bluuebunny/crossref_metadata_2025_split 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.
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.
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

AbstractHypertensive 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

AbstractThe 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

AbstractMost 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

AbstractPrevious 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

AbstractMicrobursts 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

AbstractNormal 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

AbstractRobustness 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

AbstractDNA 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

AbstractThe 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

AbstractThis 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.