bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of robust and low‐loss 3‐D printed double‐ridged waveguide to microstrip transition
Authors: Eriksrød Jon Håvard H. , Kjelgård Kristian G. , Lande Tor S. 
Published: February 2022

AbstractIn this paper, we present a new microstrip to waveguide transition design for interfacing printed circuit board (PCB) microstrip transmission lines with 3‐D printed metallised‐plastic waveguide components. Compared with traditional metal waveguides, interfacing with plastic‐based waveguides are challenging due to thermal and mechanical constraints. Despite the development of 3‐D printing technology, the precision of 3‐D printed waveguides is not as good as the machined metal counterparts. This is critical for microwave components and must be considered in the design process. To minimise the effect of non‐ideal waveguide components, a design methodology minimising sensitivity to geometrical variations in the 3‐D printed parts is proposed. By sandwiching the PCB between two waveguide sections and optimising the waveguide impedance transformation geometry, the design shows very low insertion loss. It is mechanically robust, cost effective and simple to manufacture. In full system integration, this transition design eliminates the need for expensive microwave cabling and connectors by directly mounting the waveguide to the microwave transceiver PCB. The proof‐of‐concept transition structure presented in this paper is suitable for microwave applications where low cost and low weight are critical, for example, drone‐based radars for remote sensing and space‐born satellites. The fabricated structure is characterised using two sets of waveguide components manufactured with different 3‐D printing technology and metallisation process': conductive spray painted Fused Deposition Modelling—Polylactic Acid (PLA Painted) and copper electroplated Stereolithography (SLA Plated). Scattering parameters for both types are measured in a short and back‐to‐back configuration, obtaining the reflection coefficient and insertion loss. Measurements indicate good agreement with modelling and measured performance exceeding prior art. The measured operation band of the Copper‐SLA version is 2.9–7.2 GHz with <−10 dB reflection coefficient (S11) and with an insertion loss (S21) of <0.7 dB. With the reduced metallisation and surface quality of the Spray‐PLA model, the band is shifted to 3.0–8.0 GHz with an increased S21 of <1.8 dB. The results demonstrate the importance of adopting new transition structures for 3‐D printed microwave components where the surface roughness, metallisation quality, and mechanical properties are less optimal. By combining the proposed design with 3‐D printed metallised microwave components, very light weight and cost‐effective antenna systems can be implemented. Radiation measurements of a 3‐D printed double ridge horn antenna connected to the waveguide and used as a feed are also presented, where the operation band is measured to 3–10 GHz with a gain of 5–10 dBi.
Phase‐shifted metasurface design for pseudo‐nondiffractive beam deflection
Authors: Yang Xiaoqing , Chen Tiantian , Lu Ping , Zou Ying , Li Weize , Liu Qian 
Published: February 2022

AbstractA transmission phase‐shifted metasurface (PSM) array has been proposed for non‐diffractive beam deflection. A PSM element consists of two identical semicircular rings and an I‐shaped structure, which is symmetrically printed on both sides of the F4B substrate. According to the geometric optics, the phase distribution on the metasurface can be obtained. To achieve the desired phase distribution, the metasurface elements rotated at different angles are rearranged, since the phase of the transmitted wave is manipulated by rotating the metasurface element. Then, the standard horn is used to produce the sphere wave across the proposed metasurface array for the non‐diffractive beam deflection. Simulated (measured) results show that the inclined non‐diffractive beam can be generated at a tilted angle of 35° (34.9°) with a maximum non‐diffractive distance of 100 mm (97.5 mm) at 10 GHz. The proposed metasurface array has the advantages of non‐diffractive beam deflection, low sidelobes and miniaturisation.
EMD/HT‐based local fault detection in DC microgrid clusters
Authors: Bayati Navid , Baghaee Hamid Reza , Savaghebi Mehdi , Hajizadeh Amin , Soltani Mohsen , Lin Zhengyu 
Published: February 2022

AbstractDC faults can create serious damages if not detected and isolated in a short time. This paper proposes a fault detection technique for DC faults to enhance the protection of DC microgrid clusters. To detect such faults accurately and quickly, a DC fault detection scheme using empirical mode decomposition and Hilbert transform is proposed. Due to the strict time limits for fault interruption caused by fast high‐rising fault currents in DC systems, DC microgrid clusters' protection remains a challenging task. Furthermore, high impedance faults (HIFs) in DC systems cause a small change in the current, which can damage the power electronic converters if not detected in time. Therefore, this paper proposes a local scheme for the fast detection of faults including HIFs in DC microgrid clusters. Both simulation and experimental results using a scaled DC microgrid cluster prototype and considering several scenarios (such as low impedance faults, HIFs, noise, overload, and bad calibration of sensors) demonstrate the successful and fast detection (less than 2 ms) of DC faults by the proposed method. Compared with other techniques, the proposed scheme presents its merits from the viewpoints of accuracy and speed.
Precise radial velocities of giant stars
Authors: Wolthoff Vera , Reffert Sabine , Quirrenbach Andreas , Jones Matías I. , Wittenmyer Robert A. , Jenkins James S. 
Published: February 2022

Context. Radial velocity surveys of evolved stars allow us to probe a higher stellar mass range, on average, compared to main-sequence samples. Hence, differences between the planet populations around the two target classes can be caused by either the differing stellar mass or stellar evolution. To properly disentangle the effects of both variables, it is important to characterize the planet population around giant stars as accurately as possible.
Aims. Our goal is to investigate the giant planet occurrence rate around evolved stars and determine its dependence on stellar mass, metallicity, and orbital period.
Methods. We combine data from three different radial velocity surveys targeting giant stars: the Lick giant star survey, the radial velocity program EXoPlanets aRound Evolved StarS (EXPRESS), and the Pan-Pacific Planet Search (PPPS), yielding a sample of 482 stars and 37 planets. We homogeneously rederived the stellar parameters of all targets and accounted for varying observational coverage, precision and stellar noise properties by computing a detection probability map for each star via injection and retrieval of synthetic planetary signals. We then computed giant planet occurrence rates as a function of period, stellar mass, and metallicity, corrected for incompleteness.
Results. Our findings agree with previous studies that found a positive planet-metallicity correlation for evolved stars and identified a peak in the giant planet occurrence rate as a function of stellar mass, but our results place it at a slightly smaller mass of (1.68 ± 0.59) M⊙. The period dependence of the giant planet occurrence rate seems to follow a broken power-law or log-normal distribution peaking at (718 ± 226) days or (797 ± 455) days, respectively, which roughly corresponds to 1.6 AU for a 1 M⊙ star and 2.0 AU for a 2 M⊙ star. This peak could be a remnant from halted migration around intermediate-mass stars, caused by stellar evolution, or an artifact from contamination by false positives. The completeness-corrected global occurrence rate of giant planetary systems around evolved stars is 10.7%−1.6%+2.2% for the entire sample, while the evolutionary subsets of RGB and HB stars exhibit 14.2%−2.7%+4.1% and 6.6%−1.3%+2.1%, respectively. However, both subsets have different stellar mass distributions and we demonstrate that the stellar mass dependence of the occurrence rate suffices to explain the apparent change of occurrence with the evolutionary stage.
Echinococcosis: a Challenge for Liver Sonography
Authors: Kratzer Wolfgang , Weimer Henriette , Schmidberger Julian 
Published: February 2022

AbstractThe sonographic findings in alveolar echinococcosis (AE) and cystic echinococcosis (CE) are complex and can pose significant differential diagnostic problems. They may present like complicated cysts or malignant tumors in the liver. We will discuss the diagnostic difficulties and pitfalls of these two diseases based on case histories.
Availability of Interventional Oncology in Germany in the Years 2018 and 2019 – Results from a Nationwide Database (DeGIR Registry Data)
Authors: Radosa Christoph Georg , Nadjiri Jonathan , Mahnken Andreas H. , Bücker Arno , Heuser Lothar J , Morhard Dominik , Landwehr Peter , Berlis Ansgar , Katoh Marcus , Reimer Peter , Schachtner Balthasar , Ingrisch Michael , Paprottka Philipp , Hoffmann Ralf-Thorsten 
Published: February 2022

Objective Over the past few decades, radiology has established itself in tumor therapy through interventional oncology including innovative and efficient procedures for minimalinvasive treatment of various tumor entities besides the “classic” therapeutic options such as surgery, chemotherapy and radiotherapy.Aim of this study was to evaluate the extent to which interventional oncology can provide nationwide care using the data from the register of the German Society for Interventional Radiology and Minimally Invasive Therapy (DeGIR registry), which records radiological interventions as part of quality assurance.
Methods The numbers of interventions of participating clinics, which were recorded as part of module D (oncological procedures including TACE or other tumor-specific embolization, ablation, percutaneous tumor therapy) and identified by the DeGIR registry between 2018 and 2019, were analyzed retrospectively. The collected intervention data were evaluated regarding federal states and 40 smaller regions (administrative districts and former administrative districts).
Results In 2018, 11 653 oncological interventions in 187 clinics were recorded by the DeGIR registry. In 2019, the number of participating clinics rose to 216 and the number of oncological interventions increased by 6 % to 12 323. The average number of oncological interventions per clinic decreased slightly from 62.5 (2018) to 57.1 (2019). The DeGIR requirement for being certified as a training center was met by 116 clinics in 2018 including 31 clinics with more than 100 interventions and 129 clinics in 2019 including 36 with more than 100 interventions. Oncological interventions have been performed in each of the 40 regions. An average of 599 interventions per region (standard deviation of 414) was recorded in the period between 2018 and 2019.
Conclusion Based on the distribution of the documented oncological interventions at federal state level as well as the district level, the supply of interventional tumor therapy depends on the geographical location. Therefore, the demand of oncological interventions might not be sufficiently covered in some regions.
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Nutzung und Adhärenz digitaler Angebote durch Patienten und Ärzte – unter Berücksichtigung des Alters
Authors: Grahammer Manuel , Sewerin Philipp 
Published: February 2022

ZUSAMMENFASSUNGDie Digitalisierung des deutschen Gesundheitswesens schreitet stetig voran. Vielfältige digitale Gesundheitsangebote stehen dabei für verschiedene Indikationen und immer mehr Gruppen an Nutzer*innen zur Verfügung. Vermehrt wird sich daher mit der Adhärenz bei solchen digitalen Technologien auseinandergesetzt, die man als effektive Nutzung einer digitalen Anwendung oder Technologie gemäß den Vorgaben und Anleitungen der Hersteller*innen definieren kann. Diese digitale Adhärenz wird von einer Vielzahl an Faktoren beeinflusst. Betrachtet man insbesondere das Alter der Nutzer*innen, so zeigt sich, dass dieser Faktor weder einen generell-negativen noch generell-positiven signifikanten Einfluss auf die Adhärenz hat. Für eine hohe Adhärenz ist es wichtig, dass Entwickler*innen digitale Technologien nutzerorientiert konzipieren und die individuellen Bedürfnisse einzelner Nutzer*innen berücksichtigen. Aktuelle Forschung in der Rheumatologie beschäftigt sich ebenfalls mit digitalen Gesundheitsangeboten, in denen großes Potenzial für eine bessere und effizientere Versorgung liegt, sowie mit der Adhärenz dieser Angebote. Dabei zeigt sich eine große Bereitschaft zur Nutzung digitaler Technologien, unter anderem auch bei älteren Nutzer*innen. Dieser Artikel gibt einen Überblick über Nutzung und Adhärenz digitaler Gesundheitsangebote unter besonderer Berücksichtigung des Alters der Nutzer*innen und betrachtet die Implikationen für die Rheumatologie als Fachbereich.
Applicability of CO-RADS in an Anonymized Cohort Including Early and Advanced Stages of COVID-19 in Comparison to the Recommendations of the German Radiological Society and Radiological Society of North America
Authors: Valentin Birte , Steuwe Andrea , Wienemann Tobias , Andree Marcel , Keitel Verena , Ljimani Alexandra , Appel Elisabeth , Köhler Marie-Helen , Rademacher Christin , Aissa Joel , Antoch Gerald , Loberg Christina 
Published: February 2022

Purpose Classifications were created to facilitate radiological evaluation of the novel coronavirus disease 2019 (COVID-19) on computed tomography (CT) images. The categorical CT assessment scheme (CO-RADS) categorizes lung parenchymal changes according to their likelihood of being caused by SARS-CoV-2 infection. This study investigates the diagnostic accuracy of diagnosing COVID-19 with CO-RADS compared to the Thoracic Imaging Section of the German Radiological Society (DRG) classification and Radiological Society of North America (RSNA) classification in an anonymized patient cohort. To mimic advanced disease stages, follow-up examinations were included as well.
Method This study includes all patients undergoing chest CT in the case of a suspected SARS-CoV-2 infection or an already confirmed infection between March 13 and November 30, 2020. During the study period, two regional lockdowns occurred due to high incidence values, increasing the pre-test probability of COVID-19. Anonymized CT images were reviewed retrospectively and in consensus by two radiologists applying CO-RADS, DRG, and RSNA classification. Afterwards, CT findings were compared to results of sequential real-time reverse transcriptase polymerase chain reaction (qPCR) test performed during hospitalization to determine statistical analysis for diagnosing COVID-19.
Results 536 CT examinations were included. CO-RADS, DRG and RSNA achieved an NPV of 96 %/94 %/95 % (CO-RADS/DRG/RSNA), PPV of 83 %/80 %/88 %, sensitivity of 86 %/76 %/80 %, and specificity of 96 %/95 %/97 %. The disease prevalence was 20 %.
Conclusion All applied classifications can reliably exclude a SARS-CoV-2 infection even in an anonymous setting. Nevertheless, pre-test probability was high in our study setting and has a great influence on the classifications. Therefore, the applicability of the individual classifications will become apparent in the future with lower prevalence and incidence of COVID-19.
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Cranial Magnetic Resonance Imaging Findings in Hypotonic Infants with
Cobalamin Deficiency and Combined Methylmalonic Aciduria and
Homocystinuria
Authors: Dilber Beril , Eyüboğlu İlker 
Published: February 2022

AbstractVitamin B12 begins to accumulate in infants within the first six months while
mothers often remain asymptomatic and infantile vitamin B12 deficiency may not
be noticed until the onset of neurological effects. In infants with Cbl
deficiency, long-term exposure to elevated methylmalonic acid and homocysteine
(MMA-HC) may have toxic effects on the central nervous system. The aim of this
study was to evaluate cranial magnetic resonance (MRI) findings of 23 hypotonic
infants that were followed up with a diagnosis of nutritional Cbl deficiency and
combined MMA-HC. Of the 78 infants that presented with hypotonicity, 23
(29.4%) infants were detected with vitamin B12 deficiency. Elevated
MMA-HC levels were detected in all patients (100%). Cranial MRI showed
cortical atrophy in 6 (26.0%)-large sylvian fissures in 7
(30.4%)-ventricular dilatation in 5 (21.7%)-corpuscallosal
thinning in 6 (26.0%)-delayed myelination in 3 (13%), and normal
in 8 (34.7%) infants.Infants detected with corpus callosal thinning and
cortical atrophy on MRI. Vitamin B12 deficiency is a treatable condition, it
should be suspected in infants presenting with hypotonicity. Neuroradiological
findings should be considered in the diagnosis of such patients.
İnfantile nutritional vitamin B12 deficiency, which can be a source of
persistent neurological deficits during the long term, should be treated to
allow the patient to allow healthy neuro-development for infants. Maternal and
fetal vitamin B12 levels should be assessed during the third trimester of
pregnancy to prevent long-term exposure to infantile vitamin B12 deficiency.
Quantitative Analysis of DCE and DSC-MRI: From Kinetic Modeling to Deep Learning
Authors: Rotkopf Lukas T. , Zhang Kevin Sun , Tavakoli Anoshirwan Andrej , Bonekamp David , Ziener Christian Herbert , Schlemmer Heinz-Peter 
Published: February 2022

Background Perfusion MRI is a well-established imaging modality with a multitude of applications in oncological and cardiovascular imaging. Clinically used processing methods, while stable and robust, have remained largely unchanged in recent years. Despite promising results from novel methods, their relatively minimal improvement compared to established methods did not generally warrant significant changes to clinical perfusion processing.
Results and Conclusion Machine learning in general and deep learning in particular, which are currently revolutionizing computer-aided diagnosis, may carry the potential to change this situation and truly capture the potential of perfusion imaging. Recent advances in the training of recurrent neural networks make it possible to predict and classify time series data with high accuracy. Combining physics-based tissue models and deep learning, using either physics-informed neural networks or universal differential equations, simplifies the training process and increases the interpretability of the resulting models. Due to their versatility, these methods will potentially be useful in bridging the gap between microvascular architecture and perfusion parameters, akin to MR fingerprinting in structural MR imaging. Still, further research is urgently needed before these methods may be used in clinical practice.
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Hydrogen-Bonded Xanthones as Potential UV Absorbers: The Synthesis of Xanthones from Bio-Renewable Cardanol Utilizing a Ceric Ammonium Sulfate (CAS)-Mediated Oxidation Reaction
Authors: de Koning Charles B. , Jagot Fatema , Minnie Izak , Rahman Aliyaah , Ntsimango Songeziwe , Ngwira Kennedy J. 
Published: February 2022

AbstractThe synthesis of hydrogen-bonded xanthones by using biorenewable hydrogenated cardanol (3-pentadecylphenol) is described. Hydrogenated cardanol was initially converted into various hydroxybenzophenones. These benzophenones were converted into xanthones by utilizing an oxidative ceric ammonium sulfate-mediated reaction. A subsequent ruthenium-mediated late-stage oxidation of the xanthones provided hydrogen-bonded xanthones, which displayed good UVA and UVB absorbing properties.
Biaryl Coupling of Aryldiazonium Salts and Arylboronic Acids Catalysed by Gold
Authors: Medina-Mercado Ignacio , Porcel Susana 
Published: February 2022

AbstractA gold-catalysed coupling of aryldiazonium salts with arylboronic acids is described. The reactions proceed in satisfactory yields under irradiation with blue LEDs in the presence of KF and a catalytic amount of ascorbic acid. Notably, 4-nitrobenzendiazonium tetrafluoro­borate is sufficiently reactive to undergo the coupling with a variety of arylboronic acids in the absence of aryl radical initiators. The coupling is applicable for electron-donating and electron-withdrawing groups present at the para, ortho, and meta positions of both substrates.
Levels and Predictors of Anxiety and Depression in Turkish Pregnant Woman During the Covid-19 Pandemic
Authors: Aba Yılda Arzu , Dulger Ozlem , Sık Bulat Aytek , Ozolcay Ozan 
Published: February 2022

Abstract
Objective In addition to being a medical phenomenon, pandemics affect the individual and society on several levels and lead to disruptions. In the pandemic process, different groups in the population, including pregnant women as a defenseless group, are subjected to psychological threat. The present study aimed to determine the levels of anxiety and depression and related factors in pregnant women during the the coronavirus disease 2019 (Covid-19) pandemic.
Methods The present cross-sectional study was conducted with 269 pregnant women through face-to-face interviews held in Istanbul, Turkey. Regarding the data collection tools, the Cronbach α reliability coefficient was of 0.90 for the Beck Anxiety Inventory, and of 0.85 for the Beck Depression Inventory.
Results Among the participating pregnant women, 30.5% had mild, 17.5% had moderate, and 5.9% had severe anxiety symptoms, whereas 35.3% had mild, 16.7% had moderate, and 2.2% had severe depression symptoms. We found that those who were concerned about their health had 5.36 times (p = 0.04) more risk of developing anxiety, and 4.82 times (p = 0.01) more risk of developing depression than those who were not concerned. Those who had a history of psychiatric disease had 3.92 times (p = 0.02) more risk of developing anxiety than those without it.
Conclusion We determined that about half of the pregnant women included in the study had some degree of anxiety and depression during the COVID-19 pandemic. The risk factors for anxiety and depression among the pregnant women were determined as smoking, concerns about health and getting infected with the coronavirus, history of psychiatric disease, and undergoing regular antenatal care.
Estimate of Dietary Total Antioxidant Capacity of Pregnant Women and Associated Factors
Authors: Carvalho Mariana Rinaldi , Crivellenti Lívia Castro , Sartorelli Daniela Saes 
Published: February 2022

Abstract
Objective To investigate the dietary total antioxidant capacity (DTAC) of pregnant women, and associated factors.
Methods Cross-sectional study conducted with 785 pregnant adult women attended in primary health care centers of Ribeirão Preto, state of São Paulo, Brazil. Two 24-hour dietary recalls were obtained, and the usual intake was estimated through the Multiple Source Method. The DTAC was estimated using the ferric reducing antioxidant power assay. The relationship between the higher DTAC estimate (≥ median of 4.3 mmol/day) and associated factors was investigated using adjusted logistic models with backward selection.
Results In total, 25% of the pregnant women were classified as overweight, and 32% as obese. The median (P25, P75) DTAC was 4.3 (3.3–5.6) mmol/day. Through adjusted logistic regression models with backward selection, a higher chance of DTAC estimates above the median among pregnant women aged ≥ 35 years old (2.01 [1.24–3.27]) was verified when compared with younger pregnant women. Women with prepregnancy overweight (0.63 [0.45–0.89]) and obesity (0.59 [0.40–0.88]) presented a lower chance of DTAC estimates above the median when compared with eutrophic pregnant women. A higher DTAC estimate was positively associated with the use of dietary supplements (1.39 [1.03–1.88]), and negatively associated with total dietary energy (0.59 [0.42–0.85]).
Conclusion The DTAC estimate over the median was associated with greater age, adequate body weight, use of dietary supplements, and lower energy intake.