bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low ventilatory responsiveness to transient hypoxia or breath-holding predicts fast marathon performance in healthy middle-aged and older men
Authors: Paleczny Bartłomiej , Seredyński Rafał , Wyciszkiewicz Małgorzata , Nowicka-Czudak Adrianna , Łopusiewicz Wojciech , Adamiec Dorota , Wiecha Szczepan , Mroczek Dariusz , Chmura Paweł , Konefał Marek , Maćkała Krzysztof , Chromik Krystyna , Pawlik Damian , Andrzejewski Marcin , Chmura Jan , Ponikowski Piotr , Ponikowska Beata 
Published: May 2021

AbstractThe aim of this study was to test the utility of haemodynamic and autonomic variables (e.g. peripheral chemoreflex sensitivity [PCheS], blood pressure variability [BPV]) for the prediction of individual performance (marathon time and VO2max) in older men. The post-competition vasodilation and sympathetic vasomotor tone predict the marathon performance in younger men, but their prognostic relevance in older men remains unknown. The peripheral chemoreflex restrains exercise-induced vasodilation via sympathetically-mediated mechanism, what makes it a plausible candidate for the individual performance marker. 23 men aged ≥ 50 year competing in the Wroclaw Marathon underwent an evaluation of: resting haemodynamic parameters, PCheS with two methods: transient hypoxia and breath-holding test (BHT), cardiac barosensitivity, heart rate variability (HRV) and BPV, plasma renin and aldosterone, VO2max in a cardiopulmonary exercise test (CPET). All tests were conducted twice: before and after the race, except for transient hypoxia and CPET which were performed once, before the race. Fast marathon performance and high VO2max were correlated with: low ventilatory responsiveness to hypoxia (r =  − 0.53, r = 0.67, respectively) and pre-race BHT (r =  − 0.47, r = 0.51, respectively), (1) greater SD of beat-to-beat SBP (all p < 0.05). Fast performance was related with an enhanced pre-race vascular response to BHT (r =  − 0.59, p = 0.005). The variables found by other studies to predict the marathon performance in younger men: post-competition vasodilation, sympathetic vasomotor tone (LF-BPV) and HRV were not associated with the individual performance in our population. The results suggest that PCheS (ventilatory response) predicts individual performance (marathon time and VO2max) in men aged ≥ 50 yeat. Although cause-effect relationship including the role of peripheral chemoreceptors in restraining the post-competition vasodilation via the sympathetic vasoconstrictor outflow may be hypothesized to underline these findings, the lack of correlation between individual performance and both, the post-competition vasodilation and the sympathetic vasomotor tone argues against such explanation. Vascular responsiveness to breath-holding appears to be of certain value for predicting individual performance in this population, however.
Compressive spectral image fusion via a single aperture high throughput imaging system
Authors: Rueda-Chacon Hoover , Rojas Fernando , Arguello Henry 
Published: May 2021

AbstractSpectral image fusion techniques combine the detailed spatial information of a multispectral (MS) image and the rich spectral information of a hyperspectral (HS) image into a high-spatial and high-spectral resolution image. Due to the data deluge entailed by such images, new imaging modalities have exploited their intrinsic correlations in such a way that, a computational algorithm can fuse them from few multiplexed linear projections. The latter has been coined compressive spectral image fusion. State-of-the-art research work have focused mainly on the algorithmic part, simulating instrumentation characteristics and assuming independently registered sensors to conduct compressed MS and HS imaging. In this manuscript, we report on the construction of a unified computational imaging framework that includes a proof-of-concept optical testbed to simultaneously acquire MS and HS compressed projections, and an alternating direction method of multipliers algorithm to reconstruct high-spatial and high-spectral resolution images from the fused compressed measurements. The testbed employs a digital micro-mirror device (DMD) to encode and split the input light towards two compressive imaging arms, which collect MS and HS measurements, respectively. This strategy entails full light throughput sensing since no light is thrown away by the coding process. Further, different resolutions can be dynamically tested by binning the DMD and sensors pixels. Real spectral responses and optical characteristics of the employed equipment are obtained through a per-pixel point spread function calibration approach to enable accurate compressed image fusion performance. The proposed framework is demonstrated through real experiments within the visible spectral range using as few as 5% of the data.
Regulation of mammalian 3D genome organization and histone H3K9 dimethylation by H3K9 methyltransferases
Authors: Fukuda Kei , Shimura Chikako , Miura Hisashi , Tanigawa Akie , Suzuki Takehiro , Dohmae Naoshi , Hiratani Ichiro , Shinkai Yoichi 
Published: May 2021

AbstractHistone H3 lysine 9 dimethylation (H3K9me2) is a highly conserved silencing epigenetic mark. Chromatin marked with H3K9me2 forms large domains in mammalian cells and overlaps well with lamina-associated domains and the B compartment defined by Hi-C. However, the role of H3K9me2 in 3-dimensional (3D) genome organization remains unclear. Here, we investigated genome-wide H3K9me2 distribution, transcriptome, and 3D genome organization in mouse embryonic stem cells following the inhibition or depletion of H3K9 methyltransferases (MTases): G9a, GLP, SETDB1, SUV39H1, and SUV39H2. We show that H3K9me2 is regulated by all five MTases; however, H3K9me2 and transcription in the A and B compartments are regulated by different MTases. H3K9me2 in the A compartments is primarily regulated by G9a/GLP and SETDB1, while H3K9me2 in the B compartments is regulated by all five MTases. Furthermore, decreased H3K9me2 correlates with changes to more active compartmental state that accompanied transcriptional activation. Thus, H3K9me2 contributes to inactive compartment setting.
Reduced resilience of terrestrial ecosystems locally is not reflected on a global scale
Authors: Feng Yuhao , Su Haojie , Tang Zhiyao , Wang Shaopeng , Zhao Xia , Zhang Heng , Ji Chengjun , Zhu Jiangling , Xie Ping , Fang Jingyun 
Published: May 2021

AbstractGlobal climate change likely alters the structure and function of vegetation and the stability of terrestrial ecosystems. It is therefore important to assess the factors controlling ecosystem resilience from local to global scales. Here we assess terrestrial vegetation resilience over the past 35 years using early warning indicators calculated from normalized difference vegetation index data. On a local scale we find that climate change reduced the resilience of ecosystems in 64.5% of the global terrestrial vegetated area. Temperature had a greater influence on vegetation resilience than precipitation, while climate mean state had a greater influence than climate variability. However, there is no evidence for decreased ecological resilience on larger scales. Instead, climate warming increased spatial asynchrony of vegetation which buffered the global-scale impacts on resilience. We suggest that the response of terrestrial ecosystem resilience to global climate change is scale-dependent and influenced by spatial asynchrony on the global scale.
Unklare Lymphadenopathie mit Panzytopenie bei einer Patientin mit rezidivierenden Hypoglykämien
Authors: Lindmeyer Anna M. , Nauck Michael A. , Meier Juris J. 
Published: May 2021

ZusammenfassungEine Patientin wurde aufgrund rezidivierender postprandialer Hypoglykämien nach Roux-en-Y-Magenbypass mit Diazoxid behandelt, nachdem eine Ernährungsumstellung keine Symptomlinderung erzielt hatte. Nach Eindosierung von Diazoxid mit guter Akutverträglichkeit wurde die Patientin entlassen. Eine Woche nach Therapieeinleitung kam es zu einer Lymphadenopathie und Panzytopenie. Es fanden sich keine Hinweise auf das Vorliegen eines Infekts. Nach Absetzen von Diazoxid sistierten die Beschwerden. Unser Fallbericht weist auf seltene unerwünschte hämatologische Arzneimittelwirkungen unter Diazoxid hin.
Using a Simple Prescription Gap to Determine Warfarin Discontinuation Can Lead to Substantial Misclassification
Authors: Lin Kueiyu Joshua , Schneeweiss Sebastian , Pawar Ajinkya , Singer Daniel E. , Liu Jun , Gagne Joshua J. 
Published: May 2021

AbstractBackground Warfarin remains widely used and a key comparator in studies of other direct oral anticoagulants. As longer-than-needed warfarin prescriptions are often provided to allow for dosing adjustments according to international normalized ratios (INRs), the common practice of using a short allowable gap between dispensings to define warfarin discontinuation may lead to substantial misclassification of warfarin exposure. We aimed to quantify such misclassification and determine the optimal algorithm to define warfarin discontinuation.Methods We linked Medicare claims data from 2007 to 2014 with a multicenter electronic health records system. The study cohort comprised patients ≥65 years with atrial fibrillation and venous thromboembolism initiating warfarin. We compared results when defining warfarin discontinuation by (1) different gaps (3, 7, 14, 30, and 60 days) between dispensings and (2) having a gap ≤60 days or bridging larger gaps if there was INR ordering at least every 42 days (60_INR). Discontinuation was considered misclassified if there was an INR ≥2 within 7 days after the discontinuation date.Results Among 3,229 patients, a shorter gap resulted in a shorter mean follow-up time (82, 95, 117, 159, 196, and 259 days for gaps of 3, 7, 14, 30, 60, and 60_INR, respectively; p < 0.001). Incorporating INR (60_INR) can reduce misclassification of warfarin discontinuation from 68 to 4% (p < 0.001). The on-treatment risk estimation of clinical endpoints varied significantly by discontinuation definitions.Conclusion Using a short gap between warfarin dispensings to define discontinuation may lead to substantial misclassification, which can be improved by incorporating intervening INR codes.
Optimal Tests to Minimise Bleeding and Ischaemic Complications in Patients on Extracorporeal Membrane Oxygenation
Authors: Kanji Rahim , Vandenbriele Christophe , Arachchillage Deepa R. J. , Price Susanna , Gorog Diana Adrienne 
Published: May 2021

AbstractPatients supported with extracorporeal membrane oxygenation (ECMO) experience a very high frequency of bleeding and ischaemic complications, including stroke and systemic embolism. These patients require systemic anticoagulation, mainly with unfractionated heparin (UFH) to prevent clotting of the circuit and reduce the risk of arterial or venous thrombosis. Monitoring of UFH can be very challenging. While most centres routinely monitor the activated clotting time and activated partial thromboplastin time (aPTT) to assess UFH, measurement of anti-factor Xa (anti-Xa) level best correlates with heparin dose, and appears to be predictive of circuit thrombosis, although aPTT may be a better predictor of bleeding. Although monitoring of prothrombin time, platelet count and fibrinogen is routinely undertaken to assess haemostasis, there is no clear guidance available regarding the optimal test.Additional tests, including antithrombin level and thromboelastography, can be used for risk stratification of patients to try and predict the risks of thrombosis and bleeding. Each has their specific role, strengths and limitations. Increased thrombin generation may have a role in predicting thrombosis. Acquired von Willebrand syndrome is frequent with ECMO, contributing to bleeding risk and can be detected by assessing the von Willebrand factor activity-to-antigen ratio, while the platelet function analyser can be used in urgent situations to detect this, with a high negative predictive value. Tests of platelet aggregation can aid in the prediction of bleeding.To personalise management, a selection of complementary tests to collectively assess heparin-effect, coagulation, platelet function and platelet aggregation is proposed, to optimise clinical outcomes in these high-risk patients.
A Step-by-step Sonographic Approach to Vascular Anomalies in the Pediatric Population: A Pictorial Essay
Authors: Mittal Anushka , Anand Rama , Gauba Richa , Choudhury Subhasis Roy , Abbey Pooja 
Published: May 2021

AbstractVascular anomalies are a common cause of soft-tissue masses in children and often referred for ultrasonographic (USG) evaluation. They are broadly classified as vascular tumors (hemangiomas, hemangioendotheliomas, and angiosarcomas) or vascular malformations (venous malformations, lymphatic malformations, and arteriovenous malformations). Findings on USG and Doppler imaging can be used to categorize vascular anomalies into high- or low-flow lesions, which forms the basis for further workup, diagnosis, and management. On careful evaluation of various sonographic features, in conjunction with clinical findings, an accurate clinicoradiological diagnosis can be made in most cases. Further imaging with magnetic resonance (MR) imaging or computed tomography (CT) helps in delineation of lesion extent, whereas MR or CT angiography is useful to map the vascular supply of high-flow lesions. We have illustrated and discussed a step-by-step approach to diagnose vascular anomalies using ultrasound and Doppler imaging.
Design and operation of a portable micro-photoluminescence spectrometer for education on semiconductor quantum structures and graphene sheets
Authors: Heyn Christian 
Published: May 2021

The design and operation of a portable micro-photoluminescence spectrometer for applications in education is described. Guidelines are a compact, robust, portable, and flexible design; operation without cryogenic media for sample cooling; and a limited budget. Targeted samples are semiconductor quantum structures emitting in a wavelength range of 600–1000 nm and graphene sheets. The portable spectrometer includes a reflected-light microscope with a motorized sample stage of 156 nm step size, a thermoelectric sample cooler allowing temperatures down to 196 K, a green and a blue laser for focused excitation, a monochromator with 0.18 nm spectral resolution, and a cooled camera as the image sensor. For demonstration of the capabilities of the spectrometer, measurements of the quantized energy levels of molecular beam epitaxy grown GaAs quantum dots (QDs) are shown. Here, different sample designs are used, the sample temperature as well as the laser excitation power and energy is varied, and the respective influence on the measurements is discussed. A clear QD shell structure with four states is shown for a sample, where approximately four QDs are directly excited by a focused laser. Limitations of the spectrometer for QD characterization mainly due to the waiver of cryogenic media for sample cooling are discussed. As a further example, which does not require sample cooling, local Raman spectroscopy of a graphene sheet is demonstrated where clear Raman signatures allow the identification of a single-layer thickness.
Employing fluorescence analysis for real-time determination of the volume displacement of a pneumatically driven diaphragm micropump
Authors: Bott Hannah , Leonhardt Ronny , Laermer Franz , Hoffmann Jochen 
Published: May 2021

Abstract
In this work, we propose a new optical measurement method and setup to investigate the dynamic behavior of a pneumatically driven diaphragm micropump in a microfluidic system. The presented method allows a contact-free spatially and temporally resolved determination of the membrane displacement. Hence, it enables to derive the volume flow rate, generated by the micropump. The method is based on the Lambert–Beer law, which describes the intensity weakening of light traveling through a medium with an absorbing substance. The fluorescence emission of a medium can thus be related to the light traveling length. The measurement method is used to deduce the flow rate profile generated by the micropump of the Lab-on-Chip system Vivalytic from Bosch Healthcare Solutions. We further quantify effects of fluidic components and system parameters on the transient flow rates. This allows the determination of maximum flow rates and pumping cycle durations as a basis for the implementation of fluidic processes on the system. The presented method requires neither additional, integrated sensor components nor a complex measurement setup. It can be implemented in any microfluidic system with membrane-based, optically accessible micropumps without major hardware modifications.
Bistability of zigzag edge magnetism in graphene nanoribbons induced by electric field
Authors: Luo Ma 
Published: May 2021

Abstract
In the presence of the Hubbard interaction, graphene zigzag nanoribbons have spontaneous edge magnetism with anti-parallel configuration, whose amplitude can be tuned by a transversal electric field. As the electric field increases or decreases across a critical value, the edges are demagnetized or re-magnetized, respectively. A magnetic field at each edge determines the orientation of the re-magnetization. Thus, a combination of a slowly varying transversal electric field and magnetic field in monolayer graphene zigzag nanoribbons can drive the quantum system into a bistability loop. The same phenomenon can be induced in a bilayer/monolayer zigzag nanoribbon without the magnetic field, because the non-symmetry superexchange interaction controls the orientation of the re-magnetization. In this way, the quantum system is switched between ground state and quasi-stable excited state with different magnetism, band structures and conductance. This feature could be used to develop graphene-based spintronic nano-devices without magnetic field.
A mild molecular fusion route for the synthesis of polyhedral carbon nano-onions with high graphitization
Authors: Xie Siyu , Wang Jingyun , He Yongkai , Yan Hao , Wang Yu , Li Yage , Wang Sheng , Sun Xiaodan , Yao Youwei , Cai Qiang 
Published: May 2021

Abstract
Polyhedral carbon nano-onions (CNOs) compared with traditional quasi-spherical CNOs are more stable and have less defects, which will greatly broaden their potential applications. However, there still lacks of a suitable synthetic method. Here, we developed a simple molecular fusion route and templet growth method by which polyhedral CNOs can be successfully synthesized. Characterization of the polyhedral CNOs by transmission electron microscopy, x-ray diffraction and Raman spectroscopy indicates that they have an ultra-high degree of graphitization and a large cavity diameter of about 10 nm, which results in their low density of 1.42 g cm−3. In addition, the deeper reaction mechanism of polyhedral CNOs growth was also elucidated. It was found that the channel structure and the absorption of the templet play the crucial role during the formation of polyhedral CNOs.
Cr cation-anchored carbon nanosheets: synthesis, paramagnetism and ferromagnetism
Authors: Xia Baorui , Zhang Haiyi , Liao Zhongxin , Wu Jian-Feng , Hu Yongfeng , Shakouri Mohsen , Gao Daqiang , Xue Desheng 
Published: May 2021

Abstract
Since the successfully synthesis of monolayer graphene, carbon-based materials have attracted wide and extensive attentions from researches. Due to the excellent transport capacity and conductivity, they are promising to be applied in electronic devices, even substituting the silicon-based electronic devices, optoelectronics and spintronics. Nevertheless, due to the non magnetic feature, many efforts have been devoted to endow carbon materials magnetism to apply them in the spintronic devices fabrication. Herein, a strategy of Cr cation solely anchored on two-dimensional carbon nanosheets by Cr–N bonds is developed, which introduces magnetism in carbon nanosheets. By extended x-ray absorption fine structure characterization, Cr cations are demonstrated to be atomically dispersed with Cr–N3 coordination. And after Cr–N3 anchored, carbon nanosheets exhibit ferromagnetic features with paramagnetic background. The magnetization varies with Cr content and reaches the maximum (Cr: 2.0%, 0.86 emu g−1) under 3 T at 50 K. The x-ray magnetic circular dichroism and first-principle calculations indicate that the magnetism is caused by the Cr3+ component of the anchored Cr cations. This study sets a single cation anchoring carbon as a suitable candidate for future spintronics.
Analytic properties of the complete formal normal form for the Bogdanov–Takens singularity
*
Authors: Stróżyna Ewa , Żołądek Henryk 
Published: May 2021

Abstract
In Stróżyna E and Żołądek H (2015 Moscow Math. J.
15 141) a complete formal normal forms for germs of two-dimensional holomorphic vector fields with nilpotent singularity was obtained. That classification is quite nontrivial (7 cases), but it can be divided into general types like in the case of the elementary singularities. One could expect that also the analytic properties of the normal forms for the nilpotent singularities are analogous to the case of the elementary singularities. This is really true. In the cases analogous to the focus and the node the normal form is analytic. In the case analogous to the nonresonant saddle the normal form is often nonanalytic due to the small divisors phenomenon. In the cases analogous to the resonant saddles (including saddle-nodes) the normal form is nonanalytic due to bad properties of some homological operators associated with the first nontrivial term in the orbital normal form.
Multipartite entanglement purification using time-bin entanglement
Authors: Luo Cheng-Chen , Zhou Lan , Zhong Wei , Sheng Yu-Bo 
Published: May 2021

Abstract
Multipartite entanglement has been widely employed in quantum information processing. However, the unavoidable noise in quantum channels causes the maximally multipartite entangled state to degrade to the mixed state. In this paper, we propose a highly efficient multipartite entanglement purification protocol (MEPP) for the polarization Greenberger–Horne–Zeilinger state. Unlike conventional MEPPs, where two pairs of polluted entanglement are usually required, our protocol only requires one noisy copy of polarization-time-bin hyperentanglement and exploits the time-bin entanglement to purify the polarization entanglement. This feature increases the efficiency of our MEPP. Our MEPP may have potential applications in long-distance quantum communication.
Effect of the anionic center hydration on the activation barrier of intramolecular nucleophilic addition in αβ-unsaturated oximes
Authors: Pradedova A G , Kobychev V B 
Published: May 2021

AbstractThe mechanism of intramolecular nucleophilic addition in αβ-unsaturated oximes, as well as the effect of the anionic center hydration with one and two water molecules on the activation barriers of intramolecular cyclization, was studied using the B2PLYP-D2/6-311+G**//B3LYP(D)/6-31+G* method with the solvation effects included within the SMD model. The activation barrier for nucleophilic addition of the anionic center of the oxime group to the carbon skeleton of 3-ethyl-N-hydroxy-5-phenylpenten-3-imine-2 is about 21 kcal/mol. During the hydration of the anionic center with one water molecule, a strong complex is formed, which increases the activation barrier by ∼ 6 kcal / mol. The addition of a second water molecule leads to an even higher activation barrier (ΔG‡ = 28 kcal/mol), but promotes the binding of the leaving hydroxide ion.