60 research outputs found

    Interior derivative estimates and Bernstein theorem for Hessian quotient equations

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    In this paper, we obtain the interior derivative estimates of solutions for elliptic and parabolic Hessian quotient equations. Then we establish the Bernstein theorem for parabolic Hessian quotient equations, that is, any parabolically convex solution u=u(x,t)C4,2(Rn×(,0])u=u(x,t)\in C^{4,2}(\mathbb{R}^n\times (-\infty,0]) for utSn(D2u)Sl(D2u)=1-u_t\frac{S_n(D^2u)}{S_l(D^2u)}=1 in Rn×(,0]\mathbb{R}^n\times (-\infty,0] must be the form of u=mt+P(x)u=-mt+P(x) with m>0m>0 being a constant and PP being a convex quadratic polynomial

    Dual-Band Quasi-Coherent Radiative Thermal Source

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    Thermal radiation from an unpatterned object is similar to that of a gray body. The thermal emission is insensitive to polarization, shows only Lambertian angular dependence, and is well modeled as the product of the blackbody distribution and a scalar emissivity over large frequency bands. Here, we design, fabricate and experimentally characterize the spectral, polarization, angular and temperature dependence of a microstructured SiC dual band thermal infrared source, achieving independent control of the frequency and polarization of thermal radiation in two spectral bands. The measured emission of the device in the Reststrahlen band (10.3-12.7 um) selectively approaches that of a blackbody, peaking at an emissivity of 0.85 at Lx=11.75 um and 0.81 at Ly=12.25 um. This effect arises due to the thermally excited phonon polaritons in silicon carbide. The control of thermal emission properties exhibited by the design is well suited for applications requiring infrared sources, gas or temperature sensors and nanoscale heat transfer. Our work paves the way for future silicon carbide based thermal metasurfaces.Comment: Journal of Quantitative Spectroscopy & Radiative Transfer (2018

    A single amino acid substitution in the R3 domain of GLABRA1 leads to inhibition of trichome formation in Arabidopsis without affecting its interaction with GLABRA3

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    GLABRA1 (GL1) is an R2R3 MYB transcription factor that regulates trichome formation in Arabidopsis by interacting with the bHLH transcription factor GLABRA3 (GL3) or ENHANCER OF GL3 (EGL3). The conserved [D/E]L×2 [R/K]×3L×6L×3R amino acid signature in the R3 domain of MYB proteins has been shown to be required for the interaction of MYBs with R/B‐like bHLH transcription factors. By using genetic and molecular analyses, we show that the glabrous phenotype in the nph4‐1 mutant is caused by a single nucleotide mutation in the GL1 gene, generating a Ser to Phe substitution (S92F) in the conserved [D/E]L×2[R/K]×3L×6L×3R amino acid signature of GL1. Activation of the integrated GL2p:GUS reporter gene in protoplasts by cotransfection of GL1 and GL3 or EGL3 was abolished by this GL1‐S92F substitution. However, GL1‐S92F interacted successfully with GL3 or EGL3 in protoplast transfection assays. Unlike VPGL1GL3, the fusion protein VPGL1‐S92FGL3 failed to activate the integrated GL2p:GUS reporter gene in transfected protoplasts. These results suggested that the S92 in the conserved [D/E]L×2 [R/K]×3L×6L×3R amino acid signature of GL1 is not essential for the interaction of GL1 and GL3, but may play a role in the binding of GL1 to the promoters of its target genes.The R2R3 MYB transcription factor GL1 is a key regulator of trichome formation in Arabidopsis. The conserved [D/E]L×2[R/K]×3L×6L×3R amino acid signature in the R3 domain is required for the interaction of MYBs with R/B‐like bHLH transcription factors. S92F amino acid substantiation in the conserved [D/E]L×2[R/K]×3L×6L×3R signature in GL1 lead to loss‐of‐function mutation of GL1. However, our results indicate that Ser92 residue is not required for the interaction of GL1 with bHLH transcription factor GL3 or EGL3, but may required for binding of GL1 to its target genes.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145310/1/pce12695_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145310/2/pce12695.pd

    Mining disease genes using integrated protein–protein interaction and gene–gene co-regulation information

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    AbstractIn humans, despite the rapid increase in disease-associated gene discovery, a large proportion of disease-associated genes are still unknown. Many network-based approaches have been used to prioritize disease genes. Many networks, such as the protein–protein interaction (PPI), KEGG, and gene co-expression networks, have been used. Expression quantitative trait loci (eQTLs) have been successfully applied for the determination of genes associated with several diseases. In this study, we constructed an eQTL-based gene–gene co-regulation network (GGCRN) and used it to mine for disease genes. We adopted the random walk with restart (RWR) algorithm to mine for genes associated with Alzheimer disease. Compared to the Human Protein Reference Database (HPRD) PPI network alone, the integrated HPRD PPI and GGCRN networks provided faster convergence and revealed new disease-related genes. Therefore, using the RWR algorithm for integrated PPI and GGCRN is an effective method for disease-associated gene mining

    A universal optical modulator for synthetic topologically tuneable structured matter

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    Topologically structured matter, such as metasurfaces and metamaterials, have given rise to impressive photonic functionality, fuelling diverse applications from microscopy and holography to encryption and communication. Presently these solutions are limited by their largely static nature and preset functionality, hindering applications that demand dynamic photonic systems with reconfigurable topologies. Here we demonstrate a universal optical modulator that implements topologically tuneable structured matter as virtual pixels derived from cascading low functionality tuneable devices, altering the paradigm of phase and amplitude control to encompass arbitrary spatially varying retarders in a synthetic structured matter device. Our approach opens unprecedented functionality that is user-defined with high flexibility, allowing our synthetic structured matter to act as an information carrier, beam generator, analyser, and corrector, opening an exciting path to tuneable topologies of light and matter

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    The Dirichlet problem for Hessian quotient equations in exterior domains

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    AbstractIn this paper, we obtain the uniqueness and existence of viscosity solutions with prescribed asymptotic behavior at infinity to Hessian quotient equations in exterior domains
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