525 research outputs found

    Deep-learning the Latent Space of Light Transport

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    We suggest a method to directly deep‐learn light transport, i. e., the mapping from a 3D geometry‐illumination‐material configuration to a shaded 2D image. While many previous learning methods have employed 2D convolutional neural networks applied to images, we show for the first time that light transport can be learned directly in 3D. The benefit of 3D over 2D is, that the former can also correctly capture illumination effects related to occluded and/or semi‐transparent geometry. To learn 3D light transport, we represent the 3D scene as an unstructured 3D point cloud, which is later, during rendering, projected to the 2D output image. Thus, we suggest a two‐stage operator comprising a 3D network that first transforms the point cloud into a latent representation, which is later on projected to the 2D output image using a dedicated 3D‐2D network in a second step. We will show that our approach results in improved quality in terms of temporal coherence while retaining most of the computational efficiency of common 2D methods. As a consequence, the proposed two stage‐operator serves as a valuable extension to modern deferred shading approaches

    Interactions Between Oxygen and Nitrogen: O[Single Bond]N, O[Single Bond]N (sub 2), and O (sub 2)[Single Bond]N (sub 2)

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    Potential energy curves for 0-N interactions corresponding to the X (sup 2) II (sub t/2), X (sup 2) II (sub 3/2), A (sup 2) Eta (sup plus), B (sup 2) II, C (sup 2) II, D (sup 2) Eta (sup plus), E (sup 2) Eta (sup plus), and B prime (sup 2 delta) states of nitric oxide have been calculated from spectroscopic data by the Rydberg- Klein-Rees method. Curves for the (sup 4) II, (sup 2) Eta, (sup 4) Eta, (sup 6) Eta, and (sup 6) II states have been obtained from limited spectroscopic results and from relations derived from approximate quantum-mechanical calculations. Two semi-independent calculations have been made, and are in good agreement with each other. The quantum-mechanical relations also lead to approximate curves for the O[Single Bond]N, and O[Single Bond]N (sub 2) interactions over a limited range. The O (sub 2)[Single Bond]N (sub 2) interaction is consistent with one valid at larger separation distances which has been derived from high-temperature gas viscosity data

    Designing the future: strategy, design and the 4th Revolution: an introduction

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    This is an introduction to the special issue of California Management Review on Design Thinking (DT). This special issue joins the growing body of work exploring the idea of DT and whether DT makes a difference in terms enhancing or augmenting the impact of technology—and, as a result, innovation—in a positive way. We have chosen an interesting, relevant, and useful array of papers that provide different approaches, views, and interpretations of applied design thinking. These articles provide both management and scholarly readers with insights in how DT is used, as well as its impact and usefulness in a variety of contexts

    Interactions between Ground State Oxygen Atoms and Molecules: O - O and O (sub2) - O (sub2)

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    Potential energy curves for O - O interactions corresponding to the X (sup 3) Sigma - g, 1 delta g, 1 Sigma plus g, 3 delta u, A3 Sigma plus u, 1 Sigma - u, and B3 Sigma states of O (sub 2) have been calculated from spectroscopic data by the RydbergKleinRees method. Curves for the remaining twelve states of O (sub 2) dissociating to ground state atoms have been obtained from relations derived from approximate quantummechanical calculations, and checked against the meager experimental information available. Two semiindependent calculations have been made, and are in good agreement with each other. The quantummechanical relations also lead to an approximate O (sub 2) - O (sub 2) interaction, which is consistent with interactions derived from vibrational relaxation times and from hightemperature gas viscosity data

    Pericardial effusion of HIV-infected patients - results of a prospective multicenter cohort study in the era of antiretroviral therapy

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    <p>Abstract</p> <p>Background</p> <p>Patients with human immunodeficiency virus (HIV) infection have an increased risk of cardiovascular diseases. Previous publications described pericardial effusion as one of the most common HlV-associated cardiac affiliations. The aim of the current study was to investigate if pericardial effusion still has a relevant meaning of HIV-infected patients in the era of antiretroviral therapy.</p> <p>Methods</p> <p>The HIV-HEART (HIV-infection and HEART disease) study is a cardiology driven, prospective and multicenter cohort study. Outpatients with a known HIV-infection were recruited during a 20 month period in a consecutive manner from September 2004 to May 2006. The study comprehends classic parameters of HIV-infection, comprising CD4-cell count (cluster of differentiation) and virus load, as well as non-invasive tests of cardiac diseases, including a thorough transthoracic echocardiography.</p> <p>Results</p> <p>802 HIV-infected patients (female: 16.6%) with a mean age of 44.2 Âą 10.3 years, were included. Duration of HIV-infection since initial diagnosis was 7.6 Âą 5.8 years. Of all participants, 85.2% received antiretroviral therapy. Virus load was detectable in 34.4% and CD4 - cell count was in 12.4% less than 200 cells/ÎźL. Pericardial effusions were present in only two patients of the analysed population. None of the participants had signs of a relevant cardiovascular impairment by pericardial effusion.</p> <p>Conclusions</p> <p>Our results demonstrate that the era of antiretroviral therapy goes along with low rates of pericardial effusions in HIV-infected outpatients. Our findings are in contrast to the results of publications, performed before the common use of antiretroviral therapy.</p

    Investigation of the HelioVital filter foil revealed protective effects against UVA1 irradiation-induced DNA damage and against UVA1-induced expression of matrixmetalloproteinases (MMP) MMP1, MMP2, MMP3 and MMP15

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    The damaging effects of solar ultraviolet (UV) radiation exposure to human skin are well known and can reach from accelerated skin aging (photoaging) to skin cancer. Much of the damaging effects of solar UVA (320–400 nm) radiation is associated with the induction of reactive oxygen species (ROS), which are capable to cause oxidative damage to DNA like the oxidized guanosine 8-hydroxy-2' -deoxyguanosine (8-OHdG). Therefore, new UV protective strategies, have to be tested for their efficiency to shield against UV induced damage. We investigated the protective effects of HelioVital sun protection filter foil against UVA1 irradiation in skin cells. It could be shown, that HelioVital sun protection filter foil has protective effects against UVA1 irradiation induced changes in matrix metalloproteinase (MMP) expression. Furthermore a UVA1-dependant regulation of MMP15 in human fibroblasts could be shown for the first time in this context. In addition, this study demonstrated the protective effect of the HelioVital filter film against UVA1-induced ROS production and DNA damage. These results could pave the way for clinical studies with HelioVital filter foil shielding against the damaging effects of phototherapy and other forms of irradiation therapy, thereby increasing the safety and treatment opportunities of these forms of therapy

    Efficient Photodynamic Therapy against Gram-Positive and Gram-Negative Bacteria Using THPTS, a Cationic Photosensitizer Excited by Infrared Wavelength

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    The worldwide rise in the rates of antibiotic resistance of bacteria underlines the need for alternative antibacterial agents. A promising approach to kill antibiotic-resistant bacteria uses light in combination with a photosensitizer to induce a phototoxic reaction. Concentrations of 1, 10 and 100µM of tetrahydroporphyrin-tetratosylat (THPTS) and different incubation times (30, 90 and 180min) were used to measure photodynamic efficiency against two Gram-positive strains of S.aureus (MSSA and MRSA), and two Gram-negative strains of E.coli and P.aeruginosa. We found that phototoxicity of the drug is independent of the antibiotic resistance pattern when incubated in PBS for the investigated strains. Also, an incubation with 100µM THPTS followed by illumination, yielded a 6lg (≥99.999%) decrease in the viable numbers of all bacteria strains tested, indicating that the THPTS drug has a high degree of photodynamic inactivation. We then modulated incubation time, photosensitizer concentration and monitored the effect of serum on the THPTS activity. In doing so, we established the conditions to obtain the strongest bactericidal effect. Our results suggest that this new and highly pure synthetic compound should improve the efficiency of photodynamic therapy against multiresistant bacteria and has a significant potential for clinical applications in the treatment of nosocomial infections

    UVA-induced metabolic changes in non-malignant skin cells and the potential role of pyruvate as antioxidant

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    The exposure to UVA (320–400 nm) irradiation is a major threat to human skin concerning photoaging and carcinogenesis. It has been shown that UVA irradiation can induce reactive oxygen species (ROS) and DNA mutations, such as 8-hydroxydeoxyguanosine. Furthermore, UVA induces the expression of photoaging-associated matrix metalloproteases (MMPs), especially of matrix metalloprotease 1 (MMP 1) and matrix metalloprotease 3 (MMP 3). In addition to this, it was recently shown that UVA-induced ROS also increase glucose metabolism of melanoma cells, however, the influence of UVA on the glucose metabolism of non-malignant cells of the human skin has, so far, not been investigated in detail. Here, we investigated the UVA-induced changes in glucose metabolism and the functional relevance of these changes in primary fibroblasts—normal non-malignant cells of the skin. These cells showed an UVA-induced enhanced glucose consumption and lactate production and changes in pyruvate production. As it has been proposed that pyruvate could have antioxidant properties we tested the functional relevance of pyruvate as protective agent against UVA-induced ROS. Our initial experiments support earlier publications, demonstrating that pyruvate treated with H2O2 is non-enzymatically transformed to acetate. Furthermore, we show that this decarboxylation of pyruvate to acetate also occurs upon UVA irradiation. In addition to this, we could show that in fibroblasts pyruvate has antioxidant properties as enhanced levels of pyruvate protect cells from UVA-induced ROS and partially from a DNA mutation by the modified base 8-hydroxydeoxyguanosine. Furthermore, we describe for the first time, that the interaction of UVA with pyruvate is relevant for the regulation of photoaging-associated MMP 1 and MMP 3 expression

    New ophthalmosaurid ichthyosaurs from the European lower cretaceous demonstrate extensive ichthyosaur survival across the Jurassic–Cretaceous boundary

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    Background Ichthyosauria is a diverse clade of marine amniotes that spanned most of the Mesozoic. Until recently, most authors interpreted the fossil record as showing that three major extinction events affected this group during its history: one during the latest Triassic, one at the Jurassic–Cretaceous boundary (JCB), and one (resulting in total extinction) at the Cenomanian-Turonian boundary. The JCB was believed to eradicate most of the peculiar morphotypes found in the Late Jurassic, in favor of apparently less specialized forms in the Cretaceous. However, the record of ichthyosaurs from the Berriasian–Barremian interval is extremely limited, and the effects of the end-Jurassic extinction event on ichthyosaurs remains poorly understood. Methodology/Principal Findings Based on new material from the Hauterivian of England and Germany and on abundant material from the Cambridge Greensand Formation, we name a new ophthalmosaurid, Acamptonectes densus gen. et sp. nov. This taxon shares numerous features with Ophthalmosaurus, a genus now restricted to the Callovian–Berriasian interval. Our phylogenetic analysis indicates that Ophthalmosauridae diverged early in its history into two markedly distinct clades, Ophthalmosaurinae and Platypterygiinae, both of which cross the JCB and persist to the late Albian at least. To evaluate the effect of the JCB extinction event on ichthyosaurs, we calculated cladogenesis, extinction, and survival rates for each stage of the Oxfordian–Barremian interval, under different scenarios. The extinction rate during the JCB never surpasses the background extinction rate for the Oxfordian–Barremian interval and the JCB records one of the highest survival rates of the interval. Conclusions/Significance There is currently no evidence that ichthyosaurs were affected by the JCB extinction event, in contrast to many other marine groups. Ophthalmosaurid ichthyosaurs remained diverse from their rapid radiation in the Middle Jurassic to their total extinction at the beginning of the Late Cretaceous

    Photoantimicrobials-are we afraid of the light?

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    Although conventional antimicrobial drugs have been viewed as miraculous cure-alls for the past 80 years, increasing antimicrobial drug resistance requires a major and rapid intervention. However, the development of novel but still conventional systemic antimicrobial agents, having only a single mode or site of action, will not alleviate the situation because it is probably only a matter of time until any such agents will also become ineffective. To continue to produce new agents based on this notion is unacceptable, and there is an increasing need for alternative approaches to the problem. By contrast, light-activated molecules called photoantimicrobials act locally via the in-situ production of highly reactive oxygen species, which simultaneously attack various biomolecular sites in the pathogenic target and therefore offer both multiple and variable sites of action. This non-specificity at the target circumvents conventional mechanisms of resistance and inhibits the development of resistance to the agents themselves. Photoantimicrobial therapy is safe and easy to implement and, unlike conventional agents, the activity spectrum of photoantimicrobials covers bacteria, fungi, viruses, and protozoa. However, clinical trials of these new, truly broad-spectrum, and minimally toxic agents have been few, and the funding for research and development is almost non-existent. Photoantimicrobials constitute one of the few ways forward through the morass of drug-resistant infectious disease and should be fully explored. In this Personal View, we raise awareness of the novel photoantimicrobial technologies that offer a viable alternative to conventional drugs in many relevant application fields, and could thus slow the pace of resistance development
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