed data band limitation and noise, but it also requires a forward operator that characterizes physical relation between measured data and model parameters. Deep learning methods have been successfully applied to solve geophysical inversion problems recently. It can obtain results with higher resolution compared to traditional inversion methods, but its performance often not fully explored for the lack of adequate labeled data (i.e., well logs) in training process. To alleviate this problem, we propose a semi-supervised learning workflow based on generative adversarial network (GAN) for acoustic impedance inversion. The workflow contains three networks: a generator, a discriminator and a forward model. The training of the generator and discriminator are guided by well logs and constrained by unlabeled data via the forward model. The benchmark models Marmousi2, SEAM and a field data are used to demonstrate the performance of our method. Results show that impedance predicted by the presented method, due to making use of both labeled and unlabeled data, are better consistent with ground truth than that of conventional deep learning methods.
Integrating Weighted Feature Fusion and the Spatial Attention Module with Convolutional Neural Networks for Automatic Aircraft Detection from SAR Images
Authors: Wang Jielan , Xiao Hongguang , Chen Lifu , Xing Jin , Pan Zhouhao , Luo Ru , Cai Xingmin
Published: March 2021

The automatic detection of aircrafts from SAR images is widely applied in both military and civil fields, but there are still considerable challenges. To address the high variety of aircraft sizes and complex background information in SAR images, a new fast detection framework based on convolution neural networks is proposed, which achieves automatic and rapid detection of aircraft with high accuracy. First, the airport runway areas are detected to generate the airport runway mask and rectangular contour of the whole airport are generated. Then, a new deep neural network proposed in this paper, named Efficient Weighted Feature Fusion and Attention Network (EWFAN), is used to detect aircrafts. EWFAN integrates the weighted feature fusion module, the spatial attention mechanism, and the CIF loss function. EWFAN can effectively reduce the interference of negative samples and enhance feature extraction, thereby significantly improving the detection accuracy. Finally, the airport runway mask is applied to the detected results to reduce false alarms and produce the final aircraft detection results. To evaluate the performance of the proposed framework, large-scale Gaofen-3 SAR images with 1 m resolution are utilized in the experiment. The detection rate and false alarm rate of our EWFAN algorithm are 95.4% and 3.3%, respectively, which outperforms Efficientdet and YOLOv4. In addition, the average test time with the proposed framework is only 15.40 s, indicating satisfying efficiency of automatic aircraft detection.
Statistical Characteristics of the Response of Sea Surface Temperatures to Westward Typhoons in the South China Sea
Authors: Ma Zhaoyue , Zhang Yuanzhi , Wu Renhao , Na Rong
Published: March 2021

The strong interaction between a typhoon and ocean air is one of the most important forms of typhoon and sea air interaction. In this paper, the daily mean sea surface temperature (SST) data of Advanced Microwave Scanning Radiometer for Earth Observation System (EOS) (AMSR-E) are used to analyze the reduction in SST caused by 30 westward typhoons from 1998 to 2018. The findings reveal that 20 typhoons exerted obvious SST cooling areas. Moreover, 97.5% of the cooling locations appeared near and on the right side of the path, while only one appeared on the left side of the path. The decrease in SST generally lasted 6–7 days. Over time, the cooling center continued to diffuse, and the SST gradually rose. The slope of the recovery curve was concentrated between 0.1 and 0.5.
Geodetic-Gravimetric Monitoring of Mountain Uplift and Hydrological Variations at Zugspitze and Wank Mountains (Bavarian Alps, Germany)
Authors: Timmen Ludger , Gerlach Christian , Rehm Till , Völksen Christof , Voigt Christian
Published: March 2021

In 2004, first absolute gravity (AG) measurements were performed on the top of Mt. Zugspitze (2 sites) and at the foot (1 site) and top (1 site) of Mt. Wank. Mt. Wank (summit height 1780 m) and Mt. Zugspitze (2960 m) are about 15 km apart from each other and belong geologically to different parts of the Northern Limestone Alps. Bridging a time span of 15 years, the deduced gravity variations for Zugspitze are in the order of −0.30 μm/s2 with a standard uncertainty of 0.04 μm/s2. The Wank stations (foot and top) show no significant gravity variation. The vertical stability of Wank summit is also confirmed by results of continuous GNSS recordings. Because an Alpine mountain uplift of 1 or 2 mm/yr cannot explain the obtained gravity decline at Zugspitze, the dominating geophysical contributions are assumed to be due to the diminishing glaciers in the vicinity. The modelled gravity trend caused by glacier retreat between epochs 1999 and 2018 amounts to −0.012 μm/s2/yr at both Zugspitze AG sites. This explains more than half of the observed gravity decrease. Long-term variations on inter-annual and climate-relevant decadal scale will be investigated in the future using as supplement superconducting gravimetry (installed in 2019) and GNSS equipment (since 2018).
On the Spectral and Polarimetric Signatures of a Bright Scatterer before and after Hardware Replacement
Authors: Gabella Marco
Published: March 2021

A previous study has used the stable and peculiar echoes backscattered by a single “bright scatterer” (BS) during five winter days to characterize the hardware of C-band, the dual-polarization radar located at Monte Lema (1625 m altitude) in Southern Switzerland. The BS is the 90 m tall metallic tower on Cimetta (1633 m altitude, 18 km range). In this note, the statistics of the echoes from the BS were derived from other ten dry days with normal propagation conditions in winter 2015 and January 2019. The study confirms that spectral signatures, such as spectrum width, wideband noise and Doppler velocity, were persistently stable. Regarding the polarimetric signatures, the large values (with small dispersion) of the copolar correlation coefficient between horizontal and vertical polarization were also confirmed: the average value was 0.9961 (0.9982) in winter 2015 (January 2019); the daily standard deviations were very small, ranging from 0.0007 to 0.0030. The dispersion of the differential phase shift was also confirmed to be quite small: the daily standard deviation ranged from a minimum of 2.5° to a maximum of 5.3°. Radar reflectivities in both polarizations were typically around 80 dBz and were confirmed to be among the largest values observed in the surveillance volume of the Monte Lema radar. Finally, another recent 5-day data set from January 2020 was analyzed after the replacement of the radar calibration unit that includes low noise amplifiers: these five days show poorer characteristics of the polarimetric signatures and a few outliers affecting the spectral signatures. It was shown that the “historical” polarimetric and spectral signatures of a bright scatterer could represent a benchmark for an in-depth comparison after hardware replacements.
Research on Cooperative Perception of MUSVs in Complex Ocean Conditions
Authors: Yin Lili , Zhang Rubo , Gu Hengwen , Li Peng
Published: March 2021

Since the working environment of Multiple Unmanned Surface Vehicles (MUSVs) is accompanied by a large number of uncertainties and various hazards, in order to ensure the collision avoidance capability of MUSVs in complex marine environments, the perception of complex marine environments by MUSVs is the first problem that needs to be solved. A cooperative perception framework with uncertain event detection, cooperative collision avoidance pattern recognition and environmental ontology model is proposed to realize the cooperative perception process of MUSVs using ontology and Bayesian network theory. The cooperative perception approach was validated by simulating experiments. Results show the effectiveness of cooperative perception approach.
Bipartite Network of Interest (BNOI): Extending Co-Word Network with Interest of Researchers Using Sensor Data and Corresponding Applications as an Example
Authors: Dai Zongming , Hu Kai , Xie Jie , Shen Shengyu , Zheng Jie , Wu Huayi , Guo Ya
Published: March 2021

Traditional co-word networks do not discriminate keywords of researcher interest from general keywords. Co-word networks are therefore often too general to provide knowledge if interest to domain experts. Inspired by the recent work that uses an automatic method to identify the questions of interest to researchers like “problems” and “solutions”, we try to answer a similar question “what sensors can be used for what kind of applications”, which is great interest in sensor- related fields. By generalizing the specific questions as “questions of interest”, we built a knowledge network considering researcher interest, called bipartite network of interest (BNOI). Different from a co-word approaches using accurate keywords from a list, BNOI uses classification models to find possible entities of interest. A total of nine feature extraction methods including N-grams, Word2Vec, BERT, etc. were used to extract features to train the classification models, including naïve Bayes (NB), support vector machines (SVM) and logistic regression (LR). In addition, a multi-feature fusion strategy and a voting principle (VP) method are applied to assemble the capability of the features and the classification models. Using the abstract text data of 350 remote sensing articles, features are extracted and the models trained. The experiment results show that after removing the biased words and using the ten-fold cross-validation method, the F-measure of “sensors” and “applications” are 93.2% and 85.5%, respectively. It is thus demonstrated that researcher questions of interest can be better answered by the constructed BNOI based on classification results, comparedwith the traditional co-word network approach.
Out-of-Distribution Detection of Human Activity Recognition with Smartwatch Inertial Sensors
Authors: Boyer Philip , Burns David , Whyne Cari
Published: March 2021

Out-of-distribution (OOD) in the context of Human Activity Recognition (HAR) refers to data from activity classes that are not represented in the training data of a Machine Learning (ML) algorithm. OOD data are a challenge to classify accurately for most ML algorithms, especially deep learning models that are prone to overconfident predictions based on in-distribution (IIN) classes. To simulate the OOD problem in physiotherapy, our team collected a new dataset (SPARS9x) consisting of inertial data captured by smartwatches worn by 20 healthy subjects as they performed supervised physiotherapy exercises (IIN), followed by a minimum 3 h of data captured for each subject as they engaged in unrelated and unstructured activities (OOD). In this paper, we experiment with three traditional algorithms for OOD-detection using engineered statistical features, deep learning-generated features, and several popular deep learning approaches on SPARS9x and two other publicly-available human activity datasets (MHEALTH and SPARS). We demonstrate that, while deep learning algorithms perform better than simple traditional algorithms such as KNN with engineered features for in-distribution classification, traditional algorithms outperform deep learning approaches for OOD detection for these HAR time series datasets.
Communication Planning for Cooperative Terrain-Based Underwater Localization
Authors: Anderson Jacob , Hollinger Geoffrey A.
Published: March 2021

This paper presents a decentralized communication planning algorithm for cooperative terrain-based navigation (dec-TBN) with autonomous underwater vehicles. The proposed algorithm uses forward simulation to approximate the value of communicating at each time step. The simulations are used to build a directed acyclic graph that can be searched to provide a minimum cost communication schedule. Simulations and field trials are used to validate the algorithm. The simulations use a real-world bathymetry map from Lake Nighthorse, CO, and a sensor model derived from an Ocean Server Iver2 vehicle. The simulation results show that the algorithm finds a communication schedule that reduces communication bandwidth by 86% and improves robot localization by up to 27% compared to non-cooperative terrain-based navigation. Field trials were conducted in Foster Reservoir, OR, using two Riptide Autonomous Solutions micro-unmanned underwater vehicles. The vehicles collected GPS, altimeter, acoustic communications, and dead reckoning data while following paths on the surface of the reservoir. The data were used to evaluate the planning algorithm. In three of four missions, the planning algorithm improved dec-TBN localization while reducing acoustic communication bandwidth by 56%. In the fourth mission, dec-TBN performed better when using full communications bandwidth, but the communication policy for that mission maintained 86% of the localization accuracy while using 9% of the communications. These results indicate that the presented communication planning algorithm can maintain or improve dec-TBN accuracy while reducing the number of communications used for localization.
A Facile One-Pot Approach to the Synthesis of Gd-Eu Based Metal-Organic Frameworks and Applications to Sensing of Fe3+ and Cr2O72− Ions
Authors: Puglisi Roberta , Pellegrino Anna L. , Fiorenza Roberto , Scirè Salvatore , Malandrino Graziella
Published: March 2021

Gadolinium metal-organic frameworks (Gd-MOFs) and Eu-doped Gd-MOFs have been synthesized through a one-pot green approach using commercially available reagents. The 1,4-benzenedicarboxylic acid (H2-BDC) and 2,6-naphthalenedicarboxylic acid (H2-NDC) were chosen as ditopic organic linkers to build the 3D structure of the network. The Gd-MOFs were characterized using powder X-ray diffraction (XRD), FT-IR spectroscopy, field emission scanning electron microscopy (FE-SEM) and N2 adsorption–desorption analysis. The Gd-MOF structures were attributed comparing the XRD patterns, supported by the FT-IR spectra, with data reported in the literature for Ln-MOFs of similar lanthanide ionic radius. FE-SEM characterization points to the effect of the duration of the synthesis to a more crystalline and organized structure, with grain dimensions increasing upon increasing reaction time. The total surface area of the MOFs has been determined from the application of the Brunauer–Emmett–Teller method. The study allowed us to correlate the processing conditions and ditopic linker dimension to the network surface area. Both Gd-MOF and Eu-doped Gd-MOF have been tested for sensing of the inorganic ions such as Fe3+ and Cr2O72−.