bluuebunny/crossref_metadata_2025 huggingface dataset:
Crippling life support for SARS-CoV-2 and other viruses through synthetic lethality
Authors: Mast Fred D. , Navare Arti T. , van der Sloot Almer M. , Coulombe-Huntington Jasmin , Rout Michael P. , Baliga Nitin S. , Kaushansky Alexis , Chait Brian T. , Aderem Alan , Rice Charles M. , Sali Andrej , Tyers Mike , Aitchison John D.
Published: December 2020

With the rapid global spread of SARS-CoV-2, we have become acutely aware of the inadequacies of our ability to respond to viral epidemics. Although disrupting the viral life cycle is critical for limiting viral spread and disease, it has proven challenging to develop targeted and selective therapeutics. Synthetic lethality offers a promising but largely unexploited strategy against infectious viral disease; as viruses infect cells, they abnormally alter the cell state, unwittingly exposing new vulnerabilities in the infected cell. Therefore, we propose that effective therapies can be developed to selectively target the virally reconfigured host cell networks that accompany altered cellular states to cripple the host cell that has been converted into a virus factory, thus disrupting the viral life cycle.
Geodesics near a curvature singularity of stationary and axially symmetric space–times
Authors: Del Águila Juan Carlos , Matos Tonatiuh
Published: December 2020

In this work we study the local behavior of geodesics in the neighborhood of a curvature singularity contained in stationary and axially symmetric space–times. Apart from these properties, the metrics we shall focus on will also be required to admit a quadratic first integral for their geodesics. In particular, we search for the conditions on the geometry of the space–time for which null and time-like geodesics can reach the singularity. These conditions are determined by the equations of motion of a freely-falling particle. We also analyze the possible existence of geodesics that do not become incomplete when encountering the singularity in their path. The results are stated as criteria that depend on the inverse metric tensor along with conserved quantities such as energy and angular momentum. As an example, the derived criteria are applied to the Plebański–Demiański class of space–times. Lastly, we propose a line element that describes a wormhole whose curvature singularities are, according to our results, inaccessible to causal geodesics.
Aluminum–silicon interdiffusion in silicon heterojunction solar cells with a-Si:H(i)/a-Si:H(n/p)/Al rear contacts
Authors: Bryan Jonathan L , Carpenter III Joe V , Yu Zhengshan J , Leilaeioun Ashling (Mehdi) , Shi Jianwei , Weigand William , Fisher Kathryn C , Holman Zachary C
Published: December 2020

We characterize a-Si:H(i)/a-Si:H(n)/Al and a-Si:H(i)/a-Si:H(p)/Al contacts implemented on the rear side of silicon heterojunction solar cells. Electrical test structures and full-area solar cells employing these contacts demonstrate promising performance. For example, a-Si:H(i)/a-Si:H(p)/Al test structures with a 40 nm thick a-Si:H(p) layer that were annealed at 180 °C had contact resistivities of 48 mΩ · cm2 and implied open-circuit voltage losses after metallization of only 9 mV. Similarly, solar cells with full-area rear a-Si:H(i)/a-Si:H(n)/Al contacts that were annealed at 150 °C had open-circuit voltages of 717 mV and contact resistivities of 9.4 mΩ · cm2. For thinner doped a-Si:H layers and higher annealing temperatures, the contacts become less stable and performance degrades. Complementary transmission electron microscopy and energy-dispersive x-ray spectroscopy analysis show the Al–Si interactions at these interfaces that explain the range of exhibited performance. This analysis leads to a better understanding of the materials properties limiting the contact stability.
Néel ordering in the distorted honeycomb pyrosilicate: C–Er2Si2O7
Authors: Hester Gavin , DeLazzer T N , Lim S S , Brown C M , Ross K A
Published: December 2020

The rare-earth pyrosilicate family of compounds (RE2Si2O7) hosts a variety of polymorphs, some with honeycomb-like geometries of the rare-earth sublattices, and the magnetism has yet to be deeply explored in many of the cases. Here we report on the ground state properties of C–Er2Si2O7. C–Er2Si2O7 crystallizes in the C2/m space group and the Er3+ atoms form a distorted honeycomb lattice in the a–b plane. We have utilized specific heat, DC susceptibility, and neutron diffraction measurements to characterize C–Er2Si2O7. Our specific heat and DC susceptibility measurements show signatures of antiferromagnetic ordering at 2.3 K. Neutron powder diffraction confirms this transition temperature and the relative intensities of the magnetic Bragg peaks are consistent with a collinear Néel state in the magnetic space group C2’/m, with ordered moment of 6.61 μ

B
canted 13° away from the c-axis toward the a-axis. These results are discussed in relation to the isostructural quantum dimer magnet compound Yb2Si2O7.
A facile and low-cost Al2O3 coating as an artificial solid electrolyte interphase layer on graphite/silicon composites for lithium-ion batteries
Authors: Zhu Hongzheng , Shiraz Mohammad Hossein Aboonasr , Liu Liang , Hu Yuhai , Liu Jian
Published: December 2020

Graphite/silicon (G/Si) composites are considered as possible alternative anode materials to commercial graphite anodes. However, the unstable solid electrolyte interphase (SEI) on G/Si particles results in rapid capacity decay, impeding practical applications. Herein, a facile and low-cost Al2O3 coating was developed to fabricate stable artificial SEI layers on G/Si composites. The amorphous Al2O3 coating with a thickness of 10–15 nm was synthesized by a simple sol–gel method followed by high-temperature annealing. The Al2O3 coated G/Si anode delivers an initial discharge capacity of 540 mAh g−1 at 25 °C and has improved Coulombic efficiency and cycling stability. After 100 cycles, the capacity retention is 76.4%, much higher than the 56.4% of the uncoated anode. Furthermore, the Al2O3 coating was found to be more effective at improving the stability of G/Si at a higher temperature (55 °C). This was explained by the Al2O3 coating suppressing the growth of SEI on Si/G and thus reducing the charge transfer resistance at the G/Si–electrolyte interface. It is expected that the Al2O3 coating prepared by the sol–gel process can be applied to other Si-based anodes in the manufacture of practical high-performance lithium-ion batteries.
Tension–compression behavior in gold nanoparticle arrays: a molecular dynamics study
Authors: Valencia Felipe J , Amigo Nicolás , Bringa Eduardo M
Published: December 2020

The mechanical properties of Au nanoparticle arrays are studied by tensile and compressive deformation, using large-scale molecular dynamics simulations which include up to 16 million atoms. Our results show that mechanical response is dominated by nanoparticle size. For compression, strength versus particle size shows similar trends in strength than full-density nanocrystals. For diameters (d) below 10 nm there is an inverse Hall–Petch (HP) regime. Beyond a maximum at 10 nm, strength decreases following a HP d
−1/2 dependence. In both regimes, interparticle sliding and dislocation activity play a role. The array with 10 nm nanoparticles showed the same mechanical properties than a polycrystalline bulk with the same grain size. This enhanced strength, for a material nearly 20% lighter, is attributed to the absence of grain boundary junctions, and to the array geometry, which leads to constant flow stress by means of densification, nanoparticle rotation, and dislocation activity. For tension, there is something akin to brittle fracture for large grain sizes, with NPs debonding perpendicular to the traction direction. The Johnson–Kendall–Roberts contact theory was successfully applied to describe the superlattice porosity, predicting also the array strength within 10% of molecular dynamics values. Although this study is focused on Au nanoparticles, our findings could be helpful in future studies of similar arrays with NPs of different kinds of materials.
Ce, Eu incorporation through doping of ALD-ZnO thin films for enhancing their photoluminescent properties
Authors: Cervantes-López J L , Rangel R , Meneses-Rodríguez D , Rodríguez-Gattorno G , Alvarado-Gil J J
Published: December 2020

Nanostructured ZnO nanoarrays deposited on silicon oriented substrates is a very promising area in the study of the control of physicochemical properties, in which photoluminescence plays a crucial role. This optical property inherent to ZnO, can be favorably modified through the inclusion of doping elements, with the purpose of appropriately modifying their optical absorption and luminescence. Following this objective, in the present work we present the development of Zn(1−x–y)Ce(x)Eu(y)O nanostructured thin films. The samples were produced in two steps process by atomic layer deposition technique followed by a solvothermal synthesis. The purpose of Cerium and Europium incorporation into the ZnO compound is to enhance the photoluminescence in ZnO thin films. In a first stage textured thin films were obtained from diethylzinc at a temperature of 190 °C and a pressure of 3.29 × 10−4 atm, on silicon substrates (111). Subsequently, the perpendicular growth of nanostructures was induced under a solvothermal process, where Zn(NO3)2 was used as Zn precursor and hexamethylene-tetramine operating as a dual-ligand to promote the linking of Zn2+ ions. The growth of cerium-europium ZnO nanostructures was promoted with Ce(C2H3O2)3·H2O and Eu(NO3)3·5H2O. The obtained Zn(1–x–y)Ce(x)Eu(y)O nanostructured thin films, were examined through SEM-microscopy, x-ray diffraction, x-ray photoelectron spectroscopy and photoluminescence studies. The attained results show that it is feasible to produce Ce–Eu-doped ZnO nanostructures with tailored photoluminescence and crystal size. Interestingly the Ce–Eu doping induces a strong shift in comparison to the typical UV emission of ZnO; an effect that can be related with the increase of lattice defects in ZnO.
Robust radiation therapy optimization using simulated treatment courses for handling deformable organ motion
Authors: Fredriksson Albin , Engwall Erik , Andersson Björn
Published: December 2020

We describe a radiation therapy treatment plan optimization method that explicitly considers the effects of interfraction organ motion through optimization on the clinical target volume (CTV), and investigate how it compares to conventional planning using a planning target volume (PTV). The method uses simulated treatment courses generated using patient images created by a deformable registration algorithm to replicate the effects of interfraction organ motion, and performs robust optimization aiming to achieve CTV coverage under all simulated treatment courses. The method was applied to photon-mediated treatments of three prostate cases and compared to conventional, PTV-based planning with margins selected to achieve similar CTV coverage as the robustly optimized plans. Clinical goals for the CTV and healthy tissue were used in comparison between the two types of plans. Out of the two clinical goals for overdosage of the CTV, the three robustly optimized plans violated respectively 2, 2, and 0 goals in the mean over the scenarios, whereas none of the PTV plans violated these goals. Of the ten clinical goals for rectum, bladder, anal canal, and bulbus, the robustly optimized plans violated respectively 0, 1, and 1 goals in the mean, whereas the PTV plans violated 5, 7, and 4 goals. Compared to PTV-based planning, the inclusion of treatment course scenarios in the optimization has the potential to reduce the dose to healthy tissues while retaining a high probability of target coverage. This may reduce the need for adaptive replanning.
Fat and fibrosis as confounding cofactors in viscoelastic measurements of the liver
Authors: Poul S S , Parker K J
Published: December 2020

Elastography provides significant information on staging of fibrosis in patients with liver disease and may be of some value in assessing steatosis. However, there remain questions as to the role of steatosis and fibrosis as cofactors influencing the viscoelastic measurements of liver tissues, particularly shear wave speed (SWS) and shear wave attenuation (SWA). In this study, by employing the theory of composite elastic media as well as two independent experimental measurements on oil-in-gelatin phantoms and also finite element simulations, it is consistently shown that fat and fibrosis jointly influence the SWS and SWA measurements. At a constant level of fat, fibrosis stages can influence the SWA by factors of 2–4. Moreover, the rate of increase in SWA with increasing fat is strongly influenced by the stages of fibrosis; softer background cases (low fibrosis stages) have higher rate of SWA increase with fat than those with stiffer moduli (higher fibrosis stages). Meanwhile, SWS results are influenced by the presence of fat, however the degree of variability is more subtle. The results indicate the importance of jointly considering fat and fibrosis as contributors to SWS and SWA measurements in complex liver tissues and in the design and interpretation of clinical trials.
Magnetic resonance shear wave elastography using transient acoustic radiation force excitations and sinusoidal displacement encoding
Authors: Hofstetter Lorne W , Odéen Henrik , Bolster Bradley D , Christensen Douglas A , Payne Allison , Parker Dennis L
Published: December 2020

A magnetic resonance (MR) shear wave elastography technique that uses transient acoustic radiation force impulses from a focused ultrasound (FUS) transducer and a sinusoidal-shaped MR displacement encoding strategy is presented. Using this encoding strategy, an analytic expression for calculating the shear wave speed in a heterogeneous medium was derived. Green’s function-based simulations were used to evaluate the feasibility of calculating shear wave speed maps using the analytic expression. Accuracy of simulation technique was confirmed experimentally in a homogeneous gelatin phantom. The elastography measurement was compared to harmonic MR elastography in a homogeneous phantom experiment and the measured shear wave speed values differed by less than 14%. This new transient elastography approach was able to map the position and shape of inclusions sized from 8.5 to 14 mm in an inclusion phantom experiment. These preliminary results demonstrate the feasibility of using a straightforward analytic expression to generate shear wave speed maps from MR images where sinusoidal-shaped motion encoding gradients are used to encode the displacement-time history of a transiently propagating wave-packet. This new measurement technique may be particularly well suited for performing elastography before, during, and after MR-guided FUS therapies since the same device used for therapy is also used as an excitation source for elastography.
Correlation of critical current density to quasi-biaxial texture and grain boundary cleanliness in fully dense Bi-2212 wires
Authors: Oloye T A , Matras M , Jiang J , Hossain S I , Su Y , Trociewitz U P , Hellstrom E E , Larbalestier D C , Kametani F
Published: December 2020

The distinctive quasi-biaxial texture of Bi2Sr2CaCu2O
x
(Bi-2212) plays an important role in enabling high critical current density (J
c) in Bi-2212 round wires (RWs). Here we studied three over pressure heat treated wires with J
c varying by a factor of ∼10, all being fully dense. Using electron backscatter diffraction, we observed the differences in biaxial texture in these three wires. Transmission electron microscopy also revealed differences in grain boundary (GB) cleanliness and connectivity. These analyses showed that high J
c is unambiguously correlated to the best biaxial texture, which is in turn correlated to slow cooling from the liquid melt into solid Bi-2212. However, at 4.2 K, there is a negligible difference in intragrain pinning in the three wires, suggesting that the J
c variation by a factor of ∼10 is primarily due to variable filament and intergrain connectivity. The principal determinants of intergrain connectivity is the quasi-biaxial texture and GB cleanliness. Overall, J
c optimization of the Bi-2212 RW is a complex multi-variable process, but this study shows that maximizing the biaxial texture quality is an important first step in such an optimization process.
Wolves choose ambushing locations to counter and capitalize on the sensory abilities of their prey
Authors: Gable Thomas D , Homkes Austin T , Johnson-Bice Sean M , Windels Steve K , Bump Joseph K
Published: December 2020

Comprehensive knowledge of ambush behavior requires an understanding of where a predator expects prey to be, which is generally unknowable because ambush predators often hunt mobile prey that exhibit complex, irregular, or inconspicuous movements. Wolves (Canis lupus) are primarily cursorial predators, but they use ambush strategies to hunt beavers (Castor canadensis). Terrestrial beaver activity is predictable because beavers use well-defined, conspicuous habitat features repeatedly. Thus, studying where wolves wait-in-ambush for beavers provides a unique opportunity to understand how predators choose ambush locations in relation to prey activity. We searched 11 817 clusters of GPS locations from wolves in the Greater Voyageurs Ecosystem, International Falls, MN, and documented 748 ambushing sites and 214 instances where wolves killed beavers. Wolves chose ambush locations: 1) with olfactory concealment to avoid detection from the highly developed olfactory senses of beavers and 2) close (generally <5 m) to beaver habitat features to take advantage of beavers’ inability to visually detect motionless predators. Our work describes in detail the ambush strategies wolves use to hunt beavers and continues to overturn the traditional notion that wolves rely solely on cursorial hunting strategies. We also demonstrate that ambush predators can anticipate the movements and behavior of their prey due to a fundamental understanding of their prey’s sensory abilities. Wolves, therefore, and likely ambush predators in general, appear capable of simultaneously accounting for abiotic and biotic factors when choosing ambush locations, ultimately allowing them to counter and capitalize on the sensory abilities of their prey.
Bisphenols alter thermal responses and performance in zebrafish (Danio rerio)
Authors: Wu Nicholas C , Seebacher Frank
Published: December 2020

Plastic pollutants are novel environmental stressors that are now persistent components of natural ecosystems. Endocrine disrupting chemicals such as bisphenols that leach out of plastics can modify physiological responses of animals by interfering with hormone signalling. Here, we tested whether three commonly produced bisphenols, bisphenol A (BPA), bisphenol F (BPF) and bisphenol S (BPS), impair thermal acclimation of swimming performance and metabolic enzyme [citrate synthase (CS) and lactate dehydrogenase (LDH)] activities in adult zebrafish (Danio rerio). We found that exposure to 30-μg l−1 BPF and BPS, but not BPA, reduced swimming performance, and no interactions between bisphenol exposure and acclimation (3 weeks to 18°C and 28°C) or acute test (18°C and 28°C) temperatures were found. BPA interacted with acclimation and acute test temperatures to determine CS activity, an indicator of mitochondrial density and aerobic metabolic capacity. BPS reduced CS activity and an interaction (at a one-tailed significance) between acclimation temperature and BPF exposure determined CS activity. LDH activity reflects anaerobic ATP production capacity, and BPA and BPF altered the effects of thermal acclimation and acute test temperatures on LDH activity. Our data show that all bisphenols we tested at ecologically relevant concentrations can disrupt the thermal responses of fish. BPS and BPF are used as environmentally safer alternatives to BPA, but our data show that these bisphenols are also of concern, particularly in thermally variable environments.
Enrichment of loss-of-function and copy number variants in ventricular cardiomyopathy genes in ‘lone’ atrial fibrillation
Authors: Lazarte Julieta , Laksman Zachary W , Wang Jian , Robinson John F , Dron Jacqueline S , Leach Emma , Liew Janet , McIntyre Adam D , Skanes Allan C , Gula Lorne J , Leong-Sit Peter , Cao Henian , Trost Brett , Scherer Stephen W , Hegele Robert A , Roberts Jason D
Published: December 2020

Aims

Atrial fibrillation (AF) is a complex heritable disease whose genetic underpinnings remain largely unexplained, though recent work has suggested that the arrhythmia may develop secondary to an underlying atrial cardiomyopathy. We sought to evaluate for enrichment of loss-of-function (LOF) and copy number variants (CNVs) in genes implicated in ventricular cardiomyopathy in ‘lone’ AF.

Methods and results

Whole-exome sequencing was performed in 255 early onset ‘lone’ AF cases, defined as arrhythmia onset prior to 60 years of age in the absence of known clinical risk factors. Subsequent evaluations were restricted to 195 cases of European genetic ancestry, as defined by principal component analysis, and focused on a pre-defined set of 43 genes previously implicated in ventricular cardiomyopathy. Bioinformatic analysis identified 6 LOF variants (3.1%), including 3 within the TTN gene, among cases in comparison with 4 of 503 (0.80%) controls [odds ratio: 3.96; 95% confidence interval (CI): 1.11–14.2; P = 0.033]. Further, two AF cases possessed a novel heterozygous 8521 base pair TTN deletion, confirmed with Sanger sequencing and breakpoint validation, which was absent from 4958 controls (P = 0.0014). Subsequent cascade screening in two families revealed evidence of co-segregation of a LOF variant with ‘lone’ AF.

Conclusion

‘Lone’ AF cases are enriched in rare LOF variants from cardiomyopathy genes, findings primarily driven by TTN, and a novel TTN deletion, providing additional evidence to implicate atrial cardiomyopathy as an AF genetic sub-phenotype. Our results also highlight that AF may develop in the context of these variants in the absence of a discernable ventricular cardiomyopathy.
Quality assessment of real-world data repositories across the data life cycle: A literature review
Authors: Liaw Siaw-Teng , Guo Jason Guan Nan , Ansari Sameera , Jonnagaddala Jitendra , Godinho Myron Anthony , Borelli Alder Jose , de Lusignan Simon , Capurro Daniel , Liyanage Harshana , Bhattal Navreet , Bennett Vicki , Chan Jaclyn , Kahn Michael G
Published: December 2020

Objective

Data quality (DQ) must be consistently defined in context. The attributes, metadata, and context of longitudinal real-world data (RWD) have not been formalized for quality improvement across the data production and curation life cycle. We sought to complete a literature review on DQ assessment frameworks, indicators and tools for research, public health, service, and quality improvement across the data life cycle.

Materials and Methods

The review followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Databases from health, physical and social sciences were used: Cinahl, Embase, Scopus, ProQuest, Emcare, PsycINFO, Compendex, and Inspec. Embase was used instead of PubMed (an interface to search MEDLINE) because it includes all MeSH (Medical Subject Headings) terms used and journals in MEDLINE as well as additional unique journals and conference abstracts. A combined data life cycle and quality framework guided the search of published and gray literature for DQ frameworks, indicators, and tools. At least 2 authors independently identified articles for inclusion and extracted and categorized DQ concepts and constructs. All authors discussed findings iteratively until consensus was reached.

Results

The 120 included articles yielded concepts related to contextual (data source, custodian, and user) and technical (interoperability) factors across the data life cycle. Contextual DQ subcategories included relevance, usability, accessibility, timeliness, and trust. Well-tested computable DQ indicators and assessment tools were also found.

Conclusions

A DQ assessment framework that covers intrinsic, technical, and contextual categories across the data life cycle enables assessment and management of RWD repositories to ensure fitness for purpose. Balancing security, privacy, and FAIR principles requires trust and reciprocity, transparent governance, and organizational cultures that value good documentation.
Exposure to OFDI and regional labour markets: evidence for routine and non-routine jobs in Great Britain
Authors: Gagliardi Luisa , Iammarino Simona , Rodríguez-Pose Andrés
Published: December 2020

This article explores the role of subnational geography in the analysis of the consequences of Outward Foreign Direct Investment (OFDI) for workers performing different typologies of jobs. We qualify jobs according to their knowledge content, degree of tradability and response to agglomeration economies. While the former two dimensions are key to signal the intensity to OFDI exposure of different typologies of jobs, the latter contributes to explain the unequal spatial distribution of benefits and losses from OFDI in terms of job creation/destruction. We theorise areas that are more severely exposed to OFDI experience job losses in routine occupations, whereas they do not necessarily benefit from job creation in non-routine jobs. To test our hypothesis, we make use of a balanced panel dataset at the local labour market level, exploiting variations in OFDI exposure and in the job composition of local areas. Our findings—robust to numerous checks, including unobserved global and local trends—indicate that job losses concentrate in regions that were more exposed to OFDI based on their initial industry mix, and affect individuals performing mainly routine tasks. In these same areas, however, no significant effects are found when looking at job creation in non-routine occupations.
Age–metallicity dependent stellar kinematics of the Milky Way disc from LAMOST and Gaia
Authors: Wu Yaqian , Xiang Maosheng , Chen Yuqin , Zhao Gang , Bi Shaolan , Li Chengdong , Li Yaguang , Huang Yang
Published: December 2020

We investigate the stellar kinematics of the Galactic disc in 7 < R < 13 kpc using a sample of 118 945 red giant branch (RGB) stars from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and Gaia. We characterize the median, dispersion and skewness of the distributions of the three-dimensional stellar velocities, actions and orbital parameters across the age–metallicity and the disc R–Z plane. Our results reveal abundant but clear stellar kinematic patterns and structures in the age–metallicity and the disc R–Z plane. The most prominent features are the strong variations of the velocity, action and orbital parameter distributions from the young, metal-rich thin disc to the old, metal-poor thick disc; a number of smaller-scale structures (such as velocity streams, north–south asymmetries, and kinematic features of spiral arms) are clearly revealed. Particularly, the skewness of Vϕ and Jϕ reveals a new substructure at R ≃ 12 kpc and Z ≃ 0 kpc, possibly related to dynamical effects of spiral arms in the outer disc. We further study the stellar migration by analysing the stellar orbital parameters and stellar birth radii. The results suggest that the thick disc stars near the solar radii and beyond are mostly migrated from the inner disc of R ∼ 4−6 kpc as a result of their highly eccentrical orbits. Stellar migration resulting from dynamical processes with angular momentum transfer (churning) is prominent for both the old, metal-rich stars (outward migrators) and the young metal-poor stars (inward migrators). The spatial distribution in the R–Z plane for the inward migrators born at a Galactocentric radius of >12 kpc shows clear age stratifications, possibly evidence that these inward migrators are consequences of splashes triggered by merger events of satellite galaxies that have lasted the past few Gyr.
Correlating spectral and timing properties in the evolving jet of the microblazar MAXI J1836−194
Authors: Lucchini M , Russell T D , Markoff S B , Vincentelli F , Gardenier D , Ceccobello C , Uttley P
Published: December 2020

During outbursts, the observational properties of black hole X-ray binaries vary on time-scales of days to months. These relatively short time-scales make these systems ideal laboratories to probe the coupling between accreting material and outflowing jets as the accretion rate varies. In particular, the origin of the hard X-ray emission is poorly understood and highly debated. This spectral component, which has a power-law shape, is due to Comptonization of photons near the black hole, but it is unclear whether it originates in the accretion flow itself, or at the base of the jet, or possibly the interface region between them. In this paper, we explore the disc–jet connection by modelling the multiwavelength emission of MAXI J1836−194 during its 2011 outburst. We combine radio through X-ray spectra, X-ray timing information, and a robust joint-fitting method to better isolate the jet’s physical properties. Our results demonstrate that the jet base can produce power-law hard X-ray emission in this system/outburst, provided that its base is fairly compact and that the temperatures of the emitting electrons are subrelativistic. Because of energetic considerations, our model favours mildly pair-loaded jets carrying at least 20 pairs per proton. Finally, we find that the properties of the X-ray power spectrum are correlated with the jet properties, suggesting that an underlying physical process regulates both.
Co-formation of the thin and thick discs revealed by APOGEE-DR16 andGaia-DR2
Authors: Beraldo e Silva Leandro , Debattista Victor P , Nidever David , Amarante João A S , Garver Bethany
Published: December 2020

Since thin disc stars are younger than thick disc stars on average, the thin disc is predicted by some models to start forming after the thick disc had formed, around 10 Gyr ago. Accordingly, no significant old thin disc population should exist. Using 6D coordinates from Gaia-DR2 and age estimates from Sanders & Das, we select ∼24 000 old stars (${\tau \gt 10\mbox{$\, \mathrm{Gyr}$}}$, with uncertainties $\lesssim 15{{\ \rm per\ cent}}$) within $2\mbox{$\, \mathrm{kpc}$}$ from the Sun (full sample). A cross-match with APOGEE-DR16 (∼1000 stars) reveals comparable fractions of old chemically defined thin/thick disc stars. We show that the full sample pericentre radius (rper) distribution has three peaks, one associated with the stellar halo and the other two having contributions from the thin/thick discs. Using a high-resolution N-body + SPH simulation, we demonstrate that one peak, at $\mbox{$r_\mathrm{per}$}\approx 7.1\mbox{$\, \mathrm{kpc}$}$, is produced by stars from both discs that were born in the inner Galaxy and migrated to the Solar Neighbourhood. In the Solar Neighbourhood, ∼1/2 (∼1/3) of the old thin (thick) disc stars are classified as migrators. Our results suggest that thin/thick discs are affected differently by radial migration inasmuch as they have different eccentricity distributions, regardless of vertical scale heights. We interpret the existence of a significant old thin disc population as evidence for an early co-formation of thin/thick discs, arguing that clump instabilities in the early disc offer a compelling explanation for the observed trends.
Adapting active reflector technology for greater sensitivity and sky-coverage in FAST-like telescopes
Authors: Li Jian-Ling , Peng Bo , Jin Cheng-Jin , Li Hui , Strom Richard G , Liu Bin , Chai Xiao-Ming , Liu Li-Jia
Published: December 2020

The Five-hundred-meter Aperture Spherical radio Telescope (FAST), the largest single-dish radio telescope in the world, has implemented an innovative technology for its huge reflector, which changes the shape of the primary reflector from spherical to that of a paraboloid of 300-m aperture. Here, we explore how the current FAST sensitivity can potentially be further improved by increasing the illuminated area (i.e. the aperture of the paraboloid embedded in the spherical surface). Alternatively, the maximum zenith angle can be increased to give greater sky coverage by decreasing the illuminated aperture. Different parabolic apertures within the FAST capability are analyzed in terms of how far the spherical surface would have to move to approximate a paraboloid. The sensitivity of FAST can be improved by approximately 10 per cent if the aperture of the paraboloid is increased from 300 to 315 m. The parabolic aperture lies within the main spherical surface and does not extend beyond its edge. The maximum zenith angle can be increased to approximately 35º from $26{_{.}^{\circ}}4$, if we decrease the aperture of the paraboloid to 220 m. This would still give a sensitivity similar to the Arecibo 305-m radio telescope. Radial deviations between paraboloids of different apertures and the spherical surfaces of differing radii are also investigated. Maximum zenith angles corresponding to different apertures of the paraboloid are further derived. A spherical surface with a different radius can provide a reference baseline for shape-changing applied through active reflector technology to FAST-like telescopes.
Impact of the Coronavirus Disease 2019 Pandemic on Outpatient Antibiotic Prescriptions in the United States
Authors: Buehrle Deanna J , Nguyen M Hong , Wagener Marilyn M , Clancy Cornelius J
Published: December 2020

In April 2020, there were significant reductions in prescription fills of each of the 10 most prescribed outpatient antibiotics in the United States. Monthly azithromycin, amoxicillin-clavulanate, and levofloxacin fills did not rebound significantly from April through July 2020. Coronavirus disease 2019 had an immediate and sustained impact on US outpatient antibiotic prescribing.
On interacting higher-spin bosonic gauge fields in the BRST-antifield formalism
Authors: Sakaguchi Makoto , Suzuki Haruya
Published: December 2020

We examine interacting bosonic higher-spin gauge fields in the BRST-antifield formalism. Assuming that an interacting action $S$ is a deformation of the free action with a deformation parameter $g$, we solve the master equation $(S,S)=0$ from the lower orders in $g$. It is shown that, choosing a certain cubic interaction as the first-order deformation, we can solve the master equation and obtain an action containing all orders in $g$. The antighost number of the action obtained is less than or equal to two. Furthermore, we show that the action obtained is lifted to that of interacting bosonic higher-spin gauge fields on anti-de Sitter spaces.
Epidural Block Treatment on Postherpetic Neuralgia and Comorbid Spine Metastasis of Malignant Tumor: Two Cases of Report
Authors: Dai Jin-Yan , Hong An-Lan , Wang Yan
Published: December 2020

Introduction:

Postherpetic neuralgia (PHN) is a painful condition that occurs after herpes zoster skin lesions have subsided and that lasts for more than 1 month. PHN is usually difficult to treat.

We herein present two cases of PHN comorbid with spinal metastasis of a malignant tumor. Both patients responded well to an epidural block.

Case presentation:

Patient 1 was a 54-year-old woman who had PHN for 35 days. Patient 2 was a 74-year-old woman who had PHN for 65 days. Both patients were treated with an epidural block and found to have spinal metastasis from a malignant tumor.

Discussion:

The routinely used dermatological medications for the treatment of herpes zoster and PHN have slow and unsatisfactory analgesic effects. Epidural block treatment provides a new approach for patients who cannot tolerate or do not respond to these commonly used drugs. Physicians should pay special attention to patients who have a history of a malignant tumor or are suspected to have spinal disease. Computed tomography or magnetic resonance imaging of the spine is recommended for such patients, and epidural block treatment should be performed after a spinal tumor or other lesions have been excluded.

Conclusion:

Epidural block treatment provides a new approach for patients of herpes zoster or PHN, but the treatment should be performed after a spinal tumor or other spinal lesions have been excluded.
Novel survival nomograms for patients with lung metastatic clear cell renal cell carcinoma
Authors: Zhang Lei , Hou Guangdong , Gao Ming , Zheng Yu , Dun Xinlong , Hou Niuniu , Zheng Wanxiang , Yan Fei , Lu Jun , Meng Ping , Ju Dongen , Yuan Jiarui , Wei Di , Zhu Zheng , Wang Fuli , Yuan Jianlin
Published: December 2020

Survival heterogeneity is observed among renal cell carcinoma (RCC) patients with metastases in different organs. Moreover, almost all previous prognostic nomograms based on data from metastatic RCC patients did not take competing events, such as death from cerebrovascular and heart diseases, into account. We aimed to construct novel prognostic nomograms for patients with lung metastatic clear cell RCC (LMCCRCC).

Data of 712 non-Hispanic white LMCCRCC patients registered in the Surveillance, Epidemiology, and End Results database were retrospectively analyzed. Nomograms for predicting overall survival (OS) and disease-specific survival (DSS) were established using the Cox approach and Fine and Gray approach, respectively, and their performances were assessed using the concordance index (C-index), calibration plots, and an independent cohort comprising 181 Hispanic patients.

Sex, tumor grade, T stage, N stage, presence or absence of bone metastases, and presence or absence of brain metastases were independent predictors for both OS and DSS. Additionally, presence or absence of liver metastases was an independent predictor only for DSS. Meanwhile, age at diagnosis was independently associated with OS. The C-indexes of the nomograms were 0.702 for OS and 0.723 for DSS in internal validation. In external validation, the C-indexes were 0.700 for OS and 0.708 for DSS. Both internal and external calibration plots showed excellent consistency between the prediction and the observation.

The current study developed a novel nomogram for predicting individual OS in LMCCRCC patients. Moreover, we constructed an effective competing risk nomogram for predicting their individual DSS for the first time.
Effects of microvascular invasion on clinical outcomes after resection with curative intent for cholangiocarcinoma
Authors: Song Bo-Hye , Cha Boram , Park Jin-Seok , Jeong Seok , Lee Don Haeng
Published: December 2020

Surgery is the only curative treatment for cholangiocarcinoma, but even after surgery, survival rates are unsatisfactory. Recently, several reports have suggested microvascular invasion (MiVi) is associated with poor postoperative prognosis in hepatocellular carcinoma (HCC). We considered that MiVi might be associated with poor clinical outcomes in patients with surgically resectable cholangiocarcinoma.

The records of 91 patients who underwent resection with curative intent for cholangiocarcinoma at Inha University Hospital from 2007 to 2017 were comprehensively reviewed for clinicopathological characteristics, DFS, and overall survival (OS) relations between these factors and the presence of MiVi.

Forty-nine of the 91 study subjects had MiVi and 42 did not. Median overall survivals were 492 days in the MiVi group and 1008 days in the noMiVi group and median DFSs were 367 days and 760 days, respectively. Cumulative survival ratio and recurrence incidence rates were significantly different in the 2 groups (P = .012). Multivariable analysis showed the presence of MiVi was an independent risk factor of OS (hazard ratio [HR] 3.34; 95% confidence interval [CI], 1.40–7.97; P = .007).

Cholangiocarcinoma is known to have a poor prognosis. When microvascular invasion remains after surgery it is associated with poor clinical outcomes.
68Ga-FAPI PET/CT Versus 68Ga-DOTATATE PET/CT in the Evaluation of a Patient With Neuroendocrine Tumor
Authors: Kömek Halil , Gündoğan Cihan , Can Canan
Published: December 2020

68Ga-FAPI (fibroblast activation protein-specific inhibitor) PET/CT was performed in a 56-year-old man with multiple liver masses, which were confirmed grade 2 well-differentiated neuroendocrine tumors with liver Tru-Cut biopsy. With 68Ga-DOTATE PET/CT, primary tumor in the pancreas, multiple metastases in the liver and metastatic portocaval lymph node were detected. In 68Ga-FAPI PET/CT imaging performed for comparison, it was seen that metastatic lesions in the liver were distinguished much better because of low background activity, and the primary tumor and metastatic lymph node were clearly selected. This case suggested that FAPI-bounded radionuclides may be useful in the evaluation and targeted therapy of neuroendocrine tumors.
Alkalicaulis satelles gen. nov., sp. nov., a novel haloalkaliphile isolated from a laboratory culture cyanobacterium Geitlerinema species and proposals of Maricaulaceae fam. nov., Robiginitomaculaceae fam. nov., Maricaulales ord. nov. and Hyphomonadales ord. nov.
Authors: Kevbrin Vadim , Boltyanskaya Yulia , Koziaeva Veronika , Uzun Maria , Grouzdev Denis
Published: December 2020

A prosthecate bacterial strain, designated G-192T, was isolated from decaying biomass of a haloalkaliphilic cyanobacteriumGeitlerinemasp. Z-T0701. The cells were aerobic, Gram-negative, non-endospore-forming and dimorphic, occurring either as sessile bacteria with a characteristic stalk or as motile flagellated cells. The strain utilized a limited range of substrates, mostly peptonaceous, but was able to degrade whole proteins. Growth occurred at 5–46 °C (optimum, 35–40 °C), pH 7.3–10.3 (optimum, pH 8.0–9.0), 0–14 % NaCl (v/w; optimum, 2.0–6.0 %, v/w). The G+C content of the genomic DNA of strain G-192Twas 66.8%. Phylogenetic analysis of the 16S rRNA gene sequence revealed that strain G-192Tformed a distinct evolutionary lineage within the familyHyphomonadaceae. Strain G-192Tshowed the highest 16S rRNA sequence similarity toGlycocaulis profundiZYF765T(95.2%),Oceanicaulis stylophoraeGISW-4T(94.2%) andMarinicauda salinaWD6-1T(95.5%). The major cellular fatty acids (>5% of the total) were C18:1ω9c, C18:0and 11-methyl-C18:1ω7c. The major polar lipids were glycolipids and phospholipids. The only respiratory quinone was ubiquinone-10 (Q-10). Based on polyphasic results including phylogenomic data, the novel strain could be distinguished from other genera, which suggests that strain G-192Trepresents a novel species of a new genus, for which the nameAlkalicaulis satellesgen. nov., sp. nov. is proposed. The type strain is G-192T(=VKM B-3306T=KCTC 72746T). The strain is the first representative of the stalked bacteria associated with a haloalkaliphilic cyanobacterium. Based on phylogenomic indices and phenotypic data, it is proposed to evolve two novel familiesMaricaulaceaefam. nov. andRobiginitomaculaceaefam. nov. out of the current familyHyphomonadaceae. In addition, it is proposed to place the first two families in the novel orderMaricaulalesord. nov. and novel orderHyphomonadalesord. nov. is proposed to accommodate the familyHyphomonadaceae.
Using Administrative Data to Incorporate Age and Sex-Dependent Resource Use for COVID-19 Acute Care Resource Use Simulations in Ontario, Canada
Authors: Mac Stephen , Ximenes Raphael , Barrett Kali , Khan Yasin A. , Pechlivanoglou Petros , Rios Juan David , Naimark David , Sander Beate
Published: December 2020

As the COVID-19 pandemic has progressed, more local data has become available, enabling a more granular modeling approach. In March 2020, we developed a COVID-19 Resource Estimator (CORE) model to estimate the acute care resource use in Ontario, Canada. In this paper, we describe the evolution of CORE2.0 to incorporate age, sex, and time-dependent acute care resource use, length of stay, and mortality to simulate hospital occupancy. Demographics (e.g., age and sex) of infected cases are informed by 4-month averages between March-June, and July-October using 10-year age groups. The probability of hospitalization, ICU admission, and requiring mechanical ventilation are all age and sex-dependent. LOS for each acute care level ranges from 5.7 to 16.15 days in the ward, 6.5 to 10.7 days in the ICU without ventilation, and 14.8 to 21.6 days on the ventilator, depending on month of infection. We calibrated some LOS components to reported ward and ICU occupancy between June 15 and October 31, 2020. Furthermore, we demonstrate the use of CORE2.0 for a regional analysis of Region of Waterloo, Ontario, Canada to simulate the ward bed, ICU bed, and ventilator occupancies for 30 days starting December 2020 for three case trajectory scenarios. Moving forward, this model has become highly flexible and customizable to data updates, and can better inform acute care planning and public measures as the pandemic progresses.
Systematic review reveals multiple sexually antagonistic polymorphisms affecting human disease and complex traits
Authors: Harper Jon Alexander , Janicke Tim , Morrow Edward H.
Published: December 2020

An evolutionary model for sex differences in disease risk posits that alleles conferring higher risk in one sex may be protective in the other. These sexually antagonistic (SA) alleles are predicted to be maintained at frequencies higher than expected under purifying selection against unconditionally deleterious alleles, but there are apparently no examples in humans. Discipline-specific terminology, rather than a genuine lack of such alleles, could explain this disparity. We undertook a two-stage review of evidence for SA polymorphisms in humans using search terms from (i) evolutionary biology and (ii) biomedicine. While the first stage returned no eligible studies, the second revealed 51 genes with sex-opposite effects, 22 increased disease risk or severity in one sex but protected the other. Those with net positive effects occurred at higher frequencies. None were referred to as SA. Our review reveals significant communication barriers to fields as a result of discipline-specific terminology.
The role of changes in environmental quality in multitrait plastic responses to environmental and social change in the model microalgaChlamydomonas reinhardtii
Authors: Melero-Jiménez Ignacio J. , Flores-Moya Antonio , Collins Sinéad
Published: December 2020

Intraspecific variation plays a key role in species’ responses to environmental change; however, little is known about the role of changes in environmental quality (the population growth rate an environment supports) on intraspecific trait variation. Here, we hypothesize that intraspecific trait variation will be higher in ameliorated environments than in degraded ones. We first measure the range of multitrait phenotypes over a range of environmental qualities for three strains and two evolutionary histories ofChlamydomonas reinhardtiiin laboratory conditions. We then explore how environmental quality and trait variation affect the predictability of lineage frequencies when lineage pairs are grown in indirect co-culture. Our results show that environmental quality has the potential to affect intraspecific variability both in terms of the variation in expressed trait values, and in terms of the genotype composition of rapidly growing populations. We found low phenotypic variability in degraded or same-quality environments and high phenotypic variability in ameliorated conditions. This variation can affect population composition, as monoculture growth rate is a less reliable predictor of lineage frequencies in ameliorated environments. Our study highlights that understanding whether populations experience environmental change as an increase or a decrease in quality relative to their recent history affects the changes in trait variation during plastic responses, including growth responses to the presence of conspecifics. This points towards a fundamental role for changes in overall environmental quality in driving phenotypic variation within closely-related populations, with implications for microevolution.