julilili42/papers huggingface dataset:
Monitoring Self-Assembly and Ligand Exchange of PbS Nanocrystal Superlattices at the Liquid/Air Interface in Real Time
2018-01-24

We investigate in situ the structural changes during self-assembly of PbS nanocrystals from colloidal solution into superlattices, solvent evaporation, and ligand exchange at the acetonitrile/air interface by grazing incidence small-angle X-ray scattering (GISAXS). We simulate and fit the diffraction peaks under the distorted wave Born approximation (DWBA) to determine the lattice parameters. We observe a continuous isotropic contraction of the superlattice in two different assembly steps, preserving the body-centered cubic lattice with an overall decrease in the lattice constants of 11%. We argue that the first contraction period is due to a combination of solvent evaporation/annealing and capillary forces acting on the superlattice, whereas the second period is dominated by the effect of replacing oleic acid on the nanocrystal surface with the short and rigid cross-linker tetrathiafulvalene dicarboxylate. This work provides guidelines for optimized ligand exchange conditions and highlights the structural particularities arising from assembling NCs on liquid surfaces.
A parsec-scale optical jet from a massive young star in the Large Magellanic Cloud
2018-01-24

Highly collimated parsec-scale jets, which are generally linked to the presence of an accretion disk, are commonly observed in low-mass young stellar objects. In the past two decades, a few of these jets have been directly (or indirectly) observed from higher-mass (larger than eight solar masses) young stellar objects, adding to the growing evidence that disk-mediated accretion also occurs in high-mass stars, the formation mechanism of which is still poorly understood. Of the observed jets from massive young stars, none is in the optical regime (massive young stars are typically highly obscured by their natal material), and none is found outside of the Milky Way. Here we report observations of HH 1177, an optical ionized jet that originates from a massive young stellar object located in the Large Magellanic Cloud. The jet is highly collimated over its entire measured length of at least ten parsecs and has a bipolar geometry. The presence of a jet indicates ongoing, disk-mediated accretion and, together with the high degree of collimation, implies that this system is probably formed through a scaled-up version of the formation mechanism of low-mass stars. We conclude that the physics that govern jet launching and collimation is independent of stellar mass.
The Rise of the Anthroposphere since 50,000 Years: An Ecological Replacement of Megaherbivores by Humans in Terrestrial Ecosystems?
2018-01-24

Megaherbivores fulfilled a number of important ecological functions in terrestrial ecosystems and behaved as ecological engineers since 300 million years until around 12,000 years ago. These essential ecological functions include opening vegetation cover, selective seed dispersal and nutrient recycling and spreading. Thanks to these effects, megaherbivores change the vegetation structure where they live, with cascading effects on smaller herbivores and also on climate. The late Pleistocene extinction strongly impacted the megaherbivores almost all over the world and led to the loss of these important ecological functions in terrestrial ecosystems. These functions were partially restored by agriculturist humans through an ecological replacement that occurred through an ecological shift within the species Homo sapiens. A better understanding of the differences and similarities between the ecological impacts of megaherbivores and those of agricultural humans should help to predict the future of terrestrial ecosystems.
The Oral Bioavailability of 8‐Prenylnaringenin from Hops (Humulus Lupulus L.) in Healthy Women and Men is Significantly Higher than that of its Positional Isomer 6‐Prenylnaringenin in a Randomized Crossover Trial
2018-01-24

Scope Prenylated chalcones and flavonoids from hop ( Humulus lupulus L.), such as 6‐prenylnaringenin (6‐PN) and 8‐prenylnaringenin (8‐PN), are investigated for their health beneficial and anticancer activities. We, thus, compare the oral bioavailability and safety of 6‐PN and 8‐PN in healthy young women and men, and investigated their effects on peripheral blood mononuclear cells (PBMC). Methods and results A double‐blind, placebo‐controlled, crossover trial is conducted with 16 healthy volunteers (eight women, eight men) given a single oral dose of 500 mg 6‐PN, 8‐PN, or placebo in random order. Maximum total concentrations of 6‐PN and 8‐PN in plasma ( C max ; 543 and 2834 nmol L –1 ) and their respective area under the plasma concentration‐time curve (AUC; 3635 and 15801 nmol L –1 × h) are significantly (5.2‐ and 4.3‐fold) higher for 8‐PN than for 6‐PN ( p ˂ 0.05). PBMC for ex vivo experiments are isolated from blood sampled before and 6 h after intake of 6‐PN, 8‐PN, or placebo. Despite the single‐treatment regime and low blood concentrations, both 6‐PN and 8‐PN increase the survival of PBMC relative to control. Conclusion 8‐PN is significantly more bioavailable in healthy humans than its isomer 6‐PN. Interestingly, 6‐PN, despite being less bioavailable, is similarly effective as 8‐PN in enhancing PBMC viability.
Leptin Replacement Reestablishes Brain Insulin Action in the Hypothalamus in Congenital Leptin Deficiency
2018-01-24

OBJECTIVE Human obesity is associated with impaired central insulin signaling, and in very rare cases, severe obesity can be caused by congenital leptin deficiency. In such patients, leptin replacement results in substantial weight loss and improvement in peripheral metabolism. RESEARCH DESIGN AND METHODS In a leptin-deficient patient, we investigated the impact of leptin substitution on central insulin action, as quantified by changes in neuronal activity after intranasal insulin application. This was assessed before and during the first year of metreleptin substitution. RESULTS After only 1 year, treatment with metreleptin reestablishes brain insulin sensitivity, particularly in the hypothalamus and, to a lesser degree, in the prefrontal cortex. Results are depicted in comparison with a control group. In our patient, brain activation changes were accompanied by substantial weight loss, reduced visceral adipose tissue, reduced intrahepatic lipid content, and improved whole-body insulin sensitivity. CONCLUSIONS Leptin replacement and weight loss improved homeostatic insulin action in the patient in question.
Sequencing analysis of the SCA6 CAG expansion excludes an influence of repeat interruptions on disease onset
2018-01-24

Polyglutamine (polyQ) diseases are caused by coding expanded (CAG)n repeats in the respective genes.1 Repeat instability, both germ line and somatic, is known to occur in most polyQ diseases and can influence the phenotype. Longer repeats are usually associated with earlier ages at onset (AAO) and/or more severe disease courses. Repeat instability with expansion bias can have severe clinical consequences to patients with these devastating conditions for which there are no disease-modifying treatments available. Several factors, including the size of the repeats (longer repeats are more unstable), and the presence of sequence interruptions (pure repeats are more unstable) are known to have an influence.2 Spinocerebellar ataxia type 6 (SCA6), a late-onset autosomal dominant relatively slowly progressive and pure cerebellar ataxia,3 is one of the six polyQ SCAs. SCA6 is caused by expanded (CAG)n repeats in CACNA1A . Normal alleles range from 4 to 18 CAG repeats, while expanded repeats range from 20 to 33. Interestingly, SCA6 expanded alleles lie within the normal range of repeat sizes for all other polyQ diseases, below their respective pathogenic thresholds (usually 35–40 repeats or over).1 The CACNA1A repeats seem to be more stable than other CAG repeats.3 The presence of repeat interruptions can enhance overall repeat stability and has been observed in several polyQ diseases (eg, SCA1 and SCA2).4 Variants in DNA repair genes significantly modify AAO in polyQ diseases (eg, RRM2B SNPs ...
Social support and classroom management are related to secondary students’ general school adjustment: A multilevel structural equation model using student and teacher ratings.
2018-01-25

Teachers’ social support and classroom management are related to secondary students’ achievement, domain-specific interest, and self-concept. However, little is known about whether social support and classroom management shape secondary students’ general school adjustment beyond these domain-specific outcomes. To investigate this question, we drew on data from a large longitudinal research project (N = 5,607 secondary students, N = 227 classes). We applied student and teacher ratings of social support and classroom management to investigate their perspective-specific validities for predicting student outcomes. To measure students’ school adjustment, we assessed achievement as a domain-specific indicator and school satisfaction, truancy, and self-esteem as more general aspects. Multilevel confirmatory factor analyses showed that both teachers and students distinguished between social support and classroom management. Teacher and student ratings of classroom management largely converged, whereas their perceptions of social support were not statistically significantly associated with one another. In multilevel structural equation modeling, both perspectives uniquely predicted students’ school adjustment: Student-rated social support was linked to all outcomes at the student level and to school satisfaction and self-esteem at the class level. Classroom management showed only weak associations with outcomes at the student level, but at the class level, student-rated classroom management was related to truancy and teacher-rated classroom management was linked to school satisfaction and student achievement. These findings highlight the important role of teachers in students’ general school adjustment and show the benefit of considering different perspectives and levels of analyses. (PsycINFO Database Record (c) 2018 APA, all rights reserved)
Self-Assembly Template Driven 3D Inverse Opal Microspheres Functionalized with Catalyst Nanoparticles Enabling a Highly Efficient Chemical Sensing Platform
2018-01-25

The design of semiconductor metal oxides (SMOs) with well-ordered porous structure has attracted tremendous attention owing to their larger specific surface area. Herein, three-dimensional inverse opal In<sub>2</sub>O<sub>3</sub> microspheres (3D-IO In<sub>2</sub>O<sub>3</sub> MSs) were fabricated through one-step ultrasonic spray pyrolysis (USP) which employed self-assembly sulfonated polystyrene (S-PS) spheres as a sacrificial template. The spherical pores observed in the 3D-IO In<sub>2</sub>O<sub>3</sub> MSs had diameters of about 4 and 80 nm. Subsequently, the catalytic palladium oxide nanoparticles (PdO NPs) were loaded on 3D-IO In<sub>2</sub>O<sub>3</sub> MSs via a simple impregnation method, and their gas sensing properties were investigated. In a comparison with pristine 3D-IO In<sub>2</sub>O<sub>3</sub> MSs, the 3D-IO PdO@In<sub>2</sub>O<sub>3</sub> MSs exhibited a 3.9 times higher response (R<sub>air</sub>/R<sub>gas</sub> = 50.9) to 100 ppm acetone at 250 °C and a good acetone selectivity. The detection limit for acetone could extend down to ppb level. Furthermore, the 3D-IO PdO@In<sub>2</sub>O<sub>3</sub> MSs-based sensor also possess good long-term stability. The extraordinary sensing performance can be attributed to the novel 3D periodic porous structure, highly three-dimensional interconnection, larger specific surface area, size-tunable (meso- and macroscale) bimodal pores, and PdO NP catalysts.
A Prospective Study of Quantitative SPECT/CT for Evaluation of Lung Shunt Fraction Before SIRT of Liver Tumors
2018-01-25

The lung shunt fraction (LSF) is estimated using <sup>99m</sup>Tc-macroaggregated albumin (<sup>99m</sup>Tc-MAA) imaging before selective internal radiotherapy (SIRT) of the liver to reduce the risk of pulmonary irradiation. Generally, planar scans are acquired after injection of <sup>99m</sup>Tc-MAA into the hepatic artery. However, the validity of this approach is limited by differences in attenuation between liver and lung tissue as well as inaccurate segmentation of the organs. The aim of this study was to evaluate quantitative SPECT/CT for LSF assessment in a prospective clinical cohort. <b>Methods:</b> Fifty consecutive patients intended to undergo SIRT were imaged within 1 h after injection of <sup>99m</sup>Tc-MAA using a SPECT/CT γ-camera. Planar scans of the lung and liver region were acquired in anterior and posterior views, followed by SPECT/CT scans of the thorax and abdomen. Emission data were corrected for scatter, attenuation, and resolution recovery using dedicated software. To quantify the radioactivity concentration in the lung, liver, urinary bladder and remainder of the thoracoabdominal body, volumes of interest were defined on the SPECT/CT images. <sup>99m</sup>Tc-MAA concentrations were calculated as percentage injected dose (%ID). <b>Results:</b> Mean <sup>99m</sup>Tc-MAA uptake in liver and lung accounted for only 79 %ID, whereas 13.1 %ID was present in the remainder of the body. In all patients, LSF as calculated from planar scans accounted for a median of 6.8% (range, 3.4%-32.3%), whereas the SPECT/CT quantitation revealed significantly lower LSF estimates, at a median of 1.9% (range, 0.8%-15.7%) (<i>P</i> < 0.0001, Wilcoxon test). On the basis of planar imaging, dose reduction or even contraindications to SIRT had to be considered in 10 of 50 patients, as their LSF was calculated at 10% or more. In contrast, SPECT/CT quantitation showed substantial shunting in only 2 of the 50 patients. <b>Conclusion:</b> Quantitative SPECT/CT reveals that the LSF is considerably lower than shown on planar imaging. Thus, the resulting dose to the lung parenchyma may be less than conventionally assumed. However, the safety of the SPECT/CT-derived dose range will have to be evaluated.
Pupillographic campimetry: an objective method to measure the visual field
2018-01-25

Abstract Pupillographic campimetry allows measuring the visual field objectively by analyzing the pupil response to perimetric stimuli. One of the drawbacks of this technique, similar to static perimetry, is the need of reliable fixation of the subject. By using stimulus sizes comparable to static perimetry and applying gaze tracking, we enable a retinotopic visual field examination regardless of fixation problems and with an increased stability and improved spatial resolution. Here, we present the results of applying the method in eight normal sighted subjects as well as in three patients suffering from diseases usually diagnosed by perimetry. The results in normal sighted subjects show a reduction in the amplitude of the pupil response with increasing eccentricity as expected. We also demonstrate that gaze-controlled campimetry is able to detect organic visual field defects objectively in a patient group and classify the visual field defects without an organic background. Moreover, we show that our method is able to evaluate the visual field sensitivity loss beyond classical perimetry in patients with late-stage retinitis pigmentosa. Thus, gaze-controlled pupil campimetry can be used in addition to classical perimetry, allowing for an objective monitoring of disease progression, rendering it as a biomarker for novel treatments.
Early Alterations in Operant Performance and Prominent Huntingtin Aggregation in a Congenic F344 Rat Line of the Classical CAGn51trunc Model of Huntington Disease
2018-01-25

The transgenic rat model of Huntington disease expressing a fragment of mutant HTT (tgHD rat) has been thoroughly characterized and reproduces hallmark symptoms of human adult-onset HD. Pursuing the optimization of this model for evaluation of translational therapeutic approaches, the F344 inbred rat strain was considered as advantageous genetic background for the expression of the HD transgenic construct. In the present study, a novel congenic line of the SPRDtgHD transgenic model of HD, carrying 51 CAG repeats, was generated on the F344 rat genetic background. To assess the behavioral phenotype, classical assays investigating motor function, emotion, and sensorimotor gating were applied, along with automated screening of metabolic and activity parameters as well as operant conditioning tasks. The neuropathological phenotype was analyzed by immunohistochemistry and <i>ex vivo</i> magnetic resonance imaging. F344tgHD rats displayed markedly reduced anxiety-like behavior in the social interaction test and elevated impulsivity traits already at 3 months of age. Neuropathologically, reduced striatal volume and pronounced aggregation of mutant huntingtin in several brain regions were detected at later disease stage. In conclusion, the congenic F344tgHD model reproduces key aspects of the human HD phenotype, substantiating its value for translational therapeutic approaches.
Impact of heavy sterile neutrinos on the triple Higgs coupling
2018-01-25

New physics beyond the Standard Model is required to give mass to the light neutrinos. One of the simplest ideas is to introduce new heavy, gauge singlet fermions that play the role of right-handed neutrinos in a seesaw mechanism. They could have large Yukawa couplings to the Higgs boson, affecting the Higgs couplings and in particular the triple Higgs coupling , the measure of which is one of the major goals of the LHC and of future colliders. We present a study of the impact of these heavy neutrinos on at the one-loop level, first in a simplified 3+1 model with one heavy Dirac neutrino and then in the inverse seesaw model. Taking into account all possible experimental constraints, we find that sizeable deviations of the order of 35% are possible, large enough to be detected at future colliders, making the triple Higgs coupling a new, viable observable to constrain neutrino mass models. The effects are generic and are expected in any new physics model including TeV-scale fermions with large Yukawa couplings to the Higgs boson, such as those using the neutrino portal.
Circulating Tumor Cells in Breast Cancer Patients Treated by Neoadjuvant Chemotherapy: A Meta-analysis
2018-01-26

CTC count is an independent and quantitative prognostic factor in early breast cancer patients treated by NCT. It complements current prognostic models based on tumor characteristics and response to therapy.
First in situ evidence of wakes in the far field behind offshore wind farms
2018-01-26

Abstract More than 12 GW of offshore wind turbines are currently in operation in European waters. To optimise the use of the marine areas, wind farms are typically clustered in units of several hundred turbines. Understanding wakes of wind farms, which is the region of momentum and energy deficit downwind, is important for optimising the wind farm layouts and operation to minimize costs. While in most weather situations (unstable atmospheric stratification), the wakes of wind turbines are only a local effect within the wind farm, satellite imagery reveals wind-farm wakes to be several tens of kilometres in length under certain conditions (stable atmospheric stratification), which is also predicted by numerical models. The first direct in situ measurements of the existence and shape of large wind farm wakes by a specially equipped research aircraft in 2016 and 2017 confirm wake lengths of more than tens of kilometres under stable atmospheric conditions, with maximum wind speed deficits of 40%, and enhanced turbulence. These measurements were the first step in a large research project to describe and understand the physics of large offshore wakes using direct measurements, together with the assessment of satellite imagery and models.
Snapshot‐CEST: Optimizing spiral‐centric‐reordered gradient echo acquisition for fast and robust 3D CEST MRI at 9.4 T
2018-01-26

Gradient echo (GRE)‐based acquisition provides a robust readout method for chemical exchange saturation transfer (CEST) at ultrahigh field (UHF). To develop a snapshot‐CEST approach, the transient GRE signal and point spread function were investigated in detail, leading to optimized measurement parameters and reordering schemes for fast and robust volumetric CEST imaging. Simulation of the transient GRE signal was used to determine the optimal sequence parameters and the maximum feasible number of k ‐space lines. Point spread function analysis provided an insight into the induced k ‐space filtering and the performance of different rectangular reordering schemes in terms of blurring, signal‐to‐noise ratio (SNR) and relaxation dependence. Simulation results were confirmed in magnetic resonance imaging (MRI) measurements of healthy subjects. Minimal repetition time (TR) is beneficial for snapshot‐GRE readout. At 9.4 T, for TR = 4 ms and optimal flip angle close to the Ernst angle, a maximum of 562 k ‐space lines can be acquired after a single presaturation, providing decent SNR with high image quality. For spiral‐centric reordered k ‐space acquisition, the image quality can be further improved using a rectangular spiral reordering scheme adjusted to the field of view. Application of the derived snapshot‐CEST sequence for fast imaging acquisition in the human brain at 9.4 T shows excellent image quality in amide and nuclear Overhauser enhancement (NOE), and enables guanidyl CEST detection. The proposed snapshot‐CEST establishes a fast and robust volumetric CEST approach ready for the imaging of known and novel exchange‐weighted contrasts at UHF.
Emotionalization in Science Communication: The Impact of Narratives and Visual Representations on Knowledge Gain and Risk Perception
2018-01-26

The communication of scientific information plays an increasingly important role for scientists and scientific institutions. This is especially true of institutions in the field of biodiversity and conservation research, since the transfer of research results to the public is a prerequisite for decision-making, and the success of conservation measures often depends on public acceptance or active contribution. To have the desired impact, science communication in the context of human–wildlife interactions must enable recipients to (1) gain valid knowledge, (2) form an attitude toward the subject matter, and (3) develop an adequate understanding of the risks and dangers associated with human–wildlife interactions, which are usually overestimated by the general public. Using the topic of foxes in urban habitats, we investigated the role of emotionalization in science communication. In a laboratory experiment with 127 university students (91 females), we manipulated textual and visual features in an information brochure about foxes and examined their impact on people’s knowledge gain, attitude development, and modified risk perception. In particular, we compared a narrative presentation to a non-narrative list of facts and examined the use of photographs of young foxes. We found a positive development in all of the outcome variables from the pre- to the posttest (more knowledge, more positive attitude, lower risk perception). We also found an interaction effect of text type and visualization on knowledge gain that highlighted the importance of the fit between text type and visualization. In contrast to our expectations, we did not find any differential effects of specific treatments on attitude development. Finally, we found a main effect of text type on modified risk perception, indicating less reduction of risk perception with a narrative article than with a fact list. We discuss our findings with respect to the role of emotionalization in science communication, stressing that it is particularly important to achieve a suitable fit between textual and visual forms of emotionalization, depending on the goal of communication. We also discuss possible explanations as to why some hypotheses were not supported by the data. In our concluding statements, we refer to limitations of the present study and address implications for future research.