bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental dissemination of pathogenic Listeria monocytogenes in flowing surface waters in Switzerland
Authors: Raschle Susanne , Stephan Roger , Stevens Marc J. A. , Cernela Nicole , Zurfluh Katrin , Muchaamba Francis , Nüesch-Inderbinen Magdalena
Published: April 2021

Listeria monocytogenes is an opportunistic pathogen that is widely distributed in the environment. The aquatic environment may represent a potential source for the transmission of L. monocytogenes to animals and the food chain. The present study assessed the occurrence of L. monocytogenes in 191 surface water samples from rivers, streams and inland canals throughout Switzerland. Twenty-five (13%) of the surface water samples contained L. monocytogenes. Whole genome sequence (WGS) data were used to characterize the 25 isolates. The isolates belonged to major lineages I and II, with the majority assigned to either serotype 1/2a (48%), or 4b (44%). The predominant CCs identified were the hypervirulent serotype 4b clones CC1 and CC4, and the serotype CC412; all three have been implicated in listeriosis outbreaks and sporadic cases of human and animal infection worldwide. Two (8%) of the isolates belonged to CC6 which is an emerging hypervirulent clone. All isolates contained intact genes associated with invasion and infection, including inlA/B and prfA. The four CC4 isolates all harbored Listeria pathogenicity island 4 (LIPI-4), which confers hypervirulence. The occurrence of L. monocytogenes in river ecosystems may contribute to the dissemination and introduction of clinically highly relevant strains to the food chain.
Comparison of the clinical outcomes of skin bridge loop ileostomy and traditional loop ileostomy in patients with low rectal cancer
Authors: Ye Hui , Huang Shujuan , Yu Jie , Zhou Qichang , Xi Changlei , Cao Longlei , Wang Peiyun , Shen Jie , Gong Zhilin
Published: April 2021

To compare the clinical results of patients with low rectal cancer who underwent skin bridge loop ileostomy and traditional loop ileostomy, and provide clinical evidence for choosing a better ostomy method. We retrospectively collected data of 118 patients with rectal cancer who underwent low anterior resection and loop ileostomy. To investigate the patients characteristics, postoperative stoma-related complications and the frequency of exchanged ostomy bags. The differences of these indicators between the two groups of patients who underwent skin bridge loop ileostomy and traditional loop ileostomy were compared. The Visual Analog Scale (VAS) score of the skin bridge loop ileostomy group was lower than that of the traditional ileostomy loop group (P < 0.05). The skin bridge group had a lower Discoloration, Erosion, Tissue overgrowth (DET) score and incidence of mucocutaneous separation than the traditional group at the 1st and 2nd weeks after operation (P < 0.05). The average number of weekly exchanged ostomy bags was significantly less in the skin bridge group than in the traditional group within 4 weeks after surgery (P < 0.05). Our experience demonstrates that the skin bridge loop ileostomy may significantly reduce early postoperative stoma-related complications, the frequency of exchanged ostomy bags and patients’ medical costs after discharge.
Tumor mutation burden (TMB)-associated signature constructed to predict survival of lung squamous cell carcinoma patients
Authors: Yan Dan , Chen Yi
Published: April 2021

Lung squamous cell carcinoma (LUSC) is a common type of lung cancer with high incidence and mortality rate. Tumor mutational burden (TMB) is an emerging biomarker for selecting patients with non-small cell lung cancer (NSCLC) for immunotherapy. This study aimed to reveal TMB involved in the mechanisms of LUSC and develop a model to predict the overall survival of LUSC patients. The information of patients with LUSC were obtained from the cancer genome atlas database (TCGA). Differentially expressed genes (DEGs) between low- and the high-TMB groups were identified and taken as nodes for the protein–protein interaction (PPI) network construction. Gene oncology (GO) enrichment analysis and gene set enrichment analysis (GSEA) were used to investigate the potential molecular mechanism. Then, we identified the factors affecting the prognosis of LUSC through cox analysis, and developed a risk score signature. Kaplan–Meier method was conducted to analyze the difference in survival between the high- and low-risk groups. We constructed a nomogram based on the risk score model and clinical characteristics to predict the overall survival of patients with LUSC. Finally, the signature and nomogram were further validated by using the gene expression data downloaded from the Gene Expression Omnibus (GEO) database. 30 DEGs between high- and low-TMB groups were identified. PPI analysis identified CD22, TLR10, PIGR and SELE as the hub genes. Cox analysis indicated that FAM107A, IGLL1, SELE and T stage were independent prognostic factors of LUSC. Low-risk scores group lived longer than that of patients with high-risk scores in LUSC. Finally, we built a nomogram that integrated the clinical characteristics (TMN stage, age, gender) with the three-gene signature to predict the survival probability of LUSC patients. Further verification in the GEO dataset. TMB might contribute to the pathogenesis of LUSC. TMB-associated genes can be used to develope a model to predict the OS of lung squamous cell carcinoma patients.
A cross-sectional analysis of the association between sleep duration and osteoporosis risk in adults using 2005–2010 NHANES
Authors: Lee Chia-Lin , Tzeng Huey-En , Liu Wei-Ju , Tsai Chun-Hao
Published: April 2021

Controversy remains regarding the relationship between bone health and sleep. In the literature, the effect of sleep on bone density in the clinical setting varies depending on the definition of normal sleep duration, sleep quality, selected population, and diagnostic tools for bone density. The aim of this study was to examine the association between bone mineral density (BMD)assessed by dual-energy X-ray absorptiometry and sleep duration/quality in the defined adult population from the National Health and Nutrition Examination Survey (NHANES) (a national household survey) within a 6-year period (2005–2010) and explore age differences. The basic variables, metabolic diseases, and bone density in the femoral neck as determined through dual-energy X-ray absorptiometry, were segregated, and analyzed according to different sleep durations (1–4, 5–6,7–8, and > 9 h/day) and sleep quality using multinomial regression models. A total of 12,793 subjects were analyzed. Our results reveal that women aged > 50 years with sleep duration < 5 h/day had a 7.35 (CI 3.438–15.715) odds of osteoporosis than those in other groups. This analysis is based on a nationally representative sample using survey and inspection data and clarifies the relationship between bone density and the effect of the combination of sleep quality and duration.
Viscoelasticity of non-colloidal hydrogel particle suspensions at the liquid–solid transition
Authors: Shewan Heather M. , Yakubov Gleb E. , Bonilla Mauricio R. , Stokes Jason R.
Published: April 2021

The liquid–solid transition occurs across a viscoelastic–liquid regime for non-colloidal, polydisperse, frictional soft hydrogel particle suspensions converse to the discrete transition expected for these suspensions of large particles.
Molecular engineering in a family of pillared-layered metal–organic frameworks for tuning gas adsorption behavior
Authors: Liang Shuai , Ge Fa-Yuan , Ren Shuang-Shuang , Lei Ming-Yuan , Gao Xiang-Jing , Zheng He-Gen
Published: April 2021

Three Co-based MOFs were obtained via a mixed-ligand strategy. One of them performs an extra high CO2/N2 selectivity because of a negligible N2 adsorption, which originate from a weak interaction between its framework and nitrogen molecules.
Unusual mechanism of paramagnetic nickel-catalysed α-alkylation of amides
Authors: Du Chao , Zhou Xiaoyu , Li Weikang , Wen Xiuling , Ke Zhuofeng , Zhao Cunyuan
Published: April 2021

Nickel transition-metal catalysts are important materials which are widely used in (de)hydrogenation reactions.
Advancedin situtechnology for Li/Na metal anodes: an in-depth mechanistic understanding
Authors: Pu Jun , Zhong Chenglin , Liu Jiahao , Wang Zhenghua , Chao Dongliang
Published: April 2021

Advancedin situtechnologies for understanding the mechanism of Li/Na metal anodes includingin situreactions, to form a specific interface layer andin situcharacterization to capture transient metastable information continuously as a function of time.
Fe1N4–O1 site with axial Fe–O coordination for highly selective CO2 reduction over a wide potential range
Authors: Chen Zhiqiang , Huang Aijian , Yu Ke , Cui Tingting , Zhuang Zewen , Liu Shoujie , Li Jianzhan , Tu Renyong , Sun Kaian , Tan Xin , Zhang Jiaqi , Liu Di , Zhang Yu , Jiang Peng , Pan Yuan , Chen Chen , Peng Qing , Li Yadong
Published: April 2021

The proposed working mechanism of the electrochemical CO2 reduction reaction on Fe1N4, Fe1N4–N1, and Fe1N4–O1 active sites.
Sensitivity improvement of solution cathode glow discharge-atomic emission spectrometry by using refrigerating anodes for optical determination of metal elements
Authors: Zheng Peichao , Luo Yuanjiang , Wang Jinmei , Hu Qiang , Yang Yang , Mao Xuefeng , Lai Chunhong
Published: April 2021

Sensitivity and stability improvement by reducing the metal anode temperature for metal element detection using SCGD-AES.
Improved photophysical properties and durability of CsPbBr3 NCs endowed by inorganic oxoacid and bromide ions
Authors: Chen Shuhua , Zhong Qixuan , Liu Jun , Guan Wenhao , Li Pengli , Mahmood Israr , Cao Muhan , Zhang Qiao
Published: April 2021

Inorganic phosphate and bromide ions are employed to enhance the quantum yield and stability of CsPbBr3 NCs.
Room temperature synthesis of Sn2+doped highly luminescent CsPbBr3quantum dots for high CRI white light-emitting diodes
Authors: Yan Dongdong , Mo Qionghua , Zhao Shuangyi , Cai Wensi , Zang Zhigang
Published: April 2021

Room temperature synthesis of Sn2+ doped CsPbBr3 QDs show a high PLQY of 82.77% and their corresponding WLEDs exhibit a CRI of 89 and a CCT of 3954.
Die ambulante Suchthilfe im Wandel der Zeit –
Veränderungen von Klientel, Problembereichen und Betreuungsergebnis
zwischen 2007 und 2016
Authors: Dauber Hanna , Braun-Michl Barbara , Specht Sara , Künzel Jutta , Schwarzkopf Larissa
Published: April 2021

Ziel Dieser Beitrag untersucht anhand der Daten der Deutschen
Suchthilfestatistik (DSHS) welche Veränderungen sich in der ambulanten
Suchthilfe hinsichtlich Klientel, Hauptdiagnosen und Betreuungsergebnis im
Zeitraum von 2007 bis 2016 ergeben haben. Die beobachteten Trends werden vor dem
Hintergrund sich wandelnder gesamtgesellschaftlicher und versorgungspolitischer
Rahmenbedingungen reflektiert.

Material und Methoden Aggregierte Daten aller ambulanten
Suchthilfeeinrichtungen, die sich im genannten Zehnjahreszeitraum an der DSHS
beteiligt haben, wurden deskriptiv ausgewertet. Neben der Entwicklung des
Betreuungsvolumens beschreiben die Analysen soziodemografische,
störungs- und betreuungsrelevante Parameter im Zeitverlauf.

Ergebnisse Die Anzahl teilnehmender Einrichtungen (2007: n=720;
2016: n=863) ist im untersuchten Zeitraum gestiegen. Neben einigen
soziodemografischen Merkmalen (zunehmendes Durchschnittsalter, steigender
Frauenanteil, höheres Bildungsniveau) hat sich insbesondere die
Zusammensetzung der Hauptdiagnosen verändert. Trotz stark
rückläufigem Anteil (2007: 57,3%; 2016: 48,9%)
repräsentieren alkoholbezogene Störungen nach wie vor den
häufigsten Betreuungsanlass. Bei opioidbezogenen Störungen ist
ebenfalls ein Rückgang zu verzeichnen (2007: 18,6%, 2016:
13,7%), während cannabis-bezogene Störungen deutlich
zugenommen haben (2007: 12,1%, 2016: 17,8%). Der Anteil
positiver Betreuungsergebnisse war konstant hoch (2007: 64,5%, 2016:
64,1%).

Diskussion Die konstant positiven Betreuungsergebnisse deuten darauf hin,
dass auf veränderte Bedarfe der Suchthilfeklientel in richtigem
Maße reagiert wurde. Perspektivisch ist von einem Bedeutungszuwachs der
älteren Klientel sowie von Menschen mit Migrationshintergrund in der
Suchthilfe auszugehen, was annahmegemäß weitere Anpassungen des
Angebots nach sich ziehen dürfte.
Lifestyle Influences Changes in Fibrin Clot Properties Over a 10-Year Period on a Population Level
Authors: Swanepoel Albe Carina , de Lange-Loots Zelda , Cockeran Marike , Pieters Marlien
Published: April 2021

Case–control and observational studies have provided a plausible mechanistic link between clot structure and thrombosis. We aimed to identify lifestyle, demographic, biochemical, and genetic factors that influence changes in total fibrinogen concentration and clot properties over a 10-year period in 2,010 black South Africans. Clot properties were assessed with turbidimetry and included lag time, slope, maximum absorbance, and clot lysis time. Linear mixed models with restricted maximum likelihood were used to determine whether (1) outcome variables changed over the 10-year period; (2) demographic and lifestyle variables, biochemical variables, and fibrinogen single-nucleotide polymorphisms influenced the change in outcome variables over the 10-year period; and (3) there was an interaction between the exposures and time in predicting the outcomes. A procoagulant risk score was furthermore created, and multinomial logistic regression was used to determine the exposures that were associated with the different risk score categories. In this population setting, female gender, obesity, poor glycemic control, increased low-density lipoprotein cholesterol, and decreased high-density lipoprotein cholesterol contributed to the enhanced progression to prothrombotic clot properties with increasing age. Alcohol consumption on the other hand, offered a protective effect. The above evidence suggest that the appropriate lifestyle changes can improve fibrin clot properties on a population level, decreasing cardiovascular disease risk and thus alleviate the strain on the medical health care system.
A Rare Case of Myocardial Infarction with Nonobstructive Coronary Arteries Due to Hereditary Thrombophilia
Authors: Arivazhagan Ramesh Bala , Chinnusamy Manokaran , Sarojadevi Ashida Thulaseedharan , Janakiraman Sathiyanarayanan
Published: April 2021

The incidence of acute myocardial infarction with nonobstructive coronary arteries in young age less than 20 years in India due to hereditary thrombophilia is uncommon. Combined protein S and protein C deficiency has an increased tendency for coronary artery thrombosis in very young individuals. Acute myocardial infarction in young individuals has different risk factors profile, clinical presentation, and prognosis when compared with elderly population and hence incites the need for different approach in the management. Here we report a case of 17-year-old boy who presented with acute inferior wall myocardial infarction with nonobstructive coronary arteries due to hereditary protein C and protein S deficiency.
Extended Perinatal Mortality Audit in a Rural Hospital in India
Authors: Torre Monmany Núria , Astete Joaquín Américo , Ramaiah Dasarath , Suchitra Jyothi , Krauel Xavier , Fillol Manolo , Balasubbaiah Yadamala , Alarcón Ana , Bassat Quique
Published: April 2021

Objective The aim of the study is to describe the status of perinatal mortality (PM) in an Indian rural hospital.

Study Design Retrospective analysis of data was compiled from PM meetings (April 2017 to December 2018) following “Making Every Baby Count: audit and review of stillbirths and neonatal deaths (ENAP or Every Newborn Action Plan).”

Results The study includes 8,801 livebirths, 105 stillbirths (SBs); 74 antepartum stillbirths [ASBs], 22 intrapartum stillbirths [ISBs], and nine unknown timing stillbirths [USBs]), 39 neonatal deaths or NDs (perinatal death or PDs 144). The higher risks for ASBs were maternal age >34 years, previous history of death, and/or SBs. Almost half of the PDs could be related with antepartum complications. More than half of the ASB were related with preeclampsia/eclampsia and abruptio placentae; one-third of the ISB were related with preeclampsia/eclampsia and gestational hypertension, fetal growth restriction, and placental dysfunction. The main maternal conditions differed between PDs (p = 0.005). The main causes of the ND were infections, congenital malformations, complications of prematurity, intrapartum complications, and unknown. The stillbirth rate was 11.8/1,000 births, neonatal mortality rate 4.4/1,000 livebirths, and perinatal mortality rate 15.8/1,000 births.

Conclusion This is the first study of its kind in Andhra Pradesh being the first step for the analysis and prevention of PM.

Key Points
Exploiting the dividend month premium: evidence from Germany
Authors: Kreidl Felix , Scholz Hendrik
Published: April 2021

Dividend payments are firm events on a recurring and predictable basis. High returns in the period between announcement-date and ex-dividend date are the main driver for the so-called dividend month premium, which are positive abnormal returns in months in which corporations are predicted to issue dividend payments. In our empirical analysis of the German stock market, we find a robust dividend month premium, which is particularly high for stocks with positive dividend surprise. Knowing the dates of dividend announcements and payments enable portfolio managers to exploit the dividend month premium. Also taking into account tracking error and transaction costs, we show that simple portfolio-enhancing strategies lead to highly significant abnormal returns.
Fantastic barocalorics and where to find them
Authors: Boldrin David
Published: April 2021

Barocaloric materials have the potential to offer greener and more efficient alternatives to conventional refrigerants that exploit vapor compression for cooling and heating applications. The barocaloric effect, a temperature change in response to hydrostatic pressure, is widespread in materials; however, only in the last few years have giant and colossal barocaloric effects approaching those of commercial hydrocarbon refrigerants been discovered. These barocaloric effects are associated with large changes in the degrees of freedom within the material and can take various forms. Here, we discuss this variety and categorize barocaloric materials based on the degree of freedom that underpins the barocaloric effects. We use this framework to identify material families to explore for potential barocalorics.
Synaptic behavior of Ni–Co layered double hydroxide-based memristor
Authors: He Nian , Sun Yanmei , Wen Dianzhong
Published: April 2021

The synaptic behavior of the Ni–Co layered double hydroxide-based memristor was demonstrated. The modulation effect of pulse amplitude, duration, and excitation interval on the conductance of memristor is analyzed. On account of analog resistive switching features, and the nonlinear transmission characteristics of synapses, pulse-time-dependent plasticity, long-term/short-term memory, and “learning” and “forgetting” behaviors of synapses are simulated and carried out. The analog bipolar resistance switch was ascribed to the formation and breakdown of oxygen filaments formed in Ni–Co layered double hydroxides films. This kind of memristor with an analog resistance switch is very promising to provide an implementation method for the development of electronic synapse function.
Logical devices based on the antiferromagnetic-antimeron in a ferromagnet nanodot with gain
Authors: Ji Lianze , Zhao Rongzhi , Hu Chenglong , Chen Wenchao , Li Yixing , Ren Kun , Chen Yimin , Zhang Xuefeng
Published: April 2021

The antiferromagnetic spintronics is attracting intensive attention due to the recent progress of antiferromagnetism. Especially, the topological magnetic structures, discovered in the antiferromagnetic materials, have opened an alternative path for energy efficient information processing, e.g., constructing logical devices. Herein, we theoretically extend the building block of spintronics devices by utilizing the antiferromagnetic-antimeron, which can be formed in ferromagnet nanodots with gain. A rotational mode of the antiferromagnetic-antimeron is observed under the injection of spin polarized current that originates from the excitation of spin waves propagating along the radial normal of the nanodots. The frequency of rotation (f) can be analytically calculated, expressed in the form of f∝kJα, where k is a proportionality coefficient, and J and α are the current density and Gilbert damping, respectively. The value of f is proportional to the current density (J), but inversely proportional to α. Finally, the logical gates based on the antiferromagnetic-antimeron are proposed for Boolean logic operation of OR, XOR, XNOR, and AND. Utilizing the unique dynamic behaviors of the antiferromagnet-antimeron under the injection of current sheds light on the development of the building block of spintronics devices.
Recognition of individual scatterers against the noise background in the optical coherence tomography image
Authors: Shilyagin P.A. , Novozhilov A.A. , Dilenyan A.L. , Vasilenkova T.V. , Moiseev A.A. , Kasatkina I.V. , Gelikonov V.M. , Gelikonov G.V.
Published: April 2021

The problem of recognising single sparsely located scatterers against the noise background in the image obtained by the method of optical coherence tomography (OCT) is considered. An identification method based on the use of specific scanning features upon OCT image registration and on the statistical analysis of image fragments is proposed. The efficiency of the method is demonstrated experimentally in the diagnosis of otitis media with effusion. The approach can be used in the development of automated algorithms for determining the presence of highly transparent effusion in the middle ear cavity of a human with acute otitis media with effusion, including postoperative one.
Near-IR lasing in caesium vapour
Authors: Babin A.A. , Volkov M.V. , Garanin S.G. , Kovaldov S.A. , Kopalkin A.V. , Kulikov S.M. , Nosov S.N. , Starikov F.A. , Strakhov A.V. , Feoktistov V.V. , Shotniev V.A.
Published: April 2021

Lasing in caesium vapour is obtained at λ ∼ 3 μm (transitions 7P3/2 → 7S1/2 and 7P1/2 → 7S1/2). Longitudinal pumping is performed by the second harmonic of a parametric oscillator pumped by the second harmonic of a Nd3+-doped garnet laser. The pump wavelength corresponds to the 6S1/2 → 7P3/2 and 6S1/2 → 7P1/2 transitions of caesium atoms. The pump radiation has a spectral width of 12 cm−1, a pulse energy of 10 mJ, and a pulse repetition rate of 10 Hz. The IR laser pulse energy at a vapour cell temperature of 155 °C is 100 μJ. The efficiency of pump energy conversion to the laser radiation energy at λ ∼ 3 μm is ∼1.5%.
Classification of non-Kähler surfaces and locally conformally Kähler geometry
Authors: Verbitsky M. S. , Vuletescu V. , Ornea L.
Published: April 2021

The Enriques–Kodaira classification treats non-Kähler surfaces as a special case within the Kodaira framework. We prove the classification results for non-Kähler complex surfaces without relying on the machinery of the Enriques–Kodaira classification, and deduce the classification theorem for non-Kähler surfaces from the Buchdahl–Lamari theorem. We also prove that all non-Kähler surfaces which are not of class VII are locally conformally Kähler.

Bibliography: 64 titles.
On the resolution of singularities of one-dimensional foliations on three-manifolds
Authors: Rebelo J. C. , Reis H.
Published: April 2021

This paper is devoted to the resolution of singularities of holomorphic vector fields and one-dimensional holomorphic foliations in dimension three, and it has two main objectives. First, within the general framework of one-dimensional foliations, we build upon and essentially complete the work of Cano, Roche, and Spivakovsky (2014). As a consequence, we obtain a general resolution theorem comparable to the resolution theorem of McQuillan–Panazzolo (2013) but proved by means of rather different methods.

The other objective of this paper is to consider a special class of singularities of foliations containing, in particular, all the singularities of complete holomorphic vector fields on complex manifolds of dimension three. We then prove that a much sharper resolution theorem holds for this class of holomorphic foliations. This second result was the initial motivation for this paper. It relies on combining earlier resolution theorems for (general) foliations with some classical material on asymptotic expansions for solutions of differential equations.

Bibliography: 34 titles.
Genetic removal of p70 S6K1 corrects coding sequence length-dependent alterations in mRNA translation in fragile X syndrome mice
Authors: Aryal Sameer , Longo Francesco , Klann Eric
Published: April 2021

Significance

Fragile X syndrome (FXS) is the most prevalent inherited form of intellectual disability. FXS is caused by loss of fragile X mental retardation protein (FMRP), an RNA-binding protein that represses translation. Correspondingly, genetic removal of the translation-stimulating p70 S6 kinase 1 (S6K1) in FXS mice restores translational homeostasis and rescues synaptic and behavioral phenotypes. However, the mechanisms of FMRP function are in dispute, and the molecular basis of the rescue in protein synthesis with reduction of S6K1 is unknown. Here, by carrying out ribosome profiling and molecular assays, we reveal the molecular mechanisms by which reduction of S6K1 corrects altered protein synthesis in FXS. Our study elucidates the molecular foundations of a model for correction of pathophysiological features of FXS.
Communication consumes 35 times more energy than computation in the human cortex, but both costs are needed to predict synapse number
Authors: Levy William B , Calvert Victoria G.
Published: April 2021

Significance

Engineers describe the human brain as a low-energy form of computation. However, from the simplest physical viewpoint, a neuron’s computation cost is remarkably larger than the best possible bits per joule—off by a factor of108. Here we explicate, in the context of energy consumption, a definition of neural computation that is optimal given explicit constraints. The plausibility of this definition as Nature’s perspective is supported by an energy audit of the human brain. The audit itself requires modifying conventional perspectives and calculations revealing that communication costs are 35-fold computational costs.
Highly efficient BiVO4 single-crystal nanosheets with dual modification: phosphorus doping and selective Ag modification
Authors: Fu Can , Xu Baoyun , Dong Lingling , Zhai Jinguo , Wang Xuefei , Wang De-Yi
Published: April 2021

BiVO4, a visible-light response photocatalyst, has shown tremendous potential because of abundant raw material sources, good stability and low cost. There exist some limitations for further applicaitions due to poor capability to separate electron–hole pairs. In fact, a single-component modification strategy is barely adequate to obtain highly efficient photocatalytic performance. In this work, P substituted some of the V atoms from VO4 oxoanions, namely P was doped into the V sites in the host lattice of BiVO4 by a hydrothermal route. Meanwhile, Ag as an attractive and efficient electron-cocatalyst was selectively modified on the (010) facet of BiVO4 nanosheets via facile photo-deposition. As a result, the obtained dually modified BiVO4 sheets exhibited enhanced photocatalytic degradation property of methylene blue (MB). In detail, photocatalytic rate constant (k) was 2.285 min−1 g−1, which was 2.78 times higher than pristine BiVO4 nanosheets. Actually, P-doping favored the formation of O vacancies, led to more charge carriers, and facilitated photocatalytic reaction. On the other hand, metallic Ag loaded on (010) facet effectively transferred photogenerated electrons, which consequently helped electron–hole pairs separation. The present work may enlighten new thoughts for smart design and controllable synthesis of highly efficient photocatalytic materials.
Hybrid supercapacitors using electrodes from fibers comprising polymer blend–metal oxide composites with polymethacrylic acid as chelating agent
Authors: Malekpour Soheil , Balkus Kenneth J , Ferraris John P
Published: April 2021

Hybrid supercapacitors (SCs) made of carbon–metal oxide composites are devices which combine the advantages of electric double layer capacitors and pseudocapacitors viz high energy density, high power density and high cyclability. This is best achieved when the pseudocapacitive components are uniform in size and distribution on the conducting carbon support. Electrodes mats, fabricated from carbonized electrospun fibers generated from solutions of polyacrylonitrile (PAN) as the carbon source, cobalt (III) acetylacetonate as a metal oxide precursor, and polymethacrylic acid (PMAA) as a metal oxide precursor carrier were utilized in coin cell SCs. Fibers without the PMMA carrier were prepared for comparison. XRD and TGA showed conversion of the cobalt precursor to a mixture of cobalt and cobalt oxide (Co3O4). When the PMAA carrier was used, specific capacitance increased from 68 F g−1 in PAN-Co3O4 to 125 F g−1 in PAN-PMAA-Co3O4. The addition of PMAA to the system results in better uniformity, accessibility and dispersion of metal and metal oxide particles. Due to the relatively low surface area of carbonized samples, Co3O4 nanoparticles are the primary contributors to charge storage. The fabricated fibers show an energy density of 8.9 at 750 W kg−1, which is twice that of the fibers made without PMAA.
Catalog of x-ray spectra of Mo-, Rh-, and W-anode-based x-ray tubes from 10 to 50 kV
Authors: Ketelhut Steffen , Büermann Ludwig , Hilgers Gerhard
Published: April 2021

This work presents a comprehensive catalog of x-ray spectra measured from x-ray tubes with tungsten, molybdenum, and rhodium anodes generated at tube potentials between 10 and 50 kV in steps of 1 kV. They can serve as an input for dose calculations, image quality calculations, investigations of detector features, and validations of computational spectral models, among other things. The measurements are performed by means of a high-purity germanium detector-based spectrometer 1 m from the x-ray sources without any added filtration. The x-ray tubes are characterized by thin beryllium exit windows (0.15−4 mm); thus, for energies above 15 keV, the spectra recorded can be considered approximately unfiltered. This allows potential users of the catalog to computationally add any filter to the spectra in order to create special radiation qualities of their choice. To validate this option, a small number of spectra are recorded with filter materials in place whose purity and thickness are known with high precision. These spectra are compared to the corresponding spectra from the catalog obtained by means of computationally added filters. The two types of spectra agree extremely well. Several typical mammographic radiation qualities are selected to compare the spectra obtained from the catalog presented here with corresponding spectra obtained from other catalogs published by Boone et al (1997 Med. Phys.
24 1863–74) and Hernandez et al (2017 Med. Phys.
44 2148–60). In contrast to the work presented here, those spectra rely partly or fully on calculations. A quantitative comparison is made by means of typical x-ray quality descriptors such as the mean energy and the first and second half-value layer. The results obtained from the Boone catalog match those of the current catalog sufficiently well for the Mo- and Rh-anode-based spectra. However, significant differences up to 10 times the estimated uncertainties are found for the quality descriptors evaluated from the spectra of Hernandez et al and the W-anode based spectra of Boone et al.
Low activity [11C]raclopride kinetic modeling in the mouse brain using the spatiotemporal kernel method
Authors: Miranda Alan , Bertoglio Daniele , Stroobants Sigrid , Staelens Steven , Verhaeghe Jeroen
Published: April 2021

Depending on the molar activity of the tracer, the maximal allowable injected activity in mouse brain PET studies can be extremely low in order to avoid receptor saturation. Therefore, a high level of noise can be present in the image. We investigate several dynamic PET reconstruction methods in reduced counts, or equivalently in reduced injected activity, data exemplified in [11C]raclopride BP
ND and

R

1

quantification using the simplified reference tissue model (SRTM). We compared independent frame reconstruction (IFR), post-reconstruction HYPR denoising (IFR + HYPR), direct reconstruction using the SRTM model (DIR-SRTM), and the spatial (KERS) and spatiotemporal kernel reconstruction (KERST). Additionally, HYPR denoising of the frames used as features for the calculation of the spatial kernel matrix, was investigated (KERS-HYPR and KERST-HYPR). In vivo data of 11 mice, was used to generate list-mode data for five reduced count levels corresponding to reductions by a factor 4, 8, 12, 16 and 32 (equivalently 2.07, 1.04, 0.691, 0.518, and 0.260 MBq). Correlation of regional BP
ND and

R

1

values (reduced versus full counts reconstructions) was high (r > 0.94) for all methods, with KERS-HYPR and KERST-HYPR reaching the highest correlation (r > 0.96). Among methods with regularization, DIR-SRTM showed the largest variability in BP
ND (Bland–Altman SD from 3.0% to 12%), while IFR showed it for

R

1

(5.1%–14.6%). KERST and KERST-HYPR were the only methods with Bland–Altman bias and SD below 5% for noise level up to a reduction factor of 16. At the voxel level, BP
ND and

R

1

correlation was gradually decreased with increasing noise, with the largest correlation (BP
ND
r > 0.88,

R

1

r > 0.62) for KERS-HYPR and KERST-HYPR. The spatial and the spatiotemporal kernel methods performed similarly, while using only temporal regularization with direct reconstruction showed more variability. Although R1 values present noise, using the spatiotemporal kernel reconstruction, accurate estimates of binding potential could be obtained with mouse injected activities as low as 0.26–0.518 MBq. This is desirable in order to maintain the tracer kinetics principle in mouse studies.
Performance evaluation of a staggered three-layer DOI PET detector using a 1 mm LYSO pitch with PETsys TOFPET2 ASIC: comparison of HAMAMATSU and KETEK SiPMs
Authors: Binder Tim , Kang Han Gyu , Nitta Munetaka , Schneider Florian , Yamaya Taiga , Parodi Katia , Wiest Florian , Thirolf Peter G
Published: April 2021

In this study, we propose a staggered three-layer depth-of-interaction (DOI) detector with a 1 mm crystal pitch and 19.8 mm total crystal thickness for a high-resolution and high-sensitivity small animal in-beam PET scanner. A three-layered stacked LYSO scintillation array (0.9 × 0.9 × 6.6 mm3 crystals, 23 × 22 mm2 surface area) read out by a SiPM array (8 × 8 channels, 3 × 3 mm2 active area/channel and 50 μm microcell size) with data acquisition, signal processing and digitization performed using the PETsys Electronics Evaluations kit (based on the TOFPET v2c ASIC) builds a DOI LYSO detector block. The performance of the DOI detector was evaluated in terms of crystal resolvability, energy resolution, and coincidence resolving time (CRT). A comparative performance evaluation of the staggered three-layer LYSO block was conducted with two different SiPM arrays from KETEK and HAMAMATSU. 100% (KETEK) and 99.8% (HAMAMATSU) of the crystals were identified, by using a flood irradiation the front- and back-side. The average energy resolutions for the 1st, 2nd, and 3rd layers were 16.5 (±2.3)%, 20.9(±4.0)%, and 32.7 (±21.0)% (KETEK) and 19.3 (±3.5)%, 21.2 (±4.1)%, and 26.6 (±10.3)% (HAMAMATSU) for the used SiPM arrays. The measured CRTs (FWHM) for the 1st, 2nd, and 3rd layers were 532 (±111) ps, 463 (±108) ps, and 447 (±111) ps (KETEK) and 402 (±46) ps, 392 (±54) ps, and 408 (±196) ps (HAMAMATSU). In conclusion, the performance of the staggered three-layer DOI detector with 1 mm LYSO pitch and 19.8 mm total crystal thickness was fully characterized. The feasibility of a highly performing readout of a high resolution DOI PET detector via SiPM arrays from KETEK and HAMAMATSU employing the PETsys TOFPET v2c ASIC could be demonstrated.
Automated test setup to quantify the lifetime of dielectric elastomer actuators under a wide range of operating conditions
Authors: Kühnel Djen , Beco Albuquerque Fabio , Py Valentin , Shea Herbert
Published: April 2021

We present an automated test setup for the systematic performance and lifetime evaluation of dielectric elastomer actuators (DEAs). This setup, called the MAPLE setup, performs accelerated aging tests and allows quantifying how material choice, fabrication methods, voltage waveform, and environmental conditions influence DEA lifetime, an important step for commercial use of DEAs. The setup continuously monitors strain and electrode resistance of multiple DEAs under a wide range of environmental conditions (up to 85 °C and 85% relative humidity), with automatic breakdown detection to record device lifetime. To illustrate a use case, we investigate the lifetime of DEAs made of two different elastomer materials, comparing fixed polarity (FP) vs. periodically reversing the polarity of the actuation voltage. For DEAs made from a slide-ring material, lifetime improvements around 10× were observed at alternating polarity compared to FP. For DEAs made from silicone rubber, no improvement in lifetime was observed. This indicates that different degradation mechanisms are causing failure in the two materials.
Transient dynamics of the quantum light retrieved from Rydberg polaritons
Authors: Padrón-Brito Auxiliadora , Tricarico Roberto , Farrera Pau , Distante Emanuele , Theophilo Klara , Chang Darrick , de Riedmatten Hugues
Published: April 2021

We study the photon statistics of weak coherent pulses propagating through a cold atomic ensemble in the regime of Rydberg electromagnetically induced transparency. We show experimentally that the value of the second-order autocorrelation function of the transmitted light strongly depends on the position within the pulse and heavily varies during the transients of the pulse. In particular, we show that the falling edge of the transmitted pulse displays much lower values than the rest of the pulse. We derive a theoretical model that quantitatively predicts our results and explains the physical behavior involved. Finally, we use this effect to generate single photons localized within a pulse. We show that by selecting only the last part of the transmitted pulse, the single photons show an antibunching parameter as low as 0.12 and a generation efficiency per trial larger than that possible with probabilistic generation schemes based on atomic ensembles.
Searching for γ-ray emission from LOTAAS pulsars
Authors: Lu Qi-Wei , Wang Zhong-Xiang , Xing Yi
Published: April 2021

The LOw-Frequency ARray (LOFAR) has recently conducted a survey (LOFAR Tied-Array Allsky Survey; LOTAAS) for pulsars in the Northern hemisphere that resulted in discoveries of 73 new pulsars. For the purpose of studying the properties of these pulsars, we search for their γ-ray counterparts using the all-sky survey data obtained with the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope (Fermi). We analyze the LAT data for 70 LOTAAS pulsars (excluding two millisecond pulsars and one with the longest known spin period of 23.5 s). We find one candidate counterpart to PSR J1017+30, which should be searched for the γ-ray pulsation signal once its timing solution is available. For other LOTAAS pulsars, we derive their 0.3–500 GeV flux upper limits. In order to compare the LOTAAS pulsars with the known γ-ray pulsars, we also derive the 0.3–500 GeV γ-ray fluxes for 112 of the latter contained in the Fermi LAT fourth source catalog. Based on the properties of the γ-ray pulsars, we derive upper limits on the spin-down luminosities of the LOTAAS pulsars. The upper limits are not very constraining but help suggest that most of the LOTAAS pulsars probably have < 1033 erg s−1 spin-down luminosities and are not expected to be detectable with Fermi LAT.
Research on the HIP 18856 binary system
Authors: Efremova Polina , Mitrofanova Arina , Dyachenko Vladimir , Beskakotov Anatoly , Maksimov Alexander , Rastegaev Denis , Balega Yury , Komarinsky Sergey
Published: April 2021

The results of a study on the binary HIP 18856 and construction of its orbit are presented. New observational data were obtained at the BTA of SAO RAS in 2007-2019. Earlier, Cvetković et al. constructed the orbit for this system. However, it is based on six measurements, which cover a small part of the orbit. The positional parameters of the ESA astrometric satellite Hipparcos published speckle interferometric data (Mason et al., Balega et al., Horch et al.) and new ones were used in this study. Based on the new orbital parameters, the mass sum was calculated and the physical parameters of the components were found. The obtained orbital and fundamental parameters were compared with the data from the study by Cvetković et al.. The comparison shows that the new orbital solution is better than the old one, since it fits new observational data accurately. Also based on a qualitative evaluation performed by Worley & Heintz, the new orbit was classified as “reliable”, which means data cover more than half of the orbit with sufficient quantities of residuals of measurements.
Automatic detection and correction algorithms for magnetic saturation in the SMFT/HSOS longitudinal magnetograms
Authors: Xu Hai-Qing , Liu Suo , Su Jiang-Tao , Deng Yuan-Yong , Plotnikov Andrei , Bai Xian-Yong , Chen Jie , Yang Xiao , Guo Jing-Jing , Wang Xiao-Fan , Song Yong-Liang
Published: April 2021

A longitudinal magnetic field often suffers the saturation effect in a strong magnetic field region when the measurement is performed at a single-wavelength point and linear calibration is adopted. In this study, we develop a method that can judge the threshold of saturation in Stokes V/I observed by the Solar Magnetic Field Telescope (SMFT) and correct it automatically. The procedure is to first perform the second-order polynomial fit to the Stokes V/I vs. I/Im
(Im
is the maximum value of Stokes I) curve to estimate the threshold of saturation, then reconstruct Stokes V/I in a strong field region to correct for saturation. The algorithm is demonstrated to be effective by comparing with the magnetograms obtained by the Helioseismic and Magnetic Imager (HMI). The accuracy rate of detection and correction for saturation is ∼99.4% and ∼88% respectively among 175 active regions. The advantages and disadvantages of the algorithm are discussed.
On the torque exerted by a warped, magnetically threaded accretion disk
Authors: Liu Chang , Li Xiang-Dong
Published: April 2021

Most astrophysical accretion disks are likely to be warped. In X-ray binaries, the spin evolution of an accreting neutron star is critically dependent on the interaction between the neutron star magnetic field and the accretion disk. There have been extensive investigations on the accretion torque exerted by a coplanar disk that is magnetically threaded by the magnetic field lines from the neutron stars, but relevant works on warped/tilted accretion disks are still lacking. In this paper we develop a simplified two-component model, in which the disk is comprised of an inner coplanar part and an outer, tilted part. Based on standard assumption on the formation and evolution of the toroidal magnetic field component, we derive the dimensionless torque and show that a warped/titled disk is more likely to spin up the neutron star compared with a coplanar disk. We also discuss the possible influence of various initial parameters on the torque.
Chaos-induced resistivity in different magnetic configurations
Authors: Wang Zhen , Wu De-Jin , Chen Ling , Hao Yu-Fei
Published: April 2021

It is widely believed that magnetic reconnection plays an important role in various eruptive phenomena of space and astrophysical plasmas. The mechanism of anomalous resistivity, however, has been an open and unsolved problem. The chaos-induced resistivity proposed by Yoshida et al. is one of possible mechanisms for anomalous resistivity. By use of the test particle simulation, the present work studies the chaos-induced resistivity for different configurations of reconnection magnetic fields and its distribution in different chaos regions of reconnection current sheets. The results show that the chaos-induced resistivity can be 6 – 7 orders of magnitude higher than the classical Spitzer resistivity in the X-type chaos regions and 5 orders of magnitude in the O-type chaos regions. Moreover, in the X-type chaos regions the chaos-induced resistivity of the magnetized case is higher by a factor of 2 to 3 times than that of the unmagnetized case, but in the O-type chaos regions the chaos-induced resistivity of the magnetized case is close to or lower than that of the unmagnetized case. The present work is helpful to the understanding of the dynamics of reconnection current sheets, especially of the generation mechanism of the anomalous resistivity of collisionless reconnection regions.
A Brief Analysis of Intelligent Voice Technology for China’s Mainstream Media Content Production and Distribution Implications —— Take the Application of IFLYTEK Series Products in Mainstream Media as an Example
Authors: Song B X
Published: April 2021

Intelligent speech technology including speech recognition (ASR) and speech synthesis technology (TTS), it is in China’s mainstream media plays an important role in technological innovation, appropriate use of this technology can improve the efficiency of the mainstream media content production and distribution of precision, while fully give play to the role of the mainstream media propaganda, to give the mainstream media fresh vitality, so as to promote China’s mainstream media communication effect. IFLYTEK, as a leader in the field of intelligent voice technology, has close cooperative relations with many mainstream media. By analyzing the application of IFLYTEK series products in mainstream media from the perspective of technology, we can better understand the impact of intelligent voice technology on the production and distribution of mainstream media content in China.
Research on Modified Wavelet Threshold Denoising Algorithm Based around SEMG Signal
Authors: Wang Meng , Deng Keyong , Gao Leilei , Wang Hao , Li Zhijun
Published: April 2021

The surface electromyography (SEMG) signal of the lower limbs is collected by attaching electrodes to the surface of the muscles of the lower limbs, so it is non-invasive and simple to operate. Selected the threshold and the threshold function is very important when used the wavelet threshold denoising method to process some non-linear SEMG signals. But the traditional threshold is a fixed value, which is not conducive to the improvement of the denoising effect. Present paper discusses the previous wave threshold denoising means aiming at their shortcomings, to this end, an improved threshold method is proposed in present paper, which can change the threshold with the number of decomposition layers. In the meantime, the shortcomings of the previous threshold functions can be overcome by the modified threshold function. The SNR and MSE is selected as the parameters to evaluate the denoising performance and comparing the modified wavelet threshold denoising arithmetic with the traditional threshold arithmetic, the experiment results indicated that the denoising impact of the modified arithmetic is better than the previous arithmetic and it has certain practical value.