bluuebunny/crossref_metadata_2025 huggingface dataset:
Aspergillus Metabolome Database for Mass Spectrometry Metabolomics
Authors: Gil-de-la-Fuente Alberto , Mamani-Huanca Maricruz , Stroe María C. , Saugar Sergio , Garcia-Alvarez Alejandra , Brakhage Axel A. , Barbas Coral , Otero Abraham
Published: May 2021

The Aspergillus Metabolome Database is a free online resource to perform metabolite annotation in mass spectrometry studies devoted to the genus Aspergillus. The database was created by retrieving and curating information on 2811 compounds present in 601 different species and subspecies of the genus Aspergillus. A total of 1514 scientific journals where these metabolites are mentioned were added as meta-information linked to their respective compounds in the database. A web service to query the database based on m/z (mass/charge ratio) searches was added to CEU Mass Mediator; these queries can be performed over the Aspergillus database only, or they can also include a user-selectable set of other general metabolomic databases. This functionality is offered via web applications and via RESTful services. Furthermore, the complete content of the database has been made available in .csv files and as a MySQL database to facilitate its integration into third-party tools. To the best of our knowledge, this is the first database and the first service specifically devoted to Aspergillus metabolite annotation based on m/z searches.
Influenza- and COVID-19-Associated Pulmonary Aspergillosis: Are the Pictures Different?
Authors: Reizine Florian , Pinceaux Kieran , Lederlin Mathieu , Autier Brice , Guegan Hélène , Gacouin Arnaud , Luque-Paz David , Boglione-Kerrien Christelle , Bacle Astrid , Le Daré Brendan , Launey Yoann , Lesouhaitier Mathieu , Painvin Benoit , Camus Christophe , Mansour Alexandre , Robert-Gangneux Florence , Belaz Sorya , Le Tulzo Yves , Tadié Jean-Marc , Maamar Adel , Gangneux Jean-Pierre
Published: May 2021

Invasive pulmonary aspergillosis (IPA) in intensive care unit patients is a major concern. Influenza-associated acute respiratory distress syndrome (ARDS) and severe COVID-19 patients are both at risk of developing invasive fungal diseases. We used the new international definitions of influenza-associated pulmonary aspergillosis (IAPA) and COVID-19-associated pulmonary aspergillosis (CAPA) to compare the demographic, clinical, biological, and radiological aspects of IAPA and CAPA in a monocentric retrospective study. A total of 120 patients were included, 71 with influenza and 49 with COVID-19-associated ARDS. Among them, 27 fulfilled the newly published criteria of IPA: 17/71 IAPA (23.9%) and 10/49 CAPA (20.4%). Kaplan–Meier curves showed significantly higher 90-day mortality for IPA patients overall (p = 0.032), whereas mortality did not differ between CAPA and IAPA patients. Radiological findings showed differences between IAPA and CAPA, with a higher proportion of features suggestive of IPA during IAPA. Lastly, a wide proportion of IPA patients had low plasma voriconazole concentrations with a higher delay to reach concentrations > 2 mg/L in CAPA vs. IAPA patients (p = 0.045). Severe COVID-19 and influenza patients appeared very similar in terms of prevalence of IPA and outcome. The dramatic consequences on the patients’ prognosis emphasize the need for a better awareness in these particular populations.
Alteration of White Matter in Patients with Central Post-Stroke Pain
Authors: Park Jung Geun , Hong Bo Young , Park Hae-Yeon , Yoo Yeun Jie , Yoon Mi-Jeong , Kim Joon-Sung , Lim Seong Hoon
Published: May 2021

A stroke may be followed by central post-stroke pain (CPSP), which is characterized by chronic neuropathic pain. The exact mechanism has not yet been fully uncovered. We investigated alterations in the white matters in patients with CPSP, compared with stroke patients without CPSP and normal controls. Our retrospective cross-sectional, case-control study participants were assigned to three groups: CPSP (stroke patients with CPSP (n = 17)); stroke control (stroke patients without CPSP (n = 26)); and normal control (normal subjects (n = 34)). The investigation of white matter for CPSP was focused on the values of fiber numbers (FN) and fractional anisotrophy (FA) for spinothalamic tract (STT), anterior thalamic radiation (ATR), superior thalamic radiation (STR) and posterior thalamic radiation (PTR), and corticospinal tract (CST) was measured. The FA for the STT and STR of the CPSP group were lower than those for the stroke control and normal control groups. The FA of CST and ATR did not differ between the CPSP and stroke groups, but both differed from the normal control. The FA of PTR in the stroke control group differed from the normal control group, but not from the CPSP group. The FN of CST, STT, ATR, and STR for the CPSP and stroke control groups did not differ from each other, but both differed from those of normal controls. FN of PTR did not differ between the CPSP and normal control groups. The alterations in the spinothalamic tract and superior thalamic radiation after stroke would play a role in the pathogenesis of CPSP.
Fertility, Pregnancy and Lactation Considerations for Women with CF in the CFTR Modulator Era
Authors: Jain Raksha , Taylor-Cousar Jennifer L.
Published: May 2021

Cystic fibrosis (CF) is an autosomal recessive genetic disorder impacting approximately 80,000 people of all races and ethnicities world-wide. CF is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene which encodes a protein of the same name. Protein dysfunction results in abnormal chloride and bicarbonate transport in mucus membranes, including those in the respiratory, gastrointestinal and reproductive tracts. Abnormal anion transport causes viscous secretions at the site of involvement. The majority of people with CF succumb to respiratory failure following recurrent cycles of infection and inflammation in the airways. Historically, providers treated the signs and symptoms of CF, but since 2012, have been able to impact the basic defect for the subset of people with CF who have mutations that respond to the new class of drugs, CFTR protein modulators. With the improved health and longevity afforded by CFTR modulators, more women are interested in parenthood and are becoming pregnant. Furthermore, this class of drugs likely increases fertility in women with CF. However, the safety of CFTR modulators in pregnancy and lactation is only beginning to be established. We summarize available data on the impact of CFTR modulators on fertility, pregnancy and lactation in women with CF.
Three-Year Follow-Up of Laser In Situ Keratomileusis Treatments for Myopia: Multi-Center Cohort Study in Korean Population
Authors: Kim Jae-Yong , Lee Hun , Joo Choun-Ki , Hyon Joon-Young , Kim Tae-Im , Kim Jin-Hyoung , Kim Jin-Kuk , Cho Eun-Young , Choi Ji-Eun , Lee Na-Rae , Tchah Hung-Won
Published: May 2021

This multi-center cohort study included 3401 myopic laser in situ keratomileusis (LASIK) procedures conducted in 1756 myopia patients between 2002 and 2005. Pre- and postoperative uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and manifest refraction spherical equivalent (SE) were recorded. Factors predicting low postoperative efficacy (defined as a postoperative UCVA < 0.5) were identified using univariate and multivariate logistic regression analysis. Compared with 1 month postoperatively, logMAR UCVA at 3 months postoperatively was significantly decreased (p = 0.002) and that at 2 and 3 years was significantly increased (p < 0.001). LogMAR BCVA at 2 years postoperatively was significantly decreased compared with 1 month postoperatively (p = 0.008). Over the 3-year postoperative period, overall refractive predictability within ±1.00 D and ±0.50 D ranged from 69.0% to 86.2% and from 43.3% to 67.8%, respectively. This also decreased from 1 month to 6 months postoperatively (p < 0.005). Multivariate logistic regression analysis using generalized estimating equations, revealed that higher preoperative SE (odds ratio [OR], 2.58 and 7.23; p < 0.001) and lower preoperative BCVA (OR, 2.44; p = 0.003) were predictive of a low postoperative efficacy. In summary, myopic LASIK can be effective and safe with a high refractive predictability in a Korean population, but myopic regression occurs over time. Higher preoperative SE and lower preoperative BCVA are predictive of a low postoperative efficacy.
Lincp21-RNA as Predictive Response Marker for Preoperative Chemoradiotherapy in Rectal Cancer
Authors: Benitez Jose Carlos , Campayo Marc , Díaz Tania , Ferrer Carme , Acosta-Plasencia Melissa , Monzo Mariano , Cirera Luis , Besse Benjamin , Navarro Alfons
Published: May 2021

Preoperative chemoradiotherapy (CRT) is a standard treatment for locally advanced rectal cancer (RC) patients, but its use in non-responders can be associated with increased toxicities and resection delay. LincRNA-p21 is a long non-coding RNA involved in the p53 pathway and angiogenesis regulation. We aimed to study whether lincRNA-p21 expression levels can act as a predictive biomarker for neoadjuvant CRT response. We analyzed RNAs from pretreatment biopsies from 70 RC patients treated with preoperative CRT. Pathological response was classified according to the tumor regression grade (TRG) Dworak classification. LincRNA-p21 expression was determined by RTqPCR. The results showed that lincRNA-p21 was upregulated in stage III tumors (p = 0.007) and in tumors with the worst response regarding TRG (p = 0.027) and downstaging (p = 0.016). ROC curve analysis showed that lincRNA-p21 expression had the capacity to distinguish a complete response from others (AUC:0.696; p = 0.014). LincRNA-p21 was shown as an independent marker of preoperative CRT response (p = 0.047) and for time to relapse (TTR) (p = 0.048). In conclusion, lincRNA-p21 is a marker of advanced disease, worse response to neoadjuvant CRT, and shorter TTR in locally advanced RC patients. The study of lincRNA-p21 may be of value in the individualization of pre-operative CRT in RC.
Influence of a Rejuvenator on Homogenization of an Asphalt Mixture with Increased Content of Reclaimed Asphalt Pavement in Lowered Technological Temperatures
Authors: Slabonski Pawel , Stankiewicz Beata , Beben Damian
Published: May 2021

The most technologically advanced form of road construction uses a high content of reclaimed asphalt pavement (RAP) as a component of its asphalt mixture (AM). However, there is a real problem with the effective interaction of RAP and MA. The research herein described presents an effective use of RAP originating from the recycling process of old pavements thanks to the application of an original rejuvenator. Two types of AM were designed concerning the base course of pavement as well as the wearing course and the binder course for various traffic categories. The achieved results show that the rejuvenator improved the homogenization of RAP with the asphalt binder and aggregate in each mixture type. On the basis of the research, the possibility of using paving AM with an increased content of RAP in lowered technological temperatures received a favorable assessment. Mixtures of asphalt concrete containing 40% RAP meet both Polish and German requirements for mixtures intended for heavy traffic pavements. Thanks to use of the rejuvenator, it is possible to compact AM layers containing RAP in a final compaction temperature lowered by about 20 °C. The achieved AM lab test results were confirmed on trial road sections. The rejuvenator used in tested AMs improved the homogenization of RAP with both binder and virgin aggregate. Moreover, the study proved that it is possible to use 20%, 40%, and even 100% RAP contents in the mixtures thanks to the use of the rejuvenator based on plant resin and the creation of conditions enabling the effective homogenization of AM components.
Modeling of Friction Phenomena of Ti-6Al-4V Sheets Based on Backward Elimination Regression and Multi-Layer Artificial Neural Networks
Authors: Trzepieciński Tomasz , Szpunar Marcin , Kaščák Ľuboš
Published: May 2021

This paper presents the application of multi-layer artificial neural networks (ANNs) and backward elimination regression for the prediction of values of the coefficient of friction (COF) of Ti-6Al-4V titanium alloy sheets. The results of the strip drawing test were used as data for the training networks. The strip drawing test was carried out under conditions of variable load and variable friction. Selected types of synthetic oils and environmentally friendly bio-degradable lubricants were used in the tests. ANN models were conducted for different network architectures and training methods: the quasi-Newton, Levenberg-Marquardt and back propagation. The values of root mean square (RMS) error and determination coefficient were adopted as evaluation criteria for ANNs. The minimum value of the RMS error for the training set (RMS = 0.0982) and the validation set (RMS = 0.1493) with the highest value of correlation coefficient (R2 = 0.91) was observed for a multi-layer network with eight neurons in the hidden layer trained using the quasi-Newton algorithm. As a result of the non-linear relationship between clamping and friction force, the value of the COF decreased with increasing load. The regression model F-value of 22.13 implies that the model with R2 = 0.6975 is significant. There is only a 0.01% chance that an F-value this large could occur due to noise.
The Application of Convolutional Neural Networks (CNNs) to Recognize Defects in 3D-Printed Parts
Authors: Wen Hao , Huang Chang , Guo Shengmin
Published: May 2021

Cracks and pores are two common defects in metallic additive manufacturing (AM) parts. In this paper, deep learning-based image analysis is performed for defect (cracks and pores) classification/detection based on SEM images of metallic AM parts. Three different levels of complexities, namely, defect classification, defect detection and defect image segmentation, are successfully achieved using a simple CNN model, the YOLOv4 model and the Detectron2 object detection library, respectively. The tuned CNN model can classify any single defect as either a crack or pore at almost 100% accuracy. The other two models can identify more than 90% of the cracks and pores in the testing images. In addition to the application of static image analysis, defect detection is also successfully applied on a video which mimics the AM process control images. The trained Detectron2 model can identify almost all the pores and cracks that exist in the original video. This study lays a foundation for future in situ process monitoring of the 3D printing process.
Micron-Sized Monodisperse Particle LiNi0.6Co0.2Mn0.2O2 Derived by Oxalate Solvothermal Process Combined with Calcination as Cathode Material for Lithium-Ion Batteries
Authors: Chen Zhuo , Guo Fangya , Zhang Youxiang
Published: May 2021

Ni-rich cathode LiNixCoyMn1-x-yO2 (NCM, x ≥ 0.5) materials are promising cathodes for lithium-ion batteries due to their high energy density and low cost. However, several issues, such as their complex preparation and electrochemical instability have hindered their commercial application. Herein, a simple solvothermal method combined with calcination was employed to synthesize LiNi0.6Co0.2Mn0.2O2 with micron-sized monodisperse particles, and the influence of the sintering temperature on the structures, morphologies, and electrochemical properties was investigated. The material sintered at 800 °C formed micron-sized particles with monodisperse characteristics, and a well-order layered structure. When charged–discharged in the voltage range of 2.8–4.3 V, it delivered an initial discharge capacity of 175.5 mAh g−1 with a Coulombic efficiency of 80.3% at 0.1 C, and a superior discharge capacity of 135.4 mAh g−1 with a capacity retention of 84.4% after 100 cycles at 1 C. The reliable electrochemical performance is probably attributable to the micron-sized monodisperse particles, which ensured stable crystal structure and fewer side reactions. This work is expected to provide a facile approach to preparing monodisperse particles of different scales, and improve the performance of Ni-rich NCM or other cathode materials for lithium-ion batteries.
Scaling Concepts in Serpin Polymer Physics
Authors: Raccosta Samuele , Librizzi Fabio , Jagger Alistair M. , Noto Rosina , Martorana Vincenzo , Lomas David A. , Irving James A. , Manno Mauro
Published: May 2021

α1-Antitrypsin is a protease inhibitor belonging to the serpin family. Serpin polymerisation is at the core of a class of genetic conformational diseases called serpinopathies. These polymers are known to be unbranched, flexible, and heterogeneous in size with a beads-on-a-string appearance viewed by negative stain electron microscopy. Here, we use atomic force microscopy and time-lapse dynamic light scattering to measure polymer size and shape for wild-type (M) and Glu342→Lys (Z) α1-antitrypsin, the most common variant that leads to severe pathological deficiency. Our data for small polymers deposited onto mica and in solution reveal a power law relation between the polymer size, namely the end-to-end distance or the hydrodynamic radius, and the polymer mass, proportional to the contour length. We use the scaling concepts of polymer physics to assess that α1-antitrypsin polymers are random linear chains with a low persistence length.
Apical Pressure Generated Using Conventional Syringe Irrigation in Immature Teeth—An In Vitro Study
Authors: Jäggi Marco , Magni Eva , Eggmann Florin , ElAyouti Ashraf , Connert Thomas , Weiger Roland
Published: May 2021

This in vitro study aimed to evaluate apical pressure during irrigant delivery with syringe irrigation in immature teeth with an open apical foramen. Conventional syringe irrigation was performed in a 3D-printed immature incisor. A 5 mL syringe combined with 25 G and 30 G cannulas was used. Open-ended and side-vented needle tip designs were assessed. Cannulas were placed at tooth length (TL), TL −1 mm, TL −2 mm, and TL −4 mm. The syringe plunger was moved with a force of 10 N, 20 N, 40 N, and 80 N to simulate clinical conditions. A pressure sensor measured periapical pressures during irrigation. Each experiment was repeated 10 times. Data were analyzed descriptively (maximum, mean, standard deviation, 95% CI) with the critical threshold indicative of extrusion set at 7.64 mbar. 30 G cannulas with both needle tip designs never exceeded the threshold at any TL with a plunger force of 10–40 N. At 80 N, 30 G open-ended cannulas exceeded the threshold in 10%, 30 G side-vented in 20–60% of the measurements. At any TL, 25 G open-ended cannulas and 25 G side-vented cannulas never crossed the threshold with forces of 10–20 N and 10 N, respectively. Consequently, 30 G cannulas with both designs can be recommended for irrigant delivery in immature teeth. 25 G cannulas ought to be used with caution.
Optimized Microstructure and Improved Magnetic Properties of Pr-Dy-Al-Ga Diffused Sintered Nd-Fe-B Magnets
Authors: Qu Pengpeng , Li Feifei , Rehman Sajjad Ur , He Lei , Yu Xiaoqiang , Huang Qingfang , Yang Munan , Li Jiajie
Published: May 2021

The grain boundary diffusion process (GBDP) has become an important technique in improving the coercivity and thermal stability of Dy-free sintered Nd-Fe-B magnets. The influence of Dy70Al10Ga20 and (Pr75Dy25)70Al10Ga20 alloys by the GBDP on sintered Nd-Fe-B magnets are investigated in this paper. After diffusing Dy70Al10Ga20 and (Pr75Dy25)70Al10Ga20 alloys, the coercivity (Hcj) of the magnets increased from 13.58 kOe to 20.10 kOe and 18.11 kOe, respectively. Meanwhile, the remanence of the magnets decreased slightly. The thermal stability of the diffused magnets was improved by the GBDP. The microstructure shows continuous Rare-earth-rich (RE-rich) grain boundary phases and (Dy, Pr/Nd)2Fe14B core-shell structures which contribute to improving the coercivity. Moreover, the Dy concentration on the surface of the (Pr75Dy25)70Al10Ga20 diffused magnets decreased with the Pr substitution for the Dy element. The openness of the recoil loops for the (Pr75Dy25)70Al10Ga20 diffused magnets is smaller than that of the original magnets and Dy70Al10Ga20 diffused magnets. The results show that the (Pr75Dy25)70Al10Ga20 alloys can effectively optimize the microstructure and improve the magnetic properties and thermal stability of the sintered Nd-Fe-B magnets.
Research Progress of Proton Exchange Membrane Failure and Mitigation Strategies
Authors: Xing Yijing , Li Haibin , Avgouropoulos George
Published: May 2021

Proton exchange membrane (PEM) is critical for the efficient, reliable and safe operation of proton exchange membrane fuel cells (PEMFC). The lifetime of PEM is the main factor restricting the commercialization of PEMFC. The complexity of operating conditions, such as open-circuit/idling, dynamic load and startup-shutdown under automotive conditions, on PEMFC will cause the mechanical and chemical degradation of PEM and affect the service life of PEMFC. In order to understand the degradation behavior and durability of PEM, this paper presents an overview of the degradation failure mechanism and mitigation strategies of PEM. The mechanical and chemical degradation behavior of PEM and its causes, as well as the mitigation strategies are discussed in order to give a direction for PEM design and fuel cell system control strategy. It is proposed as a primary principle in order to further develop and promote the durability of PEM, to focus on the material improvement and system engineering.
A Fully Coupled Simulation of Planar Deposition Flow and Fiber Orientation in Polymer Composites Additive Manufacturing
Authors: Wang Zhaogui , Smith Douglas E.
Published: May 2021

Numerical studies for polymer composites deposition additive manufacturing have provided significant insight promoting the rapid development of the technology. However, little of existing literature addresses the complex yet important polymer composite melt flow–fiber orientation coupling during deposition. This paper explores the effect of flow–fiber interaction for polymer deposition of 13 wt.% Carbon Fiber filled Acrylonitrile Butadiene Styrene (CF/ABS) composites through a finite-element-based numerical approach. The molten composite flow in the extrusion die plus a strand of the deposited bead contacting the deposition substrate is modelled using a 2D isothermal and incompressible Newtonian planar flow model, where the material deposition rate is ~110 mm/s simulating a large scale additive manufacturing process. The Folgar–Tucker model associated with the Advani–Tucker orientation tensor approach is adopted for the evaluation of the fiber orientation state, where the orthotropic fitted closure is applied. By comparing the computed results between the uncoupled and fully coupled solutions, it is found that the flow-orientation effects are mostly seen in the nozzle convergence zone and the extrusion-deposition transition zone of the flow domain. Further, the fully coupled fiber orientation solution is highly sensitive to the choice of the fiber–fiber interaction coefficient CI, e.g., assigning CI as 0.01 and 0.001 results in a 23% partial relative difference in the predicted elastic modulus along deposition direction. In addition, Structural properties of deposited CF/ABS beads based on our predicted fiber orientation results show favorable agreements with related experimental studies.
Investigation of Compression and Buckling Properties of a Novel Surface-Based Lattice Structure Manufactured Using Multi Jet Fusion Technology
Authors: Nazir Aamer , Ali Mubasher , Jeng Jeng-Ywan
Published: May 2021

Lattice structures possess many superior properties over solid materials and conventional structures. Application-oriented lattice structure designs have become a choice in many industries, such as aerospace, automotive applications, construction, biomedical applications, and footwear. However, numerical and empirical analyses are required to predict mechanical behavior under different boundary conditions. In this article, a novel surface-based structure named O-surface structure is designed and inspired by existing Triply Periodic Minimal Surface morphologies in a particular sea urchin structure. For comparison, both structures were designed with two different height configurations and investigated for mechanical performance in terms of compression, local buckling, global buckling, and post-buckling behavior. Both simulation and experimental methods were carried out to reveal these aforementioned properties of samples fabricated by multi jet fusion technology. The sea urchin structure exhibited better mechanical strength than its counterpart, with the same relative density almost two-folds higher in the compressive response. However, the O-surface structure recorded more excellent energy absorption and flexible behavior under compression. Additionally, the compression behavior of the O-surface structure was progressive from top to bottom. In contrast, the sea urchin structure was collapsed randomly due to originated cracks from unit cells’ centers with local buckling effects. Moreover, the buckling direction of structures in long columns was also affected by keeping the relative density constant. Finally, based on specific strength, the O-surface structure exhibited 16-folds higher specific strength than the sea urchin structure.
Advances in Natural Fibers and Polymers
Authors: Espinach Francesc X.
Published: May 2021

The use of natural fibers as reinforcement for polymer-based composites has been attracting the interest of the scientific community for a long time [...]
Lightweight Vapor-Permeable Plasters for Building Repair Detailed Experimental Analysis of the Functional Properties
Authors: Záleská Martina , Pavlíková Milena , Pivák Adam , Lauermannová Anna-Marie , Jankovský Ondřej , Pavlík Zbyšek
Published: May 2021

Three types of lightweight plasters for building repair were prepared and tested. The composition of plasters was designed in respect to their compatibility with materials used in the past in historical masonry. For the hardened plasters, detailed testing of microstructural and macrostructural parameters was realized together with the broad experimental campaign focused on the assessment of mechanical, hygric, and thermal properties. As the researched plasters should find use in salt-laden masonry, specific attention was paid to the testing of their durability against salt crystallization. The mechanical resistance, porosity, water vapor transmission properties, and water transport parameters of all the researched plasters safely met criteria of WTA directive 2-9-04/D and standard EN 998-1 imposed on repair mortars. Moreover, the tested materials were ranked as lightweight plasters and due to their low thermal conductivity they can be used for the improvement of thermal performance of repaired masonry. The salt crystallization test caused little or no damage of the plasters, which was due to their high porosity that provided free space for salt crystallization. The developed plasters can be recommended for application in repair of damp and salt masonry and due to their compatible composition also in historical, culture heritage buildings. The added value of plasters is also their good thermal insulation performance.
Hexagonal-Shaped Spin Crossover Nanoparticles Studied by Ising-Like Model Solved by Local Mean Field Approximation
Authors: Cazelles Catherine , Linares Jorge , Ndiaye Mamadou , Dahoo Pierre-Richard , Boukheddaden Kamel
Published: May 2021

The properties of spin crossover (SCO) nanoparticles were studied for five 2D hexagonal lattice structures of increasing sizes embedded in a matrix, thus affecting the thermal properties of the SCO region. These effects were modeled using the Ising-like model in the framework of local mean field approximation (LMFA). The systematic combined effect of the different types of couplings, consisting of (i) bulk short- and long-range interactions and (ii) edge and corner interactions at the surface mediated by the matrix environment, were investigated by using parameter values typical of SCO complexes. Gradual two and three hysteretic transition curves from the LS to HS states were obtained. The results were interpreted in terms of the competition between the structure-dependent order and disorder temperatures (TO.D.) of internal coupling origin and the ligand field-dependent equilibrium temperatures (Teq) of external origin.
Development and Application of a Multi-Objective Tool for Thermal Design of Heat Exchangers Using Neural Networks
Authors: de Andrés Honrubia José Luis , de la Puerta José Gaviria , Cortés Fernando , Aguirre-Larracoechea Urko , Goti Aitor , Retolaza Jone
Published: May 2021

This paper presents the design of a multi-objective tool for sizing shell and tube heat exchangers (STHX), developed under a University/Industry collaboration. This work aims to show the feasibility of implementing artificial intelligence tools during the design of Heat Exchangers in industry. The design of STHX optimisation tools using artificial intelligence algorithms is a visited topic in the literature, nevertheless, the degree of implementation of this concept is uncommon in industrial companies. Thus, the challenge of this research consists of the development of a tool for the design of STHX using artificial intelligence algorithms that can be used by industrial companies. The approach is implemented using a simulated dataset contrasted with ARA TT, the company taking part in the project. The given dataset to develop a theoretical STHX calculator was modeled using MATLAB. This dataset was used to train seven neural networks (NNs). Three of them were mono-objective, one per objective to predict, and four were multi-objective. The last multi-objective NN was used to develop an inverse neural network (INN), which is used to find the optimal configuration of the STHXs. In this specific case, three design parameters, the pressure drop on the shell side, the pressure drop on the tube side and heat transfer rate, were jointly and successfully optimised. As a conclusion, this work proves that the developed tool is valid in both terms of effectiveness and user-friendliness for companies like ARA TT to improve their business activity.
Hybrid Model for Time Series of Complex Structure with ARIMA Components
Authors: Mandrikova Oksana , Fetisova Nadezhda , Polozov Yuriy
Published: May 2021

A hybrid model for the time series of complex structure (HMTS) was proposed. It is based on the combination of function expansions in a wavelet series with ARIMA models. HMTS has regular and anomalous components. The time series components, obtained after expansion, have a simpler structure that makes it possible to identify the ARIMA model if the components are stationary. This allows us to obtain a more accurate ARIMA model for a time series of complicated structure and to extend the area for application. To identify the HMTS anomalous component, threshold functions are applied. This paper describes a technique to identify HMTS and proposes operations to detect anomalies. With the example of an ionospheric parameter time series, we show the HMTS efficiency, describe the results and their application in detecting ionospheric anomalies. The HMTS was compared with the nonlinear autoregression neural network NARX, which confirmed HMTS efficiency.
Integral Models Based on Volterra Equations with Prehistory and Their Applications in Energy
Authors: Markova Evgeniia , Sidler Inna , Solodusha Svetlana
Published: May 2021

The paper addresses the application of Volterra integral equations of the first kind for modeling dynamic power systems. We study the problem of forecasting the commissioning of capacities of the electric power system, taking into account various hypotheses about the dynamics of equipment aging, and the known prehistory. The numerical results of the application of two models to the problem of the development of a large electric power system using the example of the Unified Energy System of Russia are presented. Theoretical results were formulated for a two-dimensional Volterra integral equation of the first kind with variable limits of integration. This class of equations arises when solving the actual problem of identifying variable characteristics of a nonlinear dynamic system of the “input-output” type.
LMI-Observer-Based Stabilizer for Chaotic Systems in the Existence of a Nonlinear Function and Perturbation
Authors: Karami Hamede , Mobayen Saleh , Lashkari Marzieh , Bayat Farhad , Chang Arthur
Published: May 2021

In this study, the observer-based state feedback stabilizer design for a class of chaotic systems in the existence of external perturbations and Lipchitz nonlinearities is presented. This manuscript aims to design a state feedback controller based on a state observer by the linear matrix inequality method. The conditions of linear matrix inequality guarantee the asymptotical stability of the system based on the Lyapunov theorem. The stabilizer and observer parameters are obtained using linear matrix inequalities, which make the state errors converge to the origin. The effects of the nonlinear Lipschitz perturbation and external disturbances on the system stability are then reduced. Moreover, the stabilizer and observer design techniques are investigated for the nonlinear systems with an output nonlinear function. The main advantages of the suggested approach are the convergence of estimation errors to zero, the Lyapunov stability of the closed-loop system and the elimination of the effects of perturbation and nonlinearities. Furthermore, numerical examples are used to illustrate the accuracy and reliability of the proposed approaches.
Long Text QA Matching Model Based on BiGRU–DAttention–DSSM
Authors: Chen Shihong , Xu Tianjiao
Published: May 2021

QA matching is a very important task in natural language processing, but current research on text matching focuses more on short text matching rather than long text matching. Compared with short text matching, long text matching is rich in information, but distracting information is frequent. This paper extracted question-and-answer pairs about psychological counseling to research long text QA-matching technology based on deep learning. We adjusted DSSM (Deep Structured Semantic Model) to make it suitable for the QA-matching task. Moreover, for better extraction of long text features, we also improved DSSM by enriching the text representation layer, using a bidirectional neural network and attention mechanism. The experimental results show that BiGRU–Dattention–DSSM performs better at matching questions and answers.
From Benign Inflammatory Dermatosis to Cutaneous Lymphoma. DNA Copy Number Imbalances in Mycosis Fungoides versus Large Plaque Parapsoriasis
Authors: Gug Georgiana , Solovan Caius
Published: May 2021

Background and Objectives: Mycosis fungoides (MF) and large plaque parapsoriasis (LPP) evolution provide intriguing data and are the cause of numerous debates. The diagnosis of MF and LPP is associated with confusion and imprecise definition. Copy number alterations (CNAs) may play an essential role in the genesis of cancer out of genes expression dysregulation. Objectives: Due to the heterogeneity of MF and LPP and the scarcity of the cases, there are an exceedingly small number of studies that have identified molecular changes in these pathologies. We aim to identify and compare DNA copy number alterations and gene expression changes between MF and LPP to highlight the similarities and the differences between these pathologies. Materials and Methods: The patients were prospectively selected from University Clinic of Dermatology and Venereology Timișoara, Romania. From fresh frozen skin biopsies, we extracted DNA using single nucleotide polymorphism (SNP) data. The use of SNP array for copy number profiling is a promising approach for genome-wide analysis. Results: After reviewing each group, we observed that the histograms generated for chromosome 1–22 were remarkably similar and had a lot of CNAs in common, but also significant differences were seen. Conclusions: This study took a step forward in finding out the differences and similarities between MF and LPP, for a more specific and implicitly correct approach of the case. The similarity between these two pathologies in terms of CNAs is striking, emphasizing once again the difficulty of approaching and differentiating them.
Electrocardiographic Abnormalities and Mortality in Epilepsy Patients
Authors: Suna Normunds , Suna Inga , Gutmane Evija , Kande Linda , Karelis Guntis , Viksna Ludmila , Folkmanis Valdis
Published: May 2021

Background and Objectives: People with epilepsy (PWE) have a 2–3 times higher mortality rate than the general population. Sudden unexpected death in epilepsy (SUDEP) comprises a significant proportion of premature deaths, whereas sudden cardiac death (SCD) is among the leading causes of sudden death in the general population. Cardiac pathologies are significantly more prevalent in PWE. Whether electrocardiographic (ECG) parameters are associated with remote death in PWE has yet to be elucidated. The study objective was to assess whether interictal ECG parameters are associated with mortality in the long-term. Materials and Methods: The study involved 471 epilepsy patients who were hospitalized after a bilateral tonic-clonic seizure(s). ECG parameters were obtained on the day of hospitalization (heart rate, PQ interval, QRS complex, QT interval, heart rate corrected QT interval (QTc), ST segment and T wave changes), as well as reported ECG abnormalities. Mortality data were obtained from the Latvian National Cause-of-Death database 3–11, mean 7.0 years after hospitalization. The association between the ECG parameters and the long-term clinical outcome were examined. Results: At the time of assessment, 75.4% of patients were alive and 24.6% were deceased. Short QTc interval (odds ratio (OR) 4.780; 95% confidence interval (CI) 1.668–13.698; p = 0.004) was associated with a remote death. After the exclusion of known comorbidities with high mortality rates, short QTc (OR 4.631) and ECG signs of left ventricular hypertrophy (OR 5.009) were associated with a remote death. Conclusions: The association between routine 12-lead rest ECG parameters—short QTc interval and a pattern of left ventricular hypertrophy—and remote death in epilepsy patients was found. To the best of our knowledge, this is the first study to associate rest ECG parameters with remote death in an epileptic population.
GERD after Bariatric Surgery. Can We Expect Endoscopic Findings?
Authors: Vilallonga Ramon , Sanchez-Cordero Sergi , Umpiérrez Mayor Nicolas , Molina Alicia , Cirera de Tudela Arturo , Ruiz-Úcar Elena , Carrasco Manel Armengol
Published: May 2021

Background and Objectives: Bariatric surgery remains the gold standard treatment for morbidly obese patients. Roux-en-y gastric bypass and laparoscopic sleeve gastrectomy are the most frequently performed surgeries worldwide. Obesity has also been related to gastroesophageal reflux disease (GERD). The management of a preoperative diagnosis of GERD, with/without hiatal hernia before bariatric surgery, is mandatory. Endoscopy can show abnormal findings that might influence the final type of surgery. The aim of this article is to discuss and review the evidence related to the endoscopic findings after bariatric surgery. Materials and Methods: A systematic review of the literature has been conducted, including all recent articles related to endoscopic findings after bariatric surgery. Our review of the literature has included 140 articles, of which, after final review, only eight were included. The polled articles included discussion of the endoscopy findings after roux-en-y gastric bypass and laparoscopic sleeve gastrectomy. Results: We found that the specific care of bariatric patients might include an endoscopic diagnosis when GERD symptoms are present. Conclusions: Recent evidence has shown that endoscopic follow-up after laparoscopic sleeve gastrectomy could be advisable, due to the pathological findings in endoscopic procedures in asymptomatic patients.
Biomarkers Associated with Mortality in Aortic Stenosis: A Systematic Review and Meta-Analysis
Authors: White Madeline , Baral Ranu , Ryding Alisdair , Tsampasian Vasiliki , Ravindrarajah Thuwarahan , Garg Pankaj , Koskinas Konstantinos C. , Clark Allan , Vassiliou Vassilios S.
Published: May 2021

The optimal timing of aortic valve replacement (AVR) remains controversial. Several biomarkers reflect the underlying pathophysiological processes in aortic stenosis (AS) and may be of use as mortality predictors. The aim of this systematic review and meta-analysis is to evaluate the blood biomarkers utilised in AS and assess whether they associate with mortality. PubMed and Embase were searched for studies reporting baseline biomarker level and mortality outcomes in patients with AS. A total of 83 studies met the inclusion criteria and were systematically reviewed. Of these, 21 reporting brain natriuretic peptide (BNP), N-terminal pro B-type natriuretic peptide (NT-proBNP), Troponin and Galectin-3 were meta-analysed. Pooled analysis demonstrated that all-cause mortality was significantly associated with elevated baseline levels of BNP (HR 2.59; 95% CI 1.95–3.44; p < 0.00001), NT-proBNP (HR 1.73; 95% CI 1.45–2.06; p = 0.00001), Troponin (HR 1.65; 95% CI 1.31–2.07; p < 0.0001) and Galectin-3 (HR 1.82; 95% CI 1.27–2.61; p < 0.001) compared to lower baseline biomarker levels. Elevated levels of baseline BNP, NT-proBNP, Troponin and Galectin-3 were associated with increased all-cause mortality in a population of patients with AS. Therefore, a change in biomarker level could be considered to refine optimal timing of intervention. The results of this meta-analysis highlight the importance of biomarkers in risk stratification of AS, regardless of symptom status.
The Profound Influence of Lipid Composition on the Catalysis of the Drug Target NADH Type II Oxidoreductase
Authors: Godoy-Hernandez Albert , McMillan Duncan G. G.
Published: May 2021

Lipids play a pivotal role in cellular respiration, providing the natural environment in which an oxidoreductase interacts with the quinone pool. To date, it is generally accepted that negatively charged lipids play a major role in the activity of quinone oxidoreductases. By changing lipid compositions when assaying a type II NADH:quinone oxidoreductase, we demonstrate that phosphatidylethanolamine has an essential role in substrate binding and catalysis. We also reveal the importance of acyl chain composition, specifically c14:0, on membrane-bound quinone-mediated catalysis. This demonstrates that oxidoreductase lipid specificity is more diverse than originally thought and that the lipid environment plays an important role in the physiological catalysis of membrane-bound oxidoreductases.
Data-Driven Optimization of Piezoelectric Energy Harvesters via Pattern Search Algorithm
Authors: Huang Yang , Yi Zhiran , Hu Guosheng , Yang Bin
Published: May 2021

A data-driven optimization strategy based on a generalized pattern search (GPS) algorithm is proposed to automatically optimize piezoelectric energy harvesters (PEHs). As a direct search method, GPS can iteratively solve the derivative-free optimization problem. Taking the finite element method (FEM) as the solver and the GPS algorithm as the optimizer, the automatic interaction between the solver and optimizer ensures optimization with minimum human efforts, saving designers’ time and performing a more precise exploration in the parameter space to obtain better results. When employing it for the optimization of PEHs, the optimal length and thickness of PZT were 6.0 mm and 4.6 µm, respectively. Compared with reported high-output PEHs, this optimal structure showed an increase of 371% in output power, an improvement by 1000% in normalized power density, and a reduction of 254% in resonant frequency. Furthermore, Spearman’s rank correlation coefficient was calculated for evaluating the correlation among geometric parameters and output performance such as resonant frequency and output power, which provides a data-based perspective on the design and optimization of PEHs.
Study of the Vaginal Microbiota in Healthy Women of Reproductive Age
Authors: Alonzo Martínez Melanie C. , Cazorla Eduardo , Cánovas Esther , Martínez-Blanch Juan F. , Chenoll Empar , Climent Eric , Navarro-López Vicente
Published: May 2021

Understanding the characteristics of the vaginal microbiota of our patients allows us to carry out both a personalized therapeutic approach and a closer follow-up in those with microbiota susceptible to dysbiosis. This trial pursues the analysis of the vaginal microbiota of premenopausal women and its fluctuations within a four-week follow-up period. Vaginal samples of 76 fertile women were taken at a baseline visit and at a final visit (day 28 ± 5). To perform a phylogenetic study, we employed massive sequencing techniques to detect the 16S rRNA gene of the vaginal microbiota. The most prevalent vaginal microbial community was type I (34.87%), dominated by Lactobacillus crispatus. Vaginal microbial community types II (Lactobacillus gasseri) and V (Lactobacillus jensenii) were underrepresented in our population. When repeating the sampling process four weeks later, 75% of our patients maintained their initial bacterial community. In the follicular phase, the most recurrent microbiota was type III (Lactobacillus iners); in the periovulatory phase, types III and IV (microbial diversity); finally, in the luteal phase, the most frequent type was IV. The most prevalent vaginal bacterial community in our population was dominated by L. crispatus. The vaginal microbiota was resistant to changes in its bacterial community in 75% of our patients, even between consecutive menstrual cycles.
In Vitro Fermentation Characteristics and Fiber-Degrading Enzyme Kinetics of Cellulose, Arabinoxylan, β-Glucan and Glucomannan by Pig Fecal Microbiota
Authors: Bai Yu , Zhou Xingjian , Li Na , Zhao Jinbiao , Ye Hao , Zhang Shiyi , Yang Hongjian , Pi Yu , Tao Shiyu , Han Dandan , Zhang Shuai , Wang Junjun
Published: May 2021

Non-digestible polysaccharides are of great significance to human and animal intestinal health. Cellulose, arabinoxylan, β−glucan and glucomannan were selected in the present study to investigate the fermentation characteristics and fiber-degrading enzyme kinetics by inoculating pig fecal microbiota in vitro. Our results showed that fermentation of arabinoxylan and β-glucan produced the highest amount of acetate and lactate, respectively. The abundance of Prevotella_9 was the highest in β-glucan group and positively correlated with lactate and acetate. Glucomannan fermentation produced the highest amount of butyrate, and the abundance of Lachnospiraceae_XPB_1014_group and Bacteroides were the lowest. A significant negative correlation was found between Lachnospiraceae_XPB_1014_group, Bacteroides and butyrate. Exo-β-1,4-xylanase had the highest activity at 24 h during arabinoxylan fermentation. The activity of β-glucosidase and β-mannosidase at 36 h were higher than those at 15 h in the glucomannan group. The abundance of Prevotella_9 was positively correlated with β-glucosidase while Lachnospiraceae_XPB_1014_group and Bacteroides were negatively correlated with β-xylosidase. Our findings demonstrated the β-glucan and arabinoxylan promote proliferation of Prevotella_9, with the preference to secret β-glucosidase, β-mannosidase and the potential to produce lactate and acetate. Butyrate production can be improved by inhibiting the proliferation of Lachnospiraceae_XPB_1014_group and Bacteroides, which have the lack of potential to secret β-xylosidase.