bluuebunny/crossref_metadata_2025 huggingface dataset:
LncRNA TP73‐AS1 regulates miR‐495 expression to promote migration and invasion of nasopharyngeal carcinoma cells through junctional adhesion molecule A
Authors: Dai Bao‐Qiang , Jiang Xue , Feng Li‐Chun
Published: January 2021

The main obstacle to the treatment of nasopharyngeal carcinoma (NPC) is metastasis. Long non‐coding RNAs (lncRNAs) and microRNAs (miRNAs) are highly involved in the progression of NPC. In this study, we aimed to explore the regulatory role of lncRNA P73 antisense RNA 1 T (TP73‐AS1) and miR‐495 in migration and invasion of NPC cells. The expression levels of TP73‐AS1, miR‐495, and junctional adhesion molecule A (JAM‐A) in NPC tissue samples and cell lines were examined by quantitative real‐time PCR (qRT‐PCR) and/or Western blot. NPC cells were transfected with vectors overexpressing TP73‐AS1, short hairpin RNA (shRNA) against TP73‐AS1, shRNA against JAM‐A, miR‐495 mimics, miR‐495 inhibitor, and their corresponding negative controls as designated. The MTT assay, cell migration assay, and transwell assay were performed to detect cell viability, migration, and invasion, respectively. Dual‐luciferase reporter assay was performed to confirm the binding of TP73‐AS1 and miR‐495, and miR‐495 and JAM‐A. TP73‐AS1 and JAM‐A were significantly upregulated while miR‐495 was markedly downregulated in NPC tissues and cell lines compared to normal controls. The overexpression of TP73‐AS1 promoted migration and invasion of NPC cell line CNE‐2. TP73‐AS1 targeted miR‐495 and negatively regulated its expression. TP73‐AS1 upregulated the expression of JAM‐A through miR‐495. TP73‐AS1 mediated migration and invasion of CNE‐2 cells via upregulating JAM‐A. LncRNA TP73‐AS1, miR‐495, and JAM‐A are involved in migration and invasion of NPC cells. The TP73‐AS1/miR‐495/JAM‐A axis may serve as a therapeutic target for the treatment of NPC.
A pattern‐ and frequency‐reconfigurable antenna using liquid metal
Authors: Zhang Yuwei , Lin Shu , Yang Zhiqin , Li Bingqing , Cui Jingxuan , Jiao Jianlin
Published: January 2021

This article presents a pattern‐and frequency‐reconfigurable antenna based on movable liquid metal. The proposed antenna mainly consists of a printed three‐element Yagi‐Uda structure whose two parasitic elements are loaded with slots in the middle. Six movable liquid metal poles are filled in the microfluidic channels, which adhered to the surface of the three radiating arms of the Yagi‐Uda antenna. By moving these liquid metal poles, the slots can be shorted or opened and the equivalent electrical lengths of the director and fed‐dipole can be changed, thus adjusting the antenna in radiation pattern and frequency. As a result, this antenna can work at different states, which are mainly classified into five modes. To verify this design concept, a prototype of the proposed antenna is fabricated and measured. The measured results indicate that the antenna can operate in the frequency range from 1.52 to 3.2 GHz, and the peak gain can reach 7.3 dBi.
Design of wideband directional coupler based on secondary stage coupled structure
Authors: Liao Dun Wei , Fu Yun Qi
Published: January 2021

A wideband directional coupler based on secondary coupled structure is presented and implemented in this paper. The proposed coupler is formed by two stepped‐impedance shaped microstrip and parallel coupled‐lines with a stepped rectangular slot in a common ground plane. The phase velocity differences between the even‐ and odd‐modes of the coupler are compensated by introducing broadside principal coupling and parallel‐line secondary coupling structures, which can achieve a flat coupling without any enlarging the size of the coupler. The simulation results show that the designed device exhibit a coupling of 3 ± 1 dB across the 2.3–11.8 GHz band, which obtained a wideband over 5‐octave wider than other couplers. In order to demonstrate the effectiveness of the design, a prototype is fabricated and measured. The measured results reveal a coupling of 3 ± 1 dB across the 2.7–11.1 GHz band, which also show good performance.
Time‐resolved model for geothermal engineering in high porosity Slochteren sandstone
Authors: Singh Aditya , Fokker Peter A.
Published: January 2021

This work is an extension of the time‐resolved poro‐elasto‐plastic Mohr‐Coulomb model by Fokker et al to include a more realistic constitutive model. Experiments on Slochteren sandstone revealed that the inelastic deformation contributes significantly in compressive deformation almost in all stages of loading and instigated the development of a Cam‐Clay‐like model to reproduce the Slochteren sandstone behavior. This model was adopted for the current extension. A typical behavior of this model is that the presence of a borehole causes both elastic and inelastic deformation everywhere in the reservoir, as opposed to the conventional philosophy with plastic and elastic zones.

Our solution handles the spatial and temporal evolution of pressures, permeability, elastic and plastic properties under the assumption of symmetric loading. The applicability of the approach is demonstrated through a number of cases, like fluid injection, shut‐in, production, stimulation, and an injection‐production sequence.
SnO2/Sn/Carbon nanohybrid lithium‐ion battery anode with high reversible capacity and excellent cyclic stability
Authors: Wang Xiaoyan , Zheng Tianle , Cheng Ya‐Jun , Yin Shanshan , Xia Yonggao , Ji Qing , Xu Zhuijun , Liang Suzhe , Ma Liujia , Zuo Xiuxia , Meng Jian‐Qiang , Zhu Jin , Müller‐Buschbaum Peter
Published: January 2021

Ultrafine SnO2/Sn nanoparticles encapsulated into the adjustable mesoporous carbon matrix has been successfully fabricated by a facile route. The mesoporous carbon effectively improve the conductivity of the SnO2/Sn, prevent the aggregation, accommodate the strain of volume change and provide high interface area with the electrolyte, thus resulting in excellent cycling performance. A reversible capacity of 1105 mAh g–1 still retained after 290 cycles at 200 mA g–1, and the capacity still can keep at 107 mAh g–1 at high current density of 10 A g–1. The porous structures by the in situ SiOx template provide an appropriate specific surface area, which contributes to a relatively high capacitive contribution.
Deciding feasibility of a booking in the European gas market on a cycle is in P for the case of passive networks
Authors: Labbé Martine , Plein Fränk , Schmidt Martin , Thürauf Johannes
Published: January 2021

We show that the feasibility of a booking in the European entry‐exit gas market can be decided in polynomial time on single‐cycle networks that are passive, i.e., do not contain controllable elements. The feasibility of a booking can be characterized by solving polynomially many nonlinear potential‐based flow models for computing so‐called potential‐difference maximizing load flow scenarios. We thus analyze the structure of these models and exploit both the cyclic graph structure as well as specific properties of potential‐based flows. This enables us to solve the decision variant of the nonlinear potential‐difference maximization by reducing it to a system of polynomials of constant dimension that is independent of the cycle's size. This system of fixed dimension can be handled with tools from real algebraic geometry to derive a polynomial‐time algorithm. The characterization in terms of potential‐difference maximizing load flow scenarios then leads to a polynomial‐time algorithm for deciding the feasibility of a booking. Our theoretical results extend the existing knowledge about the complexity of deciding the feasibility of bookings from trees to single‐cycle networks.
BMI and Risk for Severe COVID‐19 Among Veterans Health Administration Patients
Authors: Breland Jessica Y. , Wong Michelle S. , Steers W. Neil , Yuan Anita H. , Haderlein Taona P. , Washington Donna L.
Published: January 2021

Objective

The purpose of this study was to assess associations between BMI and severe coronavirus disease 2019 (COVID‐19) outcomes: hospitalization, intensive care unit (ICU) admission, and mortality. A secondary aim was to investigate whether associations varied by age.

Methods

The cohort comprised patients in the Veterans Health Administration (VHA) who tested positive for COVID‐19 (N = 9,347). For each outcome, we fit piecewise logistic regression models with restricted cubic splines (knots at BMI of 23, 30, and 39), adjusting for age, sex, comorbidities, VHA nursing home residence, and race/ethnicity. Supplemental analyses included age‐by‐BMI interaction terms (α = 0.05).

Results

We found evidence of a nonlinear J‐curve association between BMI and likelihood of hospitalization and mortality. BMI was associated with increased odds for hospitalization, ICU admission, and mortality among patients with BMI 30 to 39 but decreased odds of hospitalization and mortality for patients with BMI 23 to 30. Patients under age 75 with BMI between 30 and 39 had increased odds for mortality with increasing BMI.

Conclusions

Odds for severe outcomes with COVID‐19 infection increased with increasing BMI for people with, but not without, obesity. This nonlinear relationship should be tested in future research. COVID‐19 public health messages in VHA, and broadly, should incorporate information about risks associated with all classes of obesity, particularly for those under age 75.
Future and the past of polymeric antioxidants
Authors: Filippov Sergey K. , Domnina Nina , Vol'eva Violetta
Published: January 2021

Hybrid macromolecular antioxidants has evolved into a mature research field last three decades. The main concept of this area was to design polymer conjugates that combine in one structure the hydrophilic properties of a polymer backbone and biological efficiency of hydrophobic antioxidants. Over the years, the understanding of different aspects of such approach has grown. In general, meticulous selection of each component is essential to obtain the conjugate with required properties. This review overview a plethora of hybrid macromolecular antioxidants synthesized over the last 20 years, together with the discussion their physicochemical properties and application for biomedical purposes.
Abnormal nuchal translucency followed by normal microarray analysis is associated with placental pathology‐related complications
Authors: Krispin Eyal , Kushnir Anya , Shemer Asaf , Rienstein Shlomit , Berkenstadt Michal , Yinon Yoav , Weisz Boaz
Published: January 2021

Objective

Identify placental pathology‐related complications, labor and neonatal outcomes in pregnancies complicated by pathological nuchal translucency (NT) with normal microarray analysis.

Methods

A retrospective study in which all women with singleton pregnancy who demonstrated NT above 3 mm and a normal microarray analysis were matched to women with normal NT and a normal microarray analysis (2013–2019) in a single tertiary academic center. The following placental pathology‐related parameters were measured: preeclampsia, oligohydramnios, suspected intrauterine growth restriction, abnormal Doppler studies or small for gestational age (SGA) neonates. The primary outcome was defined as a composite of complications related to placental pathology including preeclampsia and SGA neonate. Secondary outcomes were labor complications and neonatal morbidity.

Results

A total of 185 women were included in the study: of them, 47 presented an abnormal NT (study group) and 138 presented normal NT (controls). Groups did not significantly differ in baseline characteristics. Regarding primary outcome, all placental‐related complications frequencies were higher in the study group, with a composite rate of 17.02% versus 6.52% in controls (p = 0.042%). Secondary outcomes did not differ between groups.

Conclusions

Abnormal NT measurement presented in pregnancies with normal fetal microarray analysis is associated with higher rates of placental‐related complications.
Metalorganic Chemical Vapor Deposition Gallium Nitride with Fast Growth Rate for Vertical Power Device Applications
Authors: Zhang Yuxuan , Chen Zhaoying , Li Wenbo , Arehart Aaron R. , Ringel Steven A. , Zhao Hongping
Published: January 2021

The development of high‐quality gallium nitride (GaN) epitaxy with thick drift layer, low controllable doping, and high mobility is key for vertical high‐power devices. Herein, the effect of increasing trimethylgallium (TMGa) molar flow rate on the growth rate, impurity incorporation, charge compensation, surface morphology, and carrier mobility is systematically studied. An optimized metalorganic chemical vapor deposition GaN growth condition with a typical growth rate of 2 μm h−1 is used as the baseline. With significant suppression of background Si, other impurity concentrations, and a precise control of the doping precursor SiH4 flow, an electron concentration as low as 4 × 1015 cm−3 in n−‐GaN is achieved. Through increasing the TMGa flow rate, the GaN growth rate is increased to 5.2 μm h−1. Secondary ion mass spectroscopy results show that the background H, O, and Mg remain below detection limit, but C level is increased to 2 × 1016 cm−3. GaN growth on Mn‐doped semi‐insulating GaN substrate is performed to probe the transport properties of film with low dislocation densities. Hall measurement shows that an electron mobility decreases from 852 to 604 cm2 V−1 s−1 as the growth rate increases. Results from this work reveal the challenge and guidance for achieving GaN vertical high power devices.
Thermodynamic Analysis of Stress‐Mediated Barocaloric Effect, Electrocaloric Effect, and Energy Storage of PbZrO3 Antiferroelectric Film
Authors: Wang Yi-Kai , Zhao Quan-Liang , Di Jie-Jian , He Guang-Ping , Zhao Lei , Su Ting-Ting , Zhang Meng-Ying , Zhang Jie , Liang Xu , Bu Dan
Published: January 2021

A thermodynamic model is established to investigate the effects of internal stress in PbZrO3 (PZ) antiferroelectric (AFE) film on the barocaloric effect (BCE), electrocaloric effect (ECE), and energy storage properties. It is found that the internal stress can change the phase transition behaviors and free energy barriers among AFE, ferroelectric (FE), and paraelectric (PE) phases. For the BCE, it occurs only in the FE phase induced by stress or temperature. Under a certain temperature, the optimized negative and positive ECE can be obtained by controlling the internal stress and electric field. In addition, the switching electric field of the AFE→FE phase transition increases and causes a larger recoverable energy density with decreasing tensile stress. These results are analyzed and explained by tricritical points (3 cp) with different stresses, temperatures, and electric fields. Therefore, this thermodynamic model provides an effective route to optimize the BCE, ECE, and energy storage properties of PZ films.
Dynamic event‐triggered approach for networked control systems under denial of service attacks
Authors: Zhao Ning , Shi Peng , Xing Wen
Published: January 2021

This article studies the problems of exponential stabilization and ‐gain performance for networked control systems (NCSs) with transmission delays and periodic denial‐of‐service (DoS) attacks by exploring a resilient event‐triggered communication mechanism. First, a new resilient event‐triggered mechanism is developed to eliminate the adverse effects of network congestion caused by DoS attacks and decrease redundant communication so as to ensure efficient utilization of the limited network resources. The threshold parameter in the predefined event‐triggered condition can be adjusted according to the dynamic characteristics of the system. Then, an event‐driven control protocol is proposed, and a new switched NCS model is constructed. Sufficient conditions are then presented to ensure the exponential stability and ‐gain performance of the resulting closed‐loop system. Moreover, a co‐design scheme of the parameters in the event‐triggered condition and the controller gain is provided. Finally, the effectiveness and advantages of the new design techniques are verified through a comparative study for a robot manipulator control system.
Umbilical cord mesenchymal stem cells for COVID-19 acute respiratory distress syndrome: A double-blind, phase 1/2a, randomized controlled trial
Authors: Lanzoni Giacomo , Linetsky Elina , Correa Diego , Messinger Cayetano Shari , Alvarez Roger A. , Kouroupis Dimitrios , Alvarez Gil Ana , Poggioli Raffaella , Ruiz Phillip , Marttos Antonio C. , Hirani Khemraj , Bell Crystal A. , Kusack Halina , Rafkin Lisa , Baidal David , Pastewski Andrew , Gawri Kunal , Leñero Clarissa , Mantero Alejandro M. A. , Metalonis Sarah W. , Wang Xiaojing , Roque Luis , Masters Burlett , Kenyon Norma S. , Ginzburg Enrique , Xu Xiumin , Tan Jianming , Caplan Arnold I. , Glassberg Marilyn K. , Alejandro Rodolfo , Ricordi Camillo
Published: January 2021

Acute respiratory distress syndrome (ARDS) in COVID-19 is associated with high mortality. Mesenchymal stem cells are known to exert immunomodulatory and anti-inflammatory effects and could yield beneficial effects in COVID-19 ARDS. The objective of this study was to determine safety and explore efficacy of umbilical cord mesenchymal stem cell (UC-MSC) infusions in subjects with COVID-19 ARDS. A double-blind, phase 1/2a, randomized, controlled trial was performed. Randomization and stratification by ARDS severity was used to foster balance among groups. All subjects were analyzed under intention to treat design. Twenty-four subjects were randomized 1:1 to either UC-MSC treatment (n = 12) or the control group (n = 12). Subjects in the UC-MSC treatment group received two intravenous infusions (at day 0 and 3) of 100 ± 20 × 106 UC-MSCs; controls received two infusions of vehicle solution. Both groups received best standard of care. Primary endpoint was safety (adverse events [AEs]) within 6 hours; cardiac arrest or death within 24 hours postinfusion). Secondary endpoints included patient survival at 31 days after the first infusion and time to recovery. No difference was observed between groups in infusion-associated AEs. No serious adverse events (SAEs) were observed related to UC-MSC infusions. UC-MSC infusions in COVID-19 ARDS were found to be safe. Inflammatory cytokines were significantly decreased in UC-MSC-treated subjects at day 6. Treatment was associated with significantly improved patient survival (91% vs 42%, P = .015), SAE-free survival (P = .008), and time to recovery (P = .03). UC-MSC infusions are safe and could be beneficial in treating subjects with COVID-19 ARDS.
Role of Nanopore Geometry in Particle Resolution by Resistive‐Pulse Sensing
Authors: Yilmaz Durdane , Kaya Dila , Kececi Kaan , Dinler Ali
Published: January 2021

Nanopores as resistive pulse sensors can effectively detect single‐particles of several types including molecules without the need of labelling. Although pore geometry has a significant role in the formation of the obtained signals, it has been investigated relatively little. In the present study, we run simulations to consider the effects of pore geometry and compare conical, cigar and hourglass shaped pores at the conditions where both the resistive and conductive pulses occur in the conical pore. We examine the pulse magnitudes in relation to variations in size and charge for spherical particles. We also compare the pore geometries for when the particles pass through an off‐axis trajectory, close to the pore wall. The results show that distorting the conical shape into an hourglass or a cigar shape can significantly enhance the sensing capability of the nanopore. We show that at identical conditions, the hourglass pore only generates resistive pulses unlike the other two geometries. In the absence of the conductive pulses, the hourglass pore is robust to the variations in the particle charge and its pulse magnitudes are less affected by the particle trajectory than the cigar pore. The comparison shows that the hourglass pore may yield the best performance for size discrimination purposes. On the other hand, the conductive pulses carry valuable information and accordingly, by the aid of conductive pulses, the cigar pore can outperform the other geometries for the detection of charged particles.
Why Does Nitriding of Grain‐Oriented Silicon Steel Become Slower at Higher Temperature?
Authors: Guo Qinyi , Li Xianhao , Gong Peng , Nutter John , Rainforth William Mark , Luo Haiwen
Published: January 2021

The nitriding process plays an essential role in the production of grain‐oriented silicon steel (GOSS) via the acquired‐inhibitor process. It is surprising at first glance to find that the increase of temperature from 840 to 930 °C retards the nitriding of GOSS rather than accelerating it. By both extensive microstructural characterization and thermodynamic calculations, this is attributed to the formation of austenite at high temperature in the oxidization layer, in which N atoms diffuse at a much lower rate than in ferrite. It is concluded that there exists an upper‐limit temperature for the efficient nitriding of GOSS, which is determined by both the preceding decarburization process and the nitriding atmosphere.
Large Eddy Simulation of Transient Flow, Particle Transport, and Entrapment in Slab Mold with Double‐Ruler Electromagnetic Braking
Authors: Yin Yanbin , Zhang Jiongming , Ma Haitao , Zhou Qinghai
Published: January 2021

To study the transient transport and capture of inclusions and argon bubbles simultaneously in slab mold with double‐ruler electromagnetic braking (EMBr), a transient large eddy simulation model coupling molten steel flow, solidification, electromagnetic field, and particle motion is constructed. In this model, momentum transfer between argon bubbles and molten steel is implemented by two‐way coupling. The results indicate that the EMBr changes the molten steel transient flow pattern in the liquid pool. Due to the braking effect, the asymmetry and instability of the molten steel transient flow are weakened. Moreover, EMBr changes the transient particle (inclusion and argon bubble) transports inside the liquid pool. The particle motions inside the liquid pool are constrained, and the dispersion of the particles inside the liquid pool is weakened by EMBr. In addition, the contents of particles within the slab surface layer are decreased under the application of EMBr. Nevertheless, in the slab interior, the contents of the particles under the application of EMBr are higher than those in the absence of EMBr.
Application of artificial neural network for predicting dynamic along‐wind response of tall buildings
Authors: Nikose Trupti J. , Sonparote Ranjan S.
Published: January 2021

This paper presents the simplified approach based on the artificial neural network (ANN) for predictions of the dynamic along‐wind response in the context of the Indian Wind Standard IS 875 (Part 3): 2015. This standard provides direct guidelines for the specific aspect ratio of buildings (h/b ratio as 3, 5, 10, and 20) for assessing along‐wind loads. Evaluation of dynamic wind load and its responses, for the aspect ratio not specified in the IS 875 (Part 3): 2015, may have to be estimated by the boundary layer wind tunnel experiment or other computational techniques. Both the experimentation and computational methods are expensive in terms of time and the resources required. Alternatively, ANN is an efficient and cost‐effective computational technique that can be employed to estimate the dynamic wind response of a building. In this paper, ANN predicted estimations are presented for calculating dynamic along‐wind base shear and base bending moment of a tall building. The response is generated using the best fit ANN model for the aspect ratio (h/b) ranging in between 3 and 20. Finally, these responses were used to propose a simplified empirical equation as a function of aspect ratio, side ratio, wind velocity, and terrain category. Furthermore, charts were developed for calculating the story shear force and story bending moments for the building heights varying from 100 to 250 m. The proposed new approach is one of the quick evaluators for dynamic along‐wind response of the tall buildings.
Ocular hamartoma in a five‐day‐old calf
Authors: Hwang Hyejin , Kim Daesik , Hillers Kim , Kim Min Su
Published: January 2021

Hamartomas are developed focal malformations that resemble neoplasms, resulting from faulty development in an organ. They are composed of a disorganised mixture of cells and tissues normally found in the area of the body where the growth occurs, and develop and grow at the same rate as adjacent tissues. A five‐day‐old male native Korean calf presented with a left ocular mass, with tissue protruding from the eye. No pain response was elicited on palpation. Based on clinical examination, enucleation was performed. The majority of the mass consisted of bland fibro‐adipose tissue with mild inflammation, and no other abnormalities were noted. Histopathology of the left eye mass was consistent with an ocular hamartoma. The calf recovered well and was discharged from the hospital. The case report is the first known example of an ocular hamartoma manifesting in a newborn calf.
The feasibility of shortwave infrared imaging and inverse numerical modeling for rapid estimation of soil hydraulic properties
Authors: Babaeian Ebrahim , Sadeghi Morteza , Gohardoust Mohammad R. , Arthur Emmanuel , Effati Mohaddese , Jones Scott B. , Tuller Markus
Published: January 2021

Measurements of the soil water characteristic (SWC) and unsaturated hydraulic conductivity [K(h)] curves, which are at the core of modeling flow and transport processes in porous media, are laborious and prone to experimental errors. To overcome some of the current experimental limitations, we examined the potential feasibility of shortwave infrared (SWIR) imaging of water imbibition into dry soil during a controlled laboratory experiment in conjunction with inverse numerical modeling to determine the wetting SWC and the K(h) function. To generate time series of high‐resolution surface moisture maps, the imaged surface reflectance was converted to surface soil moisture via a recently developed physical radiative transfer model. The moisture time series were then used to parameterize the HYDRUS 2D/3D numerical code for forward simulations. The optimization was performed with simulated annealing in MATLAB that was linked to HYDRUS 2D/3D to automate the inversion process. The obtained SWC wetting curves were subsequently compared with Tempe cell and Dewpoint PotentiaMeter measurements. Although further research and refinements of the proposed method are needed, the results of this exploratory study obtained for a broad range of soil textures are promising and demonstrate the potential feasibility of the proposed approach for rapid estimation of soil hydraulic properties.
Filter for penetration resistance correction in cultivated and compacted Histosols
Authors: Guedessou Cedrick Victoir , Caron Jean , Libbrecht Christophe , Gallichand Jacques , Dessureault‐Rompré Jacynthe
Published: January 2021

The objective of this study was to design, using field data, a filter to correct the soil penetration resistance (PR) values by considering all the effects (penetration friction component [PFC], varying penetration rate, and shocks) that bias PR interpretation. The data used were collected in cultivated peatlands of Montérégie (Canada) known for their advanced state of compaction. Penetration resistance (standard measurements) and cone resistance (CR) measurements (successive measurements per 10‐cm layer) were carried out on four peatlands (five stations per peatland). The filter components, a multi‐resolution analysis (AMR), a polynomial model, and a quantification and removal of PFC were identified and were used to design the filter and tested by cross‐validation. Our study showed that PFC exists (p value < 5%) and does not depend on the peatland on which the measurements are made. An average filter has therefore been designed for the entire site and its effectiveness has been demonstrated. An application to the data collected in 10 fields on the site made it possible to identify the main soil density profiles existing in Montérégie and to quantify the average PFC characterizing these soils. We noticed that, on average, PFC represents between 18.6 and 41% of the PR value. The combined results of the statistical and physical analyses of the filter made it possible to recommend degrees 2 (D2), 3 (D3), and 5 (D5) of the polynomial model to adjust density profiles of cultivated Histosols when there are no, one, or two compact layers.
Evaluation eines nutzerorientierten eLearning-Angebots für die Augenheilkunde
Authors: Müller Andreas , Schmidt Franziska , Pfeiffer Norbert , Brill Anita , Prokosch Verena
Published: January 2021

Hintergrund

Digitales Lernen wird in humanmedizinischen Studiengängen meist mittels Learning-Management-Plattformen wie „Ilias“ umgesetzt. Oft werden Vorlesungsfolien und Organisatorisches hierbei online gestellt. Allerdings nutzen Studierende auch externe Quellen und Lernformate in ihrem Lernprozess. Wir stellen hier die Neugestaltung unseres digitalen Lernangebotes und dessen Beurteilung durch die Studenten vor.

Ziel der Arbeit

Evaluation einer eLearning-Plattform für Studierende der Humanmedizin, welche übliches Lernverhalten berücksichtigt.

Material und Methoden

Die Plattform sollte, geordnet nach Augenstrukturen, eine Auswahl an in- und externen Lernmaterialien verknüpfen. Zu jedem Thema erstellten wir ein Skript zu den jeweiligen zentralen Inhalten, Fallbeispiele, Vorlesungsfolien, Übungsfragen und Kapitel von Lehrbüchern sowie die entsprechende Amboss-Lernkarte (Amboss GmbH, Berlin, Deutschland). Am Semesterende erfolgte eine Evaluation der Plattform. In einem Fragebogen wurden verschiedene Aussagen auf Ordinalskalen von Studierenden bewertet.

Ergebnisse

Die Plattform wurde mit 1,47 ± 0,54 (Mittelwert ± Standardabweichung) bewertet (n = 107; Schulnote 1 = sehr gut, 6 = ungenügend). Sie wurde mit 1,62 ± 0,77 als sehr hilfreich für das eigene Lernen empfunden (1 = sehr hilfreich, 7 = gar nicht hilfreich). Die Strukturierung der internen und externen Lernmaterialien wurde als sehr gut mit 1,44 ± 0,66 bewertet (1 = sehr gut, 7 = sehr schlecht). Im Median wurde eine Nutzungsdauer von 1–5 h angegeben (Ordinalskala <1, 1–5, 6–10, 15–20, >20 h).

Diskussion

Es erscheint sinnvoll, häufig genutzte externe Lernmaterialien gezielt mit der eigenen curricularen Struktur und ihren Inhalten zu verknüpfen und digital auf einer Plattform zur Verfügung zu stellen, um eine zeitgemäße Basis für Wissenserwerb für Studierende in der Augenheilkunde zu schaffen.
The role of calcium homeostasis remodeling in inherited cardiac arrhythmia syndromes
Authors: Hamilton Shanna , Veress Roland , Belevych Andriy , Terentyev Dmitry
Published: January 2021

Sudden cardiac death due to malignant ventricular arrhythmias remains the major cause of mortality in the postindustrial world. Defective intracellular Ca2+ homeostasis has been well established as a key contributing factor to the enhanced propensity for arrhythmia in acquired cardiac disease, such as heart failure or diabetic cardiomyopathy. More recent advances provide a strong basis to the emerging view that hereditary cardiac arrhythmia syndromes are accompanied by maladaptive remodeling of Ca2+ homeostasis which substantially increases arrhythmic risk. This brief review will focus on functional changes in elements of Ca2+ handling machinery in cardiomyocytes that occur secondary to genetic mutations associated with catecholaminergic polymorphic ventricular tachycardia, and long QT syndrome.
A linear-elasticity-based mesh moving method with no cycle-to-cycle accumulated distortion
Authors: Tonon Patrícia , Sanches Rodolfo André Kuche , Takizawa Kenji , Tezduyar Tayfun E.
Published: January 2021

Good mesh moving methods are always part of what makes moving-mesh methods good in computation of flow problems with moving boundaries and interfaces, including fluid–structure interaction. Moving-mesh methods, such as the space–time (ST) and arbitrary Lagrangian–Eulerian (ALE) methods, enable mesh-resolution control near solid surfaces and thus high-resolution representation of the boundary layers. Mesh moving based on linear elasticity and mesh-Jacobian-based stiffening (MJBS) has been in use with the ST and ALE methods since 1992. In the MJBS, the objective is to stiffen the smaller elements, which are typically placed near solid surfaces, more than the larger ones, and this is accomplished by altering the way we account for the Jacobian of the transformation from the element domain to the physical domain. In computing the mesh motion between time levels$$t_n$$tnand$$t_{n+1}$$tn+1with the linear-elasticity equations, the most common option is to compute the displacement from the configuration at$$t_n$$tn. While this option works well for most problems, because the method is path-dependent, it involves cycle-to-cycle accumulated mesh distortion. The back-cycle-based mesh moving (BCBMM) method, introduced recently with two versions, can remedy that. In the BCBMM, there is no cycle-to-cycle accumulated distortion. In this article, for the first time, we present mesh moving test computations with the BCBMM. We also introduce a version we call “half-cycle-based mesh moving” (HCBMM) method, and that is for computations where the boundary or interface motion in the second half of the cycle consists of just reversing the steps in the first half and we want the mesh to behave the same way. We present detailed 2D and 3D test computations with finite element meshes, using as the test case the mesh motion associated with wing pitching. The computations show that all versions of the BCBMM perform well, with no cycle-to-cycle accumulated distortion, and with the HCBMM, as the wing in the second half of the cycle just reverses its motion steps in the first half, the mesh behaves the same way.
Timelines and rebleeds in patients admitted into neurosurgical care for aneurysmal subarachnoid haemorrhage
Authors: Sorteberg Angelika , Romundstad Luis , Sorteberg Wilhelm
Published: January 2021

Background

Mortality and morbidity of aneurysmal subarachnoid haemorrhage (aSAH) remain high, and prognosis is influenced by multiple non-modifiable factors such as aSAH severity. By analysing the chronology of aSAH management, we aim at identifying modifiable factors with emphasis on the occurrence of rebleeds in a setting with 24/7 surgical and endovascular availability of aneurysm repair and routine administration of tranexamic acid.

Methods

Retrospective analysis of institutional quality registry data of aSAH cases admitted into neurosurgical care during the time period 01 January 2013–31 December 2017. We registered time and mode of aneurysm repair, haemorrhage patterns, course of treatment, mortality and functional outcome. Rebleeding was scored along the entire timeline from ictus to discharge from the primary stay.

Results

We included 544 patients (368, 67.6% female), aged 58 ± 14 years (range 1–95 years). Aneurysm repair was performed in 486/544 (89.3%) patients at median 7.4 h after arrival and within 3, 6, 12 and 24 h in 26.8%, 44.7%, 73.0% and 96.1%, respectively. There were circadian variations in time to repair and in rebleeds. Rebleeding prior to aneurysm repair occurred in 9.7% and increased with aSAH severity and often in conjunction with patient relocations or interventions. Rebleeds occurred more often during surgical repair outside regular working hours, whereas rebleeds after repair (1.8%) were linked to endovascular repair.

Conclusions

The risk of rebleed is imminent throughout the entire timeline of aSAH management even with ultra-early aneurysm repair. Several modifiable factors can be linked to the occurrence of rebleeds and they should be identified and optimised within neurosurgical departments.
Raman spectroscopic study of cervical precancerous lesions and cervical cancer
Authors: Wang Jing , Zheng Cheng-Xia , Ma Cai-Ling , Zheng Xiang-Xiang , Lv Xiao-Yi , Lv Guo-Dong , Tang Jun , Wu Guo-Hua
Published: January 2021

Early detection of cervical lesions, accurate diagnosis of cervical lesions, and timely and effective therapy can effectively avoid the occurrence of cervical cancer or improve the survival rate of patients. In this paper, the spectra of tissue sections of cervical inflammation (n = 60), CIN (cervical intraepithelial neoplasia) I (n = 30), CIN II (n = 30), CIN III (n = 30), cervical squamous cell carcinoma (n = 30), and cervical adenocarcinoma (n = 30) were collected by a confocal Raman micro-spectrometer (LabRAM HR Evolution, Horiba France SAS, Villeneuve d’Ascq, France). The Raman spectra of six kinds of cervical tissues were analyzed, the dominant Raman peaks of different kinds of tissues were summarized, and the differences in chemical composition between the six tissue samples were compared. An independent sample t test (p ≤ 0.05) was used to analyze the difference of average relative intensity of Raman spectra of six types of cervical tissues. The difference of relative intensity of Raman spectra of six kinds of tissues can reflect the difference of biochemical components in six kinds of tissues and the characteristic of biochemical components in different kinds of tissues. The classification models of cervical inflammation, CIN I, CIN II, CIN III, cervical squamous cell carcinoma, and cervical adenocarcinoma were established by using a support vector machine (SVM) algorithm. Six types of cervical tissues were classified and identified with an overall diagnostic accuracy of 85.7%. This study laid a foundation for the application of Raman spectroscopy in the clinical diagnosis of cervical precancerous lesions and cervical cancer.
Neuroblastoma and the epigenome
Authors: Fetahu Irfete S. , Taschner-Mandl Sabine
Published: January 2021

Neuroblastoma (NB) is a pediatric cancer of the sympathetic nervous system and one of the most common solid tumors in infancy. Amplification of MYCN, copy number alterations, numerical and segmental chromosomal aberrations, mutations, and rearrangements on a handful of genes, such as ALK, ATRX, TP53, RAS/MAPK pathway genes, and TERT, are attributed as underlying causes that give rise to NB. However, the heterogeneous nature of the disease—along with the relative paucity of recurrent somatic mutations—reinforces the need to understand the interplay of genetic factors and epigenetic alterations in the context of NB. Epigenetic mechanisms tightly control gene expression, embryogenesis, imprinting, chromosomal stability, and tumorigenesis, thereby playing a pivotal role in physio- and pathological settings. The main epigenetic alterations include aberrant DNA methylation, disrupted patterns of posttranslational histone modifications, alterations in chromatin composition and/or architecture, and aberrant expression of non-coding RNAs. DNA methylation and demethylation are mediated by DNA methyltransferases (DNMTs) and ten-eleven translocation (TET) proteins, respectively, while histone modifications are coordinated by histone acetyltransferases and deacetylases (HATs, HDACs), and histone methyltransferases and demethylases (HMTs, HDMs). This article focuses predominately on the crosstalk between the epigenome and NB, and the implications it has on disease diagnosis and treatment.
Lightweight porous silica foams with extreme-low dielectric permittivity and loss for future 6G wireless communication technologies
Authors: Pálvölgyi Petra S. , Sebők Daniel , Szenti Imre , Bozo Eva , Ervasti Henri , Pitkänen Olli , Hannu Jari , Jantunen Heli , Leinonen Marko E. , Myllymäki Sami , Kukovecz Akos , Kordas Krisztian
Published: January 2021

In the next generation wireless communication systems operating at near terahertz frequencies, dielectric substrates with the lowest possible permittivity and loss factor are becoming essential. In this work, highly porous (98.9% ± 0.1%) and lightweight silica foams (0.025 ± 0.005 g/cm3), that have extremely low relative permittivity (εr= 1.018 ± 0.003 at 300 GHz) and corresponding loss factor (tanδ< 3 × 10−4at 300 GHz) are synthetized by a template-assisted sol-gel method. After dip-coating the slabs of foams with a thin film of cellulose nanofibers, sufficiently smooth surfaces are obtained, on which it is convenient to deposit electrically conductive planar thin films of metals important for applications in electronics and telecommunication devices. Here, micropatterns of Ag thin films are sputtered on the substrates through a shadow mask to demonstrate double split-ring resonator metamaterial structures as radio frequency filters operating in the sub-THz band.
Treatment Response of Deferiprone in Infratentorial Superficial Siderosis: a Systematic Review
Authors: Flores Martin Andreas , Shanmugarajah Priya , Hoggard Nigel , Hadjivassiliou Marios
Published: January 2021

Superficial siderosis describes haemosiderin deposition on the surface of the brain. When present on infratentorial structures, it can cause ataxia, sensorineural hearing loss and pyramidal signs. There is no proven treatment and patients experience slow progression of symptoms. Iron-chelating agents have been suggested as a therapeutic option and deferiprone is suited as it crosses the blood-brain barrier. However, deferiprone is reported to have a 1–2% risk of agranulocytosis. We performed a systematic review on treatment of infratentorial superficial siderosis with deferiprone based on PRISMA guidelines. Studies were included if in English or an English language translation was available, were about human subjects and referred to patients with ataxia. Studies were excluded if they did not possess an English translation, included animal studies or did not have ataxia. Studies were excluded if they discussed cerebral amyloid angiopathy or siderosis of other regions. Eleven papers were included. We identified 69 patients. Seventeen patients (25%) discontinued the drug. The most encountered adverse effect was anaemia (21.7%). Neutropaenia was observed in 8.7% and agranulocytosis in 5.8% of patients. Clinically, response varied, and stability or improvement was seen across neurological domains in 6 studies while 5 showed a mixed response. On imaging, 13 (28.9%) patients improved, 24 (53.3%) stabilised and 8 (17.8%) deteriorated. A prospective international centralised register of patients should be developed to inform the design and conduct of a multicentre, placebo-controlled, randomised clinical trial to evaluate the efficacy of deferiprone. The evidence from this systematic review is that deferiprone is a promising intervention.
Clinical determinants of early spontaneous conversion to sinus rhythm in patients with atrial fibrillation
Authors: Pluymaekers N. A. H. A. , Dudink E. A. M. P. , Weijs B. , Vernooy K. , Hartgerink D. E. J. , Jacobs J. S. , Erküner Ö. , Marcks N. G. H. M. , van Cauteren Y. J. M. , Dinh T. , ter Bekke R. M. A. , Sels J. E. M. W. , Delnoij T. S. R. , Geyik Z. , Driessen R. G. H. , Linz D. K. , den Uijl D. W. , Crijns H. J. G. M. , Luermans J. G. L. M.
Published: January 2021

Background

The current standard of care for acute atrial fibrillation (AF) focuses primarily on immediate restoration of sinus rhythm by cardioversion, although AF often terminates spontaneously.

Objective

To identify determinants of early spontaneous conversion (SCV) in patients presenting at the emergency department (ED) because of AF.

Methods

An observational study was performed of patients who visited the ED with documented AF between July 2014 and December 2016. The clinical characteristics and demographics of patients with and without SCV were compared.

Results

We enrolled 943 patients (age 69 ± 12 years, 47% female). SCV occurred within 3 h of presentation in 158 patients (16.8%). Logistic regression analysis showed that duration of AF <24 h [odds ratio (OR) 7.7, 95% confidence interval (CI) 3.5–17.2, p < 0.001], left atrial volume index <42 ml/m2 (OR 1.8, 95% CI 1.2–2.8, p = 0.010), symptoms of near-collapse at presentation (OR 2.4, 95% CI 1.2–5.1, p = 0.018), a lower body mass index (BMI) (OR 0.9, 95% CI 0.91–0.99, p = 0.028), a longer QTc time during AF (OR 1.01, 95% CI 1.0–1.02, p = 0.002) and first-detected AF (OR 2.5, 95% CI 1.6–3.9, p < 0.001) were independent determinants of early SCV.

Conclusion

Early spontaneous conversion of acute AF occurs in almost one-sixth of admitted patients during a short initial observation in the ED. Spontaneous conversion is most likely to occur in patients with first-onset, short-duration AF episodes, lower BMI, and normal left atrial size.
Performance of a simplified HEART score and HEART-GP score for evaluating chest pain in urgent primary care
Authors: Harskamp R. E. , Kleton M. , Smits I. H. , Manten A. , Himmelreich J. C. L. , van Weert H. C. P. M. , Rietveld R. P. , Lucassen W. A. M.
Published: January 2021

Background

Chest pain is a common symptom in urgent primary care. The distinction between urgent and non-urgent causes can be challenging. A modified version of the HEART score, in which troponin is omitted (‘simplified HEART’) or replaced by the so-called ‘sense of alarm’ (HEART-GP), may aid in risk stratification.

Method

This study involved a retrospective, observational cohort of consecutive patients evaluated for chest pain at a large-scale, out-of-hours, regional primary care facility in the Netherlands, with 6‑week follow-up for major adverse cardiac events (MACEs). The outcome of interest is diagnostic accuracy, including positive predictive value (PPV) and negative predictive value (NPV).

Results

We included 664 patients; MACEs occurred in 4.8% (n = 32). For  simplified HEART and HEART-GP, we found C‑statistics of 0.86 (95% confidence interval (CI) 0.80–0.91) and 0.90 (95% CI 0.85–0.95), respectively. Optimal diagnostic accuracy was found for a simplified HEART score ≥2 (PPV 9%, NPV 99.7%), HEART-GP score ≥3 (PPV 11%, NPV 99.7%) and HEART-GP score ≥4 (PPV 16%, NPV 99.4%). Physicians referred 157 patients (23.6%) and missed 6 MACEs. A simplified HEART score ≥2 would have picked up 5 cases, at the expense of 332 referrals (50.0%, p < 0.001). A HEART-GP score of ≥3 and ≥4 would have detected 5 and 3 MACEs and led to 293 (44.1%, p < 0.001) and 186 (28.0%, p = 0.18) referrals, respectively.

Conclusion

HEART-score modifications including the physicians’ ‘sense of alarm’ may be used as a risk stratification tool for chest pain in primary care in the absence of routine access to troponin assays. Further validation is warranted.
TOMARES
Authors: Lottes Laura Malena , Kaiser Nils , Goossens Nils , Oelze Holger W. , Braxmaier Claus
Published: January 2021

In aerospace industry, saving mass on spacecrafts always remain in large demand to save launch costs or increase the available payload mass. A case study is carried out designing a first concept of an additive manufactured flywheel of a reaction wheel, as it is one of the heaviest parts of wheel systems. As an objective the mass is minimized, while obtaining an angular momentum suitable according to mission requirements and maintaining recent performances. As references the SeaSAT mission and a commercial reaction wheel are used. The work includes a preliminary dimension of the flywheels design space by MATLAB calculations, where in total 15 shapes are analyzed and compared. The most promising design space is afterwards analyzed via the finite-element tool ANSYS and is defined as the reference flywheel. The reference flywheel is used for topology optimizations (ANSYS Topology Optimization), where different boundary conditions are considered. The final designed flywheel obtains 16% higher energy density than the reference flywheel and withstands the mission loads. It can be concluded that it was possible to design a flywheel obtaining less mass while keeping the expected performance.