104 research outputs found

    Strategi Valuation Model: Pengambilan Keputusan Investasi Pada Perusahaan Manufaktur Di Bursa Efek Indonesia

    Full text link
    This research was based upon Riahi-Belkaoui & Picur (2001) and Richard G Baker(1999) result which supposed there was relation between IOS with dividend and retained earningpolicy. Purpose of this research was to know empirically impact of valuation model strategy toinvestment decision making on manufacturing company. Using data of manufacturing companieswas listed during 2000-2005 in Indonesia Stock Exchange and analyzed with multiple regression.The results found were: 1). There was no effect between stock price with dividend on companiesand High IOS (Investment Opportunity Sets) although Low IOS. 2). There was significantlypositive effect between stock price with retained earning on companies and High IOS (InvestmentOpportunity Sets)

    Competitive Mechanochemical Solvate Formation of Theophylline in the Presence of Miscible Liquid Mixtures

    Get PDF
    In this study, we investigated the mechanochemical competitive solvate formation of polymorphic Form II of theophylline in the presence of two solvate/hydrate-forming miscible liquids, namely, water and 2-pyrrolidone. It is known that theophylline transforms into a monohydrate in the presence of water, while 2-pyrrolidone gives a monosolvate or a sesquisolvate, depending on the experimental conditions. Different theophylline-to-liquid molar ratios and several water:2-pyrrolidone mixtures were used to understand the competitive formation and/or transformation between these solvates. Interconversion studies between hydrate/monosolvate/sesquisolvate forms were also conducted. The obtained results suggest that water:2-pyrrolidone mixtures have a detrimental effect on the formation of multicomponent phases, as they dramatically reduce the efficiency of incorporation of both liquids in the crystal. In fact, all milling experiments performed in the presence of water:2-pyrrolidone mixtures suggested that a higher stoichiometric ratio is needed to obtain a pure form of a specific solvate. Importantly, additional competitive milling experiments revealed a preferential inclusion of 2-pyrrolidone over water. Based on several experimental datasets performed, we conclude that the propensity of solvate formation in the presence of liquid mixtures is a consequence of a complex interplaying of physicochemical and kinetic factors

    Mechanochemical reactivity inhibited, prohibited and reversed by liquid additives: examples from crystal-form screens

    Get PDF
    We demonstrate that liquid additives can exert inhibitive or prohibitive effects on the mechanochemical formation of multi-component molecular crystals, and report that certain additives unexpectedly prompt the dismantling of such solids into physical mixtures of their constituents. Computational methods were employed in an attempt to identify possible reasons for these previously unrecognised effects of liquid additives on mechanochemical transformations

    Modulating Thermal Properties of Polymers through Crystal Engineering

    Get PDF
    Crystal engineering has exclusively focused on the development of advanced materials based on small organic molecules. We now demonstrate how the cocrystallization of a polymer yields a material with significantly enhanced thermal stability but equivalent mechanical flexibility. Isomorphous replacement of one of the cocrystal components enables the formation of solid solutions with melting points that can be readily fine-tuned over a usefully wide temperature range. The results of this study credibly extend the scope of crystal engineering and cocrystallization from small molecules to polymers

    Drug Nanocrystals: Theoretical Background of Solubility Increase and Dissolution Rate Enhancement

    Get PDF
    The peculiar higher solubility of drug nanocrystals compared to macrocrystals appeals to the pharmaceutical field. Indeed, until now, about 70 % of the potential drug candidates are discarded due to low bioavailability related with poor solubility in water. Since a modern and efficient design strategy for nanocrystal-based delivery systems requires the knowledge of the theoretical relation between nanocrystal size and solubility, the aim of this paper is to build up a physically-oriented thermodynamic model relating to nanocrystal dimensions with their melting temperature, enthalpy, solubility and dissolution rate. In particular, the developed model will be applied to vinpocetine, a poorly soluble drug used in the treatment of various types of cerebrovascular circulatory disorders

    Drug Nanocrystals: Theoretical Background of Solubility Increase and Dissolution Rate Enhancement

    Get PDF
    The peculiar higher solubility of drug nanocrystals compared to macrocrystals appeals to the pharmaceutical field. Indeed, until now, about 70 % of the potential drug candidates are discarded due to low bioavailability related with poor solubility in water. Since a modern and efficient design strategy for nanocrystal-based delivery systems requires the knowledge of the theoretical relation between nanocrystal size and solubility, the aim of this paper is to build up a physically-oriented thermodynamic model relating to nanocrystal dimensions with their melting temperature, enthalpy, solubility and dissolution rate. In particular, the developed model will be applied to vinpocetine, a poorly soluble drug used in the treatment of various types of cerebrovascular circulatory disorders

    Selective Synthesis of a Salt and a Cocrystal of the Ethionamide-Salicylic Acid System

    Get PDF
    Herein is presented a rare example of salt/cocrystal polymorphism involving the adduct between ethionamide (ETH) and salicylic acid (SAL). Both the salt and cocrystal forms have the same stoichiometry and composition and are both stable at room temperature. The synthetic procedure was successfully optimized in order to selectively obtain both polymorphs. The two adducts' structures were thoroughly investigated by means of single-crystal X-ray diffraction, solid-state NMR spectroscopy, and density functional theory (DFT) calculations. From the solid-state NMR point of view, the combination of mono- and multinuclear experiments (1H MAS, 13C and 15N CPMAS, 1H-{14N} D-HMQC, 1H-14N PM-S-RESPDOR) provided undoubted spectroscopic evidence about the different positions of the hydrogen atom along the main N\ub7\ub7\ub7H\ub7\ub7\ub7O interaction. In particular, the 1H-14N PM-S-RESPDOR allowed N-H distance measurements through the 1H detected signal at a very high spinning speed (70 kHz), which remarkably agree with those derived by DFT optimized X-ray diffraction, even on a natural abundance real system. The thermodynamic relationship between the salt and the cocrystal was inquired from the experimental and computational points of view, enabling the characterization of the two polymorphs as enantiotropically related. The performances of the two forms in terms of dissolution rate are comparable to each other but significantly higher with respect to the pure ETH

    Germline-encoded neutralization of a Staphylococcus aureus virulence factor by the human antibody repertoire.

    Get PDF
    Staphylococcus aureus is both an important pathogen and a human commensal. To explore this ambivalent relationship between host and microbe, we analysed the memory humoral response against IsdB, a protein involved in iron acquisition, in four healthy donors. Here we show that in all donors a heavily biased use of two immunoglobulin heavy chain germlines generated high affinity (pM) antibodies that neutralize the two IsdB NEAT domains, IGHV4-39 for NEAT1 and IGHV1-69 for NEAT2. In contrast to the typical antibody/antigen interactions, the binding is primarily driven by the germline-encoded hydrophobic CDRH-2 motifs of IGHV1-69 and IGHV4-39, with a binding mechanism nearly identical for each antibody derived from different donors. Our results suggest that IGHV1-69 and IGHV4-39, while part of the adaptive immune system, may have evolved under selection pressure to encode a binding motif innately capable of recognizing and neutralizing a structurally conserved protein domain involved in pathogen iron acquisition

    Praziquantel meets Niclosamide: a dual-drug antiparasitic cocrystal

    Get PDF
    In this paper we report a successful example of combining drugs through cocrystallization. Specifically, the novel solid is formed by two anthelminthic drugs, namely praziquantel (PZQ) and niclosamide (NCM) in a 1:3 molar ratio, and it can be obtained through a sustainable one-step mechanochemical process in the presence of micromolar amounts of methanol. The novel solid phase crystallizes in the monoclinic space group of P2(1)/c, showing one PZQ and three NCM molecules linked through homo- and heteromolecular hydrogen bonds in the asymmetric unit, as also attested by SSNMR and FT-IR results. A plate-like habitus is evident from scanning electron microscopy analysis with a melting point of 202.89 °C, which is intermediate to those of the parent compounds. The supramolecular interactions confer favorable properties to the cocrystal, preventing NCM transformation into the insoluble monohydrate both in the solid state and in aqueous solution. Remarkably, the PZQ - NCM cocrystal exhibits higher anthelmintic activity against in vitro S. mansoni models than corresponding physical mixture of the APIs. Finally, due to in vitro promising results, in vivo preliminary tests on mice were also performed through the administration of minicapsules size M
    corecore