bluuebunny/crossref_metadata_2025 huggingface dataset:
DeGaS-MC: Dense Gas Survey in the Magellanic Clouds
Authors: Galametz M. , Schruba A. , De Breuck C. , Immer K. , Chevance M. , Galliano F. , Gusdorf A. , Lebouteiller V. , Lee M. Y. , Madden S. C. , Polles F. L. , van Kempen T. A.
Published: September 2020

Context. Understanding the star-forming processes is key to understanding the evolution of galaxies. Investigating star formation requires precise knowledge of the properties of the dense molecular gas complexes where stars form and a quantification of how they are affected by the physical conditions to which they are exposed. The proximity, low metallicity, and wide range of star formation activity of the Large and Small Magellanic Clouds (LMC and SMC) make them prime laboratories to study how local physical conditions impact the dense gas reservoirs and their star formation efficiency.

Aims. The aim of the Dense Gas Survey for the Magellanic Clouds (DeGaS-MC) project is to expand our knowledge of the relation between dense gas properties and star formation activity by targeting the LMC and SMC observed in the HCO+(2−1) and HCN(2−1) transitions.

Methods. We carried out a pointing survey targeting two lines toward ∼30 LMC and SMC molecular clouds using the SEPIA180 instrument installed on the Atacama Pathfinder EXperiment (APEX) telescope. We performed a follow-up mapping campaign of the emission in the same transition in 13 star-forming regions. This first paper provides line characteristic catalogs and integrated line-intensity maps of the sources.

Results. HCO+(2−1) is detected in 20 and HCN(2−1) in 8 of the 29 pointings observed. The dense gas velocity pattern follows the line-of-sight velocity field derived from the stellar population. The three SMC sources targeted during the mapping campaign were unfortunately not detected in our mapping campaign but both lines are detected toward the LMC 30Dor, N44, N105, N113, N159W, N159E, and N214 regions. The HCN emission is less extended than the HCO+ emission and is restricted to the densest regions. The HCO+(2−1)/HCN(2−1) brightness temperature ratios range from 1 to 7, which is consistent with the large ratios commonly observed in low-metallicity environments. A larger number of young stellar objects are found at high HCO+ intensities and lower HCO+/HCN flux ratios, and thus toward denser lines of sight. The dense gas luminosities correlate with the star formation rate traced by the total infrared luminosity over the two orders of magnitude covered by our observations, although substantial region-to-region variations are observed.
Wie arbeitest du betätigungszentriert? – Unterricht mit Experteninterviews
Authors: Bräuter Theresa
Published: September 2020

Der Online-Unterricht während der Corona-Krise ermöglichte den Lernenden an der Medau-Schule in Coburg einen Theorie-Praxis-Transfer. Von erfahrenen Ergotherapeuten erfuhren sie, was betätigungszentriertes Denken und Vorgehen praktisch bedeutet. Ein Erfolg auf allen Ebenen – für Lernende und Lehrende.
Dental Care during COVID-19 Outbreak: A Web-Based Survey
Authors: Faccini Melissa , Ferruzzi Fernanda , Mori Aline Akemi , Santin Gabriela Cristina , Oliveira Renata Cristina , Oliveira Ricardo Cesar Gobbi de , Queiroz Polyane Mazucatto , Salmeron Samira , Pini Nubia Inocencya Pavesi , Sundfeld Daniel , Freitas Karina Maria Salvatore
Published: September 2020

Objective This survey aimed to assess the effects of coronavirus disease 2019 (COVID-19) on elective and urgency/emergency dental care and dentists concerned.

Materials and Methods A web-based survey was performed using Google forms questionnaire sent to dentists in Brazil. Questions included: personal information, type of dental care provided during quarantine, if emergencies increased, the dental office biosafety routine, among others. The levels of concern about the impact of quarantine on dental care and patient oral health conditions and the economic impact on dental practices were evaluated using a 0- to 10-point scale. Statistical analysis included descriptive, percentages, one-way ANOVA, Tukey, and chi-square tests.

Results During quarantine, 64.6% of the dentists attended only urgency/emergency treatments, while 26.1% maintained routine appointments, and 9.3% closed the dental offices. A higher percentage of dentists from the least affected states continued routine dental treatment; dentists were younger and presented a significantly lower level of concern about dental treatments and oral health conditions of their patients. An increase in urgency/emergency procedures was reported by 44.1% of the dentists, mostly due to the unavailability of routine/elective dental care and increased patient anxiety and stress. The main causes of urgency/emergency appointments were toothache, dental trauma, and broken restorations, besides the breakage of orthodontic appliances and temporomandibular disorders. Dentists reported a high level of concern about the economic impact caused by quarantine.

Conclusions The pandemic/quarantine has negatively affected the clinical routine. Personal protection/hygiene care must be adopted and reinforced by dental professionals/staff to make dental procedures safer.
Current Clinical Dental Practice Guidelines and the Financial Impact of COVID-19 on Dental Care Providers
Authors: Ali Saqib , Farooq Imran , Abdelsalam Maha , AlHumaid Jehan
Published: September 2020

The novel coronavirus disease 2019 (COVID-19) has been acknowledged as a pandemic by the World Health Organization (WHO). The aim of this study was to review guidelines issued by different health regulatory bodies amid the COVID-19 outbreak and financial constraints faced by dentists globally. Relevant papers and news articles were identified in Google Scholar and PubMed. The search was made using the keywords “COVID-19,” “COVID-19 and dentistry,” and “the financial impact of COVID-19 on dentistry.” Studies and news articles published in languages other than English were excluded and a final selection of 53 relevant studies, guideline documents, and news articles were made. The outbreak of COVID-19 has affected all businesses including general dental practices, which are suffering huge financial losses as they have been advised to provide only emergency dental care. These recommendations should be appreciated as a positive step but they have caused serious financial implications for dental practices. It can be concluded that current dental practice globally is limited to the provision of emergency treatments only. This step is appreciative, but has resulted in huge financial losses sustained by dental care providers (DCPs) worldwide. The governments and health regulatory bodies of developed countries are trying to help dental practices to evolve from this troublesome situation, but there is no visible policy from the underdeveloped world that could help the DCPs to save their practices from closing down due to the financial constraints.
The Retromolar Space and Wisdom Teeth in Humans: Reasons for Surgical Tooth Extraction
Authors: Kaseh Abed El , Shayeb Maher Al , Kuduruthullah Syed , Gulrez Nadeem
Published: September 2020

Objective This article explores the problem of developing pathologies in the retromolar region. Findings can serve a framework for disease prevention and for the improvement of the quality of life of patients. The present study aims to justify the possibility of utilizing morphometric methods to foresee problems in the eruption of third molars.

Materials and Methods A comprehensive morphometric study of the lower jaw and facial skeleton involves 100 skulls of Homo sapiens to identify the anatomical causes of problems with wisdom teeth eruption. All said skulls are divided in two groups: I: skulls with intact dentition; II: skulls with impacted third molars.

Results This work allows detecting abnormalities in the eruption of the third molar with high probability of success. The abnormalities in point are considered not only those associated with the generally accepted parameters but also those that occur in the leptoprosopic face cases.

Conclusions Face type and the structural features of the facial skeleton play a significant role in the abnormal eruption of the lower third molar.
Socioeconomic determinants of farm household land allocation for grass pea production in North Wollo Zone of Amhara region, Ethiopia
Authors: Damene Shimeles , Guta Dawit Diriba , Assen Mohammed , Satyal Poshendra
Published: September 2020

Grass pea (Lathyrus sativus) is widely cultivated and consumed in Ethiopia, where its overconsumption has caused cases of lathyrism. Despite this fact, there are limited empirical studies carried out in Ethiopia on the factors driving household decision to grow grass pea and intensity of land allocation to its production. Therefore, this study was focused on exploring the determinants of smallholder farmers’ land allocation to grass pea production in two districts of Ethiopian highlands. Household survey, focus group discussions and key informant interviews were used as data collection methods. These were followed by statistical analysis of quantitative data with SPSS and thematic analysis of qualitative data. The study used the Heckman selection model to investigate the determinants of household’s intensity of land use for grass pea production. The data revealed that farmers in the study area annually allocated about 26% of their farm plots size to grass pea production. Household’s landholding size, age of household head and the head’s primary school attendance have statistically significant and positive effect on the size of land allocation to grass pea production. Farmers also switched to grass pea production due to its tolerance to drought and waterlogged soils. These all encouraged grass pea production and consumption by humans, which has resulted in lathyrism in the study area. Household access to health and farm extension services had negative and statistically significant effect on land allocation to grass pea production. Based on the findings, it is concluded that better access to markets, educational opportunities, credit facilities, family planning and farm extension services are needed to increase household awareness on crop diversification and enhance technology uptake and financial capacity. Consequently, this can help local people reduce allocation of land to grass pea production and decrease its consumption, thereby preventing the risk of lathyrism incidence.
Concentrating, diverging, shifting, and splitting electromagnetic beams using a single conical structure
Authors: Barros Wallysson , Santos Antônio de Pádua , Pereira Erms
Published: September 2020

Bending, shifting, and splitting light rays are some of the basic operations in optics. A change of operation generally requires the device associated with a particular operation to be replaced by another one, resulting in delays. Here, we propose a structure that switches among bidirectional bending, shifting, and splitting of a light beam when rotating it. It is an anisotropic dielectric structure that makes light feel an effective asymmetric conical space. Such a system arises spontaneously in nematic liquid crystals, living liquid crystals, and active nematics and, in any case, can be realized with optical metamaterials. We numerically solve the wave equation to demonstrate bending, shifting, and splitting as noted above. When fabricated with liquid crystals, its functionality can vary with temperature.
Decreased clot debris size and increased efficiency of acoustic vortex assisted high intensity focused ultrasound thrombolysis
Authors: Guo Shifang , Wang Xin , Guo Xuyan , Ya Zhen , Wu Pengying , Bouakaz Ayache , Wan Mingxi
Published: September 2020

High intensity focused ultrasound (HIFU) thrombolysis is a non-pharmacological, non-invasive treatment option for the restoration of blood flow through occluded vessels. This study demonstrated that the combination of an acoustic vortex with HIFU thrombolysis can decrease the size of clot debris, while simultaneously increasing the thrombolysis efficiency. The detected stable and inertial cavitation doses were lower in acoustic vortex assisted HIFU thrombolysis than in HIFU thrombolysis alone or in HIFU thrombolysis combined with regular focused ultrasound. Additionally, optical images indicated that these positive effects can be attributed to the aggregation of the generated clot debris and cavitation microbubbles in the focal region. This effectively enhances the interaction between the microbubbles and the clot, as well as its debris. Furthermore, the proposed method was effective under a flow velocity of up to 6 cm/s. This study demonstrated that the combination of an acoustic vortex and HIFU may provide a safer and more efficient thrombolysis approach by decreasing the debris size and by increasing the efficiency.
Generalized thermoelastic effect in real metals and its application for describing photoacoustic experiments with Al membranes
Authors: Glazov A. L. , Muratikov K. L.
Published: September 2020

A generalized theoretical model of the formation of a thermoelastic photoacoustic signal from real materials is proposed taking into account the presence of defects and impurities. An effective coefficient of thermal expansion was introduced that describes the dilatation effect of thermally activated lattice irregularities. Expressions for the thermoelastic photoacoustic signal obtained in the linear approximation were applied to describe aluminum membrane vibrations at the periodic laser excitation measured in other studies using a gas-microphone open-cell photoacoustic technique. The proposed theoretical model allows us to explain the experimental results in the 20 Hz–7 kHz modulation frequency range without invoking the assumption of the bulk absorption of pump laser radiation in aluminum membranes.
Microwave (2ω1 − ω2) frequency mixing by mobile carriers in electron-doped and gapped graphene
Authors: Margulis Vl. A. , Muryumin E. E.
Published: September 2020

We theoretically study the generation of microwave radiation at frequency 2ω1−ω2, produced by two microwaves, of frequencies ω1 and ω2, normally incident on monolayer graphene grown epitaxially on a SiC substrate and doped by electrostatic gating. Two mechanisms responsible for this third-order nonlinear effect are considered: (i) the graphene’s conduction band nonparabolicity arising from the substrate-induced bandgap opening at the Dirac points of the graphene’s Brillouin zone and (ii) the energy dependence of the electron-momentum relaxation time. Both mechanisms are incorporated in our Boltzmann-equation-based treatment of the graphene’s third-order nonlinear response to the applied microwave radiation field. Within the framework of the approach, we evaluate the output power P2ω1−ω2 of the (2ω1−ω2) microwave radiation as a function of the graphene’s carrier density nS controlled by the applied gate voltage. Our formulation predicts an unexpected nonmonotonous behavior of this function: there is a pronounced minimum in the P2ω1−ω2(nS), which is followed by a maximum. This finding may serve to provide a rational explanation for this type of oscillation as observed by Dragoman et al. [Appl. Phys. Lett. 97, 093101 (2010)] in the output power of the microwave harmonic generation in gated graphene, which are not properly construed so far.
Direct electron bunch acceleration by Laguerre–Gauss laser pulse
Authors: Akou Hossein , Firouzjaei Ali Shekari
Published: September 2020

Acceleration of a rest electron bunch in vacuum by a Laguerre–Gauss (LG) laser pulse is studied using three-dimensional test-particle simulations. It is found that the ponderomotive force and the phase synchronization process, with the help of each other, cause rest electrons to reach high energies in the laser interaction. The ponderomotive force due to the spatial distribution of a high-intensity LG laser pulse pushes electrons from the rest and accelerates them at first. Then, the accelerated electrons are trapped in the pulse and continue to gain more energy through the phase synchronization process. Unlike the interaction with a Gaussian laser pulse in which to maintain the beam quality was not possible without the intervention of an external factor, using the LG laser pulse reveals the feasibility of generating a GeV high-quality electron bunch with low spread in energy and radial deflection, without applying any external agent.
Strain-engineering of bandgaps in pristine and fully hydrogenated hexagonal boron phosphide
Authors: Ma Keyan , Wang Hao , Wang Jian , Wang Qian
Published: September 2020

Based on density functional theory, the structural, electronic, and phonon properties of the pristine and three conformers of fully hydrogenated h-BP sheets are investigated. The results demonstrate that they are all dynamically stable because of no imaginary frequencies in their phonon spectra. The pristine h-BP sheet is a semiconductor with a direct bandgap of 1.377 eV calculated by Heyd–Scuseria–Ernzerhof (HSE06). The variation tendency of its bandgap vs uniaxial strains is very slow due to conduction band minimum and valence band maximum insensitive to strains. However, the uniaxial strain can effectively tune the bandgaps of the fully hydrogenated counterparts. An indirect to direct bandgap transition can occur in the chair conformer by adding a tiny x- or y-axial strain. A direct bandgap can remain in stirrup conformer no matter whether x-axial or y-axial strain is added. The HSE06 bandgap can be tuned in a wide range from 4.592 eV to 2.919 eV (chair), from 4.151 to 3.362 eV (boat), and from 4.344 eV to 3.134 eV (stirrup) in the range of 8% to −8%. The discussions above demonstrate that their bandgaps are controllable as long as the uniaxial strain is chosen in proper direction and size. Our findings suggest the great potential of a strain-engineered hydrogenated h-BP sheet in electronic and optoelectronic device applications.
Effect of co-flow velocity ratio on evolution of poly-disperse particles in coaxial turbulent jets: A large-eddy simulation study
Authors: Barve Anup V. , Sahu Srikrishna , Anupindi Kameswararao
Published: September 2020

In the present work, the particle-laden coaxial turbulent jet flow is studied using large-eddy simulation (LES). An Eulerian–Lagrangian framework is used to study the interaction between the continuous phase (air) and the discrete phase (glass bead particles). The solver is validated, using single-phase and particle-laden simulations, with reference data from experiments. A good match is observed between the present results and the reference data, for centerline velocity decay and radial profiles of axial velocity. Simulations are performed for three co-flow velocity ratios of 0, 1, and 1.5. The results pertaining to particle characteristics are presented for three different particle size-classes. The effect of the co-flow velocity ratio on the particle size–velocity correlation and velocity statistics of both phases are studied with an emphasis on understanding the differences in the particle dispersion due to co-flow around the central jet. It is observed that the particle size–velocity correlation is negative in the potential core region, and it becomes positive as one moves downstream. For heavy particles, the axial distance required to attain the same velocity as that of air increases with an increase in the co-flow velocity ratio. The size-conditioned particle number density profiles along the axial and radial directions of coaxial jets showed some interesting trends that could be explained based on the particle Stokes number effect. Significant radial dispersion of particles is realized when the corresponding Stokes number (StL), defined based on large-scale turbulent eddies, is of the order of one. The axial evolution of the characteristic particle size exhibited non-monotonic trends for all co-flow ratios. Overall, the present work demonstrates potential application of LES for an in-depth study of dispersion of poly-disperse particles in turbulent coaxial jets.
The variation of optical gain in Ge nanowires induced by the ΔEeΓ,L and symmetry of hole states under the axial stress
Authors: Xiong Wen , Gong Le-Le , Chen Wen-Suo , Wang Zi-Wu
Published: September 2020

The electronic structures of Ge nanowires at the direct Γ-valley and indirect L-valley are calculated under the axial sterss based on the effective-mass theory. The optical gain is also investigated, and strangely, the peak gain along the z direction almost does not change, while the peak gain along the x direction goes up rapidly as the stress increases. For the first time, we clarify the variation of the peak gain in detail via the decrease of a physical quantity ΔEeΓ,L in combination with the change of the symmetry of hole states under stress. Furthermore, the net peak gain of Ge nanowires with different diameters and axial stresses is calculated after considering the free-carrier absorption loss, and the results demonstrate that the positive net peak gain along the x direction can be achieved when the stress is up to 4 GPa.
BUILDING AND WORKING WITH ELECTROSTATIC EQUIPMENT
Authors: Morse Robert A.
Published: September 2020

When two materials with different affinities for positive and negative charges are rubbed together or separated, one may end up with an excess of negative charge and the other with an excess of positive charge, giving the materials net negative and positive charges. This will occur to some extent with any two materials, but the results may not be obvious unless the materials are good insulators. This process is called triboelectric charging,. The actual mechanisms of frictional or contact charging are complex and not fully understood, depending on the nature of the materials, surface impurities, moisture, etc. and may involve both motion of electrons and ions. The contact between dissimilar surfaces seems to be the important feature, with rubbing acting to increase the number of contact points.(See Cross, 1987, and Loeb, 1953, Horn and Smith, Science, 256(5055),362, Apr 17, 1992). Several experimenters have established lists of materials and their relative affinities for negative and positive charge when rubbed together. Such a list is called a triboelectric series. The example here is adapted from Graf (1964, p 37.) Once students have a reliable method for determining the sign of a charge (see Laboratory Activity Five) the construction of such a series using materials found in the classroom and the home can be an interesting independent investigation.
DEVICES, DEMONSTRATIONS AND DISPLAYS
Authors: Morse Robert A.
Published: September 2020

There are many interesting demonstrations dealing with electrostatics. Some of them are described in the following books:
Determinants
Authors: Swartz Clifford E.
Published: September 2020

In the section on simultaneous equations we noted that there is a special way to solve these using determinants. Determinants were widely studied in the last half of the nineteenth century in connection with matrices and linear algebra. Theoretical interest in them is no longer what it was then, but some practical applications are still very important.
Calculus—Differentiation
Authors: Swartz Clifford E.
Published: September 2020

Calculus is the mathematics of change. In the section on functions we emphasized the importance of the slope of the graph of each function. This slope, which is the tangent line to a point on the graph, determines the change of the function as the independent variable changes. The slope is defined algebraically as Δy/Δx. Since this ratio may depend on the size of the base interval, Δx, a strict definition requires the slope to be equal to the limit of the ratio as Δx goes to zero. Slope = limΔx→0 (Δy/Δx). For most of the points of functions dealt with in introductory science, such limits do exist. In the case illustrated, the limiting process produces a slope of 2.00 at x = 1, y = 1.
HEAT
Authors: Frier G. D. , Anderson F. J.
Published: September 2020

Thermometers which have various ranges and are filled with various liquids are shown to the student.
Introduction
Authors: Lotze Barbara
Published: September 2020

When asked about women’s contributions to the physical sciences, most laymen—and possibly even some physicists—may come up with two or three names: Marie Curie, Lise Meitner, and perhaps Maria Goeppert-Mayer. There are few extensive studies on the topic, with Margaret Rossiter’s Women Scientists in America still very much the exception. This realization prompted the Committee on Women in Physics of the American Association of Physics Teachers to sponsor a special session on “Women’s Role in Physics” at the 1983 summer meeting of the organization.
Student Assignments and Problems
Authors: Davids Mark , Rea R. Stephen , Zitzewitz Paul W.
Published: September 2020

This section will provide a place for you to record your observations, predictions, and answers to the questions and problems posed in the handbook (Section 3). Keep this section up-to-date as you read and perform the activities. Read all of the material! You will be asked to answer questions and solve numerical problems that are based on the reading. This section will be checked for accuracy, thoroughness, and completeness. Together with the lightwave quiz, it will determine your grade for this unit.
Laboratory Activities
Authors: Franklin Bill
Published: September 2020

For this experiment, you need three light sources, filters to convert them to red, green, and blue sources (the additive primary colors), and a white screen. There are commercial light boxes designed to facilitate color mixing, but you can also use overhead or slide projectors, floodlamps, or even flashlights. Overlap (add) all three spots as shown below and adjust their intensities to obtain white in the center. Label the unlabeled areas with the colors they appear. These should be magenta (a pink-purple about the color of azalea blossoms), cyan (also called turquoise or aquamarine), and yellow. Summarize your results in the table at the right.
Computer Applications
Authors: Franklin Bill
Published: September 2020

Computers were obviously heavily used in the production of this unit. Most of the work was done on Apple Macintosh computers, using ClarisWorks integrated software. The reflection and transmission graphs were drawn using a chart based on a spreadsheet. See 2D-9.
BACKGROUND MATERIAL (with transparency masters)
Authors: Reiland Robert J.
Published: September 2020

There are two situations in which electrically charged particles can experience forces in the presence of magnetic fields. The first occurs when an electrically charged object moves as an isolated particle, as can happen when it is moving in a vacuum or at high energy through a material medium. The second is a current in a wire or an ionic solution. The only significant differences between these are that wires and solutions tend to be electrically neutral while an isolated charged object is not, and that the free charges within wires and solutions can not usually move beyond the surfaces of the wires or the solutions while there may be no such boundaries for isolated charged objects.
DEMONSTRATIONS AND DISPLAYS
Authors: Reiland Robert J.
Published: September 2020

The following books describe demonstrations in magnetism. Most use relatively simple and available materials. For someone with a shop who loves to construct permanent displays Physics Demonstration Experiments is worth looking at. Although it is now out of print, check your library to look through a copy.
TECHNOLOGY USE FOR TEACHING MAGNETISM
Authors: Reiland Robert J.
Published: September 2020

PHYSICS: CINEMA CLASSICS - Disc 2/Side D now being sold by Ztek Co. (800-247-1603) includes parts of films on various topics including magnetism. The magnetism films were originally produced by the Encyclopaedia Britannica Education Corp. (EBEC), the Education Development Center, Inc. (EDC) which includes PSSC films, the Newton’s Apple television series and Phoenix Films and Video, Inc, (PF) which includes Project Physics films. Most of the film sequences are useful. All of them are short, and the entire set on magnetism can be reviewed in little more than an hour.
Scaling relationships for the elastic moduli and viscosity of mixed lipid membranes
Authors: Kelley Elizabeth G. , Butler Paul D. , Ashkar Rana , Bradbury Robert , Nagao Michihiro
Published: September 2020

Significance

Life requires a delicate balance between cell membrane rigidity and fluidity to define cell boundaries yet enable cell deformation, growth, and division. Here, we bridge the molecular and macroscopic scales with neutron scattering techniques to demonstrate how the material properties of model lipid membranes are readily tuned by the constituent lipid composition. Mixing lipids leads to softer and less viscous membranes than predicted a priori from the pure component membrane properties. Instead, the dynamics are linked to the membrane structure and follow simple scaling relationships with the area per molecule. These results emphasize the importance of lipid packing and reveal the interwoven relationship between lipid membrane structure and dynamics.
Type I IFNs and CD8 T cells increase intestinal barrier permeability after chronic viral infection
Authors: Labarta-Bajo Lara , Nilsen Steven P. , Humphrey Gregory , Schwartz Tara , Sanders Karenina , Swafford Austin , Knight Rob , Turner Jerrold R. , Zúñiga Elina I.
Published: September 2020

Intestinal barrier leakage constitutes a potential therapeutic target for many inflammatory diseases and represents a disease progression marker during chronic viral infections. However, the causes of altered gut barrier remain mostly unknown. Using murine infection with lymphocytic choriomeningitis virus, we demonstrate that, in contrast to an acute viral strain, a persistent viral isolate leads to long-term viral replication in hematopoietic and mesenchymal cells, but not epithelial cells (IECs), in the intestine. Viral persistence drove sustained intestinal epithelial barrier leakage, which was characterized by increased paracellular flux of small molecules and was associated with enhanced colitis susceptibility. Type I IFN signaling caused tight junction dysregulation in IECs, promoted gut microbiome shifts and enhanced intestinal CD8 T cell responses. Notably, both type I IFN receptor blockade and CD8 T cell depletion prevented infection-induced barrier leakage. Our study demonstrates that infection with a virus that persistently replicates in the intestinal mucosa increases epithelial barrier permeability and reveals type I IFNs and CD8 T cells as causative factors of intestinal leakage during chronic infections.
Effect of hardening on electrical and magnetic properties of C-75 steel and characterization with multi-frequency inductance spectroscopy
Authors: Munjal Rohan , Wendler Frank , Leonhardt André , Birnbaum Peter , Kräusel Verena , Kanoun Olfa
Published: September 2020

Non-destructive monitoring of metal hardness is important for process monitoring and product quality assessment. In this paper, a partially hardened metal sample is assessed in regards to physical effects using multi-frequency inductance spectroscopy. For this purpose, the influence of change of conductivity, permeability and stress on the inductance spectra are analyzed. To extract the numerical values of permeability, the measured inductance spectra are compared to the analytical inductance model. Statistical analysis with principal component analysis is conducted to fuse the spectral data into a single representative value. The results show the possibility to obtain information from different layers of the partially hardened sample, thus indicating a strong relationship between the measured inductance and restraint hardening.
Thermal conductivity and interfacial thermal resistance in the heterostructure of silicon/amorphous silicon dioxide: the strain and temperature effect
Authors: Gu Hanqing , Wang Jiuhong , Wei Xueyong , Wang Hairong , Li Zhibin
Published: September 2020

This article reports the thermal conduction properties of Si/a-SiO2 heterostructure with two different interfaces: weak and strong coupling strength through molecular dynamics simulation. The size and temperature dependencies on the interfacial thermal resistance of the weak coupling interface are larger than those of the strong coupling interface. The thermal conduction in Si/a-SiO2 shows strong anisotropy. The thermal conductivity, interfacial thermal resistance, and enhancement of the anisotropy can be modulated by changing the strains applied to the heterostructures. This work provides an optional way to design the silicon-based heterostructures considering heat insulation and heat dissipation.
A new phosphonium-based ionic liquid to synthesize nickel metaphosphate for hydrogen evolution reaction
Authors: Ying Hao , Zhang Chenyun , Chen Tingting , Zhao Xiaoning , Li Zhonghao , Hao Jingcheng
Published: September 2020

The electrochemical hydrogen evolution reaction (HER) is a promising strategy for production of hydrogen; however, it is still restricted by appropriate efficient and low-cost electrocatalysts. Herein, for the first time, the n-octylammonium hypophosphite, a kind of protic ionic liquid (IL), was used as a new phosphorus source for the manufacture of nickel metaphosphate (Ni2P4O12) electrocatalysts. In contrast to traditional multi-step fabrication processes, the n-octylammonium hypophosphite acted as both reactant and solvent to synthesize Ni2P4O12 by a one-step calcination approach. The obtained Ni2P4O12 as an alkaline HER catalyst required a low overpotential of 116 mV at −10 mA cm−2 and a small Tafel slope of 97 mV dec−1, comparable to the majority of reported Ni-based materials and other phosphate catalysts. Furthermore, this catalyst exhibited robust stability with no distinct attenuation of current density after a long-term durability test in 1 M KOH. Therefore, this task-specific IL strategy with a simple reaction system, reducing the occurrence of side reactions, provided a new perspective on design of high-efficiency metaphosphate electrocatalysts.
Temperature-dependent Raman modes of MoS2/MoSe2 van der Waals heterostructures
Authors: Öper Merve , Shehu Yahaya , Perkgöz Nihan Kosku
Published: September 2020

Two-dimensional (2D) monolayer transition metal dichalcogenides (TMDs) show extra-ordinary properties compared to their bulk forms, which has inspired a large number of researchers to investigate these materials recently. Design and fabrication of different combinations of 2D TMDs layers can allow for high-performance and novel heterostructure-based devices, of which the performance will depend also on their thermal properties. On the other hand, the temperature-dependent behavior of such heterolayers and their interaction at different temperatures is still not comprehensively studied in a wide temperature range. In this work, we have performed a systematical temperature-dependent (83 K—483 K) Raman spectroscopic analysis of the MoS2/MoSe2 van der Waals (vdW) heterostructures and discussed their stability. After the transfer process of the MoS2 monolayers onto the MoSe2/SiO2/Si, we annealed the samples, which is a commonly used process to increase the crystallinity. Associatively, the thermal annealing process leads to a decrease in the thermal coefficients of the E1
2g and A1g modes of MoS2 and MoSe2 monolayers. Our study shows that the peak positions of the Raman modes in the heterostructures redshift with an increase in temperature. Furthermore, the full width at half maximum (FWHM) of the E1
2g and A1g modes of the layers broaden at higher temperatures. This phenomenon is attributed to increasing phonon–phonon interactions and thermal expansion effects with the ascending temperature. To the best of our knowledge, for the first time, temperature-dependent Raman analysis of MoS2/MoSe2 vdW heterostructures before and after annealing are carried out; and peak positions, FWHMs, and thermal coefficients of the layers are extracted. We do not observe any deformation in the heterobilayer structure even at very low (83 K) or very high temperatures (483 K). This is the first step to confirm the durability of the MoS2/MoSe2 heterolayered devices under extreme temperatures by studying their thermal properties.
Gravitational wave imprint of new symmetry breaking *
Authors: Chao Wei , Cui Wen-Feng , Guo Huai-Ke , Shu Jing
Published: September 2020

It is believed that there are more fundamental gauge symmetries beyond those described by the Standard Model of particle physics. The scales of these new gauge symmetries are usually too high to be reachable by particle colliders. Considering that the phase transition (PT) relating to the spontaneous breaking of new gauge symmetries to the electroweak symmetry might be strongly first order, we propose considering the stochastic gravitational waves (GW) arising from this phase transition as an indirect way of detecting these new fundamental gauge symmetries. As an illustration, we explore the possibility of detecting the stochastic GW generated from the PT of

in the space-based interferometer detectors. Our study demonstrates that the GW energy spectrum is reachable by the LISA, Tianqin, Taiji, BBO, and DECIGO experiments only for the case where the spontaneous breaking of

is triggered by at least two electroweak singlet scalars.
Finite particle number description of neutron matter using the unitary correlation operator and high-momentum pair methods *
Authors: Wan Niu , Myo Takayuki , Xu Chang , Toki Hiroshi , Horiuchi Hisashi , Lyu Mengjiao
Published: September 2020

Using bare Argonne V4' (AV4'), V6' (AV6'), and V8' (AV8') nucleon–nucleon (NN) interactions, the nuclear equations of state (EOSs) for neutron matter are calculated with the unitary correlation operator and high-momentum pair methods. Neutron matter is described using a finite particle number approach with magic number

under a periodic boundary condition. The central short-range correlation originating from the short-range repulsion in the

interaction is treated by the unitary correlation operator method (UCOM), and the tensor correlation and spin-orbit effects are described by the two-particle two-hole (2p2h) excitations of nucleon pairs, where the two nucleons with a large relative momentum are regarded as a high-momentum (HM) pair. With increasing 2p2h configurations, the total energy per particle of the neutron matter is well-converged under this UCOM+HM framework. Comparing the results calculated with AV4', AV6', and AV8'

interactions, we demonstrate the effects of the short-range correlation, tensor correlation, and spin-orbit coupling on the density dependence of the total energy per particle of neutron matter. Moreover, the contribution of each Hamiltonian component to the total energy per particle is discussed. The EOSs of neutron matter calculated within the present UCOM+HM framework agree with the calculations of six microscopic many-body theories, especially the auxiliary field-diffusion Monte Carlo calculations.
Fast heating dissociation of

in heavy ion collisions at RHIC *
Authors: Liu Yunpeng , Chen Baoyi
Published: September 2020

By adopting the adiabatic assumption in the cooling process, we discuss a novel mechanism of

suppression that occurs due to the fast heating process at the early stage of the fireball, instead of its finite decay width in a finite temperature medium generated by heavy ion collisions. We calculate the transition probability after the fast heating dissociation as a function of the temperature of the medium and the nuclear modification factor in central collisions and find that the suppression is not negligible at RHIC, even if the width of

becomes zero.
Vanadium-based nanomaterials for cancer diagnosis and treatment
Authors: Hu Doudou , Li Dongdong , Liu Xiangrui , Zhou Zhuxian , Tang Jianbin , Shen Youqing
Published: September 2020

In the past few decades, various vanadium compounds have displayed potential in cancer treatment. However, fast clearness in the body and possible toxicity of vanadium compounds has hindered their further development. Vanadium-based nanomaterials not only overcome these limitations, but take advantage of the internal properties of vanadium in photics and magnetics, which enable them as a multimodal platform for cancer diagnosis and treatment. In this paper, we first introduced the basic biological and pharmacological functions of vanadium compounds in treating cancer. Then, the synthesis routes of three vanadium-based nanomaterials were discussed, including vanadium oxides, 2D vanadium sulfides, carbides and nitrides: VmXn (X = S, C, N) and water-insoluble vanadium salts. Finally, we highlighted the applications of these vanadium-based nanomaterials as tumor therapeutic and diagnostic agents.
High spatial resolution ozone risk-assessment for Asian forests
Authors: Marco Alessandra De , Anav Alessandro , Sicard Pierre , Feng Zhaozhong , Paoletti Elena
Published: September 2020

Background tropospheric ozone (O3) is increasing particularly over China and India, and becomes a major threat to Asian forests. By using the coupled WRF-Chem model at high spatial resolution (8 km) over Asia in 2015, we showed that both standards AOT40 (European) and W126 (United States) underestimated the O3 risk to deciduous forests and overestimated it to evergreen forests compared to the biologically based metric POD1. Both metrics AOT40 and W126 showed different spatial distribution and exceedance extent with respect to POD1. We found very high potential of O3 impacts on deciduous forest growth in Asia, while potential O3 impacts on evergreen forest types were lower. The most limiting factors were light availability, soil water content and air temperature (65%, 29% and 6%, respectively), making this region of the globe at high O3 risk for deciduous species and at medium O3 risk for evergreen species. For the first time, the O3 risk to Asian forests was quantified at high spatial resolution; and our results suggested: (i) a relevant overestimation of O3 risk to evergreen forests when using AOT40 and W126 relative to the more biologically based POD1 metric; and (ii) a significant underestimation of O3 risk to the boreal deciduous forests when using AOT40 and W126 relative to POD1 because of stomatal aperture permissive condition.
Estimation of hydrothermally synthesized Iron incorporated 2D-sheet-like α-MoO3 microstructural and optical parameters treated by annealing temperature
Authors: Sen Sapan Kumar , Manir M S , Nur Salahuddin , Hossain M N , Islam M Jahurul , Alam A K M M , Hakim M A
Published: September 2020

In this article, pure and Fe-doped (5 wt.%) α-MoO3 nanosheets have been synthesized by hydrothermal approach and doped nanosheets were further annealed (at Ta = 600 °C and Ta = 700 °C temperatures for 3 hrs) for improved crystalline properties. The XRD analysis revealed the formation of orthorhombic structure without tracing of impurities or secondary phases. The iron dopant and annealing temperatures improved the crystallinity as the crystallite size increased. The pristine sample consists with randomly oriented nanosheets with an average width of 100–200 nm and length of several micrometers. Doping with iron does not induce any noticeable effect on morphology of α-MoO3, as revealed by FESEM imaging. The doped nanosheets form a large, rectangular plate-type layered structure at 600 °C. Nanosheets with more developed and smooth surfaces with sharp corners and edges were observed at an elevated temperature of 700 °C. EDX study confirmed the Fe incorporation. The presence of different functional groups was analyzed by FTIR spectra. As a result of Fe doping, the band gap has decreased by 10% from an intrinsic value of ∼3.00 eV. The thermal annealing step further modifies the optical bandgap, providing an extracted value of 2.85 eV in this study.
Investigation on microstructure, mechanical properties and corrosion behavior of Sc-contained Al-7075 alloys after solution-aging treatment
Authors: Deng Jinzhao , Shen Jun , Li Hao , Chen Hui , Xie Fuxing
Published: September 2020

This work mainly studies on Sc microalloying in Al-7075 alloys. The microstructure characteristics and mechanical properties of the Sc-contained Al-7075 alloys were investigated after homogenization at 460 ℃ for 10 h. The corrosion behavior of the 7075 alloys after aging was examined using a three-electrode system. The results showed that significant reduction in grain sizes from 129.92 μm without Sc alloy to 32.17 μm with 0.6% Sc. The microhardness increased with the increase of Sc content in the alloy from 71.7 ± 1.3 HV without Sc alloy to 89.2 ± 4.7 HV. The tensile strength also increased from 151.82 ± 1.07 MPa to 212.85 ± 7.35 MPa. The results also revealed that the addition of Sc element in 7075 aluminum alloys not only reduced the corrosion current density of the alloy, but also increased the corrosion resistance of the alloy in the corrosive environment.
Physical properties and up- conversion development of Ho3+ions loaded in nano-composite silica titania thin film
Authors: Shaier Hanaa , Salah Abeer , M Mousa Wafaa , S Hamed Sawsan , Battisha Inas K
Published: September 2020

Structural and fluorescence properties were investigated for different concentrations of Ho3+ions doped silica titania nano-composite thin films. These films were deposited on glass substrates at two different annealing temperatures 300 and 500 °C for 3 h.The obtained films were transparent, smooth and adhesive to the substrate glass surface. The crystallite sizes were in the nano-scale phase with values ranged from 15 to 20 nm. The average thin film thickness was found to be equal to about 1.7μm. Blue, red and green up-conversion emissions are detected using 808 nm laser diode. The highest emission bands were observed in the doped film with 0.4 mol% of Ho3+ions. The prepared thin films could be considered promising candidates for higher efficiency up-down shifting solar cell, photonic, photo-catalytic and optical sensor applications.