bluuebunny/crossref_metadata_2025 huggingface dataset:
Speckles and paraspeckles coordinate to regulate HSV-1 genes transcription
Authors: Li Kun , Wang Ziqiang
Published: October 2021

Numbers of nuclear speckles and paraspeckles components have been demonstrated to regulate herpes simplex virus 1 (HSV-1) replication. However, how HSV-1 infection affects the two nuclear bodies, and whether this influence facilitates the expression of viral genes, remains elusive. In the current study, we found that HSV-1 infection leads to a redistribution of speckles and paraspeckles components. Serine/arginine-rich splicing factor 2 (SRSF2), the core component of speckles, was associated with multiple paraspeckles components, including nuclear paraspeckles assembly transcript 1 (NEAT1), PSPC1, and P54nrb, in HSV-1 infected cells. This association coordinates the transcription of viral genes by binding to the promoters of these genes. By association with the enhancer of zeste homolog 2 (EZH2) and P300/CBP complex, NEAT1 and SRSF2 influenced the histone modifications located near viral genes. This study elucidates the interplay between speckles and paraspeckles following HSV-1 infection and provides insight into the mechanisms by which HSV-1 utilizes host cellular nuclear bodies to facilitate its life cycle.
Three-dimensional tracking of the ciliate Tetrahymena reveals the mechanism of ciliary stroke-driven helical swimming
Authors: Marumo Akisato , Yamagishi Masahiko , Yajima Junichiro
Published: October 2021

Helical swimming in free-space is a common behavior among microorganisms, such as ciliates that are covered with thousands hair-like motile cilia, and is thought to be essential for cells to orient directly to an external stimulus. However, a direct quantification of their three-dimensional (3D) helical trajectories has not been reported, in part due to difficulty in tracking 3D swimming behavior of ciliates, especially Tetrahymena with a small, transparent cell body. Here, we conducted 3D tracking of fluorescent microbeads within a cell to directly visualize the helical swimming exhibited by Tetrahymena. Our technique showed that Tetrahymena swims along a right-handed helical path with right-handed rolling of its cell body. Using the Tetrahymena cell permeabilized with detergent treatment, we also observed that influx of Ca2+ into cilia changed the 3D-trajectory patterns of Tetrahymena swimming, indicating that the beating pattern of cilia is the determining factor in its swimming behavior.
4-Amino-1,8-naphthalimide–ferrocene conjugates as potential multi-targeted anticancer and fluorescent cellular imaging agents
Authors: Johnson Alex D. , Buhagiar Joseph A. , Magri David C.
Published: October 2021

Eight ferrocenyl 4-amino-1,8-naphthalimide logic gates for acidity and oxidisability are repurposed as anti-proliferation and cellular imaging agents against MCF-7 and K562 cancer cell lines.
Capabilities of inverse scheme for acoustic source localization at low frequencies
Authors: Gombots Stefan , Kaltenbacher Manfred , Kaltenbacher Barbara
Published: October 2021

We present the capabilities of a recently developed inverse scheme for source localization at low frequencies within an arbitrary acoustic environment. The inverse scheme is based on minimizing a Tikhonov functional matching measured microphone signals with simulated ones. We discuss the sensitivity of all involved parameters, the precision of geometry and physical boundary modeling for the numerical simulation using the finite element (FE) method, and the automatic determination of the positions of the recording microphones being distributed around the object of investigation. Finally, we apply the inverse scheme to a real-world scenario and compare the obtained results to state-of-the-art signal processing approaches, e.g. Clean-SC.
Étude de l’influence de l’incorporation de la poudre de bois d’Eucalyptus camaldulensisDehn algérien sur la cinétique d’hydratation du coulis de ciment
Authors: Anes Linda , Tazrout Mansour , Govin Alexandre
Published: October 2021

Pour réduire le problème d’incompatibilité entre le bois et le ciment, un traitement du renfort bois, par de l’eau bouillante peut être une solution afin d’éliminer les composés qui inhibent la prise du ciment. L’effet de la teneur de poudre de bois d’Eucalyptus camaldulensisDehn naturel et traité thermiquement à l’eau bouillante sur la cinétique d’hydratation a été étudié par calorimétrie isotherme, conductimétrie et thermogravimétrie (ATG). La poudre de bois diminue légèrement la consommation du gypse et retarde l’hydratation des phases silicates. À des concentrations massiques élevées de 25 % et 30 %, le bois retarde fortement la précipitation de la portlandite. À des teneurs de 10 % en masse de poudre de bois, le traitement n’a pas montré d’efficacité sur la cinétique d’hydratation ; à 20 % de bois traité, l’hydratation du ciment est accélérée par rapport au témoin. Les extractibles du bois n’ont pas affecté la formation de l’ettringite due à la présence d’ions de sulfate de bois.
Modellvorhaben POLKA: Bewegungsempfehlungen für Pflegende und Pflegebedürftige
Authors: Baldus Angelika , Peters Stefan
Published: October 2021

Die Maßnahmen des Modellvorhabens POLKA (Pflegeeinrichtungen als Kompetenzzentren in der Gesundheitsversorgung durch Multiplikation körperlicher Aktivität, siehe auch Beitrag „Modellvorhaben POLKA 2.0“ in diesem Heft) zielen auf die Verhaltens- wie auch Verhältnisprävention und beziehen sowohl die Nationalen Empfehlungen für Bewegung und Bewegungsförderung (NEBB) 1 als auch die aktuellen Bewegungsempfehlungen der Weltgesundheitsorganisation WHO 2 mit ein.
Cardiac Arrest during Cesarean Section – A Case Report and
Review of the Differential Diagnosis
Authors: Lukac Stefan , Mayer Sebastian , Mühlen Kathrin , Flock Felix
Published: October 2021

Aim According to the World Health Organization, approximately 810 pregnant
women die every day as a consequence of peripartum complications. A large
proportion of deaths happen in developing countries. Peripartum cardiac arrest
is a rare event that must be treated immediately. It is important to consider
the differential diagnoses in order to save lives.

Methods In this review, we discuss a differential diagnosis of cardiac
arrest according to the BEAU-CHOPS scheme of the American Heart Association in
the relation to the case report of our 40-year-old G5/P3 patient who
went into cardiac arrest during cesarean delivery.

Results Typical differentials for cardiac arrest during labor are
bleeding, embolism, anesthetic complications, cardiovascular diseases,
eclampsia, and sepsis. All of them were considered and ruled out in this
patient. In the end, we suspect that physiological cardio-inhibitory reflexes
triggered by sudden profound hypovolemia after placental separation along with
the patientʼs risk factors, especially obesity and maternal age, and the
administration of spinal anesthesia all potentially contributed to the cardiac
arrest.

Conclusions This review highlights that the cardiac arrest during labor
can be triggered by the multifactorial etiology, but firstly the typical
differential diagnosis needs to be excluded.
Rare Report Case of Oral Verruca Vulgaris on Torus Palatinus
Authors: Khoo Lee Kian , Chai Low Eng , Bhattarai Bishwa Prakash , Rokaya Dinesh , Yongvanichakorn Boonaur , Wongsirichat Natthamet
Published: October 2021

Verruca vulgaris, also known as common warts, is most often seen on the skin of hands and feet. Human papilloma virus (HPV) plays an aetiological role in the development of this lesion. Oral verruca vulgaris (OVV) may occur on the palate, buccal mucosa, and tongue. Although asymptomatic and benign, HPV has been linked to squamous cell carcinoma in the oral cavity and oropharyngeal areas. Therefore, prompt surgical removal of OVV is warranted. We report a case of a OVV in a 48-year-old male patient on palate. The lesion was a white nonscrapable lesion in the middle of a torus palatinus. Excisional biopsy was done together with surgical removal of torus palatinus. Histopathological analysis confirmed the diagnosis of OVV.
Decreased Cerebral Oxygenation in Premature Infants with Progressive Posthemorrhagic Ventricular Dilatation May Help with Timing of Intervention
Authors: June Angelina , Heck Timothy , Shah Tushar A. , Vazifedan Turaj , Bass William Thomas
Published: October 2021

Objective The objective of this study was to determine the degree of progressive posthemorrhagic ventricular dilatation (PHVD) that is associated with a significant decrease in regional cerebral oxygen saturation (rScO2) in premature infants at risk for periventricular–intraventricular hemorrhage (PIVH).

Study Design Cranial ultrasound (US) and near-infrared spectroscopy (NIRS) measurements of rScO2 were performed on inborn infants with birth weights less than 1,250 g on admission and at 1, 4, and 8 weeks of age. Infants with severe PIVH were studied weekly. A 1-hour average of rScO2 was compared with the frontal–occipital horn ratio (FOHR) measured the same day. Generalized linear models were used to analyze the relationship between FOHR and rScO2, by severity of PIVH, and adjusted for gestational age. Cut-off points of 0.55 for FOHR and 45% for rScO2 were used to calculate odds ratios (OR) and 95% confidence intervals (CI).

Results The study cohort included 63 infants with normal US, 15 with grade-1 or -2 PIVH (mild group), and 21 with grade-3 or -4 PIVH (severe group). Increases in FOHR in the severe group were associated with decreases in rScO2 at 1 week (p = 0.036), 4 weeks (p = 0.013), and 8 weeks of life (p = 0.001) compared with the normal and mild groups. Infants with FOHR greater than 0.55 were 92% more likely to have rScO2 less than 45% when compared with infants with FOHR less than 0.55 (OR = 0.08, 95% CI: [0.04, 0.13], p < 0.001).

Conclusion Progressive PHVD (FOHR > 0.55) is a strong predictor of compromised cerebral oxygenation. A combination of rScO2 and FOHR measurements may aid in identifying infants with PHVD that would benefit from early intervention.

Key Points
Reticulocyte Count: The Forgotten Factor in Transfusion Decisions for Extremely Low Birth Weight Infants
Authors: Nakhla Daniel , Kushnir Alla , Ahmed Rafat , Bhandari Vineet , Hunter Krystal , Nakhla Tarek
Published: October 2021

Objective Extremely low birth weight (ELBW) infants often receive transfusions of packed red blood cells (PRBCs). Long-term outcomes of infants treated with liberal versus restricted transfusion criteria have been evaluated with conflicting results. Clinicians incorporate a reticulocyte count (RC) in their transfusion decisions. There is a lack of information on reference ranges for RCs in growing ELBW infants and whether infant's chronologic age or corrected gestational age (GA) generates a specific trend in the RCs. Our aim was to evaluate the levels of RCs obtained from ELBW infants over the course of the initial hospitalization.

Study Design A retrospective chart review of ELBW infants treated in the neonatal intensive care unit (NICU) and had RCs performed. We analyzed the RCs to observe trends based on the chronologic age and corrected GA.

Results A total of 738 RCs were analyzed. A positive trend in RCs that reached a peak at 32 to 34 weeks' corrected GA and then experienced a downward trend was observed.

Conclusion Our report examines a very common hematologic test that is theoretically helpful but is in need of guidelines concerning the appropriate frequency of testing and its utility in making transfusion decisions in ELBW infants.

Key Points
Synchronizability of two-layer correlation networks
Authors: Wei Xiang , Wu Xiaoqun , Lu Jun-An , Wei Juan , Zhao Junchan , Wang Yisi
Published: October 2021

This study investigates the synchronizability of a typical type of two-layer correlation networks formed by two regular networks interconnected with two interlayer linking patterns, namely, positive correlation (PC) and negative correlation (NC). To analyze the network’s stability, we consider the analytical expressions of the smallest non-zero and largest eigenvalues of the (weighted) Laplacian matrix as well as the linking strength and the network size for two linking patterns. According to the master stability function, the linking patterns, the linking strength, and the network size associated with two typical synchronized regions exhibit a profound influence on the synchronizability of the two-layer networks. The NC linking pattern displays better synchronizability than the PC linking pattern with the same set of parameters. Furthermore, for the two classical synchronized regions, the networks have optimal intralayer and interlayer linking strengths that maximize the synchronizability while minimizing the required cost. Finally, numerical results verify the validity of the theoretical analyses. The findings based on the representative two-layer correlation networks provide the basis for maximizing the synchronizability of general multiplex correlation networks.
NiO/AlGaN interface reconstruction and transport manipulation of p-NiO gated AlGaN/GaN HEMTs
Authors: Guo Hui , Gong Hehe , Yu Xinxin , Wang Rui , Cai Qing , Xue Junjun , Wang Jin , Pan Danfeng , Ye Jiandong , Liu Bin , Chen Dunjun , Lu Hai , Zhang Rong , Zheng Youdou
Published: October 2021

Normally off AlGaN/GaN high electron mobility transistors with a p-type gate are promising for power switching applications, with advantages of low energy consumption and safe operation. In this work, p-NiO is employed as a gate stack, and the interfacial reconstruction and band structure modification at the p-NiO/AlGaN interface have been demonstrated to manipulate channel transport of AlGaN/GaN high electron mobility transistors by post-annealing. In addition to achieving a positive threshold voltage of 0.6 V and a large saturation output current of 520 mA/mm, we found that the gate leakage and On/Off drain current ratio can be improved significantly by more than 104 due to the p-NiO/AlGaN interfacial reconstruction. However, high annealing temperature also results in an increasing ON-resistance and a dramatically increased knee voltage (VK), which can be attributed to the formation of an ultra-thin γ-Al2O3 layer and the substitution of O on N site as a shallow donor at the p-NiO/AlGaN interface confirmed by experimental analyses. Theoretical calculations indicate that such interface reconstruction facilitates an additional potential well at the p-NiO/AlGaN interface to which electrons are spilled out from a two-dimensional electron gas channel under high forward gate voltage, resulting in the increased VK. Finally, an optimized annealing condition was confirmed that can eliminate this increased VK phenomenon and simultaneously remain these significantly improved device performances. These findings provide deep understanding of the performance manipulation of AlGaN high electron mobility transistors, which is very important for engineering the p-NiO/AlGaN interface toward high-performance and stable devices.
On-orbit calibration techniques for optical payloads onboard remote-sensing satellites
Authors: Cui Yang , Yao Xiaosong , Chen Xuedi , Liang Guang , Zhao Shenggang , Li Liangcheng , Ma Hui , Pan Chao , Wang Bingjia , Guo Xiaolu , Zhou Wenmei
Published: October 2021

Errors in the attitude of optical payloads onboard remote-sensing satellites have a significant impact on image quality and high-precision quantification. This study presents two on-orbit calibration techniques for optical payloads. Self-calibration of the orientation of the optical axis of an optical payload can be achieved through on-orbit observation and imaging of star points based on the pinhole imaging principle. Separate on-orbit observation and imaging of star points can facilitate the mutual calibration of an optical payload and a star sensor as well as the correction of their installation errors. These two techniques are validated through ground and on-orbit satellite tests. The results show the following: The self-calibration error for a typical remote-sensing satellite is better than 0.2″ and the mutual-calibration error is better than 2″ for its optical payload and star sensor. Self-calibration and mutual calibration are effective for improving the calibration accuracy for the on-orbit orientation of optical payloads.
Characterization of self-heating in cryogenic high electron mobility transistors using Schottky thermometry
Authors: Choi Alexander Y. , Esho Iretomiwa , Gabritchidze Bekari , Kooi Jacob , Minnich Austin J.
Published: October 2021

Cryogenic low-noise amplifiers based on high electron mobility transistors (HEMTs) are widely used in applications such as radio astronomy, deep space communications, and quantum computing. Consequently, the physical mechanisms governing the microwave noise figure are of practical interest. In particular, the magnitude of the contribution of thermal noise from the gate at cryogenic temperatures remains unclear owing to a lack of experimental measurements of thermal resistance under these conditions. Here, we report measurements of gate junction temperature and thermal resistance in a HEMT at cryogenic and room temperatures using Schottky thermometry. At temperatures ∼20 K, we observe a nonlinear trend of thermal resistance vs power that is consistent with heat dissipation by phonon radiation. Based on this finding, we consider heat transport by phonon radiation at the low-noise bias and liquid helium temperatures and estimate that the thermal noise from the gate is several times larger than previously assumed owing to self-heating. We conclude that without improvements in thermal management, self-heating results in a practical lower limit for microwave noise figure of HEMTs at cryogenic temperatures.
Machine learning evaluates changes in functional connectivity under a prolonged cognitive load
Authors: Frolov Nikita , Kabir Muhammad Salman , Maksimenko Vladimir , Hramov Alexander
Published: October 2021

One must be aware of the black-box problem by applying machine learning models to analyze high-dimensional neuroimaging data. It is due to a lack of understanding of the internal algorithms or the input features upon which most models make decisions despite outstanding performance in classification, pattern recognition, and prediction. Here, we approach the fundamentally high-dimensional problem of classifying cognitive brain states based on functional connectivity by selecting and interpreting the most relevant input features. Specifically, we consider the alterations in the cortical synchrony under a prolonged cognitive load. Our study highlights the advances of this machine learning method in building a robust classification model and percept-related prestimulus connectivity changes over the conventional trial-averaged statistical analysis.
Serotonin modulates melatonin synthesis as an autocrine neurotransmitter in the pineal gland
Authors: Lee Bo Hyun , Hille Bertil , Koh Duk-Su
Published: October 2021

Significance

The pineal gland secretes melatonin at night mainly driven by adrenergic sympathetic inputs. Many other neurotransmitters are found in the pineal gland, suggesting potential fine modulation of melatonin release. Serotonin as a precursor of melatonin synthesis is known to be significantly released by pinealocytes and its receptor also is expressed in pinealocytes. By identifying the release mechanism, cell signaling in the pinealocytes, and its effect on norepinephrine-induced melatonin secretion, our study defines serotonin as an autocrine neurotransmitter in the pineal gland and suggests possible modulatory targets for melatonin secretion.
Analytical and experimental study of the dynamics of a micro-electromechanical resonator based digital-to-analog converter
Authors: Zhao Wen , Ahmed Sally , Fariborzi Hossein , Younis Mohammad I
Published: October 2021

In this paper, an analytical model of a micro-electromechanical (MEM) resonator used as a 4-bit digital-to-analog converter (DAC) is presented. First, we derive the dynamic equation of the 4-bit DAC device, and the nonlinear governing equation is solved by the Galerkin method combined with a shooting technique to simulate the static response, linear eigenvalue problem, and forced vibration response of the device for various electrostatic actuation cases. Also, we optimize the air gaps in the linear domain to ensure enhanced performance of the DAC. Further, to analyze the operation of the DAC in the nonlinear regime, two experimental samples powered by −2 dBm and −12 dBm AC inputs are examined. Forward and backward frequency sweeps are conducted experimentally and analytically. The proposed analytical results are validated by comparison with experimental data. The results indicate that the presented modeling, simulations, and optimization are effective tools for the design of MEM resonator-based circuits.
Vortex formation in a spin–orbit-coupled Bose–Einstein condensates with static quadrupole magnetic field
Authors: Jin Jingjing , Han Wei , Ma Zongmin , Su Ningning
Published: October 2021

The ground-state phases of Rashba spin–orbit (SO)-coupled Bose–Einstein condensates (BECs) in a quadrupole magnetic field are studied. The coupling of quadrupole magnetic field and spin induces local nonzero gauge particle current, accompanied by the generation of equal and opposite canonical particle current, and leads to the spontaneous nucleation of quantized vortices. The condensates exhibit a variety of rich density patterns and vortex arrangements resulting from the competition among quadrupole magnetic field, SO coupling, and interatomic interactions. Novel vortex structures, such as static vortex dipole, three-vortex molecule and the structure of a cross-arranged vortices and anti-vortices surrounded by a density annulus are found in the condensates. These structures greatly enrich the ground-state phases of SO-coupled BECs, and help to understand the superfluid behavior of a BEC and the nonlinear behavior of coherent matter waves.
Multiband tunable thermal camouflage compatible with laser camouflage based on GST plasmonic metamaterial
Authors: Kang Qianlong , Li Dekui , Wang Wei , Guo Kai , Guo Zhongyi
Published: October 2021

In this paper, we propose a simple plasmonic structure based on Ge2Sb2Te5 (GST) to realize tunable multiband camouflage and radiation heat dissipation. In the mid-infrared (MIR) (3–5 μm) range, the proposed structure has average emissivity of 0.18 ∼ 0.76 and can be applied in tunable thermal camouflage as the GST’s crystallization fraction increases from 0 to 1. In the 5–8 μm (safe window) range, radiation heat dissipation of the proposed structure may guarantee thermal stability of the system. In the long-infrared (8–14 μm) range, the designed emitter maintains a relatively stable and low average emissivity of 0.13 ∼ 0.19 when the crystallization fraction of GST changes from 0 to 1. In addition, due to surface lattice resonance of plasmonic metamaterial, our designed emitter can also achieve laser radar camouflage at the wavelength of 10.6 μm. We have also analyzed the dependence of the camouflage performance on the GST’s crystallization fractions, polarization angle and incident angle. Moreover, simulated thermal images demonstrate tunable thermal camouflage for various background temperatures and different ambient backgrounds in the MIR ranges.
Impact of ion beam irradiation on two-dimensional MoS2: a molecular dynamics simulation study
Authors: Wu Xin , Zhu Xiaobao , Lei Bing
Published: October 2021

Two-dimensional (2D) materials such as MoS2 have extraordinary properties and significant application potential in electronics, optoelectronics, energy storage, bioengineering, etc. To realize the numerous application potential, it is needed to modulate the structure and properties of these 2D materials, for which ion beam irradiation has obvious advantages. This research adopted classical molecular dynamics simulations to study the sputtering of atoms in 2D MoS2, defect formation and the control rule under Ar ion beam irradiation, considering the influence of ion irradiation parameters (i.e., ion beam energy, ion dose), layer number of 2D MoS2, substrate. Furthermore, the uniaxial mechanical performance of the ion-irradiated nanostructures was investigated for actual applications loading with mechanical stress/strain. This research could provide important theoretical support for fabricating high-performance 2D MoS2-based nanodevices by ion beam irradiation method.
How much should we be concerned about cumulative effective doses in medical imaging?
Authors: Martin Colin J , Barnard Michael
Published: October 2021

The International Atomic Energy Agency issued a statement calling for action to strengthen the radiation protection of patients undergoing recurrent imaging. This followed reports of patients receiving cumulative effective doses over 100 mSv from multiple computed tomography examinations. In order to evaluate excess risks of cancer incidence among UK patients, data from an exposure management system covering three hospitals within one trust have been studied over 5½ years. Cumulative effective doses for 105 757 patients, from whom 719 (0.68%) received effective dose over 100 mSv, have been analysed using age and sex specific risk factors for stochastic effects. Two cancers might be expected to be initiated in the patients receiving over 100 mSv, while five might be expected to develop cancer among patients receiving 50–100 mSv. However, the calculations ignore health conditions for which the patients are being treated that may shorten their lives, and rely on the linear-no-threshold dose-effect model which is a subject of debate, so they are likely to overestimate cancer incidence. If health of the patients receiving >100 mSv is taken into account, the risk of mortality from cancer initiated by medical exposure might be the order of 1 in 2000. Recommendations on further strengthening of optimisation should be applied to imaging procedures for all patients with special focus on those performed on children and adolescents.
94 GHz microplasma sustained by a photonic crystal
Authors: Hopwood Jeffrey
Published: October 2021

A photonic crystal (PhC) with a single vacancy sustains an argon microplasma at 94 GHz. The PhC consists of a 7 × 13 array of small alumina rods, each 250 μm in radius. The PhC has a forbidden bandgap from 70–105 GHz. The vacancy creates an internal electromagnetic resonance at 94 GHz that intensifies the electric field of an incident wave to 5 × 105 V m−1. Breakdown of low-pressure argon gas (80 mbar) occurs and forms a stable, ellipsoidal plasma inside the crystal. The central core of the microplasma is probed using a 200 μm optical fiber inserted into the PhC. The rotational temperature of the CH molecule is estimated from a numerical fit of the plasma emission and is found to increase from 450–650 K with both pressure (200–1000 mbar) and incident wave power (100 mW–1100 mW). Under these conditions, the electron density increases with both power and pressure from 0.5–1.5 × 1020 m−3. This plasma density range brackets the electron plasma frequency at 94 GHz. The results are compared with a similar microplasma operating at 44 GHz.
Underlying mechanism of the stagnation of positive streamers
Authors: Niknezhad M , Chanrion O , Holbøll J , Neubert T
Published: October 2021

Several publications have shown that it is challenging to model the stagnation of positive streamers. They find that as the streamers propagate, the space charge region at the streamer tip reduces in size and that the associated electric field increases towards infinity. In a recent study on streamer propagation in unsteady airflow, we circumvented this problem by relaxing the local density and electric field approximation in the drift-diffusion model, commonly used in the past models. The results, recently published, show that the electric field remains bounded during the streamer propagation. In the present paper, we explore the process of stagnation further with a more rigorous approach. We confirm that the instability in the electric field is an immediate effect of the local density and field approximation and that an extended description of ionization stabilizes the electric field and leads to a decelerating streamer. Finally, we discuss the role of positive ions in the stagnation and we show that the stagnating streamer velocity decreases till it becomes comparable to the ion velocities in the streamer head. This causes a broadening of the streamer head which leads to a sharp decrease in the streamer tip electric field and the streamer stagnation.
A SiC gate turn-off thyristor with high di/dt for fast switching-on applications
Authors: Li Zhiqiang , Zhang Lin , Li Lianghui , Xu Xingliang , Tao Hong , Meng Yinghao , Zhou Kun , Li Juntao
Published: October 2021

High di/dt 4H-silicon carbide (SiC) gate turn-off thyristors (GTOs) are investigated and developed for fast switching-on application. This work has focused on accelerating the turn-on process to improve the di/dt characteristic, and the n-base dopant concentration is carefully designed to increase the injection efficiency of top P+N junction. With reducing n-base dopant concentration from 2.3 × 1017cm−3 to 6.8 × 1016cm−3, the injection efficiency is increased about 18%, and consequently the current rise-up process and subsequent lateral propagation of the anode current are obviously accelerated. Experimental results show that the di/dt capability is greatly improved and a high di/dt of 126 kA cm−2
μs−1 is obtained. The excellent di/dt performance makes the designed 4H-SiC GTO a promising candidate for fast switching-on application.
Motion parallax for object localization in electric fields
Authors: Hunke Kevin , Engelmann Jacob , Meyer Hanno Gerd , Schneider Axel
Published: October 2021

Parallax, as a visual effect, is used for depth perception of objects. But is there also the effect of parallax in the context of electric field imagery? In this work, the example of weakly electric fish is used to investigate how the self-generated electric field that these fish utilize for orientation and communication alike, may be used as a template to define electric parallax. The skin of the electric fish possesses a vast amount of electroreceptors that detect the self-emitted dipole-like electric field. In this work, the weakly electric fish is abstracted as an electric dipole with a sensor line in between the two emitters. With an analytical description of the object distortion for a uniform electric field, the distortion in a dipole-like field is simplified and simulated. On the basis of this simulation, the parallax effect could be demonstrated in electric field images i.e. by closer inspection of voltage profiles on the sensor line. Therefore, electric parallax can be defined as the relative movement of a signal feature of the voltage profile (here, the maximum or peak of the voltage profile) that travels along the sensor line peak trace (PT). The PT width correlates with the object’s vertical distance to the sensor line, as close objects create a large PT and distant objects a small PT, comparable with the effect of visual motion parallax.
Multimode

-symmetry thresholds and third-order exceptional points in coupled dielectric waveguides with loss and gain
Authors: Hlushchenko Anton V , Novitsky Denis V , Shcherbinin Vitalii I , Tuz Vladimir R
Published: October 2021

A pair of coupled dielectric waveguides with balanced loss and gain is the basic system for observing the phenomena of parity-time (

) symmetry and exceptional points (EPs). We use the multimode analytical approach to study the peculiarities of interaction between the modes excited in such an archetypal structure. With this approach, the conditions for

symmetry breaking are obtained in the special case of the hybrid HE and EH modes resulting in the ordinary second-order EPs (or

-symmetry thresholds). The coupling of modes with the different azimuthal indices (the TM01 and HE21 modes in our study) generates the uncommon types of EPs. First, there are the so-called multimode

-symmetry thresholds due to interaction of hybrid and transverse modes. Second, the third-order EPs appear as a result of three-modes degeneracy of real eigenvalues. It is noteworthy that an increase in the EPs order is achieved without both breaking the

symmetry and introducing additional elements into the waveguide structure. The results obtained with the multimode analytical approach are in perfect agreement with the independent full-wave simulations.
Wireless to optical phase mapping in a seamless digital wireless-photonic link
Authors: Ghosh Niloy , Pendharker Sarang
Published: October 2021

This paper shows that mapping of phase levels of a digitally modulated wireless signal from the mmWave domain to the equivalent optical domain is inherently a non-linear phenomenon in Pockel’s effect-based seamless digital mmWave-to-photonic converters. We report several novel implications of seamless phase mapping, crucial for the realization of seamless wireless-to-photonic links. The latency and design complexity of such converters are expected to be appreciably lower than conventional converters. The results on seamless phase mapping presented in this paper are scalable with the wireless frequency of operation.
Transcriptomic profiling of neonatal mouse granulosa cells reveals new insights into primordial follicle activation
Authors: Ford Emmalee A , Frost Emily R , Beckett Emma L , Roman Shaun D , McLaughlin Eileen A , Sutherland Jessie M
Published: October 2021

The dormant population of ovarian primordial follicles is determined at birth and serves as the reservoir for future female fertility. Yet our understanding of the molecular, biochemical, and cellular processes underpinning primordial follicle activation remains limited. The survival of primordial follicles relies on the correct complement and morphology of granulosa cells, which provide signaling factors essential for oocyte and follicular survival. To investigate the contribution of granulosa cells in the primordial-to-primary follicle transition, gene expression profiles of granulosa cells undergoing early differentiation were assessed in a murine model. Ovaries from C57Bl/6 mice were enzymatically dissociated at time-points spanning the initial wave of primordial follicle activation. Post-natal day (PND) 1 ovaries yielded primordial granulosa cells, and PND4 ovaries yielded a mixed population of primordial and primary granulosa cells. The comparative transcriptome of granulosa cells at these time-points was generated via Illumina NextSeq 500 system, which identified 131 significantly differentially expressed transcripts. The differential expression of eight of the transcripts was confirmed by RT-qPCR. Following biological network mapping via Ingenuity Pathway Analysis, the functional expression of the protein products of three of the differentially expressed genes, namely FRZB, POD1, and ZFX, was investigated with in-situ immunolocalization in PND4 mouse ovaries was investigated. Finally, evidence was provided that Wnt pathway antagonist, secreted frizzled-related protein 3 (FRZB), interacts with a suppressor of primordial follicle activation WNT3A and may be involved in promoting primordial follicle activation. This study highlights the dynamic changes in gene expression of granulosa cells during primordial follicle activation and provides evidence for a renewed focus into the Wnt signaling pathway’s role in primordial follicle activation.
The tube, the pancreatoduodenectomy—and the dogma
Authors: Lassen Kristoffer
Published: October 2021

Routine use of NG-tubes following pancreatoduodenectomies is not indicated
Evaluation of different late left ventricular remodeling definitions for predicting long-term outcomes in acute myocardial infarction patients undergoing percutaneous coronary intervention
Authors: Zhang S , Xie X , He C , Lin X , Luo M , Lin M , Fang M , You Z , Lin K , Guo Y
Published: October 2021

Background

Late left ventricular remodeling (LLVR) after the index acute myocardial infarction (AMI) is a common complication, and is associated with poor outcome. However, the optimal definition of LLVR has been debated because of its different incidence and influence on prognosis. At present, there are limited data regarding the influence of different LLVR definitions on long-term outcomes in AMI patients undergoing percutaneous coronary intervention (PCI).

Purpose

To explore the impact of different definitions of LLVR on long-term mortality, re-hospitalization or an urgent visit for heart failure, and identify which definition was more suitable for predicting long-term outcomes in AMI patients undergoing PCI.

Methods

We prospectively observed 460 consenting first-time AMI patients undergoing PCI from January 2012 to December 2018. LLVR was defined as a ≥20% increase in left ventricular end-diastolic volume (LVEDV), or a >15% increase in left ventricular end-systolic volume (LVESV) from the initial presentation to the 3–12 months follow-up, or left ventricular ejection fraction (LVEF) <50% at follow up. These parameters of the cardiac structure and function were measuring through the thoracic echocardiography. The association of LLVR with long-term prognosis was investigated by Cox regression analysis.

Results

The incidence rate of LLVR was 38.1% (n=171). The occurrence of LLVR according to LVESV, LVEDV and LVEF definition were 26.6% (n=117), 31.9% (n=142) and 11.5% (n=51), respectively. During a median follow-up of 2 years, after adjusting other potential risk factors, multivariable Cox regression analysis revealed LLVR of LVESV definition [hazard ratio (HR): 2.50, 95% confidence interval (CI): 1.19–5.22, P=0.015], LLVR of LVEF definition (HR: 16.46, 95% CI: 6.96–38.92, P<0.001) and LLVR of Mix definition (HR: 5.86, 95% CI: 2.45–14.04, P<0.001) were risk factors for long-term mortality, re-hospitalization or an urgent visit for heart failure. But only LLVR of LVEF definition was a risk predictor for long-term mortality (HR: 6.84, 95% CI: 1.98–23.65, P=0.002).

Conclusions

LLVR defined by LVESV or LVEF may be more suitable for predicting long-term mortality, re-hospitalization or an urgent visit for heart failure in AMI patients undergoing PCI. However, only LLVR defined by LVEF could be used for predicting long-term mortality.

Funding Acknowledgement

Type of funding sources: None. Association Between LLVR and outcomesKaplan-Meier Estimates of the Mortality
Diagnostic and prognostic role of peak troponin T in patients with acute coronary syndromes and non-obstructive coronary arteries
Authors: Williams M G L , Liang K , De Garate E , Spagnoli L , Fiori E , Lawton C B , Dastidar A , Johnson T W , Biglino G , Bucciarelli-Ducci C
Published: October 2021

Background

Up to 10% of patients who present with an acute coronary syndrome have a myocardial infarction with non-obstructive coronary arteries (MINOCA). Troponin T predicts infarct size and outcomes in patients with ST-elevation myocardial infarction. The value of peak troponin T in patients with a working diagnosis of MINOCA is not well understood.

Purpose

The aim of this study is to investigate the diagnostic and prognostic role of troponin in patients with MINOCA.

Methods

Consecutive patients with a working diagnosis of MINOCA from a single tertiary centre who underwent comprehensive cardiovascular magnetic resonance (CMR) imaging with late gadolinium enhancement (LGE) were followed prospectively. Peak troponin T was identified during the index admission and divided into deciles and quartiles for analysis. The primary endpoint was all-cause mortality.

Results

Among 796 patients undergoing CMR, 719 met the study criteria and had underwent a diagnostic quality scan. The peak Troponin T threshold for optimal diagnostic sensitivity and specificity was 211 ng/L. Peak troponin T ≥211 ng/L and time to CMR of ≤14 days has a sensitivity of 94%, specificity of 35%, PPV 57% and NPV 94% for the CMR making a diagnosis. Each increase in troponin decile increases the mean diagnostic yield of the CMR by 3.65% (p<0.001, 95% CI 3.38 – 3.91; R2 0.84; Figure 1).

If the troponin is in the lowest decile and the CMR is performed at ≤14 days, the diagnostic yield is still 72%. There is no overall difference in median troponin in patients who died and those who survived (229 ng/l v. 424 ng/l; p=0.157), however mortality is significantly lower in the highest two troponin quartiles (6.9% versus 11.9%; p=0.009; Figure 2).

Conclusion

Peak troponin T is readily available during the index admission in patients presenting with MINOCA and provides useful diagnostic and prognostic information for the attending cardiologist.

Funding Acknowledgement

Type of funding sources: None. Figure 1. CMR diagnosis by troponin decileFigure 2. Mortality by troponin quartile
Cardiac output monitoring using transthoracic echocardiography in children after cardiac surgery-an observational study of feasibility and concordance with transpulmonary thermodilution
Authors: Guha Niyogi S , Kumar B , Puri G D , Negi S , Mishra A K , Thingnam S K S
Published: October 2021

Background

Transthoracic echocardiography (TTE) is commonly used after pediatric cardiac surgery to monitor cardiac function and adequacy of surgery; however it depends on the availability of good echo window and operator skill [1]. Transpulmonary thermodilution (TPTD) is feasible along with calibrated continuous cardiac output measurement in children but seldom used due to cost and the need for a specialized catheter [2].

We hypothesized that TTE would be as good as TPTD, but limited in feasibility following pediatric cardiac surgery. Hence, the concordance, agreement as well as feasibility and trending of cardiac output monitoring by TTE was compared against a reference TPTD method in real-world usage in children after congenital heart surgery.

Methods

This was a secondary analysis of data from a previously registered and conducted study in our unit. TPTD monitoring was instituted in children undergoing congenital heart disease repair on cardiopulmonary bypass with a 3F femoral arterial cannula and a central venous injectate temperature sensor.

Cardiac output was also measured by transthoracic echocardiography by measurement of the left ventricular outflow tract (LVOT) diameter, LVOT velocity time integral (VTI) and the heart rate as previously described [3,4]. Measurements were taken after arrival in the ICU, and every 12 hours till after extubation. Correlation, Bland-Altman analysis and polar analysis was done for cardiac output measured by TPTD and TTE.

Results

TTE and TPTD measurements of cardiac output correlated well (Pearson's correlation coefficient 0.94; 95% CI 0.90–0.96) (Fig. 1A). Bland Altman analysis showed a mean bias of 0.15 l/min and upper and lower limits of agreement of 0.81 and −0.51 l/min respectively (Fig. 1B). Cardiac output measurement by TTE was possible in 72 instances while TPTD allowed measurement in all 113 instances. Hence, TTE was not feasible in 41 instances across 14 patients, including 19 instances in acyanotic and 22 instances in cyanotic patients. Polar analysis revealed acceptable trending.

Conclusions

TTE derived cardiac output demonstrated good correlation, minimal bias and narrow limits of agreement versus TPTD, and was feasible in most cases. This suggests TTE is an acceptable cardiac output measurement modality post pediatric cardiac surgery, as in adults [5]. TPTD-based continuous cardiac output monitoring might have a complementary role in pediatric cardiac critical care, particularly in high risk cases.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Institutional Special Research Grant from Postgraduate Institute of Medical Education and Research, Chandigarh, India. Figure 1
Impact of high cardiovascular risk on hospital mortality in patients admitted to intensive care by COVID-19
Authors: Gomes B F O , Silva T M B , Dutra G P , Azevedo A S , Pereira D F P , Peres L S , Nascimento J H P , Petriz J L F , Carmo Junior P R , Pereira B B , Oliveira G M M
Published: October 2021

Background

Some studies have shown a higher prevalence of deaths in patients with cardiovascular risk factors (CRF) during hospitalization for COVID-19. The impact of high cardiovascular risk on hospital mortality has not been evaluated.

Methods

Retrospective study with patients admitted to intensive care and confirmed diagnosis of COVID-19 by RT-PCR and with at least one measurement of troponin during hospitalization. The criteria for defining a high cardiovascular risk patient (HCR) were: history of established cardiovascular disease (myocardial infarction, stroke, or peripheral arterial disease), diabetes, chronic kidney disease with clearance <60ml/min, or presence of, at least, 3 risk factors (hypertension, smoking, dyslipidemia or age>65 years). The population was divided into 4 groups according to the presence of HCR and elevated troponin. Mortality was assessed using the chi-square method, according to the number of CRF, and was assessed in the 4 predetermined groups through logistic regression adjusted for severity (using the SAPS3 score).

Results

After evaluating 271 admissions during the study period, 236 patients were included for analysis. The mean age was 61.14±16.2 years, with 63.1% men. The prevalence of hypertension was 55.5% and diabetes, 33.1%. 47.4% of the patients had HCR. There was a significant increase in mortality as the number of risk factors increased (no CRF: 5.9%; 1 CRF: 17.5%; 2 CRF: 32.2% and ≥3 CRF: 41.2%; p=0.001). In logistic regression, patients with high cardiovascular risk and high troponin had a higher incidence of hospital mortality (OR 40.38; 95% CI 11.78–138.39). Patients without high cardiovascular risk, but with high troponin also showed a significant association with the primary outcome (OR 16.7; 95% CI 4.45–62.74). In contrast, patients with high cardiovascular risk and normal troponin were not at higher risk of death (OR 2.06; 95% CI 0.56–7.56).

Conclusion

In patients admitted to intensive care by COVID-19, the high cardiovascular risk impacts on hospital mortality only in patients who presented an increase in troponin levels.

Funding Acknowledgement

Type of funding sources: None.
Increased risk of non-hematological cancer in young patients with aortic stenosis: a retrospective cohort study
Authors: Shiran A , Bental T , Shapira Y , Schwartzenberg S , Sagie A , Vaturi M , Adawi S , Fuks A , Aronheim A , Saliba W
Published: October 2021

Background

We have previously reported an increased risk for non-hematological malignancies in young patients with moderate or severe aortic stenosis (AS) (1). These findings were the result of a post-hoc analysis from a large echocardiography database and needed verification.

Purpose

To determine, using a different study population, whether young patients with AS are at increased risk for cancer.

Methods

A large echocardiographic database was used to identify patients (age≥20 years) with moderate or severe AS (study group) and patients without aortic stenosis (comparative group). The new occurrence of non-hematological malignancies was determined after the index date (first echo with moderate or severe AS or first recorded echo in the control group).

Results

The final study group included 7,013 patients with AS and 98,884 without AS. During a median follow-up of 6.9 years (3.0–11.1) there were 10,705 new cases of non-hematological cancer. The crude incidence rate of cancer was higher in AS compared to non-AS patients (22.3 vs. 13.7 per 1,000 patient-year, crude HR 1.58 (95% CI 1.46–1.71). After adjustment for relevant covariates, there was no difference between groups (HR 0.93, 95% CI 0.86–1.01). Only patients in the lowest age quartile (20–49.7 years), had an increased adjusted risk of cancer (HR 1.91, 95% CI 1.08–3.39). The HR for the risk of cancer in AS was inversely proportional to age (P<0.001 for the interaction between AS and age) (Figure 1).

Conclusion

Young patients with moderate or severe AS are at increased risk for cancer. Cancer surveillance should be considered for young patients with AS.

Funding Acknowledgement

Type of funding sources: None. Figure 1