118,183 research outputs found

    Super Natural II - a database of natural products

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    Natural products play a significant role in drug discovery and development. Many topological pharmacophore patterns are common between natural products and commercial drugs. A better understanding of the specific physicochemical and structural features of natural products is important for corresponding drug development. Several encyclopedias of natural compounds have been composed, but the information remains scattered or not freely available. The first version of the Supernatural database containing ∼50 000 compounds was published in 2006 to face these challenges. Here we present a new, updated and expanded version of natural product database, Super Natural II (http://bioinformatics.charite.de/supernatural), comprising ∼326 000 molecules. It provides all corresponding 2D structures, the most important structural and physicochemical properties, the predicted toxicity class for ∼170 000 compounds and the vendor information for the vast majority of compounds. The new version allows a template-based search for similar compounds as well as a search for compound names, vendors, specific physical properties or any substructures. Super Natural II also provides information about the pathways associated with synthesis and degradation of the natural products, as well as their mechanism of action with respect to structurally similar drugs and their target proteins

    Super natural II -a database of natural products

    Get PDF
    Natural products play a significant role in drug discovery and development. Many topological pharmacophore patterns are common between natural products and commercial drugs. A better understanding of the specific physicochemical and structural features of natural products is important for corresponding drug development. Several encyclopedias of natural compounds have been composed, but the information remains scattered or not freely available. The first version of the Supernatural database containing ∼ 50,000 compounds was published in 2006 to face these challenges. Here we present a new, updated and expanded version of natural product database, Super Natural II (http://bioinformatics.charite.de/supernatural), comprising ∼ 326,000 molecules. It provides all corresponding 2D structures, the most important structural and physicochemical properties, the predicted toxicity class for ∼ 170,000 compounds and the vendor information for the vast majority of compounds. The new version allows a template-based search for similar compounds as well as a search for compound names, vendors, specific physical properties or any substructures. Super Natural II also provides information about the pathways associated with synthesis and degradation of the natural products, as well as their mechanism of action with respect to structurally similar drugs and their target proteins

    Deep Markov Random Field for Image Modeling

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    Markov Random Fields (MRFs), a formulation widely used in generative image modeling, have long been plagued by the lack of expressive power. This issue is primarily due to the fact that conventional MRFs formulations tend to use simplistic factors to capture local patterns. In this paper, we move beyond such limitations, and propose a novel MRF model that uses fully-connected neurons to express the complex interactions among pixels. Through theoretical analysis, we reveal an inherent connection between this model and recurrent neural networks, and thereon derive an approximated feed-forward network that couples multiple RNNs along opposite directions. This formulation combines the expressive power of deep neural networks and the cyclic dependency structure of MRF in a unified model, bringing the modeling capability to a new level. The feed-forward approximation also allows it to be efficiently learned from data. Experimental results on a variety of low-level vision tasks show notable improvement over state-of-the-arts.Comment: Accepted at ECCV 201

    Deep learning approach to describe and classify fungi microscopic images

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    Preliminary diagnosis of fungal infections can rely on microscopic examination. However, in many cases, it does not allow unambiguous identification of the species by microbiologist due to their visual similarity. Therefore, it is usually necessary to use additional biochemical tests. That involves additional costs and extends the identification process up to 10 days. Such a delay in the implementation of targeted therapy may be grave in consequence as the mortality rate for immunosuppressed patients is high. In this paper, we apply a machine learning approach based on deep neural networks and Fisher Vector (advanced bag-of-words method) to classify microscopic images of various fungi species. Our approach has the potential to make the last stage of biochemical identification redundant, shortening the identification process by 2-3 days, and reducing the cost of the diagnosis

    Overlapping Free Trade Agreements of Singapore-USA-Japan: A Computational Analysis

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    The proliferation of overlapping free trade agreements (FTA) in the recent years has led to hub-and-spokes (HAS) throughout the world. Being avid subscribers to FTAs, many countries in the Asia-Pacific region including the USA, Japan, Singapore, South Korea, Thailand and Australia have become trade hubs to their partners who are in turn relegated to spoke status. In this paper, we question whether being a hub is welfare optimal for a small and open economy like Singapore compared to membership in a single bilateral FTA or a multi- member free trade zone. Within this context, we use a computable general equilibrium model to examine the welfare implications of the triangular trade relationship of the USA, Singapore and Japan. This is facilitated by the Japan- Singapore Economic Partnership Agreement, the USA-Singapore Free Trade Agreement, and a hypothetical USA-Japan Economic Partnership Agreement. The analysis is extended to incorporate “super-hub” effects; that is, the spoke countries can be trade hubs in other HAS systems. The experiment reveals that hub status generates positive welfare gain and is the highest Singapore can get from the trade configurations considered. Meanwhile, Japan loses more than the USA when both are relegated to spoke status. These findings prove robust under different market structures and production technologies, deeper economic integration, “super-hub” effects, as well as, uncertainty in the key model parameters and the extent of trade liberalisation shocks.hub and spokes; overlapping agreements; free trade; preference dilution; computable general equilibrium; GTAP; systems; trade configurations
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