bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Tomographic 3D Reconstruction Methods To A Diverse Range of Biological Preparations
Authors: McEwen B.F. , Frank J.
Published: June 2020

Tomography is a completely general three-dimensional (3D) reconstruction approach which can be applied to almost any biological structure which is sufficiently contrasted from its background. We have used tomography to compute 3D reconstructions of a diverse group of biological preparations which include: the cilium and the kinetochore, which were positively stained and imaged in 0.25 μm sections; the dendrite and the Golgi apparatus, which were selectively stained, before embedding, and imaged in 3 μm sections; chromatin fibers, which were negatively stained; and patch-clamped membranes which were critically point dried and imaged as whole mounts in their micropipettes.

With the cilium, we found good overall agreement with the known structure but were unable to completely resolve the fine structure for several reasons. Figure 1 illustrates how a different volume rendering technique, which included partial transparency, was able to bring out a dynein repeat that was not detected in our original study. With the kinetochore (figure 2), the structure is too complicated for the eye to readily comprehend and a procedure of selective data reduction is being developed. The dendrite and the Golgi apparatus (figure 3) are favorable objects for tomography because selective staining allows a large depth to be reconstructed (3 μm) and yet the structures are simple enough for surface renditions to provide a clear picture of the 3D ultrastructure. The dendrite reconstructions provided valuable surface area information and the Golgi reconstructions are expected to yield clues as to how this structure is formed. The chromatin fiber afforded the highest resolution reconstruction we obtained (figure 4) and, in conjunction with a 3D peak search, we were able to locate the positions of individual nucleosomes (figure 5). However, fiber flattening and other effects of the preparatory procedures were noted. The cylindrical geometry of the patch-clamped membranes in a micropipette is ideal for tomography because the sample thickness does not change with tilt angle and an unlimited tilt range should be possible. We are currently working on the latter but the availability of the full tilt range and the sides of the micropipette present some problems for the presently implemented alignment schemes.
Image Analysis-Based Microstructural Characterization of Eutectic Silicide Composites
Authors: Hefter J. , Harris J.L. , Ditchek B.M.
Published: June 2020

Image processing and analysis provides a variety of powerful tools for characterizing morphological features of material microstructure including determination of object size and shape. Feature analysis of the rod structures present in Si-TaSi2 semiconductor-metal eutectic composites has been important since any non-circularity or nonhomogeneous distribution of these rods can affect leakage currents in devices. In addition, device yield and reproducibility can be affected by nonuniformities in rod size, shape, and spacing in a given wafer.

Determination of rod density variations in Si-TaSi2 eutectic composites have been carried out using a scanning electron microscopy-image processing and analysis methodology. SEM data (Fig. 1) were collected using a JEOL 840 instrument (including computer-controlled x-y stage automation) coupled with a Tracor Northern 8502 high-performance image analyzer. Digital backscattered electron images were collected (512×512×8) since this imaging mode provided excellent contrast between the Ta-containing rods and the Si matrix. Gray-scale images were converted to binary images by suitable thresholding and then processed to determine the morphometries of interest. Programmed schedules allowed for computer acquisition of line profiles of data including control of specimen position. Typical line profiles across the widest portion of the wafer generally required 150-200 frames (at a magnification of 1000×) and occupied the instrument for ≈3 h.
Routine Digital Processing of Microscope Images
Authors: Wisse E. , Geerts A. , De Zanger R.B.
Published: June 2020

The slowscan and TV signal of the Philips SEM 505 and the signal of a TV camera attached to a Leitz fluorescent microscope, were digitized by the data acquisition processor of a Masscomp 5520S computer, which is based on a 16.7 MHz 68020 CPU with 10 Mb RAM memory, a graphics processor with two frame buffers for images with 8 bit / 256 grey values, a high definition (HD) monitor (910 × 1150), two hard disks (70 and 663 Mb) and a 60 Mb tape drive. The system is equipped with Imaging Technology video digitizing boards: analog I/O, an ALU, and two memory mapped frame buffers for TV images of the IP 512 series. The Masscomp computer has an ethernet connection to other computers, such as a Vax PDP 11/785, and a Sun 368i with a 327 Mb hard disk and a SCSI interface to an Exabyte 2.3 Gb helical scan tape drive. The operating system for these computers is based on different versions of Unix, such as RTU 4.1 (including NFS) on the acquisition computer, bsd 4.3 for the Vax, and Sun OS 4.0.1 for the Sun (with NFS).
Coincidence-Site-Lattice Pattern (Csl Pattern) of 70.5°/[110] Boundary of the 6H-Type Layer Structure
Authors: Kitano Yasuyuki , Takata Masaki
Published: June 2020

The most useful and intuitive model may be a CSL-model to analyze boundary structures. In order to apply the CSL-model to layer structures, we have proposed to use ‘lattice point’ in a wide sence and to add extra lattice points to the Bravais lattice points when interpenetrating(IP)-lattices are drawn. These lattice points will be called ‘extended lattice points‘. It is well known that a layer structure is built up with (almost) identical layers stacking on the top of the others with a cirtain amount of shift in a direction perpendicular to the stacking. Each layer consists of one or more atomic planes and has almost (or exactly) the same atomic configuration. The extended lattice points can be defined as the origins in each layer in crystal. The number of such points depends upon the number of layers in a unitcell.

To draw IP-lattices we have adopted all the extended lattice points in addition to the Bravais lattice points. There are three important advantages of doing this extension[ 1,2,3]. First is that the Coincidence-Sites in the IP-lattices drawn do not scatter homogeneously, but gather in a region and make a cluster. They exibit a characteristic pattern of Coincidence-Sites. This pattern is called a CSL-pattern. Second is that the DSC-lattice (Displacement Shift Complete Lattice) provides a set of basic vectors smaller than predicted before extention. Third is that reasonable models of boundaries are able to be made between two different layer structures. This is because the crystal volume attributed to one extended lattice point is exactly the same for the both adjacent crystals.
The Direct Observation of Lattice Images of Cadmium Arachidate in Ultrathin Films
Authors: Inoue Takahito , Okada Masakazu , Yase Kiyoshi
Published: June 2020

Organic ultrathin films which were prepared by Langmuir-Blodgett (LB) and physical vapour deposition (PVD) techniques, have aroused intense interest because of their possibilities of potential applications such as in electronic and optical materials, electron-beam resists and so on. For the realization of such applications, it would be very useful to know the microscopic structure of the organic ultrathin films and the formation mechanism of those. Electron microscopy is ideal to understand the relationship between the structure and the property of interests ; in fact, molecular images have been reported on phtha 1ocyanine derivatives1 and polymers. However, in the case of such as fatty acids and their derivatives, the lattice imaging has not yet been achieved because of severe radiation damage by incident electron beam.
TREND-CYCLE DECOMPOSITIONS OF REAL GDP REVISITED: CLASSICAL AND BAYESIAN PERSPECTIVES ON AN UNSOLVED PUZZLE
Authors: Kim Chang-Jin , Kim Jaeho
Published: June 2020

While Perron and Wada (2009) maximum likelihood estimation approach suggests that postwar US real GDP follows a trend stationary process (TSP), our Bayesian approach based on the same model and the same sample suggests that it follows a difference stationary process (DSP). We first show that the results based on the approach should be interpreted with caution, as they are relatively more subject to the ‘pile-up problem’ than those based on the Bayesian approach. We then directly estimate and compare the two competing TSP and DSP models of real GDP within the Bayesian framework. Our empirical results suggest that a DSP model is preferred to a TSP model both in terms of in-sample fits and out-of-sample forecasts.
Association between maternal hypertensive disorders of pregnancy and child neurodevelopment at 3 years of age: a retrospective cohort study
Authors: Noda Masahiro , Yoshida Satomi , Mishina Hiroki , Matsubayashi Keisuke , Kawakami Koji
Published: June 2020

Hypertensive disorders of pregnancy (HDP) affect up to 10% of women during pregnancy and influence child neurodevelopment, including mental and motor function. We assessed whether HDP, including gestational hypertension, preeclampsia, superimposed preeclampsia, and eclampsia, correlate with motor and mental developmental abnormalities in 3-year-old children, using data obtained between April 2004 and March 2013 through a mandatory population-based health checkup of mothers and children in Kobe city, Japan. The primary outcome was motor and mental developmental abnormalities at 3 years of age; parental-reported questionnaires and physician’s medical examinations were evaluated. The association between maternal HDP and child neurodevelopmental abnormality was evaluated using a logistic regression model. Of the 43,854 participating children, 1120 were born to women with HDP and 42,734 were born to women without HDP. The prevalence of motor developmental abnormality was 1.7% in the exposed group and 0.95% in the control group; the prevalence of mental developmental abnormality was 2.41% in the exposed group and 1.22% in the control group. Children born to mothers with HDP did not have an increased risk of motor developmental abnormality at the age of 3 years [adjusted odds ratio (OR) 1.17, 95% confidence interval 0.72–1.91], but had an increased risk of mental developmental abnormality (adjusted OR 1.80, 95% confidence interval 1.21–2.69). Maternal HDP were associated with mental development abnormality in 3-year-old children. These findings may be clinically relevant; mental abnormality in children born to women with HDP could be detected during early stages, which would facilitate early intervention.
Boron and Lithium in Calcium Sulfate Veins: Tracking Precipitation of Diagenetic Materials in Vera Rubin Ridge, Gale Crater
Authors: Das D. , Gasda P. J. , Wiens R. C. , Berlo K. , Leveille R. J. , Frydenvang J. , Mangold N. , Kronyak R. E. , Schwenzer S. P. , Forni O. , Cousin A. , Maurice S. , Gasnault O.
Published: June 2020

The NASA Curiosity rover's ChemCam instrument suite has detected boron in calcium‐sulfate‐filled fractures throughout the sedimentary strata of Gale crater including Vera Rubin ridge. The presence of elevated B concentration provides insights into Martian subsurface aqueous processes. In this study we extend the data set of B in Ca‐sulfate veins across Gale crater, comparing the detection frequency and relative abundances with Li. We report 33 new detections of B within veins analyzed between Sols 1548 and 2311 where detections increase in Pettegrove Point and Jura members, which form Vera Rubin ridge. The presence of B and Li in the Ca‐sulfate veins is possibly due to dissolution of preexisting B in clays of the bedrock by acids or neutral water and redistribution of the elements into the veins. Elevated frequency of B detection in veins of Gale crater correlates with presence of dehydration features such as desiccation cracks, altered clay minerals and detections of evaporites such as Mg‐sulfates and chloride salts in the host rocks. The increased observations of B also coincide with decreased Li concentration in the veins (average Li concentration of veins drops by ~15 ppm). Boron and Li have varying solubilities, and Li does not form salts as readily upon dehydration as B, causing it to remain in the solution. So the weak negative correlation between B and Li may reflect the crystallization sequence during dehydration on Vera Rubin ridge.
A More General Paradigm for Understanding the Decoupling of Stratocumulus‐Topped Boundary Layers: The Importance of Horizontal Temperature Advection
Authors: Zheng Youtong , Rosenfeld Daniel , Li Zhanqing
Published: June 2020

Most prior studies on decoupling of a stratocumulus‐topped boundary layer (STBL) are focused on subtropics where cold air advection with moderate strength is dominant. This study expands across a wider spectrum of temperature advection spanning from moderately strong warm air advection to extremely strong cold air advection. A STBL undergoing warm advection is found to be more mixed than a STBL undergoing cold advection. This finding is consistent with the cold advection facilitating turbulent mixing in the boundary layer. When cold advection becomes sufficiently strong (<−5 K/day), the STBL becomes more stably stratified again because of emergence of the cumulus‐coupled STBL regime induced by the “deepening‐warming” mechanism. Such a “deepening‐warming” induced STBL decoupling, however, is still much weaker than that caused by warm advection flows (even weak ones), suggesting that the direction and strength of temperature advection must be considered for any STBL decoupling studies.
Vertical Gradient Variations in Radiation Budget and Heat Fluxes in the Urban Boundary Layer: A Comparison Study Between Polluted and Clean Air Episodes in Beijing During Winter
Authors: Wang Linlin , Fan Sihui , Hu Fei , Miao Shiguang , Yang Aqiang , Li Yubin , Liu Junkai , Liu Changwei , Chen Shanshan , Ho Hung Chak , Duan Zexia , Gao Zhiqiu , Yang Yuanjian
Published: June 2020

Previous studies have reported air pollution‐radiation interactions in the urban boundary layer (UBL), but vertical gradient variations in the radiation budget and heat flux under air pollution conditions are relatively sparse. In this study, based on gradient observations from the Beijing 325 m meteorological tower in December 2015, the characteristics of near‐surface radiation balance and energy budget at three levels under different pollution conditions were comparatively investigated. Relative to clean days, both downward and upward shortwave radiation (DSR and USR) dropped during daytime, while downward and upward longwave radiation (DLR and ULR) enhanced during nighttime on heavily polluted days, showing that with evaluated height, the drop magnitudes of DSR and USR decreased, while the enhancement magnitude of DLR (ULR) decreased (increased). The combined effects of four radiation components significantly induced the reduction in net radiation (Rn) on polluted days, leading to the near‐surface energy budget change. In addition, the monthly averaged anthropogenic heat flux (Qf) was estimated to quantitatively calculate the heat storage (G) term in the surface energy budget. During daytime, compared to the clean episodes, the sensible heat flux (H) was reduced more than Rn in the whole near‐surface UBL during heavy polluted episodes, resulting in smaller H/(Rn + Qf) and larger G/(Rn + Qf). Finally, we revealed that weak thermal forcing effects caused by insufficient availability of net radiation energy at the surface and weak dynamic motion associated with weak winds were both responsible for the larger reduction (increase) in H (G) during pollution episodes in the whole near‐surface UBL.
Microburst Detection With the WRF Model: Effective Resolution and Forecasting Indices
Authors: Bolgiani Pedro , Santos‐Muñoz Daniel , Fernández‐González Sergio , Sastre Mariano , Valero Francisco , Martín María Luisa
Published: June 2020

Microbursts are meteorological phenomena in the lower troposphere which can produce damaging surface winds and pose a severe risk to aircraft flying close to the ground. As these events usually span less than 4 km and 15 min, the spatiotemporal resolution is a challenge for numerical simulations. Although research of microburst using operative mesoscale models is scarce, the Weather Research and Forecasting (WRF) model has been used in the diagnosis of this phenomenon. In this paper, such model is used to simulate several microburst conducive days using two different boundary conditions. The energy spectra of the simulations are computed to evaluate the effective resolution of the model. The results are in line with previous studies and produce no notable differences among the boundary conditions. Nonetheless, the energy spectra show an overenergetic troposphere at microscale resolutions, rendering the effective resolution inadequate for microburst forecasting using the simulated physics variables. Thus, mesoscale indices are analyzed as a prognostic tool. The wind index, the wet microburst severity index and the microburst windspeed potential index do not show high forecasting performances, even though improving the results of climatology. Also, notable differences among the boundary conditions can be seen. The most consistent results are achieved by the wet microburst severity index.
Tumor-induced neurogenesis and immune evasion as targets of innovative anti-cancer therapies
Authors: Cervantes-Villagrana Rodolfo Daniel , Albores-García Damaris , Cervantes-Villagrana Alberto Rafael , García-Acevez Sara Judit
Published: June 2020

Normal cells are hijacked by cancer cells forming together heterogeneous tumor masses immersed in aberrant communication circuits that facilitate tumor growth and dissemination. Besides the well characterized angiogenic effect of some tumor-derived factors; others, such as BDNF, recruit peripheral nerves and leukocytes. The neurogenic switch, activated by tumor-derived neurotrophins and extracellular vesicles, attracts adjacent peripheral fibers (autonomic/sensorial) and neural progenitor cells. Strikingly, tumor-associated nerve fibers can guide cancer cell dissemination. Moreover, IL-1β, CCL2, PGE2, among other chemotactic factors, attract natural immunosuppressive cells, including T regulatory (Tregs), myeloid-derived suppressor cells (MDSCs), and M2 macrophages, to the tumor microenvironment. These leukocytes further exacerbate the aberrant communication circuit releasing factors with neurogenic effect. Furthermore, cancer cells directly evade immune surveillance and the antitumoral actions of natural killer cells by activating immunosuppressive mechanisms elicited by heterophilic complexes, joining cancer and immune cells, formed by PD-L1/PD1 and CD80/CTLA-4 plasma membrane proteins. Altogether, nervous and immune cells, together with fibroblasts, endothelial, and bone-marrow-derived cells, promote tumor growth and enhance the metastatic properties of cancer cells. Inspired by the demonstrated, but restricted, power of anti-angiogenic and immune cell-based therapies, preclinical studies are focusing on strategies aimed to inhibit tumor-induced neurogenesis. Here we discuss the potential of anti-neurogenesis and, considering the interplay between nervous and immune systems, we also focus on anti-immunosuppression-based therapies. Small molecules, antibodies and immune cells are being considered as therapeutic agents, aimed to prevent cancer cell communication with neurons and leukocytes, targeting chemotactic and neurotransmitter signaling pathways linked to perineural invasion and metastasis.
Spin memory of the topological material under strong disorder
Authors: Korzhovska Inna , Deng Haiming , Zhao Lukas , Deshko Yury , Chen Zhiyi , Konczykowski Marcin , Zhao Shihua , Raoux Simone , Krusin-Elbaum Lia
Published: June 2020

Robustness to disorder is the defining property of any topological state. The ultimate disorder limits to topological protection are still unknown, although a number of theories predict that even in the amorphous state a quantized conductance might yet reemerge. Here we report that in strongly disordered thin films of the topological material Sb2Te3disorder-induced spin correlations dominate transport of charge—they engender a spin memory phenomenon, generated by the nonequilibrium charge currents controlled by localized spins. We directly detect a glassy yet robust disorder-induced magnetic signal in films free of extrinsic magnetic dopants, which becomes null in a lower-disorder crystalline state. This is where large isotropic negative magnetoresistance (MR)—a hallmark of spin memory—crosses over to positive MR, first with only one e2/h quantum conduction channel, in a weakly antilocalized diffusive transport regime with a 2D scaling characteristic of the topological state. A fresh perspective revealed by our findings is that spin memory effect sets a disorder threshold to the protected topological state. It also points to new possibilities of tuning spin-dependent charge transport by disorder engineering of topological materials.
Evolutionary advantage of anti-parallel strand orientation of duplex DNA
Authors: Subramanian Hemachander , Gatenby Robert A.
Published: June 2020

DNA in all living systems shares common properties that are remarkably well suited to its function, suggesting refinement by evolution. However, DNA also shares some counter-intuitive properties which confer no obvious benefit, such as strand directionality and anti-parallel strand orientation, which together result in the complicated lagging strand replication. The evolutionary dynamics that led to these properties of DNA remain unknown but their universality suggests that they confer as yet unknown selective advantage to DNA. In this article, we identify an evolutionary advantage of anti-parallel strand orientation of duplex DNA, within a given set of plausible premises. The advantage stems from the increased rate of replication, achieved by dividing the DNA into predictable, independently and simultaneously replicating segments, as opposed to sequentially replicating the entire DNA, thereby parallelizing the replication process. We show that anti-parallel strand orientation is essential for such a replicative organization of DNA, given our premises, the most important of which is the assumption of the presence of sequence-dependent asymmetric cooperativity in DNA.
Preparation and qualification of internal rabies reference standards for use in the rabies rapid fluorescent focus inhibition test
Authors: Timiryasova Tatyana M. , Hodge Shekema A. , Zheng Lingyi , Singer Amy , Vincent Deanne , Rahman Mohammad , Petit Celine , Brown Monique
Published: June 2020

The World Health Organization (WHO) international standard rabies immune globulins (SRIGs) allow the standardisation of the cell-based rapid fluorescent-focus inhibition test (RFFIT) for rabies virus neutralising antibody measurement. SRIG stocks have been depleted. We describe the preparation and qualification of two internal rabies reference standards (IRRSs), calibrated against WHO SRIGs. Candidate IRRSs IMORAB2, from human rabies immunoglobulin; and GCIRAB1, from pooled serum samples from healthy adults immunised with licensed rabies vaccine, were generated. IRRSs were qualified for use in RFFIT based on pre-determined acceptance criteria. Unitage (IU/mL) was assigned using WHO-1 and WHO-2 SRIGs as calibrators. Geometric mean concentrations (GMCs) (% geometric coefficient of variation), calibrated against WHO-1 and WHO-2 SRIGs, were: 1.8 IU/mL (18.7%) and 1.5 IU/mL (17.8%) for IMORAB2; and 2.9 IU/mL (17.5%) and 2.5 IU/mL (16.7%), respectively, for GCIRAB1. We demonstrated IRRS specificity in competition studies using homologous (inactivated Pitman Moore rabies virus) and heterologous (inactivated vesicular stomatitis virus) antigens and acceptable accuracy/linearity of WHO SRIGs using IRRSs as calibrators. Concordance between IRRS and the WHO-1 SRIG was demonstrated using (non-)clinical human serum samples. The candidate reference standards are suitable for use as IRRS in the in-house rabies RFFIT. Funding:Sanofi Pasteur.
Novel Grafted/Crosslinked Cellulose Acetate Membrane with N-isopropylacrylamide/N,N-methylenebisacrylamide for Water Desalination
Authors: Elkony Yasmeen , Mansour El-Sayed , Elhusseiny Amel , Hassan Hammed , Ebrahim Shaker
Published: June 2020

This work aims to prepare new types of grafted and crosslinked cellulose acetate (CA) reverse osmosis (RO) membranes by phase inversion technique. The grafting and/or crosslinking processes of the pristine CA-RO membrane were conducted using N-isopropylacrylamide (N-IPAAm) and N,N-methylene bisacrylamide (MBAAm), respectively. The grafting/crosslinking mechanism onto the CA-RO membrane surface was proposed. Atomic force microscope (AFM) images of the pure CA-RO and 0.1 wt% N-IPAAm-grafted CA-RO membranes revealed that the surface roughness was 42.99 nm and 11.6 nm, respectively. Scanning electron microscopy (SEM) images of the 0.1 wt% grafted/crosslinked membrane indicated the finger-like macrovoids structure. It was observed that the contact angle of the pristine CA-RO membrane was 66.28° and declined to 49.7° for 0.1 wt % N-IPAAm-grafted CA-RO membrane. The salt rejection of the pristine CA-RO membrane was 93.7% and increased to 98.9% for the grafted 0.1 wt % N-IPAAm/CA-RO membrane. The optimum grafted/crosslinked composition was 0.1 wt %/ 0.013 wt % which produced the salt rejection and water flux of 94% and 3.2 L/m2h at low pressure, respectively. It was concluded that both the grafting and crosslinking processes enhanced the performance of the CA-RO membranes.
Genetically encoded biosensors for the detection of rapamycin: toward the screening of agonists and antagonists
Authors: Lee Euiyeon , Jeon Hyunjin , Ryu Jeahee , Kang Chungwon , Kim Soyoun , Park Seungil , Kwon Youngeun
Published: June 2020

A cell-based sensor to screen Rapamycin and its analogues is developed by using intein-mediated protein engineering. The target was reported by fluorescence translocation via signal-peptide reconstitution.
Diprotonative stabilization of ring-opened carbocationic intermediates: conversion of tetrahydroisoquinoline to triarylmethanes
Authors: Kurouchi Hiroaki
Published: June 2020

Superacid-promoted conversion of tetrahydroisoquinolines to triarylmethanesviatandem reactions of C–N bond scission, Friedel–Crafts alkylation, C–O bond scission, and electrophilic aromatic amidation was developed.
Remarkable self-sorting selectivity in covalently linked homochiral and heterochiral pairs driven by Pd2L4 helicate formation
Authors: Ogata Daiji , Yuasa Junpei
Published: June 2020

Remarkable self-sorting selectivity is demonstrated between LRR and LRS through a Pd2L4 assembly. By contrast, mixing of LRR and LSS with Pd2+ produces a near statistical mixture.
The influence of Ca–Mg disorder on the growth of dolomite: a computational study
Authors: Bruno M. , Ghignone S. , Pastero L. , Aquilano D.
Published: June 2020

A new growth model for primary dolomite is proposed, in which a disordered dolomite/calcite interface seems to promote dolomite nucleation on a newly formed calcite crystal.
Microscopic origin of the extremely low thermal conductivity and outstanding thermoelectric performance of BiSbX3 (X = S, Se) revealed by first-principles study
Authors: Zhang Ziye , Zhang Renqi , Qi Ning , Wu Yichu , Chen Zhiquan
Published: June 2020

An investigation of the origin of the extremely low thermal conductivity and outstanding thermoelectric performance of BiSbX3 (X = S, Se).
Energetics of CO2 and H2O adsorption on alkaline earth metal doped TiO2
Authors: da Silva Andre Luiz , Wu Lili , Caliman Lorena Batista , Castro Ricardo H. R. , Navrotsky Alexandra , Gouvêa Douglas
Published: June 2020

CO2 and H2O adsorption on TiO2 nanocatalyst has improved due to the surface segregation of alkaline earth metals.
Understanding surface charge regulation in silica nanopores
Authors: Yang Jie , Su Haiping , Lian Cheng , Shang Yazhuo , Liu Honglai , Wu Jianzhong
Published: June 2020

The combination of CDFT and surface reaction model captures the charge regulation of porous silica under nanoconfinement.
Modeling performance of rhamnolipid-coated engineered magnetite nanoparticles for U(vi) sorption and separation
Authors: Sharma Neha , Ghosh Anushree , Fortner John D. , Giammar Daniel E.
Published: June 2020

Iron oxide nanoparticles were stabilized in water using the biosurfactant rhamnolipid, and the adsorption of U(vi) to these nanoparticles was measured and modeled as a function of water chemistry.
Silicon isotope measurement in zircon by laser ablation multiple collector inductively coupled plasma mass spectrometry
Authors: Guitreau Martin , Gannoun Abdelmouhcine , Deng Zhengbin , Marin-Carbonne Johanna , Chaussidon Marc , Moynier Frédéric
Published: June 2020

This study reports the first Si isotope data measured in zircon using nanosecond laser ablation multiple collector inductively coupled plasma mass spectrometry.
Anin vitrotumor swamp model of heterogeneous cellular and chemotherapeutic landscapes
Authors: Lin Ke-Chih , Sun Yusha , Torga Gonzalo , Sherpa Pema , Zhao Yihua , Qu Junle , Amend Sarah R. , Pienta Kenneth J. , Sturm James C. , Austin Robert H.
Published: June 2020

A microfluidic platform was developed that generates a gradient of chemotherapyviadiffusion to study evolutionary dynamics of cancer.
Echogenic exosomes as ultrasound contrast agents
Authors: Osborn Jenna , Pullan Jessica E. , Froberg James , Shreffler Jacob , Gange Kara N. , Molden Todd , Choi Yongki , Brooks Amanda , Mallik Sanku , Sarkar Kausik
Published: June 2020

Exosomes, naturally secreted extracellular bilayer vesicles (diameter 40–130 nm), have been rendered echogenic (responsive to ultrasound) allowing their potential use as a dual agent for drug delivery and ultrasound imaging.
Gold incorporated hematite nanocatalyst for solvent-free CO2 fixation under atmospheric pressure
Authors: Tudu Gouri , Ghosh Sourav , Biswas Tanmoy , Mahalingam Venkataramanan
Published: June 2020

Au/α-Fe2O3 as a nanocatalyst for the conversion of epoxides to cyclic carbonates utilizing CO2 under 1 atm. pressure.
Correction: Near-infrared control and real-time detection of osteogenic differentiation in mesenchymal stem cells by multifunctional upconversion nanoparticles
Authors: Wang Kaipeng , Wu Qian , Wang Xichao , Liang Guohai , Yang Anli , Li Jinming
Published: June 2020

Correction for ‘Near-infrared control and real-time detection of osteogenic differentiation in mesenchymal stem cells by multifunctional upconversion nanoparticles’ by Kaipeng Wang et al., Nanoscale, 2020, 12, 10106–10116, DOI: 10.1039/D0NR00872A.
Fluorescent recognition of l- and d-tryptophan in water by micelle probes
Authors: Du Gengyu , Mao Yifan , Abed Mehdi A. , Pu Lin
Published: June 2020

A series of BINOL-based monoaldehydes in the presence of a diblock copolymer PEG-PLLA are encapsulated into micelles in water which in combination with Zn2+ have exhibited chemo- and enantioselective fluorescence enhancement with tryptophan.
Two dimensional semiconducting polymers
Authors: Wei Xin , Wang Mingfeng
Published: June 2020

Synthetic chemistry towards two-dimensional semiconducting polymers (2DSPs) with planar π-conjugated structures is reviewed and their unique chemical and physical properties derived from the extended π-conjugation are discussed.
Silver(i)-catalyzed selective hydroalkoxylation of C2-alkynyl quinazolinones to synthesize quinazolinone-fused eight-membered N,O-heterocycles
Authors: Kong Xiang-Fei , Guo Xiu-Yun , Gu Zi-Yu , Wei Lin-Su , Liu Lu-Lu , Mo Dong-Liang , Pan Cheng-Xue , Su Gui-Fa
Published: June 2020

A silver-catalyzed selective 8-endo-digcyclization of C2-alkynyl quinazolinones was developed to prepare a series of novel quinazolinone-fused eight-membered N,O-heterocycles in good-to-excellent yields under mild reaction conditions.
Photocatalytic toluene degradation: braiding physico-chemical and intrinsic kinetic analyses
Authors: Caudillo-Flores Uriel , Fernández-García Marcos , Kubacka Anna
Published: June 2020

Combined physico-chemical and kinetic analyses of photo-catalytic elimination reactions for quantitative understanding.
Stabilized albumin coatings on engineered xenografts for attenuation of acute immune and inflammatory responses
Authors: Tao Chao , Zhu Wenzhen , Iqbal Jabed , Xu Chenjie , Wang Dong-An
Published: June 2020

A novel and facile approach for attenuation of immune and inflammatory responses elicited by xenografts was introduced by coating albumin, after which xenografts showed enhanced immunocompatibility at cell, protein and gene levels.
Interface properties and dopability of an organic semiconductor: TAPP-Br variable as molecule but inert in the condensed phase
Authors: Tzschoppe Michael , Huck Christian , Butkevich Andrey , Günther Benjamin , Ulrich Constantin , Rose Jan Niklas , Gade Lutz H. , Pucci Annemarie
Published: June 2020

The behaviour of an organic semiconductor (TAPP-Br) is found to be variable upon condensation on various surfaces and as mixtures with typical dopants.
Enhanced stability and performance of light-emitting diodes based on in situ fabricated FAPbBr3 nanocrystals via ligand compensation with n-octylphosphonic acid
Authors: Wu Yanan , Liu Lihui , Wang Wei , Zhang Wenzhu , Yu Hongtao , Qian Jie , Chen Yanfeng , Shen Wei , Sui Shiqi , Deng Zhengtao , Chen Shufen , Huang Wei
Published: June 2020

Dual ligands are introduced for the in situ fabrication of perovskite nanocrystals, leading to higher crystallinity, improved stability and device efficiency.
p110δ PI3K as a therapeutic target of solid tumours
Authors: Xenou Lydia , Papakonstanti Evangelia A.
Published: June 2020

From the time of first characterization of PI3K as a heterodimer made up of a p110 catalytic subunit and a regulatory subunit, a wealth of evidence have placed the class IA PI3Ks at the forefront of drug development for the treatment of various diseases including cancer. The p110α isoform was quickly brought at the centre of attention in the field of cancer research by the discovery of cancer-specific gain-of-function mutations in PIK3CA gene in a range of human solid tumours. In contrast, p110δ PI3K was placed into the spotlight of immunity, inflammation and haematologic malignancies because of the preferential expression of this isoform in leucocytes and the rare mutations in PIK3CD gene. The last decade, however, several studies have provided evidence showing that the correlation between the PIK3CA mutations and the response to PI3K inhibition is less clear than originally considered, whereas concurrently an unexpected role of p110δ PI3K in solid tumours has being emerging. While PIK3CD is mostly non-mutated in cancer, the expression levels of p110δ protein seem to act as an intrinsic cancer-causing driver in various solid tumours including breast, prostate, colorectal and liver cancer, Merkel-Cell carcinoma, glioblastoma and neurobalstoma. Furthermore, p110δ selective inhibitors are being studied as potential single agent treatments or as combination partners in attempt to improve cancer immunotherapy, with both strategies to shown great promise for the treatment of several solid tumours. In this review, we discuss the evidence implicating the p110δ PI3K in human solid tumours, their impact on the current state of the field and the potential of using p110δ-selective inhibitors as monotherapy or combined therapy in different cancer contexts.
Metformin alleviates hyperuricaemia-induced serum FFA elevation and insulin resistance by inhibiting adipocyte hypertrophy and reversing suppressed white adipose tissue beiging
Authors: Su Mengqi , Sun Li , Li Wenpeng , Liu He , Liu Yang , Wei Ying , Yuan Yue , Zheng Linqun , Yin Shuangli , Dai Chenguang , Zhao Chenyang , Pan Zhenwei , Li Yue
Published: June 2020

Hyperuricaemia (HUA) significantly increases the risk of metabolic syndrome and is strongly associated with the increased prevalence of high serum free fatty acids (FFAs) and insulin resistance. However, the underlying mechanisms are not well established, especially the effect of uric acid (UA) on adipose tissue, a vital organ in regulating whole-body energy and FFA homeostasis. In the present study, we noticed that adipocytes from the white adipose tissue of patients with HUA were hypertrophied and had decreased UCP1 expression. To test the effects of UA on adipose tissue, we built both in vitro and in vivo HUA models and elucidated that a high level of UA could induce hypertrophy of adipocytes, inhibit their hyperplasia and reduce their beige-like characteristics. According to mRNA-sequencing analysis, UA significantly decreased the expression of leptin in adipocytes, which was closely related to fatty acid metabolism and the AMPK signalling pathway, as indicated by KEGG pathway analysis. Moreover, lowering UA using benzbromarone (a uricosuric agent) or metformin-induced activation of AMPK expression significantly attenuated UA-induced FFA metabolism impairment and adipose beiging suppression, which subsequently alleviated serum FFA elevation and insulin resistance in HUA mice. Taken together, these observations confirm that UA is involved in the aetiology of metabolic abnormalities in adipose tissue by regulating leptin-AMPK pathway, and metformin could lessen HUA-induced serum FFA elevation and insulin resistance by improving adipose tissue function via AMPK activation. Therefore, metformin could represent a novel treatment strategy for HUA-related metabolic disorders.
Measuring Global Coherence in People With Aphasia During Unstructured Conversation
Authors: Leaman Marion C. , Edmonds Lisa A.
Published: June 2020

Purpose

Global coherence is an essential macrolinguistic discourse skill that speakers use to formulate discourse to convey meaning with maintenance to a topic. When global coherence is poor, the listener's ability to understand how the discourse makes sense as a whole is diminished. Measures exist to evaluate global coherence in people with aphasia during monologue tasks (e.g., picture description). The aim of the current research is to develop such a measure for unstructured conversation and to explore how global coherence is impacted by aphasia during conversation. A global coherence measure for conversation is required because markedly different cognitive and linguistic demands are made for production of different types of discourse. Thus, a structured monologue measure cannot be used with validity for unstructured conversation. To adequately evaluate global coherence during conversation, a measure specific to the demands of conversation is required.

Method

We adapted the 4-point Global Coherence Scale (Wright & Capilouto, 2012; Wright et al., 2013), a monologue-level measure of global coherence to conversation, resulting in the 4-point Global Coherence Scale in unstructured conversation (GCSconv). We conducted statistical evaluation of the reliability/stability of the 4-point GCSconv in 18 unstructured conversations held by nine people with aphasia. Utterances with low global coherence scores were classified following a recent methodology to describe how breakdown in these utterances contributed to diminished global coherence (Hazamy & Obermeyer, 2019).

Results

The 4-point GCSconv demonstrated excellent inter/intrarater reliability and test–retest stability. Nonspecific language and off-topic comments contributed most frequently to lowered global coherence.

Conclusions

Findings suggest the 4-point GCSconv may be a feasible and reliable measure of global coherence in conversation. This measure adds to a core of emerging reliable discourse measures for conversation. As such, it has potential to inform assessment and treatment of everyday conversation and to investigate the relationship of global coherence in structured monologue and unstructured conversation.

Supplemental Material

https://doi.org/10.23641/asha.12469187
Field enhancement assisted graphene‐based microring modulator for high modulation depth
Authors: Joshi Swati , Kaushik Brajesh Kumar
Published: June 2020

This study aims at optimising the graphene coverage in a microresonator for the design of an efficient modulator by using a combination of graphene induced losses and phase shift. The graphene integration in the ring can provide tunability by means of altering the loss and coupling coefficient by changing the graphene coverage or its chemical potential. The fundamental parameters of graphene integrated all‐pass ring resonator are extracted based on the transmission characteristics using finite‐difference time‐domain method. As compared to conventional graphene‐oxide‐semiconductor straight waveguide, graphene integrated on an all‐pass ring resonator shows enhanced optical absorption and phase shift due to field enhancement factor. A modulator based on graphene tunable loss and phase shift is investigated taking into account the field enhancement factor. For 1.55 μm radiation and ring radius of 3.75 μm with 22% graphene coverage, a maximum modulation depth of 12.6 dB is demonstrated based on electrostatic control of graphene chemical potential. The proposed modulator can feature operational speed in the range of 10 GHz that is useful in a variety of electro‐optic applications.
Uniform carrier‐based PWM method for three‐phase three‐level three‐wire and four‐wire converter system with neutral‐point balancing
Authors: Zhang Zhi , Zhu Zuhong , Hu Bihua , Tang Xiao , Liu Chang , Wang Zhiping
Published: June 2020

In this study, a simple carrier‐based pulse‐width modulation (CBPWM) method is proposed for a three‐phase three‐level neutral‐point‐clamped converter with neutral‐point (NP) balancing, which can be applied to three‐phase three‐wire (TPTW) and three‐phase four‐wire (TPFW) converter systems simultaneously. First, the effect of each switching state for the NP potential in TPTW and TPFW systems is analysed in detail, and a newly NP control strategy by reconstructing the switching state and adjusting the corresponding duration time is deduced for all operation conditions, it only needs to add the offset voltage to the modulation reference voltage to guarantee the NP balance and is easy to implement. Then, under all operating conditions, the mathematical model of NP current is derived and analysed to evaluate the low‐frequency voltage oscillation in the NP. Finally, the effectiveness and feasibility of the proposed CBPWM strategy are verified by the experimental results based on a 12 kVA laboratory prototype.
New modular high‐voltage pulse generator based on SEPIC converter for electroporation applications
Authors: Banaei Mohamad Reza , Khiz Ali Kholgh
Published: June 2020

High‐voltage (HV) pulses are widely used in many applications. This study proposes a new HV unipolar pulse generator based on Single‐Ended Primary‐Inductance Converter (SEPIC) for electroporation applications. The converter in the proposed pulse generator operates in discontinuous conduction mode with continuous input current. The proposed structure uses voltage‐boosting modules that are fed from a relatively low voltage DC source with a reduced number of semiconductors. The number of semiconductor devices and the voltage stress across them are important issues for HV pulse generators. The proposed approach does not have any chopping switches at the output stage, which greatly affects cost, efficiency, and system control. The employed semiconductor switches and diodes in the proposed topology have low voltage and current stresses, so the structure can be implemented with the market‐available semiconductor technology. Mathematical analysis is presented along with a full design of the system components. Finally, simulation and experimental results are presented to validate the proposed concept.
Influence of grain growth on the thermal structure of protoplanetary discs
Authors: Savvidou Sofia , Bitsch Bertram , Lambrechts Michiel
Published: June 2020

The thermal structure of a protoplanetary disc is regulated by the opacity that dust grains provide. However, previous works have often considered simplified prescriptions for the dust opacity in hydrodynamical disc simulations, for example, by considering only a single particle size. In the present work, we perform 2D hydrodynamical simulations of protoplanetary discs where the opacity is self-consistently calculated for the dust population, taking into account the particle size, composition, and abundance. We first compared simulations utilizing single grain sizes to two different multi-grain size distributions at different levels of turbulence strengths, parameterized through the α-viscosity, and different gas surface densities. Assuming a single dust size leads to inaccurate calculations of the thermal structure of discs, because the grain size dominating the opacity increases with orbital radius. Overall the two grain size distributions, one limited by fragmentation only and the other determined from a more complete fragmentation-coagulation equilibrium, give comparable results for the thermal structure. We find that both grain size distributions give less steep opacity gradients that result in less steep aspect ratio gradients, in comparison to discs with only micrometer-sized dust. Moreover, in the discs with a grain size distribution, the innermost (<5 AU) outward migration region is removed and planets embedded in such discs experience lower migration rates. We also investigated the dependency of the water iceline position on the alpha-viscosity (α), the initial gas surface density (Σg,0) at 1 AU and the dust-to-gas ratio (fDG) and find rice ∝ α0.61Σg,00.8fDG0.37 independently of the distribution used in the disc. The inclusion of the feedback loop between grain growth, opacities, and disc thermodynamics allows for more self-consistent simulations of accretion discs and planet formation.