414 research outputs found
Crystal engineering of pharmaceutical co-crystals from polymorphic active pharmaceutical ingredients
Innovation in crystal engineering
Journal ArticleThe first CrystEngComm discussion meeting on crystal engineering has demonstrated that the field has reached maturity in some areas (for example: design strategies, characterization of solid compounds, topological analysis of weak and strong non-covalent interactions), while the quest for novel properties engineered at molecular and supramolecular levels has only recently begun and the need for further research efforts is strongly felt. This Highlight article aims to provide a forward look and a constructive discussion of the prospects for future developments of crystal engineering as a bridge between supramolecular and molecular materials chemistry
Supramolecular metathesis: co-former exchange in co-crystals of pyrazine with (R, R)-,(S, S)-,(R, S)-and (S, S/R, R)-tartaric acid
Co-crystals of dextro-(R,R), levo-(S,S), meso-(R,S) and racemic (R,R–S,S)-tartaric acid with pyrazine were obtained by manual kneading and slurry experiments; subsequent reactions in the solid state between these co-crystals and the various forms of tartaric acid in the solid state and via slurry show that co-former exchange takes place according to the sequence of stability [(R,S)-ta]2·py > (S,S/R,R)-ta·py > (R,R)-ta·py or (S,S)-ta·py
On Nina Bandelj and Frederick F. Wherry (2011): The Cultural Wealth of Nations
The authors of this volume investigate their posed questions about the cultural wealth of nations by relying on the traditions of Viviana A. Zelizer and Alejandro Portes, who had ‘visions of an economic sociology that enfolds culture and development into its core’ (p. x.). Cultural economic sociology seeks to analyze the effects that culture, cultural differences and cultural heritage can have on economies through using sociological methods and theories to dissect how (intentionally or unintentionally) cultural advantages/cultural wealth can contribute to economic growth and local development
Mechanochemical preparation of adducts (co-crystals and molecular salts) of 1, 4-diazabicyclo-2.2. 2-octane with aromatic polycarboxylic acids
Solid-state adducts (co-crystals and molecular salts) of 1,4-diazabicyclo-[2.2.2]-octane (DABCO) with aromatic polycarboxylic acids (isophthalic acid, isoH2, dinicotinic acid, dinH2 and dipicolinic acid, dipH2) were prepared in the solid state by grinding and kneading techniques, and fully characterized via X-ray diffraction. The polycarboxylic acids differ for the presence/absence and position of a nitrogen atom in the aromatic ring; the extent of proton transfer, from the carboxylic groups on the acids to the nitrogen atoms on DABCO, reflects the trend of solution acidity of the three polycarboxylic acids
NÃvel tecnológico e balanço econômico de produção de mamona para obtenção do biodiesel no estado do Ceará
In order to determine technological level and economic balance of castor seed prodution (Ricinus communis) in the State of Ceará, one of the main producers of oil seed of Northeast of Brazil, the present research was coducted to verify economic feasibility and technological level of castor seed production for obtaining biodiesel. The data were collected in Boa Viagem, Tauá and Pedra Branca municipalities. For profit analysis, income and production cost per hectare of castor seed production in selected municipalities were considered. It was observed that on the average, 12,91% of the interviewed farmers are using more than 80% of the recommended techniques. The castor seed production in all the three selected municipalities is economically feasifble (profitable), without considering the cost related to family labor.Castor seed, Technological level, Biodiesel, Economic feasibility, Ceará, Research and Development/Tech Change/Emerging Technologies,
Too much water? Not enough? In situ monitoring of the mechanochemical reaction of copper salts with dicyandiamide
In situ monitoring of mechanochemical reactions between dicyandiamide (DCD) and CuX2 salts (X = Cl-, NO3-), for the preparation of compounds of agrochemical interest, showed the appearance of a number of phases. It is demonstrated that milling conditions, such as the amount of water added in wet grinding and/or the milling frequency, may affect the course of the mechanochemical reactions, and drive the reaction towards the formation of different products. It has been possible to discover by in situ monitored experiments two novel crystalline forms, namely the neutral complexes [Cu(DCD)(2)(OH2)(2)(NO3)(2)] (2) and [Cu(DCD)(2)(OH2)Cl-2]center dot H2O (4), in addition to the previously known molecular salt [Cu(DCD)(2)(OH2)(2)] [NO3](2)center dot 2H(2)O (1, DIVWAG) and neutral complex [Cu(DCD)(2)(OH2)Cl-2] (3, AQCYCU), for which no synthesis conditions were available. Compounds 2 and 4 were fully characterized via a combination of solid-state techniques, including X-ray diffraction, Raman spectroscopy and TGA
BALANÇO ECONÔMICO DA PRODUÇÃO DE MAMONA E BALANÇO ENERGÉTICO DA OBTENÇÃO DE BIODIESEL NO ESTADO DO CEARÁ
Dada a necessidade de se conhecer melhor a viabilidade econômica e energética da mamona (Ricinus communis) para o Estado do Ceará, enquanto um dos maiores produtores de oleaginosas no Nordeste do Brasil, o presente trabalho foi desenvolvido com o objetivo de elaborar um balanço econômico e energético da produção de mamona para obtenção de biodiesel no Estado do Ceará. A pesquisa foi realizada nos Municípios de Boa Viagem, Tauá e Pedra Branca. Foram utilizados os dados primários recolhidos dos produtores em entrevistas diretas. Na análise da rentabilidade foram consideradas as receitas e os custos de produção por hectare nos municípios selecionados. Os principais resultados obtidos na pesquisa indicam que a produção de mamona cearense nos três municípios analisados mostrou-se rentável, tendo sido a utilização de mão-de-obra familiar um fator primordial para se ter o baixo custo de produção. Em relação ao balanço energético, constatou-se que foi positivo para os municípios analisados, assumindo o valor igual a 1,52 para amostra total.------------------------------------------------In oder to know the economic and energetic balance of castor seed (Ricinus communis) for the State of Ceará, one of the main producers of in Northeast of Brazil, the present study work has been developed aiming to elaborate economic and energetic balance of castor seed production for obtaining biodiesel. The primary data were collected in Boa Viagem, Tauá and Pedra Branca municipalities. For profit analysis, income and production cost per hectare of castor seed in selected municipalities were considered. It was observed that on the average, 12,91% of interviewed farmers are using more than 80% of the recommended techniques. The castor seed production in all the three selected municipalities is economically feasible, without considering the cost related to family labor. Energy production and consumption ratio of 1.52 indicates that the each unit of energy spent on producing castor and biodiesel generates 1.52 unit of energy.mamona, biodiesel, balanço energético, balanço econômico, castor seed, biodiesel, economic feasibility, energy balance, Crop Production/Industries,
Antimicrobial activity of supramolecular salts of gallium(III) and proflavine and the intriguing case of a trioxalate complex
The use of the gallium oxalate complex [Ga(ox)(3)](3-) as a building block in the formation of a drug-drug salt with the antimicrobial agent proflavine (PF) as its proflavinium cation (HPF+), namely [HPF](3)[Ga(ox)(3)]center dot 4H(2)O, is reported together with the preparation of the potassium salt K-3[Ga(ox)(3)] and the novel dimeric gallium(III) salt K-4[Ga-2(ox)(4)(mu-OH)(2)]center dot 2H(2)O. All compounds have been characterized by solid state methods, and their performance as antimicrobial agents has been evaluated by disk diffusion assay against the bacteria strains Pseudomonas aeruginosa ATCC27853, Staphylococcus aureus ATCC25923, and Escherichia coli ATCC25922. While the [HPF](3)[Ga(ox)(3)]center dot 4H(2)O drug-drug salt is effective against all three strains, the gallium oxalate salt K-3[Ga(ox)(3)] showed impressive selectivity towards P. aeruginosa, with little to no antimicrobial activity against the other two organisms. This work presents novel breakthroughs towards Ga based antimicrobial agents
Comparison of Antimicrobial and Antibiofilm Activity of Proflavine Co-crystallized with Silver, Copper, Zinc, and Gallium Salts
Here, we exploit our mechanochemical synthesis for co-crystallization of an organic antiseptic, proflavine, with metal-based antimicrobials (silver, copper, zinc, and gallium). Our previous studies have looked for general antimicrobial activity for the co-crystals: proflavine center dot AgNO3, proflavine center dot CuCl, ZnCl3[Proflavinium], [Proflavinium](2)[ZnCl4]center dot H2O, and [Proflavinium](3)[Ga(oxalate)(3)]center dot 4H(2)O. Here, we explore and compare more precisely the bacteriostatic (minimal inhibitory concentrations) and antibiofilm (prevention of cell attachment and propagation) activities of the co-crystals. For this, we choose three prominent "ESKAPE" bacterial pathogens of Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. The antimicrobial behavior of the co-crystals was compared to that of the separate components of the polycrystalline samples to ascertain whether the proflavine-metal complex association in the solid state provided effective antimicrobial performance. We were particularly interested to see if the co-crystals were effective in preventing bacteria from initiating and propagating the biofilm mode of growth, as this growth form provides high antimicrobial resistance properties. We found that for the planktonic lifestyle of growth of the three bacterial strains, different co-crystal formulations gave selectivity for best performance. For the biofilm state of growth, we see that the silver proflavine co-crystal has the best overall antibiofilm activity against all three organisms. However, other proflavine-metal co-crystals also show practical antimicrobial efficacy against E. coli and S. aureus. While not all proflavine-metal co-crystals demonstrated enhanced antimicrobial efficacy over their constituents alone, all possessed acceptable antimicrobial properties while trapped in the co-crystal form. We also demonstrate that the metal-proflavine crystals retain antimicrobial activity in storage. This work defines that co-crystallization of metal compounds and organic antimicrobials has a potential role in the quest for antimicrobials/antiseptics in the defense against bacteria in our antimicrobial resistance era
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