635 research outputs found

    Imaging Electronic Correlations in Twisted Bilayer Graphene near the Magic Angle

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    Twisted bilayer graphene with a twist angle of around 1.1{\deg} features a pair of isolated flat electronic bands and forms a strongly correlated electronic platform. Here, we use scanning tunneling microscopy to probe local properties of highly tunable twisted bilayer graphene devices and show that the flat bands strongly deform when aligned with the Fermi level. At half filling of the bands, we observe the development of gaps originating from correlated insulating states. Near charge neutrality, we find a previously unidentified correlated regime featuring a substantially enhanced flat band splitting that we describe within a microscopic model predicting a strong tendency towards nematic ordering. Our results provide insights into symmetry breaking correlation effects and highlight the importance of electronic interactions for all filling factors in twisted bilayer graphene.Comment: Main text 9 pages, 4 figures; Supplementary Information 25 page

    Melatonin receptor 1 B polymorphisms associated with the risk of gestational diabetes mellitus

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    <p>Abstract</p> <p>Backgrounds</p> <p>Two SNPs in <it>melatonin receptor 1B </it>gene, <it>rs10830963 </it>and <it>rs1387153 </it>showed significant associations with fasting plasma glucose levels and the risk of Type 2 Diabetes Mellitus (T2DM) in previous studies. Since T2DM and gestational diabetes mellitus (GDM) share similar characteristics, we suspected that the two genetic polymorphisms in <it>MTNR1B </it>may be associated with GDM, and conducted association studies between the polymorphisms and the disease. Furthermore, we also examined genetic effects of the two polymorphisms with various diabetes-related phenotypes.</p> <p>Methods</p> <p>A total of 1,918 subjects (928 GDM patients and 990 controls) were used for the study. Two <it>MTNR1B </it>polymorphisms were genotyped using TaqMan assay. The allele distributions of SNPs were evaluated by <it>x</it><sup>2 </sup>models calculating odds ratios (ORs), 95% confidence intervals (CIs), and corresponding <it>P </it>values. Multiple regressions were used for association analyses of GDM-related traits. Finally, conditional analyses were also performed.</p> <p>Results</p> <p>We found significant associations between the two genetic variants and GDM, <it>rs10830963</it>, with a corrected <it>P </it>value of 0.0001, and <it>rs1387153</it>, with the corrected <it>P </it>value of 0.0008. In addition, we also found that the two SNPs were associated with various phenotypes such as homeostasis model assessment of beta-cell function and fasting glucose levels. Further conditional analyses results suggested that <it>rs10830963 </it>might be more likely functional in case/control analysis, although not clear in GDM-related phenotype analyses.</p> <p>Conclusion</p> <p>There have been studies that found associations between genetic variants of other genes and GDM, this is the first study that found significant associations between SNPs of <it>MTNR1B </it>and GDM. The genetic effects of two SNPs identified in this study would be helpful in understanding the insight of GDM and other diabetes-related disorders.</p

    Shallow water marine sediment bacterial community shifts along a natural CO2 gradient in the Mediterranean Sea off Vulcano, Italy.

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    The effects of increasing atmospheric CO(2) on ocean ecosystems are a major environmental concern, as rapid shoaling of the carbonate saturation horizon is exposing vast areas of marine sediments to corrosive waters worldwide. Natural CO(2) gradients off Vulcano, Italy, have revealed profound ecosystem changes along rocky shore habitats as carbonate saturation levels decrease, but no investigations have yet been made of the sedimentary habitat. Here, we sampled the upper 2 cm of volcanic sand in three zones, ambient (median pCO(2) 419 μatm, minimum Ω(arag) 3.77), moderately CO(2)-enriched (median pCO(2) 592 μatm, minimum Ω(arag) 2.96), and highly CO(2)-enriched (median pCO(2) 1611 μatm, minimum Ω(arag) 0.35). We tested the hypothesis that increasing levels of seawater pCO(2) would cause significant shifts in sediment bacterial community composition, as shown recently in epilithic biofilms at the study site. In this study, 454 pyrosequencing of the V1 to V3 region of the 16S rRNA gene revealed a shift in community composition with increasing pCO(2). The relative abundances of most of the dominant genera were unaffected by the pCO(2) gradient, although there were significant differences for some 5 % of the genera present (viz. Georgenia, Lutibacter, Photobacterium, Acinetobacter, and Paenibacillus), and Shannon Diversity was greatest in sediments subject to long-term acidification (>100 years). Overall, this supports the view that globally increased ocean pCO(2) will be associated with changes in sediment bacterial community composition but that most of these organisms are resilient. However, further work is required to assess whether these results apply to other types of coastal sediments and whether the changes in relative abundance of bacterial taxa that we observed can significantly alter the biogeochemical functions of marine sediments

    Individual and partner risk factors associated with abnormal cervical cytology among women in HIV-discordant relationships

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    Individual and sexual partner characteristics may increase risk of abnormal cervical cytology among women in HIV-discordant relationships. Papanicolaou smears were obtained in a prospective cohort of Kenyan HIV-discordant couples. Of 441 women, 283 (64%) were HIV-infected and 158 (36%) were HIV-uninfected with HIV-infected partners. Overall, 79 (18%) had low-grade and 25 (6%) high-grade cervical abnormalities. Lack of male circumcision, male HSV-2 seropositivity and lower couple socioeconomic status were associated with cervical abnormalities (p350 cells/µL) had the lowest prevalence of high-grade cervical lesions. HIV-infected women (CD4>350 cells/µL) and HIV-uninfected women with HIV-infected partners (CD4≤350 cells/µL) were at similar intermediate risk (P>0.05), and HIV-infected women (CD4≤350 cells/µL) had significantly higher risk of high-grade cervical abnormalities (p=0.05). Women in HIV-discordant relationships have high rates of cervical lesions and this may be influenced by couple-level factors, including HIV status and CD4 count of the infected partner

    Local Scale-Dependent Non-Gaussian Curvature Perturbations at Cubic Order

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    We calculate non-Gaussianities in the bispectrum and trispectrum arising from the cubic term in the local expansion of the scalar curvature perturbation. We compute to three-loop order and for general momenta. A procedure for evaluating the leading behavior of the resulting loop-integrals is developed and discussed. Finally, we survey unique non-linear signals which could arise from the cubic term in the squeezed limit. In particular, it is shown that loop corrections can cause fNLsq.f_{NL}^{sq.} to change sign as the momentum scale is varied. There also exists a momentum limit where τNL<0\tau_{NL} <0 can be realized.Comment: Published in JCA

    Twenty Novel Disease Group-Specific and 12 New Shared Macrophage Pathways in Eight Groups of 34 Diseases Including 24 Inflammatory Organ Diseases and 10 Types of Tumors.

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    The mechanisms underlying pathophysiological regulation of tissue macrophage (Mφ) subsets remain poorly understood. From the expression of 207 Mφ genes comprising 31 markers for 10 subsets, 45 transcription factors (TFs), 56 immunometabolism enzymes, 23 trained immunity (innate immune memory) enzymes, and 52 other genes in microarray data, we made the following findings. (1) When 34 inflammation diseases and tumor types were grouped into eight categories, there was differential expression of the 31 Mφ markers and 45 Mφ TFs, highlighted by 12 shared and 20 group-specific disease pathways. (2) Mφ in lung, liver, spleen, and intestine (LLSI-Mφ) express higher M1 Mφ markers than lean adipose tissue Mφ (ATMφ) physiologically. (3) Pro-adipogenic TFs C/EBPα and PPARγ and proinflammatory adipokine leptin upregulate the expression of M1 Mφ markers. (4) Among 10 immune checkpoint receptors (ICRs), LLSI-Mφ and bone marrow (BM) Mφ express higher levels of CD274 (PDL-1) than ATMφ, presumably to counteract the M1 dominant status via its reverse signaling behavior. (5) Among 24 intercellular communication exosome mediators, LLSI- and BM- Mφ prefer to use RAB27A and STX3 than RAB31 and YKT6, suggesting new inflammatory exosome mediators for propagating inflammation. (6) Mφ in peritoneal tissue and LLSI-Mφ upregulate higher levels of immunometabolism enzymes than does ATMφ. (7) Mφ from peritoneum and LLSI-Mφ upregulate more trained immunity enzyme genes than does ATMφ. Our results suggest that multiple new mechanisms including the cell surface, intracellular immunometabolism, trained immunity, and TFs may be responsible for disease group-specific and shared pathways. Our findings have provided novel insights on the pathophysiological regulation of tissue Mφ, the disease group-specific and shared pathways of Mφ, and novel therapeutic targets for cancers and inflammations

    Dual Action of lysophosphatidate- functionalised titanium: Interactions with human (MG63) osteoblasts and methicillin resistant staphylococcus aureus

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    © 2015 Skindersoe et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Titanium (Ti) is a widely used material for surgical implants; total joint replacements (TJRs), screws and plates for fixing bones and dental implants are forged from Ti. Whilst Ti integrates well into host tissue approximately 10% of TJRs will fail in the lifetime of the patient through a process known as aseptic loosening. These failures necessitate revision arthroplasties which are more complicated and costly than the initial procedure. Finding ways of enhancing early (osseo)integration of TJRs is therefore highly desirable and continues to represent a research priority in current biomaterial design. One way of realising improvements in implant quality is to coat the Ti surface with small biological agents known to support human osteoblast formation and maturation at Ti surfaces. Lysophosphatidic acid (LPA) and certain LPA analogues offer potential solutions as Ti coatings in reducing aseptic loosening. Herein we present evidence for the successful bio-functionalisation of Ti using LPA. This modified Ti surface heightened the maturation of human osteoblasts, as supported by increased expression of alkaline phosphatase. These functionalised surfaces also deterred the attachment and growth of Staphylococcus aureus, a bacterium often associated with implant failures through sepsis. Collectively we provide evidence for the fabrication of a dual-action Ti surface finish, a highly desirable feature towards the development of next-generation implantable devices

    Diverse University Students Across the United States Reveal Promising Pathways to Hunter Recruitment and Retention

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    Declining participation in hunting, especially among young adult hunters, affects the ability of state and federal agencies to achieve goals for wildlife management and decreases revenue for conservation. For wildlife agencies hoping to engage diverse audiences in hunter recruitment, retention, and reactivation (R3) efforts, university settings provide unique advantages: they contain millions of young adults who are developmentally primed to explore new activities, and they cultivate a social atmosphere where new identities can flourish. From 2018 to 2020, we surveyed 17,203 undergraduate students at public universities across 22 states in the United States to explore R3 potential on college campuses and assess key demographic, social, and cognitive correlates of past and intended future hunting behavior. After weighting to account for demographic differences between our sample and the larger student population, 29% of students across all states had hunted in the past. Students with previous hunting experience were likely to be white, male, from rural areas or hunting families, and pursuing degrees related to natural resources. When we grouped students into 1 of 4 categories with respect to hunting (i.e., non-hunters [50%], potential hunters [22%], active hunters [26%], and lapsed hunters [3%]), comparisons revealed differences based on demographic attributes, beliefs, attitudes, and behaviors. Compared to active hunters, potential hunters were more likely to be females or racial and ethnic minorities, and less likely to experience social support for hunting. Potential hunters valued game meat and altruistic reasons for hunting, but they faced unique constraints due to lack of hunting knowledge and skills. Findings provide insights for marketing and programming designed to achieve R3 objectives with a focus on university students. © 2021 The Wildlife Society

    Integrated mutation, copy number and expression profiling in resectable non-small cell lung cancer

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to identify critical genes involved in non-small cell lung cancer (NSCLC) pathogenesis that may lead to a more complete understanding of this disease and identify novel molecular targets for use in the development of more effective therapies.</p> <p>Methods</p> <p>Both transcriptional and genomic profiling were performed on 69 resected NSCLC specimens and results correlated with mutational analyses and clinical data to identify genetic alterations associated with groups of interest.</p> <p>Results</p> <p>Combined analyses identified specific patterns of genetic alteration associated with adenocarcinoma vs. squamous differentiation; <it>KRAS </it>mutation; <it>TP53 </it>mutation, metastatic potential and disease recurrence and survival. Amplification of 3q was associated with mutations in <it>TP53 </it>in adenocarcinoma. A prognostic signature for disease recurrence, reflecting <it>KRAS </it>pathway activation, was validated in an independent test set.</p> <p>Conclusions</p> <p>These results may provide the first steps in identifying new predictive biomarkers and targets for novel therapies, thus improving outcomes for patients with this deadly disease.</p
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