bluuebunny/crossref_metadata_2025 huggingface dataset:
Constructing deep-blue bis-tridentate Ir(iii) phosphors with fluorene-based dianionic chelates
Authors: Zhu Ze-Lin , Chen Wen-Cheng , Ni Shao-Fei , Yan Jie , Wang Sheng Fu , Fu Li-Wen , Tsai Han-Yan , Chi Yun , Lee Chun-Sing
Published: December 2020

Novel fluorene-based bis-tridentate Ir(iii) phosphors are capable of exhibiting both improved stability and efficient deep-blue emission in solution.
Value of the cell cycle arrest biomarkers in the diagnosis of pregnancy-related acute kidney injury
Authors: El Minshawy Osama , Khedr Mahmoud Hassan Sayed , Youssuf Ayman Moheb , Abo Elela Mostafa , Kamel Fatma Mohamed Mohamed , Keryakos Hesham Kamal Habeeb
Published: December 2020

Background: Pregnancy-related acute kidney injury (PRAKI) is still a common serious problem in developing countries. Insulin-like growth factor-binding protein 7 (IGFBP7) and tissue inhibitor metalloproteinases-2 (TIMP-2) can identify critically ill patients at risk for the development of severe AKI. Aim: To identify main causes and timing of PRAKI and to study the G1 cell cycle arrest biomarkers in cases diagnosed with (PRAKI) as a diagnostic tool. Methods: 80 pregnant women diagnosed with PRAKI were recruited from a single hospital as well as 30 age-matched pregnant women with normal pregnancy participated in the present study. A urine specimen was collected from all study participants with established AKI within 24 h of ICU admission to measure [TIMP-2]*[IGFBP7]. Results: The incidence of PRAKI was 1.1%. The most common cause of PRAKI is pre-eclampsia/eclampsia spectrum (61%). Most of the cases occur in the third trimester (60%) and postpartum period (23%). At a cutoff 0.33 ng/ml, the estimated sensitivity and specificity of urinary [TIMP-2]*[IGFBP7] in predicting PRAKI is 100% (95% CI) with NPV and PPV are 100%. Conclusion: Urinary [TIMP-2]*[IGFBP7] serves as a sensitive and specific biomarker in the diagnosis of PRAKI.
The impact of photorespiration on plant primary metabolism through metabolic and redox regulation
Authors: Timm Stefan
Published: December 2020

Photorespiration is an inevitable trait of all oxygenic phototrophs, being the only known metabolic route that converts the inhibitory side-product of Rubisco's oxygenase activity 2-phosphoglycolate (2PG) back into the Calvin–Benson (CB) cycle's intermediate 3-phosphoglycerate (3PGA). Through this function of metabolite repair, photorespiration is able to protect photosynthetic carbon assimilation from the metabolite intoxication that would occur in the present-day oxygen-rich atmosphere. In recent years, much plant research has provided compelling evidence that photorespiration safeguards photosynthesis and engages in cross-talk with a number of subcellular processes. Moreover, the potential of manipulating photorespiration to increase the photosynthetic yield potential has been demonstrated in several plant species. Considering this multifaceted role, it is tempting to presume photorespiration itself is subject to a suite of regulation mechanisms to eventually exert a regulatory impact on other processes, and vice versa. The identification of potential pathway interactions and underlying regulatory aspects has been facilitated via analysis of the photorespiratory mutant phenotype, accompanied by the emergence of advanced omics’ techniques and biochemical approaches. In this mini-review, I focus on the identification of enzymatic steps which control the photorespiratory flux, as well as levels of transcriptional, posttranslational, and metabolic regulation. Most importantly, glycine decarboxylase (GDC) and 2PG are identified as being key photorespiratory determinants capable of controlling photorespiratory flux and communicating with other branches of plant primary metabolism.
Biofilm and swarming emergent behaviours controlled through the aid of biophysical understanding and tools
Authors: Grobas Iago , Bazzoli Dario G. , Asally Munehiro
Published: December 2020

Bacteria can organise themselves into communities in the forms of biofilms and swarms. Through chemical and physical interactions between cells, these communities exhibit emergent properties that individual cells alone do not have. While bacterial communities have been mainly studied in the context of biochemistry and molecular biology, recent years have seen rapid advancements in the biophysical understanding of emergent phenomena through physical interactions in biofilms and swarms. Moreover, new technologies to control bacterial emergent behaviours by physical means are emerging in synthetic biology. Such technologies are particularly promising for developing engineered living materials (ELM) and devices and controlling contamination and biofouling. In this minireview, we overview recent studies unveiling physical and mechanical cues that trigger and affect swarming and biofilm development. In particular, we focus on cell shape, motion and density as the key parameters for mechanical cell–cell interactions within a community. We then showcase recent studies that use physical stimuli for patterning bacterial communities, altering collective behaviours and preventing biofilm formation. Finally, we discuss the future potential extension of biophysical and bioengineering research on microbial communities through computational modelling and deeper investigation of mechano-electrophysiological coupling.
Nanopores: a versatile tool to study protein dynamics
Authors: Schmid Sonja , Dekker Cees
Published: December 2020

Proteins are the active workhorses in our body. These biomolecules perform all vital cellular functions from DNA replication and general biosynthesis to metabolic signaling and environmental sensing. While static 3D structures are now readily available, observing the functional cycle of proteins – involving conformational changes and interactions – remains very challenging, e.g., due to ensemble averaging. However, time-resolved information is crucial to gain a mechanistic understanding of protein function. Single-molecule techniques such as FRET and force spectroscopies provide answers but can be limited by the required labelling, a narrow time bandwidth, and more. Here, we describe electrical nanopore detection as a tool for probing protein dynamics. With a time bandwidth ranging from microseconds to hours, nanopore experiments cover an exceptionally wide range of timescales that is very relevant for protein function. First, we discuss the working principle of label-free nanopore experiments, various pore designs, instrumentation, and the characteristics of nanopore signals. In the second part, we review a few nanopore experiments that solved research questions in protein science, and we compare nanopores to other single-molecule techniques. We hope to make electrical nanopore sensing more accessible to the biochemical community, and to inspire new creative solutions to resolve a variety of protein dynamics – one molecule at a time.
Performance analysis of M‐ary OQAM/FBMC with impact of nonlinear distortion over compound Rician K‐factor unshadowed/κ−μ shadowed fad ing channels
Authors: Al‐Rubaye Ghanim A.
Published: December 2020

In this paper, the bit error rate (BER) analyses of M‐ary offset QAM for filter bank‐based multicarrier (M‐ary OQAM/FBMC) contaminated by nonlinear distortion (NLD) are investigated over different channel scenarios, such as unshadowed line‐of‐sight (LOS) Rician K‐factor (RK‐f) fading channel, non‐line‐of‐sight (NLOS) shadowed fading model and compound unshadowed/shadowed fading model. NLDs produced by high power amplifier (HPA) play the main role in the degradation of the BER in multicarrier communication systems over fading channels. Therefore, the complex Gaussian noise and the complex NLD are modelled as an independent parameter by using Bussgang's theorem. In this work, closed‐form of BER, ergodic capacity, outage probability and outage capacity probability expressions for the M‐ary OQAM/FBMC system over different unshadowed/shadowed fading channel scenarios and environments with amplitude (AM) and phase (PM) distortion induced by the HPA have been theoretically derived as general expressions without numerical integration method. Extensive Monte‐Carlo simulation results demonstrate a closed agreement with all analytical derived expressions.
Fixed‐time stability of stochastic nonlinear systems and its application into stochastic multi‐agent systems
Authors: Yu Jiaju , Yu Shuanghe , Yan Yan
Published: December 2020

The paper devotes to study fixed‐time stability of stochastic nonlinear systems and fixed‐time consensus of stochastic multi‐agent systems (SMASs). Firstly, a new fixed‐time stability theorem is established and a high‐precise estimation of settling time is provided. Secondly, as an application, the fixed‐time consensus problem of SMASs is discussed in virtue of the established theorem. A new class of fixed‐time nonlinear consensus protocols with stochastic perturbation is designed by employing the neighbour's information. Based on graph theory, matrix theory and fixed‐time stability theorem, we prove that fixed‐time consensus of SMASs is achieved under the designed protocol. Moreover, some sufficient conditions are proposed to guarantee fixed‐time consensus of SMAS. It is shown that the settling time is not only independent of the initial conditions, but also it has higher precise. In the end, three numerical examples are provided to illustrate correctness of our theoretical results.
Optimal feedback path selection for interconnected power systems using load frequency control strategy
Authors: Chowdhury A. Hasib , Rahman Md Mijanur , Hossain Md Alamgir
Published: December 2020

The main goal of an interconnected power system is to transfer power from one area to another while the network frequency and tie‐line flow remain within the prescribed limits. However, both of these quantities may violate their desired values during this transfer due to disturbances in the network. This paper proposes a stratagem for choosing the right feedback path for an interconnected power system to maintain the system frequency and tie‐line flows within the prescribed limits while external disturbances exist. Area control error (ACE), a combination of frequency error and tie‐flow deviations, is used as the performance indicator. In the proposed approach, feedback control is designed using active disturbance rejection controller (ADRC) based load frequency control to tackle ACE. It is observed that the individual load change monitoring is sufficient for selecting the right feedback paths rather than the consideration of simultaneous load changes of all load centres. The effectiveness of the proposed controller for selecting the feedback paths has been tested by conducting several case studies. The results demonstrate that the proposed controller can reduce transient magnitude around 57% for ACE, 55% for frequency error and 72% for tie‐line error as compared to the PID controller.
A simple gated recurrent network for detection of power quality disturbances
Authors: Zu Xiangrong , Wei Kai
Published: December 2020

This paper presents a new concise deep learning–based sequence model to detect the power quality disturbances (PQD), which only uses original signals and does not require pre‐processing and complex artificial feature extraction process. A simple gated recurrent network (SGRN) with a new recurrent cell structure is developed, which consists of only two gates: forget gate and input gate, and two weight matrices. Compared with the standard Recurrent Neural Network (RNN) model, the training process of the proposed method is more stable and the prediction accuracy is higher. In addition, this special structure retains basic non‐linearity and long‐term memory, while enabling the simple gated recurrent network model to be superior to Long Short‐Term Memory (LSTM) Network and Gated Recurrent Unit (GRU) Network in terms of the number of parameters (i.e. memory cost) and detection speed. In the light of the experimental results, the simple gated recurrent network algorithm can achieve 99.07% detection accuracy, and contains only 18,959 parameters, which indicates that our proposed method is easier to deploy in resource‐constrained internet of things (IoT) micro‐controllers.
Characteristics of lightning‐induced voltages based on experimental data
Authors: Santos Michele N. N. , Piantini Alexandre
Published: December 2020

This paper presents an analysis of 64 lightning‐induced voltage waveforms recorded in an experimental system implemented in the campus of the University of São Paulo, Brazil. The voltages were measured on a 10 m high, 2.7 km long un‐energized overhead line consisting of two conductors installed on 6 m crossarms. One of the conductors had surge arresters, while the other one was left unprotected. Strictly speaking, all the recorded voltages on the unprotected conductor were bipolar, but in many cases only one semi‐cycle could be considered important for practical purposes. Different criteria are discussed for the determination of the waveshape parameters, which may differ significantly from those of the standard lightning impulse voltage (1.2/50 μs). Based on the proposed criterion for classifying the induced voltages, unipolar waveforms accounted for 67% of the total and, except for one case, all of them had positive polarity. The median values of the front time and time‐to‐half‐value were, respectively, 5.2 μs and 15.8 μs. Bipolar waveforms were 33% of the total and in approximately 62% of the cases the first semi‐cycle was of positive polarity. In 91% of the cases the voltage peak occurred either in the first or the second semi‐cycle.
Analytical model for the transient permittivity of uncured TiO2 whisker/liquid silicone rubber composites under an AC electric field
Authors: Shen Zikui , Xin Zhenyu , Wang Xilin , Wei Xinyu , Jia Zhidong
Published: December 2020

The electric field grading of dielectric permittivity gradient devices is an effective way of enhancing their insulation properties. The in situ electric field‐driven assembly is an advanced method for the fabrication of insulation devices with adaptive permittivity gradients; however, there is no theoretical guidance for design. In this study, an analytical model with a time constant is developed to determine the transient permittivity of uncured composites under an applied AC electric field. This model is based on optical image and dielectric permittivity monitoring, which avoids the direct processing of complex electrodynamics. For a composite with given components, the increased filler content and electric field strength can accelerate the transient process. Compared with the finite element method based on differential equations, this statistical model is simple but efficient, and can be applied to any low‐viscosity uncured composites, which may contain multiple fillers. More importantly, when a voltage is applied to an uncured composite insulating device, the proposed model can be used to analyse the spatiotemporal permittivity characteristics of this device and optimise its permittivity gradient for electric field grading.
AC interference from faulty power cables on buried pipelines: A two‐step approach
Authors: Lucca Giovanni
Published: December 2020

The purpose of the paper is to describe an algorithm for assessing the 50–60 Hz induced voltage and current, from a power cable in fault condition, on a nearby buried pipeline. The calculation method is a two‐step approach where both the steps are based on the solution of the transmission line model used first to characterize the inducing power cable and then the induced pipeline. The main result to be pointed out is the importance of the conductive coupling, often not considered, when modelling the phenomenon. In fact, neglecting the conductive coupling yields to underestimate the induced voltage and current along the pipeline.
Increasing spin of a B-Star during the common envelope stage
Authors: Staritsin E.
Published: December 2020

Context. In its evolution, the MWC 656 binary system, consisting of a Be star and a black hole, has gone through the common envelope stage. The O and B stars of the early spectral subclasses can be characterised by lower rotational velocities and increased binary frequency. The B star in the MWC 656 system may have undergone rapid rotation during the common envelope stage.

Aims. We study the change in the B star’s state of rotation due to an increase in its angular momentum during the common envelope stage and immediately afterwards.

Methods. We performed one-dimensional numerical calculations of angular momentum transport in the interior of a slightly evolved star on the main sequence with a mass of 16 M⊙. Meridional circulation and shear turbulence are taken into account.

Results. Due to the arrival of angular momentum through the star’s surface, the velocity of the meridional circulation increases by more than six orders of magnitude. Meridional circulation is the main mechanism for the transport of angular momentum into the star’s deep interior. The acquired angular momentum enters the convective core during the common envelope stage if the angular velocity of the accreted matter exceeds half the Kepler value.

Conclusions. The star acquires a rotation typical of classical Be stars if the angular velocity of accreted matter rotation is close to the maximum possible value during the common envelope stage (∼80% of the Kepler value).
Iron in X-COP: Tracing enrichment in cluster outskirts with high accuracy abundance profiles
Authors: Ghizzardi Simona , Molendi Silvano , van der Burg Remco , De Grandi Sabrina , Bartalucci Iacopo , Gastaldello Fabio , Rossetti Mariachiara , Biffi Veronica , Borgani Stefano , Eckert Dominique , Ettori Stefano , Gaspari Massimo , Ghirardini Vittorio , Rasia Elena
Published: December 2020

We present the first metal abundance profiles for a representative sample of massive clusters. Our measurements extend to R500 and are corrected for a systematic error plaguing previous outskirt estimates. Our profiles flatten out at large radii, admittedly not a new result, however the radial range and representative nature of our sample extends its import well beyond previous findings. We find no evidence of segregation between cool-core and non-cool-core systems beyond ∼0.3 R500, implying that, as was found for thermodynamic properties, the physical state of the core does not affect global cluster properties. Our mean abundance within R500 shows a very modest scatter, < 15%, suggesting the enrichment process must be quite similar in all these massive systems. This is a new finding and has significant implications for feedback processes. Together with results from the thermodynamic properties presented in a previous X-COP paper, it affords a coherent picture in which feedback effects do not vary significantly from one system to another. By combining intra-cluster medium with stellar measurements we have found the amount of Fe diffused in the intra-cluster medium to be about ten times higher than that locked in stars. Although our estimates suggest, with some strength, that the measured iron mass in clusters is well in excess of the predicted one, systematic errors prevent us from making a definitive statement. Further advancements will only be possible when systematic uncertainties, principally those associated with stellar masses, both within and beyond R500, can be reduced.
Understanding the radio relic emission in the galaxy cluster MACS J0717.5+3745: Spectral analysis
Authors: Rajpurohit K. , Wittor D. , van Weeren R. J. , Vazza F. , Hoeft M. , Rudnick L. , Locatelli N. , Eilek J. , Forman W. R. , Bonafede A. , Bonnassieux E. , Riseley C. J. , Brienza M. , Brunetti G. , Brüggen M. , Loi F. , Rajpurohit A. S. , Röttgering H. J. A. , Botteon A. , Clarke T. E. , Drabent A. , Domínguez-Fernández P. , Di Gennaro G. , Gastaldello F.
Published: December 2020

Radio relics are diffuse, extended synchrotron sources that originate from shock fronts generated during cluster mergers. The massive merging galaxy cluster MACS J0717.5+3745 hosts one of the more complex relics known to date. We present upgraded Giant Metrewave Radio Telescope band 3 (300−500 MHz) and band 4 (550−850 MHz) observations. These new observations, combined with published VLA and the new LOFAR HBA data, allow us to carry out a detailed, high spatial resolution spectral analysis of the relic over a broad range of frequencies. The integrated spectrum of the relic closely follows a power law between 144 MHz and 5.5 GHz with a mean spectral slope α = −1.16 ± 0.03. Despite the complex morphology of this relic, its subregions and the other isolated filaments also follow power-law behaviors, and show similar spectral slopes. Assuming diffusive shock acceleration, we estimated a dominant Mach number of ∼3.7 for the shocks that make up the relic. A comparison with recent numerical simulations suggests that in the case of radio relics, the slopes of the integrated radio spectra are determined by the Mach number of the accelerating shock, with α nearly constant, namely between −1.13 and −1.17, for Mach numbers 3.5 − 4.0. The spectral shapes inferred from spatially resolved regions show curvature, we speculate that the relic is inclined along the line of sight. The locus of points in the simulated color-color plots changes significantly with the relic viewing angle. We conclude that projection effects and inhomogeneities in the shock Mach number dominate the observed spectral properties of the relic in this complex system. Based on the new observations we raise the possibility that the relic and a narrow-angle-tailed radio galaxy are two different structures projected along the same line of sight.
Evolution of a streamer-blowout CME as observed by imagers on Parker Solar Probe and the Solar Terrestrial Relations Observatory
Authors: Liewer P. C. , Qiu J. , Vourlidas A. , Hall J. R. , Penteado P.
Published: December 2020

Context. On 26–27 January 2020, the Wide-field Imager for Solar Probe on Parker Solar Probe (PSP) observed a coronal mass ejection (CME) from a distance of approximately 30 R⊙ as it passed through the instrument’s 95° field-of-view, providing an unprecedented view of the flux rope morphology of the CME’s internal structure. The same CME was seen by Solar Terrestrial Relations Observatory-Ahead (STEREO-A), beginning on 25 January.

Aims. Our goal is to understand the origin and determine the trajectory of this CME.

Methods. We analyzed data from three well-placed spacecrafts: PSP, STEREO-A, and Solar Dynamics Observatory (SDO). The CME trajectory was determined using a tracking-and-fitting technique and verified using simultaneous images of the CME propagation from STEREO-A. The fortuitous alignment with STEREO-A also provided views of coronal activity leading up to the eruption. Observations from SDO, in conjunction with potential magnetic field models of the corona, were used to analyze the coronal magnetic evolution for the three days leading up to the flux rope ejection from the corona on 25 January.

Results. We found that the 25 January CME is likely the end result of a slow magnetic flux rope eruption that began on 23 January and was observed by STEREO-A/Extreme Ultraviolet Imager. The analysis of these observations suggest that the flux rope was apparently constrained in the corona for more than a day before its final ejection on 25 January. STEREO-A/COR2 observations of swelling and brightening of the overlying streamer for several hours prior to eruption on 25 January led us to classify this as a streamer-blowout CME. The analysis of the SDO data suggests that restructuring of the coronal magnetic fields caused by an emerging active region led to the final ejection of the flux rope.
Resonance track‐and‐dwell testing for crack length measurement on 304L stainless steel
Authors: Gautrelet Christophe , Khalij Leila , Machado Marcela Rodrigues
Published: December 2020

Experimental vibration-fatigue tests were conducted with sine resonance track‐and‐dwell (SRTD) tool by using an electrodynamic shaker on specimens made of 304L stainless steel. Due to cyclic fatigue resulting in stiffness loss, it can be found that the resonant frequency decreases when the specimen experiences substantial crack growth, especially for out-of-plane bending mode. The specimens were equipped by a crack propagation gauge (CPG) to monitor the crack growth. However, the presence of crack was detected late by these gauges. The deviation of the resonance frequency was therefore analysed from the time response measurements, and the results were confronted to the CPG measurements to conclude on the validity of the detection threshold provided by the literature.
Deep Learning CT Image Reconstruction in Clinical Practice
Authors: Arndt Clemens , Güttler Felix , Heinrich Andreas , Bürckenmeyer Florian , Diamantis Ioannis , Teichgräber Ulf
Published: December 2020

Background Computed tomography (CT) is a central modality in modern radiology contributing to diagnostic medicine in almost every medical subspecialty, but particularly in emergency services. To solve the inverse problem of reconstructing anatomical slice images from the raw output the scanner measures, several methods have been developed, with filtered back projection (FBP) and iterative reconstruction (IR) subsequently providing criterion standards. Currently there are new approaches to reconstruction in the field of artificial intelligence utilizing the upcoming possibilities of machine learning (ML), or more specifically, deep learning (DL).

Method This review covers the principles of present CT image reconstruction as well as the basic concepts of DL and its implementation in reconstruction. Subsequently commercially available algorithms and current limitations are being discussed.

Results and Conclusion DL is an ML method that utilizes a trained artificial neural network to solve specific problems. Currently two vendors are providing DL image reconstruction algorithms for the clinical routine. For these algorithms, a decrease in image noise and an increase in overall image quality that could potentially facilitate the diagnostic confidence in lesion conspicuity or may translate to dose reduction for given clinical tasks have been shown. One study showed equal diagnostic accuracy in the detection of coronary artery stenosis for DL reconstructed images compared to IR at higher image quality levels. Consequently, a lot more research is necessary and should aim at diagnostic superiority in the clinical context covering a broadness of pathologies to demonstrate the reliability of such DL approaches.

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Continuous Glucose Monitoring for Glycemic Control in Children and
Adolescents Diagnosed with Diabetes Type 1: A Systematic Review and
Meta-Analysis
Authors: Dorando Elena , Haak Thomas , Pieper Dawid
Published: December 2020

Aim The aim of this meta-analysis was to evaluate the impact of
continuous glucose monitoring (CGM) systems on short- and long-term glycemic
control in children and adolescents diagnosed with diabetes type 1.

Methods The review was registered in PROSPERO (CRD42019135152). We partly
updated a formerly published systematic review and searched several databases
(Ovid MEDLINE, Embase, CENTRAL, and Clinicaltrials.gov) in May 2019. Summary
measures were estimated as relative risks (RR) and standardized mean differences
(SMD). The primary endpoint of our analysis was frequency of hypoglycemic
events. Quality of evidence was evaluated using the GRADE approach.

Results Eleven studies with a total number of 818 patients were included
in our review. Meta-analyses indicated a potential benefit of CGM systems
regarding the relative risk of a severe hypoglycemic event (RR 0.78; 95%
CI 0.29 to 2.04) and mean level of HbA1c at end of study (SMD -0.23; 95%
CI -0.46 to 0.00). Certainty of evidence for effect estimates of these
meta-analyses was low due to risk of selection bias and imprecision of the
included studies. Qualitative analyses of the secondary outcomes of user
satisfaction and long-term development of blood glucose supported these
findings.

Conclusion CGM systems may improve glycemic control in children and
adolescents diagnosed with diabetes type 1, but the imprecision of effects is
still a problem. Only a few studies examined and reported data for pediatric
populations in sufficient detail. Further research is needed to clarify
advantages and disadvantages of CGM systems in children and adolescents.
Die allgemeine und spezialisierte Palliativversorgung aus Sicht von Leistungserbringern der Hospiz- und Palliativversorgung – eine Querschnittserhebung
Authors: Rehner Laura , Moon Kilson , Hoffmann Wolfgang , Berg Neeltje van den
Published: December 2020

Hintergrund Die Palliativ- und Hospizversorgung stellt in ländlichen Regionen mit einer geringen Bevölkerungsdichte eine besondere Herausforderung dar. Jeder Patient soll unabhängig von Alter, Diagnose, Prognose, Wohnort und wirtschaftlichen Aspekten Zugang zur Palliativ- und Hospizversorgung erhalten. Ziel war es, Problembereiche in der Palliativ- und Hospizversorgung in ländlichen Regionen zu identifizieren und mögliche Lösungsoptionen aus Sicht der Leistungserbringer zu erfahren.

Methodik Es wurde eine standardisierte schriftliche Befragung unter Leistungserbringern der allgemeinen und spezialisierten Palliativversorgung in Mecklenburg-Vorpommern (MV) durchgeführt. Insgesamt wurden 489 Fragebögen versendet. Kontaktiert wurde eine zufällige Stichprobe an Leistungserbringer der allgemeinen Palliativversorgung und alle Leistungserbringer der spezialisierten Palliativversorgung in MV. Für die Ermittlung von Problembereichen konnten die Strukturen der Palliativ- und Hospizversorgung mittels des deutschen Schulnotensystems bewertet werden (1=sehr gut; 6=ungenügend). Die Auswertung des Fragebogens erfolgte deskriptiv.

Ergebnisse Der Rücklauf betrug 19% (n=93). Problembereiche wurden an den Schnittstellen zwischen den ambulanten und stationären Sektoren sowie zwischen der allgemeinen und spezialisierten Palliativversorgung und der Hospizversorgung identifiziert. Die Zusammenarbeit zwischen SAPV-Teams und Krankenhäusern mit Palliativstation wurde im Mittel mit 1,9 bewertet. Die Zusammenarbeit zwischen SAPV-Teams und Krankenhäusern ohne Palliativstation erhielt im Mittel die Note 3,6. Das Wissen zu Palliative Care von Pflegenden in stationären Pflegeeinrichtungen erhielt von den Teilnehmenden die Schulnote 4,0. Eine telemedizinische Versorgung als Ergänzung zur herkömmlichen Versorgung von Palliativpatienten können sich 54,8% (n=51) der Teilnehmenden vorstellen. Die Einrichtung einer Koordinierungsstelle für die Palliativ- und Hospizversorgung wurde von 34,4% der Befragten als sehr wichtig bewertet.

Schlussfolgerungen Die Ergebnisse deuten auf infrastrukturelle, organisatorische und qualitätsbezogene Probleme in der Palliativ- und Hospizversorgung in MV hin. Die Versorgung in ländlichen Regionen könnte durch Fort- und Weiterbildungen zu Palliative Care, Hospizarbeit und Palliativmedizin sowie durch palliativmedizinische Konsiliardienste, Koordinierungsstellen und telemedizinische Funktionalitäten gestärkt werden.
Multiparametric MRI in the Diagnosis of Prostate Cancer: Physical Foundations, Limitations, and Prospective Advances of Diffusion-Weighted MRI
Authors: Wichtmann Barbara Daria , Zöllner Frank Gerrit , Attenberger Ulrike Irmgard , Schönberg Stefan O.
Published: December 2020

Background Diffusion-weighted imaging (DWI) is an essential component of the multiparametric MRI exam for the diagnosis and assessment of prostate cancer (PCa). Over the last two decades, various models have been developed to quantitatively correlate the DWI signal with microstructural characteristics of prostate tissue. The simplest approach (ADC: apparent diffusion coefficient) – currently established as the clinical standard – describes monoexponential decay of the DWI signal. While numerous studies have shown an inverse correlation of ADC values with the Gleason score, the ADC model lacks specificity and is based on water diffusion dynamics that are not true in human tissue. This article aims to explain the biophysical limitations of the standard DWI model and to discuss the potential of more complex, advanced DWI models.

Methods This article is a review based on a selective literature review.

Results Four phenomenological DWI models are introduced: diffusion tensor imaging, intravoxel incoherent motion, biexponential model, and diffusion kurtosis imaging. Their parameters may potentially improve PCa diagnostics but show varying degrees of statistical significance with respect to the detection and characterization of PCa in current studies. Phenomenological model parameters lack specificity, which has motivated the development of more descriptive tissue models that directly relate microstructural features to the DWI signal. Finally, we present two of such structural models, i. e. the VERDICT (Vascular, Extracellular, and Restricted Diffusion for Cytometry in Tumors) and RSI (Restriction Spectrum Imaging) model. Both have shown promising results in initial studies regarding the characterization and prognosis of PCa.

Conclusion Recent developments in DWI techniques promise increasing accuracy and more specific statements about microstructural changes of PCa. However, further studies are necessary to establish a standardized DWI protocol for the diagnosis of PCa.

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Enhanced dielectric permittivity and relaxor behavior in thermally annealed P(VDF-TrFE) copolymer films
Authors: Nayak S. , Ng Ho Tin , Pramanick A.
Published: December 2020

Modification of relaxor behavior and large enhancement in dielectric permittivity are demonstrated in a P(VDF-TrFE) ferroelectric polymer film by thermal annealing treatment. For coexisting normal ferroelectric and relaxor behavior in P(VDF-TrFE) (molar ratio: 45:55) films, the relative contribution from the relaxor component is increased when annealed at high temperature and subsequently quenched. A relative peak permittivity of ε′ ∼ 100 is obtained for an annealing temperature of T = 90 °C, which is one of the highest reported so far among poly(vinylidene fluoride) copolymer and terpolymer films. Based on x-ray diffraction analysis, we attribute the changes in dielectric properties to a decrease in crystallite domain size and a consequent increase in the crystalline-amorphous interfacial area.
Multi-branched resonances, chaos through quasiperiodicity, and asymmetric states in a superconducting dimer
Authors: Shena J. , Lazarides N. , Hizanidis J.
Published: December 2020

A system of two identical superconducting quantum interference devices (SQUIDs) symmetrically coupled through their mutual inductance and driven by a sinusoidal field is investigated numerically with respect to dynamical properties such as its multibranched resonance curve, its bifurcation structure and transition to chaos as well as its synchronization behavior. The SQUID dimer is found to exhibit a hysteretic resonance curve with a bubble connected to it through Neimark–Sacker (torus) bifurcations, along with coexisting chaotic branches in their vicinity. Interestingly, the transition of the SQUID dimer to chaos occurs through a torus-doubling cascade of a two-dimensional torus (quasiperiodicity-to-chaos transition). Periodic, quasiperiodic, and chaotic states are identified through the calculated Lyapunov spectrum and illustrated using Lyapunov charts on the parameter plane of the coupling strength and the frequency of the driving field. The basins of attraction for chaotic and non-chaotic states are determined. Bifurcation diagrams are constructed on the parameter plane of the coupling strength and the frequency of the driving field, and they are superposed to maps of the three largest Lyapunov exponents on the same plane. Furthermore, the route of the system to chaos through torus-doubling bifurcations and the emergence of Hénon-like chaotic attractors are demonstrated in stroboscopic diagrams obtained with varying driving frequency. Moreover, asymmetric states that resemble localized synchronization have been detected using the correlation function between the fluxes threading the loop of the SQUIDs.
First-principles quantum Monte Carlo studies for prediction of double minima for positronic hydrogen molecular dianion
Authors: Ito Shumpei , Yoshida Daisuke , Kita Yukiumi , Tachikawa Masanori
Published: December 2020

We studied the positron (e+) interaction with the hydrogen molecular dianion H22− to form the positronic bound state of [H−; e+; H−] using the first-principles quantum Monte Carlo method combined with the multi-component molecular orbital one. H22− itself is unstable, but it was shown that such an unbound H22− may become stable by intermediating a positron and forming the positronic covalent bond of the [H−; e+; H−] system [J. Charry et al., Angew. Chem., Int. Ed. 57, 8859–8864 (2018)]. We newly found that [H−; e+; H−] has double minima containing another positronic bound state of [H2; Ps−]-like configuration with the positronium negative ion Ps− at the bond distance approximately equal to the equilibrium H2 molecule. Our multi-component variational Monte Carlo calculation and the multi-component configuration interaction one resulted in the positronic covalent bonded structure being the global minimum, whereas a more sophisticated multi-component diffusion Monte Carlo calculation clearly showed that the [H2; Ps−]-like structure at the short bond distance is energetically more stable than the positronic covalent bonded one. The relaxation due to interparticle correlation effects pertinent to Ps− (or Ps) formation is crucial for the formation of the Ps−A2-like structure for binding a positron to the non-polar negatively charged dihydrogen.
Theoretical analysis and experimental investigation on a linear ultrasonic motor with a compact slider
Authors: Dai Shichao , Yao Zhiyuan , Zhou Lifeng , He Ying
Published: December 2020

A compact slider for linear ultrasonic motors (LUMs) to improve the ability of LUMs for precision positioning is proposed in this article. The compact slider can avoid the effect of variable stiffness of the traditional slider on ultra-precision positioning, which consists of two pieces of ceramic with little lubricating oil on the sliding interface. Based on contact theory and lubrication theory, the contact mechanism and the lubricating state between the slider and the support plate are analyzed. Subsequently, a dynamic model for LUMs considering the lubricating state and the ultrasonic vibration condition is obtained. Furthermore, the output speed and output force of the motor are analyzed under the influence of film lubrication. Moreover, some experiments are designed to test the feasibility and effectiveness of the compact slider for precision positioning. The results indicate that the compact slider is more effective in inhibiting the fluctuation of the output speed compared to the traditional slider, and it can improve the displacement resolution of LUMs up to 7 nm.
Experimental parameters, combined dynamics, and nonlinearity of a magnonic-opto-electronic oscillator (MOEO)
Authors: Xiong Yuzan , Zhang Zhizhi , Li Yi , Hammami Mouhamad , Sklenar Joseph , Alahmed Laith , Li Peng , Sebastian Thomas , Qu Hongwei , Hoffmann Axel , Novosad Valentine , Zhang Wei
Published: December 2020

We report the construction and characterization of a comprehensive magnonic-opto-electronic oscillator (MOEO) system based on 1550-nm photonics and yttrium iron garnet (YIG) magnonics. The system exhibits a rich and synergistic parameter space because of the ability to control individual photonic, electronic, and magnonic components. Taking advantage of the spin wave dispersion of YIG, the frequency self-generation as well as the related nonlinear processes becomes sensitive to the external magnetic field. Besides being known as a band-pass filter and a delay element, the YIG delay line possesses spin wave modes that can be controlled to mix with the optoelectronic modes to generate higher-order harmonic beating modes. With the high sensitivity and external tunability, the MOEO system may find usefulness in sensing applications in magnetism and spintronics beyond optoelectronics and photonics.
Predicting critical transitions in multiscale dynamical systems using reservoir computing
Authors: Lim Soon Hoe , Theo Giorgini Ludovico , Moon Woosok , Wettlaufer J. S.
Published: December 2020

We study the problem of predicting rare critical transition events for a class of slow–fast nonlinear dynamical systems. The state of the system of interest is described by a slow process, whereas a faster process drives its evolution and induces critical transitions. By taking advantage of recent advances in reservoir computing, we present a data-driven method to predict the future evolution of the state. We show that our method is capable of predicting a critical transition event at least several numerical time steps in advance. We demonstrate the success as well as the limitations of our method using numerical experiments on three examples of systems, ranging from low dimensional to high dimensional. We discuss the mathematical and broader implications of our results.
3,5-Anthryl–Bodipy dyad/triad: Preparation, effect of F–B–F induced conformation restriction on the photophysical properties, and application in triplet–triplet-annihilation upconversion
Authors: Hu Yingqi , Hou Yuqi , Wang Zhijia , Li Yanqin , Zhao Jianzhang
Published: December 2020

We prepared a series of compact Bodipy–anthryl electron donor/acceptor triads and dyads by attaching anthryl moieties at the 3-,5-positions of the Bodipy core, with a novel conformation restriction approach, to study the spin–orbit charge transfer intersystem crossing (SOCT-ISC). The conformation restrictions are imposed by the BF2 unit of Bodipy without invoking the previously reported method with 1,7-dimethyl or 1,3-dimethyl groups. Our new approach shows a few advantages, including the stronger electron accepting ability of the methyl-free Bodipy core (reduction potential anodically shifted by +0.3 V vs the methylated Bodipy), red-shifted absorption (by 21 nm), and longer triplet state lifetime (372 µs vs 126 µs). The effects of the different mutual orientations of the electron donor and acceptor on ultraviolet–visible absorption, fluorescence, triplet state quantum yields, and lifetimes were studied. Triads with orthogonal geometries show higher singlet oxygen quantum yields (ΦΔ = 37%) than those with more coplanar geometries. Since the non-radiative decay for the S1 state is significant in the parent Bodipy chromophore (ΦF = 6.0%), we propose that in dyads/triads, the charge separation and recombination-induced ISC outcompete the non-radiative decay to the ground state, which is new in the study of SOCT-ISC. Density functional theory computation indicated a shallow torsion potential energy curve as compared to the meso-anthryl–Bodipy dyad analog, which may contribute a low triplet state quantum yield of the new dyads/triads. Triplet–triplet annihilation upconversion was performed with the electron donor/acceptor dyads as the triplet photosensitizer, with an upconversion quantum yield of 12.3%.
Thermocapillary motion of a solid cylinder near a liquid–gas interface
Authors: Arslanova A. , Natale G. , Reddy N. , Clasen C. , Fransaer J.
Published: December 2020

The motion of a solid, infinitely long cylinder perpendicular to a convective liquid–gas interface due to thermocapillarity is investigated via an analytical model. If the cylinder temperature differs from the bulk temperature, a temperature gradient exists along the liquid–gas interface. This results in surface tension gradients at the liquid–gas interface, causing fluid flow around the particle, which induces propulsion. For small particles and, thus, small Péclet and Reynolds numbers, the steady-state equations for temperature and flow fields are solved exactly using two-dimensional bipolar cylindrical coordinates. The velocity of the cylinder as a function of separation distance from the liquid–gas interface is determined for the case of a constant temperature or a constant heat flux on the surface of the cylinder. A larger temperature gradient at the liquid–gas interface in the latter system leads to a larger cylinder velocity and a higher propulsion efficiency. The thermocapillary effect results in larger force on a cylinder than forces arising from other self-propulsion mechanisms.
On the quantum origin of few response properties
Authors: Millán Leonardo A. , Giribet Claudia G. , Aucar Gustavo A.
Published: December 2020

In modern physics, the entanglement between quantum states is a well-established phenomenon. Going one step forward, one can conjecture the likely existence of an entanglement between excitations of one-particle quantum states. Working with a density matrix that is well defined within the polarization propagator formalism, together with information theory, we found that the quantum origin of, at least, few molecular response properties can be described by the entanglement between two pairs of virtual excitations of molecular orbitals (MOs). With our model, we are able to bring new insights into the electronic mechanisms that are behind the transmission, and communication, of the effects of a given perturbation to the whole electronic system described by the Hamiltonian of an unperturbed quantum system. With our entanglement model, we analyzed the electronic origin of the Karplus rule of nuclear magnetic resonance spectroscopy, a well-known empirical phenomenon, and found that this rule is straightforwardly related to the behavior of entangled MO excitations. The model compound used to show it is the H2O2 molecule.
Formulation, printing, and poling method for piezoelectric films based on PVDF–TrFE
Authors: McGinn Christine K. , Kam Kevin A. , Laurila Mika-Matti , Lozano Montero Karem , Mäntysalo Matti , Lupo Donald , Kymissis Ioannis
Published: December 2020

Polyvinylidene fluoride- trifluoroethylene (PVDF–TrFE) has been utilized widely for pressure sensing, healthcare monitoring, and energy harvesting. In order to integrate piezoelectric elements into flexible thin film electronics, researchers have studied depositing PVDF–TrFE via printing methods. Screen printing, in particular, has been utilized by several groups but printing methodology and characterization procedures have varied significantly between works. In this work, a simple, low-cost, flexible method is described. The resulting films are characterized for their piezoelectric character and temperature tolerance. The printed films have a piezoelectric coefficient comparable to previous work (26.24 pC/N) and demonstrate no meaningful degradation in piezoelectric character up to 110C.
Second generation readout for large format photon counting microwave kinetic inductance detectors
Authors: Fruitwala Neelay , Strader Paschal , Cancelo Gustavo , Zmuda Ted , Treptow Ken , Wilcer Neal , Stoughton Chris , Walter Alex B. , Zobrist Nicholas , Collura Giulia , Lipartito Isabel , Bailey John I. , Mazin Benjamin A.
Published: December 2020

We present the development of a second generation digital readout system for photon counting microwave kinetic inductance detector (MKID) arrays operating in the optical and near-infrared wavelength bands. Our system retains much of the core signal processing architecture from the first generation system but with a significantly higher bandwidth, enabling the readout of kilopixel MKID arrays. Each set of readout boards is capable of reading out 1024 MKID pixels multiplexed over 2 GHz of bandwidth; two such units can be placed in parallel to read out a full 2048 pixel microwave feedline over a 4 GHz–8 GHz band. As in the first generation readout, our system is capable of identifying, analyzing, and recording photon detection events in real time with a time resolution of order a few microseconds. Here, we describe the hardware and firmware, and present an analysis of the noise properties of the system. We also present a novel algorithm for efficiently suppressing IQ mixer sidebands to below −30 dBc.