bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sandstone 3D compositional microstructure analysis with synchrotron-based multi-energy x-ray micro-CT
Authors: Kong Huihua , Li Ruru , Yang Yushuang , Bai Bin , Wang Haipeng 
Published: April 2020

Abstract
Three-dimensional (3D) characterization of materials microstructure is important in understanding their physical and chemical properties. In this paper, the compositional microstructure of a sandstone sample from Yaodian area of Yan’an in Erdors Basin is analyzed using synchrotron-based multi-energy x-ray micro-CT data. The x-ray CT data of the sample are acquired at beam energies 25 KeV, 35 KeV and 45 KeV. The strip artifact in the sinogram images are corrected with a least square fitting method. The corrected sinogram image data are reconstructed with the X-tract software, and the reconstructed images under different energy spectra are calibrated. Finally, the multi-energy least square segmentation method is used to characterize the 3D microstructure of sandstone sample with the Data-Constrained Modeling (DCM) software. The results show that the sample has 71.8% of quartz and albite which is displayed as blue, calcite (22.3%) is displayed as red, pyrite (0.6%) is displayed as yellow and porosity (5.3%) is displayed as white.
Photocatalytic upgrading α-Fe2O3 nanoparticles by incorporating MoS2/rGO nanosheets
Authors: Lejbini M Behtaj , Sangpour P , Tajabadi F , Kolahi A 
Published: April 2020

Abstract

α-Fe2O3/MoS2/rGO nanocomposites was prepared by a two-step hydrothermal method and characterized by XRD, FESEM, EDS, FTIR, and UV–vis absorption spectroscopy. The results confirmed the formation of α-Fe2O3/MoS2-rGO (10 wt%) nanocomposites were composed of hematite nanoparticles with particle size of 30 nm and MoS2/rGO composite nanosheets with maximum sheet thickness of ∼ 10 nm. Upon addition of MoS2-rGO (8.0 wt%) nanosheets, the band gap of α-Fe2O3 nanoparticles decreased from 2.3 to 1.7 eV that was accompanied by light absorption enhancement. Owing to synergetic effect between rGO and MoS2 nanosheets leading to suppression of charge carrier recombination, prolongation of charge carrier lifetime, improvement of the interfacial charge transfer and increase in the number of active sites in α-Fe2O3 nanoparticles, as-synthesized α-Fe2O3/MoS2-rGO (10 wt%) nanocomposites nanocomposite showed highly enhanced photocatalytic performance for Rh B degradation under light irradiation so that complete degradation of Rh B organic dye was achieved within 30 min.
COVID-19 in older people: a rapid clinical review
Authors: Lithander Fiona E , Neumann Sandra , Tenison Emma , Lloyd Katherine , Welsh Tomas J , Rodrigues Jonathan C L , Higgins Julian P T , Scourfield Lily , Christensen Hannah , Haunton Victoria J , Henderson Emily J 
Published: April 2020

Abstract

Introduction
the COVID-19 pandemic poses a high risk to older people. The aim of this article is to provide a rapid overview of the COVID-19 literature, with a specific focus on older adults. We frame our findings within an overview of the disease and have also evaluated the inclusion of older people within forthcoming clinical trials.

Methods
we searched PubMed and bioRxiv/medRxiv to identify English language papers describing the testing, treatment and prognosis of COVID-19. PubMed and bioRxiv/medRxiv searches took place on 20 and 24 March 2020, respectively.

Results
screening of over 1,100 peer-reviewed and pre-print papers yielded n = 22 on COVID-19 testing, n = 15 on treatment and n = 13 on prognosis. Viral polymerase chain reaction (PCR) and serology are the mainstays of testing, but a positive diagnosis may be increasingly supported by radiological findings. The current evidence for the effectiveness of antiviral, corticosteroid and immunotherapies is inconclusive, although trial data are largely based on younger people. In addition to age, male gender and comorbidities, specific laboratory and radiology findings are important prognostic factors. Evidence suggests that social distancing policies could have important negative consequences, particularly if in place for an extended period.

Conclusion
given the established association between increasing age and poor prognosis in COVID-19, we anticipate that this rapid review of the current and emergent evidence might form a basis on which future work can be established. Exclusion of older people, particularly those with comorbidities, from clinical trials is well recognised and is potentially being perpetuated in the field of current COVID-19 research.
Interobserver Variability in Ductal Carcinoma In Situ of the Breast
Authors: Van Bockstal Mieke R , Berlière Martine , Duhoux Francois P , Galant Christine 
Published: April 2020

AbstractObjectivesSince most patients with ductal carcinoma in situ (DCIS) of the breast are treated upon diagnosis, evidence on its natural progression to invasive carcinoma is limited. It is estimated that around half of the screen-detected DCIS lesions would have remained indolent if they had never been detected. Many patients with DCIS are therefore probably overtreated. Four ongoing randomized noninferiority trials explore active surveillance as a treatment option. Eligibility for these trials is mainly based on histopathologic features. Hence, the call for reproducible histopathologic assessment has never sounded louder.MethodsHere, the available classification systems for DCIS are discussed in depth.ResultsThis comprehensive review illustrates that histopathologic evaluation of DCIS is characterized by significant interobserver variability. Future digitalization of pathology, combined with development of deep learning algorithms or so-called artificial intelligence, may be an innovative solution to tackle this problem. However, implementation of digital pathology is not within reach for each laboratory worldwide. An alternative classification system could reduce the disagreement among histopathologists who use “conventional” light microscopy: the introduction of dichotomous histopathologic assessment is likely to increase interobserver concordance.ConclusionsReproducible histopathologic assessment is a prerequisite for robust risk stratification and adequate clinical decision-making. Two-tier histopathologic assessment might enhance the quality of care.
Lack of strong selection pressures maintains wide variation in floral traits in a food-deceptive orchid
Authors: Jacquemyn Hans , Brys Rein 
Published: April 2020

Abstract

Background and Aims
Angiosperms vary remarkably in traits such as colour, size and shape of flowers, yet such variation generally tends to be low within species. In deceptive orchids, however, large variation in floral traits has been described, not only between but also within populations. Nonetheless, the factors driving variation in floral traits in deceptive orchids remain largely unclear.

Methods
To identify determinants of variation in floral traits, we investigated patterns of fruit set and selection gradients in the food-deceptive orchid Orchis purpurea, which typically presents large within-population variation in the colour and size of the flowers. Using long-term data, fruit set was quantified in two populations over 16 consecutive years (2004–2019). Artificial hand pollination was performed to test the hypothesis that fruit set was pollinator-limited and that selfing led to decreased seed set and viability. Annual variation (2016–2019) in selection gradients was calculated for three colour traits (brightness, contrast and the number of spots on the labellum), flower size (spur length, labellum length and width) and plant size (number of flowers, plant height).

Key Results
Fruit set was, on average, low (~12 %) and severely pollinator-limited. Opportunities for selection varied strongly across years, but we found only weak evidence for selection on floral traits. In contrast, there was strong and consistent positive selection on floral display. Selfing led to reduced production of viable seeds and hence severe inbreeding depression (δ = 0.38).

Conclusion
Overall, these results demonstrate that the large variation in flower colour and size that is regularly observed in natural O. purpurea populations is maintained by the consistent lack of strong selection pressures on these traits through time.
The role of multiple reproductive barriers: strong post-pollination interactions govern cytotype isolation in a tetraploid–octoploid contact zone
Authors: Castro Mariana , Loureiro João , Husband Brian C , Castro Sílvia 
Published: April 2020

Abstract

Background and Aims
Polyploidy is an important contributor to sympatric speciation and assortative mating is a key mechanism driving cytotype interactions in contact zones. While strong reproductive barriers can mediate the coexistence of different cytotypes in sympatry, positive frequency-dependent mating disadvantage ultimately drives the transition to single-ploidy populations. However, comprehensive estimates of reproductive isolation among cytotypes and across multiple barriers are rare. We quantify the strength of isolation across multiple reproductive stages in a tetraploid–octoploid contact zone to understand the potential for coexistence.

Methods
Assortative mating due to flowering asynchrony, pollinator behaviour, morphological overlap, self-fertilization and gametic competition between tetraploid and octoploid Gladiolus communis in a contact zone in the Western Iberian Peninsula were assessed in natural and experimental populations to quantify reproductive isolation (RI) between cytotypes.

Key Results
Tetraploids and octoploids have a high degree of overlap in flowering time and similar floral morphology, and are visited by generalist insects without cytotype foraging preferences, resulting in weak pre-pollination RI (from 0.00 to 0.21). In contrast, post-pollination isolation resulting from gametic selection was a strong barrier to inter-cytotype mating, with ploidy composition in stigmatic pollen loads determining the levels of RI (from 0.54 to 1.00). Between-cytotype cross-incompatibility was relatively high (RI from 0.54 to 0.63) as was isolation acquired through self-pollination (RI of 0.59 in tetraploids and 0.39 in octoploids).

Conclusions
Total RI was high for both tetraploids (from 0.90 to 1.00) and octoploids (from 0.78 to 0.98). Such high rates of assortative mating will enable cytotype coexistence in mixed-ploidy populations by weakening the impacts of minority cytotype exclusion. This study reveals the key role of gametic selection in cytotype siring success and highlights the importance of comprehensive estimates across multiple reproductive barriers to understand cytotype interactions at contact zones.
Slow blood-to-brain transport underlies enduring barrier dysfunction in American football players
Authors: Veksler Ronel , Vazana Udi , Serlin Yonatan , Prager Ofer , Ofer Jonathan , Shemen Nofar , Fisher Andrew M , Minaeva Olga , Hua Ning , Saar-Ashkenazy Rotem , Benou Itay , Riklin-Raviv Tammy , Parker Ellen , Mumby Griffin , Kamintsky Lyna , Beyea Steven , Bowen Chris V , Shelef Ilan , O’Keeffe Eoin , Campbell Matthew , Kaufer Daniela , Goldstein Lee E , Friedman Alon 
Published: April 2020

Abstract
Repetitive mild traumatic brain injury in American football players has garnered increasing public attention following reports of chronic traumatic encephalopathy, a progressive tauopathy. While the mechanisms underlying repetitive mild traumatic brain injury-induced neurodegeneration are unknown and antemortem diagnostic tests are not available, neuropathology studies suggest a pathogenic role for microvascular injury, specifically blood–brain barrier dysfunction. Thus, our main objective was to demonstrate the effectiveness of a modified dynamic contrast-enhanced MRI approach we have developed to detect impairments in brain microvascular function. To this end, we scanned 42 adult male amateur American football players and a control group comprising 27 athletes practicing a non-contact sport and 26 non-athletes. MRI scans were also performed in 51 patients with brain pathologies involving the blood–brain barrier, namely malignant brain tumours, ischaemic stroke and haemorrhagic traumatic contusion. Based on data from prolonged scans, we generated maps that visualized the permeability value for each brain voxel. Our permeability maps revealed an increase in slow blood-to-brain transport in a subset of amateur American football players, but not in sex- and age-matched controls. The increase in permeability was region specific (white matter, midbrain peduncles, red nucleus, temporal cortex) and correlated with changes in white matter, which were confirmed by diffusion tensor imaging. Additionally, increased permeability persisted for months, as seen in players who were scanned both on- and off-season. Examination of patients with brain pathologies revealed that slow tracer accumulation characterizes areas surrounding the core of injury, which frequently shows fast blood-to-brain transport. Next, we verified our method in two rodent models: rats and mice subjected to repeated mild closed-head impact injury, and rats with vascular injury inflicted by photothrombosis. In both models, slow blood-to-brain transport was observed, which correlated with neuropathological changes. Lastly, computational simulations and direct imaging of the transport of Evans blue-albumin complex in brains of rats subjected to recurrent seizures or focal cerebrovascular injury suggest that increased cellular transport underlies the observed slow blood-to-brain transport. Taken together, our findings suggest dynamic contrast-enhanced-MRI can be used to diagnose specific microvascular pathology after traumatic brain injury and other brain pathologies.
Modelling and treating GRIN2A developmental and epileptic encephalopathy in mice
Authors: Amador Ariadna , Bostick Christopher D , Olson Heather , Peters Jurrian , Camp Chad R , Krizay Daniel , Chen Wenjuan , Han Wei , Tang Weiting , Kanber Ayla , Kim Sukhan , Teoh JiaJie , Sah Megha , Petri Sabrina , Paek Hunki , Kim Ana , Lutz Cathleen M , Yang Mu , Myers Scott J , Bhattacharya Subhrajit , Yuan Hongjie , Goldstein David B , Poduri Annapurna , Boland Michael J , Traynelis Stephen F , Frankel Wayne N 
Published: April 2020

AbstractNMDA receptors play crucial roles in excitatory synaptic transmission. Rare variants in GRIN2A encoding the GluN2A subunit are associated with a spectrum of disorders, ranging from mild speech and language delay to intractable neurodevelopmental disorders, including but not limited to developmental and epileptic encephalopathy. A de novo missense variant, p.Ser644Gly, was identified in a child with this disorder, and Grin2a knock-in mice were generated to model and extend understanding of this intractable childhood disease. Homozygous and heterozygous mutant mice exhibited altered hippocampal morphology at 2 weeks of age, and all homozygotes exhibited lethal tonic-clonic seizures by mid-third week. Heterozygous adults displayed susceptibility to induced generalized seizures, hyperactivity, repetitive and reduced anxiety behaviours, plus several unexpected features, including significant resistance to electrically-induced limbic seizures and to pentylenetetrazole induced tonic-clonic seizures. Multielectrode recordings of neuronal networks revealed hyperexcitability and altered bursting and synchronicity. In heterologous cells, mutant receptors had enhanced NMDA receptor agonist potency and slow deactivation following rapid removal of glutamate, as occurs at synapses. NMDA receptor-mediated synaptic currents in heterozygous hippocampal slices also showed a prolonged deactivation time course. Standard anti-epileptic drug monotherapy was ineffective in the patient. Introduction of NMDA receptor antagonists was correlated with a decrease in seizure burden. Chronic treatment of homozygous mouse pups with NMDA receptor antagonists significantly delayed the onset of lethal seizures but did not prevent them. These studies illustrate the power of using multiple experimental modalities to model and test therapies for severe neurodevelopmental disorders, while revealing significant biological complexities associated with GRIN2A developmental and epileptic encephalopathy.
Medial Prefrontal Cortex Represents the Object-Based Cognitive Map When Remembering an Egocentric Target Location
Authors: Zhang Bo , Naya Yuji 
Published: April 2020

Abstract
A cognitive map, representing an environment around oneself, is necessary for spatial navigation. However, compared with its constituent elements such as individual landmarks, neural substrates of coherent spatial information, which consists in a relationship among the individual elements, remain largely unknown. The present study investigated how the brain codes map-like representations in a virtual environment specified by the relative positions of three objects. Representational similarity analysis revealed an object-based spatial representation in the hippocampus (HPC) when participants located themselves within the environment, while the medial prefrontal cortex (mPFC) represented it when they recollected a target object’s location relative to their self-body. During recollection, task-dependent functional connectivity increased between the two areas implying exchange of self-location and target location signals between the HPC and mPFC. Together, the object-based cognitive map, whose coherent spatial information could be formed by objects, may be recruited in the HPC and mPFC for complementary functions during navigation, which may generalize to other aspects of cognition, such as navigating social interactions.
Neural Pattern Similarity Unveils the Integration of Social Information and Aversive Learning
Authors: Undeger Irem , Visser Renée M , Olsson Andreas 
Published: April 2020

Abstract
Attributing intentions to others’ actions is important for learning to avoid their potentially harmful consequences. Here, we used functional magnetic resonance imaging multivariate pattern analysis to investigate how the brain integrates information about others’ intentions with the aversive outcome of their actions. In an interactive aversive learning task, participants (n = 33) were scanned while watching two alleged coparticipants (confederates)—one making choices intentionally and the other unintentionally—leading to aversive (a mild shock) or safe (no shock) outcomes to the participant. We assessed the trial-by-trial changes in participants’ neural activation patterns related to observing the coparticipants and experiencing the outcome of their choices. Participants reported a higher number of shocks, more discomfort, and more anger to shocks given by the intentional player. Intentionality enhanced responses to aversive actions in the insula, anterior cingulate cortex, inferior frontal gyrus, dorsal medial prefrontal cortex, and the anterior superior temporal sulcus. Our findings indicate that neural pattern similarities index the integration of social and threat information across the cortex.
Predominant Qualities Evoked by Quinine, Sucrose, and Capsaicin Associate With PROP Bitterness, but not TAS2R38 Genotype
Authors: Nolden Alissa A , McGeary John E , Hayes John E 
Published: April 2020

Abstract
Genetic variability in the ability to taste thiourea compounds has been studied for 80+ years. Over the last 3 decades, many studies have reported perceived intensity of concentrated propylthiouracil (PROP) associates with greater intensity from a broad range of stimuli, including nonbitter tastants, irritants, and retronasally delivered odorants. Thus, PROP phenotype has become a common measure of individual differences in orosensation. Much, but not all, of the phenotypic variation in PROP bitterness is explained by TAS2R38 polymorphisms. While differences in PROP bitterness are clearly due to genetic variation, mechanistically it is challenging to envision how this receptor (narrowly tuned to the N–C=S moiety) relates to overall orosensory response. Here, we report data for 200+ individuals who had been genotyped for TAS2R38 and phenotyped for PROP in a laboratory setting. Participants also reported the intensity of quinine, capsaicin, and sucrose on a general Labeled Magnitude Scale. Our data recapitulate earlier reports associating PROP bitterness with the intensity of the predominant qualities of sucrose, quinine, and capsaicin; however, we also find correlations between the intensities of sucrose, quinine, and capsaicin were much stronger with each other than with PROP. As expected, TAS2R38 diplotype did not associate with the intensity of sucrose, quinine, or capsaicin. The strength of PROP–capsaicin and PROP–sucrose relationships increased after grouping participants by TAS2R38 diplotype, with the greatest increases in association observed within homozygotes. Collectively, this suggests the suprathreshold intensity of PROP is a confounded phenotype that captures both genetic variation specific to N–C=S compounds and overall orosensation.
First Reported Nosocomial Outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 in a Pediatric Dialysis Unit
Authors: Schwierzeck Vera , König Jens Christian , Kühn Joachim , Mellmann Alexander , Correa-Martínez Carlos Luis , Omran Heymut , Konrad Martin , Kaiser Thomas , Kampmeier Stefanie 
Published: April 2020

AbstractBackgroundCoronavirus disease 2019 (COVID-19) is a life-threatening respiratory condition caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and was initially detected in China in December 2019. Currently, in Germany &gt;140 000 cases of COVID-19 are confirmed. Here we report a nosocomial outbreak of SARS-CoV-2 infections in the pediatric dialysis unit of the University Hospital Münster (UHM).MethodsSingle-step real-time reverse-transcription polymerase chain reaction (rRT-PCR) from nasopharyngeal swabs was used to diagnose the index patient and identify infected contacts. Epidemiological links were analyzed by patient interviews and medical record reviews. In addition, each contact was assessed for exposure to the index case and monitored for clinical symptoms. Cycle threshold (Ct) values of all positive test results were compared between symptomatic and asymptomatic cases.ResultsForty-eight cases were involved in this nosocomial outbreak. Nine contact cases developed laboratory-confirmed COVID-19 infections. Two SARS-CoV-2–positive cases remained clinically asymptomatic. Eleven cases reported flulike symptoms without positive results. Ct values were significantly lower in cases presenting typical COVID-19 symptoms, suggesting high viral shedding (P = .007).ConclusionsPerson-to-person transmission was at the heart of a hospital outbreak of SARS-CoV-2 between healthcare workers (HCWs) and patients in the pediatric dialysis unit at UHM. Semiquantitative rRT-PCR results suggest that individuals with high viral load pose a risk to spread SARS-CoV-2 in the hospital setting. Our epidemiological observation highlights the need to develop strategies to trace and monitor SARS-CoV-2–infected HCWs to prevent COVID-19 outbreaks in the hospital setting.