bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of Mitochondria in the Chemoresistance of Pancreatic Cancer Cells
Authors: Fu Yibo , Ricciardiello Francesca , Yang Gang , Qiu Jiangdong , Huang Hua , Xiao Jianchun , Cao Zhe , Zhao Fangyu , Liu Yueze , Luo Wenhao , Chen Guangyu , You Lei , Chiaradonna Ferdinando , Zheng Lianfang , Zhang Taiping
Published: February 2021

The first-line chemotherapies for patients with unresectable pancreatic cancer (PC) are 5-fluorouracil (5-FU) and gemcitabine therapy. However, due to chemoresistance the prognosis of patients with PC has not been significantly improved. Mitochondria are essential organelles in eukaryotes that evolved from aerobic bacteria. In recent years, many studies have shown that mitochondria play important roles in tumorigenesis and may act as chemotherapeutic targets in PC. In addition, according to recent studies, mitochondria may play important roles in the chemoresistance of PC by affecting apoptosis, metabolism, mtDNA metabolism, and mitochondrial dynamics. Interfering with some of these factors in mitochondria may improve the sensitivity of PC cells to chemotherapeutic agents, such as gemcitabine, making mitochondria promising targets for overcoming chemoresistance in PC.
Multi-Modal Multi-Spectral Intravital Microscopic Imaging of Signaling Dynamics in Real-Time during Tumor–Immune Interactions
Authors: Liu Tracy W. , Gammon Seth T. , Piwnica-Worms David
Published: February 2021

Intravital microscopic imaging (IVM) allows for the study of interactions between immune cells and tumor cells in a dynamic, physiologically relevant system in vivo. Current IVM strategies primarily use fluorescence imaging; however, with the advances in bioluminescence imaging and the development of new bioluminescent reporters with expanded emission spectra, the applications for bioluminescence are extending to single cell imaging. Herein, we describe a molecular imaging window chamber platform that uniquely combines both bioluminescent and fluorescent genetically encoded reporters, as well as exogenous reporters, providing a powerful multi-plex strategy to study molecular and cellular processes in real-time in intact living systems at single cell resolution all in one system. We demonstrate that our molecular imaging window chamber platform is capable of imaging signaling dynamics in real-time at cellular resolution during tumor progression. Importantly, we expand the utility of IVM by modifying an off-the-shelf commercial system with the addition of bioluminescence imaging achieved by the addition of a CCD camera and demonstrate high quality imaging within the reaches of any biology laboratory.
Double Diapering Ineffectiveness in Avoiding Adduction and Extension in Newborns Hips
Authors: De Pellegrin Maurizio , Damia Chiara Maria , Marcucci Lorenzo , Moharamzadeh Desiree
Published: February 2021

Hip flexion and abduction is fundamental for developmental dysplasia of the hip (DDH) treatment. At present, double diaper treatment has been inappropriately adopted when DDH is suspected. The aim of this study was to verify whether double diapers influence a newborn’s hip position. Here, we studied 50 children (23 female; 27 male; average age 62.33 ± 20.50 days; average birth weight 3230 ± 447 g) with type I hips according to Graf. At the same time of the ultrasound (US) examination, the following hip positions were measured using a manual protractor: (1) spontaneous position, supine on the outpatient bed without a diaper; (2) spontaneous position, with a double diaper; and (3) squatting position on the caretakers’ side. Statistical analysis was performed with a t-test to compare between (1) the spontaneous position without a diaper and with double diapers; (2) the spontaneous position with double diapers as well as the squatting position on the caretakers’ side with a diaper. The comparison between the hip position without diaper and with double diapers was statistically not significant for all measurements, i.e., right hip flexion (p < 0.33), left hip flexion (p < 0.34), and right and left hip abduction (p < 0.87). The comparison between the hip position with double diapers and on the caretakers’ side was statistically significant for all measurements, i.e., right hip flexion (p < 0.001), left hip flexion (p < 0.001) and right and left hip abduction (p < 0.001). We found that the use of double diapers did not affect hip position, while the position formed on the caretaker’s side shows favorable influence.
Discontinuing Hemodialysis with Patient Care and a Successful 9-Year Follow-up in a Patient Presumed to have End-Stage Kidney Disease Scheduled to Lifelong Hemodialysis: A Case Report
Authors: Toprak Omer , Bozyel Emel Aslan , Alp Burak
Published: February 2021

End-stage kidney disease patients who require hemodialysis for more than 3 months have a small chance of leaving dialysis unless they have a kidney transplant. Educating the patient about lifestyle changes can play a major role in improving kidney function. Therefore, we created a patient education program according to our nephrology experiences. Herein, we show an end-stage kidney disease patient who underwent hemodialysis for 6 months. Afterwards, dialysis was terminated with patient care, and the patient was then followed up for 9 years without dialysis. To date, there have been no reports regarding the termination of long-term dialysis with a kidney care program and the ensuing 9-year follow-up without renal replacement therapy.
Circadian Rhythms of the Hypothalamus: From Function to Physiology
Authors: Van Drunen Rachel , Eckel-Mahan Kristin
Published: February 2021

The nearly ubiquitous expression of endogenous 24 h oscillations known as circadian rhythms regulate the timing of physiological functions in the body. These intrinsic rhythms are sensitive to external cues, known as zeitgebers, which entrain the internal biological processes to the daily environmental changes in light, temperature, and food availability. Light directly entrains the master clock, the suprachiasmatic nucleus (SCN) which lies in the hypothalamus of the brain and is responsible for synchronizing internal rhythms. However, recent evidence underscores the importance of other hypothalamic nuclei in regulating several essential rhythmic biological functions. These extra-SCN hypothalamic nuclei also express circadian rhythms, suggesting distinct regions that oscillate either semi-autonomously or independent of SCN innervation. Concurrently, the extra-SCN hypothalamic nuclei are also sensitized to fluctuations in nutrient and hormonal signals. Thus, food intake acts as another powerful entrainer for the hypothalamic oscillators’ mediation of energy homeostasis. Ablation studies and genetic mouse models with perturbed extra-SCN hypothalamic nuclei function reveal their critical downstream involvement in an array of functions including metabolism, thermogenesis, food consumption, thirst, mood and sleep. Large epidemiological studies of individuals whose internal circadian cycle is chronically disrupted reveal that disruption of our internal clock is associated with an increased risk of obesity and several neurological diseases and disorders. In this review, we discuss the profound role of the extra-SCN hypothalamic nuclei in rhythmically regulating and coordinating body wide functions.
Characterization of Arctic Driftwood as Naturally Modified Material. Part 1: Machinability
Authors: Chuchala Daniel , Sandak Anna , Orlowski Kazimierz A. , Sandak Jakub , Eggertsson Olafur , Landowski Michal
Published: February 2021

Arctic driftwood has reached the coast of Iceland for centuries. This material was used by the inhabitants of the island as a building material for houses, boats, churches and pasture fences. Nowadays, the driftwood is used in the furniture industry, for the finishing of internal and external walls of buildings and also by artists. The properties of driftwood differ to that of original resource due the long-term effects of exposure to Arctic Sea water and ice. This process can be considered as a natural modification, even if its effect on various wood properties and the potential use of driftwood are not yet fully understand. This research is focused on the comparison of cutting forces measured for Siberian larch (Larix sibirica L.) from Siberia provenance and driftwood found on the coast of Iceland. The cutting forces were determined directly from the cutting power signal that was recorded during the frame sawing process. A new procedure for compensation of the late/early wood ratio variation within annual rings is proposed to homogenize mechanical properties of wood. It allows a direct comparison of machinability for both types of larch wood investigated (driftwood and natural). Noticeable differences of normalized cutting force values were noticed for both wood types, which were statistically significant for two set values of feed per tooth. These results provide a new understanding of the effect of the drifting process in the Arctic Sea (natural modification) on mechanical and physical properties of wood. Such a natural modification may influence transformation processes of driftwood as well as performance of the coating systems applied on its surface.
Neutron and XRD Single-Crystal Diffraction Study and Vibrational Properties of Whitlockite, the Natural Counterpart of Synthetic Tricalcium Phosphate
Authors: Capitelli Francesco , Bosi Ferdinando , Capelli Silvia C. , Radica Francesco , Della Ventura Giancarlo
Published: February 2021

A crystal chemical investigation of a natural specimen of whitlockite, ideally Ca9Mg(PO4)6[PO3(OH)], from Palermo Mine (USA), was achieved by means of a combination of electron microprobe analysis (EMPA) in WDS mode, single-crystal neutron diffraction probe (NDP) and single-crystal X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. The crystal-chemical characterization resulted in the empirical formula (Ca8.682Na0.274Sr0.045)Σ9.000(Ca0.034□0.996)Σ1.000(Mg0.533Fe2+0.342Mn2+0.062Al0.046)Σ0.983(P1.006O4)6[PO3(OH0.968F0.032)Σ1.000]. Crystal-structure refinement, in the space group R3c, converged to R1 = 7.12% using 3273 unique reflections from NDP data and to R1 = 2.43% using 2687 unique reflections from XRD data. Unit cell parameters from NDP are a = 10.357(3) Å, c = 37.095(15) Å and V = 3446(2) Å3, and from XRD, the parameters are a = 10.3685(4) Å, c = 37.1444(13) Å and V = 3458.2(3) Å3. NDP results allowed a deeper definition of the hydrogen-bond system and its relation with the structural unit [PO3(OH)]. The FTIR spectrum is very similar to that of synthetic tricalcium phosphate Ca3(PO4)2 and displays minor band shifts due to slightly different P-O bond lengths and to the presence of additional elements in the structure. A comparison between whitlockite, isotypic phases from the largest merrillite group, and its synthetic counterpart Ca3(PO4)2 is provided, based on the XRD/NDP and FTIR results.
Plasmonic Au–Pd Bimetallic Nanocatalysts for Hot-Carrier-Enhanced Photocatalytic and Electrochemical Ethanol Oxidation
Authors: Boltersdorf Jonathan , Leff Asher C. , Forcherio Gregory T. , Baker David R.
Published: February 2021

Gold–palladium (Au–Pd) bimetallic nanostructures with engineered plasmon-enhanced activity sustainably drive energy-intensive chemical reactions at low temperatures with solar simulated light. A series of alloy and core–shell Au–Pd nanoparticles (NPs) were prepared to synergistically couple plasmonic (Au) and catalytic (Pd) metals to tailor their optical and catalytic properties. Metal-based catalysts supporting a localized surface plasmon resonance (SPR) can enhance energy-intensive chemical reactions via augmented carrier generation/separation and photothermal conversion. Titania-supported Au–Pd bimetallic (i) alloys and (ii) core–shell NPs initiated the ethanol (EtOH) oxidation reaction under solar-simulated irradiation, with emphasis toward driving carbon–carbon (C–C) bond cleavage at low temperatures. Plasmon-assisted complete oxidation of EtOH to CO2, as well as intermediary acetaldehyde, was examined by monitoring the yield of gaseous products from suspended particle photocatalysis. Photocatalytic, electrochemical, and photoelectrochemical (PEC) results are correlated with Au–Pd composition and homogeneity to maintain SPR-induced charge separation and mitigate the carbon monoxide poisoning effects on Pd. Photogenerated holes drive the photo-oxidation of EtOH primarily on the Au-Pd bimetallic nanocatalysts and photothermal effects improve intermediate desorption from the catalyst surface, providing a method to selectively cleave C–C bonds.
Semiconductor Heteroepitaxy
Authors: Bergamaschini Roberto , Vitiello Elisa
Published: February 2021

The quest for high-performance and scalable devices required for next-generation semiconductor applications inevitably passes through the fabrication of high-quality materials and complex designs [...]
High Anisotropic Thermal Conductivity, Long Durability Form-Stable Phase Change Composite Enhanced by a Carbon Fiber Network Structure
Authors: Dong Kaixin , Sheng Nan , Zou Deqiu , Wang Cheng , Yi Xuemei , Nomura Takahiro
Published: February 2021

To address the drawback of low thermal conductivity of conventional organic phase change materials (PCMs), a paraffin-wax-based phase change composite (PCC) was assembled via a vacuum impregnation method, using a new type of carbon fiber network material as the supporting matrix. The carbon fiber sheet (CFS) material exhibited a network structure comprising high-thermal-conductivity carbon fibers, beneficial for enhancing the heat transfer properties of the PCC. The sheet-shaped carbon fiber material was stacked and compressed, and then impregnated with the liquid paraffin wax PCM to form the composite. The thermal conductivity, durability, shape stability, chemical stability, and heat storage characteristics of the PCC specimen were carefully analyzed. The maximum thermal conductivity of the PCC was 11.68 W·m−1·K−1 (4670% compared to that of pure paraffin) in the radial direction, and 0.93 W·m−1·K−1 in the axial direction of the sample, with 17.44 vol % of added CFS. The thermal conductivity retention rate after 200 thermal cycles was 78.6%. The PCC also displayed good stability in terms of chemical structure, shape, and heat storage ability. This study offers insights and a possible strategy for the development of anisotropic high-thermal-conductivity PCCs for potential applications in latent heat storage systems.
Being a Patient Representative Is More Work Than Being a Patient Advocate—Done Right, It Is Also Likely to Be More Effective
Authors: Wassersug Richard
Published: February 2021

For a patient to be effective as a “patient representative” within a health-related organization, work and more than just accepting an honorific title is required. I argue that for a patient to be most effective as a patient representative requires different types of background knowledge and commitment than being a “patient advocate”. Patients need to be cautious about how, when, and where they take on an official role of either an “advocate” or “representative”, if they truly want to be a positive influence on health outcomes.
Origins of Six Species of Butterflies Migrating through Northeastern Mexico: New Insights from Stable Isotope (δ2H) Analyses and a Call for Documenting Butterfly Migrations
Authors: Hobson Keith A. , Kusack Jackson W. , Mora-Alvarez Blanca X.
Published: February 2021

Determining migratory connectivity within and among diverse taxa is crucial to their conservation. Insect migrations involve millions of individuals and are often spectacular. However, in general, virtually nothing is known about their structure. With anthropogenically induced global change, we risk losing most of these migrations before they are even described. We used stable hydrogen isotope (δ2H) measurements of wings of seven species of butterflies (Libytheana carinenta, Danaus gilippus, Phoebis sennae, Asterocampa leilia, Euptoieta claudia, Euptoieta hegesia, and Zerene cesonia) salvaged as roadkill when migrating in fall through a narrow bottleneck in northeast Mexico. These data were used to depict the probabilistic origins in North America of six species, excluding the largely local E. hegesia. We determined evidence for long-distance migration in four species (L. carinenta, E. claudia, D. glippus, Z. cesonia) and present evidence for panmixia (Z. cesonia), chain (Libytheana carinenta), and leapfrog (Danaus gilippus) migrations in three species. Our investigation underlines the utility of the stable isotope approach to quickly establish migratory origins and connectivity in butterflies and other insect taxa, especially if they can be sampled at migratory bottlenecks. We make the case for a concerted effort to atlas butterfly migrations using the stable isotope approach.
Production Performance of Moina macrocopa (Straus 1820) (Crustacea, Cladocera) Cultured in Different Salinities: The Effect on Growth, Survival, Reproduction, and Fatty Acid Composition of the Neonates
Authors: Yuslan Amirah , Najuwa Sharifah , Hagiwara Atsushi , Ghaffar Mazlan A. , Suhaimi Hidayu , Rasdi Nadiah W.
Published: February 2021

Salinity is a known factor in shaping population dynamics and community structure through direct and indirect effects on aquatic ecosystems. Salinity changes further influence food webs through competition and predation. The responses of Moina macrocopa (Cladocera) collected from Setiu Wetland lagoon (Terengganu) was evaluated through manipulative laboratory experiments to understand the ability of M. macrocopa to tolerate high salinity stress. Specifically, the fatty acid composition, growth, survival, and reproduction of this cladocerans species was examined. Sodium chloride (NaCl) as used in the treatments water with the concentration 0, 4, 6, 8, 12, and 15 salinity. Fatty acid levels were determined using Gas Chromatography and Mass Spectrophotometry (GC-MS). The results indicated that optimal conditions produced the highest fatty acid content, especially the polyunsaturated fatty acid content, such as EPA (eicosapentaenoic acid), ALA (alpha-linoleic acid), ARA (arachidonic acid), and DHA (docosahexaenoic acid). Furthermore, M. macrocopa survival was best at salinity 0, with a percentage of 98%, whereas the opposite occurred at salinity 15, with approximately 20% of viable animals surviving. Besides, M. macrocopa also showed the highest reproduction rate at salinity 0 (e.g., average initial age of reproduction, 4.33 ± 0.58 days) compared with other salinities level. Interestingly, the difference in growth at different salinities was not evident, an unusual finding when considering adverse effects such as osmoregulation pressure on the organism. Based on the results, we conclude that M. macrocopa can only tolerate salinity below salinity 8 and cannot withstand stressful environmental conditions associated with salinities above 8.
Preclinical Evaluation of Artesunate as an Antineoplastic Agent in Ovarian Cancer Treatment
Authors: McDowell Anthony , Hill Kristen S. , McCorkle Joseph Robert , Gorski Justin , Zhang Yilin , Salahudeen Ameen A. , Ueland Fred , Kolesar Jill M.
Published: February 2021

Background: Ovarian cancer is the deadliest gynecologic malignancy despite current first-line treatment with a platinum and taxane doublet. Artesunate has broad antineoplastic properties but has not been investigated in combination with carboplatin and paclitaxel for ovarian cancer treatment. Methods: Standard cell culture technique with commercially available ovarian cancer cell lines were utilized in cell viability, DNA damage, and cell cycle progression assays to qualify and quantify artesunate treatment effects. Additionally, the sequence of administering artesunate in combination with paclitaxel and carboplatin was determined. The activity of artesunate was also assessed in 3D organoid models of primary ovarian cancer and RNAseq analysis was utilized to identify genes and the associated genetic pathways that were differentially regulated in artesunate resistant organoid models compared to organoids that were sensitive to artesunate. Results: Artesunate treatment reduces cell viability in 2D and 3D ovarian cancer cell models. Clinically relevant concentrations of artesunate induce G1 arrest, but do not induce DNA damage. Pathways related to cell cycle progression, specifically G1/S transition, are upregulated in ovarian organoid models that are innately more resistant to artesunate compared to more sensitive models. Depending on the sequence of administration, the addition of artesunate to carboplatin and paclitaxel improves their effectiveness. Conclusions: Artesunate has preclinical activity in ovarian cancer that merits further investigation to treat ovarian cancer.
High-Risk Prostate Cancer: A Very Challenging Disease in the Field of Uro-Oncology
Authors: Napodano Giorgio , Ferro Matteo , Sanseverino Roberto
Published: February 2021

Prostate cancer (PCa) is the most common cancer in males and affects 16% of men during their lifetime [...]
Clinical Impact of Vertical Artifacts Changing with Frequency in Lung Ultrasound
Authors: Buda Natalia , Skoczylas Agnieszka , Demi Marcello , Wojteczek Anna , Cylwik Jolanta , Soldati Gino
Published: February 2021

Background: This study concerns the application of lung ultrasound (LUS) for the evaluation of the significance of vertical artifact changes with frequency and pleural line abnormalities in differentiating pulmonary edema from pulmonary fibrosis. Study Design and Methods: The study was designed as a diagnostic test. Having qualified patients for the study, an ultrasound examination was performed, consistent with a predetermined protocol, and employing convex and linear transducers. We investigated the possibility of B-line artifact conversion depending on the set frequency (2 MHz and 6 MHz), and examined pleural line abnormalities. Results: The study group comprised 32 patients with interstitial lung disease (ILD) (and fibrosis) and 30 patients with pulmonary edema. In total, 1941 cineloops were obtained from both groups and analyzed. The employment of both types of transducers (linear and convex) was most effective (specificity 91%, specificity 97%, positive predictive value (PPV) 97%, negative predictive value (NPV) 91%, LR(+) 27,19, LR(−) 0.097, area under curve (AUC) = 0.936, p = 7 × 10−6). Interpretation: The best accuracy in differentiating the etiology of B-line artifacts was obtained with the use of both types of transducers (linear and convex), complemented with the observation of the conversion of B-line artifacts to Z-line.
Non-Specific Low Back Pain and Lumbar Radiculopathy: Comparison of Morphologic and Compositional MRI as Assessed by gagCEST Imaging at 3T
Authors: Frenken Miriam , Nebelung Sven , Schleich Christoph , Müller-Lutz Anja , Radke Karl Ludger , Kamp Benedikt , Boschheidgen Matthias , Wollschläger Lena , Bittersohl Bernd , Antoch Gerald , Konieczny Markus R. , Abrar Daniel B.
Published: February 2021

Using glycosaminoglycan Chemical Exchange Saturation Transfer (gagCEST) magnetic resonance imaging (MRI), this study comparatively evaluated the GAG contents of lumbar intervertebral disks (IVDs) of patients with non-specific low back pain (nsLBP), radiculopathy, and asymptomatic volunteers to elucidate the association of clinical manifestation and compositional correlate. A total of 18 patients (mean age 57.5 ± 22.5 years) with radiculopathy, 16 age-matched patients with chronic nsLBP and 20 age-matched volunteers underwent standard morphologic and compositional gagCEST MRI on a 3T scanner. In all cohorts, GAG contents of lumbar IVDs were determined using gagCEST MRI. An assessment of morphologic IVD degeneration based on the Pfirrmann classification and T2-weighted sequences served as a reference. A linear mixed model adjusted for multiple confounders was used for statistical evaluation. IVDs of patients with nsLBP showed lower gagCEST values than those of volunteers (nsLBP: 1.3% [99% confidence intervals (CI): 1.0; 1.6] vs. volunteers: 1.9% [99% CI: 1.6; 2.2]). Yet, IVDs of patients with radiculopathy (1.8% [99% CI: 1.4; 2.1]) were not different from patients with nsLBP or volunteers. In patients with radiculopathy, IVDs directly adjacent to IVD extrusions demonstrated lower gagCEST values than distant IVDs (adjacent: 0.9% [99% CI: 0.3; 1.5], distant: 2.1% [99% CI: 1.7; 2.5]). Advanced GAG depletion in nsLBP and directly adjacent to IVD extrusions in radiculopathy indicates close interrelatedness of clinical pathology and compositional degeneration.
Individualised Funding: A Realist Analysis to Identify the Causal Factors That Facilitate Positive Outcomes
Authors: Fleming Padraic , McGilloway Sinead , Thomas Steve
Published: February 2021

There is growing interest, internationally, in empowering people with disabilities, and the United Nations have identified individualised funding as one way in which empowerment might be achieved. ‘Individualised funding’ is an umbrella term for various publicly funded support structures that provide personalised and individualised support services for people with a disability. These aim to facilitate self-direction, empowerment, independence, and self-determination. The findings of a recent mixed-methods systematic review of studies undertaken during an approximate 25-year period suggest positive effects with respect to quality of life, client satisfaction, and safety, as well as very few adverse effects, although the evidence on cost-effectiveness was inconclusive. This paper involved a re-examination of the qualitative findings of that review by employing a realist framework to explore the interplay between key contexts and mechanisms, and how these facilitate or inhibit positive outcomes associated with individualised funding and its underlying programme theory.
Nonequilibrium Thermodynamics in Biochemical Systems and Its Application
Authors: Zhang Dongliang , Ouyang Qi
Published: February 2021

Living systems are open systems, where the laws of nonequilibrium thermodynamics play the important role. Therefore, studying living systems from a nonequilibrium thermodynamic aspect is interesting and useful. In this review, we briefly introduce the history and current development of nonequilibrium thermodynamics, especially that in biochemical systems. We first introduce historically how people realized the importance to study biological systems in the thermodynamic point of view. We then introduce the development of stochastic thermodynamics, especially three landmarks: Jarzynski equality, Crooks’ fluctuation theorem and thermodynamic uncertainty relation. We also summarize the current theoretical framework for stochastic thermodynamics in biochemical reaction networks, especially the thermodynamic concepts and instruments at nonequilibrium steady state. Finally, we show two applications and research paradigms for thermodynamic study in biological systems.
Parallel Mixed Image Encryption and Extraction Algorithm Based on Compressed Sensing
Authors: Yu Jiayin , Li Chao , Song Xiaomeng , Guo Shiyu , Wang Erfu
Published: February 2021

In the actual image processing process, we often encounter mixed images that contain multiple valid messages. Such images not only need to be transmitted safely, but also need to be able to achieve effective separation at the receiving end. This paper designs a secure and efficient encryption and separation algorithm based on this kind of mixed image. Since chaotic system has the characteristics of initial sensitivity and pseudo-randomness, a chaos matrix is introduced into the compressed sensing framework. By using sequence signal to adjust the chaotic system, the key space can be greatly expanded. In the algorithm, we take the way of parallel transmission to block the data. This method can realize the efficient calculation of complex tasks in the image encryption system and improve the data processing speed. In the decryption part, the algorithm in this paper can not only realize the restoration of images, but also complete the effective separation of images through the improved restoration algorithm.
A New Pooling Approach Based on Zeckendorf’s Theorem for Texture Transfer Information
Authors: Vigneron Vincent , Maaref Hichem , Syed Tahir Q.
Published: February 2021

The pooling layer is at the heart of every convolutional neural network (CNN) contributing to the invariance of data variation. This paper proposes a pooling method based on Zeckendorf’s number series. The maximum pooling layers are replaced with Z pooling layer, which capture texels from input images, convolution layers, etc. It is shown that Z pooling properties are better adapted to segmentation tasks than other pooling functions. The method was evaluated on a traditional image segmentation task and on a dense labeling task carried out with a series of deep learning architectures in which the usual maximum pooling layers were altered to use the proposed pooling mechanism. Not only does it arbitrarily increase the receptive field in a parameterless fashion but it can better tolerate rotations since the pooling layers are independent of the geometric arrangement or sizes of the image regions. Different combinations of pooling operations produce images capable of emphasizing low/high frequencies, extract ultrametric contours, etc.
Electrical Power Diversification: An Approach Based on the Method of Maximum Entropy in the Mean
Authors: Bautista Rafael , Gzyl Henryk , ter Horst Enrique , Molina Germán
Published: February 2021

Electrical energy is generated in different ways, each located at some specific geographical area, and with different impact on the environment. Different sectors require heterogeneous rates of energy delivery, due to economic requirements. An important problem to solve is to determine how much energy must be sent from each supplier to satisfy each demand. Besides, the energy distribution process may have to satisfy ecological, technological, or economic cost constraints.
Attention Mechanisms and Their Applications to Complex Systems
Authors: Hernández Adrián , Amigó José M.
Published: February 2021

Deep learning models and graphics processing units have completely transformed the field of machine learning. Recurrent neural networks and long short-term memories have been successfully used to model and predict complex systems. However, these classic models do not perform sequential reasoning, a process that guides a task based on perception and memory. In recent years, attention mechanisms have emerged as a promising solution to these problems. In this review, we describe the key aspects of attention mechanisms and some relevant attention techniques and point out why they are a remarkable advance in machine learning. Then, we illustrate some important applications of these techniques in the modeling of complex systems.
Changing the Geometry of Representations: α-Embeddings for NLP Tasks
Authors: Volpi Riccardo , Thakur Uddhipan , Malagò Luigi
Published: February 2021

Word embeddings based on a conditional model are commonly used in Natural Language Processing (NLP) tasks to embed the words of a dictionary in a low dimensional linear space. Their computation is based on the maximization of the likelihood of a conditional probability distribution for each word of the dictionary. These distributions form a Riemannian statistical manifold, where word embeddings can be interpreted as vectors in the tangent space of a specific reference measure on the manifold. A novel family of word embeddings, called α-embeddings have been recently introduced as deriving from the geometrical deformation of the simplex of probabilities through a parameter α, using notions from Information Geometry. After introducing the α-embeddings, we show how the deformation of the simplex, controlled by α, provides an extra handle to increase the performances of several intrinsic and extrinsic tasks in NLP. We test the α-embeddings on different tasks with models of increasing complexity, showing that the advantages associated with the use of α-embeddings are present also for models with a large number of parameters. Finally, we show that tuning α allows for higher performances compared to the use of larger models in which additionally a transformation of the embeddings is learned during training, as experimentally verified in attention models.
Conditional Action and Imperfect Erasure of Qubits
Authors: Schmidt Heinz-Jürgen
Published: February 2021

We consider state changes in quantum theory due to “conditional action” and relate these to the discussion of entropy decrease due to interventions of “intelligent beings” and the principles of Szilard and Landauer/Bennett. The mathematical theory of conditional actions is a special case of the theory of “instruments”, which describes changes of state due to general measurements and will therefore be briefly outlined in the present paper. As a detailed example, we consider the imperfect erasure of a qubit that can also be viewed as a conditional action and will be realized by the coupling of a spin to another small spin system in its ground state.
Multi-Class Assessment Based on Random Forests
Authors: Berriri Mehdi , Djema Sofiane , Rey Gaëtan , Dartigues-Pallez Christel
Published: February 2021

Today, many students are moving towards higher education courses that do not suit them and end up failing. The purpose of this study is to help provide counselors with better knowledge so that they can offer future students courses corresponding to their profile. The second objective is to allow the teaching staff to propose training courses adapted to students by anticipating their possible difficulties. This is possible thanks to a machine learning algorithm called Random Forest, allowing for the classification of the students depending on their results. We had to process data, generate models using our algorithm, and cross the results obtained to have a better final prediction. We tested our method on different use cases, from two classes to five classes. These sets of classes represent the different intervals with an average ranging from 0 to 20. Thus, an accuracy of 75% was achieved with a set of five classes and up to 85% for sets of two and three classes.
A Study on the Radiated Susceptibility of Printed Circuit Boards and the Effects of Via Fencing
Authors: Tortorich Ryan P. , Morell William , Reiner Elizabeth , Bouillon William , Choi Jin-Woo
Published: February 2021

Because modern electronic systems are likely to be exposed to high intensity radiated fields (HIRF) environments, there is growing interest in understanding how electronic systems are affected by such environments. Backdoor coupling in particular is an area of concern for all electronics, but there is limited understanding about the mechanisms behind backdoor coupling. In this work, we present a study on printed circuit board (PCB) backdoor coupling and the effects of via fencing. Existing work focuses on ideal stackups and indicates that edge radiation is significantly reduced by via fencing. In this study, both full wave electromagnetic modeling and experimental verification are used to investigate both ideal and practical PCB stackups. In the ideal scenario, we find that via fencing substantially reduces coupling, which is consistent with prior work on emissions. In the practical scenario, we incorporate component footprints and traces which naturally introduce openings in the top ground plane. Both simulation and experimental data indicate that via fencing in the practical scenario does not substantially mitigate coupling, suggesting that PCB edge coupling is not the dominant coupling mechanism, even at varying angles of incidence and polarization.
An Adaptive Prediction Model for the Remaining Life of an Li-Ion Battery Based on the Fusion of the Two-Phase Wiener Process and an Extreme Learning Machine
Authors: Chen Xiaowu , Liu Zhen , Wang Jingyuan , Yang Chenglin , Long Bing , Zhou Xiuyun
Published: February 2021

Lithium-ion batteries (LiBs) are the most important part of electric vehicle (EV) systems. Because there are two different degradation rates during LiB degradation, there are many two-phase models for LiBs. However, most of these methods do not consider the randomness of the changing point in the two-phase model and cannot update the change time in real time. Therefore, this paper proposes a method based on the combination of the two-phase Wiener model and an extreme learning machine (ELM). The two-phase Wiener model is used to derive the mathematical expression of the remaining useful life (RUL), and the ELM is implemented to adaptively detect the changing point. Based on the Poisson distribution, the distribution of the changing time is derived as a gamma distribution. To evaluate the theoretical results and practicality of the proposed method, we perform both numerical and practical simulations. The results of the simulations show that due to the precise and adaptive detection of changing points, the proposed method produces a more accurate RUL prediction than existing methods. The error of our method for detecting the changing point is about 4% and the mean prediction error of RUL in the second phase is improved from 4.39 cycles to 1.61 cycles.
A Quad-Port Dual-Band MIMO Antenna Array for 5G Smartphone Applications
Authors: Huang Jianlin , Dong Guiting , Cai Jing , Li Han , Liu Gui
Published: February 2021

A quad-port antenna array operating in 3.5 GHz band (3.4–3.6 GHz) and 5 GHz band (4.8–5 GHz) for fifth-generation (5G) smartphone applications is presented in this paper. The single antenna element consists of an L-shaped strip, a parasitic rectangle strip, and a modified Z-shaped strip. To reserve space for 2G/3G/4G antennas, the quad-port antenna array is printed along the two long frames of the smartphone. The evolution design and the analysis of the optimal parameters of a single antenna element are derived to investigate the principle of the antenna. The prototype of the presented antenna is tested and the measured results agree well with the simulation. The measured total efficiency is better than 70% and the isolation is larger than 16.5 dB.
Research on Real-Time Infrared Image Fault Detection of Substation High-Voltage Lead Connectors Based on Improved YOLOv3 Network
Authors: Xu Qiwei , Huang Hong , Zhou Chuan , Zhang Xuefeng
Published: February 2021

Currently, infrared fault diagnosis mainly relies on manual inspection and low detection efficiency. This paper proposes an improved YOLOv3 network for detecting the working state of substation high-voltage lead connectors. Firstly, dilated convolution is introduced into the YOLOv3 backbone network to process low-resolution element layers, so as to enhance the network’s extraction of image features, promote function propagation and reuse, and improve the network’s recognition performance of small targets. Then the fault detection model of the infrared image of the high voltage lead connector is created and the optimal infrared image test data set is obtained through multi-scale training. Finally, the performance of the improved network model is tested on the data set. The test results show that the improved YOLOv3 network model has an average detection accuracy of 84.26% for infrared image faults of high-voltage lead connectors, which is 4.58% higher than the original YOLOv3 network model. The improved YOLOv3 network model has an average detection time of 0.308 s for infrared image faults of high-voltage lead connectors, which can be used for real-time detection in substations.
Characterization of Pore Structures and Implications for Flow Transport Property of Tight Reservoirs: A Case Study of the Lucaogou Formation, Jimsar Sag, Junggar Basin, Northwestern China
Authors: Su Yang , Zha Ming , Liu Keyu , Ding Xiujian , Qu Jiangxiu , Jin Jiehua
Published: February 2021

Quantitate characterization of pore structures is fundamental to elucidate fluid flow in the porous media. Pore structures of the Lucaogou Formation in the Jimsar Sag were investigated using petrography, mercury intrusion capillary porosimetry (MICP) and X-ray computed tomography (X-ray μ-CT). MICP analyses demonstrate that the pore topological structure is characterized by segmented fractal dimensions. Fractal dimension of small pores (r < Rapex) ranges from 2.05 to 2.37, whereas fractal dimension of large pores (r > Rapex) varies from 2.91 to 5.44, indicating that fractal theory is inappropriate for the topological characterization of large pores using MICP. Pore volume of tight reservoirs ranges over nine orders of magnitude (10−1–108 μm3), which follows a power-law distribution. Fractal dimensions of pores larger than a lower bound vary from 1.66 to 2.32. Their consistence with MICP results suggests that it is an appropriate indicator for the complex and heterogeneous pore network. Larger connected pores are primary conductive pathways regardless of lithologies. The storage capacity depends largely on pore complexity and heterogeneity, which is negatively correlated with fractal dimension of pore network. The less heterogeneous the pore network is, the higher storage capability it would have; however, the effect of pore network heterogeneity on the transport capability is much more complicated.
Performance Analysis of a Full Order Sensorless Control Adaptive Observer for Doubly-Fed Induction Generator in Grid Connected Operation
Authors: Brando Gianluca , Dannier Adolfo , Spina Ivan
Published: February 2021

This paper focuses on the performance analysis of a sensorless control for a Doubly Fed Induction Generator (DFIG) in grid-connected operation for turbine-based wind generation systems. With reference to a conventional stator flux based Field Oriented Control (FOC), a full-order adaptive observer is implemented and a criterion to calculate the observer gain matrix is provided. The observer provides the estimated stator flux and an estimation of the rotor position is also obtained through the measurements of stator and rotor phase currents. Due to parameter inaccuracy, the rotor position estimation is affected by an error. As a novelty of the discussed approach, the rotor position estimation error is considered as an additional machine parameter, and an error tracking procedure is envisioned in order to track the DFIG rotor position with better accuracy. In particular, an adaptive law based on the Lyapunov theory is implemented for the tracking of the rotor position estimation error, and a current injection strategy is developed in order to ensure the necessary tracking sensitivity around zero rotor voltages. The roughly evaluated rotor position can be corrected by means of the tracked rotor position estimation error, so that the corrected rotor position is sent to the FOC for the necessary rotating coordinate transformation. An extensive experimental analysis is carried out on an 11 kW, 4 poles, 400 V/50 Hz induction machine testifying the quality of the sensorless control.
Application of a New Dispatch Methodology to Identify the Influence of Inertia Supplying Wind Turbines on Day-Ahead Market Sales Volumes
Authors: Thiesen Henning , Jauch Clemens
Published: February 2021

Power system inertia is an essential part of grid frequency control. The number of synchronously connected machines, which inherently provide inertia, is decreasing due to the transition to renewable energies. Conventional generation units are being replaced by renewable generation units which are connected to the grid via frequency converters. Some power systems already suffer from too little power system inertia. Hence, inertia is a valuable yet non-traded commodity. A day-ahead dispatch methodology to secure power system inertia was developed and is applied and assessed in this work. Day-ahead market data of the combined market of the Republic of Ireland and Northern Ireland is used. If the superimposition of sell and buy bids results in insufficient inertia, the dispatch algorithm is applied. In decreasing price order, non-inertia-providing sell bids get replaced by the following sell bids in the merit order. The iterative process is repeated until sufficient inertia is in the system. The provision of synthetic inertia by wind turbines is considered in the process. The costs for additional stored kinetic energy for the assessed time periods and scenarios result in costs ranging from 1.02 to 4.49 EUR/kgm2.
Evaluating Spatial Interdependencies of Sector Coupling Using Spatiotemporal Modelling
Authors: Lichtenwoehrer Peter , Abart-Heriszt Lore , Kretschmer Florian , Suppan Franz , Stoeglehner Gernot , Neugebauer Georg
Published: February 2021

In light of global warming and the energy turn, sector coupling has gained increasing interest in recent years, from both the scientific community and politics. In the following article it is hypothesized that efficient multifaceted sector coupling solutions depend on detailed spatial and temporal characteristics of energy demand and supply. Hence, spatiotemporal modelling is used as a methodology of integrated spatial and energy planning, in order to determine favourable sector coupling strategies at the local level. A case study evaluation was carried out for both central and decentral renewable energy sources. Considering the high temporal resolutions of energy demand and supply, the results revealed a feasible operation of a district heating network in the central areas of the case study municipalities. Additionally, building integrated solar energy technologies are capable of providing large amount of excess energy that could serve other demand sectors, such as the mobility sector, or could be used for Power-to-X solutions. It is suggested that sector coupling strategies require spatial considerations and high temporal comparisons, in order to be reasonably integrated in spatial and urban planning.
Homeowners’ Willingness to Make Investment in Energy Efficiency Retrofit of Residential Buildings in China and Its Influencing Factors
Authors: Huang Ce , Ma Jiefang , Song Kun
Published: February 2021

In China, energy efficiency retrofit of residential buildings is entering a new stage in which homeowners are the main subject. In order to investigate homeowners’ willingness to invest and to analyze its influencing factors, interviews and a questionnaire survey were conducted in central Tianjin, China. The results show that homeowners have a certain willingness to invest in energy efficiency retrofit but that their willingness to pay (WTP) is far from enough to cover the total cost. Among the influencing factors, the homeowner’s age, education level, and retrofit experience as well as the age and floor area of their home are significantly related to their WTP. The reasons for the impact of these factors are further discussed, including the influences of China’s previous housing policies and retrofit policies. Policy recommendations to promote investment by homeowners are suggested based on the findings.
A Combined Approach for Model-Based PV Power Plant Failure Detection and Diagnostic
Authors: Gradwohl Christopher , Dimitrievska Vesna , Pittino Federico , Muehleisen Wolfgang , Montvay András , Langmayr Franz , Kienberger Thomas
Published: February 2021

Photovoltaic (PV) technology allows large-scale investments in a renewable power-generating system at a competitive levelized cost of electricity (LCOE) and with a low environmental impact. Large-scale PV installations operate in a highly competitive market environment where even small performance losses have a high impact on profit margins. Therefore, operation at maximum performance is the key for long-term profitability. This can be achieved by advanced performance monitoring and instant or gradual failure detection methodologies. We present in this paper a combined approach on model-based fault detection by means of physical and statistical models and failure diagnosis based on physics of failure. Both approaches contribute to optimized PV plant operation and maintenance based on typically available supervisory control and data acquisition (SCADA) data. The failure detection and diagnosis capabilities were demonstrated in a case study based on six years of SCADA data from a PV plant in Slovenia. In this case study, underperforming values of the inverters of the PV plant were reliably detected and possible root causes were identified. Our work has led us to conclude that the combined approach can contribute to an efficient and long-term operation of photovoltaic power plants with a maximum energy yield and can be applied to the monitoring of photovoltaic plants.