bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluctuation induced conductivity and pseudogap state studies of Bi1.6Pb0.4Sr2Ca2Cu3O10+δ superconductor added with ZnO nanoparticles
Authors: Aftabi Ali , Mozaffari Morteza 
Published: February 2021

AbstractThe major limitations of the Bi1.6Pb0.4Sr2Ca2Cu3O10+δ superconductor are weak flux pinning capability and weak inter-grains coupling that lead to a low critical current density and low critical magnetic field which impedes the suppleness of this material towards practical applications. The addition of nanoscales impurities can create artificial pining centers that may improve flux pinning capability and intergranular coupling. In this work, the influences of ZnO nanoparticles on the superconducting parameters and pseudogap properties of the Bi1.6Pb0.4Sr2Ca2Cu3O10+δ superconductor are investigated using fluctuation induced conductivity analyses. Results demonstrate that the ZnO nanoparticles addition improves the formation of the Bi1.6Pb0.4Sr2Ca2Cu3O10+δ phase significantly. Various superconducting parameters include coherence length along c-axis (ξc(0)), penetration depth (λpd(0)), Fermi velocity (vF), Fermi energy (EF), lower and upper critical magnetic fields (Bc1(0) and Bc2(0) respectively) and critical current density (Jc(0)), are estimated for samples with different amounts of ZnO nanoparticles. It is found that the values of the Bc1(0), Bc2(0), and Jc(0) are improved significantly in the 0.2 wt% ZnO added sample in comparison to the ZnO-free sample. The magnitude and temperature dependence of the pseudogap Δ*(T) is calculated using the local pairs model. The obtained values of Tpair, the temperature at which local pairs are transformed from strongly coupled bosons into the fluctuating Cooper pairs, increases as the added ZnO nanoparticles concentration enhances up to 0.2 wt%. Also, the estimated values for the superconducting gap at T = 0 K (Δ(0)) are decreased from about 26 meV in ZnO-free sample to about 22 meV in 0.2 wt% ZnO added sample and then increases for higher values of additive.
Life-long brain compensatory responses to galactic cosmic radiation exposure
Authors: Miry Omid , Zhang Xiao-lei , Vose Linnea R. , Gopaul Katisha R. , Subah Galadu , Moncaster Juliet A. , Wojnarowicz Mark W. , Fisher Andrew M. , Tagge Chad A. , Goldstein Lee E. , Stanton Patric K. 
Published: February 2021

AbstractGalactic cosmic radiation (GCR) composed of high-energy, heavy particles (HZE) poses potentially serious hazards to long-duration crewed missions in deep space beyond earth’s magnetosphere, including planned missions to Mars. Chronic effects of GCR exposure on brain structure and cognitive function are poorly understood, thereby limiting risk reduction and mitigation strategies to protect against sequelae from exposure during and after deep-space travel. Given the selective vulnerability of the hippocampus to neurotoxic insult and the importance of this brain region to learning and memory, we hypothesized that GCR-relevant HZE exposure may induce long-term alterations in adult hippocampal neurogenesis, synaptic plasticity, and hippocampal-dependent learning and memory. To test this hypothesis, we irradiated 3-month-old male and female mice with a single, whole-body dose of 10, 50, or 100 cGy 56Fe ions (600 MeV, 181 keV/μm) at Brookhaven National Laboratory. Our data reveal complex, dynamic, time-dependent effects of HZE exposure on the hippocampus. Two months post exposure, neurogenesis, synaptic plasticity and learning were impaired compared to sham-irradiated, age-matched controls. By six months post-exposure, deficits in spatial learning were absent in irradiated mice, and synaptic potentiation was enhanced. Enhanced performance in spatial learning and facilitation of synaptic plasticity in irradiated mice persisted 12 months post-exposure, concomitant with a dramatic rebound in adult-born neurons. Synaptic plasticity and spatial learning remained enhanced 20 months post-exposure, indicating a life-long influence on plasticity and cognition from a single exposure to HZE in young adulthood. These findings suggest that GCR-exposure can persistently alter brain health and cognitive function during and after long-duration travel in deep space.
Amylose starch with no detectable branching developed through DNA-free CRISPR-Cas9 mediated mutagenesis of two starch branching enzymes in potato
Authors: Zhao Xue , Jayarathna Shishanthi , Turesson Helle , Fält Ann-Sofie , Nestor Gustav , González Matías N. , Olsson Niklas , Beganovic Mirela , Hofvander Per , Andersson Roger , Andersson Mariette 
Published: February 2021

AbstractDNA-free genome editing was used to induce mutations in one or two branching enzyme genes (Sbe) in tetraploid potato to develop starch with an increased amylose ratio and elongated amylopectin chains. By using ribonucleoprotein (RNP) transfection of potato protoplasts, a mutation frequency up to 72% was achieved. The large variation of mutations was grouped as follows: Group 1 lines with all alleles of Sbe1 mutated, Group 2 lines with all alleles of Sbe1 as well as two to three alleles of Sbe2 mutated and Group 3 lines having all alleles of both genes mutated. Starch from lines in Group 3 was found to be essentially free of amylopectin with no detectable branching and a chain length (CL) distribution where not only the major amylopectin fraction but also the shortest amylose chains were lost. Surprisingly, the starch still formed granules in a low-ordered crystalline structure. Starch from lines of Group 2 had an increased CL with a higher proportion of intermediate-sized chains, an altered granule phenotype but a crystalline structure in the granules similar to wild-type starch. Minor changes in CL could also be detected for the Group 1 starches when studied at a higher resolution.
Geochemical alkalinity and acidity as preferential site-specific for three lineages liverwort of Aneura pinguis cryptic species A
Authors: Bączkiewicz Alina , Diatta Jean , Drapikowska Maria , Rodkiewicz Patrycja , Sawicki Jakub , Szczecińska Monika , Buczkowska Katarzyna 
Published: February 2021

AbstractThe study focused on the verification of the preferential site-specific concept hypothesizing, that mineral elements could be playing an initiating role in the biological speciation withinAneura pinguiscryptic species.A. pinguisspecies A and soil materials were collected from three ecological sites of Poland. They underwent genetic (Aneura pinguis) and chemical analyses (soil materials) for pH, total and water soluble (active) forms of Ca, Mg, K, Na fractions. Data revealed trends in the site preference of three genetic lineages (A1, A2 and A3) ofA. pinguiscryptic species A. Lineage adaptability index Ca/(Mg + K + Na) reflecting the dynamic character of site pH implied, that lineages A1 and A2 were both calciphilous. The A3 lineages were intrinsically acidophilous and this characteristics was also observed at some A1 lineages. Site concentrations of Ca and in some cases Mg too were crucial in shaping pH, but this process could have been controlled by each mineral element, individually. Calciphilous or acidophilousA. pinguisspecies may be “remotely” attracted by high or low Ca (or Mg) concentrations, for alkalinity or acidity emergence, respectively. Mineral richness at investigated ecological sites has possibly initiated opportunistic and specific site colonisation byA. pinguislineages.
Positive symptom phenotypes appear progressively in “EDiPS”, a new animal model of the schizophrenia prodrome
Authors: Petty Alice , Cui Xiaoying , Ali Asad , Du Zilong , Srivastav Sunil , Kesby James P. , Kirik Deniz , Howes Oliver , Eyles Darryl 
Published: February 2021

AbstractAn increase in dopamine (DA) synthesis capacity in the dorsal striatum (DS) during the prodromal stage of schizophrenia becomes more pronounced as patients progress to the full disorder. Understanding this progression is critical to intervening in disease course. We developed an animal model—Enhanced Dopamine in Prodromal Schizophrenia (EDiPS)—which uses a genetic construct to increase DA synthesis capacity in the DS of male rats. We assessed pre-pulse inhibition (PPI) and amphetamine (AMPH)-induced locomotion (0.6 mg/kg) in EDiPS animals longitudinally after post-natal day 35 (when the EDiPS construct is administered). We also assessed their response to repeated acute restraint stress. In adult EDiPS animals, we measured baseline and evoked extracellular DA levels, and their stereotyped responses to 5 mg/kg AMPH. AMPH-induced hyperlocomotion was apparent in EDiPS animals 6-weeks after construct administration. There was an overall PPI deficit in EDiPS animals across all timepoints, however the stress response of EDiPS animals was unaltered. Adult EDiPS animals show normal baseline and potassium-evoked DA release in the DS. These findings suggest that key behavioural phenotypes in EDiPS animals show a progressive onset, similar to that demonstrated by patients as they transition to schizophrenia. The EDiPS model could therefore be used to investigate the molecular mechanisms underlying the prodrome of schizophrenia.
Modeling COVID-19 epidemics in an Excel spreadsheet to enable first-hand accurate predictions of the pandemic evolution in urban areas
Authors: Alvarez Mario Moisés , González-González Everardo , Trujillo-de Santiago Grissel 
Published: February 2021

AbstractCOVID-19, the first pandemic of this decade and the second in less than 15 years, has harshly taught us that viral diseases do not recognize boundaries; however, they truly do discriminate between aggressive and mediocre containment responses. We present a simple epidemiological model that is amenable to implementation in Excel spreadsheets and sufficiently accurate to reproduce observed data on the evolution of the COVID-19 pandemics in different regions [i.e., New York City (NYC), South Korea, Mexico City]. We show that the model can be adapted to closely follow the evolution of COVID-19 in any large city by simply adjusting parameters related to demographic conditions and aggressiveness of the response from a society/government to epidemics. Moreover, we show that this simple epidemiological simulator can be used to assess the efficacy of the response of a government/society to an outbreak. The simplicity and accuracy of this model will greatly contribute to democratizing the availability of knowledge in societies regarding the extent of an epidemic event and the efficacy of a governmental response.
Digital PCR for high sensitivity viral detection in false-negative SARS-CoV-2 patients
Authors: Poggio Paolo , Songia Paola , Vavassori Chiara , Ricci Veronica , Banfi Cristina , Barbieri Silvia Stella , Garoffolo Gloria , Myasoedova Veronika A. , Piacentini Luca , Raucci Angela , Scopece Alessandro , Sommariva Elena , Vinci Maria Cristina , Carcione Davide , Biondi Maria Luisa , Mancini Maria Elisabetta , Formenti Alberto , Andreini Daniele , Assanelli Emilio M. , Agostoni Piergiuseppe , Camera Marina , Colombo Gualtiero I. , Pesce Maurizio 
Published: February 2021

AbstractPatients requiring diagnostic testing for coronavirus disease 2019 (COVID-19) are routinely assessed by reverse-transcription quantitative polymerase chain reaction (RT-qPCR) amplification of Sars-CoV-2 virus RNA extracted from oro/nasopharyngeal swabs. Despite the good specificity of the assays certified for SARS-CoV-2 molecular detection, and a theoretical sensitivity of few viral gene copies per reaction, a relatively high rate of false negatives continues to be reported. This is an important challenge in the management of patients on hospital admission and for correct monitoring of the infectivity after the acute phase. In the present report, we show that the use of digital PCR, a high sensitivity method to detect low amplicon numbers, allowed us to correctly detecting infection in swab material in a significant number of false negatives. We show that the implementation of digital PCR methods in the diagnostic assessment of COVID-19 could resolve, at least in part, this timely issue.
Contribution of Vouacapoua americana fruit-fall to the release of biomass in a lowland Amazon forest
Authors: Chuma Victor Juan Ulises Rodriguez , Norris Darren 
Published: February 2021

AbstractFruit-fall provides the transfer of biomass and nutrients between forest strata and remains a poorly understood component of Amazon forest systems. Here we detail fruit-fall patterns including those of Vouacapoua americana a Critically Endangered timber species across 25 km2 of lowland Amazon forest in 2016. We use multi-model comparisons and an ensemble model to explain and interpolate fruit-fall data collected in 90 plots (totaling 4.42 ha). By comparing patterns in relation to observed and remotely sensed biomass estimates we establish the seasonal contribution of V. americana fruit-fall biomass. Overall fruit-fall biomass was 44.84 kg ha−1 month−1 from an average of 44.55 species per hectare, with V. americana dominating both the number and biomass of fallen fruits (43% and 64%, number and biomass respectively). Spatially explicit interpolations provided an estimate of 114 Mg dry biomass of V. americana fruit-fall across the 25 km2 area. This quantity represents the rapid transfer by a single species of between 0.01 and 0.02% of the overall above ground standing biomass in the area. These findings support calls for a more detailed understanding of the contribution of individual species to carbon and nutrient flows in tropical forest systems needed to evaluate the impacts of population declines predicted from short (< 65 year) logging cycles.
Click-correlative light and electron microscopy (click-AT-CLEM) for imaging and tracking azido-functionalized sphingolipids in bacteria
Authors: Peters Simon , Kaiser Lena , Fink Julian , Schumacher Fabian , Perschin Veronika , Schlegel Jan , Sauer Markus , Stigloher Christian , Kleuser Burkhard , Seibel Jürgen , Schubert-Unkmeir Alexandra 
Published: February 2021

AbstractSphingolipids, including ceramides, are a diverse group of structurally related lipids composed of a sphingoid base backbone coupled to a fatty acid side chain and modified terminal hydroxyl group. Recently, it has been shown that sphingolipids show antimicrobial activity against a broad range of pathogenic microorganisms. The antimicrobial mechanism, however, remains so far elusive. Here, we introduce ‘click-AT-CLEM’, a labeling technique for correlated light and electron microscopy (CLEM) based on the super-resolution array tomography (srAT) approach and bio-orthogonal click chemistry for imaging of azido-tagged sphingolipids to directly visualize their interaction with the model Gram-negative bacterium Neisseria meningitidis at subcellular level. We observed ultrastructural damage of bacteria and disruption of the bacterial outer membrane induced by two azido-modified sphingolipids by scanning electron microscopy and transmission electron microscopy. Click-AT-CLEM imaging and mass spectrometry clearly revealed efficient incorporation of azido-tagged sphingolipids into the outer membrane of Gram-negative bacteria as underlying cause of their antimicrobial activity.
Broadband optical spin dependent reflection in self-assembled GaAs-based nanowires asymmetrically hybridized with Au
Authors: Petronijevic Emilija , Belardini Alessandro , Leahu Grigore , Hakkarainen Teemu , Piton Marcelo Rizzo , Koivusalo Eero , Sibilia Concita 
Published: February 2021

AbstractHybridization of semiconductor nanostructures with asymmetric metallic layers offers new paths to circular polarization control and chiral properties. Here we study, both experimentally and numerically, chiral properties of GaAs-based nanowires (NWs) which have two out of six sidewalls covered by Au. Sparse ensembles of vertical, free-standing NWs were fabricated by means of lithography-free self-assembled technique on Si substrates and subsequently covered by Au using tilted evaporation. We report on optical spin-dependent specular reflection in the 680–1000 nm spectral range when the orientation of the golden layers follows the rule of extrinsic chirality. The analysis shows reflection peaks of the chiral medium whose intensity is dependent on the light handedness. We further propose a novel, time-efficient numerical method that enables a better insight into the far-field intensity and distribution of the scattered light from a sparse NW ensembles. The measurements done on three different samples in various orientations show good agreement with theoretical predictions over a broad wavelength range.
Annotation of chromatin states in 66 complete mouse epigenomes during development
Authors: van der Velde Arjan , Fan Kaili , Tsuji Junko , Moore Jill E. , Purcaro Michael J. , Pratt Henry E. , Weng Zhiping 
Published: February 2021

AbstractThe morphologically and functionally distinct cell types of a multicellular organism are maintained by their unique epigenomes and gene expression programs. Phase III of the ENCODE Project profiled 66 mouse epigenomes across twelve tissues at daily intervals from embryonic day 11.5 to birth. Applying the ChromHMM algorithm to these epigenomes, we annotated eighteen chromatin states with characteristics of promoters, enhancers, transcribed regions, repressed regions, and quiescent regions. Our integrative analyses delineate the tissue specificity and developmental trajectory of the loci in these chromatin states. Approximately 0.3% of each epigenome is assigned to a bivalent chromatin state, which harbors both active marks and the repressive mark H3K27me3. Highly evolutionarily conserved, these loci are enriched in silencers bound by polycomb repressive complex proteins, and the transcription start sites of their silenced target genes. This collection of chromatin state assignments provides a useful resource for studying mammalian development.
Long-term transients help explain regime shifts in consumer-renewable resource systems
Authors: Eppinga Maarten B. , Siteur Koen , Baudena Mara , Reader Martin O. , van ’t Veen Hanneke , Anderies John M. , Santos Maria J. 
Published: February 2021

AbstractAs planetary boundaries loom, there is an urgent need to develop sustainable equilibriums between societies and the resources they consume, thereby avoiding regime shifts to undesired states. Transient system trajectories to a stable state may differ substantially, posing significant challenges to distinguishing sustainable from unsustainable trajectories. We use stylized models to show how feedbacks between anthropogenic harvest regimes and resource availability drive transient dynamics. We show how substantial time lags may occur between interventions and social-ecological outcomes, and that sudden system collapses need not be linked to recent environmental changes. Historical reconstructions of island state populations show a variety of transient dynamics that closely corresponds to model expectations based on island differences in productivity and harvesting regime. We conclude that vulnerable social-ecological systems may persist when the population:resource ratio remains within a viable range of intermediate (rather than small) values, which implies that averting environmental crises may require counter-intuitive measures.
Adiponectin inhibits lipoplysaccharide-induced inflammation and promotes osteogenesis in hPDLCs
Authors: Wu Huan-huan , Guo Yuan , Pu Yin-fei , Tang Zhi-hui 
Published: February 2021

Abstract
Periodontal diseases are infections of the structures that surround and support the teeth; they are characterized by local inflammation and alveolar bone loss. Most treatments focus on only one aspect, inhibiting inflammation, or promoting osteoblasts. We set out to develop a new method that would intervene in the two aspects simultaneously. Adiponectin (APN), secreted by adipocytes, inhibits the inflammatory response and promotes osteogenesis. However, its role in human periodontal ligament cells (hPDLCs) is unclear. Therefore, we aim to investigate whether APN could suppress lipopolysaccharide (LPS)-induced inflammation and promote osteogenesis in hPDLCs. In the present study, we stimulated hPDLCs with LPS in the presence or absence of APN. Real-time PCR and Western blotting results demonstrated that APN partially inhibited the activation of the classical nuclear factor κ-B (NF-κB) pathway. These results were confirmed by a change of expressions of NF-κB downstream inflammatory genes, such as decreased cyclooxygenase (COX)-2 and tumor necrosis factor α (TNF-α), along with increased interleukin (IL)-10. As for the role of APN in osteogenesis, Alizarin Red S staining showed that APN treatment induced more calcium deposition nodules than controls. We also found that APN enhanced the expression of osteoblast-related genes (osteopontin (OPN), collagen 1, osteocalcin, alkaline phosphatase, runt-related transcription factor 2 (RUNX2), and bone morphogenetic protein 2) in hPDLCs via the APPL1 (the adaptor protein containing PH domain, PTB domain, and leucine zipper motif 1)/p38 signal transduction pathway. Therefore, APN inhibits LPS-induced inflammation and promotes osteogenesis in hPDLCs and may have potential therapeutic value in treating periodontitis by inhibiting the inflammatory lesions and contributing to bone tissue regeneration.
A proposed efficiency metric for LTE‐advanced carrier aggregation
Authors: Ameen Araz Sabir 
Published: February 2021

AbstractLTE‐Advanced uses Carrier Aggregation (CA) and Spatial Multiplexing (SM) Multiple Input Multiple Output (MIMO) antenna system to achieve the target data rates of the 4G and 5G cellular system. Therefore, this paper studies the performance of the concurrent operation of the inter‐band CA and SM MIMO and proposes a novel CA efficiency metric that integrates the performance of different Component Carriers (CCs) into a single parameter. The proposed CA metric is then used to recommend a CA scenario that balances the transmit power of the CCs and results in efficient utilization of the antenna resources. The study is performed for many eNodeB‐UE links in an urban environment at CCs of 800 MHz and 2.6 GHz considering different combinations of single and multiple‐antenna systems. The radio channel is modelled using an urban site‐specific 3D ray‐tracing tool combined with measured antenna 3D radiation patterns. The simulation results show dependency on the number of aggregated spatial streams and cell radius. The paper recommends (1) the use of higher number of spatial streams for the lowest CC, (2) cell radius less than 600 m. The proposed CA efficiency metric can be used for system level simulation studies of any wireless technology that supports CA.
Novel failure mechanism of nanoscale mesa‐type avalanche photodiodes under harsh environmental stresses
Authors: Huang Jack Jia‐Sheng , Chang HsiangSzu , Chou Emin , Jan Yu‐Heng , Shi Jin‐Wei 
Published: February 2021

AbstractAvalanche photodiode (APD) is an indispensable receiver component because of its high bandwidth and low noise performance. Recently, APD reliability, under harsh environmental stresses such as high heat and humidity, has drawn great interest in the applications of passive optical network, wireless, military, and free space optics. The authors study the APD degradation under the harsh environment of high humidity and high bias. The failure morphology through cross‐sectional scanning electron microscopy is shown, and a new moisture degradation model based on electrochemical oxidation to account for the failure mechanism is developed.