bluuebunny/crossref_metadata_2025 huggingface dataset:
Tailoring molecular termination for thermally stable perovskite solar cells
Authors: Zhang Xiao , Ma Sai , You Jingbi , Bai Yang , Chen Qi
Published: November 2021

Interfacial engineering has made an outstanding contribution to the development of high-efficiency perovskite solar cells (PSCs). Here, we introduce an effective interface passivation strategy via methoxysilane molecules with different terminal groups. The power conversion efficiency (PCE) has increased from 20.97% to 21.97% after introducing a 3-isocyanatopropyltrimethoxy silane (IPTMS) molecule with carbonyl group, while a trimethoxy[3-(phenylamino)propyl] silane (PAPMS) molecule containing aniline group deteriorates the photovoltaic performance as a consequence of decreased open circuit voltage. The improved performance after IPTMS treatment is ascribed to the suppression of non-radiative recombination and enhancement of carrier transportation. In addition, the devices with carbonyl group modification exhibit outstanding thermal stability, which maintain 90% of its initial PCE after 1500 h exposure. This work provides a guideline for the design of passivation molecules aiming to deliver the efficiency and thermal stability simultaneously.
GaN-based blue laser diode with 6.0 W of output power under continuous-wave operation at room temperature
Authors: Liang Feng , Zhao Degang , Liu Zongshun , Chen Ping , Yang Jing , Duan Lihong , Shi Yongsheng , Wang Hai
Published: November 2021

In this work, we reported the room-temperature continuous-wave operation of 6.0 W GaN-based blue laser diode (LD), and its stimulated emission wavelength is around 442 nm. The GaN-based high power blue LD is grown on a c-plane GaN substrate by metal organic chemical vapor deposition (MOCVD), and the width and length of the ridge waveguide structure are 30 and 1200 μm, respectively. The threshold current is about 400 mA, and corresponding threshold current density is 1.1 kA/cm2.
Investigation of lateral spreading current in the 4H-SiC Schottky barrier diode chip
Authors: Wang Xi , Zhong Yiwen , Pu Hongbin , Hu Jichao , Feng Xianfeng , Yang Guowen
Published: November 2021

Lateral current spreading in the 4H-SiC Schottky barrier diode (SBD) chip is investigated. The 4H-SiC SBD chips with the same vertical parameters are simulated and fabricated. The results indicate that there is a fixed spreading resistance at on-state in current spreading region for a specific chip. The linear specific spreading resistance at the on-state is calculated to be 8.6 Ω/cm in the fabricated chips. The proportion of the lateral spreading current in total forward current (P
sp) is related to anode voltage and the chip area. P
sp is increased with the increase in the anode voltage during initial on-state and then tends to a stable value. The stable values of P
sp of the two fabricated chips are 32% and 54%. Combined with theoretical analysis, the proportion of the terminal region and scribing trench in a whole chip (K
sp) is also calculated and compared with P
sp. The K
sp values of the two fabricated chips are calculated to be 31.94% and 57.75%. The values of K
sp and P
sp are close with each other in a specific chip. The calculated K
sp can be used to predict that when the chip area of SiC SBD becomes larger than 0.5 cm2, the value of P
sp would be lower than 10%.
Energy confinement in the spherical tokamak Globus-M2 with a toroidal magnetic field reaching 0.8 T
Authors: Kurskiev G.S. , Gusev V.K. , Sakharov N.V. , Petrov Yu.V. , Bakharev N.N. , Balachenkov I.M. , Bazhenov A.N. , Chernyshev F.V. , Khromov N.A. , Kiselev E.O. , Krikunov S.V. , Minaev V.B. , Miroshnikov I.V. , Novokhatskii A.N. , Zhiltsov N.S. , Mukhin E.E. , Patrov M.I. , Shulyatiev K.D. , Shchegolev P.B. , Skrekel O.M. , Telnova A.Yu. , Tkachenko E.E. , Tukhmeneva E.A. , Tokarev V.A. , Tolstyakov S.Yu. , Varfolomeev V.I. , Voronin A.V. , Goryainov V.Yu. , Bulanin V.V. , Petrov A.V. , Ponomarenko A.M. , Yashin A.Yu. , Kavin A.A. , Zhilin E.G. , Solovey V.A.
Published: November 2021

The work presents the results of the energy confinement study carried out on the compact spherical tokamak Globus-M2 with a toroidal magnetic field as high as 0.8 T. A reproducible and stable discharge was obtained with the average plasma density (5–10) × 1019 m−3. Despite the increase in the magnetic field, the neutral beam injection (NBI) led to clear and reproducible transition to the H-mode accompanied by a decrease in the turbulence level at the plasma edge. NBI allowed effectively heat the plasma: electron and ion temperatures in the plasma core exceeded 1 keV. Compared to the previous experiments carried out with a toroidal magnetic field as high as 0.4 T plasma total stored energy was increased by a factor of 4. The main reason or this phenomenon is a strong dependence of the energy confinement time on the toroidal magnetic field in the spherical tokamak. It was experimentally confirmed that such kind of dependence is valid for ST with magnetic field up to 0.8 T. It has also been shown that the enhancement of the energy confinement in Globus-M2 with collisionality decrease is associated with an improvement of both electron and ion thermal insulation.
The impact of the intensity of selective sanitary cutting in oak forests on the defeat of the pedunculated oak (Quercus Robur L.) trees by powdery mildew
Authors: Tsaralunga V , Tsaralunga A , Yakovenko N , Gridnev Yu
Published: November 2021

The article assesses the impact of the intensity of selective sanitary cutting in oak forests on the defeat of oak trees by powdery mildew. The research methodology included visual estimation and detailed inspection of oak plantations. On their basis, the species composition of pathogens was identified, the degree of crown desiccation from a complex of factors and leaf infestation with powdery mildew and necrotic spots was assessed. The dispersive analysis was applied for data processing. The analysis of the long-term survey of the plots passed by selective sanitary cutting shows that the degree of damage to oak trees by powdery mildew on permanent test areas practically does not depend directly from selective sanitary cutting, in general, and from their intensity, in particular. The dynamics of the damage degree of the oak trees by powdery mildew changed almost synchronously in all test areas and in the control area. The results can be used in the practice of the Voronezh region forestry enterprises when carrying out forest pathology surveys.
Guiding and routing surface plasmons with transformation-invariant metamaterials
Authors: Huang Yao , Zhang Jingjing , Qiang Bo , Xu Zhengji , Wang Qijie , Luo Yu
Published: November 2021

Rough metallic surfaces cause severe scattering to surface plasmon polaritons (SPPs), thereby limiting SPP transmission efficiency. Here, we propose a general scheme to design ultracompact plasmonic routers that can confine and guide SPPs on an arbitrarily shaped rough surface. Our strategy makes use of recently proposed transformation-invariant metamaterials (TIMs). To illustrate the advantages of this approach, we perform finite-element simulations, showing that the performance of the designed surface wave router is robust against the change in thickness. As a result, a λ/6 thick TIM layer can significantly suppress scattering from arbitrarily shaped metallic bumps or crevices. We also give a blueprint to implement such ultracompact surface wave routers based on periodic metal/epsilon-near-zero material stackings.
Variational quantum algorithms for trace distance and fidelity estimation
Authors: Chen Ranyiliu , Song Zhixin , Zhao Xuanqiang , Wang Xin
Published: November 2021

Estimating the difference between quantum data is crucial in quantum computing. However, as typical characterizations of quantum data similarity, the trace distance and quantum fidelity are believed to be exponentially-hard to evaluate in general. In this work, we introduce hybrid quantum–classical algorithms for these two distance measures on near-term quantum devices where no assumption of input state is required. First, we introduce the variational trace distance estimation (VTDE) algorithm. We in particular provide the technique to extract the desired spectrum information of any Hermitian matrix by local measurement. A novel variational algorithm for trace distance estimation is then derived from this technique, with the assistance of a single ancillary qubit. Notably, VTDE could avoid the barren plateau issue with logarithmic depth circuits due to a local cost function. Second, we introduce the variational fidelity estimation algorithm. We combine Uhlmann’s theorem and the freedom in purification to translate the estimation task into an optimization problem over a unitary on an ancillary system with fixed purified inputs. We then provide a purification subroutine to complete the translation. Both algorithms are verified by numerical simulations and experimental implementations, exhibiting high accuracy for randomly generated mixed states.
Association Between Maternal Adverse Childhood Experiences and NeonatalSCG5DNA Methylation—Effect Modification by Prenatal Home Visiting
Authors: Folger Alonzo T , Nidey Nichole , Ding Lili , Ji Hong , Yolton Kimberly , Ammerman Robert T , Bowers Katherine A
Published: November 2021

Maternal childhood adversity and trauma may elicit biological changes that impact the next generation through epigenetic responses measured in DNA methylation (DNAm). These epigenetic associations could be modified by the early postnatal environment through protective factors, such as early childhood home visiting (HV) programs that aim to mitigate deleterious intergenerational effects of adversity. In a cohort of 53 mother-child pairs recruited in 2015–2016 for the Pregnancy and Infant Development Study (Cincinnati, Ohio), we examined the association between maternal adverse childhood experiences (ACEs) and neonatal DNAm in the secretogranin V gene (SCG5), which is important in neuroendocrine function. We examined prenatal HV as an effect modifier. Mothers completed a questionnaire on ACEs during pregnancy, and infant buccal samples were collected 1 month postpartum. Multivariable linear regression was used to examine the association between maternal ACEs and neonatal DNAm expressed as M-values averaged across 4 cytosine-phosphate-guanine dinucleotide sites. A higher number of maternal ACEs (>3) was associated with a 5.79–percentage-point lower offspring DNAm (95% confidence interval: −10.44, −1.14), and the association was modified by the number of home visits received during pregnancy. In a population of at-risk mother-child dyads, preliminary evidence suggests that maternal ACEs have a relationship with offspring SCG5 DNAm that differs by the amount of prenatal HV.
Effects of Classroom Instruction on the Development of L2 Interactional Resource for Joint Stance Taking: Use of Japanese Interactional ParticleYoin Spontaneous Peer Conversation
Authors: Hoshi Saori
Published: November 2021

The present study examines the development of L2 interactional competence (Hall et al. 2011) focusing on JFL learners’ use of a Japanese interactional particle yo in spontaneous conversation with native speaker peers. More specifically, this study aims to investigate the instructional effectiveness for the learners’ ability to use the particle yo as an epistemic marker for joint stance taking (Morita 2015, 2018) in interaction. The study implements pragmatics-focused instruction, incorporating awareness-raising and conversational activities, in a third-semester Japanese class for one semester. Qualitative analysis focused on the learners’ ability to deploy yo in activity-relevant participation including an assessment activity (Goodwin and Goodwin 1992) and evidence for their use of yo that extends beyond the instructional content. The findings revealed that the instructed learners increasingly became able to use yo in various stance-indexing activities such as assessment, news telling, highlighting epistemic gap between participants toward the ongoing topic. Learners’ emerging interactional competence reflects their ability to use yo as an interactional resource for co-constructing stance and intersubjectivity as they engage in conversation with NS peers.
Procedural Justice, Compliance and The ‘Upstanding Citizen’: A Study of Community Protection Notices
Authors: Black Alex , Heap Vicky
Published: November 2021

This article explores procedural justice and motivational postures theories through the lens of Community Protection Notices (CPN), civil measures used to tackle anti-social behaviour in England and Wales. Through a qualitative study of CPN recipients, this article adds to our understanding of the social identity aspect of procedural justice theory by examining the impact on self-identified ‘upstanding citizens’ issued with a CPN for behaviours that they disputed on moral grounds. In order to renegotiate this anti-social label, participants explored other social categories to create distance between themselves and the authorities and challenged their role as representatives of the ‘law-abiding majority’. Ultimately, participants felt ‘compelled’ to comply with the requirements of their CPN, which in turn damaged perceptions of legitimacy.
The neuroradiology of progressive multifocal leukoencephalopathy: a clinical trial perspective
Authors: Baldassari Laura E , Wattjes Mike P , Cortese Irene C M , Gass Achim , Metz Imke , Yousry Tarek , Reich Daniel S , Richert Nancy
Published: November 2021

Progressive multifocal leukoencephalopathy (PML) is an opportunistic infection of the CNS caused by the JC virus, which infects white and grey matter cells and leads to irreversible demyelination and neuroaxonal damage. Brain MRI, in addition to the clinical presentation and demonstration of JC virus DNA either in the CSF or by histopathology, is an important tool in the detection of PML. In clinical practice, standard MRI pulse sequences are utilized for screening, diagnosis and monitoring of PML, but validated imaging-based outcome measures for use in prospective, interventional clinical trials for PML have yet to be established. We review the existing literature regarding the use of MRI and PET in PML and discuss the implications of PML histopathology for neuroradiology. MRI not only demonstrates the localization and extent of PML lesions, but also mirrors the tissue destruction, ongoing viral spread, and resulting inflammation. Finally, we explore the potential for imaging measures to serve as an outcome in PML clinical trials and provide recommendations for current and future imaging outcome measure development in this area.
Irreversible specialization for speech perception in early international adoptees
Authors: Norrman Gunnar , Bylund Emanuel , Thierry Guillaume
Published: November 2021

In early childhood, the human brain goes through a period of tuning to native speech sounds but retains remarkable flexibility, allowing the learning of new languages throughout life. However, little is known about the stability over time of early neural specialization for speech and its influence on the formation of novel language representations. Here, we provide evidence that early international adoptees, who lose contact with their native language environment after adoption, retain enhanced sensitivity to a native lexical tone contrast more than 15 years after being adopted to Sweden from China, in the absence of any pretest familiarization with the stimuli. Changes in oscillatory brain activity showed how adoptees resort to inhibiting the processing of defunct phonological representations, rather than forgetting or replacing them with new ones. Furthermore, neurophysiological responses to native and nonnative contrasts were not negatively correlated, suggesting that native language retention does not interfere with the acquisition of adoptive phonology acquisition. These results suggest that early language experience provides strikingly resilient specialization for speech which is compensated for through inhibitory control mechanisms as learning conditions change later in life.
Left atrial function in male veteran endurance athletes with paroxysmal atrial fibrillation
Authors: Sørensen Eivind , Myrstad Marius , Solberg Magnar Gangås , Øie Erik , Tveit Arnljot , Aarønæs Marit
Published: November 2021

Aims

To assess left atrial (LA) function in sinus rhythm in veteran athletes with a history of paroxysmal atrial fibrillation (AF) exposed to prolonged endurance exercise compared with veteran athletes without AF and controls with and without paroxysmal AF from a non-athletic population.

Methods and results

Three hundred and two male participants from four groups, veteran recreational skiers with paroxysmal AF (n = 62), veteran skiers without AF (n = 89), and controls from a non-athletic population with (n = 62) and without paroxysmal AF (n = 89) underwent an echocardiographic examination in sinus rhythm to evaluate LA anatomy and function. The skiers (mean age 70.8±6.7 years) reported an average exposure to regular endurance exercise for 40–50 years. LA maximum and minimum volumes were larger in skiers (P < 0.001). LA volumes differed within the athletic and non-athletic groups with larger volumes in the AF groups ( P < 0.001). We observed a considerable overlap in LA volumes among non-athletes with AF and athletes without AF. LA reservoir strain (33.6% ± 4.8% vs. 28.3% ± 6.7% P < 0.001) and contractile strain (18.3% ± 4.0% vs. 15.0% ± 5.2% P < 0.001) were lower in both AF groups regardless of athletic status. LA reservoir strain was superior to volumetric measurements at identifying participants with AF (area under the curve 0.740 ±0.041).

Conclusion

Male veteran athletes had significantly larger LA volumes than non-athletes. In contrast, LA strain values were similar in athletes and non-athletes with paroxysmal AF, and significantly lower than in subjects without AF.
Multi-modality imaging assessment of native valvular regurgitation: an EACVI and ESC council of valvular heart disease position paper
Authors: Lancellotti Patrizio , Pibarot Philippe , Chambers John , La Canna Giovanni , Pepi Mauro , Dulgheru Raluca , Dweck Mark , Delgado Victoria , Garbi Madalina , Vannan Mani A , Montaigne David , Badano Luigi , Maurovich-Horvat Pal , Pontone Gianluca , Vahanian Alec , Donal Erwan , Cosyns Bernard ,   the Scientific Document Committee of the European Association of Cardiovascular Imaging
Published: November 2021

Valvular regurgitation represents an important cause of cardiovascular morbidity and mortality. Imaging is pivotal in the evaluation of native valve regurgitation and echocardiography is the primary imaging modality for this purpose. The imaging assessment of valvular regurgitation should integrate quantification of the regurgitation, assessment of the valve anatomy and function, and the consequences of valvular disease on cardiac chambers. In clinical practice, the management of patients with valvular regurgitation largely relies on the results of imaging. It is crucial to provide standards that aim at establishing a baseline list of measurements to be performed when assessing native valve regurgitation. The present document aims to present clinical guidance for the multi-modality imaging assessment of native valvular regurgitation.
Aneurysm growth, survival, and quality of life in untreated thoracic aortic aneurysms: the effective treatments for thoracic aortic aneurysms study
Authors: Sharples Linda , Sastry Priya , Freeman Carol , Bicknell Colin , Chiu Yi Da , Vallabhaneni Srinivasa Rao , Cook Andrew , Gray Joanne , McCarthy Andrew , McMeekin Peter , Vale Luke , Large Stephen
Published: November 2021

Aims

To observe, describe, and evaluate management and timing of intervention for patients with untreated thoracic aortic aneurysms.

Methods and results

Prospective study of UK National Health Service (NHS) patients aged ≥18 years, with new/existing arch or descending thoracic aortic aneurysms of ≥4 cm diameter, followed up until death, intervention, withdrawal, or July 2019. Outcomes were aneurysm growth, survival, quality of life (using the EQ-5D-5L utility index), and hospital admissions. Between 2014 and 2018, 886 patients were recruited from 30 NHS vascular/cardiothoracic units. Maximum aneurysm diameter was in the descending aorta in 725 (82%) patients, growing at 0.2 cm (0.17–0.24) per year. Aneurysms of ≥4 cm in the arch increased by 0.07 cm (0.02–0.12) per year. Baseline diameter was related to age and comorbidities, and no clinical correlates of growth were found. During follow-up, 129 patients died, 64 from aneurysm-related events. Adjusting for age, sex, and New York Heart Association dyspnoea index, risk of death increased with aneurysm size at baseline [hazard ratio (HR): 1.88 (95% confidence interval: 1.64–2.16) per cm, P < 0.001] and with growth [HR: 2.02 (1.70–2.41) per cm, P < 0.001]. Hospital admissions increased with aneurysm size [relative risk: 1.21 (1.05–1.38) per cm, P = 0.008]. Quality of life decreased annually for each 10-year increase in age [–0.013 (–0.019 to –0.007), P < 0.001] and for current smoking [–0.043 (–0.064 to –0.023), P = 0.004]. Aneurysm size was not associated with change in quality of life.

Conclusion

International guidelines should consider increasing monitoring intervals to 12 months for small aneurysms and increasing intervention thresholds. Individualized decisions about surveillance/intervention should consider age, sex, size, growth, patient characteristics, and surgical risk.
Detection of self-harm and suicidal ideation in emergency department triage notes
Authors: Rozova Vlada , Witt Katrina , Robinson Jo , Li Yan , Verspoor Karin
Published: November 2021

Objective

Accurate identification of self-harm presentations to Emergency Departments (ED) can lead to more timely mental health support, aid in understanding the burden of suicidal intent in a population, and support impact evaluation of public health initiatives related to suicide prevention. Given lack of manual self-harm reporting in ED, we aim to develop an automated system for the detection of self-harm presentations directly from ED triage notes.

Materials and methods

We frame this as supervised classification using natural language processing (NLP), utilizing a large data set of 477 627 free-text triage notes from ED presentations in 2012–2018 to The Royal Melbourne Hospital, Australia. The data were highly imbalanced, with only 1.4% of triage notes relating to self-harm. We explored various preprocessing techniques, including spelling correction, negation detection, bigram replacement, and clinical concept recognition, and several machine learning methods.

Results

Our results show that machine learning methods dramatically outperform keyword-based methods. We achieved the best results with a calibrated Gradient Boosting model, showing 90% Precision and 90% Recall (PR-AUC 0.87) on blind test data. Prospective validation of the model achieves similar results (88% Precision; 89% Recall).

Discussion

ED notes are noisy texts, and simple token-based models work best. Negation detection and concept recognition did not change the results while bigram replacement significantly impaired model performance.

Conclusion

This first NLP-based classifier for self-harm in ED notes has practical value for identifying patients who would benefit from mental health follow-up in ED, and for supporting surveillance of self-harm and suicide prevention efforts in the population.
Determination of Gliadin as a Measure of Gluten in Food by R5 Sandwich ELISA RIDASCREEN® Gliadin Matrix Extension: Collaborative Study 2012.01
Authors: Lacorn Markus , Dubois Tina , Weiss Thomas , Zimmermann Lisa , Schinabeck Teresa-Maria , Loos-Theisen Simone , Scherf Katharina
Published: November 2021

Background

According to Codex Alimentarius, food products containing less than 20 mg/kg gluten can be labeled as “gluten-free.” Since 2002, the R5 antibody method allowed determination of gluten levels and led to a huge improvement of products available to celiac disease (CD) patients.

Method

The R5-containing test kit RIDASCREEN® Gliadin in combination with the cocktail solution was endorsed as Codex Type 1 Method in 2006 based on a collaborative study with corn-based bread, rice-based dough, wheat starches, rice, and corn flour. In 2012, the method was approved as First Action Official MethodSM2012.01 with an “in foods” claim. For Final Action in 2016, the matrix claim was reduced to rice- and corn-based matrixes.

Objective

Therefore, R-Biopharm decided to start a collaborative study to demonstrate the wide applicability of Official Method 2012.01 for the quantitative analysis of gliadin in soy, starches, pseudo cereals, legumes, spices, juice, nut nougat crème, cream cheese, pesto, meat, vegetarian meat alternative, cookies, dessert, cake, fish, bread, candies, and potatoes. Materials for incurring were the MoniQA wheat flour and the PWG gliadin preparation.

Results

Gliadin levels ranged from 3.4 up to 27.4 mg gliadin per kg. The results of the collaborative study with 14 participating laboratories showed recoveries ranging from 80 to 130%. Relative reproducibility standard deviations for contaminated samples were between 9.8 and 27.7%.

Conclusions

The collaborative study results confirmed that the method is accurate and suitable to measure gliadin in important gluten-free food matrixes.

Highlights

The title and applicability statement of Official Method 2012.01 were changed as proposed.
Prophylactic subtotal colectomy in a patient with an AXIN2 mutation
Authors: Vierra Benjamin M
Published: November 2021

A number of genetic syndromes that predispose patients to colon cancer have been well described, allowing for improved surveillance, diagnosis and treatment. However, other syndromes likely exist but have yet to be thoroughly characterized. I report the case of a 50-year-old woman who was found to have over 50 polyps on routine screening colonoscopy. Genetic sequencing revealed a mutation in Axin2, a rare gene implicated in oligodontia-colorectal cancer syndrome. It was later found that the patient lacks several permanent teeth, as does her mother, who also had a history of multiple colonic polyps. Given the rarity of Axin2 mutations, there are no guidelines for management of such patients. This highlights the importance of a thorough review of system when screening for colon cancer as well as documenting cases of Axin2 mutations to create management guidelines for these patients.
Mass, morphing, metallicities: the evolution of infalling high velocity clouds
Authors: Heitsch F , Marchal A , Miville-Deschênes M-A , Shull J M , Fox A J
Published: November 2021

We revisit the reliability of metallicity estimates of high velocity clouds with the help of hydrodynamical simulations. We quantify the effect of accretion and viewing angle on metallicity estimates derived from absorption lines. Model parameters are chosen to provide strong lower limits on cloud contamination by ambient gas. Consistent with previous results, a cloud traveling through a stratified halo is contaminated by ambient material to the point that <10 per cent of its mass in neutral hydrogen consists of original cloud material. Contamination progresses nearly linearly with time, and it increases from head to tail. Therefore, metallicity estimates will depend on the evolutionary state of the cloud, and on position. While metallicities change with time by more than a factor of 10, well beyond observational uncertainties, most lines-of-sight range only within those uncertainties at any given time over all positions. Metallicity estimates vary with the cloud’s inclination angle within observational uncertainties. The cloud survives the infall through the halo because ambient gas continuously condenses and cools in the cloud’s wake and thus appears in the neutral phase. Therefore, the cloud observed at any fixed time is not a well-defined structure across time, since material gets constantly replaced. The thermal phases of the cloud are largely determined by the ambient pressure. Internal cloud dynamics evolve from drag gradients caused by shear instabilities, to complex patterns due to ram-pressure shielding, leading to a peloton effect, in which initially lagging gas can catch up to and even overtake the head of the cloud.
Implications of spicule activity on coronal loop heating and catastrophic cooling
Authors: Nived V N , Scullion E , Doyle J G , Susino R , Antolin P , Spadaro D , Sasso C , Sahin S , Mathioudakis M
Published: November 2021

We report on the properties of coronal loop foot-point heating with observations at the highest resolution, from the CRisp Imaging Spectro-Polarimeter located at the Swedish 1-m Solar Telescope and co-aligned NASA Solar Dynamics Observatory observations, of Type II spicules in the chromosphere and their signatures in the extreme ultraviolet (EUV) corona. Here, we address one important issue, as to why there is not always a one-to-one correspondence, between Type II spicules and hot coronal plasma signatures, i.e. beyond TR temperatures. We do not detect any difference in their spectral properties in a quiet Sun region compared to a region dominated by coronal loops. On the other hand, the number density close to the foot-points in the active region is found to be an order of magnitude higher than in the quiet Sun case. A differential emission measure analysis reveals a peak at ∼5 × 105 K of the order of 1022 cm−5 K−1. Using this result as a constraint, we conduct numerical simulations and show that with an energy input of 1.25 × 1024 erg (corresponding to ∼10 RBEs contributing to the burst) we manage to reproduce the observation very closely. However, simulation runs with lower thermal energy input do not reproduce the synthetic AIA 171 Å signatures, indicating that there is a critical number of spicules required in order to account for the AIA 171 Å signatures in the simulation. Furthermore, the higher energy (1.25 × 1024 erg) simulations reproduce catastrophic cooling with a cycle duration of ∼5 h, matching a periodicity we observe in the EUV observations.
Theoretical lifetimes and Stark broadening parameters for visible-infrared spectral lines of V i in Arcturus
Authors: Isidoro-García L , de Andrés-García I , Moreno-Conde D , Colón C
Published: November 2021

In this work, the Stark broadening parameters (line widths and line shifts) of 114 visible-infrared spectral lines of neutral vanadium (V i) have been calculated. As in a previous work devoted to their spectral lines in the Ultraviolet (UV)-blue range, these parameters have been calculated using the Griem’s semi-empirical formula and the Cowan code for the calculation of the necessary matrix elements. In addition to their astrophysical interest (the majority of the analysed spectral lines have been detected in Arcturus, in the metal-poor star HD 84937 and in the Sun), these parameters are also relevant in the analysis of plasmas generated in industrial processes in Laser Shock Processes treatments of Ti-6Al-4V type samples.
Using a quadruplet codon to expand the genetic code of an animal
Authors: Xi Zhiyan , Davis Lloyd , Baxter Kieran , Tynan Ailish , Goutou Angeliki , Greiss Sebastian
Published: November 2021

Genetic code expansion in multicellular organisms is currently limited to the use of repurposed amber stop codons. Here, we introduce a system for the use of quadruplet codons to direct incorporation of non-canonical amino acids in vivo in an animal, the nematode worm Caenorhabditis elegans. We develop hybrid pyrrolysyl tRNA variants to incorporate non-canonical amino acids in response to the quadruplet codon UAGA. We demonstrate the efficiency of the quadruplet decoding system by incorporating photocaged amino acids into two proteins widely used as genetic tools. We use photocaged lysine to express photocaged Cre recombinase for the optical control of gene expression and photocaged cysteine to express photo-activatable caspase for light inducible cell ablation. Our approach will facilitate the routine adoption of quadruplet decoding for genetic code expansion in eukaryotic cells and multicellular organisms.
Negative feedback forDARS2–Fis complex by ATP–DnaA supports the cell cycle-coordinated regulation for chromosome replication
Authors: Miyoshi Kenya , Tatsumoto Yuka , Ozaki Shogo , Katayama Tsutomu
Published: November 2021

In Escherichia coli, the replication initiator DnaA oscillates between an ATP- and an ADP-bound state in a cell cycle-dependent manner, supporting regulation for chromosome replication. ATP–DnaA cooperatively assembles on the replication origin using clusters of low-affinity DnaA-binding sites. After initiation, DnaA-bound ATP is hydrolyzed, producing initiation-inactive ADP–DnaA. For the next round of initiation, ADP–DnaA binds to the chromosomal locus DARS2, which promotes the release of ADP, yielding the apo-DnaA to regain the initiation activity through ATP binding. This DnaA reactivation by DARS2 depends on site-specific binding of IHF (integration host factor) and Fis proteins and IHF binding to DARS2 occurs specifically during pre-initiation. Here, we reveal that Fis binds to an essential region in DARS2 specifically during pre-initiation. Further analyses demonstrate that ATP–DnaA, but not ADP–DnaA, oligomerizes on a cluster of low-affinity DnaA-binding sites overlapping the Fis-binding region, which competitively inhibits Fis binding and hence the DARS2 activity. DiaA (DnaA initiator-associating protein) stimulating ATP–DnaA assembly enhances the dissociation of Fis. These observations lead to a negative feedback model where the activity of DARS2 is repressed around the time of initiation by the elevated ATP–DnaA level and is stimulated following initiation when the ATP–DnaA level is reduced.
Structure of CRL2Lrr1, the E3 ubiquitin ligase that promotes DNA replication termination in vertebrates
Authors: Zhou Haixia , Zaher Manal S , Walter Johannes C , Brown Alan
Published: November 2021

When vertebrate replisomes from neighboring origins converge, the Mcm7 subunit of the replicative helicase, CMG, is ubiquitylated by the E3 ubiquitin ligase, CRL2Lrr1. Polyubiquitylated CMG is then disassembled by the p97 ATPase, leading to replication termination. To avoid premature replisome disassembly, CRL2Lrr1 is only recruited to CMGs after they converge, but the underlying mechanism is unclear. Here, we use cryogenic electron microscopy to determine structures of recombinant Xenopus laevis CRL2Lrr1 with and without neddylation. The structures reveal that CRL2Lrr1 adopts an unusually open architecture, in which the putative substrate-recognition subunit, Lrr1, is located far from the catalytic module that catalyzes ubiquitin transfer. We further demonstrate that a predicted, flexible pleckstrin homology domain at the N-terminus of Lrr1 is essential to target CRL2Lrr1 to terminated CMGs. We propose a hypothetical model that explains how CRL2Lrr1’s catalytic module is positioned next to the ubiquitylation site on Mcm7, and why CRL2Lrr1 binds CMG only after replisomes converge.
Firm dynamics by age and size classes and the choice of size measure
Authors: Giannoulakis Stelios , Sakellaris Plutarchos
Published: November 2021

The relationship of firm size and age to its growth and survival differs depending on whether the size is measured by sales or employment. Using a large dataset of Greek firms over the period 1999–2014, we find the following patterns. Controlling for age, there is a strong negative growth–size relationship when measuring size with sales, but a strong positive one when measuring size with employment. Controlling for size, there is a positive monotonic survival–age relationship when measuring size with sales, whereas survival is negatively related with age for young firms when we measure size with employment. Our results indicate that public policies aimed at supporting SMEs should be specialized to the employment scale and the sales scale of enterprises, separately.
La prise en charge des exacerbations aiguës de l’asthme chez les enfants
Authors: Trottier Evelyne D , Chan Kevin , Allain Dominic , Chauvin-Kimoff Laurel
Published: November 2021

Les enfants et les adolescents atteints d’exacerbations aiguës de l’asthme se rendent souvent à l’urgence à cause de signes de détresse respiratoire. Les épisodes les plus graves ont un potentiel mortel. Pour que les traitements soient efficaces, le patient doit faire l’objet d’une évaluation exacte et rapide de la gravité de la crise d’asthme. Le présent document de principes traite de l’évaluation, de la prise en charge et de la disposition des patients pédiatriques ayant un diagnostic connu d’asthme qui consultent à cause d’une exacerbation aiguë. Les directives portent sur l’évaluation de la gravité de l’asthme, les considérations thérapeutiques, le plan de congé approprié, le suivi et la prescription de corticostéroïdes inhalés pour éviter de nouvelles exacerbations et limiter la morbidité chronique.
Piriformospora indica recruits host-derived putrescine for growth promotion in plants
Authors: Kundu Anish , Mishra Shruti , Kundu Pritha , Jogawat Abhimanyu , Vadassery Jyothilakshmi
Published: November 2021

Growth promotion induced by the endosymbiont Piriformospora indica has been observed in various plants; however, except growth phytohormones, specific functional metabolites involved in P. indica-mediated growth promotion are unknown. Here, we used a gas chromatography-mass spectrometry-based untargeted metabolite analysis to identify tomato (Solanum lycopersicum) metabolites whose levels were altered during P. indica-mediated growth promotion. Metabolomic multivariate analysis revealed several primary metabolites with altered levels, with putrescine (Put) induced most significantly in roots during the interaction. Further, our results indicated that P. indica modulates the arginine decarboxylase (ADC)-mediated Put biosynthesis pathway via induction of SlADC1 in tomato. Piriformospora indica did not promote growth in Sladc1-(virus-induced gene silencing of SlADC1) lines of tomato and showed less colonization. Furthermore, using LC–MS/MS we showed that Put promoted growth by elevation of auxin (indole-3-acetic acid) and gibberellin (GA4 and GA7) levels in tomato. In Arabidopsis (Arabidopsis thaliana) adc knockout mutants, P. indica colonization also decreased and showed no plant growth promotion, and this response was rescued upon exogenous application of Put. Put is also important for hyphal growth of P. indica, indicating that it is co-adapted by both host and microbe. Taken together, we conclude that Put is an essential metabolite and its biosynthesis in plants is crucial for P. indica-mediated plant growth promotion and fungal growth.
P009 Osteoporosis is a frequent complication in enthesitis related arthritis patients
Authors: Ferjani Hanene , Bettaieb Hiba , Maatallah Kaouther , Ben Nessib Dorra , Triki Wafa , Kaffal Dhia , Hamdi Wafa
Published: November 2021

Background

Enthesitis related arthritis (ERA) represents a clinical entity of juvenile idiopathic arthritis. This chronic rheumatic disease may lead to early bone mass loss and increase risk fracture. The aims of this study were to evaluate the prevalence of clinical osteoporosis in patients with ERA and to identify what factors are associated with increased occurrence of osteoporosis.

Methods

We reviewed the medical records of patients with confirmed ERA. We analyzed their demographic data and the clinical characteristics. Dual-energy X-ray absorptiometry (DEXA) was used to determine bone status. Osteoporosis was defined as Z score <-2.5DS. Disease activity was evaluated by: erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Data were analyzed using the SPSS statistical package. A P-value < 0.05 was considered significant.

Results

Thirty-three patients (27 male and 7 female) with a mean age at of 23.8 ± 7.5 years were enrolled. The mean age at disease onset was 12 ± 2.6 years. Median disease duration was 108 months [12–408]. The median ESR and CRP levels were 35 mm/h [8–90] and 20 mg/l [1–70] respectively. Median BASDAI score was 4.7 [1–9.7]. At bone densitometry, osteoporosis and osteopenia were found in 44.1% and 23.5% cases respectively. None of the patients had a history of osteoporotic fractures. Long term corticosteroid therapy and sedentarily were noted in 18.2% and 47.1% of patients respectively. On statistical analysis, osteoporosis was associated with these parameters: age at ERA onset (P = 0.035), disease duration (P = 0.04), CRP (P = 0.009), BASDAI score (P = 0.05) and sedentarily (P = 0.031). Neither corticosteroid therapy (P = 0.68) nor high ESR level (P = 0.73) were associated with osteoporosis.

Conclusion

In this study, osteoporosis was a common extra articular feature during ERA. As adult spondyloarthritis, disease activity, duration and sedentarily seem to be associated with the bone loss.
P046 A review and retrospective case series of paediatric Sjögren’s syndrome from Southern Africa
Authors: Akhalwaya S Y , Webb K , Scott C
Published: November 2021

Background

Paediatric Sjögren’s syndrome (pSS) is an uncommon autoimmune paediatric disease, rarely reported in children in Africa. It remains an important consideration in a child with parotid swelling. Here, we present a retrospective case-series of four patients from a paediatric rheumatology clinic in South Africa and discuss some of the difficulties of diagnosis in our context.

Methods

We performed a retrospective analysis of patients who attend the Red Cross War Memorial Hospital Paediatric Rheumatology clinic between 2010 and 2019.

Result

The four patients diagnosed with Sjögren’s all had varied presentations and disease courses. There were 3 females and 1 male and the ages at diagnosis ranged from 6 to 19 years old. The time to diagnosis was prolonged and ranged from 1 month to 10 years. Two patients with primary pSS presented with extra-articular manifestations of arthritis, abdominal pain and fatigue, followed by dry mouth, dry eyes, parotid swelling and and suggestive histopathology. The remaining 2 patients had a secondary pSS due to juvenile onset SLE and tuberculosis respectively.

Conclusion

In less resourced settings the diagnosis of pSS is often delayed. Both patients with primary pSS had preceding extra-glandular manifestations. In less resourced settings, infectious diseases may present as pSS and associated rheumatic diseases causing secondary pSS must be considered.
P049 Comparison between the ACR 1997, SLICC 2012 and EULAR/ACR 2019 classification criteria in juvenile systemic lupus erythematosus
Authors: Faid T , Menjel I , Sakhi A , Bouayed K
Published: November 2021

Background

Juvenile systemic lupus erythematosus is a multisystem inflammatory autoimmune disease affecting patients under 16 years old. Diagnosis may be difficult because of the large clinical heterogeneity. Classification criteria are important to ensure a clear definition and consistent inclusion of patients in clinical trials. The objective of the work: is to Compare the performance of the classification criteria of the American College of Rheumatology (ACR 1997), those of the Systemic Lupus International Collaborating Clinics (SLICC 2012) and the new classification criteria together with the European League Against Rheumatism “EULAR” and the American College of Rheumatology “ACR” (EULAR/ACR 2019).

Methods

This is a cross-sectional retrospective study carried out in a tertiary care service over a period of one year, from January 1, 2020 to December 31, 2020. The patients were subjected to the different classification criteria ACR 1997, SLICC 2012 and EULAR/ACR 2019. All our patients were matched in age and sex with control cases followed for inflammatory disease (12 control cases).

Results

Six patients were diagnosed with juvenile systemic lupus erythematosus (JSL) over the period of our study. A clear predominance of women was noted with a sex ratio of 5 girls/1 boy. The mean age at the time of diagnosis was 9 years (extremes: 3 –12 years). The diagnosis was made after an average delay of 5 months (extremes: 1–12 months). All of our patients met the three classification criteria. Sensitivity to all criteria was noted at diagnosis and during the first months of follow-up with higher sensitivity for SLICC criteria. Regarding the control cases, 3 patients met the ACR 1997 criteria.

Conclusion

In this population of Juvenile systemic lupus erythematosus, the SLICC criteria gave the best results in terms of sensitivity and precision at the time of diagnosis and during the first months of follow-up, while the ACR 1997 criteria were less specific.
P059 Etiological profile of childhood uveitis in a Tunisian population: a 12-year retrospective study
Authors: Jomaa O , Ksiaa I , Khochtali S , Jguirim M , Khairallah M
Published: November 2021

Background

Uveitis in children represents 10% of all cases of uveitis. It is a serious condition with an often-insidious onset and evolution, and has a negative impact on visual prognosis with a risk of amblyopia or even blindness. The etiologies are varied. the aim of this study is to describe the epidemiological, clinical, and etiological characteristics of childhood uveitis during a period of 12 years.

Methods

A descriptive retrospective study including 138 children (276 eyes) with uveitis, was conducted at the Ophthalmology Department of Fattouma Bourguiba University Hospital in Monastir Tunisia between 1 January 2006 and 31 December 2017.

Results

The patients average age was 10.2 ± 3,58. A female predominance was noted (sex ratio: 0.91). Uveitis was bilateral in 2/3 of cases and unilateral in 1/3 of cases. Vision loss was the most common reason for consultation (52.2%). The mean initial visual acuity was 3,3/10 ± 3,24. Intermediate uveitis was the most common anatomical form (42,02%), followed by anterior uveitis (28,26%), panuveitis (26,08%), and posterior uveitis (3,6%). The infectious origin was the most common aetiology, followed by uveitis related to general condition (13,72%), and uveitis in context of a specific ocular condition (12,3%). Uveitis was idiopathic in 79 patients (57.24%). Periocular injection of triamcinolone acetonide was performed in (29 patients, 21%). The use of immunosuppressives agents was noted in 38 patients (27,5%) (methotrexate: 23 patients, azathioprine: 16 patients, and ciclosporin: 10 patients). The use of intravitreous injections of bevacizumab was noted in 6 patients (4.33%). Anti TNF alpha treatment was used for 2 patients. Post-uveitic complications were noted in 84.3% of cases. They were dominated by cataract (31,88%) at the anterior segment level. Cystoid macular oedema (31,88%) and retinal serous detachment (15,9%) were the major complications in the posterior segment. Mean final visual acuity was 5.98/10 ± 3,54. It was <1/10 in 14 eyes.

Conclusion

In our study a female predominance was noted. Intermediate uveitis was the most common anatomical form. The infectious origin was preponderant. Post-uveitic complications was dominated at the anterior segment level by cataract and cystoid macular oedema at the posterior segment.