124 research outputs found

    Novel pharmaceutical salts of albendazole

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    Albendazole (ABZ) is a class II safe and effective antihelmintic drug in the benzimidazole group according to the BCS (Biopharmaceutics Classification System) with low solubility (9 mg L-1) and high permeability (logP 2.54). Novel salts and salt hydrates of ABZ are reported with benzene and p-toluene sulfonic acid (BSA, PTSA), as well as carboxylic acids such as oxalic acid (OA), maleic acid (MLE), l-tartaric acid (LTA), 2,6-dihydroxybenzoic acid (2,6-DHBA), and 2,4,6-trihydroxybenzoic acid (2,4,6-THBA). The products ABZ-BSA, ABZ-BSA-H, ABZ-PTSA, ABZ-PTSA-H, ABZ-OA-H and ABZ-2,6-DHBA were confirmed by single crystal X-ray diffraction. In the hydrate structures (designated as -H), the water molecule acts as a bridge in the hydrogen bonding network. The salt formation of ABZ-MLE, ABZ-LTA, and ABZ-2,4,6-THBA was confirmed by 15N ss-NMR based on the chemical shift change of ca. 50 ppm. The sulfonate salt hydrates exhibit 2D isostructurality, and position disorder in the thiopropyl group in the drug crystal structure was not observed in the salts. Crystal lattice energies were calculated for the MLE, LTA, and 2,4,6-THBA complexes of ABZ to confirm the molecular salt formation. The cocrystals of ABZ with the hydroxybenzene carboxylic acids are novel salts in the benzimidazole drugs class

    SURMOF induced polymorphism and crystal morphological engineering of acetaminophen polymorphs: advantage of heterogeneous nucleation

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    © 2018 The Royal Society of Chemistry. Self-assembled monolayers are extended to SURMOFs as template hetero surfaces using a basic HKUST-1 MOF. The concept of MOF induced polymorphism with morphological engineering adapted to crystal engineering has shown to have the advantage of heterogeneous nucleation. The substrates are used to study the nucleation and growth of acetaminophen, and have resulted in metastable polymorphs which are of a desirable form with block morphology

    Data privacy in knowledge discovery

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    This thesis addresses data privacy in various stages of extracting knowledge embedded in databases. Advances in computer networking and database technologies have enabled the collection and storage of vast quantities of data. Legal and ethical considerations might require measures to protect an individual's privacy in any use or release of the data. In this thesis, we address the problem of preserving privacy in the two following cases: (1) in distributed knowledge discovery; (2) in situations where the output of a data mining algorithm could itself breach privacy. We present results in two different models, namely secure multiparty computation (SMC) and differential privacy. The first part of the thesis presents privacy preserving protocols in the SMC model. Secure multiparty computation involves the collaborative computation of functions based on inputs from multiple parties. The privacy goal is to ensure that all parties receive only the final output without any party learning anything beyond what can be inferred from the output. Within this framework we address the problem of preserving privacy in the preprocessing and the data mining stages of knowledge discovery in databases. For the preprocessing stage, we present private protocols for the imputation of missing data in a dataset that is shared between two parties. For the data mining stage, we introduce the notion of arbitrarily partitioned data that generalizes both horizontally and vertically partitioned data. We present a privacy-preserving protocol for k-means clustering of arbitrarily partitioned data. We also develop a new simple k-clustering algorithm that was designed to be converted into a communication-efficient protocol for private clustering. The second part of the thesis deals with privacy in situations where the output of a data mining algorithm could itself breach privacy. In this setting, we present private inference control protocols in the SMC model for On-line Analytical Processing systems. In the differential privacymodel, the goal is to provide access to a statistical database while preserving the privacy of every individual in the database, irrespective of any auxiliary information that may be available to the database client. Under this privacy model, we present a practical privacy preserving decision tree classifier using random decision trees.Ph.D.Includes abstractVitaIncludes bibliographical referencesby Geetha Jagannatha

    A dangerous but powerful idea - counter acceleration and speed with slowness and wholeness

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    The dangerous idea is that school reform, in India in particular, but across the world too, is impossible. Changing education, at the systemic level or at the institutional or school level, or educating teachers and school leaders in change can be classified as largely first order change - that of school improvement, which involves doing more of the same but doing it better (where the focus is on efficiency) and that of school re-structuring, which involves re-organising components and responsibilities (where the focus is on effectiveness). Geetha Narayanan is Principal Investigator with Project Vision at the Centre for Education Research Training and Development (CERTAD) within the Srishti School of Art Design and Technology in Bangalore, India. She has dedicated her career to finding and establishing new models of education that are creative, synergistic and original in their approach to learning. Read the article and listen to audio of the author discussing her ideas

    Tetranchyroderma hystrix Remane 1926

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    Tetranchyroderma hystrix Remane, 1926 Records from India. KERALA: Neendakara—Rajan & Nair (1979). Habitat. It has been recorded in well sorted sand with grain size ranging mostly from 295 to 592 µm Remarks. This species has been recorded by Rajan & Nair (1979) from Kerala in their ecological work, along with other gastrotrichs species and meiofauna. There is no drawing and other taxonomic data of this species provided by them or any other author from India. Consequently, we consider this species finding as a doubtful record that require more evidence to prove the presence of this species on the Indian coast.Published as part of Chatterjee, Tapas, Priyalakshmi, Geetha & Todaro, M. Antonio, 2019, An annotated checklist of the macrodasyidan Gastrotricha from India, pp. 495-510 in Zootaxa 4545 (4) on page 503, DOI: 10.11646/zootaxa.4545.4.3, http://zenodo.org/record/261830

    Binary and ternary cocrystals of sulfa drug acetazolamide with pyridine carboxamides and cyclic amides

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    A novel design strategy for cocrystals of a sulfonamide drug with pyridine carboxamides and cyclic amides is developed based on synthon identification as well as size and shape match of coformers. Binary adducts of acetazolamide (ACZ) with lactams (valerolactam and caprolactam, VLM, CPR), cyclic amides (2-pyridone, labeled as 2HP and its derivatives MeHP, OMeHP) and pyridine amides (nicotinamide and picolinamide, NAM, PAM) were obtained by manual grinding, and their single crystals by solution crystallization. The heterosynthons in the binary cocrystals of ACZ with these coformers suggested a ternary combination for ACZ with pyridone and nicotinamide. Novel supramolecular synthons of ACZ with lactams and pyridine carboxamides are reported together with binary and ternary cocrystals for a sulfonamide drug. This crystal engineering study resulted in the first ternary cocrystal of acetazolamide with amide coformers, ACZ–NAM–2HP (1:1:1)
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