bluuebunny/crossref_metadata_2025 huggingface dataset:
A rhodamine-based fluorescent probe for Fe3+: synthesis, theoretical calculation and bioimaging application
Authors: Cheng Zhao , Zheng Lei , Xu Hao , Pang Long , He Hao
Published: April 2019

A rhodamine-based fluorescent probe J1 with low cytotoxicity and characteristic fluorescence imaging of intracellular Fe3+ in living cells L929.
The development of tertiary amine cationic lipids for safe and efficient siRNA delivery
Authors: Lin Ziming , Bao Moxyel , Yu Zexuan , Xue Lingjing , Ju Caoyun , Zhang Can
Published: April 2019

Tertiary amine-derived cationic lipid serves as the primary lipid of cationic liposomes, which can balance the effectiveness and safety of siRNA vectors.
Light-driven catalytic hydrogenation of carbon dioxide at low-pressure by a trinuclear iridium polyhydride complex
Authors: Shitaya Shoji , Nomura Kotohiro , Inagaki Akiko
Published: April 2019

Under irradiation conditions, low-pressure and room-temperature hydrogenation of carbon dioxide (CO2) has been achieved using a trinuclear iridium hexahydride complex 1.
Stackable molecular chairs
Authors: Xie Han , Zhiquan Lei , Pavlović Radoslav Z. , Gallucci Judith , Badjić Jovica D.
Published: April 2019

Molecular chairs, carrying three amino acids or peptides, stack in an antiparallel fashion to give hexavalent assemblies for bottom-up construction of novel soft materials and therapeutics.
Simultaneous stereocomplex cocrystallization from coexisting two types of stereocomplexationable poly(lactide) systems
Authors: Tsuji Hideto , Kikkawa Koudai , Ozawa Ryota , Arakawa Yuki
Published: April 2019

Simultaneous stereocomplex cocrystallization from two types of stereocomplexationable poly(lactide) systems, four-armed stereodiblock poly(lactide) and one-armed poly(l-lactide) and poly(d-lactide), was investigated.
Coordination polymers based on pyrazole-4-carboxaldehyde-containing Cu3N6 metallacycles as building units
Authors: Kreiger David I. , Mathivathanan Logesh , Raptis Raphael G.
Published: April 2019

Two novel topologies were obtained by self-assembly of 4-formylpyrazolate-Cu3 SBUs in the absence of competing terminal ligands.
Effect of Li concentration-dependent material properties on diffusion induced stresses of a Sn anode
Authors: Hong Chung Su , Qaiser Nadeem , Nam Hyeon Gyun , Han Seung Min
Published: April 2019

Concentration-dependent material properties corresponding to lithiated phases of Sn anode are important factors to predict the stress generation of Sn anode during lithiation.
Selective enhanced sampling in dihedral energy facilitates overcoming the dihedral energy increase in protein folding and accelerates the searching for protein native structure
Authors: Shao Qiang , Yang Lijiang , Zhu Weiliang
Published: April 2019

A dihedral-energy-based selective enhanced sampling method (D-SITSMD) is presented with improved capabilities for searching a protein's natively folded structure and for providing the underlying folding pathway.
Tunable photoluminescence from interconnected graphene network with potential to enhance the efficiency of a hybrid Si nanowire solar cell
Authors: Mihalache Iuliana , Purcarea Alexandra , Vasile Eugeniu , Pachiu Cristina , Eremia Sandra A. V. , Radoi Antonio , Kusko Mihaela
Published: April 2019

Interconnected graphene network (IGN) with surface trap state tunable photoluminescence improved the performance of hybrid solar cell via heterojunction and surface passivation effects.
Effect of electron correlation in the decomposition of core level binding energy shifts into initial and final state contributions
Authors: Figueras Marc , Sousa Carmen , Illas Francesc
Published: April 2019

The influence of electron correlation into the decomposition of core level binding energy shifts, measured by X-ray photoelectron spectroscopy (XPS), into initial and final effects is analysed for a series of molecules where these effects are noticeable.
Small molecule activation by boron-containing heterocycles
Authors: Su Yuanting , Kinjo Rei
Published: April 2019

This review focuses on boron-containing heterocycles enabling the activation of σ- and π-bonds in small molecules.
Prussian blue derived Fe2N for efficiently improving the photocatalytic hydrogen evolution activity of g-C3N4 nanosheets
Authors: Qi Weiliang , Liu Siqi , Li Fei , Jiang Heng , Cheng Zhixing , Zhao Shanlin , Yang Minghui
Published: April 2019

Prussian blue derived Fe2N nanoparticles to efficiently improve the photocatalytic H2-generation rate over pure g-C3N4 nanosheets.
Insight into the branched alcohol formation mechanism on K–ZnCr catalysts from syngas
Authors: Wu Yingquan , Gong Nana , Zhang Min , Zhang Wei , Zhang Tao , Zhang Junfeng , Wang Liyan , Xie Hongjuan , Tan Yisheng
Published: April 2019

The first C–C bond formation is from the reaction of CO and CHO (formyl) on the K–ZnCr catalysts.
4-Halo-1,2,3-triazolylidenes: stable carbenes featuring halogen bonding
Authors: Xu Xingyu , Zhang Zengyu , Huang Shiqing , Cao Lei , Liu Wei , Yan Xiaoyu
Published: April 2019

Synthesis and coordination of 4-halo-1,2,3-triazolylidenes have been developed.
Solvent system for effective near-term production of hydroxymethylfurfural (HMF) with potential for long-term process improvement
Authors: Motagamwala Ali Hussain , Huang Kefeng , Maravelias Christos T. , Dumesic James A.
Published: April 2019

A process that upgrades biomass-derived sugars to 5-hydroxymethylfurfural (HMF), a value-added platform molecule, is presented. The proposed process is ideally suited for integration with the current HFCS process and has the potential for long-term process improvement.
RF-GlutarySite: a random forest based predictor for glutarylation sites
Authors: AL-barakati Hussam J. , Saigo Hiroto , Newman Robert H. , KC Dukka B.
Published: April 2019

Glutarylation, which is a newly identified posttranslational modification that occurs on lysine residues, has recently emerged as an important regulator of several metabolic and mitochondrial processes. Here, we describe the development of RF-GlutarySite, a random forest-based predictor designed to predict glutarylation sites based on protein primary amino acid sequence.
Ratiometric theranostic nanoprobe for pH imaging-guided photodynamic therapy
Authors: Cheng Hong , Fan Gui-Ling , Fan Jing-Hao , Zhao Lin-Ping , Zheng Rong-Rong , Yu Xi-Yong , Li Shi-Ying
Published: April 2019

A FRET-based theranostic nanoprobe is fabricated for ratiometric pH imaging-guided photodynamic therapy against tumor cells.
Direct laser writing of flexible planar supercapacitors based on GO and black phosphorus quantum dot nanocomposites
Authors: Fu Xiu-Yan , Chen Zhao-Di , Zhang Yong-Lai , Han Dong-Dong , Ma Jia-Nan , Wang Wei , Zhang Zi-Rui , Xia Hong , Sun Hong-Bo
Published: April 2019

The research interest in wearable electronics has continuously stimulated the development of flexible energy storage systems with high performance and robustness.
Field-induced slow relaxation of magnetization in the S = 3/2 octahedral complexes trans-[Co{(OPPh2)(EPPh2)N}2(dmf)2], E = S, Se: effects of Co–Se vs. Co–S coordination
Authors: Ferentinos Eleftherios , Xu Meixing , Grigoropoulos Alexios , Bratsos Ioannis , Raptopoulou Catherine P. , Psycharis Vassilis , Jiang Shang-Da , Kyritsis Panayotis
Published: April 2019

Magnetometry studies on octahedral trans-[Co{(OPPh2)(EPPh2)N}2(dmf)2], E = S, Se, complexes.
One-dimensional facile growth of MAPbI3 perovskite micro-rods
Authors: Mishra Arti , Ahmad Zubair , Touati Farid , Shakoor R. A. , Nazeeruddin Mohammad Khaja
Published: April 2019

One-dimensional microrods (4–5 mm) of PbI2 and CH3NH3PbI3 (MAPbI3) with unique structural and morphological properties have been grown at room temperature.
Impact of asphalt aging temperature on chemo-mechanics
Authors: L. D. Poulikakos , Falchetto A. Cannone , D. Wang , L. Porot , B. Hofko
Published: April 2019

A link between the chemistry and rheology of bituminous binders with a focus on short-term aging temperature is proposed. This link is made using a rheological aging index (RAI), the crossover temperature and a chemical aging index (CAI).
The effect of graphene-nanoplatelets on gelation and structural integrity of a polyvinyltrimethoxysilane-based aerogel
Authors: Karamikamkar Solmaz , Abidli Abdelnasser , Behzadfar Ehsan , Rezaei Sasan , Naguib Hani E. , Park Chul B.
Published: April 2019

Aerogels suffer greatly from poor mechanical properties resulting from their particulate structure.
Photoredox Ni-catalyzed peptide C(sp2)–O cross-coupling: from intermolecular reactions to side chain-to-tail macrocyclization
Authors: Lee Hyelee , Boyer Nicolas C. , Deng Qiaolin , Kim Hai-Young , Sawyer Tomi K. , Sciammetta Nunzio
Published: April 2019

Ni/photoredox (4DPAIPN) dual catalysis enabled challenging peptide C(sp2)–O coupling reactions.
Effects of droplet size and surfactants on anchoring in liquid crystal nanodroplets
Authors: Sumer Zeynep , Striolo Alberto
Published: April 2019

In an attempt to bridge the gap between computational and experimental studies, coarse-grained simulations are used to study nematic Liquid Crystal (LC) nanodroplets dispersed in water. A LC phase diagram is generated as a function of droplet size and temperature, and the effect of adding surfactants is quantified.
Subdiffraction nanofocusing of circularly polarized light with a plasmonic cavity lens
Authors: Luo Yunfei , Kong Weijie , Zhao Chengwei , Liu Kaipeng , Pu Mingbo , Wang Changtao , Luo Xiangang
Published: April 2019

Nanofocusing beyond the diffraction limit could be achieved by a plasmonic cavity lens under circularly polarized light illumination.
Intermediate-temperature sensors based on La0.5Ba0.5MnO3/nanoporous anodic aluminum oxide multilayered film thermistors
Authors: Nakajima Tomohiko , Hanawa Satomi , Tsuchiya Tetsuo
Published: April 2019

Perovskite La0.5Ba0.5MnO3 (LBMO) film thermistors for temperature monitoring over a wide range of intermediate temperatures (200–450 °C) were fabricated on thin Al-foil substrates with a nanoporous anodic aluminum oxide layer at the Al surface (AAO-Al).
Epoxyeicosatrienoic acid analog EET-B attenuates post-myocardial infarction remodeling in spontaneously hypertensive rats
Authors: Neckář Jan , Hye Khan Md. Abdul , Gross Garrett J. , Cyprová Michaela , Hrdlička Jaroslav , Kvasilová Alena , Falck John R. , Campbell William B. , Sedláková Lenka , Škutová Šárka , Olejníčková Veronika , Gregorovičová Martina , Sedmera David , Kolář František , Imig John D.
Published: April 2019

Epoxyeicosatrienoic acids (EETs) and their synthetic analogs have cardiovascular protective effects. Here, we investigated the action of a novel EET analog EET-B on the progression of post-myocardial infarction (MI) heart failure in spontaneously hypertensive rats (SHR). Adult male SHR were divided into vehicle- and EET-B (10 mg/kg/day; p.o., 9 weeks)-treated groups. After 2 weeks of treatment, rats were subjected to 30-min left coronary artery occlusion or sham operation. Systolic blood pressure (SBP) and echocardiography (ECHO) measurements were performed at the beginning of study, 4 days before, and 7 weeks after MI. At the end of the study, tissue samples were collected for histological and biochemical analyses. We demonstrated that EET-B treatment did not affect blood pressure and cardiac parameters in SHR prior to MI. Fractional shortening (FS) was decreased to 18.4 ± 1.0% in vehicle-treated MI rats compared with corresponding sham (30.6 ± 1.0%) 7 weeks following MI induction. In infarcted SHR hearts, EET-B treatment improved FS (23.7 ± 0.7%), markedly increased heme oxygenase-1 (HO-1) immunopositivity in cardiomyocytes and reduced cardiac inflammation and fibrosis (by 13 and 19%, respectively). In conclusion, these findings suggest that EET analog EET-B has beneficial therapeutic actions to reduce cardiac remodeling in SHR subjected to MI.
The CMB angular power spectrum via component separation: a study on Planck data
Authors: Umiltà C. , Cardoso J. F. , Benabed K. , Le Jeune M.
Published: April 2019

Aims. We investigate the extent to which foreground-cleaned cosmic microwave background (CMB) maps can be used to estimate cosmological parameters at small scales.

Methods. We use the SMICA method, a blind separation technique that works directly at the spectral level. In this work we focus on the small scales of the CMB angular power spectrum, which are chiefly affected by noise and extragalactic foregrounds, such as point sources. We adapt SMICA to use only cross-spectra between data maps, thus avoiding the noise bias. In this study, performed using both simulations and Planck 2015 data, we fit for extragalactic point sources by modelling them as shot noise of two independent populations.

Results. In simulations, we correctly recover the point-source emission law, and obtain a CMB angular power spectrum that has an average foreground residual of one fifth of the CMB power at ℓ ≥ 2200. With Planck data, the recovered point-source emission law corresponds to external estimates, with some offsets at the highest and lowest frequencies, possibly due to frequency decoherence of point sources. The CMB angular power spectrum residuals are consistent with what we find in simulations. The cosmological parameters obtained from the simulations and the data show offsets up to 1σ on average from their expected values. Biases on cosmological parameters in simulations represent the expected level of bias in Planck data.

Conclusions. The results on cosmological parameters depend on the detail of the foreground residual contamination in the spectrum, and therefore a tailored modelling of the likelihood foreground model is required.
The use of tools and approaches of system dynamics in the analysis of the efficiency of BIM implementation and its impact on the management and planning of investments in the construction sector
Authors: Hotový Martin
Published: April 2019

This paper presents the use of tools and approaches of system dynamics in the analysis of the efficiency of BIM tools implementation in relation to the management and planning of investments in the construction sector. The dynamic model based on the approach of system dynamics allows to simulate the impact rate (range) of BIM implementation in strategic investment decision-making in the construction sector. Based on the analysis, the key parameters critically affecting the large construction investment projects are determined. The proposed model is implemented as a submodel in the dynamic model designed for potential refinements in the strategic planning of the extent of investments into projects of civil infrastructure of the Czech Republic. The model allows to test different strategies in the virtual world before their implementation. The prediction of future developments based on the proposed model allows to streamline planning and decision-making processes.
Investigation of longitudinal reinforcement contribution in shear punching of reinforced concrete flat slabs without transverse reinforcement
Authors: Alekhin Vladimir , Budarin Alexander , Pletnev Maxim , Avdonina Liubov
Published: April 2019

The shear punching of the reinforced concrete slabs is a complex process occurring when considerable force is concentrated on the relatively small area of a column-slab connection. An incorrect assessment of load capacity of slab under the punching shear may lead to an accident. One of the most significant factors affecting the slab capacity is longitudinal reinforcement. In this article much attention is given to the analysis of the longitudinal rebar impact on the maximum loading capacity of reinforced concrete slabs without transverse reinforcement affected by punching shear force using the finite element method. The results obtained via the finite element simulation are compared with laboratory tests and manual calculations carried-out using various methods represented in different national building Codes of practice.
Interior Materials Combination and Perceived Indoor Air Quality
Authors: Juhasova Senitkova Ingrid
Published: April 2019

The materials used in the buildings, either as surface structural materials or as furnishings, are mostly the sources of indoor air pollution. Interior surfaces are generally accepted as the main source of indoor TVOCs emissions. The poor indoor microclimate quality can cause the sick building syndrome, as well as negatively affects the people activities and wellbeing. In recent years the needs of indoor air quality and building performance improvement have been increasing. The indoor materials impact on perceived indoor air quality for various surface interior materials and its combination was studied within this paper. Traditional and progressive materials comparison reveals new fact regarding the TVOCs concentration. The task of the study was to investigate the possibility using individual material surfaces sorption ability. The chemical analysis and sensory assessments identifies health adverse of indoor air pollutants (TVOCs). Also we can use knowledge about the targeted use of sorption effect already in the building design phase. The results demonstrate the various sorption abilities of various indoor materials as well as various sorption ability of the same indoor material in various combinations.
Analysis of Thermal Bridges in Loggias of Pre-Cast Concrete Apartment Buildings
Authors: Kalousek Lubor , Brzoň Roman , Fišarová Zuzana
Published: April 2019

The issue of complex regeneration of old pre-cast concrete apartment buildings is still a current task of everyday construction practice in the Czech Republic. When designing a new thermal insulation for the envelope of these buildings, we often encounter with critical assembly details. The correct solution of these details requires a detailed assessment in terms of the requirements of thermal protection of buildings. A correct assessment of these critical details is often very challenging and the ordinary designer is virtually unable to do it himself. This paper presents a practical and theoretical example of the design, solution and assessment of additional insulation of loggia loadbearing structures. Using the Ansys software platform, the critical details in 3D were designed and the influence of new thermal insulation on removal of the building defects was assessed. In conclusion, several proposals for possible rehabilitations and their expected efficiency were summarized.
Freundliche Distanzwesen
Authors: Höke Heike
Published: April 2019

Tiergestützte Therapien sprechen die uralte Verbindung des Menschen zu Tier und Natur an und eröffnen damit einen instinktiven und sofort abrufbaren Zugang mit großem therapeutischen Potenzial. Die Arbeit mit Tieren kann bei Menschen mit Autismus Kommunikationsstörungen, Ängste und Verhaltensauffälligkeiten deutlich verbessern. Lamas und Alpakas eignen sich durch ihr zurückhaltendes Wesen hervorragend für die Therapie autistischer, psychisch oder geistig beeinträchtigter Menschen.
Management der schweren idiopathischen Darmträgheit
Authors: Sailer Marco
Published: April 2019

Bei der schweren idiopathischen Obstipation (sog. „slow transit constipation“) handelt es sich um eine seltene Erkrankung, die fast ausschließlich bei Frauen in der 3. und 4. Lebensdekade angetroffen wird. Pathophysiologie und Ätiologie dieser Erkrankung sind nur z. T. bekannt, wobei es sich offensichtlich um ein multifaktorielles Geschehen handelt. Differenzialdiagnostisch müssen mechanische, medikamentöse, degenerative, metabolische, endokrinologische, neurologische und psychiatrische Ursachen der Obstipation ausgeschlossen werden. Hierzu ist eine umfangreiche interdisziplinäre Abklärung erforderlich. Zudem müssen gastrointestinale Funktionsanalysen gefordert werden, wobei der Bestimmung der Kolontransitzeit eine Schlüsselrolle zufällt. Wichtig ist weiterhin der Nachweis bzw. Ausschluss einer pangastrointestinalen Passagestörung, einer Beckenbodendysfunktion oder eines Colon irritabile. Die Initialtherapie der Slow Transit Constipation ist grundsätzlich konservativ. Nur bei gut dokumentiertem Therapieversagen sollte eine operative Behandlung erwogen werden. Als Standardverfahren hat sich die subtotale Kolektomie mit ileorektaler Anastomose durchgesetzt. Wesentliche Komplikationen der operativen Therapie sind Dünndarmileus, Inkontinenz und Persistenz oder Rezidiv von Obstipation und Abdominalschmerzen. Bei korrekter Patientenselektion kann mit einer Erfolgsquote von über 80% gerechnet werden.
Mirabegron, A Selective β3-Adrenoceptor Agonist Causes an Improvement in Erectile Dysfunction in Diabetic Rats
Authors: Yilmaz-Oral Didem , Kaya-Sezginer Ecem , Askin Dilan , Hamurtekin Yesim , Gur Serap
Published: April 2019

Aim To investigate the possible beneficial effect of mirabegron [a selective β3-adrenoceptor (AR) agonist] treatment on erectile dysfunction (ED) in streptozotocin-induced diabetic rats.

Methods Sprague-Dawley rats (n=20) were divided into two groups: control group and streptozotocin-induced diabetic group. In vivo erectile responses were evaluated after intracavernosal injection of mirabegron (0.4 mg/kg) in rats. The relaxation responses to electrical field stimulation (EFS, 10 Hz), sodium nitroprusside (SNP, 10 nM) and sildenafil (1 μM) of corpus cavernosum (CC) strips were examined after the incubation with mirabegron (10 μM). β3-ARs expression and localization were determined by Western blot and immunohistochemical analyses in CC tissue.

Results In vivo erectile responses of diabetic rats [intracavernasal pressure (ICP) / mean arterial pressure, 0.17±0.01] were decreased, which were restored after administration of mirabegron (0.75±0.01, P<0.001). The basal ICP (7.1±0.6 mmHg) in diabetic rats was markedly increased after mirabegron (36.1 ±5.4 mmHg, P<0.01). Mirabegron caused markedly relaxation in diabetic rat CC after phenylephrine precontraction. The relaxation responses to EFS and sildenafil were reduced in diabetic CC, which were increased in the presence of mirabegron. Mirabegron enhanced SNP-induced relaxation response in both groups. The expression and immunoreactivity of β3-ARs localized to CC smooth muscle were observed in control and diabetic rats.

Conclusions This is the first study to show that intracavernosal administration of mirabegron improved erectile function and neurogenic relaxation of CC in diabetic rats. These results may be supported by further studies using combinations of mirabegron and phosphodiesterase type 5 (PDE5) inhibitors for the treatment of diabetic ED, especially in patients who do not respond to PDE5 inhibitor therapy.
Gar nicht vegetarisch …
Authors: Bierbach Elvira
Published: April 2019

Heparin, Hyaluron und Co.: Obwohl sie auch synthetisch produziert werden könnten, werden viele Wirk- und Hilfsstoffe aus tierischen Materialien gewonnen. Der Grund sind die niedrigeren Kosten. Die Tiere, die als Quelle für die benötigten Substanzen dienen, werden in der Regel unter den Bedingungen der Massentierhaltung gezüchtet, gehalten und konsumiert. Verbrauchern, aber auch Verordnenden, ist oftmals nicht bewusst, dass ein Medikament oder Nahrungsergänzungsmittel tierische Substanzen (aus der Massentierhaltung) enthält.
Synthesis of Majusculamides A and B
Authors: Nakajima Daisuke , Sueyoshi Kosuke , Orihara Kensuke , Teruya Toshiaki , Yokoshima Satoshi
Published: April 2019

The synthesis of two marine lipodipeptides, majusculamides A and B, is described. The key feature of this synthesis is the stereoselective construction of an α-methyl-β-keto-carboxamide moiety.
Platelet Counts in Uncomplicated Pregnancies at Term
Authors: Riera Gregorio , Galindo Megan , Turrentine Mark
Published: April 2019

Objective This study aimed to evaluate platelet counts at delivery in uncomplicated pregnancies between 37 and 41 weeks of gestation.

Study Design Platelet counts in women 16 to 45 years of age from August 1, 2011, through May 15, 2018, with a singleton pregnancy that delivered from 370/7 to 416/7 weeks of gestation. Women with pregnancy-related complications, preexisting disorders, or on medications that could affect platelet counts were excluded.

Results A total of 18,526 women had uncomplicated pregnancies with mean platelet count from 370/7 to 416/7 weeks of gestation of 220 × 109/L. The lower limit 95th percentile (2.5% quantile) was 120 × 109/L. Platelet counts decreased weekly from 37 to 41 weeks of gestation, becoming significant at 39 weeks of gestation and beyond, compared with 37 weeks (p < 0.01). Mean platelet counts: 225 × 109/L at 37 weeks, 223 × 109/L at 38 weeks, 219 × 109/L at 39 weeks, 218 × 109/L at 40 weeks, and 216 × 109/L at 41 weeks of gestation. Platelet counts of less than 150 × 109/L occurred in 9.7%.

Conclusion Platelet counts in uncomplicated pregnancies decrease weekly from 37 to 41 weeks of gestation. This will be important to consider when serial platelet values are monitored for other indications.
How Can Pelvic MRI with Diffusion-Weighted Imaging Help My Pregnant Patient?
Authors: Horowitz Jeanne M. , Hotalen Irene M. , Miller Emily S. , Barber Emma L. , Shahabi Shohreh , Miller Frank H.
Published: April 2019

The purpose of this review is to explain how diffusion-weighted imaging (DWI) is used during magnetic resonance imaging (MRI) exams in pregnant patients for specific maternal indications, including evaluation of acute pelvic pain, adnexal masses, cancer diagnosis and staging, and morbidly adherent placenta. While ultrasound is often the appropriate initial imaging for evaluating a pregnant patient, MRI can be helpful when a pelvic ultrasound is indeterminate. MRI has advantages in that it does not use ionizing radiation and has shown no known deleterious effects to the fetus. The use of gadolinium-based contrast is controversial during pregnancy. DWI is a functional sequence performed during an MRI exam, which is valuable in the absence of gadolinium contrast, and can increase the visibility of inflammation, abscesses, and tumors. Case examples will be presented to demonstrate the utility and added value of DWI over conventional anatomic T1- and T2-weighted imaging in diagnosis of maternal disease in the pregnant patient's pelvis.
The characteristic analysis of the built-in vector atomic magnetometer in a nuclear magnetic resonance oscillator
Authors: Jiang Qiyuan , Li Jiajia , Wang Zhiguo , Zhang Yi , Luo Hui
Published: April 2019

We analyze the amplitude-frequency, phase-frequency, signal amplification, linear range, and vector characteristics of the built-in vector atomic magnetometer operating at extreme off-resonance condition in a nuclear magnetic resonance oscillator, which makes possible its performance improvement by a balanced strategy in optimizing the parameters based on the proposed model. The experiment validates our prediction of the amplitude-frequency characteristic, and the numerical simulation indicates that the applied carrier field with following demodulation procedure holds the potential to give one order of magnitude, which is experimentally-validated to have at least twice, signal enhancement and enable the vector characteristic, where a large longitudinal static field and an appropriate transverse relaxation time are preferred to have optimized characteristics depending on different applications.
Oversized coaxial relativistic extended interaction oscillator with gigawatt-level output at Ka-band
Authors: Li Shifeng , Duan Zhaoyun , Huang Hua , Chen Zhaofu , Liu Zhenbang , He Hu , Wang Zhanliang , Gong Yubing
Published: April 2019

In this paper, an oversized coaxial relativistic extended interaction oscillator (OCREIO) with gigawatt-level output at the Ka-band is proposed. We adopt a four-gap buncher cavity and a three-gap output cavity to increase the power capability and improve the electronic efficiency of the OCREIO. The beam-loading conductance for each mode existing in the buncher cavity is derived based on a small-signal theory. The beam-wave interaction and power capability for the 2π/3 and π modes exciting in the buncher cavity are analyzed. The operation mode 2π/3 is chosen by considering the beam-loading conductance and power capability. In addition, an improved method is proposed to mitigate the electric field intensity of the buncher cavity so as to moderate velocity modulation. The weak velocity modulation offers enough distance to make density modulation, thereby obtaining a relatively high fundamental harmonic current amplitude. Our study on the device performance of the proposed OCREIO, using the particle-in-cell simulation code CHIPIC, predicts an output power of 922.7 MW and a high electronic efficiency of 32.9% at 30.5 GHz, as well as the relatively less time of frequency-lock of self-oscillation <20 ns. The simulated results of the proposed OCREIO motivate us to practically develop the device in the near future.
Numerical investigation of dynamics and gas pressure effects in a nanosecond capillary sliding discharge
Authors: Timshina M. , Eliseev S. , Kalinin N. , Letunovskaya M. , Burtsev V.
Published: April 2019

The paper presents the results of a numerical investigation of the dynamics of a sliding discharge in a capillary with spatial dimensions similar to those typically used in X-ray sources based on fast capillary discharges. The discharge is created in argon at pressure p = 9 Torr by applying a voltage pulse of negative polarity with an amplitude of 5 kV, a rise time of 5 ns, and a duration of 20 ns. Obtained distributions of main discharge parameters reproduce basic characteristics of a sliding discharge and reveal the mechanism of discharge propagation. The electric field in the front of the discharge is defined by a negative space charge, which at a given moment during discharge propagation is localized in a narrow region along the dielectric surface. For the considered case, discharge propagation is accompanied by full charging of the dielectric surface. The influence of gas pressure on discharge is investigated within range p = 2–25 Torr. Extrema in dependencies of total discharge time and front velocity on gas pressure are obtained in simulations and analyzed.
Asymmetric and endogenous magnetic reconnection processes in quasi-collisionless plasmas
Authors: Coppi B. , Basu B.
Published: April 2019

We define an endogenous magnetic reconnection process as the one having a driving factor that lies within the region where a drastic change in magnetic field topology occurs. A process of this kind is shown to take place when an electron temperature gradient is present in a plasma column and when, referring to quasi-collisionless regimes, the evolving electron temperature fluctuations are anisotropic. A two-fluid theory, for weakly collisional plasma regimes and confinement configurations which have sheared magnetic fields, is formulated, and two classes of reconnecting modes are identified. The localized class of modes is characterized by a transverse reconnecting magnetic field B̃x of odd parity, as a function of the radial variable (across the reconnection layer). The width of this remains significant even when large macroscopic distances, such as those of interest to space and astrophysics, are considered. The relevant reconnection can be referred to as antisymmetric. In fact, the (additional and realistic) presence of a finite current density gradient leads to finding modes with mixed B̃x parity which are no longer localized within the reconnection layer. Then, the resulting magnetic islands are not symmetric. In view of the fact that there are plasmas in the Universe with considerable electron thermal energy contents, the features of the novel reconnecting modes can be relied upon in order to produce generation of magnetic fields or conversion of magnetic energy into particle energy (through a sequence of mode-particle resonances).
Effects of charge-density-wave phase transition on electrical transport and Raman spectra in 2H-tantalum disulfide
Authors: Zhang Kai , Cao Zi-Yu , Chen Xiao-Jia
Published: April 2019

Measurements of electrical transport and Raman spectroscopy are performed on 2H-TaS2 to study the formation and the character of the charge density wave. The entry of the charge-density-wave state below the lock-in temperature is detected by the sudden change of the resistivity slope with temperature, the sharp rise of the magneto-resistivity, and the significant change in the Hall coefficient. Meanwhile, the frequency of the two-phonon mode decreases with decreasing temperature. When approaching the lock-in temperature, the formation of the charge density wave is also evidenced by the disappearance of the two-phonon mode. In the charge density wave state, the newly born charge-density-wave modes in the E2g- and A1g-symmetries exhibit a blue-shift with decreasing temperature. These results suggest that the combined techniques of electrical transport measurement and Raman spectroscopy are powerful in studying the charge-density-wave order in materials with strong electron-phonon coupling.
Passive feedback control of transonic buffet flow
Authors: Gao Chuanqiang , Zhang Weiwei , Li Xintao
Published: April 2019

The activated structural degree of freedom often causes undesirable large-amplitude structural vibrations in unstable flows, such as the frequency lock-in phenomenon in the transonic buffet flow. The underlying mechanism is the instability characteristic of the system that becomes more complex, namely, further instability on the structural mode because of the effect of fluid-structure interaction. In this paper, we study the feasibility of improving the stability of the transonic buffet flow by activating the structural degree of freedom based on numerical simulations and a low-dimensional model. Results reveal that the activated structural degree of freedom can stabilize the buffet flow, eliminating the source of the oscillatory flow. The essence of this strategy is to efficiently utilize the coupling effect between the structural mode and the fluid mode to improve the stability of the fluid mode by properly decreasing the stability margin of the structural mode. From another perspective, this approach is a new passive-feedback flow control strategy, which does not change the shape of the subject compared with the classical passive control and which does not need extra actuation and power compared with the active control.
Numerical study of wake and aerodynamic forces on two tandem circular cylinders at Re = 103
Authors: Zhou Qiang , Alam Md. Mahbub , Cao Shuyang , Liao Haili , Li Mingshui
Published: April 2019

Three-dimensional large eddy simulations were carried out to investigate the flow around two tandem circular cylinders at a subcritical Reynolds number of Re = 103. The cylinder center-to-center spacing ratio L/D is varied from 1.25 to 6, where D is the cylinder diameter. In order to enhance the understanding of flow physics around two circular cylinders, particular attention is devoted to fluctuating forces, shear-layer reattachment, flow separation, wake recirculation, Strouhal number (St), and phase lag (ϕ) between the fluctuating lift of the two cylinders. The flow structure around the cylinders is highly sensitive to L/D. A change in L/D thus leads to overshoot flow (L/D ≤ 1.25), reattachment flow (1.5 ≤ L/D ≤ 3.5), and coshedding flow (L/D ≥ 4). The boundaries are characterized by drastic changes in the flow structure and a discontinuous drop/rise in St and forces. The St drops at the boundary between overshoot and reattachment flow regimes and jumps at the boundary between reattachment and coshedding flow regimes, while fluctuating forces and ϕ both jump at both boundaries. The flow separation on the downstream cylinder is much delayed (122°–128°) in the reattachment flow regime compared to that on the single cylinder (95°) or upstream cylinder (92°–95.5°). The fluctuating pressure on the entire surface of either cylinder is low for the overshoot flow because the two cylinders are enclosed by the upstream-cylinder-generated shear layers having the longest wake recirculation. The ϕ is almost zero in the overshoot flow. With increasing L/D, ϕ linearly increases in the reattachment and coshedding regimes with different gradients, larger in the latter regime than in the former, by nearly twice.
A terahertz signal propagation model in hypersonic plasma sheath with different flight speed
Authors: Tang Rongxin , Mao Mingyang , Yuan Kai , Wang Yuhao , Deng Xiaohua
Published: April 2019

A hypersonic plasma sheath could shield communication signals, which results in the so-called “blackout.” Hypersonic flights in near space used to suffer from the “blackout.” Terahertz (THz) communication is considered to be a potential solution to the blackout problem. On the other hand, it is still not clear that how the complex flight conditions impact the THz communication channel conditions in the plasma sheath. The relation between the occurrence of communication blackout and the flight conditions is unclear either. In the present study, the relation between the THz signal attenuation in plasma sheaths and the hypersonic flight speed was investigated using the numerical hypersonic hydrodynamic model. According to this study, the thickness of the plasma sheath decreases with the increasing flight speed. The electron density and the electron collision frequency increase with the flight speed. As a result, the THz signal attenuation increases with the flight speed. In addition, a new estimation model, which is able to predict the THz signal attenuation in the plasma sheath for arbitrary flight speed, was developed on the basis of the numerical study. The estimation model, in which the hypersonic hydrodynamics is absent, could help to significantly reduce the time consumption in predicting the THz communication channel conditions as well as the occurrence of the blackout.
Quantifying the photoionization cross section of the hydroxyl radical
Authors: Harper O. J. , Hassenfratz M. , Loison J.-C. , Garcia G. A. , de Oliveira N. , Hrodmarsson H.R. , Pratt S. T. , Boyé-Péronne S. , Gans B.
Published: April 2019

The hydroxyl free radical, OH, is one of the most important radicals in atmospheric and interstellar chemistry, and its cation plays a role in the reactions leading to H2O formation. Knowledge of the photoionization efficiency of the OH radical is crucial to properly model the water photochemical cycle of atmospheres and astrophysical objects. Using a gas-phase radical source based on a single H-abstraction reaction combined with a photoelectron/photoion imaging coincidence spectrometer coupled with synchrotron radiation, we recorded the OH+ photoion yield over the 12.6–15 eV energy range, and we set it to an absolute cross section scale using an absolute point measurement performed at 13.8 eV: σOHion=9.0±2.7 Mb. The resulting cross section values differ by approximately a factor 2 from the recent measurement of Dodson et al. [J. Chem. Phys. 148, 184302 (2018)] performed with a different radical source, which is somewhat greater than the combined uncertainties of the measurements. This finding underlines the need for further investigations of this cross section.
Effects of negative ions on discharge characteristics of water plasma source for a miniature microwave discharge ion thruster
Authors: Nakamura Kengo , Koizumi Hiroyuki , Nakano Masakatsu , Takao Yoshinori
Published: April 2019

This work analyzes the discharge characteristics of water plasma for a miniature microwave discharge ion thruster via three-dimensional particle-in-cell simulations with Monte Carlo collisions. It incorporates the negative ions (H−, O−, and OH−) into the simulation code, aside from the three major positive ion species (H2O+, OH+, and H+), and investigates their effects on the discharge characteristics. On the one hand, the simulation results indicate that H2O+ is the dominant species and the negative ions have little effect on the positive ion density and transport. On the other hand, this study confirms the axial oscillation of the OH− negative ion density, in addition to azimuthal rotation, causing plasma instability with a periodic low-frequency anomalous diffusion. The azimuthal rotation is similar to the phenomena observed in other E × B devices, where the difference in spatial distributions of magnetized electrons and unmagnetized ions causes the local potential hump and the resultant instability. Moreover, the axial oscillation, not observed in the previous study considering only positive ions, is due to the generation of OH− by the charge transfer collision reaction between H2O and H−, and this oscillation frequency is double that of the azimuthal rotation. Both the azimuthal rotation and the axial oscillation result in the periodic double peaks of the potential time evolution. These fluctuations have an influence on electron transport across the magnetic field.
Subwavelength grating-based spiral metalens for tight focusing of laser light
Authors: Kotlyar Victor V. , Stafeev Sergey S. , Nalimov Anton G. , O'Faolain Liam
Published: April 2019

In this paper, we investigate a 16-sector spiral metalens fabricated on a thin film (130 nm) of amorphous silicon, consisting of a set of subwavelength binary diffractive gratings and with a numerical aperture that is close to unity. The metalens converts linearly polarized incident light into an azimuthally polarized optical vortex and focuses it at a distance approximately equal to the wavelength of the incident light, λ = 633 nm. Using a scanning near-field optical microscope, it is shown experimentally that the metalens forms an elliptical focal spot with diameters smaller than the diffraction limit: FWHMx = 0.32λ (±0.03λ) and FWHMy = 0.51λ (±0.03λ). The experimental results are close to those of a numerical simulation using the FDTD method, with FWHMx = 0.37λ and FWHMy = 0.49λ. The technological errors due to manufacturing were taken into account in the simulation. This is the smallest focal spot yet obtained with a metalens.
Stability of discrete-time delayed pathogen infection models with latently infected cells
Authors: Elaiw A. M. , Alshaikh M. A.
Published: April 2019

This paper studies the global stability of a class of discrete-time delayed pathogen infection models with both latently infected cells and actively infected cells. In the second model, the production and clearance rates of the cells and pathogens are given by general functions. Three discrete time delays are considered. The continuous-time models are discretized by using nonstandard finite difference scheme. The basic and global properties of the models are established. The global stability analysis of the equilibria is performed using Lyapunov method. The theoretical results are illustrated by numerical simulations.
Conditional sentences in the Old East Frisian Brokmonna Bref
Authors: Brennan Roland K.
Published: April 2019

This paper offers a descriptive account of conditional sentences in theBrokmonna Bref(Brookmen’s Charter), an Old East Frisian regional law text of the thirteenth century. The text shows peculiarities of compositional design, particularly the systematised employment of verb-initial conditional sentences, attested to a lesser degree in other East Frisian texts, and which a comparative perspective reveals as sporadic outside Old Frisian. The descriptive approach provides a suitable opportunity to revisit, from the syntactic side, questions of phraseological inheritance in the language of Old Frisian law. In presenting data, this research takes initial steps towards further study of Old Frisian syntax and its relationship to West Germanic structures.
Un nuovo testimone del volgarizzamento veneto dell’Esopus attribuito a Gualtiero Anglico
Authors: Beretta Andrea
Published: April 2019

Astratto

L’articolo intende dare conto del ritrovamento di un nuovo testimone del volgarizzamento veneto
dell’Esopus attribuito a Gualterus Anglicus, del quale era precedentemente noto un solo
codice (London, British Library, 38023), edito da Vittore Branca. Il manoscritto che qui si presenta (segnato Venezia, Biblioteca
Nazionale Marciana, It. Z 74 (4826)) reca anche il testo integrale della fonte latina e si configura dunque come un esemplare
notevolissimo nell’ambito della fortuna della favolistica esopica in Italia. L’analisi fornisce una descrizione il più accurata
possibile del codice e del suo corredo illustrativo, e illumina i rapporti dei due testimoni latino e veneto in esso compresi con
il resto delle rispettive tradizioni testuali. Particolarmente interessante risulta inoltre l’esame dell’aspetto linguistico del
testo veneto: la maggiore antichità del codice Marciano (trecentesco) rispetto al (quattrocentesco) Londinese consente infatti di
delineare con maggiore chiarezza le diverse componenti di base della lingua del volgarizzamento.
The Revolt of the Mice
Authors: Idema Wilt L.
Published: April 2019

The tale of the war of the mice against the cat has a history of several thousands of years. First known from ancient
Egypt, it was wide-spread in Classical antiquity, would remain popular in the Near East until modern times, and also was widely known in
Europe in medieval and early modern times in paintings, prints, songs, and mock-epics. In China the most popular tale on the antagonism of
mice and cats was the tale of their underworld court case. Starting from the first half of the nineteenth century, some versions of that
tale also include an account of the war between the two species. Only one stand-alone treatment of the theme is known from an edition of the
1920s. In Japan the theme of the war of the mice against the cats also makes its first appearance in print in the first half of the
nineteenth century. No direct foreign influence can be discerned in the emergence of this theme in either country.
Neurons regulate synaptic strength through homeostatic scaling of active zones
Authors: Cunningham Karen L. , Littleton J. Troy
Published: April 2019

How neurons stabilize their overall synaptic strength following conditions that alter synaptic morphology or function is a key question in neuronal homeostasis. In this issue, Goel et al. (2019. J. Cell Biol. https://doi.org/10.1083/jcb.201807165) find that neurons stabilize synaptic output despite disruptions in synapse size, active zone number, or postsynaptic function by controlling the delivery of active zone material and active zone size.
Statistical properties of hybrid estimators proposed for GEDI—NASA’s global ecosystem dynamics investigation
Authors: Patterson Paul L , Healey Sean P , Ståhl Göran , Saarela Svetlana , Holm Sören , Andersen Hans-Erik , Dubayah Ralph O , Duncanson Laura , Hancock Steven , Armston John , Kellner James R , Cohen Warren B , Yang Zhiqiang
Published: April 2019

NASA’s Global Ecosystem Dynamics Investigation (GEDI) mission will collect waveform lidar data at a dense sample of ∼25 m footprints along ground tracks paralleling the orbit of the International Space Station (ISS). GEDI’s primary science deliverable will be a 1 km grid of estimated mean aboveground biomass density (Mg ha−1), covering the latitudes overflown by ISS (51.6 °S to 51.6 °N). One option for using the sample of waveforms contained within an individual grid cell to produce an estimate for that cell is hybrid inference, which explicitly incorporates both sampling design and model parameter covariance into estimates of variance around the population mean. We explored statistical properties of hybrid estimators applied in the context of GEDI, using simulations calibrated with lidar and field data from six diverse sites across the United States. We found hybrid estimators of mean biomass to be unbiased and the corresponding estimators of variance appeared to be asymptotically unbiased, with under-estimation of variance by approximately 20% when data from only two clusters (footprint tracks) were available. In our study areas, sampling error contributed more to overall estimates of variance than variability due to the model, and it was the design-based component of the variance that was the source of the variance estimator bias at small sample sizes. These results highlight the importance of maximizing GEDI’s sample size in making precise biomass estimates. Given a set of assumptions discussed here, hybrid inference provides a viable framework for estimating biomass at the scale of a 1 km grid cell while formally accounting for both variability due to the model and sampling error.