bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of the effects of urea cycle amino acids on the expression of ALB and CEBPB in the human hepatocellular carcinoma cell line FLC-4
Authors: Fujimi Takahiko J. , Mezaki Yoshihiro , Masaki Takahiro , Tajima Ayasa , Nakamura Mariko , Yoshikawa Akira , Murai Noriyuki , Aizawa Mamoru , Kojima Soichi , Matsumoto Yoshihiro , Aizaki Hideki , Matsuura Tomokazu
Published: May 2020

Cell lines are powerful tools for research into liver function at the molecular level. However, they are generally unsuitable for rigorously assessing the effects of amino acid composition, because many lines require serum-containing medium for their maintenance. Here, we aimed to investigate the effects of ornithine and arginine, which are included in the characteristic metabolic process in hepatocyte, on a human hepatoma-derived cell line (FLC-4) that can be cultured in serum-free medium. FLC-4 cells were cultured under the following three conditions: + ornithine/ – arginine, – ornithine/ – arginine, and –ornithine/ + arginine. Albumin expression evaluated by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay and showed no obvious differences based on the presence of ornithine or arginine. However, the mRNA levels of two liver-enriched transcription factors (CEBPB and HNF1A), which are involved in regulating albumin expression, were significantly higher in cells grown in medium-containing arginine than that in cells grown in ornithine-containing medium. Western blotting showed that the levels both activating and inhibitory C/EBPβ isoforms were significantly increased in cells grown in arginine medium. Furthermore, we have found that depletion of both ornithine and arginine, the polyamine sources, in the medium did not cause polyamine deficiency. When ornithine and arginine were depleted, albumin production was significantly reduced at the mRNA level, CEBPB mRNA levels were increased, and the level of activating form of C/EBPβ was increased. The results of this study suggest that in hepatocyte, these two amino acids might have different functions, and because of which they elicit disparate cellular responses.
Asymmetry indicates more severe and active disease in Graves’ orbitopathy: results from a prospective cross-sectional multicentre study
Authors:   The European Group on Graves’ Orbitopathy, Perros P. , Žarković M. P. , Panagiotou G. C. , Azzolini C. , Ayvaz G. , Baldeschi L. , Bartalena L. , Boschi A. M. , Nardi M. , Brix T. H. , Covelli D. , Daumerie C. , Eckstein A. K. , Fichter N. , Ćirić S. , Hegedüs L. , Kahaly G. J. , Konuk O. , Lareida J. J. , Okosieme O. E. , Leo M. , Mathiopoulou L. , Clarke L. , Menconi F. , Morris D. S. , Orgiazzi J. , Pitz S. , Salvi M. , Muller I. , Knežević M. , Wiersinga W. M. , Currò N. , Dayan C. M. , Marcocci C. , Marinò M. , Möller L. , Pearce S. H. , Törüner F. , Bernard M.
Published: May 2020

Purpose

Patients with Graves’ orbitopathy can present with asymmetric disease. The aim of this study was to identify clinical characteristics that distinguish asymmetric from unilateral and symmetric Graves’ orbitopathy.

Methods

This was a multi-centre study of new referrals to 13 European Group on Graves’ Orbitopathy (EUGOGO) tertiary centres. New patients presenting over a 4 month period with a diagnosis of Graves’ orbitopathy were included. Patient demographics were collected and a clinical examination was performed based on a previously published protocol. Patients were categorized as having asymmetric, symmetric, and unilateral Graves’ orbitopathy. The distribution of clinical characteristics among the three groups was documented.

Results

The asymmetric group (n = 83), was older than the symmetric (n = 157) group [mean age 50.9 years (SD 13.9) vs 45.8 (SD 13.5), p = 0.019], had a lower female to male ratio than the symmetric and unilateral (n = 29) groups (1.6 vs 5.0 vs 8.7, p < 0.001), had more active disease than the symmetric and unilateral groups [mean linical Activity Score 3.0 (SD 1.6) vs 1.7 (SD 1.7), p < 0.001 vs 1.3 (SD 1.4), p < 0.001] and significantly more severe disease than the symmetric and unilateral groups, as measured by the Total Eye Score [mean 8.8 (SD 6.6) vs 5.3 (SD 4.4), p < 0.001, vs 2.7 (SD 2.1), p < 0.001].

Conclusion

Older age, lower female to male ratio, more severe, and more active disease cluster around asymmetric Graves’ orbitopathy. Asymmetry appears to be a marker of more severe and more active disease than other presentations. This simple clinical parameter present at first presentation to tertiary centres may be valuable to clinicians who manage such patients.
Pathogenicity of commercial entomopathogenic fungal strains on the avocado seed borer (ASB), Heilipus lauri (Coleoptera: Curculionidae) under laboratory conditions
Authors: Clavijo Andrea P. , Holguin Claudia M.
Published: May 2020

The avocado seed borer, (ASB)Heilipus lauriBoheman 1845 (Coleoptera: Curculionidae) is an official quarantine pest limiting avocado production and fruit exports from Colombia to pest-free countries. To provide alternatives to manage ASB, the objective of this study was to determine the potential use of commercial strains ofBeauveria bassianaandMetarhizium anisopliaeas biological control agents of this pest. Pathogenicity of the strains was evaluated by complete immersion of the insect in a spore solution (direct inoculation) or by insect contact with inoculated fruit (indirect inoculation). TheB. bassianastrain caused higher mortality (DF = 3, F = 25.7,P = 0.0002), showing an almost eight-fold increase, 55% and 79% mortality, for both concentrations used, 2.5 × 108spores/mL or 2.5 × 109spores/mL, respectively. Additionally, theB. bassianastrain showed shorter median survivorship using direct inoculation (15.8 to 8.7 days), a longer delay in the feeding initiation time (50 h), and a decrease in the fruit intake (Anti-feeding index above 50) after indirect inoculation. To our knowledge, this is the first report about the pathogenicity of a commercialB. bassianastrain against ASB in Colombia.
Durability of percutaneous transluminal angioplasty for failing hemodialysis vascular access, retrospective cohort study
Authors: Alhaizaey Abdullah , Alghamdi Musaad , Azazy Ahmed , Omran Walid , Hamdy Mohammed , Alhazmi Barrag , Karmotah Ahmed
Published: May 2020

ABSTRACT

Objective:

The arteriovenous fistula (AVF) is the preferred access type for hemodialysis, owing to its better patency rates and fewer complications. This study aimed to evaluate the outcome of percutaneous transluminal angioplasty in a failing arteriovenous fistula and arteriovenous graft in hemodialysis patients.

Methods:

Clinical data of patients who underwent percutaneous transluminal angioplasty in the vascular department of Aseer Central Hospitals, KSA, from January 2017 to May 2018 and with follow-up of >12 months were analyzed in retrospective cohort study.

Results:

Angioplasties were performed in 55 patients with fistulae, of which 18 patients had venous hypertension on dialysis and the remaining patients had weak or poor flow.

Conclusions:

Percutaneous transluminal angioplasty is an efficacious method for the correction of stenosis of arteriovenous fistulae for patients on hemodialysis, prolonging the patency of the fistula and enabling new interventions.

Highlights:
Non-Maxwellian rate coefficients for electron and ion collisions in Rydberg plasmas: implications for excitation and ionization
Authors: Vrinceanu Daniel , Onofrio Roberto , Sadeghpour H. R.
Published: May 2020

Scattering phenomena between charged particles and highly excited Rydberg atoms are of critical importance in many processes in plasma physics and astrophysics. While a Maxwell–Boltzmann (MB) energy distribution for the charged particles is often assumed for calculations of collisional rate coefficients, in this contribution we relax this assumption and use two different energy distributions, a bimodal MB distribution and a

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-distribution. Both variants share a high-energy tails occurring with higher probability than the corresponding MB distribution. The high-energy tail may significantly affect rate coefficients for various processes. We focus the analysis to specific situations by showing the dependence of the rate coefficients on the principal quantum number of hydrogen atoms in

$n$

-changing collisions with electrons in the excitation and ionization channels and in a temperature range relevant to the divertor region of a tokamak device. We finally discuss the implications for diagnostics of laboratory plasmas.
Heart rate variability in the course of chemotherapy and haematopoietic stem cell transplantation for peadiatric patients with haematological malignancies
Authors: Kobayashi Honami , Motoki Noriko , Yokota Saori , Kanai Ayako , Yamazaki Shoko , Utsumi Masafumi , Nakazawa Yozo
Published: May 2020

Background:

High-dose chemotherapy and haematopoietic stem cell transplantation are essential for patients with paediatric haematologic diseases, although cardiotoxicity remains a concern. Heart rate variability analysis can evaluate autonomic nervous function interactions with cardiac function.

Objective:

This study aimed to characterise heart rate variability differences between patients undergoing chemotherapy and controls, and the effects of haematopoietic stem cell transplantation on the autonomic nervous system in patients with haematological malignancies.

Methods:

Nineteen patients (11 male, median age: 11.6 years) who received conventional chemotherapy followed by transplantation and 19 non-transplant patients (10 male, median age: 11.5 years) receiving chemotherapy only between 2006 and 2018 for haematological malignancies were retrospectively enrolled. Data from 24-hour Holter monitoring were recorded after chemotherapy and before and after transplantation. Heart rate variability was analysed in patients and 32 matched normal controls.

Results:

There were significant differences between patients and normal controls in all heart rate variability analysis parameters apart from coefficient of variation of RR interval and standard deviation of the average normal RR interval for all 5-minute segments during sleeping. There was a significant difference in the cumulative anthracycline dose and heart rate variability during sleep between the non-transplant and pre-transplant groups. We observed no remarkable differences in time-domain analysis parameters between before and after transplantation, although the low-frequency component of power-spectrum analysis during awake hours was significantly decreased after transplantation.

Conclusion:

Conventional chemotherapy for paediatric haematologic diseases may be a risk factor for autonomic dysfunction. Further declines in heart rate variability after transplantation appear minor.
Compact high-efficiency pentahedron and quatrefoil shape antennas with enhanced gain for GSM1800, 3G, 4G-LTE energy harvesting applications
Authors: Polaiah Geriki , Krishnamoorthy K. , Kulkarni Muralidhar
Published: May 2020

In this paper, three compact, high-efficiency, gain enhanced antennas, and corresponding rectifiers have been proposed for GSM1800, 3G, and 4G-LTE energy harvesting applications. The inverted L-stub is placed on the ground plane of the monopole antenna to get the desired frequency band of GSM1800 MHz. The feed length variation method has been adopted for the slot antennas to obtain the required frequency of 3G and 4G-LTE cellular bands. The performance of antennas is analyzed with the inverted L-stub, feed length variation, and the reflector distance. The maximum gain achieved with the reflector positioned at a distance of λ/4 from the antenna backside is three times greater than the gain obtained without the reflector. The prototype antennas and rectifiers have been simulated, fabricated, measured various parameters, and compared with the simulation results. The antennas provide more than 82% radiation efficiency and an enhanced gain of greater than 5.6 dB. The peak efficiency of rectifiers of more than 30% has been achieved. The aforementioned three antennas are integrated with their corresponding rectifiers for operating at 1.8, 2.1, and 2.3 GHz frequencies. The proposed rectennas are formidably suitable for the reception of RF power from the cellular bands.
Unearthing the myths of global sustainable forest governance
Authors: Delabre Izabela , Boyd Emily , Brockhaus Maria , Carton Wim , Krause Torsten , Newell Peter , Wong Grace Y. , Zelli Fariborz
Published: May 2020

Non-technical summary

Despite efforts to address the global forest crisis, deforestation and degradation continue, so we need to urgently revisit possible solutions. A failure to halt the global forest crisis contributes to climate change and biodiversity loss and will continue to result in inequalities in access to, and benefits from, forest resources. In this paper, we unpack a series of powerful myths about forests and their management. By exposing and better understanding these myths and what makes them so persistent, we have the basis to make the social and political changes needed to better manage and protect forests globally.
Unprecedented Surface Chlorophyll Blooms in the Southeastern Arabian Sea During an Extreme Negative Indian Ocean Dipole
Authors: Thushara V. , Vinayachandran P. N.
Published: May 2020

Observations of ocean color in the southeastern Arabian Sea (SEAS) during the late boreal summer and fall of 2016 reveal the highest surface chlorophyll concentrations (>1.0 mg m−3) ever reported in the region in the past two decades of the satellite era. Anomalous chlorophyll blooms were triggered by two cold‐core eddies, along the periphery of the coastal upwelling zone. Observational evidence suggest that the eddy formation and propagation can be attributed to the local wind forcing and the remote effects originating around Sri Lanka and the southern tip of India (STI) during the extreme negative Indian Ocean Dipole (IOD) of 2016. The eddy‐induced anomalous shoaling of thermocline indicates strong upwelling of subsurface nutrients and chlorophyll and enhanced light availability for phytoplankton growth favoring the observed biological response. The study signifies the unprecedented impacts of extreme climatic events on oceanic chlorophyll and the need for better understanding of the associated biophysical interactions.
Tides on Other Earths: Implications for Exoplanet and Palaeo‐Tidal Simulations
Authors: Blackledge B. W. , Green J. A. M. , Barnes R. , Way M. J.
Published: May 2020

A key controller of a planet's rotational evolution, and hence habitability, is tidal dissipation, which on Earth is dominated by the ocean tides. Because exoplanet or deep‐time Earth topographies are unknown, a statistical ensemble is used to constrain possible tidal dissipation rates on an Earth‐like planet. A dedicated tidal model is used together with 120 random continental configurations to simulate Earth's semidiurnal lunar tide. The results show a possible ocean tidal dissipation range spanning 3 orders of magnitude, between 2.3 GWto 1.9 TW (1 TW=1012 W). When model resolution is considered, this compares well with theoretical limits derived for the energetics of Earth's present‐day deep ocean. Consequently, continents exert a fundamental control on tidal dissipation rates and we suggest that plate tectonics on a planet will induce a time‐varying dissipation analogous to Earth's. This will alter rotational periods over millions of years and further complicate the role of tides for planetary evolution.
Electron Acceleration by Magnetosheath Jet‐Driven Bow Waves
Authors: Liu Terry Z. , Hietala Heli , Angelopoulos Vassilis , Vainio Rami , Omelchenko Yuri
Published: May 2020

Magnetosheath jets are localized fast flows with enhanced dynamic pressure. When they supermagnetosonically compress the ambient magnetosheath plasma, a bow wave or shock can form ahead of them. Such a bow wave was recently observed to accelerate ions and possibly electrons. The ion acceleration process was previously analyzed, but the electron acceleration process remains largely unexplored. Here we use multipoint observations by Time History of Events and Macroscale during Substorms from three events to determine whether and how magnetosheath jet‐driven bow waves can accelerate electrons. We show that when suprathermal electrons in the ambient magnetosheath convect toward a bow wave, some electrons are shock‐drift accelerated and reflected toward the ambient magnetosheath and others continue moving downstream of the bow wave resulting in bidirectional motion. Our study indicates that magnetosheath jet‐driven bow waves can result in additional energization of suprathermal electrons in the magnetosheath. It implies that magnetosheath jets can increase the efficiency of electron acceleration at planetary bow shocks or other similar astrophysical environments.
New Middle–Late Permian Paleomagnetic and Geochronological Results From Inner Mongolia and their Paleogeographic Implications
Authors: Ren Qiang , Zhang Shihong , Gao Yangjun , Zhao Hanqing , Wu Huaichun , Yang Tianshui , Li Haiyan
Published: May 2020

A combined paleomagnetic and geochronological study was conducted on the red beds of the Zhesi Formation (ZSF) in the Xilinhot–Songliao Block (XSB) and the andesites and sandstones of the Qingfengshan Formation (QFF) in the North China Block (NCB). The ZSF tuffs and the QFF andesites were dated to 265.3 ± 1.8 Ma and 254.8–257.1 Ma, respectively, using the zircon U–Pb laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) method. A total of 246 paleomagnetic samples were subjected to stepwise thermal demagnetization. After removal of the low‐temperature viscous components acquired in the recent geomagnetic field, stable high‐temperature components (HTCs) were isolated from most samples. The HTC of the ZSF passed a fold test, and the HTC of the QFF passed both fold and reversal tests, indicating their primary origins. The corresponding paleomagnetic poles are 57.4°N/342.0°E (A95 = 4.3°) for the XSB at ~265 Ma and 54.3°N/20.2°E (A95 = 3.3°) for the NCB at ~255 Ma. Comparison of high‐quality Permian paleomagnetic poles of the XSB and NCB reveals a latitudinal convergence and relative rotation between them that led to a scissors‐like closure of the Solonker Ocean from west to east between ~265 and ~246 Ma, which controlled the mixing of the Cathaysian and Angara floras in space and time. The XSB and NCB moved rapidly northward between ~265 and ~255 Ma, which probably accelerated the end‐Guadalupian mass extinction in East Asia.
Ensemble Projection of Runoff in a Large‐Scale Basin: Modeling With a Global BMA Approach
Authors: Yan Ziqi , Zhou Zuhao , Liu Jiajia , Han Zhenyu , Gao Ge , Jiang Xintong
Published: May 2020

The projection of runoff in a large‐scale basin under climate change and human activities is crucial for the future management of water supplies. The impacts of climate change on runoff projections are associated with large uncertainties. In this study, using the optimization and selection of climate models, as well as an uncertainty analysis via the global Bayesian model averaging (BMA) approach, an ensemble projection framework was established to significantly improve the reliability of runoff projections in the future. The global BMA algorithm proposed in this study is an improvement on the BMA algorithm for large basins and is designed to reflect the differences among various models across the basin. In this algorithm, comprehensive BMA weights are obtained by considering the number (N) of stations in a basin. To verify the feasibility and improvement of this method, the runoff in 2050 and 2070 was projected with data from the Yellow River Basin, China. The runoff and its 90% confidence intervals at the six main stations in the Yellow River Basin were obtained. The increased evapotranspiration will exceed the increase in runoff generated by increase in precipitation in the future. The runoff in the upper and middle reaches of the Yellow River in 2050 and 2070 are projected to be 9% and 7% lower, respectively, than those in the reference period. The ensemble projection method proposed in this paper can be used as a widely applicable process in hydrometeorological ensemble projection and provides a basis for water resource management planning.
Evidence of Nighttime Production of Organic Nitrates During SEAC4RS, FRAPPÉ, and KORUS‐AQ
Authors: Kenagy Hannah S. , Sparks Tamara L. , Wooldridge Paul J. , Weinheimer Andrew J. , Ryerson Thomas B. , Blake Donald R. , Hornbrook Rebecca S. , Apel Eric C. , Cohen Ronald C.
Published: May 2020

Organic nitrates (RONO2) are an important NOx sink. In warm, rural environments dominated by biogenic emissions, nocturnal NO3‐initiated production of RONO2 is competitive with daytime OH‐initiated RONO2 production. However, in urban areas, OH‐initiated production of RONO2 has been assumed dominant and NO3‐initiated production considered negligible. We show evidence for nighttime RONO2 production similar in magnitude to daytime production during three aircraft campaigns in chemically distinct summertime environments: Studies of Emissions and Atmospheric Composition, Clouds, and Climate Coupling by Regional Surveys (SEAC4RS) in the rural Southeastern United States, Front Range Air Pollution and Photochemistry Experiment (FRAPPÉ) in the Colorado Front Range, and Korea‐United States Air Quality Study (KORUS‐AQ) around the megacity of Seoul. During each campaign, morning observations show RONO2 enhancements at constant, near‐background Ox (≡ O3+NO2) concentrations, indicating that the RONO2 are from a non‐photochemical source, whereas afternoon observations show a strong correlation between RONO2 and Ox resulting from photochemical production. We show that there are sufficient precursors for nighttime RONO2 formation during all three campaigns. This evidence impacts our understanding of nighttime NOx chemistry.
Divergence of Sediment Fluxes Triggered by Sea‐Level Rise Will Reshape Coastal Bays
Authors: Zhang Xiaohe , Leonardi Nicoletta , Donatelli Carmine , Fagherazzi Sergio
Published: May 2020

Sediment budget and sediment availability are direct metrics for evaluating the resilience of coastal bays to sea‐level rise (SLR). Here we use a high‐resolution numerical model of a tidally dominated marsh‐lagoon system to explore feedbacks between SLR and sediment dynamics. SLR augments tidal prism and inundation depth, facilitating sediment deposition on the marsh platform. At the same time, our results indicate that SLR enhances ebb‐dominated currents and increases sediment resuspension, reducing the sediment‐trapping capacity of tidal flats and bays and leading to a negative sediment budget for the entire system. This bimodal distribution of sediments budget trajectories will have a profound impact on the morphology of coastal bays, increasing the difference in elevation between salt marshes and tidal flats and potentially affecting intertidal ecosystems. Our results also clearly indicate that landforms lower with respect to the tidal frame are more affected by SLR than salt marshes.
Simultaneous Observations of Localized and Global Drift Resonance
Authors: Hao Y. X. , Zhao X. X. , Zong Q.‐G. , Zhou X.‐Z. , Rankin R. , Chen X. R. , Liu Y. , Fu S. Y. , Blake J. B. , Reeves G. D. , Claudepierre S. G.
Published: May 2020

In this study, we present Van Allen Probe observations showing that seed (hundreds of keV) and core (
1 MeV) electrons can resonate with ultra‐low‐frequency (ULF) wave modes with distinctive m values simultaneously. An unusual electron energy spectrogram with double‐banded resonant structure was recorded by energetic particle, composition, and thermal plasma (ECT)‐magnetic electron ion spectrometer (MagEIS) and, meanwhile, boomerang stripes in pitch angle spectrogram appeared at the lower energy band. A localized drift resonance with m = 10 wave component was responsible for the resonant band peaked at ∼200 keV while a global drift resonance with m = 3 component gave rise to the upper band resonance peaked at ∼1 MeV. Time‐Of‐Flight on boomerang stripes suggested that the localized drift resonance with ∼200 keV electrons was confined within the plasmaspheric plume. Electron flux modulations were reproduced by numerical simulations in good consistency with the observations, supporting the scenario that localized and global drift resonance could coexist in the outer belt electron dynamics simultaneously.
The 2020 Mw 6.8 Elazığ (Turkey) Earthquake Reveals Rupture Behavior of the East Anatolian Fault
Authors: Pousse‐Beltran Léa , Nissen Edwin , Bergman Eric A. , Cambaz Musavver Didem , Gaudreau Élyse , Karasözen Ezgi , Tan Fengzhou
Published: May 2020

The 2020 Mw 6.8 Elazığ earthquake was the largest along the East Anatolian Fault (EAF) in over a century, providing valuable insights into its rupture behavior. We use satellite geodesy and seismology to detail the mainshock rupture, postseismic deformation, and aftershocks. The mainshock propagated mostly westward at ∼2 km/s from a nucleation point on an abrupt ∼10° fault bend. Only one end of the rupture corresponds to an established EAF segment boundary, and the earthquake may have propagated into the slip zone of the 1874 M ∼ 7.1 Gölcuk Gölu earthquake. It exhibits a pronounced (∼80%) shallow slip deficit, only a small proportion of which is recovered by early aseismic afterslip. The slow rupture velocity, shallow slip deficit, and minimal afterslip are characteristic of earthquakes hosted by faults of low‐to‐intermediate structural maturity, indicating that faults continue to evolve in important ways even as they accrue cumulative offsets of tens of kilometers.
Revisiting the Relationship Between Tropical Cyclone Size and Intensity Over the Western North Pacific
Authors: Song Jinjie , Duan Yihong , Klotzbach Philip J.
Published: May 2020

This study revisits the nonlinear relationship between tropical cyclone (TC) size and intensity over the western North Pacific (WNP). Using best track data from the Japan Meteorological Agency from 2007–2019, we find that the statistical turning point on a fitted size‐intensity curve only exists for TCs with greater lifetime peak intensities (e.g., typhoons). The track and evolution type are two factors determining the statistical size‐intensity relationship. The nonlinear size‐intensity relationship is only observed for recurving typhoons reaching their peak intensities and sizes at different times, due to a nonmonotonic size change during the weakening stage. The slight size decrease in the initial weakening stage can be linked to a TC weakening‐induced shrinkage balanced by a baroclinic expansion when recurving typhoons move into higher latitudes. Finally, different evolution types for WNP typhoons can be determined by the ratio of intensity/size to its theoretical maximum.
Theoretical characterization of the electronic properties of heterogeneous vertical stacks of 2D metal dichalcogenides containing one doped layer
Authors: Slassi Amine , Cornil David , Cornil Jérôme
Published: May 2020

The rise of van der Waals hetero-structures based on transition metal dichalcogenides (TMDs) opens the door to a new generation of optoelectronic devices.
Dual‐active‐bridge DC–DC converter with auxiliary parallel networks for wide load range ZVZCS application
Authors: Tang Yuanhong , Hu Weihao , Chen Zhangyong , Huang Qi , Blaabjerg Frede
Published: May 2020

In this study, a wide load range zero‐voltage zero‐current switching (ZVZCS) dual‐active‐bridge DC–DC converter using auxiliary parallel networks is proposed. The outstanding feature of the proposed converter is that all of the switches are allowed to operate with zero‐voltage switching while four of the switches are allowed to operate with zero‐current switching, due to the use of two auxiliary parallel networks, which were paralleled to two active bridges, respectively. Furthermore, the circulating current losses can be reduced significantly by using unified boundary trapezoidal modulation method. Based on these merits, the proposed converter has some advantages for the wide range load variation applications with less circulating current losses. The operation principles, soft‐switching conditions and loss analyses comparison are given in this study. These benefits and characteristics mentioned above are verified from the experimental results by using a 1 kW prototype.
Optimal working state tracking method and experiments on inductive contactless power transmission system
Authors: Huo Fangqiang , Li Yansong , Wan Jun , Wang Minhao , Liu Jun
Published: May 2020

To address the problems of traditional frequency tracking, such as falling into a local optimum, oscillation near the optimal point, and contradiction between tracking speed and tracking accuracy, an improved perturb–observe method based on component drift parametric scanning is proposed. An inductive contactless power transmission system with LCC/S third‐order compensation topology is employed as the research object. First, the relationships between the output voltage and frequency under component drift parametric scanning are given by theoretical deduction and calculation. Then, a reasonable working frequency band is intercepted, and the improved perturb–observe method (including start, end, step, and anti‐death cycle judgement) is used to track the optimal working state adaptively. Finally, the correctness of the proposed theory and method was verified by simulations and physical experiments.
Buck converter IC for brushless DC motor drive using voltage‐mode PWM controller
Authors: Sung Guo‐Ming , Lee Chun‐Ting , Chen Zhao‐Long
Published: May 2020

This study proposes a buck converter IC with voltage‐mode pulse‐width modulation (PWM) controller to provide a stable bias voltage for the brushless DC motor drive. The proposed buck converter IC comprises an error amplifier, a hysteresis comparator, a linear ramp generator, a driving circuit, a non‐overlapping circuit, a bootstrap circuit and a level shifter. By integrating these proposed circuits into a single chip, the performance of buck converter chip could be improved significantly. The PWM controlled signal was used to generate a suitable output voltage by modifying the duty cycle. The advantage of this method is that the control method of the feedback circuit can be implemented easily, has a short ON time, and has effective noise immunity. After verifying the designed functions, the proposed IC was fabricated using TSMC 0.25 μm 1P3M complementary metal oxide semi‐mixed signal process. Measurement results illustrate that the output voltage, output current, line regulation, load regulation, output ripple voltage and peak power efficiency were 5 V, 200 mA, 13.33 mV/V, 18.5 mV/A, 30 mV, and 68%, respectively, at an input voltage of 15 V and a switching frequency of 100 kHz. The chip area was ∼1.480 × 0.999 mm2.
Two‐parameter Kautz network‐based LTV‐MPC for non‐linear standalone micro‐grid control
Authors: Puvvula Vidyasagar , Verma Pranjal Pragya , Kesanakurthy Shanti Swarup
Published: May 2020

This study proposes a novel linear time‐variant model predictive controller (LTV‐MPC) for the centralised control of non‐linear standalone micro‐grids. At each sample, within the prediction horizon, LTV‐MPC linearises the non‐linear micro‐grid model around the state and input reference trajectories resulting in a linear time‐variant (LTV) model. The LTV model is used for predicting the forced response of the micro‐grid. The natural response is predicted by solving the non‐linear model along the state and input reference trajectories. An optimal control problem for the LTV‐MPC is formulated using the complete predicted response, which is a quadratic programming problem instead of a non‐convex non‐linear programming problem. The quadratic programming problem is solved online at each sample to generate the optimal control trajectories within the control horizon. The study recommends the use of two‐parameter orthonormal Kautz networks in the LTV‐MPC design for the control trajectories approximation. The approximation drastically reduces the number of optimising variables in the optimal control problem without compromising LTV‐MPC performance. A standalone eight bus micro‐grid with one synchronous distributed generator (DG) and one photovoltaic‐DG is considered for the analysis. The LTV‐MPC performance is assessed for the different load disturbance and source intermittency scenarios. The results are compared with the existing MPC designs.
PLL parameters tuning guidelines to increase stability margins in multiple three‐phase converters connected to weak grids
Authors: Nicolini André , Pinheiro Humberto , Carnielutti Fernanda , Massing Jorge
Published: May 2020

This study investigates the stability of multiple three‐phase converters connected to weak grids. It has been derived a flexible modelling regarding the number of converter and type of collector system. The both eigenvalues and impedance based methods are applied to the stability analysis. The eigenvalues method is used to give guidelines on the choice of the phase‐looked loop (PLL) gains. To improve the stability margins, the increase in the PLL damping ratio is proposed. Moreover, it is used to investigate the PLL interaction with converter current and DC bus voltage controllers. The impedance based method extends the stability analysis to multiple three‐phase converters. In addition, it has been used to show the effects of converter current and DC bus voltage controllers parameters on the stability margins. Finally, in order to validate the theoretical analysis, time‐domain results with hardware‐in‐the‐loop are given, showing a strong correlation with the theoretical analysis in the frequency domain.
Energy management strategy of active distribution network with integrated distributed wind power and smart buildings
Authors: Li Zening , Su Su , Zhao Yuming , Jin Xiaolong , Chen Houhe , Li Yujing , Zhang Renzun
Published: May 2020

Aiming to achieve the flexible operation of distribution network (ADN), an energy management strategy of ADN with integrated distributed wind power and smart buildings is proposed in this study. First, based on the thermal storage characteristics of buildings, the resistor–capacitor model is used to develop an energy consumption prediction model of smart buildings. Second, the smart buildings are modelled as flexible resources of ADN. A multi‐objective ADN model is further formulated based on analytic hierarchy process (AHP) by comprehensively considering constraints of power grid and smart buildings. Then, the unified model of ADN is transformed by second‐order conic relaxation to guarantee the global optimal solution. Finally, the scheduling results for the unified model of ADN under different control methods for heating ventilation and air‐conditioning (HVAC) systems are compared in the winter heating scenario. In addition, the impact of the demand response capability for smart buildings on the economic and secure operation of the ADN is further analysed. Numerical studies demonstrate that the proposed method can increase the penetration of local wind power, reduce peak‐valley load difference and network loss of the grid while ensuring the comfort temperature of customers, and further achieve the flexible operation of ADN.
Metaheuristics optimized machine learning modelling for estimation of exergetic emissions of a propulsion system
Authors: Baklacioglu Tolga , Turan Onder , Aydin Hakan
Published: May 2020

You This study offers a metaheuristic design for primary parameters and architectures of two models of artificial neural network (ANN) in predicting a business jet aircraft’s exergo-emission parameters, such us exergy destruction ratio (rex,dest) and waste exergy ratio (rwex), at different flight stages. In consideration of this, the development of hybrid genetic algorithm (GA)-ANN models has been achieved by considering real databases of rex, dest and rwex at various power levels. Implementing a metaheuristics-based optimization on the generated multilayer perceptron (MLP) ANN models has produced the most favorable initial network weights, step-size, biases as well as training algorithm’s back-propagation (BP) momentum rate in addition to optimal quantity of neurons in the hidden layer(s) with regard to the topology design. In accordance with an error assessment approach, there exists a close fit linking the reference real data and rwex (linear correlation ratio, R, value of 0.999851) as well as rex,dest (R value of 0.999985) predicted values.
1.2kW Interleaved synchronous buck converter design for aviation systems
Authors: Sener Eralp , Yazar Isil , Ertasgin Gurhan , Yamık Hasan
Published: May 2020

The principal aim of this work is to design a battery-operated 1.2kW interleaved synchronous buck converter for aviation systems to obtain lower losses compared to the existing topologies. It is desired to achieve at least a 5% loss reduction. Military aircrafts such as F-22 and civil aircraft as Boeing 787 are using the 270V DC for their battery systems. Although 270V DC system has some advantages such as reducing loses and the passive element sizes, old avionics that have been designed, produced and used since the second world war may not be compatible with the 270V DC system. Conversion from 270V to 28V appears to be quite promising for both old and new systems. Therefore, a buck converter design for 270 to 28V conversion is proposed in this study to adapt older avionics technology to accommodate new achievements. The analysis of the SiC MOSFET based interleaved synchronous buck converter with a double loop PI controller is presented. The paper demonstrates the principles of the design and discusses possible future developments. The concept is verified using simulations.
The assessment of commercial flights emissions at Ordu-Giresun Airport, Turkey
Authors: Orhan I.
Published: May 2020

Ordu-Giresun International Airport is Turkey’s first and world’s second airport built on the sea. This study provides the pollutant gas emitted from aircraft with carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) during landing and take-off cycles in Ordu-Giresun International Airport in 2015. It also presents the fuel burnt. For emission calculation, ICAO’s database for aircraft engine emission data and General Directorate of State Airports Authority’s database for flight records were used. In the calculations, a sensitivity analysis was made by taking into consideration the aircraft types and engine types used by the airline companies on the flights to Ordu-Giresun International Airport.
Mit TCM aus der Schmerzspirale
Authors: Bögel-Witt Martina
Published: May 2020

Eine 56-jährige Patientin stellt sich mit starken chronischen Schmerzen am ganzen Körper sowie Erschöpfung in der Praxis vor, leidet aber auch an Depression, Hashimoto-Thyreoiditis und Adipositas. Die chinesische Diagnostik ergibt einen Milz-Qi-Mangel, eine Leber-Qi-Stagnation und ein geschwächtes Zang-Organ Lunge. Mit einer Kräuterrezeptur, Akupunktur, Tuina-Massage, Qi Gong und einer überraschenden Entscheidung gehen die Schmerzen und die empfundene Hilflosigkeit spürbar zurück.
A Gap in Care? Postpartum Women Presenting to the Emergency Room and Getting Readmitted
Authors: Patel Shivani , Rodriguez Aldeboran N. , Macias Devin A. , Morgan Jamie , Kraus Alexandria , Spong Catherine Y.
Published: May 2020

Objective Emergent postpartum hospital encounters in the first 42 days after birth are estimated to complicate 5 to 12% of births. Approximately 2% of these visits result in admission. Data on emergent visits and admissions are critically needed to address the current maternal morbidity crisis. Our objective is to characterize trends in emergent postpartum hospital encounters and readmissions through chief complaints and admission diagnoses over a 4.5-year period.

Study Design All postpartum hospital encounters within 42 days of delivery at our institution from 2015 to 2019 were included. We reviewed demographic information, antepartum, intrapartum, and postpartum care and postpartum hospital encounters. Trends in hospital presentation and admission over the study period were analyzed. Comparisons between women who were admitted to those managed outpatient were performed. Statistical analysis included Chi-square, student's t-test, and Mantel–Haenszel test for trend and ANOVA, as appropriate. A p-value <0.05 considered significant.

Results Among 8,589 deliveries, 491 (5.7%) presented emergently to the hospital within 42 days of delivery, resulting in 576 hospital encounters. From 2015 to 2019, annual rates of presentation were stable, ranging from 5.0 to 6.4% (p = 0.09). Of the 576 hospital encounters, 224 (38.9%) resulted in an admission with increasing rates from 2.0% in 2015 to 3.4% in 2019 (p = 0.005). Primiparous women with higher body mass index, cesarean delivery, and blood loss ≥1, 000 mL during delivery were significantly more likely to be admitted to the hospital. Women with psychiatric illnesses increasingly utilized the emergency room in the postpartum period (6.7–17.2%, p = 0.03). The most common presenting complaints were fever, abdominal pain, headache, vaginal bleeding, wound concerns, and high blood pressure. Admitting diagnoses were predominantly hypertensive disorder (22.9%), wound complications (12.8%), endometritis (9.6%), headache (6.9%), and delayed postpartum hemorrhage (5.6%).

Conclusion The average proportion of women presenting for an emergent hospital encounter in the immediate 42-day postpartum period is 5.7%. Nearly 40% of emergent hospital encounters resulted in admission and the rate increased from to 2.0 to 3.4% over the study period. The most common reasons for presentation were fever, abdominal pain, headache, vaginal bleeding, wound concerns, and hypertension. Hypertension, wound complications, and endometritis accounted for the top three admission diagnoses.
Pharmacological Agents Targeting Thromboinflammation in COVID-19: Review and Implications for Future Research
Authors: Madhavan Mahesh V. , Bikdeli Behnood , Gupta Aakriti , Jimenez David , Burton John R. , Der Nigoghossian Caroline , Chuich Taylor , Nouri Shayan Nabavi , Dreyfus Isaac , Driggin Elissa , Sethi Sanjum , Sehgal Kartik , Chatterjee Saurav , Ageno Walter , Madjid Mohammad , Guo Yutao , Tang Liang V. , Hu Yu , Bertoletti Laurent , Giri Jay , Cushman Mary , Quéré Isabelle , Dimakakos Evangelos P. , Gibson C. Michael , Lippi Giuseppe , Favaloro Emmanuel J. , Fareed Jawed , Tafur Alfonso J. , Francese Dominic P. , Batra Jaya , Falanga Anna , Clerkin Kevin J. , Uriel Nir , Kirtane Ajay , McLintock Claire , Hunt Beverley J. , Spyropoulos Alex C. , Barnes Geoffrey D. , Eikelboom John W. , Weinberg Ido , Schulman Sam , Carrier Marc , Piazza Gregory , Beckman Joshua A. , Leon Martin B. , Stone Gregg W. , Rosenkranz Stephan , Goldhaber Samuel Z. , Parikh Sahil A. , Monreal Manuel , Krumholz Harlan M. , Konstantinides Stavros V. , Weitz Jeffrey I. , Lip Gregory Y. H. ,   The Global COVID-19 Thrombosis Collaborative Group
Published: May 2020

Coronavirus disease 2019 (COVID-19), currently a worldwide pandemic, is a viral illness caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The suspected contribution of thrombotic events to morbidity and mortality in COVID-19 patients has prompted a search for novel potential options for preventing COVID-19-associated thrombotic disease. In this article by the Global COVID-19 Thrombosis Collaborative Group, we describe novel dosing approaches for commonly used antithrombotic agents (especially heparin-based regimens) and the potential use of less widely used antithrombotic drugs in the absence of confirmed thrombosis. Although these therapies may have direct antithrombotic effects, other mechanisms of action, including anti-inflammatory or antiviral effects, have been postulated. Based on survey results from this group of authors, we suggest research priorities for specific agents and subgroups of patients with COVID-19. Further, we review other agents, including immunomodulators, that may have antithrombotic properties. It is our hope that the present document will encourage and stimulate future prospective studies and randomized trials to study the safety, efficacy, and optimal use of these agents for prevention or management of thrombosis in COVID-19.
Longitudinal analysis reveals transition barriers between dominant ecological states in the gut microbiome
Authors: Levy Roie , Magis Andrew T. , Earls John C. , Manor Ohad , Wilmanski Tomasz , Lovejoy Jennifer , Gibbons Sean M. , Omenn Gilbert S. , Hood Leroy , Price Nathan D.
Published: May 2020

Significance

Deep molecular phenotyping of individuals provides the opportunity for biological insight into host physiology. As the human microbiome is increasingly being recognized as an important determinant of host health, understanding the host–microbiome relationship in a multiomics context may pave the way forward for targeted interventions. In this study, we analyze gut microbial composition of 101 individuals over the course of a year, alongside clinical markers and serum metabolomics. We establish association between specific gut compositional states and host health biomarkers (e.g., of inflammation). Finally, we provide evidence for an apparent transition barrier between these compositional states. A deeper understanding of microbiome dynamics and the associated variation in host phenotypes furthers our ability to engineer effective interventions that optimize wellness.
Systemic signaling during abiotic stress combination in plants
Authors: Zandalinas Sara I. , Fichman Yosef , Devireddy Amith R. , Sengupta Soham , Azad Rajeev K. , Mittler Ron
Published: May 2020

Extreme environmental conditions, such as heat, salinity, and decreased water availability, can have a devastating impact on plant growth and productivity, potentially resulting in the collapse of entire ecosystems. Stress-induced systemic signaling and systemic acquired acclimation play canonical roles in plant survival during episodes of environmental stress. Recent studies revealed that in response to a single abiotic stress, applied to a single leaf, plants mount a comprehensive stress-specific systemic response that includes the accumulation of many different stress-specific transcripts and metabolites, as well as a coordinated stress-specific whole-plant stomatal response. However, in nature plants are routinely subjected to a combination of two or more different abiotic stresses, each potentially triggering its own stress-specific systemic response, highlighting a new fundamental question in plant biology: are plants capable of integrating two different systemic signals simultaneously generated during conditions of stress combination? Here we show that plants can integrate two different systemic signals simultaneously generated during stress combination, and that the manner in which plants sense the different stresses that trigger these signals (i.e., at the same or different parts of the plant) makes a significant difference in how fast and efficient they induce systemic reactive oxygen species (ROS) signals; transcriptomic, hormonal, and stomatal responses; as well as plant acclimation. Our results shed light on how plants acclimate to their environment and survive a combination of different abiotic stresses. In addition, they highlight a key role for systemic ROS signals in coordinating the response of different leaves to stress.