1,153 research outputs found

    Cp2ZrCl2: AN EFFICIENT CATALYST FOR MULTICOMPONENT SYNTHESIS OF CAROTENOID DEHYDROSQUALENE SYNTHASE INHIBITING PYRANO[2,3-d]PYRIMIDINEDIONES

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    Objectives: The present protocol deals with zirconocene dichloride (Cp2ZrCl2) catalyzed synthesis of pyrano[2,3-d]pyrimidinediones through one-pot multicomponent reactions of aromatic aldehydes with malononitrile and barbituric acid at ambient temperature. All the synthesized compounds were characterized and evaluated for antibacterial, antifungal, and antioxidant activities. Furthermore, a molecular docking was carried out to reveal the atomic insights between synthesized compounds and carotenoid dehydrosqualene synthase (PDB ID: 3ACX). Methods: All the synthesized compounds were evaluated for their in vitro antimicrobial activity by diffusion method. Antioxidant activities such as 1,1-diphenyl-2-picrylhydrazyl and radical scavenging activity. A mixture of barbituric acid 1 (1 mmol), malononitrile 2 (1 mmol), benzaldehyde 3a (1 mmol), ethanol (5 mL), and Cp2ZrCl2 (5 mol %) was stirred at ambient temperature for specified time. After completion of reaction as indicated by thin-layer chromatography, the obtained crude product was filtered and purified by column chromatography on silica gel (Merck, 60–120 mesh) using ethyl acetate:pet. ether to afford pure product which was then characterized by spectroscopic methods such by FTIR, nuclear magnetic resonance (1H NMR), 13C NMR, and mass spectroscopy. Results: All the synthesized pyrano[2,3-d]pyrimidinediones were characterized by spectroscopic analysis. The results revealed that pyrano[2,3-d] pyrimidinediones (4 a-k) displayed the zone of inhibition in the range of 3–13 mm. The most active compound 4b displayed largest zone of inhibition of 13 mm for Escherichia coli (NCIM-2832) and 9 mm for Bacillus subtilis (NCIM-2635). The antifungal and antioxidant activity of all synthesized pyrano[2,3-d]pyrimidinediones (4a-k) showed moderate to good activity. Molecular docking studies suggest that pyrano[2,3-d]pyrimidinediones might inhibit the carotenoid dehydrosqualene synthase activity. Conclusion: All the synthesized pyrano[2,3-d]pyrimidinediones display moderate to good antibacterial, antifungal, and antioxidant activity. This molecular docking studies supported that pyrano[2,3-d]pyrimidinediones might inhibit the carotenoid dehydrosqualene synthase (PDB ID: 3ACX)

    Effect of Nanofluids on Heat Pipe Thermal Performance: A Review of the Recent Literature

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    Normally conventional fluids are used in heat pipes to remove the heat based on a temperature range for its particular operating conditions [1] (see Fig.2). The addition of the nano particles to the base fluid is one of the significant issues to enhance the heat transfer of heat pipes. The purpose of this review is to summarize the research done on heat pipes using nanofluids as working fluids in recent years (2012 to 2013). This review article provides additional information for the design of heat pipes with optimum conditions regarding the heat transfer characteristics of nanofluids in heat pipes. Moreover, this paper identifies several important issues that should be considered further in future works

    An Intrusion Detection System Algorithm for Defending MANET against the DDoS Attacks.

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    Mobile ad hoc network (MANET) is rapidly deployable, self configuring network able to communicate with each other without the aid of any centralized system. There is no need for existing infrastructure base network. In MANET Wireless medium is radio frequencies and nodes are mobile, topology can be very dynamically. Nodes must be able to relay traffic since communicating nodes might be out of range. A MANET can be a standalone network or it can be connected to external networks like internet. Multihop operation of MANET requires a routing mechanism designed for mobile nodes are internet access mechanisms, self configuring networks requires an address allocation mechanism, mechanism to detect and act on, merging of existing networks and security mechanisms. As we know that there is no any centralized system so routing is done by node itself. Due to its mobility and self routing capability nature, there are many weaknesses in its security

    Attribute Based Secure Data Retrieval System for Decentralized Disruption Tolerant Military Networks

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    There are partitions in military environments such as a battlefield or a hostile region.They are likely to suffer from intermittent network connectivity.They having frequent partitions. Disruption-tolerant network DTN technologies are is a true and easy solutions.DTN is a Disruption-tolerant network.It allow devices which are wireless and carried by peoples in a military to interact with each other.These devices access the confidential information or command reliably by exploiting external storage nodes. In these networking environments DTN is very successful technology. When there is no wired connection between a source and a destination device, the information from the source node may need to wait in the intermediate nodes for a large amount of time until the connection would be correctly established.one of the challenching approach is a ABE.that is attribute-based encryption which fulfills the requirements for secure data retrieval in DTNs. The another concept is Cipher text Policy ABE (CP-ABE).it gives a appropriate way of encryption of data. the encryption includes the attribute set that the decryption needs to possess in order to decrypt the cipher text.hence, Many users can be allowed to decrypt different parts of data according to the security policy

    Effect of different shading intensities on growth and yield of cherry tomato

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    Cherry tomato (Solanum lycopersicon var cerasiforme) is small size fruits, with a bright red colour resembling to cherry and becoming popular in the retail chains which are marketed at a premium price. The field experiment was conducted to study the effect of different (35, 50 and 75 per cent) shading intensities on growth and yield (qha-1 ) of cherry tomato. Significantly maximum yield was recorded in 35 per cent shading intensity and genotype Kalash Seeds Product (KSP)-113 (579.44 and 503.88 q ha-1 , respectively). Among the different shading intensities and genotypes, maximum plant height was observed in 75 per cent shading intensity and genotype KSP -113 at 30 days interval (74.70 and 60.95 cm, respectively). The minimum days to 50% flowering of cherry tomato were observed in cherry tomatoes grown under 35 per cent shading intensity (45.00 days) as compared to other shading intensities while minimum days to 50% flowering were observed in genotype KSP-113 (44.00 days). The maximum length of the cluster (9.58 cm), the weight of cluster (27.67 g), number of fruits per cluster (9.42) and number of pickings (11.67) were observed in 35 per cent shading intensities and in genotype KSP-113. The cultivation of KSP-113 genotype under 35 per cent shading intensity was found to be most sustainable for improving growth and yield of cherry tomato during the summer season

    User Feedback Analysis System using Natural Language Processing and Artificial Intelligence

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    The Web has dramatically changed the way that people express their views and opinions. Now if one wants to purchase a product, he/she is no longer limited to asking his/her friends and families because there are many product reviews on the Web which give opinions of existing users of the product. Here we present the system which provides us information about such products and services in summarization form. Finding opinion sources and monitoring them on the Web can still be a difficult task because there are a large number of diffrent sources, and each source may also have a huge volume of opinionated text (text with opinions or sentiments). In most cases, opinions are hidden in long forum posts and blogs. It is complicated for a human reader to find relable sources, extract related sentences with opinions, read them, summarize them, and manage them into usable forms. Thus, automated summarization systems are needed. Using this summarization we can recognize the importance, quality, popularity of product and services. In this system we make summarization for product. But, we can use this system anywhere, where text analysis is required. Sentiment analysis, also known as opinion mining, grows out of this need. It is a challenging natural language processing or text mining problem. Due to its tremendous value for practical applications, there has been an excessive growth of both research in academia and applications in the industry

    Probing the Outer Mouth Structure of the hERG Channel with Peptide Toxin Footprinting and Molecular Modeling

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    Abstract Previous studies have shown that the unusually long S5-P linker lining human ether a-go-go related gene’s (hERG’s) outer vestibule is critical for its channel function: point mutations at high-impact positions here can interfere with the inactivation process and, in many cases, also reduce the pore’s K+ selectivity. Because no data are available on the equivalent region in the available K channel crystal structures to allow for homology modeling, we used alternative approaches to model its three-dimensional structure. The first part of this article describes mutant cycle analysis used to identify residues on hERG’s outer vestibule that interact with specific residues on the interaction surface of BeKm-1, a peptide toxin with known NMR structure and a high binding affinity to hERG. The second part describes molecular modeling of hERG’s pore domain. The transmembrane region was modeled after the crystal structure of KvAP pore domain. The S5-P linker was docked to the transmembrane region based on data from previous NMR and mutagenesis experiments, as well as a set of modeling criteria. The models were further restrained by contact points between hERG’s outer vestibule and the bound BeKm-1 toxin molecule deduced from the mutant cycle analysis. Based on these analyses, we propose a working model for the open conformation of the outer vestibule of the hERG channel, in which the S5-P linkers interact with the pore loops to influence ion flux through the pore

    Dynamic Phase Transition from Localized to Spatiotemporal Chaos in Coupled Circle Map with Feedback

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    We investigate coupled circle maps in presence of feedback and explore various dynamical phases observed in this system of coupled high dimensional maps. We observe an interesting transition from localized chaos to spatiotemporal chaos. We study this transition as a dynamic phase transition. We observe that persistence acts as an excellent quantifier to describe this transition. Taking the location of the fixed point of circle map (which does not change with feedback) as a reference point, we compute number of sites which have been greater than (less than) the fixed point till time t. Though local dynamics is high-dimensional in this case this definition of persistence which tracks a single variable is an excellent quantifier for this transition. In most cases, we also obtain a well defined persistence exponent at the critical point and observe conventional scaling as seen in second order phase transitions. This indicates that persistence could work as good order parameter for transitions from fully or partially arrested phase. We also give an explanation of gaps in eigenvalue spectrum of the Jacobian of localized state

    Effect of Tephrosia purpurea roots extracts on acetic acid induced colitis in mice

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    Tephrosia purpurea L. (Leguminosae), commonly known as Unhali in Marathi is a copiously branched perennial herb. Traditionally the roots of this plant are used in the treatment of ulcer and colic pain. So the present work was undertaken to validate its use in the treatment of ulcerative colitis by using suitable scientific methods. Shade dried and coarsely powdered roots were subjected to successive extraction with ethanol and water. The dried extracts (100 and 200 mg/kg) were screened for ulcerative colitis using the method acetic acid induced ulcerative colitis in mice. Macroscopical study of the colon, level of myeloperoxidase in colon and histopathology of the colon tissue were studied for the assessment of the activity. Results showed that aqueous extract was significantly effective in the treatment of ulcerative colitis at dose of 200 mg/kg. It can be concluded that the polar constituents of T. purpurea L. may be useful in the treatment of ulcerative colitis.Colegio de Farmacéuticos de la Provincia de Buenos Aire
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