bluuebunny/crossref_metadata_2025 huggingface dataset:
Ecology of the digital world of Wikipedia
Authors: Ogushi Fumiko , Kertész János , Kaski Kimmo , Shimada Takashi
Published: September 2021

Wikipedia, a paradigmatic example of online knowledge space is organized in a collaborative, bottom-up way with voluntary contributions, yet it maintains a level of reliability comparable to that of traditional encyclopedias. The lack of selected professional writers and editors makes the judgement about quality and trustworthiness of the articles a real challenge. Here we show that a self-consistent metrics for the network defined by the edit records captures well the character of editors’ activity and the articles’ level of complexity. Using our metrics, one can better identify the human-labeled high-quality articles, e.g., “featured” ones, and differentiate them from the popular and controversial articles. Furthermore, the dynamics of the editor-article system is also well captured by the metrics, revealing the evolutionary pathways of articles and diverse roles of editors. We demonstrate that the collective effort of the editors indeed drives to the direction of article improvement.
Adipokinetic hormone (AKH), energy budget and their effect on feeding and gustatory processes of foraging honey bees
Authors: de Brito Sanchez Gabriela , Expósito Muñoz Anna , Chen Li , Huang Weifone , Su Songkun , Giurfa Martin
Published: September 2021

The adipokinetic hormone (AKH) of insects is considered an equivalent of the mammalian hormone glucagon as it induces fast mobilization of carbohydrates and lipids from the fat body upon starvation. Yet, in foraging honey bees, which lack fat body storage for carbohydrates, it was suggested that AKH may have lost its original function. Here we manipulated the energy budget of bee foragers to determine the effect of AKH on appetitive responses. As AKH participates in a cascade leading to acceptance of unpalatable substances in starved Drosophila, we also assessed its effect on foragers presented with sucrose solution spiked with salicin. Starved and partially-fed bees were topically exposed with different doses of AKH to determine if this hormone modifies food ingestion and sucrose responsiveness. We found a significant effect of the energy budget (i.e. starved vs. partially-fed) on the decision to ingest or respond to both pure sucrose solution and sucrose solution spiked with salicin, but no effect of AKH per se. These results are consistent with a loss of function of AKH in honey bee foragers, in accordance with a social life that implies storing energy resources in the hive, in amounts that exceed individual needs.
Concomitant and decoupled effects of cigarette smoke and SCAL1 upregulation on oncogenic phenotypes and ROS detoxification in lung adenocarcinoma cells
Authors: Cruz Carmela Rieline V. , Ferrer Jose Lorenzo M. , Garcia Reynaldo L.
Published: September 2021

Lung cancer is the leading cause of cancer deaths worldwide, with smoking as its primary predisposing factor. Although carcinogens in cigarettes are known to cause oncogenic DNA alterations, analyses of patient cohorts revealed heterogeneous genetic aberrations with no clear driver mutations. The contribution of noncoding RNAs (ncRNAs) in the pathogenesis of lung cancer has since been demonstrated. Their dysregulation has been linked to cancer initiation and progression. A novel long noncoding RNA (lncRNA) called smoke and cancer-associated lncRNA 1 (SCAL1) was recently found upregulated in smoke-exposed adenocarcinomic alveolar epithelial cells. The present study characterized the phenotypic consequences of SCAL1 overexpression and knockdown using A549 cells as model system, with or without prior exposure to cigarette smoke extract (CSE). Increase in SCAL1 levels either by CSE treatment or SCAL1 overexpression led to increased cell migration, extensive cytoskeletal remodeling, and resistance to apoptosis. Further, SCAL1 levels were negatively correlated with intracellular levels of reactive oxygen species (ROS). In contrast, SCAL1 knockdown showed converse results for these assays. These results confirm the oncogenic function of SCAL1 and its role as a CSE-activated lncRNA that mediates ROS detoxification in A549 cells, thereby allowing them to develop resistance to and survive smoke-induced toxicity.
Confidence guides priority between forthcoming tasks
Authors: Aguilar-Lleyda David , de Gardelle Vincent
Published: September 2021

Humans can estimate confidence in their decisions, and there is increasing interest on how this feeling of confidence regulates future behavior. Here, we investigate whether confidence in a perceptual task affects prioritizing future trials of that task, independently of task performance. To do so, we experimentally dissociated confidence from performance. Participants judged whether an array of differently colored circles was closer to blue or red, and we manipulated the mean and variability of the circles’ colors across the array. We first familiarized participants with a low mean low variability condition and a high mean high variability condition, which were matched in performance despite participants being more confident in the former. Then we made participants decide in which order to complete forthcoming trials for both conditions. Crucially, prioritizing one condition was associated with being more confident in that condition compared to the other. This relationship was observed both across participants, by correlating inter-individual heterogeneity in prioritization and in confidence, and within participants, by assessing how changes in confidence with accuracy, condition and response times could predict prioritization choices. Our results suggest that confidence, above and beyond performance, guides prioritization between forthcoming tasks, strengthening the evidence for its role in regulating behavior.
Eye movement as a biomarker of impaired organizational strategies during visual memory encoding in obsessive–compulsive disorder
Authors: Kim Minah , Shin Woncheol , Lee Tak Hyung , Kim Taekwan , Hwang Wu Jeong , Kwon Jun Soo
Published: September 2021

The symptoms of obsessive–compulsive disorder (OCD) are largely related to impaired executive functioning due to frontostriatal dysfunction. To better treat OCD, the development of biomarkers to bridge the gap between the symptomatic-cognitive phenotype and brain abnormalities is warranted. Therefore, we aimed to identify biomarkers of impaired organizational strategies during visual encoding processes in OCD patients by developing an eye tracking-based Rey–Osterrieth complex figure test (RCFT). In 104 OCD patients and 114 healthy controls (HCs), eye movements were recorded during memorization of the RCFT figure, and organizational scores were evaluated. Kullback–Leibler divergence (KLD) scores were calculated to evaluate the distance between a participant’s eye gaze distribution and a hypothetical uniform distribution within the RCFT figure. Narrower gaze distributions within the RCFT figure, which yielded higher KLD scores, indicated that the participant was more obsessed with detail and had less organizational strategy. The OCD patients showed lower organizational scores than the HCs. Although no group differences in KLD scores were noted, KLD scores were significantly associated with organization T scores in the OCD group. The current study findings suggest that eye tracking biomarkers of visual memory encoding provide a rapidly determined index of executive functioning, such as organizational strategies, in OCD patients.
Cosmology in the mimetic higher-curvature $$f(R,R_{\mu \nu }R^{\mu \nu })$$ gravity
Authors: Kaczmarek Adam Z. , Szczȩśniak Dominik
Published: September 2021

In the framework of the mimetic approach, we study the $$f(R,R_{\mu \nu }R^{\mu \nu })$$

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gravity with the Lagrange multiplier constraint and the scalar potential. We introduce field equations for the discussed theory and overview their properties. By using the general reconstruction scheme we obtain the power law cosmology model for the $$f(R,R_{\mu \nu }R^{\mu \nu })=R+d(R_{\mu \nu }R^{\mu \nu })^p$$

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case as well as the model that describes symmetric bounce. Moreover, we reconstruct model, unifying both matter dominated and accelerated phases, where ordinary matter is neglected. Using inverted reconstruction scheme we recover specific $$f(R,R_{\mu \nu }R^{\mu \nu })$$

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function which give rise to the de-Sitter evolution. Finally, by employing the perfect fluid approach, we demonstrate that this model can realize inflation consistent with the bounds coming from the BICEP2/Keck array and the Planck data. We also discuss the holographic dark energy density in terms of the presented $$f(R,R_{\mu \nu }R^{\mu \nu })$$

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theory. Thus, it is suggested that the introduced extension of the mimetic regime may describe any given cosmological model.
Combined effect of nitrogen-doped functional groups and porosity of porous carbons on electrochemical performance of supercapacitors
Authors: Ilnicka Anna , Skorupska Malgorzata , Szkoda Mariusz , Zarach Zuzanna , Kamedulski Piotr , Zielinski Wojciech , Lukaszewicz Jerzy P.
Published: September 2021

In this work, nitrogen-doped porous carbons obtained from chitosan, gelatine, and green algae were investigated in their role as supercapacitor electrodes. The effects of three factors on electrochemical performance have been studied—of the specific surface area, functional groups, and a porous structure. Varying nitrogen contents (from 5.46 to 10.08 wt.%) and specific surface areas (from 532 to 1095 m2 g−1) were obtained by modifying the carbon precursor and the carbonization temperature. Doping nitrogen into carbon at a level of 5.74–7.09 wt.% appears to be the optimum for obtaining high electrochemical capacitance. The obtained carbons exhibited high capacitance (231 F g−1 at 0.1 A g−1) and cycle durability in a 0.2 mol L−1 K2SO4 electrolyte. Capacitance retention was equal to 91% at 5 A g−1 after 10,000 chronopotentiometry cycles. An analysis of electrochemical behaviour reveals the influence that nitrogen functional groups have on pseudocapacitance. While quaternary-N and pyrrolic-N nitrogen groups have an enhancing effect, due to the presence of a positive charge and thus improved electron transfer at high current loads, the most important functional group affecting energy storage performance is graphite-N/quaternary-N. The study points out that the search for the most favourable organic precursors is as important as the process of converting precursors to carbon-based electrode materials.
A scanning dynamic collimator for spot-scanning proton minibeam production
Authors: Sotiropoulos Marios , Prezado Yolanda
Published: September 2021

In proton minibeam radiation therapy, proton minibeams are typically produced by modulating a uniform field using a multislit collimator. Multislit collimators produce minibeams of fixed length and width, and a new collimator has to be manufactured each time a new minibeam array is required, limiting its flexibility. In this work, we propose a scanning dynamic collimator for the generation of proton minibeams arrays. The new collimator system proposed is able to produce any minibeam required on an on-line basis by modulating the pencil beam spots of modern proton therapy machines, rather than a uniform field. The new collimator is evaluated through Monte Carlo simulations and the produced proton minibeams are compared with that of a multislit collimator. Furthermore, a proof of concept experiment is conducted to demonstrate the feasibility of producing a minibeam array by repositioning (i.e. scanning) a collimator. It is concluded that besides the technical challenges, the new collimator design is producing equivalent minibeam arrays to the multislit collimator, whilst is flexible to produce any minibeam array desired.
Past environmental changes affected lemur population dynamics prior to human impact in Madagascar
Authors: Teixeira Helena , Montade Vincent , Salmona Jordi , Metzger Julia , Bremond Laurent , Kasper Thomas , Daut Gerhard , Rouland Sylvie , Ranarilalatiana Sandratrinirainy , Rakotondravony Romule , Chikhi Lounès , Behling Hermann , Radespiel Ute
Published: September 2021

Quaternary climatic changes have been invoked as important drivers of species diversification worldwide. However, the impact of such changes on vegetation and animal population dynamics in tropical regions remains debated. To overcome this uncertainty, we integrated high-resolution paleoenvironmental reconstructions from a sedimentary record covering the past 25,000 years with demographic inferences of a forest-dwelling primate species (Microcebus arnholdi), in northern Madagascar. Result comparisons suggest that climate changes through the African Humid Period (15.2 – 5.5 kyr) strongly affected the demographic dynamics ofM. arnholdi. We further inferred a population decline in the last millennium which was likely shaped by the combination of climatic and anthropogenic impacts. Our findings demonstrate that population fluctuations in Malagasy wildlife were substantial prior to a significant human impact. This provides a critical knowledge of climatically driven, environmental and ecological changes in the past, which is essential to better understand the dynamics and resilience of current biodiversity.
Rapid synthesis of Cu2O hollow spheres at low temperature and their catalytic performance for the decomposition of ammonium perchlorate
Authors: Lv Tao-Tao , Xing Huai-Zhong , Yang Hong-Mei , Wang Hui-Xiang , Shi Jing , Cao Jing-Pei , Lv Bao-Liang
Published: September 2021

A simple and efficient strategy for synthesizing high-performance crystalline catalyst Cu2O hollow spheres with a large specific surface area was demonstrated.
Supramolecular catalysis: the role of H-bonding interactions in substrate orientation and activation
Authors: Pachisia Sanya , Gupta Rajeev
Published: September 2021

This perspective highlights the importance of hydrogen bonds in supramolecular complexes for the recognition and binding of a substrate that subsequently influence and/or control the catalytic outcome.
The modulation effect of carboxylic acid ligands on the electron transfer photochromism of NDI-derived coordination polymers
Authors: Li Gao-Peng , Zhu Huihui , Hao Pengfei , Shen Junju , Fu Yunlong
Published: September 2021

The carboxylic acid ligands can effectively modulate the interfacial contacts of electron donors/acceptors and the photochromic properties of naphthalene diimide-derived coordination polymers.
Formation of a hydride containing amido-zincate using pinacolborane
Authors: Uzelac Marina , Yuan Kang , Nichol Gary S. , Ingleson Michael J.
Published: September 2021

Careful tuning of the nature of the amide ligand in amido-zincates allows for selective Zn–C over Zn–N exchange with HBPin affording a hydride containing amido-zincate. The mixed hydrido-phenyl zincate preferentially transfers hydride over phenyl.
NIR emission of lanthanides for ultrasensitive luminescence manometry—Er3+-activated optical sensor of high pressure
Authors: Runowski Marcin , Zheng Teng , Woźny Przemysław , Du Peng
Published: September 2021

Ultrasensitive luminescent manometer operating in the NIR spectral range.
Filled trivacant icosahedra as building fragments in 17-atom endohedral germanides [TM2@Ge17]n−(TM= Co, Ni)
Authors: Wallach Christoph , Selic Yasmin , Witzel Benedikt J. L. , Klein Wilhelm , Fässler Thomas F.
Published: September 2021

Endohedral germanides [TM2@Ge17]n−(TM= Co, Ni) comprising structure motifs of twelve-atom icosahedral clusters mark intermediates for cluster growth mechanisms.
Prospects of an engineered tumor-targeted nanotheranostic platform based on NIR-responsive upconversion nanoparticles
Authors: Sabu Arjun , Lin Jui-Yen , Doong Ruey-An , Huang Yu-Fen , Chiu Hsin-Cheng
Published: September 2021

Engineered tumor-targeted UCNPs as NIR-responsive theranostic agents for imaging and therapy. Pictorial representation includes different topics discussed in this review.
Supercooling suppression of phase change liquid metal–polydimethylsiloxane soft composites
Authors: Ma Jiexian , Zhang Pu
Published: September 2021

Supercooling is suppressed in liquid metal polydimethylsiloxane composites for the first time.
Direct intercalation of MoS2 and WS2 thin films by vacuum filtration
Authors: Kuo Ding-Yuan , Cossairt Brandi M.
Published: September 2021

We report a versatile method to prepare intercalated transition metal dichalcogenides in a thin-film morphology. Metallocenes, alkylamines, and electron-proton transfer mediators are intercalated into MoS2 and WS2 using vacuum filtration.
Targeting tubulin polymerization and DNA binding of 4-thiazolidinone–umbelliferone hybrids: synthesis and cytotoxicity evaluation
Authors: Sigalapalli Dilep Kumar , Kiranmai Gaddam , Tokala Ramya , Tripura Chaturvedula , Ambatwar Ramesh , Nunewar Saiprasad N. , Kadagathur Manasa , Shankaraiah Nagula , Nagesh Narayana , Nagendra Babu Bathini , Tangellamudi Neelima D.
Published: September 2021

The discovery of a series of combretastatin A-4 inspired novel molecular hybrids of 4-thiazolidinone–umbelliferone as prominent cytotoxic agents was reported.
Highly conductive triple-layered hollow MnO2@SnO2@NHCS nanospheres with excellent lithium storage capacity for high performance lithium-ion batteries
Authors: Mei Yameng , Zhao Jin'an , Dang Liyun , Hu Jiyong , Guo Yan , Zhang Shuaiguo
Published: September 2021

Multilayered hollow MnO2@SnO2@NHCS nanospheres incorporate the merits of highly conductive N-doping and the synergistic effect of metal oxides.
Cation-chloride cotransport mediated by an ion pair transporter
Authors: Zhu Jun , Wang Xu-Dong , Luo Jian , Ao Yu-Fei , Wang Qi-Qiang , Wang De-Xian
Published: September 2021

Chloride transport across a membrane mediated by an ion pair receptor through K+/Cl− or Na+/Cl− cotransport with a selectivity towards the K+/Cl− symport was realized.
A top-down approach making cellulose carbonaceous aerogel/MnO2 ultrathick bulk electrodes with high mass loading for supercapacitors
Authors: Zhang Weiye , Li Yanchen , Wang Beibei , Sun Jingmeng , Lin Lin , Liu Yi , Guo Hongwu
Published: September 2021

A cellulose carbonaceous aerogel/MnO2 ultrathick electrode with a unique low curvature, porous carbon thin-walled tube array structure was obtained from natural wood using a simple top-down approach.
Emulsion templated advanced functional materials from emerging nano building blocks
Authors: Yao Chenfei , Shi Ge , Hu Yijie , Zhuo Hao , Chen Zehong , Peng Xinwen , Zhong Linxin , Liu Chuanfu
Published: September 2021

The latest progress in emulsion templating of emerging nano building blocks and materials including monoliths, films and microcapsules is summarized. Typical applications of these functional materials are critically discussed in various fields.
Self-assembly of a g-C3N4-based 3D aerogel induced by N-modified carbon dots for enhanced photocatalytic hydrogen production
Authors: Pu Xiao-Long , Yang Xue-Chun , Liang Shan-Shan , Wang Wenzhong , Zhao Jing-Tai , Zhang Zhi-Jun
Published: September 2021

A g-C3N4-based 3D aerogel with a high H2 production efficiency was prepared through an electrostatic self-assembly effect induced by N-modified carbon dots.
Gas and gas-generating nanoplatforms in cancer therapy
Authors: Jing Yuan-Zhe , Li Shu-Jin , Sun Zhi-Jun
Published: September 2021

Gas-generating nanoplatforms have promising therapeutic potential for cancer treatment.
Dual-phase zinc selenide in situ encapsulated into size-reduced ZIF-8 derived selenium and nitrogen co-doped porous carbon for efficient triiodide reduction reaction
Authors: Yuan Shuangxi , Yun Sining , Zhang Yongwei , Dang Jiaoe , Sun Menglong , Dang Changwei , Deng Yingying
Published: September 2021

A ZIF-derived Se/N-doped carbon-supported dual-phase ZnSe hybrid as a robust CE catalyst for DSSCs provides a high PCE of 8.48%.
Magnetocaloric actuation of soft polymer robots
Authors: Huang Xiaowen , Wei Jiang , Wei Hai , Zhang Lidong
Published: September 2021

We report a polymer bilayer actuator that is capable of transducing magnetic effects into heat energy in an electromagnetic field and in this way shows various controllable motions.
Bimodal Fitting and Bilateral Cochlear Implants in Children With Significant Residual Hearing: The Impact of Asymmetry in Spatial Release of Masking on Localization
Authors: Sparreboom Marloes , Ausili Sebastián , Agterberg Martijn J. H. , Mylanus Emmanuel A. M.
Published: September 2021

Purpose

This study aimed to gain more insight into the primary auditory abilities of children with significant residual hearing in order to improve decision making when choosing between bimodal fitting or sequential bilateral cochlear implantation.

Method

Sound localization abilities, spatial release of masking, and fundamental frequency perception were tested. Nine children with bimodal fitting and seven children with sequential bilateral cochlear implants were included in the study. As a reference, 15 children with normal hearing and two children with simultaneous bilateral cochlear implants were included.

Results

On all outcome measures, the implanted children performed worse than the normal hearing children. For high-frequency localization, children with sequential bilateral cochlear implants performed significantly better than children with bimodal fitting. Compared to children with normal hearing, the left–right asymmetry in spatial release of masking was significant. When the implant was hindered by noise, bimodally fitted children obtained significantly lower spatial release of masking compared to when the hearing aid was hindered by noise. Overall, the larger the left–right asymmetry in spatial release of masking, the poorer the localization skills. No significant differences were found in fundamental frequency perception between the implant groups.

Conclusions

The data hint to an advantage of bilateral implantation over bimodal fitting. The extent of asymmetry in spatial release of masking is a promising tool for decision making when choosing whether to continue with the hearing aid or to provide a second cochlear implant in children with significant residual hearing.
A stellar census in globular clusters with MUSE
Authors: Latour M. , Calamida A. , Husser T.-O. , Kamann S. , Dreizler S. , Brinchmann J.
Published: September 2021

Context. ω Cen is a rare example of a globular cluster where the iron abundance of the stars spans more than one order of magnitude. Many spectroscopic investigations of its red-giant and sub-giant branches have revealed multiple peaks in the iron abundance distribution. The metallicity distribution of main sequence (MS) stars is not well characterized yet due to the faintness of the stars and lack of data. So far, almost all studies of MS stars have been based on photometric measurements.

Aims. Our goal is to investigate the metallicity distribution of a statistically significant sample of MS stars in ω Cen. In particular, we aim to revisit the metallicity difference between the red and blue MS of the cluster.

Methods. We used MUSE spectra obtained for the central region of ω Cen to derive metallicities for ≈4200 MS stars.

Results. We find that blue MS stars are, on average, ≈0.1 dex more metal-rich than their red counterparts. On the basis of this new estimate, we find that the two sequences can be fit on the Hubble Space Telescope color-magnitude diagram with two isochrones having the same global metallicity and age, but a higher helium abundance for the blue MS, that is ΔY ≲ 0.1. Furthermore, we determined the average metallicity of the five main populations along ω Cen MS and these estimates are consistent with expectations from previous photometric studies.
Exploring the Effect of Long Naps on Handball Performance and Heart Rate Variability
Authors: Nishida Masaki , Yamamoto Kei , Murata Yusuke , Ichinose Atsushi , Shioda Kohei
Published: September 2021

This study explored the effect of long naps on handball-related performance and assessed the role of the cardiac autonomic nervous system in this process. Eleven male collegiate handball players performed a repeated sequential trial consisting of a 20-m consecutive turnaround run, 10-m run with a load, and shooting the ball into a target. Participants were allocated randomly and sequentially to have a short (20 minutes) nap, long (60 minutes) nap, or no nap. The Pittsburgh Sleep Quality Index was used to assess regular sleep quality. Subjective sleepiness before and after napping was measured using the Karolinska Sleepiness Scale. Heart rate variability was recorded to assess cardiac autonomic nervous function during napping. The Pittsburgh Sleep Quality Index score was correlated with shot accuracy only after long naps (ρ=0.636, r=0.048). A negative correlation was observed between the root mean square of successive differences and average load run time (ρ=−0.929, p<0.001). Long napping was associated with a significant benefit on performance in athletes with poor sleep quality, implying a role of the autonomic nervous system in this regard. Our findings indicate the effect of sleep quality on the endurance and resistance of handball players.
Substituição do calcar cimentado versus hemiartroplastia de haste longa cimentada em fraturas intertrocantéricas instáveis em octogenários
Authors: Khatri Kavin , Banga Ravinder Kumar , Malhotra Neeraj , Bansal Deepak
Published: September 2021

Objetivo O objetivo do presente estudo foi comparar os resultados funcionais após a substituição do Calcar cimentado em comparação com a hemiartroplastia cimentada de haste longa em pacientes com mais de 80 anos com fratura intertrocantérica instável.

Métodos O presente estudo prospectivo e randomizado incluiu 140 pacientes com fratura de fêmur intertrocantérica, conforme classificação AO/OTA tipo 31-A2, A3, randomizados em 2 grupos de tratamento e acompanhados por um período mínimo de 2 anos. Sessenta e sete pacientes do grupo A foram tratados com uma prótese de substituição do calcar cimentada e 65 pacientes do grupo B foram tratados com uma prótese femoral de haste longa cimentada. Os desfechos primários foram as funções do quadril em 2 anos. Os eventos secundários foram as complicações encontradas, a mortalidade, o tempo cirúrgico, segunda cirurgia, perda de sangue e as atividades do cotidiano.

Resultados Não houve grandes diferenças entre os grupos em termos de função do quadril, qualidade de vida (relacionada à saúde), segunda cirurgia, mortalidade e perda de sangue. No entanto, a função da articulação do quadril e as atividades da vida diária se deterioraram em ambos os grupos em comparação com os níveis pré-fratura.

Conclusão Nos octogenários com fratura intertrocantérica instável, a prótese de substituição do calcar cimentada apresentou resultados clínicos semelhantes em comparação com a hemiartroplastia de haste longa cimentada. A hemiartroplastia com qualquer um dos implantes é uma boa opção nesse subgrupo de pacientes. Nível de evidência: I
Dr. Gerald Gaß zur Ära Spahn: „Bei der Digitalisierung hat Spahn Fortschritte erzielt“
Authors: Orth Anne
Published: September 2021

Jens Spahn hat in den vier Jahren als Bundesgesundheitsminister gemeinsam mit seinem Team Gesetz-entwürfe fast wie am Fließband produziert und sich auch beim Management der Corona-Pandemie hervorgetan. Wie ist Spahns Engagement aus Sicht der Krankenhäuser zu bewerten? Was lief gut, was weniger gut? Was hat der Minister versäumt, und was sollte in der nächsten Legislaturperiode auf der Agenda stehen? Dazu äußert sich Dr. Gerald Gaß, Vorstandsvorsitzender der Deutschen Krankenhausgesellschaft (DKG), im Gespräch mit kma.
Ärztlich assistierter Suizid: Regeln für den Tod
Authors: Hohnstein Aileen
Published: September 2021

Mit dem Beschluss zur Änderung der Musterberufsordnung auf dem diesjährigen Deutschen Ärztetag ist berufsrechtlich klar, dass Ärztinnen und Ärzte Suizidwillige bei ihrem Vorhaben unterstützen dürfen. Gesetzliche Rahmenbedingungen für Suizidbeihilfe fehlen noch immer, werden aber wohl nach der Bundestagswahl in den Fokus rücken.
Structure and magnetic properties of ferrimagnetic [Gd/Fe]n multilayer and GdxFe100−x thin films
Authors: Hintermayr Julian , Ullrich Aladin , Albrecht Manfred
Published: September 2021

The structural and magnetic properties of two series of [Gd(2, 4 nm)/Fe(t)]n multilayer films with varying Fe thickness were investigated and compared to those of amorphous ferrimagnetic GdFe alloys of the same corresponding composition. Transmission electron microscopy studies confirmed the high interface quality of both multilayer series. Furthermore, the microstructure was analyzed, revealing polycrystallinity in both Gd and Fe layers with strong (101̄0)-oriented textured growth of Gd particularly for the multilayer series with 2 nm Gd. Magnetic measurements confirm an out-of-plane magnetic easy axis in the alloy samples and an in-plane magnetic easy axis in all multilayer samples. Twisted spin states in samples with a low remanent magnetization were identified. Magnetic compensation points of both multilayer series are compared to those of the alloy samples. It was found that the dependence of the magnetic compensation point on effective Gd concentration in the series with 2 nm Gd closely resembles the strong dependence observed in the alloy counterparts. In contrast, a weaker dependence is revealed for the multilayer series with 4 nm Gd, which makes this system more robust against variations in composition required for applications.
Transport properties of the binary gas mixtures containing CO2, N2, SF6, and CF4 at low density
Authors: Jiang Tao , Meng Xiangzhao , Jin Lijun
Published: September 2021

The transport properties at low density are investigated in the framework of the kinetic theory of gases for five binary mixtures composed of CO2, N2, SF6, and CF4, which are of great interest to the electric power industry and are not available in the literature. The Lennard-Jones (12–6) potentials recommended in the literature are used to model the interactions between like molecules, and the Lorentz–Berthelot combining rules are employed to further describe the unlike interactions. The viscosity, binary diffusion coefficient, and thermal diffusion factor are computed for CO2–SF6, CO2–CF4, N2–SF6, N2–CF4, and SF6–CF4. The experimental data are available for the viscosity and diffusion coefficient of the studied systems over a much limited temperature range, and reasonable agreement is found between the experimental data and our calculated values. The new transport property values of the five binary mixtures are tabulated in the supplementary material, covering a very wide temperature range from 300 to 30 000 K.
Thermal performance of copper vapor chamber with double-sided uniform radial micro-grooved wicks by laser fabrication
Authors: Wang Yongchao , Wei Xin , Li Yuanke , Zhang Guohao , Hu Zhengfa , Zhang Liang , Wang Lei
Published: September 2021

In order to ensure the reliability of high heat-flux electronic devices, vapor chambers with double-sided uniform radial micro-grooved wicks (DURM) are developed. The driving force model of the working liquid inside the DURM vapor chamber is established. To enhance the driving force of the working liquid, the condensation micro-grooves and evaporation micro-grooves of the DURM vapor chamber are fabricated using an ultraviolet laser and an infrared laser, respectively. In addition, the startup characteristics and temperature uniformity of the DURM vapor chamber and the effect of the depth–width ratio and radiation angle of the micro-grooves and the filling ratio of the DURM vapor chamber on its thermal performance are also investigated. The results indicate that the DURM vapor chamber could maintain good temperature uniformity. Both the evaporation micro-grooved and condensation micro-grooved wicks facilitate the enhancement of the thermal performance of the vapor chamber. The double-sided micro-grooved wick with a larger depth–width ratio and a smaller radiation angle improves the thermal performance of the DURM vapor chamber. However, when the radiation angle is lower than 4°, further reducing the radiation angle has little effect on improving the thermal performance. In addition, an appropriate filling ratio helps reduce the thermal resistance of the vapor chamber under a certain heat load.
A novel dual-band nested transit time oscillator
Authors: Gao Xingfu , Song Lili , He Juntao , Ling Junpu , Zhang Peng , Dang Fangchao , Wang Lei
Published: September 2021

A novel dual-band nested transit time oscillator (TTO) is proposed in this paper, which consists of an outer X-band coaxial TTO and an inner Ka-band coaxial TTO. It is capable of generating dual-band microwaves simultaneously with three distinctive features. First, the emission processes of inner and outer annular electron beams are independent. Second, the inner and outer high frequency structures are spatially isolated. Third, the inner and outer annular electron beams share the guiding magnetic field. Particle-in-cell simulation is performed where a voltage of 450 kV and a guiding magnetic field of 0.6 T are used. Simulation results demonstrate that microwave output with a frequency of 8.4 GHz and a power of 1.72 GW is obtained for the X-band, corresponding to a conversion efficiency of 42% and a microwave saturation time of 30 ns. Meanwhile, microwave output with a frequency of 31.3 GHz and a power of 1.18 GW is achieved for the Ka-band, corresponding to a conversion efficiency of 40% and a microwave saturation time of 15 ns.
On minimal energy solutions to certain classes of integral equations related to soliton gases for integrable systems*
Authors: Kuijlaars Arno , Tovbis Alexander
Published: September 2021

We prove existence, uniqueness and non-negativity of solutions of certain integral equations describing the density of states u(z) in the spectral theory of soliton gases for the one dimensional integrable focusing nonlinear Schrödinger equation (fNLS) and for the Korteweg–de Vries (KdV) equation. Our proofs are based on ideas and methods of potential theory. In particular, we show that the minimising (positive) measure for a certain energy functional is absolutely continuous and its density u(z) ⩾ 0 solves the required integral equation. In a similar fashion we show that v(z), the temporal analog of u(z), is the difference of densities of two absolutely continuous measures. Together, the integral equations for u, v represent nonlinear dispersion relation for the fNLS soliton gas. We also discuss smoothness and other properties of the obtained solutions. Finally, we obtain exact solutions of the above integral equations in the case of a KdV condensate and a bound state fNLS condensate. Our results is a step towards a mathematical foundation for the spectral theory of soliton and breather gases, which appeared in work of El and Tovbis (2020 Phys. Rev. E
101 052207). It is expected that the presented ideas and methods will be useful for studying similar classes of integral equation describing, for example, breather gases for the fNLS, as well as soliton gases of various integrable systems.
Fabrication of new non-hazardous tungsten carbide epoxy resin bricks for low energy gamma shielding in nuclear medicine
Authors: Abualroos Nadin Jamal , Zainon Rafidah
Published: September 2021

Introduction. The main aim of this study was to fabricate a lead-free tungsten carbide epoxy resin brick that has similar shielding properties to lead brick for low energy gamma shielding in nuclear medicine. The attenuation properties of bricks were characterized by using gamma transmission principle in Single-Photon Emission Computed Tomography (SPECT) scanner. Materials and methods. In this study, various percentage of tungsten carbide epoxy resin were fabricated into brick with thickness of 0.5 cm, 1.0 cm, 1.5 cm and 2.0 cm. Tungsten carbide epoxy resin and lead bricks were irradiated with gamma rays from 99mTc to evaluate the radiation attenuation properties. A detector was used to evaluate the gamma shielding performance at 140 keV. The activity of the radioactive source was measured and recorded. The radiation attenuation of tungsten carbide epoxy resin bricks was compared with lead brick of same size and thickness. The gamma transmission was evaluated by using SPECT. Results. Results showed that tungsten carbide epoxy resin brick attenuates more radiation than a lead brick of the same thickness. This study also found that tungsten carbide epoxy resin brick is an effective radiation shielding material compared to lead. The best tungsten carbide and epoxy resin combination was found with a mixture of 90%:10% by weight, respectively. The study showed that both half-value layer and mean free path are higher at thicker samples for all materials at 140 keV. This study found that tungsten carbide and tungsten carbide epoxy resin bricks have small half-value layer and mean free path compared to lead brick. The values were 0.07 cm and 0.06 cm for lead and tungsten carbide, respectively. Conclusion. This study showed that attenuation coefficient measurement can be performed using gamma transmission principle in SPECT. Tungsten carbide epoxy resin shows high potential to replace lead as radiation shielding material.
Elliptic curves over totally real quartic fields not containing √5 are modular
Authors: Box Josha
Published: September 2021

We prove that every elliptic curve defined over a totally real number field of degree 4 not containing

5

\sqrt {5}

is modular. To this end, we study the quartic points on four modular curves.
Assessment of the Oxidative Potential and Oxidative Burden from Occupational Exposures to Particulate Matter
Authors: Fleck Alan da Silveira , Debia Maximilien , Ryan Patrick Eddy , Couture Caroline , Traub Alison , Evans Greg J , Suarthana Eva , Smargiassi Audrey
Published: September 2021

Oxidative potential (OP) is a toxicologically relevant metric that integrates features like mass concentration and chemical composition of particulate matter (PM). Although it has been extensively explored as a metric for the characterization of environmental particles, this is still an underexplored application in the occupational field. This study aimed to estimate the OP of particles in two occupational settings from a construction trades school. This characterization also includes the comparison between activities, sampling strategies, and size fractions. Particulate mass concentrations (PM4-Personal, PM4-Area, and PM2.5-Area) and number concentrations were measured during three weeks of welding and construction/bricklaying activities. The OP was assessed by the ascorbate assay (OPAA) using a synthetic respiratory tract lining fluid (RTLF), while the oxidative burden (OBAA) was determined by multiplying the OPAA values with PM concentrations. Median (25th–75th percentiles) of PM mass and number concentrations were 900 (672–1730) µg m–3 and 128 000 (78 000–169 000) particles cm–3 for welding, and 432 (345–530) µg m–3 and 2800 (1700–4400) particles cm–3 for construction. Welding particles, especially from the first week of activities, were also associated with higher redox activity (OPAA: 3.3 (2.3–4.6) ρmol min–1 µg–1; OBAA: 1750 (893–4560) ρmol min–1 m–3) compared to the construction site (OPAA: 1.4 (1.0–1.8) ρmol min–1 µg–1; OBAA: 486 (341–695) ρmol min–1 m–3). The OPAA was independent of the sampling strategy or size fraction. However, driven by the higher PM concentrations, the OBAA from personal samples was higher compared to area samples in the welding shop, suggesting an influence of the sampling strategy on PM concentrations and OBAA. These results demonstrate that important levels of OPAA can be found in occupational settings, especially during welding activities. Furthermore, the OBAA found in both workplaces largely exceeded the levels found in environmental studies. Therefore, measures of OP and OB could be further explored as metrics for exposure assessment to occupational PM, as well as for associations with cardiorespiratory outcomes in future occupational epidemiological studies.
Effect of diglyceryl dicaprylate on Candida albicans growth and pathogenicity
Authors: Koide Tomojiro , Tamura Muneaki
Published: September 2021

The antifungal effect of diglyceryl dicaprylate, one of the emulsifiers used as a food additive, on Candida albicans that is a pathogenic fungus that is predominant in the oral cavity was investigated. This component did not affect C. albicans growth; however, it suppressed some virulence factors in a concentration-dependent manner. Furthermore, the suppression of pathogenic factors, such as biofilm formation, adhesion, highly pathogenic dimorphism, and ability to produce proteolytic enzymes, was due to reduction in mRNA expression levels of genes involved in fungal pathogenicities. From these results, this emulsifier could potentially prevent the development of intraoral and extraoral diseases involving C. albicans and could potentially use in oral care and improvement of quality of life.
Impact of preoperative breast MRI on 10-year survival of patients included in the Swedish randomized multicentre POMB trial
Authors: Gonzalez V , Arver B , Löfgren L , Bergkvist L , Sandelin K , Eriksson S
Published: September 2021

Background

The value of preoperative breast MRI as an adjunct technique regarding its effect on re-excision rates has been a subject of discussion. No survival data regarding preoperative breast MRI are available from randomized studies.

Methods

Ten-year follow-up of the POMB randomized multicentre study was analysed, evaluating MRI and its effect on disease-free survival (DFS) and overall survival (OS). Patients with newly diagnosed breast cancer were randomized to either preoperative MRI or conventional imaging. Kaplan–Meier plots were used to analyse DFS and OS, and Cox regression to estimate hazard ratios (HRs).

Results

A total of 440 patients, aged 56 years or less, with newly diagnosed breast cancer were randomized to either preoperative MRI (220) or conventional imaging (220; control). Median follow-up for each group was 10 years. DFS rates were 85.5 and 80.0 per cent for the MRI and control groups respectively (P = 0.099). The risk of relapse or death was 46 per cent higher in the control group (HR 1.46, 95 per cent c.i. 0.93 to 2.29). OS rates after 10 years were 90.9 and 88.6 per cent in the MRI and control groups respectively (P = 0.427). The risk of death was 27 per cent higher in the control group (HR 1.27, 0.71 to 2.29). Locoregional, distant, and contralateral recurrence outcomes combined were increased in the control group (P = 0.048). A subgroup analysis of patients with breast cancer stages I–III showed that preoperative MRI improved DFS compared with conventional imaging, but this did not reach statistical significance (P = 0.057).

Conclusion

After 10 years of follow-up, preoperative breast MRI as an adjunct to conventional imaging resulted in slightly, but non-significantly, improved DFS and OS. Registration number: NCT01859936 (http://www.clinicaltrials.gov).
Infectious Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Exhaled Aerosols and Efficacy of Masks During Early Mild Infection
Authors: Adenaiye Oluwasanmi O , Lai Jianyu , Bueno de Mesquita P Jacob , Hong Filbert , Youssefi Somayeh , German Jennifer , Tai S H Sheldon , Albert Barbara , Schanz Maria , Weston Stuart , Hang Jun , Fung Christian , Chung Hye Kyung , Coleman Kristen K , Sapoval Nicolae , Treangen Todd , Berry Irina Maljkovic , Mullins Kristin , Frieman Matthew , Ma Tianzhou , Milton Donald K
Published: September 2021

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemiology implicates airborne transmission; aerosol infectiousness and impacts of masks and variants on aerosol shedding are not well understood.

Methods

We recruited coronavirus disease 2019 (COVID-19) cases to give blood, saliva, mid-turbinate and fomite (phone) swabs, and 30-minute breath samples while vocalizing into a Gesundheit-II, with and without masks at up to 2 visits 2 days apart. We quantified and sequenced viral RNA, cultured virus, and assayed serum samples for anti-spike and anti-receptor binding domain antibodies.

Results

We enrolled 49 seronegative cases (mean days post onset 3.8 ± 2.1), May 2020 through April 2021. We detected SARS-CoV-2 RNA in 36% of fine (≤5 µm), 26% of coarse (>5 µm) aerosols, and 52% of fomite samples overall and in all samples from 4 alpha variant cases. Masks reduced viral RNA by 48% (95% confidence interval [CI], 3 to 72%) in fine and by 77% (95% CI, 51 to 89%) in coarse aerosols; cloth and surgical masks were not significantly different. The alpha variant was associated with a 43-fold (95% CI, 6.6- to 280-fold) increase in fine aerosol viral RNA, compared with earlier viruses, that remained a significant 18-fold (95% CI, 3.4- to 92-fold) increase adjusting for viral RNA in saliva, swabs, and other potential confounders. Two fine aerosol samples, collected while participants wore masks, were culture-positive.

Conclusions

SARS-CoV-2 is evolving toward more efficient aerosol generation and loose-fitting masks provide significant but only modest source control. Therefore, until vaccination rates are very high, continued layered controls and tight-fitting masks and respirators will be necessary.
A Patient-Prioritized Agenda for Information Needs During the COVID-19 Pandemic: A Qualitative Study of Patients With Inflammatory Bowel Disease
Authors: Long Millie D , Grewe Mary E , Cerciello Emily , Weisbein Laura , Catabay Kyra , Kappelman Michael D
Published: September 2021

Background

Patients with inflammatory bowel disease (IBD) may be at risk for complications due to the COVID-19 pandemic. We performed a qualitative study to better understand IBD patient experiences and concerns when navigating the COVID-19 pandemic, with the goal of prioritizing patients’ information needs.

Methods

We conducted a series of semistructured virtual focus groups at 6 months, then member checking focus groups 1 year into the COVID-19 pandemic. We included questions on patients’ experiences navigating the pandemic with IBD, differences in their experience as compared to peers, their concerns and fears, as well as preferred information sources. Transcribed focus groups were coded and content analyzed to summarize key areas of interest and identify themes. We focused on 4 areas in our content analysis process: fears, challenges, information preferences, and research questions.

Results

A total of 26 IBD patient participants were included in the initial focus groups. Findings highlighted the many challenges faced by patients during the COVID-19 pandemic, ranging from access (bathrooms, medications, healthcare) to significant fears and concerns surrounding medications used for IBD worsening risks of COVID-19. Research questions of importance to patients centered on understanding risks for COVID-19 complications, particularly pertaining to medication utilization, with a shift over time toward understanding COVID-19 vaccination. In our member checking focus groups (n = 8 participants), themes were reiterated, with a central focus of research questions pertaining to COVID-19 vaccination.

Conclusions

Information needs for patients during the COVID-19 pandemic centered upon understanding disease-specific risks. Identified challenges and fears will inform future research agendas and communication with patients.