bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Big Data in the Promotion of Fast Selling Products
Authors: Cui Wenxin
Published: February 2021

In the traditional marketing mode of fast-selling products, the sales mode of physical stores is adopted. However, in the background of the current big data era, it is a trend to optimize the promotion form by applying big data technology. Therefore, this paper puts forward the application research of big data in the promotion of fast-selling products. This paper makes an indepth study on big data technology and commodity marketing. It is believed that there is a lot of information hidden behind the information data, and the application of big data technology pays more attention to consumer behavior than before. In this paper, according to the characteristics of fast-selling products promotion activities, combined with big data technology, the effect evaluation model are established, which can better solve the shortcomings of traditional promotion activities which are difficult to evaluate. And according to the actual needs of the promotion of fast-selling products, targeted optimization is carried out. In order to further verify the data analysis ability of big data technology in the promotion of fast selling products, this paper establishes the corresponding investigation experiment. The experimental data show that big data technology can better analyze the actual effect of various promotion tools and promotion strategies, provide technical support for enterprises before and after the promotion of fast-selling products, and facilitate enterprises to adjust strategies and summarize experience. The analysis shows that big data technology has brought a variety of convenience to the promotion activities, which not only broadens the sales channels, but also provides a new basis for the decision-making of enterprises.
Economic valuation of grassland utilization improvement in the Western Balkans
Authors: Željko Vaško , Rokvić Gordana
Published: February 2021

Grassland is land permanently overgrown with grasses that can be used for grazing or preparing fodder. When identifying and delineating grassland areas from other agricultural areas, criteria can be their purpose (land cover) or their use (land use). The processes of depopulation and deagrarization of rural areas increase the surfaces of unutilized grasslands and decrease of their use for agricultural purpose. The purpose of research presented in this paper is the analysis of transformation of grassland area in six Western Balkans countries/territories from covered to used status. During the research, the methods of quantitative modelling and simulation were combined. Starting from existing grassland areas (which are equalized with permanent meadows and pastures), the intensity of their use was determined by calculating the grazing livestock density (GLD) index. Generally, grasslands are used extensively for feeding ruminants in the WB region, and great part of the area is not used at all, so the average GLD index is 0.88 with significant variations between countries. Three countries (Bosnia and Herzegovina, Montenegro and North Macedonia) have a GLD of 0.5 or less and there is space for them to increasing the number of ruminants up to 1.1 million livestock standard units (LSU) and increasing livestock density up to one LSU per ha of grassland. The conclusion is that, depending on the scenario, i.e. the structure of ruminant stock (cattle, sheep and goats), the value of livestock production in the Western Balkans could increase from 498 to 655 million EUR, still without environmental pressure of grazing on grassland area.
Analysis of the impact of the allocation of European funds on rural development in Romania
Authors: (Popa) Podaru Alina Mariana , Turek Rahoveanu Adrian
Published: February 2021

Rural development within the European Union has been a continuous evolution of rural space through which it has responded to the needs and challenges of the European Community. Thus, the European Union has created and implemented the Common Agricultural Policy, and rural development is its second pillar. In the case of Romania, agriculture and rural development is a priority sector in terms of economic and social growth, due to the large area occupied by rural areas, but also due to the large area of agricultural land that is found on the territory of Romania. This article is intended to be an objective analysis of the impact that European funds have had on the development of the Romanian rural area regarding the allocation of these funds. At the same time, the degree of absorption of the National Rural Development Program (NRDP) was analysed.
Telomere Length in Idiopathic Recurrent Pregnancy Loss
Authors: Onat Taylan , Çaltekin Melike Demir , Inandiklioglu Nihal , Baser Emre , Kirmizi Demet Aydogan , Kara Mustafa , Ercan Fedi , Yalvac Ethem Serdar
Published: February 2021

Objective Telomere length is used as an indicator of biological aging. It is well known that one of the most remarkable risk factors of recurrent pregnancy losses is advanced maternal age. The objective of this study was to investigate the correlation between idiopathic recurrent pregnancy loss and telomere length.

Method The study group included 40 women, while the control group consisted of 41 healthy women whose age and body mass index were matched. A venous blood sample was taken from all participants into EDTA tubes in the early follicular phase, and telomere length was measured through the qPCR technique.

Results When the mean TL of the groups was compared, it was determined that TL was significantly shorter among the iRPL group (7763.89±924.58 base pair) compared to the control group (8398.84±1102.95 base pair) (p<0.006). Whereas FSH and E2 were higher in the iRPL group, TAFC was lower (p<0.001). When the correlation between telomere length and endocrine parameters was statistically tested in the iRPL group, a negative correlation was found between FSH and telomere length (r=-0.437; p<0.001).

Conclusion Shortened telomere length might play a role in the etiology of iRPL. We are of the opinion that patients with RPL should be screened for the presence of cardiovascular diseases and other chronic diseases, as is the case for POF.
Can Derived Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio, and Delta Neutrophil Index Predict Spontaneous Abortion?
Authors: Yakıştıran Betül , Tanacan Atakan , Altınboğa Orhan , Yücel Aykan
Published: February 2021

Objective To evaluate the efficacy of complete blood count indices for the prediction of miscarriage.

Materials and Methods A retrospective case-control study was conducted in a tertiary hospital. This study consisted of 389 cases (32 elective and 193 spontaneous abortions, 164 healthy pregnancies). Maternal demographic characteristics, complete blood cell (CBC) parameters, neutrophil-lymphocyte ratio (NLR), derived NLR, systemic inflammatory immune index (SII), platelet-to-lymphocyte ratio (PLR), and delta neutrophil index (DNI) that were in the routine first trimester CBC were compared between groups.

Results There were no significant differences among groups in terms of demographic and obstetric characteristics. Statistically significant differences were observed for Hb, white blood cell (WBC), lymphocyte (L), NLR, SII, and PLR between the subgroups (p=0.003, p=0.045, p=0.000, p=0.002, p=0.043, p=0.010, respectively). There were no significant differences among groups in terms of the remaining parameters. When healthy pregnancies and spontaneous abortions were compared, statistically significant differences were detected for NLR, SII, PLR (p=0.001, p=0.039, and p=0.000, respectively). Moreover, when healthy pregnancies and elective abortions were compared, only NLR was found as statistically different (p=0.050). Area under curve (AUC) was calculated for PLR as 0.659 (%95 CI: 0.582–0.735) and a cut-off value of 158.1 was found with highest sensitivity and specificity (60.6 % and 61.6%, respectively) according to the results obtained from Youden’s index. AUC was calculated for NLR as 0.591 (%95 CI: 0.507–0.675) and a cut-off value of 3.135 was found with highest sensitivity and specificity (56% and 54.5%) according to the results obtained from Youden’s index.

Conclusion In conclusion, decreased PLR and NLR levels may be used as practical and cost-effective markers for the prediction of miscarriages.
Organocatalyzed Asymmetric Aldol Reaction of α-Keto Amides with A Tripeptide Catalyst
Authors: Kohari Yoshihito , Kon Kazumasa , Takai Hiromu , Kobayashi Takumu , Murata Miki
Published: February 2021

An organocatalyzed asymmetric aldol reaction of α-keto amides was developed. An N-terminal 4-trans-siloxyproline-based tripeptide with an l-tert-leucine unit adjacent to the 4-trans-siloxyproline residue was used to catalyze the reaction between various α-keto amides and acetone, to produce the corresponding aldol adducts with up to 99% yield and 91% ee.
Primary Teeth Stains and Discoloration: A Review
Authors: Alazmah Abdulfatah
Published: February 2021

The current review assesses the literature concerning the etiology of primary teeth staining and discoloration. The appearance of the dentition is of concern to many children and their caregivers seeking dental treatment as the color of the teeth is of aesthetic importance. The correct diagnosis of the cause of the discoloration is important as, invariably, it has a profound effect on treatment outcomes. It would seem reasonable, therefore, that dental practitioners understand the etiology of tooth discoloration to make a diagnosis and enable appropriate treatment to be conducted. Knowledge of the etiology of tooth staining is of importance to the dental practitioner to explain the patient the exact nature of the condition. In some instances, the mechanism of staining affects the outcome of the treatment and influences the options the dentist will be able to offer. Many of these contributing factors are preventable if parents are educated, managed by professional interventions, or provide a multidisciplinary approach. In this review, we highlight the importance of children smiles and the difference between primary and permanent teeth. We discuss the different types of primary teeth staining and discoloration and whether it is intrinsic or extrinsic, as well as the different impacts of some conditions on primary teeth compared with permanent teeth.
Neuroimaging of Childhood Epilepsy: Focal versus Generalized Epilepsy
Authors: Assadsangabi Reza , Ozturk Arzu , Kantamneni Trishna , Azizi Nazarin , Asaikar Shailesh M. , Hacein-Bey Lotfi
Published: February 2021

Neuroimaging plays an increasingly crucial role in delineating the pathophysiology, and guiding the evaluation, management and monitoring of epilepsy. Imaging contributes to adequately categorizing seizure/epilepsy types in complex clinical situations by demonstrating anatomical and functional changes associated with seizure activity. This article reviews the current status of multimodality neuroimaging in the pediatric population, including focal lesions which may result in focal epileptic findings, focal structural abnormalities that may manifest as generalized epileptiform discharges, and generalized epilepsy without evidence of detectable focal abnormalities.
Not a Tumor-Nonspecific Orbital Inflammation
Authors: Garrity James A.
Published: February 2021

Objective This study was aimed to illustrate the features and complexities of nonspecific orbital inflammation via discussion of two representative cases.

Design Present study is a retrospective case review.

Setting The study was conducted at a tertiary care medical center.

Participants Two patients with nonspecific orbital inflammation were participants of this retrospective study.

Main Outcome Measures Outcome of the study was disease-free patients and off all medications.

Results At follow-up, both patients are disease free and off all medications.

Conclusion Surgery plays a diagnostic and therapeutic role. While the clinical subtype is important for differential diagnosis and symptomatic treatment, the histologic subtype is similarly important. For inflammatory dacryoadenitis, surgery can be therapeutic. For extensive granulomatosis with polyangiitis, debulking surgery may allow better penetration of medications, especially rituximab.
Surgical Approaches to the Orbit: Transpalpebral
Authors: Richards Nikisha Q.
Published: February 2021

The aim of this study is to provide an overview of the safe and effective incisional transpalpebral approaches to the orbit. The location of each approach and pertinent anatomy in each respective area, suggested approach techniques, recommended specialties, reconstruction options, intraoperative neurophysiology, complications, and approach limitations are discussed in detail.
A Study on 615 Cases of Idiopathic Epistaxis
Authors: Kida Tomoko , Oka Hideki , Fushimi Katsuya , Honda Mariko , Fujiki Junya , Tsuzuki Kenzo
Published: February 2021

Epistaxis is one of the most common complaints encountered in the field of otorhinolaryngology. Although hemostasis can be achieved by outpatient treatment in many cases, we have also encountered some difficult-to-treat patients who developed rebleeding or required admission and surgery. We conducted a retrospective analysis of the clinical features of 615 patients with idiopathic epistaxis who were seen at our hospital between 2012 and 2019. We analyzed the patient data and clinical factors associated with epistaxis, including the age, gender, month (season) of visit to our hospital, accompanying systemic complications, bleeding points, procedures used for treatment, history of rebleeding, and history of hospitalization. The patients with epistaxis were predominantly males in their 70s. In regard to the season of presentation, patients with epistaxis were encountered more frequently in the winter than in the summer. Most patients had initially been treated by electrocoagulation. Hypertension was the most common underlying disease. Rebleeding within 7 days after the primary treatment occurred in 11.5% (71/615) of patients. Analysis identified heart and liver disease and antithrombotic drug use as significant risk factors for rebleeding. Although in the overall subject population the bleeding point was most frequently observed in Kiesselbach plexus area, the bleeding point was observed more often in the middle nasal meatus or olfactory cleft in the patients with rebleeding. The most common indication of hospitalization was difficulty in hemostasis, and the bleeding point in most of the hospitalized cases was unknown or in the posterior nasal cavity. The analysis revealed that it may be important to attempt endoscopic hemostasis in patients in whom the bleeding point is identified in the posterior nasal cavity.
Untangling racism: Stress reactions in response to variations of racism against Black Canadians
Authors: Matheson Kimberly , Pierre Andrena , Foster Mindi D. , Kent Mathew , Anisman Hymie
Published: February 2021

The ability to effectively contend with racism is likely undermined by factors that promote uncertainty regarding racist motives. A national policy of multiculturalism exists in Canada, which is intended to encourage cultural diversity, but can also serve to mask systemic racism. This may contribute to uncertainty when racism is encountered, with implications for the appraisals, coping, and stress-related outcomes of ethnoracial minorities. Two studies were conducted to assess Black Canadians’ experiences of racism, and their reactions to variations in the nature of the experience. A survey study found that Black Canadians’ (n = 158) self-reported past encounters with explicit racism were associated with anger-out coping, which in turn was related to lower depressive affect. In contrast, ambiguous racism was related to keeping anger in and higher depressive affect; this relation was exacerbated when participants believed Blacks were held in high regard by others, likely adding uncertainty to interpreting behaviours as racist. An experimental study manipulated the nature of racist cues conveyed in a videotaped description of the experiences of a Black male interviewee. When the Black interviewee described racist experiences that were ambiguous (vs. explicit) both White (n = 112) and Black (n = 99) observers were less likely to appraise events as racist, even when physical violence was involved. However, the moment-to-moment distress elicited while listening the interviewee’s description of their racist experiences was uniquely associated with higher cortisol levels among Blacks (but not Whites), especially when physical violence was present. Taken together, the findings contribute to our understanding of the processes by which ambiguous racism might operate to undermine the well-being of targeted groups. Moreover, it is suggested that policies conveying that ethnoracial groups are highly valued (e.g., multiculturalism) might actually exacerbate negative effects of racist experiences, particularly in the absence of an open discourse acknowledging the presence of systemic racism.
Measuring fluid pressure and the impact of friction in water flow through sponge-like media
Authors: McConnon Aili
Published: February 2021

Researchers present an experimental setup for studying porous media that can monitor the pervadic pressure profile, fluid volume flux, and deformation of the material in real time.
Accuracy of the interferometric method for Leeb hardness testers calibration
Authors: Kazieva T. V. , Gubskiy K. L. , Tischenko I. Yu , Glukhov R. D. , Kuznetsov A. P.
Published: February 2021

In this article, we propose a method for improving accuracy in calibrating Leeb hardness testers using fiber interferometric systems. The calibration system is implemented using the photonic Doppler velocimetry technique. This paper provides estimates of the measurement uncertainty arising in the calibration system and describes a method for improving accuracy, which takes into account the signal-to-noise ratio, sampling rate, and processing parameters.
Multistability for nonlinear acoustic-gravity waves in a rotating atmosphere
Authors: Pati N. C. , Rech Paulo C. , Layek G. C.
Published: February 2021

The multistable states of low-frequency, short-wavelength nonlinear acoustic-gravity waves propagating in a small slope with respect to the vertical ones are explored in a rotating atmosphere. The bifurcation patterns en route to irregular behaviors and the long-term dynamics of the low-order nonlinear model system are studied for varying air Prandtl number σ between 0.5 and 1. In contrast to non-rotation, the transition to the unsteady motion occurs both catastrophically and non-catastrophically due to the Earth’s rotation. The connections between the Prandtl number and the slope parameter on the stabilities of the system are highlighted. The model system exhibits hysteresis-induced multistability with coexisting finite multi-periodic, periodic–chaotic attractors in certain parameter spaces depending on the initial conditions. Studies revealed that the rotation parameter instigates these heterogeneous coexisting attractors, resulting in the unpredictable dynamics. However, the relevance of this study is strongly restricted to a very small vertical wavelength, a small slope, and a weakly stratified atmosphere.
Synchronization of clocks and metronomes: A perturbation analysis based on multiple timescales
Authors: Goldsztein Guillermo H. , Nadeau Alice N. , Strogatz Steven H.
Published: February 2021

In 1665, Huygens observed that two pendulum clocks hanging from the same board became synchronized in antiphase after hundreds of swings. On the other hand, modern experiments with metronomes placed on a movable platform show that they often tend to synchronize in phase, not antiphase. Here, we study both in-phase and antiphase synchronization in a model of pendulum clocks and metronomes and analyze their long-term dynamics with the tools of perturbation theory. Specifically, we exploit the separation of timescales between the fast oscillations of the individual pendulums and the much slower adjustments of their amplitudes and phases. By scaling the equations appropriately and applying the method of multiple timescales, we derive explicit formulas for the regimes in the parameter space where either antiphase or in-phase synchronization is stable or where both are stable. Although this sort of perturbative analysis is standard in other parts of nonlinear science, surprisingly it has rarely been applied in the context of Huygens’s clocks. Unusual features of our approach include its treatment of the escapement mechanism, a small-angle approximation up to cubic order, and both a two- and three-timescale asymptotic analysis.
Proof-of-concept thermoelectric oxygen sensor exploiting oxygen mobility of GdBaCo2O5+δ
Authors: Biswas Soumya , Madhukuttan M , Kamble Vinayak B.
Published: February 2021

In this paper, we demonstrate a proof-of-concept oxygen sensor based on the thermoelectric principle using polycrystalline GdBaCo2O5+δ, where 0.45 < δ < 0.55 (GBCO). The lattice oxygen in layered double perovskite oxides is highly susceptible to the ambient oxygen partial pressure. The as-synthesized GBCO sample processed in ambient conditions shows a pure orthorhombic phase (Pmmm space group) and a δ-value close to 0.5 as confirmed by x-ray diffraction Rietveld refinement. The x-ray photoelectron spectroscopy (XPS) shows a significant Co3+ oxidation state in non-octahedral sites in addition to Co3+ as well as Co4+ in octahedral sites. The insulator-to-metal transition (MIT) is observed at 340 K as seen from resistivity and Seebeck coefficient. The Seebeck coefficient shows a large change of 10–12 μV/K with a time constant of ∼20 s at 300 K, when the gas ambience is changed from 100% oxygen to nitrogen and vice versa. The diffusion of oxygen in the GdOδ planes leads to the hole doping, which is a dominant factor for a large change observed in the Seebeck coefficient. This is also evident from the higher fraction of oxidized Co4+ as seen from XPS measurements. The interfacial grain boundary in addition to the oxygen diffusion contributes to the change in Seebeck. The change in Seebeck coefficient is minimal in the metallic state due to an insignificant increase in the carrier concentration, but the response is fairly well and reproducible for stoichiometry δ = 0.5 ± 0.05 below MIT. This principle shall be of significant importance in designing oxygen sensors operational at room as well as cryogenic temperatures.
Insight into the chemistry of TNT during shock compression through ultrafast absorption spectroscopies
Authors: Powell M. S. , Moore D. S. , McGrane S. D.
Published: February 2021

Thin films of trinitrotoluene (TNT) were shock compressed using the ultrafast laser shock apparatus at Los Alamos National Laboratory. Visible (VIS) and mid-infrared (MIR) transient absorption spectroscopies were simultaneously performed to probe for electronic and vibrational changes during shock compression of TNT. Three shock pressures (16 GPa, 33 GPa, and 45 GPa) were selected to observe no reaction, incipient reaction, and strongly developed reactions for TNT within the experimental time scale of <250 ps. Negligible absorption changes in MIR or VIS absorptions were observed at 16 GPa. At 33 GPa, MIR absorptions in the 3000 cm−1–4000 cm−1 range were observed to increase during the shock and continue to increase during the rarefaction, in contrast to the VIS absorption measurements, which increased during the shock and almost fully recovered during rarefaction. At 45 GPa, both VIS and MIR absorptions were strong and irreversible. The intense and spectrally broad MIR absorptions were attributed to short lived intermediates with strong, spectrally broad absorptions that dominate the spectral response. The MIR and VIS absorption changes observed at 33 GPa and 45 GPa were credited to shock induced chemistry, most likely including the formation of a very broad hydrogenic stretch feature. The results from these experiments are consistent with the chemical mechanisms that include O–H or N–H formation such as CH3 oxidation or C–N homolysis.
Magnetocaloric and heat capacity studies on NdFe0.5Mn0.5O3
Authors: Singh Ankita , Balasubramanian Padmanabhan , Anas Mohd. , Kumar Rinku , Babu P. D. , Kumar C. M. N. , Tabis Wojciech , Malik V. K.
Published: February 2021

The bulk magnetization, magnetocaloric effect, and heat capacity of polycrystalline NdFe0.5Mn0.5O3 have been studied in the temperature range of 1.5–300 K. The magnetic entropy change (ΔSM) shows a peak near 7 K at 100 kOe with a value of ∼7.22 J kg−1 K−1. Another magnetic entropy change is also observed between 0 and 40 kOe near the spin reorientation region of Fe3+/Mn3+ ions (∼45 K), wherein the entropy change gets suppressed with increasing field. The magnetic heat capacity shows a broad hump near the Néel temperature (∼250 K). Around 5 K, a step-like feature in heat capacity due to the Schottky effect is observed which is associated with the crystal field effects in Nd3+ ions.
FEM simulation of temperature field in a resistance-heated diamond anvil cell
Authors: Fan Xiaobing , Xiang Shikai , Chen Haiyan , Cai Lingcang
Published: February 2021

The temperature of the sample in a resistance-heated diamond anvil cell is difficult to be measured directly and usually is calibrated by reading from the thermocouple attached to the diamond bevel. It is unclear how the temperature difference between the diamond bevel and the sample is affected by external factors such as thermal radiation and air convection. We performed a finite-element method simulation of the temperature field in the resistance-heated diamond anvil cell under different external conditions, and our simulations demonstrate that a thermal insulation cover of a low emissivity material and a unique double-layer structure can effectively reduce the temperature difference. Meanwhile, there is a non-negligible difference between the sample temperature at ambient pressure and that at high pressure when the diamond bevel has the same temperature. Some results of simulations have been confirmed by experiments using a designed double-layer cover.
Enhancing CO2 plasma conversion using metal grid catalysts
Authors: Devid E. J. , Ronda-Lloret M. , Zhang D. , Schuler E. , Wang D. , Liang C.-H. , Huang Q. , Rothenberg G. , Shiju N. R. , Kleyn A. W.
Published: February 2021

The synergy between catalysis and plasma chemistry often enhances the yield of chemical reactions in plasma-driven reactors. In the case of CO2 splitting into CO and O2, no positive synergistic effect was observed in earlier studies with plasma reactors, except for dielectric barrier discharges, that do not have a high yield and a high efficiency. Here, we demonstrate that introducing metal meshes into radio frequency-driven plasma reactors increases the relative reaction yield by 20%–50%, while supported metal oxide catalysts in the same setups have no effect. We attribute this to the double role of the metal mesh, which acts both as a catalyst for direct CO2 dissociation as well as for oxygen recombination.
A frustrated bimeronium: Static structure and dynamics
Authors: Zhang Xichao , Xia Jing , Ezawa Motohiko , Tretiakov Oleg A. , Diep Hung T. , Zhao Guoping , Liu Xiaoxi , Zhou Yan
Published: February 2021

We show a topological spin texture called “bimeronium” in magnets with in-plane magnetization. It is a topological counterpart of skyrmionium in perpendicularly magnetized magnets and can be seen as a combination of two bimerons with opposite topological charges. We report the static structure and spin-orbit-torque-induced dynamics of an isolated bimeronium in a magnetic monolayer with frustrated exchange interactions. We study the anisotropy and magnetic field dependences of a static bimeronium. We also explore the bimeronium dynamics driven by the damping-like spin-orbit torque. We find that the bimeronium shows steady rotation when the spin polarization direction is parallel to the easy axis. Moreover, we demonstrate the annihilation of the bimeronium when the spin polarization direction is perpendicular to the easy axis. Our results are useful for understanding the fundamental properties of bimeronium structures and may offer an approach to build bimeronium-based spintronic devices.
A new damage estimation method for carbon fiber reinforced polymer based on electrical impedance tomography
Authors: Fan Wenru , Wang Chi
Published: February 2021

Damage estimation is vital for monitoring the remaining life of carbon fiber reinforced plastic/polymer (CFRP). As a non-invasive, non-radiative, and low-cost method, electrical impedance tomography (EIT) is increasingly investigated for the purpose of structural health monitoring of CFRP. The commonly used EIT method is limited by the image accuracy since it estimates the damage just through a reconstructed image. In this paper, a damage estimation method (DEM) is proposed to quantify the damage location and area. First, each damage is fitted into a two-dimensional Gaussian function through edge fitting. Then, the parameters of the Gaussian function are optimized with the two-norm regularization method. Finally, the damage location and area are estimated with the parameters of the Gaussian function. The accuracy of the DEM is directly evaluated in terms of location error and area error. Both simulation and experimental results demonstrated the potential of the proposed method in providing damage estimation information.
Highly efficient ∼8 μm-emitting, step-taper active-region quantum cascade lasers
Authors: Oresick K. M. , Kirch J. D. , Mawst L. J. , Botez D.
Published: February 2021

Recently, it was shown for 4.5 μm–5.0 μm-emitting, state-of-the-art quantum cascade lasers (QCLs) that the internal efficiency can be fully accounted for when considering interface-roughness (IFR)-triggered carrier leakage from both the upper-laser (ul) level and key injector states. By applying the same formalism to ∼8.0 μm-emitting QCLs of a step-taper active-region (STA) design, we find that the devices’ internal efficiency reaches a high value of ∼76%. That is partly due to a record-high injection-efficiency value (89%), as a result of strong carrier-leakage suppression, and partly due to an IFR-scattering enhanced laser-transition efficiency value of 85.2%. By comparison, when the same analysis is applied to conventional ∼8.0 μm-emitting QCLs, grown by the same crystal-growth technique: metal–organic chemical vapor deposition (MOCVD), the internal efficiency is found to be only ∼59%, typical of values extracted from experimental data of mid-infrared-emitting conventional QCLs. When further comparing the ∼8.0 μm-emitting STA QCLs with conventional QCLs, the ul-level lifetime is found to be controlled by both LO-phonon and alloy-disorder scattering, similar to what we recently found for 4.5 μm–5.0 μm-emitting QCLs. However, unlike 4.5 μm–5.0 μm-emitting QCLs, the lower-laser level lifetime is found to be controlled by both LO-phonon and IFR scattering. In addition to the high internal-efficiency value, the use of excited-state injection and a low voltage defect result in the STA QCL reaching a front-facet wall-plug efficiency value of 10.6%, a record-high, front-facet value for 8 μm–11 μm-emitting QCLs grown by MOCVD and holding potential for continuous-wave operation.
High quality GaN-on-SiC with low thermal boundary resistance by employing an ultrathin AlGaN buffer layer
Authors: Feng Yuxia , Sun Huarui , Yang Xuelin , Liu Kang , Zhang Jie , Shen Jianfei , Liu Danshuo , Cai Zidong , Xu Fujun , Tang Ning , Yu Tongjun , Wang Xinqiang , Ge Weikun , Shen Bo
Published: February 2021

High quality GaN films on SiC with low thermal boundary resistance (TBR) are achieved by employing an ultrathin low Al content AlGaN buffer layer. Compared with the conventional thick AlN buffer layer, the ultrathin buffer layer can not only improve the crystal quality of the subsequent GaN layer but also reduce the TBR at the GaN/SiC interface simultaneously. The ultrathin AlGaN buffer layer is introduced by performing a pretreatment of the SiC substrate with trimethylaluminum followed by the growth of GaN with an enhanced lateral growth rate. The enhanced lateral growth rate contributes to the formation of basal plane stacking faults (BSFs) in the GaN layer, where the BSFs can significantly reduce the threading dislocation density. We reveal underling mechanisms of reducing TBR and dislocation density by the ultrathin buffer layer. We propose this work is of great importance toward the performance improvement and cost reduction of higher power GaN-on-SiC electronics.
Contact-free reversible switching of improper ferroelectric domains by electron and ion irradiation
Authors: Roede Erik D. , Mosberg Aleksander B. , Evans Donald M. , Bourret Edith , Yan Zewu , van Helvoort Antonius T. J. , Meier Dennis
Published: February 2021

Focused ion beam (FIB) and scanning electron microscopy (SEM) are used to reversibly switch improper ferroelectric domains in the hexagonal manganite ErMnO3. Surface charging is achieved by local ion (positive charging) and electron (positive and negative charging) irradiation, which allows controlled polarization switching without the need for electrical contacts. Polarization cycling reveals that the domain walls tend to return to the equilibrium configuration obtained in the as-grown state. The response of sub-surface domains is studied by FIB cross-sectioning, enabling imaging in the direction perpendicular to the applied electric field. The results clarify how the polarization reversal in hexagonal manganites progresses at the level of domains, resolving both domain wall movements and the nucleation and growth of new domains. Our FIB-SEM based switching approach is applicable to all ferroelectrics where a sufficiently large electric field can be built up via surface charging, facilitating contact-free high-resolution studies of the domain and domain wall response to electric fields in 3D.
Guiding synthetic targets of anodically coloring electrochromes through density functional theory
Authors: Nhon Linda , Wilkins Riley , Reynolds John R. , Tomlinson Aimée
Published: February 2021

Electrochromic devices offer many technological applications, including flexible displays, dimmable mirrors, and energy-efficient windows. Additionally, adsorbing electrochromic molecular assemblies onto mesoporous metal-oxide surfaces facilitates commercial and manufacturing potential (i.e., screen-printing and/or roll-to-roll processing). These systems also demonstrate synthetic versatility, thus making a wide array of colors accessible. In this work, using Time-Dependent Density Functional Theory (TD-DFT), we investigated ten different bi-aryl type molecules of 3,4-ethylendioxythiophene (EDOT) conjugated to various phenyl derivatives as potential anodically coloring electrochromes (ACEs). The non-substituted phenylene, hexylthiol-EDOT-phenyl-phosphonic acid, PA1, was synthesized and characterized as a means of model validity. PA1 absorbs in the UV region in its neutral state and upon oxidation absorbs within the visible, hence showcasing its potential as an ACE chromophore. The properties of PA1 inspired the designs of the other nine structural derivatives where the number and position of methoxy groups on the phenylene were varied. Using our DFT treatment, we assessed the impact of these modifications on the electronic structures, geometries, and excited-state properties. In particular, we examined stabilization intermolecular interactions (S–O and O–H) as they aid in molecule planarization, thus facilitating charge transport properties in devices. Additionally, destabilizing O–O forces were observed, thereby making some chromophores less desirable. A detailed excited state analysis was performed, which linked the simulated UV-Vis spectra to the dominant excited state transitions and their corresponding molecular orbitals. Based on these results, the nine chromophores were ranked ergo providing an ordered list of synthetic targets.
Low thermal conductivity in GeTe-based thermoelectric materials with additional activated carbon
Authors: Youn Jimin , Ryu Juhee , Kim Hyunji , Kihoi Samuel Kimani , Son In-Sik , Chun Sang-Eun , Yi Seonghoon , Lee Ho Seong
Published: February 2021

In order to improve the performance of thermoelectric materials, nanoinclusions are often used to enhance phonon scattering. In this study, activated carbon, which is porous and thus has a large surface area, was incorporated in GeTe-based materials to cause increased boundary phonon scattering. Carbon dispersed in grain boundaries resulted in improved thermal properties without significant deterioration in electrical properties. Due to the extrinsic addition of activated carbon, the lattice thermal conductivity decreased by 13.8% on average. A maximum dimensionless figure of merit of 1.66 was achieved at 723 K for the Ge0.9Sb0.1Te composition with additional activated carbon.
Magnetic anisotropy and spin scattering in (La2/3Sr1/3)MnO3/CaRuO3 bilayers
Authors: Balakrishnan Purnima P. , Lindgren Emily , Kane Margaret , Wisser Jacob J. , Suzuki Yuri
Published: February 2021

Complex ferromagnetic oxides have been identified as possible candidate materials for sources of spin currents. Here we study bilayers of ferromagnetic (La2/3Sr1/3)MnO3 (LSMO) and metallic CaRuO3 (CRO) on LSAT substrates as a model system for spin pumping. Ferromagnetic resonance (FMR) measurements of these bilayers show evidence of spin pumping across the interface in the form of an increase in Gilbert damping with the addition of CRO. FMR indicates that the presence of CRO modifies the magnetic anisotropy of the LSMO. By increasing CRO thickness, we find a reduction of the out-of-plane anisotropy and simultaneous rotation of the easy axis within the plane, from the ⟨110⟩ to ⟨100⟩ axis. The evolution of magnetic anisotropy determined by FMR disagrees with that measured by bulk SQUID magnetometry and is accompanied by structural distortions in the LSMO layer as measured by x-ray diffraction, thus suggesting a change in magnetic anisotropy attributed to structural distortions imposed on LSMO by CRO. These results suggest that while LSMO and CRO remain promising candidates for efficient pure spin current generation and detection, respectively, epitaxial integration of perovskites will cause additional changes which must be accounted for in spintronics applications.
Macrophages inhibit and enhance endometriosis depending on their origin
Authors: Hogg Chloe , Panir Kavita , Dhami Priya , Rosser Matthew , Mack Matthias , Soong Daniel , Pollard Jeffrey W. , Jenkins Stephen J. , Horne Andrew W. , Greaves Erin
Published: February 2021

Significance

Endometriosis is a chronic, incurable inflammatory disorder impacting 190 million women worldwide. Immune cells called macrophages are implicated in promoting endometriosis. Macrophages have different origins and their origin can dictate function. In this study we demonstrate that endometriotic lesion-resident macrophages are derived from the uterine lining (endometrium), the abdominal (peritoneal) cavity, and recruited bone-marrow precursors (monocytes). Endometriosis triggers continuous recruitment of monocytes that differentiate into macrophages that differ from those usually present within the peritoneal cavity. By depleting different populations, we demonstrate that endometrial macrophages are “proendometriosis” while monocyte-derived peritoneal macrophages are “antiendometriosis” acting to protect the cavity from lesion establishment. In the future, immune-based therapies may allow targeting of prodisease macrophages and/or harnessing of antiendometriosis macrophages in endometriosis.
SLFN11 promotes CDT1 degradation by CUL4 in response to replicative DNA damage, while its absence leads to synthetic lethality with ATR/CHK1 inhibitors
Authors: Jo Ukhyun , Murai Yasuhisa , Chakka Sirisha , Chen Lu , Cheng Ken , Murai Junko , Saha Liton Kumar , Miller Jenkins Lisa M. , Pommier Yves
Published: February 2021

Significance

Schlafen-11 (SLFN11) inactivation leads to chemoresistance of a broad range of DNA-damaging agents. We uncover an expanded Ataxia Telangiectasia- and Rad3-related (ATR)-mediated signaling network that overcomes chemoresistance by an unbiased genome-wide RNAi screen in
SLFN11
-knockout cells and is validated with clinically developing ATR/CHK1 inhibitors. ATR inhibition induces CDT1 phosphorylation, leading to mitotic catastrophe cell death in SLFN11-deficient cells. We identify a key role of SLFN11 for CDT1 degradation by binding to DDB1–CUL4
CDT2
ubiquitin ligase during DNA damage, thereby blocking replication reactivation by which SLFN11-deficient cells cause chemoresistance. Our findings provide a rationale for combination therapy with ATR inhibitor and DNA-targeted drugs, and reveal how SLFN11 irreversibly arrests replication during DNA damage acting as a cofactor of CUL4
CDT2
ubiquitin ligase.
Competitive history shapes rapid evolution in a seasonal climate
Authors: Grainger Tess Nahanni , Rudman Seth M. , Schmidt Paul , Levine Jonathan M.
Published: February 2021

Significance

Understanding species’ eco-evolutionary responses to novel competitive interactions and shifting thermal regimes has become essential under global change. However, we lack insight into these dynamics because experimental evolution studies often focus on populations of individual species. Using a large-scale field experiment with two competing species of drosophilid flies, we show that rapid evolution in response to competition can alter a species’ evolutionary trajectory when exposed to a seasonally changing climate. Our results demonstrate that interactions with competitors, including invasive species, can shape evolution when climatic conditions change. More broadly, we provide empirical, field-based evidence that a legacy of recent adaptation can shape subsequent evolutionary trajectories.
ARMC12 regulates spatiotemporal mitochondrial dynamics during spermiogenesis and is required for male fertility
Authors: Shimada Keisuke , Park Soojin , Miyata Haruhiko , Yu Zhifeng , Morohoshi Akane , Oura Seiya , Matzuk Martin M. , Ikawa Masahito
Published: February 2021

Significance

Although formation of the mitochondrial sheath is a critical process in the formation of mature spermatozoa, the molecular mechanisms involved in mitochondrial sheath genesis remain unclear. Using gene-manipulated mice, we discovered that ARMC12 regulates spatiotemporal “sperm mitochondrial dynamics” during mitochondrial sheath formation through interactions with mitochondrial proteins MIC60, VDAC2, and VDAC3 as well as testis-specific proteins TBC1D21 and GK2. In addition, we demonstrated that ARMC12-interacting proteins TBC1D21 and GK2 are also essential for mitochondrial sheath formation. Our paper sheds light on the molecular mechanisms of mitochondrial sheath formation and the regulation of sperm mitochondrial dynamics, allowing us to further understand the biology of spermatogenesis and the etiology of infertility in men.
Mapping proteolytic neo-N termini at the surface of living cells
Authors: Weeks Amy M. , Byrnes James R. , Lui Irene , Wells James A.
Published: February 2021

Significance

Cell surface proteolysis is a key mechanism for cell-cell communication and cellular signaling that is commonly dysregulated in human disease. Proteolytic cleavage events at the cell surface often evade detection by conventional proteomics methods owing to their low relative abundance compared to cytoskeletal and cytoplasmic proteins. Here we address this limitation by developing a new enzymatic tool, subtiligase-TM, for targeted mapping of cell surface proteolysis. We combine subtiligase-TM with quantitative proteomics to map proteolytic cleavage sites on the cell surface with single amino acid resolution. Based on the importance of cell surface proteolysis in human health and disease, subtiligase-TM opens up new opportunities for identifying biomarkers and therapeutic targets.
Comparative analysis of embryo proper and suspensor transcriptomes in plant embryos with different morphologies
Authors: Chen Min , Lin Jer-Young , Wu Xiaomeng , Apuya Nestor R. , Henry Kelli F. , Le Brandon H. , Bui Anhthu Q. , Pelletier Julie M. , Cokus Shawn , Pellegrini Matteo , Harada John J. , Goldberg Robert B.
Published: February 2021

Significance

How plant embryos are differentiated into embryo proper and suspensor regions following fertilization is a major unanswered question. The suspensor is unique because it can vary in morphology in different plant species. We hypothesized that regulatory genes controlling the specification of embryo proper and suspensor regions should be shared by all plants irrespective of embryo morphology. We compared embryo proper and suspensor transcriptomes of plants with distinct suspensor morphologies. Scarlet runner bean and common bean have highly specialized giant suspensor regions; soybean and
Arabidopsis
suspensors are smaller and less specialized. We uncovered a small set of embryo proper– and suspensor-specific transcription factors shared by all embryos irrespective of morphology, suggesting that they play an important role in early embryo differentiation.
The more you move, the more action you construct
Authors: Jantunen Tommi , De Weerdt Danny , Burger Birgitta , Puupponen Anna
Published: February 2021

This paper investigates, with the help of motion capture data processed on corpus principles, the characteristics
of head and upper-torso movements in constructed action and regular narration (i.e., signing without constructed action) in FinSL.
Specifically, the paper evaluates the validity of two arguments concerning constructed action: that constructed action forms a
continuum with regular narration, and that constructed action divides into three subtypes (i.e., overt, reduced, and subtle). The
results presented in the paper support the first argument but not directly the second one. Because of the ambiguous position of
reduced constructed action in between subtle and overt constructed action, we argue in the paper that the present three-part
typology of constructed action may need revising. As an alternative way of subcategorizing the phenomenon we propose a division
between strong and weak constructed action.
Pattern replication and extraction from spatial PPs in Molise Slavic
Authors: Quaglia Stefano
Published: February 2021

This paper investigates P-stranding under A′-extraction in spatial PPs in Molise Slavic (MSL). After showing that P-stranding bijectively correlates with dative case on the Ground argument of P, I argue that the cases of extraction at stake instantiate grammatical convergence in the form of “pattern replication” (Matras & Sakel 2007). A′-extraction is licensed by the presence of borrowed additional functional material valuing and interpreting K(ase). The richer structure allows for KP to move out of the PP Phase without violating Anti-Locality. Both Italian and MSL secondary Ps displaying P-stranding are characterized as instantiating one of two possible structural options for P-stranding. The alternative structure is argued to be instantiated in Germanic, consistently with existing proposals (Abels 2012). The choice between the two options, as well as the productivity of the selected option in a given grammatical system, is a matter of (micro-)variation in the availability of functional vocabulary.