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Sample records for combinational soluble n-ethylmaleimide-sensitive

  1. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors required during Trypanosoma cruzi parasitophorous vacuole development.

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    Cueto, Juan Agustín; Vanrell, María Cristina; Salassa, Betiana Nebaí; Nola, Sébastien; Galli, Thierry; Colombo, María Isabel; Romano, Patricia Silvia

    2017-06-01

    Trypanosoma cruzi, the etiologic agent of Chagas disease, is an obligate intracellular parasite that exploits different host vesicular pathways to invade the target cells. Vesicular and target soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are key proteins of the intracellular membrane fusion machinery. During the early times of T. cruzi infection, several vesicles are attracted to the parasite contact sites in the plasma membrane. Fusion of these vesicles promotes the formation of the parasitic vacuole and parasite entry. In this work, we study the requirement and the nature of SNAREs involved in the fusion events that take place during T. cruzi infection. Our results show that inhibition of N-ethylmaleimide-sensitive factor protein, a protein required for SNARE complex disassembly, impairs T. cruzi infection. Both TI-VAMP/VAMP7 and cellubrevin/VAMP3, two v-SNAREs of the endocytic and exocytic pathways, are specifically recruited to the parasitophorous vacuole membrane in a synchronized manner but, although VAMP3 is acquired earlier than VAMP7, impairment of VAMP3 by tetanus neurotoxin fails to reduce T. cruzi infection. In contrast, reduction of VAMP7 activity by expression of VAMP7's longin domain, depletion by small interfering RNA or knockout, significantly decreases T. cruzi infection susceptibility as a result of a minor acquisition of lysosomal components to the parasitic vacuole. In addition, overexpression of the VAMP7 partner Vti1b increases the infection, whereas expression of a KIF5 kinesin mutant reduces VAMP7 recruitment to vacuole and, concomitantly, T. cruzi infection. Altogether, these data support a key role of TI-VAMP/VAMP7 in the fusion events that culminate in the T. cruzi parasitophorous vacuole development. © 2016 John Wiley & Sons Ltd.

  2. The Central Polybasic Region of the Soluble SNARE (Soluble N-Ethylmaleimide-sensitive Factor Attachment Protein Receptor) Vam7 Affects Binding to Phosphatidylinositol 3-Phosphate by the PX (Phox Homology) Domain.

    Science.gov (United States)

    Miner, Gregory E; Starr, Matthew L; Hurst, Logan R; Sparks, Robert P; Padolina, Mark; Fratti, Rutilio A

    2016-08-19

    The yeast vacuole requires four SNAREs to trigger membrane fusion including the soluble Qc-SNARE Vam7. The N-terminal PX domain of Vam7 binds to the lipid phosphatidylinositol 3-phosphate (PI3P) and the tethering complex HOPS (homotypic fusion and vacuole protein sorting complex), whereas the C-terminal SNARE motif forms SNARE complexes. Vam7 also contains an uncharacterized middle domain that is predicted to be a coiled-coil domain with multiple helices. One helix contains a polybasic region (PBR) composed of Arg-164, Arg-168, Lys-172, Lys-175, Arg-179, and Lys-186. Polybasic regions are often associated with nonspecific binding to acidic phospholipids including phosphoinositides. Although the PX (phox homology) domain alone binds PI3P, we theorized that the Vam7 PBR could bind to additional acidic phospholipids enriched at fusion sites. Mutating each of the basic residues in the PBR to an alanine (Vam7-6A) led to attenuated vacuole fusion. The defective fusion of Vam7-6A was due in part to inefficient association with its cognate SNAREs and HOPS, yet the overall vacuole association of Vam7-6A was similar to wild type. Experiments testing the binding of Vam7 to specific signaling lipids showed that mutating the PBR to alanines augmented binding to PI3P. The increased binding to PI3P by Vam7-6A likely contributed to the observed wild type levels of vacuole association, whereas protein-protein interactions were diminished. PI3P binding was inhibited when the PX domain mutant Y42A was introduced into Vam7-6A to make Vam7-7A. Thus the Vam7 PBR affects PI3P binding by the PX domain and in turn affects binding to SNAREs and HOPS to support efficient fusion. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. The N-ethylmaleimide-sensitive factor and dysbindin interact to modulate synaptic plasticity.

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    Gokhale, Avanti; Mullin, Ariana P; Zlatic, Stephanie A; Easley, Charles A; Merritt, Megan E; Raj, Nisha; Larimore, Jennifer; Gordon, David E; Peden, Andrew A; Sanyal, Subhabrata; Faundez, Victor

    2015-05-13

    Dysbindin is a schizophrenia susceptibility factor and subunit of the biogenesis of lysosome-related organelles complex 1 (BLOC-1) required for lysosome-related organelle biogenesis, and in neurons, synaptic vesicle assembly, neurotransmission, and plasticity. Protein networks, or interactomes, downstream of dysbindin/BLOC-1 remain partially explored despite their potential to illuminate neurodevelopmental disorder mechanisms. Here, we conducted a proteome-wide search for polypeptides whose cellular content is sensitive to dysbindin/BLOC-1 loss of function. We identified components of the vesicle fusion machinery as factors downregulated in dysbindin/BLOC-1 deficiency in neuroectodermal cells and iPSC-derived human neurons, among them the N-ethylmaleimide-sensitive factor (NSF). Human dysbindin/BLOC-1 coprecipitates with NSF and vice versa, and both proteins colocalized in a Drosophila model synapse. To test the hypothesis that NSF and dysbindin/BLOC-1 participate in a pathway-regulating synaptic function, we examined the role for NSF in dysbindin/BLOC-1-dependent synaptic homeostatic plasticity in Drosophila. As previously described, we found that mutations in dysbindin precluded homeostatic synaptic plasticity elicited by acute blockage of postsynaptic receptors. This dysbindin mutant phenotype is fully rescued by presynaptic expression of either dysbindin or Drosophila NSF. However, neither reduction of NSF alone or in combination with dysbindin haploinsufficiency impaired homeostatic synaptic plasticity. Our results demonstrate that dysbindin/BLOC-1 expression defects result in altered cellular content of proteins of the vesicle fusion apparatus and therefore influence synaptic plasticity. Copyright © 2015 the authors 0270-6474/15/357643-11$15.00/0.

  4. The role of the N-D1 linker of the N-ethylmaleimide-sensitive factor in the SNARE disassembly.

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    Cui-Cui Liu

    Full Text Available N-ethylmaleimide-sensitive factor (NSF is a member of the type II AAA+ (ATPase associated with various cellular activities family. It plays a critical role in intracellular membrane trafficking by disassembling soluble NSF attachment protein receptor (SNARE complexes. Each NSF protomer consists of an N-terminal domain (N domain followed by two AAA ATPase domains (D1 and D2 in tandem. The N domain is required for SNARE/α-SNAP binding and the D1 domain accounts for the majority of ATP hydrolysis. Little is known about the role of the N-D1 linker in the NSF function. This study presents detailed mutagenesis analyses of NSF N-D1 linker, dissecting its role in the SNARE disassembly, the SNARE/α-SNAP complex binding, the basal ATPase activity and the SNARE/α-SNAP stimulated ATPase activity. Our results show that the N-terminal region of the N-D1 linker associated mutants cause severe defect in SNARE complex disassembly, but little effects on the SNARE/α-SNAP complex binding, the basal and the SNARE/α-SNAP stimulated ATPase activity, suggesting this region may be involved in the motion transmission from D1 to N domain. Mutating the residues in middle and C-terminal region of the N-D1 linker increases the basal ATPase activity, indicating it may play a role in autoinhibiting NSF activity until it encounters SNARE/α-SNAP complex substrate. Moreover, mutations at the C-terminal sequence GIGG exhibit completely abolished or severely reduced activities of the substrate binding, suggesting that the flexibility of N-D1 linker is critical for the movement of the N domain that is required for the substrate binding. Taken together, these data suggest that the whole N-D1 linker is critical for the biological function of NSF to disassemble SNARE complex substrate with different regions responsible for different roles.

  5. N-Ethylmaleimide-Sensitive Factor b (nsfb) Is Required for Normal Pigmentation of the Zebrafish Retinal Pigment Epithelium.

    Science.gov (United States)

    Hanovice, Nicholas J; Daly, Christina M S; Gross, Jeffrey M

    2015-11-01

    Despite the number of albinism-causing mutations identified in human patients and animal models, there remain a significant number of cases for which no mutation has been identified, suggesting that our understanding of melanogenesis is incomplete. Previously, we identified two oculocutaneous albinism mutations in zebrafish, au13 and au18. Here, we sought to identify the mutated loci and determine how the affected proteins contribute to normal pigmentation of the retinal pigment epithelium (RPE). Complementation analyses revealed that au13 and au18 belonged to a single complementation group, suggesting that they affected the same locus. Whole-genome sequencing and single nucleotide polymorphism (SNP) analysis was performed to identify putative mutations, which were confirmed by cDNA sequencing and mRNA rescue. Transmission electron microscopy (TEM) and image quantification were used to identify the cellular basis of hypopigmentation. Whole-genome sequencing and SNP mapping identified a nonsense mutation in the N-ethylmaleimide-sensitive factor b (nsfb) gene in au18 mutants. Complementary DNA sequencing confirmed the presence of the mutation (C893T), which truncates the nsfb protein by roughly two-thirds (Y297X). No coding sequence mutations were identified in au13, but quantitative PCR revealed a significant decrease in nsfb expression, and nsfb mRNA injection rescued the hypopigmentation phenotype, suggesting a regulatory mutation. In situ hybridization revealed that nsfb is broadly expressed during embryonic development, including in the RPE. Transmission electron microscopy analyses indicated that average melanosome density and maturity were significantly decreased in nsfb mutants. au18 and au13 contain mutations in nsfb, which encodes a protein that is required for the maturation of melanosomes in zebrafish RPE.

  6. The maintenance of long-term memory in the hippocampus depends on the interaction between N-ethylmaleimide-sensitive factor and GluA2.

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    Migues, Paola Virginia; Hardt, Oliver; Finnie, Peter; Wang, Yu Wang; Nader, Karim

    2014-09-01

    The maintenance of established memories has recently been shown to involve the stabilization of GluA2-containing AMPA receptors (GluA2/AMPARs) at postsynaptic membranes. Previous studies have suggested that N-ethylmaleimide-sensitive factor (NSF) regulates the stabilization of AMPARs at the synaptic membrane. We therefore disrupted the interaction between GluA2 and NSF in the dorsal hippocampus and examined its effect on the maintenance of object location and contextual fear memory. We used two interference peptides, pep2m and pepR845A, that have been shown to block the binding of NSF to GluA2 and reduce GluA2 synaptic content. Either peptide disrupted consolidated memory, and these effects persisted for at least 5 or 28 days after peptide administration. Following peptide administration and long-term memory disruption, rats were able to acquire new memories. Memory acquisition or consolidation was not impaired when pepR845A was given immediately before the training sessions. Blocking GluA2 endocytosis with the peptide GluA23Y prevented the memory impairment effect of pepR845A. Taken together, our results indicate that the persistence of long-term memory depends on the maintenance of a steady-state level of synaptic GluA2/AMPARs, which requires the interaction of NSF with GluA2. © 2014 Wiley Periodicals, Inc.

  7. The Q-soluble N-Ethylmaleimide-sensitive Factor Attachment Protein Receptor (Q-SNARE) SNAP-47 Regulates Trafficking of Selected Vesicle-associated Membrane Proteins (VAMPs)*

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    Kuster, Aurelia; Nola, Sebastien; Dingli, Florent; Vacca, Barbara; Gauchy, Christian; Beaujouan, Jean-Claude; Nunez, Marcela; Moncion, Thomas; Loew, Damarys; Formstecher, Etienne; Galli, Thierry; Proux-Gillardeaux, Veronique

    2015-01-01

    SNAREs constitute the core machinery of intracellular membrane fusion, but vesicular SNAREs localize to specific compartments via largely unknown mechanisms. Here, we identified an interaction between VAMP7 and SNAP-47 using a proteomics approach. We found that SNAP-47 mainly localized to cytoplasm, the endoplasmic reticulum (ER), and ERGIC and could also shuttle between the cytoplasm and the nucleus. SNAP-47 preferentially interacted with the trans-Golgi network VAMP4 and post-Golgi VAMP7 and -8. SNAP-47 also interacted with ER and Golgi syntaxin 5 and with syntaxin 1 in the absence of Munc18a, when syntaxin 1 is retained in the ER. A C-terminally truncated SNAP-47 was impaired in interaction with VAMPs and affected their subcellular distribution. SNAP-47 silencing further shifted the subcellular localization of VAMP4 from the Golgi apparatus to the ER. WT and mutant SNAP-47 overexpression impaired VAMP7 exocytic activity. We conclude that SNAP-47 plays a role in the proper localization and function of a subset of VAMPs likely via regulation of their transport through the early secretory pathway. PMID:26359495

  8. The Q-soluble N-Ethylmaleimide-sensitive Factor Attachment Protein Receptor (Q-SNARE) SNAP-47 Regulates Trafficking of Selected Vesicle-associated Membrane Proteins (VAMPs).

    Science.gov (United States)

    Kuster, Aurelia; Nola, Sebastien; Dingli, Florent; Vacca, Barbara; Gauchy, Christian; Beaujouan, Jean-Claude; Nunez, Marcela; Moncion, Thomas; Loew, Damarys; Formstecher, Etienne; Galli, Thierry; Proux-Gillardeaux, Veronique

    2015-11-20

    SNAREs constitute the core machinery of intracellular membrane fusion, but vesicular SNAREs localize to specific compartments via largely unknown mechanisms. Here, we identified an interaction between VAMP7 and SNAP-47 using a proteomics approach. We found that SNAP-47 mainly localized to cytoplasm, the endoplasmic reticulum (ER), and ERGIC and could also shuttle between the cytoplasm and the nucleus. SNAP-47 preferentially interacted with the trans-Golgi network VAMP4 and post-Golgi VAMP7 and -8. SNAP-47 also interacted with ER and Golgi syntaxin 5 and with syntaxin 1 in the absence of Munc18a, when syntaxin 1 is retained in the ER. A C-terminally truncated SNAP-47 was impaired in interaction with VAMPs and affected their subcellular distribution. SNAP-47 silencing further shifted the subcellular localization of VAMP4 from the Golgi apparatus to the ER. WT and mutant SNAP-47 overexpression impaired VAMP7 exocytic activity. We conclude that SNAP-47 plays a role in the proper localization and function of a subset of VAMPs likely via regulation of their transport through the early secretory pathway. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. A library of 7TM receptor C-terminal tails - Interactions with the proposed post-endocytic sorting proteins ERM-binding phosphoprotein 50 (EBP50), N-ethylmaleimide-sensitive factor (NSF), sorting nexin 1 (SNX1), and G protein-coupled receptor-associated sorting protein (GASP)

    DEFF Research Database (Denmark)

    Heydorn, A.; Sondergaard, B.P.; Ersbøll, Bjarne Kjær

    2004-01-01

    sequestration through interactions, mainly with the C-terminal intracellular tails of the receptors. A library of tails from 59 representative members of the super family of seven-transmembrane receptors was probed as glutathione S-transferase fusion proteins for interactions with four different adaptor...... only a single receptor tail, i.e. the beta(2)-adrenergic receptor, whereas N-ethylmaleimide-sensitive factor bound 11 of the tail-fusion proteins. Of the two proteins proposed to target receptors for lysosomal degradation, sorting nexin 1 (SNX1) bound 10 and the C-terminal domain of G protein......-coupled receptor-associated sorting protein bound 23 of the 59 tail proteins. Surface plasmon resonance analysis of the binding kinetics of selected hits from the glutathione S-transferase pull-down experiments, i.e. the tails of the virally encoded receptor US28 and the delta-opioid receptor, confirmed...

  10. Soluble collagen approach to a combination tannage mechanism

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    Although complex salts of Cr(III) sulfate are currently the most effective tanning agents, salts of other metals, including aluminum, have been used either alone or in combination with vegetable tannins or other organic chemicals. In the present study, the interactions of aluminum sulfate, and quebr...

  11. Combined experimental and computational modelling studies of the solubility of nickel in strontium titanate

    NARCIS (Netherlands)

    Beale, A.M.; Paul, M.; Sankar, G.; Oldman, R.J.; Catlow, R.A.; French, S.; Fowles, M.

    2009-01-01

    A combination of X-ray techniques and atomistic computational modelling has been used to study the solubility of Ni in SrTiO3 in relation to the application of this material for the catalytic partial oxidation of methane. The experiments have demonstrated that low temperature, hydrothermal synthesis

  12. Optimal Solubility of Diclofenac β-Cyclodextrin in Combination with Local Anaesthetics for Mesotherapy Applications

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    Giuseppe Tringali

    2017-01-01

    Full Text Available Because of low injection volume, the recently marketed injectable solution of diclofenac in complex with β-cyclodextrin (Akis®, IBSA Farmaceutici Italia is an ideal candidate for mesotherapy applications. In this study, we investigated the solubility of Akis, 25 and 50 mg/kg, in combination with various local anaesthetics (lidocaine, mepivacaine, bupivacaine, levobupivacaine, and ropivacaine at different concentrations in aqueous vehicles (normal saline, sterile water, or bicarbonate. Final injection mixtures were classified as limpid, turbid, or milky at visual analysis under standardized conditions. We found that (i the use of sterile water for injections or normal saline as vehicles to dilute Akis in combination with whatever local anaesthetic normally results in milky solutions and therefore is not recommended; (ii using bicarbonate, optimal solubility was obtained combining Akis with lidocaine, both 1 and 2%, or mepivacaine, both 1 and 2%, whereas solutions were turbid in combination with bupivacaine, levobupivacaine, or ropivacaine. Thus, we recommend that Akis is used in combination with lidocaine or mepivacaine in a bicarbonate vehicle.

  13. Optimal Solubility of Diclofenac β-Cyclodextrin in Combination with Local Anaesthetics for Mesotherapy Applications.

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    Tringali, Giuseppe; Navarra, Pierluigi

    2017-01-01

    Because of low injection volume, the recently marketed injectable solution of diclofenac in complex with β-cyclodextrin (Akis®, IBSA Farmaceutici Italia) is an ideal candidate for mesotherapy applications. In this study, we investigated the solubility of Akis, 25 and 50 mg/kg, in combination with various local anaesthetics (lidocaine, mepivacaine, bupivacaine, levobupivacaine, and ropivacaine) at different concentrations in aqueous vehicles (normal saline, sterile water, or bicarbonate). Final injection mixtures were classified as limpid, turbid, or milky at visual analysis under standardized conditions. We found that (i) the use of sterile water for injections or normal saline as vehicles to dilute Akis in combination with whatever local anaesthetic normally results in milky solutions and therefore is not recommended; (ii) using bicarbonate, optimal solubility was obtained combining Akis with lidocaine, both 1 and 2%, or mepivacaine, both 1 and 2%, whereas solutions were turbid in combination with bupivacaine, levobupivacaine, or ropivacaine. Thus, we recommend that Akis is used in combination with lidocaine or mepivacaine in a bicarbonate vehicle.

  14. Interactions between N-Ethylmaleimide-sensitive factor and GluA2 contribute to effects of glucocorticoid hormones on AMPA receptor function in the rodent hippocampus.

    NARCIS (Netherlands)

    Xiong, H.; Cassé, F.; Zhou, M.; Xiong, Z.Q.; Joels, M.; Martin, S.; Krugers, H.J.

    2016-01-01

    Glucocorticoid hormones, via activation of their receptors, promote memory consolidation, but the exact underlying mechanisms remain elusive. We examined how corticosterone regulates AMPA receptor (AMPAR) availability in the synapse, which is important for synaptic plasticity and memory formation.

  15. Interactions between N-Ethylmaleimide-Sensitive Factor and GluA2 contribute to effects of glucocorticoid hormones on AMPA receptor function in the rodent hippocampus

    NARCIS (Netherlands)

    Xiong, Hui; Cassé, Frédéric; Zhou, Ming; Xiong, Zhi-Qi; Joels, Marian; Martin, Stéphane; Krugers, Harm J

    Glucocorticoid hormones, via activation of their receptors, promote memory consolidation, but the exact underlying mechanisms remain elusive. We examined how corticosterone regulates AMPA receptor (AMPAR) availability in the synapse, which is important for synaptic plasticity and memory formation.

  16. Does serum lactate combined with soluble endothelial selectins at ICU admission predict sepsis development?

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    Vassiliou, Alice G; Mastora, Zafeiria; Jahaj, Edison; Koutsoukou, Antonia; Orfanos, Stylianos E; Kotanidou, Anastasia

    2015-01-01

    We sought to determine for serum lactate its specificity and sensitivity in sepsis development prognosis in critically-ill, non-septic patients. Additionally, we evaluated whether sE-selectin or sP-selectin add prognostic value to lactate in sepsis. Using a cohort previously studied in another context, in this retrospective investigation we plotted receiver operating characteristic (ROC) curves using sepsis development as the classification variable and serum lactate levels and their linear combinations with soluble sE-selectin and/or sP-selectin levels at intensive care unit (ICU) admission, as prognostic variables. Lactate levels combined with sE- and sP-selectin levels have the best prognostic accuracy showing a sensitivity and specificity of 76% and 84%, respectively, and an area under the curve (AUC) at 0.854 (95% confidence interval (CI)=0.775-0.932; p<0.001). In our patient cohort, combining sE- and sP-selectin with serum lactate offers better prognostic value for sepsis development during ICU hospitalization. Copyright © 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  17. Fermentation of rapeseed meal, sunflower meal and faba beans in combination with wheat bran increases solubility of protein and phosphorus.

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    Poulsen, Hanne Damgaard; Blaabjerg, Karoline

    2017-01-01

    To increase self-supply of protein and phosphorus (P) in European pig and poultry diets and reduce nitrogen (N) and P excretion, attention is directed to approaches increasing protein and P digestibility of rapeseed, sunflower and faba beans. Wheat bran is rich in enzymes degrading and solubilizing protein and phytate. Herein, solubilization of protein, N and P was investigated when increasing ratios of wheat bran were fermented with rapeseed meal (RSM), sunflower meal (SFM), faba beans (FB) or a combination of these (RSM/SFM/FB). Protein, N and P solubility was greater, for all mixtures, the more wheat bran was included and the longer the mixtures were fermented. The increase in N (FB > RSM/SFM/FB > SFM > RSM) and protein solubility (RSM/SFM/FB > RSM > SFM > FB) was greatest from day 0 to day 3 and thereafter limited, whereas P solubility increased during the whole period (5 days; FB > RSM/SFM/FB > SFM > RSM). In general, FB showed the highest solubility and highest increase in N and P solubility, while RSM showed the highest protein solubility and RSM/SFM/FB the highest increase in protein solubility. Fermentation of RSM, SFM, FB and RSM/SFM/FB without or with wheat bran uncovers a potential for increased protein and P digestibility and thereby reduced N and P excretion from pigs and poultry. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  18. Use of surfactants as plasticizers in preparing solid dispersions of poorly soluble API: selection of polymer-surfactant combinations using solubility parameters and testing the processability.

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    Ghebremeskel, Alazar N; Vemavarapu, Chandra; Lodaya, Mayur

    2007-01-10

    Formation of solid dispersions as a means to enhance the dissolution rate of poorly soluble Active pharmaceutical ingredients (APIs) typically employs hydrophilic polymer systems and surfactants. While the utility of the surfactant systems in solubilization is well known, the secondary effects of the same on processing and subsequent physical stability of the solid dispersions needs to be studied further. Physical blends of the poorly soluble API and hydrophilic polymers such as PVP-K30, Plasdone-S630, HPMC-E5, HPMCAS, and Eudragit L100 with mass ratio 1:1 were prepared. The surfactants tested in this study included Tween-80, Docusate sodium, Myrj-52, Pluronic-F68 and SLS. Thermal analysis of the API-polymer-surfactant blends suggested that the surfactants caused solvation/plasticization, manifesting in reduction of (i) the melting (T(m)) of API (ii) T(g) of the polymers and (iii) the combined T(g) of the solid dispersion formed from quench cooling. Explanation of these effects of surfactants is attempted based on their physical state (at the temperature of interest), HLB values and similarity of their solubility parameter values with respect to drug-polymer systems. Furthermore, extruded matrices containing different API-polymer (PVP-K30, Plasdone-S630, and HPMC-E5) mixtures prepared with and without surfactants, were produced by feeding the powder blend through a hot-melt extruder. The melt viscosity of the polymer blends was assessed by torque rheometry using a Haake Rheomix. The physicochemical properties of the extruded API-polymer-surfactant were characterized by differential scanning calorimetry, X-ray diffraction, Raman spectroscopy, and polarized microscopy. The results demonstrated that the glass transition temperature of the carrier polymers decreased as direct result of the surfactants in the extrudate, due to an increase in the chain mobility of polymers. A decrease in the melt viscosity was seen due to a plasticization of the polymer. The drug release

  19. Evaluation of the general conditions and inflammatory response of antibiotics combined with fat-soluble vitamin therapy for pediatric pneumonia

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    Qiao-Li Chai

    2017-08-01

    Full Text Available Objective: To evaluate the general conditions and inflammatory response of antibiotics combined with fat-soluble vitamin therapy for pediatric pneumonia. Methods: A total of 350 children with pneumonia who were treated in our hospital between January 2014 and January 2017 were collected and divided into control group and observation group according to the random number table, 175 cases in each group. Control group received azithromycin therapy, and observation group received azithromycin combined with fat-soluble vitamin therapy. The differences in the systemic and inflammatory responses before and after treatment were compared between the two groups of patients. Results: Before treatment, differences in blood routine index levels as well as serum contents of oxidative stress indexes and inflammatory factors were not statistically significant between two groups of patients. After treatment, white blood cell count, neutrophil ratio as well as serum CRP, PCT, IL-6 and TNF-α contents of both groups were lower than those before treatment while lymphocyte ratio as well as serum IgA, IgG and IgM contents were higher than those before treatment, and white blood cell count, neutrophil ratio as well as serum CRP, PCT, IL-6 and TNF-α contents of observation group after treatment were lower than those of control group while lymphocyte ratio as well as serum IgA, IgG and IgM contents was higher than those of control group. Conclusion: Antibiotics combined with fat-soluble vitamin therapy for pediatric pneumonia can effectively optimize the patient's general conditions and reduce the inflammatory response.

  20. Fermentation of rapeseed meal, sunflower meal and faba beans in combination with wheat bran increases solubility of protein and phosphorus

    DEFF Research Database (Denmark)

    Poulsen, Hanne Damgaard; Blaabjerg, Karoline

    2017-01-01

    BACKGROUND To increase self-supply of protein and phosphorus (P) in European pig and poultry diets and reduce nitrogen (N) and P excretion, attention is directed to approaches increasing protein and P digestibility of rapeseed, sunflower and faba beans. Wheat bran is rich in enzymes degrading...... and solubilizing protein and phytate. Herein, solubilization of protein, N and P was investigated when increasing ratios of wheat bran were fermented with rapeseed meal (RSM), sunflower meal (SFM), faba beans (FB) or a combination of these (RSM/SFM/FB). RESULTS Protein, N and P solubility was greater, for all...

  1. Combination effect on HIV infection in vitro of soluble CD4 and HIV-neutralizing antibodies

    DEFF Research Database (Denmark)

    Hansen, J E; Sørensen, A M; Olofsson, S

    1994-01-01

    In combination with HIV gp120 V3-loop antibody, two carbohydrate specific neutralizing antibodies (83D4 and 2G12) had a synergistic neutralizing effect on HIV infection. However, sCD4 and an antibody which blocks gp 120/CD4 binding (1B1) both displayed antagonism.......In combination with HIV gp120 V3-loop antibody, two carbohydrate specific neutralizing antibodies (83D4 and 2G12) had a synergistic neutralizing effect on HIV infection. However, sCD4 and an antibody which blocks gp 120/CD4 binding (1B1) both displayed antagonism....

  2. Combined use of ordered mesoporous silica and precipitation inhibitors for improved oral absorption of the poorly soluble weak base itraconazole.

    Science.gov (United States)

    Van Speybroeck, Michiel; Mols, Raf; Mellaerts, Randy; Thi, Thao Do; Martens, Johan A; Van Humbeeck, Jan; Annaert, Pieter; Van den Mooter, Guy; Augustijns, Patrick

    2010-08-01

    The release of poorly soluble drugs from mesoporous silicates is often associated with the generation of supersaturation, which implies the risk of drug precipitation and reduced availability for absorption. The aim of this study was to enhance the in vivo performance of an ordered mesoporous silicate (SBA-15) by combining it with the precipitation inhibitors hydroxypropylmethylcellulose (HPMC) and hydroxypropylmethylcellulose acetate succinate (HPMCAS). The poorly soluble weak base itraconazole was used as a model compound. Formulations were prepared by physically blending itraconazole-loaded SBA-15 with the precipitation inhibitors. In vitro release experiments implementing a transfer from simulated gastric fluid to simulated intestinal fluid were used to evaluate the pharmaceutical performance. Subsequently, the formulations were evaluated in vivo in rats. When high enough amounts of HPMC were co-administered with itraconazole-loaded SBA-15 (itraconazole:SBA-15:HPMC 1:4:6), the extent of absorption was increased by more than 60% when compared to SBA-15 without precipitation inhibitors (AUC 14,937+/-1617 versus 8987+/-2726nMh). HPMCAS was found ineffective in enhancing the in vivo performance of SBA-15 due to its insolubility in the stomach. The results of this study demonstrate that the pharmaceutical performance of SBA-15 is enhanced through addition of an appropriate precipitation inhibitor.

  3. Water-soluble polymer–drug conjugates for combination chemotherapy against visceral leishmaniasis

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    Nicoletti, Salvatore; Seifert, Karin; Gilbert, Ian H.

    2010-01-01

    There is a need for new safe, effective and short-course treatments for leishmaniasis; one strategy is to use combination chemotherapy. Polymer–drug conjugates have shown promise for the delivery of anti-leishmanial agents such as amphotericin B. In this paper, we report on the preparation and biological evaluation of polymer–drug conjugates of N-(2-hydroxypropyl)methacrylamide (HPMA), amphotericin B and alendronic acid. The combinatorial polymer–drug conjugates were effective anti-leishmanial agents in vitro and in vivo, but offered no advantage over the single poly(HPMA)–amphotericin B conjugates. PMID:20338769

  4. A Combination of Radiosurgery and Soluble Tissue Factor Enhances Vascular Targeting for Experimental Glioblastoma

    Directory of Open Access Journals (Sweden)

    Jian Tu

    2013-01-01

    Full Text Available Radiosurgery for glioblastoma is limited to the development of resistance, allowing tumor cells to survive and initiate tumor recurrence. Based on our previous work that coadministration of tissue factor and lipopolysaccharide following radiosurgery selectively induced thrombosis in cerebral arteriovenous malformations, achieving thrombosis of 69% of the capillaries and 39% of medium sized vessels, we hypothesized that a rapid and selective shutdown of the capillaries in glioblastoma vasculature would decrease the delivery of oxygen and nutrients, reducing tumor growth, preventing intracranial hypertension, and improving life expectancy. Glioblastoma was formed by implantation of GL261 cells into C57Bl/6 mouse brain. Mice were intravenously injected tissue factor, lipopolysaccharide, a combination of both, or placebo 24 hours after radiosurgery. Control mice received both agents after sham irradiation. Coadministration of tissue factor and lipopolysaccharide led to the formation of thrombi in up to 87 ± 8% of the capillaries and 46 ± 4% of medium sized vessels within glioblastoma. The survival rate of mice in this group was 80% versus no survivor in placebo controls 30 days after irradiation. Animal body weight increased with time in this group (r=0.88, P=0.0001. Thus, radiosurgery enhanced treatment with tissue factor, and lipopolysaccharide selectively induces thrombosis in glioblastoma vasculature, improving life expectancy.

  5. Effects of feeding condensed distillers solubles and crude glycerin alone or in combination on finishing beef cattle performance, carcass characteristics, and in vitro fermentation.

    Science.gov (United States)

    Two experiments were conducted to evaluate the effects of feeding condensed distillers solubles (DS) and crude glycerin alone or in combination on performance of finishing beef cattle and in vitro fermentation. In both experiments, dietary treatments consisted of a steam flaked corn (SFC) based diet...

  6. [Near-infrared hyperspectral imaging combined with CARS algorithm to quantitatively determine soluble solids content in "Ya" pear].

    Science.gov (United States)

    Li, Jiang-Bo; Peng, Yan-Kun; Chen, Li-Ping; Huang, Wen-Qian

    2014-05-01

    The present study proposed competitive adaptive reweighted sampling (CARS) algorithm to be used to select the key variables from near-infrared hyperspectral imaging data of "Ya" pear. The performance of the developed model was evaluated in terms of the coefficient of determination(r2), and the root mean square error of prediction (RMSEP) and the ratio (RPD) of standard deviation of the validation set to standard error of prediction were used to evaluate the performance of proposed model in the prediction process. The selected key variables were used to build the PLS model, called CARS-PLS model. Comparing results obtained from CARS-PLS model and results obtained from full spectra PLS, it was found that the better results (r(2)pre = 0. 908 2, RMSEP=0. 312 0 and RPD=3. 300 5) were obtained by CARS-PLS model based on only 15. 6% information of full spectra. Moreover, performance of CARS-PLS model was also compared with PLS models built by using variables got by Monte Carlo-uninformative variable elimination (MC-UVE) and genetic algorithms (GA) method. The result found that CARS variable selection algorithm not only can remove the uninformative variables in spectra, but also can reduce the collinear variables from informative variables. Therefore, this method can be used to select the key variables of near-infrared hyperspectral imaging data. This study showed that near-infrared hyperspectral imaging technology combined with CARS-PLS model can quantitatively predict the soluble solids content (SSC) in "Ya" pear. The results presented from this study can provide a reference for predicting other fruits quality by using the near-infrared hyperspectral imaging.

  7. Equations for O2 and CO2 solubilities in saline and plasma: combining temperature and density dependences.

    Science.gov (United States)

    Christmas, Kevin M; Bassingthwaighte, James B

    2017-05-01

    Solubilities of respiratory gasses in water, saline, and plasma decrease with rising temperatures and solute concentrations. Henry's Law, C = α·P, states that the equilibrium concentration of a dissolved gas is solubility times partial pressure. Solubilities in the water of a solution depend on temperature and the content of other solutes. Blood temperatures may differ more than 20°C between skin and heart, and an erythrocyte will undergo that range as blood circulates. The concentrations of O2 and CO2 are the driving forces for diffusion, exchanges, and for reactions. We provide an equation for O2 and CO2 solubilities, α, that allows for continuous changes in temperature, T, and solution density, ρ, in dynamically changing states:[Formula: see text]This two-exponential expression with a density scalar γ, and a density exponent β, accounts for solubility changes due to density changes of an aqueous solution. It fits experimental data on solubilities in water, saline, and plasma over temperatures from 20 to 40°C, and for plasma densities, ρsol up to 1.020 g/ml with ~0.3% error. The amounts of additional bound O2 (to Hb) and CO2 (bicarbonate and carbamino) depend on the concentrations in the local water space and the reaction parameters. During exercise, solubility changes are large; both ρsol and T change rapidly with spatial position and with time. In exercise hemoconcentration plasma, ρsol exceeds 1.02, whereas T may range over 20°C. The six parameters for O2 and the six for CO2 are constants, so solubilities are calculable continuously as T and ρsol change.NEW & NOTEWORTHY Solubilities for oxygen and carbon dioxide are dependent on the density of the solution, on temperature, and on the partial pressure. We provide a brief equation suitable for hand calculators or mathematical modeling, accounting for these factors over a wide range of temperatures and solution densities for use in rapidly changing conditions, such as extreme exercise or osmotic

  8. Concentrations of tumour necrosis factor-α and its soluble receptors in the serum of teenagers with atherosclerosis risk factors: obesity or obesity combined with hypertension.

    Science.gov (United States)

    Obuchowicz, Anna; Kniażewska, Maria; Zmudzińska-Kitczak, Joanna; Urban, Katarzyna; Gonciarz-Majda, Anna

    2014-11-01

    Obesity and hypertension are recognised risk factors for the development of atherosclerosis. It has not been proven whether their co-existence increases the synthesis of pro-inflammatory TNF-α and what the levels of soluble receptors of this cytokine (sTNF-R) are. This study is aimed to investigate whether there exists a relationship between TNF-α and sTNF-R concentrations in blood serum with the occurrence of obesity or obesity combined with primary hypertension in teenagers. 68 persons, aged 9-17, including 32 persons with primary obesity (Group I) and 36 with primary obesity combined with primary hypertension (Group II). TNF-α (pg/mL) and sTNF-R (ng/mL) concentrations were determined in serum samples using the ELISA method with sets of reagents manufactured by Bender Med Systems GmbH. No significant differences in TNF-α, sTNF-R, glucose or insulin concentrations were found between Group I and Group II. These concentrations were not correlated with the age and the nutritional status of the patients or with each other in either of the groups. Both obese teenagers and teenagers exhibiting obesity combined with hypertension (as two atherosclerosis risk factors) are characterised by comparable concentrations of TNF-α and its soluble receptors.

  9. Developmental and Diurnal Expression of the Synaptosomal-Associated Protein 25 (Snap25) in the Rat Pineal Gland

    DEFF Research Database (Denmark)

    Karlsen, Anna S; Rath, Martin Fredensborg; Rohde, Kristian

    2013-01-01

    Snap25 (synaptosomal-associated protein) is a 25 kDa protein, belonging to the SNARE-family (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) of proteins, essential for synaptic and secretory vesicle exocytosis. Snap25 has by immunohistochemistry been demonstrated in the rat...

  10. Feasibility studies of dermal delivery of paclitaxel with binary combinations of ethanol and isopropyl myristate: role of solubility, partitioning and lipid bilayer perturbation.

    Science.gov (United States)

    Panchagnula, Ramesh; Desu, Hariraghuram; Jain, Amit; Khandavilli, Sateesh

    2005-01-01

    In the current investigation, paclitaxel (PCL) delivery into the different layers of skin, vehicle optimization and relationship between vehicle composition and the relative contribution of solubility, partition and diffusion towards drug transport has been outlined. Saturation solubility of PCL was determined in ethanol (EtOH), isopropyl myristate (IPM) and their binary combinations, and partition studies performed to study the probability of skin depot formation. Epidermal and dermal partitioning was carried from PCL saturated vehicles. Skin permeation of PCL was studied using the rat skin. FT-IR has been utilized to study the skin barrier perturbation, and the localization of PCL and isopropyl myristate (IPM) in epidermis. High K(app) value in mineral oil/buffer indicated the tendency of PCL to form a reservoir in skin, and an inverse relationship between PCL solubility in different solvent systems and partitioning into epidermis was found. Maximum K(epidermis) for PCL was observed with IPM, while PCL in EtOH/IPM (1:1) showed high partitioning into dermis. Maximum flux of PCL was observed with EtOH/IPM (1:1). For lipophilic drug like PCL modulation of vehicle seems to be effective approach to increase the permeability across the skin. With a binary combination of EtOH/IPM (1:1) higher concentration of PCL can be delivered to deeper layer of skin whereas with IPM higher concentration of PCL could be localized in the epidermis. While engineering the delivery vehicle selection of solvents should be such that one of them is miscible in both hydrophilic and lipophilic phase like ethanol and another should be lipophilic in nature (IPM in this case) so that an optimum balance between 'push-pull' and 'blending' effect can be achieved.

  11. Effects of feeding condensed distiller's solubles and crude glycerin alone or in combination on finishing beef cattle performance, carcass characteristics, and in vitro fermentation.

    Science.gov (United States)

    Weiss, C P; Gentry, W W; Cole, N A; McCollum, F T; Jennings, J S

    2017-02-01

    Two experiments were conducted to evaluate the effects of feeding condensed distiller's solubles (DS) and crude glycerin alone or in combination on performance of finishing beef cattle and in vitro fermentation. In both experiments, dietary treatments consisted of a steam-flaked corn-based diet with 0% DS or crude glycerin (CON), 10% DS (CDS), 10% crude glycerin (GLY), or a combination of 5% DS and 5% crude glycerin (C+G) included on a DM basis. All treatment diets contained 15% (DM basis) wet distiller's grains plus solubles. In Exp. 1, crossbred steers ( = 256; 322 ± 15 kg initial BW) were used in a randomized complete block finishing trial. Growth performance and gain efficiency were not different ( > 0.10) across all treatments. Treatment had no effect ( > 0.10) on carcass weight, marbling score, yield grade, LM area, or percent grading USDA choice. In Exp. 2, ruminal fluid was collected from 2 ruminally cannulated steers to evaluate in vitro fermentation characteristics. No differences ( = 0.43) were observed for DM disappearance across all treatments. The GLY and C+G treatments had decreased ( = 0.02 and = 0.05, respectively) NDF disappearance (NDFD), whereas the CDS treatment tended to have decreased ( = 0.06) NDFD compared with CON. Concentrations of NH decreased ( 0.17) on concentrations of acetate, propionate, and butyrate, but valerate concentrations were the greatest ( glycerin in the substrates decreased ( glycerin alone or in combination in a finishing diet did not alter live animal performance or carcass characteristics; however, feeding a combination of the 2 byproducts may alter in vitro fermentation.

  12. Nanoparticle-delivered multimeric soluble CD40L DNA combined with Toll-Like Receptor agonists as a treatment for melanoma.

    Directory of Open Access Journals (Sweden)

    Geoffrey W Stone

    2009-10-01

    Full Text Available Stimulation of CD40 or Toll-Like Receptors (TLR has potential for tumor immunotherapy. Combinations of CD40 and TLR stimulation can be synergistic, resulting in even stronger dendritic cell (DC and CD8+ T cell responses. To evaluate such combinations, established B16F10 melanoma tumors were injected every other day X 5 with plasmid DNA encoding a multimeric, soluble form of CD40L (pSP-D-CD40L either alone or combined with an agonist for TLR1/2 (Pam(3CSK(4 , TLR2/6 (FSL-1 and MALP2, TLR3 (polyinosinic-polycytidylic acid, poly(I:C, TLR4 ( monophosphoryl lipid A, MPL, TLR7 (imiquimod, or TLR9 (Class B CpG phosphorothioate oligodeoxynucleotide, CpG. When used by itself, pSP-D-CD40L slowed tumor growth and prolonged survival, but did not lead to cure. Of the TLR agonists, CpG and poly(I:C also slowed tumor growth, and the combination of these two TLR agonists was more effective than either agent alone. The triple combination of intratumoral pSP-D-CD40L + CpG + poly(I:C markedly slowed tumor growth and prolonged survival. This treatment was associated with a reduction in intratumoral CD11c+ dendritic cells and an influx of CD8+ T cells. Since intratumoral injection of plasmid DNA does not lead to efficient transgene expression, pSP-D-CD40L was also tested with cationic polymers that form DNA-containing nanoparticles which lead to enhanced intratumoral gene expression. Intratumoral injections of pSP-D-CD40L-containing nanoparticles formed from polyethylenimine (PEI or C32 (a novel biodegradable poly(B-amino esters polymer in combination with CpG + poly(I:C had dramatic antitumor effects and frequently cured mice of B16F10 tumors. These data confirm and extend previous reports that CD40 and TLR agonists are synergistic and demonstrate that this combination of immunostimulants can significantly suppress tumor growth in mice. In addition, the enhanced effectiveness of nanoparticle formulations of DNA encoding immunostimulatory molecules such as multimeric

  13. Effect of azithromycin combined with fat-soluble vitamin on serum inflammatory cytokines and chemokines as well as lung function in children with mycoplasma pneumonia

    Directory of Open Access Journals (Sweden)

    Ming-Guang Yang1

    2017-04-01

    Full Text Available Objective: To study the effect of azithromycin combined with fat-soluble vitamin on serum inflammatory cytokines and chemokines as well as lung function in children with mycoplasma pneumonia. Methods: 56 children with mycoplasma pneumonia admitted in our hospital between May 2012 and May 2016 were collected, the treatment methods and laboratory test results were retrospectively analyzed, and then they were divided into the control group (n=26 who received azithromycin treatment alone and the observation group (n=30 who received fatsoluble vitamin combined with azithromycin treatment. Before treatment and after 1 week of treatment, enzyme-linked immunosorbent assay (ELISA was used to detect the serum levels of inflammatory cytokines and chemokines; lung function monitor for children was used to detect lung function index levels. Results: Before treatment, differences in serum inflammation index and chemokine contents as well as lung function indexes were not statistically significant between two groups of patients (P>0.05. After treatment, serum inflammation indexes IL-4 and IL-13 contents of observation group were lower than those of control group while IL- 10 and IL-12 contents were higher than those of control group (P<0.05; serum chemokines MCP-4, MDC and CysLTs contents of observation group were lower than those of control group (P<0.05; lung function indexes V-T, FEV1, PEF and MMEF25%-75% levels of observation group were higher than those of control group (P<0.05. Conclusion: Fat-soluble vitamin combined with azithromycin can reduce the systemic inflammatory response and optimize the lung function in children with mycoplasma pneumoniae infection.

  14. Biofuel Co-products as Swine Feed Ingredients: Combining Distillers Dried Grains with Solubles (DDGS) and Crude Glycerin

    Science.gov (United States)

    The objective of this study was to examine the effects of combining corn DDGS with crude glycerin on growth performance and carcass traits to determine if a high level of crude glycerin supplementation could counteract the impact of corn DDGS on fatty acid profile of pork adipose. The experimental d...

  15. Use of plasma C-reactive protein, procalcitonin, neutrophils,macrophage migration inhibitory factor, soluble urokinase-type plasminogen activator receptor, and soluble triggering receptor expressed on myeloid cells-1 in combination to diagnose infections: a prospective study

    DEFF Research Database (Denmark)

    Kofoed, Kristian; Andersen, Ove; Kronborg, Gitte

    2007-01-01

    department and department of infectious diseases at a university hospital. A multiplex immunoassay measuring soluble urokinase-type plasminogen activator (suPAR) and soluble triggering receptor expressed on myeloid cells (sTREM)-1 and macrophage migration inhibitory factor (MIF) was used in parallel...

  16. Solubility Database

    Science.gov (United States)

    SRD 106 IUPAC-NIST Solubility Database (Web, free access)   These solubilities are compiled from 18 volumes (Click here for List) of the International Union for Pure and Applied Chemistry(IUPAC)-NIST Solubility Data Series. The database includes liquid-liquid, solid-liquid, and gas-liquid systems. Typical solvents and solutes include water, seawater, heavy water, inorganic compounds, and a variety of organic compounds such as hydrocarbons, halogenated hydrocarbons, alcohols, acids, esters and nitrogen compounds. There are over 67,500 solubility measurements and over 1800 references.

  17. In vitro solubility, dissolution and permeability studies combined with semi-mechanistic modeling to investigate the intestinal absorption of desvenlafaxine from an immediate- and extended release formulation

    DEFF Research Database (Denmark)

    Franek, F; Jarlfors, A; Larsen, F.

    2015-01-01

    (ERF). Semi-mechanistic models of desvenlafaxine were built (using SimCyp®) by combining in vitro data on dissolution and permeation (mechanistic part of model) with clinical data (obtained from literature) on distribution and clearance (non-mechanistic part of model). The model predictions...... for desvenlafaxine absorption (i.e. intestinal dissolution or permeation) is not fully clarified. The aim of this study was to investigate whether dissolution and/or intestinal permeability rate-limit desvenlafaxine absorption from an immediate-release formulation (IRF) and Pristiq®, an extended release formulation...... of desvenlafaxine pharmacokinetics after IRF and ERF administration were compared with published clinical data from 14 trials. Desvenlafaxine in vivo dissolution from the IRF and ERF was predicted from in vitro solubility studies and biorelevant dissolution studies (using the USP3 dissolution apparatus...

  18. Nasal eosinophilia and serum soluble intercellular adhesion molecule 1 in patients with allergic rhinitis treated with montelukast alone or in combination with desloratadine or levocetirizine.

    Science.gov (United States)

    Ciebiada, Maciej; Barylski, Marcin; Gorska Ciebiada, Malgorzata

    2013-01-01

    Because intercellular adhesion molecule (ICAM) 1 and recruitment of eosinophils are crucial in supporting allergic inflammation, their down-regulation may bring additional benefits in patients' recovery. We have assessed nasal eosinophilia and serum soluble ICAM-1 (sICAM-1) concentrations in relation to nasal symptoms in patients with persistent allergic rhinitis (AR) treated for 6 weeks with either desloratadine, levocetirizine, montelukast alone, or in combination. In this single-center, randomized, double-blind, placebo-controlled, crossover, two-arm study, 40 patients with persistent AR were randomized to receive either montelukast and/or levocetirizine or placebo (n = 20) or to receive treatment with montelukast and/or desloratadine or placebo (n = 20). Nasal eosinophilia and concentration of sICAM-1 in peripheral blood were assessed before and on the last day of each treatment period. All active treatments in both arms of the study resulted in the decrease of sICAM-1 and nasal eosinophilia, which correlated with the severity of nasal symptoms. In the montelukast/levocetirizine arm, montelukast decreased nasal eosinophilia more significantly than levocetirizine, whereas in reduction of sICAM-1 all active treatment options were equally effective. However, in the desloratadine/montelukast arm, the resulting improvement of combination therapy of sICAM-1 and the influx of eosinophils was not statistically significant. The improvement of nasal symptoms in patients with AR treated with antihistamines, with or without montelukast, may additionally result from the reduction of sICAM-1 and nasal eosinophilia. Because the combination therapy may bring inconclusive benefits in this area there is a strong need of further studies to find mechanisms that favor combination therapy.

  19. Serum soluble CD26 levels: diagnostic efficiency for atopic dermatitis, cutaneous T-cell lymphoma and psoriasis in combination with serum thymus and activation-regulated chemokine levels.

    Science.gov (United States)

    Miyagaki, T; Sugaya, M; Suga, H; Morimura, S; Kamata, M; Ohmatsu, H; Fujita, H; Asano, Y; Tada, Y; Kadono, T; Sato, S

    2013-01-01

    CD26 is a multifunctional type II transmembrane glycoprotein, which also exists as a secreted isoform, soluble CD26 (sCD26). The CD26 expression on circulating T cells is decreased in some skin diseases such as cutaneous T-cell lymphoma (CTCL) and psoriasis. It remains to be determined whether sCD26 can be used as a marker of skin diseases or not. To investigate utility of sCD26 as a diagnostic marker of skin diseases in combination with thymus and activation-regulated chemokine (TARC). Serum sCD26 levels were measured using enzyme-linked immunosorbent assay in 130 participants including 32 patients with atopic dermatitis (AD); 45 patients with CTCL; 26 patients with psoriasis; and 27 healthy controls. Serum sCD26 levels in patients with CTCL and psoriasis (162.1 ± 80.2 ng/mL and 125.4 ± 82.1 ng/mL respectively) were significantly lower than those of healthy controls (392.6 ± 198.7 ng/mL; P psoriasis were 65.2-73.7%, 81.4-97.6%, 65.2-94.4%, and 81.4-88.9% respectively. Serum sCD26 levels, combined with serum TARC levels, are helpful in diagnosis of AD, CTCL and psoriasis. © 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.

  20. The combination of decoy receptor 3 and soluble triggering receptor expressed on myeloid cells-1 for the diagnosis of nosocomial bacterial meningitis.

    Science.gov (United States)

    Liu, Yong-Juan; Shao, Li-Hua; Zhang, Jian; Fu, Shan-Ji; Wang, Gang; Chen, Feng-Zhe; Zheng, Feng; Ma, Rui-Ping; Liu, Hai-Hong; Dong, Xiao-Meng; Ma, Li-Xian

    2015-03-23

    Early diagnosis and appropriate antibiotic treatment can significantly reduce mortality of nosocomial bacterial meningitis. However, it is a challenge for clinicians to make an accurate and rapid diagnosis of bacterial meningitis. This study aimed at determining whether combined biomarkers can provide a useful tool for the diagnosis of bacterial meningitis. A retrospective study was carried out. Cerebrospinal fluid (CSF) levels of decoy receptor 3 (DcR3) and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) were detected by enzyme-linked immunosorbent assay (ELISA). The patients with bacterial meningitis had significantly elevated levels of the above mentioned biomarkers. The two biomarkers were all risk factors with bacterial meningitis. The biomarkers were constructed into a "bioscore". The discriminative performance of the bioscore was better than that of each biomarker, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.842 (95% confidence intervals (CI) 0.770-0.914; pbacterial meningitis. The combined strategy is of interest and the validation of that improvement needs further studies.

  1. Rapid identification of human SNAP-25 transcript variants by a miniaturized capillary electrophoresis system.

    Science.gov (United States)

    Németh, Nóra; Kerékgyártó, Márta; Sasvári-Székely, Mária; Rónai, Zsolt; Guttman, András

    2014-02-01

    The 25 kDa synaptosomal-associated protein (SNAP-25) is a crucial component of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex and plays an important role in neurotransmission in the central nervous system. SNAP-25 has two different splice variants, SNAP-25a and SNAP-25b, differing in nine amino acids that results in a slight functional alteration of the generated soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex. Two independent techniques, a PCR-miniaturized CE method and a real-time PCR based approach were elaborated for the specific and quantitative detection of the two SNAP-25 transcription variants. DNA-constructs coding for the two isoforms were used for optimization. Excellent specificity was observed with the use of our previously described highly sensitive miniaturized CE system in combination with quantitative PCR. The ratio of the two isoforms were reliably detected in a range of at least four orders of magnitude with a linear regression of R(2) = 0.987. Expression of the two isoforms was determined in human samples, where SNAP-25 was detected even in non-neural tissues, although at approximately a 100-fold lower level compared to the central nervous system. The relative amount of the SNAP-25b isoform was higher in the brain, whereas expression of SNAP-25a variant proved to be slightly higher in extra-neural cell types. The genomics approach in conjunction with the miniaturized CE system introduced in this paper is readily applicable for rapid alternative splice variant analysis. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Soluble NCAM

    DEFF Research Database (Denmark)

    Secher, Thomas

    2008-01-01

    The neural cell adhesion molecule (NCAM) is a membrane-bound glycoprotein involved in homophilic interactions that facilitate cell-cell adhesion. In addition to a number of membrane-bound isoforms, NCAM also exists in several soluble isoforms that have been identified in cerebrospinal fluid, blood...... serum, brain tissue, and cell culture media. Soluble NCAM can be produced in a number of ways, such as alternative splicing of the transcript from NCAM1 and enzymatic processing of the extracellular domain at the cell membrane. Soluble NCAM interferes with homophilic NCAM interactions mediated...... by membrane-bound NCAM, thereby reducing NCAM-dependent adhesion, and can modulate neurite outgrowth in vitro-a property that likely is dose-dependent. The biological effects of overexpressing soluble NCAM in transgenic animals include a perturbation of synaptic connectivity and the development of abnormal...

  3. Post-exposure administration of diazepam combined with soluble epoxide hydrolase inhibition stops seizures and modulates neuroinflammation in a murine model of acute TETS intoxication

    Energy Technology Data Exchange (ETDEWEB)

    Vito, Stephen T., E-mail: stvito@ucdavis.edu [Department of Entomology, College of Agricultural and Environmental Sciences, University of California-Davis, Davis, CA 95616 (United States); Austin, Adam T., E-mail: aaustin@ucdavis.edu [Department of Pediatrics, School of Medicine, University of California-Davis Medical Center, Sacramento, CA 95817 (United States); Banks, Christopher N., E-mail: Christopher.Banks@oehha.ca.gov [Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616 (United States); Inceoglu, Bora, E-mail: abinceoglu@ucdavis.edu [Department of Entomology, College of Agricultural and Environmental Sciences, University of California-Davis, Davis, CA 95616 (United States); Bruun, Donald A., E-mail: dabruun@ucdavis.edu [Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616 (United States); Zolkowska, Dorota, E-mail: dzolkowska@gmail.com [Department of Neurology, School of Medicine, University of California-Davis, Sacramento, CA 95817 (United States); Tancredi, Daniel J., E-mail: djtancredi@ucdavis.edu [Department of Pediatrics, School of Medicine, University of California-Davis Medical Center, Sacramento, CA 95817 (United States); Rogawski, Michael A., E-mail: rogawski@ucdavis.edu [Department of Neurology, School of Medicine, University of California-Davis, Sacramento, CA 95817 (United States); Hammock, Bruce D., E-mail: bdhammock@ucdavis.edu [Department of Entomology, College of Agricultural and Environmental Sciences, University of California-Davis, Davis, CA 95616 (United States); Lein, Pamela J., E-mail: pjlein@ucdavis.edu [Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616 (United States)

    2014-12-01

    Tetramethylenedisulfotetramine (TETS) is a potent convulsant poison for which there is currently no approved antidote. The convulsant action of TETS is thought to be mediated by inhibition of type A gamma-aminobutyric acid receptor (GABA{sub A}R) function. We, therefore, investigated the effects of post-exposure administration of diazepam, a GABA{sub A}R positive allosteric modulator, on seizure activity, death and neuroinflammation in adult male Swiss mice injected with a lethal dose of TETS (0.15 mg/kg, ip). Administration of a high dose of diazepam (5 mg/kg, ip) immediately following the second clonic seizure (approximately 20 min post-TETS injection) effectively prevented progression to tonic seizures and death. However, this treatment did not prevent persistent reactive astrogliosis and microglial activation, as determined by GFAP and Iba-1 immunoreactivity and microglial cell morphology. Inhibition of soluble epoxide hydrolase (sEH) has been shown to exert potent anti-inflammatory effects and to increase survival in mice intoxicated with other GABA{sub A}R antagonists. The sEH inhibitor TUPS (1 mg/kg, ip) administered immediately after the second clonic seizure did not protect TETS-intoxicated animals from tonic seizures or death. Combined administration of diazepam (5 mg/kg, ip) and TUPS (1 mg/kg, ip, starting 1 h after diazepam and repeated every 24 h) prevented TETS-induced lethality and influenced signs of neuroinflammation in some brain regions. Significantly decreased microglial activation and enhanced reactive astrogliosis were observed in the hippocampus, with no changes in the cortex. Combining an agent that targets specific anti-inflammatory mechanisms with a traditional antiseizure drug may enhance treatment outcome in TETS intoxication. - Highlights: • Acute TETS intoxication causes delayed and persistent neuroinflammation. • Diazepam given post-TETS prevents lethal tonic seizures but not neuroinflammation. • A soluble epoxide hydrolase

  4. Combining in vitro and in silico methods for better prediction of surfactant effects on the absorption of poorly water soluble drugs-a fenofibrate case example.

    Science.gov (United States)

    Berthelsen, Ragna; Sjögren, Erik; Jacobsen, Jette; Kristensen, Jakob; Holm, René; Abrahamsson, Bertil; Müllertz, Anette

    2014-10-01

    The aim of this study was to develop a sensitive and discriminative in vitro-in silico model able to simulate the in vivo performance of three fenofibrate immediate release formulations containing different surfactants. In addition, the study was designed to investigate the effect of dissolution volume when predicting the oral bioavailability of the formulations. In vitro dissolution studies were carried out using the USP apparatus 2 or a mini paddle assembly, containing 1000 mL or 100mL fasted state biorelevant medium, respectively. In silico simulations of small intestinal absorption were performed using the GI-Sim absorption model. All simulation runs were performed twice adopting either a total small intestinal volume of 533 mL or 105 mL, in order to examine the implication of free luminal water volumes for the in silico predictions. For the tested formulations, the use of a small biorelevant dissolution volume was critical for in vitro-in silico prediction of drug absorption. Good predictions, demonstrating rank order in vivo-in vitro-in silico correlations for Cmax, were obtained with in silico predictions utilizing a 105 mL estimate for the human intestinal water content combined with solubility and dissolution data performed in a mini paddle apparatus with 100mL fasted state simulated media. Copyright © 2014. Published by Elsevier B.V.

  5. Theoretical Characterization of the Spectral Density of the Water-Soluble Chlorophyll-Binding Protein from Combined Quantum Mechanics/Molecular Mechanics Molecular Dynamics Simulations.

    Science.gov (United States)

    Rosnik, Andreana M; Curutchet, Carles

    2015-12-08

    Over the past decade, both experimentalists and theorists have worked to develop methods to describe pigment-protein coupling in photosynthetic light-harvesting complexes in order to understand the molecular basis of quantum coherence effects observed in photosynthesis. Here we present an improved strategy based on the combination of quantum mechanics/molecular mechanics (QM/MM) molecular dynamics (MD) simulations and excited-state calculations to predict the spectral density of electronic-vibrational coupling. We study the water-soluble chlorophyll-binding protein (WSCP) reconstituted with Chl a or Chl b pigments as the system of interest and compare our work with data obtained by Pieper and co-workers from differential fluorescence line-narrowing spectra (Pieper et al. J. Phys. Chem. B 2011, 115 (14), 4042-4052). Our results demonstrate that the use of QM/MM MD simulations where the nuclear positions are still propagated at the classical level leads to a striking improvement of the predicted spectral densities in the middle- and high-frequency regions, where they nearly reach quantitative accuracy. This demonstrates that the so-called "geometry mismatch" problem related to the use of low-quality structures in QM calculations, not the quantum features of pigments high-frequency motions, causes the failure of previous studies relying on similar protocols. Thus, this work paves the way toward quantitative predictions of pigment-protein coupling and the comprehension of quantum coherence effects in photosynthesis.

  6. Effects of metal ions on entero-soluble poly(methacrylic acid-methyl methacrylate) coating: a combined analysis by ATR-FTIR spectroscopy and computational approaches.

    Science.gov (United States)

    Cilurzo, Francesco; Gennari, Chiara G M; Selmin, Francesca; Vistoli, Giulio

    2010-04-05

    Poly(methacrylic acid-methyl methacrylate)s (HPMMs) are pH-dependent polymers which ionize and form salts (PMMs) in neutral conditions. Despite their wide use in tablet coating, the interactions of PMMs with electrolytes present in biorelevant media and luminal fluids have been scantly investigated. The data generated in the current work provide the basic information on the effect of bivalent cations, namely, Ca2+, Zn2+ and Mn2+, on the HPMMs' solubility and, consequently, on the performances (disintegration and drug dissolution) of acetaminophen gastroresistant tablets when exposed to fluid containing such salts. The interactions between polymers and metal ions were analyzed by ATR-FTIR spectroscopy and in silico combining molecular dynamics simulations to explore the conformational profiles of several oligomers with different M(w), taken as model of the polymers, with ab initio and semiempirical calculations in the gas phase. The computational results agree with the experimental data in terms of spatial disposition of the bications with respect to PMMs (Ca2+ and Mn2+ as bidentate form and Zn2+ as monodentate ligand) and interaction strength (Zn2+ > Mn(2+) > Ca2+). The tablet disintegration and dissolution rate of acetaminophen were strongly affected by the interactions of the dissolving copolymer with the metal ions which led to coating insolubilization. These preliminary results underline that the ingestion of metal ions at high concentrations could affect the drug liberation from gastroresistant dosage forms.

  7. Post-exposure administration of diazepam combined with soluble epoxide hydrolase inhibition stops seizures and modulates neuroinflammation in a murine model of acute TETS intoxication.

    Science.gov (United States)

    Vito, Stephen T; Austin, Adam T; Banks, Christopher N; Inceoglu, Bora; Bruun, Donald A; Zolkowska, Dorota; Tancredi, Daniel J; Rogawski, Michael A; Hammock, Bruce D; Lein, Pamela J

    2014-12-01

    Tetramethylenedisulfotetramine (TETS) is a potent convulsant poison for which there is currently no approved antidote. The convulsant action of TETS is thought to be mediated by inhibition of type A gamma-aminobutyric acid receptor (GABAAR) function. We, therefore, investigated the effects of post-exposure administration of diazepam, a GABAAR positive allosteric modulator, on seizure activity, death and neuroinflammation in adult male Swiss mice injected with a lethal dose of TETS (0.15mg/kg, ip). Administration of a high dose of diazepam (5mg/kg, ip) immediately following the second clonic seizure (approximately 20min post-TETS injection) effectively prevented progression to tonic seizures and death. However, this treatment did not prevent persistent reactive astrogliosis and microglial activation, as determined by GFAP and Iba-1 immunoreactivity and microglial cell morphology. Inhibition of soluble epoxide hydrolase (sEH) has been shown to exert potent anti-inflammatory effects and to increase survival in mice intoxicated with other GABAAR antagonists. The sEH inhibitor TUPS (1mg/kg, ip) administered immediately after the second clonic seizure did not protect TETS-intoxicated animals from tonic seizures or death. Combined administration of diazepam (5mg/kg, ip) and TUPS (1mg/kg, ip, starting 1h after diazepam and repeated every 24h) prevented TETS-induced lethality and influenced signs of neuroinflammation in some brain regions. Significantly decreased microglial activation and enhanced reactive astrogliosis were observed in the hippocampus, with no changes in the cortex. Combining an agent that targets specific anti-inflammatory mechanisms with a traditional antiseizure drug may enhance treatment outcome in TETS intoxication. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Kanamycin Sulphate Loaded PLGA-Vitamin-E-TPGS Long Circulating Nanoparticles Using Combined Coating of PEG and Water-Soluble Chitosan

    Directory of Open Access Journals (Sweden)

    Sanaul Mustafa

    2017-01-01

    Full Text Available Kanamycin sulphate (KS is a Mycobacterium tuberculosis protein synthesis inhibitor. Due to its intense hydrophilicity, KS is cleared from the body within 8 h. KS has a very short plasma half-life (2.5 h. KS is used in high concentrations to reach the therapeutic levels in plasma, which results in serious nephrotoxicity/ototoxicity. To overcome aforementioned limitations, the current study aimed to develop KS loaded PLGA-Vitamin-E-TPGS nanoparticles (KS-PLGA-TPGS NPs, to act as an efficient carrier for controlled delivery of KS. To achieve a substantial extension in blood circulation, a combined design, affixation of polyethylene glycol (PEG to KS-PLGA-TPGS NPs and adsorption of water-soluble chitosan (WSC (cationic deacetylated chitin to particle surface, was raised for surface modification of NPs. Surface modified NPs (KS-PEG-WSC NPs were prepared to provide controlled delivery and circulate in the bloodstream for an extended period of time, thus minimizing dosing frequency. In vivo pharmacokinetics and in vivo biodistribution following intramuscular administration were investigated. NPs surface charge was close to neutral +3.61 mV and significantly affected by the WSC coating. KS-PEG-WSC NPs presented striking prolongation in blood circulation, reduced protein binding, and long drew-out the blood circulation half-life with resultant reduced kidney sequestration vis-à-vis KS-PLGA-TPGS NPs. The studies, therefore, indicate the successful formulation development of KS-PEG-WSC NPs with reduced frequency of dosing of KS indicating low incidence of nephrotoxicity/ototoxicity.

  9. [Diagnostic value of combining serum soluble ST2 and interleukin-33 for heart failure patients with preserved left ventricular ejection fraction].

    Science.gov (United States)

    Luo, N S; Zhang, H F; Liu, P M; Lin, Y Q; Huang, T C; Yang, Y; Wang, J F

    2017-03-24

    Objective: Diagnostic efficacy of serum markers is low for heart failure patients with preserved left ventricular ejection fraction (HF-pEF) as compared to heart failure patients with reduced left ventricular ejection fraction.We sought to explore the diagnostic value of serum levels of soluble ST2 (sST2) combined with interleukin-33 (IL-33) for the diagnosis of HF-pEF in this study. Methods: A total of 376 patients with HF-pEF (HF group), 376 matched-control patients without heart failure who shared similar clinical characteristics (non-HF group) were included in the study.Another 500 healthy individuals were recruited for assessing the normal ranges of IL-33 and sST2.Serum levels of NT-proBNP were measured by chemi-luminescence assay, while IL-33 and sST2 were measured by enzyme linked immunosorbent assay. Results: Serum levels of IL-33 and sST2 were not normally distributed in healthy population.Serum concentrations of IL-33 and sST2 were significantly higher in HF-pEF patients than in patients in non-HF group (median, IL-33: 0.437 μg/L vs. 0.127 μg/L, P pEF was 0.763 (95% CI 0.729-0.795, P pEF was 0.83, with 74.73% sensitivity and 84.57% specificity.The AUC of sST2 for detecting HF-pEF was significantly higher than NT-proBNP in population with high serum IL-33 (AUC: 0.88 vs. 0.83, P pEF diagnosis, especially for patients with high serum IL-33 concentrations.

  10. Evaluation of phenylbutazone and poly(amidoamine) dendrimers interactions by a combination of solubility, 2D-NOESY NMR, and isothermal titration calorimetry studies.

    Science.gov (United States)

    Yang, Wenjun; Li, Yiwen; Cheng, Yiyun; Wu, Qinglin; Wen, Longping; Xu, Tongwen

    2009-03-01

    The interactions between phenylbutazone, a well-established nonsteroidal anti-inflammatory drug, with different generations of poly(amidoamine) (PAMAM) dendrimers, have been investigated by aqueous solubility, two dimensional nuclear Overhauser effect spectroscopy (2D-NOESY) and isothermal titration calorimetry (ITC) studies. Solubility results showed that PAMAM dendrimers significantly enhanced the aqueous solubility of phenylbutazone and the solubilization was much influenced by dendrimer concentration, generation, surface function group and pH value. The 2D-NOESY spectra clearly showed that there were several kinds of cross-peaks from NOE interactions between the protons of phenylbutazone and the protons in interior cavities of both generation 6 and generation 3 PAMAM dendrimers. The solubility, 2D-NOESY results and ITC analysis suggest that encapsulation and electrostatic interaction together caused the solubility enhancement of phenylbutazone. The new techniques such as 2D-NOESY and ITC used in this study are useful tools in investigating the interactions between dendrimers and guest molecules. (c) 2008 Wiley-Liss, Inc. and the American Pharmacists Association

  11. Assessment of the combined approach of N-alkylation and salt formation to enhance aqueous solubility of tertiary amines using bupivacaine as a model drug

    DEFF Research Database (Denmark)

    Nielsen, Anders Bach; Frydenvang, Karla Andrea; Liljefors, Tommy

    2005-01-01

    investigated using bupivacaine as a model compound. X-ray structure analyses of selected salts were included to investigate the potential existence of correlations between salt solubility and crystal packing modes. Alkyl groups were methyl, ethyl, propyl, and butyl and the derivatives were isolated...... as their iodide salts. Chloride, mesylate, formate, acetate, glycolate, and tosylate salts were obtained by anion exchange of the N-methyl-bupivacaine derivative. N-Alkylation and salt formation afforded quaternary ammonium salts possessing pH-independent aqueous solubilities far exceeding that of the parent...

  12. Soluble vs. insoluble fiber

    Science.gov (United States)

    Insoluble vs. soluble fiber; Fiber - soluble vs. insoluble ... There are 2 different types of fiber -- soluble and insoluble. Both are important for health, digestion, and preventing diseases. Soluble fiber attracts water and turns to gel during digestion. This slows ...

  13. Use of plasma C-reactive protein, procalcitonin, neutrophils, macrophage migration inhibitory factor, soluble urokinase-type plasminogen activator receptor, and soluble triggering receptor expressed on myeloid cells-1 in combination to diagnose infections: a prospective study

    DEFF Research Database (Denmark)

    Kofoed, Kristian; Andersen, Ove; Kronborg, Gitte

    2007-01-01

    Accurate and timely diagnosis of community-acquired bacterial infections in patients with systemic inflammation remains challenging both for clinician and laboratory. Combinations of markers, as opposed to single ones, may improve diagnosis and thereby survival. We therefore compared the diagnost...

  14. Spatial, temporal and functional molecular architecture of the munc18-syntaxin interaction

    OpenAIRE

    Smyth, Annya Mary

    2012-01-01

    Regulation of soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptors (SNARE) mediated exocytosis is dependent upon four key proteins; the vesicular SNARE synaptobrevin, target SNAREs SNAP-25 and syntaxin and the Sec1/Munc18 (SM) protein munc18-1. Despite the munc18-1-syntaxin interaction being central to regulated vesicle exocytosis the spatial and temporal pattern of their molecular distribution and interaction in neuroendocrine and neuronal cells remai...

  15. Munc18-1 and Munc18-2 Proteins Modulate beta-Cell Ca2+ Sensitivity and Kinetics of Insulin Exocytosis Differently

    OpenAIRE

    Mandic, Slavena A.; Skelin, Masa; Johansson, Jenny U.; Rupnik, Marjan S.; Berggren, Per-Olof; Bark, Christina

    2011-01-01

    Fast neurotransmission and slower hormone release share the same core fusion machinery consisting of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins. In evoked neurotransmission, interactions between SNAREs and the Munc18-1 protein, a member of the Sec1/Munc18 (SM) protein family, are essential for exocytosis, whereas other SM proteins are dispensable. To address if the exclusivity of Munc18-1 demonstrated in neuroexocytosis also applied to fast insulin ...

  16. [Near-infrared spectra combining with CARS and SPA algorithms to screen the variables and samples for quantitatively determining the soluble solids content in strawberry].

    Science.gov (United States)

    Li, Jiang-bo; Guo, Zhi-ming; Huang, Wen-qian; Zhang, Bao-hua; Zhao, Chun-jiang

    2015-02-01

    In using spectroscopy to quantitatively or qualitatively analyze the quality of fruit, how to obtain a simple and effective correction model is very critical for the application and maintenance of the developed model. Strawberry as the research object, this research mainly focused on selecting the key variables and characteristic samples for quantitatively determining the soluble solids content. Competitive adaptive reweighted sampling (CARS) algorithm was firstly proposed to select the spectra variables. Then, Samples of correction set were selected by successive projections algorithm (SPA), and 98 characteristic samples were obtained. Next, based on the selected variables and characteristic samples, the second variable selection was performed by using SPA method. 25 key variables were obtained. In order to verify the performance of the proposed CARS algorithm, variable selection algorithms including Monte Carlo-uninformative variable elimination (MC-UVE) and SPA were used as the comparison algorithms. Results showed that CARS algorithm could eliminate uninformative variables and remove the collinearity information at the same time. Similarly, in order to assess the performance of the proposed SPA algorithm for selecting the characteristic samples, SPA algorithm was compared with classical Kennard-Stone algorithm Results showed that SPA algorithm could be used for selection of the characteristic samples in the calibration set. Finally, PLS and MLR model for quantitatively predicting the SSC (soluble solids content) in the strawberry were proposed based on the variables/samples subset (25/98), respectively. Results show that models built by using the 0.59% and 65.33% information of original variables and samples could obtain better performance than using the ones obtained by using all information of the original variables and samples. MLR model was the best with R(pre)2 = 0.9097, RMSEP=0.3484 and RPD = 3.3278.

  17. Evaluation of Matrix Tablets Based on Eudragit®E100/Carbopol®971P Combinations for Controlled Release and Improved Compaction Properties of Water Soluble Model Drug Paracetamol.

    Science.gov (United States)

    Obeidat, Wasfy M; Nokhodchi, Ali; Alkhatib, Hatim

    2015-10-01

    The purpose of this work was to investigate the influence of Eudragit®E100 polymer in modifying the release rates and compaction properties of water soluble model drug paracetamol from Carbopol®971P NF polymer matrix tablets prepared by direct compression. The effects of the ratio of the two polymers, the total polymeric content, and the tablets mechanical strength on paracetamol release rates were investigated. Dissolution studies were conducted using USP XX Π rotating paddle apparatus at 50 rpm and 37°C at three different stages (pH 1.2, 4.8, and 6.8). Results showed that the polymers combination improved significantly the compaction properties of paracetamol tablets as evident by the higher crushing strengths (8.3 ± 0.4 Kp) compared to polymer-free tablets (3.4 ± 0.2 Kp) at intermediate compression pressure of 490 MPa. When combined with Carbopol®971P NF, Eudragit®E100 was found to be capable of extending paracetamol release for more than 12 h compared to 1 h for polymers-free tablets. The combined polymers were able to control paracetamol release in a pH independent pattern. The f2 (similarity factor) analysis showed that the ratio between the polymers and the total polymer concentration exhibited significant impact on drug release rates. In conclusion, Eudragit®E100 when combined with Carbopol®971P NF was capable of improving the compaction and sustained release properties of paracetamol. Korsmeyer-Peppas model was found to be the most suitable for fitting drug release data. The polymer combinations can potentially be used to control the release rates of highly water soluble drugs.

  18. A pilot study of brisk walking in sedentary combination antiretroviral treatement (cART)- treated patients: benefit on soluble and cell inflammatory markers.

    Science.gov (United States)

    Bonato, Matteo; Galli, Laura; Passeri, Laura; Longo, Valeria; Pavei, Gaspare; Bossolasco, Simona; Bertocchi, Cecilia; Cernuschi, Massimo; Balconi, Giuseppe; Merati, Giampiero; Lazzarin, Adriano; La Torre, Antonio; Cinque, Paola

    2017-01-11

    Chronic HIV infection is associated with low-level inflammation and increased risk of chronic diseases and mortality. The objective was to assess the effects of moderate intensity exercise on metabolic and inflammatory markers in HIV-infected treated persons. This was a pilot study enrolling cART-treated, sedentary persons with metabolic complications in a 12-week protocol, consisting of three sessions per week of 60 min brisk walking with (strength-walk group) or without (walk group) 30 min circuit-training. Assessments at baseline and week 12 (W12) included body morphometrics and total body dual-energy X-ray absorptiometry; lipid and glucose blood profile; plasma level of high sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), D-dimer, interleukin-18 (IL-18), soluble CD14, and CD38 and HLA-DR expression on CD4+ and CD8+ T-cells. Forty-nine patients were included and 35 (71%) completed the program: 21 in the walk and 14 in the strength-walk group. At W12, significant improvements were observed of body mass index, waist and hip circumference, and total cholesterol both overall and in the walk group, and of LDL cholesterol in both training groups. In the whole group, significant reductions were observed in hsCRP, IL-6, D-dimer, IL-18, and of CD8+/CD38+/HLA-DR+ cell frequencies. HsCRP and CD8+/CD38+/HLA-DR+ frequency decreased significantly in both training groups when examined separately whereas IL-6 and D-dimer in the walk group only. Brisk walking, with or without strength exercise, could improve lipid profile and inflammatory markers in chronic HIV infection. ACTRN12615001258549, registered 17 November 2015, "retrospectively registered" Web address of trial: http://www.ANZCTR.org.au/ACTRN12615001258549.aspx.

  19. Soluble semiconductors AAsSe2 (A = Li, Na) with a direct-band-gap and strong second harmonic generation: a combined experimental and theoretical study.

    Science.gov (United States)

    Bera, Tarun K; Jang, Joon I; Song, Jung-Hwan; Malliakas, Christos D; Freeman, Arthur J; Ketterson, John B; Kanatzidis, Mercouri G

    2010-03-17

    AAsSe(2) (A = Li, Na) have been identified as a new class of polar direct-band gap semiconductors. These I-V-VI(2) ternary alkali-metal chalcoarsenates have infinite single chains of (1/infinity)[AsQ(2)(-)] derived from corner-sharing pyramidal AsQ(3) units with stereochemically active lone pairs of electrons on arsenic. The conformations and packing of the chains depend on the structure-directing alkali metals. This results in at least four different structural types for the Li(1-x)Na(x)AsSe(2) stoichiometry (alpha-LiAsSe(2), beta-LiAsSe(2), gamma-NaAsSe(2), and delta-NaAsSe(2)). Single-crystal X-ray diffraction studies showed an average cubic NaCl-type structure for alpha-LiAsSe(2), which was further demonstrated to be locally distorted by pair distribution function (PDF) analysis. The beta and gamma forms have polar structures built of different (1/infinity)[AsSe(2)(-)] chain conformations, whereas the delta form has nonpolar packing. A wide range of direct band gaps are observed, depending on composition: namely, 1.11 eV for alpha-LiAsSe(2), 1.60 eV for LiAsS(2), 1.75 eV for gamma-NaAsSe(2), 2.23 eV for NaAsS(2). The AAsQ(2) materials are soluble in common solvents such as methanol, which makes them promising candidates for solution processing. Band structure calculations performed with the highly precise screened-exchange sX-LDA FLAPW method confirm the direct-gap nature and agree well with experiment. The polar gamma-NaAsSe(2) shows very large nonlinear optical (NLO) second harmonic generation (SHG) response in the wavelength range of 600-950 nm. The theoretical studies confirm the experimental results and show that gamma-NaAsSe(2) has the highest static SHG coefficient known to date, 337.9 pm/V, among materials with band gaps larger than 1.0 eV.

  20. A Combined Study Investigating the Insoluble and Soluble Organic Compounds in Category 3 Carbonaceous Itokawa Particles Recovered by the Hayabusa Mission

    Science.gov (United States)

    Chan, Q. H. S.; Zolensky, M.; Burton, A.; Clemett, S.; Fries, M.; Kebukawa, Y.

    2015-01-01

    At the 3rd International Announcement of Opportunity (AO), we have been approved for five Category 3 carbonaceous Itokawa particles (RA-QD02-0012, RA-QD02-0078, RB-CV-0029, RB-CV-0080 and RB-QD04-0052) recovered by the first Hayabusa mission of JAXA. In this investigation, we aim to provide a comprehensive study to characterize and account for the presence of carbon-bearing phases as suggested by the initial Scanning Electron Microscopy (SEM) analysis carried out by JAXA at the curation facility, and to describe the mineralogical components of the particles. The insoluble organic content of Itokawa particle has been investigated with the use of micro-Raman spectroscopy by Kitajima and co-workers [1]. The Raman spectra of Itokawa particles show broad G- and D-bands typical of low temperature material which offers an interesting contrast to the high metamorphic grade (LL4-6) of the Itokawa parent body. Amino acid analysis has been conducted by Naraoka et al. [2] to study the soluble organic component of Itokawa particles, but since it was a preliminary study and thus did not have the opportunity to target on Category 3 carbonaceous particles, only terrestrial contaminants were identified. The investigation will be carried out in the following order prioritized according to the progressive damage the analytical techniques can induce: (1) micro-Raman spectrometry, (2) two-step laser mass spectrometry (micro-L2MS), (3) ultra-high performance liquid chromatography with fluorescence detection and time-of-flight mass spectrometry (LC-FD/ToF-MS), and optimally if we can recover the particles after wet chemistry analysis, we will mount the samples and perform (4) electron beam microscopy (SEM, electron back-scattered diffraction [EBSD]) and (5) carbon X-ray absorption near edge structure spectroscopy (C-XANES). We will begin the analytical procedures upon receiving the samples in September/October. This work will provide us with an understanding of the variety and origins of

  1. Gas solubilities widespread applications

    CERN Document Server

    Gerrard, William

    1980-01-01

    Gas Solubilities: Widespread Applications discusses several topics concerning the various applications of gas solubilities. The first chapter of the book reviews Henr's law, while the second chapter covers the effect of temperature on gas solubility. The third chapter discusses the various gases used by Horiuti, and the following chapters evaluate the data on sulfur dioxide, chlorine data, and solubility data for hydrogen sulfide. Chapter 7 concerns itself with solubility of radon, thoron, and actinon. Chapter 8 tackles the solubilities of diborane and the gaseous hydrides of groups IV, V, and

  2. Enhanced suppression of adenovirus replication by triple combination of anti-adenoviral siRNAs, soluble adenovirus receptor trap sCAR-Fc and cidofovir.

    Science.gov (United States)

    Pozzuto, Tanja; Röger, Carsten; Kurreck, Jens; Fechner, Henry

    2015-08-01

    Adenoviruses (Ad) generally induce mild self-limiting respiratory or intestinal infections but can also cause serious disease with fatal outcomes in immunosuppressed patients. Antiviral drug therapy is an important treatment for adenoviral infections but its efficiency is limited. Recently, we have shown that gene silencing by RNA interference (RNAi) is a promising new approach to inhibit adenoviral infection. In the present in vitro study, we examined whether the efficiency of an RNAi-based anti-adenoviral therapy can be further increased by combination with a virus receptor trap sCAR-Fc and with the antiviral drug cidofovir. Initially, three siRNAs, siE1A_4, siIVa2_2 and Pol-si2, targeting the adenoviral E1A, IVa2 and DNA polymerase mRNAs, respectively, were used for gene silencing. Replication of the Ad was inhibited in a dose dependent manner by each siRNA, but the efficiency of inhibition differed (Pol-si2>siIVa2_2>siE1A_4). Double or triple combinations of the siRNAs compared with single siRNAs did not result in a measurably higher suppression of Ad replication. Combination of the siRNAs (alone or mixes of two or three siRNAs) with sCAR-Fc markedly increased the suppression of adenoviral replication compared to the same siRNA treatment without sCAR-Fc. Moreover, the triple combination of a mix of all three siRNAs, sCAR-Fc and cidofovir was about 23-fold more efficient than the combination of siRNAs mix/sCAR-Fc and about 95-fold more efficient than the siRNA mix alone. These data demonstrate that co-treatment of cells with sCAR-Fc and cidofovir is suitable to increase the efficiency of anti-adenoviral siRNAs. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Doping Induced Solubility Control

    Science.gov (United States)

    Jacobs, Ian Edward

    Polymeric semiconductors are promising class of materials, which combine many of the electrical properties of inorganic semiconductors with the mechanical flexibility and chemical processability of organic materials. Semiconducting polymers can be deposited from solution over large areas at low cost, and may find applications in displays, photovoltaics, and sensor arrays. Unfortunately, these materials are generally mutually soluble with other organics, preventing solution-based deposition of complex patterned structures using standard photolithographic techniques. Here, we present an entirely new method for patterning conductive polymers utilizing a change in polymer solubility upon p-type doping. Many polymer : molecular dopant systems, including the extensively studied system poly-(3-hexylthiophene) : 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (P3HT : F4TCNQ), are rendered insoluble in a wide range solvents by p-type doping at only a few mol%. By sequentially doping and dedoping films, polymer solubility can be switched on an off at will. We find that doped films can be easily prepared in a two-step process, by first coating the polymer (P3HT), then exposing the film to an orthogonal solvent containing the dopant (F4TCNQ). Dedoping is achieved by means of a chemical reaction that deactivates F4TCNQ, allowing it to be removed by an orthogonal solvent in a single step. This process allows for fully quantitative dedoping, in some cases leaving films with an even lower free carrier density than as cast films by removing intrinsic p-type defects. In addition, we have also identified a photochemical reaction between F4TCNQ and solvents such as tetrahydrofuran (THF), which similarly yields a non-doping product. By immersing films in THF and exposing them to light, this reaction allows for direct, optical patterning of P3HT films. Using laser scanning confocal microscopy (LSCM), we demonstrate direct write topographic patterning of arbitrary structures with in

  4. A library of 7TM receptor C-terminal tails. Interactions with the proposed post-endocytic sorting proteins ERM-binding phosphoprotein 50 (EBP50), N-ethylmaleimide-sensitive factor (NSF), sorting nexin 1 (SNX1), and G protein-coupled receptor-associated sorting protein (GASP)

    DEFF Research Database (Denmark)

    Heydorn, Arne; Søndergaard, Birgitte P; Ersbøll, Bjarne

    2004-01-01

    Adaptor and scaffolding proteins determine the cellular targeting, the spatial, and thereby the functional association of G protein-coupled seven-transmembrane receptors with co-receptors, transducers, and downstream effectors and the adaptors determine post-signaling events such as receptor...... sequestration through interactions, mainly with the C-terminal intracellular tails of the receptors. A library of tails from 59 representative members of the super family of seven-transmembrane receptors was probed as glutathione S-transferase fusion proteins for interactions with four different adaptor...... that the tail library provides useful information on the general importance of certain adaptor proteins, for example, in this case, ruling out EBP50 as being a broad spectrum-recycling adaptor....

  5. Exposure of Atlantic salmon parr (Salmo salar) to a combination of resin acids and a water soluble fraction of diesel fuel oil: A model to investigate the chemical causes of pigmented salmon syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Croce, B. [Scottish Office Agriculture, Environment, and Fisheries Dept., Aberdeen (United Kingdom). Marine Lab.]|[Scottish Environmental Protection Agency, Aberdeen (United Kingdom). North East River Purification Board; Stagg, R.M. [Scottish Office Agriculture, Environment, and Fisheries Dept., Aberdeen (United Kingdom). Marine Lab.

    1997-09-01

    Pigmented salmon syndrome is a pollutant-induced hemolytic anemia and hyperbilirubinemia. As part of an investigation of this condition, S2 Atlantic salmon parr (Salmo salar) were exposed to a diesel fuel oil, water soluble fraction (WSF) in combination with a mixture of three resin acids (isopimaric, dehydroabietic, and abietic acids) in a continuous-flow freshwater system. The total nominal concentrations of resin acids in the exposure tanks were 10, 50, and 100 {micro}g/L; the diesel WSF was generated in situ and provided a mean hydrocarbon concentration of 2.0 {+-} 0.1 mg/L (n = 12) during the 9-d exposure period. Exposure to the diesel WSF alone depressed liver bilirubin UDP-glucuronosyl transferase (UDPGT) activity and induced phenol UDPGT activity. Exposure to the diesel WSF in the absence or presence of resin acids induced liver cytochrome P4501A and increased the concentrations in the plasma of the enzymes lactate dehydrogenase, alkaline phosphatase, and glutamic oxaloacetic transaminase. The combined exposure to diesel WSF with either 50 or 100 {micro}g/L total resin acid caused significant elevations in the concentrations of bilirubin in the plasma and many of these fish had yellow pigmentation on the ventral surface and around the gill arches. The results demonstrate that exposure to combinations of two groups of contaminants can result in the manifestation of toxic effects not apparent from exposure to either of these chemicals in isolation.

  6. Soluble insulin analogs combining rapid- and long-acting hypoglycemic properties – From an efficient E. coli expression system to a pharmaceutical formulation

    Science.gov (United States)

    Mikiewicz, Diana; Bierczyńska-Krzysik, Anna; Sobolewska, Agnieszka; Stadnik, Dorota; Bogiel, Monika; Pawłowska, Monika; Wójtowicz-Krawiec, Anna; Baran, Piotr A.; Łukasiewicz, Natalia; Romanik-Chruścielewska, Agnieszka; Sokołowska, Iwona; Stadnik, Jacek; Borowicz, Piotr; Płucienniczak, Grażyna; Płucienniczak, Andrzej

    2017-01-01

    The discovery of insulin led to a revolution in diabetes management. Since then, many improvements have been introduced to insulin preparations. The availability of molecular genetic techniques has enabled the creation of insulin analogs by changing the structure of the native protein in order to improve the therapeutic properties. A new expression vector pIBAINS for production of four recombinant human insulin (INS) analogs (GKR, GEKR, AKR, SR) was constructed and overexpressed in the new E. coli 20 strain as a fusion protein with modified human superoxide dismutase (SOD). The SOD gene was used as a signal peptide to enhance the expression of insulin. SOD::INS was manufactured in the form of insoluble inclusion bodies. After cleavage of the fusion protein with trypsin, the released insulin analogs were refolded and purified by reverse-phase high performance liquid chromatography (RP-HPLC). Elongation of chain A, described here for the first time, considerably improved the stability of the selected analogs. Their identity was confirmed with mass spectrometric techniques. The biological activity of the insulin derivatives was tested on rats with experimental diabetes. The obtained results proved that the new analogs described in this paper have the potential to generate prolonged hypoglycemic activity and may allow for even less frequent subcutaneous administration than once-a-day. When applied, all the analogs demonstrate a rapid onset of action. Such a combination renders the proposed biosynthetic insulin unique among already known related formulations. PMID:28296883

  7. Soluble insulin analogs combining rapid- and long-acting hypoglycemic properties - From an efficient E. coli expression system to a pharmaceutical formulation.

    Science.gov (United States)

    Mikiewicz, Diana; Bierczyńska-Krzysik, Anna; Sobolewska, Agnieszka; Stadnik, Dorota; Bogiel, Monika; Pawłowska, Monika; Wójtowicz-Krawiec, Anna; Baran, Piotr A; Łukasiewicz, Natalia; Romanik-Chruścielewska, Agnieszka; Sokołowska, Iwona; Stadnik, Jacek; Borowicz, Piotr; Płucienniczak, Grażyna; Płucienniczak, Andrzej

    2017-01-01

    The discovery of insulin led to a revolution in diabetes management. Since then, many improvements have been introduced to insulin preparations. The availability of molecular genetic techniques has enabled the creation of insulin analogs by changing the structure of the native protein in order to improve the therapeutic properties. A new expression vector pIBAINS for production of four recombinant human insulin (INS) analogs (GKR, GEKR, AKR, SR) was constructed and overexpressed in the new E. coli 20 strain as a fusion protein with modified human superoxide dismutase (SOD). The SOD gene was used as a signal peptide to enhance the expression of insulin. SOD::INS was manufactured in the form of insoluble inclusion bodies. After cleavage of the fusion protein with trypsin, the released insulin analogs were refolded and purified by reverse-phase high performance liquid chromatography (RP-HPLC). Elongation of chain A, described here for the first time, considerably improved the stability of the selected analogs. Their identity was confirmed with mass spectrometric techniques. The biological activity of the insulin derivatives was tested on rats with experimental diabetes. The obtained results proved that the new analogs described in this paper have the potential to generate prolonged hypoglycemic activity and may allow for even less frequent subcutaneous administration than once-a-day. When applied, all the analogs demonstrate a rapid onset of action. Such a combination renders the proposed biosynthetic insulin unique among already known related formulations.

  8. Amyloid Fibril Solubility.

    Science.gov (United States)

    Rizzi, L G; Auer, S

    2015-11-19

    It is well established that amyloid fibril solubility is protein specific, but how solubility depends on the interactions between the fibril building blocks is not clear. Here we use a simple protein model and perform Monte Carlo simulations to directly measure the solubility of amyloid fibrils as a function of the interaction between the fibril building blocks. Our simulations confirms that the fibril solubility depends on the fibril thickness and that the relationship between the interactions and the solubility can be described by a simple analytical formula. The results presented in this study reveal general rules how side-chain-side-chain interactions, backbone hydrogen bonding, and temperature affect amyloid fibril solubility, which might prove to be a powerful tool to design protein fibrils with desired solubility and aggregation properties in general.

  9. Low Dose Total Body Irradiation Combined With Recombinant CD19-Ligand × Soluble TRAIL Fusion Protein is Highly Effective Against Radiation-resistant B-precursor Acute Lymphoblastic Leukemia in Mice

    Directory of Open Access Journals (Sweden)

    Fatih M. Uckun

    2015-04-01

    Full Text Available In high-risk remission B-precursor acute lymphoblastic leukemia (BPL patients, relapse rates have remained high post-hematopoietic stem cell transplantation (HSCT even after the use of very intensive total body irradiation (TBI-based conditioning regimens, especially in patients with a high “minimal residual disease” (MRD burden. New agents capable of killing radiation-resistant BPL cells and selectively augmenting their radiation sensitivity are therefore urgently needed. We report preclinical proof-of-principle that the potency of radiation therapy against BPL can be augmented by combining radiation with recombinant human CD19-Ligand × soluble TRAIL (“CD19L–sTRAIL” fusion protein. CD19L–sTRAIL consistently killed radiation-resistant primary leukemia cells from BPL patients as well as BPL xenograft cells and their leukemia-initiating in vivo clonogenic fraction. Low dose total body irradiation (TBI combined with CD19L–sTRAIL was highly effective against (1 xenografted CD19+ radiochemotherapy-resistant human BPL in NOD/SCID (NS mice challenged with an otherwise invariably fatal dose of xenograft cells derived from relapsed BPL patients as well as (2 radiation-resistant advanced stage CD19+ murine BPL with lymphomatous features in CD22ΔE12xBCR-ABL double transgenic mice. We hypothesize that the incorporation of CD19L–sTRAIL into the pre-transplant TBI regimens of patients with very high-risk BPL will improve their survival outcome after HSCT.

  10. Applications of Solubility Data

    Science.gov (United States)

    Tomkins, Reginald P. T.

    2008-01-01

    This article describes several applications of the use of solubility data. It is not meant to be exhaustive but rather to show that knowledge of solubility data is required in a variety of technical applications that assist in the design of chemical processes. (Contains 3 figures and 1 table.)

  11. The Solubility of struvite

    DEFF Research Database (Denmark)

    Aage, H. K.; Andersen, Bertel Lohmann; Blom, A.

    1997-01-01

    The solubility of magnesium-amonium-phosphate (struvite) has been studied emloying the radioisotope 32P as tracer. The amount of sample in solution is determined by measuring the Cherenkov radiation due to the beta-particles emitted from this radionuclide. The thermodynamic solubility product...

  12. What Variables Affect Solubility?

    Science.gov (United States)

    Baker, William P.; Leyva, Kathryn

    2003-01-01

    Helps middle school students understand the concept of solubility through hands-on experience with a variety of liquids and solids. As they explore factors that affect solubility and saturation, students gain content mastery and an understanding of the inquiry process. Also enables teachers to authentically assess student performance on several…

  13. Soluble oil flooding

    Energy Technology Data Exchange (ETDEWEB)

    Holm, L.W.; Knight, R.K.

    1976-11-01

    A soluble oil-polymer flooding process used in previously waterflooded reservoirs utilizes oleic, micellar solutions which, when injected as small slugs and driven by polymer thickened water, are capable of displacing all oil and water contacted. During the micellar flood, oil and water are displaced from reservoir rock by one or more of the following mechanisms: (1) miscible-type displacement of oil by soluble oil; (2) miscible-type displacement of resident water by injection water and soluble oil; (3) formation of microemulsions by the intermingling of soluble oil and injected water; and (4) reduction of interfacial tension between oil and water phases where both are present. The Higgs Unit, site of a field test of soluble oil flooding, is a small pool in the Jones County Regular field near Abilene, Tex. Field data, special equipment, test evaluation, and field test conclusions are given for this operation.

  14. Replacing SNAP-25b with SNAP-25a expression results in metabolic disease.

    Science.gov (United States)

    Valladolid-Acebes, Ismael; Daraio, Teresa; Brismar, Kerstin; Harkany, Tibor; Ögren, Sven Ove; Hökfelt, Tomas G M; Bark, Christina

    2015-08-04

    Synaptosomal-associated protein of 25 kDa (SNAP-25) is a key molecule in the soluble N-ethylmaleimide-sensitive factor attachment protein (SNARE) complex mediating fast Ca(2+)-triggered release of hormones and neurotransmitters, and both splice variants, SNAP-25a and SNAP-25b, can participate in this process. Here we explore the hypothesis that minor alterations in the machinery mediating regulated membrane fusion can increase the susceptibility for metabolic disease and precede obesity and type 2 diabetes. Thus, we used a mouse mutant engineered to express normal levels of SNAP-25 but only SNAP-25a. These SNAP-25b-deficient mice were exposed to either a control or a high-fat/high-sucrose diet. Monitoring of food intake, body weight, hypothalamic function, and lipid and glucose homeostases showed that SNAP-25b-deficient mice fed with control diet developed hyperglycemia, liver steatosis, and adipocyte hypertrophy, conditions dramatically exacerbated when combined with the high-fat/high-sucrose diet. Thus, modified SNARE function regulating stimulus-dependent exocytosis can increase the vulnerability to and even provoke metabolic disease. When combined with a high-fat/high-sucrose diet, this vulnerability resulted in diabesity. Our SNAP-25b-deficient mouse may represent a diabesity model.

  15. Proteomic analysis of cellular soluble proteins from human bronchial smooth muscle cells by combining nondenaturing micro 2DE and quantitative LC-MS/MS. 2. Similarity search between protein maps for the analysis of protein complexes.

    Science.gov (United States)

    Jin, Ya; Yuan, Qi; Zhang, Jun; Manabe, Takashi; Tan, Wen

    2015-09-01

    Human bronchial smooth muscle cell soluble proteins were analyzed by a combined method of nondenaturing micro 2DE, grid gel-cutting, and quantitative LC-MS/MS and a native protein map was prepared for each of the identified 4323 proteins [1]. A method to evaluate the degree of similarity between the protein maps was developed since we expected the proteins comprising a protein complex would be separated together under nondenaturing conditions. The following procedure was employed using Excel macros; (i) maps that have three or more squares with protein quantity data were selected (2328 maps), (ii) within each map, the quantity values of the squares were normalized setting the highest value to be 1.0, (iii) in comparing a map with another map, the smaller normalized quantity in two corresponding squares was taken and summed throughout the map to give an "overlap score," (iv) each map was compared against all the 2328 maps and the largest overlap score, obtained when a map was compared with itself, was set to be 1.0 thus providing 2328 "overlap factors," (v) step (iv) was repeated for all maps providing 2328 × 2328 matrix of overlap factors. From the matrix, protein pairs that showed overlap factors above 0.65 from both protein sides were selected (431 protein pairs). Each protein pair was searched in a database (UniProtKB) on complex formation and 301 protein pairs, which comprise 35 protein complexes, were found to be documented. These results demonstrated that native protein maps and their similarity search would enable simultaneous analysis of multiple protein complexes in cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Proteomic analysis of cellular soluble proteins from human bronchial smooth muscle cells by combining nondenaturing micro 2DE and quantitative LC‐MS/MS. 2. Similarity search between protein maps for the analysis of protein complexes

    Science.gov (United States)

    Jin, Ya; Yuan, Qi; Zhang, Jun; Manabe, Takashi

    2015-01-01

    Human bronchial smooth muscle cell soluble proteins were analyzed by a combined method of nondenaturing micro 2DE, grid gel‐cutting, and quantitative LC‐MS/MS and a native protein map was prepared for each of the identified 4323 proteins [1]. A method to evaluate the degree of similarity between the protein maps was developed since we expected the proteins comprising a protein complex would be separated together under nondenaturing conditions. The following procedure was employed using Excel macros; (i) maps that have three or more squares with protein quantity data were selected (2328 maps), (ii) within each map, the quantity values of the squares were normalized setting the highest value to be 1.0, (iii) in comparing a map with another map, the smaller normalized quantity in two corresponding squares was taken and summed throughout the map to give an “overlap score,” (iv) each map was compared against all the 2328 maps and the largest overlap score, obtained when a map was compared with itself, was set to be 1.0 thus providing 2328 “overlap factors,” (v) step (iv) was repeated for all maps providing 2328 × 2328 matrix of overlap factors. From the matrix, protein pairs that showed overlap factors above 0.65 from both protein sides were selected (431 protein pairs). Each protein pair was searched in a database (UniProtKB) on complex formation and 301 protein pairs, which comprise 35 protein complexes, were found to be documented. These results demonstrated that native protein maps and their similarity search would enable simultaneous analysis of multiple protein complexes in cells. PMID:26031785

  17. Relevance of angiopoietin-2 and soluble P-selectin levels in patients with pulmonary arterial hypertension receiving combination therapy with oral treprostinil: a FREEDOM-C2 biomarker substudy

    Science.gov (United States)

    Schermuly, Ralph; Seeger, Werner; Rao, Youlan; Ghofrani, Hossein A.; Gall, Henning

    2016-01-01

    Abstract Studies have suggested roles for angiopoietin-2 (Ang-2) and soluble P-selectin (sP-selectin) as biomarkers of disease severity and treatment response in pulmonary arterial hypertension (PAH), but additional data are required for validation. We evaluated these biomarkers using data from FREEDOM-C2, in which patients with PAH receiving stable monotherapy or combination therapy were randomized to receive additional treatment with oral treprostinil (up-titrated from 0.25 mg twice daily) or placebo for 16 weeks. Biomarker analysis was optional in FREEDOM-C2. We measured plasma Ang-2 and sP-selectin levels at baseline and at week 16, and we assessed their association with predefined outcomes (6-minute walk distance [6MWD] change from baseline >40 m, 6MWD >380 m, functional class I/II, and/or N-terminal pro-brain natriuretic peptide [NT-proBNP] <1,800 pg/mL at week 16) using Spearman correlation, receiver operating characteristics, and logistic regression. Biomarker data were available for 83 of 157 and 95 of 153 patients in the oral treprostinil and placebo groups, respectively. In the oral treprostinil group, baseline Ang-2 levels correlated with week 16 NT-proBNP levels (P < 0.0001). Baseline Ang-2 ≥12 ng/mL was associated with a reduced likelihood of having NT-proBNP <1,800 pg/mL at week 16 (multivariate odds ratio: 0.08; 95% confidence interval: 0.02–0.32). However, Ang-2 showed no significant association with the other assessed outcomes, and sP-selectin was not associated or correlated with any of the outcomes. These data suggest that Ang-2 and sP-selectin are not associated with response to oral treprostinil in patients already receiving stable PAH therapy. Trial registration: Clinicaltrials.gov identifier NCT00887978. PMID:28090293

  18. Soluble and insoluble fiber (image)

    Science.gov (United States)

    ... stool. There are two types of dietary fiber, soluble and insoluble. Soluble fiber retains water and turns to gel during ... and nutrient absorption from the stomach and intestine. Soluble fiber is found in foods such as oat ...

  19. Learning about Solubility

    Science.gov (United States)

    Salinas, Dino G.; Reyes, Juan G.

    2015-01-01

    Qualitative questions are proposed to assess the understanding of solubility and some of its applications. To improve those results, a simple quantitative problem on the precipitation of proteins is proposed.

  20. Protein solubility modeling

    Science.gov (United States)

    Agena, S. M.; Pusey, M. L.; Bogle, I. D.

    1999-01-01

    A thermodynamic framework (UNIQUAC model with temperature dependent parameters) is applied to model the salt-induced protein crystallization equilibrium, i.e., protein solubility. The framework introduces a term for the solubility product describing protein transfer between the liquid and solid phase and a term for the solution behavior describing deviation from ideal solution. Protein solubility is modeled as a function of salt concentration and temperature for a four-component system consisting of a protein, pseudo solvent (water and buffer), cation, and anion (salt). Two different systems, lysozyme with sodium chloride and concanavalin A with ammonium sulfate, are investigated. Comparison of the modeled and experimental protein solubility data results in an average root mean square deviation of 5.8%, demonstrating that the model closely follows the experimental behavior. Model calculations and model parameters are reviewed to examine the model and protein crystallization process. Copyright 1999 John Wiley & Sons, Inc.

  1. Soluble CD163

    DEFF Research Database (Denmark)

    Parkner, Tina; Sørensen, L P; Nielsen, A R

    2012-01-01

    Soluble CD163 (sCD163) was recently identified as a strong risk marker for developing type 2 diabetes. We hypothesised that sCD163 independently associates with insulin resistance.......Soluble CD163 (sCD163) was recently identified as a strong risk marker for developing type 2 diabetes. We hypothesised that sCD163 independently associates with insulin resistance....

  2. Polyphenols differentially inhibit degranulation of distinct subsets of vesicles in mast cells by specific interaction with granule-type-dependent SNARE complexes

    Science.gov (United States)

    Yang, Yoosoo; Oh, Jung-Mi; Heo, Paul; Shin, Jae Yoon; Kong, Byoungjae; Shin, Jonghyeok; Lee, Ji-Chun; Oh, Jeong Su; Park, Kye Won; Lee, Choong Hwan; Shin, Yeon-Kyun; Kweon, Dae-Hyuk

    2016-01-01

    Anti-allergic effects of dietary polyphenols were extensively studied in numerous allergic disease models, but the molecular mechanisms of anti-allergic effects by polyphenols remain poorly understood. In the present study, we show that the release of granular cargo molecules, contained in distinct subsets of granules of mast cells, is specifically mediated by two sets of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins, and that various polyphenols differentially inhibit the formation of those SNARE complexes. Expression analysis of RBL-2H3 cells for 11 SNARE genes and a lipid mixing assay of 24 possible combinations of reconstituted SNAREs indicated that the only two active SNARE complexes involved in mast cell degranulation are Syn (syntaxin) 4/SNAP (23 kDa synaptosome-associated protein)-23/VAMP (vesicle-associated membrane protein) 2 and Syn4/SNAP-23/VAMP8. Various polyphenols selectively or commonly interfered with ternary complex formation of these two SNARE complexes, thereby stopping membrane fusion between granules and plasma membrane. This led to the differential effect of polyphenols on degranulation of three distinct subsets of granules. These results suggest the possibility that formation of a variety of SNARE complexes in numerous cell types is controlled by polyphenols which, in turn, might regulate corresponding membrane trafficking. PMID:23252429

  3. Immunohistochemical localization of SNARE core proteins in intrapulpal and intradentinal nerve fibers of rat molar teeth.

    Science.gov (United States)

    Honma, Shiho; Kadono, Kohki; Kawano, Akiyo; Wakisaka, Satoshi

    2017-01-01

    The present study was designed to elucidate whether three soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor (SNARE) core proteins, syntaxin-1, synaptosomal-associated protein of 25kDa (SNAP-25), and vesicle-associated membrane protein-2 (VAMP-2), are present in the dental pulp of the rat molar at both the light and electron microscopic levels. Immunohistochemistry for protein gene product 9.5 (PGP 9.5), a pan-neuronal marker, syntaxin-1, SNAP-25, and VAMP-2 was performed on decalcified rat molars for light and electron microscopic analyses. Double-immunolabeling of PGP 9.5 and the SNARE core proteins, as well as combinations of the SNARE core proteins, was also carried out. PGP 9.5-immunoreactive nerve fibers ran toward the coronal region, ramified at the subodontoblast layer, and formed the subodontoblastic nerve plexus. Most nerve fibers penetrated the predentin and dentin along the dentinal tubules. Most, if not all, nerve fibers displayed immunoreactivity for syntaxin-1, SNAP-25, and VAMP-2. Immunoelectron microscopic analyses confirmed the presence of immunoreactivity for the SNARE core proteins within the intradental axonal elements. The present findings suggest that, since SNARE core proteins participate in the docking and exocytosis of synaptic vesicles in the central nervous system, they may contribute to vesicle exocytosis from the dental nerve fibers even though there are no apparent synapses. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Water-soluble vitamins.

    Science.gov (United States)

    Konings, Erik J M

    2006-01-01

    Simultaneous Determination of Vitamins.--Klejdus et al. described a simultaneous determination of 10 water- and 10 fat-soluble vitamins in pharmaceutical preparations by liquid chromatography-diode-array detection (LC-DAD). A combined isocratic and linear gradient allowed separation of vitamins in 3 distinct groups: polar, low-polar, and nonpolar. The method was applied to pharmaceutical preparations, fortified powdered drinks, and food samples, for which results were in good agreement with values claimed. Heudi et al. described a separation of 9 water-soluble vitamins by LC-UV. The method was applied for the quantification of vitamins in polyvitaminated premixes used for the fortification of infant nutrition products. The repeatability of the method was evaluated at different concentration levels and coefficients of variation were principle in a specific and sensitive method for the determination of free and bound pantothenic acid in a large variety of foods. A French laboratory invited European laboratories to participate in a series of collaborative studies for this method, which will be carried out in 2005/2006. A more sophisticated method was described by Mittermayer et al. They developed an LC-mass spectrometry (LC/MS) method for the determination of vitamin B5 in a wide range of fortified food products. Application of the method to various samples showed consistent results with those obtained by microbiology. Vitamin B6.-Method 2004.07, an LC method for the analysis of vitamin B6 in reconstituted infant formula, was published by Mann et al. In contrast with this method, which quantifies vitamin B6 after converting the phosphorylated and free vitamers into pyridoxine, Viñas et al. published an LC method which determines 6 vitamin B6 related compounds, the 3 B6 vitamers, their corresponding phosphorylated esters, and a metabolite. Accuracy was determined using 2 CRMs. Results were within the certified ranges. Vitamin C.-Franke et al. described an extensive

  5. Circulating levels of osteopontin, osteoprotegerin, total soluble receptor activator of nuclear factor-kappa B ligand, and high-sensitivity C-reactive protein in patients with active rheumatoid arthritis randomized to etanercept alone or in combination with methotrexate

    DEFF Research Database (Denmark)

    Sennels, H.; Sørensen, Steen; Østergaard, Mikkel

    2008-01-01

    OBJECTIVE: To determine whether circulating levels of osteopontin (OPN), osteoprotegerin (OPG), total soluble receptor activator of nuclear factor-kappa B ligand (total sRANKL), and high-sensitivity C-reactive protein (hsCRP) change in patients with rheumatoid arthritis (RA) during immunosuppress......OBJECTIVE: To determine whether circulating levels of osteopontin (OPN), osteoprotegerin (OPG), total soluble receptor activator of nuclear factor-kappa B ligand (total sRANKL), and high-sensitivity C-reactive protein (hsCRP) change in patients with rheumatoid arthritis (RA) during...

  6. Improved early risk stratification of patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention using a combination of serum soluble ST2 and NT-proBNP.

    Directory of Open Access Journals (Sweden)

    Jongwook Yu

    Full Text Available Although soluble suppression of tumorigenicity 2 (sST2 in serum is known to be associated with ischemic heart disease and heart failure, data regarding its prognostic impact in ST-segment elevation myocardial infarction (STEMI is limited. We evaluated the prognostic impacts of serum sST2 and other serum biomarkers in STEMI patients undergoing primary percutaneous coronary intervention (PCI.Consecutive all 323 patients with STEMI that underwent primary PCI were enrolled. Blood tests and samples were obtained in an emergency room. The primary endpoint was 1-year major adverse cardiovascular and cerebrovascular events (MACCEs, defined as a composite of cardiovascular death, non-fatal MI, non-fatal stroke, and ischemia-driven revascularization.Mean age was 59.1±13.1 years (men 84%. MACCE (20 cardiovascular deaths, 7 non-fatal MI, 4 non-fatal stroke, 7 ischemia-driven revascularizations occurred in 38 patients (12%. After adjusting for confounding factors, Cox regression analysis revealed that high serum sST2 (>75.8 ng/mL mean value, adjusted hazard ratio 2.098, 95% CI 1.008-4.367, p = 0.048 and high serum NT-proBNP level (>400 pg/mL, adjusted hazard ratio 2.606, 95% CI 1.086-6.257, p = 0.032 at the time of presentation independently predicted MACCE within a year of primary PCI. Furthermore, when high serum sST2 level was combined with high serum NT-proBNP level, the hazard ratio of MACCE was highest (adjusted hazard ratio 7.93, 95% CI 2.97-20.38, p<0.001.Elevated serum levels of sST2 or NT-proBNP at the time of presentation were found to predict 1-year MACCE independently and elevated serum levels of sST2 plus NT-proBNP were associated with even poorer prognosis in patients with STEMI undergoing primary PCI.

  7. Replacement of fish meal with soybean meal, alone or in combination with distiller’s dried grains with solubles in practical diets for Pacific white shrimp, Litopenaeus vannamei, grown in a clear-water system

    Science.gov (United States)

    The objective of this study was to evaluate inclusion of distiller’s dried grains with solubles (DDGS) as partial replacement of commercial, solvent-extracted soybean meal (SBM) in fish meal-free diets for Pacific white shrimp, Litopenaeus vannamei. Aquaria connected to a recirculating biofiltratio...

  8. Solubility Part 1

    NARCIS (Netherlands)

    Tantra, Ratna; Bolea, Eduardo; Bouwmeester, H.; Rey-Castro, Carlos; David, C.A.A.; Dogné, Jean Michel; Laborda, Francisco; Laloy, Julie; Robinson, Kenneth N.; Undas, A.K.; Zande, van der M.

    2016-01-01

    This chapter gives an overview of different methods that can potentially be used to determine the solubility of nanomaterials. In general, the methods presented can be broadly divided into four categories: separation methods, methods to quantify free ions, methods to quantify total dissolved

  9. Soluble CD163

    DEFF Research Database (Denmark)

    Møller, Holger J

    2012-01-01

    CD163 is an endocytic receptor for haptoglobin-hemoglobin complexes and is expressed solely on macrophages and monocytes. As a result of ectodomain shedding, the extracellular portion of CD163 circulates in blood as a soluble protein (sCD163) at 0.7-3.9 mg/l in healthy individuals. The function...

  10. Evaluation of Matrix Tablets Based on Eudragit®E100/Carbopol®971P Combinations for Controlled Release and Improved Compaction Properties of Water Soluble Model Drug Paracetamol

    OpenAIRE

    Obeidat, Wasfy M.; Nokhodchi, Ali; Alkhatib, Hatim

    2015-01-01

    The purpose of this work was to investigate the influence of Eudragit®E100 polymer in modifying the release rates and compaction properties of water soluble model drug paracetamol from Carbopol®971P NF polymer matrix tablets prepared by direct compression. The effects of the ratio of the two polymers, the total polymeric content, and the tablets mechanical strength on paracetamol release rates were investigated. Dissolution studies were conducted using USP XX Π rotating paddle apparatus at 50...

  11. Water-Soluble Metallocene-Containing Polymers.

    Science.gov (United States)

    Alkan, Arda; Wurm, Frederik R

    2016-09-01

    Metallocenes are organometallic compounds with reversible redox profiles and tunable oxidation and reduction potentials, depending on the metal and substituents at the cyclopentadienyl rings. Metallocenes have been introduced in macromolecules to combine the redox-activity with polymer properties. There are many examples of such hydrophobic polymer materials, but much fewer water-soluble examples are found scattered across the polymer literature. However, in terms of drug delivery and other biological applications, water solubility is essential. For this very reason, all the synthetic routes to water-soluble metallocene containing polymers are collected and discussed here. The focus is on neutral ferrocene- and ruthenocene-containing and charged cobaltocenium-containing macromolecules (i.e., symmetrical sandwich complexes). The synthetic protocols, self-assembly behavior, and other benefits of the obtained materials are discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Synergism between soluble and dietary fiber bound antioxidants.

    Science.gov (United States)

    Çelik, Ecem Evrim; Gökmen, Vural; Skibsted, Leif H

    2015-03-04

    This study investigates the synergism between antioxidants bound to dietary fibers (DF) of grains and soluble antioxidants of highly consumed beverages or their pure antioxidants. The interaction between insoluble fractions of grains containing bound antioxidants and soluble antioxidants was investigated using (i) a liposome-based system by measuring the lag phase before the onset of oxidation and (ii) an ESR-based system by measuring the reduction percentage of Fremy's salt radical. In both procedures, antioxidant capacities of DF-bound and soluble antioxidants were measured as well as their combinations, which were prepared at different ratios. The simple addition effects of DF-bound and soluble antioxidants were compared with measured values. The results revealed a clear synergism for almost all combinations in both liposome- and ESR-based systems. The synergism observed in DF-bound-soluble antioxidant system paints a promising picture considering the role of fiber in human gastrointestinal (GI) tract health.

  13. Argon solubility in liquid steel

    NARCIS (Netherlands)

    Boom, R; Dankert, O; Van Veen, A; Kamperman, AA

    2000-01-01

    Experiments have been performed to establish the solubility of argon in liquid interstitial-free steel. The solubility appears to be lower than 0.1 at ppb, The results are in line with argon solubilities reported in the literature on liquid iron. Semiempirical theories and calculations based on the

  14. Solubility and Solubility Product Determination of a Sparingly Soluble Salt: A First-Level Laboratory Experiment

    Science.gov (United States)

    Bonomo, Raffaele P.; Tabbi, Giovanni; Vagliasindi, Laura I.

    2012-01-01

    A simple experiment was devised to let students determine the solubility and solubility product, "K"[subscript sp], of calcium sulfate dihydrate in a first-level laboratory. The students experimentally work on an intriguing equilibrium law: the constancy of the product of the ion concentrations of a sparingly soluble salt. The determination of…

  15. Soluble porphyrin polymers

    Science.gov (United States)

    Gust, Jr., John Devens; Liddell, Paul Anthony

    2015-07-07

    Porphyrin polymers of Structure 1, where n is an integer (e.g., 1, 2, 3, 4, 5, or greater) ##STR00001## are synthesized by the method shown in FIGS. 2A and 2B. The porphyrin polymers of Structure 1 are soluble in organic solvents such as 2-MeTHF and the like, and can be synthesized in bulk (i.e., in processes other than electropolymerization). These porphyrin polymers have long excited state lifetimes, making the material suitable as an organic semiconductor for organic electronic devices including transistors and memories, as well as solar cells, sensors, light-emitting devices, and other opto-electronic devices.

  16. Free proline, soluble sugars and soluble proteins concentration as ...

    African Journals Online (AJOL)

    In this study, the effects of salt stress on free proline, soluble sugars and soluble proteins accumulation were investigated in two sugarcane (Saccharum sp.) cultivars: CP66-346 (salt- tolerant) and CP65-357 (salt-sensitive). Young plants of these cultivars were exposed, in a hydroponic system, to four concentrations of NaCl ...

  17. The solubility of hen egg-white lysozyme

    Science.gov (United States)

    Howard, Sandra B.; Twigg, Pamela J.; Baird, James K.; Meehan, Edward J.

    1988-01-01

    The equilibrium solubility of chicken egg-white lysozyme in the presence of crystalline solid state was determined as a function of NaCl concentration, pH, and temperature. The solubility curves obtained represent a region of the lysozyme phase diagram. This diagram makes it possible to determine the supersaturation of a given set of conditions or to achieve identical supersaturations by different combinations of parameters. The temperature dependence of the solubility permits the evaluation of Delta-H of crystallization. The data indicate a negative heat of crystallization for the tetragonal crystal form but a positive heat of crystallization for the high-temperature orthorhombic form.

  18. The Ksp-Solubility Conundrum.

    Science.gov (United States)

    Clark, Roy W.; Bonicamp, Judith M.

    1998-01-01

    Argues that there are only a few cases in which solubility and Ksp are related in a simple way. States that illustrations of the solubility product principle for one-to-one salts are adequate for students. Contains 23 references. (DDR)

  19. Biochemical synthesis of water soluble conducting polymers

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Ferdinando F., E-mail: Ferdinando-Bruno@uml.edu [US Army Natick Soldier Research, Development and Engineering Center, Natick, MA 01760 (United States); Bernabei, Manuele [ITAF, Test Flight Centre, Chemistry Dept. Pratica di Mare AFB, 00071 Pomezia (Rome), Italy (UE) (Italy)

    2016-05-18

    An efficient biomimetic route for the synthesis of conducting polymers/copolymers complexed with lignin sulfonate and sodium (polystyrenesulfonate) (SPS) will be presented. This polyelectrolyte assisted PEG-hematin or horseradish peroxidase catalyzed polymerization of pyrrole (PYR), 3,4 ethyldioxithiophene (EDOT) and aniline has provided a route to synthesize water-soluble conducting polymers/copolymers under acidic conditions. The UV-vis, FTIR, conductivity and cyclic voltammetry studies for the polymers/copolymer complex indicated the presence of a thermally stable and electroactive polymers. Moreover, the use of water-soluble templates, used as well as dopants, provided a unique combination of properties such as high electronic conductivity, and processability. These polymers/copolymers are nowadays tested/evaluated for antirust features on airplanes and helicopters. However, other electronic applications, such as photovoltaics, for transparent conductive polyaniline, actuators, for polypyrrole, and antistatic films, for polyEDOT, will be proposed.

  20. SNARE-Mediated Cholesterol Movement to Mitochondria Supports Steroidogenesis in Rodent Cells

    Science.gov (United States)

    Lin, Ye; Hou, Xiaoming; Shen, Wen-Jun; Hanssen, Ruth; Khor, Victor K.; Cortez, Yuan; Roseman, Ann N.; Azhar, Salman

    2016-01-01

    Vesicular transport involving soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) proteins is known to be responsible for many major cellular activities. In steroidogenic tissues, chronic hormone stimulation results in increased expression of proteins involved in the steroidogenic pathway, whereas acute hormone stimulation prompts the rapid transfer of cholesterol to the inner mitochondrial membrane to be utilized as substrate for steroid hormone production. Several different pathways are involved in supplying cholesterol to mitochondria, but mobilization of stored cholesteryl esters appears to initially constitute the preferred source; however, the mechanisms mediating this cholesterol transfer are not fully understood. To study the potential contribution of SNARE proteins in steroidogenesis, we examined the expression levels of various SNARE proteins in response to hormone stimulation in steroidogenic tissues and cells and established an in vitro mitochondria reconstitution assay system to assess the contribution of various SNARE proteins on cholesterol delivery for steroidogenesis. Our results from reconstitution experiments along with knockdown studies in rat primary granulosa cells and in a Leydig cell line show that soluble N-ethylmaleimide sensitive factor attachment protein-α, synaptosomal-associated protein of 25 kDa, syntaxin-5, and syntaxin-17 facilitate the transport of cholesterol to mitochondria. Thus, although StAR is required for efficient cholesterol movement into mitochondria for steroidogenesis, specific SNAREs participate and are necessary to mediate cholesterol movement to mitochondria. PMID:26771535

  1. Students' mental models on the solubility and solubility product concept

    Science.gov (United States)

    Rahmi, Chusnur; Katmiati, Siti; Wiji, Mulyani, Sri

    2017-05-01

    This study aims to obtain some information regarding profile of students' mental models on the solubility and solubility product concept. A descriptive qualitative method was the method employed in the study. The participants of the study were students XI grade of a senior high school in Bandung. To collect the data, diagnostic test on mental model-prediction, observation, explanation (TDM-POE) instrument was employed in the study. The results of the study revealed that on the concept of precipitation formation of a reaction, 30% of students were not able to explain the precipitation formation of a reaction either in submicroscopic or symbolic level although the microscopic have been shown; 26% of students were able to explain the precipitation formation of a reaction based on the relation of Qsp and Ksp, but they were not able to explain the interaction of particles that involved in the reaction and to calculate Qsp; 26% of students were able to explain the precipitation formation of a reaction based on the relation of Qsp and Ksp, and determine the particles involved, but they did not have the knowledge about the interactions occured and were uncapable of calculating Qsp; and 18% of students were able to explain the precipitation formation of a reaction based on the relation of Qsp and Ksp, and determine the interactions of the particles involved in the reactions but they were not able to calculate Qsp. On the effect of adding common ions and decreasing pH towards the solubility concept, 96% of students were not able to explain the effect of adding common ions and decreasing pH towards the solubility either in submicroscopic or symbolic level although the microscopic have been shown; while 4% of students were only able to explain the effect of adding common ions towards the solubility based on the chemical equilibrium shifts and predict the effect of decreasing pH towards the solubility. However, they were not able to calculate the solubility before and after

  2. Method for estimating solubility parameter

    Science.gov (United States)

    Lawson, D. D.; Ingham, J. D.

    1973-01-01

    Semiempirical correlations have been developed between solubility parameters and refractive indices for series of model hydrocarbon compounds and organic polymers. Measurement of intermolecular forces is useful for assessment of material compatibility, glass-transition temperature, and transport properties.

  3. Pure Phase Solubility Limits: LANL

    Energy Technology Data Exchange (ETDEWEB)

    C. Stockman

    2001-01-26

    The natural and engineered system at Yucca Mountain (YM) defines the site-specific conditions under which one must determine to what extent the engineered and the natural geochemical barriers will prevent the release of radioactive material from the repository. Most important mechanisms for retention or enhancement of radionuclide transport include precipitation or co-precipitation of radionuclide-bearing solid phases (solubility limits), complexation in solution, sorption onto surfaces, colloid formation, and diffusion. There may be many scenarios that could affect the near-field environment, creating chemical conditions more aggressive than the conditions presented by the unperturbed system (such as pH changes beyond the range of 6 to 9 or significant changes in the ionic strength of infiltrated waters). For an extended period of time, the near-field water composition may be quite different and more extreme in pH, ionic strength, and CO{sub 2} partial pressure (or carbonate concentration) than waters at some distance from the repository. Reducing conditions, high pH (up to 11), and low carbonate concentration may be present in the near-field after reaction of infiltrating groundwater with engineered barrier systems, such as cementitious materials. In the far-field, conditions are controlled by the rock-mass buffer providing a near-neutral, oxidizing, low-ionic-strength environment that controls radionuclide solubility limits and sorption capacities. There is the need for characterization of variable chemical conditions that affect solubility, speciation, and sorption reactions. Modeling of the groundwater chemistry is required and leads to an understanding of solubility and speciation of the important radionuclides. Because experimental studies cannot be performed under the numerous potential chemical conditions, solubility limitations must rely on geochemical modeling of the radionuclide's chemistry. Fundamental thermodynamic properties, such as solubility

  4. Combined Electron Paramagnetic Resonance and Atomic Absorption Spectroscopy/Inductively Coupled Plasma Analysis As Diagnostics for Soluble Manganese Species from Mn-Based Positive Electrode Materials in Li-ion Cells.

    Science.gov (United States)

    Shilina, Yuliya; Ziv, Baruch; Meir, Aviv; Banerjee, Anjan; Ruthstein, Sharon; Luski, Shalom; Aurbach, Doron; Halalay, Ion C

    2016-04-19

    Manganese dissolution from positive electrodes significantly reduces the durability of lithium-ion batteries. Knowledge of dissolution rates and oxidation states of manganese ions is essential for designing effective mitigation measures for this problem. We show that electron paramagnetic resonance (EPR) combined with atomic absorption spectroscopy (AAS) or inductively coupled plasma (ICP) can determine both manganese dissolution rates and relative Mn(3+) amounts, by comparing the correlation between EPR and AAS/ICP data for Mn(2+) standards with that for samples containing manganese cations dissolved from active materials (LiMn2O4 (LMO) and LiNi(0.5)Mn(1.5)O4 (LNMO)) into the same electrolyte solution. We show that Mn(3+), and not Mn(2+), is the dominant species dissolved from LMO, while Mn(2+) is predominant for LNMO. Although the dissolution rate of LMO varies significantly for the two investigated materials, due to particle morphology and the presence of Cr in one of them, the Mn speciation appears independent of such details. Thus, the relative abundance of dissolved manganese ions in various oxidation states depends mainly on the overall chemical identity of the active material (LMO vs LNMO). We demonstrate the relevance of our methodology for practical batteries with data for graphite-LMO cells after high-temperature cycling or stand at 4.2 V.

  5. Soluble TACI and soluble BCMA as biomarkers in primary central nervous system lymphoma.

    Science.gov (United States)

    Thaler, Franziska S; Laurent, Sarah A; Huber, Marion; Mulazzani, Matthias; Dreyling, Martin; Ködel, Uwe; Kümpfel, Tania; Straube, Andreas; Meinl, Edgar; von Baumgarten, Louisa

    2017-11-29

    B-cell survival is regulated through interactions of B-cell-activating factor and a proliferation-inducing ligand with their receptors transmembrane activator and CAML interactor (TACI) and B-cell maturation antigen (BCMA). We evaluated the diagnostic potential of soluble TACI (sTACI) and soluble BCMA (sBCMA) in CSF and serum as biomarkers in primary CNS lymphoma (PCNSL). CSF (n = 176) and serum samples (n = 105) from patients with clinically or radiologically suspected PCNSL as well as from control patients were collected prospectively. Levels of sTACI and sBCMA were analyzed by enzyme-linked immunosorbent assay. Additionally, in patients with PCNSL, CSF was analyzed during disease course (time of diagnosis, n = 26; relapse, n = 10; remission, n = 14), and in 2 patients long-term longitudinal analysis was performed. Soluble TACI and sBCMA are significantly increased in patients with PCNSL (sTACI, median: 445 pg/mL; sBCMA, median: 760 pg/mL) compared with control patients (sTACI, median: 0 pg/mL; sBCMA, median: 290 pg/mL). At a cutoff value of 68.4 pg/mL, sTACI shows high sensitivity (87.9%) and specificity (88.3%) for the diagnosis of active PCNSL. Soluble BCMA is less sensitive (72.7%) and specific (71.8%) (cutoff: 460 pg/mL). When both markers are combined, specificity increases, however, at the cost of a lower sensitivity. In serum, both sTACI and sBCMA are not increased in PCNSL patients. Both soluble receptors correlate with clinical course and therapy response. Our results suggest that sTACI and sBCMA in the CSF are promising new biomarkers for diagnosis and therapy monitoring in PCNSL. However, our findings need to be validated in an independent cohort.

  6. Effects of Soluble Corn Fiber Alone or in Synbiotic Combination withLactobacillus rhamnosusGG and the Pilus-Deficient Derivative GG-PB12 on Fecal Microbiota, Metabolism, and Markers of Immune Function: A Randomized, Double-Blind, Placebo-Controlled, Crossover Study in Healthy Elderly (Saimes Study).

    Science.gov (United States)

    Costabile, Adele; Bergillos-Meca, Triana; Rasinkangas, Pia; Korpela, Katri; de Vos, Willem M; Gibson, Glenn R

    2017-01-01

    The aging process leads to a potential decline in immune function and adversely affects the gut microbiota. To date, many in vitro and in vivo studies focused on the application of synbiotics (prebiotics combined with probiotics) as a promising dietary approach to affect gut microbiota composition and improved functioning of the immune system. However, studies using synbiotic preparations often have the limitation that it remains unclear whether any effect observed is a result of the prebiotic or probiotic or a synergistic effect of the combined supplement. We investigated the effects of a probiotic Lactobacillus rhamnosus GG and pilus-deficient L. rhamnosus GG-PB12 combined with Promitor™ Soluble Corn Fiber (SCF, a candidate prebiotic) on fecal microbiota, metabolism, immunity, and blood lipids in healthy elderly persons. A prospective, double-blind, placebo controlled, randomized, single-centered, crossover study in 40 healthy elderly subjects (aged 60-80 years) was carried out. Volunteers were randomized to consume either probiotic and prebiotic as synbiotic, prebiotic or placebo (maltodextrin) during 3 weeks. Three-week washout periods separated all the treatments. We assessed effects upon blood lipids, glucose, cytokines, natural killer (NK) cell activity, phenotype, and intestinal microbiota composition. SCF decreased IL-6, which was not observed with the synbiotics. Consumption of L. rhamnosus GG combined with SCF increased NK cell activity compared to baseline in females and the older group. In the fecal microbiota analyses, the strongest community shifts were due to L. rhamnosus GG combined with SCF and SCF treatments. L. rhamnosus GG combined with SCF and L. rhamnosus GG-PB12 combined with SCF significantly increased the genus Parabacteroides . L. rhamnosus GG combined with SCF and SCF increased concentrations of Ruminococcaceae Incertae Sedis . Oscillospira and Desulfovibrio slightly decreased in the L. rhamnosus GG combined with SCF group, whereas

  7. Effects of Soluble Corn Fiber Alone or in Synbiotic Combination with Lactobacillus rhamnosus GG and the Pilus-Deficient Derivative GG-PB12 on Fecal Microbiota, Metabolism, and Markers of Immune Function: A Randomized, Double-Blind, Placebo-Controlled, Crossover Study in Healthy Elderly (Saimes Study

    Directory of Open Access Journals (Sweden)

    Adele Costabile

    2017-12-01

    Full Text Available BackgroundThe aging process leads to a potential decline in immune function and adversely affects the gut microbiota. To date, many in vitro and in vivo studies focused on the application of synbiotics (prebiotics combined with probiotics as a promising dietary approach to affect gut microbiota composition and improved functioning of the immune system. However, studies using synbiotic preparations often have the limitation that it remains unclear whether any effect observed is a result of the prebiotic or probiotic or a synergistic effect of the combined supplement.ObjectivesWe investigated the effects of a probiotic Lactobacillus rhamnosus GG and pilus-deficient L. rhamnosus GG-PB12 combined with Promitor™ Soluble Corn Fiber (SCF, a candidate prebiotic on fecal microbiota, metabolism, immunity, and blood lipids in healthy elderly persons. A prospective, double-blind, placebo controlled, randomized, single-centered, crossover study in 40 healthy elderly subjects (aged 60–80 years was carried out. Volunteers were randomized to consume either probiotic and prebiotic as synbiotic, prebiotic or placebo (maltodextrin during 3 weeks. Three-week washout periods separated all the treatments. We assessed effects upon blood lipids, glucose, cytokines, natural killer (NK cell activity, phenotype, and intestinal microbiota composition. SCF decreased IL-6, which was not observed with the synbiotics.ResultsConsumption of L. rhamnosus GG combined with SCF increased NK cell activity compared to baseline in females and the older group. In the fecal microbiota analyses, the strongest community shifts were due to L. rhamnosus GG combined with SCF and SCF treatments. L. rhamnosus GG combined with SCF and L. rhamnosus GG-PB12 combined with SCF significantly increased the genus Parabacteroides. L. rhamnosus GG combined with SCF and SCF increased concentrations of Ruminococcaceae Incertae Sedis. Oscillospira and Desulfovibrio slightly decreased in the L

  8. γ-SNAP stimulates disassembly of endosomal SNARE complexes and regulates endocytic trafficking pathways.

    Science.gov (United States)

    Inoue, Hiroki; Matsuzaki, Yuka; Tanaka, Ayaka; Hosoi, Kaori; Ichimura, Kaoru; Arasaki, Kohei; Wakana, Yuichi; Asano, Kenichi; Tanaka, Masato; Okuzaki, Daisuke; Yamamoto, Akitsugu; Tani, Katsuko; Tagaya, Mitsuo

    2015-08-01

    Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) that reside in the target membranes and transport vesicles assemble into specific SNARE complexes to drive membrane fusion. N-ethylmaleimide-sensitive factor (NSF) and its attachment protein, α-SNAP (encoded by NAPA), catalyze disassembly of the SNARE complexes in the secretory and endocytic pathways to recycle them for the next round of fusion events. γ-SNAP (encoded by NAPG) is a SNAP isoform, but its function in SNARE-mediated membrane trafficking remains unknown. Here, we show that γ-SNAP regulates the endosomal trafficking of epidermal growth factor (EGF) receptor (EGFR) and transferrin. Immunoprecipitation and mass spectrometry analyses revealed that γ-SNAP interacts with a limited range of SNAREs, including endosomal ones. γ-SNAP, as well as α-SNAP, mediated the disassembly of endosomal syntaxin-7-containing SNARE complexes. Overexpression and small interfering (si)RNA-mediated depletion of γ-SNAP changed the morphologies and intracellular distributions of endosomes. Moreover, the depletion partially suppressed the exit of EGFR and transferrin from EEA1-positive early endosomes to delay their degradation and uptake. Taken together, our findings suggest that γ-SNAP is a unique SNAP that functions in a limited range of organelles - including endosomes - and their trafficking pathways. © 2015. Published by The Company of Biologists Ltd.

  9. α-SNAP Interferes with the Zippering of the SNARE Protein Membrane Fusion Machinery

    Science.gov (United States)

    Park, Yongsoo; Vennekate, Wensi; Yavuz, Halenur; Preobraschenski, Julia; Hernandez, Javier M.; Riedel, Dietmar; Walla, Peter Jomo; Jahn, Reinhard

    2014-01-01

    Neuronal exocytosis is mediated by soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. Before fusion, SNARE proteins form complexes bridging the membrane followed by assembly toward the C-terminal membrane anchors, thus initiating membrane fusion. After fusion, the SNARE complex is disassembled by the AAA-ATPase N-ethylmaleimide-sensitive factor that requires the cofactor α-SNAP to first bind to the assembled SNARE complex. Using chromaffin granules and liposomes we now show that α-SNAP on its own interferes with the zippering of membrane-anchored SNARE complexes midway through the zippering reaction, arresting SNAREs in a partially assembled trans-complex and preventing fusion. Intriguingly, the interference does not result in an inhibitory effect on synaptic vesicles, suggesting that membrane properties also influence the final outcome of α-SNAP interference with SNARE zippering. We suggest that binding of α-SNAP to the SNARE complex affects the ability of the SNARE complex to harness energy or transmit force to the membrane. PMID:24778182

  10. Free proline, soluble sugars and soluble proteins concentration as ...

    African Journals Online (AJOL)

    These results provided evidence that soluble sugars could contribute mainly to counteract the negative water potential of the outside medium and that protein synthesis stimulation was implicated in sugarcane salt tolerance. Proline appeared as a symptom in salt-stressed sugarcane plants rather than as an indicator of ...

  11. Preliminary considerations concerning actinide solubilities

    Energy Technology Data Exchange (ETDEWEB)

    Newton, T.W.; Bayhurst, B.P.; Daniels, W.R.; Erdal, B.R.; Ogard, A.E.

    1980-01-01

    Work at the Los Alamos Scientific Laboratory on the fundamental solution chemistry of the actinides has thus far been confined to preliminary considerations of the problems involved in developing an understanding of the precipitation and dissolution behavior of actinide compounds under environmental conditions. Attempts have been made to calculate solubility as a function of Eh and pH using the appropriate thermodynamic data; results have been presented in terms of contour maps showing lines of constant solubility as a function of Eh and pH. Possible methods of control of the redox potential of rock-groundwater systems by the use of Eh buffers (redox couples) is presented.

  12. Molecular Structures and Functional Relationships in Clostridial Neurotoxins

    Energy Technology Data Exchange (ETDEWEB)

    Swaminathan S.

    2011-12-01

    The seven serotypes of Clostridium botulinum neurotoxins (A-G) are the deadliest poison known to humans. They share significant sequence homology and hence possess similar structure-function relationships. Botulinum neurotoxins (BoNT) act via a four-step mechanism, viz., binding and internalization to neuronal cells, translocation of the catalytic domain into the cytosol and finally cleavage of one of the three soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) causing blockage of neurotransmitter release leading to flaccid paralysis. Crystal structures of three holotoxins, BoNT/A, B and E, are available to date. Although the individual domains are remarkably similar, their domain organization is different. These structures have helped in correlating the structural and functional domains. This has led to the determination of structures of individual domains and combinations of them. Crystal structures of catalytic domains of all serotypes and several binding domains are now available. The catalytic domains are zinc endopeptidases and share significant sequence and structural homology. The active site architecture and the catalytic mechanism are similar although the binding mode of individual substrates may be different, dictating substrate specificity and peptide cleavage selectivity. Crystal structures of catalytic domains with substrate peptides provide clues to specificity and selectivity unique to BoNTs. Crystal structures of the receptor domain in complex with ganglioside or the protein receptor have provided information about the binding of botulinum neurotoxin to the neuronal cell. An overview of the structure-function relationship correlating the 3D structures with biochemical and biophysical data and how they can be used for structure-based drug discovery is presented here.

  13. Rapid product analysis and increased sensitivity for quantitative determinations of botulinum neurotoxin proteolytic activity.

    Science.gov (United States)

    Rowe, Benjamin; Schmidt, James J; Smith, Leonard A; Ahmed, S Ashraf

    2010-01-15

    The ultimate molecular action of botulinum neurotoxin (BoNT) is a Zn-dependent endoproteolytic activity on one of the three SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins. There are seven serotypes (A-G) of BoNT having distinct cleavage sites on the SNARE substrates. The proteolytic activity is located on the N-terminal light chain (Lc) domain and is used extensively as the primary target toward therapeutic development against botulism. Here we describe an improved method using ultra-performance liquid chromatography (UPLC) whereby quantitative data were obtained in 1/10th the time using 1/20th the sample and solvent volumes compared with a widely used high-performance liquid chromatography (HPLC) method. We also synthesized a VAMP (vesicle-associated membrane protein)-based peptide containing an intact V1 motif that was efficiently used as a substrate by BoNT/D Lc. Although serotype C1 cleaves the serotype A substrate at a bond separated by only one residue, we were able to distinguish the two reactions by UPLC. The new method can accurately quantify as low as 7 pmol of the peptide substrates for BoNT serotypes A, B, C1, and D. We also report here that the catalytic efficiency of serotype A can be stimulated 35-fold by the addition of Triton X-100 to the reaction mixture. Combining the use of Triton X-100 with the newly introduced UPLC method, we were able to accurately detect very low levels of proteolytic activity in a very short time. Sensitivity of the assay and accuracy and rapidity of product analysis should greatly augment efforts in therapeutic development.

  14. SNAP-23 and VAMP-3 contribute to the release of IL-6 and TNFα from a human synovial sarcoma cell line.

    Science.gov (United States)

    Boddul, Sanjay V; Meng, Jianghui; Dolly, James Oliver; Wang, Jiafu

    2014-02-01

    Fibroblast-like synoviocytes are important mediators of inflammatory joint damage in arthritis through the release of cytokines, but it is unknown whether their exocytosis from these particular cells is SNARE-dependent. Here, the complement of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) in human synovial sarcoma cells (SW982) was examined with respect to the secretion of interleukin-6 (IL-6) and tumour necrosis factor α (TNFα), before and after knockdown of a synaptosome-associated protein of molecular mass 23 kDa (SNAP-23) or the vesicle-associated membrane protein 3 (VAMP-3). Wild-type SW982 cells expressed SNAP-23, VAMP-3, syntaxin isoforms 2-4 and synaptic vesicle protein 2C (SV2C). These cells showed Ca²⁺-dependent secretion of IL-6 and TNFα when stimulated by interleukin-1β (IL-1β) or in combination with K⁺ depolarization. Specific knockdown of SNAP-23 or VAMP-3 decreased the exocytosis of IL-6 and TNFα; the reduced expression of SNAP-23 caused accumulation of SV2 in the peri-nuclear area. A monoclonal antibody specific for VAMP-3 precipitated SNAP-23 and syntaxin-2 (and syntaxin-3 to a lesser extent). The formation of SDS-resistant complexes by SNAP-23 and VAMP-3 was reduced upon knockdown of SNAP-23. Although the syntaxin isoforms 2, 3 and 4 are expressed in SW982 cells, knockdown of each did not affect the release of cytokines. Collectively, these results show that SNAP-23 and VAMP-3 participate in IL-1β-induced Ca²⁺-dependent release of IL-6 and TNFα from SW982 cells. © 2013 FEBS.

  15. Solubility limits on radionuclide dissolution

    Energy Technology Data Exchange (ETDEWEB)

    Kerrisk, J.F.

    1984-12-31

    This paper examines the effects of solubility in limiting dissolution rates of a number of important radionuclides from spent fuel and high-level waste. Two simple dissolution models were used for calculations that would be characteristics of a Yucca Mountain repository. A saturation-limited dissolution model, in which the water flowing through the repository is assumed to be saturated with each waste element, is very conservative in that it overestimates dissolution rates. A diffusion-limited dissolution model, in which element-dissolution rates are limited by diffusion of waste elements into water flowing past the waste, is more realistic, but it is subject to some uncertainty at this time. Dissolution rates of some elements (Pu, Am, Sn, Th, Zr, Sm) are always limited by solubility. Dissolution rates of other elements (Cs, Tc, Np, Sr, C, I) are never solubility limited; their release would be limited by dissolution of the bulk waste form. Still other elements (U, Cm, Ni, Ra) show solubility-limited dissolution under some conditions. 9 references, 3 tables.

  16. Formulation of a Novel Nanoemulsion System for Enhanced Solubility of a Sparingly Water Soluble Antibiotic, Clarithromycin

    Directory of Open Access Journals (Sweden)

    Stuti Vatsraj

    2014-01-01

    Full Text Available The sparingly water soluble property of majority of medicinally significant drugs acts as a potential barrier towards its utilization for therapeutic purpose. The present study was thus aimed at development of a novel oil-in-water (o/w nanoemulsion (NE system having ability to function as carrier for poorly soluble drugs with clarithromycin as a model antibiotic. The therapeutically effective concentration of clarithromycin, 5 mg/mL, was achieved using polysorbate 80 combined with olive oil as lipophilic counterion. A three-level three-factorial central composite experimental design was utilized to conduct the experiments. The effects of selected variables, polysorbate 80 and olive oil content and concentration of polyvinyl alcohol, were investigated. The particle size of clarithromycin for the optimized formulation was observed to be 30 nm. The morphology of the nanoemulsion was explored using transmission electron microscopy (TEM. The emulsions prepared with the optimized formula demonstrated good physical stability during storage at room temperature. Antibacterial activity was conducted with the optimized nanoemulsion NESH 01 and compared with free clarithromycin. Zone of inhibition was larger for NESH 01 as compared to that with free clarithromycin. This implies that the solubility and hence the bioavailability of clarithromycin has increased in the formulated nanoemulsion system.

  17. Overexpression of Soluble Recombinant Human Lysyl Oxidase by Using Solubility Tags: Effects on Activity and Solubility

    Directory of Open Access Journals (Sweden)

    Madison A. Smith

    2016-01-01

    Full Text Available Lysyl oxidase is an important extracellular matrix enzyme that has not been fully characterized due to its low solubility. In order to circumvent the low solubility of this enzyme, three solubility tags (Nus-A, Thioredoxin (Trx, and Glutathione-S-Transferase (GST were engineered on the N-terminus of mature lysyl oxidase. Total enzyme yields were determined to be 1.5 mg for the Nus-A tagged enzyme (0.75 mg/L of media, 7.84 mg for the Trx tagged enzyme (3.92 mg/L of media, and 9.33 mg for the GST tagged enzyme (4.67 mg/L of media. Enzymatic activity was calculated to be 0.11 U/mg for the Nus-A tagged enzyme and 0.032 U/mg for the Trx tagged enzyme, and no enzymatic activity was detected for the GST tagged enzyme. All three solubility-tagged forms of the enzyme incorporated copper; however, the GST tagged enzyme appears to bind adventitious copper with greater affinity than the other two forms. The catalytic cofactor, lysyl tyrosyl quinone (LTQ, was determined to be 92% for the Nus-A and Trx tagged lysyl oxidase using the previously reported extinction coefficient of 15.4 mM−1 cm−1. No LTQ was detected for the GST tagged lysyl oxidase. Given these data, it appears that Nus-A is the most suitable tag for obtaining soluble and active recombinant lysyl oxidase from E. coli culture.

  18. Overexpression of Soluble Recombinant Human Lysyl Oxidase by Using Solubility Tags: Effects on Activity and Solubility.

    Science.gov (United States)

    Smith, Madison A; Gonzalez, Jesica; Hussain, Anjum; Oldfield, Rachel N; Johnston, Kathryn A; Lopez, Karlo M

    2016-01-01

    Lysyl oxidase is an important extracellular matrix enzyme that has not been fully characterized due to its low solubility. In order to circumvent the low solubility of this enzyme, three solubility tags (Nus-A, Thioredoxin (Trx), and Glutathione-S-Transferase (GST)) were engineered on the N-terminus of mature lysyl oxidase. Total enzyme yields were determined to be 1.5 mg for the Nus-A tagged enzyme (0.75 mg/L of media), 7.84 mg for the Trx tagged enzyme (3.92 mg/L of media), and 9.33 mg for the GST tagged enzyme (4.67 mg/L of media). Enzymatic activity was calculated to be 0.11 U/mg for the Nus-A tagged enzyme and 0.032 U/mg for the Trx tagged enzyme, and no enzymatic activity was detected for the GST tagged enzyme. All three solubility-tagged forms of the enzyme incorporated copper; however, the GST tagged enzyme appears to bind adventitious copper with greater affinity than the other two forms. The catalytic cofactor, lysyl tyrosyl quinone (LTQ), was determined to be 92% for the Nus-A and Trx tagged lysyl oxidase using the previously reported extinction coefficient of 15.4 mM(-1 )cm(-1). No LTQ was detected for the GST tagged lysyl oxidase. Given these data, it appears that Nus-A is the most suitable tag for obtaining soluble and active recombinant lysyl oxidase from E. coli culture.

  19. Water-Soluble Nanodiamond (Postprint)

    Science.gov (United States)

    2012-03-01

    nanodiamond salt that reacts with either alkyl or aryl halides by electron transfer to yield radical anions that dissociate spontaneously into free radicals...sodium in liquid ammonia leads to the nanodiamond salt 1. This material can be reacted with either alkyl or aryl halides to yield a radical anion that...From - To) March 2012 Technical Paper 1 October 2008 – 1 March 2012 4. TITLE AND SUBTITLE WATER-SOLUBLE NANODIAMOND (POSTPRINT) 5a. CONTRACT

  20. The Solubility Parameters of Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Andrzej Marciniak

    2010-04-01

    Full Text Available The Hildebrand’s solubility parameters have been calculated for 18 ionic liquids from the inverse gas chromatography measurements of the activity coefficients at infinite dilution. Retention data were used for the calculation. The solubility parameters are helpful for the prediction of the solubility in the binary solvent mixtures. From the solubility parameters, the standard enthalpies of vaporization of ionic liquids were estimated.

  1. MISCIBILITY, SOLUBILITY, AND VISCOSITY MEASUREMENTS FOR R-236EA WITH POTENTIAL LUBRICANTS

    Science.gov (United States)

    The report gives results of miscibility, solubility, and viscosity measurements of refrigerant R-236ea with three potential lubricants. (NOTE: The data were needed to determine the suitability of refrigerant/lubricant combinations for use in refrigeration systems.) The lubricants...

  2. Toward a Molecular Understanding of Protein Solubility: Increased Negative Surface Charge Correlates with Increased Solubility

    OpenAIRE

    Kramer, Ryan M.; Shende, Varad R.; Motl, Nicole; Pace, C. Nick; Scholtz, J. Martin

    2012-01-01

    Protein solubility is a problem for many protein chemists, including structural biologists and developers of protein pharmaceuticals. Knowledge about how intrinsic factors influence solubility is limited due to the difficulty of obtaining quantitative solubility measurements. Solubility measurements in buffer alone are difficult to reproduce, because gels or supersaturated solutions often form, making it impossible to determine solubility values for many proteins. Protein precipitants can be ...

  3. Modified water solubility of milk protein concentrate powders through the application of static high pressure treatment.

    Science.gov (United States)

    Udabage, Punsandani; Puvanenthiran, Amirtha; Yoo, Jin Ah; Versteeg, Cornelis; Augustin, Mary Ann

    2012-02-01

    The effects of high pressure (HP) treatment (100-400 MPa at 10-60 °C) on the solubility of milk protein concentrate (MPC) powders were tested. The solubility, measured at 20 °C, of fresh MPC powders made with no HP treatment was 66%. It decreased by 10% when stored for 6 weeks at ambient temperature (~20 °C) and continued to decrease to less than 50% of its initial solubility after 12 months of storage. Of the combinations of pressure and heat used, a pressure of 200 MPa at 40 °C applied to the concentrate before spray drying was found to be the most beneficial for improved solubility of MPC powders. This combination of pressure/heat improved the initial cold water solubility to 85%. The solubility was maintained at this level after 6 weeks storage at ambient temperature and 85% of the initial solubility was preserved after 12 months. The improved solubility of MPC powders on manufacture and on storage are attributed to an altered surface composition arising from an increased concentration of non-micellar casein in the milk due to HP treatment prior to drying. The improved solubility of high protein powders (95% protein) made from blends of sodium caseinate and whey protein isolate compared with MPC powders (~85% protein) made from ultrafiltered/diafiltered milk confirmed the detrimental role of micellar casein on solubility. The results suggest that increasing the non-micellar casein content by HP treatment of milk or use of blends of sodium caseinate and whey proteins are strategies that may be used to obtain high protein milk powders with enhanced solubility.

  4. Concomitant intake of alcohol may increase the absorption of poorly soluble drugs.

    Science.gov (United States)

    Fagerberg, Jonas H; Sjögren, Erik; Bergström, Christel A S

    2015-01-25

    Ethanol can increase the solubility of poorly soluble and hence present a higher drug concentration in the gastrointestinal tract. This may produce a faster and more effective absorption resulting in variable and/or high drug plasma concentrations, both of which can lead to adverse drug reactions. In this work we therefore studied the solubility and absorption effects of nine diverse compounds when ethanol was present. The apparent solubility was measured using the μDiss Profiler Plus (pION, MA) in four media representing gastric conditions with and without ethanol. The solubility results were combined with in-house data on solubility in intestinal fluids (with and without ethanol) and pharmacokinetic parameters extracted from the literature and used as input in compartmental absorption simulations using the software GI-Sim. Apparent solubility increased more than 7-fold for non-ionized compounds in simulated gastric fluid containing 20% ethanol. Compounds with weak base functions (cinnarizine, dipyridamole and terfenadine) were completely ionized at the studied gastric pH and their solubility was therefore unaffected by ethanol. Compounds with low solubility in intestinal media and a pronounced solubility increase due to ethanol in the upper gastric compartments showed an increased absorption in the simulations. The rate of absorption of the acidic compounds indomethacin and indoprofen was slightly increased but the extent of absorption was unaffected as the complete doses were readily absorbed even without ethanol. This was likely due to a high apparent solubility in the intestinal compartment where the weak acids are ionized. The absorption of the studied non-ionizable compounds increased when ethanol was present in the gastric and intestinal media. These results indicate that concomitant intake of alcohol may significantly increase the solubility and hence, the plasma concentration for non-ionizable, lipophilic compounds with the potential of adverse drug

  5. Radionuclide solubility control by solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, F.; Klinkenberg, M.; Rozov, K.; Bosbach, D. [Forschungszentrum Juelich GmbH (Germany). Inst. of Energy and Climate Research - Nuclear Waste Management and Reactor Safety (IEK-6); Vinograd, V. [Frankfurt Univ. (Germany). Inst. of Geosciences

    2015-07-01

    The migration of radionuclides in the geosphere is to a large extend controlled by sorption processes onto minerals and colloids. On a molecular level, sorption phenomena involve surface complexation, ion exchange as well as solid solution formation. The formation of solid solutions leads to the structural incorporation of radionuclides in a host structure. Such solid solutions are ubiquitous in natural systems - most minerals in nature are atomistic mixtures of elements rather than pure compounds because their formation leads to a thermodynamically more stable situation compared to the formation of pure compounds. However, due to a lack of reliable data for the expected scenario at close-to equilibrium conditions, solid solution systems have so far not been considered in long-term safety assessments for nuclear waste repositories. In recent years, various solid-solution aqueous solution systems have been studied. Here we present state-of-the art results regarding the formation of (Ra,Ba)SO{sub 4} solid solutions. In some scenarios describing a waste repository system for spent nuclear fuel in crystalline rocks {sup 226}Ra dominates the radiological impact to the environment associated with the potential release of radionuclides from the repository in the future. The solubility of Ra in equilibrium with (Ra,Ba)SO{sub 4} is much lower than the one calculated with RaSO{sub 4} as solubility limiting phase. Especially, the available literature data for the interaction parameter W{sub BaRa}, which describes the non-ideality of the solid solution, vary by about one order of magnitude (Zhu, 2004; Curti et al., 2010). The final {sup 226}Ra concentration in this system is extremely sensitive to the amount of barite, the difference in the solubility products of the end-member phases, and the degree of non-ideality of the solid solution phase. Here, we have enhanced the fundamental understanding regarding (1) the thermodynamics of (Ra,Ba)SO{sub 4} solid solutions and (2) the

  6. A Path to Soluble Molecularly Imprinted Polymers

    Science.gov (United States)

    Verma, Abhilasha; Murray, George M.

    2011-01-01

    Molecular imprinting is a technique for making a selective binding site for a specific chemical. The technique involves building a polymeric scaffold of molecular complements containing the target molecule. Subsequent removal of the target leaves a cavity with a structural “memory” of the target. Molecularly imprinted polymers (MIPs) can be employed as selective adsorbents of specific molecules or molecular functional groups. In addition, sensors for specific molecules can be made using optical transduction through lumiphores residing in the imprinted site. We have found that the use of metal ions as chromophores can improve selectivity due to selective complex formation. The combination of molecular imprinting and spectroscopic selectivity can result in sensors that are highly sensitive and nearly immune to interferences. A weakness of conventional MIPs with regard to processing is the insolubility of crosslinked polymers. Traditional MIPs are prepared either as monoliths and ground into powders or are prepared in situ on a support. This limits the applicability of MIPs by imposing tedious or difficult processes for their inclusion in devices. The size of the particles hinders diffusion and slows response. These weaknesses could be avoided if a means were found to prepare individual macromolecules with crosslinked binding sites with soluble linear polymeric arms. This process has been made possible by controlled free radical polymerization techniques that can form pseudo-living polymers. Modern techniques of controlled free radical polymerization allow the preparation of block copolymers with potentially crosslinkable substituents in specific locations. The inclusion of crosslinkable mers proximate to the binding complex in the core of a star polymer allows the formation of molecularly imprinted macromolecules that are soluble and processable. Due to the much shorter distance for diffusion, the polymers exhibit rapid responses. This paper reviews the methods

  7. Solubility of hydrogen sulfide in n-methylpyrrolidone

    Energy Technology Data Exchange (ETDEWEB)

    Yarym-Agaev, N.L.; Matvienko, V.G.; Povalyaeva, N.V.

    1980-01-01

    The solubility of hydrogen sulfide in N-methylpyrrolidone was investigated over wide ranges of temperature and pressure. The dynamic variant of the gravimetric method was used at hydrogen sulfide pressures equal to or below atmospheric, and the static variant at higher pressures. In the dynamic variant of the gravimetric method hydrogen sulfide is passed through a known amount of solvent until saturation is reached, and the amount of gas dissolved is found from the weight increase. This method is particularly convenient in studies of highly soluble gases when the solvent has a low vapor pressure. If the vapor pressure of the solvent exceeded this value a correction for entrainment of solvent vapor by undissolved gas was applied. The study showed that the solubility of hydrogen sulfide in N-methylpyrrolidone rose steeply with increase of pressure and decrease of temperature and that it can be used as an effective absorbent of hydrogen sulfide in highly sulfurous natural gas. Since the solubility of hydrogen sulfide under atmospheric pressure is fairly high even at elevated temperatures, effective regeneration of N-methylpyrrolidone is possible by a combination of heating and blowing with an inert gas or by application of vacuum for removal of the hydrogen sulfide.

  8. Dye solubility in supercritical carbon dioxide fluid

    Directory of Open Access Journals (Sweden)

    Yan Jun

    2015-01-01

    Full Text Available Supercritical carbon dioxide fluid is an alternative solvent for the water of the traditional dyeing. The solubility of dyestuff affects greatly the dyeing process. A theoretical model for predicting the dye solubility is proposed and verified experimentally. The paper concludes that the pressure has a greater impact on the dyestuff solubility than temperature, and an optimal dyeing condition is suggested for the highest distribution coefficient of dyestuff.

  9. Issues concerning the determination of solubility products of sparingly soluble crystalline solids. Solubility of HfO{sub 2}(cr)

    Energy Technology Data Exchange (ETDEWEB)

    Rai, Dhanpat [Rai Enviro-Chem, LLC, Yachats, OR (United States); Kitamura, Akira [Japan Atomic Energy Agency, Ibaraki (Japan); Rosso, Kevin M. [Pacific Northwest National Laboratory, Richland, WA (United States); Sasaki, Takayuki; Kobayashi, Taishi [Kyoto Univ. (Japan)

    2016-11-01

    Solubility studies were conducted with HfO{sub 2}(cr) solid as a function HCl and ionic strength ranging from 2.0 to 0.004 mol kg{sup -1}. These studies involved (1) using two different amounts of the solid phase, (2) acid washing the bulk solid phase, (3) preheating the solid phase to 1400 C, and (4) heating amorphous HfO{sub 2}(am) suspensions to 90 C to ascertain whether the HfO{sub 2}(am) converts to HfO{sub 2}(cr) and to determine the solubility from the oversaturation direction. Based on the results of these treatments it is concluded that the HfO{sub 2}(cr) contains a small fraction of less crystalline, but not amorphous, material [HfO{sub 2}(lcr)] and this, rather than the HfO{sub 2}(cr), is the solubility-controlling phase in the range of experimental variables investigated in this study. The solubility data are interpreted using both the Pitzer and SIT models and they provide log{sub 10} K{sup 0} values of -(59.75±0.35) and -(59.48±0.41), respectively, for the solubility product of HfO{sub 2}(lcr)[HfO{sub 2}(lcr) + 2H{sub 2}O ↔ Hf{sup 4+} + 4OH{sup -}]. The log{sub 10} of the solubility product of HfO{sub 2}(cr) is estimated to be < -63. The observation of a small fraction of less crystalline higher solubility material is consistent with the general picture that mineral surfaces are often structurally and/or compositionally imperfect leading to a higher solubility than the bulk crystalline solid. This study stresses the urgent need, during interpretation of solubility data, of taking precautions to make certain that the observed solubility behavior for sparingly-soluble solids is assigned to the proper solid phase.

  10. IUPAC-NIST Solubility Data Series. 97. Solubility of Higher Acetylenes and Triple Bonded Derivatives

    Science.gov (United States)

    Skrzecz, Adam

    2013-03-01

    Solubility of Ethyne in Liquids was published in 2001 as Vol. 76 of the IUPAC-NIST Solubility Data Series. The current work extends the coverage to the solubility in liquids of higher gaseous and liquid acetylenes and to derivatives that contain a triple carbon-carbon bond. Predictive methods for estimating solubilities in water are summarised and usually give values to within an order of magnitude. The literature has been surveyed to the end of 2010.

  11. Solubility of acetaminophen in polyethylene glycol 400 + water mixtures according to the extended hildebrand solubility approach

    OpenAIRE

    Edgar Ahumada; Daniel Delgado; Fleming Martínez

    2014-01-01

    The Extended Hildebrand Solubility Approach(EHSA) was applied in the presentwork to evaluate the solubility of theanalgesic drug acetaminophen (paracetamol)in polyethylene glycol 400 + watermixtures at 298.15 K. An acceptablecorrelative capacity of EHSA was foundusing a regular polynomial model in orderfour (overall deviation below 0.7%),when the W interaction parameter is relatedto the solubility parameter of themixtures. Thus, the deviations obtainedin the estimated solubility with respect ...

  12. Indomethacin solubility in propylene glycol + water mixtures according to the extended hildebrand solubility approach

    OpenAIRE

    Holguín, Andrés R.; Delgado, Daniel R.; Martínez, Fleming

    2012-01-01

    In this work the Extended Hildebrand Solubility Approach (EHSA) was applied to evaluate the solubility of the analgesic drug indomethacin in propylene glycol + water mixtures at 298.15 K. An acceptable correlative capacity of EHSA was found using a regular polynomial model in order four (overall deviation lower than 2.2 %), when the W interaction parameter is related to the solubility parameter of the mixtures. Nevertheless, the deviations obtained in the estimated solubility with respect to ...

  13. Soluble Metal-Nanoparticle-Decorated Porous Coordination Polymers for the Homogenization of Heterogeneous Catalysis.

    Science.gov (United States)

    Huang, Yuan-Biao; Wang, Qiang; Liang, Jun; Wang, Xusheng; Cao, Rong

    2016-08-17

    Ultrasmall metal nanoparticles (MNPs) were decorated on soluble porous coordination polymers (PCPs) with high metal loadings. The solubility of the composite and the size of the MNPs can be controlled by varying the ratio of the precursors to the supports. The soluble PCPs can serve as a platform to homogenize heterogeneous MNPs catalysts, which exhibited excellent activity and recyclability in C-H activation and Suzuki reactions. This strategy combines the advantages of homogeneous and heterogeneous catalysis and may bring new inspiration to catalysis.

  14. In Vitro Phosphorus Solubility Test of Different Sources of Phosphorus

    OpenAIRE

    Hifizah, A

    2011-01-01

    The solubility of P from different P supplements was measured with in vitro procedures, using three different tests, which were water solubility, citric acid solubility and acid (0.1M HCl) solubility. Water solubility and citrate solubility were common tests used by the fertiliser industry and acid solubility was a new test developed to mimic conditions within the digestive tract. There were five samples used: Lomon MDCP, Duchess RP, Kynofos, meat meal and MSOP. A separate test was done with ...

  15. Temperature and curing time affect composite sorption and solubility

    Directory of Open Access Journals (Sweden)

    Fabrício Luscino Alves de Castro

    2013-04-01

    Full Text Available Objective: This study evaluated the effect of temperature and curing time on composite sorption and solubility. Material and Methods: Seventy five specimens (8×2 mm were prepared using a commercial composite resin (ICE, SDI. Three temperatures (10°C, 25°C and 60°C and five curing times (5 s, 10 s, 20 s, 40 s and 60 s were evaluated. The specimens were weighed on an analytical balance three times: A: before storage (M1; B: 7 days after storage (M2; C: 7 days after storage plus 1 day of drying (M3. The storage solution consisted of 75% alcohol/25% water. Sorption and solubility were calculated using these three weights and specimen dimensions. The data were analyzed using the Kruskal-Wallis and Mann-Whitney U Tests (α=5%. Results: The results showed that time, temperature and their interaction influenced the sorption and solubility of the composite (p0.05. The 60°C composite temperature led to lower values of sorption for all curing times when compared with the 10°C temperature (p0.05. Solubility was similar at 40 s and 60 s for all temperatures (p>0.05, but was higher at 10°C than at 60°C for all curing times (p0.05. Conclusions: In conclusion, higher temperatures or longer curing times led to lower sorption and solubility values for the composite tested; however, this trend was only significant in specific combinations of temperature and curing times.

  16. Soluble cytokine receptors in biological therapy.

    Science.gov (United States)

    Fernandez-Botran, Rafael; Crespo, Fabian A; Sun, Xichun

    2002-08-01

    Due to their fundamental involvement in the pathogenesis of many diseases, cytokines constitute key targets for biotherapeutic approaches. The discovery that soluble forms of cytokine receptors are involved in the endogenous regulation of cytokine activity has prompted substantial interest in their potential application as immunotherapeutic agents. As such, soluble cytokine receptors have many advantages, including specificity, low immunogenicity and high affinity. Potential disadvantages, such as low avidity and short in vivo half-lifes, have been addressed by the use of genetically-designed receptors, hybrid proteins or chemical modifications. The ability of many soluble cytokine receptors to inhibit the binding and biological activity of their ligands makes them very specific cytokine antagonists. Several pharmaceutical companies have generated a number of therapeutic agents based on soluble cytokine receptors and many of them are undergoing clinical trials. The most advanced in terms of clinical development is etanercept (Enbrel, Immunex), a fusion protein between soluble TNF receptor Type II and the Fc region of human IgG1. This TNF-alpha; antagonist was the first soluble cytokine receptor to receive approval for use in humans. In general, most agents based on soluble cytokine receptors have been safe, well-tolerated and have shown only minor side effects in the majority of patients. Soluble cytokine receptors constitute a new generation of therapeutic agents with tremendous potential for applications in a wide variety of human diseases. Two current areas of research are the identification of their most promising applications and characterisation of their long-term effects.

  17. A Colorful Solubility Exercise for Organic Chemistry

    Science.gov (United States)

    Shugrue, Christopher R.; Mentzen, Hans H., II; Linton, Brian R.

    2015-01-01

    A discovery chemistry laboratory has been developed for the introductory organic chemistry student to investigate the concepts of polarity, miscibility, solubility, and density. The simple procedure takes advantage of the solubility of two colored dyes in a series of solvents or solvent mixtures, and the diffusion of colors can be easily…

  18. Solubility Study of Curatives in Various Rubbers

    NARCIS (Netherlands)

    Guo, R.; Talma, Auke; Datta, Rabin; Dierkes, Wilma K.; Noordermeer, Jacobus W.M.

    2008-01-01

    The previous works on solubility of curatives in rubbers were mainly carried out in natural rubber. Not too much information available on dissimilar rubbers and this is important because most of the compounds today are blends of dissimilar rubbers. Although solubility can be expected to certain

  19. Enhancement of Solubility and Bioavailability of Candesartan ...

    African Journals Online (AJOL)

    Purpose: To enhance the otherwise poor solubility and bioavailability of candesartan cilexetil (CDS). Methods: This study involved enhancing drug solubility by various solid dispersion (SD) methods. The drug: carrier ratio was as follows: for urea (1:2, 1:4 and 1:6; for polyethylene glycol 6000 (PEG, 1:2 and 1:4, 1:8); and ...

  20. Water-soluble conductive polymers

    Science.gov (United States)

    Aldissi, Mahmoud

    1989-01-01

    Polymers which are soluble in water and are electrically conductive. The monomer repeat unit is a thiophene or pyrrole molecule having an alkyl group substituted for the hydrogen atom located in the beta position of the thiophene or pyrrole ring and having a surfactant molecule at the end of the alkyl chain. Polymers of this class having 8 or more carbon atoms in the alkyl chain exhibit liquid crystalline behavior, resulting in high electrical anisotropy. The monomer-to-monomer bonds are located between the carbon atoms which are adjacent to the sulfur or nitrogen atoms. The number of carbon atoms in the alkyl group may vary from 1 to 20 carbon atoms. The surfactant molecule consists of a sulfonate group, or a sulfate group, or a carboxylate group, and hydrogen or an alkali metal. Negative ions from a supporting electrolyte which may be used in the electrochemical synthesis of a polymer may be incorporated into the polymer during the synthesis and serve as a dopant to increase the conductivity.

  1. Toward a Molecular Understanding of Protein Solubility: Increased Negative Surface Charge Correlates with Increased Solubility

    Science.gov (United States)

    Kramer, Ryan M.; Shende, Varad R.; Motl, Nicole; Pace, C. Nick; Scholtz, J. Martin

    2012-01-01

    Protein solubility is a problem for many protein chemists, including structural biologists and developers of protein pharmaceuticals. Knowledge about how intrinsic factors influence solubility is limited due to the difficulty of obtaining quantitative solubility measurements. Solubility measurements in buffer alone are difficult to reproduce, because gels or supersaturated solutions often form, making it impossible to determine solubility values for many proteins. Protein precipitants can be used to obtain comparative solubility measurements and, in some cases, estimations of solubility in buffer alone. Protein precipitants fall into three broad classes: salts, long-chain polymers, and organic solvents. Here, we compare the use of representatives from two classes of precipitants, ammonium sulfate and polyethylene glycol 8000, by measuring the solubility of seven proteins. We find that increased negative surface charge correlates strongly with increased protein solubility and may be due to strong binding of water by the acidic amino acids. We also find that the solubility results obtained for the two different precipitants agree closely with each other, suggesting that the two precipitants probe similar properties that are relevant to solubility in buffer alone. PMID:22768947

  2. The Structure of the Yeast Plasma Membrane SNARE Complex Reveals Destabilizing Water Filled Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Strop, P.; Kaiser, S.E.; Vrljic, M.; Brunger, A.T.

    2009-05-26

    Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins form a complex that leads to membrane fusion between vesicles, organelles, and plasma membrane in all eukaryotic cells. We report the 1.7{angstrom} resolution structure of the SNARE complex that mediates exocytosis at the plasma membrane in the yeast Saccharomyces cerevisiae. Similar to its neuronal and endosomal homologues, the S. cerevisiae SNARE complex forms a parallel four-helix bundle in the center of which is an ionic layer. The S. cerevisiae SNARE complex exhibits increased helix bending near the ionic layer, contains water-filled cavities in the complex core, and exhibits reduced thermal stability relative to mammalian SNARE complexes. Mutagenesis experiments suggest that the water-filled cavities contribute to the lower stability of the S. cerevisiae complex.

  3. The assembly of lipid droplets and its relation to cellular insulin sensitivity

    DEFF Research Database (Denmark)

    Boström, Pontus; Andersson, Linda; Li, Lu

    2009-01-01

    to be transported on microtubules. Lipid droplets grow in size by fusion, which is dependent on dynein and the transfer on microtubules, and is catalysed by the SNARE (soluble N-ethylmaleimide-sensitive fusion protein-attachment protein receptor) proteins SNAP-23 (23 kDa synaptosome-associated protein), syntaxin-5...... and VAMP-4 (vesicle-associated protein 4). SNAP-23 is also involved in the insulin-dependent translocation of the glucose transporter GLUT4 to the plasma membrane. Fatty acids induce a missorting of SNAP-23, from the plasma membrane to the interior of the cell, resulting in cellular insulin resistance...... that can be overcome by increasing the levels of SNAP-23. The same missorting of SNAP-23 occurs in vivo in skeletal-muscle biopsies from patients with T2D (Type 2 diabetes). Moreover, there was a linear relation between the amount of SNAP-23 in the plasma membrane from human skeletal-muscles biopsies...

  4. Multiple Ca2+ sensors in secretion

    DEFF Research Database (Denmark)

    Walter, Alexander M; Groffen, Alexander J; Sørensen, Jakob Balslev

    2011-01-01

    Regulated neurotransmitter secretion depends on Ca(2+) sensors, C2 domain proteins that associate with phospholipids and soluble N-ethylmaleimide-sensitive fusion attachment protein receptor (SNARE) complexes to trigger release upon Ca(2+) binding. Ca(2+) sensors are thought to prevent spontaneous...... fusion at rest (clamping) and to promote fusion upon Ca(2+) activation. At least eight, often coexpressed, Ca(2+) sensors have been identified in mammals. Accumulating evidence suggests that multiple Ca(2+) sensors interact, rather than work autonomously, to produce the complex secretory response...... observed in neurons and secretory cells. In this review, we present several working models to describe how different sensors might be arranged to mediate synchronous, asynchronous and spontaneous neurotransmitter release. We discuss the scenario that different Ca(2+) sensors typically act on one shared...

  5. Low Soluble Syndecan-1 Precedes Preeclampsia.

    Science.gov (United States)

    Gandley, Robin E; Althouse, Andrew; Jeyabalan, Arundhathi; Bregand-White, Julia M; McGonigal, Stacy; Myerski, Ashley C; Gallaher, Marcia; Powers, Robert W; Hubel, Carl A

    2016-01-01

    Syndecan-1 (Sdc1; CD138) is a major transmembrane heparan sulfate proteoglycan expressed on the extracellular, luminal surface of epithelial cells and syncytiotrophoblast, thus comprising a major component of the glycocalyx of these cells. The "soluble" (shed) form of Sdc1 has paracrine and autocrine functions and is normally produced in a regulated fashion. We compared plasma soluble Sdc1 concentrations, in relation to placental Sdc1 expression, in uncomplicated (control) and preeclamptic pregnancies. We evaluated soluble Sdc1 across uncomplicated pregnancy, and between preeclamptic, gestational hypertensive and control patients at mid-pregnancy (20 weeks) and 3rd trimester by ELISA. Placental expression level of Sdc1 was compared between groups in relation to pre-delivery plasma soluble Sdc1. Participants were recruited from Magee-Womens Hospital. In uncomplicated pregnancy, plasma soluble Sdc1 rose significantly in the 1st trimester, and reached an approximate 50-fold increase at term compared to post pregnancy levels. Soluble Sdc1 was lower at mid-pregnancy in women who later developed preeclampsia (PSoluble Sdc1 and Sdc1 immunostaining scores were inversely associated with systolic blood pressures, and positively correlated with infant birth weight percentile. Soluble Sdc1 is significantly lower before the clinical onset of preeclampsia, with reduced expression of Sdc1 in the delivered placenta, suggesting a role for glycocalyx disturbance in preeclampsia pathophysiology.

  6. Serum Soluble Corin is Decreased in Stroke.

    Science.gov (United States)

    Peng, Hao; Zhu, Fangfang; Shi, Jijun; Han, Xiujie; Zhou, Dan; Liu, Yan; Zhi, Zhongwen; Zhang, Fuding; Shen, Yun; Ma, Juanjuan; Song, Yulin; Hu, Weidong

    2015-07-01

    Soluble corin was decreased in coronary heart disease. Given the connections between cardiac dysfunction and stroke, circulating corin might be a candidate marker of stroke risk. However, the association between circulating corin and stroke has not yet been studied in humans. Here, we aimed to examine the association in patients wtith stroke and community-based healthy controls. Four hundred eighty-one patients with ischemic stroke, 116 patients with hemorrhagic stroke, and 2498 healthy controls were studied. Serum soluble corin and some conventional risk factors of stroke were examined. Because circulating corin was reported to be varied between men and women, the association between serum soluble corin and stroke was evaluated in men and women, respectively. Patients with ischemic and hemorrhagic stroke had a significantly lower level of serum soluble corin than healthy controls in men and women (all P values, soluble corin were more likely to have ischemic (odds ratio [OR], 4.90; 95% confidence interval, 2.99-8.03) and hemorrhagic (OR, 17.57; 95% confidence interval, 4.85-63.71) stroke than men in the highest quartile. Women in the lowest quartile of serum soluble corin were also more likely to have ischemic (OR, 3.10; 95% confidence interval, 1.76-5.44) and hemorrhagic (OR, 8.54; 95% confidence interval, 2.35-31.02) stroke than women in the highest quartile. ORs of ischemic and hemorrhagic stroke were significantly increased with the decreasing levels of serum soluble corin in men and women (all P values for trend, soluble corin was decreased in patients with stroke compared with healthy controls. Our findings raise the possibility that serum soluble corin may have a pathogenic role in stroke. © 2015 American Heart Association, Inc.

  7. Biorelevant dissolution media: aggregation of amphiphiles and solubility of estradiol.

    Science.gov (United States)

    Ilardia-Arana, David; Kristensen, Henning G; Müllertz, Anette

    2006-02-01

    Biorelevant dissolution media containing bile salt and lecithin at concentrations appropriate for fed and fasted state are useful when testing oral solid formulations of poorly water-soluble drugs. Dilution of amphiphile solutions affects the aggregation state of the amphiphiles because bile salt is partitioned between the aqueous phase and the aggregates. The aim of the investigation was to study the effect of dilution on the size distribution of aggregates and its effect on the solubilization capacity. Clear buffered solutions of four intestinal amphiphiles (sodium glycocholate, lecithin, monoolein, and oleic acid) and a combination of these were prepared at high bile salt concentration. Micelles in the glycocholate solutions decreased in size when diluted. The addition of insoluble amphiphiles led to bigger micelles with no clear correlation between size of the micelles and amphiphile concentration. Dilution of the two- and four component media caused enlargement of the mixed micelles and formation of vesicles. The solubility of estradiol in the buffer solution was increased with addition of the amphiphiles. A good correlation (R(2) = 0.987) was found between estradiol solubility and mass concentration of the amphiphiles. The results demonstrate that, in the case of estradiol, the concentration of amphiphiles rather than the aggregation state determines the solubilization capacity of the medium. Copright 2005 Wiley-Liss, Inc.

  8. Hansen Solubility Parameters for Octahedral Oligomeric Silsesquioxanes

    Science.gov (United States)

    2012-08-28

    and thermal and electrical insulation enhancers. The inorganic core is both mechanically robust, resistant to oxidation, and thermally stable, and...Choi, P.; Kavassalis, T. A.; Rudin, A. Estimation of Hansen Solubility Parameters for (Hydroxyethyl)- Cellulose and (Hydroxypropyl) Cellulose through

  9. Drug solubility classification in the bovine.

    Science.gov (United States)

    Martinez, M N; Apley, M D

    2012-04-01

    Currently, the basis for solubility test conditions and the corresponding solubility criteria is derived from the tremendous wealth of information developed to support human pharmaceutical product development and regulation. However, there are several critical differences between the gastrointestinal tract of ruminants and monogastric species that can affect the conditions and criteria to be applied to the classification of drug solubility in cattle. These include the pH of the stomach, the volume of the stomach, the types of oral formulations, and the definition of 'highest dose'. These points are discussed below and alternative perspectives for consideration with regard to possible modification of solubility criteria for ruminants are presented. © Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

  10. Explaining Ionic Liquid Water Solubility in Terms of Cation and Anion Hydrophobicity

    Science.gov (United States)

    Ranke, Johannes; Othman, Alaa; Fan, Ping; Müller, Anja

    2009-01-01

    The water solubility of salts is ordinarily dictated by lattice energy and ion solvation. However, in the case of low melting salts also known as ionic liquids, lattice energy is immaterial and differences in hydrophobicity largely account for differences in their water solubility. In this contribution, the activity coefficients of ionic liquids in water are split into cation and anion contributions by regression against cation hydrophobicity parameters that are experimentally determined by reversed phase liquid chromatography. In this way, anion hydrophobicity parameters are derived, as well as an equation to estimate water solubilities for cation-anion combinations for which the water solubility has not been measured. Thus, a new pathway to the quantification of aqueous ion solvation is shown, making use of the relative weakness of interactions between ionic liquid ions as compared to their hydrophobicities. PMID:19399248

  11. Explaining ionic liquid water solubility in terms of cation and anion hydrophobicity.

    Science.gov (United States)

    Ranke, Johannes; Othman, Alaa; Fan, Ping; Müller, Anja

    2009-03-01

    The water solubility of salts is ordinarily dictated by lattice energy and ion solvation. However, in the case of low melting salts also known as ionic liquids, lattice energy is immaterial and differences in hydrophobicity largely account for differences in their water solubility. In this contribution, the activity coefficients of ionic liquids in water are split into cation and anion contributions by regression against cation hydrophobicity parameters that are experimentally determined by reversed phase liquid chromatography. In this way, anion hydrophobicity parameters are derived, as well as an equation to estimate water solubilities for cation-anion combinations for which the water solubility has not been measured. Thus, a new pathway to the quantification of aqueous ion solvation is shown, making use of the relative weakness of interactions between ionic liquid ions as compared to their hydrophobicities.

  12. Explaining Ionic Liquid Water Solubility in Terms of Cation and Anion Hydrophobicity

    Directory of Open Access Journals (Sweden)

    Johannes Ranke

    2009-03-01

    Full Text Available The water solubility of salts is ordinarily dictated by lattice energy and ion solvation. However, in the case of low melting salts also known as ionic liquids, lattice energy is immaterial and differences in hydrophobicity largely account for differences in their water solubility. In this contribution, the activity coefficients of ionic liquids in water are split into cation and anion contributions by regression against cation hydrophobicity parameters that are experimentally determined by reversed phase liquid chromatography. In this way, anion hydrophobicity parameters are derived, as well as an equation to estimate water solubilities for cation-anion combinations for which the water solubility has not been measured. Thus, a new pathway to the quantification of aqueous ion solvation is shown, making use of the relative weakness of interactions between ionic liquid ions as compared to their hydrophobicities.

  13. Low Soluble Syndecan-1 Precedes Preeclampsia.

    Directory of Open Access Journals (Sweden)

    Robin E Gandley

    Full Text Available Syndecan-1 (Sdc1; CD138 is a major transmembrane heparan sulfate proteoglycan expressed on the extracellular, luminal surface of epithelial cells and syncytiotrophoblast, thus comprising a major component of the glycocalyx of these cells. The "soluble" (shed form of Sdc1 has paracrine and autocrine functions and is normally produced in a regulated fashion. We compared plasma soluble Sdc1 concentrations, in relation to placental Sdc1 expression, in uncomplicated (control and preeclamptic pregnancies.We evaluated soluble Sdc1 across uncomplicated pregnancy, and between preeclamptic, gestational hypertensive and control patients at mid-pregnancy (20 weeks and 3rd trimester by ELISA. Placental expression level of Sdc1 was compared between groups in relation to pre-delivery plasma soluble Sdc1. Participants were recruited from Magee-Womens Hospital.In uncomplicated pregnancy, plasma soluble Sdc1 rose significantly in the 1st trimester, and reached an approximate 50-fold increase at term compared to post pregnancy levels. Soluble Sdc1 was lower at mid-pregnancy in women who later developed preeclampsia (P<0.05, but not gestational hypertension, compared to controls, and remained lower at late pregnancy in preeclampsia (P<0.01 compared to controls. Sdc1 was prominently expressed on syncytiotrophoblast of microvilli. Syncytiotrophoblast Sdc1 immunostaining intensities, and mRNA content in villous homogenates, were lower in preeclampsia vs. controls (P<0.05. Soluble Sdc1 and Sdc1 immunostaining scores were inversely associated with systolic blood pressures, and positively correlated with infant birth weight percentile.Soluble Sdc1 is significantly lower before the clinical onset of preeclampsia, with reduced expression of Sdc1 in the delivered placenta, suggesting a role for glycocalyx disturbance in preeclampsia pathophysiology.

  14. Solubility Products of M(II) - Carbonates

    Energy Technology Data Exchange (ETDEWEB)

    Grauer, Rolf; Berner, Urs [ed.

    1999-01-01

    Many solubility data for M(II) carbonates commonly compiled in tables are contradictory and sometimes obviously wrong. The quality of such data has been evaluated based on the original publications and reliable solubility constants have been selected for the carbonates of Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb with the help of cross-comparisons. (author) translated from a PSI internal report written in German in 1994 (TM-44-94-05). 5 figs., 1 tab., 68 refs.

  15. Modeling dissolution of sparingly soluble multisized powders

    OpenAIRE

    Almeida, Luís Pereira de; Simões, Sérgio; Brito, Paulo; Portugal, António; Figueiredo, Margarida

    1997-01-01

    The dissolution of powder drugs, besides being a topic of utmost importance, especially for the sparingly soluble ones, is far from being well-explained. The purpose of the present study is, on the one hand, to obtain experimental dissolution profiles and, on the other hand, to analyze and process the data for dissolution modeling. Three different size fractions of a widely used sparingly soluble drug - ibuprofen - were fully characterized with regard to its particle size distribution, specif...

  16. Correlation of Helium Solubility in Liquid Nitrogen

    Science.gov (United States)

    VanDresar, Neil T.; Zimmerli, Gregory A.

    2012-01-01

    A correlation has been developed for the equilibrium mole fraction of soluble gaseous helium in liquid nitrogen as a function of temperature and pressure. Experimental solubility data was compiled and provided by National Institute of Standards and Technology (NIST). Data from six sources was used to develop a correlation within the range of 0.5 to 9.9 MPa and 72.0 to 119.6 K. The relative standard deviation of the correlation is 6.9 percent.

  17. How Soluble GARP Enhances TGFβ Activation.

    Directory of Open Access Journals (Sweden)

    Sven Fridrich

    Full Text Available GARP (glycoprotein A repetitions predominant is a cell surface receptor on regulatory T-lymphocytes, platelets, hepatic stellate cells and certain cancer cells. Its described function is the binding and accommodation of latent TGFβ (transforming growth factor, before the activation and release of the mature cytokine. For regulatory T cells it was shown that a knockdown of GARP or a treatment with blocking antibodies dramatically decreases their immune suppressive capacity. This confirms a fundamental role of GARP in the basic function of regulatory T cells. Prerequisites postulated for physiological GARP function include membrane anchorage of GARP, disulfide bridges between the propeptide of TGFβ and GARP and connection of this propeptide to αvβ6 or αvβ8 integrins of target cells during mechanical TGFβ release. Other studies indicate the existence of soluble GARP complexes and a functionality of soluble GARP alone. In order to clarify the underlying molecular mechanism, we expressed and purified recombinant TGFβ and a soluble variant of GARP. Surprisingly, soluble GARP and TGFβ formed stable non-covalent complexes in addition to disulfide-coupled complexes, depending on the redox conditions of the microenvironment. We also show that soluble GARP alone and the two variants of complexes mediate different levels of TGFβ activity. TGFβ activation is enhanced by the non-covalent GARP-TGFβ complex already at low (nanomolar concentrations, at which GARP alone does not show any effect. This supports the idea of soluble GARP acting as immune modulator in vivo.

  18. Chromatographic determination of solubilities in superheated water.

    Science.gov (United States)

    Jones, Neil; Clifford, Anthony A; Bartle, Keith D; Myers, Peter

    2010-10-01

    Superheated water (SHW) is an effective solvent for the extraction of a variety of environmental pollutants, but knowledge of the solubilities in water at elevated temperatures necessary to maximise the efficiency of the process is often lacking. Ambient temperature aqueous solubilities have been measured by reverse-phase HPLC from correlations with retention factors, k, but for poorly soluble organics the eluent must contain a proportion of organic modifier followed by extrapolation to pure water. The use of SHW as mobile phase allows direct determination of aqueous solubility from measurement of k on a modified HPLC system in which the eluent is cooled before detection to improve baseline stability. Alumina-bonded octadecylsilane columns were found to be more stable in SHW chromatography than their silica-bonded counterparts. To validate the procedure, measurements of k were made between 100 and 200°C for toluene and correlated with literature solubilities; the solubilities at 170°C of a number of related aromatics were then determined from their k-values.

  19. Solubility of paroxetine hydrochloride hemi-hydrate in (water + acetone)

    Energy Technology Data Exchange (ETDEWEB)

    Ren Guobin [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China)]. E-mail: renguobin2557@sohu.com; Wang Jingkang [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Li Guizhi [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China)

    2005-08-15

    Using a laser monitoring observation technique, the solubilities of paroxetine hydrochloride hemi-hydrate in (water + acetone) were determined by the synthetic method from (294.45 to 323.20) K, respectively. Results of these measurements were correlated by the three variants of the combined nearly ideal binary solvent/Redlich-Kister (CNIBS/R-K) model. For the seven group data studied, three variants of the (CNIBS/R-K) equation were found to provide accurate mathematical representations of the experimental data and variant 2 is the best of the three variants.

  20. Cocrystal Transition Points: Role of Cocrystal Solubility, Drug Solubility, and Solubilizing Agents.

    Science.gov (United States)

    Lipert, Maya P; Rodríguez-Hornedo, Naír

    2015-10-05

    In this manuscript we bring together concepts that are relevant to the solubilization and thermodynamic stability of cocrystals in the presence of drug solubilizing agents. Simple equations are derived that allow calculation of cocrystal solubilization and transition point solubility. Analysis of 10 cocrystals in 6 different solubilizing agents shows that cocrystal solubilization is quantitatively predicted from drug solubilization. Drug solubilizing agents such as surfactants and lipid-based media are also shown to induce cocrystal transition points, where drug and cocrystal solubilities are equal, and above which the cocrystal solubility advantage over drug is eliminated. We have discovered that cocrystal solubility at the transition point (S*) is independent of solubilizing agent, and can be predicted from knowledge of only the aqueous solubilities of drug and cocrystal. For 1:1 cocrystals, S* = (Scocrystal,aq)(2)/Sdrug,aq. S* is a key indicator of cocrystal thermodynamic stability and establishes the upper solubility limit below which cocrystal is more soluble than the constituent drug. These findings have important implications to tailor cocrystal solubility and stability in pharmaceutical formulations from commonly available drug solubility descriptors.

  1. Redefining solubility parameters: the partial solvation parameters.

    Science.gov (United States)

    Panayiotou, Costas

    2012-03-21

    The present work reconsiders a classical and universally accepted concept of physical chemistry, the solubility parameter. Based on the insight derived from modern quantum chemical calculations, a new definition of solubility parameter is proposed, which overcomes some of the inherent restrictions of the original definition and expands its range of applications. The original single solubility parameter is replaced by four partial solvation parameters reflecting the dispersion, the polar, the acidic and the basic character of the chemical compounds as expressed either in their pure state or in mixtures. Simple rules are adopted for the definition and calculation of these four parameters and their values are tabulated for a variety of common substances. In contrast, however, to the well known Hansen solubility parameters, their design and evaluation does not rely exclusively on the basic rule of "similarity matching" for solubility but it makes also use of the other basic rule of compatibility, namely, the rule of "complementarity matching". This complementarity matching becomes particularly operational with the sound definition of the acidic and basic components of the solvation parameter based on the third σ-moments of the screening charge distributions of the quantum mechanics-based COSMO-RS theory. The new definitions are made in a simple and straightforward manner, thus, preserving the strength and appeal of solubility parameter stemming from its simplicity. The new predictive method has been applied to a variety of solubility data for systems of pharmaceuticals and polymers. The results from quantum mechanics calculations are critically compared with the results from Abraham's acid/base descriptors.

  2. Ultrasound influence on the solubility of solid dispersions prepared for a poorly soluble drug.

    Science.gov (United States)

    Pereira, Simone Vieira; Colombo, Fábio Belotti; de Freitas, Luis Alexandre Pedro

    2016-03-01

    Solid dispersions have been successfully used to enhance the solubility of several poorly water soluble drugs. Solid dispersions are produced by melting hydrophilic carriers and mixing in the poorly water soluble drug. Supersaturation is obtained by quickly cooling the mixture until it solidifies, thereby entrapping the drug. The effects of using ultrasound to homogenize the molten carrier and drug mixture were studied. In particular, the increase in drug solubility for the resulting solid dispersions was analyzed. Piroxicam, which has very low water solubility, was used as a model drug. A full factorial design was used to analyze how sonication parameters affected the solubility and in vitro release of the drug. The results show that the use of ultrasound can significantly increase the solubility and dissolution rate of the piroxicam solid dispersion. Pure piroxicam presented a solubility of 13.3 μg/mL. A maximum fourfold increase in solubility, reaching 53.8 μg/mL, was observed for a solid dispersion sonicated at 19 kHz for 10 min and 475 W. The in vitro dissolution rate test showed the sonicated solid dispersion reached a maximum rate of 18%/min, a sixfold increase over the piroxicam rate of 2.9%/min. Further solid state characterization by thermal, X-ray diffraction and Fourier transform infrared analyses also showed that the sonication process, in the described conditions, did not adversely alter the drug or significantly change its polymorphic form. Ultrasound is therefore an interesting technique to homogenize drug/carrier mixtures with the objective of increasing the solubility of drugs with poor water solubility. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Dual Level Statistical Investigation of Equilibrium Solubility in Simulated Fasted and Fed Intestinal Fluid.

    Science.gov (United States)

    Ainousah, Bayan E; Perrier, Jeremy; Dunn, Claire; Khadra, Ibrahim; Wilson, Clive G; Halbert, Gavin

    2017-12-04

    The oral route is the preferred option for drug administration but contains the inherent issue of drug absorption from the gastro-intestinal tract (GIT) in order to elicit systemic activity. A prerequisite for absorption is drug dissolution, which is dependent upon drug solubility in the variable milieu of GIT fluid, with poorly soluble drugs presenting a formulation and biopharmaceutical challenge. Multiple factors within GIT fluid influence solubility ranging from pH to the concentration and ratio of amphiphilic substances, such as phospholipid, bile salt, monoglyceride, and cholesterol. To aid in vitro investigation simulated intestinal fluids (SIF) covering the fasted and fed state have been developed. SIF media is complex and statistical design of experiment (DoE) investigations have revealed the range of solubility values possible within each state due to physiological variability along with the media factors and factor interactions which influence solubility. However, these studies require large numbers of experiments (>60) and are not feasible or sensible within a drug development setting. In the current study a smaller dual level, reduced experimental number (20) DoE providing three arms covering the fasted and fed states along with a combined analysis has been investigated. The results indicate that this small scale investigation is feasible and provides solubility ranges that encompass published data in human and simulated fasted and fed fluids. The measured fasted and fed solubility ranges are in agreement with published large scale DoE results in around half of the cases, with the differences due to changes in media composition between studies. Indicating that drug specific behaviors are being determined and that careful media factor and concentration level selection is required in order to determine a physiologically relevant solubility range. The study also correctly identifies the major single factor or factors which influence solubility but it is

  4. Statistical investigation of simulated fed intestinal media composition on the equilibrium solubility of oral drugs.

    Science.gov (United States)

    Zhou, Zhou; Dunn, Claire; Khadra, Ibrahim; Wilson, Clive G; Halbert, Gavin W

    2017-03-01

    Gastrointestinal fluid is a complex milieu and it is recognised that gut drug solubility is different to that observed in simple aqueous buffers. Simulated gastrointestinal media have been developed covering fasted and fed states to facilitate in vitro prediction of gut solubility and product dissolution. However, the combination of bile salts, phospholipids, fatty acids and proteins in an aqueous buffered system creates multiple phases and drug solubility is therefore a complex interaction between these components, which may create unique environments for each API. The impact on solubility can be assessed through a statistical design of experiment (DoE) approach, to determine the influence and relationships between factors. In this paper DoE has been applied to fed simulated gastrointestinal media consisting of eight components (pH, bile salt, lecithin, sodium oleate, monoglyceride, buffer, salt and pancreatin) using a two level D-optimal design with forty-four duplicate measurements and four centre points. The equilibrium solubility of a range of poorly soluble acidic (indomethacin, ibuprofen, phenytoin, valsartan, zafirlukast), basic (aprepitant, carvedilol, tadalafil, bromocriptine) and neutral (fenofibrate, felodipine, probucol, itraconazole) drugs was investigated. Results indicate that the DoE provides equilibrium solubility values that are comparable to literature results for other simulated fed gastrointestinal media systems or human intestinal fluid samples. For acidic drugs the influence of pH predominates but other significant factors related to oleate and bile salt or interactions between them are present. For basic drugs pH, oleate and bile salt have equal significance along with interactions between pH and oleate and lecithin and oleate. Neutral drugs show diverse effects of the media components particularly with regard to oleate, bile salt, pH and lecithin but the presence of monoglyceride, pancreatin and buffer have significant but smaller effects

  5. Ionization, lipophilicity and solubility properties of repaglinide.

    Science.gov (United States)

    Mandić, Zoran; Gabelica, Vesna

    2006-06-07

    Potentiometric and spectrophotometric titrations were used for the determination of ionization behaviour, lipophilicity and solubility profile of repaglinide. Acid-base equilibria were characterized by means of protonation macro- and microconstants using Target Factor Analysis of spectrophotometric data. Lipophilicity profiles were evaluated by determination of partition coefficients of neutral and ionized forms of repaglinide in biphasic octanol/water system. The intrinsic solubilities of repaglinide were determined from the solubility data and temperature dependence of intrinsic solubilities were evaluated using van't Hoff equation. Repaglinide possesses two protonation sites and in aqueous solutions exhibits ampholitic properties. At isoelectric pH the zwitterionic form of the molecule predominates over the uncharged form with the tautomeric ratio, logKz=1.9. The difference between calculated and measured logP values, as well as the difference between logP values of uncharged form of repaglinide, HR0, and either one of mono-charged forms indicated the significant partition of zwitterion into octanol. Temperature dependence of solubility data revealed exothermic dissolution process with DeltasolH=-36 kJmol-1 and negative entropy of solution of DeltasolS=-0.19 kJK-1mol-1.

  6. Extraction and analysis of soluble carbohydrates.

    Science.gov (United States)

    Maness, Niels

    2010-01-01

    Soluble sugars are a universal component of most living organisms and a fundamental building block in biosynthetic processes. It is no wonder that both qualitative and quantitative changes in carbohydrates often accompany plant's responses to stress. Depending on the speed of onset of stress, plant tissues can exhibit rapid and very site-specific shifts in their soluble carbohydrate pool - rapid and precise tissue collection and stabilization are necessary if analytical results are to truly represent the sugar composition at the instant of harvest. Since soluble carbohydrates are, by definition, soluble in the cell's aqueous environment, they may be analyzed directly from liquids obtained from plants or they may require extraction from the plant matrix. During extraction and prior to analysis, steps should be taken to avoid change in form or quantity of sugars by endogenous active enzyme conversion or by contaminating microbial growth. Many procedures for soluble sugar analysis exist; the choice of the most appropriate analytical protocol is ultimately dictated by the depth of information required to substantiate findings for a particular purpose.

  7. Melt extrusion with poorly soluble drugs.

    Science.gov (United States)

    Shah, Sejal; Maddineni, Sindhuri; Lu, Jiannan; Repka, Michael A

    2013-08-30

    Melt extrusion (ME) over recent years has found widespread application as a viable drug delivery option in the drug development process. ME applications include taste masking, solid-state stability enhancement, sustained drug release and solubility enhancement. While ME can result in amorphous or crystalline solid dispersions depending upon several factors, solubility enhancement applications are centered around generating amorphous dispersions, primarily because of the free energy benefits they offer. In line with the purview of the current issue, this review assesses the utility of ME as a means of enhancing solubility of poorly soluble drugs/chemicals. The review describes major processing aspects of ME technology, definition and understanding of the amorphous state, manufacturability, analytical characterization and biopharmaceutical performance testing to better understand the strength and weakness of this formulation strategy for poorly soluble drugs. In addition, this paper highlights the potential advantages of employing a fusion of techniques, including pharmaceutical co-crystals and spray drying/solvent evaporation, facilitating the design of formulations of API exhibiting specific physico-chemical characteristics. Finally, the review presents some successful case studies of commercialized ME based products. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. 40 CFR Table 7 to Subpart Vvvvvv... - Partially Soluble HAP

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 14 2010-07-01 2010-07-01 false Partially Soluble HAP 7 Table 7 to... Pt. 63, Subpt. VVVVVV, Table 7 Table 7 to Subpart VVVVVV of Part 63—Partially Soluble HAP As required... partially soluble HAP listed in the following table. Partially soluble HAP name CAS No. 1. 1,1,1...

  9. In situ determination of the saturation solubility of nanocrystals of poorly soluble drugs for dermal application.

    Science.gov (United States)

    Colombo, Miriam; Staufenbiel, Sven; Rühl, Eckart; Bodmeier, Roland

    2017-04-15

    The aim of this study was to determine, in situ, the saturation solubility and dissolution rate of nanocrystals of three poorly water-soluble drugs for dermal application. The nanocrystals were prepared by wet bead milling. Their size could be controlled by various process parameters. The saturation solubility was measured in water or in the presence of surfactant at 32°C with a Sirius ® inForm based on in situ UV-vis spectroscopy. The saturation solubility of nanocrystals with sizes of ∼300nm increased for each drug in comparison to non-milled drug powders, with factors of increase in the range 1.3-2.8. The tacrolimus solubility was further analyzed with excess nanocrystal amounts four and ten times higher than the drug powder solubility. The corresponding solubility increases were 2.8 and 6.6 and thus dependent on the amount of excess nanocrystals. The higher increase was due to the presence of a larger fraction of small size particles, and only crystals far below 1μm showed supersaturation. The solubility increase for nanocrystals determined in situ was remarkably lower than the one previously reported with the use of non in situ methods. Nanomilling increased the drug dissolution rates: the highest increase was obtained with ibuprofen (rate increase ∼30). Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Influence of Polymer Molecular Weight on Drug-Polymer Solubility: A Comparison between Experimentally Determined Solubility in PVP and Prediction Derived from Solubility in Monomer.

    Science.gov (United States)

    Knopp, Matthias Manne; Olesen, Niels Erik; Holm, Per; Langguth, Peter; Holm, René; Rades, Thomas

    2015-09-01

    In this study, the influence of polymer molecular weight on drug-polymer solubility was investigated using binary systems containing indomethacin (IMC) and polyvinylpyrrolidone (PVP) of different molecular weights. The experimental solubility in PVP, measured using a differential scanning calorimetry annealing method, was compared with the solubility calculated from the solubility of the drug in the liquid analogue N-vinylpyrrolidone (NVP). The experimental solubility of IMC in the low-molecular-weight PVP K12 was not significantly different from that in the higher molecular weight PVPs (K25, K30, and K90). The calculated solubilities derived from the solubility in NVP (0.31-0.32 g/g) were found to be lower than those experimentally determined in PVP (0.38-0.40 g/g). Nevertheless, the similarity between the values indicates that the analogue solubility can provide valuable indications on the solubility in the polymer. Hence, if a drug is soluble in an analogue of the polymer, it is most likely also soluble in the polymer. In conclusion, the solubility of a given drug-polymer system is determined by the strength of the drug-polymer interactions rather than the molecular weight of the polymer. Therefore, during the first screenings for drug solubility in polymers, only one representative molecular weight per polymer is needed. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  11. Production and cytotoxicity of extracellular insoluble and droplets of soluble melanin by Streptomyces lusitanus DMZ-3.

    Science.gov (United States)

    Madhusudhan, D N; Mazhari, Bi Bi Zainab; Dastager, Syed G; Agsar, Dayanand

    2014-01-01

    A Streptomyces lusitanus DMZ-3 strain with potential to synthesize both insoluble and soluble melanins was detected. Melanins are quite distinguished based on their solubility for varied biotechnological applications. The present investigation reveals the enhanced production of insoluble and soluble melanins in tyrosine medium by a single culture. Streptomyces lusitanus DMZ-3 was characterized by 16S rRNA gene analysis. An enhanced production of 5.29 g/L insoluble melanin was achieved in a submerged bioprocess following response surface methodology. Combined interactive effect of temperature (50°C), pH (8.5), tyrosine (2.0 g/L), and beef extract (0.5 g/L) were found to be critical variables for enhanced production in central composite design analysis. An optimized indigenous slant culture system was an innovative approach for the successful production (264 mg/L) of pure soluble melanin from the droplets formed on the surface of the culture. Both insoluble and soluble melanins were confirmed and characterized by Chemical, reactions, UV, FTIR, and TLC analysis. First time, cytotoxic study of melanin using brine shrimps was reported. Maximum cytotoxic activity of soluble melanin was Lc50-0.40 µg/mL and insoluble melanin was Lc50-0.80 µg/mL.

  12. Production and Cytotoxicity of Extracellular Insoluble and Droplets of Soluble Melanin by Streptomyces lusitanus DMZ-3

    Directory of Open Access Journals (Sweden)

    D. N. Madhusudhan

    2014-01-01

    Full Text Available A Streptomyces lusitanus DMZ-3 strain with potential to synthesize both insoluble and soluble melanins was detected. Melanins are quite distinguished based on their solubility for varied biotechnological applications. The present investigation reveals the enhanced production of insoluble and soluble melanins in tyrosine medium by a single culture. Streptomyces lusitanus DMZ-3 was characterized by 16S rRNA gene analysis. An enhanced production of 5.29 g/L insoluble melanin was achieved in a submerged bioprocess following response surface methodology. Combined interactive effect of temperature (50°C, pH (8.5, tyrosine (2.0 g/L, and beef extract (0.5 g/L were found to be critical variables for enhanced production in central composite design analysis. An optimized indigenous slant culture system was an innovative approach for the successful production (264 mg/L of pure soluble melanin from the droplets formed on the surface of the culture. Both insoluble and soluble melanins were confirmed and characterized by Chemical, reactions, UV, FTIR, and TLC analysis. First time, cytotoxic study of melanin using brine shrimps was reported. Maximum cytotoxic activity of soluble melanin was Lc50-0.40 µg/mL and insoluble melanin was Lc50-0.80 µg/mL.

  13. Gaseous Sulfate Solubility in Glass: Experimental Method

    Energy Technology Data Exchange (ETDEWEB)

    Bliss, Mary [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-11-30

    Sulfate solubility in glass is a key parameter in many commercial glasses and nuclear waste glasses. This report summarizes key publications specific to sulfate solubility experimental methods and the underlying physical chemistry calculations. The published methods and experimental data are used to verify the calculations in this report and are expanded to a range of current technical interest. The calculations and experimental methods described in this report will guide several experiments on sulfate solubility and saturation for the Hanford Waste Treatment Plant Enhanced Waste Glass Models effort. There are several tables of sulfate gas equilibrium values at high temperature to guide experimental gas mixing and to achieve desired SO3 levels. This report also describes the necessary equipment and best practices to perform sulfate saturation experiments for molten glasses. Results and findings will be published when experimental work is finished and this report is validated from the data obtained.

  14. A framework for API solubility modelling

    DEFF Research Database (Denmark)

    Conte, Elisa; Gani, Rafiqul; Crafts, Peter

    . In addition, most of the models are not predictive and requires experimental data for the calculation of the needed parameters. This work aims at developing an efficient framework for the solubility modelling of Active Pharmaceutical Ingredients (API) in water and organic solvents. With this framework......-SAFT) are used for solubility calculations when the needed interaction parameters or experimental data are available. The CI-UNIFAC is instead used when the previous models lack interaction parameters or when solubility data are not available. A new GC+ model for APIs solvent selection based...... on the hydrophobicity, hydrophilicity and polarity information of the API and solvent is also developed, for performing fast solvent selection and screening. Eventually, all the previous developments are integrated in a framework for their efficient and integrated use. Two case studies are presented: the first...

  15. Equilibrium Solubility of CO2 in Alkanolamines

    DEFF Research Database (Denmark)

    Waseem Arshad, Muhammad; Fosbøl, Philip Loldrup; von Solms, Nicolas

    2014-01-01

    Equilibrium solubility of CO2 were measured in aqueous solutions of Monoethanolamine (MEA) and N,N-diethylethanolamine(DEEA). Equilibrium cells are generally used for these measurements. In this study, the equilibrium data were measured from the calorimetry. For this purpose a reaction calorimeter...... (model CPA 122 from ChemiSens AB, Sweden) was used. The advantage of this method is being the measurement of both heats of absorption and equilibrium solubility data of CO2 at the same time. The measurements were performed for 30 mass % MEA and 5M DEEA solutions as a function of CO2 loading at three...... different temperatures 40, 80 and 120 ºC. The measured 30 mass % MEA and 5M DEEA data were compared with the literature data obtained from different equilibrium cells which validated the use of calorimeters for equilibrium solubility measurements....

  16. Soluble Mediators Regulating Immunity in Early Life

    Directory of Open Access Journals (Sweden)

    Matthew Aaron Pettengill

    2014-09-01

    Full Text Available Soluble factors in blood plasma have a substantial impact on both the innate and adaptive immune responses. The complement system, antibodies, and antimicrobial proteins and peptides (APPs, can directly interact with potential pathogens, protecting against systemic infection. The extracellular environment also has a critical influence on immune cell maturation, activation, and effector functions, and many of the factors in plasma, including hormones, vitamins, and purines, have been shown to influence these processes for leukocytes of both the innate and adaptive immune systems. In this review we give particular consideration to soluble mediators in plasma for which age-dependent differences in abundance may influence the ontogeny of immune function.

  17. Cyclic Glucans Enhance Solubility of Bioavailable Flavonoids

    Directory of Open Access Journals (Sweden)

    Seyeon Park

    2016-11-01

    Full Text Available Diverse flavonoids are abundant in dietary food constituents and possess useful biological activities. However, some flavonoids have limited bioavailability due to their low solubility in water. As an important approach to enhance aqueous solubility, inclusion of hydrophobic guest molecules in hydrophilic hosts such as cyclic glucans has been used. This review summarizes applications of β-cyclodextrin, synthetic β-cyclodextrin derivatives, and newly synthesized derivatives of cyclosophoraoses as complexing agents to enhance the bioavailability of flavonoids such as baicalein, kaempferol, and naphthoflavones.

  18. AN-107 entrained solids - Solubility versus temperature

    Energy Technology Data Exchange (ETDEWEB)

    GJ Lumetta; RC Lettau

    2000-03-31

    This report describes the results of a test conducted by Battelle to assess the solubility of the solids entrained in the diluted AN-107 low-activity waste (LAW) sample. BNFL requested Battelle to dilute the AN-107 sample using sodium hydroxide and de-ionized water to mimic expected plant operating conditions. BNFL further requested Battelle to assess the solubility of the solids present in the diluted AN-107 sample versus temperature conditions of 30, 40, and 50 C. BNFL requested these tests to assess the composition of the LAW supernatant and solids versus expected plant-operating conditions.

  19. Modeling of Salt Solubilities in Mixed Solvents

    DEFF Research Database (Denmark)

    Chiavone-Filho, O.; Rasmussen, Peter

    2000-01-01

    constants and the liquid densities of the solvent media. To normalize the activity coefficients, the symmetric convention is adopted. Thermochemical properties of the salt are used to estimate the solubility product. It is shown that the proposed procedure can describe with good accuracy a series of salt......A method to correlate and predict salt solubilities in mixed solvents using a UNIQUAC+Debye-Huckel model is developed. The UNIQUAC equation is applied in a form with temperature-dependent parameters. The Debye-Huckel model is extended to mixed solvents by properly evaluating the dielectric...

  20. Microfluidic platform with four orthogonal and overlapping gradients for soluble compound screening in regenerative medicine research

    NARCIS (Netherlands)

    Harink, Björn; le Gac, Severine; Baiao Barata, David; van Blitterswijk, Clemens; Habibovic, Pamela

    We present here a screening method based on a microfluidic platform, which can generate four orthogonal and overlapping concentration gradients of soluble compounds over a monolayer of cells, in combination with automated and in situ image analysis, for use in regenerative medicine research. The

  1. MISCIBILITY, SOLUBILITY, VISCOSITY, AND DENSITY MEASUREMENTS FOR R-236FA WITH POTENTIAL LUBRICANTS

    Science.gov (United States)

    The report gives results of miscibility, solubility, viscosity, and density measurements for refrigerant R-236fa and two potential lubricants . (The data are needed to determine the suitability of refrigerant/lubricant combinations for use in refrigeration systems.) The tested oi...

  2. Photocatalytic hydrogen production from a simple water-soluble [FeFe]-hydrogenase model system.

    Science.gov (United States)

    Cao, Wei-Ning; Wang, Feng; Wang, Hong-Yan; Chen, Bin; Feng, Ke; Tung, Chen-Ho; Wu, Li-Zhu

    2012-08-21

    Combined with a simple water soluble [FeFe]-hydrogenase mimic 1, Ru(bpy)(3)(2+) and ascorbic acid enable hydrogen production photocatalytically. More than 88 equivalents of H(2) were achieved in water, which is much better than that obtained in an organic solvent or a mixture of organic solvent and water.

  3. Water-soluble plasmonic nanosensors with synthetic receptors for label-free detection of folic acid.

    Science.gov (United States)

    Ahmad, Randa; Félidj, Nordin; Boubekeur-Lecaque, Leïla; Lau-Truong, Stéphanie; Gam-Derouich, Sarra; Decorse, Philippe; Lamouri, Aazdine; Mangeney, Claire

    2015-06-14

    We describe an original approach to graft molecularly imprinted polymers around gold nanorods by combining the diazonium salt chemistry and the iniferter method. This chemical strategy enables fine control of the imprinting process at the nanometer scale and provides water-soluble plasmonic nanosensors.

  4. Soluble interleukin 2 receptor in atopic eczema.

    Science.gov (United States)

    Colver, G. B.; Symons, J. A.; Duff, G. W.

    1989-01-01

    OBJECTIVE--To determine whether serum soluble interleukin 2 receptor concentrations are related to disease activity in atopic eczema. DESIGN--Single cohort longitudinal study with controls. SETTING--Outpatient and general medicine departments in secondary referral centre. PATIENTS--Of 15 patients aged 17-57 with severe atopic eczema, all with acute exacerbations of disease, 13 were admitted to hospital and two treated as outpatients until the skin lesions had resolved or greatly improved. Nineteen controls gave single blood samples. INTERVENTIONS--Daily skin dressing with betamethasone valerate (0.025%) and ichthammol paste and tubular dressings. END POINT--Resolution of or considerable improvement in skin lesions. MEASUREMENTS AND MAIN RESULTS--Enzyme linked immunosorbent assays (ELISA) were used to measure serum soluble interleukin 2 receptor concentrations in blood samples taken on admission, at intervals subsequently, and on discharge. Clinical scores of disease activity were also made. Median concentrations on admission were significantly higher (770 U/ml) in the patients than the controls (300 U/ml). Concentrations fell significantly during treatment. In 25 assessments made at different times in 13 patients serum soluble interleukin 2 receptor concentration correlated significantly (R = 0.73) with clinical disease activity. CONCLUSIONS--Cellular immunopathogenic mechanisms contribute to atopic eczema. Immune activation can be measured in atopic eczema by measurements of soluble interleukin 2 receptor, and this should facilitate assessment of response to treatment. PMID:2568868

  5. Lipid Lowering with Soluble Dietary Fiber.

    Science.gov (United States)

    Surampudi, Prasanth; Enkhmaa, Byambaa; Anuurad, Erdembileg; Berglund, Lars

    2016-12-01

    Consumption of dietary soluble fibers has been associated with health benefits such as reduced lipid levels, lower blood pressure, improved blood glucose control, weight loss, improved immune function, and reduced inflammation. Many of these health benefits relate to a reduced risk of developing cardiovascular disease. In this paper, we have reviewed recent studies on the hypocholesterolemic effects of dietary soluble fibers as well as fiber-rich foods. Findings include the following: (a) consumption of water-soluble, viscous-forming fibers can reduce total and low-density lipoprotein cholesterol levels by about 5-10 %; (b) minimal changes of high-density lipoprotein cholesterol or triglyceride levels were observed; (c) cholesterol-lowering properties of soluble fibers depend on their physical and chemical properties; and (d) medium to high molecular weight fibers are more effective in reducing lipid levels. Hypocholesterolemic benefits were also observed with some fiber-rich foods, such as whole oats, whole barley, legumes, peas, beans, flax seeds, apples, and citrus foods.

  6. Molecular Thermodynamic Modeling of Mixed Solvent Solubility

    DEFF Research Database (Denmark)

    Ellegaard, Martin Dela; Abildskov, Jens; O’Connell, John P.

    2010-01-01

    A method based on statistical mechanical fluctuation solution theory for composition derivatives of activity coefficients is employed for estimating dilute solubilities of 11 solid pharmaceutical solutes in nearly 70 mixed aqueous and nonaqueous solvent systems. The solvent mixtures range from ne...

  7. Changes in protein solubility, fermentative capacity, viscoelasticity ...

    African Journals Online (AJOL)

    The use of frozen dough remedied availability of fresh bread. However, bread elaborated from frozen dough has less volume and texture is firmer. This study evaluates how storage affects the protein solubility, fermentative capacity and viscoelasticity of frozen dough. In addition to examining the effects of storage on the ...

  8. Anomalous Solubility Behavior of Several Acidic Drugs

    Directory of Open Access Journals (Sweden)

    Alex Avdeef

    2014-04-01

    Full Text Available The “anomalous solubility behavior at higher pH values” of several acidic drugs originally studied by Higuchi et al. in 1953 [1], but hitherto not fully rationalized, has been re-analyzed using a novel solubility-pH analysis computer program, pDISOL-XTM. The program internally derives implicit solubility equations, given a set of proposed equilibria and constants (iteratively refined by weighted nonlinear regression, and does not require explicit Henderson-Hasselbalch equations. The re-analyzed original barbital, phenobarbital, oxytetracycline, and sulfathiazole solubility-pH data of Higuchi et al. is consistent with the presence of dimers in saturated solutions. In the case of barbital, phenobarbital and sulfathiazole, anionic dimers, reaching peak concentrations near pH 8. However, oxytetracycline indicated a pronounced tendency to form a cationic dimer, peaking near pH 2. Under the conditions of the original study, only barbital indicated a slight tendency to form a salt precipitate at pH > 6.8, with a highly unusual stoichiometry (consistent with a slope of 0.55 in the log S – pH plot: K+ + A2H- + 3HA D KA5H4(s. Thus the “anomaly” in the Higuchi data can be rationalized by invoking specific aggregated species.

  9. In vitro gas and volatile fatty acids production profiles of barley and maize and their soluble and washout fractions after feed processing

    NARCIS (Netherlands)

    Yang, H.J.; Tamminga, S.; Williams, B.A.; Dijkstra, J.; Boer, H.

    2005-01-01

    In vitro fermentation characteristics of soluble, washout, and non-washout fractions separated from barley and maize and their technologically processed (i.e., pressure toasting, pelleting and their combination) products were measured. The aim was to establish whether the soluble equaled the washout

  10. Scoring function to predict solubility mutagenesis

    Directory of Open Access Journals (Sweden)

    Deutsch Christopher

    2010-10-01

    Full Text Available Abstract Background Mutagenesis is commonly used to engineer proteins with desirable properties not present in the wild type (WT protein, such as increased or decreased stability, reactivity, or solubility. Experimentalists often have to choose a small subset of mutations from a large number of candidates to obtain the desired change, and computational techniques are invaluable to make the choices. While several such methods have been proposed to predict stability and reactivity mutagenesis, solubility has not received much attention. Results We use concepts from computational geometry to define a three body scoring function that predicts the change in protein solubility due to mutations. The scoring function captures both sequence and structure information. By exploring the literature, we have assembled a substantial database of 137 single- and multiple-point solubility mutations. Our database is the largest such collection with structural information known so far. We optimize the scoring function using linear programming (LP methods to derive its weights based on training. Starting with default values of 1, we find weights in the range [0,2] so that predictions of increase or decrease in solubility are optimized. We compare the LP method to the standard machine learning techniques of support vector machines (SVM and the Lasso. Using statistics for leave-one-out (LOO, 10-fold, and 3-fold cross validations (CV for training and prediction, we demonstrate that the LP method performs the best overall. For the LOOCV, the LP method has an overall accuracy of 81%. Availability Executables of programs, tables of weights, and datasets of mutants are available from the following web page: http://www.wsu.edu/~kbala/OptSolMut.html.

  11. Tantalum solubility in simulant lung fluid

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Cintia; Leite, Carlos V.B. [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), Rio de janeiro, RJ (Brazil). Dept. de Fisica]. E-mail: cintia@vdg.fis.puc-rio.br; Dalia, Kely C.P. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Coelho, Maysa [Instituto Militar de Engenharia IME, Rio de Janeiro, RJ (Brazil); Medeiros, Geiza; Santos, Maristela; Cunha, Kenya Dias da [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)]. E-mail: kenya@ird.gov.br

    2007-07-01

    The aim of this study is to determine the solubility rate of tantalum contained in pyrochlore, columbite-tantalite and columbite in simulant lung fluid. The International Commission on Radiological Protection (ICRP) in its recommendation for limiting intakes of radionuclide by workers has consistently recognized that the biological behavior of any specific material after incorporation can significantly diverge from model prevision. Model parameters should be adjusted to adapt the model for each specific substance material in order to estimate the dose due to this element intake. The most recent ICRP respiratory tract dosimetry model gives information about the specific material, as data like particle size, aerosols solubility and the material chemical compounds are important parameters in the dose coefficients calculation. This paper studies the solubility in Simulant Lung Fluid (SLF) of Ta present in mineral dust particles. For this study 3 minerals were selected: pyrochlore, columbite-tantalite and columbite. Tantalum dissolution in vitro samples were obtained using the Gamble solution as a simulated solution for body fluids and PIXE (Particle Induced X rays Emissions) technique was used to characterize them. In order to characterize the worker exposure to Ta bearing particles a Brazilian niobium mine was selected. The mineral dust particles were collected using a six-stage cascade impactor and the elemental mass concentrations and the MMAD (Mass Median Aerodynamic Diameter) were determined. The results show that the workers are exposed to Ta bearing particles in the respirable fraction of aerosols (< 2.5 {mu}m) during the mineral processing to obtain Fe-Nb alloy. The solubility in Simulant Lung Fluid (SLF) of Ta present in mineral dust particles depend on the mineral characteristics. The solubility half-time varies between 34 to 62 hours depending on the associated mineral. (author)

  12. Novel electrosprayed nanospherules for enhanced aqueous solubility and oral bioavailability of poorly water-soluble fenofibrate.

    Science.gov (United States)

    Yousaf, Abid Mehmood; Mustapha, Omer; Kim, Dong Wuk; Kim, Dong Shik; Kim, Kyeong Soo; Jin, Sung Giu; Yong, Chul Soon; Youn, Yu Seok; Oh, Yu-Kyoung; Kim, Jong Oh; Choi, Han-Gon

    2016-01-01

    The purpose of the present research was to develop a novel electrosprayed nanospherule providing the most optimized aqueous solubility and oral bioavailability for poorly water-soluble fenofibrate. Numerous fenofibrate-loaded electrosprayed nanospherules were prepared with polyvinylpyrrolidone (PVP) and Labrafil(®) M 2125 as carriers using the electrospray technique, and the effect of the carriers on drug solubility and solvation was assessed. The solid state characterization of an optimized formulation was conducted by scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared spectroscopic analyses. Oral bioavailability in rats was also evaluated for the formulation of an optimized nanospherule in comparison with free drug and a conventional fenofibrate-loaded solid dispersion. All of the electrosprayed nanospherule formulations had remarkably enhanced aqueous solubility and dissolution compared with free drug. Moreover, Labrafil M 2125, a surfactant, had a positive influence on the solubility and dissolution of the drug in the electrosprayed nanospherule. Increases were observed as the PVP/drug ratio increased to 4:1, but higher ratios gave no significant increases. In particular, an electrosprayed nanospherule composed of fenofibrate, PVP, and Labrafil M 2125 at the weight ratio of 1:4:0.5 resulted in a particle size of state. It demonstrated the highest solubility (32.51±2.41 μg/mL), an excellent dissolution (~85% in 10 minutes), and an oral bioavailability ~2.5-fold better than that of the free drug. It showed similar oral bioavailability compared to the conventional solid dispersion. Electrosprayed nanospherules, which provide improved solubility and bioavailability, are promising drug delivery tools for oral administration of poorly water-soluble fenofibrate.

  13. Coccidioides immitis Vaccine: Potential of an Alkali-Soluble, Water-Soluble Cell Wall Antigen

    Science.gov (United States)

    Lecara, Grace; Cox, Rebecca A.; Simpson, Russell B.

    1983-01-01

    C-ASWS-M, the alkali-soluble, water-soluble cell wall antigen of Coccidioides immitis mycelia, was evaluated for its vaccine potential in mice. Vaccination with 0.5-, 1.5-, or 3-mg doses of C-ASWS-M in complete Freund adjuvant provided a significant level of protection against intraperitoneal challenge with 1,500 arthroconidia (P 0.05). PMID:6822433

  14. Determination of radionuclide solubility limits to be used in SR 97. Uncertainties associated to calculated solubilities

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, J.; Cera, E.; Duro, L.; Jordana, S. [QuantiSci S.L., Barcelona (Spain); Pablo, J. de [DEQ-UPC, Barcelona (Spain); Savage, D. [QuantiSci Ltd., Henley-on-Thames (United Kingdom)

    1997-12-01

    The thermochemical behaviour of 24 critical radionuclides for the forthcoming SR97 PA exercise is discussed. The available databases are reviewed and updated with new data and an extended database for aqueous and solid species of the radionuclides of interest is proposed. We have calculated solubility limits for the radionuclides of interest under different groundwater compositions. A sensitivity analysis of the calculated solubilities with the composition of the groundwater is presented. Besides selecting the most likely solubility limiting phases, in this work we have used coprecipitation approaches in order to calculate more realistic solubility limits for minor radionuclides, such as Ra, Am and Cm. The comparison between the calculated solubilities and the concentrations measured in relevant natural systems (NA) and in spent fuel leaching experiments helps to assess the validity of the methodology used and to derive source term concentrations for the radionuclides studied. The uncertainties associated to the solubilities of the main radionuclides involved in the spent nuclear fuel have also been discussed in this work. The variability of the groundwater chemistry; redox conditions and temperature of the system have been considered the main factors affecting the solubilities. In this case, a sensitivity analysis has been performed in order to study solubility changes as a function of these parameters. The uncertainties have been calculated by including the values found in a major extent in typical granitic groundwaters. The results obtained from this analysis indicate that there are some radionuclides which are not affected by these parameters, i.e. Ag, Cm, Ho, Nb, Ni, Np, Pu, Se, Sm, Sn, Sr, Tc and U

  15. Use of Hoy's solubility parameters to predict water sorption/solubility of experimental primers and adhesives.

    Science.gov (United States)

    Nishitani, Yoshihiro; Yoshiyama, Masahiro; Hosaka, Keiichi; Tagami, Junji; Donnelly, Adam; Carrilho, Marcela; Tay, Franklin R; Pashley, David H

    2007-02-01

    Self-etching primers and adhesives contain very hydrophilic acidic monomers that result in high water sorption/solubilities of their polymers. However, the chemical composition of these products varies widely. The purpose of this work was to vary the chemical composition of experimental self-etching primers and adhesives to determine if the water sorption/solubility of the polymers were affected in a predictable manner. The Hoy's solubility parameters of these mixtures were calculated to permit ranking of the degree of hydrophilicity of the polymers. Water sorption/solubility was measured according to ISO 4049. The results showed highly significant (R(2) = 0.86, P solubility parameter for polar forces (delta(p)) of the polymers. Similar correlations were obtained between polymer solubility and delta(p). When these results were compared with previously published results obtained with more hydrophobic resins, excellent correlations were obtained, indicating that Hoy's delta(p) values may be used to predict the water sorption behavior of methylmethacrylate polymers.

  16. Combined wet oxidation and alkaline hydrolysis of polyvinylchloride

    DEFF Research Database (Denmark)

    Sørensen, E.; Bjerre, A.B.

    1992-01-01

    In view of the widespread aversion to burning polyvinylchloride (PVC) together with municipal waste, we have attempted an alternative approach to its decomposition. This paper describes a combined wet oxidation/alkaline hydrolysis yielding water soluble, biodegradable products. Experiments were...

  17. Water Solubility of Plutonium and Uranium Compounds and Residues at TA-55

    Energy Technology Data Exchange (ETDEWEB)

    Reilly, Sean Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Smith, Paul Herrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Jarvinen, Gordon D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Prochnow, David Adrian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Schulte, Louis D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; DeBurgomaster, Paul Christopher [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Fife, Keith William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Rubin, Jim [Los Alamos National Lab. (LANL), Los Alamos, NM (United States; Worl, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States

    2016-06-13

    Understanding the water solubility of plutonium and uranium compounds and residues at TA-55 is necessary to provide a technical basis for appropriate criticality safety, safety basis and accountability controls. Individual compound solubility was determined using published solubility data and solution thermodynamic modeling. Residue solubility was estimated using a combination of published technical reports and process knowledge of constituent compounds. The scope of materials considered includes all compounds and residues at TA-55 as of March 2016 that contain Pu-239 or U-235 where any single item in the facility has more than 500 g of nuclear material. This analysis indicates that the following materials are not appreciably soluble in water: plutonium dioxide (IDC=C21), plutonium phosphate (IDC=C66), plutonium tetrafluoride (IDC=C80), plutonium filter residue (IDC=R26), plutonium hydroxide precipitate (IDC=R41), plutonium DOR salt (IDC=R42), plutonium incinerator ash (IDC=R47), uranium carbide (IDC=C13), uranium dioxide (IDC=C21), U3O8 (IDC=C88), and uranium filter residue (IDC=R26). This analysis also indicates that the following materials are soluble in water: plutonium chloride (IDC=C19) and uranium nitrate (IDC=C52). Equilibrium calculations suggest that PuOCl is water soluble under certain conditions, but some plutonium processing reports indicate that it is insoluble when present in electrorefining residues (R65). Plutonium molten salt extraction residues (IDC=R83) contain significant quantities of PuCl3, and are expected to be soluble in water. The solubility of the following plutonium residues is indeterminate due to conflicting reports, insufficient process knowledge or process-dependent composition: calcium salt (IDC=R09), electrorefining salt (IDC=R65), salt (IDC=R71), silica (IDC=R73) and sweepings/screenings (IDC=R78). Solution thermodynamic modeling also indicates that fire suppression water buffered with a

  18. Antibacterial effect of water-soluble chitosan on representative dental pathogens Streptococcus mutans and Lactobacilli brevis

    Directory of Open Access Journals (Sweden)

    Chih-Yu Chen

    2012-12-01

    , the alcohol-free mouthwash exhibited no cytotoxicity and no oral stinging. To the best of our knowledge, this was the first study to combine in vitro and in vivo investigations to analyze the antibacterial properties of water-soluble chitosan-containing mouthwash. CONCLUSIONS: This study illustrated that water-soluble chitosan may be a viable alternative to commercial mouthwashes in the future.

  19. Evaluation of drug-polymer solubility curves through formal statistical analysis

    DEFF Research Database (Denmark)

    Knopp, Matthias Manne; Olesen, Niels Erik; Holm, Per

    2015-01-01

    In this study, the influence of the preparation technique (ball milling, spray drying, and film casting) of a supersaturated amorphous dispersion on the quality of solubility determinations of indomethacin in polyvinylpyrrolidone was investigated by means of statistical analysis. After annealing...... mixtures was not consistent with those from spray drying and film casting, indicating fundamental differences between the preparation techniques. Through formal statistical analysis, the best combination of fit to the Flory-Huggins model and reproducibility of the measurements was analyzed. Ball milling...... of the amorphous dispersions above the crystallization temperature for 2 h, the solubility curve was derived from the glass transition temperature of the demixed material using the Gordon-Taylor relationship and fitting with the Flory-Huggins model. The study showed that the predicted solubility from the ball-milled...

  20. Dermal nanocrystals from medium soluble actives - physical stability and stability affecting parameters.

    Science.gov (United States)

    Zhai, Xuezhen; Lademann, Jürgen; Keck, Cornelia M; Müller, Rainer H

    2014-09-01

    Nanocrystals are meanwhile applied to increase the dermal penetration of drugs, but were applied by now only to poorly soluble drugs (e.g. 1-10 μg/ml). As a new concept nanocrystals from medium soluble actives were produced, using caffeine as model compound (solubility 16 mg/ml at 20 °C). Penetration should be increased by (a) further increase in solubility and (b) mainly by increased hair follicle targeting of nanocrystals compared to pure solution. Caffeine nanocrystal production in water lead to pronounced crystal growth. Therefore the stability of nanocrystals in water-ethanol (1:9) and ethanol-propylene glycol (3:7) mixtures with lower dielectric constant D was investigated, using various stabilizers. Both mixtures in combination with Carbopol 981 (non-neutralized) yielded stable nanosuspensions over 2 months at 4 °C and room temperature. Storage at 40 °C lead to crystal growth, attributed to too strong solubility increase, supersaturation and Ostwald ripening effects. Stability of caffeine nanocrystals at lower temperatures could not only be attributed to lower solubility, because the solubilities of caffeine in mixtures and in water are not that much different. Other effects such as quantified by reduced dielectric constant D, and specific interactions between dispersion medium and crystal surface seem to play a role. With the 2 mixtures and Carbopol 981, a basic formulation composition for this type of nanocrystals has been established, to be used in the in vivo proof of principle of the new concept. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Alternative splicing of the human gene SYBL1 modulates protein domain architecture of longin VAMP7/TI-VAMP, showing both non-SNARE and synaptobrevin-like isoforms

    Directory of Open Access Journals (Sweden)

    De Franceschi Nicola

    2011-05-01

    Full Text Available Abstract Background The control of intracellular vesicle trafficking is an ideal target to weigh the role of alternative splicing in shaping genomes to make cells. Alternative splicing has been reported for several Soluble N-ethylmaleimide-sensitive factor Attachment protein REceptors of the vesicle (v-SNAREs or of the target membrane (t-SNARES, which are crucial to intracellular membrane fusion and protein and lipid traffic in Eukaryotes. However, splicing has not yet been investigated in Longins, i.e. the most widespread v-SNAREs. Longins are essential in Eukaryotes and prototyped by VAMP7, Sec22b and Ykt6, sharing a conserved N-terminal Longin domain which regulates membrane fusion and subcellular targeting. Human VAMP7/TI-VAMP, encoded by gene SYBL1, is involved in multiple cell pathways, including control of neurite outgrowth. Results Alternative splicing of SYBL1 by exon skipping events results in the production of a number of VAMP7 isoforms. In-frame or frameshift coding sequence modifications modulate domain architecture of VAMP7 isoforms, which can lack whole domains or domain fragments and show variant or extra domains. Intriguingly, two main types of VAMP7 isoforms either share the inhibitory Longin domain and lack the fusion-promoting SNARE motif, or vice versa. Expression analysis in different tissues and cell lines, quantitative real time RT-PCR and confocal microscopy analysis of fluorescent protein-tagged isoforms demonstrate that VAMP7 variants have different tissue specificities and subcellular localizations. Moreover, design and use of isoform-specific antibodies provided preliminary evidence for the existence of splice variants at the protein level. Conclusions Previous evidence on VAMP7 suggests inhibitory functions for the Longin domain and fusion/growth promoting activity for the Δ-longin molecule. Thus, non-SNARE isoforms with Longin domain and non-longin SNARE isoforms might have somehow opposite regulatory functions

  2. Preparation of Hydrochlorothiazide Nanoparticles for Solubility Enhancement

    Directory of Open Access Journals (Sweden)

    Eliska Vaculikova

    2016-08-01

    Full Text Available Nanoparticles can be considered as a useful tool for improving properties of poorly soluble active ingredients. Hydrochlorothiazide (Class IV of the Biopharmaceutical Classification System was chosen as a model compound. Antisolvent precipitation-solvent evaporation and emulsion solvent evaporation methods were used for preparation of 18 samples containing hydrochlorothiazide nanoparticles. Water solutions of surfactants sodium dodecyl sulfate, Tween 80 and carboxymethyl dextran were used in mass concentrations of 1%, 3% and 5%. Acetone and dichloromethane were used as solvents of the model compound. The particle size of the prepared samples was measured by dynamic light scattering. The selected sample of hydrochlorothiazide nanoparticles stabilized with carboxymethyl dextran sodium salt with particle size 2.6 nm was characterized additionally by Fourier transform mid-infrared spectroscopy and scanning electron microscopy. It was found that the solubility of this sample was 6.5-fold higher than that of bulk hydrochlorothiazide.

  3. Absorption of Soluble Gases by Atmospheric Nanoaerosols

    CERN Document Server

    Elperin, Tov; Krasovitov, Boris; Lushnikov, Alexey

    2012-01-01

    We investigate mass transfer during absorption of atmospheric trace soluble gases by a single droplet whose size is comparable to the molecular mean free path in air at normal conditions. It is assumed that the trace reactant diffuses to the droplet surface and then reacts with the substances inside the droplet according to the first order rate law. Our analysis applies a flux-matching theory of transport processes in gases and assumes constant thermophysical properties of the gases and liquids. We derive an integral equation of Volterra type for the transient molecular flux density to a liquid droplet and solve it numerically. Numerical calculations are performed for absorption of sulfur dioxide (SO2), dinitrogen trioxide (N2O3) and chlorine (Cl2) by liquid nanoaerosols accompanied by chemical dissociation reaction. It is shown that during gas absorption by nanoaerosols the kinetic effects play significant role, and neglecting kinetic effects leads to significant overestimation of the soluble gas flux into a...

  4. Soluble L-selectin levels predict survival in sepsis

    DEFF Research Database (Denmark)

    Seidelin, Jakob B; Nielsen, Ole H; Strøm, Jens

    2002-01-01

    To evaluate serum soluble L-selectin as a prognostic factor for survival in patients with sepsis.......To evaluate serum soluble L-selectin as a prognostic factor for survival in patients with sepsis....

  5. Solubility, emulsion and foraming properties of coconut ( Cocos ...

    African Journals Online (AJOL)

    % proteins (on a dry weight basis), respectively, were prepared from freeze-dried coconut meal samples. Selected functional properties such as: nitrogen solubility, emulsion and foaming properties were determined. Nitrogen solubility was ...

  6. Influence of Polymer Molecular Weight on Drug-Polymer Solubility

    DEFF Research Database (Denmark)

    Knopp, Matthias Manne; Olesen, Niels Erik; Holm, Per

    2015-01-01

    In this study, the influence of polymer molecular weight on drug-polymer solubility was investigated using binary systems containing indomethacin (IMC) and polyvinylpyrrolidone (PVP) of different molecular weights. The experimental solubility in PVP, measured using a differential scanning...... calorimetry annealing method, was compared with the solubility calculated from the solubility of the drug in the liquid analogue N-vinylpyrrolidone (NVP). The experimental solubility of IMC in the low-molecular-weight PVP K12 was not significantly different from that in the higher molecular weight PVPs (K25......, K30, and K90). The calculated solubilities derived from the solubility in NVP (0.31-0.32 g/g) were found to be lower than those experimentally determined in PVP (0.38-0.40 g/g). Nevertheless, the similarity between the values indicates that the analogue solubility can provide valuable indications...

  7. Water soluble azido polyisocyanides as functional beta-sheet mimics

    NARCIS (Netherlands)

    Schwartz, Erik; Schwartz, E.; Koepf, Matthieu; Kitto, Heather J.; Espelt, Mónica; Nebot-Carda, Vicent J.; de Gelder, Rene; Nolte, Roeland J.M.; Cornelissen, Jeroen Johannes Lambertus Maria; Rowan, Alan E.

    2009-01-01

    The design and synthesis of functional biomimetic water soluble polymers with a defined secondary structure has been developed using β-sheet polyisocyanopeptide scaffolds. Water soluble isocyanopolymers were prepared by random copolymerisation of the azido functionalized isocyanopeptides with

  8. The effect of the cation alkyl chain branching on mutual solubilities with water and toxicities.

    Science.gov (United States)

    Kurnia, Kiki A; Sintra, Tânia E; Neves, Catarina M S S; Shimizu, Karina; Canongia Lopes, José N; Gonçalves, Fernando; Ventura, Sónia P M; Freire, Mara G; Santos, Luís M N B F; Coutinho, João A P

    2014-10-07

    The design of ionic liquids has been focused on the cation-anion combinations but other more subtle approaches can be used. In this work the effect of the branching of the cation alkyl chain on the design of ionic liquids (ILs) is evaluated. The mutual solubilities with water and toxicities of a series of bis(trifluoromethylsulfonyl)-based ILs, combined with imidazolium, pyridinium, pyrrolidinium, and piperidinium cations with linear or branched alkyl chains, are reported. The mutual solubility measurements were carried out in the temperature range from (288.15 to 323.15) K. From the obtained experimental data, the thermodynamic properties of the solution (in the water-rich phase) were determined and discussed. The COnductor like Screening MOdel for Real Solvents (COSMO-RS) was used to predict the liquid-liquid equilibrium. Furthermore, molecular dynamic simulations were also carried out aiming to get a deeper understanding of these fluids at the molecular level. The results show that the increase in the number of atoms at the cation ring (from five to six) leads to a decrease in the mutual solubilities with water while increasing their toxicity, and as expected from the well-established relationship between toxicities and hydrophobicities of ILs. The branching of the alkyl chain was observed to decrease the water solubility in ILs, while increasing the ILs solubility in water. The inability of COSMO-RS to correctly predict the effect of branching alkyl chains toward water solubility on them was confirmed using molecular dynamic simulations to be due to the formation of nano-segregated structures of the ILs that are not taken into account by the COSMO-RS model. In addition, the impact of branched alkyl chains on the toxicity is shown to be not trivial and to depend on the aromatic nature of the ILs.

  9. Soluble interleukin 2 receptor in atopic eczema.

    OpenAIRE

    Colver, G. B.; Symons, J A; Duff, G. W.

    1989-01-01

    OBJECTIVE--To determine whether serum soluble interleukin 2 receptor concentrations are related to disease activity in atopic eczema. DESIGN--Single cohort longitudinal study with controls. SETTING--Outpatient and general medicine departments in secondary referral centre. PATIENTS--Of 15 patients aged 17-57 with severe atopic eczema, all with acute exacerbations of disease, 13 were admitted to hospital and two treated as outpatients until the skin lesions had resolved or greatly improved. Nin...

  10. Chlorine solubility in evolved alkaline magmas

    Directory of Open Access Journals (Sweden)

    M. R. Carroll

    2005-06-01

    Full Text Available Experimental studies of Cl solubility in trachytic to phonolitic melts provide insights into the capacity of alkaline magmas to transport Cl from depth to the earth?s surface and atmosphere, and information on Cl solubility variations with pressure, temperature and melt or fluid composition is crucial for understanding the reasons for variations in Cl emissions at active volcanoes. This paper provides a brief review of Cl solubility experiments conducted on a range of trachytic to phonolitic melt compositions. Depending on the experimental conditions the melts studied were in equilibrium with either a Cl-bearing aqueous fluid or a subcritical assemblage of low- Cl aqueous fluid + Cl-rich brine. The nature of the fluid phase(s was identified by examination of fluid inclusions present in run product glasses and the fluid bulk composition was calculated by mass balance. Chlorine concentrations in the glass increase with increasing Cl molality in the fluid phase until a plateau in Cl concentration is reached when melt coexists with aqueous fluid + brine. With fluids of similar Cl molality, higher Cl concentrations are observed in peralkaline phonolitic melts compared with peraluminous phonolitic melts; overall the Cl concentrations observed in phonolitic and trachytic melts are approximately twice those found in calcalkaline rhyolitic melts under similar conditions. The observed negative pressure dependence of Cl solubility implies that Cl contents of melts may actually increase during magma decompression if the magma coexists with aqueous fluid and Cl-rich brine (assuming melt-vapor equilibrium is maintained. The high Cl contents (approaching 1 wt% Cl observed in some melts/glasses from the Vesuvius and Campi Flegrei areas suggest saturation with a Cl-rich brine prior to eruption.

  11. Enhanced neuroinvasion by smaller, soluble prions.

    Science.gov (United States)

    Bett, Cyrus; Lawrence, Jessica; Kurt, Timothy D; Orru, Christina; Aguilar-Calvo, Patricia; Kincaid, Anthony E; Surewicz, Witold K; Caughey, Byron; Wu, Chengbiao; Sigurdson, Christina J

    2017-04-21

    Infectious prion aggregates can propagate from extraneural sites into the brain with remarkable efficiency, likely transported via peripheral nerves. Yet not all prions spread into the brain, and the physical properties of a prion that is capable of transit within neurons remain unclear. We hypothesized that small, diffusible aggregates spread into the CNS via peripheral nerves. Here we used a structurally diverse panel of prion strains to analyze how the prion conformation impacts transit into the brain. Two prion strains form fibrils visible ultrastructurally in the brain in situ, whereas three strains form diffuse, subfibrillar prion deposits and no visible fibrils. The subfibrillar strains had significantly higher levels of soluble prion aggregates than the fibrillar strains. Primary neurons internalized both the subfibrillar and fibril-forming prion strains by macropinocytosis, and both strain types were transported from the axon terminal to the cell body in vitro. However in mice, only the predominantly soluble, subfibrillar prions, and not the fibrillar prions, were efficiently transported from the tongue to the brain. Sonicating a fibrillar prion strain increased the solubility and enabled prions to spread into the brain in mice, as evident by a 40% increase in the attack rate, indicating that an increase in smaller particles enhances prion neuroinvasion. Our data suggest that the small, highly soluble prion particles have a higher capacity for transport via nerves. These findings help explain how prions that predominantly assemble into subfibrillar states can more effectively traverse into and out of the CNS, and suggest that promoting fibril assembly may slow the neuron-to-neuron spread of protein aggregates.

  12. Solubility of zinc ferrite in high-temperature oxygenated water

    Science.gov (United States)

    Hanzawa, Yukiko; Hiroishi, Daisuke; Matsuura, Chihiro; Ishigure, Kenkichi

    1998-02-01

    The solubility of zinc ferrite was measured at 423 K, 473 K, and 523 K in an oxygenated water system, which is rather similar to the chemical condition of boiling water reactors. Thermodynamic analysis was performed by a procedure minimizing standard Gibbs free energy of the system at the final state. From both the analysis and the experimental results it was concluded that the dissolution process of ZnFe 2O 4 in conditions where no redox reaction occurs is described by combination of ZnFe 2O 4 dissolution and Fe 2O 3 precipitation equilibria. By fitting to the experimental results, thermodynamic data of ZnFe 2O 4 are re-analyzed at 423 K, 473 K, and 523 K.

  13. Quality guidelines for oral drug candidates: dose, solubility and lipophilicity.

    Science.gov (United States)

    Bayliss, Martin K; Butler, James; Feldman, Paul L; Green, Darren V S; Leeson, Paul D; Palovich, Michael R; Taylor, Anthony J

    2016-10-01

    In an attempt to seek increased understanding of compound attributes that influence successful drug pipeline progression, GlaxoSmithKline's portfolio of oral candidates was compared with reference sets of marketed oral drugs. The approach differs from other attrition studies by explicitly focusing on choosing 'the right compound' by applying relevant, experimentally derived properties. The analysis led to four proposed compound quality categories, created by combining specific criteria for three measures: dose, solubility and the property forecast index, a composite measure of lipophilicity using chromatographically determined LogD and aromaticity. The 'three properties' provide benchmarked guidelines for project teams to use when seeking and selecting clinical candidates, because they reflect the property distribution of marketed oral drugs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Self-assembly of soluble unlinked and cross-linked fibrin oligomers.

    Science.gov (United States)

    Rosenfeld, M A; Leonova, V B; Biryukova, M I; Vasileva, M V

    2011-10-01

    Self-assembly of soluble unlinked and cross-linked fibrin oligomers formed from desA-fibrin monomer under the influence of factor XIIIa was studied in the presence of non-denaturing urea concentrations. By methods of elastic and dynamic light scattering combined with analytical ultracentrifugation, desA-fibrin oligomers formed in both the presence and absence of the factor XIIIa were shown to be ensembles consisting of soluble rod-like double-stranded protofibrils with diverse weight and size. Unlinked and cross-linked soluble double-stranded protofibrils can reach the length of 350-450 nm. The structure of soluble covalently-linked protofibrils is stabilized by isopeptide γ-dimers. Electrophoretic data indicate a complete absence of isopeptide bonds between α-chains of desA-fibrin molecules. The molecular mechanism of formation of soluble rod-like fibrin structures and specific features of its covalent stabilization under the influence of factor XIIIa are discussed.

  15. Molecular dynamics simulations of zinc oxide solubility: From bulk down to nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Escorihuela, Laura; Fernández, Alberto; Rallo, Robert; Martorell, Benjamí

    2018-02-01

    The solubility of metal oxides is one of the key descriptors for the evaluation of their potential toxic effects, both in the bulk form and in nanoparticulated aggregates. Current work presents a new methodology for the in silico assessment of the solubility of metal oxides, which is demonstrated using a well-studied system, ZnO. The calculation of the solubility is based on statistical thermodynamics tools combined with Density Functional Tight Binding theory for the evaluation of the free energy exchange during the dissolution process. Models of small ZnO clusters are used for describing the final dissolved material, since the complete ionic dissolution of ZnO is hindered by the formation of O2- anions in solution, which are highly unstable. Results show very good agreement between the computed solubility values and experimental data for ZnO bulk, up to 0.5 mg·L-1 and equivalents of 50 g·L-1 for the free Zn2+ cation in solution. However, the reference model for solid nanoparticles formed by free space nanoparticles can only give a limited quantitative solubility evaluation for ZnO nanoparticles.

  16. Molecular dynamics simulations of zinc oxide solubility: From bulk down to nanoparticles.

    Science.gov (United States)

    Escorihuela, Laura; Fernández, Alberto; Rallo, Robert; Martorell, Benjamí

    2017-07-20

    The solubility of metal oxides is one of the key descriptors for the evaluation of their potential toxic effects, both in the bulk form and in nanoparticulated aggregates. Current work presents a new methodology for the in silico assessment of the solubility of metal oxides, which is demonstrated using a well-studied system, ZnO. The calculation of the solubility is based on statistical thermodynamics tools combined with Density Functional Tight Binding theory for the evaluation of the free energy exchange during the dissolution process. Models of small ZnO clusters are used for describing the final dissolved material, since the complete ionic dissolution of ZnO is hindered by the formation of O2- anions in solution, which are highly unstable. Results show very good agreement between the computed solubility values and experimental data for ZnO bulk, up to 0.5 mg L-1 and equivalents of 50 μg L-1 for the free Zn2+ cation in solution. However, the reference model for solid nanoparticles formed by free space nanoparticles can only give a limited quantitative solubility evaluation for ZnO nanoparticles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Supercritical fluid particle design for poorly water-soluble drugs (review).

    Science.gov (United States)

    Sun, Yongda

    2014-01-01

    Supercritical fluid particle design (SCF PD) offers a number of routes to improve solubility and dissolution rate for enhancing the bioavailability of poorly water-soluble drugs, which can be adopted through an in-depth knowledge of SCF PD processes and the molecular properties of active pharmaceutical ingredients (API) and drug delivery system (DDS). Combining with research experiences in our laboratory, this review focuses on the most recent development of different routes (nano-micron particles, polymorphic particles, composite particles and bio-drug particles) to improve solubility and dissolution rate of poorly water-soluble drugs, covering the fundamental concept of SCF and the principle of SCF PD processes which are typically used to control particle size, shape, morphology and particle form and hence enable notable improvement in the dissolution rate of the poorly water-soluble drugs. The progress of the industrialization of SCF PD processes in pharmaceutical manufacturing environment with scaled-up plant under current good manufacturing process (GMP) specification is also considered in this review.

  18. A new method to determine the partial solubility parameters of polymers from intrinsic viscosity.

    Science.gov (United States)

    Bustamante, Pilar; Navarro-Lupión, Javier; Escalera, Begoña

    2005-02-01

    A modification of the extended Hansen method, formerly used to determine the partial solubility parameters of drugs and non-polymeric excipients is tested with a polymer for the first time. The proposed method relates the logarithm of the intrinsic viscosities of the polymer in a series of solvents and solvent mixtures with the Hansen (three parameter model) and Karger (four parameter model) partial solubility parameters. The viscosity of diluted solutions of hydroxypropyl methylcellulose (HPMC) was determined in pure solvents and binary mixtures of varying polarity. The intrinsic viscosity was obtained from the common intercept of the Huggins and Kraemer relationships. The intrinsic viscosity tends to increase with increasing the solubility parameter of the medium. The results show that hydrogen bonding and polarity of the polymer largely determine polymer-solvent interactions. The models proposed provided reasonable partial and total solubility parameters for the polymer and enable one to quantitatively characterize, for the first time, the Lewis acid-base ability of a polymer thus, providing a more realistic picture of hydrogen bonding for solvent selection/compatibility and to predict drug-polymer interactions. Combination of the dispersion and polar parameters into a single non-specific solubility parameter was also tested. The results extend earlier findings and suggest that the models are quite versatile and may be applied to drugs, non-polymeric and polymeric excipients.

  19. Production and characterization of cowpea protein hydrolysate with optimum nitrogen solubility by enzymatic hydrolysis using pepsin.

    Science.gov (United States)

    Mune Mune, Martin Alain; Minka, Samuel René

    2017-06-01

    Cowpea is a source of low-cost and good nutritional quality protein for utilization in food formulations in replacement of animal proteins. Therefore it is necessary that cowpea protein exhibits good functionality, particularly protein solubility which affects the other functional properties. The objective of this study was to produce cowpea protein hydrolysate exhibiting optimum solubility by the adequate combination of hydrolysis parameters, namely time, solid/liquid ratio (SLR) and enzyme/substrate ratio (ESR), and to determine its functional properties and molecular characteristics. A Box-Behnken experimental design was used for the experiments, and a second-order polynomial to model the effects of hydrolysis time, SLR and ESR on the degree of hydrolysis and nitrogen solubility index. The optimum hydrolysis conditions of time 208.61 min, SLR 1/15 (w/w) and ESR 2.25% (w/w) yielded a nitrogen solubility of 75.71%. Protein breakdown and the peptide profile following enzymatic hydrolysis were evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and size exclusion chromatography. Cowpea protein hydrolysate showed higher oil absorption capacity, emulsifying activity and foaming ability compared with the concentrate. The solubility of cowpea protein hydrolysate was adequately optimized by response surface methodology, and the hydrolysate showed adequate functionality for use in food. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  20. Soluble Aβ aggregates can inhibit prion propagation.

    Science.gov (United States)

    Sarell, Claire J; Quarterman, Emma; Yip, Daniel C-M; Terry, Cassandra; Nicoll, Andrew J; Wadsworth, Jonathan D F; Farrow, Mark A; Walsh, Dominic M; Collinge, John

    2017-11-01

    Mammalian prions cause lethal neurodegenerative diseases such as Creutzfeldt-Jakob disease (CJD) and consist of multi-chain assemblies of misfolded cellular prion protein (PrPC). Ligands that bind to PrPC can inhibit prion propagation and neurotoxicity. Extensive prior work established that certain soluble assemblies of the Alzheimer's disease (AD)-associated amyloid β-protein (Aβ) can tightly bind to PrPC, and that this interaction may be relevant to their toxicity in AD. Here, we investigated whether such soluble Aβ assemblies might, conversely, have an inhibitory effect on prion propagation. Using cellular models of prion infection and propagation and distinct Aβ preparations, we found that the form of Aβ assemblies which most avidly bound to PrP in vitro also inhibited prion infection and propagation. By contrast, forms of Aβ which exhibit little or no binding to PrP were unable to attenuate prion propagation. These data suggest that soluble aggregates of Aβ can compete with prions for binding to PrPC and emphasize the bidirectional nature of the interplay between Aβ and PrPC in Alzheimer's and prion diseases. Such inhibitory effects of Aβ on prion propagation may contribute to the apparent fall-off in the incidence of sporadic CJD at advanced age where cerebral Aβ deposition is common. © 2017 The Authors.

  1. Modeling dissolution of sparingly soluble multisized powders.

    Science.gov (United States)

    de Almeida, L P; Simöes, S; Brito, P; Portugal, A; Figueiredo, M

    1997-06-01

    The dissolution of powder drugs, besides being a topic of utmost importance, especially for the sparingly soluble ones, is far from being well-explained. The purpose of the present study is, on the one hand, to obtain experimental dissolution profiles and, on the other hand, to analyze and process the data for dissolution modeling. Three different size fractions of a widely used sparingly soluble drug--ibuprofen--were fully characterized with regard to its particle size distribution, specific surface area, density, solubility, and diffusion coefficient. The dissolution profiles were obtained making use of a technique that counts and sizes particles--the Coulter counter technique--which is capable of following the number and size of the particles in suspension throughout time. The knowledge of these parameters allowed a critical study of the assumptions associated with the models currently used to describe the dissolution process. It was concluded that most of the assumptions were not valid for the present experimental conditions. This motivated the proposal of a new methodology, which uses the experimentally determined characteristics of the drug and takes into account the polydisperse nature of the powder. By applying an adequate dissolution equation to each of the many size classes in which the primary particle size distribution was divided, it was possible to obtain a large agreement between the simulated and the experimental dissolution profile.

  2. Limited drug solubility can be decisive even for freely soluble drugs in highly swollen matrix tablets.

    Science.gov (United States)

    Siepmann, F; Karrout, Y; Gehrke, M; Penz, F K; Siepmann, J

    2017-06-30

    The aim of this study was to elucidate the importance of potential limited solubility effects for the control of drug release from hydrophilic matrix tablets loaded with a freely water-soluble drug. It is often assumed that the considerable amounts of water penetrating into this type of advanced drug delivery systems are sufficient to rapidly dissolve the entire drug loading, and that limited drug solubility is not playing a role for the control of drug release. Here, we show that this assumption can be erroneous. HPMC/lactose matrix tablets were loaded with 5 to 60% diprophylline (e.g. solubility in 0.1M HCl at 37°C: 235mg/mL), and drug release was measured at low and neutral pH, respectively. A mechanistically realistic mathematical theory was applied, considering drug diffusion in axial and radial direction in the cylindrical matrices and the potential co-existence of dissolved and non-dissolved drug. Importantly, only dissolved drug is available for diffusion. It is demonstrated that during major parts of the release periods, non-dissolved drug excess exists within tablets containing 30% or more diprophylline, despite of the substantial water contents of the systems. This leads to partially almost linear drug concentration distance profiles within the tablets, and reveals a major contribution of limited drug solubility effects to the control of drug release, even in the case of freely water-soluble diprophylline. It can be expected that also in other types of drug delivery systems, e.g. microparticles and implants (containing much less water), limited drug solubility effects play a much more important role than currently recognized. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Solubility of carbamazepine co-crystals in ethanolic solution

    Science.gov (United States)

    Ramle, Noor Ashila; Rahim, Syarifah Abd; Anuar, Nornizar; El-Hadad, Omar

    2017-08-01

    The study aimed to determine the solubility of carbamazepine (CBZ) co-crystals formed from co-crystal formers (CCFs) of nicotinamide (NIC), saccharin (SAC), succinic acid (SUC) and fumaric acid (FUM) at various temperatures (25-50°C). High Performance Liquid Chromatography (HPLC) was used to determine the solubility and the X-Ray Powder Diffraction was used to characterize the crystals. The solubility of CBZ-NIC and CBZ-FUM co-crystals were found to be higher than the solubility of the CBZ for the range of studied temperatures. However, opposite findings was obtained for CBZ-SUC co-crystal as its solubility is lower than the solubility of CBZ. Different trend was found for CBZ-SAC co-crystal in which for temperature lower than 40°C, the solubility of CBZ crystal is higher than the CBZ-SAC co-crystal. The solubility of CBZ-SAC co-crystal is higher than the solubility of CBZ at a temperature above 40°C. CBZ co-crystals with NIC and FUM have shown to increase the solubility of CBZ by solubility ratio of 1.95 and 1.24 respectively. However, the CBZ co-crystal with SAC was found to have similar solubility value as the CBZ.

  4. Study on soluble expression of glutamate dehydrogenase from tea ...

    African Journals Online (AJOL)

    The results reveal that without any solublizing partners, the fusion CsGDH2 was predominantly found in insoluble bodies and no soluble protein was detected by either sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) or western blot, whereas GB1, MBP and NusA tags may enhance the soluble ...

  5. Solubility of Meloxicam in Mixed Solvent Systems | Babu | Ethiopian ...

    African Journals Online (AJOL)

    The extent of solubility of meloxicam is the same in ethanol and PG, but is higher when compared to its solubility in water, indicating the role of hydrogen ... Meloxicam solubility studies in PEG 400 and other vehicles provide an idea to understand the nature of interactions between the drug and the solvent system employed.

  6. Fluorinated Silsesquioxanes: Structure, Solubility, and Wetting (Briefing charts)

    Science.gov (United States)

    2015-08-01

    Charts 3. DATES COVERED (From - To) July 2015-July 2015 4. TITLE AND SUBTITLE FLUORINATED SILSESQUIOXANES: STRUCTURE, SOLUBILITY , AND WETTING...FLUORINATED SILSESQUIOXANES: STRUCTURE, SOLUBILITY , AND WETTING Joseph Mabry, Andrew Guenthner, Scott Iacono, Raymond Campos, Sean Ramirez, Brian Moore...Crystalline solids • Soluble in fluorinated solvents 5DISTRIBUTION A. Approved for public release; distribution unlimited. • Spin-cast surface of FD

  7. 21 CFR 520.154a - Soluble bacitracin methylene disalicylate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Soluble bacitracin methylene disalicylate. 520.154a Section 520.154a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Soluble bacitracin methylene disalicylate. (a) Specifications. Each pound of soluble powder contains the...

  8. 21 CFR 520.2087 - Roxarsone soluble powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Roxarsone soluble powder. 520.2087 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.2087 Roxarsone soluble powder. (a) Specifications. Each ounce (avoirdupois) of soluble powder contains 21.7 grams of roxarsone...

  9. 21 CFR 520.110 - Apramycin sulfate soluble powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Apramycin sulfate soluble powder. 520.110 Section 520.110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... sulfate soluble powder. (a) Specifications. A water soluble powder used to make a medicated drinking water...

  10. 21 CFR 520.1044c - Gentamicin sulfate soluble powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gentamicin sulfate soluble powder. 520.1044c Section 520.1044c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Gentamicin sulfate soluble powder. (a) Specifications. Each gram of gentamicin sulfate soluble powder...

  11. 21 CFR 524.1580c - Nitrofurazone soluble powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Nitrofurazone soluble powder. 524.1580c Section... § 524.1580c Nitrofurazone soluble powder. (a) Specifications. The drug contains 0.2 percent nitrofurazone in a water-soluble base. (b) Sponsor. See Nos. 000010, 000069, and 050749 in § 510.600(c) of this...

  12. Click strategy using disodium salts of amino acids improves the water solubility of plinabulin and KPU-300.

    Science.gov (United States)

    Yakushiji, Fumika; Muguruma, Kyohei; Hayashi, Yoshiki; Shirasaka, Takuya; Kawamata, Ryosuke; Tanaka, Hironari; Yoshiwaka, Yushi; Taguchi, Akihiro; Takayama, Kentaro; Hayashi, Yoshio

    2017-07-15

    Plinabulin and KPU-300 are promising anti-microtubule agents; however, the low water solubility of these compounds (click strategy using disodium salts of amino acids. The mother skeleton, diketopiperazine (DKP), was transformed into a monolactim-type alkyne and a copper-catalyzed alkyne azide cycloaddition (CuAAC) combined azides that was derived from amino acids as a water-solubilizing moiety. The conversion of carboxyl groups into disodium salts greatly improved the water solubility by 0.8 million times compared to the solubility of the parent molecules. In addition, the α-amino acid side chains of the water-solubilizing moieties affected both the water solubility and the half-lives of the compounds during enzymatic hydrolysis. Our effort to develop a variety of water-soluble derivatives using the click strategy has revealed that the replaceable water-solubilizing moieties can alter molecular solubility and stability under enzymatic hydrolysis. With this flexibility, we are approaching to the in vivo study using water-soluble derivative. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Oral formulation strategies to improve solubility of poorly water-soluble drugs.

    Science.gov (United States)

    Singh, Abhishek; Worku, Zelalem Ayenew; Van den Mooter, Guy

    2011-10-01

    In the past two decades, there has been a spiraling increase in the complexity and specificity of drug-receptor targets. It is possible to design drugs for these diverse targets with advances in combinatorial chemistry and high throughput screening. Unfortunately, but not entirely unexpectedly, these advances have been accompanied by an increase in the structural complexity and a decrease in the solubility of the active pharmaceutical ingredient. Therefore, the importance of formulation strategies to improve the solubility of poorly water-soluble drugs is inevitable, thus making it crucial to understand and explore the recent trends. Drug delivery systems (DDS), such as solid dispersions, soluble complexes, self-emulsifying drug delivery systems (SEDDS), nanocrystals and mesoporous inorganic carriers, are discussed briefly in this review, along with examples of marketed products. This article provides the reader with a concise overview of currently relevant formulation strategies and proposes anticipated future trends. Today, the pharmaceutical industry has at its disposal a series of reliable and scalable formulation strategies for poorly soluble drugs. However, due to a lack of understanding of the basic physical chemistry behind these strategies, formulation development is still driven by trial and error.

  14. Predicting Melting Points of Organic Molecules: Applications to Aqueous Solubility Prediction Using the General Solubility Equation.

    Science.gov (United States)

    McDonagh, J L; van Mourik, T; Mitchell, J B O

    2015-11-01

    In this work we make predictions of several important molecular properties of academic and industrial importance to seek answers to two questions: 1) Can we apply efficient machine learning techniques, using inexpensive descriptors, to predict melting points to a reasonable level of accuracy? 2) Can values of this level of accuracy be usefully applied to predicting aqueous solubility? We present predictions of melting points made by several novel machine learning models, previously applied to solubility prediction. Additionally, we make predictions of solubility via the General Solubility Equation (GSE) and monitor the impact of varying the logP prediction model (AlogP and XlogP) on the GSE. We note that the machine learning models presented, using a modest number of 2D descriptors, can make melting point predictions in line with the current state of the art prediction methods (RMSE≥40 °C). We also find that predicted melting points, with an RMSE of tens of degrees Celsius, can be usefully applied to the GSE to yield accurate solubility predictions (log10 S RMSE<1) over a small dataset of drug-like molecules. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Head-To-Head Comparison of Different Solubility-Enabling Formulations of Etoposide and Their Consequent Solubility-Permeability Interplay.

    Science.gov (United States)

    Beig, Avital; Miller, Jonathan M; Lindley, David; Carr, Robert A; Zocharski, Philip; Agbaria, Riad; Dahan, Arik

    2015-09-01

    The purpose of this study was to conduct a head-to-head comparison of different solubility-enabling formulations, and their consequent solubility-permeability interplay. The low-solubility anticancer drug etoposide was formulated in several strengths of four solubility-enabling formulations: hydroxypropyl-β-cyclodextrin, the cosolvent polyethylene glycol 400 (PEG-400), the surfactant sodium lauryl sulfate, and an amorphous solid dispersion formulation. The ability of these formulations to increase the solubility of etoposide was investigated, followed by permeability studies using the parallel artificial membrane permeability assay (PAMPA) and examination of the consequent solubility-permeability interplay. All formulations significantly increased etoposide's apparent solubility. The cyclodextrin-, surfactant-, and cosolvent-based formulations resulted in a concomitant decreased permeability that could be modeled directly from the proportional increase in the apparent solubility. On the contrary, etoposide permeability remained constant when using the ASD formulation, irrespective of the increased apparent solubility provided by the formulation. In conclusion, supersaturation resulting from the amorphous form overcomes the solubility-permeability tradeoff associated with other formulation techniques. Accounting for the solubility-permeability interplay may allow to develop better solubility-enabling formulations, thereby maximizing the overall absorption of lipophilic orally administered drugs. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  16. How to find soluble proteins: a comprehensive analysis of alpha/beta hydrolases for recombinant expression in E. coli

    Directory of Open Access Journals (Sweden)

    Barth Sandra

    2005-04-01

    Full Text Available Abstract Background In screening of libraries derived by expression cloning, expression of active proteins in E. coli can be limited by formation of inclusion bodies. In these cases it would be desirable to enrich gene libraries for coding sequences with soluble gene products in E. coli and thus to improve the efficiency of screening. Previously Wilkinson and Harrison showed that solubility can be predicted from amino acid composition (Biotechnology 1991, 9(5:443–448. We have applied this analysis to members of the alpha/beta hydrolase fold family to predict their solubility in E. coli. alpha/beta hydrolases are a highly diverse family with more than 1800 proteins which have been grouped into homologous families and superfamilies. Results The predicted solubility in E. coli depends on hydrolase size, phylogenetic origin of the host organism, the homologous family and the superfamily, to which the hydrolase belongs. In general small hydrolases are predicted to be more soluble than large hydrolases, and eukaryotic hydrolases are predicted to be less soluble in E. coli than prokaryotic ones. However, combining phylogenetic origin and size leads to more complex conclusions. Hydrolases from prokaryotic, fungal and metazoan origin are predicted to be most soluble if they are of small, medium and large size, respectively. We observed large variations of predicted solubility between hydrolases from different homologous families and from different taxa. Conclusion A comprehensive analysis of all alpha/beta hydrolase sequences allows more efficient screenings for new soluble alpha/beta hydrolases by the use of libraries which contain more soluble gene products. Screening of hydrolases from families whose members are hard to express as soluble proteins in E. coli should first be done in coding sequences of organisms from phylogenetic groups with the highest average of predicted solubility for proteins of this family. The tools developed here can be used

  17. Task Technical and Quality Assurance Plan for Determining Uranium and Plutonium Solubility in Actual Tank Waste Supernates

    Energy Technology Data Exchange (ETDEWEB)

    King, William D.

    2005-06-28

    Savannah River Site tank waste supernates contain small quantities of dissolved uranium and plutonium. Due to the large volume of supernates, significant quantities of dissolved uranium and plutonium are managed as part of waste transfers, evaporation and pretreatment at the Savannah River Site in tank farm operations, the Actinide Removal Project (ARP), and the Salt Waste Processing Facility (SWPF). Previous SRNL studies have investigated the effect of temperature and major supernate components on the solubility of uranium and plutonium. Based on these studies, equations were developed for the prediction of U and Pu solubility in tank waste supernates. The majority of the previous tests were conducted with simulated waste solutions. The current testing is intended to determine solubility in actual tank waste samples (as-received, diluted, and combinations of tank samples) as a function of composition and temperature. Results will be used to validate and build on the existing solubility equations.

  18. ESOL: estimating aqueous solubility directly from molecular structure.

    Science.gov (United States)

    Delaney, John S

    2004-01-01

    This paper describes a simple method for estimating the aqueous solubility (ESOL--Estimated SOLubility) of a compound directly from its structure. The model was derived from a set of 2874 measured solubilities using linear regression against nine molecular properties. The most significant parameter was calculated logP(octanol), followed by molecular weight, proportion of heavy atoms in aromatic systems, and number of rotatable bonds. The model performed consistently well across three validation sets, predicting solubilities within a factor of 5-8 of their measured values, and was competitive with the well-established "General Solubility Equation" for medicinal/agrochemical sized molecules.

  19. Solubility and thermodynamics of apremilast in different mono solvents: Determination, correlation and molecular interactions.

    Science.gov (United States)

    Shakeel, Faiyaz; Haq, Nazrul; Alanazi, Fars K; Alsarra, Ibrahim A

    2017-05-15

    The solubility data of recently launched poorly soluble antipsoriatic drug apremilast (APM) in any mono solvent or cosolvent mixtures with respect to temperature are not available in literature. Hence, in this research work, the solubility of APM in twelve different mono solvents namely "water, methanol, ethanol, isopropanol (IPA), ethylene glycol (EG), propylene glycol (PG), 1-butanol, 2-butanol, ethyl acetate (EA), dimethyl sulfoxide (DMSO), polyethylene glycol-400 (PEG-400) and Transcutol®" was determined at temperatures "T=298.2K to 318.2K" and pressure "p=0.1 MPa". Eexperimental solubilities of APM in mole fraction were determined by a static equilibrium method using high performance liquid chromatography at 254nm. Experimental solubilities of APM in mole fraction were correlated well with "Van't Hoff and Apelblat models". The solubilities of APM in mole fraction were recorded highest in DMSO (9.91×10-2), followed by EA (2.54×10-2), Transcutol (2.51×10-2), PEG-400 (2.16×10-2),PG (4.01×10-3), EG (1.61×10-3), IPA (4.96×10-4), 1-butanol (4.18×10-4), 2-butanol (3.91×10-4), methanol (2.25×10-4), ethanol (2.20×10-4) and water (1.29×10-6) at "T=318.2K" and similar results were also obtained at each temperature evaluated. The molecular interactions between solute and solvent molecules were evaluated by the determination of activity coefficients. Based on activity coefficients, the higher solute-solvents molecular interactions were recorded in APM-DMSO, APM-EA, APM-Transcutol and APM-PEG-400 in comparison with other combination of solute and solvents. "Apparent standard thermodynamic parameters" of APM indicated an "endothermic and entropy-driven dissolution" of APM in all mono solvents evaluated. Based on these results, APM was proposed as freely soluble in DMSO, EA and Transcutol, sparingly soluble in PEG0-400, slightly soluble in methanol, ethanol, IPA, EG, PG, 1-butanol and 2-butanol and practically insoluble in water. Hence, DMSO, EA and Transcutol

  20. Acyclic cucurbit[n]uril molecular containers enhance the solubility and bioactivity of poorly soluble pharmaceuticals.

    Science.gov (United States)

    Ma, Da; Hettiarachchi, Gaya; Nguyen, Duc; Zhang, Ben; Wittenberg, James B; Zavalij, Peter Y; Briken, Volker; Isaacs, Lyle

    2012-04-15

    The solubility characteristics of 40-70% of new drug candidates are so poor that they cannot be formulated on their own, so new methods for increasing drug solubility are highly prized. Here, we describe a new class of general-purpose solubilizing agents-acyclic cucurbituril-type containers-which increase the solubility of ten insoluble drugs by a factor of between 23 and 2,750 by forming container-drug complexes. The containers exhibit low in vitro toxicity in human liver, kidney and monocyte cell lines, and outbred Swiss Webster mice tolerate high doses of the container without sickness or weight loss. Paclitaxel solubilized by the acyclic cucurbituril-type containers kills cervical and ovarian cancer cells more efficiently than paclitaxel alone. The acyclic cucurbituril-type containers preferentially bind cationic and aromatic drugs, but also solubilize neutral drugs such as paclitaxel, and represent an attractive extension of cyclodextrin-based technology for drug solubilization and delivery.

  1. Amorphous azithromycin with improved aqueous solubility and intestinal membrane permeability.

    Science.gov (United States)

    Aucamp, Marique; Odendaal, Roelf; Liebenberg, Wilna; Hamman, Josias

    2015-01-01

    Azithromycin (AZM) is a poorly soluble macrolide antibacterial agent. Its low solubility is considered as the major contributing factor to its relatively low oral bioavailability. The aim of this study was to improve the solubility of this active pharmaceutical ingredient (API) by preparing an amorphous form by quench cooling of the melt and to study the influence of the improved solubility on membrane permeability. The amorphous azithromycin (AZM-A) exhibited a significant increase in water solubility when compared to the crystalline azithromycin dihydrate (AZM-DH). The influence that the improved solubility could have on membrane permeability was also studied. The apparent permeability coefficient (Papp) values of AZM-A were statistically significantly higher (p solubility of AZM in the amorphous form also produced improved permeability across excised intestinal tissue at physiological pH values found in the small intestine.

  2. Solubility-driven lead optimisation: Recent examples and personal perspectives.

    Science.gov (United States)

    Ahmad, Nadia M

    2016-07-01

    Solubility is recognised as one of the most important physicochemical parameters necessary for a successful clinical candidate. Despite that, there are few articles in the medicinal chemistry literature with a specific focus on solubility-driven optimisation of lead compounds. This could be because the importance of measuring solubilities as part of the optimisation process is relatively underappreciated, or the fact that obtaining sufficient high quality solubility data is difficult. This review gives examples of solubility-driven optimisation programs from the last fifteen years, and explores recent developments in solubility measurement techniques. Quantitative NMR methods are highlighted; these offer the potential to provide high quality solubility measurements in a cost-effective and high-throughput manner. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Characterization of Soluble Organics in Produced Water

    Energy Technology Data Exchange (ETDEWEB)

    Bostick, D.T.

    2002-01-16

    Soluble organics in produced water and refinery effluents represent treatment problems for the petroleum industry. Neither the chemistry involved in the production of soluble organics nor the impact of these chemicals on total effluent toxicity is well understood. The U.S. Department of Energy provides funding for Oak Ridge National Laboratory (ORNL) to support a collaborative project with Shell, Chevron, Phillips, and Statoil entitled ''Petroleum and Environmental Research Forum project (PERF 9844: Manage Water-Soluble Organics in Produced Water''). The goal of this project, which involves characterization and evaluation of these water-soluble compounds, is aimed at reducing the future production of such contaminants. To determine the effect that various drilling conditions might have on water-soluble organics (WSO) content in produced water, a simulated brine water containing the principal inorganic components normally found in Gulf of Mexico (GOM) brine sources was prepared. The GOM simulant was then contacted with as-received crude oil from a deep well site to study the effects of water cut, produced-water pH, salinity, pressure, temperature, and crude oil sources on the type and content of the WSO in produced water. The identities of individual semivolatile organic compounds (SVOCs) were determined in all as-received crude and actual produced water samples using standard USEPA Method (8270C) protocol. These analyses were supplemented with the more general measurements of total petroleum hydrocarbon (TPH) content in the gas (C{sub 6}-C{sub 10}), diesel (C{sub 10}-C{sub 20}), and oil (C{sub 20}-C{sub 28}) carbon ranges as determined by both gas chromatographic (GC) and infrared (IR) analyses. An open liquid chromatographic procedure was also used to differentiate the saturated hydrocarbon, aromatic hydrocarbon, and polar components within the extractable TPH. Inorganic constituents in the produced water were analyzed by ion

  4. Interlaboratory validation of small-scale solubility and dissolution measurements of poorly water-soluble drugs

    DEFF Research Database (Denmark)

    Andersson, Sara B. E.; Alvebratt, Caroline; Bevernage, Jan

    2016-01-01

    The purpose of this study was to investigate the interlaboratory variability in determination of apparent solubility (Sapp) and intrinsic dissolution rate (IDR) using a miniaturized dissolution instrument. Three poorly water-soluble compounds were selected as reference compounds and measured...... at multiple laboratories using the same experimental protocol. Dissolution was studied in fasted-state simulated intestinal fluid and phosphate buffer (pH 6.5). An additional 6 compounds were used for the development of an IDR measurement guide, which was then validated with 5 compounds. The results clearly...

  5. Synthesis of Soluble Fluorene-polyimino Ketone

    Institute of Scientific and Technical Information of China (English)

    LUO,Xuan; CHANG,Guanjun; WANG,Qingfu; JIAO,Wenxiu; ZHANG,Lin; LIN,Runxiong

    2009-01-01

    Based on the 9,9-di(4-anilinyl)fluorene,structurally different fluorene-polyimino ketones have been obtained by the Buchwald-Hartwig cross coupling reaction.Their structure and performance have been characterized by FT-IR,1 H NMR,UV-vis and thermal analysis.The results show an agreement with the proposed structure,which possesses high glass transition temperature (Tg>250 ℃) and good thermal stability with high decomposition temperatures in nitrogen atmosphere (TD>520 ℃).Additionally,the polymers synthesized showed good solubility,which can be dissolved in common organic solvent CHCl3 at room temperature.

  6. Water-soluble titanium alkoxide material

    Science.gov (United States)

    Boyle, Timothy J.

    2010-06-22

    A water soluble, water stable, titanium alkoxide composition represented by the chemical formula (OC.sub.6H.sub.6N).sub.2Ti(OC.sub.6H.sub.2(CH.sub.2N(CH.sub.3).sub.2).sub- .3-2,4,6).sub.2 with a theoretical molecular weight of 792.8 and an elemental composition of 63.6% C, 8.1% H, 14.1% N, 8.1% O and 6.0% Ti.

  7. Solubility of Sulfur Dioxide in Sulfuric Acid

    Science.gov (United States)

    Chang, K. K.; Compton, L. E.; Lawson, D. D.

    1982-01-01

    The solubility of sulfur dioxide in 50% (wt./wt.) sulfuric acid was evaluated by regular solution theory, and the results verified by experimental measurements in the temperature range of 25 C to 70 C at pressures of 60 to 200 PSIA. The percent (wt./wt.) of sulfur dioxide in 50% (wt./wt.) sulfuric acid is given by the equation %SO2 = 2.2350 + 0.0903P - 0.00026P 10 to the 2nd power with P in PSIA.

  8. Combination vaccines

    Directory of Open Access Journals (Sweden)

    David AG Skibinski

    2011-01-01

    Full Text Available The combination of diphtheria, tetanus, and pertussis vaccines into a single product has been central to the protection of the pediatric population over the past 50 years. The addition of inactivated polio, Haemophilus influenzae, and hepatitis B vaccines into the combination has facilitated the introduction of these vaccines into recommended immunization schedules by reducing the number of injections required and has therefore increased immunization compliance. However, the development of these combinations encountered numerous challenges, including the reduced response to Haemophilus influenzae vaccine when given in combination; the need to consolidate the differences in the immunization schedule (hepatitis B; and the need to improve the safety profile of the diphtheria, tetanus, and pertussis combination. Here, we review these challenges and also discuss future prospects for combination vaccines.

  9. Influence of Physiological Gastrointestinal Surfactant Ratio on the Equilibrium Solubility of BCS Class II Drugs Investigated Using a Four Component Mixture Design.

    Science.gov (United States)

    Zhou, Zhou; Dunn, Claire; Khadra, Ibrahim; Wilson, Clive G; Halbert, Gavin W

    2017-12-04

    The absorption of poorly water-soluble drugs is influenced by the luminal gastrointestinal fluid content and composition, which control solubility. Simulated intestinal fluids have been introduced into dissolution testing including endogenous amphiphiles and digested lipids at physiological levels; however, in vivo individual variation exists in the concentrations of these components, which will alter drug absorption through an effect on solubility. The use of a factorial design of experiment and varying media by introducing different levels of bile, lecithin, and digested lipids has been previously reported, but here we investigate the solubility variation of poorly soluble drugs through more complex biorelevant amphiphile interactions. A four-component mixture design was conducted to understand the solubilization capacity and interactions of bile salt, lecithin, oleate, and monoglyceride with a constant total concentration (11.7 mM) but varying molar ratios. The equilibrium solubility of seven low solubility acidic (zafirlukast), basic (aprepitant, carvedilol), and neutral (fenofibrate, felodipine, griseofulvin, and spironolactone) drugs was investigated. Solubility results are comparable with literature values and also our own previously published design of experiment studies. Results indicate that solubilization is not a sum accumulation of individual amphiphile concentrations, but a drug specific effect through interactions of mixed amphiphile compositions with the drug. This is probably due to a combined interaction of drug characteristics; for example, lipophilicity, molecular shape, and ionization with amphiphile components, which can generate specific drug-micelle affinities. The proportion of each component can have a remarkable influence on solubility with, in some cases, the highest and lowest points close to each other. A single-point solubility measurement in a fixed composition simulated media or human intestinal fluid sample will therefore provide a

  10. The levels of water-soluble and triton-soluble Aβ are increased in Alzheimer's disease brain

    Science.gov (United States)

    Mc Donald, Jessica M.; Cairns, Nigel J.; Taylor-Reinwald, Lisa; Holtzman, David; Walsh, Dominic M.

    2012-01-01

    Although plaques composed of the amyloid β-protein (Aβ) are considered a defining feature of Alzheimer's disease (AD), they are also found in cognitively normal individuals and extensive evidence suggests that non-plaque, water-soluble forms of Aβ may play a role in AD pathogenesis. However, the relationship between the levels of water-soluble Aβ and the clinical severity of disease has never been investigated. Here, we present results of a pilot study designed to examine the levels of water-soluble forms of Aβ in brains of individuals who died at clinically distinct stages of AD. Using a serial extraction method, we also investigated the levels of triton-soluble and formic acid-soluble Aβ. We found that water-soluble and detergent-soluble Aβ monomer and SDS-stable dimer were elevated in AD and that the levels of water soluble Aβ did not increase with plaque pathology. These results support the notion that both water- and detergent-soluble Aβ are important in AD and are not simply released from plaques by mechanical disruption. Moreover, the fact that the levels of water- and triton-soluble Aβ were similar in very mild/mild AD and moderate/severe AD suggests that once a certain level of these species is attained, further accumulation is not necessary for the disease to progress. Consequently, therapeutic targeting of water-soluble Aβ should best benefit individuals in earliest phases of the disease process. PMID:22440675

  11. Soluble and insoluble signals sculpt osteogenesis in angiogenesis

    Science.gov (United States)

    Ripamonti, Ugo

    2010-01-01

    The basic tissue engineering paradigm is tissue induction and morphogenesis by combinatorial molecular protocols whereby soluble molecular signals are combined with insoluble signals or substrata. The insoluble signal acts as a three-dimensional scaffold for the initiation of de novo tissue induction and morphogenesis. The osteogenic soluble molecular signals of the transforming growth factor-β (TGF-β) supergene family, the bone morphogenetic/osteogenic proteins (BMPs/OPs) and, uniquely in the non-human primate Papio ursinus (P. ursinus), the three mammalian TGF-β isoforms induce bone formation as a recapitulation of embryonic development. In this paper, I discuss the pleiotropic activity of the BMPs/OPs in the non-human primate P. ursinus, the induction of bone by transitional uroepithelium, and the apparent redundancy of molecular signals initiating bone formation by induction including the three mammalian TGF-β isoforms. Amongst all mammals tested so far, the three mammalian TGF-β isoforms induce endochondral bone formation in the non-human primate P. ursinus only. Bone tissue engineering starts by erecting scaffolds of biomimetic biomaterial matrices that mimic the supramolecular assembly of the extracellular matrix of bone. The molecular scaffolding lies at the hearth of all tissue engineering strategies including the induction of bone formation. The novel concept of tissue engineering is the generation of newly formed bone by the implantation of “smart” intelligent biomimetic matrices that per se initiate the ripple-like cascade of bone differentiation by induction without exogenously applied BMPs/OPs of the TGF-β supergene family. A comprehensive digital iconographic material presents the modified tissue engineering paradigm whereby the induction of bone formation is initiated by intelligent smart biomimetic matrices that per se initiate the induction of bone formation without the exogenous application of the soluble osteogenic molecular signals

  12. Effect of solubility enhancement on nasal absorption of meloxicam.

    Science.gov (United States)

    Horváth, Tamás; Ambrus, Rita; Völgyi, Gergely; Budai-Szűcs, Mária; Márki, Árpád; Sipos, Péter; Bartos, Csilla; Seres, Adrienn B; Sztojkov-Ivanov, Anita; Takács-Novák, Krisztina; Csányi, Erzsébet; Gáspár, Róbert; Szabó-Révész, Piroska

    2016-12-01

    Besides the opioids the standard management of the World Health Organization suggests NSAIDs (non-steroidal anti-inflammatory drugs) alone or in combination to enhance analgesia in malignant and non-malignant pain therapy. The applicability of NSAIDs in a nasal formulation is a new approach in pharmaceutical technology. In order to enhance the nasal absorption of meloxicam (MX) as an NSAID, its salt form, meloxicam potassium monohydrate (MXP), registered by Egis Plc., was investigated in comparison with MX. The physico-chemical properties of the drugs (structural analysis, solubility and dissolution rate) and the mucoadhesivity of nasal formulations were controlled. In vitro and in vivo studies were carried out to determine the nasal applicability of MXP as a drug candidate in pain therapy. It can be concluded that MX and MXP demonstrated the same equilibrium solubility at the pH5.60 of the nasal mucosa (0.017mg/ml); nonetheless, MXP indicated faster dissolution and a higher permeability through the synthetic membrane. The animal studies justified the short Tmax value (15min) and the high AUC of MXP, which is important in acute pain therapy. It can be assumed that the low mucoadhesivity of MXP spray did not increase the residence time in the nasal cavity, and the elimination from the nasal mucosa was therefore faster than in the case of MX. Further experiments are necessary to prove the therapeutic relevance of this MXP-containing innovative intranasal formulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Prevention of chronic renal allograft rejection by soluble CD83.

    Science.gov (United States)

    Lan, Zhu; Lian, Dameng; Liu, Weihua; Arp, Jacqueline; Charlton, Brayden; Ge, Wei; Brand, Stephen; Healey, Don; DeBenedette, Mark; Nicolette, Charles; Garcia, Bertha; Wang, Hao

    2010-12-27

    Recombinant human soluble CD83 had previously exhibited significant immunosuppressive properties that involved interference with dendritic cell maturation in both mouse and humans, inhibition of autoimmunity in mice, and induction of antigen-specific mouse cardiac allograft tolerance when used in combination with other immunosuppressive drugs. Our current research focus turned to examining the effects of peritransplant soluble CD83 (sCD83) administration on prevention of chronic renal allograft rejection. Fisher344-to-Lewis orthotopic rat renal transplants were performed with sequential recipient killing on postoperative days (PODs) 2, 14, and 140 to examine both the acute and chronic effects of peritransplant sCD83 treatment in rat recipients. Recipients treated with sCD83 exhibited a marked decrease in IgM and IgG deposition in the graft and antidonor antibody levels in the circulation, as early as POD14 and persisting until POD140. sCD83 treatment also reduced the infiltration of T cells and monocytes into the graft tissue and inhibited intragraft expression of MyD88 and inflammatory cytokine levels during the observation period. sCD83-treated grafts demonstrated normal histology beyond POD140, including dramatic reductions in tubular atrophy and interstitial fibrosis compared with untreated recipients. We have demonstrated that peritransplant treatment with recombinant sCD83 attenuates both innate and adaptive immune responses and leads to prevention of chronic rejection in a rat renal transplant model. Because sCD83 is of human origin, the therapeutic approach used in our rodent transplant model holds significant promise for clinical transplantation.

  14. Effect of alcohols on lactose solubility.

    Science.gov (United States)

    Majd, F; Nickerson, T A

    1976-06-01

    In tests of effects of high (70 to 90% volume/volume) and low (2 and 5% volume/volume) alcohol concentrations, solubility of lactose decreased with increased alcohol concentration and decreased as alcohol chain length increased. Since lactose has lower solubility in alcohol, crystallization would be expected to be speeded by increased supersaturation. Composition of precipitates formed by the action of ethanol changed with time; alpha-lactose precipitated more rapidly at first, then beta-lactose. Time of crystallization was related directly to the percentage of beta-lactose (therefore, the relation was inverse for total alpha). However, the percentage of alpha-hydrate increased with time and with water content. Agitation during crystallization increased production of beta-lactose. Composition of the lactose precipitate varied greatly with concentration of alcohol (ethanol). When ethanol concentration was low, only alpha-hydrate was precipitated whereas at higher concentrations stable anhydrous alpha lactose also was precipitated, with the percentage of total alpha decreasing while the percentage of beta-lactose increased. Crystal shape changed from prisms initially to partially or fully developed tomahawks as time went by or as the percentage of ethanol decreased, and crystal color increased with crystallization time and as ethanol percentage decreased. Choosing long-chain alcohols and controlling suitable parameters enabled recovery of greater amounts and more desirable forms of lactose.

  15. Soluble manganese removal by porous media filtration.

    Science.gov (United States)

    Kim, J; Jung, S

    2008-12-01

    Filtration experiments were conducted to investigate soluble manganese removal in granular media filtration; sand, manganese oxide coated sand (MOCS), sand + MOCS (1:1) and granular activated carbon (GAC) were used as filter media. Manganese removal, manganese oxide accumulation, turbidity removal, and regeneration of MOCS under various conditions were examined. Soluble manganese removal by the MOCS column was rapid and efficient; most of the removal happened at the top (e.g. 5 cm) of the filter. When filter influent with an average manganese concentration of 0.204 mg l(-1) was fed through the filter columns, the sand + MOCS and MOCS columns removed 98.9% and 99.2% of manganese, respectively. However, manganese removal in sand and the GAC columns was not significant during the initial stage of filtration, but after eight months of filter run they could remove 99% and 35% of manganese, respectively. It was revealed that partial replacement of sand with MOCS showed comparable manganese removal to that of the MOCS filter media.

  16. Statistical investigation of simulated intestinal fluid composition on the equilibrium solubility of biopharmaceutics classification system class II drugs.

    Science.gov (United States)

    Khadra, Ibrahim; Zhou, Zhou; Dunn, Claire; Wilson, Clive G; Halbert, Gavin

    2015-01-25

    A drug's solubility and dissolution behaviour within the gastrointestinal tract is a key property for successful administration by the oral route and one of the key factors in the biopharmaceutics classification system. This property can be determined by investigating drug solubility in human intestinal fluid (HIF) but this is difficult to obtain and highly variable, which has led to the development of multiple simulated intestinal fluid (SIF) recipes. Using a statistical design of experiment (DoE) technique this paper has investigated the effects and interactions on equilibrium drug solubility of seven typical SIF components (sodium taurocholate, lecithin, sodium phosphate, sodium chloride, pH, pancreatin and sodium oleate) within concentration ranges relevant to human intestinal fluid values. A range of poorly soluble drugs with acidic (naproxen, indomethacin, phenytoin, and piroxicam), basic (aprepitant, carvedilol, zafirlukast, tadalafil) or neutral (fenofibrate, griseofulvin, felodipine and probucol) properties have been investigated. The equilibrium solubility results determined are comparable with literature studies of the drugs in either HIF or SIF indicating that the DoE is operating in the correct space. With the exception of pancreatin, all of the factors individually had a statistically significant influence on equilibrium solubility with variations in magnitude of effect between the acidic and basic or neutral compounds and drug specific interactions were evident. Interestingly for the neutral compounds pH was the factor with the second largest solubility effect. Around one third of all the possible factor combinations showed a significant influence on equilibrium solubility with variations in interaction significance and magnitude of effect between the acidic and basic or neutral compounds. The least number of significant media component interactions were noted for the acidic compounds with three and the greatest for the neutral compounds at seven

  17. Carbamazepine solubility enhancement in tandem with swellable polymer osmotic pump tablet: A promising approach for extended delivery of poorly water-soluble drugs

    Directory of Open Access Journals (Sweden)

    Hadjira Rabti

    2014-06-01

    Full Text Available Elementary osmotic pump (EOP is a unique extended release (ER drug delivery system based on the principle of osmosis. It has the ability to minimize the amount of the drug, accumulation and fluctuation in drug level during chronic uses. Carbamazepine (CBZ, a poorly water-soluble antiepileptic drug, has serious side effects on overdoses and chronic uses. The aim of the present study was to design a new EOP tablet of CBZ containing a solubility enhancers and swellable polymer to reduce its side effects and enhance the patient compliance. Firstly, a combination of solubilizing carriers was selected to improve the dissolution of the slightly soluble drug. Then, designing the new EOP tablet and investigating the effect of different variables of core and coat formulations on drug release behavior by single parameter optimization and by Taguchi orthogonal design with analysis of variance (ANOVA, respectively. The results showed that CBZ solubility was successfully enhanced by a minimum amount of combined polyvinyl pyrrolidone (PVP K30 and sodium lauryl sulfate (SLS. The plasticizer amount and molecular weight (MW together with the osmotic agent amount directly affect the release rate whereas the swellable polymer amount and viscosity together with the semi-permeable membrane (SPM thickness inversely influence the release rate. In addition, the tendency of following zero order kinetics was mainly affected by the coat components rather than those of the core. Further, orifice size does not have any significant effect on the release behavior within the range of 0.1 mm to 0.8 mm. In this study we report the successful formulation of CBZ-EOP tablets, which were similar to the marketed product Tegretol CR 200 and able to satisfy the USP criterion limits and to deliver about 80% of CBZ at a rate of approximately zero order for up to 12 h.

  18. Computational methodology for solubility prediction: Application to the sparingly soluble solutes.

    Science.gov (United States)

    Li, Lunna; Totton, Tim; Frenkel, Daan

    2017-06-07

    The solubility of a crystalline substance in the solution can be estimated from its absolute solid free energy and excess solvation free energy. Here, we present a numerical method, which enables convenient solubility estimation of general molecular crystals at arbitrary thermodynamic conditions where solid and solution can coexist. The methodology is based on standard alchemical free energy methods, such as thermodynamic integration and free energy perturbation, and consists of two parts: (1) systematic extension of the Einstein crystal method to calculate the absolute solid free energies of molecular crystals at arbitrary temperatures and pressures and (2) a flexible cavity method that can yield accurate estimates of the excess solvation free energies. As an illustration, via classical Molecular Dynamic simulations, we show that our approach can predict the solubility of OPLS-AA-based (Optimized Potentials for Liquid Simulations All Atomic) naphthalene in SPC (Simple Point Charge) water in good agreement with experimental data at various temperatures and pressures. Because the procedure is simple and general and only makes use of readily available open-source software, the methodology should provide a powerful tool for universal solubility prediction.

  19. Dry season aerosol iron solubility in tropical northern Australia

    Directory of Open Access Journals (Sweden)

    V. H. L. Winton

    2016-10-01

    Full Text Available Marine nitrogen fixation is co-limited by the supply of iron (Fe and phosphorus in large regions of the global ocean. The deposition of soluble aerosol Fe can initiate nitrogen fixation and trigger toxic algal blooms in nitrate-poor tropical waters. We present dry season soluble Fe data from the Savannah Fires in the Early Dry Season (SAFIRED campaign in northern Australia that reflects coincident dust and biomass burning sources of soluble aerosol Fe. The mean soluble and total aerosol Fe concentrations were 40 and 500 ng m−3 respectively. Our results show that while biomass burning species may not be a direct source of soluble Fe, biomass burning may substantially enhance the solubility of mineral dust. We observed fractional Fe solubility up to 12 % in mixed aerosols. Thus, Fe in dust may be more soluble in the tropics compared to higher latitudes due to higher concentrations of biomass-burning-derived reactive organic species in the atmosphere. In addition, biomass-burning-derived particles can act as a surface for aerosol Fe to bind during atmospheric transport and subsequently be released to the ocean upon deposition. As the aerosol loading is dominated by biomass burning emissions over the tropical waters in the dry season, additions of biomass-burning-derived soluble Fe could have harmful consequences for initiating nitrogen-fixing toxic algal blooms. Future research is required to quantify biomass-burning-derived particle sources of soluble Fe over tropical waters.

  20. Cocrystal solubility product analysis - Dual concentration-pH mass action model not dependent on explicit solubility equations.

    Science.gov (United States)

    Avdeef, Alex

    2017-12-15

    A novel general computational approach is described to address many aspects of cocrystal (CC) solubility product (Ksp) determination of drug substances. The CC analysis program, pDISOL-X, was developed and validated with published model systems of various acid-base combinations of active pharmaceutical ingredients (APIs) and coformers: (i) carbamazepine cocrystal systems with 4-aminobenzoic acid, cinnamic acid, saccharin, and salicylic acid, (ii) for indomethacin with saccharin, (iii) for nevirapine with maleic acid, saccharin, and salicylic acid, and (iv) for gabapentin with 3-hydroxybenzoic acid. In all systems but gabapentin, the coformer is much more soluble than the API. The model systems selected are those with available published dual concentration-pH data, one set for the API and one set for the coformer, generally measured at eutectic points (thermodynamically-stable three phases: solution, cocrystal, and crystalline API or coformer). The carbamazepine-cinnamic acid CC showed a substantial elevation in the API equilibrium concentration above pH5, consistent with the formation of a complex between carbamazepine and cinnamate anion. The analysis of the gabapentin:3-hydroxybenzoic acid 1:1 CC system indicated four zones of solid suspensions: coformer (pH5.62). The general approach allows for testing of many possible equilibrium models, including those comprising drug-coformer complexation. The program calculates the ionic strength at each pH. From this, the equilibrium constants are adjusted for activity effects, based on the Stokes-Robinson hydration theory. The complete speciation analysis of the CC systems may provide useful insights into pH-sensitive dissolution effects that could potentially influence bioavailability. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Effect of composition of simulated intestinal media on the solubility of poorly soluble compounds investigated by design of experiments.

    Science.gov (United States)

    Madsen, Cecilie Maria; Feng, Kung-I; Leithead, Andrew; Canfield, Nicole; Jørgensen, Søren Astrup; Müllertz, Anette; Rades, Thomas

    2018-01-01

    The composition of the human intestinal fluids varies both intra- and inter-individually. This will influence the solubility of orally administered drug compounds, and hence, the absorption and efficacy of compounds displaying solubility limited absorption. The purpose of this study was to assess the influence of simulated intestinal fluid (SIF) composition on the solubility of poorly soluble compounds. Using a Design of Experiments (DoE) approach, a set of 24 SIF was defined within the known compositions of human fasted state intestinal fluid. The SIF were composed of phospholipid, bile salt, and different pH, buffer capacities and osmolarities. On a small scale semi-robotic system, the solubility of 6 compounds (aprepitant, carvedilol, felodipine, fenofibrate, probucol, and zafirlukast) was determined in the 24 SIF. Compound specific models, describing key factors influencing the solubility of each compound, were identified. Although all models were different, the level of phospholipid and bile salt, the pH, and the interactions between these, had the biggest influences on solubility overall. Thus, a reduction of the DoE from five to three factors was possible (11-13 media), making DoE solubility studies feasible compared to single SIF solubility studies. Applying this DoE approach will lead to a better understanding of the impact of intestinal fluid composition on the solubility of a given drug compound. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Prediction of the solubility in lipidic solvent mixture: Investigation of the modeling approach and thermodynamic analysis of solubility.

    Science.gov (United States)

    Patel, Shruti V; Patel, Sarsvatkumar

    2015-09-18

    Self-micro emulsifying drug delivery system (SMEDDS) is one of the methods to improve solubility and bioavailability of poorly soluble drug(s). The knowledge of the solubility of pharmaceuticals in pure lipidic solvents and solvent mixtures is crucial for designing the SMEDDS of poorly soluble drug substances. Since, experiments are very time consuming, a model, which allows for solubility predictions in solvent mixtures based on less experimental data is desirable for efficiency. Solvents employed were Labrafil® M1944CS and Labrasol® as lipidic solvents; Capryol-90®, Capryol-PGMC® and Tween®-80 as surfactants; Transcutol® and PEG-400 as co-solvents. Solubilities of both drugs were determined in single solvent systems at temperature (T) range of 283-333K. In present study, we investigated the applicability of the thermodynamic model to understand the solubility behavior of drugs in the lipiodic solvents. By using the Van't Hoff and general solubility theory, the thermodynamic functions like Gibbs free energy, enthalpy and entropy of solution, mixing and solvation for drug in single and mixed solvents were understood. The thermodynamic parameters were understood in the framework of drug-solvent interaction based on their chemical similarity and dissimilarity. Clotrimazole and Fluconazole were used as active ingredients whose solubility was measured in single solvent as a function of temperature and the data obtained were used to derive mathematical models which can predict solubility in multi-component solvent mixtures. Model dependent parameters for each drug were calculated at each temperature. The experimental solubility data of solute in mixed solvent system were measured experimentally and further correlated with the calculates values obtained from exponent model and log-linear model of Yalkowsky. The good correlation was observed between experimental solubility and predicted solubility. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. The solubility of metals in Pb-17Li liquid alloy

    Energy Technology Data Exchange (ETDEWEB)

    Borgstedt, H.U.; Feuerstein, H. (Kernforschungszentrum Karlsruhe GmbH, Inst. fuer Materialforschung, Hauptabteilung Ingenieurtechnik (Germany))

    1992-09-01

    The solubility data of iron in the eutectic alloy Pb-17Li which were evaluated from corrosion tests in a turbulent flow of the molten alloy are discussed in the frame of solubilities of the transition metals in liquid lead. It is shown that the solubility of iron in the alloy is close to that in lead. This is also the fact for several other alloying elements of steels. A comparison of all known data shows that they are in agreement with generally shown trends for the solubility of the transition metals in low melting metals. These trends indicate comparably high solubilities of nickel and manganese in the liquid metals, lower saturation concentration of vanadium, chromium, iron, and cobalt, and extremely low solubility of molybdenum. (orig.).

  4. Dissolution Model of Multiple Species: Leaching of Highly Soluble Minerals

    Science.gov (United States)

    Moreno, Luis; Ordóñez, Javier I.; Cisternas, Luis A.

    2017-06-01

    Dissolution of multi-species from a solid matrix is widely extended in different processes such as leaching of minerals; however, its modeling is often focused on a single species. A model for the simultaneous dissolution of soluble species was developed, which considers different solubilities and dissolution rates and considers that particle collapses when the rapidly soluble species is depleted. The collapsed matter is formed by inert material and a fraction of the soluble species with lower dissolution rate that has not dissolved yet. The model is applied to the leaching of a water-soluble mineral (caliche) with two soluble species dissolving simultaneously with different rates. Measured outlet concentrations of nitrate and magnesium were used to validate the model. Results showed that the model reproduced adequately the leaching of species with rapid and intermediate dissolution rate. Effect of the operating and kinetic parameters on the leaching process is also shown using the actual conditions of heap leaching for caliche mineral.

  5. The effect of autoclaving on soluble protein composition and trypsin inhibitor activity of cracked soybeans

    Directory of Open Access Journals (Sweden)

    Stanojević Slađana P.

    2004-01-01

    Full Text Available The effects of autoclaving conditions (heating for 5, 10 and 15 minutes at 0.5 bars over pressure and oil-extracting temperatures (40°C, 60°C on protein content, composition, and inhibitor activity of cracked soybeans were investigated. The results obtained indicated that oil-extracting method and heat treatment had significant influence on soluble protein content and composition. Raw soybean samples defatted at lower temperature had better solubility (535.42±2.10 mg/g than those obtained by the Soxhlet procedure (345.53±2.80. The same results were obtained for nitrogen solubility index. Autoclaving combined with two oil-extraction methods decreased protein solubility to 180.32±1.50 -245.41±1.41 mg/g, while the dominant component of heat treated flours was 11S fraction. High content of glycinin fraction (44.59-41.10% implies the possible use of treated samples in food industry. Residual activity of treated samples was 43.40-84.26%. Kunitz inhibitor (KTI was responsible for residual inhibitor activity.

  6. Nanocrystals of medium soluble actives--novel concept for improved dermal delivery and production strategy.

    Science.gov (United States)

    Zhai, Xuezhen; Lademann, Jürgen; Keck, Cornelia M; Müller, Rainer H

    2014-08-15

    After use in oral pharmaceutical products, nanocrystals are meanwhile applied to improve the dermal penetration of cosmetic actives (e.g. rutin, hesperidin) and of drugs. By now, nanocrystals are only dermally applied made from poorly soluble actives. The novel concept is to formulate nanocrystals also from medium soluble actives, and to apply a dermal formulation containing additionally nanocrystals. The nanocrystals should act as fast dissolving depot, increase saturation solubility and especially accumulate in the hair follicles, to further increase skin penetration. Caffeine was used as model compound with relevance to market products, and a particular process was developed for the production of caffeine nanocrystals to overcome the supersaturation related effect of crystal growth and fiber formation - typical with medium soluble compounds. It is based on low energy milling (pearl milling) in combination with low dielectric constant dispersion media (water-ethanol or ethanol-propylene glycol mixtures) and optimal stabilizers. Most successful was Carbopol(®) 981 (e.g. 20% caffeine in ethanol-propylene glycol 3:7 with 2% Carbopol, w/w). Nanocrystals with varied sizes can now be produced in a controlled process e.g. 660 nm (optimal for hair follicle accumulation) to 250 nm (optimal for fast dissolution). The short term test proved stability over 2 months of the present formulation being sufficient to perform in vivo testing of the novel concept. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Microscopic Structure and Solubility Predictions of Multifunctional Solids in Supercritical Carbon Dioxide: A Molecular Simulation Study.

    Science.gov (United States)

    Noroozi, Javad; Paluch, Andrew S

    2017-02-23

    Molecular dynamics simulations were employed to both estimate the solubility of nonelectrolyte solids, such as acetanilide, acetaminophen, phenacetin, methylparaben, and lidocaine, in supercritical carbon dioxide and understand the underlying molecular-level driving forces. The solubility calculations involve the estimation of the solute's limiting activity coefficient, which may be computed using conventional staged free-energy calculations. For the case of lidocaine, wherein the infinite dilution approximation is not appropriate, we demonstrate how the activity coefficient at finite concentrations may be estimated without additional effort using the dilute solution approximation and how this may be used to further understand the solvation process. Combining with experimental pure-solid properties, namely, the normal melting point and enthalpy of fusion, solubilities were estimated. The results are in good quantitative agreement with available experimental data, suggesting that molecular simulations may be a powerful tool for understanding supercritical processes and the design of carbon dioxide-philic molecular systems. Structural analyses were performed to shed light on the microscopic details of the solvation of different functional groups by carbon dioxide and the observed solubility trends.

  8. Prediction of pH-dependent aqueous solubility of druglike molecules

    DEFF Research Database (Denmark)

    Hansen, Niclas Tue; Kouskoumvekaki, Irene; Jørgensen, Flemming Steen

    2012-01-01

    In the present work, the Henderson-Hasselbalch (HH) equation has been employed for the development of a tool for the prediction of pH-dependent aqueous solubility of drugs and drug candidates. A new prediction method for the intrinsic solubility was developed, based on artificial neural networks...... that have been trained on a druglike PHYSPROP subset of 4548 compounds. For the prediction of acid/base dissociation coefficients, the commercial tool Marvin has been used, following validation on a data set of 467 molecules from the PHYSPROP database. The best performing network for intrinsic solubility...... predictions has a cross-validated root mean square error (RMSE) of 0.70 log S-units, while the Marvin pKa plug-in has an RMSE of 0.71 pH-units. A data set of 27 drugs with experimentally determined pH-solubility curves was assembled from the literature for the validation of the combined pH-dependent model...

  9. Soluble Expression and Characterization of Biologically Active Bacillus anthracis Protective Antigen in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Nagendra Suryanarayana

    2016-01-01

    Full Text Available Bacillus anthracis secretory protein protective antigen (PA is primary candidate for subunit vaccine against anthrax. Attempts to obtain large quantity of PA from Escherichia coli expression system often result in the formation of insoluble inclusion bodies. Therefore, it is always better to produce recombinant proteins in a soluble form. In the present study, we have obtained biologically active recombinant PA in small scale E. coli shake culture system using three different expression constructs. The PA gene was cloned in expression vectors bearing trc, T5, and T7 promoters and transformed into their respective E. coli hosts. The growth conditions were optimized to obtain maximum expression of PA in soluble form. The expression construct PA-pET32c in DE3-pLysS E. coli host resulted in a maximum production of soluble PA (15 mg L−1 compared to other combinations. Purified PA was subjected to trypsin digestion and binding assay with lethal factor to confirm the protein’s functionality. Biological activity was confirmed by cytotoxicity assay on J774.1 cells. Balb/c mice were immunized with PA and the immunogenicity was tested by ELISA and toxin neutralization assay. This study highlights the expression of soluble and biologically active recombinant PA in larger quantity using simpler E. coli production platform.

  10. Novel Organo-Soluble Optically Tunable Chiral Hybrid Gold Nanorods

    Science.gov (United States)

    2014-12-04

    soluble porphyrin mixed monolayer-protected GNRs, porphyrin Zn, Cu and Mg complex monolayer-protected GNRs, and organo-soluble perylene thiol monolayer...254 nm for 0 (blue), 5 min (pink), 10 min (yellow), 15 min (green), and 20 min (red). Organo-soluble porphyrin mixed monolayer-protected gold...nanorods were, for the first time, synthesized and characterized. The resulting gold nanorods (GNRs) encapsulated by both porphyrin thiol and alkyl thiol

  11. Thermodynamics of sulfanilamide solubility in propylene glycol + water mixtures

    OpenAIRE

    Martínez, Fleming; Romdhani, Asma; Delgado, Daniel R.

    2011-01-01

    The solubility of sulfanilamide (SA) in propylene glycol + water cosolvent mixtures was determined at temperatures from 293.15 to 313.15 K. The thermodynamic functions: Gibbs energy, enthalpy, and entropy of solution and mixing were obtained from these solubility data by using the van’t Hoff and Gibbs equations. The solubility was maximal in propylene glycol and very low in water at all the temperatures. A non linear enthalpy–entropy relationship was observed from a plot of enthal...

  12. Formulation and Evaluation of Hydrotropic Solublization Based Suspensions of Griseofulvin

    OpenAIRE

    A. S. Shete,; Yadav, A. V.; A.P. Dabke; Sakhare, S. S.

    2010-01-01

    Purpose: Hydrotropes increases the solubility of organics in water. Objective of present investigation was to enhance the solubility of griseofulvin using the technique of hydrotropic solubilization technique and convert them into suitable oral liquid dosage form (suspension) useful for enhancement of bioavailability. Methods: 0.5M, 1M, 2M of the hydrotropes (tri sodium citrate, urea, sodium acetate, sodium benzoate and sodium salicylates) were used to study the saturation solubility. Solubil...

  13. Aqueous solubilities of phenol derivatives by conductivity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Achard, C.; Jaoui, M.; Schwing, M.; Rogalski, M. [Univ. de Metz (France). Lab. de Thermodynamique et d`Analyse Chimique

    1996-05-01

    The aqueous solubilities of five chlorophenols and three nitrophenols were measured by conductimetry at temperatures between 15 and 48C. The solubilities of 2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol, 2-nitrophenol, 4-nitrophenol, and 2,4-dinitrophenol were studied. Automatic conductivity measurements allow the determination of the solute concentration and, hence, the determination of the solubility. Emulsion formation can also be followed. Results obtained are in good agreement with literature values.

  14. DEVELOPMENT OF PETROLUEM RESIDUA SOLUBILITY MEASUREMENT METHODOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Per Redelius

    2006-03-01

    In the present study an existing spectrophotometry system was upgraded to provide high-resolution ultraviolet (UV), visible (Vis), and near infrared (NIR) analyses of test solutions to measure the relative solubilities of petroleum residua dissolved in eighteen test solvents. Test solutions were prepared by dissolving ten percent petroleum residue in a given test solvent, agitating the mixture, followed by filtration and/or centrifugation to remove insoluble materials. These solutions were finally diluted with a good solvent resulting in a supernatant solution that was analyzed by spectrophotometry to quantify the degree of dissolution of a particular residue in the suite of test solvents that were selected. Results obtained from this approach were compared with spot-test data (to be discussed) obtained from the cosponsor.

  15. Soluble serum Klotho levels in healthy subjects

    DEFF Research Database (Denmark)

    Pedersen, Lise Mariager; Pedersen, Susanne Møller; Brasen, Claus Lohman

    2013-01-01

    Klotho concentrations were determined in 120 healthy adults aged 19-66years. Blood samples were collected, and stored sera were assayed for Klotho according to age and gender. In addition several other clinical and laboratory characteristics were determined in the cohort and compared to the levels......OBJECTIVE: Soluble serum Klotho, is a new biomarker linked to chronic kidney disease, cardiovascular disease and diabetes. This study describes the evaluation and comparison of two different immunoassays and establishment of assay specific reference intervals in adults. Design and methods Serum...... of serum Klotho. RESULTS: Serum Klotho levels were significantly higher in time-resolved fluorescence immunoassay (TRF) compared to an ELISA (IBL) and no correlation were found between the assays. No signal was obtained in either assay when the standard curve was switched between the two different...

  16. combination Dictionary

    African Journals Online (AJOL)

    rbr

    advanced-level Spanish-speaking EFL learners. 2. Word combinations ... a certain process of segregation as a separate branch of linguistics. While lexi- ... As substantiated by Ilson's investigation of lexicographic practices, most dictionaries ...

  17. Solubility of Helium in Olivine at 1 Atmosphere

    Science.gov (United States)

    Parman, S. W.; Kurz, M. D.; Hart, S. R.; Grove, T. L.

    2004-12-01

    careful examination of the experimental materials indicate that the gas released during crushing is not trapped in bubbles or inclusions, but is loosely bound within the crystal lattice. Where it resides in the olivine crystal structure is not clear. Using only the gas released by melting, along with published solubilities of He in basaltic melts [4], the ol/melt DHe is 0.003(+/-0.001) at 1 atm. This is most likely an upper limit because the crushing experiments may not have completely eliminated the loosely bound helium. If the gas from both the crushing and melting steps are combined, the apparent DHe is 0.006(+/-0.001). We caution against extrapolating these preliminary values to mantle melting conditions until the location of He in olivine is identified and the effects of pressure and temperature are quantified. [1] Broadhurst et al. (1990) GCA 54: 299-309 [2] Hiyagon and Ozima (1986) GCA 50: 2045-2057 [3] Brooker et al. (2003) Nature 423: 738-741 [4] Jambon et al. (1986) GCA 50: 401-408

  18. Soluble adhesion molecules as markers for sepsis and the potential pathophysiological discrepancy in neonates, children and adults

    Science.gov (United States)

    2014-01-01

    Sepsis is a severe and life-threatening systemic inflammatory response to infection that affects all populations and age groups. The pathophysiology of sepsis is associated with aberrant interaction between leukocytes and the vascular endothelium. As inflammation progresses, the adhesion molecules that mediate these interactions become shed from cell surfaces and accumulate in the blood as soluble isoforms that are being explored as potential prognostic disease biomarkers. We critically review the studies that have tested the predictive value of soluble adhesion molecules in sepsis pathophysiology with emphasis on age, as well as the underlying mechanisms and potential roles for inflammatory shedding. Five soluble adhesion molecules are associated with sepsis, specifically, E-selectin, L-selectin and P-selectin, intercellular adhesion molecule-1 and vascular cell adhesion molecule-1. While increased levels of these soluble adhesion molecules generally correlate well with the presence of sepsis, their degree of elevation is still poorly predictive of sepsis severity scores, outcome and mortality. Separate analyses of neonates, children and adults demonstrate significant age-dependent discrepancies in both basal and septic levels of circulating soluble adhesion molecules. Additionally, a range of both clinical and experimental studies suggests protective roles for adhesion molecule shedding that raise important questions about whether these should positively or negatively correlate with mortality. In conclusion, while predictive properties of soluble adhesion molecules have been researched intensively, their levels are still poorly predictive of sepsis outcome and mortality. We propose two novel directions for improving clinical utility of soluble adhesion molecules: the combined simultaneous analysis of levels of adhesion molecules and their sheddases; and taking age-related discrepancies into account. Further attention to these issues may provide better

  19. On barium oxide solubility in barium-containing chloride melts

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaeva, Elena V.; Zakiryanova, Irina D.; Bovet, Andrey L.; Korzun, Iraida V. [Ural Federal Univ., Yekaterinburg (Russian Federation). Inst. of High Temperature Electrochemistry

    2016-11-01

    Oxide solubility in chloride melts depends on temperature and composition of molten solvent. The solubility of barium oxide in the solvents with barium chloride content is essentially higher than that in molten alkali chlorides. Spectral data demonstrate the existence of oxychloride ionic groupings in such melts. This work presents the results of the BaO solubility in two molten BaCl{sub 2}-NaCl systems with different barium chloride content. The received data together with earlier published results revealed the main regularities of BaO solubility in molten BaO-BaCl{sub 2}-MCl systems.

  20. IUPAC-NIST Solubility Data Series. 76. Solubility of Ethyne in Liquids

    Science.gov (United States)

    Fogg, Peter G. T.; Bligh, Sim-wan Annie; Derrick, M. Elizabeth; Yampol'skii, Yuri P.; Clever, H. Lawrence; Skrzecz, Adam; Young, Colin L.; Fogg, Peter G. T.

    2001-11-01

    Ethyne was probably first made in the laboratory by Edmund Davy in 1836. It was rediscovered nearly a quarter of a century later by Berthelot who gave it the name acetylene. Since that time ethyne has become a cheap raw material for the synthesis of organic materials and an important industrial fuel. A summary of the available solubility data for ethyne was published by Miller in 1965 [S. A Miller, Acetylene—Its Properties, Manufacture, and Uses (Academic, New York, 1965), Vol. I]. Many more data are now available in a wide range of research papers and patent applications. These data vary in their reliability. In the current work the data for systems included in Miller's book have been reassessed and complemented by data published more recently. Literature has been surveyed to 1999. Data for a system may be unreliable unless two or more groups of workers have published values in close agreement. Where possible values of the mole fraction solubility at a partial pressure of 101.3 kPa have been tabulated. Equations have been given for the variation of mole fraction with temperature in cases in which values over a temperature range are available. The greater the number of independent sources of the data the more the reliance which can be placed on the utility of the resulting equation. Extrapolation of such equations beyond the temperature range of experimental measurements can lead to errors. In many of the systems it may be assumed that approximate values of the mole fraction solubility, x1, at a partial pressure of 101.3 kPa may be obtained by linear extrapolation of values for lower partial pressures, p1, on the assumption that x1/p1 is approximately constant. However a similar linear extrapolation of solubilities at pressures appreciably higher that 101.3 kPa to give mole fraction solubilities at 101.3 kPa can lead to gross errors. For the purpose of evaluation of data use has been made of the Krichevsky-Il'inskaya equation to obtain approximate values of

  1. A docking approach to the study of copper trafficking proteins: interaction between metallochaperones and soluble domains of copper ATPases

    NARCIS (Netherlands)

    Arnesano, F.; Banci, L.; Bertini, I.; Bonvin, A.M.J.J.|info:eu-repo/dai/nl/113691238

    2004-01-01

    A structural model of the transient complex between the yeast copper chaperone Atx1 and the first soluble domain of the copper transporting ATPase Ccc2 was obtained with HADDOCK, combining NMR chemical shift mapping information with in silico docking. These two proteins are involved in copper

  2. Improving co-amorphous drug formulations by the addition of the highly water soluble amino acid proline

    DEFF Research Database (Denmark)

    Jensen, Katrine Birgitte Tarp; Löbmann, Korbinian; Rades, Thomas

    2014-01-01

    by combining the model drug, naproxen (NAP), with an amino acid to physically stabilize the co-amorphous system (tryptophan, TRP, or arginine, ARG) and a second highly soluble amino acid (proline, PRO) for an additional improvement of the dissolution rate. Co-amorphous drug-amino acid blends were prepared...

  3. [Effects of snow cover on water soluble and organic solvent soluble components during foliar litter decomposition in an alpine forest].

    Science.gov (United States)

    Xu, Li-Ya; Yang, Wan-Qin; Li, Han; Ni, Xiang-Yin; He, Jie; Wu, Fu-Zhong

    2014-11-01

    Seasonal snow cover may change the characteristics of freezing, leaching and freeze-thaw cycles in the scenario of climate change, and then play important roles in the dynamics of water soluble and organic solvent soluble components during foliar litter decomposition in the alpine forest. Therefore, a field litterbag experiment was conducted in an alpine forest in western Sichuan, China. The foliar litterbags of typical tree species (birch, cypress, larch and fir) and shrub species (willow and azalea) were placed on the forest floor under different snow cover thickness (deep snow, medium snow, thin snow and no snow). The litterbags were sampled at snow formation stage, snow cover stage and snow melting stage in winter. The results showed that the content of water soluble components from six foliar litters decreased at snow formation stage and snow melting stage, but increased at snow cover stage as litter decomposition proceeded in the winter. Besides the content of organic solvent soluble components from azalea foliar litter increased at snow cover stage, the content of organic solvent soluble components from the other five foliar litters kept a continue decreasing tendency in the winter. Compared with the content of organic solvent soluble components, the content of water soluble components was affected more strongly by snow cover thickness, especially at snow formation stage and snow cover stage. Compared with the thicker snow covers, the thin snow cover promoted the decrease of water soluble component contents from willow and azalea foliar litter and restrain the decrease of water soluble component content from cypress foliar litter. Few changes in the content of water soluble components from birch, fir and larch foliar litter were observed under the different thicknesses of snow cover. The results suggested that the effects of snow cover on the contents of water soluble and organic solvent soluble components during litter decomposition would be controlled by

  4. Screening of process variables to enhance the solubility of famotidine with 2-HydroxyPropyl-β-Cyclodextrin & PVP K-30 by using Plackett-Burman design approach.

    Science.gov (United States)

    Verma, Umakant; Naik, Jitendra B; Patil, Jayesh S; Yadava, Sunil K

    2017-08-01

    In the present work, inclusion complex of famotidine (FMT) was prepared with (2-HydroxyPropyl)-β-Cyclodextrin (HP-β-CyD) and polyvinylpyrrolidone K-30 (PVP K-30) by spray drying technique to enhance the solubility of famotidine. FMT is a potent histamine H 2 -receptor antagonist having low solubility as well as oral bioavailability. In order to enhance the solubility of FMT, a quality by design (QbD) approach has been used by employing Plackett-Burman design (PBD). With the application of PBD, seven independent process variables were investigated and optimized for maximum solubility. The developed inclusion complex was characterized for solubility, encapsulation efficiency, FTIR, FESEM, XRD. In-vitro drug release study was also performed by preparing fast dissolving tablets of inclusion complex. Solubility of FMT in prepared complex was found 38 fold higher than pure FMT while %EE was found 92.10%. Statistical analysis of the data (ANOVA) indicates an adequate model fitting predicting the effect of process parameters affecting the solubility. In conclusion, spray dried inclusion complex can effectively increases the solubility as well as dissolution rate of the FMT and other active pharmaceutical ingredients in combination of the fast dissolving tablets. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Statistical investigation of the full concentration range of fasted and fed simulated intestinal fluid on the equilibrium solubility of oral drugs.

    Science.gov (United States)

    Perrier, Jeremy; Zhou, Zhou; Dunn, Claire; Khadra, Ibrahim; Wilson, Clive G; Halbert, Gavin

    2018-01-01

    Upon oral administration the solubility of a drug in intestinal fluid is a key property influencing bioavailability. It is also recognised that simple aqueous solubility does not reflect intestinal solubility and to optimise in vitro investigations simulated intestinal media systems have been developed. Simulated intestinal media which can mimic either the fasted or fed state consists of multiple components each of which either singly or in combination may influence drug solubility, a property that can be investigated by a statistical design of experiment technique. In this study a design of experiment covering the full range from the lower limit of fasted to the upper limit of fed parameters and using a small number of experiments has been performed. The measured equilibrium solubility values are comparable with literature values for simulated fasted and fed intestinal fluids as well as human fasted and fed intestinal fluids. The equilibrium solubility data range is statistically equivalent to a combination of published fasted and fed design of experiment data in six (indomethacin, phenytoin, zafirlukast, carvedilol, fenofibrate and probucol) drugs with three (aprepitant, tadalafil and felodipine) drugs not equivalent. In addition the measured equilibrium solubility data sets were not normally distributed. Further studies will be required to determine the reasons for these results however it implies that a single solubility measurement without knowledge of the solubility distribution will be of limited value. The statistically significant media factors which promote equilibrium solubility (pH, sodium oleate and bile salt) were in agreement with published results but the number of determined significant factors and factor interactions was fewer in this study, lecithin for example did not influence solubility. This may be due to the reduction in statistical sensitivity from the lower number of experimental data points or the fact that using the full range will

  6. The coagulation characteristics of humic acid by using acid-soluble chitosan, water-soluble chitosan, and chitosan coagulant mixtures.

    Science.gov (United States)

    Chen, Chih-Yu; Wu, Chung-Yu; Chung, Ying-Chien

    2015-01-01

    Chitosan is a potential substitute for traditional aluminium salts in water treatment systems. This study compared the characteristics of humic acid (HA) removal by using acid-soluble chitosan, water-soluble chitosan, and coagulant mixtures of chitosan with aluminium sulphate (alum) or polyaluminium chloride (PACl). In addition, we evaluated their respective coagulation efficiencies at various coagulant concentrations, pH values, turbidities, and hardness levels. Furthermore, we determined the size and settling velocity of flocs formed by these coagulants to identify the major factors affecting HA coagulation. The coagulation efficiency of acid- and water-soluble chitosan for 15 mg/l of HA was 74.4% and 87.5%, respectively. The optimal coagulation range of water-soluble chitosan (9-20 mg/l) was broader than that of acid-soluble chitosan (4-8 mg/l). Notably, acid-soluble chitosan/PACl and water-soluble chitosan/alum coagulant mixtures exhibited a higher coagulation efficiency for HA than for PACl or alum alone. Furthermore, these coagulant mixtures yielded an acceptable floc settling velocity and savings in both installation and operational expenses. Based on these results, we confidently assert that coagulant mixtures with a 1:1 mass ratio of acid-soluble chitosan/PACl and water-soluble chitosan/alum provide a substantially more cost-effective alternative to using chitosan alone for removing HA from water.

  7. Solubility of vanadyl sulfate in concentrated sulfuric acid solutions

    Science.gov (United States)

    Rahman, F.; Skyllas-Kazacos, M.

    The specific energy of the vanadium redox battery is determined by the solubility of the four vanadium oxidation states in sulfuric acid. While recent studies have shown that a higher vanadium concentration than that initially proposed might be feasible, further reliable solubility data for the various vanadium ions is required if the electrolyte composition is to be properly optimized. This study describes the results of a solubility study of vanadyl sulfate in sulfuric acid. VOSO 4 is the species which exists in the discharged positive half-cell of the vanadium redox cell. The solubility data have been generated in sulfuric acid concentrations that range from 0 to 9 mol/l and at temperatures between 10 and 50°C. The solubility of VOSO 4 is found to decrease continuously with increasing H 2SO 4 concentration and decreasing temperature. At 20°C, the solubility of VOSO 4 in distilled water is 3.280 mol/l whereas in 9 M H 2SO 4 it is 0.260 mol/l. The drop in solubility with increasing H 2SO 4 concentration is significant and is more pronounced at lower concentrations. A multivariable solubility prediction model has been developed as a function of temperature and total sulfate/bisulfate (SO 42- and HSO 4-) concentration using the extended Debye-Huckel functional form. The average absolute deviation of the predicted solubility values from experimental data is 4.5% with a maximum deviation of about 12% over the abovementioned temperature and sulfuric acid concentration range. When solubility data in the more useful H 2SO 4 concentration range of 3-7 M is considered, the solubility correlation improved with an average absolute deviation of only 3.0% and a maximum deviation of about 7%.

  8. A new synthetic methodology for the preparation of biocompatible and organo-soluble barbituric- and thiobarbituric acid based chitosan derivatives for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Shahzad, Sohail [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Shahzadi, Lubna [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Mahmood, Nasir [Department of Allied Health Sciences and Chemical Pathology, Department of Human Genetics and Molecular Biology, University of Health Sciences, Lahore (Pakistan); Siddiqi, Saadat Anwar [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Rauf, Abdul [Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Manzoor, Faisal; Chaudhry, Aqif Anwar [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Rehman, Ihtesham ur [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Materials Science and Engineering, The Kroto Research Institute, The University of Sheffield, North Campus, Broad Lane, Sheffield, S3 7HQ (United Kingdom); Yar, Muhammad, E-mail: drmyar@ciitlahore.edu.pk [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan)

    2016-09-01

    Chitosan's poor solubility especially in organic solvents limits its use with other organo-soluble polymers; however such combinations are highly required to tailor their properties for specific biomedical applications. This paper describes the development of a new synthetic methodology for the synthesis of organo-soluble chitosan derivatives. These derivatives were synthesized from chitosan (CS), triethyl orthoformate and barbituric or thiobarbituric acid in the presence of 2-butannol. The chemical interactions and new functional motifs in the synthesized CS derivatives were evaluated by FTIR, DSC/TGA, UV/VIS, XRD and {sup 1}H NMR spectroscopy. A cytotoxicity investigation for these materials was performed by cell culture method using VERO cell line and all the synthesized derivatives were found to be non-toxic. The solubility analysis showed that these derivatives were readily soluble in organic solvents including DMSO and DMF. Their potential to use with organo-soluble commercially available polymers was exploited by electrospinning; the synthesized derivatives in combination with polycaprolactone delivered nanofibrous membranes. - Highlights: • Development of a new synthetic methodology • Synthesis of organo-soluble chitosan (CS) derivatives • VERO cells proliferation • Nanofibrous membranes from the synthesized chitosan derivatives and polycaprolactone.

  9. Neutrophil Fc gamma and complement receptors involved in binding soluble IgG immune complexes and in specific granule release induced by soluble IgG immune complexes.

    Science.gov (United States)

    Voice, J K; Lachmann, P J

    1997-10-01

    We examined the effect of soluble IgG immune complex (IC) characteristics on the binding of IC to human neutrophils and IC-induced specific granule release of neutrophils via Fc gamma receptors (CD16 and CD32) and complement receptors (CR1 and CR3). A set of soluble IgG IC varying in size, IgG subclass, antigen epitope density and complement (C) incorporation were formed between 5-iodo-4-hydroxy-3-nitrophenacetyl (NIP) coupled to bovine serum albumin (BSA) and chimeric mouse-human anti-NIP monoclonal antibodies (mAb) of all four IgG subclasses. High and low epitope density IC of all four IgG subclasses induced specific granule release with C, but in the absence of C only IgG1 and IgG3 IC were functionally active. The Fc gamma and C receptors responsible for IgG IC-induced specific granule release and IC binding were determined using mAb specific for the ligand binding sites of CD16, CD32 and CR3, and recombinant soluble CR1. Each defined IC displayed a unique pattern of receptor preference, dependent upon subclass and antigenic epitope density. IC binding and IC-induced specific granule release was not mediated by the same receptor, or combination of receptors. High and low epitope density IgG3 IC binding and induction of specific granule release was mediated predominantly via CD16. Other IC subclasses bound differently, i.e. IgG1 IC used CD16 and CR3; IgG2 and IgG4 predominantly used complement receptors; but all three induced specific granule release via CD32. In vivo these results may translate into differential activation of neutrophils by soluble IC dependent upon their characteristics, leading to subtle nuances in the etiology, pathology and control of the immune response in IC-related diseases.

  10. Development of a chitosan-derivative micellar formulation to improve celecoxib solubility and bioavailability.

    Science.gov (United States)

    Mennini, Natascia; Furlanetto, Sandra; Bragagni, Marco; Ghelardini, Carla; Di Cesare Mannelli, Lorenzo; Mura, Paola

    2014-11-01

    Celecoxib is an anti-inflammatory drug, specific inhibitor of COX-2, classified as a BCS class II compound due to its very low aqueous solubility (3 μg/mL) and good permeability. An innovative micellar formulation of celecoxib has been developed to increase its solubility and, consequently, its oral bioavailability. Quaternary-ammonium-palmitoyl-glycol-chitosan (GCPQ) was selected as carrier, due to its micelle-forming ability joined to its solubilizing and enhancer properties towards hydrophobic drugs. A Doehlert design was applied to optimize the drug solubilizing efficiency of the micellar formulation. Tested factors were GCPQ concentration and time and power of probe sonication during micelles formation; the response to maximize was the celecoxib solubility. The response-surface study allowed a thorough investigation of the effect of factors variations on the response over the considered experimental domain and identification of the best variable combination in order to maximize the desired improvement in drug solubility. The optimized micellar formulation (GCPQ 4.5 mg/mL; 25 min at 60% power of probe sonication) enabled an about 60-fold increase in celecoxib aqueous solubility. The optimized formulation, tested in vivo in mice by the writhing test, allowed a statistically significant shortening (p < 0.05) of the pain alleviation onset and a more intense effect (p < 0.05) with respect to the celecoxib aqueous suspension obtained by the commercial formulation. The results proved that the developed GCPQ micellar formulation is a valuable approach for improving the therapeutic effectiveness of celecoxib.

  11. Relationship between swelling of hydroxypropylmethylcellulose and the Hansen and Karger partial solubility parameters.

    Science.gov (United States)

    Navarro-Lupión, Francisco-Javier; Bustamante, Pilar; Escalera, Begoña

    2005-07-01

    A model that relates the equilibrium swelling of hydroxypropylmethylcellulose to the partial solubility parameters of both the polymer and the solvents is proposed to interpret and correlate the experimental data. The non-specific interactions are expressed as the dispersion delta(d) and polar delta(p) solubility parameters of Hansen, or as a combination of both. Hydrogen bonding is represented by the acidic delta(a) and the basic delta(b) Karger solubility parameters. The results are compared with models including the same parameters for non-specific interactions (delta(d) and delta(p)) and the Hansen hydrogen bonding parameter delta(h). Equilibrium swelling of this hydrophilic polymer that is widely used in drug formulation is measured in pure solvents covering a wide polarity range. In a qualitative way, swelling increases in solvents with higher Hildebrand solubility parameters and stronger hydrogen bonding capability, and it decreases in non-polar solvents. Single polarity indexes, such as the Hildebrand solubility parameter or the partition coefficient (PC), do not fit well the overall experimental data. The best correlations were obtained with the proposed model, providing at the same time an interpretation consistent with the physical meaning of the terms included in the equation. Swelling increases as the non-specific interactions of the polymer and the solvents become alike, and as the Lewis acid-base interactions of the polymer (1) and the solvent (2) represented by the products delta(1a)delta(2b) and delta(1b)delta(2a) become greater. Conversely, hydrogen bonding self association of the solvents (the product delta(1a)delta(1b)) lowers swelling. The results show that the Karger hydrogen bonding parameters provide a better approach than the Hansen hydrogen bonding parameter to correlate the swelling behavior of a hydrophilic polymer. (c) 2005 Wiley-Liss, Inc.

  12. Characterization of Peptide Antibodies by Epitope Mapping Using Resin-Bound and Soluble Peptides.

    Science.gov (United States)

    Trier, Nicole Hartwig

    2015-01-01

    Characterization of peptide antibodies through identification of their target epitopes is of utmost importance. Understanding antibody specificity at the amino acid level provides the key to understand the specific interaction between antibodies and their epitopes and their use as research and diagnostic tools as well as therapeutic agents. This chapter describes a straightforward strategy for mapping of continuous peptide antibody epitopes using resin-bound and soluble peptides. The approach combines three different types of peptide sets for full characterization of peptide antibodies: (1) overlapping peptides, used to locate antigenic regions; (2) truncated peptides, used to identify the minimal peptide length required for antibody binding; and (3) substituted peptides, used to identify the key residues important for antibody binding and to determine the specific contribution of key residues. For initial screening resin-bound peptides are used for epitope estimation, while soluble peptides subsequently are used for fine mapping. The combination of resin-bound peptides and soluble peptides for epitope mapping provides a time-sparing and straightforward approach for characterization of peptide antibodies.

  13. Production of soluble Neprilysin by endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Kuruppu, Sanjaya, E-mail: Sanjaya.Kuruppu@monash.edu [Department of Biochemistry and Molecular Biology, Building 77, Monash University, Wellington Rd, Clayton, Vic 3800 (Australia); Rajapakse, Niwanthi W. [Department of Physiology, Building 13F, Monash University, Wellington Rd, Clayton, Vic 3800 (Australia); Minond, Dmitriy [Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port Saint Lucie, FL 34987 (United States); Smith, A. Ian [Department of Biochemistry and Molecular Biology, Building 77, Monash University, Wellington Rd, Clayton, Vic 3800 (Australia)

    2014-04-04

    Highlights: • A soluble full-length form of Neprilysin exists in media of endothelial cells. • Exosomal release is the key mechanism for the production of soluble Neprilysin. • Inhibition of ADAM-17 by specific inhibitors reduce Neprilysin release. • Exosome mediated release of Neprilysin is dependent on ADAM-17 activity. - Abstract: A non-membrane bound form of Neprilysin (NEP) with catalytic activity has the potential to cleave substrates throughout the circulation, thus leading to systemic effects of NEP. We used the endothelial cell line Ea.hy926 to identify the possible role of exosomes and A Disintegrin and Metalloprotease 17 (ADAM-17) in the production of non-membrane bound NEP. Using a bradykinin based quenched fluorescent substrate (40 μM) assay, we determined the activity of recombinant human NEP (rhNEP; 12 ng), and NEP in the media of endothelial cells (10% v/v; after 24 h incubation with cells) to be 9.35 ± 0.70 and 6.54 ± 0.41 μmols of substrate cleaved over 3 h, respectively. The presence of NEP in the media was also confirmed by Western blotting. At present there are no commercially available inhibitors specific for ADAM-17. We therefore synthesised two inhibitors TPI2155-14 and TPI2155-17, specific for ADAM-17 with IC{sub 50} values of 5.36 and 4.32 μM, respectively. Treatment of cells with TPI2155-14 (15 μM) and TPI2155-17 (4.3 μM) resulted in a significant decrease in NEP activity in media (62.37 ± 1.43 and 38.30 ± 4.70, respectively as a % of control; P < 0.0001), implicating a possible role for ADAM-17 in NEP release. However, centrifuging media (100,000g for 1 h at 4 °C) removed all NEP activity from the supernatant indicating the likely role of exosomes in the release of NEP. Our data therefore indicated for the first time that NEP is released from endothelial cells via exosomes, and that this process is dependent on ADAM-17.

  14. Biological significance of soluble IL-2 receptor

    Directory of Open Access Journals (Sweden)

    Calogero Caruso

    1993-01-01

    Full Text Available A NUMBER of receptors for growth factors and differentiation antigens have been found to be secreted or released by cells. Following mononuclear cell (MNC activation and interleukin-2 receptor (IL-2R expression, a soluble form of the Alpha;-chain of IL-2R (sIL-2R is released. The sIL-2R has been shown to be present in the culture supernatants of activated MNCs as well as in normal sera and, in higher amounts, in sera from subjects affected by several diseases including neoplastic, infectious and autoimmune ones, and in sera from transplanted patients suffering allograft rejection. The blood sIL-2R levels depend on the number of producing cells and the number of molecules per cell, so that sIL-2R blood values may represent an index of the number and the functional state of producing cells, both normal and neoplastic. Thus, monitoring of the immune system, mostly T-cells and haematological malignancies might be targets for the measurement of sIL-2R. Since many conditions may influence sIL-2R production, little diagnostic use may result from these measurements. However, since blood sIL-2R levels may correlate with disease progression and/or response to therapy, their measurement may be a useful index of activity and extent of disease. The precise biological role of the soluble form of the IL-2R is still a matter of debate. However, we know that increased sIL-2R levels may be observed in association with several immunological abnormalities and that sIL-2R is able to bind IL-2. It is conceivable then that in these conditions the excess sIL-2R released in vivo by activated lymphoid cells or by neoplastic cells may somehow regulate IL-2-dependent processes. On the other hand, it cannot exclude that sIL-2R is a by-product without biological significance. Finally, it is puzzling that in many conditions in which an increase of blood sIL-2R values has been observed, MNCs display a decreased in vitro capacity to produce sIL-2R. These seemingly contrasting

  15. THE EFFECT OF THE PROTEIN SOLUBILITY OF FISH MEAL AND ...

    African Journals Online (AJOL)

    Whitelaw & Preston (1963) procured two fish meals from different sources. The solubility of these products in M.NaCIsolution was 6,2 and 77;l %.When fed to early weaned calves the insoluble products resulted in a significantly higher nitrogen retention while the 'soluble' one gave rise to higher ammonia levels in the rumen.

  16. A Lab Experiment to Introduce Gas/Liquid Solubility

    Science.gov (United States)

    Fonsecaa, I. M. A.; Almeida, J. P. B.; Fachada, H. C.

    2008-01-01

    A simplified version of a volumetric apparatus for gas/liquid solubility measurements is proposed. The procedure familiarizes undergraduate students with the experimental study of the solubility of a gas in a liquid and contributes to the understanding of this important phase equilibrium concept. The experimental results report the determination…

  17. Solubilities of sub- and supercritical carbon dioxide in polyester resins

    NARCIS (Netherlands)

    Nalawade, SP; Picchioni, F; Janssen, LPBM; Patil, VE; Keurentjes, JTF; Staudt, R; Nalawade, Sameer P.; Patil, Vishal E.; Keurentjes, Jos T.F.

    In supercritical carbon dioxide (CO2) assisted polymer processes the solubility of CO2 in a polymer plays a vital role. The higher the amount of CO2 dissolved in a polymer the higher is the viscosity reduction of the polymer. Solubilities Of CO2 in polyester resins based on propoxylated bisphenol

  18. Identification of potent, soluble, and orally active TRPV1 antagonists.

    Science.gov (United States)

    Ratcliffe, Paul; Maclean, John; Abernethy, Lynn; Clarkson, Tom; Dempster, Maureen; Easson, Anna-Marie; Edwards, Darren; Everett, Katy; Feilden, Helen; Littlewood, Peter; McArthur, Duncan; McGregor, Deborah; McLuskey, Hazel; Nimz, Olaf; Nisbet, Lesley-Anne; Palin, Ronnie; Tracey, Heather; Walker, Glenn

    2011-04-15

    Optimization of a water soluble, moderately potent lead series of isoxazole-3-carboxamides was conducted, affording a compound with the requisite balance of potency, solubility and physicochemical properties for in vivo use. Compound 8e was demonstrated to be efficacious in a rat model of inflammatory pain, following oral administration. Copyright © 2011. Published by Elsevier Ltd.

  19. Soluble Nutrient Production During Fermentation of Three Melon ...

    African Journals Online (AJOL)

    The amount of soluble nutrient production (soluble sugars and free amino acids) in three varieties of melon seeds, Citrullus colocynthis (A), Cucumis melo (B) and Cucumeropsis mannii (C) during fermentation in Musa spp (M), Thaumatococcus danielli (D) and Carica papaya (P) leaves were investigated. Proximate ...

  20. Solubility advantage of amorphous pharmaceuticals: I. A thermodynamic analysis.

    Science.gov (United States)

    Murdande, Sharad B; Pikal, Michael J; Shanker, Ravi M; Bogner, Robin H

    2010-03-01

    In recent years there has been growing interest in advancing amorphous pharmaceuticals as an approach for achieving adequate solubility. Due to difficulties in the experimental measurement of solubility, a reliable estimate of the solubility enhancement ratio of an amorphous form of a drug relative to its crystalline counterpart would be highly useful. We have developed a rigorous thermodynamic approach to estimate enhancement in solubility that can be achieved by conversion of a crystalline form to the amorphous form. We rigorously treat the three factors that contribute to differences in solubility between amorphous and crystalline forms. First, we calculate the free energy difference between amorphous and crystalline forms from thermal properties measured by modulated differential scanning calorimetry (MDSC). Secondly, since an amorphous solute can absorb significant amounts of water, which reduces its activity and solubility, a correction is made using water sorption isotherm data and the Gibbs-Duhem equation. Next, a correction is made for differences in the degree of ionization due to differences in solubilities of the two forms. Utilizing this approach the theoretically estimated solubility enhancement ratio of 7.0 for indomethacin (amorphous/gamma-crystal) was found to be in close agreement with the experimentally determined ratio of 4.9. 2009 Wiley-Liss, Inc. and the American Pharmacists Association

  1. Using MD Simulations To Calculate How Solvents Modulate Solubility.

    Science.gov (United States)

    Liu, Shuai; Cao, Shannon; Hoang, Kevin; Young, Kayla L; Paluch, Andrew S; Mobley, David L

    2016-04-12

    Here, our interest is in predicting solubility in general, and we focus particularly on predicting how the solubility of particular solutes is modulated by the solvent environment. Solubility in general is extremely important, both for theoretical reasons - it provides an important probe of the balance between solute-solute and solute-solvent interactions - and for more practical reasons, such as how to control the solubility of a given solute via modulation of its environment, as in process chemistry and separations. Here, we study how the change of solvent affects the solubility of a given compound. That is, we calculate relative solubilities. We use MD simulations to calculate relative solubility and compare our calculated values with experiment as well as with results from several other methods, SMD and UNIFAC, the latter of which is commonly used in chemical engineering design. We find that straightforward solubility calculations based on molecular simulations using a general small-molecule force field outperform SMD and UNIFAC both in terms of accuracy and coverage of the relevant chemical space.

  2. Solubility of non-polar gases in electrolyte solutions

    Science.gov (United States)

    Walker, R. L., Jr.

    1970-01-01

    Solubility theory describes the effects of both concentration and temperature on solute activity coefficients. It predicts the salting-out effect and the decrease in solubility of non-polar gases with increased electrolyte concentration, and can be used to calculate heats of solution, entropies, and partial molal volumes of dissolved gases

  3. Facilitating protein solubility by use of peptide extensions

    Science.gov (United States)

    Freimuth, Paul I; Zhang, Yian-Biao; Howitt, Jason

    2013-09-17

    Expression vectors for expression of a protein or polypeptide of interest as a fusion product composed of the protein or polypeptide of interest fused at one terminus to a solubility enhancing peptide extension are provided. Sequences encoding the peptide extensions are provided. The invention further comprises antibodies which bind specifically to one or more of the solubility enhancing peptide extensions.

  4. Nitrogen solubility index and amino acid profile of extruded African ...

    African Journals Online (AJOL)

    Nitrogen solubility index decreased with extrusion cooking by more than 50% in all the point blends. Soybean lowered nitrogen solubility index while African breadfruit increased it from 17 to 22% in the raw and 7.25 to 9% in the extruded samples. The model developed in the study accounted for 60.21% of the total variation ...

  5. Measurement and Accurate Interpretation of the Solubility of Pharmaceutical Salts.

    Science.gov (United States)

    He, Yan; Ho, Chris; Yang, Donglai; Chen, Jeane; Orton, Edward

    2017-05-01

    Salt formation is one of the primary approaches to improve the developability of ionizable poorly water-soluble compounds. Solubility determination of the salt candidates in aqueous media or biorelevant fluids is a critical step in salt screening. Salt solubility measurements can be complicated due to dynamic changes in both solution and solid phases. Because of the early implementation of salt screening in research, solubility measurements often are performed using minimal amount of material. Some salts have transient high solubility on dissolution. Recognition of these transients can be critical in developing these salts into drug products. This minireview focuses on challenges in salt solubility measurements due to the changes in solution caused by self-buffering effects of dissolved species and the changes in solid phase due to solid-state phase transformations. Solubility measurements and their accurate interpretation are assessed in the context of dissolution monitoring and solid-phase analysis technologies. A harmonized method for reporting salt solubility measurements is recommended to reduce errors and to align with the U.S. Pharmacopeial policy and Food and Drug Administration recommendations for drug products containing pharmaceutical salts. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  6. 21 CFR 520.88d - Amoxicillin trihydrate soluble powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Amoxicillin trihydrate soluble powder. 520.88d Section 520.88d Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... trihydrate soluble powder. (a) Specifications. Each gram contains amoxicillin trihydrate equivalent to 115.4...

  7. 21 CFR 520.44 - Acetazolamide sodium soluble powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acetazolamide sodium soluble powder. 520.44 Section 520.44 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Acetazolamide sodium soluble powder. (a) Specifications. The drug is in a powder form containing acetazolamide...

  8. 40 CFR Table 3 to Subpart Ggg of... - Soluble HAP

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Soluble HAP 3 Table 3 to Subpart GGG of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... for Pharmaceuticals Production Pt. 63, Subpt. GGG, Table 3 Table 3 to Subpart GGG of Part 63—Soluble...

  9. 21 CFR 520.90e - Ampicillin trihydrate soluble powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ampicillin trihydrate soluble powder. 520.90e Section 520.90e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... trihydrate soluble powder. (a) Specifications. Each gram contains ampicillin trihydrate equivalent to 88.2...

  10. Bioconcentration of Water Soluble Fraction (WSF) of crude oil in ...

    African Journals Online (AJOL)

    Bioconcentration of water soluble fraction of Australian crude oil in 50 fingerlings of Oreochromis niloticus was conducted under laboratory conditions for 28 days. An initial acute toxicity test was carried out using different concentrations (25ml/L, 50ml/L, 75ml/L, 100ml/L and a control) of the water soluble fraction (WSF) of ...

  11. Vertically averaged approaches for CO 2 migration with solubility trapping

    KAUST Repository

    Gasda, S. E.

    2011-05-20

    The long-term storage security of injected carbon dioxide (CO2) is an essential component of geological carbon sequestration operations. In the postinjection phase, the mobile CO2 plume migrates in large part because of buoyancy forces, following the natural topography of the geological formation. The primary trapping mechanisms are capillary and solubility trapping, which evolve over hundreds to thousands of years and can immobilize a significant portion of the mobile CO2 plume. However, both the migration and trapping processes are inherently complex, spanning multiple spatial and temporal scales. Using an appropriate model that can capture both large- and small-scale effects is essential for understanding the role of these processes on the long-term storage security of CO2 sequestration operations. Traditional numerical models quickly become prohibitively expensive for the type of large-scale, long-term modeling that is necessary for characterizing the migration and immobilization of CO2 during the postinjection period. We present an alternative modeling option that combines vertically integrated governing equations with an upscaled representation of the dissolution-convection process. With this approach, we demonstrate the effect of different modeling choices for typical large-scale geological systems and show that practical calculations can be performed at the temporal and spatial scales of interest. Copyright 2011 by the American Geophysical Union.

  12. Hansen solubility parameter analysis on the dispersion of zirconia nanocrystals.

    Science.gov (United States)

    Wang, Sho-Hsun; Liu, Jia-Hong; Pai, Chin-Tung; Chen, Chien-Wei; Chung, Pao-Tang; Chiang, Anthony Shiaw-Tseh; Chang, Shinn-Jen

    2013-10-01

    Nanoparticle dispersible in a broad range of solvents is desirable when preparing an organic/inorganic nanocomposite. In this report, the dispersion behavior of carboxylate-grafted zirconia nanoparticle in 25 solvents covering a wide range of polarity was analyzed based on their Hansen solubility parameters (HSP). Particles grafted with alkyl-chain longer than four carbons could only be dispersed in non-polar solvents, while that grafted with acetic acid was dispersible in polar ones. However, particle modified with methacrylic acid (MA) was compatible with both types of solvents, which was rather unexpected. Further NMR analysis showed that the carboxylate-grafted samples contained a trace amount of triethanolamine (TEA) due to the particular ZrO2 synthesis process employed. The combination of the hydrophilic TEA ligand with the short hydrophobic tail of methacrylate broadened the range of compatible solvents from benzene to methanol. Such an extended solvent compatibility was observed previously only for nanoparticles covered with large polymer surfactants having both hydrophilic and hydrophobic groups. Achieving this with two small molecules having separate functional groups is crucial when one needs to maximize the inorganic content in a composite. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Winning Combinations

    DEFF Research Database (Denmark)

    Criscuolo, Paola; Laursen, Keld; Reichstein, Toke

    2017-01-01

    Searching for the most rewarding sources of innovative ideas remains a key challenge in management of technological innovation. Yet, little is known about which combinations of internal and external knowledge sources are triggers for innovation. Extending theories about searching for innovation, ...

  14. Low Levels of Serum Soluble Receptors for Advanced Glycation End Products, Biomarkers for Disease State: Myth or Reality

    OpenAIRE

    Prasad, Kailash

    2014-01-01

    Advanced glycation end products (AGEs) interact with the receptor for AGEs (RAGE) on the membrane and induce deleterious effects via activation of nuclear factor kappa-B, and increased oxidative stress and inflammatory mediators. AGEs also combine with circulating soluble receptors (endogenous secretory RAGE [esRAGE] and soluble receptor for RAGE [sRAGE]) and sequester RAGE ligands and act as a cytoprotective agent. esRAGE is secreted from the cells and is a spliced variant of RAGE. The sRAGE...

  15. Solid Phospholipid Dispersions for Oral Delivery of Poorly Soluble Drugs

    DEFF Research Database (Denmark)

    Fong, Sophia Yui Kau; Martins, Susana A. M.; Brandl, Martin

    2016-01-01

    Celecoxib (CXB) is a Biopharmaceutical Classification System class II drug in which its oral bioavailability is limited by poor aqueous solubility. Although a range of formulations aiming to increase the solubility of CXB have been developed, it is not completely understood, whether (1) an increase...... in CXB solubility leads to a subsequent increase in permeability across intestinal barrier and (2) the presence of bile salts affects the solubility and permeability behavior of CXB formulations. By formulating CXB solid phospholipid (PL) dispersions with various PL-to-drug ratios using freeze drying......, the present study illustrated that the enhancement of CXB solubility was not proportionally translated into enhanced permeability; both parameters were highly dependent on the PL-to-drug ratios as well as the dispersion media (i.e., the presence of 3-mM sodium taurocholate). This study highlights...

  16. Sparingly soluble pesticide dissolved in ionic liquid aqueous.

    Science.gov (United States)

    Fan, Tengfei; Wu, Xuemin; Peng, Qingrong

    2014-10-02

    Ionic liquids may be considered as "environment-friendly solvents" for sparingly soluble pesticides. In this study, a series of aqueous ionic liquids (ILs) with different cations and different anions was used as environment-friendly alternative to harmful organic solvents sparingly dissolved in soluble pesticides (metolachlor, acetochlor, clethodim, thiamethoxam, and prochloraz). The aggregation behavior of aqueous ILs was investigated through surface tension measurement. Minimum area per IL molecule (Amin) values from the surface tension measurement showed that alkyl chain length and the halide anions strongly affect the aggregation behavior of ILs and the solubilization of pesticides. The solubility of metolachlor, acetochlor, clethodim, thiamethoxam, nitenpyram, and prochloraz in aqueous ILs increased. More importantly, the solubility of prochloraz in [C10mim][I] became 5771-fold higher than that in pure water. The substantially enhanced solubility of the above pesticides proved that aqueous ILs are promising environment-friendly solvents for pesticides that are commercially processed in emulsifiable concentrate (EC) formulation.

  17. New Biopolymer Nanoparticles Improve the Solubility of Lipophilic Megestrol Acetate

    Directory of Open Access Journals (Sweden)

    Malwina Lachowicz

    2016-02-01

    Full Text Available As many substances are poorly soluble in water and thus possess decreased bioavailability, creating orally administered forms of these substances is a challenge. The objective of this study was to determine whether the solubility of megestrol acetate, a Biopharmaceutical Classification System (BCS class II drug, can be improved by using a newly-synthesized surfactant (Rofam 70: a rapeseed methyl ester ethoxylate and compare it with two references surfactants (Tween 80, Pluronic F68 at three different pH values. Spectrophotometry was used to compare the solubility profiles in the presence of three tested surfactants at pH 5.0, 7.4 and 9.0. Rapeseed methyl ester ethoxylate was found to improve the solubility of the BCS Class II drug and increase its bioavailability; It increased drug solubility more effectively than Pluronic F68. Its cytotoxicity results indicate its possible value as a surfactant in Medicine and Pharmacy.

  18. Solubility of multi-component biodiesel fuel systems.

    Science.gov (United States)

    Makareviciene, Violeta; Sendzikiene, Egle; Janulis, Prutenis

    2005-03-01

    Solubility of biodiesel fuel components in fossil diesel fuel-methanol-rapeseed oil methyl ester, fossil diesel fuel-ethanol-rapeseed oil methyl ester and fossil diesel fuel-ethanol-rapeseed oil ethyl ester systems was investigated. The solubility of components in the fossil diesel fuel-ethanol-rapeseed oil methyl ester system at 20 degrees C was substantially higher than in the fossil diesel fuel-methanol-rapeseed oil methyl ester system. The solubility of components in the fossil diesel fuel-ethanol-rapeseed oil ethyl ester system was slightly lower than in the fossil diesel fuel-ethanol-rapeseed oil methyl ester mixture. The moisture content of ethanol had a great influence on mixture solubility. With decrease of temperature, the solubility of components in the fossil diesel fuel-ethanol-rapeseed oil methyl ester system decreased.

  19. Molecular model for solubility of gases in flexible polymers

    DEFF Research Database (Denmark)

    Neergaard, Jesper; Hassager, Ole; Szabo, Peter

    1999-01-01

    We propose a model for a priori prediction of the solubility of gases in flexible polymers. The model is based on the concept of ideal solubility of gases in liquids. According to this concept, the mole fraction of gases in liquids is given by Raoult's law with the total pressure and the vapor...... the length of the rods with the molecular weight corresponding to a Kuhn step. The model provides a tool for crude estimation of the gas solubility on the basis of only the monomer unit of the polymer and properties of the gas. A comparison with the solubility data for several gases in poly......(dimethylsiloxane) reveals agreement between the data and the model predictions within a factor of 7 and that better model results are achieved for temperatures below the critical temperature of the gas. The model predicts a decreasing solubility with increasing temperature (because of the increasing vapor pressure...

  20. Fast Measurement of Soluble Solid Content in Mango Based on Visible and Infrared Spectroscopy Technique

    Science.gov (United States)

    Yu, Jiajia; He, Yong

    Mango is a kind of popular tropical fruit, and the soluble solid content is an important in this study visible and short-wave near-infrared spectroscopy (VIS/SWNIR) technique was applied. For sake of investigating the feasibility of using VIS/SWNIR spectroscopy to measure the soluble solid content in mango, and validating the performance of selected sensitive bands, for the calibration set was formed by 135 mango samples, while the remaining 45 mango samples for the prediction set. The combination of partial least squares and backpropagation artificial neural networks (PLS-BP) was used to calculate the prediction model based on raw spectrum data. Based on PLS-BP, the determination coefficient for prediction (Rp) was 0.757 and root mean square and the process is simple and easy to operate. Compared with the Partial least squares (PLS) result, the performance of PLS-BP is better.

  1. Nanocrystals for enhancement of oral bioavailability of poorly water-soluble drugs

    Directory of Open Access Journals (Sweden)

    Varaporn Buraphacheep Junyaprasert

    2015-02-01

    Full Text Available Nanocrystals, a carrier-free colloidal delivery system in nano-sized range, is an interesting approach for poorly soluble drugs. Nanocrystals provide special features including enhancement of saturation solubility, dissolution velocity and adhesiveness to surface/cell membranes. Several strategies are applied for nanocrystals production including precipitation, milling, high pressure homogenization and combination methods such as NanoEdge™, SmartCrystal and Precipitation-lyophilization-homogenization (PLH technology. For oral administration, many publications reported useful advantages of nanocrystals to improve in vivo performances i.e. pharmacokinetics, pharmacodynamics, safety and targeted delivery which were discussed in this review. Additionally, transformation of nanocrystals to final formulations and future trends of nanocrystals were also described.

  2. Screening of genetic parameters for soluble protein expression in Escherichia coli

    DEFF Research Database (Denmark)

    Vernet, Erik; Kotzsch, Alexander; Voldborg, Bjørn

    2011-01-01

    Soluble expression of proteins in a relevant form for functional and structural investigations still often remains a challenge. Although many biochemical factors are known to affect solubility, a thorough investigation of yield-limiting factors is normally not feasible in high-throughput efforts....... Here we present a screening strategy for expression of biomedically relevant proteins in Escherichia coli using a panel of six different genetic variations. These include engineered strains for rare codon supplementation, increased disulfide bond formation in the cytoplasm and novel vectors...... for secretion to the periplasm or culture medium. Combining these variants with expression construct truncations design, we report on parallel cloning and expression of more than 300 constructs representing 24 selected proteins; including full-length variants of human growth factors, interleukins and growth...

  3. Changes in Apparent Molar Water Volume and DKP Solubility Yield Insights on the Hofmeister Effect

    Science.gov (United States)

    Payumo, Alexander Y.; Huijon, R. Michael; Mansfield, Deauna D.; Belk, Laurel M.; Bui, Annie K.; Knight, Anne E.; Eggers, Daryl K.

    2011-01-01

    This study examines the properties of a 4 × 2 matrix of aqueous cations and anions at concentrations up to 8.0 M. The apparent molar water volume, as calculated by subtracting the mass and volume of the ions from the corresponding solution density, was found to exceed the molar volume of ice in many concentrated electrolyte solutions, underscoring the non-ideal behavior of these systems. The solvent properties of water were also analyzed by measuring the solubility of diketopiperazine (DKP) in 2.000 M salt solutions prepared from the same ion combinations. Solution rankings for DKP solubility were found to parallel the Hofmeister series for both cations and anions, whereas molar water volume concurred with the cation series only. The results are discussed within the framework of a desolvation energy model that attributes solute-specific changes in equilibria to solute-dependent changes in the free energy of bulk water. PMID:22029390

  4. Measurement of Soluble Biomarkers by Flow Cytometry.

    Science.gov (United States)

    Antal-Szalmás, Péter; Nagy, Béla; Debreceni, Ildikó Beke; Kappelmayer, János

    2013-01-01

    Microparticle based flow cytometric assays for determination of the level of soluble biomarkers are widely used in several research applications and in some diagnostic setups. The major advantages of these multiplex systems are that they can measure a large number of analytes (up to 500) at the same time reducing assay time, costs and sample volume. Most of these assays are based on antigen-antibody interactions and work as traditional immunoassays, but nucleic acid alterations - by using special hybridization probes -, enzyme- substrate or receptor-ligand interactions can be also studied with them. The applied beads are nowadays provided by the manufacturers, but cheaper biological microbeads can be prepared by any user. One part of the systems can be used on any research or clinical cytometers, but some companies provide dedicated analyzers for their multiplex bead arrays. Due to the high standardization of the bead production and the preparation of the assay components the analytical properties of these assays are quite reliable with a wide range of available applications. Cytokines, intracellular fusion proteins, activated/phosphorylated components of different signaling pathways, transcription factors and nuclear receptors can be identified and quantitated. The assays may serve the diagnostics of autoimmune disorders, different viral and bacterial infections, as well as genetic alterations such as single nucleotide polymorphisms, small deletions/insertions or even nucleotide triplet expansions can be also identified. The most important principles, technical details and applications of these systems are discussed in this short review.

  5. Electron transfer control in soluble methane monooxygenase.

    Science.gov (United States)

    Wang, Weixue; Iacob, Roxana E; Luoh, Rebecca P; Engen, John R; Lippard, Stephen J

    2014-07-09

    The hydroxylation or epoxidation of hydrocarbons by bacterial multicomponent monooxygenases (BMMs) requires the interplay of three or four protein components. How component protein interactions control catalysis, however, is not well understood. In particular, the binding sites of the reductase components on the surface of their cognate hydroxylases and the role(s) that the regulatory proteins play during intermolecular electron transfer leading to the hydroxylase reduction have been enigmatic. Here we determine the reductase binding site on the hydroxylase of a BMM enzyme, soluble methane monooxygenase (sMMO) from Methylococcus capsulatus (Bath). We present evidence that the ferredoxin domain of the reductase binds to the canyon region of the hydroxylase, previously determined to be the regulatory protein binding site as well. The latter thus inhibits reductase binding to the hydroxylase and, consequently, intermolecular electron transfer from the reductase to the hydroxylase diiron active site. The binding competition between the regulatory protein and the reductase may serve as a control mechanism for regulating electron transfer, and other BMM enzymes are likely to adopt the same mechanism.

  6. Impact of Dendrimers on Solubility of Hydrophobic Drug Molecules

    Directory of Open Access Journals (Sweden)

    Sonam Choudhary

    2017-05-01

    Full Text Available Adequate aqueous solubility has been one of the desired properties while selecting drug molecules and other bio-actives for product development. Often solubility of a drug determines its pharmaceutical and therapeutic performance. Majority of newly synthesized drug molecules fail or are rejected during the early phases of drug discovery and development due to their limited solubility. Sufficient permeability, aqueous solubility and physicochemical stability of the drug are important for achieving adequate bioavailability and therapeutic outcome. A number of different approaches including co-solvency, micellar solubilization, micronization, pH adjustment, chemical modification, and solid dispersion have been explored toward improving the solubility of various poorly aqueous-soluble drugs. Dendrimers, a new class of polymers, possess great potential for drug solubility improvement, by virtue of their unique properties. These hyper-branched, mono-dispersed molecules have the distinct ability to bind the drug molecules on periphery as well as to encapsulate these molecules within the dendritic structure. There are numerous reported studies which have successfully used dendrimers to enhance the solubilization of poorly soluble drugs. These promising outcomes have encouraged the researchers to design, synthesize, and evaluate various dendritic polymers for their use in drug delivery and product development. This review will discuss the aspects and role of dendrimers in the solubility enhancement of poorly soluble drugs. The review will also highlight the important and relevant properties of dendrimers which contribute toward drug solubilization. Finally, hydrophobic drugs which have been explored for dendrimer assisted solubilization, and the current marketing status of dendrimers will be discussed.

  7. Impact of Dendrimers on Solubility of Hydrophobic Drug Molecules

    Science.gov (United States)

    Choudhary, Sonam; Gupta, Lokesh; Rani, Sarita; Dave, Kaushalkumar; Gupta, Umesh

    2017-01-01

    Adequate aqueous solubility has been one of the desired properties while selecting drug molecules and other bio-actives for product development. Often solubility of a drug determines its pharmaceutical and therapeutic performance. Majority of newly synthesized drug molecules fail or are rejected during the early phases of drug discovery and development due to their limited solubility. Sufficient permeability, aqueous solubility and physicochemical stability of the drug are important for achieving adequate bioavailability and therapeutic outcome. A number of different approaches including co-solvency, micellar solubilization, micronization, pH adjustment, chemical modification, and solid dispersion have been explored toward improving the solubility of various poorly aqueous-soluble drugs. Dendrimers, a new class of polymers, possess great potential for drug solubility improvement, by virtue of their unique properties. These hyper-branched, mono-dispersed molecules have the distinct ability to bind the drug molecules on periphery as well as to encapsulate these molecules within the dendritic structure. There are numerous reported studies which have successfully used dendrimers to enhance the solubilization of poorly soluble drugs. These promising outcomes have encouraged the researchers to design, synthesize, and evaluate various dendritic polymers for their use in drug delivery and product development. This review will discuss the aspects and role of dendrimers in the solubility enhancement of poorly soluble drugs. The review will also highlight the important and relevant properties of dendrimers which contribute toward drug solubilization. Finally, hydrophobic drugs which have been explored for dendrimer assisted solubilization, and the current marketing status of dendrimers will be discussed. PMID:28559844

  8. Effect of composition of simulated intestinal media on the solubility of poorly soluble compounds investigated by design of experiments

    DEFF Research Database (Denmark)

    Madsen, Cecilie Maria; Feng, Kung-I; Leithead, Andrew

    2018-01-01

    , and different pH, buffer capacities and osmolarities. On a small scale semi-robotic system, the solubility of 6 compounds (aprepitant, carvedilol, felodipine, fenofibrate, probucol, and zafirlukast) was determined in the 24 SIF. Compound specific models, describing key factors influencing the solubility of each...

  9. Characterization of soluble protein BCP 11/24 from bovine corneal epithelium, different from the principal soluble protein BCP 54

    NARCIS (Netherlands)

    Bakker, C.; Pasmans, S.; Verhagen, C.; van Haren, M.; van der Gaag, R.; Hoekzema, R.

    1992-01-01

    The water-soluble fraction of bovine corneal epithelium was analysed by polyacrylamide gel electrophoresis in the presence of SDS (SDS-PAGE). Next to the principal soluble protein BCP 54, which has recently been identified as a corneal aldehyde dehydrogenase (ALDH), another abundant protein was

  10. Solubilities of selected organic electronic materials in pressurized hot water and estimations of aqueous solubilities at 298.15 K.

    Science.gov (United States)

    Karásek, Pavel; Hohnová, Barbora; Planeta, Josef; Št'avíková, Lenka; Roth, Michal

    2013-02-01

    Increasing production and disposal of organic light-emitting diode (OLED) displays for smartphones and tablets may have impact on the environment depending on the aqueous solubility of the pertinent chemicals. Here, aqueous solubilities are presented for several compounds, mostly aromatic amines, used as hole transport materials in the OLED displays. Solute selection includes 1,4-bis(diphenylamino)benzene, tetra-N-phenylbenzidine, 4,4'-bis(N-carbazolyl)-1,1'-biphenyl, 1,3,5-tris(diphenylamino)benzene, and 9,10-bis(phenylethynyl)anthracene. The solubilities are those in pressurized hot water (PHW), i.e., measured at elevated temperature (up to 260 °C) and pressure. The semi-quantitative estimates of room-temperature solubilities of the solutes have been obtained from extrapolations of the solubilities in PHW. For the compounds studied, the estimated aqueous solubilities at room temperature do not exceed 2×10(-11) g of the solute per 1 kg of water. Aqueous solubilities of triphenylamine have also been measured and used to upgrade a recent group-contribution model of aqueous solubilities of organic nonelectrolytes with the parameters for the nitrogen atom in aromatic amines. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Solubility prediction, solvate and cocrystal screening as tools for rational crystal engineering.

    Science.gov (United States)

    Loschen, Christoph; Klamt, Andreas

    2015-06-01

    The fact that novel drug candidates are becoming increasingly insoluble is a major problem of current drug development. Computational tools may address this issue by screening for suitable solvents or by identifying potential novel cocrystal formers that increase bioavailability. In contrast to other more specialized methods, the fluid phase thermodynamics approach COSMO-RS (conductor-like screening model for real solvents) allows for a comprehensive treatment of drug solubility, solvate and cocrystal formation and many other thermodynamics properties in liquids. This article gives an overview of recent COSMO-RS developments that are of interest for drug development and contains several new application examples for solubility prediction and solvate/cocrystal screening. For all property predictions COSMO-RS has been used. The basic concept of COSMO-RS consists of using the screening charge density as computed from first principles calculations in combination with fast statistical thermodynamics to compute the chemical potential of a compound in solution. The fast and accurate assessment of drug solubility and the identification of suitable solvents, solvate or cocrystal formers is nowadays possible and may be used to complement modern drug development. Efficiency is increased by avoiding costly quantum-chemical computations using a database of previously computed molecular fragments. COSMO-RS theory can be applied to a range of physico-chemical properties, which are of interest in rational crystal engineering. Most notably, in combination with experimental reference data, accurate quantitative solubility predictions in any solvent or solvent mixture are possible. Additionally, COSMO-RS can be extended to the prediction of cocrystal formation, which results in considerable predictive accuracy concerning coformer screening. In a recent variant costly quantum chemical calculations are avoided resulting in a significant speed-up and ease-of-use. © 2015 Royal

  12. Water-Soluble 2-Hydroxyisophthalamides for Sensitization of Lanthanide Luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Samuel, Amanda P. S.; Moore, Evan G.; Melchior, Marco; Xu, Jide; Raymond, Kenneth N.

    2008-02-20

    A series of octadentate ligands featuring the 2-hydroxyisophthalamide (IAM) antenna chromophore (to sensitize Tb(III) and Eu(III) luminescence) has been prepared and characterized. The length of the alkyl amine scaffold that links the four IAM moieties has been varied in order to investigate the effect of the ligand backbone on the stability and photophysical properties of the Ln(III) complexes. The amine backbones utilized in this study are N,N,N{prime},N{prime}-tetrakis-(2-aminoethyl)-ethane-1,2-diamine [H(2,2)-], N,N,N{prime},N{prime}-tetrakis-(2-aminoethyl)-propane-1,3-diamine [H(3,2)-] and N,N,N{prime},N{prime}-tetrakis-(2-aminoethyl)-butane-1,4-diamine [H(4,2)-]. These ligands also incorporate methoxyethylene [MOE] groups on each of the IAM chromophores to increase their water solubility. The aqueous ligand protonation constants and Tb(III) and Eu(III) formation constants were determined from solution thermodynamic studies. The resulting values indicate that at physiological pH, the Eu(III) and Tb(III) complexes of H(2,2)-IAM-MOE and H(4,2)-IAM-MOE are sufficiently stable to prevent dissociation at nanomolar concentrations. The photophysical measurements for the Tb(III) complexes gave overall quantum yield values of 0.56, 0.39, and 0.52 respectively for the complexes with H(2,2)-IAM-MOE, H(3,2)-IAM-MOE and H(4,2)-IAM-MOE, while the corresponding Eu(III) complexes displayed significantly weaker luminescence, with quantum yield values of 0.0014, 0.0015, and 0.0058, respectively. Analysis of the steady state Eu(III) emission spectra provides insight into the solution symmetries of the complexes. The combined solubility, stability and photophysical performance of the Tb(III) complexes in particular make them well suited to serve as the luminescent reporter group in high sensitivity time-resolved fluoroimmunoassays.

  13. Solubility parameter of drugs for predicting the solubility profile type within a wide polarity range in solvent mixtures.

    Science.gov (United States)

    Peña, M A; Reíllo, A; Escalera, B; Bustamante, P

    2006-09-14

    The solubility enhancement produced by two binary mixtures with a common cosolvent (ethanol-water and ethyl acetate-ethanol) was studied against the solubility parameter of the mixtures (delta1) to characterize different types of solubility profiles. Benzocaine, salicylic acid and acetanilide show a single peak in the least polar mixture (ethanol-ethyl acetate) at delta1=22.59, 21.70 and 20.91 MPa1/2, respectively. Phenacetin displays two solubility maxima, at delta1=25.71 (ethanol-water) and at delta1=23.30 (ethyl acetate-ethanol). Acetanilide shows an inflexion point in ethanol-water instead of a peak, and the sign of the slope does not vary when changing the cosolvent. The solubility profiles were compared to those obtained in dioxane-water, having a solubility parameter range similar to that covered with the common cosolvent system. All the drugs reach a maximum at about 90% dioxane (delta1=23 MPa1/2). A modification of the extended Hildebrand method is applicable for curves with a single maximum whereas a model including the Hildebrand solubility parameter delta1 and the acidic partial solubility parameter delta1a is required to calculate more complex solubility profiles (with inflexion point or two maxima). A single equation was able to fit the solubility curves of all drugs in the common cosolvent system. The polarity of the drug is related to the shape of the solubility profile against the solubility parameter delta1 of the solvent mixtures. The drugs with solubility parameters below 24 MPa1/2 display a single peak in ethanol-ethyl acetate. The drugs with delta2 values above 25 MPa1/2 show two maxima, one in each solvent mixture (ethanol-water and ethanol-ethyl acetate). The position of the maximum in ethanol-ethyl acetate shifts to larger polarity values (higher delta1 values) as the solubility parameter of the drug delta2 increases.

  14. Ion Association versus Ion Interaction Models in Examining Electrolyte Solutions: Application to Calcium Hydroxide Solubility Equilibrium

    Science.gov (United States)

    Menéndez, M. Isabel; Borge, Javier

    2014-01-01

    The heterogeneous equilibrium of the solubility of calcium hydroxide in water is used to predict both its solubility product from solubility and solubility values from solubility product when inert salts, in any concentration, are present. Accepting the necessity of including activity coefficients to treat the saturated solution of calcium…

  15. Illustrating the Concept of Sparingly Soluble Salts Using Various Copper Compounds: A Classroom Demonstration

    Science.gov (United States)

    O'Sullivan, Daniel W.; Crouch, Collier C.

    2009-01-01

    Many students in general and advanced chemistry courses have difficulty understanding differences in solubility by inspecting changing values of the solubility product constants for sparingly soluble salts. In this demonstration, the concepts involved in understanding the solubility of sparingly soluble salts are illustrated visually. Utilizing…

  16. Combined homicide

    Directory of Open Access Journals (Sweden)

    Slović Živana

    2017-01-01

    Full Text Available Introduction: Combined homicide is a combination of two or more different modes of killing. These homicides occur when multiple perpetrators have different mode of killing, to hide the true manner of death, or when an initially unsuccessful attack with one weapon is abandoned and changed by another mode which is more successful, or due to availability of weapons at the scene of homicide, or unexpected appearance of possible eyewitness, or else. Case report: This case report is about 65-year old woman who was found in her residence on the floor next to the bed lying on her back with two kitchen knives in her neck. Autopsy revealed an abrasion on the frontal part of the neck and a bruise of the soft tissues of the neck with a double fracture of both greater horns of the hyoid bone and a fracture of both superior horns of the thyroid cartilage. The cause of death was exsanguination into right half of the thoracic cavity from the left subclavian artery which was cut, on the spot of stab wound in the neck. Conclusion: Hemorrhage in the soft tissue near broken hyoid bone and thyroid cartilage indicate that the victim was first strangulated and then stabbed with kitchen knives. Combined homicides are caused by one or more killers in order to accelerate the killing, or to be sure to provide the fatal outcome. This case is also interesting because the killer left weapon in the victim's neck.

  17. Co-administration of ciliary neurotrophic factor with its soluble receptor protects against neuronal death and enhances neurite outgrowth.

    Science.gov (United States)

    Ozog, Mark A; Modha, Geetanjalee; Church, John; Reilly, Rayne; Naus, Christian C

    2008-03-07

    Attempts to promote neuronal survival and repair with ciliary neurotrophic factor (CNTF) have met with limited success. The variability of results obtained with CNTF may, in part, reflect the fact that some of the biological actions of the cytokine are mediated by a complex formed between CNTF and its specific receptor, CNTFRalpha, which exists in both membrane-bound and soluble forms. In this study, we compared the actions of CNTF alone and CNTF complexed with soluble CNTFRalpha (hereafter termed "Complex") on neuronal survival and growth. Although CNTF alone produced limited effects, Complex protected against glutamate-mediated excitotoxicity via gap junction-dependent and -independent mechanisms. Further examination revealed that only Complex promoted neurite outgrowth. Differential gene expression analysis revealed that, compared with CNTF alone, Complex differentially regulates several neuroprotective and neurotrophic genes. Collectively, these findings indicate that CNTF exerts more robust effects on neuronal survival and growth when applied in combination with its soluble receptor.

  18. Fragments of HdhQ150 mutant huntingtin form a soluble oligomer pool that declines with aggregate deposition upon aging.

    Directory of Open Access Journals (Sweden)

    David Marcellin

    Full Text Available Cleavage of the full-length mutant huntingtin (mhtt protein into smaller, soluble aggregation-prone mhtt fragments appears to be a key process in the neuropathophysiology of Huntington's Disease (HD. Recent quantification studies using TR-FRET-based immunoassays showed decreasing levels of soluble mhtt correlating with an increased load of aggregated mhtt in the aging HdhQ150 mouse brain. To better characterize the nature of these changes at the level of native mhtt species, we developed a detection method that combines size exclusion chromatography (SEC and time-resolved fluorescence resonance energy transfer (TR-FRET that allowed us to resolve and define the formation, aggregation and temporal dynamics of native soluble mhtt species and insoluble aggregates in the brain of the HdhQ150 knock-in mouse. We found that mhtt fragments and not full-length mhtt form oligomers in the brains of one month-old mice long before disease phenotypes and mhtt aggregate histopathology occur. As the HdhQ150 mice age, brain levels of soluble full-length mhtt protein remain similar. In contrast, the soluble oligomeric pool of mhtt fragments slightly increases during the first two months before it declines between 3 and 8 months of age. This decline inversely correlates with the formation of insoluble mhtt aggregates. We also found that the pool-size of soluble mhtt oligomers is similar in age-matched heterozygous and homozygous HdhQ150 mouse brains whereas insoluble aggregate formation is greatly accelerated in the homozygous mutant brain. The capacity of the soluble mhtt oligomer pool therefore seems exhausted already in the heterozygous state and likely kept constant by changes in flux and, as a consequence, increased rate of insoluble aggregate formation. We demonstrate that our novel findings in mice translate to human HD brain but not HD patient fibroblasts.

  19. Computational prediction of drug solubility in lipid based formulation excipients.

    Science.gov (United States)

    Persson, Linda C; Porter, Christopher J H; Charman, William N; Bergström, Christel A S

    2013-12-01

    To investigate if drug solubility in pharmaceutical excipients used in lipid based formulations (LBFs) can be predicted from physicochemical properties. Solubility was measured for 30 structurally diverse drug molecules in soybean oil (SBO, long-chain triglyceride; TGLC), Captex355 (medium-chain triglyceride; TGMC), polysorbate 80 (PS80; surfactant) and PEG400 co-solvent and used as responses during PLS model development. Melting point and calculated molecular descriptors were used as variables and the PLS models were validated with test sets and permutation tests. Solvation capacity of SBO and Captex355 was equal on a mol per mol scale (R (2) = 0.98). A strong correlation was also found between PS80 and PEG400 (R (2) = 0.85), identifying the significant contribution of the ethoxylation for the solvation capacity of PS80. In silico models based on calculated descriptors were successfully developed for drug solubility in SBO (R (2) = 0.81, Q (2) = 0.76) and Captex355 (R (2) = 0.84, Q (2) = 0.80). However, solubility in PS80 and PEG400 were not possible to quantitatively predict from molecular structure. Solubility measured in one excipient can be used to predict solubility in another, herein exemplified with TGMC versus TGLC, and PS80 versus PEG400. We also show, for the first time, that solubility in TGMC and TGLC can be predicted from rapidly calculated molecular descriptors.

  20. Three new hydrochlorothiazide cocrystals: Structural analyses and solubility studies

    Science.gov (United States)

    Ranjan, Subham; Devarapalli, Ramesh; Kundu, Sudeshna; Vangala, Venu R.; Ghosh, Animesh; Reddy, C. Malla

    2017-04-01

    Hydrochlorothiazide (HCT) is a diuretic BCS class IV drug with poor aqueous solubility and low permeability leading to poor oral absorption. The present work explores the cocrystallization technique to enhance the aqueous solubility of HCT. Three new cocrystals of HCT with water soluble coformers phenazine (PHEN), 4-dimethylaminopyridine (DMAP) and picolinamide (PICA) were prepared successfully by solution crystallization method and characterized by single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), fourier transform -infraredspectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Structural characterization revealed that the cocrystals with PHEN, DMAP and PICA exists in P21/n, P21/c and P21/n space groups, respectively. The improved solubility of HCT-DMAP (4 fold) and HCT-PHEN (1.4 fold) cocrystals whereas decreased solubility of HCT-PICA (0.5 fold) as compared to the free drug were determined after 4 h in phosphate buffer, pH 7.4, at 25 °C by using shaking flask method. HCT-DMAP showed a significant increase in solubility than all previously reported cocrystals of HCT suggest the role of a coformer. The study demonstrates that the selection of coformer could have pronounced impact on the physicochemical properties of HCT and cocrystallization can be a promising approach to improve aqueous solubility of drugs.

  1. Water-soluble dietary fibers and cardiovascular disease.

    Science.gov (United States)

    Theuwissen, Elke; Mensink, Ronald P

    2008-05-23

    One well-established way to reduce the risk of developing cardiovascular disease (CVD) is to lower serum LDL cholesterol levels by reducing saturated fat intake. However, the importance of other dietary approaches, such as increasing the intake of water-soluble dietary fibers is increasingly recognized. Well-controlled intervention studies have now shown that four major water-soluble fiber types-beta-glucan, psyllium, pectin and guar gum-effectively lower serum LDL cholesterol concentrations, without affecting HDL cholesterol or triacylglycerol concentrations. It is estimated that for each additional gram of water-soluble fiber in the diet serum total and LDL cholesterol concentrations decrease by -0.028 mmol/L and -0.029 mmol/L, respectively. Despite large differences in molecular structure, no major differences existed between the different types of water-soluble fiber, suggesting a common underlying mechanism. In this respect, it is most likely that water-soluble fibers lower the (re)absorption of in particular bile acids. As a result hepatic conversion of cholesterol into bile acids increases, which will ultimately lead to increased LDL uptake by the liver. Additionally, epidemiological studies suggest that a diet high in water-soluble fiber is inversely associated with the risk of CVD. These findings underlie current dietary recommendations to increase water-soluble fiber intake.

  2. Assessment of Age-Related Changes in Pediatric Gastrointestinal Solubility.

    Science.gov (United States)

    Maharaj, Anil R; Edginton, Andrea N; Fotaki, Nikoletta

    2016-01-01

    Compound solubility serves as a surrogate indicator of oral biopharmaceutical performance. Between infancy and adulthood, marked compositional changes in gastrointestinal (GI) fluids occur. This study serves to assess how developmental changes in GI fluid composition affects compound solubility. Solubility assessments were conducted in vitro using biorelevant media reflective of age-specific pediatric cohorts (i.e., neonates and infants). Previously published adult media (i.e., FaSSGF, FeSSGF, FaSSIF.v2, and FeSSIF.v2) were employed as references for pediatric media development. Investigations assessing age-specific changes in GI fluid parameters (i.e., pepsin, bile acids, pH, osmolality, etc.) were collected from the literature and served to define the composition of neonatal and infant media. Solubility assessments at 37 °C were conducted for seven BCS Class II compounds within the developed pediatric and reference adult media. For six of the seven compounds investigated, solubility fell outside an 80-125% range from adult values in at least one of the developed pediatric media. This result indicates a potential for age-related alterations in oral drug performance, especially for compounds whose absorption is delimited by solubility (i.e., BCS Class II). Developmental changes in GI fluid composition can result in relevant discrepancies in luminal compound solubility between children and adults.

  3. Solubility of Calcium Phosphate in Concentrated Dairy Effluent Brines.

    Science.gov (United States)

    Kezia, K; Lee, J; Zisu, B; Chen, G Q; Gras, S L; Kentish, S E

    2017-05-24

    The solubility of calcium phosphate in concentrated dairy brine streams is important in understanding mineral scaling on equipment, such as membrane modules, evaporators, and heat exchangers, and in brine pond operation. In this study, the solubility of calcium phosphate has been assessed in the presence of up to 300 g/L sodium chloride as well as lactose, organic acids, and anions at 10, 30, and 50 °C. As a neutral molecule, lactose has a marginal but still detectable effect upon calcium solubility. However, additions of sodium chloride up to 100 g/L result in a much greater increase in calcium solubility. Beyond this point, the concentrations of ions in the solution decrease significantly. These changes in calcium solubility can readily be explained through changes in the activity coefficients. There is little difference in calcium phosphate speciation between 10 and 30 °C. However, at 50 °C, the ratio of calcium to phosphate in the solution is lower than at the other temperatures and varies less with ionic strength. While the addition of sodium lactate has less effect upon calcium solubility than sodium citrate, it still has a greater effect than sodium chloride at an equivalent ionic strength. Conversely, when these organic anions are present in the solution in the acid form, the effect of pH dominates and results in much higher solubility and a calcium/phosphate ratio close to one, indicative of dicalcium phosphate dihydrate as the dominant solid phase.

  4. Solubility and dissolution enhancement strategies: current understanding and recent trends.

    Science.gov (United States)

    Jain, Shashank; Patel, Niketkumar; Lin, Senshang

    2015-06-01

    Identification of lead compounds with higher molecular weight and lower aqueous solubility has become increasingly prevalent with the advent of high throughput screening. Poor aqueous solubility of these lipophilic compounds can drastically affect the dissolution rate and subsequently the drug absorbed in the systemic circulation, imposing a significant burden of time and money during drug development process. Various pre-formulation and formulation strategies have been applied in the past that can improve the aqueous solubility of lipophilic compounds by manipulating either the crystal lattice properties or the activity coefficient of a solute in solution or both, if possible. However, despite various strategies available in the armor of formulation scientist, solubility issue still remains an overriding problem in the drug development process. It is perhaps due to the insufficient conceptual understanding of solubility and dissolution phenomenon that hinders the judgment in selecting suitable strategy for improving aqueous solubility and/or dissolution rate. This article, therefore, focuses on (i) revisiting the theoretical and mathematical concepts associated with solubility and dissolution, (ii) their application in making rationale decision for selecting suitable pre-formulation and formulation strategies and (iii) the relevant research performed in this field in past decade.

  5. Solubility Enhancement of Raloxifene Using Inclusion Complexes and Cogrinding Method

    Directory of Open Access Journals (Sweden)

    Payal H. Patil

    2013-01-01

    Full Text Available The objective of the present work was to enhance the solubility and dissolution of practically water-insoluble drug raloxifene HCl (RLX, for the same two approaches that were used. In the first approach, drug was kneaded with hydroxypropyl-β-cyclodextrin (HPβCD, and in the second one drug was cogrinded with modified guar gum (MGG. The drug-cyclodextrin complex and drug-MGG cogrind mixtures were characterized by differential scanning calorimetry, X-ray diffraction studies, scanning electron microscopy, and Fourier transform infrared spectroscopy. The solubility and dissolution study reveals that solubility and dissolution rate of RLX remarkably increased in both methods. It was concluded that the prepared inclusion complex showed a remarkable increase in solubility and dissolution of poorly water-soluble drug raloxifene. In the cogrinding mixture, a natural modified gum is used as a surfactant and enhances the solubility and dissolution of RLX without requiring addition of organic solvent or high temperature for its preparation; thus, process is less cumbersome and cost effective. But when both methods were compared; HPβCD complexation method showed significant enhancement of drug solubility.

  6. Plasma Soluble (Prorenin Receptor Reflects Renal Damage.

    Directory of Open Access Journals (Sweden)

    Naro Ohashi

    Full Text Available (Prorenin receptor [(PRR], a specific receptor for renin and prorenin, was identified as a member of the renin-angiotensin system (RAS. (PRR is cleaved by furin, and soluble (PRR [s(PRR] is secreted into the extracellular space. Previous reports have indicated that plasma s(PRR levels show a significant positive relationship with urinary protein levels, which represent renal damage. However, it is not fully known whether plasma s(PRR reflects renal damage.We recruited 25 patients who were admitted to our hospital to undergo heminephrectomy. Plasma s(PRR levels were examined from blood samples drawn before nephrectomy. The extent of renal damage was evaluated by the levels of tubulointerstitial fibrosis. Immunohistochemical analysis of intrarenal (PRR and cell surface markers (cluster of differentiation [CD]3, CD19, and CD68 was performed on samples taken from the removed kidney. Moreover, double staining of (PRR and cell surface markers was also performed.There were significant positive relationships between plasma s(PRR and tubulointerstitial fibrosis in all the patients and those not receiving RAS blocker therapy. Significant positive relationships were found between plasma s(PRR levels and the extent of tubulointerstitial fibrosis after adjustment for age, sex, body weight, blood pressure, and plasma angiotensin II, in all the patients and those not receiving RAS blockers. Moreover, (PRR expression was elevated in infiltrated mononuclear cells but not connecting tubules or collecting ducts and vessels. Infiltrated cells positive for (PRR consisted of CD3 and CD68 but not CD19.These data suggest that plasma s(PRR levels may reflect (PRR expression levels in infiltrated mononuclear cells, which can be a surrogate marker of renal damage.

  7. Soluble Thrombomodulin and Major Orthopedic Surgery

    Directory of Open Access Journals (Sweden)

    Irina P. Antropova

    2016-09-01

    Full Text Available Background: A high level of soluble thrombomodulin (sTM is associated with a lower risk of thrombosis but can cause severe bleeding after operations. Deep vein thrombosis (DVT and blood loss are serious threats after orthopedic surgery. The aim of our pilot study was to evaluate the effect of the preoperative level of sTM on coagulation and inflammation as well as the blood loss and the development of symptomatic DVT after total large joint replacement. Methods and Results: In all patients (n=50 who underwent total hip or knee replacement, sTM, PrC, D-dimer, vWF, CRP, and platelets were determined before and after the operation. According to the preoperative sTM level, patients were divided into 2 groups: the thrombomodulin low (TML group (n=25 and thrombomodulin high (TMH group (n=25. The concentration of sTM was 4.4 [3.4, 4.7] ng/ml in the TML-group and 8.7[7.3, 10.6] ng/ml in the TMH-group. After surgery, D-dimer, vWF, platelet count and CRP were higher and total blood loss was lower in the TML group. In the TML-group, a symptomatic DVT was detected in 3(12% patients; in the TMH-group, a symptomatic DVT was identified only in 1(4% case. Conclusion: These findings support the important role of sTM in coagulation, inflammation, bleeding, and presumably in venous thrombosis after major orthopedic surgery.

  8. The effect of filter cakes enriched with soluble phosphorus used as a fertilizer on the sugarcane ratoons

    Directory of Open Access Journals (Sweden)

    Diego Henriques Santos

    2014-07-01

    Full Text Available The objective of this work was to evaluate the effect of fertilization with filter cakes enriched with soluble phosphate on sugarcane ratoons. The experiment was performed from November 2007 to December 2009 at Presidente Prudente, São Paulo State, Brazil, in a completely randomized block design in a 4 x 4 factorial arrangement, with the first factor consisting of doses of filter cake (0; 1; 2 and 4 mg ha-1 and the second doses consisting of phosphorus fertilizer (0, 50, 100, 200 kg ha-1 of P2O5 with 4 replicates. The following variables were evaluated: the number of tillers per meter, the leaf area index, soluble solids (ºBrix, stalk and sugar yield in the second crop cycle. We found a residual effect in the sugarcane ratoon after applying filter cakes enriched with soluble phosphate in the planting furrow. The initial tillering, leaf area index, stalk and sugar yield in the cane ratoon benefit from the application of filter cakes and soluble phosphate in the planting furrow. The best combination is filter cakes at a dose between 1.0 and 2.0 mg ha-1 with 100 to 200 kg ha-1 soluble phosphate applied at planting. This method obtains higher stalk and sugar yields for sugarcane ratoons.

  9. Soluble haemoglobin is a marker of recent Plasmodium falciparum infections

    DEFF Research Database (Denmark)

    Jakobsen, P H; Bygbjerg, I C; Theander, T G

    1997-01-01

    . falciparum malaria compared to the levels during acute disease. Thus, both soluble Hb and haptoglobin appear to be markers of recent P. falciparum infections. Very high levels of CRP protein were measured in some of the malaria patients at the day of treatment while lower levels were recorded 7 and 30 days...... after treatment. Soluble Hb levels were associated with malariometric parameters in a similar fashion to haptoglobin. The new Mab-based assay for measuring soluble Hb in the peripheral blood of malaria patients may be useful for future epidemiological studies of malaria....

  10. Soluble biomarkers development in osteoarthritis: from discovery to personalized medicine.

    Science.gov (United States)

    Henrotin, Yves; Sanchez, Christelle; Cornet, Anne; Van de Put, Joachim; Douette, Pierre; Gharbi, Myriam

    2015-01-01

    Specific soluble biomarkers could be a precious tool for diagnosis, prognosis and personalized management of osteoarthritic (OA) patients. To describe the path of soluble biomarker development from discovery to clinical qualification and regulatory adoption toward OA-related biomarker qualification. This review summarizes current guidance on the use of biomarkers in OA in clinical trials and their utility at five stages, including preclinical development and phase 1 to phase 4 trials. It also presents all the available regulatory requirements. The path through the adoption of a specific soluble biomarker for OA is steep but is worth the challenge due to the benefit that it can provide.

  11. QSPR Studies on Aqueous Solubilities of Drug-Like Compounds

    Directory of Open Access Journals (Sweden)

    Eduardo A. Castro

    2009-06-01

    Full Text Available A rapidly growing area of modern pharmaceutical research is the prediction of aqueous solubility of drug-sized compounds from their molecular structures. There exist many different reasons for considering this physico-chemical property as a key parameter: the design of novel entities with adequate aqueous solubility brings many advantages to preclinical and clinical research and development, allowing improvement of the Absorption, Distribution, Metabolization, and Elimination/Toxicity profile and “screenability” of drug candidates in High Throughput Screening techniques. This work compiles recent QSPR linear models established by our research group devoted to the quantification of aqueous solubilities and their comparison to previous research on the topic.

  12. Improving recombinant protein solubility in Escherichia coli ...

    African Journals Online (AJOL)

    user

    2010-11-22

    Nov 22, 2010 ... folding modulators, such as chaperone molecules, causes the convenient production of heterologous proteins. Wrong selection of chaperones will negatively affect the host cells physiology and the production of heterologous proteins. Due to this reason, type and combination of chaperone molecules.

  13. Enhanced photocatalytic hydrogen evolution by combining water soluble graphene with cobalt salts

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2014-07-01

    Full Text Available There is tremendous effort put in the pursuit for cheap and efficient catalysts for photocatalytic hydrogen evolution systems. Herein, we report an active catalyst that uses the earth-abundant element cobalt and water-dispersible sulfonated graphene. The photocatalytic hydrogen evolution activity of the catalyst was tested by using triethanolamine (TEOA as electron donor and eosin Y (EY as the photosensitizer under LED irradiation at 525 nm. Hydrogen was produced constantly even after 20 h, and the turnover number (TON reached 148 (H2/Co in 4 h with respect to the initial concentration of the added cobalt salts was shown to be 5.6 times larger than that without graphene.

  14. A combined strategy improving the expression and solubility of deoxynivalenol single-chain variable fragment antibodies

    Science.gov (United States)

    Deoxynivalenol (DON) is a secondary metabolite produced by certain species of fungi, in particular Fusarium graminearum and F. culmorum. These fungi can infest small grains causing significant economic damage to cereal crops worldwide. Animal exposure to DON can lead to reduced food or feed consumpt...

  15. Morphological Analysis and Solubility of Lead Particles: Effect of Phosphates and Implications to Drinking Water (Presentation)

    Science.gov (United States)

    Describe lead synthesis experiments conduced to model the impact of water quality on lead particles and solubility Develop a model system that can be used for lead solubility studies Understand how phosphates impact morphology and solubility transformations with time

  16. Molecular dynamics simulation of amorphous indomethacin-poly(vinylpyrrolidone) glasses: solubility and hydrogen bonding interactions.

    Science.gov (United States)

    Xiang, Tian-Xiang; Anderson, Bradley D

    2013-03-01

    (25.5 MPa(1/2)) and PVP (19.0 MPa(1/2)) suggests a small, positive free energy of mixing, although it is close to the criterion for miscibility (IMC-PVP interaction energy, predicts complete miscibility at all PVP compositions, in agreement with experimental observations. These results from MD simulations were combined with experimental values for the crystalline γ-polymorph of IMC and amorphous IMC to estimate the solubility of IMC in amorphous PVP dispersions and the theoretical enhancement in the aqueous solubility of IMC molecularly dispersed in PVP at various volume fractions. Copyright © 2012 Wiley Periodicals, Inc.

  17. Pareto-optimal reversed-phase chromatography separation of three insulin variants with a solubility constraint.

    Science.gov (United States)

    Arkell, Karolina; Knutson, Hans-Kristian; Frederiksen, Søren S; Breil, Martin P; Nilsson, Bernt

    2018-01-12

    With the shift of focus of the regulatory bodies, from fixed process conditions towards flexible ones based on process understanding, model-based optimization is becoming an important tool for process development within the biopharmaceutical industry. In this paper, a multi-objective optimization study of separation of three insulin variants by reversed-phase chromatography (RPC) is presented. The decision variables were the load factor, the concentrations of ethanol and KCl in the eluent, and the cut points for the product pooling. In addition to the purity constraints, a solubility constraint on the total insulin concentration was applied. The insulin solubility is a function of the ethanol concentration in the mobile phase, and the main aim was to investigate the effect of this constraint on the maximal productivity. Multi-objective optimization was performed with and without the solubility constraint, and visualized as Pareto fronts, showing the optimal combinations of the two objectives productivity and yield for each case. Comparison of the constrained and unconstrained Pareto fronts showed that the former diverges when the constraint becomes active, because the increase in productivity with decreasing yield is almost halted. Consequently, we suggest the operating point at which the total outlet concentration of insulin reaches the solubility limit as the most suitable one. According to the results from the constrained optimizations, the maximal productivity on the C 4 adsorbent (0.41 kg/(m 3  column h)) is less than half of that on the C 18 adsorbent (0.87 kg/(m 3  column h)). This is partly caused by the higher selectivity between the insulin variants on the C 18 adsorbent, but the main reason is the difference in how the solubility constraint affects the processes. Since the optimal ethanol concentration for elution on the C 18 adsorbent is higher than for the C 4 one, the insulin solubility is also higher, allowing a higher pool concentration

  18. Restricting the Solubility of Polysulfides in Li-S Batteries Via Electrolyte Salt Selection

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Junzheng [Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99352 USA; Han, Kee Sung [Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99352 USA; Henderson, Wesley A. [Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99352 USA; Lau, Kah Chun [Joint Center for Energy Storage Research (JCESR), Argonne National Laboratory, Argonne IL 60439 USA; Vijayakumar, Murugesan [Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99352 USA; Dzwiniel, Trevor [Joint Center for Energy Storage Research (JCESR), Argonne National Laboratory, Argonne IL 60439 USA; Pan, Huilin [Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99352 USA; Curtiss, Larry A. [Joint Center for Energy Storage Research (JCESR), Argonne National Laboratory, Argonne IL 60439 USA; Xiao, Jie [Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99352 USA; Mueller, Karl T. [Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99352 USA; Shao, Yuyan [Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99352 USA; Liu, Jun [Joint Center for Energy Storage Research (JCESR), Pacific Northwest National Laboratory, Richland WA 99352 USA

    2016-03-29

    Polysulfide solubility in the electrolyte has a critical role to the Li-S battery but the mechanism study on the solubility needs to be carefully carried out. In this paper we found that lithium 2-trifluoromethyl-4,5-dicyanoimidazole (LiTDI) reveals a suppression of the polysulfide solubility in electrolytes (relative to the most widely used electrolyte formulation) and the Li-S cells achieved homogeneous stable capacity retention upon extensive cycling and Li metal deposition on the anode. Combined experimental, simulation and calculation methods suggest the dominate disproportionation product of Li2S8 is Li2S4 in the LiTDI electrolyte due to a different interaction between lithium ion and TDI anion. The Li2S4 would continuesly form a Li4S8 dimer and be fully locallized to precipitate out. The use of the electrolyte with the LiTDI salt (with polysulfide and LiNO3 additives) enabled a cell with a high sulfur (3 mg-S cm-2) loading to deliver a 1.67 mAh cm-2 areal capacity after 300 stable cycles at a high current (2.4 mA cm-2) density.

  19. Solubility parameters, fractional polarities, and bond strengths of some intermediary resins used in dentin bonding.

    Science.gov (United States)

    Asmussen, E; Uno, S

    1993-03-01

    An effective bonding of resin composites to dentin is generally preceded by a conditioning of the surface of the dentin. Previous studies have indicated that the intermediary or adhesive resin should have specific wetting characteristics matching those of the conditioned dentin, in order that optimum bonding can be ensured. The wetting characteristics may be expressed in terms of solubility parameter (delta) and polarity (p) of the resin. The aims of the present study were to determine these variables for a number of compounds used in adhesive resins and to investigate the effects of delta and p on the shear bond strength to dentin. Solubility parameters were obtained according to the method of Small. Fractional polarities were calculated on the basis of measurements of refractive index and dielectric constant of the resins. In the measurements of bond strength, Scotchprep, EDTA + Gluma, or Al2Ox3/glycine were used as dentin conditioners in combination with intermediary resins having various delta and p. For each conditioner, the shear bond strength (BS) could be "explained" by an exponential expression of the form BS = e(a + bx), where x = (delta + cp + d)2, and where a-d are constants depending on the conditioned dentin. It may be concluded that solubility parameter and polarity of the intermediary resins are important variables in the process of bonding to dentin.

  20. Sorption, Solubility, Bond Strength and Hardness of Denture Soft Lining Incorporated with Silver Nanoparticles

    Science.gov (United States)

    Chladek, Grzegorz; Kasperski, Jacek; Barszczewska-Rybarek, Izabela; Żmudzki, Jarosław

    2013-01-01

    The colonization of denture soft lining material by oral fungi can result in infections and stomatitis of oral tissues. In this study, 0 ppm to 200 ppm of silver nanoparticles was incorporated as an antimicrobial agent into composites to reduce the microbial colonization of lining materials. The effect of silver nanoparticle incorporation into a soft lining material on the sorption, solubility, hardness (on the Shore A scale) and tensile bond strength of the composites was investigated. The data were statistically analyzed using two-way ANOVA and Newman-Keuls post hoc tests or the chi-square Pearson test at the p hardness, an increase in sorption and solubility, a decrease in bond strength and a change in the failure type of the samples. The best combination of bond strength, sorption, solubility and hardness with antifungal efficacy was achieved for silver nanoparticle concentrations ranging from 20 ppm to 40 ppm. These composites did not show properties worse than those of the material without silver nanoparticles and exhibited enhanced in vitro antifungal efficiency. PMID:23271371

  1. Spectroscopy, modeling and computation of metal chelate solubility in supercritical CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    J. F. Brennecke; M. A. Stadtherr

    1999-12-10

    The overall objectives of this project were to gain a fundamental understanding of the solubility and phase behavior of metal chelates in supercritical CO{sub 2}. Extraction with CO{sub 2} is an excellent way to remove organic compounds from soils, sludges and aqueous solutions, and recent research has demonstrated that, together with chelating agents, it is a viable way to remove metals, as well. In this project the authors sought to gain fundamental knowledge that is vital to computing phase behavior, and modeling and designing processes using CO{sub 2} to separate organics and metal compounds from DOE mixed wastes. The overall program was a comprehensive one to measure, model and compute the solubility of metal chelate complexes in supercritical CO{sub 2} and CO{sub 2}/cosolvent mixtures. Through a combination of phase behavior measurements, spectroscopy and the development of a new computational technique, the authors have achieved a completely reliable way to model metal chelate solubility in supercritical CO{sub 2} and CO{sub 2}/co-contaminant mixtures. Thus, they can now design and optimize processes to extract metals from solid matrices using supercritical CO{sub 2}, as an alternative to hazardous organic solvents that create their own environmental problems, even while helping in metals decontamination.

  2. Efficient protein production method for NMR using soluble protein tags with cold shock expression vector

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Kokoro [Fujifilm Corporation, Analysis Technology Center (Japan); Kojima, Chojiro, E-mail: kojima@protein.osaka-u.ac.j [Nara Institute of Science and Technology (NAIST), Graduate School of Biological Sciences (Japan)

    2010-11-15

    The E. coli protein expression system is one of the most useful methods employed for NMR sample preparation. However, the production of some recombinant proteins in E. coli is often hampered by difficulties such as low expression level and low solubility. To address these problems, a modified cold-shock expression system containing a glutathione S-transferase (GST) tag, the pCold-GST system, was investigated. The pCold-GST system successfully expressed 9 out of 10 proteins that otherwise could not be expressed using a conventional E. coli expression system. Here, we applied the pCold-GST system to 84 proteins and 78 proteins were successfully expressed in the soluble fraction. Three other cold-shock expression systems containing a maltose binding protein tag (pCold-MBP), protein G B1 domain tag (pCold-GB1) or thioredoxin tag (pCold-Trx) were also developed to improve the yield. Additionally, we show that a C-terminal proline tag, which is invisible in {sup 1}H-{sup 15}N HSQC spectra, inhibits protein degradation and increases the final yield of unstable proteins. The purified proteins were amenable to NMR analyses. These data suggest that pCold expression systems combined with soluble protein tags can be utilized to improve the expression and purification of various proteins for NMR analysis.

  3. Hildebrand and Hansen solubility parameters from molecular dynamics with applications to electronic nose polymer sensors.

    Science.gov (United States)

    Belmares, M; Blanco, M; Goddard, W A; Ross, R B; Caldwell, G; Chou, S-H; Pham, J; Olofson, P M; Thomas, Cristina

    2004-11-30

    We introduce the Cohesive Energy Density (CED) method, a multiple sampling Molecular Dynamics computer simulation procedure that may offer higher consistency in the estimation of Hildebrand and Hansen solubility parameters. The use of a multiple sampling technique, combined with a simple but consistent molecular force field and quantum mechanically determined atomic charges, allows for the precise determination of solubility parameters in a systematic way (sigma = 0.4 hildebrands). The CED method yields first-principles Hildebrand parameter predictions in good agreement with experiment [root-mean-square (rms) = 1.1 hildebrands]. We apply the CED method to model the Caltech electronic nose, an array of 20 polymer sensors. Sensors are built with conducting leads connected through thin-film polymers loaded with carbon black. Odorant detection relies on a change in electric resistivity of the polymer film as function of the amount of swelling caused by the odorant compound. The amount of swelling depends upon the chemical composition of the polymer and the odorant molecule. The pattern is unique, and unambiguously identifies the compound. Experimentally determined changes in relative resistivity of seven polymer sensors upon exposure to 24 solvent vapors were modeled with the CED estimated Hansen solubility components. Predictions of polymer sensor responses result in Pearson R2 coefficients between 0.82 and 0.99. Copyright 2004 Wiley Periodicals, Inc.

  4. In vivo studies of biliary ceftriaxone excretion and solubility in guinea pig hepatic bile.

    Science.gov (United States)

    Purdum, P P; Shiffman, M L; Moore, E W

    1992-10-01

    Ceftriaxone (CFTX), a third-generation cephalosporin, has occasionally been reported to produce biliary sludge composed of its calcium salt. We performed studies in guinea pigs to (1) investigate the hepatic route of CFTX excretion, (2) determine ceftriaione's effects on bile flow and composition, and (3) quantify the solubility and metastability of the calcium salt as a function of administered dose. Our results show that even at high doses ceftriaxone has only minimal effects on bile flow and biliary electrolyte secretion, either alone or in combination with bile salt (taurocholate) infusion. A significant increase in total calcium concentration was observed without change in free Ca2+ concentration, this is compatible with formation of a soluble calcium salt of ceftriaxone, as previously demonstrated in vitro. Ion products of Ca2+ and ceftriaxone as high as 3.5 times the solubility product constant without crystal formation were observed, confirming the presence of a metastable state for the calcium salt of ceftriaxone in the living animal. Biliary excretion of ceftriaxone inhibited excretion of indocyanine green, suggesting that ceftriaxone and indocyanine green share a common anionic excretory pathway in this species.

  5. Soluble protein isolated from low cost fish and fish wastes

    OpenAIRE

    Lekshmy Nair, A.; Gopakumar, K.

    1982-01-01

    The method of preparation, composition, amino acid content, protein efficiency ratio and areas of possible application of water soluble protein isolates from low cost fish and fish wastes are discussed in detail in this communication.

  6. HIGH PRESSURE PHASE EQUILIBRIUM: PREDICTION OF ESSENTIAL OIL SOLUBILITY

    Directory of Open Access Journals (Sweden)

    CARDOZO-FILHO Lúcio

    1997-01-01

    Full Text Available This work describes a method to predict the solubility of essential oils in supercritical carbon dioxide. The method is based on the formulation proposed in 1979 by Asselineau, Bogdanic and Vidal. The Peng-Robinson and Soave-Redlich-Kwong cubic equations of state were used with the van der Waals mixing rules with two interaction parameters. Method validation was accomplished calculating orange essential oil solubility in pressurized carbon dioxide. The solubility of orange essential oil in carbon dioxide calculated at 308.15 K for pressures of 50 to 70 bar varied from 1.7± 0.1 to 3.6± 0.1 mg/g. For same the range of conditions, experimental solubility varied from 1.7± 0.1 to 3.6± 0.1 mg/g. Predicted values were not very sensitive to initial oil composition.

  7. Method for Predicting Solubilities of Solids in Mixed Solvents

    DEFF Research Database (Denmark)

    Ellegaard, Martin Dela; Abildskov, Jens; O'Connell, J. P.

    2009-01-01

    A method is presented for predicting solubilities of solid solutes in mixed solvents, based on excess Henry's law constants. The basis is statistical mechanical fluctuation solution theory for composition derivatives of solute/solvent infinite dilution activity coefficients. Suitable approximations...

  8. Cadmium affects the mitochondrial viability and the acid soluble ...

    African Journals Online (AJOL)

    Cadmium affects the mitochondrial viability and the acid soluble thiols concentration in liver, kidney, heart and gills of Ancistrus brevifilis (Eigenmann, 1920). P Velasquez-Vottelerd, Y Anton, R Salazar-Lugo ...

  9. Thiolate ligands for synthesis of water-soluble gold clusters.

    Science.gov (United States)

    Ackerson, Christopher J; Jadzinsky, Pablo D; Kornberg, Roger D

    2005-05-11

    Water-soluble monolayer-protected gold clusters (MPCs) have been an object of investigation by many research groups since their first syntheses were reported in 1998 and 1999. The basic requirements for a ligand to form a monolayer protecting a gold cluster were established some time ago for alkanethiolate MPCs, but there has been no such information published for water-soluble MPCs. We identify 6 new ligands capable of forming water-soluble MPCs, as well as 22 water-soluble ligands that fail to form MPCs. Our findings contribute not only to the definition of the requirements for MPC formation but also to the variety of MPCs available for applications in chemistry and biology.

  10. The solubility of gold in silicate melts: First results

    Science.gov (United States)

    Borisov, A.; Palme, H.; Spettel, B.

    1993-01-01

    The effects of oxygen fugacity and temperature on the solubility of Au in silicate melts were determined. Pd-Au alloys were equilibrated with silicate of anorthite-diopside eutectic composition at different T-fO2 conditions. The behavior of Au was found to be similar to that of Pd reported recently. Au solubilities for alloys with 30 to 40 at. percent Au decrease at 1400 C from 12 ppm in air to 160 ppb at a log fO2 = -8.7. The slope of the log(Me-solubility) vs. log(fO2) curve is close to 1/4 for Au and the simultaneously determined Pd suggesting a formal valence of Au and Pd of 1+. Near the IW buffer Pd and Au solubilities become even less dependent on fO2 perhaps reflecting the presence of some metallic Au and Pd.

  11. Immunochemical analyses of soluble lens proteins in some marine fishes

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.

    Soluble eye lens proteins of 10 fishes, belonging to the families Clupeidae, Hemirhamphidae, Lactaridae, Scombridae, Stromatidae, Psettodidae, Bothidae and Soleidae were studied by immunoelectrophoresis using the lens antiserum of Sardinella...

  12. Internal pressure and solubility parameter as a function of pressure

    DEFF Research Database (Denmark)

    Verdier, Sylvain Charles Roland; Andersen, Simon Ivar

    2005-01-01

    The main goal of this work was to measure the solubility parameter of a complex mixture, such as a crude oil, especially as a function of pressure. Thus, its definition is explained, as well as the main approximations generally used in literature. Then, the internal pressure is investigated, since...... it is presented as an alternative of the solubility parameter. In this work, the assumption that internal pressure is a measure of the physical solubility parameter was made, i.e. representing the dispersion and polar forces. As for the pressure influence, it was seen that internal pressure reaches a maximum...... contrary to solubility parameter. An indirect method was chosen to estimate internal pressure, using thermal expansivities (determined by microcalorimetry) and isothermal compressibilities (determined by density measurements). The uncertainty is within 2% for the expansivity and 0.1% for the density. Five...

  13. Water-soluble dopamine-based polymers for photoacoustic imaging

    NARCIS (Netherlands)

    Repenko, T.; Fokong, S.; De Laporte, L.; Go, D.; Kiessling, F.; Lammers, Twan Gerardus Gertudis Maria; Kuehne, A.

    2015-01-01

    Here we present a facile synthetic method yielding a linear form of polydopamine via Kumada-coupling, which can be converted into water-soluble melanin, generating high contrast in photoacoustic imaging.

  14. Characterization of Acid Soluble Collagen from Redbelly Yellowtail Fusilier Fish Skin (Caesio cuning

    Directory of Open Access Journals (Sweden)

    Ika Astiana

    2016-04-01

    Full Text Available Fish skin can be used as raw material for producing collagen. The collagen can be extracted by chemical or combination of chemical and enzymatic processes. Extraction of collagen chemically can do with the acid process that produces acid soluble collagen (ASC. This study aimed to determine the optimum concentration and time of pretreatment and extraction, also to determine the characteristics of the acid soluble collagen from the skin of yellow tail fish. Extraction of collagen done by pretreatment using NaOH at the concentration of 0.05; 0.1; and 0.15 M and extraction using acetic acid at the concentration of 0.3; 0.5; and 0.7 M. Pretreatment NaOH with concentration 0.05 M and soaking time of 8 hours is the best combination for eliminating non collagen protein. Combination treatment of acetic acid at the concentration of 0.3 M for 3 days obtained the best solubility. The yield of collagen ASC was 18.4±1.49% (db and 5.79±0.47% (wb. Amino acid composition that is dominant in the ASC collagen was glycine (25.09±0.003%, alanine (13.71±0.075%, and proline (12.15±0.132%. Collagen from yellow tail fish skin has α1, α2, β and γ protein structure with the molecular weight of 125, 113, 170-181, and 208 KDa. The transition and melting temperatures of collagen were 67.69oC and 144.4oC. The surface structure of collagen by analysis of SEM has fibers on the surface.

  15. THE SOLUBILITY OF MILAS BAUXITE ORE IN SULPHURIC ACI

    Directory of Open Access Journals (Sweden)

    Mustafa GULFEN

    2001-06-01

    Full Text Available The effects of calcination conditions,sulphuric acid concentrations and dissolvingtemperature and period as parameters to thesolubility of the bauxite ore from Gobekdagı reservesin Mugla-Milas region were investigated. The bauxitesamples were calcined in different periods at differenttemperatures. Then the solubility of the calcinedbauxite samples in sulphuric acid solution wasexamined. Dissolving activation energy (Ea wascalculated using the optimum kinetics equation andthe results obtained from the solubility studiesexamined dissolving temperatures and periods

  16. Fluorine-functionalized ionic liquids with high oxygen solubility

    OpenAIRE

    Vanhoutte, Gijs; Hojniak, Sandra; Bardé, Fanny; Binnemans, Koen; Fransaer, Jan

    2018-01-01

    Eight fluorine-functionalized ionic liquids were synthesized and the oxygen solubility was compared to commercial ionic liquids without the extra fluorinated chain. The concentration of dissolved oxygen increased with the fluorine content of the alkyl chain, which can be attached either to the cation or the anion. This approach maintains the freedom to design an ionic liquid for a specific application, while at the same time the oxygen solubility is increased.

  17. ENHANCEMENT OF SOLUBILITY AND DISSOLUTION PROPERTY OF GRISEOFULVIN BY NANOCRYSTALLIZATION

    OpenAIRE

    Phanchaxari M Dandagi; Sumit Kaushik; Shaktish Telsang

    2011-01-01

    The aim of this study was to develop the formulation of griseofulvin by nanocrystallization for the enhancement of solubility and dissolution property of drug. In the present study the area of interest are drugs belonging to class II of BCS classification. Nanocrystal is a new carrier free colloidal drug delivery system with particle size ranging from 100-1000 nm, and is considered as a viable drug delivery strategy to develop the poorly soluble drugs. In the present work an attempt was made ...

  18. The solubilities of benzene polycarboxylic acids in water

    Energy Technology Data Exchange (ETDEWEB)

    Apelblat, Alexander [Department of Chemical Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel)]. E-mail: apelblat@bgu.ac.il; Manzurola, Emanuel [Department of Chemical Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel); Abo Balal, Nazmia [Negev Academic College of Engineering, Beer Sheva (Israel)

    2006-05-15

    The solubilities in water of all benzene polycarboxylic acids are discussed, using data determined in this work (benzoic, terephthalic, trimellitic, trimesic, and pyromellitic acids) and available from the literature (benzoic, phthalic, isophthalic, terephthalic, hemimellitic, trimelitic, trimesic, mellophanic, prehnitic, pyromellitic, benzene-pentacarboxylic and mellitic acids). The apparent molar enthalpies of solution at the saturation point for these benzene polycarboxylic acids were determined from the temperature dependence of the solubilities.

  19. Immunoglobulin response to bluetongue virus soluble antigen in subcutaneous chambers.

    Science.gov (United States)

    Hajer, I; Jochim, M M; Lauerman, L H

    1977-06-01

    Group-specific antibodies were produced by inoculation of bluetongue virus soluble antigen into polyethylene chambers implanted subcutaneously in 8 rabbits and 2 sheep. For comparison, 5 rabbits and 1 sheep were inoculated intramuscularly with the soluble antigen in Freund's complete adjuvant. Antibodies present in the serum and chamber fluids were detected by the agar gel precipitin or serum-neutralization tests, qualitatively examined by immunoelectrophoresis and immunofluorescence, and quantitated by electroimmunodiffusion.

  20. Controllable Soluble Protein Concentration Gradients in Hydrogel Networks**

    OpenAIRE

    Peret, Brian J.; William L Murphy

    2008-01-01

    Here we report controlled formation of sustained, soluble protein concentration gradients within hydrated polymer networks. The approach involves spatially localizing proteins or biodegradable, protein-loaded microspheres within hydrogels to form a protein-releasing “depot”. Soluble protein concentration gradients are then formed as the released protein diffuses away from the localized source. Control over key gradient parameters, including maximum concentration, gradient magnitude, slope, an...

  1. Soluble and stable zethrenebis(dicarboximide) and its quinone

    KAUST Repository

    Sun, Zhe

    2010-10-15

    Soluble and stable zethrenebis(dicarboximide) (1) was synthesized by an in situ Stille cross coupling/transannular cyclization reaction. 1 showed largely improved photostability and solubility compared with the very unstable zethrene and it also exhibited far-red absorption and emission with high photoluminescence quantum yield. Bromination of 1 with NBS/DMF gave its quinone form 2 via an unusual pathway. © 2010 American Chemical Society.

  2. Constraining the Solubility of Aerosol Fe using US GEOTRACES Data

    Science.gov (United States)

    Aguilar-Islas, A. M.; Buck, C. S.; Rember, R.; Landing, W. M.

    2016-02-01

    Atmospheric deposition represents an important input of micronutrients to surface waters, and is of particular interest as an input for the limiting micronutrient iron. The solubility of aerosol iron after deposition is not well constrained, and it has been shown to vary principally with aerosol composition, although dissolution methodologies also contribute to the observed variability. To address procedural artifacts and arrive at a better constrained estimate of aerosol iron fractional solubility, a flow-through on-board protocol designed to minimize experimental artifacts and to simulate conditions experienced by deposited aerosols was used during the US Atlantic GEOTRACES cruises and compared to laboratory leaching methods. Here we present results of the fractional solubility of aerosol iron obtained during the US GEOTRACES Atlantic and Pacific cruises, and suggest revising estimates for this parameter. Our data provides a more constrained upwardly adjusted estimate in the range of 8% to 14% solubility for iron in aerosols dominated by lithogenic sources, and a fractional solubility of 15% to 25% for iron in aerosols from air masses impacted by anthropogenic sources. Greater variability (6% to 55%) was observed in the solubility of iron in aerosols from maritime air masses.

  3. Molecular Simulation of Gas Solubility in Nitrile Butadiene Rubber.

    Science.gov (United States)

    Khawaja, M; Sutton, A P; Mostofi, A A

    2017-01-12

    Molecular simulation is used to compute the solubility of small gases in nitrile butadiene rubber (NBR) with a Widom particle-insertion technique biased by local free volume. The convergence of the method is examined as a function of the number of snapshots upon which the insertions are performed and the number of insertions per snapshot and is compared to the convergence of the unbiased Widom insertion technique. The effect of varying the definition of local free volume is also investigated. The acrylonitrile content of the polymer is altered to examine its influence on the solubility of helium, CO2, and H2O, and the solubilities of polar gases are found to be enhanced relative to those of nonpolar gases, in qualitative agreement with experiment. To probe this phenomenon further, the solubilities are decomposed into contributions from the neighborhoods of different atoms, using a Voronoi cell construction, and a strong bias is found for CO2 and H2O in particular to be situated near nitrogen sites in the elastomer. Temperature is shown to suppress the solubility of CO2 and H2O but to increase that of helium. Increasing pressure is found to suppress the solubility of all gases but at different rates, according to a balance between their molecular sizes and electrostatic interactions with the polymer. These results are relevant to the use of NBR seals at elevated temperatures and pressures, such as in oil and gas wells.

  4. Study of pH-dependent drugs solubility in water

    Directory of Open Access Journals (Sweden)

    Pobudkowska A.

    2014-01-01

    Full Text Available The solubilities of five sparingly soluble drug-compounds in water have been measured at constant temperatures (298.1K and 310.1K by the classical saturation shake-flask method. All substances presented in this work are derivatives of anthranilic acid: flufenamic acid, (FLU, mefenamic acid, (MEF, niflumic acid, (NIF, diclofenac sodium, (DIC, and meclofenamic sodium, (MEC. All of them have anti-inflammatory action. Since the aqueous solubility of the ionized drug is significantly higher than the unionized, the experimental conditions that affect equilibrium solubility values such as composition of aqueous buffer have been examined. The Henderson-Hasselbalch (HH relationship has been used to predict the pH-dependent solubility profiles of chosen drugs at two temperatures. For this purpose the pKa values of the investigated drugs have been determined with Bates-Schwarzenbach spectrophotometric method at temperature 310.1 K. At temperature 298.1K these values were reported earlier. Similar values of pKa were obtained from the solubility measurements.

  5. Solubility determination as an alternative to migration measurements.

    Science.gov (United States)

    Bodai, Zsolt; Jakab, Péter Pál; Novák, Márton; Nyiri, Zoltán; Szabó, Bálint Sámuel; Rikker, Tamás; Eke, Zsuzsanna

    2016-01-01

    Solubility values for six UV stabilisers (Cyasorb UV-1164, Tinuvin P, Tinuvin 234, Tinuvin 326, Tinuvin 327 and Tinuvin 1577) and five antioxidants (Irgafos 168, Irganox 1010, Irganox 3114, Irganox 3790 and Irganox 565) were determined in all the liquid food simulants (3% (m/V) acetic acid-water mixture, 10% (V/V), 20% (V/V), 50% (V/V) ethanol-water mixture and vegetable oil) proposed in European Union Regulation No. 10/2011/EC, as well as in fruit juice and cola drink. The applied method was obtained by modification of the method for the determination of water solubility as described in OECD guideline Test No. 105. By using ultrasonication and shorter equilibration time, the time demand of the solubility determinations were decreased notably. Solubility values proved to be lower than the specific migration limits (as specified in 10/2011/EC) at 25 °C for almost all target compounds in food simulants A, B, C and D1 as well as in fruit juice and cola drink. The exceptions were Tinuvin P and Irganox 3790 in simulant D1. The solubility in food simulant D2 was higher than 1000 µg ml(-1) for all target compounds. These results show that the solubility of some additives in food simulants can be so low that it makes migration studies for certain additive-food simulant pairs dispensable.

  6. Solubility Advantage (and Disadvantage) of Pharmaceutical Amorphous Solid Dispersions.

    Science.gov (United States)

    Huang, Siyuan; Mao, Chen; Williams, Robert O; Yang, Chia-Yi

    2016-12-01

    The solubility of a drug is ultimately governed by its chemical potential as it is present in the undissolved solute. For a pharmaceutical amorphous solid dispersion (ASD), its solubility depends on the state and composition of the undissolved solute when the ASD is equilibrated with water. Concerning the undissolved solute phase that can contain up to 3 components (drug, polymer, and water), we developed a complete thermodynamic model to calculate the chemical potential of a drug in the multicomponent, amorphous system. This approach enables the estimation of the true solubility advantage of ASD from calorimetric measurements and moisture sorption isotherms. Both theoretical estimation and experimental studies, using indomethacin (IMC)/Eudragit E ASD systems, show that the solubility advantage of the amorphous IMC is significantly reduced through ASD formation and water partitioning. For the ASD with 70% drug loading, the solubility of IMC is lower than its crystalline counterpart. Our results show that stabilization through the ASD formation and water sorption can be manifested by the lowering of drug solubility; they demonstrate that the core property in ASD development is the drug chemical potential, which is essentially the thermodynamic driving force and can be quantitated using the model presented in this work. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  7. Factors affecting the solubility of Bacillus halmapalus alpha-amylase

    DEFF Research Database (Denmark)

    Faber, Cornelius; Hobley, Timothy John; Mollerup, Jørgen

    2008-01-01

    A detailed study of the solubility of recombinant Bacillus halmapalus alpha-amylase has been conducted. A semi-purified preparation from a bulk crystallisation was chos en that contained six isoforms with pI-values of between 5.5 and 6.1. The solubility was strongly affected by pH and could...... be reduced approximately 200-fold at pH 6 as compared to pH 10, leaving only 0.1 mg/mL in solution. Solubility could also be dramatically manipulated using salts. The choice of anions was found to be more important than of the cations, and the lowest solubility was found using sodium sulphate. For the anions......, solubility followed the order expected from the Hofmeister series, however, a more complex behaviour was seen for the cations. With the exception of lithium, their efficiency to influence the solubility was reversed to what was expected. The polydispersity of the solution was reduced by salt addition...

  8. Modeling how soluble microbial products (SMP) support heterotrophic bacteria in autotroph-based biofilms

    DEFF Research Database (Denmark)

    Merkey, Brian; Rittmann, Bruce E.; Chopp, David L.

    2009-01-01

    . In this paper, we develop and use a mathematical model to describe a model biofilm system that includes autotrophic and heterotrophic bacteria and the key products produced by the bacteria. The model combines the methods of earlier multi-species models with a multi-component biofilm model in order to explore...... the interaction between species via exchange of soluble microbial products (SMP). We show that multiple parameter sets are able to describe the findings of experimental studies, and that heterotrophs growing on autotrophically produced SMP may pursue either r- or K-strategies to sustain themselves when SMP...

  9. Elucidation of substituted ester group position in octenylsuccinic anhydride modified sugary maize soluble starch.

    Science.gov (United States)

    Ye, Fan; Miao, Ming; Huang, Chao; Lu, Keyu; Jiang, Bo; Zhang, Tao

    2014-12-03

    The octenylsuccinic groups in esterification-modified sugary maize soluble starches with a low (0.0191) or high (0.0504) degree of substitution (DS) were investigated by amyloglucosidase hydrolysis followed by a combination of chemical and physical analysis. The results showed the zeta-potential remained at approximately the same value regardless of excessive hydrolysis. The weight-average molecular weight decreased rapidly and reached 1.22 × 10(7) and 1.60 × 10(7) g/mol after 120 min for low-DS and high-DS octenylsuccinic anhydride (OSA) modified starch, respectively. The pattern of z-average radius of gyration as well as particle size change was similar to that of Mw, and z-average radius of gyration decreased much more slowly, especially for high-DS OSA starch. Compared to native starch, two characteristic absorption peaks at 1726.76 and 1571.83 cm(-1) were observed in FT-IR spectra, and the intensity of absorption peaks increased with increasing DS. The NMR results showed that OSA starch had several additional peaks at 0.8-3.0 ppm and a shoulder at 5.56 ppm for OSA substituents, which were grafted at O-2 and O-3 positions in soluble starch. The even distribution of OSA groups in the center area of soluble starch particle has been directly shown under CLSM. Most substitutions were located near branching points of soluble starch particles for a low-DS modified starch, whereas the substituted ester groups were located near branching points as well as at the nonreducing ends in OSA starch with a high DS.

  10. Cyclodextrins and ternary complexes: technology to improve solubility of poorly soluble drugs

    Directory of Open Access Journals (Sweden)

    Janisse Crestani de Miranda

    2011-12-01

    Full Text Available Cyclodextrins (CDs are cyclic oligosaccharides composed of D-glucopyranoside units linked by glycosidic bonds. Their main property is the ability to modify the physicochemical and biological characteristics of low-soluble drugs through the formation of drug:CD inclusion complexes. Inclusion complexation requires that host molecules fit completely or partially within the CD cavity. This adjustment is directly related to the physicochemical properties of the guest and host molecules, easy accommodation of guest molecules within the CD cavity, stoichiometry, therapeutic dose, and toxicity. However, dosage forms may achieve a high volume, depending on the amount of CD required. Thus, it is necessary to increase solubilization efficiency in order to use smaller amounts of CD. This can be achieved by adding small amounts of water-soluble polymers to the system. This review addresses aspects related to drug complexation with CDs using water-soluble polymers to optimize the amount of CD used in the formulation in order to increase drug solubility and reduce dosage form volume.Ciclodextrinas (CDs são oligossacarídeos cíclicos, compostos por unidades D-glicopiranosídicas ligadas entre si por meio de ligações glicosídicas e sua principal propriedade está na capacidade de alterar as características físico-químicas e biológicas de fármacos com baixa solubilidade por meio da formação de complexos de inclusão fármaco:CD. Para a formação dos complexos de inclusão a molécula hospedeira necessita ajustar-se total ou parcialmente no interior da cavidade da CD, onde este ajuste está diretamente ligado a propriedades físico-químicas da molécula hóspede e hospedeira, facilidade de alojamento da molécula hóspede no interior da cavidade da CD, estequiometria, dose terapêutica e toxicidade. No entanto, as formas farmacêuticas podem atingir um elevado volume, em função da quantidade de CD requerida, sendo necessário aumentar sua efici

  11. Soluble fibers from psyllium improve glycemic response and body weight among diabetes type 2 patients (randomized control trial).

    Science.gov (United States)

    Abutair, Ayman S; Naser, Ihab A; Hamed, Amin T

    2016-10-12

    Water-soluble dietary fibers intake may help control blood glucose and body weight. The objective of the study was to determine whether soluble fiber supplementation from psyllium improves glycemic control indicators and body weight in type 2 diabetic patients. Forty type 2 diabetes patients, non-smoker, aged >35 years were stratified to different strata according to sex, age, body mass index (BMI) and fasting blood sugar level (FBS) and randomly assigned into two groups; The intervention group which consists of 20 participants was on soluble fiber (10.5 g daily), and the control group which consist of 20 participants continued on their regular diet for eight weeks duration. After 8 weeks of intervention, soluble fiber supplementation showed significant reduction in the intervention group in BMI (p < 0.001) when compared with the control group. Moreover, water soluble fiber supplementation proven to improve FBS (163 to 119 mg/dl), HbA1c (8.5 to 7.5 %), insulin level (27.9 to 19.7 μIU/mL), C-peptide (5.8 to 3.8 ng/ml), HOMA.IR (11.3 to 5.8) and HOMA-β % (103 to 141 %). The reduction in glycemic response was enhanced by combining soluble fiber to the normal diet. Consumption of foods containing moderate amounts of these fibers may improve glucose metabolism and lipid profile in type 2 diabetes patients. Current Controlled Trials PHRC/HC/28/15 .

  12. Nanocrystal Dissolution Kinetics and Solubility Increase Prediction from Molecular Dynamics: The Case of α-, β-, and γ-Glycine.

    Science.gov (United States)

    Parks, Conor; Koswara, Andy; Tung, Hsien-Hsin; Nere, Nandkishor K; Bordawekar, Shailendra; Nagy, Zoltan K; Ramkrishna, Doraiswami

    2017-04-03

    Nanocrystals are receiving increased attention for pharmaceutical applications due to their enhanced solubility relative to their micron-sized counterpart and, in turn, potentially increased bioavailability. In this work, a computational method is proposed to predict the following: (1) polymorph specific dissolution kinetics and (2) the multiplicative increase in the polymorph specific nanocrystal solubility relative to the bulk solubility. The method uses a combination of molecular dynamics and a parametric particle size dependent mass transfer model. The method is demonstrated using a case study of α-, β-, and γ-glycine. It is shown that only the α-glycine form is predicted to have an increasing dissolution rate with decreasing particle size over the range of particle sizes simulated. On the contrary, γ-glycine shows a monotonically increasing dissolution rate with increasing particle size and dissolves at a rate 1.5 to 2 times larger than α- or β-glycine. The accelerated dissolution rate of γ-glycine relative to the other two polymorphs correlates directly with the interfacial energy ranking of γ > β > α obtained from the dissolution simulations, where γ- is predicted to have an interfacial energy roughly four times larger than either α- or β-glycine. From the interfacial energies, α- and β-glycine nanoparticles were predicted to experience modest solubility increases of up to 1.4 and 1.8 times the bulk solubility, where as γ-glycine showed upward of an 8 times amplification in the solubility. These MD simulations represent a first attempt at a computational (pre)screening method for the rational design of experiments for future engineering of nanocrystal API formulations.

  13. Proteolysis during ensilage of forages varying in soluble sugar content.

    Science.gov (United States)

    Davies, D R; Merry, R J; Williams, A P; Bakewell, E L; Leemans, D K; Tweed, J K

    1998-02-01

    The effect of contrasting concentrations of water-soluble carbohydrates of herbage on silage fermentation and composition was examined using grass with high [250 g/kg of dry matter (DM)] concentrations of water-soluble carbohydrates and grass and clover with low (66 g/kg of DM) concentrations of water-soluble carbohydrates. Herbages were ensiled untreated, after inoculation with lactic acid bacteria, or after treatment with formic acid. Good quality silages were produced from herbage with high concentrations of water-soluble carbohydrates, regardless of treatment, and all pH values were below 3.7 after 90 d of ensilage. However, the silage formed from inoculated herbage had a significantly lower concentration of ammonia N and a significantly higher proportion of residual ribulose-1,5-bisphosphate carboxylase compared with the other two silages. Fast protein liquid chromatography (Pharmacia, Uppsala, Sweden) was used to measure ribulose-1,5-bisphosphate carboxylase, and measurement of true plant protein fractions in herbage and silage showed benefits over traditional measurements such as the measurement of N and ammonia N. Herbages with low concentrations of water-soluble carbohydrates produced inferior quality silages that had lower ribulose-1,5-bisphosphate carboxylase contents and higher ammonia N contents, regardless of treatment; few significant differences were observed among treatments. Under good ensiling conditions, when available water-soluble carbohydrate is adequate, the use of inoculants can improve fermentation characteristics and increase the ribulose-1,5-bisphosphate carboxylase content of silages. However, when the herbage has low concentrations of water-soluble carbohydrates, even in inoculated herbages, lactic acid bacteria may follow a heterofermentative pathway instead of a homofermentative pathway, which can result in a decrease in silage quality and a reduction in intact ribulose-1,5-bisphosphate carboxylase.

  14. Effervescence Assisted Fusion Technique to Enhance the Solubility of Drugs.

    Science.gov (United States)

    Alam, Mohd Aftab; Al-Jenoobi, Fahad I; Al-Mohizea, Abdullah M; Ali, Raisuddin

    2015-12-01

    The solubility of five poorly soluble drugs was enhanced by using an effervescence assisted solid dispersion (EASD) technique. EASDs were prepared by using modified fusion method. Drug and hydrophilic carrier were melted, and in this molten mixture, effervescence was generated by adding effervescence couple comprising organic acid (citric acid) and carbonic base (sodium bicarbonate). Solubility of drug powders, solid dispersions, and EASDs was determined at 25°C using shake flask method. Atorvastatin calcium, cefuroxime axetil, clotrimazole, ketoconazole, and metronidazole benzoate were estimated using a spectrophotometer at 246, 280, 260, 230, and 232 nm (λ max), respectively. Solubility of atorvastatin calcium (from 100 to 345 μg/ml), cefuroxime axetil (from 441 to 1948 μg/ml), clotrimazole (from 63 to 677 μg/ml), ketoconazole (from 16 to 500 μg/ml), and metronidazole benzoate (from 112 to 208 μg/ml) in EASDs was enhanced by 3.45-, 4.4-, 10.7-, 31.2-, and 1.8-fold, respectively. Scanning electron micrographs of drug powder, solid dispersion, and EASDs were compared. Scanning electron micrographs of EASDs showed a uniform distribution of drug particles in the carrier matrix. Morphology (size and shape) of cefuroxime axetil particles was altered in solid dispersion as well as in EASD. EASDs showed better solubility enhancement than conventional solid dispersions. The present technique is better suitable for drugs having a low melting point or melt without charring. Effervescence assisted fusion technique of preparing solid dispersions can be employed for enhancing solubility, dissolution, and bioavailability of poorly soluble drugs.

  15. One-pot synthesis and control of aqueous soluble and organic soluble carbon dots from a designable waterborne polyurethane emulsion

    Science.gov (United States)

    Gu, Jiangjiang; Hu, Donghua; Huang, Jin; Huang, Xin; Zhang, Qiuhong; Jia, Xudong; Xi, Kai

    2016-02-01

    Carbon dots (CDs) have a wide range of applications and have drawn great interest in the recent decade. The fabrication and control of CDs with different solubilities are still urgent problems for their practical use. In this paper, aqueous soluble and organic soluble CDs (ACDs, OCDs) were produced by one-pot hydrothermal treatment of a designable waterborne polyurethane (WPU) emulsion. The difference in the solubility and fluorescence of these two kinds of CDs was attributed to the various functional groups on the surface, which were derived from the different segment fragments formed by hydrothermal treatment of a block polymer. It was found that the yields of the ACDs and OCDs could be regulated by means of selecting different soft segments in WPU. The more hydrophobic soft segments could result in an increase of the OCDs and a decrease of the ACDs. While the soft segments were hydrophilic or hydrolysable under hydrothermal conditions, only ACDs were obtained. The ACDs had good fluorescence and showed low cytotoxicity for use in multicolour bio-imaging. The OCDs processed good solubility in a wide range of organic solvents and were suitable for preparing fluorescent composite films with polymers.Carbon dots (CDs) have a wide range of applications and have drawn great interest in the recent decade. The fabrication and control of CDs with different solubilities are still urgent problems for their practical use. In this paper, aqueous soluble and organic soluble CDs (ACDs, OCDs) were produced by one-pot hydrothermal treatment of a designable waterborne polyurethane (WPU) emulsion. The difference in the solubility and fluorescence of these two kinds of CDs was attributed to the various functional groups on the surface, which were derived from the different segment fragments formed by hydrothermal treatment of a block polymer. It was found that the yields of the ACDs and OCDs could be regulated by means of selecting different soft segments in WPU. The more

  16. Inhalable bioresponsive chitosan microspheres of doxorubicin and soluble curcumin augmented drug delivery in lung cancer cells.

    Science.gov (United States)

    Jyoti, Kiran; Pandey, Ravi Shankar; Kush, Preeti; Kaushik, Dinesh; Jain, Upendra Kumar; Madan, Jitender

    2017-05-01

    In present investigation, doxorubicin (Dox) and soluble curcumin (Cur-2-HP-β-CD-complex) combination was simultaneously loaded in inhalable bioresponsive chitosan microspheres (Dox/Cur-2-HP-β-CD-complex-elastin-CMs) bearing a substrate-stimuli, elastin. The mean particle size and mean aerodynamic diameter of inhalable bioresponsive microspheres displayed noteworthy differences after incorporation of elastin. Moreover, combination of Dox and soluble curcumin was molecularly dispersed in microspheres matrix as substantiated by a range of spectral techniques. Inhalable bioresponsive microspheres released astonishingly higher amount of Dox in presence of elastase enzyme at pH∼5.5 in comparison to pH∼7.4. However, the release of soluble curcumin from tailored bioresponsive microspheres in presence of elastase enzyme was independent of pH. Consistently, inhalable bioresponsive microspheres exhibited outstandingly lower IC 50 of 3.4-μM in comparison to 6.5-μM of inhalable drug loaded microspheres (Dox/Cur-2-HP-β-CD-complex-CMs) bearing no elastin, against A549, non-small cell lung cancer cells. The superior therapeutic profile of inhalable bioresponsive microspheres may be attributed to enhanced drug release and consequently augmented drug exposure to A549 cells expressing elastase enzyme. In this way, stimuli triggered drug release from tailored inhalable bioresponsive microspheres boosted the phenomena of apoptosis in A549 cells. In conclusion, Dox/Cur-2-HP-β-CD-complex-elastin-CMs warrant further in-vivo tumor regression study to prove its therapeutic efficacy. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Nanosizing of a poorly soluble drug: technique optimization, factorial analysis, and pharmacokinetic study in healthy human volunteers.

    Science.gov (United States)

    Elsayed, Ibrahim; Abdelbary, Aly Ahmed; Elshafeey, Ahmed Hassen

    2014-01-01

    Diacerein (DCN) has low aqueous solubility (3.197 mg/L) and, consequently, low oral bioavailability (35%-56%). To increase both the solubility and dissolution rate of DCN while maintaining its crystalline nature, high pressure homogenization was used but with only a few homogenization cycles preceded by a simple bottom-up technique. The nanosuspensions of DCN were prepared using a combined bottom-up/top-down technique. Different surfactants - polyvinyl alcohol, sodium deoxycholate, and sodium dodecyl sulfate - with different concentrations were used for the stabilization of the nanosuspensions. Full factorial experimental design was employed to investigate the influence of formulation variables on nanosuspension characteristics using Design-Expert(®) Software. Particle size (PS), zeta potential, saturation solubility, in vitro dissolution, and drug crystallinity were studied. Moreover, the in vivo performance of the optimized formula was assessed by bioavailability determination in healthy human volunteers. The concentration of surfactant had a significant effect on both the PS and polydispersity index values. The 1% surfactant concentration showed the lowest PS and polydispersity index values compared with other concentrations. Both type and concentration of surfactant had significant effects on the zeta potential. Formula F8 (containing 1% sodium deoxycholate) and Formula F12 (containing 1% sodium dodecyl sulfate) had the highest desirability values (0.952 and 0.927, respectively). Hence, they were selected for further characterization. The saturated solubility and mean dissolution time, in the case of F8 and F12, were significantly higher than the coarse drug powder. Techniques utilized in the nanocrystals' preparation had no effect on DCN crystalline state. The selected formula (F12) showed a higher bioavailability compared to the reference market product with relative bioavailability of 131.4%. The saturation solubility, in vitro dissolution rate and relative

  18. Distribution of soluble amino acids in maize endosperm mutants

    Directory of Open Access Journals (Sweden)

    Toro Alejandro Alberto

    2003-01-01

    Full Text Available For human nutrition the main source of vegetable proteins are cereal and legume seeds. The content of total soluble amino acids in mature endosperm of wild-type, opaque and floury maize (Zea mays L. mutants were determined by HPLC. The total absolute concentration of soluble amino acids among the mutants varied depending on the mutant. The o11 and o13 mutants exhibited the highest average content, whereas o10, fl3 and fl1 exhibited the lowest average content. In general, the mutants exhibited similar concentrations of total soluble amino acids when compared to the wild-type lines, with the clear exception of mutants o11 and fl1, with the o11 mutant exhibiting a higher concentration of total soluble amino acids when compared to its wild-type counterpart W22 and the fl1 mutant a lower concentration when compared to its wild-type counterpart Oh43. For methionine, the mutants o2 and o11 and wild-type Oh43 exhibited the highest concentrations of this amino acid. Significant differences were not observed between mutants for other amino acids such as lysine and threonine. The high lysine concentrations obtained originally for these mutants may be due to the amino acids incorporated into storage proteins, but not those present in the soluble form.

  19. Fentanyl Buccal Soluble Film: A Review in Breakthrough Cancer Pain.

    Science.gov (United States)

    Garnock-Jones, Karly P

    2016-05-01

    Fentanyl buccal soluble film (Onsolis(®), Breakyl(®), Painkyl™) comprises two layers: a mucoadhesive layer containing the active drug, and an inactive layer with the aim of preventing the diffusion of fentanyl into the oral cavity. It is approved in several countries worldwide, including the USA and those of the EU, for the management of breakthrough cancer pain in opioid-tolerant, adult patients with cancer. This article reviews the pharmacological properties of fentanyl buccal soluble film and its clinical efficacy and tolerability in these patients. Fentanyl buccal soluble film provides an additional option for transmucosal delivery of fentanyl, with approximately half of the dose undergoing an initial, rapid absorption via the buccal mucosa (accounting for its high bioavailability). In clinical trials, fentanyl buccal soluble film was associated with significant improvements in pain intensity scores versus placebo and was generally well tolerated. The most common adverse events were typical opioid-associated adverse events, such as nausea and vomiting. Fentanyl buccal soluble film is a useful option for the treatment of breakthrough cancer pain in opioid-tolerant patients.

  20. Identifying protein domains by global analysis of soluble fragment data.

    Science.gov (United States)

    Bulloch, Esther M M; Kingston, Richard L

    2014-11-15

    The production and analysis of individual structural domains is a common strategy for studying large or complex proteins, which may be experimentally intractable in their full-length form. However, identifying domain boundaries is challenging if there is little structural information concerning the protein target. One experimental procedure for mapping domains is to screen a library of random protein fragments for solubility, since truncation of a domain will typically expose hydrophobic groups, leading to poor fragment solubility. We have coupled fragment solubility screening with global data analysis to develop an effective method for identifying structural domains within a protein. A gene fragment library is generated using mechanical shearing, or by uracil doping of the gene and a uracil-specific enzymatic digest. A split green fluorescent protein (GFP) assay is used to screen the corresponding protein fragments for solubility when expressed in Escherichia coli. The soluble fragment data are then analyzed using two complementary approaches. Fragmentation "hotspots" indicate possible interdomain regions. Clustering algorithms are used to group related fragments, and concomitantly predict domain location. The effectiveness of this Domain Seeking procedure is demonstrated by application to the well-characterized human protein p85α. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Solubility, photostability and antifungal activity of phenylpropanoids encapsulated in cyclodextrins.

    Science.gov (United States)

    Kfoury, Miriana; Lounès-Hadj Sahraoui, Anissa; Bourdon, Natacha; Laruelle, Frédéric; Fontaine, Joël; Auezova, Lizette; Greige-Gerges, Hélène; Fourmentin, Sophie

    2016-04-01

    Effects of the encapsulation in cyclodextrins (CDs) on the solubility, photostability and antifungal activities of some phenylpropanoids (PPs) were investigated. Solubility experiments were carried out to evaluate the effect of CDs on PPs aqueous solubility. Loading capacities and encapsulation efficiencies of freeze-dried inclusion complexes were determined. Moreover, photostability assays for both inclusion complexes in solution and solid state were performed. Finally, two of the most widespread phytopathogenic fungi, Fusarium oxysporum and Botrytis cinerea, were chosen to examine the antifungal activity of free and encapsulated PPs. Results showed that encapsulation in CDs significantly increased the solubility and photostability of studied PPs (by 2 to 17-fold and 2 to 44-fold, respectively). Free PPs revealed remarkable antifungal properties with isoeugenol showing the lowest half-maximal inhibitory concentration (IC50) values of mycelium growth and spore germination inhibition. Encapsulated PPs, despite their reduced antifungal activity, could be helpful to solve drawbacks such as solubility and stability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Solubility, lipophilicity and membrane permeability of some fluoroquinolone antimicrobials.

    Science.gov (United States)

    Blokhina, Svetlana V; Sharapova, Angelica V; Ol'khovich, Marina V; Volkova, Тatyana V; Perlovich, German L

    2016-10-10

    Aqueous solubility and distribution of ciprofloxacin, enrofloxacin, norfloxacin and levofloxacin antimicrobials drugs in octanol/buffer system has been measured by the isothermal saturation method using buffer solutions pH2.0 and 7.4 in the temperature range of 293.15-313.15K. Thermophysical characteristics for the compounds have been determined by the DSC method. It has been established that the solubility of levofloxacin in these buffers is higher than that of the other fluoroquinolones. HYBOT descriptors for biologically active compounds have been calculated and the impact of the donor-acceptor capacity of the molecules on drugs solubility has been studied. According to the lipophilicity parameter fluoroquinolones are ranged in the following order: enrofloxacin>levofloxacin>ciprofloxacin>norfloxacin. The thermodynamic solubility and distribution functions of the studied compounds have been obtained. The permeability coefficients of the substances through an artificial phospholipid membrane were determined. The drugs with a lower aqueous solubility were estimated to have higher distribution coefficients and membrane permeability. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. 21 CFR 73.3110 - Chlorophyllin-copper complex, oil soluble.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Chlorophyllin-copper complex, oil soluble. 73.3110...-copper complex, oil soluble. (a) Identity. The color additve is chlorophyllin-copper complex, oil soluble... complex, oil soluble (5 percent in palm oil, peanut oil, and hydrogenated peanut oil), shall conform to...

  4. Design of biodegradable nanoparticles: a novel approach to encapsulating poorly soluble phytochemical ellagic acid

    Science.gov (United States)

    Bala, I.; Bhardwaj, V.; Hariharan, S.; Sitterberg, J.; Bakowsky, U.; Kumar, M. N. V. Ravi

    2005-12-01

    Nanosizing of poorly water soluble drugs or incorporating them into nanoparticles to increase their solubility and thereby the bioavailability has become a favoured approach today. This work describes a novel method for encapsulating poorly water soluble phytochemical ellagic acid that is also sparingly soluble/insoluble in routine solvents used to prepare nanoparticles.

  5. Elevation of serum soluble E-selectin and VCAM-1 in severe asthma

    Directory of Open Access Journals (Sweden)

    Agnes Hamzaoui

    2001-01-01

    Full Text Available Objective: To investigate the significance of circulating adhesion molecules associated with leucocyteendothelial cell interactions in asthma, serum levels of soluble E (sE-selectin, soluble P (sP-selectin, soluble L (sL-selectin, and soluble vascular cell adhesion molecule-1 (sVCAM-1 were measured in mild, moderate and severe asthma.

  6. Biorefinery of microalgal soluble proteins by sequential processing and membrane filtration.

    Science.gov (United States)

    Safi, C; Olivieri, G; Campos, R P; Engelen-Smit, N; Mulder, W J; van den Broek, L A M; Sijtsma, L

    2017-02-01

    A mild biorefinery process was investigated on the microalga Nannochloropsis gaditana, to obtain an enriched fraction of water soluble proteins free from chlorophyll. After harvesting, a 100g.L-1 solution of cells was first subjected to cell disruption by either high-pressure homogenization (HPH) or enzymatic treatment (ENZ). HPH resulted in a larger release of proteins (49%) in the aqueous phase compared to the Alcalase incubation (35%). In both cases, an ultrafiltration/diafiltration (UF/DF) was then performed on the supernatant obtained from cell disruption by testing different membrane cut-off (1000kDa, 500kDa and 300kDa). After optimising the process conditions, the combination of ENZ→UF/DF ended in a larger overall yield of water soluble proteins (24.8%) in the permeate compared to the combination of HPH→UF/DF (17.4%). A gel polarization model was implemented to assess the maximum achievable concentration factor during ultrafiltration and the mass transfer coefficient related to the theoretical permeation flux rate. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Combined low dose local anesthetics and opioids versus single use ...

    African Journals Online (AJOL)

    Introduction: The combination of reduced dose of local anesthetics (LA) and highly lipid‑soluble synthetic opioids for patients undergoing transurethral surgery could reduce block duration and side‑effects. However, it remains unclear what are the most appropriate levels of low dose and the extent to which the side‑effects ...

  8. Simultaneous Rapid Determination of the Solubility and Diffusion Coefficients of a Poorly Water-Soluble Drug Based on a Novel UV Imaging System.

    Science.gov (United States)

    Lu, Yan; Li, Mingzhong

    2016-01-01

    The solubility and diffusion coefficient are two of the most important physicochemical properties of a drug compound. In practice, both have been measured separately, which is time consuming. This work utilizes a novel technique of UV imaging to determine the solubility and diffusion coefficients of poorly water-soluble drugs simultaneously. A 2-step optimal method is proposed to determine the solubility and diffusion coefficients of a poorly water-soluble pharmaceutical substance based on the Fick's second law of diffusion and UV imaging measurements. Experimental results demonstrate that the proposed method can be used to determine the solubility and diffusion coefficients of a drug with reasonable accuracy, indicating that UV imaging may provide a new opportunity to accurately measure the solubility and diffusion coefficients of a poorly water-soluble drug simultaneously and rapidly. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  9. Recovery of residual soluble protein by two-step precipitation process with concomitant COD reduction from the yeast-cultivated cheese whey.

    Science.gov (United States)

    Yadav, J S S; Yan, S; More, T T; Tyagi, R D; Surampalli, R Y

    2014-09-01

    The present study was conducted to recover the residual soluble protein after cultivation of yeast (K. marxianus) in cheese whey. Cheese whey continuous fermentation with cell recycle system was carried out at 40 °C and pH 3.5. The yeast biomass was separated from the fermented broth by centrifugation and residual soluble protein from fermented whey supernatant was precipitated by heat treatment (at 100 °C, pH 4.5 and 10 min incubation). The maximum soluble protein recovery up to 53 % was achieved at pH 4.5 with 54 % residual COD removal. However, gravity sedimentable precipitates were obtained at pH 3.5 with 47 % protein recovery. Therefore, the reactor (scale up) study was conducted at pH 3.5 with agitation, which resulted in 68 % of residual soluble protein recovery and simultaneously residual COD removal of 62 %. Further precipitation/coagulation of soluble protein was also evaluated using carboxymethylcellulose (CMC) and then two precipitation (thermal followed by CMC precipitation) processes were combined to increase the protein precipitation, which finally reached up to 81 % of total soluble protein recovery from the supernatant. This optimized process could be applied to recover the residual protein left after fermentation of cheese whey without centrifugation.

  10. Determination of Zinc Sulfide Solubility to High Temperatures

    DEFF Research Database (Denmark)

    Carolina Figueroa Murcia, Diana; Fosbøl, Philip Loldrup; Thomsen, Kaj

    2017-01-01

    A new experimental set-up and methodology for the measurement of ZnS solubility in aqueous solutions at 40, 60 and 80 °C (atmospheric pressure) is presented. The methodology implemented includes the preparation of the samples in a reduced oxygen atmosphere, particle size analysis of ZnS, quality...... control of the analytical technique and evaluation of equilibration time. ZnS solubility analyses were run for prolonged times (up to 11 days) to ensure that equilibrium conditions were met. The equilibration time was explored at three temperatures (40, 60 and 80 °C) observing small variations in the time...... required to reach the solid–liquid equilibrium at each temperature. Equilibrium was reached within 72 h. The concentration of zinc and of total sulfur were determined using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The experimental solubility data show an exponential dependency...

  11. EFFECT OF HEAT TREATMENT ON SOYBEAN PROTEIN SOLUBILITY

    Directory of Open Access Journals (Sweden)

    RODICA CĂPRIŢĂ

    2007-05-01

    Full Text Available The use of soybean products in animal feeds is limited due to the presence of antinutritional factors (ANF. Proper heat processing is required to destroy ANF naturally present in raw soybeans and to remove solvent remaining from the oil extraction process. Over and under toasting of soybean causes lower nutritional value. Excessive heat treatment causes Maillard reaction which affects the availability of lysine in particular and produces changes to the chemical structure of proteins resulting in a decrease of the nutritive value. The objective of this study was to evaluate the effect of heating time on the protein solubility. The investigation of the heating time on protein solubility in soybean meal (SBM revealed a negative correlation (r = -0.9596. Since the urease index is suitable only for detecting under processed SBM, the protein solubility is an important index for monitoring SBM quality.

  12. Development of a salt drug with improved solubility: Ethionamide nitrate

    Science.gov (United States)

    Diniz, Luan F.; Carvalho, Paulo S.; de Melo, Cristiane C.; Ellena, Javier

    2017-06-01

    To avoid drug resistance, an adequate tuberculosis treatment should include not only a first-line drug but also at least one second-line drug such as, for example, Ethionamide (ETH). However, the dissolution rate and oral absorption of ETH is highly limited by its low aqueous solubility. Considering that a salt is in general more soluble than its parent compound, herein we depicted a new supramolecular modification of ETH, an Ethionamide nitrate salt (ETHNO3). This salt is the first ETH structure that has been crystallized with four independent ionic pairs (ETH+NO3-) in the asymmetric unit. In addition to the structural study, the salt formation was also identified on the FT-IR and FT-Raman spectra. The thermal behavior of ETHNO3 was also investigated here together with its solubility profile in three dissolution media (purified water, pH 4.0 and 7.0).

  13. Effects of water-soluble humic extract and biofertilizer on development of Callophyllum brasiliense seedlings

    Directory of Open Access Journals (Sweden)

    Jader Galba Busato

    2016-06-01

    Full Text Available The objective of this work was to evaluate the effects of water-soluble humic extract (EHSA, Hortbio® biofertilizer (HORT and both compounds combination (EHSA+HORT on vegetative growth, nutrient absorption and chlorophyll levels in guanandi (Callophyllum brasiliense seedlings. Isolated and combined additions of EHSA and HORT did not affect seedlings height, number of leaves, leaf and root dry matter and leaf area during early stages of seedling growth. However, HORT and EHSA+HORT treatments increased chlorophyll levels and total N content. Addition of HORT resulted in S, Zn, Mg, Mn and Cu increases in the seedlings leaves, while ESHA application increased K, Mg, S and B. P and Ca levels were not altered by the treatments, however, addition of EHSA and EHSA+HORT reduced significantly the absorption of Cu, Fe, Mn and Zn.

  14. Method to produce water-soluble sugars from biomass using solvents containing lactones

    Energy Technology Data Exchange (ETDEWEB)

    Dumesic, James A.; Luterbacher, Jeremy S.

    2017-08-08

    A process to produce an aqueous solution of carbohydrates that contains C6-sugar-containing oligomers, C6 sugar monomers, C5-sugar-containing oligomers, C5 sugar monomers, or any combination thereof is presented. The process includes the steps of reacting biomass or a biomass-derived reactant with a solvent system including a lactone and water, and an acid catalyst. The reaction yields a product mixture containing water-soluble C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof. A solute is added to the product mixture to cause partitioning of the product mixture into an aqueous layer containing the carbohydrates and a substantially immiscible organic layer containing the lactone.

  15. Simultaneous enhancements of solubility and dissolution rate of poorly water-soluble febuxostat via salts

    Science.gov (United States)

    Zhang, Xian-Rui; Zhang, Lei

    2017-06-01

    Novel crystalline forms of febuxostat (HFEB) salts were synthesized by liquid-assisted cogrinding with 2-methylimidazole (2MI) and di-2-pyridylamine (DPA) and characterized by Hirshfeld surface analysis, IR, 1H NMR, single crystal and powder X-ray diffractions, TGA and DSC. Two new HFEB salts featured different stoichiometries: 2:1 molecular ratio in HFEB-2MI and 1:1 molecular ratio in HFEB-DPA. For HFEB-2MI salt, two HFEB molecules lost one proton forming a singly charged hydrogen carboxylate anion H(FEB)2-, which interacted with the disordered 2MI cation via the N3sbnd H3A⋯O1i (i: -x, -y, -z+1) and N4sbnd H4B⋯O1ii (ii: x, y+1, z-1) hydrogen bonds to form one-dimensional structure. For HFEB-DPA salt, one proton transferred from one HFEB to DPA, which were further connected by N4sbnd H1⋯O1 and N3sbnd H2⋯O2 hydrogen bonds to form an R22(8) ring motif. HFEB-2MI and HFEB-DPA salts exhibited increased equilibrium solubilities and intrinsic dissolution rates compared to those of HFEB in aqueous medium.

  16. ESPRIT: an automated, library-based method for mapping and soluble expression of protein domains from challenging targets.

    Science.gov (United States)

    Yumerefendi, Hayretin; Tarendeau, Franck; Mas, Philippe J; Hart, Darren J

    2010-10-01

    Expression of sufficient quantities of soluble protein for structural biology and other applications is often a very difficult task, especially when multimilligram quantities are required. In order to improve yield, solubility or crystallisability of a protein, it is common to subclone shorter genetic constructs corresponding to single- or multi-domain fragments. However, it is not always clear where domain boundaries are located, especially when working on novel targets with little or no sequence similarity to other proteins. Several methods have been described employing aspects of directed evolution to the recombinant expression of challenging proteins. These combine the construction of a random library of genetic constructs of a target with a screening or selection process to identify solubly expressing protein fragments. Here we review several datasets from the ESPRIT (Expression of Soluble Proteins by Random Incremental Truncation) technology to provide a view on its capabilities. Firstly, we demonstrate how it functions using the well-characterised NF-kappaB p50 transcription factor as a model system. Secondly, application of ESPRIT to the challenging PB2 subunit of influenza polymerase has led to several novel atomic resolution structures; here we present an overview of the screening phase of that project. Thirdly, analysis of the human kinase TBK1 is presented to show how the ESPRIT technology rapidly addresses the compatibility of challenging targets with the Escherichia coli expression system.

  17. Solubility of natural gases in water under high pressure; Solubilite des gaz naturels dans l`eau a pression elevee

    Energy Technology Data Exchange (ETDEWEB)

    Dhima, A.

    1998-10-08

    Under high pressure (up to 1200 bar) and high temperature (up to 200 deg C) petroleum reservoir conditions the hydrocarbon-water mutual solubilities may become important. Under such conditions, the prediction of hydrocarbon water solubilities is a challenge for petroleum engineers. Indeed, very few studies have been done ar pressures higher that 700 bars. New solubility data for methane, ethane, n-butane, CO{sub 2} and their mixtures in pure water were obtained at 344.25 K and from 2.5 to 100 MPa. The results agree very well with those of the literature in the case of pure hydrocarbons in water, but differ for the hydrocarbon mixtures. A rigorous thermodynamic analysis allows the elaboration of a model that combines a cubic equation of state (Peng-Robinson with k{sub ij} given in literature) with the Henry`s law approach. The (P,T) functional form of Henry`s constant is given by the Krichevsky-Kasarnovsky equation which involves two important parameters: partial molar volume at infinite dilution and Henry`s constant at the vapour pressure of water. For a given solute both parameters are only functions of temperature. A critical selection of binary solubility data for a large number of solutes has been used as a basis for a new correlation for calculating both this partial molar volume and the corresponding Henry`s constants as a function of temperature. (author) 169 refs.

  18. Cryomilling-induced solid dispersion of poor glass forming/poorly water-soluble mefenamic acid with polyvinylpyrrolidone K12.

    Science.gov (United States)

    Kang, Naewon; Lee, Jangmi; Choi, Ji Na; Mao, Chen; Lee, Eun Hee

    2015-06-01

    The effect of mechanical impact on the polymorphic transformation of mefenamic acid (MFA) and the formation of a solid dispersion of mefenamic acid, a poor glass forming/poorly-water soluble compound, with polyvinylpyrrolidone (PVP) K12 was investigated. The implication of solid dispersion formation on solubility enhancement of MFA, prepared by cryomilling, was investigated. Solid state characterization was conducted using powder X-ray diffraction (PXRD) and Fourier-transform infrared (FTIR) spectroscopy combined with crystal structure analysis. Apparent solubility of the mixtures in pH 7.4 buffer was measured. A calculation to compare the powder patterns and FTIR spectra of solid dispersions with the corresponding physical mixtures was conducted. Solid state characterization showed that (1) MFA I transformed to MFA II when pure MFA I was cryogenically milled (CM); and (2) MFA forms a solid dispersion when MFA was cryogenically milled with PVP K12. FTIR spectral analysis showed that hydrogen bonding facilitated by mechanical impact played a major role in forming solid dispersions. The apparent solubility of MFA was significantly improved by making a solid dispersion with PVP K12 via cryomilling. This study highlights the importance of cryomilling with a good hydrogen bond forming excipient as a technique to prepare solid dispersion, especially when a compound shows a poor glass forming ability and therefore, is not easy to form amorphous forms by conventional method.

  19. Impacts of Sample Preparation Methods on Solubility and Antilisterial Characteristics of Essential Oil Components in Milk

    OpenAIRE

    Chen, Huaiqiong; Davidson, P. Michael; Zhong, Qixin

    2014-01-01

    Essential oil components (EOCs) have limited water solubility and are used at much higher concentrations in complex food matrices than in growth media to inhibit pathogens. However, the correlation between solubility and activity has not been studied. The objective of this work was to characterize the solubility of EOCs in solvents and milk and correlate solubility with antilisterial activity. The solubilities of four EOCs, thymol, carvacrol, eugenol, and trans-cinnamaldehyde, in water was si...

  20. Water sorption and solubility of polyamide denture base materials.

    Science.gov (United States)

    Nguyen, Long G; Kopperud, Hilde M; Øilo, Marit

    2017-01-01

    Purpose: Some patients experience adverse reactions to poly(methyl methacrylate)-based (PMMA) dentures. Polyamide (PA) as an alternative to PMMA has, however, not been well documented with regard to water sorption and water solubility. The aim of this in vitro study was to measure water sorption and water solubility of two PA materials compared with PMMA, and to evaluate the major components released from the PA materials and the effect on hardness of the materials. Methods: Ten discs (40.0 mm diameter, 2.0 mm thick) of each material (PA: Valplast and Breflex; PMMA: SR Ivocap HIP) were prepared according to manufacturers' recommendations. The specimens were tested for water sorption and water solubility, according to a modification of ISO 20795-1:2008. Released substances were analysed by gas chromatography/mass spectrometry (GC/MS). Results: There were statistically significant differences among the materials regarding water sorption, water solubility and time to water saturation. Breflex had the highest water sorption (30.4 μg/mm(3)), followed by PMMA-material (25.8 μg/mm(3)) and Valplast (13.6 μg/mm(3)). Both PA materials had statistically significant lower water solubility than the PMMA. Both PA had a net increase in weight. Analysis by GC/MS identified release of the compound 12-aminododecanolactam from the material Valplast. No release was found from the Breflex material. Conclusions: The PA denture materials show differences in water sorption and solubility, but within the limits of the standard requirements. The PA showed a net increase in weight after long-term water sorption. The clinical implications of the findings are not elucidated.

  1. Thermodynamic Approach to Boron Nitride Nanotube Solubility and Dispersion

    Science.gov (United States)

    Tiano, A. L.; Gibbons, L.; Tsui, M.; Applin, S. I.; Silva, R.; Park, C.; Fay, C. C.

    2016-01-01

    Inadequate dispersion of nanomaterials is a critical issue that significantly limits the potential properties of nanocomposites and when overcome, will enable further enhancement of material properties. The most common methods used to improve dispersion include surface functionalization, surfactants, polymer wrapping, and sonication. Although these approaches have proven effective, they often achieve dispersion by altering the surface or structure of the nanomaterial and ultimately, their intrinsic properties. Co-solvents are commonly utilized in the polymer, paint, and art conservation industries to selectively dissolve materials. These co-solvents are utilized based on thermodynamic interaction parameters and are chosen so that the original materials are not affected. The same concept was applied to enhance the dispersion of boron nitride nanotubes (BNNTs) to facilitate the fabrication of BNNT nanocomposites. Of the solvents tested, dimethylacetamide (DMAc) exhibited the most stable, uniform dispersion of BNNTs, followed by N,N-dimethylformamide (DMF), acetone, and N-methyl-2-pyrrolidone (NMP). Utilizing the known Hansen solubility parameters of these solvents in comparison to the BNNT dispersion state, a region of good solubility was proposed. This solubility region was used to identify co-solvent systems that led to improved BNNT dispersion in poor solvents such as toluene, hexane, and ethanol. Incorporating the data from the co-solvent studies further refined the proposed solubility region. From this region, the Hansen solubility parameters for BNNTs are thought to lie at the midpoint of the solubility sphere: 16.8, 10.7, and 9.0 MPa(exp 1/2) for delta d, delta p, and delta h, respectively, with a calculated Hildebrand parameter of 21.8 MPa)exp 1/2).

  2. Successful inhibition of intracranial human glioblastoma multiforme xenograft growth via systemic adenoviral delivery of soluble endostatin and soluble vascular endothelial growth factor receptor-2: laboratory investigation.

    Science.gov (United States)

    Szentirmai, Oszkar; Baker, Cheryl H; Bullain, Szofia S; Lin, Ning; Takahashi, Masaya; Folkman, Judah; Mulligan, Richard C; Carter, Bob S

    2008-05-01

    Glioblastoma multiforme (GBM) is characterized by neovascularization, raising the question of whether angiogenic blockade may be a useful therapeutic strategy for this disease. It has been suggested, however, that, to be useful, angiogenic blockade must be persistent and at levels sufficient to overcome proangiogenic signals from tumor cells. In this report, the authors tested the hypothesis that sustained high concentrations of 2 different antiangiogenic proteins, delivered using a systemic gene therapy strategy, could inhibit the growth of established intracranial U87 human GBM xenografts in nude mice. Mice harboring established U87 intracranial tumors received intravenous injections of adenoviral vectors encoding either the extracellular domain of vascular endothelial growth factor receptor-2-Fc fusion protein (Ad-VEGFR2-Fc) alone, soluble endostatin (Ad-ES) alone, a combination of Ad-VEGFR2-Fc and Ad-ES, or immunoglobulin 1-Fc (Ad-Fc) as a control. Three weeks after treatment, magnetic resonance imaging-based determination of tumor volume showed that treatment with Ad-VEGFR2-Fc, Ad-ES, or Ad-VEGFR2-Fc in combination with Ad-ES, produced 69, 59, and 74% growth inhibition, respectively. Bioluminescent monitoring of tumor growth revealed growth inhibition in the same treatment groups to be 62, 74, and 72%, respectively. Staining with proliferating cell nuclear antigen and with terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling showed reduced tumor cell proliferation and increased apoptosis in all antiangiogenic treatment groups. These results suggest that systemic delivery and sustained production of endostatin and soluble VEGFR2 can slow intracranial glial tumor growth by both reducing cell proliferation and increasing tumor apoptosis. This work adds further support to the concept of using antiangiogenesis therapy for intracranial GBM.

  3. Successful inhibition of intracranial human glioblastoma multiforme xenograft growth via systemic adenoviral delivery of soluble endostatin and soluble vascular endothelial growth factor receptor-2

    Science.gov (United States)

    Szentirmai, Oszkar; Baker, Cheryl H.; Bullain, Szofia S.; Lin, Ning; Takahashi, Masaya; Folkman, Judah; Mulligan, Richard C.; Carter, Bob S.

    2015-01-01

    Object Glioblastoma multiforme (GBM) is characterized by neovascularization, raising the question of whether angiogenic blockade may be a useful therapeutic strategy for this disease. It has been suggested, however, that, to be useful, angiogenic blockade must be persistent and at levels sufficient to overcome proangiogenic signals from tumor cells. In this report, the authors tested the hypothesis that sustained high concentrations of 2 different antiangiogenic proteins, delivered using a systemic gene therapy strategy, could inhibit the growth of established intracranial U87 human GBM xenografts in nude mice. Methods Mice harboring established U87 intracranial tumors received intravenous injections of adenoviral vectors encoding either the extracellular domain of vascular endothelial growth factor receptor-2-Fc fusion protein (Ad-VEGFR2-Fc) alone, soluble endostatin (Ad-ES) alone, a combination of Ad-VEGFR2-Fc and Ad-ES, or immunoglobulin 1-Fc (Ad-Fc) as a control. Results Three weeks after treatment, magnetic resonance imaging-based determination of tumor volume showed that treatment with Ad-VEGFR2-Fc, Ad-ES, or Ad-VEGFR2-Fc in combination with Ad-ES, produced 69, 59, and 74% growth inhibition, respectively. Bioluminescent monitoring of tumor growth revealed growth inhibition in the same treatment groups to be 62, 74, and 72%, respectively. Staining with proliferating cell nuclear antigen and with terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling showed reduced tumor cell proliferation and increased apoptosis in all antiangiogenic treatment groups. Conclusions These results suggest that systemic delivery and sustained production of endostatin and soluble VEGFR2 can slow intracranial glial tumor growth by both reducing cell proliferation and increasing tumor apoptosis. This work adds further support to the concept of using antiangiogenesis therapy for intracranial GBM. PMID:18447716

  4. Poly(trimethylsilylcyclooctatetraene): A soluble conjugated polyacetylene via olefin metathesis

    Energy Technology Data Exchange (ETDEWEB)

    Ginsburg, E.J.; Gorman, C.B.; Grubbs, R.H.; Marder, S.R. (California Institute of Technology, Pasadena (USA))

    1989-09-13

    highly conjugated polymers, such as polyacetylene, polythiophene, and poly(p-phenylene vinylene), have been the subject of intensive research due to their intriguing optical and electronic properties. These parent systems are highly desirable for experimental and theoretical studies due to their simplicity. Their intractability, however, has made characterization an arduous task, and insolubility has severely limited their applications. Researchers have successfully circumvented these obstacles by synthesizing soluble alkyl- and alkoxy-substituted polythiphenes and poly(p-phenylene vinylenes). Analogous soluble highly conjugated polyacetylene derivatives have proven more elusive. The authors report here the synthesis of such a polymer using ring-opening metathesis polymerization (ROMP).

  5. Water-soluble pentagonal-prismatic titanium-oxo clusters

    OpenAIRE

    Zhang, Guanyun; Liu, Caiyun; Long, De-Liang; Cronin, Leroy; Tung, Chen-Ho; Wang, Yifeng

    2016-01-01

    By using solubility control to crystallize the prenucleation clusters of hydrosol, a family of titanium-oxo clusters possessing the {Ti18O27} core in which the 18 Ti(IV)-ions are uniquely connected with μ-oxo ligands into a triple-decked pentagonal prism was obtained. The cluster cores are wrapped by external sulfate and aqua ligands, showing good solubilities and stabilities in a variety of solvents including acetonitrile and water and allowing their solution chemistry being studied by means...

  6. Solubility of anthracene and anthraquinone in cyclohexanone + carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.J. (National Chung-Hsing Univ., Taichung (Taiwan, Province of China). Dept. of Chemical Engineering)

    1994-10-01

    In the processing of an anthracene oil fraction from coal tar, a mixture of anthracene and anthraquinone is required to be separated to obtain products of high purity. The solubilities of anthracene and anthraquinone were measured in cyclohexanone + carbon dioxide as a function of the temperature and pressure of carbon dioxide at 291, 300, and 313 K and from 1.8--12.4 MPa. Average equilibrium solubilities and recoveries of both solids increased with increasing normalized concentration and pressure. The average separation factor of anthracene to anthraquinone, due to the effect of the mixed solvent, was 2.88 [+-] 1.91.

  7. Synthesis gas solubility in Fischer-Tropsch slurry: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Chao, K.C.; Lin, H.M.

    1988-01-01

    The objective is to investigate the phase equilibrium behavior of synthesis gases and products in a Fischer-Tropsch slurry reactor. A semi-flow apparatus has been designed and constructed for this purpose. Measurements have been made for hydrogen, cabon monoxide, methane, ethane, ethylene, and carbon dioxide in a heavy n-paraffin at temperatures from 100 to 300)degree)C and pressures 10 to 50 atm. Three n-paraffin waxes: n-eicosane (n-C/sub 20/), n-octacosane )n-C/sub 28/), and n-hexatriacontane (n-C/sub 36/), were studied to model the industrial wax. Solubility of synthesis gas mixtures of H/sub 2/ and CO in n-C/sub 28/ was also determined at two temperatures (200 and 300)degree)C) for each of three gas compositions (40.01, 50.01, and 66.64 mol%) of hydrogen). Measurements were extended to investigate the gas solubility in two industrial Fischer-Tropsch waxes: Mobilwax and SASOL wax. Observed solubility increases in the order: H/sub 2/, CO, CH/sub 4/, CO/sub 2/, C/sub 2/H/sub 4/, C/sub 2/H/sub 6/, at a given temperature pressure, and in the same solvent. Solubility increases with increasing pressure for all the gases. Lighter gases H/sub 2/ and CO show increased solubility with increasing temperature, while the heavier gases CO/sub 2/, ethane, and ethylene show decreased solubility with increasing temperature. The solubility of methane, the intermediate gas, changes little with temperature, and shows a shallow minimum at about 200)degrees)C or somewhat above. Henry's constant and partial molal volume of the gas solute at infinite dilution are determinedfrom the gas solubility data. A correlation is developed from the experimental data in the form on an equation of state. A computer program has been prepared to implement the correlation. 19 refs., 66 figs., 39 tabs.

  8. Rocky core solubility in Jupiter and giant exoplanets.

    Science.gov (United States)

    Wilson, Hugh F; Militzer, Burkhard

    2012-03-16

    Gas giants are believed to form by the accretion of hydrogen-helium gas around an initial protocore of rock and ice. The question of whether the rocky parts of the core dissolve into the fluid H-He layers following formation has significant implications for planetary structure and evolution. Here we use ab initio calculations to study rock solubility in fluid hydrogen, choosing MgO as a representative example of planetary rocky materials, and find MgO to be highly soluble in H for temperatures in excess of approximately 10,000 K, implying the potential for significant redistribution of rocky core material in Jupiter and larger exoplanets.

  9. Soluble fractalkine in the plasma of fibromyalgia patients

    Directory of Open Access Journals (Sweden)

    JUAN J. GARCIA

    2014-12-01

    Full Text Available Fibromyalgia is a form of non-articular rheumatism in which inflammatory cytokines seem to be involved. However, there is still no analytical specific diagnostic criterion for this disease. The aim was to examine a possible role of fractalkine as a biomarker in fibromyalgia. Plasma levels of soluble fractalkine were compared between women diagnosed with fibromyalgia (n=17 and healthy women (n=10 as controls. Fractalkine released by monocytes was also evaluated. Fibromyalgia patients showed lower plasma fractalkine than healthy women. Since most inflammatory pathologies show elevated plasma levels of soluble fractalkine, the results may contribute towards a differential diagnosis for fibromyalgia.

  10. Binary systems solubilities of inorganic and organic compounds

    CERN Document Server

    Stephen, H

    1963-01-01

    Solubilities of Inorganic and Organic Compounds, Volume 1: Binary Systems, Part 1 is part of an approximately 5,500-page manual containing a selection from the International Chemical Literature on the Solubilities of Elements, Inorganic Compounds, Metallo-organic and Organic Compounds in Binary, Ternary and Multi-component Systems. A careful survey of the literature in all languages by a panel of scientists specially appointed for the task by the U.S.S.R. Academy of Sciences, Moscow, has made the compilation of this work possible. The complete English edition in five separately bound volumes w

  11. Fire Resistance of Wood Impregnated with Soluble Alkaline Silicates

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Giudice

    2007-01-01

    Full Text Available The aim of this paper is to determine the fire performance of wood panels (Araucaria angustifolia impregnated with soluble alkaline silicates. Commercial silicates based on sodium and potassium with 2.5/1.0 and 3.0/1.0 silica/alkali molar ratios were selected; solutions and glasses were previously characterized. Experimental panels were tested in a limiting oxygen chamber and in a two-foot tunnel. Results displayed a high fire-retardant efficiency using some soluble silicates.

  12. Soluble and cell surface receptors for tumor necrosis factor

    DEFF Research Database (Denmark)

    Wallach, D; Engelmann, H; Nophar, Y

    1991-01-01

    . The intracellular domains of the two receptors differ in structure, suggesting that they mediate different activities. Their extracellular domains, however, are structurally related. Both contain cysteine-rich repeats which are homologous to repeated structures found in the extracellular domains of the nerve growth...... in certain pathological situations. Release of the soluble receptors from the cells seems to occur by proteolytic cleavage of the cell surface forms and appears to be a way of down-regulating the cell response to TNF. Because of their ability to bind TNF, the soluble receptors exert an inhibitory effect...

  13. Improvement in aqueous solubility achieved via small molecular changes.

    Science.gov (United States)

    Walker, Michael A

    2017-12-01

    Overcoming poor solubility is a significant issue in drug discovery. The most common solution is to replace carbon atoms with polar heteroatoms such as N and O or by attaching a solubilizing appendage. This approach can lead to other issues such as poor activity and PK or the increased risk for toxicity. However, there are more subtle structural changes which can be employed that lead to an increase in solubility. These include, excising hydrophobic groups which do not efficiently contribute to binding, modifying stereo- and regiochemistry, increasing or decreasing the degree of unsaturation or adding small hydrophobic groups such as fluorine or methyl. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Purification and characterization of a soluble calnexin from human placenta

    DEFF Research Database (Denmark)

    Olsen, Dorthe T; Peng, Li; Træholt, Sofie D

    2013-01-01

    (sCnx) was consistently identified in a separate ion exchange chromatography peak. The sCnx was further purified and characterised. This showed that the protein had been cleaved after residue 472 (between Gln and Met), thus liberating it from the transmembrane and cytoplasmic parts of Cnx......Calreticulin (Crt) and calnexin (Cnx) are homologous endoplasmic reticulum (ER) chaperones involved in protein folding and quality control. Crt is a soluble ER luminal Mr 46 kDa protein and Cnx is a Mr 67kDa ER membrane protein. During purification of Crt from human placenta a soluble form of Cnx...

  15. Redox Active Polymers as Soluble Nanomaterials for Energy Storage.

    Science.gov (United States)

    Burgess, Mark; Moore, Jeffrey S; Rodríguez-López, Joaquín

    2016-11-15

    It is an exciting time for exploring the synergism between the chemical and dimensional properties of redox nanomaterials for addressing the manifold performance demands faced by energy storage technologies. The call for widespread adoption of alternative energy sources requires the combination of emerging chemical concepts with redesigned battery formats. Our groups are interested in the development and implementation of a new strategy for nonaqueous flow batteries (NRFBs) for grid energy storage. Our motivation is to solve major challenges in NRFBs, such as the lack of membranes that simultaneously allow fast ion transport while minimizing redox active species crossover between anolyte (negative electrolyte) and catholyte (positive electrolyte) compartments. This pervasive crossover leads to deleterious capacity fade and materials underutilization. In this Account, we highlight redox active polymers (RAPs) and related polymer colloids as soluble nanoscopic energy storing units that enable the simple but powerful size-exclusion concept for NRFBs. Crossover of the redox component is suppressed by matching high molecular weight RAPs with simple and inexpensive nanoporous commercial separators. In contrast to the vast literature on the redox chemistry of electrode-confined polymer films, studies on the electrochemistry of solubilized RAPs are incipient. This is due in part to challenges in finding suitable solvents that enable systematic studies on high polymers. Here, viologen-, ferrocene- and nitrostyrene-based polymers in various formats exhibit properties that make amenable their electrochemical exploration as solution-phase redox couples. A main finding is that RAP solutions store energy efficiently and reversibly while offering chemical modularity and size versatility. Beyond the practicality toward their use in NRFBs, the fundamental electrochemistry exhibited by RAPs is fascinating, showing clear distinctions in behavior from that of small molecules. Whereas

  16. Alleviation of environmental risks associated with severely contaminated mine tailings using amendments: Modeling of trace element speciation, solubility, and plant accumulation.

    Science.gov (United States)

    Pardo, Tania; Bes, Cleménce; Bernal, Maria Pilar; Clemente, Rafael

    2016-11-01

    Tailings are considered one of the most relevant sources of contamination associated with mining activities. Phytostabilization of mine spoils may need the application of the adequate combination of amendments to facilitate plant establishment and reduce their environmental impact. Two pot experiments were set up to assess the capability of 2 inorganic materials (calcium carbonate and a red mud derivate, ViroBind TM ), alone or in combination with organic amendments, for the stabilization of highly acidic trace element-contaminated mine tailings using Atriplex halimus. The effects of the treatments on tailings and porewater physico-chemical properties and trace-element accumulation by the plants, as well as the processes governing trace elements speciation and solubility in soil solution and their bioavailability were modeled. The application of the amendments increased tailings pH and decreased (>99%) trace elements solubility in porewater, but also changed the speciation of soluble Cd, Cu, and Pb. All the treatments made A. halimus growth in the tailings possible; organic amendments increased plant biomass and nutritional status, and reduced trace-element accumulation in the plants. Tailings amendments modified trace-element speciation in porewater (favoring the formation of chlorides and/or organo-metallic forms) and their solubility and plant uptake, which were found to be mainly governed by tailing/porewater pH, electrical conductivity, and organic carbon content, as well as soluble/available trace-element concentrations. Environ Toxicol Chem 2016;35:2874-2884. © 2016 SETAC. © 2016 SETAC.

  17. PLUTONIUM SOLUBILITY IN SIMULATED SAVANNAH RIVER SITE WASTE SOLUTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Rudisill, T.; Hobbs, D.; Edwards, T.

    2010-09-27

    To address the accelerated disposition of the supernate and salt portions of Savannah River Site (SRS) high level waste (HLW), solubility experiments were performed to develop a predictive capability for plutonium (Pu) solubility. A statistically designed experiment was used to measure the solubility of Pu in simulated solutions with salt concentrations and temperatures which bounded those observed in SRS HLW solutions. Constituents of the simulated waste solutions included: hydroxide (OH{sup -}), aluminate (Al(OH){sub 4}{sup -}), sulfate (SO{sub 4}{sup 2-}), carbonate (CO{sub 3}{sup 2-}), nitrate (NO{sub 3}{sup -}), and nitrite (NO{sub 2}{sup -}) anions. Each anion was added to the waste solution in the sodium form. The solubilities were measured at 25 and 80 C. Five sets of samples were analyzed over a six month period and a partial sample set was analyzed after nominally fifteen months of equilibration. No discernable time dependence of the measured Pu concentrations was observed except for two salt solutions equilibrated at 80 C which contained OH{sup -} concentrations >5 mol/L. In these solutions, the Pu solubility increased with time. This observation was attributed to the air oxidation of a portion of the Pu from Pu(IV) to the more soluble Pu(V) or Pu(VI) valence states. A data driven approach was subsequently used to develop a modified response surface model for Pu solubility. Solubility data from this study and historical data from the literature were used to fit the model. The model predicted the Pu solubility of the solutions from this study within the 95% confidence interval for individual predictions and the analysis of variance indicated no statistically significant lack of fit. The Savannah River National Laboratory (SRNL) model was compared with predicted values from the Aqueous Electrolyte (AQ) model developed by OLI Systems, Inc. and a solubility prediction equation developed by Delegard and Gallagher for Hanford tank waste. The agreement between

  18. The Improvement of Answering Questions Skills in Solubility and Solubility Product Concept by Problem Solving Learning Model

    OpenAIRE

    marthandila, ria; Fadiawati, Noor; diawati, chansyanah

    2012-01-01

    The aim of this research is to describe the effectiveness of problem solving learning model in solubility and solubility product concept to enhance skill in answering questions. Students who became the subject of this research was XI grade of Science 1 Batanghari Senior High School in Batanghari Academic Year 2011/2012. This research used the pre-experimental method and one group pretest-posttest design. The effectiveness of problem solving learning model was determined based on the ave...

  19. IUPAC-NIST Solubility Data Series. 98. Solubility of Polycyclic Aromatic Hydrocarbons in Pure and Organic Solvent Mixtures: Revised and Updated. Part 2. Ternary Solvent Mixtures

    Science.gov (United States)

    Acree, William E.

    2013-03-01

    This work updates Vols. 54, 58, and 59 in the IUPAC Solubility Data Series and presents solubility data for polycyclic aromatic hydrocarbon solutes dissolved in ternary organic solvent mixtures. Published solubility data for anthracene, phenanthrene, and pyrene that appeared in the primary literature between 1995 to the end of 2011 are compiled and critically evaluated. Experimental solubility data for 119 different solute-ternary solvent systems are included in the volume. Solubility data published prior to 1995 were contained in three earlier volumes (Vols. 54, 58, and 59) and are not repeated here.

  20. IUPAC-NIST Solubility Data Series. 98. Solubility of Polycyclic Aromatic Hydrocarbons in Pure and Organic Solvent Mixtures--Revised and Updated. Part 3. Neat Organic Solvents

    Science.gov (United States)

    Acree, William E.

    2013-03-01

    This work updates Vols. 54, 58, and 59 in the IUPAC Solubility Data Series and presents solubility data for polycyclic aromatic hydrocarbon solutes dissolved in neat organic solvents. Published solubility data for acenaphthene, anthracene, biphenyl, carbazole, dibenzofuran, dibenzothiophene, fluoranthene, fluorene, naphthalene, phenanthrene, phenothiazine, pyrene, thianthrene, and xanthene that appeared in the primary literature from 1995 to the end of 2011 are compiled and critically evaluated. Experimental solubility data for more than 550 different solute-organic solvent systems are included. Solubility data published prior to 1995 were contained in three earlier volumes (Vols. 54, 58, and 59) and are not repeated in this volume.

  1. IUPAC-NIST Solubility Data Series. 98. Solubility of Polycyclic Aromatic Hydrocarbons in Pure and Organic Solvent Mixtures: Revised and Updated. Part 1. Binary Solvent Mixtures

    Science.gov (United States)

    Acree, William E.

    2013-03-01

    This work updates Vols. 54, 58, and 59 in the IUPAC Solubility Data Series and presents solubility data for polycyclic aromatic hydrocarbon solutes dissolved in binary organic solvent mixtures. Published solubility data for anthracene, naphthalene, phenanthrene, phenothiazine, and pyrene that appeared in the primary literature between 1995 to the end of 2011 are compiled and critically evaluated. Experimental solubility data for 360 different solute-binary solvent systems are included in the volume. Solubility data published prior to 1995 were contained in three earlier volumes (Vols. 54, 58, and 59) and are not repeated in this volume.

  2. Enhancement of Aqueous Solubility and Oral Bioavailability of ...

    African Journals Online (AJOL)

    Methods: Complexation of NM with β-CD in 1:1.5 molar ratio was carried out by solvent evaporation, freeze-drying and kneading methods. The complexes were characterized by Fourier transform infrared spectroscopy (FTIR). The in vitro solubility of the pure drug as well as that of the complexes was evaluated using USP ...

  3. Solubility of phenolic compounds in water, organic and supercritical solvents

    OpenAIRE

    Queimada, António; Mota, Fátima; Direito, Filipe; Pinho, Simão; Macedo, Eugénia A.

    2009-01-01

    Phenolic compounds represent a class of important chemicals with both biological and industrial importance. Their production, either by chemical synthesis or extraction from different biological media requires the adequate knowledge of phase equilibria. Particularly, the solubility in aqueous systems organic and supercritical solvents are fundamental for a better design of separation and purification processes.

  4. Improved solubility of TEV protease by directed evolution.

    Science.gov (United States)

    van den Berg, Susanne; Löfdahl, Per-Ake; Härd, Torleif; Berglund, Helena

    2006-02-10

    The efficiency and high specificity of tobacco etch virus (TEV) protease has made it widely used for cleavage of recombinant fusion proteins. However, the production of TEV protease in E. coli is hampered by low solubility. We have subjected the gene encoding TEV protease to directed evolution to improve the yield of soluble protein. Libraries of mutated genes obtained by error-prone PCR and gene shuffling were introduced into the Gateway cloning system for facilitated transfer between vectors for screening, purification, or other applications. Fluorescence based in vivo solubility screening was carried out by cloning the libraries into a plasmid encoding a C-terminal GFP fusion. Mutant genes giving rise to high GFP fluorescence intensity indicating high levels of soluble TEV-GFP were subsequently transferred to a vector providing a C-terminal histidine tag for expression, purification, and activity tests of mutated TEV. We identified a mutant, TEV(SH), in which three amino acid substitutions result in a five-fold increase in the yield of purified protease with retained activity.

  5. Plasma concentrations of water.soluble vitamins in metabolic ...

    African Journals Online (AJOL)

    Context: Vitamins B1 (thiamine), B3 (niacin), B6 (pyridoxine), and C (ascorbic acid) are vital for energy, carbohydrate, lipid, and amino acid metabolism and in the regulation of the cellular redox state. Some studies have associated low levels of water.soluble vitamins with metabolic syndrome and its various components.

  6. Effects of rare earth elements on callus growth, soluble protein ...

    African Journals Online (AJOL)

    The effects of lanthanum nitrate (La3+) and cerium nitrate (Ce4+) on Echinacea angustifolia callus growth and subculture were studied by the measurement of callus fresh weight, dry weight and time-course curve. The effects of La3+ on soluble protein content, peroxidase activity and shoot differentiation of callus were also ...

  7. Applications of SSAFT EOS for determination of the solubilities of ...

    African Journals Online (AJOL)

    Applications of SSAFT EOS for determination of the solubilities of solid compounds in supercritical CO 2 . ... Using statistical thermodynamics such as Simplified SAFT equation of state (SSAFTEoS) for estimating phase equilibrium and fluid properties of different materials have been used widely. SSAFT EoS has been ...

  8. Solubilities of ferrocene and acetylferrocene in supercritical carbon dioxide

    DEFF Research Database (Denmark)

    Kazemi, Somayeh; Belandria, Veronica; Janssen, Nico

    2012-01-01

    In this work, the solubilities of ferrocene and acetylferrocene in supercritical carbon dioxide (scCO2) were measured using an analytical method in a quasi-flow apparatus. High-performance liquid chromatography was applied through an online sampling procedure to determine the concentration...

  9. Enhancement of solubility and dissolution rate of atorvastatin ...

    African Journals Online (AJOL)

    22. Padrela L, Rodrigues MA, Velaga SP, Matos HA,. Azevedo EG. Formation of indomethacin–saccharin cocrystals using supercritical fluid technology. Eur J. Pharm Sci 2009; 38: 9-17. 23. Blagden N, Matas M, Gavan PT, York P. Crystal engineering of active pharmaceutical ingredients to improve solubility and dissolution ...

  10. Water-Soluble Gold Nanoparticles Protected by Fluorinated Amphiphilic Thiolates

    NARCIS (Netherlands)

    Gentilini, Cristina; Evangelista, Fabrizio; Rudolf, Petra; Franchi, Paola; Lucarini, Marco; Pasquato, Lucia

    2008-01-01

    The preparation and the properties of gold nanoparticles (Au NPs) protected by perfluorinated amphiphiles are described. The thiols were devised to form a perfluorinated region close to the gold surface and to have a hydrophilic portion in contact with the bulk solvent to impart solubility in water.

  11. Urinary Soluble CD163 in Active Renal Vasculitis

    NARCIS (Netherlands)

    O'Reilly, Vincent P.; Wong, Limy; Kennedy, Claire; Elliott, Louise A.; O'Meachair, Shane; Coughlan, Alice Marie; O'Brien, Eoin C.; Ryan, Michelle M.; Sandoval, Diego; Connolly, Emma; Dekkema, Gerjan J.; Lau, Jiaying; Abdulahad, Wayel H.; Heeringa, Peter; Buckley, Colm; O'Brien, Cathal; Finn, Stephen; Cohen, Clemens D.; Lindemeyer, Maja T.; Hickey, Fionnuala B.; O'Hara, Paul V.; Feighery, Conleth; Moran, Sarah M.; Mellotte, George; Clarkson, Michael R.; Dorman, Anthony J.; Murray, Patrick T.; Little, Mark A.; Sanders, Johannes

    A specific biomarker that can separate active renal vasculitis from other causes of renal dysfunction is lacking, with a kidney biopsy often being required. Soluble CD163 (sCD163), shed by monocytes and macrophages, has been reported as a potential biomarker in diseases associated with excessive

  12. Viscosity and Electrical Conductivity of Concentrated Solutions of Soluble Coffee

    Czech Academy of Sciences Publication Activity Database

    Sobolík, Václav; Žitný, R.; Tovčigrečko, Valentin; Delgado, M.; Allaf, K.

    2002-01-01

    Roč. 51, č. 2 (2002), s. 93-98 ISSN 0260-8774 Institutional research plan: CEZ:AV0Z4072921; CEZ:MSM 212200008 Keywords : coffee extract * soluble coffee * viscosity Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.085, year: 2002

  13. Plasma concentrations of water-soluble vitamins in metabolic ...

    African Journals Online (AJOL)

    2012-01-21

    Jan 21, 2012 ... levels of water-soluble vitamins with metabolic syndrome and its various components. Aims: This study aims to determine the plasma concentrations of vitamins B1, B3, B6, and C in Nigerians with metabolic syndrome and in healthy controls. Settings and Design: One-hundred subjects with metabolic ...

  14. Synthesis and characterization of water-soluble carbon nanotubes ...

    Indian Academy of Sciences (India)

    Carbon nanotubes (CNT) has been synthesized by pyrolysing mustard oil using an oil lamp. It was made water-soluble (wsCNT) through oxidative treatment by dilute nitric acid and was characterized by SEM, AFM, XRD, Raman and FTIR spectroscopy. The synthesized wsCNT showed the presence of several junctions and ...

  15. Solubility of uranous sulfate in aqueous sulfuric acid solution

    Science.gov (United States)

    Suzuki, Shigeru; Hirono, Shuichiro; Awakura, Yasuhiro; Majima, Hiroshi

    1990-10-01

    To provide important thermodynamic data for use in uranium hydrometallurgy, solubilities of uranous sulfate were determined as a function of free acid concentration and temperature. Two sets of experiments were performed in this study. One set was the precipitation experiments of uranous sulfate crystals, in which concentrated uranous sulfate solution was mixed with sulfuric acid solution of suitable concentration. The other set was the dissolution experiments of uranous sulfate crystals in aqueous sulfuric acid solutions. It is noteworthy that good agreement exists between the solubilities determined by the two methods. At elevated temperatures, say, 363 K, the presence of free sulfuric acid is required to avoid precipitation of uranous hydroxide resulting from the hydrolysis of uranous sulfate. Generally speaking, however, an increase in free sulfuric acid concentration results in a slight decrease in uranous sulfate solubility. The elevation of solution temperature causes a decrease in solubility of uranous sulfate. It should be noted that the solid uranous sulfates equilibrated with saturated solutions at 298 K were U(SO4)2 2H2O in dilute sulfuric acid solution and U(SO4)2 4H2O in concentrated sulfuric acid solution, while those at 333 K and 363 K were mainly U(SO4)2 4H2O.

  16. Highly Active Water-Soluble Olefin Metathesis Catalyst

    OpenAIRE

    Hong, Soon Hyeok; Grubbs, Robert H

    2006-01-01

    A novel water-soluble ruthenium olefin metathesis catalyst supported by a poly(ethylene glycol) conjugated saturated 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene ligand is reported. The catalyst displays improved activity in ring-opening metathesis polymerization, ring-closing metathesis, and cross-metathesis reactions in aqueous media.

  17. Study of the soluble lens proteins from different amphibian species

    NARCIS (Netherlands)

    Brahma, S.K.; Doorenmaalen, W.J. van

    Soluble lens proteins from five species of amphibia have been studied by zone electrophoresis and other immunochemical methods. Their patterns, as revealed by electrophoresis, do not differ markedly though the numbers of bands and subunits vary. The γ-crystallin appears to be the predominant lens

  18. Study on soluble expression of glutamate dehydrogenase from tea ...

    African Journals Online (AJOL)

    Yomi

    2012-03-20

    Mar 20, 2012 ... Glutamate dehydrogenase (GDH; EC1.4.1.2) catalyses the reversible amination of 2-oxoglutarate for the synthesis of glutamate using ... CsGDH2 was predominantly found in insoluble bodies and no soluble protein was detected by either .... phosphatase (TAP) to remove the 50 cap structure from intact full-.

  19. Emulsion properties of algae soluble protein isolate from Tetraselmis sp.

    NARCIS (Netherlands)

    Schwenzfeier, A.; Helbig, A.; Wierenga, P.A.; Gruppen, H.

    2013-01-01

    To study possible applications of microalgae proteins in foods, a colourless, protein-rich fraction was isolated from Tetraselmis sp. In the present study the emulsion properties of this algae soluble protein isolate (ASPI) were investigated. Droplet size and droplet aggregation of ASPI stabilized

  20. Water-soluble diphosphadiazacyclooctanes as ligands for aqueous organometallic catalysis

    KAUST Repository

    Boulanger, Jérôme

    2012-12-01

    Two new water-soluble diphosphacyclooctanes been synthesized and characterized by NMR and surface tension measurements. Both phosphanes proved to coordinate rhodium in a very selective way as well-defined bidentates were obtained. When used in Rh-catalyzed hydroformylation of terminal alkenes, both ligands positively impacted the reaction chemoselectivity. © 2012 Elsevier B.V.

  1. Spectrophotometry and solubility properties of nickel and vanadyl porphyrin complexes

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, D.H.; Swahn, I.D. (Univ. of Maryland, College Park (USA)); Hambright, P. (Howard Univ., Washington, DC (USA))

    Spectrophotometric standards of purified synthetic Ni{sup II} and V{sup IV} complexes with etioporphyrin-I and octaethylporphyrin structures have been evaluated. Extinction coefficients, and their solvent dependence, were measured with a diode array spectrophotometer. Metalloporphyrin absorption bands (ca. 550 nm for the Ni{sup II} and ca. 570 nm for the V{sup IV}O complexes) obeyed Beer's law with a relative precision of 2% within a 0.3-10 {mu}g/ml concentration range in ethyl acetate and 1-10 {mu}g/ml range in methylene chloride. Nonlinear behavior was found to arise at concentrations above 30 {mu}g/ml in 1,2-dichloroethane. Precision of the metalloporphyrin extinction coefficient was improved significantly using a baseline correction method. Accuracy depends upon proper baseline definition. A feasibility study was performed to estimate both etio-I metalloporphyrin and octaethylmetalloporphyrin solubility equilibrated at 24{degree}C. Solubility was found to maximize in chlorinated solvents. The solubility maximum among the solvents tested was found to correspond to a solubility parameter of 9.5 for the Ni or VO porphyrins.

  2. Growth and yield responses of cowpea genotypes to soluble and ...

    African Journals Online (AJOL)

    Growth and yield responses of cowpea genotypes to soluble and rock P fertilizers on acid, highly weathered soil from humid tropical West Africa. Grace ADUSEI 1*, Thomas GAISER 1, Ousmane BOUKAR 2 and Christian FATOKUN 3. 1University of Bonn, Inst. Crop Sci. and Res. Conserv. (INRES), Katzenburgweg 5.

  3. Soluble TWEAK and Cardiovascular Morbidity and Mortality in ...

    African Journals Online (AJOL)

    Introduction: Cardiovascular disease (CVD) is a major cause of morbidity and mortality in chronic kidney patients (CKD). The aim of this study was to demonstrate the role of soluble tumor necrosis factor (TNF) weak inducer of apoptosis (sTWEAK) as a marker of cardiovascular morbidity and mortality in CKD patients.

  4. Liquid Motion Lamp: A Learning-Cycle Approach to Solubility

    Science.gov (United States)

    Brown, Sherri L.; Votaw, Nikki L.

    2008-01-01

    The abstract concepts of density and solubility are often difficult for middle-grade students and should be taught within several contexts to provide multiple experiences with the phenomena. To authenticate the learning of these concepts, this article provides instructional guidelines for constructing a liquid motion lamp to engage students in…

  5. Solubility determination from clear points upon solvent addition

    NARCIS (Netherlands)

    Reus, M.A.; Heijden, A.E.D.M. van der; Horst, J.H. ter

    2015-01-01

    A method is described for determining the solubility of multicomponent crystalline compounds from clear points upon sample dilution at a constant temperature. Clear points are established by continuously adding a solvent mixture to a suspension of known composition until a clear solution appears.

  6. Seasonal and genotypic variation of water-soluble polysaccharide ...

    African Journals Online (AJOL)

    Cyclocarya paliurus (Batal) Iljinskaja is an important medicinal woody plant due to numerous bioactive natural products in its leaves. As an important bioactive natural product, water-soluble polysaccharides (WSP) in leaves of C. paliurus possess diverse biological activities, such as hypoglycemic, anticancer and ...

  7. Balance study on sheep fed with beet molasses solubles

    African Journals Online (AJOL)

    bDepartment of Animal Physiology, Warsaw Agricultural University,. Warsaw, Poland. "To whom correspondence should be addressed. A balance study was carried out to investigate digestibility and retention of major nutrients in wethers fed rations in which condensed beet molasses solubles (CBS)formed 27% of the.

  8. Effect of varying temperature on growth, morphology and soluble ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... soluble protein content of PY79 (wild type) and div mutant strains (IA197, IA292, IA314, IA315) was ... Also protein content decreases at sporulation stages. Hence div-mutations are multifaceted mutations which cause effects on cell morphology, sporulation and ..... Exposure of cells to increased tem-.

  9. Bioremediation prospects of fungi isolated from water soluble ...

    African Journals Online (AJOL)

    Bioremediation prospects of fungi isolated from water soluble fraction of crude oil samples. ... the level of pH, EC and TDS. The ability of the fungi to adapt to these conditions indicates their potential as a tool for bioremediation of crude oil polluted water. Keywords: Bioremediation, Crude Oil, Fungi, Polluted Water, Potential.

  10. A study on the solubility of Frangula emodin

    OpenAIRE

    Mizzi, Martina; Duca, Deborah; Farrugia, Claude; Eighth National Chemistry Symposium

    2015-01-01

    Emodin (1,3,8‐trihydroxy‐6‐methyl‐anthraquinone) is a kind of anthraquinone derived from Frangula alnus. This research study describes how its solubility varies in acetonitrile, methanol, ethanol and sodium hydroxide. The physicochemical properties of emodin were also analysed through particle size, bulk density, tapped density, angle of repose and wettability measurements.

  11. Functional properties and Solubility of date seed proteins as ...

    African Journals Online (AJOL)

    Med ali

    2013-03-06

    Mar 6, 2013 ... This study is a contribution to give value addition to date palm seeds by extracting an enriched fibro- protein fraction (DSFPE) and to examine the effect of pH on some of its functional properties. For this purpose, DSFPE was prepared from water soluble extracts of defatted Deglet Nour and Allig seeds and.

  12. SYNTHESIS AND PROPERTIES OF STERICALLY HINDERED WATER SOLUBLE PORPHYRINE

    Directory of Open Access Journals (Sweden)

    Yu. V. Ishkov

    2014-12-01

    Full Text Available 5,10,15,20-(2-methoxy-3-quinolinylporphyrine, which was a mixture of atropisomers, was obtained by condensation of 2-methoxyquinoline-3-carbaldehyde with pyrrole in propionic acid. Quaternization of nitrogen atoms of peripheric substituents in this compound lead to water soluble sterically hindered porphyrine.

  13. Fire Resistance of Wood Impregnated with Soluble Alkaline Silicates

    OpenAIRE

    Andrea Marisa Pereyra; Carlos Alberto Giudice

    2007-01-01

    The aim of this paper is to determine the fire performance of wood panels (Araucaria angustifolia) impregnated with soluble alkaline silicates. Commercial silicates based on sodium and potassium with 2.5/1.0 and 3.0/1.0 silica/alkali molar ratios were selected; solutions and glasses ...

  14. Poorly soluble cobalt oxide particles trigger genotoxicity via multiple pathways.

    Science.gov (United States)

    Uboldi, Chiara; Orsière, Thierry; Darolles, Carine; Aloin, Valérie; Tassistro, Virginie; George, Isabelle; Malard, Véronique

    2016-02-03

    Poorly soluble cobalt (II, III) oxide particles (Co3O4P) are believed to induce in vitro cytotoxic effects via a Trojan-horse mechanism. Once internalized into lysosomal and acidic intracellular compartments, Co3O4P slowly release a low amount of cobalt ions (Co(2+)) that impair the viability of in vitro cultures. In this study, we focused on the genotoxic potential of Co3O4P by performing a comprehensive investigation of the DNA damage exerted in BEAS-2B human bronchial epithelial cells. Our results demonstrate that poorly soluble Co3O4P enhanced the formation of micronuclei in binucleated cells. Moreover, by comet assay we showed that Co3O4P induced primary and oxidative DNA damage, and by scoring the formation of γ-H2Ax foci, we demonstrated that Co3O4P also generated double DNA strand breaks. By comparing the effects exerted by poorly soluble Co3O4P with those obtained in the presence of soluble cobalt chloride (CoCl2), we demonstrated that the genotoxic effects of Co3O4P are not simply due to the released Co(2+) but are induced by the particles themselves, as genotoxicity is observed at very low Co3O4P concentrations.

  15. Synthesis and characterization of water-soluble carbon nanotubes ...

    Indian Academy of Sciences (India)

    Abstract. Carbon nanotubes (CNT) has been synthesized by pyrolysing mustard oil using an oil lamp. It was made water-soluble (wsCNT) through oxidative treatment by dilute nitric acid and was characterized by SEM, AFM, XRD, Raman and FTIR spec- troscopy. The synthesized wsCNT showed the presence of several ...

  16. Compositional analysis of water-soluble materials in switchgrass.

    Science.gov (United States)

    Chen, Shou-Feng; Mowery, Richard A; Sevcik, Richard S; Scarlata, Christopher J; Chambliss, C Kevin

    2010-03-24

    Any valuation of a potential feedstock for bioprocessing is inherently dependent upon detailed knowledge of its chemical composition. Accepted analytical procedures for compositional analysis of biomass water-soluble extracts currently enable near-quantitative mass closure on a dry weight basis. Techniques developed in conjunction with a previous analytical assessment of corn stover have been applied to assess the composition of water-soluble materials in four representative switchgrass samples. To date, analytical characterization of water-soluble material in switchgrass has resulted in >78% mass closures for all four switchgrass samples, three of which have a mass closure of >85%. Over 30 previously unknown constituents in aqueous extracts of switchgrass were identified and quantified using a variety of chromatographic techniques. Carbohydrates (primarily sucrose, glucose, and fructose) were found to be the predominant water-soluble components of switchgrass, accounting for 18-27% of the dry weight of extractives. Total glycans (monomeric and oligomeric sugars) contributed 25-32% to the dry weight of extractives. Additional constituents contributing to the mass balance for extractives included various alditols (2-3%), organic acids (10-13%), inorganic ions (11-13%), and a distribution of oligomers presumed to represent a diverse mixture of lignin-carbohydrate complexes (30-35%). Switchgrass results are compared with previous analyses of corn stover extracts and presented in the context of their potential impact on biomass processing, feedstock storage, and future analyses of feedstock composition.

  17. Solubility of HCL in sulfuric acid at stratospheric temperatures

    Science.gov (United States)

    Williams, Leah R.; Golden, David M.

    1993-01-01

    The solubility of HCl in sulfuric acid was measured using a Knudsen cell technique. Effective Henry's law constants are reported for sulfuric acid concentrations between 50 and 60 weight percent and for temperatures between 220 and 230 K. The measured values indicate that very little HCl will be dissolved in the stratospheric sulfate aerosol particles.

  18. THE EFFECT OF THE PROTEIN SOLUBILITY OF FISH MEAL AND ...

    African Journals Online (AJOL)

    utilization of fish meal proteins was determined by a relationship between their solubility or apparent digestibility and the rate of passage of digesta through the digestive tract. The treatment of fish meal with formaldehyde decreased its digestibility. The micro-organisms in the rumen may, under certain conditions even have ...

  19. Short Communication Relationships between the water solubility of ...

    African Journals Online (AJOL)

    132. Short Communication. Relationships between the water solubility of roughage dry matter and certain chemical characteristics. J.W. Cilliers- and H.J. Cilliers. North West Agricultural Development lnstitute, Private. Bag X804, Potchefstroom, 2520 Republic of South Africa. Received 17 May 1995; accepted 8 August 1995.

  20. Developing Worksheet Based on Science Process Skills: Factors Affecting Solubility

    Science.gov (United States)

    Karsli, Fethiye; Sahin, Cigdem

    2009-01-01

    The purpose of this study is to develop a worksheet about the factors affecting solubility, which could be useful for the prospective science teachers (PST) to remind and regain their science process skills (SPS). The pilot study of the WS was carried out with 32 first grade PST during the 2007-2008 academic year in the education department at…

  1. Does vivianite control phosphate solubility in anoxic meadow soils?

    DEFF Research Database (Denmark)

    Walpersdorf, Eva Christine; Bender Koch, Christian; Heiberg, Lisa

    2013-01-01

    composition in the gyttja layer was close to equilibrium with vivianite (saturation index, SIviv, 2.01±0.53) at constant pH (~ 6.8). Dissolution and precipitation experiments in the laboratory with soil suspensions from the gyttja layer demonstrated that vivianite solubility equilibria were only slowly...

  2. Enhancement of solubility and dissolution rate of atorvastatin ...

    African Journals Online (AJOL)

    Purpose: To investigate the formation of atorvastatin calcium (AC) co-crystal to improve its solubility and dissolution rate. Method: Co-crystallization of AC in equimolar ratio with isonicotinamide (INA) was carried out by slow solvent evaporation method using methanol. The solid obtained was characterized by powder x-ray ...

  3. Aqueous solubility of ciprofloxacin in the presence of metal cations ...

    African Journals Online (AJOL)

    Purpose: Though the complexation of ciprofloxacin with metal cations has been extensively studied, the effect of this complexation on the aqueous solubility of ciprofloxacin which is an important factor affecting drug distribution has not been well documented. We have thus set out in this study to investigate the aqueous ...

  4. Rapid solubility and mineral storage of CO2 in basalt

    DEFF Research Database (Denmark)

    Gislason, Sigurdur R.; Broecker, W.S.; Gunnlaugsson, E.

    2014-01-01

    rich in divalent metal cations such as basalts and ultra-mafic rocks. We have demonstrated the dissolution of CO2 into water during its injection into basalt leading to its geologic solubility storage in less than five minutes and potential geologic mineral storage within few years after injection [1...

  5. Hansen solubility parameters for a carbon fiber/epoxy composite

    DEFF Research Database (Denmark)

    Launay, Helene; Hansen, Charles M.; Almdal, Kristoffer

    2007-01-01

    In this study, the physical affinity between an epoxy matrix and oxidized, unsized carbon fibers has been evaluated using Hansen solubility (cohesion) parameters (HSP). A strong physical compatibility has been shown, since their respective HSP are close. The use of a glassy carbon substrate...

  6. The estimation of modified non-specific solubility parameter of ...

    African Journals Online (AJOL)

    For apolar liquids, the modified non-specific solubility parameter ' has been correlated with a form of the Lorentz-Lorenz refractive index function and the molar energy of vaporization per unit volume, and two expressions have been developed. Using one form of these expressions, and by introducing the contribution of ...

  7. Near-road enhancement and solubility of fine and coarse ...

    Science.gov (United States)

    Communities near major roadways are disproportionately affected by traffic-related air pollution which can contribute to adverse health outcomes. The specific role of particulate matter (PM) from traffic sources is not fully understood due to complex emissions processes and physical/chemical properties of PM in the near-road environment. To investigate the spatial profile and water solubility of elemental PM species near a major roadway, filter-based measurements of fine (PM2.5) and coarse (PM10-2.5) PM were simultaneously collected at multiple distances (10 m, 100 m, and 300 m) from Interstate I-96 in Detroit, Michigan during September–November 2010. Filters were extracted in water, followed by a hot acid extraction, and analyzed by magnetic sector field high resolution inductively coupled plasma mass spectrometry (HR-ICPMS) to quantify water-soluble and acid-soluble trace elements for each PM size fraction. PM2.5 and PM10-2.5 species measured in the near-road samples included elements associated with traffic activity, local industrial sources, and regional pollution. Metals indicative of brake wear (Ba, Cu) were dramatically enriched near the roadway during downwind conditions (factor of 5 concentration increase), with the largest increase within 100 m of the roadway. Moderate near-roadway increases were observed for crustal elements and other traffic-related PM (Fe, Ca), and the lowest increases observed for regional PM species (S). Water solubility varied

  8. Solubility of carbon dioxide in aqueous piperazine solutions

    NARCIS (Netherlands)

    Derks, P. W. J.; Dijkstra, H. B. S.; Hogendoorn, J. A.; Versteeg, G. F.

    2005-01-01

    In the present work, new experimental data are presented on the solubility of carbon dioxide in aqueous piperazine solutions, for concentrations of 0.2 and 0.6 molar piperazine and temperatures of 25, 40, and 70°C respectively. The present data, and other data available in the literature, were

  9. Page 1 Solubility of Rare Earth Hydroxides in Aqueous Sodium ...

    Indian Academy of Sciences (India)

    Solubility of Rare Earth Hydroxides in Aqueous Sodium Potassium Tartrate 317 undissolved after treatment with Rochelle Salt solution. The quantity measured was the weight of oxide in the filtrate. This was done by igniting the precipitated oxalate and also by titrating its sulphuric acid solution against standard potassium ...

  10. Solubility of manure phosphorus characterized by selective and sequential extractions

    Science.gov (United States)

    The increasing awareness of the severity of the problem of phosphorus (P) derived from agricultural production moving off-farm and threatening water quality has led to the search for methods to characterize the forms and potential solubilities of phosphorus in food animal manures and manure products...

  11. Solubility tests and the peripheral blood film method for screening ...

    African Journals Online (AJOL)

    Objective. To determine the cost benefit of screening for sicklecell disease among infants at district health centres in Uganda using sickling, solubility tests and the peripheral blood film method. Methods. Pilot screening services were established at district health centres. Cost benefit analysis (CBA) was performed in four ...

  12. Robust model of fresh jujube soluble solids content with near ...

    African Journals Online (AJOL)

    A robust partial least square (PLS) calibration model with high accuracy and stability was established for the measurement of soluble solids content (SSC) of fresh jujube using near-infrared (NIR) spectroscopy technique. Fresh jujube samples were collected in different areas of Taigu and Taiyuan cities, central China in ...

  13. Soluble ICAM-1 activates lung macrophages and enhances lung injury

    DEFF Research Database (Denmark)

    Schmal, H; Czermak, B J; Lentsch, A B

    1998-01-01

    Because of the important role of rat ICAM-1 in the development of lung inflammatory injury, soluble recombinant rat ICAM-1 (sICAM-1) was expressed in bacteria, and its biologic activities were evaluated. Purified sICAM-1 did bind to rat alveolar macrophages in a dose-dependent manner and induced...

  14. Spatial distribution of soluble reactive silica (SRSi) in the Tanzanian ...

    African Journals Online (AJOL)

    Spatial distribution of soluble reactive silica (SRSi) in the Tanzanian waters of Lake Victoria and its implications for diatom productivity. ... The change in diatom species composition and abundance, leading to the dominance of robust and opportunistic species, is probably accelerated by the increased eutrophication and ...

  15. Optimization of translation profiles enhances protein expression and solubility.

    Directory of Open Access Journals (Sweden)

    Anne-Katrin Hess

    Full Text Available mRNA is translated with a non-uniform speed that actively coordinates co-translational folding of protein domains. Using structure-based homology we identified the structural domains in epoxide hydrolases (EHs and introduced slow-translating codons to delineate the translation of single domains. These changes in translation speed dramatically improved the solubility of two EHs of metagenomic origin in Escherichia coli. Conversely, the importance of transient attenuation for the folding, and consequently solubility, of EH was evidenced with a member of the EH family from Agrobacterium radiobacter, which partitions in the soluble fraction when expressed in E. coli. Synonymous substitutions of codons shaping the slow-transiting regions to fast-translating codons render this protein insoluble. Furthermore, we show that low protein yield can be enhanced by decreasing the free folding energy of the initial 5'-coding region, which can disrupt mRNA secondary structure and enhance ribosomal loading. This study provides direct experimental evidence that mRNA is not a mere messenger for translation of codons into amino acids but bears an additional layer of information for folding, solubility and expression level of the encoded protein. Furthermore, it provides a general frame on how to modulate and fine-tune gene expression of a target protein.

  16. The use of captisol (SBE7-β-CD) in oral solubility-enabling formulations: Comparison to HPβCD and the solubility-permeability interplay.

    Science.gov (United States)

    Beig, Avital; Agbaria, Riad; Dahan, Arik

    2015-09-18

    The aim of this research was to study the interaction of sulfobutyl ether7 β-cyclodextrin (captisol) and 2-hydroxypropyl-β-cyclodextrin (HPβCD) with the poorly soluble antiarrhythmic drug amiodarone, and to investigate the consequent solubility-permeability interplay. Phase-solubility studies of amiodarone with the two cyclodextrins, followed by PAMPA and rat intestinal permeability experiments, were carried out, and the solubility-permeability interplay was then illustrated as a function of increasing cyclodextrin content. Equimolar levels of captisol allowed ∼10-fold higher amiodarone solubility than HPβCD, as well as binding constant. With both captisol and HPβCD, decreased in vitro and in vivo amiodarone apparent permeability was evident with increasing CD levels and increased apparent solubility. A theoretical model assuming direct proportionality between the apparent solubility increase allowed by the CD and permeability decrease was able to accurately predict the solubility-permeability tradeoff as a function of CD levels. In conclusion, the addition of ionic interactions (e.g. amiodarone-captisol) to hydrophobic interactions of the inclusion complex formation may result in synergic effect on solubilization; however, it is not merely the solubility that should be examined when formulating an oral poorly soluble compound, but the solubility-permeability balance, in order to maximize the overall drug exposure. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Geochemical evidence of water-soluble gas accumulation in the Weiyuan gas field, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Shengfei Qin

    2016-01-01

    Full Text Available At present, there are several different opinions on the formation process of the Weiyuan gas field in the Sichuan Basin and the source of its natural gas. In view of the fact that the methane carbon isotope of the natural gas in the Weiyuan gas field is abnormally heavy, the geologic characteristics of gas reservoirs and the geochemical characteristics of natural gas were first analyzed. In the Weiyuan gas field, the principal gas reservoirs belong to Sinian Dengying Fm. The natural gas is mainly composed of methane, with slight ethane and trace propane. The gas reservoirs are higher in water saturation, with well preserved primary water. Then, it was discriminated from the relationship of H2S content vs. methane carbon isotope that the heavier methane carbon isotope of natural gas in this area is not caused by thermochemical sulfate reduction (TSR. Based on the comparison of methane carbon isotope in this area with that in adjacent areas, and combined with the tectonic evolution background, it is regarded that the natural gas in the Weiyuan gas field is mainly derived from water-soluble gas rather than be migrated laterally from adjacent areas. Some conclusions are made. First, since methane released from water is carbon isotopically heavier, the water-soluble gas accumulation after degasification results in the heavy methane carbon isotope of the gas produced from Weiyuan gas field. Second, along with Himalayan movement, great uplift occurred in the Weiyuan area and structural traps were formed. Under high temperature and high pressure, the gas dissolved in water experienced decompression precipitation, and the released natural gas accumulated in traps, consequently leading to the formation of Weiyuan gas field. Third, based on calculation, the amount of natural gas released from water which is entrapped in the Weiyuan gas field after the tectonic uplift is basically equal to the proved reserves of this field, confirming the opinion of water-soluble

  18. Doping in the Valley of Hydrogen Solubility: A Route to Designing Hydrogen-Resistant Zirconium Alloys

    Science.gov (United States)

    Youssef, Mostafa; Yang, Ming; Yildiz, Bilge

    2016-01-01

    Hydrogen pickup and embrittlement pose a challenging safety limit for structural alloys used in a wide range of infrastructure applications, including zirconium alloys in nuclear reactors. Previous experimental observations guide the empirical design of hydrogen-resistant zirconium alloys, but the underlying mechanisms remain undecipherable. Here, we assess two critical prongs of hydrogen pickup through the ZrO2 passive film that serves as a surface barrier of zirconium alloys; the solubility of hydrogen in it—a detrimental process—and the ease of H2 gas evolution from its surface—a desirable process. By combining statistical thermodynamics and density-functional-theory calculations, we show that hydrogen solubility in ZrO2 exhibits a valley shape as a function of the chemical potential of electrons, μe . Here, μe , which is tunable by doping, serves as a physical descriptor of hydrogen resistance based on the electronic structure of ZrO2 . For designing zirconium alloys resistant against hydrogen pickup, we target either a dopant that thermodynamically minimizes the solubility of hydrogen in ZrO2 at the bottom of this valley (such as Cr) or a dopant that maximizes μe and kinetically accelerates proton reduction and H2 evolution at the surface of ZrO2 (such as Nb, Ta, Mo, W, or P). Maximizing μe also promotes the predomination of a less-mobile form of hydrogen defect, which can reduce the flux of hydrogen uptake. The analysis presented here for the case of ZrO2 passive film on Zr alloys serves as a broadly applicable and physically informed framework to uncover doping strategies to mitigate hydrogen embrittlement also in other alloys, such as austenitic steels or nickel alloys, which absorb hydrogen through their surface oxide films.

  19. Soluble expression of disulfide bond containing proteins FGF15 and FGF19 in the cytoplasm of Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Bo Kong

    Full Text Available Fibroblast growth factor 19 (FGF19 is the human ortholog of mouse FGF15, and both proteins function as an endocrine signal to regulate various liver functions. FGF15/FGF19 protein contains two disulfide bonds. It is unfavorable to form disulfide bonds in Escherichia coli (E. coli cytoplasm because of the bacterial cytoplasmic reducing environment. Modification of the cytoplasmic reducing environment and/or co-expression of protein chaperones are common strategies to express disulfide bond containing proteins in E. coli. In the current study, we report a method to produce soluble FGF15/FGF19 protein in cytoplasm of E. coli. Several commercial available strains with the disruption of thiol-redox pathways, and/or co-expression of redoxase or refolding chaperones were used to develop this novel method for expression of FGF15/FGF19 in E. coli. Mutation of the thiol-disulfide bond reducing pathway in E. coli or N-terminal fusion of thioredox (TRX alone is not enough to support disulfide bond formation in FGF15/19 proteins. However, TRX fusion protein improved FGF19 solubility in strains of thiol-redox system mutants. In addition, DsbC co-expressed in thiol-redox system mutants alone improved and further enhanced FGF19 solubility with combination of TRX fusion tag. The soluble FGF19 proteins were easily purified through Ni-NTA affinity chromatography and anion exchange chromatography, and the purified protein maintained its biological activities, confirmed by suppressing hepatic Cyp7a1 gene transcription in mice and by activating ERK1/2 signaling pathway in HepG2 cells. In contrast, soluble FGF15 protein in cytoplasm remained very low using these strategies. In summary, we have successfully developed a method to express functional FGF19 protein in prokaryotic cells, and this strategy may be adapted for the expression of other disulfide-containing proteins.

  20. Soluplus® as an effective absorption enhancer of poorly soluble drugs in vitro and in vivo.

    Science.gov (United States)

    Linn, Michael; Collnot, Eva-Maria; Djuric, Dejan; Hempel, Katja; Fabian, Eric; Kolter, Karl; Lehr, Claus-Michael

    2012-02-14

    As many new active pharmaceutical ingredients are poorly water soluble, solubility enhancers are one possibility to overcome the hurdles of drug dissolution and absorption in oral drug delivery. In the present work a novel solubility enhancing excipient (Soluplus®) was tested for its capability to improve intestinal drug absorption. BCS class II compounds danazol, fenofibrate and itraconazole were tested both in vivo in beagle dogs and in vitro in transport experiments across Caco-2 cell monolayers. Each drug was applied as pure crystalline substance, in a physical mixture with Soluplus®, and as solid solution of the drug in the excipient. In the animal studies a many fold increase in plasma AUC was observed for the solid solutions of drug in Soluplus® compared to the respective pure drug. An effect of Soluplus® in a physical mixture with the drug could be detected for fenofibrate. In vitro transport studies confirm the strong effect of Soluplus® on the absorption behavior of the three tested drugs. Furthermore, the increase of drug flux across Caco-2 monolayer is correlating to the increase in plasma AUC and C(max)in vivo. For these poorly soluble substances Soluplus® has a strong potential to improve oral bioavailability. The applicability of Caco-2 monolayers as tool for predicting the in vivo transport behavior of the model drugs in combination with a solubility enhancing excipient was shown. Also the improvement of a solid dispersion compared to physical mixtures of the drugs and the excipient was correctly reflected by Caco-2 experiments. In the case of fenofibrate the possible improvement by a physical mixture was demonstrated, underscoring the value of the used tool as alternative to animal studies. Copyright © 2011 Elsevier B.V. All rights reserved.