bluuebunny/crossref_metadata_2025 huggingface dataset:
First-principles study of magnetic order in graphene nanoflakes as spin logic devices
Authors: Chi Ming-He  , Zhao Lei  ,   Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Heilongjiang Provincial Key Laboratory of Dielectric Engineering, School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China
Published: December 2020

Scale effect and topological frustration can form magnetic order in the finite graphene structures (graphene nanoflakes (GNFs)). In this paper, the GNFs that can generate large net electron spin or electron spin antiferromagnetic coupling between local regions of net electron spins are classified reasonably. Representative special GNF configurations are proposed to be effectively used as fundamental logic gate devices for ultra-fast high density spintronics, and theoretically investigated by the first-principles electron structure calculations based on spin-polarized density functional theory. The first-principles calculations are performed by utilizing all-electron numerical-orbital scheme in the M11-L form of meta-GGA exchange-correlation functional. The energy spectrum of singly occupied states and the isodensity surface of total spin distribution indicate evidently that spin-single-state electrons are localized on two sides of a representative double-triangle GNF and the spin polarizations of two GNF segments are in opposite directions, resulting in antiferromagnetic coupling, which is consistent with the results derived from the graph theory and Lieb theorem. The energy of antiferromagnetic spin-coupled state is 55 meV lower than that of ferromagnetic spin-coupled state, which is obviously higher than the thermodynamic threshold of the minimum energy dissipation at room temperature. The spin coupling energy of the double triangle GNF increases with the scaling of GNF dimension increasing. The magnetic coupling strength of the double triangle GNF with and without mirror symmetry approach to the maximum stable values of 50 meV and 200 meV respectively, which are remarkably higher that of quantum dots and transition metal atom systems. Due to the fact that the spin coupling strength of the GNF logic gate spin device can reach 200 meV, it can operate normally at ambient temperature with an error rate of 0.001 which can be easily improved by an error correction technique. The calculation results demonstrate that the proposed GNF logic gate can finely operate at ambient temperature with significantly low and correctable error rate. Recent experimental studies show that graphene nanodevices on a scale of only a few nanometers can be successfully fabricated by etching technique of electron beam and scanning probe. Furthermore, the properties of GNF spin logic devices are not sensitive to intrinsic defects. The triangular GNF with n carbon rings has only (n+2)2-3 carbon atoms, while it can endure n-1 internal defects, thus persisting in non-bond states and local magnetic moments. It is suggested that the full spin logic gate devices based on GNF can be realized by using the current advanced nano-processing technology.
Theoritical research on optical Stark deceleration and trapping of neutral molecular beams based on modulated optical lattices
Authors: Li Xiao-Yun  , Sun Bo-Wen  , Xu Zheng-Qian  , Chen Jing  , Yin Ya-Ling  , Yin Jian-Ping  ,   State Key Laboratory of Precision Spectroscopy, School of Physics and Materials Science, East China Normal University, Shanghai 200241, China
Published: December 2020

According to the optical Stark deceleration theory of using a stationary quasi-cw red-detuned optical lattice to slow and trap an arbitrary pulsed molecular beam, we propose a novel idea of using a modulated optical lattice instead of a stationary one to realize a multistage optical Stark deceleration. We analyze the motion of the decelerated molecules inside the optical decelerator, and study the dependence of the velocity of the decelerated molecular packet on the synchronous phase angle and the number of the deceleration stages (i.e. half the number of the optical-lattice cells) by using the Monte-Carlo method. The simulation results show that it takes longer time for the molecules to reach the detector as the number of the deceleration stages increases. The decelerated molecular wave packets are gradually separated from the large wave packets of the original molecular velocity distribution. And the higher the number of the deceleration stages, the lower the decelerated molecular speed is. In addition, we also study the influence of the initial phase angle of synchronous molecules under the same conditions. It is demonstrated that the higher the initial phase angle of synchronous molecules, the lower the decelerated molecular speed is and the smaller the number of molecules in the deceleration wave packet, so the phase space is compressed.
The result also shows that the modulated optical Stark decelerator does not have the process of molecular free flight, and thus improving the efficiency of deceleration for molecules. The ultra-cold molecules can be trapped in the optical lattice by rapidly turning off the modulation signal of the lattice. Comparing with the previous scheme, the doubled number of the deceleration stages is reached in the same optical lattice length since a modulated optical lattice is used. For a length of optical lattice of 3.71 mm, theoretical simulation results demonstrate that the speed of methane molecules is decelerated from 280 m/s to 172 m/s. Comparing with the previous results from 280 m/s to 232 m/s, the deceleration effect is improved by 26%. Our scheme can not only obtain an ultra-colder molecular packet under the same molecular-beam parameters and deceleration conditions, but also be directly used to trap the slowed cold molecules after the deceleration without needing to use other techniques for molecular trapping.
Multiphoton ionization dissociation dynamics of iodoethane studied with velocity map imaging technique
Authors: Yan Yi-Hui  , Liu Yu-Zhu  , Ding Peng-Fei  , Yin Wen-Yi  ,   Jiangsu Key Laboratory for Optoelectronic Detection of Atmosphere and Ocean, Nanjing University of Information Science and Technology, Nanjing 210044, China;,   Jiangsu Collaborative Innovation Center on Atmospheric Environment and Equipment Technology, Nanjing 210044, China
Published: December 2020

Halogenated alkanes destroy the ozone layer, and iodoethane is one of the important representative halogenated alkanes. Time-of-flight mass spectrometry and velocity map imaging technique are used for investigating the photoionization dissociation dynamics of iodoethane, induced by 800 nm femtosecond laser. The dissociation mechanisms of iodoethane are obtained and discussed by analyzing the velocity distributions and angular distributions of the fragment ions generated in the dissociation. The measurements by time-of-flight mass spectrometry show that iodoethane cations generates C2H5+, I+, CH2I+, C2H2+, C2H3+ and C2H4+. The fragments related to CI bond fragmentation are C2H5+ ions and I+ ions, and the dissociation mechanisms are C2H5I+ C2H5++I and C2H5I+ C2H5+I+ respectively. Comparison between the configurations before and after ionization shows that the CI bond length is 0.2220 nm before ionization and turns longer and becomes 0.2329 nm after ionization. This indicates that the CI bond becomes more unstable after ionization and is more prone to dissociation. Moreover, the velocity map images of C2H5+ and I+ ions are acquired, from which the speed and angular distribution of C2H5+ and I+ are obtained. The analysis of speed distribution of the fragment ions shows that there are two channels, i.e. high energy channel and low energy channel in the dissociation process for producing C2H5+ and I+ ion. The difference between the ratios of the high energy channel and the low energy channel is small, indicating that the high energy channel and the low energy channel of the two dissociation processes are similar. According to the further analysis of the angular distribution of the fragment ions, it is found that the anisotropy parameter of C2H5+ is close to 0 (isotropic), the production channel of which may correspond to the slow vibration predissociation process. The anisotropy parameters of I+ ions are higher, which may be due to the rapid dissociation process on the repulsive potential energy surface. In addition, the density functional theory is used to calculate the configuration change of the iodoethane molecule before and after ionization, the energy level and oscillator strength for the ionic state in order to obtain more insights into the photodissociation dynamics.
Acoustic radiation torque on an off-axis elliptical cylinder in Gauss beams
Authors: Zang Yu-Chen , Lin Wei-Jun , Su Chang , Wu Peng-Fei ,   Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China,   University of Chinese Academy of Sciences, Beijing 100049, China,   Beijing Deep Sea Drilling Measurement Engineering Technology Research Center, Beijing 100190, China
Published: December 2020

As one of the nonlinear effects of acoustic waves, the time-averaged acoustic radiation torque expression is derived from the transfer of angular momentum from the incident beam to the object. In recent years, the acoustic radiation torque has received substantial attention since it is the underlying principle of well-controlled particle rotations and spins, which provides a new degree of freedom in particle manipulation and acousto-fluidic applications in addition to the translational displacement caused by the acoustic radiation force. Cylindrical particles, such as fibers, carbon nanotubes and other surface acoustic wave devices, are commonly encountered in various applications. The acoustic scattering coefficients for an elliptical cylinder arbitrarily located at the field of Gauss beam in two-dimensions are computed based on the partial-wave series expansion method and the Graf’s additional theorem for cylindrical functions to obtain the off-axis beam shape coefficients. It is worth mentioning that both the rigid and non-rigid cylinders are considered in this work, which requires different boundary conditions at the cylinder surface. Moreover, the closed-form expression of the acoustic radiation torque in this case is derived. On this basis, several numerical simulations are performed with particular emphasis on the off-axis distance, the incident angle and the beam waist. The simulated results show that both the positive and negative acoustic radiation torque can exist under certain conditions, which means that 1) the elliptical cylinder can be rotated in either the clockwise or the counterclockwise direction, 2) rigid elliptical cylinders are more likely to experience a strong acoustic radiation torque than non-rigid elliptical cylinders at low frequencies, 3) the incident wave field with a specific frequency can excite a different resonance scattering mode for a non-rigid elliptical cylinder, therefore the acoustic radiation torque peak is more related to the beam frequency than to the elliptical cylinder’s location in the field, and 4) increasing the beam width can enlarge the scattering cross section area, and thus enhancing the acoustic radiation torque on the elliptical cylinder. The results in this study are expected to provide a theoretical guide for the controllable rotation of a particle and the viscosity inversion of fluid by using the acoustic radiation torque. The exact formalism presented here by using the multipole expansion method, which is valid for any frequency range, can be used to validate other approaches by using purely numerical methods.
BUB-1 targets PP2A:B56 to regulate chromosome congression during meiosis I in C. elegans oocytes
Authors: Bel Borja Laura , Soubigou Flavie , Taylor Samuel J P , Fraguas Bringas Conchita , Budrewicz Jacqueline , Lara-Gonzalez Pablo , Sorensen Turpin Christopher G , Bembenek Joshua N , Cheerambathur Dhanya K , Pelisch Federico
Published: December 2020

Protein Phosphatase 2A (PP2A) is a heterotrimer composed of scaffolding (A), catalytic (C), and regulatory (B) subunits. PP2A complexes with B56 subunits are targeted by Shugoshin and BUBR1 to protect centromeric cohesion and stabilise kinetochore–microtubule attachments in yeast and mouse meiosis. In Caenorhabditis elegans, the closest BUBR1 orthologue lacks the B56-interaction domain and Shugoshin is not required for meiotic segregation. Therefore, the role of PP2A in C. elegans female meiosis is unknown. We report that PP2A is essential for meiotic spindle assembly and chromosome dynamics during C. elegans female meiosis. BUB-1 is the main chromosome-targeting factor for B56 subunits during prometaphase I. BUB-1 recruits PP2A:B56 to the chromosomes via a newly identified LxxIxE motif in a phosphorylation-dependent manner, and this recruitment is important for proper chromosome congression. Our results highlight a novel mechanism for B56 recruitment, essential for recruiting a pool of PP2A involved in chromosome congression during meiosis I.
The Influence of Absent/Present Mothers on Daughters in Fadia Faqir’s My Name Is Salma and Willow Trees Don’t Weep
Authors: Al-Khayyat Amal Adnan
Published: December 2020

This study demonstrates the influence of absent/present mothers on their daughters in Jordanian-British Fadia Faqir’s novels My Name Is Salma (2007) and Willow Trees Don’t Weep (2014). It manifests the difference between the positive and negative impacts of the mothers of Salma and Najwa, the two heroines in the two novels under discussion, respectively. The study also exposes the difference between Salma and Najwa based on their fragmentation and its intricate interconnection with their mothers, the way they deal with their mothers’ belongings, and the effect of the memories of their mothers on their self-formation. As it does so, the study highlights how each one of these heroines utilizes her mother’s influence on her to achieve self-formation in her own way as she crosses borders. Through its focus on the mother-daughter bond in both novels, the study concludes that despite the mother’s physical absence, her evident presence turns out to be inescapable; the positive influence of Salma’s absent mother helps Salma recollect herself, and the negative influence of Najwa’s absent mother helps Najwa shape her new identity.
An Analysis of Mood and Modality in Workplace Discourse and the Impact of Power Differentials: Ramsay’s Kitchen Nightmares
Authors: Aydh Saeed Dajem Zenah , Alyousef Hesham Suleiman
Published: December 2020

This qualitative study examines the interpersonal meaning of Mood and modality, specifically within the context of workplace discourse, and the influence of power on communication strategies. Its focus is to investigate the Mood structures used by interlocuters and to understand how a speaker’s choice of Mood demonstrates various interpersonal meanings. In addition, the paper explores the concept of modality, assessing the different ways in which speakers communicate to express their attitudes and judgments by employing the grammatical resources of modalization (probability) and modulation (inclination and obligation). Data were collected from an episode of Ramsay’s Kitchen Nightmares, a popular television series filmed in the U.S., in which Gordon Ramsay, a well-known professional chef, visits failing restaurant establishments. The data were transcribed verbatim before being analyzed to identify the use of Mood structures and modality, as well as whether the speakers’ power levels and social roles influenced their use of language. The results showed that interlocutors with a higher level of power, i.e., superiors in the work setting, typically used different Mood structures of the clause and different types of modality compared to those with less power, i.e., subordinates. These findings indicate that those in power play the role of instruction-givers, while those with less power are instruction-receivers. Interlocutors who are in power appear to have more opportunities to express their attitudes and judgments than their subordinates. As a result, they can influence workplace and business communication by making it more or less formal.
EFL Tutors’ and Learners’ Attitudes and Practices in the Writing Centers at the College of Languages and Translation
Authors: Musaed Alghizzi Talal , Alshahrani Tahani Munahi
Published: December 2020

This study investigates EFL Saudi male and female learners’ and tutors’ attitudes and practices in the Writing Centers at the College of Languages and Translation (CLTWCs) at Al-Imam Muhammad Ibn Saud Islamic University to determine the effectiveness of such centers. In fact, understanding EFL learners’ needs is believed to eliminate some of the persistent writing challenges for such learners; and therefore this study seeks to explore the relatively new established CLTWCs to improve their services. Thus, in order to answer the study’s two questions regarding the attitudes and practices of both tutors and learners, a cross-sectional quantitative research design was adopted by designing and administering two questionnaires among 29 faculty members (F = 18, M = 11) working in the centers and 217 students (F =112, M=105) visiting them. These questionnaires addressed demographic information, attitudes, and practices in the form of open-ended and/or closed-ended questions along with five Likert-Scale statements. The results showed that learners expressed a highly positive attitude toward the centers which could be attributed to the tutors. These tutors were reported to have excellent performance and professionalism during the sessions they had with the learners in question. Additionally, the findings cautiously suggest the importance of regular visits and motivation for students in order to obtain the desired and expected benefits of the centers.
The Effect of ECRIF Taxonomy in Foreign Language Teaching on Academic Achievement
Authors: Dalkıran Büşra , Semerci Çetin
Published: December 2020

The aim of this study is to determine the effect of ECRIF taxonomy in foreign language teaching on academic achievement. For this purpose, this study has been carried out with 56 students at 4th grade of primary education in 2018–2019 academic years. In the research, pretest posttest control group design of experiment method has been used. This study covered a period of 5 weeks and the unit of “Cartoon Characters” in English lesson. As data collection tool, achievement test for listening and speaking which was developed by the researcher was used. In the analysis of data, pretest and posttest scores were compared by using t-test for dependent groups. In addition, to explain power of relation, effect size (Cohens’ d) values were calculated. As a result of study, it was stated that ECRIF taxonomy provided significant differences in students’ academic success in favour of the experimental group.
Acquired small cell lung cancer resistance to Chk1 inhibitors involves Wee1 up‐regulation
Authors: Zhao Xiaoliang , Kim In‐Kyu , Kallakury Bhaskar , Chahine Joeffrey J. , Iwama Eiji , Pierobon Mariaelena , Petricoin Emanuel , McCutcheon Justine N. , Zhang Yu‐Wen , Umemura Shigeki , Chen Vincent , Wang Changli , Giaccone Giuseppe
Published: December 2020

Platinum‐based chemotherapy has been the cornerstone treatment for small cell lung cancer (SCLC) for decades, but no major progress has been made in the past 20 years with regard to overcoming chemoresistance. As the cell cycle checkpoint kinase 1 (Chk1) plays a key role in DNA damage response to chemotherapeutic drugs, we explored the mechanisms of acquired drug resistance to the Chk1 inhibitor prexasertib in SCLC. We established prexasertib resistance in two SCLC cell lines and found that DNA copy number, messengerRNA (mRNA) and protein levels of the cell cycle regulator Wee1 significantly correlate with the level of acquired resistance. Wee1 small interfering RNA (siRNA) or Wee1 inhibitor reversed prexasertib resistance, whereas Wee1 transfection induced prexasertib resistance in parental cells. Reverse phase protein microarray identified up‐regulated proteins in the resistant cell lines that are involved in apoptosis, cell proliferation and cell cycle. Down‐regulation of CDK1 and CDC25C kinases promoted acquired resistance in parental cells, whereas down‐regulation of p38MAPK reversed the resistance. High Wee1 expression was significantly correlated with better prognosis of resected SCLC patients. Our results indicate that Wee1 overexpression plays an important role in acquired resistance to Chk1 inhibition. We also show that bypass activation of the p38MAPK signaling pathway may contribute to acquired resistance to Chk1 inhibition. The combination of Chk1 and Wee1 inhibitors may provide a new therapeutic strategy for the treatment of SCLC.
Anti‐pyroptotic function of TGF‐β is suppressed by a synthetic dsRNA analogue in triple negative breast cancer cells
Authors: Tamura Yusuke , Morikawa Masato , Tanabe Ryo , Miyazono Kohei , Koinuma Daizo
Published: December 2020

Development of innovative therapeutic modalities would address an unmet clinical need in the treatment of triple negative breast cancer (TNBC). Activation of retinoic acid‐inducible gene‐I (RIG‐I)‐like receptors (RLRs) such as melanoma differentiation‐associated gene 5 (MDA5) and RIG‐I in cancer cells is suggested to suppress tumor progression by inducing cell death. Transfection of polyI:C, a conventionally used synthetic double‐stranded RNA (dsRNA) analogue that activates RLRs, has been evaluated in clinical trials. However, detailed mechanisms of tumor suppression by RLRs, especially interactions with other signaling pathways, remain elusive. Here, we showed that transfection of polyI:C suppressed transforming growth factor‐β (TGF‐β) signaling in a MDA5‐ and RIG‐I‐dependent manner. We found that suppression of TGF‐β signaling by polyI:C promoted cancer cell death, which was attenuated by forced expression of constitutively active Smad3. More detailed analysis suggested that cell death by polyI:C transfection exhibited characteristics of pyroptosis, which is distinct from apoptosis. Therapeutic efficacy of polyI:C transfection was also demonstrated using a mouse model. These results indicated that intratumor administration of polyI:C and related dsRNA analogues may be promising treatments for TNBC through inhibition of the anti‐pyroptotic function of TGF‐β.
Molecular profiling of long‐term responders to immune checkpoint inhibitors in advanced non‐small cell lung cancer
Authors: Frigola Joan , Navarro Alejandro , Carbonell Caterina , Callejo Ana , Iranzo Patricia , Cedrés Susana , Martinez‐Marti Alex , Pardo Nuria , Saoudi‐Gonzalez Nadia , Martinez Debora , Jimenez Jose , Sansano Irene , Mancuso Francesco M. , Nuciforo Paolo , Montuenga Luis M. , Sánchez‐Cespedes Montse , Prat Aleix , Vivancos Ana , Felip Enriqueta , Amat Ramon
Published: December 2020

Immunotherapy has transformed advanced non‐small cell lung cancer (NSCLC) treatment strategies and has led to unprecedented long‐lasting responses in some patients. However, the molecular determinants driving these long‐term responses remain elusive. To address this issue, we performed an integrative analysis of genomic and transcriptomic features of long‐term immune checkpoint inhibitors (ICIs)‐associated responders. We assembled a cohort of 47 patients with NSCLC receiving ICIs that was enriched in long‐term responders [>18 months of progression‐free survival (PFS)]. We performed whole‐exome sequencing from tumor samples, estimated the tumor mutational burden (TMB), and inferred the somatic copy number alterations (SCNAs). We also obtained gene transcription data for a subset of patients using Nanostring, which we used to assess the tumor immune infiltration status and PD‐L1 expression. Our results indicate that there is an association between TMB and benefit to ICIs, which is driven by those patients with long‐term response. Additionally, high SCNAs burden is associated with poor response and negatively correlates with the presence of several immune cell types (B cells, natural killers, regulatory T cells or effector CD8 T cells). Also, CD274 (PD‐L1) expression is increased in patients with benefit, mainly in those with long‐term response. In our cohort, combined assessment of TMB and SCNAs burden enabled identification of long‐term responders (considering PFS and overall survival). Notably, the association between TMB, SCNAs burden, and PD‐L1 expression with the outcomes of ICIs treatment was validated in two public datasets of ICI‐treated patients with NSCLC. Thus, our data indicate that TMB is associated with long‐term benefit following ICIs treatment in NSCLC and that TMB, SCNAs burden, and PD‐L1 are complementary determinants of response to ICIs.
Risk of target coverage loss for stereotactic body radiotherapy treatment of synchronous lung lesions via single‐isocenter volumetric modulated arc therapy
Authors: Critchfield Lana C. , Bernard Mark E. , Randall Marcus E. , McGarry Ronald C. , Pokhrel Damodar
Published: December 2020

Treating multiple lung lesions synchronously via single‐isocenter volumetric modulated arc therapy (VMAT) stereotactic body radiation therapy (SBRT) improves treatment efficiency and patient compliance. However, aligning multiple lung tumors accurately on single pretreatment cone beam CTs (CBCTs) can be problematic. Tumors misaligned could lead to target coverage loss. To quantify this potential target coverage loss due to small, clinically realistic setup errors, a novel simulation method was developed. This method was used on 26 previously treated patients with two metastatic lung lesions. Patients were treated with 4D CT‐based, highly conformal noncoplanar VMAT plans (clinical VMAT) with 6MV‐flattening filter free (FFF) beam using AcurosXB dose calculation algorithm with heterogeneity corrections. A single isocenter was placed approximately between the lesions to improve patient convenience and clinic workflow. Average isocenter to tumor distance was 5.9 cm. Prescription dose was 54 Gy/50 Gy in 3/5 fractions. For comparison, a plan summation (simulated VMAT) was executed utilizing randomly simulated, clinically relevant setup errors, obtained from pretreatment setup, per treatment fraction, in Eclipse treatment planning system for each of the six degrees of freedom within ± 5.0 mm and ± 2°. Simulations yielded average deviations of 27.4% (up to 72% loss) (P < 0.001) from planned target coverage when treating multiple lung lesions using a single‐isocenter plan. The largest deviations from planned coverage and desired biological effective dose (BED10, with α/β = 10 Gy) were seen for the smallest targets (<10 cc), some of which received < 100 Gy BED10. Patient misalignment resulted in substantial decrease in conformity and increase in the gradient index, violating major characteristics of SBRT. Statistically insignificant differences were seen for normal tissue dose. Although, clinical follow‐up of these patients is ongoing, the authors recommend an alternative treatment planning strategy to minimize the probability of a geometric miss when treating small lung lesions synchronously with single‐isocenter VMAT SBRT plans.
Pregnancy and Rheumatic Disease: Experience at a Single Center in New York City During the COVID‐19 Pandemic
Authors: Barbhaiya Medha , Stamm Bessie , Vitone Gregory , Frey Marianna B. , Jannat‐Khah Deanna , Levine Jonah , Vega JoAnn , Feldman Candace H. , Salmon Jane E. , Crow Mary K. , Bykerk Vivian , Lockshin Michael D. , Sammaritano Lisa , Mandl Lisa A.
Published: December 2020

Objective

The present study was undertaken to evaluate the pregnancy experiences of women receiving care in the division of rheumatology at a major academic center in New York City during the COVID‐19 pandemic.

Methods

A web‐based COVID‐19 survey was emailed to 26,045 patients who were followed in the division of rheumatology at a single center in New York City. Women ages 18–50 years were asked about their pregnancy. We compared the COVID‐19 experience between pregnant and nonpregnant women and also explored the impact of the pandemic on prenatal care and perinatal outcomes.

Results

Among 7,094 of the 26,045 respondents, 1,547 were women ages 18–50 years, with 61 (4%) reporting being pregnant during the pandemic. The prevalence of self‐reported COVID‐19 was similar in pregnant and nonpregnant women (8% versus 9%, respectively; P = 0.76). Among women with COVID‐19, pregnant women had a shorter duration of symptoms (P < 0.01) and were more likely to experience loss of smell or taste (P = 0.02) than nonpregnant women. Approximately three‐fourths of women had a systemic rheumatic disease, with no differences when stratified by pregnancy or COVID‐19 status. In all, 67% of pregnant women noted changes to prenatal care during the pandemic, and 23% of postpartum women stated that the pandemic affected delivery.

Conclusion

Among women followed in the division of rheumatology at a major center in New York City, pregnancy was not associated with increased self‐reported COVID‐19. Pregnancy was associated with a shorter duration of COVID‐19 symptoms and a higher prevalence of loss of smell or taste. The COVID‐19 pandemic impacted prenatal care for the majority of pregnant patients.
Vertical Strain Engineering of Epitaxial La2/3Sr1/3MnO3 Thin Films by Spontaneously Embedding ZrO2 Nanopillar Arrays
Authors: Cao Guixin , Song Kepeng , Qiao Liang , Guo Junjie , Han Weihua , Shen Xuechu , Du Kui , Zhang Jincang , Singh David J. , Gao Yuze
Published: December 2020

Rational control of local strain distributions and thus the functional properties of epitaxial thin films has been a long‐standing goal in the development of new physics and novel devices based on strain‐sensitive materials. Here, the fabrication of La2/3Sr1/3MnO3 (LSMO) films with strain fields arising from vertical epitaxial embedding of ultra‐small ZrO2 nanopillars, diameter 4.0 ± 0.6 nm, is reported. High quality films are obtained with average distance between adjacent nanopillars of 9.0 ± 0.3 nm for x = 0.2 in (LSMO)1−x:(ZrO2)x. The strain distribution of the vertical interface is analyzed in detail and the dominant state of the interfacial strain is verified. Remarkably, with increasing x, the Curie temperature TC and metal–insulator (MI) transition temperature TMI show a surprisingly large depression, revealing the significant tuning capability of the vertical tensile stress originating from the small‐size ZrO2 pillars. A systematic tunability of the low field magnetoresistance is also found. The field dependence of the magnetization exhibits both horizontal and vertical shifts. The exchange bias field HE increases with increasing x, while magnetization shift Mshift is unchanged. The results suggest the possibility of strain tuning through epitaxial nanostructures for multifunctional applications across many fields with appropriate selection of matrix and nanopillar materials.
Ultralow Loading (Single‐Atom and Clusters) of the Pt Catalyst by Atomic Layer Deposition Using Dimethyl ((3,4‐η) N,N‐dimethyl‐3‐butene‐1‐amine‐N) Platinum (DDAP) on the High‐Surface‐Area Substrate for Hydrogen Evolution Reaction
Authors: Ramesh Rahul , Han Seungmin , Nandi Dip K. , Sawant Sandesh Y. , Kim Deok Hyun , Cheon Taehoon , Cho Moo Hwan , Harada Ryosuke , Shigetomi Toshiyuki , Suzuki Kazuharu , Kim Soo‐Hyun
Published: December 2020

Single‐atom Pt catalyst has seen a tremendous surge in the research community in very recent times. The minimum loading of such precious metal catalysts on high surface area substrates with effective performance toward catalyzing a reaction is indeed of great importance. Here, an alternative way is demonstrated to perform an ultralow loading of Pt catalyst by atomic layer deposition (ALD) using dimethyl ((3,4‐η) N,N‐dimethyl‐3‐butene‐1‐amine‐N) platinum precursor (C8H19NPt). The ultralow loading of Pt catalyst is performed on highly porous nitrogen–carbon‐powder coated carbon cloth (NC–CC) substrates by varying the number of ALD cycles (2 to 60), and their performance in electrochemical hydrogen evolution reaction (HER) is evaluated. The inductively coupled plasma‐optical emission spectrometry provides the exact mass of the Pt catalyst, whereas, the transmission electron microscopy images confirm the uniform and homogeneous dispersion of platinum single‐atoms and clusters (with an average size of <1 nm for ten ALD cycles) on the NC–CC substrate. It is further found that the mass activity of Pt catalyst (per microgram of Pt) toward HER is extraordinarily high for less number of ALD cycles (two and five), whereas, the overall performance (current density per geometrical area) becomes more and more improved with increasing the ALD cycles.
Water Dispersive Suprastructures: An Organizational Impact on Nanomechanical Properties
Authors: Dobryden Illia , Yang Zhijie , Claesson Per M. , Pileni Marie Paule
Published: December 2020

Water dispersive 2D and 3D suprastructures offer a large number of potential applications in energy release, biomedicine and other fields. The nanomechanical properties of two suprastructures of self‐assembled 9.6 nm Fe3O4 hydrophobic nanocrystals dispersed in water are elucidated by using atomic force microscopy. These suprastructures are either a shell consisting of a few layers of nanocrystals or spherical self‐assemblies of nanocrystals in fcc superlattices called colloidosomes and supraballs, respectively. The major difference in the preparation of these suprastructure is based on the presence or not of octadecene molecules. It is recently demonstrated that these structures behave as nanoheaters and remain self‐assembled after internalization in cancer cells. The observed differences between these suprastructures in terms of cell sensing are suggested to be related to their mechanical properties, which emphasize the importance of better understanding the nanomechanics of such suprastructures. In this study the nanomechanical properties of these suprastructures are shown to be load‐depended in aqueous medium. Colloidosomes demonstrate higher flexibility and deformability than the supraballs. These findings provide essential knowledge for understanding differences in cell internalization and implementation in biomedicine. The differences in nanomechanical properties between these types of suprastructures are mainly due to their structures (hollow core–shell or fcc supracrystals).
Preparation of Nacre‐Like Polyimide/Montmorillonite Composite Films with Excellent Water Vapor Barrier Properties by Gravity‐Induced Deposition
Authors: Yu Qiaoxi , Zhu Longji , Liu Teng , Babu Seenivasagaperumal Sriram , Zheng Zhibo , Liu Siwei , Chi Zhenguo , Zhang Yi , Xu Jiarui
Published: December 2020

Polymers are ideal materials for preparing flexible barrier films because of their flexibility and other outstanding comprehensive properties. However, the gas barrier performance of polymer is far from meeting the requirements of flexible electronics encapsulation and its technology is still very challenging. In this study, by imitating the “brick‐mortar” structure of nacres, the nacre‐like composites made by polyimide (PI) and montmorillonites (MMTs) are successfully prepared by gravity‐induced deposition. These composite films exhibit excellent water vapor barrier performance even under high humidity conditions. The water vapor transmission rate of the best composite film (PNC50) is 0.023 g m−2 day−1, which is 3 orders of magnitude lower than that of pure PI. Mechanism studies are carried out by the help of carbon quantum dots, which could “lighting up” the MMTs and thus directly reflect the dispersion state of MMT in the composite films. With a fluorescence confocal microscopy, it can be observed that MMTs are evenly arranged on the surface, effectively blocking the entry of water vapor; moreover, the dense laminated structure of MMTs can prevent the diffusion of water vapor, all of which are beneficial to improve the water vapor barrier property of the composite films.
Defect‐State Lasing in Photonic Lattices of Metal–Organic Microcavities
Authors: Kliem Mona , Kiel Thomas , Kück Malin , Meister Stefan , Mischok Andreas , Fröb Hartmut , Busch Kurt , Leo Karl
Published: December 2020

Photonic band structure engineering has developed into an important technique for controlling the emission and interaction of photons and polaritons in microcavities (MCs). Herein, lasing from defect states (DSs) in photonic Kronig–Penney structures embedded into metal–organic MCs is demonstrated. As compared to the more delocalized lasing states associated with photonic bands, these DSs exhibit improved lasing thresholds that lie even below the lasing threshold of the metal‐free cavity. The characteristics of these DSs are determined via full electrodynamic computations based on the discontinuous Galerkin time‐domain method.
A Solution‐Processable Polymer‐Based Thin‐Film Thermoelectric Generator
Authors: Kluge Regina M. , Saxena Nitin , Müller-Buschbaum Peter
Published: December 2020

Thermoelectric modules are capable of transforming thermal energy into electrical power. Implementing earth‐abundant and cost‐effective organic materials, they can contribute to an eco‐friendly way of energy production out of low‐grade waste heat and natural heat sources via the Seebeck effect. Moreover, the flexibility of organic materials can allow for adaption to curved surfaces such as the human skin and wearable electronics. Herein, a solution‐processable thermoelectric generator (TEG) using exclusively polymers as active materials is presented. The high‐mobility n‐type polymer poly[[N,N‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5‐(2,2‐bithiophene)] (P(NDI2OD‐T2)) and the widely studied p‐type polymer blend poly(3,4‐ethylene‐dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) are combined into a thin‐film TEG. The presented device design is not limited to this system but is applicable to any pair of organic materials processable from solution and can be easily upscaled to fully flexible devices via, e.g., printing and roll‐to‐roll processing.
Maize yield under Urochloa ruziziensis intercropping and previous crop nitrogen fertilization
Authors: Mingotte Fábio Luíz Checchio , Jardim Celso Antônio , do Amaral Camila Baptista , Coelho Anderson Prates , Morello Orlando Ferreira , Leal Fábio Tiraboschi , Lemos Leandro Borges , Fornasieri Filho Domingos
Published: December 2020

Maize intercropping with forage crops and N under no‐tillage management have led to discrepant results regarding the impact on crop yield. Therefore, understanding various production systems is necessary to assist producers in decision making. The aim of this experiment was to evaluate whether maize (Zea mays L.) intercropping with Urochloa ruziziensis (R. Germ. and C.M. Evrard) Crins promotes differences in the agronomic performance of maize and if split top‐dressing N fertilization in the previous crop (common bean [Phaseolus vulgaris L.]) promotes increase in maize agronomic performance. The experiment was conducted during two agricultural years in southeastern Brazil, with treatments arranged as a split‐plot fitted in a randomized block design, with four replications. Main plot was cropping systems (two systems ‐ maize sole and maize intercropped with U. ruziziensis) while subplots comprised 10 combinations of split top‐dressed N applications, totaling 90 kg ha−1, applied to the previously cultivated common bean crop. Regardless of the agricultural year, intercropping with U. ruziziensis sown simultaneously with maize reduced maize yield by 12% on average. Intercropping maize and U. ruziziensis increased soil coverage from an average of 64–100% over maize as an only crop. The agronomic performance of maize grown in sole crop or intercropped with U. ruziziensis was not influenced by the effect of top‐dressing N fertilization applied in common bean under no‐tillage as previous crop. Intercropping maize with U. ruziziensis is a viable option for producers seeking improved soil coverage or grazing opportunities, however, caution is needed since maize yields may be reduced.
Phytoextraction of lead and arsenic from agricultural soils by different intercropping density of Boehmeria nivea (L.) and Pteris vittata (L.)
Authors: Wang Dong , Zhu ShouJing , Lu YanWei , Zeng Rui , Hu ZhiXin , Li Xiang , Jie YuCheng
Published: December 2020

This study aimed to analyze the heavy metal absorption characteristics of different plant species and planting patterns on lead (Pb) and arsenic (As) levels in soil. Two ramie [Boehmeria nivea (L.) Guad.] varieties (Zhongzhu‐1 and Xiangzhu‐3), and Pteris vittata L. were cultivated in monoculture and intercropping patterns in soil polluted with heavy metals (Pb and As). The plant traits and biomasses of Zhongzhu‐1 and Xiangzhu‐3 intercropped with P. vittata at a high density were not significantly different compared to their individual monoculture treatments. Meanwhile, the biomass of P. vittata intercropped with ramie was significantly reduced. In addition, the Pb content and Pb accumulation in shoots of Zhongzhu‐1 and Xiangzhu‐3 intercropped with P. vittata at high density significantly increased compared with the Pb content and Pb accumulation from monoculture shoots. The Xiangzhu‐3/P. vittata high density intercropping system had the highest Pb extraction at 232.14 g hm−2 and a Pb extraction efficiency of 0.0222%. The P. vittata monoculture system had the highest As extraction with 225.87 g hm−2 and an As extraction efficiency of 0.2765%. Moreover, ramie and P. vittata intercropping at high density was the most efficacious planting method for minimizing Pb–As pollution in soil with higher and effective remediation efficiency and economic benefit than monoculture planting system.
Household dairy demand by income groups in an urban Chinese province: A multistage budgeting approach
Authors: Wu Beibei , Shang Xudong , Chen Yongfu
Published: December 2020

Price and income elasticities are estimated for six food categories and different types of dairy across low‐, medium‐, and high‐income groups using 7426 urban households in Guangdong province from 2007 to 2009. Results from the estimation of a multistage budgeting approach to deal with zero expenditure show that demand for milk and dairy items among low‐income groups is more sensitive to income and price fluctuations compared to medium‐ and high‐income families. Therefore, a program of large income or price subsidies for dairy items may be an effective policy solution to improve the nutrition of the poor households. [EconLit citations: P46, Q18, O12].
Development of dual‐model classical density functional theory and its application to gas adsorption in porous materials
Authors: Hong Dandan , Liu Yu , Liu Honglai , Hu Ying
Published: December 2020

Classical density functional theory (CDFT) is a useful theory in many fields. The basis of CDFT is spherical model and extending it to nonspherical molecules is a challenging issue due to the orientation/configuration of the molecules, which implies more complicated molecular models, and higher computational costs. In this work, we propose a dual‐model classical density functional theory (DM‐CDFT) to address this issue. The theory uses a more precise model (all‐atom model) and a simpler model (coarsening model) to construct the external and excess free energy functionals, respectively. By using this methodology, CDFT could handle orientation/configuration effects with low computational costs. The theory is examined by applying it to gas adsorption (such as C2H2/C2H4/C2H6 and toxic gases) in porous materials, and the predicted adsorption isotherms verify the accuracy of the theory. Additionally, the predicted density profile indicates that rotation entropy plays an important role in the adsorption of nonspherical molecules.
Cardiopulmonary arrest secondary to compression of the heart owing to esophageal hiatal hernia: a case report
Authors: Ohira Shusaku , Okada Yoshito , Ishida Yosuke , Akiyama Sojiro
Published: December 2020

Background

Esophageal hiatal hernia is commonly encountered in clinical practice. We describe a case of cardiac compression caused by an esophageal hiatal hernia that resulted in circulatory failure and cardiac arrest.

Case Presentation

An 82‐year‐old woman presented to our hospital with vomiting, which progressed to cardiac arrest in the emergency room after computed tomography (CT) imaging. CT revealed gastric herniation into the mediastinum, with marked cardiac compression. Cardiopulmonary resuscitation was performed, and a nasogastric tube was inserted for gastric decompression, which resulted in the return of spontaneous circulation and subsequent hemodynamic stabilization. However, the patient died of aspiration pneumonia 4 days later.

Conclusion

Gastric decompression can lead to rapid improvements in respiration and circulation in patients with an esophageal hiatal hernia. Nonetheless, to prevent complications, such as those observed in our patient, definitive surgical treatment is warranted.
Infected abdominal aorta aneurysm secondary to streptococcal toxic shock syndrome due to Streptococcus pyogenes: a case report from Japan
Authors: Taniguchi Shiho , Sato Yukio , Shimatani Naotaka , Torii Yosaku , Sekimizu Mariko , Kamiya Yuki , Matsubara Kentaro , Obara Hideaki , Sasaki Junichi
Published: December 2020

Background

Infected aortic aneurysm secondary to streptococcal toxic shock syndrome caused by Streptococcus pyogenes is uncommon and associated with high mortality.

Case presentation

A 75‐year‐old man with metastatic lung cancer and an abdominal aortic aneurysm presented with high fever for 3 days. He was diagnosed with septic shock and was admitted to our hospital. The blood culture was positive for S. pyogenes, and streptococcal toxic shock syndrome was diagnosed. During treatment, enhanced computed tomography revealed an increase in the size of the abdominal aortic aneurysm, leading to the diagnosis of an infected aortic aneurysm. Replacement of the aneurysm with a synthetic graft was carried out successfully. The patient gradually recovered after the surgery.

Conclusion

We successfully managed an infected aortic aneurysm secondary to streptococcal toxic shock syndrome. Infected aortic aneurysms should be considered in patients with a medical history of aortic aneurysms and presenting with streptococcal toxic shock syndrome.
Assembly of The Mitochondrial Complex I Assembly Complex Suggests a Regulatory Role for Deflavination
Authors: Giachin Gabriele , Jessop Matthew , Bouverot Romain , Acajjaoui Samira , Saïdi Melissa , Chretien Anaïs , Bacia‐Verloop Maria , Signor Luca , Mas Philippe J. , Favier Adrien , Borel Meneroud Eve , Hons Michael , Hart Darren J. , Kandiah Eaazhisai , Boeri Erba Elisabetta , Buisson Alain , Leonard Gordon , Gutsche Irina , Soler‐Lopez Montserrat
Published: December 2020

Fatty acid β‐oxidation (FAO) and oxidative phosphorylation (OXPHOS) are mitochondrial redox processes that generate ATP. The biogenesis of the respiratory Complex I, a 1 MDa multiprotein complex that is responsible for initiating OXPHOS, is mediated by assembly factors including the mitochondrial complex I assembly (MCIA) complex. However, the organisation and the role of the MCIA complex are still unclear. Here we show that ECSIT functions as the bridging node of the MCIA core complex. Furthermore, cryo‐electron microscopy together with biochemical and biophysical experiments reveal that the C‐terminal domain of ECSIT directly binds to the vestigial dehydrogenase domain of the FAO enzyme ACAD9 and induces its deflavination, switching ACAD9 from its role in FAO to an MCIA factor. These findings provide the structural basis for the MCIA complex architecture and suggest a unique molecular mechanism for coordinating the regulation of the FAO and OXPHOS pathways to ensure an efficient energy production.